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/mm.h> 15 16 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, 17 unsigned long floor, unsigned long ceiling); 18 19 static inline void set_page_count(struct page *page, int v) 20 { 21 atomic_set(&page->_count, v); 22 } 23 24 /* 25 * Turn a non-refcounted page (->_count == 0) into refcounted with 26 * a count of one. 27 */ 28 static inline void set_page_refcounted(struct page *page) 29 { 30 VM_BUG_ON(PageTail(page)); 31 VM_BUG_ON(atomic_read(&page->_count)); 32 set_page_count(page, 1); 33 } 34 35 static inline void __put_page(struct page *page) 36 { 37 atomic_dec(&page->_count); 38 } 39 40 static inline void __get_page_tail_foll(struct page *page, 41 bool get_page_head) 42 { 43 /* 44 * If we're getting a tail page, the elevated page->_count is 45 * required only in the head page and we will elevate the head 46 * page->_count and tail page->_mapcount. 47 * 48 * We elevate page_tail->_mapcount for tail pages to force 49 * page_tail->_count to be zero at all times to avoid getting 50 * false positives from get_page_unless_zero() with 51 * speculative page access (like in 52 * page_cache_get_speculative()) on tail pages. 53 */ 54 VM_BUG_ON(atomic_read(&page->first_page->_count) <= 0); 55 VM_BUG_ON(atomic_read(&page->_count) != 0); 56 VM_BUG_ON(page_mapcount(page) < 0); 57 if (get_page_head) 58 atomic_inc(&page->first_page->_count); 59 atomic_inc(&page->_mapcount); 60 } 61 62 /* 63 * This is meant to be called as the FOLL_GET operation of 64 * follow_page() and it must be called while holding the proper PT 65 * lock while the pte (or pmd_trans_huge) is still mapping the page. 66 */ 67 static inline void get_page_foll(struct page *page) 68 { 69 if (unlikely(PageTail(page))) 70 /* 71 * This is safe only because 72 * __split_huge_page_refcount() can't run under 73 * get_page_foll() because we hold the proper PT lock. 74 */ 75 __get_page_tail_foll(page, true); 76 else { 77 /* 78 * Getting a normal page or the head of a compound page 79 * requires to already have an elevated page->_count. 80 */ 81 VM_BUG_ON(atomic_read(&page->_count) <= 0); 82 atomic_inc(&page->_count); 83 } 84 } 85 86 extern unsigned long highest_memmap_pfn; 87 88 /* 89 * in mm/vmscan.c: 90 */ 91 extern int isolate_lru_page(struct page *page); 92 extern void putback_lru_page(struct page *page); 93 94 /* 95 * in mm/rmap.c: 96 */ 97 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); 98 99 /* 100 * in mm/page_alloc.c 101 */ 102 extern void __free_pages_bootmem(struct page *page, unsigned int order); 103 extern void prep_compound_page(struct page *page, unsigned long order); 104 #ifdef CONFIG_MEMORY_FAILURE 105 extern bool is_free_buddy_page(struct page *page); 106 #endif 107 108 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 109 110 /* 111 * in mm/compaction.c 112 */ 113 /* 114 * compact_control is used to track pages being migrated and the free pages 115 * they are being migrated to during memory compaction. The free_pfn starts 116 * at the end of a zone and migrate_pfn begins at the start. Movable pages 117 * are moved to the end of a zone during a compaction run and the run 118 * completes when free_pfn <= migrate_pfn 119 */ 120 struct compact_control { 121 struct list_head freepages; /* List of free pages to migrate to */ 122 struct list_head migratepages; /* List of pages being migrated */ 123 unsigned long nr_freepages; /* Number of isolated free pages */ 124 unsigned long nr_migratepages; /* Number of pages to migrate */ 125 unsigned long free_pfn; /* isolate_freepages search base */ 126 unsigned long migrate_pfn; /* isolate_migratepages search base */ 127 bool sync; /* Synchronous migration */ 128 bool ignore_skip_hint; /* Scan blocks even if marked skip */ 129 bool finished_update_free; /* True when the zone cached pfns are 130 * no longer being updated 131 */ 132 bool finished_update_migrate; 133 134 int order; /* order a direct compactor needs */ 135 int migratetype; /* MOVABLE, RECLAIMABLE etc */ 136 struct zone *zone; 137 bool contended; /* True if a lock was contended */ 138 struct page **page; /* Page captured of requested size */ 139 }; 140 141 unsigned long 142 isolate_freepages_range(struct compact_control *cc, 143 unsigned long start_pfn, unsigned long end_pfn); 144 unsigned long 145 isolate_migratepages_range(struct zone *zone, struct compact_control *cc, 146 unsigned long low_pfn, unsigned long end_pfn, bool unevictable); 147 148 #endif 149 150 /* 151 * function for dealing with page's order in buddy system. 152 * zone->lock is already acquired when we use these. 153 * So, we don't need atomic page->flags operations here. 154 */ 155 static inline unsigned long page_order(struct page *page) 156 { 157 /* PageBuddy() must be checked by the caller */ 158 return page_private(page); 159 } 160 161 /* mm/util.c */ 162 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 163 struct vm_area_struct *prev, struct rb_node *rb_parent); 164 165 #ifdef CONFIG_MMU 166 extern long mlock_vma_pages_range(struct vm_area_struct *vma, 167 unsigned long start, unsigned long end); 168 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 169 unsigned long start, unsigned long end); 170 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 171 { 172 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 173 } 174 175 /* 176 * Called only in fault path, to determine if a new page is being 177 * mapped into a LOCKED vma. If it is, mark page as mlocked. 178 */ 179 static inline int mlocked_vma_newpage(struct vm_area_struct *vma, 180 struct page *page) 181 { 182 VM_BUG_ON(PageLRU(page)); 183 184 if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) 185 return 0; 186 187 if (!TestSetPageMlocked(page)) { 188 mod_zone_page_state(page_zone(page), NR_MLOCK, 189 hpage_nr_pages(page)); 190 count_vm_event(UNEVICTABLE_PGMLOCKED); 191 } 192 return 1; 193 } 194 195 /* 196 * must be called with vma's mmap_sem held for read or write, and page locked. 197 */ 198 extern void mlock_vma_page(struct page *page); 199 extern void munlock_vma_page(struct page *page); 200 201 /* 202 * Clear the page's PageMlocked(). This can be useful in a situation where 203 * we want to unconditionally remove a page from the pagecache -- e.g., 204 * on truncation or freeing. 205 * 206 * It is legal to call this function for any page, mlocked or not. 207 * If called for a page that is still mapped by mlocked vmas, all we do 208 * is revert to lazy LRU behaviour -- semantics are not broken. 209 */ 210 extern void clear_page_mlock(struct page *page); 211 212 /* 213 * mlock_migrate_page - called only from migrate_page_copy() to 214 * migrate the Mlocked page flag; update statistics. 215 */ 216 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 217 { 218 if (TestClearPageMlocked(page)) { 219 unsigned long flags; 220 221 local_irq_save(flags); 222 __dec_zone_page_state(page, NR_MLOCK); 223 SetPageMlocked(newpage); 224 __inc_zone_page_state(newpage, NR_MLOCK); 225 local_irq_restore(flags); 226 } 227 } 228 229 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 230 extern unsigned long vma_address(struct page *page, 231 struct vm_area_struct *vma); 232 #endif 233 #else /* !CONFIG_MMU */ 234 static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p) 235 { 236 return 0; 237 } 238 static inline void clear_page_mlock(struct page *page) { } 239 static inline void mlock_vma_page(struct page *page) { } 240 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 241 242 #endif /* !CONFIG_MMU */ 243 244 /* 245 * Return the mem_map entry representing the 'offset' subpage within 246 * the maximally aligned gigantic page 'base'. Handle any discontiguity 247 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 248 */ 249 static inline struct page *mem_map_offset(struct page *base, int offset) 250 { 251 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 252 return pfn_to_page(page_to_pfn(base) + offset); 253 return base + offset; 254 } 255 256 /* 257 * Iterator over all subpages within the maximally aligned gigantic 258 * page 'base'. Handle any discontiguity in the mem_map. 259 */ 260 static inline struct page *mem_map_next(struct page *iter, 261 struct page *base, int offset) 262 { 263 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 264 unsigned long pfn = page_to_pfn(base) + offset; 265 if (!pfn_valid(pfn)) 266 return NULL; 267 return pfn_to_page(pfn); 268 } 269 return iter + 1; 270 } 271 272 /* 273 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 274 * so all functions starting at paging_init should be marked __init 275 * in those cases. SPARSEMEM, however, allows for memory hotplug, 276 * and alloc_bootmem_node is not used. 277 */ 278 #ifdef CONFIG_SPARSEMEM 279 #define __paginginit __meminit 280 #else 281 #define __paginginit __init 282 #endif 283 284 /* Memory initialisation debug and verification */ 285 enum mminit_level { 286 MMINIT_WARNING, 287 MMINIT_VERIFY, 288 MMINIT_TRACE 289 }; 290 291 #ifdef CONFIG_DEBUG_MEMORY_INIT 292 293 extern int mminit_loglevel; 294 295 #define mminit_dprintk(level, prefix, fmt, arg...) \ 296 do { \ 297 if (level < mminit_loglevel) { \ 298 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \ 299 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \ 300 } \ 301 } while (0) 302 303 extern void mminit_verify_pageflags_layout(void); 304 extern void mminit_verify_page_links(struct page *page, 305 enum zone_type zone, unsigned long nid, unsigned long pfn); 306 extern void mminit_verify_zonelist(void); 307 308 #else 309 310 static inline void mminit_dprintk(enum mminit_level level, 311 const char *prefix, const char *fmt, ...) 312 { 313 } 314 315 static inline void mminit_verify_pageflags_layout(void) 316 { 317 } 318 319 static inline void mminit_verify_page_links(struct page *page, 320 enum zone_type zone, unsigned long nid, unsigned long pfn) 321 { 322 } 323 324 static inline void mminit_verify_zonelist(void) 325 { 326 } 327 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 328 329 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 330 #if defined(CONFIG_SPARSEMEM) 331 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 332 unsigned long *end_pfn); 333 #else 334 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 335 unsigned long *end_pfn) 336 { 337 } 338 #endif /* CONFIG_SPARSEMEM */ 339 340 #define ZONE_RECLAIM_NOSCAN -2 341 #define ZONE_RECLAIM_FULL -1 342 #define ZONE_RECLAIM_SOME 0 343 #define ZONE_RECLAIM_SUCCESS 1 344 345 extern int hwpoison_filter(struct page *p); 346 347 extern u32 hwpoison_filter_dev_major; 348 extern u32 hwpoison_filter_dev_minor; 349 extern u64 hwpoison_filter_flags_mask; 350 extern u64 hwpoison_filter_flags_value; 351 extern u64 hwpoison_filter_memcg; 352 extern u32 hwpoison_filter_enable; 353 354 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, 355 unsigned long, unsigned long, 356 unsigned long, unsigned long); 357 358 extern void set_pageblock_order(void); 359 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 360 struct list_head *page_list); 361 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 362 #define ALLOC_WMARK_MIN WMARK_MIN 363 #define ALLOC_WMARK_LOW WMARK_LOW 364 #define ALLOC_WMARK_HIGH WMARK_HIGH 365 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 366 367 /* Mask to get the watermark bits */ 368 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 369 370 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 371 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 372 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 373 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 374 375 #endif /* __MM_INTERNAL_H */ 376