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         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 */