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/swap.h>
14 #include <linux/rmap.h>
15 #include <linux/tracepoint-defs.h>
16 #include <linux/types.h>
17 #include <linux/reclaim_acct.h>
18 
19 struct folio_batch;
20 
21 /*
22  * The set of flags that only affect watermark checking and reclaim
23  * behaviour. This is used by the MM to obey the caller constraints
24  * about IO, FS and watermark checking while ignoring placement
25  * hints such as HIGHMEM usage.
26  */
27 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
28 			__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\
29 			__GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
30 			__GFP_NOLOCKDEP)
31 
32 /* The GFP flags allowed during early boot */
33 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
34 
35 /* Control allocation cpuset and node placement constraints */
36 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
37 
38 /* Do not use these with a slab allocator */
39 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
40 
41 enum reclaim_invoker {
42 	ALL,
43 	KSWAPD,
44 	ZSWAPD,
45 	DIRECT_RECLAIM,
46 	NODE_RECLAIM,
47 	SOFT_LIMIT,
48 	RCC_RECLAIM,
49 	FILE_RECLAIM,
50 	ANON_RECLAIM
51 };
52 
53 struct scan_control {
54 	/* How many pages shrink_list() should reclaim */
55 	unsigned long nr_to_reclaim;
56 
57 	/*
58 	 * Nodemask of nodes allowed by the caller. If NULL, all nodes
59 	 * are scanned.
60 	 */
61 	nodemask_t	*nodemask;
62 
63 	/*
64 	 * The memory cgroup that hit its limit and as a result is the
65 	 * primary target of this reclaim invocation.
66 	 */
67 	struct mem_cgroup *target_mem_cgroup;
68 
69 	/*
70 	 * Scan pressure balancing between anon and file LRUs
71 	 */
72 	unsigned long	anon_cost;
73 	unsigned long	file_cost;
74 
75 	/* Can active folios be deactivated as part of reclaim? */
76 #define DEACTIVATE_ANON 1
77 #define DEACTIVATE_FILE 2
78 	unsigned int may_deactivate:2;
79 	unsigned int force_deactivate:1;
80 	unsigned int skipped_deactivate:1;
81 
82 	/* Writepage batching in laptop mode; RECLAIM_WRITE */
83 	unsigned int may_writepage:1;
84 
85 	/* Can mapped folios be reclaimed? */
86 	unsigned int may_unmap:1;
87 
88 	/* Can folios be swapped as part of reclaim? */
89 	unsigned int may_swap:1;
90 
91 	/* Proactive reclaim invoked by userspace through memory.reclaim */
92 	unsigned int proactive:1;
93 
94 	/*
95 	 * Cgroup memory below memory.low is protected as long as we
96 	 * don't threaten to OOM. If any cgroup is reclaimed at
97 	 * reduced force or passed over entirely due to its memory.low
98 	 * setting (memcg_low_skipped), and nothing is reclaimed as a
99 	 * result, then go back for one more cycle that reclaims the protected
100 	 * memory (memcg_low_reclaim) to avert OOM.
101 	 */
102 	unsigned int memcg_low_reclaim:1;
103 	unsigned int memcg_low_skipped:1;
104 
105 	unsigned int hibernation_mode:1;
106 
107 	/* One of the zones is ready for compaction */
108 	unsigned int compaction_ready:1;
109 
110 	/* There is easily reclaimable cold cache in the current node */
111 	unsigned int cache_trim_mode:1;
112 
113 	/* The file folios on the current node are dangerously low */
114 	unsigned int file_is_tiny:1;
115 
116 	/* Always discard instead of demoting to lower tier memory */
117 	unsigned int no_demotion:1;
118 
119 	/* Allocation order */
120 	s8 order;
121 
122 	/* Scan (total_size >> priority) pages at once */
123 	s8 priority;
124 
125 	/* The highest zone to isolate folios for reclaim from */
126 	s8 reclaim_idx;
127 
128 	/* This context's GFP mask */
129 	gfp_t gfp_mask;
130 
131 	/* Incremented by the number of inactive pages that were scanned */
132 	unsigned long nr_scanned;
133 
134 	/* Number of pages freed so far during a call to shrink_zones() */
135 	unsigned long nr_reclaimed;
136 
137 	struct {
138 		unsigned int dirty;
139 		unsigned int unqueued_dirty;
140 		unsigned int congested;
141 		unsigned int writeback;
142 		unsigned int immediate;
143 		unsigned int file_taken;
144 		unsigned int taken;
145 	} nr;
146 
147 	enum reclaim_invoker invoker;
148 	u32 isolate_count;
149 	unsigned long nr_scanned_anon;
150 	unsigned long nr_scanned_file;
151 	unsigned long nr_reclaimed_anon;
152 	unsigned long nr_reclaimed_file;
153 
154 	/* for recording the reclaimed slab by now */
155 	struct reclaim_state reclaim_state;
156 };
157 
158 enum scan_balance {
159 	SCAN_EQUAL,
160 	SCAN_FRACT,
161 	SCAN_ANON,
162 	SCAN_FILE,
163 };
164 
165 /*
166  * Different from WARN_ON_ONCE(), no warning will be issued
167  * when we specify __GFP_NOWARN.
168  */
169 #define WARN_ON_ONCE_GFP(cond, gfp)	({				\
170 	static bool __section(".data.once") __warned;			\
171 	int __ret_warn_once = !!(cond);					\
172 									\
173 	if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \
174 		__warned = true;					\
175 		WARN_ON(1);						\
176 	}								\
177 	unlikely(__ret_warn_once);					\
178 })
179 
180 void page_writeback_init(void);
181 
182 /*
183  * If a 16GB hugetlb folio were mapped by PTEs of all of its 4kB pages,
184  * its nr_pages_mapped would be 0x400000: choose the COMPOUND_MAPPED bit
185  * above that range, instead of 2*(PMD_SIZE/PAGE_SIZE).  Hugetlb currently
186  * leaves nr_pages_mapped at 0, but avoid surprise if it participates later.
187  */
188 #define COMPOUND_MAPPED		0x800000
189 #define FOLIO_PAGES_MAPPED	(COMPOUND_MAPPED - 1)
190 
191 /*
192  * Flags passed to __show_mem() and show_free_areas() to suppress output in
193  * various contexts.
194  */
195 #define SHOW_MEM_FILTER_NODES		(0x0001u)	/* disallowed nodes */
196 
197 /*
198  * How many individual pages have an elevated _mapcount.  Excludes
199  * the folio's entire_mapcount.
200  */
folio_nr_pages_mapped(struct folio *folio)201 static inline int folio_nr_pages_mapped(struct folio *folio)
202 {
203 	return atomic_read(&folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED;
204 }
205 
folio_raw_mapping(struct folio *folio)206 static inline void *folio_raw_mapping(struct folio *folio)
207 {
208 	unsigned long mapping = (unsigned long)folio->mapping;
209 
210 	return (void *)(mapping & ~PAGE_MAPPING_FLAGS);
211 }
212 
213 void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio,
214 						int nr_throttled);
acct_reclaim_writeback(struct folio *folio)215 static inline void acct_reclaim_writeback(struct folio *folio)
216 {
217 	pg_data_t *pgdat = folio_pgdat(folio);
218 	int nr_throttled = atomic_read(&pgdat->nr_writeback_throttled);
219 
220 	if (nr_throttled)
221 		__acct_reclaim_writeback(pgdat, folio, nr_throttled);
222 }
223 
wake_throttle_isolated(pg_data_t *pgdat)224 static inline void wake_throttle_isolated(pg_data_t *pgdat)
225 {
226 	wait_queue_head_t *wqh;
227 
228 	wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED];
229 	if (waitqueue_active(wqh))
230 		wake_up(wqh);
231 }
232 
233 vm_fault_t do_swap_page(struct vm_fault *vmf);
234 void folio_rotate_reclaimable(struct folio *folio);
235 bool __folio_end_writeback(struct folio *folio);
236 void deactivate_file_folio(struct folio *folio);
237 void folio_activate(struct folio *folio);
238 
239 void free_pgtables(struct mmu_gather *tlb, struct ma_state *mas,
240 		   struct vm_area_struct *start_vma, unsigned long floor,
241 		   unsigned long ceiling, bool mm_wr_locked);
242 void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);
243 
244 struct zap_details;
245 void unmap_page_range(struct mmu_gather *tlb,
246 			     struct vm_area_struct *vma,
247 			     unsigned long addr, unsigned long end,
248 			     struct zap_details *details);
249 
250 void page_cache_ra_order(struct readahead_control *, struct file_ra_state *,
251 		unsigned int order);
252 void force_page_cache_ra(struct readahead_control *, unsigned long nr);
force_page_cache_readahead(struct address_space *mapping, struct file *file, pgoff_t index, unsigned long nr_to_read)253 static inline void force_page_cache_readahead(struct address_space *mapping,
254 		struct file *file, pgoff_t index, unsigned long nr_to_read)
255 {
256 	DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index);
257 	force_page_cache_ra(&ractl, nr_to_read);
258 }
259 
260 unsigned find_lock_entries(struct address_space *mapping, pgoff_t *start,
261 		pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
262 unsigned find_get_entries(struct address_space *mapping, pgoff_t *start,
263 		pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
264 void filemap_free_folio(struct address_space *mapping, struct folio *folio);
265 int truncate_inode_folio(struct address_space *mapping, struct folio *folio);
266 bool truncate_inode_partial_folio(struct folio *folio, loff_t start,
267 		loff_t end);
268 long invalidate_inode_page(struct page *page);
269 unsigned long mapping_try_invalidate(struct address_space *mapping,
270 		pgoff_t start, pgoff_t end, unsigned long *nr_failed);
271 
272 /**
273  * folio_evictable - Test whether a folio is evictable.
274  * @folio: The folio to test.
275  *
276  * Test whether @folio is evictable -- i.e., should be placed on
277  * active/inactive lists vs unevictable list.
278  *
279  * Reasons folio might not be evictable:
280  * 1. folio's mapping marked unevictable
281  * 2. One of the pages in the folio is part of an mlocked VMA
282  */
folio_evictable(struct folio *folio)283 static inline bool folio_evictable(struct folio *folio)
284 {
285 	bool ret;
286 
287 	/* Prevent address_space of inode and swap cache from being freed */
288 	rcu_read_lock();
289 	ret = !mapping_unevictable(folio_mapping(folio)) &&
290 			!folio_test_mlocked(folio);
291 	rcu_read_unlock();
292 	return ret;
293 }
294 
295 /*
296  * Turn a non-refcounted page (->_refcount == 0) into refcounted with
297  * a count of one.
298  */
set_page_refcounted(struct page *page)299 static inline void set_page_refcounted(struct page *page)
300 {
301 	VM_BUG_ON_PAGE(PageTail(page), page);
302 	VM_BUG_ON_PAGE(page_ref_count(page), page);
303 	set_page_count(page, 1);
304 }
305 
306 /*
307  * Return true if a folio needs ->release_folio() calling upon it.
308  */
folio_needs_release(struct folio *folio)309 static inline bool folio_needs_release(struct folio *folio)
310 {
311 	struct address_space *mapping = folio_mapping(folio);
312 
313 	return folio_has_private(folio) ||
314 		(mapping && mapping_release_always(mapping));
315 }
316 
317 extern unsigned long highest_memmap_pfn;
318 
319 /*
320  * Maximum number of reclaim retries without progress before the OOM
321  * killer is consider the only way forward.
322  */
323 #define MAX_RECLAIM_RETRIES 16
324 
325 /*
326  * in mm/vmscan.c:
327  */
328 #ifdef CONFIG_MEMORY_MONITOR
329 extern void kswapd_monitor_wake_up_queue(void);
330 #endif
331 bool isolate_lru_page(struct page *page);
332 bool folio_isolate_lru(struct folio *folio);
333 void putback_lru_page(struct page *page);
334 void folio_putback_lru(struct folio *folio);
335 extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason);
336 extern unsigned int shrink_folio_list(struct list_head *page_list, struct pglist_data *pgdat,
337 		struct scan_control *sc, struct reclaim_stat *stat, bool ignore_references);
338 extern unsigned long isolate_lru_folios(unsigned long nr_to_scan, struct lruvec *lruvec,
339 		struct list_head *dst, unsigned long *nr_scanned, struct scan_control *sc,
340 		enum lru_list lru);
341 extern unsigned move_folios_to_lru(struct lruvec *lruvec, struct list_head *list);
342 extern void shrink_active_list(unsigned long nr_to_scan, struct lruvec *lruvec,
343 		struct scan_control *sc, enum lru_list lru);
344 extern unsigned long shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
345 		struct scan_control *sc, enum lru_list lru);
346 extern void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc);
347 
348 /*
349  * in mm/rmap.c:
350  */
351 pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
352 
353 /*
354  * in mm/page_alloc.c
355  */
356 #define K(x) ((x) << (PAGE_SHIFT-10))
357 
358 extern char * const zone_names[MAX_NR_ZONES];
359 
360 /* perform sanity checks on struct pages being allocated or freed */
361 DECLARE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled);
362 
363 extern int min_free_kbytes;
364 
365 void setup_per_zone_wmarks(void);
366 void calculate_min_free_kbytes(void);
367 int __meminit init_per_zone_wmark_min(void);
368 void page_alloc_sysctl_init(void);
369 
370 /*
371  * Structure for holding the mostly immutable allocation parameters passed
372  * between functions involved in allocations, including the alloc_pages*
373  * family of functions.
374  *
375  * nodemask, migratetype and highest_zoneidx are initialized only once in
376  * __alloc_pages() and then never change.
377  *
378  * zonelist, preferred_zone and highest_zoneidx are set first in
379  * __alloc_pages() for the fast path, and might be later changed
380  * in __alloc_pages_slowpath(). All other functions pass the whole structure
381  * by a const pointer.
382  */
383 struct alloc_context {
384 	struct zonelist *zonelist;
385 	nodemask_t *nodemask;
386 	struct zoneref *preferred_zoneref;
387 	int migratetype;
388 
389 	/*
390 	 * highest_zoneidx represents highest usable zone index of
391 	 * the allocation request. Due to the nature of the zone,
392 	 * memory on lower zone than the highest_zoneidx will be
393 	 * protected by lowmem_reserve[highest_zoneidx].
394 	 *
395 	 * highest_zoneidx is also used by reclaim/compaction to limit
396 	 * the target zone since higher zone than this index cannot be
397 	 * usable for this allocation request.
398 	 */
399 	enum zone_type highest_zoneidx;
400 	bool spread_dirty_pages;
401 };
402 
403 /*
404  * This function returns the order of a free page in the buddy system. In
405  * general, page_zone(page)->lock must be held by the caller to prevent the
406  * page from being allocated in parallel and returning garbage as the order.
407  * If a caller does not hold page_zone(page)->lock, it must guarantee that the
408  * page cannot be allocated or merged in parallel. Alternatively, it must
409  * handle invalid values gracefully, and use buddy_order_unsafe() below.
410  */
buddy_order(struct page *page)411 static inline unsigned int buddy_order(struct page *page)
412 {
413 	/* PageBuddy() must be checked by the caller */
414 	return page_private(page);
415 }
416 
417 /*
418  * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
419  * PageBuddy() should be checked first by the caller to minimize race window,
420  * and invalid values must be handled gracefully.
421  *
422  * READ_ONCE is used so that if the caller assigns the result into a local
423  * variable and e.g. tests it for valid range before using, the compiler cannot
424  * decide to remove the variable and inline the page_private(page) multiple
425  * times, potentially observing different values in the tests and the actual
426  * use of the result.
427  */
428 #define buddy_order_unsafe(page)	READ_ONCE(page_private(page))
429 
430 /*
431  * This function checks whether a page is free && is the buddy
432  * we can coalesce a page and its buddy if
433  * (a) the buddy is not in a hole (check before calling!) &&
434  * (b) the buddy is in the buddy system &&
435  * (c) a page and its buddy have the same order &&
436  * (d) a page and its buddy are in the same zone.
437  *
438  * For recording whether a page is in the buddy system, we set PageBuddy.
439  * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
440  *
441  * For recording page's order, we use page_private(page).
442  */
page_is_buddy(struct page *page, struct page *buddy, unsigned int order)443 static inline bool page_is_buddy(struct page *page, struct page *buddy,
444 				 unsigned int order)
445 {
446 	if (!page_is_guard(buddy) && !PageBuddy(buddy))
447 		return false;
448 
449 	if (buddy_order(buddy) != order)
450 		return false;
451 
452 	/*
453 	 * zone check is done late to avoid uselessly calculating
454 	 * zone/node ids for pages that could never merge.
455 	 */
456 	if (page_zone_id(page) != page_zone_id(buddy))
457 		return false;
458 
459 	VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
460 
461 	return true;
462 }
463 
464 /*
465  * Locate the struct page for both the matching buddy in our
466  * pair (buddy1) and the combined O(n+1) page they form (page).
467  *
468  * 1) Any buddy B1 will have an order O twin B2 which satisfies
469  * the following equation:
470  *     B2 = B1 ^ (1 << O)
471  * For example, if the starting buddy (buddy2) is #8 its order
472  * 1 buddy is #10:
473  *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
474  *
475  * 2) Any buddy B will have an order O+1 parent P which
476  * satisfies the following equation:
477  *     P = B & ~(1 << O)
478  *
479  * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
480  */
481 static inline unsigned long
__find_buddy_pfn(unsigned long page_pfn, unsigned int order)482 __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
483 {
484 	return page_pfn ^ (1 << order);
485 }
486 
487 /*
488  * Find the buddy of @page and validate it.
489  * @page: The input page
490  * @pfn: The pfn of the page, it saves a call to page_to_pfn() when the
491  *       function is used in the performance-critical __free_one_page().
492  * @order: The order of the page
493  * @buddy_pfn: The output pointer to the buddy pfn, it also saves a call to
494  *             page_to_pfn().
495  *
496  * The found buddy can be a non PageBuddy, out of @page's zone, or its order is
497  * not the same as @page. The validation is necessary before use it.
498  *
499  * Return: the found buddy page or NULL if not found.
500  */
find_buddy_page_pfn(struct page *page, unsigned long pfn, unsigned int order, unsigned long *buddy_pfn)501 static inline struct page *find_buddy_page_pfn(struct page *page,
502 			unsigned long pfn, unsigned int order, unsigned long *buddy_pfn)
503 {
504 	unsigned long __buddy_pfn = __find_buddy_pfn(pfn, order);
505 	struct page *buddy;
506 
507 	buddy = page + (__buddy_pfn - pfn);
508 	if (buddy_pfn)
509 		*buddy_pfn = __buddy_pfn;
510 
511 	if (page_is_buddy(page, buddy, order))
512 		return buddy;
513 	return NULL;
514 }
515 
516 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
517 				unsigned long end_pfn, struct zone *zone);
518 
pageblock_pfn_to_page(unsigned long start_pfn, unsigned long end_pfn, struct zone *zone)519 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
520 				unsigned long end_pfn, struct zone *zone)
521 {
522 	if (zone->contiguous)
523 		return pfn_to_page(start_pfn);
524 
525 	return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
526 }
527 
528 void set_zone_contiguous(struct zone *zone);
529 
clear_zone_contiguous(struct zone *zone)530 static inline void clear_zone_contiguous(struct zone *zone)
531 {
532 	zone->contiguous = false;
533 }
534 
535 extern int __isolate_free_page(struct page *page, unsigned int order);
536 extern void __putback_isolated_page(struct page *page, unsigned int order,
537 				    int mt);
538 extern void memblock_free_pages(struct page *page, unsigned long pfn,
539 					unsigned int order);
540 extern void __free_pages_core(struct page *page, unsigned int order);
541 
542 /*
543  * This will have no effect, other than possibly generating a warning, if the
544  * caller passes in a non-large folio.
545  */
folio_set_order(struct folio *folio, unsigned int order)546 static inline void folio_set_order(struct folio *folio, unsigned int order)
547 {
548 	if (WARN_ON_ONCE(!order || !folio_test_large(folio)))
549 		return;
550 
551 	folio->_flags_1 = (folio->_flags_1 & ~0xffUL) | order;
552 #ifdef CONFIG_64BIT
553 	folio->_folio_nr_pages = 1U << order;
554 #endif
555 }
556 
557 void folio_undo_large_rmappable(struct folio *folio);
558 
prep_compound_head(struct page *page, unsigned int order)559 static inline void prep_compound_head(struct page *page, unsigned int order)
560 {
561 	struct folio *folio = (struct folio *)page;
562 
563 	folio_set_order(folio, order);
564 	atomic_set(&folio->_entire_mapcount, -1);
565 	atomic_set(&folio->_nr_pages_mapped, 0);
566 	atomic_set(&folio->_pincount, 0);
567 }
568 
prep_compound_tail(struct page *head, int tail_idx)569 static inline void prep_compound_tail(struct page *head, int tail_idx)
570 {
571 	struct page *p = head + tail_idx;
572 
573 	p->mapping = TAIL_MAPPING;
574 	set_compound_head(p, head);
575 	set_page_private(p, 0);
576 }
577 
578 extern void prep_compound_page(struct page *page, unsigned int order);
579 
580 extern void post_alloc_hook(struct page *page, unsigned int order,
581 					gfp_t gfp_flags);
582 extern int user_min_free_kbytes;
583 
584 extern void free_unref_page(struct page *page, unsigned int order);
585 extern void free_unref_page_list(struct list_head *list);
586 
587 extern void zone_pcp_reset(struct zone *zone);
588 extern void zone_pcp_disable(struct zone *zone);
589 extern void zone_pcp_enable(struct zone *zone);
590 extern void zone_pcp_init(struct zone *zone);
591 
592 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
593 			  phys_addr_t min_addr,
594 			  int nid, bool exact_nid);
595 
596 void memmap_init_range(unsigned long, int, unsigned long, unsigned long,
597 		unsigned long, enum meminit_context, struct vmem_altmap *, int);
598 
599 
600 int split_free_page(struct page *free_page,
601 			unsigned int order, unsigned long split_pfn_offset);
602 
603 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
604 
605 /*
606  * in mm/compaction.c
607  */
608 /*
609  * compact_control is used to track pages being migrated and the free pages
610  * they are being migrated to during memory compaction. The free_pfn starts
611  * at the end of a zone and migrate_pfn begins at the start. Movable pages
612  * are moved to the end of a zone during a compaction run and the run
613  * completes when free_pfn <= migrate_pfn
614  */
615 struct compact_control {
616 	struct list_head freepages;	/* List of free pages to migrate to */
617 	struct list_head migratepages;	/* List of pages being migrated */
618 	unsigned int nr_freepages;	/* Number of isolated free pages */
619 	unsigned int nr_migratepages;	/* Number of pages to migrate */
620 	unsigned long free_pfn;		/* isolate_freepages search base */
621 	/*
622 	 * Acts as an in/out parameter to page isolation for migration.
623 	 * isolate_migratepages uses it as a search base.
624 	 * isolate_migratepages_block will update the value to the next pfn
625 	 * after the last isolated one.
626 	 */
627 	unsigned long migrate_pfn;
628 	unsigned long fast_start_pfn;	/* a pfn to start linear scan from */
629 	struct zone *zone;
630 	unsigned long total_migrate_scanned;
631 	unsigned long total_free_scanned;
632 	unsigned short fast_search_fail;/* failures to use free list searches */
633 	short search_order;		/* order to start a fast search at */
634 	const gfp_t gfp_mask;		/* gfp mask of a direct compactor */
635 	int order;			/* order a direct compactor needs */
636 	int migratetype;		/* migratetype of direct compactor */
637 	const unsigned int alloc_flags;	/* alloc flags of a direct compactor */
638 	const int highest_zoneidx;	/* zone index of a direct compactor */
639 	enum migrate_mode mode;		/* Async or sync migration mode */
640 	bool ignore_skip_hint;		/* Scan blocks even if marked skip */
641 	bool no_set_skip_hint;		/* Don't mark blocks for skipping */
642 	bool ignore_block_suitable;	/* Scan blocks considered unsuitable */
643 	bool direct_compaction;		/* False from kcompactd or /proc/... */
644 	bool proactive_compaction;	/* kcompactd proactive compaction */
645 	bool whole_zone;		/* Whole zone should/has been scanned */
646 	bool contended;			/* Signal lock contention */
647 	bool finish_pageblock;		/* Scan the remainder of a pageblock. Used
648 					 * when there are potentially transient
649 					 * isolation or migration failures to
650 					 * ensure forward progress.
651 					 */
652 	bool alloc_contig;		/* alloc_contig_range allocation */
653 };
654 
655 /*
656  * Used in direct compaction when a page should be taken from the freelists
657  * immediately when one is created during the free path.
658  */
659 struct capture_control {
660 	struct compact_control *cc;
661 	struct page *page;
662 };
663 
664 unsigned long
665 isolate_freepages_range(struct compact_control *cc,
666 			unsigned long start_pfn, unsigned long end_pfn);
667 int
668 isolate_migratepages_range(struct compact_control *cc,
669 			   unsigned long low_pfn, unsigned long end_pfn);
670 
671 int __alloc_contig_migrate_range(struct compact_control *cc,
672 					unsigned long start, unsigned long end);
673 
674 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
675 void init_cma_reserved_pageblock(struct page *page);
676 
677 #endif /* CONFIG_COMPACTION || CONFIG_CMA */
678 
679 int find_suitable_fallback(struct free_area *area, unsigned int order,
680 			int migratetype, bool only_stealable, bool *can_steal);
681 
free_area_empty(struct free_area *area, int migratetype)682 static inline bool free_area_empty(struct free_area *area, int migratetype)
683 {
684 	return list_empty(&area->free_list[migratetype]);
685 }
686 
687 /*
688  * These three helpers classifies VMAs for virtual memory accounting.
689  */
690 
691 /*
692  * Executable code area - executable, not writable, not stack
693  */
is_exec_mapping(vm_flags_t flags)694 static inline bool is_exec_mapping(vm_flags_t flags)
695 {
696 	return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
697 }
698 
699 /*
700  * Stack area (including shadow stacks)
701  *
702  * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
703  * do_mmap() forbids all other combinations.
704  */
is_stack_mapping(vm_flags_t flags)705 static inline bool is_stack_mapping(vm_flags_t flags)
706 {
707 	return ((flags & VM_STACK) == VM_STACK) || (flags & VM_SHADOW_STACK);
708 }
709 
710 /*
711  * Data area - private, writable, not stack
712  */
is_data_mapping(vm_flags_t flags)713 static inline bool is_data_mapping(vm_flags_t flags)
714 {
715 	return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
716 }
717 
718 /* mm/util.c */
719 struct anon_vma *folio_anon_vma(struct folio *folio);
720 
721 #ifdef CONFIG_MMU
722 void unmap_mapping_folio(struct folio *folio);
723 extern long populate_vma_page_range(struct vm_area_struct *vma,
724 		unsigned long start, unsigned long end, int *locked);
725 extern long faultin_vma_page_range(struct vm_area_struct *vma,
726 				   unsigned long start, unsigned long end,
727 				   bool write, int *locked);
728 extern bool mlock_future_ok(struct mm_struct *mm, unsigned long flags,
729 			       unsigned long bytes);
730 /*
731  * mlock_vma_folio() and munlock_vma_folio():
732  * should be called with vma's mmap_lock held for read or write,
733  * under page table lock for the pte/pmd being added or removed.
734  *
735  * mlock is usually called at the end of page_add_*_rmap(), munlock at
736  * the end of page_remove_rmap(); but new anon folios are managed by
737  * folio_add_lru_vma() calling mlock_new_folio().
738  *
739  * @compound is used to include pmd mappings of THPs, but filter out
740  * pte mappings of THPs, which cannot be consistently counted: a pte
741  * mapping of the THP head cannot be distinguished by the page alone.
742  */
743 void mlock_folio(struct folio *folio);
mlock_vma_folio(struct folio *folio, struct vm_area_struct *vma, bool compound)744 static inline void mlock_vma_folio(struct folio *folio,
745 			struct vm_area_struct *vma, bool compound)
746 {
747 	/*
748 	 * The VM_SPECIAL check here serves two purposes.
749 	 * 1) VM_IO check prevents migration from double-counting during mlock.
750 	 * 2) Although mmap_region() and mlock_fixup() take care that VM_LOCKED
751 	 *    is never left set on a VM_SPECIAL vma, there is an interval while
752 	 *    file->f_op->mmap() is using vm_insert_page(s), when VM_LOCKED may
753 	 *    still be set while VM_SPECIAL bits are added: so ignore it then.
754 	 */
755 	if (unlikely((vma->vm_flags & (VM_LOCKED|VM_SPECIAL)) == VM_LOCKED) &&
756 	    (compound || !folio_test_large(folio)))
757 		mlock_folio(folio);
758 }
759 
760 void munlock_folio(struct folio *folio);
munlock_vma_folio(struct folio *folio, struct vm_area_struct *vma, bool compound)761 static inline void munlock_vma_folio(struct folio *folio,
762 			struct vm_area_struct *vma, bool compound)
763 {
764 	if (unlikely(vma->vm_flags & VM_LOCKED) &&
765 	    (compound || !folio_test_large(folio)))
766 		munlock_folio(folio);
767 }
768 
769 void mlock_new_folio(struct folio *folio);
770 bool need_mlock_drain(int cpu);
771 void mlock_drain_local(void);
772 void mlock_drain_remote(int cpu);
773 
774 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
775 
776 /*
777  * Return the start of user virtual address at the specific offset within
778  * a vma.
779  */
780 static inline unsigned long
vma_pgoff_address(pgoff_t pgoff, unsigned long nr_pages, struct vm_area_struct *vma)781 vma_pgoff_address(pgoff_t pgoff, unsigned long nr_pages,
782 		  struct vm_area_struct *vma)
783 {
784 	unsigned long address;
785 
786 	if (pgoff >= vma->vm_pgoff) {
787 		address = vma->vm_start +
788 			((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
789 		/* Check for address beyond vma (or wrapped through 0?) */
790 		if (address < vma->vm_start || address >= vma->vm_end)
791 			address = -EFAULT;
792 	} else if (pgoff + nr_pages - 1 >= vma->vm_pgoff) {
793 		/* Test above avoids possibility of wrap to 0 on 32-bit */
794 		address = vma->vm_start;
795 	} else {
796 		address = -EFAULT;
797 	}
798 	return address;
799 }
800 
801 /*
802  * Return the start of user virtual address of a page within a vma.
803  * Returns -EFAULT if all of the page is outside the range of vma.
804  * If page is a compound head, the entire compound page is considered.
805  */
806 static inline unsigned long
vma_address(struct page *page, struct vm_area_struct *vma)807 vma_address(struct page *page, struct vm_area_struct *vma)
808 {
809 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
810 	return vma_pgoff_address(page_to_pgoff(page), compound_nr(page), vma);
811 }
812 
813 /*
814  * Then at what user virtual address will none of the range be found in vma?
815  * Assumes that vma_address() already returned a good starting address.
816  */
vma_address_end(struct page_vma_mapped_walk *pvmw)817 static inline unsigned long vma_address_end(struct page_vma_mapped_walk *pvmw)
818 {
819 	struct vm_area_struct *vma = pvmw->vma;
820 	pgoff_t pgoff;
821 	unsigned long address;
822 
823 	/* Common case, plus ->pgoff is invalid for KSM */
824 	if (pvmw->nr_pages == 1)
825 		return pvmw->address + PAGE_SIZE;
826 
827 	pgoff = pvmw->pgoff + pvmw->nr_pages;
828 	address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
829 	/* Check for address beyond vma (or wrapped through 0?) */
830 	if (address < vma->vm_start || address > vma->vm_end)
831 		address = vma->vm_end;
832 	return address;
833 }
834 
maybe_unlock_mmap_for_io(struct vm_fault *vmf, struct file *fpin)835 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
836 						    struct file *fpin)
837 {
838 	int flags = vmf->flags;
839 
840 	if (fpin)
841 		return fpin;
842 
843 	/*
844 	 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
845 	 * anything, so we only pin the file and drop the mmap_lock if only
846 	 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
847 	 */
848 	if (fault_flag_allow_retry_first(flags) &&
849 	    !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
850 		fpin = get_file(vmf->vma->vm_file);
851 		release_fault_lock(vmf);
852 	}
853 	return fpin;
854 }
855 #else /* !CONFIG_MMU */
unmap_mapping_folio(struct folio *folio)856 static inline void unmap_mapping_folio(struct folio *folio) { }
mlock_new_folio(struct folio *folio)857 static inline void mlock_new_folio(struct folio *folio) { }
need_mlock_drain(int cpu)858 static inline bool need_mlock_drain(int cpu) { return false; }
mlock_drain_local(void)859 static inline void mlock_drain_local(void) { }
mlock_drain_remote(int cpu)860 static inline void mlock_drain_remote(int cpu) { }
vunmap_range_noflush(unsigned long start, unsigned long end)861 static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
862 {
863 }
864 #endif /* !CONFIG_MMU */
865 
866 /* Memory initialisation debug and verification */
867 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
868 DECLARE_STATIC_KEY_TRUE(deferred_pages);
869 
870 bool __init deferred_grow_zone(struct zone *zone, unsigned int order);
871 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
872 
873 enum mminit_level {
874 	MMINIT_WARNING,
875 	MMINIT_VERIFY,
876 	MMINIT_TRACE
877 };
878 
879 #ifdef CONFIG_DEBUG_MEMORY_INIT
880 
881 extern int mminit_loglevel;
882 
883 #define mminit_dprintk(level, prefix, fmt, arg...) \
884 do { \
885 	if (level < mminit_loglevel) { \
886 		if (level <= MMINIT_WARNING) \
887 			pr_warn("mminit::" prefix " " fmt, ##arg);	\
888 		else \
889 			printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
890 	} \
891 } while (0)
892 
893 extern void mminit_verify_pageflags_layout(void);
894 extern void mminit_verify_zonelist(void);
895 #else
896 
mminit_dprintk(enum mminit_level level, const char *prefix, const char *fmt, ...)897 static inline void mminit_dprintk(enum mminit_level level,
898 				const char *prefix, const char *fmt, ...)
899 {
900 }
901 
mminit_verify_pageflags_layout(void)902 static inline void mminit_verify_pageflags_layout(void)
903 {
904 }
905 
mminit_verify_zonelist(void)906 static inline void mminit_verify_zonelist(void)
907 {
908 }
909 #endif /* CONFIG_DEBUG_MEMORY_INIT */
910 
911 #define NODE_RECLAIM_NOSCAN	-2
912 #define NODE_RECLAIM_FULL	-1
913 #define NODE_RECLAIM_SOME	0
914 #define NODE_RECLAIM_SUCCESS	1
915 
916 #ifdef CONFIG_NUMA
917 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
918 extern int find_next_best_node(int node, nodemask_t *used_node_mask);
919 #else
node_reclaim(struct pglist_data *pgdat, gfp_t mask, unsigned int order)920 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
921 				unsigned int order)
922 {
923 	return NODE_RECLAIM_NOSCAN;
924 }
find_next_best_node(int node, nodemask_t *used_node_mask)925 static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
926 {
927 	return NUMA_NO_NODE;
928 }
929 #endif
930 
931 /*
932  * mm/memory-failure.c
933  */
934 extern int hwpoison_filter(struct page *p);
935 
936 extern u32 hwpoison_filter_dev_major;
937 extern u32 hwpoison_filter_dev_minor;
938 extern u64 hwpoison_filter_flags_mask;
939 extern u64 hwpoison_filter_flags_value;
940 extern u64 hwpoison_filter_memcg;
941 extern u32 hwpoison_filter_enable;
942 
943 extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
944         unsigned long, unsigned long,
945         unsigned long, unsigned long);
946 
947 extern void set_pageblock_order(void);
948 unsigned long reclaim_pages(struct list_head *folio_list);
949 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
950 					    struct list_head *folio_list);
951 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
952 #define ALLOC_WMARK_MIN		WMARK_MIN
953 #define ALLOC_WMARK_LOW		WMARK_LOW
954 #define ALLOC_WMARK_HIGH	WMARK_HIGH
955 #define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
956 
957 /* Mask to get the watermark bits */
958 #define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
959 
960 /*
961  * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
962  * cannot assume a reduced access to memory reserves is sufficient for
963  * !MMU
964  */
965 #ifdef CONFIG_MMU
966 #define ALLOC_OOM		0x08
967 #else
968 #define ALLOC_OOM		ALLOC_NO_WATERMARKS
969 #endif
970 
971 #define ALLOC_NON_BLOCK		 0x10 /* Caller cannot block. Allow access
972 				       * to 25% of the min watermark or
973 				       * 62.5% if __GFP_HIGH is set.
974 				       */
975 #define ALLOC_MIN_RESERVE	 0x20 /* __GFP_HIGH set. Allow access to 50%
976 				       * of the min watermark.
977 				       */
978 #define ALLOC_CPUSET		 0x40 /* check for correct cpuset */
979 #define ALLOC_CMA		 0x80 /* allow allocations from CMA areas */
980 #ifdef CONFIG_ZONE_DMA32
981 #define ALLOC_NOFRAGMENT	0x100 /* avoid mixing pageblock types */
982 #else
983 #define ALLOC_NOFRAGMENT	  0x0
984 #endif
985 #define ALLOC_HIGHATOMIC	0x200 /* Allows access to MIGRATE_HIGHATOMIC */
986 #define ALLOC_KSWAPD		0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
987 
988 /* Flags that allow allocations below the min watermark. */
989 #define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM)
990 
991 enum ttu_flags;
992 struct tlbflush_unmap_batch;
993 
994 
995 /*
996  * only for MM internal work items which do not depend on
997  * any allocations or locks which might depend on allocations
998  */
999 extern struct workqueue_struct *mm_percpu_wq;
1000 
1001 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
1002 void try_to_unmap_flush(void);
1003 void try_to_unmap_flush_dirty(void);
1004 void flush_tlb_batched_pending(struct mm_struct *mm);
1005 #else
try_to_unmap_flush(void)1006 static inline void try_to_unmap_flush(void)
1007 {
1008 }
try_to_unmap_flush_dirty(void)1009 static inline void try_to_unmap_flush_dirty(void)
1010 {
1011 }
flush_tlb_batched_pending(struct mm_struct *mm)1012 static inline void flush_tlb_batched_pending(struct mm_struct *mm)
1013 {
1014 }
1015 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
1016 
1017 extern const struct trace_print_flags pageflag_names[];
1018 extern const struct trace_print_flags pagetype_names[];
1019 extern const struct trace_print_flags vmaflag_names[];
1020 extern const struct trace_print_flags gfpflag_names[];
1021 
is_migrate_highatomic(enum migratetype migratetype)1022 static inline bool is_migrate_highatomic(enum migratetype migratetype)
1023 {
1024 	return migratetype == MIGRATE_HIGHATOMIC;
1025 }
1026 
is_migrate_highatomic_page(struct page *page)1027 static inline bool is_migrate_highatomic_page(struct page *page)
1028 {
1029 	return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
1030 }
1031 
1032 void setup_zone_pageset(struct zone *zone);
1033 
1034 struct migration_target_control {
1035 	int nid;		/* preferred node id */
1036 	nodemask_t *nmask;
1037 	gfp_t gfp_mask;
1038 };
1039 
1040 /*
1041  * mm/filemap.c
1042  */
1043 size_t splice_folio_into_pipe(struct pipe_inode_info *pipe,
1044 			      struct folio *folio, loff_t fpos, size_t size);
1045 
1046 /*
1047  * mm/vmalloc.c
1048  */
1049 #ifdef CONFIG_MMU
1050 void __init vmalloc_init(void);
1051 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end,
1052                 pgprot_t prot, struct page **pages, unsigned int page_shift);
1053 #else
vmalloc_init(void)1054 static inline void vmalloc_init(void)
1055 {
1056 }
1057 
1058 static inline
vmap_pages_range_noflush(unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages, unsigned int page_shift)1059 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end,
1060                 pgprot_t prot, struct page **pages, unsigned int page_shift)
1061 {
1062 	return -EINVAL;
1063 }
1064 #endif
1065 
1066 int __must_check __vmap_pages_range_noflush(unsigned long addr,
1067 			       unsigned long end, pgprot_t prot,
1068 			       struct page **pages, unsigned int page_shift);
1069 
1070 void vunmap_range_noflush(unsigned long start, unsigned long end);
1071 
1072 void __vunmap_range_noflush(unsigned long start, unsigned long end);
1073 
1074 int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
1075 		      unsigned long addr, int page_nid, int *flags);
1076 
1077 void free_zone_device_page(struct page *page);
1078 int migrate_device_coherent_page(struct page *page);
1079 
1080 /*
1081  * mm/gup.c
1082  */
1083 struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
1084 int __must_check try_grab_page(struct page *page, unsigned int flags);
1085 
1086 /*
1087  * mm/huge_memory.c
1088  */
1089 struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
1090 				   unsigned long addr, pmd_t *pmd,
1091 				   unsigned int flags);
1092 
1093 enum {
1094 	/* mark page accessed */
1095 	FOLL_TOUCH = 1 << 16,
1096 	/* a retry, previous pass started an IO */
1097 	FOLL_TRIED = 1 << 17,
1098 	/* we are working on non-current tsk/mm */
1099 	FOLL_REMOTE = 1 << 18,
1100 	/* pages must be released via unpin_user_page */
1101 	FOLL_PIN = 1 << 19,
1102 	/* gup_fast: prevent fall-back to slow gup */
1103 	FOLL_FAST_ONLY = 1 << 20,
1104 	/* allow unlocking the mmap lock */
1105 	FOLL_UNLOCKABLE = 1 << 21,
1106 };
1107 
1108 /*
1109  * Indicates for which pages that are write-protected in the page table,
1110  * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that the
1111  * GUP pin will remain consistent with the pages mapped into the page tables
1112  * of the MM.
1113  *
1114  * Temporary unmapping of PageAnonExclusive() pages or clearing of
1115  * PageAnonExclusive() has to protect against concurrent GUP:
1116  * * Ordinary GUP: Using the PT lock
1117  * * GUP-fast and fork(): mm->write_protect_seq
1118  * * GUP-fast and KSM or temporary unmapping (swap, migration): see
1119  *    page_try_share_anon_rmap()
1120  *
1121  * Must be called with the (sub)page that's actually referenced via the
1122  * page table entry, which might not necessarily be the head page for a
1123  * PTE-mapped THP.
1124  *
1125  * If the vma is NULL, we're coming from the GUP-fast path and might have
1126  * to fallback to the slow path just to lookup the vma.
1127  */
gup_must_unshare(struct vm_area_struct *vma, unsigned int flags, struct page *page)1128 static inline bool gup_must_unshare(struct vm_area_struct *vma,
1129 				    unsigned int flags, struct page *page)
1130 {
1131 	/*
1132 	 * FOLL_WRITE is implicitly handled correctly as the page table entry
1133 	 * has to be writable -- and if it references (part of) an anonymous
1134 	 * folio, that part is required to be marked exclusive.
1135 	 */
1136 	if ((flags & (FOLL_WRITE | FOLL_PIN)) != FOLL_PIN)
1137 		return false;
1138 	/*
1139 	 * Note: PageAnon(page) is stable until the page is actually getting
1140 	 * freed.
1141 	 */
1142 	if (!PageAnon(page)) {
1143 		/*
1144 		 * We only care about R/O long-term pining: R/O short-term
1145 		 * pinning does not have the semantics to observe successive
1146 		 * changes through the process page tables.
1147 		 */
1148 		if (!(flags & FOLL_LONGTERM))
1149 			return false;
1150 
1151 		/* We really need the vma ... */
1152 		if (!vma)
1153 			return true;
1154 
1155 		/*
1156 		 * ... because we only care about writable private ("COW")
1157 		 * mappings where we have to break COW early.
1158 		 */
1159 		return is_cow_mapping(vma->vm_flags);
1160 	}
1161 
1162 	/* Paired with a memory barrier in page_try_share_anon_rmap(). */
1163 	if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
1164 		smp_rmb();
1165 
1166 	/*
1167 	 * During GUP-fast we might not get called on the head page for a
1168 	 * hugetlb page that is mapped using cont-PTE, because GUP-fast does
1169 	 * not work with the abstracted hugetlb PTEs that always point at the
1170 	 * head page. For hugetlb, PageAnonExclusive only applies on the head
1171 	 * page (as it cannot be partially COW-shared), so lookup the head page.
1172 	 */
1173 	if (unlikely(!PageHead(page) && PageHuge(page)))
1174 		page = compound_head(page);
1175 
1176 	/*
1177 	 * Note that PageKsm() pages cannot be exclusive, and consequently,
1178 	 * cannot get pinned.
1179 	 */
1180 	return !PageAnonExclusive(page);
1181 }
1182 
1183 extern bool mirrored_kernelcore;
1184 extern bool memblock_has_mirror(void);
1185 
vma_soft_dirty_enabled(struct vm_area_struct *vma)1186 static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma)
1187 {
1188 	/*
1189 	 * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty
1190 	 * enablements, because when without soft-dirty being compiled in,
1191 	 * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY)
1192 	 * will be constantly true.
1193 	 */
1194 	if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
1195 		return false;
1196 
1197 	/*
1198 	 * Soft-dirty is kind of special: its tracking is enabled when the
1199 	 * vma flags not set.
1200 	 */
1201 	return !(vma->vm_flags & VM_SOFTDIRTY);
1202 }
1203 
vma_iter_config(struct vma_iterator *vmi, unsigned long index, unsigned long last)1204 static inline void vma_iter_config(struct vma_iterator *vmi,
1205 		unsigned long index, unsigned long last)
1206 {
1207 	MAS_BUG_ON(&vmi->mas, vmi->mas.node != MAS_START &&
1208 		   (vmi->mas.index > index || vmi->mas.last < index));
1209 	__mas_set_range(&vmi->mas, index, last - 1);
1210 }
1211 
1212 /*
1213  * VMA Iterator functions shared between nommu and mmap
1214  */
vma_iter_prealloc(struct vma_iterator *vmi, struct vm_area_struct *vma)1215 static inline int vma_iter_prealloc(struct vma_iterator *vmi,
1216 		struct vm_area_struct *vma)
1217 {
1218 	return mas_preallocate(&vmi->mas, vma, GFP_KERNEL);
1219 }
1220 
vma_iter_clear(struct vma_iterator *vmi)1221 static inline void vma_iter_clear(struct vma_iterator *vmi)
1222 {
1223 	mas_store_prealloc(&vmi->mas, NULL);
1224 }
1225 
vma_iter_clear_gfp(struct vma_iterator *vmi, unsigned long start, unsigned long end, gfp_t gfp)1226 static inline int vma_iter_clear_gfp(struct vma_iterator *vmi,
1227 			unsigned long start, unsigned long end, gfp_t gfp)
1228 {
1229 	__mas_set_range(&vmi->mas, start, end - 1);
1230 	mas_store_gfp(&vmi->mas, NULL, gfp);
1231 	if (unlikely(mas_is_err(&vmi->mas)))
1232 		return -ENOMEM;
1233 
1234 	return 0;
1235 }
1236 
vma_iter_load(struct vma_iterator *vmi)1237 static inline struct vm_area_struct *vma_iter_load(struct vma_iterator *vmi)
1238 {
1239 	return mas_walk(&vmi->mas);
1240 }
1241 
1242 /* Store a VMA with preallocated memory */
vma_iter_store(struct vma_iterator *vmi, struct vm_area_struct *vma)1243 static inline void vma_iter_store(struct vma_iterator *vmi,
1244 				  struct vm_area_struct *vma)
1245 {
1246 
1247 #if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
1248 	if (MAS_WARN_ON(&vmi->mas, vmi->mas.node != MAS_START &&
1249 			vmi->mas.index > vma->vm_start)) {
1250 		pr_warn("%lx > %lx\n store vma %lx-%lx\n into slot %lx-%lx\n",
1251 			vmi->mas.index, vma->vm_start, vma->vm_start,
1252 			vma->vm_end, vmi->mas.index, vmi->mas.last);
1253 	}
1254 	if (MAS_WARN_ON(&vmi->mas, vmi->mas.node != MAS_START &&
1255 			vmi->mas.last <  vma->vm_start)) {
1256 		pr_warn("%lx < %lx\nstore vma %lx-%lx\ninto slot %lx-%lx\n",
1257 		       vmi->mas.last, vma->vm_start, vma->vm_start, vma->vm_end,
1258 		       vmi->mas.index, vmi->mas.last);
1259 	}
1260 #endif
1261 
1262 	if (vmi->mas.node != MAS_START &&
1263 	    ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start)))
1264 		vma_iter_invalidate(vmi);
1265 
1266 	__mas_set_range(&vmi->mas, vma->vm_start, vma->vm_end - 1);
1267 	mas_store_prealloc(&vmi->mas, vma);
1268 }
1269 
vma_iter_store_gfp(struct vma_iterator *vmi, struct vm_area_struct *vma, gfp_t gfp)1270 static inline int vma_iter_store_gfp(struct vma_iterator *vmi,
1271 			struct vm_area_struct *vma, gfp_t gfp)
1272 {
1273 	if (vmi->mas.node != MAS_START &&
1274 	    ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start)))
1275 		vma_iter_invalidate(vmi);
1276 
1277 	__mas_set_range(&vmi->mas, vma->vm_start, vma->vm_end - 1);
1278 	mas_store_gfp(&vmi->mas, vma, gfp);
1279 	if (unlikely(mas_is_err(&vmi->mas)))
1280 		return -ENOMEM;
1281 
1282 	return 0;
1283 }
1284 
1285 /*
1286  * VMA lock generalization
1287  */
1288 struct vma_prepare {
1289 	struct vm_area_struct *vma;
1290 	struct vm_area_struct *adj_next;
1291 	struct file *file;
1292 	struct address_space *mapping;
1293 	struct anon_vma *anon_vma;
1294 	struct vm_area_struct *insert;
1295 	struct vm_area_struct *remove;
1296 	struct vm_area_struct *remove2;
1297 };
1298 #endif	/* __MM_INTERNAL_H */
1299