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 extern long mlock_vma_pages_range(struct vm_area_struct *vma,
  67                         unsigned long start, unsigned long end);
  68 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
  69                         unsigned long start, unsigned long end);
  70 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
  71 {
  72         munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
  73 }
  74
  75 #ifdef CONFIG_UNEVICTABLE_LRU
  76 /*
  77  * unevictable_migrate_page() called only from migrate_page_copy() to
  78  * migrate unevictable flag to new page.
  79  * Note that the old page has been isolated from the LRU lists at this
  80  * point so we don't need to worry about LRU statistics.
  81  */
  82 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  83 {
  84         if (TestClearPageUnevictable(old))
  85                 SetPageUnevictable(new);
  86 }
  87 #else
  88 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  89 {
  90 }
  91 #endif
  92
  93 #ifdef CONFIG_UNEVICTABLE_LRU
  94 /*
  95  * Called only in fault path via page_evictable() for a new page
  96  * to determine if it's being mapped into a LOCKED vma.
  97  * If so, mark page as mlocked.
  98  */
  99 static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
 100 {
 101         VM_BUG_ON(PageLRU(page));
 102
 103         if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
 104                 return 0;
 105
 106         if (!TestSetPageMlocked(page)) {
 107                 inc_zone_page_state(page, NR_MLOCK);
 108                 count_vm_event(UNEVICTABLE_PGMLOCKED);
 109         }
 110         return 1;
 111 }
 112
 113 /*
 114  * must be called with vma's mmap_sem held for read, and page locked.
 115  */
 116 extern void mlock_vma_page(struct page *page);
 117
 118 /*
 119  * Clear the page's PageMlocked().  This can be useful in a situation where
 120  * we want to unconditionally remove a page from the pagecache -- e.g.,
 121  * on truncation or freeing.
 122  *
 123  * It is legal to call this function for any page, mlocked or not.
 124  * If called for a page that is still mapped by mlocked vmas, all we do
 125  * is revert to lazy LRU behaviour -- semantics are not broken.
 126  */
 127 extern void __clear_page_mlock(struct page *page);
 128 static inline void clear_page_mlock(struct page *page)
 129 {
 130         if (unlikely(TestClearPageMlocked(page)))
 131                 __clear_page_mlock(page);
 132 }
 133
 134 /*
 135  * mlock_migrate_page - called only from migrate_page_copy() to
 136  * migrate the Mlocked page flag; update statistics.
 137  */
 138 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 139 {
 140         if (TestClearPageMlocked(page)) {
 141                 unsigned long flags;
 142
 143                 local_irq_save(flags);
 144                 __dec_zone_page_state(page, NR_MLOCK);
 145                 SetPageMlocked(newpage);
 146                 __inc_zone_page_state(newpage, NR_MLOCK);
 147                 local_irq_restore(flags);
 148         }
 149 }
 150
 151 /*
 152  * free_page_mlock() -- clean up attempts to free and mlocked() page.
 153  * Page should not be on lru, so no need to fix that up.
 154  * free_pages_check() will verify...
 155  */
 156 static inline void free_page_mlock(struct page *page)
 157 {
 158         if (unlikely(TestClearPageMlocked(page))) {
 159                 unsigned long flags;
 160
 161                 local_irq_save(flags);
 162                 __dec_zone_page_state(page, NR_MLOCK);
 163                 __count_vm_event(UNEVICTABLE_MLOCKFREED);
 164                 local_irq_restore(flags);
 165         }
 166 }
 167
 168 #else /* CONFIG_UNEVICTABLE_LRU */
 169 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 170 {
 171         return 0;
 172 }
 173 static inline void clear_page_mlock(struct page *page) { }
 174 static inline void mlock_vma_page(struct page *page) { }
 175 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
 176 static inline void free_page_mlock(struct page *page) { }
 177
 178 #endif /* CONFIG_UNEVICTABLE_LRU */
 179
 180 /*
 181  * Return the mem_map entry representing the 'offset' subpage within
 182  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
 183  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
 184  */
 185 static inline struct page *mem_map_offset(struct page *base, int offset)
 186 {
 187         if (unlikely(offset >= MAX_ORDER_NR_PAGES))
 188                 return pfn_to_page(page_to_pfn(base) + offset);
 189         return base + offset;
 190 }
 191
 192 /*
 193  * Iterator over all subpages withing the maximally aligned gigantic
 194  * page 'base'.  Handle any discontiguity in the mem_map.
 195  */
 196 static inline struct page *mem_map_next(struct page *iter,
 197                                                 struct page *base, int offset)
 198 {
 199         if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
 200                 unsigned long pfn = page_to_pfn(base) + offset;
 201                 if (!pfn_valid(pfn))
 202                         return NULL;
 203                 return pfn_to_page(pfn);
 204         }
 205         return iter + 1;
 206 }
 207
 208 /*
 209  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
 210  * so all functions starting at paging_init should be marked __init
 211  * in those cases. SPARSEMEM, however, allows for memory hotplug,
 212  * and alloc_bootmem_node is not used.
 213  */
 214 #ifdef CONFIG_SPARSEMEM
 215 #define __paginginit __meminit
 216 #else
 217 #define __paginginit __init
 218 #endif
 219
 220 /* Memory initialisation debug and verification */
 221 enum mminit_level {
 222         MMINIT_WARNING,
 223         MMINIT_VERIFY,
 224         MMINIT_TRACE
 225 };
 226
 227 #ifdef CONFIG_DEBUG_MEMORY_INIT
 228
 229 extern int mminit_loglevel;
 230
 231 #define mminit_dprintk(level, prefix, fmt, arg...) \
 232 do { \
 233         if (level < mminit_loglevel) { \
 234                 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
 235                 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
 236         } \
 237 } while (0)
 238
 239 extern void mminit_verify_pageflags_layout(void);
 240 extern void mminit_verify_page_links(struct page *page,
 241                 enum zone_type zone, unsigned long nid, unsigned long pfn);
 242 extern void mminit_verify_zonelist(void);
 243
 244 #else
 245
 246 static inline void mminit_dprintk(enum mminit_level level,
 247                                 const char *prefix, const char *fmt, ...)
 248 {
 249 }
 250
 251 static inline void mminit_verify_pageflags_layout(void)
 252 {
 253 }
 254
 255 static inline void mminit_verify_page_links(struct page *page,
 256                 enum zone_type zone, unsigned long nid, unsigned long pfn)
 257 {
 258 }
 259
 260 static inline void mminit_verify_zonelist(void)
 261 {
 262 }
 263 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 264
 265 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
 266 #if defined(CONFIG_SPARSEMEM)
 267 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 268                                 unsigned long *end_pfn);
 269 #else
 270 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 271                                 unsigned long *end_pfn)
 272 {
 273 }
 274 #endif /* CONFIG_SPARSEMEM */
 275
 276 #define GUP_FLAGS_WRITE                  0x1
 277 #define GUP_FLAGS_FORCE                  0x2
 278 #define GUP_FLAGS_IGNORE_VMA_PERMISSIONS 0x4
 279 #define GUP_FLAGS_IGNORE_SIGKILL         0x8
 280
 281 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 282                      unsigned long start, int len, int flags,
 283                      struct page **pages, struct vm_area_struct **vmas);
 284
 285 #endif