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 extern void prep_compound_page(struct page *page, unsigned long order);
  20
  21 static inline void set_page_count(struct page *page, int v)
  22 {
  23         atomic_set(&page->_count, v);
  24 }
  25
  26 /*
  27  * Turn a non-refcounted page (->_count == 0) into refcounted with
  28  * a count of one.
  29  */
  30 static inline void set_page_refcounted(struct page *page)
  31 {
  32         VM_BUG_ON(PageTail(page));
  33         VM_BUG_ON(atomic_read(&page->_count));
  34         set_page_count(page, 1);
  35 }
  36
  37 static inline void __put_page(struct page *page)
  38 {
  39         atomic_dec(&page->_count);
  40 }
  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
  53 /*
  54  * function for dealing with page's order in buddy system.
  55  * zone->lock is already acquired when we use these.
  56  * So, we don't need atomic page->flags operations here.
  57  */
  58 static inline unsigned long page_order(struct page *page)
  59 {
  60         VM_BUG_ON(!PageBuddy(page));
  61         return page_private(page);
  62 }
  63
  64 extern int mlock_vma_pages_range(struct vm_area_struct *vma,
  65                         unsigned long start, unsigned long end);
  66 extern void munlock_vma_pages_all(struct vm_area_struct *vma);
  67
  68 #ifdef CONFIG_UNEVICTABLE_LRU
  69 /*
  70  * unevictable_migrate_page() called only from migrate_page_copy() to
  71  * migrate unevictable flag to new page.
  72  * Note that the old page has been isolated from the LRU lists at this
  73  * point so we don't need to worry about LRU statistics.
  74  */
  75 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  76 {
  77         if (TestClearPageUnevictable(old))
  78                 SetPageUnevictable(new);
  79 }
  80 #else
  81 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  82 {
  83 }
  84 #endif
  85
  86 #ifdef CONFIG_UNEVICTABLE_LRU
  87 /*
  88  * Called only in fault path via page_evictable() for a new page
  89  * to determine if it's being mapped into a LOCKED vma.
  90  * If so, mark page as mlocked.
  91  */
  92 static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
  93 {
  94         VM_BUG_ON(PageLRU(page));
  95
  96         if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
  97                 return 0;
  98
  99         SetPageMlocked(page);
 100         return 1;
 101 }
 102
 103 /*
 104  * must be called with vma's mmap_sem held for read, and page locked.
 105  */
 106 extern void mlock_vma_page(struct page *page);
 107
 108 /*
 109  * Clear the page's PageMlocked().  This can be useful in a situation where
 110  * we want to unconditionally remove a page from the pagecache -- e.g.,
 111  * on truncation or freeing.
 112  *
 113  * It is legal to call this function for any page, mlocked or not.
 114  * If called for a page that is still mapped by mlocked vmas, all we do
 115  * is revert to lazy LRU behaviour -- semantics are not broken.
 116  */
 117 extern void __clear_page_mlock(struct page *page);
 118 static inline void clear_page_mlock(struct page *page)
 119 {
 120         if (unlikely(TestClearPageMlocked(page)))
 121                 __clear_page_mlock(page);
 122 }
 123
 124 /*
 125  * mlock_migrate_page - called only from migrate_page_copy() to
 126  * migrate the Mlocked page flag
 127  */
 128 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 129 {
 130         if (TestClearPageMlocked(page))
 131                 SetPageMlocked(newpage);
 132 }
 133
 134
 135 #else /* CONFIG_UNEVICTABLE_LRU */
 136 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 137 {
 138         return 0;
 139 }
 140 static inline void clear_page_mlock(struct page *page) { }
 141 static inline void mlock_vma_page(struct page *page) { }
 142 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
 143
 144 #endif /* CONFIG_UNEVICTABLE_LRU */
 145
 146 /*
 147  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
 148  * so all functions starting at paging_init should be marked __init
 149  * in those cases. SPARSEMEM, however, allows for memory hotplug,
 150  * and alloc_bootmem_node is not used.
 151  */
 152 #ifdef CONFIG_SPARSEMEM
 153 #define __paginginit __meminit
 154 #else
 155 #define __paginginit __init
 156 #endif
 157
 158 /* Memory initialisation debug and verification */
 159 enum mminit_level {
 160         MMINIT_WARNING,
 161         MMINIT_VERIFY,
 162         MMINIT_TRACE
 163 };
 164
 165 #ifdef CONFIG_DEBUG_MEMORY_INIT
 166
 167 extern int mminit_loglevel;
 168
 169 #define mminit_dprintk(level, prefix, fmt, arg...) \
 170 do { \
 171         if (level < mminit_loglevel) { \
 172                 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
 173                 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
 174         } \
 175 } while (0)
 176
 177 extern void mminit_verify_pageflags_layout(void);
 178 extern void mminit_verify_page_links(struct page *page,
 179                 enum zone_type zone, unsigned long nid, unsigned long pfn);
 180 extern void mminit_verify_zonelist(void);
 181
 182 #else
 183
 184 static inline void mminit_dprintk(enum mminit_level level,
 185                                 const char *prefix, const char *fmt, ...)
 186 {
 187 }
 188
 189 static inline void mminit_verify_pageflags_layout(void)
 190 {
 191 }
 192
 193 static inline void mminit_verify_page_links(struct page *page,
 194                 enum zone_type zone, unsigned long nid, unsigned long pfn)
 195 {
 196 }
 197
 198 static inline void mminit_verify_zonelist(void)
 199 {
 200 }
 201 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 202
 203 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
 204 #if defined(CONFIG_SPARSEMEM)
 205 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 206                                 unsigned long *end_pfn);
 207 #else
 208 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 209                                 unsigned long *end_pfn)
 210 {
 211 }
 212 #endif /* CONFIG_SPARSEMEM */
 213
 214 #define GUP_FLAGS_WRITE                  0x1
 215 #define GUP_FLAGS_FORCE                  0x2
 216 #define GUP_FLAGS_IGNORE_VMA_PERMISSIONS 0x4
 217
 218 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 219                      unsigned long start, int len, int flags,
 220                      struct page **pages, struct vm_area_struct **vmas);
 221
 222 #endif