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