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) /* See above */
  44 #define __GFP_NOFAIL    ((__force gfp_t)0x800u) /* See above */
  45 #define __GFP_NORETRY   ((__force gfp_t)0x1000u)/* See above */
  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 #ifdef CONFIG_ZONE_DMA
 123         if (flags & __GFP_DMA)
 124                 return ZONE_DMA;
 125 #endif
 126 #ifdef CONFIG_ZONE_DMA32
 127         if (flags & __GFP_DMA32)
 128                 return ZONE_DMA32;
 129 #endif
 130         if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
 131                         (__GFP_HIGHMEM | __GFP_MOVABLE))
 132                 return ZONE_MOVABLE;
 133 #ifdef CONFIG_HIGHMEM
 134         if (flags & __GFP_HIGHMEM)
 135                 return ZONE_HIGHMEM;
 136 #endif
 137         return ZONE_NORMAL;
 138 }
 139
 140 /*
 141  * There is only one page-allocator function, and two main namespaces to
 142  * it. The alloc_page*() variants return 'struct page *' and as such
 143  * can allocate highmem pages, the *get*page*() variants return
 144  * virtual kernel addresses to the allocated page(s).
 145  */
 146
 147 static inline int gfp_zonelist(gfp_t flags)
 148 {
 149         if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
 150                 return 1;
 151
 152         return 0;
 153 }
 154
 155 /*
 156  * We get the zone list from the current node and the gfp_mask.
 157  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 158  * There are two zonelists per node, one for all zones with memory and
 159  * one containing just zones from the node the zonelist belongs to.
 160  *
 161  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 162  * optimized to &contig_page_data at compile-time.
 163  */
 164 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 165 {
 166         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 167 }
 168
 169 #ifndef HAVE_ARCH_FREE_PAGE
 170 static inline void arch_free_page(struct page *page, int order) { }
 171 #endif
 172 #ifndef HAVE_ARCH_ALLOC_PAGE
 173 static inline void arch_alloc_page(struct page *page, int order) { }
 174 #endif
 175
 176 struct page *
 177 __alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
 178                        struct zonelist *zonelist, nodemask_t *nodemask);
 179
 180 static inline struct page *
 181 __alloc_pages(gfp_t gfp_mask, unsigned int order,
 182                 struct zonelist *zonelist)
 183 {
 184         return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
 185 }
 186
 187 static inline struct page *
 188 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 189                 struct zonelist *zonelist, nodemask_t *nodemask)
 190 {
 191         return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
 192 }
 193
 194
 195 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 196                                                 unsigned int order)
 197 {
 198         if (unlikely(order >= MAX_ORDER))
 199                 return NULL;
 200
 201         /* Unknown node is current node */
 202         if (nid < 0)
 203                 nid = numa_node_id();
 204
 205         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 206 }
 207
 208 #ifdef CONFIG_NUMA
 209 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 210
 211 static inline struct page *
 212 alloc_pages(gfp_t gfp_mask, unsigned int order)
 213 {
 214         if (unlikely(order >= MAX_ORDER))
 215                 return NULL;
 216
 217         return alloc_pages_current(gfp_mask, order);
 218 }
 219 extern struct page *alloc_page_vma(gfp_t gfp_mask,
 220                         struct vm_area_struct *vma, unsigned long addr);
 221 #else
 222 #define alloc_pages(gfp_mask, order) \
 223                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 224 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 225 #endif
 226 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 227
 228 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 229 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 230
 231 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 232 void free_pages_exact(void *virt, size_t size);
 233
 234 #define __get_free_page(gfp_mask) \
 235                 __get_free_pages((gfp_mask),0)
 236
 237 #define __get_dma_pages(gfp_mask, order) \
 238                 __get_free_pages((gfp_mask) | GFP_DMA,(order))
 239
 240 extern void __free_pages(struct page *page, unsigned int order);
 241 extern void free_pages(unsigned long addr, unsigned int order);
 242 extern void free_hot_page(struct page *page);
 243 extern void free_cold_page(struct page *page);
 244
 245 #define __free_page(page) __free_pages((page), 0)
 246 #define free_page(addr) free_pages((addr),0)
 247
 248 void page_alloc_init(void);
 249 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 250 void drain_all_pages(void);
 251 void drain_local_pages(void *dummy);
 252
 253 #endif /* __LINUX_GFP_H */