mm/internal.h

   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);