1 /* SPDX-License-Identifier: GPL-2.0 */
5 * Declarations for Reverse Mapping functions in mm/rmap.c
8 #include <linux/list.h>
9 #include <linux/slab.h>
11 #include <linux/rwsem.h>
12 #include <linux/memcontrol.h>
13 #include <linux/highmem.h>
14 #include <linux/pagemap.h>
15 #include <linux/memremap.h>
18 * The anon_vma heads a list of private "related" vmas, to scan if
19 * an anonymous page pointing to this anon_vma needs to be unmapped:
20 * the vmas on the list will be related by forking, or by splitting.
22 * Since vmas come and go as they are split and merged (particularly
23 * in mprotect), the mapping field of an anonymous page cannot point
24 * directly to a vma: instead it points to an anon_vma, on whose list
25 * the related vmas can be easily linked or unlinked.
27 * After unlinking the last vma on the list, we must garbage collect
28 * the anon_vma object itself: we're guaranteed no page can be
29 * pointing to this anon_vma once its vma list is empty.
32 struct anon_vma *root; /* Root of this anon_vma tree */
33 struct rw_semaphore rwsem; /* W: modification, R: walking the list */
35 * The refcount is taken on an anon_vma when there is no
36 * guarantee that the vma of page tables will exist for
37 * the duration of the operation. A caller that takes
38 * the reference is responsible for clearing up the
39 * anon_vma if they are the last user on release
44 * Count of child anon_vmas. Equals to the count of all anon_vmas that
45 * have ->parent pointing to this one, including itself.
47 * This counter is used for making decision about reusing anon_vma
48 * instead of forking new one. See comments in function anon_vma_clone.
50 unsigned long num_children;
51 /* Count of VMAs whose ->anon_vma pointer points to this object. */
52 unsigned long num_active_vmas;
54 struct anon_vma *parent; /* Parent of this anon_vma */
57 * NOTE: the LSB of the rb_root.rb_node is set by
58 * mm_take_all_locks() _after_ taking the above lock. So the
59 * rb_root must only be read/written after taking the above lock
60 * to be sure to see a valid next pointer. The LSB bit itself
61 * is serialized by a system wide lock only visible to
62 * mm_take_all_locks() (mm_all_locks_mutex).
65 /* Interval tree of private "related" vmas */
66 struct rb_root_cached rb_root;
70 * The copy-on-write semantics of fork mean that an anon_vma
71 * can become associated with multiple processes. Furthermore,
72 * each child process will have its own anon_vma, where new
73 * pages for that process are instantiated.
75 * This structure allows us to find the anon_vmas associated
76 * with a VMA, or the VMAs associated with an anon_vma.
77 * The "same_vma" list contains the anon_vma_chains linking
78 * all the anon_vmas associated with this VMA.
79 * The "rb" field indexes on an interval tree the anon_vma_chains
80 * which link all the VMAs associated with this anon_vma.
82 struct anon_vma_chain {
83 struct vm_area_struct *vma;
84 struct anon_vma *anon_vma;
85 struct list_head same_vma; /* locked by mmap_lock & page_table_lock */
86 struct rb_node rb; /* locked by anon_vma->rwsem */
87 unsigned long rb_subtree_last;
88 #ifdef CONFIG_DEBUG_VM_RB
89 unsigned long cached_vma_start, cached_vma_last;
94 TTU_SPLIT_HUGE_PMD = 0x4, /* split huge PMD if any */
95 TTU_IGNORE_MLOCK = 0x8, /* ignore mlock */
96 TTU_SYNC = 0x10, /* avoid racy checks with PVMW_SYNC */
97 TTU_HWPOISON = 0x20, /* do convert pte to hwpoison entry */
98 TTU_BATCH_FLUSH = 0x40, /* Batch TLB flushes where possible
99 * and caller guarantees they will
100 * do a final flush if necessary */
101 TTU_RMAP_LOCKED = 0x80, /* do not grab rmap lock:
106 static inline void get_anon_vma(struct anon_vma *anon_vma)
108 atomic_inc(&anon_vma->refcount);
111 void __put_anon_vma(struct anon_vma *anon_vma);
113 static inline void put_anon_vma(struct anon_vma *anon_vma)
115 if (atomic_dec_and_test(&anon_vma->refcount))
116 __put_anon_vma(anon_vma);
119 static inline void anon_vma_lock_write(struct anon_vma *anon_vma)
121 down_write(&anon_vma->root->rwsem);
124 static inline int anon_vma_trylock_write(struct anon_vma *anon_vma)
126 return down_write_trylock(&anon_vma->root->rwsem);
129 static inline void anon_vma_unlock_write(struct anon_vma *anon_vma)
131 up_write(&anon_vma->root->rwsem);
134 static inline void anon_vma_lock_read(struct anon_vma *anon_vma)
136 down_read(&anon_vma->root->rwsem);
139 static inline int anon_vma_trylock_read(struct anon_vma *anon_vma)
141 return down_read_trylock(&anon_vma->root->rwsem);
144 static inline void anon_vma_unlock_read(struct anon_vma *anon_vma)
146 up_read(&anon_vma->root->rwsem);
151 * anon_vma helper functions.
153 void anon_vma_init(void); /* create anon_vma_cachep */
154 int __anon_vma_prepare(struct vm_area_struct *);
155 void unlink_anon_vmas(struct vm_area_struct *);
156 int anon_vma_clone(struct vm_area_struct *, struct vm_area_struct *);
157 int anon_vma_fork(struct vm_area_struct *, struct vm_area_struct *);
159 static inline int anon_vma_prepare(struct vm_area_struct *vma)
161 if (likely(vma->anon_vma))
164 return __anon_vma_prepare(vma);
167 static inline void anon_vma_merge(struct vm_area_struct *vma,
168 struct vm_area_struct *next)
170 VM_BUG_ON_VMA(vma->anon_vma != next->anon_vma, vma);
171 unlink_anon_vmas(next);
174 struct anon_vma *folio_get_anon_vma(struct folio *folio);
176 /* RMAP flags, currently only relevant for some anon rmap operations. */
177 typedef int __bitwise rmap_t;
180 * No special request: A mapped anonymous (sub)page is possibly shared between
183 #define RMAP_NONE ((__force rmap_t)0)
185 /* The anonymous (sub)page is exclusive to a single process. */
186 #define RMAP_EXCLUSIVE ((__force rmap_t)BIT(0))
189 * Internally, we're using an enum to specify the granularity. We make the
190 * compiler emit specialized code for each granularity.
197 static inline void __folio_rmap_sanity_checks(struct folio *folio,
198 struct page *page, int nr_pages, enum rmap_level level)
200 /* hugetlb folios are handled separately. */
201 VM_WARN_ON_FOLIO(folio_test_hugetlb(folio), folio);
204 * TODO: we get driver-allocated folios that have nothing to do with
205 * the rmap using vm_insert_page(); therefore, we cannot assume that
206 * folio_test_large_rmappable() holds for large folios. We should
207 * handle any desired mapcount+stats accounting for these folios in
208 * VM_MIXEDMAP VMAs separately, and then sanity-check here that
209 * we really only get rmappable folios.
212 VM_WARN_ON_ONCE(nr_pages <= 0);
213 VM_WARN_ON_FOLIO(page_folio(page) != folio, folio);
214 VM_WARN_ON_FOLIO(page_folio(page + nr_pages - 1) != folio, folio);
221 * We don't support folios larger than a single PMD yet. So
222 * when RMAP_LEVEL_PMD is set, we assume that we are creating
223 * a single "entire" mapping of the folio.
225 VM_WARN_ON_FOLIO(folio_nr_pages(folio) != HPAGE_PMD_NR, folio);
226 VM_WARN_ON_FOLIO(nr_pages != HPAGE_PMD_NR, folio);
229 VM_WARN_ON_ONCE(true);
234 * rmap interfaces called when adding or removing pte of page
236 void folio_move_anon_rmap(struct folio *, struct vm_area_struct *);
237 void folio_add_anon_rmap_ptes(struct folio *, struct page *, int nr_pages,
238 struct vm_area_struct *, unsigned long address, rmap_t flags);
239 #define folio_add_anon_rmap_pte(folio, page, vma, address, flags) \
240 folio_add_anon_rmap_ptes(folio, page, 1, vma, address, flags)
241 void folio_add_anon_rmap_pmd(struct folio *, struct page *,
242 struct vm_area_struct *, unsigned long address, rmap_t flags);
243 void folio_add_new_anon_rmap(struct folio *, struct vm_area_struct *,
244 unsigned long address);
245 void folio_add_file_rmap_ptes(struct folio *, struct page *, int nr_pages,
246 struct vm_area_struct *);
247 #define folio_add_file_rmap_pte(folio, page, vma) \
248 folio_add_file_rmap_ptes(folio, page, 1, vma)
249 void folio_add_file_rmap_pmd(struct folio *, struct page *,
250 struct vm_area_struct *);
251 void folio_remove_rmap_ptes(struct folio *, struct page *, int nr_pages,
252 struct vm_area_struct *);
253 #define folio_remove_rmap_pte(folio, page, vma) \
254 folio_remove_rmap_ptes(folio, page, 1, vma)
255 void folio_remove_rmap_pmd(struct folio *, struct page *,
256 struct vm_area_struct *);
258 void hugetlb_add_anon_rmap(struct folio *, struct vm_area_struct *,
259 unsigned long address, rmap_t flags);
260 void hugetlb_add_new_anon_rmap(struct folio *, struct vm_area_struct *,
261 unsigned long address);
263 /* See folio_try_dup_anon_rmap_*() */
264 static inline int hugetlb_try_dup_anon_rmap(struct folio *folio,
265 struct vm_area_struct *vma)
267 VM_WARN_ON_FOLIO(!folio_test_hugetlb(folio), folio);
268 VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio);
270 if (PageAnonExclusive(&folio->page)) {
271 if (unlikely(folio_needs_cow_for_dma(vma, folio)))
273 ClearPageAnonExclusive(&folio->page);
275 atomic_inc(&folio->_entire_mapcount);
279 /* See folio_try_share_anon_rmap_*() */
280 static inline int hugetlb_try_share_anon_rmap(struct folio *folio)
282 VM_WARN_ON_FOLIO(!folio_test_hugetlb(folio), folio);
283 VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio);
284 VM_WARN_ON_FOLIO(!PageAnonExclusive(&folio->page), folio);
286 /* Paired with the memory barrier in try_grab_folio(). */
287 if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
290 if (unlikely(folio_maybe_dma_pinned(folio)))
292 ClearPageAnonExclusive(&folio->page);
295 * This is conceptually a smp_wmb() paired with the smp_rmb() in
296 * gup_must_unshare().
298 if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
299 smp_mb__after_atomic();
303 static inline void hugetlb_add_file_rmap(struct folio *folio)
305 VM_WARN_ON_FOLIO(!folio_test_hugetlb(folio), folio);
306 VM_WARN_ON_FOLIO(folio_test_anon(folio), folio);
308 atomic_inc(&folio->_entire_mapcount);
311 static inline void hugetlb_remove_rmap(struct folio *folio)
313 VM_WARN_ON_FOLIO(!folio_test_hugetlb(folio), folio);
315 atomic_dec(&folio->_entire_mapcount);
318 static __always_inline void __folio_dup_file_rmap(struct folio *folio,
319 struct page *page, int nr_pages, enum rmap_level level)
321 __folio_rmap_sanity_checks(folio, page, nr_pages, level);
326 atomic_inc(&page->_mapcount);
327 } while (page++, --nr_pages > 0);
330 atomic_inc(&folio->_entire_mapcount);
336 * folio_dup_file_rmap_ptes - duplicate PTE mappings of a page range of a folio
337 * @folio: The folio to duplicate the mappings of
338 * @page: The first page to duplicate the mappings of
339 * @nr_pages: The number of pages of which the mapping will be duplicated
341 * The page range of the folio is defined by [page, page + nr_pages)
343 * The caller needs to hold the page table lock.
345 static inline void folio_dup_file_rmap_ptes(struct folio *folio,
346 struct page *page, int nr_pages)
348 __folio_dup_file_rmap(folio, page, nr_pages, RMAP_LEVEL_PTE);
350 #define folio_dup_file_rmap_pte(folio, page) \
351 folio_dup_file_rmap_ptes(folio, page, 1)
354 * folio_dup_file_rmap_pmd - duplicate a PMD mapping of a page range of a folio
355 * @folio: The folio to duplicate the mapping of
356 * @page: The first page to duplicate the mapping of
358 * The page range of the folio is defined by [page, page + HPAGE_PMD_NR)
360 * The caller needs to hold the page table lock.
362 static inline void folio_dup_file_rmap_pmd(struct folio *folio,
365 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
366 __folio_dup_file_rmap(folio, page, HPAGE_PMD_NR, RMAP_LEVEL_PTE);
372 static __always_inline int __folio_try_dup_anon_rmap(struct folio *folio,
373 struct page *page, int nr_pages, struct vm_area_struct *src_vma,
374 enum rmap_level level)
379 VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio);
380 __folio_rmap_sanity_checks(folio, page, nr_pages, level);
383 * If this folio may have been pinned by the parent process,
384 * don't allow to duplicate the mappings but instead require to e.g.,
385 * copy the subpage immediately for the child so that we'll always
386 * guarantee the pinned folio won't be randomly replaced in the
387 * future on write faults.
389 maybe_pinned = likely(!folio_is_device_private(folio)) &&
390 unlikely(folio_needs_cow_for_dma(src_vma, folio));
393 * No need to check+clear for already shared PTEs/PMDs of the
394 * folio. But if any page is PageAnonExclusive, we must fallback to
395 * copying if the folio maybe pinned.
399 if (unlikely(maybe_pinned)) {
400 for (i = 0; i < nr_pages; i++)
401 if (PageAnonExclusive(page + i))
405 if (PageAnonExclusive(page))
406 ClearPageAnonExclusive(page);
407 atomic_inc(&page->_mapcount);
408 } while (page++, --nr_pages > 0);
411 if (PageAnonExclusive(page)) {
412 if (unlikely(maybe_pinned))
414 ClearPageAnonExclusive(page);
416 atomic_inc(&folio->_entire_mapcount);
423 * folio_try_dup_anon_rmap_ptes - try duplicating PTE mappings of a page range
425 * @folio: The folio to duplicate the mappings of
426 * @page: The first page to duplicate the mappings of
427 * @nr_pages: The number of pages of which the mapping will be duplicated
428 * @src_vma: The vm area from which the mappings are duplicated
430 * The page range of the folio is defined by [page, page + nr_pages)
432 * The caller needs to hold the page table lock and the
433 * vma->vma_mm->write_protect_seq.
435 * Duplicating the mappings can only fail if the folio may be pinned; device
436 * private folios cannot get pinned and consequently this function cannot fail
439 * If duplicating the mappings succeeded, the duplicated PTEs have to be R/O in
440 * the parent and the child. They must *not* be writable after this call
443 * Returns 0 if duplicating the mappings succeeded. Returns -EBUSY otherwise.
445 static inline int folio_try_dup_anon_rmap_ptes(struct folio *folio,
446 struct page *page, int nr_pages, struct vm_area_struct *src_vma)
448 return __folio_try_dup_anon_rmap(folio, page, nr_pages, src_vma,
451 #define folio_try_dup_anon_rmap_pte(folio, page, vma) \
452 folio_try_dup_anon_rmap_ptes(folio, page, 1, vma)
455 * folio_try_dup_anon_rmap_pmd - try duplicating a PMD mapping of a page range
457 * @folio: The folio to duplicate the mapping of
458 * @page: The first page to duplicate the mapping of
459 * @src_vma: The vm area from which the mapping is duplicated
461 * The page range of the folio is defined by [page, page + HPAGE_PMD_NR)
463 * The caller needs to hold the page table lock and the
464 * vma->vma_mm->write_protect_seq.
466 * Duplicating the mapping can only fail if the folio may be pinned; device
467 * private folios cannot get pinned and consequently this function cannot fail
470 * If duplicating the mapping succeeds, the duplicated PMD has to be R/O in
471 * the parent and the child. They must *not* be writable after this call
474 * Returns 0 if duplicating the mapping succeeded. Returns -EBUSY otherwise.
476 static inline int folio_try_dup_anon_rmap_pmd(struct folio *folio,
477 struct page *page, struct vm_area_struct *src_vma)
479 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
480 return __folio_try_dup_anon_rmap(folio, page, HPAGE_PMD_NR, src_vma,
488 static __always_inline int __folio_try_share_anon_rmap(struct folio *folio,
489 struct page *page, int nr_pages, enum rmap_level level)
491 VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio);
492 VM_WARN_ON_FOLIO(!PageAnonExclusive(page), folio);
493 __folio_rmap_sanity_checks(folio, page, nr_pages, level);
495 /* device private folios cannot get pinned via GUP. */
496 if (unlikely(folio_is_device_private(folio))) {
497 ClearPageAnonExclusive(page);
502 * We have to make sure that when we clear PageAnonExclusive, that
503 * the page is not pinned and that concurrent GUP-fast won't succeed in
504 * concurrently pinning the page.
506 * Conceptually, PageAnonExclusive clearing consists of:
508 * (A2) Check if the page is pinned; back off if so.
509 * (A3) Clear PageAnonExclusive
510 * (A4) Restore PTE (optional, but certainly not writable)
512 * When clearing PageAnonExclusive, we cannot possibly map the page
513 * writable again, because anon pages that may be shared must never
514 * be writable. So in any case, if the PTE was writable it cannot
515 * be writable anymore afterwards and there would be a PTE change. Only
516 * if the PTE wasn't writable, there might not be a PTE change.
518 * Conceptually, GUP-fast pinning of an anon page consists of:
520 * (B2) FOLL_WRITE: check if the PTE is not writable; back off if so.
521 * (B3) Pin the mapped page
522 * (B4) Check if the PTE changed by re-reading it; back off if so.
523 * (B5) If the original PTE is not writable, check if
524 * PageAnonExclusive is not set; back off if so.
526 * If the PTE was writable, we only have to make sure that GUP-fast
527 * observes a PTE change and properly backs off.
529 * If the PTE was not writable, we have to make sure that GUP-fast either
530 * detects a (temporary) PTE change or that PageAnonExclusive is cleared
531 * and properly backs off.
533 * Consequently, when clearing PageAnonExclusive(), we have to make
534 * sure that (A1), (A2)/(A3) and (A4) happen in the right memory
535 * order. In GUP-fast pinning code, we have to make sure that (B3),(B4)
536 * and (B5) happen in the right memory order.
538 * We assume that there might not be a memory barrier after
539 * clearing/invalidating the PTE (A1) and before restoring the PTE (A4),
540 * so we use explicit ones here.
543 /* Paired with the memory barrier in try_grab_folio(). */
544 if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
547 if (unlikely(folio_maybe_dma_pinned(folio)))
549 ClearPageAnonExclusive(page);
552 * This is conceptually a smp_wmb() paired with the smp_rmb() in
553 * gup_must_unshare().
555 if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
556 smp_mb__after_atomic();
561 * folio_try_share_anon_rmap_pte - try marking an exclusive anonymous page
562 * mapped by a PTE possibly shared to prepare
563 * for KSM or temporary unmapping
564 * @folio: The folio to share a mapping of
565 * @page: The mapped exclusive page
567 * The caller needs to hold the page table lock and has to have the page table
568 * entries cleared/invalidated.
570 * This is similar to folio_try_dup_anon_rmap_pte(), however, not used during
571 * fork() to duplicate mappings, but instead to prepare for KSM or temporarily
572 * unmapping parts of a folio (swap, migration) via folio_remove_rmap_pte().
574 * Marking the mapped page shared can only fail if the folio maybe pinned;
575 * device private folios cannot get pinned and consequently this function cannot
578 * Returns 0 if marking the mapped page possibly shared succeeded. Returns
581 static inline int folio_try_share_anon_rmap_pte(struct folio *folio,
584 return __folio_try_share_anon_rmap(folio, page, 1, RMAP_LEVEL_PTE);
588 * folio_try_share_anon_rmap_pmd - try marking an exclusive anonymous page
589 * range mapped by a PMD possibly shared to
590 * prepare for temporary unmapping
591 * @folio: The folio to share the mapping of
592 * @page: The first page to share the mapping of
594 * The page range of the folio is defined by [page, page + HPAGE_PMD_NR)
596 * The caller needs to hold the page table lock and has to have the page table
597 * entries cleared/invalidated.
599 * This is similar to folio_try_dup_anon_rmap_pmd(), however, not used during
600 * fork() to duplicate a mapping, but instead to prepare for temporarily
601 * unmapping parts of a folio (swap, migration) via folio_remove_rmap_pmd().
603 * Marking the mapped pages shared can only fail if the folio maybe pinned;
604 * device private folios cannot get pinned and consequently this function cannot
607 * Returns 0 if marking the mapped pages possibly shared succeeded. Returns
610 static inline int folio_try_share_anon_rmap_pmd(struct folio *folio,
613 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
614 return __folio_try_share_anon_rmap(folio, page, HPAGE_PMD_NR,
623 * Called from mm/vmscan.c to handle paging out
625 int folio_referenced(struct folio *, int is_locked,
626 struct mem_cgroup *memcg, unsigned long *vm_flags);
628 void try_to_migrate(struct folio *folio, enum ttu_flags flags);
629 void try_to_unmap(struct folio *, enum ttu_flags flags);
631 int make_device_exclusive_range(struct mm_struct *mm, unsigned long start,
632 unsigned long end, struct page **pages,
635 /* Avoid racy checks */
636 #define PVMW_SYNC (1 << 0)
637 /* Look for migration entries rather than present PTEs */
638 #define PVMW_MIGRATION (1 << 1)
640 struct page_vma_mapped_walk {
642 unsigned long nr_pages;
644 struct vm_area_struct *vma;
645 unsigned long address;
652 #define DEFINE_PAGE_VMA_WALK(name, _page, _vma, _address, _flags) \
653 struct page_vma_mapped_walk name = { \
654 .pfn = page_to_pfn(_page), \
655 .nr_pages = compound_nr(_page), \
656 .pgoff = page_to_pgoff(_page), \
658 .address = _address, \
662 #define DEFINE_FOLIO_VMA_WALK(name, _folio, _vma, _address, _flags) \
663 struct page_vma_mapped_walk name = { \
664 .pfn = folio_pfn(_folio), \
665 .nr_pages = folio_nr_pages(_folio), \
666 .pgoff = folio_pgoff(_folio), \
668 .address = _address, \
672 static inline void page_vma_mapped_walk_done(struct page_vma_mapped_walk *pvmw)
674 /* HugeTLB pte is set to the relevant page table entry without pte_mapped. */
675 if (pvmw->pte && !is_vm_hugetlb_page(pvmw->vma))
676 pte_unmap(pvmw->pte);
678 spin_unlock(pvmw->ptl);
681 bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw);
684 * Used by swapoff to help locate where page is expected in vma.
686 unsigned long page_address_in_vma(struct page *, struct vm_area_struct *);
689 * Cleans the PTEs of shared mappings.
690 * (and since clean PTEs should also be readonly, write protects them too)
692 * returns the number of cleaned PTEs.
694 int folio_mkclean(struct folio *);
696 int pfn_mkclean_range(unsigned long pfn, unsigned long nr_pages, pgoff_t pgoff,
697 struct vm_area_struct *vma);
699 void remove_migration_ptes(struct folio *src, struct folio *dst, bool locked);
701 int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
704 * rmap_walk_control: To control rmap traversing for specific needs
706 * arg: passed to rmap_one() and invalid_vma()
707 * try_lock: bail out if the rmap lock is contended
708 * contended: indicate the rmap traversal bailed out due to lock contention
709 * rmap_one: executed on each vma where page is mapped
710 * done: for checking traversing termination condition
711 * anon_lock: for getting anon_lock by optimized way rather than default
712 * invalid_vma: for skipping uninterested vma
714 struct rmap_walk_control {
719 * Return false if page table scanning in rmap_walk should be stopped.
720 * Otherwise, return true.
722 bool (*rmap_one)(struct folio *folio, struct vm_area_struct *vma,
723 unsigned long addr, void *arg);
724 int (*done)(struct folio *folio);
725 struct anon_vma *(*anon_lock)(struct folio *folio,
726 struct rmap_walk_control *rwc);
727 bool (*invalid_vma)(struct vm_area_struct *vma, void *arg);
730 void rmap_walk(struct folio *folio, struct rmap_walk_control *rwc);
731 void rmap_walk_locked(struct folio *folio, struct rmap_walk_control *rwc);
732 struct anon_vma *folio_lock_anon_vma_read(struct folio *folio,
733 struct rmap_walk_control *rwc);
735 #else /* !CONFIG_MMU */
737 #define anon_vma_init() do {} while (0)
738 #define anon_vma_prepare(vma) (0)
740 static inline int folio_referenced(struct folio *folio, int is_locked,
741 struct mem_cgroup *memcg,
742 unsigned long *vm_flags)
748 static inline void try_to_unmap(struct folio *folio, enum ttu_flags flags)
752 static inline int folio_mkclean(struct folio *folio)
756 #endif /* CONFIG_MMU */
758 static inline int page_mkclean(struct page *page)
760 return folio_mkclean(page_folio(page));
762 #endif /* _LINUX_RMAP_H */