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 extern void zone_pcp_update(struct zone *zone); 169 extern void zone_pcp_reset(struct zone *zone); 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 unsigned int nr_freepages; /* Number of isolated free pages */ 187 unsigned int nr_migratepages; /* Number of pages to migrate */ 188 unsigned long free_pfn; /* isolate_freepages search base */ 189 unsigned long migrate_pfn; /* isolate_migratepages search base */ 190 unsigned long fast_start_pfn; /* a pfn to start linear scan from */ 191 struct zone *zone; 192 unsigned long total_migrate_scanned; 193 unsigned long total_free_scanned; 194 unsigned short fast_search_fail;/* failures to use free list searches */ 195 short search_order; /* order to start a fast search at */ 196 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 197 int order; /* order a direct compactor needs */ 198 int migratetype; /* migratetype of direct compactor */ 199 const unsigned int alloc_flags; /* alloc flags of a direct compactor */ 200 const int classzone_idx; /* zone index of a direct compactor */ 201 enum migrate_mode mode; /* Async or sync migration mode */ 202 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 203 bool no_set_skip_hint; /* Don't mark blocks for skipping */ 204 bool ignore_block_suitable; /* Scan blocks considered unsuitable */ 205 bool direct_compaction; /* False from kcompactd or /proc/... */ 206 bool whole_zone; /* Whole zone should/has been scanned */ 207 bool contended; /* Signal lock or sched contention */ 208 bool rescan; /* Rescanning the same pageblock */ 209 }; 210 211 /* 212 * Used in direct compaction when a page should be taken from the freelists 213 * immediately when one is created during the free path. 214 */ 215 struct capture_control { 216 struct compact_control *cc; 217 struct page *page; 218 }; 219 220 unsigned long 221 isolate_freepages_range(struct compact_control *cc, 222 unsigned long start_pfn, unsigned long end_pfn); 223 unsigned long 224 isolate_migratepages_range(struct compact_control *cc, 225 unsigned long low_pfn, unsigned long end_pfn); 226 int find_suitable_fallback(struct free_area *area, unsigned int order, 227 int migratetype, bool only_stealable, bool *can_steal); 228 229 #endif 230 231 /* 232 * This function returns the order of a free page in the buddy system. In 233 * general, page_zone(page)->lock must be held by the caller to prevent the 234 * page from being allocated in parallel and returning garbage as the order. 235 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 236 * page cannot be allocated or merged in parallel. Alternatively, it must 237 * handle invalid values gracefully, and use page_order_unsafe() below. 238 */ 239 static inline unsigned int page_order(struct page *page) 240 { 241 /* PageBuddy() must be checked by the caller */ 242 return page_private(page); 243 } 244 245 /* 246 * Like page_order(), but for callers who cannot afford to hold the zone lock. 247 * PageBuddy() should be checked first by the caller to minimize race window, 248 * and invalid values must be handled gracefully. 249 * 250 * READ_ONCE is used so that if the caller assigns the result into a local 251 * variable and e.g. tests it for valid range before using, the compiler cannot 252 * decide to remove the variable and inline the page_private(page) multiple 253 * times, potentially observing different values in the tests and the actual 254 * use of the result. 255 */ 256 #define page_order_unsafe(page) READ_ONCE(page_private(page)) 257 258 static inline bool is_cow_mapping(vm_flags_t flags) 259 { 260 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 261 } 262 263 /* 264 * These three helpers classifies VMAs for virtual memory accounting. 265 */ 266 267 /* 268 * Executable code area - executable, not writable, not stack 269 */ 270 static inline bool is_exec_mapping(vm_flags_t flags) 271 { 272 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; 273 } 274 275 /* 276 * Stack area - atomatically grows in one direction 277 * 278 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous: 279 * do_mmap() forbids all other combinations. 280 */ 281 static inline bool is_stack_mapping(vm_flags_t flags) 282 { 283 return (flags & VM_STACK) == VM_STACK; 284 } 285 286 /* 287 * Data area - private, writable, not stack 288 */ 289 static inline bool is_data_mapping(vm_flags_t flags) 290 { 291 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; 292 } 293 294 /* mm/util.c */ 295 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 296 struct vm_area_struct *prev); 297 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma); 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 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, 370 struct file *fpin) 371 { 372 int flags = vmf->flags; 373 374 if (fpin) 375 return fpin; 376 377 /* 378 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or 379 * anything, so we only pin the file and drop the mmap_sem if only 380 * FAULT_FLAG_ALLOW_RETRY is set. 381 */ 382 if ((flags & (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT)) == 383 FAULT_FLAG_ALLOW_RETRY) { 384 fpin = get_file(vmf->vma->vm_file); 385 up_read(&vmf->vma->vm_mm->mmap_sem); 386 } 387 return fpin; 388 } 389 390 #else /* !CONFIG_MMU */ 391 static inline void clear_page_mlock(struct page *page) { } 392 static inline void mlock_vma_page(struct page *page) { } 393 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 394 395 #endif /* !CONFIG_MMU */ 396 397 /* 398 * Return the mem_map entry representing the 'offset' subpage within 399 * the maximally aligned gigantic page 'base'. Handle any discontiguity 400 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 401 */ 402 static inline struct page *mem_map_offset(struct page *base, int offset) 403 { 404 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 405 return nth_page(base, offset); 406 return base + offset; 407 } 408 409 /* 410 * Iterator over all subpages within the maximally aligned gigantic 411 * page 'base'. Handle any discontiguity in the mem_map. 412 */ 413 static inline struct page *mem_map_next(struct page *iter, 414 struct page *base, int offset) 415 { 416 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 417 unsigned long pfn = page_to_pfn(base) + offset; 418 if (!pfn_valid(pfn)) 419 return NULL; 420 return pfn_to_page(pfn); 421 } 422 return iter + 1; 423 } 424 425 /* Memory initialisation debug and verification */ 426 enum mminit_level { 427 MMINIT_WARNING, 428 MMINIT_VERIFY, 429 MMINIT_TRACE 430 }; 431 432 #ifdef CONFIG_DEBUG_MEMORY_INIT 433 434 extern int mminit_loglevel; 435 436 #define mminit_dprintk(level, prefix, fmt, arg...) \ 437 do { \ 438 if (level < mminit_loglevel) { \ 439 if (level <= MMINIT_WARNING) \ 440 pr_warn("mminit::" prefix " " fmt, ##arg); \ 441 else \ 442 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 443 } \ 444 } while (0) 445 446 extern void mminit_verify_pageflags_layout(void); 447 extern void mminit_verify_zonelist(void); 448 #else 449 450 static inline void mminit_dprintk(enum mminit_level level, 451 const char *prefix, const char *fmt, ...) 452 { 453 } 454 455 static inline void mminit_verify_pageflags_layout(void) 456 { 457 } 458 459 static inline void mminit_verify_zonelist(void) 460 { 461 } 462 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 463 464 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 465 #if defined(CONFIG_SPARSEMEM) 466 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 467 unsigned long *end_pfn); 468 #else 469 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 470 unsigned long *end_pfn) 471 { 472 } 473 #endif /* CONFIG_SPARSEMEM */ 474 475 #define NODE_RECLAIM_NOSCAN -2 476 #define NODE_RECLAIM_FULL -1 477 #define NODE_RECLAIM_SOME 0 478 #define NODE_RECLAIM_SUCCESS 1 479 480 #ifdef CONFIG_NUMA 481 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); 482 #else 483 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, 484 unsigned int order) 485 { 486 return NODE_RECLAIM_NOSCAN; 487 } 488 #endif 489 490 extern int hwpoison_filter(struct page *p); 491 492 extern u32 hwpoison_filter_dev_major; 493 extern u32 hwpoison_filter_dev_minor; 494 extern u64 hwpoison_filter_flags_mask; 495 extern u64 hwpoison_filter_flags_value; 496 extern u64 hwpoison_filter_memcg; 497 extern u32 hwpoison_filter_enable; 498 499 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 500 unsigned long, unsigned long, 501 unsigned long, unsigned long); 502 503 extern void set_pageblock_order(void); 504 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 505 struct list_head *page_list); 506 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 507 #define ALLOC_WMARK_MIN WMARK_MIN 508 #define ALLOC_WMARK_LOW WMARK_LOW 509 #define ALLOC_WMARK_HIGH WMARK_HIGH 510 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 511 512 /* Mask to get the watermark bits */ 513 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 514 515 /* 516 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we 517 * cannot assume a reduced access to memory reserves is sufficient for 518 * !MMU 519 */ 520 #ifdef CONFIG_MMU 521 #define ALLOC_OOM 0x08 522 #else 523 #define ALLOC_OOM ALLOC_NO_WATERMARKS 524 #endif 525 526 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 527 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 528 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 529 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 530 #ifdef CONFIG_ZONE_DMA32 531 #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */ 532 #else 533 #define ALLOC_NOFRAGMENT 0x0 534 #endif 535 #define ALLOC_KSWAPD 0x200 /* allow waking of kswapd */ 536 537 enum ttu_flags; 538 struct tlbflush_unmap_batch; 539 540 541 /* 542 * only for MM internal work items which do not depend on 543 * any allocations or locks which might depend on allocations 544 */ 545 extern struct workqueue_struct *mm_percpu_wq; 546 547 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 548 void try_to_unmap_flush(void); 549 void try_to_unmap_flush_dirty(void); 550 void flush_tlb_batched_pending(struct mm_struct *mm); 551 #else 552 static inline void try_to_unmap_flush(void) 553 { 554 } 555 static inline void try_to_unmap_flush_dirty(void) 556 { 557 } 558 static inline void flush_tlb_batched_pending(struct mm_struct *mm) 559 { 560 } 561 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 562 563 extern const struct trace_print_flags pageflag_names[]; 564 extern const struct trace_print_flags vmaflag_names[]; 565 extern const struct trace_print_flags gfpflag_names[]; 566 567 static inline bool is_migrate_highatomic(enum migratetype migratetype) 568 { 569 return migratetype == MIGRATE_HIGHATOMIC; 570 } 571 572 static inline bool is_migrate_highatomic_page(struct page *page) 573 { 574 return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC; 575 } 576 577 void setup_zone_pageset(struct zone *zone); 578 extern struct page *alloc_new_node_page(struct page *page, unsigned long node); 579 #endif /* __MM_INTERNAL_H */ 580