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 #define ___GFP_NO_KSWAPD        0x400000u
  38 #define ___GFP_OTHER_NODE       0x800000u
  39
  40 /*
  41  * GFP bitmasks..
  42  *
  43  * Zone modifiers (see linux/mmzone.h - low three bits)
  44  *
  45  * Do not put any conditional on these. If necessary modify the definitions
  46  * without the underscores and use them consistently. The definitions here may
  47  * be used in bit comparisons.
  48  */
  49 #define __GFP_DMA       ((__force gfp_t)___GFP_DMA)
  50 #define __GFP_HIGHMEM   ((__force gfp_t)___GFP_HIGHMEM)
  51 #define __GFP_DMA32     ((__force gfp_t)___GFP_DMA32)
  52 #define __GFP_MOVABLE   ((__force gfp_t)___GFP_MOVABLE)  /* Page is movable */
  53 #define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
  54 /*
  55  * Action modifiers - doesn't change the zoning
  56  *
  57  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  58  * _might_ fail.  This depends upon the particular VM implementation.
  59  *
  60  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  61  * cannot handle allocation failures.  This modifier is deprecated and no new
  62  * users should be added.
  63  *
  64  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  65  *
  66  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  67  * mechanism or reclaimed
  68  */
  69 #define __GFP_WAIT      ((__force gfp_t)___GFP_WAIT)    /* Can wait and reschedule? */
  70 #define __GFP_HIGH      ((__force gfp_t)___GFP_HIGH)    /* Should access emergency pools? */
  71 #define __GFP_IO        ((__force gfp_t)___GFP_IO)      /* Can start physical IO? */
  72 #define __GFP_FS        ((__force gfp_t)___GFP_FS)      /* Can call down to low-level FS? */
  73 #define __GFP_COLD      ((__force gfp_t)___GFP_COLD)    /* Cache-cold page required */
  74 #define __GFP_NOWARN    ((__force gfp_t)___GFP_NOWARN)  /* Suppress page allocation failure warning */
  75 #define __GFP_REPEAT    ((__force gfp_t)___GFP_REPEAT)  /* See above */
  76 #define __GFP_NOFAIL    ((__force gfp_t)___GFP_NOFAIL)  /* See above */
  77 #define __GFP_NORETRY   ((__force gfp_t)___GFP_NORETRY) /* See above */
  78 #define __GFP_COMP      ((__force gfp_t)___GFP_COMP)    /* Add compound page metadata */
  79 #define __GFP_ZERO      ((__force gfp_t)___GFP_ZERO)    /* Return zeroed page on success */
  80 #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC) /* Don't use emergency reserves */
  81 #define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL) /* Enforce hardwall cpuset memory allocs */
  82 #define __GFP_THISNODE  ((__force gfp_t)___GFP_THISNODE)/* No fallback, no policies */
  83 #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) /* Page is reclaimable */
  84 #define __GFP_NOTRACK   ((__force gfp_t)___GFP_NOTRACK)  /* Don't track with kmemcheck */
  85
  86 #define __GFP_NO_KSWAPD ((__force gfp_t)___GFP_NO_KSWAPD)
  87 #define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE) /* On behalf of other node */
  88
  89 /*
  90  * This may seem redundant, but it's a way of annotating false positives vs.
  91  * allocations that simply cannot be supported (e.g. page tables).
  92  */
  93 #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
  94
  95 #define __GFP_BITS_SHIFT 23     /* Room for 23 __GFP_FOO bits */
  96 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  97
  98 /* This equals 0, but use constants in case they ever change */
  99 #define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
 100 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
 101 #define GFP_ATOMIC      (__GFP_HIGH)
 102 #define GFP_NOIO        (__GFP_WAIT)
 103 #define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
 104 #define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
 105 #define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
 106                          __GFP_RECLAIMABLE)
 107 #define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
 108 #define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
 109                          __GFP_HIGHMEM)
 110 #define GFP_HIGHUSER_MOVABLE    (__GFP_WAIT | __GFP_IO | __GFP_FS | \
 111                                  __GFP_HARDWALL | __GFP_HIGHMEM | \
 112                                  __GFP_MOVABLE)
 113 #define GFP_IOFS        (__GFP_IO | __GFP_FS)
 114 #define GFP_TRANSHUGE   (GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
 115                          __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | \
 116                          __GFP_NO_KSWAPD)
 117
 118 #ifdef CONFIG_NUMA
 119 #define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
 120 #else
 121 #define GFP_THISNODE    ((__force gfp_t)0)
 122 #endif
 123
 124 /* This mask makes up all the page movable related flags */
 125 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
 126
 127 /* Control page allocator reclaim behavior */
 128 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
 129                         __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
 130                         __GFP_NORETRY|__GFP_NOMEMALLOC)
 131
 132 /* Control slab gfp mask during early boot */
 133 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS))
 134
 135 /* Control allocation constraints */
 136 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
 137
 138 /* Do not use these with a slab allocator */
 139 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
 140
 141 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 142    platforms, used as appropriate on others */
 143
 144 #define GFP_DMA         __GFP_DMA
 145
 146 /* 4GB DMA on some platforms */
 147 #define GFP_DMA32       __GFP_DMA32
 148
 149 /* Convert GFP flags to their corresponding migrate type */
 150 static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 151 {
 152         WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 153
 154         if (unlikely(page_group_by_mobility_disabled))
 155                 return MIGRATE_UNMOVABLE;
 156
 157         /* Group based on mobility */
 158         return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 159                 ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 160 }
 161
 162 #ifdef CONFIG_HIGHMEM
 163 #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
 164 #else
 165 #define OPT_ZONE_HIGHMEM ZONE_NORMAL
 166 #endif
 167
 168 #ifdef CONFIG_ZONE_DMA
 169 #define OPT_ZONE_DMA ZONE_DMA
 170 #else
 171 #define OPT_ZONE_DMA ZONE_NORMAL
 172 #endif
 173
 174 #ifdef CONFIG_ZONE_DMA32
 175 #define OPT_ZONE_DMA32 ZONE_DMA32
 176 #else
 177 #define OPT_ZONE_DMA32 ZONE_NORMAL
 178 #endif
 179
 180 /*
 181  * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
 182  * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
 183  * and there are 16 of them to cover all possible combinations of
 184  * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
 185  *
 186  * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
 187  * But GFP_MOVABLE is not only a zone specifier but also an allocation
 188  * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
 189  * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
 190  *
 191  *       bit       result
 192  *       =================
 193  *       0x0    => NORMAL
 194  *       0x1    => DMA or NORMAL
 195  *       0x2    => HIGHMEM or NORMAL
 196  *       0x3    => BAD (DMA+HIGHMEM)
 197  *       0x4    => DMA32 or DMA or NORMAL
 198  *       0x5    => BAD (DMA+DMA32)
 199  *       0x6    => BAD (HIGHMEM+DMA32)
 200  *       0x7    => BAD (HIGHMEM+DMA32+DMA)
 201  *       0x8    => NORMAL (MOVABLE+0)
 202  *       0x9    => DMA or NORMAL (MOVABLE+DMA)
 203  *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
 204  *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
 205  *       0xc    => DMA32 (MOVABLE+HIGHMEM+DMA32)
 206  *       0xd    => BAD (MOVABLE+DMA32+DMA)
 207  *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
 208  *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
 209  *
 210  * ZONES_SHIFT must be <= 2 on 32 bit platforms.
 211  */
 212
 213 #if 16 * ZONES_SHIFT > BITS_PER_LONG
 214 #error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
 215 #endif
 216
 217 #define GFP_ZONE_TABLE ( \
 218         (ZONE_NORMAL << 0 * ZONES_SHIFT)                                      \
 219         | (OPT_ZONE_DMA << ___GFP_DMA * ZONES_SHIFT)                          \
 220         | (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * ZONES_SHIFT)                  \
 221         | (OPT_ZONE_DMA32 << ___GFP_DMA32 * ZONES_SHIFT)                      \
 222         | (ZONE_NORMAL << ___GFP_MOVABLE * ZONES_SHIFT)                       \
 223         | (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * ZONES_SHIFT)       \
 224         | (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * ZONES_SHIFT)   \
 225         | (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * ZONES_SHIFT)   \
 226 )
 227
 228 /*
 229  * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
 230  * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
 231  * entry starting with bit 0. Bit is set if the combination is not
 232  * allowed.
 233  */
 234 #define GFP_ZONE_BAD ( \
 235         1 << (___GFP_DMA | ___GFP_HIGHMEM)                                    \
 236         | 1 << (___GFP_DMA | ___GFP_DMA32)                                    \
 237         | 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)                                \
 238         | 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)                   \
 239         | 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)                 \
 240         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)                   \
 241         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)               \
 242         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
 243 )
 244
 245 static inline enum zone_type gfp_zone(gfp_t flags)
 246 {
 247         enum zone_type z;
 248         int bit = (__force int) (flags & GFP_ZONEMASK);
 249
 250         z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) &
 251                                          ((1 << ZONES_SHIFT) - 1);
 252
 253         if (__builtin_constant_p(bit))
 254                 BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 255         else {
 256 #ifdef CONFIG_DEBUG_VM
 257                 BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 258 #endif
 259         }
 260         return z;
 261 }
 262
 263 /*
 264  * There is only one page-allocator function, and two main namespaces to
 265  * it. The alloc_page*() variants return 'struct page *' and as such
 266  * can allocate highmem pages, the *get*page*() variants return
 267  * virtual kernel addresses to the allocated page(s).
 268  */
 269
 270 static inline int gfp_zonelist(gfp_t flags)
 271 {
 272         if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
 273                 return 1;
 274
 275         return 0;
 276 }
 277
 278 /*
 279  * We get the zone list from the current node and the gfp_mask.
 280  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 281  * There are two zonelists per node, one for all zones with memory and
 282  * one containing just zones from the node the zonelist belongs to.
 283  *
 284  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 285  * optimized to &contig_page_data at compile-time.
 286  */
 287 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 288 {
 289         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 290 }
 291
 292 #ifndef HAVE_ARCH_FREE_PAGE
 293 static inline void arch_free_page(struct page *page, int order) { }
 294 #endif
 295 #ifndef HAVE_ARCH_ALLOC_PAGE
 296 static inline void arch_alloc_page(struct page *page, int order) { }
 297 #endif
 298
 299 struct page *
 300 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 301                        struct zonelist *zonelist, nodemask_t *nodemask);
 302
 303 static inline struct page *
 304 __alloc_pages(gfp_t gfp_mask, unsigned int order,
 305                 struct zonelist *zonelist)
 306 {
 307         return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
 308 }
 309
 310 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 311                                                 unsigned int order)
 312 {
 313         /* Unknown node is current node */
 314         if (nid < 0)
 315                 nid = numa_node_id();
 316
 317         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 318 }
 319
 320 static inline struct page *alloc_pages_exact_node(int nid, gfp_t gfp_mask,
 321                                                 unsigned int order)
 322 {
 323         VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
 324
 325         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 326 }
 327
 328 #ifdef CONFIG_NUMA
 329 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 330
 331 static inline struct page *
 332 alloc_pages(gfp_t gfp_mask, unsigned int order)
 333 {
 334         return alloc_pages_current(gfp_mask, order);
 335 }
 336 extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
 337                         struct vm_area_struct *vma, unsigned long addr,
 338                         int node);
 339 #else
 340 #define alloc_pages(gfp_mask, order) \
 341                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 342 #define alloc_pages_vma(gfp_mask, order, vma, addr, node)       \
 343         alloc_pages(gfp_mask, order)
 344 #endif
 345 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 346 #define alloc_page_vma(gfp_mask, vma, addr)                     \
 347         alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id())
 348 #define alloc_page_vma_node(gfp_mask, vma, addr, node)          \
 349         alloc_pages_vma(gfp_mask, 0, vma, addr, node)
 350
 351 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 352 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 353
 354 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 355 void free_pages_exact(void *virt, size_t size);
 356
 357 #define __get_free_page(gfp_mask) \
 358                 __get_free_pages((gfp_mask), 0)
 359
 360 #define __get_dma_pages(gfp_mask, order) \
 361                 __get_free_pages((gfp_mask) | GFP_DMA, (order))
 362
 363 extern void __free_pages(struct page *page, unsigned int order);
 364 extern void free_pages(unsigned long addr, unsigned int order);
 365 extern void free_hot_cold_page(struct page *page, int cold);
 366
 367 #define __free_page(page) __free_pages((page), 0)
 368 #define free_page(addr) free_pages((addr), 0)
 369
 370 void page_alloc_init(void);
 371 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 372 void drain_all_pages(void);
 373 void drain_local_pages(void *dummy);
 374
 375 extern gfp_t gfp_allowed_mask;
 376
 377 extern void pm_restrict_gfp_mask(void);
 378 extern void pm_restore_gfp_mask(void);
 379
 380 #endif /* __LINUX_GFP_H */