LXR linux-bk/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
   9struct 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      0x10    /* Can wait and reschedule? */
  30#define __GFP_HIGH      0x20    /* Should access emergency pools? */
  31#define __GFP_IO        0x40    /* Can start physical IO? */
  32#define __GFP_FS        0x80    /* Can call down to low-level FS? */
  33#define __GFP_COLD      0x100   /* Cache-cold page required */
  34#define __GFP_NOWARN    0x200   /* Suppress page allocation failure warning */
  35#define __GFP_REPEAT    0x400   /* Retry the allocation.  Might fail */
  36#define __GFP_NOFAIL    0x800   /* Retry for ever.  Cannot fail */
  37#define __GFP_NORETRY   0x1000  /* Do not retry.  Might fail */
  38#define __GFP_NO_GROW   0x2000  /* Slab internal usage */
  39#define __GFP_COMP      0x4000  /* Add compound page metadata */
  40
  41#define __GFP_BITS_SHIFT 16     /* Room for 16 __GFP_FOO bits */
  42#define __GFP_BITS_MASK ((1 << __GFP_BITS_SHIFT) - 1)
  43
  44/* if you forget to add the bitmask here kernel will crash, period */
  45#define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
  46                        __GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
  47                        __GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP)
  48
  49#define GFP_ATOMIC      (__GFP_HIGH)
  50#define GFP_NOIO        (__GFP_WAIT)
  51#define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
  52#define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
  53#define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS)
  54#define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HIGHMEM)
  55
  56/* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
  57   platforms, used as appropriate on others */
  58
  59#define GFP_DMA         __GFP_DMA
  60
  61
  62/*
  63 * There is only one page-allocator function, and two main namespaces to
  64 * it. The alloc_page*() variants return 'struct page *' and as such
  65 * can allocate highmem pages, the *get*page*() variants return
  66 * virtual kernel addresses to the allocated page(s).
  67 */
  68
  69/*
  70 * We get the zone list from the current node and the gfp_mask.
  71 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
  72 *
  73 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
  74 * optimized to &contig_page_data at compile-time.
  75 */
  76extern struct page *
  77FASTCALL(__alloc_pages(unsigned int, unsigned int, struct zonelist *));
  78
  79static inline struct page *alloc_pages_node(int nid, unsigned int gfp_mask,
  80                                                unsigned int order)
  81{
  82        if (unlikely(order >= MAX_ORDER))
  83                return NULL;
  84
  85        return __alloc_pages(gfp_mask, order,
  86                NODE_DATA(nid)->node_zonelists + (gfp_mask & GFP_ZONEMASK));
  87}
  88
  89#ifdef CONFIG_NUMA
  90extern struct page *alloc_pages_current(unsigned gfp_mask, unsigned order);
  91
  92static inline struct page *
  93alloc_pages(unsigned int gfp_mask, unsigned int order)
  94{
  95        if (unlikely(order >= MAX_ORDER))
  96                return NULL;
  97
  98        return alloc_pages_current(gfp_mask, order);
  99}
 100extern struct page *alloc_page_vma(unsigned gfp_mask,
 101                        struct vm_area_struct *vma, unsigned long addr);
 102#else
 103#define alloc_pages(gfp_mask, order) \
 104                alloc_pages_node(numa_node_id(), gfp_mask, order)
 105#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
 106#endif
 107#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 108
 109extern unsigned long FASTCALL(__get_free_pages(unsigned int gfp_mask, unsigned int order));
 110extern unsigned long FASTCALL(get_zeroed_page(unsigned int gfp_mask));
 111
 112#define __get_free_page(gfp_mask) \
 113                __get_free_pages((gfp_mask),0)
 114
 115#define __get_dma_pages(gfp_mask, order) \
 116                __get_free_pages((gfp_mask) | GFP_DMA,(order))
 117
 118extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
 119extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
 120extern void FASTCALL(free_hot_page(struct page *page));
 121extern void FASTCALL(free_cold_page(struct page *page));
 122
 123#define __free_page(page) __free_pages((page), 0)
 124#define free_page(addr) free_pages((addr),0)
 125
 126void page_alloc_init(void);
 127
 128#endif /* __LINUX_GFP_H */
 129