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 #include <linux/mmdebug.h>
   9
  10 struct vm_area_struct;
  11
  12 /*
  13  * GFP bitmasks..
  14  *
  15  * Zone modifiers (see linux/mmzone.h - low three bits)
  16  *
  17  * Do not put any conditional on these. If necessary modify the definitions
  18  * without the underscores and use the consistently. The definitions here may
  19  * be used in bit comparisons.
  20  */
  21 #define __GFP_DMA       ((__force gfp_t)0x01u)
  22 #define __GFP_HIGHMEM   ((__force gfp_t)0x02u)
  23 #define __GFP_DMA32     ((__force gfp_t)0x04u)
  24 #define __GFP_MOVABLE   ((__force gfp_t)0x08u)  /* Page is movable */
  25 #define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
  26 /*
  27  * Action modifiers - doesn't change the zoning
  28  *
  29  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  30  * _might_ fail.  This depends upon the particular VM implementation.
  31  *
  32  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  33  * cannot handle allocation failures.  This modifier is deprecated and no new
  34  * users should be added.
  35  *
  36  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  37  *
  38  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  39  * mechanism or reclaimed
  40  */
  41 #define __GFP_WAIT      ((__force gfp_t)0x10u)  /* Can wait and reschedule? */
  42 #define __GFP_HIGH      ((__force gfp_t)0x20u)  /* Should access emergency pools? */
  43 #define __GFP_IO        ((__force gfp_t)0x40u)  /* Can start physical IO? */
  44 #define __GFP_FS        ((__force gfp_t)0x80u)  /* Can call down to low-level FS? */
  45 #define __GFP_COLD      ((__force gfp_t)0x100u) /* Cache-cold page required */
  46 #define __GFP_NOWARN    ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
  47 #define __GFP_REPEAT    ((__force gfp_t)0x400u) /* See above */
  48 #define __GFP_NOFAIL    ((__force gfp_t)0x800u) /* See above */
  49 #define __GFP_NORETRY   ((__force gfp_t)0x1000u)/* See above */
  50 #define __GFP_COMP      ((__force gfp_t)0x4000u)/* Add compound page metadata */
  51 #define __GFP_ZERO      ((__force gfp_t)0x8000u)/* Return zeroed page on success */
  52 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
  53 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
  54 #define __GFP_THISNODE  ((__force gfp_t)0x40000u)/* No fallback, no policies */
  55 #define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */
  56
  57 #ifdef CONFIG_KMEMCHECK
  58 #define __GFP_NOTRACK   ((__force gfp_t)0x200000u)  /* Don't track with kmemcheck */
  59 #else
  60 #define __GFP_NOTRACK   ((__force gfp_t)0)
  61 #endif
  62
  63 /*
  64  * This may seem redundant, but it's a way of annotating false positives vs.
  65  * allocations that simply cannot be supported (e.g. page tables).
  66  */
  67 #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
  68
  69 #define __GFP_BITS_SHIFT 22     /* Room for 22 __GFP_FOO bits */
  70 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  71
  72 /* This equals 0, but use constants in case they ever change */
  73 #define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
  74 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
  75 #define GFP_ATOMIC      (__GFP_HIGH)
  76 #define GFP_NOIO        (__GFP_WAIT)
  77 #define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
  78 #define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
  79 #define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  80                          __GFP_RECLAIMABLE)
  81 #define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
  82 #define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
  83                          __GFP_HIGHMEM)
  84 #define GFP_HIGHUSER_MOVABLE    (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  85                                  __GFP_HARDWALL | __GFP_HIGHMEM | \
  86                                  __GFP_MOVABLE)
  87 #define GFP_IOFS        (__GFP_IO | __GFP_FS)
  88
  89 #ifdef CONFIG_NUMA
  90 #define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  91 #else
  92 #define GFP_THISNODE    ((__force gfp_t)0)
  93 #endif
  94
  95 /* This mask makes up all the page movable related flags */
  96 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
  97
  98 /* Control page allocator reclaim behavior */
  99 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
 100                         __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
 101                         __GFP_NORETRY|__GFP_NOMEMALLOC)
 102
 103 /* Control slab gfp mask during early boot */
 104 #define GFP_BOOT_MASK __GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS)
 105
 106 /* Control allocation constraints */
 107 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
 108
 109 /* Do not use these with a slab allocator */
 110 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
 111
 112 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 113    platforms, used as appropriate on others */
 114
 115 #define GFP_DMA         __GFP_DMA
 116
 117 /* 4GB DMA on some platforms */
 118 #define GFP_DMA32       __GFP_DMA32
 119
 120 /* Convert GFP flags to their corresponding migrate type */
 121 static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 122 {
 123         WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 124
 125         if (unlikely(page_group_by_mobility_disabled))
 126                 return MIGRATE_UNMOVABLE;
 127
 128         /* Group based on mobility */
 129         return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 130                 ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 131 }
 132
 133 #ifdef CONFIG_HIGHMEM
 134 #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
 135 #else
 136 #define OPT_ZONE_HIGHMEM ZONE_NORMAL
 137 #endif
 138
 139 #ifdef CONFIG_ZONE_DMA
 140 #define OPT_ZONE_DMA ZONE_DMA
 141 #else
 142 #define OPT_ZONE_DMA ZONE_NORMAL
 143 #endif
 144
 145 #ifdef CONFIG_ZONE_DMA32
 146 #define OPT_ZONE_DMA32 ZONE_DMA32
 147 #else
 148 #define OPT_ZONE_DMA32 ZONE_NORMAL
 149 #endif
 150
 151 /*
 152  * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
 153  * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
 154  * and there are 16 of them to cover all possible combinations of
 155  * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM
 156  *
 157  * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
 158  * But GFP_MOVABLE is not only a zone specifier but also an allocation
 159  * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
 160  * Only 1bit of the lowest 3 bit (DMA,DMA32,HIGHMEM) can be set to "1".
 161  *
 162  *       bit       result
 163  *       =================
 164  *       0x0    => NORMAL
 165  *       0x1    => DMA or NORMAL
 166  *       0x2    => HIGHMEM or NORMAL
 167  *       0x3    => BAD (DMA+HIGHMEM)
 168  *       0x4    => DMA32 or DMA or NORMAL
 169  *       0x5    => BAD (DMA+DMA32)
 170  *       0x6    => BAD (HIGHMEM+DMA32)
 171  *       0x7    => BAD (HIGHMEM+DMA32+DMA)
 172  *       0x8    => NORMAL (MOVABLE+0)
 173  *       0x9    => DMA or NORMAL (MOVABLE+DMA)
 174  *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
 175  *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
 176  *       0xc    => DMA32 (MOVABLE+HIGHMEM+DMA32)
 177  *       0xd    => BAD (MOVABLE+DMA32+DMA)
 178  *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
 179  *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
 180  *
 181  * ZONES_SHIFT must be <= 2 on 32 bit platforms.
 182  */
 183
 184 #if 16 * ZONES_SHIFT > BITS_PER_LONG
 185 #error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
 186 #endif
 187
 188 #define GFP_ZONE_TABLE ( \
 189         (ZONE_NORMAL << 0 * ZONES_SHIFT)                                \
 190         | (OPT_ZONE_DMA << __GFP_DMA * ZONES_SHIFT)                     \
 191         | (OPT_ZONE_HIGHMEM << __GFP_HIGHMEM * ZONES_SHIFT)             \
 192         | (OPT_ZONE_DMA32 << __GFP_DMA32 * ZONES_SHIFT)                 \
 193         | (ZONE_NORMAL << __GFP_MOVABLE * ZONES_SHIFT)                  \
 194         | (OPT_ZONE_DMA << (__GFP_MOVABLE | __GFP_DMA) * ZONES_SHIFT)   \
 195         | (ZONE_MOVABLE << (__GFP_MOVABLE | __GFP_HIGHMEM) * ZONES_SHIFT)\
 196         | (OPT_ZONE_DMA32 << (__GFP_MOVABLE | __GFP_DMA32) * ZONES_SHIFT)\
 197 )
 198
 199 /*
 200  * GFP_ZONE_BAD is a bitmap for all combination of __GFP_DMA, __GFP_DMA32
 201  * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
 202  * entry starting with bit 0. Bit is set if the combination is not
 203  * allowed.
 204  */
 205 #define GFP_ZONE_BAD ( \
 206         1 << (__GFP_DMA | __GFP_HIGHMEM)                                \
 207         | 1 << (__GFP_DMA | __GFP_DMA32)                                \
 208         | 1 << (__GFP_DMA32 | __GFP_HIGHMEM)                            \
 209         | 1 << (__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM)                \
 210         | 1 << (__GFP_MOVABLE | __GFP_HIGHMEM | __GFP_DMA)              \
 211         | 1 << (__GFP_MOVABLE | __GFP_DMA32 | __GFP_DMA)                \
 212         | 1 << (__GFP_MOVABLE | __GFP_DMA32 | __GFP_HIGHMEM)            \
 213         | 1 << (__GFP_MOVABLE | __GFP_DMA32 | __GFP_DMA | __GFP_HIGHMEM)\
 214 )
 215
 216 static inline enum zone_type gfp_zone(gfp_t flags)
 217 {
 218         enum zone_type z;
 219         int bit = flags & GFP_ZONEMASK;
 220
 221         z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) &
 222                                          ((1 << ZONES_SHIFT) - 1);
 223
 224         if (__builtin_constant_p(bit))
 225                 MAYBE_BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 226         else {
 227 #ifdef CONFIG_DEBUG_VM
 228                 BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 229 #endif
 230         }
 231         return z;
 232 }
 233
 234 /*
 235  * There is only one page-allocator function, and two main namespaces to
 236  * it. The alloc_page*() variants return 'struct page *' and as such
 237  * can allocate highmem pages, the *get*page*() variants return
 238  * virtual kernel addresses to the allocated page(s).
 239  */
 240
 241 static inline int gfp_zonelist(gfp_t flags)
 242 {
 243         if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
 244                 return 1;
 245
 246         return 0;
 247 }
 248
 249 /*
 250  * We get the zone list from the current node and the gfp_mask.
 251  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 252  * There are two zonelists per node, one for all zones with memory and
 253  * one containing just zones from the node the zonelist belongs to.
 254  *
 255  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 256  * optimized to &contig_page_data at compile-time.
 257  */
 258 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 259 {
 260         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 261 }
 262
 263 #ifndef HAVE_ARCH_FREE_PAGE
 264 static inline void arch_free_page(struct page *page, int order) { }
 265 #endif
 266 #ifndef HAVE_ARCH_ALLOC_PAGE
 267 static inline void arch_alloc_page(struct page *page, int order) { }
 268 #endif
 269
 270 struct page *
 271 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 272                        struct zonelist *zonelist, nodemask_t *nodemask);
 273
 274 static inline struct page *
 275 __alloc_pages(gfp_t gfp_mask, unsigned int order,
 276                 struct zonelist *zonelist)
 277 {
 278         return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
 279 }
 280
 281 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 282                                                 unsigned int order)
 283 {
 284         /* Unknown node is current node */
 285         if (nid < 0)
 286                 nid = numa_node_id();
 287
 288         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 289 }
 290
 291 static inline struct page *alloc_pages_exact_node(int nid, gfp_t gfp_mask,
 292                                                 unsigned int order)
 293 {
 294         VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
 295
 296         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 297 }
 298
 299 #ifdef CONFIG_NUMA
 300 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 301
 302 static inline struct page *
 303 alloc_pages(gfp_t gfp_mask, unsigned int order)
 304 {
 305         return alloc_pages_current(gfp_mask, order);
 306 }
 307 extern struct page *alloc_page_vma(gfp_t gfp_mask,
 308                         struct vm_area_struct *vma, unsigned long addr);
 309 #else
 310 #define alloc_pages(gfp_mask, order) \
 311                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 312 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 313 #endif
 314 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 315
 316 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 317 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 318
 319 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 320 void free_pages_exact(void *virt, size_t size);
 321
 322 #define __get_free_page(gfp_mask) \
 323                 __get_free_pages((gfp_mask),0)
 324
 325 #define __get_dma_pages(gfp_mask, order) \
 326                 __get_free_pages((gfp_mask) | GFP_DMA,(order))
 327
 328 extern void __free_pages(struct page *page, unsigned int order);
 329 extern void free_pages(unsigned long addr, unsigned int order);
 330 extern void free_hot_cold_page(struct page *page, int cold);
 331
 332 #define __free_page(page) __free_pages((page), 0)
 333 #define free_page(addr) free_pages((addr),0)
 334
 335 void page_alloc_init(void);
 336 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 337 void drain_all_pages(void);
 338 void drain_local_pages(void *dummy);
 339
 340 extern gfp_t gfp_allowed_mask;
 341
 342 extern void set_gfp_allowed_mask(gfp_t mask);
 343 extern gfp_t clear_gfp_allowed_mask(gfp_t mask);
 344
 345 #endif /* __LINUX_GFP_H */