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      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 in GFP_ZONEMASK (see linux/mmzone.h - low three bits) */
     14 #define __GFP_DMA	((__force gfp_t)0x01u)
     15 #define __GFP_HIGHMEM	((__force gfp_t)0x02u)
     16 #ifdef CONFIG_DMA_IS_DMA32
     17 #define __GFP_DMA32	((__force gfp_t)0x01)	/* ZONE_DMA is ZONE_DMA32 */
     18 #elif BITS_PER_LONG < 64
     19 #define __GFP_DMA32	((__force gfp_t)0x00)	/* ZONE_NORMAL is ZONE_DMA32 */
     20 #else
     21 #define __GFP_DMA32	((__force gfp_t)0x04)	/* Has own ZONE_DMA32 */
     22 #endif
     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 #define __GFP_WAIT	((__force gfp_t)0x10u)	/* Can wait and reschedule? */
     36 #define __GFP_HIGH	((__force gfp_t)0x20u)	/* Should access emergency pools? */
     37 #define __GFP_IO	((__force gfp_t)0x40u)	/* Can start physical IO? */
     38 #define __GFP_FS	((__force gfp_t)0x80u)	/* Can call down to low-level FS? */
     39 #define __GFP_COLD	((__force gfp_t)0x100u)	/* Cache-cold page required */
     40 #define __GFP_NOWARN	((__force gfp_t)0x200u)	/* Suppress page allocation failure warning */
     41 #define __GFP_REPEAT	((__force gfp_t)0x400u)	/* Retry the allocation.  Might fail */
     42 #define __GFP_NOFAIL	((__force gfp_t)0x800u)	/* Retry for ever.  Cannot fail */
     43 #define __GFP_NORETRY	((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
     44 #define __GFP_NO_GROW	((__force gfp_t)0x2000u)/* Slab internal usage */
     45 #define __GFP_COMP	((__force gfp_t)0x4000u)/* Add compound page metadata */
     46 #define __GFP_ZERO	((__force gfp_t)0x8000u)/* Return zeroed page on success */
     47 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
     48 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
     49 
     50 #define __GFP_BITS_SHIFT 20	/* Room for 20 __GFP_FOO bits */
     51 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
     52 
     53 /* if you forget to add the bitmask here kernel will crash, period */
     54 #define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
     55 			__GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
     56 			__GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
     57 			__GFP_NOMEMALLOC|__GFP_HARDWALL)
     58 
     59 /* This equals 0, but use constants in case they ever change */
     60 #define GFP_NOWAIT	(GFP_ATOMIC & ~__GFP_HIGH)
     61 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
     62 #define GFP_ATOMIC	(__GFP_HIGH)
     63 #define GFP_NOIO	(__GFP_WAIT)
     64 #define GFP_NOFS	(__GFP_WAIT | __GFP_IO)
     65 #define GFP_KERNEL	(__GFP_WAIT | __GFP_IO | __GFP_FS)
     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 
     70 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
     71    platforms, used as appropriate on others */
     72 
     73 #define GFP_DMA		__GFP_DMA
     74 
     75 /* 4GB DMA on some platforms */
     76 #define GFP_DMA32	__GFP_DMA32
     77 
     78 
     79 static inline int gfp_zone(gfp_t gfp)
     80 {
     81 	int zone = GFP_ZONEMASK & (__force int) gfp;
     82 	BUG_ON(zone >= GFP_ZONETYPES);
     83 	return zone;
     84 }
     85 
     86 /*
     87  * There is only one page-allocator function, and two main namespaces to
     88  * it. The alloc_page*() variants return 'struct page *' and as such
     89  * can allocate highmem pages, the *get*page*() variants return
     90  * virtual kernel addresses to the allocated page(s).
     91  */
     92 
     93 /*
     94  * We get the zone list from the current node and the gfp_mask.
     95  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
     96  *
     97  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
     98  * optimized to &contig_page_data at compile-time.
     99  */
    100 
    101 #ifndef HAVE_ARCH_FREE_PAGE
    102 static inline void arch_free_page(struct page *page, int order) { }
    103 #endif
    104 
    105 extern struct page *
    106 FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
    107 
    108 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
    109 						unsigned int order)
    110 {
    111 	if (unlikely(order >= MAX_ORDER))
    112 		return NULL;
    113 
    114 	/* Unknown node is current node */
    115 	if (nid < 0)
    116 		nid = numa_node_id();
    117 
    118 	return __alloc_pages(gfp_mask, order,
    119 		NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
    120 }
    121 
    122 #ifdef CONFIG_NUMA
    123 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
    124 
    125 static inline struct page *
    126 alloc_pages(gfp_t gfp_mask, unsigned int order)
    127 {
    128 	if (unlikely(order >= MAX_ORDER))
    129 		return NULL;
    130 
    131 	return alloc_pages_current(gfp_mask, order);
    132 }
    133 extern struct page *alloc_page_vma(gfp_t gfp_mask,
    134 			struct vm_area_struct *vma, unsigned long addr);
    135 #else
    136 #define alloc_pages(gfp_mask, order) \
    137 		alloc_pages_node(numa_node_id(), gfp_mask, order)
    138 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
    139 #endif
    140 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
    141 
    142 extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
    143 extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
    144 
    145 #define __get_free_page(gfp_mask) \
    146 		__get_free_pages((gfp_mask),0)
    147 
    148 #define __get_dma_pages(gfp_mask, order) \
    149 		__get_free_pages((gfp_mask) | GFP_DMA,(order))
    150 
    151 extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
    152 extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
    153 extern void FASTCALL(free_hot_page(struct page *page));
    154 extern void FASTCALL(free_cold_page(struct page *page));
    155 
    156 #define __free_page(page) __free_pages((page), 0)
    157 #define free_page(addr) free_pages((addr),0)
    158 
    159 void page_alloc_init(void);
    160 #ifdef CONFIG_NUMA
    161 void drain_node_pages(int node);
    162 #else
    163 static inline void drain_node_pages(int node) { };
    164 #endif
    165 
    166 #endif /* __LINUX_GFP_H */
    167