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 /* mm/util.c */ 220 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 221 struct vm_area_struct *prev, struct rb_node *rb_parent); 222 223 #ifdef CONFIG_MMU 224 extern long populate_vma_page_range(struct vm_area_struct *vma, 225 unsigned long start, unsigned long end, int *nonblocking); 226 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 227 unsigned long start, unsigned long end); 228 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 229 { 230 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 231 } 232 233 /* 234 * must be called with vma's mmap_sem held for read or write, and page locked. 235 */ 236 extern void mlock_vma_page(struct page *page); 237 extern unsigned int munlock_vma_page(struct page *page); 238 239 /* 240 * Clear the page's PageMlocked(). This can be useful in a situation where 241 * we want to unconditionally remove a page from the pagecache -- e.g., 242 * on truncation or freeing. 243 * 244 * It is legal to call this function for any page, mlocked or not. 245 * If called for a page that is still mapped by mlocked vmas, all we do 246 * is revert to lazy LRU behaviour -- semantics are not broken. 247 */ 248 extern void clear_page_mlock(struct page *page); 249 250 /* 251 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page() 252 * (because that does not go through the full procedure of migration ptes): 253 * to migrate the Mlocked page flag; update statistics. 254 */ 255 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 256 { 257 if (TestClearPageMlocked(page)) { 258 int nr_pages = hpage_nr_pages(page); 259 260 /* Holding pmd lock, no change in irq context: __mod is safe */ 261 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); 262 SetPageMlocked(newpage); 263 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages); 264 } 265 } 266 267 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 268 269 /* 270 * At what user virtual address is page expected in @vma? 271 */ 272 static inline unsigned long 273 __vma_address(struct page *page, struct vm_area_struct *vma) 274 { 275 pgoff_t pgoff = page_to_pgoff(page); 276 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 277 } 278 279 static inline unsigned long 280 vma_address(struct page *page, struct vm_area_struct *vma) 281 { 282 unsigned long address = __vma_address(page, vma); 283 284 /* page should be within @vma mapping range */ 285 VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma); 286 287 return address; 288 } 289 290 #else /* !CONFIG_MMU */ 291 static inline void clear_page_mlock(struct page *page) { } 292 static inline void mlock_vma_page(struct page *page) { } 293 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 294 295 #endif /* !CONFIG_MMU */ 296 297 /* 298 * Return the mem_map entry representing the 'offset' subpage within 299 * the maximally aligned gigantic page 'base'. Handle any discontiguity 300 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 301 */ 302 static inline struct page *mem_map_offset(struct page *base, int offset) 303 { 304 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 305 return nth_page(base, offset); 306 return base + offset; 307 } 308 309 /* 310 * Iterator over all subpages within the maximally aligned gigantic 311 * page 'base'. Handle any discontiguity in the mem_map. 312 */ 313 static inline struct page *mem_map_next(struct page *iter, 314 struct page *base, int offset) 315 { 316 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 317 unsigned long pfn = page_to_pfn(base) + offset; 318 if (!pfn_valid(pfn)) 319 return NULL; 320 return pfn_to_page(pfn); 321 } 322 return iter + 1; 323 } 324 325 /* 326 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 327 * so all functions starting at paging_init should be marked __init 328 * in those cases. SPARSEMEM, however, allows for memory hotplug, 329 * and alloc_bootmem_node is not used. 330 */ 331 #ifdef CONFIG_SPARSEMEM 332 #define __paginginit __meminit 333 #else 334 #define __paginginit __init 335 #endif 336 337 /* Memory initialisation debug and verification */ 338 enum mminit_level { 339 MMINIT_WARNING, 340 MMINIT_VERIFY, 341 MMINIT_TRACE 342 }; 343 344 #ifdef CONFIG_DEBUG_MEMORY_INIT 345 346 extern int mminit_loglevel; 347 348 #define mminit_dprintk(level, prefix, fmt, arg...) \ 349 do { \ 350 if (level < mminit_loglevel) { \ 351 if (level <= MMINIT_WARNING) \ 352 printk(KERN_WARNING "mminit::" prefix " " fmt, ##arg); \ 353 else \ 354 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \ 355 } \ 356 } while (0) 357 358 extern void mminit_verify_pageflags_layout(void); 359 extern void mminit_verify_zonelist(void); 360 #else 361 362 static inline void mminit_dprintk(enum mminit_level level, 363 const char *prefix, const char *fmt, ...) 364 { 365 } 366 367 static inline void mminit_verify_pageflags_layout(void) 368 { 369 } 370 371 static inline void mminit_verify_zonelist(void) 372 { 373 } 374 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 375 376 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 377 #if defined(CONFIG_SPARSEMEM) 378 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 379 unsigned long *end_pfn); 380 #else 381 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 382 unsigned long *end_pfn) 383 { 384 } 385 #endif /* CONFIG_SPARSEMEM */ 386 387 #define ZONE_RECLAIM_NOSCAN -2 388 #define ZONE_RECLAIM_FULL -1 389 #define ZONE_RECLAIM_SOME 0 390 #define ZONE_RECLAIM_SUCCESS 1 391 392 extern int hwpoison_filter(struct page *p); 393 394 extern u32 hwpoison_filter_dev_major; 395 extern u32 hwpoison_filter_dev_minor; 396 extern u64 hwpoison_filter_flags_mask; 397 extern u64 hwpoison_filter_flags_value; 398 extern u64 hwpoison_filter_memcg; 399 extern u32 hwpoison_filter_enable; 400 401 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, 402 unsigned long, unsigned long, 403 unsigned long, unsigned long); 404 405 extern void set_pageblock_order(void); 406 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 407 struct list_head *page_list); 408 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 409 #define ALLOC_WMARK_MIN WMARK_MIN 410 #define ALLOC_WMARK_LOW WMARK_LOW 411 #define ALLOC_WMARK_HIGH WMARK_HIGH 412 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 413 414 /* Mask to get the watermark bits */ 415 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 416 417 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 418 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 419 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 420 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 421 #define ALLOC_FAIR 0x100 /* fair zone allocation */ 422 423 enum ttu_flags; 424 struct tlbflush_unmap_batch; 425 426 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 427 void try_to_unmap_flush(void); 428 void try_to_unmap_flush_dirty(void); 429 #else 430 static inline void try_to_unmap_flush(void) 431 { 432 } 433 static inline void try_to_unmap_flush_dirty(void) 434 { 435 } 436 437 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ 438 #endif /* __MM_INTERNAL_H */ 439