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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* internal.h: mm/ internal definitions
2 *
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
Nick Piggin0f8053a2006-03-22 00:08:33 -080011#ifndef __MM_INTERNAL_H
12#define __MM_INTERNAL_H
13
Fabian Frederick29f175d2014-04-07 15:37:55 -070014#include <linux/fs.h>
Nick Piggin0f8053a2006-03-22 00:08:33 -080015#include <linux/mm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
Jan Beulich42b77722008-07-23 21:27:10 -070017void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
18 unsigned long floor, unsigned long ceiling);
19
Nick Piggin7835e982006-03-22 00:08:40 -080020static inline void set_page_count(struct page *page, int v)
Nick Piggin77a8a782006-01-06 00:10:57 -080021{
Nick Piggin7835e982006-03-22 00:08:40 -080022 atomic_set(&page->_count, v);
23}
24
Fabian Frederick29f175d2014-04-07 15:37:55 -070025extern int __do_page_cache_readahead(struct address_space *mapping,
26 struct file *filp, pgoff_t offset, unsigned long nr_to_read,
27 unsigned long lookahead_size);
28
29/*
30 * Submit IO for the read-ahead request in file_ra_state.
31 */
32static inline unsigned long ra_submit(struct file_ra_state *ra,
33 struct address_space *mapping, struct file *filp)
34{
35 return __do_page_cache_readahead(mapping, filp,
36 ra->start, ra->size, ra->async_size);
37}
38
Nick Piggin7835e982006-03-22 00:08:40 -080039/*
40 * Turn a non-refcounted page (->_count == 0) into refcounted with
41 * a count of one.
42 */
43static inline void set_page_refcounted(struct page *page)
44{
Sasha Levin309381fea2014-01-23 15:52:54 -080045 VM_BUG_ON_PAGE(PageTail(page), page);
46 VM_BUG_ON_PAGE(atomic_read(&page->_count), page);
Nick Piggin77a8a782006-01-06 00:10:57 -080047 set_page_count(page, 1);
Nick Piggin77a8a782006-01-06 00:10:57 -080048}
49
Andrea Arcangeli70b50f92011-11-02 13:36:59 -070050static inline void __get_page_tail_foll(struct page *page,
51 bool get_page_head)
52{
53 /*
54 * If we're getting a tail page, the elevated page->_count is
55 * required only in the head page and we will elevate the head
56 * page->_count and tail page->_mapcount.
57 *
58 * We elevate page_tail->_mapcount for tail pages to force
59 * page_tail->_count to be zero at all times to avoid getting
60 * false positives from get_page_unless_zero() with
61 * speculative page access (like in
62 * page_cache_get_speculative()) on tail pages.
63 */
Sasha Levin309381fea2014-01-23 15:52:54 -080064 VM_BUG_ON_PAGE(atomic_read(&page->first_page->_count) <= 0, page);
Andrea Arcangeli70b50f92011-11-02 13:36:59 -070065 if (get_page_head)
66 atomic_inc(&page->first_page->_count);
Oleg Nesterovc7288522014-01-21 15:49:02 -080067 get_huge_page_tail(page);
Andrea Arcangeli70b50f92011-11-02 13:36:59 -070068}
69
70/*
71 * This is meant to be called as the FOLL_GET operation of
72 * follow_page() and it must be called while holding the proper PT
73 * lock while the pte (or pmd_trans_huge) is still mapping the page.
74 */
75static inline void get_page_foll(struct page *page)
76{
77 if (unlikely(PageTail(page)))
78 /*
79 * This is safe only because
80 * __split_huge_page_refcount() can't run under
81 * get_page_foll() because we hold the proper PT lock.
82 */
83 __get_page_tail_foll(page, true);
84 else {
85 /*
86 * Getting a normal page or the head of a compound page
87 * requires to already have an elevated page->_count.
88 */
Sasha Levin309381fea2014-01-23 15:52:54 -080089 VM_BUG_ON_PAGE(atomic_read(&page->_count) <= 0, page);
Andrea Arcangeli70b50f92011-11-02 13:36:59 -070090 atomic_inc(&page->_count);
91 }
92}
93
Hugh Dickins03f64622009-09-21 17:03:35 -070094extern unsigned long highest_memmap_pfn;
95
Lee Schermerhorn894bc312008-10-18 20:26:39 -070096/*
97 * in mm/vmscan.c:
98 */
Nick Piggin62695a82008-10-18 20:26:09 -070099extern int isolate_lru_page(struct page *page);
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700100extern void putback_lru_page(struct page *page);
Lisa Du6e543d52013-09-11 14:22:36 -0700101extern bool zone_reclaimable(struct zone *zone);
Nick Piggin62695a82008-10-18 20:26:09 -0700102
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700103/*
Bob Liu62190492012-12-11 16:00:37 -0800104 * in mm/rmap.c:
105 */
106extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
107
108/*
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700109 * in mm/page_alloc.c
110 */
Joonsoo Kim3c605092014-11-13 15:19:21 -0800111
112/*
113 * Locate the struct page for both the matching buddy in our
114 * pair (buddy1) and the combined O(n+1) page they form (page).
115 *
116 * 1) Any buddy B1 will have an order O twin B2 which satisfies
117 * the following equation:
118 * B2 = B1 ^ (1 << O)
119 * For example, if the starting buddy (buddy2) is #8 its order
120 * 1 buddy is #10:
121 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
122 *
123 * 2) Any buddy B will have an order O+1 parent P which
124 * satisfies the following equation:
125 * P = B & ~(1 << O)
126 *
127 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
128 */
129static inline unsigned long
130__find_buddy_index(unsigned long page_idx, unsigned int order)
131{
132 return page_idx ^ (1 << order);
133}
134
135extern int __isolate_free_page(struct page *page, unsigned int order);
Yasunori Goto0c0a4a52008-04-28 02:13:34 -0700136extern void __free_pages_bootmem(struct page *page, unsigned int order);
Wu Fengguang20a03072009-06-16 15:32:22 -0700137extern void prep_compound_page(struct page *page, unsigned long order);
Wu Fengguang8d22ba12009-12-16 12:19:58 +0100138#ifdef CONFIG_MEMORY_FAILURE
139extern bool is_free_buddy_page(struct page *page);
140#endif
Han Pingtian42aa83c2014-01-23 15:53:28 -0800141extern int user_min_free_kbytes;
Wu Fengguang20a03072009-06-16 15:32:22 -0700142
Michal Nazarewiczff9543f2011-12-29 13:09:50 +0100143#if defined CONFIG_COMPACTION || defined CONFIG_CMA
144
145/*
146 * in mm/compaction.c
147 */
148/*
149 * compact_control is used to track pages being migrated and the free pages
150 * they are being migrated to during memory compaction. The free_pfn starts
151 * at the end of a zone and migrate_pfn begins at the start. Movable pages
152 * are moved to the end of a zone during a compaction run and the run
153 * completes when free_pfn <= migrate_pfn
154 */
155struct compact_control {
156 struct list_head freepages; /* List of free pages to migrate to */
157 struct list_head migratepages; /* List of pages being migrated */
158 unsigned long nr_freepages; /* Number of isolated free pages */
159 unsigned long nr_migratepages; /* Number of pages to migrate */
160 unsigned long free_pfn; /* isolate_freepages search base */
161 unsigned long migrate_pfn; /* isolate_migratepages search base */
David Rientjese0b9dae2014-06-04 16:08:28 -0700162 enum migrate_mode mode; /* Async or sync migration mode */
Mel Gormanbb13ffe2012-10-08 16:32:41 -0700163 bool ignore_skip_hint; /* Scan blocks even if marked skip */
Mel Gormanc89511a2012-10-08 16:32:45 -0700164 bool finished_update_free; /* True when the zone cached pfns are
165 * no longer being updated
166 */
167 bool finished_update_migrate;
Michal Nazarewiczff9543f2011-12-29 13:09:50 +0100168
169 int order; /* order a direct compactor needs */
David Rientjes6d7ce552014-10-09 15:27:27 -0700170 const gfp_t gfp_mask; /* gfp mask of a direct compactor */
Michal Nazarewiczff9543f2011-12-29 13:09:50 +0100171 struct zone *zone;
Vlastimil Babka1f9efde2014-10-09 15:27:14 -0700172 int contended; /* Signal need_sched() or lock
173 * contention detected during
Vlastimil Babkabe976572014-06-04 16:10:41 -0700174 * compaction
175 */
Michal Nazarewiczff9543f2011-12-29 13:09:50 +0100176};
177
178unsigned long
Mel Gormanbb13ffe2012-10-08 16:32:41 -0700179isolate_freepages_range(struct compact_control *cc,
180 unsigned long start_pfn, unsigned long end_pfn);
Michal Nazarewiczff9543f2011-12-29 13:09:50 +0100181unsigned long
Vlastimil Babkaedc2ca62014-10-09 15:27:09 -0700182isolate_migratepages_range(struct compact_control *cc,
183 unsigned long low_pfn, unsigned long end_pfn);
Michal Nazarewiczff9543f2011-12-29 13:09:50 +0100184
185#endif
Nick Piggin0f8053a2006-03-22 00:08:33 -0800186
Mel Gorman48f13bf2007-10-16 01:26:10 -0700187/*
Mel Gorman6c144662014-01-23 15:53:38 -0800188 * This function returns the order of a free page in the buddy system. In
189 * general, page_zone(page)->lock must be held by the caller to prevent the
190 * page from being allocated in parallel and returning garbage as the order.
191 * If a caller does not hold page_zone(page)->lock, it must guarantee that the
Vlastimil Babka99c0fd52014-10-09 15:27:23 -0700192 * page cannot be allocated or merged in parallel. Alternatively, it must
193 * handle invalid values gracefully, and use page_order_unsafe() below.
Mel Gorman48f13bf2007-10-16 01:26:10 -0700194 */
195static inline unsigned long page_order(struct page *page)
196{
KAMEZAWA Hiroyuki572438f2010-10-26 14:22:08 -0700197 /* PageBuddy() must be checked by the caller */
Mel Gorman48f13bf2007-10-16 01:26:10 -0700198 return page_private(page);
199}
Alexander van Heukelumb5a0e012008-02-23 15:24:06 -0800200
Vlastimil Babka99c0fd52014-10-09 15:27:23 -0700201/*
202 * Like page_order(), but for callers who cannot afford to hold the zone lock.
203 * PageBuddy() should be checked first by the caller to minimize race window,
204 * and invalid values must be handled gracefully.
205 *
206 * ACCESS_ONCE is used so that if the caller assigns the result into a local
207 * variable and e.g. tests it for valid range before using, the compiler cannot
208 * decide to remove the variable and inline the page_private(page) multiple
209 * times, potentially observing different values in the tests and the actual
210 * use of the result.
211 */
212#define page_order_unsafe(page) ACCESS_ONCE(page_private(page))
213
Kirill A. Shutemov4bbd4c72014-06-04 16:08:10 -0700214static inline bool is_cow_mapping(vm_flags_t flags)
215{
216 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
217}
218
Namhyung Kim6038def2011-05-24 17:11:22 -0700219/* mm/util.c */
220void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
221 struct vm_area_struct *prev, struct rb_node *rb_parent);
222
Hugh Dickinsaf8e3352009-12-14 17:58:59 -0800223#ifdef CONFIG_MMU
Michel Lespinassecea10a12013-02-22 16:32:44 -0800224extern long __mlock_vma_pages_range(struct vm_area_struct *vma,
225 unsigned long start, unsigned long end, int *nonblocking);
Hugh Dickinsaf8e3352009-12-14 17:58:59 -0800226extern void munlock_vma_pages_range(struct vm_area_struct *vma,
227 unsigned long start, unsigned long end);
228static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
229{
230 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
231}
232
Nick Pigginb291f002008-10-18 20:26:44 -0700233/*
Hugh Dickins73848b42009-12-14 17:59:22 -0800234 * must be called with vma's mmap_sem held for read or write, and page locked.
Nick Pigginb291f002008-10-18 20:26:44 -0700235 */
236extern void mlock_vma_page(struct page *page);
Michel Lespinasseff6a6da2013-02-27 17:02:44 -0800237extern unsigned int munlock_vma_page(struct page *page);
Nick Pigginb291f002008-10-18 20:26:44 -0700238
239/*
240 * Clear the page's PageMlocked(). This can be useful in a situation where
241 * we want to unconditionally remove a page from the pagecache -- e.g.,
242 * on truncation or freeing.
243 *
244 * It is legal to call this function for any page, mlocked or not.
245 * If called for a page that is still mapped by mlocked vmas, all we do
246 * is revert to lazy LRU behaviour -- semantics are not broken.
247 */
Hugh Dickinse6c509f2012-10-08 16:33:19 -0700248extern void clear_page_mlock(struct page *page);
Nick Pigginb291f002008-10-18 20:26:44 -0700249
250/*
251 * mlock_migrate_page - called only from migrate_page_copy() to
Nick Piggin5344b7e2008-10-18 20:26:51 -0700252 * migrate the Mlocked page flag; update statistics.
Nick Pigginb291f002008-10-18 20:26:44 -0700253 */
254static inline void mlock_migrate_page(struct page *newpage, struct page *page)
255{
Nick Piggin5344b7e2008-10-18 20:26:51 -0700256 if (TestClearPageMlocked(page)) {
257 unsigned long flags;
Mel Gormanb32967f2012-11-19 12:35:47 +0000258 int nr_pages = hpage_nr_pages(page);
Nick Piggin5344b7e2008-10-18 20:26:51 -0700259
260 local_irq_save(flags);
Mel Gormanb32967f2012-11-19 12:35:47 +0000261 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
Nick Pigginb291f002008-10-18 20:26:44 -0700262 SetPageMlocked(newpage);
Mel Gormanb32967f2012-11-19 12:35:47 +0000263 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
Nick Piggin5344b7e2008-10-18 20:26:51 -0700264 local_irq_restore(flags);
265 }
Nick Pigginb291f002008-10-18 20:26:44 -0700266}
267
Mel Gormanb32967f2012-11-19 12:35:47 +0000268extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
269
Andrea Arcangeli71e3aac2011-01-13 15:46:52 -0800270#ifdef CONFIG_TRANSPARENT_HUGEPAGE
271extern unsigned long vma_address(struct page *page,
272 struct vm_area_struct *vma);
273#endif
Hugh Dickinsaf8e3352009-12-14 17:58:59 -0800274#else /* !CONFIG_MMU */
Nick Pigginb291f002008-10-18 20:26:44 -0700275static inline void clear_page_mlock(struct page *page) { }
276static inline void mlock_vma_page(struct page *page) { }
277static inline void mlock_migrate_page(struct page *new, struct page *old) { }
278
Hugh Dickinsaf8e3352009-12-14 17:58:59 -0800279#endif /* !CONFIG_MMU */
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700280
Alexander van Heukelumb5a0e012008-02-23 15:24:06 -0800281/*
Andy Whitcroft69d177c2008-11-06 12:53:26 -0800282 * Return the mem_map entry representing the 'offset' subpage within
283 * the maximally aligned gigantic page 'base'. Handle any discontiguity
284 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
285 */
286static inline struct page *mem_map_offset(struct page *base, int offset)
287{
288 if (unlikely(offset >= MAX_ORDER_NR_PAGES))
Fabian Frederickbc7f84c2014-08-06 16:05:17 -0700289 return nth_page(base, offset);
Andy Whitcroft69d177c2008-11-06 12:53:26 -0800290 return base + offset;
291}
292
293/*
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300294 * Iterator over all subpages within the maximally aligned gigantic
Andy Whitcroft69d177c2008-11-06 12:53:26 -0800295 * page 'base'. Handle any discontiguity in the mem_map.
296 */
297static inline struct page *mem_map_next(struct page *iter,
298 struct page *base, int offset)
299{
300 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
301 unsigned long pfn = page_to_pfn(base) + offset;
302 if (!pfn_valid(pfn))
303 return NULL;
304 return pfn_to_page(pfn);
305 }
306 return iter + 1;
307}
308
309/*
Alexander van Heukelumb5a0e012008-02-23 15:24:06 -0800310 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
311 * so all functions starting at paging_init should be marked __init
312 * in those cases. SPARSEMEM, however, allows for memory hotplug,
313 * and alloc_bootmem_node is not used.
314 */
315#ifdef CONFIG_SPARSEMEM
316#define __paginginit __meminit
317#else
318#define __paginginit __init
319#endif
320
Mel Gorman6b74ab92008-07-23 21:26:49 -0700321/* Memory initialisation debug and verification */
322enum mminit_level {
323 MMINIT_WARNING,
324 MMINIT_VERIFY,
325 MMINIT_TRACE
326};
327
328#ifdef CONFIG_DEBUG_MEMORY_INIT
329
330extern int mminit_loglevel;
331
332#define mminit_dprintk(level, prefix, fmt, arg...) \
333do { \
334 if (level < mminit_loglevel) { \
335 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
336 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
337 } \
338} while (0)
339
Mel Gorman708614e2008-07-23 21:26:51 -0700340extern void mminit_verify_pageflags_layout(void);
341extern void mminit_verify_page_links(struct page *page,
342 enum zone_type zone, unsigned long nid, unsigned long pfn);
Mel Gorman68ad8df2008-07-23 21:26:52 -0700343extern void mminit_verify_zonelist(void);
Mel Gorman708614e2008-07-23 21:26:51 -0700344
Mel Gorman6b74ab92008-07-23 21:26:49 -0700345#else
346
347static inline void mminit_dprintk(enum mminit_level level,
348 const char *prefix, const char *fmt, ...)
349{
350}
351
Mel Gorman708614e2008-07-23 21:26:51 -0700352static inline void mminit_verify_pageflags_layout(void)
353{
354}
355
356static inline void mminit_verify_page_links(struct page *page,
357 enum zone_type zone, unsigned long nid, unsigned long pfn)
358{
359}
Mel Gorman68ad8df2008-07-23 21:26:52 -0700360
361static inline void mminit_verify_zonelist(void)
362{
363}
Mel Gorman6b74ab92008-07-23 21:26:49 -0700364#endif /* CONFIG_DEBUG_MEMORY_INIT */
Mel Gorman2dbb51c2008-07-23 21:26:52 -0700365
366/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
367#if defined(CONFIG_SPARSEMEM)
368extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
369 unsigned long *end_pfn);
370#else
371static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
372 unsigned long *end_pfn)
373{
374}
375#endif /* CONFIG_SPARSEMEM */
376
Mel Gormanfa5e0842009-06-16 15:33:22 -0700377#define ZONE_RECLAIM_NOSCAN -2
378#define ZONE_RECLAIM_FULL -1
379#define ZONE_RECLAIM_SOME 0
380#define ZONE_RECLAIM_SUCCESS 1
Wu Fengguang7c116f22009-12-16 12:19:59 +0100381
Wu Fengguang31d3d342009-12-16 12:19:59 +0100382extern int hwpoison_filter(struct page *p);
383
Wu Fengguang7c116f22009-12-16 12:19:59 +0100384extern u32 hwpoison_filter_dev_major;
385extern u32 hwpoison_filter_dev_minor;
Wu Fengguang478c5ff2009-12-16 12:19:59 +0100386extern u64 hwpoison_filter_flags_mask;
387extern u64 hwpoison_filter_flags_value;
Andi Kleen4fd466e2009-12-16 12:19:59 +0100388extern u64 hwpoison_filter_memcg;
Haicheng Li1bfe5fe2009-12-16 12:19:59 +0100389extern u32 hwpoison_filter_enable;
Al Viroeb36c582012-05-30 20:17:35 -0400390
391extern unsigned long vm_mmap_pgoff(struct file *, unsigned long,
392 unsigned long, unsigned long,
393 unsigned long, unsigned long);
Xishi Qiuca57df72012-07-31 16:43:19 -0700394
395extern void set_pageblock_order(void);
Minchan Kim02c6de82012-10-08 16:31:55 -0700396unsigned long reclaim_clean_pages_from_list(struct zone *zone,
397 struct list_head *page_list);
Bartlomiej Zolnierkiewiczd95ea5d2012-10-08 16:32:05 -0700398/* The ALLOC_WMARK bits are used as an index to zone->watermark */
399#define ALLOC_WMARK_MIN WMARK_MIN
400#define ALLOC_WMARK_LOW WMARK_LOW
401#define ALLOC_WMARK_HIGH WMARK_HIGH
402#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
403
404/* Mask to get the watermark bits */
405#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
406
407#define ALLOC_HARDER 0x10 /* try to alloc harder */
408#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
409#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
410#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
Johannes Weiner3a025762014-04-07 15:37:48 -0700411#define ALLOC_FAIR 0x100 /* fair zone allocation */
Bartlomiej Zolnierkiewiczd95ea5d2012-10-08 16:32:05 -0700412
Michel Lespinassedb971412012-10-08 16:29:34 -0700413#endif /* __MM_INTERNAL_H */