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