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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/tracepoint-defs.h>
14 #include <linux/swap.h>
15 #include <linux/rmap.h>
16 
17 /*
18  * The set of flags that only affect watermark checking and reclaim
19  * behaviour. This is used by the MM to obey the caller constraints
20  * about IO, FS and watermark checking while ignoring placement
21  * hints such as HIGHMEM usage.
22  */
23 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
24 			__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\
25 			__GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
26 			__GFP_ATOMIC)
27 
28 /* The GFP flags allowed during early boot */
29 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
30 
31 /* Control allocation cpuset and node placement constraints */
32 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
33 
34 /* Do not use these with a slab allocator */
35 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
36 
37 enum reclaim_invoker {
38 	ALL,
39 	KSWAPD,
40 	ZSWAPD,
41 	DIRECT_RECLAIM,
42 	NODE_RECLAIM,
43 	SOFT_LIMIT,
44 	RCC_RECLAIM,
45 	FILE_RECLAIM,
46 	ANON_RECLAIM
47 };
48 
49 struct scan_control {
50 	/* How many pages shrink_list() should reclaim */
51 	unsigned long nr_to_reclaim;
52 
53 	/*
54 	 * Nodemask of nodes allowed by the caller. If NULL, all nodes
55 	 * are scanned.
56 	 */
57 	nodemask_t	*nodemask;
58 
59 	/*
60 	 * The memory cgroup that hit its limit and as a result is the
61 	 * primary target of this reclaim invocation.
62 	 */
63 	struct mem_cgroup *target_mem_cgroup;
64 
65 	/*
66 	 * Scan pressure balancing between anon and file LRUs
67 	 */
68 	unsigned long	anon_cost;
69 	unsigned long	file_cost;
70 
71 	/* Can active pages be deactivated as part of reclaim? */
72 #define DEACTIVATE_ANON 1
73 #define DEACTIVATE_FILE 2
74 	unsigned int may_deactivate:2;
75 	unsigned int force_deactivate:1;
76 	unsigned int skipped_deactivate:1;
77 
78 	/* Writepage batching in laptop mode; RECLAIM_WRITE */
79 	unsigned int may_writepage:1;
80 
81 	/* Can mapped pages be reclaimed? */
82 	unsigned int may_unmap:1;
83 
84 	/* Can pages be swapped as part of reclaim? */
85 	unsigned int may_swap:1;
86 
87 	/*
88 	 * Cgroups are not reclaimed below their configured memory.low,
89 	 * unless we threaten to OOM. If any cgroups are skipped due to
90 	 * memory.low and nothing was reclaimed, go back for memory.low.
91 	 */
92 	unsigned int memcg_low_reclaim:1;
93 	unsigned int memcg_low_skipped:1;
94 
95 	unsigned int hibernation_mode:1;
96 
97 	/* One of the zones is ready for compaction */
98 	unsigned int compaction_ready:1;
99 
100 	/* There is easily reclaimable cold cache in the current node */
101 	unsigned int cache_trim_mode:1;
102 
103 	/* The file pages on the current node are dangerously low */
104 	unsigned int file_is_tiny:1;
105 
106 	/* Allocation order */
107 	s8 order;
108 
109 	/* Scan (total_size >> priority) pages at once */
110 	s8 priority;
111 
112 	/* The highest zone to isolate pages for reclaim from */
113 	s8 reclaim_idx;
114 
115 	/* This context's GFP mask */
116 	gfp_t gfp_mask;
117 
118 	/* Incremented by the number of inactive pages that were scanned */
119 	unsigned long nr_scanned;
120 
121 	/* Number of pages freed so far during a call to shrink_zones() */
122 	unsigned long nr_reclaimed;
123 
124 	struct {
125 		unsigned int dirty;
126 		unsigned int unqueued_dirty;
127 		unsigned int congested;
128 		unsigned int writeback;
129 		unsigned int immediate;
130 		unsigned int file_taken;
131 		unsigned int taken;
132 	} nr;
133 
134 	enum reclaim_invoker invoker;
135 	u32 isolate_count;
136 	unsigned long nr_scanned_anon;
137 	unsigned long nr_scanned_file;
138 	unsigned long nr_reclaimed_anon;
139 	unsigned long nr_reclaimed_file;
140 
141 	/* for recording the reclaimed slab by now */
142 	struct reclaim_state reclaim_state;
143 };
144 
145 enum scan_balance {
146 	SCAN_EQUAL,
147 	SCAN_FRACT,
148 	SCAN_ANON,
149 	SCAN_FILE,
150 };
151 
152 void page_writeback_init(void);
153 
154 vm_fault_t do_swap_page(struct vm_fault *vmf);
155 
156 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
157 		unsigned long floor, unsigned long ceiling);
158 
can_madv_lru_vma(struct vm_area_struct * vma)159 static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
160 {
161 	return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP));
162 }
163 
164 void unmap_page_range(struct mmu_gather *tlb,
165 			     struct vm_area_struct *vma,
166 			     unsigned long addr, unsigned long end,
167 			     struct zap_details *details);
168 
169 void do_page_cache_ra(struct readahead_control *, unsigned long nr_to_read,
170 		unsigned long lookahead_size);
171 void force_page_cache_ra(struct readahead_control *, struct file_ra_state *,
172 		unsigned long nr);
force_page_cache_readahead(struct address_space * mapping,struct file * file,pgoff_t index,unsigned long nr_to_read)173 static inline void force_page_cache_readahead(struct address_space *mapping,
174 		struct file *file, pgoff_t index, unsigned long nr_to_read)
175 {
176 	DEFINE_READAHEAD(ractl, file, mapping, index);
177 	force_page_cache_ra(&ractl, &file->f_ra, nr_to_read);
178 }
179 
180 struct page *find_get_entry(struct address_space *mapping, pgoff_t index);
181 struct page *find_lock_entry(struct address_space *mapping, pgoff_t index);
182 
183 /**
184  * page_evictable - test whether a page is evictable
185  * @page: the page to test
186  *
187  * Test whether page is evictable--i.e., should be placed on active/inactive
188  * lists vs unevictable list.
189  *
190  * Reasons page might not be evictable:
191  * (1) page's mapping marked unevictable
192  * (2) page is part of an mlocked VMA
193  *
194  */
page_evictable(struct page * page)195 static inline bool page_evictable(struct page *page)
196 {
197 	bool ret;
198 
199 	/* Prevent address_space of inode and swap cache from being freed */
200 	rcu_read_lock();
201 	ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
202 	rcu_read_unlock();
203 	return ret;
204 }
205 
206 /*
207  * Turn a non-refcounted page (->_refcount == 0) into refcounted with
208  * a count of one.
209  */
set_page_refcounted(struct page * page)210 static inline void set_page_refcounted(struct page *page)
211 {
212 	VM_BUG_ON_PAGE(PageTail(page), page);
213 	VM_BUG_ON_PAGE(page_ref_count(page), page);
214 	set_page_count(page, 1);
215 }
216 
217 extern unsigned long highest_memmap_pfn;
218 
219 /*
220  * Maximum number of reclaim retries without progress before the OOM
221  * killer is consider the only way forward.
222  */
223 #define MAX_RECLAIM_RETRIES 16
224 
225 /*
226  * in mm/vmscan.c:
227  */
228 extern int isolate_lru_page(struct page *page);
229 extern void putback_lru_page(struct page *page);
230 extern unsigned int shrink_page_list(struct list_head *page_list, struct pglist_data *pgdat,
231 		struct scan_control *sc, struct reclaim_stat *stat, bool ignore_references);
232 extern unsigned long isolate_lru_pages(unsigned long nr_to_scan, struct lruvec *lruvec,
233 		struct list_head *dst, unsigned long *nr_scanned, struct scan_control *sc,
234 		enum lru_list lru);
235 extern unsigned move_pages_to_lru(struct lruvec *lruvec, struct list_head *list);
236 extern void shrink_active_list(unsigned long nr_to_scan, struct lruvec *lruvec,
237 		struct scan_control *sc, enum lru_list lru);
238 extern unsigned long shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
239 		struct scan_control *sc, enum lru_list lru);
240 extern void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc);
241 
242 /*
243  * in mm/rmap.c:
244  */
245 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
246 
247 /*
248  * in mm/page_alloc.c
249  */
250 
251 /*
252  * Structure for holding the mostly immutable allocation parameters passed
253  * between functions involved in allocations, including the alloc_pages*
254  * family of functions.
255  *
256  * nodemask, migratetype and highest_zoneidx are initialized only once in
257  * __alloc_pages_nodemask() and then never change.
258  *
259  * zonelist, preferred_zone and highest_zoneidx are set first in
260  * __alloc_pages_nodemask() for the fast path, and might be later changed
261  * in __alloc_pages_slowpath(). All other functions pass the whole structure
262  * by a const pointer.
263  */
264 struct alloc_context {
265 	struct zonelist *zonelist;
266 	nodemask_t *nodemask;
267 	struct zoneref *preferred_zoneref;
268 	int migratetype;
269 
270 	/*
271 	 * highest_zoneidx represents highest usable zone index of
272 	 * the allocation request. Due to the nature of the zone,
273 	 * memory on lower zone than the highest_zoneidx will be
274 	 * protected by lowmem_reserve[highest_zoneidx].
275 	 *
276 	 * highest_zoneidx is also used by reclaim/compaction to limit
277 	 * the target zone since higher zone than this index cannot be
278 	 * usable for this allocation request.
279 	 */
280 	enum zone_type highest_zoneidx;
281 	bool spread_dirty_pages;
282 };
283 
284 /*
285  * Locate the struct page for both the matching buddy in our
286  * pair (buddy1) and the combined O(n+1) page they form (page).
287  *
288  * 1) Any buddy B1 will have an order O twin B2 which satisfies
289  * the following equation:
290  *     B2 = B1 ^ (1 << O)
291  * For example, if the starting buddy (buddy2) is #8 its order
292  * 1 buddy is #10:
293  *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
294  *
295  * 2) Any buddy B will have an order O+1 parent P which
296  * satisfies the following equation:
297  *     P = B & ~(1 << O)
298  *
299  * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
300  */
301 static inline unsigned long
__find_buddy_pfn(unsigned long page_pfn,unsigned int order)302 __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
303 {
304 	return page_pfn ^ (1 << order);
305 }
306 
307 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
308 				unsigned long end_pfn, struct zone *zone);
309 
pageblock_pfn_to_page(unsigned long start_pfn,unsigned long end_pfn,struct zone * zone)310 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
311 				unsigned long end_pfn, struct zone *zone)
312 {
313 	if (zone->contiguous)
314 		return pfn_to_page(start_pfn);
315 
316 	return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
317 }
318 
319 extern int __isolate_free_page(struct page *page, unsigned int order);
320 extern void __putback_isolated_page(struct page *page, unsigned int order,
321 				    int mt);
322 extern void memblock_free_pages(struct page *page, unsigned long pfn,
323 					unsigned int order);
324 extern void __free_pages_core(struct page *page, unsigned int order);
325 extern void prep_compound_page(struct page *page, unsigned int order);
326 extern void post_alloc_hook(struct page *page, unsigned int order,
327 					gfp_t gfp_flags);
328 extern int user_min_free_kbytes;
329 
330 extern void zone_pcp_update(struct zone *zone);
331 extern void zone_pcp_reset(struct zone *zone);
332 
333 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
334 
335 /*
336  * in mm/compaction.c
337  */
338 /*
339  * compact_control is used to track pages being migrated and the free pages
340  * they are being migrated to during memory compaction. The free_pfn starts
341  * at the end of a zone and migrate_pfn begins at the start. Movable pages
342  * are moved to the end of a zone during a compaction run and the run
343  * completes when free_pfn <= migrate_pfn
344  */
345 struct compact_control {
346 	struct list_head freepages;	/* List of free pages to migrate to */
347 	struct list_head migratepages;	/* List of pages being migrated */
348 	unsigned int nr_freepages;	/* Number of isolated free pages */
349 	unsigned int nr_migratepages;	/* Number of pages to migrate */
350 	unsigned long free_pfn;		/* isolate_freepages search base */
351 	unsigned long migrate_pfn;	/* isolate_migratepages search base */
352 	unsigned long fast_start_pfn;	/* a pfn to start linear scan from */
353 	struct zone *zone;
354 	unsigned long total_migrate_scanned;
355 	unsigned long total_free_scanned;
356 	unsigned short fast_search_fail;/* failures to use free list searches */
357 	short search_order;		/* order to start a fast search at */
358 	const gfp_t gfp_mask;		/* gfp mask of a direct compactor */
359 	int order;			/* order a direct compactor needs */
360 	int migratetype;		/* migratetype of direct compactor */
361 	const unsigned int alloc_flags;	/* alloc flags of a direct compactor */
362 	const int highest_zoneidx;	/* zone index of a direct compactor */
363 	enum migrate_mode mode;		/* Async or sync migration mode */
364 	bool ignore_skip_hint;		/* Scan blocks even if marked skip */
365 	bool no_set_skip_hint;		/* Don't mark blocks for skipping */
366 	bool ignore_block_suitable;	/* Scan blocks considered unsuitable */
367 	bool direct_compaction;		/* False from kcompactd or /proc/... */
368 	bool proactive_compaction;	/* kcompactd proactive compaction */
369 	bool whole_zone;		/* Whole zone should/has been scanned */
370 	bool contended;			/* Signal lock or sched contention */
371 	bool rescan;			/* Rescanning the same pageblock */
372 	bool alloc_contig;		/* alloc_contig_range allocation */
373 };
374 
375 /*
376  * Used in direct compaction when a page should be taken from the freelists
377  * immediately when one is created during the free path.
378  */
379 struct capture_control {
380 	struct compact_control *cc;
381 	struct page *page;
382 };
383 
384 unsigned long
385 isolate_freepages_range(struct compact_control *cc,
386 			unsigned long start_pfn, unsigned long end_pfn);
387 unsigned long
388 isolate_migratepages_range(struct compact_control *cc,
389 			   unsigned long low_pfn, unsigned long end_pfn);
390 int find_suitable_fallback(struct free_area *area, unsigned int order,
391 			int migratetype, bool only_stealable, bool *can_steal);
392 
393 #endif
394 
395 /*
396  * This function returns the order of a free page in the buddy system. In
397  * general, page_zone(page)->lock must be held by the caller to prevent the
398  * page from being allocated in parallel and returning garbage as the order.
399  * If a caller does not hold page_zone(page)->lock, it must guarantee that the
400  * page cannot be allocated or merged in parallel. Alternatively, it must
401  * handle invalid values gracefully, and use buddy_order_unsafe() below.
402  */
buddy_order(struct page * page)403 static inline unsigned int buddy_order(struct page *page)
404 {
405 	/* PageBuddy() must be checked by the caller */
406 	return page_private(page);
407 }
408 
409 /*
410  * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
411  * PageBuddy() should be checked first by the caller to minimize race window,
412  * and invalid values must be handled gracefully.
413  *
414  * READ_ONCE is used so that if the caller assigns the result into a local
415  * variable and e.g. tests it for valid range before using, the compiler cannot
416  * decide to remove the variable and inline the page_private(page) multiple
417  * times, potentially observing different values in the tests and the actual
418  * use of the result.
419  */
420 #define buddy_order_unsafe(page)	READ_ONCE(page_private(page))
421 
is_cow_mapping(vm_flags_t flags)422 static inline bool is_cow_mapping(vm_flags_t flags)
423 {
424 	return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
425 }
426 
427 /*
428  * These three helpers classifies VMAs for virtual memory accounting.
429  */
430 
431 /*
432  * Executable code area - executable, not writable, not stack
433  */
is_exec_mapping(vm_flags_t flags)434 static inline bool is_exec_mapping(vm_flags_t flags)
435 {
436 	return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
437 }
438 
439 /*
440  * Stack area - atomatically grows in one direction
441  *
442  * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
443  * do_mmap() forbids all other combinations.
444  */
is_stack_mapping(vm_flags_t flags)445 static inline bool is_stack_mapping(vm_flags_t flags)
446 {
447 	return (flags & VM_STACK) == VM_STACK;
448 }
449 
450 /*
451  * Data area - private, writable, not stack
452  */
is_data_mapping(vm_flags_t flags)453 static inline bool is_data_mapping(vm_flags_t flags)
454 {
455 	return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
456 }
457 
458 /* mm/util.c */
459 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
460 		struct vm_area_struct *prev);
461 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma);
462 
463 #ifdef CONFIG_MMU
464 extern long populate_vma_page_range(struct vm_area_struct *vma,
465 		unsigned long start, unsigned long end, int *nonblocking);
466 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
467 			unsigned long start, unsigned long end);
munlock_vma_pages_all(struct vm_area_struct * vma)468 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
469 {
470 	munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
471 }
472 
473 /*
474  * must be called with vma's mmap_lock held for read or write, and page locked.
475  */
476 extern void mlock_vma_page(struct page *page);
477 extern unsigned int munlock_vma_page(struct page *page);
478 
479 /*
480  * Clear the page's PageMlocked().  This can be useful in a situation where
481  * we want to unconditionally remove a page from the pagecache -- e.g.,
482  * on truncation or freeing.
483  *
484  * It is legal to call this function for any page, mlocked or not.
485  * If called for a page that is still mapped by mlocked vmas, all we do
486  * is revert to lazy LRU behaviour -- semantics are not broken.
487  */
488 extern void clear_page_mlock(struct page *page);
489 
490 /*
491  * mlock_migrate_page - called only from migrate_misplaced_transhuge_page()
492  * (because that does not go through the full procedure of migration ptes):
493  * to migrate the Mlocked page flag; update statistics.
494  */
mlock_migrate_page(struct page * newpage,struct page * page)495 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
496 {
497 	if (TestClearPageMlocked(page)) {
498 		int nr_pages = thp_nr_pages(page);
499 
500 		/* Holding pmd lock, no change in irq context: __mod is safe */
501 		__mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
502 		SetPageMlocked(newpage);
503 		__mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
504 	}
505 }
506 
507 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
508 
509 /*
510  * At what user virtual address is page expected in vma?
511  * Returns -EFAULT if all of the page is outside the range of vma.
512  * If page is a compound head, the entire compound page is considered.
513  */
514 static inline unsigned long
vma_address(struct page * page,struct vm_area_struct * vma)515 vma_address(struct page *page, struct vm_area_struct *vma)
516 {
517 	pgoff_t pgoff;
518 	unsigned long address;
519 
520 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
521 	pgoff = page_to_pgoff(page);
522 	if (pgoff >= vma->vm_pgoff) {
523 		address = vma->vm_start +
524 			((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
525 		/* Check for address beyond vma (or wrapped through 0?) */
526 		if (address < vma->vm_start || address >= vma->vm_end)
527 			address = -EFAULT;
528 	} else if (PageHead(page) &&
529 		   pgoff + compound_nr(page) - 1 >= vma->vm_pgoff) {
530 		/* Test above avoids possibility of wrap to 0 on 32-bit */
531 		address = vma->vm_start;
532 	} else {
533 		address = -EFAULT;
534 	}
535 	return address;
536 }
537 
538 /*
539  * Then at what user virtual address will none of the page be found in vma?
540  * Assumes that vma_address() already returned a good starting address.
541  * If page is a compound head, the entire compound page is considered.
542  */
543 static inline unsigned long
vma_address_end(struct page * page,struct vm_area_struct * vma)544 vma_address_end(struct page *page, struct vm_area_struct *vma)
545 {
546 	pgoff_t pgoff;
547 	unsigned long address;
548 
549 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
550 	pgoff = page_to_pgoff(page) + compound_nr(page);
551 	address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
552 	/* Check for address beyond vma (or wrapped through 0?) */
553 	if (address < vma->vm_start || address > vma->vm_end)
554 		address = vma->vm_end;
555 	return address;
556 }
557 
maybe_unlock_mmap_for_io(struct vm_fault * vmf,struct file * fpin)558 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
559 						    struct file *fpin)
560 {
561 	int flags = vmf->flags;
562 
563 	if (fpin)
564 		return fpin;
565 
566 	/*
567 	 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
568 	 * anything, so we only pin the file and drop the mmap_lock if only
569 	 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
570 	 */
571 	if (fault_flag_allow_retry_first(flags) &&
572 	    !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
573 		fpin = get_file(vmf->vma->vm_file);
574 		mmap_read_unlock(vmf->vma->vm_mm);
575 	}
576 	return fpin;
577 }
578 
579 #else /* !CONFIG_MMU */
clear_page_mlock(struct page * page)580 static inline void clear_page_mlock(struct page *page) { }
mlock_vma_page(struct page * page)581 static inline void mlock_vma_page(struct page *page) { }
mlock_migrate_page(struct page * new,struct page * old)582 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
583 
584 #endif /* !CONFIG_MMU */
585 
586 /*
587  * Return the mem_map entry representing the 'offset' subpage within
588  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
589  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
590  */
mem_map_offset(struct page * base,int offset)591 static inline struct page *mem_map_offset(struct page *base, int offset)
592 {
593 	if (unlikely(offset >= MAX_ORDER_NR_PAGES))
594 		return nth_page(base, offset);
595 	return base + offset;
596 }
597 
598 /*
599  * Iterator over all subpages within the maximally aligned gigantic
600  * page 'base'.  Handle any discontiguity in the mem_map.
601  */
mem_map_next(struct page * iter,struct page * base,int offset)602 static inline struct page *mem_map_next(struct page *iter,
603 						struct page *base, int offset)
604 {
605 	if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
606 		unsigned long pfn = page_to_pfn(base) + offset;
607 		if (!pfn_valid(pfn))
608 			return NULL;
609 		return pfn_to_page(pfn);
610 	}
611 	return iter + 1;
612 }
613 
614 /* Memory initialisation debug and verification */
615 enum mminit_level {
616 	MMINIT_WARNING,
617 	MMINIT_VERIFY,
618 	MMINIT_TRACE
619 };
620 
621 #ifdef CONFIG_DEBUG_MEMORY_INIT
622 
623 extern int mminit_loglevel;
624 
625 #define mminit_dprintk(level, prefix, fmt, arg...) \
626 do { \
627 	if (level < mminit_loglevel) { \
628 		if (level <= MMINIT_WARNING) \
629 			pr_warn("mminit::" prefix " " fmt, ##arg);	\
630 		else \
631 			printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
632 	} \
633 } while (0)
634 
635 extern void mminit_verify_pageflags_layout(void);
636 extern void mminit_verify_zonelist(void);
637 #else
638 
mminit_dprintk(enum mminit_level level,const char * prefix,const char * fmt,...)639 static inline void mminit_dprintk(enum mminit_level level,
640 				const char *prefix, const char *fmt, ...)
641 {
642 }
643 
mminit_verify_pageflags_layout(void)644 static inline void mminit_verify_pageflags_layout(void)
645 {
646 }
647 
mminit_verify_zonelist(void)648 static inline void mminit_verify_zonelist(void)
649 {
650 }
651 #endif /* CONFIG_DEBUG_MEMORY_INIT */
652 
653 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
654 #if defined(CONFIG_SPARSEMEM)
655 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
656 				unsigned long *end_pfn);
657 #else
mminit_validate_memmodel_limits(unsigned long * start_pfn,unsigned long * end_pfn)658 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
659 				unsigned long *end_pfn)
660 {
661 }
662 #endif /* CONFIG_SPARSEMEM */
663 
664 #define NODE_RECLAIM_NOSCAN	-2
665 #define NODE_RECLAIM_FULL	-1
666 #define NODE_RECLAIM_SOME	0
667 #define NODE_RECLAIM_SUCCESS	1
668 
669 #ifdef CONFIG_NUMA
670 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
671 #else
node_reclaim(struct pglist_data * pgdat,gfp_t mask,unsigned int order)672 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
673 				unsigned int order)
674 {
675 	return NODE_RECLAIM_NOSCAN;
676 }
677 #endif
678 
679 extern int hwpoison_filter(struct page *p);
680 
681 extern u32 hwpoison_filter_dev_major;
682 extern u32 hwpoison_filter_dev_minor;
683 extern u64 hwpoison_filter_flags_mask;
684 extern u64 hwpoison_filter_flags_value;
685 extern u64 hwpoison_filter_memcg;
686 extern u32 hwpoison_filter_enable;
687 
688 extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
689         unsigned long, unsigned long,
690         unsigned long, unsigned long);
691 
692 extern void set_pageblock_order(void);
693 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
694 					    struct list_head *page_list);
695 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
696 #define ALLOC_WMARK_MIN		WMARK_MIN
697 #define ALLOC_WMARK_LOW		WMARK_LOW
698 #define ALLOC_WMARK_HIGH	WMARK_HIGH
699 #define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
700 
701 /* Mask to get the watermark bits */
702 #define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
703 
704 /*
705  * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
706  * cannot assume a reduced access to memory reserves is sufficient for
707  * !MMU
708  */
709 #ifdef CONFIG_MMU
710 #define ALLOC_OOM		0x08
711 #else
712 #define ALLOC_OOM		ALLOC_NO_WATERMARKS
713 #endif
714 
715 #define ALLOC_HARDER		 0x10 /* try to alloc harder */
716 #define ALLOC_HIGH		 0x20 /* __GFP_HIGH set */
717 #define ALLOC_CPUSET		 0x40 /* check for correct cpuset */
718 #define ALLOC_CMA		 0x80 /* allow allocations from CMA areas */
719 #ifdef CONFIG_ZONE_DMA32
720 #define ALLOC_NOFRAGMENT	0x100 /* avoid mixing pageblock types */
721 #else
722 #define ALLOC_NOFRAGMENT	  0x0
723 #endif
724 #define ALLOC_KSWAPD		0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
725 
726 enum ttu_flags;
727 struct tlbflush_unmap_batch;
728 
729 
730 /*
731  * only for MM internal work items which do not depend on
732  * any allocations or locks which might depend on allocations
733  */
734 extern struct workqueue_struct *mm_percpu_wq;
735 
736 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
737 void try_to_unmap_flush(void);
738 void try_to_unmap_flush_dirty(void);
739 void flush_tlb_batched_pending(struct mm_struct *mm);
740 #else
try_to_unmap_flush(void)741 static inline void try_to_unmap_flush(void)
742 {
743 }
try_to_unmap_flush_dirty(void)744 static inline void try_to_unmap_flush_dirty(void)
745 {
746 }
flush_tlb_batched_pending(struct mm_struct * mm)747 static inline void flush_tlb_batched_pending(struct mm_struct *mm)
748 {
749 }
750 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
751 
752 extern const struct trace_print_flags pageflag_names[];
753 extern const struct trace_print_flags vmaflag_names[];
754 extern const struct trace_print_flags gfpflag_names[];
755 
is_migrate_highatomic(enum migratetype migratetype)756 static inline bool is_migrate_highatomic(enum migratetype migratetype)
757 {
758 	return migratetype == MIGRATE_HIGHATOMIC;
759 }
760 
is_migrate_highatomic_page(struct page * page)761 static inline bool is_migrate_highatomic_page(struct page *page)
762 {
763 	return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
764 }
765 
766 void setup_zone_pageset(struct zone *zone);
767 
768 struct migration_target_control {
769 	int nid;		/* preferred node id */
770 	nodemask_t *nmask;
771 	gfp_t gfp_mask;
772 };
773 
774 #endif	/* __MM_INTERNAL_H */
775