xref: /linux/mm/internal.h (revision 19ba9cf70706629709a3304aa977d1dddcfadf43)
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_ATOMIC|__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 static inline void *folio_raw_mapping(struct folio *folio)
56 {
57 	unsigned long mapping = (unsigned long)folio->mapping;
58 
59 	return (void *)(mapping & ~PAGE_MAPPING_FLAGS);
60 }
61 
62 void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio,
63 						int nr_throttled);
64 static inline void acct_reclaim_writeback(struct folio *folio)
65 {
66 	pg_data_t *pgdat = folio_pgdat(folio);
67 	int nr_throttled = atomic_read(&pgdat->nr_writeback_throttled);
68 
69 	if (nr_throttled)
70 		__acct_reclaim_writeback(pgdat, folio, nr_throttled);
71 }
72 
73 static inline void wake_throttle_isolated(pg_data_t *pgdat)
74 {
75 	wait_queue_head_t *wqh;
76 
77 	wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED];
78 	if (waitqueue_active(wqh))
79 		wake_up(wqh);
80 }
81 
82 vm_fault_t do_swap_page(struct vm_fault *vmf);
83 void folio_rotate_reclaimable(struct folio *folio);
84 bool __folio_end_writeback(struct folio *folio);
85 void deactivate_file_folio(struct folio *folio);
86 void folio_activate(struct folio *folio);
87 
88 void free_pgtables(struct mmu_gather *tlb, struct maple_tree *mt,
89 		   struct vm_area_struct *start_vma, unsigned long floor,
90 		   unsigned long ceiling);
91 void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);
92 
93 struct zap_details;
94 void unmap_page_range(struct mmu_gather *tlb,
95 			     struct vm_area_struct *vma,
96 			     unsigned long addr, unsigned long end,
97 			     struct zap_details *details);
98 
99 void page_cache_ra_order(struct readahead_control *, struct file_ra_state *,
100 		unsigned int order);
101 void force_page_cache_ra(struct readahead_control *, unsigned long nr);
102 static inline void force_page_cache_readahead(struct address_space *mapping,
103 		struct file *file, pgoff_t index, unsigned long nr_to_read)
104 {
105 	DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index);
106 	force_page_cache_ra(&ractl, nr_to_read);
107 }
108 
109 unsigned find_lock_entries(struct address_space *mapping, pgoff_t *start,
110 		pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
111 unsigned find_get_entries(struct address_space *mapping, pgoff_t *start,
112 		pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
113 void filemap_free_folio(struct address_space *mapping, struct folio *folio);
114 int truncate_inode_folio(struct address_space *mapping, struct folio *folio);
115 bool truncate_inode_partial_folio(struct folio *folio, loff_t start,
116 		loff_t end);
117 long invalidate_inode_page(struct page *page);
118 unsigned long invalidate_mapping_pagevec(struct address_space *mapping,
119 		pgoff_t start, pgoff_t end, unsigned long *nr_pagevec);
120 
121 /**
122  * folio_evictable - Test whether a folio is evictable.
123  * @folio: The folio to test.
124  *
125  * Test whether @folio is evictable -- i.e., should be placed on
126  * active/inactive lists vs unevictable list.
127  *
128  * Reasons folio might not be evictable:
129  * 1. folio's mapping marked unevictable
130  * 2. One of the pages in the folio is part of an mlocked VMA
131  */
132 static inline bool folio_evictable(struct folio *folio)
133 {
134 	bool ret;
135 
136 	/* Prevent address_space of inode and swap cache from being freed */
137 	rcu_read_lock();
138 	ret = !mapping_unevictable(folio_mapping(folio)) &&
139 			!folio_test_mlocked(folio);
140 	rcu_read_unlock();
141 	return ret;
142 }
143 
144 static inline bool page_evictable(struct page *page)
145 {
146 	bool ret;
147 
148 	/* Prevent address_space of inode and swap cache from being freed */
149 	rcu_read_lock();
150 	ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
151 	rcu_read_unlock();
152 	return ret;
153 }
154 
155 /*
156  * Turn a non-refcounted page (->_refcount == 0) into refcounted with
157  * a count of one.
158  */
159 static inline void set_page_refcounted(struct page *page)
160 {
161 	VM_BUG_ON_PAGE(PageTail(page), page);
162 	VM_BUG_ON_PAGE(page_ref_count(page), page);
163 	set_page_count(page, 1);
164 }
165 
166 extern unsigned long highest_memmap_pfn;
167 
168 /*
169  * Maximum number of reclaim retries without progress before the OOM
170  * killer is consider the only way forward.
171  */
172 #define MAX_RECLAIM_RETRIES 16
173 
174 /*
175  * in mm/early_ioremap.c
176  */
177 pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr,
178 					unsigned long size, pgprot_t prot);
179 
180 /*
181  * in mm/vmscan.c:
182  */
183 int isolate_lru_page(struct page *page);
184 int folio_isolate_lru(struct folio *folio);
185 void putback_lru_page(struct page *page);
186 void folio_putback_lru(struct folio *folio);
187 extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason);
188 
189 /*
190  * in mm/rmap.c:
191  */
192 pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
193 
194 /*
195  * in mm/page_alloc.c
196  */
197 
198 /*
199  * Structure for holding the mostly immutable allocation parameters passed
200  * between functions involved in allocations, including the alloc_pages*
201  * family of functions.
202  *
203  * nodemask, migratetype and highest_zoneidx are initialized only once in
204  * __alloc_pages() and then never change.
205  *
206  * zonelist, preferred_zone and highest_zoneidx are set first in
207  * __alloc_pages() for the fast path, and might be later changed
208  * in __alloc_pages_slowpath(). All other functions pass the whole structure
209  * by a const pointer.
210  */
211 struct alloc_context {
212 	struct zonelist *zonelist;
213 	nodemask_t *nodemask;
214 	struct zoneref *preferred_zoneref;
215 	int migratetype;
216 
217 	/*
218 	 * highest_zoneidx represents highest usable zone index of
219 	 * the allocation request. Due to the nature of the zone,
220 	 * memory on lower zone than the highest_zoneidx will be
221 	 * protected by lowmem_reserve[highest_zoneidx].
222 	 *
223 	 * highest_zoneidx is also used by reclaim/compaction to limit
224 	 * the target zone since higher zone than this index cannot be
225 	 * usable for this allocation request.
226 	 */
227 	enum zone_type highest_zoneidx;
228 	bool spread_dirty_pages;
229 };
230 
231 /*
232  * This function returns the order of a free page in the buddy system. In
233  * general, page_zone(page)->lock must be held by the caller to prevent the
234  * page from being allocated in parallel and returning garbage as the order.
235  * If a caller does not hold page_zone(page)->lock, it must guarantee that the
236  * page cannot be allocated or merged in parallel. Alternatively, it must
237  * handle invalid values gracefully, and use buddy_order_unsafe() below.
238  */
239 static inline unsigned int buddy_order(struct page *page)
240 {
241 	/* PageBuddy() must be checked by the caller */
242 	return page_private(page);
243 }
244 
245 /*
246  * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
247  * PageBuddy() should be checked first by the caller to minimize race window,
248  * and invalid values must be handled gracefully.
249  *
250  * READ_ONCE is used so that if the caller assigns the result into a local
251  * variable and e.g. tests it for valid range before using, the compiler cannot
252  * decide to remove the variable and inline the page_private(page) multiple
253  * times, potentially observing different values in the tests and the actual
254  * use of the result.
255  */
256 #define buddy_order_unsafe(page)	READ_ONCE(page_private(page))
257 
258 /*
259  * This function checks whether a page is free && is the buddy
260  * we can coalesce a page and its buddy if
261  * (a) the buddy is not in a hole (check before calling!) &&
262  * (b) the buddy is in the buddy system &&
263  * (c) a page and its buddy have the same order &&
264  * (d) a page and its buddy are in the same zone.
265  *
266  * For recording whether a page is in the buddy system, we set PageBuddy.
267  * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
268  *
269  * For recording page's order, we use page_private(page).
270  */
271 static inline bool page_is_buddy(struct page *page, struct page *buddy,
272 				 unsigned int order)
273 {
274 	if (!page_is_guard(buddy) && !PageBuddy(buddy))
275 		return false;
276 
277 	if (buddy_order(buddy) != order)
278 		return false;
279 
280 	/*
281 	 * zone check is done late to avoid uselessly calculating
282 	 * zone/node ids for pages that could never merge.
283 	 */
284 	if (page_zone_id(page) != page_zone_id(buddy))
285 		return false;
286 
287 	VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
288 
289 	return true;
290 }
291 
292 /*
293  * Locate the struct page for both the matching buddy in our
294  * pair (buddy1) and the combined O(n+1) page they form (page).
295  *
296  * 1) Any buddy B1 will have an order O twin B2 which satisfies
297  * the following equation:
298  *     B2 = B1 ^ (1 << O)
299  * For example, if the starting buddy (buddy2) is #8 its order
300  * 1 buddy is #10:
301  *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
302  *
303  * 2) Any buddy B will have an order O+1 parent P which
304  * satisfies the following equation:
305  *     P = B & ~(1 << O)
306  *
307  * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
308  */
309 static inline unsigned long
310 __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
311 {
312 	return page_pfn ^ (1 << order);
313 }
314 
315 /*
316  * Find the buddy of @page and validate it.
317  * @page: The input page
318  * @pfn: The pfn of the page, it saves a call to page_to_pfn() when the
319  *       function is used in the performance-critical __free_one_page().
320  * @order: The order of the page
321  * @buddy_pfn: The output pointer to the buddy pfn, it also saves a call to
322  *             page_to_pfn().
323  *
324  * The found buddy can be a non PageBuddy, out of @page's zone, or its order is
325  * not the same as @page. The validation is necessary before use it.
326  *
327  * Return: the found buddy page or NULL if not found.
328  */
329 static inline struct page *find_buddy_page_pfn(struct page *page,
330 			unsigned long pfn, unsigned int order, unsigned long *buddy_pfn)
331 {
332 	unsigned long __buddy_pfn = __find_buddy_pfn(pfn, order);
333 	struct page *buddy;
334 
335 	buddy = page + (__buddy_pfn - pfn);
336 	if (buddy_pfn)
337 		*buddy_pfn = __buddy_pfn;
338 
339 	if (page_is_buddy(page, buddy, order))
340 		return buddy;
341 	return NULL;
342 }
343 
344 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
345 				unsigned long end_pfn, struct zone *zone);
346 
347 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
348 				unsigned long end_pfn, struct zone *zone)
349 {
350 	if (zone->contiguous)
351 		return pfn_to_page(start_pfn);
352 
353 	return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
354 }
355 
356 extern int __isolate_free_page(struct page *page, unsigned int order);
357 extern void __putback_isolated_page(struct page *page, unsigned int order,
358 				    int mt);
359 extern void memblock_free_pages(struct page *page, unsigned long pfn,
360 					unsigned int order);
361 extern void __free_pages_core(struct page *page, unsigned int order);
362 extern void prep_compound_page(struct page *page, unsigned int order);
363 extern void post_alloc_hook(struct page *page, unsigned int order,
364 					gfp_t gfp_flags);
365 extern int user_min_free_kbytes;
366 
367 extern void free_unref_page(struct page *page, unsigned int order);
368 extern void free_unref_page_list(struct list_head *list);
369 
370 extern void zone_pcp_reset(struct zone *zone);
371 extern void zone_pcp_disable(struct zone *zone);
372 extern void zone_pcp_enable(struct zone *zone);
373 
374 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
375 			  phys_addr_t min_addr,
376 			  int nid, bool exact_nid);
377 
378 int split_free_page(struct page *free_page,
379 			unsigned int order, unsigned long split_pfn_offset);
380 
381 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
382 
383 /*
384  * in mm/compaction.c
385  */
386 /*
387  * compact_control is used to track pages being migrated and the free pages
388  * they are being migrated to during memory compaction. The free_pfn starts
389  * at the end of a zone and migrate_pfn begins at the start. Movable pages
390  * are moved to the end of a zone during a compaction run and the run
391  * completes when free_pfn <= migrate_pfn
392  */
393 struct compact_control {
394 	struct list_head freepages;	/* List of free pages to migrate to */
395 	struct list_head migratepages;	/* List of pages being migrated */
396 	unsigned int nr_freepages;	/* Number of isolated free pages */
397 	unsigned int nr_migratepages;	/* Number of pages to migrate */
398 	unsigned long free_pfn;		/* isolate_freepages search base */
399 	/*
400 	 * Acts as an in/out parameter to page isolation for migration.
401 	 * isolate_migratepages uses it as a search base.
402 	 * isolate_migratepages_block will update the value to the next pfn
403 	 * after the last isolated one.
404 	 */
405 	unsigned long migrate_pfn;
406 	unsigned long fast_start_pfn;	/* a pfn to start linear scan from */
407 	struct zone *zone;
408 	unsigned long total_migrate_scanned;
409 	unsigned long total_free_scanned;
410 	unsigned short fast_search_fail;/* failures to use free list searches */
411 	short search_order;		/* order to start a fast search at */
412 	const gfp_t gfp_mask;		/* gfp mask of a direct compactor */
413 	int order;			/* order a direct compactor needs */
414 	int migratetype;		/* migratetype of direct compactor */
415 	const unsigned int alloc_flags;	/* alloc flags of a direct compactor */
416 	const int highest_zoneidx;	/* zone index of a direct compactor */
417 	enum migrate_mode mode;		/* Async or sync migration mode */
418 	bool ignore_skip_hint;		/* Scan blocks even if marked skip */
419 	bool no_set_skip_hint;		/* Don't mark blocks for skipping */
420 	bool ignore_block_suitable;	/* Scan blocks considered unsuitable */
421 	bool direct_compaction;		/* False from kcompactd or /proc/... */
422 	bool proactive_compaction;	/* kcompactd proactive compaction */
423 	bool whole_zone;		/* Whole zone should/has been scanned */
424 	bool contended;			/* Signal lock contention */
425 	bool rescan;			/* Rescanning the same pageblock */
426 	bool alloc_contig;		/* alloc_contig_range allocation */
427 };
428 
429 /*
430  * Used in direct compaction when a page should be taken from the freelists
431  * immediately when one is created during the free path.
432  */
433 struct capture_control {
434 	struct compact_control *cc;
435 	struct page *page;
436 };
437 
438 unsigned long
439 isolate_freepages_range(struct compact_control *cc,
440 			unsigned long start_pfn, unsigned long end_pfn);
441 int
442 isolate_migratepages_range(struct compact_control *cc,
443 			   unsigned long low_pfn, unsigned long end_pfn);
444 
445 int __alloc_contig_migrate_range(struct compact_control *cc,
446 					unsigned long start, unsigned long end);
447 #endif
448 int find_suitable_fallback(struct free_area *area, unsigned int order,
449 			int migratetype, bool only_stealable, bool *can_steal);
450 
451 /*
452  * These three helpers classifies VMAs for virtual memory accounting.
453  */
454 
455 /*
456  * Executable code area - executable, not writable, not stack
457  */
458 static inline bool is_exec_mapping(vm_flags_t flags)
459 {
460 	return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
461 }
462 
463 /*
464  * Stack area - automatically grows in one direction
465  *
466  * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
467  * do_mmap() forbids all other combinations.
468  */
469 static inline bool is_stack_mapping(vm_flags_t flags)
470 {
471 	return (flags & VM_STACK) == VM_STACK;
472 }
473 
474 /*
475  * Data area - private, writable, not stack
476  */
477 static inline bool is_data_mapping(vm_flags_t flags)
478 {
479 	return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
480 }
481 
482 /* mm/util.c */
483 struct anon_vma *folio_anon_vma(struct folio *folio);
484 
485 #ifdef CONFIG_MMU
486 void unmap_mapping_folio(struct folio *folio);
487 extern long populate_vma_page_range(struct vm_area_struct *vma,
488 		unsigned long start, unsigned long end, int *locked);
489 extern long faultin_vma_page_range(struct vm_area_struct *vma,
490 				   unsigned long start, unsigned long end,
491 				   bool write, int *locked);
492 extern int mlock_future_check(struct mm_struct *mm, unsigned long flags,
493 			      unsigned long len);
494 /*
495  * mlock_vma_page() and munlock_vma_page():
496  * should be called with vma's mmap_lock held for read or write,
497  * under page table lock for the pte/pmd being added or removed.
498  *
499  * mlock is usually called at the end of page_add_*_rmap(),
500  * munlock at the end of page_remove_rmap(); but new anon
501  * pages are managed by lru_cache_add_inactive_or_unevictable()
502  * calling mlock_new_page().
503  *
504  * @compound is used to include pmd mappings of THPs, but filter out
505  * pte mappings of THPs, which cannot be consistently counted: a pte
506  * mapping of the THP head cannot be distinguished by the page alone.
507  */
508 void mlock_folio(struct folio *folio);
509 static inline void mlock_vma_folio(struct folio *folio,
510 			struct vm_area_struct *vma, bool compound)
511 {
512 	/*
513 	 * The VM_SPECIAL check here serves two purposes.
514 	 * 1) VM_IO check prevents migration from double-counting during mlock.
515 	 * 2) Although mmap_region() and mlock_fixup() take care that VM_LOCKED
516 	 *    is never left set on a VM_SPECIAL vma, there is an interval while
517 	 *    file->f_op->mmap() is using vm_insert_page(s), when VM_LOCKED may
518 	 *    still be set while VM_SPECIAL bits are added: so ignore it then.
519 	 */
520 	if (unlikely((vma->vm_flags & (VM_LOCKED|VM_SPECIAL)) == VM_LOCKED) &&
521 	    (compound || !folio_test_large(folio)))
522 		mlock_folio(folio);
523 }
524 
525 static inline void mlock_vma_page(struct page *page,
526 			struct vm_area_struct *vma, bool compound)
527 {
528 	mlock_vma_folio(page_folio(page), vma, compound);
529 }
530 
531 void munlock_page(struct page *page);
532 static inline void munlock_vma_page(struct page *page,
533 			struct vm_area_struct *vma, bool compound)
534 {
535 	if (unlikely(vma->vm_flags & VM_LOCKED) &&
536 	    (compound || !PageTransCompound(page)))
537 		munlock_page(page);
538 }
539 void mlock_new_page(struct page *page);
540 bool need_mlock_page_drain(int cpu);
541 void mlock_page_drain_local(void);
542 void mlock_page_drain_remote(int cpu);
543 
544 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
545 
546 /*
547  * Return the start of user virtual address at the specific offset within
548  * a vma.
549  */
550 static inline unsigned long
551 vma_pgoff_address(pgoff_t pgoff, unsigned long nr_pages,
552 		  struct vm_area_struct *vma)
553 {
554 	unsigned long address;
555 
556 	if (pgoff >= vma->vm_pgoff) {
557 		address = vma->vm_start +
558 			((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
559 		/* Check for address beyond vma (or wrapped through 0?) */
560 		if (address < vma->vm_start || address >= vma->vm_end)
561 			address = -EFAULT;
562 	} else if (pgoff + nr_pages - 1 >= vma->vm_pgoff) {
563 		/* Test above avoids possibility of wrap to 0 on 32-bit */
564 		address = vma->vm_start;
565 	} else {
566 		address = -EFAULT;
567 	}
568 	return address;
569 }
570 
571 /*
572  * Return the start of user virtual address of a page within a vma.
573  * Returns -EFAULT if all of the page is outside the range of vma.
574  * If page is a compound head, the entire compound page is considered.
575  */
576 static inline unsigned long
577 vma_address(struct page *page, struct vm_area_struct *vma)
578 {
579 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
580 	return vma_pgoff_address(page_to_pgoff(page), compound_nr(page), vma);
581 }
582 
583 /*
584  * Then at what user virtual address will none of the range be found in vma?
585  * Assumes that vma_address() already returned a good starting address.
586  */
587 static inline unsigned long vma_address_end(struct page_vma_mapped_walk *pvmw)
588 {
589 	struct vm_area_struct *vma = pvmw->vma;
590 	pgoff_t pgoff;
591 	unsigned long address;
592 
593 	/* Common case, plus ->pgoff is invalid for KSM */
594 	if (pvmw->nr_pages == 1)
595 		return pvmw->address + PAGE_SIZE;
596 
597 	pgoff = pvmw->pgoff + pvmw->nr_pages;
598 	address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
599 	/* Check for address beyond vma (or wrapped through 0?) */
600 	if (address < vma->vm_start || address > vma->vm_end)
601 		address = vma->vm_end;
602 	return address;
603 }
604 
605 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
606 						    struct file *fpin)
607 {
608 	int flags = vmf->flags;
609 
610 	if (fpin)
611 		return fpin;
612 
613 	/*
614 	 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
615 	 * anything, so we only pin the file and drop the mmap_lock if only
616 	 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
617 	 */
618 	if (fault_flag_allow_retry_first(flags) &&
619 	    !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
620 		fpin = get_file(vmf->vma->vm_file);
621 		mmap_read_unlock(vmf->vma->vm_mm);
622 	}
623 	return fpin;
624 }
625 #else /* !CONFIG_MMU */
626 static inline void unmap_mapping_folio(struct folio *folio) { }
627 static inline void mlock_vma_page(struct page *page,
628 			struct vm_area_struct *vma, bool compound) { }
629 static inline void munlock_vma_page(struct page *page,
630 			struct vm_area_struct *vma, bool compound) { }
631 static inline void mlock_new_page(struct page *page) { }
632 static inline bool need_mlock_page_drain(int cpu) { return false; }
633 static inline void mlock_page_drain_local(void) { }
634 static inline void mlock_page_drain_remote(int cpu) { }
635 static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
636 {
637 }
638 #endif /* !CONFIG_MMU */
639 
640 /* Memory initialisation debug and verification */
641 enum mminit_level {
642 	MMINIT_WARNING,
643 	MMINIT_VERIFY,
644 	MMINIT_TRACE
645 };
646 
647 #ifdef CONFIG_DEBUG_MEMORY_INIT
648 
649 extern int mminit_loglevel;
650 
651 #define mminit_dprintk(level, prefix, fmt, arg...) \
652 do { \
653 	if (level < mminit_loglevel) { \
654 		if (level <= MMINIT_WARNING) \
655 			pr_warn("mminit::" prefix " " fmt, ##arg);	\
656 		else \
657 			printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
658 	} \
659 } while (0)
660 
661 extern void mminit_verify_pageflags_layout(void);
662 extern void mminit_verify_zonelist(void);
663 #else
664 
665 static inline void mminit_dprintk(enum mminit_level level,
666 				const char *prefix, const char *fmt, ...)
667 {
668 }
669 
670 static inline void mminit_verify_pageflags_layout(void)
671 {
672 }
673 
674 static inline void mminit_verify_zonelist(void)
675 {
676 }
677 #endif /* CONFIG_DEBUG_MEMORY_INIT */
678 
679 #define NODE_RECLAIM_NOSCAN	-2
680 #define NODE_RECLAIM_FULL	-1
681 #define NODE_RECLAIM_SOME	0
682 #define NODE_RECLAIM_SUCCESS	1
683 
684 #ifdef CONFIG_NUMA
685 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
686 extern int find_next_best_node(int node, nodemask_t *used_node_mask);
687 #else
688 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
689 				unsigned int order)
690 {
691 	return NODE_RECLAIM_NOSCAN;
692 }
693 static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
694 {
695 	return NUMA_NO_NODE;
696 }
697 #endif
698 
699 /*
700  * mm/memory-failure.c
701  */
702 extern int hwpoison_filter(struct page *p);
703 
704 extern u32 hwpoison_filter_dev_major;
705 extern u32 hwpoison_filter_dev_minor;
706 extern u64 hwpoison_filter_flags_mask;
707 extern u64 hwpoison_filter_flags_value;
708 extern u64 hwpoison_filter_memcg;
709 extern u32 hwpoison_filter_enable;
710 
711 extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
712         unsigned long, unsigned long,
713         unsigned long, unsigned long);
714 
715 extern void set_pageblock_order(void);
716 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
717 					    struct list_head *page_list);
718 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
719 #define ALLOC_WMARK_MIN		WMARK_MIN
720 #define ALLOC_WMARK_LOW		WMARK_LOW
721 #define ALLOC_WMARK_HIGH	WMARK_HIGH
722 #define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
723 
724 /* Mask to get the watermark bits */
725 #define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
726 
727 /*
728  * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
729  * cannot assume a reduced access to memory reserves is sufficient for
730  * !MMU
731  */
732 #ifdef CONFIG_MMU
733 #define ALLOC_OOM		0x08
734 #else
735 #define ALLOC_OOM		ALLOC_NO_WATERMARKS
736 #endif
737 
738 #define ALLOC_HARDER		 0x10 /* try to alloc harder */
739 #define ALLOC_HIGH		 0x20 /* __GFP_HIGH set */
740 #define ALLOC_CPUSET		 0x40 /* check for correct cpuset */
741 #define ALLOC_CMA		 0x80 /* allow allocations from CMA areas */
742 #ifdef CONFIG_ZONE_DMA32
743 #define ALLOC_NOFRAGMENT	0x100 /* avoid mixing pageblock types */
744 #else
745 #define ALLOC_NOFRAGMENT	  0x0
746 #endif
747 #define ALLOC_KSWAPD		0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
748 
749 enum ttu_flags;
750 struct tlbflush_unmap_batch;
751 
752 
753 /*
754  * only for MM internal work items which do not depend on
755  * any allocations or locks which might depend on allocations
756  */
757 extern struct workqueue_struct *mm_percpu_wq;
758 
759 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
760 void try_to_unmap_flush(void);
761 void try_to_unmap_flush_dirty(void);
762 void flush_tlb_batched_pending(struct mm_struct *mm);
763 #else
764 static inline void try_to_unmap_flush(void)
765 {
766 }
767 static inline void try_to_unmap_flush_dirty(void)
768 {
769 }
770 static inline void flush_tlb_batched_pending(struct mm_struct *mm)
771 {
772 }
773 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
774 
775 extern const struct trace_print_flags pageflag_names[];
776 extern const struct trace_print_flags vmaflag_names[];
777 extern const struct trace_print_flags gfpflag_names[];
778 
779 static inline bool is_migrate_highatomic(enum migratetype migratetype)
780 {
781 	return migratetype == MIGRATE_HIGHATOMIC;
782 }
783 
784 static inline bool is_migrate_highatomic_page(struct page *page)
785 {
786 	return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
787 }
788 
789 void setup_zone_pageset(struct zone *zone);
790 
791 struct migration_target_control {
792 	int nid;		/* preferred node id */
793 	nodemask_t *nmask;
794 	gfp_t gfp_mask;
795 };
796 
797 /*
798  * mm/vmalloc.c
799  */
800 #ifdef CONFIG_MMU
801 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
802                 pgprot_t prot, struct page **pages, unsigned int page_shift);
803 #else
804 static inline
805 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
806                 pgprot_t prot, struct page **pages, unsigned int page_shift)
807 {
808 	return -EINVAL;
809 }
810 #endif
811 
812 int __vmap_pages_range_noflush(unsigned long addr, unsigned long end,
813 			       pgprot_t prot, struct page **pages,
814 			       unsigned int page_shift);
815 
816 void vunmap_range_noflush(unsigned long start, unsigned long end);
817 
818 void __vunmap_range_noflush(unsigned long start, unsigned long end);
819 
820 int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
821 		      unsigned long addr, int page_nid, int *flags);
822 
823 void free_zone_device_page(struct page *page);
824 int migrate_device_coherent_page(struct page *page);
825 
826 /*
827  * mm/gup.c
828  */
829 struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
830 
831 extern bool mirrored_kernelcore;
832 
833 static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma)
834 {
835 	/*
836 	 * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty
837 	 * enablements, because when without soft-dirty being compiled in,
838 	 * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY)
839 	 * will be constantly true.
840 	 */
841 	if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
842 		return false;
843 
844 	/*
845 	 * Soft-dirty is kind of special: its tracking is enabled when the
846 	 * vma flags not set.
847 	 */
848 	return !(vma->vm_flags & VM_SOFTDIRTY);
849 }
850 
851 #endif	/* __MM_INTERNAL_H */
852