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