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/rmap.h> 14 #include <linux/swap.h> 15 #include <linux/swapops.h> 16 #include <linux/tracepoint-defs.h> 17 18 struct folio_batch; 19 20 /* 21 * The set of flags that only affect watermark checking and reclaim 22 * behaviour. This is used by the MM to obey the caller constraints 23 * about IO, FS and watermark checking while ignoring placement 24 * hints such as HIGHMEM usage. 25 */ 26 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\ 27 __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\ 28 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\ 29 __GFP_NOLOCKDEP) 30 31 /* The GFP flags allowed during early boot */ 32 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS)) 33 34 /* Control allocation cpuset and node placement constraints */ 35 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE) 36 37 /* Do not use these with a slab allocator */ 38 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) 39 40 /* 41 * Different from WARN_ON_ONCE(), no warning will be issued 42 * when we specify __GFP_NOWARN. 43 */ 44 #define WARN_ON_ONCE_GFP(cond, gfp) ({ \ 45 static bool __section(".data.once") __warned; \ 46 int __ret_warn_once = !!(cond); \ 47 \ 48 if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \ 49 __warned = true; \ 50 WARN_ON(1); \ 51 } \ 52 unlikely(__ret_warn_once); \ 53 }) 54 55 void page_writeback_init(void); 56 57 /* 58 * If a 16GB hugetlb folio were mapped by PTEs of all of its 4kB pages, 59 * its nr_pages_mapped would be 0x400000: choose the ENTIRELY_MAPPED bit 60 * above that range, instead of 2*(PMD_SIZE/PAGE_SIZE). Hugetlb currently 61 * leaves nr_pages_mapped at 0, but avoid surprise if it participates later. 62 */ 63 #define ENTIRELY_MAPPED 0x800000 64 #define FOLIO_PAGES_MAPPED (ENTIRELY_MAPPED - 1) 65 66 /* 67 * Flags passed to __show_mem() and show_free_areas() to suppress output in 68 * various contexts. 69 */ 70 #define SHOW_MEM_FILTER_NODES (0x0001u) /* disallowed nodes */ 71 72 /* 73 * How many individual pages have an elevated _mapcount. Excludes 74 * the folio's entire_mapcount. 75 * 76 * Don't use this function outside of debugging code. 77 */ 78 static inline int folio_nr_pages_mapped(const struct folio *folio) 79 { 80 return atomic_read(&folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED; 81 } 82 83 /* 84 * Retrieve the first entry of a folio based on a provided entry within the 85 * folio. We cannot rely on folio->swap as there is no guarantee that it has 86 * been initialized. Used for calling arch_swap_restore() 87 */ 88 static inline swp_entry_t folio_swap(swp_entry_t entry, 89 const struct folio *folio) 90 { 91 swp_entry_t swap = { 92 .val = ALIGN_DOWN(entry.val, folio_nr_pages(folio)), 93 }; 94 95 return swap; 96 } 97 98 static inline void *folio_raw_mapping(const struct folio *folio) 99 { 100 unsigned long mapping = (unsigned long)folio->mapping; 101 102 return (void *)(mapping & ~PAGE_MAPPING_FLAGS); 103 } 104 105 #ifdef CONFIG_MMU 106 107 /* Flags for folio_pte_batch(). */ 108 typedef int __bitwise fpb_t; 109 110 /* Compare PTEs after pte_mkclean(), ignoring the dirty bit. */ 111 #define FPB_IGNORE_DIRTY ((__force fpb_t)BIT(0)) 112 113 /* Compare PTEs after pte_clear_soft_dirty(), ignoring the soft-dirty bit. */ 114 #define FPB_IGNORE_SOFT_DIRTY ((__force fpb_t)BIT(1)) 115 116 static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags) 117 { 118 if (flags & FPB_IGNORE_DIRTY) 119 pte = pte_mkclean(pte); 120 if (likely(flags & FPB_IGNORE_SOFT_DIRTY)) 121 pte = pte_clear_soft_dirty(pte); 122 return pte_wrprotect(pte_mkold(pte)); 123 } 124 125 /** 126 * folio_pte_batch - detect a PTE batch for a large folio 127 * @folio: The large folio to detect a PTE batch for. 128 * @addr: The user virtual address the first page is mapped at. 129 * @start_ptep: Page table pointer for the first entry. 130 * @pte: Page table entry for the first page. 131 * @max_nr: The maximum number of table entries to consider. 132 * @flags: Flags to modify the PTE batch semantics. 133 * @any_writable: Optional pointer to indicate whether any entry except the 134 * first one is writable. 135 * @any_young: Optional pointer to indicate whether any entry except the 136 * first one is young. 137 * @any_dirty: Optional pointer to indicate whether any entry except the 138 * first one is dirty. 139 * 140 * Detect a PTE batch: consecutive (present) PTEs that map consecutive 141 * pages of the same large folio. 142 * 143 * All PTEs inside a PTE batch have the same PTE bits set, excluding the PFN, 144 * the accessed bit, writable bit, dirty bit (with FPB_IGNORE_DIRTY) and 145 * soft-dirty bit (with FPB_IGNORE_SOFT_DIRTY). 146 * 147 * start_ptep must map any page of the folio. max_nr must be at least one and 148 * must be limited by the caller so scanning cannot exceed a single page table. 149 * 150 * Return: the number of table entries in the batch. 151 */ 152 static inline int folio_pte_batch(struct folio *folio, unsigned long addr, 153 pte_t *start_ptep, pte_t pte, int max_nr, fpb_t flags, 154 bool *any_writable, bool *any_young, bool *any_dirty) 155 { 156 unsigned long folio_end_pfn = folio_pfn(folio) + folio_nr_pages(folio); 157 const pte_t *end_ptep = start_ptep + max_nr; 158 pte_t expected_pte, *ptep; 159 bool writable, young, dirty; 160 int nr; 161 162 if (any_writable) 163 *any_writable = false; 164 if (any_young) 165 *any_young = false; 166 if (any_dirty) 167 *any_dirty = false; 168 169 VM_WARN_ON_FOLIO(!pte_present(pte), folio); 170 VM_WARN_ON_FOLIO(!folio_test_large(folio) || max_nr < 1, folio); 171 VM_WARN_ON_FOLIO(page_folio(pfn_to_page(pte_pfn(pte))) != folio, folio); 172 173 nr = pte_batch_hint(start_ptep, pte); 174 expected_pte = __pte_batch_clear_ignored(pte_advance_pfn(pte, nr), flags); 175 ptep = start_ptep + nr; 176 177 while (ptep < end_ptep) { 178 pte = ptep_get(ptep); 179 if (any_writable) 180 writable = !!pte_write(pte); 181 if (any_young) 182 young = !!pte_young(pte); 183 if (any_dirty) 184 dirty = !!pte_dirty(pte); 185 pte = __pte_batch_clear_ignored(pte, flags); 186 187 if (!pte_same(pte, expected_pte)) 188 break; 189 190 /* 191 * Stop immediately once we reached the end of the folio. In 192 * corner cases the next PFN might fall into a different 193 * folio. 194 */ 195 if (pte_pfn(pte) >= folio_end_pfn) 196 break; 197 198 if (any_writable) 199 *any_writable |= writable; 200 if (any_young) 201 *any_young |= young; 202 if (any_dirty) 203 *any_dirty |= dirty; 204 205 nr = pte_batch_hint(ptep, pte); 206 expected_pte = pte_advance_pfn(expected_pte, nr); 207 ptep += nr; 208 } 209 210 return min(ptep - start_ptep, max_nr); 211 } 212 213 /** 214 * pte_next_swp_offset - Increment the swap entry offset field of a swap pte. 215 * @pte: The initial pte state; is_swap_pte(pte) must be true and 216 * non_swap_entry() must be false. 217 * 218 * Increments the swap offset, while maintaining all other fields, including 219 * swap type, and any swp pte bits. The resulting pte is returned. 220 */ 221 static inline pte_t pte_next_swp_offset(pte_t pte) 222 { 223 swp_entry_t entry = pte_to_swp_entry(pte); 224 pte_t new = __swp_entry_to_pte(__swp_entry(swp_type(entry), 225 (swp_offset(entry) + 1))); 226 227 if (pte_swp_soft_dirty(pte)) 228 new = pte_swp_mksoft_dirty(new); 229 if (pte_swp_exclusive(pte)) 230 new = pte_swp_mkexclusive(new); 231 if (pte_swp_uffd_wp(pte)) 232 new = pte_swp_mkuffd_wp(new); 233 234 return new; 235 } 236 237 /** 238 * swap_pte_batch - detect a PTE batch for a set of contiguous swap entries 239 * @start_ptep: Page table pointer for the first entry. 240 * @max_nr: The maximum number of table entries to consider. 241 * @pte: Page table entry for the first entry. 242 * 243 * Detect a batch of contiguous swap entries: consecutive (non-present) PTEs 244 * containing swap entries all with consecutive offsets and targeting the same 245 * swap type, all with matching swp pte bits. 246 * 247 * max_nr must be at least one and must be limited by the caller so scanning 248 * cannot exceed a single page table. 249 * 250 * Return: the number of table entries in the batch. 251 */ 252 static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte) 253 { 254 pte_t expected_pte = pte_next_swp_offset(pte); 255 const pte_t *end_ptep = start_ptep + max_nr; 256 pte_t *ptep = start_ptep + 1; 257 258 VM_WARN_ON(max_nr < 1); 259 VM_WARN_ON(!is_swap_pte(pte)); 260 VM_WARN_ON(non_swap_entry(pte_to_swp_entry(pte))); 261 262 while (ptep < end_ptep) { 263 pte = ptep_get(ptep); 264 265 if (!pte_same(pte, expected_pte)) 266 break; 267 268 expected_pte = pte_next_swp_offset(expected_pte); 269 ptep++; 270 } 271 272 return ptep - start_ptep; 273 } 274 #endif /* CONFIG_MMU */ 275 276 void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio, 277 int nr_throttled); 278 static inline void acct_reclaim_writeback(struct folio *folio) 279 { 280 pg_data_t *pgdat = folio_pgdat(folio); 281 int nr_throttled = atomic_read(&pgdat->nr_writeback_throttled); 282 283 if (nr_throttled) 284 __acct_reclaim_writeback(pgdat, folio, nr_throttled); 285 } 286 287 static inline void wake_throttle_isolated(pg_data_t *pgdat) 288 { 289 wait_queue_head_t *wqh; 290 291 wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED]; 292 if (waitqueue_active(wqh)) 293 wake_up(wqh); 294 } 295 296 vm_fault_t vmf_anon_prepare(struct vm_fault *vmf); 297 vm_fault_t do_swap_page(struct vm_fault *vmf); 298 void folio_rotate_reclaimable(struct folio *folio); 299 bool __folio_end_writeback(struct folio *folio); 300 void deactivate_file_folio(struct folio *folio); 301 void folio_activate(struct folio *folio); 302 303 void free_pgtables(struct mmu_gather *tlb, struct ma_state *mas, 304 struct vm_area_struct *start_vma, unsigned long floor, 305 unsigned long ceiling, bool mm_wr_locked); 306 void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte); 307 308 struct zap_details; 309 void unmap_page_range(struct mmu_gather *tlb, 310 struct vm_area_struct *vma, 311 unsigned long addr, unsigned long end, 312 struct zap_details *details); 313 314 void page_cache_ra_order(struct readahead_control *, struct file_ra_state *, 315 unsigned int order); 316 void force_page_cache_ra(struct readahead_control *, unsigned long nr); 317 static inline void force_page_cache_readahead(struct address_space *mapping, 318 struct file *file, pgoff_t index, unsigned long nr_to_read) 319 { 320 DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index); 321 force_page_cache_ra(&ractl, nr_to_read); 322 } 323 324 unsigned find_lock_entries(struct address_space *mapping, pgoff_t *start, 325 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices); 326 unsigned find_get_entries(struct address_space *mapping, pgoff_t *start, 327 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices); 328 void filemap_free_folio(struct address_space *mapping, struct folio *folio); 329 int truncate_inode_folio(struct address_space *mapping, struct folio *folio); 330 bool truncate_inode_partial_folio(struct folio *folio, loff_t start, 331 loff_t end); 332 long mapping_evict_folio(struct address_space *mapping, struct folio *folio); 333 unsigned long mapping_try_invalidate(struct address_space *mapping, 334 pgoff_t start, pgoff_t end, unsigned long *nr_failed); 335 336 /** 337 * folio_evictable - Test whether a folio is evictable. 338 * @folio: The folio to test. 339 * 340 * Test whether @folio is evictable -- i.e., should be placed on 341 * active/inactive lists vs unevictable list. 342 * 343 * Reasons folio might not be evictable: 344 * 1. folio's mapping marked unevictable 345 * 2. One of the pages in the folio is part of an mlocked VMA 346 */ 347 static inline bool folio_evictable(struct folio *folio) 348 { 349 bool ret; 350 351 /* Prevent address_space of inode and swap cache from being freed */ 352 rcu_read_lock(); 353 ret = !mapping_unevictable(folio_mapping(folio)) && 354 !folio_test_mlocked(folio); 355 rcu_read_unlock(); 356 return ret; 357 } 358 359 /* 360 * Turn a non-refcounted page (->_refcount == 0) into refcounted with 361 * a count of one. 362 */ 363 static inline void set_page_refcounted(struct page *page) 364 { 365 VM_BUG_ON_PAGE(PageTail(page), page); 366 VM_BUG_ON_PAGE(page_ref_count(page), page); 367 set_page_count(page, 1); 368 } 369 370 /* 371 * Return true if a folio needs ->release_folio() calling upon it. 372 */ 373 static inline bool folio_needs_release(struct folio *folio) 374 { 375 struct address_space *mapping = folio_mapping(folio); 376 377 return folio_has_private(folio) || 378 (mapping && mapping_release_always(mapping)); 379 } 380 381 extern unsigned long highest_memmap_pfn; 382 383 /* 384 * Maximum number of reclaim retries without progress before the OOM 385 * killer is consider the only way forward. 386 */ 387 #define MAX_RECLAIM_RETRIES 16 388 389 /* 390 * in mm/vmscan.c: 391 */ 392 bool isolate_lru_page(struct page *page); 393 bool folio_isolate_lru(struct folio *folio); 394 void putback_lru_page(struct page *page); 395 void folio_putback_lru(struct folio *folio); 396 extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason); 397 398 /* 399 * in mm/rmap.c: 400 */ 401 pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 402 403 /* 404 * in mm/page_alloc.c 405 */ 406 #define K(x) ((x) << (PAGE_SHIFT-10)) 407 408 extern char * const zone_names[MAX_NR_ZONES]; 409 410 /* perform sanity checks on struct pages being allocated or freed */ 411 DECLARE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled); 412 413 extern int min_free_kbytes; 414 415 void setup_per_zone_wmarks(void); 416 void calculate_min_free_kbytes(void); 417 int __meminit init_per_zone_wmark_min(void); 418 void page_alloc_sysctl_init(void); 419 420 /* 421 * Structure for holding the mostly immutable allocation parameters passed 422 * between functions involved in allocations, including the alloc_pages* 423 * family of functions. 424 * 425 * nodemask, migratetype and highest_zoneidx are initialized only once in 426 * __alloc_pages() and then never change. 427 * 428 * zonelist, preferred_zone and highest_zoneidx are set first in 429 * __alloc_pages() for the fast path, and might be later changed 430 * in __alloc_pages_slowpath(). All other functions pass the whole structure 431 * by a const pointer. 432 */ 433 struct alloc_context { 434 struct zonelist *zonelist; 435 nodemask_t *nodemask; 436 struct zoneref *preferred_zoneref; 437 int migratetype; 438 439 /* 440 * highest_zoneidx represents highest usable zone index of 441 * the allocation request. Due to the nature of the zone, 442 * memory on lower zone than the highest_zoneidx will be 443 * protected by lowmem_reserve[highest_zoneidx]. 444 * 445 * highest_zoneidx is also used by reclaim/compaction to limit 446 * the target zone since higher zone than this index cannot be 447 * usable for this allocation request. 448 */ 449 enum zone_type highest_zoneidx; 450 bool spread_dirty_pages; 451 }; 452 453 /* 454 * This function returns the order of a free page in the buddy system. In 455 * general, page_zone(page)->lock must be held by the caller to prevent the 456 * page from being allocated in parallel and returning garbage as the order. 457 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 458 * page cannot be allocated or merged in parallel. Alternatively, it must 459 * handle invalid values gracefully, and use buddy_order_unsafe() below. 460 */ 461 static inline unsigned int buddy_order(struct page *page) 462 { 463 /* PageBuddy() must be checked by the caller */ 464 return page_private(page); 465 } 466 467 /* 468 * Like buddy_order(), but for callers who cannot afford to hold the zone lock. 469 * PageBuddy() should be checked first by the caller to minimize race window, 470 * and invalid values must be handled gracefully. 471 * 472 * READ_ONCE is used so that if the caller assigns the result into a local 473 * variable and e.g. tests it for valid range before using, the compiler cannot 474 * decide to remove the variable and inline the page_private(page) multiple 475 * times, potentially observing different values in the tests and the actual 476 * use of the result. 477 */ 478 #define buddy_order_unsafe(page) READ_ONCE(page_private(page)) 479 480 /* 481 * This function checks whether a page is free && is the buddy 482 * we can coalesce a page and its buddy if 483 * (a) the buddy is not in a hole (check before calling!) && 484 * (b) the buddy is in the buddy system && 485 * (c) a page and its buddy have the same order && 486 * (d) a page and its buddy are in the same zone. 487 * 488 * For recording whether a page is in the buddy system, we set PageBuddy. 489 * Setting, clearing, and testing PageBuddy is serialized by zone->lock. 490 * 491 * For recording page's order, we use page_private(page). 492 */ 493 static inline bool page_is_buddy(struct page *page, struct page *buddy, 494 unsigned int order) 495 { 496 if (!page_is_guard(buddy) && !PageBuddy(buddy)) 497 return false; 498 499 if (buddy_order(buddy) != order) 500 return false; 501 502 /* 503 * zone check is done late to avoid uselessly calculating 504 * zone/node ids for pages that could never merge. 505 */ 506 if (page_zone_id(page) != page_zone_id(buddy)) 507 return false; 508 509 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); 510 511 return true; 512 } 513 514 /* 515 * Locate the struct page for both the matching buddy in our 516 * pair (buddy1) and the combined O(n+1) page they form (page). 517 * 518 * 1) Any buddy B1 will have an order O twin B2 which satisfies 519 * the following equation: 520 * B2 = B1 ^ (1 << O) 521 * For example, if the starting buddy (buddy2) is #8 its order 522 * 1 buddy is #10: 523 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 524 * 525 * 2) Any buddy B will have an order O+1 parent P which 526 * satisfies the following equation: 527 * P = B & ~(1 << O) 528 * 529 * Assumption: *_mem_map is contiguous at least up to MAX_PAGE_ORDER 530 */ 531 static inline unsigned long 532 __find_buddy_pfn(unsigned long page_pfn, unsigned int order) 533 { 534 return page_pfn ^ (1 << order); 535 } 536 537 /* 538 * Find the buddy of @page and validate it. 539 * @page: The input page 540 * @pfn: The pfn of the page, it saves a call to page_to_pfn() when the 541 * function is used in the performance-critical __free_one_page(). 542 * @order: The order of the page 543 * @buddy_pfn: The output pointer to the buddy pfn, it also saves a call to 544 * page_to_pfn(). 545 * 546 * The found buddy can be a non PageBuddy, out of @page's zone, or its order is 547 * not the same as @page. The validation is necessary before use it. 548 * 549 * Return: the found buddy page or NULL if not found. 550 */ 551 static inline struct page *find_buddy_page_pfn(struct page *page, 552 unsigned long pfn, unsigned int order, unsigned long *buddy_pfn) 553 { 554 unsigned long __buddy_pfn = __find_buddy_pfn(pfn, order); 555 struct page *buddy; 556 557 buddy = page + (__buddy_pfn - pfn); 558 if (buddy_pfn) 559 *buddy_pfn = __buddy_pfn; 560 561 if (page_is_buddy(page, buddy, order)) 562 return buddy; 563 return NULL; 564 } 565 566 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn, 567 unsigned long end_pfn, struct zone *zone); 568 569 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn, 570 unsigned long end_pfn, struct zone *zone) 571 { 572 if (zone->contiguous) 573 return pfn_to_page(start_pfn); 574 575 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone); 576 } 577 578 void set_zone_contiguous(struct zone *zone); 579 580 static inline void clear_zone_contiguous(struct zone *zone) 581 { 582 zone->contiguous = false; 583 } 584 585 extern int __isolate_free_page(struct page *page, unsigned int order); 586 extern void __putback_isolated_page(struct page *page, unsigned int order, 587 int mt); 588 extern void memblock_free_pages(struct page *page, unsigned long pfn, 589 unsigned int order); 590 extern void __free_pages_core(struct page *page, unsigned int order); 591 extern void kernel_init_pages(struct page *page, int numpages); 592 593 /* 594 * This will have no effect, other than possibly generating a warning, if the 595 * caller passes in a non-large folio. 596 */ 597 static inline void folio_set_order(struct folio *folio, unsigned int order) 598 { 599 if (WARN_ON_ONCE(!order || !folio_test_large(folio))) 600 return; 601 602 folio->_flags_1 = (folio->_flags_1 & ~0xffUL) | order; 603 #ifdef CONFIG_64BIT 604 folio->_folio_nr_pages = 1U << order; 605 #endif 606 } 607 608 void folio_undo_large_rmappable(struct folio *folio); 609 610 static inline struct folio *page_rmappable_folio(struct page *page) 611 { 612 struct folio *folio = (struct folio *)page; 613 614 if (folio && folio_test_large(folio)) 615 folio_set_large_rmappable(folio); 616 return folio; 617 } 618 619 static inline void prep_compound_head(struct page *page, unsigned int order) 620 { 621 struct folio *folio = (struct folio *)page; 622 623 folio_set_order(folio, order); 624 atomic_set(&folio->_large_mapcount, -1); 625 atomic_set(&folio->_entire_mapcount, -1); 626 atomic_set(&folio->_nr_pages_mapped, 0); 627 atomic_set(&folio->_pincount, 0); 628 if (order > 1) 629 INIT_LIST_HEAD(&folio->_deferred_list); 630 } 631 632 static inline void prep_compound_tail(struct page *head, int tail_idx) 633 { 634 struct page *p = head + tail_idx; 635 636 p->mapping = TAIL_MAPPING; 637 set_compound_head(p, head); 638 set_page_private(p, 0); 639 } 640 641 extern void prep_compound_page(struct page *page, unsigned int order); 642 643 extern void post_alloc_hook(struct page *page, unsigned int order, 644 gfp_t gfp_flags); 645 extern bool free_pages_prepare(struct page *page, unsigned int order); 646 647 extern int user_min_free_kbytes; 648 649 void free_unref_page(struct page *page, unsigned int order); 650 void free_unref_folios(struct folio_batch *fbatch); 651 652 extern void zone_pcp_reset(struct zone *zone); 653 extern void zone_pcp_disable(struct zone *zone); 654 extern void zone_pcp_enable(struct zone *zone); 655 extern void zone_pcp_init(struct zone *zone); 656 657 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align, 658 phys_addr_t min_addr, 659 int nid, bool exact_nid); 660 661 void memmap_init_range(unsigned long, int, unsigned long, unsigned long, 662 unsigned long, enum meminit_context, struct vmem_altmap *, int); 663 664 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 665 666 /* 667 * in mm/compaction.c 668 */ 669 /* 670 * compact_control is used to track pages being migrated and the free pages 671 * they are being migrated to during memory compaction. The free_pfn starts 672 * at the end of a zone and migrate_pfn begins at the start. Movable pages 673 * are moved to the end of a zone during a compaction run and the run 674 * completes when free_pfn <= migrate_pfn 675 */ 676 struct compact_control { 677 struct list_head freepages[NR_PAGE_ORDERS]; /* List of free pages to migrate to */ 678 struct list_head migratepages; /* List of pages being migrated */ 679 unsigned int nr_freepages; /* Number of isolated free pages */ 680 unsigned int nr_migratepages; /* Number of pages to migrate */ 681 unsigned long free_pfn; /* isolate_freepages search base */ 682 /* 683 * Acts as an in/out parameter to page isolation for migration. 684 * isolate_migratepages uses it as a search base. 685 * isolate_migratepages_block will update the value to the next pfn 686 * after the last isolated one. 687 */ 688 unsigned long migrate_pfn; 689 unsigned long fast_start_pfn; /* a pfn to start linear scan from */ 690 struct zone *zone; 691 unsigned long total_migrate_scanned; 692 unsigned long total_free_scanned; 693 unsigned short fast_search_fail;/* failures to use free list searches */ 694 short search_order; /* order to start a fast search at */ 695 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 696 int order; /* order a direct compactor needs */ 697 int migratetype; /* migratetype of direct compactor */ 698 const unsigned int alloc_flags; /* alloc flags of a direct compactor */ 699 const int highest_zoneidx; /* zone index of a direct compactor */ 700 enum migrate_mode mode; /* Async or sync migration mode */ 701 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 702 bool no_set_skip_hint; /* Don't mark blocks for skipping */ 703 bool ignore_block_suitable; /* Scan blocks considered unsuitable */ 704 bool direct_compaction; /* False from kcompactd or /proc/... */ 705 bool proactive_compaction; /* kcompactd proactive compaction */ 706 bool whole_zone; /* Whole zone should/has been scanned */ 707 bool contended; /* Signal lock contention */ 708 bool finish_pageblock; /* Scan the remainder of a pageblock. Used 709 * when there are potentially transient 710 * isolation or migration failures to 711 * ensure forward progress. 712 */ 713 bool alloc_contig; /* alloc_contig_range allocation */ 714 }; 715 716 /* 717 * Used in direct compaction when a page should be taken from the freelists 718 * immediately when one is created during the free path. 719 */ 720 struct capture_control { 721 struct compact_control *cc; 722 struct page *page; 723 }; 724 725 unsigned long 726 isolate_freepages_range(struct compact_control *cc, 727 unsigned long start_pfn, unsigned long end_pfn); 728 int 729 isolate_migratepages_range(struct compact_control *cc, 730 unsigned long low_pfn, unsigned long end_pfn); 731 732 int __alloc_contig_migrate_range(struct compact_control *cc, 733 unsigned long start, unsigned long end, 734 int migratetype); 735 736 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */ 737 void init_cma_reserved_pageblock(struct page *page); 738 739 #endif /* CONFIG_COMPACTION || CONFIG_CMA */ 740 741 int find_suitable_fallback(struct free_area *area, unsigned int order, 742 int migratetype, bool only_stealable, bool *can_steal); 743 744 static inline bool free_area_empty(struct free_area *area, int migratetype) 745 { 746 return list_empty(&area->free_list[migratetype]); 747 } 748 749 /* 750 * These three helpers classifies VMAs for virtual memory accounting. 751 */ 752 753 /* 754 * Executable code area - executable, not writable, not stack 755 */ 756 static inline bool is_exec_mapping(vm_flags_t flags) 757 { 758 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; 759 } 760 761 /* 762 * Stack area (including shadow stacks) 763 * 764 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous: 765 * do_mmap() forbids all other combinations. 766 */ 767 static inline bool is_stack_mapping(vm_flags_t flags) 768 { 769 return ((flags & VM_STACK) == VM_STACK) || (flags & VM_SHADOW_STACK); 770 } 771 772 /* 773 * Data area - private, writable, not stack 774 */ 775 static inline bool is_data_mapping(vm_flags_t flags) 776 { 777 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; 778 } 779 780 /* mm/util.c */ 781 struct anon_vma *folio_anon_vma(struct folio *folio); 782 783 #ifdef CONFIG_MMU 784 void unmap_mapping_folio(struct folio *folio); 785 extern long populate_vma_page_range(struct vm_area_struct *vma, 786 unsigned long start, unsigned long end, int *locked); 787 extern long faultin_page_range(struct mm_struct *mm, unsigned long start, 788 unsigned long end, bool write, int *locked); 789 extern bool mlock_future_ok(struct mm_struct *mm, unsigned long flags, 790 unsigned long bytes); 791 792 /* 793 * NOTE: This function can't tell whether the folio is "fully mapped" in the 794 * range. 795 * "fully mapped" means all the pages of folio is associated with the page 796 * table of range while this function just check whether the folio range is 797 * within the range [start, end). Function caller needs to do page table 798 * check if it cares about the page table association. 799 * 800 * Typical usage (like mlock or madvise) is: 801 * Caller knows at least 1 page of folio is associated with page table of VMA 802 * and the range [start, end) is intersect with the VMA range. Caller wants 803 * to know whether the folio is fully associated with the range. It calls 804 * this function to check whether the folio is in the range first. Then checks 805 * the page table to know whether the folio is fully mapped to the range. 806 */ 807 static inline bool 808 folio_within_range(struct folio *folio, struct vm_area_struct *vma, 809 unsigned long start, unsigned long end) 810 { 811 pgoff_t pgoff, addr; 812 unsigned long vma_pglen = vma_pages(vma); 813 814 VM_WARN_ON_FOLIO(folio_test_ksm(folio), folio); 815 if (start > end) 816 return false; 817 818 if (start < vma->vm_start) 819 start = vma->vm_start; 820 821 if (end > vma->vm_end) 822 end = vma->vm_end; 823 824 pgoff = folio_pgoff(folio); 825 826 /* if folio start address is not in vma range */ 827 if (!in_range(pgoff, vma->vm_pgoff, vma_pglen)) 828 return false; 829 830 addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 831 832 return !(addr < start || end - addr < folio_size(folio)); 833 } 834 835 static inline bool 836 folio_within_vma(struct folio *folio, struct vm_area_struct *vma) 837 { 838 return folio_within_range(folio, vma, vma->vm_start, vma->vm_end); 839 } 840 841 /* 842 * mlock_vma_folio() and munlock_vma_folio(): 843 * should be called with vma's mmap_lock held for read or write, 844 * under page table lock for the pte/pmd being added or removed. 845 * 846 * mlock is usually called at the end of folio_add_*_rmap_*(), munlock at 847 * the end of folio_remove_rmap_*(); but new anon folios are managed by 848 * folio_add_lru_vma() calling mlock_new_folio(). 849 */ 850 void mlock_folio(struct folio *folio); 851 static inline void mlock_vma_folio(struct folio *folio, 852 struct vm_area_struct *vma) 853 { 854 /* 855 * The VM_SPECIAL check here serves two purposes. 856 * 1) VM_IO check prevents migration from double-counting during mlock. 857 * 2) Although mmap_region() and mlock_fixup() take care that VM_LOCKED 858 * is never left set on a VM_SPECIAL vma, there is an interval while 859 * file->f_op->mmap() is using vm_insert_page(s), when VM_LOCKED may 860 * still be set while VM_SPECIAL bits are added: so ignore it then. 861 */ 862 if (unlikely((vma->vm_flags & (VM_LOCKED|VM_SPECIAL)) == VM_LOCKED)) 863 mlock_folio(folio); 864 } 865 866 void munlock_folio(struct folio *folio); 867 static inline void munlock_vma_folio(struct folio *folio, 868 struct vm_area_struct *vma) 869 { 870 /* 871 * munlock if the function is called. Ideally, we should only 872 * do munlock if any page of folio is unmapped from VMA and 873 * cause folio not fully mapped to VMA. 874 * 875 * But it's not easy to confirm that's the situation. So we 876 * always munlock the folio and page reclaim will correct it 877 * if it's wrong. 878 */ 879 if (unlikely(vma->vm_flags & VM_LOCKED)) 880 munlock_folio(folio); 881 } 882 883 void mlock_new_folio(struct folio *folio); 884 bool need_mlock_drain(int cpu); 885 void mlock_drain_local(void); 886 void mlock_drain_remote(int cpu); 887 888 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 889 890 /** 891 * vma_address - Find the virtual address a page range is mapped at 892 * @vma: The vma which maps this object. 893 * @pgoff: The page offset within its object. 894 * @nr_pages: The number of pages to consider. 895 * 896 * If any page in this range is mapped by this VMA, return the first address 897 * where any of these pages appear. Otherwise, return -EFAULT. 898 */ 899 static inline unsigned long vma_address(struct vm_area_struct *vma, 900 pgoff_t pgoff, unsigned long nr_pages) 901 { 902 unsigned long address; 903 904 if (pgoff >= vma->vm_pgoff) { 905 address = vma->vm_start + 906 ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 907 /* Check for address beyond vma (or wrapped through 0?) */ 908 if (address < vma->vm_start || address >= vma->vm_end) 909 address = -EFAULT; 910 } else if (pgoff + nr_pages - 1 >= vma->vm_pgoff) { 911 /* Test above avoids possibility of wrap to 0 on 32-bit */ 912 address = vma->vm_start; 913 } else { 914 address = -EFAULT; 915 } 916 return address; 917 } 918 919 /* 920 * Then at what user virtual address will none of the range be found in vma? 921 * Assumes that vma_address() already returned a good starting address. 922 */ 923 static inline unsigned long vma_address_end(struct page_vma_mapped_walk *pvmw) 924 { 925 struct vm_area_struct *vma = pvmw->vma; 926 pgoff_t pgoff; 927 unsigned long address; 928 929 /* Common case, plus ->pgoff is invalid for KSM */ 930 if (pvmw->nr_pages == 1) 931 return pvmw->address + PAGE_SIZE; 932 933 pgoff = pvmw->pgoff + pvmw->nr_pages; 934 address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 935 /* Check for address beyond vma (or wrapped through 0?) */ 936 if (address < vma->vm_start || address > vma->vm_end) 937 address = vma->vm_end; 938 return address; 939 } 940 941 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, 942 struct file *fpin) 943 { 944 int flags = vmf->flags; 945 946 if (fpin) 947 return fpin; 948 949 /* 950 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or 951 * anything, so we only pin the file and drop the mmap_lock if only 952 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt. 953 */ 954 if (fault_flag_allow_retry_first(flags) && 955 !(flags & FAULT_FLAG_RETRY_NOWAIT)) { 956 fpin = get_file(vmf->vma->vm_file); 957 release_fault_lock(vmf); 958 } 959 return fpin; 960 } 961 #else /* !CONFIG_MMU */ 962 static inline void unmap_mapping_folio(struct folio *folio) { } 963 static inline void mlock_new_folio(struct folio *folio) { } 964 static inline bool need_mlock_drain(int cpu) { return false; } 965 static inline void mlock_drain_local(void) { } 966 static inline void mlock_drain_remote(int cpu) { } 967 static inline void vunmap_range_noflush(unsigned long start, unsigned long end) 968 { 969 } 970 #endif /* !CONFIG_MMU */ 971 972 /* Memory initialisation debug and verification */ 973 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 974 DECLARE_STATIC_KEY_TRUE(deferred_pages); 975 976 bool __init deferred_grow_zone(struct zone *zone, unsigned int order); 977 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 978 979 enum mminit_level { 980 MMINIT_WARNING, 981 MMINIT_VERIFY, 982 MMINIT_TRACE 983 }; 984 985 #ifdef CONFIG_DEBUG_MEMORY_INIT 986 987 extern int mminit_loglevel; 988 989 #define mminit_dprintk(level, prefix, fmt, arg...) \ 990 do { \ 991 if (level < mminit_loglevel) { \ 992 if (level <= MMINIT_WARNING) \ 993 pr_warn("mminit::" prefix " " fmt, ##arg); \ 994 else \ 995 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 996 } \ 997 } while (0) 998 999 extern void mminit_verify_pageflags_layout(void); 1000 extern void mminit_verify_zonelist(void); 1001 #else 1002 1003 static inline void mminit_dprintk(enum mminit_level level, 1004 const char *prefix, const char *fmt, ...) 1005 { 1006 } 1007 1008 static inline void mminit_verify_pageflags_layout(void) 1009 { 1010 } 1011 1012 static inline void mminit_verify_zonelist(void) 1013 { 1014 } 1015 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 1016 1017 #define NODE_RECLAIM_NOSCAN -2 1018 #define NODE_RECLAIM_FULL -1 1019 #define NODE_RECLAIM_SOME 0 1020 #define NODE_RECLAIM_SUCCESS 1 1021 1022 #ifdef CONFIG_NUMA 1023 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); 1024 extern int find_next_best_node(int node, nodemask_t *used_node_mask); 1025 #else 1026 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, 1027 unsigned int order) 1028 { 1029 return NODE_RECLAIM_NOSCAN; 1030 } 1031 static inline int find_next_best_node(int node, nodemask_t *used_node_mask) 1032 { 1033 return NUMA_NO_NODE; 1034 } 1035 #endif 1036 1037 /* 1038 * mm/memory-failure.c 1039 */ 1040 void shake_folio(struct folio *folio); 1041 extern int hwpoison_filter(struct page *p); 1042 1043 extern u32 hwpoison_filter_dev_major; 1044 extern u32 hwpoison_filter_dev_minor; 1045 extern u64 hwpoison_filter_flags_mask; 1046 extern u64 hwpoison_filter_flags_value; 1047 extern u64 hwpoison_filter_memcg; 1048 extern u32 hwpoison_filter_enable; 1049 1050 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 1051 unsigned long, unsigned long, 1052 unsigned long, unsigned long); 1053 1054 extern void set_pageblock_order(void); 1055 unsigned long reclaim_pages(struct list_head *folio_list); 1056 unsigned int reclaim_clean_pages_from_list(struct zone *zone, 1057 struct list_head *folio_list); 1058 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 1059 #define ALLOC_WMARK_MIN WMARK_MIN 1060 #define ALLOC_WMARK_LOW WMARK_LOW 1061 #define ALLOC_WMARK_HIGH WMARK_HIGH 1062 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 1063 1064 /* Mask to get the watermark bits */ 1065 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 1066 1067 /* 1068 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we 1069 * cannot assume a reduced access to memory reserves is sufficient for 1070 * !MMU 1071 */ 1072 #ifdef CONFIG_MMU 1073 #define ALLOC_OOM 0x08 1074 #else 1075 #define ALLOC_OOM ALLOC_NO_WATERMARKS 1076 #endif 1077 1078 #define ALLOC_NON_BLOCK 0x10 /* Caller cannot block. Allow access 1079 * to 25% of the min watermark or 1080 * 62.5% if __GFP_HIGH is set. 1081 */ 1082 #define ALLOC_MIN_RESERVE 0x20 /* __GFP_HIGH set. Allow access to 50% 1083 * of the min watermark. 1084 */ 1085 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1086 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 1087 #ifdef CONFIG_ZONE_DMA32 1088 #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */ 1089 #else 1090 #define ALLOC_NOFRAGMENT 0x0 1091 #endif 1092 #define ALLOC_HIGHATOMIC 0x200 /* Allows access to MIGRATE_HIGHATOMIC */ 1093 #define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */ 1094 1095 /* Flags that allow allocations below the min watermark. */ 1096 #define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM) 1097 1098 enum ttu_flags; 1099 struct tlbflush_unmap_batch; 1100 1101 1102 /* 1103 * only for MM internal work items which do not depend on 1104 * any allocations or locks which might depend on allocations 1105 */ 1106 extern struct workqueue_struct *mm_percpu_wq; 1107 1108 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 1109 void try_to_unmap_flush(void); 1110 void try_to_unmap_flush_dirty(void); 1111 void flush_tlb_batched_pending(struct mm_struct *mm); 1112 #else 1113 static inline void try_to_unmap_flush(void) 1114 { 1115 } 1116 static inline void try_to_unmap_flush_dirty(void) 1117 { 1118 } 1119 static inline void flush_tlb_batched_pending(struct mm_struct *mm) 1120 { 1121 } 1122 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 1123 1124 extern const struct trace_print_flags pageflag_names[]; 1125 extern const struct trace_print_flags pagetype_names[]; 1126 extern const struct trace_print_flags vmaflag_names[]; 1127 extern const struct trace_print_flags gfpflag_names[]; 1128 1129 static inline bool is_migrate_highatomic(enum migratetype migratetype) 1130 { 1131 return migratetype == MIGRATE_HIGHATOMIC; 1132 } 1133 1134 void setup_zone_pageset(struct zone *zone); 1135 1136 struct migration_target_control { 1137 int nid; /* preferred node id */ 1138 nodemask_t *nmask; 1139 gfp_t gfp_mask; 1140 enum migrate_reason reason; 1141 }; 1142 1143 /* 1144 * mm/filemap.c 1145 */ 1146 size_t splice_folio_into_pipe(struct pipe_inode_info *pipe, 1147 struct folio *folio, loff_t fpos, size_t size); 1148 1149 /* 1150 * mm/vmalloc.c 1151 */ 1152 #ifdef CONFIG_MMU 1153 void __init vmalloc_init(void); 1154 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end, 1155 pgprot_t prot, struct page **pages, unsigned int page_shift); 1156 #else 1157 static inline void vmalloc_init(void) 1158 { 1159 } 1160 1161 static inline 1162 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end, 1163 pgprot_t prot, struct page **pages, unsigned int page_shift) 1164 { 1165 return -EINVAL; 1166 } 1167 #endif 1168 1169 int __must_check __vmap_pages_range_noflush(unsigned long addr, 1170 unsigned long end, pgprot_t prot, 1171 struct page **pages, unsigned int page_shift); 1172 1173 void vunmap_range_noflush(unsigned long start, unsigned long end); 1174 1175 void __vunmap_range_noflush(unsigned long start, unsigned long end); 1176 1177 int numa_migrate_prep(struct folio *folio, struct vm_fault *vmf, 1178 unsigned long addr, int page_nid, int *flags); 1179 1180 void free_zone_device_folio(struct folio *folio); 1181 int migrate_device_coherent_page(struct page *page); 1182 1183 /* 1184 * mm/gup.c 1185 */ 1186 struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags); 1187 int __must_check try_grab_page(struct page *page, unsigned int flags); 1188 1189 /* 1190 * mm/huge_memory.c 1191 */ 1192 void touch_pud(struct vm_area_struct *vma, unsigned long addr, 1193 pud_t *pud, bool write); 1194 void touch_pmd(struct vm_area_struct *vma, unsigned long addr, 1195 pmd_t *pmd, bool write); 1196 1197 /* 1198 * mm/mmap.c 1199 */ 1200 struct vm_area_struct *vma_merge_extend(struct vma_iterator *vmi, 1201 struct vm_area_struct *vma, 1202 unsigned long delta); 1203 1204 enum { 1205 /* mark page accessed */ 1206 FOLL_TOUCH = 1 << 16, 1207 /* a retry, previous pass started an IO */ 1208 FOLL_TRIED = 1 << 17, 1209 /* we are working on non-current tsk/mm */ 1210 FOLL_REMOTE = 1 << 18, 1211 /* pages must be released via unpin_user_page */ 1212 FOLL_PIN = 1 << 19, 1213 /* gup_fast: prevent fall-back to slow gup */ 1214 FOLL_FAST_ONLY = 1 << 20, 1215 /* allow unlocking the mmap lock */ 1216 FOLL_UNLOCKABLE = 1 << 21, 1217 /* VMA lookup+checks compatible with MADV_POPULATE_(READ|WRITE) */ 1218 FOLL_MADV_POPULATE = 1 << 22, 1219 }; 1220 1221 #define INTERNAL_GUP_FLAGS (FOLL_TOUCH | FOLL_TRIED | FOLL_REMOTE | FOLL_PIN | \ 1222 FOLL_FAST_ONLY | FOLL_UNLOCKABLE | \ 1223 FOLL_MADV_POPULATE) 1224 1225 /* 1226 * Indicates for which pages that are write-protected in the page table, 1227 * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that the 1228 * GUP pin will remain consistent with the pages mapped into the page tables 1229 * of the MM. 1230 * 1231 * Temporary unmapping of PageAnonExclusive() pages or clearing of 1232 * PageAnonExclusive() has to protect against concurrent GUP: 1233 * * Ordinary GUP: Using the PT lock 1234 * * GUP-fast and fork(): mm->write_protect_seq 1235 * * GUP-fast and KSM or temporary unmapping (swap, migration): see 1236 * folio_try_share_anon_rmap_*() 1237 * 1238 * Must be called with the (sub)page that's actually referenced via the 1239 * page table entry, which might not necessarily be the head page for a 1240 * PTE-mapped THP. 1241 * 1242 * If the vma is NULL, we're coming from the GUP-fast path and might have 1243 * to fallback to the slow path just to lookup the vma. 1244 */ 1245 static inline bool gup_must_unshare(struct vm_area_struct *vma, 1246 unsigned int flags, struct page *page) 1247 { 1248 /* 1249 * FOLL_WRITE is implicitly handled correctly as the page table entry 1250 * has to be writable -- and if it references (part of) an anonymous 1251 * folio, that part is required to be marked exclusive. 1252 */ 1253 if ((flags & (FOLL_WRITE | FOLL_PIN)) != FOLL_PIN) 1254 return false; 1255 /* 1256 * Note: PageAnon(page) is stable until the page is actually getting 1257 * freed. 1258 */ 1259 if (!PageAnon(page)) { 1260 /* 1261 * We only care about R/O long-term pining: R/O short-term 1262 * pinning does not have the semantics to observe successive 1263 * changes through the process page tables. 1264 */ 1265 if (!(flags & FOLL_LONGTERM)) 1266 return false; 1267 1268 /* We really need the vma ... */ 1269 if (!vma) 1270 return true; 1271 1272 /* 1273 * ... because we only care about writable private ("COW") 1274 * mappings where we have to break COW early. 1275 */ 1276 return is_cow_mapping(vma->vm_flags); 1277 } 1278 1279 /* Paired with a memory barrier in folio_try_share_anon_rmap_*(). */ 1280 if (IS_ENABLED(CONFIG_HAVE_GUP_FAST)) 1281 smp_rmb(); 1282 1283 /* 1284 * Note that PageKsm() pages cannot be exclusive, and consequently, 1285 * cannot get pinned. 1286 */ 1287 return !PageAnonExclusive(page); 1288 } 1289 1290 extern bool mirrored_kernelcore; 1291 extern bool memblock_has_mirror(void); 1292 1293 static __always_inline void vma_set_range(struct vm_area_struct *vma, 1294 unsigned long start, unsigned long end, 1295 pgoff_t pgoff) 1296 { 1297 vma->vm_start = start; 1298 vma->vm_end = end; 1299 vma->vm_pgoff = pgoff; 1300 } 1301 1302 static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma) 1303 { 1304 /* 1305 * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty 1306 * enablements, because when without soft-dirty being compiled in, 1307 * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY) 1308 * will be constantly true. 1309 */ 1310 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) 1311 return false; 1312 1313 /* 1314 * Soft-dirty is kind of special: its tracking is enabled when the 1315 * vma flags not set. 1316 */ 1317 return !(vma->vm_flags & VM_SOFTDIRTY); 1318 } 1319 1320 static inline void vma_iter_config(struct vma_iterator *vmi, 1321 unsigned long index, unsigned long last) 1322 { 1323 __mas_set_range(&vmi->mas, index, last - 1); 1324 } 1325 1326 static inline void vma_iter_reset(struct vma_iterator *vmi) 1327 { 1328 mas_reset(&vmi->mas); 1329 } 1330 1331 static inline 1332 struct vm_area_struct *vma_iter_prev_range_limit(struct vma_iterator *vmi, unsigned long min) 1333 { 1334 return mas_prev_range(&vmi->mas, min); 1335 } 1336 1337 static inline 1338 struct vm_area_struct *vma_iter_next_range_limit(struct vma_iterator *vmi, unsigned long max) 1339 { 1340 return mas_next_range(&vmi->mas, max); 1341 } 1342 1343 static inline int vma_iter_area_lowest(struct vma_iterator *vmi, unsigned long min, 1344 unsigned long max, unsigned long size) 1345 { 1346 return mas_empty_area(&vmi->mas, min, max - 1, size); 1347 } 1348 1349 static inline int vma_iter_area_highest(struct vma_iterator *vmi, unsigned long min, 1350 unsigned long max, unsigned long size) 1351 { 1352 return mas_empty_area_rev(&vmi->mas, min, max - 1, size); 1353 } 1354 1355 /* 1356 * VMA Iterator functions shared between nommu and mmap 1357 */ 1358 static inline int vma_iter_prealloc(struct vma_iterator *vmi, 1359 struct vm_area_struct *vma) 1360 { 1361 return mas_preallocate(&vmi->mas, vma, GFP_KERNEL); 1362 } 1363 1364 static inline void vma_iter_clear(struct vma_iterator *vmi) 1365 { 1366 mas_store_prealloc(&vmi->mas, NULL); 1367 } 1368 1369 static inline struct vm_area_struct *vma_iter_load(struct vma_iterator *vmi) 1370 { 1371 return mas_walk(&vmi->mas); 1372 } 1373 1374 /* Store a VMA with preallocated memory */ 1375 static inline void vma_iter_store(struct vma_iterator *vmi, 1376 struct vm_area_struct *vma) 1377 { 1378 1379 #if defined(CONFIG_DEBUG_VM_MAPLE_TREE) 1380 if (MAS_WARN_ON(&vmi->mas, vmi->mas.status != ma_start && 1381 vmi->mas.index > vma->vm_start)) { 1382 pr_warn("%lx > %lx\n store vma %lx-%lx\n into slot %lx-%lx\n", 1383 vmi->mas.index, vma->vm_start, vma->vm_start, 1384 vma->vm_end, vmi->mas.index, vmi->mas.last); 1385 } 1386 if (MAS_WARN_ON(&vmi->mas, vmi->mas.status != ma_start && 1387 vmi->mas.last < vma->vm_start)) { 1388 pr_warn("%lx < %lx\nstore vma %lx-%lx\ninto slot %lx-%lx\n", 1389 vmi->mas.last, vma->vm_start, vma->vm_start, vma->vm_end, 1390 vmi->mas.index, vmi->mas.last); 1391 } 1392 #endif 1393 1394 if (vmi->mas.status != ma_start && 1395 ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start))) 1396 vma_iter_invalidate(vmi); 1397 1398 __mas_set_range(&vmi->mas, vma->vm_start, vma->vm_end - 1); 1399 mas_store_prealloc(&vmi->mas, vma); 1400 } 1401 1402 static inline int vma_iter_store_gfp(struct vma_iterator *vmi, 1403 struct vm_area_struct *vma, gfp_t gfp) 1404 { 1405 if (vmi->mas.status != ma_start && 1406 ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start))) 1407 vma_iter_invalidate(vmi); 1408 1409 __mas_set_range(&vmi->mas, vma->vm_start, vma->vm_end - 1); 1410 mas_store_gfp(&vmi->mas, vma, gfp); 1411 if (unlikely(mas_is_err(&vmi->mas))) 1412 return -ENOMEM; 1413 1414 return 0; 1415 } 1416 1417 /* 1418 * VMA lock generalization 1419 */ 1420 struct vma_prepare { 1421 struct vm_area_struct *vma; 1422 struct vm_area_struct *adj_next; 1423 struct file *file; 1424 struct address_space *mapping; 1425 struct anon_vma *anon_vma; 1426 struct vm_area_struct *insert; 1427 struct vm_area_struct *remove; 1428 struct vm_area_struct *remove2; 1429 }; 1430 1431 void __meminit __init_single_page(struct page *page, unsigned long pfn, 1432 unsigned long zone, int nid); 1433 1434 /* shrinker related functions */ 1435 unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg, 1436 int priority); 1437 1438 #ifdef CONFIG_64BIT 1439 /* VM is sealed, in vm_flags */ 1440 #define VM_SEALED _BITUL(63) 1441 #endif 1442 1443 #ifdef CONFIG_64BIT 1444 static inline int can_do_mseal(unsigned long flags) 1445 { 1446 if (flags) 1447 return -EINVAL; 1448 1449 return 0; 1450 } 1451 1452 bool can_modify_mm(struct mm_struct *mm, unsigned long start, 1453 unsigned long end); 1454 bool can_modify_mm_madv(struct mm_struct *mm, unsigned long start, 1455 unsigned long end, int behavior); 1456 #else 1457 static inline int can_do_mseal(unsigned long flags) 1458 { 1459 return -EPERM; 1460 } 1461 1462 static inline bool can_modify_mm(struct mm_struct *mm, unsigned long start, 1463 unsigned long end) 1464 { 1465 return true; 1466 } 1467 1468 static inline bool can_modify_mm_madv(struct mm_struct *mm, unsigned long start, 1469 unsigned long end, int behavior) 1470 { 1471 return true; 1472 } 1473 #endif 1474 1475 #ifdef CONFIG_SHRINKER_DEBUG 1476 static inline __printf(2, 0) int shrinker_debugfs_name_alloc( 1477 struct shrinker *shrinker, const char *fmt, va_list ap) 1478 { 1479 shrinker->name = kvasprintf_const(GFP_KERNEL, fmt, ap); 1480 1481 return shrinker->name ? 0 : -ENOMEM; 1482 } 1483 1484 static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) 1485 { 1486 kfree_const(shrinker->name); 1487 shrinker->name = NULL; 1488 } 1489 1490 extern int shrinker_debugfs_add(struct shrinker *shrinker); 1491 extern struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, 1492 int *debugfs_id); 1493 extern void shrinker_debugfs_remove(struct dentry *debugfs_entry, 1494 int debugfs_id); 1495 #else /* CONFIG_SHRINKER_DEBUG */ 1496 static inline int shrinker_debugfs_add(struct shrinker *shrinker) 1497 { 1498 return 0; 1499 } 1500 static inline int shrinker_debugfs_name_alloc(struct shrinker *shrinker, 1501 const char *fmt, va_list ap) 1502 { 1503 return 0; 1504 } 1505 static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) 1506 { 1507 } 1508 static inline struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, 1509 int *debugfs_id) 1510 { 1511 *debugfs_id = -1; 1512 return NULL; 1513 } 1514 static inline void shrinker_debugfs_remove(struct dentry *debugfs_entry, 1515 int debugfs_id) 1516 { 1517 } 1518 #endif /* CONFIG_SHRINKER_DEBUG */ 1519 1520 /* Only track the nodes of mappings with shadow entries */ 1521 void workingset_update_node(struct xa_node *node); 1522 extern struct list_lru shadow_nodes; 1523 1524 #endif /* __MM_INTERNAL_H */ 1525