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 migrate_pfn; /* isolate_migratepages search base */ 122 bool sync; /* Synchronous migration */ 123 124 int order; /* order a direct compactor needs */ 125 int migratetype; /* MOVABLE, RECLAIMABLE etc */ 126 struct zone *zone; 127 }; 128 129 unsigned long 130 isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn); 131 unsigned long 132 isolate_migratepages_range(struct zone *zone, struct compact_control *cc, 133 unsigned long low_pfn, unsigned long end_pfn); 134 135 #endif 136 137 /* 138 * function for dealing with page's order in buddy system. 139 * zone->lock is already acquired when we use these. 140 * So, we don't need atomic page->flags operations here. 141 */ 142 static inline unsigned long page_order(struct page *page) 143 { 144 /* PageBuddy() must be checked by the caller */ 145 return page_private(page); 146 } 147 148 /* mm/util.c */ 149 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 150 struct vm_area_struct *prev, struct rb_node *rb_parent); 151 152 #ifdef CONFIG_MMU 153 extern long mlock_vma_pages_range(struct vm_area_struct *vma, 154 unsigned long start, unsigned long end); 155 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 156 unsigned long start, unsigned long end); 157 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 158 { 159 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 160 } 161 162 /* 163 * Called only in fault path via page_evictable() for a new page 164 * to determine if it's being mapped into a LOCKED vma. 165 * If so, mark page as mlocked. 166 */ 167 static inline int mlocked_vma_newpage(struct vm_area_struct *vma, 168 struct page *page) 169 { 170 VM_BUG_ON(PageLRU(page)); 171 172 if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) 173 return 0; 174 175 if (!TestSetPageMlocked(page)) { 176 inc_zone_page_state(page, NR_MLOCK); 177 count_vm_event(UNEVICTABLE_PGMLOCKED); 178 } 179 return 1; 180 } 181 182 /* 183 * must be called with vma's mmap_sem held for read or write, and page locked. 184 */ 185 extern void mlock_vma_page(struct page *page); 186 extern void munlock_vma_page(struct page *page); 187 188 /* 189 * Clear the page's PageMlocked(). This can be useful in a situation where 190 * we want to unconditionally remove a page from the pagecache -- e.g., 191 * on truncation or freeing. 192 * 193 * It is legal to call this function for any page, mlocked or not. 194 * If called for a page that is still mapped by mlocked vmas, all we do 195 * is revert to lazy LRU behaviour -- semantics are not broken. 196 */ 197 extern void __clear_page_mlock(struct page *page); 198 static inline void clear_page_mlock(struct page *page) 199 { 200 if (unlikely(TestClearPageMlocked(page))) 201 __clear_page_mlock(page); 202 } 203 204 /* 205 * mlock_migrate_page - called only from migrate_page_copy() to 206 * migrate the Mlocked page flag; update statistics. 207 */ 208 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 209 { 210 if (TestClearPageMlocked(page)) { 211 unsigned long flags; 212 213 local_irq_save(flags); 214 __dec_zone_page_state(page, NR_MLOCK); 215 SetPageMlocked(newpage); 216 __inc_zone_page_state(newpage, NR_MLOCK); 217 local_irq_restore(flags); 218 } 219 } 220 221 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 222 extern unsigned long vma_address(struct page *page, 223 struct vm_area_struct *vma); 224 #endif 225 #else /* !CONFIG_MMU */ 226 static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p) 227 { 228 return 0; 229 } 230 static inline void clear_page_mlock(struct page *page) { } 231 static inline void mlock_vma_page(struct page *page) { } 232 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 233 234 #endif /* !CONFIG_MMU */ 235 236 /* 237 * Return the mem_map entry representing the 'offset' subpage within 238 * the maximally aligned gigantic page 'base'. Handle any discontiguity 239 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 240 */ 241 static inline struct page *mem_map_offset(struct page *base, int offset) 242 { 243 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 244 return pfn_to_page(page_to_pfn(base) + offset); 245 return base + offset; 246 } 247 248 /* 249 * Iterator over all subpages within the maximally aligned gigantic 250 * page 'base'. Handle any discontiguity in the mem_map. 251 */ 252 static inline struct page *mem_map_next(struct page *iter, 253 struct page *base, int offset) 254 { 255 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 256 unsigned long pfn = page_to_pfn(base) + offset; 257 if (!pfn_valid(pfn)) 258 return NULL; 259 return pfn_to_page(pfn); 260 } 261 return iter + 1; 262 } 263 264 /* 265 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 266 * so all functions starting at paging_init should be marked __init 267 * in those cases. SPARSEMEM, however, allows for memory hotplug, 268 * and alloc_bootmem_node is not used. 269 */ 270 #ifdef CONFIG_SPARSEMEM 271 #define __paginginit __meminit 272 #else 273 #define __paginginit __init 274 #endif 275 276 /* Memory initialisation debug and verification */ 277 enum mminit_level { 278 MMINIT_WARNING, 279 MMINIT_VERIFY, 280 MMINIT_TRACE 281 }; 282 283 #ifdef CONFIG_DEBUG_MEMORY_INIT 284 285 extern int mminit_loglevel; 286 287 #define mminit_dprintk(level, prefix, fmt, arg...) \ 288 do { \ 289 if (level < mminit_loglevel) { \ 290 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \ 291 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \ 292 } \ 293 } while (0) 294 295 extern void mminit_verify_pageflags_layout(void); 296 extern void mminit_verify_page_links(struct page *page, 297 enum zone_type zone, unsigned long nid, unsigned long pfn); 298 extern void mminit_verify_zonelist(void); 299 300 #else 301 302 static inline void mminit_dprintk(enum mminit_level level, 303 const char *prefix, const char *fmt, ...) 304 { 305 } 306 307 static inline void mminit_verify_pageflags_layout(void) 308 { 309 } 310 311 static inline void mminit_verify_page_links(struct page *page, 312 enum zone_type zone, unsigned long nid, unsigned long pfn) 313 { 314 } 315 316 static inline void mminit_verify_zonelist(void) 317 { 318 } 319 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 320 321 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 322 #if defined(CONFIG_SPARSEMEM) 323 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 324 unsigned long *end_pfn); 325 #else 326 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 327 unsigned long *end_pfn) 328 { 329 } 330 #endif /* CONFIG_SPARSEMEM */ 331 332 #define ZONE_RECLAIM_NOSCAN -2 333 #define ZONE_RECLAIM_FULL -1 334 #define ZONE_RECLAIM_SOME 0 335 #define ZONE_RECLAIM_SUCCESS 1 336 #endif 337 338 extern int hwpoison_filter(struct page *p); 339 340 extern u32 hwpoison_filter_dev_major; 341 extern u32 hwpoison_filter_dev_minor; 342 extern u64 hwpoison_filter_flags_mask; 343 extern u64 hwpoison_filter_flags_value; 344 extern u64 hwpoison_filter_memcg; 345 extern u32 hwpoison_filter_enable; 346 347 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, 348 unsigned long, unsigned long, 349 unsigned long, unsigned long); 350