aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/gfp.h
blob: bc68dd9a6d41f8035fa9d1f0dcc27578085fe1b5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
#ifndef __LINUX_GFP_H
#define __LINUX_GFP_H

#include <linux/mmzone.h>
#include <linux/stddef.h>
#include <linux/linkage.h>

struct vm_area_struct;

/*
 * GFP bitmasks..
 *
 * Zone modifiers (see linux/mmzone.h - low three bits)
 *
 * Do not put any conditional on these. If necessary modify the definitions
 * without the underscores and use the consistently. The definitions here may
 * be used in bit comparisons.
 */
#define __GFP_DMA	((__force gfp_t)0x01u)
#define __GFP_HIGHMEM	((__force gfp_t)0x02u)
#define __GFP_DMA32	((__force gfp_t)0x04u)

/*
 * Action modifiers - doesn't change the zoning
 *
 * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
 * _might_ fail.  This depends upon the particular VM implementation.
 *
 * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
 * cannot handle allocation failures.
 *
 * __GFP_NORETRY: The VM implementation must not retry indefinitely.
 *
 * __GFP_MOVABLE: Flag that this page will be movable by the page migration
 * mechanism or reclaimed
 */
#define __GFP_WAIT	((__force gfp_t)0x10u)	/* Can wait and reschedule? */
#define __GFP_HIGH	((__force gfp_t)0x20u)	/* Should access emergency pools? */
#define __GFP_IO	((__force gfp_t)0x40u)	/* Can start physical IO? */
#define __GFP_FS	((__force gfp_t)0x80u)	/* Can call down to low-level FS? */
#define __GFP_COLD	((__force gfp_t)0x100u)	/* Cache-cold page required */
#define __GFP_NOWARN	((__force gfp_t)0x200u)	/* Suppress page allocation failure warning */
#define __GFP_REPEAT	((__force gfp_t)0x400u)	/* Retry the allocation.  Might fail */
#define __GFP_NOFAIL	((__force gfp_t)0x800u)	/* Retry for ever.  Cannot fail */
#define __GFP_NORETRY	((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
#define __GFP_COMP	((__force gfp_t)0x4000u)/* Add compound page metadata */
#define __GFP_ZERO	((__force gfp_t)0x8000u)/* Return zeroed page on success */
#define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
#define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
#define __GFP_THISNODE	((__force gfp_t)0x40000u)/* No fallback, no policies */
#define __GFP_MOVABLE	((__force gfp_t)0x80000u) /* Page is movable */

#define __GFP_BITS_SHIFT 20	/* Room for 20 __GFP_FOO bits */
#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))

/* if you forget to add the bitmask here kernel will crash, period */
#define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
			__GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
			__GFP_NOFAIL|__GFP_NORETRY|__GFP_COMP| \
			__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE| \
			__GFP_MOVABLE)

/* This equals 0, but use constants in case they ever change */
#define GFP_NOWAIT	(GFP_ATOMIC & ~__GFP_HIGH)
/* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
#define GFP_ATOMIC	(__GFP_HIGH)
#define GFP_NOIO	(__GFP_WAIT)
#define GFP_NOFS	(__GFP_WAIT | __GFP_IO)
#define GFP_KERNEL	(__GFP_WAIT | __GFP_IO | __GFP_FS)
#define GFP_USER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
#define GFP_HIGHUSER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
			 __GFP_HIGHMEM)
#define GFP_HIGHUSER_MOVABLE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
				 __GFP_HARDWALL | __GFP_HIGHMEM | \
				 __GFP_MOVABLE)
#define GFP_NOFS_PAGECACHE	(__GFP_WAIT | __GFP_IO | __GFP_MOVABLE)
#define GFP_USER_PAGECACHE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
				 __GFP_HARDWALL | __GFP_MOVABLE)
#define GFP_HIGHUSER_PAGECACHE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
				 __GFP_HARDWALL | __GFP_HIGHMEM | \
				 __GFP_MOVABLE)

#ifdef CONFIG_NUMA
#define GFP_THISNODE	(__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
#else
#define GFP_THISNODE	((__force gfp_t)0)
#endif


/* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
   platforms, used as appropriate on others */

#define GFP_DMA		__GFP_DMA

/* 4GB DMA on some platforms */
#define GFP_DMA32	__GFP_DMA32


static inline enum zone_type gfp_zone(gfp_t flags)
{
#ifdef CONFIG_ZONE_DMA
	if (flags & __GFP_DMA)
		return ZONE_DMA;
#endif
#ifdef CONFIG_ZONE_DMA32
	if (flags & __GFP_DMA32)
		return ZONE_DMA32;
#endif
	if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
			(__GFP_HIGHMEM | __GFP_MOVABLE))
		return ZONE_MOVABLE;
#ifdef CONFIG_HIGHMEM
	if (flags & __GFP_HIGHMEM)
		return ZONE_HIGHMEM;
#endif
	return ZONE_NORMAL;
}

/*
 * There is only one page-allocator function, and two main namespaces to
 * it. The alloc_page*() variants return 'struct page *' and as such
 * can allocate highmem pages, the *get*page*() variants return
 * virtual kernel addresses to the allocated page(s).
 */

/*
 * We get the zone list from the current node and the gfp_mask.
 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 *
 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 * optimized to &contig_page_data at compile-time.
 */

#ifndef HAVE_ARCH_FREE_PAGE
static inline void arch_free_page(struct page *page, int order) { }
#endif
#ifndef HAVE_ARCH_ALLOC_PAGE
static inline void arch_alloc_page(struct page *page, int order) { }
#endif

extern struct page *
FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));

static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
						unsigned int order)
{
	if (unlikely(order >= MAX_ORDER))
		return NULL;

	/* Unknown node is current node */
	if (nid < 0)
		nid = numa_node_id();

	return __alloc_pages(gfp_mask, order,
		NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
}

#ifdef CONFIG_NUMA
extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);

static inline struct page *
alloc_pages(gfp_t gfp_mask, unsigned int order)
{
	if (unlikely(order >= MAX_ORDER))
		return NULL;

	return alloc_pages_current(gfp_mask, order);
}
extern struct page *alloc_page_vma(gfp_t gfp_mask,
			struct vm_area_struct *vma, unsigned long addr);
#else
#define alloc_pages(gfp_mask, order) \
		alloc_pages_node(numa_node_id(), gfp_mask, order)
#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
#endif
#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)

extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));

#define __get_free_page(gfp_mask) \
		__get_free_pages((gfp_mask),0)

#define __get_dma_pages(gfp_mask, order) \
		__get_free_pages((gfp_mask) | GFP_DMA,(order))

extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
extern void FASTCALL(free_hot_page(struct page *page));
extern void FASTCALL(free_cold_page(struct page *page));

#define __free_page(page) __free_pages((page), 0)
#define free_page(addr) free_pages((addr),0)

void page_alloc_init(void);
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);

#endif /* __LINUX_GFP_H */