include/linux/gfp.h

   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
  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_RECLAIMABLE      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_MEMALLOC         0x2000u
  27 #define ___GFP_COMP             0x4000u
  28 #define ___GFP_ZERO             0x8000u
  29 #define ___GFP_NOMEMALLOC       0x10000u
  30 #define ___GFP_HARDWALL         0x20000u
  31 #define ___GFP_THISNODE         0x40000u
  32 #define ___GFP_ATOMIC           0x80000u
  33 #define ___GFP_NOACCOUNT        0x100000u
  34 #define ___GFP_NOTRACK          0x200000u
  35 #define ___GFP_DIRECT_RECLAIM   0x400000u
  36 #define ___GFP_OTHER_NODE       0x800000u
  37 #define ___GFP_WRITE            0x1000000u
  38 #define ___GFP_KSWAPD_RECLAIM   0x2000000u
  39 /* If the above are modified, __GFP_BITS_SHIFT may need updating */
  40
  41 /*
  42  * GFP bitmasks..
  43  *
  44  * Zone modifiers (see linux/mmzone.h - low three bits)
  45  *
  46  * Do not put any conditional on these. If necessary modify the definitions
  47  * without the underscores and use them consistently. The definitions here may
  48  * be used in bit comparisons.
  49  */
  50 #define __GFP_DMA       ((__force gfp_t)___GFP_DMA)
  51 #define __GFP_HIGHMEM   ((__force gfp_t)___GFP_HIGHMEM)
  52 #define __GFP_DMA32     ((__force gfp_t)___GFP_DMA32)
  53 #define __GFP_MOVABLE   ((__force gfp_t)___GFP_MOVABLE)  /* Page is movable */
  54 #define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
  55 /*
  56  * Action modifiers - doesn't change the zoning
  57  *
  58  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  59  * _might_ fail.  This depends upon the particular VM implementation.
  60  *
  61  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  62  * cannot handle allocation failures. New users should be evaluated carefully
  63  * (and the flag should be used only when there is no reasonable failure policy)
  64  * but it is definitely preferable to use the flag rather than opencode endless
  65  * loop around allocator.
  66  *
  67  * __GFP_NORETRY: The VM implementation must not retry indefinitely and will
  68  * return NULL when direct reclaim and memory compaction have failed to allow
  69  * the allocation to succeed.  The OOM killer is not called with the current
  70  * implementation.
  71  *
  72  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  73  * mechanism or reclaimed
  74  */
  75 #define __GFP_ATOMIC    ((__force gfp_t)___GFP_ATOMIC)  /* Caller cannot wait or reschedule */
  76 #define __GFP_HIGH      ((__force gfp_t)___GFP_HIGH)    /* Should access emergency pools? */
  77 #define __GFP_IO        ((__force gfp_t)___GFP_IO)      /* Can start physical IO? */
  78 #define __GFP_FS        ((__force gfp_t)___GFP_FS)      /* Can call down to low-level FS? */
  79 #define __GFP_COLD      ((__force gfp_t)___GFP_COLD)    /* Cache-cold page required */
  80 #define __GFP_NOWARN    ((__force gfp_t)___GFP_NOWARN)  /* Suppress page allocation failure warning */
  81 #define __GFP_REPEAT    ((__force gfp_t)___GFP_REPEAT)  /* See above */
  82 #define __GFP_NOFAIL    ((__force gfp_t)___GFP_NOFAIL)  /* See above */
  83 #define __GFP_NORETRY   ((__force gfp_t)___GFP_NORETRY) /* See above */
  84 #define __GFP_MEMALLOC  ((__force gfp_t)___GFP_MEMALLOC)/* Allow access to emergency reserves */
  85 #define __GFP_COMP      ((__force gfp_t)___GFP_COMP)    /* Add compound page metadata */
  86 #define __GFP_ZERO      ((__force gfp_t)___GFP_ZERO)    /* Return zeroed page on success */
  87 #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC) /* Don't use emergency reserves.
  88                                                          * This takes precedence over the
  89                                                          * __GFP_MEMALLOC flag if both are
  90                                                          * set
  91                                                          */
  92 #define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL) /* Enforce hardwall cpuset memory allocs */
  93 #define __GFP_THISNODE  ((__force gfp_t)___GFP_THISNODE)/* No fallback, no policies */
  94 #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) /* Page is reclaimable */
  95 #define __GFP_NOACCOUNT ((__force gfp_t)___GFP_NOACCOUNT) /* Don't account to kmemcg */
  96 #define __GFP_NOTRACK   ((__force gfp_t)___GFP_NOTRACK)  /* Don't track with kmemcheck */
  97
  98 #define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE) /* On behalf of other node */
  99 #define __GFP_WRITE     ((__force gfp_t)___GFP_WRITE)   /* Allocator intends to dirty page */
 100
 101 /*
 102  * A caller that is willing to wait may enter direct reclaim and will
 103  * wake kswapd to reclaim pages in the background until the high
 104  * watermark is met. A caller may wish to clear __GFP_DIRECT_RECLAIM to
 105  * avoid unnecessary delays when a fallback option is available but
 106  * still allow kswapd to reclaim in the background. The kswapd flag
 107  * can be cleared when the reclaiming of pages would cause unnecessary
 108  * disruption.
 109  */
 110 #define __GFP_WAIT ((__force gfp_t)(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM))
 111 #define __GFP_DIRECT_RECLAIM    ((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
 112 #define __GFP_KSWAPD_RECLAIM    ((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */
 113
 114 /*
 115  * This may seem redundant, but it's a way of annotating false positives vs.
 116  * allocations that simply cannot be supported (e.g. page tables).
 117  */
 118 #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
 119
 120 #define __GFP_BITS_SHIFT 26     /* Room for N __GFP_FOO bits */
 121 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
 122
 123 /*
 124  * GFP_ATOMIC callers can not sleep, need the allocation to succeed.
 125  * A lower watermark is applied to allow access to "atomic reserves"
 126  */
 127 #define GFP_ATOMIC      (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
 128 #define GFP_NOWAIT      (__GFP_KSWAPD_RECLAIM)
 129 #define GFP_NOIO        (__GFP_WAIT)
 130 #define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
 131 #define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
 132 #define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
 133                          __GFP_RECLAIMABLE)
 134 #define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
 135 #define GFP_HIGHUSER    (GFP_USER | __GFP_HIGHMEM)
 136 #define GFP_HIGHUSER_MOVABLE    (GFP_HIGHUSER | __GFP_MOVABLE)
 137 #define GFP_IOFS        (__GFP_IO | __GFP_FS | __GFP_KSWAPD_RECLAIM)
 138 #define GFP_TRANSHUGE   ((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
 139                          __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN) & \
 140                          ~__GFP_KSWAPD_RECLAIM)
 141
 142 /* This mask makes up all the page movable related flags */
 143 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
 144 #define GFP_MOVABLE_SHIFT 3
 145
 146 /* Control page allocator reclaim behavior */
 147 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
 148                         __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
 149                         __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC)
 150
 151 /* Control slab gfp mask during early boot */
 152 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS))
 153
 154 /* Control allocation constraints */
 155 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
 156
 157 /* Do not use these with a slab allocator */
 158 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
 159
 160 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 161    platforms, used as appropriate on others */
 162
 163 #define GFP_DMA         __GFP_DMA
 164
 165 /* 4GB DMA on some platforms */
 166 #define GFP_DMA32       __GFP_DMA32
 167
 168 /* Convert GFP flags to their corresponding migrate type */
 169 static inline int gfpflags_to_migratetype(const gfp_t gfp_flags)
 170 {
 171         VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 172         BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE);
 173         BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE);
 174
 175         if (unlikely(page_group_by_mobility_disabled))
 176                 return MIGRATE_UNMOVABLE;
 177
 178         /* Group based on mobility */
 179         return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
 180 }
 181
 182 static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
 183 {
 184         return gfp_flags & __GFP_DIRECT_RECLAIM;
 185 }
 186
 187 #ifdef CONFIG_HIGHMEM
 188 #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
 189 #else
 190 #define OPT_ZONE_HIGHMEM ZONE_NORMAL
 191 #endif
 192
 193 #ifdef CONFIG_ZONE_DMA
 194 #define OPT_ZONE_DMA ZONE_DMA
 195 #else
 196 #define OPT_ZONE_DMA ZONE_NORMAL
 197 #endif
 198
 199 #ifdef CONFIG_ZONE_DMA32
 200 #define OPT_ZONE_DMA32 ZONE_DMA32
 201 #else
 202 #define OPT_ZONE_DMA32 ZONE_NORMAL
 203 #endif
 204
 205 /*
 206  * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
 207  * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
 208  * and there are 16 of them to cover all possible combinations of
 209  * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
 210  *
 211  * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
 212  * But GFP_MOVABLE is not only a zone specifier but also an allocation
 213  * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
 214  * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
 215  *
 216  *       bit       result
 217  *       =================
 218  *       0x0    => NORMAL
 219  *       0x1    => DMA or NORMAL
 220  *       0x2    => HIGHMEM or NORMAL
 221  *       0x3    => BAD (DMA+HIGHMEM)
 222  *       0x4    => DMA32 or DMA or NORMAL
 223  *       0x5    => BAD (DMA+DMA32)
 224  *       0x6    => BAD (HIGHMEM+DMA32)
 225  *       0x7    => BAD (HIGHMEM+DMA32+DMA)
 226  *       0x8    => NORMAL (MOVABLE+0)
 227  *       0x9    => DMA or NORMAL (MOVABLE+DMA)
 228  *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
 229  *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
 230  *       0xc    => DMA32 (MOVABLE+DMA32)
 231  *       0xd    => BAD (MOVABLE+DMA32+DMA)
 232  *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
 233  *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
 234  *
 235  * ZONES_SHIFT must be <= 2 on 32 bit platforms.
 236  */
 237
 238 #if 16 * ZONES_SHIFT > BITS_PER_LONG
 239 #error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
 240 #endif
 241
 242 #define GFP_ZONE_TABLE ( \
 243         (ZONE_NORMAL << 0 * ZONES_SHIFT)                                      \
 244         | (OPT_ZONE_DMA << ___GFP_DMA * ZONES_SHIFT)                          \
 245         | (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * ZONES_SHIFT)                  \
 246         | (OPT_ZONE_DMA32 << ___GFP_DMA32 * ZONES_SHIFT)                      \
 247         | (ZONE_NORMAL << ___GFP_MOVABLE * ZONES_SHIFT)                       \
 248         | (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * ZONES_SHIFT)       \
 249         | (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * ZONES_SHIFT)   \
 250         | (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * ZONES_SHIFT)   \
 251 )
 252
 253 /*
 254  * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
 255  * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
 256  * entry starting with bit 0. Bit is set if the combination is not
 257  * allowed.
 258  */
 259 #define GFP_ZONE_BAD ( \
 260         1 << (___GFP_DMA | ___GFP_HIGHMEM)                                    \
 261         | 1 << (___GFP_DMA | ___GFP_DMA32)                                    \
 262         | 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)                                \
 263         | 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)                   \
 264         | 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)                 \
 265         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)                   \
 266         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)               \
 267         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
 268 )
 269
 270 static inline enum zone_type gfp_zone(gfp_t flags)
 271 {
 272         enum zone_type z;
 273         int bit = (__force int) (flags & GFP_ZONEMASK);
 274
 275         z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) &
 276                                          ((1 << ZONES_SHIFT) - 1);
 277         VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 278         return z;
 279 }
 280
 281 /*
 282  * There is only one page-allocator function, and two main namespaces to
 283  * it. The alloc_page*() variants return 'struct page *' and as such
 284  * can allocate highmem pages, the *get*page*() variants return
 285  * virtual kernel addresses to the allocated page(s).
 286  */
 287
 288 static inline int gfp_zonelist(gfp_t flags)
 289 {
 290         if (IS_ENABLED(CONFIG_NUMA) && unlikely(flags & __GFP_THISNODE))
 291                 return 1;
 292
 293         return 0;
 294 }
 295
 296 /*
 297  * We get the zone list from the current node and the gfp_mask.
 298  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 299  * There are two zonelists per node, one for all zones with memory and
 300  * one containing just zones from the node the zonelist belongs to.
 301  *
 302  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 303  * optimized to &contig_page_data at compile-time.
 304  */
 305 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 306 {
 307         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 308 }
 309
 310 #ifndef HAVE_ARCH_FREE_PAGE
 311 static inline void arch_free_page(struct page *page, int order) { }
 312 #endif
 313 #ifndef HAVE_ARCH_ALLOC_PAGE
 314 static inline void arch_alloc_page(struct page *page, int order) { }
 315 #endif
 316
 317 struct page *
 318 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 319                        struct zonelist *zonelist, nodemask_t *nodemask);
 320
 321 static inline struct page *
 322 __alloc_pages(gfp_t gfp_mask, unsigned int order,
 323                 struct zonelist *zonelist)
 324 {
 325         return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
 326 }
 327
 328 /*
 329  * Allocate pages, preferring the node given as nid. The node must be valid and
 330  * online. For more general interface, see alloc_pages_node().
 331  */
 332 static inline struct page *
 333 __alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
 334 {
 335         VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
 336         VM_WARN_ON(!node_online(nid));
 337
 338         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 339 }
 340
 341 /*
 342  * Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,
 343  * prefer the current CPU's closest node. Otherwise node must be valid and
 344  * online.
 345  */
 346 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 347                                                 unsigned int order)
 348 {
 349         if (nid == NUMA_NO_NODE)
 350                 nid = numa_mem_id();
 351
 352         return __alloc_pages_node(nid, gfp_mask, order);
 353 }
 354
 355 #ifdef CONFIG_NUMA
 356 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 357
 358 static inline struct page *
 359 alloc_pages(gfp_t gfp_mask, unsigned int order)
 360 {
 361         return alloc_pages_current(gfp_mask, order);
 362 }
 363 extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
 364                         struct vm_area_struct *vma, unsigned long addr,
 365                         int node, bool hugepage);
 366 #define alloc_hugepage_vma(gfp_mask, vma, addr, order)  \
 367         alloc_pages_vma(gfp_mask, order, vma, addr, numa_node_id(), true)
 368 #else
 369 #define alloc_pages(gfp_mask, order) \
 370                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 371 #define alloc_pages_vma(gfp_mask, order, vma, addr, node, false)\
 372         alloc_pages(gfp_mask, order)
 373 #define alloc_hugepage_vma(gfp_mask, vma, addr, order)  \
 374         alloc_pages(gfp_mask, order)
 375 #endif
 376 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 377 #define alloc_page_vma(gfp_mask, vma, addr)                     \
 378         alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id(), false)
 379 #define alloc_page_vma_node(gfp_mask, vma, addr, node)          \
 380         alloc_pages_vma(gfp_mask, 0, vma, addr, node, false)
 381
 382 extern struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order);
 383 extern struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask,
 384                                           unsigned int order);
 385
 386 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 387 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 388
 389 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 390 void free_pages_exact(void *virt, size_t size);
 391 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
 392
 393 #define __get_free_page(gfp_mask) \
 394                 __get_free_pages((gfp_mask), 0)
 395
 396 #define __get_dma_pages(gfp_mask, order) \
 397                 __get_free_pages((gfp_mask) | GFP_DMA, (order))
 398
 399 extern void __free_pages(struct page *page, unsigned int order);
 400 extern void free_pages(unsigned long addr, unsigned int order);
 401 extern void free_hot_cold_page(struct page *page, bool cold);
 402 extern void free_hot_cold_page_list(struct list_head *list, bool cold);
 403
 404 struct page_frag_cache;
 405 extern void *__alloc_page_frag(struct page_frag_cache *nc,
 406                                unsigned int fragsz, gfp_t gfp_mask);
 407 extern void __free_page_frag(void *addr);
 408
 409 extern void __free_kmem_pages(struct page *page, unsigned int order);
 410 extern void free_kmem_pages(unsigned long addr, unsigned int order);
 411
 412 #define __free_page(page) __free_pages((page), 0)
 413 #define free_page(addr) free_pages((addr), 0)
 414
 415 void page_alloc_init(void);
 416 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 417 void drain_all_pages(struct zone *zone);
 418 void drain_local_pages(struct zone *zone);
 419
 420 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 421 void page_alloc_init_late(void);
 422 #else
 423 static inline void page_alloc_init_late(void)
 424 {
 425 }
 426 #endif
 427
 428 /*
 429  * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
 430  * GFP flags are used before interrupts are enabled. Once interrupts are
 431  * enabled, it is set to __GFP_BITS_MASK while the system is running. During
 432  * hibernation, it is used by PM to avoid I/O during memory allocation while
 433  * devices are suspended.
 434  */
 435 extern gfp_t gfp_allowed_mask;
 436
 437 /* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
 438 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
 439
 440 extern void pm_restrict_gfp_mask(void);
 441 extern void pm_restore_gfp_mask(void);
 442
 443 #ifdef CONFIG_PM_SLEEP
 444 extern bool pm_suspended_storage(void);
 445 #else
 446 static inline bool pm_suspended_storage(void)
 447 {
 448         return false;
 449 }
 450 #endif /* CONFIG_PM_SLEEP */
 451
 452 #ifdef CONFIG_CMA
 453
 454 /* The below functions must be run on a range from a single zone. */
 455 extern int alloc_contig_range(unsigned long start, unsigned long end,
 456                               unsigned migratetype);
 457 extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
 458
 459 /* CMA stuff */
 460 extern void init_cma_reserved_pageblock(struct page *page);
 461
 462 #endif
 463
 464 #endif /* __LINUX_GFP_H */