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