1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * Generic hugetlb support. 46d49e352SNadia Yvette Chambers * (C) Nadia Yvette Chambers, April 2004 51da177e4SLinus Torvalds */ 61da177e4SLinus Torvalds #include <linux/list.h> 71da177e4SLinus Torvalds #include <linux/init.h> 81da177e4SLinus Torvalds #include <linux/mm.h> 9e1759c21SAlexey Dobriyan #include <linux/seq_file.h> 101da177e4SLinus Torvalds #include <linux/sysctl.h> 111da177e4SLinus Torvalds #include <linux/highmem.h> 12cddb8a5cSAndrea Arcangeli #include <linux/mmu_notifier.h> 131da177e4SLinus Torvalds #include <linux/nodemask.h> 1463551ae0SDavid Gibson #include <linux/pagemap.h> 155da7ca86SChristoph Lameter #include <linux/mempolicy.h> 163b32123dSGideon Israel Dsouza #include <linux/compiler.h> 17aea47ff3SChristoph Lameter #include <linux/cpuset.h> 183935baa9SDavid Gibson #include <linux/mutex.h> 1997ad1087SMike Rapoport #include <linux/memblock.h> 20a3437870SNishanth Aravamudan #include <linux/sysfs.h> 215a0e3ad6STejun Heo #include <linux/slab.h> 22bbe88753SJoonsoo Kim #include <linux/sched/mm.h> 2363489f8eSMike Kravetz #include <linux/mmdebug.h> 24174cd4b1SIngo Molnar #include <linux/sched/signal.h> 250fe6e20bSNaoya Horiguchi #include <linux/rmap.h> 26c6247f72SMatthew Wilcox #include <linux/string_helpers.h> 27fd6a03edSNaoya Horiguchi #include <linux/swap.h> 28fd6a03edSNaoya Horiguchi #include <linux/swapops.h> 298382d914SDavidlohr Bueso #include <linux/jhash.h> 3098fa15f3SAnshuman Khandual #include <linux/numa.h> 31c77c0a8aSWaiman Long #include <linux/llist.h> 32cf11e85fSRoman Gushchin #include <linux/cma.h> 338cc5fcbbSMina Almasry #include <linux/migrate.h> 34f9317f77SMike Kravetz #include <linux/nospec.h> 35662ce1dcSYang Yang #include <linux/delayacct.h> 36d6606683SLinus Torvalds 3763551ae0SDavid Gibson #include <asm/page.h> 38ca15ca40SMike Rapoport #include <asm/pgalloc.h> 3924669e58SAneesh Kumar K.V #include <asm/tlb.h> 4063551ae0SDavid Gibson 4124669e58SAneesh Kumar K.V #include <linux/io.h> 4263551ae0SDavid Gibson #include <linux/hugetlb.h> 439dd540e2SAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 449a305230SLee Schermerhorn #include <linux/node.h> 45ab5ac90aSMichal Hocko #include <linux/page_owner.h> 467835e98bSNick Piggin #include "internal.h" 47f41f2ed4SMuchun Song #include "hugetlb_vmemmap.h" 481da177e4SLinus Torvalds 49c3f38a38SAneesh Kumar K.V int hugetlb_max_hstate __read_mostly; 50e5ff2159SAndi Kleen unsigned int default_hstate_idx; 51e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 52cf11e85fSRoman Gushchin 53dbda8feaSBarry Song #ifdef CONFIG_CMA 54cf11e85fSRoman Gushchin static struct cma *hugetlb_cma[MAX_NUMNODES]; 5538e719abSBaolin Wang static unsigned long hugetlb_cma_size_in_node[MAX_NUMNODES] __initdata; 56a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 57a01f4390SMike Kravetz { 58a01f4390SMike Kravetz return cma_pages_valid(hugetlb_cma[page_to_nid(page)], page, 59a01f4390SMike Kravetz 1 << order); 60a01f4390SMike Kravetz } 61a01f4390SMike Kravetz #else 62a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 63a01f4390SMike Kravetz { 64a01f4390SMike Kravetz return false; 65a01f4390SMike Kravetz } 66dbda8feaSBarry Song #endif 67dbda8feaSBarry Song static unsigned long hugetlb_cma_size __initdata; 68cf11e85fSRoman Gushchin 6953ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 7053ba51d2SJon Tollefson 71e5ff2159SAndi Kleen /* for command line parsing */ 72e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 73e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 749fee021dSVaishali Thakkar static bool __initdata parsed_valid_hugepagesz = true; 75282f4214SMike Kravetz static bool __initdata parsed_default_hugepagesz; 76b5389086SZhenguo Yao static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata; 77e5ff2159SAndi Kleen 783935baa9SDavid Gibson /* 7931caf665SNaoya Horiguchi * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, 8031caf665SNaoya Horiguchi * free_huge_pages, and surplus_huge_pages. 813935baa9SDavid Gibson */ 82c3f38a38SAneesh Kumar K.V DEFINE_SPINLOCK(hugetlb_lock); 830bd0f9fbSEric Paris 848382d914SDavidlohr Bueso /* 858382d914SDavidlohr Bueso * Serializes faults on the same logical page. This is used to 868382d914SDavidlohr Bueso * prevent spurious OOMs when the hugepage pool is fully utilized. 878382d914SDavidlohr Bueso */ 888382d914SDavidlohr Bueso static int num_fault_mutexes; 89c672c7f2SMike Kravetz struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; 908382d914SDavidlohr Bueso 917ca02d0aSMike Kravetz /* Forward declaration */ 927ca02d0aSMike Kravetz static int hugetlb_acct_memory(struct hstate *h, long delta); 937ca02d0aSMike Kravetz 941d88433bSMiaohe Lin static inline bool subpool_is_free(struct hugepage_subpool *spool) 951d88433bSMiaohe Lin { 961d88433bSMiaohe Lin if (spool->count) 971d88433bSMiaohe Lin return false; 981d88433bSMiaohe Lin if (spool->max_hpages != -1) 991d88433bSMiaohe Lin return spool->used_hpages == 0; 1001d88433bSMiaohe Lin if (spool->min_hpages != -1) 1011d88433bSMiaohe Lin return spool->rsv_hpages == spool->min_hpages; 1021d88433bSMiaohe Lin 1031d88433bSMiaohe Lin return true; 1041d88433bSMiaohe Lin } 1051d88433bSMiaohe Lin 106db71ef79SMike Kravetz static inline void unlock_or_release_subpool(struct hugepage_subpool *spool, 107db71ef79SMike Kravetz unsigned long irq_flags) 10890481622SDavid Gibson { 109db71ef79SMike Kravetz spin_unlock_irqrestore(&spool->lock, irq_flags); 11090481622SDavid Gibson 11190481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 1127c8de358SEthon Paul * remain, give up any reservations based on minimum size and 1137ca02d0aSMike Kravetz * free the subpool */ 1141d88433bSMiaohe Lin if (subpool_is_free(spool)) { 1157ca02d0aSMike Kravetz if (spool->min_hpages != -1) 1167ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 1177ca02d0aSMike Kravetz -spool->min_hpages); 11890481622SDavid Gibson kfree(spool); 11990481622SDavid Gibson } 1207ca02d0aSMike Kravetz } 12190481622SDavid Gibson 1227ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1237ca02d0aSMike Kravetz long min_hpages) 12490481622SDavid Gibson { 12590481622SDavid Gibson struct hugepage_subpool *spool; 12690481622SDavid Gibson 127c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 12890481622SDavid Gibson if (!spool) 12990481622SDavid Gibson return NULL; 13090481622SDavid Gibson 13190481622SDavid Gibson spin_lock_init(&spool->lock); 13290481622SDavid Gibson spool->count = 1; 1337ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1347ca02d0aSMike Kravetz spool->hstate = h; 1357ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1367ca02d0aSMike Kravetz 1377ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1387ca02d0aSMike Kravetz kfree(spool); 1397ca02d0aSMike Kravetz return NULL; 1407ca02d0aSMike Kravetz } 1417ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 14290481622SDavid Gibson 14390481622SDavid Gibson return spool; 14490481622SDavid Gibson } 14590481622SDavid Gibson 14690481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 14790481622SDavid Gibson { 148db71ef79SMike Kravetz unsigned long flags; 149db71ef79SMike Kravetz 150db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 15190481622SDavid Gibson BUG_ON(!spool->count); 15290481622SDavid Gibson spool->count--; 153db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 15490481622SDavid Gibson } 15590481622SDavid Gibson 1561c5ecae3SMike Kravetz /* 1571c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1581c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1599e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1601c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1611c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1627c8de358SEthon Paul * a subpool minimum size must be maintained. 1631c5ecae3SMike Kravetz */ 1641c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 16590481622SDavid Gibson long delta) 16690481622SDavid Gibson { 1671c5ecae3SMike Kravetz long ret = delta; 16890481622SDavid Gibson 16990481622SDavid Gibson if (!spool) 1701c5ecae3SMike Kravetz return ret; 17190481622SDavid Gibson 172db71ef79SMike Kravetz spin_lock_irq(&spool->lock); 17390481622SDavid Gibson 1741c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1751c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1761c5ecae3SMike Kravetz spool->used_hpages += delta; 1771c5ecae3SMike Kravetz else { 1781c5ecae3SMike Kravetz ret = -ENOMEM; 1791c5ecae3SMike Kravetz goto unlock_ret; 1801c5ecae3SMike Kravetz } 1811c5ecae3SMike Kravetz } 1821c5ecae3SMike Kravetz 18309a95e29SMike Kravetz /* minimum size accounting */ 18409a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1851c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1861c5ecae3SMike Kravetz /* 1871c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1881c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1891c5ecae3SMike Kravetz */ 1901c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1911c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1921c5ecae3SMike Kravetz } else { 1931c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1941c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 1951c5ecae3SMike Kravetz } 1961c5ecae3SMike Kravetz } 1971c5ecae3SMike Kravetz 1981c5ecae3SMike Kravetz unlock_ret: 199db71ef79SMike Kravetz spin_unlock_irq(&spool->lock); 20090481622SDavid Gibson return ret; 20190481622SDavid Gibson } 20290481622SDavid Gibson 2031c5ecae3SMike Kravetz /* 2041c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 2051c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 2061c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 2071c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 2081c5ecae3SMike Kravetz */ 2091c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 21090481622SDavid Gibson long delta) 21190481622SDavid Gibson { 2121c5ecae3SMike Kravetz long ret = delta; 213db71ef79SMike Kravetz unsigned long flags; 2141c5ecae3SMike Kravetz 21590481622SDavid Gibson if (!spool) 2161c5ecae3SMike Kravetz return delta; 21790481622SDavid Gibson 218db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 2191c5ecae3SMike Kravetz 2201c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 22190481622SDavid Gibson spool->used_hpages -= delta; 2221c5ecae3SMike Kravetz 22309a95e29SMike Kravetz /* minimum size accounting */ 22409a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2251c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2261c5ecae3SMike Kravetz ret = 0; 2271c5ecae3SMike Kravetz else 2281c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2291c5ecae3SMike Kravetz 2301c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2311c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2321c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2331c5ecae3SMike Kravetz } 2341c5ecae3SMike Kravetz 2351c5ecae3SMike Kravetz /* 2361c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2371c5ecae3SMike Kravetz * quota reference, free it now. 2381c5ecae3SMike Kravetz */ 239db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 2401c5ecae3SMike Kravetz 2411c5ecae3SMike Kravetz return ret; 24290481622SDavid Gibson } 24390481622SDavid Gibson 24490481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 24590481622SDavid Gibson { 24690481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 24790481622SDavid Gibson } 24890481622SDavid Gibson 24990481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 25090481622SDavid Gibson { 251496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 25290481622SDavid Gibson } 25390481622SDavid Gibson 2540db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2550db9d74eSMina Almasry * it for use. 2560db9d74eSMina Almasry */ 2570db9d74eSMina Almasry static struct file_region * 2580db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2590db9d74eSMina Almasry { 2600db9d74eSMina Almasry struct file_region *nrg = NULL; 2610db9d74eSMina Almasry 2620db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2630db9d74eSMina Almasry 2640db9d74eSMina Almasry resv->region_cache_count--; 2650db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2660db9d74eSMina Almasry list_del(&nrg->link); 2670db9d74eSMina Almasry 2680db9d74eSMina Almasry nrg->from = from; 2690db9d74eSMina Almasry nrg->to = to; 2700db9d74eSMina Almasry 2710db9d74eSMina Almasry return nrg; 2720db9d74eSMina Almasry } 2730db9d74eSMina Almasry 274075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 275075a61d0SMina Almasry struct file_region *rg) 276075a61d0SMina Almasry { 277075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 278075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 279075a61d0SMina Almasry nrg->css = rg->css; 280075a61d0SMina Almasry if (rg->css) 281075a61d0SMina Almasry css_get(rg->css); 282075a61d0SMina Almasry #endif 283075a61d0SMina Almasry } 284075a61d0SMina Almasry 285075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 286075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 287075a61d0SMina Almasry struct hstate *h, 288075a61d0SMina Almasry struct resv_map *resv, 289075a61d0SMina Almasry struct file_region *nrg) 290075a61d0SMina Almasry { 291075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 292075a61d0SMina Almasry if (h_cg) { 293075a61d0SMina Almasry nrg->reservation_counter = 294075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 295075a61d0SMina Almasry nrg->css = &h_cg->css; 296d85aecf2SMiaohe Lin /* 297d85aecf2SMiaohe Lin * The caller will hold exactly one h_cg->css reference for the 298d85aecf2SMiaohe Lin * whole contiguous reservation region. But this area might be 299d85aecf2SMiaohe Lin * scattered when there are already some file_regions reside in 300d85aecf2SMiaohe Lin * it. As a result, many file_regions may share only one css 301d85aecf2SMiaohe Lin * reference. In order to ensure that one file_region must hold 302d85aecf2SMiaohe Lin * exactly one h_cg->css reference, we should do css_get for 303d85aecf2SMiaohe Lin * each file_region and leave the reference held by caller 304d85aecf2SMiaohe Lin * untouched. 305d85aecf2SMiaohe Lin */ 306d85aecf2SMiaohe Lin css_get(&h_cg->css); 307075a61d0SMina Almasry if (!resv->pages_per_hpage) 308075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 309075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 310075a61d0SMina Almasry * a resv_map. 311075a61d0SMina Almasry */ 312075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 313075a61d0SMina Almasry } else { 314075a61d0SMina Almasry nrg->reservation_counter = NULL; 315075a61d0SMina Almasry nrg->css = NULL; 316075a61d0SMina Almasry } 317075a61d0SMina Almasry #endif 318075a61d0SMina Almasry } 319075a61d0SMina Almasry 320d85aecf2SMiaohe Lin static void put_uncharge_info(struct file_region *rg) 321d85aecf2SMiaohe Lin { 322d85aecf2SMiaohe Lin #ifdef CONFIG_CGROUP_HUGETLB 323d85aecf2SMiaohe Lin if (rg->css) 324d85aecf2SMiaohe Lin css_put(rg->css); 325d85aecf2SMiaohe Lin #endif 326d85aecf2SMiaohe Lin } 327d85aecf2SMiaohe Lin 328a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 329a9b3f867SMina Almasry struct file_region *org) 330a9b3f867SMina Almasry { 331a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 3320739eb43SBaolin Wang return rg->reservation_counter == org->reservation_counter && 333a9b3f867SMina Almasry rg->css == org->css; 334a9b3f867SMina Almasry 335a9b3f867SMina Almasry #else 336a9b3f867SMina Almasry return true; 337a9b3f867SMina Almasry #endif 338a9b3f867SMina Almasry } 339a9b3f867SMina Almasry 340a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 341a9b3f867SMina Almasry { 342a9b3f867SMina Almasry struct file_region *nrg = NULL, *prg = NULL; 343a9b3f867SMina Almasry 344a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 345a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 346a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 347a9b3f867SMina Almasry prg->to = rg->to; 348a9b3f867SMina Almasry 349a9b3f867SMina Almasry list_del(&rg->link); 350d85aecf2SMiaohe Lin put_uncharge_info(rg); 351a9b3f867SMina Almasry kfree(rg); 352a9b3f867SMina Almasry 3537db5e7b6SWei Yang rg = prg; 354a9b3f867SMina Almasry } 355a9b3f867SMina Almasry 356a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 357a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 358a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 359a9b3f867SMina Almasry nrg->from = rg->from; 360a9b3f867SMina Almasry 361a9b3f867SMina Almasry list_del(&rg->link); 362d85aecf2SMiaohe Lin put_uncharge_info(rg); 363a9b3f867SMina Almasry kfree(rg); 364a9b3f867SMina Almasry } 365a9b3f867SMina Almasry } 366a9b3f867SMina Almasry 3672103cf9cSPeter Xu static inline long 36884448c8eSJakob Koschel hugetlb_resv_map_add(struct resv_map *map, struct list_head *rg, long from, 3692103cf9cSPeter Xu long to, struct hstate *h, struct hugetlb_cgroup *cg, 3702103cf9cSPeter Xu long *regions_needed) 3712103cf9cSPeter Xu { 3722103cf9cSPeter Xu struct file_region *nrg; 3732103cf9cSPeter Xu 3742103cf9cSPeter Xu if (!regions_needed) { 3752103cf9cSPeter Xu nrg = get_file_region_entry_from_cache(map, from, to); 3762103cf9cSPeter Xu record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); 37784448c8eSJakob Koschel list_add(&nrg->link, rg); 3782103cf9cSPeter Xu coalesce_file_region(map, nrg); 3792103cf9cSPeter Xu } else 3802103cf9cSPeter Xu *regions_needed += 1; 3812103cf9cSPeter Xu 3822103cf9cSPeter Xu return to - from; 3832103cf9cSPeter Xu } 3842103cf9cSPeter Xu 385972a3da3SWei Yang /* 386972a3da3SWei Yang * Must be called with resv->lock held. 387972a3da3SWei Yang * 388972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 389972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 390972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 391972a3da3SWei Yang * the regions for this range. 392d75c6af9SMina Almasry */ 393d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 394075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 395972a3da3SWei Yang struct hstate *h, long *regions_needed) 396d75c6af9SMina Almasry { 3970db9d74eSMina Almasry long add = 0; 398d75c6af9SMina Almasry struct list_head *head = &resv->regions; 3990db9d74eSMina Almasry long last_accounted_offset = f; 40084448c8eSJakob Koschel struct file_region *iter, *trg = NULL; 40184448c8eSJakob Koschel struct list_head *rg = NULL; 402d75c6af9SMina Almasry 4030db9d74eSMina Almasry if (regions_needed) 4040db9d74eSMina Almasry *regions_needed = 0; 405d75c6af9SMina Almasry 4060db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 40784448c8eSJakob Koschel * [last_accounted_offset, iter->from), at every iteration, with some 4080db9d74eSMina Almasry * bounds checking. 4090db9d74eSMina Almasry */ 41084448c8eSJakob Koschel list_for_each_entry_safe(iter, trg, head, link) { 4110db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 41284448c8eSJakob Koschel if (iter->from < f) { 4130db9d74eSMina Almasry /* If this region ends after the last accounted offset, 4140db9d74eSMina Almasry * then we need to update last_accounted_offset. 4150db9d74eSMina Almasry */ 41684448c8eSJakob Koschel if (iter->to > last_accounted_offset) 41784448c8eSJakob Koschel last_accounted_offset = iter->to; 4180db9d74eSMina Almasry continue; 4190db9d74eSMina Almasry } 420d75c6af9SMina Almasry 4210db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 4220db9d74eSMina Almasry * finished. 4230db9d74eSMina Almasry */ 42484448c8eSJakob Koschel if (iter->from >= t) { 42584448c8eSJakob Koschel rg = iter->link.prev; 426d75c6af9SMina Almasry break; 42784448c8eSJakob Koschel } 428d75c6af9SMina Almasry 42984448c8eSJakob Koschel /* Add an entry for last_accounted_offset -> iter->from, and 4300db9d74eSMina Almasry * update last_accounted_offset. 431d75c6af9SMina Almasry */ 43284448c8eSJakob Koschel if (iter->from > last_accounted_offset) 43384448c8eSJakob Koschel add += hugetlb_resv_map_add(resv, iter->link.prev, 4342103cf9cSPeter Xu last_accounted_offset, 43584448c8eSJakob Koschel iter->from, h, h_cg, 4362103cf9cSPeter Xu regions_needed); 437d75c6af9SMina Almasry 43884448c8eSJakob Koschel last_accounted_offset = iter->to; 4390db9d74eSMina Almasry } 4400db9d74eSMina Almasry 4410db9d74eSMina Almasry /* Handle the case where our range extends beyond 4420db9d74eSMina Almasry * last_accounted_offset. 4430db9d74eSMina Almasry */ 44484448c8eSJakob Koschel if (!rg) 44584448c8eSJakob Koschel rg = head->prev; 4462103cf9cSPeter Xu if (last_accounted_offset < t) 4472103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, 4482103cf9cSPeter Xu t, h, h_cg, regions_needed); 4490db9d74eSMina Almasry 4500db9d74eSMina Almasry return add; 4510db9d74eSMina Almasry } 4520db9d74eSMina Almasry 4530db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4540db9d74eSMina Almasry */ 4550db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4560db9d74eSMina Almasry int regions_needed) 4570db9d74eSMina Almasry __must_hold(&resv->lock) 4580db9d74eSMina Almasry { 4590db9d74eSMina Almasry struct list_head allocated_regions; 4600db9d74eSMina Almasry int to_allocate = 0, i = 0; 4610db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4620db9d74eSMina Almasry 4630db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4640db9d74eSMina Almasry 4650db9d74eSMina Almasry INIT_LIST_HEAD(&allocated_regions); 4660db9d74eSMina Almasry 4670db9d74eSMina Almasry /* 4680db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4690db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 4700db9d74eSMina Almasry * 4710db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 4720db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 4730db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 4740db9d74eSMina Almasry * (adds_in_progress + regions_needed). 4750db9d74eSMina Almasry */ 4760db9d74eSMina Almasry while (resv->region_cache_count < 4770db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 4780db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 4790db9d74eSMina Almasry resv->region_cache_count; 4800db9d74eSMina Almasry 4810db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 482f0953a1bSIngo Molnar * for all the existing adds_in_progress. We should only be 4830db9d74eSMina Almasry * needing to allocate for regions_needed. 4840db9d74eSMina Almasry */ 4850db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 4860db9d74eSMina Almasry 4870db9d74eSMina Almasry spin_unlock(&resv->lock); 4880db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 4890db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 4900db9d74eSMina Almasry if (!trg) 4910db9d74eSMina Almasry goto out_of_memory; 4920db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 4930db9d74eSMina Almasry } 4940db9d74eSMina Almasry 4950db9d74eSMina Almasry spin_lock(&resv->lock); 4960db9d74eSMina Almasry 497d3ec7b6eSWei Yang list_splice(&allocated_regions, &resv->region_cache); 498d3ec7b6eSWei Yang resv->region_cache_count += to_allocate; 4990db9d74eSMina Almasry } 5000db9d74eSMina Almasry 5010db9d74eSMina Almasry return 0; 5020db9d74eSMina Almasry 5030db9d74eSMina Almasry out_of_memory: 5040db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 505d75c6af9SMina Almasry list_del(&rg->link); 506d75c6af9SMina Almasry kfree(rg); 507d75c6af9SMina Almasry } 5080db9d74eSMina Almasry return -ENOMEM; 509d75c6af9SMina Almasry } 510d75c6af9SMina Almasry 5111dd308a7SMike Kravetz /* 5121dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 5130db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 5140db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 5150db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 5160db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 5170db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 518cf3ad20bSMike Kravetz * 5190db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 5200db9d74eSMina Almasry * 5210db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 5220db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 5237c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 5240db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 5250db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 5260db9d74eSMina Almasry * 1 page will only require at most 1 entry. 5271dd308a7SMike Kravetz */ 5280db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 529075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 530075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 53196822904SAndy Whitcroft { 5320db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 53396822904SAndy Whitcroft 5347b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5350db9d74eSMina Almasry retry: 5360db9d74eSMina Almasry 5370db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 538972a3da3SWei Yang add_reservation_in_range(resv, f, t, NULL, NULL, 539972a3da3SWei Yang &actual_regions_needed); 54096822904SAndy Whitcroft 5415e911373SMike Kravetz /* 5420db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 5430db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 5440db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 5450db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 5460db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 5470db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 5480db9d74eSMina Almasry * operation. 5495e911373SMike Kravetz */ 5500db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 5510db9d74eSMina Almasry resv->region_cache_count < 5520db9d74eSMina Almasry resv->adds_in_progress + 5530db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 5540db9d74eSMina Almasry /* region_add operation of range 1 should never need to 5550db9d74eSMina Almasry * allocate file_region entries. 5560db9d74eSMina Almasry */ 5570db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 5585e911373SMike Kravetz 5590db9d74eSMina Almasry if (allocate_file_region_entries( 5600db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 5610db9d74eSMina Almasry return -ENOMEM; 5625e911373SMike Kravetz } 5635e911373SMike Kravetz 5640db9d74eSMina Almasry goto retry; 5650db9d74eSMina Almasry } 566cf3ad20bSMike Kravetz 567972a3da3SWei Yang add = add_reservation_in_range(resv, f, t, h_cg, h, NULL); 5680db9d74eSMina Almasry 5690db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 5700db9d74eSMina Almasry 5717b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 572cf3ad20bSMike Kravetz return add; 57396822904SAndy Whitcroft } 57496822904SAndy Whitcroft 5751dd308a7SMike Kravetz /* 5761dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 5771dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 5781dd308a7SMike Kravetz * represented. This routine is called before a subsequent 5791dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 5801dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 5811dd308a7SMike Kravetz * not change the number of huge pages represented by the 5820db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 5830db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 5840db9d74eSMina Almasry * file_region structure is added. 5850db9d74eSMina Almasry * 5860db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 5870db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 5880db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 5895e911373SMike Kravetz * 5905e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 5915e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 5925e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 5935e911373SMike Kravetz * is needed and can not be allocated. 5941dd308a7SMike Kravetz */ 5950db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 5960db9d74eSMina Almasry long *out_regions_needed) 59796822904SAndy Whitcroft { 59896822904SAndy Whitcroft long chg = 0; 59996822904SAndy Whitcroft 6007b24d861SDavidlohr Bueso spin_lock(&resv->lock); 6015e911373SMike Kravetz 602972a3da3SWei Yang /* Count how many hugepages in this range are NOT represented. */ 603075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 604972a3da3SWei Yang out_regions_needed); 6055e911373SMike Kravetz 6060db9d74eSMina Almasry if (*out_regions_needed == 0) 6070db9d74eSMina Almasry *out_regions_needed = 1; 6085e911373SMike Kravetz 6090db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 6105e911373SMike Kravetz return -ENOMEM; 6115e911373SMike Kravetz 6120db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 61396822904SAndy Whitcroft 6147b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 61596822904SAndy Whitcroft return chg; 61696822904SAndy Whitcroft } 61796822904SAndy Whitcroft 6181dd308a7SMike Kravetz /* 6195e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 6205e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 6215e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 6225e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 6230db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 6240db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 6250db9d74eSMina Almasry * the adds_in_progress counter. 6265e911373SMike Kravetz * 6275e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 6285e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 6295e911373SMike Kravetz * arguments will match the associated region_chg call. 6305e911373SMike Kravetz */ 6310db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 6320db9d74eSMina Almasry long regions_needed) 6335e911373SMike Kravetz { 6345e911373SMike Kravetz spin_lock(&resv->lock); 6355e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 6360db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 6375e911373SMike Kravetz spin_unlock(&resv->lock); 6385e911373SMike Kravetz } 6395e911373SMike Kravetz 6405e911373SMike Kravetz /* 641feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 642feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 643feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 644feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 645feba16e2SMike Kravetz * 646feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 647feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 648feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 649feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 650feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 651feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 652feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 6531dd308a7SMike Kravetz */ 654feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 65596822904SAndy Whitcroft { 6561406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 65796822904SAndy Whitcroft struct file_region *rg, *trg; 658feba16e2SMike Kravetz struct file_region *nrg = NULL; 659feba16e2SMike Kravetz long del = 0; 66096822904SAndy Whitcroft 661feba16e2SMike Kravetz retry: 6627b24d861SDavidlohr Bueso spin_lock(&resv->lock); 663feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 664dbe409e4SMike Kravetz /* 665dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 666dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 667dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 668dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 669dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 670dbe409e4SMike Kravetz */ 671dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 672feba16e2SMike Kravetz continue; 673dbe409e4SMike Kravetz 674feba16e2SMike Kravetz if (rg->from >= t) 67596822904SAndy Whitcroft break; 67696822904SAndy Whitcroft 677feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 678feba16e2SMike Kravetz /* 679feba16e2SMike Kravetz * Check for an entry in the cache before dropping 680feba16e2SMike Kravetz * lock and attempting allocation. 681feba16e2SMike Kravetz */ 682feba16e2SMike Kravetz if (!nrg && 683feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 684feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 685feba16e2SMike Kravetz struct file_region, 686feba16e2SMike Kravetz link); 687feba16e2SMike Kravetz list_del(&nrg->link); 688feba16e2SMike Kravetz resv->region_cache_count--; 68996822904SAndy Whitcroft } 69096822904SAndy Whitcroft 691feba16e2SMike Kravetz if (!nrg) { 692feba16e2SMike Kravetz spin_unlock(&resv->lock); 693feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 694feba16e2SMike Kravetz if (!nrg) 695feba16e2SMike Kravetz return -ENOMEM; 696feba16e2SMike Kravetz goto retry; 697feba16e2SMike Kravetz } 698feba16e2SMike Kravetz 699feba16e2SMike Kravetz del += t - f; 70079aa925bSMike Kravetz hugetlb_cgroup_uncharge_file_region( 701d85aecf2SMiaohe Lin resv, rg, t - f, false); 702feba16e2SMike Kravetz 703feba16e2SMike Kravetz /* New entry for end of split region */ 704feba16e2SMike Kravetz nrg->from = t; 705feba16e2SMike Kravetz nrg->to = rg->to; 706075a61d0SMina Almasry 707075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 708075a61d0SMina Almasry 709feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 710feba16e2SMike Kravetz 711feba16e2SMike Kravetz /* Original entry is trimmed */ 712feba16e2SMike Kravetz rg->to = f; 713feba16e2SMike Kravetz 714feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 715feba16e2SMike Kravetz nrg = NULL; 71696822904SAndy Whitcroft break; 717feba16e2SMike Kravetz } 718feba16e2SMike Kravetz 719feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 720feba16e2SMike Kravetz del += rg->to - rg->from; 721075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 722d85aecf2SMiaohe Lin rg->to - rg->from, true); 72396822904SAndy Whitcroft list_del(&rg->link); 72496822904SAndy Whitcroft kfree(rg); 725feba16e2SMike Kravetz continue; 72696822904SAndy Whitcroft } 7277b24d861SDavidlohr Bueso 728feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 729075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 730d85aecf2SMiaohe Lin t - rg->from, false); 731075a61d0SMina Almasry 73279aa925bSMike Kravetz del += t - rg->from; 73379aa925bSMike Kravetz rg->from = t; 73479aa925bSMike Kravetz } else { /* Trim end of region */ 735075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 736d85aecf2SMiaohe Lin rg->to - f, false); 73779aa925bSMike Kravetz 73879aa925bSMike Kravetz del += rg->to - f; 73979aa925bSMike Kravetz rg->to = f; 740feba16e2SMike Kravetz } 741feba16e2SMike Kravetz } 742feba16e2SMike Kravetz 7437b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 744feba16e2SMike Kravetz kfree(nrg); 745feba16e2SMike Kravetz return del; 74696822904SAndy Whitcroft } 74796822904SAndy Whitcroft 7481dd308a7SMike Kravetz /* 749b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 750b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 751b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 752b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 753b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 754b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 755b5cec28dSMike Kravetz * counts. 756b5cec28dSMike Kravetz */ 75772e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 758b5cec28dSMike Kravetz { 759b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 760b5cec28dSMike Kravetz long rsv_adjust; 761da56388cSMiaohe Lin bool reserved = false; 762b5cec28dSMike Kravetz 763b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 764da56388cSMiaohe Lin if (rsv_adjust > 0) { 765b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 766b5cec28dSMike Kravetz 767da56388cSMiaohe Lin if (!hugetlb_acct_memory(h, 1)) 768da56388cSMiaohe Lin reserved = true; 769da56388cSMiaohe Lin } else if (!rsv_adjust) { 770da56388cSMiaohe Lin reserved = true; 771b5cec28dSMike Kravetz } 772da56388cSMiaohe Lin 773da56388cSMiaohe Lin if (!reserved) 774da56388cSMiaohe Lin pr_warn("hugetlb: Huge Page Reserved count may go negative.\n"); 775b5cec28dSMike Kravetz } 776b5cec28dSMike Kravetz 777b5cec28dSMike Kravetz /* 7781dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 7791dd308a7SMike Kravetz * that intersect with the range [f, t). 7801dd308a7SMike Kravetz */ 7811406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 78284afd99bSAndy Whitcroft { 7831406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 78484afd99bSAndy Whitcroft struct file_region *rg; 78584afd99bSAndy Whitcroft long chg = 0; 78684afd99bSAndy Whitcroft 7877b24d861SDavidlohr Bueso spin_lock(&resv->lock); 78884afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 78984afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 790f2135a4aSWang Sheng-Hui long seg_from; 791f2135a4aSWang Sheng-Hui long seg_to; 79284afd99bSAndy Whitcroft 79384afd99bSAndy Whitcroft if (rg->to <= f) 79484afd99bSAndy Whitcroft continue; 79584afd99bSAndy Whitcroft if (rg->from >= t) 79684afd99bSAndy Whitcroft break; 79784afd99bSAndy Whitcroft 79884afd99bSAndy Whitcroft seg_from = max(rg->from, f); 79984afd99bSAndy Whitcroft seg_to = min(rg->to, t); 80084afd99bSAndy Whitcroft 80184afd99bSAndy Whitcroft chg += seg_to - seg_from; 80284afd99bSAndy Whitcroft } 8037b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 80484afd99bSAndy Whitcroft 80584afd99bSAndy Whitcroft return chg; 80684afd99bSAndy Whitcroft } 80784afd99bSAndy Whitcroft 80896822904SAndy Whitcroft /* 809e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 810e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 811e7c4b0bfSAndy Whitcroft */ 812a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 813a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 814e7c4b0bfSAndy Whitcroft { 815a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 816a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 817e7c4b0bfSAndy Whitcroft } 818e7c4b0bfSAndy Whitcroft 8190fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 8200fe6e20bSNaoya Horiguchi unsigned long address) 8210fe6e20bSNaoya Horiguchi { 8220fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 8230fe6e20bSNaoya Horiguchi } 824dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 8250fe6e20bSNaoya Horiguchi 82684afd99bSAndy Whitcroft /* 82708fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 82808fba699SMel Gorman * cases this will be same size as used by the page table entries. 82908fba699SMel Gorman */ 83008fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 83108fba699SMel Gorman { 83205ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 83305ea8860SDan Williams return vma->vm_ops->pagesize(vma); 83408fba699SMel Gorman return PAGE_SIZE; 83508fba699SMel Gorman } 836f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 83708fba699SMel Gorman 83808fba699SMel Gorman /* 8393340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 8403340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 84109135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 84209135cc5SDan Williams * version of this symbol is required. 8433340289dSMel Gorman */ 84409135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 8453340289dSMel Gorman { 8463340289dSMel Gorman return vma_kernel_pagesize(vma); 8473340289dSMel Gorman } 8483340289dSMel Gorman 8493340289dSMel Gorman /* 85084afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 85184afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 85284afd99bSAndy Whitcroft * alignment. 85384afd99bSAndy Whitcroft */ 85484afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 85584afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 85604f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 85784afd99bSAndy Whitcroft 858a1e78772SMel Gorman /* 859a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 860a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 861a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 862a1e78772SMel Gorman * 863a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 864a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 865a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 866a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 86784afd99bSAndy Whitcroft * 86884afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 86984afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 87084afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 87184afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 87284afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 87384afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 87484afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 87584afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 876a1e78772SMel Gorman */ 877e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 878e7c4b0bfSAndy Whitcroft { 879e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 880e7c4b0bfSAndy Whitcroft } 881e7c4b0bfSAndy Whitcroft 882e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 883e7c4b0bfSAndy Whitcroft unsigned long value) 884e7c4b0bfSAndy Whitcroft { 885e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 886e7c4b0bfSAndy Whitcroft } 887e7c4b0bfSAndy Whitcroft 888e9fe92aeSMina Almasry static void 889e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 890e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 891e9fe92aeSMina Almasry struct hstate *h) 892e9fe92aeSMina Almasry { 893e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 894e9fe92aeSMina Almasry if (!h_cg || !h) { 895e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 896e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 897e9fe92aeSMina Almasry resv_map->css = NULL; 898e9fe92aeSMina Almasry } else { 899e9fe92aeSMina Almasry resv_map->reservation_counter = 900e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 901e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 902e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 903e9fe92aeSMina Almasry } 904e9fe92aeSMina Almasry #endif 905e9fe92aeSMina Almasry } 906e9fe92aeSMina Almasry 9079119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 90884afd99bSAndy Whitcroft { 90984afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 9105e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 9115e911373SMike Kravetz 9125e911373SMike Kravetz if (!resv_map || !rg) { 9135e911373SMike Kravetz kfree(resv_map); 9145e911373SMike Kravetz kfree(rg); 91584afd99bSAndy Whitcroft return NULL; 9165e911373SMike Kravetz } 91784afd99bSAndy Whitcroft 91884afd99bSAndy Whitcroft kref_init(&resv_map->refs); 9197b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 92084afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 92184afd99bSAndy Whitcroft 9225e911373SMike Kravetz resv_map->adds_in_progress = 0; 923e9fe92aeSMina Almasry /* 924e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 925e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 926e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 927e9fe92aeSMina Almasry * reservations are to be un-charged from here. 928e9fe92aeSMina Almasry */ 929e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 9305e911373SMike Kravetz 9315e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 9325e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 9335e911373SMike Kravetz resv_map->region_cache_count = 1; 9345e911373SMike Kravetz 93584afd99bSAndy Whitcroft return resv_map; 93684afd99bSAndy Whitcroft } 93784afd99bSAndy Whitcroft 9389119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 93984afd99bSAndy Whitcroft { 94084afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 9415e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 9425e911373SMike Kravetz struct file_region *rg, *trg; 94384afd99bSAndy Whitcroft 94484afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 945feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 9465e911373SMike Kravetz 9475e911373SMike Kravetz /* ... and any entries left in the cache */ 9485e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 9495e911373SMike Kravetz list_del(&rg->link); 9505e911373SMike Kravetz kfree(rg); 9515e911373SMike Kravetz } 9525e911373SMike Kravetz 9535e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 9545e911373SMike Kravetz 95584afd99bSAndy Whitcroft kfree(resv_map); 95684afd99bSAndy Whitcroft } 95784afd99bSAndy Whitcroft 9584e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 9594e35f483SJoonsoo Kim { 960f27a5136SMike Kravetz /* 961f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 962f27a5136SMike Kravetz * address space within the inode. This original address space 963f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 964f27a5136SMike Kravetz * address space embedded within the inode. 965f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 966f27a5136SMike Kravetz * this may not be true for device special inodes. 967f27a5136SMike Kravetz */ 968f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 9694e35f483SJoonsoo Kim } 9704e35f483SJoonsoo Kim 97184afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 972a1e78772SMel Gorman { 97381d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 9744e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 9754e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 9764e35f483SJoonsoo Kim struct inode *inode = mapping->host; 9774e35f483SJoonsoo Kim 9784e35f483SJoonsoo Kim return inode_resv_map(inode); 9794e35f483SJoonsoo Kim 9804e35f483SJoonsoo Kim } else { 98184afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 98284afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 9834e35f483SJoonsoo Kim } 984a1e78772SMel Gorman } 985a1e78772SMel Gorman 98684afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 987a1e78772SMel Gorman { 98881d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 98981d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 990a1e78772SMel Gorman 99184afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 99284afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 99304f2cbe3SMel Gorman } 99404f2cbe3SMel Gorman 99504f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 99604f2cbe3SMel Gorman { 99781d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 99881d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 999e7c4b0bfSAndy Whitcroft 1000e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 100104f2cbe3SMel Gorman } 100204f2cbe3SMel Gorman 100304f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 100404f2cbe3SMel Gorman { 100581d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1006e7c4b0bfSAndy Whitcroft 1007e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 1008a1e78772SMel Gorman } 1009a1e78772SMel Gorman 101004f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 1011a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 1012a1e78772SMel Gorman { 101381d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1014f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 1015a1e78772SMel Gorman vma->vm_private_data = (void *)0; 1016a1e78772SMel Gorman } 1017a1e78772SMel Gorman 1018550a7d60SMina Almasry /* 1019550a7d60SMina Almasry * Reset and decrement one ref on hugepage private reservation. 1020550a7d60SMina Almasry * Called with mm->mmap_sem writer semaphore held. 1021550a7d60SMina Almasry * This function should be only used by move_vma() and operate on 1022550a7d60SMina Almasry * same sized vma. It should never come here with last ref on the 1023550a7d60SMina Almasry * reservation. 1024550a7d60SMina Almasry */ 1025550a7d60SMina Almasry void clear_vma_resv_huge_pages(struct vm_area_struct *vma) 1026550a7d60SMina Almasry { 1027550a7d60SMina Almasry /* 1028550a7d60SMina Almasry * Clear the old hugetlb private page reservation. 1029550a7d60SMina Almasry * It has already been transferred to new_vma. 1030550a7d60SMina Almasry * 1031550a7d60SMina Almasry * During a mremap() operation of a hugetlb vma we call move_vma() 1032550a7d60SMina Almasry * which copies vma into new_vma and unmaps vma. After the copy 1033550a7d60SMina Almasry * operation both new_vma and vma share a reference to the resv_map 1034550a7d60SMina Almasry * struct, and at that point vma is about to be unmapped. We don't 1035550a7d60SMina Almasry * want to return the reservation to the pool at unmap of vma because 1036550a7d60SMina Almasry * the reservation still lives on in new_vma, so simply decrement the 1037550a7d60SMina Almasry * ref here and remove the resv_map reference from this vma. 1038550a7d60SMina Almasry */ 1039550a7d60SMina Almasry struct resv_map *reservations = vma_resv_map(vma); 1040550a7d60SMina Almasry 1041afe041c2SBui Quang Minh if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 1042afe041c2SBui Quang Minh resv_map_put_hugetlb_cgroup_uncharge_info(reservations); 1043550a7d60SMina Almasry kref_put(&reservations->refs, resv_map_release); 1044afe041c2SBui Quang Minh } 1045550a7d60SMina Almasry 1046550a7d60SMina Almasry reset_vma_resv_huge_pages(vma); 1047550a7d60SMina Almasry } 1048550a7d60SMina Almasry 1049a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 1050559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 1051a1e78772SMel Gorman { 1052af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 1053af0ed73eSJoonsoo Kim /* 1054af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 1055af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 1056af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 1057af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 1058af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 1059af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 1060af0ed73eSJoonsoo Kim * properly, so add work-around here. 1061af0ed73eSJoonsoo Kim */ 1062af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 1063559ec2f8SNicholas Krause return true; 1064af0ed73eSJoonsoo Kim else 1065559ec2f8SNicholas Krause return false; 1066af0ed73eSJoonsoo Kim } 1067a63884e9SJoonsoo Kim 1068a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 10691fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 10701fb1b0e9SMike Kravetz /* 10711fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 10721fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 10731fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 10747c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 10751fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 10761fb1b0e9SMike Kravetz */ 10771fb1b0e9SMike Kravetz if (chg) 10781fb1b0e9SMike Kravetz return false; 10791fb1b0e9SMike Kravetz else 1080559ec2f8SNicholas Krause return true; 10811fb1b0e9SMike Kravetz } 1082a63884e9SJoonsoo Kim 1083a63884e9SJoonsoo Kim /* 1084a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1085a63884e9SJoonsoo Kim * private mappings. 1086a63884e9SJoonsoo Kim */ 108767961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 108867961f9dSMike Kravetz /* 108967961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 109067961f9dSMike Kravetz * could have been performed on the private mapping. 109167961f9dSMike Kravetz * Examine the value of chg to determine if reserves 109267961f9dSMike Kravetz * actually exist or were previously consumed. 109367961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 109467961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 109567961f9dSMike Kravetz * private mappings has different (opposite) semantics 109667961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 109767961f9dSMike Kravetz * has already taken this difference in semantics into 109867961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 109967961f9dSMike Kravetz * as in the shared case above. Code could easily be 110067961f9dSMike Kravetz * combined, but keeping it separate draws attention to 110167961f9dSMike Kravetz * subtle differences. 110267961f9dSMike Kravetz */ 110367961f9dSMike Kravetz if (chg) 110467961f9dSMike Kravetz return false; 110567961f9dSMike Kravetz else 1106559ec2f8SNicholas Krause return true; 110767961f9dSMike Kravetz } 1108a63884e9SJoonsoo Kim 1109559ec2f8SNicholas Krause return false; 1110a1e78772SMel Gorman } 1111a1e78772SMel Gorman 1112a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 11131da177e4SLinus Torvalds { 11141da177e4SLinus Torvalds int nid = page_to_nid(page); 11159487ca60SMike Kravetz 11169487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1117b65a4edaSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1118b65a4edaSMike Kravetz 11190edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1120a5516438SAndi Kleen h->free_huge_pages++; 1121a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 11226c037149SMike Kravetz SetHPageFreed(page); 11231da177e4SLinus Torvalds } 11241da177e4SLinus Torvalds 112594310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1126bf50bab2SNaoya Horiguchi { 1127bf50bab2SNaoya Horiguchi struct page *page; 11281a08ae36SPavel Tatashin bool pin = !!(current->flags & PF_MEMALLOC_PIN); 1129bf50bab2SNaoya Horiguchi 11309487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1131bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 11326077c943SAlex Sierra if (pin && !is_longterm_pinnable_page(page)) 1133bbe88753SJoonsoo Kim continue; 1134bbe88753SJoonsoo Kim 11356664bfc8SWei Yang if (PageHWPoison(page)) 11366664bfc8SWei Yang continue; 1137bbe88753SJoonsoo Kim 11380edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1139a9869b83SNaoya Horiguchi set_page_refcounted(page); 11406c037149SMike Kravetz ClearHPageFreed(page); 1141bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1142bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1143bf50bab2SNaoya Horiguchi return page; 1144bf50bab2SNaoya Horiguchi } 1145bf50bab2SNaoya Horiguchi 11466664bfc8SWei Yang return NULL; 11476664bfc8SWei Yang } 11486664bfc8SWei Yang 11493e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 11503e59fcb0SMichal Hocko nodemask_t *nmask) 115194310cbcSAnshuman Khandual { 11523e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 11533e59fcb0SMichal Hocko struct zonelist *zonelist; 11543e59fcb0SMichal Hocko struct zone *zone; 11553e59fcb0SMichal Hocko struct zoneref *z; 115698fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 11573e59fcb0SMichal Hocko 11583e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 11593e59fcb0SMichal Hocko 11603e59fcb0SMichal Hocko retry_cpuset: 11613e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 11623e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 116394310cbcSAnshuman Khandual struct page *page; 116494310cbcSAnshuman Khandual 11653e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 11663e59fcb0SMichal Hocko continue; 11673e59fcb0SMichal Hocko /* 11683e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 11693e59fcb0SMichal Hocko * zone aware 11703e59fcb0SMichal Hocko */ 11713e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 11723e59fcb0SMichal Hocko continue; 11733e59fcb0SMichal Hocko node = zone_to_nid(zone); 117494310cbcSAnshuman Khandual 117594310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 117694310cbcSAnshuman Khandual if (page) 117794310cbcSAnshuman Khandual return page; 117894310cbcSAnshuman Khandual } 11793e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 11803e59fcb0SMichal Hocko goto retry_cpuset; 11813e59fcb0SMichal Hocko 118294310cbcSAnshuman Khandual return NULL; 118394310cbcSAnshuman Khandual } 118494310cbcSAnshuman Khandual 1185a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1186a5516438SAndi Kleen struct vm_area_struct *vma, 1187af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1188af0ed73eSJoonsoo Kim long chg) 11891da177e4SLinus Torvalds { 1190cfcaa66fSBen Widawsky struct page *page = NULL; 1191480eccf9SLee Schermerhorn struct mempolicy *mpol; 119204ec6264SVlastimil Babka gfp_t gfp_mask; 11933e59fcb0SMichal Hocko nodemask_t *nodemask; 119404ec6264SVlastimil Babka int nid; 11951da177e4SLinus Torvalds 1196a1e78772SMel Gorman /* 1197a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1198a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1199a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1200a1e78772SMel Gorman */ 1201af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1202a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1203c0ff7453SMiao Xie goto err; 1204a1e78772SMel Gorman 120504f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1206a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 12076eab04a8SJustin P. Mattock goto err; 120804f2cbe3SMel Gorman 120904ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 121004ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 1211cfcaa66fSBen Widawsky 1212cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 12133e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1214cfcaa66fSBen Widawsky 1215cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 1216cfcaa66fSBen Widawsky nodemask = NULL; 1217cfcaa66fSBen Widawsky } 1218cfcaa66fSBen Widawsky 1219cfcaa66fSBen Widawsky if (!page) 1220cfcaa66fSBen Widawsky page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1221cfcaa66fSBen Widawsky 12223e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 1223d6995da3SMike Kravetz SetHPageRestoreReserve(page); 1224a63884e9SJoonsoo Kim h->resv_huge_pages--; 1225bf50bab2SNaoya Horiguchi } 1226cc9a6c87SMel Gorman 1227cc9a6c87SMel Gorman mpol_cond_put(mpol); 1228cc9a6c87SMel Gorman return page; 1229cc9a6c87SMel Gorman 1230c0ff7453SMiao Xie err: 1231cc9a6c87SMel Gorman return NULL; 12321da177e4SLinus Torvalds } 12331da177e4SLinus Torvalds 12341cac6f2cSLuiz Capitulino /* 12351cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 12361cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 12371cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 12381cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 12391cac6f2cSLuiz Capitulino * node for alloc or free. 12401cac6f2cSLuiz Capitulino */ 12411cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 12421cac6f2cSLuiz Capitulino { 12430edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 12441cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 12451cac6f2cSLuiz Capitulino 12461cac6f2cSLuiz Capitulino return nid; 12471cac6f2cSLuiz Capitulino } 12481cac6f2cSLuiz Capitulino 12491cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 12501cac6f2cSLuiz Capitulino { 12511cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 12521cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 12531cac6f2cSLuiz Capitulino return nid; 12541cac6f2cSLuiz Capitulino } 12551cac6f2cSLuiz Capitulino 12561cac6f2cSLuiz Capitulino /* 12571cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 12581cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 12591cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 12601cac6f2cSLuiz Capitulino * mask. 12611cac6f2cSLuiz Capitulino */ 12621cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 12631cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 12641cac6f2cSLuiz Capitulino { 12651cac6f2cSLuiz Capitulino int nid; 12661cac6f2cSLuiz Capitulino 12671cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12681cac6f2cSLuiz Capitulino 12691cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 12701cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 12711cac6f2cSLuiz Capitulino 12721cac6f2cSLuiz Capitulino return nid; 12731cac6f2cSLuiz Capitulino } 12741cac6f2cSLuiz Capitulino 12751cac6f2cSLuiz Capitulino /* 127610c6ec49SMike Kravetz * helper for remove_pool_huge_page() - return the previously saved 12771cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 12781cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 12791cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 12801cac6f2cSLuiz Capitulino */ 12811cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 12821cac6f2cSLuiz Capitulino { 12831cac6f2cSLuiz Capitulino int nid; 12841cac6f2cSLuiz Capitulino 12851cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12861cac6f2cSLuiz Capitulino 12871cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 12881cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 12891cac6f2cSLuiz Capitulino 12901cac6f2cSLuiz Capitulino return nid; 12911cac6f2cSLuiz Capitulino } 12921cac6f2cSLuiz Capitulino 12931cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 12941cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12951cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12961cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 12971cac6f2cSLuiz Capitulino nr_nodes--) 12981cac6f2cSLuiz Capitulino 12991cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 13001cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 13011cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 13021cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 13031cac6f2cSLuiz Capitulino nr_nodes--) 13041cac6f2cSLuiz Capitulino 13058531fc6fSMike Kravetz /* used to demote non-gigantic_huge pages as well */ 130634d9e35bSMike Kravetz static void __destroy_compound_gigantic_page(struct page *page, 130734d9e35bSMike Kravetz unsigned int order, bool demote) 1308944d9fecSLuiz Capitulino { 1309944d9fecSLuiz Capitulino int i; 1310944d9fecSLuiz Capitulino int nr_pages = 1 << order; 1311944d9fecSLuiz Capitulino struct page *p = page + 1; 1312944d9fecSLuiz Capitulino 1313c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 131447e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 131547e29d32SJohn Hubbard 1316944d9fecSLuiz Capitulino for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1317a01f4390SMike Kravetz p->mapping = NULL; 13181d798ca3SKirill A. Shutemov clear_compound_head(p); 131934d9e35bSMike Kravetz if (!demote) 1320944d9fecSLuiz Capitulino set_page_refcounted(p); 1321944d9fecSLuiz Capitulino } 1322944d9fecSLuiz Capitulino 1323944d9fecSLuiz Capitulino set_compound_order(page, 0); 13245232c63fSMatthew Wilcox (Oracle) #ifdef CONFIG_64BIT 1325ba9c1201SGerald Schaefer page[1].compound_nr = 0; 13265232c63fSMatthew Wilcox (Oracle) #endif 1327944d9fecSLuiz Capitulino __ClearPageHead(page); 1328944d9fecSLuiz Capitulino } 1329944d9fecSLuiz Capitulino 13308531fc6fSMike Kravetz static void destroy_compound_hugetlb_page_for_demote(struct page *page, 13318531fc6fSMike Kravetz unsigned int order) 13328531fc6fSMike Kravetz { 13338531fc6fSMike Kravetz __destroy_compound_gigantic_page(page, order, true); 13348531fc6fSMike Kravetz } 13358531fc6fSMike Kravetz 13368531fc6fSMike Kravetz #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 133734d9e35bSMike Kravetz static void destroy_compound_gigantic_page(struct page *page, 133834d9e35bSMike Kravetz unsigned int order) 133934d9e35bSMike Kravetz { 134034d9e35bSMike Kravetz __destroy_compound_gigantic_page(page, order, false); 134134d9e35bSMike Kravetz } 134234d9e35bSMike Kravetz 1343d00181b9SKirill A. Shutemov static void free_gigantic_page(struct page *page, unsigned int order) 1344944d9fecSLuiz Capitulino { 1345cf11e85fSRoman Gushchin /* 1346cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1347cf11e85fSRoman Gushchin * cma_release() returns false. 1348cf11e85fSRoman Gushchin */ 1349dbda8feaSBarry Song #ifdef CONFIG_CMA 1350dbda8feaSBarry Song if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)) 1351cf11e85fSRoman Gushchin return; 1352dbda8feaSBarry Song #endif 1353cf11e85fSRoman Gushchin 1354944d9fecSLuiz Capitulino free_contig_range(page_to_pfn(page), 1 << order); 1355944d9fecSLuiz Capitulino } 1356944d9fecSLuiz Capitulino 13574eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 1358d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 1359d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1360944d9fecSLuiz Capitulino { 136104adbc3fSMiaohe Lin unsigned long nr_pages = pages_per_huge_page(h); 1362953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1363953f064aSLi Xinhai nid = numa_mem_id(); 1364944d9fecSLuiz Capitulino 1365dbda8feaSBarry Song #ifdef CONFIG_CMA 1366dbda8feaSBarry Song { 1367cf11e85fSRoman Gushchin struct page *page; 1368cf11e85fSRoman Gushchin int node; 1369cf11e85fSRoman Gushchin 1370953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1371953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1372953f064aSLi Xinhai huge_page_order(h), true); 1373953f064aSLi Xinhai if (page) 1374953f064aSLi Xinhai return page; 1375953f064aSLi Xinhai } 1376953f064aSLi Xinhai 1377953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1378cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1379953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1380cf11e85fSRoman Gushchin continue; 1381cf11e85fSRoman Gushchin 1382cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1383cf11e85fSRoman Gushchin huge_page_order(h), true); 1384cf11e85fSRoman Gushchin if (page) 1385cf11e85fSRoman Gushchin return page; 1386cf11e85fSRoman Gushchin } 1387cf11e85fSRoman Gushchin } 1388953f064aSLi Xinhai } 1389dbda8feaSBarry Song #endif 1390cf11e85fSRoman Gushchin 13915e27a2dfSAnshuman Khandual return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 1392944d9fecSLuiz Capitulino } 1393944d9fecSLuiz Capitulino 13944eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 13954eb0716eSAlexandre Ghiti static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 13964eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 13974eb0716eSAlexandre Ghiti { 13984eb0716eSAlexandre Ghiti return NULL; 13994eb0716eSAlexandre Ghiti } 14004eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1401944d9fecSLuiz Capitulino 1402e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 1403d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 14044eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 14054eb0716eSAlexandre Ghiti { 14064eb0716eSAlexandre Ghiti return NULL; 14074eb0716eSAlexandre Ghiti } 1408d00181b9SKirill A. Shutemov static inline void free_gigantic_page(struct page *page, unsigned int order) { } 1409944d9fecSLuiz Capitulino static inline void destroy_compound_gigantic_page(struct page *page, 1410d00181b9SKirill A. Shutemov unsigned int order) { } 1411944d9fecSLuiz Capitulino #endif 1412944d9fecSLuiz Capitulino 14136eb4e88aSMike Kravetz /* 14146eb4e88aSMike Kravetz * Remove hugetlb page from lists, and update dtor so that page appears 141534d9e35bSMike Kravetz * as just a compound page. 141634d9e35bSMike Kravetz * 141734d9e35bSMike Kravetz * A reference is held on the page, except in the case of demote. 14186eb4e88aSMike Kravetz * 14196eb4e88aSMike Kravetz * Must be called with hugetlb lock held. 14206eb4e88aSMike Kravetz */ 142134d9e35bSMike Kravetz static void __remove_hugetlb_page(struct hstate *h, struct page *page, 142234d9e35bSMike Kravetz bool adjust_surplus, 142334d9e35bSMike Kravetz bool demote) 14246eb4e88aSMike Kravetz { 14256eb4e88aSMike Kravetz int nid = page_to_nid(page); 14266eb4e88aSMike Kravetz 14276eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); 14286eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); 14296eb4e88aSMike Kravetz 14309487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 14316eb4e88aSMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 14326eb4e88aSMike Kravetz return; 14336eb4e88aSMike Kravetz 14346eb4e88aSMike Kravetz list_del(&page->lru); 14356eb4e88aSMike Kravetz 14366eb4e88aSMike Kravetz if (HPageFreed(page)) { 14376eb4e88aSMike Kravetz h->free_huge_pages--; 14386eb4e88aSMike Kravetz h->free_huge_pages_node[nid]--; 14396eb4e88aSMike Kravetz } 14406eb4e88aSMike Kravetz if (adjust_surplus) { 14416eb4e88aSMike Kravetz h->surplus_huge_pages--; 14426eb4e88aSMike Kravetz h->surplus_huge_pages_node[nid]--; 14436eb4e88aSMike Kravetz } 14446eb4e88aSMike Kravetz 1445e32d20c0SMike Kravetz /* 1446e32d20c0SMike Kravetz * Very subtle 1447e32d20c0SMike Kravetz * 1448e32d20c0SMike Kravetz * For non-gigantic pages set the destructor to the normal compound 1449e32d20c0SMike Kravetz * page dtor. This is needed in case someone takes an additional 1450e32d20c0SMike Kravetz * temporary ref to the page, and freeing is delayed until they drop 1451e32d20c0SMike Kravetz * their reference. 1452e32d20c0SMike Kravetz * 1453e32d20c0SMike Kravetz * For gigantic pages set the destructor to the null dtor. This 1454e32d20c0SMike Kravetz * destructor will never be called. Before freeing the gigantic 1455e32d20c0SMike Kravetz * page destroy_compound_gigantic_page will turn the compound page 1456e32d20c0SMike Kravetz * into a simple group of pages. After this the destructor does not 1457e32d20c0SMike Kravetz * apply. 1458e32d20c0SMike Kravetz * 1459e32d20c0SMike Kravetz * This handles the case where more than one ref is held when and 1460e32d20c0SMike Kravetz * after update_and_free_page is called. 146134d9e35bSMike Kravetz * 146234d9e35bSMike Kravetz * In the case of demote we do not ref count the page as it will soon 146334d9e35bSMike Kravetz * be turned into a page of smaller size. 1464e32d20c0SMike Kravetz */ 146534d9e35bSMike Kravetz if (!demote) 14666eb4e88aSMike Kravetz set_page_refcounted(page); 1467e32d20c0SMike Kravetz if (hstate_is_gigantic(h)) 14686eb4e88aSMike Kravetz set_compound_page_dtor(page, NULL_COMPOUND_DTOR); 1469e32d20c0SMike Kravetz else 1470e32d20c0SMike Kravetz set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); 14716eb4e88aSMike Kravetz 14726eb4e88aSMike Kravetz h->nr_huge_pages--; 14736eb4e88aSMike Kravetz h->nr_huge_pages_node[nid]--; 14746eb4e88aSMike Kravetz } 14756eb4e88aSMike Kravetz 147634d9e35bSMike Kravetz static void remove_hugetlb_page(struct hstate *h, struct page *page, 147734d9e35bSMike Kravetz bool adjust_surplus) 147834d9e35bSMike Kravetz { 147934d9e35bSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, false); 148034d9e35bSMike Kravetz } 148134d9e35bSMike Kravetz 14828531fc6fSMike Kravetz static void remove_hugetlb_page_for_demote(struct hstate *h, struct page *page, 14838531fc6fSMike Kravetz bool adjust_surplus) 14848531fc6fSMike Kravetz { 14858531fc6fSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, true); 14868531fc6fSMike Kravetz } 14878531fc6fSMike Kravetz 1488ad2fa371SMuchun Song static void add_hugetlb_page(struct hstate *h, struct page *page, 1489ad2fa371SMuchun Song bool adjust_surplus) 1490ad2fa371SMuchun Song { 1491ad2fa371SMuchun Song int zeroed; 1492ad2fa371SMuchun Song int nid = page_to_nid(page); 1493ad2fa371SMuchun Song 1494ad2fa371SMuchun Song VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page), page); 1495ad2fa371SMuchun Song 1496ad2fa371SMuchun Song lockdep_assert_held(&hugetlb_lock); 1497ad2fa371SMuchun Song 1498ad2fa371SMuchun Song INIT_LIST_HEAD(&page->lru); 1499ad2fa371SMuchun Song h->nr_huge_pages++; 1500ad2fa371SMuchun Song h->nr_huge_pages_node[nid]++; 1501ad2fa371SMuchun Song 1502ad2fa371SMuchun Song if (adjust_surplus) { 1503ad2fa371SMuchun Song h->surplus_huge_pages++; 1504ad2fa371SMuchun Song h->surplus_huge_pages_node[nid]++; 1505ad2fa371SMuchun Song } 1506ad2fa371SMuchun Song 1507ad2fa371SMuchun Song set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1508ad2fa371SMuchun Song set_page_private(page, 0); 1509ad2fa371SMuchun Song SetHPageVmemmapOptimized(page); 1510ad2fa371SMuchun Song 1511ad2fa371SMuchun Song /* 1512b65a4edaSMike Kravetz * This page is about to be managed by the hugetlb allocator and 1513b65a4edaSMike Kravetz * should have no users. Drop our reference, and check for others 1514b65a4edaSMike Kravetz * just in case. 1515ad2fa371SMuchun Song */ 1516ad2fa371SMuchun Song zeroed = put_page_testzero(page); 1517b65a4edaSMike Kravetz if (!zeroed) 1518b65a4edaSMike Kravetz /* 1519b65a4edaSMike Kravetz * It is VERY unlikely soneone else has taken a ref on 1520b65a4edaSMike Kravetz * the page. In this case, we simply return as the 1521b65a4edaSMike Kravetz * hugetlb destructor (free_huge_page) will be called 1522b65a4edaSMike Kravetz * when this other ref is dropped. 1523b65a4edaSMike Kravetz */ 1524b65a4edaSMike Kravetz return; 1525b65a4edaSMike Kravetz 1526ad2fa371SMuchun Song arch_clear_hugepage_flags(page); 1527ad2fa371SMuchun Song enqueue_huge_page(h, page); 1528ad2fa371SMuchun Song } 1529ad2fa371SMuchun Song 1530b65d4adbSMuchun Song static void __update_and_free_page(struct hstate *h, struct page *page) 15316af2acb6SAdam Litke { 15326af2acb6SAdam Litke int i; 1533dbfee5aeSMike Kravetz struct page *subpage = page; 1534a5516438SAndi Kleen 15354eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1536944d9fecSLuiz Capitulino return; 153718229df5SAndy Whitcroft 1538161df60eSNaoya Horiguchi /* 1539161df60eSNaoya Horiguchi * If we don't know which subpages are hwpoisoned, we can't free 1540161df60eSNaoya Horiguchi * the hugepage, so it's leaked intentionally. 1541161df60eSNaoya Horiguchi */ 1542161df60eSNaoya Horiguchi if (HPageRawHwpUnreliable(page)) 1543161df60eSNaoya Horiguchi return; 1544161df60eSNaoya Horiguchi 15456213834cSMuchun Song if (hugetlb_vmemmap_restore(h, page)) { 1546ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 1547ad2fa371SMuchun Song /* 1548ad2fa371SMuchun Song * If we cannot allocate vmemmap pages, just refuse to free the 1549ad2fa371SMuchun Song * page and put the page back on the hugetlb free list and treat 1550ad2fa371SMuchun Song * as a surplus page. 1551ad2fa371SMuchun Song */ 1552ad2fa371SMuchun Song add_hugetlb_page(h, page, true); 1553ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1554ad2fa371SMuchun Song return; 1555ad2fa371SMuchun Song } 1556ad2fa371SMuchun Song 1557161df60eSNaoya Horiguchi /* 1558161df60eSNaoya Horiguchi * Move PageHWPoison flag from head page to the raw error pages, 1559161df60eSNaoya Horiguchi * which makes any healthy subpages reusable. 1560161df60eSNaoya Horiguchi */ 1561161df60eSNaoya Horiguchi if (unlikely(PageHWPoison(page))) 1562161df60eSNaoya Horiguchi hugetlb_clear_page_hwpoison(page); 1563161df60eSNaoya Horiguchi 1564dbfee5aeSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 1565dbfee5aeSMike Kravetz i++, subpage = mem_map_next(subpage, page, i)) { 1566dbfee5aeSMike Kravetz subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 156732f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1568a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1569a7407a27SLuiz Capitulino 1 << PG_writeback); 15706af2acb6SAdam Litke } 1571a01f4390SMike Kravetz 1572a01f4390SMike Kravetz /* 1573a01f4390SMike Kravetz * Non-gigantic pages demoted from CMA allocated gigantic pages 1574a01f4390SMike Kravetz * need to be given back to CMA in free_gigantic_page. 1575a01f4390SMike Kravetz */ 1576a01f4390SMike Kravetz if (hstate_is_gigantic(h) || 1577a01f4390SMike Kravetz hugetlb_cma_page(page, huge_page_order(h))) { 1578944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1579944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1580944d9fecSLuiz Capitulino } else { 1581a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 15826af2acb6SAdam Litke } 1583944d9fecSLuiz Capitulino } 15846af2acb6SAdam Litke 1585b65d4adbSMuchun Song /* 1586b65d4adbSMuchun Song * As update_and_free_page() can be called under any context, so we cannot 1587b65d4adbSMuchun Song * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the 1588b65d4adbSMuchun Song * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate 1589b65d4adbSMuchun Song * the vmemmap pages. 1590b65d4adbSMuchun Song * 1591b65d4adbSMuchun Song * free_hpage_workfn() locklessly retrieves the linked list of pages to be 1592b65d4adbSMuchun Song * freed and frees them one-by-one. As the page->mapping pointer is going 1593b65d4adbSMuchun Song * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node 1594b65d4adbSMuchun Song * structure of a lockless linked list of huge pages to be freed. 1595b65d4adbSMuchun Song */ 1596b65d4adbSMuchun Song static LLIST_HEAD(hpage_freelist); 1597b65d4adbSMuchun Song 1598b65d4adbSMuchun Song static void free_hpage_workfn(struct work_struct *work) 1599b65d4adbSMuchun Song { 1600b65d4adbSMuchun Song struct llist_node *node; 1601b65d4adbSMuchun Song 1602b65d4adbSMuchun Song node = llist_del_all(&hpage_freelist); 1603b65d4adbSMuchun Song 1604b65d4adbSMuchun Song while (node) { 1605b65d4adbSMuchun Song struct page *page; 1606b65d4adbSMuchun Song struct hstate *h; 1607b65d4adbSMuchun Song 1608b65d4adbSMuchun Song page = container_of((struct address_space **)node, 1609b65d4adbSMuchun Song struct page, mapping); 1610b65d4adbSMuchun Song node = node->next; 1611b65d4adbSMuchun Song page->mapping = NULL; 1612b65d4adbSMuchun Song /* 1613b65d4adbSMuchun Song * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate() 1614b65d4adbSMuchun Song * is going to trigger because a previous call to 1615b65d4adbSMuchun Song * remove_hugetlb_page() will set_compound_page_dtor(page, 1616b65d4adbSMuchun Song * NULL_COMPOUND_DTOR), so do not use page_hstate() directly. 1617b65d4adbSMuchun Song */ 1618b65d4adbSMuchun Song h = size_to_hstate(page_size(page)); 1619b65d4adbSMuchun Song 1620b65d4adbSMuchun Song __update_and_free_page(h, page); 1621b65d4adbSMuchun Song 1622b65d4adbSMuchun Song cond_resched(); 1623b65d4adbSMuchun Song } 1624b65d4adbSMuchun Song } 1625b65d4adbSMuchun Song static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1626b65d4adbSMuchun Song 1627b65d4adbSMuchun Song static inline void flush_free_hpage_work(struct hstate *h) 1628b65d4adbSMuchun Song { 16296213834cSMuchun Song if (hugetlb_vmemmap_optimizable(h)) 1630b65d4adbSMuchun Song flush_work(&free_hpage_work); 1631b65d4adbSMuchun Song } 1632b65d4adbSMuchun Song 1633b65d4adbSMuchun Song static void update_and_free_page(struct hstate *h, struct page *page, 1634b65d4adbSMuchun Song bool atomic) 1635b65d4adbSMuchun Song { 1636ad2fa371SMuchun Song if (!HPageVmemmapOptimized(page) || !atomic) { 1637b65d4adbSMuchun Song __update_and_free_page(h, page); 1638b65d4adbSMuchun Song return; 1639b65d4adbSMuchun Song } 1640b65d4adbSMuchun Song 1641b65d4adbSMuchun Song /* 1642b65d4adbSMuchun Song * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages. 1643b65d4adbSMuchun Song * 1644b65d4adbSMuchun Song * Only call schedule_work() if hpage_freelist is previously 1645b65d4adbSMuchun Song * empty. Otherwise, schedule_work() had been called but the workfn 1646b65d4adbSMuchun Song * hasn't retrieved the list yet. 1647b65d4adbSMuchun Song */ 1648b65d4adbSMuchun Song if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist)) 1649b65d4adbSMuchun Song schedule_work(&free_hpage_work); 1650b65d4adbSMuchun Song } 1651b65d4adbSMuchun Song 165210c6ec49SMike Kravetz static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list) 165310c6ec49SMike Kravetz { 165410c6ec49SMike Kravetz struct page *page, *t_page; 165510c6ec49SMike Kravetz 165610c6ec49SMike Kravetz list_for_each_entry_safe(page, t_page, list, lru) { 1657b65d4adbSMuchun Song update_and_free_page(h, page, false); 165810c6ec49SMike Kravetz cond_resched(); 165910c6ec49SMike Kravetz } 166010c6ec49SMike Kravetz } 166110c6ec49SMike Kravetz 1662e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1663e5ff2159SAndi Kleen { 1664e5ff2159SAndi Kleen struct hstate *h; 1665e5ff2159SAndi Kleen 1666e5ff2159SAndi Kleen for_each_hstate(h) { 1667e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1668e5ff2159SAndi Kleen return h; 1669e5ff2159SAndi Kleen } 1670e5ff2159SAndi Kleen return NULL; 1671e5ff2159SAndi Kleen } 1672e5ff2159SAndi Kleen 1673db71ef79SMike Kravetz void free_huge_page(struct page *page) 167427a85ef1SDavid Gibson { 1675a5516438SAndi Kleen /* 1676a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1677a5516438SAndi Kleen * compound page destructor. 1678a5516438SAndi Kleen */ 1679e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 16807893d1d5SAdam Litke int nid = page_to_nid(page); 1681d6995da3SMike Kravetz struct hugepage_subpool *spool = hugetlb_page_subpool(page); 168207443a85SJoonsoo Kim bool restore_reserve; 1683db71ef79SMike Kravetz unsigned long flags; 168427a85ef1SDavid Gibson 1685b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1686b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 16878ace22bcSYongkai Wu 1688d6995da3SMike Kravetz hugetlb_set_page_subpool(page, NULL); 168978fbe906SDavid Hildenbrand if (PageAnon(page)) 169078fbe906SDavid Hildenbrand __ClearPageAnonExclusive(page); 16918ace22bcSYongkai Wu page->mapping = NULL; 1692d6995da3SMike Kravetz restore_reserve = HPageRestoreReserve(page); 1693d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 169427a85ef1SDavid Gibson 16951c5ecae3SMike Kravetz /* 1696d6995da3SMike Kravetz * If HPageRestoreReserve was set on page, page allocation consumed a 16970919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 16980919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 16990919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 17006c26d310SMiaohe Lin * reservation, do not call hugepage_subpool_put_pages() as this will 17010919e1b6SMike Kravetz * remove the reserved page from the subpool. 17020919e1b6SMike Kravetz */ 17030919e1b6SMike Kravetz if (!restore_reserve) { 17040919e1b6SMike Kravetz /* 17050919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 17060919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 17070919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 17080919e1b6SMike Kravetz * operation. 17091c5ecae3SMike Kravetz */ 17101c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 17111c5ecae3SMike Kravetz restore_reserve = true; 17120919e1b6SMike Kravetz } 17131c5ecae3SMike Kravetz 1714db71ef79SMike Kravetz spin_lock_irqsave(&hugetlb_lock, flags); 17158f251a3dSMike Kravetz ClearHPageMigratable(page); 17166d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 17176d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 171808cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 171908cf9fafSMina Almasry pages_per_huge_page(h), page); 172007443a85SJoonsoo Kim if (restore_reserve) 172107443a85SJoonsoo Kim h->resv_huge_pages++; 172207443a85SJoonsoo Kim 17239157c311SMike Kravetz if (HPageTemporary(page)) { 17246eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 1725db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1726b65d4adbSMuchun Song update_and_free_page(h, page, true); 1727ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 17280edaecfaSAneesh Kumar K.V /* remove the page from active list */ 17296eb4e88aSMike Kravetz remove_hugetlb_page(h, page, true); 1730db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1731b65d4adbSMuchun Song update_and_free_page(h, page, true); 17327893d1d5SAdam Litke } else { 17335d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1734a5516438SAndi Kleen enqueue_huge_page(h, page); 1735db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 173627a85ef1SDavid Gibson } 17371121828aSMike Kravetz } 173827a85ef1SDavid Gibson 1739d3d99fccSOscar Salvador /* 1740d3d99fccSOscar Salvador * Must be called with the hugetlb lock held 1741d3d99fccSOscar Salvador */ 1742d3d99fccSOscar Salvador static void __prep_account_new_huge_page(struct hstate *h, int nid) 1743d3d99fccSOscar Salvador { 1744d3d99fccSOscar Salvador lockdep_assert_held(&hugetlb_lock); 1745d3d99fccSOscar Salvador h->nr_huge_pages++; 1746d3d99fccSOscar Salvador h->nr_huge_pages_node[nid]++; 1747d3d99fccSOscar Salvador } 1748d3d99fccSOscar Salvador 1749f41f2ed4SMuchun Song static void __prep_new_huge_page(struct hstate *h, struct page *page) 1750b7ba30c6SAndi Kleen { 17516213834cSMuchun Song hugetlb_vmemmap_optimize(h, page); 17520edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1753f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1754ff546117SMike Kravetz hugetlb_set_page_subpool(page, NULL); 17559dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 17561adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 1757d3d99fccSOscar Salvador } 1758d3d99fccSOscar Salvador 1759d3d99fccSOscar Salvador static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1760d3d99fccSOscar Salvador { 1761f41f2ed4SMuchun Song __prep_new_huge_page(h, page); 1762db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 1763d3d99fccSOscar Salvador __prep_account_new_huge_page(h, nid); 1764db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1765b7ba30c6SAndi Kleen } 1766b7ba30c6SAndi Kleen 176734d9e35bSMike Kravetz static bool __prep_compound_gigantic_page(struct page *page, unsigned int order, 176834d9e35bSMike Kravetz bool demote) 176920a0307cSWu Fengguang { 17707118fc29SMike Kravetz int i, j; 177120a0307cSWu Fengguang int nr_pages = 1 << order; 177220a0307cSWu Fengguang struct page *p = page + 1; 177320a0307cSWu Fengguang 177420a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 177520a0307cSWu Fengguang set_compound_order(page, order); 1776ef5a22beSAndrea Arcangeli __ClearPageReserved(page); 1777de09d31dSKirill A. Shutemov __SetPageHead(page); 177820a0307cSWu Fengguang for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1779ef5a22beSAndrea Arcangeli /* 1780ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1781ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1782ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 17837c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1784ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1785ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1786ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1787ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1788ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1789ef5a22beSAndrea Arcangeli * after get_user_pages(). 1790ef5a22beSAndrea Arcangeli */ 1791ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 17927118fc29SMike Kravetz /* 17937118fc29SMike Kravetz * Subtle and very unlikely 17947118fc29SMike Kravetz * 17957118fc29SMike Kravetz * Gigantic 'page allocators' such as memblock or cma will 17967118fc29SMike Kravetz * return a set of pages with each page ref counted. We need 17977118fc29SMike Kravetz * to turn this set of pages into a compound page with tail 17987118fc29SMike Kravetz * page ref counts set to zero. Code such as speculative page 17997118fc29SMike Kravetz * cache adding could take a ref on a 'to be' tail page. 18007118fc29SMike Kravetz * We need to respect any increased ref count, and only set 18017118fc29SMike Kravetz * the ref count to zero if count is currently 1. If count 1802416d85edSMike Kravetz * is not 1, we return an error. An error return indicates 1803416d85edSMike Kravetz * the set of pages can not be converted to a gigantic page. 1804416d85edSMike Kravetz * The caller who allocated the pages should then discard the 1805416d85edSMike Kravetz * pages using the appropriate free interface. 180634d9e35bSMike Kravetz * 180734d9e35bSMike Kravetz * In the case of demote, the ref count will be zero. 18087118fc29SMike Kravetz */ 180934d9e35bSMike Kravetz if (!demote) { 18107118fc29SMike Kravetz if (!page_ref_freeze(p, 1)) { 1811416d85edSMike Kravetz pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n"); 18127118fc29SMike Kravetz goto out_error; 18137118fc29SMike Kravetz } 181434d9e35bSMike Kravetz } else { 181534d9e35bSMike Kravetz VM_BUG_ON_PAGE(page_count(p), p); 181634d9e35bSMike Kravetz } 18171d798ca3SKirill A. Shutemov set_compound_head(p, page); 181820a0307cSWu Fengguang } 1819b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 182047e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 18217118fc29SMike Kravetz return true; 18227118fc29SMike Kravetz 18237118fc29SMike Kravetz out_error: 18247118fc29SMike Kravetz /* undo tail page modifications made above */ 18257118fc29SMike Kravetz p = page + 1; 18267118fc29SMike Kravetz for (j = 1; j < i; j++, p = mem_map_next(p, page, j)) { 18277118fc29SMike Kravetz clear_compound_head(p); 18287118fc29SMike Kravetz set_page_refcounted(p); 18297118fc29SMike Kravetz } 18307118fc29SMike Kravetz /* need to clear PG_reserved on remaining tail pages */ 18317118fc29SMike Kravetz for (; j < nr_pages; j++, p = mem_map_next(p, page, j)) 18327118fc29SMike Kravetz __ClearPageReserved(p); 18337118fc29SMike Kravetz set_compound_order(page, 0); 18345232c63fSMatthew Wilcox (Oracle) #ifdef CONFIG_64BIT 18357118fc29SMike Kravetz page[1].compound_nr = 0; 18365232c63fSMatthew Wilcox (Oracle) #endif 18377118fc29SMike Kravetz __ClearPageHead(page); 18387118fc29SMike Kravetz return false; 183920a0307cSWu Fengguang } 184020a0307cSWu Fengguang 184134d9e35bSMike Kravetz static bool prep_compound_gigantic_page(struct page *page, unsigned int order) 184234d9e35bSMike Kravetz { 184334d9e35bSMike Kravetz return __prep_compound_gigantic_page(page, order, false); 184434d9e35bSMike Kravetz } 184534d9e35bSMike Kravetz 18468531fc6fSMike Kravetz static bool prep_compound_gigantic_page_for_demote(struct page *page, 18478531fc6fSMike Kravetz unsigned int order) 18488531fc6fSMike Kravetz { 18498531fc6fSMike Kravetz return __prep_compound_gigantic_page(page, order, true); 18508531fc6fSMike Kravetz } 18518531fc6fSMike Kravetz 18527795912cSAndrew Morton /* 18537795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 18547795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 18557795912cSAndrew Morton * details. 18567795912cSAndrew Morton */ 185720a0307cSWu Fengguang int PageHuge(struct page *page) 185820a0307cSWu Fengguang { 185920a0307cSWu Fengguang if (!PageCompound(page)) 186020a0307cSWu Fengguang return 0; 186120a0307cSWu Fengguang 186220a0307cSWu Fengguang page = compound_head(page); 1863f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 186420a0307cSWu Fengguang } 186543131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 186643131e14SNaoya Horiguchi 186727c73ae7SAndrea Arcangeli /* 186827c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 186927c73ae7SAndrea Arcangeli * normal or transparent huge pages. 187027c73ae7SAndrea Arcangeli */ 187127c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 187227c73ae7SAndrea Arcangeli { 187327c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 187427c73ae7SAndrea Arcangeli return 0; 187527c73ae7SAndrea Arcangeli 1876d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 187727c73ae7SAndrea Arcangeli } 18784e936eccSDavid Howells EXPORT_SYMBOL_GPL(PageHeadHuge); 187927c73ae7SAndrea Arcangeli 1880c0d0381aSMike Kravetz /* 1881c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1882c0d0381aSMike Kravetz * 1883336bf30eSMike Kravetz * Upon entry, the page is locked which means that page_mapping() is 1884336bf30eSMike Kravetz * stable. Due to locking order, we can only trylock_write. If we can 1885336bf30eSMike Kravetz * not get the lock, simply return NULL to caller. 1886c0d0381aSMike Kravetz */ 1887c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1888c0d0381aSMike Kravetz { 1889336bf30eSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1890c0d0381aSMike Kravetz 1891c0d0381aSMike Kravetz if (!mapping) 1892c0d0381aSMike Kravetz return mapping; 1893c0d0381aSMike Kravetz 1894c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1895c0d0381aSMike Kravetz return mapping; 1896c0d0381aSMike Kravetz 1897c0d0381aSMike Kravetz return NULL; 1898c0d0381aSMike Kravetz } 1899c0d0381aSMike Kravetz 1900fe19bd3dSHugh Dickins pgoff_t hugetlb_basepage_index(struct page *page) 190113d60f4bSZhang Yi { 190213d60f4bSZhang Yi struct page *page_head = compound_head(page); 190313d60f4bSZhang Yi pgoff_t index = page_index(page_head); 190413d60f4bSZhang Yi unsigned long compound_idx; 190513d60f4bSZhang Yi 190613d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 190713d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 190813d60f4bSZhang Yi else 190913d60f4bSZhang Yi compound_idx = page - page_head; 191013d60f4bSZhang Yi 191113d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 191213d60f4bSZhang Yi } 191313d60f4bSZhang Yi 19140c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1915f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1916f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19171da177e4SLinus Torvalds { 1918af0fb9dfSMichal Hocko int order = huge_page_order(h); 19191da177e4SLinus Torvalds struct page *page; 1920f60858f9SMike Kravetz bool alloc_try_hard = true; 1921f96efd58SJoe Jin 1922f60858f9SMike Kravetz /* 1923f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1924f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1925f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1926f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1927f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1928f60858f9SMike Kravetz */ 1929f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1930f60858f9SMike Kravetz alloc_try_hard = false; 1931f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1932f60858f9SMike Kravetz if (alloc_try_hard) 1933f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1934af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1935af0fb9dfSMichal Hocko nid = numa_mem_id(); 193684172f4bSMatthew Wilcox (Oracle) page = __alloc_pages(gfp_mask, order, nid, nmask); 1937af0fb9dfSMichal Hocko if (page) 1938af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1939af0fb9dfSMichal Hocko else 1940af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 194163b4613cSNishanth Aravamudan 1942f60858f9SMike Kravetz /* 1943f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1944f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1945f60858f9SMike Kravetz * normal 'try hard' allocations. 1946f60858f9SMike Kravetz */ 1947f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1948f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1949f60858f9SMike Kravetz 1950f60858f9SMike Kravetz /* 1951f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1952f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1953f60858f9SMike Kravetz * overall state change. 1954f60858f9SMike Kravetz */ 1955f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1956f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1957f60858f9SMike Kravetz 195863b4613cSNishanth Aravamudan return page; 195963b4613cSNishanth Aravamudan } 196063b4613cSNishanth Aravamudan 1961af0fb9dfSMichal Hocko /* 19620c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 19630c397daeSMichal Hocko * should use this function to get new hugetlb pages 19640c397daeSMichal Hocko */ 19650c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 1966f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1967f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19680c397daeSMichal Hocko { 19690c397daeSMichal Hocko struct page *page; 19707118fc29SMike Kravetz bool retry = false; 19710c397daeSMichal Hocko 19727118fc29SMike Kravetz retry: 19730c397daeSMichal Hocko if (hstate_is_gigantic(h)) 19740c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 19750c397daeSMichal Hocko else 19760c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 1977f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 19780c397daeSMichal Hocko if (!page) 19790c397daeSMichal Hocko return NULL; 19800c397daeSMichal Hocko 19817118fc29SMike Kravetz if (hstate_is_gigantic(h)) { 19827118fc29SMike Kravetz if (!prep_compound_gigantic_page(page, huge_page_order(h))) { 19837118fc29SMike Kravetz /* 19847118fc29SMike Kravetz * Rare failure to convert pages to compound page. 19857118fc29SMike Kravetz * Free pages and try again - ONCE! 19867118fc29SMike Kravetz */ 19877118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 19887118fc29SMike Kravetz if (!retry) { 19897118fc29SMike Kravetz retry = true; 19907118fc29SMike Kravetz goto retry; 19917118fc29SMike Kravetz } 19927118fc29SMike Kravetz return NULL; 19937118fc29SMike Kravetz } 19947118fc29SMike Kravetz } 19950c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 19960c397daeSMichal Hocko 19970c397daeSMichal Hocko return page; 19980c397daeSMichal Hocko } 19990c397daeSMichal Hocko 20000c397daeSMichal Hocko /* 2001af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 2002af0fb9dfSMichal Hocko * manner. 2003af0fb9dfSMichal Hocko */ 2004f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 2005f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 2006b2261026SJoonsoo Kim { 2007b2261026SJoonsoo Kim struct page *page; 2008b2261026SJoonsoo Kim int nr_nodes, node; 2009af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2010b2261026SJoonsoo Kim 2011b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 2012f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 2013f60858f9SMike Kravetz node_alloc_noretry); 2014af0fb9dfSMichal Hocko if (page) 2015b2261026SJoonsoo Kim break; 2016b2261026SJoonsoo Kim } 2017b2261026SJoonsoo Kim 2018af0fb9dfSMichal Hocko if (!page) 2019af0fb9dfSMichal Hocko return 0; 2020b2261026SJoonsoo Kim 2021af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 2022af0fb9dfSMichal Hocko 2023af0fb9dfSMichal Hocko return 1; 2024b2261026SJoonsoo Kim } 2025b2261026SJoonsoo Kim 2026e8c5c824SLee Schermerhorn /* 202710c6ec49SMike Kravetz * Remove huge page from pool from next node to free. Attempt to keep 202810c6ec49SMike Kravetz * persistent huge pages more or less balanced over allowed nodes. 202910c6ec49SMike Kravetz * This routine only 'removes' the hugetlb page. The caller must make 203010c6ec49SMike Kravetz * an additional call to free the page to low level allocators. 2031e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 2032e8c5c824SLee Schermerhorn */ 203310c6ec49SMike Kravetz static struct page *remove_pool_huge_page(struct hstate *h, 203410c6ec49SMike Kravetz nodemask_t *nodes_allowed, 20356ae11b27SLee Schermerhorn bool acct_surplus) 2036e8c5c824SLee Schermerhorn { 2037b2261026SJoonsoo Kim int nr_nodes, node; 203810c6ec49SMike Kravetz struct page *page = NULL; 2039e8c5c824SLee Schermerhorn 20409487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2041b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2042685f3457SLee Schermerhorn /* 2043685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 2044685f3457SLee Schermerhorn * nodes with surplus pages. 2045685f3457SLee Schermerhorn */ 2046b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 2047b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 204810c6ec49SMike Kravetz page = list_entry(h->hugepage_freelists[node].next, 2049e8c5c824SLee Schermerhorn struct page, lru); 20506eb4e88aSMike Kravetz remove_hugetlb_page(h, page, acct_surplus); 20519a76db09SLee Schermerhorn break; 2052e8c5c824SLee Schermerhorn } 2053b2261026SJoonsoo Kim } 2054e8c5c824SLee Schermerhorn 205510c6ec49SMike Kravetz return page; 2056e8c5c824SLee Schermerhorn } 2057e8c5c824SLee Schermerhorn 2058c8721bbbSNaoya Horiguchi /* 2059c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 2060faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 2061faf53defSNaoya Horiguchi * This function returns values like below: 2062faf53defSNaoya Horiguchi * 2063ad2fa371SMuchun Song * -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages 2064ad2fa371SMuchun Song * when the system is under memory pressure and the feature of 2065ad2fa371SMuchun Song * freeing unused vmemmap pages associated with each hugetlb page 2066ad2fa371SMuchun Song * is enabled. 2067faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 2068faf53defSNaoya Horiguchi * (allocated or reserved.) 2069faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 2070faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 2071c8721bbbSNaoya Horiguchi */ 2072c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 2073c8721bbbSNaoya Horiguchi { 20746bc9b564SNaoya Horiguchi int rc = -EBUSY; 2075082d5b6bSGerald Schaefer 20767ffddd49SMuchun Song retry: 2077faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 2078faf53defSNaoya Horiguchi if (!PageHuge(page)) 2079faf53defSNaoya Horiguchi return 0; 2080faf53defSNaoya Horiguchi 2081db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2082faf53defSNaoya Horiguchi if (!PageHuge(page)) { 2083faf53defSNaoya Horiguchi rc = 0; 2084faf53defSNaoya Horiguchi goto out; 2085faf53defSNaoya Horiguchi } 2086faf53defSNaoya Horiguchi 2087faf53defSNaoya Horiguchi if (!page_count(page)) { 20882247bb33SGerald Schaefer struct page *head = compound_head(page); 20892247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 20906bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 2091082d5b6bSGerald Schaefer goto out; 20927ffddd49SMuchun Song 20937ffddd49SMuchun Song /* 20947ffddd49SMuchun Song * We should make sure that the page is already on the free list 20957ffddd49SMuchun Song * when it is dissolved. 20967ffddd49SMuchun Song */ 20976c037149SMike Kravetz if (unlikely(!HPageFreed(head))) { 2098db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 20997ffddd49SMuchun Song cond_resched(); 21007ffddd49SMuchun Song 21017ffddd49SMuchun Song /* 21027ffddd49SMuchun Song * Theoretically, we should return -EBUSY when we 21037ffddd49SMuchun Song * encounter this race. In fact, we have a chance 21047ffddd49SMuchun Song * to successfully dissolve the page if we do a 21057ffddd49SMuchun Song * retry. Because the race window is quite small. 21067ffddd49SMuchun Song * If we seize this opportunity, it is an optimization 21077ffddd49SMuchun Song * for increasing the success rate of dissolving page. 21087ffddd49SMuchun Song */ 21097ffddd49SMuchun Song goto retry; 21107ffddd49SMuchun Song } 21117ffddd49SMuchun Song 2112ad2fa371SMuchun Song remove_hugetlb_page(h, head, false); 2113ad2fa371SMuchun Song h->max_huge_pages--; 2114ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2115ad2fa371SMuchun Song 2116c3114a84SAnshuman Khandual /* 2117ad2fa371SMuchun Song * Normally update_and_free_page will allocate required vmemmmap 2118ad2fa371SMuchun Song * before freeing the page. update_and_free_page will fail to 2119ad2fa371SMuchun Song * free the page if it can not allocate required vmemmap. We 2120ad2fa371SMuchun Song * need to adjust max_huge_pages if the page is not freed. 2121ad2fa371SMuchun Song * Attempt to allocate vmemmmap here so that we can take 2122ad2fa371SMuchun Song * appropriate action on failure. 2123ad2fa371SMuchun Song */ 21246213834cSMuchun Song rc = hugetlb_vmemmap_restore(h, head); 2125ad2fa371SMuchun Song if (!rc) { 2126b65d4adbSMuchun Song update_and_free_page(h, head, false); 2127ad2fa371SMuchun Song } else { 2128ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 2129ad2fa371SMuchun Song add_hugetlb_page(h, head, false); 2130ad2fa371SMuchun Song h->max_huge_pages++; 2131ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2132ad2fa371SMuchun Song } 2133ad2fa371SMuchun Song 2134ad2fa371SMuchun Song return rc; 2135c8721bbbSNaoya Horiguchi } 2136082d5b6bSGerald Schaefer out: 2137db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2138082d5b6bSGerald Schaefer return rc; 2139c8721bbbSNaoya Horiguchi } 2140c8721bbbSNaoya Horiguchi 2141c8721bbbSNaoya Horiguchi /* 2142c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 2143c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 21442247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 21452247bb33SGerald Schaefer * part of it lies within the given range. 2146082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 2147082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 2148c8721bbbSNaoya Horiguchi */ 2149082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 2150c8721bbbSNaoya Horiguchi { 2151c8721bbbSNaoya Horiguchi unsigned long pfn; 2152eb03aa00SGerald Schaefer struct page *page; 2153082d5b6bSGerald Schaefer int rc = 0; 2154dc2628f3SMuchun Song unsigned int order; 2155dc2628f3SMuchun Song struct hstate *h; 2156c8721bbbSNaoya Horiguchi 2157d0177639SLi Zhong if (!hugepages_supported()) 2158082d5b6bSGerald Schaefer return rc; 2159d0177639SLi Zhong 2160dc2628f3SMuchun Song order = huge_page_order(&default_hstate); 2161dc2628f3SMuchun Song for_each_hstate(h) 2162dc2628f3SMuchun Song order = min(order, huge_page_order(h)); 2163dc2628f3SMuchun Song 2164dc2628f3SMuchun Song for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) { 2165eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 2166eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 2167eb03aa00SGerald Schaefer if (rc) 2168082d5b6bSGerald Schaefer break; 2169eb03aa00SGerald Schaefer } 2170082d5b6bSGerald Schaefer 2171082d5b6bSGerald Schaefer return rc; 2172c8721bbbSNaoya Horiguchi } 2173c8721bbbSNaoya Horiguchi 2174ab5ac90aSMichal Hocko /* 2175ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 2176ab5ac90aSMichal Hocko */ 21770c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 2178b65a4edaSMike Kravetz int nid, nodemask_t *nmask, bool zero_ref) 21797893d1d5SAdam Litke { 21809980d744SMichal Hocko struct page *page = NULL; 2181b65a4edaSMike Kravetz bool retry = false; 21827893d1d5SAdam Litke 2183bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2184aa888a74SAndi Kleen return NULL; 2185aa888a74SAndi Kleen 2186db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 21879980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 21889980d744SMichal Hocko goto out_unlock; 2189db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2190d1c3fb1fSNishanth Aravamudan 2191b65a4edaSMike Kravetz retry: 2192f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 21939980d744SMichal Hocko if (!page) 21940c397daeSMichal Hocko return NULL; 2195d1c3fb1fSNishanth Aravamudan 2196db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 21979980d744SMichal Hocko /* 21989980d744SMichal Hocko * We could have raced with the pool size change. 21999980d744SMichal Hocko * Double check that and simply deallocate the new page 22009980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 22019980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 22029980d744SMichal Hocko * codeflow 22039980d744SMichal Hocko */ 22049980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 22059157c311SMike Kravetz SetHPageTemporary(page); 2206db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22079980d744SMichal Hocko put_page(page); 22082bf753e6SKai Shen return NULL; 2209b65a4edaSMike Kravetz } 2210b65a4edaSMike Kravetz 2211b65a4edaSMike Kravetz if (zero_ref) { 2212b65a4edaSMike Kravetz /* 2213b65a4edaSMike Kravetz * Caller requires a page with zero ref count. 2214b65a4edaSMike Kravetz * We will drop ref count here. If someone else is holding 2215b65a4edaSMike Kravetz * a ref, the page will be freed when they drop it. Abuse 2216b65a4edaSMike Kravetz * temporary page flag to accomplish this. 2217b65a4edaSMike Kravetz */ 2218b65a4edaSMike Kravetz SetHPageTemporary(page); 2219b65a4edaSMike Kravetz if (!put_page_testzero(page)) { 2220b65a4edaSMike Kravetz /* 2221b65a4edaSMike Kravetz * Unexpected inflated ref count on freshly allocated 2222b65a4edaSMike Kravetz * huge. Retry once. 2223b65a4edaSMike Kravetz */ 2224b65a4edaSMike Kravetz pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n"); 2225b65a4edaSMike Kravetz spin_unlock_irq(&hugetlb_lock); 2226b65a4edaSMike Kravetz if (retry) 2227b65a4edaSMike Kravetz return NULL; 2228b65a4edaSMike Kravetz 2229b65a4edaSMike Kravetz retry = true; 2230b65a4edaSMike Kravetz goto retry; 2231b65a4edaSMike Kravetz } 2232b65a4edaSMike Kravetz ClearHPageTemporary(page); 2233b65a4edaSMike Kravetz } 2234b65a4edaSMike Kravetz 22359980d744SMichal Hocko h->surplus_huge_pages++; 22364704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 22379980d744SMichal Hocko 22389980d744SMichal Hocko out_unlock: 2239db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22407893d1d5SAdam Litke 22417893d1d5SAdam Litke return page; 22427893d1d5SAdam Litke } 22437893d1d5SAdam Litke 2244bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 2245ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 2246ab5ac90aSMichal Hocko { 2247ab5ac90aSMichal Hocko struct page *page; 2248ab5ac90aSMichal Hocko 2249ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 2250ab5ac90aSMichal Hocko return NULL; 2251ab5ac90aSMichal Hocko 2252f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 2253ab5ac90aSMichal Hocko if (!page) 2254ab5ac90aSMichal Hocko return NULL; 2255ab5ac90aSMichal Hocko 2256ab5ac90aSMichal Hocko /* 2257ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 2258ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 2259ab5ac90aSMichal Hocko */ 22609157c311SMike Kravetz SetHPageTemporary(page); 2261ab5ac90aSMichal Hocko 2262ab5ac90aSMichal Hocko return page; 2263ab5ac90aSMichal Hocko } 2264ab5ac90aSMichal Hocko 2265e4e574b7SAdam Litke /* 2266099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 2267099730d6SDave Hansen */ 2268e0ec90eeSDave Hansen static 22690c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 2270099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 2271099730d6SDave Hansen { 2272cfcaa66fSBen Widawsky struct page *page = NULL; 2273aaf14e40SMichal Hocko struct mempolicy *mpol; 2274aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 2275aaf14e40SMichal Hocko int nid; 2276aaf14e40SMichal Hocko nodemask_t *nodemask; 2277aaf14e40SMichal Hocko 2278aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 2279cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 2280cfcaa66fSBen Widawsky gfp_t gfp = gfp_mask | __GFP_NOWARN; 2281cfcaa66fSBen Widawsky 2282cfcaa66fSBen Widawsky gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); 2283cfcaa66fSBen Widawsky page = alloc_surplus_huge_page(h, gfp, nid, nodemask, false); 2284cfcaa66fSBen Widawsky 2285cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 2286cfcaa66fSBen Widawsky nodemask = NULL; 2287cfcaa66fSBen Widawsky } 2288cfcaa66fSBen Widawsky 2289cfcaa66fSBen Widawsky if (!page) 2290b65a4edaSMike Kravetz page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask, false); 2291aaf14e40SMichal Hocko mpol_cond_put(mpol); 2292aaf14e40SMichal Hocko return page; 2293099730d6SDave Hansen } 2294099730d6SDave Hansen 2295ab5ac90aSMichal Hocko /* page migration callback function */ 22963e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 2297d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 22984db9b2efSMichal Hocko { 2299db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 23004db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 23013e59fcb0SMichal Hocko struct page *page; 23023e59fcb0SMichal Hocko 23033e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 23043e59fcb0SMichal Hocko if (page) { 2305db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23063e59fcb0SMichal Hocko return page; 23074db9b2efSMichal Hocko } 23084db9b2efSMichal Hocko } 2309db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23104db9b2efSMichal Hocko 23110c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 23124db9b2efSMichal Hocko } 23134db9b2efSMichal Hocko 2314ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2315389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2316389c8178SMichal Hocko unsigned long address) 2317ebd63723SMichal Hocko { 2318ebd63723SMichal Hocko struct mempolicy *mpol; 2319ebd63723SMichal Hocko nodemask_t *nodemask; 2320ebd63723SMichal Hocko struct page *page; 2321ebd63723SMichal Hocko gfp_t gfp_mask; 2322ebd63723SMichal Hocko int node; 2323ebd63723SMichal Hocko 2324ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2325ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2326d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2327ebd63723SMichal Hocko mpol_cond_put(mpol); 2328ebd63723SMichal Hocko 2329ebd63723SMichal Hocko return page; 2330ebd63723SMichal Hocko } 2331ebd63723SMichal Hocko 2332bf50bab2SNaoya Horiguchi /* 233325985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2334e4e574b7SAdam Litke * of size 'delta'. 2335e4e574b7SAdam Litke */ 23360a4f3d1bSLiu Xiang static int gather_surplus_pages(struct hstate *h, long delta) 23371b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2338e4e574b7SAdam Litke { 2339e4e574b7SAdam Litke struct list_head surplus_list; 2340e4e574b7SAdam Litke struct page *page, *tmp; 23410a4f3d1bSLiu Xiang int ret; 23420a4f3d1bSLiu Xiang long i; 23430a4f3d1bSLiu Xiang long needed, allocated; 234428073b02SHillf Danton bool alloc_ok = true; 2345e4e574b7SAdam Litke 23469487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2347a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2348ac09b3a1SAdam Litke if (needed <= 0) { 2349a5516438SAndi Kleen h->resv_huge_pages += delta; 2350e4e574b7SAdam Litke return 0; 2351ac09b3a1SAdam Litke } 2352e4e574b7SAdam Litke 2353e4e574b7SAdam Litke allocated = 0; 2354e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 2355e4e574b7SAdam Litke 2356e4e574b7SAdam Litke ret = -ENOMEM; 2357e4e574b7SAdam Litke retry: 2358db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2359e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 23600c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 2361b65a4edaSMike Kravetz NUMA_NO_NODE, NULL, true); 236228073b02SHillf Danton if (!page) { 236328073b02SHillf Danton alloc_ok = false; 236428073b02SHillf Danton break; 236528073b02SHillf Danton } 2366e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 236769ed779aSDavid Rientjes cond_resched(); 2368e4e574b7SAdam Litke } 236928073b02SHillf Danton allocated += i; 2370e4e574b7SAdam Litke 2371e4e574b7SAdam Litke /* 2372e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2373e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2374e4e574b7SAdam Litke */ 2375db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2376a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2377a5516438SAndi Kleen (h->free_huge_pages + allocated); 237828073b02SHillf Danton if (needed > 0) { 237928073b02SHillf Danton if (alloc_ok) 2380e4e574b7SAdam Litke goto retry; 238128073b02SHillf Danton /* 238228073b02SHillf Danton * We were not able to allocate enough pages to 238328073b02SHillf Danton * satisfy the entire reservation so we free what 238428073b02SHillf Danton * we've allocated so far. 238528073b02SHillf Danton */ 238628073b02SHillf Danton goto free; 238728073b02SHillf Danton } 2388e4e574b7SAdam Litke /* 2389e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 239025985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2391e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2392ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2393ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2394ac09b3a1SAdam Litke * before they are reserved. 2395e4e574b7SAdam Litke */ 2396e4e574b7SAdam Litke needed += allocated; 2397a5516438SAndi Kleen h->resv_huge_pages += delta; 2398e4e574b7SAdam Litke ret = 0; 2399a9869b83SNaoya Horiguchi 240019fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 240119fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 240219fc3f0aSAdam Litke if ((--needed) < 0) 240319fc3f0aSAdam Litke break; 2404b65a4edaSMike Kravetz /* Add the page to the hugetlb allocator */ 2405a5516438SAndi Kleen enqueue_huge_page(h, page); 240619fc3f0aSAdam Litke } 240728073b02SHillf Danton free: 2408db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 240919fc3f0aSAdam Litke 2410b65a4edaSMike Kravetz /* 2411b65a4edaSMike Kravetz * Free unnecessary surplus pages to the buddy allocator. 2412b65a4edaSMike Kravetz * Pages have no ref count, call free_huge_page directly. 2413b65a4edaSMike Kravetz */ 2414c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2415b65a4edaSMike Kravetz free_huge_page(page); 2416db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2417e4e574b7SAdam Litke 2418e4e574b7SAdam Litke return ret; 2419e4e574b7SAdam Litke } 2420e4e574b7SAdam Litke 2421e4e574b7SAdam Litke /* 2422e5bbc8a6SMike Kravetz * This routine has two main purposes: 2423e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2424e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2425e5bbc8a6SMike Kravetz * to the associated reservation map. 2426e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2427e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2428e4e574b7SAdam Litke */ 2429a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2430a5516438SAndi Kleen unsigned long unused_resv_pages) 2431e4e574b7SAdam Litke { 2432e4e574b7SAdam Litke unsigned long nr_pages; 243310c6ec49SMike Kravetz struct page *page; 243410c6ec49SMike Kravetz LIST_HEAD(page_list); 243510c6ec49SMike Kravetz 24369487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 243710c6ec49SMike Kravetz /* Uncommit the reservation */ 243810c6ec49SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2439e4e574b7SAdam Litke 2440c0531714SNaoya Horiguchi if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 2441e5bbc8a6SMike Kravetz goto out; 2442aa888a74SAndi Kleen 2443e5bbc8a6SMike Kravetz /* 2444e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2445e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2446e5bbc8a6SMike Kravetz */ 2447a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2448e4e574b7SAdam Litke 2449685f3457SLee Schermerhorn /* 2450685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 24519b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 24529b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 24539b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 245410c6ec49SMike Kravetz * remove_pool_huge_page() will balance the freed pages across the 24559b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2456685f3457SLee Schermerhorn */ 2457685f3457SLee Schermerhorn while (nr_pages--) { 245810c6ec49SMike Kravetz page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); 245910c6ec49SMike Kravetz if (!page) 2460e5bbc8a6SMike Kravetz goto out; 246110c6ec49SMike Kravetz 246210c6ec49SMike Kravetz list_add(&page->lru, &page_list); 2463e4e574b7SAdam Litke } 2464e5bbc8a6SMike Kravetz 2465e5bbc8a6SMike Kravetz out: 2466db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 246710c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 2468db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2469e4e574b7SAdam Litke } 2470e4e574b7SAdam Litke 24715e911373SMike Kravetz 2472c37f9fb1SAndy Whitcroft /* 2473feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 24745e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2475cf3ad20bSMike Kravetz * 2476cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2477cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2478cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2479cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2480cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2481feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2482feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2483feba16e2SMike Kravetz * is called in such cases. 2484cf3ad20bSMike Kravetz * 2485cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2486cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2487cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2488cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2489cf3ad20bSMike Kravetz * take appropriate action. 249096b96a96SMike Kravetz * 249196b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 249296b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 249396b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 249496b96a96SMike Kravetz * reservation exists. 2495846be085SMike Kravetz * 2496846be085SMike Kravetz * vma_del_reservation is used in error paths where an entry in the reserve 2497846be085SMike Kravetz * map was created during huge page allocation and must be removed. It is to 2498846be085SMike Kravetz * be called after calling vma_needs_reservation to determine if a reservation 2499846be085SMike Kravetz * exists. 2500c37f9fb1SAndy Whitcroft */ 25015e911373SMike Kravetz enum vma_resv_mode { 25025e911373SMike Kravetz VMA_NEEDS_RESV, 25035e911373SMike Kravetz VMA_COMMIT_RESV, 2504feba16e2SMike Kravetz VMA_END_RESV, 250596b96a96SMike Kravetz VMA_ADD_RESV, 2506846be085SMike Kravetz VMA_DEL_RESV, 25075e911373SMike Kravetz }; 2508cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2509cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 25105e911373SMike Kravetz enum vma_resv_mode mode) 2511c37f9fb1SAndy Whitcroft { 25124e35f483SJoonsoo Kim struct resv_map *resv; 25134e35f483SJoonsoo Kim pgoff_t idx; 2514cf3ad20bSMike Kravetz long ret; 25150db9d74eSMina Almasry long dummy_out_regions_needed; 2516c37f9fb1SAndy Whitcroft 25174e35f483SJoonsoo Kim resv = vma_resv_map(vma); 25184e35f483SJoonsoo Kim if (!resv) 2519c37f9fb1SAndy Whitcroft return 1; 2520c37f9fb1SAndy Whitcroft 25214e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 25225e911373SMike Kravetz switch (mode) { 25235e911373SMike Kravetz case VMA_NEEDS_RESV: 25240db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 25250db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 25260db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 25270db9d74eSMina Almasry * ever require 1 region. 25280db9d74eSMina Almasry */ 25290db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 25305e911373SMike Kravetz break; 25315e911373SMike Kravetz case VMA_COMMIT_RESV: 2532075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25330db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25340db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25355e911373SMike Kravetz break; 2536feba16e2SMike Kravetz case VMA_END_RESV: 25370db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 25385e911373SMike Kravetz ret = 0; 25395e911373SMike Kravetz break; 254096b96a96SMike Kravetz case VMA_ADD_RESV: 25410db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2542075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25430db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25440db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25450db9d74eSMina Almasry } else { 25460db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 254796b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 254896b96a96SMike Kravetz } 254996b96a96SMike Kravetz break; 2550846be085SMike Kravetz case VMA_DEL_RESV: 2551846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 2552846be085SMike Kravetz region_abort(resv, idx, idx + 1, 1); 2553846be085SMike Kravetz ret = region_del(resv, idx, idx + 1); 2554846be085SMike Kravetz } else { 2555846be085SMike Kravetz ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 2556846be085SMike Kravetz /* region_add calls of range 1 should never fail. */ 2557846be085SMike Kravetz VM_BUG_ON(ret < 0); 2558846be085SMike Kravetz } 2559846be085SMike Kravetz break; 25605e911373SMike Kravetz default: 25615e911373SMike Kravetz BUG(); 25625e911373SMike Kravetz } 256384afd99bSAndy Whitcroft 2564846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV) 2565cf3ad20bSMike Kravetz return ret; 256667961f9dSMike Kravetz /* 2567bf3d12b9SMiaohe Lin * We know private mapping must have HPAGE_RESV_OWNER set. 2568bf3d12b9SMiaohe Lin * 256967961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 257067961f9dSMike Kravetz * However, a file associated with mapping could have been 257167961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 257267961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 257367961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 257467961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 257567961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 257667961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 257767961f9dSMike Kravetz * reservation has already been consumed. As a result, the 257867961f9dSMike Kravetz * return value of this routine is the opposite of the 257967961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 258067961f9dSMike Kravetz */ 2581bf3d12b9SMiaohe Lin if (ret > 0) 258267961f9dSMike Kravetz return 0; 2583bf3d12b9SMiaohe Lin if (ret == 0) 258467961f9dSMike Kravetz return 1; 2585bf3d12b9SMiaohe Lin return ret; 258684afd99bSAndy Whitcroft } 2587cf3ad20bSMike Kravetz 2588cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2589a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2590c37f9fb1SAndy Whitcroft { 25915e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2592cf3ad20bSMike Kravetz } 2593c37f9fb1SAndy Whitcroft 2594cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2595cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2596cf3ad20bSMike Kravetz { 25975e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 25985e911373SMike Kravetz } 25995e911373SMike Kravetz 2600feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 26015e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 26025e911373SMike Kravetz { 2603feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2604c37f9fb1SAndy Whitcroft } 2605c37f9fb1SAndy Whitcroft 260696b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 260796b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 260896b96a96SMike Kravetz { 260996b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 261096b96a96SMike Kravetz } 261196b96a96SMike Kravetz 2612846be085SMike Kravetz static long vma_del_reservation(struct hstate *h, 2613846be085SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 261496b96a96SMike Kravetz { 2615846be085SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV); 2616846be085SMike Kravetz } 2617846be085SMike Kravetz 2618846be085SMike Kravetz /* 2619846be085SMike Kravetz * This routine is called to restore reservation information on error paths. 2620846be085SMike Kravetz * It should ONLY be called for pages allocated via alloc_huge_page(), and 2621846be085SMike Kravetz * the hugetlb mutex should remain held when calling this routine. 2622846be085SMike Kravetz * 2623846be085SMike Kravetz * It handles two specific cases: 2624846be085SMike Kravetz * 1) A reservation was in place and the page consumed the reservation. 2625846be085SMike Kravetz * HPageRestoreReserve is set in the page. 2626846be085SMike Kravetz * 2) No reservation was in place for the page, so HPageRestoreReserve is 2627846be085SMike Kravetz * not set. However, alloc_huge_page always updates the reserve map. 2628846be085SMike Kravetz * 2629846be085SMike Kravetz * In case 1, free_huge_page later in the error path will increment the 2630846be085SMike Kravetz * global reserve count. But, free_huge_page does not have enough context 2631846be085SMike Kravetz * to adjust the reservation map. This case deals primarily with private 2632846be085SMike Kravetz * mappings. Adjust the reserve map here to be consistent with global 2633846be085SMike Kravetz * reserve count adjustments to be made by free_huge_page. Make sure the 2634846be085SMike Kravetz * reserve map indicates there is a reservation present. 2635846be085SMike Kravetz * 2636846be085SMike Kravetz * In case 2, simply undo reserve map modifications done by alloc_huge_page. 2637846be085SMike Kravetz */ 2638846be085SMike Kravetz void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, 2639846be085SMike Kravetz unsigned long address, struct page *page) 2640846be085SMike Kravetz { 264196b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 264296b96a96SMike Kravetz 2643846be085SMike Kravetz if (HPageRestoreReserve(page)) { 2644846be085SMike Kravetz if (unlikely(rc < 0)) 264596b96a96SMike Kravetz /* 264696b96a96SMike Kravetz * Rare out of memory condition in reserve map 2647d6995da3SMike Kravetz * manipulation. Clear HPageRestoreReserve so that 264896b96a96SMike Kravetz * global reserve count will not be incremented 264996b96a96SMike Kravetz * by free_huge_page. This will make it appear 265096b96a96SMike Kravetz * as though the reservation for this page was 265196b96a96SMike Kravetz * consumed. This may prevent the task from 265296b96a96SMike Kravetz * faulting in the page at a later time. This 265396b96a96SMike Kravetz * is better than inconsistent global huge page 265496b96a96SMike Kravetz * accounting of reserve counts. 265596b96a96SMike Kravetz */ 2656d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 2657846be085SMike Kravetz else if (rc) 2658846be085SMike Kravetz (void)vma_add_reservation(h, vma, address); 2659846be085SMike Kravetz else 2660846be085SMike Kravetz vma_end_reservation(h, vma, address); 2661846be085SMike Kravetz } else { 2662846be085SMike Kravetz if (!rc) { 266396b96a96SMike Kravetz /* 2664846be085SMike Kravetz * This indicates there is an entry in the reserve map 2665c7b1850dSMike Kravetz * not added by alloc_huge_page. We know it was added 2666846be085SMike Kravetz * before the alloc_huge_page call, otherwise 2667846be085SMike Kravetz * HPageRestoreReserve would be set on the page. 2668846be085SMike Kravetz * Remove the entry so that a subsequent allocation 2669846be085SMike Kravetz * does not consume a reservation. 267096b96a96SMike Kravetz */ 2671846be085SMike Kravetz rc = vma_del_reservation(h, vma, address); 2672846be085SMike Kravetz if (rc < 0) 2673846be085SMike Kravetz /* 2674846be085SMike Kravetz * VERY rare out of memory condition. Since 2675846be085SMike Kravetz * we can not delete the entry, set 2676846be085SMike Kravetz * HPageRestoreReserve so that the reserve 2677846be085SMike Kravetz * count will be incremented when the page 2678846be085SMike Kravetz * is freed. This reserve will be consumed 2679846be085SMike Kravetz * on a subsequent allocation. 2680846be085SMike Kravetz */ 2681846be085SMike Kravetz SetHPageRestoreReserve(page); 2682846be085SMike Kravetz } else if (rc < 0) { 2683846be085SMike Kravetz /* 2684846be085SMike Kravetz * Rare out of memory condition from 2685846be085SMike Kravetz * vma_needs_reservation call. Memory allocation is 2686846be085SMike Kravetz * only attempted if a new entry is needed. Therefore, 2687846be085SMike Kravetz * this implies there is not an entry in the 2688846be085SMike Kravetz * reserve map. 2689846be085SMike Kravetz * 2690846be085SMike Kravetz * For shared mappings, no entry in the map indicates 2691846be085SMike Kravetz * no reservation. We are done. 2692846be085SMike Kravetz */ 2693846be085SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 2694846be085SMike Kravetz /* 2695846be085SMike Kravetz * For private mappings, no entry indicates 2696846be085SMike Kravetz * a reservation is present. Since we can 2697846be085SMike Kravetz * not add an entry, set SetHPageRestoreReserve 2698846be085SMike Kravetz * on the page so reserve count will be 2699846be085SMike Kravetz * incremented when freed. This reserve will 2700846be085SMike Kravetz * be consumed on a subsequent allocation. 2701846be085SMike Kravetz */ 2702846be085SMike Kravetz SetHPageRestoreReserve(page); 270396b96a96SMike Kravetz } else 2704846be085SMike Kravetz /* 2705846be085SMike Kravetz * No reservation present, do nothing 2706846be085SMike Kravetz */ 270796b96a96SMike Kravetz vma_end_reservation(h, vma, address); 270896b96a96SMike Kravetz } 270996b96a96SMike Kravetz } 271096b96a96SMike Kravetz 2711369fa227SOscar Salvador /* 2712369fa227SOscar Salvador * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one 2713369fa227SOscar Salvador * @h: struct hstate old page belongs to 2714369fa227SOscar Salvador * @old_page: Old page to dissolve 2715ae37c7ffSOscar Salvador * @list: List to isolate the page in case we need to 2716369fa227SOscar Salvador * Returns 0 on success, otherwise negated error. 2717369fa227SOscar Salvador */ 2718ae37c7ffSOscar Salvador static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, 2719ae37c7ffSOscar Salvador struct list_head *list) 2720369fa227SOscar Salvador { 2721369fa227SOscar Salvador gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2722369fa227SOscar Salvador int nid = page_to_nid(old_page); 2723b65a4edaSMike Kravetz bool alloc_retry = false; 2724369fa227SOscar Salvador struct page *new_page; 2725369fa227SOscar Salvador int ret = 0; 2726369fa227SOscar Salvador 2727369fa227SOscar Salvador /* 2728369fa227SOscar Salvador * Before dissolving the page, we need to allocate a new one for the 2729f41f2ed4SMuchun Song * pool to remain stable. Here, we allocate the page and 'prep' it 2730f41f2ed4SMuchun Song * by doing everything but actually updating counters and adding to 2731f41f2ed4SMuchun Song * the pool. This simplifies and let us do most of the processing 2732f41f2ed4SMuchun Song * under the lock. 2733369fa227SOscar Salvador */ 2734b65a4edaSMike Kravetz alloc_retry: 2735369fa227SOscar Salvador new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL); 2736369fa227SOscar Salvador if (!new_page) 2737369fa227SOscar Salvador return -ENOMEM; 2738b65a4edaSMike Kravetz /* 2739b65a4edaSMike Kravetz * If all goes well, this page will be directly added to the free 2740b65a4edaSMike Kravetz * list in the pool. For this the ref count needs to be zero. 2741b65a4edaSMike Kravetz * Attempt to drop now, and retry once if needed. It is VERY 2742b65a4edaSMike Kravetz * unlikely there is another ref on the page. 2743b65a4edaSMike Kravetz * 2744b65a4edaSMike Kravetz * If someone else has a reference to the page, it will be freed 2745b65a4edaSMike Kravetz * when they drop their ref. Abuse temporary page flag to accomplish 2746b65a4edaSMike Kravetz * this. Retry once if there is an inflated ref count. 2747b65a4edaSMike Kravetz */ 2748b65a4edaSMike Kravetz SetHPageTemporary(new_page); 2749b65a4edaSMike Kravetz if (!put_page_testzero(new_page)) { 2750b65a4edaSMike Kravetz if (alloc_retry) 2751b65a4edaSMike Kravetz return -EBUSY; 2752b65a4edaSMike Kravetz 2753b65a4edaSMike Kravetz alloc_retry = true; 2754b65a4edaSMike Kravetz goto alloc_retry; 2755b65a4edaSMike Kravetz } 2756b65a4edaSMike Kravetz ClearHPageTemporary(new_page); 2757b65a4edaSMike Kravetz 2758f41f2ed4SMuchun Song __prep_new_huge_page(h, new_page); 2759369fa227SOscar Salvador 2760369fa227SOscar Salvador retry: 2761369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2762369fa227SOscar Salvador if (!PageHuge(old_page)) { 2763369fa227SOscar Salvador /* 2764369fa227SOscar Salvador * Freed from under us. Drop new_page too. 2765369fa227SOscar Salvador */ 2766369fa227SOscar Salvador goto free_new; 2767369fa227SOscar Salvador } else if (page_count(old_page)) { 2768369fa227SOscar Salvador /* 2769ae37c7ffSOscar Salvador * Someone has grabbed the page, try to isolate it here. 2770ae37c7ffSOscar Salvador * Fail with -EBUSY if not possible. 2771369fa227SOscar Salvador */ 2772ae37c7ffSOscar Salvador spin_unlock_irq(&hugetlb_lock); 27737ce82f4cSMiaohe Lin ret = isolate_hugetlb(old_page, list); 2774ae37c7ffSOscar Salvador spin_lock_irq(&hugetlb_lock); 2775369fa227SOscar Salvador goto free_new; 2776369fa227SOscar Salvador } else if (!HPageFreed(old_page)) { 2777369fa227SOscar Salvador /* 2778369fa227SOscar Salvador * Page's refcount is 0 but it has not been enqueued in the 2779369fa227SOscar Salvador * freelist yet. Race window is small, so we can succeed here if 2780369fa227SOscar Salvador * we retry. 2781369fa227SOscar Salvador */ 2782369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2783369fa227SOscar Salvador cond_resched(); 2784369fa227SOscar Salvador goto retry; 2785369fa227SOscar Salvador } else { 2786369fa227SOscar Salvador /* 2787369fa227SOscar Salvador * Ok, old_page is still a genuine free hugepage. Remove it from 2788369fa227SOscar Salvador * the freelist and decrease the counters. These will be 2789369fa227SOscar Salvador * incremented again when calling __prep_account_new_huge_page() 2790369fa227SOscar Salvador * and enqueue_huge_page() for new_page. The counters will remain 2791369fa227SOscar Salvador * stable since this happens under the lock. 2792369fa227SOscar Salvador */ 2793369fa227SOscar Salvador remove_hugetlb_page(h, old_page, false); 2794369fa227SOscar Salvador 2795369fa227SOscar Salvador /* 2796b65a4edaSMike Kravetz * Ref count on new page is already zero as it was dropped 2797b65a4edaSMike Kravetz * earlier. It can be directly added to the pool free list. 2798369fa227SOscar Salvador */ 2799369fa227SOscar Salvador __prep_account_new_huge_page(h, nid); 2800369fa227SOscar Salvador enqueue_huge_page(h, new_page); 2801369fa227SOscar Salvador 2802369fa227SOscar Salvador /* 2803369fa227SOscar Salvador * Pages have been replaced, we can safely free the old one. 2804369fa227SOscar Salvador */ 2805369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2806b65d4adbSMuchun Song update_and_free_page(h, old_page, false); 2807369fa227SOscar Salvador } 2808369fa227SOscar Salvador 2809369fa227SOscar Salvador return ret; 2810369fa227SOscar Salvador 2811369fa227SOscar Salvador free_new: 2812369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2813b65a4edaSMike Kravetz /* Page has a zero ref count, but needs a ref to be freed */ 2814b65a4edaSMike Kravetz set_page_refcounted(new_page); 2815b65d4adbSMuchun Song update_and_free_page(h, new_page, false); 2816369fa227SOscar Salvador 2817369fa227SOscar Salvador return ret; 2818369fa227SOscar Salvador } 2819369fa227SOscar Salvador 2820ae37c7ffSOscar Salvador int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list) 2821369fa227SOscar Salvador { 2822369fa227SOscar Salvador struct hstate *h; 2823369fa227SOscar Salvador struct page *head; 2824ae37c7ffSOscar Salvador int ret = -EBUSY; 2825369fa227SOscar Salvador 2826369fa227SOscar Salvador /* 2827369fa227SOscar Salvador * The page might have been dissolved from under our feet, so make sure 2828369fa227SOscar Salvador * to carefully check the state under the lock. 2829369fa227SOscar Salvador * Return success when racing as if we dissolved the page ourselves. 2830369fa227SOscar Salvador */ 2831369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2832369fa227SOscar Salvador if (PageHuge(page)) { 2833369fa227SOscar Salvador head = compound_head(page); 2834369fa227SOscar Salvador h = page_hstate(head); 2835369fa227SOscar Salvador } else { 2836369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2837369fa227SOscar Salvador return 0; 2838369fa227SOscar Salvador } 2839369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2840369fa227SOscar Salvador 2841369fa227SOscar Salvador /* 2842369fa227SOscar Salvador * Fence off gigantic pages as there is a cyclic dependency between 2843369fa227SOscar Salvador * alloc_contig_range and them. Return -ENOMEM as this has the effect 2844369fa227SOscar Salvador * of bailing out right away without further retrying. 2845369fa227SOscar Salvador */ 2846369fa227SOscar Salvador if (hstate_is_gigantic(h)) 2847369fa227SOscar Salvador return -ENOMEM; 2848369fa227SOscar Salvador 28497ce82f4cSMiaohe Lin if (page_count(head) && !isolate_hugetlb(head, list)) 2850ae37c7ffSOscar Salvador ret = 0; 2851ae37c7ffSOscar Salvador else if (!page_count(head)) 2852ae37c7ffSOscar Salvador ret = alloc_and_dissolve_huge_page(h, head, list); 2853ae37c7ffSOscar Salvador 2854ae37c7ffSOscar Salvador return ret; 2855369fa227SOscar Salvador } 2856369fa227SOscar Salvador 285770c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 285804f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2859348ea204SAdam Litke { 286090481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2861a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2862348ea204SAdam Litke struct page *page; 2863d85f69b0SMike Kravetz long map_chg, map_commit; 2864d85f69b0SMike Kravetz long gbl_chg; 28656d76dcf4SAneesh Kumar K.V int ret, idx; 28666d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 286708cf9fafSMina Almasry bool deferred_reserve; 28682fc39cecSAdam Litke 28696d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2870a1e78772SMel Gorman /* 2871d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2872d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2873d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2874a1e78772SMel Gorman */ 2875d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2876d85f69b0SMike Kravetz if (map_chg < 0) 287776dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2878d85f69b0SMike Kravetz 2879d85f69b0SMike Kravetz /* 2880d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2881d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2882d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2883d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2884d85f69b0SMike Kravetz * checked against any subpool limit. 2885d85f69b0SMike Kravetz */ 2886d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2887d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2888d85f69b0SMike Kravetz if (gbl_chg < 0) { 2889feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 289076dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 28915e911373SMike Kravetz } 289290d8b7e6SAdam Litke 2893d85f69b0SMike Kravetz /* 2894d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2895d85f69b0SMike Kravetz * map, there could be reservations associated with the 2896d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2897d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2898d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2899d85f69b0SMike Kravetz * the subpool reservations. 2900d85f69b0SMike Kravetz */ 2901d85f69b0SMike Kravetz if (avoid_reserve) 2902d85f69b0SMike Kravetz gbl_chg = 1; 2903d85f69b0SMike Kravetz } 2904d85f69b0SMike Kravetz 290508cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 290608cf9fafSMina Almasry */ 29076501fe5fSMiaohe Lin deferred_reserve = map_chg || avoid_reserve; 290808cf9fafSMina Almasry if (deferred_reserve) { 290908cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 291008cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 29118f34af6fSJianyu Zhan if (ret) 29128f34af6fSJianyu Zhan goto out_subpool_put; 291308cf9fafSMina Almasry } 291408cf9fafSMina Almasry 291508cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 291608cf9fafSMina Almasry if (ret) 291708cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 29188f34af6fSJianyu Zhan 2919db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2920d85f69b0SMike Kravetz /* 2921d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2922d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2923d85f69b0SMike Kravetz * a reservation exists for the allocation. 2924d85f69b0SMike Kravetz */ 2925d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 292681a6fcaeSJoonsoo Kim if (!page) { 2927db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 29280c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 29298f34af6fSJianyu Zhan if (!page) 29308f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2931a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2932d6995da3SMike Kravetz SetHPageRestoreReserve(page); 2933a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2934a88c7695SNaoya Horiguchi } 2935db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 293615a8d68eSWei Yang list_add(&page->lru, &h->hugepage_activelist); 293781a6fcaeSJoonsoo Kim /* Fall through */ 2938a1e78772SMel Gorman } 293981a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 294008cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 294108cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 294208cf9fafSMina Almasry */ 294308cf9fafSMina Almasry if (deferred_reserve) { 294408cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 294508cf9fafSMina Almasry h_cg, page); 294608cf9fafSMina Almasry } 294708cf9fafSMina Almasry 2948db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2949a1e78772SMel Gorman 2950d6995da3SMike Kravetz hugetlb_set_page_subpool(page, spool); 2951a1e78772SMel Gorman 2952d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2953d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 295433039678SMike Kravetz /* 295533039678SMike Kravetz * The page was added to the reservation map between 295633039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 295733039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 295833039678SMike Kravetz * Adjust for the subpool count incremented above AND 295933039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 296033039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 296133039678SMike Kravetz * no longer applies. 296233039678SMike Kravetz */ 296333039678SMike Kravetz long rsv_adjust; 296433039678SMike Kravetz 296533039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 296633039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 296779aa925bSMike Kravetz if (deferred_reserve) 296879aa925bSMike Kravetz hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 296979aa925bSMike Kravetz pages_per_huge_page(h), page); 297033039678SMike Kravetz } 29717893d1d5SAdam Litke return page; 29728f34af6fSJianyu Zhan 29738f34af6fSJianyu Zhan out_uncharge_cgroup: 29748f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 297508cf9fafSMina Almasry out_uncharge_cgroup_reservation: 297608cf9fafSMina Almasry if (deferred_reserve) 297708cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 297808cf9fafSMina Almasry h_cg); 29798f34af6fSJianyu Zhan out_subpool_put: 2980d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 29818f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2982feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 29838f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2984b45b5bd6SDavid Gibson } 2985b45b5bd6SDavid Gibson 2986b5389086SZhenguo Yao int alloc_bootmem_huge_page(struct hstate *h, int nid) 2987e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2988b5389086SZhenguo Yao int __alloc_bootmem_huge_page(struct hstate *h, int nid) 2989aa888a74SAndi Kleen { 2990b5389086SZhenguo Yao struct huge_bootmem_page *m = NULL; /* initialize for clang */ 2991b2261026SJoonsoo Kim int nr_nodes, node; 2992aa888a74SAndi Kleen 2993b5389086SZhenguo Yao /* do node specific alloc */ 2994b5389086SZhenguo Yao if (nid != NUMA_NO_NODE) { 2995b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), 2996b5389086SZhenguo Yao 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid); 2997b5389086SZhenguo Yao if (!m) 2998b5389086SZhenguo Yao return 0; 2999b5389086SZhenguo Yao goto found; 3000b5389086SZhenguo Yao } 3001b5389086SZhenguo Yao /* allocate from next node when distributing huge pages */ 3002b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 3003b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw( 30048b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 300597ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 3006aa888a74SAndi Kleen /* 3007aa888a74SAndi Kleen * Use the beginning of the huge page to store the 3008aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 3009aa888a74SAndi Kleen * puts them into the mem_map). 3010aa888a74SAndi Kleen */ 3011b5389086SZhenguo Yao if (!m) 3012b5389086SZhenguo Yao return 0; 3013aa888a74SAndi Kleen goto found; 3014aa888a74SAndi Kleen } 3015aa888a74SAndi Kleen 3016aa888a74SAndi Kleen found: 3017aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 3018330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 3019aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 3020aa888a74SAndi Kleen m->hstate = h; 3021aa888a74SAndi Kleen return 1; 3022aa888a74SAndi Kleen } 3023aa888a74SAndi Kleen 302448b8d744SMike Kravetz /* 302548b8d744SMike Kravetz * Put bootmem huge pages into the standard lists after mem_map is up. 302648b8d744SMike Kravetz * Note: This only applies to gigantic (order > MAX_ORDER) pages. 302748b8d744SMike Kravetz */ 3028aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 3029aa888a74SAndi Kleen { 3030aa888a74SAndi Kleen struct huge_bootmem_page *m; 3031aa888a74SAndi Kleen 3032aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 303340d18ebfSMike Kravetz struct page *page = virt_to_page(m); 3034aa888a74SAndi Kleen struct hstate *h = m->hstate; 3035ee8f248dSBecky Bruce 303648b8d744SMike Kravetz VM_BUG_ON(!hstate_is_gigantic(h)); 3037aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 30387118fc29SMike Kravetz if (prep_compound_gigantic_page(page, huge_page_order(h))) { 3039ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 3040aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 30417118fc29SMike Kravetz put_page(page); /* add to the hugepage allocator */ 30427118fc29SMike Kravetz } else { 3043416d85edSMike Kravetz /* VERY unlikely inflated ref count on a tail page */ 30447118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 30457118fc29SMike Kravetz } 3046af0fb9dfSMichal Hocko 3047b0320c7bSRafael Aquini /* 304848b8d744SMike Kravetz * We need to restore the 'stolen' pages to totalram_pages 304948b8d744SMike Kravetz * in order to fix confusing memory reports from free(1) and 305048b8d744SMike Kravetz * other side-effects, like CommitLimit going negative. 3051b0320c7bSRafael Aquini */ 3052c78a7f36SMiaohe Lin adjust_managed_page_count(page, pages_per_huge_page(h)); 3053520495feSCannon Matthews cond_resched(); 3054aa888a74SAndi Kleen } 3055aa888a74SAndi Kleen } 3056b5389086SZhenguo Yao static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid) 3057b5389086SZhenguo Yao { 3058b5389086SZhenguo Yao unsigned long i; 3059b5389086SZhenguo Yao char buf[32]; 3060b5389086SZhenguo Yao 3061b5389086SZhenguo Yao for (i = 0; i < h->max_huge_pages_node[nid]; ++i) { 3062b5389086SZhenguo Yao if (hstate_is_gigantic(h)) { 3063b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, nid)) 3064b5389086SZhenguo Yao break; 3065b5389086SZhenguo Yao } else { 3066b5389086SZhenguo Yao struct page *page; 3067b5389086SZhenguo Yao gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 3068b5389086SZhenguo Yao 3069b5389086SZhenguo Yao page = alloc_fresh_huge_page(h, gfp_mask, nid, 3070b5389086SZhenguo Yao &node_states[N_MEMORY], NULL); 3071b5389086SZhenguo Yao if (!page) 3072b5389086SZhenguo Yao break; 3073b5389086SZhenguo Yao put_page(page); /* free it into the hugepage allocator */ 3074b5389086SZhenguo Yao } 3075b5389086SZhenguo Yao cond_resched(); 3076b5389086SZhenguo Yao } 3077b5389086SZhenguo Yao if (i == h->max_huge_pages_node[nid]) 3078b5389086SZhenguo Yao return; 3079b5389086SZhenguo Yao 3080b5389086SZhenguo Yao string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3081b5389086SZhenguo Yao pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n", 3082b5389086SZhenguo Yao h->max_huge_pages_node[nid], buf, nid, i); 3083b5389086SZhenguo Yao h->max_huge_pages -= (h->max_huge_pages_node[nid] - i); 3084b5389086SZhenguo Yao h->max_huge_pages_node[nid] = i; 3085b5389086SZhenguo Yao } 3086aa888a74SAndi Kleen 30878faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 30881da177e4SLinus Torvalds { 30891da177e4SLinus Torvalds unsigned long i; 3090f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 3091b5389086SZhenguo Yao bool node_specific_alloc = false; 3092f60858f9SMike Kravetz 3093b5389086SZhenguo Yao /* skip gigantic hugepages allocation if hugetlb_cma enabled */ 3094b5389086SZhenguo Yao if (hstate_is_gigantic(h) && hugetlb_cma_size) { 3095b5389086SZhenguo Yao pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 3096b5389086SZhenguo Yao return; 3097b5389086SZhenguo Yao } 3098b5389086SZhenguo Yao 3099b5389086SZhenguo Yao /* do node specific alloc */ 31000a7a0f6fSPeng Liu for_each_online_node(i) { 3101b5389086SZhenguo Yao if (h->max_huge_pages_node[i] > 0) { 3102b5389086SZhenguo Yao hugetlb_hstate_alloc_pages_onenode(h, i); 3103b5389086SZhenguo Yao node_specific_alloc = true; 3104b5389086SZhenguo Yao } 3105b5389086SZhenguo Yao } 3106b5389086SZhenguo Yao 3107b5389086SZhenguo Yao if (node_specific_alloc) 3108b5389086SZhenguo Yao return; 3109b5389086SZhenguo Yao 3110b5389086SZhenguo Yao /* below will do all node balanced alloc */ 3111f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 3112f60858f9SMike Kravetz /* 3113f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3114f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 3115f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 3116f60858f9SMike Kravetz * time, we are likely in bigger trouble. 3117f60858f9SMike Kravetz */ 3118f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 3119f60858f9SMike Kravetz GFP_KERNEL); 3120f60858f9SMike Kravetz } else { 3121f60858f9SMike Kravetz /* allocations done at boot time */ 3122f60858f9SMike Kravetz node_alloc_noretry = NULL; 3123f60858f9SMike Kravetz } 3124f60858f9SMike Kravetz 3125f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 3126f60858f9SMike Kravetz if (node_alloc_noretry) 3127f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 31281da177e4SLinus Torvalds 3129e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 3130bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 3131b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, NUMA_NO_NODE)) 3132aa888a74SAndi Kleen break; 31330c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 3134f60858f9SMike Kravetz &node_states[N_MEMORY], 3135f60858f9SMike Kravetz node_alloc_noretry)) 31361da177e4SLinus Torvalds break; 313769ed779aSDavid Rientjes cond_resched(); 31381da177e4SLinus Torvalds } 3139d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 3140d715cf80SLiam R. Howlett char buf[32]; 3141d715cf80SLiam R. Howlett 3142c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3143d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 3144d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 31458faa8b07SAndi Kleen h->max_huge_pages = i; 3146e5ff2159SAndi Kleen } 3147f60858f9SMike Kravetz kfree(node_alloc_noretry); 3148d715cf80SLiam R. Howlett } 3149e5ff2159SAndi Kleen 3150e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 3151e5ff2159SAndi Kleen { 315279dfc695SMike Kravetz struct hstate *h, *h2; 3153e5ff2159SAndi Kleen 3154e5ff2159SAndi Kleen for_each_hstate(h) { 31558faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 3156bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 31578faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 315879dfc695SMike Kravetz 315979dfc695SMike Kravetz /* 316079dfc695SMike Kravetz * Set demote order for each hstate. Note that 316179dfc695SMike Kravetz * h->demote_order is initially 0. 316279dfc695SMike Kravetz * - We can not demote gigantic pages if runtime freeing 316379dfc695SMike Kravetz * is not supported, so skip this. 3164a01f4390SMike Kravetz * - If CMA allocation is possible, we can not demote 3165a01f4390SMike Kravetz * HUGETLB_PAGE_ORDER or smaller size pages. 316679dfc695SMike Kravetz */ 316779dfc695SMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 316879dfc695SMike Kravetz continue; 3169a01f4390SMike Kravetz if (hugetlb_cma_size && h->order <= HUGETLB_PAGE_ORDER) 3170a01f4390SMike Kravetz continue; 317179dfc695SMike Kravetz for_each_hstate(h2) { 317279dfc695SMike Kravetz if (h2 == h) 317379dfc695SMike Kravetz continue; 317479dfc695SMike Kravetz if (h2->order < h->order && 317579dfc695SMike Kravetz h2->order > h->demote_order) 317679dfc695SMike Kravetz h->demote_order = h2->order; 317779dfc695SMike Kravetz } 3178e5ff2159SAndi Kleen } 3179e5ff2159SAndi Kleen } 3180e5ff2159SAndi Kleen 3181e5ff2159SAndi Kleen static void __init report_hugepages(void) 3182e5ff2159SAndi Kleen { 3183e5ff2159SAndi Kleen struct hstate *h; 3184e5ff2159SAndi Kleen 3185e5ff2159SAndi Kleen for_each_hstate(h) { 31864abd32dbSAndi Kleen char buf[32]; 3187c6247f72SMatthew Wilcox 3188c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 31896213834cSMuchun Song pr_info("HugeTLB: registered %s page size, pre-allocated %ld pages\n", 3190c6247f72SMatthew Wilcox buf, h->free_huge_pages); 31916213834cSMuchun Song pr_info("HugeTLB: %d KiB vmemmap can be freed for a %s page\n", 31926213834cSMuchun Song hugetlb_vmemmap_optimizable_size(h) / SZ_1K, buf); 3193e5ff2159SAndi Kleen } 3194e5ff2159SAndi Kleen } 3195e5ff2159SAndi Kleen 31961da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 31976ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 31986ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 31991da177e4SLinus Torvalds { 32004415cc8dSChristoph Lameter int i; 32011121828aSMike Kravetz LIST_HEAD(page_list); 32024415cc8dSChristoph Lameter 32039487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 3204bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3205aa888a74SAndi Kleen return; 3206aa888a74SAndi Kleen 32071121828aSMike Kravetz /* 32081121828aSMike Kravetz * Collect pages to be freed on a list, and free after dropping lock 32091121828aSMike Kravetz */ 32106ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 321110c6ec49SMike Kravetz struct page *page, *next; 3212a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 3213a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 3214a5516438SAndi Kleen if (count >= h->nr_huge_pages) 32151121828aSMike Kravetz goto out; 32161da177e4SLinus Torvalds if (PageHighMem(page)) 32171da177e4SLinus Torvalds continue; 32186eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 32191121828aSMike Kravetz list_add(&page->lru, &page_list); 32201121828aSMike Kravetz } 32211121828aSMike Kravetz } 32221121828aSMike Kravetz 32231121828aSMike Kravetz out: 3224db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 322510c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3226db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32271da177e4SLinus Torvalds } 32281da177e4SLinus Torvalds #else 32296ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 32306ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32311da177e4SLinus Torvalds { 32321da177e4SLinus Torvalds } 32331da177e4SLinus Torvalds #endif 32341da177e4SLinus Torvalds 323520a0307cSWu Fengguang /* 323620a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 323720a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 323820a0307cSWu Fengguang * Returns 1 if an adjustment was made. 323920a0307cSWu Fengguang */ 32406ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 32416ae11b27SLee Schermerhorn int delta) 324220a0307cSWu Fengguang { 3243b2261026SJoonsoo Kim int nr_nodes, node; 324420a0307cSWu Fengguang 32459487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 324620a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 324720a0307cSWu Fengguang 3248e8c5c824SLee Schermerhorn if (delta < 0) { 3249b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 3250b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 3251b2261026SJoonsoo Kim goto found; 3252b2261026SJoonsoo Kim } 3253b2261026SJoonsoo Kim } else { 3254b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 3255b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 3256b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 3257b2261026SJoonsoo Kim goto found; 3258e8c5c824SLee Schermerhorn } 32599a76db09SLee Schermerhorn } 3260b2261026SJoonsoo Kim return 0; 326120a0307cSWu Fengguang 3262b2261026SJoonsoo Kim found: 326320a0307cSWu Fengguang h->surplus_huge_pages += delta; 3264b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 3265b2261026SJoonsoo Kim return 1; 326620a0307cSWu Fengguang } 326720a0307cSWu Fengguang 3268a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 3269fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 32706ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32711da177e4SLinus Torvalds { 32727893d1d5SAdam Litke unsigned long min_count, ret; 327310c6ec49SMike Kravetz struct page *page; 327410c6ec49SMike Kravetz LIST_HEAD(page_list); 3275f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 3276f60858f9SMike Kravetz 3277f60858f9SMike Kravetz /* 3278f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3279f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 3280f60858f9SMike Kravetz * the requested huge pages. 3281f60858f9SMike Kravetz */ 3282f60858f9SMike Kravetz if (node_alloc_noretry) 3283f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 3284f60858f9SMike Kravetz else 3285f60858f9SMike Kravetz return -ENOMEM; 32861da177e4SLinus Torvalds 328729383967SMike Kravetz /* 328829383967SMike Kravetz * resize_lock mutex prevents concurrent adjustments to number of 328929383967SMike Kravetz * pages in hstate via the proc/sysfs interfaces. 329029383967SMike Kravetz */ 329129383967SMike Kravetz mutex_lock(&h->resize_lock); 3292b65d4adbSMuchun Song flush_free_hpage_work(h); 3293db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32944eb0716eSAlexandre Ghiti 32954eb0716eSAlexandre Ghiti /* 3296fd875dcaSMike Kravetz * Check for a node specific request. 3297fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 3298fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 3299fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 3300fd875dcaSMike Kravetz */ 3301fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 3302fd875dcaSMike Kravetz unsigned long old_count = count; 3303fd875dcaSMike Kravetz 3304fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 3305fd875dcaSMike Kravetz /* 3306fd875dcaSMike Kravetz * User may have specified a large count value which caused the 3307fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 3308fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 3309fd875dcaSMike Kravetz * largest possible value to align with their intention. 3310fd875dcaSMike Kravetz */ 3311fd875dcaSMike Kravetz if (count < old_count) 3312fd875dcaSMike Kravetz count = ULONG_MAX; 3313fd875dcaSMike Kravetz } 3314fd875dcaSMike Kravetz 3315fd875dcaSMike Kravetz /* 33164eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 33174eb0716eSAlexandre Ghiti * page range allocation. 33184eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 33194eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 33204eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 33214eb0716eSAlexandre Ghiti */ 33224eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 33234eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 3324db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 332529383967SMike Kravetz mutex_unlock(&h->resize_lock); 3326f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 33274eb0716eSAlexandre Ghiti return -EINVAL; 33284eb0716eSAlexandre Ghiti } 33294eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 33304eb0716eSAlexandre Ghiti } 3331aa888a74SAndi Kleen 33327893d1d5SAdam Litke /* 33337893d1d5SAdam Litke * Increase the pool size 33347893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 33357893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 3336d1c3fb1fSNishanth Aravamudan * 33370c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 3338d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 3339d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 3340d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 3341d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 33427893d1d5SAdam Litke */ 3343a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 33446ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 33457893d1d5SAdam Litke break; 33467893d1d5SAdam Litke } 33477893d1d5SAdam Litke 3348a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 33497893d1d5SAdam Litke /* 33507893d1d5SAdam Litke * If this allocation races such that we no longer need the 33517893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 33527893d1d5SAdam Litke * and reducing the surplus. 33537893d1d5SAdam Litke */ 3354db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3355649920c6SJia He 3356649920c6SJia He /* yield cpu to avoid soft lockup */ 3357649920c6SJia He cond_resched(); 3358649920c6SJia He 3359f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 3360f60858f9SMike Kravetz node_alloc_noretry); 3361db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 33627893d1d5SAdam Litke if (!ret) 33637893d1d5SAdam Litke goto out; 33647893d1d5SAdam Litke 3365536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 3366536240f2SMel Gorman if (signal_pending(current)) 3367536240f2SMel Gorman goto out; 33687893d1d5SAdam Litke } 33697893d1d5SAdam Litke 33707893d1d5SAdam Litke /* 33717893d1d5SAdam Litke * Decrease the pool size 33727893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 33737893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 33747893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 33757893d1d5SAdam Litke * to the desired size as pages become free. 3376d1c3fb1fSNishanth Aravamudan * 3377d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 3378d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 3379d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 33800c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 3381d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 3382d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 3383d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 33847893d1d5SAdam Litke */ 3385a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 33866b0c880dSAdam Litke min_count = max(count, min_count); 33876ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 338810c6ec49SMike Kravetz 338910c6ec49SMike Kravetz /* 339010c6ec49SMike Kravetz * Collect pages to be removed on list without dropping lock 339110c6ec49SMike Kravetz */ 3392a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 339310c6ec49SMike Kravetz page = remove_pool_huge_page(h, nodes_allowed, 0); 339410c6ec49SMike Kravetz if (!page) 33951da177e4SLinus Torvalds break; 339610c6ec49SMike Kravetz 339710c6ec49SMike Kravetz list_add(&page->lru, &page_list); 33981da177e4SLinus Torvalds } 339910c6ec49SMike Kravetz /* free the pages after dropping lock */ 3400db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 340110c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3402b65d4adbSMuchun Song flush_free_hpage_work(h); 3403db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 340410c6ec49SMike Kravetz 3405a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 34066ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 34077893d1d5SAdam Litke break; 34087893d1d5SAdam Litke } 34097893d1d5SAdam Litke out: 34104eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 3411db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 341229383967SMike Kravetz mutex_unlock(&h->resize_lock); 34134eb0716eSAlexandre Ghiti 3414f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 3415f60858f9SMike Kravetz 34164eb0716eSAlexandre Ghiti return 0; 34171da177e4SLinus Torvalds } 34181da177e4SLinus Torvalds 34198531fc6fSMike Kravetz static int demote_free_huge_page(struct hstate *h, struct page *page) 34208531fc6fSMike Kravetz { 34218531fc6fSMike Kravetz int i, nid = page_to_nid(page); 34228531fc6fSMike Kravetz struct hstate *target_hstate; 3423*31731452SDoug Berger struct page *subpage; 34248531fc6fSMike Kravetz int rc = 0; 34258531fc6fSMike Kravetz 34268531fc6fSMike Kravetz target_hstate = size_to_hstate(PAGE_SIZE << h->demote_order); 34278531fc6fSMike Kravetz 34288531fc6fSMike Kravetz remove_hugetlb_page_for_demote(h, page, false); 34298531fc6fSMike Kravetz spin_unlock_irq(&hugetlb_lock); 34308531fc6fSMike Kravetz 34316213834cSMuchun Song rc = hugetlb_vmemmap_restore(h, page); 34328531fc6fSMike Kravetz if (rc) { 34338531fc6fSMike Kravetz /* Allocation of vmemmmap failed, we can not demote page */ 34348531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34358531fc6fSMike Kravetz set_page_refcounted(page); 34368531fc6fSMike Kravetz add_hugetlb_page(h, page, false); 34378531fc6fSMike Kravetz return rc; 34388531fc6fSMike Kravetz } 34398531fc6fSMike Kravetz 34408531fc6fSMike Kravetz /* 34418531fc6fSMike Kravetz * Use destroy_compound_hugetlb_page_for_demote for all huge page 34428531fc6fSMike Kravetz * sizes as it will not ref count pages. 34438531fc6fSMike Kravetz */ 34448531fc6fSMike Kravetz destroy_compound_hugetlb_page_for_demote(page, huge_page_order(h)); 34458531fc6fSMike Kravetz 34468531fc6fSMike Kravetz /* 34478531fc6fSMike Kravetz * Taking target hstate mutex synchronizes with set_max_huge_pages. 34488531fc6fSMike Kravetz * Without the mutex, pages added to target hstate could be marked 34498531fc6fSMike Kravetz * as surplus. 34508531fc6fSMike Kravetz * 34518531fc6fSMike Kravetz * Note that we already hold h->resize_lock. To prevent deadlock, 34528531fc6fSMike Kravetz * use the convention of always taking larger size hstate mutex first. 34538531fc6fSMike Kravetz */ 34548531fc6fSMike Kravetz mutex_lock(&target_hstate->resize_lock); 34558531fc6fSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 34568531fc6fSMike Kravetz i += pages_per_huge_page(target_hstate)) { 3457*31731452SDoug Berger subpage = nth_page(page, i); 34588531fc6fSMike Kravetz if (hstate_is_gigantic(target_hstate)) 3459*31731452SDoug Berger prep_compound_gigantic_page_for_demote(subpage, 34608531fc6fSMike Kravetz target_hstate->order); 34618531fc6fSMike Kravetz else 3462*31731452SDoug Berger prep_compound_page(subpage, target_hstate->order); 3463*31731452SDoug Berger set_page_private(subpage, 0); 3464*31731452SDoug Berger set_page_refcounted(subpage); 3465*31731452SDoug Berger prep_new_huge_page(target_hstate, subpage, nid); 3466*31731452SDoug Berger put_page(subpage); 34678531fc6fSMike Kravetz } 34688531fc6fSMike Kravetz mutex_unlock(&target_hstate->resize_lock); 34698531fc6fSMike Kravetz 34708531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34718531fc6fSMike Kravetz 34728531fc6fSMike Kravetz /* 34738531fc6fSMike Kravetz * Not absolutely necessary, but for consistency update max_huge_pages 34748531fc6fSMike Kravetz * based on pool changes for the demoted page. 34758531fc6fSMike Kravetz */ 34768531fc6fSMike Kravetz h->max_huge_pages--; 34778531fc6fSMike Kravetz target_hstate->max_huge_pages += pages_per_huge_page(h); 34788531fc6fSMike Kravetz 34798531fc6fSMike Kravetz return rc; 34808531fc6fSMike Kravetz } 34818531fc6fSMike Kravetz 348279dfc695SMike Kravetz static int demote_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed) 348379dfc695SMike Kravetz __must_hold(&hugetlb_lock) 348479dfc695SMike Kravetz { 34858531fc6fSMike Kravetz int nr_nodes, node; 34868531fc6fSMike Kravetz struct page *page; 348779dfc695SMike Kravetz 348879dfc695SMike Kravetz lockdep_assert_held(&hugetlb_lock); 348979dfc695SMike Kravetz 349079dfc695SMike Kravetz /* We should never get here if no demote order */ 349179dfc695SMike Kravetz if (!h->demote_order) { 349279dfc695SMike Kravetz pr_warn("HugeTLB: NULL demote order passed to demote_pool_huge_page.\n"); 349379dfc695SMike Kravetz return -EINVAL; /* internal error */ 349479dfc695SMike Kravetz } 349579dfc695SMike Kravetz 34968531fc6fSMike Kravetz for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 34975a317412SMike Kravetz list_for_each_entry(page, &h->hugepage_freelists[node], lru) { 34985a317412SMike Kravetz if (PageHWPoison(page)) 34995a317412SMike Kravetz continue; 35005a317412SMike Kravetz 35015a317412SMike Kravetz return demote_free_huge_page(h, page); 35028531fc6fSMike Kravetz } 35038531fc6fSMike Kravetz } 35048531fc6fSMike Kravetz 35055a317412SMike Kravetz /* 35065a317412SMike Kravetz * Only way to get here is if all pages on free lists are poisoned. 35075a317412SMike Kravetz * Return -EBUSY so that caller will not retry. 35085a317412SMike Kravetz */ 35095a317412SMike Kravetz return -EBUSY; 351079dfc695SMike Kravetz } 351179dfc695SMike Kravetz 3512a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 3513a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 3514a3437870SNishanth Aravamudan 351579dfc695SMike Kravetz #define HSTATE_ATTR_WO(_name) \ 351679dfc695SMike Kravetz static struct kobj_attribute _name##_attr = __ATTR_WO(_name) 351779dfc695SMike Kravetz 3518a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 351998bc26acSMiaohe Lin static struct kobj_attribute _name##_attr = __ATTR_RW(_name) 3520a3437870SNishanth Aravamudan 3521a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 3522a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 3523a3437870SNishanth Aravamudan 35249a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 35259a305230SLee Schermerhorn 35269a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 3527a3437870SNishanth Aravamudan { 3528a3437870SNishanth Aravamudan int i; 35299a305230SLee Schermerhorn 3530a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 35319a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 35329a305230SLee Schermerhorn if (nidp) 35339a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 3534a3437870SNishanth Aravamudan return &hstates[i]; 35359a305230SLee Schermerhorn } 35369a305230SLee Schermerhorn 35379a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 3538a3437870SNishanth Aravamudan } 3539a3437870SNishanth Aravamudan 354006808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 3541a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3542a3437870SNishanth Aravamudan { 35439a305230SLee Schermerhorn struct hstate *h; 35449a305230SLee Schermerhorn unsigned long nr_huge_pages; 35459a305230SLee Schermerhorn int nid; 35469a305230SLee Schermerhorn 35479a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 35489a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 35499a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 35509a305230SLee Schermerhorn else 35519a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 35529a305230SLee Schermerhorn 3553ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", nr_huge_pages); 3554a3437870SNishanth Aravamudan } 3555adbe8726SEric B Munson 3556238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 3557238d3c13SDavid Rientjes struct hstate *h, int nid, 3558238d3c13SDavid Rientjes unsigned long count, size_t len) 3559a3437870SNishanth Aravamudan { 3560a3437870SNishanth Aravamudan int err; 35612d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 3562a3437870SNishanth Aravamudan 35632d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 35642d0adf7eSOscar Salvador return -EINVAL; 3565adbe8726SEric B Munson 35669a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 35679a305230SLee Schermerhorn /* 35689a305230SLee Schermerhorn * global hstate attribute 35699a305230SLee Schermerhorn */ 35709a305230SLee Schermerhorn if (!(obey_mempolicy && 35712d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 35722d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 35732d0adf7eSOscar Salvador else 35742d0adf7eSOscar Salvador n_mask = &nodes_allowed; 35752d0adf7eSOscar Salvador } else { 35769a305230SLee Schermerhorn /* 3577fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 3578fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 35799a305230SLee Schermerhorn */ 35802d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 35812d0adf7eSOscar Salvador n_mask = &nodes_allowed; 3582fd875dcaSMike Kravetz } 35839a305230SLee Schermerhorn 35842d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 358506808b08SLee Schermerhorn 35864eb0716eSAlexandre Ghiti return err ? err : len; 358706808b08SLee Schermerhorn } 358806808b08SLee Schermerhorn 3589238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 3590238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 3591238d3c13SDavid Rientjes size_t len) 3592238d3c13SDavid Rientjes { 3593238d3c13SDavid Rientjes struct hstate *h; 3594238d3c13SDavid Rientjes unsigned long count; 3595238d3c13SDavid Rientjes int nid; 3596238d3c13SDavid Rientjes int err; 3597238d3c13SDavid Rientjes 3598238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 3599238d3c13SDavid Rientjes if (err) 3600238d3c13SDavid Rientjes return err; 3601238d3c13SDavid Rientjes 3602238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 3603238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 3604238d3c13SDavid Rientjes } 3605238d3c13SDavid Rientjes 360606808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 360706808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 360806808b08SLee Schermerhorn { 360906808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 361006808b08SLee Schermerhorn } 361106808b08SLee Schermerhorn 361206808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 361306808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 361406808b08SLee Schermerhorn { 3615238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 3616a3437870SNishanth Aravamudan } 3617a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 3618a3437870SNishanth Aravamudan 361906808b08SLee Schermerhorn #ifdef CONFIG_NUMA 362006808b08SLee Schermerhorn 362106808b08SLee Schermerhorn /* 362206808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 362306808b08SLee Schermerhorn * huge page alloc/free. 362406808b08SLee Schermerhorn */ 362506808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 3626ae7a927dSJoe Perches struct kobj_attribute *attr, 3627ae7a927dSJoe Perches char *buf) 362806808b08SLee Schermerhorn { 362906808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 363006808b08SLee Schermerhorn } 363106808b08SLee Schermerhorn 363206808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 363306808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 363406808b08SLee Schermerhorn { 3635238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 363606808b08SLee Schermerhorn } 363706808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 363806808b08SLee Schermerhorn #endif 363906808b08SLee Schermerhorn 364006808b08SLee Schermerhorn 3641a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 3642a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3643a3437870SNishanth Aravamudan { 36449a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3645ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages); 3646a3437870SNishanth Aravamudan } 3647adbe8726SEric B Munson 3648a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 3649a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 3650a3437870SNishanth Aravamudan { 3651a3437870SNishanth Aravamudan int err; 3652a3437870SNishanth Aravamudan unsigned long input; 36539a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3654a3437870SNishanth Aravamudan 3655bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3656adbe8726SEric B Munson return -EINVAL; 3657adbe8726SEric B Munson 36583dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 3659a3437870SNishanth Aravamudan if (err) 366073ae31e5SEric B Munson return err; 3661a3437870SNishanth Aravamudan 3662db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3663a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 3664db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3665a3437870SNishanth Aravamudan 3666a3437870SNishanth Aravamudan return count; 3667a3437870SNishanth Aravamudan } 3668a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 3669a3437870SNishanth Aravamudan 3670a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 3671a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3672a3437870SNishanth Aravamudan { 36739a305230SLee Schermerhorn struct hstate *h; 36749a305230SLee Schermerhorn unsigned long free_huge_pages; 36759a305230SLee Schermerhorn int nid; 36769a305230SLee Schermerhorn 36779a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 36789a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 36799a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 36809a305230SLee Schermerhorn else 36819a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 36829a305230SLee Schermerhorn 3683ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", free_huge_pages); 3684a3437870SNishanth Aravamudan } 3685a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 3686a3437870SNishanth Aravamudan 3687a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 3688a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3689a3437870SNishanth Aravamudan { 36909a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3691ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->resv_huge_pages); 3692a3437870SNishanth Aravamudan } 3693a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 3694a3437870SNishanth Aravamudan 3695a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 3696a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3697a3437870SNishanth Aravamudan { 36989a305230SLee Schermerhorn struct hstate *h; 36999a305230SLee Schermerhorn unsigned long surplus_huge_pages; 37009a305230SLee Schermerhorn int nid; 37019a305230SLee Schermerhorn 37029a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 37039a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 37049a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 37059a305230SLee Schermerhorn else 37069a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 37079a305230SLee Schermerhorn 3708ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", surplus_huge_pages); 3709a3437870SNishanth Aravamudan } 3710a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3711a3437870SNishanth Aravamudan 371279dfc695SMike Kravetz static ssize_t demote_store(struct kobject *kobj, 371379dfc695SMike Kravetz struct kobj_attribute *attr, const char *buf, size_t len) 371479dfc695SMike Kravetz { 371579dfc695SMike Kravetz unsigned long nr_demote; 371679dfc695SMike Kravetz unsigned long nr_available; 371779dfc695SMike Kravetz nodemask_t nodes_allowed, *n_mask; 371879dfc695SMike Kravetz struct hstate *h; 371979dfc695SMike Kravetz int err = 0; 372079dfc695SMike Kravetz int nid; 372179dfc695SMike Kravetz 372279dfc695SMike Kravetz err = kstrtoul(buf, 10, &nr_demote); 372379dfc695SMike Kravetz if (err) 372479dfc695SMike Kravetz return err; 372579dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 372679dfc695SMike Kravetz 372779dfc695SMike Kravetz if (nid != NUMA_NO_NODE) { 372879dfc695SMike Kravetz init_nodemask_of_node(&nodes_allowed, nid); 372979dfc695SMike Kravetz n_mask = &nodes_allowed; 373079dfc695SMike Kravetz } else { 373179dfc695SMike Kravetz n_mask = &node_states[N_MEMORY]; 373279dfc695SMike Kravetz } 373379dfc695SMike Kravetz 373479dfc695SMike Kravetz /* Synchronize with other sysfs operations modifying huge pages */ 373579dfc695SMike Kravetz mutex_lock(&h->resize_lock); 373679dfc695SMike Kravetz spin_lock_irq(&hugetlb_lock); 373779dfc695SMike Kravetz 373879dfc695SMike Kravetz while (nr_demote) { 373979dfc695SMike Kravetz /* 374079dfc695SMike Kravetz * Check for available pages to demote each time thorough the 374179dfc695SMike Kravetz * loop as demote_pool_huge_page will drop hugetlb_lock. 374279dfc695SMike Kravetz */ 374379dfc695SMike Kravetz if (nid != NUMA_NO_NODE) 374479dfc695SMike Kravetz nr_available = h->free_huge_pages_node[nid]; 374579dfc695SMike Kravetz else 374679dfc695SMike Kravetz nr_available = h->free_huge_pages; 374779dfc695SMike Kravetz nr_available -= h->resv_huge_pages; 374879dfc695SMike Kravetz if (!nr_available) 374979dfc695SMike Kravetz break; 375079dfc695SMike Kravetz 375179dfc695SMike Kravetz err = demote_pool_huge_page(h, n_mask); 375279dfc695SMike Kravetz if (err) 375379dfc695SMike Kravetz break; 375479dfc695SMike Kravetz 375579dfc695SMike Kravetz nr_demote--; 375679dfc695SMike Kravetz } 375779dfc695SMike Kravetz 375879dfc695SMike Kravetz spin_unlock_irq(&hugetlb_lock); 375979dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 376079dfc695SMike Kravetz 376179dfc695SMike Kravetz if (err) 376279dfc695SMike Kravetz return err; 376379dfc695SMike Kravetz return len; 376479dfc695SMike Kravetz } 376579dfc695SMike Kravetz HSTATE_ATTR_WO(demote); 376679dfc695SMike Kravetz 376779dfc695SMike Kravetz static ssize_t demote_size_show(struct kobject *kobj, 376879dfc695SMike Kravetz struct kobj_attribute *attr, char *buf) 376979dfc695SMike Kravetz { 377079dfc695SMike Kravetz int nid; 377179dfc695SMike Kravetz struct hstate *h = kobj_to_hstate(kobj, &nid); 377279dfc695SMike Kravetz unsigned long demote_size = (PAGE_SIZE << h->demote_order) / SZ_1K; 377379dfc695SMike Kravetz 377479dfc695SMike Kravetz return sysfs_emit(buf, "%lukB\n", demote_size); 377579dfc695SMike Kravetz } 377679dfc695SMike Kravetz 377779dfc695SMike Kravetz static ssize_t demote_size_store(struct kobject *kobj, 377879dfc695SMike Kravetz struct kobj_attribute *attr, 377979dfc695SMike Kravetz const char *buf, size_t count) 378079dfc695SMike Kravetz { 378179dfc695SMike Kravetz struct hstate *h, *demote_hstate; 378279dfc695SMike Kravetz unsigned long demote_size; 378379dfc695SMike Kravetz unsigned int demote_order; 378479dfc695SMike Kravetz int nid; 378579dfc695SMike Kravetz 378679dfc695SMike Kravetz demote_size = (unsigned long)memparse(buf, NULL); 378779dfc695SMike Kravetz 378879dfc695SMike Kravetz demote_hstate = size_to_hstate(demote_size); 378979dfc695SMike Kravetz if (!demote_hstate) 379079dfc695SMike Kravetz return -EINVAL; 379179dfc695SMike Kravetz demote_order = demote_hstate->order; 3792a01f4390SMike Kravetz if (demote_order < HUGETLB_PAGE_ORDER) 3793a01f4390SMike Kravetz return -EINVAL; 379479dfc695SMike Kravetz 379579dfc695SMike Kravetz /* demote order must be smaller than hstate order */ 379679dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 379779dfc695SMike Kravetz if (demote_order >= h->order) 379879dfc695SMike Kravetz return -EINVAL; 379979dfc695SMike Kravetz 380079dfc695SMike Kravetz /* resize_lock synchronizes access to demote size and writes */ 380179dfc695SMike Kravetz mutex_lock(&h->resize_lock); 380279dfc695SMike Kravetz h->demote_order = demote_order; 380379dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 380479dfc695SMike Kravetz 380579dfc695SMike Kravetz return count; 380679dfc695SMike Kravetz } 380779dfc695SMike Kravetz HSTATE_ATTR(demote_size); 380879dfc695SMike Kravetz 3809a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3810a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3811a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3812a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3813a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3814a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 381506808b08SLee Schermerhorn #ifdef CONFIG_NUMA 381606808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 381706808b08SLee Schermerhorn #endif 3818a3437870SNishanth Aravamudan NULL, 3819a3437870SNishanth Aravamudan }; 3820a3437870SNishanth Aravamudan 382167e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3822a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3823a3437870SNishanth Aravamudan }; 3824a3437870SNishanth Aravamudan 382579dfc695SMike Kravetz static struct attribute *hstate_demote_attrs[] = { 382679dfc695SMike Kravetz &demote_size_attr.attr, 382779dfc695SMike Kravetz &demote_attr.attr, 382879dfc695SMike Kravetz NULL, 382979dfc695SMike Kravetz }; 383079dfc695SMike Kravetz 383179dfc695SMike Kravetz static const struct attribute_group hstate_demote_attr_group = { 383279dfc695SMike Kravetz .attrs = hstate_demote_attrs, 383379dfc695SMike Kravetz }; 383479dfc695SMike Kravetz 3835094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 38369a305230SLee Schermerhorn struct kobject **hstate_kobjs, 383767e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 3838a3437870SNishanth Aravamudan { 3839a3437870SNishanth Aravamudan int retval; 3840972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 3841a3437870SNishanth Aravamudan 38429a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 38439a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 3844a3437870SNishanth Aravamudan return -ENOMEM; 3845a3437870SNishanth Aravamudan 38469a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 3847cc2205a6SMiaohe Lin if (retval) { 38489a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 3849cc2205a6SMiaohe Lin hstate_kobjs[hi] = NULL; 3850cc2205a6SMiaohe Lin } 3851a3437870SNishanth Aravamudan 385279dfc695SMike Kravetz if (h->demote_order) { 385379dfc695SMike Kravetz if (sysfs_create_group(hstate_kobjs[hi], 385479dfc695SMike Kravetz &hstate_demote_attr_group)) 385579dfc695SMike Kravetz pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name); 385679dfc695SMike Kravetz } 385779dfc695SMike Kravetz 3858a3437870SNishanth Aravamudan return retval; 3859a3437870SNishanth Aravamudan } 3860a3437870SNishanth Aravamudan 3861a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 3862a3437870SNishanth Aravamudan { 3863a3437870SNishanth Aravamudan struct hstate *h; 3864a3437870SNishanth Aravamudan int err; 3865a3437870SNishanth Aravamudan 3866a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 3867a3437870SNishanth Aravamudan if (!hugepages_kobj) 3868a3437870SNishanth Aravamudan return; 3869a3437870SNishanth Aravamudan 3870a3437870SNishanth Aravamudan for_each_hstate(h) { 38719a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 38729a305230SLee Schermerhorn hstate_kobjs, &hstate_attr_group); 3873a3437870SNishanth Aravamudan if (err) 3874282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s", h->name); 3875a3437870SNishanth Aravamudan } 3876a3437870SNishanth Aravamudan } 3877a3437870SNishanth Aravamudan 38789a305230SLee Schermerhorn #ifdef CONFIG_NUMA 38799a305230SLee Schermerhorn 38809a305230SLee Schermerhorn /* 38819a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 388210fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 388310fbcf4cSKay Sievers * index of a node device or _hstate == node id. 388410fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 38859a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 38869a305230SLee Schermerhorn */ 38879a305230SLee Schermerhorn struct node_hstate { 38889a305230SLee Schermerhorn struct kobject *hugepages_kobj; 38899a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 38909a305230SLee Schermerhorn }; 3891b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 38929a305230SLee Schermerhorn 38939a305230SLee Schermerhorn /* 389410fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 38959a305230SLee Schermerhorn */ 38969a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 38979a305230SLee Schermerhorn &nr_hugepages_attr.attr, 38989a305230SLee Schermerhorn &free_hugepages_attr.attr, 38999a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 39009a305230SLee Schermerhorn NULL, 39019a305230SLee Schermerhorn }; 39029a305230SLee Schermerhorn 390367e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 39049a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 39059a305230SLee Schermerhorn }; 39069a305230SLee Schermerhorn 39079a305230SLee Schermerhorn /* 390810fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 39099a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 39109a305230SLee Schermerhorn */ 39119a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 39129a305230SLee Schermerhorn { 39139a305230SLee Schermerhorn int nid; 39149a305230SLee Schermerhorn 39159a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 39169a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 39179a305230SLee Schermerhorn int i; 39189a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 39199a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 39209a305230SLee Schermerhorn if (nidp) 39219a305230SLee Schermerhorn *nidp = nid; 39229a305230SLee Schermerhorn return &hstates[i]; 39239a305230SLee Schermerhorn } 39249a305230SLee Schermerhorn } 39259a305230SLee Schermerhorn 39269a305230SLee Schermerhorn BUG(); 39279a305230SLee Schermerhorn return NULL; 39289a305230SLee Schermerhorn } 39299a305230SLee Schermerhorn 39309a305230SLee Schermerhorn /* 393110fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 39329a305230SLee Schermerhorn * No-op if no hstate attributes attached. 39339a305230SLee Schermerhorn */ 39343cd8b44fSClaudiu Ghioc static void hugetlb_unregister_node(struct node *node) 39359a305230SLee Schermerhorn { 39369a305230SLee Schermerhorn struct hstate *h; 393710fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39389a305230SLee Schermerhorn 39399a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39409b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 39419a305230SLee Schermerhorn 3942972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3943972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 3944972dc4deSAneesh Kumar K.V if (nhs->hstate_kobjs[idx]) { 3945972dc4deSAneesh Kumar K.V kobject_put(nhs->hstate_kobjs[idx]); 3946972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3947972dc4deSAneesh Kumar K.V } 39489a305230SLee Schermerhorn } 39499a305230SLee Schermerhorn 39509a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 39519a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 39529a305230SLee Schermerhorn } 39539a305230SLee Schermerhorn 39549a305230SLee Schermerhorn 39559a305230SLee Schermerhorn /* 395610fbcf4cSKay Sievers * Register hstate attributes for a single node device. 39579a305230SLee Schermerhorn * No-op if attributes already registered. 39589a305230SLee Schermerhorn */ 39593cd8b44fSClaudiu Ghioc static void hugetlb_register_node(struct node *node) 39609a305230SLee Schermerhorn { 39619a305230SLee Schermerhorn struct hstate *h; 396210fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39639a305230SLee Schermerhorn int err; 39649a305230SLee Schermerhorn 39659a305230SLee Schermerhorn if (nhs->hugepages_kobj) 39669a305230SLee Schermerhorn return; /* already allocated */ 39679a305230SLee Schermerhorn 39689a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 396910fbcf4cSKay Sievers &node->dev.kobj); 39709a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39719a305230SLee Schermerhorn return; 39729a305230SLee Schermerhorn 39739a305230SLee Schermerhorn for_each_hstate(h) { 39749a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 39759a305230SLee Schermerhorn nhs->hstate_kobjs, 39769a305230SLee Schermerhorn &per_node_hstate_attr_group); 39779a305230SLee Schermerhorn if (err) { 3978282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 397910fbcf4cSKay Sievers h->name, node->dev.id); 39809a305230SLee Schermerhorn hugetlb_unregister_node(node); 39819a305230SLee Schermerhorn break; 39829a305230SLee Schermerhorn } 39839a305230SLee Schermerhorn } 39849a305230SLee Schermerhorn } 39859a305230SLee Schermerhorn 39869a305230SLee Schermerhorn /* 39879b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 398810fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 398910fbcf4cSKay Sievers * registered their associated device by this time. 39909a305230SLee Schermerhorn */ 39917d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 39929a305230SLee Schermerhorn { 39939a305230SLee Schermerhorn int nid; 39949a305230SLee Schermerhorn 39958cebfcd0SLai Jiangshan for_each_node_state(nid, N_MEMORY) { 39968732794bSWen Congyang struct node *node = node_devices[nid]; 399710fbcf4cSKay Sievers if (node->dev.id == nid) 39989a305230SLee Schermerhorn hugetlb_register_node(node); 39999a305230SLee Schermerhorn } 40009a305230SLee Schermerhorn 40019a305230SLee Schermerhorn /* 400210fbcf4cSKay Sievers * Let the node device driver know we're here so it can 40039a305230SLee Schermerhorn * [un]register hstate attributes on node hotplug. 40049a305230SLee Schermerhorn */ 40059a305230SLee Schermerhorn register_hugetlbfs_with_node(hugetlb_register_node, 40069a305230SLee Schermerhorn hugetlb_unregister_node); 40079a305230SLee Schermerhorn } 40089a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 40099a305230SLee Schermerhorn 40109a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 40119a305230SLee Schermerhorn { 40129a305230SLee Schermerhorn BUG(); 40139a305230SLee Schermerhorn if (nidp) 40149a305230SLee Schermerhorn *nidp = -1; 40159a305230SLee Schermerhorn return NULL; 40169a305230SLee Schermerhorn } 40179a305230SLee Schermerhorn 40189a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 40199a305230SLee Schermerhorn 40209a305230SLee Schermerhorn #endif 40219a305230SLee Schermerhorn 4022a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 4023a3437870SNishanth Aravamudan { 40248382d914SDavidlohr Bueso int i; 40258382d914SDavidlohr Bueso 4026d6995da3SMike Kravetz BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < 4027d6995da3SMike Kravetz __NR_HPAGEFLAGS); 4028d6995da3SMike Kravetz 4029c2833a5bSMike Kravetz if (!hugepages_supported()) { 4030c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 4031c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 40320ef89d25SBenjamin Herrenschmidt return 0; 4033d715cf80SLiam R. Howlett } 4034d715cf80SLiam R. Howlett 4035282f4214SMike Kravetz /* 4036282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 4037282f4214SMike Kravetz * architectures depend on setup being done here. 4038282f4214SMike Kravetz */ 4039a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 4040282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 4041282f4214SMike Kravetz /* 4042282f4214SMike Kravetz * If we did not parse a default huge page size, set 4043282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 4044282f4214SMike Kravetz * number of huge pages for this default size was implicitly 4045282f4214SMike Kravetz * specified, set that here as well. 4046282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 4047282f4214SMike Kravetz * setting. A warning will be printed in this case. 4048282f4214SMike Kravetz */ 4049282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 4050f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 4051282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 4052282f4214SMike Kravetz char buf[32]; 4053282f4214SMike Kravetz 4054282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 4055282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 4056282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 4057282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 4058282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 4059282f4214SMike Kravetz default_hstate_max_huge_pages); 4060282f4214SMike Kravetz } 4061282f4214SMike Kravetz default_hstate.max_huge_pages = 4062282f4214SMike Kravetz default_hstate_max_huge_pages; 4063b5389086SZhenguo Yao 40640a7a0f6fSPeng Liu for_each_online_node(i) 4065b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4066b5389086SZhenguo Yao default_hugepages_in_node[i]; 4067282f4214SMike Kravetz } 4068f8b74815SVaishali Thakkar } 4069a3437870SNishanth Aravamudan 4070cf11e85fSRoman Gushchin hugetlb_cma_check(); 4071a3437870SNishanth Aravamudan hugetlb_init_hstates(); 4072aa888a74SAndi Kleen gather_bootmem_prealloc(); 4073a3437870SNishanth Aravamudan report_hugepages(); 4074a3437870SNishanth Aravamudan 4075a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 40769a305230SLee Schermerhorn hugetlb_register_all_nodes(); 40777179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 40789a305230SLee Schermerhorn 40798382d914SDavidlohr Bueso #ifdef CONFIG_SMP 40808382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 40818382d914SDavidlohr Bueso #else 40828382d914SDavidlohr Bueso num_fault_mutexes = 1; 40838382d914SDavidlohr Bueso #endif 4084c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 40856da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 40866da2ec56SKees Cook GFP_KERNEL); 4087c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 40888382d914SDavidlohr Bueso 40898382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 4090c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 4091a3437870SNishanth Aravamudan return 0; 4092a3437870SNishanth Aravamudan } 40933e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 4094a3437870SNishanth Aravamudan 4095ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 4096ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 40979fee021dSVaishali Thakkar { 4098ae94da89SMike Kravetz return size == HPAGE_SIZE; 40999fee021dSVaishali Thakkar } 41009fee021dSVaishali Thakkar 4101d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 4102a3437870SNishanth Aravamudan { 4103a3437870SNishanth Aravamudan struct hstate *h; 41048faa8b07SAndi Kleen unsigned long i; 41058faa8b07SAndi Kleen 4106a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 4107a3437870SNishanth Aravamudan return; 4108a3437870SNishanth Aravamudan } 410947d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 4110a3437870SNishanth Aravamudan BUG_ON(order == 0); 411147d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 411229383967SMike Kravetz mutex_init(&h->resize_lock); 4113a3437870SNishanth Aravamudan h->order = order; 4114aca78307SMiaohe Lin h->mask = ~(huge_page_size(h) - 1); 41158faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 41168faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 41170edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 411854f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 411954f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 4120a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 4121a3437870SNishanth Aravamudan huge_page_size(h)/1024); 41228faa8b07SAndi Kleen 4123a3437870SNishanth Aravamudan parsed_hstate = h; 4124a3437870SNishanth Aravamudan } 4125a3437870SNishanth Aravamudan 4126b5389086SZhenguo Yao bool __init __weak hugetlb_node_alloc_supported(void) 4127b5389086SZhenguo Yao { 4128b5389086SZhenguo Yao return true; 4129b5389086SZhenguo Yao } 4130f87442f4SPeng Liu 4131f87442f4SPeng Liu static void __init hugepages_clear_pages_in_node(void) 4132f87442f4SPeng Liu { 4133f87442f4SPeng Liu if (!hugetlb_max_hstate) { 4134f87442f4SPeng Liu default_hstate_max_huge_pages = 0; 4135f87442f4SPeng Liu memset(default_hugepages_in_node, 0, 4136f87442f4SPeng Liu MAX_NUMNODES * sizeof(unsigned int)); 4137f87442f4SPeng Liu } else { 4138f87442f4SPeng Liu parsed_hstate->max_huge_pages = 0; 4139f87442f4SPeng Liu memset(parsed_hstate->max_huge_pages_node, 0, 4140f87442f4SPeng Liu MAX_NUMNODES * sizeof(unsigned int)); 4141f87442f4SPeng Liu } 4142f87442f4SPeng Liu } 4143f87442f4SPeng Liu 4144282f4214SMike Kravetz /* 4145282f4214SMike Kravetz * hugepages command line processing 4146282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 4147282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 4148282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 4149282f4214SMike Kravetz * specifies the number of huge pages for the default size. 4150282f4214SMike Kravetz */ 4151282f4214SMike Kravetz static int __init hugepages_setup(char *s) 4152a3437870SNishanth Aravamudan { 4153a3437870SNishanth Aravamudan unsigned long *mhp; 41548faa8b07SAndi Kleen static unsigned long *last_mhp; 4155b5389086SZhenguo Yao int node = NUMA_NO_NODE; 4156b5389086SZhenguo Yao int count; 4157b5389086SZhenguo Yao unsigned long tmp; 4158b5389086SZhenguo Yao char *p = s; 4159a3437870SNishanth Aravamudan 41609fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 4161282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 41629fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 4163f81f6e4bSPeng Liu return 1; 41649fee021dSVaishali Thakkar } 4165282f4214SMike Kravetz 4166a3437870SNishanth Aravamudan /* 4167282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 4168282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 4169282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 4170282f4214SMike Kravetz * default_hugepagesz. 4171a3437870SNishanth Aravamudan */ 41729fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 4173a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 4174a3437870SNishanth Aravamudan else 4175a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 4176a3437870SNishanth Aravamudan 41778faa8b07SAndi Kleen if (mhp == last_mhp) { 4178282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 4179f81f6e4bSPeng Liu return 1; 41808faa8b07SAndi Kleen } 41818faa8b07SAndi Kleen 4182b5389086SZhenguo Yao while (*p) { 4183b5389086SZhenguo Yao count = 0; 4184b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4185b5389086SZhenguo Yao goto invalid; 4186b5389086SZhenguo Yao /* Parameter is node format */ 4187b5389086SZhenguo Yao if (p[count] == ':') { 4188b5389086SZhenguo Yao if (!hugetlb_node_alloc_supported()) { 4189b5389086SZhenguo Yao pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); 4190f81f6e4bSPeng Liu return 1; 4191b5389086SZhenguo Yao } 41920a7a0f6fSPeng Liu if (tmp >= MAX_NUMNODES || !node_online(tmp)) 4193e79ce983SLiu Yuntao goto invalid; 41940a7a0f6fSPeng Liu node = array_index_nospec(tmp, MAX_NUMNODES); 4195b5389086SZhenguo Yao p += count + 1; 4196b5389086SZhenguo Yao /* Parse hugepages */ 4197b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4198b5389086SZhenguo Yao goto invalid; 4199b5389086SZhenguo Yao if (!hugetlb_max_hstate) 4200b5389086SZhenguo Yao default_hugepages_in_node[node] = tmp; 4201b5389086SZhenguo Yao else 4202b5389086SZhenguo Yao parsed_hstate->max_huge_pages_node[node] = tmp; 4203b5389086SZhenguo Yao *mhp += tmp; 4204b5389086SZhenguo Yao /* Go to parse next node*/ 4205b5389086SZhenguo Yao if (p[count] == ',') 4206b5389086SZhenguo Yao p += count + 1; 4207b5389086SZhenguo Yao else 4208b5389086SZhenguo Yao break; 4209b5389086SZhenguo Yao } else { 4210b5389086SZhenguo Yao if (p != s) 4211b5389086SZhenguo Yao goto invalid; 4212b5389086SZhenguo Yao *mhp = tmp; 4213b5389086SZhenguo Yao break; 4214b5389086SZhenguo Yao } 4215b5389086SZhenguo Yao } 4216a3437870SNishanth Aravamudan 42178faa8b07SAndi Kleen /* 42188faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 421904adbc3fSMiaohe Lin * But we need to allocate gigantic hstates here early to still 42208faa8b07SAndi Kleen * use the bootmem allocator. 42218faa8b07SAndi Kleen */ 422204adbc3fSMiaohe Lin if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate)) 42238faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 42248faa8b07SAndi Kleen 42258faa8b07SAndi Kleen last_mhp = mhp; 42268faa8b07SAndi Kleen 4227a3437870SNishanth Aravamudan return 1; 4228b5389086SZhenguo Yao 4229b5389086SZhenguo Yao invalid: 4230b5389086SZhenguo Yao pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p); 4231f87442f4SPeng Liu hugepages_clear_pages_in_node(); 4232f81f6e4bSPeng Liu return 1; 4233a3437870SNishanth Aravamudan } 4234282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 4235e11bfbfcSNick Piggin 4236282f4214SMike Kravetz /* 4237282f4214SMike Kravetz * hugepagesz command line processing 4238282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 4239282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 4240282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 4241282f4214SMike Kravetz * hugepagesz argument was valid. 4242282f4214SMike Kravetz */ 4243359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 4244e11bfbfcSNick Piggin { 4245359f2544SMike Kravetz unsigned long size; 4246282f4214SMike Kravetz struct hstate *h; 4247282f4214SMike Kravetz 4248282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4249359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 4250359f2544SMike Kravetz 4251359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4252282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 4253f81f6e4bSPeng Liu return 1; 4254359f2544SMike Kravetz } 4255359f2544SMike Kravetz 4256282f4214SMike Kravetz h = size_to_hstate(size); 4257282f4214SMike Kravetz if (h) { 4258282f4214SMike Kravetz /* 4259282f4214SMike Kravetz * hstate for this size already exists. This is normally 4260282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 4261282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 4262282f4214SMike Kravetz * the number of huge pages for the default hstate was not 4263282f4214SMike Kravetz * previously specified. 4264282f4214SMike Kravetz */ 4265282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 4266282f4214SMike Kravetz default_hstate.max_huge_pages) { 4267282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 4268f81f6e4bSPeng Liu return 1; 426938237830SMike Kravetz } 427038237830SMike Kravetz 4271282f4214SMike Kravetz /* 4272282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 4273282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 4274282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 4275282f4214SMike Kravetz */ 4276282f4214SMike Kravetz parsed_hstate = h; 4277282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4278e11bfbfcSNick Piggin return 1; 4279e11bfbfcSNick Piggin } 4280282f4214SMike Kravetz 4281359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4282282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4283359f2544SMike Kravetz return 1; 4284359f2544SMike Kravetz } 4285359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 4286359f2544SMike Kravetz 4287282f4214SMike Kravetz /* 4288282f4214SMike Kravetz * default_hugepagesz command line input 4289282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 4290282f4214SMike Kravetz */ 4291ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 4292e11bfbfcSNick Piggin { 4293ae94da89SMike Kravetz unsigned long size; 4294b5389086SZhenguo Yao int i; 4295ae94da89SMike Kravetz 4296282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4297282f4214SMike Kravetz if (parsed_default_hugepagesz) { 4298282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 4299f81f6e4bSPeng Liu return 1; 4300282f4214SMike Kravetz } 4301282f4214SMike Kravetz 4302282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 4303282f4214SMike Kravetz 4304282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4305282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 4306f81f6e4bSPeng Liu return 1; 4307282f4214SMike Kravetz } 4308282f4214SMike Kravetz 4309282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4310282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4311282f4214SMike Kravetz parsed_default_hugepagesz = true; 4312282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 4313282f4214SMike Kravetz 4314282f4214SMike Kravetz /* 4315282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 4316282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 4317282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 4318282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 4319282f4214SMike Kravetz * allocated here from bootmem allocator. 4320282f4214SMike Kravetz */ 4321282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 4322282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 43230a7a0f6fSPeng Liu for_each_online_node(i) 4324b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4325b5389086SZhenguo Yao default_hugepages_in_node[i]; 4326282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 4327282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 4328282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 4329282f4214SMike Kravetz } 4330282f4214SMike Kravetz 4331e11bfbfcSNick Piggin return 1; 4332e11bfbfcSNick Piggin } 4333ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 4334a3437870SNishanth Aravamudan 43358ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 43368a213460SNishanth Aravamudan { 43378a213460SNishanth Aravamudan int node; 43388a213460SNishanth Aravamudan unsigned int nr = 0; 43398ca39e68SMuchun Song nodemask_t *mpol_allowed; 43408ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 43418ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 43428a213460SNishanth Aravamudan 43438ca39e68SMuchun Song mpol_allowed = policy_nodemask_current(gfp_mask); 43448ca39e68SMuchun Song 43458ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 4346c93b0a99SJiapeng Zhong if (!mpol_allowed || node_isset(node, *mpol_allowed)) 43478a213460SNishanth Aravamudan nr += array[node]; 43488ca39e68SMuchun Song } 43498a213460SNishanth Aravamudan 43508a213460SNishanth Aravamudan return nr; 43518a213460SNishanth Aravamudan } 43528a213460SNishanth Aravamudan 43538a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 435417743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 435517743798SMuchun Song void *buffer, size_t *length, 435617743798SMuchun Song loff_t *ppos, unsigned long *out) 435717743798SMuchun Song { 435817743798SMuchun Song struct ctl_table dup_table; 435917743798SMuchun Song 436017743798SMuchun Song /* 436117743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 436217743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 436317743798SMuchun Song */ 436417743798SMuchun Song dup_table = *table; 436517743798SMuchun Song dup_table.data = out; 436617743798SMuchun Song 436717743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 436817743798SMuchun Song } 436917743798SMuchun Song 437006808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 437106808b08SLee Schermerhorn struct ctl_table *table, int write, 437232927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 43731da177e4SLinus Torvalds { 4374e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 4375238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 437608d4a246SMichal Hocko int ret; 4377e5ff2159SAndi Kleen 4378457c1b27SNishanth Aravamudan if (!hugepages_supported()) 437986613628SJan Stancek return -EOPNOTSUPP; 4380457c1b27SNishanth Aravamudan 438117743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 438217743798SMuchun Song &tmp); 438308d4a246SMichal Hocko if (ret) 438408d4a246SMichal Hocko goto out; 4385e5ff2159SAndi Kleen 4386238d3c13SDavid Rientjes if (write) 4387238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 4388238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 438908d4a246SMichal Hocko out: 439008d4a246SMichal Hocko return ret; 43911da177e4SLinus Torvalds } 4392396faf03SMel Gorman 439306808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 439432927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 439506808b08SLee Schermerhorn { 439606808b08SLee Schermerhorn 439706808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 439806808b08SLee Schermerhorn buffer, length, ppos); 439906808b08SLee Schermerhorn } 440006808b08SLee Schermerhorn 440106808b08SLee Schermerhorn #ifdef CONFIG_NUMA 440206808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 440332927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 440406808b08SLee Schermerhorn { 440506808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 440606808b08SLee Schermerhorn buffer, length, ppos); 440706808b08SLee Schermerhorn } 440806808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 440906808b08SLee Schermerhorn 4410a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 441132927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 4412a3d0c6aaSNishanth Aravamudan { 4413a5516438SAndi Kleen struct hstate *h = &default_hstate; 4414e5ff2159SAndi Kleen unsigned long tmp; 441508d4a246SMichal Hocko int ret; 4416e5ff2159SAndi Kleen 4417457c1b27SNishanth Aravamudan if (!hugepages_supported()) 441886613628SJan Stancek return -EOPNOTSUPP; 4419457c1b27SNishanth Aravamudan 4420e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 4421e5ff2159SAndi Kleen 4422bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 4423adbe8726SEric B Munson return -EINVAL; 4424adbe8726SEric B Munson 442517743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 442617743798SMuchun Song &tmp); 442708d4a246SMichal Hocko if (ret) 442808d4a246SMichal Hocko goto out; 4429e5ff2159SAndi Kleen 4430e5ff2159SAndi Kleen if (write) { 4431db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4432e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 4433db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4434e5ff2159SAndi Kleen } 443508d4a246SMichal Hocko out: 443608d4a246SMichal Hocko return ret; 4437a3d0c6aaSNishanth Aravamudan } 4438a3d0c6aaSNishanth Aravamudan 44391da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 44401da177e4SLinus Torvalds 4441e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 44421da177e4SLinus Torvalds { 4443fcb2b0c5SRoman Gushchin struct hstate *h; 4444fcb2b0c5SRoman Gushchin unsigned long total = 0; 4445fcb2b0c5SRoman Gushchin 4446457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4447457c1b27SNishanth Aravamudan return; 4448fcb2b0c5SRoman Gushchin 4449fcb2b0c5SRoman Gushchin for_each_hstate(h) { 4450fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 4451fcb2b0c5SRoman Gushchin 4452aca78307SMiaohe Lin total += huge_page_size(h) * count; 4453fcb2b0c5SRoman Gushchin 4454fcb2b0c5SRoman Gushchin if (h == &default_hstate) 4455e1759c21SAlexey Dobriyan seq_printf(m, 44561da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 44571da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 4458b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 44597893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 44604f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 4461fcb2b0c5SRoman Gushchin count, 4462a5516438SAndi Kleen h->free_huge_pages, 4463a5516438SAndi Kleen h->resv_huge_pages, 4464a5516438SAndi Kleen h->surplus_huge_pages, 4465aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4466fcb2b0c5SRoman Gushchin } 4467fcb2b0c5SRoman Gushchin 4468aca78307SMiaohe Lin seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K); 44691da177e4SLinus Torvalds } 44701da177e4SLinus Torvalds 44717981593bSJoe Perches int hugetlb_report_node_meminfo(char *buf, int len, int nid) 44721da177e4SLinus Torvalds { 4473a5516438SAndi Kleen struct hstate *h = &default_hstate; 44747981593bSJoe Perches 4475457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4476457c1b27SNishanth Aravamudan return 0; 44777981593bSJoe Perches 44787981593bSJoe Perches return sysfs_emit_at(buf, len, 44791da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 4480a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 4481a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 4482a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 4483a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 4484a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 44851da177e4SLinus Torvalds } 44861da177e4SLinus Torvalds 4487dcadcf1cSGang Li void hugetlb_show_meminfo_node(int nid) 4488949f7ec5SDavid Rientjes { 4489949f7ec5SDavid Rientjes struct hstate *h; 4490949f7ec5SDavid Rientjes 4491457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4492457c1b27SNishanth Aravamudan return; 4493457c1b27SNishanth Aravamudan 4494949f7ec5SDavid Rientjes for_each_hstate(h) 4495dcadcf1cSGang Li printk("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 4496949f7ec5SDavid Rientjes nid, 4497949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 4498949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 4499949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 4500aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4501949f7ec5SDavid Rientjes } 4502949f7ec5SDavid Rientjes 45035d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 45045d317b2bSNaoya Horiguchi { 45055d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 45065d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 45075d317b2bSNaoya Horiguchi } 45085d317b2bSNaoya Horiguchi 45091da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 45101da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 45111da177e4SLinus Torvalds { 4512d0028588SWanpeng Li struct hstate *h; 4513d0028588SWanpeng Li unsigned long nr_total_pages = 0; 4514d0028588SWanpeng Li 4515d0028588SWanpeng Li for_each_hstate(h) 4516d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 4517d0028588SWanpeng Li return nr_total_pages; 45181da177e4SLinus Torvalds } 45191da177e4SLinus Torvalds 4520a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 4521fc1b8a73SMel Gorman { 4522fc1b8a73SMel Gorman int ret = -ENOMEM; 4523fc1b8a73SMel Gorman 45240aa7f354SMiaohe Lin if (!delta) 45250aa7f354SMiaohe Lin return 0; 45260aa7f354SMiaohe Lin 4527db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4528fc1b8a73SMel Gorman /* 4529fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 4530fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 4531fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 4532fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 4533fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 4534fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 4535fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 4536fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 4537fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 4538fc1b8a73SMel Gorman * 4539fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 4540fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 4541fc1b8a73SMel Gorman * we fall back to check against current free page availability as 4542fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 4543fc1b8a73SMel Gorman * semantics that cpuset has. 45448ca39e68SMuchun Song * 45458ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 45468ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 45478ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 45488ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 45498ca39e68SMuchun Song * above. 4550fc1b8a73SMel Gorman */ 4551fc1b8a73SMel Gorman if (delta > 0) { 4552a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 4553fc1b8a73SMel Gorman goto out; 4554fc1b8a73SMel Gorman 45558ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 4556a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 4557fc1b8a73SMel Gorman goto out; 4558fc1b8a73SMel Gorman } 4559fc1b8a73SMel Gorman } 4560fc1b8a73SMel Gorman 4561fc1b8a73SMel Gorman ret = 0; 4562fc1b8a73SMel Gorman if (delta < 0) 4563a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 4564fc1b8a73SMel Gorman 4565fc1b8a73SMel Gorman out: 4566db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4567fc1b8a73SMel Gorman return ret; 4568fc1b8a73SMel Gorman } 4569fc1b8a73SMel Gorman 457084afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 457184afd99bSAndy Whitcroft { 4572f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 457384afd99bSAndy Whitcroft 457484afd99bSAndy Whitcroft /* 457584afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 457684afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 457784afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 457825985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 457984afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 458084afd99bSAndy Whitcroft * new reference here without additional locking. 458184afd99bSAndy Whitcroft */ 458209a26e83SMike Kravetz if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 458309a26e83SMike Kravetz resv_map_dup_hugetlb_cgroup_uncharge_info(resv); 4584f522c3acSJoonsoo Kim kref_get(&resv->refs); 458584afd99bSAndy Whitcroft } 458609a26e83SMike Kravetz } 458784afd99bSAndy Whitcroft 4588a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 4589a1e78772SMel Gorman { 4590a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4591f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 459290481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 45934e35f483SJoonsoo Kim unsigned long reserve, start, end; 45941c5ecae3SMike Kravetz long gbl_reserve; 459584afd99bSAndy Whitcroft 45964e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 45974e35f483SJoonsoo Kim return; 45984e35f483SJoonsoo Kim 4599a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 4600a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 460184afd99bSAndy Whitcroft 46024e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 4603e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 46047251ff78SAdam Litke if (reserve) { 46051c5ecae3SMike Kravetz /* 46061c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 46071c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 46081c5ecae3SMike Kravetz */ 46091c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 46101c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 46117251ff78SAdam Litke } 4612e9fe92aeSMina Almasry 4613e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 4614a1e78772SMel Gorman } 4615a1e78772SMel Gorman 461631383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 461731383c68SDan Williams { 461831383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 461931383c68SDan Williams return -EINVAL; 462031383c68SDan Williams return 0; 462131383c68SDan Williams } 462231383c68SDan Williams 462305ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 462405ea8860SDan Williams { 4625aca78307SMiaohe Lin return huge_page_size(hstate_vma(vma)); 462605ea8860SDan Williams } 462705ea8860SDan Williams 46281da177e4SLinus Torvalds /* 46291da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 46301da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 46316c26d310SMiaohe Lin * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get 46321da177e4SLinus Torvalds * this far. 46331da177e4SLinus Torvalds */ 4634b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 46351da177e4SLinus Torvalds { 46361da177e4SLinus Torvalds BUG(); 4637d0217ac0SNick Piggin return 0; 46381da177e4SLinus Torvalds } 46391da177e4SLinus Torvalds 4640eec3636aSJane Chu /* 4641eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 4642eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 4643eec3636aSJane Chu * This is because under System V memory model, mappings created via 4644eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 4645eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 4646eec3636aSJane Chu */ 4647f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 4648d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 464984afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 4650a1e78772SMel Gorman .close = hugetlb_vm_op_close, 4651dd3b614fSDmitry Safonov .may_split = hugetlb_vm_op_split, 465205ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 46531da177e4SLinus Torvalds }; 46541da177e4SLinus Torvalds 46551e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 46561e8f889bSDavid Gibson int writable) 465763551ae0SDavid Gibson { 465863551ae0SDavid Gibson pte_t entry; 465979c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 466063551ae0SDavid Gibson 46611e8f889bSDavid Gibson if (writable) { 4662106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 4663106c992aSGerald Schaefer vma->vm_page_prot))); 466463551ae0SDavid Gibson } else { 4665106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 4666106c992aSGerald Schaefer vma->vm_page_prot)); 466763551ae0SDavid Gibson } 466863551ae0SDavid Gibson entry = pte_mkyoung(entry); 466979c1c594SChristophe Leroy entry = arch_make_huge_pte(entry, shift, vma->vm_flags); 467063551ae0SDavid Gibson 467163551ae0SDavid Gibson return entry; 467263551ae0SDavid Gibson } 467363551ae0SDavid Gibson 46741e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 46751e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 46761e8f889bSDavid Gibson { 46771e8f889bSDavid Gibson pte_t entry; 46781e8f889bSDavid Gibson 4679106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 468032f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 46814b3073e1SRussell King update_mmu_cache(vma, address, ptep); 46821e8f889bSDavid Gibson } 46831e8f889bSDavid Gibson 4684d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 46854a705fefSNaoya Horiguchi { 46864a705fefSNaoya Horiguchi swp_entry_t swp; 46874a705fefSNaoya Horiguchi 46884a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 4689d5ed7444SAneesh Kumar K.V return false; 46904a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4691d79d176aSBaoquan He if (is_migration_entry(swp)) 4692d5ed7444SAneesh Kumar K.V return true; 46934a705fefSNaoya Horiguchi else 4694d5ed7444SAneesh Kumar K.V return false; 46954a705fefSNaoya Horiguchi } 46964a705fefSNaoya Horiguchi 46973e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 46984a705fefSNaoya Horiguchi { 46994a705fefSNaoya Horiguchi swp_entry_t swp; 47004a705fefSNaoya Horiguchi 47014a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 47023e5c3600SBaoquan He return false; 47034a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4704d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 47053e5c3600SBaoquan He return true; 47064a705fefSNaoya Horiguchi else 47073e5c3600SBaoquan He return false; 47084a705fefSNaoya Horiguchi } 47091e8f889bSDavid Gibson 47104eae4efaSPeter Xu static void 47114eae4efaSPeter Xu hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr, 47124eae4efaSPeter Xu struct page *new_page) 47134eae4efaSPeter Xu { 47144eae4efaSPeter Xu __SetPageUptodate(new_page); 47154eae4efaSPeter Xu hugepage_add_new_anon_rmap(new_page, vma, addr); 47161eba86c0SPasha Tatashin set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1)); 47174eae4efaSPeter Xu hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm); 47184eae4efaSPeter Xu ClearHPageRestoreReserve(new_page); 47194eae4efaSPeter Xu SetHPageMigratable(new_page); 47204eae4efaSPeter Xu } 47214eae4efaSPeter Xu 472263551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 4723bc70fbf2SPeter Xu struct vm_area_struct *dst_vma, 4724bc70fbf2SPeter Xu struct vm_area_struct *src_vma) 472563551ae0SDavid Gibson { 47265e41540cSMike Kravetz pte_t *src_pte, *dst_pte, entry, dst_entry; 472763551ae0SDavid Gibson struct page *ptepage; 47281c59827dSHugh Dickins unsigned long addr; 4729bc70fbf2SPeter Xu bool cow = is_cow_mapping(src_vma->vm_flags); 4730bc70fbf2SPeter Xu struct hstate *h = hstate_vma(src_vma); 4731a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 47324eae4efaSPeter Xu unsigned long npages = pages_per_huge_page(h); 4733bc70fbf2SPeter Xu struct address_space *mapping = src_vma->vm_file->f_mapping; 4734ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4735e95a9851SMike Kravetz unsigned long last_addr_mask; 4736e8569dd2SAndreas Sandberg int ret = 0; 47371e8f889bSDavid Gibson 4738ac46d4f3SJérôme Glisse if (cow) { 4739bc70fbf2SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, src_vma, src, 4740bc70fbf2SPeter Xu src_vma->vm_start, 4741bc70fbf2SPeter Xu src_vma->vm_end); 4742ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4743623a1ddfSDavid Hildenbrand mmap_assert_write_locked(src); 4744623a1ddfSDavid Hildenbrand raw_write_seqcount_begin(&src->write_protect_seq); 4745c0d0381aSMike Kravetz } else { 4746c0d0381aSMike Kravetz /* 4747c0d0381aSMike Kravetz * For shared mappings i_mmap_rwsem must be held to call 4748c0d0381aSMike Kravetz * huge_pte_alloc, otherwise the returned ptep could go 4749c0d0381aSMike Kravetz * away if part of a shared pmd and another thread calls 4750c0d0381aSMike Kravetz * huge_pmd_unshare. 4751c0d0381aSMike Kravetz */ 4752c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 4753ac46d4f3SJérôme Glisse } 4754e8569dd2SAndreas Sandberg 4755e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 4756bc70fbf2SPeter Xu for (addr = src_vma->vm_start; addr < src_vma->vm_end; addr += sz) { 4757cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 47587868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 4759e95a9851SMike Kravetz if (!src_pte) { 4760e95a9851SMike Kravetz addr |= last_addr_mask; 4761c74df32cSHugh Dickins continue; 4762e95a9851SMike Kravetz } 4763bc70fbf2SPeter Xu dst_pte = huge_pte_alloc(dst, dst_vma, addr, sz); 4764e8569dd2SAndreas Sandberg if (!dst_pte) { 4765e8569dd2SAndreas Sandberg ret = -ENOMEM; 4766e8569dd2SAndreas Sandberg break; 4767e8569dd2SAndreas Sandberg } 4768c5c99429SLarry Woodman 47695e41540cSMike Kravetz /* 47705e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 47715e41540cSMike Kravetz * dst_pte == src_pte is the common case of src/dest sharing. 47725e41540cSMike Kravetz * 47735e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 47745e41540cSMike Kravetz * another vma. If dst_pte !none, this implies sharing. 47755e41540cSMike Kravetz * Check here before taking page table lock, and once again 47765e41540cSMike Kravetz * after taking the lock below. 47775e41540cSMike Kravetz */ 47785e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 4779e95a9851SMike Kravetz if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) { 4780e95a9851SMike Kravetz addr |= last_addr_mask; 4781c5c99429SLarry Woodman continue; 4782e95a9851SMike Kravetz } 4783c5c99429SLarry Woodman 4784cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 4785cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 4786cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 47874a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 47885e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 47894eae4efaSPeter Xu again: 47905e41540cSMike Kravetz if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { 47915e41540cSMike Kravetz /* 47925e41540cSMike Kravetz * Skip if src entry none. Also, skip in the 47935e41540cSMike Kravetz * unlikely case dst entry !none as this implies 47945e41540cSMike Kravetz * sharing with another vma. 47955e41540cSMike Kravetz */ 47964a705fefSNaoya Horiguchi ; 4797c2cb0dccSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) { 4798c2cb0dccSNaoya Horiguchi bool uffd_wp = huge_pte_uffd_wp(entry); 4799c2cb0dccSNaoya Horiguchi 4800c2cb0dccSNaoya Horiguchi if (!userfaultfd_wp(dst_vma) && uffd_wp) 4801c2cb0dccSNaoya Horiguchi entry = huge_pte_clear_uffd_wp(entry); 4802c2cb0dccSNaoya Horiguchi set_huge_pte_at(dst, addr, dst_pte, entry); 4803c2cb0dccSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry))) { 48044a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 4805bc70fbf2SPeter Xu bool uffd_wp = huge_pte_uffd_wp(entry); 48064a705fefSNaoya Horiguchi 48076c287605SDavid Hildenbrand if (!is_readable_migration_entry(swp_entry) && cow) { 48084a705fefSNaoya Horiguchi /* 48094a705fefSNaoya Horiguchi * COW mappings require pages in both 48104a705fefSNaoya Horiguchi * parent and child to be set to read. 48114a705fefSNaoya Horiguchi */ 48124dd845b5SAlistair Popple swp_entry = make_readable_migration_entry( 48134dd845b5SAlistair Popple swp_offset(swp_entry)); 48144a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 4815bc70fbf2SPeter Xu if (userfaultfd_wp(src_vma) && uffd_wp) 4816bc70fbf2SPeter Xu entry = huge_pte_mkuffd_wp(entry); 481718f39629SQi Zheng set_huge_pte_at(src, addr, src_pte, entry); 48184a705fefSNaoya Horiguchi } 4819bc70fbf2SPeter Xu if (!userfaultfd_wp(dst_vma) && uffd_wp) 4820bc70fbf2SPeter Xu entry = huge_pte_clear_uffd_wp(entry); 482118f39629SQi Zheng set_huge_pte_at(dst, addr, dst_pte, entry); 4822bc70fbf2SPeter Xu } else if (unlikely(is_pte_marker(entry))) { 4823bc70fbf2SPeter Xu /* 4824bc70fbf2SPeter Xu * We copy the pte marker only if the dst vma has 4825bc70fbf2SPeter Xu * uffd-wp enabled. 4826bc70fbf2SPeter Xu */ 4827bc70fbf2SPeter Xu if (userfaultfd_wp(dst_vma)) 4828bc70fbf2SPeter Xu set_huge_pte_at(dst, addr, dst_pte, entry); 48294a705fefSNaoya Horiguchi } else { 48304eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48314eae4efaSPeter Xu ptepage = pte_page(entry); 48324eae4efaSPeter Xu get_page(ptepage); 48334eae4efaSPeter Xu 48344eae4efaSPeter Xu /* 4835fb3d824dSDavid Hildenbrand * Failing to duplicate the anon rmap is a rare case 4836fb3d824dSDavid Hildenbrand * where we see pinned hugetlb pages while they're 4837fb3d824dSDavid Hildenbrand * prone to COW. We need to do the COW earlier during 4838fb3d824dSDavid Hildenbrand * fork. 48394eae4efaSPeter Xu * 48404eae4efaSPeter Xu * When pre-allocating the page or copying data, we 48414eae4efaSPeter Xu * need to be without the pgtable locks since we could 48424eae4efaSPeter Xu * sleep during the process. 48434eae4efaSPeter Xu */ 4844fb3d824dSDavid Hildenbrand if (!PageAnon(ptepage)) { 4845fb3d824dSDavid Hildenbrand page_dup_file_rmap(ptepage, true); 4846bc70fbf2SPeter Xu } else if (page_try_dup_anon_rmap(ptepage, true, 4847bc70fbf2SPeter Xu src_vma)) { 48484eae4efaSPeter Xu pte_t src_pte_old = entry; 48494eae4efaSPeter Xu struct page *new; 48504eae4efaSPeter Xu 48514eae4efaSPeter Xu spin_unlock(src_ptl); 48524eae4efaSPeter Xu spin_unlock(dst_ptl); 48534eae4efaSPeter Xu /* Do not use reserve as it's private owned */ 4854bc70fbf2SPeter Xu new = alloc_huge_page(dst_vma, addr, 1); 48554eae4efaSPeter Xu if (IS_ERR(new)) { 48564eae4efaSPeter Xu put_page(ptepage); 48574eae4efaSPeter Xu ret = PTR_ERR(new); 48584eae4efaSPeter Xu break; 48594eae4efaSPeter Xu } 4860bc70fbf2SPeter Xu copy_user_huge_page(new, ptepage, addr, dst_vma, 48614eae4efaSPeter Xu npages); 48624eae4efaSPeter Xu put_page(ptepage); 48634eae4efaSPeter Xu 48644eae4efaSPeter Xu /* Install the new huge page if src pte stable */ 48654eae4efaSPeter Xu dst_ptl = huge_pte_lock(h, dst, dst_pte); 48664eae4efaSPeter Xu src_ptl = huge_pte_lockptr(h, src, src_pte); 48674eae4efaSPeter Xu spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 48684eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48694eae4efaSPeter Xu if (!pte_same(src_pte_old, entry)) { 4870bc70fbf2SPeter Xu restore_reserve_on_error(h, dst_vma, addr, 4871846be085SMike Kravetz new); 48724eae4efaSPeter Xu put_page(new); 48734eae4efaSPeter Xu /* dst_entry won't change as in child */ 48744eae4efaSPeter Xu goto again; 48754eae4efaSPeter Xu } 4876bc70fbf2SPeter Xu hugetlb_install_page(dst_vma, dst_pte, addr, new); 48774eae4efaSPeter Xu spin_unlock(src_ptl); 48784eae4efaSPeter Xu spin_unlock(dst_ptl); 48794eae4efaSPeter Xu continue; 48804eae4efaSPeter Xu } 48814eae4efaSPeter Xu 488234ee645eSJoerg Roedel if (cow) { 48830f10851eSJérôme Glisse /* 48840f10851eSJérôme Glisse * No need to notify as we are downgrading page 48850f10851eSJérôme Glisse * table protection not changing it to point 48860f10851eSJérôme Glisse * to a new page. 48870f10851eSJérôme Glisse * 4888ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 48890f10851eSJérôme Glisse */ 48907f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 489184894e1cSPeter Xu entry = huge_pte_wrprotect(entry); 489234ee645eSJoerg Roedel } 48934eae4efaSPeter Xu 489463551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 48954eae4efaSPeter Xu hugetlb_count_add(npages, dst); 48961c59827dSHugh Dickins } 4897cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 4898cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 489963551ae0SDavid Gibson } 490063551ae0SDavid Gibson 4901623a1ddfSDavid Hildenbrand if (cow) { 4902623a1ddfSDavid Hildenbrand raw_write_seqcount_end(&src->write_protect_seq); 4903ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4904623a1ddfSDavid Hildenbrand } else { 4905c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 4906623a1ddfSDavid Hildenbrand } 4907e8569dd2SAndreas Sandberg 4908e8569dd2SAndreas Sandberg return ret; 490963551ae0SDavid Gibson } 491063551ae0SDavid Gibson 4911550a7d60SMina Almasry static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr, 4912db110a99SAneesh Kumar K.V unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte) 4913550a7d60SMina Almasry { 4914550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4915550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4916550a7d60SMina Almasry spinlock_t *src_ptl, *dst_ptl; 4917db110a99SAneesh Kumar K.V pte_t pte; 4918550a7d60SMina Almasry 4919550a7d60SMina Almasry dst_ptl = huge_pte_lock(h, mm, dst_pte); 4920550a7d60SMina Almasry src_ptl = huge_pte_lockptr(h, mm, src_pte); 4921550a7d60SMina Almasry 4922550a7d60SMina Almasry /* 4923550a7d60SMina Almasry * We don't have to worry about the ordering of src and dst ptlocks 4924550a7d60SMina Almasry * because exclusive mmap_sem (or the i_mmap_lock) prevents deadlock. 4925550a7d60SMina Almasry */ 4926550a7d60SMina Almasry if (src_ptl != dst_ptl) 4927550a7d60SMina Almasry spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 4928550a7d60SMina Almasry 4929550a7d60SMina Almasry pte = huge_ptep_get_and_clear(mm, old_addr, src_pte); 4930550a7d60SMina Almasry set_huge_pte_at(mm, new_addr, dst_pte, pte); 4931550a7d60SMina Almasry 4932550a7d60SMina Almasry if (src_ptl != dst_ptl) 4933550a7d60SMina Almasry spin_unlock(src_ptl); 4934550a7d60SMina Almasry spin_unlock(dst_ptl); 4935550a7d60SMina Almasry } 4936550a7d60SMina Almasry 4937550a7d60SMina Almasry int move_hugetlb_page_tables(struct vm_area_struct *vma, 4938550a7d60SMina Almasry struct vm_area_struct *new_vma, 4939550a7d60SMina Almasry unsigned long old_addr, unsigned long new_addr, 4940550a7d60SMina Almasry unsigned long len) 4941550a7d60SMina Almasry { 4942550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4943550a7d60SMina Almasry struct address_space *mapping = vma->vm_file->f_mapping; 4944550a7d60SMina Almasry unsigned long sz = huge_page_size(h); 4945550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4946550a7d60SMina Almasry unsigned long old_end = old_addr + len; 4947e95a9851SMike Kravetz unsigned long last_addr_mask; 4948550a7d60SMina Almasry pte_t *src_pte, *dst_pte; 4949550a7d60SMina Almasry struct mmu_notifier_range range; 49503d0b95cdSBaolin Wang bool shared_pmd = false; 4951550a7d60SMina Almasry 4952550a7d60SMina Almasry mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, old_addr, 4953550a7d60SMina Almasry old_end); 4954550a7d60SMina Almasry adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 49553d0b95cdSBaolin Wang /* 49563d0b95cdSBaolin Wang * In case of shared PMDs, we should cover the maximum possible 49573d0b95cdSBaolin Wang * range. 49583d0b95cdSBaolin Wang */ 49593d0b95cdSBaolin Wang flush_cache_range(vma, range.start, range.end); 49603d0b95cdSBaolin Wang 4961550a7d60SMina Almasry mmu_notifier_invalidate_range_start(&range); 4962e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 4963550a7d60SMina Almasry /* Prevent race with file truncation */ 4964550a7d60SMina Almasry i_mmap_lock_write(mapping); 4965550a7d60SMina Almasry for (; old_addr < old_end; old_addr += sz, new_addr += sz) { 4966550a7d60SMina Almasry src_pte = huge_pte_offset(mm, old_addr, sz); 4967e95a9851SMike Kravetz if (!src_pte) { 4968e95a9851SMike Kravetz old_addr |= last_addr_mask; 4969e95a9851SMike Kravetz new_addr |= last_addr_mask; 4970550a7d60SMina Almasry continue; 4971e95a9851SMike Kravetz } 4972550a7d60SMina Almasry if (huge_pte_none(huge_ptep_get(src_pte))) 4973550a7d60SMina Almasry continue; 4974550a7d60SMina Almasry 49754ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) { 49763d0b95cdSBaolin Wang shared_pmd = true; 49774ddb4d91SMike Kravetz old_addr |= last_addr_mask; 49784ddb4d91SMike Kravetz new_addr |= last_addr_mask; 4979550a7d60SMina Almasry continue; 49803d0b95cdSBaolin Wang } 4981550a7d60SMina Almasry 4982550a7d60SMina Almasry dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz); 4983550a7d60SMina Almasry if (!dst_pte) 4984550a7d60SMina Almasry break; 4985550a7d60SMina Almasry 4986db110a99SAneesh Kumar K.V move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte); 4987550a7d60SMina Almasry } 49883d0b95cdSBaolin Wang 49893d0b95cdSBaolin Wang if (shared_pmd) 49903d0b95cdSBaolin Wang flush_tlb_range(vma, range.start, range.end); 49913d0b95cdSBaolin Wang else 4992550a7d60SMina Almasry flush_tlb_range(vma, old_end - len, old_end); 4993550a7d60SMina Almasry mmu_notifier_invalidate_range_end(&range); 499413e4ad2cSNadav Amit i_mmap_unlock_write(mapping); 4995550a7d60SMina Almasry 4996550a7d60SMina Almasry return len + old_addr - old_end; 4997550a7d60SMina Almasry } 4998550a7d60SMina Almasry 499973c54763SPeter Xu static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 500024669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 500105e90bd0SPeter Xu struct page *ref_page, zap_flags_t zap_flags) 500263551ae0SDavid Gibson { 500363551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 500463551ae0SDavid Gibson unsigned long address; 5005c7546f8fSDavid Gibson pte_t *ptep; 500663551ae0SDavid Gibson pte_t pte; 5007cb900f41SKirill A. Shutemov spinlock_t *ptl; 500863551ae0SDavid Gibson struct page *page; 5009a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 5010a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 5011ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 5012e95a9851SMike Kravetz unsigned long last_addr_mask; 5013a4a118f2SNadav Amit bool force_flush = false; 5014a5516438SAndi Kleen 501563551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 5016a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 5017a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 501863551ae0SDavid Gibson 501907e32661SAneesh Kumar K.V /* 502007e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 502107e32661SAneesh Kumar K.V * to huge page. 502207e32661SAneesh Kumar K.V */ 5023ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 502424669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 5025dff11abeSMike Kravetz 5026dff11abeSMike Kravetz /* 5027dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 5028dff11abeSMike Kravetz */ 50296f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 50306f4f13e8SJérôme Glisse end); 5031ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 5032ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5033e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 5034569f48b8SHillf Danton address = start; 5035569f48b8SHillf Danton for (; address < end; address += sz) { 50367868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 5037e95a9851SMike Kravetz if (!ptep) { 5038e95a9851SMike Kravetz address |= last_addr_mask; 5039c7546f8fSDavid Gibson continue; 5040e95a9851SMike Kravetz } 5041c7546f8fSDavid Gibson 5042cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 50434ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, address, ptep)) { 504431d49da5SAneesh Kumar K.V spin_unlock(ptl); 5045a4a118f2SNadav Amit tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); 5046a4a118f2SNadav Amit force_flush = true; 50474ddb4d91SMike Kravetz address |= last_addr_mask; 504831d49da5SAneesh Kumar K.V continue; 504931d49da5SAneesh Kumar K.V } 505039dde65cSChen, Kenneth W 50516629326bSHillf Danton pte = huge_ptep_get(ptep); 505231d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 505331d49da5SAneesh Kumar K.V spin_unlock(ptl); 505431d49da5SAneesh Kumar K.V continue; 505531d49da5SAneesh Kumar K.V } 50566629326bSHillf Danton 50576629326bSHillf Danton /* 50589fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 50599fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 50606629326bSHillf Danton */ 50619fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 506205e90bd0SPeter Xu /* 506305e90bd0SPeter Xu * If the pte was wr-protected by uffd-wp in any of the 506405e90bd0SPeter Xu * swap forms, meanwhile the caller does not want to 506505e90bd0SPeter Xu * drop the uffd-wp bit in this zap, then replace the 506605e90bd0SPeter Xu * pte with a marker. 506705e90bd0SPeter Xu */ 506805e90bd0SPeter Xu if (pte_swp_uffd_wp_any(pte) && 506905e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 507005e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 507105e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 507205e90bd0SPeter Xu else 50739386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 507431d49da5SAneesh Kumar K.V spin_unlock(ptl); 507531d49da5SAneesh Kumar K.V continue; 50768c4894c6SNaoya Horiguchi } 50776629326bSHillf Danton 50786629326bSHillf Danton page = pte_page(pte); 507904f2cbe3SMel Gorman /* 508004f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 508104f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 508204f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 508304f2cbe3SMel Gorman */ 508404f2cbe3SMel Gorman if (ref_page) { 508531d49da5SAneesh Kumar K.V if (page != ref_page) { 508631d49da5SAneesh Kumar K.V spin_unlock(ptl); 508731d49da5SAneesh Kumar K.V continue; 508831d49da5SAneesh Kumar K.V } 508904f2cbe3SMel Gorman /* 509004f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 509104f2cbe3SMel Gorman * future faults in this VMA will fail rather than 509204f2cbe3SMel Gorman * looking like data was lost 509304f2cbe3SMel Gorman */ 509404f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 509504f2cbe3SMel Gorman } 509604f2cbe3SMel Gorman 5097c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 5098b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 5099106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 51006649a386SKen Chen set_page_dirty(page); 510105e90bd0SPeter Xu /* Leave a uffd-wp pte marker if needed */ 510205e90bd0SPeter Xu if (huge_pte_uffd_wp(pte) && 510305e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 510405e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 510505e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 51065d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 5107cea86fe2SHugh Dickins page_remove_rmap(page, vma, true); 510831d49da5SAneesh Kumar K.V 5109cb900f41SKirill A. Shutemov spin_unlock(ptl); 5110e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 511124669e58SAneesh Kumar K.V /* 511231d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 511324669e58SAneesh Kumar K.V */ 511431d49da5SAneesh Kumar K.V if (ref_page) 511531d49da5SAneesh Kumar K.V break; 5116fe1668aeSChen, Kenneth W } 5117ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 511824669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 5119a4a118f2SNadav Amit 5120a4a118f2SNadav Amit /* 5121a4a118f2SNadav Amit * If we unshared PMDs, the TLB flush was not recorded in mmu_gather. We 5122a4a118f2SNadav Amit * could defer the flush until now, since by holding i_mmap_rwsem we 5123a4a118f2SNadav Amit * guaranteed that the last refernece would not be dropped. But we must 5124a4a118f2SNadav Amit * do the flushing before we return, as otherwise i_mmap_rwsem will be 5125a4a118f2SNadav Amit * dropped and the last reference to the shared PMDs page might be 5126a4a118f2SNadav Amit * dropped as well. 5127a4a118f2SNadav Amit * 5128a4a118f2SNadav Amit * In theory we could defer the freeing of the PMD pages as well, but 5129a4a118f2SNadav Amit * huge_pmd_unshare() relies on the exact page_count for the PMD page to 5130a4a118f2SNadav Amit * detect sharing, so we cannot defer the release of the page either. 5131a4a118f2SNadav Amit * Instead, do flush now. 5132a4a118f2SNadav Amit */ 5133a4a118f2SNadav Amit if (force_flush) 5134a4a118f2SNadav Amit tlb_flush_mmu_tlbonly(tlb); 51351da177e4SLinus Torvalds } 513663551ae0SDavid Gibson 5137d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 5138d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 513905e90bd0SPeter Xu unsigned long end, struct page *ref_page, 514005e90bd0SPeter Xu zap_flags_t zap_flags) 5141d833352aSMel Gorman { 514205e90bd0SPeter Xu __unmap_hugepage_range(tlb, vma, start, end, ref_page, zap_flags); 5143d833352aSMel Gorman 5144d833352aSMel Gorman /* 5145d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 5146d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 5147d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 5148d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 5149d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 5150c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 5151d833352aSMel Gorman * because in the context this is called, the VMA is about to be 5152c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 5153d833352aSMel Gorman */ 5154d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 5155d833352aSMel Gorman } 5156d833352aSMel Gorman 5157502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 515805e90bd0SPeter Xu unsigned long end, struct page *ref_page, 515905e90bd0SPeter Xu zap_flags_t zap_flags) 5160502717f4SChen, Kenneth W { 516124669e58SAneesh Kumar K.V struct mmu_gather tlb; 5162dff11abeSMike Kravetz 5163a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 516405e90bd0SPeter Xu __unmap_hugepage_range(&tlb, vma, start, end, ref_page, zap_flags); 5165ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 5166502717f4SChen, Kenneth W } 5167502717f4SChen, Kenneth W 516804f2cbe3SMel Gorman /* 516904f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 5170578b7725SZhiyuan Dai * mapping it owns the reserve page for. The intention is to unmap the page 517104f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 517204f2cbe3SMel Gorman * same region. 517304f2cbe3SMel Gorman */ 51742f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 51752a4b3dedSHarvey Harrison struct page *page, unsigned long address) 517604f2cbe3SMel Gorman { 51777526674dSAdam Litke struct hstate *h = hstate_vma(vma); 517804f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 517904f2cbe3SMel Gorman struct address_space *mapping; 518004f2cbe3SMel Gorman pgoff_t pgoff; 518104f2cbe3SMel Gorman 518204f2cbe3SMel Gorman /* 518304f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 518404f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 518504f2cbe3SMel Gorman */ 51867526674dSAdam Litke address = address & huge_page_mask(h); 518736e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 518836e4f20aSMichal Hocko vma->vm_pgoff; 518993c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 519004f2cbe3SMel Gorman 51914eb2b1dcSMel Gorman /* 51924eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 51934eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 51944eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 51954eb2b1dcSMel Gorman */ 519683cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 51976b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 519804f2cbe3SMel Gorman /* Do not unmap the current VMA */ 519904f2cbe3SMel Gorman if (iter_vma == vma) 520004f2cbe3SMel Gorman continue; 520104f2cbe3SMel Gorman 520204f2cbe3SMel Gorman /* 52032f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 52042f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 52052f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 52062f84a899SMel Gorman */ 52072f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 52082f84a899SMel Gorman continue; 52092f84a899SMel Gorman 52102f84a899SMel Gorman /* 521104f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 521204f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 521304f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 521404f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 521504f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 521604f2cbe3SMel Gorman */ 521704f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 521824669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 521905e90bd0SPeter Xu address + huge_page_size(h), page, 0); 522004f2cbe3SMel Gorman } 522183cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 522204f2cbe3SMel Gorman } 522304f2cbe3SMel Gorman 52240fe6e20bSNaoya Horiguchi /* 5225c89357e2SDavid Hildenbrand * hugetlb_wp() should be called with page lock of the original hugepage held. 5226aa6d2e8cSBaolin Wang * Called with hugetlb_fault_mutex_table held and pte_page locked so we 5227ef009b25SMichal Hocko * cannot race with other handlers or page migration. 5228ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 52290fe6e20bSNaoya Horiguchi */ 5230c89357e2SDavid Hildenbrand static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, 5231c89357e2SDavid Hildenbrand unsigned long address, pte_t *ptep, unsigned int flags, 5232cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 52331e8f889bSDavid Gibson { 5234c89357e2SDavid Hildenbrand const bool unshare = flags & FAULT_FLAG_UNSHARE; 52353999f52eSAneesh Kumar K.V pte_t pte; 5236a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 52371e8f889bSDavid Gibson struct page *old_page, *new_page; 52382b740303SSouptick Joarder int outside_reserve = 0; 52392b740303SSouptick Joarder vm_fault_t ret = 0; 5240974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 5241ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 52421e8f889bSDavid Gibson 5243c89357e2SDavid Hildenbrand VM_BUG_ON(unshare && (flags & FOLL_WRITE)); 5244c89357e2SDavid Hildenbrand VM_BUG_ON(!unshare && !(flags & FOLL_WRITE)); 5245c89357e2SDavid Hildenbrand 52461d8d1464SDavid Hildenbrand /* 52471d8d1464SDavid Hildenbrand * hugetlb does not support FOLL_FORCE-style write faults that keep the 52481d8d1464SDavid Hildenbrand * PTE mapped R/O such as maybe_mkwrite() would do. 52491d8d1464SDavid Hildenbrand */ 52501d8d1464SDavid Hildenbrand if (WARN_ON_ONCE(!unshare && !(vma->vm_flags & VM_WRITE))) 52511d8d1464SDavid Hildenbrand return VM_FAULT_SIGSEGV; 52521d8d1464SDavid Hildenbrand 52531d8d1464SDavid Hildenbrand /* Let's take out MAP_SHARED mappings first. */ 52541d8d1464SDavid Hildenbrand if (vma->vm_flags & VM_MAYSHARE) { 52551d8d1464SDavid Hildenbrand if (unlikely(unshare)) 52561d8d1464SDavid Hildenbrand return 0; 52571d8d1464SDavid Hildenbrand set_huge_ptep_writable(vma, haddr, ptep); 52581d8d1464SDavid Hildenbrand return 0; 52591d8d1464SDavid Hildenbrand } 52601d8d1464SDavid Hildenbrand 52613999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 52621e8f889bSDavid Gibson old_page = pte_page(pte); 52631e8f889bSDavid Gibson 5264662ce1dcSYang Yang delayacct_wpcopy_start(); 5265662ce1dcSYang Yang 526604f2cbe3SMel Gorman retry_avoidcopy: 5267c89357e2SDavid Hildenbrand /* 5268c89357e2SDavid Hildenbrand * If no-one else is actually using this page, we're the exclusive 5269c89357e2SDavid Hildenbrand * owner and can reuse this page. 5270c89357e2SDavid Hildenbrand */ 527137a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 5272c89357e2SDavid Hildenbrand if (!PageAnonExclusive(old_page)) 52735a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 5274c89357e2SDavid Hildenbrand if (likely(!unshare)) 52755b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 5276662ce1dcSYang Yang 5277662ce1dcSYang Yang delayacct_wpcopy_end(); 527883c54070SNick Piggin return 0; 52791e8f889bSDavid Gibson } 52806c287605SDavid Hildenbrand VM_BUG_ON_PAGE(PageAnon(old_page) && PageAnonExclusive(old_page), 52816c287605SDavid Hildenbrand old_page); 52821e8f889bSDavid Gibson 528304f2cbe3SMel Gorman /* 528404f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 528504f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 528604f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 528704f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 528804f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 528904f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 529004f2cbe3SMel Gorman * of the full address range. 529104f2cbe3SMel Gorman */ 52925944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 529304f2cbe3SMel Gorman old_page != pagecache_page) 529404f2cbe3SMel Gorman outside_reserve = 1; 529504f2cbe3SMel Gorman 529609cbfeafSKirill A. Shutemov get_page(old_page); 5297b76c8cfbSLarry Woodman 5298ad4404a2SDavidlohr Bueso /* 5299ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 5300ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 5301ad4404a2SDavidlohr Bueso */ 5302cb900f41SKirill A. Shutemov spin_unlock(ptl); 53035b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 53041e8f889bSDavid Gibson 53052fc39cecSAdam Litke if (IS_ERR(new_page)) { 530604f2cbe3SMel Gorman /* 530704f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 530804f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 530904f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 531004f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 531104f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 531204f2cbe3SMel Gorman */ 531304f2cbe3SMel Gorman if (outside_reserve) { 5314e7dd91c4SMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 5315e7dd91c4SMike Kravetz pgoff_t idx; 5316e7dd91c4SMike Kravetz u32 hash; 5317e7dd91c4SMike Kravetz 531809cbfeafSKirill A. Shutemov put_page(old_page); 531904f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 5320e7dd91c4SMike Kravetz /* 5321e7dd91c4SMike Kravetz * Drop hugetlb_fault_mutex and i_mmap_rwsem before 5322e7dd91c4SMike Kravetz * unmapping. unmapping needs to hold i_mmap_rwsem 5323e7dd91c4SMike Kravetz * in write mode. Dropping i_mmap_rwsem in read mode 5324e7dd91c4SMike Kravetz * here is OK as COW mappings do not interact with 5325e7dd91c4SMike Kravetz * PMD sharing. 5326e7dd91c4SMike Kravetz * 5327e7dd91c4SMike Kravetz * Reacquire both after unmap operation. 5328e7dd91c4SMike Kravetz */ 5329e7dd91c4SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 5330e7dd91c4SMike Kravetz hash = hugetlb_fault_mutex_hash(mapping, idx); 5331e7dd91c4SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5332e7dd91c4SMike Kravetz i_mmap_unlock_read(mapping); 5333e7dd91c4SMike Kravetz 53345b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 5335e7dd91c4SMike Kravetz 5336e7dd91c4SMike Kravetz i_mmap_lock_read(mapping); 5337e7dd91c4SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 5338cb900f41SKirill A. Shutemov spin_lock(ptl); 53395b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5340a9af0c5dSNaoya Horiguchi if (likely(ptep && 5341a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 534204f2cbe3SMel Gorman goto retry_avoidcopy; 5343a734bcc8SHillf Danton /* 5344cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 5345cb900f41SKirill A. Shutemov * lock, and our job is done. 5346a734bcc8SHillf Danton */ 5347662ce1dcSYang Yang delayacct_wpcopy_end(); 5348a734bcc8SHillf Danton return 0; 534904f2cbe3SMel Gorman } 535004f2cbe3SMel Gorman 53512b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 5352ad4404a2SDavidlohr Bueso goto out_release_old; 53531e8f889bSDavid Gibson } 53541e8f889bSDavid Gibson 53550fe6e20bSNaoya Horiguchi /* 53560fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 53570fe6e20bSNaoya Horiguchi * anon_vma prepared. 53580fe6e20bSNaoya Horiguchi */ 535944e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 5360ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 5361ad4404a2SDavidlohr Bueso goto out_release_all; 536244e2aa93SDean Nelson } 53630fe6e20bSNaoya Horiguchi 5364974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 536547ad8475SAndrea Arcangeli pages_per_huge_page(h)); 53660ed361deSNick Piggin __SetPageUptodate(new_page); 53671e8f889bSDavid Gibson 53687269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 53696f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 5370ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5371ad4404a2SDavidlohr Bueso 5372b76c8cfbSLarry Woodman /* 5373cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 5374b76c8cfbSLarry Woodman * before the page tables are altered 5375b76c8cfbSLarry Woodman */ 5376cb900f41SKirill A. Shutemov spin_lock(ptl); 53775b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5378a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 5379d6995da3SMike Kravetz ClearHPageRestoreReserve(new_page); 538007443a85SJoonsoo Kim 5381c89357e2SDavid Hildenbrand /* Break COW or unshare */ 53825b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 5383ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 5384cea86fe2SHugh Dickins page_remove_rmap(old_page, vma, true); 53855b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 53861eba86c0SPasha Tatashin set_huge_pte_at(mm, haddr, ptep, 5387c89357e2SDavid Hildenbrand make_huge_pte(vma, new_page, !unshare)); 53888f251a3dSMike Kravetz SetHPageMigratable(new_page); 53891e8f889bSDavid Gibson /* Make the old page be freed below */ 53901e8f889bSDavid Gibson new_page = old_page; 53911e8f889bSDavid Gibson } 5392cb900f41SKirill A. Shutemov spin_unlock(ptl); 5393ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 5394ad4404a2SDavidlohr Bueso out_release_all: 5395c89357e2SDavid Hildenbrand /* 5396c89357e2SDavid Hildenbrand * No restore in case of successful pagetable update (Break COW or 5397c89357e2SDavid Hildenbrand * unshare) 5398c89357e2SDavid Hildenbrand */ 5399c7b1850dSMike Kravetz if (new_page != old_page) 54005b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 540109cbfeafSKirill A. Shutemov put_page(new_page); 5402ad4404a2SDavidlohr Bueso out_release_old: 540309cbfeafSKirill A. Shutemov put_page(old_page); 54048312034fSJoonsoo Kim 5405ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 5406662ce1dcSYang Yang 5407662ce1dcSYang Yang delayacct_wpcopy_end(); 5408ad4404a2SDavidlohr Bueso return ret; 54091e8f889bSDavid Gibson } 54101e8f889bSDavid Gibson 541104f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 5412a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 5413a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 541404f2cbe3SMel Gorman { 541504f2cbe3SMel Gorman struct address_space *mapping; 5416e7c4b0bfSAndy Whitcroft pgoff_t idx; 541704f2cbe3SMel Gorman 541804f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 5419a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 542004f2cbe3SMel Gorman 542104f2cbe3SMel Gorman return find_lock_page(mapping, idx); 542204f2cbe3SMel Gorman } 542304f2cbe3SMel Gorman 54243ae77f43SHugh Dickins /* 54253ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 54263ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 54273ae77f43SHugh Dickins */ 54283ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 54292a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 54302a15efc9SHugh Dickins { 54312a15efc9SHugh Dickins struct address_space *mapping; 54322a15efc9SHugh Dickins pgoff_t idx; 54332a15efc9SHugh Dickins struct page *page; 54342a15efc9SHugh Dickins 54352a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 54362a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 54372a15efc9SHugh Dickins 54382a15efc9SHugh Dickins page = find_get_page(mapping, idx); 54392a15efc9SHugh Dickins if (page) 54402a15efc9SHugh Dickins put_page(page); 54412a15efc9SHugh Dickins return page != NULL; 54422a15efc9SHugh Dickins } 54432a15efc9SHugh Dickins 5444ab76ad54SMike Kravetz int huge_add_to_page_cache(struct page *page, struct address_space *mapping, 5445ab76ad54SMike Kravetz pgoff_t idx) 5446ab76ad54SMike Kravetz { 5447d9ef44deSMatthew Wilcox (Oracle) struct folio *folio = page_folio(page); 5448ab76ad54SMike Kravetz struct inode *inode = mapping->host; 5449ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 5450d9ef44deSMatthew Wilcox (Oracle) int err; 5451ab76ad54SMike Kravetz 5452d9ef44deSMatthew Wilcox (Oracle) __folio_set_locked(folio); 5453d9ef44deSMatthew Wilcox (Oracle) err = __filemap_add_folio(mapping, folio, idx, GFP_KERNEL, NULL); 5454d9ef44deSMatthew Wilcox (Oracle) 5455d9ef44deSMatthew Wilcox (Oracle) if (unlikely(err)) { 5456d9ef44deSMatthew Wilcox (Oracle) __folio_clear_locked(folio); 5457ab76ad54SMike Kravetz return err; 5458d9ef44deSMatthew Wilcox (Oracle) } 5459d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5460ab76ad54SMike Kravetz 546122146c3cSMike Kravetz /* 5462d9ef44deSMatthew Wilcox (Oracle) * mark folio dirty so that it will not be removed from cache/file 546322146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 546422146c3cSMike Kravetz */ 5465d9ef44deSMatthew Wilcox (Oracle) folio_mark_dirty(folio); 546622146c3cSMike Kravetz 5467ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 5468ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 5469ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 5470ab76ad54SMike Kravetz return 0; 5471ab76ad54SMike Kravetz } 5472ab76ad54SMike Kravetz 54737677f7fdSAxel Rasmussen static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma, 54747677f7fdSAxel Rasmussen struct address_space *mapping, 54757677f7fdSAxel Rasmussen pgoff_t idx, 54767677f7fdSAxel Rasmussen unsigned int flags, 54777677f7fdSAxel Rasmussen unsigned long haddr, 5478824ddc60SNadav Amit unsigned long addr, 54797677f7fdSAxel Rasmussen unsigned long reason) 54807677f7fdSAxel Rasmussen { 54817677f7fdSAxel Rasmussen vm_fault_t ret; 54827677f7fdSAxel Rasmussen u32 hash; 54837677f7fdSAxel Rasmussen struct vm_fault vmf = { 54847677f7fdSAxel Rasmussen .vma = vma, 54857677f7fdSAxel Rasmussen .address = haddr, 5486824ddc60SNadav Amit .real_address = addr, 54877677f7fdSAxel Rasmussen .flags = flags, 54887677f7fdSAxel Rasmussen 54897677f7fdSAxel Rasmussen /* 54907677f7fdSAxel Rasmussen * Hard to debug if it ends up being 54917677f7fdSAxel Rasmussen * used by a callee that assumes 54927677f7fdSAxel Rasmussen * something about the other 54937677f7fdSAxel Rasmussen * uninitialized fields... same as in 54947677f7fdSAxel Rasmussen * memory.c 54957677f7fdSAxel Rasmussen */ 54967677f7fdSAxel Rasmussen }; 54977677f7fdSAxel Rasmussen 54987677f7fdSAxel Rasmussen /* 54997677f7fdSAxel Rasmussen * hugetlb_fault_mutex and i_mmap_rwsem must be 55007677f7fdSAxel Rasmussen * dropped before handling userfault. Reacquire 55017677f7fdSAxel Rasmussen * after handling fault to make calling code simpler. 55027677f7fdSAxel Rasmussen */ 55037677f7fdSAxel Rasmussen hash = hugetlb_fault_mutex_hash(mapping, idx); 55047677f7fdSAxel Rasmussen mutex_unlock(&hugetlb_fault_mutex_table[hash]); 55057677f7fdSAxel Rasmussen i_mmap_unlock_read(mapping); 55067677f7fdSAxel Rasmussen ret = handle_userfault(&vmf, reason); 55077677f7fdSAxel Rasmussen i_mmap_lock_read(mapping); 55087677f7fdSAxel Rasmussen mutex_lock(&hugetlb_fault_mutex_table[hash]); 55097677f7fdSAxel Rasmussen 55107677f7fdSAxel Rasmussen return ret; 55117677f7fdSAxel Rasmussen } 55127677f7fdSAxel Rasmussen 55132b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 55142b740303SSouptick Joarder struct vm_area_struct *vma, 55158382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 5516c64e912cSPeter Xu unsigned long address, pte_t *ptep, 5517c64e912cSPeter Xu pte_t old_pte, unsigned int flags) 5518ac9b9c66SHugh Dickins { 5519a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 55202b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 5521409eb8c2SHillf Danton int anon_rmap = 0; 55224c887265SAdam Litke unsigned long size; 55234c887265SAdam Litke struct page *page; 55241e8f889bSDavid Gibson pte_t new_pte; 5525cb900f41SKirill A. Shutemov spinlock_t *ptl; 5526285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 5527c7b1850dSMike Kravetz bool new_page, new_pagecache_page = false; 55284c887265SAdam Litke 552904f2cbe3SMel Gorman /* 553004f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 553104f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 5532c89357e2SDavid Hildenbrand * COW/unsharing. Warn that such a situation has occurred as it may not 5533c89357e2SDavid Hildenbrand * be obvious. 553404f2cbe3SMel Gorman */ 553504f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 5536910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 553704f2cbe3SMel Gorman current->pid); 553804f2cbe3SMel Gorman return ret; 553904f2cbe3SMel Gorman } 554004f2cbe3SMel Gorman 55414c887265SAdam Litke /* 554287bf91d3SMike Kravetz * We can not race with truncation due to holding i_mmap_rwsem. 554387bf91d3SMike Kravetz * i_size is modified when holding i_mmap_rwsem, so check here 554487bf91d3SMike Kravetz * once for faults beyond end of file. 55454c887265SAdam Litke */ 5546a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 5547ebed4bfcSHugh Dickins if (idx >= size) 5548ebed4bfcSHugh Dickins goto out; 55491a1aad8aSMike Kravetz 555087bf91d3SMike Kravetz retry: 5551c7b1850dSMike Kravetz new_page = false; 555287bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 555387bf91d3SMike Kravetz if (!page) { 55547677f7fdSAxel Rasmussen /* Check for page in userfault range */ 55551a1aad8aSMike Kravetz if (userfaultfd_missing(vma)) { 55567677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 5557824ddc60SNadav Amit flags, haddr, address, 55587677f7fdSAxel Rasmussen VM_UFFD_MISSING); 55591a1aad8aSMike Kravetz goto out; 55601a1aad8aSMike Kravetz } 55611a1aad8aSMike Kravetz 5562285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 55632fc39cecSAdam Litke if (IS_ERR(page)) { 55644643d67eSMike Kravetz /* 55654643d67eSMike Kravetz * Returning error will result in faulting task being 55664643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 55674643d67eSMike Kravetz * tasks from racing to fault in the same page which 55684643d67eSMike Kravetz * could result in false unable to allocate errors. 55694643d67eSMike Kravetz * Page migration does not take the fault mutex, but 55704643d67eSMike Kravetz * does a clear then write of pte's under page table 55714643d67eSMike Kravetz * lock. Page fault code could race with migration, 55724643d67eSMike Kravetz * notice the clear pte and try to allocate a page 55734643d67eSMike Kravetz * here. Before returning error, get ptl and make 55744643d67eSMike Kravetz * sure there really is no pte entry. 55754643d67eSMike Kravetz */ 55764643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 55774643d67eSMike Kravetz ret = 0; 5578d83e6c8aSMiaohe Lin if (huge_pte_none(huge_ptep_get(ptep))) 55792b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 5580d83e6c8aSMiaohe Lin spin_unlock(ptl); 55816bda666aSChristoph Lameter goto out; 55826bda666aSChristoph Lameter } 558347ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 55840ed361deSNick Piggin __SetPageUptodate(page); 5585cb6acd01SMike Kravetz new_page = true; 5586ac9b9c66SHugh Dickins 5587f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 5588ab76ad54SMike Kravetz int err = huge_add_to_page_cache(page, mapping, idx); 55896bda666aSChristoph Lameter if (err) { 55906bda666aSChristoph Lameter put_page(page); 55916bda666aSChristoph Lameter if (err == -EEXIST) 55926bda666aSChristoph Lameter goto retry; 55936bda666aSChristoph Lameter goto out; 55946bda666aSChristoph Lameter } 5595c7b1850dSMike Kravetz new_pagecache_page = true; 559623be7468SMel Gorman } else { 55976bda666aSChristoph Lameter lock_page(page); 55980fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 55990fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 56000fe6e20bSNaoya Horiguchi goto backout_unlocked; 560123be7468SMel Gorman } 5602409eb8c2SHillf Danton anon_rmap = 1; 56030fe6e20bSNaoya Horiguchi } 56040fe6e20bSNaoya Horiguchi } else { 560557303d80SAndy Whitcroft /* 5606998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 5607998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 5608998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 5609fd6a03edSNaoya Horiguchi */ 5610fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 56110eb98f15SMiaohe Lin ret = VM_FAULT_HWPOISON_LARGE | 5612972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5613fd6a03edSNaoya Horiguchi goto backout_unlocked; 56146bda666aSChristoph Lameter } 56157677f7fdSAxel Rasmussen 56167677f7fdSAxel Rasmussen /* Check for page in userfault range. */ 56177677f7fdSAxel Rasmussen if (userfaultfd_minor(vma)) { 56187677f7fdSAxel Rasmussen unlock_page(page); 56197677f7fdSAxel Rasmussen put_page(page); 56207677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 5621824ddc60SNadav Amit flags, haddr, address, 56227677f7fdSAxel Rasmussen VM_UFFD_MINOR); 56237677f7fdSAxel Rasmussen goto out; 56247677f7fdSAxel Rasmussen } 5625998b4382SNaoya Horiguchi } 56261e8f889bSDavid Gibson 562757303d80SAndy Whitcroft /* 562857303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 562957303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 563057303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 563157303d80SAndy Whitcroft * the spinlock. 563257303d80SAndy Whitcroft */ 56335e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 5634285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 56352b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 56362b26736cSAndy Whitcroft goto backout_unlocked; 56372b26736cSAndy Whitcroft } 56385e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5639285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 56405e911373SMike Kravetz } 564157303d80SAndy Whitcroft 56428bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 564383c54070SNick Piggin ret = 0; 5644c64e912cSPeter Xu /* If pte changed from under us, retry */ 5645c64e912cSPeter Xu if (!pte_same(huge_ptep_get(ptep), old_pte)) 56464c887265SAdam Litke goto backout; 56474c887265SAdam Litke 564807443a85SJoonsoo Kim if (anon_rmap) { 5649d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5650285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 5651ac714904SChoi Gi-yong } else 5652fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 56531e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 56541e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 5655c64e912cSPeter Xu /* 5656c64e912cSPeter Xu * If this pte was previously wr-protected, keep it wr-protected even 5657c64e912cSPeter Xu * if populated. 5658c64e912cSPeter Xu */ 5659c64e912cSPeter Xu if (unlikely(pte_marker_uffd_wp(old_pte))) 5660c64e912cSPeter Xu new_pte = huge_pte_wrprotect(huge_pte_mkuffd_wp(new_pte)); 5661285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 56621e8f889bSDavid Gibson 56635d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 5664788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 56651e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 5666c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, page, ptl); 56671e8f889bSDavid Gibson } 56681e8f889bSDavid Gibson 5669cb900f41SKirill A. Shutemov spin_unlock(ptl); 5670cb6acd01SMike Kravetz 5671cb6acd01SMike Kravetz /* 56728f251a3dSMike Kravetz * Only set HPageMigratable in newly allocated pages. Existing pages 56738f251a3dSMike Kravetz * found in the pagecache may not have HPageMigratableset if they have 56748f251a3dSMike Kravetz * been isolated for migration. 5675cb6acd01SMike Kravetz */ 5676cb6acd01SMike Kravetz if (new_page) 56778f251a3dSMike Kravetz SetHPageMigratable(page); 5678cb6acd01SMike Kravetz 56794c887265SAdam Litke unlock_page(page); 56804c887265SAdam Litke out: 5681ac9b9c66SHugh Dickins return ret; 56824c887265SAdam Litke 56834c887265SAdam Litke backout: 5684cb900f41SKirill A. Shutemov spin_unlock(ptl); 56852b26736cSAndy Whitcroft backout_unlocked: 56864c887265SAdam Litke unlock_page(page); 5687c7b1850dSMike Kravetz /* restore reserve for newly allocated pages not in page cache */ 5688c7b1850dSMike Kravetz if (new_page && !new_pagecache_page) 5689285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 56904c887265SAdam Litke put_page(page); 56914c887265SAdam Litke goto out; 5692ac9b9c66SHugh Dickins } 5693ac9b9c66SHugh Dickins 56948382d914SDavidlohr Bueso #ifdef CONFIG_SMP 5695188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 56968382d914SDavidlohr Bueso { 56978382d914SDavidlohr Bueso unsigned long key[2]; 56988382d914SDavidlohr Bueso u32 hash; 56998382d914SDavidlohr Bueso 57008382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 57018382d914SDavidlohr Bueso key[1] = idx; 57028382d914SDavidlohr Bueso 570355254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 57048382d914SDavidlohr Bueso 57058382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 57068382d914SDavidlohr Bueso } 57078382d914SDavidlohr Bueso #else 57088382d914SDavidlohr Bueso /* 57096c26d310SMiaohe Lin * For uniprocessor systems we always use a single mutex, so just 57108382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 57118382d914SDavidlohr Bueso */ 5712188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 57138382d914SDavidlohr Bueso { 57148382d914SDavidlohr Bueso return 0; 57158382d914SDavidlohr Bueso } 57168382d914SDavidlohr Bueso #endif 57178382d914SDavidlohr Bueso 57182b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 5719788c7df4SHugh Dickins unsigned long address, unsigned int flags) 572086e5216fSAdam Litke { 57218382d914SDavidlohr Bueso pte_t *ptep, entry; 5722cb900f41SKirill A. Shutemov spinlock_t *ptl; 57232b740303SSouptick Joarder vm_fault_t ret; 57248382d914SDavidlohr Bueso u32 hash; 57258382d914SDavidlohr Bueso pgoff_t idx; 57260fe6e20bSNaoya Horiguchi struct page *page = NULL; 572757303d80SAndy Whitcroft struct page *pagecache_page = NULL; 5728a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 57298382d914SDavidlohr Bueso struct address_space *mapping; 57300f792cf9SNaoya Horiguchi int need_wait_lock = 0; 5731285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 573286e5216fSAdam Litke 5733285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5734fd6a03edSNaoya Horiguchi if (ptep) { 5735c0d0381aSMike Kravetz /* 5736c0d0381aSMike Kravetz * Since we hold no locks, ptep could be stale. That is 5737c0d0381aSMike Kravetz * OK as we are only making decisions based on content and 5738c0d0381aSMike Kravetz * not actually modifying content here. 5739c0d0381aSMike Kravetz */ 5740fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 5741290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 5742ad1ac596SMiaohe Lin migration_entry_wait_huge(vma, ptep); 5743290408d4SNaoya Horiguchi return 0; 5744290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 5745aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 5746972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5747b43a9990SMike Kravetz } 57488382d914SDavidlohr Bueso 5749c0d0381aSMike Kravetz /* 5750c0d0381aSMike Kravetz * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold 575187bf91d3SMike Kravetz * until finished with ptep. This serves two purposes: 575287bf91d3SMike Kravetz * 1) It prevents huge_pmd_unshare from being called elsewhere 575387bf91d3SMike Kravetz * and making the ptep no longer valid. 575487bf91d3SMike Kravetz * 2) It synchronizes us with i_size modifications during truncation. 5755c0d0381aSMike Kravetz * 5756c0d0381aSMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 5757c0d0381aSMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 5758c0d0381aSMike Kravetz * something has changed. 5759c0d0381aSMike Kravetz */ 5760ddeaab32SMike Kravetz mapping = vma->vm_file->f_mapping; 5761c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 5762aec44e0fSPeter Xu ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h)); 5763c0d0381aSMike Kravetz if (!ptep) { 5764c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 5765c0d0381aSMike Kravetz return VM_FAULT_OOM; 5766c0d0381aSMike Kravetz } 5767ddeaab32SMike Kravetz 57683935baa9SDavid Gibson /* 57693935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 57703935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 57713935baa9SDavid Gibson * the same page in the page cache. 57723935baa9SDavid Gibson */ 5773c0d0381aSMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 5774188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 5775c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 57768382d914SDavidlohr Bueso 57777f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 5778c64e912cSPeter Xu /* PTE markers should be handled the same way as none pte */ 5779c64e912cSPeter Xu if (huge_pte_none_mostly(entry)) { 5780c64e912cSPeter Xu ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, 5781c64e912cSPeter Xu entry, flags); 5782b4d1d99fSDavid Gibson goto out_mutex; 57833935baa9SDavid Gibson } 578486e5216fSAdam Litke 578583c54070SNick Piggin ret = 0; 57861e8f889bSDavid Gibson 578757303d80SAndy Whitcroft /* 57880f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 57890f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 57907c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 57917c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 57927c8de358SEthon Paul * properly handle it. 57930f792cf9SNaoya Horiguchi */ 57940f792cf9SNaoya Horiguchi if (!pte_present(entry)) 57950f792cf9SNaoya Horiguchi goto out_mutex; 57960f792cf9SNaoya Horiguchi 57970f792cf9SNaoya Horiguchi /* 5798c89357e2SDavid Hildenbrand * If we are going to COW/unshare the mapping later, we examine the 5799c89357e2SDavid Hildenbrand * pending reservations for this page now. This will ensure that any 580057303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 58011d8d1464SDavid Hildenbrand * spinlock. Also lookup the pagecache page now as it is used to 58021d8d1464SDavid Hildenbrand * determine if a reservation has been consumed. 580357303d80SAndy Whitcroft */ 5804c89357e2SDavid Hildenbrand if ((flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) && 58051d8d1464SDavid Hildenbrand !(vma->vm_flags & VM_MAYSHARE) && !huge_pte_write(entry)) { 5806285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 58072b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 5808b4d1d99fSDavid Gibson goto out_mutex; 58092b26736cSAndy Whitcroft } 58105e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5811285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 581257303d80SAndy Whitcroft 58131d8d1464SDavid Hildenbrand pagecache_page = hugetlbfs_pagecache_page(h, vma, haddr); 581457303d80SAndy Whitcroft } 581557303d80SAndy Whitcroft 58160f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 58170fe6e20bSNaoya Horiguchi 5818c89357e2SDavid Hildenbrand /* Check for a racing update before calling hugetlb_wp() */ 5819b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 5820cb900f41SKirill A. Shutemov goto out_ptl; 5821b4d1d99fSDavid Gibson 5822166f3eccSPeter Xu /* Handle userfault-wp first, before trying to lock more pages */ 5823166f3eccSPeter Xu if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) && 5824166f3eccSPeter Xu (flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 5825166f3eccSPeter Xu struct vm_fault vmf = { 5826166f3eccSPeter Xu .vma = vma, 5827166f3eccSPeter Xu .address = haddr, 5828166f3eccSPeter Xu .real_address = address, 5829166f3eccSPeter Xu .flags = flags, 5830166f3eccSPeter Xu }; 5831166f3eccSPeter Xu 5832166f3eccSPeter Xu spin_unlock(ptl); 5833166f3eccSPeter Xu if (pagecache_page) { 5834166f3eccSPeter Xu unlock_page(pagecache_page); 5835166f3eccSPeter Xu put_page(pagecache_page); 5836166f3eccSPeter Xu } 5837166f3eccSPeter Xu mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5838166f3eccSPeter Xu i_mmap_unlock_read(mapping); 5839166f3eccSPeter Xu return handle_userfault(&vmf, VM_UFFD_WP); 5840166f3eccSPeter Xu } 5841166f3eccSPeter Xu 58420f792cf9SNaoya Horiguchi /* 5843c89357e2SDavid Hildenbrand * hugetlb_wp() requires page locks of pte_page(entry) and 58440f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 58450f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 58460f792cf9SNaoya Horiguchi */ 58470f792cf9SNaoya Horiguchi page = pte_page(entry); 58480f792cf9SNaoya Horiguchi if (page != pagecache_page) 58490f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 58500f792cf9SNaoya Horiguchi need_wait_lock = 1; 58510f792cf9SNaoya Horiguchi goto out_ptl; 58520f792cf9SNaoya Horiguchi } 58530f792cf9SNaoya Horiguchi 58540f792cf9SNaoya Horiguchi get_page(page); 5855b4d1d99fSDavid Gibson 5856c89357e2SDavid Hildenbrand if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) { 5857106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 5858c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, 5859cb900f41SKirill A. Shutemov pagecache_page, ptl); 58600f792cf9SNaoya Horiguchi goto out_put_page; 5861c89357e2SDavid Hildenbrand } else if (likely(flags & FAULT_FLAG_WRITE)) { 5862106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 5863b4d1d99fSDavid Gibson } 5864c89357e2SDavid Hildenbrand } 5865b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 5866285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 5867788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 5868285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 58690f792cf9SNaoya Horiguchi out_put_page: 58700f792cf9SNaoya Horiguchi if (page != pagecache_page) 58710f792cf9SNaoya Horiguchi unlock_page(page); 58720f792cf9SNaoya Horiguchi put_page(page); 5873cb900f41SKirill A. Shutemov out_ptl: 5874cb900f41SKirill A. Shutemov spin_unlock(ptl); 587557303d80SAndy Whitcroft 587657303d80SAndy Whitcroft if (pagecache_page) { 587757303d80SAndy Whitcroft unlock_page(pagecache_page); 587857303d80SAndy Whitcroft put_page(pagecache_page); 587957303d80SAndy Whitcroft } 5880b4d1d99fSDavid Gibson out_mutex: 5881c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5882c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 58830f792cf9SNaoya Horiguchi /* 58840f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 58850f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 58860f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 58870f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 58880f792cf9SNaoya Horiguchi * here without taking refcount. 58890f792cf9SNaoya Horiguchi */ 58900f792cf9SNaoya Horiguchi if (need_wait_lock) 58910f792cf9SNaoya Horiguchi wait_on_page_locked(page); 58921e8f889bSDavid Gibson return ret; 589386e5216fSAdam Litke } 589486e5216fSAdam Litke 5895714c1891SAxel Rasmussen #ifdef CONFIG_USERFAULTFD 58968fb5debcSMike Kravetz /* 58978fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 58988fb5debcSMike Kravetz * modifications for huge pages. 58998fb5debcSMike Kravetz */ 59008fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 59018fb5debcSMike Kravetz pte_t *dst_pte, 59028fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 59038fb5debcSMike Kravetz unsigned long dst_addr, 59048fb5debcSMike Kravetz unsigned long src_addr, 5905f6191471SAxel Rasmussen enum mcopy_atomic_mode mode, 59066041c691SPeter Xu struct page **pagep, 59076041c691SPeter Xu bool wp_copy) 59088fb5debcSMike Kravetz { 5909f6191471SAxel Rasmussen bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE); 59108cc5fcbbSMina Almasry struct hstate *h = hstate_vma(dst_vma); 59118cc5fcbbSMina Almasry struct address_space *mapping = dst_vma->vm_file->f_mapping; 59128cc5fcbbSMina Almasry pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr); 59131e392147SAndrea Arcangeli unsigned long size; 59141c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 59158fb5debcSMike Kravetz pte_t _dst_pte; 59168fb5debcSMike Kravetz spinlock_t *ptl; 59178cc5fcbbSMina Almasry int ret = -ENOMEM; 59188fb5debcSMike Kravetz struct page *page; 5919f6191471SAxel Rasmussen int writable; 5920cc30042dSMina Almasry bool page_in_pagecache = false; 59218fb5debcSMike Kravetz 5922f6191471SAxel Rasmussen if (is_continue) { 5923f6191471SAxel Rasmussen ret = -EFAULT; 5924f6191471SAxel Rasmussen page = find_lock_page(mapping, idx); 5925f6191471SAxel Rasmussen if (!page) 5926f6191471SAxel Rasmussen goto out; 5927cc30042dSMina Almasry page_in_pagecache = true; 5928f6191471SAxel Rasmussen } else if (!*pagep) { 5929d84cf06eSMina Almasry /* If a page already exists, then it's UFFDIO_COPY for 5930d84cf06eSMina Almasry * a non-missing case. Return -EEXIST. 5931d84cf06eSMina Almasry */ 5932d84cf06eSMina Almasry if (vm_shared && 5933d84cf06eSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 5934d84cf06eSMina Almasry ret = -EEXIST; 59358fb5debcSMike Kravetz goto out; 5936d84cf06eSMina Almasry } 5937d84cf06eSMina Almasry 5938d84cf06eSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 5939d84cf06eSMina Almasry if (IS_ERR(page)) { 5940d84cf06eSMina Almasry ret = -ENOMEM; 5941d84cf06eSMina Almasry goto out; 5942d84cf06eSMina Almasry } 59438fb5debcSMike Kravetz 59448fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 59458fb5debcSMike Kravetz (const void __user *) src_addr, 5946810a56b9SMike Kravetz pages_per_huge_page(h), false); 59478fb5debcSMike Kravetz 5948c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 59498fb5debcSMike Kravetz if (unlikely(ret)) { 59509e368259SAndrea Arcangeli ret = -ENOENT; 59518cc5fcbbSMina Almasry /* Free the allocated page which may have 59528cc5fcbbSMina Almasry * consumed a reservation. 59538cc5fcbbSMina Almasry */ 59548cc5fcbbSMina Almasry restore_reserve_on_error(h, dst_vma, dst_addr, page); 59558cc5fcbbSMina Almasry put_page(page); 59568cc5fcbbSMina Almasry 59578cc5fcbbSMina Almasry /* Allocate a temporary page to hold the copied 59588cc5fcbbSMina Almasry * contents. 59598cc5fcbbSMina Almasry */ 59608cc5fcbbSMina Almasry page = alloc_huge_page_vma(h, dst_vma, dst_addr); 59618cc5fcbbSMina Almasry if (!page) { 59628cc5fcbbSMina Almasry ret = -ENOMEM; 59638cc5fcbbSMina Almasry goto out; 59648cc5fcbbSMina Almasry } 59658fb5debcSMike Kravetz *pagep = page; 59668cc5fcbbSMina Almasry /* Set the outparam pagep and return to the caller to 59678cc5fcbbSMina Almasry * copy the contents outside the lock. Don't free the 59688cc5fcbbSMina Almasry * page. 59698cc5fcbbSMina Almasry */ 59708fb5debcSMike Kravetz goto out; 59718fb5debcSMike Kravetz } 59728fb5debcSMike Kravetz } else { 59738cc5fcbbSMina Almasry if (vm_shared && 59748cc5fcbbSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 59758cc5fcbbSMina Almasry put_page(*pagep); 59768cc5fcbbSMina Almasry ret = -EEXIST; 59778cc5fcbbSMina Almasry *pagep = NULL; 59788cc5fcbbSMina Almasry goto out; 59798cc5fcbbSMina Almasry } 59808cc5fcbbSMina Almasry 59818cc5fcbbSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 59828cc5fcbbSMina Almasry if (IS_ERR(page)) { 5983da9a298fSMiaohe Lin put_page(*pagep); 59848cc5fcbbSMina Almasry ret = -ENOMEM; 59858cc5fcbbSMina Almasry *pagep = NULL; 59868cc5fcbbSMina Almasry goto out; 59878cc5fcbbSMina Almasry } 598834892366SMuchun Song copy_user_huge_page(page, *pagep, dst_addr, dst_vma, 598934892366SMuchun Song pages_per_huge_page(h)); 59908cc5fcbbSMina Almasry put_page(*pagep); 59918fb5debcSMike Kravetz *pagep = NULL; 59928fb5debcSMike Kravetz } 59938fb5debcSMike Kravetz 59948fb5debcSMike Kravetz /* 59958fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 59968fb5debcSMike Kravetz * preceding stores to the page contents become visible before 59978fb5debcSMike Kravetz * the set_pte_at() write. 59988fb5debcSMike Kravetz */ 59998fb5debcSMike Kravetz __SetPageUptodate(page); 60008fb5debcSMike Kravetz 6001f6191471SAxel Rasmussen /* Add shared, newly allocated pages to the page cache. */ 6002f6191471SAxel Rasmussen if (vm_shared && !is_continue) { 60031e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 60041e392147SAndrea Arcangeli ret = -EFAULT; 60051e392147SAndrea Arcangeli if (idx >= size) 60061e392147SAndrea Arcangeli goto out_release_nounlock; 60071c9e8defSMike Kravetz 60081e392147SAndrea Arcangeli /* 60091e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 60101e392147SAndrea Arcangeli * huge_add_to_page_cache() below happens through the 60111e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 60121e392147SAndrea Arcangeli * the caller. 60131e392147SAndrea Arcangeli */ 60141c9e8defSMike Kravetz ret = huge_add_to_page_cache(page, mapping, idx); 60151c9e8defSMike Kravetz if (ret) 60161c9e8defSMike Kravetz goto out_release_nounlock; 6017cc30042dSMina Almasry page_in_pagecache = true; 60181c9e8defSMike Kravetz } 60191c9e8defSMike Kravetz 60208fb5debcSMike Kravetz ptl = huge_pte_lockptr(h, dst_mm, dst_pte); 60218fb5debcSMike Kravetz spin_lock(ptl); 60228fb5debcSMike Kravetz 60231e392147SAndrea Arcangeli /* 60241e392147SAndrea Arcangeli * Recheck the i_size after holding PT lock to make sure not 60251e392147SAndrea Arcangeli * to leave any page mapped (as page_mapped()) beyond the end 60261e392147SAndrea Arcangeli * of the i_size (remove_inode_hugepages() is strict about 60271e392147SAndrea Arcangeli * enforcing that). If we bail out here, we'll also leave a 60281e392147SAndrea Arcangeli * page in the radix tree in the vm_shared case beyond the end 60291e392147SAndrea Arcangeli * of the i_size, but remove_inode_hugepages() will take care 60301e392147SAndrea Arcangeli * of it as soon as we drop the hugetlb_fault_mutex_table. 60311e392147SAndrea Arcangeli */ 60321e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 60331e392147SAndrea Arcangeli ret = -EFAULT; 60341e392147SAndrea Arcangeli if (idx >= size) 60351e392147SAndrea Arcangeli goto out_release_unlock; 60361e392147SAndrea Arcangeli 60378fb5debcSMike Kravetz ret = -EEXIST; 60386041c691SPeter Xu /* 60396041c691SPeter Xu * We allow to overwrite a pte marker: consider when both MISSING|WP 60406041c691SPeter Xu * registered, we firstly wr-protect a none pte which has no page cache 60416041c691SPeter Xu * page backing it, then access the page. 60426041c691SPeter Xu */ 60436041c691SPeter Xu if (!huge_pte_none_mostly(huge_ptep_get(dst_pte))) 60448fb5debcSMike Kravetz goto out_release_unlock; 60458fb5debcSMike Kravetz 6046ab74ef70SMiaohe Lin if (page_in_pagecache) { 6047fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 60481c9e8defSMike Kravetz } else { 6049d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 60508fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 60511c9e8defSMike Kravetz } 60528fb5debcSMike Kravetz 60536041c691SPeter Xu /* 60546041c691SPeter Xu * For either: (1) CONTINUE on a non-shared VMA, or (2) UFFDIO_COPY 60556041c691SPeter Xu * with wp flag set, don't set pte write bit. 60566041c691SPeter Xu */ 60576041c691SPeter Xu if (wp_copy || (is_continue && !vm_shared)) 6058f6191471SAxel Rasmussen writable = 0; 6059f6191471SAxel Rasmussen else 6060f6191471SAxel Rasmussen writable = dst_vma->vm_flags & VM_WRITE; 6061f6191471SAxel Rasmussen 6062f6191471SAxel Rasmussen _dst_pte = make_huge_pte(dst_vma, page, writable); 60636041c691SPeter Xu /* 60646041c691SPeter Xu * Always mark UFFDIO_COPY page dirty; note that this may not be 60656041c691SPeter Xu * extremely important for hugetlbfs for now since swapping is not 60666041c691SPeter Xu * supported, but we should still be clear in that this page cannot be 60676041c691SPeter Xu * thrown away at will, even if write bit not set. 60686041c691SPeter Xu */ 60698fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 60708fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 60718fb5debcSMike Kravetz 60726041c691SPeter Xu if (wp_copy) 60736041c691SPeter Xu _dst_pte = huge_pte_mkuffd_wp(_dst_pte); 60746041c691SPeter Xu 60758fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 60768fb5debcSMike Kravetz 60778fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 60788fb5debcSMike Kravetz 60798fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 60808fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 60818fb5debcSMike Kravetz 60828fb5debcSMike Kravetz spin_unlock(ptl); 6083f6191471SAxel Rasmussen if (!is_continue) 60848f251a3dSMike Kravetz SetHPageMigratable(page); 6085f6191471SAxel Rasmussen if (vm_shared || is_continue) 60861c9e8defSMike Kravetz unlock_page(page); 60878fb5debcSMike Kravetz ret = 0; 60888fb5debcSMike Kravetz out: 60898fb5debcSMike Kravetz return ret; 60908fb5debcSMike Kravetz out_release_unlock: 60918fb5debcSMike Kravetz spin_unlock(ptl); 6092f6191471SAxel Rasmussen if (vm_shared || is_continue) 60931c9e8defSMike Kravetz unlock_page(page); 60945af10dfdSAndrea Arcangeli out_release_nounlock: 6095cc30042dSMina Almasry if (!page_in_pagecache) 6096846be085SMike Kravetz restore_reserve_on_error(h, dst_vma, dst_addr, page); 60978fb5debcSMike Kravetz put_page(page); 60988fb5debcSMike Kravetz goto out; 60998fb5debcSMike Kravetz } 6100714c1891SAxel Rasmussen #endif /* CONFIG_USERFAULTFD */ 61018fb5debcSMike Kravetz 610282e5d378SJoao Martins static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, 610382e5d378SJoao Martins int refs, struct page **pages, 610482e5d378SJoao Martins struct vm_area_struct **vmas) 610582e5d378SJoao Martins { 610682e5d378SJoao Martins int nr; 610782e5d378SJoao Martins 610882e5d378SJoao Martins for (nr = 0; nr < refs; nr++) { 610982e5d378SJoao Martins if (likely(pages)) 611082e5d378SJoao Martins pages[nr] = mem_map_offset(page, nr); 611182e5d378SJoao Martins if (vmas) 611282e5d378SJoao Martins vmas[nr] = vma; 611382e5d378SJoao Martins } 611482e5d378SJoao Martins } 611582e5d378SJoao Martins 6116a7f22660SDavid Hildenbrand static inline bool __follow_hugetlb_must_fault(unsigned int flags, pte_t *pte, 6117a7f22660SDavid Hildenbrand bool *unshare) 6118a7f22660SDavid Hildenbrand { 6119a7f22660SDavid Hildenbrand pte_t pteval = huge_ptep_get(pte); 6120a7f22660SDavid Hildenbrand 6121a7f22660SDavid Hildenbrand *unshare = false; 6122a7f22660SDavid Hildenbrand if (is_swap_pte(pteval)) 6123a7f22660SDavid Hildenbrand return true; 6124a7f22660SDavid Hildenbrand if (huge_pte_write(pteval)) 6125a7f22660SDavid Hildenbrand return false; 6126a7f22660SDavid Hildenbrand if (flags & FOLL_WRITE) 6127a7f22660SDavid Hildenbrand return true; 6128a7f22660SDavid Hildenbrand if (gup_must_unshare(flags, pte_page(pteval))) { 6129a7f22660SDavid Hildenbrand *unshare = true; 6130a7f22660SDavid Hildenbrand return true; 6131a7f22660SDavid Hildenbrand } 6132a7f22660SDavid Hildenbrand return false; 6133a7f22660SDavid Hildenbrand } 6134a7f22660SDavid Hildenbrand 613528a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 613663551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 613728a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 61384f6da934SPeter Xu long i, unsigned int flags, int *locked) 613963551ae0SDavid Gibson { 6140d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 6141d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 614228a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 6143a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 61440fa5bc40SJoao Martins int err = -EFAULT, refs; 614563551ae0SDavid Gibson 614663551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 614763551ae0SDavid Gibson pte_t *pte; 6148cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 6149a7f22660SDavid Hildenbrand bool unshare = false; 61502a15efc9SHugh Dickins int absent; 615163551ae0SDavid Gibson struct page *page; 615263551ae0SDavid Gibson 61534c887265SAdam Litke /* 615402057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 615502057967SDavid Rientjes * potentially allocating memory. 615602057967SDavid Rientjes */ 6157fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 615802057967SDavid Rientjes remainder = 0; 615902057967SDavid Rientjes break; 616002057967SDavid Rientjes } 616102057967SDavid Rientjes 616202057967SDavid Rientjes /* 61634c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 61642a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 61654c887265SAdam Litke * first, for the page indexing below to work. 6166cb900f41SKirill A. Shutemov * 6167cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 61684c887265SAdam Litke */ 61697868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 61707868a208SPunit Agrawal huge_page_size(h)); 6171cb900f41SKirill A. Shutemov if (pte) 6172cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 61732a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 617463551ae0SDavid Gibson 61752a15efc9SHugh Dickins /* 61762a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 61773ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 61783ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 61793ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 61803ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 61812a15efc9SHugh Dickins */ 61823ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 61833ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 6184cb900f41SKirill A. Shutemov if (pte) 6185cb900f41SKirill A. Shutemov spin_unlock(ptl); 61862a15efc9SHugh Dickins remainder = 0; 61872a15efc9SHugh Dickins break; 61882a15efc9SHugh Dickins } 61892a15efc9SHugh Dickins 61909cc3a5bdSNaoya Horiguchi /* 61919cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 61929cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 61939cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 61949cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 61959cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 61969cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 61979cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 61989cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 61999cc3a5bdSNaoya Horiguchi */ 6200a7f22660SDavid Hildenbrand if (absent || 6201a7f22660SDavid Hildenbrand __follow_hugetlb_must_fault(flags, pte, &unshare)) { 62022b740303SSouptick Joarder vm_fault_t ret; 620387ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 62044c887265SAdam Litke 6205cb900f41SKirill A. Shutemov if (pte) 6206cb900f41SKirill A. Shutemov spin_unlock(ptl); 620787ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 620887ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 6209a7f22660SDavid Hildenbrand else if (unshare) 6210a7f22660SDavid Hildenbrand fault_flags |= FAULT_FLAG_UNSHARE; 62114f6da934SPeter Xu if (locked) 621271335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 621371335f37SPeter Xu FAULT_FLAG_KILLABLE; 621487ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 621587ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 621687ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 621787ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 62184426e945SPeter Xu /* 62194426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 62204426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 62214426e945SPeter Xu */ 622287ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 622387ffc118SAndrea Arcangeli } 622487ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 622587ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 62262be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 62271c59827dSHugh Dickins remainder = 0; 62281c59827dSHugh Dickins break; 62291c59827dSHugh Dickins } 623087ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 62314f6da934SPeter Xu if (locked && 62321ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 62334f6da934SPeter Xu *locked = 0; 623487ffc118SAndrea Arcangeli *nr_pages = 0; 623587ffc118SAndrea Arcangeli /* 623687ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 623787ffc118SAndrea Arcangeli * error, it will return zero 623887ffc118SAndrea Arcangeli * instead. 623987ffc118SAndrea Arcangeli * 624087ffc118SAndrea Arcangeli * No need to update "position" as the 624187ffc118SAndrea Arcangeli * caller will not check it after 624287ffc118SAndrea Arcangeli * *nr_pages is set to 0. 624387ffc118SAndrea Arcangeli */ 624487ffc118SAndrea Arcangeli return i; 624587ffc118SAndrea Arcangeli } 624687ffc118SAndrea Arcangeli continue; 624787ffc118SAndrea Arcangeli } 624863551ae0SDavid Gibson 6249a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 62507f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 62518fde12caSLinus Torvalds 6252b6a2619cSDavid Hildenbrand VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && 6253b6a2619cSDavid Hildenbrand !PageAnonExclusive(page), page); 6254b6a2619cSDavid Hildenbrand 62558fde12caSLinus Torvalds /* 6256acbfb087SZhigang Lu * If subpage information not requested, update counters 6257acbfb087SZhigang Lu * and skip the same_page loop below. 6258acbfb087SZhigang Lu */ 6259acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 6260acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 6261acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 6262acbfb087SZhigang Lu vaddr += huge_page_size(h); 6263acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 6264acbfb087SZhigang Lu i += pages_per_huge_page(h); 6265acbfb087SZhigang Lu spin_unlock(ptl); 6266acbfb087SZhigang Lu continue; 6267acbfb087SZhigang Lu } 6268acbfb087SZhigang Lu 6269d08af0a5SJoao Martins /* vaddr may not be aligned to PAGE_SIZE */ 6270d08af0a5SJoao Martins refs = min3(pages_per_huge_page(h) - pfn_offset, remainder, 6271d08af0a5SJoao Martins (vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT); 62720fa5bc40SJoao Martins 627382e5d378SJoao Martins if (pages || vmas) 627482e5d378SJoao Martins record_subpages_vmas(mem_map_offset(page, pfn_offset), 627582e5d378SJoao Martins vma, refs, 627682e5d378SJoao Martins likely(pages) ? pages + i : NULL, 627782e5d378SJoao Martins vmas ? vmas + i : NULL); 627863551ae0SDavid Gibson 627982e5d378SJoao Martins if (pages) { 62800fa5bc40SJoao Martins /* 6281822951d8SMatthew Wilcox (Oracle) * try_grab_folio() should always succeed here, 62820fa5bc40SJoao Martins * because: a) we hold the ptl lock, and b) we've just 62830fa5bc40SJoao Martins * checked that the huge page is present in the page 62840fa5bc40SJoao Martins * tables. If the huge page is present, then the tail 62850fa5bc40SJoao Martins * pages must also be present. The ptl prevents the 62860fa5bc40SJoao Martins * head page and tail pages from being rearranged in 62870fa5bc40SJoao Martins * any way. So this page must be available at this 62880fa5bc40SJoao Martins * point, unless the page refcount overflowed: 62890fa5bc40SJoao Martins */ 6290822951d8SMatthew Wilcox (Oracle) if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs, 62910fa5bc40SJoao Martins flags))) { 62920fa5bc40SJoao Martins spin_unlock(ptl); 62930fa5bc40SJoao Martins remainder = 0; 62940fa5bc40SJoao Martins err = -ENOMEM; 62950fa5bc40SJoao Martins break; 62960fa5bc40SJoao Martins } 6297d5d4b0aaSChen, Kenneth W } 629882e5d378SJoao Martins 629982e5d378SJoao Martins vaddr += (refs << PAGE_SHIFT); 630082e5d378SJoao Martins remainder -= refs; 630182e5d378SJoao Martins i += refs; 630282e5d378SJoao Martins 6303cb900f41SKirill A. Shutemov spin_unlock(ptl); 630463551ae0SDavid Gibson } 630528a35716SMichel Lespinasse *nr_pages = remainder; 630687ffc118SAndrea Arcangeli /* 630787ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 630887ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 630987ffc118SAndrea Arcangeli * branch. 631087ffc118SAndrea Arcangeli */ 631163551ae0SDavid Gibson *position = vaddr; 631263551ae0SDavid Gibson 63132be7cfedSDaniel Jordan return i ? i : err; 631463551ae0SDavid Gibson } 63158f860591SZhang, Yanmin 63167da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 63175a90d5a1SPeter Xu unsigned long address, unsigned long end, 63185a90d5a1SPeter Xu pgprot_t newprot, unsigned long cp_flags) 63198f860591SZhang, Yanmin { 63208f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 63218f860591SZhang, Yanmin unsigned long start = address; 63228f860591SZhang, Yanmin pte_t *ptep; 63238f860591SZhang, Yanmin pte_t pte; 6324a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 632560dfaad6SPeter Xu unsigned long pages = 0, psize = huge_page_size(h); 6326dff11abeSMike Kravetz bool shared_pmd = false; 6327ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 6328e95a9851SMike Kravetz unsigned long last_addr_mask; 63295a90d5a1SPeter Xu bool uffd_wp = cp_flags & MM_CP_UFFD_WP; 63305a90d5a1SPeter Xu bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; 6331dff11abeSMike Kravetz 6332dff11abeSMike Kravetz /* 6333dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 6334ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 6335dff11abeSMike Kravetz * range if PMD sharing is possible. 6336dff11abeSMike Kravetz */ 63377269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 63387269f999SJérôme Glisse 0, vma, mm, start, end); 6339ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 63408f860591SZhang, Yanmin 63418f860591SZhang, Yanmin BUG_ON(address >= end); 6342ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 63438f860591SZhang, Yanmin 6344ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 6345e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 634683cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 634760dfaad6SPeter Xu for (; address < end; address += psize) { 6348cb900f41SKirill A. Shutemov spinlock_t *ptl; 634960dfaad6SPeter Xu ptep = huge_pte_offset(mm, address, psize); 6350e95a9851SMike Kravetz if (!ptep) { 6351e95a9851SMike Kravetz address |= last_addr_mask; 63528f860591SZhang, Yanmin continue; 6353e95a9851SMike Kravetz } 6354cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 63554ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, address, ptep)) { 635660dfaad6SPeter Xu /* 635760dfaad6SPeter Xu * When uffd-wp is enabled on the vma, unshare 635860dfaad6SPeter Xu * shouldn't happen at all. Warn about it if it 635960dfaad6SPeter Xu * happened due to some reason. 636060dfaad6SPeter Xu */ 636160dfaad6SPeter Xu WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); 63627da4d641SPeter Zijlstra pages++; 6363cb900f41SKirill A. Shutemov spin_unlock(ptl); 6364dff11abeSMike Kravetz shared_pmd = true; 63654ddb4d91SMike Kravetz address |= last_addr_mask; 636639dde65cSChen, Kenneth W continue; 63677da4d641SPeter Zijlstra } 6368a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 6369a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 6370a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6371a8bda28dSNaoya Horiguchi continue; 6372a8bda28dSNaoya Horiguchi } 6373a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 6374a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 63756c287605SDavid Hildenbrand struct page *page = pfn_swap_entry_to_page(entry); 6376a8bda28dSNaoya Horiguchi 63776c287605SDavid Hildenbrand if (!is_readable_migration_entry(entry)) { 6378a8bda28dSNaoya Horiguchi pte_t newpte; 6379a8bda28dSNaoya Horiguchi 63806c287605SDavid Hildenbrand if (PageAnon(page)) 63816c287605SDavid Hildenbrand entry = make_readable_exclusive_migration_entry( 63826c287605SDavid Hildenbrand swp_offset(entry)); 63836c287605SDavid Hildenbrand else 63844dd845b5SAlistair Popple entry = make_readable_migration_entry( 63854dd845b5SAlistair Popple swp_offset(entry)); 6386a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 63875a90d5a1SPeter Xu if (uffd_wp) 63885a90d5a1SPeter Xu newpte = pte_swp_mkuffd_wp(newpte); 63895a90d5a1SPeter Xu else if (uffd_wp_resolve) 63905a90d5a1SPeter Xu newpte = pte_swp_clear_uffd_wp(newpte); 639118f39629SQi Zheng set_huge_pte_at(mm, address, ptep, newpte); 6392a8bda28dSNaoya Horiguchi pages++; 6393a8bda28dSNaoya Horiguchi } 6394a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6395a8bda28dSNaoya Horiguchi continue; 6396a8bda28dSNaoya Horiguchi } 639760dfaad6SPeter Xu if (unlikely(pte_marker_uffd_wp(pte))) { 639860dfaad6SPeter Xu /* 639960dfaad6SPeter Xu * This is changing a non-present pte into a none pte, 640060dfaad6SPeter Xu * no need for huge_ptep_modify_prot_start/commit(). 640160dfaad6SPeter Xu */ 640260dfaad6SPeter Xu if (uffd_wp_resolve) 640360dfaad6SPeter Xu huge_pte_clear(mm, address, ptep, psize); 640460dfaad6SPeter Xu } 6405a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 6406023bdd00SAneesh Kumar K.V pte_t old_pte; 640779c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 6408023bdd00SAneesh Kumar K.V 6409023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 641016785bd7SAnshuman Khandual pte = huge_pte_modify(old_pte, newprot); 641179c1c594SChristophe Leroy pte = arch_make_huge_pte(pte, shift, vma->vm_flags); 64125a90d5a1SPeter Xu if (uffd_wp) 64135a90d5a1SPeter Xu pte = huge_pte_mkuffd_wp(huge_pte_wrprotect(pte)); 64145a90d5a1SPeter Xu else if (uffd_wp_resolve) 64155a90d5a1SPeter Xu pte = huge_pte_clear_uffd_wp(pte); 6416023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 64177da4d641SPeter Zijlstra pages++; 641860dfaad6SPeter Xu } else { 641960dfaad6SPeter Xu /* None pte */ 642060dfaad6SPeter Xu if (unlikely(uffd_wp)) 642160dfaad6SPeter Xu /* Safe to modify directly (none->non-present). */ 642260dfaad6SPeter Xu set_huge_pte_at(mm, address, ptep, 642360dfaad6SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 64248f860591SZhang, Yanmin } 6425cb900f41SKirill A. Shutemov spin_unlock(ptl); 64268f860591SZhang, Yanmin } 6427d833352aSMel Gorman /* 6428c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 6429d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 6430c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 6431dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 6432dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 6433d833352aSMel Gorman */ 6434dff11abeSMike Kravetz if (shared_pmd) 6435ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 6436dff11abeSMike Kravetz else 64375491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 64380f10851eSJérôme Glisse /* 64390f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 64400f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 64410f10851eSJérôme Glisse * 6442ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 64430f10851eSJérôme Glisse */ 644483cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 6445ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 64467da4d641SPeter Zijlstra 64477da4d641SPeter Zijlstra return pages << h->order; 64488f860591SZhang, Yanmin } 64498f860591SZhang, Yanmin 645033b8f84aSMike Kravetz /* Return true if reservation was successful, false otherwise. */ 645133b8f84aSMike Kravetz bool hugetlb_reserve_pages(struct inode *inode, 6452a1e78772SMel Gorman long from, long to, 64535a6fe125SMel Gorman struct vm_area_struct *vma, 6454ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 6455e4e574b7SAdam Litke { 645633b8f84aSMike Kravetz long chg, add = -1; 6457a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 645890481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 64599119a41eSJoonsoo Kim struct resv_map *resv_map; 6460075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 64610db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 6462e4e574b7SAdam Litke 646363489f8eSMike Kravetz /* This should never happen */ 646463489f8eSMike Kravetz if (from > to) { 646563489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 646633b8f84aSMike Kravetz return false; 646763489f8eSMike Kravetz } 646863489f8eSMike Kravetz 6469a1e78772SMel Gorman /* 647017c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 647117c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 647290481622SDavid Gibson * without using reserves 647317c9d12eSMel Gorman */ 6474ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 647533b8f84aSMike Kravetz return true; 647617c9d12eSMel Gorman 647717c9d12eSMel Gorman /* 6478a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 6479a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 6480a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 6481a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 6482a1e78772SMel Gorman */ 64839119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 6484f27a5136SMike Kravetz /* 6485f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 6486f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 6487f27a5136SMike Kravetz * hugetlbfs_get_inode). 6488f27a5136SMike Kravetz */ 64894e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 64909119a41eSJoonsoo Kim 64910db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 64929119a41eSJoonsoo Kim 64939119a41eSJoonsoo Kim } else { 6494e9fe92aeSMina Almasry /* Private mapping. */ 64959119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 64965a6fe125SMel Gorman if (!resv_map) 649733b8f84aSMike Kravetz return false; 64985a6fe125SMel Gorman 649917c9d12eSMel Gorman chg = to - from; 650017c9d12eSMel Gorman 65015a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 65025a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 65035a6fe125SMel Gorman } 65045a6fe125SMel Gorman 650533b8f84aSMike Kravetz if (chg < 0) 6506c50ac050SDave Hansen goto out_err; 650717c9d12eSMel Gorman 650833b8f84aSMike Kravetz if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h), 650933b8f84aSMike Kravetz chg * pages_per_huge_page(h), &h_cg) < 0) 6510075a61d0SMina Almasry goto out_err; 6511075a61d0SMina Almasry 6512075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 6513075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 6514075a61d0SMina Almasry * of the resv_map. 6515075a61d0SMina Almasry */ 6516075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 6517075a61d0SMina Almasry } 6518075a61d0SMina Almasry 65191c5ecae3SMike Kravetz /* 65201c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 65211c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 65221c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 65231c5ecae3SMike Kravetz */ 65241c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 652533b8f84aSMike Kravetz if (gbl_reserve < 0) 6526075a61d0SMina Almasry goto out_uncharge_cgroup; 652717c9d12eSMel Gorman 652817c9d12eSMel Gorman /* 652917c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 653090481622SDavid Gibson * Hand the pages back to the subpool if there are not 653117c9d12eSMel Gorman */ 653233b8f84aSMike Kravetz if (hugetlb_acct_memory(h, gbl_reserve) < 0) 6533075a61d0SMina Almasry goto out_put_pages; 653417c9d12eSMel Gorman 653517c9d12eSMel Gorman /* 653617c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 653717c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 653817c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 653917c9d12eSMel Gorman * the reservation was and the page cache tells how much of 654017c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 654117c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 654217c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 654317c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 654417c9d12eSMel Gorman * else has to be done for private mappings here 654517c9d12eSMel Gorman */ 654633039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 6547075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 654833039678SMike Kravetz 65490db9d74eSMina Almasry if (unlikely(add < 0)) { 65500db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 6551075a61d0SMina Almasry goto out_put_pages; 65520db9d74eSMina Almasry } else if (unlikely(chg > add)) { 655333039678SMike Kravetz /* 655433039678SMike Kravetz * pages in this range were added to the reserve 655533039678SMike Kravetz * map between region_chg and region_add. This 655633039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 655733039678SMike Kravetz * the subpool and reserve counts modified above 655833039678SMike Kravetz * based on the difference. 655933039678SMike Kravetz */ 656033039678SMike Kravetz long rsv_adjust; 656133039678SMike Kravetz 6562d85aecf2SMiaohe Lin /* 6563d85aecf2SMiaohe Lin * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the 6564d85aecf2SMiaohe Lin * reference to h_cg->css. See comment below for detail. 6565d85aecf2SMiaohe Lin */ 6566075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 6567075a61d0SMina Almasry hstate_index(h), 6568075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 6569075a61d0SMina Almasry 657033039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 657133039678SMike Kravetz chg - add); 657233039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 6573d85aecf2SMiaohe Lin } else if (h_cg) { 6574d85aecf2SMiaohe Lin /* 6575d85aecf2SMiaohe Lin * The file_regions will hold their own reference to 6576d85aecf2SMiaohe Lin * h_cg->css. So we should release the reference held 6577d85aecf2SMiaohe Lin * via hugetlb_cgroup_charge_cgroup_rsvd() when we are 6578d85aecf2SMiaohe Lin * done. 6579d85aecf2SMiaohe Lin */ 6580d85aecf2SMiaohe Lin hugetlb_cgroup_put_rsvd_cgroup(h_cg); 658133039678SMike Kravetz } 658233039678SMike Kravetz } 658333b8f84aSMike Kravetz return true; 658433b8f84aSMike Kravetz 6585075a61d0SMina Almasry out_put_pages: 6586075a61d0SMina Almasry /* put back original number of pages, chg */ 6587075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 6588075a61d0SMina Almasry out_uncharge_cgroup: 6589075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 6590075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 6591c50ac050SDave Hansen out_err: 65925e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 65930db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 65940db9d74eSMina Almasry * region_add failed or didn't run. 65950db9d74eSMina Almasry */ 65960db9d74eSMina Almasry if (chg >= 0 && add < 0) 65970db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 6598f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 6599f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 660033b8f84aSMike Kravetz return false; 6601a43a8c39SChen, Kenneth W } 6602a43a8c39SChen, Kenneth W 6603b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 6604b5cec28dSMike Kravetz long freed) 6605a43a8c39SChen, Kenneth W { 6606a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 66074e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 66089119a41eSJoonsoo Kim long chg = 0; 660990481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 66101c5ecae3SMike Kravetz long gbl_reserve; 661145c682a6SKen Chen 6612f27a5136SMike Kravetz /* 6613f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 6614f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 6615f27a5136SMike Kravetz */ 6616b5cec28dSMike Kravetz if (resv_map) { 6617b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 6618b5cec28dSMike Kravetz /* 6619b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 6620b5cec28dSMike Kravetz * must be split and another region descriptor can not be 6621b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 6622b5cec28dSMike Kravetz */ 6623b5cec28dSMike Kravetz if (chg < 0) 6624b5cec28dSMike Kravetz return chg; 6625b5cec28dSMike Kravetz } 6626b5cec28dSMike Kravetz 662745c682a6SKen Chen spin_lock(&inode->i_lock); 6628e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 662945c682a6SKen Chen spin_unlock(&inode->i_lock); 663045c682a6SKen Chen 66311c5ecae3SMike Kravetz /* 66321c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 66331c5ecae3SMike Kravetz * reservations to be released may be adjusted. 6634dddf31a4SMiaohe Lin * 6635dddf31a4SMiaohe Lin * Note that !resv_map implies freed == 0. So (chg - freed) 6636dddf31a4SMiaohe Lin * won't go negative. 66371c5ecae3SMike Kravetz */ 66381c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 66391c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 6640b5cec28dSMike Kravetz 6641b5cec28dSMike Kravetz return 0; 6642a43a8c39SChen, Kenneth W } 664393f70f90SNaoya Horiguchi 66443212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 66453212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 66463212b535SSteve Capper struct vm_area_struct *vma, 66473212b535SSteve Capper unsigned long addr, pgoff_t idx) 66483212b535SSteve Capper { 66493212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 66503212b535SSteve Capper svma->vm_start; 66513212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 66523212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 66533212b535SSteve Capper 66543212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 6655de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 6656de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 66573212b535SSteve Capper 66583212b535SSteve Capper /* 66593212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 66603212b535SSteve Capper * page table page. 66613212b535SSteve Capper */ 66623212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 66633212b535SSteve Capper vm_flags != svm_flags || 666407e51edfSMiaohe Lin !range_in_vma(svma, sbase, s_end)) 66653212b535SSteve Capper return 0; 66663212b535SSteve Capper 66673212b535SSteve Capper return saddr; 66683212b535SSteve Capper } 66693212b535SSteve Capper 667031aafb45SNicholas Krause static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) 66713212b535SSteve Capper { 66723212b535SSteve Capper unsigned long base = addr & PUD_MASK; 66733212b535SSteve Capper unsigned long end = base + PUD_SIZE; 66743212b535SSteve Capper 66753212b535SSteve Capper /* 66763212b535SSteve Capper * check on proper vm_flags and page table alignment 66773212b535SSteve Capper */ 6678017b1660SMike Kravetz if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) 667931aafb45SNicholas Krause return true; 668031aafb45SNicholas Krause return false; 66813212b535SSteve Capper } 66823212b535SSteve Capper 6683c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6684c1991e07SPeter Xu { 6685c1991e07SPeter Xu #ifdef CONFIG_USERFAULTFD 6686c1991e07SPeter Xu if (uffd_disable_huge_pmd_share(vma)) 6687c1991e07SPeter Xu return false; 6688c1991e07SPeter Xu #endif 6689c1991e07SPeter Xu return vma_shareable(vma, addr); 6690c1991e07SPeter Xu } 6691c1991e07SPeter Xu 66923212b535SSteve Capper /* 6693017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 6694017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 6695017b1660SMike Kravetz * shared pmd mappings. 6696017b1660SMike Kravetz */ 6697017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6698017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6699017b1660SMike Kravetz { 6700a1ba9da8SLi Xinhai unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE), 6701a1ba9da8SLi Xinhai v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 6702017b1660SMike Kravetz 6703a1ba9da8SLi Xinhai /* 6704f0953a1bSIngo Molnar * vma needs to span at least one aligned PUD size, and the range 6705f0953a1bSIngo Molnar * must be at least partially within in. 6706a1ba9da8SLi Xinhai */ 6707a1ba9da8SLi Xinhai if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) || 6708a1ba9da8SLi Xinhai (*end <= v_start) || (*start >= v_end)) 6709017b1660SMike Kravetz return; 6710017b1660SMike Kravetz 671175802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 6712a1ba9da8SLi Xinhai if (*start > v_start) 6713a1ba9da8SLi Xinhai *start = ALIGN_DOWN(*start, PUD_SIZE); 6714017b1660SMike Kravetz 6715a1ba9da8SLi Xinhai if (*end < v_end) 6716a1ba9da8SLi Xinhai *end = ALIGN(*end, PUD_SIZE); 6717017b1660SMike Kravetz } 6718017b1660SMike Kravetz 6719017b1660SMike Kravetz /* 67203212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 67213212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 67223212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 6723c0d0381aSMike Kravetz * code much cleaner. 6724c0d0381aSMike Kravetz * 67250bf7b64eSMike Kravetz * This routine must be called with i_mmap_rwsem held in at least read mode if 67260bf7b64eSMike Kravetz * sharing is possible. For hugetlbfs, this prevents removal of any page 67270bf7b64eSMike Kravetz * table entries associated with the address space. This is important as we 67280bf7b64eSMike Kravetz * are setting up sharing based on existing page table entries (mappings). 67293212b535SSteve Capper */ 6730aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6731aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 67323212b535SSteve Capper { 67333212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 67343212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 67353212b535SSteve Capper vma->vm_pgoff; 67363212b535SSteve Capper struct vm_area_struct *svma; 67373212b535SSteve Capper unsigned long saddr; 67383212b535SSteve Capper pte_t *spte = NULL; 67393212b535SSteve Capper pte_t *pte; 6740cb900f41SKirill A. Shutemov spinlock_t *ptl; 67413212b535SSteve Capper 67420bf7b64eSMike Kravetz i_mmap_assert_locked(mapping); 67433212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 67443212b535SSteve Capper if (svma == vma) 67453212b535SSteve Capper continue; 67463212b535SSteve Capper 67473212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 67483212b535SSteve Capper if (saddr) { 67497868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 67507868a208SPunit Agrawal vma_mmu_pagesize(svma)); 67513212b535SSteve Capper if (spte) { 67523212b535SSteve Capper get_page(virt_to_page(spte)); 67533212b535SSteve Capper break; 67543212b535SSteve Capper } 67553212b535SSteve Capper } 67563212b535SSteve Capper } 67573212b535SSteve Capper 67583212b535SSteve Capper if (!spte) 67593212b535SSteve Capper goto out; 67603212b535SSteve Capper 67618bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 6762dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 67633212b535SSteve Capper pud_populate(mm, pud, 67643212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 6765c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 6766dc6c9a35SKirill A. Shutemov } else { 67673212b535SSteve Capper put_page(virt_to_page(spte)); 6768dc6c9a35SKirill A. Shutemov } 6769cb900f41SKirill A. Shutemov spin_unlock(ptl); 67703212b535SSteve Capper out: 67713212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 67723212b535SSteve Capper return pte; 67733212b535SSteve Capper } 67743212b535SSteve Capper 67753212b535SSteve Capper /* 67763212b535SSteve Capper * unmap huge page backed by shared pte. 67773212b535SSteve Capper * 67783212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 67793212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 67803212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 67813212b535SSteve Capper * 6782c0d0381aSMike Kravetz * Called with page table lock held and i_mmap_rwsem held in write mode. 67833212b535SSteve Capper * 67843212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 67853212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 67863212b535SSteve Capper */ 678734ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 67884ddb4d91SMike Kravetz unsigned long addr, pte_t *ptep) 67893212b535SSteve Capper { 67904ddb4d91SMike Kravetz pgd_t *pgd = pgd_offset(mm, addr); 67914ddb4d91SMike Kravetz p4d_t *p4d = p4d_offset(pgd, addr); 67924ddb4d91SMike Kravetz pud_t *pud = pud_offset(p4d, addr); 67933212b535SSteve Capper 679434ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 67953212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 67963212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 67973212b535SSteve Capper return 0; 67983212b535SSteve Capper 67993212b535SSteve Capper pud_clear(pud); 68003212b535SSteve Capper put_page(virt_to_page(ptep)); 6801dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 68023212b535SSteve Capper return 1; 68033212b535SSteve Capper } 6804c1991e07SPeter Xu 68059e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 6806aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6807aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 68089e5fc74cSSteve Capper { 68099e5fc74cSSteve Capper return NULL; 68109e5fc74cSSteve Capper } 6811e81f2d22SZhang Zhen 681234ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 68134ddb4d91SMike Kravetz unsigned long addr, pte_t *ptep) 6814e81f2d22SZhang Zhen { 6815e81f2d22SZhang Zhen return 0; 6816e81f2d22SZhang Zhen } 6817017b1660SMike Kravetz 6818017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6819017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6820017b1660SMike Kravetz { 6821017b1660SMike Kravetz } 6822c1991e07SPeter Xu 6823c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6824c1991e07SPeter Xu { 6825c1991e07SPeter Xu return false; 6826c1991e07SPeter Xu } 68273212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 68283212b535SSteve Capper 68299e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 6830aec44e0fSPeter Xu pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 68319e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 68329e5fc74cSSteve Capper { 68339e5fc74cSSteve Capper pgd_t *pgd; 6834c2febafcSKirill A. Shutemov p4d_t *p4d; 68359e5fc74cSSteve Capper pud_t *pud; 68369e5fc74cSSteve Capper pte_t *pte = NULL; 68379e5fc74cSSteve Capper 68389e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6839f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 6840f4f0a3d8SKirill A. Shutemov if (!p4d) 6841f4f0a3d8SKirill A. Shutemov return NULL; 6842c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 68439e5fc74cSSteve Capper if (pud) { 68449e5fc74cSSteve Capper if (sz == PUD_SIZE) { 68459e5fc74cSSteve Capper pte = (pte_t *)pud; 68469e5fc74cSSteve Capper } else { 68479e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 6848c1991e07SPeter Xu if (want_pmd_share(vma, addr) && pud_none(*pud)) 6849aec44e0fSPeter Xu pte = huge_pmd_share(mm, vma, addr, pud); 68509e5fc74cSSteve Capper else 68519e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 68529e5fc74cSSteve Capper } 68539e5fc74cSSteve Capper } 68544e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 68559e5fc74cSSteve Capper 68569e5fc74cSSteve Capper return pte; 68579e5fc74cSSteve Capper } 68589e5fc74cSSteve Capper 68599b19df29SPunit Agrawal /* 68609b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 68619b19df29SPunit Agrawal * entry at address @addr 68629b19df29SPunit Agrawal * 68638ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 68648ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 68659b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 68669b19df29SPunit Agrawal * table. 68679b19df29SPunit Agrawal */ 68687868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 68697868a208SPunit Agrawal unsigned long addr, unsigned long sz) 68709e5fc74cSSteve Capper { 68719e5fc74cSSteve Capper pgd_t *pgd; 6872c2febafcSKirill A. Shutemov p4d_t *p4d; 68738ac0b81aSLi Xinhai pud_t *pud; 68748ac0b81aSLi Xinhai pmd_t *pmd; 68759e5fc74cSSteve Capper 68769e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6877c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 6878c2febafcSKirill A. Shutemov return NULL; 6879c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 6880c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 6881c2febafcSKirill A. Shutemov return NULL; 68829b19df29SPunit Agrawal 6883c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 68848ac0b81aSLi Xinhai if (sz == PUD_SIZE) 68858ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 68869e5fc74cSSteve Capper return (pte_t *)pud; 68878ac0b81aSLi Xinhai if (!pud_present(*pud)) 68888ac0b81aSLi Xinhai return NULL; 68898ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 68909b19df29SPunit Agrawal 68919e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 68928ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 68939e5fc74cSSteve Capper return (pte_t *)pmd; 68949e5fc74cSSteve Capper } 68959e5fc74cSSteve Capper 6896e95a9851SMike Kravetz /* 6897e95a9851SMike Kravetz * Return a mask that can be used to update an address to the last huge 6898e95a9851SMike Kravetz * page in a page table page mapping size. Used to skip non-present 6899e95a9851SMike Kravetz * page table entries when linearly scanning address ranges. Architectures 6900e95a9851SMike Kravetz * with unique huge page to page table relationships can define their own 6901e95a9851SMike Kravetz * version of this routine. 6902e95a9851SMike Kravetz */ 6903e95a9851SMike Kravetz unsigned long hugetlb_mask_last_page(struct hstate *h) 6904e95a9851SMike Kravetz { 6905e95a9851SMike Kravetz unsigned long hp_size = huge_page_size(h); 6906e95a9851SMike Kravetz 6907e95a9851SMike Kravetz if (hp_size == PUD_SIZE) 6908e95a9851SMike Kravetz return P4D_SIZE - PUD_SIZE; 6909e95a9851SMike Kravetz else if (hp_size == PMD_SIZE) 6910e95a9851SMike Kravetz return PUD_SIZE - PMD_SIZE; 6911e95a9851SMike Kravetz else 6912e95a9851SMike Kravetz return 0UL; 6913e95a9851SMike Kravetz } 6914e95a9851SMike Kravetz 6915e95a9851SMike Kravetz #else 6916e95a9851SMike Kravetz 6917e95a9851SMike Kravetz /* See description above. Architectures can provide their own version. */ 6918e95a9851SMike Kravetz __weak unsigned long hugetlb_mask_last_page(struct hstate *h) 6919e95a9851SMike Kravetz { 69204ddb4d91SMike Kravetz #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 69214ddb4d91SMike Kravetz if (huge_page_size(h) == PMD_SIZE) 69224ddb4d91SMike Kravetz return PUD_SIZE - PMD_SIZE; 69234ddb4d91SMike Kravetz #endif 6924e95a9851SMike Kravetz return 0UL; 6925e95a9851SMike Kravetz } 6926e95a9851SMike Kravetz 692761f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 692861f77edaSNaoya Horiguchi 692961f77edaSNaoya Horiguchi /* 693061f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 693161f77edaSNaoya Horiguchi * behavior. 693261f77edaSNaoya Horiguchi */ 693361f77edaSNaoya Horiguchi struct page * __weak 693461f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 693561f77edaSNaoya Horiguchi int write) 693661f77edaSNaoya Horiguchi { 693761f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 693861f77edaSNaoya Horiguchi } 693961f77edaSNaoya Horiguchi 694061f77edaSNaoya Horiguchi struct page * __weak 69414dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 69424dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 69434dc71451SAneesh Kumar K.V { 69444dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 69454dc71451SAneesh Kumar K.V return NULL; 69464dc71451SAneesh Kumar K.V } 69474dc71451SAneesh Kumar K.V 69484dc71451SAneesh Kumar K.V struct page * __weak 69499e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 6950e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 69519e5fc74cSSteve Capper { 6952e66f17ffSNaoya Horiguchi struct page *page = NULL; 6953e66f17ffSNaoya Horiguchi spinlock_t *ptl; 6954c9d398faSNaoya Horiguchi pte_t pte; 69553faa52c0SJohn Hubbard 69568909691bSDavid Hildenbrand /* 69578909691bSDavid Hildenbrand * FOLL_PIN is not supported for follow_page(). Ordinary GUP goes via 69588909691bSDavid Hildenbrand * follow_hugetlb_page(). 69598909691bSDavid Hildenbrand */ 69608909691bSDavid Hildenbrand if (WARN_ON_ONCE(flags & FOLL_PIN)) 69613faa52c0SJohn Hubbard return NULL; 69623faa52c0SJohn Hubbard 6963e66f17ffSNaoya Horiguchi retry: 6964e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 6965e66f17ffSNaoya Horiguchi spin_lock(ptl); 6966e66f17ffSNaoya Horiguchi /* 6967e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 6968e66f17ffSNaoya Horiguchi * unmapped from other threads. 6969e66f17ffSNaoya Horiguchi */ 6970e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 6971e66f17ffSNaoya Horiguchi goto out; 6972c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 6973c9d398faSNaoya Horiguchi if (pte_present(pte)) { 697497534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 69753faa52c0SJohn Hubbard /* 69763faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 69773faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 69783faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 69793faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 69803faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 69813faa52c0SJohn Hubbard * unless the page refcount overflowed: 69823faa52c0SJohn Hubbard */ 69833faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 69843faa52c0SJohn Hubbard page = NULL; 69853faa52c0SJohn Hubbard goto out; 69863faa52c0SJohn Hubbard } 6987e66f17ffSNaoya Horiguchi } else { 6988c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 6989e66f17ffSNaoya Horiguchi spin_unlock(ptl); 6990ad1ac596SMiaohe Lin __migration_entry_wait_huge((pte_t *)pmd, ptl); 6991e66f17ffSNaoya Horiguchi goto retry; 6992e66f17ffSNaoya Horiguchi } 6993e66f17ffSNaoya Horiguchi /* 6994e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 6995e66f17ffSNaoya Horiguchi * follow_page_mask(). 6996e66f17ffSNaoya Horiguchi */ 6997e66f17ffSNaoya Horiguchi } 6998e66f17ffSNaoya Horiguchi out: 6999e66f17ffSNaoya Horiguchi spin_unlock(ptl); 70009e5fc74cSSteve Capper return page; 70019e5fc74cSSteve Capper } 70029e5fc74cSSteve Capper 700361f77edaSNaoya Horiguchi struct page * __weak 70049e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 7005e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 70069e5fc74cSSteve Capper { 70073a194f3fSNaoya Horiguchi struct page *page = NULL; 70083a194f3fSNaoya Horiguchi spinlock_t *ptl; 70093a194f3fSNaoya Horiguchi pte_t pte; 70103a194f3fSNaoya Horiguchi 70113a194f3fSNaoya Horiguchi if (WARN_ON_ONCE(flags & FOLL_PIN)) 7012e66f17ffSNaoya Horiguchi return NULL; 70139e5fc74cSSteve Capper 70143a194f3fSNaoya Horiguchi retry: 70153a194f3fSNaoya Horiguchi ptl = huge_pte_lock(hstate_sizelog(PUD_SHIFT), mm, (pte_t *)pud); 70163a194f3fSNaoya Horiguchi if (!pud_huge(*pud)) 70173a194f3fSNaoya Horiguchi goto out; 70183a194f3fSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pud); 70193a194f3fSNaoya Horiguchi if (pte_present(pte)) { 70203a194f3fSNaoya Horiguchi page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 70213a194f3fSNaoya Horiguchi if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 70223a194f3fSNaoya Horiguchi page = NULL; 70233a194f3fSNaoya Horiguchi goto out; 70243a194f3fSNaoya Horiguchi } 70253a194f3fSNaoya Horiguchi } else { 70263a194f3fSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 70273a194f3fSNaoya Horiguchi spin_unlock(ptl); 70283a194f3fSNaoya Horiguchi __migration_entry_wait(mm, (pte_t *)pud, ptl); 70293a194f3fSNaoya Horiguchi goto retry; 70303a194f3fSNaoya Horiguchi } 70313a194f3fSNaoya Horiguchi /* 70323a194f3fSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 70333a194f3fSNaoya Horiguchi * follow_page_mask(). 70343a194f3fSNaoya Horiguchi */ 70353a194f3fSNaoya Horiguchi } 70363a194f3fSNaoya Horiguchi out: 70373a194f3fSNaoya Horiguchi spin_unlock(ptl); 70383a194f3fSNaoya Horiguchi return page; 70399e5fc74cSSteve Capper } 70409e5fc74cSSteve Capper 7041faaa5b62SAnshuman Khandual struct page * __weak 7042faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 7043faaa5b62SAnshuman Khandual { 70443faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 7045faaa5b62SAnshuman Khandual return NULL; 7046faaa5b62SAnshuman Khandual 7047faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 7048faaa5b62SAnshuman Khandual } 7049faaa5b62SAnshuman Khandual 70507ce82f4cSMiaohe Lin int isolate_hugetlb(struct page *page, struct list_head *list) 705131caf665SNaoya Horiguchi { 70527ce82f4cSMiaohe Lin int ret = 0; 7053bcc54222SNaoya Horiguchi 7054db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 70558f251a3dSMike Kravetz if (!PageHeadHuge(page) || 70568f251a3dSMike Kravetz !HPageMigratable(page) || 70570eb2df2bSMuchun Song !get_page_unless_zero(page)) { 70587ce82f4cSMiaohe Lin ret = -EBUSY; 7059bcc54222SNaoya Horiguchi goto unlock; 7060bcc54222SNaoya Horiguchi } 70618f251a3dSMike Kravetz ClearHPageMigratable(page); 706231caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 7063bcc54222SNaoya Horiguchi unlock: 7064db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7065bcc54222SNaoya Horiguchi return ret; 706631caf665SNaoya Horiguchi } 706731caf665SNaoya Horiguchi 706825182f05SNaoya Horiguchi int get_hwpoison_huge_page(struct page *page, bool *hugetlb) 706925182f05SNaoya Horiguchi { 707025182f05SNaoya Horiguchi int ret = 0; 707125182f05SNaoya Horiguchi 707225182f05SNaoya Horiguchi *hugetlb = false; 707325182f05SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 707425182f05SNaoya Horiguchi if (PageHeadHuge(page)) { 707525182f05SNaoya Horiguchi *hugetlb = true; 7076b283d983SNaoya Horiguchi if (HPageFreed(page)) 7077b283d983SNaoya Horiguchi ret = 0; 7078b283d983SNaoya Horiguchi else if (HPageMigratable(page)) 707925182f05SNaoya Horiguchi ret = get_page_unless_zero(page); 70800ed950d1SNaoya Horiguchi else 70810ed950d1SNaoya Horiguchi ret = -EBUSY; 708225182f05SNaoya Horiguchi } 708325182f05SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 708425182f05SNaoya Horiguchi return ret; 708525182f05SNaoya Horiguchi } 708625182f05SNaoya Horiguchi 7087405ce051SNaoya Horiguchi int get_huge_page_for_hwpoison(unsigned long pfn, int flags) 7088405ce051SNaoya Horiguchi { 7089405ce051SNaoya Horiguchi int ret; 7090405ce051SNaoya Horiguchi 7091405ce051SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 7092405ce051SNaoya Horiguchi ret = __get_huge_page_for_hwpoison(pfn, flags); 7093405ce051SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 7094405ce051SNaoya Horiguchi return ret; 7095405ce051SNaoya Horiguchi } 7096405ce051SNaoya Horiguchi 709731caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 709831caf665SNaoya Horiguchi { 7099db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 71008f251a3dSMike Kravetz SetHPageMigratable(page); 710131caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 7102db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 710331caf665SNaoya Horiguchi put_page(page); 710431caf665SNaoya Horiguchi } 7105ab5ac90aSMichal Hocko 7106ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 7107ab5ac90aSMichal Hocko { 7108ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 7109ab5ac90aSMichal Hocko 7110ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 7111ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 7112ab5ac90aSMichal Hocko 7113ab5ac90aSMichal Hocko /* 7114ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 7115ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 7116ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 7117ab5ac90aSMichal Hocko * the temporary status. 7118ab5ac90aSMichal Hocko * 7119ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 7120ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 7121ab5ac90aSMichal Hocko * the per-node's. 7122ab5ac90aSMichal Hocko */ 71239157c311SMike Kravetz if (HPageTemporary(newpage)) { 7124ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 7125ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 7126ab5ac90aSMichal Hocko 71279157c311SMike Kravetz SetHPageTemporary(oldpage); 71289157c311SMike Kravetz ClearHPageTemporary(newpage); 7129ab5ac90aSMichal Hocko 71305af1ab1dSMiaohe Lin /* 71315af1ab1dSMiaohe Lin * There is no need to transfer the per-node surplus state 71325af1ab1dSMiaohe Lin * when we do not cross the node. 71335af1ab1dSMiaohe Lin */ 71345af1ab1dSMiaohe Lin if (new_nid == old_nid) 71355af1ab1dSMiaohe Lin return; 7136db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 7137ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 7138ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 7139ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 7140ab5ac90aSMichal Hocko } 7141db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7142ab5ac90aSMichal Hocko } 7143ab5ac90aSMichal Hocko } 7144cf11e85fSRoman Gushchin 71456dfeaff9SPeter Xu /* 71466dfeaff9SPeter Xu * This function will unconditionally remove all the shared pmd pgtable entries 71476dfeaff9SPeter Xu * within the specific vma for a hugetlbfs memory range. 71486dfeaff9SPeter Xu */ 71496dfeaff9SPeter Xu void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) 71506dfeaff9SPeter Xu { 71516dfeaff9SPeter Xu struct hstate *h = hstate_vma(vma); 71526dfeaff9SPeter Xu unsigned long sz = huge_page_size(h); 71536dfeaff9SPeter Xu struct mm_struct *mm = vma->vm_mm; 71546dfeaff9SPeter Xu struct mmu_notifier_range range; 71556dfeaff9SPeter Xu unsigned long address, start, end; 71566dfeaff9SPeter Xu spinlock_t *ptl; 71576dfeaff9SPeter Xu pte_t *ptep; 71586dfeaff9SPeter Xu 71596dfeaff9SPeter Xu if (!(vma->vm_flags & VM_MAYSHARE)) 71606dfeaff9SPeter Xu return; 71616dfeaff9SPeter Xu 71626dfeaff9SPeter Xu start = ALIGN(vma->vm_start, PUD_SIZE); 71636dfeaff9SPeter Xu end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 71646dfeaff9SPeter Xu 71656dfeaff9SPeter Xu if (start >= end) 71666dfeaff9SPeter Xu return; 71676dfeaff9SPeter Xu 71689c8bbfacSBaolin Wang flush_cache_range(vma, start, end); 71696dfeaff9SPeter Xu /* 71706dfeaff9SPeter Xu * No need to call adjust_range_if_pmd_sharing_possible(), because 71716dfeaff9SPeter Xu * we have already done the PUD_SIZE alignment. 71726dfeaff9SPeter Xu */ 71736dfeaff9SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 71746dfeaff9SPeter Xu start, end); 71756dfeaff9SPeter Xu mmu_notifier_invalidate_range_start(&range); 71766dfeaff9SPeter Xu i_mmap_lock_write(vma->vm_file->f_mapping); 71776dfeaff9SPeter Xu for (address = start; address < end; address += PUD_SIZE) { 71786dfeaff9SPeter Xu ptep = huge_pte_offset(mm, address, sz); 71796dfeaff9SPeter Xu if (!ptep) 71806dfeaff9SPeter Xu continue; 71816dfeaff9SPeter Xu ptl = huge_pte_lock(h, mm, ptep); 71824ddb4d91SMike Kravetz huge_pmd_unshare(mm, vma, address, ptep); 71836dfeaff9SPeter Xu spin_unlock(ptl); 71846dfeaff9SPeter Xu } 71856dfeaff9SPeter Xu flush_hugetlb_tlb_range(vma, start, end); 71866dfeaff9SPeter Xu i_mmap_unlock_write(vma->vm_file->f_mapping); 71876dfeaff9SPeter Xu /* 71886dfeaff9SPeter Xu * No need to call mmu_notifier_invalidate_range(), see 7189ee65728eSMike Rapoport * Documentation/mm/mmu_notifier.rst. 71906dfeaff9SPeter Xu */ 71916dfeaff9SPeter Xu mmu_notifier_invalidate_range_end(&range); 71926dfeaff9SPeter Xu } 71936dfeaff9SPeter Xu 7194cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 7195cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 7196cf11e85fSRoman Gushchin 7197cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 7198cf11e85fSRoman Gushchin { 719938e719abSBaolin Wang int nid, count = 0; 720038e719abSBaolin Wang unsigned long tmp; 720138e719abSBaolin Wang char *s = p; 720238e719abSBaolin Wang 720338e719abSBaolin Wang while (*s) { 720438e719abSBaolin Wang if (sscanf(s, "%lu%n", &tmp, &count) != 1) 720538e719abSBaolin Wang break; 720638e719abSBaolin Wang 720738e719abSBaolin Wang if (s[count] == ':') { 7208f9317f77SMike Kravetz if (tmp >= MAX_NUMNODES) 720938e719abSBaolin Wang break; 7210f9317f77SMike Kravetz nid = array_index_nospec(tmp, MAX_NUMNODES); 721138e719abSBaolin Wang 721238e719abSBaolin Wang s += count + 1; 721338e719abSBaolin Wang tmp = memparse(s, &s); 721438e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = tmp; 721538e719abSBaolin Wang hugetlb_cma_size += tmp; 721638e719abSBaolin Wang 721738e719abSBaolin Wang /* 721838e719abSBaolin Wang * Skip the separator if have one, otherwise 721938e719abSBaolin Wang * break the parsing. 722038e719abSBaolin Wang */ 722138e719abSBaolin Wang if (*s == ',') 722238e719abSBaolin Wang s++; 722338e719abSBaolin Wang else 722438e719abSBaolin Wang break; 722538e719abSBaolin Wang } else { 7226cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 722738e719abSBaolin Wang break; 722838e719abSBaolin Wang } 722938e719abSBaolin Wang } 723038e719abSBaolin Wang 7231cf11e85fSRoman Gushchin return 0; 7232cf11e85fSRoman Gushchin } 7233cf11e85fSRoman Gushchin 7234cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 7235cf11e85fSRoman Gushchin 7236cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 7237cf11e85fSRoman Gushchin { 7238cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 723938e719abSBaolin Wang bool node_specific_cma_alloc = false; 7240cf11e85fSRoman Gushchin int nid; 7241cf11e85fSRoman Gushchin 7242cf11e85fSRoman Gushchin cma_reserve_called = true; 7243cf11e85fSRoman Gushchin 7244cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 7245cf11e85fSRoman Gushchin return; 7246cf11e85fSRoman Gushchin 724738e719abSBaolin Wang for (nid = 0; nid < MAX_NUMNODES; nid++) { 724838e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 724938e719abSBaolin Wang continue; 725038e719abSBaolin Wang 725130a51400SPeng Liu if (!node_online(nid)) { 725238e719abSBaolin Wang pr_warn("hugetlb_cma: invalid node %d specified\n", nid); 725338e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 725438e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 725538e719abSBaolin Wang continue; 725638e719abSBaolin Wang } 725738e719abSBaolin Wang 725838e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] < (PAGE_SIZE << order)) { 725938e719abSBaolin Wang pr_warn("hugetlb_cma: cma area of node %d should be at least %lu MiB\n", 726038e719abSBaolin Wang nid, (PAGE_SIZE << order) / SZ_1M); 726138e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 726238e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 726338e719abSBaolin Wang } else { 726438e719abSBaolin Wang node_specific_cma_alloc = true; 726538e719abSBaolin Wang } 726638e719abSBaolin Wang } 726738e719abSBaolin Wang 726838e719abSBaolin Wang /* Validate the CMA size again in case some invalid nodes specified. */ 726938e719abSBaolin Wang if (!hugetlb_cma_size) 727038e719abSBaolin Wang return; 727138e719abSBaolin Wang 7272cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 7273cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 7274cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 7275a01f4390SMike Kravetz hugetlb_cma_size = 0; 7276cf11e85fSRoman Gushchin return; 7277cf11e85fSRoman Gushchin } 7278cf11e85fSRoman Gushchin 727938e719abSBaolin Wang if (!node_specific_cma_alloc) { 7280cf11e85fSRoman Gushchin /* 7281cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 7282cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 7283cf11e85fSRoman Gushchin */ 7284cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 7285cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 7286cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 728738e719abSBaolin Wang } 7288cf11e85fSRoman Gushchin 7289cf11e85fSRoman Gushchin reserved = 0; 729030a51400SPeng Liu for_each_online_node(nid) { 7291cf11e85fSRoman Gushchin int res; 72922281f797SBarry Song char name[CMA_MAX_NAME]; 7293cf11e85fSRoman Gushchin 729438e719abSBaolin Wang if (node_specific_cma_alloc) { 729538e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 729638e719abSBaolin Wang continue; 729738e719abSBaolin Wang 729838e719abSBaolin Wang size = hugetlb_cma_size_in_node[nid]; 729938e719abSBaolin Wang } else { 7300cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 730138e719abSBaolin Wang } 730238e719abSBaolin Wang 7303cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 7304cf11e85fSRoman Gushchin 73052281f797SBarry Song snprintf(name, sizeof(name), "hugetlb%d", nid); 7306a01f4390SMike Kravetz /* 7307a01f4390SMike Kravetz * Note that 'order per bit' is based on smallest size that 7308a01f4390SMike Kravetz * may be returned to CMA allocator in the case of 7309a01f4390SMike Kravetz * huge page demotion. 7310a01f4390SMike Kravetz */ 7311a01f4390SMike Kravetz res = cma_declare_contiguous_nid(0, size, 0, 7312a01f4390SMike Kravetz PAGE_SIZE << HUGETLB_PAGE_ORDER, 731329d0f41dSBarry Song 0, false, name, 7314cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 7315cf11e85fSRoman Gushchin if (res) { 7316cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 7317cf11e85fSRoman Gushchin res, nid); 7318cf11e85fSRoman Gushchin continue; 7319cf11e85fSRoman Gushchin } 7320cf11e85fSRoman Gushchin 7321cf11e85fSRoman Gushchin reserved += size; 7322cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 7323cf11e85fSRoman Gushchin size / SZ_1M, nid); 7324cf11e85fSRoman Gushchin 7325cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 7326cf11e85fSRoman Gushchin break; 7327cf11e85fSRoman Gushchin } 7328a01f4390SMike Kravetz 7329a01f4390SMike Kravetz if (!reserved) 7330a01f4390SMike Kravetz /* 7331a01f4390SMike Kravetz * hugetlb_cma_size is used to determine if allocations from 7332a01f4390SMike Kravetz * cma are possible. Set to zero if no cma regions are set up. 7333a01f4390SMike Kravetz */ 7334a01f4390SMike Kravetz hugetlb_cma_size = 0; 7335cf11e85fSRoman Gushchin } 7336cf11e85fSRoman Gushchin 7337cf11e85fSRoman Gushchin void __init hugetlb_cma_check(void) 7338cf11e85fSRoman Gushchin { 7339cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 7340cf11e85fSRoman Gushchin return; 7341cf11e85fSRoman Gushchin 7342cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 7343cf11e85fSRoman Gushchin } 7344cf11e85fSRoman Gushchin 7345cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 7346