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/config.h>
   8
   9 struct vm_area_struct;
  10
  11 /*
  12  * GFP bitmasks..
  13  */
  14 /* Zone modifiers in GFP_ZONEMASK (see linux/mmzone.h - low two bits) */
  15 #define __GFP_DMA       0x01
  16 #define __GFP_HIGHMEM   0x02
  17
  18 /*
  19  * Action modifiers - doesn't change the zoning
  20  *
  21  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  22  * _might_ fail.  This depends upon the particular VM implementation.
  23  *
  24  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  25  * cannot handle allocation failures.
  26  *
  27  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  28  */
  29 #define __GFP_WAIT      0x10u   /* Can wait and reschedule? */
  30 #define __GFP_HIGH      0x20u   /* Should access emergency pools? */
  31 #define __GFP_IO        0x40u   /* Can start physical IO? */
  32 #define __GFP_FS        0x80u   /* Can call down to low-level FS? */
  33 #define __GFP_COLD      0x100u  /* Cache-cold page required */
  34 #define __GFP_NOWARN    0x200u  /* Suppress page allocation failure warning */
  35 #define __GFP_REPEAT    0x400u  /* Retry the allocation.  Might fail */
  36 #define __GFP_NOFAIL    0x800u  /* Retry for ever.  Cannot fail */
  37 #define __GFP_NORETRY   0x1000u /* Do not retry.  Might fail */
  38 #define __GFP_NO_GROW   0x2000u /* Slab internal usage */
  39 #define __GFP_COMP      0x4000u /* Add compound page metadata */
  40 #define __GFP_ZERO      0x8000u /* Return zeroed page on success */
  41 #define __GFP_NOMEMALLOC 0x10000u /* Don't use emergency reserves */
  42
  43 #define __GFP_BITS_SHIFT 20     /* Room for 20 __GFP_FOO bits */
  44 #define __GFP_BITS_MASK ((1 << __GFP_BITS_SHIFT) - 1)
  45
  46 /* if you forget to add the bitmask here kernel will crash, period */
  47 #define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
  48                         __GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
  49                         __GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
  50                         __GFP_NOMEMALLOC)
  51
  52 #define GFP_ATOMIC      (__GFP_HIGH)
  53 #define GFP_NOIO        (__GFP_WAIT)
  54 #define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
  55 #define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
  56 #define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS)
  57 #define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HIGHMEM)
  58
  59 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
  60    platforms, used as appropriate on others */
  61
  62 #define GFP_DMA         __GFP_DMA
  63
  64
  65 /*
  66  * There is only one page-allocator function, and two main namespaces to
  67  * it. The alloc_page*() variants return 'struct page *' and as such
  68  * can allocate highmem pages, the *get*page*() variants return
  69  * virtual kernel addresses to the allocated page(s).
  70  */
  71
  72 /*
  73  * We get the zone list from the current node and the gfp_mask.
  74  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
  75  *
  76  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
  77  * optimized to &contig_page_data at compile-time.
  78  */
  79
  80 #ifndef HAVE_ARCH_FREE_PAGE
  81 static inline void arch_free_page(struct page *page, int order) { }
  82 #endif
  83
  84 extern struct page *
  85 FASTCALL(__alloc_pages(unsigned int, unsigned int, struct zonelist *));
  86
  87 static inline struct page *alloc_pages_node(int nid, unsigned int __nocast gfp_mask,
  88                                                 unsigned int order)
  89 {
  90         if (unlikely(order >= MAX_ORDER))
  91                 return NULL;
  92
  93         return __alloc_pages(gfp_mask, order,
  94                 NODE_DATA(nid)->node_zonelists + (gfp_mask & GFP_ZONEMASK));
  95 }
  96
  97 #ifdef CONFIG_NUMA
  98 extern struct page *alloc_pages_current(unsigned int __nocast gfp_mask, unsigned order);
  99
 100 static inline struct page *
 101 alloc_pages(unsigned int __nocast gfp_mask, unsigned int order)
 102 {
 103         if (unlikely(order >= MAX_ORDER))
 104                 return NULL;
 105
 106         return alloc_pages_current(gfp_mask, order);
 107 }
 108 extern struct page *alloc_page_vma(unsigned __nocast gfp_mask,
 109                         struct vm_area_struct *vma, unsigned long addr);
 110 #else
 111 #define alloc_pages(gfp_mask, order) \
 112                 alloc_pages_node(numa_node_id(), gfp_mask, order)
 113 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 114 #endif
 115 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 116
 117 extern unsigned long FASTCALL(__get_free_pages(unsigned int __nocast gfp_mask, unsigned int order));
 118 extern unsigned long FASTCALL(get_zeroed_page(unsigned int __nocast gfp_mask));
 119
 120 #define __get_free_page(gfp_mask) \
 121                 __get_free_pages((gfp_mask),0)
 122
 123 #define __get_dma_pages(gfp_mask, order) \
 124                 __get_free_pages((gfp_mask) | GFP_DMA,(order))
 125
 126 extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
 127 extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
 128 extern void FASTCALL(free_hot_page(struct page *page));
 129 extern void FASTCALL(free_cold_page(struct page *page));
 130
 131 #define __free_page(page) __free_pages((page), 0)
 132 #define free_page(addr) free_pages((addr),0)
 133
 134 void page_alloc_init(void);
 135
 136 #endif /* __LINUX_GFP_H */