linux/include/linux/gfp.h
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   1#ifndef __LINUX_GFP_H
   2#define __LINUX_GFP_H
   3
   4#include <linux/mmdebug.h>
   5#include <linux/mmzone.h>
   6#include <linux/stddef.h>
   7#include <linux/linkage.h>
   8#include <linux/topology.h>
   9
  10struct vm_area_struct;
  11
  12/*
  13 * In case of changes, please don't forget to update
  14 * include/trace/events/mmflags.h and tools/perf/builtin-kmem.c
  15 */
  16
  17/* Plain integer GFP bitmasks. Do not use this directly. */
  18#define ___GFP_DMA              0x01u
  19#define ___GFP_HIGHMEM          0x02u
  20#define ___GFP_DMA32            0x04u
  21#define ___GFP_MOVABLE          0x08u
  22#define ___GFP_RECLAIMABLE      0x10u
  23#define ___GFP_HIGH             0x20u
  24#define ___GFP_IO               0x40u
  25#define ___GFP_FS               0x80u
  26#define ___GFP_COLD             0x100u
  27#define ___GFP_NOWARN           0x200u
  28#define ___GFP_REPEAT           0x400u
  29#define ___GFP_NOFAIL           0x800u
  30#define ___GFP_NORETRY          0x1000u
  31#define ___GFP_MEMALLOC         0x2000u
  32#define ___GFP_COMP             0x4000u
  33#define ___GFP_ZERO             0x8000u
  34#define ___GFP_NOMEMALLOC       0x10000u
  35#define ___GFP_HARDWALL         0x20000u
  36#define ___GFP_THISNODE         0x40000u
  37#define ___GFP_ATOMIC           0x80000u
  38#define ___GFP_ACCOUNT          0x100000u
  39#define ___GFP_NOTRACK          0x200000u
  40#define ___GFP_DIRECT_RECLAIM   0x400000u
  41#define ___GFP_OTHER_NODE       0x800000u
  42#define ___GFP_WRITE            0x1000000u
  43#define ___GFP_KSWAPD_RECLAIM   0x2000000u
  44/* If the above are modified, __GFP_BITS_SHIFT may need updating */
  45
  46/*
  47 * Physical address zone modifiers (see linux/mmzone.h - low four bits)
  48 *
  49 * Do not put any conditional on these. If necessary modify the definitions
  50 * without the underscores and use them consistently. The definitions here may
  51 * be used in bit comparisons.
  52 */
  53#define __GFP_DMA       ((__force gfp_t)___GFP_DMA)
  54#define __GFP_HIGHMEM   ((__force gfp_t)___GFP_HIGHMEM)
  55#define __GFP_DMA32     ((__force gfp_t)___GFP_DMA32)
  56#define __GFP_MOVABLE   ((__force gfp_t)___GFP_MOVABLE)  /* ZONE_MOVABLE allowed */
  57#define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
  58
  59/*
  60 * Page mobility and placement hints
  61 *
  62 * These flags provide hints about how mobile the page is. Pages with similar
  63 * mobility are placed within the same pageblocks to minimise problems due
  64 * to external fragmentation.
  65 *
  66 * __GFP_MOVABLE (also a zone modifier) indicates that the page can be
  67 *   moved by page migration during memory compaction or can be reclaimed.
  68 *
  69 * __GFP_RECLAIMABLE is used for slab allocations that specify
  70 *   SLAB_RECLAIM_ACCOUNT and whose pages can be freed via shrinkers.
  71 *
  72 * __GFP_WRITE indicates the caller intends to dirty the page. Where possible,
  73 *   these pages will be spread between local zones to avoid all the dirty
  74 *   pages being in one zone (fair zone allocation policy).
  75 *
  76 * __GFP_HARDWALL enforces the cpuset memory allocation policy.
  77 *
  78 * __GFP_THISNODE forces the allocation to be satisified from the requested
  79 *   node with no fallbacks or placement policy enforcements.
  80 *
  81 * __GFP_ACCOUNT causes the allocation to be accounted to kmemcg (only relevant
  82 *   to kmem allocations).
  83 */
  84#define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
  85#define __GFP_WRITE     ((__force gfp_t)___GFP_WRITE)
  86#define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL)
  87#define __GFP_THISNODE  ((__force gfp_t)___GFP_THISNODE)
  88#define __GFP_ACCOUNT   ((__force gfp_t)___GFP_ACCOUNT)
  89
  90/*
  91 * Watermark modifiers -- controls access to emergency reserves
  92 *
  93 * __GFP_HIGH indicates that the caller is high-priority and that granting
  94 *   the request is necessary before the system can make forward progress.
  95 *   For example, creating an IO context to clean pages.
  96 *
  97 * __GFP_ATOMIC indicates that the caller cannot reclaim or sleep and is
  98 *   high priority. Users are typically interrupt handlers. This may be
  99 *   used in conjunction with __GFP_HIGH
 100 *
 101 * __GFP_MEMALLOC allows access to all memory. This should only be used when
 102 *   the caller guarantees the allocation will allow more memory to be freed
 103 *   very shortly e.g. process exiting or swapping. Users either should
 104 *   be the MM or co-ordinating closely with the VM (e.g. swap over NFS).
 105 *
 106 * __GFP_NOMEMALLOC is used to explicitly forbid access to emergency reserves.
 107 *   This takes precedence over the __GFP_MEMALLOC flag if both are set.
 108 */
 109#define __GFP_ATOMIC    ((__force gfp_t)___GFP_ATOMIC)
 110#define __GFP_HIGH      ((__force gfp_t)___GFP_HIGH)
 111#define __GFP_MEMALLOC  ((__force gfp_t)___GFP_MEMALLOC)
 112#define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC)
 113
 114/*
 115 * Reclaim modifiers
 116 *
 117 * __GFP_IO can start physical IO.
 118 *
 119 * __GFP_FS can call down to the low-level FS. Clearing the flag avoids the
 120 *   allocator recursing into the filesystem which might already be holding
 121 *   locks.
 122 *
 123 * __GFP_DIRECT_RECLAIM indicates that the caller may enter direct reclaim.
 124 *   This flag can be cleared to avoid unnecessary delays when a fallback
 125 *   option is available.
 126 *
 127 * __GFP_KSWAPD_RECLAIM indicates that the caller wants to wake kswapd when
 128 *   the low watermark is reached and have it reclaim pages until the high
 129 *   watermark is reached. A caller may wish to clear this flag when fallback
 130 *   options are available and the reclaim is likely to disrupt the system. The
 131 *   canonical example is THP allocation where a fallback is cheap but
 132 *   reclaim/compaction may cause indirect stalls.
 133 *
 134 * __GFP_RECLAIM is shorthand to allow/forbid both direct and kswapd reclaim.
 135 *
 136 * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
 137 *   _might_ fail.  This depends upon the particular VM implementation.
 138 *
 139 * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
 140 *   cannot handle allocation failures. New users should be evaluated carefully
 141 *   (and the flag should be used only when there is no reasonable failure
 142 *   policy) but it is definitely preferable to use the flag rather than
 143 *   opencode endless loop around allocator.
 144 *
 145 * __GFP_NORETRY: The VM implementation must not retry indefinitely and will
 146 *   return NULL when direct reclaim and memory compaction have failed to allow
 147 *   the allocation to succeed.  The OOM killer is not called with the current
 148 *   implementation.
 149 */
 150#define __GFP_IO        ((__force gfp_t)___GFP_IO)
 151#define __GFP_FS        ((__force gfp_t)___GFP_FS)
 152#define __GFP_DIRECT_RECLAIM    ((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
 153#define __GFP_KSWAPD_RECLAIM    ((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */
 154#define __GFP_RECLAIM ((__force gfp_t)(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM))
 155#define __GFP_REPEAT    ((__force gfp_t)___GFP_REPEAT)
 156#define __GFP_NOFAIL    ((__force gfp_t)___GFP_NOFAIL)
 157#define __GFP_NORETRY   ((__force gfp_t)___GFP_NORETRY)
 158
 159/*
 160 * Action modifiers
 161 *
 162 * __GFP_COLD indicates that the caller does not expect to be used in the near
 163 *   future. Where possible, a cache-cold page will be returned.
 164 *
 165 * __GFP_NOWARN suppresses allocation failure reports.
 166 *
 167 * __GFP_COMP address compound page metadata.
 168 *
 169 * __GFP_ZERO returns a zeroed page on success.
 170 *
 171 * __GFP_NOTRACK avoids tracking with kmemcheck.
 172 *
 173 * __GFP_NOTRACK_FALSE_POSITIVE is an alias of __GFP_NOTRACK. It's a means of
 174 *   distinguishing in the source between false positives and allocations that
 175 *   cannot be supported (e.g. page tables).
 176 *
 177 * __GFP_OTHER_NODE is for allocations that are on a remote node but that
 178 *   should not be accounted for as a remote allocation in vmstat. A
 179 *   typical user would be khugepaged collapsing a huge page on a remote
 180 *   node.
 181 */
 182#define __GFP_COLD      ((__force gfp_t)___GFP_COLD)
 183#define __GFP_NOWARN    ((__force gfp_t)___GFP_NOWARN)
 184#define __GFP_COMP      ((__force gfp_t)___GFP_COMP)
 185#define __GFP_ZERO      ((__force gfp_t)___GFP_ZERO)
 186#define __GFP_NOTRACK   ((__force gfp_t)___GFP_NOTRACK)
 187#define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
 188#define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE)
 189
 190/* Room for N __GFP_FOO bits */
 191#define __GFP_BITS_SHIFT 26
 192#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
 193
 194/*
 195 * Useful GFP flag combinations that are commonly used. It is recommended
 196 * that subsystems start with one of these combinations and then set/clear
 197 * __GFP_FOO flags as necessary.
 198 *
 199 * GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower
 200 *   watermark is applied to allow access to "atomic reserves"
 201 *
 202 * GFP_KERNEL is typical for kernel-internal allocations. The caller requires
 203 *   ZONE_NORMAL or a lower zone for direct access but can direct reclaim.
 204 *
 205 * GFP_KERNEL_ACCOUNT is the same as GFP_KERNEL, except the allocation is
 206 *   accounted to kmemcg.
 207 *
 208 * GFP_NOWAIT is for kernel allocations that should not stall for direct
 209 *   reclaim, start physical IO or use any filesystem callback.
 210 *
 211 * GFP_NOIO will use direct reclaim to discard clean pages or slab pages
 212 *   that do not require the starting of any physical IO.
 213 *
 214 * GFP_NOFS will use direct reclaim but will not use any filesystem interfaces.
 215 *
 216 * GFP_USER is for userspace allocations that also need to be directly
 217 *   accessibly by the kernel or hardware. It is typically used by hardware
 218 *   for buffers that are mapped to userspace (e.g. graphics) that hardware
 219 *   still must DMA to. cpuset limits are enforced for these allocations.
 220 *
 221 * GFP_DMA exists for historical reasons and should be avoided where possible.
 222 *   The flags indicates that the caller requires that the lowest zone be
 223 *   used (ZONE_DMA or 16M on x86-64). Ideally, this would be removed but
 224 *   it would require careful auditing as some users really require it and
 225 *   others use the flag to avoid lowmem reserves in ZONE_DMA and treat the
 226 *   lowest zone as a type of emergency reserve.
 227 *
 228 * GFP_DMA32 is similar to GFP_DMA except that the caller requires a 32-bit
 229 *   address.
 230 *
 231 * GFP_HIGHUSER is for userspace allocations that may be mapped to userspace,
 232 *   do not need to be directly accessible by the kernel but that cannot
 233 *   move once in use. An example may be a hardware allocation that maps
 234 *   data directly into userspace but has no addressing limitations.
 235 *
 236 * GFP_HIGHUSER_MOVABLE is for userspace allocations that the kernel does not
 237 *   need direct access to but can use kmap() when access is required. They
 238 *   are expected to be movable via page reclaim or page migration. Typically,
 239 *   pages on the LRU would also be allocated with GFP_HIGHUSER_MOVABLE.
 240 *
 241 * GFP_TRANSHUGE is used for THP allocations. They are compound allocations
 242 *   that will fail quickly if memory is not available and will not wake
 243 *   kswapd on failure.
 244 */
 245#define GFP_ATOMIC      (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
 246#define GFP_KERNEL      (__GFP_RECLAIM | __GFP_IO | __GFP_FS)
 247#define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
 248#define GFP_NOWAIT      (__GFP_KSWAPD_RECLAIM)
 249#define GFP_NOIO        (__GFP_RECLAIM)
 250#define GFP_NOFS        (__GFP_RECLAIM | __GFP_IO)
 251#define GFP_TEMPORARY   (__GFP_RECLAIM | __GFP_IO | __GFP_FS | \
 252                         __GFP_RECLAIMABLE)
 253#define GFP_USER        (__GFP_RECLAIM | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
 254#define GFP_DMA         __GFP_DMA
 255#define GFP_DMA32       __GFP_DMA32
 256#define GFP_HIGHUSER    (GFP_USER | __GFP_HIGHMEM)
 257#define GFP_HIGHUSER_MOVABLE    (GFP_HIGHUSER | __GFP_MOVABLE)
 258#define GFP_TRANSHUGE   ((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
 259                         __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN) & \
 260                         ~__GFP_RECLAIM)
 261
 262/* Convert GFP flags to their corresponding migrate type */
 263#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
 264#define GFP_MOVABLE_SHIFT 3
 265
 266static inline int gfpflags_to_migratetype(const gfp_t gfp_flags)
 267{
 268        VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 269        BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE);
 270        BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE);
 271
 272        if (unlikely(page_group_by_mobility_disabled))
 273                return MIGRATE_UNMOVABLE;
 274
 275        /* Group based on mobility */
 276        return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
 277}
 278#undef GFP_MOVABLE_MASK
 279#undef GFP_MOVABLE_SHIFT
 280
 281static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
 282{
 283        return !!(gfp_flags & __GFP_DIRECT_RECLAIM);
 284}
 285
 286#ifdef CONFIG_HIGHMEM
 287#define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
 288#else
 289#define OPT_ZONE_HIGHMEM ZONE_NORMAL
 290#endif
 291
 292#ifdef CONFIG_ZONE_DMA
 293#define OPT_ZONE_DMA ZONE_DMA
 294#else
 295#define OPT_ZONE_DMA ZONE_NORMAL
 296#endif
 297
 298#ifdef CONFIG_ZONE_DMA32
 299#define OPT_ZONE_DMA32 ZONE_DMA32
 300#else
 301#define OPT_ZONE_DMA32 ZONE_NORMAL
 302#endif
 303
 304/*
 305 * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
 306 * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
 307 * and there are 16 of them to cover all possible combinations of
 308 * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
 309 *
 310 * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
 311 * But GFP_MOVABLE is not only a zone specifier but also an allocation
 312 * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
 313 * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
 314 *
 315 *       bit       result
 316 *       =================
 317 *       0x0    => NORMAL
 318 *       0x1    => DMA or NORMAL
 319 *       0x2    => HIGHMEM or NORMAL
 320 *       0x3    => BAD (DMA+HIGHMEM)
 321 *       0x4    => DMA32 or DMA or NORMAL
 322 *       0x5    => BAD (DMA+DMA32)
 323 *       0x6    => BAD (HIGHMEM+DMA32)
 324 *       0x7    => BAD (HIGHMEM+DMA32+DMA)
 325 *       0x8    => NORMAL (MOVABLE+0)
 326 *       0x9    => DMA or NORMAL (MOVABLE+DMA)
 327 *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
 328 *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
 329 *       0xc    => DMA32 (MOVABLE+DMA32)
 330 *       0xd    => BAD (MOVABLE+DMA32+DMA)
 331 *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
 332 *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
 333 *
 334 * GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.
 335 */
 336
 337#if defined(CONFIG_ZONE_DEVICE) && (MAX_NR_ZONES-1) <= 4
 338/* ZONE_DEVICE is not a valid GFP zone specifier */
 339#define GFP_ZONES_SHIFT 2
 340#else
 341#define GFP_ZONES_SHIFT ZONES_SHIFT
 342#endif
 343
 344#if 16 * GFP_ZONES_SHIFT > BITS_PER_LONG
 345#error GFP_ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
 346#endif
 347
 348#define GFP_ZONE_TABLE ( \
 349        (ZONE_NORMAL << 0 * GFP_ZONES_SHIFT)                                   \
 350        | (OPT_ZONE_DMA << ___GFP_DMA * GFP_ZONES_SHIFT)                       \
 351        | (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * GFP_ZONES_SHIFT)               \
 352        | (OPT_ZONE_DMA32 << ___GFP_DMA32 * GFP_ZONES_SHIFT)                   \
 353        | (ZONE_NORMAL << ___GFP_MOVABLE * GFP_ZONES_SHIFT)                    \
 354        | (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * GFP_ZONES_SHIFT)    \
 355        | (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * GFP_ZONES_SHIFT)\
 356        | (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * GFP_ZONES_SHIFT)\
 357)
 358
 359/*
 360 * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
 361 * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
 362 * entry starting with bit 0. Bit is set if the combination is not
 363 * allowed.
 364 */
 365#define GFP_ZONE_BAD ( \
 366        1 << (___GFP_DMA | ___GFP_HIGHMEM)                                    \
 367        | 1 << (___GFP_DMA | ___GFP_DMA32)                                    \
 368        | 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)                                \
 369        | 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)                   \
 370        | 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)                 \
 371        | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)                   \
 372        | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)               \
 373        | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
 374)
 375
 376static inline enum zone_type gfp_zone(gfp_t flags)
 377{
 378        enum zone_type z;
 379        int bit = (__force int) (flags & GFP_ZONEMASK);
 380
 381        z = (GFP_ZONE_TABLE >> (bit * GFP_ZONES_SHIFT)) &
 382                                         ((1 << GFP_ZONES_SHIFT) - 1);
 383        VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 384        return z;
 385}
 386
 387/*
 388 * There is only one page-allocator function, and two main namespaces to
 389 * it. The alloc_page*() variants return 'struct page *' and as such
 390 * can allocate highmem pages, the *get*page*() variants return
 391 * virtual kernel addresses to the allocated page(s).
 392 */
 393
 394static inline int gfp_zonelist(gfp_t flags)
 395{
 396#ifdef CONFIG_NUMA
 397        if (unlikely(flags & __GFP_THISNODE))
 398                return ZONELIST_NOFALLBACK;
 399#endif
 400        return ZONELIST_FALLBACK;
 401}
 402
 403/*
 404 * We get the zone list from the current node and the gfp_mask.
 405 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 406 * There are two zonelists per node, one for all zones with memory and
 407 * one containing just zones from the node the zonelist belongs to.
 408 *
 409 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 410 * optimized to &contig_page_data at compile-time.
 411 */
 412static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 413{
 414        return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 415}
 416
 417#ifndef HAVE_ARCH_FREE_PAGE
 418static inline void arch_free_page(struct page *page, int order) { }
 419#endif
 420#ifndef HAVE_ARCH_ALLOC_PAGE
 421static inline void arch_alloc_page(struct page *page, int order) { }
 422#endif
 423
 424struct page *
 425__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 426                       struct zonelist *zonelist, nodemask_t *nodemask);
 427
 428static inline struct page *
 429__alloc_pages(gfp_t gfp_mask, unsigned int order,
 430                struct zonelist *zonelist)
 431{
 432        return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
 433}
 434
 435/*
 436 * Allocate pages, preferring the node given as nid. The node must be valid and
 437 * online. For more general interface, see alloc_pages_node().
 438 */
 439static inline struct page *
 440__alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
 441{
 442        VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
 443        VM_WARN_ON(!node_online(nid));
 444
 445        return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 446}
 447
 448/*
 449 * Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,
 450 * prefer the current CPU's closest node. Otherwise node must be valid and
 451 * online.
 452 */
 453static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 454                                                unsigned int order)
 455{
 456        if (nid == NUMA_NO_NODE)
 457                nid = numa_mem_id();
 458
 459        return __alloc_pages_node(nid, gfp_mask, order);
 460}
 461
 462#ifdef CONFIG_NUMA
 463extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 464
 465static inline struct page *
 466alloc_pages(gfp_t gfp_mask, unsigned int order)
 467{
 468        return alloc_pages_current(gfp_mask, order);
 469}
 470extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
 471                        struct vm_area_struct *vma, unsigned long addr,
 472                        int node, bool hugepage);
 473#define alloc_hugepage_vma(gfp_mask, vma, addr, order)  \
 474        alloc_pages_vma(gfp_mask, order, vma, addr, numa_node_id(), true)
 475#else
 476#define alloc_pages(gfp_mask, order) \
 477                alloc_pages_node(numa_node_id(), gfp_mask, order)
 478#define alloc_pages_vma(gfp_mask, order, vma, addr, node, false)\
 479        alloc_pages(gfp_mask, order)
 480#define alloc_hugepage_vma(gfp_mask, vma, addr, order)  \
 481        alloc_pages(gfp_mask, order)
 482#endif
 483#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 484#define alloc_page_vma(gfp_mask, vma, addr)                     \
 485        alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id(), false)
 486#define alloc_page_vma_node(gfp_mask, vma, addr, node)          \
 487        alloc_pages_vma(gfp_mask, 0, vma, addr, node, false)
 488
 489extern struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order);
 490extern struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask,
 491                                          unsigned int order);
 492
 493extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 494extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 495
 496void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 497void free_pages_exact(void *virt, size_t size);
 498void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
 499
 500#define __get_free_page(gfp_mask) \
 501                __get_free_pages((gfp_mask), 0)
 502
 503#define __get_dma_pages(gfp_mask, order) \
 504                __get_free_pages((gfp_mask) | GFP_DMA, (order))
 505
 506extern void __free_pages(struct page *page, unsigned int order);
 507extern void free_pages(unsigned long addr, unsigned int order);
 508extern void free_hot_cold_page(struct page *page, bool cold);
 509extern void free_hot_cold_page_list(struct list_head *list, bool cold);
 510
 511struct page_frag_cache;
 512extern void *__alloc_page_frag(struct page_frag_cache *nc,
 513                               unsigned int fragsz, gfp_t gfp_mask);
 514extern void __free_page_frag(void *addr);
 515
 516extern void __free_kmem_pages(struct page *page, unsigned int order);
 517extern void free_kmem_pages(unsigned long addr, unsigned int order);
 518
 519#define __free_page(page) __free_pages((page), 0)
 520#define free_page(addr) free_pages((addr), 0)
 521
 522void page_alloc_init(void);
 523void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 524void drain_all_pages(struct zone *zone);
 525void drain_local_pages(struct zone *zone);
 526
 527void page_alloc_init_late(void);
 528
 529/*
 530 * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
 531 * GFP flags are used before interrupts are enabled. Once interrupts are
 532 * enabled, it is set to __GFP_BITS_MASK while the system is running. During
 533 * hibernation, it is used by PM to avoid I/O during memory allocation while
 534 * devices are suspended.
 535 */
 536extern gfp_t gfp_allowed_mask;
 537
 538/* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
 539bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
 540
 541extern void pm_restrict_gfp_mask(void);
 542extern void pm_restore_gfp_mask(void);
 543
 544#ifdef CONFIG_PM_SLEEP
 545extern bool pm_suspended_storage(void);
 546#else
 547static inline bool pm_suspended_storage(void)
 548{
 549        return false;
 550}
 551#endif /* CONFIG_PM_SLEEP */
 552
 553#if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
 554/* The below functions must be run on a range from a single zone. */
 555extern int alloc_contig_range(unsigned long start, unsigned long end,
 556                              unsigned migratetype);
 557extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
 558#endif
 559
 560#ifdef CONFIG_CMA
 561/* CMA stuff */
 562extern void init_cma_reserved_pageblock(struct page *page);
 563#endif
 564
 565#endif /* __LINUX_GFP_H */
 566