1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* internal.h: mm/ internal definitions 3 * 4 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 #ifndef __MM_INTERNAL_H 8 #define __MM_INTERNAL_H 9 10 #include <linux/fs.h> 11 #include <linux/mm.h> 12 #include <linux/pagemap.h> 13 #include <linux/tracepoint-defs.h> 14 15 /* 16 * The set of flags that only affect watermark checking and reclaim 17 * behaviour. This is used by the MM to obey the caller constraints 18 * about IO, FS and watermark checking while ignoring placement 19 * hints such as HIGHMEM usage. 20 */ 21 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\ 22 __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\ 23 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\ 24 __GFP_ATOMIC) 25 26 /* The GFP flags allowed during early boot */ 27 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS)) 28 29 /* Control allocation cpuset and node placement constraints */ 30 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE) 31 32 /* Do not use these with a slab allocator */ 33 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) 34 35 void page_writeback_init(void); 36 37 vm_fault_t do_swap_page(struct vm_fault *vmf); 38 39 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, 40 unsigned long floor, unsigned long ceiling); 41 42 static inline bool can_madv_lru_vma(struct vm_area_struct *vma) 43 { 44 return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)); 45 } 46 47 void unmap_page_range(struct mmu_gather *tlb, 48 struct vm_area_struct *vma, 49 unsigned long addr, unsigned long end, 50 struct zap_details *details); 51 52 extern unsigned int __do_page_cache_readahead(struct address_space *mapping, 53 struct file *filp, pgoff_t offset, unsigned long nr_to_read, 54 unsigned long lookahead_size); 55 56 /* 57 * Submit IO for the read-ahead request in file_ra_state. 58 */ 59 static inline unsigned long ra_submit(struct file_ra_state *ra, 60 struct address_space *mapping, struct file *filp) 61 { 62 return __do_page_cache_readahead(mapping, filp, 63 ra->start, ra->size, ra->async_size); 64 } 65 66 /** 67 * page_evictable - test whether a page is evictable 68 * @page: the page to test 69 * 70 * Test whether page is evictable--i.e., should be placed on active/inactive 71 * lists vs unevictable list. 72 * 73 * Reasons page might not be evictable: 74 * (1) page's mapping marked unevictable 75 * (2) page is part of an mlocked VMA 76 * 77 */ 78 static inline bool page_evictable(struct page *page) 79 { 80 bool ret; 81 82 /* Prevent address_space of inode and swap cache from being freed */ 83 rcu_read_lock(); 84 ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page); 85 rcu_read_unlock(); 86 return ret; 87 } 88 89 /* 90 * Turn a non-refcounted page (->_refcount == 0) into refcounted with 91 * a count of one. 92 */ 93 static inline void set_page_refcounted(struct page *page) 94 { 95 VM_BUG_ON_PAGE(PageTail(page), page); 96 VM_BUG_ON_PAGE(page_ref_count(page), page); 97 set_page_count(page, 1); 98 } 99 100 extern unsigned long highest_memmap_pfn; 101 102 /* 103 * Maximum number of reclaim retries without progress before the OOM 104 * killer is consider the only way forward. 105 */ 106 #define MAX_RECLAIM_RETRIES 16 107 108 /* 109 * in mm/vmscan.c: 110 */ 111 extern int isolate_lru_page(struct page *page); 112 extern void putback_lru_page(struct page *page); 113 114 /* 115 * in mm/rmap.c: 116 */ 117 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 118 119 /* 120 * in mm/page_alloc.c 121 */ 122 123 /* 124 * Structure for holding the mostly immutable allocation parameters passed 125 * between functions involved in allocations, including the alloc_pages* 126 * family of functions. 127 * 128 * nodemask, migratetype and high_zoneidx are initialized only once in 129 * __alloc_pages_nodemask() and then never change. 130 * 131 * zonelist, preferred_zone and classzone_idx are set first in 132 * __alloc_pages_nodemask() for the fast path, and might be later changed 133 * in __alloc_pages_slowpath(). All other functions pass the whole strucure 134 * by a const pointer. 135 */ 136 struct alloc_context { 137 struct zonelist *zonelist; 138 nodemask_t *nodemask; 139 struct zoneref *preferred_zoneref; 140 int migratetype; 141 enum zone_type high_zoneidx; 142 bool spread_dirty_pages; 143 }; 144 145 #define ac_classzone_idx(ac) zonelist_zone_idx(ac->preferred_zoneref) 146 147 /* 148 * Locate the struct page for both the matching buddy in our 149 * pair (buddy1) and the combined O(n+1) page they form (page). 150 * 151 * 1) Any buddy B1 will have an order O twin B2 which satisfies 152 * the following equation: 153 * B2 = B1 ^ (1 << O) 154 * For example, if the starting buddy (buddy2) is #8 its order 155 * 1 buddy is #10: 156 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 157 * 158 * 2) Any buddy B will have an order O+1 parent P which 159 * satisfies the following equation: 160 * P = B & ~(1 << O) 161 * 162 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 163 */ 164 static inline unsigned long 165 __find_buddy_pfn(unsigned long page_pfn, unsigned int order) 166 { 167 return page_pfn ^ (1 << order); 168 } 169 170 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn, 171 unsigned long end_pfn, struct zone *zone); 172 173 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn, 174 unsigned long end_pfn, struct zone *zone) 175 { 176 if (zone->contiguous) 177 return pfn_to_page(start_pfn); 178 179 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone); 180 } 181 182 extern int __isolate_free_page(struct page *page, unsigned int order); 183 extern void memblock_free_pages(struct page *page, unsigned long pfn, 184 unsigned int order); 185 extern void __free_pages_core(struct page *page, unsigned int order); 186 extern void prep_compound_page(struct page *page, unsigned int order); 187 extern void post_alloc_hook(struct page *page, unsigned int order, 188 gfp_t gfp_flags); 189 extern int user_min_free_kbytes; 190 191 extern void zone_pcp_update(struct zone *zone); 192 extern void zone_pcp_reset(struct zone *zone); 193 194 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 195 196 /* 197 * in mm/compaction.c 198 */ 199 /* 200 * compact_control is used to track pages being migrated and the free pages 201 * they are being migrated to during memory compaction. The free_pfn starts 202 * at the end of a zone and migrate_pfn begins at the start. Movable pages 203 * are moved to the end of a zone during a compaction run and the run 204 * completes when free_pfn <= migrate_pfn 205 */ 206 struct compact_control { 207 struct list_head freepages; /* List of free pages to migrate to */ 208 struct list_head migratepages; /* List of pages being migrated */ 209 unsigned int nr_freepages; /* Number of isolated free pages */ 210 unsigned int nr_migratepages; /* Number of pages to migrate */ 211 unsigned long free_pfn; /* isolate_freepages search base */ 212 unsigned long migrate_pfn; /* isolate_migratepages search base */ 213 unsigned long fast_start_pfn; /* a pfn to start linear scan from */ 214 struct zone *zone; 215 unsigned long total_migrate_scanned; 216 unsigned long total_free_scanned; 217 unsigned short fast_search_fail;/* failures to use free list searches */ 218 short search_order; /* order to start a fast search at */ 219 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 220 int order; /* order a direct compactor needs */ 221 int migratetype; /* migratetype of direct compactor */ 222 const unsigned int alloc_flags; /* alloc flags of a direct compactor */ 223 const int classzone_idx; /* zone index of a direct compactor */ 224 enum migrate_mode mode; /* Async or sync migration mode */ 225 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 226 bool no_set_skip_hint; /* Don't mark blocks for skipping */ 227 bool ignore_block_suitable; /* Scan blocks considered unsuitable */ 228 bool direct_compaction; /* False from kcompactd or /proc/... */ 229 bool whole_zone; /* Whole zone should/has been scanned */ 230 bool contended; /* Signal lock or sched contention */ 231 bool rescan; /* Rescanning the same pageblock */ 232 bool alloc_contig; /* alloc_contig_range allocation */ 233 }; 234 235 /* 236 * Used in direct compaction when a page should be taken from the freelists 237 * immediately when one is created during the free path. 238 */ 239 struct capture_control { 240 struct compact_control *cc; 241 struct page *page; 242 }; 243 244 unsigned long 245 isolate_freepages_range(struct compact_control *cc, 246 unsigned long start_pfn, unsigned long end_pfn); 247 unsigned long 248 isolate_migratepages_range(struct compact_control *cc, 249 unsigned long low_pfn, unsigned long end_pfn); 250 int find_suitable_fallback(struct free_area *area, unsigned int order, 251 int migratetype, bool only_stealable, bool *can_steal); 252 253 #endif 254 255 /* 256 * This function returns the order of a free page in the buddy system. In 257 * general, page_zone(page)->lock must be held by the caller to prevent the 258 * page from being allocated in parallel and returning garbage as the order. 259 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 260 * page cannot be allocated or merged in parallel. Alternatively, it must 261 * handle invalid values gracefully, and use page_order_unsafe() below. 262 */ 263 static inline unsigned int page_order(struct page *page) 264 { 265 /* PageBuddy() must be checked by the caller */ 266 return page_private(page); 267 } 268 269 /* 270 * Like page_order(), but for callers who cannot afford to hold the zone lock. 271 * PageBuddy() should be checked first by the caller to minimize race window, 272 * and invalid values must be handled gracefully. 273 * 274 * READ_ONCE is used so that if the caller assigns the result into a local 275 * variable and e.g. tests it for valid range before using, the compiler cannot 276 * decide to remove the variable and inline the page_private(page) multiple 277 * times, potentially observing different values in the tests and the actual 278 * use of the result. 279 */ 280 #define page_order_unsafe(page) READ_ONCE(page_private(page)) 281 282 static inline bool is_cow_mapping(vm_flags_t flags) 283 { 284 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 285 } 286 287 /* 288 * These three helpers classifies VMAs for virtual memory accounting. 289 */ 290 291 /* 292 * Executable code area - executable, not writable, not stack 293 */ 294 static inline bool is_exec_mapping(vm_flags_t flags) 295 { 296 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; 297 } 298 299 /* 300 * Stack area - atomatically grows in one direction 301 * 302 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous: 303 * do_mmap() forbids all other combinations. 304 */ 305 static inline bool is_stack_mapping(vm_flags_t flags) 306 { 307 return (flags & VM_STACK) == VM_STACK; 308 } 309 310 /* 311 * Data area - private, writable, not stack 312 */ 313 static inline bool is_data_mapping(vm_flags_t flags) 314 { 315 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; 316 } 317 318 /* mm/util.c */ 319 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 320 struct vm_area_struct *prev); 321 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma); 322 323 #ifdef CONFIG_MMU 324 extern long populate_vma_page_range(struct vm_area_struct *vma, 325 unsigned long start, unsigned long end, int *nonblocking); 326 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 327 unsigned long start, unsigned long end); 328 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 329 { 330 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 331 } 332 333 /* 334 * must be called with vma's mmap_sem held for read or write, and page locked. 335 */ 336 extern void mlock_vma_page(struct page *page); 337 extern unsigned int munlock_vma_page(struct page *page); 338 339 /* 340 * Clear the page's PageMlocked(). This can be useful in a situation where 341 * we want to unconditionally remove a page from the pagecache -- e.g., 342 * on truncation or freeing. 343 * 344 * It is legal to call this function for any page, mlocked or not. 345 * If called for a page that is still mapped by mlocked vmas, all we do 346 * is revert to lazy LRU behaviour -- semantics are not broken. 347 */ 348 extern void clear_page_mlock(struct page *page); 349 350 /* 351 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page() 352 * (because that does not go through the full procedure of migration ptes): 353 * to migrate the Mlocked page flag; update statistics. 354 */ 355 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 356 { 357 if (TestClearPageMlocked(page)) { 358 int nr_pages = hpage_nr_pages(page); 359 360 /* Holding pmd lock, no change in irq context: __mod is safe */ 361 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); 362 SetPageMlocked(newpage); 363 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages); 364 } 365 } 366 367 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 368 369 /* 370 * At what user virtual address is page expected in @vma? 371 */ 372 static inline unsigned long 373 __vma_address(struct page *page, struct vm_area_struct *vma) 374 { 375 pgoff_t pgoff = page_to_pgoff(page); 376 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 377 } 378 379 static inline unsigned long 380 vma_address(struct page *page, struct vm_area_struct *vma) 381 { 382 unsigned long start, end; 383 384 start = __vma_address(page, vma); 385 end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1); 386 387 /* page should be within @vma mapping range */ 388 VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma); 389 390 return max(start, vma->vm_start); 391 } 392 393 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, 394 struct file *fpin) 395 { 396 int flags = vmf->flags; 397 398 if (fpin) 399 return fpin; 400 401 /* 402 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or 403 * anything, so we only pin the file and drop the mmap_sem if only 404 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt. 405 */ 406 if (fault_flag_allow_retry_first(flags) && 407 !(flags & FAULT_FLAG_RETRY_NOWAIT)) { 408 fpin = get_file(vmf->vma->vm_file); 409 up_read(&vmf->vma->vm_mm->mmap_sem); 410 } 411 return fpin; 412 } 413 414 #else /* !CONFIG_MMU */ 415 static inline void clear_page_mlock(struct page *page) { } 416 static inline void mlock_vma_page(struct page *page) { } 417 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 418 419 #endif /* !CONFIG_MMU */ 420 421 /* 422 * Return the mem_map entry representing the 'offset' subpage within 423 * the maximally aligned gigantic page 'base'. Handle any discontiguity 424 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 425 */ 426 static inline struct page *mem_map_offset(struct page *base, int offset) 427 { 428 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 429 return nth_page(base, offset); 430 return base + offset; 431 } 432 433 /* 434 * Iterator over all subpages within the maximally aligned gigantic 435 * page 'base'. Handle any discontiguity in the mem_map. 436 */ 437 static inline struct page *mem_map_next(struct page *iter, 438 struct page *base, int offset) 439 { 440 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 441 unsigned long pfn = page_to_pfn(base) + offset; 442 if (!pfn_valid(pfn)) 443 return NULL; 444 return pfn_to_page(pfn); 445 } 446 return iter + 1; 447 } 448 449 /* Memory initialisation debug and verification */ 450 enum mminit_level { 451 MMINIT_WARNING, 452 MMINIT_VERIFY, 453 MMINIT_TRACE 454 }; 455 456 #ifdef CONFIG_DEBUG_MEMORY_INIT 457 458 extern int mminit_loglevel; 459 460 #define mminit_dprintk(level, prefix, fmt, arg...) \ 461 do { \ 462 if (level < mminit_loglevel) { \ 463 if (level <= MMINIT_WARNING) \ 464 pr_warn("mminit::" prefix " " fmt, ##arg); \ 465 else \ 466 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 467 } \ 468 } while (0) 469 470 extern void mminit_verify_pageflags_layout(void); 471 extern void mminit_verify_zonelist(void); 472 #else 473 474 static inline void mminit_dprintk(enum mminit_level level, 475 const char *prefix, const char *fmt, ...) 476 { 477 } 478 479 static inline void mminit_verify_pageflags_layout(void) 480 { 481 } 482 483 static inline void mminit_verify_zonelist(void) 484 { 485 } 486 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 487 488 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 489 #if defined(CONFIG_SPARSEMEM) 490 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 491 unsigned long *end_pfn); 492 #else 493 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 494 unsigned long *end_pfn) 495 { 496 } 497 #endif /* CONFIG_SPARSEMEM */ 498 499 #define NODE_RECLAIM_NOSCAN -2 500 #define NODE_RECLAIM_FULL -1 501 #define NODE_RECLAIM_SOME 0 502 #define NODE_RECLAIM_SUCCESS 1 503 504 #ifdef CONFIG_NUMA 505 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); 506 #else 507 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, 508 unsigned int order) 509 { 510 return NODE_RECLAIM_NOSCAN; 511 } 512 #endif 513 514 extern int hwpoison_filter(struct page *p); 515 516 extern u32 hwpoison_filter_dev_major; 517 extern u32 hwpoison_filter_dev_minor; 518 extern u64 hwpoison_filter_flags_mask; 519 extern u64 hwpoison_filter_flags_value; 520 extern u64 hwpoison_filter_memcg; 521 extern u32 hwpoison_filter_enable; 522 523 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 524 unsigned long, unsigned long, 525 unsigned long, unsigned long); 526 527 extern void set_pageblock_order(void); 528 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 529 struct list_head *page_list); 530 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 531 #define ALLOC_WMARK_MIN WMARK_MIN 532 #define ALLOC_WMARK_LOW WMARK_LOW 533 #define ALLOC_WMARK_HIGH WMARK_HIGH 534 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 535 536 /* Mask to get the watermark bits */ 537 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 538 539 /* 540 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we 541 * cannot assume a reduced access to memory reserves is sufficient for 542 * !MMU 543 */ 544 #ifdef CONFIG_MMU 545 #define ALLOC_OOM 0x08 546 #else 547 #define ALLOC_OOM ALLOC_NO_WATERMARKS 548 #endif 549 550 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 551 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 552 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 553 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 554 #ifdef CONFIG_ZONE_DMA32 555 #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */ 556 #else 557 #define ALLOC_NOFRAGMENT 0x0 558 #endif 559 #define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */ 560 561 enum ttu_flags; 562 struct tlbflush_unmap_batch; 563 564 565 /* 566 * only for MM internal work items which do not depend on 567 * any allocations or locks which might depend on allocations 568 */ 569 extern struct workqueue_struct *mm_percpu_wq; 570 571 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 572 void try_to_unmap_flush(void); 573 void try_to_unmap_flush_dirty(void); 574 void flush_tlb_batched_pending(struct mm_struct *mm); 575 #else 576 static inline void try_to_unmap_flush(void) 577 { 578 } 579 static inline void try_to_unmap_flush_dirty(void) 580 { 581 } 582 static inline void flush_tlb_batched_pending(struct mm_struct *mm) 583 { 584 } 585 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 586 587 extern const struct trace_print_flags pageflag_names[]; 588 extern const struct trace_print_flags vmaflag_names[]; 589 extern const struct trace_print_flags gfpflag_names[]; 590 591 static inline bool is_migrate_highatomic(enum migratetype migratetype) 592 { 593 return migratetype == MIGRATE_HIGHATOMIC; 594 } 595 596 static inline bool is_migrate_highatomic_page(struct page *page) 597 { 598 return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC; 599 } 600 601 void setup_zone_pageset(struct zone *zone); 602 extern struct page *alloc_new_node_page(struct page *page, unsigned long node); 603 #endif /* __MM_INTERNAL_H */ 604