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; 57a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 58a01f4390SMike Kravetz { 59a01f4390SMike Kravetz return cma_pages_valid(hugetlb_cma[page_to_nid(page)], page, 60a01f4390SMike Kravetz 1 << order); 61a01f4390SMike Kravetz } 62a01f4390SMike Kravetz #else 63a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, 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); 967ca02d0aSMike Kravetz 971d88433bSMiaohe Lin static inline bool subpool_is_free(struct hugepage_subpool *spool) 981d88433bSMiaohe Lin { 991d88433bSMiaohe Lin if (spool->count) 1001d88433bSMiaohe Lin return false; 1011d88433bSMiaohe Lin if (spool->max_hpages != -1) 1021d88433bSMiaohe Lin return spool->used_hpages == 0; 1031d88433bSMiaohe Lin if (spool->min_hpages != -1) 1041d88433bSMiaohe Lin return spool->rsv_hpages == spool->min_hpages; 1051d88433bSMiaohe Lin 1061d88433bSMiaohe Lin return true; 1071d88433bSMiaohe Lin } 1081d88433bSMiaohe Lin 109db71ef79SMike Kravetz static inline void unlock_or_release_subpool(struct hugepage_subpool *spool, 110db71ef79SMike Kravetz unsigned long irq_flags) 11190481622SDavid Gibson { 112db71ef79SMike Kravetz spin_unlock_irqrestore(&spool->lock, irq_flags); 11390481622SDavid Gibson 11490481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 1157c8de358SEthon Paul * remain, give up any reservations based on minimum size and 1167ca02d0aSMike Kravetz * free the subpool */ 1171d88433bSMiaohe Lin if (subpool_is_free(spool)) { 1187ca02d0aSMike Kravetz if (spool->min_hpages != -1) 1197ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 1207ca02d0aSMike Kravetz -spool->min_hpages); 12190481622SDavid Gibson kfree(spool); 12290481622SDavid Gibson } 1237ca02d0aSMike Kravetz } 12490481622SDavid Gibson 1257ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1267ca02d0aSMike Kravetz long min_hpages) 12790481622SDavid Gibson { 12890481622SDavid Gibson struct hugepage_subpool *spool; 12990481622SDavid Gibson 130c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 13190481622SDavid Gibson if (!spool) 13290481622SDavid Gibson return NULL; 13390481622SDavid Gibson 13490481622SDavid Gibson spin_lock_init(&spool->lock); 13590481622SDavid Gibson spool->count = 1; 1367ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1377ca02d0aSMike Kravetz spool->hstate = h; 1387ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1397ca02d0aSMike Kravetz 1407ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1417ca02d0aSMike Kravetz kfree(spool); 1427ca02d0aSMike Kravetz return NULL; 1437ca02d0aSMike Kravetz } 1447ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 14590481622SDavid Gibson 14690481622SDavid Gibson return spool; 14790481622SDavid Gibson } 14890481622SDavid Gibson 14990481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 15090481622SDavid Gibson { 151db71ef79SMike Kravetz unsigned long flags; 152db71ef79SMike Kravetz 153db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 15490481622SDavid Gibson BUG_ON(!spool->count); 15590481622SDavid Gibson spool->count--; 156db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 15790481622SDavid Gibson } 15890481622SDavid Gibson 1591c5ecae3SMike Kravetz /* 1601c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1611c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1629e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1631c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1641c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1657c8de358SEthon Paul * a subpool minimum size must be maintained. 1661c5ecae3SMike Kravetz */ 1671c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 16890481622SDavid Gibson long delta) 16990481622SDavid Gibson { 1701c5ecae3SMike Kravetz long ret = delta; 17190481622SDavid Gibson 17290481622SDavid Gibson if (!spool) 1731c5ecae3SMike Kravetz return ret; 17490481622SDavid Gibson 175db71ef79SMike Kravetz spin_lock_irq(&spool->lock); 17690481622SDavid Gibson 1771c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1781c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1791c5ecae3SMike Kravetz spool->used_hpages += delta; 1801c5ecae3SMike Kravetz else { 1811c5ecae3SMike Kravetz ret = -ENOMEM; 1821c5ecae3SMike Kravetz goto unlock_ret; 1831c5ecae3SMike Kravetz } 1841c5ecae3SMike Kravetz } 1851c5ecae3SMike Kravetz 18609a95e29SMike Kravetz /* minimum size accounting */ 18709a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1881c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1891c5ecae3SMike Kravetz /* 1901c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1911c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1921c5ecae3SMike Kravetz */ 1931c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1941c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1951c5ecae3SMike Kravetz } else { 1961c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1971c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 1981c5ecae3SMike Kravetz } 1991c5ecae3SMike Kravetz } 2001c5ecae3SMike Kravetz 2011c5ecae3SMike Kravetz unlock_ret: 202db71ef79SMike Kravetz spin_unlock_irq(&spool->lock); 20390481622SDavid Gibson return ret; 20490481622SDavid Gibson } 20590481622SDavid Gibson 2061c5ecae3SMike Kravetz /* 2071c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 2081c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 2091c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 2101c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 2111c5ecae3SMike Kravetz */ 2121c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 21390481622SDavid Gibson long delta) 21490481622SDavid Gibson { 2151c5ecae3SMike Kravetz long ret = delta; 216db71ef79SMike Kravetz unsigned long flags; 2171c5ecae3SMike Kravetz 21890481622SDavid Gibson if (!spool) 2191c5ecae3SMike Kravetz return delta; 22090481622SDavid Gibson 221db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 2221c5ecae3SMike Kravetz 2231c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 22490481622SDavid Gibson spool->used_hpages -= delta; 2251c5ecae3SMike Kravetz 22609a95e29SMike Kravetz /* minimum size accounting */ 22709a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2281c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2291c5ecae3SMike Kravetz ret = 0; 2301c5ecae3SMike Kravetz else 2311c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2321c5ecae3SMike Kravetz 2331c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2341c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2351c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2361c5ecae3SMike Kravetz } 2371c5ecae3SMike Kravetz 2381c5ecae3SMike Kravetz /* 2391c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2401c5ecae3SMike Kravetz * quota reference, free it now. 2411c5ecae3SMike Kravetz */ 242db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 2431c5ecae3SMike Kravetz 2441c5ecae3SMike Kravetz return ret; 24590481622SDavid Gibson } 24690481622SDavid Gibson 24790481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 24890481622SDavid Gibson { 24990481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 25090481622SDavid Gibson } 25190481622SDavid Gibson 25290481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 25390481622SDavid Gibson { 254496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 25590481622SDavid Gibson } 25690481622SDavid Gibson 2570db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2580db9d74eSMina Almasry * it for use. 2590db9d74eSMina Almasry */ 2600db9d74eSMina Almasry static struct file_region * 2610db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2620db9d74eSMina Almasry { 2633259914fSXU pengfei struct file_region *nrg; 2640db9d74eSMina Almasry 2650db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2660db9d74eSMina Almasry 2670db9d74eSMina Almasry resv->region_cache_count--; 2680db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2690db9d74eSMina Almasry list_del(&nrg->link); 2700db9d74eSMina Almasry 2710db9d74eSMina Almasry nrg->from = from; 2720db9d74eSMina Almasry nrg->to = to; 2730db9d74eSMina Almasry 2740db9d74eSMina Almasry return nrg; 2750db9d74eSMina Almasry } 2760db9d74eSMina Almasry 277075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 278075a61d0SMina Almasry struct file_region *rg) 279075a61d0SMina Almasry { 280075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 281075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 282075a61d0SMina Almasry nrg->css = rg->css; 283075a61d0SMina Almasry if (rg->css) 284075a61d0SMina Almasry css_get(rg->css); 285075a61d0SMina Almasry #endif 286075a61d0SMina Almasry } 287075a61d0SMina Almasry 288075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 289075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 290075a61d0SMina Almasry struct hstate *h, 291075a61d0SMina Almasry struct resv_map *resv, 292075a61d0SMina Almasry struct file_region *nrg) 293075a61d0SMina Almasry { 294075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 295075a61d0SMina Almasry if (h_cg) { 296075a61d0SMina Almasry nrg->reservation_counter = 297075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 298075a61d0SMina Almasry nrg->css = &h_cg->css; 299d85aecf2SMiaohe Lin /* 300d85aecf2SMiaohe Lin * The caller will hold exactly one h_cg->css reference for the 301d85aecf2SMiaohe Lin * whole contiguous reservation region. But this area might be 302d85aecf2SMiaohe Lin * scattered when there are already some file_regions reside in 303d85aecf2SMiaohe Lin * it. As a result, many file_regions may share only one css 304d85aecf2SMiaohe Lin * reference. In order to ensure that one file_region must hold 305d85aecf2SMiaohe Lin * exactly one h_cg->css reference, we should do css_get for 306d85aecf2SMiaohe Lin * each file_region and leave the reference held by caller 307d85aecf2SMiaohe Lin * untouched. 308d85aecf2SMiaohe Lin */ 309d85aecf2SMiaohe Lin css_get(&h_cg->css); 310075a61d0SMina Almasry if (!resv->pages_per_hpage) 311075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 312075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 313075a61d0SMina Almasry * a resv_map. 314075a61d0SMina Almasry */ 315075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 316075a61d0SMina Almasry } else { 317075a61d0SMina Almasry nrg->reservation_counter = NULL; 318075a61d0SMina Almasry nrg->css = NULL; 319075a61d0SMina Almasry } 320075a61d0SMina Almasry #endif 321075a61d0SMina Almasry } 322075a61d0SMina Almasry 323d85aecf2SMiaohe Lin static void put_uncharge_info(struct file_region *rg) 324d85aecf2SMiaohe Lin { 325d85aecf2SMiaohe Lin #ifdef CONFIG_CGROUP_HUGETLB 326d85aecf2SMiaohe Lin if (rg->css) 327d85aecf2SMiaohe Lin css_put(rg->css); 328d85aecf2SMiaohe Lin #endif 329d85aecf2SMiaohe Lin } 330d85aecf2SMiaohe Lin 331a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 332a9b3f867SMina Almasry struct file_region *org) 333a9b3f867SMina Almasry { 334a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 3350739eb43SBaolin Wang return rg->reservation_counter == org->reservation_counter && 336a9b3f867SMina Almasry rg->css == org->css; 337a9b3f867SMina Almasry 338a9b3f867SMina Almasry #else 339a9b3f867SMina Almasry return true; 340a9b3f867SMina Almasry #endif 341a9b3f867SMina Almasry } 342a9b3f867SMina Almasry 343a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 344a9b3f867SMina Almasry { 3453259914fSXU pengfei struct file_region *nrg, *prg; 346a9b3f867SMina Almasry 347a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 348a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 349a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 350a9b3f867SMina Almasry prg->to = rg->to; 351a9b3f867SMina Almasry 352a9b3f867SMina Almasry list_del(&rg->link); 353d85aecf2SMiaohe Lin put_uncharge_info(rg); 354a9b3f867SMina Almasry kfree(rg); 355a9b3f867SMina Almasry 3567db5e7b6SWei Yang rg = prg; 357a9b3f867SMina Almasry } 358a9b3f867SMina Almasry 359a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 360a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 361a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 362a9b3f867SMina Almasry nrg->from = rg->from; 363a9b3f867SMina Almasry 364a9b3f867SMina Almasry list_del(&rg->link); 365d85aecf2SMiaohe Lin put_uncharge_info(rg); 366a9b3f867SMina Almasry kfree(rg); 367a9b3f867SMina Almasry } 368a9b3f867SMina Almasry } 369a9b3f867SMina Almasry 3702103cf9cSPeter Xu static inline long 37184448c8eSJakob Koschel hugetlb_resv_map_add(struct resv_map *map, struct list_head *rg, long from, 3722103cf9cSPeter Xu long to, struct hstate *h, struct hugetlb_cgroup *cg, 3732103cf9cSPeter Xu long *regions_needed) 3742103cf9cSPeter Xu { 3752103cf9cSPeter Xu struct file_region *nrg; 3762103cf9cSPeter Xu 3772103cf9cSPeter Xu if (!regions_needed) { 3782103cf9cSPeter Xu nrg = get_file_region_entry_from_cache(map, from, to); 3792103cf9cSPeter Xu record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); 38084448c8eSJakob Koschel list_add(&nrg->link, rg); 3812103cf9cSPeter Xu coalesce_file_region(map, nrg); 3822103cf9cSPeter Xu } else 3832103cf9cSPeter Xu *regions_needed += 1; 3842103cf9cSPeter Xu 3852103cf9cSPeter Xu return to - from; 3862103cf9cSPeter Xu } 3872103cf9cSPeter Xu 388972a3da3SWei Yang /* 389972a3da3SWei Yang * Must be called with resv->lock held. 390972a3da3SWei Yang * 391972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 392972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 393972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 394972a3da3SWei Yang * the regions for this range. 395d75c6af9SMina Almasry */ 396d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 397075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 398972a3da3SWei Yang struct hstate *h, long *regions_needed) 399d75c6af9SMina Almasry { 4000db9d74eSMina Almasry long add = 0; 401d75c6af9SMina Almasry struct list_head *head = &resv->regions; 4020db9d74eSMina Almasry long last_accounted_offset = f; 40384448c8eSJakob Koschel struct file_region *iter, *trg = NULL; 40484448c8eSJakob Koschel struct list_head *rg = NULL; 405d75c6af9SMina Almasry 4060db9d74eSMina Almasry if (regions_needed) 4070db9d74eSMina Almasry *regions_needed = 0; 408d75c6af9SMina Almasry 4090db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 41084448c8eSJakob Koschel * [last_accounted_offset, iter->from), at every iteration, with some 4110db9d74eSMina Almasry * bounds checking. 4120db9d74eSMina Almasry */ 41384448c8eSJakob Koschel list_for_each_entry_safe(iter, trg, head, link) { 4140db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 41584448c8eSJakob Koschel if (iter->from < f) { 4160db9d74eSMina Almasry /* If this region ends after the last accounted offset, 4170db9d74eSMina Almasry * then we need to update last_accounted_offset. 4180db9d74eSMina Almasry */ 41984448c8eSJakob Koschel if (iter->to > last_accounted_offset) 42084448c8eSJakob Koschel last_accounted_offset = iter->to; 4210db9d74eSMina Almasry continue; 4220db9d74eSMina Almasry } 423d75c6af9SMina Almasry 4240db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 4250db9d74eSMina Almasry * finished. 4260db9d74eSMina Almasry */ 42784448c8eSJakob Koschel if (iter->from >= t) { 42884448c8eSJakob Koschel rg = iter->link.prev; 429d75c6af9SMina Almasry break; 43084448c8eSJakob Koschel } 431d75c6af9SMina Almasry 43284448c8eSJakob Koschel /* Add an entry for last_accounted_offset -> iter->from, and 4330db9d74eSMina Almasry * update last_accounted_offset. 434d75c6af9SMina Almasry */ 43584448c8eSJakob Koschel if (iter->from > last_accounted_offset) 43684448c8eSJakob Koschel add += hugetlb_resv_map_add(resv, iter->link.prev, 4372103cf9cSPeter Xu last_accounted_offset, 43884448c8eSJakob Koschel iter->from, h, h_cg, 4392103cf9cSPeter Xu regions_needed); 440d75c6af9SMina Almasry 44184448c8eSJakob Koschel last_accounted_offset = iter->to; 4420db9d74eSMina Almasry } 4430db9d74eSMina Almasry 4440db9d74eSMina Almasry /* Handle the case where our range extends beyond 4450db9d74eSMina Almasry * last_accounted_offset. 4460db9d74eSMina Almasry */ 44784448c8eSJakob Koschel if (!rg) 44884448c8eSJakob Koschel rg = head->prev; 4492103cf9cSPeter Xu if (last_accounted_offset < t) 4502103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, 4512103cf9cSPeter Xu t, h, h_cg, regions_needed); 4520db9d74eSMina Almasry 4530db9d74eSMina Almasry return add; 4540db9d74eSMina Almasry } 4550db9d74eSMina Almasry 4560db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4570db9d74eSMina Almasry */ 4580db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4590db9d74eSMina Almasry int regions_needed) 4600db9d74eSMina Almasry __must_hold(&resv->lock) 4610db9d74eSMina Almasry { 46234665341SMiaohe Lin LIST_HEAD(allocated_regions); 4630db9d74eSMina Almasry int to_allocate = 0, i = 0; 4640db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4650db9d74eSMina Almasry 4660db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4670db9d74eSMina Almasry 4680db9d74eSMina Almasry /* 4690db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4700db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 4710db9d74eSMina Almasry * 4720db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 4730db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 4740db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 4750db9d74eSMina Almasry * (adds_in_progress + regions_needed). 4760db9d74eSMina Almasry */ 4770db9d74eSMina Almasry while (resv->region_cache_count < 4780db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 4790db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 4800db9d74eSMina Almasry resv->region_cache_count; 4810db9d74eSMina Almasry 4820db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 483f0953a1bSIngo Molnar * for all the existing adds_in_progress. We should only be 4840db9d74eSMina Almasry * needing to allocate for regions_needed. 4850db9d74eSMina Almasry */ 4860db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 4870db9d74eSMina Almasry 4880db9d74eSMina Almasry spin_unlock(&resv->lock); 4890db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 4900db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 4910db9d74eSMina Almasry if (!trg) 4920db9d74eSMina Almasry goto out_of_memory; 4930db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 4940db9d74eSMina Almasry } 4950db9d74eSMina Almasry 4960db9d74eSMina Almasry spin_lock(&resv->lock); 4970db9d74eSMina Almasry 498d3ec7b6eSWei Yang list_splice(&allocated_regions, &resv->region_cache); 499d3ec7b6eSWei Yang resv->region_cache_count += to_allocate; 5000db9d74eSMina Almasry } 5010db9d74eSMina Almasry 5020db9d74eSMina Almasry return 0; 5030db9d74eSMina Almasry 5040db9d74eSMina Almasry out_of_memory: 5050db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 506d75c6af9SMina Almasry list_del(&rg->link); 507d75c6af9SMina Almasry kfree(rg); 508d75c6af9SMina Almasry } 5090db9d74eSMina Almasry return -ENOMEM; 510d75c6af9SMina Almasry } 511d75c6af9SMina Almasry 5121dd308a7SMike Kravetz /* 5131dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 5140db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 5150db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 5160db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 5170db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 5180db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 519cf3ad20bSMike Kravetz * 5200db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 5210db9d74eSMina Almasry * 5220db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 5230db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 5247c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 5250db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 5260db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 5270db9d74eSMina Almasry * 1 page will only require at most 1 entry. 5281dd308a7SMike Kravetz */ 5290db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 530075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 531075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 53296822904SAndy Whitcroft { 5330db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 53496822904SAndy Whitcroft 5357b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5360db9d74eSMina Almasry retry: 5370db9d74eSMina Almasry 5380db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 539972a3da3SWei Yang add_reservation_in_range(resv, f, t, NULL, NULL, 540972a3da3SWei Yang &actual_regions_needed); 54196822904SAndy Whitcroft 5425e911373SMike Kravetz /* 5430db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 5440db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 5450db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 5460db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 5470db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 5480db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 5490db9d74eSMina Almasry * operation. 5505e911373SMike Kravetz */ 5510db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 5520db9d74eSMina Almasry resv->region_cache_count < 5530db9d74eSMina Almasry resv->adds_in_progress + 5540db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 5550db9d74eSMina Almasry /* region_add operation of range 1 should never need to 5560db9d74eSMina Almasry * allocate file_region entries. 5570db9d74eSMina Almasry */ 5580db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 5595e911373SMike Kravetz 5600db9d74eSMina Almasry if (allocate_file_region_entries( 5610db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 5620db9d74eSMina Almasry return -ENOMEM; 5635e911373SMike Kravetz } 5645e911373SMike Kravetz 5650db9d74eSMina Almasry goto retry; 5660db9d74eSMina Almasry } 567cf3ad20bSMike Kravetz 568972a3da3SWei Yang add = add_reservation_in_range(resv, f, t, h_cg, h, NULL); 5690db9d74eSMina Almasry 5700db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 5710db9d74eSMina Almasry 5727b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 573cf3ad20bSMike Kravetz return add; 57496822904SAndy Whitcroft } 57596822904SAndy Whitcroft 5761dd308a7SMike Kravetz /* 5771dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 5781dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 5791dd308a7SMike Kravetz * represented. This routine is called before a subsequent 5801dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 5811dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 5821dd308a7SMike Kravetz * not change the number of huge pages represented by the 5830db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 5840db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 5850db9d74eSMina Almasry * file_region structure is added. 5860db9d74eSMina Almasry * 5870db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 5880db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 5890db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 5905e911373SMike Kravetz * 5915e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 5925e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 5935e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 5945e911373SMike Kravetz * is needed and can not be allocated. 5951dd308a7SMike Kravetz */ 5960db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 5970db9d74eSMina Almasry long *out_regions_needed) 59896822904SAndy Whitcroft { 59996822904SAndy Whitcroft long chg = 0; 60096822904SAndy Whitcroft 6017b24d861SDavidlohr Bueso spin_lock(&resv->lock); 6025e911373SMike Kravetz 603972a3da3SWei Yang /* Count how many hugepages in this range are NOT represented. */ 604075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 605972a3da3SWei Yang out_regions_needed); 6065e911373SMike Kravetz 6070db9d74eSMina Almasry if (*out_regions_needed == 0) 6080db9d74eSMina Almasry *out_regions_needed = 1; 6095e911373SMike Kravetz 6100db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 6115e911373SMike Kravetz return -ENOMEM; 6125e911373SMike Kravetz 6130db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 61496822904SAndy Whitcroft 6157b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 61696822904SAndy Whitcroft return chg; 61796822904SAndy Whitcroft } 61896822904SAndy Whitcroft 6191dd308a7SMike Kravetz /* 6205e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 6215e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 6225e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 6235e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 6240db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 6250db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 6260db9d74eSMina Almasry * the adds_in_progress counter. 6275e911373SMike Kravetz * 6285e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 6295e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 6305e911373SMike Kravetz * arguments will match the associated region_chg call. 6315e911373SMike Kravetz */ 6320db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 6330db9d74eSMina Almasry long regions_needed) 6345e911373SMike Kravetz { 6355e911373SMike Kravetz spin_lock(&resv->lock); 6365e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 6370db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 6385e911373SMike Kravetz spin_unlock(&resv->lock); 6395e911373SMike Kravetz } 6405e911373SMike Kravetz 6415e911373SMike Kravetz /* 642feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 643feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 644feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 645feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 646feba16e2SMike Kravetz * 647feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 648feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 649feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 650feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 651feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 652feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 653feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 6541dd308a7SMike Kravetz */ 655feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 65696822904SAndy Whitcroft { 6571406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 65896822904SAndy Whitcroft struct file_region *rg, *trg; 659feba16e2SMike Kravetz struct file_region *nrg = NULL; 660feba16e2SMike Kravetz long del = 0; 66196822904SAndy Whitcroft 662feba16e2SMike Kravetz retry: 6637b24d861SDavidlohr Bueso spin_lock(&resv->lock); 664feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 665dbe409e4SMike Kravetz /* 666dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 667dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 668dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 669dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 670dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 671dbe409e4SMike Kravetz */ 672dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 673feba16e2SMike Kravetz continue; 674dbe409e4SMike Kravetz 675feba16e2SMike Kravetz if (rg->from >= t) 67696822904SAndy Whitcroft break; 67796822904SAndy Whitcroft 678feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 679feba16e2SMike Kravetz /* 680feba16e2SMike Kravetz * Check for an entry in the cache before dropping 681feba16e2SMike Kravetz * lock and attempting allocation. 682feba16e2SMike Kravetz */ 683feba16e2SMike Kravetz if (!nrg && 684feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 685feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 686feba16e2SMike Kravetz struct file_region, 687feba16e2SMike Kravetz link); 688feba16e2SMike Kravetz list_del(&nrg->link); 689feba16e2SMike Kravetz resv->region_cache_count--; 69096822904SAndy Whitcroft } 69196822904SAndy Whitcroft 692feba16e2SMike Kravetz if (!nrg) { 693feba16e2SMike Kravetz spin_unlock(&resv->lock); 694feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 695feba16e2SMike Kravetz if (!nrg) 696feba16e2SMike Kravetz return -ENOMEM; 697feba16e2SMike Kravetz goto retry; 698feba16e2SMike Kravetz } 699feba16e2SMike Kravetz 700feba16e2SMike Kravetz del += t - f; 70179aa925bSMike Kravetz hugetlb_cgroup_uncharge_file_region( 702d85aecf2SMiaohe Lin resv, rg, t - f, false); 703feba16e2SMike Kravetz 704feba16e2SMike Kravetz /* New entry for end of split region */ 705feba16e2SMike Kravetz nrg->from = t; 706feba16e2SMike Kravetz nrg->to = rg->to; 707075a61d0SMina Almasry 708075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 709075a61d0SMina Almasry 710feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 711feba16e2SMike Kravetz 712feba16e2SMike Kravetz /* Original entry is trimmed */ 713feba16e2SMike Kravetz rg->to = f; 714feba16e2SMike Kravetz 715feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 716feba16e2SMike Kravetz nrg = NULL; 71796822904SAndy Whitcroft break; 718feba16e2SMike Kravetz } 719feba16e2SMike Kravetz 720feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 721feba16e2SMike Kravetz del += rg->to - rg->from; 722075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 723d85aecf2SMiaohe Lin rg->to - rg->from, true); 72496822904SAndy Whitcroft list_del(&rg->link); 72596822904SAndy Whitcroft kfree(rg); 726feba16e2SMike Kravetz continue; 72796822904SAndy Whitcroft } 7287b24d861SDavidlohr Bueso 729feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 730075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 731d85aecf2SMiaohe Lin t - rg->from, false); 732075a61d0SMina Almasry 73379aa925bSMike Kravetz del += t - rg->from; 73479aa925bSMike Kravetz rg->from = t; 73579aa925bSMike Kravetz } else { /* Trim end of region */ 736075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 737d85aecf2SMiaohe Lin rg->to - f, false); 73879aa925bSMike Kravetz 73979aa925bSMike Kravetz del += rg->to - f; 74079aa925bSMike Kravetz rg->to = f; 741feba16e2SMike Kravetz } 742feba16e2SMike Kravetz } 743feba16e2SMike Kravetz 7447b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 745feba16e2SMike Kravetz kfree(nrg); 746feba16e2SMike Kravetz return del; 74796822904SAndy Whitcroft } 74896822904SAndy Whitcroft 7491dd308a7SMike Kravetz /* 750b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 751b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 752b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 753b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 754b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 755b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 756b5cec28dSMike Kravetz * counts. 757b5cec28dSMike Kravetz */ 75872e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 759b5cec28dSMike Kravetz { 760b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 761b5cec28dSMike Kravetz long rsv_adjust; 762da56388cSMiaohe Lin bool reserved = false; 763b5cec28dSMike Kravetz 764b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 765da56388cSMiaohe Lin if (rsv_adjust > 0) { 766b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 767b5cec28dSMike Kravetz 768da56388cSMiaohe Lin if (!hugetlb_acct_memory(h, 1)) 769da56388cSMiaohe Lin reserved = true; 770da56388cSMiaohe Lin } else if (!rsv_adjust) { 771da56388cSMiaohe Lin reserved = true; 772b5cec28dSMike Kravetz } 773da56388cSMiaohe Lin 774da56388cSMiaohe Lin if (!reserved) 775da56388cSMiaohe Lin pr_warn("hugetlb: Huge Page Reserved count may go negative.\n"); 776b5cec28dSMike Kravetz } 777b5cec28dSMike Kravetz 778b5cec28dSMike Kravetz /* 7791dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 7801dd308a7SMike Kravetz * that intersect with the range [f, t). 7811dd308a7SMike Kravetz */ 7821406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 78384afd99bSAndy Whitcroft { 7841406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 78584afd99bSAndy Whitcroft struct file_region *rg; 78684afd99bSAndy Whitcroft long chg = 0; 78784afd99bSAndy Whitcroft 7887b24d861SDavidlohr Bueso spin_lock(&resv->lock); 78984afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 79084afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 791f2135a4aSWang Sheng-Hui long seg_from; 792f2135a4aSWang Sheng-Hui long seg_to; 79384afd99bSAndy Whitcroft 79484afd99bSAndy Whitcroft if (rg->to <= f) 79584afd99bSAndy Whitcroft continue; 79684afd99bSAndy Whitcroft if (rg->from >= t) 79784afd99bSAndy Whitcroft break; 79884afd99bSAndy Whitcroft 79984afd99bSAndy Whitcroft seg_from = max(rg->from, f); 80084afd99bSAndy Whitcroft seg_to = min(rg->to, t); 80184afd99bSAndy Whitcroft 80284afd99bSAndy Whitcroft chg += seg_to - seg_from; 80384afd99bSAndy Whitcroft } 8047b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 80584afd99bSAndy Whitcroft 80684afd99bSAndy Whitcroft return chg; 80784afd99bSAndy Whitcroft } 80884afd99bSAndy Whitcroft 80996822904SAndy Whitcroft /* 810e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 811e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 812e7c4b0bfSAndy Whitcroft */ 813a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 814a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 815e7c4b0bfSAndy Whitcroft { 816a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 817a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 818e7c4b0bfSAndy Whitcroft } 819e7c4b0bfSAndy Whitcroft 8200fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 8210fe6e20bSNaoya Horiguchi unsigned long address) 8220fe6e20bSNaoya Horiguchi { 8230fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 8240fe6e20bSNaoya Horiguchi } 825dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 8260fe6e20bSNaoya Horiguchi 82784afd99bSAndy Whitcroft /* 82808fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 82908fba699SMel Gorman * cases this will be same size as used by the page table entries. 83008fba699SMel Gorman */ 83108fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 83208fba699SMel Gorman { 83305ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 83405ea8860SDan Williams return vma->vm_ops->pagesize(vma); 83508fba699SMel Gorman return PAGE_SIZE; 83608fba699SMel Gorman } 837f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 83808fba699SMel Gorman 83908fba699SMel Gorman /* 8403340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 8413340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 84209135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 84309135cc5SDan Williams * version of this symbol is required. 8443340289dSMel Gorman */ 84509135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 8463340289dSMel Gorman { 8473340289dSMel Gorman return vma_kernel_pagesize(vma); 8483340289dSMel Gorman } 8493340289dSMel Gorman 8503340289dSMel Gorman /* 85184afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 85284afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 85384afd99bSAndy Whitcroft * alignment. 85484afd99bSAndy Whitcroft */ 85584afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 85684afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 85704f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 85884afd99bSAndy Whitcroft 859a1e78772SMel Gorman /* 860a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 861a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 862a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 863a1e78772SMel Gorman * 8648d9bfb26SMike Kravetz * With the exception of hugetlb_dup_vma_private() which is called at fork(), 865a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 866a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 867a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 86884afd99bSAndy Whitcroft * 86984afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 87084afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 87184afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 87284afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 87384afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 87484afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 87584afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 87684afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 877a1e78772SMel Gorman */ 878e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 879e7c4b0bfSAndy Whitcroft { 880e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 881e7c4b0bfSAndy Whitcroft } 882e7c4b0bfSAndy Whitcroft 883e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 884e7c4b0bfSAndy Whitcroft unsigned long value) 885e7c4b0bfSAndy Whitcroft { 886e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 887e7c4b0bfSAndy Whitcroft } 888e7c4b0bfSAndy Whitcroft 889e9fe92aeSMina Almasry static void 890e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 891e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 892e9fe92aeSMina Almasry struct hstate *h) 893e9fe92aeSMina Almasry { 894e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 895e9fe92aeSMina Almasry if (!h_cg || !h) { 896e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 897e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 898e9fe92aeSMina Almasry resv_map->css = NULL; 899e9fe92aeSMina Almasry } else { 900e9fe92aeSMina Almasry resv_map->reservation_counter = 901e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 902e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 903e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 904e9fe92aeSMina Almasry } 905e9fe92aeSMina Almasry #endif 906e9fe92aeSMina Almasry } 907e9fe92aeSMina Almasry 9089119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 90984afd99bSAndy Whitcroft { 91084afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 9115e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 9125e911373SMike Kravetz 9135e911373SMike Kravetz if (!resv_map || !rg) { 9145e911373SMike Kravetz kfree(resv_map); 9155e911373SMike Kravetz kfree(rg); 91684afd99bSAndy Whitcroft return NULL; 9175e911373SMike Kravetz } 91884afd99bSAndy Whitcroft 91984afd99bSAndy Whitcroft kref_init(&resv_map->refs); 9207b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 92184afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 92284afd99bSAndy Whitcroft 9235e911373SMike Kravetz resv_map->adds_in_progress = 0; 924e9fe92aeSMina Almasry /* 925e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 926e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 927e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 928e9fe92aeSMina Almasry * reservations are to be un-charged from here. 929e9fe92aeSMina Almasry */ 930e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 9315e911373SMike Kravetz 9325e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 9335e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 9345e911373SMike Kravetz resv_map->region_cache_count = 1; 9355e911373SMike Kravetz 93684afd99bSAndy Whitcroft return resv_map; 93784afd99bSAndy Whitcroft } 93884afd99bSAndy Whitcroft 9399119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 94084afd99bSAndy Whitcroft { 94184afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 9425e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 9435e911373SMike Kravetz struct file_region *rg, *trg; 94484afd99bSAndy Whitcroft 94584afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 946feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 9475e911373SMike Kravetz 9485e911373SMike Kravetz /* ... and any entries left in the cache */ 9495e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 9505e911373SMike Kravetz list_del(&rg->link); 9515e911373SMike Kravetz kfree(rg); 9525e911373SMike Kravetz } 9535e911373SMike Kravetz 9545e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 9555e911373SMike Kravetz 95684afd99bSAndy Whitcroft kfree(resv_map); 95784afd99bSAndy Whitcroft } 95884afd99bSAndy Whitcroft 9594e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 9604e35f483SJoonsoo Kim { 961f27a5136SMike Kravetz /* 962f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 963f27a5136SMike Kravetz * address space within the inode. This original address space 964f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 965f27a5136SMike Kravetz * address space embedded within the inode. 966f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 967f27a5136SMike Kravetz * this may not be true for device special inodes. 968f27a5136SMike Kravetz */ 969f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 9704e35f483SJoonsoo Kim } 9714e35f483SJoonsoo Kim 97284afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 973a1e78772SMel Gorman { 97481d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 9754e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 9764e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 9774e35f483SJoonsoo Kim struct inode *inode = mapping->host; 9784e35f483SJoonsoo Kim 9794e35f483SJoonsoo Kim return inode_resv_map(inode); 9804e35f483SJoonsoo Kim 9814e35f483SJoonsoo Kim } else { 98284afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 98384afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 9844e35f483SJoonsoo Kim } 985a1e78772SMel Gorman } 986a1e78772SMel Gorman 98784afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 988a1e78772SMel Gorman { 98981d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 99081d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 991a1e78772SMel Gorman 99284afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 99384afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 99404f2cbe3SMel Gorman } 99504f2cbe3SMel Gorman 99604f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 99704f2cbe3SMel Gorman { 99881d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 99981d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 1000e7c4b0bfSAndy Whitcroft 1001e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 100204f2cbe3SMel Gorman } 100304f2cbe3SMel Gorman 100404f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 100504f2cbe3SMel Gorman { 100681d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1007e7c4b0bfSAndy Whitcroft 1008e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 1009a1e78772SMel Gorman } 1010a1e78772SMel Gorman 10118d9bfb26SMike Kravetz void hugetlb_dup_vma_private(struct vm_area_struct *vma) 1012a1e78772SMel Gorman { 101381d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 10148d9bfb26SMike Kravetz /* 10158d9bfb26SMike Kravetz * Clear vm_private_data 10168d9bfb26SMike Kravetz * - For MAP_PRIVATE mappings, this is the reserve map which does 10178d9bfb26SMike Kravetz * not apply to children. Faults generated by the children are 10188d9bfb26SMike Kravetz * not guaranteed to succeed, even if read-only. 10198d9bfb26SMike Kravetz * - For shared mappings this is a per-vma semaphore that may be 10208d9bfb26SMike Kravetz * allocated in a subsequent call to hugetlb_vm_op_open. 10218d9bfb26SMike Kravetz */ 1022a1e78772SMel Gorman vma->vm_private_data = (void *)0; 10238d9bfb26SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 10248d9bfb26SMike Kravetz return; 1025a1e78772SMel Gorman } 1026a1e78772SMel Gorman 1027550a7d60SMina Almasry /* 1028550a7d60SMina Almasry * Reset and decrement one ref on hugepage private reservation. 1029550a7d60SMina Almasry * Called with mm->mmap_sem writer semaphore held. 1030550a7d60SMina Almasry * This function should be only used by move_vma() and operate on 1031550a7d60SMina Almasry * same sized vma. It should never come here with last ref on the 1032550a7d60SMina Almasry * reservation. 1033550a7d60SMina Almasry */ 1034550a7d60SMina Almasry void clear_vma_resv_huge_pages(struct vm_area_struct *vma) 1035550a7d60SMina Almasry { 1036550a7d60SMina Almasry /* 1037550a7d60SMina Almasry * Clear the old hugetlb private page reservation. 1038550a7d60SMina Almasry * It has already been transferred to new_vma. 1039550a7d60SMina Almasry * 1040550a7d60SMina Almasry * During a mremap() operation of a hugetlb vma we call move_vma() 1041550a7d60SMina Almasry * which copies vma into new_vma and unmaps vma. After the copy 1042550a7d60SMina Almasry * operation both new_vma and vma share a reference to the resv_map 1043550a7d60SMina Almasry * struct, and at that point vma is about to be unmapped. We don't 1044550a7d60SMina Almasry * want to return the reservation to the pool at unmap of vma because 1045550a7d60SMina Almasry * the reservation still lives on in new_vma, so simply decrement the 1046550a7d60SMina Almasry * ref here and remove the resv_map reference from this vma. 1047550a7d60SMina Almasry */ 1048550a7d60SMina Almasry struct resv_map *reservations = vma_resv_map(vma); 1049550a7d60SMina Almasry 1050afe041c2SBui Quang Minh if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 1051afe041c2SBui Quang Minh resv_map_put_hugetlb_cgroup_uncharge_info(reservations); 1052550a7d60SMina Almasry kref_put(&reservations->refs, resv_map_release); 1053afe041c2SBui Quang Minh } 1054550a7d60SMina Almasry 10558d9bfb26SMike Kravetz hugetlb_dup_vma_private(vma); 1056550a7d60SMina Almasry } 1057550a7d60SMina Almasry 1058a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 1059559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 1060a1e78772SMel Gorman { 1061af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 1062af0ed73eSJoonsoo Kim /* 1063af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 1064af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 1065af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 1066af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 1067af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 1068af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 1069af0ed73eSJoonsoo Kim * properly, so add work-around here. 1070af0ed73eSJoonsoo Kim */ 1071af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 1072559ec2f8SNicholas Krause return true; 1073af0ed73eSJoonsoo Kim else 1074559ec2f8SNicholas Krause return false; 1075af0ed73eSJoonsoo Kim } 1076a63884e9SJoonsoo Kim 1077a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 10781fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 10791fb1b0e9SMike Kravetz /* 10801fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 10811fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 10821fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 10837c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 10841fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 10851fb1b0e9SMike Kravetz */ 10861fb1b0e9SMike Kravetz if (chg) 10871fb1b0e9SMike Kravetz return false; 10881fb1b0e9SMike Kravetz else 1089559ec2f8SNicholas Krause return true; 10901fb1b0e9SMike Kravetz } 1091a63884e9SJoonsoo Kim 1092a63884e9SJoonsoo Kim /* 1093a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1094a63884e9SJoonsoo Kim * private mappings. 1095a63884e9SJoonsoo Kim */ 109667961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 109767961f9dSMike Kravetz /* 109867961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 109967961f9dSMike Kravetz * could have been performed on the private mapping. 110067961f9dSMike Kravetz * Examine the value of chg to determine if reserves 110167961f9dSMike Kravetz * actually exist or were previously consumed. 110267961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 110367961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 110467961f9dSMike Kravetz * private mappings has different (opposite) semantics 110567961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 110667961f9dSMike Kravetz * has already taken this difference in semantics into 110767961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 110867961f9dSMike Kravetz * as in the shared case above. Code could easily be 110967961f9dSMike Kravetz * combined, but keeping it separate draws attention to 111067961f9dSMike Kravetz * subtle differences. 111167961f9dSMike Kravetz */ 111267961f9dSMike Kravetz if (chg) 111367961f9dSMike Kravetz return false; 111467961f9dSMike Kravetz else 1115559ec2f8SNicholas Krause return true; 111667961f9dSMike Kravetz } 1117a63884e9SJoonsoo Kim 1118559ec2f8SNicholas Krause return false; 1119a1e78772SMel Gorman } 1120a1e78772SMel Gorman 1121a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 11221da177e4SLinus Torvalds { 11231da177e4SLinus Torvalds int nid = page_to_nid(page); 11249487ca60SMike Kravetz 11259487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1126b65a4edaSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1127b65a4edaSMike Kravetz 11280edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1129a5516438SAndi Kleen h->free_huge_pages++; 1130a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 11316c037149SMike Kravetz SetHPageFreed(page); 11321da177e4SLinus Torvalds } 11331da177e4SLinus Torvalds 113494310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1135bf50bab2SNaoya Horiguchi { 1136bf50bab2SNaoya Horiguchi struct page *page; 11371a08ae36SPavel Tatashin bool pin = !!(current->flags & PF_MEMALLOC_PIN); 1138bf50bab2SNaoya Horiguchi 11399487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1140bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 11416077c943SAlex Sierra if (pin && !is_longterm_pinnable_page(page)) 1142bbe88753SJoonsoo Kim continue; 1143bbe88753SJoonsoo Kim 11446664bfc8SWei Yang if (PageHWPoison(page)) 11456664bfc8SWei Yang continue; 1146bbe88753SJoonsoo Kim 11470edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1148a9869b83SNaoya Horiguchi set_page_refcounted(page); 11496c037149SMike Kravetz ClearHPageFreed(page); 1150bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1151bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1152bf50bab2SNaoya Horiguchi return page; 1153bf50bab2SNaoya Horiguchi } 1154bf50bab2SNaoya Horiguchi 11556664bfc8SWei Yang return NULL; 11566664bfc8SWei Yang } 11576664bfc8SWei Yang 11583e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 11593e59fcb0SMichal Hocko nodemask_t *nmask) 116094310cbcSAnshuman Khandual { 11613e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 11623e59fcb0SMichal Hocko struct zonelist *zonelist; 11633e59fcb0SMichal Hocko struct zone *zone; 11643e59fcb0SMichal Hocko struct zoneref *z; 116598fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 11663e59fcb0SMichal Hocko 11673e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 11683e59fcb0SMichal Hocko 11693e59fcb0SMichal Hocko retry_cpuset: 11703e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 11713e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 117294310cbcSAnshuman Khandual struct page *page; 117394310cbcSAnshuman Khandual 11743e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 11753e59fcb0SMichal Hocko continue; 11763e59fcb0SMichal Hocko /* 11773e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 11783e59fcb0SMichal Hocko * zone aware 11793e59fcb0SMichal Hocko */ 11803e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 11813e59fcb0SMichal Hocko continue; 11823e59fcb0SMichal Hocko node = zone_to_nid(zone); 118394310cbcSAnshuman Khandual 118494310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 118594310cbcSAnshuman Khandual if (page) 118694310cbcSAnshuman Khandual return page; 118794310cbcSAnshuman Khandual } 11883e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 11893e59fcb0SMichal Hocko goto retry_cpuset; 11903e59fcb0SMichal Hocko 119194310cbcSAnshuman Khandual return NULL; 119294310cbcSAnshuman Khandual } 119394310cbcSAnshuman Khandual 1194a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1195a5516438SAndi Kleen struct vm_area_struct *vma, 1196af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1197af0ed73eSJoonsoo Kim long chg) 11981da177e4SLinus Torvalds { 1199cfcaa66fSBen Widawsky struct page *page = NULL; 1200480eccf9SLee Schermerhorn struct mempolicy *mpol; 120104ec6264SVlastimil Babka gfp_t gfp_mask; 12023e59fcb0SMichal Hocko nodemask_t *nodemask; 120304ec6264SVlastimil Babka int nid; 12041da177e4SLinus Torvalds 1205a1e78772SMel Gorman /* 1206a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1207a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1208a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1209a1e78772SMel Gorman */ 1210af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1211a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1212c0ff7453SMiao Xie goto err; 1213a1e78772SMel Gorman 121404f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1215a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 12166eab04a8SJustin P. Mattock goto err; 121704f2cbe3SMel Gorman 121804ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 121904ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 1220cfcaa66fSBen Widawsky 1221cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 12223e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1223cfcaa66fSBen Widawsky 1224cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 1225cfcaa66fSBen Widawsky nodemask = NULL; 1226cfcaa66fSBen Widawsky } 1227cfcaa66fSBen Widawsky 1228cfcaa66fSBen Widawsky if (!page) 1229cfcaa66fSBen Widawsky page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1230cfcaa66fSBen Widawsky 12313e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 1232d6995da3SMike Kravetz SetHPageRestoreReserve(page); 1233a63884e9SJoonsoo Kim h->resv_huge_pages--; 1234bf50bab2SNaoya Horiguchi } 1235cc9a6c87SMel Gorman 1236cc9a6c87SMel Gorman mpol_cond_put(mpol); 1237cc9a6c87SMel Gorman return page; 1238cc9a6c87SMel Gorman 1239c0ff7453SMiao Xie err: 1240cc9a6c87SMel Gorman return NULL; 12411da177e4SLinus Torvalds } 12421da177e4SLinus Torvalds 12431cac6f2cSLuiz Capitulino /* 12441cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 12451cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 12461cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 12471cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 12481cac6f2cSLuiz Capitulino * node for alloc or free. 12491cac6f2cSLuiz Capitulino */ 12501cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 12511cac6f2cSLuiz Capitulino { 12520edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 12531cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 12541cac6f2cSLuiz Capitulino 12551cac6f2cSLuiz Capitulino return nid; 12561cac6f2cSLuiz Capitulino } 12571cac6f2cSLuiz Capitulino 12581cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 12591cac6f2cSLuiz Capitulino { 12601cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 12611cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 12621cac6f2cSLuiz Capitulino return nid; 12631cac6f2cSLuiz Capitulino } 12641cac6f2cSLuiz Capitulino 12651cac6f2cSLuiz Capitulino /* 12661cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 12671cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 12681cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 12691cac6f2cSLuiz Capitulino * mask. 12701cac6f2cSLuiz Capitulino */ 12711cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 12721cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 12731cac6f2cSLuiz Capitulino { 12741cac6f2cSLuiz Capitulino int nid; 12751cac6f2cSLuiz Capitulino 12761cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12771cac6f2cSLuiz Capitulino 12781cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 12791cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 12801cac6f2cSLuiz Capitulino 12811cac6f2cSLuiz Capitulino return nid; 12821cac6f2cSLuiz Capitulino } 12831cac6f2cSLuiz Capitulino 12841cac6f2cSLuiz Capitulino /* 128510c6ec49SMike Kravetz * helper for remove_pool_huge_page() - return the previously saved 12861cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 12871cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 12881cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 12891cac6f2cSLuiz Capitulino */ 12901cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 12911cac6f2cSLuiz Capitulino { 12921cac6f2cSLuiz Capitulino int nid; 12931cac6f2cSLuiz Capitulino 12941cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12951cac6f2cSLuiz Capitulino 12961cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 12971cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 12981cac6f2cSLuiz Capitulino 12991cac6f2cSLuiz Capitulino return nid; 13001cac6f2cSLuiz Capitulino } 13011cac6f2cSLuiz Capitulino 13021cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 13031cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 13041cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 13051cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 13061cac6f2cSLuiz Capitulino nr_nodes--) 13071cac6f2cSLuiz Capitulino 13081cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 13091cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 13101cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 13111cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 13121cac6f2cSLuiz Capitulino nr_nodes--) 13131cac6f2cSLuiz Capitulino 13148531fc6fSMike Kravetz /* used to demote non-gigantic_huge pages as well */ 131534d9e35bSMike Kravetz static void __destroy_compound_gigantic_page(struct page *page, 131634d9e35bSMike Kravetz unsigned int order, bool demote) 1317944d9fecSLuiz Capitulino { 1318944d9fecSLuiz Capitulino int i; 1319944d9fecSLuiz Capitulino int nr_pages = 1 << order; 132014455eabSCheng Li struct page *p; 1321944d9fecSLuiz Capitulino 1322c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 132347e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 132447e29d32SJohn Hubbard 132514455eabSCheng Li for (i = 1; i < nr_pages; i++) { 132614455eabSCheng Li p = nth_page(page, i); 1327a01f4390SMike Kravetz p->mapping = NULL; 13281d798ca3SKirill A. Shutemov clear_compound_head(p); 132934d9e35bSMike Kravetz if (!demote) 1330944d9fecSLuiz Capitulino set_page_refcounted(p); 1331944d9fecSLuiz Capitulino } 1332944d9fecSLuiz Capitulino 1333944d9fecSLuiz Capitulino set_compound_order(page, 0); 13345232c63fSMatthew Wilcox (Oracle) #ifdef CONFIG_64BIT 1335ba9c1201SGerald Schaefer page[1].compound_nr = 0; 13365232c63fSMatthew Wilcox (Oracle) #endif 1337944d9fecSLuiz Capitulino __ClearPageHead(page); 1338944d9fecSLuiz Capitulino } 1339944d9fecSLuiz Capitulino 13408531fc6fSMike Kravetz static void destroy_compound_hugetlb_page_for_demote(struct page *page, 13418531fc6fSMike Kravetz unsigned int order) 13428531fc6fSMike Kravetz { 13438531fc6fSMike Kravetz __destroy_compound_gigantic_page(page, order, true); 13448531fc6fSMike Kravetz } 13458531fc6fSMike Kravetz 13468531fc6fSMike Kravetz #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 134734d9e35bSMike Kravetz static void destroy_compound_gigantic_page(struct page *page, 134834d9e35bSMike Kravetz unsigned int order) 134934d9e35bSMike Kravetz { 135034d9e35bSMike Kravetz __destroy_compound_gigantic_page(page, order, false); 135134d9e35bSMike Kravetz } 135234d9e35bSMike Kravetz 1353d00181b9SKirill A. Shutemov static void free_gigantic_page(struct page *page, unsigned int order) 1354944d9fecSLuiz Capitulino { 1355cf11e85fSRoman Gushchin /* 1356cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1357cf11e85fSRoman Gushchin * cma_release() returns false. 1358cf11e85fSRoman Gushchin */ 1359dbda8feaSBarry Song #ifdef CONFIG_CMA 1360dbda8feaSBarry Song if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)) 1361cf11e85fSRoman Gushchin return; 1362dbda8feaSBarry Song #endif 1363cf11e85fSRoman Gushchin 1364944d9fecSLuiz Capitulino free_contig_range(page_to_pfn(page), 1 << order); 1365944d9fecSLuiz Capitulino } 1366944d9fecSLuiz Capitulino 13674eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 1368d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 1369d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1370944d9fecSLuiz Capitulino { 137104adbc3fSMiaohe Lin unsigned long nr_pages = pages_per_huge_page(h); 1372953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1373953f064aSLi Xinhai nid = numa_mem_id(); 1374944d9fecSLuiz Capitulino 1375dbda8feaSBarry Song #ifdef CONFIG_CMA 1376dbda8feaSBarry Song { 1377cf11e85fSRoman Gushchin struct page *page; 1378cf11e85fSRoman Gushchin int node; 1379cf11e85fSRoman Gushchin 1380953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1381953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1382953f064aSLi Xinhai huge_page_order(h), true); 1383953f064aSLi Xinhai if (page) 1384953f064aSLi Xinhai return page; 1385953f064aSLi Xinhai } 1386953f064aSLi Xinhai 1387953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1388cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1389953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1390cf11e85fSRoman Gushchin continue; 1391cf11e85fSRoman Gushchin 1392cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1393cf11e85fSRoman Gushchin huge_page_order(h), true); 1394cf11e85fSRoman Gushchin if (page) 1395cf11e85fSRoman Gushchin return page; 1396cf11e85fSRoman Gushchin } 1397cf11e85fSRoman Gushchin } 1398953f064aSLi Xinhai } 1399dbda8feaSBarry Song #endif 1400cf11e85fSRoman Gushchin 14015e27a2dfSAnshuman Khandual return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 1402944d9fecSLuiz Capitulino } 1403944d9fecSLuiz Capitulino 14044eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 14054eb0716eSAlexandre Ghiti static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 14064eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 14074eb0716eSAlexandre Ghiti { 14084eb0716eSAlexandre Ghiti return NULL; 14094eb0716eSAlexandre Ghiti } 14104eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1411944d9fecSLuiz Capitulino 1412e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 1413d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 14144eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 14154eb0716eSAlexandre Ghiti { 14164eb0716eSAlexandre Ghiti return NULL; 14174eb0716eSAlexandre Ghiti } 1418d00181b9SKirill A. Shutemov static inline void free_gigantic_page(struct page *page, unsigned int order) { } 1419944d9fecSLuiz Capitulino static inline void destroy_compound_gigantic_page(struct page *page, 1420d00181b9SKirill A. Shutemov unsigned int order) { } 1421944d9fecSLuiz Capitulino #endif 1422944d9fecSLuiz Capitulino 14236eb4e88aSMike Kravetz /* 14246eb4e88aSMike Kravetz * Remove hugetlb page from lists, and update dtor so that page appears 142534d9e35bSMike Kravetz * as just a compound page. 142634d9e35bSMike Kravetz * 142734d9e35bSMike Kravetz * A reference is held on the page, except in the case of demote. 14286eb4e88aSMike Kravetz * 14296eb4e88aSMike Kravetz * Must be called with hugetlb lock held. 14306eb4e88aSMike Kravetz */ 143134d9e35bSMike Kravetz static void __remove_hugetlb_page(struct hstate *h, struct page *page, 143234d9e35bSMike Kravetz bool adjust_surplus, 143334d9e35bSMike Kravetz bool demote) 14346eb4e88aSMike Kravetz { 14356eb4e88aSMike Kravetz int nid = page_to_nid(page); 14366eb4e88aSMike Kravetz 14376eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); 14386eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); 14396eb4e88aSMike Kravetz 14409487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 14416eb4e88aSMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 14426eb4e88aSMike Kravetz return; 14436eb4e88aSMike Kravetz 14446eb4e88aSMike Kravetz list_del(&page->lru); 14456eb4e88aSMike Kravetz 14466eb4e88aSMike Kravetz if (HPageFreed(page)) { 14476eb4e88aSMike Kravetz h->free_huge_pages--; 14486eb4e88aSMike Kravetz h->free_huge_pages_node[nid]--; 14496eb4e88aSMike Kravetz } 14506eb4e88aSMike Kravetz if (adjust_surplus) { 14516eb4e88aSMike Kravetz h->surplus_huge_pages--; 14526eb4e88aSMike Kravetz h->surplus_huge_pages_node[nid]--; 14536eb4e88aSMike Kravetz } 14546eb4e88aSMike Kravetz 1455e32d20c0SMike Kravetz /* 1456e32d20c0SMike Kravetz * Very subtle 1457e32d20c0SMike Kravetz * 1458e32d20c0SMike Kravetz * For non-gigantic pages set the destructor to the normal compound 1459e32d20c0SMike Kravetz * page dtor. This is needed in case someone takes an additional 1460e32d20c0SMike Kravetz * temporary ref to the page, and freeing is delayed until they drop 1461e32d20c0SMike Kravetz * their reference. 1462e32d20c0SMike Kravetz * 1463e32d20c0SMike Kravetz * For gigantic pages set the destructor to the null dtor. This 1464e32d20c0SMike Kravetz * destructor will never be called. Before freeing the gigantic 1465e32d20c0SMike Kravetz * page destroy_compound_gigantic_page will turn the compound page 1466e32d20c0SMike Kravetz * into a simple group of pages. After this the destructor does not 1467e32d20c0SMike Kravetz * apply. 1468e32d20c0SMike Kravetz * 1469e32d20c0SMike Kravetz * This handles the case where more than one ref is held when and 1470e32d20c0SMike Kravetz * after update_and_free_page is called. 147134d9e35bSMike Kravetz * 147234d9e35bSMike Kravetz * In the case of demote we do not ref count the page as it will soon 147334d9e35bSMike Kravetz * be turned into a page of smaller size. 1474e32d20c0SMike Kravetz */ 147534d9e35bSMike Kravetz if (!demote) 14766eb4e88aSMike Kravetz set_page_refcounted(page); 1477e32d20c0SMike Kravetz if (hstate_is_gigantic(h)) 14786eb4e88aSMike Kravetz set_compound_page_dtor(page, NULL_COMPOUND_DTOR); 1479e32d20c0SMike Kravetz else 1480e32d20c0SMike Kravetz set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); 14816eb4e88aSMike Kravetz 14826eb4e88aSMike Kravetz h->nr_huge_pages--; 14836eb4e88aSMike Kravetz h->nr_huge_pages_node[nid]--; 14846eb4e88aSMike Kravetz } 14856eb4e88aSMike Kravetz 148634d9e35bSMike Kravetz static void remove_hugetlb_page(struct hstate *h, struct page *page, 148734d9e35bSMike Kravetz bool adjust_surplus) 148834d9e35bSMike Kravetz { 148934d9e35bSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, false); 149034d9e35bSMike Kravetz } 149134d9e35bSMike Kravetz 14928531fc6fSMike Kravetz static void remove_hugetlb_page_for_demote(struct hstate *h, struct page *page, 14938531fc6fSMike Kravetz bool adjust_surplus) 14948531fc6fSMike Kravetz { 14958531fc6fSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, true); 14968531fc6fSMike Kravetz } 14978531fc6fSMike Kravetz 1498ad2fa371SMuchun Song static void add_hugetlb_page(struct hstate *h, struct page *page, 1499ad2fa371SMuchun Song bool adjust_surplus) 1500ad2fa371SMuchun Song { 1501ad2fa371SMuchun Song int zeroed; 1502ad2fa371SMuchun Song int nid = page_to_nid(page); 1503ad2fa371SMuchun Song 1504ad2fa371SMuchun Song VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page), page); 1505ad2fa371SMuchun Song 1506ad2fa371SMuchun Song lockdep_assert_held(&hugetlb_lock); 1507ad2fa371SMuchun Song 1508ad2fa371SMuchun Song INIT_LIST_HEAD(&page->lru); 1509ad2fa371SMuchun Song h->nr_huge_pages++; 1510ad2fa371SMuchun Song h->nr_huge_pages_node[nid]++; 1511ad2fa371SMuchun Song 1512ad2fa371SMuchun Song if (adjust_surplus) { 1513ad2fa371SMuchun Song h->surplus_huge_pages++; 1514ad2fa371SMuchun Song h->surplus_huge_pages_node[nid]++; 1515ad2fa371SMuchun Song } 1516ad2fa371SMuchun Song 1517ad2fa371SMuchun Song set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1518ad2fa371SMuchun Song set_page_private(page, 0); 1519a9e1eab2SMiaohe Lin /* 1520a9e1eab2SMiaohe Lin * We have to set HPageVmemmapOptimized again as above 1521a9e1eab2SMiaohe Lin * set_page_private(page, 0) cleared it. 1522a9e1eab2SMiaohe Lin */ 1523ad2fa371SMuchun Song SetHPageVmemmapOptimized(page); 1524ad2fa371SMuchun Song 1525ad2fa371SMuchun Song /* 1526b65a4edaSMike Kravetz * This page is about to be managed by the hugetlb allocator and 1527b65a4edaSMike Kravetz * should have no users. Drop our reference, and check for others 1528b65a4edaSMike Kravetz * just in case. 1529ad2fa371SMuchun Song */ 1530ad2fa371SMuchun Song zeroed = put_page_testzero(page); 1531b65a4edaSMike Kravetz if (!zeroed) 1532b65a4edaSMike Kravetz /* 1533b65a4edaSMike Kravetz * It is VERY unlikely soneone else has taken a ref on 1534b65a4edaSMike Kravetz * the page. In this case, we simply return as the 1535b65a4edaSMike Kravetz * hugetlb destructor (free_huge_page) will be called 1536b65a4edaSMike Kravetz * when this other ref is dropped. 1537b65a4edaSMike Kravetz */ 1538b65a4edaSMike Kravetz return; 1539b65a4edaSMike Kravetz 1540ad2fa371SMuchun Song arch_clear_hugepage_flags(page); 1541ad2fa371SMuchun Song enqueue_huge_page(h, page); 1542ad2fa371SMuchun Song } 1543ad2fa371SMuchun Song 1544b65d4adbSMuchun Song static void __update_and_free_page(struct hstate *h, struct page *page) 15456af2acb6SAdam Litke { 15466af2acb6SAdam Litke int i; 154714455eabSCheng Li struct page *subpage; 1548a5516438SAndi Kleen 15494eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1550944d9fecSLuiz Capitulino return; 155118229df5SAndy Whitcroft 1552161df60eSNaoya Horiguchi /* 1553161df60eSNaoya Horiguchi * If we don't know which subpages are hwpoisoned, we can't free 1554161df60eSNaoya Horiguchi * the hugepage, so it's leaked intentionally. 1555161df60eSNaoya Horiguchi */ 1556161df60eSNaoya Horiguchi if (HPageRawHwpUnreliable(page)) 1557161df60eSNaoya Horiguchi return; 1558161df60eSNaoya Horiguchi 15596213834cSMuchun Song if (hugetlb_vmemmap_restore(h, page)) { 1560ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 1561ad2fa371SMuchun Song /* 1562ad2fa371SMuchun Song * If we cannot allocate vmemmap pages, just refuse to free the 1563ad2fa371SMuchun Song * page and put the page back on the hugetlb free list and treat 1564ad2fa371SMuchun Song * as a surplus page. 1565ad2fa371SMuchun Song */ 1566ad2fa371SMuchun Song add_hugetlb_page(h, page, true); 1567ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1568ad2fa371SMuchun Song return; 1569ad2fa371SMuchun Song } 1570ad2fa371SMuchun Song 1571161df60eSNaoya Horiguchi /* 1572161df60eSNaoya Horiguchi * Move PageHWPoison flag from head page to the raw error pages, 1573161df60eSNaoya Horiguchi * which makes any healthy subpages reusable. 1574161df60eSNaoya Horiguchi */ 1575161df60eSNaoya Horiguchi if (unlikely(PageHWPoison(page))) 1576161df60eSNaoya Horiguchi hugetlb_clear_page_hwpoison(page); 1577161df60eSNaoya Horiguchi 157814455eabSCheng Li for (i = 0; i < pages_per_huge_page(h); i++) { 157914455eabSCheng Li subpage = nth_page(page, i); 1580dbfee5aeSMike Kravetz subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 158132f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1582a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1583a7407a27SLuiz Capitulino 1 << PG_writeback); 15846af2acb6SAdam Litke } 1585a01f4390SMike Kravetz 1586a01f4390SMike Kravetz /* 1587a01f4390SMike Kravetz * Non-gigantic pages demoted from CMA allocated gigantic pages 1588a01f4390SMike Kravetz * need to be given back to CMA in free_gigantic_page. 1589a01f4390SMike Kravetz */ 1590a01f4390SMike Kravetz if (hstate_is_gigantic(h) || 1591a01f4390SMike Kravetz hugetlb_cma_page(page, huge_page_order(h))) { 1592944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1593944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1594944d9fecSLuiz Capitulino } else { 1595a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 15966af2acb6SAdam Litke } 1597944d9fecSLuiz Capitulino } 15986af2acb6SAdam Litke 1599b65d4adbSMuchun Song /* 1600b65d4adbSMuchun Song * As update_and_free_page() can be called under any context, so we cannot 1601b65d4adbSMuchun Song * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the 1602b65d4adbSMuchun Song * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate 1603b65d4adbSMuchun Song * the vmemmap pages. 1604b65d4adbSMuchun Song * 1605b65d4adbSMuchun Song * free_hpage_workfn() locklessly retrieves the linked list of pages to be 1606b65d4adbSMuchun Song * freed and frees them one-by-one. As the page->mapping pointer is going 1607b65d4adbSMuchun Song * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node 1608b65d4adbSMuchun Song * structure of a lockless linked list of huge pages to be freed. 1609b65d4adbSMuchun Song */ 1610b65d4adbSMuchun Song static LLIST_HEAD(hpage_freelist); 1611b65d4adbSMuchun Song 1612b65d4adbSMuchun Song static void free_hpage_workfn(struct work_struct *work) 1613b65d4adbSMuchun Song { 1614b65d4adbSMuchun Song struct llist_node *node; 1615b65d4adbSMuchun Song 1616b65d4adbSMuchun Song node = llist_del_all(&hpage_freelist); 1617b65d4adbSMuchun Song 1618b65d4adbSMuchun Song while (node) { 1619b65d4adbSMuchun Song struct page *page; 1620b65d4adbSMuchun Song struct hstate *h; 1621b65d4adbSMuchun Song 1622b65d4adbSMuchun Song page = container_of((struct address_space **)node, 1623b65d4adbSMuchun Song struct page, mapping); 1624b65d4adbSMuchun Song node = node->next; 1625b65d4adbSMuchun Song page->mapping = NULL; 1626b65d4adbSMuchun Song /* 1627b65d4adbSMuchun Song * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate() 1628b65d4adbSMuchun Song * is going to trigger because a previous call to 1629b65d4adbSMuchun Song * remove_hugetlb_page() will set_compound_page_dtor(page, 1630b65d4adbSMuchun Song * NULL_COMPOUND_DTOR), so do not use page_hstate() directly. 1631b65d4adbSMuchun Song */ 1632b65d4adbSMuchun Song h = size_to_hstate(page_size(page)); 1633b65d4adbSMuchun Song 1634b65d4adbSMuchun Song __update_and_free_page(h, page); 1635b65d4adbSMuchun Song 1636b65d4adbSMuchun Song cond_resched(); 1637b65d4adbSMuchun Song } 1638b65d4adbSMuchun Song } 1639b65d4adbSMuchun Song static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1640b65d4adbSMuchun Song 1641b65d4adbSMuchun Song static inline void flush_free_hpage_work(struct hstate *h) 1642b65d4adbSMuchun Song { 16436213834cSMuchun Song if (hugetlb_vmemmap_optimizable(h)) 1644b65d4adbSMuchun Song flush_work(&free_hpage_work); 1645b65d4adbSMuchun Song } 1646b65d4adbSMuchun Song 1647b65d4adbSMuchun Song static void update_and_free_page(struct hstate *h, struct page *page, 1648b65d4adbSMuchun Song bool atomic) 1649b65d4adbSMuchun Song { 1650ad2fa371SMuchun Song if (!HPageVmemmapOptimized(page) || !atomic) { 1651b65d4adbSMuchun Song __update_and_free_page(h, page); 1652b65d4adbSMuchun Song return; 1653b65d4adbSMuchun Song } 1654b65d4adbSMuchun Song 1655b65d4adbSMuchun Song /* 1656b65d4adbSMuchun Song * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages. 1657b65d4adbSMuchun Song * 1658b65d4adbSMuchun Song * Only call schedule_work() if hpage_freelist is previously 1659b65d4adbSMuchun Song * empty. Otherwise, schedule_work() had been called but the workfn 1660b65d4adbSMuchun Song * hasn't retrieved the list yet. 1661b65d4adbSMuchun Song */ 1662b65d4adbSMuchun Song if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist)) 1663b65d4adbSMuchun Song schedule_work(&free_hpage_work); 1664b65d4adbSMuchun Song } 1665b65d4adbSMuchun Song 166610c6ec49SMike Kravetz static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list) 166710c6ec49SMike Kravetz { 166810c6ec49SMike Kravetz struct page *page, *t_page; 166910c6ec49SMike Kravetz 167010c6ec49SMike Kravetz list_for_each_entry_safe(page, t_page, list, lru) { 1671b65d4adbSMuchun Song update_and_free_page(h, page, false); 167210c6ec49SMike Kravetz cond_resched(); 167310c6ec49SMike Kravetz } 167410c6ec49SMike Kravetz } 167510c6ec49SMike Kravetz 1676e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1677e5ff2159SAndi Kleen { 1678e5ff2159SAndi Kleen struct hstate *h; 1679e5ff2159SAndi Kleen 1680e5ff2159SAndi Kleen for_each_hstate(h) { 1681e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1682e5ff2159SAndi Kleen return h; 1683e5ff2159SAndi Kleen } 1684e5ff2159SAndi Kleen return NULL; 1685e5ff2159SAndi Kleen } 1686e5ff2159SAndi Kleen 1687db71ef79SMike Kravetz void free_huge_page(struct page *page) 168827a85ef1SDavid Gibson { 1689a5516438SAndi Kleen /* 1690a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1691a5516438SAndi Kleen * compound page destructor. 1692a5516438SAndi Kleen */ 1693e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 16947893d1d5SAdam Litke int nid = page_to_nid(page); 1695d6995da3SMike Kravetz struct hugepage_subpool *spool = hugetlb_page_subpool(page); 169607443a85SJoonsoo Kim bool restore_reserve; 1697db71ef79SMike Kravetz unsigned long flags; 169827a85ef1SDavid Gibson 1699b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1700b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 17018ace22bcSYongkai Wu 1702d6995da3SMike Kravetz hugetlb_set_page_subpool(page, NULL); 170378fbe906SDavid Hildenbrand if (PageAnon(page)) 170478fbe906SDavid Hildenbrand __ClearPageAnonExclusive(page); 17058ace22bcSYongkai Wu page->mapping = NULL; 1706d6995da3SMike Kravetz restore_reserve = HPageRestoreReserve(page); 1707d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 170827a85ef1SDavid Gibson 17091c5ecae3SMike Kravetz /* 1710d6995da3SMike Kravetz * If HPageRestoreReserve was set on page, page allocation consumed a 17110919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 17120919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 17130919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 17146c26d310SMiaohe Lin * reservation, do not call hugepage_subpool_put_pages() as this will 17150919e1b6SMike Kravetz * remove the reserved page from the subpool. 17160919e1b6SMike Kravetz */ 17170919e1b6SMike Kravetz if (!restore_reserve) { 17180919e1b6SMike Kravetz /* 17190919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 17200919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 17210919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 17220919e1b6SMike Kravetz * operation. 17231c5ecae3SMike Kravetz */ 17241c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 17251c5ecae3SMike Kravetz restore_reserve = true; 17260919e1b6SMike Kravetz } 17271c5ecae3SMike Kravetz 1728db71ef79SMike Kravetz spin_lock_irqsave(&hugetlb_lock, flags); 17298f251a3dSMike Kravetz ClearHPageMigratable(page); 17306d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 17316d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 173208cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 173308cf9fafSMina Almasry pages_per_huge_page(h), page); 173407443a85SJoonsoo Kim if (restore_reserve) 173507443a85SJoonsoo Kim h->resv_huge_pages++; 173607443a85SJoonsoo Kim 17379157c311SMike Kravetz if (HPageTemporary(page)) { 17386eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 1739db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1740b65d4adbSMuchun Song update_and_free_page(h, page, true); 1741ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 17420edaecfaSAneesh Kumar K.V /* remove the page from active list */ 17436eb4e88aSMike Kravetz remove_hugetlb_page(h, page, true); 1744db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1745b65d4adbSMuchun Song update_and_free_page(h, page, true); 17467893d1d5SAdam Litke } else { 17475d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1748a5516438SAndi Kleen enqueue_huge_page(h, page); 1749db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 175027a85ef1SDavid Gibson } 17511121828aSMike Kravetz } 175227a85ef1SDavid Gibson 1753d3d99fccSOscar Salvador /* 1754d3d99fccSOscar Salvador * Must be called with the hugetlb lock held 1755d3d99fccSOscar Salvador */ 1756d3d99fccSOscar Salvador static void __prep_account_new_huge_page(struct hstate *h, int nid) 1757d3d99fccSOscar Salvador { 1758d3d99fccSOscar Salvador lockdep_assert_held(&hugetlb_lock); 1759d3d99fccSOscar Salvador h->nr_huge_pages++; 1760d3d99fccSOscar Salvador h->nr_huge_pages_node[nid]++; 1761d3d99fccSOscar Salvador } 1762d3d99fccSOscar Salvador 1763f41f2ed4SMuchun Song static void __prep_new_huge_page(struct hstate *h, struct page *page) 1764b7ba30c6SAndi Kleen { 17656213834cSMuchun Song hugetlb_vmemmap_optimize(h, page); 17660edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1767f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1768ff546117SMike Kravetz hugetlb_set_page_subpool(page, NULL); 17699dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 17701adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 1771d3d99fccSOscar Salvador } 1772d3d99fccSOscar Salvador 1773d3d99fccSOscar Salvador static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1774d3d99fccSOscar Salvador { 1775f41f2ed4SMuchun Song __prep_new_huge_page(h, page); 1776db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 1777d3d99fccSOscar Salvador __prep_account_new_huge_page(h, nid); 1778db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1779b7ba30c6SAndi Kleen } 1780b7ba30c6SAndi Kleen 178134d9e35bSMike Kravetz static bool __prep_compound_gigantic_page(struct page *page, unsigned int order, 178234d9e35bSMike Kravetz bool demote) 178320a0307cSWu Fengguang { 17847118fc29SMike Kravetz int i, j; 178520a0307cSWu Fengguang int nr_pages = 1 << order; 178614455eabSCheng Li struct page *p; 178720a0307cSWu Fengguang 178820a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 178920a0307cSWu Fengguang set_compound_order(page, order); 1790de09d31dSKirill A. Shutemov __SetPageHead(page); 17912b21624fSMike Kravetz for (i = 0; i < nr_pages; i++) { 179214455eabSCheng Li p = nth_page(page, i); 179314455eabSCheng Li 1794ef5a22beSAndrea Arcangeli /* 1795ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1796ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1797ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 17987c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1799ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1800ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1801ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1802ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1803ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1804ef5a22beSAndrea Arcangeli * after get_user_pages(). 1805ef5a22beSAndrea Arcangeli */ 1806ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 18077118fc29SMike Kravetz /* 18087118fc29SMike Kravetz * Subtle and very unlikely 18097118fc29SMike Kravetz * 18107118fc29SMike Kravetz * Gigantic 'page allocators' such as memblock or cma will 18117118fc29SMike Kravetz * return a set of pages with each page ref counted. We need 18127118fc29SMike Kravetz * to turn this set of pages into a compound page with tail 18137118fc29SMike Kravetz * page ref counts set to zero. Code such as speculative page 18147118fc29SMike Kravetz * cache adding could take a ref on a 'to be' tail page. 18157118fc29SMike Kravetz * We need to respect any increased ref count, and only set 18167118fc29SMike Kravetz * the ref count to zero if count is currently 1. If count 1817416d85edSMike Kravetz * is not 1, we return an error. An error return indicates 1818416d85edSMike Kravetz * the set of pages can not be converted to a gigantic page. 1819416d85edSMike Kravetz * The caller who allocated the pages should then discard the 1820416d85edSMike Kravetz * pages using the appropriate free interface. 182134d9e35bSMike Kravetz * 182234d9e35bSMike Kravetz * In the case of demote, the ref count will be zero. 18237118fc29SMike Kravetz */ 182434d9e35bSMike Kravetz if (!demote) { 18257118fc29SMike Kravetz if (!page_ref_freeze(p, 1)) { 1826416d85edSMike Kravetz pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n"); 18277118fc29SMike Kravetz goto out_error; 18287118fc29SMike Kravetz } 182934d9e35bSMike Kravetz } else { 183034d9e35bSMike Kravetz VM_BUG_ON_PAGE(page_count(p), p); 183134d9e35bSMike Kravetz } 18322b21624fSMike Kravetz if (i != 0) 18331d798ca3SKirill A. Shutemov set_compound_head(p, page); 183420a0307cSWu Fengguang } 1835b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 183647e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 18377118fc29SMike Kravetz return true; 18387118fc29SMike Kravetz 18397118fc29SMike Kravetz out_error: 18402b21624fSMike Kravetz /* undo page modifications made above */ 18412b21624fSMike Kravetz for (j = 0; j < i; j++) { 184214455eabSCheng Li p = nth_page(page, j); 18432b21624fSMike Kravetz if (j != 0) 18447118fc29SMike Kravetz clear_compound_head(p); 18457118fc29SMike Kravetz set_page_refcounted(p); 18467118fc29SMike Kravetz } 18477118fc29SMike Kravetz /* need to clear PG_reserved on remaining tail pages */ 184814455eabSCheng Li for (; j < nr_pages; j++) { 184914455eabSCheng Li p = nth_page(page, j); 18507118fc29SMike Kravetz __ClearPageReserved(p); 185114455eabSCheng Li } 18527118fc29SMike Kravetz set_compound_order(page, 0); 18535232c63fSMatthew Wilcox (Oracle) #ifdef CONFIG_64BIT 18547118fc29SMike Kravetz page[1].compound_nr = 0; 18555232c63fSMatthew Wilcox (Oracle) #endif 18567118fc29SMike Kravetz __ClearPageHead(page); 18577118fc29SMike Kravetz return false; 185820a0307cSWu Fengguang } 185920a0307cSWu Fengguang 186034d9e35bSMike Kravetz static bool prep_compound_gigantic_page(struct page *page, unsigned int order) 186134d9e35bSMike Kravetz { 186234d9e35bSMike Kravetz return __prep_compound_gigantic_page(page, order, false); 186334d9e35bSMike Kravetz } 186434d9e35bSMike Kravetz 18658531fc6fSMike Kravetz static bool prep_compound_gigantic_page_for_demote(struct page *page, 18668531fc6fSMike Kravetz unsigned int order) 18678531fc6fSMike Kravetz { 18688531fc6fSMike Kravetz return __prep_compound_gigantic_page(page, order, true); 18698531fc6fSMike Kravetz } 18708531fc6fSMike Kravetz 18717795912cSAndrew Morton /* 18727795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 18737795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 18747795912cSAndrew Morton * details. 18757795912cSAndrew Morton */ 187620a0307cSWu Fengguang int PageHuge(struct page *page) 187720a0307cSWu Fengguang { 187820a0307cSWu Fengguang if (!PageCompound(page)) 187920a0307cSWu Fengguang return 0; 188020a0307cSWu Fengguang 188120a0307cSWu Fengguang page = compound_head(page); 1882f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 188320a0307cSWu Fengguang } 188443131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 188543131e14SNaoya Horiguchi 188627c73ae7SAndrea Arcangeli /* 188727c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 188827c73ae7SAndrea Arcangeli * normal or transparent huge pages. 188927c73ae7SAndrea Arcangeli */ 189027c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 189127c73ae7SAndrea Arcangeli { 189227c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 189327c73ae7SAndrea Arcangeli return 0; 189427c73ae7SAndrea Arcangeli 1895d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 189627c73ae7SAndrea Arcangeli } 18974e936eccSDavid Howells EXPORT_SYMBOL_GPL(PageHeadHuge); 189827c73ae7SAndrea Arcangeli 1899c0d0381aSMike Kravetz /* 1900c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1901c0d0381aSMike Kravetz * 1902336bf30eSMike Kravetz * Upon entry, the page is locked which means that page_mapping() is 1903336bf30eSMike Kravetz * stable. Due to locking order, we can only trylock_write. If we can 1904336bf30eSMike Kravetz * not get the lock, simply return NULL to caller. 1905c0d0381aSMike Kravetz */ 1906c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1907c0d0381aSMike Kravetz { 1908336bf30eSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1909c0d0381aSMike Kravetz 1910c0d0381aSMike Kravetz if (!mapping) 1911c0d0381aSMike Kravetz return mapping; 1912c0d0381aSMike Kravetz 1913c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1914c0d0381aSMike Kravetz return mapping; 1915c0d0381aSMike Kravetz 1916c0d0381aSMike Kravetz return NULL; 1917c0d0381aSMike Kravetz } 1918c0d0381aSMike Kravetz 1919fe19bd3dSHugh Dickins pgoff_t hugetlb_basepage_index(struct page *page) 192013d60f4bSZhang Yi { 192113d60f4bSZhang Yi struct page *page_head = compound_head(page); 192213d60f4bSZhang Yi pgoff_t index = page_index(page_head); 192313d60f4bSZhang Yi unsigned long compound_idx; 192413d60f4bSZhang Yi 192513d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 192613d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 192713d60f4bSZhang Yi else 192813d60f4bSZhang Yi compound_idx = page - page_head; 192913d60f4bSZhang Yi 193013d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 193113d60f4bSZhang Yi } 193213d60f4bSZhang Yi 19330c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1934f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1935f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19361da177e4SLinus Torvalds { 1937af0fb9dfSMichal Hocko int order = huge_page_order(h); 19381da177e4SLinus Torvalds struct page *page; 1939f60858f9SMike Kravetz bool alloc_try_hard = true; 19402b21624fSMike Kravetz bool retry = true; 1941f96efd58SJoe Jin 1942f60858f9SMike Kravetz /* 1943f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1944f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1945f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1946f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1947f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1948f60858f9SMike Kravetz */ 1949f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1950f60858f9SMike Kravetz alloc_try_hard = false; 1951f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1952f60858f9SMike Kravetz if (alloc_try_hard) 1953f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1954af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1955af0fb9dfSMichal Hocko nid = numa_mem_id(); 19562b21624fSMike Kravetz retry: 195784172f4bSMatthew Wilcox (Oracle) page = __alloc_pages(gfp_mask, order, nid, nmask); 19582b21624fSMike Kravetz 19592b21624fSMike Kravetz /* Freeze head page */ 19602b21624fSMike Kravetz if (page && !page_ref_freeze(page, 1)) { 19612b21624fSMike Kravetz __free_pages(page, order); 19622b21624fSMike Kravetz if (retry) { /* retry once */ 19632b21624fSMike Kravetz retry = false; 19642b21624fSMike Kravetz goto retry; 19652b21624fSMike Kravetz } 19662b21624fSMike Kravetz /* WOW! twice in a row. */ 19672b21624fSMike Kravetz pr_warn("HugeTLB head page unexpected inflated ref count\n"); 19682b21624fSMike Kravetz page = NULL; 19692b21624fSMike Kravetz } 19702b21624fSMike Kravetz 1971af0fb9dfSMichal Hocko if (page) 1972af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1973af0fb9dfSMichal Hocko else 1974af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 197563b4613cSNishanth Aravamudan 1976f60858f9SMike Kravetz /* 1977f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1978f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1979f60858f9SMike Kravetz * normal 'try hard' allocations. 1980f60858f9SMike Kravetz */ 1981f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1982f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1983f60858f9SMike Kravetz 1984f60858f9SMike Kravetz /* 1985f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1986f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1987f60858f9SMike Kravetz * overall state change. 1988f60858f9SMike Kravetz */ 1989f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1990f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1991f60858f9SMike Kravetz 199263b4613cSNishanth Aravamudan return page; 199363b4613cSNishanth Aravamudan } 199463b4613cSNishanth Aravamudan 1995af0fb9dfSMichal Hocko /* 19960c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 19970c397daeSMichal Hocko * should use this function to get new hugetlb pages 19982b21624fSMike Kravetz * 19992b21624fSMike Kravetz * Note that returned page is 'frozen': ref count of head page and all tail 20002b21624fSMike Kravetz * pages is zero. 20010c397daeSMichal Hocko */ 20020c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 2003f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 2004f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 20050c397daeSMichal Hocko { 20060c397daeSMichal Hocko struct page *page; 20077118fc29SMike Kravetz bool retry = false; 20080c397daeSMichal Hocko 20097118fc29SMike Kravetz retry: 20100c397daeSMichal Hocko if (hstate_is_gigantic(h)) 20110c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 20120c397daeSMichal Hocko else 20130c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 2014f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 20150c397daeSMichal Hocko if (!page) 20160c397daeSMichal Hocko return NULL; 20170c397daeSMichal Hocko 20187118fc29SMike Kravetz if (hstate_is_gigantic(h)) { 20197118fc29SMike Kravetz if (!prep_compound_gigantic_page(page, huge_page_order(h))) { 20207118fc29SMike Kravetz /* 20217118fc29SMike Kravetz * Rare failure to convert pages to compound page. 20227118fc29SMike Kravetz * Free pages and try again - ONCE! 20237118fc29SMike Kravetz */ 20247118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 20257118fc29SMike Kravetz if (!retry) { 20267118fc29SMike Kravetz retry = true; 20277118fc29SMike Kravetz goto retry; 20287118fc29SMike Kravetz } 20297118fc29SMike Kravetz return NULL; 20307118fc29SMike Kravetz } 20317118fc29SMike Kravetz } 20320c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 20330c397daeSMichal Hocko 20340c397daeSMichal Hocko return page; 20350c397daeSMichal Hocko } 20360c397daeSMichal Hocko 20370c397daeSMichal Hocko /* 2038af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 2039af0fb9dfSMichal Hocko * manner. 2040af0fb9dfSMichal Hocko */ 2041f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 2042f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 2043b2261026SJoonsoo Kim { 2044b2261026SJoonsoo Kim struct page *page; 2045b2261026SJoonsoo Kim int nr_nodes, node; 2046af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2047b2261026SJoonsoo Kim 2048b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 2049f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 2050f60858f9SMike Kravetz node_alloc_noretry); 2051af0fb9dfSMichal Hocko if (page) 2052b2261026SJoonsoo Kim break; 2053b2261026SJoonsoo Kim } 2054b2261026SJoonsoo Kim 2055af0fb9dfSMichal Hocko if (!page) 2056af0fb9dfSMichal Hocko return 0; 2057b2261026SJoonsoo Kim 20582b21624fSMike Kravetz free_huge_page(page); /* free it into the hugepage allocator */ 2059af0fb9dfSMichal Hocko 2060af0fb9dfSMichal Hocko return 1; 2061b2261026SJoonsoo Kim } 2062b2261026SJoonsoo Kim 2063e8c5c824SLee Schermerhorn /* 206410c6ec49SMike Kravetz * Remove huge page from pool from next node to free. Attempt to keep 206510c6ec49SMike Kravetz * persistent huge pages more or less balanced over allowed nodes. 206610c6ec49SMike Kravetz * This routine only 'removes' the hugetlb page. The caller must make 206710c6ec49SMike Kravetz * an additional call to free the page to low level allocators. 2068e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 2069e8c5c824SLee Schermerhorn */ 207010c6ec49SMike Kravetz static struct page *remove_pool_huge_page(struct hstate *h, 207110c6ec49SMike Kravetz nodemask_t *nodes_allowed, 20726ae11b27SLee Schermerhorn bool acct_surplus) 2073e8c5c824SLee Schermerhorn { 2074b2261026SJoonsoo Kim int nr_nodes, node; 207510c6ec49SMike Kravetz struct page *page = NULL; 2076e8c5c824SLee Schermerhorn 20779487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2078b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2079685f3457SLee Schermerhorn /* 2080685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 2081685f3457SLee Schermerhorn * nodes with surplus pages. 2082685f3457SLee Schermerhorn */ 2083b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 2084b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 208510c6ec49SMike Kravetz page = list_entry(h->hugepage_freelists[node].next, 2086e8c5c824SLee Schermerhorn struct page, lru); 20876eb4e88aSMike Kravetz remove_hugetlb_page(h, page, acct_surplus); 20889a76db09SLee Schermerhorn break; 2089e8c5c824SLee Schermerhorn } 2090b2261026SJoonsoo Kim } 2091e8c5c824SLee Schermerhorn 209210c6ec49SMike Kravetz return page; 2093e8c5c824SLee Schermerhorn } 2094e8c5c824SLee Schermerhorn 2095c8721bbbSNaoya Horiguchi /* 2096c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 2097faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 2098faf53defSNaoya Horiguchi * This function returns values like below: 2099faf53defSNaoya Horiguchi * 2100ad2fa371SMuchun Song * -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages 2101ad2fa371SMuchun Song * when the system is under memory pressure and the feature of 2102ad2fa371SMuchun Song * freeing unused vmemmap pages associated with each hugetlb page 2103ad2fa371SMuchun Song * is enabled. 2104faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 2105faf53defSNaoya Horiguchi * (allocated or reserved.) 2106faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 2107faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 2108c8721bbbSNaoya Horiguchi */ 2109c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 2110c8721bbbSNaoya Horiguchi { 21116bc9b564SNaoya Horiguchi int rc = -EBUSY; 2112082d5b6bSGerald Schaefer 21137ffddd49SMuchun Song retry: 2114faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 2115faf53defSNaoya Horiguchi if (!PageHuge(page)) 2116faf53defSNaoya Horiguchi return 0; 2117faf53defSNaoya Horiguchi 2118db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2119faf53defSNaoya Horiguchi if (!PageHuge(page)) { 2120faf53defSNaoya Horiguchi rc = 0; 2121faf53defSNaoya Horiguchi goto out; 2122faf53defSNaoya Horiguchi } 2123faf53defSNaoya Horiguchi 2124faf53defSNaoya Horiguchi if (!page_count(page)) { 21252247bb33SGerald Schaefer struct page *head = compound_head(page); 21262247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 21276bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 2128082d5b6bSGerald Schaefer goto out; 21297ffddd49SMuchun Song 21307ffddd49SMuchun Song /* 21317ffddd49SMuchun Song * We should make sure that the page is already on the free list 21327ffddd49SMuchun Song * when it is dissolved. 21337ffddd49SMuchun Song */ 21346c037149SMike Kravetz if (unlikely(!HPageFreed(head))) { 2135db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 21367ffddd49SMuchun Song cond_resched(); 21377ffddd49SMuchun Song 21387ffddd49SMuchun Song /* 21397ffddd49SMuchun Song * Theoretically, we should return -EBUSY when we 21407ffddd49SMuchun Song * encounter this race. In fact, we have a chance 21417ffddd49SMuchun Song * to successfully dissolve the page if we do a 21427ffddd49SMuchun Song * retry. Because the race window is quite small. 21437ffddd49SMuchun Song * If we seize this opportunity, it is an optimization 21447ffddd49SMuchun Song * for increasing the success rate of dissolving page. 21457ffddd49SMuchun Song */ 21467ffddd49SMuchun Song goto retry; 21477ffddd49SMuchun Song } 21487ffddd49SMuchun Song 2149ad2fa371SMuchun Song remove_hugetlb_page(h, head, false); 2150ad2fa371SMuchun Song h->max_huge_pages--; 2151ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2152ad2fa371SMuchun Song 2153c3114a84SAnshuman Khandual /* 2154ad2fa371SMuchun Song * Normally update_and_free_page will allocate required vmemmmap 2155ad2fa371SMuchun Song * before freeing the page. update_and_free_page will fail to 2156ad2fa371SMuchun Song * free the page if it can not allocate required vmemmap. We 2157ad2fa371SMuchun Song * need to adjust max_huge_pages if the page is not freed. 2158ad2fa371SMuchun Song * Attempt to allocate vmemmmap here so that we can take 2159ad2fa371SMuchun Song * appropriate action on failure. 2160ad2fa371SMuchun Song */ 21616213834cSMuchun Song rc = hugetlb_vmemmap_restore(h, head); 2162ad2fa371SMuchun Song if (!rc) { 2163b65d4adbSMuchun Song update_and_free_page(h, head, false); 2164ad2fa371SMuchun Song } else { 2165ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 2166ad2fa371SMuchun Song add_hugetlb_page(h, head, false); 2167ad2fa371SMuchun Song h->max_huge_pages++; 2168ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2169ad2fa371SMuchun Song } 2170ad2fa371SMuchun Song 2171ad2fa371SMuchun Song return rc; 2172c8721bbbSNaoya Horiguchi } 2173082d5b6bSGerald Schaefer out: 2174db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2175082d5b6bSGerald Schaefer return rc; 2176c8721bbbSNaoya Horiguchi } 2177c8721bbbSNaoya Horiguchi 2178c8721bbbSNaoya Horiguchi /* 2179c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 2180c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 21812247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 21822247bb33SGerald Schaefer * part of it lies within the given range. 2183082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 2184082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 2185c8721bbbSNaoya Horiguchi */ 2186082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 2187c8721bbbSNaoya Horiguchi { 2188c8721bbbSNaoya Horiguchi unsigned long pfn; 2189eb03aa00SGerald Schaefer struct page *page; 2190082d5b6bSGerald Schaefer int rc = 0; 2191dc2628f3SMuchun Song unsigned int order; 2192dc2628f3SMuchun Song struct hstate *h; 2193c8721bbbSNaoya Horiguchi 2194d0177639SLi Zhong if (!hugepages_supported()) 2195082d5b6bSGerald Schaefer return rc; 2196d0177639SLi Zhong 2197dc2628f3SMuchun Song order = huge_page_order(&default_hstate); 2198dc2628f3SMuchun Song for_each_hstate(h) 2199dc2628f3SMuchun Song order = min(order, huge_page_order(h)); 2200dc2628f3SMuchun Song 2201dc2628f3SMuchun Song for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) { 2202eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 2203eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 2204eb03aa00SGerald Schaefer if (rc) 2205082d5b6bSGerald Schaefer break; 2206eb03aa00SGerald Schaefer } 2207082d5b6bSGerald Schaefer 2208082d5b6bSGerald Schaefer return rc; 2209c8721bbbSNaoya Horiguchi } 2210c8721bbbSNaoya Horiguchi 2211ab5ac90aSMichal Hocko /* 2212ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 2213ab5ac90aSMichal Hocko */ 22140c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 22152b21624fSMike Kravetz int nid, nodemask_t *nmask) 22167893d1d5SAdam Litke { 22179980d744SMichal Hocko struct page *page = NULL; 22187893d1d5SAdam Litke 2219bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2220aa888a74SAndi Kleen return NULL; 2221aa888a74SAndi Kleen 2222db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 22239980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 22249980d744SMichal Hocko goto out_unlock; 2225db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2226d1c3fb1fSNishanth Aravamudan 2227f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 22289980d744SMichal Hocko if (!page) 22290c397daeSMichal Hocko return NULL; 2230d1c3fb1fSNishanth Aravamudan 2231db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 22329980d744SMichal Hocko /* 22339980d744SMichal Hocko * We could have raced with the pool size change. 22349980d744SMichal Hocko * Double check that and simply deallocate the new page 22359980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 22369980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 22379980d744SMichal Hocko * codeflow 22389980d744SMichal Hocko */ 22399980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 22409157c311SMike Kravetz SetHPageTemporary(page); 2241db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22422b21624fSMike Kravetz free_huge_page(page); 22432bf753e6SKai Shen return NULL; 2244b65a4edaSMike Kravetz } 2245b65a4edaSMike Kravetz 22469980d744SMichal Hocko h->surplus_huge_pages++; 22474704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 22489980d744SMichal Hocko 22499980d744SMichal Hocko out_unlock: 2250db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22517893d1d5SAdam Litke 22527893d1d5SAdam Litke return page; 22537893d1d5SAdam Litke } 22547893d1d5SAdam Litke 2255bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 2256ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 2257ab5ac90aSMichal Hocko { 2258ab5ac90aSMichal Hocko struct page *page; 2259ab5ac90aSMichal Hocko 2260ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 2261ab5ac90aSMichal Hocko return NULL; 2262ab5ac90aSMichal Hocko 2263f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 2264ab5ac90aSMichal Hocko if (!page) 2265ab5ac90aSMichal Hocko return NULL; 2266ab5ac90aSMichal Hocko 22672b21624fSMike Kravetz /* fresh huge pages are frozen */ 22682b21624fSMike Kravetz set_page_refcounted(page); 22692b21624fSMike Kravetz 2270ab5ac90aSMichal Hocko /* 2271ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 2272ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 2273ab5ac90aSMichal Hocko */ 22749157c311SMike Kravetz SetHPageTemporary(page); 2275ab5ac90aSMichal Hocko 2276ab5ac90aSMichal Hocko return page; 2277ab5ac90aSMichal Hocko } 2278ab5ac90aSMichal Hocko 2279e4e574b7SAdam Litke /* 2280099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 2281099730d6SDave Hansen */ 2282e0ec90eeSDave Hansen static 22830c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 2284099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 2285099730d6SDave Hansen { 2286cfcaa66fSBen Widawsky struct page *page = NULL; 2287aaf14e40SMichal Hocko struct mempolicy *mpol; 2288aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 2289aaf14e40SMichal Hocko int nid; 2290aaf14e40SMichal Hocko nodemask_t *nodemask; 2291aaf14e40SMichal Hocko 2292aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 2293cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 2294cfcaa66fSBen Widawsky gfp_t gfp = gfp_mask | __GFP_NOWARN; 2295cfcaa66fSBen Widawsky 2296cfcaa66fSBen Widawsky gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); 22972b21624fSMike Kravetz page = alloc_surplus_huge_page(h, gfp, nid, nodemask); 2298cfcaa66fSBen Widawsky 2299cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 2300cfcaa66fSBen Widawsky nodemask = NULL; 2301cfcaa66fSBen Widawsky } 2302cfcaa66fSBen Widawsky 2303cfcaa66fSBen Widawsky if (!page) 23042b21624fSMike Kravetz page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask); 2305aaf14e40SMichal Hocko mpol_cond_put(mpol); 2306aaf14e40SMichal Hocko return page; 2307099730d6SDave Hansen } 2308099730d6SDave Hansen 2309ab5ac90aSMichal Hocko /* page migration callback function */ 23103e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 2311d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 23124db9b2efSMichal Hocko { 2313db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 23144db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 23153e59fcb0SMichal Hocko struct page *page; 23163e59fcb0SMichal Hocko 23173e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 23183e59fcb0SMichal Hocko if (page) { 2319db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23203e59fcb0SMichal Hocko return page; 23214db9b2efSMichal Hocko } 23224db9b2efSMichal Hocko } 2323db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23244db9b2efSMichal Hocko 23250c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 23264db9b2efSMichal Hocko } 23274db9b2efSMichal Hocko 2328ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2329389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2330389c8178SMichal Hocko unsigned long address) 2331ebd63723SMichal Hocko { 2332ebd63723SMichal Hocko struct mempolicy *mpol; 2333ebd63723SMichal Hocko nodemask_t *nodemask; 2334ebd63723SMichal Hocko struct page *page; 2335ebd63723SMichal Hocko gfp_t gfp_mask; 2336ebd63723SMichal Hocko int node; 2337ebd63723SMichal Hocko 2338ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2339ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2340d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2341ebd63723SMichal Hocko mpol_cond_put(mpol); 2342ebd63723SMichal Hocko 2343ebd63723SMichal Hocko return page; 2344ebd63723SMichal Hocko } 2345ebd63723SMichal Hocko 2346bf50bab2SNaoya Horiguchi /* 234725985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2348e4e574b7SAdam Litke * of size 'delta'. 2349e4e574b7SAdam Litke */ 23500a4f3d1bSLiu Xiang static int gather_surplus_pages(struct hstate *h, long delta) 23511b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2352e4e574b7SAdam Litke { 235334665341SMiaohe Lin LIST_HEAD(surplus_list); 2354e4e574b7SAdam Litke struct page *page, *tmp; 23550a4f3d1bSLiu Xiang int ret; 23560a4f3d1bSLiu Xiang long i; 23570a4f3d1bSLiu Xiang long needed, allocated; 235828073b02SHillf Danton bool alloc_ok = true; 2359e4e574b7SAdam Litke 23609487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2361a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2362ac09b3a1SAdam Litke if (needed <= 0) { 2363a5516438SAndi Kleen h->resv_huge_pages += delta; 2364e4e574b7SAdam Litke return 0; 2365ac09b3a1SAdam Litke } 2366e4e574b7SAdam Litke 2367e4e574b7SAdam Litke allocated = 0; 2368e4e574b7SAdam Litke 2369e4e574b7SAdam Litke ret = -ENOMEM; 2370e4e574b7SAdam Litke retry: 2371db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2372e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 23730c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 23742b21624fSMike Kravetz NUMA_NO_NODE, NULL); 237528073b02SHillf Danton if (!page) { 237628073b02SHillf Danton alloc_ok = false; 237728073b02SHillf Danton break; 237828073b02SHillf Danton } 2379e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 238069ed779aSDavid Rientjes cond_resched(); 2381e4e574b7SAdam Litke } 238228073b02SHillf Danton allocated += i; 2383e4e574b7SAdam Litke 2384e4e574b7SAdam Litke /* 2385e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2386e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2387e4e574b7SAdam Litke */ 2388db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2389a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2390a5516438SAndi Kleen (h->free_huge_pages + allocated); 239128073b02SHillf Danton if (needed > 0) { 239228073b02SHillf Danton if (alloc_ok) 2393e4e574b7SAdam Litke goto retry; 239428073b02SHillf Danton /* 239528073b02SHillf Danton * We were not able to allocate enough pages to 239628073b02SHillf Danton * satisfy the entire reservation so we free what 239728073b02SHillf Danton * we've allocated so far. 239828073b02SHillf Danton */ 239928073b02SHillf Danton goto free; 240028073b02SHillf Danton } 2401e4e574b7SAdam Litke /* 2402e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 240325985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2404e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2405ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2406ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2407ac09b3a1SAdam Litke * before they are reserved. 2408e4e574b7SAdam Litke */ 2409e4e574b7SAdam Litke needed += allocated; 2410a5516438SAndi Kleen h->resv_huge_pages += delta; 2411e4e574b7SAdam Litke ret = 0; 2412a9869b83SNaoya Horiguchi 241319fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 241419fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 241519fc3f0aSAdam Litke if ((--needed) < 0) 241619fc3f0aSAdam Litke break; 2417b65a4edaSMike Kravetz /* Add the page to the hugetlb allocator */ 2418a5516438SAndi Kleen enqueue_huge_page(h, page); 241919fc3f0aSAdam Litke } 242028073b02SHillf Danton free: 2421db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 242219fc3f0aSAdam Litke 2423b65a4edaSMike Kravetz /* 2424b65a4edaSMike Kravetz * Free unnecessary surplus pages to the buddy allocator. 2425b65a4edaSMike Kravetz * Pages have no ref count, call free_huge_page directly. 2426b65a4edaSMike Kravetz */ 2427c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2428b65a4edaSMike Kravetz free_huge_page(page); 2429db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2430e4e574b7SAdam Litke 2431e4e574b7SAdam Litke return ret; 2432e4e574b7SAdam Litke } 2433e4e574b7SAdam Litke 2434e4e574b7SAdam Litke /* 2435e5bbc8a6SMike Kravetz * This routine has two main purposes: 2436e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2437e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2438e5bbc8a6SMike Kravetz * to the associated reservation map. 2439e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2440e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2441e4e574b7SAdam Litke */ 2442a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2443a5516438SAndi Kleen unsigned long unused_resv_pages) 2444e4e574b7SAdam Litke { 2445e4e574b7SAdam Litke unsigned long nr_pages; 244610c6ec49SMike Kravetz struct page *page; 244710c6ec49SMike Kravetz LIST_HEAD(page_list); 244810c6ec49SMike Kravetz 24499487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 245010c6ec49SMike Kravetz /* Uncommit the reservation */ 245110c6ec49SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2452e4e574b7SAdam Litke 2453c0531714SNaoya Horiguchi if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 2454e5bbc8a6SMike Kravetz goto out; 2455aa888a74SAndi Kleen 2456e5bbc8a6SMike Kravetz /* 2457e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2458e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2459e5bbc8a6SMike Kravetz */ 2460a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2461e4e574b7SAdam Litke 2462685f3457SLee Schermerhorn /* 2463685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 24649b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 24659b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 24669b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 246710c6ec49SMike Kravetz * remove_pool_huge_page() will balance the freed pages across the 24689b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2469685f3457SLee Schermerhorn */ 2470685f3457SLee Schermerhorn while (nr_pages--) { 247110c6ec49SMike Kravetz page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); 247210c6ec49SMike Kravetz if (!page) 2473e5bbc8a6SMike Kravetz goto out; 247410c6ec49SMike Kravetz 247510c6ec49SMike Kravetz list_add(&page->lru, &page_list); 2476e4e574b7SAdam Litke } 2477e5bbc8a6SMike Kravetz 2478e5bbc8a6SMike Kravetz out: 2479db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 248010c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 2481db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2482e4e574b7SAdam Litke } 2483e4e574b7SAdam Litke 24845e911373SMike Kravetz 2485c37f9fb1SAndy Whitcroft /* 2486feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 24875e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2488cf3ad20bSMike Kravetz * 2489cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2490cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2491cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2492cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2493cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2494feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2495feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2496feba16e2SMike Kravetz * is called in such cases. 2497cf3ad20bSMike Kravetz * 2498cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2499cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2500cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2501cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2502cf3ad20bSMike Kravetz * take appropriate action. 250396b96a96SMike Kravetz * 250496b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 250596b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 250696b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 250796b96a96SMike Kravetz * reservation exists. 2508846be085SMike Kravetz * 2509846be085SMike Kravetz * vma_del_reservation is used in error paths where an entry in the reserve 2510846be085SMike Kravetz * map was created during huge page allocation and must be removed. It is to 2511846be085SMike Kravetz * be called after calling vma_needs_reservation to determine if a reservation 2512846be085SMike Kravetz * exists. 2513c37f9fb1SAndy Whitcroft */ 25145e911373SMike Kravetz enum vma_resv_mode { 25155e911373SMike Kravetz VMA_NEEDS_RESV, 25165e911373SMike Kravetz VMA_COMMIT_RESV, 2517feba16e2SMike Kravetz VMA_END_RESV, 251896b96a96SMike Kravetz VMA_ADD_RESV, 2519846be085SMike Kravetz VMA_DEL_RESV, 25205e911373SMike Kravetz }; 2521cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2522cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 25235e911373SMike Kravetz enum vma_resv_mode mode) 2524c37f9fb1SAndy Whitcroft { 25254e35f483SJoonsoo Kim struct resv_map *resv; 25264e35f483SJoonsoo Kim pgoff_t idx; 2527cf3ad20bSMike Kravetz long ret; 25280db9d74eSMina Almasry long dummy_out_regions_needed; 2529c37f9fb1SAndy Whitcroft 25304e35f483SJoonsoo Kim resv = vma_resv_map(vma); 25314e35f483SJoonsoo Kim if (!resv) 2532c37f9fb1SAndy Whitcroft return 1; 2533c37f9fb1SAndy Whitcroft 25344e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 25355e911373SMike Kravetz switch (mode) { 25365e911373SMike Kravetz case VMA_NEEDS_RESV: 25370db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 25380db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 25390db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 25400db9d74eSMina Almasry * ever require 1 region. 25410db9d74eSMina Almasry */ 25420db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 25435e911373SMike Kravetz break; 25445e911373SMike Kravetz case VMA_COMMIT_RESV: 2545075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25460db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25470db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25485e911373SMike Kravetz break; 2549feba16e2SMike Kravetz case VMA_END_RESV: 25500db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 25515e911373SMike Kravetz ret = 0; 25525e911373SMike Kravetz break; 255396b96a96SMike Kravetz case VMA_ADD_RESV: 25540db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2555075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25560db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25570db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25580db9d74eSMina Almasry } else { 25590db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 256096b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 256196b96a96SMike Kravetz } 256296b96a96SMike Kravetz break; 2563846be085SMike Kravetz case VMA_DEL_RESV: 2564846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 2565846be085SMike Kravetz region_abort(resv, idx, idx + 1, 1); 2566846be085SMike Kravetz ret = region_del(resv, idx, idx + 1); 2567846be085SMike Kravetz } else { 2568846be085SMike Kravetz ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 2569846be085SMike Kravetz /* region_add calls of range 1 should never fail. */ 2570846be085SMike Kravetz VM_BUG_ON(ret < 0); 2571846be085SMike Kravetz } 2572846be085SMike Kravetz break; 25735e911373SMike Kravetz default: 25745e911373SMike Kravetz BUG(); 25755e911373SMike Kravetz } 257684afd99bSAndy Whitcroft 2577846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV) 2578cf3ad20bSMike Kravetz return ret; 257967961f9dSMike Kravetz /* 2580bf3d12b9SMiaohe Lin * We know private mapping must have HPAGE_RESV_OWNER set. 2581bf3d12b9SMiaohe Lin * 258267961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 258367961f9dSMike Kravetz * However, a file associated with mapping could have been 258467961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 258567961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 258667961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 258767961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 258867961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 258967961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 259067961f9dSMike Kravetz * reservation has already been consumed. As a result, the 259167961f9dSMike Kravetz * return value of this routine is the opposite of the 259267961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 259367961f9dSMike Kravetz */ 2594bf3d12b9SMiaohe Lin if (ret > 0) 259567961f9dSMike Kravetz return 0; 2596bf3d12b9SMiaohe Lin if (ret == 0) 259767961f9dSMike Kravetz return 1; 2598bf3d12b9SMiaohe Lin return ret; 259984afd99bSAndy Whitcroft } 2600cf3ad20bSMike Kravetz 2601cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2602a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2603c37f9fb1SAndy Whitcroft { 26045e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2605cf3ad20bSMike Kravetz } 2606c37f9fb1SAndy Whitcroft 2607cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2608cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2609cf3ad20bSMike Kravetz { 26105e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 26115e911373SMike Kravetz } 26125e911373SMike Kravetz 2613feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 26145e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 26155e911373SMike Kravetz { 2616feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2617c37f9fb1SAndy Whitcroft } 2618c37f9fb1SAndy Whitcroft 261996b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 262096b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 262196b96a96SMike Kravetz { 262296b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 262396b96a96SMike Kravetz } 262496b96a96SMike Kravetz 2625846be085SMike Kravetz static long vma_del_reservation(struct hstate *h, 2626846be085SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 262796b96a96SMike Kravetz { 2628846be085SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV); 2629846be085SMike Kravetz } 2630846be085SMike Kravetz 2631846be085SMike Kravetz /* 2632846be085SMike Kravetz * This routine is called to restore reservation information on error paths. 2633846be085SMike Kravetz * It should ONLY be called for pages allocated via alloc_huge_page(), and 2634846be085SMike Kravetz * the hugetlb mutex should remain held when calling this routine. 2635846be085SMike Kravetz * 2636846be085SMike Kravetz * It handles two specific cases: 2637846be085SMike Kravetz * 1) A reservation was in place and the page consumed the reservation. 2638846be085SMike Kravetz * HPageRestoreReserve is set in the page. 2639846be085SMike Kravetz * 2) No reservation was in place for the page, so HPageRestoreReserve is 2640846be085SMike Kravetz * not set. However, alloc_huge_page always updates the reserve map. 2641846be085SMike Kravetz * 2642846be085SMike Kravetz * In case 1, free_huge_page later in the error path will increment the 2643846be085SMike Kravetz * global reserve count. But, free_huge_page does not have enough context 2644846be085SMike Kravetz * to adjust the reservation map. This case deals primarily with private 2645846be085SMike Kravetz * mappings. Adjust the reserve map here to be consistent with global 2646846be085SMike Kravetz * reserve count adjustments to be made by free_huge_page. Make sure the 2647846be085SMike Kravetz * reserve map indicates there is a reservation present. 2648846be085SMike Kravetz * 2649846be085SMike Kravetz * In case 2, simply undo reserve map modifications done by alloc_huge_page. 2650846be085SMike Kravetz */ 2651846be085SMike Kravetz void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, 2652846be085SMike Kravetz unsigned long address, struct page *page) 2653846be085SMike Kravetz { 265496b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 265596b96a96SMike Kravetz 2656846be085SMike Kravetz if (HPageRestoreReserve(page)) { 2657846be085SMike Kravetz if (unlikely(rc < 0)) 265896b96a96SMike Kravetz /* 265996b96a96SMike Kravetz * Rare out of memory condition in reserve map 2660d6995da3SMike Kravetz * manipulation. Clear HPageRestoreReserve so that 266196b96a96SMike Kravetz * global reserve count will not be incremented 266296b96a96SMike Kravetz * by free_huge_page. This will make it appear 266396b96a96SMike Kravetz * as though the reservation for this page was 266496b96a96SMike Kravetz * consumed. This may prevent the task from 266596b96a96SMike Kravetz * faulting in the page at a later time. This 266696b96a96SMike Kravetz * is better than inconsistent global huge page 266796b96a96SMike Kravetz * accounting of reserve counts. 266896b96a96SMike Kravetz */ 2669d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 2670846be085SMike Kravetz else if (rc) 2671846be085SMike Kravetz (void)vma_add_reservation(h, vma, address); 2672846be085SMike Kravetz else 2673846be085SMike Kravetz vma_end_reservation(h, vma, address); 2674846be085SMike Kravetz } else { 2675846be085SMike Kravetz if (!rc) { 267696b96a96SMike Kravetz /* 2677846be085SMike Kravetz * This indicates there is an entry in the reserve map 2678c7b1850dSMike Kravetz * not added by alloc_huge_page. We know it was added 2679846be085SMike Kravetz * before the alloc_huge_page call, otherwise 2680846be085SMike Kravetz * HPageRestoreReserve would be set on the page. 2681846be085SMike Kravetz * Remove the entry so that a subsequent allocation 2682846be085SMike Kravetz * does not consume a reservation. 268396b96a96SMike Kravetz */ 2684846be085SMike Kravetz rc = vma_del_reservation(h, vma, address); 2685846be085SMike Kravetz if (rc < 0) 2686846be085SMike Kravetz /* 2687846be085SMike Kravetz * VERY rare out of memory condition. Since 2688846be085SMike Kravetz * we can not delete the entry, set 2689846be085SMike Kravetz * HPageRestoreReserve so that the reserve 2690846be085SMike Kravetz * count will be incremented when the page 2691846be085SMike Kravetz * is freed. This reserve will be consumed 2692846be085SMike Kravetz * on a subsequent allocation. 2693846be085SMike Kravetz */ 2694846be085SMike Kravetz SetHPageRestoreReserve(page); 2695846be085SMike Kravetz } else if (rc < 0) { 2696846be085SMike Kravetz /* 2697846be085SMike Kravetz * Rare out of memory condition from 2698846be085SMike Kravetz * vma_needs_reservation call. Memory allocation is 2699846be085SMike Kravetz * only attempted if a new entry is needed. Therefore, 2700846be085SMike Kravetz * this implies there is not an entry in the 2701846be085SMike Kravetz * reserve map. 2702846be085SMike Kravetz * 2703846be085SMike Kravetz * For shared mappings, no entry in the map indicates 2704846be085SMike Kravetz * no reservation. We are done. 2705846be085SMike Kravetz */ 2706846be085SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 2707846be085SMike Kravetz /* 2708846be085SMike Kravetz * For private mappings, no entry indicates 2709846be085SMike Kravetz * a reservation is present. Since we can 2710846be085SMike Kravetz * not add an entry, set SetHPageRestoreReserve 2711846be085SMike Kravetz * on the page so reserve count will be 2712846be085SMike Kravetz * incremented when freed. This reserve will 2713846be085SMike Kravetz * be consumed on a subsequent allocation. 2714846be085SMike Kravetz */ 2715846be085SMike Kravetz SetHPageRestoreReserve(page); 271696b96a96SMike Kravetz } else 2717846be085SMike Kravetz /* 2718846be085SMike Kravetz * No reservation present, do nothing 2719846be085SMike Kravetz */ 272096b96a96SMike Kravetz vma_end_reservation(h, vma, address); 272196b96a96SMike Kravetz } 272296b96a96SMike Kravetz } 272396b96a96SMike Kravetz 2724369fa227SOscar Salvador /* 2725369fa227SOscar Salvador * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one 2726369fa227SOscar Salvador * @h: struct hstate old page belongs to 2727369fa227SOscar Salvador * @old_page: Old page to dissolve 2728ae37c7ffSOscar Salvador * @list: List to isolate the page in case we need to 2729369fa227SOscar Salvador * Returns 0 on success, otherwise negated error. 2730369fa227SOscar Salvador */ 2731ae37c7ffSOscar Salvador static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, 2732ae37c7ffSOscar Salvador struct list_head *list) 2733369fa227SOscar Salvador { 2734369fa227SOscar Salvador gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2735369fa227SOscar Salvador int nid = page_to_nid(old_page); 2736369fa227SOscar Salvador struct page *new_page; 2737369fa227SOscar Salvador int ret = 0; 2738369fa227SOscar Salvador 2739369fa227SOscar Salvador /* 2740369fa227SOscar Salvador * Before dissolving the page, we need to allocate a new one for the 2741f41f2ed4SMuchun Song * pool to remain stable. Here, we allocate the page and 'prep' it 2742f41f2ed4SMuchun Song * by doing everything but actually updating counters and adding to 2743f41f2ed4SMuchun Song * the pool. This simplifies and let us do most of the processing 2744f41f2ed4SMuchun Song * under the lock. 2745369fa227SOscar Salvador */ 2746369fa227SOscar Salvador new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL); 2747369fa227SOscar Salvador if (!new_page) 2748369fa227SOscar Salvador return -ENOMEM; 2749f41f2ed4SMuchun Song __prep_new_huge_page(h, new_page); 2750369fa227SOscar Salvador 2751369fa227SOscar Salvador retry: 2752369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2753369fa227SOscar Salvador if (!PageHuge(old_page)) { 2754369fa227SOscar Salvador /* 2755369fa227SOscar Salvador * Freed from under us. Drop new_page too. 2756369fa227SOscar Salvador */ 2757369fa227SOscar Salvador goto free_new; 2758369fa227SOscar Salvador } else if (page_count(old_page)) { 2759369fa227SOscar Salvador /* 2760ae37c7ffSOscar Salvador * Someone has grabbed the page, try to isolate it here. 2761ae37c7ffSOscar Salvador * Fail with -EBUSY if not possible. 2762369fa227SOscar Salvador */ 2763ae37c7ffSOscar Salvador spin_unlock_irq(&hugetlb_lock); 27647ce82f4cSMiaohe Lin ret = isolate_hugetlb(old_page, list); 2765ae37c7ffSOscar Salvador spin_lock_irq(&hugetlb_lock); 2766369fa227SOscar Salvador goto free_new; 2767369fa227SOscar Salvador } else if (!HPageFreed(old_page)) { 2768369fa227SOscar Salvador /* 2769369fa227SOscar Salvador * Page's refcount is 0 but it has not been enqueued in the 2770369fa227SOscar Salvador * freelist yet. Race window is small, so we can succeed here if 2771369fa227SOscar Salvador * we retry. 2772369fa227SOscar Salvador */ 2773369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2774369fa227SOscar Salvador cond_resched(); 2775369fa227SOscar Salvador goto retry; 2776369fa227SOscar Salvador } else { 2777369fa227SOscar Salvador /* 2778369fa227SOscar Salvador * Ok, old_page is still a genuine free hugepage. Remove it from 2779369fa227SOscar Salvador * the freelist and decrease the counters. These will be 2780369fa227SOscar Salvador * incremented again when calling __prep_account_new_huge_page() 2781369fa227SOscar Salvador * and enqueue_huge_page() for new_page. The counters will remain 2782369fa227SOscar Salvador * stable since this happens under the lock. 2783369fa227SOscar Salvador */ 2784369fa227SOscar Salvador remove_hugetlb_page(h, old_page, false); 2785369fa227SOscar Salvador 2786369fa227SOscar Salvador /* 2787b65a4edaSMike Kravetz * Ref count on new page is already zero as it was dropped 2788b65a4edaSMike Kravetz * earlier. It can be directly added to the pool free list. 2789369fa227SOscar Salvador */ 2790369fa227SOscar Salvador __prep_account_new_huge_page(h, nid); 2791369fa227SOscar Salvador enqueue_huge_page(h, new_page); 2792369fa227SOscar Salvador 2793369fa227SOscar Salvador /* 2794369fa227SOscar Salvador * Pages have been replaced, we can safely free the old one. 2795369fa227SOscar Salvador */ 2796369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2797b65d4adbSMuchun Song update_and_free_page(h, old_page, false); 2798369fa227SOscar Salvador } 2799369fa227SOscar Salvador 2800369fa227SOscar Salvador return ret; 2801369fa227SOscar Salvador 2802369fa227SOscar Salvador free_new: 2803369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2804b65a4edaSMike Kravetz /* Page has a zero ref count, but needs a ref to be freed */ 2805b65a4edaSMike Kravetz set_page_refcounted(new_page); 2806b65d4adbSMuchun Song update_and_free_page(h, new_page, false); 2807369fa227SOscar Salvador 2808369fa227SOscar Salvador return ret; 2809369fa227SOscar Salvador } 2810369fa227SOscar Salvador 2811ae37c7ffSOscar Salvador int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list) 2812369fa227SOscar Salvador { 2813369fa227SOscar Salvador struct hstate *h; 2814369fa227SOscar Salvador struct page *head; 2815ae37c7ffSOscar Salvador int ret = -EBUSY; 2816369fa227SOscar Salvador 2817369fa227SOscar Salvador /* 2818369fa227SOscar Salvador * The page might have been dissolved from under our feet, so make sure 2819369fa227SOscar Salvador * to carefully check the state under the lock. 2820369fa227SOscar Salvador * Return success when racing as if we dissolved the page ourselves. 2821369fa227SOscar Salvador */ 2822369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2823369fa227SOscar Salvador if (PageHuge(page)) { 2824369fa227SOscar Salvador head = compound_head(page); 2825369fa227SOscar Salvador h = page_hstate(head); 2826369fa227SOscar Salvador } else { 2827369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2828369fa227SOscar Salvador return 0; 2829369fa227SOscar Salvador } 2830369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2831369fa227SOscar Salvador 2832369fa227SOscar Salvador /* 2833369fa227SOscar Salvador * Fence off gigantic pages as there is a cyclic dependency between 2834369fa227SOscar Salvador * alloc_contig_range and them. Return -ENOMEM as this has the effect 2835369fa227SOscar Salvador * of bailing out right away without further retrying. 2836369fa227SOscar Salvador */ 2837369fa227SOscar Salvador if (hstate_is_gigantic(h)) 2838369fa227SOscar Salvador return -ENOMEM; 2839369fa227SOscar Salvador 28407ce82f4cSMiaohe Lin if (page_count(head) && !isolate_hugetlb(head, list)) 2841ae37c7ffSOscar Salvador ret = 0; 2842ae37c7ffSOscar Salvador else if (!page_count(head)) 2843ae37c7ffSOscar Salvador ret = alloc_and_dissolve_huge_page(h, head, list); 2844ae37c7ffSOscar Salvador 2845ae37c7ffSOscar Salvador return ret; 2846369fa227SOscar Salvador } 2847369fa227SOscar Salvador 284870c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 284904f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2850348ea204SAdam Litke { 285190481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2852a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2853348ea204SAdam Litke struct page *page; 2854d85f69b0SMike Kravetz long map_chg, map_commit; 2855d85f69b0SMike Kravetz long gbl_chg; 28566d76dcf4SAneesh Kumar K.V int ret, idx; 28576d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 285808cf9fafSMina Almasry bool deferred_reserve; 28592fc39cecSAdam Litke 28606d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2861a1e78772SMel Gorman /* 2862d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2863d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2864d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2865a1e78772SMel Gorman */ 2866d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2867d85f69b0SMike Kravetz if (map_chg < 0) 286876dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2869d85f69b0SMike Kravetz 2870d85f69b0SMike Kravetz /* 2871d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2872d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2873d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2874d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2875d85f69b0SMike Kravetz * checked against any subpool limit. 2876d85f69b0SMike Kravetz */ 2877d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2878d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2879d85f69b0SMike Kravetz if (gbl_chg < 0) { 2880feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 288176dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 28825e911373SMike Kravetz } 288390d8b7e6SAdam Litke 2884d85f69b0SMike Kravetz /* 2885d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2886d85f69b0SMike Kravetz * map, there could be reservations associated with the 2887d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2888d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2889d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2890d85f69b0SMike Kravetz * the subpool reservations. 2891d85f69b0SMike Kravetz */ 2892d85f69b0SMike Kravetz if (avoid_reserve) 2893d85f69b0SMike Kravetz gbl_chg = 1; 2894d85f69b0SMike Kravetz } 2895d85f69b0SMike Kravetz 289608cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 289708cf9fafSMina Almasry */ 28986501fe5fSMiaohe Lin deferred_reserve = map_chg || avoid_reserve; 289908cf9fafSMina Almasry if (deferred_reserve) { 290008cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 290108cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 29028f34af6fSJianyu Zhan if (ret) 29038f34af6fSJianyu Zhan goto out_subpool_put; 290408cf9fafSMina Almasry } 290508cf9fafSMina Almasry 290608cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 290708cf9fafSMina Almasry if (ret) 290808cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 29098f34af6fSJianyu Zhan 2910db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2911d85f69b0SMike Kravetz /* 2912d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2913d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2914d85f69b0SMike Kravetz * a reservation exists for the allocation. 2915d85f69b0SMike Kravetz */ 2916d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 291781a6fcaeSJoonsoo Kim if (!page) { 2918db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 29190c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 29208f34af6fSJianyu Zhan if (!page) 29218f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2922a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2923d6995da3SMike Kravetz SetHPageRestoreReserve(page); 2924a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2925a88c7695SNaoya Horiguchi } 2926db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 292715a8d68eSWei Yang list_add(&page->lru, &h->hugepage_activelist); 29282b21624fSMike Kravetz set_page_refcounted(page); 292981a6fcaeSJoonsoo Kim /* Fall through */ 2930a1e78772SMel Gorman } 293181a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 293208cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 293308cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 293408cf9fafSMina Almasry */ 293508cf9fafSMina Almasry if (deferred_reserve) { 293608cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 293708cf9fafSMina Almasry h_cg, page); 293808cf9fafSMina Almasry } 293908cf9fafSMina Almasry 2940db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2941a1e78772SMel Gorman 2942d6995da3SMike Kravetz hugetlb_set_page_subpool(page, spool); 2943a1e78772SMel Gorman 2944d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2945d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 294633039678SMike Kravetz /* 294733039678SMike Kravetz * The page was added to the reservation map between 294833039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 294933039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 295033039678SMike Kravetz * Adjust for the subpool count incremented above AND 295133039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 295233039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 295333039678SMike Kravetz * no longer applies. 295433039678SMike Kravetz */ 295533039678SMike Kravetz long rsv_adjust; 295633039678SMike Kravetz 295733039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 295833039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 295979aa925bSMike Kravetz if (deferred_reserve) 296079aa925bSMike Kravetz hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 296179aa925bSMike Kravetz pages_per_huge_page(h), page); 296233039678SMike Kravetz } 29637893d1d5SAdam Litke return page; 29648f34af6fSJianyu Zhan 29658f34af6fSJianyu Zhan out_uncharge_cgroup: 29668f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 296708cf9fafSMina Almasry out_uncharge_cgroup_reservation: 296808cf9fafSMina Almasry if (deferred_reserve) 296908cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 297008cf9fafSMina Almasry h_cg); 29718f34af6fSJianyu Zhan out_subpool_put: 2972d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 29738f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2974feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 29758f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2976b45b5bd6SDavid Gibson } 2977b45b5bd6SDavid Gibson 2978b5389086SZhenguo Yao int alloc_bootmem_huge_page(struct hstate *h, int nid) 2979e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2980b5389086SZhenguo Yao int __alloc_bootmem_huge_page(struct hstate *h, int nid) 2981aa888a74SAndi Kleen { 2982b5389086SZhenguo Yao struct huge_bootmem_page *m = NULL; /* initialize for clang */ 2983b2261026SJoonsoo Kim int nr_nodes, node; 2984aa888a74SAndi Kleen 2985b5389086SZhenguo Yao /* do node specific alloc */ 2986b5389086SZhenguo Yao if (nid != NUMA_NO_NODE) { 2987b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), 2988b5389086SZhenguo Yao 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid); 2989b5389086SZhenguo Yao if (!m) 2990b5389086SZhenguo Yao return 0; 2991b5389086SZhenguo Yao goto found; 2992b5389086SZhenguo Yao } 2993b5389086SZhenguo Yao /* allocate from next node when distributing huge pages */ 2994b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 2995b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw( 29968b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 299797ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 2998aa888a74SAndi Kleen /* 2999aa888a74SAndi Kleen * Use the beginning of the huge page to store the 3000aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 3001aa888a74SAndi Kleen * puts them into the mem_map). 3002aa888a74SAndi Kleen */ 3003b5389086SZhenguo Yao if (!m) 3004b5389086SZhenguo Yao return 0; 3005aa888a74SAndi Kleen goto found; 3006aa888a74SAndi Kleen } 3007aa888a74SAndi Kleen 3008aa888a74SAndi Kleen found: 3009aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 3010330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 3011aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 3012aa888a74SAndi Kleen m->hstate = h; 3013aa888a74SAndi Kleen return 1; 3014aa888a74SAndi Kleen } 3015aa888a74SAndi Kleen 301648b8d744SMike Kravetz /* 301748b8d744SMike Kravetz * Put bootmem huge pages into the standard lists after mem_map is up. 301848b8d744SMike Kravetz * Note: This only applies to gigantic (order > MAX_ORDER) pages. 301948b8d744SMike Kravetz */ 3020aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 3021aa888a74SAndi Kleen { 3022aa888a74SAndi Kleen struct huge_bootmem_page *m; 3023aa888a74SAndi Kleen 3024aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 302540d18ebfSMike Kravetz struct page *page = virt_to_page(m); 3026aa888a74SAndi Kleen struct hstate *h = m->hstate; 3027ee8f248dSBecky Bruce 302848b8d744SMike Kravetz VM_BUG_ON(!hstate_is_gigantic(h)); 3029aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 30307118fc29SMike Kravetz if (prep_compound_gigantic_page(page, huge_page_order(h))) { 3031ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 3032aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 30332b21624fSMike Kravetz free_huge_page(page); /* add to the hugepage allocator */ 30347118fc29SMike Kravetz } else { 3035416d85edSMike Kravetz /* VERY unlikely inflated ref count on a tail page */ 30367118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 30377118fc29SMike Kravetz } 3038af0fb9dfSMichal Hocko 3039b0320c7bSRafael Aquini /* 304048b8d744SMike Kravetz * We need to restore the 'stolen' pages to totalram_pages 304148b8d744SMike Kravetz * in order to fix confusing memory reports from free(1) and 304248b8d744SMike Kravetz * other side-effects, like CommitLimit going negative. 3043b0320c7bSRafael Aquini */ 3044c78a7f36SMiaohe Lin adjust_managed_page_count(page, pages_per_huge_page(h)); 3045520495feSCannon Matthews cond_resched(); 3046aa888a74SAndi Kleen } 3047aa888a74SAndi Kleen } 3048b5389086SZhenguo Yao static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid) 3049b5389086SZhenguo Yao { 3050b5389086SZhenguo Yao unsigned long i; 3051b5389086SZhenguo Yao char buf[32]; 3052b5389086SZhenguo Yao 3053b5389086SZhenguo Yao for (i = 0; i < h->max_huge_pages_node[nid]; ++i) { 3054b5389086SZhenguo Yao if (hstate_is_gigantic(h)) { 3055b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, nid)) 3056b5389086SZhenguo Yao break; 3057b5389086SZhenguo Yao } else { 3058b5389086SZhenguo Yao struct page *page; 3059b5389086SZhenguo Yao gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 3060b5389086SZhenguo Yao 3061b5389086SZhenguo Yao page = alloc_fresh_huge_page(h, gfp_mask, nid, 3062b5389086SZhenguo Yao &node_states[N_MEMORY], NULL); 3063b5389086SZhenguo Yao if (!page) 3064b5389086SZhenguo Yao break; 30652b21624fSMike Kravetz free_huge_page(page); /* free it into the hugepage allocator */ 3066b5389086SZhenguo Yao } 3067b5389086SZhenguo Yao cond_resched(); 3068b5389086SZhenguo Yao } 3069b5389086SZhenguo Yao if (i == h->max_huge_pages_node[nid]) 3070b5389086SZhenguo Yao return; 3071b5389086SZhenguo Yao 3072b5389086SZhenguo Yao string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3073b5389086SZhenguo Yao pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n", 3074b5389086SZhenguo Yao h->max_huge_pages_node[nid], buf, nid, i); 3075b5389086SZhenguo Yao h->max_huge_pages -= (h->max_huge_pages_node[nid] - i); 3076b5389086SZhenguo Yao h->max_huge_pages_node[nid] = i; 3077b5389086SZhenguo Yao } 3078aa888a74SAndi Kleen 30798faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 30801da177e4SLinus Torvalds { 30811da177e4SLinus Torvalds unsigned long i; 3082f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 3083b5389086SZhenguo Yao bool node_specific_alloc = false; 3084f60858f9SMike Kravetz 3085b5389086SZhenguo Yao /* skip gigantic hugepages allocation if hugetlb_cma enabled */ 3086b5389086SZhenguo Yao if (hstate_is_gigantic(h) && hugetlb_cma_size) { 3087b5389086SZhenguo Yao pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 3088b5389086SZhenguo Yao return; 3089b5389086SZhenguo Yao } 3090b5389086SZhenguo Yao 3091b5389086SZhenguo Yao /* do node specific alloc */ 30920a7a0f6fSPeng Liu for_each_online_node(i) { 3093b5389086SZhenguo Yao if (h->max_huge_pages_node[i] > 0) { 3094b5389086SZhenguo Yao hugetlb_hstate_alloc_pages_onenode(h, i); 3095b5389086SZhenguo Yao node_specific_alloc = true; 3096b5389086SZhenguo Yao } 3097b5389086SZhenguo Yao } 3098b5389086SZhenguo Yao 3099b5389086SZhenguo Yao if (node_specific_alloc) 3100b5389086SZhenguo Yao return; 3101b5389086SZhenguo Yao 3102b5389086SZhenguo Yao /* below will do all node balanced alloc */ 3103f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 3104f60858f9SMike Kravetz /* 3105f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3106f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 3107f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 3108f60858f9SMike Kravetz * time, we are likely in bigger trouble. 3109f60858f9SMike Kravetz */ 3110f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 3111f60858f9SMike Kravetz GFP_KERNEL); 3112f60858f9SMike Kravetz } else { 3113f60858f9SMike Kravetz /* allocations done at boot time */ 3114f60858f9SMike Kravetz node_alloc_noretry = NULL; 3115f60858f9SMike Kravetz } 3116f60858f9SMike Kravetz 3117f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 3118f60858f9SMike Kravetz if (node_alloc_noretry) 3119f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 31201da177e4SLinus Torvalds 3121e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 3122bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 3123b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, NUMA_NO_NODE)) 3124aa888a74SAndi Kleen break; 31250c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 3126f60858f9SMike Kravetz &node_states[N_MEMORY], 3127f60858f9SMike Kravetz node_alloc_noretry)) 31281da177e4SLinus Torvalds break; 312969ed779aSDavid Rientjes cond_resched(); 31301da177e4SLinus Torvalds } 3131d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 3132d715cf80SLiam R. Howlett char buf[32]; 3133d715cf80SLiam R. Howlett 3134c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3135d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 3136d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 31378faa8b07SAndi Kleen h->max_huge_pages = i; 3138e5ff2159SAndi Kleen } 3139f60858f9SMike Kravetz kfree(node_alloc_noretry); 3140d715cf80SLiam R. Howlett } 3141e5ff2159SAndi Kleen 3142e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 3143e5ff2159SAndi Kleen { 314479dfc695SMike Kravetz struct hstate *h, *h2; 3145e5ff2159SAndi Kleen 3146e5ff2159SAndi Kleen for_each_hstate(h) { 31478faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 3148bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 31498faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 315079dfc695SMike Kravetz 315179dfc695SMike Kravetz /* 315279dfc695SMike Kravetz * Set demote order for each hstate. Note that 315379dfc695SMike Kravetz * h->demote_order is initially 0. 315479dfc695SMike Kravetz * - We can not demote gigantic pages if runtime freeing 315579dfc695SMike Kravetz * is not supported, so skip this. 3156a01f4390SMike Kravetz * - If CMA allocation is possible, we can not demote 3157a01f4390SMike Kravetz * HUGETLB_PAGE_ORDER or smaller size pages. 315879dfc695SMike Kravetz */ 315979dfc695SMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 316079dfc695SMike Kravetz continue; 3161a01f4390SMike Kravetz if (hugetlb_cma_size && h->order <= HUGETLB_PAGE_ORDER) 3162a01f4390SMike Kravetz continue; 316379dfc695SMike Kravetz for_each_hstate(h2) { 316479dfc695SMike Kravetz if (h2 == h) 316579dfc695SMike Kravetz continue; 316679dfc695SMike Kravetz if (h2->order < h->order && 316779dfc695SMike Kravetz h2->order > h->demote_order) 316879dfc695SMike Kravetz h->demote_order = h2->order; 316979dfc695SMike Kravetz } 3170e5ff2159SAndi Kleen } 3171e5ff2159SAndi Kleen } 3172e5ff2159SAndi Kleen 3173e5ff2159SAndi Kleen static void __init report_hugepages(void) 3174e5ff2159SAndi Kleen { 3175e5ff2159SAndi Kleen struct hstate *h; 3176e5ff2159SAndi Kleen 3177e5ff2159SAndi Kleen for_each_hstate(h) { 31784abd32dbSAndi Kleen char buf[32]; 3179c6247f72SMatthew Wilcox 3180c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 31816213834cSMuchun Song pr_info("HugeTLB: registered %s page size, pre-allocated %ld pages\n", 3182c6247f72SMatthew Wilcox buf, h->free_huge_pages); 31836213834cSMuchun Song pr_info("HugeTLB: %d KiB vmemmap can be freed for a %s page\n", 31846213834cSMuchun Song hugetlb_vmemmap_optimizable_size(h) / SZ_1K, buf); 3185e5ff2159SAndi Kleen } 3186e5ff2159SAndi Kleen } 3187e5ff2159SAndi Kleen 31881da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 31896ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 31906ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 31911da177e4SLinus Torvalds { 31924415cc8dSChristoph Lameter int i; 31931121828aSMike Kravetz LIST_HEAD(page_list); 31944415cc8dSChristoph Lameter 31959487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 3196bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3197aa888a74SAndi Kleen return; 3198aa888a74SAndi Kleen 31991121828aSMike Kravetz /* 32001121828aSMike Kravetz * Collect pages to be freed on a list, and free after dropping lock 32011121828aSMike Kravetz */ 32026ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 320310c6ec49SMike Kravetz struct page *page, *next; 3204a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 3205a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 3206a5516438SAndi Kleen if (count >= h->nr_huge_pages) 32071121828aSMike Kravetz goto out; 32081da177e4SLinus Torvalds if (PageHighMem(page)) 32091da177e4SLinus Torvalds continue; 32106eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 32111121828aSMike Kravetz list_add(&page->lru, &page_list); 32121121828aSMike Kravetz } 32131121828aSMike Kravetz } 32141121828aSMike Kravetz 32151121828aSMike Kravetz out: 3216db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 321710c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3218db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32191da177e4SLinus Torvalds } 32201da177e4SLinus Torvalds #else 32216ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 32226ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32231da177e4SLinus Torvalds { 32241da177e4SLinus Torvalds } 32251da177e4SLinus Torvalds #endif 32261da177e4SLinus Torvalds 322720a0307cSWu Fengguang /* 322820a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 322920a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 323020a0307cSWu Fengguang * Returns 1 if an adjustment was made. 323120a0307cSWu Fengguang */ 32326ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 32336ae11b27SLee Schermerhorn int delta) 323420a0307cSWu Fengguang { 3235b2261026SJoonsoo Kim int nr_nodes, node; 323620a0307cSWu Fengguang 32379487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 323820a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 323920a0307cSWu Fengguang 3240e8c5c824SLee Schermerhorn if (delta < 0) { 3241b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 3242b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 3243b2261026SJoonsoo Kim goto found; 3244b2261026SJoonsoo Kim } 3245b2261026SJoonsoo Kim } else { 3246b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 3247b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 3248b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 3249b2261026SJoonsoo Kim goto found; 3250e8c5c824SLee Schermerhorn } 32519a76db09SLee Schermerhorn } 3252b2261026SJoonsoo Kim return 0; 325320a0307cSWu Fengguang 3254b2261026SJoonsoo Kim found: 325520a0307cSWu Fengguang h->surplus_huge_pages += delta; 3256b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 3257b2261026SJoonsoo Kim return 1; 325820a0307cSWu Fengguang } 325920a0307cSWu Fengguang 3260a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 3261fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 32626ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32631da177e4SLinus Torvalds { 32647893d1d5SAdam Litke unsigned long min_count, ret; 326510c6ec49SMike Kravetz struct page *page; 326610c6ec49SMike Kravetz LIST_HEAD(page_list); 3267f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 3268f60858f9SMike Kravetz 3269f60858f9SMike Kravetz /* 3270f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3271f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 3272f60858f9SMike Kravetz * the requested huge pages. 3273f60858f9SMike Kravetz */ 3274f60858f9SMike Kravetz if (node_alloc_noretry) 3275f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 3276f60858f9SMike Kravetz else 3277f60858f9SMike Kravetz return -ENOMEM; 32781da177e4SLinus Torvalds 327929383967SMike Kravetz /* 328029383967SMike Kravetz * resize_lock mutex prevents concurrent adjustments to number of 328129383967SMike Kravetz * pages in hstate via the proc/sysfs interfaces. 328229383967SMike Kravetz */ 328329383967SMike Kravetz mutex_lock(&h->resize_lock); 3284b65d4adbSMuchun Song flush_free_hpage_work(h); 3285db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32864eb0716eSAlexandre Ghiti 32874eb0716eSAlexandre Ghiti /* 3288fd875dcaSMike Kravetz * Check for a node specific request. 3289fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 3290fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 3291fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 3292fd875dcaSMike Kravetz */ 3293fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 3294fd875dcaSMike Kravetz unsigned long old_count = count; 3295fd875dcaSMike Kravetz 3296fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 3297fd875dcaSMike Kravetz /* 3298fd875dcaSMike Kravetz * User may have specified a large count value which caused the 3299fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 3300fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 3301fd875dcaSMike Kravetz * largest possible value to align with their intention. 3302fd875dcaSMike Kravetz */ 3303fd875dcaSMike Kravetz if (count < old_count) 3304fd875dcaSMike Kravetz count = ULONG_MAX; 3305fd875dcaSMike Kravetz } 3306fd875dcaSMike Kravetz 3307fd875dcaSMike Kravetz /* 33084eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 33094eb0716eSAlexandre Ghiti * page range allocation. 33104eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 33114eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 33124eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 33134eb0716eSAlexandre Ghiti */ 33144eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 33154eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 3316db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 331729383967SMike Kravetz mutex_unlock(&h->resize_lock); 3318f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 33194eb0716eSAlexandre Ghiti return -EINVAL; 33204eb0716eSAlexandre Ghiti } 33214eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 33224eb0716eSAlexandre Ghiti } 3323aa888a74SAndi Kleen 33247893d1d5SAdam Litke /* 33257893d1d5SAdam Litke * Increase the pool size 33267893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 33277893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 3328d1c3fb1fSNishanth Aravamudan * 33290c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 3330d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 3331d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 3332d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 3333d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 33347893d1d5SAdam Litke */ 3335a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 33366ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 33377893d1d5SAdam Litke break; 33387893d1d5SAdam Litke } 33397893d1d5SAdam Litke 3340a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 33417893d1d5SAdam Litke /* 33427893d1d5SAdam Litke * If this allocation races such that we no longer need the 33437893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 33447893d1d5SAdam Litke * and reducing the surplus. 33457893d1d5SAdam Litke */ 3346db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3347649920c6SJia He 3348649920c6SJia He /* yield cpu to avoid soft lockup */ 3349649920c6SJia He cond_resched(); 3350649920c6SJia He 3351f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 3352f60858f9SMike Kravetz node_alloc_noretry); 3353db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 33547893d1d5SAdam Litke if (!ret) 33557893d1d5SAdam Litke goto out; 33567893d1d5SAdam Litke 3357536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 3358536240f2SMel Gorman if (signal_pending(current)) 3359536240f2SMel Gorman goto out; 33607893d1d5SAdam Litke } 33617893d1d5SAdam Litke 33627893d1d5SAdam Litke /* 33637893d1d5SAdam Litke * Decrease the pool size 33647893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 33657893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 33667893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 33677893d1d5SAdam Litke * to the desired size as pages become free. 3368d1c3fb1fSNishanth Aravamudan * 3369d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 3370d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 3371d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 33720c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 3373d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 3374d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 3375d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 33767893d1d5SAdam Litke */ 3377a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 33786b0c880dSAdam Litke min_count = max(count, min_count); 33796ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 338010c6ec49SMike Kravetz 338110c6ec49SMike Kravetz /* 338210c6ec49SMike Kravetz * Collect pages to be removed on list without dropping lock 338310c6ec49SMike Kravetz */ 3384a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 338510c6ec49SMike Kravetz page = remove_pool_huge_page(h, nodes_allowed, 0); 338610c6ec49SMike Kravetz if (!page) 33871da177e4SLinus Torvalds break; 338810c6ec49SMike Kravetz 338910c6ec49SMike Kravetz list_add(&page->lru, &page_list); 33901da177e4SLinus Torvalds } 339110c6ec49SMike Kravetz /* free the pages after dropping lock */ 3392db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 339310c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3394b65d4adbSMuchun Song flush_free_hpage_work(h); 3395db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 339610c6ec49SMike Kravetz 3397a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 33986ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 33997893d1d5SAdam Litke break; 34007893d1d5SAdam Litke } 34017893d1d5SAdam Litke out: 34024eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 3403db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 340429383967SMike Kravetz mutex_unlock(&h->resize_lock); 34054eb0716eSAlexandre Ghiti 3406f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 3407f60858f9SMike Kravetz 34084eb0716eSAlexandre Ghiti return 0; 34091da177e4SLinus Torvalds } 34101da177e4SLinus Torvalds 34118531fc6fSMike Kravetz static int demote_free_huge_page(struct hstate *h, struct page *page) 34128531fc6fSMike Kravetz { 34138531fc6fSMike Kravetz int i, nid = page_to_nid(page); 34148531fc6fSMike Kravetz struct hstate *target_hstate; 341531731452SDoug Berger struct page *subpage; 34168531fc6fSMike Kravetz int rc = 0; 34178531fc6fSMike Kravetz 34188531fc6fSMike Kravetz target_hstate = size_to_hstate(PAGE_SIZE << h->demote_order); 34198531fc6fSMike Kravetz 34208531fc6fSMike Kravetz remove_hugetlb_page_for_demote(h, page, false); 34218531fc6fSMike Kravetz spin_unlock_irq(&hugetlb_lock); 34228531fc6fSMike Kravetz 34236213834cSMuchun Song rc = hugetlb_vmemmap_restore(h, page); 34248531fc6fSMike Kravetz if (rc) { 34258531fc6fSMike Kravetz /* Allocation of vmemmmap failed, we can not demote page */ 34268531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34278531fc6fSMike Kravetz set_page_refcounted(page); 34288531fc6fSMike Kravetz add_hugetlb_page(h, page, false); 34298531fc6fSMike Kravetz return rc; 34308531fc6fSMike Kravetz } 34318531fc6fSMike Kravetz 34328531fc6fSMike Kravetz /* 34338531fc6fSMike Kravetz * Use destroy_compound_hugetlb_page_for_demote for all huge page 34348531fc6fSMike Kravetz * sizes as it will not ref count pages. 34358531fc6fSMike Kravetz */ 34368531fc6fSMike Kravetz destroy_compound_hugetlb_page_for_demote(page, huge_page_order(h)); 34378531fc6fSMike Kravetz 34388531fc6fSMike Kravetz /* 34398531fc6fSMike Kravetz * Taking target hstate mutex synchronizes with set_max_huge_pages. 34408531fc6fSMike Kravetz * Without the mutex, pages added to target hstate could be marked 34418531fc6fSMike Kravetz * as surplus. 34428531fc6fSMike Kravetz * 34438531fc6fSMike Kravetz * Note that we already hold h->resize_lock. To prevent deadlock, 34448531fc6fSMike Kravetz * use the convention of always taking larger size hstate mutex first. 34458531fc6fSMike Kravetz */ 34468531fc6fSMike Kravetz mutex_lock(&target_hstate->resize_lock); 34478531fc6fSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 34488531fc6fSMike Kravetz i += pages_per_huge_page(target_hstate)) { 344931731452SDoug Berger subpage = nth_page(page, i); 34508531fc6fSMike Kravetz if (hstate_is_gigantic(target_hstate)) 345131731452SDoug Berger prep_compound_gigantic_page_for_demote(subpage, 34528531fc6fSMike Kravetz target_hstate->order); 34538531fc6fSMike Kravetz else 345431731452SDoug Berger prep_compound_page(subpage, target_hstate->order); 345531731452SDoug Berger set_page_private(subpage, 0); 345631731452SDoug Berger prep_new_huge_page(target_hstate, subpage, nid); 34572b21624fSMike Kravetz free_huge_page(subpage); 34588531fc6fSMike Kravetz } 34598531fc6fSMike Kravetz mutex_unlock(&target_hstate->resize_lock); 34608531fc6fSMike Kravetz 34618531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34628531fc6fSMike Kravetz 34638531fc6fSMike Kravetz /* 34648531fc6fSMike Kravetz * Not absolutely necessary, but for consistency update max_huge_pages 34658531fc6fSMike Kravetz * based on pool changes for the demoted page. 34668531fc6fSMike Kravetz */ 34678531fc6fSMike Kravetz h->max_huge_pages--; 3468a43a83c7SMiaohe Lin target_hstate->max_huge_pages += 3469a43a83c7SMiaohe Lin pages_per_huge_page(h) / pages_per_huge_page(target_hstate); 34708531fc6fSMike Kravetz 34718531fc6fSMike Kravetz return rc; 34728531fc6fSMike Kravetz } 34738531fc6fSMike Kravetz 347479dfc695SMike Kravetz static int demote_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed) 347579dfc695SMike Kravetz __must_hold(&hugetlb_lock) 347679dfc695SMike Kravetz { 34778531fc6fSMike Kravetz int nr_nodes, node; 34788531fc6fSMike Kravetz struct page *page; 347979dfc695SMike Kravetz 348079dfc695SMike Kravetz lockdep_assert_held(&hugetlb_lock); 348179dfc695SMike Kravetz 348279dfc695SMike Kravetz /* We should never get here if no demote order */ 348379dfc695SMike Kravetz if (!h->demote_order) { 348479dfc695SMike Kravetz pr_warn("HugeTLB: NULL demote order passed to demote_pool_huge_page.\n"); 348579dfc695SMike Kravetz return -EINVAL; /* internal error */ 348679dfc695SMike Kravetz } 348779dfc695SMike Kravetz 34888531fc6fSMike Kravetz for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 34895a317412SMike Kravetz list_for_each_entry(page, &h->hugepage_freelists[node], lru) { 34905a317412SMike Kravetz if (PageHWPoison(page)) 34915a317412SMike Kravetz continue; 34925a317412SMike Kravetz 34935a317412SMike Kravetz return demote_free_huge_page(h, page); 34948531fc6fSMike Kravetz } 34958531fc6fSMike Kravetz } 34968531fc6fSMike Kravetz 34975a317412SMike Kravetz /* 34985a317412SMike Kravetz * Only way to get here is if all pages on free lists are poisoned. 34995a317412SMike Kravetz * Return -EBUSY so that caller will not retry. 35005a317412SMike Kravetz */ 35015a317412SMike Kravetz return -EBUSY; 350279dfc695SMike Kravetz } 350379dfc695SMike Kravetz 3504a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 3505a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 3506a3437870SNishanth Aravamudan 350779dfc695SMike Kravetz #define HSTATE_ATTR_WO(_name) \ 350879dfc695SMike Kravetz static struct kobj_attribute _name##_attr = __ATTR_WO(_name) 350979dfc695SMike Kravetz 3510a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 351198bc26acSMiaohe Lin static struct kobj_attribute _name##_attr = __ATTR_RW(_name) 3512a3437870SNishanth Aravamudan 3513a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 3514a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 3515a3437870SNishanth Aravamudan 35169a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 35179a305230SLee Schermerhorn 35189a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 3519a3437870SNishanth Aravamudan { 3520a3437870SNishanth Aravamudan int i; 35219a305230SLee Schermerhorn 3522a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 35239a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 35249a305230SLee Schermerhorn if (nidp) 35259a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 3526a3437870SNishanth Aravamudan return &hstates[i]; 35279a305230SLee Schermerhorn } 35289a305230SLee Schermerhorn 35299a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 3530a3437870SNishanth Aravamudan } 3531a3437870SNishanth Aravamudan 353206808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 3533a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3534a3437870SNishanth Aravamudan { 35359a305230SLee Schermerhorn struct hstate *h; 35369a305230SLee Schermerhorn unsigned long nr_huge_pages; 35379a305230SLee Schermerhorn int nid; 35389a305230SLee Schermerhorn 35399a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 35409a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 35419a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 35429a305230SLee Schermerhorn else 35439a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 35449a305230SLee Schermerhorn 3545ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", nr_huge_pages); 3546a3437870SNishanth Aravamudan } 3547adbe8726SEric B Munson 3548238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 3549238d3c13SDavid Rientjes struct hstate *h, int nid, 3550238d3c13SDavid Rientjes unsigned long count, size_t len) 3551a3437870SNishanth Aravamudan { 3552a3437870SNishanth Aravamudan int err; 35532d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 3554a3437870SNishanth Aravamudan 35552d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 35562d0adf7eSOscar Salvador return -EINVAL; 3557adbe8726SEric B Munson 35589a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 35599a305230SLee Schermerhorn /* 35609a305230SLee Schermerhorn * global hstate attribute 35619a305230SLee Schermerhorn */ 35629a305230SLee Schermerhorn if (!(obey_mempolicy && 35632d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 35642d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 35652d0adf7eSOscar Salvador else 35662d0adf7eSOscar Salvador n_mask = &nodes_allowed; 35672d0adf7eSOscar Salvador } else { 35689a305230SLee Schermerhorn /* 3569fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 3570fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 35719a305230SLee Schermerhorn */ 35722d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 35732d0adf7eSOscar Salvador n_mask = &nodes_allowed; 3574fd875dcaSMike Kravetz } 35759a305230SLee Schermerhorn 35762d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 357706808b08SLee Schermerhorn 35784eb0716eSAlexandre Ghiti return err ? err : len; 357906808b08SLee Schermerhorn } 358006808b08SLee Schermerhorn 3581238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 3582238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 3583238d3c13SDavid Rientjes size_t len) 3584238d3c13SDavid Rientjes { 3585238d3c13SDavid Rientjes struct hstate *h; 3586238d3c13SDavid Rientjes unsigned long count; 3587238d3c13SDavid Rientjes int nid; 3588238d3c13SDavid Rientjes int err; 3589238d3c13SDavid Rientjes 3590238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 3591238d3c13SDavid Rientjes if (err) 3592238d3c13SDavid Rientjes return err; 3593238d3c13SDavid Rientjes 3594238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 3595238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 3596238d3c13SDavid Rientjes } 3597238d3c13SDavid Rientjes 359806808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 359906808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 360006808b08SLee Schermerhorn { 360106808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 360206808b08SLee Schermerhorn } 360306808b08SLee Schermerhorn 360406808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 360506808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 360606808b08SLee Schermerhorn { 3607238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 3608a3437870SNishanth Aravamudan } 3609a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 3610a3437870SNishanth Aravamudan 361106808b08SLee Schermerhorn #ifdef CONFIG_NUMA 361206808b08SLee Schermerhorn 361306808b08SLee Schermerhorn /* 361406808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 361506808b08SLee Schermerhorn * huge page alloc/free. 361606808b08SLee Schermerhorn */ 361706808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 3618ae7a927dSJoe Perches struct kobj_attribute *attr, 3619ae7a927dSJoe Perches char *buf) 362006808b08SLee Schermerhorn { 362106808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 362206808b08SLee Schermerhorn } 362306808b08SLee Schermerhorn 362406808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 362506808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 362606808b08SLee Schermerhorn { 3627238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 362806808b08SLee Schermerhorn } 362906808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 363006808b08SLee Schermerhorn #endif 363106808b08SLee Schermerhorn 363206808b08SLee Schermerhorn 3633a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 3634a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3635a3437870SNishanth Aravamudan { 36369a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3637ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages); 3638a3437870SNishanth Aravamudan } 3639adbe8726SEric B Munson 3640a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 3641a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 3642a3437870SNishanth Aravamudan { 3643a3437870SNishanth Aravamudan int err; 3644a3437870SNishanth Aravamudan unsigned long input; 36459a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3646a3437870SNishanth Aravamudan 3647bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3648adbe8726SEric B Munson return -EINVAL; 3649adbe8726SEric B Munson 36503dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 3651a3437870SNishanth Aravamudan if (err) 365273ae31e5SEric B Munson return err; 3653a3437870SNishanth Aravamudan 3654db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3655a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 3656db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3657a3437870SNishanth Aravamudan 3658a3437870SNishanth Aravamudan return count; 3659a3437870SNishanth Aravamudan } 3660a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 3661a3437870SNishanth Aravamudan 3662a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 3663a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3664a3437870SNishanth Aravamudan { 36659a305230SLee Schermerhorn struct hstate *h; 36669a305230SLee Schermerhorn unsigned long free_huge_pages; 36679a305230SLee Schermerhorn int nid; 36689a305230SLee Schermerhorn 36699a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 36709a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 36719a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 36729a305230SLee Schermerhorn else 36739a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 36749a305230SLee Schermerhorn 3675ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", free_huge_pages); 3676a3437870SNishanth Aravamudan } 3677a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 3678a3437870SNishanth Aravamudan 3679a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 3680a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3681a3437870SNishanth Aravamudan { 36829a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3683ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->resv_huge_pages); 3684a3437870SNishanth Aravamudan } 3685a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 3686a3437870SNishanth Aravamudan 3687a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 3688a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3689a3437870SNishanth Aravamudan { 36909a305230SLee Schermerhorn struct hstate *h; 36919a305230SLee Schermerhorn unsigned long surplus_huge_pages; 36929a305230SLee Schermerhorn int nid; 36939a305230SLee Schermerhorn 36949a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 36959a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 36969a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 36979a305230SLee Schermerhorn else 36989a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 36999a305230SLee Schermerhorn 3700ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", surplus_huge_pages); 3701a3437870SNishanth Aravamudan } 3702a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3703a3437870SNishanth Aravamudan 370479dfc695SMike Kravetz static ssize_t demote_store(struct kobject *kobj, 370579dfc695SMike Kravetz struct kobj_attribute *attr, const char *buf, size_t len) 370679dfc695SMike Kravetz { 370779dfc695SMike Kravetz unsigned long nr_demote; 370879dfc695SMike Kravetz unsigned long nr_available; 370979dfc695SMike Kravetz nodemask_t nodes_allowed, *n_mask; 371079dfc695SMike Kravetz struct hstate *h; 37118eeda55fSLi zeming int err; 371279dfc695SMike Kravetz int nid; 371379dfc695SMike Kravetz 371479dfc695SMike Kravetz err = kstrtoul(buf, 10, &nr_demote); 371579dfc695SMike Kravetz if (err) 371679dfc695SMike Kravetz return err; 371779dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 371879dfc695SMike Kravetz 371979dfc695SMike Kravetz if (nid != NUMA_NO_NODE) { 372079dfc695SMike Kravetz init_nodemask_of_node(&nodes_allowed, nid); 372179dfc695SMike Kravetz n_mask = &nodes_allowed; 372279dfc695SMike Kravetz } else { 372379dfc695SMike Kravetz n_mask = &node_states[N_MEMORY]; 372479dfc695SMike Kravetz } 372579dfc695SMike Kravetz 372679dfc695SMike Kravetz /* Synchronize with other sysfs operations modifying huge pages */ 372779dfc695SMike Kravetz mutex_lock(&h->resize_lock); 372879dfc695SMike Kravetz spin_lock_irq(&hugetlb_lock); 372979dfc695SMike Kravetz 373079dfc695SMike Kravetz while (nr_demote) { 373179dfc695SMike Kravetz /* 373279dfc695SMike Kravetz * Check for available pages to demote each time thorough the 373379dfc695SMike Kravetz * loop as demote_pool_huge_page will drop hugetlb_lock. 373479dfc695SMike Kravetz */ 373579dfc695SMike Kravetz if (nid != NUMA_NO_NODE) 373679dfc695SMike Kravetz nr_available = h->free_huge_pages_node[nid]; 373779dfc695SMike Kravetz else 373879dfc695SMike Kravetz nr_available = h->free_huge_pages; 373979dfc695SMike Kravetz nr_available -= h->resv_huge_pages; 374079dfc695SMike Kravetz if (!nr_available) 374179dfc695SMike Kravetz break; 374279dfc695SMike Kravetz 374379dfc695SMike Kravetz err = demote_pool_huge_page(h, n_mask); 374479dfc695SMike Kravetz if (err) 374579dfc695SMike Kravetz break; 374679dfc695SMike Kravetz 374779dfc695SMike Kravetz nr_demote--; 374879dfc695SMike Kravetz } 374979dfc695SMike Kravetz 375079dfc695SMike Kravetz spin_unlock_irq(&hugetlb_lock); 375179dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 375279dfc695SMike Kravetz 375379dfc695SMike Kravetz if (err) 375479dfc695SMike Kravetz return err; 375579dfc695SMike Kravetz return len; 375679dfc695SMike Kravetz } 375779dfc695SMike Kravetz HSTATE_ATTR_WO(demote); 375879dfc695SMike Kravetz 375979dfc695SMike Kravetz static ssize_t demote_size_show(struct kobject *kobj, 376079dfc695SMike Kravetz struct kobj_attribute *attr, char *buf) 376179dfc695SMike Kravetz { 376212658abfSMiaohe Lin struct hstate *h = kobj_to_hstate(kobj, NULL); 376379dfc695SMike Kravetz unsigned long demote_size = (PAGE_SIZE << h->demote_order) / SZ_1K; 376479dfc695SMike Kravetz 376579dfc695SMike Kravetz return sysfs_emit(buf, "%lukB\n", demote_size); 376679dfc695SMike Kravetz } 376779dfc695SMike Kravetz 376879dfc695SMike Kravetz static ssize_t demote_size_store(struct kobject *kobj, 376979dfc695SMike Kravetz struct kobj_attribute *attr, 377079dfc695SMike Kravetz const char *buf, size_t count) 377179dfc695SMike Kravetz { 377279dfc695SMike Kravetz struct hstate *h, *demote_hstate; 377379dfc695SMike Kravetz unsigned long demote_size; 377479dfc695SMike Kravetz unsigned int demote_order; 377579dfc695SMike Kravetz 377679dfc695SMike Kravetz demote_size = (unsigned long)memparse(buf, NULL); 377779dfc695SMike Kravetz 377879dfc695SMike Kravetz demote_hstate = size_to_hstate(demote_size); 377979dfc695SMike Kravetz if (!demote_hstate) 378079dfc695SMike Kravetz return -EINVAL; 378179dfc695SMike Kravetz demote_order = demote_hstate->order; 3782a01f4390SMike Kravetz if (demote_order < HUGETLB_PAGE_ORDER) 3783a01f4390SMike Kravetz return -EINVAL; 378479dfc695SMike Kravetz 378579dfc695SMike Kravetz /* demote order must be smaller than hstate order */ 378612658abfSMiaohe Lin h = kobj_to_hstate(kobj, NULL); 378779dfc695SMike Kravetz if (demote_order >= h->order) 378879dfc695SMike Kravetz return -EINVAL; 378979dfc695SMike Kravetz 379079dfc695SMike Kravetz /* resize_lock synchronizes access to demote size and writes */ 379179dfc695SMike Kravetz mutex_lock(&h->resize_lock); 379279dfc695SMike Kravetz h->demote_order = demote_order; 379379dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 379479dfc695SMike Kravetz 379579dfc695SMike Kravetz return count; 379679dfc695SMike Kravetz } 379779dfc695SMike Kravetz HSTATE_ATTR(demote_size); 379879dfc695SMike Kravetz 3799a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3800a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3801a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3802a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3803a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3804a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 380506808b08SLee Schermerhorn #ifdef CONFIG_NUMA 380606808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 380706808b08SLee Schermerhorn #endif 3808a3437870SNishanth Aravamudan NULL, 3809a3437870SNishanth Aravamudan }; 3810a3437870SNishanth Aravamudan 381167e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3812a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3813a3437870SNishanth Aravamudan }; 3814a3437870SNishanth Aravamudan 381579dfc695SMike Kravetz static struct attribute *hstate_demote_attrs[] = { 381679dfc695SMike Kravetz &demote_size_attr.attr, 381779dfc695SMike Kravetz &demote_attr.attr, 381879dfc695SMike Kravetz NULL, 381979dfc695SMike Kravetz }; 382079dfc695SMike Kravetz 382179dfc695SMike Kravetz static const struct attribute_group hstate_demote_attr_group = { 382279dfc695SMike Kravetz .attrs = hstate_demote_attrs, 382379dfc695SMike Kravetz }; 382479dfc695SMike Kravetz 3825094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 38269a305230SLee Schermerhorn struct kobject **hstate_kobjs, 382767e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 3828a3437870SNishanth Aravamudan { 3829a3437870SNishanth Aravamudan int retval; 3830972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 3831a3437870SNishanth Aravamudan 38329a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 38339a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 3834a3437870SNishanth Aravamudan return -ENOMEM; 3835a3437870SNishanth Aravamudan 38369a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 3837cc2205a6SMiaohe Lin if (retval) { 38389a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 3839cc2205a6SMiaohe Lin hstate_kobjs[hi] = NULL; 38403a6bdda0SMiaohe Lin return retval; 3841cc2205a6SMiaohe Lin } 3842a3437870SNishanth Aravamudan 384379dfc695SMike Kravetz if (h->demote_order) { 384401088a60SMiaohe Lin retval = sysfs_create_group(hstate_kobjs[hi], 384501088a60SMiaohe Lin &hstate_demote_attr_group); 384601088a60SMiaohe Lin if (retval) { 384779dfc695SMike Kravetz pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name); 384801088a60SMiaohe Lin sysfs_remove_group(hstate_kobjs[hi], hstate_attr_group); 384901088a60SMiaohe Lin kobject_put(hstate_kobjs[hi]); 385001088a60SMiaohe Lin hstate_kobjs[hi] = NULL; 385101088a60SMiaohe Lin return retval; 385201088a60SMiaohe Lin } 385379dfc695SMike Kravetz } 385479dfc695SMike Kravetz 385501088a60SMiaohe Lin return 0; 3856a3437870SNishanth Aravamudan } 3857a3437870SNishanth Aravamudan 38589a305230SLee Schermerhorn #ifdef CONFIG_NUMA 3859a4a00b45SMuchun Song static bool hugetlb_sysfs_initialized __ro_after_init; 38609a305230SLee Schermerhorn 38619a305230SLee Schermerhorn /* 38629a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 386310fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 386410fbcf4cSKay Sievers * index of a node device or _hstate == node id. 386510fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 38669a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 38679a305230SLee Schermerhorn */ 38689a305230SLee Schermerhorn struct node_hstate { 38699a305230SLee Schermerhorn struct kobject *hugepages_kobj; 38709a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 38719a305230SLee Schermerhorn }; 3872b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 38739a305230SLee Schermerhorn 38749a305230SLee Schermerhorn /* 387510fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 38769a305230SLee Schermerhorn */ 38779a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 38789a305230SLee Schermerhorn &nr_hugepages_attr.attr, 38799a305230SLee Schermerhorn &free_hugepages_attr.attr, 38809a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 38819a305230SLee Schermerhorn NULL, 38829a305230SLee Schermerhorn }; 38839a305230SLee Schermerhorn 388467e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 38859a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 38869a305230SLee Schermerhorn }; 38879a305230SLee Schermerhorn 38889a305230SLee Schermerhorn /* 388910fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 38909a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 38919a305230SLee Schermerhorn */ 38929a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 38939a305230SLee Schermerhorn { 38949a305230SLee Schermerhorn int nid; 38959a305230SLee Schermerhorn 38969a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 38979a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 38989a305230SLee Schermerhorn int i; 38999a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 39009a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 39019a305230SLee Schermerhorn if (nidp) 39029a305230SLee Schermerhorn *nidp = nid; 39039a305230SLee Schermerhorn return &hstates[i]; 39049a305230SLee Schermerhorn } 39059a305230SLee Schermerhorn } 39069a305230SLee Schermerhorn 39079a305230SLee Schermerhorn BUG(); 39089a305230SLee Schermerhorn return NULL; 39099a305230SLee Schermerhorn } 39109a305230SLee Schermerhorn 39119a305230SLee Schermerhorn /* 391210fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 39139a305230SLee Schermerhorn * No-op if no hstate attributes attached. 39149a305230SLee Schermerhorn */ 3915a4a00b45SMuchun Song void hugetlb_unregister_node(struct node *node) 39169a305230SLee Schermerhorn { 39179a305230SLee Schermerhorn struct hstate *h; 391810fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39199a305230SLee Schermerhorn 39209a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39219b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 39229a305230SLee Schermerhorn 3923972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3924972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 392501088a60SMiaohe Lin struct kobject *hstate_kobj = nhs->hstate_kobjs[idx]; 392601088a60SMiaohe Lin 392701088a60SMiaohe Lin if (!hstate_kobj) 392801088a60SMiaohe Lin continue; 392901088a60SMiaohe Lin if (h->demote_order) 393001088a60SMiaohe Lin sysfs_remove_group(hstate_kobj, &hstate_demote_attr_group); 393101088a60SMiaohe Lin sysfs_remove_group(hstate_kobj, &per_node_hstate_attr_group); 393201088a60SMiaohe Lin kobject_put(hstate_kobj); 3933972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3934972dc4deSAneesh Kumar K.V } 39359a305230SLee Schermerhorn 39369a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 39379a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 39389a305230SLee Schermerhorn } 39399a305230SLee Schermerhorn 39409a305230SLee Schermerhorn 39419a305230SLee Schermerhorn /* 394210fbcf4cSKay Sievers * Register hstate attributes for a single node device. 39439a305230SLee Schermerhorn * No-op if attributes already registered. 39449a305230SLee Schermerhorn */ 3945a4a00b45SMuchun Song void hugetlb_register_node(struct node *node) 39469a305230SLee Schermerhorn { 39479a305230SLee Schermerhorn struct hstate *h; 394810fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39499a305230SLee Schermerhorn int err; 39509a305230SLee Schermerhorn 3951a4a00b45SMuchun Song if (!hugetlb_sysfs_initialized) 3952a4a00b45SMuchun Song return; 3953a4a00b45SMuchun Song 39549a305230SLee Schermerhorn if (nhs->hugepages_kobj) 39559a305230SLee Schermerhorn return; /* already allocated */ 39569a305230SLee Schermerhorn 39579a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 395810fbcf4cSKay Sievers &node->dev.kobj); 39599a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39609a305230SLee Schermerhorn return; 39619a305230SLee Schermerhorn 39629a305230SLee Schermerhorn for_each_hstate(h) { 39639a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 39649a305230SLee Schermerhorn nhs->hstate_kobjs, 39659a305230SLee Schermerhorn &per_node_hstate_attr_group); 39669a305230SLee Schermerhorn if (err) { 3967282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 396810fbcf4cSKay Sievers h->name, node->dev.id); 39699a305230SLee Schermerhorn hugetlb_unregister_node(node); 39709a305230SLee Schermerhorn break; 39719a305230SLee Schermerhorn } 39729a305230SLee Schermerhorn } 39739a305230SLee Schermerhorn } 39749a305230SLee Schermerhorn 39759a305230SLee Schermerhorn /* 39769b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 397710fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 397810fbcf4cSKay Sievers * registered their associated device by this time. 39799a305230SLee Schermerhorn */ 39807d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 39819a305230SLee Schermerhorn { 39829a305230SLee Schermerhorn int nid; 39839a305230SLee Schermerhorn 3984a4a00b45SMuchun Song for_each_online_node(nid) 3985b958d4d0SMuchun Song hugetlb_register_node(node_devices[nid]); 39869a305230SLee Schermerhorn } 39879a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 39889a305230SLee Schermerhorn 39899a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 39909a305230SLee Schermerhorn { 39919a305230SLee Schermerhorn BUG(); 39929a305230SLee Schermerhorn if (nidp) 39939a305230SLee Schermerhorn *nidp = -1; 39949a305230SLee Schermerhorn return NULL; 39959a305230SLee Schermerhorn } 39969a305230SLee Schermerhorn 39979a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 39989a305230SLee Schermerhorn 39999a305230SLee Schermerhorn #endif 40009a305230SLee Schermerhorn 4001263b8998SMiaohe Lin #ifdef CONFIG_CMA 4002263b8998SMiaohe Lin static void __init hugetlb_cma_check(void); 4003263b8998SMiaohe Lin #else 4004263b8998SMiaohe Lin static inline __init void hugetlb_cma_check(void) 4005263b8998SMiaohe Lin { 4006263b8998SMiaohe Lin } 4007263b8998SMiaohe Lin #endif 4008263b8998SMiaohe Lin 4009a4a00b45SMuchun Song static void __init hugetlb_sysfs_init(void) 4010a4a00b45SMuchun Song { 4011a4a00b45SMuchun Song struct hstate *h; 4012a4a00b45SMuchun Song int err; 4013a4a00b45SMuchun Song 4014a4a00b45SMuchun Song hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 4015a4a00b45SMuchun Song if (!hugepages_kobj) 4016a4a00b45SMuchun Song return; 4017a4a00b45SMuchun Song 4018a4a00b45SMuchun Song for_each_hstate(h) { 4019a4a00b45SMuchun Song err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 4020a4a00b45SMuchun Song hstate_kobjs, &hstate_attr_group); 4021a4a00b45SMuchun Song if (err) 4022a4a00b45SMuchun Song pr_err("HugeTLB: Unable to add hstate %s", h->name); 4023a4a00b45SMuchun Song } 4024a4a00b45SMuchun Song 4025a4a00b45SMuchun Song #ifdef CONFIG_NUMA 4026a4a00b45SMuchun Song hugetlb_sysfs_initialized = true; 4027a4a00b45SMuchun Song #endif 4028a4a00b45SMuchun Song hugetlb_register_all_nodes(); 4029a4a00b45SMuchun Song } 4030a4a00b45SMuchun Song 4031a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 4032a3437870SNishanth Aravamudan { 40338382d914SDavidlohr Bueso int i; 40348382d914SDavidlohr Bueso 4035d6995da3SMike Kravetz BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < 4036d6995da3SMike Kravetz __NR_HPAGEFLAGS); 4037d6995da3SMike Kravetz 4038c2833a5bSMike Kravetz if (!hugepages_supported()) { 4039c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 4040c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 40410ef89d25SBenjamin Herrenschmidt return 0; 4042d715cf80SLiam R. Howlett } 4043d715cf80SLiam R. Howlett 4044282f4214SMike Kravetz /* 4045282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 4046282f4214SMike Kravetz * architectures depend on setup being done here. 4047282f4214SMike Kravetz */ 4048a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 4049282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 4050282f4214SMike Kravetz /* 4051282f4214SMike Kravetz * If we did not parse a default huge page size, set 4052282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 4053282f4214SMike Kravetz * number of huge pages for this default size was implicitly 4054282f4214SMike Kravetz * specified, set that here as well. 4055282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 4056282f4214SMike Kravetz * setting. A warning will be printed in this case. 4057282f4214SMike Kravetz */ 4058282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 4059f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 4060282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 4061282f4214SMike Kravetz char buf[32]; 4062282f4214SMike Kravetz 4063282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 4064282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 4065282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 4066282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 4067282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 4068282f4214SMike Kravetz default_hstate_max_huge_pages); 4069282f4214SMike Kravetz } 4070282f4214SMike Kravetz default_hstate.max_huge_pages = 4071282f4214SMike Kravetz default_hstate_max_huge_pages; 4072b5389086SZhenguo Yao 40730a7a0f6fSPeng Liu for_each_online_node(i) 4074b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4075b5389086SZhenguo Yao default_hugepages_in_node[i]; 4076282f4214SMike Kravetz } 4077f8b74815SVaishali Thakkar } 4078a3437870SNishanth Aravamudan 4079cf11e85fSRoman Gushchin hugetlb_cma_check(); 4080a3437870SNishanth Aravamudan hugetlb_init_hstates(); 4081aa888a74SAndi Kleen gather_bootmem_prealloc(); 4082a3437870SNishanth Aravamudan report_hugepages(); 4083a3437870SNishanth Aravamudan 4084a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 40857179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 40869a305230SLee Schermerhorn 40878382d914SDavidlohr Bueso #ifdef CONFIG_SMP 40888382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 40898382d914SDavidlohr Bueso #else 40908382d914SDavidlohr Bueso num_fault_mutexes = 1; 40918382d914SDavidlohr Bueso #endif 4092c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 40936da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 40946da2ec56SKees Cook GFP_KERNEL); 4095c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 40968382d914SDavidlohr Bueso 40978382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 4098c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 4099a3437870SNishanth Aravamudan return 0; 4100a3437870SNishanth Aravamudan } 41013e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 4102a3437870SNishanth Aravamudan 4103ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 4104ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 41059fee021dSVaishali Thakkar { 4106ae94da89SMike Kravetz return size == HPAGE_SIZE; 41079fee021dSVaishali Thakkar } 41089fee021dSVaishali Thakkar 4109d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 4110a3437870SNishanth Aravamudan { 4111a3437870SNishanth Aravamudan struct hstate *h; 41128faa8b07SAndi Kleen unsigned long i; 41138faa8b07SAndi Kleen 4114a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 4115a3437870SNishanth Aravamudan return; 4116a3437870SNishanth Aravamudan } 411747d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 4118a3437870SNishanth Aravamudan BUG_ON(order == 0); 411947d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 412029383967SMike Kravetz mutex_init(&h->resize_lock); 4121a3437870SNishanth Aravamudan h->order = order; 4122aca78307SMiaohe Lin h->mask = ~(huge_page_size(h) - 1); 41238faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 41248faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 41250edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 412654f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 412754f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 4128a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 4129c2c3a60aSMiaohe Lin huge_page_size(h)/SZ_1K); 41308faa8b07SAndi Kleen 4131a3437870SNishanth Aravamudan parsed_hstate = h; 4132a3437870SNishanth Aravamudan } 4133a3437870SNishanth Aravamudan 4134b5389086SZhenguo Yao bool __init __weak hugetlb_node_alloc_supported(void) 4135b5389086SZhenguo Yao { 4136b5389086SZhenguo Yao return true; 4137b5389086SZhenguo Yao } 4138f87442f4SPeng Liu 4139f87442f4SPeng Liu static void __init hugepages_clear_pages_in_node(void) 4140f87442f4SPeng Liu { 4141f87442f4SPeng Liu if (!hugetlb_max_hstate) { 4142f87442f4SPeng Liu default_hstate_max_huge_pages = 0; 4143f87442f4SPeng Liu memset(default_hugepages_in_node, 0, 414410395680SMiaohe Lin sizeof(default_hugepages_in_node)); 4145f87442f4SPeng Liu } else { 4146f87442f4SPeng Liu parsed_hstate->max_huge_pages = 0; 4147f87442f4SPeng Liu memset(parsed_hstate->max_huge_pages_node, 0, 414810395680SMiaohe Lin sizeof(parsed_hstate->max_huge_pages_node)); 4149f87442f4SPeng Liu } 4150f87442f4SPeng Liu } 4151f87442f4SPeng Liu 4152282f4214SMike Kravetz /* 4153282f4214SMike Kravetz * hugepages command line processing 4154282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 4155282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 4156282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 4157282f4214SMike Kravetz * specifies the number of huge pages for the default size. 4158282f4214SMike Kravetz */ 4159282f4214SMike Kravetz static int __init hugepages_setup(char *s) 4160a3437870SNishanth Aravamudan { 4161a3437870SNishanth Aravamudan unsigned long *mhp; 41628faa8b07SAndi Kleen static unsigned long *last_mhp; 4163b5389086SZhenguo Yao int node = NUMA_NO_NODE; 4164b5389086SZhenguo Yao int count; 4165b5389086SZhenguo Yao unsigned long tmp; 4166b5389086SZhenguo Yao char *p = s; 4167a3437870SNishanth Aravamudan 41689fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 4169282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 41709fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 4171f81f6e4bSPeng Liu return 1; 41729fee021dSVaishali Thakkar } 4173282f4214SMike Kravetz 4174a3437870SNishanth Aravamudan /* 4175282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 4176282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 4177282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 4178282f4214SMike Kravetz * default_hugepagesz. 4179a3437870SNishanth Aravamudan */ 41809fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 4181a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 4182a3437870SNishanth Aravamudan else 4183a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 4184a3437870SNishanth Aravamudan 41858faa8b07SAndi Kleen if (mhp == last_mhp) { 4186282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 4187f81f6e4bSPeng Liu return 1; 41888faa8b07SAndi Kleen } 41898faa8b07SAndi Kleen 4190b5389086SZhenguo Yao while (*p) { 4191b5389086SZhenguo Yao count = 0; 4192b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4193b5389086SZhenguo Yao goto invalid; 4194b5389086SZhenguo Yao /* Parameter is node format */ 4195b5389086SZhenguo Yao if (p[count] == ':') { 4196b5389086SZhenguo Yao if (!hugetlb_node_alloc_supported()) { 4197b5389086SZhenguo Yao pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); 4198f81f6e4bSPeng Liu return 1; 4199b5389086SZhenguo Yao } 42000a7a0f6fSPeng Liu if (tmp >= MAX_NUMNODES || !node_online(tmp)) 4201e79ce983SLiu Yuntao goto invalid; 42020a7a0f6fSPeng Liu node = array_index_nospec(tmp, MAX_NUMNODES); 4203b5389086SZhenguo Yao p += count + 1; 4204b5389086SZhenguo Yao /* Parse hugepages */ 4205b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4206b5389086SZhenguo Yao goto invalid; 4207b5389086SZhenguo Yao if (!hugetlb_max_hstate) 4208b5389086SZhenguo Yao default_hugepages_in_node[node] = tmp; 4209b5389086SZhenguo Yao else 4210b5389086SZhenguo Yao parsed_hstate->max_huge_pages_node[node] = tmp; 4211b5389086SZhenguo Yao *mhp += tmp; 4212b5389086SZhenguo Yao /* Go to parse next node*/ 4213b5389086SZhenguo Yao if (p[count] == ',') 4214b5389086SZhenguo Yao p += count + 1; 4215b5389086SZhenguo Yao else 4216b5389086SZhenguo Yao break; 4217b5389086SZhenguo Yao } else { 4218b5389086SZhenguo Yao if (p != s) 4219b5389086SZhenguo Yao goto invalid; 4220b5389086SZhenguo Yao *mhp = tmp; 4221b5389086SZhenguo Yao break; 4222b5389086SZhenguo Yao } 4223b5389086SZhenguo Yao } 4224a3437870SNishanth Aravamudan 42258faa8b07SAndi Kleen /* 42268faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 422704adbc3fSMiaohe Lin * But we need to allocate gigantic hstates here early to still 42288faa8b07SAndi Kleen * use the bootmem allocator. 42298faa8b07SAndi Kleen */ 423004adbc3fSMiaohe Lin if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate)) 42318faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 42328faa8b07SAndi Kleen 42338faa8b07SAndi Kleen last_mhp = mhp; 42348faa8b07SAndi Kleen 4235a3437870SNishanth Aravamudan return 1; 4236b5389086SZhenguo Yao 4237b5389086SZhenguo Yao invalid: 4238b5389086SZhenguo Yao pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p); 4239f87442f4SPeng Liu hugepages_clear_pages_in_node(); 4240f81f6e4bSPeng Liu return 1; 4241a3437870SNishanth Aravamudan } 4242282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 4243e11bfbfcSNick Piggin 4244282f4214SMike Kravetz /* 4245282f4214SMike Kravetz * hugepagesz command line processing 4246282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 4247282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 4248282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 4249282f4214SMike Kravetz * hugepagesz argument was valid. 4250282f4214SMike Kravetz */ 4251359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 4252e11bfbfcSNick Piggin { 4253359f2544SMike Kravetz unsigned long size; 4254282f4214SMike Kravetz struct hstate *h; 4255282f4214SMike Kravetz 4256282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4257359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 4258359f2544SMike Kravetz 4259359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4260282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 4261f81f6e4bSPeng Liu return 1; 4262359f2544SMike Kravetz } 4263359f2544SMike Kravetz 4264282f4214SMike Kravetz h = size_to_hstate(size); 4265282f4214SMike Kravetz if (h) { 4266282f4214SMike Kravetz /* 4267282f4214SMike Kravetz * hstate for this size already exists. This is normally 4268282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 4269282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 4270282f4214SMike Kravetz * the number of huge pages for the default hstate was not 4271282f4214SMike Kravetz * previously specified. 4272282f4214SMike Kravetz */ 4273282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 4274282f4214SMike Kravetz default_hstate.max_huge_pages) { 4275282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 4276f81f6e4bSPeng Liu return 1; 427738237830SMike Kravetz } 427838237830SMike Kravetz 4279282f4214SMike Kravetz /* 4280282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 4281282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 4282282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 4283282f4214SMike Kravetz */ 4284282f4214SMike Kravetz parsed_hstate = h; 4285282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4286e11bfbfcSNick Piggin return 1; 4287e11bfbfcSNick Piggin } 4288282f4214SMike Kravetz 4289359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4290282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4291359f2544SMike Kravetz return 1; 4292359f2544SMike Kravetz } 4293359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 4294359f2544SMike Kravetz 4295282f4214SMike Kravetz /* 4296282f4214SMike Kravetz * default_hugepagesz command line input 4297282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 4298282f4214SMike Kravetz */ 4299ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 4300e11bfbfcSNick Piggin { 4301ae94da89SMike Kravetz unsigned long size; 4302b5389086SZhenguo Yao int i; 4303ae94da89SMike Kravetz 4304282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4305282f4214SMike Kravetz if (parsed_default_hugepagesz) { 4306282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 4307f81f6e4bSPeng Liu return 1; 4308282f4214SMike Kravetz } 4309282f4214SMike Kravetz 4310282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 4311282f4214SMike Kravetz 4312282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4313282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 4314f81f6e4bSPeng Liu return 1; 4315282f4214SMike Kravetz } 4316282f4214SMike Kravetz 4317282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4318282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4319282f4214SMike Kravetz parsed_default_hugepagesz = true; 4320282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 4321282f4214SMike Kravetz 4322282f4214SMike Kravetz /* 4323282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 4324282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 4325282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 4326282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 4327282f4214SMike Kravetz * allocated here from bootmem allocator. 4328282f4214SMike Kravetz */ 4329282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 4330282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 43310a7a0f6fSPeng Liu for_each_online_node(i) 4332b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4333b5389086SZhenguo Yao default_hugepages_in_node[i]; 4334282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 4335282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 4336282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 4337282f4214SMike Kravetz } 4338282f4214SMike Kravetz 4339e11bfbfcSNick Piggin return 1; 4340e11bfbfcSNick Piggin } 4341ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 4342a3437870SNishanth Aravamudan 4343d2226ebdSFeng Tang static nodemask_t *policy_mbind_nodemask(gfp_t gfp) 4344d2226ebdSFeng Tang { 4345d2226ebdSFeng Tang #ifdef CONFIG_NUMA 4346d2226ebdSFeng Tang struct mempolicy *mpol = get_task_policy(current); 4347d2226ebdSFeng Tang 4348d2226ebdSFeng Tang /* 4349d2226ebdSFeng Tang * Only enforce MPOL_BIND policy which overlaps with cpuset policy 4350d2226ebdSFeng Tang * (from policy_nodemask) specifically for hugetlb case 4351d2226ebdSFeng Tang */ 4352d2226ebdSFeng Tang if (mpol->mode == MPOL_BIND && 4353d2226ebdSFeng Tang (apply_policy_zone(mpol, gfp_zone(gfp)) && 4354d2226ebdSFeng Tang cpuset_nodemask_valid_mems_allowed(&mpol->nodes))) 4355d2226ebdSFeng Tang return &mpol->nodes; 4356d2226ebdSFeng Tang #endif 4357d2226ebdSFeng Tang return NULL; 4358d2226ebdSFeng Tang } 4359d2226ebdSFeng Tang 43608ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 43618a213460SNishanth Aravamudan { 43628a213460SNishanth Aravamudan int node; 43638a213460SNishanth Aravamudan unsigned int nr = 0; 4364d2226ebdSFeng Tang nodemask_t *mbind_nodemask; 43658ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 43668ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 43678a213460SNishanth Aravamudan 4368d2226ebdSFeng Tang mbind_nodemask = policy_mbind_nodemask(gfp_mask); 43698ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 4370d2226ebdSFeng Tang if (!mbind_nodemask || node_isset(node, *mbind_nodemask)) 43718a213460SNishanth Aravamudan nr += array[node]; 43728ca39e68SMuchun Song } 43738a213460SNishanth Aravamudan 43748a213460SNishanth Aravamudan return nr; 43758a213460SNishanth Aravamudan } 43768a213460SNishanth Aravamudan 43778a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 437817743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 437917743798SMuchun Song void *buffer, size_t *length, 438017743798SMuchun Song loff_t *ppos, unsigned long *out) 438117743798SMuchun Song { 438217743798SMuchun Song struct ctl_table dup_table; 438317743798SMuchun Song 438417743798SMuchun Song /* 438517743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 438617743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 438717743798SMuchun Song */ 438817743798SMuchun Song dup_table = *table; 438917743798SMuchun Song dup_table.data = out; 439017743798SMuchun Song 439117743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 439217743798SMuchun Song } 439317743798SMuchun Song 439406808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 439506808b08SLee Schermerhorn struct ctl_table *table, int write, 439632927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 43971da177e4SLinus Torvalds { 4398e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 4399238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 440008d4a246SMichal Hocko int ret; 4401e5ff2159SAndi Kleen 4402457c1b27SNishanth Aravamudan if (!hugepages_supported()) 440386613628SJan Stancek return -EOPNOTSUPP; 4404457c1b27SNishanth Aravamudan 440517743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 440617743798SMuchun Song &tmp); 440708d4a246SMichal Hocko if (ret) 440808d4a246SMichal Hocko goto out; 4409e5ff2159SAndi Kleen 4410238d3c13SDavid Rientjes if (write) 4411238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 4412238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 441308d4a246SMichal Hocko out: 441408d4a246SMichal Hocko return ret; 44151da177e4SLinus Torvalds } 4416396faf03SMel Gorman 441706808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 441832927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 441906808b08SLee Schermerhorn { 442006808b08SLee Schermerhorn 442106808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 442206808b08SLee Schermerhorn buffer, length, ppos); 442306808b08SLee Schermerhorn } 442406808b08SLee Schermerhorn 442506808b08SLee Schermerhorn #ifdef CONFIG_NUMA 442606808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 442732927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 442806808b08SLee Schermerhorn { 442906808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 443006808b08SLee Schermerhorn buffer, length, ppos); 443106808b08SLee Schermerhorn } 443206808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 443306808b08SLee Schermerhorn 4434a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 443532927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 4436a3d0c6aaSNishanth Aravamudan { 4437a5516438SAndi Kleen struct hstate *h = &default_hstate; 4438e5ff2159SAndi Kleen unsigned long tmp; 443908d4a246SMichal Hocko int ret; 4440e5ff2159SAndi Kleen 4441457c1b27SNishanth Aravamudan if (!hugepages_supported()) 444286613628SJan Stancek return -EOPNOTSUPP; 4443457c1b27SNishanth Aravamudan 4444e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 4445e5ff2159SAndi Kleen 4446bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 4447adbe8726SEric B Munson return -EINVAL; 4448adbe8726SEric B Munson 444917743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 445017743798SMuchun Song &tmp); 445108d4a246SMichal Hocko if (ret) 445208d4a246SMichal Hocko goto out; 4453e5ff2159SAndi Kleen 4454e5ff2159SAndi Kleen if (write) { 4455db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4456e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 4457db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4458e5ff2159SAndi Kleen } 445908d4a246SMichal Hocko out: 446008d4a246SMichal Hocko return ret; 4461a3d0c6aaSNishanth Aravamudan } 4462a3d0c6aaSNishanth Aravamudan 44631da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 44641da177e4SLinus Torvalds 4465e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 44661da177e4SLinus Torvalds { 4467fcb2b0c5SRoman Gushchin struct hstate *h; 4468fcb2b0c5SRoman Gushchin unsigned long total = 0; 4469fcb2b0c5SRoman Gushchin 4470457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4471457c1b27SNishanth Aravamudan return; 4472fcb2b0c5SRoman Gushchin 4473fcb2b0c5SRoman Gushchin for_each_hstate(h) { 4474fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 4475fcb2b0c5SRoman Gushchin 4476aca78307SMiaohe Lin total += huge_page_size(h) * count; 4477fcb2b0c5SRoman Gushchin 4478fcb2b0c5SRoman Gushchin if (h == &default_hstate) 4479e1759c21SAlexey Dobriyan seq_printf(m, 44801da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 44811da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 4482b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 44837893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 44844f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 4485fcb2b0c5SRoman Gushchin count, 4486a5516438SAndi Kleen h->free_huge_pages, 4487a5516438SAndi Kleen h->resv_huge_pages, 4488a5516438SAndi Kleen h->surplus_huge_pages, 4489aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4490fcb2b0c5SRoman Gushchin } 4491fcb2b0c5SRoman Gushchin 4492aca78307SMiaohe Lin seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K); 44931da177e4SLinus Torvalds } 44941da177e4SLinus Torvalds 44957981593bSJoe Perches int hugetlb_report_node_meminfo(char *buf, int len, int nid) 44961da177e4SLinus Torvalds { 4497a5516438SAndi Kleen struct hstate *h = &default_hstate; 44987981593bSJoe Perches 4499457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4500457c1b27SNishanth Aravamudan return 0; 45017981593bSJoe Perches 45027981593bSJoe Perches return sysfs_emit_at(buf, len, 45031da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 4504a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 4505a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 4506a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 4507a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 4508a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 45091da177e4SLinus Torvalds } 45101da177e4SLinus Torvalds 4511dcadcf1cSGang Li void hugetlb_show_meminfo_node(int nid) 4512949f7ec5SDavid Rientjes { 4513949f7ec5SDavid Rientjes struct hstate *h; 4514949f7ec5SDavid Rientjes 4515457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4516457c1b27SNishanth Aravamudan return; 4517457c1b27SNishanth Aravamudan 4518949f7ec5SDavid Rientjes for_each_hstate(h) 4519dcadcf1cSGang Li printk("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 4520949f7ec5SDavid Rientjes nid, 4521949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 4522949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 4523949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 4524aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4525949f7ec5SDavid Rientjes } 4526949f7ec5SDavid Rientjes 45275d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 45285d317b2bSNaoya Horiguchi { 45295d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 45305d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 45315d317b2bSNaoya Horiguchi } 45325d317b2bSNaoya Horiguchi 45331da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 45341da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 45351da177e4SLinus Torvalds { 4536d0028588SWanpeng Li struct hstate *h; 4537d0028588SWanpeng Li unsigned long nr_total_pages = 0; 4538d0028588SWanpeng Li 4539d0028588SWanpeng Li for_each_hstate(h) 4540d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 4541d0028588SWanpeng Li return nr_total_pages; 45421da177e4SLinus Torvalds } 45431da177e4SLinus Torvalds 4544a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 4545fc1b8a73SMel Gorman { 4546fc1b8a73SMel Gorman int ret = -ENOMEM; 4547fc1b8a73SMel Gorman 45480aa7f354SMiaohe Lin if (!delta) 45490aa7f354SMiaohe Lin return 0; 45500aa7f354SMiaohe Lin 4551db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4552fc1b8a73SMel Gorman /* 4553fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 4554fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 4555fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 4556fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 4557fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 4558fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 4559fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 4560fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 4561fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 4562fc1b8a73SMel Gorman * 4563fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 4564fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 4565fc1b8a73SMel Gorman * we fall back to check against current free page availability as 4566fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 4567fc1b8a73SMel Gorman * semantics that cpuset has. 45688ca39e68SMuchun Song * 45698ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 45708ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 45718ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 45728ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 45738ca39e68SMuchun Song * above. 4574fc1b8a73SMel Gorman */ 4575fc1b8a73SMel Gorman if (delta > 0) { 4576a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 4577fc1b8a73SMel Gorman goto out; 4578fc1b8a73SMel Gorman 45798ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 4580a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 4581fc1b8a73SMel Gorman goto out; 4582fc1b8a73SMel Gorman } 4583fc1b8a73SMel Gorman } 4584fc1b8a73SMel Gorman 4585fc1b8a73SMel Gorman ret = 0; 4586fc1b8a73SMel Gorman if (delta < 0) 4587a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 4588fc1b8a73SMel Gorman 4589fc1b8a73SMel Gorman out: 4590db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4591fc1b8a73SMel Gorman return ret; 4592fc1b8a73SMel Gorman } 4593fc1b8a73SMel Gorman 459484afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 459584afd99bSAndy Whitcroft { 4596f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 459784afd99bSAndy Whitcroft 459884afd99bSAndy Whitcroft /* 459984afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 460084afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 460184afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 460225985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 460384afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 460484afd99bSAndy Whitcroft * new reference here without additional locking. 460584afd99bSAndy Whitcroft */ 460609a26e83SMike Kravetz if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 460709a26e83SMike Kravetz resv_map_dup_hugetlb_cgroup_uncharge_info(resv); 4608f522c3acSJoonsoo Kim kref_get(&resv->refs); 460984afd99bSAndy Whitcroft } 46108d9bfb26SMike Kravetz 46118d9bfb26SMike Kravetz hugetlb_vma_lock_alloc(vma); 461209a26e83SMike Kravetz } 461384afd99bSAndy Whitcroft 4614a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 4615a1e78772SMel Gorman { 4616a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 46178d9bfb26SMike Kravetz struct resv_map *resv; 461890481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 46194e35f483SJoonsoo Kim unsigned long reserve, start, end; 46201c5ecae3SMike Kravetz long gbl_reserve; 462184afd99bSAndy Whitcroft 46228d9bfb26SMike Kravetz hugetlb_vma_lock_free(vma); 46238d9bfb26SMike Kravetz 46248d9bfb26SMike Kravetz resv = vma_resv_map(vma); 46254e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 46264e35f483SJoonsoo Kim return; 46274e35f483SJoonsoo Kim 4628a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 4629a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 463084afd99bSAndy Whitcroft 46314e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 4632e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 46337251ff78SAdam Litke if (reserve) { 46341c5ecae3SMike Kravetz /* 46351c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 46361c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 46371c5ecae3SMike Kravetz */ 46381c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 46391c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 46407251ff78SAdam Litke } 4641e9fe92aeSMina Almasry 4642e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 4643a1e78772SMel Gorman } 4644a1e78772SMel Gorman 464531383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 464631383c68SDan Williams { 464731383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 464831383c68SDan Williams return -EINVAL; 464931383c68SDan Williams return 0; 465031383c68SDan Williams } 465131383c68SDan Williams 465205ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 465305ea8860SDan Williams { 4654aca78307SMiaohe Lin return huge_page_size(hstate_vma(vma)); 465505ea8860SDan Williams } 465605ea8860SDan Williams 46571da177e4SLinus Torvalds /* 46581da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 46591da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 46606c26d310SMiaohe Lin * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get 46611da177e4SLinus Torvalds * this far. 46621da177e4SLinus Torvalds */ 4663b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 46641da177e4SLinus Torvalds { 46651da177e4SLinus Torvalds BUG(); 4666d0217ac0SNick Piggin return 0; 46671da177e4SLinus Torvalds } 46681da177e4SLinus Torvalds 4669eec3636aSJane Chu /* 4670eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 4671eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 4672eec3636aSJane Chu * This is because under System V memory model, mappings created via 4673eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 4674eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 4675eec3636aSJane Chu */ 4676f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 4677d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 467884afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 4679a1e78772SMel Gorman .close = hugetlb_vm_op_close, 4680dd3b614fSDmitry Safonov .may_split = hugetlb_vm_op_split, 468105ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 46821da177e4SLinus Torvalds }; 46831da177e4SLinus Torvalds 46841e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 46851e8f889bSDavid Gibson int writable) 468663551ae0SDavid Gibson { 468763551ae0SDavid Gibson pte_t entry; 468879c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 468963551ae0SDavid Gibson 46901e8f889bSDavid Gibson if (writable) { 4691106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 4692106c992aSGerald Schaefer vma->vm_page_prot))); 469363551ae0SDavid Gibson } else { 4694106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 4695106c992aSGerald Schaefer vma->vm_page_prot)); 469663551ae0SDavid Gibson } 469763551ae0SDavid Gibson entry = pte_mkyoung(entry); 469879c1c594SChristophe Leroy entry = arch_make_huge_pte(entry, shift, vma->vm_flags); 469963551ae0SDavid Gibson 470063551ae0SDavid Gibson return entry; 470163551ae0SDavid Gibson } 470263551ae0SDavid Gibson 47031e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 47041e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 47051e8f889bSDavid Gibson { 47061e8f889bSDavid Gibson pte_t entry; 47071e8f889bSDavid Gibson 4708106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 470932f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 47104b3073e1SRussell King update_mmu_cache(vma, address, ptep); 47111e8f889bSDavid Gibson } 47121e8f889bSDavid Gibson 4713d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 47144a705fefSNaoya Horiguchi { 47154a705fefSNaoya Horiguchi swp_entry_t swp; 47164a705fefSNaoya Horiguchi 47174a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 4718d5ed7444SAneesh Kumar K.V return false; 47194a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4720d79d176aSBaoquan He if (is_migration_entry(swp)) 4721d5ed7444SAneesh Kumar K.V return true; 47224a705fefSNaoya Horiguchi else 4723d5ed7444SAneesh Kumar K.V return false; 47244a705fefSNaoya Horiguchi } 47254a705fefSNaoya Horiguchi 47263e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 47274a705fefSNaoya Horiguchi { 47284a705fefSNaoya Horiguchi swp_entry_t swp; 47294a705fefSNaoya Horiguchi 47304a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 47313e5c3600SBaoquan He return false; 47324a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4733d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 47343e5c3600SBaoquan He return true; 47354a705fefSNaoya Horiguchi else 47363e5c3600SBaoquan He return false; 47374a705fefSNaoya Horiguchi } 47381e8f889bSDavid Gibson 47394eae4efaSPeter Xu static void 47404eae4efaSPeter Xu hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr, 47414eae4efaSPeter Xu struct page *new_page) 47424eae4efaSPeter Xu { 47434eae4efaSPeter Xu __SetPageUptodate(new_page); 47444eae4efaSPeter Xu hugepage_add_new_anon_rmap(new_page, vma, addr); 47451eba86c0SPasha Tatashin set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1)); 47464eae4efaSPeter Xu hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm); 47474eae4efaSPeter Xu ClearHPageRestoreReserve(new_page); 47484eae4efaSPeter Xu SetHPageMigratable(new_page); 47494eae4efaSPeter Xu } 47504eae4efaSPeter Xu 475163551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 4752bc70fbf2SPeter Xu struct vm_area_struct *dst_vma, 4753bc70fbf2SPeter Xu struct vm_area_struct *src_vma) 475463551ae0SDavid Gibson { 47553aa4ed80SMiaohe Lin pte_t *src_pte, *dst_pte, entry; 475663551ae0SDavid Gibson struct page *ptepage; 47571c59827dSHugh Dickins unsigned long addr; 4758bc70fbf2SPeter Xu bool cow = is_cow_mapping(src_vma->vm_flags); 4759bc70fbf2SPeter Xu struct hstate *h = hstate_vma(src_vma); 4760a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 47614eae4efaSPeter Xu unsigned long npages = pages_per_huge_page(h); 4762ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4763e95a9851SMike Kravetz unsigned long last_addr_mask; 4764e8569dd2SAndreas Sandberg int ret = 0; 47651e8f889bSDavid Gibson 4766ac46d4f3SJérôme Glisse if (cow) { 4767bc70fbf2SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, src_vma, src, 4768bc70fbf2SPeter Xu src_vma->vm_start, 4769bc70fbf2SPeter Xu src_vma->vm_end); 4770ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4771623a1ddfSDavid Hildenbrand mmap_assert_write_locked(src); 4772623a1ddfSDavid Hildenbrand raw_write_seqcount_begin(&src->write_protect_seq); 477340549ba8SMike Kravetz } else { 477440549ba8SMike Kravetz /* 477540549ba8SMike Kravetz * For shared mappings the vma lock must be held before 477640549ba8SMike Kravetz * calling huge_pte_offset in the src vma. Otherwise, the 477740549ba8SMike Kravetz * returned ptep could go away if part of a shared pmd and 477840549ba8SMike Kravetz * another thread calls huge_pmd_unshare. 477940549ba8SMike Kravetz */ 478040549ba8SMike Kravetz hugetlb_vma_lock_read(src_vma); 4781ac46d4f3SJérôme Glisse } 4782e8569dd2SAndreas Sandberg 4783e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 4784bc70fbf2SPeter Xu for (addr = src_vma->vm_start; addr < src_vma->vm_end; addr += sz) { 4785cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 47867868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 4787e95a9851SMike Kravetz if (!src_pte) { 4788e95a9851SMike Kravetz addr |= last_addr_mask; 4789c74df32cSHugh Dickins continue; 4790e95a9851SMike Kravetz } 4791bc70fbf2SPeter Xu dst_pte = huge_pte_alloc(dst, dst_vma, addr, sz); 4792e8569dd2SAndreas Sandberg if (!dst_pte) { 4793e8569dd2SAndreas Sandberg ret = -ENOMEM; 4794e8569dd2SAndreas Sandberg break; 4795e8569dd2SAndreas Sandberg } 4796c5c99429SLarry Woodman 47975e41540cSMike Kravetz /* 47985e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 47995e41540cSMike Kravetz * 48003aa4ed80SMiaohe Lin * dst_pte == src_pte is the common case of src/dest sharing. 48015e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 48023aa4ed80SMiaohe Lin * another vma. So page_count of ptep page is checked instead 48033aa4ed80SMiaohe Lin * to reliably determine whether pte is shared. 48045e41540cSMike Kravetz */ 48053aa4ed80SMiaohe Lin if (page_count(virt_to_page(dst_pte)) > 1) { 4806e95a9851SMike Kravetz addr |= last_addr_mask; 4807c5c99429SLarry Woodman continue; 4808e95a9851SMike Kravetz } 4809c5c99429SLarry Woodman 4810cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 4811cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 4812cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 48134a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 48144eae4efaSPeter Xu again: 48153aa4ed80SMiaohe Lin if (huge_pte_none(entry)) { 48165e41540cSMike Kravetz /* 48173aa4ed80SMiaohe Lin * Skip if src entry none. 48185e41540cSMike Kravetz */ 48194a705fefSNaoya Horiguchi ; 4820c2cb0dccSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) { 4821c2cb0dccSNaoya Horiguchi bool uffd_wp = huge_pte_uffd_wp(entry); 4822c2cb0dccSNaoya Horiguchi 4823c2cb0dccSNaoya Horiguchi if (!userfaultfd_wp(dst_vma) && uffd_wp) 4824c2cb0dccSNaoya Horiguchi entry = huge_pte_clear_uffd_wp(entry); 4825c2cb0dccSNaoya Horiguchi set_huge_pte_at(dst, addr, dst_pte, entry); 4826c2cb0dccSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry))) { 48274a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 4828bc70fbf2SPeter Xu bool uffd_wp = huge_pte_uffd_wp(entry); 48294a705fefSNaoya Horiguchi 48306c287605SDavid Hildenbrand if (!is_readable_migration_entry(swp_entry) && cow) { 48314a705fefSNaoya Horiguchi /* 48324a705fefSNaoya Horiguchi * COW mappings require pages in both 48334a705fefSNaoya Horiguchi * parent and child to be set to read. 48344a705fefSNaoya Horiguchi */ 48354dd845b5SAlistair Popple swp_entry = make_readable_migration_entry( 48364dd845b5SAlistair Popple swp_offset(swp_entry)); 48374a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 4838bc70fbf2SPeter Xu if (userfaultfd_wp(src_vma) && uffd_wp) 4839bc70fbf2SPeter Xu entry = huge_pte_mkuffd_wp(entry); 484018f39629SQi Zheng set_huge_pte_at(src, addr, src_pte, entry); 48414a705fefSNaoya Horiguchi } 4842bc70fbf2SPeter Xu if (!userfaultfd_wp(dst_vma) && uffd_wp) 4843bc70fbf2SPeter Xu entry = huge_pte_clear_uffd_wp(entry); 484418f39629SQi Zheng set_huge_pte_at(dst, addr, dst_pte, entry); 4845bc70fbf2SPeter Xu } else if (unlikely(is_pte_marker(entry))) { 4846bc70fbf2SPeter Xu /* 4847bc70fbf2SPeter Xu * We copy the pte marker only if the dst vma has 4848bc70fbf2SPeter Xu * uffd-wp enabled. 4849bc70fbf2SPeter Xu */ 4850bc70fbf2SPeter Xu if (userfaultfd_wp(dst_vma)) 4851bc70fbf2SPeter Xu set_huge_pte_at(dst, addr, dst_pte, entry); 48524a705fefSNaoya Horiguchi } else { 48534eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48544eae4efaSPeter Xu ptepage = pte_page(entry); 48554eae4efaSPeter Xu get_page(ptepage); 48564eae4efaSPeter Xu 48574eae4efaSPeter Xu /* 4858fb3d824dSDavid Hildenbrand * Failing to duplicate the anon rmap is a rare case 4859fb3d824dSDavid Hildenbrand * where we see pinned hugetlb pages while they're 4860fb3d824dSDavid Hildenbrand * prone to COW. We need to do the COW earlier during 4861fb3d824dSDavid Hildenbrand * fork. 48624eae4efaSPeter Xu * 48634eae4efaSPeter Xu * When pre-allocating the page or copying data, we 48644eae4efaSPeter Xu * need to be without the pgtable locks since we could 48654eae4efaSPeter Xu * sleep during the process. 48664eae4efaSPeter Xu */ 4867fb3d824dSDavid Hildenbrand if (!PageAnon(ptepage)) { 4868fb3d824dSDavid Hildenbrand page_dup_file_rmap(ptepage, true); 4869bc70fbf2SPeter Xu } else if (page_try_dup_anon_rmap(ptepage, true, 4870bc70fbf2SPeter Xu src_vma)) { 48714eae4efaSPeter Xu pte_t src_pte_old = entry; 48724eae4efaSPeter Xu struct page *new; 48734eae4efaSPeter Xu 48744eae4efaSPeter Xu spin_unlock(src_ptl); 48754eae4efaSPeter Xu spin_unlock(dst_ptl); 48764eae4efaSPeter Xu /* Do not use reserve as it's private owned */ 4877bc70fbf2SPeter Xu new = alloc_huge_page(dst_vma, addr, 1); 48784eae4efaSPeter Xu if (IS_ERR(new)) { 48794eae4efaSPeter Xu put_page(ptepage); 48804eae4efaSPeter Xu ret = PTR_ERR(new); 48814eae4efaSPeter Xu break; 48824eae4efaSPeter Xu } 4883bc70fbf2SPeter Xu copy_user_huge_page(new, ptepage, addr, dst_vma, 48844eae4efaSPeter Xu npages); 48854eae4efaSPeter Xu put_page(ptepage); 48864eae4efaSPeter Xu 48874eae4efaSPeter Xu /* Install the new huge page if src pte stable */ 48884eae4efaSPeter Xu dst_ptl = huge_pte_lock(h, dst, dst_pte); 48894eae4efaSPeter Xu src_ptl = huge_pte_lockptr(h, src, src_pte); 48904eae4efaSPeter Xu spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 48914eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48924eae4efaSPeter Xu if (!pte_same(src_pte_old, entry)) { 4893bc70fbf2SPeter Xu restore_reserve_on_error(h, dst_vma, addr, 4894846be085SMike Kravetz new); 48954eae4efaSPeter Xu put_page(new); 48963aa4ed80SMiaohe Lin /* huge_ptep of dst_pte won't change as in child */ 48974eae4efaSPeter Xu goto again; 48984eae4efaSPeter Xu } 4899bc70fbf2SPeter Xu hugetlb_install_page(dst_vma, dst_pte, addr, new); 49004eae4efaSPeter Xu spin_unlock(src_ptl); 49014eae4efaSPeter Xu spin_unlock(dst_ptl); 49024eae4efaSPeter Xu continue; 49034eae4efaSPeter Xu } 49044eae4efaSPeter Xu 490534ee645eSJoerg Roedel if (cow) { 49060f10851eSJérôme Glisse /* 49070f10851eSJérôme Glisse * No need to notify as we are downgrading page 49080f10851eSJérôme Glisse * table protection not changing it to point 49090f10851eSJérôme Glisse * to a new page. 49100f10851eSJérôme Glisse * 4911ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 49120f10851eSJérôme Glisse */ 49137f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 491484894e1cSPeter Xu entry = huge_pte_wrprotect(entry); 491534ee645eSJoerg Roedel } 49164eae4efaSPeter Xu 491763551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 49184eae4efaSPeter Xu hugetlb_count_add(npages, dst); 49191c59827dSHugh Dickins } 4920cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 4921cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 492263551ae0SDavid Gibson } 492363551ae0SDavid Gibson 4924623a1ddfSDavid Hildenbrand if (cow) { 4925623a1ddfSDavid Hildenbrand raw_write_seqcount_end(&src->write_protect_seq); 4926ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 492740549ba8SMike Kravetz } else { 492840549ba8SMike Kravetz hugetlb_vma_unlock_read(src_vma); 4929623a1ddfSDavid Hildenbrand } 4930e8569dd2SAndreas Sandberg 4931e8569dd2SAndreas Sandberg return ret; 493263551ae0SDavid Gibson } 493363551ae0SDavid Gibson 4934550a7d60SMina Almasry static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr, 4935db110a99SAneesh Kumar K.V unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte) 4936550a7d60SMina Almasry { 4937550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4938550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4939550a7d60SMina Almasry spinlock_t *src_ptl, *dst_ptl; 4940db110a99SAneesh Kumar K.V pte_t pte; 4941550a7d60SMina Almasry 4942550a7d60SMina Almasry dst_ptl = huge_pte_lock(h, mm, dst_pte); 4943550a7d60SMina Almasry src_ptl = huge_pte_lockptr(h, mm, src_pte); 4944550a7d60SMina Almasry 4945550a7d60SMina Almasry /* 4946550a7d60SMina Almasry * We don't have to worry about the ordering of src and dst ptlocks 4947550a7d60SMina Almasry * because exclusive mmap_sem (or the i_mmap_lock) prevents deadlock. 4948550a7d60SMina Almasry */ 4949550a7d60SMina Almasry if (src_ptl != dst_ptl) 4950550a7d60SMina Almasry spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 4951550a7d60SMina Almasry 4952550a7d60SMina Almasry pte = huge_ptep_get_and_clear(mm, old_addr, src_pte); 4953550a7d60SMina Almasry set_huge_pte_at(mm, new_addr, dst_pte, pte); 4954550a7d60SMina Almasry 4955550a7d60SMina Almasry if (src_ptl != dst_ptl) 4956550a7d60SMina Almasry spin_unlock(src_ptl); 4957550a7d60SMina Almasry spin_unlock(dst_ptl); 4958550a7d60SMina Almasry } 4959550a7d60SMina Almasry 4960550a7d60SMina Almasry int move_hugetlb_page_tables(struct vm_area_struct *vma, 4961550a7d60SMina Almasry struct vm_area_struct *new_vma, 4962550a7d60SMina Almasry unsigned long old_addr, unsigned long new_addr, 4963550a7d60SMina Almasry unsigned long len) 4964550a7d60SMina Almasry { 4965550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4966550a7d60SMina Almasry struct address_space *mapping = vma->vm_file->f_mapping; 4967550a7d60SMina Almasry unsigned long sz = huge_page_size(h); 4968550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4969550a7d60SMina Almasry unsigned long old_end = old_addr + len; 4970e95a9851SMike Kravetz unsigned long last_addr_mask; 4971550a7d60SMina Almasry pte_t *src_pte, *dst_pte; 4972550a7d60SMina Almasry struct mmu_notifier_range range; 49733d0b95cdSBaolin Wang bool shared_pmd = false; 4974550a7d60SMina Almasry 4975550a7d60SMina Almasry mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, old_addr, 4976550a7d60SMina Almasry old_end); 4977550a7d60SMina Almasry adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 49783d0b95cdSBaolin Wang /* 49793d0b95cdSBaolin Wang * In case of shared PMDs, we should cover the maximum possible 49803d0b95cdSBaolin Wang * range. 49813d0b95cdSBaolin Wang */ 49823d0b95cdSBaolin Wang flush_cache_range(vma, range.start, range.end); 49833d0b95cdSBaolin Wang 4984550a7d60SMina Almasry mmu_notifier_invalidate_range_start(&range); 4985e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 4986550a7d60SMina Almasry /* Prevent race with file truncation */ 498740549ba8SMike Kravetz hugetlb_vma_lock_write(vma); 4988550a7d60SMina Almasry i_mmap_lock_write(mapping); 4989550a7d60SMina Almasry for (; old_addr < old_end; old_addr += sz, new_addr += sz) { 4990550a7d60SMina Almasry src_pte = huge_pte_offset(mm, old_addr, sz); 4991e95a9851SMike Kravetz if (!src_pte) { 4992e95a9851SMike Kravetz old_addr |= last_addr_mask; 4993e95a9851SMike Kravetz new_addr |= last_addr_mask; 4994550a7d60SMina Almasry continue; 4995e95a9851SMike Kravetz } 4996550a7d60SMina Almasry if (huge_pte_none(huge_ptep_get(src_pte))) 4997550a7d60SMina Almasry continue; 4998550a7d60SMina Almasry 49994ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) { 50003d0b95cdSBaolin Wang shared_pmd = true; 50014ddb4d91SMike Kravetz old_addr |= last_addr_mask; 50024ddb4d91SMike Kravetz new_addr |= last_addr_mask; 5003550a7d60SMina Almasry continue; 50043d0b95cdSBaolin Wang } 5005550a7d60SMina Almasry 5006550a7d60SMina Almasry dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz); 5007550a7d60SMina Almasry if (!dst_pte) 5008550a7d60SMina Almasry break; 5009550a7d60SMina Almasry 5010db110a99SAneesh Kumar K.V move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte); 5011550a7d60SMina Almasry } 50123d0b95cdSBaolin Wang 50133d0b95cdSBaolin Wang if (shared_pmd) 50143d0b95cdSBaolin Wang flush_tlb_range(vma, range.start, range.end); 50153d0b95cdSBaolin Wang else 5016550a7d60SMina Almasry flush_tlb_range(vma, old_end - len, old_end); 5017550a7d60SMina Almasry mmu_notifier_invalidate_range_end(&range); 501813e4ad2cSNadav Amit i_mmap_unlock_write(mapping); 501940549ba8SMike Kravetz hugetlb_vma_unlock_write(vma); 5020550a7d60SMina Almasry 5021550a7d60SMina Almasry return len + old_addr - old_end; 5022550a7d60SMina Almasry } 5023550a7d60SMina Almasry 502473c54763SPeter Xu static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 502524669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 502605e90bd0SPeter Xu struct page *ref_page, zap_flags_t zap_flags) 502763551ae0SDavid Gibson { 502863551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 502963551ae0SDavid Gibson unsigned long address; 5030c7546f8fSDavid Gibson pte_t *ptep; 503163551ae0SDavid Gibson pte_t pte; 5032cb900f41SKirill A. Shutemov spinlock_t *ptl; 503363551ae0SDavid Gibson struct page *page; 5034a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 5035a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 5036ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 5037e95a9851SMike Kravetz unsigned long last_addr_mask; 5038a4a118f2SNadav Amit bool force_flush = false; 5039a5516438SAndi Kleen 504063551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 5041a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 5042a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 504363551ae0SDavid Gibson 504407e32661SAneesh Kumar K.V /* 504507e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 504607e32661SAneesh Kumar K.V * to huge page. 504707e32661SAneesh Kumar K.V */ 5048ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 504924669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 5050dff11abeSMike Kravetz 5051dff11abeSMike Kravetz /* 5052dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 5053dff11abeSMike Kravetz */ 50546f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 50556f4f13e8SJérôme Glisse end); 5056ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 5057ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5058e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 5059569f48b8SHillf Danton address = start; 5060569f48b8SHillf Danton for (; address < end; address += sz) { 50617868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 5062e95a9851SMike Kravetz if (!ptep) { 5063e95a9851SMike Kravetz address |= last_addr_mask; 5064c7546f8fSDavid Gibson continue; 5065e95a9851SMike Kravetz } 5066c7546f8fSDavid Gibson 5067cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 50684ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, address, ptep)) { 506931d49da5SAneesh Kumar K.V spin_unlock(ptl); 5070a4a118f2SNadav Amit tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); 5071a4a118f2SNadav Amit force_flush = true; 50724ddb4d91SMike Kravetz address |= last_addr_mask; 507331d49da5SAneesh Kumar K.V continue; 507431d49da5SAneesh Kumar K.V } 507539dde65cSChen, Kenneth W 50766629326bSHillf Danton pte = huge_ptep_get(ptep); 507731d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 507831d49da5SAneesh Kumar K.V spin_unlock(ptl); 507931d49da5SAneesh Kumar K.V continue; 508031d49da5SAneesh Kumar K.V } 50816629326bSHillf Danton 50826629326bSHillf Danton /* 50839fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 50849fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 50856629326bSHillf Danton */ 50869fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 508705e90bd0SPeter Xu /* 508805e90bd0SPeter Xu * If the pte was wr-protected by uffd-wp in any of the 508905e90bd0SPeter Xu * swap forms, meanwhile the caller does not want to 509005e90bd0SPeter Xu * drop the uffd-wp bit in this zap, then replace the 509105e90bd0SPeter Xu * pte with a marker. 509205e90bd0SPeter Xu */ 509305e90bd0SPeter Xu if (pte_swp_uffd_wp_any(pte) && 509405e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 509505e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 509605e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 509705e90bd0SPeter Xu else 50989386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 509931d49da5SAneesh Kumar K.V spin_unlock(ptl); 510031d49da5SAneesh Kumar K.V continue; 51018c4894c6SNaoya Horiguchi } 51026629326bSHillf Danton 51036629326bSHillf Danton page = pte_page(pte); 510404f2cbe3SMel Gorman /* 510504f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 510604f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 510704f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 510804f2cbe3SMel Gorman */ 510904f2cbe3SMel Gorman if (ref_page) { 511031d49da5SAneesh Kumar K.V if (page != ref_page) { 511131d49da5SAneesh Kumar K.V spin_unlock(ptl); 511231d49da5SAneesh Kumar K.V continue; 511331d49da5SAneesh Kumar K.V } 511404f2cbe3SMel Gorman /* 511504f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 511604f2cbe3SMel Gorman * future faults in this VMA will fail rather than 511704f2cbe3SMel Gorman * looking like data was lost 511804f2cbe3SMel Gorman */ 511904f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 512004f2cbe3SMel Gorman } 512104f2cbe3SMel Gorman 5122c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 5123b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 5124106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 51256649a386SKen Chen set_page_dirty(page); 512605e90bd0SPeter Xu /* Leave a uffd-wp pte marker if needed */ 512705e90bd0SPeter Xu if (huge_pte_uffd_wp(pte) && 512805e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 512905e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 513005e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 51315d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 5132cea86fe2SHugh Dickins page_remove_rmap(page, vma, true); 513331d49da5SAneesh Kumar K.V 5134cb900f41SKirill A. Shutemov spin_unlock(ptl); 5135e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 513624669e58SAneesh Kumar K.V /* 513731d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 513824669e58SAneesh Kumar K.V */ 513931d49da5SAneesh Kumar K.V if (ref_page) 514031d49da5SAneesh Kumar K.V break; 5141fe1668aeSChen, Kenneth W } 5142ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 514324669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 5144a4a118f2SNadav Amit 5145a4a118f2SNadav Amit /* 5146a4a118f2SNadav Amit * If we unshared PMDs, the TLB flush was not recorded in mmu_gather. We 5147a4a118f2SNadav Amit * could defer the flush until now, since by holding i_mmap_rwsem we 5148a4a118f2SNadav Amit * guaranteed that the last refernece would not be dropped. But we must 5149a4a118f2SNadav Amit * do the flushing before we return, as otherwise i_mmap_rwsem will be 5150a4a118f2SNadav Amit * dropped and the last reference to the shared PMDs page might be 5151a4a118f2SNadav Amit * dropped as well. 5152a4a118f2SNadav Amit * 5153a4a118f2SNadav Amit * In theory we could defer the freeing of the PMD pages as well, but 5154a4a118f2SNadav Amit * huge_pmd_unshare() relies on the exact page_count for the PMD page to 5155a4a118f2SNadav Amit * detect sharing, so we cannot defer the release of the page either. 5156a4a118f2SNadav Amit * Instead, do flush now. 5157a4a118f2SNadav Amit */ 5158a4a118f2SNadav Amit if (force_flush) 5159a4a118f2SNadav Amit tlb_flush_mmu_tlbonly(tlb); 51601da177e4SLinus Torvalds } 516163551ae0SDavid Gibson 5162d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 5163d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 516405e90bd0SPeter Xu unsigned long end, struct page *ref_page, 516505e90bd0SPeter Xu zap_flags_t zap_flags) 5166d833352aSMel Gorman { 516705e90bd0SPeter Xu __unmap_hugepage_range(tlb, vma, start, end, ref_page, zap_flags); 5168d833352aSMel Gorman 5169d833352aSMel Gorman /* 5170d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 5171d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 5172d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 5173d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 5174d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 5175c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 5176d833352aSMel Gorman * because in the context this is called, the VMA is about to be 5177c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 5178d833352aSMel Gorman */ 5179d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 5180d833352aSMel Gorman } 5181d833352aSMel Gorman 5182502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 518305e90bd0SPeter Xu unsigned long end, struct page *ref_page, 518405e90bd0SPeter Xu zap_flags_t zap_flags) 5185502717f4SChen, Kenneth W { 518624669e58SAneesh Kumar K.V struct mmu_gather tlb; 5187dff11abeSMike Kravetz 5188a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 518905e90bd0SPeter Xu __unmap_hugepage_range(&tlb, vma, start, end, ref_page, zap_flags); 5190ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 5191502717f4SChen, Kenneth W } 5192502717f4SChen, Kenneth W 519304f2cbe3SMel Gorman /* 519404f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 5195578b7725SZhiyuan Dai * mapping it owns the reserve page for. The intention is to unmap the page 519604f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 519704f2cbe3SMel Gorman * same region. 519804f2cbe3SMel Gorman */ 51992f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 52002a4b3dedSHarvey Harrison struct page *page, unsigned long address) 520104f2cbe3SMel Gorman { 52027526674dSAdam Litke struct hstate *h = hstate_vma(vma); 520304f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 520404f2cbe3SMel Gorman struct address_space *mapping; 520504f2cbe3SMel Gorman pgoff_t pgoff; 520604f2cbe3SMel Gorman 520704f2cbe3SMel Gorman /* 520804f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 520904f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 521004f2cbe3SMel Gorman */ 52117526674dSAdam Litke address = address & huge_page_mask(h); 521236e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 521336e4f20aSMichal Hocko vma->vm_pgoff; 521493c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 521504f2cbe3SMel Gorman 52164eb2b1dcSMel Gorman /* 52174eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 52184eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 52194eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 52204eb2b1dcSMel Gorman */ 522183cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 52226b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 522304f2cbe3SMel Gorman /* Do not unmap the current VMA */ 522404f2cbe3SMel Gorman if (iter_vma == vma) 522504f2cbe3SMel Gorman continue; 522604f2cbe3SMel Gorman 522704f2cbe3SMel Gorman /* 52282f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 52292f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 52302f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 52312f84a899SMel Gorman */ 52322f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 52332f84a899SMel Gorman continue; 52342f84a899SMel Gorman 52352f84a899SMel Gorman /* 523604f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 523704f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 523804f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 523904f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 524004f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 524104f2cbe3SMel Gorman */ 524204f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 524324669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 524405e90bd0SPeter Xu address + huge_page_size(h), page, 0); 524504f2cbe3SMel Gorman } 524683cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 524704f2cbe3SMel Gorman } 524804f2cbe3SMel Gorman 52490fe6e20bSNaoya Horiguchi /* 5250c89357e2SDavid Hildenbrand * hugetlb_wp() should be called with page lock of the original hugepage held. 5251aa6d2e8cSBaolin Wang * Called with hugetlb_fault_mutex_table held and pte_page locked so we 5252ef009b25SMichal Hocko * cannot race with other handlers or page migration. 5253ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 52540fe6e20bSNaoya Horiguchi */ 5255c89357e2SDavid Hildenbrand static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, 5256c89357e2SDavid Hildenbrand unsigned long address, pte_t *ptep, unsigned int flags, 5257cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 52581e8f889bSDavid Gibson { 5259c89357e2SDavid Hildenbrand const bool unshare = flags & FAULT_FLAG_UNSHARE; 52603999f52eSAneesh Kumar K.V pte_t pte; 5261a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 52621e8f889bSDavid Gibson struct page *old_page, *new_page; 52632b740303SSouptick Joarder int outside_reserve = 0; 52642b740303SSouptick Joarder vm_fault_t ret = 0; 5265974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 5266ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 52671e8f889bSDavid Gibson 5268c89357e2SDavid Hildenbrand VM_BUG_ON(unshare && (flags & FOLL_WRITE)); 5269c89357e2SDavid Hildenbrand VM_BUG_ON(!unshare && !(flags & FOLL_WRITE)); 5270c89357e2SDavid Hildenbrand 52711d8d1464SDavid Hildenbrand /* 52721d8d1464SDavid Hildenbrand * hugetlb does not support FOLL_FORCE-style write faults that keep the 52731d8d1464SDavid Hildenbrand * PTE mapped R/O such as maybe_mkwrite() would do. 52741d8d1464SDavid Hildenbrand */ 52751d8d1464SDavid Hildenbrand if (WARN_ON_ONCE(!unshare && !(vma->vm_flags & VM_WRITE))) 52761d8d1464SDavid Hildenbrand return VM_FAULT_SIGSEGV; 52771d8d1464SDavid Hildenbrand 52781d8d1464SDavid Hildenbrand /* Let's take out MAP_SHARED mappings first. */ 52791d8d1464SDavid Hildenbrand if (vma->vm_flags & VM_MAYSHARE) { 52801d8d1464SDavid Hildenbrand if (unlikely(unshare)) 52811d8d1464SDavid Hildenbrand return 0; 52821d8d1464SDavid Hildenbrand set_huge_ptep_writable(vma, haddr, ptep); 52831d8d1464SDavid Hildenbrand return 0; 52841d8d1464SDavid Hildenbrand } 52851d8d1464SDavid Hildenbrand 52863999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 52871e8f889bSDavid Gibson old_page = pte_page(pte); 52881e8f889bSDavid Gibson 5289662ce1dcSYang Yang delayacct_wpcopy_start(); 5290662ce1dcSYang Yang 529104f2cbe3SMel Gorman retry_avoidcopy: 5292c89357e2SDavid Hildenbrand /* 5293c89357e2SDavid Hildenbrand * If no-one else is actually using this page, we're the exclusive 5294c89357e2SDavid Hildenbrand * owner and can reuse this page. 5295c89357e2SDavid Hildenbrand */ 529637a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 5297c89357e2SDavid Hildenbrand if (!PageAnonExclusive(old_page)) 52985a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 5299c89357e2SDavid Hildenbrand if (likely(!unshare)) 53005b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 5301662ce1dcSYang Yang 5302662ce1dcSYang Yang delayacct_wpcopy_end(); 530383c54070SNick Piggin return 0; 53041e8f889bSDavid Gibson } 53056c287605SDavid Hildenbrand VM_BUG_ON_PAGE(PageAnon(old_page) && PageAnonExclusive(old_page), 53066c287605SDavid Hildenbrand old_page); 53071e8f889bSDavid Gibson 530804f2cbe3SMel Gorman /* 530904f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 531004f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 531104f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 531204f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 531304f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 531404f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 531504f2cbe3SMel Gorman * of the full address range. 531604f2cbe3SMel Gorman */ 53175944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 531804f2cbe3SMel Gorman old_page != pagecache_page) 531904f2cbe3SMel Gorman outside_reserve = 1; 532004f2cbe3SMel Gorman 532109cbfeafSKirill A. Shutemov get_page(old_page); 5322b76c8cfbSLarry Woodman 5323ad4404a2SDavidlohr Bueso /* 5324ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 5325ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 5326ad4404a2SDavidlohr Bueso */ 5327cb900f41SKirill A. Shutemov spin_unlock(ptl); 53285b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 53291e8f889bSDavid Gibson 53302fc39cecSAdam Litke if (IS_ERR(new_page)) { 533104f2cbe3SMel Gorman /* 533204f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 533304f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 533404f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 533504f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 533604f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 533704f2cbe3SMel Gorman */ 533804f2cbe3SMel Gorman if (outside_reserve) { 533940549ba8SMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 534040549ba8SMike Kravetz pgoff_t idx; 534140549ba8SMike Kravetz u32 hash; 534240549ba8SMike Kravetz 534309cbfeafSKirill A. Shutemov put_page(old_page); 534440549ba8SMike Kravetz /* 534540549ba8SMike Kravetz * Drop hugetlb_fault_mutex and vma_lock before 534640549ba8SMike Kravetz * unmapping. unmapping needs to hold vma_lock 534740549ba8SMike Kravetz * in write mode. Dropping vma_lock in read mode 534840549ba8SMike Kravetz * here is OK as COW mappings do not interact with 534940549ba8SMike Kravetz * PMD sharing. 535040549ba8SMike Kravetz * 535140549ba8SMike Kravetz * Reacquire both after unmap operation. 535240549ba8SMike Kravetz */ 535340549ba8SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 535440549ba8SMike Kravetz hash = hugetlb_fault_mutex_hash(mapping, idx); 535540549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 535640549ba8SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 535740549ba8SMike Kravetz 53585b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 535940549ba8SMike Kravetz 536040549ba8SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 536140549ba8SMike Kravetz hugetlb_vma_lock_read(vma); 5362cb900f41SKirill A. Shutemov spin_lock(ptl); 53635b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5364a9af0c5dSNaoya Horiguchi if (likely(ptep && 5365a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 536604f2cbe3SMel Gorman goto retry_avoidcopy; 5367a734bcc8SHillf Danton /* 5368cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 5369cb900f41SKirill A. Shutemov * lock, and our job is done. 5370a734bcc8SHillf Danton */ 5371662ce1dcSYang Yang delayacct_wpcopy_end(); 5372a734bcc8SHillf Danton return 0; 537304f2cbe3SMel Gorman } 537404f2cbe3SMel Gorman 53752b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 5376ad4404a2SDavidlohr Bueso goto out_release_old; 53771e8f889bSDavid Gibson } 53781e8f889bSDavid Gibson 53790fe6e20bSNaoya Horiguchi /* 53800fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 53810fe6e20bSNaoya Horiguchi * anon_vma prepared. 53820fe6e20bSNaoya Horiguchi */ 538344e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 5384ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 5385ad4404a2SDavidlohr Bueso goto out_release_all; 538644e2aa93SDean Nelson } 53870fe6e20bSNaoya Horiguchi 5388974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 538947ad8475SAndrea Arcangeli pages_per_huge_page(h)); 53900ed361deSNick Piggin __SetPageUptodate(new_page); 53911e8f889bSDavid Gibson 53927269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 53936f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 5394ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5395ad4404a2SDavidlohr Bueso 5396b76c8cfbSLarry Woodman /* 5397cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 5398b76c8cfbSLarry Woodman * before the page tables are altered 5399b76c8cfbSLarry Woodman */ 5400cb900f41SKirill A. Shutemov spin_lock(ptl); 54015b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5402a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 5403d6995da3SMike Kravetz ClearHPageRestoreReserve(new_page); 540407443a85SJoonsoo Kim 5405c89357e2SDavid Hildenbrand /* Break COW or unshare */ 54065b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 5407ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 5408cea86fe2SHugh Dickins page_remove_rmap(old_page, vma, true); 54095b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 54101eba86c0SPasha Tatashin set_huge_pte_at(mm, haddr, ptep, 5411c89357e2SDavid Hildenbrand make_huge_pte(vma, new_page, !unshare)); 54128f251a3dSMike Kravetz SetHPageMigratable(new_page); 54131e8f889bSDavid Gibson /* Make the old page be freed below */ 54141e8f889bSDavid Gibson new_page = old_page; 54151e8f889bSDavid Gibson } 5416cb900f41SKirill A. Shutemov spin_unlock(ptl); 5417ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 5418ad4404a2SDavidlohr Bueso out_release_all: 5419c89357e2SDavid Hildenbrand /* 5420c89357e2SDavid Hildenbrand * No restore in case of successful pagetable update (Break COW or 5421c89357e2SDavid Hildenbrand * unshare) 5422c89357e2SDavid Hildenbrand */ 5423c7b1850dSMike Kravetz if (new_page != old_page) 54245b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 542509cbfeafSKirill A. Shutemov put_page(new_page); 5426ad4404a2SDavidlohr Bueso out_release_old: 542709cbfeafSKirill A. Shutemov put_page(old_page); 54288312034fSJoonsoo Kim 5429ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 5430662ce1dcSYang Yang 5431662ce1dcSYang Yang delayacct_wpcopy_end(); 5432ad4404a2SDavidlohr Bueso return ret; 54331e8f889bSDavid Gibson } 54341e8f889bSDavid Gibson 54353ae77f43SHugh Dickins /* 54363ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 54373ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 54383ae77f43SHugh Dickins */ 54393ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 54402a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 54412a15efc9SHugh Dickins { 54422a15efc9SHugh Dickins struct address_space *mapping; 54432a15efc9SHugh Dickins pgoff_t idx; 54442a15efc9SHugh Dickins struct page *page; 54452a15efc9SHugh Dickins 54462a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 54472a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 54482a15efc9SHugh Dickins 54492a15efc9SHugh Dickins page = find_get_page(mapping, idx); 54502a15efc9SHugh Dickins if (page) 54512a15efc9SHugh Dickins put_page(page); 54522a15efc9SHugh Dickins return page != NULL; 54532a15efc9SHugh Dickins } 54542a15efc9SHugh Dickins 54557e1813d4SMike Kravetz int hugetlb_add_to_page_cache(struct page *page, struct address_space *mapping, 5456ab76ad54SMike Kravetz pgoff_t idx) 5457ab76ad54SMike Kravetz { 5458d9ef44deSMatthew Wilcox (Oracle) struct folio *folio = page_folio(page); 5459ab76ad54SMike Kravetz struct inode *inode = mapping->host; 5460ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 5461d9ef44deSMatthew Wilcox (Oracle) int err; 5462ab76ad54SMike Kravetz 5463d9ef44deSMatthew Wilcox (Oracle) __folio_set_locked(folio); 5464d9ef44deSMatthew Wilcox (Oracle) err = __filemap_add_folio(mapping, folio, idx, GFP_KERNEL, NULL); 5465d9ef44deSMatthew Wilcox (Oracle) 5466d9ef44deSMatthew Wilcox (Oracle) if (unlikely(err)) { 5467d9ef44deSMatthew Wilcox (Oracle) __folio_clear_locked(folio); 5468ab76ad54SMike Kravetz return err; 5469d9ef44deSMatthew Wilcox (Oracle) } 5470d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5471ab76ad54SMike Kravetz 547222146c3cSMike Kravetz /* 5473d9ef44deSMatthew Wilcox (Oracle) * mark folio dirty so that it will not be removed from cache/file 547422146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 547522146c3cSMike Kravetz */ 5476d9ef44deSMatthew Wilcox (Oracle) folio_mark_dirty(folio); 547722146c3cSMike Kravetz 5478ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 5479ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 5480ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 5481ab76ad54SMike Kravetz return 0; 5482ab76ad54SMike Kravetz } 5483ab76ad54SMike Kravetz 54847677f7fdSAxel Rasmussen static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma, 54857677f7fdSAxel Rasmussen struct address_space *mapping, 54867677f7fdSAxel Rasmussen pgoff_t idx, 54877677f7fdSAxel Rasmussen unsigned int flags, 54887677f7fdSAxel Rasmussen unsigned long haddr, 5489824ddc60SNadav Amit unsigned long addr, 54907677f7fdSAxel Rasmussen unsigned long reason) 54917677f7fdSAxel Rasmussen { 54927677f7fdSAxel Rasmussen u32 hash; 54937677f7fdSAxel Rasmussen struct vm_fault vmf = { 54947677f7fdSAxel Rasmussen .vma = vma, 54957677f7fdSAxel Rasmussen .address = haddr, 5496824ddc60SNadav Amit .real_address = addr, 54977677f7fdSAxel Rasmussen .flags = flags, 54987677f7fdSAxel Rasmussen 54997677f7fdSAxel Rasmussen /* 55007677f7fdSAxel Rasmussen * Hard to debug if it ends up being 55017677f7fdSAxel Rasmussen * used by a callee that assumes 55027677f7fdSAxel Rasmussen * something about the other 55037677f7fdSAxel Rasmussen * uninitialized fields... same as in 55047677f7fdSAxel Rasmussen * memory.c 55057677f7fdSAxel Rasmussen */ 55067677f7fdSAxel Rasmussen }; 55077677f7fdSAxel Rasmussen 55087677f7fdSAxel Rasmussen /* 5509*958f32ceSLiu Shixin * vma_lock and hugetlb_fault_mutex must be dropped before handling 5510*958f32ceSLiu Shixin * userfault. Also mmap_lock could be dropped due to handling 5511*958f32ceSLiu Shixin * userfault, any vma operation should be careful from here. 55127677f7fdSAxel Rasmussen */ 551340549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 55147677f7fdSAxel Rasmussen hash = hugetlb_fault_mutex_hash(mapping, idx); 55157677f7fdSAxel Rasmussen mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5516*958f32ceSLiu Shixin return handle_userfault(&vmf, reason); 55177677f7fdSAxel Rasmussen } 55187677f7fdSAxel Rasmussen 55192b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 55202b740303SSouptick Joarder struct vm_area_struct *vma, 55218382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 5522c64e912cSPeter Xu unsigned long address, pte_t *ptep, 5523c64e912cSPeter Xu pte_t old_pte, unsigned int flags) 5524ac9b9c66SHugh Dickins { 5525a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 55262b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 5527409eb8c2SHillf Danton int anon_rmap = 0; 55284c887265SAdam Litke unsigned long size; 55294c887265SAdam Litke struct page *page; 55301e8f889bSDavid Gibson pte_t new_pte; 5531cb900f41SKirill A. Shutemov spinlock_t *ptl; 5532285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 5533c7b1850dSMike Kravetz bool new_page, new_pagecache_page = false; 5534*958f32ceSLiu Shixin u32 hash = hugetlb_fault_mutex_hash(mapping, idx); 55354c887265SAdam Litke 553604f2cbe3SMel Gorman /* 553704f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 553804f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 5539c89357e2SDavid Hildenbrand * COW/unsharing. Warn that such a situation has occurred as it may not 5540c89357e2SDavid Hildenbrand * be obvious. 554104f2cbe3SMel Gorman */ 554204f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 5543910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 554404f2cbe3SMel Gorman current->pid); 5545*958f32ceSLiu Shixin goto out; 554604f2cbe3SMel Gorman } 554704f2cbe3SMel Gorman 55484c887265SAdam Litke /* 5549188a3972SMike Kravetz * Use page lock to guard against racing truncation 5550188a3972SMike Kravetz * before we get page_table_lock. 55514c887265SAdam Litke */ 5552c7b1850dSMike Kravetz new_page = false; 555387bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 555487bf91d3SMike Kravetz if (!page) { 5555188a3972SMike Kravetz size = i_size_read(mapping->host) >> huge_page_shift(h); 5556188a3972SMike Kravetz if (idx >= size) 5557188a3972SMike Kravetz goto out; 55587677f7fdSAxel Rasmussen /* Check for page in userfault range */ 5559*958f32ceSLiu Shixin if (userfaultfd_missing(vma)) 5560*958f32ceSLiu Shixin return hugetlb_handle_userfault(vma, mapping, idx, 5561824ddc60SNadav Amit flags, haddr, address, 55627677f7fdSAxel Rasmussen VM_UFFD_MISSING); 55631a1aad8aSMike Kravetz 5564285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 55652fc39cecSAdam Litke if (IS_ERR(page)) { 55664643d67eSMike Kravetz /* 55674643d67eSMike Kravetz * Returning error will result in faulting task being 55684643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 55694643d67eSMike Kravetz * tasks from racing to fault in the same page which 55704643d67eSMike Kravetz * could result in false unable to allocate errors. 55714643d67eSMike Kravetz * Page migration does not take the fault mutex, but 55724643d67eSMike Kravetz * does a clear then write of pte's under page table 55734643d67eSMike Kravetz * lock. Page fault code could race with migration, 55744643d67eSMike Kravetz * notice the clear pte and try to allocate a page 55754643d67eSMike Kravetz * here. Before returning error, get ptl and make 55764643d67eSMike Kravetz * sure there really is no pte entry. 55774643d67eSMike Kravetz */ 55784643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 55794643d67eSMike Kravetz ret = 0; 5580d83e6c8aSMiaohe Lin if (huge_pte_none(huge_ptep_get(ptep))) 55812b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 5582d83e6c8aSMiaohe Lin spin_unlock(ptl); 55836bda666aSChristoph Lameter goto out; 55846bda666aSChristoph Lameter } 558547ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 55860ed361deSNick Piggin __SetPageUptodate(page); 5587cb6acd01SMike Kravetz new_page = true; 5588ac9b9c66SHugh Dickins 5589f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 55907e1813d4SMike Kravetz int err = hugetlb_add_to_page_cache(page, mapping, idx); 55916bda666aSChristoph Lameter if (err) { 55923a5497a2SMiaohe Lin /* 55933a5497a2SMiaohe Lin * err can't be -EEXIST which implies someone 55943a5497a2SMiaohe Lin * else consumed the reservation since hugetlb 55953a5497a2SMiaohe Lin * fault mutex is held when add a hugetlb page 55963a5497a2SMiaohe Lin * to the page cache. So it's safe to call 55973a5497a2SMiaohe Lin * restore_reserve_on_error() here. 55983a5497a2SMiaohe Lin */ 55993a5497a2SMiaohe Lin restore_reserve_on_error(h, vma, haddr, page); 56006bda666aSChristoph Lameter put_page(page); 56016bda666aSChristoph Lameter goto out; 56026bda666aSChristoph Lameter } 5603c7b1850dSMike Kravetz new_pagecache_page = true; 560423be7468SMel Gorman } else { 56056bda666aSChristoph Lameter lock_page(page); 56060fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 56070fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 56080fe6e20bSNaoya Horiguchi goto backout_unlocked; 560923be7468SMel Gorman } 5610409eb8c2SHillf Danton anon_rmap = 1; 56110fe6e20bSNaoya Horiguchi } 56120fe6e20bSNaoya Horiguchi } else { 561357303d80SAndy Whitcroft /* 5614998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 5615998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 5616998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 5617fd6a03edSNaoya Horiguchi */ 5618fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 56190eb98f15SMiaohe Lin ret = VM_FAULT_HWPOISON_LARGE | 5620972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5621fd6a03edSNaoya Horiguchi goto backout_unlocked; 56226bda666aSChristoph Lameter } 56237677f7fdSAxel Rasmussen 56247677f7fdSAxel Rasmussen /* Check for page in userfault range. */ 56257677f7fdSAxel Rasmussen if (userfaultfd_minor(vma)) { 56267677f7fdSAxel Rasmussen unlock_page(page); 56277677f7fdSAxel Rasmussen put_page(page); 5628*958f32ceSLiu Shixin return hugetlb_handle_userfault(vma, mapping, idx, 5629824ddc60SNadav Amit flags, haddr, address, 56307677f7fdSAxel Rasmussen VM_UFFD_MINOR); 56317677f7fdSAxel Rasmussen } 5632998b4382SNaoya Horiguchi } 56331e8f889bSDavid Gibson 563457303d80SAndy Whitcroft /* 563557303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 563657303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 563757303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 563857303d80SAndy Whitcroft * the spinlock. 563957303d80SAndy Whitcroft */ 56405e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 5641285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 56422b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 56432b26736cSAndy Whitcroft goto backout_unlocked; 56442b26736cSAndy Whitcroft } 56455e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5646285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 56475e911373SMike Kravetz } 564857303d80SAndy Whitcroft 56498bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 565083c54070SNick Piggin ret = 0; 5651c64e912cSPeter Xu /* If pte changed from under us, retry */ 5652c64e912cSPeter Xu if (!pte_same(huge_ptep_get(ptep), old_pte)) 56534c887265SAdam Litke goto backout; 56544c887265SAdam Litke 565507443a85SJoonsoo Kim if (anon_rmap) { 5656d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5657285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 5658ac714904SChoi Gi-yong } else 5659fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 56601e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 56611e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 5662c64e912cSPeter Xu /* 5663c64e912cSPeter Xu * If this pte was previously wr-protected, keep it wr-protected even 5664c64e912cSPeter Xu * if populated. 5665c64e912cSPeter Xu */ 5666c64e912cSPeter Xu if (unlikely(pte_marker_uffd_wp(old_pte))) 5667c64e912cSPeter Xu new_pte = huge_pte_wrprotect(huge_pte_mkuffd_wp(new_pte)); 5668285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 56691e8f889bSDavid Gibson 56705d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 5671788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 56721e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 5673c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, page, ptl); 56741e8f889bSDavid Gibson } 56751e8f889bSDavid Gibson 5676cb900f41SKirill A. Shutemov spin_unlock(ptl); 5677cb6acd01SMike Kravetz 5678cb6acd01SMike Kravetz /* 56798f251a3dSMike Kravetz * Only set HPageMigratable in newly allocated pages. Existing pages 56808f251a3dSMike Kravetz * found in the pagecache may not have HPageMigratableset if they have 56818f251a3dSMike Kravetz * been isolated for migration. 5682cb6acd01SMike Kravetz */ 5683cb6acd01SMike Kravetz if (new_page) 56848f251a3dSMike Kravetz SetHPageMigratable(page); 5685cb6acd01SMike Kravetz 56864c887265SAdam Litke unlock_page(page); 56874c887265SAdam Litke out: 5688*958f32ceSLiu Shixin hugetlb_vma_unlock_read(vma); 5689*958f32ceSLiu Shixin mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5690ac9b9c66SHugh Dickins return ret; 56914c887265SAdam Litke 56924c887265SAdam Litke backout: 5693cb900f41SKirill A. Shutemov spin_unlock(ptl); 56942b26736cSAndy Whitcroft backout_unlocked: 5695c7b1850dSMike Kravetz if (new_page && !new_pagecache_page) 5696285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 5697fa27759aSMike Kravetz 5698fa27759aSMike Kravetz unlock_page(page); 56994c887265SAdam Litke put_page(page); 57004c887265SAdam Litke goto out; 5701ac9b9c66SHugh Dickins } 5702ac9b9c66SHugh Dickins 57038382d914SDavidlohr Bueso #ifdef CONFIG_SMP 5704188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 57058382d914SDavidlohr Bueso { 57068382d914SDavidlohr Bueso unsigned long key[2]; 57078382d914SDavidlohr Bueso u32 hash; 57088382d914SDavidlohr Bueso 57098382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 57108382d914SDavidlohr Bueso key[1] = idx; 57118382d914SDavidlohr Bueso 571255254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 57138382d914SDavidlohr Bueso 57148382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 57158382d914SDavidlohr Bueso } 57168382d914SDavidlohr Bueso #else 57178382d914SDavidlohr Bueso /* 57186c26d310SMiaohe Lin * For uniprocessor systems we always use a single mutex, so just 57198382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 57208382d914SDavidlohr Bueso */ 5721188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 57228382d914SDavidlohr Bueso { 57238382d914SDavidlohr Bueso return 0; 57248382d914SDavidlohr Bueso } 57258382d914SDavidlohr Bueso #endif 57268382d914SDavidlohr Bueso 57272b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 5728788c7df4SHugh Dickins unsigned long address, unsigned int flags) 572986e5216fSAdam Litke { 57308382d914SDavidlohr Bueso pte_t *ptep, entry; 5731cb900f41SKirill A. Shutemov spinlock_t *ptl; 57322b740303SSouptick Joarder vm_fault_t ret; 57338382d914SDavidlohr Bueso u32 hash; 57348382d914SDavidlohr Bueso pgoff_t idx; 57350fe6e20bSNaoya Horiguchi struct page *page = NULL; 573657303d80SAndy Whitcroft struct page *pagecache_page = NULL; 5737a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 57388382d914SDavidlohr Bueso struct address_space *mapping; 57390f792cf9SNaoya Horiguchi int need_wait_lock = 0; 5740285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 574186e5216fSAdam Litke 5742285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5743fd6a03edSNaoya Horiguchi if (ptep) { 574440549ba8SMike Kravetz /* 574540549ba8SMike Kravetz * Since we hold no locks, ptep could be stale. That is 574640549ba8SMike Kravetz * OK as we are only making decisions based on content and 574740549ba8SMike Kravetz * not actually modifying content here. 574840549ba8SMike Kravetz */ 5749fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 5750290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 5751ad1ac596SMiaohe Lin migration_entry_wait_huge(vma, ptep); 5752290408d4SNaoya Horiguchi return 0; 5753290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 5754aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 5755972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5756c0d0381aSMike Kravetz } 5757ddeaab32SMike Kravetz 57583935baa9SDavid Gibson /* 57593935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 57603935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 57613935baa9SDavid Gibson * the same page in the page cache. 57623935baa9SDavid Gibson */ 576340549ba8SMike Kravetz mapping = vma->vm_file->f_mapping; 576440549ba8SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 5765188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 5766c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 57678382d914SDavidlohr Bueso 576840549ba8SMike Kravetz /* 576940549ba8SMike Kravetz * Acquire vma lock before calling huge_pte_alloc and hold 577040549ba8SMike Kravetz * until finished with ptep. This prevents huge_pmd_unshare from 577140549ba8SMike Kravetz * being called elsewhere and making the ptep no longer valid. 577240549ba8SMike Kravetz * 577340549ba8SMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 577440549ba8SMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 577540549ba8SMike Kravetz * something has changed. 577640549ba8SMike Kravetz */ 577740549ba8SMike Kravetz hugetlb_vma_lock_read(vma); 577840549ba8SMike Kravetz ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h)); 577940549ba8SMike Kravetz if (!ptep) { 578040549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 578140549ba8SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 578240549ba8SMike Kravetz return VM_FAULT_OOM; 578340549ba8SMike Kravetz } 578440549ba8SMike Kravetz 57857f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 5786c64e912cSPeter Xu /* PTE markers should be handled the same way as none pte */ 5787*958f32ceSLiu Shixin if (huge_pte_none_mostly(entry)) 5788*958f32ceSLiu Shixin /* 5789*958f32ceSLiu Shixin * hugetlb_no_page will drop vma lock and hugetlb fault 5790*958f32ceSLiu Shixin * mutex internally, which make us return immediately. 5791*958f32ceSLiu Shixin */ 5792*958f32ceSLiu Shixin return hugetlb_no_page(mm, vma, mapping, idx, address, ptep, 5793c64e912cSPeter Xu entry, flags); 579486e5216fSAdam Litke 579583c54070SNick Piggin ret = 0; 57961e8f889bSDavid Gibson 579757303d80SAndy Whitcroft /* 57980f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 57990f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 58007c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 58017c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 58027c8de358SEthon Paul * properly handle it. 58030f792cf9SNaoya Horiguchi */ 58040f792cf9SNaoya Horiguchi if (!pte_present(entry)) 58050f792cf9SNaoya Horiguchi goto out_mutex; 58060f792cf9SNaoya Horiguchi 58070f792cf9SNaoya Horiguchi /* 5808c89357e2SDavid Hildenbrand * If we are going to COW/unshare the mapping later, we examine the 5809c89357e2SDavid Hildenbrand * pending reservations for this page now. This will ensure that any 581057303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 58111d8d1464SDavid Hildenbrand * spinlock. Also lookup the pagecache page now as it is used to 58121d8d1464SDavid Hildenbrand * determine if a reservation has been consumed. 581357303d80SAndy Whitcroft */ 5814c89357e2SDavid Hildenbrand if ((flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) && 58151d8d1464SDavid Hildenbrand !(vma->vm_flags & VM_MAYSHARE) && !huge_pte_write(entry)) { 5816285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 58172b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 5818b4d1d99fSDavid Gibson goto out_mutex; 58192b26736cSAndy Whitcroft } 58205e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5821285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 582257303d80SAndy Whitcroft 582329be8426SMiaohe Lin pagecache_page = find_lock_page(mapping, idx); 582457303d80SAndy Whitcroft } 582557303d80SAndy Whitcroft 58260f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 58270fe6e20bSNaoya Horiguchi 5828c89357e2SDavid Hildenbrand /* Check for a racing update before calling hugetlb_wp() */ 5829b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 5830cb900f41SKirill A. Shutemov goto out_ptl; 5831b4d1d99fSDavid Gibson 5832166f3eccSPeter Xu /* Handle userfault-wp first, before trying to lock more pages */ 5833166f3eccSPeter Xu if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) && 5834166f3eccSPeter Xu (flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 5835166f3eccSPeter Xu struct vm_fault vmf = { 5836166f3eccSPeter Xu .vma = vma, 5837166f3eccSPeter Xu .address = haddr, 5838166f3eccSPeter Xu .real_address = address, 5839166f3eccSPeter Xu .flags = flags, 5840166f3eccSPeter Xu }; 5841166f3eccSPeter Xu 5842166f3eccSPeter Xu spin_unlock(ptl); 5843166f3eccSPeter Xu if (pagecache_page) { 5844166f3eccSPeter Xu unlock_page(pagecache_page); 5845166f3eccSPeter Xu put_page(pagecache_page); 5846166f3eccSPeter Xu } 584740549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 5848166f3eccSPeter Xu mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5849166f3eccSPeter Xu return handle_userfault(&vmf, VM_UFFD_WP); 5850166f3eccSPeter Xu } 5851166f3eccSPeter Xu 58520f792cf9SNaoya Horiguchi /* 5853c89357e2SDavid Hildenbrand * hugetlb_wp() requires page locks of pte_page(entry) and 58540f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 58550f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 58560f792cf9SNaoya Horiguchi */ 58570f792cf9SNaoya Horiguchi page = pte_page(entry); 58580f792cf9SNaoya Horiguchi if (page != pagecache_page) 58590f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 58600f792cf9SNaoya Horiguchi need_wait_lock = 1; 58610f792cf9SNaoya Horiguchi goto out_ptl; 58620f792cf9SNaoya Horiguchi } 58630f792cf9SNaoya Horiguchi 58640f792cf9SNaoya Horiguchi get_page(page); 5865b4d1d99fSDavid Gibson 5866c89357e2SDavid Hildenbrand if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) { 5867106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 5868c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, 5869cb900f41SKirill A. Shutemov pagecache_page, ptl); 58700f792cf9SNaoya Horiguchi goto out_put_page; 5871c89357e2SDavid Hildenbrand } else if (likely(flags & FAULT_FLAG_WRITE)) { 5872106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 5873b4d1d99fSDavid Gibson } 5874c89357e2SDavid Hildenbrand } 5875b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 5876285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 5877788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 5878285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 58790f792cf9SNaoya Horiguchi out_put_page: 58800f792cf9SNaoya Horiguchi if (page != pagecache_page) 58810f792cf9SNaoya Horiguchi unlock_page(page); 58820f792cf9SNaoya Horiguchi put_page(page); 5883cb900f41SKirill A. Shutemov out_ptl: 5884cb900f41SKirill A. Shutemov spin_unlock(ptl); 588557303d80SAndy Whitcroft 588657303d80SAndy Whitcroft if (pagecache_page) { 588757303d80SAndy Whitcroft unlock_page(pagecache_page); 588857303d80SAndy Whitcroft put_page(pagecache_page); 588957303d80SAndy Whitcroft } 5890b4d1d99fSDavid Gibson out_mutex: 589140549ba8SMike Kravetz hugetlb_vma_unlock_read(vma); 5892c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 58930f792cf9SNaoya Horiguchi /* 58940f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 58950f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 58960f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 58970f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 58980f792cf9SNaoya Horiguchi * here without taking refcount. 58990f792cf9SNaoya Horiguchi */ 59000f792cf9SNaoya Horiguchi if (need_wait_lock) 59010f792cf9SNaoya Horiguchi wait_on_page_locked(page); 59021e8f889bSDavid Gibson return ret; 590386e5216fSAdam Litke } 590486e5216fSAdam Litke 5905714c1891SAxel Rasmussen #ifdef CONFIG_USERFAULTFD 59068fb5debcSMike Kravetz /* 59078fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 59088fb5debcSMike Kravetz * modifications for huge pages. 59098fb5debcSMike Kravetz */ 59108fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 59118fb5debcSMike Kravetz pte_t *dst_pte, 59128fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 59138fb5debcSMike Kravetz unsigned long dst_addr, 59148fb5debcSMike Kravetz unsigned long src_addr, 5915f6191471SAxel Rasmussen enum mcopy_atomic_mode mode, 59166041c691SPeter Xu struct page **pagep, 59176041c691SPeter Xu bool wp_copy) 59188fb5debcSMike Kravetz { 5919f6191471SAxel Rasmussen bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE); 59208cc5fcbbSMina Almasry struct hstate *h = hstate_vma(dst_vma); 59218cc5fcbbSMina Almasry struct address_space *mapping = dst_vma->vm_file->f_mapping; 59228cc5fcbbSMina Almasry pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr); 59231e392147SAndrea Arcangeli unsigned long size; 59241c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 59258fb5debcSMike Kravetz pte_t _dst_pte; 59268fb5debcSMike Kravetz spinlock_t *ptl; 59278cc5fcbbSMina Almasry int ret = -ENOMEM; 59288fb5debcSMike Kravetz struct page *page; 5929f6191471SAxel Rasmussen int writable; 5930cc30042dSMina Almasry bool page_in_pagecache = false; 59318fb5debcSMike Kravetz 5932f6191471SAxel Rasmussen if (is_continue) { 5933f6191471SAxel Rasmussen ret = -EFAULT; 5934f6191471SAxel Rasmussen page = find_lock_page(mapping, idx); 5935f6191471SAxel Rasmussen if (!page) 5936f6191471SAxel Rasmussen goto out; 5937cc30042dSMina Almasry page_in_pagecache = true; 5938f6191471SAxel Rasmussen } else if (!*pagep) { 5939d84cf06eSMina Almasry /* If a page already exists, then it's UFFDIO_COPY for 5940d84cf06eSMina Almasry * a non-missing case. Return -EEXIST. 5941d84cf06eSMina Almasry */ 5942d84cf06eSMina Almasry if (vm_shared && 5943d84cf06eSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 5944d84cf06eSMina Almasry ret = -EEXIST; 59458fb5debcSMike Kravetz goto out; 5946d84cf06eSMina Almasry } 5947d84cf06eSMina Almasry 5948d84cf06eSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 5949d84cf06eSMina Almasry if (IS_ERR(page)) { 5950d84cf06eSMina Almasry ret = -ENOMEM; 5951d84cf06eSMina Almasry goto out; 5952d84cf06eSMina Almasry } 59538fb5debcSMike Kravetz 59548fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 59558fb5debcSMike Kravetz (const void __user *) src_addr, 5956810a56b9SMike Kravetz pages_per_huge_page(h), false); 59578fb5debcSMike Kravetz 5958c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 59598fb5debcSMike Kravetz if (unlikely(ret)) { 59609e368259SAndrea Arcangeli ret = -ENOENT; 59618cc5fcbbSMina Almasry /* Free the allocated page which may have 59628cc5fcbbSMina Almasry * consumed a reservation. 59638cc5fcbbSMina Almasry */ 59648cc5fcbbSMina Almasry restore_reserve_on_error(h, dst_vma, dst_addr, page); 59658cc5fcbbSMina Almasry put_page(page); 59668cc5fcbbSMina Almasry 59678cc5fcbbSMina Almasry /* Allocate a temporary page to hold the copied 59688cc5fcbbSMina Almasry * contents. 59698cc5fcbbSMina Almasry */ 59708cc5fcbbSMina Almasry page = alloc_huge_page_vma(h, dst_vma, dst_addr); 59718cc5fcbbSMina Almasry if (!page) { 59728cc5fcbbSMina Almasry ret = -ENOMEM; 59738cc5fcbbSMina Almasry goto out; 59748cc5fcbbSMina Almasry } 59758fb5debcSMike Kravetz *pagep = page; 59768cc5fcbbSMina Almasry /* Set the outparam pagep and return to the caller to 59778cc5fcbbSMina Almasry * copy the contents outside the lock. Don't free the 59788cc5fcbbSMina Almasry * page. 59798cc5fcbbSMina Almasry */ 59808fb5debcSMike Kravetz goto out; 59818fb5debcSMike Kravetz } 59828fb5debcSMike Kravetz } else { 59838cc5fcbbSMina Almasry if (vm_shared && 59848cc5fcbbSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 59858cc5fcbbSMina Almasry put_page(*pagep); 59868cc5fcbbSMina Almasry ret = -EEXIST; 59878cc5fcbbSMina Almasry *pagep = NULL; 59888cc5fcbbSMina Almasry goto out; 59898cc5fcbbSMina Almasry } 59908cc5fcbbSMina Almasry 59918cc5fcbbSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 59928cc5fcbbSMina Almasry if (IS_ERR(page)) { 5993da9a298fSMiaohe Lin put_page(*pagep); 59948cc5fcbbSMina Almasry ret = -ENOMEM; 59958cc5fcbbSMina Almasry *pagep = NULL; 59968cc5fcbbSMina Almasry goto out; 59978cc5fcbbSMina Almasry } 599834892366SMuchun Song copy_user_huge_page(page, *pagep, dst_addr, dst_vma, 599934892366SMuchun Song pages_per_huge_page(h)); 60008cc5fcbbSMina Almasry put_page(*pagep); 60018fb5debcSMike Kravetz *pagep = NULL; 60028fb5debcSMike Kravetz } 60038fb5debcSMike Kravetz 60048fb5debcSMike Kravetz /* 60058fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 60068fb5debcSMike Kravetz * preceding stores to the page contents become visible before 60078fb5debcSMike Kravetz * the set_pte_at() write. 60088fb5debcSMike Kravetz */ 60098fb5debcSMike Kravetz __SetPageUptodate(page); 60108fb5debcSMike Kravetz 6011f6191471SAxel Rasmussen /* Add shared, newly allocated pages to the page cache. */ 6012f6191471SAxel Rasmussen if (vm_shared && !is_continue) { 60131e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 60141e392147SAndrea Arcangeli ret = -EFAULT; 60151e392147SAndrea Arcangeli if (idx >= size) 60161e392147SAndrea Arcangeli goto out_release_nounlock; 60171c9e8defSMike Kravetz 60181e392147SAndrea Arcangeli /* 60191e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 60207e1813d4SMike Kravetz * hugetlb_add_to_page_cache() below happens through the 60211e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 60221e392147SAndrea Arcangeli * the caller. 60231e392147SAndrea Arcangeli */ 60247e1813d4SMike Kravetz ret = hugetlb_add_to_page_cache(page, mapping, idx); 60251c9e8defSMike Kravetz if (ret) 60261c9e8defSMike Kravetz goto out_release_nounlock; 6027cc30042dSMina Almasry page_in_pagecache = true; 60281c9e8defSMike Kravetz } 60291c9e8defSMike Kravetz 6030bcc66543SMiaohe Lin ptl = huge_pte_lock(h, dst_mm, dst_pte); 60318fb5debcSMike Kravetz 60321e392147SAndrea Arcangeli /* 60336041c691SPeter Xu * We allow to overwrite a pte marker: consider when both MISSING|WP 60346041c691SPeter Xu * registered, we firstly wr-protect a none pte which has no page cache 60356041c691SPeter Xu * page backing it, then access the page. 60366041c691SPeter Xu */ 6037fa27759aSMike Kravetz ret = -EEXIST; 60386041c691SPeter Xu if (!huge_pte_none_mostly(huge_ptep_get(dst_pte))) 60398fb5debcSMike Kravetz goto out_release_unlock; 60408fb5debcSMike Kravetz 6041ab74ef70SMiaohe Lin if (page_in_pagecache) { 6042fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 60431c9e8defSMike Kravetz } else { 6044d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 60458fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 60461c9e8defSMike Kravetz } 60478fb5debcSMike Kravetz 60486041c691SPeter Xu /* 60496041c691SPeter Xu * For either: (1) CONTINUE on a non-shared VMA, or (2) UFFDIO_COPY 60506041c691SPeter Xu * with wp flag set, don't set pte write bit. 60516041c691SPeter Xu */ 60526041c691SPeter Xu if (wp_copy || (is_continue && !vm_shared)) 6053f6191471SAxel Rasmussen writable = 0; 6054f6191471SAxel Rasmussen else 6055f6191471SAxel Rasmussen writable = dst_vma->vm_flags & VM_WRITE; 6056f6191471SAxel Rasmussen 6057f6191471SAxel Rasmussen _dst_pte = make_huge_pte(dst_vma, page, writable); 60586041c691SPeter Xu /* 60596041c691SPeter Xu * Always mark UFFDIO_COPY page dirty; note that this may not be 60606041c691SPeter Xu * extremely important for hugetlbfs for now since swapping is not 60616041c691SPeter Xu * supported, but we should still be clear in that this page cannot be 60626041c691SPeter Xu * thrown away at will, even if write bit not set. 60636041c691SPeter Xu */ 60648fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 60658fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 60668fb5debcSMike Kravetz 60676041c691SPeter Xu if (wp_copy) 60686041c691SPeter Xu _dst_pte = huge_pte_mkuffd_wp(_dst_pte); 60696041c691SPeter Xu 60708fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 60718fb5debcSMike Kravetz 60728fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 60738fb5debcSMike Kravetz 60748fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 60758fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 60768fb5debcSMike Kravetz 60778fb5debcSMike Kravetz spin_unlock(ptl); 6078f6191471SAxel Rasmussen if (!is_continue) 60798f251a3dSMike Kravetz SetHPageMigratable(page); 6080f6191471SAxel Rasmussen if (vm_shared || is_continue) 60811c9e8defSMike Kravetz unlock_page(page); 60828fb5debcSMike Kravetz ret = 0; 60838fb5debcSMike Kravetz out: 60848fb5debcSMike Kravetz return ret; 60858fb5debcSMike Kravetz out_release_unlock: 60868fb5debcSMike Kravetz spin_unlock(ptl); 6087f6191471SAxel Rasmussen if (vm_shared || is_continue) 60881c9e8defSMike Kravetz unlock_page(page); 60895af10dfdSAndrea Arcangeli out_release_nounlock: 6090cc30042dSMina Almasry if (!page_in_pagecache) 6091846be085SMike Kravetz restore_reserve_on_error(h, dst_vma, dst_addr, page); 60928fb5debcSMike Kravetz put_page(page); 60938fb5debcSMike Kravetz goto out; 60948fb5debcSMike Kravetz } 6095714c1891SAxel Rasmussen #endif /* CONFIG_USERFAULTFD */ 60968fb5debcSMike Kravetz 609782e5d378SJoao Martins static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, 609882e5d378SJoao Martins int refs, struct page **pages, 609982e5d378SJoao Martins struct vm_area_struct **vmas) 610082e5d378SJoao Martins { 610182e5d378SJoao Martins int nr; 610282e5d378SJoao Martins 610382e5d378SJoao Martins for (nr = 0; nr < refs; nr++) { 610482e5d378SJoao Martins if (likely(pages)) 610514455eabSCheng Li pages[nr] = nth_page(page, nr); 610682e5d378SJoao Martins if (vmas) 610782e5d378SJoao Martins vmas[nr] = vma; 610882e5d378SJoao Martins } 610982e5d378SJoao Martins } 611082e5d378SJoao Martins 6111a7f22660SDavid Hildenbrand static inline bool __follow_hugetlb_must_fault(unsigned int flags, pte_t *pte, 6112a7f22660SDavid Hildenbrand bool *unshare) 6113a7f22660SDavid Hildenbrand { 6114a7f22660SDavid Hildenbrand pte_t pteval = huge_ptep_get(pte); 6115a7f22660SDavid Hildenbrand 6116a7f22660SDavid Hildenbrand *unshare = false; 6117a7f22660SDavid Hildenbrand if (is_swap_pte(pteval)) 6118a7f22660SDavid Hildenbrand return true; 6119a7f22660SDavid Hildenbrand if (huge_pte_write(pteval)) 6120a7f22660SDavid Hildenbrand return false; 6121a7f22660SDavid Hildenbrand if (flags & FOLL_WRITE) 6122a7f22660SDavid Hildenbrand return true; 6123a7f22660SDavid Hildenbrand if (gup_must_unshare(flags, pte_page(pteval))) { 6124a7f22660SDavid Hildenbrand *unshare = true; 6125a7f22660SDavid Hildenbrand return true; 6126a7f22660SDavid Hildenbrand } 6127a7f22660SDavid Hildenbrand return false; 6128a7f22660SDavid Hildenbrand } 6129a7f22660SDavid Hildenbrand 613028a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 613163551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 613228a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 61334f6da934SPeter Xu long i, unsigned int flags, int *locked) 613463551ae0SDavid Gibson { 6135d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 6136d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 613728a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 6138a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 61390fa5bc40SJoao Martins int err = -EFAULT, refs; 614063551ae0SDavid Gibson 614163551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 614263551ae0SDavid Gibson pte_t *pte; 6143cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 6144a7f22660SDavid Hildenbrand bool unshare = false; 61452a15efc9SHugh Dickins int absent; 614663551ae0SDavid Gibson struct page *page; 614763551ae0SDavid Gibson 61484c887265SAdam Litke /* 614902057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 615002057967SDavid Rientjes * potentially allocating memory. 615102057967SDavid Rientjes */ 6152fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 615302057967SDavid Rientjes remainder = 0; 615402057967SDavid Rientjes break; 615502057967SDavid Rientjes } 615602057967SDavid Rientjes 615702057967SDavid Rientjes /* 61584c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 61592a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 61604c887265SAdam Litke * first, for the page indexing below to work. 6161cb900f41SKirill A. Shutemov * 6162cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 61634c887265SAdam Litke */ 61647868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 61657868a208SPunit Agrawal huge_page_size(h)); 6166cb900f41SKirill A. Shutemov if (pte) 6167cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 61682a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 616963551ae0SDavid Gibson 61702a15efc9SHugh Dickins /* 61712a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 61723ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 61733ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 61743ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 61753ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 61762a15efc9SHugh Dickins */ 61773ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 61783ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 6179cb900f41SKirill A. Shutemov if (pte) 6180cb900f41SKirill A. Shutemov spin_unlock(ptl); 61812a15efc9SHugh Dickins remainder = 0; 61822a15efc9SHugh Dickins break; 61832a15efc9SHugh Dickins } 61842a15efc9SHugh Dickins 61859cc3a5bdSNaoya Horiguchi /* 61869cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 61879cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 61889cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 61899cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 61909cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 61919cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 61929cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 61939cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 61949cc3a5bdSNaoya Horiguchi */ 6195a7f22660SDavid Hildenbrand if (absent || 6196a7f22660SDavid Hildenbrand __follow_hugetlb_must_fault(flags, pte, &unshare)) { 61972b740303SSouptick Joarder vm_fault_t ret; 619887ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 61994c887265SAdam Litke 6200cb900f41SKirill A. Shutemov if (pte) 6201cb900f41SKirill A. Shutemov spin_unlock(ptl); 620287ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 620387ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 6204a7f22660SDavid Hildenbrand else if (unshare) 6205a7f22660SDavid Hildenbrand fault_flags |= FAULT_FLAG_UNSHARE; 62064f6da934SPeter Xu if (locked) 620771335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 620871335f37SPeter Xu FAULT_FLAG_KILLABLE; 620987ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 621087ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 621187ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 621287ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 62134426e945SPeter Xu /* 62144426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 62154426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 62164426e945SPeter Xu */ 621787ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 621887ffc118SAndrea Arcangeli } 621987ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 622087ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 62212be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 62221c59827dSHugh Dickins remainder = 0; 62231c59827dSHugh Dickins break; 62241c59827dSHugh Dickins } 622587ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 62264f6da934SPeter Xu if (locked && 62271ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 62284f6da934SPeter Xu *locked = 0; 622987ffc118SAndrea Arcangeli *nr_pages = 0; 623087ffc118SAndrea Arcangeli /* 623187ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 623287ffc118SAndrea Arcangeli * error, it will return zero 623387ffc118SAndrea Arcangeli * instead. 623487ffc118SAndrea Arcangeli * 623587ffc118SAndrea Arcangeli * No need to update "position" as the 623687ffc118SAndrea Arcangeli * caller will not check it after 623787ffc118SAndrea Arcangeli * *nr_pages is set to 0. 623887ffc118SAndrea Arcangeli */ 623987ffc118SAndrea Arcangeli return i; 624087ffc118SAndrea Arcangeli } 624187ffc118SAndrea Arcangeli continue; 624287ffc118SAndrea Arcangeli } 624363551ae0SDavid Gibson 6244a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 62457f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 62468fde12caSLinus Torvalds 6247b6a2619cSDavid Hildenbrand VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && 6248b6a2619cSDavid Hildenbrand !PageAnonExclusive(page), page); 6249b6a2619cSDavid Hildenbrand 62508fde12caSLinus Torvalds /* 6251acbfb087SZhigang Lu * If subpage information not requested, update counters 6252acbfb087SZhigang Lu * and skip the same_page loop below. 6253acbfb087SZhigang Lu */ 6254acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 6255acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 6256acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 6257acbfb087SZhigang Lu vaddr += huge_page_size(h); 6258acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 6259acbfb087SZhigang Lu i += pages_per_huge_page(h); 6260acbfb087SZhigang Lu spin_unlock(ptl); 6261acbfb087SZhigang Lu continue; 6262acbfb087SZhigang Lu } 6263acbfb087SZhigang Lu 6264d08af0a5SJoao Martins /* vaddr may not be aligned to PAGE_SIZE */ 6265d08af0a5SJoao Martins refs = min3(pages_per_huge_page(h) - pfn_offset, remainder, 6266d08af0a5SJoao Martins (vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT); 62670fa5bc40SJoao Martins 626882e5d378SJoao Martins if (pages || vmas) 626914455eabSCheng Li record_subpages_vmas(nth_page(page, pfn_offset), 627082e5d378SJoao Martins vma, refs, 627182e5d378SJoao Martins likely(pages) ? pages + i : NULL, 627282e5d378SJoao Martins vmas ? vmas + i : NULL); 627363551ae0SDavid Gibson 627482e5d378SJoao Martins if (pages) { 62750fa5bc40SJoao Martins /* 6276822951d8SMatthew Wilcox (Oracle) * try_grab_folio() should always succeed here, 62770fa5bc40SJoao Martins * because: a) we hold the ptl lock, and b) we've just 62780fa5bc40SJoao Martins * checked that the huge page is present in the page 62790fa5bc40SJoao Martins * tables. If the huge page is present, then the tail 62800fa5bc40SJoao Martins * pages must also be present. The ptl prevents the 62810fa5bc40SJoao Martins * head page and tail pages from being rearranged in 62820fa5bc40SJoao Martins * any way. So this page must be available at this 62830fa5bc40SJoao Martins * point, unless the page refcount overflowed: 62840fa5bc40SJoao Martins */ 6285822951d8SMatthew Wilcox (Oracle) if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs, 62860fa5bc40SJoao Martins flags))) { 62870fa5bc40SJoao Martins spin_unlock(ptl); 62880fa5bc40SJoao Martins remainder = 0; 62890fa5bc40SJoao Martins err = -ENOMEM; 62900fa5bc40SJoao Martins break; 62910fa5bc40SJoao Martins } 6292d5d4b0aaSChen, Kenneth W } 629382e5d378SJoao Martins 629482e5d378SJoao Martins vaddr += (refs << PAGE_SHIFT); 629582e5d378SJoao Martins remainder -= refs; 629682e5d378SJoao Martins i += refs; 629782e5d378SJoao Martins 6298cb900f41SKirill A. Shutemov spin_unlock(ptl); 629963551ae0SDavid Gibson } 630028a35716SMichel Lespinasse *nr_pages = remainder; 630187ffc118SAndrea Arcangeli /* 630287ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 630387ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 630487ffc118SAndrea Arcangeli * branch. 630587ffc118SAndrea Arcangeli */ 630663551ae0SDavid Gibson *position = vaddr; 630763551ae0SDavid Gibson 63082be7cfedSDaniel Jordan return i ? i : err; 630963551ae0SDavid Gibson } 63108f860591SZhang, Yanmin 63117da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 63125a90d5a1SPeter Xu unsigned long address, unsigned long end, 63135a90d5a1SPeter Xu pgprot_t newprot, unsigned long cp_flags) 63148f860591SZhang, Yanmin { 63158f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 63168f860591SZhang, Yanmin unsigned long start = address; 63178f860591SZhang, Yanmin pte_t *ptep; 63188f860591SZhang, Yanmin pte_t pte; 6319a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 632060dfaad6SPeter Xu unsigned long pages = 0, psize = huge_page_size(h); 6321dff11abeSMike Kravetz bool shared_pmd = false; 6322ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 6323e95a9851SMike Kravetz unsigned long last_addr_mask; 63245a90d5a1SPeter Xu bool uffd_wp = cp_flags & MM_CP_UFFD_WP; 63255a90d5a1SPeter Xu bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; 6326dff11abeSMike Kravetz 6327dff11abeSMike Kravetz /* 6328dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 6329ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 6330dff11abeSMike Kravetz * range if PMD sharing is possible. 6331dff11abeSMike Kravetz */ 63327269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 63337269f999SJérôme Glisse 0, vma, mm, start, end); 6334ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 63358f860591SZhang, Yanmin 63368f860591SZhang, Yanmin BUG_ON(address >= end); 6337ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 63388f860591SZhang, Yanmin 6339ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 634040549ba8SMike Kravetz hugetlb_vma_lock_write(vma); 634183cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 634240549ba8SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 634360dfaad6SPeter Xu for (; address < end; address += psize) { 6344cb900f41SKirill A. Shutemov spinlock_t *ptl; 634560dfaad6SPeter Xu ptep = huge_pte_offset(mm, address, psize); 6346e95a9851SMike Kravetz if (!ptep) { 6347e95a9851SMike Kravetz address |= last_addr_mask; 63488f860591SZhang, Yanmin continue; 6349e95a9851SMike Kravetz } 6350cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 63514ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, address, ptep)) { 635260dfaad6SPeter Xu /* 635360dfaad6SPeter Xu * When uffd-wp is enabled on the vma, unshare 635460dfaad6SPeter Xu * shouldn't happen at all. Warn about it if it 635560dfaad6SPeter Xu * happened due to some reason. 635660dfaad6SPeter Xu */ 635760dfaad6SPeter Xu WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); 63587da4d641SPeter Zijlstra pages++; 6359cb900f41SKirill A. Shutemov spin_unlock(ptl); 6360dff11abeSMike Kravetz shared_pmd = true; 63614ddb4d91SMike Kravetz address |= last_addr_mask; 636239dde65cSChen, Kenneth W continue; 63637da4d641SPeter Zijlstra } 6364a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 6365a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 6366a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6367a8bda28dSNaoya Horiguchi continue; 6368a8bda28dSNaoya Horiguchi } 6369a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 6370a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 63716c287605SDavid Hildenbrand struct page *page = pfn_swap_entry_to_page(entry); 6372a8bda28dSNaoya Horiguchi 63736c287605SDavid Hildenbrand if (!is_readable_migration_entry(entry)) { 6374a8bda28dSNaoya Horiguchi pte_t newpte; 6375a8bda28dSNaoya Horiguchi 63766c287605SDavid Hildenbrand if (PageAnon(page)) 63776c287605SDavid Hildenbrand entry = make_readable_exclusive_migration_entry( 63786c287605SDavid Hildenbrand swp_offset(entry)); 63796c287605SDavid Hildenbrand else 63804dd845b5SAlistair Popple entry = make_readable_migration_entry( 63814dd845b5SAlistair Popple swp_offset(entry)); 6382a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 63835a90d5a1SPeter Xu if (uffd_wp) 63845a90d5a1SPeter Xu newpte = pte_swp_mkuffd_wp(newpte); 63855a90d5a1SPeter Xu else if (uffd_wp_resolve) 63865a90d5a1SPeter Xu newpte = pte_swp_clear_uffd_wp(newpte); 638718f39629SQi Zheng set_huge_pte_at(mm, address, ptep, newpte); 6388a8bda28dSNaoya Horiguchi pages++; 6389a8bda28dSNaoya Horiguchi } 6390a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6391a8bda28dSNaoya Horiguchi continue; 6392a8bda28dSNaoya Horiguchi } 639360dfaad6SPeter Xu if (unlikely(pte_marker_uffd_wp(pte))) { 639460dfaad6SPeter Xu /* 639560dfaad6SPeter Xu * This is changing a non-present pte into a none pte, 639660dfaad6SPeter Xu * no need for huge_ptep_modify_prot_start/commit(). 639760dfaad6SPeter Xu */ 639860dfaad6SPeter Xu if (uffd_wp_resolve) 639960dfaad6SPeter Xu huge_pte_clear(mm, address, ptep, psize); 640060dfaad6SPeter Xu } 6401a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 6402023bdd00SAneesh Kumar K.V pte_t old_pte; 640379c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 6404023bdd00SAneesh Kumar K.V 6405023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 640616785bd7SAnshuman Khandual pte = huge_pte_modify(old_pte, newprot); 640779c1c594SChristophe Leroy pte = arch_make_huge_pte(pte, shift, vma->vm_flags); 64085a90d5a1SPeter Xu if (uffd_wp) 64095a90d5a1SPeter Xu pte = huge_pte_mkuffd_wp(huge_pte_wrprotect(pte)); 64105a90d5a1SPeter Xu else if (uffd_wp_resolve) 64115a90d5a1SPeter Xu pte = huge_pte_clear_uffd_wp(pte); 6412023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 64137da4d641SPeter Zijlstra pages++; 641460dfaad6SPeter Xu } else { 641560dfaad6SPeter Xu /* None pte */ 641660dfaad6SPeter Xu if (unlikely(uffd_wp)) 641760dfaad6SPeter Xu /* Safe to modify directly (none->non-present). */ 641860dfaad6SPeter Xu set_huge_pte_at(mm, address, ptep, 641960dfaad6SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 64208f860591SZhang, Yanmin } 6421cb900f41SKirill A. Shutemov spin_unlock(ptl); 64228f860591SZhang, Yanmin } 6423d833352aSMel Gorman /* 6424c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 6425d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 6426c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 6427dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 6428dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 6429d833352aSMel Gorman */ 6430dff11abeSMike Kravetz if (shared_pmd) 6431ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 6432dff11abeSMike Kravetz else 64335491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 64340f10851eSJérôme Glisse /* 64350f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 64360f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 64370f10851eSJérôme Glisse * 6438ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 64390f10851eSJérôme Glisse */ 644083cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 644140549ba8SMike Kravetz hugetlb_vma_unlock_write(vma); 6442ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 64437da4d641SPeter Zijlstra 64447da4d641SPeter Zijlstra return pages << h->order; 64458f860591SZhang, Yanmin } 64468f860591SZhang, Yanmin 644733b8f84aSMike Kravetz /* Return true if reservation was successful, false otherwise. */ 644833b8f84aSMike Kravetz bool hugetlb_reserve_pages(struct inode *inode, 6449a1e78772SMel Gorman long from, long to, 64505a6fe125SMel Gorman struct vm_area_struct *vma, 6451ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 6452e4e574b7SAdam Litke { 645333b8f84aSMike Kravetz long chg, add = -1; 6454a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 645590481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 64569119a41eSJoonsoo Kim struct resv_map *resv_map; 6457075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 64580db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 6459e4e574b7SAdam Litke 646063489f8eSMike Kravetz /* This should never happen */ 646163489f8eSMike Kravetz if (from > to) { 646263489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 646333b8f84aSMike Kravetz return false; 646463489f8eSMike Kravetz } 646563489f8eSMike Kravetz 6466a1e78772SMel Gorman /* 64678d9bfb26SMike Kravetz * vma specific semaphore used for pmd sharing synchronization 64688d9bfb26SMike Kravetz */ 64698d9bfb26SMike Kravetz hugetlb_vma_lock_alloc(vma); 64708d9bfb26SMike Kravetz 64718d9bfb26SMike Kravetz /* 647217c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 647317c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 647490481622SDavid Gibson * without using reserves 647517c9d12eSMel Gorman */ 6476ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 647733b8f84aSMike Kravetz return true; 647817c9d12eSMel Gorman 647917c9d12eSMel Gorman /* 6480a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 6481a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 6482a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 6483a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 6484a1e78772SMel Gorman */ 64859119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 6486f27a5136SMike Kravetz /* 6487f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 6488f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 6489f27a5136SMike Kravetz * hugetlbfs_get_inode). 6490f27a5136SMike Kravetz */ 64914e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 64929119a41eSJoonsoo Kim 64930db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 64949119a41eSJoonsoo Kim } else { 6495e9fe92aeSMina Almasry /* Private mapping. */ 64969119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 64975a6fe125SMel Gorman if (!resv_map) 64988d9bfb26SMike Kravetz goto out_err; 64995a6fe125SMel Gorman 650017c9d12eSMel Gorman chg = to - from; 650117c9d12eSMel Gorman 65025a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 65035a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 65045a6fe125SMel Gorman } 65055a6fe125SMel Gorman 650633b8f84aSMike Kravetz if (chg < 0) 6507c50ac050SDave Hansen goto out_err; 650817c9d12eSMel Gorman 650933b8f84aSMike Kravetz if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h), 651033b8f84aSMike Kravetz chg * pages_per_huge_page(h), &h_cg) < 0) 6511075a61d0SMina Almasry goto out_err; 6512075a61d0SMina Almasry 6513075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 6514075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 6515075a61d0SMina Almasry * of the resv_map. 6516075a61d0SMina Almasry */ 6517075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 6518075a61d0SMina Almasry } 6519075a61d0SMina Almasry 65201c5ecae3SMike Kravetz /* 65211c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 65221c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 65231c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 65241c5ecae3SMike Kravetz */ 65251c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 652633b8f84aSMike Kravetz if (gbl_reserve < 0) 6527075a61d0SMina Almasry goto out_uncharge_cgroup; 652817c9d12eSMel Gorman 652917c9d12eSMel Gorman /* 653017c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 653190481622SDavid Gibson * Hand the pages back to the subpool if there are not 653217c9d12eSMel Gorman */ 653333b8f84aSMike Kravetz if (hugetlb_acct_memory(h, gbl_reserve) < 0) 6534075a61d0SMina Almasry goto out_put_pages; 653517c9d12eSMel Gorman 653617c9d12eSMel Gorman /* 653717c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 653817c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 653917c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 654017c9d12eSMel Gorman * the reservation was and the page cache tells how much of 654117c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 654217c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 654317c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 654417c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 654517c9d12eSMel Gorman * else has to be done for private mappings here 654617c9d12eSMel Gorman */ 654733039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 6548075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 654933039678SMike Kravetz 65500db9d74eSMina Almasry if (unlikely(add < 0)) { 65510db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 6552075a61d0SMina Almasry goto out_put_pages; 65530db9d74eSMina Almasry } else if (unlikely(chg > add)) { 655433039678SMike Kravetz /* 655533039678SMike Kravetz * pages in this range were added to the reserve 655633039678SMike Kravetz * map between region_chg and region_add. This 655733039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 655833039678SMike Kravetz * the subpool and reserve counts modified above 655933039678SMike Kravetz * based on the difference. 656033039678SMike Kravetz */ 656133039678SMike Kravetz long rsv_adjust; 656233039678SMike Kravetz 6563d85aecf2SMiaohe Lin /* 6564d85aecf2SMiaohe Lin * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the 6565d85aecf2SMiaohe Lin * reference to h_cg->css. See comment below for detail. 6566d85aecf2SMiaohe Lin */ 6567075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 6568075a61d0SMina Almasry hstate_index(h), 6569075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 6570075a61d0SMina Almasry 657133039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 657233039678SMike Kravetz chg - add); 657333039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 6574d85aecf2SMiaohe Lin } else if (h_cg) { 6575d85aecf2SMiaohe Lin /* 6576d85aecf2SMiaohe Lin * The file_regions will hold their own reference to 6577d85aecf2SMiaohe Lin * h_cg->css. So we should release the reference held 6578d85aecf2SMiaohe Lin * via hugetlb_cgroup_charge_cgroup_rsvd() when we are 6579d85aecf2SMiaohe Lin * done. 6580d85aecf2SMiaohe Lin */ 6581d85aecf2SMiaohe Lin hugetlb_cgroup_put_rsvd_cgroup(h_cg); 658233039678SMike Kravetz } 658333039678SMike Kravetz } 658433b8f84aSMike Kravetz return true; 658533b8f84aSMike Kravetz 6586075a61d0SMina Almasry out_put_pages: 6587075a61d0SMina Almasry /* put back original number of pages, chg */ 6588075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 6589075a61d0SMina Almasry out_uncharge_cgroup: 6590075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 6591075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 6592c50ac050SDave Hansen out_err: 65938d9bfb26SMike Kravetz hugetlb_vma_lock_free(vma); 65945e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 65950db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 65960db9d74eSMina Almasry * region_add failed or didn't run. 65970db9d74eSMina Almasry */ 65980db9d74eSMina Almasry if (chg >= 0 && add < 0) 65990db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 6600f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 6601f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 660233b8f84aSMike Kravetz return false; 6603a43a8c39SChen, Kenneth W } 6604a43a8c39SChen, Kenneth W 6605b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 6606b5cec28dSMike Kravetz long freed) 6607a43a8c39SChen, Kenneth W { 6608a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 66094e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 66109119a41eSJoonsoo Kim long chg = 0; 661190481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 66121c5ecae3SMike Kravetz long gbl_reserve; 661345c682a6SKen Chen 6614f27a5136SMike Kravetz /* 6615f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 6616f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 6617f27a5136SMike Kravetz */ 6618b5cec28dSMike Kravetz if (resv_map) { 6619b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 6620b5cec28dSMike Kravetz /* 6621b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 6622b5cec28dSMike Kravetz * must be split and another region descriptor can not be 6623b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 6624b5cec28dSMike Kravetz */ 6625b5cec28dSMike Kravetz if (chg < 0) 6626b5cec28dSMike Kravetz return chg; 6627b5cec28dSMike Kravetz } 6628b5cec28dSMike Kravetz 662945c682a6SKen Chen spin_lock(&inode->i_lock); 6630e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 663145c682a6SKen Chen spin_unlock(&inode->i_lock); 663245c682a6SKen Chen 66331c5ecae3SMike Kravetz /* 66341c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 66351c5ecae3SMike Kravetz * reservations to be released may be adjusted. 6636dddf31a4SMiaohe Lin * 6637dddf31a4SMiaohe Lin * Note that !resv_map implies freed == 0. So (chg - freed) 6638dddf31a4SMiaohe Lin * won't go negative. 66391c5ecae3SMike Kravetz */ 66401c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 66411c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 6642b5cec28dSMike Kravetz 6643b5cec28dSMike Kravetz return 0; 6644a43a8c39SChen, Kenneth W } 664593f70f90SNaoya Horiguchi 66463212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 66473212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 66483212b535SSteve Capper struct vm_area_struct *vma, 66493212b535SSteve Capper unsigned long addr, pgoff_t idx) 66503212b535SSteve Capper { 66513212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 66523212b535SSteve Capper svma->vm_start; 66533212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 66543212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 66553212b535SSteve Capper 66563212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 6657de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 6658de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 66593212b535SSteve Capper 66603212b535SSteve Capper /* 66613212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 66623212b535SSteve Capper * page table page. 66633212b535SSteve Capper */ 66643212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 66653212b535SSteve Capper vm_flags != svm_flags || 666607e51edfSMiaohe Lin !range_in_vma(svma, sbase, s_end)) 66673212b535SSteve Capper return 0; 66683212b535SSteve Capper 66693212b535SSteve Capper return saddr; 66703212b535SSteve Capper } 66713212b535SSteve Capper 667212710fd6SMike Kravetz static bool __vma_aligned_range_pmd_shareable(struct vm_area_struct *vma, 66738d9bfb26SMike Kravetz unsigned long start, unsigned long end, 66748d9bfb26SMike Kravetz bool check_vma_lock) 66753212b535SSteve Capper { 66768d9bfb26SMike Kravetz #ifdef CONFIG_USERFAULTFD 66778d9bfb26SMike Kravetz if (uffd_disable_huge_pmd_share(vma)) 66788d9bfb26SMike Kravetz return false; 66798d9bfb26SMike Kravetz #endif 66803212b535SSteve Capper /* 66813212b535SSteve Capper * check on proper vm_flags and page table alignment 66823212b535SSteve Capper */ 66838d9bfb26SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 668431aafb45SNicholas Krause return false; 66858d9bfb26SMike Kravetz if (check_vma_lock && !vma->vm_private_data) 66868d9bfb26SMike Kravetz return false; 66878d9bfb26SMike Kravetz if (!range_in_vma(vma, start, end)) 66888d9bfb26SMike Kravetz return false; 66898d9bfb26SMike Kravetz return true; 66908d9bfb26SMike Kravetz } 66918d9bfb26SMike Kravetz 66928d9bfb26SMike Kravetz static bool vma_pmd_shareable(struct vm_area_struct *vma) 66938d9bfb26SMike Kravetz { 66948d9bfb26SMike Kravetz unsigned long start = ALIGN(vma->vm_start, PUD_SIZE), 66958d9bfb26SMike Kravetz end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 66968d9bfb26SMike Kravetz 66978d9bfb26SMike Kravetz if (start >= end) 66988d9bfb26SMike Kravetz return false; 66998d9bfb26SMike Kravetz 67008d9bfb26SMike Kravetz return __vma_aligned_range_pmd_shareable(vma, start, end, false); 67013212b535SSteve Capper } 67023212b535SSteve Capper 670312710fd6SMike Kravetz static bool vma_addr_pmd_shareable(struct vm_area_struct *vma, 670412710fd6SMike Kravetz unsigned long addr) 670512710fd6SMike Kravetz { 670612710fd6SMike Kravetz unsigned long start = addr & PUD_MASK; 670712710fd6SMike Kravetz unsigned long end = start + PUD_SIZE; 670812710fd6SMike Kravetz 67098d9bfb26SMike Kravetz return __vma_aligned_range_pmd_shareable(vma, start, end, true); 671012710fd6SMike Kravetz } 671112710fd6SMike Kravetz 6712c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6713c1991e07SPeter Xu { 671412710fd6SMike Kravetz return vma_addr_pmd_shareable(vma, addr); 6715c1991e07SPeter Xu } 6716c1991e07SPeter Xu 67173212b535SSteve Capper /* 6718017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 6719017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 6720017b1660SMike Kravetz * shared pmd mappings. 6721017b1660SMike Kravetz */ 6722017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6723017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6724017b1660SMike Kravetz { 6725a1ba9da8SLi Xinhai unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE), 6726a1ba9da8SLi Xinhai v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 6727017b1660SMike Kravetz 6728a1ba9da8SLi Xinhai /* 6729f0953a1bSIngo Molnar * vma needs to span at least one aligned PUD size, and the range 6730f0953a1bSIngo Molnar * must be at least partially within in. 6731a1ba9da8SLi Xinhai */ 6732a1ba9da8SLi Xinhai if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) || 6733a1ba9da8SLi Xinhai (*end <= v_start) || (*start >= v_end)) 6734017b1660SMike Kravetz return; 6735017b1660SMike Kravetz 673675802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 6737a1ba9da8SLi Xinhai if (*start > v_start) 6738a1ba9da8SLi Xinhai *start = ALIGN_DOWN(*start, PUD_SIZE); 6739017b1660SMike Kravetz 6740a1ba9da8SLi Xinhai if (*end < v_end) 6741a1ba9da8SLi Xinhai *end = ALIGN(*end, PUD_SIZE); 6742017b1660SMike Kravetz } 6743017b1660SMike Kravetz 67448d9bfb26SMike Kravetz static bool __vma_shareable_flags_pmd(struct vm_area_struct *vma) 67458d9bfb26SMike Kravetz { 67468d9bfb26SMike Kravetz return vma->vm_flags & (VM_MAYSHARE | VM_SHARED) && 67478d9bfb26SMike Kravetz vma->vm_private_data; 67488d9bfb26SMike Kravetz } 67498d9bfb26SMike Kravetz 67508d9bfb26SMike Kravetz void hugetlb_vma_lock_read(struct vm_area_struct *vma) 67518d9bfb26SMike Kravetz { 67528d9bfb26SMike Kravetz if (__vma_shareable_flags_pmd(vma)) { 67538d9bfb26SMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 67548d9bfb26SMike Kravetz 67558d9bfb26SMike Kravetz down_read(&vma_lock->rw_sema); 67568d9bfb26SMike Kravetz } 67578d9bfb26SMike Kravetz } 67588d9bfb26SMike Kravetz 67598d9bfb26SMike Kravetz void hugetlb_vma_unlock_read(struct vm_area_struct *vma) 67608d9bfb26SMike Kravetz { 67618d9bfb26SMike Kravetz if (__vma_shareable_flags_pmd(vma)) { 67628d9bfb26SMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 67638d9bfb26SMike Kravetz 67648d9bfb26SMike Kravetz up_read(&vma_lock->rw_sema); 67658d9bfb26SMike Kravetz } 67668d9bfb26SMike Kravetz } 67678d9bfb26SMike Kravetz 67688d9bfb26SMike Kravetz void hugetlb_vma_lock_write(struct vm_area_struct *vma) 67698d9bfb26SMike Kravetz { 67708d9bfb26SMike Kravetz if (__vma_shareable_flags_pmd(vma)) { 67718d9bfb26SMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 67728d9bfb26SMike Kravetz 67738d9bfb26SMike Kravetz down_write(&vma_lock->rw_sema); 67748d9bfb26SMike Kravetz } 67758d9bfb26SMike Kravetz } 67768d9bfb26SMike Kravetz 67778d9bfb26SMike Kravetz void hugetlb_vma_unlock_write(struct vm_area_struct *vma) 67788d9bfb26SMike Kravetz { 67798d9bfb26SMike Kravetz if (__vma_shareable_flags_pmd(vma)) { 67808d9bfb26SMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 67818d9bfb26SMike Kravetz 67828d9bfb26SMike Kravetz up_write(&vma_lock->rw_sema); 67838d9bfb26SMike Kravetz } 67848d9bfb26SMike Kravetz } 67858d9bfb26SMike Kravetz 67868d9bfb26SMike Kravetz int hugetlb_vma_trylock_write(struct vm_area_struct *vma) 67878d9bfb26SMike Kravetz { 67888d9bfb26SMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 67898d9bfb26SMike Kravetz 67908d9bfb26SMike Kravetz if (!__vma_shareable_flags_pmd(vma)) 67918d9bfb26SMike Kravetz return 1; 67928d9bfb26SMike Kravetz 67938d9bfb26SMike Kravetz return down_write_trylock(&vma_lock->rw_sema); 67948d9bfb26SMike Kravetz } 67958d9bfb26SMike Kravetz 67968d9bfb26SMike Kravetz void hugetlb_vma_assert_locked(struct vm_area_struct *vma) 67978d9bfb26SMike Kravetz { 67988d9bfb26SMike Kravetz if (__vma_shareable_flags_pmd(vma)) { 67998d9bfb26SMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 68008d9bfb26SMike Kravetz 68018d9bfb26SMike Kravetz lockdep_assert_held(&vma_lock->rw_sema); 68028d9bfb26SMike Kravetz } 68038d9bfb26SMike Kravetz } 68048d9bfb26SMike Kravetz 68058d9bfb26SMike Kravetz void hugetlb_vma_lock_release(struct kref *kref) 68068d9bfb26SMike Kravetz { 68078d9bfb26SMike Kravetz struct hugetlb_vma_lock *vma_lock = container_of(kref, 68088d9bfb26SMike Kravetz struct hugetlb_vma_lock, refs); 68098d9bfb26SMike Kravetz 68108d9bfb26SMike Kravetz kfree(vma_lock); 68118d9bfb26SMike Kravetz } 68128d9bfb26SMike Kravetz 68138d9bfb26SMike Kravetz static void hugetlb_vma_lock_free(struct vm_area_struct *vma) 68148d9bfb26SMike Kravetz { 68158d9bfb26SMike Kravetz /* 68168d9bfb26SMike Kravetz * Only present in sharable vmas. See comment in 68178d9bfb26SMike Kravetz * __unmap_hugepage_range_final about how VM_SHARED could 68188d9bfb26SMike Kravetz * be set without VM_MAYSHARE. As a result, we need to 68198d9bfb26SMike Kravetz * check if either is set in the free path. 68208d9bfb26SMike Kravetz */ 68218d9bfb26SMike Kravetz if (!vma || !(vma->vm_flags & (VM_MAYSHARE | VM_SHARED))) 68228d9bfb26SMike Kravetz return; 68238d9bfb26SMike Kravetz 68248d9bfb26SMike Kravetz if (vma->vm_private_data) { 68258d9bfb26SMike Kravetz struct hugetlb_vma_lock *vma_lock = vma->vm_private_data; 68268d9bfb26SMike Kravetz 68278d9bfb26SMike Kravetz /* 68288d9bfb26SMike Kravetz * vma_lock structure may or not be released, but it 68298d9bfb26SMike Kravetz * certainly will no longer be attached to vma so clear 68308d9bfb26SMike Kravetz * pointer. 68318d9bfb26SMike Kravetz */ 68328d9bfb26SMike Kravetz vma_lock->vma = NULL; 68338d9bfb26SMike Kravetz kref_put(&vma_lock->refs, hugetlb_vma_lock_release); 68348d9bfb26SMike Kravetz vma->vm_private_data = NULL; 68358d9bfb26SMike Kravetz } 68368d9bfb26SMike Kravetz } 68378d9bfb26SMike Kravetz 68388d9bfb26SMike Kravetz static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma) 68398d9bfb26SMike Kravetz { 68408d9bfb26SMike Kravetz struct hugetlb_vma_lock *vma_lock; 68418d9bfb26SMike Kravetz 68428d9bfb26SMike Kravetz /* Only establish in (flags) sharable vmas */ 68438d9bfb26SMike Kravetz if (!vma || !(vma->vm_flags & VM_MAYSHARE)) 68448d9bfb26SMike Kravetz return; 68458d9bfb26SMike Kravetz 68468d9bfb26SMike Kravetz /* Should never get here with non-NULL vm_private_data */ 68478d9bfb26SMike Kravetz if (vma->vm_private_data) 68488d9bfb26SMike Kravetz return; 68498d9bfb26SMike Kravetz 68508d9bfb26SMike Kravetz /* Check size/alignment for pmd sharing possible */ 68518d9bfb26SMike Kravetz if (!vma_pmd_shareable(vma)) 68528d9bfb26SMike Kravetz return; 68538d9bfb26SMike Kravetz 68548d9bfb26SMike Kravetz vma_lock = kmalloc(sizeof(*vma_lock), GFP_KERNEL); 68558d9bfb26SMike Kravetz if (!vma_lock) 68568d9bfb26SMike Kravetz /* 68578d9bfb26SMike Kravetz * If we can not allocate structure, then vma can not 68588d9bfb26SMike Kravetz * participate in pmd sharing. 68598d9bfb26SMike Kravetz */ 68608d9bfb26SMike Kravetz return; 68618d9bfb26SMike Kravetz 68628d9bfb26SMike Kravetz kref_init(&vma_lock->refs); 68638d9bfb26SMike Kravetz init_rwsem(&vma_lock->rw_sema); 68648d9bfb26SMike Kravetz vma_lock->vma = vma; 68658d9bfb26SMike Kravetz vma->vm_private_data = vma_lock; 68668d9bfb26SMike Kravetz } 68678d9bfb26SMike Kravetz 6868017b1660SMike Kravetz /* 68693212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 68703212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 68713212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 68723a47c54fSMike Kravetz * code much cleaner. pmd allocation is essential for the shared case because 68733a47c54fSMike Kravetz * pud has to be populated inside the same i_mmap_rwsem section - otherwise 68743a47c54fSMike Kravetz * racing tasks could either miss the sharing (see huge_pte_offset) or select a 68753a47c54fSMike Kravetz * bad pmd for sharing. 68763212b535SSteve Capper */ 6877aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6878aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 68793212b535SSteve Capper { 68803212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 68813212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 68823212b535SSteve Capper vma->vm_pgoff; 68833212b535SSteve Capper struct vm_area_struct *svma; 68843212b535SSteve Capper unsigned long saddr; 68853212b535SSteve Capper pte_t *spte = NULL; 68863212b535SSteve Capper pte_t *pte; 6887cb900f41SKirill A. Shutemov spinlock_t *ptl; 68883212b535SSteve Capper 68893a47c54fSMike Kravetz i_mmap_lock_read(mapping); 68903212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 68913212b535SSteve Capper if (svma == vma) 68923212b535SSteve Capper continue; 68933212b535SSteve Capper 68943212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 68953212b535SSteve Capper if (saddr) { 68967868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 68977868a208SPunit Agrawal vma_mmu_pagesize(svma)); 68983212b535SSteve Capper if (spte) { 68993212b535SSteve Capper get_page(virt_to_page(spte)); 69003212b535SSteve Capper break; 69013212b535SSteve Capper } 69023212b535SSteve Capper } 69033212b535SSteve Capper } 69043212b535SSteve Capper 69053212b535SSteve Capper if (!spte) 69063212b535SSteve Capper goto out; 69073212b535SSteve Capper 69088bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 6909dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 69103212b535SSteve Capper pud_populate(mm, pud, 69113212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 6912c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 6913dc6c9a35SKirill A. Shutemov } else { 69143212b535SSteve Capper put_page(virt_to_page(spte)); 6915dc6c9a35SKirill A. Shutemov } 6916cb900f41SKirill A. Shutemov spin_unlock(ptl); 69173212b535SSteve Capper out: 69183212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 69193a47c54fSMike Kravetz i_mmap_unlock_read(mapping); 69203212b535SSteve Capper return pte; 69213212b535SSteve Capper } 69223212b535SSteve Capper 69233212b535SSteve Capper /* 69243212b535SSteve Capper * unmap huge page backed by shared pte. 69253212b535SSteve Capper * 69263212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 69273212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 69283212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 69293212b535SSteve Capper * 69303a47c54fSMike Kravetz * Called with page table lock held. 69313212b535SSteve Capper * 69323212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 69333212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 69343212b535SSteve Capper */ 693534ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 69364ddb4d91SMike Kravetz unsigned long addr, pte_t *ptep) 69373212b535SSteve Capper { 69384ddb4d91SMike Kravetz pgd_t *pgd = pgd_offset(mm, addr); 69394ddb4d91SMike Kravetz p4d_t *p4d = p4d_offset(pgd, addr); 69404ddb4d91SMike Kravetz pud_t *pud = pud_offset(p4d, addr); 69413212b535SSteve Capper 694234ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 694340549ba8SMike Kravetz hugetlb_vma_assert_locked(vma); 69443212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 69453212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 69463212b535SSteve Capper return 0; 69473212b535SSteve Capper 69483212b535SSteve Capper pud_clear(pud); 69493212b535SSteve Capper put_page(virt_to_page(ptep)); 6950dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 69513212b535SSteve Capper return 1; 69523212b535SSteve Capper } 6953c1991e07SPeter Xu 69549e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 69558d9bfb26SMike Kravetz 695640549ba8SMike Kravetz void hugetlb_vma_lock_read(struct vm_area_struct *vma) 695740549ba8SMike Kravetz { 695840549ba8SMike Kravetz } 695940549ba8SMike Kravetz 696040549ba8SMike Kravetz void hugetlb_vma_unlock_read(struct vm_area_struct *vma) 696140549ba8SMike Kravetz { 696240549ba8SMike Kravetz } 696340549ba8SMike Kravetz 696440549ba8SMike Kravetz void hugetlb_vma_lock_write(struct vm_area_struct *vma) 696540549ba8SMike Kravetz { 696640549ba8SMike Kravetz } 696740549ba8SMike Kravetz 696840549ba8SMike Kravetz void hugetlb_vma_unlock_write(struct vm_area_struct *vma) 696940549ba8SMike Kravetz { 697040549ba8SMike Kravetz } 697140549ba8SMike Kravetz 697240549ba8SMike Kravetz int hugetlb_vma_trylock_write(struct vm_area_struct *vma) 697340549ba8SMike Kravetz { 697440549ba8SMike Kravetz return 1; 697540549ba8SMike Kravetz } 697640549ba8SMike Kravetz 697740549ba8SMike Kravetz void hugetlb_vma_assert_locked(struct vm_area_struct *vma) 697840549ba8SMike Kravetz { 697940549ba8SMike Kravetz } 698040549ba8SMike Kravetz 69818d9bfb26SMike Kravetz void hugetlb_vma_lock_release(struct kref *kref) 69828d9bfb26SMike Kravetz { 69838d9bfb26SMike Kravetz } 69848d9bfb26SMike Kravetz 69858d9bfb26SMike Kravetz static void hugetlb_vma_lock_free(struct vm_area_struct *vma) 69868d9bfb26SMike Kravetz { 69878d9bfb26SMike Kravetz } 69888d9bfb26SMike Kravetz 69898d9bfb26SMike Kravetz static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma) 69908d9bfb26SMike Kravetz { 69918d9bfb26SMike Kravetz } 69928d9bfb26SMike Kravetz 6993aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6994aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 69959e5fc74cSSteve Capper { 69969e5fc74cSSteve Capper return NULL; 69979e5fc74cSSteve Capper } 6998e81f2d22SZhang Zhen 699934ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 70004ddb4d91SMike Kravetz unsigned long addr, pte_t *ptep) 7001e81f2d22SZhang Zhen { 7002e81f2d22SZhang Zhen return 0; 7003e81f2d22SZhang Zhen } 7004017b1660SMike Kravetz 7005017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 7006017b1660SMike Kravetz unsigned long *start, unsigned long *end) 7007017b1660SMike Kravetz { 7008017b1660SMike Kravetz } 7009c1991e07SPeter Xu 7010c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 7011c1991e07SPeter Xu { 7012c1991e07SPeter Xu return false; 7013c1991e07SPeter Xu } 70143212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 70153212b535SSteve Capper 70169e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 7017aec44e0fSPeter Xu pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 70189e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 70199e5fc74cSSteve Capper { 70209e5fc74cSSteve Capper pgd_t *pgd; 7021c2febafcSKirill A. Shutemov p4d_t *p4d; 70229e5fc74cSSteve Capper pud_t *pud; 70239e5fc74cSSteve Capper pte_t *pte = NULL; 70249e5fc74cSSteve Capper 70259e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 7026f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 7027f4f0a3d8SKirill A. Shutemov if (!p4d) 7028f4f0a3d8SKirill A. Shutemov return NULL; 7029c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 70309e5fc74cSSteve Capper if (pud) { 70319e5fc74cSSteve Capper if (sz == PUD_SIZE) { 70329e5fc74cSSteve Capper pte = (pte_t *)pud; 70339e5fc74cSSteve Capper } else { 70349e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 7035c1991e07SPeter Xu if (want_pmd_share(vma, addr) && pud_none(*pud)) 7036aec44e0fSPeter Xu pte = huge_pmd_share(mm, vma, addr, pud); 70379e5fc74cSSteve Capper else 70389e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 70399e5fc74cSSteve Capper } 70409e5fc74cSSteve Capper } 70414e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 70429e5fc74cSSteve Capper 70439e5fc74cSSteve Capper return pte; 70449e5fc74cSSteve Capper } 70459e5fc74cSSteve Capper 70469b19df29SPunit Agrawal /* 70479b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 70489b19df29SPunit Agrawal * entry at address @addr 70499b19df29SPunit Agrawal * 70508ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 70518ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 70529b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 70539b19df29SPunit Agrawal * table. 70549b19df29SPunit Agrawal */ 70557868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 70567868a208SPunit Agrawal unsigned long addr, unsigned long sz) 70579e5fc74cSSteve Capper { 70589e5fc74cSSteve Capper pgd_t *pgd; 7059c2febafcSKirill A. Shutemov p4d_t *p4d; 70608ac0b81aSLi Xinhai pud_t *pud; 70618ac0b81aSLi Xinhai pmd_t *pmd; 70629e5fc74cSSteve Capper 70639e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 7064c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 7065c2febafcSKirill A. Shutemov return NULL; 7066c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 7067c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 7068c2febafcSKirill A. Shutemov return NULL; 70699b19df29SPunit Agrawal 7070c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 70718ac0b81aSLi Xinhai if (sz == PUD_SIZE) 70728ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 70739e5fc74cSSteve Capper return (pte_t *)pud; 70748ac0b81aSLi Xinhai if (!pud_present(*pud)) 70758ac0b81aSLi Xinhai return NULL; 70768ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 70779b19df29SPunit Agrawal 70789e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 70798ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 70809e5fc74cSSteve Capper return (pte_t *)pmd; 70819e5fc74cSSteve Capper } 70829e5fc74cSSteve Capper 7083e95a9851SMike Kravetz /* 7084e95a9851SMike Kravetz * Return a mask that can be used to update an address to the last huge 7085e95a9851SMike Kravetz * page in a page table page mapping size. Used to skip non-present 7086e95a9851SMike Kravetz * page table entries when linearly scanning address ranges. Architectures 7087e95a9851SMike Kravetz * with unique huge page to page table relationships can define their own 7088e95a9851SMike Kravetz * version of this routine. 7089e95a9851SMike Kravetz */ 7090e95a9851SMike Kravetz unsigned long hugetlb_mask_last_page(struct hstate *h) 7091e95a9851SMike Kravetz { 7092e95a9851SMike Kravetz unsigned long hp_size = huge_page_size(h); 7093e95a9851SMike Kravetz 7094e95a9851SMike Kravetz if (hp_size == PUD_SIZE) 7095e95a9851SMike Kravetz return P4D_SIZE - PUD_SIZE; 7096e95a9851SMike Kravetz else if (hp_size == PMD_SIZE) 7097e95a9851SMike Kravetz return PUD_SIZE - PMD_SIZE; 7098e95a9851SMike Kravetz else 7099e95a9851SMike Kravetz return 0UL; 7100e95a9851SMike Kravetz } 7101e95a9851SMike Kravetz 7102e95a9851SMike Kravetz #else 7103e95a9851SMike Kravetz 7104e95a9851SMike Kravetz /* See description above. Architectures can provide their own version. */ 7105e95a9851SMike Kravetz __weak unsigned long hugetlb_mask_last_page(struct hstate *h) 7106e95a9851SMike Kravetz { 71074ddb4d91SMike Kravetz #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 71084ddb4d91SMike Kravetz if (huge_page_size(h) == PMD_SIZE) 71094ddb4d91SMike Kravetz return PUD_SIZE - PMD_SIZE; 71104ddb4d91SMike Kravetz #endif 7111e95a9851SMike Kravetz return 0UL; 7112e95a9851SMike Kravetz } 7113e95a9851SMike Kravetz 711461f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 711561f77edaSNaoya Horiguchi 711661f77edaSNaoya Horiguchi /* 711761f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 711861f77edaSNaoya Horiguchi * behavior. 711961f77edaSNaoya Horiguchi */ 712061f77edaSNaoya Horiguchi struct page * __weak 712161f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 712261f77edaSNaoya Horiguchi int write) 712361f77edaSNaoya Horiguchi { 712461f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 712561f77edaSNaoya Horiguchi } 712661f77edaSNaoya Horiguchi 712761f77edaSNaoya Horiguchi struct page * __weak 71284dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 71294dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 71304dc71451SAneesh Kumar K.V { 71314dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 71324dc71451SAneesh Kumar K.V return NULL; 71334dc71451SAneesh Kumar K.V } 71344dc71451SAneesh Kumar K.V 71354dc71451SAneesh Kumar K.V struct page * __weak 71369e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 7137e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 71389e5fc74cSSteve Capper { 7139e66f17ffSNaoya Horiguchi struct page *page = NULL; 7140e66f17ffSNaoya Horiguchi spinlock_t *ptl; 7141c9d398faSNaoya Horiguchi pte_t pte; 71423faa52c0SJohn Hubbard 71438909691bSDavid Hildenbrand /* 71448909691bSDavid Hildenbrand * FOLL_PIN is not supported for follow_page(). Ordinary GUP goes via 71458909691bSDavid Hildenbrand * follow_hugetlb_page(). 71468909691bSDavid Hildenbrand */ 71478909691bSDavid Hildenbrand if (WARN_ON_ONCE(flags & FOLL_PIN)) 71483faa52c0SJohn Hubbard return NULL; 71493faa52c0SJohn Hubbard 7150e66f17ffSNaoya Horiguchi retry: 7151e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 7152e66f17ffSNaoya Horiguchi spin_lock(ptl); 7153e66f17ffSNaoya Horiguchi /* 7154e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 7155e66f17ffSNaoya Horiguchi * unmapped from other threads. 7156e66f17ffSNaoya Horiguchi */ 7157e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 7158e66f17ffSNaoya Horiguchi goto out; 7159c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 7160c9d398faSNaoya Horiguchi if (pte_present(pte)) { 716197534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 71623faa52c0SJohn Hubbard /* 71633faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 71643faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 71653faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 71663faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 71673faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 71683faa52c0SJohn Hubbard * unless the page refcount overflowed: 71693faa52c0SJohn Hubbard */ 71703faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 71713faa52c0SJohn Hubbard page = NULL; 71723faa52c0SJohn Hubbard goto out; 71733faa52c0SJohn Hubbard } 7174e66f17ffSNaoya Horiguchi } else { 7175c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 7176e66f17ffSNaoya Horiguchi spin_unlock(ptl); 7177ad1ac596SMiaohe Lin __migration_entry_wait_huge((pte_t *)pmd, ptl); 7178e66f17ffSNaoya Horiguchi goto retry; 7179e66f17ffSNaoya Horiguchi } 7180e66f17ffSNaoya Horiguchi /* 7181e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 7182e66f17ffSNaoya Horiguchi * follow_page_mask(). 7183e66f17ffSNaoya Horiguchi */ 7184e66f17ffSNaoya Horiguchi } 7185e66f17ffSNaoya Horiguchi out: 7186e66f17ffSNaoya Horiguchi spin_unlock(ptl); 71879e5fc74cSSteve Capper return page; 71889e5fc74cSSteve Capper } 71899e5fc74cSSteve Capper 719061f77edaSNaoya Horiguchi struct page * __weak 71919e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 7192e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 71939e5fc74cSSteve Capper { 71943a194f3fSNaoya Horiguchi struct page *page = NULL; 71953a194f3fSNaoya Horiguchi spinlock_t *ptl; 71963a194f3fSNaoya Horiguchi pte_t pte; 71973a194f3fSNaoya Horiguchi 71983a194f3fSNaoya Horiguchi if (WARN_ON_ONCE(flags & FOLL_PIN)) 7199e66f17ffSNaoya Horiguchi return NULL; 72009e5fc74cSSteve Capper 72013a194f3fSNaoya Horiguchi retry: 72023a194f3fSNaoya Horiguchi ptl = huge_pte_lock(hstate_sizelog(PUD_SHIFT), mm, (pte_t *)pud); 72033a194f3fSNaoya Horiguchi if (!pud_huge(*pud)) 72043a194f3fSNaoya Horiguchi goto out; 72053a194f3fSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pud); 72063a194f3fSNaoya Horiguchi if (pte_present(pte)) { 72073a194f3fSNaoya Horiguchi page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 72083a194f3fSNaoya Horiguchi if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 72093a194f3fSNaoya Horiguchi page = NULL; 72103a194f3fSNaoya Horiguchi goto out; 72113a194f3fSNaoya Horiguchi } 72123a194f3fSNaoya Horiguchi } else { 72133a194f3fSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 72143a194f3fSNaoya Horiguchi spin_unlock(ptl); 72153a194f3fSNaoya Horiguchi __migration_entry_wait(mm, (pte_t *)pud, ptl); 72163a194f3fSNaoya Horiguchi goto retry; 72173a194f3fSNaoya Horiguchi } 72183a194f3fSNaoya Horiguchi /* 72193a194f3fSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 72203a194f3fSNaoya Horiguchi * follow_page_mask(). 72213a194f3fSNaoya Horiguchi */ 72223a194f3fSNaoya Horiguchi } 72233a194f3fSNaoya Horiguchi out: 72243a194f3fSNaoya Horiguchi spin_unlock(ptl); 72253a194f3fSNaoya Horiguchi return page; 72269e5fc74cSSteve Capper } 72279e5fc74cSSteve Capper 7228faaa5b62SAnshuman Khandual struct page * __weak 7229faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 7230faaa5b62SAnshuman Khandual { 72313faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 7232faaa5b62SAnshuman Khandual return NULL; 7233faaa5b62SAnshuman Khandual 7234faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 7235faaa5b62SAnshuman Khandual } 7236faaa5b62SAnshuman Khandual 72377ce82f4cSMiaohe Lin int isolate_hugetlb(struct page *page, struct list_head *list) 723831caf665SNaoya Horiguchi { 72397ce82f4cSMiaohe Lin int ret = 0; 7240bcc54222SNaoya Horiguchi 7241db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 72428f251a3dSMike Kravetz if (!PageHeadHuge(page) || 72438f251a3dSMike Kravetz !HPageMigratable(page) || 72440eb2df2bSMuchun Song !get_page_unless_zero(page)) { 72457ce82f4cSMiaohe Lin ret = -EBUSY; 7246bcc54222SNaoya Horiguchi goto unlock; 7247bcc54222SNaoya Horiguchi } 72488f251a3dSMike Kravetz ClearHPageMigratable(page); 724931caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 7250bcc54222SNaoya Horiguchi unlock: 7251db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7252bcc54222SNaoya Horiguchi return ret; 725331caf665SNaoya Horiguchi } 725431caf665SNaoya Horiguchi 725525182f05SNaoya Horiguchi int get_hwpoison_huge_page(struct page *page, bool *hugetlb) 725625182f05SNaoya Horiguchi { 725725182f05SNaoya Horiguchi int ret = 0; 725825182f05SNaoya Horiguchi 725925182f05SNaoya Horiguchi *hugetlb = false; 726025182f05SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 726125182f05SNaoya Horiguchi if (PageHeadHuge(page)) { 726225182f05SNaoya Horiguchi *hugetlb = true; 7263b283d983SNaoya Horiguchi if (HPageFreed(page)) 7264b283d983SNaoya Horiguchi ret = 0; 7265b283d983SNaoya Horiguchi else if (HPageMigratable(page)) 726625182f05SNaoya Horiguchi ret = get_page_unless_zero(page); 72670ed950d1SNaoya Horiguchi else 72680ed950d1SNaoya Horiguchi ret = -EBUSY; 726925182f05SNaoya Horiguchi } 727025182f05SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 727125182f05SNaoya Horiguchi return ret; 727225182f05SNaoya Horiguchi } 727325182f05SNaoya Horiguchi 7274405ce051SNaoya Horiguchi int get_huge_page_for_hwpoison(unsigned long pfn, int flags) 7275405ce051SNaoya Horiguchi { 7276405ce051SNaoya Horiguchi int ret; 7277405ce051SNaoya Horiguchi 7278405ce051SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 7279405ce051SNaoya Horiguchi ret = __get_huge_page_for_hwpoison(pfn, flags); 7280405ce051SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 7281405ce051SNaoya Horiguchi return ret; 7282405ce051SNaoya Horiguchi } 7283405ce051SNaoya Horiguchi 728431caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 728531caf665SNaoya Horiguchi { 7286db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 72878f251a3dSMike Kravetz SetHPageMigratable(page); 728831caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 7289db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 729031caf665SNaoya Horiguchi put_page(page); 729131caf665SNaoya Horiguchi } 7292ab5ac90aSMichal Hocko 7293ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 7294ab5ac90aSMichal Hocko { 7295ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 7296ab5ac90aSMichal Hocko 7297ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 7298ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 7299ab5ac90aSMichal Hocko 7300ab5ac90aSMichal Hocko /* 7301ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 7302ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 7303ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 7304ab5ac90aSMichal Hocko * the temporary status. 7305ab5ac90aSMichal Hocko * 7306ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 7307ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 7308ab5ac90aSMichal Hocko * the per-node's. 7309ab5ac90aSMichal Hocko */ 73109157c311SMike Kravetz if (HPageTemporary(newpage)) { 7311ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 7312ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 7313ab5ac90aSMichal Hocko 73149157c311SMike Kravetz SetHPageTemporary(oldpage); 73159157c311SMike Kravetz ClearHPageTemporary(newpage); 7316ab5ac90aSMichal Hocko 73175af1ab1dSMiaohe Lin /* 73185af1ab1dSMiaohe Lin * There is no need to transfer the per-node surplus state 73195af1ab1dSMiaohe Lin * when we do not cross the node. 73205af1ab1dSMiaohe Lin */ 73215af1ab1dSMiaohe Lin if (new_nid == old_nid) 73225af1ab1dSMiaohe Lin return; 7323db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 7324ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 7325ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 7326ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 7327ab5ac90aSMichal Hocko } 7328db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7329ab5ac90aSMichal Hocko } 7330ab5ac90aSMichal Hocko } 7331cf11e85fSRoman Gushchin 73326dfeaff9SPeter Xu /* 73336dfeaff9SPeter Xu * This function will unconditionally remove all the shared pmd pgtable entries 73346dfeaff9SPeter Xu * within the specific vma for a hugetlbfs memory range. 73356dfeaff9SPeter Xu */ 73366dfeaff9SPeter Xu void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) 73376dfeaff9SPeter Xu { 73386dfeaff9SPeter Xu struct hstate *h = hstate_vma(vma); 73396dfeaff9SPeter Xu unsigned long sz = huge_page_size(h); 73406dfeaff9SPeter Xu struct mm_struct *mm = vma->vm_mm; 73416dfeaff9SPeter Xu struct mmu_notifier_range range; 73426dfeaff9SPeter Xu unsigned long address, start, end; 73436dfeaff9SPeter Xu spinlock_t *ptl; 73446dfeaff9SPeter Xu pte_t *ptep; 73456dfeaff9SPeter Xu 73466dfeaff9SPeter Xu if (!(vma->vm_flags & VM_MAYSHARE)) 73476dfeaff9SPeter Xu return; 73486dfeaff9SPeter Xu 73496dfeaff9SPeter Xu start = ALIGN(vma->vm_start, PUD_SIZE); 73506dfeaff9SPeter Xu end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 73516dfeaff9SPeter Xu 73526dfeaff9SPeter Xu if (start >= end) 73536dfeaff9SPeter Xu return; 73546dfeaff9SPeter Xu 73559c8bbfacSBaolin Wang flush_cache_range(vma, start, end); 73566dfeaff9SPeter Xu /* 73576dfeaff9SPeter Xu * No need to call adjust_range_if_pmd_sharing_possible(), because 73586dfeaff9SPeter Xu * we have already done the PUD_SIZE alignment. 73596dfeaff9SPeter Xu */ 73606dfeaff9SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 73616dfeaff9SPeter Xu start, end); 73626dfeaff9SPeter Xu mmu_notifier_invalidate_range_start(&range); 736340549ba8SMike Kravetz hugetlb_vma_lock_write(vma); 73646dfeaff9SPeter Xu i_mmap_lock_write(vma->vm_file->f_mapping); 73656dfeaff9SPeter Xu for (address = start; address < end; address += PUD_SIZE) { 73666dfeaff9SPeter Xu ptep = huge_pte_offset(mm, address, sz); 73676dfeaff9SPeter Xu if (!ptep) 73686dfeaff9SPeter Xu continue; 73696dfeaff9SPeter Xu ptl = huge_pte_lock(h, mm, ptep); 73704ddb4d91SMike Kravetz huge_pmd_unshare(mm, vma, address, ptep); 73716dfeaff9SPeter Xu spin_unlock(ptl); 73726dfeaff9SPeter Xu } 73736dfeaff9SPeter Xu flush_hugetlb_tlb_range(vma, start, end); 73746dfeaff9SPeter Xu i_mmap_unlock_write(vma->vm_file->f_mapping); 737540549ba8SMike Kravetz hugetlb_vma_unlock_write(vma); 73766dfeaff9SPeter Xu /* 73776dfeaff9SPeter Xu * No need to call mmu_notifier_invalidate_range(), see 7378ee65728eSMike Rapoport * Documentation/mm/mmu_notifier.rst. 73796dfeaff9SPeter Xu */ 73806dfeaff9SPeter Xu mmu_notifier_invalidate_range_end(&range); 73816dfeaff9SPeter Xu } 73826dfeaff9SPeter Xu 7383cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 7384cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 7385cf11e85fSRoman Gushchin 7386cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 7387cf11e85fSRoman Gushchin { 738838e719abSBaolin Wang int nid, count = 0; 738938e719abSBaolin Wang unsigned long tmp; 739038e719abSBaolin Wang char *s = p; 739138e719abSBaolin Wang 739238e719abSBaolin Wang while (*s) { 739338e719abSBaolin Wang if (sscanf(s, "%lu%n", &tmp, &count) != 1) 739438e719abSBaolin Wang break; 739538e719abSBaolin Wang 739638e719abSBaolin Wang if (s[count] == ':') { 7397f9317f77SMike Kravetz if (tmp >= MAX_NUMNODES) 739838e719abSBaolin Wang break; 7399f9317f77SMike Kravetz nid = array_index_nospec(tmp, MAX_NUMNODES); 740038e719abSBaolin Wang 740138e719abSBaolin Wang s += count + 1; 740238e719abSBaolin Wang tmp = memparse(s, &s); 740338e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = tmp; 740438e719abSBaolin Wang hugetlb_cma_size += tmp; 740538e719abSBaolin Wang 740638e719abSBaolin Wang /* 740738e719abSBaolin Wang * Skip the separator if have one, otherwise 740838e719abSBaolin Wang * break the parsing. 740938e719abSBaolin Wang */ 741038e719abSBaolin Wang if (*s == ',') 741138e719abSBaolin Wang s++; 741238e719abSBaolin Wang else 741338e719abSBaolin Wang break; 741438e719abSBaolin Wang } else { 7415cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 741638e719abSBaolin Wang break; 741738e719abSBaolin Wang } 741838e719abSBaolin Wang } 741938e719abSBaolin Wang 7420cf11e85fSRoman Gushchin return 0; 7421cf11e85fSRoman Gushchin } 7422cf11e85fSRoman Gushchin 7423cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 7424cf11e85fSRoman Gushchin 7425cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 7426cf11e85fSRoman Gushchin { 7427cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 742838e719abSBaolin Wang bool node_specific_cma_alloc = false; 7429cf11e85fSRoman Gushchin int nid; 7430cf11e85fSRoman Gushchin 7431cf11e85fSRoman Gushchin cma_reserve_called = true; 7432cf11e85fSRoman Gushchin 7433cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 7434cf11e85fSRoman Gushchin return; 7435cf11e85fSRoman Gushchin 743638e719abSBaolin Wang for (nid = 0; nid < MAX_NUMNODES; nid++) { 743738e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 743838e719abSBaolin Wang continue; 743938e719abSBaolin Wang 744030a51400SPeng Liu if (!node_online(nid)) { 744138e719abSBaolin Wang pr_warn("hugetlb_cma: invalid node %d specified\n", nid); 744238e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 744338e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 744438e719abSBaolin Wang continue; 744538e719abSBaolin Wang } 744638e719abSBaolin Wang 744738e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] < (PAGE_SIZE << order)) { 744838e719abSBaolin Wang pr_warn("hugetlb_cma: cma area of node %d should be at least %lu MiB\n", 744938e719abSBaolin Wang nid, (PAGE_SIZE << order) / SZ_1M); 745038e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 745138e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 745238e719abSBaolin Wang } else { 745338e719abSBaolin Wang node_specific_cma_alloc = true; 745438e719abSBaolin Wang } 745538e719abSBaolin Wang } 745638e719abSBaolin Wang 745738e719abSBaolin Wang /* Validate the CMA size again in case some invalid nodes specified. */ 745838e719abSBaolin Wang if (!hugetlb_cma_size) 745938e719abSBaolin Wang return; 746038e719abSBaolin Wang 7461cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 7462cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 7463cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 7464a01f4390SMike Kravetz hugetlb_cma_size = 0; 7465cf11e85fSRoman Gushchin return; 7466cf11e85fSRoman Gushchin } 7467cf11e85fSRoman Gushchin 746838e719abSBaolin Wang if (!node_specific_cma_alloc) { 7469cf11e85fSRoman Gushchin /* 7470cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 7471cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 7472cf11e85fSRoman Gushchin */ 7473cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 7474cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 7475cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 747638e719abSBaolin Wang } 7477cf11e85fSRoman Gushchin 7478cf11e85fSRoman Gushchin reserved = 0; 747930a51400SPeng Liu for_each_online_node(nid) { 7480cf11e85fSRoman Gushchin int res; 74812281f797SBarry Song char name[CMA_MAX_NAME]; 7482cf11e85fSRoman Gushchin 748338e719abSBaolin Wang if (node_specific_cma_alloc) { 748438e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 748538e719abSBaolin Wang continue; 748638e719abSBaolin Wang 748738e719abSBaolin Wang size = hugetlb_cma_size_in_node[nid]; 748838e719abSBaolin Wang } else { 7489cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 749038e719abSBaolin Wang } 749138e719abSBaolin Wang 7492cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 7493cf11e85fSRoman Gushchin 74942281f797SBarry Song snprintf(name, sizeof(name), "hugetlb%d", nid); 7495a01f4390SMike Kravetz /* 7496a01f4390SMike Kravetz * Note that 'order per bit' is based on smallest size that 7497a01f4390SMike Kravetz * may be returned to CMA allocator in the case of 7498a01f4390SMike Kravetz * huge page demotion. 7499a01f4390SMike Kravetz */ 7500a01f4390SMike Kravetz res = cma_declare_contiguous_nid(0, size, 0, 7501a01f4390SMike Kravetz PAGE_SIZE << HUGETLB_PAGE_ORDER, 750229d0f41dSBarry Song 0, false, name, 7503cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 7504cf11e85fSRoman Gushchin if (res) { 7505cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 7506cf11e85fSRoman Gushchin res, nid); 7507cf11e85fSRoman Gushchin continue; 7508cf11e85fSRoman Gushchin } 7509cf11e85fSRoman Gushchin 7510cf11e85fSRoman Gushchin reserved += size; 7511cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 7512cf11e85fSRoman Gushchin size / SZ_1M, nid); 7513cf11e85fSRoman Gushchin 7514cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 7515cf11e85fSRoman Gushchin break; 7516cf11e85fSRoman Gushchin } 7517a01f4390SMike Kravetz 7518a01f4390SMike Kravetz if (!reserved) 7519a01f4390SMike Kravetz /* 7520a01f4390SMike Kravetz * hugetlb_cma_size is used to determine if allocations from 7521a01f4390SMike Kravetz * cma are possible. Set to zero if no cma regions are set up. 7522a01f4390SMike Kravetz */ 7523a01f4390SMike Kravetz hugetlb_cma_size = 0; 7524cf11e85fSRoman Gushchin } 7525cf11e85fSRoman Gushchin 7526263b8998SMiaohe Lin static void __init hugetlb_cma_check(void) 7527cf11e85fSRoman Gushchin { 7528cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 7529cf11e85fSRoman Gushchin return; 7530cf11e85fSRoman Gushchin 7531cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 7532cf11e85fSRoman Gushchin } 7533cf11e85fSRoman Gushchin 7534cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 7535