Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0-or-later */
2 : /* internal.h: mm/ internal definitions
3 : *
4 : * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
5 : * Written by David Howells (dhowells@redhat.com)
6 : */
7 : #ifndef __MM_INTERNAL_H
8 : #define __MM_INTERNAL_H
9 :
10 : #include <linux/fs.h>
11 : #include <linux/mm.h>
12 : #include <linux/pagemap.h>
13 : #include <linux/rmap.h>
14 : #include <linux/tracepoint-defs.h>
15 :
16 : struct folio_batch;
17 :
18 : /*
19 : * The set of flags that only affect watermark checking and reclaim
20 : * behaviour. This is used by the MM to obey the caller constraints
21 : * about IO, FS and watermark checking while ignoring placement
22 : * hints such as HIGHMEM usage.
23 : */
24 : #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
25 : __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\
26 : __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
27 : __GFP_NOLOCKDEP)
28 :
29 : /* The GFP flags allowed during early boot */
30 : #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
31 :
32 : /* Control allocation cpuset and node placement constraints */
33 : #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
34 :
35 : /* Do not use these with a slab allocator */
36 : #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
37 :
38 : /*
39 : * Different from WARN_ON_ONCE(), no warning will be issued
40 : * when we specify __GFP_NOWARN.
41 : */
42 : #define WARN_ON_ONCE_GFP(cond, gfp) ({ \
43 : static bool __section(".data.once") __warned; \
44 : int __ret_warn_once = !!(cond); \
45 : \
46 : if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \
47 : __warned = true; \
48 : WARN_ON(1); \
49 : } \
50 : unlikely(__ret_warn_once); \
51 : })
52 :
53 : void page_writeback_init(void);
54 :
55 : /*
56 : * If a 16GB hugetlb folio were mapped by PTEs of all of its 4kB pages,
57 : * its nr_pages_mapped would be 0x400000: choose the COMPOUND_MAPPED bit
58 : * above that range, instead of 2*(PMD_SIZE/PAGE_SIZE). Hugetlb currently
59 : * leaves nr_pages_mapped at 0, but avoid surprise if it participates later.
60 : */
61 : #define COMPOUND_MAPPED 0x800000
62 : #define FOLIO_PAGES_MAPPED (COMPOUND_MAPPED - 1)
63 :
64 : /*
65 : * How many individual pages have an elevated _mapcount. Excludes
66 : * the folio's entire_mapcount.
67 : */
68 : static inline int folio_nr_pages_mapped(struct folio *folio)
69 : {
70 : return atomic_read(&folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED;
71 : }
72 :
73 : static inline void *folio_raw_mapping(struct folio *folio)
74 : {
75 : unsigned long mapping = (unsigned long)folio->mapping;
76 :
77 : return (void *)(mapping & ~PAGE_MAPPING_FLAGS);
78 : }
79 :
80 : void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio,
81 : int nr_throttled);
82 806475055 : static inline void acct_reclaim_writeback(struct folio *folio)
83 : {
84 806475055 : pg_data_t *pgdat = folio_pgdat(folio);
85 806475055 : int nr_throttled = atomic_read(&pgdat->nr_writeback_throttled);
86 :
87 806475055 : if (nr_throttled)
88 0 : __acct_reclaim_writeback(pgdat, folio, nr_throttled);
89 806475055 : }
90 :
91 : static inline void wake_throttle_isolated(pg_data_t *pgdat)
92 : {
93 : wait_queue_head_t *wqh;
94 :
95 : wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED];
96 : if (waitqueue_active(wqh))
97 : wake_up(wqh);
98 : }
99 :
100 : vm_fault_t do_swap_page(struct vm_fault *vmf);
101 : void folio_rotate_reclaimable(struct folio *folio);
102 : bool __folio_end_writeback(struct folio *folio);
103 : void deactivate_file_folio(struct folio *folio);
104 : void folio_activate(struct folio *folio);
105 :
106 : void free_pgtables(struct mmu_gather *tlb, struct maple_tree *mt,
107 : struct vm_area_struct *start_vma, unsigned long floor,
108 : unsigned long ceiling, bool mm_wr_locked);
109 : void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);
110 :
111 : struct zap_details;
112 : void unmap_page_range(struct mmu_gather *tlb,
113 : struct vm_area_struct *vma,
114 : unsigned long addr, unsigned long end,
115 : struct zap_details *details);
116 :
117 : void page_cache_ra_order(struct readahead_control *, struct file_ra_state *,
118 : unsigned int order);
119 : void force_page_cache_ra(struct readahead_control *, unsigned long nr);
120 : static inline void force_page_cache_readahead(struct address_space *mapping,
121 : struct file *file, pgoff_t index, unsigned long nr_to_read)
122 : {
123 : DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index);
124 : force_page_cache_ra(&ractl, nr_to_read);
125 : }
126 :
127 : unsigned find_lock_entries(struct address_space *mapping, pgoff_t *start,
128 : pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
129 : unsigned find_get_entries(struct address_space *mapping, pgoff_t *start,
130 : pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
131 : void filemap_free_folio(struct address_space *mapping, struct folio *folio);
132 : int truncate_inode_folio(struct address_space *mapping, struct folio *folio);
133 : bool truncate_inode_partial_folio(struct folio *folio, loff_t start,
134 : loff_t end);
135 : long invalidate_inode_page(struct page *page);
136 : unsigned long mapping_try_invalidate(struct address_space *mapping,
137 : pgoff_t start, pgoff_t end, unsigned long *nr_failed);
138 :
139 : /**
140 : * folio_evictable - Test whether a folio is evictable.
141 : * @folio: The folio to test.
142 : *
143 : * Test whether @folio is evictable -- i.e., should be placed on
144 : * active/inactive lists vs unevictable list.
145 : *
146 : * Reasons folio might not be evictable:
147 : * 1. folio's mapping marked unevictable
148 : * 2. One of the pages in the folio is part of an mlocked VMA
149 : */
150 : static inline bool folio_evictable(struct folio *folio)
151 : {
152 : bool ret;
153 :
154 : /* Prevent address_space of inode and swap cache from being freed */
155 : rcu_read_lock();
156 : ret = !mapping_unevictable(folio_mapping(folio)) &&
157 : !folio_test_mlocked(folio);
158 : rcu_read_unlock();
159 : return ret;
160 : }
161 :
162 : /*
163 : * Turn a non-refcounted page (->_refcount == 0) into refcounted with
164 : * a count of one.
165 : */
166 : static inline void set_page_refcounted(struct page *page)
167 : {
168 : VM_BUG_ON_PAGE(PageTail(page), page);
169 : VM_BUG_ON_PAGE(page_ref_count(page), page);
170 : set_page_count(page, 1);
171 : }
172 :
173 : extern unsigned long highest_memmap_pfn;
174 :
175 : /*
176 : * Maximum number of reclaim retries without progress before the OOM
177 : * killer is consider the only way forward.
178 : */
179 : #define MAX_RECLAIM_RETRIES 16
180 :
181 : /*
182 : * in mm/vmscan.c:
183 : */
184 : bool isolate_lru_page(struct page *page);
185 : bool folio_isolate_lru(struct folio *folio);
186 : void putback_lru_page(struct page *page);
187 : void folio_putback_lru(struct folio *folio);
188 : extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason);
189 :
190 : /*
191 : * in mm/rmap.c:
192 : */
193 : pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
194 :
195 : /*
196 : * in mm/page_alloc.c
197 : */
198 : #define K(x) ((x) << (PAGE_SHIFT-10))
199 :
200 : extern char * const zone_names[MAX_NR_ZONES];
201 :
202 : /* perform sanity checks on struct pages being allocated or freed */
203 : DECLARE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled);
204 :
205 : extern int min_free_kbytes;
206 :
207 : void setup_per_zone_wmarks(void);
208 : void calculate_min_free_kbytes(void);
209 : int __meminit init_per_zone_wmark_min(void);
210 : void page_alloc_sysctl_init(void);
211 :
212 : /*
213 : * Structure for holding the mostly immutable allocation parameters passed
214 : * between functions involved in allocations, including the alloc_pages*
215 : * family of functions.
216 : *
217 : * nodemask, migratetype and highest_zoneidx are initialized only once in
218 : * __alloc_pages() and then never change.
219 : *
220 : * zonelist, preferred_zone and highest_zoneidx are set first in
221 : * __alloc_pages() for the fast path, and might be later changed
222 : * in __alloc_pages_slowpath(). All other functions pass the whole structure
223 : * by a const pointer.
224 : */
225 : struct alloc_context {
226 : struct zonelist *zonelist;
227 : nodemask_t *nodemask;
228 : struct zoneref *preferred_zoneref;
229 : int migratetype;
230 :
231 : /*
232 : * highest_zoneidx represents highest usable zone index of
233 : * the allocation request. Due to the nature of the zone,
234 : * memory on lower zone than the highest_zoneidx will be
235 : * protected by lowmem_reserve[highest_zoneidx].
236 : *
237 : * highest_zoneidx is also used by reclaim/compaction to limit
238 : * the target zone since higher zone than this index cannot be
239 : * usable for this allocation request.
240 : */
241 : enum zone_type highest_zoneidx;
242 : bool spread_dirty_pages;
243 : };
244 :
245 : /*
246 : * This function returns the order of a free page in the buddy system. In
247 : * general, page_zone(page)->lock must be held by the caller to prevent the
248 : * page from being allocated in parallel and returning garbage as the order.
249 : * If a caller does not hold page_zone(page)->lock, it must guarantee that the
250 : * page cannot be allocated or merged in parallel. Alternatively, it must
251 : * handle invalid values gracefully, and use buddy_order_unsafe() below.
252 : */
253 : static inline unsigned int buddy_order(struct page *page)
254 : {
255 : /* PageBuddy() must be checked by the caller */
256 : return page_private(page);
257 : }
258 :
259 : /*
260 : * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
261 : * PageBuddy() should be checked first by the caller to minimize race window,
262 : * and invalid values must be handled gracefully.
263 : *
264 : * READ_ONCE is used so that if the caller assigns the result into a local
265 : * variable and e.g. tests it for valid range before using, the compiler cannot
266 : * decide to remove the variable and inline the page_private(page) multiple
267 : * times, potentially observing different values in the tests and the actual
268 : * use of the result.
269 : */
270 : #define buddy_order_unsafe(page) READ_ONCE(page_private(page))
271 :
272 : /*
273 : * This function checks whether a page is free && is the buddy
274 : * we can coalesce a page and its buddy if
275 : * (a) the buddy is not in a hole (check before calling!) &&
276 : * (b) the buddy is in the buddy system &&
277 : * (c) a page and its buddy have the same order &&
278 : * (d) a page and its buddy are in the same zone.
279 : *
280 : * For recording whether a page is in the buddy system, we set PageBuddy.
281 : * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
282 : *
283 : * For recording page's order, we use page_private(page).
284 : */
285 : static inline bool page_is_buddy(struct page *page, struct page *buddy,
286 : unsigned int order)
287 : {
288 : if (!page_is_guard(buddy) && !PageBuddy(buddy))
289 : return false;
290 :
291 : if (buddy_order(buddy) != order)
292 : return false;
293 :
294 : /*
295 : * zone check is done late to avoid uselessly calculating
296 : * zone/node ids for pages that could never merge.
297 : */
298 : if (page_zone_id(page) != page_zone_id(buddy))
299 : return false;
300 :
301 : VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
302 :
303 : return true;
304 : }
305 :
306 : /*
307 : * Locate the struct page for both the matching buddy in our
308 : * pair (buddy1) and the combined O(n+1) page they form (page).
309 : *
310 : * 1) Any buddy B1 will have an order O twin B2 which satisfies
311 : * the following equation:
312 : * B2 = B1 ^ (1 << O)
313 : * For example, if the starting buddy (buddy2) is #8 its order
314 : * 1 buddy is #10:
315 : * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
316 : *
317 : * 2) Any buddy B will have an order O+1 parent P which
318 : * satisfies the following equation:
319 : * P = B & ~(1 << O)
320 : *
321 : * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
322 : */
323 : static inline unsigned long
324 : __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
325 : {
326 : return page_pfn ^ (1 << order);
327 : }
328 :
329 : /*
330 : * Find the buddy of @page and validate it.
331 : * @page: The input page
332 : * @pfn: The pfn of the page, it saves a call to page_to_pfn() when the
333 : * function is used in the performance-critical __free_one_page().
334 : * @order: The order of the page
335 : * @buddy_pfn: The output pointer to the buddy pfn, it also saves a call to
336 : * page_to_pfn().
337 : *
338 : * The found buddy can be a non PageBuddy, out of @page's zone, or its order is
339 : * not the same as @page. The validation is necessary before use it.
340 : *
341 : * Return: the found buddy page or NULL if not found.
342 : */
343 : static inline struct page *find_buddy_page_pfn(struct page *page,
344 : unsigned long pfn, unsigned int order, unsigned long *buddy_pfn)
345 : {
346 : unsigned long __buddy_pfn = __find_buddy_pfn(pfn, order);
347 : struct page *buddy;
348 :
349 : buddy = page + (__buddy_pfn - pfn);
350 : if (buddy_pfn)
351 : *buddy_pfn = __buddy_pfn;
352 :
353 : if (page_is_buddy(page, buddy, order))
354 : return buddy;
355 : return NULL;
356 : }
357 :
358 : extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
359 : unsigned long end_pfn, struct zone *zone);
360 :
361 : static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
362 : unsigned long end_pfn, struct zone *zone)
363 : {
364 : if (zone->contiguous)
365 : return pfn_to_page(start_pfn);
366 :
367 : return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
368 : }
369 :
370 : void set_zone_contiguous(struct zone *zone);
371 :
372 : static inline void clear_zone_contiguous(struct zone *zone)
373 : {
374 : zone->contiguous = false;
375 : }
376 :
377 : extern int __isolate_free_page(struct page *page, unsigned int order);
378 : extern void __putback_isolated_page(struct page *page, unsigned int order,
379 : int mt);
380 : extern void memblock_free_pages(struct page *page, unsigned long pfn,
381 : unsigned int order);
382 : extern void __free_pages_core(struct page *page, unsigned int order);
383 :
384 : /*
385 : * This will have no effect, other than possibly generating a warning, if the
386 : * caller passes in a non-large folio.
387 : */
388 : static inline void folio_set_order(struct folio *folio, unsigned int order)
389 : {
390 : if (WARN_ON_ONCE(!order || !folio_test_large(folio)))
391 : return;
392 :
393 : folio->_folio_order = order;
394 : #ifdef CONFIG_64BIT
395 : folio->_folio_nr_pages = 1U << order;
396 : #endif
397 : }
398 :
399 : static inline void prep_compound_head(struct page *page, unsigned int order)
400 : {
401 : struct folio *folio = (struct folio *)page;
402 :
403 : folio_set_compound_dtor(folio, COMPOUND_PAGE_DTOR);
404 : folio_set_order(folio, order);
405 : atomic_set(&folio->_entire_mapcount, -1);
406 : atomic_set(&folio->_nr_pages_mapped, 0);
407 : atomic_set(&folio->_pincount, 0);
408 : }
409 :
410 : static inline void prep_compound_tail(struct page *head, int tail_idx)
411 : {
412 : struct page *p = head + tail_idx;
413 :
414 : p->mapping = TAIL_MAPPING;
415 : set_compound_head(p, head);
416 : set_page_private(p, 0);
417 : }
418 :
419 : extern void prep_compound_page(struct page *page, unsigned int order);
420 :
421 : extern void post_alloc_hook(struct page *page, unsigned int order,
422 : gfp_t gfp_flags);
423 : extern int user_min_free_kbytes;
424 :
425 : extern void free_unref_page(struct page *page, unsigned int order);
426 : extern void free_unref_page_list(struct list_head *list);
427 :
428 : extern void zone_pcp_reset(struct zone *zone);
429 : extern void zone_pcp_disable(struct zone *zone);
430 : extern void zone_pcp_enable(struct zone *zone);
431 : extern void zone_pcp_init(struct zone *zone);
432 :
433 : extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
434 : phys_addr_t min_addr,
435 : int nid, bool exact_nid);
436 :
437 : void memmap_init_range(unsigned long, int, unsigned long, unsigned long,
438 : unsigned long, enum meminit_context, struct vmem_altmap *, int);
439 :
440 :
441 : int split_free_page(struct page *free_page,
442 : unsigned int order, unsigned long split_pfn_offset);
443 :
444 : #if defined CONFIG_COMPACTION || defined CONFIG_CMA
445 :
446 : /*
447 : * in mm/compaction.c
448 : */
449 : /*
450 : * compact_control is used to track pages being migrated and the free pages
451 : * they are being migrated to during memory compaction. The free_pfn starts
452 : * at the end of a zone and migrate_pfn begins at the start. Movable pages
453 : * are moved to the end of a zone during a compaction run and the run
454 : * completes when free_pfn <= migrate_pfn
455 : */
456 : struct compact_control {
457 : struct list_head freepages; /* List of free pages to migrate to */
458 : struct list_head migratepages; /* List of pages being migrated */
459 : unsigned int nr_freepages; /* Number of isolated free pages */
460 : unsigned int nr_migratepages; /* Number of pages to migrate */
461 : unsigned long free_pfn; /* isolate_freepages search base */
462 : /*
463 : * Acts as an in/out parameter to page isolation for migration.
464 : * isolate_migratepages uses it as a search base.
465 : * isolate_migratepages_block will update the value to the next pfn
466 : * after the last isolated one.
467 : */
468 : unsigned long migrate_pfn;
469 : unsigned long fast_start_pfn; /* a pfn to start linear scan from */
470 : struct zone *zone;
471 : unsigned long total_migrate_scanned;
472 : unsigned long total_free_scanned;
473 : unsigned short fast_search_fail;/* failures to use free list searches */
474 : short search_order; /* order to start a fast search at */
475 : const gfp_t gfp_mask; /* gfp mask of a direct compactor */
476 : int order; /* order a direct compactor needs */
477 : int migratetype; /* migratetype of direct compactor */
478 : const unsigned int alloc_flags; /* alloc flags of a direct compactor */
479 : const int highest_zoneidx; /* zone index of a direct compactor */
480 : enum migrate_mode mode; /* Async or sync migration mode */
481 : bool ignore_skip_hint; /* Scan blocks even if marked skip */
482 : bool no_set_skip_hint; /* Don't mark blocks for skipping */
483 : bool ignore_block_suitable; /* Scan blocks considered unsuitable */
484 : bool direct_compaction; /* False from kcompactd or /proc/... */
485 : bool proactive_compaction; /* kcompactd proactive compaction */
486 : bool whole_zone; /* Whole zone should/has been scanned */
487 : bool contended; /* Signal lock contention */
488 : bool finish_pageblock; /* Scan the remainder of a pageblock. Used
489 : * when there are potentially transient
490 : * isolation or migration failures to
491 : * ensure forward progress.
492 : */
493 : bool alloc_contig; /* alloc_contig_range allocation */
494 : };
495 :
496 : /*
497 : * Used in direct compaction when a page should be taken from the freelists
498 : * immediately when one is created during the free path.
499 : */
500 : struct capture_control {
501 : struct compact_control *cc;
502 : struct page *page;
503 : };
504 :
505 : unsigned long
506 : isolate_freepages_range(struct compact_control *cc,
507 : unsigned long start_pfn, unsigned long end_pfn);
508 : int
509 : isolate_migratepages_range(struct compact_control *cc,
510 : unsigned long low_pfn, unsigned long end_pfn);
511 :
512 : int __alloc_contig_migrate_range(struct compact_control *cc,
513 : unsigned long start, unsigned long end);
514 :
515 : /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
516 : void init_cma_reserved_pageblock(struct page *page);
517 :
518 : #endif /* CONFIG_COMPACTION || CONFIG_CMA */
519 :
520 : int find_suitable_fallback(struct free_area *area, unsigned int order,
521 : int migratetype, bool only_stealable, bool *can_steal);
522 :
523 : static inline bool free_area_empty(struct free_area *area, int migratetype)
524 : {
525 : return list_empty(&area->free_list[migratetype]);
526 : }
527 :
528 : /*
529 : * These three helpers classifies VMAs for virtual memory accounting.
530 : */
531 :
532 : /*
533 : * Executable code area - executable, not writable, not stack
534 : */
535 : static inline bool is_exec_mapping(vm_flags_t flags)
536 : {
537 : return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
538 : }
539 :
540 : /*
541 : * Stack area - automatically grows in one direction
542 : *
543 : * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
544 : * do_mmap() forbids all other combinations.
545 : */
546 : static inline bool is_stack_mapping(vm_flags_t flags)
547 : {
548 : return (flags & VM_STACK) == VM_STACK;
549 : }
550 :
551 : /*
552 : * Data area - private, writable, not stack
553 : */
554 : static inline bool is_data_mapping(vm_flags_t flags)
555 : {
556 : return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
557 : }
558 :
559 : /* mm/util.c */
560 : struct anon_vma *folio_anon_vma(struct folio *folio);
561 :
562 : #ifdef CONFIG_MMU
563 : void unmap_mapping_folio(struct folio *folio);
564 : extern long populate_vma_page_range(struct vm_area_struct *vma,
565 : unsigned long start, unsigned long end, int *locked);
566 : extern long faultin_vma_page_range(struct vm_area_struct *vma,
567 : unsigned long start, unsigned long end,
568 : bool write, int *locked);
569 : extern bool mlock_future_ok(struct mm_struct *mm, unsigned long flags,
570 : unsigned long bytes);
571 : /*
572 : * mlock_vma_folio() and munlock_vma_folio():
573 : * should be called with vma's mmap_lock held for read or write,
574 : * under page table lock for the pte/pmd being added or removed.
575 : *
576 : * mlock is usually called at the end of page_add_*_rmap(), munlock at
577 : * the end of page_remove_rmap(); but new anon folios are managed by
578 : * folio_add_lru_vma() calling mlock_new_folio().
579 : *
580 : * @compound is used to include pmd mappings of THPs, but filter out
581 : * pte mappings of THPs, which cannot be consistently counted: a pte
582 : * mapping of the THP head cannot be distinguished by the page alone.
583 : */
584 : void mlock_folio(struct folio *folio);
585 : static inline void mlock_vma_folio(struct folio *folio,
586 : struct vm_area_struct *vma, bool compound)
587 : {
588 : /*
589 : * The VM_SPECIAL check here serves two purposes.
590 : * 1) VM_IO check prevents migration from double-counting during mlock.
591 : * 2) Although mmap_region() and mlock_fixup() take care that VM_LOCKED
592 : * is never left set on a VM_SPECIAL vma, there is an interval while
593 : * file->f_op->mmap() is using vm_insert_page(s), when VM_LOCKED may
594 : * still be set while VM_SPECIAL bits are added: so ignore it then.
595 : */
596 : if (unlikely((vma->vm_flags & (VM_LOCKED|VM_SPECIAL)) == VM_LOCKED) &&
597 : (compound || !folio_test_large(folio)))
598 : mlock_folio(folio);
599 : }
600 :
601 : void munlock_folio(struct folio *folio);
602 : static inline void munlock_vma_folio(struct folio *folio,
603 : struct vm_area_struct *vma, bool compound)
604 : {
605 : if (unlikely(vma->vm_flags & VM_LOCKED) &&
606 : (compound || !folio_test_large(folio)))
607 : munlock_folio(folio);
608 : }
609 :
610 : void mlock_new_folio(struct folio *folio);
611 : bool need_mlock_drain(int cpu);
612 : void mlock_drain_local(void);
613 : void mlock_drain_remote(int cpu);
614 :
615 : extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
616 :
617 : /*
618 : * Return the start of user virtual address at the specific offset within
619 : * a vma.
620 : */
621 : static inline unsigned long
622 : vma_pgoff_address(pgoff_t pgoff, unsigned long nr_pages,
623 : struct vm_area_struct *vma)
624 : {
625 : unsigned long address;
626 :
627 : if (pgoff >= vma->vm_pgoff) {
628 : address = vma->vm_start +
629 : ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
630 : /* Check for address beyond vma (or wrapped through 0?) */
631 : if (address < vma->vm_start || address >= vma->vm_end)
632 : address = -EFAULT;
633 : } else if (pgoff + nr_pages - 1 >= vma->vm_pgoff) {
634 : /* Test above avoids possibility of wrap to 0 on 32-bit */
635 : address = vma->vm_start;
636 : } else {
637 : address = -EFAULT;
638 : }
639 : return address;
640 : }
641 :
642 : /*
643 : * Return the start of user virtual address of a page within a vma.
644 : * Returns -EFAULT if all of the page is outside the range of vma.
645 : * If page is a compound head, the entire compound page is considered.
646 : */
647 : static inline unsigned long
648 : vma_address(struct page *page, struct vm_area_struct *vma)
649 : {
650 : VM_BUG_ON_PAGE(PageKsm(page), page); /* KSM page->index unusable */
651 : return vma_pgoff_address(page_to_pgoff(page), compound_nr(page), vma);
652 : }
653 :
654 : /*
655 : * Then at what user virtual address will none of the range be found in vma?
656 : * Assumes that vma_address() already returned a good starting address.
657 : */
658 : static inline unsigned long vma_address_end(struct page_vma_mapped_walk *pvmw)
659 : {
660 : struct vm_area_struct *vma = pvmw->vma;
661 : pgoff_t pgoff;
662 : unsigned long address;
663 :
664 : /* Common case, plus ->pgoff is invalid for KSM */
665 : if (pvmw->nr_pages == 1)
666 : return pvmw->address + PAGE_SIZE;
667 :
668 : pgoff = pvmw->pgoff + pvmw->nr_pages;
669 : address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
670 : /* Check for address beyond vma (or wrapped through 0?) */
671 : if (address < vma->vm_start || address > vma->vm_end)
672 : address = vma->vm_end;
673 : return address;
674 : }
675 :
676 8045238 : static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
677 : struct file *fpin)
678 : {
679 8045238 : int flags = vmf->flags;
680 :
681 8045238 : if (fpin)
682 : return fpin;
683 :
684 : /*
685 : * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
686 : * anything, so we only pin the file and drop the mmap_lock if only
687 : * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
688 : */
689 7359083 : if (fault_flag_allow_retry_first(flags) &&
690 7221780 : !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
691 7221780 : fpin = get_file(vmf->vma->vm_file);
692 7222334 : mmap_read_unlock(vmf->vma->vm_mm);
693 : }
694 : return fpin;
695 : }
696 : #else /* !CONFIG_MMU */
697 : static inline void unmap_mapping_folio(struct folio *folio) { }
698 : static inline void mlock_new_folio(struct folio *folio) { }
699 : static inline bool need_mlock_drain(int cpu) { return false; }
700 : static inline void mlock_drain_local(void) { }
701 : static inline void mlock_drain_remote(int cpu) { }
702 : static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
703 : {
704 : }
705 : #endif /* !CONFIG_MMU */
706 :
707 : /* Memory initialisation debug and verification */
708 : #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
709 : DECLARE_STATIC_KEY_TRUE(deferred_pages);
710 :
711 : bool __init deferred_grow_zone(struct zone *zone, unsigned int order);
712 : #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
713 :
714 : enum mminit_level {
715 : MMINIT_WARNING,
716 : MMINIT_VERIFY,
717 : MMINIT_TRACE
718 : };
719 :
720 : #ifdef CONFIG_DEBUG_MEMORY_INIT
721 :
722 : extern int mminit_loglevel;
723 :
724 : #define mminit_dprintk(level, prefix, fmt, arg...) \
725 : do { \
726 : if (level < mminit_loglevel) { \
727 : if (level <= MMINIT_WARNING) \
728 : pr_warn("mminit::" prefix " " fmt, ##arg); \
729 : else \
730 : printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
731 : } \
732 : } while (0)
733 :
734 : extern void mminit_verify_pageflags_layout(void);
735 : extern void mminit_verify_zonelist(void);
736 : #else
737 :
738 : static inline void mminit_dprintk(enum mminit_level level,
739 : const char *prefix, const char *fmt, ...)
740 : {
741 : }
742 :
743 : static inline void mminit_verify_pageflags_layout(void)
744 : {
745 : }
746 :
747 : static inline void mminit_verify_zonelist(void)
748 : {
749 : }
750 : #endif /* CONFIG_DEBUG_MEMORY_INIT */
751 :
752 : #define NODE_RECLAIM_NOSCAN -2
753 : #define NODE_RECLAIM_FULL -1
754 : #define NODE_RECLAIM_SOME 0
755 : #define NODE_RECLAIM_SUCCESS 1
756 :
757 : #ifdef CONFIG_NUMA
758 : extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
759 : extern int find_next_best_node(int node, nodemask_t *used_node_mask);
760 : #else
761 : static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
762 : unsigned int order)
763 : {
764 : return NODE_RECLAIM_NOSCAN;
765 : }
766 : static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
767 : {
768 : return NUMA_NO_NODE;
769 : }
770 : #endif
771 :
772 : /*
773 : * mm/memory-failure.c
774 : */
775 : extern int hwpoison_filter(struct page *p);
776 :
777 : extern u32 hwpoison_filter_dev_major;
778 : extern u32 hwpoison_filter_dev_minor;
779 : extern u64 hwpoison_filter_flags_mask;
780 : extern u64 hwpoison_filter_flags_value;
781 : extern u64 hwpoison_filter_memcg;
782 : extern u32 hwpoison_filter_enable;
783 :
784 : extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
785 : unsigned long, unsigned long,
786 : unsigned long, unsigned long);
787 :
788 : extern void set_pageblock_order(void);
789 : unsigned long reclaim_pages(struct list_head *folio_list);
790 : unsigned int reclaim_clean_pages_from_list(struct zone *zone,
791 : struct list_head *folio_list);
792 : /* The ALLOC_WMARK bits are used as an index to zone->watermark */
793 : #define ALLOC_WMARK_MIN WMARK_MIN
794 : #define ALLOC_WMARK_LOW WMARK_LOW
795 : #define ALLOC_WMARK_HIGH WMARK_HIGH
796 : #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
797 :
798 : /* Mask to get the watermark bits */
799 : #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
800 :
801 : /*
802 : * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
803 : * cannot assume a reduced access to memory reserves is sufficient for
804 : * !MMU
805 : */
806 : #ifdef CONFIG_MMU
807 : #define ALLOC_OOM 0x08
808 : #else
809 : #define ALLOC_OOM ALLOC_NO_WATERMARKS
810 : #endif
811 :
812 : #define ALLOC_NON_BLOCK 0x10 /* Caller cannot block. Allow access
813 : * to 25% of the min watermark or
814 : * 62.5% if __GFP_HIGH is set.
815 : */
816 : #define ALLOC_MIN_RESERVE 0x20 /* __GFP_HIGH set. Allow access to 50%
817 : * of the min watermark.
818 : */
819 : #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
820 : #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
821 : #ifdef CONFIG_ZONE_DMA32
822 : #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */
823 : #else
824 : #define ALLOC_NOFRAGMENT 0x0
825 : #endif
826 : #define ALLOC_HIGHATOMIC 0x200 /* Allows access to MIGRATE_HIGHATOMIC */
827 : #define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
828 :
829 : /* Flags that allow allocations below the min watermark. */
830 : #define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM)
831 :
832 : enum ttu_flags;
833 : struct tlbflush_unmap_batch;
834 :
835 :
836 : /*
837 : * only for MM internal work items which do not depend on
838 : * any allocations or locks which might depend on allocations
839 : */
840 : extern struct workqueue_struct *mm_percpu_wq;
841 :
842 : #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
843 : void try_to_unmap_flush(void);
844 : void try_to_unmap_flush_dirty(void);
845 : void flush_tlb_batched_pending(struct mm_struct *mm);
846 : #else
847 : static inline void try_to_unmap_flush(void)
848 : {
849 : }
850 : static inline void try_to_unmap_flush_dirty(void)
851 : {
852 : }
853 : static inline void flush_tlb_batched_pending(struct mm_struct *mm)
854 : {
855 : }
856 : #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
857 :
858 : extern const struct trace_print_flags pageflag_names[];
859 : extern const struct trace_print_flags pagetype_names[];
860 : extern const struct trace_print_flags vmaflag_names[];
861 : extern const struct trace_print_flags gfpflag_names[];
862 :
863 : static inline bool is_migrate_highatomic(enum migratetype migratetype)
864 : {
865 : return migratetype == MIGRATE_HIGHATOMIC;
866 : }
867 :
868 : static inline bool is_migrate_highatomic_page(struct page *page)
869 : {
870 : return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
871 : }
872 :
873 : void setup_zone_pageset(struct zone *zone);
874 :
875 : struct migration_target_control {
876 : int nid; /* preferred node id */
877 : nodemask_t *nmask;
878 : gfp_t gfp_mask;
879 : };
880 :
881 : /*
882 : * mm/filemap.c
883 : */
884 : size_t splice_folio_into_pipe(struct pipe_inode_info *pipe,
885 : struct folio *folio, loff_t fpos, size_t size);
886 :
887 : /*
888 : * mm/vmalloc.c
889 : */
890 : #ifdef CONFIG_MMU
891 : void __init vmalloc_init(void);
892 : int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end,
893 : pgprot_t prot, struct page **pages, unsigned int page_shift);
894 : #else
895 : static inline void vmalloc_init(void)
896 : {
897 : }
898 :
899 : static inline
900 : int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end,
901 : pgprot_t prot, struct page **pages, unsigned int page_shift)
902 : {
903 : return -EINVAL;
904 : }
905 : #endif
906 :
907 : int __must_check __vmap_pages_range_noflush(unsigned long addr,
908 : unsigned long end, pgprot_t prot,
909 : struct page **pages, unsigned int page_shift);
910 :
911 : void vunmap_range_noflush(unsigned long start, unsigned long end);
912 :
913 : void __vunmap_range_noflush(unsigned long start, unsigned long end);
914 :
915 : int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
916 : unsigned long addr, int page_nid, int *flags);
917 :
918 : void free_zone_device_page(struct page *page);
919 : int migrate_device_coherent_page(struct page *page);
920 :
921 : /*
922 : * mm/gup.c
923 : */
924 : struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
925 : int __must_check try_grab_page(struct page *page, unsigned int flags);
926 :
927 : enum {
928 : /* mark page accessed */
929 : FOLL_TOUCH = 1 << 16,
930 : /* a retry, previous pass started an IO */
931 : FOLL_TRIED = 1 << 17,
932 : /* we are working on non-current tsk/mm */
933 : FOLL_REMOTE = 1 << 18,
934 : /* pages must be released via unpin_user_page */
935 : FOLL_PIN = 1 << 19,
936 : /* gup_fast: prevent fall-back to slow gup */
937 : FOLL_FAST_ONLY = 1 << 20,
938 : /* allow unlocking the mmap lock */
939 : FOLL_UNLOCKABLE = 1 << 21,
940 : };
941 :
942 : /*
943 : * Indicates for which pages that are write-protected in the page table,
944 : * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that the
945 : * GUP pin will remain consistent with the pages mapped into the page tables
946 : * of the MM.
947 : *
948 : * Temporary unmapping of PageAnonExclusive() pages or clearing of
949 : * PageAnonExclusive() has to protect against concurrent GUP:
950 : * * Ordinary GUP: Using the PT lock
951 : * * GUP-fast and fork(): mm->write_protect_seq
952 : * * GUP-fast and KSM or temporary unmapping (swap, migration): see
953 : * page_try_share_anon_rmap()
954 : *
955 : * Must be called with the (sub)page that's actually referenced via the
956 : * page table entry, which might not necessarily be the head page for a
957 : * PTE-mapped THP.
958 : *
959 : * If the vma is NULL, we're coming from the GUP-fast path and might have
960 : * to fallback to the slow path just to lookup the vma.
961 : */
962 : static inline bool gup_must_unshare(struct vm_area_struct *vma,
963 : unsigned int flags, struct page *page)
964 : {
965 : /*
966 : * FOLL_WRITE is implicitly handled correctly as the page table entry
967 : * has to be writable -- and if it references (part of) an anonymous
968 : * folio, that part is required to be marked exclusive.
969 : */
970 : if ((flags & (FOLL_WRITE | FOLL_PIN)) != FOLL_PIN)
971 : return false;
972 : /*
973 : * Note: PageAnon(page) is stable until the page is actually getting
974 : * freed.
975 : */
976 : if (!PageAnon(page)) {
977 : /*
978 : * We only care about R/O long-term pining: R/O short-term
979 : * pinning does not have the semantics to observe successive
980 : * changes through the process page tables.
981 : */
982 : if (!(flags & FOLL_LONGTERM))
983 : return false;
984 :
985 : /* We really need the vma ... */
986 : if (!vma)
987 : return true;
988 :
989 : /*
990 : * ... because we only care about writable private ("COW")
991 : * mappings where we have to break COW early.
992 : */
993 : return is_cow_mapping(vma->vm_flags);
994 : }
995 :
996 : /* Paired with a memory barrier in page_try_share_anon_rmap(). */
997 : if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
998 : smp_rmb();
999 :
1000 : /*
1001 : * Note that PageKsm() pages cannot be exclusive, and consequently,
1002 : * cannot get pinned.
1003 : */
1004 : return !PageAnonExclusive(page);
1005 : }
1006 :
1007 : extern bool mirrored_kernelcore;
1008 :
1009 : static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma)
1010 : {
1011 : /*
1012 : * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty
1013 : * enablements, because when without soft-dirty being compiled in,
1014 : * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY)
1015 : * will be constantly true.
1016 : */
1017 : if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
1018 : return false;
1019 :
1020 : /*
1021 : * Soft-dirty is kind of special: its tracking is enabled when the
1022 : * vma flags not set.
1023 : */
1024 : return !(vma->vm_flags & VM_SOFTDIRTY);
1025 : }
1026 :
1027 : /*
1028 : * VMA Iterator functions shared between nommu and mmap
1029 : */
1030 : static inline int vma_iter_prealloc(struct vma_iterator *vmi)
1031 : {
1032 : return mas_preallocate(&vmi->mas, GFP_KERNEL);
1033 : }
1034 :
1035 : static inline void vma_iter_clear(struct vma_iterator *vmi,
1036 : unsigned long start, unsigned long end)
1037 : {
1038 : mas_set_range(&vmi->mas, start, end - 1);
1039 : mas_store_prealloc(&vmi->mas, NULL);
1040 : }
1041 :
1042 : static inline struct vm_area_struct *vma_iter_load(struct vma_iterator *vmi)
1043 : {
1044 : return mas_walk(&vmi->mas);
1045 : }
1046 :
1047 : /* Store a VMA with preallocated memory */
1048 : static inline void vma_iter_store(struct vma_iterator *vmi,
1049 : struct vm_area_struct *vma)
1050 : {
1051 :
1052 : #if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
1053 : if (MAS_WARN_ON(&vmi->mas, vmi->mas.node != MAS_START &&
1054 : vmi->mas.index > vma->vm_start)) {
1055 : pr_warn("%lx > %lx\n store vma %lx-%lx\n into slot %lx-%lx\n",
1056 : vmi->mas.index, vma->vm_start, vma->vm_start,
1057 : vma->vm_end, vmi->mas.index, vmi->mas.last);
1058 : }
1059 : if (MAS_WARN_ON(&vmi->mas, vmi->mas.node != MAS_START &&
1060 : vmi->mas.last < vma->vm_start)) {
1061 : pr_warn("%lx < %lx\nstore vma %lx-%lx\ninto slot %lx-%lx\n",
1062 : vmi->mas.last, vma->vm_start, vma->vm_start, vma->vm_end,
1063 : vmi->mas.index, vmi->mas.last);
1064 : }
1065 : #endif
1066 :
1067 : if (vmi->mas.node != MAS_START &&
1068 : ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start)))
1069 : vma_iter_invalidate(vmi);
1070 :
1071 : vmi->mas.index = vma->vm_start;
1072 : vmi->mas.last = vma->vm_end - 1;
1073 : mas_store_prealloc(&vmi->mas, vma);
1074 : }
1075 :
1076 : static inline int vma_iter_store_gfp(struct vma_iterator *vmi,
1077 : struct vm_area_struct *vma, gfp_t gfp)
1078 : {
1079 : if (vmi->mas.node != MAS_START &&
1080 : ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start)))
1081 : vma_iter_invalidate(vmi);
1082 :
1083 : vmi->mas.index = vma->vm_start;
1084 : vmi->mas.last = vma->vm_end - 1;
1085 : mas_store_gfp(&vmi->mas, vma, gfp);
1086 : if (unlikely(mas_is_err(&vmi->mas)))
1087 : return -ENOMEM;
1088 :
1089 : return 0;
1090 : }
1091 :
1092 : /*
1093 : * VMA lock generalization
1094 : */
1095 : struct vma_prepare {
1096 : struct vm_area_struct *vma;
1097 : struct vm_area_struct *adj_next;
1098 : struct file *file;
1099 : struct address_space *mapping;
1100 : struct anon_vma *anon_vma;
1101 : struct vm_area_struct *insert;
1102 : struct vm_area_struct *remove;
1103 : struct vm_area_struct *remove2;
1104 : };
1105 : #endif /* __MM_INTERNAL_H */
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