LXR linux/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
  10struct 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 */
 142static 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
 237static 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
 262static 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 */
 279static 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
 285static inline void arch_free_page(struct page *page, int order) { }
 286#endif
 287#ifndef HAVE_ARCH_ALLOC_PAGE
 288static inline void arch_alloc_page(struct page *page, int order) { }
 289#endif
 290
 291struct page *
 292__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 293                       struct zonelist *zonelist, nodemask_t *nodemask);
 294
 295static 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
 302static 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
 312static 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
 321extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 322
 323static inline struct page *
 324alloc_pages(gfp_t gfp_mask, unsigned int order)
 325{
 326        return alloc_pages_current(gfp_mask, order);
 327}
 328extern 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
 337extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 338extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 339
 340void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 341void 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
 349extern void __free_pages(struct page *page, unsigned int order);
 350extern void free_pages(unsigned long addr, unsigned int order);
 351extern 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
 356void page_alloc_init(void);
 357void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 358void drain_all_pages(void);
 359void drain_local_pages(void *dummy);
 360
 361extern gfp_t gfp_allowed_mask;
 362
 363extern void pm_restrict_gfp_mask(void);
 364extern void pm_restore_gfp_mask(void);
 365
 366#endif /* __LINUX_GFP_H */
 367