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/khugepaged.h> 12 #include <linux/mm.h> 13 #include <linux/mm_inline.h> 14 #include <linux/pagemap.h> 15 #include <linux/pagewalk.h> 16 #include <linux/rmap.h> 17 #include <linux/swap.h> 18 #include <linux/swapops.h> 19 #include <linux/swap_cgroup.h> 20 #include <linux/tracepoint-defs.h> 21 22 /* Internal core VMA manipulation functions. */ 23 #include "vma.h" 24 25 struct folio_batch; 26 27 /* 28 * Maintains state across a page table move. The operation assumes both source 29 * and destination VMAs already exist and are specified by the user. 30 * 31 * Partial moves are permitted, but the old and new ranges must both reside 32 * within a VMA. 33 * 34 * mmap lock must be held in write and VMA write locks must be held on any VMA 35 * that is visible. 36 * 37 * Use the PAGETABLE_MOVE() macro to initialise this struct. 38 * 39 * The old_addr and new_addr fields are updated as the page table move is 40 * executed. 41 * 42 * NOTE: The page table move is affected by reading from [old_addr, old_end), 43 * and old_addr may be updated for better page table alignment, so len_in 44 * represents the length of the range being copied as specified by the user. 45 */ 46 struct pagetable_move_control { 47 struct vm_area_struct *old; /* Source VMA. */ 48 struct vm_area_struct *new; /* Destination VMA. */ 49 unsigned long old_addr; /* Address from which the move begins. */ 50 unsigned long old_end; /* Exclusive address at which old range ends. */ 51 unsigned long new_addr; /* Address to move page tables to. */ 52 unsigned long len_in; /* Bytes to remap specified by user. */ 53 54 bool need_rmap_locks; /* Do rmap locks need to be taken? */ 55 bool for_stack; /* Is this an early temp stack being moved? */ 56 }; 57 58 #define PAGETABLE_MOVE(name, old_, new_, old_addr_, new_addr_, len_) \ 59 struct pagetable_move_control name = { \ 60 .old = old_, \ 61 .new = new_, \ 62 .old_addr = old_addr_, \ 63 .old_end = (old_addr_) + (len_), \ 64 .new_addr = new_addr_, \ 65 .len_in = len_, \ 66 } 67 68 /* 69 * The set of flags that only affect watermark checking and reclaim 70 * behaviour. This is used by the MM to obey the caller constraints 71 * about IO, FS and watermark checking while ignoring placement 72 * hints such as HIGHMEM usage. 73 */ 74 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\ 75 __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\ 76 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\ 77 __GFP_NOLOCKDEP) 78 79 /* The GFP flags allowed during early boot */ 80 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS)) 81 82 /* Control allocation cpuset and node placement constraints */ 83 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE) 84 85 /* Do not use these with a slab allocator */ 86 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) 87 88 /* 89 * Different from WARN_ON_ONCE(), no warning will be issued 90 * when we specify __GFP_NOWARN. 91 */ 92 #define WARN_ON_ONCE_GFP(cond, gfp) ({ \ 93 static bool __section(".data..once") __warned; \ 94 int __ret_warn_once = !!(cond); \ 95 \ 96 if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \ 97 __warned = true; \ 98 WARN_ON(1); \ 99 } \ 100 unlikely(__ret_warn_once); \ 101 }) 102 103 void page_writeback_init(void); 104 105 /* 106 * If a 16GB hugetlb folio were mapped by PTEs of all of its 4kB pages, 107 * its nr_pages_mapped would be 0x400000: choose the ENTIRELY_MAPPED bit 108 * above that range, instead of 2*(PMD_SIZE/PAGE_SIZE). Hugetlb currently 109 * leaves nr_pages_mapped at 0, but avoid surprise if it participates later. 110 */ 111 #define ENTIRELY_MAPPED 0x800000 112 #define FOLIO_PAGES_MAPPED (ENTIRELY_MAPPED - 1) 113 114 /* 115 * Flags passed to __show_mem() and show_free_areas() to suppress output in 116 * various contexts. 117 */ 118 #define SHOW_MEM_FILTER_NODES (0x0001u) /* disallowed nodes */ 119 120 /* 121 * How many individual pages have an elevated _mapcount. Excludes 122 * the folio's entire_mapcount. 123 * 124 * Don't use this function outside of debugging code. 125 */ 126 static inline int folio_nr_pages_mapped(const struct folio *folio) 127 { 128 if (IS_ENABLED(CONFIG_NO_PAGE_MAPCOUNT)) 129 return -1; 130 return atomic_read(&folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED; 131 } 132 133 /* 134 * Retrieve the first entry of a folio based on a provided entry within the 135 * folio. We cannot rely on folio->swap as there is no guarantee that it has 136 * been initialized. Used for calling arch_swap_restore() 137 */ 138 static inline swp_entry_t folio_swap(swp_entry_t entry, 139 const struct folio *folio) 140 { 141 swp_entry_t swap = { 142 .val = ALIGN_DOWN(entry.val, folio_nr_pages(folio)), 143 }; 144 145 return swap; 146 } 147 148 static inline void *folio_raw_mapping(const struct folio *folio) 149 { 150 unsigned long mapping = (unsigned long)folio->mapping; 151 152 return (void *)(mapping & ~FOLIO_MAPPING_FLAGS); 153 } 154 155 /* 156 * This is a file-backed mapping, and is about to be memory mapped - invoke its 157 * mmap hook and safely handle error conditions. On error, VMA hooks will be 158 * mutated. 159 * 160 * @file: File which backs the mapping. 161 * @vma: VMA which we are mapping. 162 * 163 * Returns: 0 if success, error otherwise. 164 */ 165 static inline int mmap_file(struct file *file, struct vm_area_struct *vma) 166 { 167 int err = call_mmap(file, vma); 168 169 if (likely(!err)) 170 return 0; 171 172 /* 173 * OK, we tried to call the file hook for mmap(), but an error 174 * arose. The mapping is in an inconsistent state and we most not invoke 175 * any further hooks on it. 176 */ 177 vma->vm_ops = &vma_dummy_vm_ops; 178 179 return err; 180 } 181 182 /* 183 * If the VMA has a close hook then close it, and since closing it might leave 184 * it in an inconsistent state which makes the use of any hooks suspect, clear 185 * them down by installing dummy empty hooks. 186 */ 187 static inline void vma_close(struct vm_area_struct *vma) 188 { 189 if (vma->vm_ops && vma->vm_ops->close) { 190 vma->vm_ops->close(vma); 191 192 /* 193 * The mapping is in an inconsistent state, and no further hooks 194 * may be invoked upon it. 195 */ 196 vma->vm_ops = &vma_dummy_vm_ops; 197 } 198 } 199 200 #ifdef CONFIG_MMU 201 202 /* Flags for folio_pte_batch(). */ 203 typedef int __bitwise fpb_t; 204 205 /* Compare PTEs respecting the dirty bit. */ 206 #define FPB_RESPECT_DIRTY ((__force fpb_t)BIT(0)) 207 208 /* Compare PTEs respecting the soft-dirty bit. */ 209 #define FPB_RESPECT_SOFT_DIRTY ((__force fpb_t)BIT(1)) 210 211 /* 212 * Merge PTE write bits: if any PTE in the batch is writable, modify the 213 * PTE at @ptentp to be writable. 214 */ 215 #define FPB_MERGE_WRITE ((__force fpb_t)BIT(2)) 216 217 /* 218 * Merge PTE young and dirty bits: if any PTE in the batch is young or dirty, 219 * modify the PTE at @ptentp to be young or dirty, respectively. 220 */ 221 #define FPB_MERGE_YOUNG_DIRTY ((__force fpb_t)BIT(3)) 222 223 static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags) 224 { 225 if (!(flags & FPB_RESPECT_DIRTY)) 226 pte = pte_mkclean(pte); 227 if (likely(!(flags & FPB_RESPECT_SOFT_DIRTY))) 228 pte = pte_clear_soft_dirty(pte); 229 return pte_wrprotect(pte_mkold(pte)); 230 } 231 232 /** 233 * folio_pte_batch_flags - detect a PTE batch for a large folio 234 * @folio: The large folio to detect a PTE batch for. 235 * @vma: The VMA. Only relevant with FPB_MERGE_WRITE, otherwise can be NULL. 236 * @ptep: Page table pointer for the first entry. 237 * @ptentp: Pointer to a COPY of the first page table entry whose flags this 238 * function updates based on @flags if appropriate. 239 * @max_nr: The maximum number of table entries to consider. 240 * @flags: Flags to modify the PTE batch semantics. 241 * 242 * Detect a PTE batch: consecutive (present) PTEs that map consecutive 243 * pages of the same large folio in a single VMA and a single page table. 244 * 245 * All PTEs inside a PTE batch have the same PTE bits set, excluding the PFN, 246 * the accessed bit, writable bit, dirty bit (unless FPB_RESPECT_DIRTY is set) 247 * and soft-dirty bit (unless FPB_RESPECT_SOFT_DIRTY is set). 248 * 249 * @ptep must map any page of the folio. max_nr must be at least one and 250 * must be limited by the caller so scanning cannot exceed a single VMA and 251 * a single page table. 252 * 253 * Depending on the FPB_MERGE_* flags, the pte stored at @ptentp will 254 * be updated: it's crucial that a pointer to a COPY of the first 255 * page table entry, obtained through ptep_get(), is provided as @ptentp. 256 * 257 * This function will be inlined to optimize based on the input parameters; 258 * consider using folio_pte_batch() instead if applicable. 259 * 260 * Return: the number of table entries in the batch. 261 */ 262 static inline unsigned int folio_pte_batch_flags(struct folio *folio, 263 struct vm_area_struct *vma, pte_t *ptep, pte_t *ptentp, 264 unsigned int max_nr, fpb_t flags) 265 { 266 bool any_writable = false, any_young = false, any_dirty = false; 267 pte_t expected_pte, pte = *ptentp; 268 unsigned int nr, cur_nr; 269 270 VM_WARN_ON_FOLIO(!pte_present(pte), folio); 271 VM_WARN_ON_FOLIO(!folio_test_large(folio) || max_nr < 1, folio); 272 VM_WARN_ON_FOLIO(page_folio(pfn_to_page(pte_pfn(pte))) != folio, folio); 273 /* 274 * Ensure this is a pointer to a copy not a pointer into a page table. 275 * If this is a stack value, it won't be a valid virtual address, but 276 * that's fine because it also cannot be pointing into the page table. 277 */ 278 VM_WARN_ON(virt_addr_valid(ptentp) && PageTable(virt_to_page(ptentp))); 279 280 /* Limit max_nr to the actual remaining PFNs in the folio we could batch. */ 281 max_nr = min_t(unsigned long, max_nr, 282 folio_pfn(folio) + folio_nr_pages(folio) - pte_pfn(pte)); 283 284 nr = pte_batch_hint(ptep, pte); 285 expected_pte = __pte_batch_clear_ignored(pte_advance_pfn(pte, nr), flags); 286 ptep = ptep + nr; 287 288 while (nr < max_nr) { 289 pte = ptep_get(ptep); 290 291 if (!pte_same(__pte_batch_clear_ignored(pte, flags), expected_pte)) 292 break; 293 294 if (flags & FPB_MERGE_WRITE) 295 any_writable |= pte_write(pte); 296 if (flags & FPB_MERGE_YOUNG_DIRTY) { 297 any_young |= pte_young(pte); 298 any_dirty |= pte_dirty(pte); 299 } 300 301 cur_nr = pte_batch_hint(ptep, pte); 302 expected_pte = pte_advance_pfn(expected_pte, cur_nr); 303 ptep += cur_nr; 304 nr += cur_nr; 305 } 306 307 if (any_writable) 308 *ptentp = pte_mkwrite(*ptentp, vma); 309 if (any_young) 310 *ptentp = pte_mkyoung(*ptentp); 311 if (any_dirty) 312 *ptentp = pte_mkdirty(*ptentp); 313 314 return min(nr, max_nr); 315 } 316 317 unsigned int folio_pte_batch(struct folio *folio, pte_t *ptep, pte_t pte, 318 unsigned int max_nr); 319 320 /** 321 * pte_move_swp_offset - Move the swap entry offset field of a swap pte 322 * forward or backward by delta 323 * @pte: The initial pte state; is_swap_pte(pte) must be true and 324 * non_swap_entry() must be false. 325 * @delta: The direction and the offset we are moving; forward if delta 326 * is positive; backward if delta is negative 327 * 328 * Moves the swap offset, while maintaining all other fields, including 329 * swap type, and any swp pte bits. The resulting pte is returned. 330 */ 331 static inline pte_t pte_move_swp_offset(pte_t pte, long delta) 332 { 333 swp_entry_t entry = pte_to_swp_entry(pte); 334 pte_t new = __swp_entry_to_pte(__swp_entry(swp_type(entry), 335 (swp_offset(entry) + delta))); 336 337 if (pte_swp_soft_dirty(pte)) 338 new = pte_swp_mksoft_dirty(new); 339 if (pte_swp_exclusive(pte)) 340 new = pte_swp_mkexclusive(new); 341 if (pte_swp_uffd_wp(pte)) 342 new = pte_swp_mkuffd_wp(new); 343 344 return new; 345 } 346 347 348 /** 349 * pte_next_swp_offset - Increment the swap entry offset field of a swap pte. 350 * @pte: The initial pte state; is_swap_pte(pte) must be true and 351 * non_swap_entry() must be false. 352 * 353 * Increments the swap offset, while maintaining all other fields, including 354 * swap type, and any swp pte bits. The resulting pte is returned. 355 */ 356 static inline pte_t pte_next_swp_offset(pte_t pte) 357 { 358 return pte_move_swp_offset(pte, 1); 359 } 360 361 /** 362 * swap_pte_batch - detect a PTE batch for a set of contiguous swap entries 363 * @start_ptep: Page table pointer for the first entry. 364 * @max_nr: The maximum number of table entries to consider. 365 * @pte: Page table entry for the first entry. 366 * 367 * Detect a batch of contiguous swap entries: consecutive (non-present) PTEs 368 * containing swap entries all with consecutive offsets and targeting the same 369 * swap type, all with matching swp pte bits. 370 * 371 * max_nr must be at least one and must be limited by the caller so scanning 372 * cannot exceed a single page table. 373 * 374 * Return: the number of table entries in the batch. 375 */ 376 static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte) 377 { 378 pte_t expected_pte = pte_next_swp_offset(pte); 379 const pte_t *end_ptep = start_ptep + max_nr; 380 swp_entry_t entry = pte_to_swp_entry(pte); 381 pte_t *ptep = start_ptep + 1; 382 unsigned short cgroup_id; 383 384 VM_WARN_ON(max_nr < 1); 385 VM_WARN_ON(!is_swap_pte(pte)); 386 VM_WARN_ON(non_swap_entry(entry)); 387 388 cgroup_id = lookup_swap_cgroup_id(entry); 389 while (ptep < end_ptep) { 390 pte = ptep_get(ptep); 391 392 if (!pte_same(pte, expected_pte)) 393 break; 394 if (lookup_swap_cgroup_id(pte_to_swp_entry(pte)) != cgroup_id) 395 break; 396 expected_pte = pte_next_swp_offset(expected_pte); 397 ptep++; 398 } 399 400 return ptep - start_ptep; 401 } 402 #endif /* CONFIG_MMU */ 403 404 void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio, 405 int nr_throttled); 406 static inline void acct_reclaim_writeback(struct folio *folio) 407 { 408 pg_data_t *pgdat = folio_pgdat(folio); 409 int nr_throttled = atomic_read(&pgdat->nr_writeback_throttled); 410 411 if (nr_throttled) 412 __acct_reclaim_writeback(pgdat, folio, nr_throttled); 413 } 414 415 static inline void wake_throttle_isolated(pg_data_t *pgdat) 416 { 417 wait_queue_head_t *wqh; 418 419 wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED]; 420 if (waitqueue_active(wqh)) 421 wake_up(wqh); 422 } 423 424 vm_fault_t __vmf_anon_prepare(struct vm_fault *vmf); 425 static inline vm_fault_t vmf_anon_prepare(struct vm_fault *vmf) 426 { 427 vm_fault_t ret = __vmf_anon_prepare(vmf); 428 429 if (unlikely(ret & VM_FAULT_RETRY)) 430 vma_end_read(vmf->vma); 431 return ret; 432 } 433 434 vm_fault_t do_swap_page(struct vm_fault *vmf); 435 void folio_rotate_reclaimable(struct folio *folio); 436 bool __folio_end_writeback(struct folio *folio); 437 void deactivate_file_folio(struct folio *folio); 438 void folio_activate(struct folio *folio); 439 440 void free_pgtables(struct mmu_gather *tlb, struct ma_state *mas, 441 struct vm_area_struct *start_vma, unsigned long floor, 442 unsigned long ceiling, bool mm_wr_locked); 443 void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte); 444 445 struct zap_details; 446 void unmap_page_range(struct mmu_gather *tlb, 447 struct vm_area_struct *vma, 448 unsigned long addr, unsigned long end, 449 struct zap_details *details); 450 void zap_page_range_single_batched(struct mmu_gather *tlb, 451 struct vm_area_struct *vma, unsigned long addr, 452 unsigned long size, struct zap_details *details); 453 int folio_unmap_invalidate(struct address_space *mapping, struct folio *folio, 454 gfp_t gfp); 455 456 void page_cache_ra_order(struct readahead_control *, struct file_ra_state *); 457 void force_page_cache_ra(struct readahead_control *, unsigned long nr); 458 static inline void force_page_cache_readahead(struct address_space *mapping, 459 struct file *file, pgoff_t index, unsigned long nr_to_read) 460 { 461 DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index); 462 force_page_cache_ra(&ractl, nr_to_read); 463 } 464 465 unsigned find_lock_entries(struct address_space *mapping, pgoff_t *start, 466 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices); 467 unsigned find_get_entries(struct address_space *mapping, pgoff_t *start, 468 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices); 469 void filemap_free_folio(struct address_space *mapping, struct folio *folio); 470 int truncate_inode_folio(struct address_space *mapping, struct folio *folio); 471 bool truncate_inode_partial_folio(struct folio *folio, loff_t start, 472 loff_t end); 473 long mapping_evict_folio(struct address_space *mapping, struct folio *folio); 474 unsigned long mapping_try_invalidate(struct address_space *mapping, 475 pgoff_t start, pgoff_t end, unsigned long *nr_failed); 476 477 /** 478 * folio_evictable - Test whether a folio is evictable. 479 * @folio: The folio to test. 480 * 481 * Test whether @folio is evictable -- i.e., should be placed on 482 * active/inactive lists vs unevictable list. 483 * 484 * Reasons folio might not be evictable: 485 * 1. folio's mapping marked unevictable 486 * 2. One of the pages in the folio is part of an mlocked VMA 487 */ 488 static inline bool folio_evictable(struct folio *folio) 489 { 490 bool ret; 491 492 /* Prevent address_space of inode and swap cache from being freed */ 493 rcu_read_lock(); 494 ret = !mapping_unevictable(folio_mapping(folio)) && 495 !folio_test_mlocked(folio); 496 rcu_read_unlock(); 497 return ret; 498 } 499 500 /* 501 * Turn a non-refcounted page (->_refcount == 0) into refcounted with 502 * a count of one. 503 */ 504 static inline void set_page_refcounted(struct page *page) 505 { 506 VM_BUG_ON_PAGE(PageTail(page), page); 507 VM_BUG_ON_PAGE(page_ref_count(page), page); 508 set_page_count(page, 1); 509 } 510 511 /* 512 * Return true if a folio needs ->release_folio() calling upon it. 513 */ 514 static inline bool folio_needs_release(struct folio *folio) 515 { 516 struct address_space *mapping = folio_mapping(folio); 517 518 return folio_has_private(folio) || 519 (mapping && mapping_release_always(mapping)); 520 } 521 522 extern unsigned long highest_memmap_pfn; 523 524 /* 525 * Maximum number of reclaim retries without progress before the OOM 526 * killer is consider the only way forward. 527 */ 528 #define MAX_RECLAIM_RETRIES 16 529 530 /* 531 * in mm/vmscan.c: 532 */ 533 bool folio_isolate_lru(struct folio *folio); 534 void folio_putback_lru(struct folio *folio); 535 extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason); 536 537 /* 538 * in mm/rmap.c: 539 */ 540 pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 541 542 /* 543 * in mm/page_alloc.c 544 */ 545 #define K(x) ((x) << (PAGE_SHIFT-10)) 546 547 extern char * const zone_names[MAX_NR_ZONES]; 548 549 /* perform sanity checks on struct pages being allocated or freed */ 550 DECLARE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled); 551 552 extern int min_free_kbytes; 553 extern int defrag_mode; 554 555 void setup_per_zone_wmarks(void); 556 void calculate_min_free_kbytes(void); 557 int __meminit init_per_zone_wmark_min(void); 558 void page_alloc_sysctl_init(void); 559 560 /* 561 * Structure for holding the mostly immutable allocation parameters passed 562 * between functions involved in allocations, including the alloc_pages* 563 * family of functions. 564 * 565 * nodemask, migratetype and highest_zoneidx are initialized only once in 566 * __alloc_pages() and then never change. 567 * 568 * zonelist, preferred_zone and highest_zoneidx are set first in 569 * __alloc_pages() for the fast path, and might be later changed 570 * in __alloc_pages_slowpath(). All other functions pass the whole structure 571 * by a const pointer. 572 */ 573 struct alloc_context { 574 struct zonelist *zonelist; 575 nodemask_t *nodemask; 576 struct zoneref *preferred_zoneref; 577 int migratetype; 578 579 /* 580 * highest_zoneidx represents highest usable zone index of 581 * the allocation request. Due to the nature of the zone, 582 * memory on lower zone than the highest_zoneidx will be 583 * protected by lowmem_reserve[highest_zoneidx]. 584 * 585 * highest_zoneidx is also used by reclaim/compaction to limit 586 * the target zone since higher zone than this index cannot be 587 * usable for this allocation request. 588 */ 589 enum zone_type highest_zoneidx; 590 bool spread_dirty_pages; 591 }; 592 593 /* 594 * This function returns the order of a free page in the buddy system. In 595 * general, page_zone(page)->lock must be held by the caller to prevent the 596 * page from being allocated in parallel and returning garbage as the order. 597 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 598 * page cannot be allocated or merged in parallel. Alternatively, it must 599 * handle invalid values gracefully, and use buddy_order_unsafe() below. 600 */ 601 static inline unsigned int buddy_order(struct page *page) 602 { 603 /* PageBuddy() must be checked by the caller */ 604 return page_private(page); 605 } 606 607 /* 608 * Like buddy_order(), but for callers who cannot afford to hold the zone lock. 609 * PageBuddy() should be checked first by the caller to minimize race window, 610 * and invalid values must be handled gracefully. 611 * 612 * READ_ONCE is used so that if the caller assigns the result into a local 613 * variable and e.g. tests it for valid range before using, the compiler cannot 614 * decide to remove the variable and inline the page_private(page) multiple 615 * times, potentially observing different values in the tests and the actual 616 * use of the result. 617 */ 618 #define buddy_order_unsafe(page) READ_ONCE(page_private(page)) 619 620 /* 621 * This function checks whether a page is free && is the buddy 622 * we can coalesce a page and its buddy if 623 * (a) the buddy is not in a hole (check before calling!) && 624 * (b) the buddy is in the buddy system && 625 * (c) a page and its buddy have the same order && 626 * (d) a page and its buddy are in the same zone. 627 * 628 * For recording whether a page is in the buddy system, we set PageBuddy. 629 * Setting, clearing, and testing PageBuddy is serialized by zone->lock. 630 * 631 * For recording page's order, we use page_private(page). 632 */ 633 static inline bool page_is_buddy(struct page *page, struct page *buddy, 634 unsigned int order) 635 { 636 if (!page_is_guard(buddy) && !PageBuddy(buddy)) 637 return false; 638 639 if (buddy_order(buddy) != order) 640 return false; 641 642 /* 643 * zone check is done late to avoid uselessly calculating 644 * zone/node ids for pages that could never merge. 645 */ 646 if (page_zone_id(page) != page_zone_id(buddy)) 647 return false; 648 649 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); 650 651 return true; 652 } 653 654 /* 655 * Locate the struct page for both the matching buddy in our 656 * pair (buddy1) and the combined O(n+1) page they form (page). 657 * 658 * 1) Any buddy B1 will have an order O twin B2 which satisfies 659 * the following equation: 660 * B2 = B1 ^ (1 << O) 661 * For example, if the starting buddy (buddy2) is #8 its order 662 * 1 buddy is #10: 663 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 664 * 665 * 2) Any buddy B will have an order O+1 parent P which 666 * satisfies the following equation: 667 * P = B & ~(1 << O) 668 * 669 * Assumption: *_mem_map is contiguous at least up to MAX_PAGE_ORDER 670 */ 671 static inline unsigned long 672 __find_buddy_pfn(unsigned long page_pfn, unsigned int order) 673 { 674 return page_pfn ^ (1 << order); 675 } 676 677 /* 678 * Find the buddy of @page and validate it. 679 * @page: The input page 680 * @pfn: The pfn of the page, it saves a call to page_to_pfn() when the 681 * function is used in the performance-critical __free_one_page(). 682 * @order: The order of the page 683 * @buddy_pfn: The output pointer to the buddy pfn, it also saves a call to 684 * page_to_pfn(). 685 * 686 * The found buddy can be a non PageBuddy, out of @page's zone, or its order is 687 * not the same as @page. The validation is necessary before use it. 688 * 689 * Return: the found buddy page or NULL if not found. 690 */ 691 static inline struct page *find_buddy_page_pfn(struct page *page, 692 unsigned long pfn, unsigned int order, unsigned long *buddy_pfn) 693 { 694 unsigned long __buddy_pfn = __find_buddy_pfn(pfn, order); 695 struct page *buddy; 696 697 buddy = page + (__buddy_pfn - pfn); 698 if (buddy_pfn) 699 *buddy_pfn = __buddy_pfn; 700 701 if (page_is_buddy(page, buddy, order)) 702 return buddy; 703 return NULL; 704 } 705 706 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn, 707 unsigned long end_pfn, struct zone *zone); 708 709 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn, 710 unsigned long end_pfn, struct zone *zone) 711 { 712 if (zone->contiguous) 713 return pfn_to_page(start_pfn); 714 715 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone); 716 } 717 718 void set_zone_contiguous(struct zone *zone); 719 bool pfn_range_intersects_zones(int nid, unsigned long start_pfn, 720 unsigned long nr_pages); 721 722 static inline void clear_zone_contiguous(struct zone *zone) 723 { 724 zone->contiguous = false; 725 } 726 727 extern int __isolate_free_page(struct page *page, unsigned int order); 728 extern void __putback_isolated_page(struct page *page, unsigned int order, 729 int mt); 730 extern void memblock_free_pages(struct page *page, unsigned long pfn, 731 unsigned int order); 732 extern void __free_pages_core(struct page *page, unsigned int order, 733 enum meminit_context context); 734 735 /* 736 * This will have no effect, other than possibly generating a warning, if the 737 * caller passes in a non-large folio. 738 */ 739 static inline void folio_set_order(struct folio *folio, unsigned int order) 740 { 741 if (WARN_ON_ONCE(!order || !folio_test_large(folio))) 742 return; 743 744 folio->_flags_1 = (folio->_flags_1 & ~0xffUL) | order; 745 #ifdef NR_PAGES_IN_LARGE_FOLIO 746 folio->_nr_pages = 1U << order; 747 #endif 748 } 749 750 bool __folio_unqueue_deferred_split(struct folio *folio); 751 static inline bool folio_unqueue_deferred_split(struct folio *folio) 752 { 753 if (folio_order(folio) <= 1 || !folio_test_large_rmappable(folio)) 754 return false; 755 756 /* 757 * At this point, there is no one trying to add the folio to 758 * deferred_list. If folio is not in deferred_list, it's safe 759 * to check without acquiring the split_queue_lock. 760 */ 761 if (data_race(list_empty(&folio->_deferred_list))) 762 return false; 763 764 return __folio_unqueue_deferred_split(folio); 765 } 766 767 static inline struct folio *page_rmappable_folio(struct page *page) 768 { 769 struct folio *folio = (struct folio *)page; 770 771 if (folio && folio_test_large(folio)) 772 folio_set_large_rmappable(folio); 773 return folio; 774 } 775 776 static inline void prep_compound_head(struct page *page, unsigned int order) 777 { 778 struct folio *folio = (struct folio *)page; 779 780 folio_set_order(folio, order); 781 atomic_set(&folio->_large_mapcount, -1); 782 if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) 783 atomic_set(&folio->_nr_pages_mapped, 0); 784 if (IS_ENABLED(CONFIG_MM_ID)) { 785 folio->_mm_ids = 0; 786 folio->_mm_id_mapcount[0] = -1; 787 folio->_mm_id_mapcount[1] = -1; 788 } 789 if (IS_ENABLED(CONFIG_64BIT) || order > 1) { 790 atomic_set(&folio->_pincount, 0); 791 atomic_set(&folio->_entire_mapcount, -1); 792 } 793 if (order > 1) 794 INIT_LIST_HEAD(&folio->_deferred_list); 795 } 796 797 static inline void prep_compound_tail(struct page *head, int tail_idx) 798 { 799 struct page *p = head + tail_idx; 800 801 p->mapping = TAIL_MAPPING; 802 set_compound_head(p, head); 803 set_page_private(p, 0); 804 } 805 806 void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags); 807 extern bool free_pages_prepare(struct page *page, unsigned int order); 808 809 extern int user_min_free_kbytes; 810 811 struct page *__alloc_frozen_pages_noprof(gfp_t, unsigned int order, int nid, 812 nodemask_t *); 813 #define __alloc_frozen_pages(...) \ 814 alloc_hooks(__alloc_frozen_pages_noprof(__VA_ARGS__)) 815 void free_frozen_pages(struct page *page, unsigned int order); 816 void free_unref_folios(struct folio_batch *fbatch); 817 818 #ifdef CONFIG_NUMA 819 struct page *alloc_frozen_pages_noprof(gfp_t, unsigned int order); 820 #else 821 static inline struct page *alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order) 822 { 823 return __alloc_frozen_pages_noprof(gfp, order, numa_node_id(), NULL); 824 } 825 #endif 826 827 #define alloc_frozen_pages(...) \ 828 alloc_hooks(alloc_frozen_pages_noprof(__VA_ARGS__)) 829 830 extern void zone_pcp_reset(struct zone *zone); 831 extern void zone_pcp_disable(struct zone *zone); 832 extern void zone_pcp_enable(struct zone *zone); 833 extern void zone_pcp_init(struct zone *zone); 834 835 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align, 836 phys_addr_t min_addr, 837 int nid, bool exact_nid); 838 839 void memmap_init_range(unsigned long, int, unsigned long, unsigned long, 840 unsigned long, enum meminit_context, struct vmem_altmap *, int, 841 bool); 842 843 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 844 845 /* 846 * in mm/compaction.c 847 */ 848 /* 849 * compact_control is used to track pages being migrated and the free pages 850 * they are being migrated to during memory compaction. The free_pfn starts 851 * at the end of a zone and migrate_pfn begins at the start. Movable pages 852 * are moved to the end of a zone during a compaction run and the run 853 * completes when free_pfn <= migrate_pfn 854 */ 855 struct compact_control { 856 struct list_head freepages[NR_PAGE_ORDERS]; /* List of free pages to migrate to */ 857 struct list_head migratepages; /* List of pages being migrated */ 858 unsigned int nr_freepages; /* Number of isolated free pages */ 859 unsigned int nr_migratepages; /* Number of pages to migrate */ 860 unsigned long free_pfn; /* isolate_freepages search base */ 861 /* 862 * Acts as an in/out parameter to page isolation for migration. 863 * isolate_migratepages uses it as a search base. 864 * isolate_migratepages_block will update the value to the next pfn 865 * after the last isolated one. 866 */ 867 unsigned long migrate_pfn; 868 unsigned long fast_start_pfn; /* a pfn to start linear scan from */ 869 struct zone *zone; 870 unsigned long total_migrate_scanned; 871 unsigned long total_free_scanned; 872 unsigned short fast_search_fail;/* failures to use free list searches */ 873 short search_order; /* order to start a fast search at */ 874 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 875 int order; /* order a direct compactor needs */ 876 int migratetype; /* migratetype of direct compactor */ 877 const unsigned int alloc_flags; /* alloc flags of a direct compactor */ 878 const int highest_zoneidx; /* zone index of a direct compactor */ 879 enum migrate_mode mode; /* Async or sync migration mode */ 880 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 881 bool no_set_skip_hint; /* Don't mark blocks for skipping */ 882 bool ignore_block_suitable; /* Scan blocks considered unsuitable */ 883 bool direct_compaction; /* False from kcompactd or /proc/... */ 884 bool proactive_compaction; /* kcompactd proactive compaction */ 885 bool whole_zone; /* Whole zone should/has been scanned */ 886 bool contended; /* Signal lock contention */ 887 bool finish_pageblock; /* Scan the remainder of a pageblock. Used 888 * when there are potentially transient 889 * isolation or migration failures to 890 * ensure forward progress. 891 */ 892 bool alloc_contig; /* alloc_contig_range allocation */ 893 }; 894 895 /* 896 * Used in direct compaction when a page should be taken from the freelists 897 * immediately when one is created during the free path. 898 */ 899 struct capture_control { 900 struct compact_control *cc; 901 struct page *page; 902 }; 903 904 unsigned long 905 isolate_freepages_range(struct compact_control *cc, 906 unsigned long start_pfn, unsigned long end_pfn); 907 int 908 isolate_migratepages_range(struct compact_control *cc, 909 unsigned long low_pfn, unsigned long end_pfn); 910 911 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */ 912 void init_cma_reserved_pageblock(struct page *page); 913 914 #endif /* CONFIG_COMPACTION || CONFIG_CMA */ 915 916 struct cma; 917 918 #ifdef CONFIG_CMA 919 void *cma_reserve_early(struct cma *cma, unsigned long size); 920 void init_cma_pageblock(struct page *page); 921 #else 922 static inline void *cma_reserve_early(struct cma *cma, unsigned long size) 923 { 924 return NULL; 925 } 926 static inline void init_cma_pageblock(struct page *page) 927 { 928 } 929 #endif 930 931 932 int find_suitable_fallback(struct free_area *area, unsigned int order, 933 int migratetype, bool claimable); 934 935 static inline bool free_area_empty(struct free_area *area, int migratetype) 936 { 937 return list_empty(&area->free_list[migratetype]); 938 } 939 940 /* mm/util.c */ 941 struct anon_vma *folio_anon_vma(const struct folio *folio); 942 943 #ifdef CONFIG_MMU 944 void unmap_mapping_folio(struct folio *folio); 945 extern long populate_vma_page_range(struct vm_area_struct *vma, 946 unsigned long start, unsigned long end, int *locked); 947 extern long faultin_page_range(struct mm_struct *mm, unsigned long start, 948 unsigned long end, bool write, int *locked); 949 extern bool mlock_future_ok(struct mm_struct *mm, vm_flags_t vm_flags, 950 unsigned long bytes); 951 952 /* 953 * NOTE: This function can't tell whether the folio is "fully mapped" in the 954 * range. 955 * "fully mapped" means all the pages of folio is associated with the page 956 * table of range while this function just check whether the folio range is 957 * within the range [start, end). Function caller needs to do page table 958 * check if it cares about the page table association. 959 * 960 * Typical usage (like mlock or madvise) is: 961 * Caller knows at least 1 page of folio is associated with page table of VMA 962 * and the range [start, end) is intersect with the VMA range. Caller wants 963 * to know whether the folio is fully associated with the range. It calls 964 * this function to check whether the folio is in the range first. Then checks 965 * the page table to know whether the folio is fully mapped to the range. 966 */ 967 static inline bool 968 folio_within_range(struct folio *folio, struct vm_area_struct *vma, 969 unsigned long start, unsigned long end) 970 { 971 pgoff_t pgoff, addr; 972 unsigned long vma_pglen = vma_pages(vma); 973 974 VM_WARN_ON_FOLIO(folio_test_ksm(folio), folio); 975 if (start > end) 976 return false; 977 978 if (start < vma->vm_start) 979 start = vma->vm_start; 980 981 if (end > vma->vm_end) 982 end = vma->vm_end; 983 984 pgoff = folio_pgoff(folio); 985 986 /* if folio start address is not in vma range */ 987 if (!in_range(pgoff, vma->vm_pgoff, vma_pglen)) 988 return false; 989 990 addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 991 992 return !(addr < start || end - addr < folio_size(folio)); 993 } 994 995 static inline bool 996 folio_within_vma(struct folio *folio, struct vm_area_struct *vma) 997 { 998 return folio_within_range(folio, vma, vma->vm_start, vma->vm_end); 999 } 1000 1001 /* 1002 * mlock_vma_folio() and munlock_vma_folio(): 1003 * should be called with vma's mmap_lock held for read or write, 1004 * under page table lock for the pte/pmd being added or removed. 1005 * 1006 * mlock is usually called at the end of folio_add_*_rmap_*(), munlock at 1007 * the end of folio_remove_rmap_*(); but new anon folios are managed by 1008 * folio_add_lru_vma() calling mlock_new_folio(). 1009 */ 1010 void mlock_folio(struct folio *folio); 1011 static inline void mlock_vma_folio(struct folio *folio, 1012 struct vm_area_struct *vma) 1013 { 1014 /* 1015 * The VM_SPECIAL check here serves two purposes. 1016 * 1) VM_IO check prevents migration from double-counting during mlock. 1017 * 2) Although mmap_region() and mlock_fixup() take care that VM_LOCKED 1018 * is never left set on a VM_SPECIAL vma, there is an interval while 1019 * file->f_op->mmap() is using vm_insert_page(s), when VM_LOCKED may 1020 * still be set while VM_SPECIAL bits are added: so ignore it then. 1021 */ 1022 if (unlikely((vma->vm_flags & (VM_LOCKED|VM_SPECIAL)) == VM_LOCKED)) 1023 mlock_folio(folio); 1024 } 1025 1026 void munlock_folio(struct folio *folio); 1027 static inline void munlock_vma_folio(struct folio *folio, 1028 struct vm_area_struct *vma) 1029 { 1030 /* 1031 * munlock if the function is called. Ideally, we should only 1032 * do munlock if any page of folio is unmapped from VMA and 1033 * cause folio not fully mapped to VMA. 1034 * 1035 * But it's not easy to confirm that's the situation. So we 1036 * always munlock the folio and page reclaim will correct it 1037 * if it's wrong. 1038 */ 1039 if (unlikely(vma->vm_flags & VM_LOCKED)) 1040 munlock_folio(folio); 1041 } 1042 1043 void mlock_new_folio(struct folio *folio); 1044 bool need_mlock_drain(int cpu); 1045 void mlock_drain_local(void); 1046 void mlock_drain_remote(int cpu); 1047 1048 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 1049 1050 /** 1051 * vma_address - Find the virtual address a page range is mapped at 1052 * @vma: The vma which maps this object. 1053 * @pgoff: The page offset within its object. 1054 * @nr_pages: The number of pages to consider. 1055 * 1056 * If any page in this range is mapped by this VMA, return the first address 1057 * where any of these pages appear. Otherwise, return -EFAULT. 1058 */ 1059 static inline unsigned long vma_address(const struct vm_area_struct *vma, 1060 pgoff_t pgoff, unsigned long nr_pages) 1061 { 1062 unsigned long address; 1063 1064 if (pgoff >= vma->vm_pgoff) { 1065 address = vma->vm_start + 1066 ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 1067 /* Check for address beyond vma (or wrapped through 0?) */ 1068 if (address < vma->vm_start || address >= vma->vm_end) 1069 address = -EFAULT; 1070 } else if (pgoff + nr_pages - 1 >= vma->vm_pgoff) { 1071 /* Test above avoids possibility of wrap to 0 on 32-bit */ 1072 address = vma->vm_start; 1073 } else { 1074 address = -EFAULT; 1075 } 1076 return address; 1077 } 1078 1079 /* 1080 * Then at what user virtual address will none of the range be found in vma? 1081 * Assumes that vma_address() already returned a good starting address. 1082 */ 1083 static inline unsigned long vma_address_end(struct page_vma_mapped_walk *pvmw) 1084 { 1085 struct vm_area_struct *vma = pvmw->vma; 1086 pgoff_t pgoff; 1087 unsigned long address; 1088 1089 /* Common case, plus ->pgoff is invalid for KSM */ 1090 if (pvmw->nr_pages == 1) 1091 return pvmw->address + PAGE_SIZE; 1092 1093 pgoff = pvmw->pgoff + pvmw->nr_pages; 1094 address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 1095 /* Check for address beyond vma (or wrapped through 0?) */ 1096 if (address < vma->vm_start || address > vma->vm_end) 1097 address = vma->vm_end; 1098 return address; 1099 } 1100 1101 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, 1102 struct file *fpin) 1103 { 1104 int flags = vmf->flags; 1105 1106 if (fpin) 1107 return fpin; 1108 1109 /* 1110 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or 1111 * anything, so we only pin the file and drop the mmap_lock if only 1112 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt. 1113 */ 1114 if (fault_flag_allow_retry_first(flags) && 1115 !(flags & FAULT_FLAG_RETRY_NOWAIT)) { 1116 fpin = get_file(vmf->vma->vm_file); 1117 release_fault_lock(vmf); 1118 } 1119 return fpin; 1120 } 1121 #else /* !CONFIG_MMU */ 1122 static inline void unmap_mapping_folio(struct folio *folio) { } 1123 static inline void mlock_new_folio(struct folio *folio) { } 1124 static inline bool need_mlock_drain(int cpu) { return false; } 1125 static inline void mlock_drain_local(void) { } 1126 static inline void mlock_drain_remote(int cpu) { } 1127 static inline void vunmap_range_noflush(unsigned long start, unsigned long end) 1128 { 1129 } 1130 #endif /* !CONFIG_MMU */ 1131 1132 /* Memory initialisation debug and verification */ 1133 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 1134 DECLARE_STATIC_KEY_TRUE(deferred_pages); 1135 1136 bool __init deferred_grow_zone(struct zone *zone, unsigned int order); 1137 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 1138 1139 void init_deferred_page(unsigned long pfn, int nid); 1140 1141 enum mminit_level { 1142 MMINIT_WARNING, 1143 MMINIT_VERIFY, 1144 MMINIT_TRACE 1145 }; 1146 1147 #ifdef CONFIG_DEBUG_MEMORY_INIT 1148 1149 extern int mminit_loglevel; 1150 1151 #define mminit_dprintk(level, prefix, fmt, arg...) \ 1152 do { \ 1153 if (level < mminit_loglevel) { \ 1154 if (level <= MMINIT_WARNING) \ 1155 pr_warn("mminit::" prefix " " fmt, ##arg); \ 1156 else \ 1157 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 1158 } \ 1159 } while (0) 1160 1161 extern void mminit_verify_pageflags_layout(void); 1162 extern void mminit_verify_zonelist(void); 1163 #else 1164 1165 static inline void mminit_dprintk(enum mminit_level level, 1166 const char *prefix, const char *fmt, ...) 1167 { 1168 } 1169 1170 static inline void mminit_verify_pageflags_layout(void) 1171 { 1172 } 1173 1174 static inline void mminit_verify_zonelist(void) 1175 { 1176 } 1177 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 1178 1179 #define NODE_RECLAIM_NOSCAN -2 1180 #define NODE_RECLAIM_FULL -1 1181 #define NODE_RECLAIM_SOME 0 1182 #define NODE_RECLAIM_SUCCESS 1 1183 1184 #ifdef CONFIG_NUMA 1185 extern int node_reclaim_mode; 1186 1187 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); 1188 extern int find_next_best_node(int node, nodemask_t *used_node_mask); 1189 #else 1190 #define node_reclaim_mode 0 1191 1192 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, 1193 unsigned int order) 1194 { 1195 return NODE_RECLAIM_NOSCAN; 1196 } 1197 static inline int find_next_best_node(int node, nodemask_t *used_node_mask) 1198 { 1199 return NUMA_NO_NODE; 1200 } 1201 #endif 1202 1203 static inline bool node_reclaim_enabled(void) 1204 { 1205 /* Is any node_reclaim_mode bit set? */ 1206 return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP); 1207 } 1208 1209 /* 1210 * mm/memory-failure.c 1211 */ 1212 #ifdef CONFIG_MEMORY_FAILURE 1213 int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill); 1214 void shake_folio(struct folio *folio); 1215 extern int hwpoison_filter(struct page *p); 1216 1217 extern u32 hwpoison_filter_dev_major; 1218 extern u32 hwpoison_filter_dev_minor; 1219 extern u64 hwpoison_filter_flags_mask; 1220 extern u64 hwpoison_filter_flags_value; 1221 extern u64 hwpoison_filter_memcg; 1222 extern u32 hwpoison_filter_enable; 1223 #define MAGIC_HWPOISON 0x48575053U /* HWPS */ 1224 void SetPageHWPoisonTakenOff(struct page *page); 1225 void ClearPageHWPoisonTakenOff(struct page *page); 1226 bool take_page_off_buddy(struct page *page); 1227 bool put_page_back_buddy(struct page *page); 1228 struct task_struct *task_early_kill(struct task_struct *tsk, int force_early); 1229 void add_to_kill_ksm(struct task_struct *tsk, const struct page *p, 1230 struct vm_area_struct *vma, struct list_head *to_kill, 1231 unsigned long ksm_addr); 1232 unsigned long page_mapped_in_vma(const struct page *page, 1233 struct vm_area_struct *vma); 1234 1235 #else 1236 static inline int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill) 1237 { 1238 return -EBUSY; 1239 } 1240 #endif 1241 1242 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 1243 unsigned long, unsigned long, 1244 unsigned long, unsigned long); 1245 1246 extern void set_pageblock_order(void); 1247 unsigned long reclaim_pages(struct list_head *folio_list); 1248 unsigned int reclaim_clean_pages_from_list(struct zone *zone, 1249 struct list_head *folio_list); 1250 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 1251 #define ALLOC_WMARK_MIN WMARK_MIN 1252 #define ALLOC_WMARK_LOW WMARK_LOW 1253 #define ALLOC_WMARK_HIGH WMARK_HIGH 1254 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 1255 1256 /* Mask to get the watermark bits */ 1257 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 1258 1259 /* 1260 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we 1261 * cannot assume a reduced access to memory reserves is sufficient for 1262 * !MMU 1263 */ 1264 #ifdef CONFIG_MMU 1265 #define ALLOC_OOM 0x08 1266 #else 1267 #define ALLOC_OOM ALLOC_NO_WATERMARKS 1268 #endif 1269 1270 #define ALLOC_NON_BLOCK 0x10 /* Caller cannot block. Allow access 1271 * to 25% of the min watermark or 1272 * 62.5% if __GFP_HIGH is set. 1273 */ 1274 #define ALLOC_MIN_RESERVE 0x20 /* __GFP_HIGH set. Allow access to 50% 1275 * of the min watermark. 1276 */ 1277 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1278 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 1279 #ifdef CONFIG_ZONE_DMA32 1280 #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */ 1281 #else 1282 #define ALLOC_NOFRAGMENT 0x0 1283 #endif 1284 #define ALLOC_HIGHATOMIC 0x200 /* Allows access to MIGRATE_HIGHATOMIC */ 1285 #define ALLOC_TRYLOCK 0x400 /* Only use spin_trylock in allocation path */ 1286 #define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */ 1287 1288 /* Flags that allow allocations below the min watermark. */ 1289 #define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM) 1290 1291 enum ttu_flags; 1292 struct tlbflush_unmap_batch; 1293 1294 1295 /* 1296 * only for MM internal work items which do not depend on 1297 * any allocations or locks which might depend on allocations 1298 */ 1299 extern struct workqueue_struct *mm_percpu_wq; 1300 1301 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 1302 void try_to_unmap_flush(void); 1303 void try_to_unmap_flush_dirty(void); 1304 void flush_tlb_batched_pending(struct mm_struct *mm); 1305 #else 1306 static inline void try_to_unmap_flush(void) 1307 { 1308 } 1309 static inline void try_to_unmap_flush_dirty(void) 1310 { 1311 } 1312 static inline void flush_tlb_batched_pending(struct mm_struct *mm) 1313 { 1314 } 1315 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 1316 1317 extern const struct trace_print_flags pageflag_names[]; 1318 extern const struct trace_print_flags vmaflag_names[]; 1319 extern const struct trace_print_flags gfpflag_names[]; 1320 1321 static inline bool is_migrate_highatomic(enum migratetype migratetype) 1322 { 1323 return migratetype == MIGRATE_HIGHATOMIC; 1324 } 1325 1326 void setup_zone_pageset(struct zone *zone); 1327 1328 struct migration_target_control { 1329 int nid; /* preferred node id */ 1330 nodemask_t *nmask; 1331 gfp_t gfp_mask; 1332 enum migrate_reason reason; 1333 }; 1334 1335 /* 1336 * mm/filemap.c 1337 */ 1338 size_t splice_folio_into_pipe(struct pipe_inode_info *pipe, 1339 struct folio *folio, loff_t fpos, size_t size); 1340 1341 /* 1342 * mm/vmalloc.c 1343 */ 1344 #ifdef CONFIG_MMU 1345 void __init vmalloc_init(void); 1346 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end, 1347 pgprot_t prot, struct page **pages, unsigned int page_shift); 1348 unsigned int get_vm_area_page_order(struct vm_struct *vm); 1349 #else 1350 static inline void vmalloc_init(void) 1351 { 1352 } 1353 1354 static inline 1355 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end, 1356 pgprot_t prot, struct page **pages, unsigned int page_shift) 1357 { 1358 return -EINVAL; 1359 } 1360 #endif 1361 1362 int __must_check __vmap_pages_range_noflush(unsigned long addr, 1363 unsigned long end, pgprot_t prot, 1364 struct page **pages, unsigned int page_shift); 1365 1366 void vunmap_range_noflush(unsigned long start, unsigned long end); 1367 1368 void __vunmap_range_noflush(unsigned long start, unsigned long end); 1369 1370 int numa_migrate_check(struct folio *folio, struct vm_fault *vmf, 1371 unsigned long addr, int *flags, bool writable, 1372 int *last_cpupid); 1373 1374 void free_zone_device_folio(struct folio *folio); 1375 int migrate_device_coherent_folio(struct folio *folio); 1376 1377 struct vm_struct *__get_vm_area_node(unsigned long size, 1378 unsigned long align, unsigned long shift, 1379 vm_flags_t vm_flags, unsigned long start, 1380 unsigned long end, int node, gfp_t gfp_mask, 1381 const void *caller); 1382 1383 /* 1384 * mm/gup.c 1385 */ 1386 int __must_check try_grab_folio(struct folio *folio, int refs, 1387 unsigned int flags); 1388 1389 /* 1390 * mm/huge_memory.c 1391 */ 1392 void touch_pud(struct vm_area_struct *vma, unsigned long addr, 1393 pud_t *pud, bool write); 1394 void touch_pmd(struct vm_area_struct *vma, unsigned long addr, 1395 pmd_t *pmd, bool write); 1396 1397 /* 1398 * Parses a string with mem suffixes into its order. Useful to parse kernel 1399 * parameters. 1400 */ 1401 static inline int get_order_from_str(const char *size_str, 1402 unsigned long valid_orders) 1403 { 1404 unsigned long size; 1405 char *endptr; 1406 int order; 1407 1408 size = memparse(size_str, &endptr); 1409 1410 if (!is_power_of_2(size)) 1411 return -EINVAL; 1412 order = get_order(size); 1413 if (BIT(order) & ~valid_orders) 1414 return -EINVAL; 1415 1416 return order; 1417 } 1418 1419 enum { 1420 /* mark page accessed */ 1421 FOLL_TOUCH = 1 << 16, 1422 /* a retry, previous pass started an IO */ 1423 FOLL_TRIED = 1 << 17, 1424 /* we are working on non-current tsk/mm */ 1425 FOLL_REMOTE = 1 << 18, 1426 /* pages must be released via unpin_user_page */ 1427 FOLL_PIN = 1 << 19, 1428 /* gup_fast: prevent fall-back to slow gup */ 1429 FOLL_FAST_ONLY = 1 << 20, 1430 /* allow unlocking the mmap lock */ 1431 FOLL_UNLOCKABLE = 1 << 21, 1432 /* VMA lookup+checks compatible with MADV_POPULATE_(READ|WRITE) */ 1433 FOLL_MADV_POPULATE = 1 << 22, 1434 }; 1435 1436 #define INTERNAL_GUP_FLAGS (FOLL_TOUCH | FOLL_TRIED | FOLL_REMOTE | FOLL_PIN | \ 1437 FOLL_FAST_ONLY | FOLL_UNLOCKABLE | \ 1438 FOLL_MADV_POPULATE) 1439 1440 /* 1441 * Indicates for which pages that are write-protected in the page table, 1442 * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that the 1443 * GUP pin will remain consistent with the pages mapped into the page tables 1444 * of the MM. 1445 * 1446 * Temporary unmapping of PageAnonExclusive() pages or clearing of 1447 * PageAnonExclusive() has to protect against concurrent GUP: 1448 * * Ordinary GUP: Using the PT lock 1449 * * GUP-fast and fork(): mm->write_protect_seq 1450 * * GUP-fast and KSM or temporary unmapping (swap, migration): see 1451 * folio_try_share_anon_rmap_*() 1452 * 1453 * Must be called with the (sub)page that's actually referenced via the 1454 * page table entry, which might not necessarily be the head page for a 1455 * PTE-mapped THP. 1456 * 1457 * If the vma is NULL, we're coming from the GUP-fast path and might have 1458 * to fallback to the slow path just to lookup the vma. 1459 */ 1460 static inline bool gup_must_unshare(struct vm_area_struct *vma, 1461 unsigned int flags, struct page *page) 1462 { 1463 /* 1464 * FOLL_WRITE is implicitly handled correctly as the page table entry 1465 * has to be writable -- and if it references (part of) an anonymous 1466 * folio, that part is required to be marked exclusive. 1467 */ 1468 if ((flags & (FOLL_WRITE | FOLL_PIN)) != FOLL_PIN) 1469 return false; 1470 /* 1471 * Note: PageAnon(page) is stable until the page is actually getting 1472 * freed. 1473 */ 1474 if (!PageAnon(page)) { 1475 /* 1476 * We only care about R/O long-term pining: R/O short-term 1477 * pinning does not have the semantics to observe successive 1478 * changes through the process page tables. 1479 */ 1480 if (!(flags & FOLL_LONGTERM)) 1481 return false; 1482 1483 /* We really need the vma ... */ 1484 if (!vma) 1485 return true; 1486 1487 /* 1488 * ... because we only care about writable private ("COW") 1489 * mappings where we have to break COW early. 1490 */ 1491 return is_cow_mapping(vma->vm_flags); 1492 } 1493 1494 /* Paired with a memory barrier in folio_try_share_anon_rmap_*(). */ 1495 if (IS_ENABLED(CONFIG_HAVE_GUP_FAST)) 1496 smp_rmb(); 1497 1498 /* 1499 * Note that KSM pages cannot be exclusive, and consequently, 1500 * cannot get pinned. 1501 */ 1502 return !PageAnonExclusive(page); 1503 } 1504 1505 extern bool mirrored_kernelcore; 1506 bool memblock_has_mirror(void); 1507 void memblock_free_all(void); 1508 1509 static __always_inline void vma_set_range(struct vm_area_struct *vma, 1510 unsigned long start, unsigned long end, 1511 pgoff_t pgoff) 1512 { 1513 vma->vm_start = start; 1514 vma->vm_end = end; 1515 vma->vm_pgoff = pgoff; 1516 } 1517 1518 static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma) 1519 { 1520 /* 1521 * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty 1522 * enablements, because when without soft-dirty being compiled in, 1523 * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY) 1524 * will be constantly true. 1525 */ 1526 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) 1527 return false; 1528 1529 /* 1530 * Soft-dirty is kind of special: its tracking is enabled when the 1531 * vma flags not set. 1532 */ 1533 return !(vma->vm_flags & VM_SOFTDIRTY); 1534 } 1535 1536 static inline bool pmd_needs_soft_dirty_wp(struct vm_area_struct *vma, pmd_t pmd) 1537 { 1538 return vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd); 1539 } 1540 1541 static inline bool pte_needs_soft_dirty_wp(struct vm_area_struct *vma, pte_t pte) 1542 { 1543 return vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte); 1544 } 1545 1546 void __meminit __init_single_page(struct page *page, unsigned long pfn, 1547 unsigned long zone, int nid); 1548 void __meminit __init_page_from_nid(unsigned long pfn, int nid); 1549 1550 /* shrinker related functions */ 1551 unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg, 1552 int priority); 1553 1554 #ifdef CONFIG_SHRINKER_DEBUG 1555 static inline __printf(2, 0) int shrinker_debugfs_name_alloc( 1556 struct shrinker *shrinker, const char *fmt, va_list ap) 1557 { 1558 shrinker->name = kvasprintf_const(GFP_KERNEL, fmt, ap); 1559 1560 return shrinker->name ? 0 : -ENOMEM; 1561 } 1562 1563 static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) 1564 { 1565 kfree_const(shrinker->name); 1566 shrinker->name = NULL; 1567 } 1568 1569 extern int shrinker_debugfs_add(struct shrinker *shrinker); 1570 extern struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, 1571 int *debugfs_id); 1572 extern void shrinker_debugfs_remove(struct dentry *debugfs_entry, 1573 int debugfs_id); 1574 #else /* CONFIG_SHRINKER_DEBUG */ 1575 static inline int shrinker_debugfs_add(struct shrinker *shrinker) 1576 { 1577 return 0; 1578 } 1579 static inline int shrinker_debugfs_name_alloc(struct shrinker *shrinker, 1580 const char *fmt, va_list ap) 1581 { 1582 return 0; 1583 } 1584 static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) 1585 { 1586 } 1587 static inline struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, 1588 int *debugfs_id) 1589 { 1590 *debugfs_id = -1; 1591 return NULL; 1592 } 1593 static inline void shrinker_debugfs_remove(struct dentry *debugfs_entry, 1594 int debugfs_id) 1595 { 1596 } 1597 #endif /* CONFIG_SHRINKER_DEBUG */ 1598 1599 /* Only track the nodes of mappings with shadow entries */ 1600 void workingset_update_node(struct xa_node *node); 1601 extern struct list_lru shadow_nodes; 1602 #define mapping_set_update(xas, mapping) do { \ 1603 if (!dax_mapping(mapping) && !shmem_mapping(mapping)) { \ 1604 xas_set_update(xas, workingset_update_node); \ 1605 xas_set_lru(xas, &shadow_nodes); \ 1606 } \ 1607 } while (0) 1608 1609 /* mremap.c */ 1610 unsigned long move_page_tables(struct pagetable_move_control *pmc); 1611 1612 #ifdef CONFIG_UNACCEPTED_MEMORY 1613 void accept_page(struct page *page); 1614 #else /* CONFIG_UNACCEPTED_MEMORY */ 1615 static inline void accept_page(struct page *page) 1616 { 1617 } 1618 #endif /* CONFIG_UNACCEPTED_MEMORY */ 1619 1620 /* pagewalk.c */ 1621 int walk_page_range_mm(struct mm_struct *mm, unsigned long start, 1622 unsigned long end, const struct mm_walk_ops *ops, 1623 void *private); 1624 int walk_page_range_debug(struct mm_struct *mm, unsigned long start, 1625 unsigned long end, const struct mm_walk_ops *ops, 1626 pgd_t *pgd, void *private); 1627 1628 /* pt_reclaim.c */ 1629 bool try_get_and_clear_pmd(struct mm_struct *mm, pmd_t *pmd, pmd_t *pmdval); 1630 void free_pte(struct mm_struct *mm, unsigned long addr, struct mmu_gather *tlb, 1631 pmd_t pmdval); 1632 void try_to_free_pte(struct mm_struct *mm, pmd_t *pmd, unsigned long addr, 1633 struct mmu_gather *tlb); 1634 1635 #ifdef CONFIG_PT_RECLAIM 1636 bool reclaim_pt_is_enabled(unsigned long start, unsigned long end, 1637 struct zap_details *details); 1638 #else 1639 static inline bool reclaim_pt_is_enabled(unsigned long start, unsigned long end, 1640 struct zap_details *details) 1641 { 1642 return false; 1643 } 1644 #endif /* CONFIG_PT_RECLAIM */ 1645 1646 void dup_mm_exe_file(struct mm_struct *mm, struct mm_struct *oldmm); 1647 int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm); 1648 1649 #endif /* __MM_INTERNAL_H */ 1650