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/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 start_free_pfn; /* where we started the search */ 122 unsigned long migrate_pfn; /* isolate_migratepages search base */ 123 bool sync; /* Synchronous migration */ 124 bool wrapped; /* Order > 0 compactions are 125 incremental, once free_pfn 126 and migrate_pfn meet, we restart 127 from the top of the zone; 128 remember we wrapped around. */ 129 130 int order; /* order a direct compactor needs */ 131 int migratetype; /* MOVABLE, RECLAIMABLE etc */ 132 struct zone *zone; 133 bool *contended; /* True if a lock was contended */ 134 }; 135 136 unsigned long 137 isolate_freepages_range(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); 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); 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 via page_evictable() for a new page 171 * to determine if it's being mapped into a LOCKED vma. 172 * If so, mark page as mlocked. 173 */ 174 static inline int mlocked_vma_newpage(struct vm_area_struct *vma, 175 struct page *page) 176 { 177 VM_BUG_ON(PageLRU(page)); 178 179 if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) 180 return 0; 181 182 if (!TestSetPageMlocked(page)) { 183 inc_zone_page_state(page, NR_MLOCK); 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 void 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 static inline void clear_page_mlock(struct page *page) 206 { 207 if (unlikely(TestClearPageMlocked(page))) 208 __clear_page_mlock(page); 209 } 210 211 /* 212 * mlock_migrate_page - called only from migrate_page_copy() to 213 * migrate the Mlocked page flag; update statistics. 214 */ 215 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 216 { 217 if (TestClearPageMlocked(page)) { 218 unsigned long flags; 219 220 local_irq_save(flags); 221 __dec_zone_page_state(page, NR_MLOCK); 222 SetPageMlocked(newpage); 223 __inc_zone_page_state(newpage, NR_MLOCK); 224 local_irq_restore(flags); 225 } 226 } 227 228 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 229 extern unsigned long vma_address(struct page *page, 230 struct vm_area_struct *vma); 231 #endif 232 #else /* !CONFIG_MMU */ 233 static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p) 234 { 235 return 0; 236 } 237 static inline void clear_page_mlock(struct page *page) { } 238 static inline void mlock_vma_page(struct page *page) { } 239 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 240 241 #endif /* !CONFIG_MMU */ 242 243 /* 244 * Return the mem_map entry representing the 'offset' subpage within 245 * the maximally aligned gigantic page 'base'. Handle any discontiguity 246 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 247 */ 248 static inline struct page *mem_map_offset(struct page *base, int offset) 249 { 250 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 251 return pfn_to_page(page_to_pfn(base) + offset); 252 return base + offset; 253 } 254 255 /* 256 * Iterator over all subpages within the maximally aligned gigantic 257 * page 'base'. Handle any discontiguity in the mem_map. 258 */ 259 static inline struct page *mem_map_next(struct page *iter, 260 struct page *base, int offset) 261 { 262 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 263 unsigned long pfn = page_to_pfn(base) + offset; 264 if (!pfn_valid(pfn)) 265 return NULL; 266 return pfn_to_page(pfn); 267 } 268 return iter + 1; 269 } 270 271 /* 272 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 273 * so all functions starting at paging_init should be marked __init 274 * in those cases. SPARSEMEM, however, allows for memory hotplug, 275 * and alloc_bootmem_node is not used. 276 */ 277 #ifdef CONFIG_SPARSEMEM 278 #define __paginginit __meminit 279 #else 280 #define __paginginit __init 281 #endif 282 283 /* Memory initialisation debug and verification */ 284 enum mminit_level { 285 MMINIT_WARNING, 286 MMINIT_VERIFY, 287 MMINIT_TRACE 288 }; 289 290 #ifdef CONFIG_DEBUG_MEMORY_INIT 291 292 extern int mminit_loglevel; 293 294 #define mminit_dprintk(level, prefix, fmt, arg...) \ 295 do { \ 296 if (level < mminit_loglevel) { \ 297 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \ 298 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \ 299 } \ 300 } while (0) 301 302 extern void mminit_verify_pageflags_layout(void); 303 extern void mminit_verify_page_links(struct page *page, 304 enum zone_type zone, unsigned long nid, unsigned long pfn); 305 extern void mminit_verify_zonelist(void); 306 307 #else 308 309 static inline void mminit_dprintk(enum mminit_level level, 310 const char *prefix, const char *fmt, ...) 311 { 312 } 313 314 static inline void mminit_verify_pageflags_layout(void) 315 { 316 } 317 318 static inline void mminit_verify_page_links(struct page *page, 319 enum zone_type zone, unsigned long nid, unsigned long pfn) 320 { 321 } 322 323 static inline void mminit_verify_zonelist(void) 324 { 325 } 326 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 327 328 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 329 #if defined(CONFIG_SPARSEMEM) 330 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 331 unsigned long *end_pfn); 332 #else 333 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 334 unsigned long *end_pfn) 335 { 336 } 337 #endif /* CONFIG_SPARSEMEM */ 338 339 #define ZONE_RECLAIM_NOSCAN -2 340 #define ZONE_RECLAIM_FULL -1 341 #define ZONE_RECLAIM_SOME 0 342 #define ZONE_RECLAIM_SUCCESS 1 343 #endif 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