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