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 int 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 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 __free_pages_bootmem(struct page *page, unsigned long pfn, 165 unsigned int order); 166 extern void prep_compound_page(struct page *page, unsigned int order); 167 extern void post_alloc_hook(struct page *page, unsigned int order, 168 gfp_t gfp_flags); 169 extern int user_min_free_kbytes; 170 171 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 172 173 /* 174 * in mm/compaction.c 175 */ 176 /* 177 * compact_control is used to track pages being migrated and the free pages 178 * they are being migrated to during memory compaction. The free_pfn starts 179 * at the end of a zone and migrate_pfn begins at the start. Movable pages 180 * are moved to the end of a zone during a compaction run and the run 181 * completes when free_pfn <= migrate_pfn 182 */ 183 struct compact_control { 184 struct list_head freepages; /* List of free pages to migrate to */ 185 struct list_head migratepages; /* List of pages being migrated */ 186 struct zone *zone; 187 unsigned long nr_freepages; /* Number of isolated free pages */ 188 unsigned long nr_migratepages; /* Number of pages to migrate */ 189 unsigned long total_migrate_scanned; 190 unsigned long total_free_scanned; 191 unsigned long free_pfn; /* isolate_freepages search base */ 192 unsigned long migrate_pfn; /* isolate_migratepages search base */ 193 unsigned long last_migrated_pfn;/* Not yet flushed page being freed */ 194 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 195 int order; /* order a direct compactor needs */ 196 int migratetype; /* migratetype of direct compactor */ 197 const unsigned int alloc_flags; /* alloc flags of a direct compactor */ 198 const int classzone_idx; /* zone index of a direct compactor */ 199 enum migrate_mode mode; /* Async or sync migration mode */ 200 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 201 bool ignore_block_suitable; /* Scan blocks considered unsuitable */ 202 bool direct_compaction; /* False from kcompactd or /proc/... */ 203 bool whole_zone; /* Whole zone should/has been scanned */ 204 bool contended; /* Signal lock or sched contention */ 205 bool finishing_block; /* Finishing current pageblock */ 206 }; 207 208 unsigned long 209 isolate_freepages_range(struct compact_control *cc, 210 unsigned long start_pfn, unsigned long end_pfn); 211 unsigned long 212 isolate_migratepages_range(struct compact_control *cc, 213 unsigned long low_pfn, unsigned long end_pfn); 214 int find_suitable_fallback(struct free_area *area, unsigned int order, 215 int migratetype, bool only_stealable, bool *can_steal); 216 217 #endif 218 219 /* 220 * This function returns the order of a free page in the buddy system. In 221 * general, page_zone(page)->lock must be held by the caller to prevent the 222 * page from being allocated in parallel and returning garbage as the order. 223 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 224 * page cannot be allocated or merged in parallel. Alternatively, it must 225 * handle invalid values gracefully, and use page_order_unsafe() below. 226 */ 227 static inline unsigned int page_order(struct page *page) 228 { 229 /* PageBuddy() must be checked by the caller */ 230 return page_private(page); 231 } 232 233 /* 234 * Like page_order(), but for callers who cannot afford to hold the zone lock. 235 * PageBuddy() should be checked first by the caller to minimize race window, 236 * and invalid values must be handled gracefully. 237 * 238 * READ_ONCE is used so that if the caller assigns the result into a local 239 * variable and e.g. tests it for valid range before using, the compiler cannot 240 * decide to remove the variable and inline the page_private(page) multiple 241 * times, potentially observing different values in the tests and the actual 242 * use of the result. 243 */ 244 #define page_order_unsafe(page) READ_ONCE(page_private(page)) 245 246 static inline bool is_cow_mapping(vm_flags_t flags) 247 { 248 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 249 } 250 251 /* 252 * These three helpers classifies VMAs for virtual memory accounting. 253 */ 254 255 /* 256 * Executable code area - executable, not writable, not stack 257 */ 258 static inline bool is_exec_mapping(vm_flags_t flags) 259 { 260 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; 261 } 262 263 /* 264 * Stack area - atomatically grows in one direction 265 * 266 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous: 267 * do_mmap() forbids all other combinations. 268 */ 269 static inline bool is_stack_mapping(vm_flags_t flags) 270 { 271 return (flags & VM_STACK) == VM_STACK; 272 } 273 274 /* 275 * Data area - private, writable, not stack 276 */ 277 static inline bool is_data_mapping(vm_flags_t flags) 278 { 279 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; 280 } 281 282 /* mm/util.c */ 283 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 284 struct vm_area_struct *prev, struct rb_node *rb_parent); 285 286 #ifdef CONFIG_MMU 287 extern long populate_vma_page_range(struct vm_area_struct *vma, 288 unsigned long start, unsigned long end, int *nonblocking); 289 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 290 unsigned long start, unsigned long end); 291 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 292 { 293 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 294 } 295 296 /* 297 * must be called with vma's mmap_sem held for read or write, and page locked. 298 */ 299 extern void mlock_vma_page(struct page *page); 300 extern unsigned int munlock_vma_page(struct page *page); 301 302 /* 303 * Clear the page's PageMlocked(). This can be useful in a situation where 304 * we want to unconditionally remove a page from the pagecache -- e.g., 305 * on truncation or freeing. 306 * 307 * It is legal to call this function for any page, mlocked or not. 308 * If called for a page that is still mapped by mlocked vmas, all we do 309 * is revert to lazy LRU behaviour -- semantics are not broken. 310 */ 311 extern void clear_page_mlock(struct page *page); 312 313 /* 314 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page() 315 * (because that does not go through the full procedure of migration ptes): 316 * to migrate the Mlocked page flag; update statistics. 317 */ 318 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 319 { 320 if (TestClearPageMlocked(page)) { 321 int nr_pages = hpage_nr_pages(page); 322 323 /* Holding pmd lock, no change in irq context: __mod is safe */ 324 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); 325 SetPageMlocked(newpage); 326 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages); 327 } 328 } 329 330 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 331 332 /* 333 * At what user virtual address is page expected in @vma? 334 */ 335 static inline unsigned long 336 __vma_address(struct page *page, struct vm_area_struct *vma) 337 { 338 pgoff_t pgoff = page_to_pgoff(page); 339 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 340 } 341 342 static inline unsigned long 343 vma_address(struct page *page, struct vm_area_struct *vma) 344 { 345 unsigned long start, end; 346 347 start = __vma_address(page, vma); 348 end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1); 349 350 /* page should be within @vma mapping range */ 351 VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma); 352 353 return max(start, vma->vm_start); 354 } 355 356 #else /* !CONFIG_MMU */ 357 static inline void clear_page_mlock(struct page *page) { } 358 static inline void mlock_vma_page(struct page *page) { } 359 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 360 361 #endif /* !CONFIG_MMU */ 362 363 /* 364 * Return the mem_map entry representing the 'offset' subpage within 365 * the maximally aligned gigantic page 'base'. Handle any discontiguity 366 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 367 */ 368 static inline struct page *mem_map_offset(struct page *base, int offset) 369 { 370 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 371 return nth_page(base, offset); 372 return base + offset; 373 } 374 375 /* 376 * Iterator over all subpages within the maximally aligned gigantic 377 * page 'base'. Handle any discontiguity in the mem_map. 378 */ 379 static inline struct page *mem_map_next(struct page *iter, 380 struct page *base, int offset) 381 { 382 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 383 unsigned long pfn = page_to_pfn(base) + offset; 384 if (!pfn_valid(pfn)) 385 return NULL; 386 return pfn_to_page(pfn); 387 } 388 return iter + 1; 389 } 390 391 /* 392 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 393 * so all functions starting at paging_init should be marked __init 394 * in those cases. SPARSEMEM, however, allows for memory hotplug, 395 * and alloc_bootmem_node is not used. 396 */ 397 #ifdef CONFIG_SPARSEMEM 398 #define __paginginit __meminit 399 #else 400 #define __paginginit __init 401 #endif 402 403 /* Memory initialisation debug and verification */ 404 enum mminit_level { 405 MMINIT_WARNING, 406 MMINIT_VERIFY, 407 MMINIT_TRACE 408 }; 409 410 #ifdef CONFIG_DEBUG_MEMORY_INIT 411 412 extern int mminit_loglevel; 413 414 #define mminit_dprintk(level, prefix, fmt, arg...) \ 415 do { \ 416 if (level < mminit_loglevel) { \ 417 if (level <= MMINIT_WARNING) \ 418 pr_warn("mminit::" prefix " " fmt, ##arg); \ 419 else \ 420 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 421 } \ 422 } while (0) 423 424 extern void mminit_verify_pageflags_layout(void); 425 extern void mminit_verify_zonelist(void); 426 #else 427 428 static inline void mminit_dprintk(enum mminit_level level, 429 const char *prefix, const char *fmt, ...) 430 { 431 } 432 433 static inline void mminit_verify_pageflags_layout(void) 434 { 435 } 436 437 static inline void mminit_verify_zonelist(void) 438 { 439 } 440 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 441 442 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 443 #if defined(CONFIG_SPARSEMEM) 444 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 445 unsigned long *end_pfn); 446 #else 447 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 448 unsigned long *end_pfn) 449 { 450 } 451 #endif /* CONFIG_SPARSEMEM */ 452 453 #define NODE_RECLAIM_NOSCAN -2 454 #define NODE_RECLAIM_FULL -1 455 #define NODE_RECLAIM_SOME 0 456 #define NODE_RECLAIM_SUCCESS 1 457 458 extern int hwpoison_filter(struct page *p); 459 460 extern u32 hwpoison_filter_dev_major; 461 extern u32 hwpoison_filter_dev_minor; 462 extern u64 hwpoison_filter_flags_mask; 463 extern u64 hwpoison_filter_flags_value; 464 extern u64 hwpoison_filter_memcg; 465 extern u32 hwpoison_filter_enable; 466 467 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 468 unsigned long, unsigned long, 469 unsigned long, unsigned long); 470 471 extern void set_pageblock_order(void); 472 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 473 struct list_head *page_list); 474 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 475 #define ALLOC_WMARK_MIN WMARK_MIN 476 #define ALLOC_WMARK_LOW WMARK_LOW 477 #define ALLOC_WMARK_HIGH WMARK_HIGH 478 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 479 480 /* Mask to get the watermark bits */ 481 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 482 483 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 484 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 485 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 486 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 487 488 enum ttu_flags; 489 struct tlbflush_unmap_batch; 490 491 492 /* 493 * only for MM internal work items which do not depend on 494 * any allocations or locks which might depend on allocations 495 */ 496 extern struct workqueue_struct *mm_percpu_wq; 497 498 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 499 void try_to_unmap_flush(void); 500 void try_to_unmap_flush_dirty(void); 501 #else 502 static inline void try_to_unmap_flush(void) 503 { 504 } 505 static inline void try_to_unmap_flush_dirty(void) 506 { 507 } 508 509 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 510 511 extern const struct trace_print_flags pageflag_names[]; 512 extern const struct trace_print_flags vmaflag_names[]; 513 extern const struct trace_print_flags gfpflag_names[]; 514 515 static inline bool is_migrate_highatomic(enum migratetype migratetype) 516 { 517 return migratetype == MIGRATE_HIGHATOMIC; 518 } 519 520 static inline bool is_migrate_highatomic_page(struct page *page) 521 { 522 return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC; 523 } 524 525 #endif /* __MM_INTERNAL_H */ 526