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) /* Retry the allocation.  Might fail */
  44#define __GFP_NOFAIL    ((__force gfp_t)0x800u) /* Retry for ever.  Cannot fail */
  45#define __GFP_NORETRY   ((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
  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#define GFP_NOFS_PAGECACHE      (__GFP_WAIT | __GFP_IO | __GFP_MOVABLE)
  73#define GFP_USER_PAGECACHE      (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  74                                 __GFP_HARDWALL | __GFP_MOVABLE)
  75#define GFP_HIGHUSER_PAGECACHE  (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  76                                 __GFP_HARDWALL | __GFP_HIGHMEM | \
  77                                 __GFP_MOVABLE)
  78
  79#ifdef CONFIG_NUMA
  80#define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  81#else
  82#define GFP_THISNODE    ((__force gfp_t)0)
  83#endif
  84
  85/* This mask makes up all the page movable related flags */
  86#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
  87
  88/* Control page allocator reclaim behavior */
  89#define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
  90                        __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
  91                        __GFP_NORETRY|__GFP_NOMEMALLOC)
  92
  93/* Control allocation constraints */
  94#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
  95
  96/* Do not use these with a slab allocator */
  97#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
  98
  99/* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 100   platforms, used as appropriate on others */
 101
 102#define GFP_DMA         __GFP_DMA
 103
 104/* 4GB DMA on some platforms */
 105#define GFP_DMA32       __GFP_DMA32
 106
 107/* Convert GFP flags to their corresponding migrate type */
 108static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 109{
 110        WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 111
 112        if (unlikely(page_group_by_mobility_disabled))
 113                return MIGRATE_UNMOVABLE;
 114
 115        /* Group based on mobility */
 116        return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 117                ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 118}
 119
 120static inline enum zone_type gfp_zone(gfp_t flags)
 121{
 122        int base = 0;
 123
 124#ifdef CONFIG_NUMA
 125        if (flags & __GFP_THISNODE)
 126                base = MAX_NR_ZONES;
 127#endif
 128
 129#ifdef CONFIG_ZONE_DMA
 130        if (flags & __GFP_DMA)
 131                return base + ZONE_DMA;
 132#endif
 133#ifdef CONFIG_ZONE_DMA32
 134        if (flags & __GFP_DMA32)
 135                return base + ZONE_DMA32;
 136#endif
 137        if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
 138                        (__GFP_HIGHMEM | __GFP_MOVABLE))
 139                return base + ZONE_MOVABLE;
 140#ifdef CONFIG_HIGHMEM
 141        if (flags & __GFP_HIGHMEM)
 142                return base + ZONE_HIGHMEM;
 143#endif
 144        return base + ZONE_NORMAL;
 145}
 146
 147static inline gfp_t set_migrateflags(gfp_t gfp, gfp_t migrate_flags)
 148{
 149        BUG_ON((gfp & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 150        return (gfp & ~(GFP_MOVABLE_MASK)) | migrate_flags;
 151}
 152
 153/*
 154 * There is only one page-allocator function, and two main namespaces to
 155 * it. The alloc_page*() variants return 'struct page *' and as such
 156 * can allocate highmem pages, the *get*page*() variants return
 157 * virtual kernel addresses to the allocated page(s).
 158 */
 159
 160/*
 161 * We get the zone list from the current node and the gfp_mask.
 162 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 163 *
 164 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 165 * optimized to &contig_page_data at compile-time.
 166 */
 167
 168#ifndef HAVE_ARCH_FREE_PAGE
 169static inline void arch_free_page(struct page *page, int order) { }
 170#endif
 171#ifndef HAVE_ARCH_ALLOC_PAGE
 172static inline void arch_alloc_page(struct page *page, int order) { }
 173#endif
 174
 175extern struct page *__alloc_pages(gfp_t, unsigned int, struct zonelist *);
 176
 177static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 178                                                unsigned int order)
 179{
 180        if (unlikely(order >= MAX_ORDER))
 181                return NULL;
 182
 183        /* Unknown node is current node */
 184        if (nid < 0)
 185                nid = numa_node_id();
 186
 187        return __alloc_pages(gfp_mask, order,
 188                NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
 189}
 190
 191#ifdef CONFIG_NUMA
 192extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 193
 194static inline struct page *
 195alloc_pages(gfp_t gfp_mask, unsigned int order)
 196{
 197        if (unlikely(order >= MAX_ORDER))
 198                return NULL;
 199
 200        return alloc_pages_current(gfp_mask, order);
 201}
 202extern struct page *alloc_page_vma(gfp_t gfp_mask,
 203                        struct vm_area_struct *vma, unsigned long addr);
 204#else
 205#define alloc_pages(gfp_mask, order) \
 206                alloc_pages_node(numa_node_id(), gfp_mask, order)
 207#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 208#endif
 209#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 210
 211extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 212extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 213
 214#define __get_free_page(gfp_mask) \
 215                __get_free_pages((gfp_mask),0)
 216
 217#define __get_dma_pages(gfp_mask, order) \
 218                __get_free_pages((gfp_mask) | GFP_DMA,(order))
 219
 220extern void __free_pages(struct page *page, unsigned int order);
 221extern void free_pages(unsigned long addr, unsigned int order);
 222extern void free_hot_page(struct page *page);
 223extern void free_cold_page(struct page *page);
 224
 225#define __free_page(page) __free_pages((page), 0)
 226#define free_page(addr) free_pages((addr),0)
 227
 228void page_alloc_init(void);
 229void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 230void drain_all_pages(void);
 231void drain_local_pages(void *dummy);
 232
 233#endif /* __LINUX_GFP_H */
 234