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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/fs.h>
15 #include <linux/mm.h>
16 #include <linux/pagemap.h>
17 #include <linux/tracepoint-defs.h>
18
19 /*
20 * The set of flags that only affect watermark checking and reclaim
21 * behaviour. This is used by the MM to obey the caller constraints
22 * about IO, FS and watermark checking while ignoring placement
23 * hints such as HIGHMEM usage.
24 */
25 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
26 __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
27 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC)
28
29 /* The GFP flags allowed during early boot */
30 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
31
32 /* Control allocation cpuset and node placement constraints */
33 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
34
35 /* Do not use these with a slab allocator */
36 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
37
38 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
39 unsigned long floor, unsigned long ceiling);
40
41 void unmap_page_range(struct mmu_gather *tlb,
42 struct vm_area_struct *vma,
43 unsigned long addr, unsigned long end,
44 struct zap_details *details);
45
46 extern int __do_page_cache_readahead(struct address_space *mapping,
47 struct file *filp, pgoff_t offset, unsigned long nr_to_read,
48 unsigned long lookahead_size);
49
50 /*
51 * Submit IO for the read-ahead request in file_ra_state.
52 */
53 static inline unsigned long ra_submit(struct file_ra_state *ra,
54 struct address_space *mapping, struct file *filp)
55 {
56 return __do_page_cache_readahead(mapping, filp,
57 ra->start, ra->size, ra->async_size);
58 }
59
60 /*
61 * Turn a non-refcounted page (->_refcount == 0) into refcounted with
62 * a count of one.
63 */
64 static inline void set_page_refcounted(struct page *page)
65 {
66 VM_BUG_ON_PAGE(PageTail(page), page);
67 VM_BUG_ON_PAGE(page_ref_count(page), page);
68 set_page_count(page, 1);
69 }
70
71 extern unsigned long highest_memmap_pfn;
72
73 /*
74 * in mm/vmscan.c:
75 */
76 extern int isolate_lru_page(struct page *page);
77 extern void putback_lru_page(struct page *page);
78 extern bool zone_reclaimable(struct zone *zone);
79
80 /*
81 * in mm/rmap.c:
82 */
83 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
84
85 /*
86 * in mm/page_alloc.c
87 */
88
89 /*
90 * Structure for holding the mostly immutable allocation parameters passed
91 * between functions involved in allocations, including the alloc_pages*
92 * family of functions.
93 *
94 * nodemask, migratetype and high_zoneidx are initialized only once in
95 * __alloc_pages_nodemask() and then never change.
96 *
97 * zonelist, preferred_zone and classzone_idx are set first in
98 * __alloc_pages_nodemask() for the fast path, and might be later changed
99 * in __alloc_pages_slowpath(). All other functions pass the whole strucure
100 * by a const pointer.
101 */
102 struct alloc_context {
103 struct zonelist *zonelist;
104 nodemask_t *nodemask;
105 struct zoneref *preferred_zoneref;
106 int migratetype;
107 enum zone_type high_zoneidx;
108 bool spread_dirty_pages;
109 };
110
111 #define ac_classzone_idx(ac) zonelist_zone_idx(ac->preferred_zoneref)
112
113 /*
114 * Locate the struct page for both the matching buddy in our
115 * pair (buddy1) and the combined O(n+1) page they form (page).
116 *
117 * 1) Any buddy B1 will have an order O twin B2 which satisfies
118 * the following equation:
119 * B2 = B1 ^ (1 << O)
120 * For example, if the starting buddy (buddy2) is #8 its order
121 * 1 buddy is #10:
122 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
123 *
124 * 2) Any buddy B will have an order O+1 parent P which
125 * satisfies the following equation:
126 * P = B & ~(1 << O)
127 *
128 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
129 */
130 static inline unsigned long
131 __find_buddy_index(unsigned long page_idx, unsigned int order)
132 {
133 return page_idx ^ (1 << order);
134 }
135
136 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
137 unsigned long end_pfn, struct zone *zone);
138
139 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
140 unsigned long end_pfn, struct zone *zone)
141 {
142 if (zone->contiguous)
143 return pfn_to_page(start_pfn);
144
145 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
146 }
147
148 extern int __isolate_free_page(struct page *page, unsigned int order);
149 extern void __free_pages_bootmem(struct page *page, unsigned long pfn,
150 unsigned int order);
151 extern void prep_compound_page(struct page *page, unsigned int order);
152 extern int user_min_free_kbytes;
153
154 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
155
156 /*
157 * in mm/compaction.c
158 */
159 /*
160 * compact_control is used to track pages being migrated and the free pages
161 * they are being migrated to during memory compaction. The free_pfn starts
162 * at the end of a zone and migrate_pfn begins at the start. Movable pages
163 * are moved to the end of a zone during a compaction run and the run
164 * completes when free_pfn <= migrate_pfn
165 */
166 struct compact_control {
167 struct list_head freepages; /* List of free pages to migrate to */
168 struct list_head migratepages; /* List of pages being migrated */
169 unsigned long nr_freepages; /* Number of isolated free pages */
170 unsigned long nr_migratepages; /* Number of pages to migrate */
171 unsigned long free_pfn; /* isolate_freepages search base */
172 unsigned long migrate_pfn; /* isolate_migratepages search base */
173 unsigned long last_migrated_pfn;/* Not yet flushed page being freed */
174 enum migrate_mode mode; /* Async or sync migration mode */
175 bool ignore_skip_hint; /* Scan blocks even if marked skip */
176 bool direct_compaction; /* False from kcompactd or /proc/... */
177 bool whole_zone; /* Whole zone has been scanned */
178 int order; /* order a direct compactor needs */
179 const gfp_t gfp_mask; /* gfp mask of a direct compactor */
180 const unsigned int alloc_flags; /* alloc flags of a direct compactor */
181 const int classzone_idx; /* zone index of a direct compactor */
182 struct zone *zone;
183 int contended; /* Signal need_sched() or lock
184 * contention detected during
185 * compaction
186 */
187 };
188
189 unsigned long
190 isolate_freepages_range(struct compact_control *cc,
191 unsigned long start_pfn, unsigned long end_pfn);
192 unsigned long
193 isolate_migratepages_range(struct compact_control *cc,
194 unsigned long low_pfn, unsigned long end_pfn);
195 int find_suitable_fallback(struct free_area *area, unsigned int order,
196 int migratetype, bool only_stealable, bool *can_steal);
197
198 #endif
199
200 /*
201 * This function returns the order of a free page in the buddy system. In
202 * general, page_zone(page)->lock must be held by the caller to prevent the
203 * page from being allocated in parallel and returning garbage as the order.
204 * If a caller does not hold page_zone(page)->lock, it must guarantee that the
205 * page cannot be allocated or merged in parallel. Alternatively, it must
206 * handle invalid values gracefully, and use page_order_unsafe() below.
207 */
208 static inline unsigned int page_order(struct page *page)
209 {
210 /* PageBuddy() must be checked by the caller */
211 return page_private(page);
212 }
213
214 /*
215 * Like page_order(), but for callers who cannot afford to hold the zone lock.
216 * PageBuddy() should be checked first by the caller to minimize race window,
217 * and invalid values must be handled gracefully.
218 *
219 * READ_ONCE is used so that if the caller assigns the result into a local
220 * variable and e.g. tests it for valid range before using, the compiler cannot
221 * decide to remove the variable and inline the page_private(page) multiple
222 * times, potentially observing different values in the tests and the actual
223 * use of the result.
224 */
225 #define page_order_unsafe(page) READ_ONCE(page_private(page))
226
227 static inline bool is_cow_mapping(vm_flags_t flags)
228 {
229 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
230 }
231
232 /*
233 * These three helpers classifies VMAs for virtual memory accounting.
234 */
235
236 /*
237 * Executable code area - executable, not writable, not stack
238 */
239 static inline bool is_exec_mapping(vm_flags_t flags)
240 {
241 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
242 }
243
244 /*
245 * Stack area - atomatically grows in one direction
246 *
247 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
248 * do_mmap() forbids all other combinations.
249 */
250 static inline bool is_stack_mapping(vm_flags_t flags)
251 {
252 return (flags & VM_STACK) == VM_STACK;
253 }
254
255 /*
256 * Data area - private, writable, not stack
257 */
258 static inline bool is_data_mapping(vm_flags_t flags)
259 {
260 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
261 }
262
263 /* mm/util.c */
264 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
265 struct vm_area_struct *prev, struct rb_node *rb_parent);
266
267 #ifdef CONFIG_MMU
268 extern long populate_vma_page_range(struct vm_area_struct *vma,
269 unsigned long start, unsigned long end, int *nonblocking);
270 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
271 unsigned long start, unsigned long end);
272 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
273 {
274 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
275 }
276
277 /*
278 * must be called with vma's mmap_sem held for read or write, and page locked.
279 */
280 extern void mlock_vma_page(struct page *page);
281 extern unsigned int munlock_vma_page(struct page *page);
282
283 /*
284 * Clear the page's PageMlocked(). This can be useful in a situation where
285 * we want to unconditionally remove a page from the pagecache -- e.g.,
286 * on truncation or freeing.
287 *
288 * It is legal to call this function for any page, mlocked or not.
289 * If called for a page that is still mapped by mlocked vmas, all we do
290 * is revert to lazy LRU behaviour -- semantics are not broken.
291 */
292 extern void clear_page_mlock(struct page *page);
293
294 /*
295 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page()
296 * (because that does not go through the full procedure of migration ptes):
297 * to migrate the Mlocked page flag; update statistics.
298 */
299 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
300 {
301 if (TestClearPageMlocked(page)) {
302 int nr_pages = hpage_nr_pages(page);
303
304 /* Holding pmd lock, no change in irq context: __mod is safe */
305 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
306 SetPageMlocked(newpage);
307 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
308 }
309 }
310
311 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
312
313 /*
314 * At what user virtual address is page expected in @vma?
315 */
316 static inline unsigned long
317 __vma_address(struct page *page, struct vm_area_struct *vma)
318 {
319 pgoff_t pgoff = page_to_pgoff(page);
320 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
321 }
322
323 static inline unsigned long
324 vma_address(struct page *page, struct vm_area_struct *vma)
325 {
326 unsigned long address = __vma_address(page, vma);
327
328 /* page should be within @vma mapping range */
329 VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma);
330
331 return address;
332 }
333
334 #else /* !CONFIG_MMU */
335 static inline void clear_page_mlock(struct page *page) { }
336 static inline void mlock_vma_page(struct page *page) { }
337 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
338
339 #endif /* !CONFIG_MMU */
340
341 /*
342 * Return the mem_map entry representing the 'offset' subpage within
343 * the maximally aligned gigantic page 'base'. Handle any discontiguity
344 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
345 */
346 static inline struct page *mem_map_offset(struct page *base, int offset)
347 {
348 if (unlikely(offset >= MAX_ORDER_NR_PAGES))
349 return nth_page(base, offset);
350 return base + offset;
351 }
352
353 /*
354 * Iterator over all subpages within the maximally aligned gigantic
355 * page 'base'. Handle any discontiguity in the mem_map.
356 */
357 static inline struct page *mem_map_next(struct page *iter,
358 struct page *base, int offset)
359 {
360 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
361 unsigned long pfn = page_to_pfn(base) + offset;
362 if (!pfn_valid(pfn))
363 return NULL;
364 return pfn_to_page(pfn);
365 }
366 return iter + 1;
367 }
368
369 /*
370 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
371 * so all functions starting at paging_init should be marked __init
372 * in those cases. SPARSEMEM, however, allows for memory hotplug,
373 * and alloc_bootmem_node is not used.
374 */
375 #ifdef CONFIG_SPARSEMEM
376 #define __paginginit __meminit
377 #else
378 #define __paginginit __init
379 #endif
380
381 /* Memory initialisation debug and verification */
382 enum mminit_level {
383 MMINIT_WARNING,
384 MMINIT_VERIFY,
385 MMINIT_TRACE
386 };
387
388 #ifdef CONFIG_DEBUG_MEMORY_INIT
389
390 extern int mminit_loglevel;
391
392 #define mminit_dprintk(level, prefix, fmt, arg...) \
393 do { \
394 if (level < mminit_loglevel) { \
395 if (level <= MMINIT_WARNING) \
396 pr_warn("mminit::" prefix " " fmt, ##arg); \
397 else \
398 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
399 } \
400 } while (0)
401
402 extern void mminit_verify_pageflags_layout(void);
403 extern void mminit_verify_zonelist(void);
404 #else
405
406 static inline void mminit_dprintk(enum mminit_level level,
407 const char *prefix, const char *fmt, ...)
408 {
409 }
410
411 static inline void mminit_verify_pageflags_layout(void)
412 {
413 }
414
415 static inline void mminit_verify_zonelist(void)
416 {
417 }
418 #endif /* CONFIG_DEBUG_MEMORY_INIT */
419
420 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
421 #if defined(CONFIG_SPARSEMEM)
422 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
423 unsigned long *end_pfn);
424 #else
425 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
426 unsigned long *end_pfn)
427 {
428 }
429 #endif /* CONFIG_SPARSEMEM */
430
431 #define ZONE_RECLAIM_NOSCAN -2
432 #define ZONE_RECLAIM_FULL -1
433 #define ZONE_RECLAIM_SOME 0
434 #define ZONE_RECLAIM_SUCCESS 1
435
436 extern int hwpoison_filter(struct page *p);
437
438 extern u32 hwpoison_filter_dev_major;
439 extern u32 hwpoison_filter_dev_minor;
440 extern u64 hwpoison_filter_flags_mask;
441 extern u64 hwpoison_filter_flags_value;
442 extern u64 hwpoison_filter_memcg;
443 extern u32 hwpoison_filter_enable;
444
445 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
446 unsigned long, unsigned long,
447 unsigned long, unsigned long);
448
449 extern void set_pageblock_order(void);
450 unsigned long reclaim_clean_pages_from_list(struct zone *zone,
451 struct list_head *page_list);
452 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
453 #define ALLOC_WMARK_MIN WMARK_MIN
454 #define ALLOC_WMARK_LOW WMARK_LOW
455 #define ALLOC_WMARK_HIGH WMARK_HIGH
456 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
457
458 /* Mask to get the watermark bits */
459 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
460
461 #define ALLOC_HARDER 0x10 /* try to alloc harder */
462 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
463 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
464 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
465 #define ALLOC_FAIR 0x100 /* fair zone allocation */
466
467 enum ttu_flags;
468 struct tlbflush_unmap_batch;
469
470 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
471 void try_to_unmap_flush(void);
472 void try_to_unmap_flush_dirty(void);
473 #else
474 static inline void try_to_unmap_flush(void)
475 {
476 }
477 static inline void try_to_unmap_flush_dirty(void)
478 {
479 }
480
481 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
482
483 extern const struct trace_print_flags pageflag_names[];
484 extern const struct trace_print_flags vmaflag_names[];
485 extern const struct trace_print_flags gfpflag_names[];
486
487 #endif /* __MM_INTERNAL_H */