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_RETRY_MAYFAIL|__GFP_NOFAIL|\ 27 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\ 28 __GFP_ATOMIC) 29 30 /* The GFP flags allowed during early boot */ 31 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS)) 32 33 /* Control allocation cpuset and node placement constraints */ 34 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE) 35 36 /* Do not use these with a slab allocator */ 37 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) 38 39 void page_writeback_init(void); 40 41 vm_fault_t do_swap_page(struct vm_fault *vmf); 42 43 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, 44 unsigned long floor, unsigned long ceiling); 45 46 static inline bool can_madv_dontneed_vma(struct vm_area_struct *vma) 47 { 48 return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)); 49 } 50 51 void unmap_page_range(struct mmu_gather *tlb, 52 struct vm_area_struct *vma, 53 unsigned long addr, unsigned long end, 54 struct zap_details *details); 55 56 extern unsigned int __do_page_cache_readahead(struct address_space *mapping, 57 struct file *filp, pgoff_t offset, unsigned long nr_to_read, 58 unsigned long lookahead_size); 59 60 /* 61 * Submit IO for the read-ahead request in file_ra_state. 62 */ 63 static inline unsigned long ra_submit(struct file_ra_state *ra, 64 struct address_space *mapping, struct file *filp) 65 { 66 return __do_page_cache_readahead(mapping, filp, 67 ra->start, ra->size, ra->async_size); 68 } 69 70 /* 71 * Turn a non-refcounted page (->_refcount == 0) into refcounted with 72 * a count of one. 73 */ 74 static inline void set_page_refcounted(struct page *page) 75 { 76 VM_BUG_ON_PAGE(PageTail(page), page); 77 VM_BUG_ON_PAGE(page_ref_count(page), page); 78 set_page_count(page, 1); 79 } 80 81 extern unsigned long highest_memmap_pfn; 82 83 /* 84 * Maximum number of reclaim retries without progress before the OOM 85 * killer is consider the only way forward. 86 */ 87 #define MAX_RECLAIM_RETRIES 16 88 89 /* 90 * in mm/vmscan.c: 91 */ 92 extern int isolate_lru_page(struct page *page); 93 extern void putback_lru_page(struct page *page); 94 95 /* 96 * in mm/rmap.c: 97 */ 98 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 99 100 /* 101 * in mm/page_alloc.c 102 */ 103 104 /* 105 * Structure for holding the mostly immutable allocation parameters passed 106 * between functions involved in allocations, including the alloc_pages* 107 * family of functions. 108 * 109 * nodemask, migratetype and high_zoneidx are initialized only once in 110 * __alloc_pages_nodemask() and then never change. 111 * 112 * zonelist, preferred_zone and classzone_idx are set first in 113 * __alloc_pages_nodemask() for the fast path, and might be later changed 114 * in __alloc_pages_slowpath(). All other functions pass the whole strucure 115 * by a const pointer. 116 */ 117 struct alloc_context { 118 struct zonelist *zonelist; 119 nodemask_t *nodemask; 120 struct zoneref *preferred_zoneref; 121 int migratetype; 122 enum zone_type high_zoneidx; 123 bool spread_dirty_pages; 124 }; 125 126 #define ac_classzone_idx(ac) zonelist_zone_idx(ac->preferred_zoneref) 127 128 /* 129 * Locate the struct page for both the matching buddy in our 130 * pair (buddy1) and the combined O(n+1) page they form (page). 131 * 132 * 1) Any buddy B1 will have an order O twin B2 which satisfies 133 * the following equation: 134 * B2 = B1 ^ (1 << O) 135 * For example, if the starting buddy (buddy2) is #8 its order 136 * 1 buddy is #10: 137 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 138 * 139 * 2) Any buddy B will have an order O+1 parent P which 140 * satisfies the following equation: 141 * P = B & ~(1 << O) 142 * 143 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 144 */ 145 static inline unsigned long 146 __find_buddy_pfn(unsigned long page_pfn, unsigned int order) 147 { 148 return page_pfn ^ (1 << order); 149 } 150 151 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn, 152 unsigned long end_pfn, struct zone *zone); 153 154 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn, 155 unsigned long end_pfn, struct zone *zone) 156 { 157 if (zone->contiguous) 158 return pfn_to_page(start_pfn); 159 160 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone); 161 } 162 163 extern int __isolate_free_page(struct page *page, unsigned int order); 164 extern void memblock_free_pages(struct page *page, unsigned long pfn, 165 unsigned int order); 166 extern void __free_pages_core(struct page *page, unsigned int order); 167 extern void prep_compound_page(struct page *page, unsigned int order); 168 extern void post_alloc_hook(struct page *page, unsigned int order, 169 gfp_t gfp_flags); 170 extern int user_min_free_kbytes; 171 172 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 173 174 /* 175 * in mm/compaction.c 176 */ 177 /* 178 * compact_control is used to track pages being migrated and the free pages 179 * they are being migrated to during memory compaction. The free_pfn starts 180 * at the end of a zone and migrate_pfn begins at the start. Movable pages 181 * are moved to the end of a zone during a compaction run and the run 182 * completes when free_pfn <= migrate_pfn 183 */ 184 struct compact_control { 185 struct list_head freepages; /* List of free pages to migrate to */ 186 struct list_head migratepages; /* List of pages being migrated */ 187 unsigned int nr_freepages; /* Number of isolated free pages */ 188 unsigned int nr_migratepages; /* Number of pages to migrate */ 189 unsigned long free_pfn; /* isolate_freepages search base */ 190 unsigned long migrate_pfn; /* isolate_migratepages search base */ 191 unsigned long fast_start_pfn; /* a pfn to start linear scan from */ 192 struct zone *zone; 193 unsigned long total_migrate_scanned; 194 unsigned long total_free_scanned; 195 unsigned short fast_search_fail;/* failures to use free list searches */ 196 short search_order; /* order to start a fast search at */ 197 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 198 int order; /* order a direct compactor needs */ 199 int migratetype; /* migratetype of direct compactor */ 200 const unsigned int alloc_flags; /* alloc flags of a direct compactor */ 201 const int classzone_idx; /* zone index of a direct compactor */ 202 enum migrate_mode mode; /* Async or sync migration mode */ 203 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 204 bool no_set_skip_hint; /* Don't mark blocks for skipping */ 205 bool ignore_block_suitable; /* Scan blocks considered unsuitable */ 206 bool direct_compaction; /* False from kcompactd or /proc/... */ 207 bool whole_zone; /* Whole zone should/has been scanned */ 208 bool contended; /* Signal lock or sched contention */ 209 bool rescan; /* Rescanning the same pageblock */ 210 }; 211 212 /* 213 * Used in direct compaction when a page should be taken from the freelists 214 * immediately when one is created during the free path. 215 */ 216 struct capture_control { 217 struct compact_control *cc; 218 struct page *page; 219 }; 220 221 unsigned long 222 isolate_freepages_range(struct compact_control *cc, 223 unsigned long start_pfn, unsigned long end_pfn); 224 unsigned long 225 isolate_migratepages_range(struct compact_control *cc, 226 unsigned long low_pfn, unsigned long end_pfn); 227 int find_suitable_fallback(struct free_area *area, unsigned int order, 228 int migratetype, bool only_stealable, bool *can_steal); 229 230 #endif 231 232 /* 233 * This function returns the order of a free page in the buddy system. In 234 * general, page_zone(page)->lock must be held by the caller to prevent the 235 * page from being allocated in parallel and returning garbage as the order. 236 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 237 * page cannot be allocated or merged in parallel. Alternatively, it must 238 * handle invalid values gracefully, and use page_order_unsafe() below. 239 */ 240 static inline unsigned int page_order(struct page *page) 241 { 242 /* PageBuddy() must be checked by the caller */ 243 return page_private(page); 244 } 245 246 /* 247 * Like page_order(), but for callers who cannot afford to hold the zone lock. 248 * PageBuddy() should be checked first by the caller to minimize race window, 249 * and invalid values must be handled gracefully. 250 * 251 * READ_ONCE is used so that if the caller assigns the result into a local 252 * variable and e.g. tests it for valid range before using, the compiler cannot 253 * decide to remove the variable and inline the page_private(page) multiple 254 * times, potentially observing different values in the tests and the actual 255 * use of the result. 256 */ 257 #define page_order_unsafe(page) READ_ONCE(page_private(page)) 258 259 static inline bool is_cow_mapping(vm_flags_t flags) 260 { 261 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 262 } 263 264 /* 265 * These three helpers classifies VMAs for virtual memory accounting. 266 */ 267 268 /* 269 * Executable code area - executable, not writable, not stack 270 */ 271 static inline bool is_exec_mapping(vm_flags_t flags) 272 { 273 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; 274 } 275 276 /* 277 * Stack area - atomatically grows in one direction 278 * 279 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous: 280 * do_mmap() forbids all other combinations. 281 */ 282 static inline bool is_stack_mapping(vm_flags_t flags) 283 { 284 return (flags & VM_STACK) == VM_STACK; 285 } 286 287 /* 288 * Data area - private, writable, not stack 289 */ 290 static inline bool is_data_mapping(vm_flags_t flags) 291 { 292 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; 293 } 294 295 /* mm/util.c */ 296 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 297 struct vm_area_struct *prev, struct rb_node *rb_parent); 298 299 #ifdef CONFIG_MMU 300 extern long populate_vma_page_range(struct vm_area_struct *vma, 301 unsigned long start, unsigned long end, int *nonblocking); 302 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 303 unsigned long start, unsigned long end); 304 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 305 { 306 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 307 } 308 309 /* 310 * must be called with vma's mmap_sem held for read or write, and page locked. 311 */ 312 extern void mlock_vma_page(struct page *page); 313 extern unsigned int munlock_vma_page(struct page *page); 314 315 /* 316 * Clear the page's PageMlocked(). This can be useful in a situation where 317 * we want to unconditionally remove a page from the pagecache -- e.g., 318 * on truncation or freeing. 319 * 320 * It is legal to call this function for any page, mlocked or not. 321 * If called for a page that is still mapped by mlocked vmas, all we do 322 * is revert to lazy LRU behaviour -- semantics are not broken. 323 */ 324 extern void clear_page_mlock(struct page *page); 325 326 /* 327 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page() 328 * (because that does not go through the full procedure of migration ptes): 329 * to migrate the Mlocked page flag; update statistics. 330 */ 331 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 332 { 333 if (TestClearPageMlocked(page)) { 334 int nr_pages = hpage_nr_pages(page); 335 336 /* Holding pmd lock, no change in irq context: __mod is safe */ 337 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); 338 SetPageMlocked(newpage); 339 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages); 340 } 341 } 342 343 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 344 345 /* 346 * At what user virtual address is page expected in @vma? 347 */ 348 static inline unsigned long 349 __vma_address(struct page *page, struct vm_area_struct *vma) 350 { 351 pgoff_t pgoff = page_to_pgoff(page); 352 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 353 } 354 355 static inline unsigned long 356 vma_address(struct page *page, struct vm_area_struct *vma) 357 { 358 unsigned long start, end; 359 360 start = __vma_address(page, vma); 361 end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1); 362 363 /* page should be within @vma mapping range */ 364 VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma); 365 366 return max(start, vma->vm_start); 367 } 368 369 #else /* !CONFIG_MMU */ 370 static inline void clear_page_mlock(struct page *page) { } 371 static inline void mlock_vma_page(struct page *page) { } 372 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 373 374 #endif /* !CONFIG_MMU */ 375 376 /* 377 * Return the mem_map entry representing the 'offset' subpage within 378 * the maximally aligned gigantic page 'base'. Handle any discontiguity 379 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 380 */ 381 static inline struct page *mem_map_offset(struct page *base, int offset) 382 { 383 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 384 return nth_page(base, offset); 385 return base + offset; 386 } 387 388 /* 389 * Iterator over all subpages within the maximally aligned gigantic 390 * page 'base'. Handle any discontiguity in the mem_map. 391 */ 392 static inline struct page *mem_map_next(struct page *iter, 393 struct page *base, int offset) 394 { 395 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 396 unsigned long pfn = page_to_pfn(base) + offset; 397 if (!pfn_valid(pfn)) 398 return NULL; 399 return pfn_to_page(pfn); 400 } 401 return iter + 1; 402 } 403 404 /* Memory initialisation debug and verification */ 405 enum mminit_level { 406 MMINIT_WARNING, 407 MMINIT_VERIFY, 408 MMINIT_TRACE 409 }; 410 411 #ifdef CONFIG_DEBUG_MEMORY_INIT 412 413 extern int mminit_loglevel; 414 415 #define mminit_dprintk(level, prefix, fmt, arg...) \ 416 do { \ 417 if (level < mminit_loglevel) { \ 418 if (level <= MMINIT_WARNING) \ 419 pr_warn("mminit::" prefix " " fmt, ##arg); \ 420 else \ 421 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 422 } \ 423 } while (0) 424 425 extern void mminit_verify_pageflags_layout(void); 426 extern void mminit_verify_zonelist(void); 427 #else 428 429 static inline void mminit_dprintk(enum mminit_level level, 430 const char *prefix, const char *fmt, ...) 431 { 432 } 433 434 static inline void mminit_verify_pageflags_layout(void) 435 { 436 } 437 438 static inline void mminit_verify_zonelist(void) 439 { 440 } 441 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 442 443 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 444 #if defined(CONFIG_SPARSEMEM) 445 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 446 unsigned long *end_pfn); 447 #else 448 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 449 unsigned long *end_pfn) 450 { 451 } 452 #endif /* CONFIG_SPARSEMEM */ 453 454 #define NODE_RECLAIM_NOSCAN -2 455 #define NODE_RECLAIM_FULL -1 456 #define NODE_RECLAIM_SOME 0 457 #define NODE_RECLAIM_SUCCESS 1 458 459 #ifdef CONFIG_NUMA 460 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); 461 #else 462 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, 463 unsigned int order) 464 { 465 return NODE_RECLAIM_NOSCAN; 466 } 467 #endif 468 469 extern int hwpoison_filter(struct page *p); 470 471 extern u32 hwpoison_filter_dev_major; 472 extern u32 hwpoison_filter_dev_minor; 473 extern u64 hwpoison_filter_flags_mask; 474 extern u64 hwpoison_filter_flags_value; 475 extern u64 hwpoison_filter_memcg; 476 extern u32 hwpoison_filter_enable; 477 478 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 479 unsigned long, unsigned long, 480 unsigned long, unsigned long); 481 482 extern void set_pageblock_order(void); 483 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 484 struct list_head *page_list); 485 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 486 #define ALLOC_WMARK_MIN WMARK_MIN 487 #define ALLOC_WMARK_LOW WMARK_LOW 488 #define ALLOC_WMARK_HIGH WMARK_HIGH 489 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 490 491 /* Mask to get the watermark bits */ 492 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 493 494 /* 495 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we 496 * cannot assume a reduced access to memory reserves is sufficient for 497 * !MMU 498 */ 499 #ifdef CONFIG_MMU 500 #define ALLOC_OOM 0x08 501 #else 502 #define ALLOC_OOM ALLOC_NO_WATERMARKS 503 #endif 504 505 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 506 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 507 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 508 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 509 #ifdef CONFIG_ZONE_DMA32 510 #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */ 511 #else 512 #define ALLOC_NOFRAGMENT 0x0 513 #endif 514 #define ALLOC_KSWAPD 0x200 /* allow waking of kswapd */ 515 516 enum ttu_flags; 517 struct tlbflush_unmap_batch; 518 519 520 /* 521 * only for MM internal work items which do not depend on 522 * any allocations or locks which might depend on allocations 523 */ 524 extern struct workqueue_struct *mm_percpu_wq; 525 526 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 527 void try_to_unmap_flush(void); 528 void try_to_unmap_flush_dirty(void); 529 void flush_tlb_batched_pending(struct mm_struct *mm); 530 #else 531 static inline void try_to_unmap_flush(void) 532 { 533 } 534 static inline void try_to_unmap_flush_dirty(void) 535 { 536 } 537 static inline void flush_tlb_batched_pending(struct mm_struct *mm) 538 { 539 } 540 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 541 542 extern const struct trace_print_flags pageflag_names[]; 543 extern const struct trace_print_flags vmaflag_names[]; 544 extern const struct trace_print_flags gfpflag_names[]; 545 546 static inline bool is_migrate_highatomic(enum migratetype migratetype) 547 { 548 return migratetype == MIGRATE_HIGHATOMIC; 549 } 550 551 static inline bool is_migrate_highatomic_page(struct page *page) 552 { 553 return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC; 554 } 555 556 void setup_zone_pageset(struct zone *zone); 557 extern struct page *alloc_new_node_page(struct page *page, unsigned long node); 558 #endif /* __MM_INTERNAL_H */ 559