release/src-rt-6.x.4708/linux/linux-2.6.36/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 extern unsigned long highest_memmap_pfn;
  41
  42 /*
  43  * in mm/vmscan.c:
  44  */
  45 extern int isolate_lru_page(struct page *page);
  46 extern void putback_lru_page(struct page *page);
  47
  48 /*
  49  * in mm/page_alloc.c
  50  */
  51 extern void __free_pages_bootmem(struct page *page, unsigned int order);
  52 extern void prep_compound_page(struct page *page, unsigned long order);
  53 #ifdef CONFIG_MEMORY_FAILURE
  54 extern bool is_free_buddy_page(struct page *page);
  55 #endif
  56
  57
  58 /*
  59  * function for dealing with page's order in buddy system.
  60  * zone->lock is already acquired when we use these.
  61  * So, we don't need atomic page->flags operations here.
  62  */
  63 static inline unsigned long page_order(struct page *page)
  64 {
  65         /* PageBuddy() must be checked by the caller */
  66         return page_private(page);
  67 }
  68
  69 #ifdef CONFIG_MMU
  70 extern long mlock_vma_pages_range(struct vm_area_struct *vma,
  71                         unsigned long start, unsigned long end);
  72 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
  73                         unsigned long start, unsigned long end);
  74 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
  75 {
  76         munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
  77 }
  78
  79 /*
  80  * Called only in fault path via page_evictable() for a new page
  81  * to determine if it's being mapped into a LOCKED vma.
  82  * If so, mark page as mlocked.
  83  */
  84 static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
  85 {
  86         VM_BUG_ON(PageLRU(page));
  87
  88         if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
  89                 return 0;
  90
  91         if (!TestSetPageMlocked(page)) {
  92                 inc_zone_page_state(page, NR_MLOCK);
  93                 count_vm_event(UNEVICTABLE_PGMLOCKED);
  94         }
  95         return 1;
  96 }
  97
  98 /*
  99  * must be called with vma's mmap_sem held for read or write, and page locked.
 100  */
 101 extern void mlock_vma_page(struct page *page);
 102 extern void munlock_vma_page(struct page *page);
 103
 104 /*
 105  * Clear the page's PageMlocked().  This can be useful in a situation where
 106  * we want to unconditionally remove a page from the pagecache -- e.g.,
 107  * on truncation or freeing.
 108  *
 109  * It is legal to call this function for any page, mlocked or not.
 110  * If called for a page that is still mapped by mlocked vmas, all we do
 111  * is revert to lazy LRU behaviour -- semantics are not broken.
 112  */
 113 extern void __clear_page_mlock(struct page *page);
 114 static inline void clear_page_mlock(struct page *page)
 115 {
 116         if (unlikely(TestClearPageMlocked(page)))
 117                 __clear_page_mlock(page);
 118 }
 119
 120 /*
 121  * mlock_migrate_page - called only from migrate_page_copy() to
 122  * migrate the Mlocked page flag; update statistics.
 123  */
 124 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 125 {
 126         if (TestClearPageMlocked(page)) {
 127                 unsigned long flags;
 128
 129                 local_irq_save(flags);
 130                 __dec_zone_page_state(page, NR_MLOCK);
 131                 SetPageMlocked(newpage);
 132                 __inc_zone_page_state(newpage, NR_MLOCK);
 133                 local_irq_restore(flags);
 134         }
 135 }
 136
 137 #else /* !CONFIG_MMU */
 138 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 139 {
 140         return 0;
 141 }
 142 static inline void clear_page_mlock(struct page *page) { }
 143 static inline void mlock_vma_page(struct page *page) { }
 144 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
 145
 146 #endif /* !CONFIG_MMU */
 147
 148 /*
 149  * Return the mem_map entry representing the 'offset' subpage within
 150  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
 151  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
 152  */
 153 static inline struct page *mem_map_offset(struct page *base, int offset)
 154 {
 155         if (unlikely(offset >= MAX_ORDER_NR_PAGES))
 156                 return pfn_to_page(page_to_pfn(base) + offset);
 157         return base + offset;
 158 }
 159
 160 /*
 161  * Iterator over all subpages withing the maximally aligned gigantic
 162  * page 'base'.  Handle any discontiguity in the mem_map.
 163  */
 164 static inline struct page *mem_map_next(struct page *iter,
 165                                                 struct page *base, int offset)
 166 {
 167         if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
 168                 unsigned long pfn = page_to_pfn(base) + offset;
 169                 if (!pfn_valid(pfn))
 170                         return NULL;
 171                 return pfn_to_page(pfn);
 172         }
 173         return iter + 1;
 174 }
 175
 176 /*
 177  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
 178  * so all functions starting at paging_init should be marked __init
 179  * in those cases. SPARSEMEM, however, allows for memory hotplug,
 180  * and alloc_bootmem_node is not used.
 181  */
 182 #ifdef CONFIG_SPARSEMEM
 183 #define __paginginit __meminit
 184 #else
 185 #define __paginginit __init
 186 #endif
 187
 188 /* Memory initialisation debug and verification */
 189 enum mminit_level {
 190         MMINIT_WARNING,
 191         MMINIT_VERIFY,
 192         MMINIT_TRACE
 193 };
 194
 195 #ifdef CONFIG_DEBUG_MEMORY_INIT
 196
 197 extern int mminit_loglevel;
 198
 199 #define mminit_dprintk(level, prefix, fmt, arg...) \
 200 do { \
 201         if (level < mminit_loglevel) { \
 202                 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
 203                 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
 204         } \
 205 } while (0)
 206
 207 extern void mminit_verify_pageflags_layout(void);
 208 extern void mminit_verify_page_links(struct page *page,
 209                 enum zone_type zone, unsigned long nid, unsigned long pfn);
 210 extern void mminit_verify_zonelist(void);
 211
 212 #else
 213
 214 static inline void mminit_dprintk(enum mminit_level level,
 215                                 const char *prefix, const char *fmt, ...)
 216 {
 217 }
 218
 219 static inline void mminit_verify_pageflags_layout(void)
 220 {
 221 }
 222
 223 static inline void mminit_verify_page_links(struct page *page,
 224                 enum zone_type zone, unsigned long nid, unsigned long pfn)
 225 {
 226 }
 227
 228 static inline void mminit_verify_zonelist(void)
 229 {
 230 }
 231 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 232
 233 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
 234 #if defined(CONFIG_SPARSEMEM)
 235 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 236                                 unsigned long *end_pfn);
 237 #else
 238 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 239                                 unsigned long *end_pfn)
 240 {
 241 }
 242 #endif /* CONFIG_SPARSEMEM */
 243
 244 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 245                      unsigned long start, int len, unsigned int foll_flags,
 246                      struct page **pages, struct vm_area_struct **vmas);
 247
 248 #define ZONE_RECLAIM_NOSCAN     -2
 249 #define ZONE_RECLAIM_FULL       -1
 250 #define ZONE_RECLAIM_SOME       0
 251 #define ZONE_RECLAIM_SUCCESS    1
 252 #endif
 253
 254 extern int hwpoison_filter(struct page *p);
 255
 256 extern u32 hwpoison_filter_dev_major;
 257 extern u32 hwpoison_filter_dev_minor;
 258 extern u64 hwpoison_filter_flags_mask;
 259 extern u64 hwpoison_filter_flags_value;
 260 extern u64 hwpoison_filter_memcg;
 261 extern u32 hwpoison_filter_enable;