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         VM_BUG_ON(!PageBuddy(page));
  63         return page_private(page);
  64 }
  65
  66 #ifdef CONFIG_MMU
  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
  76 /*
  77  * Called only in fault path via page_evictable() for a new page
  78  * to determine if it's being mapped into a LOCKED vma.
  79  * If so, mark page as mlocked.
  80  */
  81 static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
  82 {
  83         VM_BUG_ON(PageLRU(page));
  84
  85         if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
  86                 return 0;
  87
  88         if (!TestSetPageMlocked(page)) {
  89                 inc_zone_page_state(page, NR_MLOCK);
  90                 count_vm_event(UNEVICTABLE_PGMLOCKED);
  91         }
  92         return 1;
  93 }
  94
  95 /*
  96  * must be called with vma's mmap_sem held for read or write, and page locked.
  97  */
  98 extern void mlock_vma_page(struct page *page);
  99 extern void munlock_vma_page(struct page *page);
 100
 101 /*
 102  * Clear the page's PageMlocked().  This can be useful in a situation where
 103  * we want to unconditionally remove a page from the pagecache -- e.g.,
 104  * on truncation or freeing.
 105  *
 106  * It is legal to call this function for any page, mlocked or not.
 107  * If called for a page that is still mapped by mlocked vmas, all we do
 108  * is revert to lazy LRU behaviour -- semantics are not broken.
 109  */
 110 extern void __clear_page_mlock(struct page *page);
 111 static inline void clear_page_mlock(struct page *page)
 112 {
 113         if (unlikely(TestClearPageMlocked(page)))
 114                 __clear_page_mlock(page);
 115 }
 116
 117 /*
 118  * mlock_migrate_page - called only from migrate_page_copy() to
 119  * migrate the Mlocked page flag; update statistics.
 120  */
 121 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 122 {
 123         if (TestClearPageMlocked(page)) {
 124                 unsigned long flags;
 125
 126                 local_irq_save(flags);
 127                 __dec_zone_page_state(page, NR_MLOCK);
 128                 SetPageMlocked(newpage);
 129                 __inc_zone_page_state(newpage, NR_MLOCK);
 130                 local_irq_restore(flags);
 131         }
 132 }
 133
 134 #else /* !CONFIG_MMU */
 135 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 136 {
 137         return 0;
 138 }
 139 static inline void clear_page_mlock(struct page *page) { }
 140 static inline void mlock_vma_page(struct page *page) { }
 141 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
 142
 143 #endif /* !CONFIG_MMU */
 144
 145 /*
 146  * Return the mem_map entry representing the 'offset' subpage within
 147  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
 148  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
 149  */
 150 static inline struct page *mem_map_offset(struct page *base, int offset)
 151 {
 152         if (unlikely(offset >= MAX_ORDER_NR_PAGES))
 153                 return pfn_to_page(page_to_pfn(base) + offset);
 154         return base + offset;
 155 }
 156
 157 /*
 158  * Iterator over all subpages withing the maximally aligned gigantic
 159  * page 'base'.  Handle any discontiguity in the mem_map.
 160  */
 161 static inline struct page *mem_map_next(struct page *iter,
 162                                                 struct page *base, int offset)
 163 {
 164         if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
 165                 unsigned long pfn = page_to_pfn(base) + offset;
 166                 if (!pfn_valid(pfn))
 167                         return NULL;
 168                 return pfn_to_page(pfn);
 169         }
 170         return iter + 1;
 171 }
 172
 173 /*
 174  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
 175  * so all functions starting at paging_init should be marked __init
 176  * in those cases. SPARSEMEM, however, allows for memory hotplug,
 177  * and alloc_bootmem_node is not used.
 178  */
 179 #ifdef CONFIG_SPARSEMEM
 180 #define __paginginit __meminit
 181 #else
 182 #define __paginginit __init
 183 #endif
 184
 185 /* Memory initialisation debug and verification */
 186 enum mminit_level {
 187         MMINIT_WARNING,
 188         MMINIT_VERIFY,
 189         MMINIT_TRACE
 190 };
 191
 192 #ifdef CONFIG_DEBUG_MEMORY_INIT
 193
 194 extern int mminit_loglevel;
 195
 196 #define mminit_dprintk(level, prefix, fmt, arg...) \
 197 do { \
 198         if (level < mminit_loglevel) { \
 199                 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
 200                 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
 201         } \
 202 } while (0)
 203
 204 extern void mminit_verify_pageflags_layout(void);
 205 extern void mminit_verify_page_links(struct page *page,
 206                 enum zone_type zone, unsigned long nid, unsigned long pfn);
 207 extern void mminit_verify_zonelist(void);
 208
 209 #else
 210
 211 static inline void mminit_dprintk(enum mminit_level level,
 212                                 const char *prefix, const char *fmt, ...)
 213 {
 214 }
 215
 216 static inline void mminit_verify_pageflags_layout(void)
 217 {
 218 }
 219
 220 static inline void mminit_verify_page_links(struct page *page,
 221                 enum zone_type zone, unsigned long nid, unsigned long pfn)
 222 {
 223 }
 224
 225 static inline void mminit_verify_zonelist(void)
 226 {
 227 }
 228 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 229
 230 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
 231 #if defined(CONFIG_SPARSEMEM)
 232 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 233                                 unsigned long *end_pfn);
 234 #else
 235 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 236                                 unsigned long *end_pfn)
 237 {
 238 }
 239 #endif /* CONFIG_SPARSEMEM */
 240
 241 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 242                      unsigned long start, int len, unsigned int foll_flags,
 243                      struct page **pages, struct vm_area_struct **vmas);
 244
 245 #define ZONE_RECLAIM_NOSCAN     -2
 246 #define ZONE_RECLAIM_FULL       -1
 247 #define ZONE_RECLAIM_SOME       0
 248 #define ZONE_RECLAIM_SUCCESS    1
 249 #endif