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> 33d6606683SLinus Torvalds 3463551ae0SDavid Gibson #include <asm/page.h> 35ca15ca40SMike Rapoport #include <asm/pgalloc.h> 3624669e58SAneesh Kumar K.V #include <asm/tlb.h> 3763551ae0SDavid Gibson 3824669e58SAneesh Kumar K.V #include <linux/io.h> 3963551ae0SDavid Gibson #include <linux/hugetlb.h> 409dd540e2SAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 419a305230SLee Schermerhorn #include <linux/node.h> 421a1aad8aSMike Kravetz #include <linux/userfaultfd_k.h> 43ab5ac90aSMichal Hocko #include <linux/page_owner.h> 447835e98bSNick Piggin #include "internal.h" 451da177e4SLinus Torvalds 46c3f38a38SAneesh Kumar K.V int hugetlb_max_hstate __read_mostly; 47e5ff2159SAndi Kleen unsigned int default_hstate_idx; 48e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 49cf11e85fSRoman Gushchin 50dbda8feaSBarry Song #ifdef CONFIG_CMA 51cf11e85fSRoman Gushchin static struct cma *hugetlb_cma[MAX_NUMNODES]; 52dbda8feaSBarry Song #endif 53dbda8feaSBarry Song static unsigned long hugetlb_cma_size __initdata; 54cf11e85fSRoman Gushchin 55641844f5SNaoya Horiguchi /* 56641844f5SNaoya Horiguchi * Minimum page order among possible hugepage sizes, set to a proper value 57641844f5SNaoya Horiguchi * at boot time. 58641844f5SNaoya Horiguchi */ 59641844f5SNaoya Horiguchi static unsigned int minimum_order __read_mostly = UINT_MAX; 60e5ff2159SAndi Kleen 6153ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 6253ba51d2SJon Tollefson 63e5ff2159SAndi Kleen /* for command line parsing */ 64e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 65e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 669fee021dSVaishali Thakkar static bool __initdata parsed_valid_hugepagesz = true; 67282f4214SMike Kravetz static bool __initdata parsed_default_hugepagesz; 68e5ff2159SAndi Kleen 693935baa9SDavid Gibson /* 7031caf665SNaoya Horiguchi * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, 7131caf665SNaoya Horiguchi * free_huge_pages, and surplus_huge_pages. 723935baa9SDavid Gibson */ 73c3f38a38SAneesh Kumar K.V DEFINE_SPINLOCK(hugetlb_lock); 740bd0f9fbSEric Paris 758382d914SDavidlohr Bueso /* 768382d914SDavidlohr Bueso * Serializes faults on the same logical page. This is used to 778382d914SDavidlohr Bueso * prevent spurious OOMs when the hugepage pool is fully utilized. 788382d914SDavidlohr Bueso */ 798382d914SDavidlohr Bueso static int num_fault_mutexes; 80c672c7f2SMike Kravetz struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; 818382d914SDavidlohr Bueso 827ca02d0aSMike Kravetz /* Forward declaration */ 837ca02d0aSMike Kravetz static int hugetlb_acct_memory(struct hstate *h, long delta); 847ca02d0aSMike Kravetz 8590481622SDavid Gibson static inline void unlock_or_release_subpool(struct hugepage_subpool *spool) 8690481622SDavid Gibson { 8790481622SDavid Gibson bool free = (spool->count == 0) && (spool->used_hpages == 0); 8890481622SDavid Gibson 8990481622SDavid Gibson spin_unlock(&spool->lock); 9090481622SDavid Gibson 9190481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 927c8de358SEthon Paul * remain, give up any reservations based on minimum size and 937ca02d0aSMike Kravetz * free the subpool */ 947ca02d0aSMike Kravetz if (free) { 957ca02d0aSMike Kravetz if (spool->min_hpages != -1) 967ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 977ca02d0aSMike Kravetz -spool->min_hpages); 9890481622SDavid Gibson kfree(spool); 9990481622SDavid Gibson } 1007ca02d0aSMike Kravetz } 10190481622SDavid Gibson 1027ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1037ca02d0aSMike Kravetz long min_hpages) 10490481622SDavid Gibson { 10590481622SDavid Gibson struct hugepage_subpool *spool; 10690481622SDavid Gibson 107c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 10890481622SDavid Gibson if (!spool) 10990481622SDavid Gibson return NULL; 11090481622SDavid Gibson 11190481622SDavid Gibson spin_lock_init(&spool->lock); 11290481622SDavid Gibson spool->count = 1; 1137ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1147ca02d0aSMike Kravetz spool->hstate = h; 1157ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1167ca02d0aSMike Kravetz 1177ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1187ca02d0aSMike Kravetz kfree(spool); 1197ca02d0aSMike Kravetz return NULL; 1207ca02d0aSMike Kravetz } 1217ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 12290481622SDavid Gibson 12390481622SDavid Gibson return spool; 12490481622SDavid Gibson } 12590481622SDavid Gibson 12690481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 12790481622SDavid Gibson { 12890481622SDavid Gibson spin_lock(&spool->lock); 12990481622SDavid Gibson BUG_ON(!spool->count); 13090481622SDavid Gibson spool->count--; 13190481622SDavid Gibson unlock_or_release_subpool(spool); 13290481622SDavid Gibson } 13390481622SDavid Gibson 1341c5ecae3SMike Kravetz /* 1351c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1361c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1379e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1381c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1391c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1407c8de358SEthon Paul * a subpool minimum size must be maintained. 1411c5ecae3SMike Kravetz */ 1421c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 14390481622SDavid Gibson long delta) 14490481622SDavid Gibson { 1451c5ecae3SMike Kravetz long ret = delta; 14690481622SDavid Gibson 14790481622SDavid Gibson if (!spool) 1481c5ecae3SMike Kravetz return ret; 14990481622SDavid Gibson 15090481622SDavid Gibson spin_lock(&spool->lock); 15190481622SDavid Gibson 1521c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1531c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1541c5ecae3SMike Kravetz spool->used_hpages += delta; 1551c5ecae3SMike Kravetz else { 1561c5ecae3SMike Kravetz ret = -ENOMEM; 1571c5ecae3SMike Kravetz goto unlock_ret; 1581c5ecae3SMike Kravetz } 1591c5ecae3SMike Kravetz } 1601c5ecae3SMike Kravetz 16109a95e29SMike Kravetz /* minimum size accounting */ 16209a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1631c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1641c5ecae3SMike Kravetz /* 1651c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1661c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1671c5ecae3SMike Kravetz */ 1681c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1691c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1701c5ecae3SMike Kravetz } else { 1711c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1721c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 1731c5ecae3SMike Kravetz } 1741c5ecae3SMike Kravetz } 1751c5ecae3SMike Kravetz 1761c5ecae3SMike Kravetz unlock_ret: 1771c5ecae3SMike Kravetz spin_unlock(&spool->lock); 17890481622SDavid Gibson return ret; 17990481622SDavid Gibson } 18090481622SDavid Gibson 1811c5ecae3SMike Kravetz /* 1821c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 1831c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 1841c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 1851c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 1861c5ecae3SMike Kravetz */ 1871c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 18890481622SDavid Gibson long delta) 18990481622SDavid Gibson { 1901c5ecae3SMike Kravetz long ret = delta; 1911c5ecae3SMike Kravetz 19290481622SDavid Gibson if (!spool) 1931c5ecae3SMike Kravetz return delta; 19490481622SDavid Gibson 19590481622SDavid Gibson spin_lock(&spool->lock); 1961c5ecae3SMike Kravetz 1971c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 19890481622SDavid Gibson spool->used_hpages -= delta; 1991c5ecae3SMike Kravetz 20009a95e29SMike Kravetz /* minimum size accounting */ 20109a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2021c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2031c5ecae3SMike Kravetz ret = 0; 2041c5ecae3SMike Kravetz else 2051c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2061c5ecae3SMike Kravetz 2071c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2081c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2091c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2101c5ecae3SMike Kravetz } 2111c5ecae3SMike Kravetz 2121c5ecae3SMike Kravetz /* 2131c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2141c5ecae3SMike Kravetz * quota reference, free it now. 2151c5ecae3SMike Kravetz */ 21690481622SDavid Gibson unlock_or_release_subpool(spool); 2171c5ecae3SMike Kravetz 2181c5ecae3SMike Kravetz return ret; 21990481622SDavid Gibson } 22090481622SDavid Gibson 22190481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 22290481622SDavid Gibson { 22390481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 22490481622SDavid Gibson } 22590481622SDavid Gibson 22690481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 22790481622SDavid Gibson { 228496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 22990481622SDavid Gibson } 23090481622SDavid Gibson 2310db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2320db9d74eSMina Almasry * it for use. 2330db9d74eSMina Almasry */ 2340db9d74eSMina Almasry static struct file_region * 2350db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2360db9d74eSMina Almasry { 2370db9d74eSMina Almasry struct file_region *nrg = NULL; 2380db9d74eSMina Almasry 2390db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2400db9d74eSMina Almasry 2410db9d74eSMina Almasry resv->region_cache_count--; 2420db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2430db9d74eSMina Almasry list_del(&nrg->link); 2440db9d74eSMina Almasry 2450db9d74eSMina Almasry nrg->from = from; 2460db9d74eSMina Almasry nrg->to = to; 2470db9d74eSMina Almasry 2480db9d74eSMina Almasry return nrg; 2490db9d74eSMina Almasry } 2500db9d74eSMina Almasry 251075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 252075a61d0SMina Almasry struct file_region *rg) 253075a61d0SMina Almasry { 254075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 255075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 256075a61d0SMina Almasry nrg->css = rg->css; 257075a61d0SMina Almasry if (rg->css) 258075a61d0SMina Almasry css_get(rg->css); 259075a61d0SMina Almasry #endif 260075a61d0SMina Almasry } 261075a61d0SMina Almasry 262075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 263075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 264075a61d0SMina Almasry struct hstate *h, 265075a61d0SMina Almasry struct resv_map *resv, 266075a61d0SMina Almasry struct file_region *nrg) 267075a61d0SMina Almasry { 268075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 269075a61d0SMina Almasry if (h_cg) { 270075a61d0SMina Almasry nrg->reservation_counter = 271075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 272075a61d0SMina Almasry nrg->css = &h_cg->css; 273075a61d0SMina Almasry if (!resv->pages_per_hpage) 274075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 275075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 276075a61d0SMina Almasry * a resv_map. 277075a61d0SMina Almasry */ 278075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 279075a61d0SMina Almasry } else { 280075a61d0SMina Almasry nrg->reservation_counter = NULL; 281075a61d0SMina Almasry nrg->css = NULL; 282075a61d0SMina Almasry } 283075a61d0SMina Almasry #endif 284075a61d0SMina Almasry } 285075a61d0SMina Almasry 286a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 287a9b3f867SMina Almasry struct file_region *org) 288a9b3f867SMina Almasry { 289a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 290a9b3f867SMina Almasry return rg && org && 291a9b3f867SMina Almasry rg->reservation_counter == org->reservation_counter && 292a9b3f867SMina Almasry rg->css == org->css; 293a9b3f867SMina Almasry 294a9b3f867SMina Almasry #else 295a9b3f867SMina Almasry return true; 296a9b3f867SMina Almasry #endif 297a9b3f867SMina Almasry } 298a9b3f867SMina Almasry 299a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 300a9b3f867SMina Almasry { 301a9b3f867SMina Almasry struct file_region *nrg = NULL, *prg = NULL; 302a9b3f867SMina Almasry 303a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 304a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 305a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 306a9b3f867SMina Almasry prg->to = rg->to; 307a9b3f867SMina Almasry 308a9b3f867SMina Almasry list_del(&rg->link); 309a9b3f867SMina Almasry kfree(rg); 310a9b3f867SMina Almasry 3117db5e7b6SWei Yang rg = prg; 312a9b3f867SMina Almasry } 313a9b3f867SMina Almasry 314a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 315a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 316a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 317a9b3f867SMina Almasry nrg->from = rg->from; 318a9b3f867SMina Almasry 319a9b3f867SMina Almasry list_del(&rg->link); 320a9b3f867SMina Almasry kfree(rg); 321a9b3f867SMina Almasry } 322a9b3f867SMina Almasry } 323a9b3f867SMina Almasry 324972a3da3SWei Yang /* 325972a3da3SWei Yang * Must be called with resv->lock held. 326972a3da3SWei Yang * 327972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 328972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 329972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 330972a3da3SWei Yang * the regions for this range. 331d75c6af9SMina Almasry */ 332d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 333075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 334972a3da3SWei Yang struct hstate *h, long *regions_needed) 335d75c6af9SMina Almasry { 3360db9d74eSMina Almasry long add = 0; 337d75c6af9SMina Almasry struct list_head *head = &resv->regions; 3380db9d74eSMina Almasry long last_accounted_offset = f; 339d75c6af9SMina Almasry struct file_region *rg = NULL, *trg = NULL, *nrg = NULL; 340d75c6af9SMina Almasry 3410db9d74eSMina Almasry if (regions_needed) 3420db9d74eSMina Almasry *regions_needed = 0; 343d75c6af9SMina Almasry 3440db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 3450db9d74eSMina Almasry * [last_accounted_offset, rg->from), at every iteration, with some 3460db9d74eSMina Almasry * bounds checking. 3470db9d74eSMina Almasry */ 3480db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, head, link) { 3490db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 3500db9d74eSMina Almasry if (rg->from < f) { 3510db9d74eSMina Almasry /* If this region ends after the last accounted offset, 3520db9d74eSMina Almasry * then we need to update last_accounted_offset. 3530db9d74eSMina Almasry */ 3540db9d74eSMina Almasry if (rg->to > last_accounted_offset) 3550db9d74eSMina Almasry last_accounted_offset = rg->to; 3560db9d74eSMina Almasry continue; 3570db9d74eSMina Almasry } 358d75c6af9SMina Almasry 3590db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 3600db9d74eSMina Almasry * finished. 3610db9d74eSMina Almasry */ 362d75c6af9SMina Almasry if (rg->from > t) 363d75c6af9SMina Almasry break; 364d75c6af9SMina Almasry 3650db9d74eSMina Almasry /* Add an entry for last_accounted_offset -> rg->from, and 3660db9d74eSMina Almasry * update last_accounted_offset. 367d75c6af9SMina Almasry */ 3680db9d74eSMina Almasry if (rg->from > last_accounted_offset) { 3690db9d74eSMina Almasry add += rg->from - last_accounted_offset; 370972a3da3SWei Yang if (!regions_needed) { 3710db9d74eSMina Almasry nrg = get_file_region_entry_from_cache( 3720db9d74eSMina Almasry resv, last_accounted_offset, rg->from); 373075a61d0SMina Almasry record_hugetlb_cgroup_uncharge_info(h_cg, h, 374075a61d0SMina Almasry resv, nrg); 3750db9d74eSMina Almasry list_add(&nrg->link, rg->link.prev); 376a9b3f867SMina Almasry coalesce_file_region(resv, nrg); 377972a3da3SWei Yang } else 3780db9d74eSMina Almasry *regions_needed += 1; 379d75c6af9SMina Almasry } 380d75c6af9SMina Almasry 3810db9d74eSMina Almasry last_accounted_offset = rg->to; 3820db9d74eSMina Almasry } 3830db9d74eSMina Almasry 3840db9d74eSMina Almasry /* Handle the case where our range extends beyond 3850db9d74eSMina Almasry * last_accounted_offset. 3860db9d74eSMina Almasry */ 3870db9d74eSMina Almasry if (last_accounted_offset < t) { 3880db9d74eSMina Almasry add += t - last_accounted_offset; 389972a3da3SWei Yang if (!regions_needed) { 3900db9d74eSMina Almasry nrg = get_file_region_entry_from_cache( 3910db9d74eSMina Almasry resv, last_accounted_offset, t); 392075a61d0SMina Almasry record_hugetlb_cgroup_uncharge_info(h_cg, h, resv, nrg); 3930db9d74eSMina Almasry list_add(&nrg->link, rg->link.prev); 394a9b3f867SMina Almasry coalesce_file_region(resv, nrg); 395972a3da3SWei Yang } else 3960db9d74eSMina Almasry *regions_needed += 1; 3970db9d74eSMina Almasry } 3980db9d74eSMina Almasry 3990db9d74eSMina Almasry VM_BUG_ON(add < 0); 4000db9d74eSMina Almasry return add; 4010db9d74eSMina Almasry } 4020db9d74eSMina Almasry 4030db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4040db9d74eSMina Almasry */ 4050db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4060db9d74eSMina Almasry int regions_needed) 4070db9d74eSMina Almasry __must_hold(&resv->lock) 4080db9d74eSMina Almasry { 4090db9d74eSMina Almasry struct list_head allocated_regions; 4100db9d74eSMina Almasry int to_allocate = 0, i = 0; 4110db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4120db9d74eSMina Almasry 4130db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4140db9d74eSMina Almasry 4150db9d74eSMina Almasry INIT_LIST_HEAD(&allocated_regions); 4160db9d74eSMina Almasry 4170db9d74eSMina Almasry /* 4180db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4190db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 4200db9d74eSMina Almasry * 4210db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 4220db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 4230db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 4240db9d74eSMina Almasry * (adds_in_progress + regions_needed). 4250db9d74eSMina Almasry */ 4260db9d74eSMina Almasry while (resv->region_cache_count < 4270db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 4280db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 4290db9d74eSMina Almasry resv->region_cache_count; 4300db9d74eSMina Almasry 4310db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 4320db9d74eSMina Almasry * for all the existings adds_in_progress. We should only be 4330db9d74eSMina Almasry * needing to allocate for regions_needed. 4340db9d74eSMina Almasry */ 4350db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 4360db9d74eSMina Almasry 4370db9d74eSMina Almasry spin_unlock(&resv->lock); 4380db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 4390db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 4400db9d74eSMina Almasry if (!trg) 4410db9d74eSMina Almasry goto out_of_memory; 4420db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 4430db9d74eSMina Almasry } 4440db9d74eSMina Almasry 4450db9d74eSMina Almasry spin_lock(&resv->lock); 4460db9d74eSMina Almasry 447d3ec7b6eSWei Yang list_splice(&allocated_regions, &resv->region_cache); 448d3ec7b6eSWei Yang resv->region_cache_count += to_allocate; 4490db9d74eSMina Almasry } 4500db9d74eSMina Almasry 4510db9d74eSMina Almasry return 0; 4520db9d74eSMina Almasry 4530db9d74eSMina Almasry out_of_memory: 4540db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 455d75c6af9SMina Almasry list_del(&rg->link); 456d75c6af9SMina Almasry kfree(rg); 457d75c6af9SMina Almasry } 4580db9d74eSMina Almasry return -ENOMEM; 459d75c6af9SMina Almasry } 460d75c6af9SMina Almasry 4611dd308a7SMike Kravetz /* 4621dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 4630db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 4640db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 4650db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 4660db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 4670db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 468cf3ad20bSMike Kravetz * 4690db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 4700db9d74eSMina Almasry * 4710db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 4720db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 4737c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 4740db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 4750db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 4760db9d74eSMina Almasry * 1 page will only require at most 1 entry. 4771dd308a7SMike Kravetz */ 4780db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 479075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 480075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 48196822904SAndy Whitcroft { 4820db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 48396822904SAndy Whitcroft 4847b24d861SDavidlohr Bueso spin_lock(&resv->lock); 4850db9d74eSMina Almasry retry: 4860db9d74eSMina Almasry 4870db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 488972a3da3SWei Yang add_reservation_in_range(resv, f, t, NULL, NULL, 489972a3da3SWei Yang &actual_regions_needed); 49096822904SAndy Whitcroft 4915e911373SMike Kravetz /* 4920db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4930db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 4940db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 4950db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 4960db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 4970db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 4980db9d74eSMina Almasry * operation. 4995e911373SMike Kravetz */ 5000db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 5010db9d74eSMina Almasry resv->region_cache_count < 5020db9d74eSMina Almasry resv->adds_in_progress + 5030db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 5040db9d74eSMina Almasry /* region_add operation of range 1 should never need to 5050db9d74eSMina Almasry * allocate file_region entries. 5060db9d74eSMina Almasry */ 5070db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 5085e911373SMike Kravetz 5090db9d74eSMina Almasry if (allocate_file_region_entries( 5100db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 5110db9d74eSMina Almasry return -ENOMEM; 5125e911373SMike Kravetz } 5135e911373SMike Kravetz 5140db9d74eSMina Almasry goto retry; 5150db9d74eSMina Almasry } 516cf3ad20bSMike Kravetz 517972a3da3SWei Yang add = add_reservation_in_range(resv, f, t, h_cg, h, NULL); 5180db9d74eSMina Almasry 5190db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 5200db9d74eSMina Almasry 5217b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 522cf3ad20bSMike Kravetz VM_BUG_ON(add < 0); 523cf3ad20bSMike Kravetz return add; 52496822904SAndy Whitcroft } 52596822904SAndy Whitcroft 5261dd308a7SMike Kravetz /* 5271dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 5281dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 5291dd308a7SMike Kravetz * represented. This routine is called before a subsequent 5301dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 5311dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 5321dd308a7SMike Kravetz * not change the number of huge pages represented by the 5330db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 5340db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 5350db9d74eSMina Almasry * file_region structure is added. 5360db9d74eSMina Almasry * 5370db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 5380db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 5390db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 5405e911373SMike Kravetz * 5415e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 5425e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 5435e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 5445e911373SMike Kravetz * is needed and can not be allocated. 5451dd308a7SMike Kravetz */ 5460db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 5470db9d74eSMina Almasry long *out_regions_needed) 54896822904SAndy Whitcroft { 54996822904SAndy Whitcroft long chg = 0; 55096822904SAndy Whitcroft 5517b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5525e911373SMike Kravetz 553972a3da3SWei Yang /* Count how many hugepages in this range are NOT represented. */ 554075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 555972a3da3SWei Yang out_regions_needed); 5565e911373SMike Kravetz 5570db9d74eSMina Almasry if (*out_regions_needed == 0) 5580db9d74eSMina Almasry *out_regions_needed = 1; 5595e911373SMike Kravetz 5600db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 5615e911373SMike Kravetz return -ENOMEM; 5625e911373SMike Kravetz 5630db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 56496822904SAndy Whitcroft 5657b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 56696822904SAndy Whitcroft return chg; 56796822904SAndy Whitcroft } 56896822904SAndy Whitcroft 5691dd308a7SMike Kravetz /* 5705e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 5715e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 5725e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 5735e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 5740db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 5750db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 5760db9d74eSMina Almasry * the adds_in_progress counter. 5775e911373SMike Kravetz * 5785e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 5795e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 5805e911373SMike Kravetz * arguments will match the associated region_chg call. 5815e911373SMike Kravetz */ 5820db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 5830db9d74eSMina Almasry long regions_needed) 5845e911373SMike Kravetz { 5855e911373SMike Kravetz spin_lock(&resv->lock); 5865e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 5870db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 5885e911373SMike Kravetz spin_unlock(&resv->lock); 5895e911373SMike Kravetz } 5905e911373SMike Kravetz 5915e911373SMike Kravetz /* 592feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 593feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 594feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 595feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 596feba16e2SMike Kravetz * 597feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 598feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 599feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 600feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 601feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 602feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 603feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 6041dd308a7SMike Kravetz */ 605feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 60696822904SAndy Whitcroft { 6071406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 60896822904SAndy Whitcroft struct file_region *rg, *trg; 609feba16e2SMike Kravetz struct file_region *nrg = NULL; 610feba16e2SMike Kravetz long del = 0; 61196822904SAndy Whitcroft 612feba16e2SMike Kravetz retry: 6137b24d861SDavidlohr Bueso spin_lock(&resv->lock); 614feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 615dbe409e4SMike Kravetz /* 616dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 617dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 618dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 619dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 620dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 621dbe409e4SMike Kravetz */ 622dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 623feba16e2SMike Kravetz continue; 624dbe409e4SMike Kravetz 625feba16e2SMike Kravetz if (rg->from >= t) 62696822904SAndy Whitcroft break; 62796822904SAndy Whitcroft 628feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 629feba16e2SMike Kravetz /* 630feba16e2SMike Kravetz * Check for an entry in the cache before dropping 631feba16e2SMike Kravetz * lock and attempting allocation. 632feba16e2SMike Kravetz */ 633feba16e2SMike Kravetz if (!nrg && 634feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 635feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 636feba16e2SMike Kravetz struct file_region, 637feba16e2SMike Kravetz link); 638feba16e2SMike Kravetz list_del(&nrg->link); 639feba16e2SMike Kravetz resv->region_cache_count--; 64096822904SAndy Whitcroft } 64196822904SAndy Whitcroft 642feba16e2SMike Kravetz if (!nrg) { 643feba16e2SMike Kravetz spin_unlock(&resv->lock); 644feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 645feba16e2SMike Kravetz if (!nrg) 646feba16e2SMike Kravetz return -ENOMEM; 647feba16e2SMike Kravetz goto retry; 648feba16e2SMike Kravetz } 649feba16e2SMike Kravetz 650feba16e2SMike Kravetz del += t - f; 651feba16e2SMike Kravetz 652feba16e2SMike Kravetz /* New entry for end of split region */ 653feba16e2SMike Kravetz nrg->from = t; 654feba16e2SMike Kravetz nrg->to = rg->to; 655075a61d0SMina Almasry 656075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 657075a61d0SMina Almasry 658feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 659feba16e2SMike Kravetz 660feba16e2SMike Kravetz /* Original entry is trimmed */ 661feba16e2SMike Kravetz rg->to = f; 662feba16e2SMike Kravetz 663075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region( 664075a61d0SMina Almasry resv, rg, nrg->to - nrg->from); 665075a61d0SMina Almasry 666feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 667feba16e2SMike Kravetz nrg = NULL; 66896822904SAndy Whitcroft break; 669feba16e2SMike Kravetz } 670feba16e2SMike Kravetz 671feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 672feba16e2SMike Kravetz del += rg->to - rg->from; 673075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 674075a61d0SMina Almasry rg->to - rg->from); 67596822904SAndy Whitcroft list_del(&rg->link); 67696822904SAndy Whitcroft kfree(rg); 677feba16e2SMike Kravetz continue; 67896822904SAndy Whitcroft } 6797b24d861SDavidlohr Bueso 680feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 681feba16e2SMike Kravetz del += t - rg->from; 682feba16e2SMike Kravetz rg->from = t; 683075a61d0SMina Almasry 684075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 685075a61d0SMina Almasry t - rg->from); 686feba16e2SMike Kravetz } else { /* Trim end of region */ 687feba16e2SMike Kravetz del += rg->to - f; 688feba16e2SMike Kravetz rg->to = f; 689075a61d0SMina Almasry 690075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 691075a61d0SMina Almasry rg->to - f); 692feba16e2SMike Kravetz } 693feba16e2SMike Kravetz } 694feba16e2SMike Kravetz 6957b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 696feba16e2SMike Kravetz kfree(nrg); 697feba16e2SMike Kravetz return del; 69896822904SAndy Whitcroft } 69996822904SAndy Whitcroft 7001dd308a7SMike Kravetz /* 701b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 702b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 703b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 704b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 705b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 706b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 707b5cec28dSMike Kravetz * counts. 708b5cec28dSMike Kravetz */ 70972e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 710b5cec28dSMike Kravetz { 711b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 712b5cec28dSMike Kravetz long rsv_adjust; 713b5cec28dSMike Kravetz 714b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 71572e2936cSzhong jiang if (rsv_adjust) { 716b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 717b5cec28dSMike Kravetz 718b5cec28dSMike Kravetz hugetlb_acct_memory(h, 1); 719b5cec28dSMike Kravetz } 720b5cec28dSMike Kravetz } 721b5cec28dSMike Kravetz 722b5cec28dSMike Kravetz /* 7231dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 7241dd308a7SMike Kravetz * that intersect with the range [f, t). 7251dd308a7SMike Kravetz */ 7261406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 72784afd99bSAndy Whitcroft { 7281406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 72984afd99bSAndy Whitcroft struct file_region *rg; 73084afd99bSAndy Whitcroft long chg = 0; 73184afd99bSAndy Whitcroft 7327b24d861SDavidlohr Bueso spin_lock(&resv->lock); 73384afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 73484afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 735f2135a4aSWang Sheng-Hui long seg_from; 736f2135a4aSWang Sheng-Hui long seg_to; 73784afd99bSAndy Whitcroft 73884afd99bSAndy Whitcroft if (rg->to <= f) 73984afd99bSAndy Whitcroft continue; 74084afd99bSAndy Whitcroft if (rg->from >= t) 74184afd99bSAndy Whitcroft break; 74284afd99bSAndy Whitcroft 74384afd99bSAndy Whitcroft seg_from = max(rg->from, f); 74484afd99bSAndy Whitcroft seg_to = min(rg->to, t); 74584afd99bSAndy Whitcroft 74684afd99bSAndy Whitcroft chg += seg_to - seg_from; 74784afd99bSAndy Whitcroft } 7487b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 74984afd99bSAndy Whitcroft 75084afd99bSAndy Whitcroft return chg; 75184afd99bSAndy Whitcroft } 75284afd99bSAndy Whitcroft 75396822904SAndy Whitcroft /* 754e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 755e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 756e7c4b0bfSAndy Whitcroft */ 757a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 758a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 759e7c4b0bfSAndy Whitcroft { 760a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 761a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 762e7c4b0bfSAndy Whitcroft } 763e7c4b0bfSAndy Whitcroft 7640fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 7650fe6e20bSNaoya Horiguchi unsigned long address) 7660fe6e20bSNaoya Horiguchi { 7670fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 7680fe6e20bSNaoya Horiguchi } 769dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 7700fe6e20bSNaoya Horiguchi 77184afd99bSAndy Whitcroft /* 77208fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 77308fba699SMel Gorman * cases this will be same size as used by the page table entries. 77408fba699SMel Gorman */ 77508fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 77608fba699SMel Gorman { 77705ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 77805ea8860SDan Williams return vma->vm_ops->pagesize(vma); 77908fba699SMel Gorman return PAGE_SIZE; 78008fba699SMel Gorman } 781f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 78208fba699SMel Gorman 78308fba699SMel Gorman /* 7843340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 7853340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 78609135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 78709135cc5SDan Williams * version of this symbol is required. 7883340289dSMel Gorman */ 78909135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 7903340289dSMel Gorman { 7913340289dSMel Gorman return vma_kernel_pagesize(vma); 7923340289dSMel Gorman } 7933340289dSMel Gorman 7943340289dSMel Gorman /* 79584afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 79684afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 79784afd99bSAndy Whitcroft * alignment. 79884afd99bSAndy Whitcroft */ 79984afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 80084afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 80104f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 80284afd99bSAndy Whitcroft 803a1e78772SMel Gorman /* 804a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 805a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 806a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 807a1e78772SMel Gorman * 808a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 809a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 810a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 811a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 81284afd99bSAndy Whitcroft * 81384afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 81484afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 81584afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 81684afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 81784afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 81884afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 81984afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 82084afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 821a1e78772SMel Gorman */ 822e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 823e7c4b0bfSAndy Whitcroft { 824e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 825e7c4b0bfSAndy Whitcroft } 826e7c4b0bfSAndy Whitcroft 827e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 828e7c4b0bfSAndy Whitcroft unsigned long value) 829e7c4b0bfSAndy Whitcroft { 830e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 831e7c4b0bfSAndy Whitcroft } 832e7c4b0bfSAndy Whitcroft 833e9fe92aeSMina Almasry static void 834e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 835e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 836e9fe92aeSMina Almasry struct hstate *h) 837e9fe92aeSMina Almasry { 838e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 839e9fe92aeSMina Almasry if (!h_cg || !h) { 840e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 841e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 842e9fe92aeSMina Almasry resv_map->css = NULL; 843e9fe92aeSMina Almasry } else { 844e9fe92aeSMina Almasry resv_map->reservation_counter = 845e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 846e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 847e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 848e9fe92aeSMina Almasry } 849e9fe92aeSMina Almasry #endif 850e9fe92aeSMina Almasry } 851e9fe92aeSMina Almasry 8529119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 85384afd99bSAndy Whitcroft { 85484afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 8555e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 8565e911373SMike Kravetz 8575e911373SMike Kravetz if (!resv_map || !rg) { 8585e911373SMike Kravetz kfree(resv_map); 8595e911373SMike Kravetz kfree(rg); 86084afd99bSAndy Whitcroft return NULL; 8615e911373SMike Kravetz } 86284afd99bSAndy Whitcroft 86384afd99bSAndy Whitcroft kref_init(&resv_map->refs); 8647b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 86584afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 86684afd99bSAndy Whitcroft 8675e911373SMike Kravetz resv_map->adds_in_progress = 0; 868e9fe92aeSMina Almasry /* 869e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 870e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 871e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 872e9fe92aeSMina Almasry * reservations are to be un-charged from here. 873e9fe92aeSMina Almasry */ 874e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 8755e911373SMike Kravetz 8765e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 8775e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 8785e911373SMike Kravetz resv_map->region_cache_count = 1; 8795e911373SMike Kravetz 88084afd99bSAndy Whitcroft return resv_map; 88184afd99bSAndy Whitcroft } 88284afd99bSAndy Whitcroft 8839119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 88484afd99bSAndy Whitcroft { 88584afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 8865e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 8875e911373SMike Kravetz struct file_region *rg, *trg; 88884afd99bSAndy Whitcroft 88984afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 890feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 8915e911373SMike Kravetz 8925e911373SMike Kravetz /* ... and any entries left in the cache */ 8935e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 8945e911373SMike Kravetz list_del(&rg->link); 8955e911373SMike Kravetz kfree(rg); 8965e911373SMike Kravetz } 8975e911373SMike Kravetz 8985e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 8995e911373SMike Kravetz 90084afd99bSAndy Whitcroft kfree(resv_map); 90184afd99bSAndy Whitcroft } 90284afd99bSAndy Whitcroft 9034e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 9044e35f483SJoonsoo Kim { 905f27a5136SMike Kravetz /* 906f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 907f27a5136SMike Kravetz * address space within the inode. This original address space 908f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 909f27a5136SMike Kravetz * address space embedded within the inode. 910f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 911f27a5136SMike Kravetz * this may not be true for device special inodes. 912f27a5136SMike Kravetz */ 913f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 9144e35f483SJoonsoo Kim } 9154e35f483SJoonsoo Kim 91684afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 917a1e78772SMel Gorman { 91881d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 9194e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 9204e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 9214e35f483SJoonsoo Kim struct inode *inode = mapping->host; 9224e35f483SJoonsoo Kim 9234e35f483SJoonsoo Kim return inode_resv_map(inode); 9244e35f483SJoonsoo Kim 9254e35f483SJoonsoo Kim } else { 92684afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 92784afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 9284e35f483SJoonsoo Kim } 929a1e78772SMel Gorman } 930a1e78772SMel Gorman 93184afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 932a1e78772SMel Gorman { 93381d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 93481d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 935a1e78772SMel Gorman 93684afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 93784afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 93804f2cbe3SMel Gorman } 93904f2cbe3SMel Gorman 94004f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 94104f2cbe3SMel Gorman { 94281d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 94381d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 944e7c4b0bfSAndy Whitcroft 945e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 94604f2cbe3SMel Gorman } 94704f2cbe3SMel Gorman 94804f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 94904f2cbe3SMel Gorman { 95081d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 951e7c4b0bfSAndy Whitcroft 952e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 953a1e78772SMel Gorman } 954a1e78772SMel Gorman 95504f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 956a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 957a1e78772SMel Gorman { 95881d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 959f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 960a1e78772SMel Gorman vma->vm_private_data = (void *)0; 961a1e78772SMel Gorman } 962a1e78772SMel Gorman 963a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 964559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 965a1e78772SMel Gorman { 966af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 967af0ed73eSJoonsoo Kim /* 968af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 969af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 970af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 971af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 972af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 973af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 974af0ed73eSJoonsoo Kim * properly, so add work-around here. 975af0ed73eSJoonsoo Kim */ 976af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 977559ec2f8SNicholas Krause return true; 978af0ed73eSJoonsoo Kim else 979559ec2f8SNicholas Krause return false; 980af0ed73eSJoonsoo Kim } 981a63884e9SJoonsoo Kim 982a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 9831fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 9841fb1b0e9SMike Kravetz /* 9851fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 9861fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 9871fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 9887c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 9891fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 9901fb1b0e9SMike Kravetz */ 9911fb1b0e9SMike Kravetz if (chg) 9921fb1b0e9SMike Kravetz return false; 9931fb1b0e9SMike Kravetz else 994559ec2f8SNicholas Krause return true; 9951fb1b0e9SMike Kravetz } 996a63884e9SJoonsoo Kim 997a63884e9SJoonsoo Kim /* 998a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 999a63884e9SJoonsoo Kim * private mappings. 1000a63884e9SJoonsoo Kim */ 100167961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 100267961f9dSMike Kravetz /* 100367961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 100467961f9dSMike Kravetz * could have been performed on the private mapping. 100567961f9dSMike Kravetz * Examine the value of chg to determine if reserves 100667961f9dSMike Kravetz * actually exist or were previously consumed. 100767961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 100867961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 100967961f9dSMike Kravetz * private mappings has different (opposite) semantics 101067961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 101167961f9dSMike Kravetz * has already taken this difference in semantics into 101267961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 101367961f9dSMike Kravetz * as in the shared case above. Code could easily be 101467961f9dSMike Kravetz * combined, but keeping it separate draws attention to 101567961f9dSMike Kravetz * subtle differences. 101667961f9dSMike Kravetz */ 101767961f9dSMike Kravetz if (chg) 101867961f9dSMike Kravetz return false; 101967961f9dSMike Kravetz else 1020559ec2f8SNicholas Krause return true; 102167961f9dSMike Kravetz } 1022a63884e9SJoonsoo Kim 1023559ec2f8SNicholas Krause return false; 1024a1e78772SMel Gorman } 1025a1e78772SMel Gorman 1026a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 10271da177e4SLinus Torvalds { 10281da177e4SLinus Torvalds int nid = page_to_nid(page); 10290edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1030a5516438SAndi Kleen h->free_huge_pages++; 1031a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 10321da177e4SLinus Torvalds } 10331da177e4SLinus Torvalds 103494310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1035bf50bab2SNaoya Horiguchi { 1036bf50bab2SNaoya Horiguchi struct page *page; 1037bbe88753SJoonsoo Kim bool nocma = !!(current->flags & PF_MEMALLOC_NOCMA); 1038bf50bab2SNaoya Horiguchi 1039bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 1040bbe88753SJoonsoo Kim if (nocma && is_migrate_cma_page(page)) 1041bbe88753SJoonsoo Kim continue; 1042bbe88753SJoonsoo Kim 1043243abd5bSNaoya Horiguchi if (!PageHWPoison(page)) 1044c8721bbbSNaoya Horiguchi break; 1045bbe88753SJoonsoo Kim } 1046bbe88753SJoonsoo Kim 1047c8721bbbSNaoya Horiguchi /* 1048c8721bbbSNaoya Horiguchi * if 'non-isolated free hugepage' not found on the list, 1049c8721bbbSNaoya Horiguchi * the allocation fails. 1050c8721bbbSNaoya Horiguchi */ 1051c8721bbbSNaoya Horiguchi if (&h->hugepage_freelists[nid] == &page->lru) 1052bf50bab2SNaoya Horiguchi return NULL; 10530edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1054a9869b83SNaoya Horiguchi set_page_refcounted(page); 1055bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1056bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1057bf50bab2SNaoya Horiguchi return page; 1058bf50bab2SNaoya Horiguchi } 1059bf50bab2SNaoya Horiguchi 10603e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 10613e59fcb0SMichal Hocko nodemask_t *nmask) 106294310cbcSAnshuman Khandual { 10633e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 10643e59fcb0SMichal Hocko struct zonelist *zonelist; 10653e59fcb0SMichal Hocko struct zone *zone; 10663e59fcb0SMichal Hocko struct zoneref *z; 106798fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 10683e59fcb0SMichal Hocko 10693e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 10703e59fcb0SMichal Hocko 10713e59fcb0SMichal Hocko retry_cpuset: 10723e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 10733e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 107494310cbcSAnshuman Khandual struct page *page; 107594310cbcSAnshuman Khandual 10763e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 10773e59fcb0SMichal Hocko continue; 10783e59fcb0SMichal Hocko /* 10793e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 10803e59fcb0SMichal Hocko * zone aware 10813e59fcb0SMichal Hocko */ 10823e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 10833e59fcb0SMichal Hocko continue; 10843e59fcb0SMichal Hocko node = zone_to_nid(zone); 108594310cbcSAnshuman Khandual 108694310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 108794310cbcSAnshuman Khandual if (page) 108894310cbcSAnshuman Khandual return page; 108994310cbcSAnshuman Khandual } 10903e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 10913e59fcb0SMichal Hocko goto retry_cpuset; 10923e59fcb0SMichal Hocko 109394310cbcSAnshuman Khandual return NULL; 109494310cbcSAnshuman Khandual } 109594310cbcSAnshuman Khandual 1096a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1097a5516438SAndi Kleen struct vm_area_struct *vma, 1098af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1099af0ed73eSJoonsoo Kim long chg) 11001da177e4SLinus Torvalds { 11013e59fcb0SMichal Hocko struct page *page; 1102480eccf9SLee Schermerhorn struct mempolicy *mpol; 110304ec6264SVlastimil Babka gfp_t gfp_mask; 11043e59fcb0SMichal Hocko nodemask_t *nodemask; 110504ec6264SVlastimil Babka int nid; 11061da177e4SLinus Torvalds 1107a1e78772SMel Gorman /* 1108a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1109a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1110a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1111a1e78772SMel Gorman */ 1112af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1113a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1114c0ff7453SMiao Xie goto err; 1115a1e78772SMel Gorman 111604f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1117a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 11186eab04a8SJustin P. Mattock goto err; 111904f2cbe3SMel Gorman 112004ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 112104ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 11223e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 11233e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 112407443a85SJoonsoo Kim SetPagePrivate(page); 1125a63884e9SJoonsoo Kim h->resv_huge_pages--; 1126bf50bab2SNaoya Horiguchi } 1127cc9a6c87SMel Gorman 1128cc9a6c87SMel Gorman mpol_cond_put(mpol); 1129cc9a6c87SMel Gorman return page; 1130cc9a6c87SMel Gorman 1131c0ff7453SMiao Xie err: 1132cc9a6c87SMel Gorman return NULL; 11331da177e4SLinus Torvalds } 11341da177e4SLinus Torvalds 11351cac6f2cSLuiz Capitulino /* 11361cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 11371cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 11381cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 11391cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 11401cac6f2cSLuiz Capitulino * node for alloc or free. 11411cac6f2cSLuiz Capitulino */ 11421cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 11431cac6f2cSLuiz Capitulino { 11440edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 11451cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 11461cac6f2cSLuiz Capitulino 11471cac6f2cSLuiz Capitulino return nid; 11481cac6f2cSLuiz Capitulino } 11491cac6f2cSLuiz Capitulino 11501cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 11511cac6f2cSLuiz Capitulino { 11521cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 11531cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 11541cac6f2cSLuiz Capitulino return nid; 11551cac6f2cSLuiz Capitulino } 11561cac6f2cSLuiz Capitulino 11571cac6f2cSLuiz Capitulino /* 11581cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 11591cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 11601cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 11611cac6f2cSLuiz Capitulino * mask. 11621cac6f2cSLuiz Capitulino */ 11631cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 11641cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 11651cac6f2cSLuiz Capitulino { 11661cac6f2cSLuiz Capitulino int nid; 11671cac6f2cSLuiz Capitulino 11681cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 11691cac6f2cSLuiz Capitulino 11701cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 11711cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 11721cac6f2cSLuiz Capitulino 11731cac6f2cSLuiz Capitulino return nid; 11741cac6f2cSLuiz Capitulino } 11751cac6f2cSLuiz Capitulino 11761cac6f2cSLuiz Capitulino /* 11771cac6f2cSLuiz Capitulino * helper for free_pool_huge_page() - return the previously saved 11781cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 11791cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 11801cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 11811cac6f2cSLuiz Capitulino */ 11821cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 11831cac6f2cSLuiz Capitulino { 11841cac6f2cSLuiz Capitulino int nid; 11851cac6f2cSLuiz Capitulino 11861cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 11871cac6f2cSLuiz Capitulino 11881cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 11891cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 11901cac6f2cSLuiz Capitulino 11911cac6f2cSLuiz Capitulino return nid; 11921cac6f2cSLuiz Capitulino } 11931cac6f2cSLuiz Capitulino 11941cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 11951cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 11961cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 11971cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 11981cac6f2cSLuiz Capitulino nr_nodes--) 11991cac6f2cSLuiz Capitulino 12001cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 12011cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12021cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12031cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 12041cac6f2cSLuiz Capitulino nr_nodes--) 12051cac6f2cSLuiz Capitulino 1206e1073d1eSAneesh Kumar K.V #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 1207944d9fecSLuiz Capitulino static void destroy_compound_gigantic_page(struct page *page, 1208d00181b9SKirill A. Shutemov unsigned int order) 1209944d9fecSLuiz Capitulino { 1210944d9fecSLuiz Capitulino int i; 1211944d9fecSLuiz Capitulino int nr_pages = 1 << order; 1212944d9fecSLuiz Capitulino struct page *p = page + 1; 1213944d9fecSLuiz Capitulino 1214c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 121547e29d32SJohn Hubbard if (hpage_pincount_available(page)) 121647e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 121747e29d32SJohn Hubbard 1218944d9fecSLuiz Capitulino for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 12191d798ca3SKirill A. Shutemov clear_compound_head(p); 1220944d9fecSLuiz Capitulino set_page_refcounted(p); 1221944d9fecSLuiz Capitulino } 1222944d9fecSLuiz Capitulino 1223944d9fecSLuiz Capitulino set_compound_order(page, 0); 1224944d9fecSLuiz Capitulino __ClearPageHead(page); 1225944d9fecSLuiz Capitulino } 1226944d9fecSLuiz Capitulino 1227d00181b9SKirill A. Shutemov static void free_gigantic_page(struct page *page, unsigned int order) 1228944d9fecSLuiz Capitulino { 1229cf11e85fSRoman Gushchin /* 1230cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1231cf11e85fSRoman Gushchin * cma_release() returns false. 1232cf11e85fSRoman Gushchin */ 1233dbda8feaSBarry Song #ifdef CONFIG_CMA 1234dbda8feaSBarry Song if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)) 1235cf11e85fSRoman Gushchin return; 1236dbda8feaSBarry Song #endif 1237cf11e85fSRoman Gushchin 1238944d9fecSLuiz Capitulino free_contig_range(page_to_pfn(page), 1 << order); 1239944d9fecSLuiz Capitulino } 1240944d9fecSLuiz Capitulino 12414eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 1242d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 1243d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1244944d9fecSLuiz Capitulino { 12455e27a2dfSAnshuman Khandual unsigned long nr_pages = 1UL << huge_page_order(h); 1246953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1247953f064aSLi Xinhai nid = numa_mem_id(); 1248944d9fecSLuiz Capitulino 1249dbda8feaSBarry Song #ifdef CONFIG_CMA 1250dbda8feaSBarry Song { 1251cf11e85fSRoman Gushchin struct page *page; 1252cf11e85fSRoman Gushchin int node; 1253cf11e85fSRoman Gushchin 1254953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1255953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1256953f064aSLi Xinhai huge_page_order(h), true); 1257953f064aSLi Xinhai if (page) 1258953f064aSLi Xinhai return page; 1259953f064aSLi Xinhai } 1260953f064aSLi Xinhai 1261953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1262cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1263953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1264cf11e85fSRoman Gushchin continue; 1265cf11e85fSRoman Gushchin 1266cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1267cf11e85fSRoman Gushchin huge_page_order(h), true); 1268cf11e85fSRoman Gushchin if (page) 1269cf11e85fSRoman Gushchin return page; 1270cf11e85fSRoman Gushchin } 1271cf11e85fSRoman Gushchin } 1272953f064aSLi Xinhai } 1273dbda8feaSBarry Song #endif 1274cf11e85fSRoman Gushchin 12755e27a2dfSAnshuman Khandual return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 1276944d9fecSLuiz Capitulino } 1277944d9fecSLuiz Capitulino 1278944d9fecSLuiz Capitulino static void prep_new_huge_page(struct hstate *h, struct page *page, int nid); 1279d00181b9SKirill A. Shutemov static void prep_compound_gigantic_page(struct page *page, unsigned int order); 12804eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 12814eb0716eSAlexandre Ghiti static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 12824eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 12834eb0716eSAlexandre Ghiti { 12844eb0716eSAlexandre Ghiti return NULL; 12854eb0716eSAlexandre Ghiti } 12864eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1287944d9fecSLuiz Capitulino 1288e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 1289d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 12904eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 12914eb0716eSAlexandre Ghiti { 12924eb0716eSAlexandre Ghiti return NULL; 12934eb0716eSAlexandre Ghiti } 1294d00181b9SKirill A. Shutemov static inline void free_gigantic_page(struct page *page, unsigned int order) { } 1295944d9fecSLuiz Capitulino static inline void destroy_compound_gigantic_page(struct page *page, 1296d00181b9SKirill A. Shutemov unsigned int order) { } 1297944d9fecSLuiz Capitulino #endif 1298944d9fecSLuiz Capitulino 1299a5516438SAndi Kleen static void update_and_free_page(struct hstate *h, struct page *page) 13006af2acb6SAdam Litke { 13016af2acb6SAdam Litke int i; 1302a5516438SAndi Kleen 13034eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1304944d9fecSLuiz Capitulino return; 130518229df5SAndy Whitcroft 1306a5516438SAndi Kleen h->nr_huge_pages--; 1307a5516438SAndi Kleen h->nr_huge_pages_node[page_to_nid(page)]--; 1308a5516438SAndi Kleen for (i = 0; i < pages_per_huge_page(h); i++) { 130932f84528SChris Forbes page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 131032f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1311a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1312a7407a27SLuiz Capitulino 1 << PG_writeback); 13136af2acb6SAdam Litke } 1314309381feSSasha Levin VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); 13151adc4d41SMina Almasry VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); 1316f1e61557SKirill A. Shutemov set_compound_page_dtor(page, NULL_COMPOUND_DTOR); 13176af2acb6SAdam Litke set_page_refcounted(page); 1318944d9fecSLuiz Capitulino if (hstate_is_gigantic(h)) { 1319cf11e85fSRoman Gushchin /* 1320cf11e85fSRoman Gushchin * Temporarily drop the hugetlb_lock, because 1321cf11e85fSRoman Gushchin * we might block in free_gigantic_page(). 1322cf11e85fSRoman Gushchin */ 1323cf11e85fSRoman Gushchin spin_unlock(&hugetlb_lock); 1324944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1325944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1326cf11e85fSRoman Gushchin spin_lock(&hugetlb_lock); 1327944d9fecSLuiz Capitulino } else { 1328a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 13296af2acb6SAdam Litke } 1330944d9fecSLuiz Capitulino } 13316af2acb6SAdam Litke 1332e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1333e5ff2159SAndi Kleen { 1334e5ff2159SAndi Kleen struct hstate *h; 1335e5ff2159SAndi Kleen 1336e5ff2159SAndi Kleen for_each_hstate(h) { 1337e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1338e5ff2159SAndi Kleen return h; 1339e5ff2159SAndi Kleen } 1340e5ff2159SAndi Kleen return NULL; 1341e5ff2159SAndi Kleen } 1342e5ff2159SAndi Kleen 1343bcc54222SNaoya Horiguchi /* 1344bcc54222SNaoya Horiguchi * Test to determine whether the hugepage is "active/in-use" (i.e. being linked 1345bcc54222SNaoya Horiguchi * to hstate->hugepage_activelist.) 1346bcc54222SNaoya Horiguchi * 1347bcc54222SNaoya Horiguchi * This function can be called for tail pages, but never returns true for them. 1348bcc54222SNaoya Horiguchi */ 1349bcc54222SNaoya Horiguchi bool page_huge_active(struct page *page) 1350bcc54222SNaoya Horiguchi { 1351bcc54222SNaoya Horiguchi VM_BUG_ON_PAGE(!PageHuge(page), page); 1352bcc54222SNaoya Horiguchi return PageHead(page) && PagePrivate(&page[1]); 1353bcc54222SNaoya Horiguchi } 1354bcc54222SNaoya Horiguchi 1355bcc54222SNaoya Horiguchi /* never called for tail page */ 1356bcc54222SNaoya Horiguchi static void set_page_huge_active(struct page *page) 1357bcc54222SNaoya Horiguchi { 1358bcc54222SNaoya Horiguchi VM_BUG_ON_PAGE(!PageHeadHuge(page), page); 1359bcc54222SNaoya Horiguchi SetPagePrivate(&page[1]); 1360bcc54222SNaoya Horiguchi } 1361bcc54222SNaoya Horiguchi 1362bcc54222SNaoya Horiguchi static void clear_page_huge_active(struct page *page) 1363bcc54222SNaoya Horiguchi { 1364bcc54222SNaoya Horiguchi VM_BUG_ON_PAGE(!PageHeadHuge(page), page); 1365bcc54222SNaoya Horiguchi ClearPagePrivate(&page[1]); 1366bcc54222SNaoya Horiguchi } 1367bcc54222SNaoya Horiguchi 1368ab5ac90aSMichal Hocko /* 1369ab5ac90aSMichal Hocko * Internal hugetlb specific page flag. Do not use outside of the hugetlb 1370ab5ac90aSMichal Hocko * code 1371ab5ac90aSMichal Hocko */ 1372ab5ac90aSMichal Hocko static inline bool PageHugeTemporary(struct page *page) 1373ab5ac90aSMichal Hocko { 1374ab5ac90aSMichal Hocko if (!PageHuge(page)) 1375ab5ac90aSMichal Hocko return false; 1376ab5ac90aSMichal Hocko 1377ab5ac90aSMichal Hocko return (unsigned long)page[2].mapping == -1U; 1378ab5ac90aSMichal Hocko } 1379ab5ac90aSMichal Hocko 1380ab5ac90aSMichal Hocko static inline void SetPageHugeTemporary(struct page *page) 1381ab5ac90aSMichal Hocko { 1382ab5ac90aSMichal Hocko page[2].mapping = (void *)-1U; 1383ab5ac90aSMichal Hocko } 1384ab5ac90aSMichal Hocko 1385ab5ac90aSMichal Hocko static inline void ClearPageHugeTemporary(struct page *page) 1386ab5ac90aSMichal Hocko { 1387ab5ac90aSMichal Hocko page[2].mapping = NULL; 1388ab5ac90aSMichal Hocko } 1389ab5ac90aSMichal Hocko 1390c77c0a8aSWaiman Long static void __free_huge_page(struct page *page) 139127a85ef1SDavid Gibson { 1392a5516438SAndi Kleen /* 1393a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1394a5516438SAndi Kleen * compound page destructor. 1395a5516438SAndi Kleen */ 1396e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 13977893d1d5SAdam Litke int nid = page_to_nid(page); 139890481622SDavid Gibson struct hugepage_subpool *spool = 139990481622SDavid Gibson (struct hugepage_subpool *)page_private(page); 140007443a85SJoonsoo Kim bool restore_reserve; 140127a85ef1SDavid Gibson 1402b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1403b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 14048ace22bcSYongkai Wu 14058ace22bcSYongkai Wu set_page_private(page, 0); 14068ace22bcSYongkai Wu page->mapping = NULL; 140707443a85SJoonsoo Kim restore_reserve = PagePrivate(page); 140816c794b4SJoonsoo Kim ClearPagePrivate(page); 140927a85ef1SDavid Gibson 14101c5ecae3SMike Kravetz /* 14110919e1b6SMike Kravetz * If PagePrivate() was set on page, page allocation consumed a 14120919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 14130919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 14140919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 14150919e1b6SMike Kravetz * reservtion, do not call hugepage_subpool_put_pages() as this will 14160919e1b6SMike Kravetz * remove the reserved page from the subpool. 14170919e1b6SMike Kravetz */ 14180919e1b6SMike Kravetz if (!restore_reserve) { 14190919e1b6SMike Kravetz /* 14200919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 14210919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 14220919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 14230919e1b6SMike Kravetz * operation. 14241c5ecae3SMike Kravetz */ 14251c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 14261c5ecae3SMike Kravetz restore_reserve = true; 14270919e1b6SMike Kravetz } 14281c5ecae3SMike Kravetz 142927a85ef1SDavid Gibson spin_lock(&hugetlb_lock); 1430bcc54222SNaoya Horiguchi clear_page_huge_active(page); 14316d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 14326d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 143308cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 143408cf9fafSMina Almasry pages_per_huge_page(h), page); 143507443a85SJoonsoo Kim if (restore_reserve) 143607443a85SJoonsoo Kim h->resv_huge_pages++; 143707443a85SJoonsoo Kim 1438ab5ac90aSMichal Hocko if (PageHugeTemporary(page)) { 1439ab5ac90aSMichal Hocko list_del(&page->lru); 1440ab5ac90aSMichal Hocko ClearPageHugeTemporary(page); 1441ab5ac90aSMichal Hocko update_and_free_page(h, page); 1442ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 14430edaecfaSAneesh Kumar K.V /* remove the page from active list */ 14440edaecfaSAneesh Kumar K.V list_del(&page->lru); 1445a5516438SAndi Kleen update_and_free_page(h, page); 1446a5516438SAndi Kleen h->surplus_huge_pages--; 1447a5516438SAndi Kleen h->surplus_huge_pages_node[nid]--; 14487893d1d5SAdam Litke } else { 14495d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1450a5516438SAndi Kleen enqueue_huge_page(h, page); 14517893d1d5SAdam Litke } 145227a85ef1SDavid Gibson spin_unlock(&hugetlb_lock); 145327a85ef1SDavid Gibson } 145427a85ef1SDavid Gibson 1455c77c0a8aSWaiman Long /* 1456c77c0a8aSWaiman Long * As free_huge_page() can be called from a non-task context, we have 1457c77c0a8aSWaiman Long * to defer the actual freeing in a workqueue to prevent potential 1458c77c0a8aSWaiman Long * hugetlb_lock deadlock. 1459c77c0a8aSWaiman Long * 1460c77c0a8aSWaiman Long * free_hpage_workfn() locklessly retrieves the linked list of pages to 1461c77c0a8aSWaiman Long * be freed and frees them one-by-one. As the page->mapping pointer is 1462c77c0a8aSWaiman Long * going to be cleared in __free_huge_page() anyway, it is reused as the 1463c77c0a8aSWaiman Long * llist_node structure of a lockless linked list of huge pages to be freed. 1464c77c0a8aSWaiman Long */ 1465c77c0a8aSWaiman Long static LLIST_HEAD(hpage_freelist); 1466c77c0a8aSWaiman Long 1467c77c0a8aSWaiman Long static void free_hpage_workfn(struct work_struct *work) 1468c77c0a8aSWaiman Long { 1469c77c0a8aSWaiman Long struct llist_node *node; 1470c77c0a8aSWaiman Long struct page *page; 1471c77c0a8aSWaiman Long 1472c77c0a8aSWaiman Long node = llist_del_all(&hpage_freelist); 1473c77c0a8aSWaiman Long 1474c77c0a8aSWaiman Long while (node) { 1475c77c0a8aSWaiman Long page = container_of((struct address_space **)node, 1476c77c0a8aSWaiman Long struct page, mapping); 1477c77c0a8aSWaiman Long node = node->next; 1478c77c0a8aSWaiman Long __free_huge_page(page); 1479c77c0a8aSWaiman Long } 1480c77c0a8aSWaiman Long } 1481c77c0a8aSWaiman Long static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1482c77c0a8aSWaiman Long 1483c77c0a8aSWaiman Long void free_huge_page(struct page *page) 1484c77c0a8aSWaiman Long { 1485c77c0a8aSWaiman Long /* 1486c77c0a8aSWaiman Long * Defer freeing if in non-task context to avoid hugetlb_lock deadlock. 1487c77c0a8aSWaiman Long */ 1488c77c0a8aSWaiman Long if (!in_task()) { 1489c77c0a8aSWaiman Long /* 1490c77c0a8aSWaiman Long * Only call schedule_work() if hpage_freelist is previously 1491c77c0a8aSWaiman Long * empty. Otherwise, schedule_work() had been called but the 1492c77c0a8aSWaiman Long * workfn hasn't retrieved the list yet. 1493c77c0a8aSWaiman Long */ 1494c77c0a8aSWaiman Long if (llist_add((struct llist_node *)&page->mapping, 1495c77c0a8aSWaiman Long &hpage_freelist)) 1496c77c0a8aSWaiman Long schedule_work(&free_hpage_work); 1497c77c0a8aSWaiman Long return; 1498c77c0a8aSWaiman Long } 1499c77c0a8aSWaiman Long 1500c77c0a8aSWaiman Long __free_huge_page(page); 1501c77c0a8aSWaiman Long } 1502c77c0a8aSWaiman Long 1503a5516438SAndi Kleen static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1504b7ba30c6SAndi Kleen { 15050edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1506f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1507b7ba30c6SAndi Kleen spin_lock(&hugetlb_lock); 15089dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 15091adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 1510a5516438SAndi Kleen h->nr_huge_pages++; 1511a5516438SAndi Kleen h->nr_huge_pages_node[nid]++; 1512b7ba30c6SAndi Kleen spin_unlock(&hugetlb_lock); 1513b7ba30c6SAndi Kleen } 1514b7ba30c6SAndi Kleen 1515d00181b9SKirill A. Shutemov static void prep_compound_gigantic_page(struct page *page, unsigned int order) 151620a0307cSWu Fengguang { 151720a0307cSWu Fengguang int i; 151820a0307cSWu Fengguang int nr_pages = 1 << order; 151920a0307cSWu Fengguang struct page *p = page + 1; 152020a0307cSWu Fengguang 152120a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 152220a0307cSWu Fengguang set_compound_order(page, order); 1523ef5a22beSAndrea Arcangeli __ClearPageReserved(page); 1524de09d31dSKirill A. Shutemov __SetPageHead(page); 152520a0307cSWu Fengguang for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1526ef5a22beSAndrea Arcangeli /* 1527ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1528ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1529ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 15307c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1531ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1532ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1533ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1534ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1535ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1536ef5a22beSAndrea Arcangeli * after get_user_pages(). 1537ef5a22beSAndrea Arcangeli */ 1538ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 153958a84aa9SYouquan Song set_page_count(p, 0); 15401d798ca3SKirill A. Shutemov set_compound_head(p, page); 154120a0307cSWu Fengguang } 1542b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 154347e29d32SJohn Hubbard 154447e29d32SJohn Hubbard if (hpage_pincount_available(page)) 154547e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 154620a0307cSWu Fengguang } 154720a0307cSWu Fengguang 15487795912cSAndrew Morton /* 15497795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 15507795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 15517795912cSAndrew Morton * details. 15527795912cSAndrew Morton */ 155320a0307cSWu Fengguang int PageHuge(struct page *page) 155420a0307cSWu Fengguang { 155520a0307cSWu Fengguang if (!PageCompound(page)) 155620a0307cSWu Fengguang return 0; 155720a0307cSWu Fengguang 155820a0307cSWu Fengguang page = compound_head(page); 1559f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 156020a0307cSWu Fengguang } 156143131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 156243131e14SNaoya Horiguchi 156327c73ae7SAndrea Arcangeli /* 156427c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 156527c73ae7SAndrea Arcangeli * normal or transparent huge pages. 156627c73ae7SAndrea Arcangeli */ 156727c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 156827c73ae7SAndrea Arcangeli { 156927c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 157027c73ae7SAndrea Arcangeli return 0; 157127c73ae7SAndrea Arcangeli 1572d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 157327c73ae7SAndrea Arcangeli } 157427c73ae7SAndrea Arcangeli 1575c0d0381aSMike Kravetz /* 1576c0d0381aSMike Kravetz * Find address_space associated with hugetlbfs page. 1577c0d0381aSMike Kravetz * Upon entry page is locked and page 'was' mapped although mapped state 1578c0d0381aSMike Kravetz * could change. If necessary, use anon_vma to find vma and associated 1579c0d0381aSMike Kravetz * address space. The returned mapping may be stale, but it can not be 1580c0d0381aSMike Kravetz * invalid as page lock (which is held) is required to destroy mapping. 1581c0d0381aSMike Kravetz */ 1582c0d0381aSMike Kravetz static struct address_space *_get_hugetlb_page_mapping(struct page *hpage) 1583c0d0381aSMike Kravetz { 1584c0d0381aSMike Kravetz struct anon_vma *anon_vma; 1585c0d0381aSMike Kravetz pgoff_t pgoff_start, pgoff_end; 1586c0d0381aSMike Kravetz struct anon_vma_chain *avc; 1587c0d0381aSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1588c0d0381aSMike Kravetz 1589c0d0381aSMike Kravetz /* Simple file based mapping */ 1590c0d0381aSMike Kravetz if (mapping) 1591c0d0381aSMike Kravetz return mapping; 1592c0d0381aSMike Kravetz 1593c0d0381aSMike Kravetz /* 1594c0d0381aSMike Kravetz * Even anonymous hugetlbfs mappings are associated with an 1595c0d0381aSMike Kravetz * underlying hugetlbfs file (see hugetlb_file_setup in mmap 1596c0d0381aSMike Kravetz * code). Find a vma associated with the anonymous vma, and 1597c0d0381aSMike Kravetz * use the file pointer to get address_space. 1598c0d0381aSMike Kravetz */ 1599c0d0381aSMike Kravetz anon_vma = page_lock_anon_vma_read(hpage); 1600c0d0381aSMike Kravetz if (!anon_vma) 1601c0d0381aSMike Kravetz return mapping; /* NULL */ 1602c0d0381aSMike Kravetz 1603c0d0381aSMike Kravetz /* Use first found vma */ 1604c0d0381aSMike Kravetz pgoff_start = page_to_pgoff(hpage); 16051139d336SMike Kravetz pgoff_end = pgoff_start + pages_per_huge_page(page_hstate(hpage)) - 1; 1606c0d0381aSMike Kravetz anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, 1607c0d0381aSMike Kravetz pgoff_start, pgoff_end) { 1608c0d0381aSMike Kravetz struct vm_area_struct *vma = avc->vma; 1609c0d0381aSMike Kravetz 1610c0d0381aSMike Kravetz mapping = vma->vm_file->f_mapping; 1611c0d0381aSMike Kravetz break; 1612c0d0381aSMike Kravetz } 1613c0d0381aSMike Kravetz 1614c0d0381aSMike Kravetz anon_vma_unlock_read(anon_vma); 1615c0d0381aSMike Kravetz return mapping; 1616c0d0381aSMike Kravetz } 1617c0d0381aSMike Kravetz 1618c0d0381aSMike Kravetz /* 1619c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1620c0d0381aSMike Kravetz * 1621c0d0381aSMike Kravetz * Upon entry, the page is locked which allows us to find the mapping 1622c0d0381aSMike Kravetz * even in the case of an anon page. However, locking order dictates 1623c0d0381aSMike Kravetz * the i_mmap_rwsem be acquired BEFORE the page lock. This is hugetlbfs 1624c0d0381aSMike Kravetz * specific. So, we first try to lock the sema while still holding the 1625c0d0381aSMike Kravetz * page lock. If this works, great! If not, then we need to drop the 1626c0d0381aSMike Kravetz * page lock and then acquire i_mmap_rwsem and reacquire page lock. Of 1627c0d0381aSMike Kravetz * course, need to revalidate state along the way. 1628c0d0381aSMike Kravetz */ 1629c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1630c0d0381aSMike Kravetz { 1631c0d0381aSMike Kravetz struct address_space *mapping, *mapping2; 1632c0d0381aSMike Kravetz 1633c0d0381aSMike Kravetz mapping = _get_hugetlb_page_mapping(hpage); 1634c0d0381aSMike Kravetz retry: 1635c0d0381aSMike Kravetz if (!mapping) 1636c0d0381aSMike Kravetz return mapping; 1637c0d0381aSMike Kravetz 1638c0d0381aSMike Kravetz /* 1639c0d0381aSMike Kravetz * If no contention, take lock and return 1640c0d0381aSMike Kravetz */ 1641c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1642c0d0381aSMike Kravetz return mapping; 1643c0d0381aSMike Kravetz 1644c0d0381aSMike Kravetz /* 1645c0d0381aSMike Kravetz * Must drop page lock and wait on mapping sema. 1646c0d0381aSMike Kravetz * Note: Once page lock is dropped, mapping could become invalid. 1647c0d0381aSMike Kravetz * As a hack, increase map count until we lock page again. 1648c0d0381aSMike Kravetz */ 1649c0d0381aSMike Kravetz atomic_inc(&hpage->_mapcount); 1650c0d0381aSMike Kravetz unlock_page(hpage); 1651c0d0381aSMike Kravetz i_mmap_lock_write(mapping); 1652c0d0381aSMike Kravetz lock_page(hpage); 1653c0d0381aSMike Kravetz atomic_add_negative(-1, &hpage->_mapcount); 1654c0d0381aSMike Kravetz 1655c0d0381aSMike Kravetz /* verify page is still mapped */ 1656c0d0381aSMike Kravetz if (!page_mapped(hpage)) { 1657c0d0381aSMike Kravetz i_mmap_unlock_write(mapping); 1658c0d0381aSMike Kravetz return NULL; 1659c0d0381aSMike Kravetz } 1660c0d0381aSMike Kravetz 1661c0d0381aSMike Kravetz /* 1662c0d0381aSMike Kravetz * Get address space again and verify it is the same one 1663c0d0381aSMike Kravetz * we locked. If not, drop lock and retry. 1664c0d0381aSMike Kravetz */ 1665c0d0381aSMike Kravetz mapping2 = _get_hugetlb_page_mapping(hpage); 1666c0d0381aSMike Kravetz if (mapping2 != mapping) { 1667c0d0381aSMike Kravetz i_mmap_unlock_write(mapping); 1668c0d0381aSMike Kravetz mapping = mapping2; 1669c0d0381aSMike Kravetz goto retry; 1670c0d0381aSMike Kravetz } 1671c0d0381aSMike Kravetz 1672c0d0381aSMike Kravetz return mapping; 1673c0d0381aSMike Kravetz } 1674c0d0381aSMike Kravetz 167513d60f4bSZhang Yi pgoff_t __basepage_index(struct page *page) 167613d60f4bSZhang Yi { 167713d60f4bSZhang Yi struct page *page_head = compound_head(page); 167813d60f4bSZhang Yi pgoff_t index = page_index(page_head); 167913d60f4bSZhang Yi unsigned long compound_idx; 168013d60f4bSZhang Yi 168113d60f4bSZhang Yi if (!PageHuge(page_head)) 168213d60f4bSZhang Yi return page_index(page); 168313d60f4bSZhang Yi 168413d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 168513d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 168613d60f4bSZhang Yi else 168713d60f4bSZhang Yi compound_idx = page - page_head; 168813d60f4bSZhang Yi 168913d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 169013d60f4bSZhang Yi } 169113d60f4bSZhang Yi 16920c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1693f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1694f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 16951da177e4SLinus Torvalds { 1696af0fb9dfSMichal Hocko int order = huge_page_order(h); 16971da177e4SLinus Torvalds struct page *page; 1698f60858f9SMike Kravetz bool alloc_try_hard = true; 1699f96efd58SJoe Jin 1700f60858f9SMike Kravetz /* 1701f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1702f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1703f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1704f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1705f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1706f60858f9SMike Kravetz */ 1707f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1708f60858f9SMike Kravetz alloc_try_hard = false; 1709f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1710f60858f9SMike Kravetz if (alloc_try_hard) 1711f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1712af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1713af0fb9dfSMichal Hocko nid = numa_mem_id(); 1714af0fb9dfSMichal Hocko page = __alloc_pages_nodemask(gfp_mask, order, nid, nmask); 1715af0fb9dfSMichal Hocko if (page) 1716af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1717af0fb9dfSMichal Hocko else 1718af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 171963b4613cSNishanth Aravamudan 1720f60858f9SMike Kravetz /* 1721f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1722f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1723f60858f9SMike Kravetz * normal 'try hard' allocations. 1724f60858f9SMike Kravetz */ 1725f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1726f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1727f60858f9SMike Kravetz 1728f60858f9SMike Kravetz /* 1729f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1730f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1731f60858f9SMike Kravetz * overall state change. 1732f60858f9SMike Kravetz */ 1733f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1734f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1735f60858f9SMike Kravetz 173663b4613cSNishanth Aravamudan return page; 173763b4613cSNishanth Aravamudan } 173863b4613cSNishanth Aravamudan 1739af0fb9dfSMichal Hocko /* 17400c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 17410c397daeSMichal Hocko * should use this function to get new hugetlb pages 17420c397daeSMichal Hocko */ 17430c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 1744f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1745f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 17460c397daeSMichal Hocko { 17470c397daeSMichal Hocko struct page *page; 17480c397daeSMichal Hocko 17490c397daeSMichal Hocko if (hstate_is_gigantic(h)) 17500c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 17510c397daeSMichal Hocko else 17520c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 1753f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 17540c397daeSMichal Hocko if (!page) 17550c397daeSMichal Hocko return NULL; 17560c397daeSMichal Hocko 17570c397daeSMichal Hocko if (hstate_is_gigantic(h)) 17580c397daeSMichal Hocko prep_compound_gigantic_page(page, huge_page_order(h)); 17590c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 17600c397daeSMichal Hocko 17610c397daeSMichal Hocko return page; 17620c397daeSMichal Hocko } 17630c397daeSMichal Hocko 17640c397daeSMichal Hocko /* 1765af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 1766af0fb9dfSMichal Hocko * manner. 1767af0fb9dfSMichal Hocko */ 1768f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 1769f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 1770b2261026SJoonsoo Kim { 1771b2261026SJoonsoo Kim struct page *page; 1772b2261026SJoonsoo Kim int nr_nodes, node; 1773af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 1774b2261026SJoonsoo Kim 1775b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 1776f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 1777f60858f9SMike Kravetz node_alloc_noretry); 1778af0fb9dfSMichal Hocko if (page) 1779b2261026SJoonsoo Kim break; 1780b2261026SJoonsoo Kim } 1781b2261026SJoonsoo Kim 1782af0fb9dfSMichal Hocko if (!page) 1783af0fb9dfSMichal Hocko return 0; 1784b2261026SJoonsoo Kim 1785af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 1786af0fb9dfSMichal Hocko 1787af0fb9dfSMichal Hocko return 1; 1788b2261026SJoonsoo Kim } 1789b2261026SJoonsoo Kim 1790e8c5c824SLee Schermerhorn /* 1791e8c5c824SLee Schermerhorn * Free huge page from pool from next node to free. 1792e8c5c824SLee Schermerhorn * Attempt to keep persistent huge pages more or less 1793e8c5c824SLee Schermerhorn * balanced over allowed nodes. 1794e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 1795e8c5c824SLee Schermerhorn */ 17966ae11b27SLee Schermerhorn static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 17976ae11b27SLee Schermerhorn bool acct_surplus) 1798e8c5c824SLee Schermerhorn { 1799b2261026SJoonsoo Kim int nr_nodes, node; 1800e8c5c824SLee Schermerhorn int ret = 0; 1801e8c5c824SLee Schermerhorn 1802b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 1803685f3457SLee Schermerhorn /* 1804685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 1805685f3457SLee Schermerhorn * nodes with surplus pages. 1806685f3457SLee Schermerhorn */ 1807b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 1808b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 1809e8c5c824SLee Schermerhorn struct page *page = 1810b2261026SJoonsoo Kim list_entry(h->hugepage_freelists[node].next, 1811e8c5c824SLee Schermerhorn struct page, lru); 1812e8c5c824SLee Schermerhorn list_del(&page->lru); 1813e8c5c824SLee Schermerhorn h->free_huge_pages--; 1814b2261026SJoonsoo Kim h->free_huge_pages_node[node]--; 1815685f3457SLee Schermerhorn if (acct_surplus) { 1816685f3457SLee Schermerhorn h->surplus_huge_pages--; 1817b2261026SJoonsoo Kim h->surplus_huge_pages_node[node]--; 1818685f3457SLee Schermerhorn } 1819e8c5c824SLee Schermerhorn update_and_free_page(h, page); 1820e8c5c824SLee Schermerhorn ret = 1; 18219a76db09SLee Schermerhorn break; 1822e8c5c824SLee Schermerhorn } 1823b2261026SJoonsoo Kim } 1824e8c5c824SLee Schermerhorn 1825e8c5c824SLee Schermerhorn return ret; 1826e8c5c824SLee Schermerhorn } 1827e8c5c824SLee Schermerhorn 1828c8721bbbSNaoya Horiguchi /* 1829c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 1830faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 1831faf53defSNaoya Horiguchi * This function returns values like below: 1832faf53defSNaoya Horiguchi * 1833faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 1834faf53defSNaoya Horiguchi * (allocated or reserved.) 1835faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 1836faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 1837c8721bbbSNaoya Horiguchi */ 1838c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 1839c8721bbbSNaoya Horiguchi { 18406bc9b564SNaoya Horiguchi int rc = -EBUSY; 1841082d5b6bSGerald Schaefer 1842faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 1843faf53defSNaoya Horiguchi if (!PageHuge(page)) 1844faf53defSNaoya Horiguchi return 0; 1845faf53defSNaoya Horiguchi 1846c8721bbbSNaoya Horiguchi spin_lock(&hugetlb_lock); 1847faf53defSNaoya Horiguchi if (!PageHuge(page)) { 1848faf53defSNaoya Horiguchi rc = 0; 1849faf53defSNaoya Horiguchi goto out; 1850faf53defSNaoya Horiguchi } 1851faf53defSNaoya Horiguchi 1852faf53defSNaoya Horiguchi if (!page_count(page)) { 18532247bb33SGerald Schaefer struct page *head = compound_head(page); 18542247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 18552247bb33SGerald Schaefer int nid = page_to_nid(head); 18566bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 1857082d5b6bSGerald Schaefer goto out; 1858c3114a84SAnshuman Khandual /* 1859c3114a84SAnshuman Khandual * Move PageHWPoison flag from head page to the raw error page, 1860c3114a84SAnshuman Khandual * which makes any subpages rather than the error page reusable. 1861c3114a84SAnshuman Khandual */ 1862c3114a84SAnshuman Khandual if (PageHWPoison(head) && page != head) { 1863c3114a84SAnshuman Khandual SetPageHWPoison(page); 1864c3114a84SAnshuman Khandual ClearPageHWPoison(head); 1865c3114a84SAnshuman Khandual } 18662247bb33SGerald Schaefer list_del(&head->lru); 1867c8721bbbSNaoya Horiguchi h->free_huge_pages--; 1868c8721bbbSNaoya Horiguchi h->free_huge_pages_node[nid]--; 1869c1470b33Szhong jiang h->max_huge_pages--; 18702247bb33SGerald Schaefer update_and_free_page(h, head); 18716bc9b564SNaoya Horiguchi rc = 0; 1872c8721bbbSNaoya Horiguchi } 1873082d5b6bSGerald Schaefer out: 1874c8721bbbSNaoya Horiguchi spin_unlock(&hugetlb_lock); 1875082d5b6bSGerald Schaefer return rc; 1876c8721bbbSNaoya Horiguchi } 1877c8721bbbSNaoya Horiguchi 1878c8721bbbSNaoya Horiguchi /* 1879c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 1880c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 18812247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 18822247bb33SGerald Schaefer * part of it lies within the given range. 1883082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 1884082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 1885c8721bbbSNaoya Horiguchi */ 1886082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 1887c8721bbbSNaoya Horiguchi { 1888c8721bbbSNaoya Horiguchi unsigned long pfn; 1889eb03aa00SGerald Schaefer struct page *page; 1890082d5b6bSGerald Schaefer int rc = 0; 1891c8721bbbSNaoya Horiguchi 1892d0177639SLi Zhong if (!hugepages_supported()) 1893082d5b6bSGerald Schaefer return rc; 1894d0177639SLi Zhong 1895eb03aa00SGerald Schaefer for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) { 1896eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 1897eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 1898eb03aa00SGerald Schaefer if (rc) 1899082d5b6bSGerald Schaefer break; 1900eb03aa00SGerald Schaefer } 1901082d5b6bSGerald Schaefer 1902082d5b6bSGerald Schaefer return rc; 1903c8721bbbSNaoya Horiguchi } 1904c8721bbbSNaoya Horiguchi 1905ab5ac90aSMichal Hocko /* 1906ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 1907ab5ac90aSMichal Hocko */ 19080c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 1909aaf14e40SMichal Hocko int nid, nodemask_t *nmask) 19107893d1d5SAdam Litke { 19119980d744SMichal Hocko struct page *page = NULL; 19127893d1d5SAdam Litke 1913bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 1914aa888a74SAndi Kleen return NULL; 1915aa888a74SAndi Kleen 1916d1c3fb1fSNishanth Aravamudan spin_lock(&hugetlb_lock); 19179980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 19189980d744SMichal Hocko goto out_unlock; 1919d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 1920d1c3fb1fSNishanth Aravamudan 1921f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 19229980d744SMichal Hocko if (!page) 19230c397daeSMichal Hocko return NULL; 1924d1c3fb1fSNishanth Aravamudan 19257893d1d5SAdam Litke spin_lock(&hugetlb_lock); 19269980d744SMichal Hocko /* 19279980d744SMichal Hocko * We could have raced with the pool size change. 19289980d744SMichal Hocko * Double check that and simply deallocate the new page 19299980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 19309980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 19319980d744SMichal Hocko * codeflow 19329980d744SMichal Hocko */ 19339980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 19349980d744SMichal Hocko SetPageHugeTemporary(page); 19352bf753e6SKai Shen spin_unlock(&hugetlb_lock); 19369980d744SMichal Hocko put_page(page); 19372bf753e6SKai Shen return NULL; 19389980d744SMichal Hocko } else { 19399980d744SMichal Hocko h->surplus_huge_pages++; 19404704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 19417893d1d5SAdam Litke } 19429980d744SMichal Hocko 19439980d744SMichal Hocko out_unlock: 1944d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 19457893d1d5SAdam Litke 19467893d1d5SAdam Litke return page; 19477893d1d5SAdam Litke } 19487893d1d5SAdam Litke 1949bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 1950ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 1951ab5ac90aSMichal Hocko { 1952ab5ac90aSMichal Hocko struct page *page; 1953ab5ac90aSMichal Hocko 1954ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 1955ab5ac90aSMichal Hocko return NULL; 1956ab5ac90aSMichal Hocko 1957f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 1958ab5ac90aSMichal Hocko if (!page) 1959ab5ac90aSMichal Hocko return NULL; 1960ab5ac90aSMichal Hocko 1961ab5ac90aSMichal Hocko /* 1962ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 1963ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 1964ab5ac90aSMichal Hocko */ 1965ab5ac90aSMichal Hocko SetPageHugeTemporary(page); 1966ab5ac90aSMichal Hocko 1967ab5ac90aSMichal Hocko return page; 1968ab5ac90aSMichal Hocko } 1969ab5ac90aSMichal Hocko 1970e4e574b7SAdam Litke /* 1971099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 1972099730d6SDave Hansen */ 1973e0ec90eeSDave Hansen static 19740c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 1975099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 1976099730d6SDave Hansen { 1977aaf14e40SMichal Hocko struct page *page; 1978aaf14e40SMichal Hocko struct mempolicy *mpol; 1979aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 1980aaf14e40SMichal Hocko int nid; 1981aaf14e40SMichal Hocko nodemask_t *nodemask; 1982aaf14e40SMichal Hocko 1983aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 19840c397daeSMichal Hocko page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask); 1985aaf14e40SMichal Hocko mpol_cond_put(mpol); 1986aaf14e40SMichal Hocko 1987aaf14e40SMichal Hocko return page; 1988099730d6SDave Hansen } 1989099730d6SDave Hansen 1990ab5ac90aSMichal Hocko /* page migration callback function */ 19913e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 1992d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 19934db9b2efSMichal Hocko { 19944db9b2efSMichal Hocko spin_lock(&hugetlb_lock); 19954db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 19963e59fcb0SMichal Hocko struct page *page; 19973e59fcb0SMichal Hocko 19983e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 19993e59fcb0SMichal Hocko if (page) { 20003e59fcb0SMichal Hocko spin_unlock(&hugetlb_lock); 20013e59fcb0SMichal Hocko return page; 20024db9b2efSMichal Hocko } 20034db9b2efSMichal Hocko } 20044db9b2efSMichal Hocko spin_unlock(&hugetlb_lock); 20054db9b2efSMichal Hocko 20060c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 20074db9b2efSMichal Hocko } 20084db9b2efSMichal Hocko 2009ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2010389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2011389c8178SMichal Hocko unsigned long address) 2012ebd63723SMichal Hocko { 2013ebd63723SMichal Hocko struct mempolicy *mpol; 2014ebd63723SMichal Hocko nodemask_t *nodemask; 2015ebd63723SMichal Hocko struct page *page; 2016ebd63723SMichal Hocko gfp_t gfp_mask; 2017ebd63723SMichal Hocko int node; 2018ebd63723SMichal Hocko 2019ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2020ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2021d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2022ebd63723SMichal Hocko mpol_cond_put(mpol); 2023ebd63723SMichal Hocko 2024ebd63723SMichal Hocko return page; 2025ebd63723SMichal Hocko } 2026ebd63723SMichal Hocko 2027bf50bab2SNaoya Horiguchi /* 202825985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2029e4e574b7SAdam Litke * of size 'delta'. 2030e4e574b7SAdam Litke */ 2031a5516438SAndi Kleen static int gather_surplus_pages(struct hstate *h, int delta) 20321b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2033e4e574b7SAdam Litke { 2034e4e574b7SAdam Litke struct list_head surplus_list; 2035e4e574b7SAdam Litke struct page *page, *tmp; 2036e4e574b7SAdam Litke int ret, i; 2037e4e574b7SAdam Litke int needed, allocated; 203828073b02SHillf Danton bool alloc_ok = true; 2039e4e574b7SAdam Litke 2040a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2041ac09b3a1SAdam Litke if (needed <= 0) { 2042a5516438SAndi Kleen h->resv_huge_pages += delta; 2043e4e574b7SAdam Litke return 0; 2044ac09b3a1SAdam Litke } 2045e4e574b7SAdam Litke 2046e4e574b7SAdam Litke allocated = 0; 2047e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 2048e4e574b7SAdam Litke 2049e4e574b7SAdam Litke ret = -ENOMEM; 2050e4e574b7SAdam Litke retry: 2051e4e574b7SAdam Litke spin_unlock(&hugetlb_lock); 2052e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 20530c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 2054aaf14e40SMichal Hocko NUMA_NO_NODE, NULL); 205528073b02SHillf Danton if (!page) { 205628073b02SHillf Danton alloc_ok = false; 205728073b02SHillf Danton break; 205828073b02SHillf Danton } 2059e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 206069ed779aSDavid Rientjes cond_resched(); 2061e4e574b7SAdam Litke } 206228073b02SHillf Danton allocated += i; 2063e4e574b7SAdam Litke 2064e4e574b7SAdam Litke /* 2065e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2066e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2067e4e574b7SAdam Litke */ 2068e4e574b7SAdam Litke spin_lock(&hugetlb_lock); 2069a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2070a5516438SAndi Kleen (h->free_huge_pages + allocated); 207128073b02SHillf Danton if (needed > 0) { 207228073b02SHillf Danton if (alloc_ok) 2073e4e574b7SAdam Litke goto retry; 207428073b02SHillf Danton /* 207528073b02SHillf Danton * We were not able to allocate enough pages to 207628073b02SHillf Danton * satisfy the entire reservation so we free what 207728073b02SHillf Danton * we've allocated so far. 207828073b02SHillf Danton */ 207928073b02SHillf Danton goto free; 208028073b02SHillf Danton } 2081e4e574b7SAdam Litke /* 2082e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 208325985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2084e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2085ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2086ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2087ac09b3a1SAdam Litke * before they are reserved. 2088e4e574b7SAdam Litke */ 2089e4e574b7SAdam Litke needed += allocated; 2090a5516438SAndi Kleen h->resv_huge_pages += delta; 2091e4e574b7SAdam Litke ret = 0; 2092a9869b83SNaoya Horiguchi 209319fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 209419fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 209519fc3f0aSAdam Litke if ((--needed) < 0) 209619fc3f0aSAdam Litke break; 2097a9869b83SNaoya Horiguchi /* 2098a9869b83SNaoya Horiguchi * This page is now managed by the hugetlb allocator and has 2099a9869b83SNaoya Horiguchi * no users -- drop the buddy allocator's reference. 2100a9869b83SNaoya Horiguchi */ 2101a9869b83SNaoya Horiguchi put_page_testzero(page); 2102309381feSSasha Levin VM_BUG_ON_PAGE(page_count(page), page); 2103a5516438SAndi Kleen enqueue_huge_page(h, page); 210419fc3f0aSAdam Litke } 210528073b02SHillf Danton free: 2106b0365c8dSHillf Danton spin_unlock(&hugetlb_lock); 210719fc3f0aSAdam Litke 210819fc3f0aSAdam Litke /* Free unnecessary surplus pages to the buddy allocator */ 2109c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2110a9869b83SNaoya Horiguchi put_page(page); 211119fc3f0aSAdam Litke spin_lock(&hugetlb_lock); 2112e4e574b7SAdam Litke 2113e4e574b7SAdam Litke return ret; 2114e4e574b7SAdam Litke } 2115e4e574b7SAdam Litke 2116e4e574b7SAdam Litke /* 2117e5bbc8a6SMike Kravetz * This routine has two main purposes: 2118e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2119e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2120e5bbc8a6SMike Kravetz * to the associated reservation map. 2121e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2122e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2123e5bbc8a6SMike Kravetz * 2124e5bbc8a6SMike Kravetz * Called with hugetlb_lock held. However, the lock could be dropped (and 2125e5bbc8a6SMike Kravetz * reacquired) during calls to cond_resched_lock. Whenever dropping the lock, 2126e5bbc8a6SMike Kravetz * we must make sure nobody else can claim pages we are in the process of 2127e5bbc8a6SMike Kravetz * freeing. Do this by ensuring resv_huge_page always is greater than the 2128e5bbc8a6SMike Kravetz * number of huge pages we plan to free when dropping the lock. 2129e4e574b7SAdam Litke */ 2130a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2131a5516438SAndi Kleen unsigned long unused_resv_pages) 2132e4e574b7SAdam Litke { 2133e4e574b7SAdam Litke unsigned long nr_pages; 2134e4e574b7SAdam Litke 2135aa888a74SAndi Kleen /* Cannot return gigantic pages currently */ 2136bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2137e5bbc8a6SMike Kravetz goto out; 2138aa888a74SAndi Kleen 2139e5bbc8a6SMike Kravetz /* 2140e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2141e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2142e5bbc8a6SMike Kravetz */ 2143a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2144e4e574b7SAdam Litke 2145685f3457SLee Schermerhorn /* 2146685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 21479b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 21489b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 21499b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 21509e7ee400SRandy Dunlap * free_pool_huge_page() will balance the freed pages across the 21519b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2152e5bbc8a6SMike Kravetz * 2153e5bbc8a6SMike Kravetz * Note that we decrement resv_huge_pages as we free the pages. If 2154e5bbc8a6SMike Kravetz * we drop the lock, resv_huge_pages will still be sufficiently large 2155e5bbc8a6SMike Kravetz * to cover subsequent pages we may free. 2156685f3457SLee Schermerhorn */ 2157685f3457SLee Schermerhorn while (nr_pages--) { 2158e5bbc8a6SMike Kravetz h->resv_huge_pages--; 2159e5bbc8a6SMike Kravetz unused_resv_pages--; 21608cebfcd0SLai Jiangshan if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1)) 2161e5bbc8a6SMike Kravetz goto out; 21627848a4bfSMizuma, Masayoshi cond_resched_lock(&hugetlb_lock); 2163e4e574b7SAdam Litke } 2164e5bbc8a6SMike Kravetz 2165e5bbc8a6SMike Kravetz out: 2166e5bbc8a6SMike Kravetz /* Fully uncommit the reservation */ 2167e5bbc8a6SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2168e4e574b7SAdam Litke } 2169e4e574b7SAdam Litke 21705e911373SMike Kravetz 2171c37f9fb1SAndy Whitcroft /* 2172feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 21735e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2174cf3ad20bSMike Kravetz * 2175cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2176cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2177cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2178cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2179cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2180feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2181feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2182feba16e2SMike Kravetz * is called in such cases. 2183cf3ad20bSMike Kravetz * 2184cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2185cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2186cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2187cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2188cf3ad20bSMike Kravetz * take appropriate action. 218996b96a96SMike Kravetz * 219096b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 219196b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 219296b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 219396b96a96SMike Kravetz * reservation exists. 2194c37f9fb1SAndy Whitcroft */ 21955e911373SMike Kravetz enum vma_resv_mode { 21965e911373SMike Kravetz VMA_NEEDS_RESV, 21975e911373SMike Kravetz VMA_COMMIT_RESV, 2198feba16e2SMike Kravetz VMA_END_RESV, 219996b96a96SMike Kravetz VMA_ADD_RESV, 22005e911373SMike Kravetz }; 2201cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2202cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 22035e911373SMike Kravetz enum vma_resv_mode mode) 2204c37f9fb1SAndy Whitcroft { 22054e35f483SJoonsoo Kim struct resv_map *resv; 22064e35f483SJoonsoo Kim pgoff_t idx; 2207cf3ad20bSMike Kravetz long ret; 22080db9d74eSMina Almasry long dummy_out_regions_needed; 2209c37f9fb1SAndy Whitcroft 22104e35f483SJoonsoo Kim resv = vma_resv_map(vma); 22114e35f483SJoonsoo Kim if (!resv) 2212c37f9fb1SAndy Whitcroft return 1; 2213c37f9fb1SAndy Whitcroft 22144e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 22155e911373SMike Kravetz switch (mode) { 22165e911373SMike Kravetz case VMA_NEEDS_RESV: 22170db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 22180db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 22190db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 22200db9d74eSMina Almasry * ever require 1 region. 22210db9d74eSMina Almasry */ 22220db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 22235e911373SMike Kravetz break; 22245e911373SMike Kravetz case VMA_COMMIT_RESV: 2225075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 22260db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 22270db9d74eSMina Almasry VM_BUG_ON(ret < 0); 22285e911373SMike Kravetz break; 2229feba16e2SMike Kravetz case VMA_END_RESV: 22300db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 22315e911373SMike Kravetz ret = 0; 22325e911373SMike Kravetz break; 223396b96a96SMike Kravetz case VMA_ADD_RESV: 22340db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2235075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 22360db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 22370db9d74eSMina Almasry VM_BUG_ON(ret < 0); 22380db9d74eSMina Almasry } else { 22390db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 224096b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 224196b96a96SMike Kravetz } 224296b96a96SMike Kravetz break; 22435e911373SMike Kravetz default: 22445e911373SMike Kravetz BUG(); 22455e911373SMike Kravetz } 224684afd99bSAndy Whitcroft 22474e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) 2248cf3ad20bSMike Kravetz return ret; 224967961f9dSMike Kravetz else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && ret >= 0) { 225067961f9dSMike Kravetz /* 225167961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 225267961f9dSMike Kravetz * However, a file associated with mapping could have been 225367961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 225467961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 225567961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 225667961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 225767961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 225867961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 225967961f9dSMike Kravetz * reservation has already been consumed. As a result, the 226067961f9dSMike Kravetz * return value of this routine is the opposite of the 226167961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 226267961f9dSMike Kravetz */ 226367961f9dSMike Kravetz if (ret) 226467961f9dSMike Kravetz return 0; 226567961f9dSMike Kravetz else 226667961f9dSMike Kravetz return 1; 226767961f9dSMike Kravetz } 22684e35f483SJoonsoo Kim else 2269cf3ad20bSMike Kravetz return ret < 0 ? ret : 0; 227084afd99bSAndy Whitcroft } 2271cf3ad20bSMike Kravetz 2272cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2273a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2274c37f9fb1SAndy Whitcroft { 22755e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2276cf3ad20bSMike Kravetz } 2277c37f9fb1SAndy Whitcroft 2278cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2279cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2280cf3ad20bSMike Kravetz { 22815e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 22825e911373SMike Kravetz } 22835e911373SMike Kravetz 2284feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 22855e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 22865e911373SMike Kravetz { 2287feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2288c37f9fb1SAndy Whitcroft } 2289c37f9fb1SAndy Whitcroft 229096b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 229196b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 229296b96a96SMike Kravetz { 229396b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 229496b96a96SMike Kravetz } 229596b96a96SMike Kravetz 229696b96a96SMike Kravetz /* 229796b96a96SMike Kravetz * This routine is called to restore a reservation on error paths. In the 229896b96a96SMike Kravetz * specific error paths, a huge page was allocated (via alloc_huge_page) 229996b96a96SMike Kravetz * and is about to be freed. If a reservation for the page existed, 230096b96a96SMike Kravetz * alloc_huge_page would have consumed the reservation and set PagePrivate 230196b96a96SMike Kravetz * in the newly allocated page. When the page is freed via free_huge_page, 230296b96a96SMike Kravetz * the global reservation count will be incremented if PagePrivate is set. 230396b96a96SMike Kravetz * However, free_huge_page can not adjust the reserve map. Adjust the 230496b96a96SMike Kravetz * reserve map here to be consistent with global reserve count adjustments 230596b96a96SMike Kravetz * to be made by free_huge_page. 230696b96a96SMike Kravetz */ 230796b96a96SMike Kravetz static void restore_reserve_on_error(struct hstate *h, 230896b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long address, 230996b96a96SMike Kravetz struct page *page) 231096b96a96SMike Kravetz { 231196b96a96SMike Kravetz if (unlikely(PagePrivate(page))) { 231296b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 231396b96a96SMike Kravetz 231496b96a96SMike Kravetz if (unlikely(rc < 0)) { 231596b96a96SMike Kravetz /* 231696b96a96SMike Kravetz * Rare out of memory condition in reserve map 231796b96a96SMike Kravetz * manipulation. Clear PagePrivate so that 231896b96a96SMike Kravetz * global reserve count will not be incremented 231996b96a96SMike Kravetz * by free_huge_page. This will make it appear 232096b96a96SMike Kravetz * as though the reservation for this page was 232196b96a96SMike Kravetz * consumed. This may prevent the task from 232296b96a96SMike Kravetz * faulting in the page at a later time. This 232396b96a96SMike Kravetz * is better than inconsistent global huge page 232496b96a96SMike Kravetz * accounting of reserve counts. 232596b96a96SMike Kravetz */ 232696b96a96SMike Kravetz ClearPagePrivate(page); 232796b96a96SMike Kravetz } else if (rc) { 232896b96a96SMike Kravetz rc = vma_add_reservation(h, vma, address); 232996b96a96SMike Kravetz if (unlikely(rc < 0)) 233096b96a96SMike Kravetz /* 233196b96a96SMike Kravetz * See above comment about rare out of 233296b96a96SMike Kravetz * memory condition. 233396b96a96SMike Kravetz */ 233496b96a96SMike Kravetz ClearPagePrivate(page); 233596b96a96SMike Kravetz } else 233696b96a96SMike Kravetz vma_end_reservation(h, vma, address); 233796b96a96SMike Kravetz } 233896b96a96SMike Kravetz } 233996b96a96SMike Kravetz 234070c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 234104f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2342348ea204SAdam Litke { 234390481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2344a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2345348ea204SAdam Litke struct page *page; 2346d85f69b0SMike Kravetz long map_chg, map_commit; 2347d85f69b0SMike Kravetz long gbl_chg; 23486d76dcf4SAneesh Kumar K.V int ret, idx; 23496d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 235008cf9fafSMina Almasry bool deferred_reserve; 23512fc39cecSAdam Litke 23526d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2353a1e78772SMel Gorman /* 2354d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2355d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2356d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2357a1e78772SMel Gorman */ 2358d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2359d85f69b0SMike Kravetz if (map_chg < 0) 236076dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2361d85f69b0SMike Kravetz 2362d85f69b0SMike Kravetz /* 2363d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2364d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2365d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2366d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2367d85f69b0SMike Kravetz * checked against any subpool limit. 2368d85f69b0SMike Kravetz */ 2369d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2370d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2371d85f69b0SMike Kravetz if (gbl_chg < 0) { 2372feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 237376dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 23745e911373SMike Kravetz } 237590d8b7e6SAdam Litke 2376d85f69b0SMike Kravetz /* 2377d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2378d85f69b0SMike Kravetz * map, there could be reservations associated with the 2379d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2380d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2381d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2382d85f69b0SMike Kravetz * the subpool reservations. 2383d85f69b0SMike Kravetz */ 2384d85f69b0SMike Kravetz if (avoid_reserve) 2385d85f69b0SMike Kravetz gbl_chg = 1; 2386d85f69b0SMike Kravetz } 2387d85f69b0SMike Kravetz 238808cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 238908cf9fafSMina Almasry */ 239008cf9fafSMina Almasry deferred_reserve = map_chg || avoid_reserve || !vma_resv_map(vma); 239108cf9fafSMina Almasry if (deferred_reserve) { 239208cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 239308cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 23948f34af6fSJianyu Zhan if (ret) 23958f34af6fSJianyu Zhan goto out_subpool_put; 239608cf9fafSMina Almasry } 239708cf9fafSMina Almasry 239808cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 239908cf9fafSMina Almasry if (ret) 240008cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 24018f34af6fSJianyu Zhan 2402a1e78772SMel Gorman spin_lock(&hugetlb_lock); 2403d85f69b0SMike Kravetz /* 2404d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2405d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2406d85f69b0SMike Kravetz * a reservation exists for the allocation. 2407d85f69b0SMike Kravetz */ 2408d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 240981a6fcaeSJoonsoo Kim if (!page) { 241094ae8ba7SAneesh Kumar K.V spin_unlock(&hugetlb_lock); 24110c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 24128f34af6fSJianyu Zhan if (!page) 24138f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2414a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2415a88c7695SNaoya Horiguchi SetPagePrivate(page); 2416a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2417a88c7695SNaoya Horiguchi } 241879dbb236SAneesh Kumar K.V spin_lock(&hugetlb_lock); 241979dbb236SAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 242081a6fcaeSJoonsoo Kim /* Fall through */ 2421a1e78772SMel Gorman } 242281a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 242308cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 242408cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 242508cf9fafSMina Almasry */ 242608cf9fafSMina Almasry if (deferred_reserve) { 242708cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 242808cf9fafSMina Almasry h_cg, page); 242908cf9fafSMina Almasry } 243008cf9fafSMina Almasry 243181a6fcaeSJoonsoo Kim spin_unlock(&hugetlb_lock); 2432a1e78772SMel Gorman 243390481622SDavid Gibson set_page_private(page, (unsigned long)spool); 2434a1e78772SMel Gorman 2435d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2436d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 243733039678SMike Kravetz /* 243833039678SMike Kravetz * The page was added to the reservation map between 243933039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 244033039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 244133039678SMike Kravetz * Adjust for the subpool count incremented above AND 244233039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 244333039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 244433039678SMike Kravetz * no longer applies. 244533039678SMike Kravetz */ 244633039678SMike Kravetz long rsv_adjust; 244733039678SMike Kravetz 244833039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 244933039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 245033039678SMike Kravetz } 24517893d1d5SAdam Litke return page; 24528f34af6fSJianyu Zhan 24538f34af6fSJianyu Zhan out_uncharge_cgroup: 24548f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 245508cf9fafSMina Almasry out_uncharge_cgroup_reservation: 245608cf9fafSMina Almasry if (deferred_reserve) 245708cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 245808cf9fafSMina Almasry h_cg); 24598f34af6fSJianyu Zhan out_subpool_put: 2460d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 24618f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2462feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 24638f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2464b45b5bd6SDavid Gibson } 2465b45b5bd6SDavid Gibson 2466e24a1307SAneesh Kumar K.V int alloc_bootmem_huge_page(struct hstate *h) 2467e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2468e24a1307SAneesh Kumar K.V int __alloc_bootmem_huge_page(struct hstate *h) 2469aa888a74SAndi Kleen { 2470aa888a74SAndi Kleen struct huge_bootmem_page *m; 2471b2261026SJoonsoo Kim int nr_nodes, node; 2472aa888a74SAndi Kleen 2473b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 2474aa888a74SAndi Kleen void *addr; 2475aa888a74SAndi Kleen 2476eb31d559SMike Rapoport addr = memblock_alloc_try_nid_raw( 24778b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 247897ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 2479aa888a74SAndi Kleen if (addr) { 2480aa888a74SAndi Kleen /* 2481aa888a74SAndi Kleen * Use the beginning of the huge page to store the 2482aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 2483aa888a74SAndi Kleen * puts them into the mem_map). 2484aa888a74SAndi Kleen */ 2485aa888a74SAndi Kleen m = addr; 2486aa888a74SAndi Kleen goto found; 2487aa888a74SAndi Kleen } 2488aa888a74SAndi Kleen } 2489aa888a74SAndi Kleen return 0; 2490aa888a74SAndi Kleen 2491aa888a74SAndi Kleen found: 2492df994eadSLuiz Capitulino BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h))); 2493aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 2494330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 2495aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 2496aa888a74SAndi Kleen m->hstate = h; 2497aa888a74SAndi Kleen return 1; 2498aa888a74SAndi Kleen } 2499aa888a74SAndi Kleen 2500d00181b9SKirill A. Shutemov static void __init prep_compound_huge_page(struct page *page, 2501d00181b9SKirill A. Shutemov unsigned int order) 250218229df5SAndy Whitcroft { 250318229df5SAndy Whitcroft if (unlikely(order > (MAX_ORDER - 1))) 250418229df5SAndy Whitcroft prep_compound_gigantic_page(page, order); 250518229df5SAndy Whitcroft else 250618229df5SAndy Whitcroft prep_compound_page(page, order); 250718229df5SAndy Whitcroft } 250818229df5SAndy Whitcroft 2509aa888a74SAndi Kleen /* Put bootmem huge pages into the standard lists after mem_map is up */ 2510aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 2511aa888a74SAndi Kleen { 2512aa888a74SAndi Kleen struct huge_bootmem_page *m; 2513aa888a74SAndi Kleen 2514aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 251540d18ebfSMike Kravetz struct page *page = virt_to_page(m); 2516aa888a74SAndi Kleen struct hstate *h = m->hstate; 2517ee8f248dSBecky Bruce 2518aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 251918229df5SAndy Whitcroft prep_compound_huge_page(page, h->order); 2520ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 2521aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 2522af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 2523af0fb9dfSMichal Hocko 2524b0320c7bSRafael Aquini /* 2525b0320c7bSRafael Aquini * If we had gigantic hugepages allocated at boot time, we need 2526b0320c7bSRafael Aquini * to restore the 'stolen' pages to totalram_pages in order to 2527b0320c7bSRafael Aquini * fix confusing memory reports from free(1) and another 2528b0320c7bSRafael Aquini * side-effects, like CommitLimit going negative. 2529b0320c7bSRafael Aquini */ 2530bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 25313dcc0571SJiang Liu adjust_managed_page_count(page, 1 << h->order); 2532520495feSCannon Matthews cond_resched(); 2533aa888a74SAndi Kleen } 2534aa888a74SAndi Kleen } 2535aa888a74SAndi Kleen 25368faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 25371da177e4SLinus Torvalds { 25381da177e4SLinus Torvalds unsigned long i; 2539f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 2540f60858f9SMike Kravetz 2541f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 2542f60858f9SMike Kravetz /* 2543f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 2544f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 2545f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 2546f60858f9SMike Kravetz * time, we are likely in bigger trouble. 2547f60858f9SMike Kravetz */ 2548f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 2549f60858f9SMike Kravetz GFP_KERNEL); 2550f60858f9SMike Kravetz } else { 2551f60858f9SMike Kravetz /* allocations done at boot time */ 2552f60858f9SMike Kravetz node_alloc_noretry = NULL; 2553f60858f9SMike Kravetz } 2554f60858f9SMike Kravetz 2555f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 2556f60858f9SMike Kravetz if (node_alloc_noretry) 2557f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 25581da177e4SLinus Torvalds 2559e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 2560bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 2561dbda8feaSBarry Song if (hugetlb_cma_size) { 2562cf11e85fSRoman Gushchin pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 2563cf11e85fSRoman Gushchin break; 2564cf11e85fSRoman Gushchin } 2565aa888a74SAndi Kleen if (!alloc_bootmem_huge_page(h)) 2566aa888a74SAndi Kleen break; 25670c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 2568f60858f9SMike Kravetz &node_states[N_MEMORY], 2569f60858f9SMike Kravetz node_alloc_noretry)) 25701da177e4SLinus Torvalds break; 257169ed779aSDavid Rientjes cond_resched(); 25721da177e4SLinus Torvalds } 2573d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 2574d715cf80SLiam R. Howlett char buf[32]; 2575d715cf80SLiam R. Howlett 2576c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 2577d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 2578d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 25798faa8b07SAndi Kleen h->max_huge_pages = i; 2580e5ff2159SAndi Kleen } 2581f60858f9SMike Kravetz 2582f60858f9SMike Kravetz kfree(node_alloc_noretry); 2583d715cf80SLiam R. Howlett } 2584e5ff2159SAndi Kleen 2585e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 2586e5ff2159SAndi Kleen { 2587e5ff2159SAndi Kleen struct hstate *h; 2588e5ff2159SAndi Kleen 2589e5ff2159SAndi Kleen for_each_hstate(h) { 2590641844f5SNaoya Horiguchi if (minimum_order > huge_page_order(h)) 2591641844f5SNaoya Horiguchi minimum_order = huge_page_order(h); 2592641844f5SNaoya Horiguchi 25938faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 2594bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 25958faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 2596e5ff2159SAndi Kleen } 2597641844f5SNaoya Horiguchi VM_BUG_ON(minimum_order == UINT_MAX); 2598e5ff2159SAndi Kleen } 2599e5ff2159SAndi Kleen 2600e5ff2159SAndi Kleen static void __init report_hugepages(void) 2601e5ff2159SAndi Kleen { 2602e5ff2159SAndi Kleen struct hstate *h; 2603e5ff2159SAndi Kleen 2604e5ff2159SAndi Kleen for_each_hstate(h) { 26054abd32dbSAndi Kleen char buf[32]; 2606c6247f72SMatthew Wilcox 2607c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 2608ffb22af5SAndrew Morton pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", 2609c6247f72SMatthew Wilcox buf, h->free_huge_pages); 2610e5ff2159SAndi Kleen } 2611e5ff2159SAndi Kleen } 2612e5ff2159SAndi Kleen 26131da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 26146ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 26156ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 26161da177e4SLinus Torvalds { 26174415cc8dSChristoph Lameter int i; 26184415cc8dSChristoph Lameter 2619bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2620aa888a74SAndi Kleen return; 2621aa888a74SAndi Kleen 26226ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 26231da177e4SLinus Torvalds struct page *page, *next; 2624a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 2625a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 2626a5516438SAndi Kleen if (count >= h->nr_huge_pages) 26276b0c880dSAdam Litke return; 26281da177e4SLinus Torvalds if (PageHighMem(page)) 26291da177e4SLinus Torvalds continue; 26301da177e4SLinus Torvalds list_del(&page->lru); 2631e5ff2159SAndi Kleen update_and_free_page(h, page); 2632a5516438SAndi Kleen h->free_huge_pages--; 2633a5516438SAndi Kleen h->free_huge_pages_node[page_to_nid(page)]--; 26341da177e4SLinus Torvalds } 26351da177e4SLinus Torvalds } 26361da177e4SLinus Torvalds } 26371da177e4SLinus Torvalds #else 26386ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 26396ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 26401da177e4SLinus Torvalds { 26411da177e4SLinus Torvalds } 26421da177e4SLinus Torvalds #endif 26431da177e4SLinus Torvalds 264420a0307cSWu Fengguang /* 264520a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 264620a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 264720a0307cSWu Fengguang * Returns 1 if an adjustment was made. 264820a0307cSWu Fengguang */ 26496ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 26506ae11b27SLee Schermerhorn int delta) 265120a0307cSWu Fengguang { 2652b2261026SJoonsoo Kim int nr_nodes, node; 265320a0307cSWu Fengguang 265420a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 265520a0307cSWu Fengguang 2656e8c5c824SLee Schermerhorn if (delta < 0) { 2657b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 2658b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 2659b2261026SJoonsoo Kim goto found; 2660b2261026SJoonsoo Kim } 2661b2261026SJoonsoo Kim } else { 2662b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2663b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 2664b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 2665b2261026SJoonsoo Kim goto found; 2666e8c5c824SLee Schermerhorn } 26679a76db09SLee Schermerhorn } 2668b2261026SJoonsoo Kim return 0; 266920a0307cSWu Fengguang 2670b2261026SJoonsoo Kim found: 267120a0307cSWu Fengguang h->surplus_huge_pages += delta; 2672b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 2673b2261026SJoonsoo Kim return 1; 267420a0307cSWu Fengguang } 267520a0307cSWu Fengguang 2676a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 2677fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 26786ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 26791da177e4SLinus Torvalds { 26807893d1d5SAdam Litke unsigned long min_count, ret; 2681f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 2682f60858f9SMike Kravetz 2683f60858f9SMike Kravetz /* 2684f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 2685f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 2686f60858f9SMike Kravetz * the requested huge pages. 2687f60858f9SMike Kravetz */ 2688f60858f9SMike Kravetz if (node_alloc_noretry) 2689f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 2690f60858f9SMike Kravetz else 2691f60858f9SMike Kravetz return -ENOMEM; 26921da177e4SLinus Torvalds 26934eb0716eSAlexandre Ghiti spin_lock(&hugetlb_lock); 26944eb0716eSAlexandre Ghiti 26954eb0716eSAlexandre Ghiti /* 2696fd875dcaSMike Kravetz * Check for a node specific request. 2697fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 2698fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 2699fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 2700fd875dcaSMike Kravetz */ 2701fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 2702fd875dcaSMike Kravetz unsigned long old_count = count; 2703fd875dcaSMike Kravetz 2704fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 2705fd875dcaSMike Kravetz /* 2706fd875dcaSMike Kravetz * User may have specified a large count value which caused the 2707fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 2708fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 2709fd875dcaSMike Kravetz * largest possible value to align with their intention. 2710fd875dcaSMike Kravetz */ 2711fd875dcaSMike Kravetz if (count < old_count) 2712fd875dcaSMike Kravetz count = ULONG_MAX; 2713fd875dcaSMike Kravetz } 2714fd875dcaSMike Kravetz 2715fd875dcaSMike Kravetz /* 27164eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 27174eb0716eSAlexandre Ghiti * page range allocation. 27184eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 27194eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 27204eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 27214eb0716eSAlexandre Ghiti */ 27224eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 27234eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 27244eb0716eSAlexandre Ghiti spin_unlock(&hugetlb_lock); 2725f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 27264eb0716eSAlexandre Ghiti return -EINVAL; 27274eb0716eSAlexandre Ghiti } 27284eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 27294eb0716eSAlexandre Ghiti } 2730aa888a74SAndi Kleen 27317893d1d5SAdam Litke /* 27327893d1d5SAdam Litke * Increase the pool size 27337893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 27347893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 2735d1c3fb1fSNishanth Aravamudan * 27360c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 2737d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 2738d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 2739d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 2740d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 27417893d1d5SAdam Litke */ 2742a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 27436ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 27447893d1d5SAdam Litke break; 27457893d1d5SAdam Litke } 27467893d1d5SAdam Litke 2747a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 27487893d1d5SAdam Litke /* 27497893d1d5SAdam Litke * If this allocation races such that we no longer need the 27507893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 27517893d1d5SAdam Litke * and reducing the surplus. 27527893d1d5SAdam Litke */ 27537893d1d5SAdam Litke spin_unlock(&hugetlb_lock); 2754649920c6SJia He 2755649920c6SJia He /* yield cpu to avoid soft lockup */ 2756649920c6SJia He cond_resched(); 2757649920c6SJia He 2758f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 2759f60858f9SMike Kravetz node_alloc_noretry); 27607893d1d5SAdam Litke spin_lock(&hugetlb_lock); 27617893d1d5SAdam Litke if (!ret) 27627893d1d5SAdam Litke goto out; 27637893d1d5SAdam Litke 2764536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 2765536240f2SMel Gorman if (signal_pending(current)) 2766536240f2SMel Gorman goto out; 27677893d1d5SAdam Litke } 27687893d1d5SAdam Litke 27697893d1d5SAdam Litke /* 27707893d1d5SAdam Litke * Decrease the pool size 27717893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 27727893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 27737893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 27747893d1d5SAdam Litke * to the desired size as pages become free. 2775d1c3fb1fSNishanth Aravamudan * 2776d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 2777d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 2778d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 27790c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 2780d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 2781d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 2782d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 27837893d1d5SAdam Litke */ 2784a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 27856b0c880dSAdam Litke min_count = max(count, min_count); 27866ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 2787a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 27886ae11b27SLee Schermerhorn if (!free_pool_huge_page(h, nodes_allowed, 0)) 27891da177e4SLinus Torvalds break; 279055f67141SMizuma, Masayoshi cond_resched_lock(&hugetlb_lock); 27911da177e4SLinus Torvalds } 2792a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 27936ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 27947893d1d5SAdam Litke break; 27957893d1d5SAdam Litke } 27967893d1d5SAdam Litke out: 27974eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 27981da177e4SLinus Torvalds spin_unlock(&hugetlb_lock); 27994eb0716eSAlexandre Ghiti 2800f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 2801f60858f9SMike Kravetz 28024eb0716eSAlexandre Ghiti return 0; 28031da177e4SLinus Torvalds } 28041da177e4SLinus Torvalds 2805a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 2806a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 2807a3437870SNishanth Aravamudan 2808a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 2809a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = \ 2810a3437870SNishanth Aravamudan __ATTR(_name, 0644, _name##_show, _name##_store) 2811a3437870SNishanth Aravamudan 2812a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 2813a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 2814a3437870SNishanth Aravamudan 28159a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 28169a305230SLee Schermerhorn 28179a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 2818a3437870SNishanth Aravamudan { 2819a3437870SNishanth Aravamudan int i; 28209a305230SLee Schermerhorn 2821a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 28229a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 28239a305230SLee Schermerhorn if (nidp) 28249a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 2825a3437870SNishanth Aravamudan return &hstates[i]; 28269a305230SLee Schermerhorn } 28279a305230SLee Schermerhorn 28289a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 2829a3437870SNishanth Aravamudan } 2830a3437870SNishanth Aravamudan 283106808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 2832a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2833a3437870SNishanth Aravamudan { 28349a305230SLee Schermerhorn struct hstate *h; 28359a305230SLee Schermerhorn unsigned long nr_huge_pages; 28369a305230SLee Schermerhorn int nid; 28379a305230SLee Schermerhorn 28389a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 28399a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 28409a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 28419a305230SLee Schermerhorn else 28429a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 28439a305230SLee Schermerhorn 28449a305230SLee Schermerhorn return sprintf(buf, "%lu\n", nr_huge_pages); 2845a3437870SNishanth Aravamudan } 2846adbe8726SEric B Munson 2847238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 2848238d3c13SDavid Rientjes struct hstate *h, int nid, 2849238d3c13SDavid Rientjes unsigned long count, size_t len) 2850a3437870SNishanth Aravamudan { 2851a3437870SNishanth Aravamudan int err; 28522d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 2853a3437870SNishanth Aravamudan 28542d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 28552d0adf7eSOscar Salvador return -EINVAL; 2856adbe8726SEric B Munson 28579a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 28589a305230SLee Schermerhorn /* 28599a305230SLee Schermerhorn * global hstate attribute 28609a305230SLee Schermerhorn */ 28619a305230SLee Schermerhorn if (!(obey_mempolicy && 28622d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 28632d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 28642d0adf7eSOscar Salvador else 28652d0adf7eSOscar Salvador n_mask = &nodes_allowed; 28662d0adf7eSOscar Salvador } else { 28679a305230SLee Schermerhorn /* 2868fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 2869fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 28709a305230SLee Schermerhorn */ 28712d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 28722d0adf7eSOscar Salvador n_mask = &nodes_allowed; 2873fd875dcaSMike Kravetz } 28749a305230SLee Schermerhorn 28752d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 287606808b08SLee Schermerhorn 28774eb0716eSAlexandre Ghiti return err ? err : len; 287806808b08SLee Schermerhorn } 287906808b08SLee Schermerhorn 2880238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 2881238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 2882238d3c13SDavid Rientjes size_t len) 2883238d3c13SDavid Rientjes { 2884238d3c13SDavid Rientjes struct hstate *h; 2885238d3c13SDavid Rientjes unsigned long count; 2886238d3c13SDavid Rientjes int nid; 2887238d3c13SDavid Rientjes int err; 2888238d3c13SDavid Rientjes 2889238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 2890238d3c13SDavid Rientjes if (err) 2891238d3c13SDavid Rientjes return err; 2892238d3c13SDavid Rientjes 2893238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 2894238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 2895238d3c13SDavid Rientjes } 2896238d3c13SDavid Rientjes 289706808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 289806808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 289906808b08SLee Schermerhorn { 290006808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 290106808b08SLee Schermerhorn } 290206808b08SLee Schermerhorn 290306808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 290406808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 290506808b08SLee Schermerhorn { 2906238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 2907a3437870SNishanth Aravamudan } 2908a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 2909a3437870SNishanth Aravamudan 291006808b08SLee Schermerhorn #ifdef CONFIG_NUMA 291106808b08SLee Schermerhorn 291206808b08SLee Schermerhorn /* 291306808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 291406808b08SLee Schermerhorn * huge page alloc/free. 291506808b08SLee Schermerhorn */ 291606808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 291706808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 291806808b08SLee Schermerhorn { 291906808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 292006808b08SLee Schermerhorn } 292106808b08SLee Schermerhorn 292206808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 292306808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 292406808b08SLee Schermerhorn { 2925238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 292606808b08SLee Schermerhorn } 292706808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 292806808b08SLee Schermerhorn #endif 292906808b08SLee Schermerhorn 293006808b08SLee Schermerhorn 2931a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 2932a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2933a3437870SNishanth Aravamudan { 29349a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 2935a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); 2936a3437870SNishanth Aravamudan } 2937adbe8726SEric B Munson 2938a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 2939a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 2940a3437870SNishanth Aravamudan { 2941a3437870SNishanth Aravamudan int err; 2942a3437870SNishanth Aravamudan unsigned long input; 29439a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 2944a3437870SNishanth Aravamudan 2945bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2946adbe8726SEric B Munson return -EINVAL; 2947adbe8726SEric B Munson 29483dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 2949a3437870SNishanth Aravamudan if (err) 295073ae31e5SEric B Munson return err; 2951a3437870SNishanth Aravamudan 2952a3437870SNishanth Aravamudan spin_lock(&hugetlb_lock); 2953a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 2954a3437870SNishanth Aravamudan spin_unlock(&hugetlb_lock); 2955a3437870SNishanth Aravamudan 2956a3437870SNishanth Aravamudan return count; 2957a3437870SNishanth Aravamudan } 2958a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 2959a3437870SNishanth Aravamudan 2960a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 2961a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2962a3437870SNishanth Aravamudan { 29639a305230SLee Schermerhorn struct hstate *h; 29649a305230SLee Schermerhorn unsigned long free_huge_pages; 29659a305230SLee Schermerhorn int nid; 29669a305230SLee Schermerhorn 29679a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 29689a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 29699a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 29709a305230SLee Schermerhorn else 29719a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 29729a305230SLee Schermerhorn 29739a305230SLee Schermerhorn return sprintf(buf, "%lu\n", free_huge_pages); 2974a3437870SNishanth Aravamudan } 2975a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 2976a3437870SNishanth Aravamudan 2977a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 2978a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2979a3437870SNishanth Aravamudan { 29809a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 2981a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->resv_huge_pages); 2982a3437870SNishanth Aravamudan } 2983a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 2984a3437870SNishanth Aravamudan 2985a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 2986a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2987a3437870SNishanth Aravamudan { 29889a305230SLee Schermerhorn struct hstate *h; 29899a305230SLee Schermerhorn unsigned long surplus_huge_pages; 29909a305230SLee Schermerhorn int nid; 29919a305230SLee Schermerhorn 29929a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 29939a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 29949a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 29959a305230SLee Schermerhorn else 29969a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 29979a305230SLee Schermerhorn 29989a305230SLee Schermerhorn return sprintf(buf, "%lu\n", surplus_huge_pages); 2999a3437870SNishanth Aravamudan } 3000a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3001a3437870SNishanth Aravamudan 3002a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3003a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3004a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3005a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3006a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3007a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 300806808b08SLee Schermerhorn #ifdef CONFIG_NUMA 300906808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 301006808b08SLee Schermerhorn #endif 3011a3437870SNishanth Aravamudan NULL, 3012a3437870SNishanth Aravamudan }; 3013a3437870SNishanth Aravamudan 301467e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3015a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3016a3437870SNishanth Aravamudan }; 3017a3437870SNishanth Aravamudan 3018094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 30199a305230SLee Schermerhorn struct kobject **hstate_kobjs, 302067e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 3021a3437870SNishanth Aravamudan { 3022a3437870SNishanth Aravamudan int retval; 3023972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 3024a3437870SNishanth Aravamudan 30259a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 30269a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 3027a3437870SNishanth Aravamudan return -ENOMEM; 3028a3437870SNishanth Aravamudan 30299a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 3030a3437870SNishanth Aravamudan if (retval) 30319a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 3032a3437870SNishanth Aravamudan 3033a3437870SNishanth Aravamudan return retval; 3034a3437870SNishanth Aravamudan } 3035a3437870SNishanth Aravamudan 3036a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 3037a3437870SNishanth Aravamudan { 3038a3437870SNishanth Aravamudan struct hstate *h; 3039a3437870SNishanth Aravamudan int err; 3040a3437870SNishanth Aravamudan 3041a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 3042a3437870SNishanth Aravamudan if (!hugepages_kobj) 3043a3437870SNishanth Aravamudan return; 3044a3437870SNishanth Aravamudan 3045a3437870SNishanth Aravamudan for_each_hstate(h) { 30469a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 30479a305230SLee Schermerhorn hstate_kobjs, &hstate_attr_group); 3048a3437870SNishanth Aravamudan if (err) 3049282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s", h->name); 3050a3437870SNishanth Aravamudan } 3051a3437870SNishanth Aravamudan } 3052a3437870SNishanth Aravamudan 30539a305230SLee Schermerhorn #ifdef CONFIG_NUMA 30549a305230SLee Schermerhorn 30559a305230SLee Schermerhorn /* 30569a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 305710fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 305810fbcf4cSKay Sievers * index of a node device or _hstate == node id. 305910fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 30609a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 30619a305230SLee Schermerhorn */ 30629a305230SLee Schermerhorn struct node_hstate { 30639a305230SLee Schermerhorn struct kobject *hugepages_kobj; 30649a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 30659a305230SLee Schermerhorn }; 3066b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 30679a305230SLee Schermerhorn 30689a305230SLee Schermerhorn /* 306910fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 30709a305230SLee Schermerhorn */ 30719a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 30729a305230SLee Schermerhorn &nr_hugepages_attr.attr, 30739a305230SLee Schermerhorn &free_hugepages_attr.attr, 30749a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 30759a305230SLee Schermerhorn NULL, 30769a305230SLee Schermerhorn }; 30779a305230SLee Schermerhorn 307867e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 30799a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 30809a305230SLee Schermerhorn }; 30819a305230SLee Schermerhorn 30829a305230SLee Schermerhorn /* 308310fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 30849a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 30859a305230SLee Schermerhorn */ 30869a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 30879a305230SLee Schermerhorn { 30889a305230SLee Schermerhorn int nid; 30899a305230SLee Schermerhorn 30909a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 30919a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 30929a305230SLee Schermerhorn int i; 30939a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 30949a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 30959a305230SLee Schermerhorn if (nidp) 30969a305230SLee Schermerhorn *nidp = nid; 30979a305230SLee Schermerhorn return &hstates[i]; 30989a305230SLee Schermerhorn } 30999a305230SLee Schermerhorn } 31009a305230SLee Schermerhorn 31019a305230SLee Schermerhorn BUG(); 31029a305230SLee Schermerhorn return NULL; 31039a305230SLee Schermerhorn } 31049a305230SLee Schermerhorn 31059a305230SLee Schermerhorn /* 310610fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 31079a305230SLee Schermerhorn * No-op if no hstate attributes attached. 31089a305230SLee Schermerhorn */ 31093cd8b44fSClaudiu Ghioc static void hugetlb_unregister_node(struct node *node) 31109a305230SLee Schermerhorn { 31119a305230SLee Schermerhorn struct hstate *h; 311210fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 31139a305230SLee Schermerhorn 31149a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 31159b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 31169a305230SLee Schermerhorn 3117972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3118972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 3119972dc4deSAneesh Kumar K.V if (nhs->hstate_kobjs[idx]) { 3120972dc4deSAneesh Kumar K.V kobject_put(nhs->hstate_kobjs[idx]); 3121972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3122972dc4deSAneesh Kumar K.V } 31239a305230SLee Schermerhorn } 31249a305230SLee Schermerhorn 31259a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 31269a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 31279a305230SLee Schermerhorn } 31289a305230SLee Schermerhorn 31299a305230SLee Schermerhorn 31309a305230SLee Schermerhorn /* 313110fbcf4cSKay Sievers * Register hstate attributes for a single node device. 31329a305230SLee Schermerhorn * No-op if attributes already registered. 31339a305230SLee Schermerhorn */ 31343cd8b44fSClaudiu Ghioc static void hugetlb_register_node(struct node *node) 31359a305230SLee Schermerhorn { 31369a305230SLee Schermerhorn struct hstate *h; 313710fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 31389a305230SLee Schermerhorn int err; 31399a305230SLee Schermerhorn 31409a305230SLee Schermerhorn if (nhs->hugepages_kobj) 31419a305230SLee Schermerhorn return; /* already allocated */ 31429a305230SLee Schermerhorn 31439a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 314410fbcf4cSKay Sievers &node->dev.kobj); 31459a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 31469a305230SLee Schermerhorn return; 31479a305230SLee Schermerhorn 31489a305230SLee Schermerhorn for_each_hstate(h) { 31499a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 31509a305230SLee Schermerhorn nhs->hstate_kobjs, 31519a305230SLee Schermerhorn &per_node_hstate_attr_group); 31529a305230SLee Schermerhorn if (err) { 3153282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 315410fbcf4cSKay Sievers h->name, node->dev.id); 31559a305230SLee Schermerhorn hugetlb_unregister_node(node); 31569a305230SLee Schermerhorn break; 31579a305230SLee Schermerhorn } 31589a305230SLee Schermerhorn } 31599a305230SLee Schermerhorn } 31609a305230SLee Schermerhorn 31619a305230SLee Schermerhorn /* 31629b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 316310fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 316410fbcf4cSKay Sievers * registered their associated device by this time. 31659a305230SLee Schermerhorn */ 31667d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 31679a305230SLee Schermerhorn { 31689a305230SLee Schermerhorn int nid; 31699a305230SLee Schermerhorn 31708cebfcd0SLai Jiangshan for_each_node_state(nid, N_MEMORY) { 31718732794bSWen Congyang struct node *node = node_devices[nid]; 317210fbcf4cSKay Sievers if (node->dev.id == nid) 31739a305230SLee Schermerhorn hugetlb_register_node(node); 31749a305230SLee Schermerhorn } 31759a305230SLee Schermerhorn 31769a305230SLee Schermerhorn /* 317710fbcf4cSKay Sievers * Let the node device driver know we're here so it can 31789a305230SLee Schermerhorn * [un]register hstate attributes on node hotplug. 31799a305230SLee Schermerhorn */ 31809a305230SLee Schermerhorn register_hugetlbfs_with_node(hugetlb_register_node, 31819a305230SLee Schermerhorn hugetlb_unregister_node); 31829a305230SLee Schermerhorn } 31839a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 31849a305230SLee Schermerhorn 31859a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 31869a305230SLee Schermerhorn { 31879a305230SLee Schermerhorn BUG(); 31889a305230SLee Schermerhorn if (nidp) 31899a305230SLee Schermerhorn *nidp = -1; 31909a305230SLee Schermerhorn return NULL; 31919a305230SLee Schermerhorn } 31929a305230SLee Schermerhorn 31939a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 31949a305230SLee Schermerhorn 31959a305230SLee Schermerhorn #endif 31969a305230SLee Schermerhorn 3197a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 3198a3437870SNishanth Aravamudan { 31998382d914SDavidlohr Bueso int i; 32008382d914SDavidlohr Bueso 3201c2833a5bSMike Kravetz if (!hugepages_supported()) { 3202c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 3203c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 32040ef89d25SBenjamin Herrenschmidt return 0; 3205d715cf80SLiam R. Howlett } 3206d715cf80SLiam R. Howlett 3207282f4214SMike Kravetz /* 3208282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 3209282f4214SMike Kravetz * architectures depend on setup being done here. 3210282f4214SMike Kravetz */ 3211a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 3212282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 3213282f4214SMike Kravetz /* 3214282f4214SMike Kravetz * If we did not parse a default huge page size, set 3215282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 3216282f4214SMike Kravetz * number of huge pages for this default size was implicitly 3217282f4214SMike Kravetz * specified, set that here as well. 3218282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 3219282f4214SMike Kravetz * setting. A warning will be printed in this case. 3220282f4214SMike Kravetz */ 3221282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 3222f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 3223282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 3224282f4214SMike Kravetz char buf[32]; 3225282f4214SMike Kravetz 3226282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 3227282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 3228282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 3229282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 3230282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 3231282f4214SMike Kravetz default_hstate_max_huge_pages); 3232282f4214SMike Kravetz } 3233282f4214SMike Kravetz default_hstate.max_huge_pages = 3234282f4214SMike Kravetz default_hstate_max_huge_pages; 3235282f4214SMike Kravetz } 3236f8b74815SVaishali Thakkar } 3237a3437870SNishanth Aravamudan 3238cf11e85fSRoman Gushchin hugetlb_cma_check(); 3239a3437870SNishanth Aravamudan hugetlb_init_hstates(); 3240aa888a74SAndi Kleen gather_bootmem_prealloc(); 3241a3437870SNishanth Aravamudan report_hugepages(); 3242a3437870SNishanth Aravamudan 3243a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 32449a305230SLee Schermerhorn hugetlb_register_all_nodes(); 32457179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 32469a305230SLee Schermerhorn 32478382d914SDavidlohr Bueso #ifdef CONFIG_SMP 32488382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 32498382d914SDavidlohr Bueso #else 32508382d914SDavidlohr Bueso num_fault_mutexes = 1; 32518382d914SDavidlohr Bueso #endif 3252c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 32536da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 32546da2ec56SKees Cook GFP_KERNEL); 3255c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 32568382d914SDavidlohr Bueso 32578382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 3258c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 3259a3437870SNishanth Aravamudan return 0; 3260a3437870SNishanth Aravamudan } 32613e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 3262a3437870SNishanth Aravamudan 3263ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 3264ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 32659fee021dSVaishali Thakkar { 3266ae94da89SMike Kravetz return size == HPAGE_SIZE; 32679fee021dSVaishali Thakkar } 32689fee021dSVaishali Thakkar 3269d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 3270a3437870SNishanth Aravamudan { 3271a3437870SNishanth Aravamudan struct hstate *h; 32728faa8b07SAndi Kleen unsigned long i; 32738faa8b07SAndi Kleen 3274a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 3275a3437870SNishanth Aravamudan return; 3276a3437870SNishanth Aravamudan } 327747d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 3278a3437870SNishanth Aravamudan BUG_ON(order == 0); 327947d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 3280a3437870SNishanth Aravamudan h->order = order; 3281a3437870SNishanth Aravamudan h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); 32828faa8b07SAndi Kleen h->nr_huge_pages = 0; 32838faa8b07SAndi Kleen h->free_huge_pages = 0; 32848faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 32858faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 32860edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 328754f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 328854f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 3289a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 3290a3437870SNishanth Aravamudan huge_page_size(h)/1024); 32918faa8b07SAndi Kleen 3292a3437870SNishanth Aravamudan parsed_hstate = h; 3293a3437870SNishanth Aravamudan } 3294a3437870SNishanth Aravamudan 3295282f4214SMike Kravetz /* 3296282f4214SMike Kravetz * hugepages command line processing 3297282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 3298282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 3299282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 3300282f4214SMike Kravetz * specifies the number of huge pages for the default size. 3301282f4214SMike Kravetz */ 3302282f4214SMike Kravetz static int __init hugepages_setup(char *s) 3303a3437870SNishanth Aravamudan { 3304a3437870SNishanth Aravamudan unsigned long *mhp; 33058faa8b07SAndi Kleen static unsigned long *last_mhp; 3306a3437870SNishanth Aravamudan 33079fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 3308282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 33099fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 3310282f4214SMike Kravetz return 0; 33119fee021dSVaishali Thakkar } 3312282f4214SMike Kravetz 3313a3437870SNishanth Aravamudan /* 3314282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 3315282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 3316282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 3317282f4214SMike Kravetz * default_hugepagesz. 3318a3437870SNishanth Aravamudan */ 33199fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 3320a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 3321a3437870SNishanth Aravamudan else 3322a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 3323a3437870SNishanth Aravamudan 33248faa8b07SAndi Kleen if (mhp == last_mhp) { 3325282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 3326282f4214SMike Kravetz return 0; 33278faa8b07SAndi Kleen } 33288faa8b07SAndi Kleen 3329a3437870SNishanth Aravamudan if (sscanf(s, "%lu", mhp) <= 0) 3330a3437870SNishanth Aravamudan *mhp = 0; 3331a3437870SNishanth Aravamudan 33328faa8b07SAndi Kleen /* 33338faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 33348faa8b07SAndi Kleen * But we need to allocate >= MAX_ORDER hstates here early to still 33358faa8b07SAndi Kleen * use the bootmem allocator. 33368faa8b07SAndi Kleen */ 333747d38344SAneesh Kumar K.V if (hugetlb_max_hstate && parsed_hstate->order >= MAX_ORDER) 33388faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 33398faa8b07SAndi Kleen 33408faa8b07SAndi Kleen last_mhp = mhp; 33418faa8b07SAndi Kleen 3342a3437870SNishanth Aravamudan return 1; 3343a3437870SNishanth Aravamudan } 3344282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 3345e11bfbfcSNick Piggin 3346282f4214SMike Kravetz /* 3347282f4214SMike Kravetz * hugepagesz command line processing 3348282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 3349282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 3350282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 3351282f4214SMike Kravetz * hugepagesz argument was valid. 3352282f4214SMike Kravetz */ 3353359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 3354e11bfbfcSNick Piggin { 3355359f2544SMike Kravetz unsigned long size; 3356282f4214SMike Kravetz struct hstate *h; 3357282f4214SMike Kravetz 3358282f4214SMike Kravetz parsed_valid_hugepagesz = false; 3359359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 3360359f2544SMike Kravetz 3361359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 3362282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 3363359f2544SMike Kravetz return 0; 3364359f2544SMike Kravetz } 3365359f2544SMike Kravetz 3366282f4214SMike Kravetz h = size_to_hstate(size); 3367282f4214SMike Kravetz if (h) { 3368282f4214SMike Kravetz /* 3369282f4214SMike Kravetz * hstate for this size already exists. This is normally 3370282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 3371282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 3372282f4214SMike Kravetz * the number of huge pages for the default hstate was not 3373282f4214SMike Kravetz * previously specified. 3374282f4214SMike Kravetz */ 3375282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 3376282f4214SMike Kravetz default_hstate.max_huge_pages) { 3377282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 337838237830SMike Kravetz return 0; 337938237830SMike Kravetz } 338038237830SMike Kravetz 3381282f4214SMike Kravetz /* 3382282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 3383282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 3384282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 3385282f4214SMike Kravetz */ 3386282f4214SMike Kravetz parsed_hstate = h; 3387282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3388e11bfbfcSNick Piggin return 1; 3389e11bfbfcSNick Piggin } 3390282f4214SMike Kravetz 3391359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 3392282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3393359f2544SMike Kravetz return 1; 3394359f2544SMike Kravetz } 3395359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 3396359f2544SMike Kravetz 3397282f4214SMike Kravetz /* 3398282f4214SMike Kravetz * default_hugepagesz command line input 3399282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 3400282f4214SMike Kravetz */ 3401ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 3402e11bfbfcSNick Piggin { 3403ae94da89SMike Kravetz unsigned long size; 3404ae94da89SMike Kravetz 3405282f4214SMike Kravetz parsed_valid_hugepagesz = false; 3406282f4214SMike Kravetz if (parsed_default_hugepagesz) { 3407282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 3408282f4214SMike Kravetz return 0; 3409282f4214SMike Kravetz } 3410282f4214SMike Kravetz 3411282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 3412282f4214SMike Kravetz 3413282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 3414282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 3415282f4214SMike Kravetz return 0; 3416282f4214SMike Kravetz } 3417282f4214SMike Kravetz 3418282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 3419282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3420282f4214SMike Kravetz parsed_default_hugepagesz = true; 3421282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 3422282f4214SMike Kravetz 3423282f4214SMike Kravetz /* 3424282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 3425282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 3426282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 3427282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 3428282f4214SMike Kravetz * allocated here from bootmem allocator. 3429282f4214SMike Kravetz */ 3430282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 3431282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 3432282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 3433282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 3434282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 3435282f4214SMike Kravetz } 3436282f4214SMike Kravetz 3437e11bfbfcSNick Piggin return 1; 3438e11bfbfcSNick Piggin } 3439ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 3440a3437870SNishanth Aravamudan 34418ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 34428a213460SNishanth Aravamudan { 34438a213460SNishanth Aravamudan int node; 34448a213460SNishanth Aravamudan unsigned int nr = 0; 34458ca39e68SMuchun Song nodemask_t *mpol_allowed; 34468ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 34478ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 34488a213460SNishanth Aravamudan 34498ca39e68SMuchun Song mpol_allowed = policy_nodemask_current(gfp_mask); 34508ca39e68SMuchun Song 34518ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 34528ca39e68SMuchun Song if (!mpol_allowed || 34538ca39e68SMuchun Song (mpol_allowed && node_isset(node, *mpol_allowed))) 34548a213460SNishanth Aravamudan nr += array[node]; 34558ca39e68SMuchun Song } 34568a213460SNishanth Aravamudan 34578a213460SNishanth Aravamudan return nr; 34588a213460SNishanth Aravamudan } 34598a213460SNishanth Aravamudan 34608a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 346117743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 346217743798SMuchun Song void *buffer, size_t *length, 346317743798SMuchun Song loff_t *ppos, unsigned long *out) 346417743798SMuchun Song { 346517743798SMuchun Song struct ctl_table dup_table; 346617743798SMuchun Song 346717743798SMuchun Song /* 346817743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 346917743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 347017743798SMuchun Song */ 347117743798SMuchun Song dup_table = *table; 347217743798SMuchun Song dup_table.data = out; 347317743798SMuchun Song 347417743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 347517743798SMuchun Song } 347617743798SMuchun Song 347706808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 347806808b08SLee Schermerhorn struct ctl_table *table, int write, 347932927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 34801da177e4SLinus Torvalds { 3481e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 3482238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 348308d4a246SMichal Hocko int ret; 3484e5ff2159SAndi Kleen 3485457c1b27SNishanth Aravamudan if (!hugepages_supported()) 348686613628SJan Stancek return -EOPNOTSUPP; 3487457c1b27SNishanth Aravamudan 348817743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 348917743798SMuchun Song &tmp); 349008d4a246SMichal Hocko if (ret) 349108d4a246SMichal Hocko goto out; 3492e5ff2159SAndi Kleen 3493238d3c13SDavid Rientjes if (write) 3494238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 3495238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 349608d4a246SMichal Hocko out: 349708d4a246SMichal Hocko return ret; 34981da177e4SLinus Torvalds } 3499396faf03SMel Gorman 350006808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 350132927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 350206808b08SLee Schermerhorn { 350306808b08SLee Schermerhorn 350406808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 350506808b08SLee Schermerhorn buffer, length, ppos); 350606808b08SLee Schermerhorn } 350706808b08SLee Schermerhorn 350806808b08SLee Schermerhorn #ifdef CONFIG_NUMA 350906808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 351032927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 351106808b08SLee Schermerhorn { 351206808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 351306808b08SLee Schermerhorn buffer, length, ppos); 351406808b08SLee Schermerhorn } 351506808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 351606808b08SLee Schermerhorn 3517a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 351832927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 3519a3d0c6aaSNishanth Aravamudan { 3520a5516438SAndi Kleen struct hstate *h = &default_hstate; 3521e5ff2159SAndi Kleen unsigned long tmp; 352208d4a246SMichal Hocko int ret; 3523e5ff2159SAndi Kleen 3524457c1b27SNishanth Aravamudan if (!hugepages_supported()) 352586613628SJan Stancek return -EOPNOTSUPP; 3526457c1b27SNishanth Aravamudan 3527e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 3528e5ff2159SAndi Kleen 3529bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 3530adbe8726SEric B Munson return -EINVAL; 3531adbe8726SEric B Munson 353217743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 353317743798SMuchun Song &tmp); 353408d4a246SMichal Hocko if (ret) 353508d4a246SMichal Hocko goto out; 3536e5ff2159SAndi Kleen 3537e5ff2159SAndi Kleen if (write) { 3538064d9efeSNishanth Aravamudan spin_lock(&hugetlb_lock); 3539e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 3540a3d0c6aaSNishanth Aravamudan spin_unlock(&hugetlb_lock); 3541e5ff2159SAndi Kleen } 354208d4a246SMichal Hocko out: 354308d4a246SMichal Hocko return ret; 3544a3d0c6aaSNishanth Aravamudan } 3545a3d0c6aaSNishanth Aravamudan 35461da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 35471da177e4SLinus Torvalds 3548e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 35491da177e4SLinus Torvalds { 3550fcb2b0c5SRoman Gushchin struct hstate *h; 3551fcb2b0c5SRoman Gushchin unsigned long total = 0; 3552fcb2b0c5SRoman Gushchin 3553457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3554457c1b27SNishanth Aravamudan return; 3555fcb2b0c5SRoman Gushchin 3556fcb2b0c5SRoman Gushchin for_each_hstate(h) { 3557fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 3558fcb2b0c5SRoman Gushchin 3559fcb2b0c5SRoman Gushchin total += (PAGE_SIZE << huge_page_order(h)) * count; 3560fcb2b0c5SRoman Gushchin 3561fcb2b0c5SRoman Gushchin if (h == &default_hstate) 3562e1759c21SAlexey Dobriyan seq_printf(m, 35631da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 35641da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 3565b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 35667893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 35674f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 3568fcb2b0c5SRoman Gushchin count, 3569a5516438SAndi Kleen h->free_huge_pages, 3570a5516438SAndi Kleen h->resv_huge_pages, 3571a5516438SAndi Kleen h->surplus_huge_pages, 3572fcb2b0c5SRoman Gushchin (PAGE_SIZE << huge_page_order(h)) / 1024); 3573fcb2b0c5SRoman Gushchin } 3574fcb2b0c5SRoman Gushchin 3575fcb2b0c5SRoman Gushchin seq_printf(m, "Hugetlb: %8lu kB\n", total / 1024); 35761da177e4SLinus Torvalds } 35771da177e4SLinus Torvalds 35781da177e4SLinus Torvalds int hugetlb_report_node_meminfo(int nid, char *buf) 35791da177e4SLinus Torvalds { 3580a5516438SAndi Kleen struct hstate *h = &default_hstate; 3581457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3582457c1b27SNishanth Aravamudan return 0; 35831da177e4SLinus Torvalds return sprintf(buf, 35841da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 3585a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 3586a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 3587a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 3588a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 3589a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 35901da177e4SLinus Torvalds } 35911da177e4SLinus Torvalds 3592949f7ec5SDavid Rientjes void hugetlb_show_meminfo(void) 3593949f7ec5SDavid Rientjes { 3594949f7ec5SDavid Rientjes struct hstate *h; 3595949f7ec5SDavid Rientjes int nid; 3596949f7ec5SDavid Rientjes 3597457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3598457c1b27SNishanth Aravamudan return; 3599457c1b27SNishanth Aravamudan 3600949f7ec5SDavid Rientjes for_each_node_state(nid, N_MEMORY) 3601949f7ec5SDavid Rientjes for_each_hstate(h) 3602949f7ec5SDavid Rientjes pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 3603949f7ec5SDavid Rientjes nid, 3604949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 3605949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 3606949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 3607949f7ec5SDavid Rientjes 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); 3608949f7ec5SDavid Rientjes } 3609949f7ec5SDavid Rientjes 36105d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 36115d317b2bSNaoya Horiguchi { 36125d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 36135d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 36145d317b2bSNaoya Horiguchi } 36155d317b2bSNaoya Horiguchi 36161da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 36171da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 36181da177e4SLinus Torvalds { 3619d0028588SWanpeng Li struct hstate *h; 3620d0028588SWanpeng Li unsigned long nr_total_pages = 0; 3621d0028588SWanpeng Li 3622d0028588SWanpeng Li for_each_hstate(h) 3623d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 3624d0028588SWanpeng Li return nr_total_pages; 36251da177e4SLinus Torvalds } 36261da177e4SLinus Torvalds 3627a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 3628fc1b8a73SMel Gorman { 3629fc1b8a73SMel Gorman int ret = -ENOMEM; 3630fc1b8a73SMel Gorman 3631fc1b8a73SMel Gorman spin_lock(&hugetlb_lock); 3632fc1b8a73SMel Gorman /* 3633fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 3634fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 3635fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 3636fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 3637fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 3638fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 3639fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 3640fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 3641fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 3642fc1b8a73SMel Gorman * 3643fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 3644fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 3645fc1b8a73SMel Gorman * we fall back to check against current free page availability as 3646fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 3647fc1b8a73SMel Gorman * semantics that cpuset has. 36488ca39e68SMuchun Song * 36498ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 36508ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 36518ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 36528ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 36538ca39e68SMuchun Song * above. 3654fc1b8a73SMel Gorman */ 3655fc1b8a73SMel Gorman if (delta > 0) { 3656a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 3657fc1b8a73SMel Gorman goto out; 3658fc1b8a73SMel Gorman 36598ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 3660a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 3661fc1b8a73SMel Gorman goto out; 3662fc1b8a73SMel Gorman } 3663fc1b8a73SMel Gorman } 3664fc1b8a73SMel Gorman 3665fc1b8a73SMel Gorman ret = 0; 3666fc1b8a73SMel Gorman if (delta < 0) 3667a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 3668fc1b8a73SMel Gorman 3669fc1b8a73SMel Gorman out: 3670fc1b8a73SMel Gorman spin_unlock(&hugetlb_lock); 3671fc1b8a73SMel Gorman return ret; 3672fc1b8a73SMel Gorman } 3673fc1b8a73SMel Gorman 367484afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 367584afd99bSAndy Whitcroft { 3676f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 367784afd99bSAndy Whitcroft 367884afd99bSAndy Whitcroft /* 367984afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 368084afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 368184afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 368225985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 368384afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 368484afd99bSAndy Whitcroft * new reference here without additional locking. 368584afd99bSAndy Whitcroft */ 36864e35f483SJoonsoo Kim if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 3687f522c3acSJoonsoo Kim kref_get(&resv->refs); 368884afd99bSAndy Whitcroft } 368984afd99bSAndy Whitcroft 3690a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 3691a1e78772SMel Gorman { 3692a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3693f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 369490481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 36954e35f483SJoonsoo Kim unsigned long reserve, start, end; 36961c5ecae3SMike Kravetz long gbl_reserve; 369784afd99bSAndy Whitcroft 36984e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 36994e35f483SJoonsoo Kim return; 37004e35f483SJoonsoo Kim 3701a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 3702a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 370384afd99bSAndy Whitcroft 37044e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 3705e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 37067251ff78SAdam Litke if (reserve) { 37071c5ecae3SMike Kravetz /* 37081c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 37091c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 37101c5ecae3SMike Kravetz */ 37111c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 37121c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 37137251ff78SAdam Litke } 3714e9fe92aeSMina Almasry 3715e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 3716a1e78772SMel Gorman } 3717a1e78772SMel Gorman 371831383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 371931383c68SDan Williams { 372031383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 372131383c68SDan Williams return -EINVAL; 372231383c68SDan Williams return 0; 372331383c68SDan Williams } 372431383c68SDan Williams 372505ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 372605ea8860SDan Williams { 372705ea8860SDan Williams struct hstate *hstate = hstate_vma(vma); 372805ea8860SDan Williams 372905ea8860SDan Williams return 1UL << huge_page_shift(hstate); 373005ea8860SDan Williams } 373105ea8860SDan Williams 37321da177e4SLinus Torvalds /* 37331da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 37341da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 37351da177e4SLinus Torvalds * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get 37361da177e4SLinus Torvalds * this far. 37371da177e4SLinus Torvalds */ 3738b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 37391da177e4SLinus Torvalds { 37401da177e4SLinus Torvalds BUG(); 3741d0217ac0SNick Piggin return 0; 37421da177e4SLinus Torvalds } 37431da177e4SLinus Torvalds 3744eec3636aSJane Chu /* 3745eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 3746eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 3747eec3636aSJane Chu * This is because under System V memory model, mappings created via 3748eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 3749eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 3750eec3636aSJane Chu */ 3751f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 3752d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 375384afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 3754a1e78772SMel Gorman .close = hugetlb_vm_op_close, 375531383c68SDan Williams .split = hugetlb_vm_op_split, 375605ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 37571da177e4SLinus Torvalds }; 37581da177e4SLinus Torvalds 37591e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 37601e8f889bSDavid Gibson int writable) 376163551ae0SDavid Gibson { 376263551ae0SDavid Gibson pte_t entry; 376363551ae0SDavid Gibson 37641e8f889bSDavid Gibson if (writable) { 3765106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 3766106c992aSGerald Schaefer vma->vm_page_prot))); 376763551ae0SDavid Gibson } else { 3768106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 3769106c992aSGerald Schaefer vma->vm_page_prot)); 377063551ae0SDavid Gibson } 377163551ae0SDavid Gibson entry = pte_mkyoung(entry); 377263551ae0SDavid Gibson entry = pte_mkhuge(entry); 3773d9ed9faaSChris Metcalf entry = arch_make_huge_pte(entry, vma, page, writable); 377463551ae0SDavid Gibson 377563551ae0SDavid Gibson return entry; 377663551ae0SDavid Gibson } 377763551ae0SDavid Gibson 37781e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 37791e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 37801e8f889bSDavid Gibson { 37811e8f889bSDavid Gibson pte_t entry; 37821e8f889bSDavid Gibson 3783106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 378432f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 37854b3073e1SRussell King update_mmu_cache(vma, address, ptep); 37861e8f889bSDavid Gibson } 37871e8f889bSDavid Gibson 3788d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 37894a705fefSNaoya Horiguchi { 37904a705fefSNaoya Horiguchi swp_entry_t swp; 37914a705fefSNaoya Horiguchi 37924a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 3793d5ed7444SAneesh Kumar K.V return false; 37944a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 3795d79d176aSBaoquan He if (is_migration_entry(swp)) 3796d5ed7444SAneesh Kumar K.V return true; 37974a705fefSNaoya Horiguchi else 3798d5ed7444SAneesh Kumar K.V return false; 37994a705fefSNaoya Horiguchi } 38004a705fefSNaoya Horiguchi 38013e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 38024a705fefSNaoya Horiguchi { 38034a705fefSNaoya Horiguchi swp_entry_t swp; 38044a705fefSNaoya Horiguchi 38054a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 38063e5c3600SBaoquan He return false; 38074a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 3808d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 38093e5c3600SBaoquan He return true; 38104a705fefSNaoya Horiguchi else 38113e5c3600SBaoquan He return false; 38124a705fefSNaoya Horiguchi } 38131e8f889bSDavid Gibson 381463551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 381563551ae0SDavid Gibson struct vm_area_struct *vma) 381663551ae0SDavid Gibson { 38175e41540cSMike Kravetz pte_t *src_pte, *dst_pte, entry, dst_entry; 381863551ae0SDavid Gibson struct page *ptepage; 38191c59827dSHugh Dickins unsigned long addr; 38201e8f889bSDavid Gibson int cow; 3821a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3822a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 3823c0d0381aSMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 3824ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 3825e8569dd2SAndreas Sandberg int ret = 0; 38261e8f889bSDavid Gibson 38271e8f889bSDavid Gibson cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 382863551ae0SDavid Gibson 3829ac46d4f3SJérôme Glisse if (cow) { 38307269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, src, 38316f4f13e8SJérôme Glisse vma->vm_start, 3832ac46d4f3SJérôme Glisse vma->vm_end); 3833ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 3834c0d0381aSMike Kravetz } else { 3835c0d0381aSMike Kravetz /* 3836c0d0381aSMike Kravetz * For shared mappings i_mmap_rwsem must be held to call 3837c0d0381aSMike Kravetz * huge_pte_alloc, otherwise the returned ptep could go 3838c0d0381aSMike Kravetz * away if part of a shared pmd and another thread calls 3839c0d0381aSMike Kravetz * huge_pmd_unshare. 3840c0d0381aSMike Kravetz */ 3841c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 3842ac46d4f3SJérôme Glisse } 3843e8569dd2SAndreas Sandberg 3844a5516438SAndi Kleen for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { 3845cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 38467868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 3847c74df32cSHugh Dickins if (!src_pte) 3848c74df32cSHugh Dickins continue; 3849a5516438SAndi Kleen dst_pte = huge_pte_alloc(dst, addr, sz); 3850e8569dd2SAndreas Sandberg if (!dst_pte) { 3851e8569dd2SAndreas Sandberg ret = -ENOMEM; 3852e8569dd2SAndreas Sandberg break; 3853e8569dd2SAndreas Sandberg } 3854c5c99429SLarry Woodman 38555e41540cSMike Kravetz /* 38565e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 38575e41540cSMike Kravetz * dst_pte == src_pte is the common case of src/dest sharing. 38585e41540cSMike Kravetz * 38595e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 38605e41540cSMike Kravetz * another vma. If dst_pte !none, this implies sharing. 38615e41540cSMike Kravetz * Check here before taking page table lock, and once again 38625e41540cSMike Kravetz * after taking the lock below. 38635e41540cSMike Kravetz */ 38645e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 38655e41540cSMike Kravetz if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) 3866c5c99429SLarry Woodman continue; 3867c5c99429SLarry Woodman 3868cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 3869cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 3870cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 38714a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 38725e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 38735e41540cSMike Kravetz if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { 38745e41540cSMike Kravetz /* 38755e41540cSMike Kravetz * Skip if src entry none. Also, skip in the 38765e41540cSMike Kravetz * unlikely case dst entry !none as this implies 38775e41540cSMike Kravetz * sharing with another vma. 38785e41540cSMike Kravetz */ 38794a705fefSNaoya Horiguchi ; 38804a705fefSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry) || 38814a705fefSNaoya Horiguchi is_hugetlb_entry_hwpoisoned(entry))) { 38824a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 38834a705fefSNaoya Horiguchi 38844a705fefSNaoya Horiguchi if (is_write_migration_entry(swp_entry) && cow) { 38854a705fefSNaoya Horiguchi /* 38864a705fefSNaoya Horiguchi * COW mappings require pages in both 38874a705fefSNaoya Horiguchi * parent and child to be set to read. 38884a705fefSNaoya Horiguchi */ 38894a705fefSNaoya Horiguchi make_migration_entry_read(&swp_entry); 38904a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 3891e5251fd4SPunit Agrawal set_huge_swap_pte_at(src, addr, src_pte, 3892e5251fd4SPunit Agrawal entry, sz); 38934a705fefSNaoya Horiguchi } 3894e5251fd4SPunit Agrawal set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz); 38954a705fefSNaoya Horiguchi } else { 389634ee645eSJoerg Roedel if (cow) { 38970f10851eSJérôme Glisse /* 38980f10851eSJérôme Glisse * No need to notify as we are downgrading page 38990f10851eSJérôme Glisse * table protection not changing it to point 39000f10851eSJérôme Glisse * to a new page. 39010f10851eSJérôme Glisse * 3902ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 39030f10851eSJérôme Glisse */ 39047f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 390534ee645eSJoerg Roedel } 39060253d634SNaoya Horiguchi entry = huge_ptep_get(src_pte); 390763551ae0SDavid Gibson ptepage = pte_page(entry); 390863551ae0SDavid Gibson get_page(ptepage); 390953f9263bSKirill A. Shutemov page_dup_rmap(ptepage, true); 391063551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 39115d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), dst); 39121c59827dSHugh Dickins } 3913cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 3914cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 391563551ae0SDavid Gibson } 391663551ae0SDavid Gibson 3917e8569dd2SAndreas Sandberg if (cow) 3918ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 3919c0d0381aSMike Kravetz else 3920c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 3921e8569dd2SAndreas Sandberg 3922e8569dd2SAndreas Sandberg return ret; 392363551ae0SDavid Gibson } 392463551ae0SDavid Gibson 392524669e58SAneesh Kumar K.V void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 392624669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 392724669e58SAneesh Kumar K.V struct page *ref_page) 392863551ae0SDavid Gibson { 392963551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 393063551ae0SDavid Gibson unsigned long address; 3931c7546f8fSDavid Gibson pte_t *ptep; 393263551ae0SDavid Gibson pte_t pte; 3933cb900f41SKirill A. Shutemov spinlock_t *ptl; 393463551ae0SDavid Gibson struct page *page; 3935a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3936a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 3937ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 3938a5516438SAndi Kleen 393963551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 3940a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 3941a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 394263551ae0SDavid Gibson 394307e32661SAneesh Kumar K.V /* 394407e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 394507e32661SAneesh Kumar K.V * to huge page. 394607e32661SAneesh Kumar K.V */ 3947ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 394824669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 3949dff11abeSMike Kravetz 3950dff11abeSMike Kravetz /* 3951dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 3952dff11abeSMike Kravetz */ 39536f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 39546f4f13e8SJérôme Glisse end); 3955ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 3956ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 3957569f48b8SHillf Danton address = start; 3958569f48b8SHillf Danton for (; address < end; address += sz) { 39597868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 3960c7546f8fSDavid Gibson if (!ptep) 3961c7546f8fSDavid Gibson continue; 3962c7546f8fSDavid Gibson 3963cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 396434ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 396531d49da5SAneesh Kumar K.V spin_unlock(ptl); 3966dff11abeSMike Kravetz /* 3967dff11abeSMike Kravetz * We just unmapped a page of PMDs by clearing a PUD. 3968dff11abeSMike Kravetz * The caller's TLB flush range should cover this area. 3969dff11abeSMike Kravetz */ 397031d49da5SAneesh Kumar K.V continue; 397131d49da5SAneesh Kumar K.V } 397239dde65cSChen, Kenneth W 39736629326bSHillf Danton pte = huge_ptep_get(ptep); 397431d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 397531d49da5SAneesh Kumar K.V spin_unlock(ptl); 397631d49da5SAneesh Kumar K.V continue; 397731d49da5SAneesh Kumar K.V } 39786629326bSHillf Danton 39796629326bSHillf Danton /* 39809fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 39819fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 39826629326bSHillf Danton */ 39839fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 39849386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 398531d49da5SAneesh Kumar K.V spin_unlock(ptl); 398631d49da5SAneesh Kumar K.V continue; 39878c4894c6SNaoya Horiguchi } 39886629326bSHillf Danton 39896629326bSHillf Danton page = pte_page(pte); 399004f2cbe3SMel Gorman /* 399104f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 399204f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 399304f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 399404f2cbe3SMel Gorman */ 399504f2cbe3SMel Gorman if (ref_page) { 399631d49da5SAneesh Kumar K.V if (page != ref_page) { 399731d49da5SAneesh Kumar K.V spin_unlock(ptl); 399831d49da5SAneesh Kumar K.V continue; 399931d49da5SAneesh Kumar K.V } 400004f2cbe3SMel Gorman /* 400104f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 400204f2cbe3SMel Gorman * future faults in this VMA will fail rather than 400304f2cbe3SMel Gorman * looking like data was lost 400404f2cbe3SMel Gorman */ 400504f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 400604f2cbe3SMel Gorman } 400704f2cbe3SMel Gorman 4008c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 4009b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 4010106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 40116649a386SKen Chen set_page_dirty(page); 40129e81130bSHillf Danton 40135d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 4014d281ee61SKirill A. Shutemov page_remove_rmap(page, true); 401531d49da5SAneesh Kumar K.V 4016cb900f41SKirill A. Shutemov spin_unlock(ptl); 4017e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 401824669e58SAneesh Kumar K.V /* 401931d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 402024669e58SAneesh Kumar K.V */ 402131d49da5SAneesh Kumar K.V if (ref_page) 402231d49da5SAneesh Kumar K.V break; 4023fe1668aeSChen, Kenneth W } 4024ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 402524669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 40261da177e4SLinus Torvalds } 402763551ae0SDavid Gibson 4028d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 4029d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 4030d833352aSMel Gorman unsigned long end, struct page *ref_page) 4031d833352aSMel Gorman { 4032d833352aSMel Gorman __unmap_hugepage_range(tlb, vma, start, end, ref_page); 4033d833352aSMel Gorman 4034d833352aSMel Gorman /* 4035d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 4036d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 4037d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 4038d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 4039d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 4040c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 4041d833352aSMel Gorman * because in the context this is called, the VMA is about to be 4042c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 4043d833352aSMel Gorman */ 4044d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 4045d833352aSMel Gorman } 4046d833352aSMel Gorman 4047502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 404804f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 4049502717f4SChen, Kenneth W { 405024669e58SAneesh Kumar K.V struct mm_struct *mm; 405124669e58SAneesh Kumar K.V struct mmu_gather tlb; 4052dff11abeSMike Kravetz unsigned long tlb_start = start; 4053dff11abeSMike Kravetz unsigned long tlb_end = end; 4054dff11abeSMike Kravetz 4055dff11abeSMike Kravetz /* 4056dff11abeSMike Kravetz * If shared PMDs were possibly used within this vma range, adjust 4057dff11abeSMike Kravetz * start/end for worst case tlb flushing. 4058dff11abeSMike Kravetz * Note that we can not be sure if PMDs are shared until we try to 4059dff11abeSMike Kravetz * unmap pages. However, we want to make sure TLB flushing covers 4060dff11abeSMike Kravetz * the largest possible range. 4061dff11abeSMike Kravetz */ 4062dff11abeSMike Kravetz adjust_range_if_pmd_sharing_possible(vma, &tlb_start, &tlb_end); 406324669e58SAneesh Kumar K.V 406424669e58SAneesh Kumar K.V mm = vma->vm_mm; 406524669e58SAneesh Kumar K.V 4066dff11abeSMike Kravetz tlb_gather_mmu(&tlb, mm, tlb_start, tlb_end); 406724669e58SAneesh Kumar K.V __unmap_hugepage_range(&tlb, vma, start, end, ref_page); 4068dff11abeSMike Kravetz tlb_finish_mmu(&tlb, tlb_start, tlb_end); 4069502717f4SChen, Kenneth W } 4070502717f4SChen, Kenneth W 407104f2cbe3SMel Gorman /* 407204f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 407304f2cbe3SMel Gorman * mappping it owns the reserve page for. The intention is to unmap the page 407404f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 407504f2cbe3SMel Gorman * same region. 407604f2cbe3SMel Gorman */ 40772f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 40782a4b3dedSHarvey Harrison struct page *page, unsigned long address) 407904f2cbe3SMel Gorman { 40807526674dSAdam Litke struct hstate *h = hstate_vma(vma); 408104f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 408204f2cbe3SMel Gorman struct address_space *mapping; 408304f2cbe3SMel Gorman pgoff_t pgoff; 408404f2cbe3SMel Gorman 408504f2cbe3SMel Gorman /* 408604f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 408704f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 408804f2cbe3SMel Gorman */ 40897526674dSAdam Litke address = address & huge_page_mask(h); 409036e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 409136e4f20aSMichal Hocko vma->vm_pgoff; 409293c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 409304f2cbe3SMel Gorman 40944eb2b1dcSMel Gorman /* 40954eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 40964eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 40974eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 40984eb2b1dcSMel Gorman */ 409983cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 41006b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 410104f2cbe3SMel Gorman /* Do not unmap the current VMA */ 410204f2cbe3SMel Gorman if (iter_vma == vma) 410304f2cbe3SMel Gorman continue; 410404f2cbe3SMel Gorman 410504f2cbe3SMel Gorman /* 41062f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 41072f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 41082f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 41092f84a899SMel Gorman */ 41102f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 41112f84a899SMel Gorman continue; 41122f84a899SMel Gorman 41132f84a899SMel Gorman /* 411404f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 411504f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 411604f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 411704f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 411804f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 411904f2cbe3SMel Gorman */ 412004f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 412124669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 412224669e58SAneesh Kumar K.V address + huge_page_size(h), page); 412304f2cbe3SMel Gorman } 412483cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 412504f2cbe3SMel Gorman } 412604f2cbe3SMel Gorman 41270fe6e20bSNaoya Horiguchi /* 41280fe6e20bSNaoya Horiguchi * Hugetlb_cow() should be called with page lock of the original hugepage held. 4129ef009b25SMichal Hocko * Called with hugetlb_instantiation_mutex held and pte_page locked so we 4130ef009b25SMichal Hocko * cannot race with other handlers or page migration. 4131ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 41320fe6e20bSNaoya Horiguchi */ 41332b740303SSouptick Joarder static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, 4134974e6d66SHuang Ying unsigned long address, pte_t *ptep, 4135cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 41361e8f889bSDavid Gibson { 41373999f52eSAneesh Kumar K.V pte_t pte; 4138a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 41391e8f889bSDavid Gibson struct page *old_page, *new_page; 41402b740303SSouptick Joarder int outside_reserve = 0; 41412b740303SSouptick Joarder vm_fault_t ret = 0; 4142974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 4143ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 41441e8f889bSDavid Gibson 41453999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 41461e8f889bSDavid Gibson old_page = pte_page(pte); 41471e8f889bSDavid Gibson 414804f2cbe3SMel Gorman retry_avoidcopy: 41491e8f889bSDavid Gibson /* If no-one else is actually using this page, avoid the copy 41501e8f889bSDavid Gibson * and just make the page writable */ 415137a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 41525a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 41535b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 415483c54070SNick Piggin return 0; 41551e8f889bSDavid Gibson } 41561e8f889bSDavid Gibson 415704f2cbe3SMel Gorman /* 415804f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 415904f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 416004f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 416104f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 416204f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 416304f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 416404f2cbe3SMel Gorman * of the full address range. 416504f2cbe3SMel Gorman */ 41665944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 416704f2cbe3SMel Gorman old_page != pagecache_page) 416804f2cbe3SMel Gorman outside_reserve = 1; 416904f2cbe3SMel Gorman 417009cbfeafSKirill A. Shutemov get_page(old_page); 4171b76c8cfbSLarry Woodman 4172ad4404a2SDavidlohr Bueso /* 4173ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 4174ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 4175ad4404a2SDavidlohr Bueso */ 4176cb900f41SKirill A. Shutemov spin_unlock(ptl); 41775b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 41781e8f889bSDavid Gibson 41792fc39cecSAdam Litke if (IS_ERR(new_page)) { 418004f2cbe3SMel Gorman /* 418104f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 418204f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 418304f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 418404f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 418504f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 418604f2cbe3SMel Gorman */ 418704f2cbe3SMel Gorman if (outside_reserve) { 418809cbfeafSKirill A. Shutemov put_page(old_page); 418904f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 41905b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 419104f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 4192cb900f41SKirill A. Shutemov spin_lock(ptl); 41935b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4194a9af0c5dSNaoya Horiguchi if (likely(ptep && 4195a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 419604f2cbe3SMel Gorman goto retry_avoidcopy; 4197a734bcc8SHillf Danton /* 4198cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 4199cb900f41SKirill A. Shutemov * lock, and our job is done. 4200a734bcc8SHillf Danton */ 4201a734bcc8SHillf Danton return 0; 420204f2cbe3SMel Gorman } 420304f2cbe3SMel Gorman 42042b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 4205ad4404a2SDavidlohr Bueso goto out_release_old; 42061e8f889bSDavid Gibson } 42071e8f889bSDavid Gibson 42080fe6e20bSNaoya Horiguchi /* 42090fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 42100fe6e20bSNaoya Horiguchi * anon_vma prepared. 42110fe6e20bSNaoya Horiguchi */ 421244e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 4213ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 4214ad4404a2SDavidlohr Bueso goto out_release_all; 421544e2aa93SDean Nelson } 42160fe6e20bSNaoya Horiguchi 4217974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 421847ad8475SAndrea Arcangeli pages_per_huge_page(h)); 42190ed361deSNick Piggin __SetPageUptodate(new_page); 42201e8f889bSDavid Gibson 42217269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 42226f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 4223ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4224ad4404a2SDavidlohr Bueso 4225b76c8cfbSLarry Woodman /* 4226cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 4227b76c8cfbSLarry Woodman * before the page tables are altered 4228b76c8cfbSLarry Woodman */ 4229cb900f41SKirill A. Shutemov spin_lock(ptl); 42305b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4231a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 423207443a85SJoonsoo Kim ClearPagePrivate(new_page); 423307443a85SJoonsoo Kim 42341e8f889bSDavid Gibson /* Break COW */ 42355b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 4236ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 42375b7a1d40SHuang Ying set_huge_pte_at(mm, haddr, ptep, 42381e8f889bSDavid Gibson make_huge_pte(vma, new_page, 1)); 4239d281ee61SKirill A. Shutemov page_remove_rmap(old_page, true); 42405b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 4241cb6acd01SMike Kravetz set_page_huge_active(new_page); 42421e8f889bSDavid Gibson /* Make the old page be freed below */ 42431e8f889bSDavid Gibson new_page = old_page; 42441e8f889bSDavid Gibson } 4245cb900f41SKirill A. Shutemov spin_unlock(ptl); 4246ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4247ad4404a2SDavidlohr Bueso out_release_all: 42485b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 424909cbfeafSKirill A. Shutemov put_page(new_page); 4250ad4404a2SDavidlohr Bueso out_release_old: 425109cbfeafSKirill A. Shutemov put_page(old_page); 42528312034fSJoonsoo Kim 4253ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 4254ad4404a2SDavidlohr Bueso return ret; 42551e8f889bSDavid Gibson } 42561e8f889bSDavid Gibson 425704f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 4258a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 4259a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 426004f2cbe3SMel Gorman { 426104f2cbe3SMel Gorman struct address_space *mapping; 4262e7c4b0bfSAndy Whitcroft pgoff_t idx; 426304f2cbe3SMel Gorman 426404f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 4265a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 426604f2cbe3SMel Gorman 426704f2cbe3SMel Gorman return find_lock_page(mapping, idx); 426804f2cbe3SMel Gorman } 426904f2cbe3SMel Gorman 42703ae77f43SHugh Dickins /* 42713ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 42723ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 42733ae77f43SHugh Dickins */ 42743ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 42752a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 42762a15efc9SHugh Dickins { 42772a15efc9SHugh Dickins struct address_space *mapping; 42782a15efc9SHugh Dickins pgoff_t idx; 42792a15efc9SHugh Dickins struct page *page; 42802a15efc9SHugh Dickins 42812a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 42822a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 42832a15efc9SHugh Dickins 42842a15efc9SHugh Dickins page = find_get_page(mapping, idx); 42852a15efc9SHugh Dickins if (page) 42862a15efc9SHugh Dickins put_page(page); 42872a15efc9SHugh Dickins return page != NULL; 42882a15efc9SHugh Dickins } 42892a15efc9SHugh Dickins 4290ab76ad54SMike Kravetz int huge_add_to_page_cache(struct page *page, struct address_space *mapping, 4291ab76ad54SMike Kravetz pgoff_t idx) 4292ab76ad54SMike Kravetz { 4293ab76ad54SMike Kravetz struct inode *inode = mapping->host; 4294ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 4295ab76ad54SMike Kravetz int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 4296ab76ad54SMike Kravetz 4297ab76ad54SMike Kravetz if (err) 4298ab76ad54SMike Kravetz return err; 4299ab76ad54SMike Kravetz ClearPagePrivate(page); 4300ab76ad54SMike Kravetz 430122146c3cSMike Kravetz /* 430222146c3cSMike Kravetz * set page dirty so that it will not be removed from cache/file 430322146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 430422146c3cSMike Kravetz */ 430522146c3cSMike Kravetz set_page_dirty(page); 430622146c3cSMike Kravetz 4307ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 4308ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 4309ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 4310ab76ad54SMike Kravetz return 0; 4311ab76ad54SMike Kravetz } 4312ab76ad54SMike Kravetz 43132b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 43142b740303SSouptick Joarder struct vm_area_struct *vma, 43158382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 4316788c7df4SHugh Dickins unsigned long address, pte_t *ptep, unsigned int flags) 4317ac9b9c66SHugh Dickins { 4318a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 43192b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 4320409eb8c2SHillf Danton int anon_rmap = 0; 43214c887265SAdam Litke unsigned long size; 43224c887265SAdam Litke struct page *page; 43231e8f889bSDavid Gibson pte_t new_pte; 4324cb900f41SKirill A. Shutemov spinlock_t *ptl; 4325285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 4326cb6acd01SMike Kravetz bool new_page = false; 43274c887265SAdam Litke 432804f2cbe3SMel Gorman /* 432904f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 433004f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 433125985edcSLucas De Marchi * COW. Warn that such a situation has occurred as it may not be obvious 433204f2cbe3SMel Gorman */ 433304f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 4334910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 433504f2cbe3SMel Gorman current->pid); 433604f2cbe3SMel Gorman return ret; 433704f2cbe3SMel Gorman } 433804f2cbe3SMel Gorman 43394c887265SAdam Litke /* 434087bf91d3SMike Kravetz * We can not race with truncation due to holding i_mmap_rwsem. 434187bf91d3SMike Kravetz * i_size is modified when holding i_mmap_rwsem, so check here 434287bf91d3SMike Kravetz * once for faults beyond end of file. 43434c887265SAdam Litke */ 4344a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 4345ebed4bfcSHugh Dickins if (idx >= size) 4346ebed4bfcSHugh Dickins goto out; 43471a1aad8aSMike Kravetz 434887bf91d3SMike Kravetz retry: 434987bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 435087bf91d3SMike Kravetz if (!page) { 43511a1aad8aSMike Kravetz /* 43521a1aad8aSMike Kravetz * Check for page in userfault range 43531a1aad8aSMike Kravetz */ 43541a1aad8aSMike Kravetz if (userfaultfd_missing(vma)) { 43551a1aad8aSMike Kravetz u32 hash; 43561a1aad8aSMike Kravetz struct vm_fault vmf = { 43571a1aad8aSMike Kravetz .vma = vma, 4358285b8dcaSHuang Ying .address = haddr, 43591a1aad8aSMike Kravetz .flags = flags, 43601a1aad8aSMike Kravetz /* 43611a1aad8aSMike Kravetz * Hard to debug if it ends up being 43621a1aad8aSMike Kravetz * used by a callee that assumes 43631a1aad8aSMike Kravetz * something about the other 43641a1aad8aSMike Kravetz * uninitialized fields... same as in 43651a1aad8aSMike Kravetz * memory.c 43661a1aad8aSMike Kravetz */ 43671a1aad8aSMike Kravetz }; 43681a1aad8aSMike Kravetz 43691a1aad8aSMike Kravetz /* 4370c0d0381aSMike Kravetz * hugetlb_fault_mutex and i_mmap_rwsem must be 4371c0d0381aSMike Kravetz * dropped before handling userfault. Reacquire 4372c0d0381aSMike Kravetz * after handling fault to make calling code simpler. 43731a1aad8aSMike Kravetz */ 4374188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 43751a1aad8aSMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 4376c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 43771a1aad8aSMike Kravetz ret = handle_userfault(&vmf, VM_UFFD_MISSING); 4378c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 43791a1aad8aSMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 43801a1aad8aSMike Kravetz goto out; 43811a1aad8aSMike Kravetz } 43821a1aad8aSMike Kravetz 4383285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 43842fc39cecSAdam Litke if (IS_ERR(page)) { 43854643d67eSMike Kravetz /* 43864643d67eSMike Kravetz * Returning error will result in faulting task being 43874643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 43884643d67eSMike Kravetz * tasks from racing to fault in the same page which 43894643d67eSMike Kravetz * could result in false unable to allocate errors. 43904643d67eSMike Kravetz * Page migration does not take the fault mutex, but 43914643d67eSMike Kravetz * does a clear then write of pte's under page table 43924643d67eSMike Kravetz * lock. Page fault code could race with migration, 43934643d67eSMike Kravetz * notice the clear pte and try to allocate a page 43944643d67eSMike Kravetz * here. Before returning error, get ptl and make 43954643d67eSMike Kravetz * sure there really is no pte entry. 43964643d67eSMike Kravetz */ 43974643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 43984643d67eSMike Kravetz if (!huge_pte_none(huge_ptep_get(ptep))) { 43994643d67eSMike Kravetz ret = 0; 44004643d67eSMike Kravetz spin_unlock(ptl); 44014643d67eSMike Kravetz goto out; 44024643d67eSMike Kravetz } 44034643d67eSMike Kravetz spin_unlock(ptl); 44042b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 44056bda666aSChristoph Lameter goto out; 44066bda666aSChristoph Lameter } 440747ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 44080ed361deSNick Piggin __SetPageUptodate(page); 4409cb6acd01SMike Kravetz new_page = true; 4410ac9b9c66SHugh Dickins 4411f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 4412ab76ad54SMike Kravetz int err = huge_add_to_page_cache(page, mapping, idx); 44136bda666aSChristoph Lameter if (err) { 44146bda666aSChristoph Lameter put_page(page); 44156bda666aSChristoph Lameter if (err == -EEXIST) 44166bda666aSChristoph Lameter goto retry; 44176bda666aSChristoph Lameter goto out; 44186bda666aSChristoph Lameter } 441923be7468SMel Gorman } else { 44206bda666aSChristoph Lameter lock_page(page); 44210fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 44220fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 44230fe6e20bSNaoya Horiguchi goto backout_unlocked; 442423be7468SMel Gorman } 4425409eb8c2SHillf Danton anon_rmap = 1; 44260fe6e20bSNaoya Horiguchi } 44270fe6e20bSNaoya Horiguchi } else { 442857303d80SAndy Whitcroft /* 4429998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 4430998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 4431998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 4432fd6a03edSNaoya Horiguchi */ 4433fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 4434aa50d3a7SAndi Kleen ret = VM_FAULT_HWPOISON | 4435972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 4436fd6a03edSNaoya Horiguchi goto backout_unlocked; 44376bda666aSChristoph Lameter } 4438998b4382SNaoya Horiguchi } 44391e8f889bSDavid Gibson 444057303d80SAndy Whitcroft /* 444157303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 444257303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 444357303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 444457303d80SAndy Whitcroft * the spinlock. 444557303d80SAndy Whitcroft */ 44465e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 4447285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 44482b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 44492b26736cSAndy Whitcroft goto backout_unlocked; 44502b26736cSAndy Whitcroft } 44515e911373SMike Kravetz /* Just decrements count, does not deallocate */ 4452285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 44535e911373SMike Kravetz } 445457303d80SAndy Whitcroft 44558bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 445683c54070SNick Piggin ret = 0; 44577f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) 44584c887265SAdam Litke goto backout; 44594c887265SAdam Litke 446007443a85SJoonsoo Kim if (anon_rmap) { 446107443a85SJoonsoo Kim ClearPagePrivate(page); 4462285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 4463ac714904SChoi Gi-yong } else 446453f9263bSKirill A. Shutemov page_dup_rmap(page, true); 44651e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 44661e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 4467285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 44681e8f889bSDavid Gibson 44695d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 4470788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 44711e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 4472974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, page, ptl); 44731e8f889bSDavid Gibson } 44741e8f889bSDavid Gibson 4475cb900f41SKirill A. Shutemov spin_unlock(ptl); 4476cb6acd01SMike Kravetz 4477cb6acd01SMike Kravetz /* 4478cb6acd01SMike Kravetz * Only make newly allocated pages active. Existing pages found 4479cb6acd01SMike Kravetz * in the pagecache could be !page_huge_active() if they have been 4480cb6acd01SMike Kravetz * isolated for migration. 4481cb6acd01SMike Kravetz */ 4482cb6acd01SMike Kravetz if (new_page) 4483cb6acd01SMike Kravetz set_page_huge_active(page); 4484cb6acd01SMike Kravetz 44854c887265SAdam Litke unlock_page(page); 44864c887265SAdam Litke out: 4487ac9b9c66SHugh Dickins return ret; 44884c887265SAdam Litke 44894c887265SAdam Litke backout: 4490cb900f41SKirill A. Shutemov spin_unlock(ptl); 44912b26736cSAndy Whitcroft backout_unlocked: 44924c887265SAdam Litke unlock_page(page); 4493285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 44944c887265SAdam Litke put_page(page); 44954c887265SAdam Litke goto out; 4496ac9b9c66SHugh Dickins } 4497ac9b9c66SHugh Dickins 44988382d914SDavidlohr Bueso #ifdef CONFIG_SMP 4499188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 45008382d914SDavidlohr Bueso { 45018382d914SDavidlohr Bueso unsigned long key[2]; 45028382d914SDavidlohr Bueso u32 hash; 45038382d914SDavidlohr Bueso 45048382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 45058382d914SDavidlohr Bueso key[1] = idx; 45068382d914SDavidlohr Bueso 450755254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 45088382d914SDavidlohr Bueso 45098382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 45108382d914SDavidlohr Bueso } 45118382d914SDavidlohr Bueso #else 45128382d914SDavidlohr Bueso /* 45138382d914SDavidlohr Bueso * For uniprocesor systems we always use a single mutex, so just 45148382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 45158382d914SDavidlohr Bueso */ 4516188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 45178382d914SDavidlohr Bueso { 45188382d914SDavidlohr Bueso return 0; 45198382d914SDavidlohr Bueso } 45208382d914SDavidlohr Bueso #endif 45218382d914SDavidlohr Bueso 45222b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 4523788c7df4SHugh Dickins unsigned long address, unsigned int flags) 452486e5216fSAdam Litke { 45258382d914SDavidlohr Bueso pte_t *ptep, entry; 4526cb900f41SKirill A. Shutemov spinlock_t *ptl; 45272b740303SSouptick Joarder vm_fault_t ret; 45288382d914SDavidlohr Bueso u32 hash; 45298382d914SDavidlohr Bueso pgoff_t idx; 45300fe6e20bSNaoya Horiguchi struct page *page = NULL; 453157303d80SAndy Whitcroft struct page *pagecache_page = NULL; 4532a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 45338382d914SDavidlohr Bueso struct address_space *mapping; 45340f792cf9SNaoya Horiguchi int need_wait_lock = 0; 4535285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 453686e5216fSAdam Litke 4537285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4538fd6a03edSNaoya Horiguchi if (ptep) { 4539c0d0381aSMike Kravetz /* 4540c0d0381aSMike Kravetz * Since we hold no locks, ptep could be stale. That is 4541c0d0381aSMike Kravetz * OK as we are only making decisions based on content and 4542c0d0381aSMike Kravetz * not actually modifying content here. 4543c0d0381aSMike Kravetz */ 4544fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 4545290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 4546cb900f41SKirill A. Shutemov migration_entry_wait_huge(vma, mm, ptep); 4547290408d4SNaoya Horiguchi return 0; 4548290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 4549aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 4550972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 4551b43a9990SMike Kravetz } 45528382d914SDavidlohr Bueso 4553c0d0381aSMike Kravetz /* 4554c0d0381aSMike Kravetz * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold 455587bf91d3SMike Kravetz * until finished with ptep. This serves two purposes: 455687bf91d3SMike Kravetz * 1) It prevents huge_pmd_unshare from being called elsewhere 455787bf91d3SMike Kravetz * and making the ptep no longer valid. 455887bf91d3SMike Kravetz * 2) It synchronizes us with i_size modifications during truncation. 4559c0d0381aSMike Kravetz * 4560c0d0381aSMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 4561c0d0381aSMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 4562c0d0381aSMike Kravetz * something has changed. 4563c0d0381aSMike Kravetz */ 4564ddeaab32SMike Kravetz mapping = vma->vm_file->f_mapping; 4565c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 4566c0d0381aSMike Kravetz ptep = huge_pte_alloc(mm, haddr, huge_page_size(h)); 4567c0d0381aSMike Kravetz if (!ptep) { 4568c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 4569c0d0381aSMike Kravetz return VM_FAULT_OOM; 4570c0d0381aSMike Kravetz } 4571ddeaab32SMike Kravetz 45723935baa9SDavid Gibson /* 45733935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 45743935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 45753935baa9SDavid Gibson * the same page in the page cache. 45763935baa9SDavid Gibson */ 4577c0d0381aSMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 4578188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 4579c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 45808382d914SDavidlohr Bueso 45817f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 45827f2e9525SGerald Schaefer if (huge_pte_none(entry)) { 45838382d914SDavidlohr Bueso ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags); 4584b4d1d99fSDavid Gibson goto out_mutex; 45853935baa9SDavid Gibson } 458686e5216fSAdam Litke 458783c54070SNick Piggin ret = 0; 45881e8f889bSDavid Gibson 458957303d80SAndy Whitcroft /* 45900f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 45910f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 45927c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 45937c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 45947c8de358SEthon Paul * properly handle it. 45950f792cf9SNaoya Horiguchi */ 45960f792cf9SNaoya Horiguchi if (!pte_present(entry)) 45970f792cf9SNaoya Horiguchi goto out_mutex; 45980f792cf9SNaoya Horiguchi 45990f792cf9SNaoya Horiguchi /* 460057303d80SAndy Whitcroft * If we are going to COW the mapping later, we examine the pending 460157303d80SAndy Whitcroft * reservations for this page now. This will ensure that any 460257303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 460357303d80SAndy Whitcroft * spinlock. For private mappings, we also lookup the pagecache 460457303d80SAndy Whitcroft * page now as it is used to determine if a reservation has been 460557303d80SAndy Whitcroft * consumed. 460657303d80SAndy Whitcroft */ 4607106c992aSGerald Schaefer if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 4608285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 46092b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 4610b4d1d99fSDavid Gibson goto out_mutex; 46112b26736cSAndy Whitcroft } 46125e911373SMike Kravetz /* Just decrements count, does not deallocate */ 4613285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 461457303d80SAndy Whitcroft 4615f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 461657303d80SAndy Whitcroft pagecache_page = hugetlbfs_pagecache_page(h, 4617285b8dcaSHuang Ying vma, haddr); 461857303d80SAndy Whitcroft } 461957303d80SAndy Whitcroft 46200f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 46210fe6e20bSNaoya Horiguchi 46221e8f889bSDavid Gibson /* Check for a racing update before calling hugetlb_cow */ 4623b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 4624cb900f41SKirill A. Shutemov goto out_ptl; 4625b4d1d99fSDavid Gibson 46260f792cf9SNaoya Horiguchi /* 46270f792cf9SNaoya Horiguchi * hugetlb_cow() requires page locks of pte_page(entry) and 46280f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 46290f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 46300f792cf9SNaoya Horiguchi */ 46310f792cf9SNaoya Horiguchi page = pte_page(entry); 46320f792cf9SNaoya Horiguchi if (page != pagecache_page) 46330f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 46340f792cf9SNaoya Horiguchi need_wait_lock = 1; 46350f792cf9SNaoya Horiguchi goto out_ptl; 46360f792cf9SNaoya Horiguchi } 46370f792cf9SNaoya Horiguchi 46380f792cf9SNaoya Horiguchi get_page(page); 4639b4d1d99fSDavid Gibson 4640788c7df4SHugh Dickins if (flags & FAULT_FLAG_WRITE) { 4641106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 4642974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, 4643cb900f41SKirill A. Shutemov pagecache_page, ptl); 46440f792cf9SNaoya Horiguchi goto out_put_page; 4645b4d1d99fSDavid Gibson } 4646106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 4647b4d1d99fSDavid Gibson } 4648b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 4649285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 4650788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 4651285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 46520f792cf9SNaoya Horiguchi out_put_page: 46530f792cf9SNaoya Horiguchi if (page != pagecache_page) 46540f792cf9SNaoya Horiguchi unlock_page(page); 46550f792cf9SNaoya Horiguchi put_page(page); 4656cb900f41SKirill A. Shutemov out_ptl: 4657cb900f41SKirill A. Shutemov spin_unlock(ptl); 465857303d80SAndy Whitcroft 465957303d80SAndy Whitcroft if (pagecache_page) { 466057303d80SAndy Whitcroft unlock_page(pagecache_page); 466157303d80SAndy Whitcroft put_page(pagecache_page); 466257303d80SAndy Whitcroft } 4663b4d1d99fSDavid Gibson out_mutex: 4664c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 4665c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 46660f792cf9SNaoya Horiguchi /* 46670f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 46680f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 46690f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 46700f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 46710f792cf9SNaoya Horiguchi * here without taking refcount. 46720f792cf9SNaoya Horiguchi */ 46730f792cf9SNaoya Horiguchi if (need_wait_lock) 46740f792cf9SNaoya Horiguchi wait_on_page_locked(page); 46751e8f889bSDavid Gibson return ret; 467686e5216fSAdam Litke } 467786e5216fSAdam Litke 46788fb5debcSMike Kravetz /* 46798fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 46808fb5debcSMike Kravetz * modifications for huge pages. 46818fb5debcSMike Kravetz */ 46828fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 46838fb5debcSMike Kravetz pte_t *dst_pte, 46848fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 46858fb5debcSMike Kravetz unsigned long dst_addr, 46868fb5debcSMike Kravetz unsigned long src_addr, 46878fb5debcSMike Kravetz struct page **pagep) 46888fb5debcSMike Kravetz { 46891e392147SAndrea Arcangeli struct address_space *mapping; 46901e392147SAndrea Arcangeli pgoff_t idx; 46911e392147SAndrea Arcangeli unsigned long size; 46921c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 46938fb5debcSMike Kravetz struct hstate *h = hstate_vma(dst_vma); 46948fb5debcSMike Kravetz pte_t _dst_pte; 46958fb5debcSMike Kravetz spinlock_t *ptl; 46968fb5debcSMike Kravetz int ret; 46978fb5debcSMike Kravetz struct page *page; 46988fb5debcSMike Kravetz 46998fb5debcSMike Kravetz if (!*pagep) { 47008fb5debcSMike Kravetz ret = -ENOMEM; 47018fb5debcSMike Kravetz page = alloc_huge_page(dst_vma, dst_addr, 0); 47028fb5debcSMike Kravetz if (IS_ERR(page)) 47038fb5debcSMike Kravetz goto out; 47048fb5debcSMike Kravetz 47058fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 47068fb5debcSMike Kravetz (const void __user *) src_addr, 4707810a56b9SMike Kravetz pages_per_huge_page(h), false); 47088fb5debcSMike Kravetz 4709c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 47108fb5debcSMike Kravetz if (unlikely(ret)) { 47119e368259SAndrea Arcangeli ret = -ENOENT; 47128fb5debcSMike Kravetz *pagep = page; 47138fb5debcSMike Kravetz /* don't free the page */ 47148fb5debcSMike Kravetz goto out; 47158fb5debcSMike Kravetz } 47168fb5debcSMike Kravetz } else { 47178fb5debcSMike Kravetz page = *pagep; 47188fb5debcSMike Kravetz *pagep = NULL; 47198fb5debcSMike Kravetz } 47208fb5debcSMike Kravetz 47218fb5debcSMike Kravetz /* 47228fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 47238fb5debcSMike Kravetz * preceding stores to the page contents become visible before 47248fb5debcSMike Kravetz * the set_pte_at() write. 47258fb5debcSMike Kravetz */ 47268fb5debcSMike Kravetz __SetPageUptodate(page); 47278fb5debcSMike Kravetz 47281e392147SAndrea Arcangeli mapping = dst_vma->vm_file->f_mapping; 47291e392147SAndrea Arcangeli idx = vma_hugecache_offset(h, dst_vma, dst_addr); 47301e392147SAndrea Arcangeli 47311c9e8defSMike Kravetz /* 47321c9e8defSMike Kravetz * If shared, add to page cache 47331c9e8defSMike Kravetz */ 47341c9e8defSMike Kravetz if (vm_shared) { 47351e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 47361e392147SAndrea Arcangeli ret = -EFAULT; 47371e392147SAndrea Arcangeli if (idx >= size) 47381e392147SAndrea Arcangeli goto out_release_nounlock; 47391c9e8defSMike Kravetz 47401e392147SAndrea Arcangeli /* 47411e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 47421e392147SAndrea Arcangeli * huge_add_to_page_cache() below happens through the 47431e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 47441e392147SAndrea Arcangeli * the caller. 47451e392147SAndrea Arcangeli */ 47461c9e8defSMike Kravetz ret = huge_add_to_page_cache(page, mapping, idx); 47471c9e8defSMike Kravetz if (ret) 47481c9e8defSMike Kravetz goto out_release_nounlock; 47491c9e8defSMike Kravetz } 47501c9e8defSMike Kravetz 47518fb5debcSMike Kravetz ptl = huge_pte_lockptr(h, dst_mm, dst_pte); 47528fb5debcSMike Kravetz spin_lock(ptl); 47538fb5debcSMike Kravetz 47541e392147SAndrea Arcangeli /* 47551e392147SAndrea Arcangeli * Recheck the i_size after holding PT lock to make sure not 47561e392147SAndrea Arcangeli * to leave any page mapped (as page_mapped()) beyond the end 47571e392147SAndrea Arcangeli * of the i_size (remove_inode_hugepages() is strict about 47581e392147SAndrea Arcangeli * enforcing that). If we bail out here, we'll also leave a 47591e392147SAndrea Arcangeli * page in the radix tree in the vm_shared case beyond the end 47601e392147SAndrea Arcangeli * of the i_size, but remove_inode_hugepages() will take care 47611e392147SAndrea Arcangeli * of it as soon as we drop the hugetlb_fault_mutex_table. 47621e392147SAndrea Arcangeli */ 47631e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 47641e392147SAndrea Arcangeli ret = -EFAULT; 47651e392147SAndrea Arcangeli if (idx >= size) 47661e392147SAndrea Arcangeli goto out_release_unlock; 47671e392147SAndrea Arcangeli 47688fb5debcSMike Kravetz ret = -EEXIST; 47698fb5debcSMike Kravetz if (!huge_pte_none(huge_ptep_get(dst_pte))) 47708fb5debcSMike Kravetz goto out_release_unlock; 47718fb5debcSMike Kravetz 47721c9e8defSMike Kravetz if (vm_shared) { 47731c9e8defSMike Kravetz page_dup_rmap(page, true); 47741c9e8defSMike Kravetz } else { 47758fb5debcSMike Kravetz ClearPagePrivate(page); 47768fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 47771c9e8defSMike Kravetz } 47788fb5debcSMike Kravetz 47798fb5debcSMike Kravetz _dst_pte = make_huge_pte(dst_vma, page, dst_vma->vm_flags & VM_WRITE); 47808fb5debcSMike Kravetz if (dst_vma->vm_flags & VM_WRITE) 47818fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 47828fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 47838fb5debcSMike Kravetz 47848fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 47858fb5debcSMike Kravetz 47868fb5debcSMike Kravetz (void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte, 47878fb5debcSMike Kravetz dst_vma->vm_flags & VM_WRITE); 47888fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 47898fb5debcSMike Kravetz 47908fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 47918fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 47928fb5debcSMike Kravetz 47938fb5debcSMike Kravetz spin_unlock(ptl); 4794cb6acd01SMike Kravetz set_page_huge_active(page); 47951c9e8defSMike Kravetz if (vm_shared) 47961c9e8defSMike Kravetz unlock_page(page); 47978fb5debcSMike Kravetz ret = 0; 47988fb5debcSMike Kravetz out: 47998fb5debcSMike Kravetz return ret; 48008fb5debcSMike Kravetz out_release_unlock: 48018fb5debcSMike Kravetz spin_unlock(ptl); 48021c9e8defSMike Kravetz if (vm_shared) 48031c9e8defSMike Kravetz unlock_page(page); 48045af10dfdSAndrea Arcangeli out_release_nounlock: 48058fb5debcSMike Kravetz put_page(page); 48068fb5debcSMike Kravetz goto out; 48078fb5debcSMike Kravetz } 48088fb5debcSMike Kravetz 480928a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 481063551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 481128a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 48124f6da934SPeter Xu long i, unsigned int flags, int *locked) 481363551ae0SDavid Gibson { 4814d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 4815d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 481628a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 4817a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 48182be7cfedSDaniel Jordan int err = -EFAULT; 481963551ae0SDavid Gibson 482063551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 482163551ae0SDavid Gibson pte_t *pte; 4822cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 48232a15efc9SHugh Dickins int absent; 482463551ae0SDavid Gibson struct page *page; 482563551ae0SDavid Gibson 48264c887265SAdam Litke /* 482702057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 482802057967SDavid Rientjes * potentially allocating memory. 482902057967SDavid Rientjes */ 4830fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 483102057967SDavid Rientjes remainder = 0; 483202057967SDavid Rientjes break; 483302057967SDavid Rientjes } 483402057967SDavid Rientjes 483502057967SDavid Rientjes /* 48364c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 48372a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 48384c887265SAdam Litke * first, for the page indexing below to work. 4839cb900f41SKirill A. Shutemov * 4840cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 48414c887265SAdam Litke */ 48427868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 48437868a208SPunit Agrawal huge_page_size(h)); 4844cb900f41SKirill A. Shutemov if (pte) 4845cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 48462a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 484763551ae0SDavid Gibson 48482a15efc9SHugh Dickins /* 48492a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 48503ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 48513ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 48523ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 48533ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 48542a15efc9SHugh Dickins */ 48553ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 48563ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 4857cb900f41SKirill A. Shutemov if (pte) 4858cb900f41SKirill A. Shutemov spin_unlock(ptl); 48592a15efc9SHugh Dickins remainder = 0; 48602a15efc9SHugh Dickins break; 48612a15efc9SHugh Dickins } 48622a15efc9SHugh Dickins 48639cc3a5bdSNaoya Horiguchi /* 48649cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 48659cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 48669cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 48679cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 48689cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 48699cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 48709cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 48719cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 48729cc3a5bdSNaoya Horiguchi */ 48739cc3a5bdSNaoya Horiguchi if (absent || is_swap_pte(huge_ptep_get(pte)) || 4874106c992aSGerald Schaefer ((flags & FOLL_WRITE) && 4875106c992aSGerald Schaefer !huge_pte_write(huge_ptep_get(pte)))) { 48762b740303SSouptick Joarder vm_fault_t ret; 487787ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 48784c887265SAdam Litke 4879cb900f41SKirill A. Shutemov if (pte) 4880cb900f41SKirill A. Shutemov spin_unlock(ptl); 488187ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 488287ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 48834f6da934SPeter Xu if (locked) 488471335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 488571335f37SPeter Xu FAULT_FLAG_KILLABLE; 488687ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 488787ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 488887ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 488987ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 48904426e945SPeter Xu /* 48914426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 48924426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 48934426e945SPeter Xu */ 489487ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 489587ffc118SAndrea Arcangeli } 489687ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 489787ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 48982be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 48991c59827dSHugh Dickins remainder = 0; 49001c59827dSHugh Dickins break; 49011c59827dSHugh Dickins } 490287ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 49034f6da934SPeter Xu if (locked && 49041ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 49054f6da934SPeter Xu *locked = 0; 490687ffc118SAndrea Arcangeli *nr_pages = 0; 490787ffc118SAndrea Arcangeli /* 490887ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 490987ffc118SAndrea Arcangeli * error, it will return zero 491087ffc118SAndrea Arcangeli * instead. 491187ffc118SAndrea Arcangeli * 491287ffc118SAndrea Arcangeli * No need to update "position" as the 491387ffc118SAndrea Arcangeli * caller will not check it after 491487ffc118SAndrea Arcangeli * *nr_pages is set to 0. 491587ffc118SAndrea Arcangeli */ 491687ffc118SAndrea Arcangeli return i; 491787ffc118SAndrea Arcangeli } 491887ffc118SAndrea Arcangeli continue; 491987ffc118SAndrea Arcangeli } 492063551ae0SDavid Gibson 4921a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 49227f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 49238fde12caSLinus Torvalds 49248fde12caSLinus Torvalds /* 4925acbfb087SZhigang Lu * If subpage information not requested, update counters 4926acbfb087SZhigang Lu * and skip the same_page loop below. 4927acbfb087SZhigang Lu */ 4928acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 4929acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 4930acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 4931acbfb087SZhigang Lu vaddr += huge_page_size(h); 4932acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 4933acbfb087SZhigang Lu i += pages_per_huge_page(h); 4934acbfb087SZhigang Lu spin_unlock(ptl); 4935acbfb087SZhigang Lu continue; 4936acbfb087SZhigang Lu } 4937acbfb087SZhigang Lu 4938d5d4b0aaSChen, Kenneth W same_page: 4939d6692183SChen, Kenneth W if (pages) { 494069d177c2SAndy Whitcroft pages[i] = mem_map_offset(page, pfn_offset); 49413faa52c0SJohn Hubbard /* 49423faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: 49433faa52c0SJohn Hubbard * a) we hold the ptl lock, and b) we've just checked 49443faa52c0SJohn Hubbard * that the huge page is present in the page tables. If 49453faa52c0SJohn Hubbard * the huge page is present, then the tail pages must 49463faa52c0SJohn Hubbard * also be present. The ptl prevents the head page and 49473faa52c0SJohn Hubbard * tail pages from being rearranged in any way. So this 49483faa52c0SJohn Hubbard * page must be available at this point, unless the page 49493faa52c0SJohn Hubbard * refcount overflowed: 49503faa52c0SJohn Hubbard */ 49513faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(pages[i], flags))) { 49523faa52c0SJohn Hubbard spin_unlock(ptl); 49533faa52c0SJohn Hubbard remainder = 0; 49543faa52c0SJohn Hubbard err = -ENOMEM; 49553faa52c0SJohn Hubbard break; 49563faa52c0SJohn Hubbard } 4957d6692183SChen, Kenneth W } 495863551ae0SDavid Gibson 495963551ae0SDavid Gibson if (vmas) 496063551ae0SDavid Gibson vmas[i] = vma; 496163551ae0SDavid Gibson 496263551ae0SDavid Gibson vaddr += PAGE_SIZE; 4963d5d4b0aaSChen, Kenneth W ++pfn_offset; 496463551ae0SDavid Gibson --remainder; 496563551ae0SDavid Gibson ++i; 4966d5d4b0aaSChen, Kenneth W if (vaddr < vma->vm_end && remainder && 4967a5516438SAndi Kleen pfn_offset < pages_per_huge_page(h)) { 4968d5d4b0aaSChen, Kenneth W /* 4969d5d4b0aaSChen, Kenneth W * We use pfn_offset to avoid touching the pageframes 4970d5d4b0aaSChen, Kenneth W * of this compound page. 4971d5d4b0aaSChen, Kenneth W */ 4972d5d4b0aaSChen, Kenneth W goto same_page; 4973d5d4b0aaSChen, Kenneth W } 4974cb900f41SKirill A. Shutemov spin_unlock(ptl); 497563551ae0SDavid Gibson } 497628a35716SMichel Lespinasse *nr_pages = remainder; 497787ffc118SAndrea Arcangeli /* 497887ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 497987ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 498087ffc118SAndrea Arcangeli * branch. 498187ffc118SAndrea Arcangeli */ 498263551ae0SDavid Gibson *position = vaddr; 498363551ae0SDavid Gibson 49842be7cfedSDaniel Jordan return i ? i : err; 498563551ae0SDavid Gibson } 49868f860591SZhang, Yanmin 49875491ae7bSAneesh Kumar K.V #ifndef __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE 49885491ae7bSAneesh Kumar K.V /* 49895491ae7bSAneesh Kumar K.V * ARCHes with special requirements for evicting HUGETLB backing TLB entries can 49905491ae7bSAneesh Kumar K.V * implement this. 49915491ae7bSAneesh Kumar K.V */ 49925491ae7bSAneesh Kumar K.V #define flush_hugetlb_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) 49935491ae7bSAneesh Kumar K.V #endif 49945491ae7bSAneesh Kumar K.V 49957da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 49968f860591SZhang, Yanmin unsigned long address, unsigned long end, pgprot_t newprot) 49978f860591SZhang, Yanmin { 49988f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 49998f860591SZhang, Yanmin unsigned long start = address; 50008f860591SZhang, Yanmin pte_t *ptep; 50018f860591SZhang, Yanmin pte_t pte; 5002a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 50037da4d641SPeter Zijlstra unsigned long pages = 0; 5004dff11abeSMike Kravetz bool shared_pmd = false; 5005ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 5006dff11abeSMike Kravetz 5007dff11abeSMike Kravetz /* 5008dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 5009ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 5010dff11abeSMike Kravetz * range if PMD sharing is possible. 5011dff11abeSMike Kravetz */ 50127269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 50137269f999SJérôme Glisse 0, vma, mm, start, end); 5014ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 50158f860591SZhang, Yanmin 50168f860591SZhang, Yanmin BUG_ON(address >= end); 5017ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 50188f860591SZhang, Yanmin 5019ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 502083cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 5021a5516438SAndi Kleen for (; address < end; address += huge_page_size(h)) { 5022cb900f41SKirill A. Shutemov spinlock_t *ptl; 50237868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, huge_page_size(h)); 50248f860591SZhang, Yanmin if (!ptep) 50258f860591SZhang, Yanmin continue; 5026cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 502734ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 50287da4d641SPeter Zijlstra pages++; 5029cb900f41SKirill A. Shutemov spin_unlock(ptl); 5030dff11abeSMike Kravetz shared_pmd = true; 503139dde65cSChen, Kenneth W continue; 50327da4d641SPeter Zijlstra } 5033a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 5034a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 5035a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5036a8bda28dSNaoya Horiguchi continue; 5037a8bda28dSNaoya Horiguchi } 5038a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 5039a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 5040a8bda28dSNaoya Horiguchi 5041a8bda28dSNaoya Horiguchi if (is_write_migration_entry(entry)) { 5042a8bda28dSNaoya Horiguchi pte_t newpte; 5043a8bda28dSNaoya Horiguchi 5044a8bda28dSNaoya Horiguchi make_migration_entry_read(&entry); 5045a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 5046e5251fd4SPunit Agrawal set_huge_swap_pte_at(mm, address, ptep, 5047e5251fd4SPunit Agrawal newpte, huge_page_size(h)); 5048a8bda28dSNaoya Horiguchi pages++; 5049a8bda28dSNaoya Horiguchi } 5050a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5051a8bda28dSNaoya Horiguchi continue; 5052a8bda28dSNaoya Horiguchi } 5053a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 5054023bdd00SAneesh Kumar K.V pte_t old_pte; 5055023bdd00SAneesh Kumar K.V 5056023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 5057023bdd00SAneesh Kumar K.V pte = pte_mkhuge(huge_pte_modify(old_pte, newprot)); 5058be7517d6STony Lu pte = arch_make_huge_pte(pte, vma, NULL, 0); 5059023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 50607da4d641SPeter Zijlstra pages++; 50618f860591SZhang, Yanmin } 5062cb900f41SKirill A. Shutemov spin_unlock(ptl); 50638f860591SZhang, Yanmin } 5064d833352aSMel Gorman /* 5065c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 5066d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 5067c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 5068dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 5069dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 5070d833352aSMel Gorman */ 5071dff11abeSMike Kravetz if (shared_pmd) 5072ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 5073dff11abeSMike Kravetz else 50745491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 50750f10851eSJérôme Glisse /* 50760f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 50770f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 50780f10851eSJérôme Glisse * 5079ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 50800f10851eSJérôme Glisse */ 508183cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 5082ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 50837da4d641SPeter Zijlstra 50847da4d641SPeter Zijlstra return pages << h->order; 50858f860591SZhang, Yanmin } 50868f860591SZhang, Yanmin 5087a1e78772SMel Gorman int hugetlb_reserve_pages(struct inode *inode, 5088a1e78772SMel Gorman long from, long to, 50895a6fe125SMel Gorman struct vm_area_struct *vma, 5090ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 5091e4e574b7SAdam Litke { 50920db9d74eSMina Almasry long ret, chg, add = -1; 5093a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 509490481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 50959119a41eSJoonsoo Kim struct resv_map *resv_map; 5096075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 50970db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 5098e4e574b7SAdam Litke 509963489f8eSMike Kravetz /* This should never happen */ 510063489f8eSMike Kravetz if (from > to) { 510163489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 510263489f8eSMike Kravetz return -EINVAL; 510363489f8eSMike Kravetz } 510463489f8eSMike Kravetz 5105a1e78772SMel Gorman /* 510617c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 510717c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 510890481622SDavid Gibson * without using reserves 510917c9d12eSMel Gorman */ 5110ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 511117c9d12eSMel Gorman return 0; 511217c9d12eSMel Gorman 511317c9d12eSMel Gorman /* 5114a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 5115a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 5116a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 5117a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 5118a1e78772SMel Gorman */ 51199119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 5120f27a5136SMike Kravetz /* 5121f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 5122f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 5123f27a5136SMike Kravetz * hugetlbfs_get_inode). 5124f27a5136SMike Kravetz */ 51254e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 51269119a41eSJoonsoo Kim 51270db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 51289119a41eSJoonsoo Kim 51299119a41eSJoonsoo Kim } else { 5130e9fe92aeSMina Almasry /* Private mapping. */ 51319119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 51325a6fe125SMel Gorman if (!resv_map) 51335a6fe125SMel Gorman return -ENOMEM; 51345a6fe125SMel Gorman 513517c9d12eSMel Gorman chg = to - from; 513617c9d12eSMel Gorman 51375a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 51385a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 51395a6fe125SMel Gorman } 51405a6fe125SMel Gorman 5141c50ac050SDave Hansen if (chg < 0) { 5142c50ac050SDave Hansen ret = chg; 5143c50ac050SDave Hansen goto out_err; 5144c50ac050SDave Hansen } 514517c9d12eSMel Gorman 5146075a61d0SMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 5147075a61d0SMina Almasry hstate_index(h), chg * pages_per_huge_page(h), &h_cg); 5148075a61d0SMina Almasry 5149075a61d0SMina Almasry if (ret < 0) { 5150075a61d0SMina Almasry ret = -ENOMEM; 5151075a61d0SMina Almasry goto out_err; 5152075a61d0SMina Almasry } 5153075a61d0SMina Almasry 5154075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 5155075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 5156075a61d0SMina Almasry * of the resv_map. 5157075a61d0SMina Almasry */ 5158075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 5159075a61d0SMina Almasry } 5160075a61d0SMina Almasry 51611c5ecae3SMike Kravetz /* 51621c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 51631c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 51641c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 51651c5ecae3SMike Kravetz */ 51661c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 51671c5ecae3SMike Kravetz if (gbl_reserve < 0) { 5168c50ac050SDave Hansen ret = -ENOSPC; 5169075a61d0SMina Almasry goto out_uncharge_cgroup; 5170c50ac050SDave Hansen } 517117c9d12eSMel Gorman 517217c9d12eSMel Gorman /* 517317c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 517490481622SDavid Gibson * Hand the pages back to the subpool if there are not 517517c9d12eSMel Gorman */ 51761c5ecae3SMike Kravetz ret = hugetlb_acct_memory(h, gbl_reserve); 517717c9d12eSMel Gorman if (ret < 0) { 5178075a61d0SMina Almasry goto out_put_pages; 517917c9d12eSMel Gorman } 518017c9d12eSMel Gorman 518117c9d12eSMel Gorman /* 518217c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 518317c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 518417c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 518517c9d12eSMel Gorman * the reservation was and the page cache tells how much of 518617c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 518717c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 518817c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 518917c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 519017c9d12eSMel Gorman * else has to be done for private mappings here 519117c9d12eSMel Gorman */ 519233039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 5193075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 519433039678SMike Kravetz 51950db9d74eSMina Almasry if (unlikely(add < 0)) { 51960db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 5197075a61d0SMina Almasry goto out_put_pages; 51980db9d74eSMina Almasry } else if (unlikely(chg > add)) { 519933039678SMike Kravetz /* 520033039678SMike Kravetz * pages in this range were added to the reserve 520133039678SMike Kravetz * map between region_chg and region_add. This 520233039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 520333039678SMike Kravetz * the subpool and reserve counts modified above 520433039678SMike Kravetz * based on the difference. 520533039678SMike Kravetz */ 520633039678SMike Kravetz long rsv_adjust; 520733039678SMike Kravetz 5208075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 5209075a61d0SMina Almasry hstate_index(h), 5210075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 5211075a61d0SMina Almasry 521233039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 521333039678SMike Kravetz chg - add); 521433039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 521533039678SMike Kravetz } 521633039678SMike Kravetz } 5217a43a8c39SChen, Kenneth W return 0; 5218075a61d0SMina Almasry out_put_pages: 5219075a61d0SMina Almasry /* put back original number of pages, chg */ 5220075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 5221075a61d0SMina Almasry out_uncharge_cgroup: 5222075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 5223075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 5224c50ac050SDave Hansen out_err: 52255e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 52260db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 52270db9d74eSMina Almasry * region_add failed or didn't run. 52280db9d74eSMina Almasry */ 52290db9d74eSMina Almasry if (chg >= 0 && add < 0) 52300db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 5231f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 5232f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 5233c50ac050SDave Hansen return ret; 5234a43a8c39SChen, Kenneth W } 5235a43a8c39SChen, Kenneth W 5236b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 5237b5cec28dSMike Kravetz long freed) 5238a43a8c39SChen, Kenneth W { 5239a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 52404e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 52419119a41eSJoonsoo Kim long chg = 0; 524290481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 52431c5ecae3SMike Kravetz long gbl_reserve; 524445c682a6SKen Chen 5245f27a5136SMike Kravetz /* 5246f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 5247f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 5248f27a5136SMike Kravetz */ 5249b5cec28dSMike Kravetz if (resv_map) { 5250b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 5251b5cec28dSMike Kravetz /* 5252b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 5253b5cec28dSMike Kravetz * must be split and another region descriptor can not be 5254b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 5255b5cec28dSMike Kravetz */ 5256b5cec28dSMike Kravetz if (chg < 0) 5257b5cec28dSMike Kravetz return chg; 5258b5cec28dSMike Kravetz } 5259b5cec28dSMike Kravetz 526045c682a6SKen Chen spin_lock(&inode->i_lock); 5261e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 526245c682a6SKen Chen spin_unlock(&inode->i_lock); 526345c682a6SKen Chen 52641c5ecae3SMike Kravetz /* 52651c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 52661c5ecae3SMike Kravetz * reservations to be released may be adjusted. 52671c5ecae3SMike Kravetz */ 52681c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 52691c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 5270b5cec28dSMike Kravetz 5271b5cec28dSMike Kravetz return 0; 5272a43a8c39SChen, Kenneth W } 527393f70f90SNaoya Horiguchi 52743212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 52753212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 52763212b535SSteve Capper struct vm_area_struct *vma, 52773212b535SSteve Capper unsigned long addr, pgoff_t idx) 52783212b535SSteve Capper { 52793212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 52803212b535SSteve Capper svma->vm_start; 52813212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 52823212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 52833212b535SSteve Capper 52843212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 5285de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 5286de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 52873212b535SSteve Capper 52883212b535SSteve Capper /* 52893212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 52903212b535SSteve Capper * page table page. 52913212b535SSteve Capper */ 52923212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 52933212b535SSteve Capper vm_flags != svm_flags || 52943212b535SSteve Capper sbase < svma->vm_start || svma->vm_end < s_end) 52953212b535SSteve Capper return 0; 52963212b535SSteve Capper 52973212b535SSteve Capper return saddr; 52983212b535SSteve Capper } 52993212b535SSteve Capper 530031aafb45SNicholas Krause static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) 53013212b535SSteve Capper { 53023212b535SSteve Capper unsigned long base = addr & PUD_MASK; 53033212b535SSteve Capper unsigned long end = base + PUD_SIZE; 53043212b535SSteve Capper 53053212b535SSteve Capper /* 53063212b535SSteve Capper * check on proper vm_flags and page table alignment 53073212b535SSteve Capper */ 5308017b1660SMike Kravetz if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) 530931aafb45SNicholas Krause return true; 531031aafb45SNicholas Krause return false; 53113212b535SSteve Capper } 53123212b535SSteve Capper 53133212b535SSteve Capper /* 5314017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 5315017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 5316017b1660SMike Kravetz * shared pmd mappings. 5317017b1660SMike Kravetz */ 5318017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 5319017b1660SMike Kravetz unsigned long *start, unsigned long *end) 5320017b1660SMike Kravetz { 532175802ca6SPeter Xu unsigned long a_start, a_end; 5322017b1660SMike Kravetz 5323017b1660SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 5324017b1660SMike Kravetz return; 5325017b1660SMike Kravetz 532675802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 532775802ca6SPeter Xu a_start = ALIGN_DOWN(*start, PUD_SIZE); 532875802ca6SPeter Xu a_end = ALIGN(*end, PUD_SIZE); 5329017b1660SMike Kravetz 5330017b1660SMike Kravetz /* 533175802ca6SPeter Xu * Intersect the range with the vma range, since pmd sharing won't be 533275802ca6SPeter Xu * across vma after all 5333017b1660SMike Kravetz */ 533475802ca6SPeter Xu *start = max(vma->vm_start, a_start); 533575802ca6SPeter Xu *end = min(vma->vm_end, a_end); 5336017b1660SMike Kravetz } 5337017b1660SMike Kravetz 5338017b1660SMike Kravetz /* 53393212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 53403212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 53413212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 5342c0d0381aSMike Kravetz * code much cleaner. 5343c0d0381aSMike Kravetz * 5344c0d0381aSMike Kravetz * This routine must be called with i_mmap_rwsem held in at least read mode. 5345c0d0381aSMike Kravetz * For hugetlbfs, this prevents removal of any page table entries associated 5346c0d0381aSMike Kravetz * with the address space. This is important as we are setting up sharing 5347c0d0381aSMike Kravetz * based on existing page table entries (mappings). 53483212b535SSteve Capper */ 53493212b535SSteve Capper pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) 53503212b535SSteve Capper { 53513212b535SSteve Capper struct vm_area_struct *vma = find_vma(mm, addr); 53523212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 53533212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 53543212b535SSteve Capper vma->vm_pgoff; 53553212b535SSteve Capper struct vm_area_struct *svma; 53563212b535SSteve Capper unsigned long saddr; 53573212b535SSteve Capper pte_t *spte = NULL; 53583212b535SSteve Capper pte_t *pte; 5359cb900f41SKirill A. Shutemov spinlock_t *ptl; 53603212b535SSteve Capper 53613212b535SSteve Capper if (!vma_shareable(vma, addr)) 53623212b535SSteve Capper return (pte_t *)pmd_alloc(mm, pud, addr); 53633212b535SSteve Capper 53643212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 53653212b535SSteve Capper if (svma == vma) 53663212b535SSteve Capper continue; 53673212b535SSteve Capper 53683212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 53693212b535SSteve Capper if (saddr) { 53707868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 53717868a208SPunit Agrawal vma_mmu_pagesize(svma)); 53723212b535SSteve Capper if (spte) { 53733212b535SSteve Capper get_page(virt_to_page(spte)); 53743212b535SSteve Capper break; 53753212b535SSteve Capper } 53763212b535SSteve Capper } 53773212b535SSteve Capper } 53783212b535SSteve Capper 53793212b535SSteve Capper if (!spte) 53803212b535SSteve Capper goto out; 53813212b535SSteve Capper 53828bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 5383dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 53843212b535SSteve Capper pud_populate(mm, pud, 53853212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 5386c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 5387dc6c9a35SKirill A. Shutemov } else { 53883212b535SSteve Capper put_page(virt_to_page(spte)); 5389dc6c9a35SKirill A. Shutemov } 5390cb900f41SKirill A. Shutemov spin_unlock(ptl); 53913212b535SSteve Capper out: 53923212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 53933212b535SSteve Capper return pte; 53943212b535SSteve Capper } 53953212b535SSteve Capper 53963212b535SSteve Capper /* 53973212b535SSteve Capper * unmap huge page backed by shared pte. 53983212b535SSteve Capper * 53993212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 54003212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 54013212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 54023212b535SSteve Capper * 5403c0d0381aSMike Kravetz * Called with page table lock held and i_mmap_rwsem held in write mode. 54043212b535SSteve Capper * 54053212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 54063212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 54073212b535SSteve Capper */ 540834ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 540934ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 54103212b535SSteve Capper { 54113212b535SSteve Capper pgd_t *pgd = pgd_offset(mm, *addr); 5412c2febafcSKirill A. Shutemov p4d_t *p4d = p4d_offset(pgd, *addr); 5413c2febafcSKirill A. Shutemov pud_t *pud = pud_offset(p4d, *addr); 54143212b535SSteve Capper 541534ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 54163212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 54173212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 54183212b535SSteve Capper return 0; 54193212b535SSteve Capper 54203212b535SSteve Capper pud_clear(pud); 54213212b535SSteve Capper put_page(virt_to_page(ptep)); 5422dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 54233212b535SSteve Capper *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; 54243212b535SSteve Capper return 1; 54253212b535SSteve Capper } 54269e5fc74cSSteve Capper #define want_pmd_share() (1) 54279e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 54289e5fc74cSSteve Capper pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) 54299e5fc74cSSteve Capper { 54309e5fc74cSSteve Capper return NULL; 54319e5fc74cSSteve Capper } 5432e81f2d22SZhang Zhen 543334ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 543434ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 5435e81f2d22SZhang Zhen { 5436e81f2d22SZhang Zhen return 0; 5437e81f2d22SZhang Zhen } 5438017b1660SMike Kravetz 5439017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 5440017b1660SMike Kravetz unsigned long *start, unsigned long *end) 5441017b1660SMike Kravetz { 5442017b1660SMike Kravetz } 54439e5fc74cSSteve Capper #define want_pmd_share() (0) 54443212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 54453212b535SSteve Capper 54469e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 54479e5fc74cSSteve Capper pte_t *huge_pte_alloc(struct mm_struct *mm, 54489e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 54499e5fc74cSSteve Capper { 54509e5fc74cSSteve Capper pgd_t *pgd; 5451c2febafcSKirill A. Shutemov p4d_t *p4d; 54529e5fc74cSSteve Capper pud_t *pud; 54539e5fc74cSSteve Capper pte_t *pte = NULL; 54549e5fc74cSSteve Capper 54559e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 5456f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 5457f4f0a3d8SKirill A. Shutemov if (!p4d) 5458f4f0a3d8SKirill A. Shutemov return NULL; 5459c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 54609e5fc74cSSteve Capper if (pud) { 54619e5fc74cSSteve Capper if (sz == PUD_SIZE) { 54629e5fc74cSSteve Capper pte = (pte_t *)pud; 54639e5fc74cSSteve Capper } else { 54649e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 54659e5fc74cSSteve Capper if (want_pmd_share() && pud_none(*pud)) 54669e5fc74cSSteve Capper pte = huge_pmd_share(mm, addr, pud); 54679e5fc74cSSteve Capper else 54689e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 54699e5fc74cSSteve Capper } 54709e5fc74cSSteve Capper } 54714e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 54729e5fc74cSSteve Capper 54739e5fc74cSSteve Capper return pte; 54749e5fc74cSSteve Capper } 54759e5fc74cSSteve Capper 54769b19df29SPunit Agrawal /* 54779b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 54789b19df29SPunit Agrawal * entry at address @addr 54799b19df29SPunit Agrawal * 54808ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 54818ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 54829b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 54839b19df29SPunit Agrawal * table. 54849b19df29SPunit Agrawal */ 54857868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 54867868a208SPunit Agrawal unsigned long addr, unsigned long sz) 54879e5fc74cSSteve Capper { 54889e5fc74cSSteve Capper pgd_t *pgd; 5489c2febafcSKirill A. Shutemov p4d_t *p4d; 54908ac0b81aSLi Xinhai pud_t *pud; 54918ac0b81aSLi Xinhai pmd_t *pmd; 54929e5fc74cSSteve Capper 54939e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 5494c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 5495c2febafcSKirill A. Shutemov return NULL; 5496c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 5497c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 5498c2febafcSKirill A. Shutemov return NULL; 54999b19df29SPunit Agrawal 5500c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 55018ac0b81aSLi Xinhai if (sz == PUD_SIZE) 55028ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 55039e5fc74cSSteve Capper return (pte_t *)pud; 55048ac0b81aSLi Xinhai if (!pud_present(*pud)) 55058ac0b81aSLi Xinhai return NULL; 55068ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 55079b19df29SPunit Agrawal 55089e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 55098ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 55109e5fc74cSSteve Capper return (pte_t *)pmd; 55119e5fc74cSSteve Capper } 55129e5fc74cSSteve Capper 551361f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 551461f77edaSNaoya Horiguchi 551561f77edaSNaoya Horiguchi /* 551661f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 551761f77edaSNaoya Horiguchi * behavior. 551861f77edaSNaoya Horiguchi */ 551961f77edaSNaoya Horiguchi struct page * __weak 552061f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 552161f77edaSNaoya Horiguchi int write) 552261f77edaSNaoya Horiguchi { 552361f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 552461f77edaSNaoya Horiguchi } 552561f77edaSNaoya Horiguchi 552661f77edaSNaoya Horiguchi struct page * __weak 55274dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 55284dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 55294dc71451SAneesh Kumar K.V { 55304dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 55314dc71451SAneesh Kumar K.V return NULL; 55324dc71451SAneesh Kumar K.V } 55334dc71451SAneesh Kumar K.V 55344dc71451SAneesh Kumar K.V struct page * __weak 55359e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 5536e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 55379e5fc74cSSteve Capper { 5538e66f17ffSNaoya Horiguchi struct page *page = NULL; 5539e66f17ffSNaoya Horiguchi spinlock_t *ptl; 5540c9d398faSNaoya Horiguchi pte_t pte; 55413faa52c0SJohn Hubbard 55423faa52c0SJohn Hubbard /* FOLL_GET and FOLL_PIN are mutually exclusive. */ 55433faa52c0SJohn Hubbard if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == 55443faa52c0SJohn Hubbard (FOLL_PIN | FOLL_GET))) 55453faa52c0SJohn Hubbard return NULL; 55463faa52c0SJohn Hubbard 5547e66f17ffSNaoya Horiguchi retry: 5548e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 5549e66f17ffSNaoya Horiguchi spin_lock(ptl); 5550e66f17ffSNaoya Horiguchi /* 5551e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 5552e66f17ffSNaoya Horiguchi * unmapped from other threads. 5553e66f17ffSNaoya Horiguchi */ 5554e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 5555e66f17ffSNaoya Horiguchi goto out; 5556c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 5557c9d398faSNaoya Horiguchi if (pte_present(pte)) { 555897534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 55593faa52c0SJohn Hubbard /* 55603faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 55613faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 55623faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 55633faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 55643faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 55653faa52c0SJohn Hubbard * unless the page refcount overflowed: 55663faa52c0SJohn Hubbard */ 55673faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 55683faa52c0SJohn Hubbard page = NULL; 55693faa52c0SJohn Hubbard goto out; 55703faa52c0SJohn Hubbard } 5571e66f17ffSNaoya Horiguchi } else { 5572c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 5573e66f17ffSNaoya Horiguchi spin_unlock(ptl); 5574e66f17ffSNaoya Horiguchi __migration_entry_wait(mm, (pte_t *)pmd, ptl); 5575e66f17ffSNaoya Horiguchi goto retry; 5576e66f17ffSNaoya Horiguchi } 5577e66f17ffSNaoya Horiguchi /* 5578e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 5579e66f17ffSNaoya Horiguchi * follow_page_mask(). 5580e66f17ffSNaoya Horiguchi */ 5581e66f17ffSNaoya Horiguchi } 5582e66f17ffSNaoya Horiguchi out: 5583e66f17ffSNaoya Horiguchi spin_unlock(ptl); 55849e5fc74cSSteve Capper return page; 55859e5fc74cSSteve Capper } 55869e5fc74cSSteve Capper 558761f77edaSNaoya Horiguchi struct page * __weak 55889e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 5589e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 55909e5fc74cSSteve Capper { 55913faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 5592e66f17ffSNaoya Horiguchi return NULL; 55939e5fc74cSSteve Capper 5594e66f17ffSNaoya Horiguchi return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 55959e5fc74cSSteve Capper } 55969e5fc74cSSteve Capper 5597faaa5b62SAnshuman Khandual struct page * __weak 5598faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 5599faaa5b62SAnshuman Khandual { 56003faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 5601faaa5b62SAnshuman Khandual return NULL; 5602faaa5b62SAnshuman Khandual 5603faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 5604faaa5b62SAnshuman Khandual } 5605faaa5b62SAnshuman Khandual 560631caf665SNaoya Horiguchi bool isolate_huge_page(struct page *page, struct list_head *list) 560731caf665SNaoya Horiguchi { 5608bcc54222SNaoya Horiguchi bool ret = true; 5609bcc54222SNaoya Horiguchi 5610309381feSSasha Levin VM_BUG_ON_PAGE(!PageHead(page), page); 561131caf665SNaoya Horiguchi spin_lock(&hugetlb_lock); 5612bcc54222SNaoya Horiguchi if (!page_huge_active(page) || !get_page_unless_zero(page)) { 5613bcc54222SNaoya Horiguchi ret = false; 5614bcc54222SNaoya Horiguchi goto unlock; 5615bcc54222SNaoya Horiguchi } 5616bcc54222SNaoya Horiguchi clear_page_huge_active(page); 561731caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 5618bcc54222SNaoya Horiguchi unlock: 561931caf665SNaoya Horiguchi spin_unlock(&hugetlb_lock); 5620bcc54222SNaoya Horiguchi return ret; 562131caf665SNaoya Horiguchi } 562231caf665SNaoya Horiguchi 562331caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 562431caf665SNaoya Horiguchi { 5625309381feSSasha Levin VM_BUG_ON_PAGE(!PageHead(page), page); 562631caf665SNaoya Horiguchi spin_lock(&hugetlb_lock); 5627bcc54222SNaoya Horiguchi set_page_huge_active(page); 562831caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 562931caf665SNaoya Horiguchi spin_unlock(&hugetlb_lock); 563031caf665SNaoya Horiguchi put_page(page); 563131caf665SNaoya Horiguchi } 5632ab5ac90aSMichal Hocko 5633ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 5634ab5ac90aSMichal Hocko { 5635ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 5636ab5ac90aSMichal Hocko 5637ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 5638ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 5639ab5ac90aSMichal Hocko 5640ab5ac90aSMichal Hocko /* 5641ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 5642ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 5643ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 5644ab5ac90aSMichal Hocko * the temporary status. 5645ab5ac90aSMichal Hocko * 5646ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 5647ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 5648ab5ac90aSMichal Hocko * the per-node's. 5649ab5ac90aSMichal Hocko */ 5650ab5ac90aSMichal Hocko if (PageHugeTemporary(newpage)) { 5651ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 5652ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 5653ab5ac90aSMichal Hocko 5654ab5ac90aSMichal Hocko SetPageHugeTemporary(oldpage); 5655ab5ac90aSMichal Hocko ClearPageHugeTemporary(newpage); 5656ab5ac90aSMichal Hocko 5657ab5ac90aSMichal Hocko spin_lock(&hugetlb_lock); 5658ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 5659ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 5660ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 5661ab5ac90aSMichal Hocko } 5662ab5ac90aSMichal Hocko spin_unlock(&hugetlb_lock); 5663ab5ac90aSMichal Hocko } 5664ab5ac90aSMichal Hocko } 5665cf11e85fSRoman Gushchin 5666cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 5667cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 5668cf11e85fSRoman Gushchin 5669cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 5670cf11e85fSRoman Gushchin { 5671cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 5672cf11e85fSRoman Gushchin return 0; 5673cf11e85fSRoman Gushchin } 5674cf11e85fSRoman Gushchin 5675cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 5676cf11e85fSRoman Gushchin 5677cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 5678cf11e85fSRoman Gushchin { 5679cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 5680cf11e85fSRoman Gushchin int nid; 5681cf11e85fSRoman Gushchin 5682cf11e85fSRoman Gushchin cma_reserve_called = true; 5683cf11e85fSRoman Gushchin 5684cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 5685cf11e85fSRoman Gushchin return; 5686cf11e85fSRoman Gushchin 5687cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 5688cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 5689cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 5690cf11e85fSRoman Gushchin return; 5691cf11e85fSRoman Gushchin } 5692cf11e85fSRoman Gushchin 5693cf11e85fSRoman Gushchin /* 5694cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 5695cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 5696cf11e85fSRoman Gushchin */ 5697cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 5698cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 5699cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 5700cf11e85fSRoman Gushchin 5701cf11e85fSRoman Gushchin reserved = 0; 5702cf11e85fSRoman Gushchin for_each_node_state(nid, N_ONLINE) { 5703cf11e85fSRoman Gushchin int res; 570429d0f41dSBarry Song char name[20]; 5705cf11e85fSRoman Gushchin 5706cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 5707cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 5708cf11e85fSRoman Gushchin 570929d0f41dSBarry Song snprintf(name, 20, "hugetlb%d", nid); 5710cf11e85fSRoman Gushchin res = cma_declare_contiguous_nid(0, size, 0, PAGE_SIZE << order, 571129d0f41dSBarry Song 0, false, name, 5712cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 5713cf11e85fSRoman Gushchin if (res) { 5714cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 5715cf11e85fSRoman Gushchin res, nid); 5716cf11e85fSRoman Gushchin continue; 5717cf11e85fSRoman Gushchin } 5718cf11e85fSRoman Gushchin 5719cf11e85fSRoman Gushchin reserved += size; 5720cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 5721cf11e85fSRoman Gushchin size / SZ_1M, nid); 5722cf11e85fSRoman Gushchin 5723cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 5724cf11e85fSRoman Gushchin break; 5725cf11e85fSRoman Gushchin } 5726cf11e85fSRoman Gushchin } 5727cf11e85fSRoman Gushchin 5728cf11e85fSRoman Gushchin void __init hugetlb_cma_check(void) 5729cf11e85fSRoman Gushchin { 5730cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 5731cf11e85fSRoman Gushchin return; 5732cf11e85fSRoman Gushchin 5733cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 5734cf11e85fSRoman Gushchin } 5735cf11e85fSRoman Gushchin 5736cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 5737