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 18 /* 19 * The set of flags that only affect watermark checking and reclaim 20 * behaviour. This is used by the MM to obey the caller constraints 21 * about IO, FS and watermark checking while ignoring placement 22 * hints such as HIGHMEM usage. 23 */ 24 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\ 25 __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\ 26 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC) 27 28 /* The GFP flags allowed during early boot */ 29 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS)) 30 31 /* Control allocation cpuset and node placement constraints */ 32 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE) 33 34 /* Do not use these with a slab allocator */ 35 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) 36 37 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, 38 unsigned long floor, unsigned long ceiling); 39 40 static inline void set_page_count(struct page *page, int v) 41 { 42 atomic_set(&page->_count, v); 43 } 44 45 extern int __do_page_cache_readahead(struct address_space *mapping, 46 struct file *filp, pgoff_t offset, unsigned long nr_to_read, 47 unsigned long lookahead_size); 48 49 /* 50 * Submit IO for the read-ahead request in file_ra_state. 51 */ 52 static inline unsigned long ra_submit(struct file_ra_state *ra, 53 struct address_space *mapping, struct file *filp) 54 { 55 return __do_page_cache_readahead(mapping, filp, 56 ra->start, ra->size, ra->async_size); 57 } 58 59 /* 60 * Turn a non-refcounted page (->_count == 0) into refcounted with 61 * a count of one. 62 */ 63 static inline void set_page_refcounted(struct page *page) 64 { 65 VM_BUG_ON_PAGE(PageTail(page), page); 66 VM_BUG_ON_PAGE(atomic_read(&page->_count), page); 67 set_page_count(page, 1); 68 } 69 70 extern unsigned long highest_memmap_pfn; 71 72 /* 73 * in mm/vmscan.c: 74 */ 75 extern int isolate_lru_page(struct page *page); 76 extern void putback_lru_page(struct page *page); 77 extern bool zone_reclaimable(struct zone *zone); 78 79 /* 80 * in mm/rmap.c: 81 */ 82 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 83 84 /* 85 * in mm/page_alloc.c 86 */ 87 88 /* 89 * Structure for holding the mostly immutable allocation parameters passed 90 * between functions involved in allocations, including the alloc_pages* 91 * family of functions. 92 * 93 * nodemask, migratetype and high_zoneidx are initialized only once in 94 * __alloc_pages_nodemask() and then never change. 95 * 96 * zonelist, preferred_zone and classzone_idx are set first in 97 * __alloc_pages_nodemask() for the fast path, and might be later changed 98 * in __alloc_pages_slowpath(). All other functions pass the whole strucure 99 * by a const pointer. 100 */ 101 struct alloc_context { 102 struct zonelist *zonelist; 103 nodemask_t *nodemask; 104 struct zone *preferred_zone; 105 int classzone_idx; 106 int migratetype; 107 enum zone_type high_zoneidx; 108 bool spread_dirty_pages; 109 }; 110 111 /* 112 * Locate the struct page for both the matching buddy in our 113 * pair (buddy1) and the combined O(n+1) page they form (page). 114 * 115 * 1) Any buddy B1 will have an order O twin B2 which satisfies 116 * the following equation: 117 * B2 = B1 ^ (1 << O) 118 * For example, if the starting buddy (buddy2) is #8 its order 119 * 1 buddy is #10: 120 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 121 * 122 * 2) Any buddy B will have an order O+1 parent P which 123 * satisfies the following equation: 124 * P = B & ~(1 << O) 125 * 126 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 127 */ 128 static inline unsigned long 129 __find_buddy_index(unsigned long page_idx, unsigned int order) 130 { 131 return page_idx ^ (1 << order); 132 } 133 134 extern int __isolate_free_page(struct page *page, unsigned int order); 135 extern void __free_pages_bootmem(struct page *page, unsigned long pfn, 136 unsigned int order); 137 extern void prep_compound_page(struct page *page, unsigned int order); 138 #ifdef CONFIG_MEMORY_FAILURE 139 extern bool is_free_buddy_page(struct page *page); 140 #endif 141 extern int user_min_free_kbytes; 142 143 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 144 145 /* 146 * in mm/compaction.c 147 */ 148 /* 149 * compact_control is used to track pages being migrated and the free pages 150 * they are being migrated to during memory compaction. The free_pfn starts 151 * at the end of a zone and migrate_pfn begins at the start. Movable pages 152 * are moved to the end of a zone during a compaction run and the run 153 * completes when free_pfn <= migrate_pfn 154 */ 155 struct compact_control { 156 struct list_head freepages; /* List of free pages to migrate to */ 157 struct list_head migratepages; /* List of pages being migrated */ 158 unsigned long nr_freepages; /* Number of isolated free pages */ 159 unsigned long nr_migratepages; /* Number of pages to migrate */ 160 unsigned long free_pfn; /* isolate_freepages search base */ 161 unsigned long migrate_pfn; /* isolate_migratepages search base */ 162 unsigned long last_migrated_pfn;/* Not yet flushed page being freed */ 163 enum migrate_mode mode; /* Async or sync migration mode */ 164 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 165 int order; /* order a direct compactor needs */ 166 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 167 const int alloc_flags; /* alloc flags of a direct compactor */ 168 const int classzone_idx; /* zone index of a direct compactor */ 169 struct zone *zone; 170 int contended; /* Signal need_sched() or lock 171 * contention detected during 172 * compaction 173 */ 174 }; 175 176 unsigned long 177 isolate_freepages_range(struct compact_control *cc, 178 unsigned long start_pfn, unsigned long end_pfn); 179 unsigned long 180 isolate_migratepages_range(struct compact_control *cc, 181 unsigned long low_pfn, unsigned long end_pfn); 182 int find_suitable_fallback(struct free_area *area, unsigned int order, 183 int migratetype, bool only_stealable, bool *can_steal); 184 185 #endif 186 187 /* 188 * This function returns the order of a free page in the buddy system. In 189 * general, page_zone(page)->lock must be held by the caller to prevent the 190 * page from being allocated in parallel and returning garbage as the order. 191 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 192 * page cannot be allocated or merged in parallel. Alternatively, it must 193 * handle invalid values gracefully, and use page_order_unsafe() below. 194 */ 195 static inline unsigned int page_order(struct page *page) 196 { 197 /* PageBuddy() must be checked by the caller */ 198 return page_private(page); 199 } 200 201 /* 202 * Like page_order(), but for callers who cannot afford to hold the zone lock. 203 * PageBuddy() should be checked first by the caller to minimize race window, 204 * and invalid values must be handled gracefully. 205 * 206 * READ_ONCE is used so that if the caller assigns the result into a local 207 * variable and e.g. tests it for valid range before using, the compiler cannot 208 * decide to remove the variable and inline the page_private(page) multiple 209 * times, potentially observing different values in the tests and the actual 210 * use of the result. 211 */ 212 #define page_order_unsafe(page) READ_ONCE(page_private(page)) 213 214 static inline bool is_cow_mapping(vm_flags_t flags) 215 { 216 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 217 } 218 219 /* 220 * These three helpers classifies VMAs for virtual memory accounting. 221 */ 222 223 /* 224 * Executable code area - executable, not writable, not stack 225 */ 226 static inline bool is_exec_mapping(vm_flags_t flags) 227 { 228 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; 229 } 230 231 /* 232 * Stack area - atomatically grows in one direction 233 * 234 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous: 235 * do_mmap() forbids all other combinations. 236 */ 237 static inline bool is_stack_mapping(vm_flags_t flags) 238 { 239 return (flags & VM_STACK) == VM_STACK; 240 } 241 242 /* 243 * Data area - private, writable, not stack 244 */ 245 static inline bool is_data_mapping(vm_flags_t flags) 246 { 247 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; 248 } 249 250 /* mm/util.c */ 251 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 252 struct vm_area_struct *prev, struct rb_node *rb_parent); 253 254 #ifdef CONFIG_MMU 255 extern long populate_vma_page_range(struct vm_area_struct *vma, 256 unsigned long start, unsigned long end, int *nonblocking); 257 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 258 unsigned long start, unsigned long end); 259 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 260 { 261 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 262 } 263 264 /* 265 * must be called with vma's mmap_sem held for read or write, and page locked. 266 */ 267 extern void mlock_vma_page(struct page *page); 268 extern unsigned int munlock_vma_page(struct page *page); 269 270 /* 271 * Clear the page's PageMlocked(). This can be useful in a situation where 272 * we want to unconditionally remove a page from the pagecache -- e.g., 273 * on truncation or freeing. 274 * 275 * It is legal to call this function for any page, mlocked or not. 276 * If called for a page that is still mapped by mlocked vmas, all we do 277 * is revert to lazy LRU behaviour -- semantics are not broken. 278 */ 279 extern void clear_page_mlock(struct page *page); 280 281 /* 282 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page() 283 * (because that does not go through the full procedure of migration ptes): 284 * to migrate the Mlocked page flag; update statistics. 285 */ 286 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 287 { 288 if (TestClearPageMlocked(page)) { 289 int nr_pages = hpage_nr_pages(page); 290 291 /* Holding pmd lock, no change in irq context: __mod is safe */ 292 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); 293 SetPageMlocked(newpage); 294 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages); 295 } 296 } 297 298 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 299 300 /* 301 * At what user virtual address is page expected in @vma? 302 */ 303 static inline unsigned long 304 __vma_address(struct page *page, struct vm_area_struct *vma) 305 { 306 pgoff_t pgoff = page_to_pgoff(page); 307 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 308 } 309 310 static inline unsigned long 311 vma_address(struct page *page, struct vm_area_struct *vma) 312 { 313 unsigned long address = __vma_address(page, vma); 314 315 /* page should be within @vma mapping range */ 316 VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma); 317 318 return address; 319 } 320 321 #else /* !CONFIG_MMU */ 322 static inline void clear_page_mlock(struct page *page) { } 323 static inline void mlock_vma_page(struct page *page) { } 324 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 325 326 #endif /* !CONFIG_MMU */ 327 328 /* 329 * Return the mem_map entry representing the 'offset' subpage within 330 * the maximally aligned gigantic page 'base'. Handle any discontiguity 331 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 332 */ 333 static inline struct page *mem_map_offset(struct page *base, int offset) 334 { 335 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 336 return nth_page(base, offset); 337 return base + offset; 338 } 339 340 /* 341 * Iterator over all subpages within the maximally aligned gigantic 342 * page 'base'. Handle any discontiguity in the mem_map. 343 */ 344 static inline struct page *mem_map_next(struct page *iter, 345 struct page *base, int offset) 346 { 347 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 348 unsigned long pfn = page_to_pfn(base) + offset; 349 if (!pfn_valid(pfn)) 350 return NULL; 351 return pfn_to_page(pfn); 352 } 353 return iter + 1; 354 } 355 356 /* 357 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 358 * so all functions starting at paging_init should be marked __init 359 * in those cases. SPARSEMEM, however, allows for memory hotplug, 360 * and alloc_bootmem_node is not used. 361 */ 362 #ifdef CONFIG_SPARSEMEM 363 #define __paginginit __meminit 364 #else 365 #define __paginginit __init 366 #endif 367 368 /* Memory initialisation debug and verification */ 369 enum mminit_level { 370 MMINIT_WARNING, 371 MMINIT_VERIFY, 372 MMINIT_TRACE 373 }; 374 375 #ifdef CONFIG_DEBUG_MEMORY_INIT 376 377 extern int mminit_loglevel; 378 379 #define mminit_dprintk(level, prefix, fmt, arg...) \ 380 do { \ 381 if (level < mminit_loglevel) { \ 382 if (level <= MMINIT_WARNING) \ 383 printk(KERN_WARNING "mminit::" prefix " " fmt, ##arg); \ 384 else \ 385 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 386 } \ 387 } while (0) 388 389 extern void mminit_verify_pageflags_layout(void); 390 extern void mminit_verify_zonelist(void); 391 #else 392 393 static inline void mminit_dprintk(enum mminit_level level, 394 const char *prefix, const char *fmt, ...) 395 { 396 } 397 398 static inline void mminit_verify_pageflags_layout(void) 399 { 400 } 401 402 static inline void mminit_verify_zonelist(void) 403 { 404 } 405 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 406 407 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 408 #if defined(CONFIG_SPARSEMEM) 409 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 410 unsigned long *end_pfn); 411 #else 412 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 413 unsigned long *end_pfn) 414 { 415 } 416 #endif /* CONFIG_SPARSEMEM */ 417 418 #define ZONE_RECLAIM_NOSCAN -2 419 #define ZONE_RECLAIM_FULL -1 420 #define ZONE_RECLAIM_SOME 0 421 #define ZONE_RECLAIM_SUCCESS 1 422 423 extern int hwpoison_filter(struct page *p); 424 425 extern u32 hwpoison_filter_dev_major; 426 extern u32 hwpoison_filter_dev_minor; 427 extern u64 hwpoison_filter_flags_mask; 428 extern u64 hwpoison_filter_flags_value; 429 extern u64 hwpoison_filter_memcg; 430 extern u32 hwpoison_filter_enable; 431 432 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, 433 unsigned long, unsigned long, 434 unsigned long, unsigned long); 435 436 extern void set_pageblock_order(void); 437 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 438 struct list_head *page_list); 439 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 440 #define ALLOC_WMARK_MIN WMARK_MIN 441 #define ALLOC_WMARK_LOW WMARK_LOW 442 #define ALLOC_WMARK_HIGH WMARK_HIGH 443 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 444 445 /* Mask to get the watermark bits */ 446 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 447 448 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 449 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 450 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 451 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 452 #define ALLOC_FAIR 0x100 /* fair zone allocation */ 453 454 enum ttu_flags; 455 struct tlbflush_unmap_batch; 456 457 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 458 void try_to_unmap_flush(void); 459 void try_to_unmap_flush_dirty(void); 460 #else 461 static inline void try_to_unmap_flush(void) 462 { 463 } 464 static inline void try_to_unmap_flush_dirty(void) 465 { 466 } 467 468 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 469 #endif /* __MM_INTERNAL_H */ 470