1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* internal.h: mm/ internal definitions 3 * 4 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 #ifndef __MM_INTERNAL_H 8 #define __MM_INTERNAL_H 9 10 #include <linux/fs.h> 11 #include <linux/khugepaged.h> 12 #include <linux/mm.h> 13 #include <linux/mm_inline.h> 14 #include <linux/pagemap.h> 15 #include <linux/pagewalk.h> 16 #include <linux/rmap.h> 17 #include <linux/swap.h> 18 #include <linux/swapops.h> 19 #include <linux/swap_cgroup.h> 20 #include <linux/tracepoint-defs.h> 21 22 /* Internal core VMA manipulation functions. */ 23 #include "vma.h" 24 25 struct folio_batch; 26 27 /* 28 * Maintains state across a page table move. The operation assumes both source 29 * and destination VMAs already exist and are specified by the user. 30 * 31 * Partial moves are permitted, but the old and new ranges must both reside 32 * within a VMA. 33 * 34 * mmap lock must be held in write and VMA write locks must be held on any VMA 35 * that is visible. 36 * 37 * Use the PAGETABLE_MOVE() macro to initialise this struct. 38 * 39 * The old_addr and new_addr fields are updated as the page table move is 40 * executed. 41 * 42 * NOTE: The page table move is affected by reading from [old_addr, old_end), 43 * and old_addr may be updated for better page table alignment, so len_in 44 * represents the length of the range being copied as specified by the user. 45 */ 46 struct pagetable_move_control { 47 struct vm_area_struct *old; /* Source VMA. */ 48 struct vm_area_struct *new; /* Destination VMA. */ 49 unsigned long old_addr; /* Address from which the move begins. */ 50 unsigned long old_end; /* Exclusive address at which old range ends. */ 51 unsigned long new_addr; /* Address to move page tables to. */ 52 unsigned long len_in; /* Bytes to remap specified by user. */ 53 54 bool need_rmap_locks; /* Do rmap locks need to be taken? */ 55 bool for_stack; /* Is this an early temp stack being moved? */ 56 }; 57 58 #define PAGETABLE_MOVE(name, old_, new_, old_addr_, new_addr_, len_) \ 59 struct pagetable_move_control name = { \ 60 .old = old_, \ 61 .new = new_, \ 62 .old_addr = old_addr_, \ 63 .old_end = (old_addr_) + (len_), \ 64 .new_addr = new_addr_, \ 65 .len_in = len_, \ 66 } 67 68 /* 69 * The set of flags that only affect watermark checking and reclaim 70 * behaviour. This is used by the MM to obey the caller constraints 71 * about IO, FS and watermark checking while ignoring placement 72 * hints such as HIGHMEM usage. 73 */ 74 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\ 75 __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\ 76 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\ 77 __GFP_NOLOCKDEP) 78 79 /* The GFP flags allowed during early boot */ 80 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS)) 81 82 /* Control allocation cpuset and node placement constraints */ 83 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE) 84 85 /* Do not use these with a slab allocator */ 86 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) 87 88 /* 89 * Different from WARN_ON_ONCE(), no warning will be issued 90 * when we specify __GFP_NOWARN. 91 */ 92 #define WARN_ON_ONCE_GFP(cond, gfp) ({ \ 93 static bool __section(".data..once") __warned; \ 94 int __ret_warn_once = !!(cond); \ 95 \ 96 if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \ 97 __warned = true; \ 98 WARN_ON(1); \ 99 } \ 100 unlikely(__ret_warn_once); \ 101 }) 102 103 void page_writeback_init(void); 104 105 /* 106 * If a 16GB hugetlb folio were mapped by PTEs of all of its 4kB pages, 107 * its nr_pages_mapped would be 0x400000: choose the ENTIRELY_MAPPED bit 108 * above that range, instead of 2*(PMD_SIZE/PAGE_SIZE). Hugetlb currently 109 * leaves nr_pages_mapped at 0, but avoid surprise if it participates later. 110 */ 111 #define ENTIRELY_MAPPED 0x800000 112 #define FOLIO_PAGES_MAPPED (ENTIRELY_MAPPED - 1) 113 114 /* 115 * Flags passed to __show_mem() and show_free_areas() to suppress output in 116 * various contexts. 117 */ 118 #define SHOW_MEM_FILTER_NODES (0x0001u) /* disallowed nodes */ 119 120 /* 121 * How many individual pages have an elevated _mapcount. Excludes 122 * the folio's entire_mapcount. 123 * 124 * Don't use this function outside of debugging code. 125 */ 126 static inline int folio_nr_pages_mapped(const struct folio *folio) 127 { 128 if (IS_ENABLED(CONFIG_NO_PAGE_MAPCOUNT)) 129 return -1; 130 return atomic_read(&folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED; 131 } 132 133 /* 134 * Retrieve the first entry of a folio based on a provided entry within the 135 * folio. We cannot rely on folio->swap as there is no guarantee that it has 136 * been initialized. Used for calling arch_swap_restore() 137 */ 138 static inline swp_entry_t folio_swap(swp_entry_t entry, 139 const struct folio *folio) 140 { 141 swp_entry_t swap = { 142 .val = ALIGN_DOWN(entry.val, folio_nr_pages(folio)), 143 }; 144 145 return swap; 146 } 147 148 static inline void *folio_raw_mapping(const struct folio *folio) 149 { 150 unsigned long mapping = (unsigned long)folio->mapping; 151 152 return (void *)(mapping & ~FOLIO_MAPPING_FLAGS); 153 } 154 155 /* 156 * This is a file-backed mapping, and is about to be memory mapped - invoke its 157 * mmap hook and safely handle error conditions. On error, VMA hooks will be 158 * mutated. 159 * 160 * @file: File which backs the mapping. 161 * @vma: VMA which we are mapping. 162 * 163 * Returns: 0 if success, error otherwise. 164 */ 165 static inline int mmap_file(struct file *file, struct vm_area_struct *vma) 166 { 167 int err = 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; is_swap_pte(pte) must be true and 329 * non_swap_entry() must be false. 330 * @delta: The direction and the offset we are moving; forward if delta 331 * is positive; backward if delta is negative 332 * 333 * Moves the swap offset, while maintaining all other fields, including 334 * swap type, and any swp pte bits. The resulting pte is returned. 335 */ 336 static inline pte_t pte_move_swp_offset(pte_t pte, long delta) 337 { 338 swp_entry_t entry = pte_to_swp_entry(pte); 339 pte_t new = __swp_entry_to_pte(__swp_entry(swp_type(entry), 340 (swp_offset(entry) + delta))); 341 342 if (pte_swp_soft_dirty(pte)) 343 new = pte_swp_mksoft_dirty(new); 344 if (pte_swp_exclusive(pte)) 345 new = pte_swp_mkexclusive(new); 346 if (pte_swp_uffd_wp(pte)) 347 new = pte_swp_mkuffd_wp(new); 348 349 return new; 350 } 351 352 353 /** 354 * pte_next_swp_offset - Increment the swap entry offset field of a swap pte. 355 * @pte: The initial pte state; is_swap_pte(pte) must be true and 356 * non_swap_entry() must be false. 357 * 358 * Increments the swap offset, while maintaining all other fields, including 359 * swap type, and any swp pte bits. The resulting pte is returned. 360 */ 361 static inline pte_t pte_next_swp_offset(pte_t pte) 362 { 363 return pte_move_swp_offset(pte, 1); 364 } 365 366 /** 367 * swap_pte_batch - detect a PTE batch for a set of contiguous swap entries 368 * @start_ptep: Page table pointer for the first entry. 369 * @max_nr: The maximum number of table entries to consider. 370 * @pte: Page table entry for the first entry. 371 * 372 * Detect a batch of contiguous swap entries: consecutive (non-present) PTEs 373 * containing swap entries all with consecutive offsets and targeting the same 374 * swap type, all with matching swp pte bits. 375 * 376 * max_nr must be at least one and must be limited by the caller so scanning 377 * cannot exceed a single page table. 378 * 379 * Return: the number of table entries in the batch. 380 */ 381 static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte) 382 { 383 pte_t expected_pte = pte_next_swp_offset(pte); 384 const pte_t *end_ptep = start_ptep + max_nr; 385 swp_entry_t entry = pte_to_swp_entry(pte); 386 pte_t *ptep = start_ptep + 1; 387 unsigned short cgroup_id; 388 389 VM_WARN_ON(max_nr < 1); 390 VM_WARN_ON(!is_swap_pte(pte)); 391 VM_WARN_ON(non_swap_entry(entry)); 392 393 cgroup_id = lookup_swap_cgroup_id(entry); 394 while (ptep < end_ptep) { 395 pte = ptep_get(ptep); 396 397 if (!pte_same(pte, expected_pte)) 398 break; 399 if (lookup_swap_cgroup_id(pte_to_swp_entry(pte)) != 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 #ifdef CONFIG_NUMA 542 int user_proactive_reclaim(char *buf, 543 struct mem_cgroup *memcg, pg_data_t *pgdat); 544 #else 545 static inline int user_proactive_reclaim(char *buf, 546 struct mem_cgroup *memcg, pg_data_t *pgdat) 547 { 548 return 0; 549 } 550 #endif 551 552 /* 553 * in mm/rmap.c: 554 */ 555 pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 556 557 /* 558 * in mm/page_alloc.c 559 */ 560 #define K(x) ((x) << (PAGE_SHIFT-10)) 561 562 extern char * const zone_names[MAX_NR_ZONES]; 563 564 /* perform sanity checks on struct pages being allocated or freed */ 565 DECLARE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled); 566 567 extern int min_free_kbytes; 568 extern int defrag_mode; 569 570 void setup_per_zone_wmarks(void); 571 void calculate_min_free_kbytes(void); 572 int __meminit init_per_zone_wmark_min(void); 573 void page_alloc_sysctl_init(void); 574 575 /* 576 * Structure for holding the mostly immutable allocation parameters passed 577 * between functions involved in allocations, including the alloc_pages* 578 * family of functions. 579 * 580 * nodemask, migratetype and highest_zoneidx are initialized only once in 581 * __alloc_pages() and then never change. 582 * 583 * zonelist, preferred_zone and highest_zoneidx are set first in 584 * __alloc_pages() for the fast path, and might be later changed 585 * in __alloc_pages_slowpath(). All other functions pass the whole structure 586 * by a const pointer. 587 */ 588 struct alloc_context { 589 struct zonelist *zonelist; 590 nodemask_t *nodemask; 591 struct zoneref *preferred_zoneref; 592 int migratetype; 593 594 /* 595 * highest_zoneidx represents highest usable zone index of 596 * the allocation request. Due to the nature of the zone, 597 * memory on lower zone than the highest_zoneidx will be 598 * protected by lowmem_reserve[highest_zoneidx]. 599 * 600 * highest_zoneidx is also used by reclaim/compaction to limit 601 * the target zone since higher zone than this index cannot be 602 * usable for this allocation request. 603 */ 604 enum zone_type highest_zoneidx; 605 bool spread_dirty_pages; 606 }; 607 608 /* 609 * This function returns the order of a free page in the buddy system. In 610 * general, page_zone(page)->lock must be held by the caller to prevent the 611 * page from being allocated in parallel and returning garbage as the order. 612 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 613 * page cannot be allocated or merged in parallel. Alternatively, it must 614 * handle invalid values gracefully, and use buddy_order_unsafe() below. 615 */ 616 static inline unsigned int buddy_order(struct page *page) 617 { 618 /* PageBuddy() must be checked by the caller */ 619 return page_private(page); 620 } 621 622 /* 623 * Like buddy_order(), but for callers who cannot afford to hold the zone lock. 624 * PageBuddy() should be checked first by the caller to minimize race window, 625 * and invalid values must be handled gracefully. 626 * 627 * READ_ONCE is used so that if the caller assigns the result into a local 628 * variable and e.g. tests it for valid range before using, the compiler cannot 629 * decide to remove the variable and inline the page_private(page) multiple 630 * times, potentially observing different values in the tests and the actual 631 * use of the result. 632 */ 633 #define buddy_order_unsafe(page) READ_ONCE(page_private(page)) 634 635 /* 636 * This function checks whether a page is free && is the buddy 637 * we can coalesce a page and its buddy if 638 * (a) the buddy is not in a hole (check before calling!) && 639 * (b) the buddy is in the buddy system && 640 * (c) a page and its buddy have the same order && 641 * (d) a page and its buddy are in the same zone. 642 * 643 * For recording whether a page is in the buddy system, we set PageBuddy. 644 * Setting, clearing, and testing PageBuddy is serialized by zone->lock. 645 * 646 * For recording page's order, we use page_private(page). 647 */ 648 static inline bool page_is_buddy(struct page *page, struct page *buddy, 649 unsigned int order) 650 { 651 if (!page_is_guard(buddy) && !PageBuddy(buddy)) 652 return false; 653 654 if (buddy_order(buddy) != order) 655 return false; 656 657 /* 658 * zone check is done late to avoid uselessly calculating 659 * zone/node ids for pages that could never merge. 660 */ 661 if (page_zone_id(page) != page_zone_id(buddy)) 662 return false; 663 664 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); 665 666 return true; 667 } 668 669 /* 670 * Locate the struct page for both the matching buddy in our 671 * pair (buddy1) and the combined O(n+1) page they form (page). 672 * 673 * 1) Any buddy B1 will have an order O twin B2 which satisfies 674 * the following equation: 675 * B2 = B1 ^ (1 << O) 676 * For example, if the starting buddy (buddy2) is #8 its order 677 * 1 buddy is #10: 678 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 679 * 680 * 2) Any buddy B will have an order O+1 parent P which 681 * satisfies the following equation: 682 * P = B & ~(1 << O) 683 * 684 * Assumption: *_mem_map is contiguous at least up to MAX_PAGE_ORDER 685 */ 686 static inline unsigned long 687 __find_buddy_pfn(unsigned long page_pfn, unsigned int order) 688 { 689 return page_pfn ^ (1 << order); 690 } 691 692 /* 693 * Find the buddy of @page and validate it. 694 * @page: The input page 695 * @pfn: The pfn of the page, it saves a call to page_to_pfn() when the 696 * function is used in the performance-critical __free_one_page(). 697 * @order: The order of the page 698 * @buddy_pfn: The output pointer to the buddy pfn, it also saves a call to 699 * page_to_pfn(). 700 * 701 * The found buddy can be a non PageBuddy, out of @page's zone, or its order is 702 * not the same as @page. The validation is necessary before use it. 703 * 704 * Return: the found buddy page or NULL if not found. 705 */ 706 static inline struct page *find_buddy_page_pfn(struct page *page, 707 unsigned long pfn, unsigned int order, unsigned long *buddy_pfn) 708 { 709 unsigned long __buddy_pfn = __find_buddy_pfn(pfn, order); 710 struct page *buddy; 711 712 buddy = page + (__buddy_pfn - pfn); 713 if (buddy_pfn) 714 *buddy_pfn = __buddy_pfn; 715 716 if (page_is_buddy(page, buddy, order)) 717 return buddy; 718 return NULL; 719 } 720 721 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn, 722 unsigned long end_pfn, struct zone *zone); 723 724 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn, 725 unsigned long end_pfn, struct zone *zone) 726 { 727 if (zone->contiguous) 728 return pfn_to_page(start_pfn); 729 730 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone); 731 } 732 733 void set_zone_contiguous(struct zone *zone); 734 bool pfn_range_intersects_zones(int nid, unsigned long start_pfn, 735 unsigned long nr_pages); 736 737 static inline void clear_zone_contiguous(struct zone *zone) 738 { 739 zone->contiguous = false; 740 } 741 742 extern int __isolate_free_page(struct page *page, unsigned int order); 743 extern void __putback_isolated_page(struct page *page, unsigned int order, 744 int mt); 745 extern void memblock_free_pages(struct page *page, unsigned long pfn, 746 unsigned int order); 747 extern void __free_pages_core(struct page *page, unsigned int order, 748 enum meminit_context context); 749 750 /* 751 * This will have no effect, other than possibly generating a warning, if the 752 * caller passes in a non-large folio. 753 */ 754 static inline void folio_set_order(struct folio *folio, unsigned int order) 755 { 756 if (WARN_ON_ONCE(!order || !folio_test_large(folio))) 757 return; 758 VM_WARN_ON_ONCE(order > MAX_FOLIO_ORDER); 759 760 folio->_flags_1 = (folio->_flags_1 & ~0xffUL) | order; 761 #ifdef NR_PAGES_IN_LARGE_FOLIO 762 folio->_nr_pages = 1U << order; 763 #endif 764 } 765 766 bool __folio_unqueue_deferred_split(struct folio *folio); 767 static inline bool folio_unqueue_deferred_split(struct folio *folio) 768 { 769 if (folio_order(folio) <= 1 || !folio_test_large_rmappable(folio)) 770 return false; 771 772 /* 773 * At this point, there is no one trying to add the folio to 774 * deferred_list. If folio is not in deferred_list, it's safe 775 * to check without acquiring the split_queue_lock. 776 */ 777 if (data_race(list_empty(&folio->_deferred_list))) 778 return false; 779 780 return __folio_unqueue_deferred_split(folio); 781 } 782 783 static inline struct folio *page_rmappable_folio(struct page *page) 784 { 785 struct folio *folio = (struct folio *)page; 786 787 if (folio && folio_test_large(folio)) 788 folio_set_large_rmappable(folio); 789 return folio; 790 } 791 792 static inline void prep_compound_head(struct page *page, unsigned int order) 793 { 794 struct folio *folio = (struct folio *)page; 795 796 folio_set_order(folio, order); 797 atomic_set(&folio->_large_mapcount, -1); 798 if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) 799 atomic_set(&folio->_nr_pages_mapped, 0); 800 if (IS_ENABLED(CONFIG_MM_ID)) { 801 folio->_mm_ids = 0; 802 folio->_mm_id_mapcount[0] = -1; 803 folio->_mm_id_mapcount[1] = -1; 804 } 805 if (IS_ENABLED(CONFIG_64BIT) || order > 1) { 806 atomic_set(&folio->_pincount, 0); 807 atomic_set(&folio->_entire_mapcount, -1); 808 } 809 if (order > 1) 810 INIT_LIST_HEAD(&folio->_deferred_list); 811 } 812 813 static inline void prep_compound_tail(struct page *head, int tail_idx) 814 { 815 struct page *p = head + tail_idx; 816 817 p->mapping = TAIL_MAPPING; 818 set_compound_head(p, head); 819 set_page_private(p, 0); 820 } 821 822 void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags); 823 extern bool free_pages_prepare(struct page *page, unsigned int order); 824 825 extern int user_min_free_kbytes; 826 827 struct page *__alloc_frozen_pages_noprof(gfp_t, unsigned int order, int nid, 828 nodemask_t *); 829 #define __alloc_frozen_pages(...) \ 830 alloc_hooks(__alloc_frozen_pages_noprof(__VA_ARGS__)) 831 void free_frozen_pages(struct page *page, unsigned int order); 832 void free_unref_folios(struct folio_batch *fbatch); 833 834 #ifdef CONFIG_NUMA 835 struct page *alloc_frozen_pages_noprof(gfp_t, unsigned int order); 836 #else 837 static inline struct page *alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order) 838 { 839 return __alloc_frozen_pages_noprof(gfp, order, numa_node_id(), NULL); 840 } 841 #endif 842 843 #define alloc_frozen_pages(...) \ 844 alloc_hooks(alloc_frozen_pages_noprof(__VA_ARGS__)) 845 846 struct page *alloc_frozen_pages_nolock_noprof(gfp_t gfp_flags, int nid, unsigned int order); 847 #define alloc_frozen_pages_nolock(...) \ 848 alloc_hooks(alloc_frozen_pages_nolock_noprof(__VA_ARGS__)) 849 850 extern void zone_pcp_reset(struct zone *zone); 851 extern void zone_pcp_disable(struct zone *zone); 852 extern void zone_pcp_enable(struct zone *zone); 853 extern void zone_pcp_init(struct zone *zone); 854 855 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align, 856 phys_addr_t min_addr, 857 int nid, bool exact_nid); 858 859 void memmap_init_range(unsigned long, int, unsigned long, unsigned long, 860 unsigned long, enum meminit_context, struct vmem_altmap *, int, 861 bool); 862 863 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 864 865 /* 866 * in mm/compaction.c 867 */ 868 /* 869 * compact_control is used to track pages being migrated and the free pages 870 * they are being migrated to during memory compaction. The free_pfn starts 871 * at the end of a zone and migrate_pfn begins at the start. Movable pages 872 * are moved to the end of a zone during a compaction run and the run 873 * completes when free_pfn <= migrate_pfn 874 */ 875 struct compact_control { 876 struct list_head freepages[NR_PAGE_ORDERS]; /* List of free pages to migrate to */ 877 struct list_head migratepages; /* List of pages being migrated */ 878 unsigned int nr_freepages; /* Number of isolated free pages */ 879 unsigned int nr_migratepages; /* Number of pages to migrate */ 880 unsigned long free_pfn; /* isolate_freepages search base */ 881 /* 882 * Acts as an in/out parameter to page isolation for migration. 883 * isolate_migratepages uses it as a search base. 884 * isolate_migratepages_block will update the value to the next pfn 885 * after the last isolated one. 886 */ 887 unsigned long migrate_pfn; 888 unsigned long fast_start_pfn; /* a pfn to start linear scan from */ 889 struct zone *zone; 890 unsigned long total_migrate_scanned; 891 unsigned long total_free_scanned; 892 unsigned short fast_search_fail;/* failures to use free list searches */ 893 short search_order; /* order to start a fast search at */ 894 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 895 int order; /* order a direct compactor needs */ 896 int migratetype; /* migratetype of direct compactor */ 897 const unsigned int alloc_flags; /* alloc flags of a direct compactor */ 898 const int highest_zoneidx; /* zone index of a direct compactor */ 899 enum migrate_mode mode; /* Async or sync migration mode */ 900 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 901 bool no_set_skip_hint; /* Don't mark blocks for skipping */ 902 bool ignore_block_suitable; /* Scan blocks considered unsuitable */ 903 bool direct_compaction; /* False from kcompactd or /proc/... */ 904 bool proactive_compaction; /* kcompactd proactive compaction */ 905 bool whole_zone; /* Whole zone should/has been scanned */ 906 bool contended; /* Signal lock contention */ 907 bool finish_pageblock; /* Scan the remainder of a pageblock. Used 908 * when there are potentially transient 909 * isolation or migration failures to 910 * ensure forward progress. 911 */ 912 bool alloc_contig; /* alloc_contig_range allocation */ 913 }; 914 915 /* 916 * Used in direct compaction when a page should be taken from the freelists 917 * immediately when one is created during the free path. 918 */ 919 struct capture_control { 920 struct compact_control *cc; 921 struct page *page; 922 }; 923 924 unsigned long 925 isolate_freepages_range(struct compact_control *cc, 926 unsigned long start_pfn, unsigned long end_pfn); 927 int 928 isolate_migratepages_range(struct compact_control *cc, 929 unsigned long low_pfn, unsigned long end_pfn); 930 931 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */ 932 void init_cma_reserved_pageblock(struct page *page); 933 934 #endif /* CONFIG_COMPACTION || CONFIG_CMA */ 935 936 struct cma; 937 938 #ifdef CONFIG_CMA 939 void *cma_reserve_early(struct cma *cma, unsigned long size); 940 void init_cma_pageblock(struct page *page); 941 #else 942 static inline void *cma_reserve_early(struct cma *cma, unsigned long size) 943 { 944 return NULL; 945 } 946 static inline void init_cma_pageblock(struct page *page) 947 { 948 } 949 #endif 950 951 952 int find_suitable_fallback(struct free_area *area, unsigned int order, 953 int migratetype, bool claimable); 954 955 static inline bool free_area_empty(struct free_area *area, int migratetype) 956 { 957 return list_empty(&area->free_list[migratetype]); 958 } 959 960 /* mm/util.c */ 961 struct anon_vma *folio_anon_vma(const struct folio *folio); 962 963 #ifdef CONFIG_MMU 964 void unmap_mapping_folio(struct folio *folio); 965 extern long populate_vma_page_range(struct vm_area_struct *vma, 966 unsigned long start, unsigned long end, int *locked); 967 extern long faultin_page_range(struct mm_struct *mm, unsigned long start, 968 unsigned long end, bool write, int *locked); 969 bool mlock_future_ok(const struct mm_struct *mm, vm_flags_t vm_flags, 970 unsigned long bytes); 971 972 /* 973 * NOTE: This function can't tell whether the folio is "fully mapped" in the 974 * range. 975 * "fully mapped" means all the pages of folio is associated with the page 976 * table of range while this function just check whether the folio range is 977 * within the range [start, end). Function caller needs to do page table 978 * check if it cares about the page table association. 979 * 980 * Typical usage (like mlock or madvise) is: 981 * Caller knows at least 1 page of folio is associated with page table of VMA 982 * and the range [start, end) is intersect with the VMA range. Caller wants 983 * to know whether the folio is fully associated with the range. It calls 984 * this function to check whether the folio is in the range first. Then checks 985 * the page table to know whether the folio is fully mapped to the range. 986 */ 987 static inline bool 988 folio_within_range(struct folio *folio, struct vm_area_struct *vma, 989 unsigned long start, unsigned long end) 990 { 991 pgoff_t pgoff, addr; 992 unsigned long vma_pglen = vma_pages(vma); 993 994 VM_WARN_ON_FOLIO(folio_test_ksm(folio), folio); 995 if (start > end) 996 return false; 997 998 if (start < vma->vm_start) 999 start = vma->vm_start; 1000 1001 if (end > vma->vm_end) 1002 end = vma->vm_end; 1003 1004 pgoff = folio_pgoff(folio); 1005 1006 /* if folio start address is not in vma range */ 1007 if (!in_range(pgoff, vma->vm_pgoff, vma_pglen)) 1008 return false; 1009 1010 addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 1011 1012 return !(addr < start || end - addr < folio_size(folio)); 1013 } 1014 1015 static inline bool 1016 folio_within_vma(struct folio *folio, struct vm_area_struct *vma) 1017 { 1018 return folio_within_range(folio, vma, vma->vm_start, vma->vm_end); 1019 } 1020 1021 /* 1022 * mlock_vma_folio() and munlock_vma_folio(): 1023 * should be called with vma's mmap_lock held for read or write, 1024 * under page table lock for the pte/pmd being added or removed. 1025 * 1026 * mlock is usually called at the end of folio_add_*_rmap_*(), munlock at 1027 * the end of folio_remove_rmap_*(); but new anon folios are managed by 1028 * folio_add_lru_vma() calling mlock_new_folio(). 1029 */ 1030 void mlock_folio(struct folio *folio); 1031 static inline void mlock_vma_folio(struct folio *folio, 1032 struct vm_area_struct *vma) 1033 { 1034 /* 1035 * The VM_SPECIAL check here serves two purposes. 1036 * 1) VM_IO check prevents migration from double-counting during mlock. 1037 * 2) Although mmap_region() and mlock_fixup() take care that VM_LOCKED 1038 * is never left set on a VM_SPECIAL vma, there is an interval while 1039 * file->f_op->mmap() is using vm_insert_page(s), when VM_LOCKED may 1040 * still be set while VM_SPECIAL bits are added: so ignore it then. 1041 */ 1042 if (unlikely((vma->vm_flags & (VM_LOCKED|VM_SPECIAL)) == VM_LOCKED)) 1043 mlock_folio(folio); 1044 } 1045 1046 void munlock_folio(struct folio *folio); 1047 static inline void munlock_vma_folio(struct folio *folio, 1048 struct vm_area_struct *vma) 1049 { 1050 /* 1051 * munlock if the function is called. Ideally, we should only 1052 * do munlock if any page of folio is unmapped from VMA and 1053 * cause folio not fully mapped to VMA. 1054 * 1055 * But it's not easy to confirm that's the situation. So we 1056 * always munlock the folio and page reclaim will correct it 1057 * if it's wrong. 1058 */ 1059 if (unlikely(vma->vm_flags & VM_LOCKED)) 1060 munlock_folio(folio); 1061 } 1062 1063 void mlock_new_folio(struct folio *folio); 1064 bool need_mlock_drain(int cpu); 1065 void mlock_drain_local(void); 1066 void mlock_drain_remote(int cpu); 1067 1068 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 1069 1070 /** 1071 * vma_address - Find the virtual address a page range is mapped at 1072 * @vma: The vma which maps this object. 1073 * @pgoff: The page offset within its object. 1074 * @nr_pages: The number of pages to consider. 1075 * 1076 * If any page in this range is mapped by this VMA, return the first address 1077 * where any of these pages appear. Otherwise, return -EFAULT. 1078 */ 1079 static inline unsigned long vma_address(const struct vm_area_struct *vma, 1080 pgoff_t pgoff, unsigned long nr_pages) 1081 { 1082 unsigned long address; 1083 1084 if (pgoff >= vma->vm_pgoff) { 1085 address = vma->vm_start + 1086 ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 1087 /* Check for address beyond vma (or wrapped through 0?) */ 1088 if (address < vma->vm_start || address >= vma->vm_end) 1089 address = -EFAULT; 1090 } else if (pgoff + nr_pages - 1 >= vma->vm_pgoff) { 1091 /* Test above avoids possibility of wrap to 0 on 32-bit */ 1092 address = vma->vm_start; 1093 } else { 1094 address = -EFAULT; 1095 } 1096 return address; 1097 } 1098 1099 /* 1100 * Then at what user virtual address will none of the range be found in vma? 1101 * Assumes that vma_address() already returned a good starting address. 1102 */ 1103 static inline unsigned long vma_address_end(struct page_vma_mapped_walk *pvmw) 1104 { 1105 struct vm_area_struct *vma = pvmw->vma; 1106 pgoff_t pgoff; 1107 unsigned long address; 1108 1109 /* Common case, plus ->pgoff is invalid for KSM */ 1110 if (pvmw->nr_pages == 1) 1111 return pvmw->address + PAGE_SIZE; 1112 1113 pgoff = pvmw->pgoff + pvmw->nr_pages; 1114 address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 1115 /* Check for address beyond vma (or wrapped through 0?) */ 1116 if (address < vma->vm_start || address > vma->vm_end) 1117 address = vma->vm_end; 1118 return address; 1119 } 1120 1121 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, 1122 struct file *fpin) 1123 { 1124 int flags = vmf->flags; 1125 1126 if (fpin) 1127 return fpin; 1128 1129 /* 1130 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or 1131 * anything, so we only pin the file and drop the mmap_lock if only 1132 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt. 1133 */ 1134 if (fault_flag_allow_retry_first(flags) && 1135 !(flags & FAULT_FLAG_RETRY_NOWAIT)) { 1136 fpin = get_file(vmf->vma->vm_file); 1137 release_fault_lock(vmf); 1138 } 1139 return fpin; 1140 } 1141 #else /* !CONFIG_MMU */ 1142 static inline void unmap_mapping_folio(struct folio *folio) { } 1143 static inline void mlock_new_folio(struct folio *folio) { } 1144 static inline bool need_mlock_drain(int cpu) { return false; } 1145 static inline void mlock_drain_local(void) { } 1146 static inline void mlock_drain_remote(int cpu) { } 1147 static inline void vunmap_range_noflush(unsigned long start, unsigned long end) 1148 { 1149 } 1150 #endif /* !CONFIG_MMU */ 1151 1152 /* Memory initialisation debug and verification */ 1153 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 1154 DECLARE_STATIC_KEY_TRUE(deferred_pages); 1155 1156 bool __init deferred_grow_zone(struct zone *zone, unsigned int order); 1157 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 1158 1159 void init_deferred_page(unsigned long pfn, int nid); 1160 1161 enum mminit_level { 1162 MMINIT_WARNING, 1163 MMINIT_VERIFY, 1164 MMINIT_TRACE 1165 }; 1166 1167 #ifdef CONFIG_DEBUG_MEMORY_INIT 1168 1169 extern int mminit_loglevel; 1170 1171 #define mminit_dprintk(level, prefix, fmt, arg...) \ 1172 do { \ 1173 if (level < mminit_loglevel) { \ 1174 if (level <= MMINIT_WARNING) \ 1175 pr_warn("mminit::" prefix " " fmt, ##arg); \ 1176 else \ 1177 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 1178 } \ 1179 } while (0) 1180 1181 extern void mminit_verify_pageflags_layout(void); 1182 extern void mminit_verify_zonelist(void); 1183 #else 1184 1185 static inline void mminit_dprintk(enum mminit_level level, 1186 const char *prefix, const char *fmt, ...) 1187 { 1188 } 1189 1190 static inline void mminit_verify_pageflags_layout(void) 1191 { 1192 } 1193 1194 static inline void mminit_verify_zonelist(void) 1195 { 1196 } 1197 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 1198 1199 #define NODE_RECLAIM_NOSCAN -2 1200 #define NODE_RECLAIM_FULL -1 1201 #define NODE_RECLAIM_SOME 0 1202 #define NODE_RECLAIM_SUCCESS 1 1203 1204 #ifdef CONFIG_NUMA 1205 extern int node_reclaim_mode; 1206 1207 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); 1208 extern int find_next_best_node(int node, nodemask_t *used_node_mask); 1209 #else 1210 #define node_reclaim_mode 0 1211 1212 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, 1213 unsigned int order) 1214 { 1215 return NODE_RECLAIM_NOSCAN; 1216 } 1217 static inline int find_next_best_node(int node, nodemask_t *used_node_mask) 1218 { 1219 return NUMA_NO_NODE; 1220 } 1221 #endif 1222 1223 static inline bool node_reclaim_enabled(void) 1224 { 1225 /* Is any node_reclaim_mode bit set? */ 1226 return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP); 1227 } 1228 1229 /* 1230 * mm/memory-failure.c 1231 */ 1232 #ifdef CONFIG_MEMORY_FAILURE 1233 int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill); 1234 void shake_folio(struct folio *folio); 1235 typedef int hwpoison_filter_func_t(struct page *p); 1236 void hwpoison_filter_register(hwpoison_filter_func_t *filter); 1237 void hwpoison_filter_unregister(void); 1238 1239 #define MAGIC_HWPOISON 0x48575053U /* HWPS */ 1240 void SetPageHWPoisonTakenOff(struct page *page); 1241 void ClearPageHWPoisonTakenOff(struct page *page); 1242 bool take_page_off_buddy(struct page *page); 1243 bool put_page_back_buddy(struct page *page); 1244 struct task_struct *task_early_kill(struct task_struct *tsk, int force_early); 1245 void add_to_kill_ksm(struct task_struct *tsk, const struct page *p, 1246 struct vm_area_struct *vma, struct list_head *to_kill, 1247 unsigned long ksm_addr); 1248 unsigned long page_mapped_in_vma(const struct page *page, 1249 struct vm_area_struct *vma); 1250 1251 #else 1252 static inline int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill) 1253 { 1254 return -EBUSY; 1255 } 1256 #endif 1257 1258 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 1259 unsigned long, unsigned long, 1260 unsigned long, unsigned long); 1261 1262 extern void set_pageblock_order(void); 1263 unsigned long reclaim_pages(struct list_head *folio_list); 1264 unsigned int reclaim_clean_pages_from_list(struct zone *zone, 1265 struct list_head *folio_list); 1266 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 1267 #define ALLOC_WMARK_MIN WMARK_MIN 1268 #define ALLOC_WMARK_LOW WMARK_LOW 1269 #define ALLOC_WMARK_HIGH WMARK_HIGH 1270 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 1271 1272 /* Mask to get the watermark bits */ 1273 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 1274 1275 /* 1276 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we 1277 * cannot assume a reduced access to memory reserves is sufficient for 1278 * !MMU 1279 */ 1280 #ifdef CONFIG_MMU 1281 #define ALLOC_OOM 0x08 1282 #else 1283 #define ALLOC_OOM ALLOC_NO_WATERMARKS 1284 #endif 1285 1286 #define ALLOC_NON_BLOCK 0x10 /* Caller cannot block. Allow access 1287 * to 25% of the min watermark or 1288 * 62.5% if __GFP_HIGH is set. 1289 */ 1290 #define ALLOC_MIN_RESERVE 0x20 /* __GFP_HIGH set. Allow access to 50% 1291 * of the min watermark. 1292 */ 1293 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1294 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 1295 #ifdef CONFIG_ZONE_DMA32 1296 #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */ 1297 #else 1298 #define ALLOC_NOFRAGMENT 0x0 1299 #endif 1300 #define ALLOC_HIGHATOMIC 0x200 /* Allows access to MIGRATE_HIGHATOMIC */ 1301 #define ALLOC_TRYLOCK 0x400 /* Only use spin_trylock in allocation path */ 1302 #define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */ 1303 1304 /* Flags that allow allocations below the min watermark. */ 1305 #define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM) 1306 1307 enum ttu_flags; 1308 struct tlbflush_unmap_batch; 1309 1310 1311 /* 1312 * only for MM internal work items which do not depend on 1313 * any allocations or locks which might depend on allocations 1314 */ 1315 extern struct workqueue_struct *mm_percpu_wq; 1316 1317 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 1318 void try_to_unmap_flush(void); 1319 void try_to_unmap_flush_dirty(void); 1320 void flush_tlb_batched_pending(struct mm_struct *mm); 1321 #else 1322 static inline void try_to_unmap_flush(void) 1323 { 1324 } 1325 static inline void try_to_unmap_flush_dirty(void) 1326 { 1327 } 1328 static inline void flush_tlb_batched_pending(struct mm_struct *mm) 1329 { 1330 } 1331 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 1332 1333 extern const struct trace_print_flags pageflag_names[]; 1334 extern const struct trace_print_flags vmaflag_names[]; 1335 extern const struct trace_print_flags gfpflag_names[]; 1336 1337 void setup_zone_pageset(struct zone *zone); 1338 1339 struct migration_target_control { 1340 int nid; /* preferred node id */ 1341 nodemask_t *nmask; 1342 gfp_t gfp_mask; 1343 enum migrate_reason reason; 1344 }; 1345 1346 /* 1347 * mm/filemap.c 1348 */ 1349 size_t splice_folio_into_pipe(struct pipe_inode_info *pipe, 1350 struct folio *folio, loff_t fpos, size_t size); 1351 1352 /* 1353 * mm/vmalloc.c 1354 */ 1355 #ifdef CONFIG_MMU 1356 void __init vmalloc_init(void); 1357 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end, 1358 pgprot_t prot, struct page **pages, unsigned int page_shift); 1359 unsigned int get_vm_area_page_order(struct vm_struct *vm); 1360 #else 1361 static inline void vmalloc_init(void) 1362 { 1363 } 1364 1365 static inline 1366 int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end, 1367 pgprot_t prot, struct page **pages, unsigned int page_shift) 1368 { 1369 return -EINVAL; 1370 } 1371 #endif 1372 1373 int __must_check __vmap_pages_range_noflush(unsigned long addr, 1374 unsigned long end, pgprot_t prot, 1375 struct page **pages, unsigned int page_shift); 1376 1377 void vunmap_range_noflush(unsigned long start, unsigned long end); 1378 1379 void __vunmap_range_noflush(unsigned long start, unsigned long end); 1380 1381 int numa_migrate_check(struct folio *folio, struct vm_fault *vmf, 1382 unsigned long addr, int *flags, bool writable, 1383 int *last_cpupid); 1384 1385 void free_zone_device_folio(struct folio *folio); 1386 int migrate_device_coherent_folio(struct folio *folio); 1387 1388 struct vm_struct *__get_vm_area_node(unsigned long size, 1389 unsigned long align, unsigned long shift, 1390 unsigned long vm_flags, unsigned long start, 1391 unsigned long end, int node, gfp_t gfp_mask, 1392 const void *caller); 1393 1394 /* 1395 * mm/gup.c 1396 */ 1397 int __must_check try_grab_folio(struct folio *folio, int refs, 1398 unsigned int flags); 1399 1400 /* 1401 * mm/huge_memory.c 1402 */ 1403 void touch_pud(struct vm_area_struct *vma, unsigned long addr, 1404 pud_t *pud, bool write); 1405 void touch_pmd(struct vm_area_struct *vma, unsigned long addr, 1406 pmd_t *pmd, bool write); 1407 1408 /* 1409 * Parses a string with mem suffixes into its order. Useful to parse kernel 1410 * parameters. 1411 */ 1412 static inline int get_order_from_str(const char *size_str, 1413 unsigned long valid_orders) 1414 { 1415 unsigned long size; 1416 char *endptr; 1417 int order; 1418 1419 size = memparse(size_str, &endptr); 1420 1421 if (!is_power_of_2(size)) 1422 return -EINVAL; 1423 order = get_order(size); 1424 if (BIT(order) & ~valid_orders) 1425 return -EINVAL; 1426 1427 return order; 1428 } 1429 1430 enum { 1431 /* mark page accessed */ 1432 FOLL_TOUCH = 1 << 16, 1433 /* a retry, previous pass started an IO */ 1434 FOLL_TRIED = 1 << 17, 1435 /* we are working on non-current tsk/mm */ 1436 FOLL_REMOTE = 1 << 18, 1437 /* pages must be released via unpin_user_page */ 1438 FOLL_PIN = 1 << 19, 1439 /* gup_fast: prevent fall-back to slow gup */ 1440 FOLL_FAST_ONLY = 1 << 20, 1441 /* allow unlocking the mmap lock */ 1442 FOLL_UNLOCKABLE = 1 << 21, 1443 /* VMA lookup+checks compatible with MADV_POPULATE_(READ|WRITE) */ 1444 FOLL_MADV_POPULATE = 1 << 22, 1445 }; 1446 1447 #define INTERNAL_GUP_FLAGS (FOLL_TOUCH | FOLL_TRIED | FOLL_REMOTE | FOLL_PIN | \ 1448 FOLL_FAST_ONLY | FOLL_UNLOCKABLE | \ 1449 FOLL_MADV_POPULATE) 1450 1451 /* 1452 * Indicates for which pages that are write-protected in the page table, 1453 * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that the 1454 * GUP pin will remain consistent with the pages mapped into the page tables 1455 * of the MM. 1456 * 1457 * Temporary unmapping of PageAnonExclusive() pages or clearing of 1458 * PageAnonExclusive() has to protect against concurrent GUP: 1459 * * Ordinary GUP: Using the PT lock 1460 * * GUP-fast and fork(): mm->write_protect_seq 1461 * * GUP-fast and KSM or temporary unmapping (swap, migration): see 1462 * folio_try_share_anon_rmap_*() 1463 * 1464 * Must be called with the (sub)page that's actually referenced via the 1465 * page table entry, which might not necessarily be the head page for a 1466 * PTE-mapped THP. 1467 * 1468 * If the vma is NULL, we're coming from the GUP-fast path and might have 1469 * to fallback to the slow path just to lookup the vma. 1470 */ 1471 static inline bool gup_must_unshare(struct vm_area_struct *vma, 1472 unsigned int flags, struct page *page) 1473 { 1474 /* 1475 * FOLL_WRITE is implicitly handled correctly as the page table entry 1476 * has to be writable -- and if it references (part of) an anonymous 1477 * folio, that part is required to be marked exclusive. 1478 */ 1479 if ((flags & (FOLL_WRITE | FOLL_PIN)) != FOLL_PIN) 1480 return false; 1481 /* 1482 * Note: PageAnon(page) is stable until the page is actually getting 1483 * freed. 1484 */ 1485 if (!PageAnon(page)) { 1486 /* 1487 * We only care about R/O long-term pining: R/O short-term 1488 * pinning does not have the semantics to observe successive 1489 * changes through the process page tables. 1490 */ 1491 if (!(flags & FOLL_LONGTERM)) 1492 return false; 1493 1494 /* We really need the vma ... */ 1495 if (!vma) 1496 return true; 1497 1498 /* 1499 * ... because we only care about writable private ("COW") 1500 * mappings where we have to break COW early. 1501 */ 1502 return is_cow_mapping(vma->vm_flags); 1503 } 1504 1505 /* Paired with a memory barrier in folio_try_share_anon_rmap_*(). */ 1506 if (IS_ENABLED(CONFIG_HAVE_GUP_FAST)) 1507 smp_rmb(); 1508 1509 /* 1510 * Note that KSM pages cannot be exclusive, and consequently, 1511 * cannot get pinned. 1512 */ 1513 return !PageAnonExclusive(page); 1514 } 1515 1516 extern bool mirrored_kernelcore; 1517 bool memblock_has_mirror(void); 1518 void memblock_free_all(void); 1519 1520 static __always_inline void vma_set_range(struct vm_area_struct *vma, 1521 unsigned long start, unsigned long end, 1522 pgoff_t pgoff) 1523 { 1524 vma->vm_start = start; 1525 vma->vm_end = end; 1526 vma->vm_pgoff = pgoff; 1527 } 1528 1529 static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma) 1530 { 1531 /* 1532 * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty 1533 * enablements, because when without soft-dirty being compiled in, 1534 * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY) 1535 * will be constantly true. 1536 */ 1537 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) 1538 return false; 1539 1540 /* 1541 * Soft-dirty is kind of special: its tracking is enabled when the 1542 * vma flags not set. 1543 */ 1544 return !(vma->vm_flags & VM_SOFTDIRTY); 1545 } 1546 1547 static inline bool pmd_needs_soft_dirty_wp(struct vm_area_struct *vma, pmd_t pmd) 1548 { 1549 return vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd); 1550 } 1551 1552 static inline bool pte_needs_soft_dirty_wp(struct vm_area_struct *vma, pte_t pte) 1553 { 1554 return vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte); 1555 } 1556 1557 void __meminit __init_single_page(struct page *page, unsigned long pfn, 1558 unsigned long zone, int nid); 1559 void __meminit __init_page_from_nid(unsigned long pfn, int nid); 1560 1561 /* shrinker related functions */ 1562 unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg, 1563 int priority); 1564 1565 #ifdef CONFIG_SHRINKER_DEBUG 1566 static inline __printf(2, 0) int shrinker_debugfs_name_alloc( 1567 struct shrinker *shrinker, const char *fmt, va_list ap) 1568 { 1569 shrinker->name = kvasprintf_const(GFP_KERNEL, fmt, ap); 1570 1571 return shrinker->name ? 0 : -ENOMEM; 1572 } 1573 1574 static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) 1575 { 1576 kfree_const(shrinker->name); 1577 shrinker->name = NULL; 1578 } 1579 1580 extern int shrinker_debugfs_add(struct shrinker *shrinker); 1581 extern struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, 1582 int *debugfs_id); 1583 extern void shrinker_debugfs_remove(struct dentry *debugfs_entry, 1584 int debugfs_id); 1585 #else /* CONFIG_SHRINKER_DEBUG */ 1586 static inline int shrinker_debugfs_add(struct shrinker *shrinker) 1587 { 1588 return 0; 1589 } 1590 static inline int shrinker_debugfs_name_alloc(struct shrinker *shrinker, 1591 const char *fmt, va_list ap) 1592 { 1593 return 0; 1594 } 1595 static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) 1596 { 1597 } 1598 static inline struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, 1599 int *debugfs_id) 1600 { 1601 *debugfs_id = -1; 1602 return NULL; 1603 } 1604 static inline void shrinker_debugfs_remove(struct dentry *debugfs_entry, 1605 int debugfs_id) 1606 { 1607 } 1608 #endif /* CONFIG_SHRINKER_DEBUG */ 1609 1610 /* Only track the nodes of mappings with shadow entries */ 1611 void workingset_update_node(struct xa_node *node); 1612 extern struct list_lru shadow_nodes; 1613 #define mapping_set_update(xas, mapping) do { \ 1614 if (!dax_mapping(mapping) && !shmem_mapping(mapping)) { \ 1615 xas_set_update(xas, workingset_update_node); \ 1616 xas_set_lru(xas, &shadow_nodes); \ 1617 } \ 1618 } while (0) 1619 1620 /* mremap.c */ 1621 unsigned long move_page_tables(struct pagetable_move_control *pmc); 1622 1623 #ifdef CONFIG_UNACCEPTED_MEMORY 1624 void accept_page(struct page *page); 1625 #else /* CONFIG_UNACCEPTED_MEMORY */ 1626 static inline void accept_page(struct page *page) 1627 { 1628 } 1629 #endif /* CONFIG_UNACCEPTED_MEMORY */ 1630 1631 /* pagewalk.c */ 1632 int walk_page_range_mm(struct mm_struct *mm, unsigned long start, 1633 unsigned long end, const struct mm_walk_ops *ops, 1634 void *private); 1635 int walk_page_range_debug(struct mm_struct *mm, unsigned long start, 1636 unsigned long end, const struct mm_walk_ops *ops, 1637 pgd_t *pgd, void *private); 1638 1639 /* pt_reclaim.c */ 1640 bool try_get_and_clear_pmd(struct mm_struct *mm, pmd_t *pmd, pmd_t *pmdval); 1641 void free_pte(struct mm_struct *mm, unsigned long addr, struct mmu_gather *tlb, 1642 pmd_t pmdval); 1643 void try_to_free_pte(struct mm_struct *mm, pmd_t *pmd, unsigned long addr, 1644 struct mmu_gather *tlb); 1645 1646 #ifdef CONFIG_PT_RECLAIM 1647 bool reclaim_pt_is_enabled(unsigned long start, unsigned long end, 1648 struct zap_details *details); 1649 #else 1650 static inline bool reclaim_pt_is_enabled(unsigned long start, unsigned long end, 1651 struct zap_details *details) 1652 { 1653 return false; 1654 } 1655 #endif /* CONFIG_PT_RECLAIM */ 1656 1657 void dup_mm_exe_file(struct mm_struct *mm, struct mm_struct *oldmm); 1658 int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm); 1659 1660 #endif /* __MM_INTERNAL_H */ 1661