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 /* Plain integer GFP bitmasks. Do not use this directly. */
  13 #define ___GFP_DMA              0x01u
  14 #define ___GFP_HIGHMEM          0x02u
  15 #define ___GFP_DMA32            0x04u
  16 #define ___GFP_MOVABLE          0x08u
  17 #define ___GFP_WAIT             0x10u
  18 #define ___GFP_HIGH             0x20u
  19 #define ___GFP_IO               0x40u
  20 #define ___GFP_FS               0x80u
  21 #define ___GFP_COLD             0x100u
  22 #define ___GFP_NOWARN           0x200u
  23 #define ___GFP_REPEAT           0x400u
  24 #define ___GFP_NOFAIL           0x800u
  25 #define ___GFP_NORETRY          0x1000u
  26 #define ___GFP_COMP             0x4000u
  27 #define ___GFP_ZERO             0x8000u
  28 #define ___GFP_NOMEMALLOC       0x10000u
  29 #define ___GFP_HARDWALL         0x20000u
  30 #define ___GFP_THISNODE         0x40000u
  31 #define ___GFP_RECLAIMABLE      0x80000u
  32 #ifdef CONFIG_KMEMCHECK
  33 #define ___GFP_NOTRACK          0x200000u
  34 #else
  35 #define ___GFP_NOTRACK          0
  36 #endif
  37
  38 /*
  39  * GFP bitmasks..
  40  *
  41  * Zone modifiers (see linux/mmzone.h - low three bits)
  42  *
  43  * Do not put any conditional on these. If necessary modify the definitions
  44  * without the underscores and use them consistently. The definitions here may
  45  * be used in bit comparisons.
  46  */
  47 #define __GFP_DMA       ((__force gfp_t)___GFP_DMA)
  48 #define __GFP_HIGHMEM   ((__force gfp_t)___GFP_HIGHMEM)
  49 #define __GFP_DMA32     ((__force gfp_t)___GFP_DMA32)
  50 #define __GFP_MOVABLE   ((__force gfp_t)___GFP_MOVABLE)  /* Page is movable */
  51 #define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
  52 /*
  53  * Action modifiers - doesn't change the zoning
  54  *
  55  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  56  * _might_ fail.  This depends upon the particular VM implementation.
  57  *
  58  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  59  * cannot handle allocation failures.  This modifier is deprecated and no new
  60  * users should be added.
  61  *
  62  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  63  *
  64  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  65  * mechanism or reclaimed
  66  */
  67 #define __GFP_WAIT      ((__force gfp_t)___GFP_WAIT)    /* Can wait and reschedule? */
  68 #define __GFP_HIGH      ((__force gfp_t)___GFP_HIGH)    /* Should access emergency pools? */
  69 #define __GFP_IO        ((__force gfp_t)___GFP_IO)      /* Can start physical IO? */
  70 #define __GFP_FS        ((__force gfp_t)___GFP_FS)      /* Can call down to low-level FS? */
  71 #define __GFP_COLD      ((__force gfp_t)___GFP_COLD)    /* Cache-cold page required */
  72 #define __GFP_NOWARN    ((__force gfp_t)___GFP_NOWARN)  /* Suppress page allocation failure warning */
  73 #define __GFP_REPEAT    ((__force gfp_t)___GFP_REPEAT)  /* See above */
  74 #define __GFP_NOFAIL    ((__force gfp_t)___GFP_NOFAIL)  /* See above */
  75 #define __GFP_NORETRY   ((__force gfp_t)___GFP_NORETRY) /* See above */
  76 #define __GFP_COMP      ((__force gfp_t)___GFP_COMP)    /* Add compound page metadata */
  77 #define __GFP_ZERO      ((__force gfp_t)___GFP_ZERO)    /* Return zeroed page on success */
  78 #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC) /* Don't use emergency reserves */
  79 #define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL) /* Enforce hardwall cpuset memory allocs */
  80 #define __GFP_THISNODE  ((__force gfp_t)___GFP_THISNODE)/* No fallback, no policies */
  81 #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) /* Page is reclaimable */
  82 #define __GFP_NOTRACK   ((__force gfp_t)___GFP_NOTRACK)  /* Don't track with kmemcheck */
  83
  84 /*
  85  * This may seem redundant, but it's a way of annotating false positives vs.
  86  * allocations that simply cannot be supported (e.g. page tables).
  87  */
  88 #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
  89
  90 #define __GFP_BITS_SHIFT 22     /* Room for 22 __GFP_FOO bits */
  91 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  92
  93 /* This equals 0, but use constants in case they ever change */
  94 #define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
  95 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
  96 #define GFP_ATOMIC      (__GFP_HIGH)
  97 #define GFP_NOIO        (__GFP_WAIT)
  98 #define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
  99 #define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
 100 #define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
 101                          __GFP_RECLAIMABLE)
 102 #define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
 103 #define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
 104                          __GFP_HIGHMEM)
 105 #define GFP_HIGHUSER_MOVABLE    (__GFP_WAIT | __GFP_IO | __GFP_FS | \
 106                                  __GFP_HARDWALL | __GFP_HIGHMEM | \
 107                                  __GFP_MOVABLE)
 108 #define GFP_IOFS        (__GFP_IO | __GFP_FS)
 109
 110 #ifdef CONFIG_NUMA
 111 #define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
 112 #else
 113 #define GFP_THISNODE    ((__force gfp_t)0)
 114 #endif
 115
 116 /* This mask makes up all the page movable related flags */
 117 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
 118
 119 /* Control page allocator reclaim behavior */
 120 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
 121                         __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
 122                         __GFP_NORETRY|__GFP_NOMEMALLOC)
 123
 124 /* Control slab gfp mask during early boot */
 125 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS))
 126
 127 /* Control allocation constraints */
 128 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
 129
 130 /* Do not use these with a slab allocator */
 131 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
 132
 133 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 134    platforms, used as appropriate on others */
 135
 136 #define GFP_DMA         __GFP_DMA
 137
 138 /* 4GB DMA on some platforms */
 139 #define GFP_DMA32       __GFP_DMA32
 140
 141 /* Convert GFP flags to their corresponding migrate type */
 142 static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 143 {
 144         WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 145
 146         if (unlikely(page_group_by_mobility_disabled))
 147                 return MIGRATE_UNMOVABLE;
 148
 149         /* Group based on mobility */
 150         return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 151                 ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 152 }
 153
 154 #ifdef CONFIG_HIGHMEM
 155 #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
 156 #else
 157 #define OPT_ZONE_HIGHMEM ZONE_NORMAL
 158 #endif
 159
 160 #ifdef CONFIG_ZONE_DMA
 161 #define OPT_ZONE_DMA ZONE_DMA
 162 #else
 163 #define OPT_ZONE_DMA ZONE_NORMAL
 164 #endif
 165
 166 #ifdef CONFIG_ZONE_DMA32
 167 #define OPT_ZONE_DMA32 ZONE_DMA32
 168 #else
 169 #define OPT_ZONE_DMA32 ZONE_NORMAL
 170 #endif
 171
 172 /*
 173  * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
 174  * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
 175  * and there are 16 of them to cover all possible combinations of
 176  * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
 177  *
 178  * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
 179  * But GFP_MOVABLE is not only a zone specifier but also an allocation
 180  * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
 181  * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
 182  *
 183  *       bit       result
 184  *       =================
 185  *       0x0    => NORMAL
 186  *       0x1    => DMA or NORMAL
 187  *       0x2    => HIGHMEM or NORMAL
 188  *       0x3    => BAD (DMA+HIGHMEM)
 189  *       0x4    => DMA32 or DMA or NORMAL
 190  *       0x5    => BAD (DMA+DMA32)
 191  *       0x6    => BAD (HIGHMEM+DMA32)
 192  *       0x7    => BAD (HIGHMEM+DMA32+DMA)
 193  *       0x8    => NORMAL (MOVABLE+0)
 194  *       0x9    => DMA or NORMAL (MOVABLE+DMA)
 195  *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
 196  *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
 197  *       0xc    => DMA32 (MOVABLE+HIGHMEM+DMA32)
 198  *       0xd    => BAD (MOVABLE+DMA32+DMA)
 199  *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
 200  *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
 201  *
 202  * ZONES_SHIFT must be <= 2 on 32 bit platforms.
 203  */
 204
 205 #if 16 * ZONES_SHIFT > BITS_PER_LONG
 206 #error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
 207 #endif
 208
 209 #define GFP_ZONE_TABLE ( \
 210         (ZONE_NORMAL << 0 * ZONES_SHIFT)                                      \
 211         | (OPT_ZONE_DMA << ___GFP_DMA * ZONES_SHIFT)                          \
 212         | (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * ZONES_SHIFT)                  \
 213         | (OPT_ZONE_DMA32 << ___GFP_DMA32 * ZONES_SHIFT)                      \
 214         | (ZONE_NORMAL << ___GFP_MOVABLE * ZONES_SHIFT)                       \
 215         | (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * ZONES_SHIFT)       \
 216         | (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * ZONES_SHIFT)   \
 217         | (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * ZONES_SHIFT)   \
 218 )
 219
 220 /*
 221  * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
 222  * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
 223  * entry starting with bit 0. Bit is set if the combination is not
 224  * allowed.
 225  */
 226 #define GFP_ZONE_BAD ( \
 227         1 << (___GFP_DMA | ___GFP_HIGHMEM)                                    \
 228         | 1 << (___GFP_DMA | ___GFP_DMA32)                                    \
 229         | 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)                                \
 230         | 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)                   \
 231         | 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)                 \
 232         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)                   \
 233         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)               \
 234         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
 235 )
 236
 237 static inline enum zone_type gfp_zone(gfp_t flags)
 238 {
 239         enum zone_type z;
 240         int bit = (__force int) (flags & GFP_ZONEMASK);
 241
 242         z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) &
 243                                          ((1 << ZONES_SHIFT) - 1);
 244
 245         if (__builtin_constant_p(bit))
 246                 MAYBE_BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 247         else {
 248 #ifdef CONFIG_DEBUG_VM
 249                 BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 250 #endif
 251         }
 252         return z;
 253 }
 254
 255 /*
 256  * There is only one page-allocator function, and two main namespaces to
 257  * it. The alloc_page*() variants return 'struct page *' and as such
 258  * can allocate highmem pages, the *get*page*() variants return
 259  * virtual kernel addresses to the allocated page(s).
 260  */
 261
 262 static inline int gfp_zonelist(gfp_t flags)
 263 {
 264         if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
 265                 return 1;
 266
 267         return 0;
 268 }
 269
 270 /*
 271  * We get the zone list from the current node and the gfp_mask.
 272  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 273  * There are two zonelists per node, one for all zones with memory and
 274  * one containing just zones from the node the zonelist belongs to.
 275  *
 276  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 277  * optimized to &contig_page_data at compile-time.
 278  */
 279 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 280 {
 281         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 282 }
 283
 284 #ifndef HAVE_ARCH_FREE_PAGE
 285 static inline void arch_free_page(struct page *page, int order) { }
 286 #endif
 287 #ifndef HAVE_ARCH_ALLOC_PAGE
 288 static inline void arch_alloc_page(struct page *page, int order) { }
 289 #endif
 290
 291 struct page *
 292 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 293                        struct zonelist *zonelist, nodemask_t *nodemask);
 294
 295 static inline struct page *
 296 __alloc_pages(gfp_t gfp_mask, unsigned int order,
 297                 struct zonelist *zonelist)
 298 {
 299         return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
 300 }
 301
 302 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 303                                                 unsigned int order)
 304 {
 305         /* Unknown node is current node */
 306         if (nid < 0)
 307                 nid = numa_node_id();
 308
 309         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 310 }
 311
 312 static inline struct page *alloc_pages_exact_node(int nid, gfp_t gfp_mask,
 313                                                 unsigned int order)
 314 {
 315         VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
 316
 317         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 318 }
 319
 320 #ifdef CONFIG_NUMA
 321 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 322
 323 static inline struct page *
 324 alloc_pages(gfp_t gfp_mask, unsigned int order)
 325 {
 326         return alloc_pages_current(gfp_mask, order);
 327 }
 328 extern struct page *alloc_page_vma(gfp_t gfp_mask,
 329                         struct vm_area_struct *vma, unsigned long addr);
 330 #else
 331 #define alloc_pages(gfp_mask, order) \
 332                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 333 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 334 #endif
 335 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 336
 337 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 338 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 339
 340 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 341 void free_pages_exact(void *virt, size_t size);
 342
 343 #define __get_free_page(gfp_mask) \
 344                 __get_free_pages((gfp_mask), 0)
 345
 346 #define __get_dma_pages(gfp_mask, order) \
 347                 __get_free_pages((gfp_mask) | GFP_DMA, (order))
 348
 349 extern void __free_pages(struct page *page, unsigned int order);
 350 extern void free_pages(unsigned long addr, unsigned int order);
 351 extern void free_hot_cold_page(struct page *page, int cold);
 352
 353 #define __free_page(page) __free_pages((page), 0)
 354 #define free_page(addr) free_pages((addr), 0)
 355
 356 void page_alloc_init(void);
 357 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 358 void drain_all_pages(void);
 359 void drain_local_pages(void *dummy);
 360
 361 extern gfp_t gfp_allowed_mask;
 362
 363 extern void set_gfp_allowed_mask(gfp_t mask);
 364 extern gfp_t clear_gfp_allowed_mask(gfp_t mask);
 365
 366 #endif /* __LINUX_GFP_H */