1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * Generic hugetlb support. 46d49e352SNadia Yvette Chambers * (C) Nadia Yvette Chambers, April 2004 51da177e4SLinus Torvalds */ 61da177e4SLinus Torvalds #include <linux/list.h> 71da177e4SLinus Torvalds #include <linux/init.h> 81da177e4SLinus Torvalds #include <linux/mm.h> 9e1759c21SAlexey Dobriyan #include <linux/seq_file.h> 101da177e4SLinus Torvalds #include <linux/sysctl.h> 111da177e4SLinus Torvalds #include <linux/highmem.h> 12cddb8a5cSAndrea Arcangeli #include <linux/mmu_notifier.h> 131da177e4SLinus Torvalds #include <linux/nodemask.h> 1463551ae0SDavid Gibson #include <linux/pagemap.h> 155da7ca86SChristoph Lameter #include <linux/mempolicy.h> 163b32123dSGideon Israel Dsouza #include <linux/compiler.h> 17aea47ff3SChristoph Lameter #include <linux/cpuset.h> 183935baa9SDavid Gibson #include <linux/mutex.h> 1997ad1087SMike Rapoport #include <linux/memblock.h> 20a3437870SNishanth Aravamudan #include <linux/sysfs.h> 215a0e3ad6STejun Heo #include <linux/slab.h> 22bbe88753SJoonsoo Kim #include <linux/sched/mm.h> 2363489f8eSMike Kravetz #include <linux/mmdebug.h> 24174cd4b1SIngo Molnar #include <linux/sched/signal.h> 250fe6e20bSNaoya Horiguchi #include <linux/rmap.h> 26c6247f72SMatthew Wilcox #include <linux/string_helpers.h> 27fd6a03edSNaoya Horiguchi #include <linux/swap.h> 28fd6a03edSNaoya Horiguchi #include <linux/swapops.h> 298382d914SDavidlohr Bueso #include <linux/jhash.h> 3098fa15f3SAnshuman Khandual #include <linux/numa.h> 31c77c0a8aSWaiman Long #include <linux/llist.h> 32cf11e85fSRoman Gushchin #include <linux/cma.h> 338cc5fcbbSMina Almasry #include <linux/migrate.h> 34f9317f77SMike Kravetz #include <linux/nospec.h> 35662ce1dcSYang Yang #include <linux/delayacct.h> 36b958d4d0SMuchun Song #include <linux/memory.h> 37d6606683SLinus Torvalds 3863551ae0SDavid Gibson #include <asm/page.h> 39ca15ca40SMike Rapoport #include <asm/pgalloc.h> 4024669e58SAneesh Kumar K.V #include <asm/tlb.h> 4163551ae0SDavid Gibson 4224669e58SAneesh Kumar K.V #include <linux/io.h> 4363551ae0SDavid Gibson #include <linux/hugetlb.h> 449dd540e2SAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 459a305230SLee Schermerhorn #include <linux/node.h> 46ab5ac90aSMichal Hocko #include <linux/page_owner.h> 477835e98bSNick Piggin #include "internal.h" 48f41f2ed4SMuchun Song #include "hugetlb_vmemmap.h" 491da177e4SLinus Torvalds 50c3f38a38SAneesh Kumar K.V int hugetlb_max_hstate __read_mostly; 51e5ff2159SAndi Kleen unsigned int default_hstate_idx; 52e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 53cf11e85fSRoman Gushchin 54dbda8feaSBarry Song #ifdef CONFIG_CMA 55cf11e85fSRoman Gushchin static struct cma *hugetlb_cma[MAX_NUMNODES]; 5638e719abSBaolin Wang static unsigned long hugetlb_cma_size_in_node[MAX_NUMNODES] __initdata; 572f6c57d6SSidhartha Kumar static bool hugetlb_cma_folio(struct folio *folio, unsigned int order) 58a01f4390SMike Kravetz { 592f6c57d6SSidhartha Kumar return cma_pages_valid(hugetlb_cma[folio_nid(folio)], &folio->page, 60a01f4390SMike Kravetz 1 << order); 61a01f4390SMike Kravetz } 62a01f4390SMike Kravetz #else 632f6c57d6SSidhartha Kumar static bool hugetlb_cma_folio(struct folio *folio, unsigned int order) 64a01f4390SMike Kravetz { 65a01f4390SMike Kravetz return false; 66a01f4390SMike Kravetz } 67dbda8feaSBarry Song #endif 68dbda8feaSBarry Song static unsigned long hugetlb_cma_size __initdata; 69cf11e85fSRoman Gushchin 7053ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 7153ba51d2SJon Tollefson 72e5ff2159SAndi Kleen /* for command line parsing */ 73e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 74e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 759fee021dSVaishali Thakkar static bool __initdata parsed_valid_hugepagesz = true; 76282f4214SMike Kravetz static bool __initdata parsed_default_hugepagesz; 77b5389086SZhenguo Yao static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata; 78e5ff2159SAndi Kleen 793935baa9SDavid Gibson /* 8031caf665SNaoya Horiguchi * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, 8131caf665SNaoya Horiguchi * free_huge_pages, and surplus_huge_pages. 823935baa9SDavid Gibson */ 83c3f38a38SAneesh Kumar K.V DEFINE_SPINLOCK(hugetlb_lock); 840bd0f9fbSEric Paris 858382d914SDavidlohr Bueso /* 868382d914SDavidlohr Bueso * Serializes faults on the same logical page. This is used to 878382d914SDavidlohr Bueso * prevent spurious OOMs when the hugepage pool is fully utilized. 888382d914SDavidlohr Bueso */ 898382d914SDavidlohr Bueso static int num_fault_mutexes; 90c672c7f2SMike Kravetz struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; 918382d914SDavidlohr Bueso 927ca02d0aSMike Kravetz /* Forward declaration */ 937ca02d0aSMike Kravetz static int hugetlb_acct_memory(struct hstate *h, long delta); 948d9bfb26SMike Kravetz static void hugetlb_vma_lock_free(struct vm_area_struct *vma); 958d9bfb26SMike Kravetz static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma); 96ecfbd733SMike Kravetz static void __hugetlb_vma_unlock_write_free(struct vm_area_struct *vma); 97b30c14cdSJames Houghton static void hugetlb_unshare_pmds(struct vm_area_struct *vma, 98b30c14cdSJames Houghton unsigned long start, unsigned long end); 997ca02d0aSMike Kravetz 1001d88433bSMiaohe Lin static inline bool subpool_is_free(struct hugepage_subpool *spool) 1011d88433bSMiaohe Lin { 1021d88433bSMiaohe Lin if (spool->count) 1031d88433bSMiaohe Lin return false; 1041d88433bSMiaohe Lin if (spool->max_hpages != -1) 1051d88433bSMiaohe Lin return spool->used_hpages == 0; 1061d88433bSMiaohe Lin if (spool->min_hpages != -1) 1071d88433bSMiaohe Lin return spool->rsv_hpages == spool->min_hpages; 1081d88433bSMiaohe Lin 1091d88433bSMiaohe Lin return true; 1101d88433bSMiaohe Lin } 1111d88433bSMiaohe Lin 112db71ef79SMike Kravetz static inline void unlock_or_release_subpool(struct hugepage_subpool *spool, 113db71ef79SMike Kravetz unsigned long irq_flags) 11490481622SDavid Gibson { 115db71ef79SMike Kravetz spin_unlock_irqrestore(&spool->lock, irq_flags); 11690481622SDavid Gibson 11790481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 1187c8de358SEthon Paul * remain, give up any reservations based on minimum size and 1197ca02d0aSMike Kravetz * free the subpool */ 1201d88433bSMiaohe Lin if (subpool_is_free(spool)) { 1217ca02d0aSMike Kravetz if (spool->min_hpages != -1) 1227ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 1237ca02d0aSMike Kravetz -spool->min_hpages); 12490481622SDavid Gibson kfree(spool); 12590481622SDavid Gibson } 1267ca02d0aSMike Kravetz } 12790481622SDavid Gibson 1287ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1297ca02d0aSMike Kravetz long min_hpages) 13090481622SDavid Gibson { 13190481622SDavid Gibson struct hugepage_subpool *spool; 13290481622SDavid Gibson 133c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 13490481622SDavid Gibson if (!spool) 13590481622SDavid Gibson return NULL; 13690481622SDavid Gibson 13790481622SDavid Gibson spin_lock_init(&spool->lock); 13890481622SDavid Gibson spool->count = 1; 1397ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1407ca02d0aSMike Kravetz spool->hstate = h; 1417ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1427ca02d0aSMike Kravetz 1437ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1447ca02d0aSMike Kravetz kfree(spool); 1457ca02d0aSMike Kravetz return NULL; 1467ca02d0aSMike Kravetz } 1477ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 14890481622SDavid Gibson 14990481622SDavid Gibson return spool; 15090481622SDavid Gibson } 15190481622SDavid Gibson 15290481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 15390481622SDavid Gibson { 154db71ef79SMike Kravetz unsigned long flags; 155db71ef79SMike Kravetz 156db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 15790481622SDavid Gibson BUG_ON(!spool->count); 15890481622SDavid Gibson spool->count--; 159db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 16090481622SDavid Gibson } 16190481622SDavid Gibson 1621c5ecae3SMike Kravetz /* 1631c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1641c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1659e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1661c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1671c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1687c8de358SEthon Paul * a subpool minimum size must be maintained. 1691c5ecae3SMike Kravetz */ 1701c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 17190481622SDavid Gibson long delta) 17290481622SDavid Gibson { 1731c5ecae3SMike Kravetz long ret = delta; 17490481622SDavid Gibson 17590481622SDavid Gibson if (!spool) 1761c5ecae3SMike Kravetz return ret; 17790481622SDavid Gibson 178db71ef79SMike Kravetz spin_lock_irq(&spool->lock); 17990481622SDavid Gibson 1801c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1811c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1821c5ecae3SMike Kravetz spool->used_hpages += delta; 1831c5ecae3SMike Kravetz else { 1841c5ecae3SMike Kravetz ret = -ENOMEM; 1851c5ecae3SMike Kravetz goto unlock_ret; 1861c5ecae3SMike Kravetz } 1871c5ecae3SMike Kravetz } 1881c5ecae3SMike Kravetz 18909a95e29SMike Kravetz /* minimum size accounting */ 19009a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1911c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1921c5ecae3SMike Kravetz /* 1931c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1941c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1951c5ecae3SMike Kravetz */ 1961c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1971c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1981c5ecae3SMike Kravetz } else { 1991c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 2001c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 2011c5ecae3SMike Kravetz } 2021c5ecae3SMike Kravetz } 2031c5ecae3SMike Kravetz 2041c5ecae3SMike Kravetz unlock_ret: 205db71ef79SMike Kravetz spin_unlock_irq(&spool->lock); 20690481622SDavid Gibson return ret; 20790481622SDavid Gibson } 20890481622SDavid Gibson 2091c5ecae3SMike Kravetz /* 2101c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 2111c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 2121c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 2131c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 2141c5ecae3SMike Kravetz */ 2151c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 21690481622SDavid Gibson long delta) 21790481622SDavid Gibson { 2181c5ecae3SMike Kravetz long ret = delta; 219db71ef79SMike Kravetz unsigned long flags; 2201c5ecae3SMike Kravetz 22190481622SDavid Gibson if (!spool) 2221c5ecae3SMike Kravetz return delta; 22390481622SDavid Gibson 224db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 2251c5ecae3SMike Kravetz 2261c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 22790481622SDavid Gibson spool->used_hpages -= delta; 2281c5ecae3SMike Kravetz 22909a95e29SMike Kravetz /* minimum size accounting */ 23009a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2311c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2321c5ecae3SMike Kravetz ret = 0; 2331c5ecae3SMike Kravetz else 2341c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2351c5ecae3SMike Kravetz 2361c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2371c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2381c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2391c5ecae3SMike Kravetz } 2401c5ecae3SMike Kravetz 2411c5ecae3SMike Kravetz /* 2421c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2431c5ecae3SMike Kravetz * quota reference, free it now. 2441c5ecae3SMike Kravetz */ 245db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 2461c5ecae3SMike Kravetz 2471c5ecae3SMike Kravetz return ret; 24890481622SDavid Gibson } 24990481622SDavid Gibson 25090481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 25190481622SDavid Gibson { 25290481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 25390481622SDavid Gibson } 25490481622SDavid Gibson 25590481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 25690481622SDavid Gibson { 257496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 25890481622SDavid Gibson } 25990481622SDavid Gibson 260e700898fSMike Kravetz /* 261e700898fSMike Kravetz * hugetlb vma_lock helper routines 262e700898fSMike Kravetz */ 263e700898fSMike Kravetz static bool __vma_shareable_lock(struct vm_area_struct *vma) 264e700898fSMike Kravetz { 265e700898fSMike Kravetz return vma->vm_flags & (VM_MAYSHARE | VM_SHARED) && 266e700898fSMike Kravetz vma->vm_private_data; 267e700898fSMike Kravetz } 268e700898fSMike Kravetz 269e700898fSMike Kravetz void hugetlb_vma_lock_read(struct vm_area_struct *vma) 270e700898fSMike Kravetz { 271e700898fSMike Kravetz if (__vma_shareable_lock(vma)) { 272e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 273e700898fSMike Kravetz 274e700898fSMike Kravetz down_read(&vma_lock->rw_sema); 275e700898fSMike Kravetz } 276e700898fSMike Kravetz } 277e700898fSMike Kravetz 278e700898fSMike Kravetz void hugetlb_vma_unlock_read(struct vm_area_struct *vma) 279e700898fSMike Kravetz { 280e700898fSMike Kravetz if (__vma_shareable_lock(vma)) { 281e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 282e700898fSMike Kravetz 283e700898fSMike Kravetz up_read(&vma_lock->rw_sema); 284e700898fSMike Kravetz } 285e700898fSMike Kravetz } 286e700898fSMike Kravetz 287e700898fSMike Kravetz void hugetlb_vma_lock_write(struct vm_area_struct *vma) 288e700898fSMike Kravetz { 289e700898fSMike Kravetz if (__vma_shareable_lock(vma)) { 290e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 291e700898fSMike Kravetz 292e700898fSMike Kravetz down_write(&vma_lock->rw_sema); 293e700898fSMike Kravetz } 294e700898fSMike Kravetz } 295e700898fSMike Kravetz 296e700898fSMike Kravetz void hugetlb_vma_unlock_write(struct vm_area_struct *vma) 297e700898fSMike Kravetz { 298e700898fSMike Kravetz if (__vma_shareable_lock(vma)) { 299e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 300e700898fSMike Kravetz 301e700898fSMike Kravetz up_write(&vma_lock->rw_sema); 302e700898fSMike Kravetz } 303e700898fSMike Kravetz } 304e700898fSMike Kravetz 305e700898fSMike Kravetz int hugetlb_vma_trylock_write(struct vm_area_struct *vma) 306e700898fSMike Kravetz { 307e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 308e700898fSMike Kravetz 309e700898fSMike Kravetz if (!__vma_shareable_lock(vma)) 310e700898fSMike Kravetz return 1; 311e700898fSMike Kravetz 312e700898fSMike Kravetz return down_write_trylock(&vma_lock->rw_sema); 313e700898fSMike Kravetz } 314e700898fSMike Kravetz 315e700898fSMike Kravetz void hugetlb_vma_assert_locked(struct vm_area_struct *vma) 316e700898fSMike Kravetz { 317e700898fSMike Kravetz if (__vma_shareable_lock(vma)) { 318e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 319e700898fSMike Kravetz 320e700898fSMike Kravetz lockdep_assert_held(&vma_lock->rw_sema); 321e700898fSMike Kravetz } 322e700898fSMike Kravetz } 323e700898fSMike Kravetz 324e700898fSMike Kravetz void hugetlb_vma_lock_release(struct kref *kref) 325e700898fSMike Kravetz { 326e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock = container_of(kref, 327e700898fSMike Kravetz struct hugetlb_vma_lock, refs); 328e700898fSMike Kravetz 329e700898fSMike Kravetz kfree(vma_lock); 330e700898fSMike Kravetz } 331e700898fSMike Kravetz 332e700898fSMike Kravetz static void __hugetlb_vma_unlock_write_put(struct hugetlb_vma_lock *vma_lock) 333e700898fSMike Kravetz { 334e700898fSMike Kravetz struct vm_area_struct *vma = vma_lock->vma; 335e700898fSMike Kravetz 336e700898fSMike Kravetz /* 337e700898fSMike Kravetz * vma_lock structure may or not be released as a result of put, 338e700898fSMike Kravetz * it certainly will no longer be attached to vma so clear pointer. 339e700898fSMike Kravetz * Semaphore synchronizes access to vma_lock->vma field. 340e700898fSMike Kravetz */ 341e700898fSMike Kravetz vma_lock->vma = NULL; 342e700898fSMike Kravetz vma->vm_private_data = NULL; 343e700898fSMike Kravetz up_write(&vma_lock->rw_sema); 344e700898fSMike Kravetz kref_put(&vma_lock->refs, hugetlb_vma_lock_release); 345e700898fSMike Kravetz } 346e700898fSMike Kravetz 347e700898fSMike Kravetz static void __hugetlb_vma_unlock_write_free(struct vm_area_struct *vma) 348e700898fSMike Kravetz { 349e700898fSMike Kravetz if (__vma_shareable_lock(vma)) { 350e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 351e700898fSMike Kravetz 352e700898fSMike Kravetz __hugetlb_vma_unlock_write_put(vma_lock); 353e700898fSMike Kravetz } 354e700898fSMike Kravetz } 355e700898fSMike Kravetz 356e700898fSMike Kravetz static void hugetlb_vma_lock_free(struct vm_area_struct *vma) 357e700898fSMike Kravetz { 358e700898fSMike Kravetz /* 359e700898fSMike Kravetz * Only present in sharable vmas. 360e700898fSMike Kravetz */ 361e700898fSMike Kravetz if (!vma || !__vma_shareable_lock(vma)) 362e700898fSMike Kravetz return; 363e700898fSMike Kravetz 364e700898fSMike Kravetz if (vma->vm_private_data) { 365e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 366e700898fSMike Kravetz 367e700898fSMike Kravetz down_write(&vma_lock->rw_sema); 368e700898fSMike Kravetz __hugetlb_vma_unlock_write_put(vma_lock); 369e700898fSMike Kravetz } 370e700898fSMike Kravetz } 371e700898fSMike Kravetz 372e700898fSMike Kravetz static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma) 373e700898fSMike Kravetz { 374e700898fSMike Kravetz struct hugetlb_vma_lock *vma_lock; 375e700898fSMike Kravetz 376e700898fSMike Kravetz /* Only establish in (flags) sharable vmas */ 377e700898fSMike Kravetz if (!vma || !(vma->vm_flags & VM_MAYSHARE)) 378e700898fSMike Kravetz return; 379e700898fSMike Kravetz 380e700898fSMike Kravetz /* Should never get here with non-NULL vm_private_data */ 381e700898fSMike Kravetz if (vma->vm_private_data) 382e700898fSMike Kravetz return; 383e700898fSMike Kravetz 384e700898fSMike Kravetz vma_lock = kmalloc(sizeof(*vma_lock), GFP_KERNEL); 385e700898fSMike Kravetz if (!vma_lock) { 386e700898fSMike Kravetz /* 387e700898fSMike Kravetz * If we can not allocate structure, then vma can not 388e700898fSMike Kravetz * participate in pmd sharing. This is only a possible 389e700898fSMike Kravetz * performance enhancement and memory saving issue. 390e700898fSMike Kravetz * However, the lock is also used to synchronize page 391e700898fSMike Kravetz * faults with truncation. If the lock is not present, 392e700898fSMike Kravetz * unlikely races could leave pages in a file past i_size 393e700898fSMike Kravetz * until the file is removed. Warn in the unlikely case of 394e700898fSMike Kravetz * allocation failure. 395e700898fSMike Kravetz */ 396e700898fSMike Kravetz pr_warn_once("HugeTLB: unable to allocate vma specific lock\n"); 397e700898fSMike Kravetz return; 398e700898fSMike Kravetz } 399e700898fSMike Kravetz 400e700898fSMike Kravetz kref_init(&vma_lock->refs); 401e700898fSMike Kravetz init_rwsem(&vma_lock->rw_sema); 402e700898fSMike Kravetz vma_lock->vma = vma; 403e700898fSMike Kravetz vma->vm_private_data = vma_lock; 404e700898fSMike Kravetz } 405e700898fSMike Kravetz 4060db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 4070db9d74eSMina Almasry * it for use. 4080db9d74eSMina Almasry */ 4090db9d74eSMina Almasry static struct file_region * 4100db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 4110db9d74eSMina Almasry { 4123259914fSXU pengfei struct file_region *nrg; 4130db9d74eSMina Almasry 4140db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 4150db9d74eSMina Almasry 4160db9d74eSMina Almasry resv->region_cache_count--; 4170db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 4180db9d74eSMina Almasry list_del(&nrg->link); 4190db9d74eSMina Almasry 4200db9d74eSMina Almasry nrg->from = from; 4210db9d74eSMina Almasry nrg->to = to; 4220db9d74eSMina Almasry 4230db9d74eSMina Almasry return nrg; 4240db9d74eSMina Almasry } 4250db9d74eSMina Almasry 426075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 427075a61d0SMina Almasry struct file_region *rg) 428075a61d0SMina Almasry { 429075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 430075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 431075a61d0SMina Almasry nrg->css = rg->css; 432075a61d0SMina Almasry if (rg->css) 433075a61d0SMina Almasry css_get(rg->css); 434075a61d0SMina Almasry #endif 435075a61d0SMina Almasry } 436075a61d0SMina Almasry 437075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 438075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 439075a61d0SMina Almasry struct hstate *h, 440075a61d0SMina Almasry struct resv_map *resv, 441075a61d0SMina Almasry struct file_region *nrg) 442075a61d0SMina Almasry { 443075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 444075a61d0SMina Almasry if (h_cg) { 445075a61d0SMina Almasry nrg->reservation_counter = 446075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 447075a61d0SMina Almasry nrg->css = &h_cg->css; 448d85aecf2SMiaohe Lin /* 449d85aecf2SMiaohe Lin * The caller will hold exactly one h_cg->css reference for the 450d85aecf2SMiaohe Lin * whole contiguous reservation region. But this area might be 451d85aecf2SMiaohe Lin * scattered when there are already some file_regions reside in 452d85aecf2SMiaohe Lin * it. As a result, many file_regions may share only one css 453d85aecf2SMiaohe Lin * reference. In order to ensure that one file_region must hold 454d85aecf2SMiaohe Lin * exactly one h_cg->css reference, we should do css_get for 455d85aecf2SMiaohe Lin * each file_region and leave the reference held by caller 456d85aecf2SMiaohe Lin * untouched. 457d85aecf2SMiaohe Lin */ 458d85aecf2SMiaohe Lin css_get(&h_cg->css); 459075a61d0SMina Almasry if (!resv->pages_per_hpage) 460075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 461075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 462075a61d0SMina Almasry * a resv_map. 463075a61d0SMina Almasry */ 464075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 465075a61d0SMina Almasry } else { 466075a61d0SMina Almasry nrg->reservation_counter = NULL; 467075a61d0SMina Almasry nrg->css = NULL; 468075a61d0SMina Almasry } 469075a61d0SMina Almasry #endif 470075a61d0SMina Almasry } 471075a61d0SMina Almasry 472d85aecf2SMiaohe Lin static void put_uncharge_info(struct file_region *rg) 473d85aecf2SMiaohe Lin { 474d85aecf2SMiaohe Lin #ifdef CONFIG_CGROUP_HUGETLB 475d85aecf2SMiaohe Lin if (rg->css) 476d85aecf2SMiaohe Lin css_put(rg->css); 477d85aecf2SMiaohe Lin #endif 478d85aecf2SMiaohe Lin } 479d85aecf2SMiaohe Lin 480a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 481a9b3f867SMina Almasry struct file_region *org) 482a9b3f867SMina Almasry { 483a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 4840739eb43SBaolin Wang return rg->reservation_counter == org->reservation_counter && 485a9b3f867SMina Almasry rg->css == org->css; 486a9b3f867SMina Almasry 487a9b3f867SMina Almasry #else 488a9b3f867SMina Almasry return true; 489a9b3f867SMina Almasry #endif 490a9b3f867SMina Almasry } 491a9b3f867SMina Almasry 492a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 493a9b3f867SMina Almasry { 4943259914fSXU pengfei struct file_region *nrg, *prg; 495a9b3f867SMina Almasry 496a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 497a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 498a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 499a9b3f867SMina Almasry prg->to = rg->to; 500a9b3f867SMina Almasry 501a9b3f867SMina Almasry list_del(&rg->link); 502d85aecf2SMiaohe Lin put_uncharge_info(rg); 503a9b3f867SMina Almasry kfree(rg); 504a9b3f867SMina Almasry 5057db5e7b6SWei Yang rg = prg; 506a9b3f867SMina Almasry } 507a9b3f867SMina Almasry 508a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 509a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 510a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 511a9b3f867SMina Almasry nrg->from = rg->from; 512a9b3f867SMina Almasry 513a9b3f867SMina Almasry list_del(&rg->link); 514d85aecf2SMiaohe Lin put_uncharge_info(rg); 515a9b3f867SMina Almasry kfree(rg); 516a9b3f867SMina Almasry } 517a9b3f867SMina Almasry } 518a9b3f867SMina Almasry 5192103cf9cSPeter Xu static inline long 52084448c8eSJakob Koschel hugetlb_resv_map_add(struct resv_map *map, struct list_head *rg, long from, 5212103cf9cSPeter Xu long to, struct hstate *h, struct hugetlb_cgroup *cg, 5222103cf9cSPeter Xu long *regions_needed) 5232103cf9cSPeter Xu { 5242103cf9cSPeter Xu struct file_region *nrg; 5252103cf9cSPeter Xu 5262103cf9cSPeter Xu if (!regions_needed) { 5272103cf9cSPeter Xu nrg = get_file_region_entry_from_cache(map, from, to); 5282103cf9cSPeter Xu record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); 52984448c8eSJakob Koschel list_add(&nrg->link, rg); 5302103cf9cSPeter Xu coalesce_file_region(map, nrg); 5312103cf9cSPeter Xu } else 5322103cf9cSPeter Xu *regions_needed += 1; 5332103cf9cSPeter Xu 5342103cf9cSPeter Xu return to - from; 5352103cf9cSPeter Xu } 5362103cf9cSPeter Xu 537972a3da3SWei Yang /* 538972a3da3SWei Yang * Must be called with resv->lock held. 539972a3da3SWei Yang * 540972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 541972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 542972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 543972a3da3SWei Yang * the regions for this range. 544d75c6af9SMina Almasry */ 545d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 546075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 547972a3da3SWei Yang struct hstate *h, long *regions_needed) 548d75c6af9SMina Almasry { 5490db9d74eSMina Almasry long add = 0; 550d75c6af9SMina Almasry struct list_head *head = &resv->regions; 5510db9d74eSMina Almasry long last_accounted_offset = f; 55284448c8eSJakob Koschel struct file_region *iter, *trg = NULL; 55384448c8eSJakob Koschel struct list_head *rg = NULL; 554d75c6af9SMina Almasry 5550db9d74eSMina Almasry if (regions_needed) 5560db9d74eSMina Almasry *regions_needed = 0; 557d75c6af9SMina Almasry 5580db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 55984448c8eSJakob Koschel * [last_accounted_offset, iter->from), at every iteration, with some 5600db9d74eSMina Almasry * bounds checking. 5610db9d74eSMina Almasry */ 56284448c8eSJakob Koschel list_for_each_entry_safe(iter, trg, head, link) { 5630db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 56484448c8eSJakob Koschel if (iter->from < f) { 5650db9d74eSMina Almasry /* If this region ends after the last accounted offset, 5660db9d74eSMina Almasry * then we need to update last_accounted_offset. 5670db9d74eSMina Almasry */ 56884448c8eSJakob Koschel if (iter->to > last_accounted_offset) 56984448c8eSJakob Koschel last_accounted_offset = iter->to; 5700db9d74eSMina Almasry continue; 5710db9d74eSMina Almasry } 572d75c6af9SMina Almasry 5730db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 5740db9d74eSMina Almasry * finished. 5750db9d74eSMina Almasry */ 57684448c8eSJakob Koschel if (iter->from >= t) { 57784448c8eSJakob Koschel rg = iter->link.prev; 578d75c6af9SMina Almasry break; 57984448c8eSJakob Koschel } 580d75c6af9SMina Almasry 58184448c8eSJakob Koschel /* Add an entry for last_accounted_offset -> iter->from, and 5820db9d74eSMina Almasry * update last_accounted_offset. 583d75c6af9SMina Almasry */ 58484448c8eSJakob Koschel if (iter->from > last_accounted_offset) 58584448c8eSJakob Koschel add += hugetlb_resv_map_add(resv, iter->link.prev, 5862103cf9cSPeter Xu last_accounted_offset, 58784448c8eSJakob Koschel iter->from, h, h_cg, 5882103cf9cSPeter Xu regions_needed); 589d75c6af9SMina Almasry 59084448c8eSJakob Koschel last_accounted_offset = iter->to; 5910db9d74eSMina Almasry } 5920db9d74eSMina Almasry 5930db9d74eSMina Almasry /* Handle the case where our range extends beyond 5940db9d74eSMina Almasry * last_accounted_offset. 5950db9d74eSMina Almasry */ 59684448c8eSJakob Koschel if (!rg) 59784448c8eSJakob Koschel rg = head->prev; 5982103cf9cSPeter Xu if (last_accounted_offset < t) 5992103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, 6002103cf9cSPeter Xu t, h, h_cg, regions_needed); 6010db9d74eSMina Almasry 6020db9d74eSMina Almasry return add; 6030db9d74eSMina Almasry } 6040db9d74eSMina Almasry 6050db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 6060db9d74eSMina Almasry */ 6070db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 6080db9d74eSMina Almasry int regions_needed) 6090db9d74eSMina Almasry __must_hold(&resv->lock) 6100db9d74eSMina Almasry { 61134665341SMiaohe Lin LIST_HEAD(allocated_regions); 6120db9d74eSMina Almasry int to_allocate = 0, i = 0; 6130db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 6140db9d74eSMina Almasry 6150db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 6160db9d74eSMina Almasry 6170db9d74eSMina Almasry /* 6180db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 6190db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 6200db9d74eSMina Almasry * 6210db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 6220db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 6230db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 6240db9d74eSMina Almasry * (adds_in_progress + regions_needed). 6250db9d74eSMina Almasry */ 6260db9d74eSMina Almasry while (resv->region_cache_count < 6270db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 6280db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 6290db9d74eSMina Almasry resv->region_cache_count; 6300db9d74eSMina Almasry 6310db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 632f0953a1bSIngo Molnar * for all the existing adds_in_progress. We should only be 6330db9d74eSMina Almasry * needing to allocate for regions_needed. 6340db9d74eSMina Almasry */ 6350db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 6360db9d74eSMina Almasry 6370db9d74eSMina Almasry spin_unlock(&resv->lock); 6380db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 6390db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 6400db9d74eSMina Almasry if (!trg) 6410db9d74eSMina Almasry goto out_of_memory; 6420db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 6430db9d74eSMina Almasry } 6440db9d74eSMina Almasry 6450db9d74eSMina Almasry spin_lock(&resv->lock); 6460db9d74eSMina Almasry 647d3ec7b6eSWei Yang list_splice(&allocated_regions, &resv->region_cache); 648d3ec7b6eSWei Yang resv->region_cache_count += to_allocate; 6490db9d74eSMina Almasry } 6500db9d74eSMina Almasry 6510db9d74eSMina Almasry return 0; 6520db9d74eSMina Almasry 6530db9d74eSMina Almasry out_of_memory: 6540db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 655d75c6af9SMina Almasry list_del(&rg->link); 656d75c6af9SMina Almasry kfree(rg); 657d75c6af9SMina Almasry } 6580db9d74eSMina Almasry return -ENOMEM; 659d75c6af9SMina Almasry } 660d75c6af9SMina Almasry 6611dd308a7SMike Kravetz /* 6621dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 6630db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 6640db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 6650db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 6660db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 6670db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 668cf3ad20bSMike Kravetz * 6690db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 6700db9d74eSMina Almasry * 6710db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 6720db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 6737c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 6740db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 6750db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 6760db9d74eSMina Almasry * 1 page will only require at most 1 entry. 6771dd308a7SMike Kravetz */ 6780db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 679075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 680075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 68196822904SAndy Whitcroft { 6820db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 68396822904SAndy Whitcroft 6847b24d861SDavidlohr Bueso spin_lock(&resv->lock); 6850db9d74eSMina Almasry retry: 6860db9d74eSMina Almasry 6870db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 688972a3da3SWei Yang add_reservation_in_range(resv, f, t, NULL, NULL, 689972a3da3SWei Yang &actual_regions_needed); 69096822904SAndy Whitcroft 6915e911373SMike Kravetz /* 6920db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 6930db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 6940db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 6950db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 6960db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 6970db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 6980db9d74eSMina Almasry * operation. 6995e911373SMike Kravetz */ 7000db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 7010db9d74eSMina Almasry resv->region_cache_count < 7020db9d74eSMina Almasry resv->adds_in_progress + 7030db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 7040db9d74eSMina Almasry /* region_add operation of range 1 should never need to 7050db9d74eSMina Almasry * allocate file_region entries. 7060db9d74eSMina Almasry */ 7070db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 7085e911373SMike Kravetz 7090db9d74eSMina Almasry if (allocate_file_region_entries( 7100db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 7110db9d74eSMina Almasry return -ENOMEM; 7125e911373SMike Kravetz } 7135e911373SMike Kravetz 7140db9d74eSMina Almasry goto retry; 7150db9d74eSMina Almasry } 716cf3ad20bSMike Kravetz 717972a3da3SWei Yang add = add_reservation_in_range(resv, f, t, h_cg, h, NULL); 7180db9d74eSMina Almasry 7190db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 7200db9d74eSMina Almasry 7217b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 722cf3ad20bSMike Kravetz return add; 72396822904SAndy Whitcroft } 72496822904SAndy Whitcroft 7251dd308a7SMike Kravetz /* 7261dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 7271dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 7281dd308a7SMike Kravetz * represented. This routine is called before a subsequent 7291dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 7301dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 7311dd308a7SMike Kravetz * not change the number of huge pages represented by the 7320db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 7330db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 7340db9d74eSMina Almasry * file_region structure is added. 7350db9d74eSMina Almasry * 7360db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 7370db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 7380db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 7395e911373SMike Kravetz * 7405e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 7415e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 7425e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 7435e911373SMike Kravetz * is needed and can not be allocated. 7441dd308a7SMike Kravetz */ 7450db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 7460db9d74eSMina Almasry long *out_regions_needed) 74796822904SAndy Whitcroft { 74896822904SAndy Whitcroft long chg = 0; 74996822904SAndy Whitcroft 7507b24d861SDavidlohr Bueso spin_lock(&resv->lock); 7515e911373SMike Kravetz 752972a3da3SWei Yang /* Count how many hugepages in this range are NOT represented. */ 753075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 754972a3da3SWei Yang out_regions_needed); 7555e911373SMike Kravetz 7560db9d74eSMina Almasry if (*out_regions_needed == 0) 7570db9d74eSMina Almasry *out_regions_needed = 1; 7585e911373SMike Kravetz 7590db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 7605e911373SMike Kravetz return -ENOMEM; 7615e911373SMike Kravetz 7620db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 76396822904SAndy Whitcroft 7647b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 76596822904SAndy Whitcroft return chg; 76696822904SAndy Whitcroft } 76796822904SAndy Whitcroft 7681dd308a7SMike Kravetz /* 7695e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 7705e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 7715e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 7725e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 7730db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 7740db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 7750db9d74eSMina Almasry * the adds_in_progress counter. 7765e911373SMike Kravetz * 7775e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 7785e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 7795e911373SMike Kravetz * arguments will match the associated region_chg call. 7805e911373SMike Kravetz */ 7810db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 7820db9d74eSMina Almasry long regions_needed) 7835e911373SMike Kravetz { 7845e911373SMike Kravetz spin_lock(&resv->lock); 7855e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 7860db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 7875e911373SMike Kravetz spin_unlock(&resv->lock); 7885e911373SMike Kravetz } 7895e911373SMike Kravetz 7905e911373SMike Kravetz /* 791feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 792feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 793feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 794feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 795feba16e2SMike Kravetz * 796feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 797feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 798feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 799feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 800feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 801feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 802feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 8031dd308a7SMike Kravetz */ 804feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 80596822904SAndy Whitcroft { 8061406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 80796822904SAndy Whitcroft struct file_region *rg, *trg; 808feba16e2SMike Kravetz struct file_region *nrg = NULL; 809feba16e2SMike Kravetz long del = 0; 81096822904SAndy Whitcroft 811feba16e2SMike Kravetz retry: 8127b24d861SDavidlohr Bueso spin_lock(&resv->lock); 813feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 814dbe409e4SMike Kravetz /* 815dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 816dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 817dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 818dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 819dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 820dbe409e4SMike Kravetz */ 821dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 822feba16e2SMike Kravetz continue; 823dbe409e4SMike Kravetz 824feba16e2SMike Kravetz if (rg->from >= t) 82596822904SAndy Whitcroft break; 82696822904SAndy Whitcroft 827feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 828feba16e2SMike Kravetz /* 829feba16e2SMike Kravetz * Check for an entry in the cache before dropping 830feba16e2SMike Kravetz * lock and attempting allocation. 831feba16e2SMike Kravetz */ 832feba16e2SMike Kravetz if (!nrg && 833feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 834feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 835feba16e2SMike Kravetz struct file_region, 836feba16e2SMike Kravetz link); 837feba16e2SMike Kravetz list_del(&nrg->link); 838feba16e2SMike Kravetz resv->region_cache_count--; 83996822904SAndy Whitcroft } 84096822904SAndy Whitcroft 841feba16e2SMike Kravetz if (!nrg) { 842feba16e2SMike Kravetz spin_unlock(&resv->lock); 843feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 844feba16e2SMike Kravetz if (!nrg) 845feba16e2SMike Kravetz return -ENOMEM; 846feba16e2SMike Kravetz goto retry; 847feba16e2SMike Kravetz } 848feba16e2SMike Kravetz 849feba16e2SMike Kravetz del += t - f; 85079aa925bSMike Kravetz hugetlb_cgroup_uncharge_file_region( 851d85aecf2SMiaohe Lin resv, rg, t - f, false); 852feba16e2SMike Kravetz 853feba16e2SMike Kravetz /* New entry for end of split region */ 854feba16e2SMike Kravetz nrg->from = t; 855feba16e2SMike Kravetz nrg->to = rg->to; 856075a61d0SMina Almasry 857075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 858075a61d0SMina Almasry 859feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 860feba16e2SMike Kravetz 861feba16e2SMike Kravetz /* Original entry is trimmed */ 862feba16e2SMike Kravetz rg->to = f; 863feba16e2SMike Kravetz 864feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 865feba16e2SMike Kravetz nrg = NULL; 86696822904SAndy Whitcroft break; 867feba16e2SMike Kravetz } 868feba16e2SMike Kravetz 869feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 870feba16e2SMike Kravetz del += rg->to - rg->from; 871075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 872d85aecf2SMiaohe Lin rg->to - rg->from, true); 87396822904SAndy Whitcroft list_del(&rg->link); 87496822904SAndy Whitcroft kfree(rg); 875feba16e2SMike Kravetz continue; 87696822904SAndy Whitcroft } 8777b24d861SDavidlohr Bueso 878feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 879075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 880d85aecf2SMiaohe Lin t - rg->from, false); 881075a61d0SMina Almasry 88279aa925bSMike Kravetz del += t - rg->from; 88379aa925bSMike Kravetz rg->from = t; 88479aa925bSMike Kravetz } else { /* Trim end of region */ 885075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 886d85aecf2SMiaohe Lin rg->to - f, false); 88779aa925bSMike Kravetz 88879aa925bSMike Kravetz del += rg->to - f; 88979aa925bSMike Kravetz rg->to = f; 890feba16e2SMike Kravetz } 891feba16e2SMike Kravetz } 892feba16e2SMike Kravetz 8937b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 894feba16e2SMike Kravetz kfree(nrg); 895feba16e2SMike Kravetz return del; 89696822904SAndy Whitcroft } 89796822904SAndy Whitcroft 8981dd308a7SMike Kravetz /* 899b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 900b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 901b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 902b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 903b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 904b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 905b5cec28dSMike Kravetz * counts. 906b5cec28dSMike Kravetz */ 90772e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 908b5cec28dSMike Kravetz { 909b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 910b5cec28dSMike Kravetz long rsv_adjust; 911da56388cSMiaohe Lin bool reserved = false; 912b5cec28dSMike Kravetz 913b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 914da56388cSMiaohe Lin if (rsv_adjust > 0) { 915b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 916b5cec28dSMike Kravetz 917da56388cSMiaohe Lin if (!hugetlb_acct_memory(h, 1)) 918da56388cSMiaohe Lin reserved = true; 919da56388cSMiaohe Lin } else if (!rsv_adjust) { 920da56388cSMiaohe Lin reserved = true; 921b5cec28dSMike Kravetz } 922da56388cSMiaohe Lin 923da56388cSMiaohe Lin if (!reserved) 924da56388cSMiaohe Lin pr_warn("hugetlb: Huge Page Reserved count may go negative.\n"); 925b5cec28dSMike Kravetz } 926b5cec28dSMike Kravetz 927b5cec28dSMike Kravetz /* 9281dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 9291dd308a7SMike Kravetz * that intersect with the range [f, t). 9301dd308a7SMike Kravetz */ 9311406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 93284afd99bSAndy Whitcroft { 9331406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 93484afd99bSAndy Whitcroft struct file_region *rg; 93584afd99bSAndy Whitcroft long chg = 0; 93684afd99bSAndy Whitcroft 9377b24d861SDavidlohr Bueso spin_lock(&resv->lock); 93884afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 93984afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 940f2135a4aSWang Sheng-Hui long seg_from; 941f2135a4aSWang Sheng-Hui long seg_to; 94284afd99bSAndy Whitcroft 94384afd99bSAndy Whitcroft if (rg->to <= f) 94484afd99bSAndy Whitcroft continue; 94584afd99bSAndy Whitcroft if (rg->from >= t) 94684afd99bSAndy Whitcroft break; 94784afd99bSAndy Whitcroft 94884afd99bSAndy Whitcroft seg_from = max(rg->from, f); 94984afd99bSAndy Whitcroft seg_to = min(rg->to, t); 95084afd99bSAndy Whitcroft 95184afd99bSAndy Whitcroft chg += seg_to - seg_from; 95284afd99bSAndy Whitcroft } 9537b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 95484afd99bSAndy Whitcroft 95584afd99bSAndy Whitcroft return chg; 95684afd99bSAndy Whitcroft } 95784afd99bSAndy Whitcroft 95896822904SAndy Whitcroft /* 959e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 960e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 961e7c4b0bfSAndy Whitcroft */ 962a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 963a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 964e7c4b0bfSAndy Whitcroft { 965a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 966a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 967e7c4b0bfSAndy Whitcroft } 968e7c4b0bfSAndy Whitcroft 9690fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 9700fe6e20bSNaoya Horiguchi unsigned long address) 9710fe6e20bSNaoya Horiguchi { 9720fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 9730fe6e20bSNaoya Horiguchi } 974dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 9750fe6e20bSNaoya Horiguchi 97684afd99bSAndy Whitcroft /* 97708fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 97808fba699SMel Gorman * cases this will be same size as used by the page table entries. 97908fba699SMel Gorman */ 98008fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 98108fba699SMel Gorman { 98205ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 98305ea8860SDan Williams return vma->vm_ops->pagesize(vma); 98408fba699SMel Gorman return PAGE_SIZE; 98508fba699SMel Gorman } 986f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 98708fba699SMel Gorman 98808fba699SMel Gorman /* 9893340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 9903340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 99109135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 99209135cc5SDan Williams * version of this symbol is required. 9933340289dSMel Gorman */ 99409135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 9953340289dSMel Gorman { 9963340289dSMel Gorman return vma_kernel_pagesize(vma); 9973340289dSMel Gorman } 9983340289dSMel Gorman 9993340289dSMel Gorman /* 100084afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 100184afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 100284afd99bSAndy Whitcroft * alignment. 100384afd99bSAndy Whitcroft */ 100484afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 100584afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 100604f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 100784afd99bSAndy Whitcroft 1008a1e78772SMel Gorman /* 1009a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 1010a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 1011a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 1012a1e78772SMel Gorman * 10138d9bfb26SMike Kravetz * With the exception of hugetlb_dup_vma_private() which is called at fork(), 1014a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 1015a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 1016a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 101784afd99bSAndy Whitcroft * 101884afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 101984afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 102084afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 102184afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 102284afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 102384afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 102484afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 102584afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 1026a1e78772SMel Gorman */ 1027e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 1028e7c4b0bfSAndy Whitcroft { 1029e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 1030e7c4b0bfSAndy Whitcroft } 1031e7c4b0bfSAndy Whitcroft 1032e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 1033e7c4b0bfSAndy Whitcroft unsigned long value) 1034e7c4b0bfSAndy Whitcroft { 1035e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 1036e7c4b0bfSAndy Whitcroft } 1037e7c4b0bfSAndy Whitcroft 1038e9fe92aeSMina Almasry static void 1039e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 1040e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 1041e9fe92aeSMina Almasry struct hstate *h) 1042e9fe92aeSMina Almasry { 1043e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 1044e9fe92aeSMina Almasry if (!h_cg || !h) { 1045e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 1046e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 1047e9fe92aeSMina Almasry resv_map->css = NULL; 1048e9fe92aeSMina Almasry } else { 1049e9fe92aeSMina Almasry resv_map->reservation_counter = 1050e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 1051e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 1052e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 1053e9fe92aeSMina Almasry } 1054e9fe92aeSMina Almasry #endif 1055e9fe92aeSMina Almasry } 1056e9fe92aeSMina Almasry 10579119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 105884afd99bSAndy Whitcroft { 105984afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 10605e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 10615e911373SMike Kravetz 10625e911373SMike Kravetz if (!resv_map || !rg) { 10635e911373SMike Kravetz kfree(resv_map); 10645e911373SMike Kravetz kfree(rg); 106584afd99bSAndy Whitcroft return NULL; 10665e911373SMike Kravetz } 106784afd99bSAndy Whitcroft 106884afd99bSAndy Whitcroft kref_init(&resv_map->refs); 10697b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 107084afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 107184afd99bSAndy Whitcroft 10725e911373SMike Kravetz resv_map->adds_in_progress = 0; 1073e9fe92aeSMina Almasry /* 1074e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 1075e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 1076e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 1077e9fe92aeSMina Almasry * reservations are to be un-charged from here. 1078e9fe92aeSMina Almasry */ 1079e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 10805e911373SMike Kravetz 10815e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 10825e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 10835e911373SMike Kravetz resv_map->region_cache_count = 1; 10845e911373SMike Kravetz 108584afd99bSAndy Whitcroft return resv_map; 108684afd99bSAndy Whitcroft } 108784afd99bSAndy Whitcroft 10889119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 108984afd99bSAndy Whitcroft { 109084afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 10915e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 10925e911373SMike Kravetz struct file_region *rg, *trg; 109384afd99bSAndy Whitcroft 109484afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 1095feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 10965e911373SMike Kravetz 10975e911373SMike Kravetz /* ... and any entries left in the cache */ 10985e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 10995e911373SMike Kravetz list_del(&rg->link); 11005e911373SMike Kravetz kfree(rg); 11015e911373SMike Kravetz } 11025e911373SMike Kravetz 11035e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 11045e911373SMike Kravetz 110584afd99bSAndy Whitcroft kfree(resv_map); 110684afd99bSAndy Whitcroft } 110784afd99bSAndy Whitcroft 11084e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 11094e35f483SJoonsoo Kim { 1110f27a5136SMike Kravetz /* 1111f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 1112f27a5136SMike Kravetz * address space within the inode. This original address space 1113f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 1114f27a5136SMike Kravetz * address space embedded within the inode. 1115f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 1116f27a5136SMike Kravetz * this may not be true for device special inodes. 1117f27a5136SMike Kravetz */ 1118f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 11194e35f483SJoonsoo Kim } 11204e35f483SJoonsoo Kim 112184afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 1122a1e78772SMel Gorman { 112381d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 11244e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 11254e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 11264e35f483SJoonsoo Kim struct inode *inode = mapping->host; 11274e35f483SJoonsoo Kim 11284e35f483SJoonsoo Kim return inode_resv_map(inode); 11294e35f483SJoonsoo Kim 11304e35f483SJoonsoo Kim } else { 113184afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 113284afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 11334e35f483SJoonsoo Kim } 1134a1e78772SMel Gorman } 1135a1e78772SMel Gorman 113684afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 1137a1e78772SMel Gorman { 113881d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 113981d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 1140a1e78772SMel Gorman 114184afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 114284afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 114304f2cbe3SMel Gorman } 114404f2cbe3SMel Gorman 114504f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 114604f2cbe3SMel Gorman { 114781d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 114881d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 1149e7c4b0bfSAndy Whitcroft 1150e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 115104f2cbe3SMel Gorman } 115204f2cbe3SMel Gorman 115304f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 115404f2cbe3SMel Gorman { 115581d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1156e7c4b0bfSAndy Whitcroft 1157e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 1158a1e78772SMel Gorman } 1159a1e78772SMel Gorman 11608d9bfb26SMike Kravetz void hugetlb_dup_vma_private(struct vm_area_struct *vma) 1161a1e78772SMel Gorman { 116281d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 11638d9bfb26SMike Kravetz /* 11648d9bfb26SMike Kravetz * Clear vm_private_data 1165612b8a31SMike Kravetz * - For shared mappings this is a per-vma semaphore that may be 1166612b8a31SMike Kravetz * allocated in a subsequent call to hugetlb_vm_op_open. 1167612b8a31SMike Kravetz * Before clearing, make sure pointer is not associated with vma 1168612b8a31SMike Kravetz * as this will leak the structure. This is the case when called 1169612b8a31SMike Kravetz * via clear_vma_resv_huge_pages() and hugetlb_vm_op_open has already 1170612b8a31SMike Kravetz * been called to allocate a new structure. 11718d9bfb26SMike Kravetz * - For MAP_PRIVATE mappings, this is the reserve map which does 11728d9bfb26SMike Kravetz * not apply to children. Faults generated by the children are 11738d9bfb26SMike Kravetz * not guaranteed to succeed, even if read-only. 11748d9bfb26SMike Kravetz */ 1175612b8a31SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 1176612b8a31SMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 1177612b8a31SMike Kravetz 1178612b8a31SMike Kravetz if (vma_lock && vma_lock->vma != vma) 1179612b8a31SMike Kravetz vma->vm_private_data = NULL; 1180612b8a31SMike Kravetz } else 1181612b8a31SMike Kravetz vma->vm_private_data = NULL; 1182a1e78772SMel Gorman } 1183a1e78772SMel Gorman 1184550a7d60SMina Almasry /* 1185550a7d60SMina Almasry * Reset and decrement one ref on hugepage private reservation. 1186*8651a137SLorenzo Stoakes * Called with mm->mmap_lock writer semaphore held. 1187550a7d60SMina Almasry * This function should be only used by move_vma() and operate on 1188550a7d60SMina Almasry * same sized vma. It should never come here with last ref on the 1189550a7d60SMina Almasry * reservation. 1190550a7d60SMina Almasry */ 1191550a7d60SMina Almasry void clear_vma_resv_huge_pages(struct vm_area_struct *vma) 1192550a7d60SMina Almasry { 1193550a7d60SMina Almasry /* 1194550a7d60SMina Almasry * Clear the old hugetlb private page reservation. 1195550a7d60SMina Almasry * It has already been transferred to new_vma. 1196550a7d60SMina Almasry * 1197550a7d60SMina Almasry * During a mremap() operation of a hugetlb vma we call move_vma() 1198550a7d60SMina Almasry * which copies vma into new_vma and unmaps vma. After the copy 1199550a7d60SMina Almasry * operation both new_vma and vma share a reference to the resv_map 1200550a7d60SMina Almasry * struct, and at that point vma is about to be unmapped. We don't 1201550a7d60SMina Almasry * want to return the reservation to the pool at unmap of vma because 1202550a7d60SMina Almasry * the reservation still lives on in new_vma, so simply decrement the 1203550a7d60SMina Almasry * ref here and remove the resv_map reference from this vma. 1204550a7d60SMina Almasry */ 1205550a7d60SMina Almasry struct resv_map *reservations = vma_resv_map(vma); 1206550a7d60SMina Almasry 1207afe041c2SBui Quang Minh if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 1208afe041c2SBui Quang Minh resv_map_put_hugetlb_cgroup_uncharge_info(reservations); 1209550a7d60SMina Almasry kref_put(&reservations->refs, resv_map_release); 1210afe041c2SBui Quang Minh } 1211550a7d60SMina Almasry 12128d9bfb26SMike Kravetz hugetlb_dup_vma_private(vma); 1213550a7d60SMina Almasry } 1214550a7d60SMina Almasry 1215a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 1216559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 1217a1e78772SMel Gorman { 1218af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 1219af0ed73eSJoonsoo Kim /* 1220af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 1221af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 1222af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 1223af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 1224af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 1225af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 1226af0ed73eSJoonsoo Kim * properly, so add work-around here. 1227af0ed73eSJoonsoo Kim */ 1228af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 1229559ec2f8SNicholas Krause return true; 1230af0ed73eSJoonsoo Kim else 1231559ec2f8SNicholas Krause return false; 1232af0ed73eSJoonsoo Kim } 1233a63884e9SJoonsoo Kim 1234a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 12351fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 12361fb1b0e9SMike Kravetz /* 12371fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 12381fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 12391fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 12407c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 12411fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 12421fb1b0e9SMike Kravetz */ 12431fb1b0e9SMike Kravetz if (chg) 12441fb1b0e9SMike Kravetz return false; 12451fb1b0e9SMike Kravetz else 1246559ec2f8SNicholas Krause return true; 12471fb1b0e9SMike Kravetz } 1248a63884e9SJoonsoo Kim 1249a63884e9SJoonsoo Kim /* 1250a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1251a63884e9SJoonsoo Kim * private mappings. 1252a63884e9SJoonsoo Kim */ 125367961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 125467961f9dSMike Kravetz /* 125567961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 125667961f9dSMike Kravetz * could have been performed on the private mapping. 125767961f9dSMike Kravetz * Examine the value of chg to determine if reserves 125867961f9dSMike Kravetz * actually exist or were previously consumed. 125967961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 126067961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 126167961f9dSMike Kravetz * private mappings has different (opposite) semantics 126267961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 126367961f9dSMike Kravetz * has already taken this difference in semantics into 126467961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 126567961f9dSMike Kravetz * as in the shared case above. Code could easily be 126667961f9dSMike Kravetz * combined, but keeping it separate draws attention to 126767961f9dSMike Kravetz * subtle differences. 126867961f9dSMike Kravetz */ 126967961f9dSMike Kravetz if (chg) 127067961f9dSMike Kravetz return false; 127167961f9dSMike Kravetz else 1272559ec2f8SNicholas Krause return true; 127367961f9dSMike Kravetz } 1274a63884e9SJoonsoo Kim 1275559ec2f8SNicholas Krause return false; 1276a1e78772SMel Gorman } 1277a1e78772SMel Gorman 1278240d67a8SSidhartha Kumar static void enqueue_hugetlb_folio(struct hstate *h, struct folio *folio) 12791da177e4SLinus Torvalds { 1280240d67a8SSidhartha Kumar int nid = folio_nid(folio); 12819487ca60SMike Kravetz 12829487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1283240d67a8SSidhartha Kumar VM_BUG_ON_FOLIO(folio_ref_count(folio), folio); 1284b65a4edaSMike Kravetz 1285240d67a8SSidhartha Kumar list_move(&folio->lru, &h->hugepage_freelists[nid]); 1286a5516438SAndi Kleen h->free_huge_pages++; 1287a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 1288240d67a8SSidhartha Kumar folio_set_hugetlb_freed(folio); 12891da177e4SLinus Torvalds } 12901da177e4SLinus Torvalds 129194310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1292bf50bab2SNaoya Horiguchi { 1293bf50bab2SNaoya Horiguchi struct page *page; 12941a08ae36SPavel Tatashin bool pin = !!(current->flags & PF_MEMALLOC_PIN); 1295bf50bab2SNaoya Horiguchi 12969487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1297bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 12986077c943SAlex Sierra if (pin && !is_longterm_pinnable_page(page)) 1299bbe88753SJoonsoo Kim continue; 1300bbe88753SJoonsoo Kim 13016664bfc8SWei Yang if (PageHWPoison(page)) 13026664bfc8SWei Yang continue; 1303bbe88753SJoonsoo Kim 13040edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1305a9869b83SNaoya Horiguchi set_page_refcounted(page); 13066c037149SMike Kravetz ClearHPageFreed(page); 1307bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1308bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1309bf50bab2SNaoya Horiguchi return page; 1310bf50bab2SNaoya Horiguchi } 1311bf50bab2SNaoya Horiguchi 13126664bfc8SWei Yang return NULL; 13136664bfc8SWei Yang } 13146664bfc8SWei Yang 13153e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 13163e59fcb0SMichal Hocko nodemask_t *nmask) 131794310cbcSAnshuman Khandual { 13183e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 13193e59fcb0SMichal Hocko struct zonelist *zonelist; 13203e59fcb0SMichal Hocko struct zone *zone; 13213e59fcb0SMichal Hocko struct zoneref *z; 132298fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 13233e59fcb0SMichal Hocko 13243e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 13253e59fcb0SMichal Hocko 13263e59fcb0SMichal Hocko retry_cpuset: 13273e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 13283e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 132994310cbcSAnshuman Khandual struct page *page; 133094310cbcSAnshuman Khandual 13313e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 13323e59fcb0SMichal Hocko continue; 13333e59fcb0SMichal Hocko /* 13343e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 13353e59fcb0SMichal Hocko * zone aware 13363e59fcb0SMichal Hocko */ 13373e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 13383e59fcb0SMichal Hocko continue; 13393e59fcb0SMichal Hocko node = zone_to_nid(zone); 134094310cbcSAnshuman Khandual 134194310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 134294310cbcSAnshuman Khandual if (page) 134394310cbcSAnshuman Khandual return page; 134494310cbcSAnshuman Khandual } 13453e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 13463e59fcb0SMichal Hocko goto retry_cpuset; 13473e59fcb0SMichal Hocko 134894310cbcSAnshuman Khandual return NULL; 134994310cbcSAnshuman Khandual } 135094310cbcSAnshuman Khandual 13518346d69dSXin Hao static unsigned long available_huge_pages(struct hstate *h) 13528346d69dSXin Hao { 13538346d69dSXin Hao return h->free_huge_pages - h->resv_huge_pages; 13548346d69dSXin Hao } 13558346d69dSXin Hao 1356a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1357a5516438SAndi Kleen struct vm_area_struct *vma, 1358af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1359af0ed73eSJoonsoo Kim long chg) 13601da177e4SLinus Torvalds { 1361cfcaa66fSBen Widawsky struct page *page = NULL; 1362480eccf9SLee Schermerhorn struct mempolicy *mpol; 136304ec6264SVlastimil Babka gfp_t gfp_mask; 13643e59fcb0SMichal Hocko nodemask_t *nodemask; 136504ec6264SVlastimil Babka int nid; 13661da177e4SLinus Torvalds 1367a1e78772SMel Gorman /* 1368a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1369a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1370a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1371a1e78772SMel Gorman */ 13728346d69dSXin Hao if (!vma_has_reserves(vma, chg) && !available_huge_pages(h)) 1373c0ff7453SMiao Xie goto err; 1374a1e78772SMel Gorman 137504f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 13768346d69dSXin Hao if (avoid_reserve && !available_huge_pages(h)) 13776eab04a8SJustin P. Mattock goto err; 137804f2cbe3SMel Gorman 137904ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 138004ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 1381cfcaa66fSBen Widawsky 1382cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 13833e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1384cfcaa66fSBen Widawsky 1385cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 1386cfcaa66fSBen Widawsky nodemask = NULL; 1387cfcaa66fSBen Widawsky } 1388cfcaa66fSBen Widawsky 1389cfcaa66fSBen Widawsky if (!page) 1390cfcaa66fSBen Widawsky page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1391cfcaa66fSBen Widawsky 13923e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 1393d6995da3SMike Kravetz SetHPageRestoreReserve(page); 1394a63884e9SJoonsoo Kim h->resv_huge_pages--; 1395bf50bab2SNaoya Horiguchi } 1396cc9a6c87SMel Gorman 1397cc9a6c87SMel Gorman mpol_cond_put(mpol); 1398cc9a6c87SMel Gorman return page; 1399cc9a6c87SMel Gorman 1400c0ff7453SMiao Xie err: 1401cc9a6c87SMel Gorman return NULL; 14021da177e4SLinus Torvalds } 14031da177e4SLinus Torvalds 14041cac6f2cSLuiz Capitulino /* 14051cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 14061cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 14071cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 14081cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 14091cac6f2cSLuiz Capitulino * node for alloc or free. 14101cac6f2cSLuiz Capitulino */ 14111cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 14121cac6f2cSLuiz Capitulino { 14130edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 14141cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 14151cac6f2cSLuiz Capitulino 14161cac6f2cSLuiz Capitulino return nid; 14171cac6f2cSLuiz Capitulino } 14181cac6f2cSLuiz Capitulino 14191cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 14201cac6f2cSLuiz Capitulino { 14211cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 14221cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 14231cac6f2cSLuiz Capitulino return nid; 14241cac6f2cSLuiz Capitulino } 14251cac6f2cSLuiz Capitulino 14261cac6f2cSLuiz Capitulino /* 14271cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 14281cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 14291cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 14301cac6f2cSLuiz Capitulino * mask. 14311cac6f2cSLuiz Capitulino */ 14321cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 14331cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 14341cac6f2cSLuiz Capitulino { 14351cac6f2cSLuiz Capitulino int nid; 14361cac6f2cSLuiz Capitulino 14371cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 14381cac6f2cSLuiz Capitulino 14391cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 14401cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 14411cac6f2cSLuiz Capitulino 14421cac6f2cSLuiz Capitulino return nid; 14431cac6f2cSLuiz Capitulino } 14441cac6f2cSLuiz Capitulino 14451cac6f2cSLuiz Capitulino /* 144610c6ec49SMike Kravetz * helper for remove_pool_huge_page() - return the previously saved 14471cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 14481cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 14491cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 14501cac6f2cSLuiz Capitulino */ 14511cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 14521cac6f2cSLuiz Capitulino { 14531cac6f2cSLuiz Capitulino int nid; 14541cac6f2cSLuiz Capitulino 14551cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 14561cac6f2cSLuiz Capitulino 14571cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 14581cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 14591cac6f2cSLuiz Capitulino 14601cac6f2cSLuiz Capitulino return nid; 14611cac6f2cSLuiz Capitulino } 14621cac6f2cSLuiz Capitulino 14631cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 14641cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 14651cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 14661cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 14671cac6f2cSLuiz Capitulino nr_nodes--) 14681cac6f2cSLuiz Capitulino 14691cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 14701cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 14711cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 14721cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 14731cac6f2cSLuiz Capitulino nr_nodes--) 14741cac6f2cSLuiz Capitulino 14758531fc6fSMike Kravetz /* used to demote non-gigantic_huge pages as well */ 1476911565b8SSidhartha Kumar static void __destroy_compound_gigantic_folio(struct folio *folio, 147734d9e35bSMike Kravetz unsigned int order, bool demote) 1478944d9fecSLuiz Capitulino { 1479944d9fecSLuiz Capitulino int i; 1480944d9fecSLuiz Capitulino int nr_pages = 1 << order; 148114455eabSCheng Li struct page *p; 1482944d9fecSLuiz Capitulino 1483911565b8SSidhartha Kumar atomic_set(folio_mapcount_ptr(folio), 0); 1484911565b8SSidhartha Kumar atomic_set(folio_subpages_mapcount_ptr(folio), 0); 1485911565b8SSidhartha Kumar atomic_set(folio_pincount_ptr(folio), 0); 148647e29d32SJohn Hubbard 148714455eabSCheng Li for (i = 1; i < nr_pages; i++) { 1488911565b8SSidhartha Kumar p = folio_page(folio, i); 1489a01f4390SMike Kravetz p->mapping = NULL; 14901d798ca3SKirill A. Shutemov clear_compound_head(p); 149134d9e35bSMike Kravetz if (!demote) 1492944d9fecSLuiz Capitulino set_page_refcounted(p); 1493944d9fecSLuiz Capitulino } 1494944d9fecSLuiz Capitulino 1495911565b8SSidhartha Kumar folio_set_compound_order(folio, 0); 1496911565b8SSidhartha Kumar __folio_clear_head(folio); 1497944d9fecSLuiz Capitulino } 1498944d9fecSLuiz Capitulino 1499911565b8SSidhartha Kumar static void destroy_compound_hugetlb_folio_for_demote(struct folio *folio, 15008531fc6fSMike Kravetz unsigned int order) 15018531fc6fSMike Kravetz { 1502911565b8SSidhartha Kumar __destroy_compound_gigantic_folio(folio, order, true); 15038531fc6fSMike Kravetz } 15048531fc6fSMike Kravetz 15058531fc6fSMike Kravetz #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 1506911565b8SSidhartha Kumar static void destroy_compound_gigantic_folio(struct folio *folio, 150734d9e35bSMike Kravetz unsigned int order) 150834d9e35bSMike Kravetz { 1509911565b8SSidhartha Kumar __destroy_compound_gigantic_folio(folio, order, false); 151034d9e35bSMike Kravetz } 151134d9e35bSMike Kravetz 15127f325a8dSSidhartha Kumar static void free_gigantic_folio(struct folio *folio, unsigned int order) 1513944d9fecSLuiz Capitulino { 1514cf11e85fSRoman Gushchin /* 1515cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1516cf11e85fSRoman Gushchin * cma_release() returns false. 1517cf11e85fSRoman Gushchin */ 1518dbda8feaSBarry Song #ifdef CONFIG_CMA 15197f325a8dSSidhartha Kumar int nid = folio_nid(folio); 15207f325a8dSSidhartha Kumar 15217f325a8dSSidhartha Kumar if (cma_release(hugetlb_cma[nid], &folio->page, 1 << order)) 1522cf11e85fSRoman Gushchin return; 1523dbda8feaSBarry Song #endif 1524cf11e85fSRoman Gushchin 15257f325a8dSSidhartha Kumar free_contig_range(folio_pfn(folio), 1 << order); 1526944d9fecSLuiz Capitulino } 1527944d9fecSLuiz Capitulino 15284eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 152919fc1a7eSSidhartha Kumar static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask, 1530d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1531944d9fecSLuiz Capitulino { 153219fc1a7eSSidhartha Kumar struct page *page; 153304adbc3fSMiaohe Lin unsigned long nr_pages = pages_per_huge_page(h); 1534953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1535953f064aSLi Xinhai nid = numa_mem_id(); 1536944d9fecSLuiz Capitulino 1537dbda8feaSBarry Song #ifdef CONFIG_CMA 1538dbda8feaSBarry Song { 1539cf11e85fSRoman Gushchin int node; 1540cf11e85fSRoman Gushchin 1541953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1542953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1543953f064aSLi Xinhai huge_page_order(h), true); 1544953f064aSLi Xinhai if (page) 154519fc1a7eSSidhartha Kumar return page_folio(page); 1546953f064aSLi Xinhai } 1547953f064aSLi Xinhai 1548953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1549cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1550953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1551cf11e85fSRoman Gushchin continue; 1552cf11e85fSRoman Gushchin 1553cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1554cf11e85fSRoman Gushchin huge_page_order(h), true); 1555cf11e85fSRoman Gushchin if (page) 155619fc1a7eSSidhartha Kumar return page_folio(page); 1557cf11e85fSRoman Gushchin } 1558cf11e85fSRoman Gushchin } 1559953f064aSLi Xinhai } 1560dbda8feaSBarry Song #endif 1561cf11e85fSRoman Gushchin 156219fc1a7eSSidhartha Kumar page = alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 156319fc1a7eSSidhartha Kumar return page ? page_folio(page) : NULL; 1564944d9fecSLuiz Capitulino } 1565944d9fecSLuiz Capitulino 15664eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 156719fc1a7eSSidhartha Kumar static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask, 15684eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 15694eb0716eSAlexandre Ghiti { 15704eb0716eSAlexandre Ghiti return NULL; 15714eb0716eSAlexandre Ghiti } 15724eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1573944d9fecSLuiz Capitulino 1574e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 157519fc1a7eSSidhartha Kumar static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask, 15764eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 15774eb0716eSAlexandre Ghiti { 15784eb0716eSAlexandre Ghiti return NULL; 15794eb0716eSAlexandre Ghiti } 15807f325a8dSSidhartha Kumar static inline void free_gigantic_folio(struct folio *folio, 15817f325a8dSSidhartha Kumar unsigned int order) { } 1582911565b8SSidhartha Kumar static inline void destroy_compound_gigantic_folio(struct folio *folio, 1583d00181b9SKirill A. Shutemov unsigned int order) { } 1584944d9fecSLuiz Capitulino #endif 1585944d9fecSLuiz Capitulino 15866eb4e88aSMike Kravetz /* 1587cfd5082bSSidhartha Kumar * Remove hugetlb folio from lists, and update dtor so that the folio appears 158834d9e35bSMike Kravetz * as just a compound page. 158934d9e35bSMike Kravetz * 1590cfd5082bSSidhartha Kumar * A reference is held on the folio, except in the case of demote. 15916eb4e88aSMike Kravetz * 15926eb4e88aSMike Kravetz * Must be called with hugetlb lock held. 15936eb4e88aSMike Kravetz */ 1594cfd5082bSSidhartha Kumar static void __remove_hugetlb_folio(struct hstate *h, struct folio *folio, 159534d9e35bSMike Kravetz bool adjust_surplus, 159634d9e35bSMike Kravetz bool demote) 15976eb4e88aSMike Kravetz { 1598cfd5082bSSidhartha Kumar int nid = folio_nid(folio); 15996eb4e88aSMike Kravetz 1600f074732dSSidhartha Kumar VM_BUG_ON_FOLIO(hugetlb_cgroup_from_folio(folio), folio); 1601f074732dSSidhartha Kumar VM_BUG_ON_FOLIO(hugetlb_cgroup_from_folio_rsvd(folio), folio); 16026eb4e88aSMike Kravetz 16039487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 16046eb4e88aSMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 16056eb4e88aSMike Kravetz return; 16066eb4e88aSMike Kravetz 1607cfd5082bSSidhartha Kumar list_del(&folio->lru); 16086eb4e88aSMike Kravetz 1609cfd5082bSSidhartha Kumar if (folio_test_hugetlb_freed(folio)) { 16106eb4e88aSMike Kravetz h->free_huge_pages--; 16116eb4e88aSMike Kravetz h->free_huge_pages_node[nid]--; 16126eb4e88aSMike Kravetz } 16136eb4e88aSMike Kravetz if (adjust_surplus) { 16146eb4e88aSMike Kravetz h->surplus_huge_pages--; 16156eb4e88aSMike Kravetz h->surplus_huge_pages_node[nid]--; 16166eb4e88aSMike Kravetz } 16176eb4e88aSMike Kravetz 1618e32d20c0SMike Kravetz /* 1619e32d20c0SMike Kravetz * Very subtle 1620e32d20c0SMike Kravetz * 1621e32d20c0SMike Kravetz * For non-gigantic pages set the destructor to the normal compound 1622e32d20c0SMike Kravetz * page dtor. This is needed in case someone takes an additional 1623e32d20c0SMike Kravetz * temporary ref to the page, and freeing is delayed until they drop 1624e32d20c0SMike Kravetz * their reference. 1625e32d20c0SMike Kravetz * 1626e32d20c0SMike Kravetz * For gigantic pages set the destructor to the null dtor. This 1627e32d20c0SMike Kravetz * destructor will never be called. Before freeing the gigantic 1628911565b8SSidhartha Kumar * page destroy_compound_gigantic_folio will turn the folio into a 1629911565b8SSidhartha Kumar * simple group of pages. After this the destructor does not 1630e32d20c0SMike Kravetz * apply. 1631e32d20c0SMike Kravetz * 1632e32d20c0SMike Kravetz * This handles the case where more than one ref is held when and 1633d6ef19e2SSidhartha Kumar * after update_and_free_hugetlb_folio is called. 163434d9e35bSMike Kravetz * 163534d9e35bSMike Kravetz * In the case of demote we do not ref count the page as it will soon 163634d9e35bSMike Kravetz * be turned into a page of smaller size. 1637e32d20c0SMike Kravetz */ 163834d9e35bSMike Kravetz if (!demote) 1639cfd5082bSSidhartha Kumar folio_ref_unfreeze(folio, 1); 1640e32d20c0SMike Kravetz if (hstate_is_gigantic(h)) 1641cfd5082bSSidhartha Kumar folio_set_compound_dtor(folio, NULL_COMPOUND_DTOR); 1642e32d20c0SMike Kravetz else 1643cfd5082bSSidhartha Kumar folio_set_compound_dtor(folio, COMPOUND_PAGE_DTOR); 16446eb4e88aSMike Kravetz 16456eb4e88aSMike Kravetz h->nr_huge_pages--; 16466eb4e88aSMike Kravetz h->nr_huge_pages_node[nid]--; 16476eb4e88aSMike Kravetz } 16486eb4e88aSMike Kravetz 1649cfd5082bSSidhartha Kumar static void remove_hugetlb_folio(struct hstate *h, struct folio *folio, 165034d9e35bSMike Kravetz bool adjust_surplus) 165134d9e35bSMike Kravetz { 1652cfd5082bSSidhartha Kumar __remove_hugetlb_folio(h, folio, adjust_surplus, false); 165334d9e35bSMike Kravetz } 165434d9e35bSMike Kravetz 1655cfd5082bSSidhartha Kumar static void remove_hugetlb_folio_for_demote(struct hstate *h, struct folio *folio, 16568531fc6fSMike Kravetz bool adjust_surplus) 16578531fc6fSMike Kravetz { 1658cfd5082bSSidhartha Kumar __remove_hugetlb_folio(h, folio, adjust_surplus, true); 16598531fc6fSMike Kravetz } 16608531fc6fSMike Kravetz 16612f6c57d6SSidhartha Kumar static void add_hugetlb_folio(struct hstate *h, struct folio *folio, 1662ad2fa371SMuchun Song bool adjust_surplus) 1663ad2fa371SMuchun Song { 1664ad2fa371SMuchun Song int zeroed; 16652f6c57d6SSidhartha Kumar int nid = folio_nid(folio); 1666ad2fa371SMuchun Song 16672f6c57d6SSidhartha Kumar VM_BUG_ON_FOLIO(!folio_test_hugetlb_vmemmap_optimized(folio), folio); 1668ad2fa371SMuchun Song 1669ad2fa371SMuchun Song lockdep_assert_held(&hugetlb_lock); 1670ad2fa371SMuchun Song 16712f6c57d6SSidhartha Kumar INIT_LIST_HEAD(&folio->lru); 1672ad2fa371SMuchun Song h->nr_huge_pages++; 1673ad2fa371SMuchun Song h->nr_huge_pages_node[nid]++; 1674ad2fa371SMuchun Song 1675ad2fa371SMuchun Song if (adjust_surplus) { 1676ad2fa371SMuchun Song h->surplus_huge_pages++; 1677ad2fa371SMuchun Song h->surplus_huge_pages_node[nid]++; 1678ad2fa371SMuchun Song } 1679ad2fa371SMuchun Song 16802f6c57d6SSidhartha Kumar folio_set_compound_dtor(folio, HUGETLB_PAGE_DTOR); 16812f6c57d6SSidhartha Kumar folio_change_private(folio, NULL); 1682a9e1eab2SMiaohe Lin /* 16832f6c57d6SSidhartha Kumar * We have to set hugetlb_vmemmap_optimized again as above 16842f6c57d6SSidhartha Kumar * folio_change_private(folio, NULL) cleared it. 1685a9e1eab2SMiaohe Lin */ 16862f6c57d6SSidhartha Kumar folio_set_hugetlb_vmemmap_optimized(folio); 1687ad2fa371SMuchun Song 1688ad2fa371SMuchun Song /* 16892f6c57d6SSidhartha Kumar * This folio is about to be managed by the hugetlb allocator and 1690b65a4edaSMike Kravetz * should have no users. Drop our reference, and check for others 1691b65a4edaSMike Kravetz * just in case. 1692ad2fa371SMuchun Song */ 16932f6c57d6SSidhartha Kumar zeroed = folio_put_testzero(folio); 16942f6c57d6SSidhartha Kumar if (unlikely(!zeroed)) 1695b65a4edaSMike Kravetz /* 1696b65a4edaSMike Kravetz * It is VERY unlikely soneone else has taken a ref on 1697b65a4edaSMike Kravetz * the page. In this case, we simply return as the 1698b65a4edaSMike Kravetz * hugetlb destructor (free_huge_page) will be called 1699b65a4edaSMike Kravetz * when this other ref is dropped. 1700b65a4edaSMike Kravetz */ 1701b65a4edaSMike Kravetz return; 1702b65a4edaSMike Kravetz 17032f6c57d6SSidhartha Kumar arch_clear_hugepage_flags(&folio->page); 1704240d67a8SSidhartha Kumar enqueue_hugetlb_folio(h, folio); 1705ad2fa371SMuchun Song } 1706ad2fa371SMuchun Song 1707b65d4adbSMuchun Song static void __update_and_free_page(struct hstate *h, struct page *page) 17086af2acb6SAdam Litke { 17096af2acb6SAdam Litke int i; 1710911565b8SSidhartha Kumar struct folio *folio = page_folio(page); 171114455eabSCheng Li struct page *subpage; 1712a5516438SAndi Kleen 17134eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1714944d9fecSLuiz Capitulino return; 171518229df5SAndy Whitcroft 1716161df60eSNaoya Horiguchi /* 1717161df60eSNaoya Horiguchi * If we don't know which subpages are hwpoisoned, we can't free 1718161df60eSNaoya Horiguchi * the hugepage, so it's leaked intentionally. 1719161df60eSNaoya Horiguchi */ 17207f325a8dSSidhartha Kumar if (folio_test_hugetlb_raw_hwp_unreliable(folio)) 1721161df60eSNaoya Horiguchi return; 1722161df60eSNaoya Horiguchi 17236213834cSMuchun Song if (hugetlb_vmemmap_restore(h, page)) { 1724ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 1725ad2fa371SMuchun Song /* 1726ad2fa371SMuchun Song * If we cannot allocate vmemmap pages, just refuse to free the 1727ad2fa371SMuchun Song * page and put the page back on the hugetlb free list and treat 1728ad2fa371SMuchun Song * as a surplus page. 1729ad2fa371SMuchun Song */ 17307f325a8dSSidhartha Kumar add_hugetlb_folio(h, folio, true); 1731ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1732ad2fa371SMuchun Song return; 1733ad2fa371SMuchun Song } 1734ad2fa371SMuchun Song 1735161df60eSNaoya Horiguchi /* 1736161df60eSNaoya Horiguchi * Move PageHWPoison flag from head page to the raw error pages, 1737161df60eSNaoya Horiguchi * which makes any healthy subpages reusable. 1738161df60eSNaoya Horiguchi */ 1739911565b8SSidhartha Kumar if (unlikely(folio_test_hwpoison(folio))) 1740911565b8SSidhartha Kumar hugetlb_clear_page_hwpoison(&folio->page); 1741161df60eSNaoya Horiguchi 174214455eabSCheng Li for (i = 0; i < pages_per_huge_page(h); i++) { 17437f325a8dSSidhartha Kumar subpage = folio_page(folio, i); 1744dbfee5aeSMike Kravetz subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 174532f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1746a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1747a7407a27SLuiz Capitulino 1 << PG_writeback); 17486af2acb6SAdam Litke } 1749a01f4390SMike Kravetz 1750a01f4390SMike Kravetz /* 1751a01f4390SMike Kravetz * Non-gigantic pages demoted from CMA allocated gigantic pages 17527f325a8dSSidhartha Kumar * need to be given back to CMA in free_gigantic_folio. 1753a01f4390SMike Kravetz */ 1754a01f4390SMike Kravetz if (hstate_is_gigantic(h) || 17552f6c57d6SSidhartha Kumar hugetlb_cma_folio(folio, huge_page_order(h))) { 1756911565b8SSidhartha Kumar destroy_compound_gigantic_folio(folio, huge_page_order(h)); 17577f325a8dSSidhartha Kumar free_gigantic_folio(folio, huge_page_order(h)); 1758944d9fecSLuiz Capitulino } else { 1759a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 17606af2acb6SAdam Litke } 1761944d9fecSLuiz Capitulino } 17626af2acb6SAdam Litke 1763b65d4adbSMuchun Song /* 1764d6ef19e2SSidhartha Kumar * As update_and_free_hugetlb_folio() can be called under any context, so we cannot 1765b65d4adbSMuchun Song * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the 1766b65d4adbSMuchun Song * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate 1767b65d4adbSMuchun Song * the vmemmap pages. 1768b65d4adbSMuchun Song * 1769b65d4adbSMuchun Song * free_hpage_workfn() locklessly retrieves the linked list of pages to be 1770b65d4adbSMuchun Song * freed and frees them one-by-one. As the page->mapping pointer is going 1771b65d4adbSMuchun Song * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node 1772b65d4adbSMuchun Song * structure of a lockless linked list of huge pages to be freed. 1773b65d4adbSMuchun Song */ 1774b65d4adbSMuchun Song static LLIST_HEAD(hpage_freelist); 1775b65d4adbSMuchun Song 1776b65d4adbSMuchun Song static void free_hpage_workfn(struct work_struct *work) 1777b65d4adbSMuchun Song { 1778b65d4adbSMuchun Song struct llist_node *node; 1779b65d4adbSMuchun Song 1780b65d4adbSMuchun Song node = llist_del_all(&hpage_freelist); 1781b65d4adbSMuchun Song 1782b65d4adbSMuchun Song while (node) { 1783b65d4adbSMuchun Song struct page *page; 1784b65d4adbSMuchun Song struct hstate *h; 1785b65d4adbSMuchun Song 1786b65d4adbSMuchun Song page = container_of((struct address_space **)node, 1787b65d4adbSMuchun Song struct page, mapping); 1788b65d4adbSMuchun Song node = node->next; 1789b65d4adbSMuchun Song page->mapping = NULL; 1790b65d4adbSMuchun Song /* 1791b65d4adbSMuchun Song * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate() 1792b65d4adbSMuchun Song * is going to trigger because a previous call to 1793cfd5082bSSidhartha Kumar * remove_hugetlb_folio() will call folio_set_compound_dtor 1794cfd5082bSSidhartha Kumar * (folio, NULL_COMPOUND_DTOR), so do not use page_hstate() 1795cfd5082bSSidhartha Kumar * directly. 1796b65d4adbSMuchun Song */ 1797b65d4adbSMuchun Song h = size_to_hstate(page_size(page)); 1798b65d4adbSMuchun Song 1799b65d4adbSMuchun Song __update_and_free_page(h, page); 1800b65d4adbSMuchun Song 1801b65d4adbSMuchun Song cond_resched(); 1802b65d4adbSMuchun Song } 1803b65d4adbSMuchun Song } 1804b65d4adbSMuchun Song static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1805b65d4adbSMuchun Song 1806b65d4adbSMuchun Song static inline void flush_free_hpage_work(struct hstate *h) 1807b65d4adbSMuchun Song { 18086213834cSMuchun Song if (hugetlb_vmemmap_optimizable(h)) 1809b65d4adbSMuchun Song flush_work(&free_hpage_work); 1810b65d4adbSMuchun Song } 1811b65d4adbSMuchun Song 1812d6ef19e2SSidhartha Kumar static void update_and_free_hugetlb_folio(struct hstate *h, struct folio *folio, 1813b65d4adbSMuchun Song bool atomic) 1814b65d4adbSMuchun Song { 1815d6ef19e2SSidhartha Kumar if (!folio_test_hugetlb_vmemmap_optimized(folio) || !atomic) { 1816d6ef19e2SSidhartha Kumar __update_and_free_page(h, &folio->page); 1817b65d4adbSMuchun Song return; 1818b65d4adbSMuchun Song } 1819b65d4adbSMuchun Song 1820b65d4adbSMuchun Song /* 1821b65d4adbSMuchun Song * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages. 1822b65d4adbSMuchun Song * 1823b65d4adbSMuchun Song * Only call schedule_work() if hpage_freelist is previously 1824b65d4adbSMuchun Song * empty. Otherwise, schedule_work() had been called but the workfn 1825b65d4adbSMuchun Song * hasn't retrieved the list yet. 1826b65d4adbSMuchun Song */ 1827d6ef19e2SSidhartha Kumar if (llist_add((struct llist_node *)&folio->mapping, &hpage_freelist)) 1828b65d4adbSMuchun Song schedule_work(&free_hpage_work); 1829b65d4adbSMuchun Song } 1830b65d4adbSMuchun Song 183110c6ec49SMike Kravetz static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list) 183210c6ec49SMike Kravetz { 183310c6ec49SMike Kravetz struct page *page, *t_page; 1834d6ef19e2SSidhartha Kumar struct folio *folio; 183510c6ec49SMike Kravetz 183610c6ec49SMike Kravetz list_for_each_entry_safe(page, t_page, list, lru) { 1837d6ef19e2SSidhartha Kumar folio = page_folio(page); 1838d6ef19e2SSidhartha Kumar update_and_free_hugetlb_folio(h, folio, false); 183910c6ec49SMike Kravetz cond_resched(); 184010c6ec49SMike Kravetz } 184110c6ec49SMike Kravetz } 184210c6ec49SMike Kravetz 1843e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1844e5ff2159SAndi Kleen { 1845e5ff2159SAndi Kleen struct hstate *h; 1846e5ff2159SAndi Kleen 1847e5ff2159SAndi Kleen for_each_hstate(h) { 1848e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1849e5ff2159SAndi Kleen return h; 1850e5ff2159SAndi Kleen } 1851e5ff2159SAndi Kleen return NULL; 1852e5ff2159SAndi Kleen } 1853e5ff2159SAndi Kleen 1854db71ef79SMike Kravetz void free_huge_page(struct page *page) 185527a85ef1SDavid Gibson { 1856a5516438SAndi Kleen /* 1857a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1858a5516438SAndi Kleen * compound page destructor. 1859a5516438SAndi Kleen */ 18600356c4b9SSidhartha Kumar struct folio *folio = page_folio(page); 18610356c4b9SSidhartha Kumar struct hstate *h = folio_hstate(folio); 18620356c4b9SSidhartha Kumar int nid = folio_nid(folio); 18630356c4b9SSidhartha Kumar struct hugepage_subpool *spool = hugetlb_folio_subpool(folio); 186407443a85SJoonsoo Kim bool restore_reserve; 1865db71ef79SMike Kravetz unsigned long flags; 186627a85ef1SDavid Gibson 18670356c4b9SSidhartha Kumar VM_BUG_ON_FOLIO(folio_ref_count(folio), folio); 18680356c4b9SSidhartha Kumar VM_BUG_ON_FOLIO(folio_mapcount(folio), folio); 18698ace22bcSYongkai Wu 18700356c4b9SSidhartha Kumar hugetlb_set_folio_subpool(folio, NULL); 18710356c4b9SSidhartha Kumar if (folio_test_anon(folio)) 18720356c4b9SSidhartha Kumar __ClearPageAnonExclusive(&folio->page); 18730356c4b9SSidhartha Kumar folio->mapping = NULL; 18740356c4b9SSidhartha Kumar restore_reserve = folio_test_hugetlb_restore_reserve(folio); 18750356c4b9SSidhartha Kumar folio_clear_hugetlb_restore_reserve(folio); 187627a85ef1SDavid Gibson 18771c5ecae3SMike Kravetz /* 1878d6995da3SMike Kravetz * If HPageRestoreReserve was set on page, page allocation consumed a 18790919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 18800919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 18810919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 18826c26d310SMiaohe Lin * reservation, do not call hugepage_subpool_put_pages() as this will 18830919e1b6SMike Kravetz * remove the reserved page from the subpool. 18840919e1b6SMike Kravetz */ 18850919e1b6SMike Kravetz if (!restore_reserve) { 18860919e1b6SMike Kravetz /* 18870919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 18880919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 18890919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 18900919e1b6SMike Kravetz * operation. 18911c5ecae3SMike Kravetz */ 18921c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 18931c5ecae3SMike Kravetz restore_reserve = true; 18940919e1b6SMike Kravetz } 18951c5ecae3SMike Kravetz 1896db71ef79SMike Kravetz spin_lock_irqsave(&hugetlb_lock, flags); 18970356c4b9SSidhartha Kumar folio_clear_hugetlb_migratable(folio); 1898d4ab0316SSidhartha Kumar hugetlb_cgroup_uncharge_folio(hstate_index(h), 1899d4ab0316SSidhartha Kumar pages_per_huge_page(h), folio); 1900d4ab0316SSidhartha Kumar hugetlb_cgroup_uncharge_folio_rsvd(hstate_index(h), 1901d4ab0316SSidhartha Kumar pages_per_huge_page(h), folio); 190207443a85SJoonsoo Kim if (restore_reserve) 190307443a85SJoonsoo Kim h->resv_huge_pages++; 190407443a85SJoonsoo Kim 19050356c4b9SSidhartha Kumar if (folio_test_hugetlb_temporary(folio)) { 1906cfd5082bSSidhartha Kumar remove_hugetlb_folio(h, folio, false); 1907db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1908d6ef19e2SSidhartha Kumar update_and_free_hugetlb_folio(h, folio, true); 1909ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 19100edaecfaSAneesh Kumar K.V /* remove the page from active list */ 1911cfd5082bSSidhartha Kumar remove_hugetlb_folio(h, folio, true); 1912db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1913d6ef19e2SSidhartha Kumar update_and_free_hugetlb_folio(h, folio, true); 19147893d1d5SAdam Litke } else { 19155d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1916240d67a8SSidhartha Kumar enqueue_hugetlb_folio(h, folio); 1917db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 191827a85ef1SDavid Gibson } 19191121828aSMike Kravetz } 192027a85ef1SDavid Gibson 1921d3d99fccSOscar Salvador /* 1922d3d99fccSOscar Salvador * Must be called with the hugetlb lock held 1923d3d99fccSOscar Salvador */ 1924d3d99fccSOscar Salvador static void __prep_account_new_huge_page(struct hstate *h, int nid) 1925d3d99fccSOscar Salvador { 1926d3d99fccSOscar Salvador lockdep_assert_held(&hugetlb_lock); 1927d3d99fccSOscar Salvador h->nr_huge_pages++; 1928d3d99fccSOscar Salvador h->nr_huge_pages_node[nid]++; 1929d3d99fccSOscar Salvador } 1930d3d99fccSOscar Salvador 1931de656ed3SSidhartha Kumar static void __prep_new_hugetlb_folio(struct hstate *h, struct folio *folio) 1932b7ba30c6SAndi Kleen { 1933de656ed3SSidhartha Kumar hugetlb_vmemmap_optimize(h, &folio->page); 1934de656ed3SSidhartha Kumar INIT_LIST_HEAD(&folio->lru); 19359fd33058SSidhartha Kumar folio_set_compound_dtor(folio, HUGETLB_PAGE_DTOR); 1936de656ed3SSidhartha Kumar hugetlb_set_folio_subpool(folio, NULL); 1937de656ed3SSidhartha Kumar set_hugetlb_cgroup(folio, NULL); 1938de656ed3SSidhartha Kumar set_hugetlb_cgroup_rsvd(folio, NULL); 1939d3d99fccSOscar Salvador } 1940d3d99fccSOscar Salvador 1941d1c60955SSidhartha Kumar static void prep_new_hugetlb_folio(struct hstate *h, struct folio *folio, int nid) 1942d3d99fccSOscar Salvador { 1943de656ed3SSidhartha Kumar __prep_new_hugetlb_folio(h, folio); 1944db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 1945d3d99fccSOscar Salvador __prep_account_new_huge_page(h, nid); 1946db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1947b7ba30c6SAndi Kleen } 1948b7ba30c6SAndi Kleen 1949d1c60955SSidhartha Kumar static bool __prep_compound_gigantic_folio(struct folio *folio, 1950d1c60955SSidhartha Kumar unsigned int order, bool demote) 195120a0307cSWu Fengguang { 19527118fc29SMike Kravetz int i, j; 195320a0307cSWu Fengguang int nr_pages = 1 << order; 195414455eabSCheng Li struct page *p; 195520a0307cSWu Fengguang 1956d1c60955SSidhartha Kumar __folio_clear_reserved(folio); 1957d1c60955SSidhartha Kumar __folio_set_head(folio); 1958c45bc55aSSidhartha Kumar /* we rely on prep_new_hugetlb_folio to set the destructor */ 1959c45bc55aSSidhartha Kumar folio_set_compound_order(folio, order); 19602b21624fSMike Kravetz for (i = 0; i < nr_pages; i++) { 1961d1c60955SSidhartha Kumar p = folio_page(folio, i); 196214455eabSCheng Li 1963ef5a22beSAndrea Arcangeli /* 1964ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1965ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1966ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 19677c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1968ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1969ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1970ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1971ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1972ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1973ef5a22beSAndrea Arcangeli * after get_user_pages(). 1974ef5a22beSAndrea Arcangeli */ 19757fb0728aSMike Kravetz if (i != 0) /* head page cleared above */ 1976ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 19777118fc29SMike Kravetz /* 19787118fc29SMike Kravetz * Subtle and very unlikely 19797118fc29SMike Kravetz * 19807118fc29SMike Kravetz * Gigantic 'page allocators' such as memblock or cma will 19817118fc29SMike Kravetz * return a set of pages with each page ref counted. We need 19827118fc29SMike Kravetz * to turn this set of pages into a compound page with tail 19837118fc29SMike Kravetz * page ref counts set to zero. Code such as speculative page 19847118fc29SMike Kravetz * cache adding could take a ref on a 'to be' tail page. 19857118fc29SMike Kravetz * We need to respect any increased ref count, and only set 19867118fc29SMike Kravetz * the ref count to zero if count is currently 1. If count 1987416d85edSMike Kravetz * is not 1, we return an error. An error return indicates 1988416d85edSMike Kravetz * the set of pages can not be converted to a gigantic page. 1989416d85edSMike Kravetz * The caller who allocated the pages should then discard the 1990416d85edSMike Kravetz * pages using the appropriate free interface. 199134d9e35bSMike Kravetz * 199234d9e35bSMike Kravetz * In the case of demote, the ref count will be zero. 19937118fc29SMike Kravetz */ 199434d9e35bSMike Kravetz if (!demote) { 19957118fc29SMike Kravetz if (!page_ref_freeze(p, 1)) { 1996416d85edSMike Kravetz pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n"); 19977118fc29SMike Kravetz goto out_error; 19987118fc29SMike Kravetz } 199934d9e35bSMike Kravetz } else { 200034d9e35bSMike Kravetz VM_BUG_ON_PAGE(page_count(p), p); 200134d9e35bSMike Kravetz } 20022b21624fSMike Kravetz if (i != 0) 2003d1c60955SSidhartha Kumar set_compound_head(p, &folio->page); 200420a0307cSWu Fengguang } 2005d1c60955SSidhartha Kumar atomic_set(folio_mapcount_ptr(folio), -1); 2006d1c60955SSidhartha Kumar atomic_set(folio_subpages_mapcount_ptr(folio), 0); 2007d1c60955SSidhartha Kumar atomic_set(folio_pincount_ptr(folio), 0); 20087118fc29SMike Kravetz return true; 20097118fc29SMike Kravetz 20107118fc29SMike Kravetz out_error: 20112b21624fSMike Kravetz /* undo page modifications made above */ 20122b21624fSMike Kravetz for (j = 0; j < i; j++) { 2013d1c60955SSidhartha Kumar p = folio_page(folio, j); 20142b21624fSMike Kravetz if (j != 0) 20157118fc29SMike Kravetz clear_compound_head(p); 20167118fc29SMike Kravetz set_page_refcounted(p); 20177118fc29SMike Kravetz } 20187118fc29SMike Kravetz /* need to clear PG_reserved on remaining tail pages */ 201914455eabSCheng Li for (; j < nr_pages; j++) { 2020d1c60955SSidhartha Kumar p = folio_page(folio, j); 20217118fc29SMike Kravetz __ClearPageReserved(p); 202214455eabSCheng Li } 2023d1c60955SSidhartha Kumar folio_set_compound_order(folio, 0); 2024d1c60955SSidhartha Kumar __folio_clear_head(folio); 20257118fc29SMike Kravetz return false; 202620a0307cSWu Fengguang } 202720a0307cSWu Fengguang 2028d1c60955SSidhartha Kumar static bool prep_compound_gigantic_folio(struct folio *folio, 20298531fc6fSMike Kravetz unsigned int order) 20308531fc6fSMike Kravetz { 2031d1c60955SSidhartha Kumar return __prep_compound_gigantic_folio(folio, order, false); 2032d1c60955SSidhartha Kumar } 2033d1c60955SSidhartha Kumar 2034d1c60955SSidhartha Kumar static bool prep_compound_gigantic_folio_for_demote(struct folio *folio, 2035d1c60955SSidhartha Kumar unsigned int order) 2036d1c60955SSidhartha Kumar { 2037d1c60955SSidhartha Kumar return __prep_compound_gigantic_folio(folio, order, true); 20388531fc6fSMike Kravetz } 20398531fc6fSMike Kravetz 20407795912cSAndrew Morton /* 20417795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 20427795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 20437795912cSAndrew Morton * details. 20447795912cSAndrew Morton */ 204520a0307cSWu Fengguang int PageHuge(struct page *page) 204620a0307cSWu Fengguang { 204720a0307cSWu Fengguang if (!PageCompound(page)) 204820a0307cSWu Fengguang return 0; 204920a0307cSWu Fengguang 205020a0307cSWu Fengguang page = compound_head(page); 2051f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 205220a0307cSWu Fengguang } 205343131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 205443131e14SNaoya Horiguchi 205527c73ae7SAndrea Arcangeli /* 205627c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 205727c73ae7SAndrea Arcangeli * normal or transparent huge pages. 205827c73ae7SAndrea Arcangeli */ 205927c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 206027c73ae7SAndrea Arcangeli { 206127c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 206227c73ae7SAndrea Arcangeli return 0; 206327c73ae7SAndrea Arcangeli 2064d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 206527c73ae7SAndrea Arcangeli } 20664e936eccSDavid Howells EXPORT_SYMBOL_GPL(PageHeadHuge); 206727c73ae7SAndrea Arcangeli 2068c0d0381aSMike Kravetz /* 2069c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 2070c0d0381aSMike Kravetz * 2071336bf30eSMike Kravetz * Upon entry, the page is locked which means that page_mapping() is 2072336bf30eSMike Kravetz * stable. Due to locking order, we can only trylock_write. If we can 2073336bf30eSMike Kravetz * not get the lock, simply return NULL to caller. 2074c0d0381aSMike Kravetz */ 2075c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 2076c0d0381aSMike Kravetz { 2077336bf30eSMike Kravetz struct address_space *mapping = page_mapping(hpage); 2078c0d0381aSMike Kravetz 2079c0d0381aSMike Kravetz if (!mapping) 2080c0d0381aSMike Kravetz return mapping; 2081c0d0381aSMike Kravetz 2082c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 2083c0d0381aSMike Kravetz return mapping; 2084c0d0381aSMike Kravetz 2085c0d0381aSMike Kravetz return NULL; 2086c0d0381aSMike Kravetz } 2087c0d0381aSMike Kravetz 2088fe19bd3dSHugh Dickins pgoff_t hugetlb_basepage_index(struct page *page) 208913d60f4bSZhang Yi { 209013d60f4bSZhang Yi struct page *page_head = compound_head(page); 209113d60f4bSZhang Yi pgoff_t index = page_index(page_head); 209213d60f4bSZhang Yi unsigned long compound_idx; 209313d60f4bSZhang Yi 209413d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 209513d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 209613d60f4bSZhang Yi else 209713d60f4bSZhang Yi compound_idx = page - page_head; 209813d60f4bSZhang Yi 209913d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 210013d60f4bSZhang Yi } 210113d60f4bSZhang Yi 210219fc1a7eSSidhartha Kumar static struct folio *alloc_buddy_hugetlb_folio(struct hstate *h, 2103f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 2104f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 21051da177e4SLinus Torvalds { 2106af0fb9dfSMichal Hocko int order = huge_page_order(h); 21071da177e4SLinus Torvalds struct page *page; 2108f60858f9SMike Kravetz bool alloc_try_hard = true; 21092b21624fSMike Kravetz bool retry = true; 2110f96efd58SJoe Jin 2111f60858f9SMike Kravetz /* 2112f60858f9SMike Kravetz * By default we always try hard to allocate the page with 2113f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 2114f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 2115f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 2116f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 2117f60858f9SMike Kravetz */ 2118f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 2119f60858f9SMike Kravetz alloc_try_hard = false; 2120f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 2121f60858f9SMike Kravetz if (alloc_try_hard) 2122f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 2123af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 2124af0fb9dfSMichal Hocko nid = numa_mem_id(); 21252b21624fSMike Kravetz retry: 212684172f4bSMatthew Wilcox (Oracle) page = __alloc_pages(gfp_mask, order, nid, nmask); 21272b21624fSMike Kravetz 21282b21624fSMike Kravetz /* Freeze head page */ 21292b21624fSMike Kravetz if (page && !page_ref_freeze(page, 1)) { 21302b21624fSMike Kravetz __free_pages(page, order); 21312b21624fSMike Kravetz if (retry) { /* retry once */ 21322b21624fSMike Kravetz retry = false; 21332b21624fSMike Kravetz goto retry; 21342b21624fSMike Kravetz } 21352b21624fSMike Kravetz /* WOW! twice in a row. */ 21362b21624fSMike Kravetz pr_warn("HugeTLB head page unexpected inflated ref count\n"); 21372b21624fSMike Kravetz page = NULL; 21382b21624fSMike Kravetz } 21392b21624fSMike Kravetz 2140f60858f9SMike Kravetz /* 2141f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 2142f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 2143f60858f9SMike Kravetz * normal 'try hard' allocations. 2144f60858f9SMike Kravetz */ 2145f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 2146f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 2147f60858f9SMike Kravetz 2148f60858f9SMike Kravetz /* 2149f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 2150f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 2151f60858f9SMike Kravetz * overall state change. 2152f60858f9SMike Kravetz */ 2153f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 2154f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 2155f60858f9SMike Kravetz 215619fc1a7eSSidhartha Kumar if (!page) { 215719fc1a7eSSidhartha Kumar __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 215819fc1a7eSSidhartha Kumar return NULL; 215919fc1a7eSSidhartha Kumar } 216019fc1a7eSSidhartha Kumar 216119fc1a7eSSidhartha Kumar __count_vm_event(HTLB_BUDDY_PGALLOC); 216219fc1a7eSSidhartha Kumar return page_folio(page); 216363b4613cSNishanth Aravamudan } 216463b4613cSNishanth Aravamudan 2165af0fb9dfSMichal Hocko /* 21660c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 21670c397daeSMichal Hocko * should use this function to get new hugetlb pages 21682b21624fSMike Kravetz * 21692b21624fSMike Kravetz * Note that returned page is 'frozen': ref count of head page and all tail 21702b21624fSMike Kravetz * pages is zero. 21710c397daeSMichal Hocko */ 217219fc1a7eSSidhartha Kumar static struct folio *alloc_fresh_hugetlb_folio(struct hstate *h, 2173f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 2174f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 21750c397daeSMichal Hocko { 21767f325a8dSSidhartha Kumar struct folio *folio; 21777118fc29SMike Kravetz bool retry = false; 21780c397daeSMichal Hocko 21797118fc29SMike Kravetz retry: 21800c397daeSMichal Hocko if (hstate_is_gigantic(h)) 218119fc1a7eSSidhartha Kumar folio = alloc_gigantic_folio(h, gfp_mask, nid, nmask); 21820c397daeSMichal Hocko else 218319fc1a7eSSidhartha Kumar folio = alloc_buddy_hugetlb_folio(h, gfp_mask, 2184f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 218519fc1a7eSSidhartha Kumar if (!folio) 21860c397daeSMichal Hocko return NULL; 21877118fc29SMike Kravetz if (hstate_is_gigantic(h)) { 2188d1c60955SSidhartha Kumar if (!prep_compound_gigantic_folio(folio, huge_page_order(h))) { 21897118fc29SMike Kravetz /* 21907118fc29SMike Kravetz * Rare failure to convert pages to compound page. 21917118fc29SMike Kravetz * Free pages and try again - ONCE! 21927118fc29SMike Kravetz */ 21937f325a8dSSidhartha Kumar free_gigantic_folio(folio, huge_page_order(h)); 21947118fc29SMike Kravetz if (!retry) { 21957118fc29SMike Kravetz retry = true; 21967118fc29SMike Kravetz goto retry; 21977118fc29SMike Kravetz } 21987118fc29SMike Kravetz return NULL; 21997118fc29SMike Kravetz } 22007118fc29SMike Kravetz } 2201d1c60955SSidhartha Kumar prep_new_hugetlb_folio(h, folio, folio_nid(folio)); 22020c397daeSMichal Hocko 220319fc1a7eSSidhartha Kumar return folio; 22040c397daeSMichal Hocko } 22050c397daeSMichal Hocko 22060c397daeSMichal Hocko /* 2207af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 2208af0fb9dfSMichal Hocko * manner. 2209af0fb9dfSMichal Hocko */ 2210f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 2211f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 2212b2261026SJoonsoo Kim { 221319fc1a7eSSidhartha Kumar struct folio *folio; 2214b2261026SJoonsoo Kim int nr_nodes, node; 2215af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2216b2261026SJoonsoo Kim 2217b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 221819fc1a7eSSidhartha Kumar folio = alloc_fresh_hugetlb_folio(h, gfp_mask, node, 221919fc1a7eSSidhartha Kumar nodes_allowed, node_alloc_noretry); 222019fc1a7eSSidhartha Kumar if (folio) { 222119fc1a7eSSidhartha Kumar free_huge_page(&folio->page); /* free it into the hugepage allocator */ 222219fc1a7eSSidhartha Kumar return 1; 222319fc1a7eSSidhartha Kumar } 2224b2261026SJoonsoo Kim } 2225b2261026SJoonsoo Kim 2226af0fb9dfSMichal Hocko return 0; 2227b2261026SJoonsoo Kim } 2228b2261026SJoonsoo Kim 2229e8c5c824SLee Schermerhorn /* 223010c6ec49SMike Kravetz * Remove huge page from pool from next node to free. Attempt to keep 223110c6ec49SMike Kravetz * persistent huge pages more or less balanced over allowed nodes. 223210c6ec49SMike Kravetz * This routine only 'removes' the hugetlb page. The caller must make 223310c6ec49SMike Kravetz * an additional call to free the page to low level allocators. 2234e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 2235e8c5c824SLee Schermerhorn */ 223610c6ec49SMike Kravetz static struct page *remove_pool_huge_page(struct hstate *h, 223710c6ec49SMike Kravetz nodemask_t *nodes_allowed, 22386ae11b27SLee Schermerhorn bool acct_surplus) 2239e8c5c824SLee Schermerhorn { 2240b2261026SJoonsoo Kim int nr_nodes, node; 224110c6ec49SMike Kravetz struct page *page = NULL; 2242cfd5082bSSidhartha Kumar struct folio *folio; 2243e8c5c824SLee Schermerhorn 22449487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2245b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2246685f3457SLee Schermerhorn /* 2247685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 2248685f3457SLee Schermerhorn * nodes with surplus pages. 2249685f3457SLee Schermerhorn */ 2250b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 2251b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 225210c6ec49SMike Kravetz page = list_entry(h->hugepage_freelists[node].next, 2253e8c5c824SLee Schermerhorn struct page, lru); 2254cfd5082bSSidhartha Kumar folio = page_folio(page); 2255cfd5082bSSidhartha Kumar remove_hugetlb_folio(h, folio, acct_surplus); 22569a76db09SLee Schermerhorn break; 2257e8c5c824SLee Schermerhorn } 2258b2261026SJoonsoo Kim } 2259e8c5c824SLee Schermerhorn 226010c6ec49SMike Kravetz return page; 2261e8c5c824SLee Schermerhorn } 2262e8c5c824SLee Schermerhorn 2263c8721bbbSNaoya Horiguchi /* 2264c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 2265faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 2266faf53defSNaoya Horiguchi * This function returns values like below: 2267faf53defSNaoya Horiguchi * 2268ad2fa371SMuchun Song * -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages 2269ad2fa371SMuchun Song * when the system is under memory pressure and the feature of 2270ad2fa371SMuchun Song * freeing unused vmemmap pages associated with each hugetlb page 2271ad2fa371SMuchun Song * is enabled. 2272faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 2273faf53defSNaoya Horiguchi * (allocated or reserved.) 2274faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 2275faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 2276c8721bbbSNaoya Horiguchi */ 2277c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 2278c8721bbbSNaoya Horiguchi { 22796bc9b564SNaoya Horiguchi int rc = -EBUSY; 22801a7cdab5SSidhartha Kumar struct folio *folio = page_folio(page); 2281082d5b6bSGerald Schaefer 22827ffddd49SMuchun Song retry: 2283faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 22841a7cdab5SSidhartha Kumar if (!folio_test_hugetlb(folio)) 2285faf53defSNaoya Horiguchi return 0; 2286faf53defSNaoya Horiguchi 2287db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 22881a7cdab5SSidhartha Kumar if (!folio_test_hugetlb(folio)) { 2289faf53defSNaoya Horiguchi rc = 0; 2290faf53defSNaoya Horiguchi goto out; 2291faf53defSNaoya Horiguchi } 2292faf53defSNaoya Horiguchi 22931a7cdab5SSidhartha Kumar if (!folio_ref_count(folio)) { 22941a7cdab5SSidhartha Kumar struct hstate *h = folio_hstate(folio); 22958346d69dSXin Hao if (!available_huge_pages(h)) 2296082d5b6bSGerald Schaefer goto out; 22977ffddd49SMuchun Song 22987ffddd49SMuchun Song /* 22997ffddd49SMuchun Song * We should make sure that the page is already on the free list 23007ffddd49SMuchun Song * when it is dissolved. 23017ffddd49SMuchun Song */ 23021a7cdab5SSidhartha Kumar if (unlikely(!folio_test_hugetlb_freed(folio))) { 2303db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23047ffddd49SMuchun Song cond_resched(); 23057ffddd49SMuchun Song 23067ffddd49SMuchun Song /* 23077ffddd49SMuchun Song * Theoretically, we should return -EBUSY when we 23087ffddd49SMuchun Song * encounter this race. In fact, we have a chance 23097ffddd49SMuchun Song * to successfully dissolve the page if we do a 23107ffddd49SMuchun Song * retry. Because the race window is quite small. 23117ffddd49SMuchun Song * If we seize this opportunity, it is an optimization 23127ffddd49SMuchun Song * for increasing the success rate of dissolving page. 23137ffddd49SMuchun Song */ 23147ffddd49SMuchun Song goto retry; 23157ffddd49SMuchun Song } 23167ffddd49SMuchun Song 2317cfd5082bSSidhartha Kumar remove_hugetlb_folio(h, folio, false); 2318ad2fa371SMuchun Song h->max_huge_pages--; 2319ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2320ad2fa371SMuchun Song 2321c3114a84SAnshuman Khandual /* 2322d6ef19e2SSidhartha Kumar * Normally update_and_free_hugtlb_folio will allocate required vmemmmap 2323d6ef19e2SSidhartha Kumar * before freeing the page. update_and_free_hugtlb_folio will fail to 2324ad2fa371SMuchun Song * free the page if it can not allocate required vmemmap. We 2325ad2fa371SMuchun Song * need to adjust max_huge_pages if the page is not freed. 2326ad2fa371SMuchun Song * Attempt to allocate vmemmmap here so that we can take 2327ad2fa371SMuchun Song * appropriate action on failure. 2328ad2fa371SMuchun Song */ 23291a7cdab5SSidhartha Kumar rc = hugetlb_vmemmap_restore(h, &folio->page); 2330ad2fa371SMuchun Song if (!rc) { 2331d6ef19e2SSidhartha Kumar update_and_free_hugetlb_folio(h, folio, false); 2332ad2fa371SMuchun Song } else { 2333ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 23342f6c57d6SSidhartha Kumar add_hugetlb_folio(h, folio, false); 2335ad2fa371SMuchun Song h->max_huge_pages++; 2336ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2337ad2fa371SMuchun Song } 2338ad2fa371SMuchun Song 2339ad2fa371SMuchun Song return rc; 2340c8721bbbSNaoya Horiguchi } 2341082d5b6bSGerald Schaefer out: 2342db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2343082d5b6bSGerald Schaefer return rc; 2344c8721bbbSNaoya Horiguchi } 2345c8721bbbSNaoya Horiguchi 2346c8721bbbSNaoya Horiguchi /* 2347c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 2348c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 23492247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 23502247bb33SGerald Schaefer * part of it lies within the given range. 2351082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 2352082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 2353c8721bbbSNaoya Horiguchi */ 2354082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 2355c8721bbbSNaoya Horiguchi { 2356c8721bbbSNaoya Horiguchi unsigned long pfn; 2357eb03aa00SGerald Schaefer struct page *page; 2358082d5b6bSGerald Schaefer int rc = 0; 2359dc2628f3SMuchun Song unsigned int order; 2360dc2628f3SMuchun Song struct hstate *h; 2361c8721bbbSNaoya Horiguchi 2362d0177639SLi Zhong if (!hugepages_supported()) 2363082d5b6bSGerald Schaefer return rc; 2364d0177639SLi Zhong 2365dc2628f3SMuchun Song order = huge_page_order(&default_hstate); 2366dc2628f3SMuchun Song for_each_hstate(h) 2367dc2628f3SMuchun Song order = min(order, huge_page_order(h)); 2368dc2628f3SMuchun Song 2369dc2628f3SMuchun Song for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) { 2370eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 2371eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 2372eb03aa00SGerald Schaefer if (rc) 2373082d5b6bSGerald Schaefer break; 2374eb03aa00SGerald Schaefer } 2375082d5b6bSGerald Schaefer 2376082d5b6bSGerald Schaefer return rc; 2377c8721bbbSNaoya Horiguchi } 2378c8721bbbSNaoya Horiguchi 2379ab5ac90aSMichal Hocko /* 2380ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 2381ab5ac90aSMichal Hocko */ 23820c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 23832b21624fSMike Kravetz int nid, nodemask_t *nmask) 23847893d1d5SAdam Litke { 238519fc1a7eSSidhartha Kumar struct folio *folio = NULL; 23867893d1d5SAdam Litke 2387bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2388aa888a74SAndi Kleen return NULL; 2389aa888a74SAndi Kleen 2390db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 23919980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 23929980d744SMichal Hocko goto out_unlock; 2393db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2394d1c3fb1fSNishanth Aravamudan 239519fc1a7eSSidhartha Kumar folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask, NULL); 239619fc1a7eSSidhartha Kumar if (!folio) 23970c397daeSMichal Hocko return NULL; 2398d1c3fb1fSNishanth Aravamudan 2399db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 24009980d744SMichal Hocko /* 24019980d744SMichal Hocko * We could have raced with the pool size change. 24029980d744SMichal Hocko * Double check that and simply deallocate the new page 24039980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 24049980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 24059980d744SMichal Hocko * codeflow 24069980d744SMichal Hocko */ 24079980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 240819fc1a7eSSidhartha Kumar folio_set_hugetlb_temporary(folio); 2409db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 241019fc1a7eSSidhartha Kumar free_huge_page(&folio->page); 24112bf753e6SKai Shen return NULL; 2412b65a4edaSMike Kravetz } 2413b65a4edaSMike Kravetz 24149980d744SMichal Hocko h->surplus_huge_pages++; 241519fc1a7eSSidhartha Kumar h->surplus_huge_pages_node[folio_nid(folio)]++; 24169980d744SMichal Hocko 24179980d744SMichal Hocko out_unlock: 2418db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 24197893d1d5SAdam Litke 242019fc1a7eSSidhartha Kumar return &folio->page; 24217893d1d5SAdam Litke } 24227893d1d5SAdam Litke 2423bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 2424ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 2425ab5ac90aSMichal Hocko { 242619fc1a7eSSidhartha Kumar struct folio *folio; 2427ab5ac90aSMichal Hocko 2428ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 2429ab5ac90aSMichal Hocko return NULL; 2430ab5ac90aSMichal Hocko 243119fc1a7eSSidhartha Kumar folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask, NULL); 243219fc1a7eSSidhartha Kumar if (!folio) 2433ab5ac90aSMichal Hocko return NULL; 2434ab5ac90aSMichal Hocko 24352b21624fSMike Kravetz /* fresh huge pages are frozen */ 243619fc1a7eSSidhartha Kumar folio_ref_unfreeze(folio, 1); 2437ab5ac90aSMichal Hocko /* 2438ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 2439ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 2440ab5ac90aSMichal Hocko */ 244119fc1a7eSSidhartha Kumar folio_set_hugetlb_temporary(folio); 2442ab5ac90aSMichal Hocko 244319fc1a7eSSidhartha Kumar return &folio->page; 2444ab5ac90aSMichal Hocko } 2445ab5ac90aSMichal Hocko 2446e4e574b7SAdam Litke /* 2447099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 2448099730d6SDave Hansen */ 2449e0ec90eeSDave Hansen static 24500c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 2451099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 2452099730d6SDave Hansen { 2453cfcaa66fSBen Widawsky struct page *page = NULL; 2454aaf14e40SMichal Hocko struct mempolicy *mpol; 2455aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 2456aaf14e40SMichal Hocko int nid; 2457aaf14e40SMichal Hocko nodemask_t *nodemask; 2458aaf14e40SMichal Hocko 2459aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 2460cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 2461cfcaa66fSBen Widawsky gfp_t gfp = gfp_mask | __GFP_NOWARN; 2462cfcaa66fSBen Widawsky 2463cfcaa66fSBen Widawsky gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); 24642b21624fSMike Kravetz page = alloc_surplus_huge_page(h, gfp, nid, nodemask); 2465cfcaa66fSBen Widawsky 2466cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 2467cfcaa66fSBen Widawsky nodemask = NULL; 2468cfcaa66fSBen Widawsky } 2469cfcaa66fSBen Widawsky 2470cfcaa66fSBen Widawsky if (!page) 24712b21624fSMike Kravetz page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask); 2472aaf14e40SMichal Hocko mpol_cond_put(mpol); 2473aaf14e40SMichal Hocko return page; 2474099730d6SDave Hansen } 2475099730d6SDave Hansen 2476ab5ac90aSMichal Hocko /* page migration callback function */ 24773e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 2478d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 24794db9b2efSMichal Hocko { 2480db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 24818346d69dSXin Hao if (available_huge_pages(h)) { 24823e59fcb0SMichal Hocko struct page *page; 24833e59fcb0SMichal Hocko 24843e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 24853e59fcb0SMichal Hocko if (page) { 2486db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 24873e59fcb0SMichal Hocko return page; 24884db9b2efSMichal Hocko } 24894db9b2efSMichal Hocko } 2490db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 24914db9b2efSMichal Hocko 24920c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 24934db9b2efSMichal Hocko } 24944db9b2efSMichal Hocko 2495ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2496389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2497389c8178SMichal Hocko unsigned long address) 2498ebd63723SMichal Hocko { 2499ebd63723SMichal Hocko struct mempolicy *mpol; 2500ebd63723SMichal Hocko nodemask_t *nodemask; 2501ebd63723SMichal Hocko struct page *page; 2502ebd63723SMichal Hocko gfp_t gfp_mask; 2503ebd63723SMichal Hocko int node; 2504ebd63723SMichal Hocko 2505ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2506ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2507d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2508ebd63723SMichal Hocko mpol_cond_put(mpol); 2509ebd63723SMichal Hocko 2510ebd63723SMichal Hocko return page; 2511ebd63723SMichal Hocko } 2512ebd63723SMichal Hocko 2513bf50bab2SNaoya Horiguchi /* 251425985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2515e4e574b7SAdam Litke * of size 'delta'. 2516e4e574b7SAdam Litke */ 25170a4f3d1bSLiu Xiang static int gather_surplus_pages(struct hstate *h, long delta) 25181b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2519e4e574b7SAdam Litke { 252034665341SMiaohe Lin LIST_HEAD(surplus_list); 2521e4e574b7SAdam Litke struct page *page, *tmp; 25220a4f3d1bSLiu Xiang int ret; 25230a4f3d1bSLiu Xiang long i; 25240a4f3d1bSLiu Xiang long needed, allocated; 252528073b02SHillf Danton bool alloc_ok = true; 2526e4e574b7SAdam Litke 25279487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2528a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2529ac09b3a1SAdam Litke if (needed <= 0) { 2530a5516438SAndi Kleen h->resv_huge_pages += delta; 2531e4e574b7SAdam Litke return 0; 2532ac09b3a1SAdam Litke } 2533e4e574b7SAdam Litke 2534e4e574b7SAdam Litke allocated = 0; 2535e4e574b7SAdam Litke 2536e4e574b7SAdam Litke ret = -ENOMEM; 2537e4e574b7SAdam Litke retry: 2538db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2539e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 25400c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 25412b21624fSMike Kravetz NUMA_NO_NODE, NULL); 254228073b02SHillf Danton if (!page) { 254328073b02SHillf Danton alloc_ok = false; 254428073b02SHillf Danton break; 254528073b02SHillf Danton } 2546e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 254769ed779aSDavid Rientjes cond_resched(); 2548e4e574b7SAdam Litke } 254928073b02SHillf Danton allocated += i; 2550e4e574b7SAdam Litke 2551e4e574b7SAdam Litke /* 2552e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2553e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2554e4e574b7SAdam Litke */ 2555db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2556a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2557a5516438SAndi Kleen (h->free_huge_pages + allocated); 255828073b02SHillf Danton if (needed > 0) { 255928073b02SHillf Danton if (alloc_ok) 2560e4e574b7SAdam Litke goto retry; 256128073b02SHillf Danton /* 256228073b02SHillf Danton * We were not able to allocate enough pages to 256328073b02SHillf Danton * satisfy the entire reservation so we free what 256428073b02SHillf Danton * we've allocated so far. 256528073b02SHillf Danton */ 256628073b02SHillf Danton goto free; 256728073b02SHillf Danton } 2568e4e574b7SAdam Litke /* 2569e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 257025985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2571e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2572ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2573ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2574ac09b3a1SAdam Litke * before they are reserved. 2575e4e574b7SAdam Litke */ 2576e4e574b7SAdam Litke needed += allocated; 2577a5516438SAndi Kleen h->resv_huge_pages += delta; 2578e4e574b7SAdam Litke ret = 0; 2579a9869b83SNaoya Horiguchi 258019fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 258119fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 258219fc3f0aSAdam Litke if ((--needed) < 0) 258319fc3f0aSAdam Litke break; 2584b65a4edaSMike Kravetz /* Add the page to the hugetlb allocator */ 2585240d67a8SSidhartha Kumar enqueue_hugetlb_folio(h, page_folio(page)); 258619fc3f0aSAdam Litke } 258728073b02SHillf Danton free: 2588db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 258919fc3f0aSAdam Litke 2590b65a4edaSMike Kravetz /* 2591b65a4edaSMike Kravetz * Free unnecessary surplus pages to the buddy allocator. 2592b65a4edaSMike Kravetz * Pages have no ref count, call free_huge_page directly. 2593b65a4edaSMike Kravetz */ 2594c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2595b65a4edaSMike Kravetz free_huge_page(page); 2596db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2597e4e574b7SAdam Litke 2598e4e574b7SAdam Litke return ret; 2599e4e574b7SAdam Litke } 2600e4e574b7SAdam Litke 2601e4e574b7SAdam Litke /* 2602e5bbc8a6SMike Kravetz * This routine has two main purposes: 2603e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2604e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2605e5bbc8a6SMike Kravetz * to the associated reservation map. 2606e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2607e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2608e4e574b7SAdam Litke */ 2609a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2610a5516438SAndi Kleen unsigned long unused_resv_pages) 2611e4e574b7SAdam Litke { 2612e4e574b7SAdam Litke unsigned long nr_pages; 261310c6ec49SMike Kravetz struct page *page; 261410c6ec49SMike Kravetz LIST_HEAD(page_list); 261510c6ec49SMike Kravetz 26169487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 261710c6ec49SMike Kravetz /* Uncommit the reservation */ 261810c6ec49SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2619e4e574b7SAdam Litke 2620c0531714SNaoya Horiguchi if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 2621e5bbc8a6SMike Kravetz goto out; 2622aa888a74SAndi Kleen 2623e5bbc8a6SMike Kravetz /* 2624e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2625e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2626e5bbc8a6SMike Kravetz */ 2627a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2628e4e574b7SAdam Litke 2629685f3457SLee Schermerhorn /* 2630685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 26319b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 26329b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 26339b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 263410c6ec49SMike Kravetz * remove_pool_huge_page() will balance the freed pages across the 26359b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2636685f3457SLee Schermerhorn */ 2637685f3457SLee Schermerhorn while (nr_pages--) { 263810c6ec49SMike Kravetz page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); 263910c6ec49SMike Kravetz if (!page) 2640e5bbc8a6SMike Kravetz goto out; 264110c6ec49SMike Kravetz 264210c6ec49SMike Kravetz list_add(&page->lru, &page_list); 2643e4e574b7SAdam Litke } 2644e5bbc8a6SMike Kravetz 2645e5bbc8a6SMike Kravetz out: 2646db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 264710c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 2648db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2649e4e574b7SAdam Litke } 2650e4e574b7SAdam Litke 26515e911373SMike Kravetz 2652c37f9fb1SAndy Whitcroft /* 2653feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 26545e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2655cf3ad20bSMike Kravetz * 2656cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2657cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2658cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2659cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2660cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2661feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2662feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2663feba16e2SMike Kravetz * is called in such cases. 2664cf3ad20bSMike Kravetz * 2665cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2666cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2667cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2668cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2669cf3ad20bSMike Kravetz * take appropriate action. 267096b96a96SMike Kravetz * 267196b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 267296b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 267396b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 267496b96a96SMike Kravetz * reservation exists. 2675846be085SMike Kravetz * 2676846be085SMike Kravetz * vma_del_reservation is used in error paths where an entry in the reserve 2677846be085SMike Kravetz * map was created during huge page allocation and must be removed. It is to 2678846be085SMike Kravetz * be called after calling vma_needs_reservation to determine if a reservation 2679846be085SMike Kravetz * exists. 2680c37f9fb1SAndy Whitcroft */ 26815e911373SMike Kravetz enum vma_resv_mode { 26825e911373SMike Kravetz VMA_NEEDS_RESV, 26835e911373SMike Kravetz VMA_COMMIT_RESV, 2684feba16e2SMike Kravetz VMA_END_RESV, 268596b96a96SMike Kravetz VMA_ADD_RESV, 2686846be085SMike Kravetz VMA_DEL_RESV, 26875e911373SMike Kravetz }; 2688cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2689cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 26905e911373SMike Kravetz enum vma_resv_mode mode) 2691c37f9fb1SAndy Whitcroft { 26924e35f483SJoonsoo Kim struct resv_map *resv; 26934e35f483SJoonsoo Kim pgoff_t idx; 2694cf3ad20bSMike Kravetz long ret; 26950db9d74eSMina Almasry long dummy_out_regions_needed; 2696c37f9fb1SAndy Whitcroft 26974e35f483SJoonsoo Kim resv = vma_resv_map(vma); 26984e35f483SJoonsoo Kim if (!resv) 2699c37f9fb1SAndy Whitcroft return 1; 2700c37f9fb1SAndy Whitcroft 27014e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 27025e911373SMike Kravetz switch (mode) { 27035e911373SMike Kravetz case VMA_NEEDS_RESV: 27040db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 27050db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 27060db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 27070db9d74eSMina Almasry * ever require 1 region. 27080db9d74eSMina Almasry */ 27090db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 27105e911373SMike Kravetz break; 27115e911373SMike Kravetz case VMA_COMMIT_RESV: 2712075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 27130db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 27140db9d74eSMina Almasry VM_BUG_ON(ret < 0); 27155e911373SMike Kravetz break; 2716feba16e2SMike Kravetz case VMA_END_RESV: 27170db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 27185e911373SMike Kravetz ret = 0; 27195e911373SMike Kravetz break; 272096b96a96SMike Kravetz case VMA_ADD_RESV: 27210db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2722075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 27230db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 27240db9d74eSMina Almasry VM_BUG_ON(ret < 0); 27250db9d74eSMina Almasry } else { 27260db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 272796b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 272896b96a96SMike Kravetz } 272996b96a96SMike Kravetz break; 2730846be085SMike Kravetz case VMA_DEL_RESV: 2731846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 2732846be085SMike Kravetz region_abort(resv, idx, idx + 1, 1); 2733846be085SMike Kravetz ret = region_del(resv, idx, idx + 1); 2734846be085SMike Kravetz } else { 2735846be085SMike Kravetz ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 2736846be085SMike Kravetz /* region_add calls of range 1 should never fail. */ 2737846be085SMike Kravetz VM_BUG_ON(ret < 0); 2738846be085SMike Kravetz } 2739846be085SMike Kravetz break; 27405e911373SMike Kravetz default: 27415e911373SMike Kravetz BUG(); 27425e911373SMike Kravetz } 274384afd99bSAndy Whitcroft 2744846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV) 2745cf3ad20bSMike Kravetz return ret; 274667961f9dSMike Kravetz /* 2747bf3d12b9SMiaohe Lin * We know private mapping must have HPAGE_RESV_OWNER set. 2748bf3d12b9SMiaohe Lin * 274967961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 275067961f9dSMike Kravetz * However, a file associated with mapping could have been 275167961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 275267961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 275367961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 275467961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 275567961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 275667961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 275767961f9dSMike Kravetz * reservation has already been consumed. As a result, the 275867961f9dSMike Kravetz * return value of this routine is the opposite of the 275967961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 276067961f9dSMike Kravetz */ 2761bf3d12b9SMiaohe Lin if (ret > 0) 276267961f9dSMike Kravetz return 0; 2763bf3d12b9SMiaohe Lin if (ret == 0) 276467961f9dSMike Kravetz return 1; 2765bf3d12b9SMiaohe Lin return ret; 276684afd99bSAndy Whitcroft } 2767cf3ad20bSMike Kravetz 2768cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2769a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2770c37f9fb1SAndy Whitcroft { 27715e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2772cf3ad20bSMike Kravetz } 2773c37f9fb1SAndy Whitcroft 2774cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2775cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2776cf3ad20bSMike Kravetz { 27775e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 27785e911373SMike Kravetz } 27795e911373SMike Kravetz 2780feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 27815e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 27825e911373SMike Kravetz { 2783feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2784c37f9fb1SAndy Whitcroft } 2785c37f9fb1SAndy Whitcroft 278696b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 278796b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 278896b96a96SMike Kravetz { 278996b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 279096b96a96SMike Kravetz } 279196b96a96SMike Kravetz 2792846be085SMike Kravetz static long vma_del_reservation(struct hstate *h, 2793846be085SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 279496b96a96SMike Kravetz { 2795846be085SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV); 2796846be085SMike Kravetz } 2797846be085SMike Kravetz 2798846be085SMike Kravetz /* 2799846be085SMike Kravetz * This routine is called to restore reservation information on error paths. 2800846be085SMike Kravetz * It should ONLY be called for pages allocated via alloc_huge_page(), and 2801846be085SMike Kravetz * the hugetlb mutex should remain held when calling this routine. 2802846be085SMike Kravetz * 2803846be085SMike Kravetz * It handles two specific cases: 2804846be085SMike Kravetz * 1) A reservation was in place and the page consumed the reservation. 2805846be085SMike Kravetz * HPageRestoreReserve is set in the page. 2806846be085SMike Kravetz * 2) No reservation was in place for the page, so HPageRestoreReserve is 2807846be085SMike Kravetz * not set. However, alloc_huge_page always updates the reserve map. 2808846be085SMike Kravetz * 2809846be085SMike Kravetz * In case 1, free_huge_page later in the error path will increment the 2810846be085SMike Kravetz * global reserve count. But, free_huge_page does not have enough context 2811846be085SMike Kravetz * to adjust the reservation map. This case deals primarily with private 2812846be085SMike Kravetz * mappings. Adjust the reserve map here to be consistent with global 2813846be085SMike Kravetz * reserve count adjustments to be made by free_huge_page. Make sure the 2814846be085SMike Kravetz * reserve map indicates there is a reservation present. 2815846be085SMike Kravetz * 2816846be085SMike Kravetz * In case 2, simply undo reserve map modifications done by alloc_huge_page. 2817846be085SMike Kravetz */ 2818846be085SMike Kravetz void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, 2819846be085SMike Kravetz unsigned long address, struct page *page) 2820846be085SMike Kravetz { 282196b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 282296b96a96SMike Kravetz 2823846be085SMike Kravetz if (HPageRestoreReserve(page)) { 2824846be085SMike Kravetz if (unlikely(rc < 0)) 282596b96a96SMike Kravetz /* 282696b96a96SMike Kravetz * Rare out of memory condition in reserve map 2827d6995da3SMike Kravetz * manipulation. Clear HPageRestoreReserve so that 282896b96a96SMike Kravetz * global reserve count will not be incremented 282996b96a96SMike Kravetz * by free_huge_page. This will make it appear 283096b96a96SMike Kravetz * as though the reservation for this page was 283196b96a96SMike Kravetz * consumed. This may prevent the task from 283296b96a96SMike Kravetz * faulting in the page at a later time. This 283396b96a96SMike Kravetz * is better than inconsistent global huge page 283496b96a96SMike Kravetz * accounting of reserve counts. 283596b96a96SMike Kravetz */ 2836d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 2837846be085SMike Kravetz else if (rc) 2838846be085SMike Kravetz (void)vma_add_reservation(h, vma, address); 2839846be085SMike Kravetz else 2840846be085SMike Kravetz vma_end_reservation(h, vma, address); 2841846be085SMike Kravetz } else { 2842846be085SMike Kravetz if (!rc) { 284396b96a96SMike Kravetz /* 2844846be085SMike Kravetz * This indicates there is an entry in the reserve map 2845c7b1850dSMike Kravetz * not added by alloc_huge_page. We know it was added 2846846be085SMike Kravetz * before the alloc_huge_page call, otherwise 2847846be085SMike Kravetz * HPageRestoreReserve would be set on the page. 2848846be085SMike Kravetz * Remove the entry so that a subsequent allocation 2849846be085SMike Kravetz * does not consume a reservation. 285096b96a96SMike Kravetz */ 2851846be085SMike Kravetz rc = vma_del_reservation(h, vma, address); 2852846be085SMike Kravetz if (rc < 0) 2853846be085SMike Kravetz /* 2854846be085SMike Kravetz * VERY rare out of memory condition. Since 2855846be085SMike Kravetz * we can not delete the entry, set 2856846be085SMike Kravetz * HPageRestoreReserve so that the reserve 2857846be085SMike Kravetz * count will be incremented when the page 2858846be085SMike Kravetz * is freed. This reserve will be consumed 2859846be085SMike Kravetz * on a subsequent allocation. 2860846be085SMike Kravetz */ 2861846be085SMike Kravetz SetHPageRestoreReserve(page); 2862846be085SMike Kravetz } else if (rc < 0) { 2863846be085SMike Kravetz /* 2864846be085SMike Kravetz * Rare out of memory condition from 2865846be085SMike Kravetz * vma_needs_reservation call. Memory allocation is 2866846be085SMike Kravetz * only attempted if a new entry is needed. Therefore, 2867846be085SMike Kravetz * this implies there is not an entry in the 2868846be085SMike Kravetz * reserve map. 2869846be085SMike Kravetz * 2870846be085SMike Kravetz * For shared mappings, no entry in the map indicates 2871846be085SMike Kravetz * no reservation. We are done. 2872846be085SMike Kravetz */ 2873846be085SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 2874846be085SMike Kravetz /* 2875846be085SMike Kravetz * For private mappings, no entry indicates 2876846be085SMike Kravetz * a reservation is present. Since we can 2877846be085SMike Kravetz * not add an entry, set SetHPageRestoreReserve 2878846be085SMike Kravetz * on the page so reserve count will be 2879846be085SMike Kravetz * incremented when freed. This reserve will 2880846be085SMike Kravetz * be consumed on a subsequent allocation. 2881846be085SMike Kravetz */ 2882846be085SMike Kravetz SetHPageRestoreReserve(page); 288396b96a96SMike Kravetz } else 2884846be085SMike Kravetz /* 2885846be085SMike Kravetz * No reservation present, do nothing 2886846be085SMike Kravetz */ 288796b96a96SMike Kravetz vma_end_reservation(h, vma, address); 288896b96a96SMike Kravetz } 288996b96a96SMike Kravetz } 289096b96a96SMike Kravetz 2891369fa227SOscar Salvador /* 289219fc1a7eSSidhartha Kumar * alloc_and_dissolve_hugetlb_folio - Allocate a new folio and dissolve 289319fc1a7eSSidhartha Kumar * the old one 2894369fa227SOscar Salvador * @h: struct hstate old page belongs to 289519fc1a7eSSidhartha Kumar * @old_folio: Old folio to dissolve 2896ae37c7ffSOscar Salvador * @list: List to isolate the page in case we need to 2897369fa227SOscar Salvador * Returns 0 on success, otherwise negated error. 2898369fa227SOscar Salvador */ 289919fc1a7eSSidhartha Kumar static int alloc_and_dissolve_hugetlb_folio(struct hstate *h, 290019fc1a7eSSidhartha Kumar struct folio *old_folio, struct list_head *list) 2901369fa227SOscar Salvador { 2902369fa227SOscar Salvador gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2903de656ed3SSidhartha Kumar int nid = folio_nid(old_folio); 2904de656ed3SSidhartha Kumar struct folio *new_folio; 2905369fa227SOscar Salvador int ret = 0; 2906369fa227SOscar Salvador 2907369fa227SOscar Salvador /* 290819fc1a7eSSidhartha Kumar * Before dissolving the folio, we need to allocate a new one for the 290919fc1a7eSSidhartha Kumar * pool to remain stable. Here, we allocate the folio and 'prep' it 2910f41f2ed4SMuchun Song * by doing everything but actually updating counters and adding to 2911f41f2ed4SMuchun Song * the pool. This simplifies and let us do most of the processing 2912f41f2ed4SMuchun Song * under the lock. 2913369fa227SOscar Salvador */ 291419fc1a7eSSidhartha Kumar new_folio = alloc_buddy_hugetlb_folio(h, gfp_mask, nid, NULL, NULL); 291519fc1a7eSSidhartha Kumar if (!new_folio) 2916369fa227SOscar Salvador return -ENOMEM; 2917de656ed3SSidhartha Kumar __prep_new_hugetlb_folio(h, new_folio); 2918369fa227SOscar Salvador 2919369fa227SOscar Salvador retry: 2920369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2921de656ed3SSidhartha Kumar if (!folio_test_hugetlb(old_folio)) { 2922369fa227SOscar Salvador /* 292319fc1a7eSSidhartha Kumar * Freed from under us. Drop new_folio too. 2924369fa227SOscar Salvador */ 2925369fa227SOscar Salvador goto free_new; 2926de656ed3SSidhartha Kumar } else if (folio_ref_count(old_folio)) { 2927369fa227SOscar Salvador /* 292819fc1a7eSSidhartha Kumar * Someone has grabbed the folio, try to isolate it here. 2929ae37c7ffSOscar Salvador * Fail with -EBUSY if not possible. 2930369fa227SOscar Salvador */ 2931ae37c7ffSOscar Salvador spin_unlock_irq(&hugetlb_lock); 293219fc1a7eSSidhartha Kumar ret = isolate_hugetlb(&old_folio->page, list); 2933ae37c7ffSOscar Salvador spin_lock_irq(&hugetlb_lock); 2934369fa227SOscar Salvador goto free_new; 2935de656ed3SSidhartha Kumar } else if (!folio_test_hugetlb_freed(old_folio)) { 2936369fa227SOscar Salvador /* 293719fc1a7eSSidhartha Kumar * Folio's refcount is 0 but it has not been enqueued in the 2938369fa227SOscar Salvador * freelist yet. Race window is small, so we can succeed here if 2939369fa227SOscar Salvador * we retry. 2940369fa227SOscar Salvador */ 2941369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2942369fa227SOscar Salvador cond_resched(); 2943369fa227SOscar Salvador goto retry; 2944369fa227SOscar Salvador } else { 2945369fa227SOscar Salvador /* 294619fc1a7eSSidhartha Kumar * Ok, old_folio is still a genuine free hugepage. Remove it from 2947369fa227SOscar Salvador * the freelist and decrease the counters. These will be 2948369fa227SOscar Salvador * incremented again when calling __prep_account_new_huge_page() 2949240d67a8SSidhartha Kumar * and enqueue_hugetlb_folio() for new_folio. The counters will 2950240d67a8SSidhartha Kumar * remain stable since this happens under the lock. 2951369fa227SOscar Salvador */ 2952cfd5082bSSidhartha Kumar remove_hugetlb_folio(h, old_folio, false); 2953369fa227SOscar Salvador 2954369fa227SOscar Salvador /* 295519fc1a7eSSidhartha Kumar * Ref count on new_folio is already zero as it was dropped 2956b65a4edaSMike Kravetz * earlier. It can be directly added to the pool free list. 2957369fa227SOscar Salvador */ 2958369fa227SOscar Salvador __prep_account_new_huge_page(h, nid); 2959240d67a8SSidhartha Kumar enqueue_hugetlb_folio(h, new_folio); 2960369fa227SOscar Salvador 2961369fa227SOscar Salvador /* 296219fc1a7eSSidhartha Kumar * Folio has been replaced, we can safely free the old one. 2963369fa227SOscar Salvador */ 2964369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2965d6ef19e2SSidhartha Kumar update_and_free_hugetlb_folio(h, old_folio, false); 2966369fa227SOscar Salvador } 2967369fa227SOscar Salvador 2968369fa227SOscar Salvador return ret; 2969369fa227SOscar Salvador 2970369fa227SOscar Salvador free_new: 2971369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 297219fc1a7eSSidhartha Kumar /* Folio has a zero ref count, but needs a ref to be freed */ 2973de656ed3SSidhartha Kumar folio_ref_unfreeze(new_folio, 1); 2974d6ef19e2SSidhartha Kumar update_and_free_hugetlb_folio(h, new_folio, false); 2975369fa227SOscar Salvador 2976369fa227SOscar Salvador return ret; 2977369fa227SOscar Salvador } 2978369fa227SOscar Salvador 2979ae37c7ffSOscar Salvador int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list) 2980369fa227SOscar Salvador { 2981369fa227SOscar Salvador struct hstate *h; 2982d5e33bd8SSidhartha Kumar struct folio *folio = page_folio(page); 2983ae37c7ffSOscar Salvador int ret = -EBUSY; 2984369fa227SOscar Salvador 2985369fa227SOscar Salvador /* 2986369fa227SOscar Salvador * The page might have been dissolved from under our feet, so make sure 2987369fa227SOscar Salvador * to carefully check the state under the lock. 2988369fa227SOscar Salvador * Return success when racing as if we dissolved the page ourselves. 2989369fa227SOscar Salvador */ 2990369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2991d5e33bd8SSidhartha Kumar if (folio_test_hugetlb(folio)) { 2992d5e33bd8SSidhartha Kumar h = folio_hstate(folio); 2993369fa227SOscar Salvador } else { 2994369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2995369fa227SOscar Salvador return 0; 2996369fa227SOscar Salvador } 2997369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2998369fa227SOscar Salvador 2999369fa227SOscar Salvador /* 3000369fa227SOscar Salvador * Fence off gigantic pages as there is a cyclic dependency between 3001369fa227SOscar Salvador * alloc_contig_range and them. Return -ENOMEM as this has the effect 3002369fa227SOscar Salvador * of bailing out right away without further retrying. 3003369fa227SOscar Salvador */ 3004369fa227SOscar Salvador if (hstate_is_gigantic(h)) 3005369fa227SOscar Salvador return -ENOMEM; 3006369fa227SOscar Salvador 3007d5e33bd8SSidhartha Kumar if (folio_ref_count(folio) && !isolate_hugetlb(&folio->page, list)) 3008ae37c7ffSOscar Salvador ret = 0; 3009d5e33bd8SSidhartha Kumar else if (!folio_ref_count(folio)) 301019fc1a7eSSidhartha Kumar ret = alloc_and_dissolve_hugetlb_folio(h, folio, list); 3011ae37c7ffSOscar Salvador 3012ae37c7ffSOscar Salvador return ret; 3013369fa227SOscar Salvador } 3014369fa227SOscar Salvador 301570c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 301604f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 3017348ea204SAdam Litke { 301890481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 3019a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3020348ea204SAdam Litke struct page *page; 3021d4ab0316SSidhartha Kumar struct folio *folio; 3022d85f69b0SMike Kravetz long map_chg, map_commit; 3023d85f69b0SMike Kravetz long gbl_chg; 30246d76dcf4SAneesh Kumar K.V int ret, idx; 30256d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 302608cf9fafSMina Almasry bool deferred_reserve; 30272fc39cecSAdam Litke 30286d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 3029a1e78772SMel Gorman /* 3030d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 3031d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 3032d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 3033a1e78772SMel Gorman */ 3034d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 3035d85f69b0SMike Kravetz if (map_chg < 0) 303676dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 3037d85f69b0SMike Kravetz 3038d85f69b0SMike Kravetz /* 3039d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 3040d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 3041d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 3042d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 3043d85f69b0SMike Kravetz * checked against any subpool limit. 3044d85f69b0SMike Kravetz */ 3045d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 3046d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 3047d85f69b0SMike Kravetz if (gbl_chg < 0) { 3048feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 304976dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 30505e911373SMike Kravetz } 305190d8b7e6SAdam Litke 3052d85f69b0SMike Kravetz /* 3053d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 3054d85f69b0SMike Kravetz * map, there could be reservations associated with the 3055d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 3056d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 3057d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 3058d85f69b0SMike Kravetz * the subpool reservations. 3059d85f69b0SMike Kravetz */ 3060d85f69b0SMike Kravetz if (avoid_reserve) 3061d85f69b0SMike Kravetz gbl_chg = 1; 3062d85f69b0SMike Kravetz } 3063d85f69b0SMike Kravetz 306408cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 306508cf9fafSMina Almasry */ 30666501fe5fSMiaohe Lin deferred_reserve = map_chg || avoid_reserve; 306708cf9fafSMina Almasry if (deferred_reserve) { 306808cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 306908cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 30708f34af6fSJianyu Zhan if (ret) 30718f34af6fSJianyu Zhan goto out_subpool_put; 307208cf9fafSMina Almasry } 307308cf9fafSMina Almasry 307408cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 307508cf9fafSMina Almasry if (ret) 307608cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 30778f34af6fSJianyu Zhan 3078db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3079d85f69b0SMike Kravetz /* 3080d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 3081d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 3082d85f69b0SMike Kravetz * a reservation exists for the allocation. 3083d85f69b0SMike Kravetz */ 3084d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 308581a6fcaeSJoonsoo Kim if (!page) { 3086db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 30870c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 30888f34af6fSJianyu Zhan if (!page) 30898f34af6fSJianyu Zhan goto out_uncharge_cgroup; 309012df140fSRik van Riel spin_lock_irq(&hugetlb_lock); 3091a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 3092d6995da3SMike Kravetz SetHPageRestoreReserve(page); 3093a88c7695SNaoya Horiguchi h->resv_huge_pages--; 3094a88c7695SNaoya Horiguchi } 309515a8d68eSWei Yang list_add(&page->lru, &h->hugepage_activelist); 30962b21624fSMike Kravetz set_page_refcounted(page); 309781a6fcaeSJoonsoo Kim /* Fall through */ 3098a1e78772SMel Gorman } 3099d4ab0316SSidhartha Kumar folio = page_folio(page); 310081a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 310108cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 310208cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 310308cf9fafSMina Almasry */ 310408cf9fafSMina Almasry if (deferred_reserve) { 310508cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 310608cf9fafSMina Almasry h_cg, page); 310708cf9fafSMina Almasry } 310808cf9fafSMina Almasry 3109db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3110a1e78772SMel Gorman 3111d6995da3SMike Kravetz hugetlb_set_page_subpool(page, spool); 3112a1e78772SMel Gorman 3113d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 3114d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 311533039678SMike Kravetz /* 311633039678SMike Kravetz * The page was added to the reservation map between 311733039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 311833039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 311933039678SMike Kravetz * Adjust for the subpool count incremented above AND 312033039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 312133039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 312233039678SMike Kravetz * no longer applies. 312333039678SMike Kravetz */ 312433039678SMike Kravetz long rsv_adjust; 312533039678SMike Kravetz 312633039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 312733039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 312879aa925bSMike Kravetz if (deferred_reserve) 3129d4ab0316SSidhartha Kumar hugetlb_cgroup_uncharge_folio_rsvd(hstate_index(h), 3130d4ab0316SSidhartha Kumar pages_per_huge_page(h), folio); 313133039678SMike Kravetz } 31327893d1d5SAdam Litke return page; 31338f34af6fSJianyu Zhan 31348f34af6fSJianyu Zhan out_uncharge_cgroup: 31358f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 313608cf9fafSMina Almasry out_uncharge_cgroup_reservation: 313708cf9fafSMina Almasry if (deferred_reserve) 313808cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 313908cf9fafSMina Almasry h_cg); 31408f34af6fSJianyu Zhan out_subpool_put: 3141d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 31428f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 3143feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 31448f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 3145b45b5bd6SDavid Gibson } 3146b45b5bd6SDavid Gibson 3147b5389086SZhenguo Yao int alloc_bootmem_huge_page(struct hstate *h, int nid) 3148e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 3149b5389086SZhenguo Yao int __alloc_bootmem_huge_page(struct hstate *h, int nid) 3150aa888a74SAndi Kleen { 3151b5389086SZhenguo Yao struct huge_bootmem_page *m = NULL; /* initialize for clang */ 3152b2261026SJoonsoo Kim int nr_nodes, node; 3153aa888a74SAndi Kleen 3154b5389086SZhenguo Yao /* do node specific alloc */ 3155b5389086SZhenguo Yao if (nid != NUMA_NO_NODE) { 3156b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), 3157b5389086SZhenguo Yao 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid); 3158b5389086SZhenguo Yao if (!m) 3159b5389086SZhenguo Yao return 0; 3160b5389086SZhenguo Yao goto found; 3161b5389086SZhenguo Yao } 3162b5389086SZhenguo Yao /* allocate from next node when distributing huge pages */ 3163b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 3164b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw( 31658b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 316697ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 3167aa888a74SAndi Kleen /* 3168aa888a74SAndi Kleen * Use the beginning of the huge page to store the 3169aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 3170aa888a74SAndi Kleen * puts them into the mem_map). 3171aa888a74SAndi Kleen */ 3172b5389086SZhenguo Yao if (!m) 3173b5389086SZhenguo Yao return 0; 3174aa888a74SAndi Kleen goto found; 3175aa888a74SAndi Kleen } 3176aa888a74SAndi Kleen 3177aa888a74SAndi Kleen found: 3178aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 3179330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 3180aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 3181aa888a74SAndi Kleen m->hstate = h; 3182aa888a74SAndi Kleen return 1; 3183aa888a74SAndi Kleen } 3184aa888a74SAndi Kleen 318548b8d744SMike Kravetz /* 318648b8d744SMike Kravetz * Put bootmem huge pages into the standard lists after mem_map is up. 318748b8d744SMike Kravetz * Note: This only applies to gigantic (order > MAX_ORDER) pages. 318848b8d744SMike Kravetz */ 3189aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 3190aa888a74SAndi Kleen { 3191aa888a74SAndi Kleen struct huge_bootmem_page *m; 3192aa888a74SAndi Kleen 3193aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 319440d18ebfSMike Kravetz struct page *page = virt_to_page(m); 31957f325a8dSSidhartha Kumar struct folio *folio = page_folio(page); 3196aa888a74SAndi Kleen struct hstate *h = m->hstate; 3197ee8f248dSBecky Bruce 319848b8d744SMike Kravetz VM_BUG_ON(!hstate_is_gigantic(h)); 3199d1c60955SSidhartha Kumar WARN_ON(folio_ref_count(folio) != 1); 3200d1c60955SSidhartha Kumar if (prep_compound_gigantic_folio(folio, huge_page_order(h))) { 3201d1c60955SSidhartha Kumar WARN_ON(folio_test_reserved(folio)); 3202d1c60955SSidhartha Kumar prep_new_hugetlb_folio(h, folio, folio_nid(folio)); 32032b21624fSMike Kravetz free_huge_page(page); /* add to the hugepage allocator */ 32047118fc29SMike Kravetz } else { 3205416d85edSMike Kravetz /* VERY unlikely inflated ref count on a tail page */ 32067f325a8dSSidhartha Kumar free_gigantic_folio(folio, huge_page_order(h)); 32077118fc29SMike Kravetz } 3208af0fb9dfSMichal Hocko 3209b0320c7bSRafael Aquini /* 321048b8d744SMike Kravetz * We need to restore the 'stolen' pages to totalram_pages 321148b8d744SMike Kravetz * in order to fix confusing memory reports from free(1) and 321248b8d744SMike Kravetz * other side-effects, like CommitLimit going negative. 3213b0320c7bSRafael Aquini */ 3214c78a7f36SMiaohe Lin adjust_managed_page_count(page, pages_per_huge_page(h)); 3215520495feSCannon Matthews cond_resched(); 3216aa888a74SAndi Kleen } 3217aa888a74SAndi Kleen } 3218b5389086SZhenguo Yao static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid) 3219b5389086SZhenguo Yao { 3220b5389086SZhenguo Yao unsigned long i; 3221b5389086SZhenguo Yao char buf[32]; 3222b5389086SZhenguo Yao 3223b5389086SZhenguo Yao for (i = 0; i < h->max_huge_pages_node[nid]; ++i) { 3224b5389086SZhenguo Yao if (hstate_is_gigantic(h)) { 3225b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, nid)) 3226b5389086SZhenguo Yao break; 3227b5389086SZhenguo Yao } else { 322819fc1a7eSSidhartha Kumar struct folio *folio; 3229b5389086SZhenguo Yao gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 3230b5389086SZhenguo Yao 323119fc1a7eSSidhartha Kumar folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, 3232b5389086SZhenguo Yao &node_states[N_MEMORY], NULL); 323319fc1a7eSSidhartha Kumar if (!folio) 3234b5389086SZhenguo Yao break; 323519fc1a7eSSidhartha Kumar free_huge_page(&folio->page); /* free it into the hugepage allocator */ 3236b5389086SZhenguo Yao } 3237b5389086SZhenguo Yao cond_resched(); 3238b5389086SZhenguo Yao } 3239b5389086SZhenguo Yao if (i == h->max_huge_pages_node[nid]) 3240b5389086SZhenguo Yao return; 3241b5389086SZhenguo Yao 3242b5389086SZhenguo Yao string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3243b5389086SZhenguo Yao pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n", 3244b5389086SZhenguo Yao h->max_huge_pages_node[nid], buf, nid, i); 3245b5389086SZhenguo Yao h->max_huge_pages -= (h->max_huge_pages_node[nid] - i); 3246b5389086SZhenguo Yao h->max_huge_pages_node[nid] = i; 3247b5389086SZhenguo Yao } 3248aa888a74SAndi Kleen 32498faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 32501da177e4SLinus Torvalds { 32511da177e4SLinus Torvalds unsigned long i; 3252f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 3253b5389086SZhenguo Yao bool node_specific_alloc = false; 3254f60858f9SMike Kravetz 3255b5389086SZhenguo Yao /* skip gigantic hugepages allocation if hugetlb_cma enabled */ 3256b5389086SZhenguo Yao if (hstate_is_gigantic(h) && hugetlb_cma_size) { 3257b5389086SZhenguo Yao pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 3258b5389086SZhenguo Yao return; 3259b5389086SZhenguo Yao } 3260b5389086SZhenguo Yao 3261b5389086SZhenguo Yao /* do node specific alloc */ 32620a7a0f6fSPeng Liu for_each_online_node(i) { 3263b5389086SZhenguo Yao if (h->max_huge_pages_node[i] > 0) { 3264b5389086SZhenguo Yao hugetlb_hstate_alloc_pages_onenode(h, i); 3265b5389086SZhenguo Yao node_specific_alloc = true; 3266b5389086SZhenguo Yao } 3267b5389086SZhenguo Yao } 3268b5389086SZhenguo Yao 3269b5389086SZhenguo Yao if (node_specific_alloc) 3270b5389086SZhenguo Yao return; 3271b5389086SZhenguo Yao 3272b5389086SZhenguo Yao /* below will do all node balanced alloc */ 3273f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 3274f60858f9SMike Kravetz /* 3275f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3276f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 3277f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 3278f60858f9SMike Kravetz * time, we are likely in bigger trouble. 3279f60858f9SMike Kravetz */ 3280f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 3281f60858f9SMike Kravetz GFP_KERNEL); 3282f60858f9SMike Kravetz } else { 3283f60858f9SMike Kravetz /* allocations done at boot time */ 3284f60858f9SMike Kravetz node_alloc_noretry = NULL; 3285f60858f9SMike Kravetz } 3286f60858f9SMike Kravetz 3287f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 3288f60858f9SMike Kravetz if (node_alloc_noretry) 3289f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 32901da177e4SLinus Torvalds 3291e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 3292bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 3293b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, NUMA_NO_NODE)) 3294aa888a74SAndi Kleen break; 32950c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 3296f60858f9SMike Kravetz &node_states[N_MEMORY], 3297f60858f9SMike Kravetz node_alloc_noretry)) 32981da177e4SLinus Torvalds break; 329969ed779aSDavid Rientjes cond_resched(); 33001da177e4SLinus Torvalds } 3301d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 3302d715cf80SLiam R. Howlett char buf[32]; 3303d715cf80SLiam R. Howlett 3304c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3305d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 3306d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 33078faa8b07SAndi Kleen h->max_huge_pages = i; 3308e5ff2159SAndi Kleen } 3309f60858f9SMike Kravetz kfree(node_alloc_noretry); 3310d715cf80SLiam R. Howlett } 3311e5ff2159SAndi Kleen 3312e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 3313e5ff2159SAndi Kleen { 331479dfc695SMike Kravetz struct hstate *h, *h2; 3315e5ff2159SAndi Kleen 3316e5ff2159SAndi Kleen for_each_hstate(h) { 33178faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 3318bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 33198faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 332079dfc695SMike Kravetz 332179dfc695SMike Kravetz /* 332279dfc695SMike Kravetz * Set demote order for each hstate. Note that 332379dfc695SMike Kravetz * h->demote_order is initially 0. 332479dfc695SMike Kravetz * - We can not demote gigantic pages if runtime freeing 332579dfc695SMike Kravetz * is not supported, so skip this. 3326a01f4390SMike Kravetz * - If CMA allocation is possible, we can not demote 3327a01f4390SMike Kravetz * HUGETLB_PAGE_ORDER or smaller size pages. 332879dfc695SMike Kravetz */ 332979dfc695SMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 333079dfc695SMike Kravetz continue; 3331a01f4390SMike Kravetz if (hugetlb_cma_size && h->order <= HUGETLB_PAGE_ORDER) 3332a01f4390SMike Kravetz continue; 333379dfc695SMike Kravetz for_each_hstate(h2) { 333479dfc695SMike Kravetz if (h2 == h) 333579dfc695SMike Kravetz continue; 333679dfc695SMike Kravetz if (h2->order < h->order && 333779dfc695SMike Kravetz h2->order > h->demote_order) 333879dfc695SMike Kravetz h->demote_order = h2->order; 333979dfc695SMike Kravetz } 3340e5ff2159SAndi Kleen } 3341e5ff2159SAndi Kleen } 3342e5ff2159SAndi Kleen 3343e5ff2159SAndi Kleen static void __init report_hugepages(void) 3344e5ff2159SAndi Kleen { 3345e5ff2159SAndi Kleen struct hstate *h; 3346e5ff2159SAndi Kleen 3347e5ff2159SAndi Kleen for_each_hstate(h) { 33484abd32dbSAndi Kleen char buf[32]; 3349c6247f72SMatthew Wilcox 3350c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 33516213834cSMuchun Song pr_info("HugeTLB: registered %s page size, pre-allocated %ld pages\n", 3352c6247f72SMatthew Wilcox buf, h->free_huge_pages); 33536213834cSMuchun Song pr_info("HugeTLB: %d KiB vmemmap can be freed for a %s page\n", 33546213834cSMuchun Song hugetlb_vmemmap_optimizable_size(h) / SZ_1K, buf); 3355e5ff2159SAndi Kleen } 3356e5ff2159SAndi Kleen } 3357e5ff2159SAndi Kleen 33581da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 33596ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 33606ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 33611da177e4SLinus Torvalds { 33624415cc8dSChristoph Lameter int i; 33631121828aSMike Kravetz LIST_HEAD(page_list); 33644415cc8dSChristoph Lameter 33659487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 3366bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3367aa888a74SAndi Kleen return; 3368aa888a74SAndi Kleen 33691121828aSMike Kravetz /* 33701121828aSMike Kravetz * Collect pages to be freed on a list, and free after dropping lock 33711121828aSMike Kravetz */ 33726ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 337310c6ec49SMike Kravetz struct page *page, *next; 3374a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 3375a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 3376a5516438SAndi Kleen if (count >= h->nr_huge_pages) 33771121828aSMike Kravetz goto out; 33781da177e4SLinus Torvalds if (PageHighMem(page)) 33791da177e4SLinus Torvalds continue; 3380cfd5082bSSidhartha Kumar remove_hugetlb_folio(h, page_folio(page), false); 33811121828aSMike Kravetz list_add(&page->lru, &page_list); 33821121828aSMike Kravetz } 33831121828aSMike Kravetz } 33841121828aSMike Kravetz 33851121828aSMike Kravetz out: 3386db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 338710c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3388db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 33891da177e4SLinus Torvalds } 33901da177e4SLinus Torvalds #else 33916ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 33926ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 33931da177e4SLinus Torvalds { 33941da177e4SLinus Torvalds } 33951da177e4SLinus Torvalds #endif 33961da177e4SLinus Torvalds 339720a0307cSWu Fengguang /* 339820a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 339920a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 340020a0307cSWu Fengguang * Returns 1 if an adjustment was made. 340120a0307cSWu Fengguang */ 34026ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 34036ae11b27SLee Schermerhorn int delta) 340420a0307cSWu Fengguang { 3405b2261026SJoonsoo Kim int nr_nodes, node; 340620a0307cSWu Fengguang 34079487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 340820a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 340920a0307cSWu Fengguang 3410e8c5c824SLee Schermerhorn if (delta < 0) { 3411b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 3412b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 3413b2261026SJoonsoo Kim goto found; 3414b2261026SJoonsoo Kim } 3415b2261026SJoonsoo Kim } else { 3416b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 3417b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 3418b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 3419b2261026SJoonsoo Kim goto found; 3420e8c5c824SLee Schermerhorn } 34219a76db09SLee Schermerhorn } 3422b2261026SJoonsoo Kim return 0; 342320a0307cSWu Fengguang 3424b2261026SJoonsoo Kim found: 342520a0307cSWu Fengguang h->surplus_huge_pages += delta; 3426b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 3427b2261026SJoonsoo Kim return 1; 342820a0307cSWu Fengguang } 342920a0307cSWu Fengguang 3430a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 3431fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 34326ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 34331da177e4SLinus Torvalds { 34347893d1d5SAdam Litke unsigned long min_count, ret; 343510c6ec49SMike Kravetz struct page *page; 343610c6ec49SMike Kravetz LIST_HEAD(page_list); 3437f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 3438f60858f9SMike Kravetz 3439f60858f9SMike Kravetz /* 3440f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3441f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 3442f60858f9SMike Kravetz * the requested huge pages. 3443f60858f9SMike Kravetz */ 3444f60858f9SMike Kravetz if (node_alloc_noretry) 3445f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 3446f60858f9SMike Kravetz else 3447f60858f9SMike Kravetz return -ENOMEM; 34481da177e4SLinus Torvalds 344929383967SMike Kravetz /* 345029383967SMike Kravetz * resize_lock mutex prevents concurrent adjustments to number of 345129383967SMike Kravetz * pages in hstate via the proc/sysfs interfaces. 345229383967SMike Kravetz */ 345329383967SMike Kravetz mutex_lock(&h->resize_lock); 3454b65d4adbSMuchun Song flush_free_hpage_work(h); 3455db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 34564eb0716eSAlexandre Ghiti 34574eb0716eSAlexandre Ghiti /* 3458fd875dcaSMike Kravetz * Check for a node specific request. 3459fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 3460fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 3461fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 3462fd875dcaSMike Kravetz */ 3463fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 3464fd875dcaSMike Kravetz unsigned long old_count = count; 3465fd875dcaSMike Kravetz 3466fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 3467fd875dcaSMike Kravetz /* 3468fd875dcaSMike Kravetz * User may have specified a large count value which caused the 3469fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 3470fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 3471fd875dcaSMike Kravetz * largest possible value to align with their intention. 3472fd875dcaSMike Kravetz */ 3473fd875dcaSMike Kravetz if (count < old_count) 3474fd875dcaSMike Kravetz count = ULONG_MAX; 3475fd875dcaSMike Kravetz } 3476fd875dcaSMike Kravetz 3477fd875dcaSMike Kravetz /* 34784eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 34794eb0716eSAlexandre Ghiti * page range allocation. 34804eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 34814eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 34824eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 34834eb0716eSAlexandre Ghiti */ 34844eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 34854eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 3486db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 348729383967SMike Kravetz mutex_unlock(&h->resize_lock); 3488f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 34894eb0716eSAlexandre Ghiti return -EINVAL; 34904eb0716eSAlexandre Ghiti } 34914eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 34924eb0716eSAlexandre Ghiti } 3493aa888a74SAndi Kleen 34947893d1d5SAdam Litke /* 34957893d1d5SAdam Litke * Increase the pool size 34967893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 34977893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 3498d1c3fb1fSNishanth Aravamudan * 34990c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 3500d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 3501d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 3502d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 3503d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 35047893d1d5SAdam Litke */ 3505a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 35066ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 35077893d1d5SAdam Litke break; 35087893d1d5SAdam Litke } 35097893d1d5SAdam Litke 3510a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 35117893d1d5SAdam Litke /* 35127893d1d5SAdam Litke * If this allocation races such that we no longer need the 35137893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 35147893d1d5SAdam Litke * and reducing the surplus. 35157893d1d5SAdam Litke */ 3516db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3517649920c6SJia He 3518649920c6SJia He /* yield cpu to avoid soft lockup */ 3519649920c6SJia He cond_resched(); 3520649920c6SJia He 3521f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 3522f60858f9SMike Kravetz node_alloc_noretry); 3523db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 35247893d1d5SAdam Litke if (!ret) 35257893d1d5SAdam Litke goto out; 35267893d1d5SAdam Litke 3527536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 3528536240f2SMel Gorman if (signal_pending(current)) 3529536240f2SMel Gorman goto out; 35307893d1d5SAdam Litke } 35317893d1d5SAdam Litke 35327893d1d5SAdam Litke /* 35337893d1d5SAdam Litke * Decrease the pool size 35347893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 35357893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 35367893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 35377893d1d5SAdam Litke * to the desired size as pages become free. 3538d1c3fb1fSNishanth Aravamudan * 3539d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 3540d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 3541d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 35420c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 3543d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 3544d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 3545d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 35467893d1d5SAdam Litke */ 3547a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 35486b0c880dSAdam Litke min_count = max(count, min_count); 35496ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 355010c6ec49SMike Kravetz 355110c6ec49SMike Kravetz /* 355210c6ec49SMike Kravetz * Collect pages to be removed on list without dropping lock 355310c6ec49SMike Kravetz */ 3554a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 355510c6ec49SMike Kravetz page = remove_pool_huge_page(h, nodes_allowed, 0); 355610c6ec49SMike Kravetz if (!page) 35571da177e4SLinus Torvalds break; 355810c6ec49SMike Kravetz 355910c6ec49SMike Kravetz list_add(&page->lru, &page_list); 35601da177e4SLinus Torvalds } 356110c6ec49SMike Kravetz /* free the pages after dropping lock */ 3562db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 356310c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3564b65d4adbSMuchun Song flush_free_hpage_work(h); 3565db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 356610c6ec49SMike Kravetz 3567a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 35686ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 35697893d1d5SAdam Litke break; 35707893d1d5SAdam Litke } 35717893d1d5SAdam Litke out: 35724eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 3573db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 357429383967SMike Kravetz mutex_unlock(&h->resize_lock); 35754eb0716eSAlexandre Ghiti 3576f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 3577f60858f9SMike Kravetz 35784eb0716eSAlexandre Ghiti return 0; 35791da177e4SLinus Torvalds } 35801da177e4SLinus Torvalds 35818531fc6fSMike Kravetz static int demote_free_huge_page(struct hstate *h, struct page *page) 35828531fc6fSMike Kravetz { 35838531fc6fSMike Kravetz int i, nid = page_to_nid(page); 35848531fc6fSMike Kravetz struct hstate *target_hstate; 3585911565b8SSidhartha Kumar struct folio *folio = page_folio(page); 358631731452SDoug Berger struct page *subpage; 35878531fc6fSMike Kravetz int rc = 0; 35888531fc6fSMike Kravetz 35898531fc6fSMike Kravetz target_hstate = size_to_hstate(PAGE_SIZE << h->demote_order); 35908531fc6fSMike Kravetz 3591cfd5082bSSidhartha Kumar remove_hugetlb_folio_for_demote(h, folio, false); 35928531fc6fSMike Kravetz spin_unlock_irq(&hugetlb_lock); 35938531fc6fSMike Kravetz 35946213834cSMuchun Song rc = hugetlb_vmemmap_restore(h, page); 35958531fc6fSMike Kravetz if (rc) { 35968531fc6fSMike Kravetz /* Allocation of vmemmmap failed, we can not demote page */ 35978531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 35988531fc6fSMike Kravetz set_page_refcounted(page); 35992f6c57d6SSidhartha Kumar add_hugetlb_folio(h, page_folio(page), false); 36008531fc6fSMike Kravetz return rc; 36018531fc6fSMike Kravetz } 36028531fc6fSMike Kravetz 36038531fc6fSMike Kravetz /* 3604911565b8SSidhartha Kumar * Use destroy_compound_hugetlb_folio_for_demote for all huge page 36058531fc6fSMike Kravetz * sizes as it will not ref count pages. 36068531fc6fSMike Kravetz */ 3607911565b8SSidhartha Kumar destroy_compound_hugetlb_folio_for_demote(folio, huge_page_order(h)); 36088531fc6fSMike Kravetz 36098531fc6fSMike Kravetz /* 36108531fc6fSMike Kravetz * Taking target hstate mutex synchronizes with set_max_huge_pages. 36118531fc6fSMike Kravetz * Without the mutex, pages added to target hstate could be marked 36128531fc6fSMike Kravetz * as surplus. 36138531fc6fSMike Kravetz * 36148531fc6fSMike Kravetz * Note that we already hold h->resize_lock. To prevent deadlock, 36158531fc6fSMike Kravetz * use the convention of always taking larger size hstate mutex first. 36168531fc6fSMike Kravetz */ 36178531fc6fSMike Kravetz mutex_lock(&target_hstate->resize_lock); 36188531fc6fSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 36198531fc6fSMike Kravetz i += pages_per_huge_page(target_hstate)) { 362031731452SDoug Berger subpage = nth_page(page, i); 3621d1c60955SSidhartha Kumar folio = page_folio(subpage); 36228531fc6fSMike Kravetz if (hstate_is_gigantic(target_hstate)) 3623d1c60955SSidhartha Kumar prep_compound_gigantic_folio_for_demote(folio, 36248531fc6fSMike Kravetz target_hstate->order); 36258531fc6fSMike Kravetz else 362631731452SDoug Berger prep_compound_page(subpage, target_hstate->order); 362731731452SDoug Berger set_page_private(subpage, 0); 3628d1c60955SSidhartha Kumar prep_new_hugetlb_folio(target_hstate, folio, nid); 36292b21624fSMike Kravetz free_huge_page(subpage); 36308531fc6fSMike Kravetz } 36318531fc6fSMike Kravetz mutex_unlock(&target_hstate->resize_lock); 36328531fc6fSMike Kravetz 36338531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 36348531fc6fSMike Kravetz 36358531fc6fSMike Kravetz /* 36368531fc6fSMike Kravetz * Not absolutely necessary, but for consistency update max_huge_pages 36378531fc6fSMike Kravetz * based on pool changes for the demoted page. 36388531fc6fSMike Kravetz */ 36398531fc6fSMike Kravetz h->max_huge_pages--; 3640a43a83c7SMiaohe Lin target_hstate->max_huge_pages += 3641a43a83c7SMiaohe Lin pages_per_huge_page(h) / pages_per_huge_page(target_hstate); 36428531fc6fSMike Kravetz 36438531fc6fSMike Kravetz return rc; 36448531fc6fSMike Kravetz } 36458531fc6fSMike Kravetz 364679dfc695SMike Kravetz static int demote_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed) 364779dfc695SMike Kravetz __must_hold(&hugetlb_lock) 364879dfc695SMike Kravetz { 36498531fc6fSMike Kravetz int nr_nodes, node; 36508531fc6fSMike Kravetz struct page *page; 365179dfc695SMike Kravetz 365279dfc695SMike Kravetz lockdep_assert_held(&hugetlb_lock); 365379dfc695SMike Kravetz 365479dfc695SMike Kravetz /* We should never get here if no demote order */ 365579dfc695SMike Kravetz if (!h->demote_order) { 365679dfc695SMike Kravetz pr_warn("HugeTLB: NULL demote order passed to demote_pool_huge_page.\n"); 365779dfc695SMike Kravetz return -EINVAL; /* internal error */ 365879dfc695SMike Kravetz } 365979dfc695SMike Kravetz 36608531fc6fSMike Kravetz for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 36615a317412SMike Kravetz list_for_each_entry(page, &h->hugepage_freelists[node], lru) { 36625a317412SMike Kravetz if (PageHWPoison(page)) 36635a317412SMike Kravetz continue; 36645a317412SMike Kravetz 36655a317412SMike Kravetz return demote_free_huge_page(h, page); 36668531fc6fSMike Kravetz } 36678531fc6fSMike Kravetz } 36688531fc6fSMike Kravetz 36695a317412SMike Kravetz /* 36705a317412SMike Kravetz * Only way to get here is if all pages on free lists are poisoned. 36715a317412SMike Kravetz * Return -EBUSY so that caller will not retry. 36725a317412SMike Kravetz */ 36735a317412SMike Kravetz return -EBUSY; 367479dfc695SMike Kravetz } 367579dfc695SMike Kravetz 3676a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 3677a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 3678a3437870SNishanth Aravamudan 367979dfc695SMike Kravetz #define HSTATE_ATTR_WO(_name) \ 368079dfc695SMike Kravetz static struct kobj_attribute _name##_attr = __ATTR_WO(_name) 368179dfc695SMike Kravetz 3682a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 368398bc26acSMiaohe Lin static struct kobj_attribute _name##_attr = __ATTR_RW(_name) 3684a3437870SNishanth Aravamudan 3685a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 3686a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 3687a3437870SNishanth Aravamudan 36889a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 36899a305230SLee Schermerhorn 36909a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 3691a3437870SNishanth Aravamudan { 3692a3437870SNishanth Aravamudan int i; 36939a305230SLee Schermerhorn 3694a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 36959a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 36969a305230SLee Schermerhorn if (nidp) 36979a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 3698a3437870SNishanth Aravamudan return &hstates[i]; 36999a305230SLee Schermerhorn } 37009a305230SLee Schermerhorn 37019a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 3702a3437870SNishanth Aravamudan } 3703a3437870SNishanth Aravamudan 370406808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 3705a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3706a3437870SNishanth Aravamudan { 37079a305230SLee Schermerhorn struct hstate *h; 37089a305230SLee Schermerhorn unsigned long nr_huge_pages; 37099a305230SLee Schermerhorn int nid; 37109a305230SLee Schermerhorn 37119a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 37129a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 37139a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 37149a305230SLee Schermerhorn else 37159a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 37169a305230SLee Schermerhorn 3717ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", nr_huge_pages); 3718a3437870SNishanth Aravamudan } 3719adbe8726SEric B Munson 3720238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 3721238d3c13SDavid Rientjes struct hstate *h, int nid, 3722238d3c13SDavid Rientjes unsigned long count, size_t len) 3723a3437870SNishanth Aravamudan { 3724a3437870SNishanth Aravamudan int err; 37252d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 3726a3437870SNishanth Aravamudan 37272d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 37282d0adf7eSOscar Salvador return -EINVAL; 3729adbe8726SEric B Munson 37309a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 37319a305230SLee Schermerhorn /* 37329a305230SLee Schermerhorn * global hstate attribute 37339a305230SLee Schermerhorn */ 37349a305230SLee Schermerhorn if (!(obey_mempolicy && 37352d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 37362d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 37372d0adf7eSOscar Salvador else 37382d0adf7eSOscar Salvador n_mask = &nodes_allowed; 37392d0adf7eSOscar Salvador } else { 37409a305230SLee Schermerhorn /* 3741fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 3742fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 37439a305230SLee Schermerhorn */ 37442d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 37452d0adf7eSOscar Salvador n_mask = &nodes_allowed; 3746fd875dcaSMike Kravetz } 37479a305230SLee Schermerhorn 37482d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 374906808b08SLee Schermerhorn 37504eb0716eSAlexandre Ghiti return err ? err : len; 375106808b08SLee Schermerhorn } 375206808b08SLee Schermerhorn 3753238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 3754238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 3755238d3c13SDavid Rientjes size_t len) 3756238d3c13SDavid Rientjes { 3757238d3c13SDavid Rientjes struct hstate *h; 3758238d3c13SDavid Rientjes unsigned long count; 3759238d3c13SDavid Rientjes int nid; 3760238d3c13SDavid Rientjes int err; 3761238d3c13SDavid Rientjes 3762238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 3763238d3c13SDavid Rientjes if (err) 3764238d3c13SDavid Rientjes return err; 3765238d3c13SDavid Rientjes 3766238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 3767238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 3768238d3c13SDavid Rientjes } 3769238d3c13SDavid Rientjes 377006808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 377106808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 377206808b08SLee Schermerhorn { 377306808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 377406808b08SLee Schermerhorn } 377506808b08SLee Schermerhorn 377606808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 377706808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 377806808b08SLee Schermerhorn { 3779238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 3780a3437870SNishanth Aravamudan } 3781a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 3782a3437870SNishanth Aravamudan 378306808b08SLee Schermerhorn #ifdef CONFIG_NUMA 378406808b08SLee Schermerhorn 378506808b08SLee Schermerhorn /* 378606808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 378706808b08SLee Schermerhorn * huge page alloc/free. 378806808b08SLee Schermerhorn */ 378906808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 3790ae7a927dSJoe Perches struct kobj_attribute *attr, 3791ae7a927dSJoe Perches char *buf) 379206808b08SLee Schermerhorn { 379306808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 379406808b08SLee Schermerhorn } 379506808b08SLee Schermerhorn 379606808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 379706808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 379806808b08SLee Schermerhorn { 3799238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 380006808b08SLee Schermerhorn } 380106808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 380206808b08SLee Schermerhorn #endif 380306808b08SLee Schermerhorn 380406808b08SLee Schermerhorn 3805a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 3806a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3807a3437870SNishanth Aravamudan { 38089a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3809ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages); 3810a3437870SNishanth Aravamudan } 3811adbe8726SEric B Munson 3812a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 3813a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 3814a3437870SNishanth Aravamudan { 3815a3437870SNishanth Aravamudan int err; 3816a3437870SNishanth Aravamudan unsigned long input; 38179a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3818a3437870SNishanth Aravamudan 3819bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3820adbe8726SEric B Munson return -EINVAL; 3821adbe8726SEric B Munson 38223dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 3823a3437870SNishanth Aravamudan if (err) 382473ae31e5SEric B Munson return err; 3825a3437870SNishanth Aravamudan 3826db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3827a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 3828db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3829a3437870SNishanth Aravamudan 3830a3437870SNishanth Aravamudan return count; 3831a3437870SNishanth Aravamudan } 3832a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 3833a3437870SNishanth Aravamudan 3834a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 3835a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3836a3437870SNishanth Aravamudan { 38379a305230SLee Schermerhorn struct hstate *h; 38389a305230SLee Schermerhorn unsigned long free_huge_pages; 38399a305230SLee Schermerhorn int nid; 38409a305230SLee Schermerhorn 38419a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 38429a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 38439a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 38449a305230SLee Schermerhorn else 38459a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 38469a305230SLee Schermerhorn 3847ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", free_huge_pages); 3848a3437870SNishanth Aravamudan } 3849a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 3850a3437870SNishanth Aravamudan 3851a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 3852a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3853a3437870SNishanth Aravamudan { 38549a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3855ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->resv_huge_pages); 3856a3437870SNishanth Aravamudan } 3857a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 3858a3437870SNishanth Aravamudan 3859a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 3860a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3861a3437870SNishanth Aravamudan { 38629a305230SLee Schermerhorn struct hstate *h; 38639a305230SLee Schermerhorn unsigned long surplus_huge_pages; 38649a305230SLee Schermerhorn int nid; 38659a305230SLee Schermerhorn 38669a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 38679a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 38689a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 38699a305230SLee Schermerhorn else 38709a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 38719a305230SLee Schermerhorn 3872ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", surplus_huge_pages); 3873a3437870SNishanth Aravamudan } 3874a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3875a3437870SNishanth Aravamudan 387679dfc695SMike Kravetz static ssize_t demote_store(struct kobject *kobj, 387779dfc695SMike Kravetz struct kobj_attribute *attr, const char *buf, size_t len) 387879dfc695SMike Kravetz { 387979dfc695SMike Kravetz unsigned long nr_demote; 388079dfc695SMike Kravetz unsigned long nr_available; 388179dfc695SMike Kravetz nodemask_t nodes_allowed, *n_mask; 388279dfc695SMike Kravetz struct hstate *h; 38838eeda55fSLi zeming int err; 388479dfc695SMike Kravetz int nid; 388579dfc695SMike Kravetz 388679dfc695SMike Kravetz err = kstrtoul(buf, 10, &nr_demote); 388779dfc695SMike Kravetz if (err) 388879dfc695SMike Kravetz return err; 388979dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 389079dfc695SMike Kravetz 389179dfc695SMike Kravetz if (nid != NUMA_NO_NODE) { 389279dfc695SMike Kravetz init_nodemask_of_node(&nodes_allowed, nid); 389379dfc695SMike Kravetz n_mask = &nodes_allowed; 389479dfc695SMike Kravetz } else { 389579dfc695SMike Kravetz n_mask = &node_states[N_MEMORY]; 389679dfc695SMike Kravetz } 389779dfc695SMike Kravetz 389879dfc695SMike Kravetz /* Synchronize with other sysfs operations modifying huge pages */ 389979dfc695SMike Kravetz mutex_lock(&h->resize_lock); 390079dfc695SMike Kravetz spin_lock_irq(&hugetlb_lock); 390179dfc695SMike Kravetz 390279dfc695SMike Kravetz while (nr_demote) { 390379dfc695SMike Kravetz /* 390479dfc695SMike Kravetz * Check for available pages to demote each time thorough the 390579dfc695SMike Kravetz * loop as demote_pool_huge_page will drop hugetlb_lock. 390679dfc695SMike Kravetz */ 390779dfc695SMike Kravetz if (nid != NUMA_NO_NODE) 390879dfc695SMike Kravetz nr_available = h->free_huge_pages_node[nid]; 390979dfc695SMike Kravetz else 391079dfc695SMike Kravetz nr_available = h->free_huge_pages; 391179dfc695SMike Kravetz nr_available -= h->resv_huge_pages; 391279dfc695SMike Kravetz if (!nr_available) 391379dfc695SMike Kravetz break; 391479dfc695SMike Kravetz 391579dfc695SMike Kravetz err = demote_pool_huge_page(h, n_mask); 391679dfc695SMike Kravetz if (err) 391779dfc695SMike Kravetz break; 391879dfc695SMike Kravetz 391979dfc695SMike Kravetz nr_demote--; 392079dfc695SMike Kravetz } 392179dfc695SMike Kravetz 392279dfc695SMike Kravetz spin_unlock_irq(&hugetlb_lock); 392379dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 392479dfc695SMike Kravetz 392579dfc695SMike Kravetz if (err) 392679dfc695SMike Kravetz return err; 392779dfc695SMike Kravetz return len; 392879dfc695SMike Kravetz } 392979dfc695SMike Kravetz HSTATE_ATTR_WO(demote); 393079dfc695SMike Kravetz 393179dfc695SMike Kravetz static ssize_t demote_size_show(struct kobject *kobj, 393279dfc695SMike Kravetz struct kobj_attribute *attr, char *buf) 393379dfc695SMike Kravetz { 393412658abfSMiaohe Lin struct hstate *h = kobj_to_hstate(kobj, NULL); 393579dfc695SMike Kravetz unsigned long demote_size = (PAGE_SIZE << h->demote_order) / SZ_1K; 393679dfc695SMike Kravetz 393779dfc695SMike Kravetz return sysfs_emit(buf, "%lukB\n", demote_size); 393879dfc695SMike Kravetz } 393979dfc695SMike Kravetz 394079dfc695SMike Kravetz static ssize_t demote_size_store(struct kobject *kobj, 394179dfc695SMike Kravetz struct kobj_attribute *attr, 394279dfc695SMike Kravetz const char *buf, size_t count) 394379dfc695SMike Kravetz { 394479dfc695SMike Kravetz struct hstate *h, *demote_hstate; 394579dfc695SMike Kravetz unsigned long demote_size; 394679dfc695SMike Kravetz unsigned int demote_order; 394779dfc695SMike Kravetz 394879dfc695SMike Kravetz demote_size = (unsigned long)memparse(buf, NULL); 394979dfc695SMike Kravetz 395079dfc695SMike Kravetz demote_hstate = size_to_hstate(demote_size); 395179dfc695SMike Kravetz if (!demote_hstate) 395279dfc695SMike Kravetz return -EINVAL; 395379dfc695SMike Kravetz demote_order = demote_hstate->order; 3954a01f4390SMike Kravetz if (demote_order < HUGETLB_PAGE_ORDER) 3955a01f4390SMike Kravetz return -EINVAL; 395679dfc695SMike Kravetz 395779dfc695SMike Kravetz /* demote order must be smaller than hstate order */ 395812658abfSMiaohe Lin h = kobj_to_hstate(kobj, NULL); 395979dfc695SMike Kravetz if (demote_order >= h->order) 396079dfc695SMike Kravetz return -EINVAL; 396179dfc695SMike Kravetz 396279dfc695SMike Kravetz /* resize_lock synchronizes access to demote size and writes */ 396379dfc695SMike Kravetz mutex_lock(&h->resize_lock); 396479dfc695SMike Kravetz h->demote_order = demote_order; 396579dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 396679dfc695SMike Kravetz 396779dfc695SMike Kravetz return count; 396879dfc695SMike Kravetz } 396979dfc695SMike Kravetz HSTATE_ATTR(demote_size); 397079dfc695SMike Kravetz 3971a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3972a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3973a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3974a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3975a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3976a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 397706808b08SLee Schermerhorn #ifdef CONFIG_NUMA 397806808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 397906808b08SLee Schermerhorn #endif 3980a3437870SNishanth Aravamudan NULL, 3981a3437870SNishanth Aravamudan }; 3982a3437870SNishanth Aravamudan 398367e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3984a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3985a3437870SNishanth Aravamudan }; 3986a3437870SNishanth Aravamudan 398779dfc695SMike Kravetz static struct attribute *hstate_demote_attrs[] = { 398879dfc695SMike Kravetz &demote_size_attr.attr, 398979dfc695SMike Kravetz &demote_attr.attr, 399079dfc695SMike Kravetz NULL, 399179dfc695SMike Kravetz }; 399279dfc695SMike Kravetz 399379dfc695SMike Kravetz static const struct attribute_group hstate_demote_attr_group = { 399479dfc695SMike Kravetz .attrs = hstate_demote_attrs, 399579dfc695SMike Kravetz }; 399679dfc695SMike Kravetz 3997094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 39989a305230SLee Schermerhorn struct kobject **hstate_kobjs, 399967e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 4000a3437870SNishanth Aravamudan { 4001a3437870SNishanth Aravamudan int retval; 4002972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 4003a3437870SNishanth Aravamudan 40049a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 40059a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 4006a3437870SNishanth Aravamudan return -ENOMEM; 4007a3437870SNishanth Aravamudan 40089a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 4009cc2205a6SMiaohe Lin if (retval) { 40109a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 4011cc2205a6SMiaohe Lin hstate_kobjs[hi] = NULL; 40123a6bdda0SMiaohe Lin return retval; 4013cc2205a6SMiaohe Lin } 4014a3437870SNishanth Aravamudan 401579dfc695SMike Kravetz if (h->demote_order) { 401601088a60SMiaohe Lin retval = sysfs_create_group(hstate_kobjs[hi], 401701088a60SMiaohe Lin &hstate_demote_attr_group); 401801088a60SMiaohe Lin if (retval) { 401979dfc695SMike Kravetz pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name); 402001088a60SMiaohe Lin sysfs_remove_group(hstate_kobjs[hi], hstate_attr_group); 402101088a60SMiaohe Lin kobject_put(hstate_kobjs[hi]); 402201088a60SMiaohe Lin hstate_kobjs[hi] = NULL; 402301088a60SMiaohe Lin return retval; 402401088a60SMiaohe Lin } 402579dfc695SMike Kravetz } 402679dfc695SMike Kravetz 402701088a60SMiaohe Lin return 0; 4028a3437870SNishanth Aravamudan } 4029a3437870SNishanth Aravamudan 40309a305230SLee Schermerhorn #ifdef CONFIG_NUMA 4031a4a00b45SMuchun Song static bool hugetlb_sysfs_initialized __ro_after_init; 40329a305230SLee Schermerhorn 40339a305230SLee Schermerhorn /* 40349a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 403510fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 403610fbcf4cSKay Sievers * index of a node device or _hstate == node id. 403710fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 40389a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 40399a305230SLee Schermerhorn */ 40409a305230SLee Schermerhorn struct node_hstate { 40419a305230SLee Schermerhorn struct kobject *hugepages_kobj; 40429a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 40439a305230SLee Schermerhorn }; 4044b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 40459a305230SLee Schermerhorn 40469a305230SLee Schermerhorn /* 404710fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 40489a305230SLee Schermerhorn */ 40499a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 40509a305230SLee Schermerhorn &nr_hugepages_attr.attr, 40519a305230SLee Schermerhorn &free_hugepages_attr.attr, 40529a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 40539a305230SLee Schermerhorn NULL, 40549a305230SLee Schermerhorn }; 40559a305230SLee Schermerhorn 405667e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 40579a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 40589a305230SLee Schermerhorn }; 40599a305230SLee Schermerhorn 40609a305230SLee Schermerhorn /* 406110fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 40629a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 40639a305230SLee Schermerhorn */ 40649a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 40659a305230SLee Schermerhorn { 40669a305230SLee Schermerhorn int nid; 40679a305230SLee Schermerhorn 40689a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 40699a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 40709a305230SLee Schermerhorn int i; 40719a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 40729a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 40739a305230SLee Schermerhorn if (nidp) 40749a305230SLee Schermerhorn *nidp = nid; 40759a305230SLee Schermerhorn return &hstates[i]; 40769a305230SLee Schermerhorn } 40779a305230SLee Schermerhorn } 40789a305230SLee Schermerhorn 40799a305230SLee Schermerhorn BUG(); 40809a305230SLee Schermerhorn return NULL; 40819a305230SLee Schermerhorn } 40829a305230SLee Schermerhorn 40839a305230SLee Schermerhorn /* 408410fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 40859a305230SLee Schermerhorn * No-op if no hstate attributes attached. 40869a305230SLee Schermerhorn */ 4087a4a00b45SMuchun Song void hugetlb_unregister_node(struct node *node) 40889a305230SLee Schermerhorn { 40899a305230SLee Schermerhorn struct hstate *h; 409010fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 40919a305230SLee Schermerhorn 40929a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 40939b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 40949a305230SLee Schermerhorn 4095972dc4deSAneesh Kumar K.V for_each_hstate(h) { 4096972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 409701088a60SMiaohe Lin struct kobject *hstate_kobj = nhs->hstate_kobjs[idx]; 409801088a60SMiaohe Lin 409901088a60SMiaohe Lin if (!hstate_kobj) 410001088a60SMiaohe Lin continue; 410101088a60SMiaohe Lin if (h->demote_order) 410201088a60SMiaohe Lin sysfs_remove_group(hstate_kobj, &hstate_demote_attr_group); 410301088a60SMiaohe Lin sysfs_remove_group(hstate_kobj, &per_node_hstate_attr_group); 410401088a60SMiaohe Lin kobject_put(hstate_kobj); 4105972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 4106972dc4deSAneesh Kumar K.V } 41079a305230SLee Schermerhorn 41089a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 41099a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 41109a305230SLee Schermerhorn } 41119a305230SLee Schermerhorn 41129a305230SLee Schermerhorn 41139a305230SLee Schermerhorn /* 411410fbcf4cSKay Sievers * Register hstate attributes for a single node device. 41159a305230SLee Schermerhorn * No-op if attributes already registered. 41169a305230SLee Schermerhorn */ 4117a4a00b45SMuchun Song void hugetlb_register_node(struct node *node) 41189a305230SLee Schermerhorn { 41199a305230SLee Schermerhorn struct hstate *h; 412010fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 41219a305230SLee Schermerhorn int err; 41229a305230SLee Schermerhorn 4123a4a00b45SMuchun Song if (!hugetlb_sysfs_initialized) 4124a4a00b45SMuchun Song return; 4125a4a00b45SMuchun Song 41269a305230SLee Schermerhorn if (nhs->hugepages_kobj) 41279a305230SLee Schermerhorn return; /* already allocated */ 41289a305230SLee Schermerhorn 41299a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 413010fbcf4cSKay Sievers &node->dev.kobj); 41319a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 41329a305230SLee Schermerhorn return; 41339a305230SLee Schermerhorn 41349a305230SLee Schermerhorn for_each_hstate(h) { 41359a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 41369a305230SLee Schermerhorn nhs->hstate_kobjs, 41379a305230SLee Schermerhorn &per_node_hstate_attr_group); 41389a305230SLee Schermerhorn if (err) { 4139282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 414010fbcf4cSKay Sievers h->name, node->dev.id); 41419a305230SLee Schermerhorn hugetlb_unregister_node(node); 41429a305230SLee Schermerhorn break; 41439a305230SLee Schermerhorn } 41449a305230SLee Schermerhorn } 41459a305230SLee Schermerhorn } 41469a305230SLee Schermerhorn 41479a305230SLee Schermerhorn /* 41489b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 414910fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 415010fbcf4cSKay Sievers * registered their associated device by this time. 41519a305230SLee Schermerhorn */ 41527d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 41539a305230SLee Schermerhorn { 41549a305230SLee Schermerhorn int nid; 41559a305230SLee Schermerhorn 4156a4a00b45SMuchun Song for_each_online_node(nid) 4157b958d4d0SMuchun Song hugetlb_register_node(node_devices[nid]); 41589a305230SLee Schermerhorn } 41599a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 41609a305230SLee Schermerhorn 41619a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 41629a305230SLee Schermerhorn { 41639a305230SLee Schermerhorn BUG(); 41649a305230SLee Schermerhorn if (nidp) 41659a305230SLee Schermerhorn *nidp = -1; 41669a305230SLee Schermerhorn return NULL; 41679a305230SLee Schermerhorn } 41689a305230SLee Schermerhorn 41699a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 41709a305230SLee Schermerhorn 41719a305230SLee Schermerhorn #endif 41729a305230SLee Schermerhorn 4173263b8998SMiaohe Lin #ifdef CONFIG_CMA 4174263b8998SMiaohe Lin static void __init hugetlb_cma_check(void); 4175263b8998SMiaohe Lin #else 4176263b8998SMiaohe Lin static inline __init void hugetlb_cma_check(void) 4177263b8998SMiaohe Lin { 4178263b8998SMiaohe Lin } 4179263b8998SMiaohe Lin #endif 4180263b8998SMiaohe Lin 4181a4a00b45SMuchun Song static void __init hugetlb_sysfs_init(void) 4182a4a00b45SMuchun Song { 4183a4a00b45SMuchun Song struct hstate *h; 4184a4a00b45SMuchun Song int err; 4185a4a00b45SMuchun Song 4186a4a00b45SMuchun Song hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 4187a4a00b45SMuchun Song if (!hugepages_kobj) 4188a4a00b45SMuchun Song return; 4189a4a00b45SMuchun Song 4190a4a00b45SMuchun Song for_each_hstate(h) { 4191a4a00b45SMuchun Song err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 4192a4a00b45SMuchun Song hstate_kobjs, &hstate_attr_group); 4193a4a00b45SMuchun Song if (err) 4194a4a00b45SMuchun Song pr_err("HugeTLB: Unable to add hstate %s", h->name); 4195a4a00b45SMuchun Song } 4196a4a00b45SMuchun Song 4197a4a00b45SMuchun Song #ifdef CONFIG_NUMA 4198a4a00b45SMuchun Song hugetlb_sysfs_initialized = true; 4199a4a00b45SMuchun Song #endif 4200a4a00b45SMuchun Song hugetlb_register_all_nodes(); 4201a4a00b45SMuchun Song } 4202a4a00b45SMuchun Song 4203a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 4204a3437870SNishanth Aravamudan { 42058382d914SDavidlohr Bueso int i; 42068382d914SDavidlohr Bueso 4207d6995da3SMike Kravetz BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < 4208d6995da3SMike Kravetz __NR_HPAGEFLAGS); 4209d6995da3SMike Kravetz 4210c2833a5bSMike Kravetz if (!hugepages_supported()) { 4211c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 4212c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 42130ef89d25SBenjamin Herrenschmidt return 0; 4214d715cf80SLiam R. Howlett } 4215d715cf80SLiam R. Howlett 4216282f4214SMike Kravetz /* 4217282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 4218282f4214SMike Kravetz * architectures depend on setup being done here. 4219282f4214SMike Kravetz */ 4220a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 4221282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 4222282f4214SMike Kravetz /* 4223282f4214SMike Kravetz * If we did not parse a default huge page size, set 4224282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 4225282f4214SMike Kravetz * number of huge pages for this default size was implicitly 4226282f4214SMike Kravetz * specified, set that here as well. 4227282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 4228282f4214SMike Kravetz * setting. A warning will be printed in this case. 4229282f4214SMike Kravetz */ 4230282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 4231f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 4232282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 4233282f4214SMike Kravetz char buf[32]; 4234282f4214SMike Kravetz 4235282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 4236282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 4237282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 4238282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 4239282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 4240282f4214SMike Kravetz default_hstate_max_huge_pages); 4241282f4214SMike Kravetz } 4242282f4214SMike Kravetz default_hstate.max_huge_pages = 4243282f4214SMike Kravetz default_hstate_max_huge_pages; 4244b5389086SZhenguo Yao 42450a7a0f6fSPeng Liu for_each_online_node(i) 4246b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4247b5389086SZhenguo Yao default_hugepages_in_node[i]; 4248282f4214SMike Kravetz } 4249f8b74815SVaishali Thakkar } 4250a3437870SNishanth Aravamudan 4251cf11e85fSRoman Gushchin hugetlb_cma_check(); 4252a3437870SNishanth Aravamudan hugetlb_init_hstates(); 4253aa888a74SAndi Kleen gather_bootmem_prealloc(); 4254a3437870SNishanth Aravamudan report_hugepages(); 4255a3437870SNishanth Aravamudan 4256a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 42577179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 42589a305230SLee Schermerhorn 42598382d914SDavidlohr Bueso #ifdef CONFIG_SMP 42608382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 42618382d914SDavidlohr Bueso #else 42628382d914SDavidlohr Bueso num_fault_mutexes = 1; 42638382d914SDavidlohr Bueso #endif 4264c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 42656da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 42666da2ec56SKees Cook GFP_KERNEL); 4267c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 42688382d914SDavidlohr Bueso 42698382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 4270c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 4271a3437870SNishanth Aravamudan return 0; 4272a3437870SNishanth Aravamudan } 42733e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 4274a3437870SNishanth Aravamudan 4275ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 4276ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 42779fee021dSVaishali Thakkar { 4278ae94da89SMike Kravetz return size == HPAGE_SIZE; 42799fee021dSVaishali Thakkar } 42809fee021dSVaishali Thakkar 4281d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 4282a3437870SNishanth Aravamudan { 4283a3437870SNishanth Aravamudan struct hstate *h; 42848faa8b07SAndi Kleen unsigned long i; 42858faa8b07SAndi Kleen 4286a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 4287a3437870SNishanth Aravamudan return; 4288a3437870SNishanth Aravamudan } 428947d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 4290a3437870SNishanth Aravamudan BUG_ON(order == 0); 429147d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 429229383967SMike Kravetz mutex_init(&h->resize_lock); 4293a3437870SNishanth Aravamudan h->order = order; 4294aca78307SMiaohe Lin h->mask = ~(huge_page_size(h) - 1); 42958faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 42968faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 42970edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 429854f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 429954f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 4300a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 4301c2c3a60aSMiaohe Lin huge_page_size(h)/SZ_1K); 43028faa8b07SAndi Kleen 4303a3437870SNishanth Aravamudan parsed_hstate = h; 4304a3437870SNishanth Aravamudan } 4305a3437870SNishanth Aravamudan 4306b5389086SZhenguo Yao bool __init __weak hugetlb_node_alloc_supported(void) 4307b5389086SZhenguo Yao { 4308b5389086SZhenguo Yao return true; 4309b5389086SZhenguo Yao } 4310f87442f4SPeng Liu 4311f87442f4SPeng Liu static void __init hugepages_clear_pages_in_node(void) 4312f87442f4SPeng Liu { 4313f87442f4SPeng Liu if (!hugetlb_max_hstate) { 4314f87442f4SPeng Liu default_hstate_max_huge_pages = 0; 4315f87442f4SPeng Liu memset(default_hugepages_in_node, 0, 431610395680SMiaohe Lin sizeof(default_hugepages_in_node)); 4317f87442f4SPeng Liu } else { 4318f87442f4SPeng Liu parsed_hstate->max_huge_pages = 0; 4319f87442f4SPeng Liu memset(parsed_hstate->max_huge_pages_node, 0, 432010395680SMiaohe Lin sizeof(parsed_hstate->max_huge_pages_node)); 4321f87442f4SPeng Liu } 4322f87442f4SPeng Liu } 4323f87442f4SPeng Liu 4324282f4214SMike Kravetz /* 4325282f4214SMike Kravetz * hugepages command line processing 4326282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 4327282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 4328282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 4329282f4214SMike Kravetz * specifies the number of huge pages for the default size. 4330282f4214SMike Kravetz */ 4331282f4214SMike Kravetz static int __init hugepages_setup(char *s) 4332a3437870SNishanth Aravamudan { 4333a3437870SNishanth Aravamudan unsigned long *mhp; 43348faa8b07SAndi Kleen static unsigned long *last_mhp; 4335b5389086SZhenguo Yao int node = NUMA_NO_NODE; 4336b5389086SZhenguo Yao int count; 4337b5389086SZhenguo Yao unsigned long tmp; 4338b5389086SZhenguo Yao char *p = s; 4339a3437870SNishanth Aravamudan 43409fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 4341282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 43429fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 4343f81f6e4bSPeng Liu return 1; 43449fee021dSVaishali Thakkar } 4345282f4214SMike Kravetz 4346a3437870SNishanth Aravamudan /* 4347282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 4348282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 4349282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 4350282f4214SMike Kravetz * default_hugepagesz. 4351a3437870SNishanth Aravamudan */ 43529fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 4353a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 4354a3437870SNishanth Aravamudan else 4355a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 4356a3437870SNishanth Aravamudan 43578faa8b07SAndi Kleen if (mhp == last_mhp) { 4358282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 4359f81f6e4bSPeng Liu return 1; 43608faa8b07SAndi Kleen } 43618faa8b07SAndi Kleen 4362b5389086SZhenguo Yao while (*p) { 4363b5389086SZhenguo Yao count = 0; 4364b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4365b5389086SZhenguo Yao goto invalid; 4366b5389086SZhenguo Yao /* Parameter is node format */ 4367b5389086SZhenguo Yao if (p[count] == ':') { 4368b5389086SZhenguo Yao if (!hugetlb_node_alloc_supported()) { 4369b5389086SZhenguo Yao pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); 4370f81f6e4bSPeng Liu return 1; 4371b5389086SZhenguo Yao } 43720a7a0f6fSPeng Liu if (tmp >= MAX_NUMNODES || !node_online(tmp)) 4373e79ce983SLiu Yuntao goto invalid; 43740a7a0f6fSPeng Liu node = array_index_nospec(tmp, MAX_NUMNODES); 4375b5389086SZhenguo Yao p += count + 1; 4376b5389086SZhenguo Yao /* Parse hugepages */ 4377b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4378b5389086SZhenguo Yao goto invalid; 4379b5389086SZhenguo Yao if (!hugetlb_max_hstate) 4380b5389086SZhenguo Yao default_hugepages_in_node[node] = tmp; 4381b5389086SZhenguo Yao else 4382b5389086SZhenguo Yao parsed_hstate->max_huge_pages_node[node] = tmp; 4383b5389086SZhenguo Yao *mhp += tmp; 4384b5389086SZhenguo Yao /* Go to parse next node*/ 4385b5389086SZhenguo Yao if (p[count] == ',') 4386b5389086SZhenguo Yao p += count + 1; 4387b5389086SZhenguo Yao else 4388b5389086SZhenguo Yao break; 4389b5389086SZhenguo Yao } else { 4390b5389086SZhenguo Yao if (p != s) 4391b5389086SZhenguo Yao goto invalid; 4392b5389086SZhenguo Yao *mhp = tmp; 4393b5389086SZhenguo Yao break; 4394b5389086SZhenguo Yao } 4395b5389086SZhenguo Yao } 4396a3437870SNishanth Aravamudan 43978faa8b07SAndi Kleen /* 43988faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 439904adbc3fSMiaohe Lin * But we need to allocate gigantic hstates here early to still 44008faa8b07SAndi Kleen * use the bootmem allocator. 44018faa8b07SAndi Kleen */ 440204adbc3fSMiaohe Lin if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate)) 44038faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 44048faa8b07SAndi Kleen 44058faa8b07SAndi Kleen last_mhp = mhp; 44068faa8b07SAndi Kleen 4407a3437870SNishanth Aravamudan return 1; 4408b5389086SZhenguo Yao 4409b5389086SZhenguo Yao invalid: 4410b5389086SZhenguo Yao pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p); 4411f87442f4SPeng Liu hugepages_clear_pages_in_node(); 4412f81f6e4bSPeng Liu return 1; 4413a3437870SNishanth Aravamudan } 4414282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 4415e11bfbfcSNick Piggin 4416282f4214SMike Kravetz /* 4417282f4214SMike Kravetz * hugepagesz command line processing 4418282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 4419282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 4420282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 4421282f4214SMike Kravetz * hugepagesz argument was valid. 4422282f4214SMike Kravetz */ 4423359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 4424e11bfbfcSNick Piggin { 4425359f2544SMike Kravetz unsigned long size; 4426282f4214SMike Kravetz struct hstate *h; 4427282f4214SMike Kravetz 4428282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4429359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 4430359f2544SMike Kravetz 4431359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4432282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 4433f81f6e4bSPeng Liu return 1; 4434359f2544SMike Kravetz } 4435359f2544SMike Kravetz 4436282f4214SMike Kravetz h = size_to_hstate(size); 4437282f4214SMike Kravetz if (h) { 4438282f4214SMike Kravetz /* 4439282f4214SMike Kravetz * hstate for this size already exists. This is normally 4440282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 4441282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 4442282f4214SMike Kravetz * the number of huge pages for the default hstate was not 4443282f4214SMike Kravetz * previously specified. 4444282f4214SMike Kravetz */ 4445282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 4446282f4214SMike Kravetz default_hstate.max_huge_pages) { 4447282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 4448f81f6e4bSPeng Liu return 1; 444938237830SMike Kravetz } 445038237830SMike Kravetz 4451282f4214SMike Kravetz /* 4452282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 4453282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 4454282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 4455282f4214SMike Kravetz */ 4456282f4214SMike Kravetz parsed_hstate = h; 4457282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4458e11bfbfcSNick Piggin return 1; 4459e11bfbfcSNick Piggin } 4460282f4214SMike Kravetz 4461359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4462282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4463359f2544SMike Kravetz return 1; 4464359f2544SMike Kravetz } 4465359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 4466359f2544SMike Kravetz 4467282f4214SMike Kravetz /* 4468282f4214SMike Kravetz * default_hugepagesz command line input 4469282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 4470282f4214SMike Kravetz */ 4471ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 4472e11bfbfcSNick Piggin { 4473ae94da89SMike Kravetz unsigned long size; 4474b5389086SZhenguo Yao int i; 4475ae94da89SMike Kravetz 4476282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4477282f4214SMike Kravetz if (parsed_default_hugepagesz) { 4478282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 4479f81f6e4bSPeng Liu return 1; 4480282f4214SMike Kravetz } 4481282f4214SMike Kravetz 4482282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 4483282f4214SMike Kravetz 4484282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4485282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 4486f81f6e4bSPeng Liu return 1; 4487282f4214SMike Kravetz } 4488282f4214SMike Kravetz 4489282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4490282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4491282f4214SMike Kravetz parsed_default_hugepagesz = true; 4492282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 4493282f4214SMike Kravetz 4494282f4214SMike Kravetz /* 4495282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 4496282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 4497282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 4498282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 4499282f4214SMike Kravetz * allocated here from bootmem allocator. 4500282f4214SMike Kravetz */ 4501282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 4502282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 45030a7a0f6fSPeng Liu for_each_online_node(i) 4504b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4505b5389086SZhenguo Yao default_hugepages_in_node[i]; 4506282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 4507282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 4508282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 4509282f4214SMike Kravetz } 4510282f4214SMike Kravetz 4511e11bfbfcSNick Piggin return 1; 4512e11bfbfcSNick Piggin } 4513ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 4514a3437870SNishanth Aravamudan 4515d2226ebdSFeng Tang static nodemask_t *policy_mbind_nodemask(gfp_t gfp) 4516d2226ebdSFeng Tang { 4517d2226ebdSFeng Tang #ifdef CONFIG_NUMA 4518d2226ebdSFeng Tang struct mempolicy *mpol = get_task_policy(current); 4519d2226ebdSFeng Tang 4520d2226ebdSFeng Tang /* 4521d2226ebdSFeng Tang * Only enforce MPOL_BIND policy which overlaps with cpuset policy 4522d2226ebdSFeng Tang * (from policy_nodemask) specifically for hugetlb case 4523d2226ebdSFeng Tang */ 4524d2226ebdSFeng Tang if (mpol->mode == MPOL_BIND && 4525d2226ebdSFeng Tang (apply_policy_zone(mpol, gfp_zone(gfp)) && 4526d2226ebdSFeng Tang cpuset_nodemask_valid_mems_allowed(&mpol->nodes))) 4527d2226ebdSFeng Tang return &mpol->nodes; 4528d2226ebdSFeng Tang #endif 4529d2226ebdSFeng Tang return NULL; 4530d2226ebdSFeng Tang } 4531d2226ebdSFeng Tang 45328ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 45338a213460SNishanth Aravamudan { 45348a213460SNishanth Aravamudan int node; 45358a213460SNishanth Aravamudan unsigned int nr = 0; 4536d2226ebdSFeng Tang nodemask_t *mbind_nodemask; 45378ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 45388ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 45398a213460SNishanth Aravamudan 4540d2226ebdSFeng Tang mbind_nodemask = policy_mbind_nodemask(gfp_mask); 45418ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 4542d2226ebdSFeng Tang if (!mbind_nodemask || node_isset(node, *mbind_nodemask)) 45438a213460SNishanth Aravamudan nr += array[node]; 45448ca39e68SMuchun Song } 45458a213460SNishanth Aravamudan 45468a213460SNishanth Aravamudan return nr; 45478a213460SNishanth Aravamudan } 45488a213460SNishanth Aravamudan 45498a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 455017743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 455117743798SMuchun Song void *buffer, size_t *length, 455217743798SMuchun Song loff_t *ppos, unsigned long *out) 455317743798SMuchun Song { 455417743798SMuchun Song struct ctl_table dup_table; 455517743798SMuchun Song 455617743798SMuchun Song /* 455717743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 455817743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 455917743798SMuchun Song */ 456017743798SMuchun Song dup_table = *table; 456117743798SMuchun Song dup_table.data = out; 456217743798SMuchun Song 456317743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 456417743798SMuchun Song } 456517743798SMuchun Song 456606808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 456706808b08SLee Schermerhorn struct ctl_table *table, int write, 456832927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 45691da177e4SLinus Torvalds { 4570e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 4571238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 457208d4a246SMichal Hocko int ret; 4573e5ff2159SAndi Kleen 4574457c1b27SNishanth Aravamudan if (!hugepages_supported()) 457586613628SJan Stancek return -EOPNOTSUPP; 4576457c1b27SNishanth Aravamudan 457717743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 457817743798SMuchun Song &tmp); 457908d4a246SMichal Hocko if (ret) 458008d4a246SMichal Hocko goto out; 4581e5ff2159SAndi Kleen 4582238d3c13SDavid Rientjes if (write) 4583238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 4584238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 458508d4a246SMichal Hocko out: 458608d4a246SMichal Hocko return ret; 45871da177e4SLinus Torvalds } 4588396faf03SMel Gorman 458906808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 459032927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 459106808b08SLee Schermerhorn { 459206808b08SLee Schermerhorn 459306808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 459406808b08SLee Schermerhorn buffer, length, ppos); 459506808b08SLee Schermerhorn } 459606808b08SLee Schermerhorn 459706808b08SLee Schermerhorn #ifdef CONFIG_NUMA 459806808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 459932927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 460006808b08SLee Schermerhorn { 460106808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 460206808b08SLee Schermerhorn buffer, length, ppos); 460306808b08SLee Schermerhorn } 460406808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 460506808b08SLee Schermerhorn 4606a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 460732927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 4608a3d0c6aaSNishanth Aravamudan { 4609a5516438SAndi Kleen struct hstate *h = &default_hstate; 4610e5ff2159SAndi Kleen unsigned long tmp; 461108d4a246SMichal Hocko int ret; 4612e5ff2159SAndi Kleen 4613457c1b27SNishanth Aravamudan if (!hugepages_supported()) 461486613628SJan Stancek return -EOPNOTSUPP; 4615457c1b27SNishanth Aravamudan 4616e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 4617e5ff2159SAndi Kleen 4618bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 4619adbe8726SEric B Munson return -EINVAL; 4620adbe8726SEric B Munson 462117743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 462217743798SMuchun Song &tmp); 462308d4a246SMichal Hocko if (ret) 462408d4a246SMichal Hocko goto out; 4625e5ff2159SAndi Kleen 4626e5ff2159SAndi Kleen if (write) { 4627db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4628e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 4629db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4630e5ff2159SAndi Kleen } 463108d4a246SMichal Hocko out: 463208d4a246SMichal Hocko return ret; 4633a3d0c6aaSNishanth Aravamudan } 4634a3d0c6aaSNishanth Aravamudan 46351da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 46361da177e4SLinus Torvalds 4637e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 46381da177e4SLinus Torvalds { 4639fcb2b0c5SRoman Gushchin struct hstate *h; 4640fcb2b0c5SRoman Gushchin unsigned long total = 0; 4641fcb2b0c5SRoman Gushchin 4642457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4643457c1b27SNishanth Aravamudan return; 4644fcb2b0c5SRoman Gushchin 4645fcb2b0c5SRoman Gushchin for_each_hstate(h) { 4646fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 4647fcb2b0c5SRoman Gushchin 4648aca78307SMiaohe Lin total += huge_page_size(h) * count; 4649fcb2b0c5SRoman Gushchin 4650fcb2b0c5SRoman Gushchin if (h == &default_hstate) 4651e1759c21SAlexey Dobriyan seq_printf(m, 46521da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 46531da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 4654b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 46557893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 46564f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 4657fcb2b0c5SRoman Gushchin count, 4658a5516438SAndi Kleen h->free_huge_pages, 4659a5516438SAndi Kleen h->resv_huge_pages, 4660a5516438SAndi Kleen h->surplus_huge_pages, 4661aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4662fcb2b0c5SRoman Gushchin } 4663fcb2b0c5SRoman Gushchin 4664aca78307SMiaohe Lin seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K); 46651da177e4SLinus Torvalds } 46661da177e4SLinus Torvalds 46677981593bSJoe Perches int hugetlb_report_node_meminfo(char *buf, int len, int nid) 46681da177e4SLinus Torvalds { 4669a5516438SAndi Kleen struct hstate *h = &default_hstate; 46707981593bSJoe Perches 4671457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4672457c1b27SNishanth Aravamudan return 0; 46737981593bSJoe Perches 46747981593bSJoe Perches return sysfs_emit_at(buf, len, 46751da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 4676a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 4677a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 4678a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 4679a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 4680a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 46811da177e4SLinus Torvalds } 46821da177e4SLinus Torvalds 4683dcadcf1cSGang Li void hugetlb_show_meminfo_node(int nid) 4684949f7ec5SDavid Rientjes { 4685949f7ec5SDavid Rientjes struct hstate *h; 4686949f7ec5SDavid Rientjes 4687457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4688457c1b27SNishanth Aravamudan return; 4689457c1b27SNishanth Aravamudan 4690949f7ec5SDavid Rientjes for_each_hstate(h) 4691dcadcf1cSGang Li printk("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 4692949f7ec5SDavid Rientjes nid, 4693949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 4694949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 4695949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 4696aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4697949f7ec5SDavid Rientjes } 4698949f7ec5SDavid Rientjes 46995d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 47005d317b2bSNaoya Horiguchi { 47015d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 47025d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 47035d317b2bSNaoya Horiguchi } 47045d317b2bSNaoya Horiguchi 47051da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 47061da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 47071da177e4SLinus Torvalds { 4708d0028588SWanpeng Li struct hstate *h; 4709d0028588SWanpeng Li unsigned long nr_total_pages = 0; 4710d0028588SWanpeng Li 4711d0028588SWanpeng Li for_each_hstate(h) 4712d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 4713d0028588SWanpeng Li return nr_total_pages; 47141da177e4SLinus Torvalds } 47151da177e4SLinus Torvalds 4716a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 4717fc1b8a73SMel Gorman { 4718fc1b8a73SMel Gorman int ret = -ENOMEM; 4719fc1b8a73SMel Gorman 47200aa7f354SMiaohe Lin if (!delta) 47210aa7f354SMiaohe Lin return 0; 47220aa7f354SMiaohe Lin 4723db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4724fc1b8a73SMel Gorman /* 4725fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 4726fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 4727fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 4728fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 4729fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 4730fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 4731fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 4732fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 4733fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 4734fc1b8a73SMel Gorman * 4735fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 4736fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 4737fc1b8a73SMel Gorman * we fall back to check against current free page availability as 4738fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 4739fc1b8a73SMel Gorman * semantics that cpuset has. 47408ca39e68SMuchun Song * 47418ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 47428ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 47438ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 47448ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 47458ca39e68SMuchun Song * above. 4746fc1b8a73SMel Gorman */ 4747fc1b8a73SMel Gorman if (delta > 0) { 4748a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 4749fc1b8a73SMel Gorman goto out; 4750fc1b8a73SMel Gorman 47518ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 4752a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 4753fc1b8a73SMel Gorman goto out; 4754fc1b8a73SMel Gorman } 4755fc1b8a73SMel Gorman } 4756fc1b8a73SMel Gorman 4757fc1b8a73SMel Gorman ret = 0; 4758fc1b8a73SMel Gorman if (delta < 0) 4759a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 4760fc1b8a73SMel Gorman 4761fc1b8a73SMel Gorman out: 4762db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4763fc1b8a73SMel Gorman return ret; 4764fc1b8a73SMel Gorman } 4765fc1b8a73SMel Gorman 476684afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 476784afd99bSAndy Whitcroft { 4768f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 476984afd99bSAndy Whitcroft 477084afd99bSAndy Whitcroft /* 4771612b8a31SMike Kravetz * HPAGE_RESV_OWNER indicates a private mapping. 477284afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 477384afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 477484afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 477525985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 477684afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 477784afd99bSAndy Whitcroft * new reference here without additional locking. 477884afd99bSAndy Whitcroft */ 477909a26e83SMike Kravetz if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 478009a26e83SMike Kravetz resv_map_dup_hugetlb_cgroup_uncharge_info(resv); 4781f522c3acSJoonsoo Kim kref_get(&resv->refs); 478284afd99bSAndy Whitcroft } 47838d9bfb26SMike Kravetz 4784131a79b4SMike Kravetz /* 4785131a79b4SMike Kravetz * vma_lock structure for sharable mappings is vma specific. 4786612b8a31SMike Kravetz * Clear old pointer (if copied via vm_area_dup) and allocate 4787612b8a31SMike Kravetz * new structure. Before clearing, make sure vma_lock is not 4788612b8a31SMike Kravetz * for this vma. 4789131a79b4SMike Kravetz */ 4790131a79b4SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 4791612b8a31SMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 4792612b8a31SMike Kravetz 4793612b8a31SMike Kravetz if (vma_lock) { 4794612b8a31SMike Kravetz if (vma_lock->vma != vma) { 4795131a79b4SMike Kravetz vma->vm_private_data = NULL; 47968d9bfb26SMike Kravetz hugetlb_vma_lock_alloc(vma); 4797612b8a31SMike Kravetz } else 4798612b8a31SMike Kravetz pr_warn("HugeTLB: vma_lock already exists in %s.\n", __func__); 4799612b8a31SMike Kravetz } else 4800612b8a31SMike Kravetz hugetlb_vma_lock_alloc(vma); 480109a26e83SMike Kravetz } 4802131a79b4SMike Kravetz } 480384afd99bSAndy Whitcroft 4804a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 4805a1e78772SMel Gorman { 4806a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 48078d9bfb26SMike Kravetz struct resv_map *resv; 480890481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 48094e35f483SJoonsoo Kim unsigned long reserve, start, end; 48101c5ecae3SMike Kravetz long gbl_reserve; 481184afd99bSAndy Whitcroft 48128d9bfb26SMike Kravetz hugetlb_vma_lock_free(vma); 48138d9bfb26SMike Kravetz 48148d9bfb26SMike Kravetz resv = vma_resv_map(vma); 48154e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 48164e35f483SJoonsoo Kim return; 48174e35f483SJoonsoo Kim 4818a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 4819a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 482084afd99bSAndy Whitcroft 48214e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 4822e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 48237251ff78SAdam Litke if (reserve) { 48241c5ecae3SMike Kravetz /* 48251c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 48261c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 48271c5ecae3SMike Kravetz */ 48281c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 48291c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 48307251ff78SAdam Litke } 4831e9fe92aeSMina Almasry 4832e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 4833a1e78772SMel Gorman } 4834a1e78772SMel Gorman 483531383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 483631383c68SDan Williams { 483731383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 483831383c68SDan Williams return -EINVAL; 4839b30c14cdSJames Houghton 4840b30c14cdSJames Houghton /* 4841b30c14cdSJames Houghton * PMD sharing is only possible for PUD_SIZE-aligned address ranges 4842b30c14cdSJames Houghton * in HugeTLB VMAs. If we will lose PUD_SIZE alignment due to this 4843b30c14cdSJames Houghton * split, unshare PMDs in the PUD_SIZE interval surrounding addr now. 4844b30c14cdSJames Houghton */ 4845b30c14cdSJames Houghton if (addr & ~PUD_MASK) { 4846b30c14cdSJames Houghton /* 4847b30c14cdSJames Houghton * hugetlb_vm_op_split is called right before we attempt to 4848b30c14cdSJames Houghton * split the VMA. We will need to unshare PMDs in the old and 4849b30c14cdSJames Houghton * new VMAs, so let's unshare before we split. 4850b30c14cdSJames Houghton */ 4851b30c14cdSJames Houghton unsigned long floor = addr & PUD_MASK; 4852b30c14cdSJames Houghton unsigned long ceil = floor + PUD_SIZE; 4853b30c14cdSJames Houghton 4854b30c14cdSJames Houghton if (floor >= vma->vm_start && ceil <= vma->vm_end) 4855b30c14cdSJames Houghton hugetlb_unshare_pmds(vma, floor, ceil); 4856b30c14cdSJames Houghton } 4857b30c14cdSJames Houghton 485831383c68SDan Williams return 0; 485931383c68SDan Williams } 486031383c68SDan Williams 486105ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 486205ea8860SDan Williams { 4863aca78307SMiaohe Lin return huge_page_size(hstate_vma(vma)); 486405ea8860SDan Williams } 486505ea8860SDan Williams 48661da177e4SLinus Torvalds /* 48671da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 48681da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 48696c26d310SMiaohe Lin * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get 48701da177e4SLinus Torvalds * this far. 48711da177e4SLinus Torvalds */ 4872b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 48731da177e4SLinus Torvalds { 48741da177e4SLinus Torvalds BUG(); 4875d0217ac0SNick Piggin return 0; 48761da177e4SLinus Torvalds } 48771da177e4SLinus Torvalds 4878eec3636aSJane Chu /* 4879eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 4880eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 4881eec3636aSJane Chu * This is because under System V memory model, mappings created via 4882eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 4883eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 4884eec3636aSJane Chu */ 4885f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 4886d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 488784afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 4888a1e78772SMel Gorman .close = hugetlb_vm_op_close, 4889dd3b614fSDmitry Safonov .may_split = hugetlb_vm_op_split, 489005ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 48911da177e4SLinus Torvalds }; 48921da177e4SLinus Torvalds 48931e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 48941e8f889bSDavid Gibson int writable) 489563551ae0SDavid Gibson { 489663551ae0SDavid Gibson pte_t entry; 489779c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 489863551ae0SDavid Gibson 48991e8f889bSDavid Gibson if (writable) { 4900106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 4901106c992aSGerald Schaefer vma->vm_page_prot))); 490263551ae0SDavid Gibson } else { 4903106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 4904106c992aSGerald Schaefer vma->vm_page_prot)); 490563551ae0SDavid Gibson } 490663551ae0SDavid Gibson entry = pte_mkyoung(entry); 490779c1c594SChristophe Leroy entry = arch_make_huge_pte(entry, shift, vma->vm_flags); 490863551ae0SDavid Gibson 490963551ae0SDavid Gibson return entry; 491063551ae0SDavid Gibson } 491163551ae0SDavid Gibson 49121e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 49131e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 49141e8f889bSDavid Gibson { 49151e8f889bSDavid Gibson pte_t entry; 49161e8f889bSDavid Gibson 4917106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 491832f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 49194b3073e1SRussell King update_mmu_cache(vma, address, ptep); 49201e8f889bSDavid Gibson } 49211e8f889bSDavid Gibson 4922d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 49234a705fefSNaoya Horiguchi { 49244a705fefSNaoya Horiguchi swp_entry_t swp; 49254a705fefSNaoya Horiguchi 49264a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 4927d5ed7444SAneesh Kumar K.V return false; 49284a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4929d79d176aSBaoquan He if (is_migration_entry(swp)) 4930d5ed7444SAneesh Kumar K.V return true; 49314a705fefSNaoya Horiguchi else 4932d5ed7444SAneesh Kumar K.V return false; 49334a705fefSNaoya Horiguchi } 49344a705fefSNaoya Horiguchi 49353e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 49364a705fefSNaoya Horiguchi { 49374a705fefSNaoya Horiguchi swp_entry_t swp; 49384a705fefSNaoya Horiguchi 49394a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 49403e5c3600SBaoquan He return false; 49414a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4942d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 49433e5c3600SBaoquan He return true; 49444a705fefSNaoya Horiguchi else 49453e5c3600SBaoquan He return false; 49464a705fefSNaoya Horiguchi } 49471e8f889bSDavid Gibson 49484eae4efaSPeter Xu static void 49494eae4efaSPeter Xu hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr, 49504eae4efaSPeter Xu struct page *new_page) 49514eae4efaSPeter Xu { 49524eae4efaSPeter Xu __SetPageUptodate(new_page); 49534eae4efaSPeter Xu hugepage_add_new_anon_rmap(new_page, vma, addr); 49541eba86c0SPasha Tatashin set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1)); 49554eae4efaSPeter Xu hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm); 49564eae4efaSPeter Xu SetHPageMigratable(new_page); 49574eae4efaSPeter Xu } 49584eae4efaSPeter Xu 495963551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 4960bc70fbf2SPeter Xu struct vm_area_struct *dst_vma, 4961bc70fbf2SPeter Xu struct vm_area_struct *src_vma) 496263551ae0SDavid Gibson { 49633aa4ed80SMiaohe Lin pte_t *src_pte, *dst_pte, entry; 496463551ae0SDavid Gibson struct page *ptepage; 49651c59827dSHugh Dickins unsigned long addr; 4966bc70fbf2SPeter Xu bool cow = is_cow_mapping(src_vma->vm_flags); 4967bc70fbf2SPeter Xu struct hstate *h = hstate_vma(src_vma); 4968a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 49694eae4efaSPeter Xu unsigned long npages = pages_per_huge_page(h); 4970ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4971e95a9851SMike Kravetz unsigned long last_addr_mask; 4972e8569dd2SAndreas Sandberg int ret = 0; 49731e8f889bSDavid Gibson 4974ac46d4f3SJérôme Glisse if (cow) { 4975bc70fbf2SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, src_vma, src, 4976bc70fbf2SPeter Xu src_vma->vm_start, 4977bc70fbf2SPeter Xu src_vma->vm_end); 4978ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4979623a1ddfSDavid Hildenbrand mmap_assert_write_locked(src); 4980623a1ddfSDavid Hildenbrand raw_write_seqcount_begin(&src->write_protect_seq); 498140549ba8SMike Kravetz } else { 498240549ba8SMike Kravetz /* 498340549ba8SMike Kravetz * For shared mappings the vma lock must be held before 498440549ba8SMike Kravetz * calling huge_pte_offset in the src vma. Otherwise, the 498540549ba8SMike Kravetz * returned ptep could go away if part of a shared pmd and 498640549ba8SMike Kravetz * another thread calls huge_pmd_unshare. 498740549ba8SMike Kravetz */ 498840549ba8SMike Kravetz hugetlb_vma_lock_read(src_vma); 4989ac46d4f3SJérôme Glisse } 4990e8569dd2SAndreas Sandberg 4991e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 4992bc70fbf2SPeter Xu for (addr = src_vma->vm_start; addr < src_vma->vm_end; addr += sz) { 4993cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 49947868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 4995e95a9851SMike Kravetz if (!src_pte) { 4996e95a9851SMike Kravetz addr |= last_addr_mask; 4997c74df32cSHugh Dickins continue; 4998e95a9851SMike Kravetz } 4999bc70fbf2SPeter Xu dst_pte = huge_pte_alloc(dst, dst_vma, addr, sz); 5000e8569dd2SAndreas Sandberg if (!dst_pte) { 5001e8569dd2SAndreas Sandberg ret = -ENOMEM; 5002e8569dd2SAndreas Sandberg break; 5003e8569dd2SAndreas Sandberg } 5004c5c99429SLarry Woodman 50055e41540cSMike Kravetz /* 50065e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 50075e41540cSMike Kravetz * 50083aa4ed80SMiaohe Lin * dst_pte == src_pte is the common case of src/dest sharing. 50095e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 50103aa4ed80SMiaohe Lin * another vma. So page_count of ptep page is checked instead 50113aa4ed80SMiaohe Lin * to reliably determine whether pte is shared. 50125e41540cSMike Kravetz */ 50133aa4ed80SMiaohe Lin if (page_count(virt_to_page(dst_pte)) > 1) { 5014e95a9851SMike Kravetz addr |= last_addr_mask; 5015c5c99429SLarry Woodman continue; 5016e95a9851SMike Kravetz } 5017c5c99429SLarry Woodman 5018cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 5019cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 5020cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 50214a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 50224eae4efaSPeter Xu again: 50233aa4ed80SMiaohe Lin if (huge_pte_none(entry)) { 50245e41540cSMike Kravetz /* 50253aa4ed80SMiaohe Lin * Skip if src entry none. 50265e41540cSMike Kravetz */ 50274a705fefSNaoya Horiguchi ; 5028c2cb0dccSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) { 5029c2cb0dccSNaoya Horiguchi bool uffd_wp = huge_pte_uffd_wp(entry); 5030c2cb0dccSNaoya Horiguchi 5031c2cb0dccSNaoya Horiguchi if (!userfaultfd_wp(dst_vma) && uffd_wp) 5032c2cb0dccSNaoya Horiguchi entry = huge_pte_clear_uffd_wp(entry); 5033c2cb0dccSNaoya Horiguchi set_huge_pte_at(dst, addr, dst_pte, entry); 5034c2cb0dccSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry))) { 50354a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 5036bc70fbf2SPeter Xu bool uffd_wp = huge_pte_uffd_wp(entry); 50374a705fefSNaoya Horiguchi 50386c287605SDavid Hildenbrand if (!is_readable_migration_entry(swp_entry) && cow) { 50394a705fefSNaoya Horiguchi /* 50404a705fefSNaoya Horiguchi * COW mappings require pages in both 50414a705fefSNaoya Horiguchi * parent and child to be set to read. 50424a705fefSNaoya Horiguchi */ 50434dd845b5SAlistair Popple swp_entry = make_readable_migration_entry( 50444dd845b5SAlistair Popple swp_offset(swp_entry)); 50454a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 5046bc70fbf2SPeter Xu if (userfaultfd_wp(src_vma) && uffd_wp) 5047bc70fbf2SPeter Xu entry = huge_pte_mkuffd_wp(entry); 504818f39629SQi Zheng set_huge_pte_at(src, addr, src_pte, entry); 50494a705fefSNaoya Horiguchi } 5050bc70fbf2SPeter Xu if (!userfaultfd_wp(dst_vma) && uffd_wp) 5051bc70fbf2SPeter Xu entry = huge_pte_clear_uffd_wp(entry); 505218f39629SQi Zheng set_huge_pte_at(dst, addr, dst_pte, entry); 5053bc70fbf2SPeter Xu } else if (unlikely(is_pte_marker(entry))) { 5054bc70fbf2SPeter Xu /* 5055bc70fbf2SPeter Xu * We copy the pte marker only if the dst vma has 5056bc70fbf2SPeter Xu * uffd-wp enabled. 5057bc70fbf2SPeter Xu */ 5058bc70fbf2SPeter Xu if (userfaultfd_wp(dst_vma)) 5059bc70fbf2SPeter Xu set_huge_pte_at(dst, addr, dst_pte, entry); 50604a705fefSNaoya Horiguchi } else { 50614eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 50624eae4efaSPeter Xu ptepage = pte_page(entry); 50634eae4efaSPeter Xu get_page(ptepage); 50644eae4efaSPeter Xu 50654eae4efaSPeter Xu /* 5066fb3d824dSDavid Hildenbrand * Failing to duplicate the anon rmap is a rare case 5067fb3d824dSDavid Hildenbrand * where we see pinned hugetlb pages while they're 5068fb3d824dSDavid Hildenbrand * prone to COW. We need to do the COW earlier during 5069fb3d824dSDavid Hildenbrand * fork. 50704eae4efaSPeter Xu * 50714eae4efaSPeter Xu * When pre-allocating the page or copying data, we 50724eae4efaSPeter Xu * need to be without the pgtable locks since we could 50734eae4efaSPeter Xu * sleep during the process. 50744eae4efaSPeter Xu */ 5075fb3d824dSDavid Hildenbrand if (!PageAnon(ptepage)) { 5076fb3d824dSDavid Hildenbrand page_dup_file_rmap(ptepage, true); 5077bc70fbf2SPeter Xu } else if (page_try_dup_anon_rmap(ptepage, true, 5078bc70fbf2SPeter Xu src_vma)) { 50794eae4efaSPeter Xu pte_t src_pte_old = entry; 50804eae4efaSPeter Xu struct page *new; 50814eae4efaSPeter Xu 50824eae4efaSPeter Xu spin_unlock(src_ptl); 50834eae4efaSPeter Xu spin_unlock(dst_ptl); 50844eae4efaSPeter Xu /* Do not use reserve as it's private owned */ 5085bc70fbf2SPeter Xu new = alloc_huge_page(dst_vma, addr, 1); 50864eae4efaSPeter Xu if (IS_ERR(new)) { 50874eae4efaSPeter Xu put_page(ptepage); 50884eae4efaSPeter Xu ret = PTR_ERR(new); 50894eae4efaSPeter Xu break; 50904eae4efaSPeter Xu } 5091bc70fbf2SPeter Xu copy_user_huge_page(new, ptepage, addr, dst_vma, 50924eae4efaSPeter Xu npages); 50934eae4efaSPeter Xu put_page(ptepage); 50944eae4efaSPeter Xu 50954eae4efaSPeter Xu /* Install the new huge page if src pte stable */ 50964eae4efaSPeter Xu dst_ptl = huge_pte_lock(h, dst, dst_pte); 50974eae4efaSPeter Xu src_ptl = huge_pte_lockptr(h, src, src_pte); 50984eae4efaSPeter Xu spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 50994eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 51004eae4efaSPeter Xu if (!pte_same(src_pte_old, entry)) { 5101bc70fbf2SPeter Xu restore_reserve_on_error(h, dst_vma, addr, 5102846be085SMike Kravetz new); 51034eae4efaSPeter Xu put_page(new); 51043aa4ed80SMiaohe Lin /* huge_ptep of dst_pte won't change as in child */ 51054eae4efaSPeter Xu goto again; 51064eae4efaSPeter Xu } 5107bc70fbf2SPeter Xu hugetlb_install_page(dst_vma, dst_pte, addr, new); 51084eae4efaSPeter Xu spin_unlock(src_ptl); 51094eae4efaSPeter Xu spin_unlock(dst_ptl); 51104eae4efaSPeter Xu continue; 51114eae4efaSPeter Xu } 51124eae4efaSPeter Xu 511334ee645eSJoerg Roedel if (cow) { 51140f10851eSJérôme Glisse /* 51150f10851eSJérôme Glisse * No need to notify as we are downgrading page 51160f10851eSJérôme Glisse * table protection not changing it to point 51170f10851eSJérôme Glisse * to a new page. 51180f10851eSJérôme Glisse * 5119ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 51200f10851eSJérôme Glisse */ 51217f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 512284894e1cSPeter Xu entry = huge_pte_wrprotect(entry); 512334ee645eSJoerg Roedel } 51244eae4efaSPeter Xu 512563551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 51264eae4efaSPeter Xu hugetlb_count_add(npages, dst); 51271c59827dSHugh Dickins } 5128cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 5129cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 513063551ae0SDavid Gibson } 513163551ae0SDavid Gibson 5132623a1ddfSDavid Hildenbrand if (cow) { 5133623a1ddfSDavid Hildenbrand raw_write_seqcount_end(&src->write_protect_seq); 5134ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 513540549ba8SMike Kravetz } else { 513640549ba8SMike Kravetz hugetlb_vma_unlock_read(src_vma); 5137623a1ddfSDavid Hildenbrand } 5138e8569dd2SAndreas Sandberg 5139e8569dd2SAndreas Sandberg return ret; 514063551ae0SDavid Gibson } 514163551ae0SDavid Gibson 5142550a7d60SMina Almasry static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr, 5143db110a99SAneesh Kumar K.V unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte) 5144550a7d60SMina Almasry { 5145550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 5146550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 5147550a7d60SMina Almasry spinlock_t *src_ptl, *dst_ptl; 5148db110a99SAneesh Kumar K.V pte_t pte; 5149550a7d60SMina Almasry 5150550a7d60SMina Almasry dst_ptl = huge_pte_lock(h, mm, dst_pte); 5151550a7d60SMina Almasry src_ptl = huge_pte_lockptr(h, mm, src_pte); 5152550a7d60SMina Almasry 5153550a7d60SMina Almasry /* 5154550a7d60SMina Almasry * We don't have to worry about the ordering of src and dst ptlocks 5155*8651a137SLorenzo Stoakes * because exclusive mmap_lock (or the i_mmap_lock) prevents deadlock. 5156550a7d60SMina Almasry */ 5157550a7d60SMina Almasry if (src_ptl != dst_ptl) 5158550a7d60SMina Almasry spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 5159550a7d60SMina Almasry 5160550a7d60SMina Almasry pte = huge_ptep_get_and_clear(mm, old_addr, src_pte); 5161550a7d60SMina Almasry set_huge_pte_at(mm, new_addr, dst_pte, pte); 5162550a7d60SMina Almasry 5163550a7d60SMina Almasry if (src_ptl != dst_ptl) 5164550a7d60SMina Almasry spin_unlock(src_ptl); 5165550a7d60SMina Almasry spin_unlock(dst_ptl); 5166550a7d60SMina Almasry } 5167550a7d60SMina Almasry 5168550a7d60SMina Almasry int move_hugetlb_page_tables(struct vm_area_struct *vma, 5169550a7d60SMina Almasry struct vm_area_struct *new_vma, 5170550a7d60SMina Almasry unsigned long old_addr, unsigned long new_addr, 5171550a7d60SMina Almasry unsigned long len) 5172550a7d60SMina Almasry { 5173550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 5174550a7d60SMina Almasry struct address_space *mapping = vma->vm_file->f_mapping; 5175550a7d60SMina Almasry unsigned long sz = huge_page_size(h); 5176550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 5177550a7d60SMina Almasry unsigned long old_end = old_addr + len; 5178e95a9851SMike Kravetz unsigned long last_addr_mask; 5179550a7d60SMina Almasry pte_t *src_pte, *dst_pte; 5180550a7d60SMina Almasry struct mmu_notifier_range range; 51813d0b95cdSBaolin Wang bool shared_pmd = false; 5182550a7d60SMina Almasry 5183550a7d60SMina Almasry mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, old_addr, 5184550a7d60SMina Almasry old_end); 5185550a7d60SMina Almasry adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 51863d0b95cdSBaolin Wang /* 51873d0b95cdSBaolin Wang * In case of shared PMDs, we should cover the maximum possible 51883d0b95cdSBaolin Wang * range. 51893d0b95cdSBaolin Wang */ 51903d0b95cdSBaolin Wang flush_cache_range(vma, range.start, range.end); 51913d0b95cdSBaolin Wang 5192550a7d60SMina Almasry mmu_notifier_invalidate_range_start(&range); 5193e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 5194550a7d60SMina Almasry /* Prevent race with file truncation */ 519540549ba8SMike Kravetz hugetlb_vma_lock_write(vma); 5196550a7d60SMina Almasry i_mmap_lock_write(mapping); 5197550a7d60SMina Almasry for (; old_addr < old_end; old_addr += sz, new_addr += sz) { 5198550a7d60SMina Almasry src_pte = huge_pte_offset(mm, old_addr, sz); 5199e95a9851SMike Kravetz if (!src_pte) { 5200e95a9851SMike Kravetz old_addr |= last_addr_mask; 5201e95a9851SMike Kravetz new_addr |= last_addr_mask; 5202550a7d60SMina Almasry continue; 5203e95a9851SMike Kravetz } 5204550a7d60SMina Almasry if (huge_pte_none(huge_ptep_get(src_pte))) 5205550a7d60SMina Almasry continue; 5206550a7d60SMina Almasry 52074ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) { 52083d0b95cdSBaolin Wang shared_pmd = true; 52094ddb4d91SMike Kravetz old_addr |= last_addr_mask; 52104ddb4d91SMike Kravetz new_addr |= last_addr_mask; 5211550a7d60SMina Almasry continue; 52123d0b95cdSBaolin Wang } 5213550a7d60SMina Almasry 5214550a7d60SMina Almasry dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz); 5215550a7d60SMina Almasry if (!dst_pte) 5216550a7d60SMina Almasry break; 5217550a7d60SMina Almasry 5218db110a99SAneesh Kumar K.V move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte); 5219550a7d60SMina Almasry } 52203d0b95cdSBaolin Wang 52213d0b95cdSBaolin Wang if (shared_pmd) 52223d0b95cdSBaolin Wang flush_tlb_range(vma, range.start, range.end); 52233d0b95cdSBaolin Wang else 5224550a7d60SMina Almasry flush_tlb_range(vma, old_end - len, old_end); 5225550a7d60SMina Almasry mmu_notifier_invalidate_range_end(&range); 522613e4ad2cSNadav Amit i_mmap_unlock_write(mapping); 522740549ba8SMike Kravetz hugetlb_vma_unlock_write(vma); 5228550a7d60SMina Almasry 5229550a7d60SMina Almasry return len + old_addr - old_end; 5230550a7d60SMina Almasry } 5231550a7d60SMina Almasry 523273c54763SPeter Xu static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 523324669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 523405e90bd0SPeter Xu struct page *ref_page, zap_flags_t zap_flags) 523563551ae0SDavid Gibson { 523663551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 523763551ae0SDavid Gibson unsigned long address; 5238c7546f8fSDavid Gibson pte_t *ptep; 523963551ae0SDavid Gibson pte_t pte; 5240cb900f41SKirill A. Shutemov spinlock_t *ptl; 524163551ae0SDavid Gibson struct page *page; 5242a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 5243a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 5244e95a9851SMike Kravetz unsigned long last_addr_mask; 5245a4a118f2SNadav Amit bool force_flush = false; 5246a5516438SAndi Kleen 524763551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 5248a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 5249a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 525063551ae0SDavid Gibson 525107e32661SAneesh Kumar K.V /* 525207e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 525307e32661SAneesh Kumar K.V * to huge page. 525407e32661SAneesh Kumar K.V */ 5255ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 525624669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 5257dff11abeSMike Kravetz 5258e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 5259569f48b8SHillf Danton address = start; 5260569f48b8SHillf Danton for (; address < end; address += sz) { 52617868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 5262e95a9851SMike Kravetz if (!ptep) { 5263e95a9851SMike Kravetz address |= last_addr_mask; 5264c7546f8fSDavid Gibson continue; 5265e95a9851SMike Kravetz } 5266c7546f8fSDavid Gibson 5267cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 52684ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, address, ptep)) { 526931d49da5SAneesh Kumar K.V spin_unlock(ptl); 5270a4a118f2SNadav Amit tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); 5271a4a118f2SNadav Amit force_flush = true; 52724ddb4d91SMike Kravetz address |= last_addr_mask; 527331d49da5SAneesh Kumar K.V continue; 527431d49da5SAneesh Kumar K.V } 527539dde65cSChen, Kenneth W 52766629326bSHillf Danton pte = huge_ptep_get(ptep); 527731d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 527831d49da5SAneesh Kumar K.V spin_unlock(ptl); 527931d49da5SAneesh Kumar K.V continue; 528031d49da5SAneesh Kumar K.V } 52816629326bSHillf Danton 52826629326bSHillf Danton /* 52839fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 52849fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 52856629326bSHillf Danton */ 52869fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 528705e90bd0SPeter Xu /* 528805e90bd0SPeter Xu * If the pte was wr-protected by uffd-wp in any of the 528905e90bd0SPeter Xu * swap forms, meanwhile the caller does not want to 529005e90bd0SPeter Xu * drop the uffd-wp bit in this zap, then replace the 529105e90bd0SPeter Xu * pte with a marker. 529205e90bd0SPeter Xu */ 529305e90bd0SPeter Xu if (pte_swp_uffd_wp_any(pte) && 529405e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 529505e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 529605e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 529705e90bd0SPeter Xu else 52989386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 529931d49da5SAneesh Kumar K.V spin_unlock(ptl); 530031d49da5SAneesh Kumar K.V continue; 53018c4894c6SNaoya Horiguchi } 53026629326bSHillf Danton 53036629326bSHillf Danton page = pte_page(pte); 530404f2cbe3SMel Gorman /* 530504f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 530604f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 530704f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 530804f2cbe3SMel Gorman */ 530904f2cbe3SMel Gorman if (ref_page) { 531031d49da5SAneesh Kumar K.V if (page != ref_page) { 531131d49da5SAneesh Kumar K.V spin_unlock(ptl); 531231d49da5SAneesh Kumar K.V continue; 531331d49da5SAneesh Kumar K.V } 531404f2cbe3SMel Gorman /* 531504f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 531604f2cbe3SMel Gorman * future faults in this VMA will fail rather than 531704f2cbe3SMel Gorman * looking like data was lost 531804f2cbe3SMel Gorman */ 531904f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 532004f2cbe3SMel Gorman } 532104f2cbe3SMel Gorman 5322c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 5323b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 5324106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 53256649a386SKen Chen set_page_dirty(page); 532605e90bd0SPeter Xu /* Leave a uffd-wp pte marker if needed */ 532705e90bd0SPeter Xu if (huge_pte_uffd_wp(pte) && 532805e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 532905e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 533005e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 53315d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 5332cea86fe2SHugh Dickins page_remove_rmap(page, vma, true); 533331d49da5SAneesh Kumar K.V 5334cb900f41SKirill A. Shutemov spin_unlock(ptl); 5335e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 533624669e58SAneesh Kumar K.V /* 533731d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 533824669e58SAneesh Kumar K.V */ 533931d49da5SAneesh Kumar K.V if (ref_page) 534031d49da5SAneesh Kumar K.V break; 5341fe1668aeSChen, Kenneth W } 534224669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 5343a4a118f2SNadav Amit 5344a4a118f2SNadav Amit /* 5345a4a118f2SNadav Amit * If we unshared PMDs, the TLB flush was not recorded in mmu_gather. We 5346a4a118f2SNadav Amit * could defer the flush until now, since by holding i_mmap_rwsem we 5347a4a118f2SNadav Amit * guaranteed that the last refernece would not be dropped. But we must 5348a4a118f2SNadav Amit * do the flushing before we return, as otherwise i_mmap_rwsem will be 5349a4a118f2SNadav Amit * dropped and the last reference to the shared PMDs page might be 5350a4a118f2SNadav Amit * dropped as well. 5351a4a118f2SNadav Amit * 5352a4a118f2SNadav Amit * In theory we could defer the freeing of the PMD pages as well, but 5353a4a118f2SNadav Amit * huge_pmd_unshare() relies on the exact page_count for the PMD page to 5354a4a118f2SNadav Amit * detect sharing, so we cannot defer the release of the page either. 5355a4a118f2SNadav Amit * Instead, do flush now. 5356a4a118f2SNadav Amit */ 5357a4a118f2SNadav Amit if (force_flush) 5358a4a118f2SNadav Amit tlb_flush_mmu_tlbonly(tlb); 53591da177e4SLinus Torvalds } 536063551ae0SDavid Gibson 5361d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 5362d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 536305e90bd0SPeter Xu unsigned long end, struct page *ref_page, 536405e90bd0SPeter Xu zap_flags_t zap_flags) 5365d833352aSMel Gorman { 5366131a79b4SMike Kravetz hugetlb_vma_lock_write(vma); 5367131a79b4SMike Kravetz i_mmap_lock_write(vma->vm_file->f_mapping); 5368131a79b4SMike Kravetz 5369369258ceSMike Kravetz /* mmu notification performed in caller */ 537005e90bd0SPeter Xu __unmap_hugepage_range(tlb, vma, start, end, ref_page, zap_flags); 5371d833352aSMel Gorman 537204ada095SMike Kravetz if (zap_flags & ZAP_FLAG_UNMAP) { /* final unmap */ 5373d833352aSMel Gorman /* 537404ada095SMike Kravetz * Unlock and free the vma lock before releasing i_mmap_rwsem. 537504ada095SMike Kravetz * When the vma_lock is freed, this makes the vma ineligible 537604ada095SMike Kravetz * for pmd sharing. And, i_mmap_rwsem is required to set up 537704ada095SMike Kravetz * pmd sharing. This is important as page tables for this 537804ada095SMike Kravetz * unmapped range will be asynchrously deleted. If the page 537904ada095SMike Kravetz * tables are shared, there will be issues when accessed by 538004ada095SMike Kravetz * someone else. 5381d833352aSMel Gorman */ 5382ecfbd733SMike Kravetz __hugetlb_vma_unlock_write_free(vma); 5383131a79b4SMike Kravetz i_mmap_unlock_write(vma->vm_file->f_mapping); 538404ada095SMike Kravetz } else { 538504ada095SMike Kravetz i_mmap_unlock_write(vma->vm_file->f_mapping); 538604ada095SMike Kravetz hugetlb_vma_unlock_write(vma); 538704ada095SMike Kravetz } 5388d833352aSMel Gorman } 5389d833352aSMel Gorman 5390502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 539105e90bd0SPeter Xu unsigned long end, struct page *ref_page, 539205e90bd0SPeter Xu zap_flags_t zap_flags) 5393502717f4SChen, Kenneth W { 5394369258ceSMike Kravetz struct mmu_notifier_range range; 539524669e58SAneesh Kumar K.V struct mmu_gather tlb; 5396dff11abeSMike Kravetz 5397369258ceSMike Kravetz mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm, 5398369258ceSMike Kravetz start, end); 5399369258ceSMike Kravetz adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 5400369258ceSMike Kravetz mmu_notifier_invalidate_range_start(&range); 5401a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 5402369258ceSMike Kravetz 540305e90bd0SPeter Xu __unmap_hugepage_range(&tlb, vma, start, end, ref_page, zap_flags); 5404369258ceSMike Kravetz 5405369258ceSMike Kravetz mmu_notifier_invalidate_range_end(&range); 5406ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 5407502717f4SChen, Kenneth W } 5408502717f4SChen, Kenneth W 540904f2cbe3SMel Gorman /* 541004f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 5411578b7725SZhiyuan Dai * mapping it owns the reserve page for. The intention is to unmap the page 541204f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 541304f2cbe3SMel Gorman * same region. 541404f2cbe3SMel Gorman */ 54152f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 54162a4b3dedSHarvey Harrison struct page *page, unsigned long address) 541704f2cbe3SMel Gorman { 54187526674dSAdam Litke struct hstate *h = hstate_vma(vma); 541904f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 542004f2cbe3SMel Gorman struct address_space *mapping; 542104f2cbe3SMel Gorman pgoff_t pgoff; 542204f2cbe3SMel Gorman 542304f2cbe3SMel Gorman /* 542404f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 542504f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 542604f2cbe3SMel Gorman */ 54277526674dSAdam Litke address = address & huge_page_mask(h); 542836e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 542936e4f20aSMichal Hocko vma->vm_pgoff; 543093c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 543104f2cbe3SMel Gorman 54324eb2b1dcSMel Gorman /* 54334eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 54344eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 54354eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 54364eb2b1dcSMel Gorman */ 543783cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 54386b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 543904f2cbe3SMel Gorman /* Do not unmap the current VMA */ 544004f2cbe3SMel Gorman if (iter_vma == vma) 544104f2cbe3SMel Gorman continue; 544204f2cbe3SMel Gorman 544304f2cbe3SMel Gorman /* 54442f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 54452f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 54462f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 54472f84a899SMel Gorman */ 54482f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 54492f84a899SMel Gorman continue; 54502f84a899SMel Gorman 54512f84a899SMel Gorman /* 545204f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 545304f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 545404f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 545504f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 545604f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 545704f2cbe3SMel Gorman */ 545804f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 545924669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 546005e90bd0SPeter Xu address + huge_page_size(h), page, 0); 546104f2cbe3SMel Gorman } 546283cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 546304f2cbe3SMel Gorman } 546404f2cbe3SMel Gorman 54650fe6e20bSNaoya Horiguchi /* 5466c89357e2SDavid Hildenbrand * hugetlb_wp() should be called with page lock of the original hugepage held. 5467aa6d2e8cSBaolin Wang * Called with hugetlb_fault_mutex_table held and pte_page locked so we 5468ef009b25SMichal Hocko * cannot race with other handlers or page migration. 5469ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 54700fe6e20bSNaoya Horiguchi */ 5471c89357e2SDavid Hildenbrand static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, 5472c89357e2SDavid Hildenbrand unsigned long address, pte_t *ptep, unsigned int flags, 5473cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 54741e8f889bSDavid Gibson { 5475c89357e2SDavid Hildenbrand const bool unshare = flags & FAULT_FLAG_UNSHARE; 54763999f52eSAneesh Kumar K.V pte_t pte; 5477a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 54781e8f889bSDavid Gibson struct page *old_page, *new_page; 54792b740303SSouptick Joarder int outside_reserve = 0; 54802b740303SSouptick Joarder vm_fault_t ret = 0; 5481974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 5482ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 54831e8f889bSDavid Gibson 54841d8d1464SDavid Hildenbrand /* 54851d8d1464SDavid Hildenbrand * hugetlb does not support FOLL_FORCE-style write faults that keep the 54861d8d1464SDavid Hildenbrand * PTE mapped R/O such as maybe_mkwrite() would do. 54871d8d1464SDavid Hildenbrand */ 54881d8d1464SDavid Hildenbrand if (WARN_ON_ONCE(!unshare && !(vma->vm_flags & VM_WRITE))) 54891d8d1464SDavid Hildenbrand return VM_FAULT_SIGSEGV; 54901d8d1464SDavid Hildenbrand 54911d8d1464SDavid Hildenbrand /* Let's take out MAP_SHARED mappings first. */ 54921d8d1464SDavid Hildenbrand if (vma->vm_flags & VM_MAYSHARE) { 54931d8d1464SDavid Hildenbrand set_huge_ptep_writable(vma, haddr, ptep); 54941d8d1464SDavid Hildenbrand return 0; 54951d8d1464SDavid Hildenbrand } 54961d8d1464SDavid Hildenbrand 54973999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 54981e8f889bSDavid Gibson old_page = pte_page(pte); 54991e8f889bSDavid Gibson 5500662ce1dcSYang Yang delayacct_wpcopy_start(); 5501662ce1dcSYang Yang 550204f2cbe3SMel Gorman retry_avoidcopy: 5503c89357e2SDavid Hildenbrand /* 5504c89357e2SDavid Hildenbrand * If no-one else is actually using this page, we're the exclusive 5505c89357e2SDavid Hildenbrand * owner and can reuse this page. 5506c89357e2SDavid Hildenbrand */ 550737a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 5508c89357e2SDavid Hildenbrand if (!PageAnonExclusive(old_page)) 55095a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 5510c89357e2SDavid Hildenbrand if (likely(!unshare)) 55115b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 5512662ce1dcSYang Yang 5513662ce1dcSYang Yang delayacct_wpcopy_end(); 551483c54070SNick Piggin return 0; 55151e8f889bSDavid Gibson } 55166c287605SDavid Hildenbrand VM_BUG_ON_PAGE(PageAnon(old_page) && PageAnonExclusive(old_page), 55176c287605SDavid Hildenbrand old_page); 55181e8f889bSDavid Gibson 551904f2cbe3SMel Gorman /* 552004f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 552104f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 552204f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 552304f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 552404f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 552504f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 552604f2cbe3SMel Gorman * of the full address range. 552704f2cbe3SMel Gorman */ 55285944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 552904f2cbe3SMel Gorman old_page != pagecache_page) 553004f2cbe3SMel Gorman outside_reserve = 1; 553104f2cbe3SMel Gorman 553209cbfeafSKirill A. Shutemov get_page(old_page); 5533b76c8cfbSLarry Woodman 5534ad4404a2SDavidlohr Bueso /* 5535ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 5536ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 5537ad4404a2SDavidlohr Bueso */ 5538cb900f41SKirill A. Shutemov spin_unlock(ptl); 55395b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 55401e8f889bSDavid Gibson 55412fc39cecSAdam Litke if (IS_ERR(new_page)) { 554204f2cbe3SMel Gorman /* 554304f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 554404f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 554504f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 554604f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 554704f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 554804f2cbe3SMel Gorman */ 554904f2cbe3SMel Gorman if (outside_reserve) { 555040549ba8SMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 555140549ba8SMike Kravetz pgoff_t idx; 555240549ba8SMike Kravetz u32 hash; 555340549ba8SMike Kravetz 555409cbfeafSKirill A. Shutemov put_page(old_page); 555540549ba8SMike Kravetz /* 555640549ba8SMike Kravetz * Drop hugetlb_fault_mutex and vma_lock before 555740549ba8SMike Kravetz * unmapping. unmapping needs to hold vma_lock 555840549ba8SMike Kravetz * in write mode. Dropping vma_lock in read mode 555940549ba8SMike Kravetz * here is OK as COW mappings do not interact with 556040549ba8SMike Kravetz * PMD sharing. 556140549ba8SMike Kravetz * 556240549ba8SMike Kravetz * Reacquire both after unmap operation. 556340549ba8SMike Kravetz */ 556440549ba8SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 556540549ba8SMike Kravetz hash = hugetlb_fault_mutex_hash(mapping, idx); 556640549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 556740549ba8SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 556840549ba8SMike Kravetz 55695b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 557040549ba8SMike Kravetz 557140549ba8SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 557240549ba8SMike Kravetz hugetlb_vma_lock_read(vma); 5573cb900f41SKirill A. Shutemov spin_lock(ptl); 55745b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5575a9af0c5dSNaoya Horiguchi if (likely(ptep && 5576a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 557704f2cbe3SMel Gorman goto retry_avoidcopy; 5578a734bcc8SHillf Danton /* 5579cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 5580cb900f41SKirill A. Shutemov * lock, and our job is done. 5581a734bcc8SHillf Danton */ 5582662ce1dcSYang Yang delayacct_wpcopy_end(); 5583a734bcc8SHillf Danton return 0; 558404f2cbe3SMel Gorman } 558504f2cbe3SMel Gorman 55862b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 5587ad4404a2SDavidlohr Bueso goto out_release_old; 55881e8f889bSDavid Gibson } 55891e8f889bSDavid Gibson 55900fe6e20bSNaoya Horiguchi /* 55910fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 55920fe6e20bSNaoya Horiguchi * anon_vma prepared. 55930fe6e20bSNaoya Horiguchi */ 559444e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 5595ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 5596ad4404a2SDavidlohr Bueso goto out_release_all; 559744e2aa93SDean Nelson } 55980fe6e20bSNaoya Horiguchi 5599974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 560047ad8475SAndrea Arcangeli pages_per_huge_page(h)); 56010ed361deSNick Piggin __SetPageUptodate(new_page); 56021e8f889bSDavid Gibson 56037269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 56046f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 5605ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5606ad4404a2SDavidlohr Bueso 5607b76c8cfbSLarry Woodman /* 5608cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 5609b76c8cfbSLarry Woodman * before the page tables are altered 5610b76c8cfbSLarry Woodman */ 5611cb900f41SKirill A. Shutemov spin_lock(ptl); 56125b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5613a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 5614c89357e2SDavid Hildenbrand /* Break COW or unshare */ 56155b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 5616ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 5617cea86fe2SHugh Dickins page_remove_rmap(old_page, vma, true); 56185b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 56191eba86c0SPasha Tatashin set_huge_pte_at(mm, haddr, ptep, 5620c89357e2SDavid Hildenbrand make_huge_pte(vma, new_page, !unshare)); 56218f251a3dSMike Kravetz SetHPageMigratable(new_page); 56221e8f889bSDavid Gibson /* Make the old page be freed below */ 56231e8f889bSDavid Gibson new_page = old_page; 56241e8f889bSDavid Gibson } 5625cb900f41SKirill A. Shutemov spin_unlock(ptl); 5626ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 5627ad4404a2SDavidlohr Bueso out_release_all: 5628c89357e2SDavid Hildenbrand /* 5629c89357e2SDavid Hildenbrand * No restore in case of successful pagetable update (Break COW or 5630c89357e2SDavid Hildenbrand * unshare) 5631c89357e2SDavid Hildenbrand */ 5632c7b1850dSMike Kravetz if (new_page != old_page) 56335b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 563409cbfeafSKirill A. Shutemov put_page(new_page); 5635ad4404a2SDavidlohr Bueso out_release_old: 563609cbfeafSKirill A. Shutemov put_page(old_page); 56378312034fSJoonsoo Kim 5638ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 5639662ce1dcSYang Yang 5640662ce1dcSYang Yang delayacct_wpcopy_end(); 5641ad4404a2SDavidlohr Bueso return ret; 56421e8f889bSDavid Gibson } 56431e8f889bSDavid Gibson 56443ae77f43SHugh Dickins /* 56453ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 56463ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 56473ae77f43SHugh Dickins */ 56483ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 56492a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 56502a15efc9SHugh Dickins { 56512a15efc9SHugh Dickins struct address_space *mapping; 56522a15efc9SHugh Dickins pgoff_t idx; 56532a15efc9SHugh Dickins struct page *page; 56542a15efc9SHugh Dickins 56552a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 56562a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 56572a15efc9SHugh Dickins 56582a15efc9SHugh Dickins page = find_get_page(mapping, idx); 56592a15efc9SHugh Dickins if (page) 56602a15efc9SHugh Dickins put_page(page); 56612a15efc9SHugh Dickins return page != NULL; 56622a15efc9SHugh Dickins } 56632a15efc9SHugh Dickins 56647e1813d4SMike Kravetz int hugetlb_add_to_page_cache(struct page *page, struct address_space *mapping, 5665ab76ad54SMike Kravetz pgoff_t idx) 5666ab76ad54SMike Kravetz { 5667d9ef44deSMatthew Wilcox (Oracle) struct folio *folio = page_folio(page); 5668ab76ad54SMike Kravetz struct inode *inode = mapping->host; 5669ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 5670d9ef44deSMatthew Wilcox (Oracle) int err; 5671ab76ad54SMike Kravetz 5672d9ef44deSMatthew Wilcox (Oracle) __folio_set_locked(folio); 5673d9ef44deSMatthew Wilcox (Oracle) err = __filemap_add_folio(mapping, folio, idx, GFP_KERNEL, NULL); 5674d9ef44deSMatthew Wilcox (Oracle) 5675d9ef44deSMatthew Wilcox (Oracle) if (unlikely(err)) { 5676d9ef44deSMatthew Wilcox (Oracle) __folio_clear_locked(folio); 5677ab76ad54SMike Kravetz return err; 5678d9ef44deSMatthew Wilcox (Oracle) } 5679d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5680ab76ad54SMike Kravetz 568122146c3cSMike Kravetz /* 5682d9ef44deSMatthew Wilcox (Oracle) * mark folio dirty so that it will not be removed from cache/file 568322146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 568422146c3cSMike Kravetz */ 5685d9ef44deSMatthew Wilcox (Oracle) folio_mark_dirty(folio); 568622146c3cSMike Kravetz 5687ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 5688ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 5689ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 5690ab76ad54SMike Kravetz return 0; 5691ab76ad54SMike Kravetz } 5692ab76ad54SMike Kravetz 56937677f7fdSAxel Rasmussen static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma, 56947677f7fdSAxel Rasmussen struct address_space *mapping, 56957677f7fdSAxel Rasmussen pgoff_t idx, 56967677f7fdSAxel Rasmussen unsigned int flags, 56977677f7fdSAxel Rasmussen unsigned long haddr, 5698824ddc60SNadav Amit unsigned long addr, 56997677f7fdSAxel Rasmussen unsigned long reason) 57007677f7fdSAxel Rasmussen { 57017677f7fdSAxel Rasmussen u32 hash; 57027677f7fdSAxel Rasmussen struct vm_fault vmf = { 57037677f7fdSAxel Rasmussen .vma = vma, 57047677f7fdSAxel Rasmussen .address = haddr, 5705824ddc60SNadav Amit .real_address = addr, 57067677f7fdSAxel Rasmussen .flags = flags, 57077677f7fdSAxel Rasmussen 57087677f7fdSAxel Rasmussen /* 57097677f7fdSAxel Rasmussen * Hard to debug if it ends up being 57107677f7fdSAxel Rasmussen * used by a callee that assumes 57117677f7fdSAxel Rasmussen * something about the other 57127677f7fdSAxel Rasmussen * uninitialized fields... same as in 57137677f7fdSAxel Rasmussen * memory.c 57147677f7fdSAxel Rasmussen */ 57157677f7fdSAxel Rasmussen }; 57167677f7fdSAxel Rasmussen 57177677f7fdSAxel Rasmussen /* 5718958f32ceSLiu Shixin * vma_lock and hugetlb_fault_mutex must be dropped before handling 5719958f32ceSLiu Shixin * userfault. Also mmap_lock could be dropped due to handling 5720958f32ceSLiu Shixin * userfault, any vma operation should be careful from here. 57217677f7fdSAxel Rasmussen */ 572240549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 57237677f7fdSAxel Rasmussen hash = hugetlb_fault_mutex_hash(mapping, idx); 57247677f7fdSAxel Rasmussen mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5725958f32ceSLiu Shixin return handle_userfault(&vmf, reason); 57267677f7fdSAxel Rasmussen } 57277677f7fdSAxel Rasmussen 57282ea7ff1eSPeter Xu /* 57292ea7ff1eSPeter Xu * Recheck pte with pgtable lock. Returns true if pte didn't change, or 57302ea7ff1eSPeter Xu * false if pte changed or is changing. 57312ea7ff1eSPeter Xu */ 57322ea7ff1eSPeter Xu static bool hugetlb_pte_stable(struct hstate *h, struct mm_struct *mm, 57332ea7ff1eSPeter Xu pte_t *ptep, pte_t old_pte) 57342ea7ff1eSPeter Xu { 57352ea7ff1eSPeter Xu spinlock_t *ptl; 57362ea7ff1eSPeter Xu bool same; 57372ea7ff1eSPeter Xu 57382ea7ff1eSPeter Xu ptl = huge_pte_lock(h, mm, ptep); 57392ea7ff1eSPeter Xu same = pte_same(huge_ptep_get(ptep), old_pte); 57402ea7ff1eSPeter Xu spin_unlock(ptl); 57412ea7ff1eSPeter Xu 57422ea7ff1eSPeter Xu return same; 57432ea7ff1eSPeter Xu } 57442ea7ff1eSPeter Xu 57452b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 57462b740303SSouptick Joarder struct vm_area_struct *vma, 57478382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 5748c64e912cSPeter Xu unsigned long address, pte_t *ptep, 5749c64e912cSPeter Xu pte_t old_pte, unsigned int flags) 5750ac9b9c66SHugh Dickins { 5751a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 57522b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 5753409eb8c2SHillf Danton int anon_rmap = 0; 57544c887265SAdam Litke unsigned long size; 57554c887265SAdam Litke struct page *page; 57561e8f889bSDavid Gibson pte_t new_pte; 5757cb900f41SKirill A. Shutemov spinlock_t *ptl; 5758285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 5759c7b1850dSMike Kravetz bool new_page, new_pagecache_page = false; 5760958f32ceSLiu Shixin u32 hash = hugetlb_fault_mutex_hash(mapping, idx); 57614c887265SAdam Litke 576204f2cbe3SMel Gorman /* 576304f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 576404f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 5765c89357e2SDavid Hildenbrand * COW/unsharing. Warn that such a situation has occurred as it may not 5766c89357e2SDavid Hildenbrand * be obvious. 576704f2cbe3SMel Gorman */ 576804f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 5769910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 577004f2cbe3SMel Gorman current->pid); 5771958f32ceSLiu Shixin goto out; 577204f2cbe3SMel Gorman } 577304f2cbe3SMel Gorman 57744c887265SAdam Litke /* 5775188a3972SMike Kravetz * Use page lock to guard against racing truncation 5776188a3972SMike Kravetz * before we get page_table_lock. 57774c887265SAdam Litke */ 5778c7b1850dSMike Kravetz new_page = false; 577987bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 578087bf91d3SMike Kravetz if (!page) { 5781188a3972SMike Kravetz size = i_size_read(mapping->host) >> huge_page_shift(h); 5782188a3972SMike Kravetz if (idx >= size) 5783188a3972SMike Kravetz goto out; 57847677f7fdSAxel Rasmussen /* Check for page in userfault range */ 57852ea7ff1eSPeter Xu if (userfaultfd_missing(vma)) { 57862ea7ff1eSPeter Xu /* 57872ea7ff1eSPeter Xu * Since hugetlb_no_page() was examining pte 57882ea7ff1eSPeter Xu * without pgtable lock, we need to re-test under 57892ea7ff1eSPeter Xu * lock because the pte may not be stable and could 57902ea7ff1eSPeter Xu * have changed from under us. Try to detect 57912ea7ff1eSPeter Xu * either changed or during-changing ptes and retry 57922ea7ff1eSPeter Xu * properly when needed. 57932ea7ff1eSPeter Xu * 57942ea7ff1eSPeter Xu * Note that userfaultfd is actually fine with 57952ea7ff1eSPeter Xu * false positives (e.g. caused by pte changed), 57962ea7ff1eSPeter Xu * but not wrong logical events (e.g. caused by 57972ea7ff1eSPeter Xu * reading a pte during changing). The latter can 57982ea7ff1eSPeter Xu * confuse the userspace, so the strictness is very 57992ea7ff1eSPeter Xu * much preferred. E.g., MISSING event should 58002ea7ff1eSPeter Xu * never happen on the page after UFFDIO_COPY has 58012ea7ff1eSPeter Xu * correctly installed the page and returned. 58022ea7ff1eSPeter Xu */ 58032ea7ff1eSPeter Xu if (!hugetlb_pte_stable(h, mm, ptep, old_pte)) { 58042ea7ff1eSPeter Xu ret = 0; 58052ea7ff1eSPeter Xu goto out; 58062ea7ff1eSPeter Xu } 58072ea7ff1eSPeter Xu 58082ea7ff1eSPeter Xu return hugetlb_handle_userfault(vma, mapping, idx, flags, 58092ea7ff1eSPeter Xu haddr, address, 58107677f7fdSAxel Rasmussen VM_UFFD_MISSING); 58112ea7ff1eSPeter Xu } 58121a1aad8aSMike Kravetz 5813285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 58142fc39cecSAdam Litke if (IS_ERR(page)) { 58154643d67eSMike Kravetz /* 58164643d67eSMike Kravetz * Returning error will result in faulting task being 58174643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 58184643d67eSMike Kravetz * tasks from racing to fault in the same page which 58194643d67eSMike Kravetz * could result in false unable to allocate errors. 58204643d67eSMike Kravetz * Page migration does not take the fault mutex, but 58214643d67eSMike Kravetz * does a clear then write of pte's under page table 58224643d67eSMike Kravetz * lock. Page fault code could race with migration, 58234643d67eSMike Kravetz * notice the clear pte and try to allocate a page 58244643d67eSMike Kravetz * here. Before returning error, get ptl and make 58254643d67eSMike Kravetz * sure there really is no pte entry. 58264643d67eSMike Kravetz */ 5827f9bf6c03SPeter Xu if (hugetlb_pte_stable(h, mm, ptep, old_pte)) 58282b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 5829f9bf6c03SPeter Xu else 5830f9bf6c03SPeter Xu ret = 0; 58316bda666aSChristoph Lameter goto out; 58326bda666aSChristoph Lameter } 583347ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 58340ed361deSNick Piggin __SetPageUptodate(page); 5835cb6acd01SMike Kravetz new_page = true; 5836ac9b9c66SHugh Dickins 5837f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 58387e1813d4SMike Kravetz int err = hugetlb_add_to_page_cache(page, mapping, idx); 58396bda666aSChristoph Lameter if (err) { 58403a5497a2SMiaohe Lin /* 58413a5497a2SMiaohe Lin * err can't be -EEXIST which implies someone 58423a5497a2SMiaohe Lin * else consumed the reservation since hugetlb 58433a5497a2SMiaohe Lin * fault mutex is held when add a hugetlb page 58443a5497a2SMiaohe Lin * to the page cache. So it's safe to call 58453a5497a2SMiaohe Lin * restore_reserve_on_error() here. 58463a5497a2SMiaohe Lin */ 58473a5497a2SMiaohe Lin restore_reserve_on_error(h, vma, haddr, page); 58486bda666aSChristoph Lameter put_page(page); 58496bda666aSChristoph Lameter goto out; 58506bda666aSChristoph Lameter } 5851c7b1850dSMike Kravetz new_pagecache_page = true; 585223be7468SMel Gorman } else { 58536bda666aSChristoph Lameter lock_page(page); 58540fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 58550fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 58560fe6e20bSNaoya Horiguchi goto backout_unlocked; 585723be7468SMel Gorman } 5858409eb8c2SHillf Danton anon_rmap = 1; 58590fe6e20bSNaoya Horiguchi } 58600fe6e20bSNaoya Horiguchi } else { 586157303d80SAndy Whitcroft /* 5862998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 5863998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 5864998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 5865fd6a03edSNaoya Horiguchi */ 5866fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 58670eb98f15SMiaohe Lin ret = VM_FAULT_HWPOISON_LARGE | 5868972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5869fd6a03edSNaoya Horiguchi goto backout_unlocked; 58706bda666aSChristoph Lameter } 58717677f7fdSAxel Rasmussen 58727677f7fdSAxel Rasmussen /* Check for page in userfault range. */ 58737677f7fdSAxel Rasmussen if (userfaultfd_minor(vma)) { 58747677f7fdSAxel Rasmussen unlock_page(page); 58757677f7fdSAxel Rasmussen put_page(page); 58762ea7ff1eSPeter Xu /* See comment in userfaultfd_missing() block above */ 58772ea7ff1eSPeter Xu if (!hugetlb_pte_stable(h, mm, ptep, old_pte)) { 58782ea7ff1eSPeter Xu ret = 0; 58792ea7ff1eSPeter Xu goto out; 58802ea7ff1eSPeter Xu } 58812ea7ff1eSPeter Xu return hugetlb_handle_userfault(vma, mapping, idx, flags, 58822ea7ff1eSPeter Xu haddr, address, 58837677f7fdSAxel Rasmussen VM_UFFD_MINOR); 58847677f7fdSAxel Rasmussen } 5885998b4382SNaoya Horiguchi } 58861e8f889bSDavid Gibson 588757303d80SAndy Whitcroft /* 588857303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 588957303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 589057303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 589157303d80SAndy Whitcroft * the spinlock. 589257303d80SAndy Whitcroft */ 58935e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 5894285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 58952b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 58962b26736cSAndy Whitcroft goto backout_unlocked; 58972b26736cSAndy Whitcroft } 58985e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5899285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 59005e911373SMike Kravetz } 590157303d80SAndy Whitcroft 59028bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 590383c54070SNick Piggin ret = 0; 5904c64e912cSPeter Xu /* If pte changed from under us, retry */ 5905c64e912cSPeter Xu if (!pte_same(huge_ptep_get(ptep), old_pte)) 59064c887265SAdam Litke goto backout; 59074c887265SAdam Litke 59084781593dSPeter Xu if (anon_rmap) 5909285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 59104781593dSPeter Xu else 5911fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 59121e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 59131e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 5914c64e912cSPeter Xu /* 5915c64e912cSPeter Xu * If this pte was previously wr-protected, keep it wr-protected even 5916c64e912cSPeter Xu * if populated. 5917c64e912cSPeter Xu */ 5918c64e912cSPeter Xu if (unlikely(pte_marker_uffd_wp(old_pte))) 5919c64e912cSPeter Xu new_pte = huge_pte_wrprotect(huge_pte_mkuffd_wp(new_pte)); 5920285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 59211e8f889bSDavid Gibson 59225d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 5923788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 59241e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 5925c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, page, ptl); 59261e8f889bSDavid Gibson } 59271e8f889bSDavid Gibson 5928cb900f41SKirill A. Shutemov spin_unlock(ptl); 5929cb6acd01SMike Kravetz 5930cb6acd01SMike Kravetz /* 59318f251a3dSMike Kravetz * Only set HPageMigratable in newly allocated pages. Existing pages 59328f251a3dSMike Kravetz * found in the pagecache may not have HPageMigratableset if they have 59338f251a3dSMike Kravetz * been isolated for migration. 5934cb6acd01SMike Kravetz */ 5935cb6acd01SMike Kravetz if (new_page) 59368f251a3dSMike Kravetz SetHPageMigratable(page); 5937cb6acd01SMike Kravetz 59384c887265SAdam Litke unlock_page(page); 59394c887265SAdam Litke out: 5940958f32ceSLiu Shixin hugetlb_vma_unlock_read(vma); 5941958f32ceSLiu Shixin mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5942ac9b9c66SHugh Dickins return ret; 59434c887265SAdam Litke 59444c887265SAdam Litke backout: 5945cb900f41SKirill A. Shutemov spin_unlock(ptl); 59462b26736cSAndy Whitcroft backout_unlocked: 5947c7b1850dSMike Kravetz if (new_page && !new_pagecache_page) 5948285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 5949fa27759aSMike Kravetz 5950fa27759aSMike Kravetz unlock_page(page); 59514c887265SAdam Litke put_page(page); 59524c887265SAdam Litke goto out; 5953ac9b9c66SHugh Dickins } 5954ac9b9c66SHugh Dickins 59558382d914SDavidlohr Bueso #ifdef CONFIG_SMP 5956188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 59578382d914SDavidlohr Bueso { 59588382d914SDavidlohr Bueso unsigned long key[2]; 59598382d914SDavidlohr Bueso u32 hash; 59608382d914SDavidlohr Bueso 59618382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 59628382d914SDavidlohr Bueso key[1] = idx; 59638382d914SDavidlohr Bueso 596455254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 59658382d914SDavidlohr Bueso 59668382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 59678382d914SDavidlohr Bueso } 59688382d914SDavidlohr Bueso #else 59698382d914SDavidlohr Bueso /* 59706c26d310SMiaohe Lin * For uniprocessor systems we always use a single mutex, so just 59718382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 59728382d914SDavidlohr Bueso */ 5973188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 59748382d914SDavidlohr Bueso { 59758382d914SDavidlohr Bueso return 0; 59768382d914SDavidlohr Bueso } 59778382d914SDavidlohr Bueso #endif 59788382d914SDavidlohr Bueso 59792b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 5980788c7df4SHugh Dickins unsigned long address, unsigned int flags) 598186e5216fSAdam Litke { 59828382d914SDavidlohr Bueso pte_t *ptep, entry; 5983cb900f41SKirill A. Shutemov spinlock_t *ptl; 59842b740303SSouptick Joarder vm_fault_t ret; 59858382d914SDavidlohr Bueso u32 hash; 59868382d914SDavidlohr Bueso pgoff_t idx; 59870fe6e20bSNaoya Horiguchi struct page *page = NULL; 598857303d80SAndy Whitcroft struct page *pagecache_page = NULL; 5989a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 59908382d914SDavidlohr Bueso struct address_space *mapping; 59910f792cf9SNaoya Horiguchi int need_wait_lock = 0; 5992285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 599386e5216fSAdam Litke 5994285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5995fd6a03edSNaoya Horiguchi if (ptep) { 599640549ba8SMike Kravetz /* 599740549ba8SMike Kravetz * Since we hold no locks, ptep could be stale. That is 599840549ba8SMike Kravetz * OK as we are only making decisions based on content and 599940549ba8SMike Kravetz * not actually modifying content here. 600040549ba8SMike Kravetz */ 6001fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 6002290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 6003ad1ac596SMiaohe Lin migration_entry_wait_huge(vma, ptep); 6004290408d4SNaoya Horiguchi return 0; 6005290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 6006aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 6007972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 6008c0d0381aSMike Kravetz } 6009ddeaab32SMike Kravetz 60103935baa9SDavid Gibson /* 60113935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 60123935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 60133935baa9SDavid Gibson * the same page in the page cache. 60143935baa9SDavid Gibson */ 601540549ba8SMike Kravetz mapping = vma->vm_file->f_mapping; 601640549ba8SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 6017188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 6018c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 60198382d914SDavidlohr Bueso 602040549ba8SMike Kravetz /* 602140549ba8SMike Kravetz * Acquire vma lock before calling huge_pte_alloc and hold 602240549ba8SMike Kravetz * until finished with ptep. This prevents huge_pmd_unshare from 602340549ba8SMike Kravetz * being called elsewhere and making the ptep no longer valid. 602440549ba8SMike Kravetz * 602540549ba8SMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 602640549ba8SMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 602740549ba8SMike Kravetz * something has changed. 602840549ba8SMike Kravetz */ 602940549ba8SMike Kravetz hugetlb_vma_lock_read(vma); 603040549ba8SMike Kravetz ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h)); 603140549ba8SMike Kravetz if (!ptep) { 603240549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 603340549ba8SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 603440549ba8SMike Kravetz return VM_FAULT_OOM; 603540549ba8SMike Kravetz } 603640549ba8SMike Kravetz 60377f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 6038c64e912cSPeter Xu /* PTE markers should be handled the same way as none pte */ 6039958f32ceSLiu Shixin if (huge_pte_none_mostly(entry)) 6040958f32ceSLiu Shixin /* 6041958f32ceSLiu Shixin * hugetlb_no_page will drop vma lock and hugetlb fault 6042958f32ceSLiu Shixin * mutex internally, which make us return immediately. 6043958f32ceSLiu Shixin */ 6044958f32ceSLiu Shixin return hugetlb_no_page(mm, vma, mapping, idx, address, ptep, 6045c64e912cSPeter Xu entry, flags); 604686e5216fSAdam Litke 604783c54070SNick Piggin ret = 0; 60481e8f889bSDavid Gibson 604957303d80SAndy Whitcroft /* 60500f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 60510f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 60527c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 60537c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 60547c8de358SEthon Paul * properly handle it. 60550f792cf9SNaoya Horiguchi */ 60560f792cf9SNaoya Horiguchi if (!pte_present(entry)) 60570f792cf9SNaoya Horiguchi goto out_mutex; 60580f792cf9SNaoya Horiguchi 60590f792cf9SNaoya Horiguchi /* 6060c89357e2SDavid Hildenbrand * If we are going to COW/unshare the mapping later, we examine the 6061c89357e2SDavid Hildenbrand * pending reservations for this page now. This will ensure that any 606257303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 60631d8d1464SDavid Hildenbrand * spinlock. Also lookup the pagecache page now as it is used to 60641d8d1464SDavid Hildenbrand * determine if a reservation has been consumed. 606557303d80SAndy Whitcroft */ 6066c89357e2SDavid Hildenbrand if ((flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) && 60671d8d1464SDavid Hildenbrand !(vma->vm_flags & VM_MAYSHARE) && !huge_pte_write(entry)) { 6068285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 60692b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 6070b4d1d99fSDavid Gibson goto out_mutex; 60712b26736cSAndy Whitcroft } 60725e911373SMike Kravetz /* Just decrements count, does not deallocate */ 6073285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 607457303d80SAndy Whitcroft 607529be8426SMiaohe Lin pagecache_page = find_lock_page(mapping, idx); 607657303d80SAndy Whitcroft } 607757303d80SAndy Whitcroft 60780f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 60790fe6e20bSNaoya Horiguchi 6080c89357e2SDavid Hildenbrand /* Check for a racing update before calling hugetlb_wp() */ 6081b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 6082cb900f41SKirill A. Shutemov goto out_ptl; 6083b4d1d99fSDavid Gibson 6084166f3eccSPeter Xu /* Handle userfault-wp first, before trying to lock more pages */ 6085166f3eccSPeter Xu if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) && 6086166f3eccSPeter Xu (flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 6087166f3eccSPeter Xu struct vm_fault vmf = { 6088166f3eccSPeter Xu .vma = vma, 6089166f3eccSPeter Xu .address = haddr, 6090166f3eccSPeter Xu .real_address = address, 6091166f3eccSPeter Xu .flags = flags, 6092166f3eccSPeter Xu }; 6093166f3eccSPeter Xu 6094166f3eccSPeter Xu spin_unlock(ptl); 6095166f3eccSPeter Xu if (pagecache_page) { 6096166f3eccSPeter Xu unlock_page(pagecache_page); 6097166f3eccSPeter Xu put_page(pagecache_page); 6098166f3eccSPeter Xu } 609940549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 6100166f3eccSPeter Xu mutex_unlock(&hugetlb_fault_mutex_table[hash]); 6101166f3eccSPeter Xu return handle_userfault(&vmf, VM_UFFD_WP); 6102166f3eccSPeter Xu } 6103166f3eccSPeter Xu 61040f792cf9SNaoya Horiguchi /* 6105c89357e2SDavid Hildenbrand * hugetlb_wp() requires page locks of pte_page(entry) and 61060f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 61070f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 61080f792cf9SNaoya Horiguchi */ 61090f792cf9SNaoya Horiguchi page = pte_page(entry); 61100f792cf9SNaoya Horiguchi if (page != pagecache_page) 61110f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 61120f792cf9SNaoya Horiguchi need_wait_lock = 1; 61130f792cf9SNaoya Horiguchi goto out_ptl; 61140f792cf9SNaoya Horiguchi } 61150f792cf9SNaoya Horiguchi 61160f792cf9SNaoya Horiguchi get_page(page); 6117b4d1d99fSDavid Gibson 6118c89357e2SDavid Hildenbrand if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) { 6119106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 6120c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, 6121cb900f41SKirill A. Shutemov pagecache_page, ptl); 61220f792cf9SNaoya Horiguchi goto out_put_page; 6123c89357e2SDavid Hildenbrand } else if (likely(flags & FAULT_FLAG_WRITE)) { 6124106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 6125b4d1d99fSDavid Gibson } 6126c89357e2SDavid Hildenbrand } 6127b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 6128285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 6129788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 6130285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 61310f792cf9SNaoya Horiguchi out_put_page: 61320f792cf9SNaoya Horiguchi if (page != pagecache_page) 61330f792cf9SNaoya Horiguchi unlock_page(page); 61340f792cf9SNaoya Horiguchi put_page(page); 6135cb900f41SKirill A. Shutemov out_ptl: 6136cb900f41SKirill A. Shutemov spin_unlock(ptl); 613757303d80SAndy Whitcroft 613857303d80SAndy Whitcroft if (pagecache_page) { 613957303d80SAndy Whitcroft unlock_page(pagecache_page); 614057303d80SAndy Whitcroft put_page(pagecache_page); 614157303d80SAndy Whitcroft } 6142b4d1d99fSDavid Gibson out_mutex: 614340549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 6144c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 61450f792cf9SNaoya Horiguchi /* 61460f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 61470f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 61480f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 61490f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 61500f792cf9SNaoya Horiguchi * here without taking refcount. 61510f792cf9SNaoya Horiguchi */ 61520f792cf9SNaoya Horiguchi if (need_wait_lock) 61530f792cf9SNaoya Horiguchi wait_on_page_locked(page); 61541e8f889bSDavid Gibson return ret; 615586e5216fSAdam Litke } 615686e5216fSAdam Litke 6157714c1891SAxel Rasmussen #ifdef CONFIG_USERFAULTFD 61588fb5debcSMike Kravetz /* 61598fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 61608fb5debcSMike Kravetz * modifications for huge pages. 61618fb5debcSMike Kravetz */ 61628fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 61638fb5debcSMike Kravetz pte_t *dst_pte, 61648fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 61658fb5debcSMike Kravetz unsigned long dst_addr, 61668fb5debcSMike Kravetz unsigned long src_addr, 6167f6191471SAxel Rasmussen enum mcopy_atomic_mode mode, 61686041c691SPeter Xu struct page **pagep, 61696041c691SPeter Xu bool wp_copy) 61708fb5debcSMike Kravetz { 6171f6191471SAxel Rasmussen bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE); 61728cc5fcbbSMina Almasry struct hstate *h = hstate_vma(dst_vma); 61738cc5fcbbSMina Almasry struct address_space *mapping = dst_vma->vm_file->f_mapping; 61748cc5fcbbSMina Almasry pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr); 61751e392147SAndrea Arcangeli unsigned long size; 61761c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 61778fb5debcSMike Kravetz pte_t _dst_pte; 61788fb5debcSMike Kravetz spinlock_t *ptl; 61798cc5fcbbSMina Almasry int ret = -ENOMEM; 61808fb5debcSMike Kravetz struct page *page; 6181f6191471SAxel Rasmussen int writable; 6182cc30042dSMina Almasry bool page_in_pagecache = false; 61838fb5debcSMike Kravetz 6184f6191471SAxel Rasmussen if (is_continue) { 6185f6191471SAxel Rasmussen ret = -EFAULT; 6186f6191471SAxel Rasmussen page = find_lock_page(mapping, idx); 6187f6191471SAxel Rasmussen if (!page) 6188f6191471SAxel Rasmussen goto out; 6189cc30042dSMina Almasry page_in_pagecache = true; 6190f6191471SAxel Rasmussen } else if (!*pagep) { 6191d84cf06eSMina Almasry /* If a page already exists, then it's UFFDIO_COPY for 6192d84cf06eSMina Almasry * a non-missing case. Return -EEXIST. 6193d84cf06eSMina Almasry */ 6194d84cf06eSMina Almasry if (vm_shared && 6195d84cf06eSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 6196d84cf06eSMina Almasry ret = -EEXIST; 61978fb5debcSMike Kravetz goto out; 6198d84cf06eSMina Almasry } 6199d84cf06eSMina Almasry 6200d84cf06eSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 6201d84cf06eSMina Almasry if (IS_ERR(page)) { 6202d84cf06eSMina Almasry ret = -ENOMEM; 6203d84cf06eSMina Almasry goto out; 6204d84cf06eSMina Almasry } 62058fb5debcSMike Kravetz 62068fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 62078fb5debcSMike Kravetz (const void __user *) src_addr, 6208810a56b9SMike Kravetz pages_per_huge_page(h), false); 62098fb5debcSMike Kravetz 6210c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 62118fb5debcSMike Kravetz if (unlikely(ret)) { 62129e368259SAndrea Arcangeli ret = -ENOENT; 62138cc5fcbbSMina Almasry /* Free the allocated page which may have 62148cc5fcbbSMina Almasry * consumed a reservation. 62158cc5fcbbSMina Almasry */ 62168cc5fcbbSMina Almasry restore_reserve_on_error(h, dst_vma, dst_addr, page); 62178cc5fcbbSMina Almasry put_page(page); 62188cc5fcbbSMina Almasry 62198cc5fcbbSMina Almasry /* Allocate a temporary page to hold the copied 62208cc5fcbbSMina Almasry * contents. 62218cc5fcbbSMina Almasry */ 62228cc5fcbbSMina Almasry page = alloc_huge_page_vma(h, dst_vma, dst_addr); 62238cc5fcbbSMina Almasry if (!page) { 62248cc5fcbbSMina Almasry ret = -ENOMEM; 62258cc5fcbbSMina Almasry goto out; 62268cc5fcbbSMina Almasry } 62278fb5debcSMike Kravetz *pagep = page; 62288cc5fcbbSMina Almasry /* Set the outparam pagep and return to the caller to 62298cc5fcbbSMina Almasry * copy the contents outside the lock. Don't free the 62308cc5fcbbSMina Almasry * page. 62318cc5fcbbSMina Almasry */ 62328fb5debcSMike Kravetz goto out; 62338fb5debcSMike Kravetz } 62348fb5debcSMike Kravetz } else { 62358cc5fcbbSMina Almasry if (vm_shared && 62368cc5fcbbSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 62378cc5fcbbSMina Almasry put_page(*pagep); 62388cc5fcbbSMina Almasry ret = -EEXIST; 62398cc5fcbbSMina Almasry *pagep = NULL; 62408cc5fcbbSMina Almasry goto out; 62418cc5fcbbSMina Almasry } 62428cc5fcbbSMina Almasry 62438cc5fcbbSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 62448cc5fcbbSMina Almasry if (IS_ERR(page)) { 6245da9a298fSMiaohe Lin put_page(*pagep); 62468cc5fcbbSMina Almasry ret = -ENOMEM; 62478cc5fcbbSMina Almasry *pagep = NULL; 62488cc5fcbbSMina Almasry goto out; 62498cc5fcbbSMina Almasry } 625034892366SMuchun Song copy_user_huge_page(page, *pagep, dst_addr, dst_vma, 625134892366SMuchun Song pages_per_huge_page(h)); 62528cc5fcbbSMina Almasry put_page(*pagep); 62538fb5debcSMike Kravetz *pagep = NULL; 62548fb5debcSMike Kravetz } 62558fb5debcSMike Kravetz 62568fb5debcSMike Kravetz /* 62578fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 62588fb5debcSMike Kravetz * preceding stores to the page contents become visible before 62598fb5debcSMike Kravetz * the set_pte_at() write. 62608fb5debcSMike Kravetz */ 62618fb5debcSMike Kravetz __SetPageUptodate(page); 62628fb5debcSMike Kravetz 6263f6191471SAxel Rasmussen /* Add shared, newly allocated pages to the page cache. */ 6264f6191471SAxel Rasmussen if (vm_shared && !is_continue) { 62651e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 62661e392147SAndrea Arcangeli ret = -EFAULT; 62671e392147SAndrea Arcangeli if (idx >= size) 62681e392147SAndrea Arcangeli goto out_release_nounlock; 62691c9e8defSMike Kravetz 62701e392147SAndrea Arcangeli /* 62711e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 62727e1813d4SMike Kravetz * hugetlb_add_to_page_cache() below happens through the 62731e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 62741e392147SAndrea Arcangeli * the caller. 62751e392147SAndrea Arcangeli */ 62767e1813d4SMike Kravetz ret = hugetlb_add_to_page_cache(page, mapping, idx); 62771c9e8defSMike Kravetz if (ret) 62781c9e8defSMike Kravetz goto out_release_nounlock; 6279cc30042dSMina Almasry page_in_pagecache = true; 62801c9e8defSMike Kravetz } 62811c9e8defSMike Kravetz 6282bcc66543SMiaohe Lin ptl = huge_pte_lock(h, dst_mm, dst_pte); 62838fb5debcSMike Kravetz 62848625147cSJames Houghton ret = -EIO; 62858625147cSJames Houghton if (PageHWPoison(page)) 62868625147cSJames Houghton goto out_release_unlock; 62878625147cSJames Houghton 62881e392147SAndrea Arcangeli /* 62896041c691SPeter Xu * We allow to overwrite a pte marker: consider when both MISSING|WP 62906041c691SPeter Xu * registered, we firstly wr-protect a none pte which has no page cache 62916041c691SPeter Xu * page backing it, then access the page. 62926041c691SPeter Xu */ 6293fa27759aSMike Kravetz ret = -EEXIST; 62946041c691SPeter Xu if (!huge_pte_none_mostly(huge_ptep_get(dst_pte))) 62958fb5debcSMike Kravetz goto out_release_unlock; 62968fb5debcSMike Kravetz 62974781593dSPeter Xu if (page_in_pagecache) 6298fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 62994781593dSPeter Xu else 63008fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 63018fb5debcSMike Kravetz 63026041c691SPeter Xu /* 63036041c691SPeter Xu * For either: (1) CONTINUE on a non-shared VMA, or (2) UFFDIO_COPY 63046041c691SPeter Xu * with wp flag set, don't set pte write bit. 63056041c691SPeter Xu */ 63066041c691SPeter Xu if (wp_copy || (is_continue && !vm_shared)) 6307f6191471SAxel Rasmussen writable = 0; 6308f6191471SAxel Rasmussen else 6309f6191471SAxel Rasmussen writable = dst_vma->vm_flags & VM_WRITE; 6310f6191471SAxel Rasmussen 6311f6191471SAxel Rasmussen _dst_pte = make_huge_pte(dst_vma, page, writable); 63126041c691SPeter Xu /* 63136041c691SPeter Xu * Always mark UFFDIO_COPY page dirty; note that this may not be 63146041c691SPeter Xu * extremely important for hugetlbfs for now since swapping is not 63156041c691SPeter Xu * supported, but we should still be clear in that this page cannot be 63166041c691SPeter Xu * thrown away at will, even if write bit not set. 63176041c691SPeter Xu */ 63188fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 63198fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 63208fb5debcSMike Kravetz 63216041c691SPeter Xu if (wp_copy) 63226041c691SPeter Xu _dst_pte = huge_pte_mkuffd_wp(_dst_pte); 63236041c691SPeter Xu 63248fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 63258fb5debcSMike Kravetz 63268fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 63278fb5debcSMike Kravetz 63288fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 63298fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 63308fb5debcSMike Kravetz 63318fb5debcSMike Kravetz spin_unlock(ptl); 6332f6191471SAxel Rasmussen if (!is_continue) 63338f251a3dSMike Kravetz SetHPageMigratable(page); 6334f6191471SAxel Rasmussen if (vm_shared || is_continue) 63351c9e8defSMike Kravetz unlock_page(page); 63368fb5debcSMike Kravetz ret = 0; 63378fb5debcSMike Kravetz out: 63388fb5debcSMike Kravetz return ret; 63398fb5debcSMike Kravetz out_release_unlock: 63408fb5debcSMike Kravetz spin_unlock(ptl); 6341f6191471SAxel Rasmussen if (vm_shared || is_continue) 63421c9e8defSMike Kravetz unlock_page(page); 63435af10dfdSAndrea Arcangeli out_release_nounlock: 6344cc30042dSMina Almasry if (!page_in_pagecache) 6345846be085SMike Kravetz restore_reserve_on_error(h, dst_vma, dst_addr, page); 63468fb5debcSMike Kravetz put_page(page); 63478fb5debcSMike Kravetz goto out; 63488fb5debcSMike Kravetz } 6349714c1891SAxel Rasmussen #endif /* CONFIG_USERFAULTFD */ 63508fb5debcSMike Kravetz 635182e5d378SJoao Martins static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, 635282e5d378SJoao Martins int refs, struct page **pages, 635382e5d378SJoao Martins struct vm_area_struct **vmas) 635482e5d378SJoao Martins { 635582e5d378SJoao Martins int nr; 635682e5d378SJoao Martins 635782e5d378SJoao Martins for (nr = 0; nr < refs; nr++) { 635882e5d378SJoao Martins if (likely(pages)) 635914455eabSCheng Li pages[nr] = nth_page(page, nr); 636082e5d378SJoao Martins if (vmas) 636182e5d378SJoao Martins vmas[nr] = vma; 636282e5d378SJoao Martins } 636382e5d378SJoao Martins } 636482e5d378SJoao Martins 636584209e87SDavid Hildenbrand static inline bool __follow_hugetlb_must_fault(struct vm_area_struct *vma, 636684209e87SDavid Hildenbrand unsigned int flags, pte_t *pte, 6367a7f22660SDavid Hildenbrand bool *unshare) 6368a7f22660SDavid Hildenbrand { 6369a7f22660SDavid Hildenbrand pte_t pteval = huge_ptep_get(pte); 6370a7f22660SDavid Hildenbrand 6371a7f22660SDavid Hildenbrand *unshare = false; 6372a7f22660SDavid Hildenbrand if (is_swap_pte(pteval)) 6373a7f22660SDavid Hildenbrand return true; 6374a7f22660SDavid Hildenbrand if (huge_pte_write(pteval)) 6375a7f22660SDavid Hildenbrand return false; 6376a7f22660SDavid Hildenbrand if (flags & FOLL_WRITE) 6377a7f22660SDavid Hildenbrand return true; 637884209e87SDavid Hildenbrand if (gup_must_unshare(vma, flags, pte_page(pteval))) { 6379a7f22660SDavid Hildenbrand *unshare = true; 6380a7f22660SDavid Hildenbrand return true; 6381a7f22660SDavid Hildenbrand } 6382a7f22660SDavid Hildenbrand return false; 6383a7f22660SDavid Hildenbrand } 6384a7f22660SDavid Hildenbrand 638557a196a5SMike Kravetz struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, 638657a196a5SMike Kravetz unsigned long address, unsigned int flags) 638757a196a5SMike Kravetz { 638857a196a5SMike Kravetz struct hstate *h = hstate_vma(vma); 638957a196a5SMike Kravetz struct mm_struct *mm = vma->vm_mm; 639057a196a5SMike Kravetz unsigned long haddr = address & huge_page_mask(h); 639157a196a5SMike Kravetz struct page *page = NULL; 639257a196a5SMike Kravetz spinlock_t *ptl; 639357a196a5SMike Kravetz pte_t *pte, entry; 639457a196a5SMike Kravetz 639557a196a5SMike Kravetz /* 639657a196a5SMike Kravetz * FOLL_PIN is not supported for follow_page(). Ordinary GUP goes via 639757a196a5SMike Kravetz * follow_hugetlb_page(). 639857a196a5SMike Kravetz */ 639957a196a5SMike Kravetz if (WARN_ON_ONCE(flags & FOLL_PIN)) 640057a196a5SMike Kravetz return NULL; 640157a196a5SMike Kravetz 640257a196a5SMike Kravetz retry: 640357a196a5SMike Kravetz pte = huge_pte_offset(mm, haddr, huge_page_size(h)); 640457a196a5SMike Kravetz if (!pte) 640557a196a5SMike Kravetz return NULL; 640657a196a5SMike Kravetz 640757a196a5SMike Kravetz ptl = huge_pte_lock(h, mm, pte); 640857a196a5SMike Kravetz entry = huge_ptep_get(pte); 640957a196a5SMike Kravetz if (pte_present(entry)) { 641057a196a5SMike Kravetz page = pte_page(entry) + 641157a196a5SMike Kravetz ((address & ~huge_page_mask(h)) >> PAGE_SHIFT); 641257a196a5SMike Kravetz /* 641357a196a5SMike Kravetz * Note that page may be a sub-page, and with vmemmap 641457a196a5SMike Kravetz * optimizations the page struct may be read only. 641557a196a5SMike Kravetz * try_grab_page() will increase the ref count on the 641657a196a5SMike Kravetz * head page, so this will be OK. 641757a196a5SMike Kravetz * 6418e2ca6ba6SLinus Torvalds * try_grab_page() should always be able to get the page here, 6419e2ca6ba6SLinus Torvalds * because we hold the ptl lock and have verified pte_present(). 642057a196a5SMike Kravetz */ 6421e2ca6ba6SLinus Torvalds if (try_grab_page(page, flags)) { 642257a196a5SMike Kravetz page = NULL; 642357a196a5SMike Kravetz goto out; 642457a196a5SMike Kravetz } 642557a196a5SMike Kravetz } else { 642657a196a5SMike Kravetz if (is_hugetlb_entry_migration(entry)) { 642757a196a5SMike Kravetz spin_unlock(ptl); 642857a196a5SMike Kravetz __migration_entry_wait_huge(pte, ptl); 642957a196a5SMike Kravetz goto retry; 643057a196a5SMike Kravetz } 643157a196a5SMike Kravetz /* 643257a196a5SMike Kravetz * hwpoisoned entry is treated as no_page_table in 643357a196a5SMike Kravetz * follow_page_mask(). 643457a196a5SMike Kravetz */ 643557a196a5SMike Kravetz } 643657a196a5SMike Kravetz out: 643757a196a5SMike Kravetz spin_unlock(ptl); 643857a196a5SMike Kravetz return page; 643957a196a5SMike Kravetz } 644057a196a5SMike Kravetz 644128a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 644263551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 644328a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 64444f6da934SPeter Xu long i, unsigned int flags, int *locked) 644563551ae0SDavid Gibson { 6446d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 6447d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 644828a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 6449a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 64500fa5bc40SJoao Martins int err = -EFAULT, refs; 645163551ae0SDavid Gibson 645263551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 645363551ae0SDavid Gibson pte_t *pte; 6454cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 6455a7f22660SDavid Hildenbrand bool unshare = false; 64562a15efc9SHugh Dickins int absent; 645763551ae0SDavid Gibson struct page *page; 645863551ae0SDavid Gibson 64594c887265SAdam Litke /* 646002057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 646102057967SDavid Rientjes * potentially allocating memory. 646202057967SDavid Rientjes */ 6463fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 646402057967SDavid Rientjes remainder = 0; 646502057967SDavid Rientjes break; 646602057967SDavid Rientjes } 646702057967SDavid Rientjes 646802057967SDavid Rientjes /* 64694c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 64702a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 64714c887265SAdam Litke * first, for the page indexing below to work. 6472cb900f41SKirill A. Shutemov * 6473cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 64744c887265SAdam Litke */ 64757868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 64767868a208SPunit Agrawal huge_page_size(h)); 6477cb900f41SKirill A. Shutemov if (pte) 6478cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 64792a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 648063551ae0SDavid Gibson 64812a15efc9SHugh Dickins /* 64822a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 64833ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 64843ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 64853ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 64863ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 64872a15efc9SHugh Dickins */ 64883ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 64893ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 6490cb900f41SKirill A. Shutemov if (pte) 6491cb900f41SKirill A. Shutemov spin_unlock(ptl); 64922a15efc9SHugh Dickins remainder = 0; 64932a15efc9SHugh Dickins break; 64942a15efc9SHugh Dickins } 64952a15efc9SHugh Dickins 64969cc3a5bdSNaoya Horiguchi /* 64979cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 64989cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 64999cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 65009cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 65019cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 65029cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 65039cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 65049cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 65059cc3a5bdSNaoya Horiguchi */ 6506a7f22660SDavid Hildenbrand if (absent || 650784209e87SDavid Hildenbrand __follow_hugetlb_must_fault(vma, flags, pte, &unshare)) { 65082b740303SSouptick Joarder vm_fault_t ret; 650987ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 65104c887265SAdam Litke 6511cb900f41SKirill A. Shutemov if (pte) 6512cb900f41SKirill A. Shutemov spin_unlock(ptl); 651387ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 651487ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 6515a7f22660SDavid Hildenbrand else if (unshare) 6516a7f22660SDavid Hildenbrand fault_flags |= FAULT_FLAG_UNSHARE; 651793c5c61dSPeter Xu if (locked) { 651871335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 651971335f37SPeter Xu FAULT_FLAG_KILLABLE; 652093c5c61dSPeter Xu if (flags & FOLL_INTERRUPTIBLE) 652193c5c61dSPeter Xu fault_flags |= FAULT_FLAG_INTERRUPTIBLE; 652293c5c61dSPeter Xu } 652387ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 652487ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 652587ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 652687ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 65274426e945SPeter Xu /* 65284426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 65294426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 65304426e945SPeter Xu */ 653187ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 653287ffc118SAndrea Arcangeli } 653387ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 653487ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 65352be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 65361c59827dSHugh Dickins remainder = 0; 65371c59827dSHugh Dickins break; 65381c59827dSHugh Dickins } 653987ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 65404f6da934SPeter Xu if (locked && 65411ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 65424f6da934SPeter Xu *locked = 0; 654387ffc118SAndrea Arcangeli *nr_pages = 0; 654487ffc118SAndrea Arcangeli /* 654587ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 654687ffc118SAndrea Arcangeli * error, it will return zero 654787ffc118SAndrea Arcangeli * instead. 654887ffc118SAndrea Arcangeli * 654987ffc118SAndrea Arcangeli * No need to update "position" as the 655087ffc118SAndrea Arcangeli * caller will not check it after 655187ffc118SAndrea Arcangeli * *nr_pages is set to 0. 655287ffc118SAndrea Arcangeli */ 655387ffc118SAndrea Arcangeli return i; 655487ffc118SAndrea Arcangeli } 655587ffc118SAndrea Arcangeli continue; 655687ffc118SAndrea Arcangeli } 655763551ae0SDavid Gibson 6558a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 65597f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 65608fde12caSLinus Torvalds 6561b6a2619cSDavid Hildenbrand VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && 6562b6a2619cSDavid Hildenbrand !PageAnonExclusive(page), page); 6563b6a2619cSDavid Hildenbrand 65648fde12caSLinus Torvalds /* 6565acbfb087SZhigang Lu * If subpage information not requested, update counters 6566acbfb087SZhigang Lu * and skip the same_page loop below. 6567acbfb087SZhigang Lu */ 6568acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 6569acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 6570acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 6571acbfb087SZhigang Lu vaddr += huge_page_size(h); 6572acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 6573acbfb087SZhigang Lu i += pages_per_huge_page(h); 6574acbfb087SZhigang Lu spin_unlock(ptl); 6575acbfb087SZhigang Lu continue; 6576acbfb087SZhigang Lu } 6577acbfb087SZhigang Lu 6578d08af0a5SJoao Martins /* vaddr may not be aligned to PAGE_SIZE */ 6579d08af0a5SJoao Martins refs = min3(pages_per_huge_page(h) - pfn_offset, remainder, 6580d08af0a5SJoao Martins (vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT); 65810fa5bc40SJoao Martins 658282e5d378SJoao Martins if (pages || vmas) 658314455eabSCheng Li record_subpages_vmas(nth_page(page, pfn_offset), 658482e5d378SJoao Martins vma, refs, 658582e5d378SJoao Martins likely(pages) ? pages + i : NULL, 658682e5d378SJoao Martins vmas ? vmas + i : NULL); 658763551ae0SDavid Gibson 658882e5d378SJoao Martins if (pages) { 65890fa5bc40SJoao Martins /* 6590822951d8SMatthew Wilcox (Oracle) * try_grab_folio() should always succeed here, 65910fa5bc40SJoao Martins * because: a) we hold the ptl lock, and b) we've just 65920fa5bc40SJoao Martins * checked that the huge page is present in the page 65930fa5bc40SJoao Martins * tables. If the huge page is present, then the tail 65940fa5bc40SJoao Martins * pages must also be present. The ptl prevents the 65950fa5bc40SJoao Martins * head page and tail pages from being rearranged in 65964003f107SLogan Gunthorpe * any way. As this is hugetlb, the pages will never 65974003f107SLogan Gunthorpe * be p2pdma or not longterm pinable. So this page 65984003f107SLogan Gunthorpe * must be available at this point, unless the page 65994003f107SLogan Gunthorpe * refcount overflowed: 66000fa5bc40SJoao Martins */ 6601822951d8SMatthew Wilcox (Oracle) if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs, 66020fa5bc40SJoao Martins flags))) { 66030fa5bc40SJoao Martins spin_unlock(ptl); 66040fa5bc40SJoao Martins remainder = 0; 66050fa5bc40SJoao Martins err = -ENOMEM; 66060fa5bc40SJoao Martins break; 66070fa5bc40SJoao Martins } 6608d5d4b0aaSChen, Kenneth W } 660982e5d378SJoao Martins 661082e5d378SJoao Martins vaddr += (refs << PAGE_SHIFT); 661182e5d378SJoao Martins remainder -= refs; 661282e5d378SJoao Martins i += refs; 661382e5d378SJoao Martins 6614cb900f41SKirill A. Shutemov spin_unlock(ptl); 661563551ae0SDavid Gibson } 661628a35716SMichel Lespinasse *nr_pages = remainder; 661787ffc118SAndrea Arcangeli /* 661887ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 661987ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 662087ffc118SAndrea Arcangeli * branch. 662187ffc118SAndrea Arcangeli */ 662263551ae0SDavid Gibson *position = vaddr; 662363551ae0SDavid Gibson 66242be7cfedSDaniel Jordan return i ? i : err; 662563551ae0SDavid Gibson } 66268f860591SZhang, Yanmin 66277da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 66285a90d5a1SPeter Xu unsigned long address, unsigned long end, 66295a90d5a1SPeter Xu pgprot_t newprot, unsigned long cp_flags) 66308f860591SZhang, Yanmin { 66318f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 66328f860591SZhang, Yanmin unsigned long start = address; 66338f860591SZhang, Yanmin pte_t *ptep; 66348f860591SZhang, Yanmin pte_t pte; 6635a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 663660dfaad6SPeter Xu unsigned long pages = 0, psize = huge_page_size(h); 6637dff11abeSMike Kravetz bool shared_pmd = false; 6638ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 6639e95a9851SMike Kravetz unsigned long last_addr_mask; 66405a90d5a1SPeter Xu bool uffd_wp = cp_flags & MM_CP_UFFD_WP; 66415a90d5a1SPeter Xu bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; 6642dff11abeSMike Kravetz 6643dff11abeSMike Kravetz /* 6644dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 6645ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 6646dff11abeSMike Kravetz * range if PMD sharing is possible. 6647dff11abeSMike Kravetz */ 66487269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 66497269f999SJérôme Glisse 0, vma, mm, start, end); 6650ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 66518f860591SZhang, Yanmin 66528f860591SZhang, Yanmin BUG_ON(address >= end); 6653ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 66548f860591SZhang, Yanmin 6655ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 665640549ba8SMike Kravetz hugetlb_vma_lock_write(vma); 665783cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 665840549ba8SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 665960dfaad6SPeter Xu for (; address < end; address += psize) { 6660cb900f41SKirill A. Shutemov spinlock_t *ptl; 666160dfaad6SPeter Xu ptep = huge_pte_offset(mm, address, psize); 6662e95a9851SMike Kravetz if (!ptep) { 6663fed15f13SPeter Xu if (!uffd_wp) { 6664e95a9851SMike Kravetz address |= last_addr_mask; 66658f860591SZhang, Yanmin continue; 6666e95a9851SMike Kravetz } 6667fed15f13SPeter Xu /* 6668fed15f13SPeter Xu * Userfaultfd wr-protect requires pgtable 6669fed15f13SPeter Xu * pre-allocations to install pte markers. 6670fed15f13SPeter Xu */ 6671fed15f13SPeter Xu ptep = huge_pte_alloc(mm, vma, address, psize); 6672fed15f13SPeter Xu if (!ptep) 6673fed15f13SPeter Xu break; 6674fed15f13SPeter Xu } 6675cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 66764ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, address, ptep)) { 667760dfaad6SPeter Xu /* 667860dfaad6SPeter Xu * When uffd-wp is enabled on the vma, unshare 667960dfaad6SPeter Xu * shouldn't happen at all. Warn about it if it 668060dfaad6SPeter Xu * happened due to some reason. 668160dfaad6SPeter Xu */ 668260dfaad6SPeter Xu WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); 66837da4d641SPeter Zijlstra pages++; 6684cb900f41SKirill A. Shutemov spin_unlock(ptl); 6685dff11abeSMike Kravetz shared_pmd = true; 66864ddb4d91SMike Kravetz address |= last_addr_mask; 668739dde65cSChen, Kenneth W continue; 66887da4d641SPeter Zijlstra } 6689a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 6690a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 66910e678153SDavid Hildenbrand /* Nothing to do. */ 66920e678153SDavid Hildenbrand } else if (unlikely(is_hugetlb_entry_migration(pte))) { 6693a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 66946c287605SDavid Hildenbrand struct page *page = pfn_swap_entry_to_page(entry); 669544f86392SDavid Hildenbrand pte_t newpte = pte; 6696a8bda28dSNaoya Horiguchi 669744f86392SDavid Hildenbrand if (is_writable_migration_entry(entry)) { 66986c287605SDavid Hildenbrand if (PageAnon(page)) 66996c287605SDavid Hildenbrand entry = make_readable_exclusive_migration_entry( 67006c287605SDavid Hildenbrand swp_offset(entry)); 67016c287605SDavid Hildenbrand else 67024dd845b5SAlistair Popple entry = make_readable_migration_entry( 67034dd845b5SAlistair Popple swp_offset(entry)); 6704a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 670544f86392SDavid Hildenbrand pages++; 670644f86392SDavid Hildenbrand } 670744f86392SDavid Hildenbrand 67085a90d5a1SPeter Xu if (uffd_wp) 67095a90d5a1SPeter Xu newpte = pte_swp_mkuffd_wp(newpte); 67105a90d5a1SPeter Xu else if (uffd_wp_resolve) 67115a90d5a1SPeter Xu newpte = pte_swp_clear_uffd_wp(newpte); 671244f86392SDavid Hildenbrand if (!pte_same(pte, newpte)) 671318f39629SQi Zheng set_huge_pte_at(mm, address, ptep, newpte); 67140e678153SDavid Hildenbrand } else if (unlikely(is_pte_marker(pte))) { 67150e678153SDavid Hildenbrand /* No other markers apply for now. */ 67160e678153SDavid Hildenbrand WARN_ON_ONCE(!pte_marker_uffd_wp(pte)); 671760dfaad6SPeter Xu if (uffd_wp_resolve) 67180e678153SDavid Hildenbrand /* Safe to modify directly (non-present->none). */ 671960dfaad6SPeter Xu huge_pte_clear(mm, address, ptep, psize); 67200e678153SDavid Hildenbrand } else if (!huge_pte_none(pte)) { 6721023bdd00SAneesh Kumar K.V pte_t old_pte; 672279c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 6723023bdd00SAneesh Kumar K.V 6724023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 672516785bd7SAnshuman Khandual pte = huge_pte_modify(old_pte, newprot); 672679c1c594SChristophe Leroy pte = arch_make_huge_pte(pte, shift, vma->vm_flags); 67275a90d5a1SPeter Xu if (uffd_wp) 67285a90d5a1SPeter Xu pte = huge_pte_mkuffd_wp(huge_pte_wrprotect(pte)); 67295a90d5a1SPeter Xu else if (uffd_wp_resolve) 67305a90d5a1SPeter Xu pte = huge_pte_clear_uffd_wp(pte); 6731023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 67327da4d641SPeter Zijlstra pages++; 673360dfaad6SPeter Xu } else { 673460dfaad6SPeter Xu /* None pte */ 673560dfaad6SPeter Xu if (unlikely(uffd_wp)) 673660dfaad6SPeter Xu /* Safe to modify directly (none->non-present). */ 673760dfaad6SPeter Xu set_huge_pte_at(mm, address, ptep, 673860dfaad6SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 67398f860591SZhang, Yanmin } 6740cb900f41SKirill A. Shutemov spin_unlock(ptl); 67418f860591SZhang, Yanmin } 6742d833352aSMel Gorman /* 6743c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 6744d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 6745c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 6746dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 6747dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 6748d833352aSMel Gorman */ 6749dff11abeSMike Kravetz if (shared_pmd) 6750ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 6751dff11abeSMike Kravetz else 67525491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 67530f10851eSJérôme Glisse /* 67540f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 67550f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 67560f10851eSJérôme Glisse * 6757ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 67580f10851eSJérôme Glisse */ 675983cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 676040549ba8SMike Kravetz hugetlb_vma_unlock_write(vma); 6761ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 67627da4d641SPeter Zijlstra 67637da4d641SPeter Zijlstra return pages << h->order; 67648f860591SZhang, Yanmin } 67658f860591SZhang, Yanmin 676633b8f84aSMike Kravetz /* Return true if reservation was successful, false otherwise. */ 676733b8f84aSMike Kravetz bool hugetlb_reserve_pages(struct inode *inode, 6768a1e78772SMel Gorman long from, long to, 67695a6fe125SMel Gorman struct vm_area_struct *vma, 6770ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 6771e4e574b7SAdam Litke { 677233b8f84aSMike Kravetz long chg, add = -1; 6773a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 677490481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 67759119a41eSJoonsoo Kim struct resv_map *resv_map; 6776075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 67770db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 6778e4e574b7SAdam Litke 677963489f8eSMike Kravetz /* This should never happen */ 678063489f8eSMike Kravetz if (from > to) { 678163489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 678233b8f84aSMike Kravetz return false; 678363489f8eSMike Kravetz } 678463489f8eSMike Kravetz 6785a1e78772SMel Gorman /* 6786e700898fSMike Kravetz * vma specific semaphore used for pmd sharing and fault/truncation 6787e700898fSMike Kravetz * synchronization 67888d9bfb26SMike Kravetz */ 67898d9bfb26SMike Kravetz hugetlb_vma_lock_alloc(vma); 67908d9bfb26SMike Kravetz 67918d9bfb26SMike Kravetz /* 679217c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 679317c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 679490481622SDavid Gibson * without using reserves 679517c9d12eSMel Gorman */ 6796ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 679733b8f84aSMike Kravetz return true; 679817c9d12eSMel Gorman 679917c9d12eSMel Gorman /* 6800a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 6801a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 6802a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 6803a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 6804a1e78772SMel Gorman */ 68059119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 6806f27a5136SMike Kravetz /* 6807f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 6808f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 6809f27a5136SMike Kravetz * hugetlbfs_get_inode). 6810f27a5136SMike Kravetz */ 68114e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 68129119a41eSJoonsoo Kim 68130db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 68149119a41eSJoonsoo Kim } else { 6815e9fe92aeSMina Almasry /* Private mapping. */ 68169119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 68175a6fe125SMel Gorman if (!resv_map) 68188d9bfb26SMike Kravetz goto out_err; 68195a6fe125SMel Gorman 682017c9d12eSMel Gorman chg = to - from; 682117c9d12eSMel Gorman 68225a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 68235a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 68245a6fe125SMel Gorman } 68255a6fe125SMel Gorman 682633b8f84aSMike Kravetz if (chg < 0) 6827c50ac050SDave Hansen goto out_err; 682817c9d12eSMel Gorman 682933b8f84aSMike Kravetz if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h), 683033b8f84aSMike Kravetz chg * pages_per_huge_page(h), &h_cg) < 0) 6831075a61d0SMina Almasry goto out_err; 6832075a61d0SMina Almasry 6833075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 6834075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 6835075a61d0SMina Almasry * of the resv_map. 6836075a61d0SMina Almasry */ 6837075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 6838075a61d0SMina Almasry } 6839075a61d0SMina Almasry 68401c5ecae3SMike Kravetz /* 68411c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 68421c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 68431c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 68441c5ecae3SMike Kravetz */ 68451c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 684633b8f84aSMike Kravetz if (gbl_reserve < 0) 6847075a61d0SMina Almasry goto out_uncharge_cgroup; 684817c9d12eSMel Gorman 684917c9d12eSMel Gorman /* 685017c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 685190481622SDavid Gibson * Hand the pages back to the subpool if there are not 685217c9d12eSMel Gorman */ 685333b8f84aSMike Kravetz if (hugetlb_acct_memory(h, gbl_reserve) < 0) 6854075a61d0SMina Almasry goto out_put_pages; 685517c9d12eSMel Gorman 685617c9d12eSMel Gorman /* 685717c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 685817c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 685917c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 686017c9d12eSMel Gorman * the reservation was and the page cache tells how much of 686117c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 686217c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 686317c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 686417c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 686517c9d12eSMel Gorman * else has to be done for private mappings here 686617c9d12eSMel Gorman */ 686733039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 6868075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 686933039678SMike Kravetz 68700db9d74eSMina Almasry if (unlikely(add < 0)) { 68710db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 6872075a61d0SMina Almasry goto out_put_pages; 68730db9d74eSMina Almasry } else if (unlikely(chg > add)) { 687433039678SMike Kravetz /* 687533039678SMike Kravetz * pages in this range were added to the reserve 687633039678SMike Kravetz * map between region_chg and region_add. This 687733039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 687833039678SMike Kravetz * the subpool and reserve counts modified above 687933039678SMike Kravetz * based on the difference. 688033039678SMike Kravetz */ 688133039678SMike Kravetz long rsv_adjust; 688233039678SMike Kravetz 6883d85aecf2SMiaohe Lin /* 6884d85aecf2SMiaohe Lin * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the 6885d85aecf2SMiaohe Lin * reference to h_cg->css. See comment below for detail. 6886d85aecf2SMiaohe Lin */ 6887075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 6888075a61d0SMina Almasry hstate_index(h), 6889075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 6890075a61d0SMina Almasry 689133039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 689233039678SMike Kravetz chg - add); 689333039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 6894d85aecf2SMiaohe Lin } else if (h_cg) { 6895d85aecf2SMiaohe Lin /* 6896d85aecf2SMiaohe Lin * The file_regions will hold their own reference to 6897d85aecf2SMiaohe Lin * h_cg->css. So we should release the reference held 6898d85aecf2SMiaohe Lin * via hugetlb_cgroup_charge_cgroup_rsvd() when we are 6899d85aecf2SMiaohe Lin * done. 6900d85aecf2SMiaohe Lin */ 6901d85aecf2SMiaohe Lin hugetlb_cgroup_put_rsvd_cgroup(h_cg); 690233039678SMike Kravetz } 690333039678SMike Kravetz } 690433b8f84aSMike Kravetz return true; 690533b8f84aSMike Kravetz 6906075a61d0SMina Almasry out_put_pages: 6907075a61d0SMina Almasry /* put back original number of pages, chg */ 6908075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 6909075a61d0SMina Almasry out_uncharge_cgroup: 6910075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 6911075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 6912c50ac050SDave Hansen out_err: 69138d9bfb26SMike Kravetz hugetlb_vma_lock_free(vma); 69145e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 69150db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 69160db9d74eSMina Almasry * region_add failed or didn't run. 69170db9d74eSMina Almasry */ 69180db9d74eSMina Almasry if (chg >= 0 && add < 0) 69190db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 6920f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 6921f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 692233b8f84aSMike Kravetz return false; 6923a43a8c39SChen, Kenneth W } 6924a43a8c39SChen, Kenneth W 6925b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 6926b5cec28dSMike Kravetz long freed) 6927a43a8c39SChen, Kenneth W { 6928a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 69294e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 69309119a41eSJoonsoo Kim long chg = 0; 693190481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 69321c5ecae3SMike Kravetz long gbl_reserve; 693345c682a6SKen Chen 6934f27a5136SMike Kravetz /* 6935f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 6936f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 6937f27a5136SMike Kravetz */ 6938b5cec28dSMike Kravetz if (resv_map) { 6939b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 6940b5cec28dSMike Kravetz /* 6941b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 6942b5cec28dSMike Kravetz * must be split and another region descriptor can not be 6943b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 6944b5cec28dSMike Kravetz */ 6945b5cec28dSMike Kravetz if (chg < 0) 6946b5cec28dSMike Kravetz return chg; 6947b5cec28dSMike Kravetz } 6948b5cec28dSMike Kravetz 694945c682a6SKen Chen spin_lock(&inode->i_lock); 6950e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 695145c682a6SKen Chen spin_unlock(&inode->i_lock); 695245c682a6SKen Chen 69531c5ecae3SMike Kravetz /* 69541c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 69551c5ecae3SMike Kravetz * reservations to be released may be adjusted. 6956dddf31a4SMiaohe Lin * 6957dddf31a4SMiaohe Lin * Note that !resv_map implies freed == 0. So (chg - freed) 6958dddf31a4SMiaohe Lin * won't go negative. 69591c5ecae3SMike Kravetz */ 69601c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 69611c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 6962b5cec28dSMike Kravetz 6963b5cec28dSMike Kravetz return 0; 6964a43a8c39SChen, Kenneth W } 696593f70f90SNaoya Horiguchi 69663212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 69673212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 69683212b535SSteve Capper struct vm_area_struct *vma, 69693212b535SSteve Capper unsigned long addr, pgoff_t idx) 69703212b535SSteve Capper { 69713212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 69723212b535SSteve Capper svma->vm_start; 69733212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 69743212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 69753212b535SSteve Capper 69763212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 6977de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 6978de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 69793212b535SSteve Capper 69803212b535SSteve Capper /* 69813212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 69823212b535SSteve Capper * page table page. 6983131a79b4SMike Kravetz * 6984131a79b4SMike Kravetz * Also, vma_lock (vm_private_data) is required for sharing. 69853212b535SSteve Capper */ 69863212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 69873212b535SSteve Capper vm_flags != svm_flags || 6988131a79b4SMike Kravetz !range_in_vma(svma, sbase, s_end) || 6989131a79b4SMike Kravetz !svma->vm_private_data) 69903212b535SSteve Capper return 0; 69913212b535SSteve Capper 69923212b535SSteve Capper return saddr; 69933212b535SSteve Capper } 69943212b535SSteve Capper 6995bbff39ccSMike Kravetz bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 69963212b535SSteve Capper { 6997bbff39ccSMike Kravetz unsigned long start = addr & PUD_MASK; 6998bbff39ccSMike Kravetz unsigned long end = start + PUD_SIZE; 6999bbff39ccSMike Kravetz 70008d9bfb26SMike Kravetz #ifdef CONFIG_USERFAULTFD 70018d9bfb26SMike Kravetz if (uffd_disable_huge_pmd_share(vma)) 70028d9bfb26SMike Kravetz return false; 70038d9bfb26SMike Kravetz #endif 70043212b535SSteve Capper /* 70053212b535SSteve Capper * check on proper vm_flags and page table alignment 70063212b535SSteve Capper */ 70078d9bfb26SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 700831aafb45SNicholas Krause return false; 7009bbff39ccSMike Kravetz if (!vma->vm_private_data) /* vma lock required for sharing */ 70108d9bfb26SMike Kravetz return false; 70118d9bfb26SMike Kravetz if (!range_in_vma(vma, start, end)) 70128d9bfb26SMike Kravetz return false; 70138d9bfb26SMike Kravetz return true; 70148d9bfb26SMike Kravetz } 70158d9bfb26SMike Kravetz 70163212b535SSteve Capper /* 7017017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 7018017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 7019017b1660SMike Kravetz * shared pmd mappings. 7020017b1660SMike Kravetz */ 7021017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 7022017b1660SMike Kravetz unsigned long *start, unsigned long *end) 7023017b1660SMike Kravetz { 7024a1ba9da8SLi Xinhai unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE), 7025a1ba9da8SLi Xinhai v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 7026017b1660SMike Kravetz 7027a1ba9da8SLi Xinhai /* 7028f0953a1bSIngo Molnar * vma needs to span at least one aligned PUD size, and the range 7029f0953a1bSIngo Molnar * must be at least partially within in. 7030a1ba9da8SLi Xinhai */ 7031a1ba9da8SLi Xinhai if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) || 7032a1ba9da8SLi Xinhai (*end <= v_start) || (*start >= v_end)) 7033017b1660SMike Kravetz return; 7034017b1660SMike Kravetz 703575802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 7036a1ba9da8SLi Xinhai if (*start > v_start) 7037a1ba9da8SLi Xinhai *start = ALIGN_DOWN(*start, PUD_SIZE); 7038017b1660SMike Kravetz 7039a1ba9da8SLi Xinhai if (*end < v_end) 7040a1ba9da8SLi Xinhai *end = ALIGN(*end, PUD_SIZE); 7041017b1660SMike Kravetz } 7042017b1660SMike Kravetz 7043017b1660SMike Kravetz /* 70443212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 70453212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 70463212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 70473a47c54fSMike Kravetz * code much cleaner. pmd allocation is essential for the shared case because 70483a47c54fSMike Kravetz * pud has to be populated inside the same i_mmap_rwsem section - otherwise 70493a47c54fSMike Kravetz * racing tasks could either miss the sharing (see huge_pte_offset) or select a 70503a47c54fSMike Kravetz * bad pmd for sharing. 70513212b535SSteve Capper */ 7052aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 7053aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 70543212b535SSteve Capper { 70553212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 70563212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 70573212b535SSteve Capper vma->vm_pgoff; 70583212b535SSteve Capper struct vm_area_struct *svma; 70593212b535SSteve Capper unsigned long saddr; 70603212b535SSteve Capper pte_t *spte = NULL; 70613212b535SSteve Capper pte_t *pte; 7062cb900f41SKirill A. Shutemov spinlock_t *ptl; 70633212b535SSteve Capper 70643a47c54fSMike Kravetz i_mmap_lock_read(mapping); 70653212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 70663212b535SSteve Capper if (svma == vma) 70673212b535SSteve Capper continue; 70683212b535SSteve Capper 70693212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 70703212b535SSteve Capper if (saddr) { 70717868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 70727868a208SPunit Agrawal vma_mmu_pagesize(svma)); 70733212b535SSteve Capper if (spte) { 70743212b535SSteve Capper get_page(virt_to_page(spte)); 70753212b535SSteve Capper break; 70763212b535SSteve Capper } 70773212b535SSteve Capper } 70783212b535SSteve Capper } 70793212b535SSteve Capper 70803212b535SSteve Capper if (!spte) 70813212b535SSteve Capper goto out; 70823212b535SSteve Capper 70838bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 7084dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 70853212b535SSteve Capper pud_populate(mm, pud, 70863212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 7087c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 7088dc6c9a35SKirill A. Shutemov } else { 70893212b535SSteve Capper put_page(virt_to_page(spte)); 7090dc6c9a35SKirill A. Shutemov } 7091cb900f41SKirill A. Shutemov spin_unlock(ptl); 70923212b535SSteve Capper out: 70933212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 70943a47c54fSMike Kravetz i_mmap_unlock_read(mapping); 70953212b535SSteve Capper return pte; 70963212b535SSteve Capper } 70973212b535SSteve Capper 70983212b535SSteve Capper /* 70993212b535SSteve Capper * unmap huge page backed by shared pte. 71003212b535SSteve Capper * 71013212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 71023212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 71033212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 71043212b535SSteve Capper * 71053a47c54fSMike Kravetz * Called with page table lock held. 71063212b535SSteve Capper * 71073212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 71083212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 71093212b535SSteve Capper */ 711034ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 71114ddb4d91SMike Kravetz unsigned long addr, pte_t *ptep) 71123212b535SSteve Capper { 71134ddb4d91SMike Kravetz pgd_t *pgd = pgd_offset(mm, addr); 71144ddb4d91SMike Kravetz p4d_t *p4d = p4d_offset(pgd, addr); 71154ddb4d91SMike Kravetz pud_t *pud = pud_offset(p4d, addr); 71163212b535SSteve Capper 711734ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 711840549ba8SMike Kravetz hugetlb_vma_assert_locked(vma); 71193212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 71203212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 71213212b535SSteve Capper return 0; 71223212b535SSteve Capper 71233212b535SSteve Capper pud_clear(pud); 71243212b535SSteve Capper put_page(virt_to_page(ptep)); 7125dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 71263212b535SSteve Capper return 1; 71273212b535SSteve Capper } 7128c1991e07SPeter Xu 71299e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 71308d9bfb26SMike Kravetz 7131aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 7132aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 71339e5fc74cSSteve Capper { 71349e5fc74cSSteve Capper return NULL; 71359e5fc74cSSteve Capper } 7136e81f2d22SZhang Zhen 713734ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 71384ddb4d91SMike Kravetz unsigned long addr, pte_t *ptep) 7139e81f2d22SZhang Zhen { 7140e81f2d22SZhang Zhen return 0; 7141e81f2d22SZhang Zhen } 7142017b1660SMike Kravetz 7143017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 7144017b1660SMike Kravetz unsigned long *start, unsigned long *end) 7145017b1660SMike Kravetz { 7146017b1660SMike Kravetz } 7147c1991e07SPeter Xu 7148c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 7149c1991e07SPeter Xu { 7150c1991e07SPeter Xu return false; 7151c1991e07SPeter Xu } 71523212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 71533212b535SSteve Capper 71549e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 7155aec44e0fSPeter Xu pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 71569e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 71579e5fc74cSSteve Capper { 71589e5fc74cSSteve Capper pgd_t *pgd; 7159c2febafcSKirill A. Shutemov p4d_t *p4d; 71609e5fc74cSSteve Capper pud_t *pud; 71619e5fc74cSSteve Capper pte_t *pte = NULL; 71629e5fc74cSSteve Capper 71639e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 7164f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 7165f4f0a3d8SKirill A. Shutemov if (!p4d) 7166f4f0a3d8SKirill A. Shutemov return NULL; 7167c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 71689e5fc74cSSteve Capper if (pud) { 71699e5fc74cSSteve Capper if (sz == PUD_SIZE) { 71709e5fc74cSSteve Capper pte = (pte_t *)pud; 71719e5fc74cSSteve Capper } else { 71729e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 7173c1991e07SPeter Xu if (want_pmd_share(vma, addr) && pud_none(*pud)) 7174aec44e0fSPeter Xu pte = huge_pmd_share(mm, vma, addr, pud); 71759e5fc74cSSteve Capper else 71769e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 71779e5fc74cSSteve Capper } 71789e5fc74cSSteve Capper } 71794e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 71809e5fc74cSSteve Capper 71819e5fc74cSSteve Capper return pte; 71829e5fc74cSSteve Capper } 71839e5fc74cSSteve Capper 71849b19df29SPunit Agrawal /* 71859b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 71869b19df29SPunit Agrawal * entry at address @addr 71879b19df29SPunit Agrawal * 71888ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 71898ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 71909b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 71919b19df29SPunit Agrawal * table. 71929b19df29SPunit Agrawal */ 71937868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 71947868a208SPunit Agrawal unsigned long addr, unsigned long sz) 71959e5fc74cSSteve Capper { 71969e5fc74cSSteve Capper pgd_t *pgd; 7197c2febafcSKirill A. Shutemov p4d_t *p4d; 71988ac0b81aSLi Xinhai pud_t *pud; 71998ac0b81aSLi Xinhai pmd_t *pmd; 72009e5fc74cSSteve Capper 72019e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 7202c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 7203c2febafcSKirill A. Shutemov return NULL; 7204c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 7205c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 7206c2febafcSKirill A. Shutemov return NULL; 72079b19df29SPunit Agrawal 7208c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 72098ac0b81aSLi Xinhai if (sz == PUD_SIZE) 72108ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 72119e5fc74cSSteve Capper return (pte_t *)pud; 72128ac0b81aSLi Xinhai if (!pud_present(*pud)) 72138ac0b81aSLi Xinhai return NULL; 72148ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 72159b19df29SPunit Agrawal 72169e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 72178ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 72189e5fc74cSSteve Capper return (pte_t *)pmd; 72199e5fc74cSSteve Capper } 72209e5fc74cSSteve Capper 7221e95a9851SMike Kravetz /* 7222e95a9851SMike Kravetz * Return a mask that can be used to update an address to the last huge 7223e95a9851SMike Kravetz * page in a page table page mapping size. Used to skip non-present 7224e95a9851SMike Kravetz * page table entries when linearly scanning address ranges. Architectures 7225e95a9851SMike Kravetz * with unique huge page to page table relationships can define their own 7226e95a9851SMike Kravetz * version of this routine. 7227e95a9851SMike Kravetz */ 7228e95a9851SMike Kravetz unsigned long hugetlb_mask_last_page(struct hstate *h) 7229e95a9851SMike Kravetz { 7230e95a9851SMike Kravetz unsigned long hp_size = huge_page_size(h); 7231e95a9851SMike Kravetz 7232e95a9851SMike Kravetz if (hp_size == PUD_SIZE) 7233e95a9851SMike Kravetz return P4D_SIZE - PUD_SIZE; 7234e95a9851SMike Kravetz else if (hp_size == PMD_SIZE) 7235e95a9851SMike Kravetz return PUD_SIZE - PMD_SIZE; 7236e95a9851SMike Kravetz else 7237e95a9851SMike Kravetz return 0UL; 7238e95a9851SMike Kravetz } 7239e95a9851SMike Kravetz 7240e95a9851SMike Kravetz #else 7241e95a9851SMike Kravetz 7242e95a9851SMike Kravetz /* See description above. Architectures can provide their own version. */ 7243e95a9851SMike Kravetz __weak unsigned long hugetlb_mask_last_page(struct hstate *h) 7244e95a9851SMike Kravetz { 72454ddb4d91SMike Kravetz #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 72464ddb4d91SMike Kravetz if (huge_page_size(h) == PMD_SIZE) 72474ddb4d91SMike Kravetz return PUD_SIZE - PMD_SIZE; 72484ddb4d91SMike Kravetz #endif 7249e95a9851SMike Kravetz return 0UL; 7250e95a9851SMike Kravetz } 7251e95a9851SMike Kravetz 725261f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 725361f77edaSNaoya Horiguchi 725461f77edaSNaoya Horiguchi /* 725561f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 725661f77edaSNaoya Horiguchi * behavior. 725761f77edaSNaoya Horiguchi */ 72587ce82f4cSMiaohe Lin int isolate_hugetlb(struct page *page, struct list_head *list) 725931caf665SNaoya Horiguchi { 72607ce82f4cSMiaohe Lin int ret = 0; 7261bcc54222SNaoya Horiguchi 7262db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 72638f251a3dSMike Kravetz if (!PageHeadHuge(page) || 72648f251a3dSMike Kravetz !HPageMigratable(page) || 72650eb2df2bSMuchun Song !get_page_unless_zero(page)) { 72667ce82f4cSMiaohe Lin ret = -EBUSY; 7267bcc54222SNaoya Horiguchi goto unlock; 7268bcc54222SNaoya Horiguchi } 72698f251a3dSMike Kravetz ClearHPageMigratable(page); 727031caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 7271bcc54222SNaoya Horiguchi unlock: 7272db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7273bcc54222SNaoya Horiguchi return ret; 727431caf665SNaoya Horiguchi } 727531caf665SNaoya Horiguchi 7276e591ef7dSNaoya Horiguchi int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison) 727725182f05SNaoya Horiguchi { 727825182f05SNaoya Horiguchi int ret = 0; 727925182f05SNaoya Horiguchi 728025182f05SNaoya Horiguchi *hugetlb = false; 728125182f05SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 728225182f05SNaoya Horiguchi if (PageHeadHuge(page)) { 728325182f05SNaoya Horiguchi *hugetlb = true; 7284b283d983SNaoya Horiguchi if (HPageFreed(page)) 7285b283d983SNaoya Horiguchi ret = 0; 7286e591ef7dSNaoya Horiguchi else if (HPageMigratable(page) || unpoison) 728725182f05SNaoya Horiguchi ret = get_page_unless_zero(page); 72880ed950d1SNaoya Horiguchi else 72890ed950d1SNaoya Horiguchi ret = -EBUSY; 729025182f05SNaoya Horiguchi } 729125182f05SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 729225182f05SNaoya Horiguchi return ret; 729325182f05SNaoya Horiguchi } 729425182f05SNaoya Horiguchi 7295e591ef7dSNaoya Horiguchi int get_huge_page_for_hwpoison(unsigned long pfn, int flags, 7296e591ef7dSNaoya Horiguchi bool *migratable_cleared) 7297405ce051SNaoya Horiguchi { 7298405ce051SNaoya Horiguchi int ret; 7299405ce051SNaoya Horiguchi 7300405ce051SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 7301e591ef7dSNaoya Horiguchi ret = __get_huge_page_for_hwpoison(pfn, flags, migratable_cleared); 7302405ce051SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 7303405ce051SNaoya Horiguchi return ret; 7304405ce051SNaoya Horiguchi } 7305405ce051SNaoya Horiguchi 730631caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 730731caf665SNaoya Horiguchi { 7308db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 73098f251a3dSMike Kravetz SetHPageMigratable(page); 731031caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 7311db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 731231caf665SNaoya Horiguchi put_page(page); 731331caf665SNaoya Horiguchi } 7314ab5ac90aSMichal Hocko 7315345c62d1SSidhartha Kumar void move_hugetlb_state(struct folio *old_folio, struct folio *new_folio, int reason) 7316ab5ac90aSMichal Hocko { 7317345c62d1SSidhartha Kumar struct hstate *h = folio_hstate(old_folio); 7318ab5ac90aSMichal Hocko 7319345c62d1SSidhartha Kumar hugetlb_cgroup_migrate(old_folio, new_folio); 7320345c62d1SSidhartha Kumar set_page_owner_migrate_reason(&new_folio->page, reason); 7321ab5ac90aSMichal Hocko 7322ab5ac90aSMichal Hocko /* 7323345c62d1SSidhartha Kumar * transfer temporary state of the new hugetlb folio. This is 7324ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 7325ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 7326ab5ac90aSMichal Hocko * the temporary status. 7327ab5ac90aSMichal Hocko * 7328ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 7329ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 7330ab5ac90aSMichal Hocko * the per-node's. 7331ab5ac90aSMichal Hocko */ 7332345c62d1SSidhartha Kumar if (folio_test_hugetlb_temporary(new_folio)) { 7333345c62d1SSidhartha Kumar int old_nid = folio_nid(old_folio); 7334345c62d1SSidhartha Kumar int new_nid = folio_nid(new_folio); 7335ab5ac90aSMichal Hocko 7336345c62d1SSidhartha Kumar folio_set_hugetlb_temporary(old_folio); 7337345c62d1SSidhartha Kumar folio_clear_hugetlb_temporary(new_folio); 7338345c62d1SSidhartha Kumar 7339ab5ac90aSMichal Hocko 73405af1ab1dSMiaohe Lin /* 73415af1ab1dSMiaohe Lin * There is no need to transfer the per-node surplus state 73425af1ab1dSMiaohe Lin * when we do not cross the node. 73435af1ab1dSMiaohe Lin */ 73445af1ab1dSMiaohe Lin if (new_nid == old_nid) 73455af1ab1dSMiaohe Lin return; 7346db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 7347ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 7348ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 7349ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 7350ab5ac90aSMichal Hocko } 7351db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7352ab5ac90aSMichal Hocko } 7353ab5ac90aSMichal Hocko } 7354cf11e85fSRoman Gushchin 7355b30c14cdSJames Houghton static void hugetlb_unshare_pmds(struct vm_area_struct *vma, 7356b30c14cdSJames Houghton unsigned long start, 7357b30c14cdSJames Houghton unsigned long end) 73586dfeaff9SPeter Xu { 73596dfeaff9SPeter Xu struct hstate *h = hstate_vma(vma); 73606dfeaff9SPeter Xu unsigned long sz = huge_page_size(h); 73616dfeaff9SPeter Xu struct mm_struct *mm = vma->vm_mm; 73626dfeaff9SPeter Xu struct mmu_notifier_range range; 7363b30c14cdSJames Houghton unsigned long address; 73646dfeaff9SPeter Xu spinlock_t *ptl; 73656dfeaff9SPeter Xu pte_t *ptep; 73666dfeaff9SPeter Xu 73676dfeaff9SPeter Xu if (!(vma->vm_flags & VM_MAYSHARE)) 73686dfeaff9SPeter Xu return; 73696dfeaff9SPeter Xu 73706dfeaff9SPeter Xu if (start >= end) 73716dfeaff9SPeter Xu return; 73726dfeaff9SPeter Xu 73739c8bbfacSBaolin Wang flush_cache_range(vma, start, end); 73746dfeaff9SPeter Xu /* 73756dfeaff9SPeter Xu * No need to call adjust_range_if_pmd_sharing_possible(), because 73766dfeaff9SPeter Xu * we have already done the PUD_SIZE alignment. 73776dfeaff9SPeter Xu */ 73786dfeaff9SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 73796dfeaff9SPeter Xu start, end); 73806dfeaff9SPeter Xu mmu_notifier_invalidate_range_start(&range); 738140549ba8SMike Kravetz hugetlb_vma_lock_write(vma); 73826dfeaff9SPeter Xu i_mmap_lock_write(vma->vm_file->f_mapping); 73836dfeaff9SPeter Xu for (address = start; address < end; address += PUD_SIZE) { 73846dfeaff9SPeter Xu ptep = huge_pte_offset(mm, address, sz); 73856dfeaff9SPeter Xu if (!ptep) 73866dfeaff9SPeter Xu continue; 73876dfeaff9SPeter Xu ptl = huge_pte_lock(h, mm, ptep); 73884ddb4d91SMike Kravetz huge_pmd_unshare(mm, vma, address, ptep); 73896dfeaff9SPeter Xu spin_unlock(ptl); 73906dfeaff9SPeter Xu } 73916dfeaff9SPeter Xu flush_hugetlb_tlb_range(vma, start, end); 73926dfeaff9SPeter Xu i_mmap_unlock_write(vma->vm_file->f_mapping); 739340549ba8SMike Kravetz hugetlb_vma_unlock_write(vma); 73946dfeaff9SPeter Xu /* 73956dfeaff9SPeter Xu * No need to call mmu_notifier_invalidate_range(), see 7396ee65728eSMike Rapoport * Documentation/mm/mmu_notifier.rst. 73976dfeaff9SPeter Xu */ 73986dfeaff9SPeter Xu mmu_notifier_invalidate_range_end(&range); 73996dfeaff9SPeter Xu } 74006dfeaff9SPeter Xu 7401b30c14cdSJames Houghton /* 7402b30c14cdSJames Houghton * This function will unconditionally remove all the shared pmd pgtable entries 7403b30c14cdSJames Houghton * within the specific vma for a hugetlbfs memory range. 7404b30c14cdSJames Houghton */ 7405b30c14cdSJames Houghton void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) 7406b30c14cdSJames Houghton { 7407b30c14cdSJames Houghton hugetlb_unshare_pmds(vma, ALIGN(vma->vm_start, PUD_SIZE), 7408b30c14cdSJames Houghton ALIGN_DOWN(vma->vm_end, PUD_SIZE)); 7409b30c14cdSJames Houghton } 7410b30c14cdSJames Houghton 7411cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 7412cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 7413cf11e85fSRoman Gushchin 7414cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 7415cf11e85fSRoman Gushchin { 741638e719abSBaolin Wang int nid, count = 0; 741738e719abSBaolin Wang unsigned long tmp; 741838e719abSBaolin Wang char *s = p; 741938e719abSBaolin Wang 742038e719abSBaolin Wang while (*s) { 742138e719abSBaolin Wang if (sscanf(s, "%lu%n", &tmp, &count) != 1) 742238e719abSBaolin Wang break; 742338e719abSBaolin Wang 742438e719abSBaolin Wang if (s[count] == ':') { 7425f9317f77SMike Kravetz if (tmp >= MAX_NUMNODES) 742638e719abSBaolin Wang break; 7427f9317f77SMike Kravetz nid = array_index_nospec(tmp, MAX_NUMNODES); 742838e719abSBaolin Wang 742938e719abSBaolin Wang s += count + 1; 743038e719abSBaolin Wang tmp = memparse(s, &s); 743138e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = tmp; 743238e719abSBaolin Wang hugetlb_cma_size += tmp; 743338e719abSBaolin Wang 743438e719abSBaolin Wang /* 743538e719abSBaolin Wang * Skip the separator if have one, otherwise 743638e719abSBaolin Wang * break the parsing. 743738e719abSBaolin Wang */ 743838e719abSBaolin Wang if (*s == ',') 743938e719abSBaolin Wang s++; 744038e719abSBaolin Wang else 744138e719abSBaolin Wang break; 744238e719abSBaolin Wang } else { 7443cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 744438e719abSBaolin Wang break; 744538e719abSBaolin Wang } 744638e719abSBaolin Wang } 744738e719abSBaolin Wang 7448cf11e85fSRoman Gushchin return 0; 7449cf11e85fSRoman Gushchin } 7450cf11e85fSRoman Gushchin 7451cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 7452cf11e85fSRoman Gushchin 7453cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 7454cf11e85fSRoman Gushchin { 7455cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 745638e719abSBaolin Wang bool node_specific_cma_alloc = false; 7457cf11e85fSRoman Gushchin int nid; 7458cf11e85fSRoman Gushchin 7459cf11e85fSRoman Gushchin cma_reserve_called = true; 7460cf11e85fSRoman Gushchin 7461cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 7462cf11e85fSRoman Gushchin return; 7463cf11e85fSRoman Gushchin 746438e719abSBaolin Wang for (nid = 0; nid < MAX_NUMNODES; nid++) { 746538e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 746638e719abSBaolin Wang continue; 746738e719abSBaolin Wang 746830a51400SPeng Liu if (!node_online(nid)) { 746938e719abSBaolin Wang pr_warn("hugetlb_cma: invalid node %d specified\n", nid); 747038e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 747138e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 747238e719abSBaolin Wang continue; 747338e719abSBaolin Wang } 747438e719abSBaolin Wang 747538e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] < (PAGE_SIZE << order)) { 747638e719abSBaolin Wang pr_warn("hugetlb_cma: cma area of node %d should be at least %lu MiB\n", 747738e719abSBaolin Wang nid, (PAGE_SIZE << order) / SZ_1M); 747838e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 747938e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 748038e719abSBaolin Wang } else { 748138e719abSBaolin Wang node_specific_cma_alloc = true; 748238e719abSBaolin Wang } 748338e719abSBaolin Wang } 748438e719abSBaolin Wang 748538e719abSBaolin Wang /* Validate the CMA size again in case some invalid nodes specified. */ 748638e719abSBaolin Wang if (!hugetlb_cma_size) 748738e719abSBaolin Wang return; 748838e719abSBaolin Wang 7489cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 7490cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 7491cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 7492a01f4390SMike Kravetz hugetlb_cma_size = 0; 7493cf11e85fSRoman Gushchin return; 7494cf11e85fSRoman Gushchin } 7495cf11e85fSRoman Gushchin 749638e719abSBaolin Wang if (!node_specific_cma_alloc) { 7497cf11e85fSRoman Gushchin /* 7498cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 7499cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 7500cf11e85fSRoman Gushchin */ 7501cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 7502cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 7503cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 750438e719abSBaolin Wang } 7505cf11e85fSRoman Gushchin 7506cf11e85fSRoman Gushchin reserved = 0; 750730a51400SPeng Liu for_each_online_node(nid) { 7508cf11e85fSRoman Gushchin int res; 75092281f797SBarry Song char name[CMA_MAX_NAME]; 7510cf11e85fSRoman Gushchin 751138e719abSBaolin Wang if (node_specific_cma_alloc) { 751238e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 751338e719abSBaolin Wang continue; 751438e719abSBaolin Wang 751538e719abSBaolin Wang size = hugetlb_cma_size_in_node[nid]; 751638e719abSBaolin Wang } else { 7517cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 751838e719abSBaolin Wang } 751938e719abSBaolin Wang 7520cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 7521cf11e85fSRoman Gushchin 75222281f797SBarry Song snprintf(name, sizeof(name), "hugetlb%d", nid); 7523a01f4390SMike Kravetz /* 7524a01f4390SMike Kravetz * Note that 'order per bit' is based on smallest size that 7525a01f4390SMike Kravetz * may be returned to CMA allocator in the case of 7526a01f4390SMike Kravetz * huge page demotion. 7527a01f4390SMike Kravetz */ 7528a01f4390SMike Kravetz res = cma_declare_contiguous_nid(0, size, 0, 7529a01f4390SMike Kravetz PAGE_SIZE << HUGETLB_PAGE_ORDER, 753029d0f41dSBarry Song 0, false, name, 7531cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 7532cf11e85fSRoman Gushchin if (res) { 7533cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 7534cf11e85fSRoman Gushchin res, nid); 7535cf11e85fSRoman Gushchin continue; 7536cf11e85fSRoman Gushchin } 7537cf11e85fSRoman Gushchin 7538cf11e85fSRoman Gushchin reserved += size; 7539cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 7540cf11e85fSRoman Gushchin size / SZ_1M, nid); 7541cf11e85fSRoman Gushchin 7542cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 7543cf11e85fSRoman Gushchin break; 7544cf11e85fSRoman Gushchin } 7545a01f4390SMike Kravetz 7546a01f4390SMike Kravetz if (!reserved) 7547a01f4390SMike Kravetz /* 7548a01f4390SMike Kravetz * hugetlb_cma_size is used to determine if allocations from 7549a01f4390SMike Kravetz * cma are possible. Set to zero if no cma regions are set up. 7550a01f4390SMike Kravetz */ 7551a01f4390SMike Kravetz hugetlb_cma_size = 0; 7552cf11e85fSRoman Gushchin } 7553cf11e85fSRoman Gushchin 7554263b8998SMiaohe Lin static void __init hugetlb_cma_check(void) 7555cf11e85fSRoman Gushchin { 7556cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 7557cf11e85fSRoman Gushchin return; 7558cf11e85fSRoman Gushchin 7559cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 7560cf11e85fSRoman Gushchin } 7561cf11e85fSRoman Gushchin 7562cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 7563