xref: /linux/mm/internal.h (revision 94e48d6aafef23143f92eadd010c505c49487576)
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 vm_fault_t do_swap_page(struct vm_fault *vmf);
38 
39 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
40 		unsigned long floor, unsigned long ceiling);
41 
42 static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
43 {
44 	return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP));
45 }
46 
47 void unmap_page_range(struct mmu_gather *tlb,
48 			     struct vm_area_struct *vma,
49 			     unsigned long addr, unsigned long end,
50 			     struct zap_details *details);
51 
52 void do_page_cache_ra(struct readahead_control *, unsigned long nr_to_read,
53 		unsigned long lookahead_size);
54 void force_page_cache_ra(struct readahead_control *, unsigned long nr);
55 static inline void force_page_cache_readahead(struct address_space *mapping,
56 		struct file *file, pgoff_t index, unsigned long nr_to_read)
57 {
58 	DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index);
59 	force_page_cache_ra(&ractl, nr_to_read);
60 }
61 
62 unsigned find_lock_entries(struct address_space *mapping, pgoff_t start,
63 		pgoff_t end, struct pagevec *pvec, pgoff_t *indices);
64 
65 /**
66  * page_evictable - test whether a page is evictable
67  * @page: the page to test
68  *
69  * Test whether page is evictable--i.e., should be placed on active/inactive
70  * lists vs unevictable list.
71  *
72  * Reasons page might not be evictable:
73  * (1) page's mapping marked unevictable
74  * (2) page is part of an mlocked VMA
75  *
76  */
77 static inline bool page_evictable(struct page *page)
78 {
79 	bool ret;
80 
81 	/* Prevent address_space of inode and swap cache from being freed */
82 	rcu_read_lock();
83 	ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
84 	rcu_read_unlock();
85 	return ret;
86 }
87 
88 /*
89  * Turn a non-refcounted page (->_refcount == 0) into refcounted with
90  * a count of one.
91  */
92 static inline void set_page_refcounted(struct page *page)
93 {
94 	VM_BUG_ON_PAGE(PageTail(page), page);
95 	VM_BUG_ON_PAGE(page_ref_count(page), page);
96 	set_page_count(page, 1);
97 }
98 
99 extern unsigned long highest_memmap_pfn;
100 
101 /*
102  * Maximum number of reclaim retries without progress before the OOM
103  * killer is consider the only way forward.
104  */
105 #define MAX_RECLAIM_RETRIES 16
106 
107 /*
108  * in mm/vmscan.c:
109  */
110 extern int isolate_lru_page(struct page *page);
111 extern void putback_lru_page(struct page *page);
112 
113 /*
114  * in mm/rmap.c:
115  */
116 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
117 
118 /*
119  * in mm/memcontrol.c:
120  */
121 extern bool cgroup_memory_nokmem;
122 
123 /*
124  * in mm/page_alloc.c
125  */
126 
127 /*
128  * Structure for holding the mostly immutable allocation parameters passed
129  * between functions involved in allocations, including the alloc_pages*
130  * family of functions.
131  *
132  * nodemask, migratetype and highest_zoneidx are initialized only once in
133  * __alloc_pages() and then never change.
134  *
135  * zonelist, preferred_zone and highest_zoneidx are set first in
136  * __alloc_pages() for the fast path, and might be later changed
137  * in __alloc_pages_slowpath(). All other functions pass the whole structure
138  * by a const pointer.
139  */
140 struct alloc_context {
141 	struct zonelist *zonelist;
142 	nodemask_t *nodemask;
143 	struct zoneref *preferred_zoneref;
144 	int migratetype;
145 
146 	/*
147 	 * highest_zoneidx represents highest usable zone index of
148 	 * the allocation request. Due to the nature of the zone,
149 	 * memory on lower zone than the highest_zoneidx will be
150 	 * protected by lowmem_reserve[highest_zoneidx].
151 	 *
152 	 * highest_zoneidx is also used by reclaim/compaction to limit
153 	 * the target zone since higher zone than this index cannot be
154 	 * usable for this allocation request.
155 	 */
156 	enum zone_type highest_zoneidx;
157 	bool spread_dirty_pages;
158 };
159 
160 /*
161  * Locate the struct page for both the matching buddy in our
162  * pair (buddy1) and the combined O(n+1) page they form (page).
163  *
164  * 1) Any buddy B1 will have an order O twin B2 which satisfies
165  * the following equation:
166  *     B2 = B1 ^ (1 << O)
167  * For example, if the starting buddy (buddy2) is #8 its order
168  * 1 buddy is #10:
169  *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
170  *
171  * 2) Any buddy B will have an order O+1 parent P which
172  * satisfies the following equation:
173  *     P = B & ~(1 << O)
174  *
175  * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
176  */
177 static inline unsigned long
178 __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
179 {
180 	return page_pfn ^ (1 << order);
181 }
182 
183 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
184 				unsigned long end_pfn, struct zone *zone);
185 
186 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
187 				unsigned long end_pfn, struct zone *zone)
188 {
189 	if (zone->contiguous)
190 		return pfn_to_page(start_pfn);
191 
192 	return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
193 }
194 
195 extern int __isolate_free_page(struct page *page, unsigned int order);
196 extern void __putback_isolated_page(struct page *page, unsigned int order,
197 				    int mt);
198 extern void memblock_free_pages(struct page *page, unsigned long pfn,
199 					unsigned int order);
200 extern void __free_pages_core(struct page *page, unsigned int order);
201 extern void prep_compound_page(struct page *page, unsigned int order);
202 extern void post_alloc_hook(struct page *page, unsigned int order,
203 					gfp_t gfp_flags);
204 extern int user_min_free_kbytes;
205 
206 extern void free_unref_page(struct page *page, unsigned int order);
207 extern void free_unref_page_list(struct list_head *list);
208 
209 extern void zone_pcp_update(struct zone *zone, int cpu_online);
210 extern void zone_pcp_reset(struct zone *zone);
211 extern void zone_pcp_disable(struct zone *zone);
212 extern void zone_pcp_enable(struct zone *zone);
213 
214 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
215 
216 /*
217  * in mm/compaction.c
218  */
219 /*
220  * compact_control is used to track pages being migrated and the free pages
221  * they are being migrated to during memory compaction. The free_pfn starts
222  * at the end of a zone and migrate_pfn begins at the start. Movable pages
223  * are moved to the end of a zone during a compaction run and the run
224  * completes when free_pfn <= migrate_pfn
225  */
226 struct compact_control {
227 	struct list_head freepages;	/* List of free pages to migrate to */
228 	struct list_head migratepages;	/* List of pages being migrated */
229 	unsigned int nr_freepages;	/* Number of isolated free pages */
230 	unsigned int nr_migratepages;	/* Number of pages to migrate */
231 	unsigned long free_pfn;		/* isolate_freepages search base */
232 	/*
233 	 * Acts as an in/out parameter to page isolation for migration.
234 	 * isolate_migratepages uses it as a search base.
235 	 * isolate_migratepages_block will update the value to the next pfn
236 	 * after the last isolated one.
237 	 */
238 	unsigned long migrate_pfn;
239 	unsigned long fast_start_pfn;	/* a pfn to start linear scan from */
240 	struct zone *zone;
241 	unsigned long total_migrate_scanned;
242 	unsigned long total_free_scanned;
243 	unsigned short fast_search_fail;/* failures to use free list searches */
244 	short search_order;		/* order to start a fast search at */
245 	const gfp_t gfp_mask;		/* gfp mask of a direct compactor */
246 	int order;			/* order a direct compactor needs */
247 	int migratetype;		/* migratetype of direct compactor */
248 	const unsigned int alloc_flags;	/* alloc flags of a direct compactor */
249 	const int highest_zoneidx;	/* zone index of a direct compactor */
250 	enum migrate_mode mode;		/* Async or sync migration mode */
251 	bool ignore_skip_hint;		/* Scan blocks even if marked skip */
252 	bool no_set_skip_hint;		/* Don't mark blocks for skipping */
253 	bool ignore_block_suitable;	/* Scan blocks considered unsuitable */
254 	bool direct_compaction;		/* False from kcompactd or /proc/... */
255 	bool proactive_compaction;	/* kcompactd proactive compaction */
256 	bool whole_zone;		/* Whole zone should/has been scanned */
257 	bool contended;			/* Signal lock or sched contention */
258 	bool rescan;			/* Rescanning the same pageblock */
259 	bool alloc_contig;		/* alloc_contig_range allocation */
260 };
261 
262 /*
263  * Used in direct compaction when a page should be taken from the freelists
264  * immediately when one is created during the free path.
265  */
266 struct capture_control {
267 	struct compact_control *cc;
268 	struct page *page;
269 };
270 
271 unsigned long
272 isolate_freepages_range(struct compact_control *cc,
273 			unsigned long start_pfn, unsigned long end_pfn);
274 int
275 isolate_migratepages_range(struct compact_control *cc,
276 			   unsigned long low_pfn, unsigned long end_pfn);
277 int find_suitable_fallback(struct free_area *area, unsigned int order,
278 			int migratetype, bool only_stealable, bool *can_steal);
279 
280 #endif
281 
282 /*
283  * This function returns the order of a free page in the buddy system. In
284  * general, page_zone(page)->lock must be held by the caller to prevent the
285  * page from being allocated in parallel and returning garbage as the order.
286  * If a caller does not hold page_zone(page)->lock, it must guarantee that the
287  * page cannot be allocated or merged in parallel. Alternatively, it must
288  * handle invalid values gracefully, and use buddy_order_unsafe() below.
289  */
290 static inline unsigned int buddy_order(struct page *page)
291 {
292 	/* PageBuddy() must be checked by the caller */
293 	return page_private(page);
294 }
295 
296 /*
297  * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
298  * PageBuddy() should be checked first by the caller to minimize race window,
299  * and invalid values must be handled gracefully.
300  *
301  * READ_ONCE is used so that if the caller assigns the result into a local
302  * variable and e.g. tests it for valid range before using, the compiler cannot
303  * decide to remove the variable and inline the page_private(page) multiple
304  * times, potentially observing different values in the tests and the actual
305  * use of the result.
306  */
307 #define buddy_order_unsafe(page)	READ_ONCE(page_private(page))
308 
309 /*
310  * These three helpers classifies VMAs for virtual memory accounting.
311  */
312 
313 /*
314  * Executable code area - executable, not writable, not stack
315  */
316 static inline bool is_exec_mapping(vm_flags_t flags)
317 {
318 	return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
319 }
320 
321 /*
322  * Stack area - automatically grows in one direction
323  *
324  * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
325  * do_mmap() forbids all other combinations.
326  */
327 static inline bool is_stack_mapping(vm_flags_t flags)
328 {
329 	return (flags & VM_STACK) == VM_STACK;
330 }
331 
332 /*
333  * Data area - private, writable, not stack
334  */
335 static inline bool is_data_mapping(vm_flags_t flags)
336 {
337 	return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
338 }
339 
340 /* mm/util.c */
341 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
342 		struct vm_area_struct *prev);
343 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma);
344 
345 #ifdef CONFIG_MMU
346 extern long populate_vma_page_range(struct vm_area_struct *vma,
347 		unsigned long start, unsigned long end, int *nonblocking);
348 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
349 			unsigned long start, unsigned long end);
350 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
351 {
352 	munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
353 }
354 
355 /*
356  * must be called with vma's mmap_lock held for read or write, and page locked.
357  */
358 extern void mlock_vma_page(struct page *page);
359 extern unsigned int munlock_vma_page(struct page *page);
360 
361 /*
362  * Clear the page's PageMlocked().  This can be useful in a situation where
363  * we want to unconditionally remove a page from the pagecache -- e.g.,
364  * on truncation or freeing.
365  *
366  * It is legal to call this function for any page, mlocked or not.
367  * If called for a page that is still mapped by mlocked vmas, all we do
368  * is revert to lazy LRU behaviour -- semantics are not broken.
369  */
370 extern void clear_page_mlock(struct page *page);
371 
372 /*
373  * mlock_migrate_page - called only from migrate_misplaced_transhuge_page()
374  * (because that does not go through the full procedure of migration ptes):
375  * to migrate the Mlocked page flag; update statistics.
376  */
377 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
378 {
379 	if (TestClearPageMlocked(page)) {
380 		int nr_pages = thp_nr_pages(page);
381 
382 		/* Holding pmd lock, no change in irq context: __mod is safe */
383 		__mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
384 		SetPageMlocked(newpage);
385 		__mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
386 	}
387 }
388 
389 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
390 
391 /*
392  * At what user virtual address is page expected in vma?
393  * Returns -EFAULT if all of the page is outside the range of vma.
394  * If page is a compound head, the entire compound page is considered.
395  */
396 static inline unsigned long
397 vma_address(struct page *page, struct vm_area_struct *vma)
398 {
399 	pgoff_t pgoff;
400 	unsigned long address;
401 
402 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
403 	pgoff = page_to_pgoff(page);
404 	if (pgoff >= vma->vm_pgoff) {
405 		address = vma->vm_start +
406 			((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
407 		/* Check for address beyond vma (or wrapped through 0?) */
408 		if (address < vma->vm_start || address >= vma->vm_end)
409 			address = -EFAULT;
410 	} else if (PageHead(page) &&
411 		   pgoff + compound_nr(page) - 1 >= vma->vm_pgoff) {
412 		/* Test above avoids possibility of wrap to 0 on 32-bit */
413 		address = vma->vm_start;
414 	} else {
415 		address = -EFAULT;
416 	}
417 	return address;
418 }
419 
420 /*
421  * Then at what user virtual address will none of the page be found in vma?
422  * Assumes that vma_address() already returned a good starting address.
423  * If page is a compound head, the entire compound page is considered.
424  */
425 static inline unsigned long
426 vma_address_end(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) + compound_nr(page);
433 	address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
434 	/* Check for address beyond vma (or wrapped through 0?) */
435 	if (address < vma->vm_start || address > vma->vm_end)
436 		address = vma->vm_end;
437 	return address;
438 }
439 
440 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
441 						    struct file *fpin)
442 {
443 	int flags = vmf->flags;
444 
445 	if (fpin)
446 		return fpin;
447 
448 	/*
449 	 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
450 	 * anything, so we only pin the file and drop the mmap_lock if only
451 	 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
452 	 */
453 	if (fault_flag_allow_retry_first(flags) &&
454 	    !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
455 		fpin = get_file(vmf->vma->vm_file);
456 		mmap_read_unlock(vmf->vma->vm_mm);
457 	}
458 	return fpin;
459 }
460 
461 #else /* !CONFIG_MMU */
462 static inline void clear_page_mlock(struct page *page) { }
463 static inline void mlock_vma_page(struct page *page) { }
464 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
465 static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
466 {
467 }
468 #endif /* !CONFIG_MMU */
469 
470 /*
471  * Return the mem_map entry representing the 'offset' subpage within
472  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
473  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
474  */
475 static inline struct page *mem_map_offset(struct page *base, int offset)
476 {
477 	if (unlikely(offset >= MAX_ORDER_NR_PAGES))
478 		return nth_page(base, offset);
479 	return base + offset;
480 }
481 
482 /*
483  * Iterator over all subpages within the maximally aligned gigantic
484  * page 'base'.  Handle any discontiguity in the mem_map.
485  */
486 static inline struct page *mem_map_next(struct page *iter,
487 						struct page *base, int offset)
488 {
489 	if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
490 		unsigned long pfn = page_to_pfn(base) + offset;
491 		if (!pfn_valid(pfn))
492 			return NULL;
493 		return pfn_to_page(pfn);
494 	}
495 	return iter + 1;
496 }
497 
498 /* Memory initialisation debug and verification */
499 enum mminit_level {
500 	MMINIT_WARNING,
501 	MMINIT_VERIFY,
502 	MMINIT_TRACE
503 };
504 
505 #ifdef CONFIG_DEBUG_MEMORY_INIT
506 
507 extern int mminit_loglevel;
508 
509 #define mminit_dprintk(level, prefix, fmt, arg...) \
510 do { \
511 	if (level < mminit_loglevel) { \
512 		if (level <= MMINIT_WARNING) \
513 			pr_warn("mminit::" prefix " " fmt, ##arg);	\
514 		else \
515 			printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
516 	} \
517 } while (0)
518 
519 extern void mminit_verify_pageflags_layout(void);
520 extern void mminit_verify_zonelist(void);
521 #else
522 
523 static inline void mminit_dprintk(enum mminit_level level,
524 				const char *prefix, const char *fmt, ...)
525 {
526 }
527 
528 static inline void mminit_verify_pageflags_layout(void)
529 {
530 }
531 
532 static inline void mminit_verify_zonelist(void)
533 {
534 }
535 #endif /* CONFIG_DEBUG_MEMORY_INIT */
536 
537 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
538 #if defined(CONFIG_SPARSEMEM)
539 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
540 				unsigned long *end_pfn);
541 #else
542 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
543 				unsigned long *end_pfn)
544 {
545 }
546 #endif /* CONFIG_SPARSEMEM */
547 
548 #define NODE_RECLAIM_NOSCAN	-2
549 #define NODE_RECLAIM_FULL	-1
550 #define NODE_RECLAIM_SOME	0
551 #define NODE_RECLAIM_SUCCESS	1
552 
553 #ifdef CONFIG_NUMA
554 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
555 #else
556 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
557 				unsigned int order)
558 {
559 	return NODE_RECLAIM_NOSCAN;
560 }
561 #endif
562 
563 extern int hwpoison_filter(struct page *p);
564 
565 extern u32 hwpoison_filter_dev_major;
566 extern u32 hwpoison_filter_dev_minor;
567 extern u64 hwpoison_filter_flags_mask;
568 extern u64 hwpoison_filter_flags_value;
569 extern u64 hwpoison_filter_memcg;
570 extern u32 hwpoison_filter_enable;
571 
572 extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
573         unsigned long, unsigned long,
574         unsigned long, unsigned long);
575 
576 extern void set_pageblock_order(void);
577 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
578 					    struct list_head *page_list);
579 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
580 #define ALLOC_WMARK_MIN		WMARK_MIN
581 #define ALLOC_WMARK_LOW		WMARK_LOW
582 #define ALLOC_WMARK_HIGH	WMARK_HIGH
583 #define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
584 
585 /* Mask to get the watermark bits */
586 #define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
587 
588 /*
589  * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
590  * cannot assume a reduced access to memory reserves is sufficient for
591  * !MMU
592  */
593 #ifdef CONFIG_MMU
594 #define ALLOC_OOM		0x08
595 #else
596 #define ALLOC_OOM		ALLOC_NO_WATERMARKS
597 #endif
598 
599 #define ALLOC_HARDER		 0x10 /* try to alloc harder */
600 #define ALLOC_HIGH		 0x20 /* __GFP_HIGH set */
601 #define ALLOC_CPUSET		 0x40 /* check for correct cpuset */
602 #define ALLOC_CMA		 0x80 /* allow allocations from CMA areas */
603 #ifdef CONFIG_ZONE_DMA32
604 #define ALLOC_NOFRAGMENT	0x100 /* avoid mixing pageblock types */
605 #else
606 #define ALLOC_NOFRAGMENT	  0x0
607 #endif
608 #define ALLOC_KSWAPD		0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
609 
610 enum ttu_flags;
611 struct tlbflush_unmap_batch;
612 
613 
614 /*
615  * only for MM internal work items which do not depend on
616  * any allocations or locks which might depend on allocations
617  */
618 extern struct workqueue_struct *mm_percpu_wq;
619 
620 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
621 void try_to_unmap_flush(void);
622 void try_to_unmap_flush_dirty(void);
623 void flush_tlb_batched_pending(struct mm_struct *mm);
624 #else
625 static inline void try_to_unmap_flush(void)
626 {
627 }
628 static inline void try_to_unmap_flush_dirty(void)
629 {
630 }
631 static inline void flush_tlb_batched_pending(struct mm_struct *mm)
632 {
633 }
634 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
635 
636 extern const struct trace_print_flags pageflag_names[];
637 extern const struct trace_print_flags vmaflag_names[];
638 extern const struct trace_print_flags gfpflag_names[];
639 
640 static inline bool is_migrate_highatomic(enum migratetype migratetype)
641 {
642 	return migratetype == MIGRATE_HIGHATOMIC;
643 }
644 
645 static inline bool is_migrate_highatomic_page(struct page *page)
646 {
647 	return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
648 }
649 
650 void setup_zone_pageset(struct zone *zone);
651 
652 struct migration_target_control {
653 	int nid;		/* preferred node id */
654 	nodemask_t *nmask;
655 	gfp_t gfp_mask;
656 };
657 
658 /*
659  * mm/vmalloc.c
660  */
661 #ifdef CONFIG_MMU
662 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
663                 pgprot_t prot, struct page **pages, unsigned int page_shift);
664 #else
665 static inline
666 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
667                 pgprot_t prot, struct page **pages, unsigned int page_shift)
668 {
669 	return -EINVAL;
670 }
671 #endif
672 
673 void vunmap_range_noflush(unsigned long start, unsigned long end);
674 
675 #endif	/* __MM_INTERNAL_H */
676