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 }; 134 135 unsigned long 136 isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn); 137 unsigned long 138 isolate_migratepages_range(struct zone *zone, struct compact_control *cc, 139 unsigned long low_pfn, unsigned long end_pfn); 140 141 #endif 142 143 /* 144 * function for dealing with page's order in buddy system. 145 * zone->lock is already acquired when we use these. 146 * So, we don't need atomic page->flags operations here. 147 */ 148 static inline unsigned long page_order(struct page *page) 149 { 150 /* PageBuddy() must be checked by the caller */ 151 return page_private(page); 152 } 153 154 /* mm/util.c */ 155 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 156 struct vm_area_struct *prev, struct rb_node *rb_parent); 157 158 #ifdef CONFIG_MMU 159 extern long mlock_vma_pages_range(struct vm_area_struct *vma, 160 unsigned long start, unsigned long end); 161 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 162 unsigned long start, unsigned long end); 163 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 164 { 165 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 166 } 167 168 /* 169 * Called only in fault path via page_evictable() for a new page 170 * to determine if it's being mapped into a LOCKED vma. 171 * If so, 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 inc_zone_page_state(page, NR_MLOCK); 183 count_vm_event(UNEVICTABLE_PGMLOCKED); 184 } 185 return 1; 186 } 187 188 /* 189 * must be called with vma's mmap_sem held for read or write, and page locked. 190 */ 191 extern void mlock_vma_page(struct page *page); 192 extern void munlock_vma_page(struct page *page); 193 194 /* 195 * Clear the page's PageMlocked(). This can be useful in a situation where 196 * we want to unconditionally remove a page from the pagecache -- e.g., 197 * on truncation or freeing. 198 * 199 * It is legal to call this function for any page, mlocked or not. 200 * If called for a page that is still mapped by mlocked vmas, all we do 201 * is revert to lazy LRU behaviour -- semantics are not broken. 202 */ 203 extern void __clear_page_mlock(struct page *page); 204 static inline void clear_page_mlock(struct page *page) 205 { 206 if (unlikely(TestClearPageMlocked(page))) 207 __clear_page_mlock(page); 208 } 209 210 /* 211 * mlock_migrate_page - called only from migrate_page_copy() to 212 * migrate the Mlocked page flag; update statistics. 213 */ 214 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 215 { 216 if (TestClearPageMlocked(page)) { 217 unsigned long flags; 218 219 local_irq_save(flags); 220 __dec_zone_page_state(page, NR_MLOCK); 221 SetPageMlocked(newpage); 222 __inc_zone_page_state(newpage, NR_MLOCK); 223 local_irq_restore(flags); 224 } 225 } 226 227 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 228 extern unsigned long vma_address(struct page *page, 229 struct vm_area_struct *vma); 230 #endif 231 #else /* !CONFIG_MMU */ 232 static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p) 233 { 234 return 0; 235 } 236 static inline void clear_page_mlock(struct page *page) { } 237 static inline void mlock_vma_page(struct page *page) { } 238 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 239 240 #endif /* !CONFIG_MMU */ 241 242 /* 243 * Return the mem_map entry representing the 'offset' subpage within 244 * the maximally aligned gigantic page 'base'. Handle any discontiguity 245 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 246 */ 247 static inline struct page *mem_map_offset(struct page *base, int offset) 248 { 249 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 250 return pfn_to_page(page_to_pfn(base) + offset); 251 return base + offset; 252 } 253 254 /* 255 * Iterator over all subpages within the maximally aligned gigantic 256 * page 'base'. Handle any discontiguity in the mem_map. 257 */ 258 static inline struct page *mem_map_next(struct page *iter, 259 struct page *base, int offset) 260 { 261 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 262 unsigned long pfn = page_to_pfn(base) + offset; 263 if (!pfn_valid(pfn)) 264 return NULL; 265 return pfn_to_page(pfn); 266 } 267 return iter + 1; 268 } 269 270 /* 271 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 272 * so all functions starting at paging_init should be marked __init 273 * in those cases. SPARSEMEM, however, allows for memory hotplug, 274 * and alloc_bootmem_node is not used. 275 */ 276 #ifdef CONFIG_SPARSEMEM 277 #define __paginginit __meminit 278 #else 279 #define __paginginit __init 280 #endif 281 282 /* Memory initialisation debug and verification */ 283 enum mminit_level { 284 MMINIT_WARNING, 285 MMINIT_VERIFY, 286 MMINIT_TRACE 287 }; 288 289 #ifdef CONFIG_DEBUG_MEMORY_INIT 290 291 extern int mminit_loglevel; 292 293 #define mminit_dprintk(level, prefix, fmt, arg...) \ 294 do { \ 295 if (level < mminit_loglevel) { \ 296 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \ 297 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \ 298 } \ 299 } while (0) 300 301 extern void mminit_verify_pageflags_layout(void); 302 extern void mminit_verify_page_links(struct page *page, 303 enum zone_type zone, unsigned long nid, unsigned long pfn); 304 extern void mminit_verify_zonelist(void); 305 306 #else 307 308 static inline void mminit_dprintk(enum mminit_level level, 309 const char *prefix, const char *fmt, ...) 310 { 311 } 312 313 static inline void mminit_verify_pageflags_layout(void) 314 { 315 } 316 317 static inline void mminit_verify_page_links(struct page *page, 318 enum zone_type zone, unsigned long nid, unsigned long pfn) 319 { 320 } 321 322 static inline void mminit_verify_zonelist(void) 323 { 324 } 325 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 326 327 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 328 #if defined(CONFIG_SPARSEMEM) 329 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 330 unsigned long *end_pfn); 331 #else 332 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 333 unsigned long *end_pfn) 334 { 335 } 336 #endif /* CONFIG_SPARSEMEM */ 337 338 #define ZONE_RECLAIM_NOSCAN -2 339 #define ZONE_RECLAIM_FULL -1 340 #define ZONE_RECLAIM_SOME 0 341 #define ZONE_RECLAIM_SUCCESS 1 342 #endif 343 344 extern int hwpoison_filter(struct page *p); 345 346 extern u32 hwpoison_filter_dev_major; 347 extern u32 hwpoison_filter_dev_minor; 348 extern u64 hwpoison_filter_flags_mask; 349 extern u64 hwpoison_filter_flags_value; 350 extern u64 hwpoison_filter_memcg; 351 extern u32 hwpoison_filter_enable; 352 353 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, 354 unsigned long, unsigned long, 355 unsigned long, unsigned long); 356 357 extern void set_pageblock_order(void); 358