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
   9struct vm_area_struct;
  10
  11/*
  12 * GFP bitmasks..
  13 *
  14 * Zone modifiers (see linux/mmzone.h - low three bits)
  15 *
  16 * Do not put any conditional on these. If necessary modify the definitions
  17 * without the underscores and use the consistently. The definitions here may
  18 * be used in bit comparisons.
  19 */
  20#define __GFP_DMA       ((__force gfp_t)0x01u)
  21#define __GFP_HIGHMEM   ((__force gfp_t)0x02u)
  22#define __GFP_DMA32     ((__force gfp_t)0x04u)
  23
  24/*
  25 * Action modifiers - doesn't change the zoning
  26 *
  27 * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  28 * _might_ fail.  This depends upon the particular VM implementation.
  29 *
  30 * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  31 * cannot handle allocation failures.
  32 *
  33 * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  34 *
  35 * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  36 * mechanism or reclaimed
  37 */
  38#define __GFP_WAIT      ((__force gfp_t)0x10u)  /* Can wait and reschedule? */
  39#define __GFP_HIGH      ((__force gfp_t)0x20u)  /* Should access emergency pools? */
  40#define __GFP_IO        ((__force gfp_t)0x40u)  /* Can start physical IO? */
  41#define __GFP_FS        ((__force gfp_t)0x80u)  /* Can call down to low-level FS? */
  42#define __GFP_COLD      ((__force gfp_t)0x100u) /* Cache-cold page required */
  43#define __GFP_NOWARN    ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
  44#define __GFP_REPEAT    ((__force gfp_t)0x400u) /* See above */
  45#define __GFP_NOFAIL    ((__force gfp_t)0x800u) /* See above */
  46#define __GFP_NORETRY   ((__force gfp_t)0x1000u)/* See above */
  47#define __GFP_COMP      ((__force gfp_t)0x4000u)/* Add compound page metadata */
  48#define __GFP_ZERO      ((__force gfp_t)0x8000u)/* Return zeroed page on success */
  49#define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
  50#define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
  51#define __GFP_THISNODE  ((__force gfp_t)0x40000u)/* No fallback, no policies */
  52#define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */
  53#define __GFP_MOVABLE   ((__force gfp_t)0x100000u)  /* Page is movable */
  54
  55#define __GFP_BITS_SHIFT 21     /* Room for 21 __GFP_FOO bits */
  56#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  57
  58/* This equals 0, but use constants in case they ever change */
  59#define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
  60/* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
  61#define GFP_ATOMIC      (__GFP_HIGH)
  62#define GFP_NOIO        (__GFP_WAIT)
  63#define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
  64#define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
  65#define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  66                         __GFP_RECLAIMABLE)
  67#define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
  68#define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
  69                         __GFP_HIGHMEM)
  70#define GFP_HIGHUSER_MOVABLE    (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  71                                 __GFP_HARDWALL | __GFP_HIGHMEM | \
  72                                 __GFP_MOVABLE)
  73
  74#ifdef CONFIG_NUMA
  75#define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  76#else
  77#define GFP_THISNODE    ((__force gfp_t)0)
  78#endif
  79
  80/* This mask makes up all the page movable related flags */
  81#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
  82
  83/* Control page allocator reclaim behavior */
  84#define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
  85                        __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
  86                        __GFP_NORETRY|__GFP_NOMEMALLOC)
  87
  88/* Control allocation constraints */
  89#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
  90
  91/* Do not use these with a slab allocator */
  92#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
  93
  94/* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
  95   platforms, used as appropriate on others */
  96
  97#define GFP_DMA         __GFP_DMA
  98
  99/* 4GB DMA on some platforms */
 100#define GFP_DMA32       __GFP_DMA32
 101
 102/* Convert GFP flags to their corresponding migrate type */
 103static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 104{
 105        WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 106
 107        if (unlikely(page_group_by_mobility_disabled))
 108                return MIGRATE_UNMOVABLE;
 109
 110        /* Group based on mobility */
 111        return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 112                ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 113}
 114
 115static inline enum zone_type gfp_zone(gfp_t flags)
 116{
 117#ifdef CONFIG_ZONE_DMA
 118        if (flags & __GFP_DMA)
 119                return ZONE_DMA;
 120#endif
 121#ifdef CONFIG_ZONE_DMA32
 122        if (flags & __GFP_DMA32)
 123                return ZONE_DMA32;
 124#endif
 125        if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
 126                        (__GFP_HIGHMEM | __GFP_MOVABLE))
 127                return ZONE_MOVABLE;
 128#ifdef CONFIG_HIGHMEM
 129        if (flags & __GFP_HIGHMEM)
 130                return ZONE_HIGHMEM;
 131#endif
 132        return ZONE_NORMAL;
 133}
 134
 135/*
 136 * There is only one page-allocator function, and two main namespaces to
 137 * it. The alloc_page*() variants return 'struct page *' and as such
 138 * can allocate highmem pages, the *get*page*() variants return
 139 * virtual kernel addresses to the allocated page(s).
 140 */
 141
 142static inline int gfp_zonelist(gfp_t flags)
 143{
 144        if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
 145                return 1;
 146
 147        return 0;
 148}
 149
 150/*
 151 * We get the zone list from the current node and the gfp_mask.
 152 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 153 * There are two zonelists per node, one for all zones with memory and
 154 * one containing just zones from the node the zonelist belongs to.
 155 *
 156 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 157 * optimized to &contig_page_data at compile-time.
 158 */
 159static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 160{
 161        return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 162}
 163
 164#ifndef HAVE_ARCH_FREE_PAGE
 165static inline void arch_free_page(struct page *page, int order) { }
 166#endif
 167#ifndef HAVE_ARCH_ALLOC_PAGE
 168static inline void arch_alloc_page(struct page *page, int order) { }
 169#endif
 170
 171struct page *
 172__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
 173                       struct zonelist *zonelist, nodemask_t *nodemask);
 174
 175static inline struct page *
 176__alloc_pages(gfp_t gfp_mask, unsigned int order,
 177                struct zonelist *zonelist)
 178{
 179        return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
 180}
 181
 182static inline struct page *
 183__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 184                struct zonelist *zonelist, nodemask_t *nodemask)
 185{
 186        return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
 187}
 188
 189
 190static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 191                                                unsigned int order)
 192{
 193        if (unlikely(order >= MAX_ORDER))
 194                return NULL;
 195
 196        /* Unknown node is current node */
 197        if (nid < 0)
 198                nid = numa_node_id();
 199
 200        return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 201}
 202
 203#ifdef CONFIG_NUMA
 204extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 205
 206static inline struct page *
 207alloc_pages(gfp_t gfp_mask, unsigned int order)
 208{
 209        if (unlikely(order >= MAX_ORDER))
 210                return NULL;
 211
 212        return alloc_pages_current(gfp_mask, order);
 213}
 214extern struct page *alloc_page_vma(gfp_t gfp_mask,
 215                        struct vm_area_struct *vma, unsigned long addr);
 216#else
 217#define alloc_pages(gfp_mask, order) \
 218                alloc_pages_node(numa_node_id(), gfp_mask, order)
 219#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 220#endif
 221#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 222
 223extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 224extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 225
 226void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 227void free_pages_exact(void *virt, size_t size);
 228
 229#define __get_free_page(gfp_mask) \
 230                __get_free_pages((gfp_mask),0)
 231
 232#define __get_dma_pages(gfp_mask, order) \
 233                __get_free_pages((gfp_mask) | GFP_DMA,(order))
 234
 235extern void __free_pages(struct page *page, unsigned int order);
 236extern void free_pages(unsigned long addr, unsigned int order);
 237extern void free_hot_page(struct page *page);
 238extern void free_cold_page(struct page *page);
 239
 240#define __free_page(page) __free_pages((page), 0)
 241#define free_page(addr) free_pages((addr),0)
 242
 243void page_alloc_init(void);
 244void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 245void drain_all_pages(void);
 246void drain_local_pages(void *dummy);
 247
 248#endif /* __LINUX_GFP_H */
 249