xref: /linux/mm/internal.h (revision 303f8e2d02002dbe331cab7813ee091aead3cd39)
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)
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 void __acct_reclaim_writeback(pg_data_t *pgdat, struct page *page,
38 						int nr_throttled);
39 static inline void acct_reclaim_writeback(struct page *page)
40 {
41 	pg_data_t *pgdat = page_pgdat(page);
42 	int nr_throttled = atomic_read(&pgdat->nr_writeback_throttled);
43 
44 	if (nr_throttled)
45 		__acct_reclaim_writeback(pgdat, page, nr_throttled);
46 }
47 
48 static inline void wake_throttle_isolated(pg_data_t *pgdat)
49 {
50 	wait_queue_head_t *wqh;
51 
52 	wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED];
53 	if (waitqueue_active(wqh))
54 		wake_up(wqh);
55 }
56 
57 vm_fault_t do_swap_page(struct vm_fault *vmf);
58 
59 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
60 		unsigned long floor, unsigned long ceiling);
61 void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);
62 
63 static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
64 {
65 	return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP));
66 }
67 
68 void unmap_page_range(struct mmu_gather *tlb,
69 			     struct vm_area_struct *vma,
70 			     unsigned long addr, unsigned long end,
71 			     struct zap_details *details);
72 
73 void do_page_cache_ra(struct readahead_control *, unsigned long nr_to_read,
74 		unsigned long lookahead_size);
75 void force_page_cache_ra(struct readahead_control *, unsigned long nr);
76 static inline void force_page_cache_readahead(struct address_space *mapping,
77 		struct file *file, pgoff_t index, unsigned long nr_to_read)
78 {
79 	DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index);
80 	force_page_cache_ra(&ractl, nr_to_read);
81 }
82 
83 unsigned find_lock_entries(struct address_space *mapping, pgoff_t start,
84 		pgoff_t end, struct pagevec *pvec, pgoff_t *indices);
85 
86 /**
87  * page_evictable - test whether a page is evictable
88  * @page: the page to test
89  *
90  * Test whether page is evictable--i.e., should be placed on active/inactive
91  * lists vs unevictable list.
92  *
93  * Reasons page might not be evictable:
94  * (1) page's mapping marked unevictable
95  * (2) page is part of an mlocked VMA
96  *
97  */
98 static inline bool page_evictable(struct page *page)
99 {
100 	bool ret;
101 
102 	/* Prevent address_space of inode and swap cache from being freed */
103 	rcu_read_lock();
104 	ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
105 	rcu_read_unlock();
106 	return ret;
107 }
108 
109 /*
110  * Turn a non-refcounted page (->_refcount == 0) into refcounted with
111  * a count of one.
112  */
113 static inline void set_page_refcounted(struct page *page)
114 {
115 	VM_BUG_ON_PAGE(PageTail(page), page);
116 	VM_BUG_ON_PAGE(page_ref_count(page), page);
117 	set_page_count(page, 1);
118 }
119 
120 extern unsigned long highest_memmap_pfn;
121 
122 /*
123  * Maximum number of reclaim retries without progress before the OOM
124  * killer is consider the only way forward.
125  */
126 #define MAX_RECLAIM_RETRIES 16
127 
128 /*
129  * in mm/vmscan.c:
130  */
131 extern int isolate_lru_page(struct page *page);
132 extern void putback_lru_page(struct page *page);
133 extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason);
134 
135 /*
136  * in mm/rmap.c:
137  */
138 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
139 
140 /*
141  * in mm/memcontrol.c:
142  */
143 extern bool cgroup_memory_nokmem;
144 
145 /*
146  * in mm/page_alloc.c
147  */
148 
149 /*
150  * Structure for holding the mostly immutable allocation parameters passed
151  * between functions involved in allocations, including the alloc_pages*
152  * family of functions.
153  *
154  * nodemask, migratetype and highest_zoneidx are initialized only once in
155  * __alloc_pages() and then never change.
156  *
157  * zonelist, preferred_zone and highest_zoneidx are set first in
158  * __alloc_pages() for the fast path, and might be later changed
159  * in __alloc_pages_slowpath(). All other functions pass the whole structure
160  * by a const pointer.
161  */
162 struct alloc_context {
163 	struct zonelist *zonelist;
164 	nodemask_t *nodemask;
165 	struct zoneref *preferred_zoneref;
166 	int migratetype;
167 
168 	/*
169 	 * highest_zoneidx represents highest usable zone index of
170 	 * the allocation request. Due to the nature of the zone,
171 	 * memory on lower zone than the highest_zoneidx will be
172 	 * protected by lowmem_reserve[highest_zoneidx].
173 	 *
174 	 * highest_zoneidx is also used by reclaim/compaction to limit
175 	 * the target zone since higher zone than this index cannot be
176 	 * usable for this allocation request.
177 	 */
178 	enum zone_type highest_zoneidx;
179 	bool spread_dirty_pages;
180 };
181 
182 /*
183  * Locate the struct page for both the matching buddy in our
184  * pair (buddy1) and the combined O(n+1) page they form (page).
185  *
186  * 1) Any buddy B1 will have an order O twin B2 which satisfies
187  * the following equation:
188  *     B2 = B1 ^ (1 << O)
189  * For example, if the starting buddy (buddy2) is #8 its order
190  * 1 buddy is #10:
191  *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
192  *
193  * 2) Any buddy B will have an order O+1 parent P which
194  * satisfies the following equation:
195  *     P = B & ~(1 << O)
196  *
197  * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
198  */
199 static inline unsigned long
200 __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
201 {
202 	return page_pfn ^ (1 << order);
203 }
204 
205 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
206 				unsigned long end_pfn, struct zone *zone);
207 
208 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
209 				unsigned long end_pfn, struct zone *zone)
210 {
211 	if (zone->contiguous)
212 		return pfn_to_page(start_pfn);
213 
214 	return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
215 }
216 
217 extern int __isolate_free_page(struct page *page, unsigned int order);
218 extern void __putback_isolated_page(struct page *page, unsigned int order,
219 				    int mt);
220 extern void memblock_free_pages(struct page *page, unsigned long pfn,
221 					unsigned int order);
222 extern void __free_pages_core(struct page *page, unsigned int order);
223 extern void prep_compound_page(struct page *page, unsigned int order);
224 extern void post_alloc_hook(struct page *page, unsigned int order,
225 					gfp_t gfp_flags);
226 extern int user_min_free_kbytes;
227 
228 extern void free_unref_page(struct page *page, unsigned int order);
229 extern void free_unref_page_list(struct list_head *list);
230 
231 extern void zone_pcp_update(struct zone *zone, int cpu_online);
232 extern void zone_pcp_reset(struct zone *zone);
233 extern void zone_pcp_disable(struct zone *zone);
234 extern void zone_pcp_enable(struct zone *zone);
235 
236 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
237 			  phys_addr_t min_addr,
238 			  int nid, bool exact_nid);
239 
240 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
241 
242 /*
243  * in mm/compaction.c
244  */
245 /*
246  * compact_control is used to track pages being migrated and the free pages
247  * they are being migrated to during memory compaction. The free_pfn starts
248  * at the end of a zone and migrate_pfn begins at the start. Movable pages
249  * are moved to the end of a zone during a compaction run and the run
250  * completes when free_pfn <= migrate_pfn
251  */
252 struct compact_control {
253 	struct list_head freepages;	/* List of free pages to migrate to */
254 	struct list_head migratepages;	/* List of pages being migrated */
255 	unsigned int nr_freepages;	/* Number of isolated free pages */
256 	unsigned int nr_migratepages;	/* Number of pages to migrate */
257 	unsigned long free_pfn;		/* isolate_freepages search base */
258 	/*
259 	 * Acts as an in/out parameter to page isolation for migration.
260 	 * isolate_migratepages uses it as a search base.
261 	 * isolate_migratepages_block will update the value to the next pfn
262 	 * after the last isolated one.
263 	 */
264 	unsigned long migrate_pfn;
265 	unsigned long fast_start_pfn;	/* a pfn to start linear scan from */
266 	struct zone *zone;
267 	unsigned long total_migrate_scanned;
268 	unsigned long total_free_scanned;
269 	unsigned short fast_search_fail;/* failures to use free list searches */
270 	short search_order;		/* order to start a fast search at */
271 	const gfp_t gfp_mask;		/* gfp mask of a direct compactor */
272 	int order;			/* order a direct compactor needs */
273 	int migratetype;		/* migratetype of direct compactor */
274 	const unsigned int alloc_flags;	/* alloc flags of a direct compactor */
275 	const int highest_zoneidx;	/* zone index of a direct compactor */
276 	enum migrate_mode mode;		/* Async or sync migration mode */
277 	bool ignore_skip_hint;		/* Scan blocks even if marked skip */
278 	bool no_set_skip_hint;		/* Don't mark blocks for skipping */
279 	bool ignore_block_suitable;	/* Scan blocks considered unsuitable */
280 	bool direct_compaction;		/* False from kcompactd or /proc/... */
281 	bool proactive_compaction;	/* kcompactd proactive compaction */
282 	bool whole_zone;		/* Whole zone should/has been scanned */
283 	bool contended;			/* Signal lock or sched contention */
284 	bool rescan;			/* Rescanning the same pageblock */
285 	bool alloc_contig;		/* alloc_contig_range allocation */
286 };
287 
288 /*
289  * Used in direct compaction when a page should be taken from the freelists
290  * immediately when one is created during the free path.
291  */
292 struct capture_control {
293 	struct compact_control *cc;
294 	struct page *page;
295 };
296 
297 unsigned long
298 isolate_freepages_range(struct compact_control *cc,
299 			unsigned long start_pfn, unsigned long end_pfn);
300 int
301 isolate_migratepages_range(struct compact_control *cc,
302 			   unsigned long low_pfn, unsigned long end_pfn);
303 #endif
304 int find_suitable_fallback(struct free_area *area, unsigned int order,
305 			int migratetype, bool only_stealable, bool *can_steal);
306 
307 /*
308  * This function returns the order of a free page in the buddy system. In
309  * general, page_zone(page)->lock must be held by the caller to prevent the
310  * page from being allocated in parallel and returning garbage as the order.
311  * If a caller does not hold page_zone(page)->lock, it must guarantee that the
312  * page cannot be allocated or merged in parallel. Alternatively, it must
313  * handle invalid values gracefully, and use buddy_order_unsafe() below.
314  */
315 static inline unsigned int buddy_order(struct page *page)
316 {
317 	/* PageBuddy() must be checked by the caller */
318 	return page_private(page);
319 }
320 
321 /*
322  * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
323  * PageBuddy() should be checked first by the caller to minimize race window,
324  * and invalid values must be handled gracefully.
325  *
326  * READ_ONCE is used so that if the caller assigns the result into a local
327  * variable and e.g. tests it for valid range before using, the compiler cannot
328  * decide to remove the variable and inline the page_private(page) multiple
329  * times, potentially observing different values in the tests and the actual
330  * use of the result.
331  */
332 #define buddy_order_unsafe(page)	READ_ONCE(page_private(page))
333 
334 /*
335  * These three helpers classifies VMAs for virtual memory accounting.
336  */
337 
338 /*
339  * Executable code area - executable, not writable, not stack
340  */
341 static inline bool is_exec_mapping(vm_flags_t flags)
342 {
343 	return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
344 }
345 
346 /*
347  * Stack area - automatically grows in one direction
348  *
349  * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
350  * do_mmap() forbids all other combinations.
351  */
352 static inline bool is_stack_mapping(vm_flags_t flags)
353 {
354 	return (flags & VM_STACK) == VM_STACK;
355 }
356 
357 /*
358  * Data area - private, writable, not stack
359  */
360 static inline bool is_data_mapping(vm_flags_t flags)
361 {
362 	return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
363 }
364 
365 /* mm/util.c */
366 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
367 		struct vm_area_struct *prev);
368 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma);
369 
370 #ifdef CONFIG_MMU
371 extern long populate_vma_page_range(struct vm_area_struct *vma,
372 		unsigned long start, unsigned long end, int *locked);
373 extern long faultin_vma_page_range(struct vm_area_struct *vma,
374 				   unsigned long start, unsigned long end,
375 				   bool write, int *locked);
376 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
377 			unsigned long start, unsigned long end);
378 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
379 {
380 	munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
381 }
382 
383 /*
384  * must be called with vma's mmap_lock held for read or write, and page locked.
385  */
386 extern void mlock_vma_page(struct page *page);
387 extern unsigned int munlock_vma_page(struct page *page);
388 
389 extern int mlock_future_check(struct mm_struct *mm, unsigned long flags,
390 			      unsigned long len);
391 
392 /*
393  * Clear the page's PageMlocked().  This can be useful in a situation where
394  * we want to unconditionally remove a page from the pagecache -- e.g.,
395  * on truncation or freeing.
396  *
397  * It is legal to call this function for any page, mlocked or not.
398  * If called for a page that is still mapped by mlocked vmas, all we do
399  * is revert to lazy LRU behaviour -- semantics are not broken.
400  */
401 extern void clear_page_mlock(struct page *page);
402 
403 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
404 
405 /*
406  * At what user virtual address is page expected in vma?
407  * Returns -EFAULT if all of the page is outside the range of vma.
408  * If page is a compound head, the entire compound page is considered.
409  */
410 static inline unsigned long
411 vma_address(struct page *page, struct vm_area_struct *vma)
412 {
413 	pgoff_t pgoff;
414 	unsigned long address;
415 
416 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
417 	pgoff = page_to_pgoff(page);
418 	if (pgoff >= vma->vm_pgoff) {
419 		address = vma->vm_start +
420 			((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
421 		/* Check for address beyond vma (or wrapped through 0?) */
422 		if (address < vma->vm_start || address >= vma->vm_end)
423 			address = -EFAULT;
424 	} else if (PageHead(page) &&
425 		   pgoff + compound_nr(page) - 1 >= vma->vm_pgoff) {
426 		/* Test above avoids possibility of wrap to 0 on 32-bit */
427 		address = vma->vm_start;
428 	} else {
429 		address = -EFAULT;
430 	}
431 	return address;
432 }
433 
434 /*
435  * Then at what user virtual address will none of the page be found in vma?
436  * Assumes that vma_address() already returned a good starting address.
437  * If page is a compound head, the entire compound page is considered.
438  */
439 static inline unsigned long
440 vma_address_end(struct page *page, struct vm_area_struct *vma)
441 {
442 	pgoff_t pgoff;
443 	unsigned long address;
444 
445 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
446 	pgoff = page_to_pgoff(page) + compound_nr(page);
447 	address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
448 	/* Check for address beyond vma (or wrapped through 0?) */
449 	if (address < vma->vm_start || address > vma->vm_end)
450 		address = vma->vm_end;
451 	return address;
452 }
453 
454 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
455 						    struct file *fpin)
456 {
457 	int flags = vmf->flags;
458 
459 	if (fpin)
460 		return fpin;
461 
462 	/*
463 	 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
464 	 * anything, so we only pin the file and drop the mmap_lock if only
465 	 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
466 	 */
467 	if (fault_flag_allow_retry_first(flags) &&
468 	    !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
469 		fpin = get_file(vmf->vma->vm_file);
470 		mmap_read_unlock(vmf->vma->vm_mm);
471 	}
472 	return fpin;
473 }
474 
475 #else /* !CONFIG_MMU */
476 static inline void clear_page_mlock(struct page *page) { }
477 static inline void mlock_vma_page(struct page *page) { }
478 static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
479 {
480 }
481 #endif /* !CONFIG_MMU */
482 
483 /*
484  * Return the mem_map entry representing the 'offset' subpage within
485  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
486  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
487  */
488 static inline struct page *mem_map_offset(struct page *base, int offset)
489 {
490 	if (unlikely(offset >= MAX_ORDER_NR_PAGES))
491 		return nth_page(base, offset);
492 	return base + offset;
493 }
494 
495 /*
496  * Iterator over all subpages within the maximally aligned gigantic
497  * page 'base'.  Handle any discontiguity in the mem_map.
498  */
499 static inline struct page *mem_map_next(struct page *iter,
500 						struct page *base, int offset)
501 {
502 	if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
503 		unsigned long pfn = page_to_pfn(base) + offset;
504 		if (!pfn_valid(pfn))
505 			return NULL;
506 		return pfn_to_page(pfn);
507 	}
508 	return iter + 1;
509 }
510 
511 /* Memory initialisation debug and verification */
512 enum mminit_level {
513 	MMINIT_WARNING,
514 	MMINIT_VERIFY,
515 	MMINIT_TRACE
516 };
517 
518 #ifdef CONFIG_DEBUG_MEMORY_INIT
519 
520 extern int mminit_loglevel;
521 
522 #define mminit_dprintk(level, prefix, fmt, arg...) \
523 do { \
524 	if (level < mminit_loglevel) { \
525 		if (level <= MMINIT_WARNING) \
526 			pr_warn("mminit::" prefix " " fmt, ##arg);	\
527 		else \
528 			printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
529 	} \
530 } while (0)
531 
532 extern void mminit_verify_pageflags_layout(void);
533 extern void mminit_verify_zonelist(void);
534 #else
535 
536 static inline void mminit_dprintk(enum mminit_level level,
537 				const char *prefix, const char *fmt, ...)
538 {
539 }
540 
541 static inline void mminit_verify_pageflags_layout(void)
542 {
543 }
544 
545 static inline void mminit_verify_zonelist(void)
546 {
547 }
548 #endif /* CONFIG_DEBUG_MEMORY_INIT */
549 
550 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
551 #if defined(CONFIG_SPARSEMEM)
552 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
553 				unsigned long *end_pfn);
554 #else
555 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
556 				unsigned long *end_pfn)
557 {
558 }
559 #endif /* CONFIG_SPARSEMEM */
560 
561 #define NODE_RECLAIM_NOSCAN	-2
562 #define NODE_RECLAIM_FULL	-1
563 #define NODE_RECLAIM_SOME	0
564 #define NODE_RECLAIM_SUCCESS	1
565 
566 #ifdef CONFIG_NUMA
567 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
568 extern int find_next_best_node(int node, nodemask_t *used_node_mask);
569 #else
570 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
571 				unsigned int order)
572 {
573 	return NODE_RECLAIM_NOSCAN;
574 }
575 static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
576 {
577 	return NUMA_NO_NODE;
578 }
579 #endif
580 
581 extern int hwpoison_filter(struct page *p);
582 
583 extern u32 hwpoison_filter_dev_major;
584 extern u32 hwpoison_filter_dev_minor;
585 extern u64 hwpoison_filter_flags_mask;
586 extern u64 hwpoison_filter_flags_value;
587 extern u64 hwpoison_filter_memcg;
588 extern u32 hwpoison_filter_enable;
589 
590 extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
591         unsigned long, unsigned long,
592         unsigned long, unsigned long);
593 
594 extern void set_pageblock_order(void);
595 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
596 					    struct list_head *page_list);
597 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
598 #define ALLOC_WMARK_MIN		WMARK_MIN
599 #define ALLOC_WMARK_LOW		WMARK_LOW
600 #define ALLOC_WMARK_HIGH	WMARK_HIGH
601 #define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
602 
603 /* Mask to get the watermark bits */
604 #define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
605 
606 /*
607  * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
608  * cannot assume a reduced access to memory reserves is sufficient for
609  * !MMU
610  */
611 #ifdef CONFIG_MMU
612 #define ALLOC_OOM		0x08
613 #else
614 #define ALLOC_OOM		ALLOC_NO_WATERMARKS
615 #endif
616 
617 #define ALLOC_HARDER		 0x10 /* try to alloc harder */
618 #define ALLOC_HIGH		 0x20 /* __GFP_HIGH set */
619 #define ALLOC_CPUSET		 0x40 /* check for correct cpuset */
620 #define ALLOC_CMA		 0x80 /* allow allocations from CMA areas */
621 #ifdef CONFIG_ZONE_DMA32
622 #define ALLOC_NOFRAGMENT	0x100 /* avoid mixing pageblock types */
623 #else
624 #define ALLOC_NOFRAGMENT	  0x0
625 #endif
626 #define ALLOC_KSWAPD		0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
627 
628 enum ttu_flags;
629 struct tlbflush_unmap_batch;
630 
631 
632 /*
633  * only for MM internal work items which do not depend on
634  * any allocations or locks which might depend on allocations
635  */
636 extern struct workqueue_struct *mm_percpu_wq;
637 
638 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
639 void try_to_unmap_flush(void);
640 void try_to_unmap_flush_dirty(void);
641 void flush_tlb_batched_pending(struct mm_struct *mm);
642 #else
643 static inline void try_to_unmap_flush(void)
644 {
645 }
646 static inline void try_to_unmap_flush_dirty(void)
647 {
648 }
649 static inline void flush_tlb_batched_pending(struct mm_struct *mm)
650 {
651 }
652 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
653 
654 extern const struct trace_print_flags pageflag_names[];
655 extern const struct trace_print_flags vmaflag_names[];
656 extern const struct trace_print_flags gfpflag_names[];
657 
658 static inline bool is_migrate_highatomic(enum migratetype migratetype)
659 {
660 	return migratetype == MIGRATE_HIGHATOMIC;
661 }
662 
663 static inline bool is_migrate_highatomic_page(struct page *page)
664 {
665 	return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
666 }
667 
668 void setup_zone_pageset(struct zone *zone);
669 
670 struct migration_target_control {
671 	int nid;		/* preferred node id */
672 	nodemask_t *nmask;
673 	gfp_t gfp_mask;
674 };
675 
676 /*
677  * mm/vmalloc.c
678  */
679 #ifdef CONFIG_MMU
680 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
681                 pgprot_t prot, struct page **pages, unsigned int page_shift);
682 #else
683 static inline
684 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
685                 pgprot_t prot, struct page **pages, unsigned int page_shift)
686 {
687 	return -EINVAL;
688 }
689 #endif
690 
691 void vunmap_range_noflush(unsigned long start, unsigned long end);
692 
693 int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
694 		      unsigned long addr, int page_nid, int *flags);
695 
696 #endif	/* __MM_INTERNAL_H */
697