1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* internal.h: mm/ internal definitions 3 * 4 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 #ifndef __MM_INTERNAL_H 8 #define __MM_INTERNAL_H 9 10 #include <linux/fs.h> 11 #include <linux/mm.h> 12 #include <linux/pagemap.h> 13 #include <linux/tracepoint-defs.h> 14 15 /* 16 * The set of flags that only affect watermark checking and reclaim 17 * behaviour. This is used by the MM to obey the caller constraints 18 * about IO, FS and watermark checking while ignoring placement 19 * hints such as HIGHMEM usage. 20 */ 21 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\ 22 __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\ 23 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\ 24 __GFP_ATOMIC) 25 26 /* The GFP flags allowed during early boot */ 27 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS)) 28 29 /* Control allocation cpuset and node placement constraints */ 30 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE) 31 32 /* Do not use these with a slab allocator */ 33 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) 34 35 void page_writeback_init(void); 36 37 vm_fault_t do_swap_page(struct vm_fault *vmf); 38 39 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, 40 unsigned long floor, unsigned long ceiling); 41 42 static inline bool can_madv_lru_vma(struct vm_area_struct *vma) 43 { 44 return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)); 45 } 46 47 void unmap_page_range(struct mmu_gather *tlb, 48 struct vm_area_struct *vma, 49 unsigned long addr, unsigned long end, 50 struct zap_details *details); 51 52 extern unsigned int __do_page_cache_readahead(struct address_space *mapping, 53 struct file *filp, pgoff_t offset, unsigned long nr_to_read, 54 unsigned long lookahead_size); 55 56 /* 57 * Submit IO for the read-ahead request in file_ra_state. 58 */ 59 static inline unsigned long ra_submit(struct file_ra_state *ra, 60 struct address_space *mapping, struct file *filp) 61 { 62 return __do_page_cache_readahead(mapping, filp, 63 ra->start, ra->size, ra->async_size); 64 } 65 66 /* 67 * Turn a non-refcounted page (->_refcount == 0) into refcounted with 68 * a count of one. 69 */ 70 static inline void set_page_refcounted(struct page *page) 71 { 72 VM_BUG_ON_PAGE(PageTail(page), page); 73 VM_BUG_ON_PAGE(page_ref_count(page), page); 74 set_page_count(page, 1); 75 } 76 77 extern unsigned long highest_memmap_pfn; 78 79 /* 80 * Maximum number of reclaim retries without progress before the OOM 81 * killer is consider the only way forward. 82 */ 83 #define MAX_RECLAIM_RETRIES 16 84 85 /* 86 * in mm/vmscan.c: 87 */ 88 extern int isolate_lru_page(struct page *page); 89 extern void putback_lru_page(struct page *page); 90 91 /* 92 * in mm/rmap.c: 93 */ 94 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 95 96 /* 97 * in mm/page_alloc.c 98 */ 99 100 /* 101 * Structure for holding the mostly immutable allocation parameters passed 102 * between functions involved in allocations, including the alloc_pages* 103 * family of functions. 104 * 105 * nodemask, migratetype and high_zoneidx are initialized only once in 106 * __alloc_pages_nodemask() and then never change. 107 * 108 * zonelist, preferred_zone and classzone_idx are set first in 109 * __alloc_pages_nodemask() for the fast path, and might be later changed 110 * in __alloc_pages_slowpath(). All other functions pass the whole strucure 111 * by a const pointer. 112 */ 113 struct alloc_context { 114 struct zonelist *zonelist; 115 nodemask_t *nodemask; 116 struct zoneref *preferred_zoneref; 117 int migratetype; 118 enum zone_type high_zoneidx; 119 bool spread_dirty_pages; 120 }; 121 122 #define ac_classzone_idx(ac) zonelist_zone_idx(ac->preferred_zoneref) 123 124 /* 125 * Locate the struct page for both the matching buddy in our 126 * pair (buddy1) and the combined O(n+1) page they form (page). 127 * 128 * 1) Any buddy B1 will have an order O twin B2 which satisfies 129 * the following equation: 130 * B2 = B1 ^ (1 << O) 131 * For example, if the starting buddy (buddy2) is #8 its order 132 * 1 buddy is #10: 133 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 134 * 135 * 2) Any buddy B will have an order O+1 parent P which 136 * satisfies the following equation: 137 * P = B & ~(1 << O) 138 * 139 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 140 */ 141 static inline unsigned long 142 __find_buddy_pfn(unsigned long page_pfn, unsigned int order) 143 { 144 return page_pfn ^ (1 << order); 145 } 146 147 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn, 148 unsigned long end_pfn, struct zone *zone); 149 150 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn, 151 unsigned long end_pfn, struct zone *zone) 152 { 153 if (zone->contiguous) 154 return pfn_to_page(start_pfn); 155 156 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone); 157 } 158 159 extern int __isolate_free_page(struct page *page, unsigned int order); 160 extern void memblock_free_pages(struct page *page, unsigned long pfn, 161 unsigned int order); 162 extern void __free_pages_core(struct page *page, unsigned int order); 163 extern void prep_compound_page(struct page *page, unsigned int order); 164 extern void post_alloc_hook(struct page *page, unsigned int order, 165 gfp_t gfp_flags); 166 extern int user_min_free_kbytes; 167 168 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 169 170 /* 171 * in mm/compaction.c 172 */ 173 /* 174 * compact_control is used to track pages being migrated and the free pages 175 * they are being migrated to during memory compaction. The free_pfn starts 176 * at the end of a zone and migrate_pfn begins at the start. Movable pages 177 * are moved to the end of a zone during a compaction run and the run 178 * completes when free_pfn <= migrate_pfn 179 */ 180 struct compact_control { 181 struct list_head freepages; /* List of free pages to migrate to */ 182 struct list_head migratepages; /* List of pages being migrated */ 183 unsigned int nr_freepages; /* Number of isolated free pages */ 184 unsigned int nr_migratepages; /* Number of pages to migrate */ 185 unsigned long free_pfn; /* isolate_freepages search base */ 186 unsigned long migrate_pfn; /* isolate_migratepages search base */ 187 unsigned long fast_start_pfn; /* a pfn to start linear scan from */ 188 struct zone *zone; 189 unsigned long total_migrate_scanned; 190 unsigned long total_free_scanned; 191 unsigned short fast_search_fail;/* failures to use free list searches */ 192 short search_order; /* order to start a fast search at */ 193 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 194 int order; /* order a direct compactor needs */ 195 int migratetype; /* migratetype of direct compactor */ 196 const unsigned int alloc_flags; /* alloc flags of a direct compactor */ 197 const int classzone_idx; /* zone index of a direct compactor */ 198 enum migrate_mode mode; /* Async or sync migration mode */ 199 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 200 bool no_set_skip_hint; /* Don't mark blocks for skipping */ 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 rescan; /* Rescanning the same pageblock */ 206 }; 207 208 /* 209 * Used in direct compaction when a page should be taken from the freelists 210 * immediately when one is created during the free path. 211 */ 212 struct capture_control { 213 struct compact_control *cc; 214 struct page *page; 215 }; 216 217 unsigned long 218 isolate_freepages_range(struct compact_control *cc, 219 unsigned long start_pfn, unsigned long end_pfn); 220 unsigned long 221 isolate_migratepages_range(struct compact_control *cc, 222 unsigned long low_pfn, unsigned long end_pfn); 223 int find_suitable_fallback(struct free_area *area, unsigned int order, 224 int migratetype, bool only_stealable, bool *can_steal); 225 226 #endif 227 228 /* 229 * This function returns the order of a free page in the buddy system. In 230 * general, page_zone(page)->lock must be held by the caller to prevent the 231 * page from being allocated in parallel and returning garbage as the order. 232 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 233 * page cannot be allocated or merged in parallel. Alternatively, it must 234 * handle invalid values gracefully, and use page_order_unsafe() below. 235 */ 236 static inline unsigned int page_order(struct page *page) 237 { 238 /* PageBuddy() must be checked by the caller */ 239 return page_private(page); 240 } 241 242 /* 243 * Like page_order(), but for callers who cannot afford to hold the zone lock. 244 * PageBuddy() should be checked first by the caller to minimize race window, 245 * and invalid values must be handled gracefully. 246 * 247 * READ_ONCE is used so that if the caller assigns the result into a local 248 * variable and e.g. tests it for valid range before using, the compiler cannot 249 * decide to remove the variable and inline the page_private(page) multiple 250 * times, potentially observing different values in the tests and the actual 251 * use of the result. 252 */ 253 #define page_order_unsafe(page) READ_ONCE(page_private(page)) 254 255 static inline bool is_cow_mapping(vm_flags_t flags) 256 { 257 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 258 } 259 260 /* 261 * These three helpers classifies VMAs for virtual memory accounting. 262 */ 263 264 /* 265 * Executable code area - executable, not writable, not stack 266 */ 267 static inline bool is_exec_mapping(vm_flags_t flags) 268 { 269 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; 270 } 271 272 /* 273 * Stack area - atomatically grows in one direction 274 * 275 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous: 276 * do_mmap() forbids all other combinations. 277 */ 278 static inline bool is_stack_mapping(vm_flags_t flags) 279 { 280 return (flags & VM_STACK) == VM_STACK; 281 } 282 283 /* 284 * Data area - private, writable, not stack 285 */ 286 static inline bool is_data_mapping(vm_flags_t flags) 287 { 288 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; 289 } 290 291 /* mm/util.c */ 292 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 293 struct vm_area_struct *prev); 294 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma); 295 296 #ifdef CONFIG_MMU 297 extern long populate_vma_page_range(struct vm_area_struct *vma, 298 unsigned long start, unsigned long end, int *nonblocking); 299 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 300 unsigned long start, unsigned long end); 301 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 302 { 303 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 304 } 305 306 /* 307 * must be called with vma's mmap_sem held for read or write, and page locked. 308 */ 309 extern void mlock_vma_page(struct page *page); 310 extern unsigned int munlock_vma_page(struct page *page); 311 312 /* 313 * Clear the page's PageMlocked(). This can be useful in a situation where 314 * we want to unconditionally remove a page from the pagecache -- e.g., 315 * on truncation or freeing. 316 * 317 * It is legal to call this function for any page, mlocked or not. 318 * If called for a page that is still mapped by mlocked vmas, all we do 319 * is revert to lazy LRU behaviour -- semantics are not broken. 320 */ 321 extern void clear_page_mlock(struct page *page); 322 323 /* 324 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page() 325 * (because that does not go through the full procedure of migration ptes): 326 * to migrate the Mlocked page flag; update statistics. 327 */ 328 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 329 { 330 if (TestClearPageMlocked(page)) { 331 int nr_pages = hpage_nr_pages(page); 332 333 /* Holding pmd lock, no change in irq context: __mod is safe */ 334 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); 335 SetPageMlocked(newpage); 336 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages); 337 } 338 } 339 340 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 341 342 /* 343 * At what user virtual address is page expected in @vma? 344 */ 345 static inline unsigned long 346 __vma_address(struct page *page, struct vm_area_struct *vma) 347 { 348 pgoff_t pgoff = page_to_pgoff(page); 349 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 350 } 351 352 static inline unsigned long 353 vma_address(struct page *page, struct vm_area_struct *vma) 354 { 355 unsigned long start, end; 356 357 start = __vma_address(page, vma); 358 end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1); 359 360 /* page should be within @vma mapping range */ 361 VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma); 362 363 return max(start, vma->vm_start); 364 } 365 366 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, 367 struct file *fpin) 368 { 369 int flags = vmf->flags; 370 371 if (fpin) 372 return fpin; 373 374 /* 375 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or 376 * anything, so we only pin the file and drop the mmap_sem if only 377 * FAULT_FLAG_ALLOW_RETRY is set. 378 */ 379 if ((flags & (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT)) == 380 FAULT_FLAG_ALLOW_RETRY) { 381 fpin = get_file(vmf->vma->vm_file); 382 up_read(&vmf->vma->vm_mm->mmap_sem); 383 } 384 return fpin; 385 } 386 387 #else /* !CONFIG_MMU */ 388 static inline void clear_page_mlock(struct page *page) { } 389 static inline void mlock_vma_page(struct page *page) { } 390 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 391 392 #endif /* !CONFIG_MMU */ 393 394 /* 395 * Return the mem_map entry representing the 'offset' subpage within 396 * the maximally aligned gigantic page 'base'. Handle any discontiguity 397 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 398 */ 399 static inline struct page *mem_map_offset(struct page *base, int offset) 400 { 401 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 402 return nth_page(base, offset); 403 return base + offset; 404 } 405 406 /* 407 * Iterator over all subpages within the maximally aligned gigantic 408 * page 'base'. Handle any discontiguity in the mem_map. 409 */ 410 static inline struct page *mem_map_next(struct page *iter, 411 struct page *base, int offset) 412 { 413 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 414 unsigned long pfn = page_to_pfn(base) + offset; 415 if (!pfn_valid(pfn)) 416 return NULL; 417 return pfn_to_page(pfn); 418 } 419 return iter + 1; 420 } 421 422 /* Memory initialisation debug and verification */ 423 enum mminit_level { 424 MMINIT_WARNING, 425 MMINIT_VERIFY, 426 MMINIT_TRACE 427 }; 428 429 #ifdef CONFIG_DEBUG_MEMORY_INIT 430 431 extern int mminit_loglevel; 432 433 #define mminit_dprintk(level, prefix, fmt, arg...) \ 434 do { \ 435 if (level < mminit_loglevel) { \ 436 if (level <= MMINIT_WARNING) \ 437 pr_warn("mminit::" prefix " " fmt, ##arg); \ 438 else \ 439 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 440 } \ 441 } while (0) 442 443 extern void mminit_verify_pageflags_layout(void); 444 extern void mminit_verify_zonelist(void); 445 #else 446 447 static inline void mminit_dprintk(enum mminit_level level, 448 const char *prefix, const char *fmt, ...) 449 { 450 } 451 452 static inline void mminit_verify_pageflags_layout(void) 453 { 454 } 455 456 static inline void mminit_verify_zonelist(void) 457 { 458 } 459 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 460 461 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 462 #if defined(CONFIG_SPARSEMEM) 463 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 464 unsigned long *end_pfn); 465 #else 466 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 467 unsigned long *end_pfn) 468 { 469 } 470 #endif /* CONFIG_SPARSEMEM */ 471 472 #define NODE_RECLAIM_NOSCAN -2 473 #define NODE_RECLAIM_FULL -1 474 #define NODE_RECLAIM_SOME 0 475 #define NODE_RECLAIM_SUCCESS 1 476 477 #ifdef CONFIG_NUMA 478 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); 479 #else 480 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, 481 unsigned int order) 482 { 483 return NODE_RECLAIM_NOSCAN; 484 } 485 #endif 486 487 extern int hwpoison_filter(struct page *p); 488 489 extern u32 hwpoison_filter_dev_major; 490 extern u32 hwpoison_filter_dev_minor; 491 extern u64 hwpoison_filter_flags_mask; 492 extern u64 hwpoison_filter_flags_value; 493 extern u64 hwpoison_filter_memcg; 494 extern u32 hwpoison_filter_enable; 495 496 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 497 unsigned long, unsigned long, 498 unsigned long, unsigned long); 499 500 extern void set_pageblock_order(void); 501 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 502 struct list_head *page_list); 503 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 504 #define ALLOC_WMARK_MIN WMARK_MIN 505 #define ALLOC_WMARK_LOW WMARK_LOW 506 #define ALLOC_WMARK_HIGH WMARK_HIGH 507 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 508 509 /* Mask to get the watermark bits */ 510 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 511 512 /* 513 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we 514 * cannot assume a reduced access to memory reserves is sufficient for 515 * !MMU 516 */ 517 #ifdef CONFIG_MMU 518 #define ALLOC_OOM 0x08 519 #else 520 #define ALLOC_OOM ALLOC_NO_WATERMARKS 521 #endif 522 523 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 524 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 525 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 526 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 527 #ifdef CONFIG_ZONE_DMA32 528 #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */ 529 #else 530 #define ALLOC_NOFRAGMENT 0x0 531 #endif 532 #define ALLOC_KSWAPD 0x200 /* allow waking of kswapd */ 533 534 enum ttu_flags; 535 struct tlbflush_unmap_batch; 536 537 538 /* 539 * only for MM internal work items which do not depend on 540 * any allocations or locks which might depend on allocations 541 */ 542 extern struct workqueue_struct *mm_percpu_wq; 543 544 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 545 void try_to_unmap_flush(void); 546 void try_to_unmap_flush_dirty(void); 547 void flush_tlb_batched_pending(struct mm_struct *mm); 548 #else 549 static inline void try_to_unmap_flush(void) 550 { 551 } 552 static inline void try_to_unmap_flush_dirty(void) 553 { 554 } 555 static inline void flush_tlb_batched_pending(struct mm_struct *mm) 556 { 557 } 558 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 559 560 extern const struct trace_print_flags pageflag_names[]; 561 extern const struct trace_print_flags vmaflag_names[]; 562 extern const struct trace_print_flags gfpflag_names[]; 563 564 static inline bool is_migrate_highatomic(enum migratetype migratetype) 565 { 566 return migratetype == MIGRATE_HIGHATOMIC; 567 } 568 569 static inline bool is_migrate_highatomic_page(struct page *page) 570 { 571 return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC; 572 } 573 574 void setup_zone_pageset(struct zone *zone); 575 extern struct page *alloc_new_node_page(struct page *page, unsigned long node); 576 #endif /* __MM_INTERNAL_H */ 577