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