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