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 void __free_pages_bootmem(struct page *page, unsigned int order);
  53
  54 /*
  55  * function for dealing with page's order in buddy system.
  56  * zone->lock is already acquired when we use these.
  57  * So, we don't need atomic page->flags operations here.
  58  */
  59 static inline unsigned long page_order(struct page *page)
  60 {
  61         VM_BUG_ON(!PageBuddy(page));
  62         return page_private(page);
  63 }
  64
  65 extern long mlock_vma_pages_range(struct vm_area_struct *vma,
  66                         unsigned long start, unsigned long end);
  67 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
  68                         unsigned long start, unsigned long end);
  69 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
  70 {
  71         munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
  72 }
  73
  74 #ifdef CONFIG_UNEVICTABLE_LRU
  75 /*
  76  * unevictable_migrate_page() called only from migrate_page_copy() to
  77  * migrate unevictable flag to new page.
  78  * Note that the old page has been isolated from the LRU lists at this
  79  * point so we don't need to worry about LRU statistics.
  80  */
  81 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  82 {
  83         if (TestClearPageUnevictable(old))
  84                 SetPageUnevictable(new);
  85 }
  86 #else
  87 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  88 {
  89 }
  90 #endif
  91
  92 #ifdef CONFIG_UNEVICTABLE_LRU
  93 /*
  94  * Called only in fault path via page_evictable() for a new page
  95  * to determine if it's being mapped into a LOCKED vma.
  96  * If so, mark page as mlocked.
  97  */
  98 static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
  99 {
 100         VM_BUG_ON(PageLRU(page));
 101
 102         if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
 103                 return 0;
 104
 105         if (!TestSetPageMlocked(page)) {
 106                 inc_zone_page_state(page, NR_MLOCK);
 107                 count_vm_event(UNEVICTABLE_PGMLOCKED);
 108         }
 109         return 1;
 110 }
 111
 112 /*
 113  * must be called with vma's mmap_sem held for read, and page locked.
 114  */
 115 extern void mlock_vma_page(struct page *page);
 116
 117 /*
 118  * Clear the page's PageMlocked().  This can be useful in a situation where
 119  * we want to unconditionally remove a page from the pagecache -- e.g.,
 120  * on truncation or freeing.
 121  *
 122  * It is legal to call this function for any page, mlocked or not.
 123  * If called for a page that is still mapped by mlocked vmas, all we do
 124  * is revert to lazy LRU behaviour -- semantics are not broken.
 125  */
 126 extern void __clear_page_mlock(struct page *page);
 127 static inline void clear_page_mlock(struct page *page)
 128 {
 129         if (unlikely(TestClearPageMlocked(page)))
 130                 __clear_page_mlock(page);
 131 }
 132
 133 /*
 134  * mlock_migrate_page - called only from migrate_page_copy() to
 135  * migrate the Mlocked page flag; update statistics.
 136  */
 137 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 138 {
 139         if (TestClearPageMlocked(page)) {
 140                 unsigned long flags;
 141
 142                 local_irq_save(flags);
 143                 __dec_zone_page_state(page, NR_MLOCK);
 144                 SetPageMlocked(newpage);
 145                 __inc_zone_page_state(newpage, NR_MLOCK);
 146                 local_irq_restore(flags);
 147         }
 148 }
 149
 150 /*
 151  * free_page_mlock() -- clean up attempts to free and mlocked() page.
 152  * Page should not be on lru, so no need to fix that up.
 153  * free_pages_check() will verify...
 154  */
 155 static inline void free_page_mlock(struct page *page)
 156 {
 157         if (unlikely(TestClearPageMlocked(page))) {
 158                 unsigned long flags;
 159
 160                 local_irq_save(flags);
 161                 __dec_zone_page_state(page, NR_MLOCK);
 162                 __count_vm_event(UNEVICTABLE_MLOCKFREED);
 163                 local_irq_restore(flags);
 164         }
 165 }
 166
 167 #else /* CONFIG_UNEVICTABLE_LRU */
 168 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 169 {
 170         return 0;
 171 }
 172 static inline void clear_page_mlock(struct page *page) { }
 173 static inline void mlock_vma_page(struct page *page) { }
 174 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
 175 static inline void free_page_mlock(struct page *page) { }
 176
 177 #endif /* CONFIG_UNEVICTABLE_LRU */
 178
 179 /*
 180  * Return the mem_map entry representing the 'offset' subpage within
 181  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
 182  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
 183  */
 184 static inline struct page *mem_map_offset(struct page *base, int offset)
 185 {
 186         if (unlikely(offset >= MAX_ORDER_NR_PAGES))
 187                 return pfn_to_page(page_to_pfn(base) + offset);
 188         return base + offset;
 189 }
 190
 191 /*
 192  * Iterator over all subpages withing the maximally aligned gigantic
 193  * page 'base'.  Handle any discontiguity in the mem_map.
 194  */
 195 static inline struct page *mem_map_next(struct page *iter,
 196                                                 struct page *base, int offset)
 197 {
 198         if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
 199                 unsigned long pfn = page_to_pfn(base) + offset;
 200                 if (!pfn_valid(pfn))
 201                         return NULL;
 202                 return pfn_to_page(pfn);
 203         }
 204         return iter + 1;
 205 }
 206
 207 /*
 208  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
 209  * so all functions starting at paging_init should be marked __init
 210  * in those cases. SPARSEMEM, however, allows for memory hotplug,
 211  * and alloc_bootmem_node is not used.
 212  */
 213 #ifdef CONFIG_SPARSEMEM
 214 #define __paginginit __meminit
 215 #else
 216 #define __paginginit __init
 217 #endif
 218
 219 /* Memory initialisation debug and verification */
 220 enum mminit_level {
 221         MMINIT_WARNING,
 222         MMINIT_VERIFY,
 223         MMINIT_TRACE
 224 };
 225
 226 #ifdef CONFIG_DEBUG_MEMORY_INIT
 227
 228 extern int mminit_loglevel;
 229
 230 #define mminit_dprintk(level, prefix, fmt, arg...) \
 231 do { \
 232         if (level < mminit_loglevel) { \
 233                 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
 234                 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
 235         } \
 236 } while (0)
 237
 238 extern void mminit_verify_pageflags_layout(void);
 239 extern void mminit_verify_page_links(struct page *page,
 240                 enum zone_type zone, unsigned long nid, unsigned long pfn);
 241 extern void mminit_verify_zonelist(void);
 242
 243 #else
 244
 245 static inline void mminit_dprintk(enum mminit_level level,
 246                                 const char *prefix, const char *fmt, ...)
 247 {
 248 }
 249
 250 static inline void mminit_verify_pageflags_layout(void)
 251 {
 252 }
 253
 254 static inline void mminit_verify_page_links(struct page *page,
 255                 enum zone_type zone, unsigned long nid, unsigned long pfn)
 256 {
 257 }
 258
 259 static inline void mminit_verify_zonelist(void)
 260 {
 261 }
 262 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 263
 264 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
 265 #if defined(CONFIG_SPARSEMEM)
 266 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 267                                 unsigned long *end_pfn);
 268 #else
 269 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 270                                 unsigned long *end_pfn)
 271 {
 272 }
 273 #endif /* CONFIG_SPARSEMEM */
 274
 275 #define GUP_FLAGS_WRITE                  0x1
 276 #define GUP_FLAGS_FORCE                  0x2
 277 #define GUP_FLAGS_IGNORE_VMA_PERMISSIONS 0x4
 278
 279 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 280                      unsigned long start, int len, int flags,
 281                      struct page **pages, struct vm_area_struct **vmas);
 282
 283 #endif