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 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 struct page **page; /* Page captured of requested size */ 134 }; 135 136 unsigned long 137 isolate_freepages_range(struct compact_control *cc, 138 unsigned long start_pfn, unsigned long end_pfn); 139 unsigned long 140 isolate_migratepages_range(struct zone *zone, struct compact_control *cc, 141 unsigned long low_pfn, unsigned long end_pfn, bool unevictable); 142 143 #endif 144 145 /* 146 * function for dealing with page's order in buddy system. 147 * zone->lock is already acquired when we use these. 148 * So, we don't need atomic page->flags operations here. 149 */ 150 static inline unsigned long page_order(struct page *page) 151 { 152 /* PageBuddy() must be checked by the caller */ 153 return page_private(page); 154 } 155 156 /* mm/util.c */ 157 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, 158 struct vm_area_struct *prev, struct rb_node *rb_parent); 159 160 #ifdef CONFIG_MMU 161 extern long mlock_vma_pages_range(struct vm_area_struct *vma, 162 unsigned long start, unsigned long end); 163 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 164 unsigned long start, unsigned long end); 165 static inline void munlock_vma_pages_all(struct vm_area_struct *vma) 166 { 167 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); 168 } 169 170 /* 171 * Called only in fault path, to determine if a new page is being 172 * mapped into a LOCKED vma. If it is, 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 mod_zone_page_state(page_zone(page), NR_MLOCK, 184 hpage_nr_pages(page)); 185 count_vm_event(UNEVICTABLE_PGMLOCKED); 186 } 187 return 1; 188 } 189 190 /* 191 * must be called with vma's mmap_sem held for read or write, and page locked. 192 */ 193 extern void mlock_vma_page(struct page *page); 194 extern void munlock_vma_page(struct page *page); 195 196 /* 197 * Clear the page's PageMlocked(). This can be useful in a situation where 198 * we want to unconditionally remove a page from the pagecache -- e.g., 199 * on truncation or freeing. 200 * 201 * It is legal to call this function for any page, mlocked or not. 202 * If called for a page that is still mapped by mlocked vmas, all we do 203 * is revert to lazy LRU behaviour -- semantics are not broken. 204 */ 205 extern void clear_page_mlock(struct page *page); 206 207 /* 208 * mlock_migrate_page - called only from migrate_page_copy() to 209 * migrate the Mlocked page flag; update statistics. 210 */ 211 static inline void mlock_migrate_page(struct page *newpage, struct page *page) 212 { 213 if (TestClearPageMlocked(page)) { 214 unsigned long flags; 215 216 local_irq_save(flags); 217 __dec_zone_page_state(page, NR_MLOCK); 218 SetPageMlocked(newpage); 219 __inc_zone_page_state(newpage, NR_MLOCK); 220 local_irq_restore(flags); 221 } 222 } 223 224 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 225 extern unsigned long vma_address(struct page *page, 226 struct vm_area_struct *vma); 227 #endif 228 #else /* !CONFIG_MMU */ 229 static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p) 230 { 231 return 0; 232 } 233 static inline void clear_page_mlock(struct page *page) { } 234 static inline void mlock_vma_page(struct page *page) { } 235 static inline void mlock_migrate_page(struct page *new, struct page *old) { } 236 237 #endif /* !CONFIG_MMU */ 238 239 /* 240 * Return the mem_map entry representing the 'offset' subpage within 241 * the maximally aligned gigantic page 'base'. Handle any discontiguity 242 * in the mem_map at MAX_ORDER_NR_PAGES boundaries. 243 */ 244 static inline struct page *mem_map_offset(struct page *base, int offset) 245 { 246 if (unlikely(offset >= MAX_ORDER_NR_PAGES)) 247 return pfn_to_page(page_to_pfn(base) + offset); 248 return base + offset; 249 } 250 251 /* 252 * Iterator over all subpages within the maximally aligned gigantic 253 * page 'base'. Handle any discontiguity in the mem_map. 254 */ 255 static inline struct page *mem_map_next(struct page *iter, 256 struct page *base, int offset) 257 { 258 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 259 unsigned long pfn = page_to_pfn(base) + offset; 260 if (!pfn_valid(pfn)) 261 return NULL; 262 return pfn_to_page(pfn); 263 } 264 return iter + 1; 265 } 266 267 /* 268 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 269 * so all functions starting at paging_init should be marked __init 270 * in those cases. SPARSEMEM, however, allows for memory hotplug, 271 * and alloc_bootmem_node is not used. 272 */ 273 #ifdef CONFIG_SPARSEMEM 274 #define __paginginit __meminit 275 #else 276 #define __paginginit __init 277 #endif 278 279 /* Memory initialisation debug and verification */ 280 enum mminit_level { 281 MMINIT_WARNING, 282 MMINIT_VERIFY, 283 MMINIT_TRACE 284 }; 285 286 #ifdef CONFIG_DEBUG_MEMORY_INIT 287 288 extern int mminit_loglevel; 289 290 #define mminit_dprintk(level, prefix, fmt, arg...) \ 291 do { \ 292 if (level < mminit_loglevel) { \ 293 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \ 294 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \ 295 } \ 296 } while (0) 297 298 extern void mminit_verify_pageflags_layout(void); 299 extern void mminit_verify_page_links(struct page *page, 300 enum zone_type zone, unsigned long nid, unsigned long pfn); 301 extern void mminit_verify_zonelist(void); 302 303 #else 304 305 static inline void mminit_dprintk(enum mminit_level level, 306 const char *prefix, const char *fmt, ...) 307 { 308 } 309 310 static inline void mminit_verify_pageflags_layout(void) 311 { 312 } 313 314 static inline void mminit_verify_page_links(struct page *page, 315 enum zone_type zone, unsigned long nid, unsigned long pfn) 316 { 317 } 318 319 static inline void mminit_verify_zonelist(void) 320 { 321 } 322 #endif /* CONFIG_DEBUG_MEMORY_INIT */ 323 324 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */ 325 #if defined(CONFIG_SPARSEMEM) 326 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 327 unsigned long *end_pfn); 328 #else 329 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn, 330 unsigned long *end_pfn) 331 { 332 } 333 #endif /* CONFIG_SPARSEMEM */ 334 335 #define ZONE_RECLAIM_NOSCAN -2 336 #define ZONE_RECLAIM_FULL -1 337 #define ZONE_RECLAIM_SOME 0 338 #define ZONE_RECLAIM_SUCCESS 1 339 340 extern int hwpoison_filter(struct page *p); 341 342 extern u32 hwpoison_filter_dev_major; 343 extern u32 hwpoison_filter_dev_minor; 344 extern u64 hwpoison_filter_flags_mask; 345 extern u64 hwpoison_filter_flags_value; 346 extern u64 hwpoison_filter_memcg; 347 extern u32 hwpoison_filter_enable; 348 349 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long, 350 unsigned long, unsigned long, 351 unsigned long, unsigned long); 352 353 extern void set_pageblock_order(void); 354 unsigned long reclaim_clean_pages_from_list(struct zone *zone, 355 struct list_head *page_list); 356 /* The ALLOC_WMARK bits are used as an index to zone->watermark */ 357 #define ALLOC_WMARK_MIN WMARK_MIN 358 #define ALLOC_WMARK_LOW WMARK_LOW 359 #define ALLOC_WMARK_HIGH WMARK_HIGH 360 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 361 362 /* Mask to get the watermark bits */ 363 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 364 365 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 366 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 367 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 368 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ 369 370 #endif /* __MM_INTERNAL_H */ 371