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 long mlock_vma_pages_range(struct vm_area_struct *vma,
  65                         unsigned long start, unsigned long end);
  66 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
  67                         unsigned long start, unsigned long end);
  68 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
  69 {
  70         munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
  71 }
  72
  73 #ifdef CONFIG_UNEVICTABLE_LRU
  74 /*
  75  * unevictable_migrate_page() called only from migrate_page_copy() to
  76  * migrate unevictable flag to new page.
  77  * Note that the old page has been isolated from the LRU lists at this
  78  * point so we don't need to worry about LRU statistics.
  79  */
  80 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  81 {
  82         if (TestClearPageUnevictable(old))
  83                 SetPageUnevictable(new);
  84 }
  85 #else
  86 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  87 {
  88 }
  89 #endif
  90
  91 #ifdef CONFIG_UNEVICTABLE_LRU
  92 /*
  93  * Called only in fault path via page_evictable() for a new page
  94  * to determine if it's being mapped into a LOCKED vma.
  95  * If so, mark page as mlocked.
  96  */
  97 static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
  98 {
  99         VM_BUG_ON(PageLRU(page));
 100
 101         if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
 102                 return 0;
 103
 104         if (!TestSetPageMlocked(page)) {
 105                 inc_zone_page_state(page, NR_MLOCK);
 106                 count_vm_event(UNEVICTABLE_PGMLOCKED);
 107         }
 108         return 1;
 109 }
 110
 111 /*
 112  * must be called with vma's mmap_sem held for read, and page locked.
 113  */
 114 extern void mlock_vma_page(struct page *page);
 115
 116 /*
 117  * Clear the page's PageMlocked().  This can be useful in a situation where
 118  * we want to unconditionally remove a page from the pagecache -- e.g.,
 119  * on truncation or freeing.
 120  *
 121  * It is legal to call this function for any page, mlocked or not.
 122  * If called for a page that is still mapped by mlocked vmas, all we do
 123  * is revert to lazy LRU behaviour -- semantics are not broken.
 124  */
 125 extern void __clear_page_mlock(struct page *page);
 126 static inline void clear_page_mlock(struct page *page)
 127 {
 128         if (unlikely(TestClearPageMlocked(page)))
 129                 __clear_page_mlock(page);
 130 }
 131
 132 /*
 133  * mlock_migrate_page - called only from migrate_page_copy() to
 134  * migrate the Mlocked page flag; update statistics.
 135  */
 136 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 137 {
 138         if (TestClearPageMlocked(page)) {
 139                 unsigned long flags;
 140
 141                 local_irq_save(flags);
 142                 __dec_zone_page_state(page, NR_MLOCK);
 143                 SetPageMlocked(newpage);
 144                 __inc_zone_page_state(newpage, NR_MLOCK);
 145                 local_irq_restore(flags);
 146         }
 147 }
 148
 149 /*
 150  * free_page_mlock() -- clean up attempts to free and mlocked() page.
 151  * Page should not be on lru, so no need to fix that up.
 152  * free_pages_check() will verify...
 153  */
 154 static inline void free_page_mlock(struct page *page)
 155 {
 156         if (unlikely(TestClearPageMlocked(page))) {
 157                 unsigned long flags;
 158
 159                 local_irq_save(flags);
 160                 __dec_zone_page_state(page, NR_MLOCK);
 161                 __count_vm_event(UNEVICTABLE_MLOCKFREED);
 162                 local_irq_restore(flags);
 163         }
 164 }
 165
 166 #else /* CONFIG_UNEVICTABLE_LRU */
 167 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 168 {
 169         return 0;
 170 }
 171 static inline void clear_page_mlock(struct page *page) { }
 172 static inline void mlock_vma_page(struct page *page) { }
 173 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
 174 static inline void free_page_mlock(struct page *page) { }
 175
 176 #endif /* CONFIG_UNEVICTABLE_LRU */
 177
 178 /*
 179  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
 180  * so all functions starting at paging_init should be marked __init
 181  * in those cases. SPARSEMEM, however, allows for memory hotplug,
 182  * and alloc_bootmem_node is not used.
 183  */
 184 #ifdef CONFIG_SPARSEMEM
 185 #define __paginginit __meminit
 186 #else
 187 #define __paginginit __init
 188 #endif
 189
 190 /* Memory initialisation debug and verification */
 191 enum mminit_level {
 192         MMINIT_WARNING,
 193         MMINIT_VERIFY,
 194         MMINIT_TRACE
 195 };
 196
 197 #ifdef CONFIG_DEBUG_MEMORY_INIT
 198
 199 extern int mminit_loglevel;
 200
 201 #define mminit_dprintk(level, prefix, fmt, arg...) \
 202 do { \
 203         if (level < mminit_loglevel) { \
 204                 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
 205                 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
 206         } \
 207 } while (0)
 208
 209 extern void mminit_verify_pageflags_layout(void);
 210 extern void mminit_verify_page_links(struct page *page,
 211                 enum zone_type zone, unsigned long nid, unsigned long pfn);
 212 extern void mminit_verify_zonelist(void);
 213
 214 #else
 215
 216 static inline void mminit_dprintk(enum mminit_level level,
 217                                 const char *prefix, const char *fmt, ...)
 218 {
 219 }
 220
 221 static inline void mminit_verify_pageflags_layout(void)
 222 {
 223 }
 224
 225 static inline void mminit_verify_page_links(struct page *page,
 226                 enum zone_type zone, unsigned long nid, unsigned long pfn)
 227 {
 228 }
 229
 230 static inline void mminit_verify_zonelist(void)
 231 {
 232 }
 233 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 234
 235 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
 236 #if defined(CONFIG_SPARSEMEM)
 237 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 238                                 unsigned long *end_pfn);
 239 #else
 240 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 241                                 unsigned long *end_pfn)
 242 {
 243 }
 244 #endif /* CONFIG_SPARSEMEM */
 245
 246 #define GUP_FLAGS_WRITE                  0x1
 247 #define GUP_FLAGS_FORCE                  0x2
 248 #define GUP_FLAGS_IGNORE_VMA_PERMISSIONS 0x4
 249
 250 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 251                      unsigned long start, int len, int flags,
 252                      struct page **pages, struct vm_area_struct **vmas);
 253
 254 #endif