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 static inline void set_page_count(struct page *page, int v)
  20 {
  21         atomic_set(&page->_count, v);
  22 }
  23
  24 /*
  25  * Turn a non-refcounted page (->_count == 0) into refcounted with
  26  * a count of one.
  27  */
  28 static inline void set_page_refcounted(struct page *page)
  29 {
  30         VM_BUG_ON(PageTail(page));
  31         VM_BUG_ON(atomic_read(&page->_count));
  32         set_page_count(page, 1);
  33 }
  34
  35 static inline void __put_page(struct page *page)
  36 {
  37         atomic_dec(&page->_count);
  38 }
  39
  40 extern unsigned long highest_memmap_pfn;
  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 extern void prep_compound_page(struct page *page, unsigned long order);
  53
  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         /* PageBuddy() must be checked by the caller */
  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 /*
  78  * unevictable_migrate_page() called only from migrate_page_copy() to
  79  * migrate unevictable flag to new page.
  80  * Note that the old page has been isolated from the LRU lists at this
  81  * point so we don't need to worry about LRU statistics.
  82  */
  83 static inline void unevictable_migrate_page(struct page *new, struct page *old)
  84 {
  85         if (TestClearPageUnevictable(old))
  86                 SetPageUnevictable(new);
  87 }
  88
  89 #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
  90 /*
  91  * Called only in fault path via page_evictable() for a new page
  92  * to determine if it's being mapped into a LOCKED vma.
  93  * If so, mark page as mlocked.
  94  */
  95 static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
  96 {
  97         VM_BUG_ON(PageLRU(page));
  98
  99         if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
 100                 return 0;
 101
 102         if (!TestSetPageMlocked(page)) {
 103                 inc_zone_page_state(page, NR_MLOCK);
 104                 count_vm_event(UNEVICTABLE_PGMLOCKED);
 105         }
 106         return 1;
 107 }
 108
 109 /*
 110  * must be called with vma's mmap_sem held for read or write, and page locked.
 111  */
 112 extern void mlock_vma_page(struct page *page);
 113 extern void munlock_vma_page(struct page *page);
 114
 115 /*
 116  * Clear the page's PageMlocked().  This can be useful in a situation where
 117  * we want to unconditionally remove a page from the pagecache -- e.g.,
 118  * on truncation or freeing.
 119  *
 120  * It is legal to call this function for any page, mlocked or not.
 121  * If called for a page that is still mapped by mlocked vmas, all we do
 122  * is revert to lazy LRU behaviour -- semantics are not broken.
 123  */
 124 extern void __clear_page_mlock(struct page *page);
 125 static inline void clear_page_mlock(struct page *page)
 126 {
 127         if (unlikely(TestClearPageMlocked(page)))
 128                 __clear_page_mlock(page);
 129 }
 130
 131 /*
 132  * mlock_migrate_page - called only from migrate_page_copy() to
 133  * migrate the Mlocked page flag; update statistics.
 134  */
 135 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 136 {
 137         if (TestClearPageMlocked(page)) {
 138                 unsigned long flags;
 139
 140                 local_irq_save(flags);
 141                 __dec_zone_page_state(page, NR_MLOCK);
 142                 SetPageMlocked(newpage);
 143                 __inc_zone_page_state(newpage, NR_MLOCK);
 144                 local_irq_restore(flags);
 145         }
 146 }
 147
 148 #else /* CONFIG_HAVE_MLOCKED_PAGE_BIT */
 149 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 150 {
 151         return 0;
 152 }
 153 static inline void clear_page_mlock(struct page *page) { }
 154 static inline void mlock_vma_page(struct page *page) { }
 155 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
 156
 157 #endif /* CONFIG_HAVE_MLOCKED_PAGE_BIT */
 158
 159 /*
 160  * Return the mem_map entry representing the 'offset' subpage within
 161  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
 162  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
 163  */
 164 static inline struct page *mem_map_offset(struct page *base, int offset)
 165 {
 166         if (unlikely(offset >= MAX_ORDER_NR_PAGES))
 167                 return pfn_to_page(page_to_pfn(base) + offset);
 168         return base + offset;
 169 }
 170
 171 /*
 172  * Iterator over all subpages withing the maximally aligned gigantic
 173  * page 'base'.  Handle any discontiguity in the mem_map.
 174  */
 175 static inline struct page *mem_map_next(struct page *iter,
 176                                                 struct page *base, int offset)
 177 {
 178         if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
 179                 unsigned long pfn = page_to_pfn(base) + offset;
 180                 if (!pfn_valid(pfn))
 181                         return NULL;
 182                 return pfn_to_page(pfn);
 183         }
 184         return iter + 1;
 185 }
 186
 187 /*
 188  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
 189  * so all functions starting at paging_init should be marked __init
 190  * in those cases. SPARSEMEM, however, allows for memory hotplug,
 191  * and alloc_bootmem_node is not used.
 192  */
 193 #ifdef CONFIG_SPARSEMEM
 194 #define __paginginit __meminit
 195 #else
 196 #define __paginginit __init
 197 #endif
 198
 199 /* Memory initialisation debug and verification */
 200 enum mminit_level {
 201         MMINIT_WARNING,
 202         MMINIT_VERIFY,
 203         MMINIT_TRACE
 204 };
 205
 206 #ifdef CONFIG_DEBUG_MEMORY_INIT
 207
 208 extern int mminit_loglevel;
 209
 210 #define mminit_dprintk(level, prefix, fmt, arg...) \
 211 do { \
 212         if (level < mminit_loglevel) { \
 213                 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
 214                 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
 215         } \
 216 } while (0)
 217
 218 extern void mminit_verify_pageflags_layout(void);
 219 extern void mminit_verify_page_links(struct page *page,
 220                 enum zone_type zone, unsigned long nid, unsigned long pfn);
 221 extern void mminit_verify_zonelist(void);
 222
 223 #else
 224
 225 static inline void mminit_dprintk(enum mminit_level level,
 226                                 const char *prefix, const char *fmt, ...)
 227 {
 228 }
 229
 230 static inline void mminit_verify_pageflags_layout(void)
 231 {
 232 }
 233
 234 static inline void mminit_verify_page_links(struct page *page,
 235                 enum zone_type zone, unsigned long nid, unsigned long pfn)
 236 {
 237 }
 238
 239 static inline void mminit_verify_zonelist(void)
 240 {
 241 }
 242 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 243
 244 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
 245 #if defined(CONFIG_SPARSEMEM)
 246 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 247                                 unsigned long *end_pfn);
 248 #else
 249 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 250                                 unsigned long *end_pfn)
 251 {
 252 }
 253 #endif /* CONFIG_SPARSEMEM */
 254
 255 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 256                      unsigned long start, int len, unsigned int foll_flags,
 257                      struct page **pages, struct vm_area_struct **vmas);
 258
 259 #define ZONE_RECLAIM_NOSCAN     -2
 260 #define ZONE_RECLAIM_FULL       -1
 261 #define ZONE_RECLAIM_SOME       0
 262 #define ZONE_RECLAIM_SUCCESS    1
 263 #endif