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
   8struct vm_area_struct;
   9
  10/*
  11 * GFP bitmasks..
  12 *
  13 * Zone modifiers (see linux/mmzone.h - low three bits)
  14 *
  15 * Do not put any conditional on these. If necessary modify the definitions
  16 * without the underscores and use the consistently. The definitions here may
  17 * be used in bit comparisons.
  18 */
  19#define __GFP_DMA       ((__force gfp_t)0x01u)
  20#define __GFP_HIGHMEM   ((__force gfp_t)0x02u)
  21#define __GFP_DMA32     ((__force gfp_t)0x04u)
  22
  23/*
  24 * Action modifiers - doesn't change the zoning
  25 *
  26 * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  27 * _might_ fail.  This depends upon the particular VM implementation.
  28 *
  29 * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  30 * cannot handle allocation failures.
  31 *
  32 * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  33 *
  34 * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  35 * mechanism or reclaimed
  36 */
  37#define __GFP_WAIT      ((__force gfp_t)0x10u)  /* Can wait and reschedule? */
  38#define __GFP_HIGH      ((__force gfp_t)0x20u)  /* Should access emergency pools? */
  39#define __GFP_IO        ((__force gfp_t)0x40u)  /* Can start physical IO? */
  40#define __GFP_FS        ((__force gfp_t)0x80u)  /* Can call down to low-level FS? */
  41#define __GFP_COLD      ((__force gfp_t)0x100u) /* Cache-cold page required */
  42#define __GFP_NOWARN    ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
  43#define __GFP_REPEAT    ((__force gfp_t)0x400u) /* See above */
  44#define __GFP_NOFAIL    ((__force gfp_t)0x800u) /* See above */
  45#define __GFP_NORETRY   ((__force gfp_t)0x1000u)/* See above */
  46#define __GFP_COMP      ((__force gfp_t)0x4000u)/* Add compound page metadata */
  47#define __GFP_ZERO      ((__force gfp_t)0x8000u)/* Return zeroed page on success */
  48#define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
  49#define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
  50#define __GFP_THISNODE  ((__force gfp_t)0x40000u)/* No fallback, no policies */
  51#define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */
  52#define __GFP_MOVABLE   ((__force gfp_t)0x100000u)  /* Page is movable */
  53
  54#define __GFP_BITS_SHIFT 21     /* Room for 21 __GFP_FOO bits */
  55#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  56
  57/* This equals 0, but use constants in case they ever change */
  58#define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
  59/* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
  60#define GFP_ATOMIC      (__GFP_HIGH)
  61#define GFP_NOIO        (__GFP_WAIT)
  62#define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
  63#define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
  64#define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  65                         __GFP_RECLAIMABLE)
  66#define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
  67#define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
  68                         __GFP_HIGHMEM)
  69#define GFP_HIGHUSER_MOVABLE    (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  70                                 __GFP_HARDWALL | __GFP_HIGHMEM | \
  71                                 __GFP_MOVABLE)
  72
  73#ifdef CONFIG_NUMA
  74#define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  75#else
  76#define GFP_THISNODE    ((__force gfp_t)0)
  77#endif
  78
  79/* This mask makes up all the page movable related flags */
  80#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
  81
  82/* Control page allocator reclaim behavior */
  83#define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
  84                        __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
  85                        __GFP_NORETRY|__GFP_NOMEMALLOC)
  86
  87/* Control allocation constraints */
  88#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
  89
  90/* Do not use these with a slab allocator */
  91#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
  92
  93/* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
  94   platforms, used as appropriate on others */
  95
  96#define GFP_DMA         __GFP_DMA
  97
  98/* 4GB DMA on some platforms */
  99#define GFP_DMA32       __GFP_DMA32
 100
 101/* Convert GFP flags to their corresponding migrate type */
 102static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 103{
 104        WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 105
 106        if (unlikely(page_group_by_mobility_disabled))
 107                return MIGRATE_UNMOVABLE;
 108
 109        /* Group based on mobility */
 110        return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 111                ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 112}
 113
 114static inline enum zone_type gfp_zone(gfp_t flags)
 115{
 116#ifdef CONFIG_ZONE_DMA
 117        if (flags & __GFP_DMA)
 118                return ZONE_DMA;
 119#endif
 120#ifdef CONFIG_ZONE_DMA32
 121        if (flags & __GFP_DMA32)
 122                return ZONE_DMA32;
 123#endif
 124        if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
 125                        (__GFP_HIGHMEM | __GFP_MOVABLE))
 126                return ZONE_MOVABLE;
 127#ifdef CONFIG_HIGHMEM
 128        if (flags & __GFP_HIGHMEM)
 129                return ZONE_HIGHMEM;
 130#endif
 131        return ZONE_NORMAL;
 132}
 133
 134/*
 135 * There is only one page-allocator function, and two main namespaces to
 136 * it. The alloc_page*() variants return 'struct page *' and as such
 137 * can allocate highmem pages, the *get*page*() variants return
 138 * virtual kernel addresses to the allocated page(s).
 139 */
 140
 141static inline int gfp_zonelist(gfp_t flags)
 142{
 143        if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
 144                return 1;
 145
 146        return 0;
 147}
 148
 149/*
 150 * We get the zone list from the current node and the gfp_mask.
 151 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 152 * There are two zonelists per node, one for all zones with memory and
 153 * one containing just zones from the node the zonelist belongs to.
 154 *
 155 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 156 * optimized to &contig_page_data at compile-time.
 157 */
 158static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 159{
 160        return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 161}
 162
 163#ifndef HAVE_ARCH_FREE_PAGE
 164static inline void arch_free_page(struct page *page, int order) { }
 165#endif
 166#ifndef HAVE_ARCH_ALLOC_PAGE
 167static inline void arch_alloc_page(struct page *page, int order) { }
 168#endif
 169
 170struct page *
 171__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
 172                       struct zonelist *zonelist, nodemask_t *nodemask);
 173
 174static inline struct page *
 175__alloc_pages(gfp_t gfp_mask, unsigned int order,
 176                struct zonelist *zonelist)
 177{
 178        return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
 179}
 180
 181static inline struct page *
 182__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 183                struct zonelist *zonelist, nodemask_t *nodemask)
 184{
 185        return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
 186}
 187
 188
 189static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 190                                                unsigned int order)
 191{
 192        if (unlikely(order >= MAX_ORDER))
 193                return NULL;
 194
 195        /* Unknown node is current node */
 196        if (nid < 0)
 197                nid = numa_node_id();
 198
 199        return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 200}
 201
 202#ifdef CONFIG_NUMA
 203extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 204
 205static inline struct page *
 206alloc_pages(gfp_t gfp_mask, unsigned int order)
 207{
 208        if (unlikely(order >= MAX_ORDER))
 209                return NULL;
 210
 211        return alloc_pages_current(gfp_mask, order);
 212}
 213extern struct page *alloc_page_vma(gfp_t gfp_mask,
 214                        struct vm_area_struct *vma, unsigned long addr);
 215#else
 216#define alloc_pages(gfp_mask, order) \
 217                alloc_pages_node(numa_node_id(), gfp_mask, order)
 218#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 219#endif
 220#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 221
 222extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 223extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 224
 225void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 226void free_pages_exact(void *virt, size_t size);
 227
 228#define __get_free_page(gfp_mask) \
 229                __get_free_pages((gfp_mask),0)
 230
 231#define __get_dma_pages(gfp_mask, order) \
 232                __get_free_pages((gfp_mask) | GFP_DMA,(order))
 233
 234extern void __free_pages(struct page *page, unsigned int order);
 235extern void free_pages(unsigned long addr, unsigned int order);
 236extern void free_hot_page(struct page *page);
 237extern void free_cold_page(struct page *page);
 238
 239#define __free_page(page) __free_pages((page), 0)
 240#define free_page(addr) free_pages((addr),0)
 241
 242void page_alloc_init(void);
 243void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 244void drain_all_pages(void);
 245void drain_local_pages(void *dummy);
 246
 247#endif /* __LINUX_GFP_H */
 248