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 extern void prep_compound_gigantic_page(struct page *page, unsigned long order);
  21
  22 static inline void set_page_count(struct page *page, int v)
  23 {
  24         atomic_set(&page->_count, v);
  25 }
  26
  27 /*
  28  * Turn a non-refcounted page (->_count == 0) into refcounted with
  29  * a count of one.
  30  */
  31 static inline void set_page_refcounted(struct page *page)
  32 {
  33         VM_BUG_ON(PageTail(page));
  34         VM_BUG_ON(atomic_read(&page->_count));
  35         set_page_count(page, 1);
  36 }
  37
  38 static inline void __put_page(struct page *page)
  39 {
  40         atomic_dec(&page->_count);
  41 }
  42
  43 /*
  44  * in mm/vmscan.c:
  45  */
  46 extern int isolate_lru_page(struct page *page);
  47 extern void putback_lru_page(struct page *page);
  48
  49 /*
  50  * in mm/page_alloc.c
  51  */
  52 extern unsigned long highest_memmap_pfn;
  53 extern void __free_pages_bootmem(struct page *page, unsigned int order);
  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 #ifdef CONFIG_UNEVICTABLE_LRU
  78 /*
  79  * unevictable_migrate_page() called only from migrate_page_copy() to
  80  * migrate unevictable flag to new page.
  81  * Note that the old page has been isolated from the LRU lists at this
  82  * point so we don't need to worry about LRU statistics.
  83  */
  84 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  85 {
  86         if (TestClearPageUnevictable(old))
  87                 SetPageUnevictable(new);
  88 }
  89 #else
  90 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  91 {
  92 }
  93 #endif
  94
  95 #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
  96 /*
  97  * Called only in fault path via page_evictable() for a new page
  98  * to determine if it's being mapped into a LOCKED vma.
  99  * If so, mark page as mlocked.
 100  */
 101 static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
 102 {
 103         VM_BUG_ON(PageLRU(page));
 104
 105         if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
 106                 return 0;
 107
 108         if (!TestSetPageMlocked(page)) {
 109                 inc_zone_page_state(page, NR_MLOCK);
 110                 count_vm_event(UNEVICTABLE_PGMLOCKED);
 111         }
 112         return 1;
 113 }
 114
 115 /*
 116  * must be called with vma's mmap_sem held for read, and page locked.
 117  */
 118 extern void mlock_vma_page(struct page *page);
 119
 120 /*
 121  * Clear the page's PageMlocked().  This can be useful in a situation where
 122  * we want to unconditionally remove a page from the pagecache -- e.g.,
 123  * on truncation or freeing.
 124  *
 125  * It is legal to call this function for any page, mlocked or not.
 126  * If called for a page that is still mapped by mlocked vmas, all we do
 127  * is revert to lazy LRU behaviour -- semantics are not broken.
 128  */
 129 extern void __clear_page_mlock(struct page *page);
 130 static inline void clear_page_mlock(struct page *page)
 131 {
 132         if (unlikely(TestClearPageMlocked(page)))
 133                 __clear_page_mlock(page);
 134 }
 135
 136 /*
 137  * mlock_migrate_page - called only from migrate_page_copy() to
 138  * migrate the Mlocked page flag; update statistics.
 139  */
 140 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 141 {
 142         if (TestClearPageMlocked(page)) {
 143                 unsigned long flags;
 144
 145                 local_irq_save(flags);
 146                 __dec_zone_page_state(page, NR_MLOCK);
 147                 SetPageMlocked(newpage);
 148                 __inc_zone_page_state(newpage, NR_MLOCK);
 149                 local_irq_restore(flags);
 150         }
 151 }
 152
 153 #else /* CONFIG_HAVE_MLOCKED_PAGE_BIT */
 154 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 155 {
 156         return 0;
 157 }
 158 static inline void clear_page_mlock(struct page *page) { }
 159 static inline void mlock_vma_page(struct page *page) { }
 160 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
 161
 162 #endif /* CONFIG_HAVE_MLOCKED_PAGE_BIT */
 163
 164 /*
 165  * Return the mem_map entry representing the 'offset' subpage within
 166  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
 167  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
 168  */
 169 static inline struct page *mem_map_offset(struct page *base, int offset)
 170 {
 171         if (unlikely(offset >= MAX_ORDER_NR_PAGES))
 172                 return pfn_to_page(page_to_pfn(base) + offset);
 173         return base + offset;
 174 }
 175
 176 /*
 177  * Iterator over all subpages withing the maximally aligned gigantic
 178  * page 'base'.  Handle any discontiguity in the mem_map.
 179  */
 180 static inline struct page *mem_map_next(struct page *iter,
 181                                                 struct page *base, int offset)
 182 {
 183         if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
 184                 unsigned long pfn = page_to_pfn(base) + offset;
 185                 if (!pfn_valid(pfn))
 186                         return NULL;
 187                 return pfn_to_page(pfn);
 188         }
 189         return iter + 1;
 190 }
 191
 192 /*
 193  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
 194  * so all functions starting at paging_init should be marked __init
 195  * in those cases. SPARSEMEM, however, allows for memory hotplug,
 196  * and alloc_bootmem_node is not used.
 197  */
 198 #ifdef CONFIG_SPARSEMEM
 199 #define __paginginit __meminit
 200 #else
 201 #define __paginginit __init
 202 #endif
 203
 204 /* Memory initialisation debug and verification */
 205 enum mminit_level {
 206         MMINIT_WARNING,
 207         MMINIT_VERIFY,
 208         MMINIT_TRACE
 209 };
 210
 211 #ifdef CONFIG_DEBUG_MEMORY_INIT
 212
 213 extern int mminit_loglevel;
 214
 215 #define mminit_dprintk(level, prefix, fmt, arg...) \
 216 do { \
 217         if (level < mminit_loglevel) { \
 218                 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
 219                 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
 220         } \
 221 } while (0)
 222
 223 extern void mminit_verify_pageflags_layout(void);
 224 extern void mminit_verify_page_links(struct page *page,
 225                 enum zone_type zone, unsigned long nid, unsigned long pfn);
 226 extern void mminit_verify_zonelist(void);
 227
 228 #else
 229
 230 static inline void mminit_dprintk(enum mminit_level level,
 231                                 const char *prefix, const char *fmt, ...)
 232 {
 233 }
 234
 235 static inline void mminit_verify_pageflags_layout(void)
 236 {
 237 }
 238
 239 static inline void mminit_verify_page_links(struct page *page,
 240                 enum zone_type zone, unsigned long nid, unsigned long pfn)
 241 {
 242 }
 243
 244 static inline void mminit_verify_zonelist(void)
 245 {
 246 }
 247 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 248
 249 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
 250 #if defined(CONFIG_SPARSEMEM)
 251 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 252                                 unsigned long *end_pfn);
 253 #else
 254 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 255                                 unsigned long *end_pfn)
 256 {
 257 }
 258 #endif /* CONFIG_SPARSEMEM */
 259
 260 #define GUP_FLAGS_WRITE                  0x1
 261 #define GUP_FLAGS_FORCE                  0x2
 262 #define GUP_FLAGS_IGNORE_VMA_PERMISSIONS 0x4
 263 #define GUP_FLAGS_IGNORE_SIGKILL         0x8
 264
 265 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 266                      unsigned long start, int len, int flags,
 267                      struct page **pages, struct vm_area_struct **vmas);
 268
 269 #endif