Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
8struct 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 * __GFP_MOVABLE: Flag that this page will be movable by the page migration
35 * mechanism or reclaimed
36 */
37#define __GFP_WAIT ((__force gfp_t)0x10u) /* Can wait and reschedule? */
38#define __GFP_HIGH ((__force gfp_t)0x20u) /* Should access emergency pools? */
39#define __GFP_IO ((__force gfp_t)0x40u) /* Can start physical IO? */
40#define __GFP_FS ((__force gfp_t)0x80u) /* Can call down to low-level FS? */
41#define __GFP_COLD ((__force gfp_t)0x100u) /* Cache-cold page required */
42#define __GFP_NOWARN ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
43#define __GFP_REPEAT ((__force gfp_t)0x400u) /* Retry the allocation. Might fail */
44#define __GFP_NOFAIL ((__force gfp_t)0x800u) /* Retry for ever. Cannot fail */
45#define __GFP_NORETRY ((__force gfp_t)0x1000u)/* Do not retry. Might fail */
46#define __GFP_COMP ((__force gfp_t)0x4000u)/* Add compound page metadata */
47#define __GFP_ZERO ((__force gfp_t)0x8000u)/* Return zeroed page on success */
48#define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
49#define __GFP_HARDWALL ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
50#define __GFP_THISNODE ((__force gfp_t)0x40000u)/* No fallback, no policies */
51#define __GFP_MOVABLE ((__force gfp_t)0x80000u) /* Page is movable */
52
53#define __GFP_BITS_SHIFT 20 /* Room for 20 __GFP_FOO bits */
54#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
55
56/* if you forget to add the bitmask here kernel will crash, period */
57#define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
58 __GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
59 __GFP_NOFAIL|__GFP_NORETRY|__GFP_COMP| \
60 __GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE| \
61 __GFP_MOVABLE)
62
63/* This equals 0, but use constants in case they ever change */
64#define GFP_NOWAIT (GFP_ATOMIC & ~__GFP_HIGH)
65/* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
66#define GFP_ATOMIC (__GFP_HIGH)
67#define GFP_NOIO (__GFP_WAIT)
68#define GFP_NOFS (__GFP_WAIT | __GFP_IO)
69#define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)
70#define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
71#define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
72 __GFP_HIGHMEM)
73#define GFP_HIGHUSER_MOVABLE (__GFP_WAIT | __GFP_IO | __GFP_FS | \
74 __GFP_HARDWALL | __GFP_HIGHMEM | \
75 __GFP_MOVABLE)
76#define GFP_NOFS_PAGECACHE (__GFP_WAIT | __GFP_IO | __GFP_MOVABLE)
77#define GFP_USER_PAGECACHE (__GFP_WAIT | __GFP_IO | __GFP_FS | \
78 __GFP_HARDWALL | __GFP_MOVABLE)
79#define GFP_HIGHUSER_PAGECACHE (__GFP_WAIT | __GFP_IO | __GFP_FS | \
80 __GFP_HARDWALL | __GFP_HIGHMEM | \
81 __GFP_MOVABLE)
82
83#ifdef CONFIG_NUMA
84#define GFP_THISNODE (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
85#else
86#define GFP_THISNODE ((__force gfp_t)0)
87#endif
88
89
90/* Flag - indicates that the buffer will be suitable for DMA. Ignored on some
91 platforms, used as appropriate on others */
92
93#define GFP_DMA __GFP_DMA
94
95/* 4GB DMA on some platforms */
96#define GFP_DMA32 __GFP_DMA32
97
98
99static inline enum zone_type gfp_zone(gfp_t flags)
100{
101#ifdef CONFIG_ZONE_DMA
102 if (flags & __GFP_DMA)
103 return ZONE_DMA;
104#endif
105#ifdef CONFIG_ZONE_DMA32
106 if (flags & __GFP_DMA32)
107 return ZONE_DMA32;
108#endif
109 if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
110 (__GFP_HIGHMEM | __GFP_MOVABLE))
111 return ZONE_MOVABLE;
112#ifdef CONFIG_HIGHMEM
113 if (flags & __GFP_HIGHMEM)
114 return ZONE_HIGHMEM;
115#endif
116 return ZONE_NORMAL;
117}
118
119/*
120 * There is only one page-allocator function, and two main namespaces to
121 * it. The alloc_page*() variants return 'struct page *' and as such
122 * can allocate highmem pages, the *get*page*() variants return
123 * virtual kernel addresses to the allocated page(s).
124 */
125
126/*
127 * We get the zone list from the current node and the gfp_mask.
128 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
129 *
130 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
131 * optimized to &contig_page_data at compile-time.
132 */
133
134#ifndef HAVE_ARCH_FREE_PAGE
135static inline void arch_free_page(struct page *page, int order) { }
136#endif
137#ifndef HAVE_ARCH_ALLOC_PAGE
138static inline void arch_alloc_page(struct page *page, int order) { }
139#endif
140
141extern struct page *
142FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
143
144static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
145 unsigned int order)
146{
147 if (unlikely(order >= MAX_ORDER))
148 return NULL;
149
150 /* Unknown node is current node */
151 if (nid < 0)
152 nid = numa_node_id();
153
154 return __alloc_pages(gfp_mask, order,
155 NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
156}
157
158#ifdef CONFIG_NUMA
159extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
160
161static inline struct page *
162alloc_pages(gfp_t gfp_mask, unsigned int order)
163{
164 if (unlikely(order >= MAX_ORDER))
165 return NULL;
166
167 return alloc_pages_current(gfp_mask, order);
168}
169extern struct page *alloc_page_vma(gfp_t gfp_mask,
170 struct vm_area_struct *vma, unsigned long addr);
171#else
172#define alloc_pages(gfp_mask, order) \
173 alloc_pages_node(numa_node_id(), gfp_mask, order)
174#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
175#endif
176#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
177
178extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
179extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
180
181#define __get_free_page(gfp_mask) \
182 __get_free_pages((gfp_mask),0)
183
184#define __get_dma_pages(gfp_mask, order) \
185 __get_free_pages((gfp_mask) | GFP_DMA,(order))
186
187extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
188extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
189extern void FASTCALL(free_hot_page(struct page *page));
190extern void FASTCALL(free_cold_page(struct page *page));
191
192#define __free_page(page) __free_pages((page), 0)
193#define free_page(addr) free_pages((addr),0)
194
195void page_alloc_init(void);
196void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
197
198#endif /* __LINUX_GFP_H */