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 #define __GFP_BITS_SHIFT 21     /* Room for 21 __GFP_FOO bits */
  56 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  57
  58 /* This equals 0, but use constants in case they ever change */
  59 #define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
  60 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
  61 #define GFP_ATOMIC      (__GFP_HIGH)
  62 #define GFP_NOIO        (__GFP_WAIT)
  63 #define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
  64 #define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
  65 #define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  66                          __GFP_RECLAIMABLE)
  67 #define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
  68 #define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
  69                          __GFP_HIGHMEM)
  70 #define GFP_HIGHUSER_MOVABLE    (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  71                                  __GFP_HARDWALL | __GFP_HIGHMEM | \
  72                                  __GFP_MOVABLE)
  73
  74 #ifdef CONFIG_NUMA
  75 #define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  76 #else
  77 #define GFP_THISNODE    ((__force gfp_t)0)
  78 #endif
  79
  80 /* This mask makes up all the page movable related flags */
  81 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
  82
  83 /* Control page allocator reclaim behavior */
  84 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
  85                         __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
  86                         __GFP_NORETRY|__GFP_NOMEMALLOC)
  87
  88 /* Control allocation constraints */
  89 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
  90
  91 /* Do not use these with a slab allocator */
  92 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
  93
  94 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
  95    platforms, used as appropriate on others */
  96
  97 #define GFP_DMA         __GFP_DMA
  98
  99 /* 4GB DMA on some platforms */
 100 #define GFP_DMA32       __GFP_DMA32
 101
 102 /* Convert GFP flags to their corresponding migrate type */
 103 static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 104 {
 105         WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 106
 107         if (unlikely(page_group_by_mobility_disabled))
 108                 return MIGRATE_UNMOVABLE;
 109
 110         /* Group based on mobility */
 111         return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 112                 ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 113 }
 114
 115 static inline enum zone_type gfp_zone(gfp_t flags)
 116 {
 117 #ifdef CONFIG_ZONE_DMA
 118         if (flags & __GFP_DMA)
 119                 return ZONE_DMA;
 120 #endif
 121 #ifdef CONFIG_ZONE_DMA32
 122         if (flags & __GFP_DMA32)
 123                 return ZONE_DMA32;
 124 #endif
 125         if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
 126                         (__GFP_HIGHMEM | __GFP_MOVABLE))
 127                 return ZONE_MOVABLE;
 128 #ifdef CONFIG_HIGHMEM
 129         if (flags & __GFP_HIGHMEM)
 130                 return ZONE_HIGHMEM;
 131 #endif
 132         return ZONE_NORMAL;
 133 }
 134
 135 /*
 136  * There is only one page-allocator function, and two main namespaces to
 137  * it. The alloc_page*() variants return 'struct page *' and as such
 138  * can allocate highmem pages, the *get*page*() variants return
 139  * virtual kernel addresses to the allocated page(s).
 140  */
 141
 142 static inline int gfp_zonelist(gfp_t flags)
 143 {
 144         if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
 145                 return 1;
 146
 147         return 0;
 148 }
 149
 150 /*
 151  * We get the zone list from the current node and the gfp_mask.
 152  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 153  * There are two zonelists per node, one for all zones with memory and
 154  * one containing just zones from the node the zonelist belongs to.
 155  *
 156  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 157  * optimized to &contig_page_data at compile-time.
 158  */
 159 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 160 {
 161         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 162 }
 163
 164 #ifndef HAVE_ARCH_FREE_PAGE
 165 static inline void arch_free_page(struct page *page, int order) { }
 166 #endif
 167 #ifndef HAVE_ARCH_ALLOC_PAGE
 168 static inline void arch_alloc_page(struct page *page, int order) { }
 169 #endif
 170
 171 struct page *
 172 __alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
 173                        struct zonelist *zonelist, nodemask_t *nodemask);
 174
 175 static inline struct page *
 176 __alloc_pages(gfp_t gfp_mask, unsigned int order,
 177                 struct zonelist *zonelist)
 178 {
 179         return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
 180 }
 181
 182 static inline struct page *
 183 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 184                 struct zonelist *zonelist, nodemask_t *nodemask)
 185 {
 186         return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
 187 }
 188
 189
 190 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 191                                                 unsigned int order)
 192 {
 193         if (unlikely(order >= MAX_ORDER))
 194                 return NULL;
 195
 196         /* Unknown node is current node */
 197         if (nid < 0)
 198                 nid = numa_node_id();
 199
 200         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 201 }
 202
 203 #ifdef CONFIG_NUMA
 204 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 205
 206 static inline struct page *
 207 alloc_pages(gfp_t gfp_mask, unsigned int order)
 208 {
 209         if (unlikely(order >= MAX_ORDER))
 210                 return NULL;
 211
 212         return alloc_pages_current(gfp_mask, order);
 213 }
 214 extern struct page *alloc_page_vma(gfp_t gfp_mask,
 215                         struct vm_area_struct *vma, unsigned long addr);
 216 #else
 217 #define alloc_pages(gfp_mask, order) \
 218                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 219 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 220 #endif
 221 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 222
 223 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 224 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 225
 226 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 227 void free_pages_exact(void *virt, size_t size);
 228
 229 #define __get_free_page(gfp_mask) \
 230                 __get_free_pages((gfp_mask),0)
 231
 232 #define __get_dma_pages(gfp_mask, order) \
 233                 __get_free_pages((gfp_mask) | GFP_DMA,(order))
 234
 235 extern void __free_pages(struct page *page, unsigned int order);
 236 extern void free_pages(unsigned long addr, unsigned int order);
 237 extern void free_hot_page(struct page *page);
 238 extern void free_cold_page(struct page *page);
 239
 240 #define __free_page(page) __free_pages((page), 0)
 241 #define free_page(addr) free_pages((addr),0)
 242
 243 void page_alloc_init(void);
 244 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 245 void drain_all_pages(void);
 246 void drain_local_pages(void *dummy);
 247
 248 #endif /* __LINUX_GFP_H */