include/linux/gfp.h

   1 #ifndef __LINUX_GFP_H
   2 #define __LINUX_GFP_H
   3
   4 #include <linux/mmzone.h>
   5 #include <linux/stddef.h>
   6 #include <linux/linkage.h>
   7
   8 struct vm_area_struct;
   9
  10 /*
  11  * GFP bitmasks..
  12  *
  13  * Zone modifiers (see linux/mmzone.h - low three bits)
  14  *
  15  * Do not put any conditional on these. If necessary modify the definitions
  16  * without the underscores and use the consistently. The definitions here may
  17  * be used in bit comparisons.
  18  */
  19 #define __GFP_DMA       ((__force gfp_t)0x01u)
  20 #define __GFP_HIGHMEM   ((__force gfp_t)0x02u)
  21 #define __GFP_DMA32     ((__force gfp_t)0x04u)
  22
  23 /*
  24  * Action modifiers - doesn't change the zoning
  25  *
  26  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  27  * _might_ fail.  This depends upon the particular VM implementation.
  28  *
  29  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  30  * cannot handle allocation failures.
  31  *
  32  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  33  *
  34  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  35  * mechanism or reclaimed
  36  */
  37 #define __GFP_WAIT      ((__force gfp_t)0x10u)  /* Can wait and reschedule? */
  38 #define __GFP_HIGH      ((__force gfp_t)0x20u)  /* Should access emergency pools? */
  39 #define __GFP_IO        ((__force gfp_t)0x40u)  /* Can start physical IO? */
  40 #define __GFP_FS        ((__force gfp_t)0x80u)  /* Can call down to low-level FS? */
  41 #define __GFP_COLD      ((__force gfp_t)0x100u) /* Cache-cold page required */
  42 #define __GFP_NOWARN    ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
  43 #define __GFP_REPEAT    ((__force gfp_t)0x400u) /* Retry the allocation.  Might fail */
  44 #define __GFP_NOFAIL    ((__force gfp_t)0x800u) /* Retry for ever.  Cannot fail */
  45 #define __GFP_NORETRY   ((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
  46 #define __GFP_COMP      ((__force gfp_t)0x4000u)/* Add compound page metadata */
  47 #define __GFP_ZERO      ((__force gfp_t)0x8000u)/* Return zeroed page on success */
  48 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
  49 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
  50 #define __GFP_THISNODE  ((__force gfp_t)0x40000u)/* No fallback, no policies */
  51 #define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */
  52 #define __GFP_MOVABLE   ((__force gfp_t)0x100000u)  /* Page is movable */
  53
  54 #define __GFP_BITS_SHIFT 21     /* Room for 21 __GFP_FOO bits */
  55 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  56
  57 /* This equals 0, but use constants in case they ever change */
  58 #define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
  59 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
  60 #define GFP_ATOMIC      (__GFP_HIGH)
  61 #define GFP_NOIO        (__GFP_WAIT)
  62 #define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
  63 #define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
  64 #define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  65                          __GFP_RECLAIMABLE)
  66 #define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
  67 #define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
  68                          __GFP_HIGHMEM)
  69 #define GFP_HIGHUSER_MOVABLE    (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  70                                  __GFP_HARDWALL | __GFP_HIGHMEM | \
  71                                  __GFP_MOVABLE)
  72 #define GFP_NOFS_PAGECACHE      (__GFP_WAIT | __GFP_IO | __GFP_MOVABLE)
  73 #define GFP_USER_PAGECACHE      (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  74                                  __GFP_HARDWALL | __GFP_MOVABLE)
  75 #define GFP_HIGHUSER_PAGECACHE  (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  76                                  __GFP_HARDWALL | __GFP_HIGHMEM | \
  77                                  __GFP_MOVABLE)
  78
  79 #ifdef CONFIG_NUMA
  80 #define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  81 #else
  82 #define GFP_THISNODE    ((__force gfp_t)0)
  83 #endif
  84
  85 /* This mask makes up all the page movable related flags */
  86 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
  87
  88 /* Control page allocator reclaim behavior */
  89 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
  90                         __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
  91                         __GFP_NORETRY|__GFP_NOMEMALLOC)
  92
  93 /* Control allocation constraints */
  94 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
  95
  96 /* Do not use these with a slab allocator */
  97 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
  98
  99 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 100    platforms, used as appropriate on others */
 101
 102 #define GFP_DMA         __GFP_DMA
 103
 104 /* 4GB DMA on some platforms */
 105 #define GFP_DMA32       __GFP_DMA32
 106
 107 /* Convert GFP flags to their corresponding migrate type */
 108 static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 109 {
 110         WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 111
 112         if (unlikely(page_group_by_mobility_disabled))
 113                 return MIGRATE_UNMOVABLE;
 114
 115         /* Group based on mobility */
 116         return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 117                 ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 118 }
 119
 120 static inline enum zone_type gfp_zone(gfp_t flags)
 121 {
 122         int base = 0;
 123
 124 #ifdef CONFIG_NUMA
 125         if (flags & __GFP_THISNODE)
 126                 base = MAX_NR_ZONES;
 127 #endif
 128
 129 #ifdef CONFIG_ZONE_DMA
 130         if (flags & __GFP_DMA)
 131                 return base + ZONE_DMA;
 132 #endif
 133 #ifdef CONFIG_ZONE_DMA32
 134         if (flags & __GFP_DMA32)
 135                 return base + ZONE_DMA32;
 136 #endif
 137         if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
 138                         (__GFP_HIGHMEM | __GFP_MOVABLE))
 139                 return base + ZONE_MOVABLE;
 140 #ifdef CONFIG_HIGHMEM
 141         if (flags & __GFP_HIGHMEM)
 142                 return base + ZONE_HIGHMEM;
 143 #endif
 144         return base + ZONE_NORMAL;
 145 }
 146
 147 static inline gfp_t set_migrateflags(gfp_t gfp, gfp_t migrate_flags)
 148 {
 149         BUG_ON((gfp & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 150         return (gfp & ~(GFP_MOVABLE_MASK)) | migrate_flags;
 151 }
 152
 153 /*
 154  * There is only one page-allocator function, and two main namespaces to
 155  * it. The alloc_page*() variants return 'struct page *' and as such
 156  * can allocate highmem pages, the *get*page*() variants return
 157  * virtual kernel addresses to the allocated page(s).
 158  */
 159
 160 /*
 161  * We get the zone list from the current node and the gfp_mask.
 162  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 163  *
 164  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 165  * optimized to &contig_page_data at compile-time.
 166  */
 167
 168 #ifndef HAVE_ARCH_FREE_PAGE
 169 static inline void arch_free_page(struct page *page, int order) { }
 170 #endif
 171 #ifndef HAVE_ARCH_ALLOC_PAGE
 172 static inline void arch_alloc_page(struct page *page, int order) { }
 173 #endif
 174
 175 extern struct page *__alloc_pages(gfp_t, unsigned int, struct zonelist *);
 176
 177 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 178                                                 unsigned int order)
 179 {
 180         if (unlikely(order >= MAX_ORDER))
 181                 return NULL;
 182
 183         /* Unknown node is current node */
 184         if (nid < 0)
 185                 nid = numa_node_id();
 186
 187         return __alloc_pages(gfp_mask, order,
 188                 NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
 189 }
 190
 191 #ifdef CONFIG_NUMA
 192 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 193
 194 static inline struct page *
 195 alloc_pages(gfp_t gfp_mask, unsigned int order)
 196 {
 197         if (unlikely(order >= MAX_ORDER))
 198                 return NULL;
 199
 200         return alloc_pages_current(gfp_mask, order);
 201 }
 202 extern struct page *alloc_page_vma(gfp_t gfp_mask,
 203                         struct vm_area_struct *vma, unsigned long addr);
 204 #else
 205 #define alloc_pages(gfp_mask, order) \
 206                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 207 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 208 #endif
 209 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 210
 211 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 212 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 213
 214 #define __get_free_page(gfp_mask) \
 215                 __get_free_pages((gfp_mask),0)
 216
 217 #define __get_dma_pages(gfp_mask, order) \
 218                 __get_free_pages((gfp_mask) | GFP_DMA,(order))
 219
 220 extern void __free_pages(struct page *page, unsigned int order);
 221 extern void free_pages(unsigned long addr, unsigned int order);
 222 extern void free_hot_page(struct page *page);
 223 extern void free_cold_page(struct page *page);
 224
 225 #define __free_page(page) __free_pages((page), 0)
 226 #define free_page(addr) free_pages((addr),0)
 227
 228 void page_alloc_init(void);
 229 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 230 void drain_all_pages(void);
 231 void drain_local_pages(void *dummy);
 232
 233 #endif /* __LINUX_GFP_H */