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 extern void __free_pages_bootmem(struct page *page, unsigned int order); 112 extern void prep_compound_page(struct page *page, unsigned long order); 113 #ifdef CONFIG_MEMORY_FAILURE 114 extern bool is_free_buddy_page(struct page *page); 115 #endif 116 extern int user_min_free_kbytes; 117 118 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 119 120 /* 121 * in mm/compaction.c 122 */ 123 /* 124 * compact_control is used to track pages being migrated and the free pages 125 * they are being migrated to during memory compaction. The free_pfn starts 126 * at the end of a zone and migrate_pfn begins at the start. Movable pages 127 * are moved to the end of a zone during a compaction run and the run 128 * completes when free_pfn <= migrate_pfn 129 */ 130 struct compact_control { 131 struct list_head freepages; /* List of free pages to migrate to */ 132 struct list_head migratepages; /* List of pages being migrated */ 133 unsigned long nr_freepages; /* Number of isolated free pages */ 134 unsigned long nr_migratepages; /* Number of pages to migrate */ 135 unsigned long free_pfn; /* isolate_freepages search base */ 136 unsigned long migrate_pfn; /* isolate_migratepages search base */ 137 enum migrate_mode mode; /* Async or sync migration mode */ 138 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 139 bool finished_update_free; /* True when the zone cached pfns are 140 * no longer being updated 141 */ 142 bool finished_update_migrate; 143 144 int order; /* order a direct compactor needs */ 145 const gfp_t gfp_mask; /* gfp mask of a direct compactor */ 146 struct zone *zone; 147 int contended; /* Signal need_sched() or lock 148 * contention detected during 149 * compaction 150 */ 151 }; 152 153 unsigned long 154 isolate_freepages_range(struct compact_control *cc, 155 unsigned long start_pfn, unsigned long end_pfn); 156 unsigned long 157 isolate_migratepages_range(struct compact_control *cc, 158 unsigned long low_pfn, unsigned long end_pfn); 159 160 #endif 161 162 /* 163 * This function returns the order of a free page in the buddy system. In 164 * general, page_zone(page)->lock must be held by the caller to prevent the 165 * page from being allocated in parallel and returning garbage as the order. 166 * If a caller does not hold page_zone(page)->lock, it must guarantee that the 167 * page cannot be allocated or merged in parallel. Alternatively, it must 168 * handle invalid values gracefully, and use page_order_unsafe() below. 169 */ 170 static inline unsigned long page_order(struct page *page) 171 { 172 /* PageBuddy() must be checked by the caller */ 173 return page_private(page); 174 } 175 176 /* 177 * Like page_order(), but for callers who cannot afford to hold the zone lock. 178 * PageBuddy() should be checked first by the caller to minimize race window, 179 * and invalid values must be handled gracefully. 180 * 181 * ACCESS_ONCE is used so that if the caller assigns the result into a local 182 * variable and e.g. tests it for valid range before using, the compiler cannot 183 * decide to remove the variable and inline the page_private(page) multiple 184 * times, potentially observing different values in the tests and the actual 185 * use of the result. 186 */ 187 #define page_order_unsafe(page) ACCESS_ONCE(page_private(page)) 188 189 static inline bool is_cow_mapping(vm_flags_t flags) 190 { 191 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 192 } 193 194 /* mm/util.c */ 195 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 196 struct vm_area_struct *prev, struct rb_node *rb_parent); 197 198 #ifdef CONFIG_MMU 199 extern long __mlock_vma_pages_range(struct vm_area_struct *vma, 200 unsigned long start, unsigned long end, int *nonblocking); 201 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 202 unsigned long start, unsigned long end); 203 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 204 { 205 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 206 } 207 208 /* 209 * must be called with vma's mmap_sem held for read or write, and page locked. 210 */ 211 extern void mlock_vma_page(struct page *page); 212 extern unsigned int munlock_vma_page(struct page *page); 213 214 /* 215 * Clear the page's PageMlocked(). This can be useful in a situation where 216 * we want to unconditionally remove a page from the pagecache -- e.g., 217 * on truncation or freeing. 218 * 219 * It is legal to call this function for any page, mlocked or not. 220 * If called for a page that is still mapped by mlocked vmas, all we do 221 * is revert to lazy LRU behaviour -- semantics are not broken. 222 */ 223 extern void clear_page_mlock(struct page *page); 224 225 /* 226 * mlock_migrate_page - called only from migrate_page_copy() to 227 * migrate the Mlocked page flag; update statistics. 228 */ 229 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 230 { 231 if (TestClearPageMlocked(page)) { 232 unsigned long flags; 233 int nr_pages = hpage_nr_pages(page); 234 235 local_irq_save(flags); 236 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); 237 SetPageMlocked(newpage); 238 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages); 239 local_irq_restore(flags); 240 } 241 } 242 243 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); 244 245 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 246 extern unsigned long vma_address(struct page *page, 247 struct vm_area_struct *vma); 248 #endif 249 #else /* !CONFIG_MMU */ 250 static inline void clear_page_mlock(struct page *page) { } 251 static inline void mlock_vma_page(struct page *page) { } 252 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 253 254 #endif /* !CONFIG_MMU */ 255 256 /* 257 * Return the mem_map entry representing the 'offset' subpage within 258 * the maximally aligned gigantic page 'base'. Handle any discontiguity 259 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 260 */ 261 static inline struct page *mem_map_offset(struct page *base, int offset) 262 { 263 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 264 return nth_page(base, offset); 265 return base + offset; 266 } 267 268 /* 269 * Iterator over all subpages within the maximally aligned gigantic 270 * page 'base'. Handle any discontiguity in the mem_map. 271 */ 272 static inline struct page *mem_map_next(struct page *iter, 273 struct page *base, int offset) 274 { 275 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 276 unsigned long pfn = page_to_pfn(base) + offset; 277 if (!pfn_valid(pfn)) 278 return NULL; 279 return pfn_to_page(pfn); 280 } 281 return iter + 1; 282 } 283 284 /* 285 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 286 * so all functions starting at paging_init should be marked __init 287 * in those cases. SPARSEMEM, however, allows for memory hotplug, 288 * and alloc_bootmem_node is not used. 289 */ 290 #ifdef CONFIG_SPARSEMEM 291 #define __paginginit __meminit 292 #else 293 #define __paginginit __init 294 #endif 295 296 /* Memory initialisation debug and verification */ 297 enum mminit_level { 298 MMINIT_WARNING, 299 MMINIT_VERIFY, 300 MMINIT_TRACE 301 }; 302 303 #ifdef CONFIG_DEBUG_MEMORY_INIT 304 305 extern int mminit_loglevel; 306 307 #define mminit_dprintk(level, prefix, fmt, arg...) \ 308 do { \ 309 if (level < mminit_loglevel) { \ 310 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \ 311 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \ 312 } \ 313 } while (0) 314 315 extern void mminit_verify_pageflags_layout(void); 316 extern void mminit_verify_page_links(struct page *page, 317 enum zone_type zone, unsigned long nid, unsigned long pfn); 318 extern void mminit_verify_zonelist(void); 319 320 #else 321 322 static inline void mminit_dprintk(enum mminit_level level, 323 const char *prefix, const char *fmt, ...) 324 { 325 } 326 327 static inline void mminit_verify_pageflags_layout(void) 328 { 329 } 330 331 static inline void mminit_verify_page_links(struct page *page, 332 enum zone_type zone, unsigned long nid, unsigned long pfn) 333 { 334 } 335 336 static inline void mminit_verify_zonelist(void) 337 { 338 } 339 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 340 341 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 342 #if defined(CONFIG_SPARSEMEM) 343 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 344 unsigned long *end_pfn); 345 #else 346 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 347 unsigned long *end_pfn) 348 { 349 } 350 #endif /* CONFIG_SPARSEMEM */ 351 352 #define ZONE_RECLAIM_NOSCAN -2 353 #define ZONE_RECLAIM_FULL -1 354 #define ZONE_RECLAIM_SOME 0 355 #define ZONE_RECLAIM_SUCCESS 1 356 357 extern int hwpoison_filter(struct page *p); 358 359 extern u32 hwpoison_filter_dev_major; 360 extern u32 hwpoison_filter_dev_minor; 361 extern u64 hwpoison_filter_flags_mask; 362 extern u64 hwpoison_filter_flags_value; 363 extern u64 hwpoison_filter_memcg; 364 extern u32 hwpoison_filter_enable; 365 366 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, 367 unsigned long, unsigned long, 368 unsigned long, unsigned long); 369 370 extern void set_pageblock_order(void); 371 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 372 struct list_head *page_list); 373 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 374 #define ALLOC_WMARK_MIN WMARK_MIN 375 #define ALLOC_WMARK_LOW WMARK_LOW 376 #define ALLOC_WMARK_HIGH WMARK_HIGH 377 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 378 379 /* Mask to get the watermark bits */ 380 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 381 382 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 383 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 384 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 385 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 386 #define ALLOC_FAIR 0x100 /* fair zone allocation */ 387 388 #endif /* __MM_INTERNAL_H */ 389