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 17 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, 18 unsigned long floor, unsigned long ceiling); 19 20 static inline void set_page_count(struct page *page, int v) 21 { 22 atomic_set(&page->_count, v); 23 } 24 25 extern int __do_page_cache_readahead(struct address_space *mapping, 26 struct file *filp, pgoff_t offset, unsigned long nr_to_read, 27 unsigned long lookahead_size); 28 29 /* 30 * Submit IO for the read-ahead request in file_ra_state. 31 */ 32 static inline unsigned long ra_submit(struct file_ra_state *ra, 33 struct address_space *mapping, struct file *filp) 34 { 35 return __do_page_cache_readahead(mapping, filp, 36 ra->start, ra->size, ra->async_size); 37 } 38 39 /* 40 * Turn a non-refcounted page (->_count == 0) into refcounted with 41 * a count of one. 42 */ 43 static inline void set_page_refcounted(struct page *page) 44 { 45 VM_BUG_ON_PAGE(PageTail(page), page); 46 VM_BUG_ON_PAGE(atomic_read(&page->_count), page); 47 set_page_count(page, 1); 48 } 49 50 static inline void __get_page_tail_foll(struct page *page, 51 bool get_page_head) 52 { 53 /* 54 * If we're getting a tail page, the elevated page->_count is 55 * required only in the head page and we will elevate the head 56 * page->_count and tail page->_mapcount. 57 * 58 * We elevate page_tail->_mapcount for tail pages to force 59 * page_tail->_count to be zero at all times to avoid getting 60 * false positives from get_page_unless_zero() with 61 * speculative page access (like in 62 * page_cache_get_speculative()) on tail pages. 63 */ 64 VM_BUG_ON_PAGE(atomic_read(&page->first_page->_count) <= 0, page); 65 if (get_page_head) 66 atomic_inc(&page->first_page->_count); 67 get_huge_page_tail(page); 68 } 69 70 /* 71 * This is meant to be called as the FOLL_GET operation of 72 * follow_page() and it must be called while holding the proper PT 73 * lock while the pte (or pmd_trans_huge) is still mapping the page. 74 */ 75 static inline void get_page_foll(struct page *page) 76 { 77 if (unlikely(PageTail(page))) 78 /* 79 * This is safe only because 80 * __split_huge_page_refcount() can't run under 81 * get_page_foll() because we hold the proper PT lock. 82 */ 83 __get_page_tail_foll(page, true); 84 else { 85 /* 86 * Getting a normal page or the head of a compound page 87 * requires to already have an elevated page->_count. 88 */ 89 VM_BUG_ON_PAGE(atomic_read(&page->_count) <= 0, page); 90 atomic_inc(&page->_count); 91 } 92 } 93 94 extern unsigned long highest_memmap_pfn; 95 96 /* 97 * in mm/vmscan.c: 98 */ 99 extern int isolate_lru_page(struct page *page); 100 extern void putback_lru_page(struct page *page); 101 extern bool zone_reclaimable(struct zone *zone); 102 103 /* 104 * in mm/rmap.c: 105 */ 106 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 107 108 /* 109 * in mm/page_alloc.c 110 */ 111 112 /* 113 * Locate the struct page for both the matching buddy in our 114 * pair (buddy1) and the combined O(n+1) page they form (page). 115 * 116 * 1) Any buddy B1 will have an order O twin B2 which satisfies 117 * the following equation: 118 * B2 = B1 ^ (1 << O) 119 * For example, if the starting buddy (buddy2) is #8 its order 120 * 1 buddy is #10: 121 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 122 * 123 * 2) Any buddy B will have an order O+1 parent P which 124 * satisfies the following equation: 125 * P = B & ~(1 << O) 126 * 127 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 128 */ 129 static inline unsigned long 130 __find_buddy_index(unsigned long page_idx, unsigned int order) 131 { 132 return page_idx ^ (1 << order); 133 } 134 135 extern int __isolate_free_page(struct page *page, unsigned int order); 136 extern void __free_pages_bootmem(struct page *page, unsigned int order); 137 extern void prep_compound_page(struct page *page, unsigned long 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 enum migrate_mode mode; /* Async or sync migration mode */ 163 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 164 bool finished_update_free; /* True when the zone cached pfns are 165 * no longer being updated 166 */ 167 bool finished_update_migrate; 168 169 int order; /* order a direct compactor needs */ 170 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 171 struct zone *zone; 172 int contended; /* Signal need_sched() or lock 173 * contention detected during 174 * compaction 175 */ 176 }; 177 178 unsigned long 179 isolate_freepages_range(struct compact_control *cc, 180 unsigned long start_pfn, unsigned long end_pfn); 181 unsigned long 182 isolate_migratepages_range(struct compact_control *cc, 183 unsigned long low_pfn, unsigned long end_pfn); 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 long 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 * ACCESS_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) ACCESS_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 __mlock_vma_pages_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_page_copy() to 252 * migrate the Mlocked page flag; update statistics. 253 */ 254 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 255 { 256 if (TestClearPageMlocked(page)) { 257 unsigned long flags; 258 int nr_pages = hpage_nr_pages(page); 259 260 local_irq_save(flags); 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 local_irq_restore(flags); 265 } 266 } 267 268 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 269 270 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 271 extern unsigned long vma_address(struct page *page, 272 struct vm_area_struct *vma); 273 #endif 274 #else /* !CONFIG_MMU */ 275 static inline void clear_page_mlock(struct page *page) { } 276 static inline void mlock_vma_page(struct page *page) { } 277 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 278 279 #endif /* !CONFIG_MMU */ 280 281 /* 282 * Return the mem_map entry representing the 'offset' subpage within 283 * the maximally aligned gigantic page 'base'. Handle any discontiguity 284 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 285 */ 286 static inline struct page *mem_map_offset(struct page *base, int offset) 287 { 288 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 289 return nth_page(base, offset); 290 return base + offset; 291 } 292 293 /* 294 * Iterator over all subpages within the maximally aligned gigantic 295 * page 'base'. Handle any discontiguity in the mem_map. 296 */ 297 static inline struct page *mem_map_next(struct page *iter, 298 struct page *base, int offset) 299 { 300 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 301 unsigned long pfn = page_to_pfn(base) + offset; 302 if (!pfn_valid(pfn)) 303 return NULL; 304 return pfn_to_page(pfn); 305 } 306 return iter + 1; 307 } 308 309 /* 310 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 311 * so all functions starting at paging_init should be marked __init 312 * in those cases. SPARSEMEM, however, allows for memory hotplug, 313 * and alloc_bootmem_node is not used. 314 */ 315 #ifdef CONFIG_SPARSEMEM 316 #define __paginginit __meminit 317 #else 318 #define __paginginit __init 319 #endif 320 321 /* Memory initialisation debug and verification */ 322 enum mminit_level { 323 MMINIT_WARNING, 324 MMINIT_VERIFY, 325 MMINIT_TRACE 326 }; 327 328 #ifdef CONFIG_DEBUG_MEMORY_INIT 329 330 extern int mminit_loglevel; 331 332 #define mminit_dprintk(level, prefix, fmt, arg...) \ 333 do { \ 334 if (level < mminit_loglevel) { \ 335 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \ 336 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \ 337 } \ 338 } while (0) 339 340 extern void mminit_verify_pageflags_layout(void); 341 extern void mminit_verify_page_links(struct page *page, 342 enum zone_type zone, unsigned long nid, unsigned long pfn); 343 extern void mminit_verify_zonelist(void); 344 345 #else 346 347 static inline void mminit_dprintk(enum mminit_level level, 348 const char *prefix, const char *fmt, ...) 349 { 350 } 351 352 static inline void mminit_verify_pageflags_layout(void) 353 { 354 } 355 356 static inline void mminit_verify_page_links(struct page *page, 357 enum zone_type zone, unsigned long nid, unsigned long pfn) 358 { 359 } 360 361 static inline void mminit_verify_zonelist(void) 362 { 363 } 364 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 365 366 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 367 #if defined(CONFIG_SPARSEMEM) 368 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 369 unsigned long *end_pfn); 370 #else 371 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 372 unsigned long *end_pfn) 373 { 374 } 375 #endif /* CONFIG_SPARSEMEM */ 376 377 #define ZONE_RECLAIM_NOSCAN -2 378 #define ZONE_RECLAIM_FULL -1 379 #define ZONE_RECLAIM_SOME 0 380 #define ZONE_RECLAIM_SUCCESS 1 381 382 extern int hwpoison_filter(struct page *p); 383 384 extern u32 hwpoison_filter_dev_major; 385 extern u32 hwpoison_filter_dev_minor; 386 extern u64 hwpoison_filter_flags_mask; 387 extern u64 hwpoison_filter_flags_value; 388 extern u64 hwpoison_filter_memcg; 389 extern u32 hwpoison_filter_enable; 390 391 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, 392 unsigned long, unsigned long, 393 unsigned long, unsigned long); 394 395 extern void set_pageblock_order(void); 396 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 397 struct list_head *page_list); 398 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 399 #define ALLOC_WMARK_MIN WMARK_MIN 400 #define ALLOC_WMARK_LOW WMARK_LOW 401 #define ALLOC_WMARK_HIGH WMARK_HIGH 402 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 403 404 /* Mask to get the watermark bits */ 405 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 406 407 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 408 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 409 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 410 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 411 #define ALLOC_FAIR 0x100 /* fair zone allocation */ 412 413 #endif /* __MM_INTERNAL_H */ 414