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 #include <linux/topology.h>
   8
   9 struct vm_area_struct;
  10
  11 /*
  12  * GFP bitmasks..
  13  *
  14  * Zone modifiers (see linux/mmzone.h - low three bits)
  15  *
  16  * Do not put any conditional on these. If necessary modify the definitions
  17  * without the underscores and use the consistently. The definitions here may
  18  * be used in bit comparisons.
  19  */
  20 #define __GFP_DMA       ((__force gfp_t)0x01u)
  21 #define __GFP_HIGHMEM   ((__force gfp_t)0x02u)
  22 #define __GFP_DMA32     ((__force gfp_t)0x04u)
  23
  24 /*
  25  * Action modifiers - doesn't change the zoning
  26  *
  27  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  28  * _might_ fail.  This depends upon the particular VM implementation.
  29  *
  30  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  31  * cannot handle allocation failures.
  32  *
  33  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  34  *
  35  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  36  * mechanism or reclaimed
  37  */
  38 #define __GFP_WAIT      ((__force gfp_t)0x10u)  /* Can wait and reschedule? */
  39 #define __GFP_HIGH      ((__force gfp_t)0x20u)  /* Should access emergency pools? */
  40 #define __GFP_IO        ((__force gfp_t)0x40u)  /* Can start physical IO? */
  41 #define __GFP_FS        ((__force gfp_t)0x80u)  /* Can call down to low-level FS? */
  42 #define __GFP_COLD      ((__force gfp_t)0x100u) /* Cache-cold page required */
  43 #define __GFP_NOWARN    ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
  44 #define __GFP_REPEAT    ((__force gfp_t)0x400u) /* See above */
  45 #define __GFP_NOFAIL    ((__force gfp_t)0x800u) /* See above */
  46 #define __GFP_NORETRY   ((__force gfp_t)0x1000u)/* See above */
  47 #define __GFP_COMP      ((__force gfp_t)0x4000u)/* Add compound page metadata */
  48 #define __GFP_ZERO      ((__force gfp_t)0x8000u)/* Return zeroed page on success */
  49 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
  50 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
  51 #define __GFP_THISNODE  ((__force gfp_t)0x40000u)/* No fallback, no policies */
  52 #define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */
  53 #define __GFP_MOVABLE   ((__force gfp_t)0x100000u)  /* Page is movable */
  54
  55 #ifdef CONFIG_KMEMCHECK
  56 #define __GFP_NOTRACK   ((__force gfp_t)0x200000u)  /* Don't track with kmemcheck */
  57 #else
  58 #define __GFP_NOTRACK   ((__force gfp_t)0)
  59 #endif
  60
  61 /*
  62  * This may seem redundant, but it's a way of annotating false positives vs.
  63  * allocations that simply cannot be supported (e.g. page tables).
  64  */
  65 #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
  66
  67 #define __GFP_BITS_SHIFT 22     /* Room for 22 __GFP_FOO bits */
  68 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  69
  70 /* This equals 0, but use constants in case they ever change */
  71 #define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
  72 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
  73 #define GFP_ATOMIC      (__GFP_HIGH)
  74 #define GFP_NOIO        (__GFP_WAIT)
  75 #define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
  76 #define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
  77 #define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  78                          __GFP_RECLAIMABLE)
  79 #define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
  80 #define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
  81                          __GFP_HIGHMEM)
  82 #define GFP_HIGHUSER_MOVABLE    (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  83                                  __GFP_HARDWALL | __GFP_HIGHMEM | \
  84                                  __GFP_MOVABLE)
  85
  86 #ifdef CONFIG_NUMA
  87 #define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  88 #else
  89 #define GFP_THISNODE    ((__force gfp_t)0)
  90 #endif
  91
  92 /* This mask makes up all the page movable related flags */
  93 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
  94
  95 /* Control page allocator reclaim behavior */
  96 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
  97                         __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
  98                         __GFP_NORETRY|__GFP_NOMEMALLOC)
  99
 100 /* Control allocation constraints */
 101 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
 102
 103 /* Do not use these with a slab allocator */
 104 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
 105
 106 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 107    platforms, used as appropriate on others */
 108
 109 #define GFP_DMA         __GFP_DMA
 110
 111 /* 4GB DMA on some platforms */
 112 #define GFP_DMA32       __GFP_DMA32
 113
 114 /* Convert GFP flags to their corresponding migrate type */
 115 static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 116 {
 117         WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 118
 119         if (unlikely(page_group_by_mobility_disabled))
 120                 return MIGRATE_UNMOVABLE;
 121
 122         /* Group based on mobility */
 123         return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 124                 ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 125 }
 126
 127 static inline enum zone_type gfp_zone(gfp_t flags)
 128 {
 129 #ifdef CONFIG_ZONE_DMA
 130         if (flags & __GFP_DMA)
 131                 return ZONE_DMA;
 132 #endif
 133 #ifdef CONFIG_ZONE_DMA32
 134         if (flags & __GFP_DMA32)
 135                 return ZONE_DMA32;
 136 #endif
 137         if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
 138                         (__GFP_HIGHMEM | __GFP_MOVABLE))
 139                 return ZONE_MOVABLE;
 140 #ifdef CONFIG_HIGHMEM
 141         if (flags & __GFP_HIGHMEM)
 142                 return ZONE_HIGHMEM;
 143 #endif
 144         return ZONE_NORMAL;
 145 }
 146
 147 /*
 148  * There is only one page-allocator function, and two main namespaces to
 149  * it. The alloc_page*() variants return 'struct page *' and as such
 150  * can allocate highmem pages, the *get*page*() variants return
 151  * virtual kernel addresses to the allocated page(s).
 152  */
 153
 154 static inline int gfp_zonelist(gfp_t flags)
 155 {
 156         if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
 157                 return 1;
 158
 159         return 0;
 160 }
 161
 162 /*
 163  * We get the zone list from the current node and the gfp_mask.
 164  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 165  * There are two zonelists per node, one for all zones with memory and
 166  * one containing just zones from the node the zonelist belongs to.
 167  *
 168  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 169  * optimized to &contig_page_data at compile-time.
 170  */
 171 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 172 {
 173         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 174 }
 175
 176 #ifndef HAVE_ARCH_FREE_PAGE
 177 static inline void arch_free_page(struct page *page, int order) { }
 178 #endif
 179 #ifndef HAVE_ARCH_ALLOC_PAGE
 180 static inline void arch_alloc_page(struct page *page, int order) { }
 181 #endif
 182
 183 struct page *
 184 __alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
 185                        struct zonelist *zonelist, nodemask_t *nodemask);
 186
 187 static inline struct page *
 188 __alloc_pages(gfp_t gfp_mask, unsigned int order,
 189                 struct zonelist *zonelist)
 190 {
 191         return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
 192 }
 193
 194 static inline struct page *
 195 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 196                 struct zonelist *zonelist, nodemask_t *nodemask)
 197 {
 198         return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
 199 }
 200
 201
 202 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 203                                                 unsigned int order)
 204 {
 205         if (unlikely(order >= MAX_ORDER))
 206                 return NULL;
 207
 208         /* Unknown node is current node */
 209         if (nid < 0)
 210                 nid = numa_node_id();
 211
 212         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 213 }
 214
 215 #ifdef CONFIG_NUMA
 216 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 217
 218 static inline struct page *
 219 alloc_pages(gfp_t gfp_mask, unsigned int order)
 220 {
 221         if (unlikely(order >= MAX_ORDER))
 222                 return NULL;
 223
 224         return alloc_pages_current(gfp_mask, order);
 225 }
 226 extern struct page *alloc_page_vma(gfp_t gfp_mask,
 227                         struct vm_area_struct *vma, unsigned long addr);
 228 #else
 229 #define alloc_pages(gfp_mask, order) \
 230                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 231 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 232 #endif
 233 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 234
 235 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 236 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 237
 238 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 239 void free_pages_exact(void *virt, size_t size);
 240
 241 #define __get_free_page(gfp_mask) \
 242                 __get_free_pages((gfp_mask),0)
 243
 244 #define __get_dma_pages(gfp_mask, order) \
 245                 __get_free_pages((gfp_mask) | GFP_DMA,(order))
 246
 247 extern void __free_pages(struct page *page, unsigned int order);
 248 extern void free_pages(unsigned long addr, unsigned int order);
 249 extern void free_hot_page(struct page *page);
 250 extern void free_cold_page(struct page *page);
 251
 252 #define __free_page(page) __free_pages((page), 0)
 253 #define free_page(addr) free_pages((addr),0)
 254
 255 void page_alloc_init(void);
 256 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 257 void drain_all_pages(void);
 258 void drain_local_pages(void *dummy);
 259
 260 #endif /* __LINUX_GFP_H */