xref: /linux/mm/internal.h (revision 4c62e9764ab403d42f9b8871b1241fe7812f19d4)
1 /* 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  */
11 #ifndef __MM_INTERNAL_H
12 #define __MM_INTERNAL_H
13 
14 #include <linux/mm.h>
15 
16 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
17 		unsigned long floor, unsigned long ceiling);
18 
19 static inline void set_page_count(struct page *page, int v)
20 {
21 	atomic_set(&page->_count, v);
22 }
23 
24 /*
25  * Turn a non-refcounted page (->_count == 0) into refcounted with
26  * a count of one.
27  */
28 static inline void set_page_refcounted(struct page *page)
29 {
30 	VM_BUG_ON(PageTail(page));
31 	VM_BUG_ON(atomic_read(&page->_count));
32 	set_page_count(page, 1);
33 }
34 
35 static inline void __put_page(struct page *page)
36 {
37 	atomic_dec(&page->_count);
38 }
39 
40 static inline void __get_page_tail_foll(struct page *page,
41 					bool get_page_head)
42 {
43 	/*
44 	 * If we're getting a tail page, the elevated page->_count is
45 	 * required only in the head page and we will elevate the head
46 	 * page->_count and tail page->_mapcount.
47 	 *
48 	 * We elevate page_tail->_mapcount for tail pages to force
49 	 * page_tail->_count to be zero at all times to avoid getting
50 	 * false positives from get_page_unless_zero() with
51 	 * speculative page access (like in
52 	 * page_cache_get_speculative()) on tail pages.
53 	 */
54 	VM_BUG_ON(atomic_read(&page->first_page->_count) <= 0);
55 	VM_BUG_ON(atomic_read(&page->_count) != 0);
56 	VM_BUG_ON(page_mapcount(page) < 0);
57 	if (get_page_head)
58 		atomic_inc(&page->first_page->_count);
59 	atomic_inc(&page->_mapcount);
60 }
61 
62 /*
63  * This is meant to be called as the FOLL_GET operation of
64  * follow_page() and it must be called while holding the proper PT
65  * lock while the pte (or pmd_trans_huge) is still mapping the page.
66  */
67 static inline void get_page_foll(struct page *page)
68 {
69 	if (unlikely(PageTail(page)))
70 		/*
71 		 * This is safe only because
72 		 * __split_huge_page_refcount() can't run under
73 		 * get_page_foll() because we hold the proper PT lock.
74 		 */
75 		__get_page_tail_foll(page, true);
76 	else {
77 		/*
78 		 * Getting a normal page or the head of a compound page
79 		 * requires to already have an elevated page->_count.
80 		 */
81 		VM_BUG_ON(atomic_read(&page->_count) <= 0);
82 		atomic_inc(&page->_count);
83 	}
84 }
85 
86 extern unsigned long highest_memmap_pfn;
87 
88 /*
89  * in mm/vmscan.c:
90  */
91 extern int isolate_lru_page(struct page *page);
92 extern void putback_lru_page(struct page *page);
93 
94 /*
95  * in mm/rmap.c:
96  */
97 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
98 
99 /*
100  * in mm/page_alloc.c
101  */
102 extern void __free_pages_bootmem(struct page *page, unsigned int order);
103 extern void prep_compound_page(struct page *page, unsigned long order);
104 #ifdef CONFIG_MEMORY_FAILURE
105 extern bool is_free_buddy_page(struct page *page);
106 #endif
107 
108 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
109 
110 /*
111  * in mm/compaction.c
112  */
113 /*
114  * compact_control is used to track pages being migrated and the free pages
115  * they are being migrated to during memory compaction. The free_pfn starts
116  * at the end of a zone and migrate_pfn begins at the start. Movable pages
117  * are moved to the end of a zone during a compaction run and the run
118  * completes when free_pfn <= migrate_pfn
119  */
120 struct compact_control {
121 	struct list_head freepages;	/* List of free pages to migrate to */
122 	struct list_head migratepages;	/* List of pages being migrated */
123 	unsigned long nr_freepages;	/* Number of isolated free pages */
124 	unsigned long nr_migratepages;	/* Number of pages to migrate */
125 	unsigned long free_pfn;		/* isolate_freepages search base */
126 	unsigned long migrate_pfn;	/* isolate_migratepages search base */
127 	bool sync;			/* Synchronous migration */
128 	bool ignore_skip_hint;		/* Scan blocks even if marked skip */
129 	bool finished_update_free;	/* True when the zone cached pfns are
130 					 * no longer being updated
131 					 */
132 	bool finished_update_migrate;
133 
134 	int order;			/* order a direct compactor needs */
135 	int migratetype;		/* MOVABLE, RECLAIMABLE etc */
136 	struct zone *zone;
137 	bool contended;			/* True if a lock was contended */
138 	struct page **page;		/* Page captured of requested size */
139 };
140 
141 unsigned long
142 isolate_freepages_range(struct compact_control *cc,
143 			unsigned long start_pfn, unsigned long end_pfn);
144 unsigned long
145 isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
146 	unsigned long low_pfn, unsigned long end_pfn, bool unevictable);
147 
148 #endif
149 
150 /*
151  * function for dealing with page's order in buddy system.
152  * zone->lock is already acquired when we use these.
153  * So, we don't need atomic page->flags operations here.
154  */
155 static inline unsigned long page_order(struct page *page)
156 {
157 	/* PageBuddy() must be checked by the caller */
158 	return page_private(page);
159 }
160 
161 /* mm/util.c */
162 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
163 		struct vm_area_struct *prev, struct rb_node *rb_parent);
164 
165 #ifdef CONFIG_MMU
166 extern long mlock_vma_pages_range(struct vm_area_struct *vma,
167 			unsigned long start, unsigned long end);
168 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
169 			unsigned long start, unsigned long end);
170 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
171 {
172 	munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
173 }
174 
175 /*
176  * Called only in fault path, to determine if a new page is being
177  * mapped into a LOCKED vma.  If it is, mark page as mlocked.
178  */
179 static inline int mlocked_vma_newpage(struct vm_area_struct *vma,
180 				    struct page *page)
181 {
182 	VM_BUG_ON(PageLRU(page));
183 
184 	if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
185 		return 0;
186 
187 	if (!TestSetPageMlocked(page)) {
188 		mod_zone_page_state(page_zone(page), NR_MLOCK,
189 				    hpage_nr_pages(page));
190 		count_vm_event(UNEVICTABLE_PGMLOCKED);
191 	}
192 	return 1;
193 }
194 
195 /*
196  * must be called with vma's mmap_sem held for read or write, and page locked.
197  */
198 extern void mlock_vma_page(struct page *page);
199 extern void munlock_vma_page(struct page *page);
200 
201 /*
202  * Clear the page's PageMlocked().  This can be useful in a situation where
203  * we want to unconditionally remove a page from the pagecache -- e.g.,
204  * on truncation or freeing.
205  *
206  * It is legal to call this function for any page, mlocked or not.
207  * If called for a page that is still mapped by mlocked vmas, all we do
208  * is revert to lazy LRU behaviour -- semantics are not broken.
209  */
210 extern void clear_page_mlock(struct page *page);
211 
212 /*
213  * mlock_migrate_page - called only from migrate_page_copy() to
214  * migrate the Mlocked page flag; update statistics.
215  */
216 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
217 {
218 	if (TestClearPageMlocked(page)) {
219 		unsigned long flags;
220 		int nr_pages = hpage_nr_pages(page);
221 
222 		local_irq_save(flags);
223 		__mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
224 		SetPageMlocked(newpage);
225 		__mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
226 		local_irq_restore(flags);
227 	}
228 }
229 
230 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
231 
232 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
233 extern unsigned long vma_address(struct page *page,
234 				 struct vm_area_struct *vma);
235 #endif
236 #else /* !CONFIG_MMU */
237 static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p)
238 {
239 	return 0;
240 }
241 static inline void clear_page_mlock(struct page *page) { }
242 static inline void mlock_vma_page(struct page *page) { }
243 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
244 
245 #endif /* !CONFIG_MMU */
246 
247 /*
248  * Return the mem_map entry representing the 'offset' subpage within
249  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
250  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
251  */
252 static inline struct page *mem_map_offset(struct page *base, int offset)
253 {
254 	if (unlikely(offset >= MAX_ORDER_NR_PAGES))
255 		return pfn_to_page(page_to_pfn(base) + offset);
256 	return base + offset;
257 }
258 
259 /*
260  * Iterator over all subpages within the maximally aligned gigantic
261  * page 'base'.  Handle any discontiguity in the mem_map.
262  */
263 static inline struct page *mem_map_next(struct page *iter,
264 						struct page *base, int offset)
265 {
266 	if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
267 		unsigned long pfn = page_to_pfn(base) + offset;
268 		if (!pfn_valid(pfn))
269 			return NULL;
270 		return pfn_to_page(pfn);
271 	}
272 	return iter + 1;
273 }
274 
275 /*
276  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
277  * so all functions starting at paging_init should be marked __init
278  * in those cases. SPARSEMEM, however, allows for memory hotplug,
279  * and alloc_bootmem_node is not used.
280  */
281 #ifdef CONFIG_SPARSEMEM
282 #define __paginginit __meminit
283 #else
284 #define __paginginit __init
285 #endif
286 
287 /* Memory initialisation debug and verification */
288 enum mminit_level {
289 	MMINIT_WARNING,
290 	MMINIT_VERIFY,
291 	MMINIT_TRACE
292 };
293 
294 #ifdef CONFIG_DEBUG_MEMORY_INIT
295 
296 extern int mminit_loglevel;
297 
298 #define mminit_dprintk(level, prefix, fmt, arg...) \
299 do { \
300 	if (level < mminit_loglevel) { \
301 		printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
302 		printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
303 	} \
304 } while (0)
305 
306 extern void mminit_verify_pageflags_layout(void);
307 extern void mminit_verify_page_links(struct page *page,
308 		enum zone_type zone, unsigned long nid, unsigned long pfn);
309 extern void mminit_verify_zonelist(void);
310 
311 #else
312 
313 static inline void mminit_dprintk(enum mminit_level level,
314 				const char *prefix, const char *fmt, ...)
315 {
316 }
317 
318 static inline void mminit_verify_pageflags_layout(void)
319 {
320 }
321 
322 static inline void mminit_verify_page_links(struct page *page,
323 		enum zone_type zone, unsigned long nid, unsigned long pfn)
324 {
325 }
326 
327 static inline void mminit_verify_zonelist(void)
328 {
329 }
330 #endif /* CONFIG_DEBUG_MEMORY_INIT */
331 
332 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
333 #if defined(CONFIG_SPARSEMEM)
334 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
335 				unsigned long *end_pfn);
336 #else
337 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
338 				unsigned long *end_pfn)
339 {
340 }
341 #endif /* CONFIG_SPARSEMEM */
342 
343 #define ZONE_RECLAIM_NOSCAN	-2
344 #define ZONE_RECLAIM_FULL	-1
345 #define ZONE_RECLAIM_SOME	0
346 #define ZONE_RECLAIM_SUCCESS	1
347 
348 extern int hwpoison_filter(struct page *p);
349 
350 extern u32 hwpoison_filter_dev_major;
351 extern u32 hwpoison_filter_dev_minor;
352 extern u64 hwpoison_filter_flags_mask;
353 extern u64 hwpoison_filter_flags_value;
354 extern u64 hwpoison_filter_memcg;
355 extern u32 hwpoison_filter_enable;
356 
357 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long,
358         unsigned long, unsigned long,
359         unsigned long, unsigned long);
360 
361 extern void set_pageblock_order(void);
362 unsigned long reclaim_clean_pages_from_list(struct zone *zone,
363 					    struct list_head *page_list);
364 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
365 #define ALLOC_WMARK_MIN		WMARK_MIN
366 #define ALLOC_WMARK_LOW		WMARK_LOW
367 #define ALLOC_WMARK_HIGH	WMARK_HIGH
368 #define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
369 
370 /* Mask to get the watermark bits */
371 #define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
372 
373 #define ALLOC_HARDER		0x10 /* try to alloc harder */
374 #define ALLOC_HIGH		0x20 /* __GFP_HIGH set */
375 #define ALLOC_CPUSET		0x40 /* check for correct cpuset */
376 #define ALLOC_CMA		0x80 /* allow allocations from CMA areas */
377 
378 #endif	/* __MM_INTERNAL_H */
379