1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_HUGETLB_H
3 #define _LINUX_HUGETLB_H
4
5 #include <linux/mm.h>
6 #include <linux/mm_types.h>
7 #include <linux/mmdebug.h>
8 #include <linux/fs.h>
9 #include <linux/hugetlb_inline.h>
10 #include <linux/cgroup.h>
11 #include <linux/page_ref.h>
12 #include <linux/list.h>
13 #include <linux/kref.h>
14 #include <linux/pgtable.h>
15 #include <linux/gfp.h>
16 #include <linux/userfaultfd_k.h>
17
18 struct ctl_table;
19 struct user_struct;
20 struct mmu_gather;
21 struct node;
22
23 #ifndef CONFIG_ARCH_HAS_HUGEPD
24 typedef struct { unsigned long pd; } hugepd_t;
25 #define is_hugepd(hugepd) (0)
26 #define __hugepd(x) ((hugepd_t) { (x) })
27 #endif
28
29 void free_huge_folio(struct folio *folio);
30
31 #ifdef CONFIG_HUGETLB_PAGE
32
33 #include <linux/pagemap.h>
34 #include <linux/shm.h>
35 #include <asm/tlbflush.h>
36
37 /*
38 * For HugeTLB page, there are more metadata to save in the struct page. But
39 * the head struct page cannot meet our needs, so we have to abuse other tail
40 * struct page to store the metadata.
41 */
42 #define __NR_USED_SUBPAGE 3
43
44 struct hugepage_subpool {
45 spinlock_t lock;
46 long count;
47 long max_hpages; /* Maximum huge pages or -1 if no maximum. */
48 long used_hpages; /* Used count against maximum, includes */
49 /* both allocated and reserved pages. */
50 struct hstate *hstate;
51 long min_hpages; /* Minimum huge pages or -1 if no minimum. */
52 long rsv_hpages; /* Pages reserved against global pool to */
53 /* satisfy minimum size. */
54 };
55
56 struct resv_map {
57 struct kref refs;
58 spinlock_t lock;
59 struct list_head regions;
60 long adds_in_progress;
61 struct list_head region_cache;
62 long region_cache_count;
63 struct rw_semaphore rw_sema;
64 #ifdef CONFIG_CGROUP_HUGETLB
65 /*
66 * On private mappings, the counter to uncharge reservations is stored
67 * here. If these fields are 0, then either the mapping is shared, or
68 * cgroup accounting is disabled for this resv_map.
69 */
70 struct page_counter *reservation_counter;
71 unsigned long pages_per_hpage;
72 struct cgroup_subsys_state *css;
73 #endif
74 };
75
76 /*
77 * Region tracking -- allows tracking of reservations and instantiated pages
78 * across the pages in a mapping.
79 *
80 * The region data structures are embedded into a resv_map and protected
81 * by a resv_map's lock. The set of regions within the resv_map represent
82 * reservations for huge pages, or huge pages that have already been
83 * instantiated within the map. The from and to elements are huge page
84 * indices into the associated mapping. from indicates the starting index
85 * of the region. to represents the first index past the end of the region.
86 *
87 * For example, a file region structure with from == 0 and to == 4 represents
88 * four huge pages in a mapping. It is important to note that the to element
89 * represents the first element past the end of the region. This is used in
90 * arithmetic as 4(to) - 0(from) = 4 huge pages in the region.
91 *
92 * Interval notation of the form [from, to) will be used to indicate that
93 * the endpoint from is inclusive and to is exclusive.
94 */
95 struct file_region {
96 struct list_head link;
97 long from;
98 long to;
99 #ifdef CONFIG_CGROUP_HUGETLB
100 /*
101 * On shared mappings, each reserved region appears as a struct
102 * file_region in resv_map. These fields hold the info needed to
103 * uncharge each reservation.
104 */
105 struct page_counter *reservation_counter;
106 struct cgroup_subsys_state *css;
107 #endif
108 };
109
110 struct hugetlb_vma_lock {
111 struct kref refs;
112 struct rw_semaphore rw_sema;
113 struct vm_area_struct *vma;
114 };
115
116 extern struct resv_map *resv_map_alloc(void);
117 void resv_map_release(struct kref *ref);
118
119 extern spinlock_t hugetlb_lock;
120 extern int hugetlb_max_hstate __read_mostly;
121 #define for_each_hstate(h) \
122 for ((h) = hstates; (h) < &hstates[hugetlb_max_hstate]; (h)++)
123
124 struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
125 long min_hpages);
126 void hugepage_put_subpool(struct hugepage_subpool *spool);
127
128 void hugetlb_dup_vma_private(struct vm_area_struct *vma);
129 void clear_vma_resv_huge_pages(struct vm_area_struct *vma);
130 int move_hugetlb_page_tables(struct vm_area_struct *vma,
131 struct vm_area_struct *new_vma,
132 unsigned long old_addr, unsigned long new_addr,
133 unsigned long len);
134 int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *,
135 struct vm_area_struct *, struct vm_area_struct *);
136 struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
137 unsigned long address, unsigned int flags,
138 unsigned int *page_mask);
139 void unmap_hugepage_range(struct vm_area_struct *,
140 unsigned long, unsigned long, struct page *,
141 zap_flags_t);
142 void __unmap_hugepage_range(struct mmu_gather *tlb,
143 struct vm_area_struct *vma,
144 unsigned long start, unsigned long end,
145 struct page *ref_page, zap_flags_t zap_flags);
146 void hugetlb_report_meminfo(struct seq_file *);
147 int hugetlb_report_node_meminfo(char *buf, int len, int nid);
148 void hugetlb_show_meminfo_node(int nid);
149 unsigned long hugetlb_total_pages(void);
150 vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
151 unsigned long address, unsigned int flags);
152 #ifdef CONFIG_USERFAULTFD
153 int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
154 struct vm_area_struct *dst_vma,
155 unsigned long dst_addr,
156 unsigned long src_addr,
157 uffd_flags_t flags,
158 struct folio **foliop);
159 #endif /* CONFIG_USERFAULTFD */
160 bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
161 struct vm_area_struct *vma,
162 vm_flags_t vm_flags);
163 long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
164 long freed);
165 bool isolate_hugetlb(struct folio *folio, struct list_head *list);
166 int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison);
167 int get_huge_page_for_hwpoison(unsigned long pfn, int flags,
168 bool *migratable_cleared);
169 void folio_putback_active_hugetlb(struct folio *folio);
170 void move_hugetlb_state(struct folio *old_folio, struct folio *new_folio, int reason);
171 void hugetlb_fix_reserve_counts(struct inode *inode);
172 extern struct mutex *hugetlb_fault_mutex_table;
173 u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx);
174
175 pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma,
176 unsigned long addr, pud_t *pud);
177 bool hugetlbfs_pagecache_present(struct hstate *h,
178 struct vm_area_struct *vma,
179 unsigned long address);
180
181 struct address_space *hugetlb_folio_mapping_lock_write(struct folio *folio);
182
183 extern int sysctl_hugetlb_shm_group;
184 extern struct list_head huge_boot_pages[MAX_NUMNODES];
185
186 /* arch callbacks */
187
188 #ifndef CONFIG_HIGHPTE
189 /*
190 * pte_offset_huge() and pte_alloc_huge() are helpers for those architectures
191 * which may go down to the lowest PTE level in their huge_pte_offset() and
192 * huge_pte_alloc(): to avoid reliance on pte_offset_map() without pte_unmap().
193 */
pte_offset_huge(pmd_t * pmd,unsigned long address)194 static inline pte_t *pte_offset_huge(pmd_t *pmd, unsigned long address)
195 {
196 return pte_offset_kernel(pmd, address);
197 }
pte_alloc_huge(struct mm_struct * mm,pmd_t * pmd,unsigned long address)198 static inline pte_t *pte_alloc_huge(struct mm_struct *mm, pmd_t *pmd,
199 unsigned long address)
200 {
201 return pte_alloc(mm, pmd) ? NULL : pte_offset_huge(pmd, address);
202 }
203 #endif
204
205 pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
206 unsigned long addr, unsigned long sz);
207 /*
208 * huge_pte_offset(): Walk the hugetlb pgtable until the last level PTE.
209 * Returns the pte_t* if found, or NULL if the address is not mapped.
210 *
211 * IMPORTANT: we should normally not directly call this function, instead
212 * this is only a common interface to implement arch-specific
213 * walker. Please use hugetlb_walk() instead, because that will attempt to
214 * verify the locking for you.
215 *
216 * Since this function will walk all the pgtable pages (including not only
217 * high-level pgtable page, but also PUD entry that can be unshared
218 * concurrently for VM_SHARED), the caller of this function should be
219 * responsible of its thread safety. One can follow this rule:
220 *
221 * (1) For private mappings: pmd unsharing is not possible, so holding the
222 * mmap_lock for either read or write is sufficient. Most callers
223 * already hold the mmap_lock, so normally, no special action is
224 * required.
225 *
226 * (2) For shared mappings: pmd unsharing is possible (so the PUD-ranged
227 * pgtable page can go away from under us! It can be done by a pmd
228 * unshare with a follow up munmap() on the other process), then we
229 * need either:
230 *
231 * (2.1) hugetlb vma lock read or write held, to make sure pmd unshare
232 * won't happen upon the range (it also makes sure the pte_t we
233 * read is the right and stable one), or,
234 *
235 * (2.2) hugetlb mapping i_mmap_rwsem lock held read or write, to make
236 * sure even if unshare happened the racy unmap() will wait until
237 * i_mmap_rwsem is released.
238 *
239 * Option (2.1) is the safest, which guarantees pte stability from pmd
240 * sharing pov, until the vma lock released. Option (2.2) doesn't protect
241 * a concurrent pmd unshare, but it makes sure the pgtable page is safe to
242 * access.
243 */
244 pte_t *huge_pte_offset(struct mm_struct *mm,
245 unsigned long addr, unsigned long sz);
246 unsigned long hugetlb_mask_last_page(struct hstate *h);
247 int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma,
248 unsigned long addr, pte_t *ptep);
249 void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
250 unsigned long *start, unsigned long *end);
251
252 extern void __hugetlb_zap_begin(struct vm_area_struct *vma,
253 unsigned long *begin, unsigned long *end);
254 extern void __hugetlb_zap_end(struct vm_area_struct *vma,
255 struct zap_details *details);
256
hugetlb_zap_begin(struct vm_area_struct * vma,unsigned long * start,unsigned long * end)257 static inline void hugetlb_zap_begin(struct vm_area_struct *vma,
258 unsigned long *start, unsigned long *end)
259 {
260 if (is_vm_hugetlb_page(vma))
261 __hugetlb_zap_begin(vma, start, end);
262 }
263
hugetlb_zap_end(struct vm_area_struct * vma,struct zap_details * details)264 static inline void hugetlb_zap_end(struct vm_area_struct *vma,
265 struct zap_details *details)
266 {
267 if (is_vm_hugetlb_page(vma))
268 __hugetlb_zap_end(vma, details);
269 }
270
271 void hugetlb_vma_lock_read(struct vm_area_struct *vma);
272 void hugetlb_vma_unlock_read(struct vm_area_struct *vma);
273 void hugetlb_vma_lock_write(struct vm_area_struct *vma);
274 void hugetlb_vma_unlock_write(struct vm_area_struct *vma);
275 int hugetlb_vma_trylock_write(struct vm_area_struct *vma);
276 void hugetlb_vma_assert_locked(struct vm_area_struct *vma);
277 void hugetlb_vma_lock_release(struct kref *kref);
278 long hugetlb_change_protection(struct vm_area_struct *vma,
279 unsigned long address, unsigned long end, pgprot_t newprot,
280 unsigned long cp_flags);
281 bool is_hugetlb_entry_migration(pte_t pte);
282 bool is_hugetlb_entry_hwpoisoned(pte_t pte);
283 void hugetlb_unshare_all_pmds(struct vm_area_struct *vma);
284
285 #else /* !CONFIG_HUGETLB_PAGE */
286
hugetlb_dup_vma_private(struct vm_area_struct * vma)287 static inline void hugetlb_dup_vma_private(struct vm_area_struct *vma)
288 {
289 }
290
clear_vma_resv_huge_pages(struct vm_area_struct * vma)291 static inline void clear_vma_resv_huge_pages(struct vm_area_struct *vma)
292 {
293 }
294
hugetlb_total_pages(void)295 static inline unsigned long hugetlb_total_pages(void)
296 {
297 return 0;
298 }
299
hugetlb_folio_mapping_lock_write(struct folio * folio)300 static inline struct address_space *hugetlb_folio_mapping_lock_write(
301 struct folio *folio)
302 {
303 return NULL;
304 }
305
huge_pmd_unshare(struct mm_struct * mm,struct vm_area_struct * vma,unsigned long addr,pte_t * ptep)306 static inline int huge_pmd_unshare(struct mm_struct *mm,
307 struct vm_area_struct *vma,
308 unsigned long addr, pte_t *ptep)
309 {
310 return 0;
311 }
312
adjust_range_if_pmd_sharing_possible(struct vm_area_struct * vma,unsigned long * start,unsigned long * end)313 static inline void adjust_range_if_pmd_sharing_possible(
314 struct vm_area_struct *vma,
315 unsigned long *start, unsigned long *end)
316 {
317 }
318
hugetlb_zap_begin(struct vm_area_struct * vma,unsigned long * start,unsigned long * end)319 static inline void hugetlb_zap_begin(
320 struct vm_area_struct *vma,
321 unsigned long *start, unsigned long *end)
322 {
323 }
324
hugetlb_zap_end(struct vm_area_struct * vma,struct zap_details * details)325 static inline void hugetlb_zap_end(
326 struct vm_area_struct *vma,
327 struct zap_details *details)
328 {
329 }
330
copy_hugetlb_page_range(struct mm_struct * dst,struct mm_struct * src,struct vm_area_struct * dst_vma,struct vm_area_struct * src_vma)331 static inline int copy_hugetlb_page_range(struct mm_struct *dst,
332 struct mm_struct *src,
333 struct vm_area_struct *dst_vma,
334 struct vm_area_struct *src_vma)
335 {
336 BUG();
337 return 0;
338 }
339
move_hugetlb_page_tables(struct vm_area_struct * vma,struct vm_area_struct * new_vma,unsigned long old_addr,unsigned long new_addr,unsigned long len)340 static inline int move_hugetlb_page_tables(struct vm_area_struct *vma,
341 struct vm_area_struct *new_vma,
342 unsigned long old_addr,
343 unsigned long new_addr,
344 unsigned long len)
345 {
346 BUG();
347 return 0;
348 }
349
hugetlb_report_meminfo(struct seq_file * m)350 static inline void hugetlb_report_meminfo(struct seq_file *m)
351 {
352 }
353
hugetlb_report_node_meminfo(char * buf,int len,int nid)354 static inline int hugetlb_report_node_meminfo(char *buf, int len, int nid)
355 {
356 return 0;
357 }
358
hugetlb_show_meminfo_node(int nid)359 static inline void hugetlb_show_meminfo_node(int nid)
360 {
361 }
362
prepare_hugepage_range(struct file * file,unsigned long addr,unsigned long len)363 static inline int prepare_hugepage_range(struct file *file,
364 unsigned long addr, unsigned long len)
365 {
366 return -EINVAL;
367 }
368
hugetlb_vma_lock_read(struct vm_area_struct * vma)369 static inline void hugetlb_vma_lock_read(struct vm_area_struct *vma)
370 {
371 }
372
hugetlb_vma_unlock_read(struct vm_area_struct * vma)373 static inline void hugetlb_vma_unlock_read(struct vm_area_struct *vma)
374 {
375 }
376
hugetlb_vma_lock_write(struct vm_area_struct * vma)377 static inline void hugetlb_vma_lock_write(struct vm_area_struct *vma)
378 {
379 }
380
hugetlb_vma_unlock_write(struct vm_area_struct * vma)381 static inline void hugetlb_vma_unlock_write(struct vm_area_struct *vma)
382 {
383 }
384
hugetlb_vma_trylock_write(struct vm_area_struct * vma)385 static inline int hugetlb_vma_trylock_write(struct vm_area_struct *vma)
386 {
387 return 1;
388 }
389
hugetlb_vma_assert_locked(struct vm_area_struct * vma)390 static inline void hugetlb_vma_assert_locked(struct vm_area_struct *vma)
391 {
392 }
393
is_hugepage_only_range(struct mm_struct * mm,unsigned long addr,unsigned long len)394 static inline int is_hugepage_only_range(struct mm_struct *mm,
395 unsigned long addr, unsigned long len)
396 {
397 return 0;
398 }
399
hugetlb_free_pgd_range(struct mmu_gather * tlb,unsigned long addr,unsigned long end,unsigned long floor,unsigned long ceiling)400 static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
401 unsigned long addr, unsigned long end,
402 unsigned long floor, unsigned long ceiling)
403 {
404 BUG();
405 }
406
407 #ifdef CONFIG_USERFAULTFD
hugetlb_mfill_atomic_pte(pte_t * dst_pte,struct vm_area_struct * dst_vma,unsigned long dst_addr,unsigned long src_addr,uffd_flags_t flags,struct folio ** foliop)408 static inline int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
409 struct vm_area_struct *dst_vma,
410 unsigned long dst_addr,
411 unsigned long src_addr,
412 uffd_flags_t flags,
413 struct folio **foliop)
414 {
415 BUG();
416 return 0;
417 }
418 #endif /* CONFIG_USERFAULTFD */
419
huge_pte_offset(struct mm_struct * mm,unsigned long addr,unsigned long sz)420 static inline pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
421 unsigned long sz)
422 {
423 return NULL;
424 }
425
isolate_hugetlb(struct folio * folio,struct list_head * list)426 static inline bool isolate_hugetlb(struct folio *folio, struct list_head *list)
427 {
428 return false;
429 }
430
get_hwpoison_hugetlb_folio(struct folio * folio,bool * hugetlb,bool unpoison)431 static inline int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison)
432 {
433 return 0;
434 }
435
get_huge_page_for_hwpoison(unsigned long pfn,int flags,bool * migratable_cleared)436 static inline int get_huge_page_for_hwpoison(unsigned long pfn, int flags,
437 bool *migratable_cleared)
438 {
439 return 0;
440 }
441
folio_putback_active_hugetlb(struct folio * folio)442 static inline void folio_putback_active_hugetlb(struct folio *folio)
443 {
444 }
445
move_hugetlb_state(struct folio * old_folio,struct folio * new_folio,int reason)446 static inline void move_hugetlb_state(struct folio *old_folio,
447 struct folio *new_folio, int reason)
448 {
449 }
450
hugetlb_change_protection(struct vm_area_struct * vma,unsigned long address,unsigned long end,pgprot_t newprot,unsigned long cp_flags)451 static inline long hugetlb_change_protection(
452 struct vm_area_struct *vma, unsigned long address,
453 unsigned long end, pgprot_t newprot,
454 unsigned long cp_flags)
455 {
456 return 0;
457 }
458
__unmap_hugepage_range(struct mmu_gather * tlb,struct vm_area_struct * vma,unsigned long start,unsigned long end,struct page * ref_page,zap_flags_t zap_flags)459 static inline void __unmap_hugepage_range(struct mmu_gather *tlb,
460 struct vm_area_struct *vma, unsigned long start,
461 unsigned long end, struct page *ref_page,
462 zap_flags_t zap_flags)
463 {
464 BUG();
465 }
466
hugetlb_fault(struct mm_struct * mm,struct vm_area_struct * vma,unsigned long address,unsigned int flags)467 static inline vm_fault_t hugetlb_fault(struct mm_struct *mm,
468 struct vm_area_struct *vma, unsigned long address,
469 unsigned int flags)
470 {
471 BUG();
472 return 0;
473 }
474
hugetlb_unshare_all_pmds(struct vm_area_struct * vma)475 static inline void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) { }
476
477 #endif /* !CONFIG_HUGETLB_PAGE */
478
479 #ifndef pgd_write
pgd_write(pgd_t pgd)480 static inline int pgd_write(pgd_t pgd)
481 {
482 BUG();
483 return 0;
484 }
485 #endif
486
487 #define HUGETLB_ANON_FILE "anon_hugepage"
488
489 enum {
490 /*
491 * The file will be used as an shm file so shmfs accounting rules
492 * apply
493 */
494 HUGETLB_SHMFS_INODE = 1,
495 /*
496 * The file is being created on the internal vfs mount and shmfs
497 * accounting rules do not apply
498 */
499 HUGETLB_ANONHUGE_INODE = 2,
500 };
501
502 #ifdef CONFIG_HUGETLBFS
503 struct hugetlbfs_sb_info {
504 long max_inodes; /* inodes allowed */
505 long free_inodes; /* inodes free */
506 spinlock_t stat_lock;
507 struct hstate *hstate;
508 struct hugepage_subpool *spool;
509 kuid_t uid;
510 kgid_t gid;
511 umode_t mode;
512 };
513
HUGETLBFS_SB(struct super_block * sb)514 static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
515 {
516 return sb->s_fs_info;
517 }
518
519 struct hugetlbfs_inode_info {
520 struct inode vfs_inode;
521 unsigned int seals;
522 };
523
HUGETLBFS_I(struct inode * inode)524 static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
525 {
526 return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
527 }
528
529 extern const struct vm_operations_struct hugetlb_vm_ops;
530 struct file *hugetlb_file_setup(const char *name, size_t size, vm_flags_t acct,
531 int creat_flags, int page_size_log);
532
is_file_hugepages(const struct file * file)533 static inline bool is_file_hugepages(const struct file *file)
534 {
535 return file->f_op->fop_flags & FOP_HUGE_PAGES;
536 }
537
hstate_inode(struct inode * i)538 static inline struct hstate *hstate_inode(struct inode *i)
539 {
540 return HUGETLBFS_SB(i->i_sb)->hstate;
541 }
542 #else /* !CONFIG_HUGETLBFS */
543
544 #define is_file_hugepages(file) false
545 static inline struct file *
hugetlb_file_setup(const char * name,size_t size,vm_flags_t acctflag,int creat_flags,int page_size_log)546 hugetlb_file_setup(const char *name, size_t size, vm_flags_t acctflag,
547 int creat_flags, int page_size_log)
548 {
549 return ERR_PTR(-ENOSYS);
550 }
551
hstate_inode(struct inode * i)552 static inline struct hstate *hstate_inode(struct inode *i)
553 {
554 return NULL;
555 }
556 #endif /* !CONFIG_HUGETLBFS */
557
558 #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
559 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
560 unsigned long len, unsigned long pgoff,
561 unsigned long flags);
562 #endif /* HAVE_ARCH_HUGETLB_UNMAPPED_AREA */
563
564 unsigned long
565 generic_hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
566 unsigned long len, unsigned long pgoff,
567 unsigned long flags);
568
569 /*
570 * huegtlb page specific state flags. These flags are located in page.private
571 * of the hugetlb head page. Functions created via the below macros should be
572 * used to manipulate these flags.
573 *
574 * HPG_restore_reserve - Set when a hugetlb page consumes a reservation at
575 * allocation time. Cleared when page is fully instantiated. Free
576 * routine checks flag to restore a reservation on error paths.
577 * Synchronization: Examined or modified by code that knows it has
578 * the only reference to page. i.e. After allocation but before use
579 * or when the page is being freed.
580 * HPG_migratable - Set after a newly allocated page is added to the page
581 * cache and/or page tables. Indicates the page is a candidate for
582 * migration.
583 * Synchronization: Initially set after new page allocation with no
584 * locking. When examined and modified during migration processing
585 * (isolate, migrate, putback) the hugetlb_lock is held.
586 * HPG_temporary - Set on a page that is temporarily allocated from the buddy
587 * allocator. Typically used for migration target pages when no pages
588 * are available in the pool. The hugetlb free page path will
589 * immediately free pages with this flag set to the buddy allocator.
590 * Synchronization: Can be set after huge page allocation from buddy when
591 * code knows it has only reference. All other examinations and
592 * modifications require hugetlb_lock.
593 * HPG_freed - Set when page is on the free lists.
594 * Synchronization: hugetlb_lock held for examination and modification.
595 * HPG_vmemmap_optimized - Set when the vmemmap pages of the page are freed.
596 * HPG_raw_hwp_unreliable - Set when the hugetlb page has a hwpoison sub-page
597 * that is not tracked by raw_hwp_page list.
598 */
599 enum hugetlb_page_flags {
600 HPG_restore_reserve = 0,
601 HPG_migratable,
602 HPG_temporary,
603 HPG_freed,
604 HPG_vmemmap_optimized,
605 HPG_raw_hwp_unreliable,
606 __NR_HPAGEFLAGS,
607 };
608
609 /*
610 * Macros to create test, set and clear function definitions for
611 * hugetlb specific page flags.
612 */
613 #ifdef CONFIG_HUGETLB_PAGE
614 #define TESTHPAGEFLAG(uname, flname) \
615 static __always_inline \
616 bool folio_test_hugetlb_##flname(struct folio *folio) \
617 { void *private = &folio->private; \
618 return test_bit(HPG_##flname, private); \
619 } \
620 static inline int HPage##uname(struct page *page) \
621 { return test_bit(HPG_##flname, &(page->private)); }
622
623 #define SETHPAGEFLAG(uname, flname) \
624 static __always_inline \
625 void folio_set_hugetlb_##flname(struct folio *folio) \
626 { void *private = &folio->private; \
627 set_bit(HPG_##flname, private); \
628 } \
629 static inline void SetHPage##uname(struct page *page) \
630 { set_bit(HPG_##flname, &(page->private)); }
631
632 #define CLEARHPAGEFLAG(uname, flname) \
633 static __always_inline \
634 void folio_clear_hugetlb_##flname(struct folio *folio) \
635 { void *private = &folio->private; \
636 clear_bit(HPG_##flname, private); \
637 } \
638 static inline void ClearHPage##uname(struct page *page) \
639 { clear_bit(HPG_##flname, &(page->private)); }
640 #else
641 #define TESTHPAGEFLAG(uname, flname) \
642 static inline bool \
643 folio_test_hugetlb_##flname(struct folio *folio) \
644 { return 0; } \
645 static inline int HPage##uname(struct page *page) \
646 { return 0; }
647
648 #define SETHPAGEFLAG(uname, flname) \
649 static inline void \
650 folio_set_hugetlb_##flname(struct folio *folio) \
651 { } \
652 static inline void SetHPage##uname(struct page *page) \
653 { }
654
655 #define CLEARHPAGEFLAG(uname, flname) \
656 static inline void \
657 folio_clear_hugetlb_##flname(struct folio *folio) \
658 { } \
659 static inline void ClearHPage##uname(struct page *page) \
660 { }
661 #endif
662
663 #define HPAGEFLAG(uname, flname) \
664 TESTHPAGEFLAG(uname, flname) \
665 SETHPAGEFLAG(uname, flname) \
666 CLEARHPAGEFLAG(uname, flname) \
667
668 /*
669 * Create functions associated with hugetlb page flags
670 */
671 HPAGEFLAG(RestoreReserve, restore_reserve)
672 HPAGEFLAG(Migratable, migratable)
673 HPAGEFLAG(Temporary, temporary)
674 HPAGEFLAG(Freed, freed)
675 HPAGEFLAG(VmemmapOptimized, vmemmap_optimized)
676 HPAGEFLAG(RawHwpUnreliable, raw_hwp_unreliable)
677
678 #ifdef CONFIG_HUGETLB_PAGE
679
680 #define HSTATE_NAME_LEN 32
681 /* Defines one hugetlb page size */
682 struct hstate {
683 struct mutex resize_lock;
684 int next_nid_to_alloc;
685 int next_nid_to_free;
686 unsigned int order;
687 unsigned int demote_order;
688 unsigned long mask;
689 unsigned long max_huge_pages;
690 unsigned long nr_huge_pages;
691 unsigned long free_huge_pages;
692 unsigned long resv_huge_pages;
693 unsigned long surplus_huge_pages;
694 unsigned long nr_overcommit_huge_pages;
695 struct list_head hugepage_activelist;
696 struct list_head hugepage_freelists[MAX_NUMNODES];
697 unsigned int max_huge_pages_node[MAX_NUMNODES];
698 unsigned int nr_huge_pages_node[MAX_NUMNODES];
699 unsigned int free_huge_pages_node[MAX_NUMNODES];
700 unsigned int surplus_huge_pages_node[MAX_NUMNODES];
701 #ifdef CONFIG_CGROUP_HUGETLB
702 /* cgroup control files */
703 struct cftype cgroup_files_dfl[8];
704 struct cftype cgroup_files_legacy[10];
705 #endif
706 char name[HSTATE_NAME_LEN];
707 };
708
709 struct huge_bootmem_page {
710 struct list_head list;
711 struct hstate *hstate;
712 };
713
714 int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list);
715 struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
716 unsigned long addr, int avoid_reserve);
717 struct folio *alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid,
718 nodemask_t *nmask, gfp_t gfp_mask,
719 bool allow_alloc_fallback);
720 int hugetlb_add_to_page_cache(struct folio *folio, struct address_space *mapping,
721 pgoff_t idx);
722 void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
723 unsigned long address, struct folio *folio);
724
725 /* arch callback */
726 int __init __alloc_bootmem_huge_page(struct hstate *h, int nid);
727 int __init alloc_bootmem_huge_page(struct hstate *h, int nid);
728 bool __init hugetlb_node_alloc_supported(void);
729
730 void __init hugetlb_add_hstate(unsigned order);
731 bool __init arch_hugetlb_valid_size(unsigned long size);
732 struct hstate *size_to_hstate(unsigned long size);
733
734 #ifndef HUGE_MAX_HSTATE
735 #define HUGE_MAX_HSTATE 1
736 #endif
737
738 extern struct hstate hstates[HUGE_MAX_HSTATE];
739 extern unsigned int default_hstate_idx;
740
741 #define default_hstate (hstates[default_hstate_idx])
742
hugetlb_folio_subpool(struct folio * folio)743 static inline struct hugepage_subpool *hugetlb_folio_subpool(struct folio *folio)
744 {
745 return folio->_hugetlb_subpool;
746 }
747
hugetlb_set_folio_subpool(struct folio * folio,struct hugepage_subpool * subpool)748 static inline void hugetlb_set_folio_subpool(struct folio *folio,
749 struct hugepage_subpool *subpool)
750 {
751 folio->_hugetlb_subpool = subpool;
752 }
753
hstate_file(struct file * f)754 static inline struct hstate *hstate_file(struct file *f)
755 {
756 return hstate_inode(file_inode(f));
757 }
758
hstate_sizelog(int page_size_log)759 static inline struct hstate *hstate_sizelog(int page_size_log)
760 {
761 if (!page_size_log)
762 return &default_hstate;
763
764 if (page_size_log < BITS_PER_LONG)
765 return size_to_hstate(1UL << page_size_log);
766
767 return NULL;
768 }
769
hstate_vma(struct vm_area_struct * vma)770 static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
771 {
772 return hstate_file(vma->vm_file);
773 }
774
huge_page_size(const struct hstate * h)775 static inline unsigned long huge_page_size(const struct hstate *h)
776 {
777 return (unsigned long)PAGE_SIZE << h->order;
778 }
779
780 extern unsigned long vma_kernel_pagesize(struct vm_area_struct *vma);
781
782 extern unsigned long vma_mmu_pagesize(struct vm_area_struct *vma);
783
huge_page_mask(struct hstate * h)784 static inline unsigned long huge_page_mask(struct hstate *h)
785 {
786 return h->mask;
787 }
788
huge_page_order(struct hstate * h)789 static inline unsigned int huge_page_order(struct hstate *h)
790 {
791 return h->order;
792 }
793
huge_page_shift(struct hstate * h)794 static inline unsigned huge_page_shift(struct hstate *h)
795 {
796 return h->order + PAGE_SHIFT;
797 }
798
hstate_is_gigantic(struct hstate * h)799 static inline bool hstate_is_gigantic(struct hstate *h)
800 {
801 return huge_page_order(h) > MAX_PAGE_ORDER;
802 }
803
pages_per_huge_page(const struct hstate * h)804 static inline unsigned int pages_per_huge_page(const struct hstate *h)
805 {
806 return 1 << h->order;
807 }
808
blocks_per_huge_page(struct hstate * h)809 static inline unsigned int blocks_per_huge_page(struct hstate *h)
810 {
811 return huge_page_size(h) / 512;
812 }
813
filemap_lock_hugetlb_folio(struct hstate * h,struct address_space * mapping,pgoff_t idx)814 static inline struct folio *filemap_lock_hugetlb_folio(struct hstate *h,
815 struct address_space *mapping, pgoff_t idx)
816 {
817 return filemap_lock_folio(mapping, idx << huge_page_order(h));
818 }
819
820 #include <asm/hugetlb.h>
821
822 #ifndef is_hugepage_only_range
is_hugepage_only_range(struct mm_struct * mm,unsigned long addr,unsigned long len)823 static inline int is_hugepage_only_range(struct mm_struct *mm,
824 unsigned long addr, unsigned long len)
825 {
826 return 0;
827 }
828 #define is_hugepage_only_range is_hugepage_only_range
829 #endif
830
831 #ifndef arch_clear_hugetlb_flags
arch_clear_hugetlb_flags(struct folio * folio)832 static inline void arch_clear_hugetlb_flags(struct folio *folio) { }
833 #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
834 #endif
835
836 #ifndef arch_make_huge_pte
arch_make_huge_pte(pte_t entry,unsigned int shift,vm_flags_t flags)837 static inline pte_t arch_make_huge_pte(pte_t entry, unsigned int shift,
838 vm_flags_t flags)
839 {
840 return pte_mkhuge(entry);
841 }
842 #endif
843
folio_hstate(struct folio * folio)844 static inline struct hstate *folio_hstate(struct folio *folio)
845 {
846 VM_BUG_ON_FOLIO(!folio_test_hugetlb(folio), folio);
847 return size_to_hstate(folio_size(folio));
848 }
849
hstate_index_to_shift(unsigned index)850 static inline unsigned hstate_index_to_shift(unsigned index)
851 {
852 return hstates[index].order + PAGE_SHIFT;
853 }
854
hstate_index(struct hstate * h)855 static inline int hstate_index(struct hstate *h)
856 {
857 return h - hstates;
858 }
859
860 int dissolve_free_hugetlb_folio(struct folio *folio);
861 int dissolve_free_hugetlb_folios(unsigned long start_pfn,
862 unsigned long end_pfn);
863
864 #ifdef CONFIG_MEMORY_FAILURE
865 extern void folio_clear_hugetlb_hwpoison(struct folio *folio);
866 #else
folio_clear_hugetlb_hwpoison(struct folio * folio)867 static inline void folio_clear_hugetlb_hwpoison(struct folio *folio)
868 {
869 }
870 #endif
871
872 #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
873 #ifndef arch_hugetlb_migration_supported
arch_hugetlb_migration_supported(struct hstate * h)874 static inline bool arch_hugetlb_migration_supported(struct hstate *h)
875 {
876 if ((huge_page_shift(h) == PMD_SHIFT) ||
877 (huge_page_shift(h) == PUD_SHIFT) ||
878 (huge_page_shift(h) == PGDIR_SHIFT))
879 return true;
880 else
881 return false;
882 }
883 #endif
884 #else
arch_hugetlb_migration_supported(struct hstate * h)885 static inline bool arch_hugetlb_migration_supported(struct hstate *h)
886 {
887 return false;
888 }
889 #endif
890
hugepage_migration_supported(struct hstate * h)891 static inline bool hugepage_migration_supported(struct hstate *h)
892 {
893 return arch_hugetlb_migration_supported(h);
894 }
895
896 /*
897 * Movability check is different as compared to migration check.
898 * It determines whether or not a huge page should be placed on
899 * movable zone or not. Movability of any huge page should be
900 * required only if huge page size is supported for migration.
901 * There won't be any reason for the huge page to be movable if
902 * it is not migratable to start with. Also the size of the huge
903 * page should be large enough to be placed under a movable zone
904 * and still feasible enough to be migratable. Just the presence
905 * in movable zone does not make the migration feasible.
906 *
907 * So even though large huge page sizes like the gigantic ones
908 * are migratable they should not be movable because its not
909 * feasible to migrate them from movable zone.
910 */
hugepage_movable_supported(struct hstate * h)911 static inline bool hugepage_movable_supported(struct hstate *h)
912 {
913 if (!hugepage_migration_supported(h))
914 return false;
915
916 if (hstate_is_gigantic(h))
917 return false;
918 return true;
919 }
920
921 /* Movability of hugepages depends on migration support. */
htlb_alloc_mask(struct hstate * h)922 static inline gfp_t htlb_alloc_mask(struct hstate *h)
923 {
924 if (hugepage_movable_supported(h))
925 return GFP_HIGHUSER_MOVABLE;
926 else
927 return GFP_HIGHUSER;
928 }
929
htlb_modify_alloc_mask(struct hstate * h,gfp_t gfp_mask)930 static inline gfp_t htlb_modify_alloc_mask(struct hstate *h, gfp_t gfp_mask)
931 {
932 gfp_t modified_mask = htlb_alloc_mask(h);
933
934 /* Some callers might want to enforce node */
935 modified_mask |= (gfp_mask & __GFP_THISNODE);
936
937 modified_mask |= (gfp_mask & __GFP_NOWARN);
938
939 return modified_mask;
940 }
941
htlb_allow_alloc_fallback(int reason)942 static inline bool htlb_allow_alloc_fallback(int reason)
943 {
944 bool allowed_fallback = false;
945
946 /*
947 * Note: the memory offline, memory failure and migration syscalls will
948 * be allowed to fallback to other nodes due to lack of a better chioce,
949 * that might break the per-node hugetlb pool. While other cases will
950 * set the __GFP_THISNODE to avoid breaking the per-node hugetlb pool.
951 */
952 switch (reason) {
953 case MR_MEMORY_HOTPLUG:
954 case MR_MEMORY_FAILURE:
955 case MR_SYSCALL:
956 case MR_MEMPOLICY_MBIND:
957 allowed_fallback = true;
958 break;
959 default:
960 break;
961 }
962
963 return allowed_fallback;
964 }
965
huge_pte_lockptr(struct hstate * h,struct mm_struct * mm,pte_t * pte)966 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
967 struct mm_struct *mm, pte_t *pte)
968 {
969 if (huge_page_size(h) == PMD_SIZE)
970 return pmd_lockptr(mm, (pmd_t *) pte);
971 VM_BUG_ON(huge_page_size(h) == PAGE_SIZE);
972 return &mm->page_table_lock;
973 }
974
975 #ifndef hugepages_supported
976 /*
977 * Some platform decide whether they support huge pages at boot
978 * time. Some of them, such as powerpc, set HPAGE_SHIFT to 0
979 * when there is no such support
980 */
981 #define hugepages_supported() (HPAGE_SHIFT != 0)
982 #endif
983
984 void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm);
985
hugetlb_count_init(struct mm_struct * mm)986 static inline void hugetlb_count_init(struct mm_struct *mm)
987 {
988 atomic_long_set(&mm->hugetlb_usage, 0);
989 }
990
hugetlb_count_add(long l,struct mm_struct * mm)991 static inline void hugetlb_count_add(long l, struct mm_struct *mm)
992 {
993 atomic_long_add(l, &mm->hugetlb_usage);
994 }
995
hugetlb_count_sub(long l,struct mm_struct * mm)996 static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
997 {
998 atomic_long_sub(l, &mm->hugetlb_usage);
999 }
1000
1001 #ifndef huge_ptep_modify_prot_start
1002 #define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
huge_ptep_modify_prot_start(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep)1003 static inline pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
1004 unsigned long addr, pte_t *ptep)
1005 {
1006 return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
1007 }
1008 #endif
1009
1010 #ifndef huge_ptep_modify_prot_commit
1011 #define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
huge_ptep_modify_prot_commit(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep,pte_t old_pte,pte_t pte)1012 static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
1013 unsigned long addr, pte_t *ptep,
1014 pte_t old_pte, pte_t pte)
1015 {
1016 unsigned long psize = huge_page_size(hstate_vma(vma));
1017
1018 set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
1019 }
1020 #endif
1021
1022 #ifdef CONFIG_NUMA
1023 void hugetlb_register_node(struct node *node);
1024 void hugetlb_unregister_node(struct node *node);
1025 #endif
1026
1027 /*
1028 * Check if a given raw @page in a hugepage is HWPOISON.
1029 */
1030 bool is_raw_hwpoison_page_in_hugepage(struct page *page);
1031
1032 #else /* CONFIG_HUGETLB_PAGE */
1033 struct hstate {};
1034
1035 static inline struct hugepage_subpool *hugetlb_folio_subpool(struct folio *folio)
1036 {
1037 return NULL;
1038 }
1039
1040 static inline struct folio *filemap_lock_hugetlb_folio(struct hstate *h,
1041 struct address_space *mapping, pgoff_t idx)
1042 {
1043 return NULL;
1044 }
1045
1046 static inline int isolate_or_dissolve_huge_page(struct page *page,
1047 struct list_head *list)
1048 {
1049 return -ENOMEM;
1050 }
1051
1052 static inline struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
1053 unsigned long addr,
1054 int avoid_reserve)
1055 {
1056 return NULL;
1057 }
1058
1059 static inline struct folio *
1060 alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid,
1061 nodemask_t *nmask, gfp_t gfp_mask,
1062 bool allow_alloc_fallback)
1063 {
1064 return NULL;
1065 }
1066
1067 static inline int __alloc_bootmem_huge_page(struct hstate *h)
1068 {
1069 return 0;
1070 }
1071
1072 static inline struct hstate *hstate_file(struct file *f)
1073 {
1074 return NULL;
1075 }
1076
1077 static inline struct hstate *hstate_sizelog(int page_size_log)
1078 {
1079 return NULL;
1080 }
1081
1082 static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
1083 {
1084 return NULL;
1085 }
1086
1087 static inline struct hstate *folio_hstate(struct folio *folio)
1088 {
1089 return NULL;
1090 }
1091
1092 static inline struct hstate *size_to_hstate(unsigned long size)
1093 {
1094 return NULL;
1095 }
1096
1097 static inline unsigned long huge_page_size(struct hstate *h)
1098 {
1099 return PAGE_SIZE;
1100 }
1101
1102 static inline unsigned long huge_page_mask(struct hstate *h)
1103 {
1104 return PAGE_MASK;
1105 }
1106
1107 static inline unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
1108 {
1109 return PAGE_SIZE;
1110 }
1111
1112 static inline unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
1113 {
1114 return PAGE_SIZE;
1115 }
1116
1117 static inline unsigned int huge_page_order(struct hstate *h)
1118 {
1119 return 0;
1120 }
1121
1122 static inline unsigned int huge_page_shift(struct hstate *h)
1123 {
1124 return PAGE_SHIFT;
1125 }
1126
1127 static inline bool hstate_is_gigantic(struct hstate *h)
1128 {
1129 return false;
1130 }
1131
1132 static inline unsigned int pages_per_huge_page(struct hstate *h)
1133 {
1134 return 1;
1135 }
1136
1137 static inline unsigned hstate_index_to_shift(unsigned index)
1138 {
1139 return 0;
1140 }
1141
1142 static inline int hstate_index(struct hstate *h)
1143 {
1144 return 0;
1145 }
1146
1147 static inline int dissolve_free_hugetlb_folio(struct folio *folio)
1148 {
1149 return 0;
1150 }
1151
1152 static inline int dissolve_free_hugetlb_folios(unsigned long start_pfn,
1153 unsigned long end_pfn)
1154 {
1155 return 0;
1156 }
1157
1158 static inline bool hugepage_migration_supported(struct hstate *h)
1159 {
1160 return false;
1161 }
1162
1163 static inline bool hugepage_movable_supported(struct hstate *h)
1164 {
1165 return false;
1166 }
1167
1168 static inline gfp_t htlb_alloc_mask(struct hstate *h)
1169 {
1170 return 0;
1171 }
1172
1173 static inline gfp_t htlb_modify_alloc_mask(struct hstate *h, gfp_t gfp_mask)
1174 {
1175 return 0;
1176 }
1177
1178 static inline bool htlb_allow_alloc_fallback(int reason)
1179 {
1180 return false;
1181 }
1182
1183 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
1184 struct mm_struct *mm, pte_t *pte)
1185 {
1186 return &mm->page_table_lock;
1187 }
1188
1189 static inline void hugetlb_count_init(struct mm_struct *mm)
1190 {
1191 }
1192
1193 static inline void hugetlb_report_usage(struct seq_file *f, struct mm_struct *m)
1194 {
1195 }
1196
1197 static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
1198 {
1199 }
1200
1201 static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
1202 unsigned long addr, pte_t *ptep)
1203 {
1204 #ifdef CONFIG_MMU
1205 return ptep_get(ptep);
1206 #else
1207 return *ptep;
1208 #endif
1209 }
1210
1211 static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
1212 pte_t *ptep, pte_t pte, unsigned long sz)
1213 {
1214 }
1215
1216 static inline void hugetlb_register_node(struct node *node)
1217 {
1218 }
1219
1220 static inline void hugetlb_unregister_node(struct node *node)
1221 {
1222 }
1223
1224 static inline bool hugetlbfs_pagecache_present(
1225 struct hstate *h, struct vm_area_struct *vma, unsigned long address)
1226 {
1227 return false;
1228 }
1229 #endif /* CONFIG_HUGETLB_PAGE */
1230
huge_pte_lock(struct hstate * h,struct mm_struct * mm,pte_t * pte)1231 static inline spinlock_t *huge_pte_lock(struct hstate *h,
1232 struct mm_struct *mm, pte_t *pte)
1233 {
1234 spinlock_t *ptl;
1235
1236 ptl = huge_pte_lockptr(h, mm, pte);
1237 spin_lock(ptl);
1238 return ptl;
1239 }
1240
1241 #if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_CMA)
1242 extern void __init hugetlb_cma_reserve(int order);
1243 #else
hugetlb_cma_reserve(int order)1244 static inline __init void hugetlb_cma_reserve(int order)
1245 {
1246 }
1247 #endif
1248
1249 #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
hugetlb_pmd_shared(pte_t * pte)1250 static inline bool hugetlb_pmd_shared(pte_t *pte)
1251 {
1252 return page_count(virt_to_page(pte)) > 1;
1253 }
1254 #else
hugetlb_pmd_shared(pte_t * pte)1255 static inline bool hugetlb_pmd_shared(pte_t *pte)
1256 {
1257 return false;
1258 }
1259 #endif
1260
1261 bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr);
1262
1263 #ifndef __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE
1264 /*
1265 * ARCHes with special requirements for evicting HUGETLB backing TLB entries can
1266 * implement this.
1267 */
1268 #define flush_hugetlb_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
1269 #endif
1270
__vma_shareable_lock(struct vm_area_struct * vma)1271 static inline bool __vma_shareable_lock(struct vm_area_struct *vma)
1272 {
1273 return (vma->vm_flags & VM_MAYSHARE) && vma->vm_private_data;
1274 }
1275
1276 bool __vma_private_lock(struct vm_area_struct *vma);
1277
1278 /*
1279 * Safe version of huge_pte_offset() to check the locks. See comments
1280 * above huge_pte_offset().
1281 */
1282 static inline pte_t *
hugetlb_walk(struct vm_area_struct * vma,unsigned long addr,unsigned long sz)1283 hugetlb_walk(struct vm_area_struct *vma, unsigned long addr, unsigned long sz)
1284 {
1285 #if defined(CONFIG_HUGETLB_PAGE) && \
1286 defined(CONFIG_ARCH_WANT_HUGE_PMD_SHARE) && defined(CONFIG_LOCKDEP)
1287 struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
1288
1289 /*
1290 * If pmd sharing possible, locking needed to safely walk the
1291 * hugetlb pgtables. More information can be found at the comment
1292 * above huge_pte_offset() in the same file.
1293 *
1294 * NOTE: lockdep_is_held() is only defined with CONFIG_LOCKDEP.
1295 */
1296 if (__vma_shareable_lock(vma))
1297 WARN_ON_ONCE(!lockdep_is_held(&vma_lock->rw_sema) &&
1298 !lockdep_is_held(
1299 &vma->vm_file->f_mapping->i_mmap_rwsem));
1300 #endif
1301 return huge_pte_offset(vma->vm_mm, addr, sz);
1302 }
1303
1304 #endif /* _LINUX_HUGETLB_H */
1305