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
   8 struct 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 #define __GFP_WAIT      ((__force gfp_t)0x10u)  /* Can wait and reschedule? */
  35 #define __GFP_HIGH      ((__force gfp_t)0x20u)  /* Should access emergency pools? */
  36 #define __GFP_IO        ((__force gfp_t)0x40u)  /* Can start physical IO? */
  37 #define __GFP_FS        ((__force gfp_t)0x80u)  /* Can call down to low-level FS? */
  38 #define __GFP_COLD      ((__force gfp_t)0x100u) /* Cache-cold page required */
  39 #define __GFP_NOWARN    ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
  40 #define __GFP_REPEAT    ((__force gfp_t)0x400u) /* Retry the allocation.  Might fail */
  41 #define __GFP_NOFAIL    ((__force gfp_t)0x800u) /* Retry for ever.  Cannot fail */
  42 #define __GFP_NORETRY   ((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
  43 #define __GFP_COMP      ((__force gfp_t)0x4000u)/* Add compound page metadata */
  44 #define __GFP_ZERO      ((__force gfp_t)0x8000u)/* Return zeroed page on success */
  45 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
  46 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
  47 #define __GFP_THISNODE  ((__force gfp_t)0x40000u)/* No fallback, no policies */
  48
  49 #define __GFP_BITS_SHIFT 20     /* Room for 20 __GFP_FOO bits */
  50 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  51
  52 /* if you forget to add the bitmask here kernel will crash, period */
  53 #define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
  54                         __GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
  55                         __GFP_NOFAIL|__GFP_NORETRY|__GFP_COMP| \
  56                         __GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE)
  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_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
  66 #define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
  67                          __GFP_HIGHMEM)
  68
  69 #ifdef CONFIG_NUMA
  70 #define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  71 #else
  72 #define GFP_THISNODE    ((__force gfp_t)0)
  73 #endif
  74
  75
  76 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
  77    platforms, used as appropriate on others */
  78
  79 #define GFP_DMA         __GFP_DMA
  80
  81 /* 4GB DMA on some platforms */
  82 #define GFP_DMA32       __GFP_DMA32
  83
  84
  85 static inline enum zone_type gfp_zone(gfp_t flags)
  86 {
  87 #ifdef CONFIG_ZONE_DMA
  88         if (flags & __GFP_DMA)
  89                 return ZONE_DMA;
  90 #endif
  91 #ifdef CONFIG_ZONE_DMA32
  92         if (flags & __GFP_DMA32)
  93                 return ZONE_DMA32;
  94 #endif
  95 #ifdef CONFIG_HIGHMEM
  96         if (flags & __GFP_HIGHMEM)
  97                 return ZONE_HIGHMEM;
  98 #endif
  99         return ZONE_NORMAL;
 100 }
 101
 102 /*
 103  * There is only one page-allocator function, and two main namespaces to
 104  * it. The alloc_page*() variants return 'struct page *' and as such
 105  * can allocate highmem pages, the *get*page*() variants return
 106  * virtual kernel addresses to the allocated page(s).
 107  */
 108
 109 /*
 110  * We get the zone list from the current node and the gfp_mask.
 111  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 112  *
 113  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 114  * optimized to &contig_page_data at compile-time.
 115  */
 116
 117 #ifndef HAVE_ARCH_FREE_PAGE
 118 static inline void arch_free_page(struct page *page, int order) { }
 119 #endif
 120 #ifndef HAVE_ARCH_ALLOC_PAGE
 121 static inline void arch_alloc_page(struct page *page, int order) { }
 122 #endif
 123
 124 extern struct page *
 125 FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
 126
 127 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 128                                                 unsigned int order)
 129 {
 130         if (unlikely(order >= MAX_ORDER))
 131                 return NULL;
 132
 133         /* Unknown node is current node */
 134         if (nid < 0)
 135                 nid = numa_node_id();
 136
 137         return __alloc_pages(gfp_mask, order,
 138                 NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
 139 }
 140
 141 #ifdef CONFIG_NUMA
 142 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 143
 144 static inline struct page *
 145 alloc_pages(gfp_t gfp_mask, unsigned int order)
 146 {
 147         if (unlikely(order >= MAX_ORDER))
 148                 return NULL;
 149
 150         return alloc_pages_current(gfp_mask, order);
 151 }
 152 extern struct page *alloc_page_vma(gfp_t gfp_mask,
 153                         struct vm_area_struct *vma, unsigned long addr);
 154 #else
 155 #define alloc_pages(gfp_mask, order) \
 156                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 157 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 158 #endif
 159 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 160
 161 extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
 162 extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
 163
 164 #define __get_free_page(gfp_mask) \
 165                 __get_free_pages((gfp_mask),0)
 166
 167 #define __get_dma_pages(gfp_mask, order) \
 168                 __get_free_pages((gfp_mask) | GFP_DMA,(order))
 169
 170 extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
 171 extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
 172 extern void FASTCALL(free_hot_page(struct page *page));
 173 extern void FASTCALL(free_cold_page(struct page *page));
 174
 175 #define __free_page(page) __free_pages((page), 0)
 176 #define free_page(addr) free_pages((addr),0)
 177
 178 void page_alloc_init(void);
 179 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 180
 181 #endif /* __LINUX_GFP_H */