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/leafops.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 = vfs_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 must 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 /* unmap_vmas is in mm/memory.c */ 201 void unmap_vmas(struct mmu_gather *tlb, struct unmap_desc *unmap); 202 203 #ifdef CONFIG_MMU 204 205 static inline void get_anon_vma(struct anon_vma *anon_vma) 206 { 207 atomic_inc(&anon_vma->refcount); 208 } 209 210 void __put_anon_vma(struct anon_vma *anon_vma); 211 212 static inline void put_anon_vma(struct anon_vma *anon_vma) 213 { 214 if (atomic_dec_and_test(&anon_vma->refcount)) 215 __put_anon_vma(anon_vma); 216 } 217 218 static inline void anon_vma_lock_write(struct anon_vma *anon_vma) 219 { 220 down_write(&anon_vma->root->rwsem); 221 } 222 223 static inline int anon_vma_trylock_write(struct anon_vma *anon_vma) 224 { 225 return down_write_trylock(&anon_vma->root->rwsem); 226 } 227 228 static inline void anon_vma_unlock_write(struct anon_vma *anon_vma) 229 { 230 up_write(&anon_vma->root->rwsem); 231 } 232 233 static inline void anon_vma_lock_read(struct anon_vma *anon_vma) 234 { 235 down_read(&anon_vma->root->rwsem); 236 } 237 238 static inline int anon_vma_trylock_read(struct anon_vma *anon_vma) 239 { 240 return down_read_trylock(&anon_vma->root->rwsem); 241 } 242 243 static inline void anon_vma_unlock_read(struct anon_vma *anon_vma) 244 { 245 up_read(&anon_vma->root->rwsem); 246 } 247 248 struct anon_vma *folio_get_anon_vma(const struct folio *folio); 249 250 /* Operations which modify VMAs. */ 251 enum vma_operation { 252 VMA_OP_SPLIT, 253 VMA_OP_MERGE_UNFAULTED, 254 VMA_OP_REMAP, 255 VMA_OP_FORK, 256 }; 257 258 int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src, 259 enum vma_operation operation); 260 int anon_vma_fork(struct vm_area_struct *vma, struct vm_area_struct *pvma); 261 int __anon_vma_prepare(struct vm_area_struct *vma); 262 void unlink_anon_vmas(struct vm_area_struct *vma); 263 264 static inline int anon_vma_prepare(struct vm_area_struct *vma) 265 { 266 if (likely(vma->anon_vma)) 267 return 0; 268 269 return __anon_vma_prepare(vma); 270 } 271 272 /* Flags for folio_pte_batch(). */ 273 typedef int __bitwise fpb_t; 274 275 /* Compare PTEs respecting the dirty bit. */ 276 #define FPB_RESPECT_DIRTY ((__force fpb_t)BIT(0)) 277 278 /* Compare PTEs respecting the soft-dirty bit. */ 279 #define FPB_RESPECT_SOFT_DIRTY ((__force fpb_t)BIT(1)) 280 281 /* Compare PTEs respecting the writable bit. */ 282 #define FPB_RESPECT_WRITE ((__force fpb_t)BIT(2)) 283 284 /* 285 * Merge PTE write bits: if any PTE in the batch is writable, modify the 286 * PTE at @ptentp to be writable. 287 */ 288 #define FPB_MERGE_WRITE ((__force fpb_t)BIT(3)) 289 290 /* 291 * Merge PTE young and dirty bits: if any PTE in the batch is young or dirty, 292 * modify the PTE at @ptentp to be young or dirty, respectively. 293 */ 294 #define FPB_MERGE_YOUNG_DIRTY ((__force fpb_t)BIT(4)) 295 296 static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags) 297 { 298 if (!(flags & FPB_RESPECT_DIRTY)) 299 pte = pte_mkclean(pte); 300 if (likely(!(flags & FPB_RESPECT_SOFT_DIRTY))) 301 pte = pte_clear_soft_dirty(pte); 302 if (likely(!(flags & FPB_RESPECT_WRITE))) 303 pte = pte_wrprotect(pte); 304 return pte_mkold(pte); 305 } 306 307 /** 308 * folio_pte_batch_flags - detect a PTE batch for a large folio 309 * @folio: The large folio to detect a PTE batch for. 310 * @vma: The VMA. Only relevant with FPB_MERGE_WRITE, otherwise can be NULL. 311 * @ptep: Page table pointer for the first entry. 312 * @ptentp: Pointer to a COPY of the first page table entry whose flags this 313 * function updates based on @flags if appropriate. 314 * @max_nr: The maximum number of table entries to consider. 315 * @flags: Flags to modify the PTE batch semantics. 316 * 317 * Detect a PTE batch: consecutive (present) PTEs that map consecutive 318 * pages of the same large folio in a single VMA and a single page table. 319 * 320 * All PTEs inside a PTE batch have the same PTE bits set, excluding the PFN, 321 * the accessed bit, writable bit, dirty bit (unless FPB_RESPECT_DIRTY is set) 322 * and soft-dirty bit (unless FPB_RESPECT_SOFT_DIRTY is set). 323 * 324 * @ptep must map any page of the folio. max_nr must be at least one and 325 * must be limited by the caller so scanning cannot exceed a single VMA and 326 * a single page table. 327 * 328 * Depending on the FPB_MERGE_* flags, the pte stored at @ptentp will 329 * be updated: it's crucial that a pointer to a COPY of the first 330 * page table entry, obtained through ptep_get(), is provided as @ptentp. 331 * 332 * This function will be inlined to optimize based on the input parameters; 333 * consider using folio_pte_batch() instead if applicable. 334 * 335 * Return: the number of table entries in the batch. 336 */ 337 static inline unsigned int folio_pte_batch_flags(struct folio *folio, 338 struct vm_area_struct *vma, pte_t *ptep, pte_t *ptentp, 339 unsigned int max_nr, fpb_t flags) 340 { 341 bool any_writable = false, any_young = false, any_dirty = false; 342 pte_t expected_pte, pte = *ptentp; 343 unsigned int nr, cur_nr; 344 345 VM_WARN_ON_FOLIO(!pte_present(pte), folio); 346 VM_WARN_ON_FOLIO(!folio_test_large(folio) || max_nr < 1, folio); 347 VM_WARN_ON_FOLIO(page_folio(pfn_to_page(pte_pfn(pte))) != folio, folio); 348 /* 349 * Ensure this is a pointer to a copy not a pointer into a page table. 350 * If this is a stack value, it won't be a valid virtual address, but 351 * that's fine because it also cannot be pointing into the page table. 352 */ 353 VM_WARN_ON(virt_addr_valid(ptentp) && PageTable(virt_to_page(ptentp))); 354 355 /* Limit max_nr to the actual remaining PFNs in the folio we could batch. */ 356 max_nr = min_t(unsigned long, max_nr, 357 folio_pfn(folio) + folio_nr_pages(folio) - pte_pfn(pte)); 358 359 nr = pte_batch_hint(ptep, pte); 360 expected_pte = __pte_batch_clear_ignored(pte_advance_pfn(pte, nr), flags); 361 ptep = ptep + nr; 362 363 while (nr < max_nr) { 364 pte = ptep_get(ptep); 365 366 if (!pte_same(__pte_batch_clear_ignored(pte, flags), expected_pte)) 367 break; 368 369 if (flags & FPB_MERGE_WRITE) 370 any_writable |= pte_write(pte); 371 if (flags & FPB_MERGE_YOUNG_DIRTY) { 372 any_young |= pte_young(pte); 373 any_dirty |= pte_dirty(pte); 374 } 375 376 cur_nr = pte_batch_hint(ptep, pte); 377 expected_pte = pte_advance_pfn(expected_pte, cur_nr); 378 ptep += cur_nr; 379 nr += cur_nr; 380 } 381 382 if (any_writable) 383 *ptentp = pte_mkwrite(*ptentp, vma); 384 if (any_young) 385 *ptentp = pte_mkyoung(*ptentp); 386 if (any_dirty) 387 *ptentp = pte_mkdirty(*ptentp); 388 389 return min(nr, max_nr); 390 } 391 392 unsigned int folio_pte_batch(struct folio *folio, pte_t *ptep, pte_t pte, 393 unsigned int max_nr); 394 395 /** 396 * pte_move_swp_offset - Move the swap entry offset field of a swap pte 397 * forward or backward by delta 398 * @pte: The initial pte state; must be a swap entry 399 * @delta: The direction and the offset we are moving; forward if delta 400 * is positive; backward if delta is negative 401 * 402 * Moves the swap offset, while maintaining all other fields, including 403 * swap type, and any swp pte bits. The resulting pte is returned. 404 */ 405 static inline pte_t pte_move_swp_offset(pte_t pte, long delta) 406 { 407 const softleaf_t entry = softleaf_from_pte(pte); 408 pte_t new = __swp_entry_to_pte(__swp_entry(swp_type(entry), 409 (swp_offset(entry) + delta))); 410 411 if (pte_swp_soft_dirty(pte)) 412 new = pte_swp_mksoft_dirty(new); 413 if (pte_swp_exclusive(pte)) 414 new = pte_swp_mkexclusive(new); 415 if (pte_swp_uffd_wp(pte)) 416 new = pte_swp_mkuffd_wp(new); 417 418 return new; 419 } 420 421 422 /** 423 * pte_next_swp_offset - Increment the swap entry offset field of a swap pte. 424 * @pte: The initial pte state; must be a swap entry. 425 * 426 * Increments the swap offset, while maintaining all other fields, including 427 * swap type, and any swp pte bits. The resulting pte is returned. 428 */ 429 static inline pte_t pte_next_swp_offset(pte_t pte) 430 { 431 return pte_move_swp_offset(pte, 1); 432 } 433 434 /** 435 * swap_pte_batch - detect a PTE batch for a set of contiguous swap entries 436 * @start_ptep: Page table pointer for the first entry. 437 * @max_nr: The maximum number of table entries to consider. 438 * @pte: Page table entry for the first entry. 439 * 440 * Detect a batch of contiguous swap entries: consecutive (non-present) PTEs 441 * containing swap entries all with consecutive offsets and targeting the same 442 * swap type, all with matching swp pte bits. 443 * 444 * max_nr must be at least one and must be limited by the caller so scanning 445 * cannot exceed a single page table. 446 * 447 * Return: the number of table entries in the batch. 448 */ 449 static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte) 450 { 451 pte_t expected_pte = pte_next_swp_offset(pte); 452 const pte_t *end_ptep = start_ptep + max_nr; 453 const softleaf_t entry = softleaf_from_pte(pte); 454 pte_t *ptep = start_ptep + 1; 455 unsigned short cgroup_id; 456 457 VM_WARN_ON(max_nr < 1); 458 VM_WARN_ON(!softleaf_is_swap(entry)); 459 460 cgroup_id = lookup_swap_cgroup_id(entry); 461 while (ptep < end_ptep) { 462 softleaf_t entry; 463 464 pte = ptep_get(ptep); 465 466 if (!pte_same(pte, expected_pte)) 467 break; 468 entry = softleaf_from_pte(pte); 469 if (lookup_swap_cgroup_id(entry) != cgroup_id) 470 break; 471 expected_pte = pte_next_swp_offset(expected_pte); 472 ptep++; 473 } 474 475 return ptep - start_ptep; 476 } 477 #endif /* CONFIG_MMU */ 478 479 void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio, 480 int nr_throttled); 481 static inline void acct_reclaim_writeback(struct folio *folio) 482 { 483 pg_data_t *pgdat = folio_pgdat(folio); 484 int nr_throttled = atomic_read(&pgdat->nr_writeback_throttled); 485 486 if (nr_throttled) 487 __acct_reclaim_writeback(pgdat, folio, nr_throttled); 488 } 489 490 static inline void wake_throttle_isolated(pg_data_t *pgdat) 491 { 492 wait_queue_head_t *wqh; 493 494 wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED]; 495 if (waitqueue_active(wqh)) 496 wake_up(wqh); 497 } 498 499 vm_fault_t __vmf_anon_prepare(struct vm_fault *vmf); 500 static inline vm_fault_t vmf_anon_prepare(struct vm_fault *vmf) 501 { 502 vm_fault_t ret = __vmf_anon_prepare(vmf); 503 504 if (unlikely(ret & VM_FAULT_RETRY)) 505 vma_end_read(vmf->vma); 506 return ret; 507 } 508 509 vm_fault_t do_swap_page(struct vm_fault *vmf); 510 void folio_rotate_reclaimable(struct folio *folio); 511 bool __folio_end_writeback(struct folio *folio); 512 void deactivate_file_folio(struct folio *folio); 513 void folio_activate(struct folio *folio); 514 515 void free_pgtables(struct mmu_gather *tlb, struct unmap_desc *desc); 516 517 void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte); 518 519 struct zap_details; 520 void unmap_page_range(struct mmu_gather *tlb, 521 struct vm_area_struct *vma, 522 unsigned long addr, unsigned long end, 523 struct zap_details *details); 524 void zap_page_range_single_batched(struct mmu_gather *tlb, 525 struct vm_area_struct *vma, unsigned long addr, 526 unsigned long size, struct zap_details *details); 527 int folio_unmap_invalidate(struct address_space *mapping, struct folio *folio, 528 gfp_t gfp); 529 530 void page_cache_ra_order(struct readahead_control *, struct file_ra_state *); 531 void force_page_cache_ra(struct readahead_control *, unsigned long nr); 532 static inline void force_page_cache_readahead(struct address_space *mapping, 533 struct file *file, pgoff_t index, unsigned long nr_to_read) 534 { 535 DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index); 536 force_page_cache_ra(&ractl, nr_to_read); 537 } 538 539 unsigned find_lock_entries(struct address_space *mapping, pgoff_t *start, 540 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices); 541 unsigned find_get_entries(struct address_space *mapping, pgoff_t *start, 542 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices); 543 void filemap_free_folio(struct address_space *mapping, struct folio *folio); 544 int truncate_inode_folio(struct address_space *mapping, struct folio *folio); 545 bool truncate_inode_partial_folio(struct folio *folio, loff_t start, 546 loff_t end); 547 long mapping_evict_folio(struct address_space *mapping, struct folio *folio); 548 unsigned long mapping_try_invalidate(struct address_space *mapping, 549 pgoff_t start, pgoff_t end, unsigned long *nr_failed); 550 551 /** 552 * folio_evictable - Test whether a folio is evictable. 553 * @folio: The folio to test. 554 * 555 * Test whether @folio is evictable -- i.e., should be placed on 556 * active/inactive lists vs unevictable list. 557 * 558 * Reasons folio might not be evictable: 559 * 1. folio's mapping marked unevictable 560 * 2. One of the pages in the folio is part of an mlocked VMA 561 */ 562 static inline bool folio_evictable(struct folio *folio) 563 { 564 bool ret; 565 566 /* Prevent address_space of inode and swap cache from being freed */ 567 rcu_read_lock(); 568 ret = !mapping_unevictable(folio_mapping(folio)) && 569 !folio_test_mlocked(folio); 570 rcu_read_unlock(); 571 return ret; 572 } 573 574 /* 575 * Turn a non-refcounted page (->_refcount == 0) into refcounted with 576 * a count of one. 577 */ 578 static inline void set_page_refcounted(struct page *page) 579 { 580 VM_BUG_ON_PAGE(PageTail(page), page); 581 VM_BUG_ON_PAGE(page_ref_count(page), page); 582 set_page_count(page, 1); 583 } 584 585 static inline void set_pages_refcounted(struct page *page, unsigned long nr_pages) 586 { 587 unsigned long pfn = page_to_pfn(page); 588 589 for (; nr_pages--; pfn++) 590 set_page_refcounted(pfn_to_page(pfn)); 591 } 592 593 /* 594 * Return true if a folio needs ->release_folio() calling upon it. 595 */ 596 static inline bool folio_needs_release(struct folio *folio) 597 { 598 struct address_space *mapping = folio_mapping(folio); 599 600 return folio_has_private(folio) || 601 (mapping && mapping_release_always(mapping)); 602 } 603 604 extern unsigned long highest_memmap_pfn; 605 606 /* 607 * Maximum number of reclaim retries without progress before the OOM 608 * killer is consider the only way forward. 609 */ 610 #define MAX_RECLAIM_RETRIES 16 611 612 /* 613 * in mm/vmscan.c: 614 */ 615 bool folio_isolate_lru(struct folio *folio); 616 void folio_putback_lru(struct folio *folio); 617 extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason); 618 int user_proactive_reclaim(char *buf, 619 struct mem_cgroup *memcg, pg_data_t *pgdat); 620 621 /* 622 * in mm/rmap.c: 623 */ 624 pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 625 626 /* 627 * in mm/page_alloc.c 628 */ 629 #define K(x) ((x) << (PAGE_SHIFT-10)) 630 631 extern char * const zone_names[MAX_NR_ZONES]; 632 633 /* perform sanity checks on struct pages being allocated or freed */ 634 DECLARE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled); 635 636 extern int min_free_kbytes; 637 extern int defrag_mode; 638 639 void setup_per_zone_wmarks(void); 640 void calculate_min_free_kbytes(void); 641 int __meminit init_per_zone_wmark_min(void); 642 void page_alloc_sysctl_init(void); 643 644 /* 645 * Structure for holding the mostly immutable allocation parameters passed 646 * between functions involved in allocations, including the alloc_pages* 647 * family of functions. 648 * 649 * nodemask, migratetype and highest_zoneidx are initialized only once in 650 * __alloc_pages() and then never change. 651 * 652 * zonelist, preferred_zone and highest_zoneidx are set first in 653 * __alloc_pages() for the fast path, and might be later changed 654 * in __alloc_pages_slowpath(). All other functions pass the whole structure 655 * by a const pointer. 656 */ 657 struct alloc_context { 658 struct zonelist *zonelist; 659 nodemask_t *nodemask; 660 struct zoneref *preferred_zoneref; 661 int migratetype; 662 663 /* 664 * highest_zoneidx represents highest usable zone index of 665 * the allocation request. Due to the nature of the zone, 666 * memory on lower zone than the highest_zoneidx will be 667 * protected by lowmem_reserve[highest_zoneidx]. 668 * 669 * highest_zoneidx is also used by reclaim/compaction to limit 670 * the target zone since higher zone than this index cannot be 671 * usable for this allocation request. 672 */ 673 enum zone_type highest_zoneidx; 674 bool spread_dirty_pages; 675 }; 676 677 /* 678 * This function returns the order of a free page in the buddy system. In 679 * general, page_zone(page)->lock must be held by the caller to prevent the 680 * page from being allocated in parallel and returning garbage as the order. 681 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 682 * page cannot be allocated or merged in parallel. Alternatively, it must 683 * handle invalid values gracefully, and use buddy_order_unsafe() below. 684 */ 685 static inline unsigned int buddy_order(struct page *page) 686 { 687 /* PageBuddy() must be checked by the caller */ 688 return page_private(page); 689 } 690 691 /* 692 * Like buddy_order(), but for callers who cannot afford to hold the zone lock. 693 * PageBuddy() should be checked first by the caller to minimize race window, 694 * and invalid values must be handled gracefully. 695 * 696 * READ_ONCE is used so that if the caller assigns the result into a local 697 * variable and e.g. tests it for valid range before using, the compiler cannot 698 * decide to remove the variable and inline the page_private(page) multiple 699 * times, potentially observing different values in the tests and the actual 700 * use of the result. 701 */ 702 #define buddy_order_unsafe(page) READ_ONCE(page_private(page)) 703 704 /* 705 * This function checks whether a page is free && is the buddy 706 * we can coalesce a page and its buddy if 707 * (a) the buddy is not in a hole (check before calling!) && 708 * (b) the buddy is in the buddy system && 709 * (c) a page and its buddy have the same order && 710 * (d) a page and its buddy are in the same zone. 711 * 712 * For recording whether a page is in the buddy system, we set PageBuddy. 713 * Setting, clearing, and testing PageBuddy is serialized by zone->lock. 714 * 715 * For recording page's order, we use page_private(page). 716 */ 717 static inline bool page_is_buddy(struct page *page, struct page *buddy, 718 unsigned int order) 719 { 720 if (!page_is_guard(buddy) && !PageBuddy(buddy)) 721 return false; 722 723 if (buddy_order(buddy) != order) 724 return false; 725 726 /* 727 * zone check is done late to avoid uselessly calculating 728 * zone/node ids for pages that could never merge. 729 */ 730 if (page_zone_id(page) != page_zone_id(buddy)) 731 return false; 732 733 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); 734 735 return true; 736 } 737 738 /* 739 * Locate the struct page for both the matching buddy in our 740 * pair (buddy1) and the combined O(n+1) page they form (page). 741 * 742 * 1) Any buddy B1 will have an order O twin B2 which satisfies 743 * the following equation: 744 * B2 = B1 ^ (1 << O) 745 * For example, if the starting buddy (buddy2) is #8 its order 746 * 1 buddy is #10: 747 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 748 * 749 * 2) Any buddy B will have an order O+1 parent P which 750 * satisfies the following equation: 751 * P = B & ~(1 << O) 752 * 753 * Assumption: *_mem_map is contiguous at least up to MAX_PAGE_ORDER 754 */ 755 static inline unsigned long 756 __find_buddy_pfn(unsigned long page_pfn, unsigned int order) 757 { 758 return page_pfn ^ (1 << order); 759 } 760 761 /* 762 * Find the buddy of @page and validate it. 763 * @page: The input page 764 * @pfn: The pfn of the page, it saves a call to page_to_pfn() when the 765 * function is used in the performance-critical __free_one_page(). 766 * @order: The order of the page 767 * @buddy_pfn: The output pointer to the buddy pfn, it also saves a call to 768 * page_to_pfn(). 769 * 770 * The found buddy can be a non PageBuddy, out of @page's zone, or its order is 771 * not the same as @page. The validation is necessary before use it. 772 * 773 * Return: the found buddy page or NULL if not found. 774 */ 775 static inline struct page *find_buddy_page_pfn(struct page *page, 776 unsigned long pfn, unsigned int order, unsigned long *buddy_pfn) 777 { 778 unsigned long __buddy_pfn = __find_buddy_pfn(pfn, order); 779 struct page *buddy; 780 781 buddy = page + (__buddy_pfn - pfn); 782 if (buddy_pfn) 783 *buddy_pfn = __buddy_pfn; 784 785 if (page_is_buddy(page, buddy, order)) 786 return buddy; 787 return NULL; 788 } 789 790 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn, 791 unsigned long end_pfn, struct zone *zone); 792 793 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn, 794 unsigned long end_pfn, struct zone *zone) 795 { 796 if (zone->contiguous) 797 return pfn_to_page(start_pfn); 798 799 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone); 800 } 801 802 void set_zone_contiguous(struct zone *zone); 803 bool pfn_range_intersects_zones(int nid, unsigned long start_pfn, 804 unsigned long nr_pages); 805 806 static inline void clear_zone_contiguous(struct zone *zone) 807 { 808 zone->contiguous = false; 809 } 810 811 extern int __isolate_free_page(struct page *page, unsigned int order); 812 extern void __putback_isolated_page(struct page *page, unsigned int order, 813 int mt); 814 extern void memblock_free_pages(struct page *page, unsigned long pfn, 815 unsigned int order); 816 extern void __free_pages_core(struct page *page, unsigned int order, 817 enum meminit_context context); 818 819 /* 820 * This will have no effect, other than possibly generating a warning, if the 821 * caller passes in a non-large folio. 822 */ 823 static inline void folio_set_order(struct folio *folio, unsigned int order) 824 { 825 if (WARN_ON_ONCE(!order || !folio_test_large(folio))) 826 return; 827 VM_WARN_ON_ONCE(order > MAX_FOLIO_ORDER); 828 829 folio->_flags_1 = (folio->_flags_1 & ~0xffUL) | order; 830 #ifdef NR_PAGES_IN_LARGE_FOLIO 831 folio->_nr_pages = 1U << order; 832 #endif 833 } 834 835 bool __folio_unqueue_deferred_split(struct folio *folio); 836 static inline bool folio_unqueue_deferred_split(struct folio *folio) 837 { 838 if (folio_order(folio) <= 1 || !folio_test_large_rmappable(folio)) 839 return false; 840 841 /* 842 * At this point, there is no one trying to add the folio to 843 * deferred_list. If folio is not in deferred_list, it's safe 844 * to check without acquiring the split_queue_lock. 845 */ 846 if (data_race(list_empty(&folio->_deferred_list))) 847 return false; 848 849 return __folio_unqueue_deferred_split(folio); 850 } 851 852 static inline struct folio *page_rmappable_folio(struct page *page) 853 { 854 struct folio *folio = (struct folio *)page; 855 856 if (folio && folio_test_large(folio)) 857 folio_set_large_rmappable(folio); 858 return folio; 859 } 860 861 static inline void prep_compound_head(struct page *page, unsigned int order) 862 { 863 struct folio *folio = (struct folio *)page; 864 865 folio_set_order(folio, order); 866 atomic_set(&folio->_large_mapcount, -1); 867 if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) 868 atomic_set(&folio->_nr_pages_mapped, 0); 869 if (IS_ENABLED(CONFIG_MM_ID)) { 870 folio->_mm_ids = 0; 871 folio->_mm_id_mapcount[0] = -1; 872 folio->_mm_id_mapcount[1] = -1; 873 } 874 if (IS_ENABLED(CONFIG_64BIT) || order > 1) { 875 atomic_set(&folio->_pincount, 0); 876 atomic_set(&folio->_entire_mapcount, -1); 877 } 878 if (order > 1) 879 INIT_LIST_HEAD(&folio->_deferred_list); 880 } 881 882 static inline void prep_compound_tail(struct page *head, int tail_idx) 883 { 884 struct page *p = head + tail_idx; 885 886 p->mapping = TAIL_MAPPING; 887 set_compound_head(p, head); 888 set_page_private(p, 0); 889 } 890 891 void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags); 892 extern bool free_pages_prepare(struct page *page, unsigned int order); 893 894 extern int user_min_free_kbytes; 895 896 struct page *__alloc_frozen_pages_noprof(gfp_t, unsigned int order, int nid, 897 nodemask_t *); 898 #define __alloc_frozen_pages(...) \ 899 alloc_hooks(__alloc_frozen_pages_noprof(__VA_ARGS__)) 900 void free_frozen_pages(struct page *page, unsigned int order); 901 void free_unref_folios(struct folio_batch *fbatch); 902 903 #ifdef CONFIG_NUMA 904 struct page *alloc_frozen_pages_noprof(gfp_t, unsigned int order); 905 #else 906 static inline struct page *alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order) 907 { 908 return __alloc_frozen_pages_noprof(gfp, order, numa_node_id(), NULL); 909 } 910 #endif 911 912 #define alloc_frozen_pages(...) \ 913 alloc_hooks(alloc_frozen_pages_noprof(__VA_ARGS__)) 914 915 struct page *alloc_frozen_pages_nolock_noprof(gfp_t gfp_flags, int nid, unsigned int order); 916 #define alloc_frozen_pages_nolock(...) \ 917 alloc_hooks(alloc_frozen_pages_nolock_noprof(__VA_ARGS__)) 918 919 extern void zone_pcp_reset(struct zone *zone); 920 extern void zone_pcp_disable(struct zone *zone); 921 extern void zone_pcp_enable(struct zone *zone); 922 extern void zone_pcp_init(struct zone *zone); 923 924 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align, 925 phys_addr_t min_addr, 926 int nid, bool exact_nid); 927 928 void memmap_init_range(unsigned long, int, unsigned long, unsigned long, 929 unsigned long, enum meminit_context, struct vmem_altmap *, int, 930 bool); 931 932 #ifdef CONFIG_SPARSEMEM 933 void sparse_init(void); 934 #else 935 static inline void sparse_init(void) {} 936 #endif /* CONFIG_SPARSEMEM */ 937 938 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 939 940 /* 941 * in mm/compaction.c 942 */ 943 /* 944 * compact_control is used to track pages being migrated and the free pages 945 * they are being migrated to during memory compaction. The free_pfn starts 946 * at the end of a zone and migrate_pfn begins at the start. Movable pages 947 * are moved to the end of a zone during a compaction run and the run 948 * completes when free_pfn <= migrate_pfn 949 */ 950 struct compact_control { 951 struct list_head freepages[NR_PAGE_ORDERS]; /* List of free pages to migrate to */ 952 struct list_head migratepages; /* List of pages being migrated */ 953 unsigned int nr_freepages; /* Number of isolated free pages */ 954 unsigned int nr_migratepages; /* Number of pages to migrate */ 955 unsigned long free_pfn; /* isolate_freepages search base */ 956 /* 957 * Acts as an in/out parameter to page isolation for migration. 958 * isolate_migratepages uses it as a search base. 959 * isolate_migratepages_block will update the value to the next pfn 960 * after the last isolated one. 961 */ 962 unsigned long migrate_pfn; 963 unsigned long fast_start_pfn; /* a pfn to start linear scan from */ 964 struct zone *zone; 965 unsigned long total_migrate_scanned; 966 unsigned long total_free_scanned; 967 unsigned short fast_search_fail;/* failures to use free list searches */ 968 short search_order; /* order to start a fast search at */ 969 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 970 int order; /* order a direct compactor needs */ 971 int migratetype; /* migratetype of direct compactor */ 972 const unsigned int alloc_flags; /* alloc flags of a direct compactor */ 973 const int highest_zoneidx; /* zone index of a direct compactor */ 974 enum migrate_mode mode; /* Async or sync migration mode */ 975 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 976 bool no_set_skip_hint; /* Don't mark blocks for skipping */ 977 bool ignore_block_suitable; /* Scan blocks considered unsuitable */ 978 bool direct_compaction; /* False from kcompactd or /proc/... */ 979 bool proactive_compaction; /* kcompactd proactive compaction */ 980 bool whole_zone; /* Whole zone should/has been scanned */ 981 bool contended; /* Signal lock contention */ 982 bool finish_pageblock; /* Scan the remainder of a pageblock. Used 983 * when there are potentially transient 984 * isolation or migration failures to 985 * ensure forward progress. 986 */ 987 bool alloc_contig; /* alloc_contig_range allocation */ 988 }; 989 990 /* 991 * Used in direct compaction when a page should be taken from the freelists 992 * immediately when one is created during the free path. 993 */ 994 struct capture_control { 995 struct compact_control *cc; 996 struct page *page; 997 }; 998 999 unsigned long 1000 isolate_freepages_range(struct compact_control *cc, 1001 unsigned long start_pfn, unsigned long end_pfn); 1002 int 1003 isolate_migratepages_range(struct compact_control *cc, 1004 unsigned long low_pfn, unsigned long end_pfn); 1005 1006 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */ 1007 void init_cma_reserved_pageblock(struct page *page); 1008 1009 #endif /* CONFIG_COMPACTION || CONFIG_CMA */ 1010 1011 struct cma; 1012 1013 #ifdef CONFIG_CMA 1014 bool cma_validate_zones(struct cma *cma); 1015 void *cma_reserve_early(struct cma *cma, unsigned long size); 1016 void init_cma_pageblock(struct page *page); 1017 #else 1018 static inline bool cma_validate_zones(struct cma *cma) 1019 { 1020 return false; 1021 } 1022 static inline void *cma_reserve_early(struct cma *cma, unsigned long size) 1023 { 1024 return NULL; 1025 } 1026 static inline void init_cma_pageblock(struct page *page) 1027 { 1028 } 1029 #endif 1030 1031 1032 int find_suitable_fallback(struct free_area *area, unsigned int order, 1033 int migratetype, bool claimable); 1034 1035 static inline bool free_area_empty(struct free_area *area, int migratetype) 1036 { 1037 return list_empty(&area->free_list[migratetype]); 1038 } 1039 1040 /* mm/util.c */ 1041 struct anon_vma *folio_anon_vma(const struct folio *folio); 1042 1043 #ifdef CONFIG_MMU 1044 void unmap_mapping_folio(struct folio *folio); 1045 extern long populate_vma_page_range(struct vm_area_struct *vma, 1046 unsigned long start, unsigned long end, int *locked); 1047 extern long faultin_page_range(struct mm_struct *mm, unsigned long start, 1048 unsigned long end, bool write, int *locked); 1049 bool mlock_future_ok(const struct mm_struct *mm, bool is_vma_locked, 1050 unsigned long bytes); 1051 1052 /* 1053 * NOTE: This function can't tell whether the folio is "fully mapped" in the 1054 * range. 1055 * "fully mapped" means all the pages of folio is associated with the page 1056 * table of range while this function just check whether the folio range is 1057 * within the range [start, end). Function caller needs to do page table 1058 * check if it cares about the page table association. 1059 * 1060 * Typical usage (like mlock or madvise) is: 1061 * Caller knows at least 1 page of folio is associated with page table of VMA 1062 * and the range [start, end) is intersect with the VMA range. Caller wants 1063 * to know whether the folio is fully associated with the range. It calls 1064 * this function to check whether the folio is in the range first. Then checks 1065 * the page table to know whether the folio is fully mapped to the range. 1066 */ 1067 static inline bool 1068 folio_within_range(struct folio *folio, struct vm_area_struct *vma, 1069 unsigned long start, unsigned long end) 1070 { 1071 pgoff_t pgoff, addr; 1072 unsigned long vma_pglen = vma_pages(vma); 1073 1074 VM_WARN_ON_FOLIO(folio_test_ksm(folio), folio); 1075 if (start > end) 1076 return false; 1077 1078 if (start < vma->vm_start) 1079 start = vma->vm_start; 1080 1081 if (end > vma->vm_end) 1082 end = vma->vm_end; 1083 1084 pgoff = folio_pgoff(folio); 1085 1086 /* if folio start address is not in vma range */ 1087 if (!in_range(pgoff, vma->vm_pgoff, vma_pglen)) 1088 return false; 1089 1090 addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 1091 1092 return !(addr < start || end - addr < folio_size(folio)); 1093 } 1094 1095 static inline bool 1096 folio_within_vma(struct folio *folio, struct vm_area_struct *vma) 1097 { 1098 return folio_within_range(folio, vma, vma->vm_start, vma->vm_end); 1099 } 1100 1101 /* 1102 * mlock_vma_folio() and munlock_vma_folio(): 1103 * should be called with vma's mmap_lock held for read or write, 1104 * under page table lock for the pte/pmd being added or removed. 1105 * 1106 * mlock is usually called at the end of folio_add_*_rmap_*(), munlock at 1107 * the end of folio_remove_rmap_*(); but new anon folios are managed by 1108 * folio_add_lru_vma() calling mlock_new_folio(). 1109 */ 1110 void mlock_folio(struct folio *folio); 1111 static inline void mlock_vma_folio(struct folio *folio, 1112 struct vm_area_struct *vma) 1113 { 1114 /* 1115 * The VM_SPECIAL check here serves two purposes. 1116 * 1) VM_IO check prevents migration from double-counting during mlock. 1117 * 2) Although mmap_region() and mlock_fixup() take care that VM_LOCKED 1118 * is never left set on a VM_SPECIAL vma, there is an interval while 1119 * file->f_op->mmap() is using vm_insert_page(s), when VM_LOCKED may 1120 * still be set while VM_SPECIAL bits are added: so ignore it then. 1121 */ 1122 if (unlikely((vma->vm_flags & (VM_LOCKED|VM_SPECIAL)) == VM_LOCKED)) 1123 mlock_folio(folio); 1124 } 1125 1126 void munlock_folio(struct folio *folio); 1127 static inline void munlock_vma_folio(struct folio *folio, 1128 struct vm_area_struct *vma) 1129 { 1130 /* 1131 * munlock if the function is called. Ideally, we should only 1132 * do munlock if any page of folio is unmapped from VMA and 1133 * cause folio not fully mapped to VMA. 1134 * 1135 * But it's not easy to confirm that's the situation. So we 1136 * always munlock the folio and page reclaim will correct it 1137 * if it's wrong. 1138 */ 1139 if (unlikely(vma->vm_flags & VM_LOCKED)) 1140 munlock_folio(folio); 1141 } 1142 1143 void mlock_new_folio(struct folio *folio); 1144 bool need_mlock_drain(int cpu); 1145 void mlock_drain_local(void); 1146 void mlock_drain_remote(int cpu); 1147 1148 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 1149 1150 /** 1151 * vma_address - Find the virtual address a page range is mapped at 1152 * @vma: The vma which maps this object. 1153 * @pgoff: The page offset within its object. 1154 * @nr_pages: The number of pages to consider. 1155 * 1156 * If any page in this range is mapped by this VMA, return the first address 1157 * where any of these pages appear. Otherwise, return -EFAULT. 1158 */ 1159 static inline unsigned long vma_address(const struct vm_area_struct *vma, 1160 pgoff_t pgoff, unsigned long nr_pages) 1161 { 1162 unsigned long address; 1163 1164 if (pgoff >= vma->vm_pgoff) { 1165 address = vma->vm_start + 1166 ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 1167 /* Check for address beyond vma (or wrapped through 0?) */ 1168 if (address < vma->vm_start || address >= vma->vm_end) 1169 address = -EFAULT; 1170 } else if (pgoff + nr_pages - 1 >= vma->vm_pgoff) { 1171 /* Test above avoids possibility of wrap to 0 on 32-bit */ 1172 address = vma->vm_start; 1173 } else { 1174 address = -EFAULT; 1175 } 1176 return address; 1177 } 1178 1179 /* 1180 * Then at what user virtual address will none of the range be found in vma? 1181 * Assumes that vma_address() already returned a good starting address. 1182 */ 1183 static inline unsigned long vma_address_end(struct page_vma_mapped_walk *pvmw) 1184 { 1185 struct vm_area_struct *vma = pvmw->vma; 1186 pgoff_t pgoff; 1187 unsigned long address; 1188 1189 /* Common case, plus ->pgoff is invalid for KSM */ 1190 if (pvmw->nr_pages == 1) 1191 return pvmw->address + PAGE_SIZE; 1192 1193 pgoff = pvmw->pgoff + pvmw->nr_pages; 1194 address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 1195 /* Check for address beyond vma (or wrapped through 0?) */ 1196 if (address < vma->vm_start || address > vma->vm_end) 1197 address = vma->vm_end; 1198 return address; 1199 } 1200 1201 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, 1202 struct file *fpin) 1203 { 1204 int flags = vmf->flags; 1205 1206 if (fpin) 1207 return fpin; 1208 1209 /* 1210 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or 1211 * anything, so we only pin the file and drop the mmap_lock if only 1212 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt. 1213 */ 1214 if (fault_flag_allow_retry_first(flags) && 1215 !(flags & FAULT_FLAG_RETRY_NOWAIT)) { 1216 fpin = get_file(vmf->vma->vm_file); 1217 release_fault_lock(vmf); 1218 } 1219 return fpin; 1220 } 1221 #else /* !CONFIG_MMU */ 1222 static inline void unmap_mapping_folio(struct folio *folio) { } 1223 static inline void mlock_new_folio(struct folio *folio) { } 1224 static inline bool need_mlock_drain(int cpu) { return false; } 1225 static inline void mlock_drain_local(void) { } 1226 static inline void mlock_drain_remote(int cpu) { } 1227 static inline void vunmap_range_noflush(unsigned long start, unsigned long end) 1228 { 1229 } 1230 #endif /* !CONFIG_MMU */ 1231 1232 /* Memory initialisation debug and verification */ 1233 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 1234 DECLARE_STATIC_KEY_TRUE(deferred_pages); 1235 1236 bool __init deferred_grow_zone(struct zone *zone, unsigned int order); 1237 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 1238 1239 void init_deferred_page(unsigned long pfn, int nid); 1240 1241 enum mminit_level { 1242 MMINIT_WARNING, 1243 MMINIT_VERIFY, 1244 MMINIT_TRACE 1245 }; 1246 1247 #ifdef CONFIG_DEBUG_MEMORY_INIT 1248 1249 extern int mminit_loglevel; 1250 1251 #define mminit_dprintk(level, prefix, fmt, arg...) \ 1252 do { \ 1253 if (level < mminit_loglevel) { \ 1254 if (level <= MMINIT_WARNING) \ 1255 pr_warn("mminit::" prefix " " fmt, ##arg); \ 1256 else \ 1257 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 1258 } \ 1259 } while (0) 1260 1261 extern void mminit_verify_pageflags_layout(void); 1262 extern void mminit_verify_zonelist(void); 1263 #else 1264 1265 static inline void mminit_dprintk(enum mminit_level level, 1266 const char *prefix, const char *fmt, ...) 1267 { 1268 } 1269 1270 static inline void mminit_verify_pageflags_layout(void) 1271 { 1272 } 1273 1274 static inline void mminit_verify_zonelist(void) 1275 { 1276 } 1277 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 1278 1279 #define NODE_RECLAIM_NOSCAN -2 1280 #define NODE_RECLAIM_FULL -1 1281 #define NODE_RECLAIM_SOME 0 1282 #define NODE_RECLAIM_SUCCESS 1 1283 1284 #ifdef CONFIG_NUMA 1285 extern int node_reclaim_mode; 1286 1287 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); 1288 extern int find_next_best_node(int node, nodemask_t *used_node_mask); 1289 #else 1290 #define node_reclaim_mode 0 1291 1292 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, 1293 unsigned int order) 1294 { 1295 return NODE_RECLAIM_NOSCAN; 1296 } 1297 static inline int find_next_best_node(int node, nodemask_t *used_node_mask) 1298 { 1299 return NUMA_NO_NODE; 1300 } 1301 #endif 1302 1303 static inline bool node_reclaim_enabled(void) 1304 { 1305 /* Is any node_reclaim_mode bit set? */ 1306 return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP); 1307 } 1308 1309 /* 1310 * mm/memory-failure.c 1311 */ 1312 #ifdef CONFIG_MEMORY_FAILURE 1313 int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill); 1314 void shake_folio(struct folio *folio); 1315 typedef int hwpoison_filter_func_t(struct page *p); 1316 void hwpoison_filter_register(hwpoison_filter_func_t *filter); 1317 void hwpoison_filter_unregister(void); 1318 1319 #define MAGIC_HWPOISON 0x48575053U /* HWPS */ 1320 void SetPageHWPoisonTakenOff(struct page *page); 1321 void ClearPageHWPoisonTakenOff(struct page *page); 1322 bool take_page_off_buddy(struct page *page); 1323 bool put_page_back_buddy(struct page *page); 1324 struct task_struct *task_early_kill(struct task_struct *tsk, int force_early); 1325 void add_to_kill_ksm(struct task_struct *tsk, const struct page *p, 1326 struct vm_area_struct *vma, struct list_head *to_kill, 1327 unsigned long ksm_addr); 1328 unsigned long page_mapped_in_vma(const struct page *page, 1329 struct vm_area_struct *vma); 1330 1331 #else 1332 static inline int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill) 1333 { 1334 return -EBUSY; 1335 } 1336 #endif 1337 1338 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 1339 unsigned long, unsigned long, 1340 unsigned long, unsigned long); 1341 1342 extern void set_pageblock_order(void); 1343 unsigned long reclaim_pages(struct list_head *folio_list); 1344 unsigned int reclaim_clean_pages_from_list(struct zone *zone, 1345 struct list_head *folio_list); 1346 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 1347 #define ALLOC_WMARK_MIN WMARK_MIN 1348 #define ALLOC_WMARK_LOW WMARK_LOW 1349 #define ALLOC_WMARK_HIGH WMARK_HIGH 1350 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 1351 1352 /* Mask to get the watermark bits */ 1353 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 1354 1355 /* 1356 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we 1357 * cannot assume a reduced access to memory reserves is sufficient for 1358 * !MMU 1359 */ 1360 #ifdef CONFIG_MMU 1361 #define ALLOC_OOM 0x08 1362 #else 1363 #define ALLOC_OOM ALLOC_NO_WATERMARKS 1364 #endif 1365 1366 #define ALLOC_NON_BLOCK 0x10 /* Caller cannot block. Allow access 1367 * to 25% of the min watermark or 1368 * 62.5% if __GFP_HIGH is set. 1369 */ 1370 #define ALLOC_MIN_RESERVE 0x20 /* __GFP_HIGH set. Allow access to 50% 1371 * of the min watermark. 1372 */ 1373 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1374 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 1375 #ifdef CONFIG_ZONE_DMA32 1376 #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */ 1377 #else 1378 #define ALLOC_NOFRAGMENT 0x0 1379 #endif 1380 #define ALLOC_HIGHATOMIC 0x200 /* Allows access to MIGRATE_HIGHATOMIC */ 1381 #define ALLOC_TRYLOCK 0x400 /* Only use spin_trylock in allocation path */ 1382 #define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */ 1383 1384 /* Flags that allow allocations below the min watermark. */ 1385 #define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM) 1386 1387 enum ttu_flags; 1388 struct tlbflush_unmap_batch; 1389 1390 1391 /* 1392 * only for MM internal work items which do not depend on 1393 * any allocations or locks which might depend on allocations 1394 */ 1395 extern struct workqueue_struct *mm_percpu_wq; 1396 1397 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 1398 void try_to_unmap_flush(void); 1399 void try_to_unmap_flush_dirty(void); 1400 void flush_tlb_batched_pending(struct mm_struct *mm); 1401 #else 1402 static inline void try_to_unmap_flush(void) 1403 { 1404 } 1405 static inline void try_to_unmap_flush_dirty(void) 1406 { 1407 } 1408 static inline void flush_tlb_batched_pending(struct mm_struct *mm) 1409 { 1410 } 1411 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 1412 1413 extern const struct trace_print_flags pageflag_names[]; 1414 extern const struct trace_print_flags vmaflag_names[]; 1415 extern const struct trace_print_flags gfpflag_names[]; 1416 1417 void setup_zone_pageset(struct zone *zone); 1418 1419 struct migration_target_control { 1420 int nid; /* preferred node id */ 1421 nodemask_t *nmask; 1422 gfp_t gfp_mask; 1423 enum migrate_reason reason; 1424 }; 1425 1426 /* 1427 * mm/filemap.c 1428 */ 1429 size_t splice_folio_into_pipe(struct pipe_inode_info *pipe, 1430 struct folio *folio, loff_t fpos, size_t size); 1431 1432 /* 1433 * mm/vmalloc.c 1434 */ 1435 #ifdef CONFIG_MMU 1436 void __init vmalloc_init(void); 1437 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end, 1438 pgprot_t prot, struct page **pages, unsigned int page_shift, gfp_t gfp_mask); 1439 unsigned int get_vm_area_page_order(struct vm_struct *vm); 1440 #else 1441 static inline void vmalloc_init(void) 1442 { 1443 } 1444 1445 static inline 1446 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end, 1447 pgprot_t prot, struct page **pages, unsigned int page_shift, gfp_t gfp_mask) 1448 { 1449 return -EINVAL; 1450 } 1451 #endif 1452 1453 int __must_check __vmap_pages_range_noflush(unsigned long addr, 1454 unsigned long end, pgprot_t prot, 1455 struct page **pages, unsigned int page_shift); 1456 1457 void vunmap_range_noflush(unsigned long start, unsigned long end); 1458 1459 void __vunmap_range_noflush(unsigned long start, unsigned long end); 1460 1461 static inline bool vma_is_single_threaded_private(struct vm_area_struct *vma) 1462 { 1463 if (vma->vm_flags & VM_SHARED) 1464 return false; 1465 1466 return atomic_read(&vma->vm_mm->mm_users) == 1; 1467 } 1468 1469 #ifdef CONFIG_NUMA_BALANCING 1470 bool folio_can_map_prot_numa(struct folio *folio, struct vm_area_struct *vma, 1471 bool is_private_single_threaded); 1472 1473 #else 1474 static inline bool folio_can_map_prot_numa(struct folio *folio, 1475 struct vm_area_struct *vma, bool is_private_single_threaded) 1476 { 1477 return false; 1478 } 1479 #endif 1480 1481 int numa_migrate_check(struct folio *folio, struct vm_fault *vmf, 1482 unsigned long addr, int *flags, bool writable, 1483 int *last_cpupid); 1484 1485 void free_zone_device_folio(struct folio *folio); 1486 int migrate_device_coherent_folio(struct folio *folio); 1487 1488 struct vm_struct *__get_vm_area_node(unsigned long size, 1489 unsigned long align, unsigned long shift, 1490 unsigned long vm_flags, unsigned long start, 1491 unsigned long end, int node, gfp_t gfp_mask, 1492 const void *caller); 1493 1494 /* 1495 * mm/gup.c 1496 */ 1497 int __must_check try_grab_folio(struct folio *folio, int refs, 1498 unsigned int flags); 1499 1500 /* 1501 * mm/huge_memory.c 1502 */ 1503 void touch_pud(struct vm_area_struct *vma, unsigned long addr, 1504 pud_t *pud, bool write); 1505 bool touch_pmd(struct vm_area_struct *vma, unsigned long addr, 1506 pmd_t *pmd, bool write); 1507 1508 /* 1509 * Parses a string with mem suffixes into its order. Useful to parse kernel 1510 * parameters. 1511 */ 1512 static inline int get_order_from_str(const char *size_str, 1513 unsigned long valid_orders) 1514 { 1515 unsigned long size; 1516 char *endptr; 1517 int order; 1518 1519 size = memparse(size_str, &endptr); 1520 1521 if (!is_power_of_2(size)) 1522 return -EINVAL; 1523 order = get_order(size); 1524 if (BIT(order) & ~valid_orders) 1525 return -EINVAL; 1526 1527 return order; 1528 } 1529 1530 enum { 1531 /* mark page accessed */ 1532 FOLL_TOUCH = 1 << 16, 1533 /* a retry, previous pass started an IO */ 1534 FOLL_TRIED = 1 << 17, 1535 /* we are working on non-current tsk/mm */ 1536 FOLL_REMOTE = 1 << 18, 1537 /* pages must be released via unpin_user_page */ 1538 FOLL_PIN = 1 << 19, 1539 /* gup_fast: prevent fall-back to slow gup */ 1540 FOLL_FAST_ONLY = 1 << 20, 1541 /* allow unlocking the mmap lock */ 1542 FOLL_UNLOCKABLE = 1 << 21, 1543 /* VMA lookup+checks compatible with MADV_POPULATE_(READ|WRITE) */ 1544 FOLL_MADV_POPULATE = 1 << 22, 1545 }; 1546 1547 #define INTERNAL_GUP_FLAGS (FOLL_TOUCH | FOLL_TRIED | FOLL_REMOTE | FOLL_PIN | \ 1548 FOLL_FAST_ONLY | FOLL_UNLOCKABLE | \ 1549 FOLL_MADV_POPULATE) 1550 1551 /* 1552 * Indicates for which pages that are write-protected in the page table, 1553 * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that the 1554 * GUP pin will remain consistent with the pages mapped into the page tables 1555 * of the MM. 1556 * 1557 * Temporary unmapping of PageAnonExclusive() pages or clearing of 1558 * PageAnonExclusive() has to protect against concurrent GUP: 1559 * * Ordinary GUP: Using the PT lock 1560 * * GUP-fast and fork(): mm->write_protect_seq 1561 * * GUP-fast and KSM or temporary unmapping (swap, migration): see 1562 * folio_try_share_anon_rmap_*() 1563 * 1564 * Must be called with the (sub)page that's actually referenced via the 1565 * page table entry, which might not necessarily be the head page for a 1566 * PTE-mapped THP. 1567 * 1568 * If the vma is NULL, we're coming from the GUP-fast path and might have 1569 * to fallback to the slow path just to lookup the vma. 1570 */ 1571 static inline bool gup_must_unshare(struct vm_area_struct *vma, 1572 unsigned int flags, struct page *page) 1573 { 1574 /* 1575 * FOLL_WRITE is implicitly handled correctly as the page table entry 1576 * has to be writable -- and if it references (part of) an anonymous 1577 * folio, that part is required to be marked exclusive. 1578 */ 1579 if ((flags & (FOLL_WRITE | FOLL_PIN)) != FOLL_PIN) 1580 return false; 1581 /* 1582 * Note: PageAnon(page) is stable until the page is actually getting 1583 * freed. 1584 */ 1585 if (!PageAnon(page)) { 1586 /* 1587 * We only care about R/O long-term pining: R/O short-term 1588 * pinning does not have the semantics to observe successive 1589 * changes through the process page tables. 1590 */ 1591 if (!(flags & FOLL_LONGTERM)) 1592 return false; 1593 1594 /* We really need the vma ... */ 1595 if (!vma) 1596 return true; 1597 1598 /* 1599 * ... because we only care about writable private ("COW") 1600 * mappings where we have to break COW early. 1601 */ 1602 return is_cow_mapping(vma->vm_flags); 1603 } 1604 1605 /* Paired with a memory barrier in folio_try_share_anon_rmap_*(). */ 1606 if (IS_ENABLED(CONFIG_HAVE_GUP_FAST)) 1607 smp_rmb(); 1608 1609 /* 1610 * Note that KSM pages cannot be exclusive, and consequently, 1611 * cannot get pinned. 1612 */ 1613 return !PageAnonExclusive(page); 1614 } 1615 1616 extern bool mirrored_kernelcore; 1617 bool memblock_has_mirror(void); 1618 void memblock_free_all(void); 1619 1620 static __always_inline void vma_set_range(struct vm_area_struct *vma, 1621 unsigned long start, unsigned long end, 1622 pgoff_t pgoff) 1623 { 1624 vma->vm_start = start; 1625 vma->vm_end = end; 1626 vma->vm_pgoff = pgoff; 1627 } 1628 1629 static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma) 1630 { 1631 /* 1632 * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty 1633 * enablements, because when without soft-dirty being compiled in, 1634 * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY) 1635 * will be constantly true. 1636 */ 1637 if (!pgtable_supports_soft_dirty()) 1638 return false; 1639 1640 /* 1641 * Soft-dirty is kind of special: its tracking is enabled when the 1642 * vma flags not set. 1643 */ 1644 return !(vma->vm_flags & VM_SOFTDIRTY); 1645 } 1646 1647 static inline bool pmd_needs_soft_dirty_wp(struct vm_area_struct *vma, pmd_t pmd) 1648 { 1649 return vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd); 1650 } 1651 1652 static inline bool pte_needs_soft_dirty_wp(struct vm_area_struct *vma, pte_t pte) 1653 { 1654 return vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte); 1655 } 1656 1657 void __meminit __init_single_page(struct page *page, unsigned long pfn, 1658 unsigned long zone, int nid); 1659 void __meminit __init_page_from_nid(unsigned long pfn, int nid); 1660 1661 /* shrinker related functions */ 1662 unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg, 1663 int priority); 1664 1665 int shmem_add_to_page_cache(struct folio *folio, 1666 struct address_space *mapping, 1667 pgoff_t index, void *expected, gfp_t gfp); 1668 int shmem_inode_acct_blocks(struct inode *inode, long pages); 1669 bool shmem_recalc_inode(struct inode *inode, long alloced, long swapped); 1670 1671 #ifdef CONFIG_SHRINKER_DEBUG 1672 static inline __printf(2, 0) int shrinker_debugfs_name_alloc( 1673 struct shrinker *shrinker, const char *fmt, va_list ap) 1674 { 1675 shrinker->name = kvasprintf_const(GFP_KERNEL, fmt, ap); 1676 1677 return shrinker->name ? 0 : -ENOMEM; 1678 } 1679 1680 static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) 1681 { 1682 kfree_const(shrinker->name); 1683 shrinker->name = NULL; 1684 } 1685 1686 extern int shrinker_debugfs_add(struct shrinker *shrinker); 1687 extern struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, 1688 int *debugfs_id); 1689 extern void shrinker_debugfs_remove(struct dentry *debugfs_entry, 1690 int debugfs_id); 1691 #else /* CONFIG_SHRINKER_DEBUG */ 1692 static inline int shrinker_debugfs_add(struct shrinker *shrinker) 1693 { 1694 return 0; 1695 } 1696 static inline int shrinker_debugfs_name_alloc(struct shrinker *shrinker, 1697 const char *fmt, va_list ap) 1698 { 1699 return 0; 1700 } 1701 static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) 1702 { 1703 } 1704 static inline struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, 1705 int *debugfs_id) 1706 { 1707 *debugfs_id = -1; 1708 return NULL; 1709 } 1710 static inline void shrinker_debugfs_remove(struct dentry *debugfs_entry, 1711 int debugfs_id) 1712 { 1713 } 1714 #endif /* CONFIG_SHRINKER_DEBUG */ 1715 1716 /* Only track the nodes of mappings with shadow entries */ 1717 void workingset_update_node(struct xa_node *node); 1718 extern struct list_lru shadow_nodes; 1719 #define mapping_set_update(xas, mapping) do { \ 1720 if (!dax_mapping(mapping) && !shmem_mapping(mapping)) { \ 1721 xas_set_update(xas, workingset_update_node); \ 1722 xas_set_lru(xas, &shadow_nodes); \ 1723 } \ 1724 } while (0) 1725 1726 /* mremap.c */ 1727 unsigned long move_page_tables(struct pagetable_move_control *pmc); 1728 1729 #ifdef CONFIG_UNACCEPTED_MEMORY 1730 void accept_page(struct page *page); 1731 #else /* CONFIG_UNACCEPTED_MEMORY */ 1732 static inline void accept_page(struct page *page) 1733 { 1734 } 1735 #endif /* CONFIG_UNACCEPTED_MEMORY */ 1736 1737 /* pagewalk.c */ 1738 int walk_page_range_mm_unsafe(struct mm_struct *mm, unsigned long start, 1739 unsigned long end, const struct mm_walk_ops *ops, 1740 void *private); 1741 int walk_page_range_vma_unsafe(struct vm_area_struct *vma, unsigned long start, 1742 unsigned long end, const struct mm_walk_ops *ops, 1743 void *private); 1744 int walk_page_range_debug(struct mm_struct *mm, unsigned long start, 1745 unsigned long end, const struct mm_walk_ops *ops, 1746 pgd_t *pgd, void *private); 1747 1748 void dup_mm_exe_file(struct mm_struct *mm, struct mm_struct *oldmm); 1749 int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm); 1750 1751 void remap_pfn_range_prepare(struct vm_area_desc *desc, unsigned long pfn); 1752 int remap_pfn_range_complete(struct vm_area_struct *vma, unsigned long addr, 1753 unsigned long pfn, unsigned long size, pgprot_t pgprot); 1754 1755 static inline void io_remap_pfn_range_prepare(struct vm_area_desc *desc, 1756 unsigned long orig_pfn, unsigned long size) 1757 { 1758 const unsigned long pfn = io_remap_pfn_range_pfn(orig_pfn, size); 1759 1760 return remap_pfn_range_prepare(desc, pfn); 1761 } 1762 1763 static inline int io_remap_pfn_range_complete(struct vm_area_struct *vma, 1764 unsigned long addr, unsigned long orig_pfn, unsigned long size, 1765 pgprot_t orig_prot) 1766 { 1767 const unsigned long pfn = io_remap_pfn_range_pfn(orig_pfn, size); 1768 const pgprot_t prot = pgprot_decrypted(orig_prot); 1769 1770 return remap_pfn_range_complete(vma, addr, pfn, size, prot); 1771 } 1772 1773 #endif /* __MM_INTERNAL_H */ 1774