xref: /linux/mm/internal.h (revision c9fdc4d5487a16bd1f003fc8b66e91f88efb50e6)
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 
15 /*
16  * The set of flags that only affect watermark checking and reclaim
17  * behaviour. This is used by the MM to obey the caller constraints
18  * about IO, FS and watermark checking while ignoring placement
19  * hints such as HIGHMEM usage.
20  */
21 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
22 			__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\
23 			__GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
24 			__GFP_ATOMIC|__GFP_NOLOCKDEP)
25 
26 /* The GFP flags allowed during early boot */
27 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
28 
29 /* Control allocation cpuset and node placement constraints */
30 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
31 
32 /* Do not use these with a slab allocator */
33 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
34 
35 void page_writeback_init(void);
36 
37 static inline void *folio_raw_mapping(struct folio *folio)
38 {
39 	unsigned long mapping = (unsigned long)folio->mapping;
40 
41 	return (void *)(mapping & ~PAGE_MAPPING_FLAGS);
42 }
43 
44 void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio,
45 						int nr_throttled);
46 static inline void acct_reclaim_writeback(struct folio *folio)
47 {
48 	pg_data_t *pgdat = folio_pgdat(folio);
49 	int nr_throttled = atomic_read(&pgdat->nr_writeback_throttled);
50 
51 	if (nr_throttled)
52 		__acct_reclaim_writeback(pgdat, folio, nr_throttled);
53 }
54 
55 static inline void wake_throttle_isolated(pg_data_t *pgdat)
56 {
57 	wait_queue_head_t *wqh;
58 
59 	wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED];
60 	if (waitqueue_active(wqh))
61 		wake_up(wqh);
62 }
63 
64 vm_fault_t do_swap_page(struct vm_fault *vmf);
65 void folio_rotate_reclaimable(struct folio *folio);
66 bool __folio_end_writeback(struct folio *folio);
67 
68 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
69 		unsigned long floor, unsigned long ceiling);
70 void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);
71 
72 static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
73 {
74 	return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP));
75 }
76 
77 void unmap_page_range(struct mmu_gather *tlb,
78 			     struct vm_area_struct *vma,
79 			     unsigned long addr, unsigned long end,
80 			     struct zap_details *details);
81 
82 void do_page_cache_ra(struct readahead_control *, unsigned long nr_to_read,
83 		unsigned long lookahead_size);
84 void force_page_cache_ra(struct readahead_control *, unsigned long nr);
85 static inline void force_page_cache_readahead(struct address_space *mapping,
86 		struct file *file, pgoff_t index, unsigned long nr_to_read)
87 {
88 	DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index);
89 	force_page_cache_ra(&ractl, nr_to_read);
90 }
91 
92 unsigned find_lock_entries(struct address_space *mapping, pgoff_t start,
93 		pgoff_t end, struct pagevec *pvec, pgoff_t *indices);
94 
95 /**
96  * folio_evictable - Test whether a folio is evictable.
97  * @folio: The folio to test.
98  *
99  * Test whether @folio is evictable -- i.e., should be placed on
100  * active/inactive lists vs unevictable list.
101  *
102  * Reasons folio might not be evictable:
103  * 1. folio's mapping marked unevictable
104  * 2. One of the pages in the folio is part of an mlocked VMA
105  */
106 static inline bool folio_evictable(struct folio *folio)
107 {
108 	bool ret;
109 
110 	/* Prevent address_space of inode and swap cache from being freed */
111 	rcu_read_lock();
112 	ret = !mapping_unevictable(folio_mapping(folio)) &&
113 			!folio_test_mlocked(folio);
114 	rcu_read_unlock();
115 	return ret;
116 }
117 
118 static inline bool page_evictable(struct page *page)
119 {
120 	bool ret;
121 
122 	/* Prevent address_space of inode and swap cache from being freed */
123 	rcu_read_lock();
124 	ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
125 	rcu_read_unlock();
126 	return ret;
127 }
128 
129 /*
130  * Turn a non-refcounted page (->_refcount == 0) into refcounted with
131  * a count of one.
132  */
133 static inline void set_page_refcounted(struct page *page)
134 {
135 	VM_BUG_ON_PAGE(PageTail(page), page);
136 	VM_BUG_ON_PAGE(page_ref_count(page), page);
137 	set_page_count(page, 1);
138 }
139 
140 extern unsigned long highest_memmap_pfn;
141 
142 /*
143  * Maximum number of reclaim retries without progress before the OOM
144  * killer is consider the only way forward.
145  */
146 #define MAX_RECLAIM_RETRIES 16
147 
148 /*
149  * in mm/vmscan.c:
150  */
151 extern int isolate_lru_page(struct page *page);
152 extern void putback_lru_page(struct page *page);
153 extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason);
154 
155 /*
156  * in mm/rmap.c:
157  */
158 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
159 
160 /*
161  * in mm/page_alloc.c
162  */
163 
164 /*
165  * Structure for holding the mostly immutable allocation parameters passed
166  * between functions involved in allocations, including the alloc_pages*
167  * family of functions.
168  *
169  * nodemask, migratetype and highest_zoneidx are initialized only once in
170  * __alloc_pages() and then never change.
171  *
172  * zonelist, preferred_zone and highest_zoneidx are set first in
173  * __alloc_pages() for the fast path, and might be later changed
174  * in __alloc_pages_slowpath(). All other functions pass the whole structure
175  * by a const pointer.
176  */
177 struct alloc_context {
178 	struct zonelist *zonelist;
179 	nodemask_t *nodemask;
180 	struct zoneref *preferred_zoneref;
181 	int migratetype;
182 
183 	/*
184 	 * highest_zoneidx represents highest usable zone index of
185 	 * the allocation request. Due to the nature of the zone,
186 	 * memory on lower zone than the highest_zoneidx will be
187 	 * protected by lowmem_reserve[highest_zoneidx].
188 	 *
189 	 * highest_zoneidx is also used by reclaim/compaction to limit
190 	 * the target zone since higher zone than this index cannot be
191 	 * usable for this allocation request.
192 	 */
193 	enum zone_type highest_zoneidx;
194 	bool spread_dirty_pages;
195 };
196 
197 /*
198  * Locate the struct page for both the matching buddy in our
199  * pair (buddy1) and the combined O(n+1) page they form (page).
200  *
201  * 1) Any buddy B1 will have an order O twin B2 which satisfies
202  * the following equation:
203  *     B2 = B1 ^ (1 << O)
204  * For example, if the starting buddy (buddy2) is #8 its order
205  * 1 buddy is #10:
206  *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
207  *
208  * 2) Any buddy B will have an order O+1 parent P which
209  * satisfies the following equation:
210  *     P = B & ~(1 << O)
211  *
212  * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
213  */
214 static inline unsigned long
215 __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
216 {
217 	return page_pfn ^ (1 << order);
218 }
219 
220 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
221 				unsigned long end_pfn, struct zone *zone);
222 
223 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
224 				unsigned long end_pfn, struct zone *zone)
225 {
226 	if (zone->contiguous)
227 		return pfn_to_page(start_pfn);
228 
229 	return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
230 }
231 
232 extern int __isolate_free_page(struct page *page, unsigned int order);
233 extern void __putback_isolated_page(struct page *page, unsigned int order,
234 				    int mt);
235 extern void memblock_free_pages(struct page *page, unsigned long pfn,
236 					unsigned int order);
237 extern void __free_pages_core(struct page *page, unsigned int order);
238 extern void prep_compound_page(struct page *page, unsigned int order);
239 extern void post_alloc_hook(struct page *page, unsigned int order,
240 					gfp_t gfp_flags);
241 extern int user_min_free_kbytes;
242 
243 extern void free_unref_page(struct page *page, unsigned int order);
244 extern void free_unref_page_list(struct list_head *list);
245 
246 extern void zone_pcp_update(struct zone *zone, int cpu_online);
247 extern void zone_pcp_reset(struct zone *zone);
248 extern void zone_pcp_disable(struct zone *zone);
249 extern void zone_pcp_enable(struct zone *zone);
250 
251 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
252 			  phys_addr_t min_addr,
253 			  int nid, bool exact_nid);
254 
255 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
256 
257 /*
258  * in mm/compaction.c
259  */
260 /*
261  * compact_control is used to track pages being migrated and the free pages
262  * they are being migrated to during memory compaction. The free_pfn starts
263  * at the end of a zone and migrate_pfn begins at the start. Movable pages
264  * are moved to the end of a zone during a compaction run and the run
265  * completes when free_pfn <= migrate_pfn
266  */
267 struct compact_control {
268 	struct list_head freepages;	/* List of free pages to migrate to */
269 	struct list_head migratepages;	/* List of pages being migrated */
270 	unsigned int nr_freepages;	/* Number of isolated free pages */
271 	unsigned int nr_migratepages;	/* Number of pages to migrate */
272 	unsigned long free_pfn;		/* isolate_freepages search base */
273 	/*
274 	 * Acts as an in/out parameter to page isolation for migration.
275 	 * isolate_migratepages uses it as a search base.
276 	 * isolate_migratepages_block will update the value to the next pfn
277 	 * after the last isolated one.
278 	 */
279 	unsigned long migrate_pfn;
280 	unsigned long fast_start_pfn;	/* a pfn to start linear scan from */
281 	struct zone *zone;
282 	unsigned long total_migrate_scanned;
283 	unsigned long total_free_scanned;
284 	unsigned short fast_search_fail;/* failures to use free list searches */
285 	short search_order;		/* order to start a fast search at */
286 	const gfp_t gfp_mask;		/* gfp mask of a direct compactor */
287 	int order;			/* order a direct compactor needs */
288 	int migratetype;		/* migratetype of direct compactor */
289 	const unsigned int alloc_flags;	/* alloc flags of a direct compactor */
290 	const int highest_zoneidx;	/* zone index of a direct compactor */
291 	enum migrate_mode mode;		/* Async or sync migration mode */
292 	bool ignore_skip_hint;		/* Scan blocks even if marked skip */
293 	bool no_set_skip_hint;		/* Don't mark blocks for skipping */
294 	bool ignore_block_suitable;	/* Scan blocks considered unsuitable */
295 	bool direct_compaction;		/* False from kcompactd or /proc/... */
296 	bool proactive_compaction;	/* kcompactd proactive compaction */
297 	bool whole_zone;		/* Whole zone should/has been scanned */
298 	bool contended;			/* Signal lock or sched contention */
299 	bool rescan;			/* Rescanning the same pageblock */
300 	bool alloc_contig;		/* alloc_contig_range allocation */
301 };
302 
303 /*
304  * Used in direct compaction when a page should be taken from the freelists
305  * immediately when one is created during the free path.
306  */
307 struct capture_control {
308 	struct compact_control *cc;
309 	struct page *page;
310 };
311 
312 unsigned long
313 isolate_freepages_range(struct compact_control *cc,
314 			unsigned long start_pfn, unsigned long end_pfn);
315 int
316 isolate_migratepages_range(struct compact_control *cc,
317 			   unsigned long low_pfn, unsigned long end_pfn);
318 #endif
319 int find_suitable_fallback(struct free_area *area, unsigned int order,
320 			int migratetype, bool only_stealable, bool *can_steal);
321 
322 /*
323  * This function returns the order of a free page in the buddy system. In
324  * general, page_zone(page)->lock must be held by the caller to prevent the
325  * page from being allocated in parallel and returning garbage as the order.
326  * If a caller does not hold page_zone(page)->lock, it must guarantee that the
327  * page cannot be allocated or merged in parallel. Alternatively, it must
328  * handle invalid values gracefully, and use buddy_order_unsafe() below.
329  */
330 static inline unsigned int buddy_order(struct page *page)
331 {
332 	/* PageBuddy() must be checked by the caller */
333 	return page_private(page);
334 }
335 
336 /*
337  * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
338  * PageBuddy() should be checked first by the caller to minimize race window,
339  * and invalid values must be handled gracefully.
340  *
341  * READ_ONCE is used so that if the caller assigns the result into a local
342  * variable and e.g. tests it for valid range before using, the compiler cannot
343  * decide to remove the variable and inline the page_private(page) multiple
344  * times, potentially observing different values in the tests and the actual
345  * use of the result.
346  */
347 #define buddy_order_unsafe(page)	READ_ONCE(page_private(page))
348 
349 /*
350  * These three helpers classifies VMAs for virtual memory accounting.
351  */
352 
353 /*
354  * Executable code area - executable, not writable, not stack
355  */
356 static inline bool is_exec_mapping(vm_flags_t flags)
357 {
358 	return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
359 }
360 
361 /*
362  * Stack area - automatically grows in one direction
363  *
364  * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
365  * do_mmap() forbids all other combinations.
366  */
367 static inline bool is_stack_mapping(vm_flags_t flags)
368 {
369 	return (flags & VM_STACK) == VM_STACK;
370 }
371 
372 /*
373  * Data area - private, writable, not stack
374  */
375 static inline bool is_data_mapping(vm_flags_t flags)
376 {
377 	return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
378 }
379 
380 /* mm/util.c */
381 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
382 		struct vm_area_struct *prev);
383 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma);
384 
385 #ifdef CONFIG_MMU
386 extern long populate_vma_page_range(struct vm_area_struct *vma,
387 		unsigned long start, unsigned long end, int *locked);
388 extern long faultin_vma_page_range(struct vm_area_struct *vma,
389 				   unsigned long start, unsigned long end,
390 				   bool write, int *locked);
391 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
392 			unsigned long start, unsigned long end);
393 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
394 {
395 	munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
396 }
397 
398 /*
399  * must be called with vma's mmap_lock held for read or write, and page locked.
400  */
401 extern void mlock_vma_page(struct page *page);
402 extern unsigned int munlock_vma_page(struct page *page);
403 
404 extern int mlock_future_check(struct mm_struct *mm, unsigned long flags,
405 			      unsigned long len);
406 
407 /*
408  * Clear the page's PageMlocked().  This can be useful in a situation where
409  * we want to unconditionally remove a page from the pagecache -- e.g.,
410  * on truncation or freeing.
411  *
412  * It is legal to call this function for any page, mlocked or not.
413  * If called for a page that is still mapped by mlocked vmas, all we do
414  * is revert to lazy LRU behaviour -- semantics are not broken.
415  */
416 extern void clear_page_mlock(struct page *page);
417 
418 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
419 
420 /*
421  * At what user virtual address is page expected in vma?
422  * Returns -EFAULT if all of the page is outside the range of vma.
423  * If page is a compound head, the entire compound page is considered.
424  */
425 static inline unsigned long
426 vma_address(struct page *page, struct vm_area_struct *vma)
427 {
428 	pgoff_t pgoff;
429 	unsigned long address;
430 
431 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
432 	pgoff = page_to_pgoff(page);
433 	if (pgoff >= vma->vm_pgoff) {
434 		address = vma->vm_start +
435 			((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
436 		/* Check for address beyond vma (or wrapped through 0?) */
437 		if (address < vma->vm_start || address >= vma->vm_end)
438 			address = -EFAULT;
439 	} else if (PageHead(page) &&
440 		   pgoff + compound_nr(page) - 1 >= vma->vm_pgoff) {
441 		/* Test above avoids possibility of wrap to 0 on 32-bit */
442 		address = vma->vm_start;
443 	} else {
444 		address = -EFAULT;
445 	}
446 	return address;
447 }
448 
449 /*
450  * Then at what user virtual address will none of the page be found in vma?
451  * Assumes that vma_address() already returned a good starting address.
452  * If page is a compound head, the entire compound page is considered.
453  */
454 static inline unsigned long
455 vma_address_end(struct page *page, struct vm_area_struct *vma)
456 {
457 	pgoff_t pgoff;
458 	unsigned long address;
459 
460 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
461 	pgoff = page_to_pgoff(page) + compound_nr(page);
462 	address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
463 	/* Check for address beyond vma (or wrapped through 0?) */
464 	if (address < vma->vm_start || address > vma->vm_end)
465 		address = vma->vm_end;
466 	return address;
467 }
468 
469 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
470 						    struct file *fpin)
471 {
472 	int flags = vmf->flags;
473 
474 	if (fpin)
475 		return fpin;
476 
477 	/*
478 	 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
479 	 * anything, so we only pin the file and drop the mmap_lock if only
480 	 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
481 	 */
482 	if (fault_flag_allow_retry_first(flags) &&
483 	    !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
484 		fpin = get_file(vmf->vma->vm_file);
485 		mmap_read_unlock(vmf->vma->vm_mm);
486 	}
487 	return fpin;
488 }
489 
490 #else /* !CONFIG_MMU */
491 static inline void clear_page_mlock(struct page *page) { }
492 static inline void mlock_vma_page(struct page *page) { }
493 static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
494 {
495 }
496 #endif /* !CONFIG_MMU */
497 
498 /*
499  * Return the mem_map entry representing the 'offset' subpage within
500  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
501  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
502  */
503 static inline struct page *mem_map_offset(struct page *base, int offset)
504 {
505 	if (unlikely(offset >= MAX_ORDER_NR_PAGES))
506 		return nth_page(base, offset);
507 	return base + offset;
508 }
509 
510 /*
511  * Iterator over all subpages within the maximally aligned gigantic
512  * page 'base'.  Handle any discontiguity in the mem_map.
513  */
514 static inline struct page *mem_map_next(struct page *iter,
515 						struct page *base, int offset)
516 {
517 	if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
518 		unsigned long pfn = page_to_pfn(base) + offset;
519 		if (!pfn_valid(pfn))
520 			return NULL;
521 		return pfn_to_page(pfn);
522 	}
523 	return iter + 1;
524 }
525 
526 /* Memory initialisation debug and verification */
527 enum mminit_level {
528 	MMINIT_WARNING,
529 	MMINIT_VERIFY,
530 	MMINIT_TRACE
531 };
532 
533 #ifdef CONFIG_DEBUG_MEMORY_INIT
534 
535 extern int mminit_loglevel;
536 
537 #define mminit_dprintk(level, prefix, fmt, arg...) \
538 do { \
539 	if (level < mminit_loglevel) { \
540 		if (level <= MMINIT_WARNING) \
541 			pr_warn("mminit::" prefix " " fmt, ##arg);	\
542 		else \
543 			printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
544 	} \
545 } while (0)
546 
547 extern void mminit_verify_pageflags_layout(void);
548 extern void mminit_verify_zonelist(void);
549 #else
550 
551 static inline void mminit_dprintk(enum mminit_level level,
552 				const char *prefix, const char *fmt, ...)
553 {
554 }
555 
556 static inline void mminit_verify_pageflags_layout(void)
557 {
558 }
559 
560 static inline void mminit_verify_zonelist(void)
561 {
562 }
563 #endif /* CONFIG_DEBUG_MEMORY_INIT */
564 
565 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
566 #if defined(CONFIG_SPARSEMEM)
567 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
568 				unsigned long *end_pfn);
569 #else
570 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
571 				unsigned long *end_pfn)
572 {
573 }
574 #endif /* CONFIG_SPARSEMEM */
575 
576 #define NODE_RECLAIM_NOSCAN	-2
577 #define NODE_RECLAIM_FULL	-1
578 #define NODE_RECLAIM_SOME	0
579 #define NODE_RECLAIM_SUCCESS	1
580 
581 #ifdef CONFIG_NUMA
582 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
583 extern int find_next_best_node(int node, nodemask_t *used_node_mask);
584 #else
585 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
586 				unsigned int order)
587 {
588 	return NODE_RECLAIM_NOSCAN;
589 }
590 static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
591 {
592 	return NUMA_NO_NODE;
593 }
594 #endif
595 
596 extern int hwpoison_filter(struct page *p);
597 
598 extern u32 hwpoison_filter_dev_major;
599 extern u32 hwpoison_filter_dev_minor;
600 extern u64 hwpoison_filter_flags_mask;
601 extern u64 hwpoison_filter_flags_value;
602 extern u64 hwpoison_filter_memcg;
603 extern u32 hwpoison_filter_enable;
604 
605 extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
606         unsigned long, unsigned long,
607         unsigned long, unsigned long);
608 
609 extern void set_pageblock_order(void);
610 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
611 					    struct list_head *page_list);
612 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
613 #define ALLOC_WMARK_MIN		WMARK_MIN
614 #define ALLOC_WMARK_LOW		WMARK_LOW
615 #define ALLOC_WMARK_HIGH	WMARK_HIGH
616 #define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
617 
618 /* Mask to get the watermark bits */
619 #define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
620 
621 /*
622  * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
623  * cannot assume a reduced access to memory reserves is sufficient for
624  * !MMU
625  */
626 #ifdef CONFIG_MMU
627 #define ALLOC_OOM		0x08
628 #else
629 #define ALLOC_OOM		ALLOC_NO_WATERMARKS
630 #endif
631 
632 #define ALLOC_HARDER		 0x10 /* try to alloc harder */
633 #define ALLOC_HIGH		 0x20 /* __GFP_HIGH set */
634 #define ALLOC_CPUSET		 0x40 /* check for correct cpuset */
635 #define ALLOC_CMA		 0x80 /* allow allocations from CMA areas */
636 #ifdef CONFIG_ZONE_DMA32
637 #define ALLOC_NOFRAGMENT	0x100 /* avoid mixing pageblock types */
638 #else
639 #define ALLOC_NOFRAGMENT	  0x0
640 #endif
641 #define ALLOC_KSWAPD		0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
642 
643 enum ttu_flags;
644 struct tlbflush_unmap_batch;
645 
646 
647 /*
648  * only for MM internal work items which do not depend on
649  * any allocations or locks which might depend on allocations
650  */
651 extern struct workqueue_struct *mm_percpu_wq;
652 
653 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
654 void try_to_unmap_flush(void);
655 void try_to_unmap_flush_dirty(void);
656 void flush_tlb_batched_pending(struct mm_struct *mm);
657 #else
658 static inline void try_to_unmap_flush(void)
659 {
660 }
661 static inline void try_to_unmap_flush_dirty(void)
662 {
663 }
664 static inline void flush_tlb_batched_pending(struct mm_struct *mm)
665 {
666 }
667 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
668 
669 extern const struct trace_print_flags pageflag_names[];
670 extern const struct trace_print_flags vmaflag_names[];
671 extern const struct trace_print_flags gfpflag_names[];
672 
673 static inline bool is_migrate_highatomic(enum migratetype migratetype)
674 {
675 	return migratetype == MIGRATE_HIGHATOMIC;
676 }
677 
678 static inline bool is_migrate_highatomic_page(struct page *page)
679 {
680 	return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
681 }
682 
683 void setup_zone_pageset(struct zone *zone);
684 
685 struct migration_target_control {
686 	int nid;		/* preferred node id */
687 	nodemask_t *nmask;
688 	gfp_t gfp_mask;
689 };
690 
691 /*
692  * mm/vmalloc.c
693  */
694 #ifdef CONFIG_MMU
695 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
696                 pgprot_t prot, struct page **pages, unsigned int page_shift);
697 #else
698 static inline
699 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
700                 pgprot_t prot, struct page **pages, unsigned int page_shift)
701 {
702 	return -EINVAL;
703 }
704 #endif
705 
706 void vunmap_range_noflush(unsigned long start, unsigned long end);
707 
708 int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
709 		      unsigned long addr, int page_nid, int *flags);
710 
711 #endif	/* __MM_INTERNAL_H */
712