ia64: Fix setup_per_cpu_areas() compilation error
[linux-2.6-block.git] / include / linux / percpu.h
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1#ifndef __LINUX_PERCPU_H
2#define __LINUX_PERCPU_H
7ff6f082 3
0a3021f4 4#include <linux/preempt.h>
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5#include <linux/slab.h> /* For kmalloc() */
6#include <linux/smp.h>
7ff6f082 7#include <linux/cpumask.h>
6a242909 8#include <linux/pfn.h>
7ff6f082 9
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10#include <asm/percpu.h>
11
6a242909 12/* enough to cover all DEFINE_PER_CPUs in modules */
b00742d3 13#ifdef CONFIG_MODULES
6a242909 14#define PERCPU_MODULE_RESERVE (8 << 10)
b00742d3 15#else
6a242909 16#define PERCPU_MODULE_RESERVE 0
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17#endif
18
6a242909 19#ifndef PERCPU_ENOUGH_ROOM
b00742d3 20#define PERCPU_ENOUGH_ROOM \
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21 (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
22 PERCPU_MODULE_RESERVE)
23#endif
b00742d3 24
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25/*
26 * Must be an lvalue. Since @var must be a simple identifier,
27 * we force a syntax error here if it isn't.
28 */
29#define get_cpu_var(var) (*({ \
a666ecfb 30 extern int simple_identifier_##var(void); \
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31 preempt_disable(); \
32 &__get_cpu_var(var); }))
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33#define put_cpu_var(var) preempt_enable()
34
35#ifdef CONFIG_SMP
36
e74e3962 37#ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
1da177e4 38
8d408b4b 39/* minimum unit size, also is the maximum supported allocation size */
6a242909 40#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10)
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41
42/*
43 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
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44 * back on the first chunk for dynamic percpu allocation if arch is
45 * manually allocating and mapping it for faster access (as a part of
46 * large page mapping for example).
8d408b4b 47 *
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48 * The following values give between one and two pages of free space
49 * after typical minimal boot (2-way SMP, single disk and NIC) with
50 * both defconfig and a distro config on x86_64 and 32. More
51 * intelligent way to determine this would be nice.
8d408b4b 52 */
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53#if BITS_PER_LONG > 32
54#define PERCPU_DYNAMIC_RESERVE (20 << 10)
55#else
56#define PERCPU_DYNAMIC_RESERVE (12 << 10)
57#endif
8d408b4b 58
fbf59bc9 59extern void *pcpu_base_addr;
2f39e637 60extern const int *pcpu_unit_map;
1da177e4 61
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62typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size);
63typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
64typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
a530b795 65typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
8c4bfc6e 66typedef void (*pcpu_fc_map_fn_t)(void *ptr, size_t size, void *addr);
fbf59bc9 67
ce3141a2 68extern size_t __init pcpu_setup_first_chunk(
edcb4639 69 size_t static_size, size_t reserved_size,
38a6be52 70 ssize_t dyn_size, size_t unit_size,
2f39e637 71 void *base_addr, const int *unit_map);
8d408b4b 72
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73extern ssize_t __init pcpu_embed_first_chunk(
74 size_t static_size, size_t reserved_size,
788e5abc 75 ssize_t dyn_size);
66c3a757 76
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77extern ssize_t __init pcpu_4k_first_chunk(
78 size_t static_size, size_t reserved_size,
79 pcpu_fc_alloc_fn_t alloc_fn,
80 pcpu_fc_free_fn_t free_fn,
81 pcpu_fc_populate_pte_fn_t populate_pte_fn);
82
8c4bfc6e 83#ifdef CONFIG_NEED_MULTIPLE_NODES
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84extern int __init pcpu_lpage_build_unit_map(
85 size_t static_size, size_t reserved_size,
86 ssize_t *dyn_sizep, size_t *unit_sizep,
87 size_t lpage_size, int *unit_map,
88 pcpu_fc_cpu_distance_fn_t cpu_distance_fn);
89
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90extern ssize_t __init pcpu_lpage_first_chunk(
91 size_t static_size, size_t reserved_size,
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92 size_t dyn_size, size_t unit_size,
93 size_t lpage_size, const int *unit_map,
94 int nr_units,
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95 pcpu_fc_alloc_fn_t alloc_fn,
96 pcpu_fc_free_fn_t free_fn,
97 pcpu_fc_map_fn_t map_fn);
98
99extern void *pcpu_lpage_remapped(void *kaddr);
100#else
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101static inline int pcpu_lpage_build_unit_map(
102 size_t static_size, size_t reserved_size,
103 ssize_t *dyn_sizep, size_t *unit_sizep,
104 size_t lpage_size, int *unit_map,
105 pcpu_fc_cpu_distance_fn_t cpu_distance_fn)
106{
107 return -EINVAL;
108}
109
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110static inline ssize_t __init pcpu_lpage_first_chunk(
111 size_t static_size, size_t reserved_size,
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112 size_t dyn_size, size_t unit_size,
113 size_t lpage_size, const int *unit_map,
114 int nr_units,
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115 pcpu_fc_alloc_fn_t alloc_fn,
116 pcpu_fc_free_fn_t free_fn,
117 pcpu_fc_map_fn_t map_fn)
118{
119 return -EINVAL;
120}
121
122static inline void *pcpu_lpage_remapped(void *kaddr)
123{
124 return NULL;
125}
126#endif
127
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128/*
129 * Use this to get to a cpu's version of the per-cpu object
130 * dynamically allocated. Non-atomic access to the current CPU's
131 * version should probably be combined with get_cpu()/put_cpu().
132 */
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133#define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
134
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135extern void *__alloc_reserved_percpu(size_t size, size_t align);
136
e74e3962 137#else /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
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138
139struct percpu_data {
140 void *ptrs[1];
141};
142
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143/* pointer disguising messes up the kmemleak objects tracking */
144#ifndef CONFIG_DEBUG_KMEMLEAK
fbf59bc9 145#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
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146#else
147#define __percpu_disguise(pdata) (struct percpu_data *)(pdata)
148#endif
fbf59bc9 149
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150#define per_cpu_ptr(ptr, cpu) \
151({ \
152 struct percpu_data *__p = __percpu_disguise(ptr); \
153 (__typeof__(ptr))__p->ptrs[(cpu)]; \
154})
155
e74e3962 156#endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
fbf59bc9 157
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158extern void *__alloc_percpu(size_t size, size_t align);
159extern void free_percpu(void *__pdata);
1da177e4 160
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161#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
162extern void __init setup_per_cpu_areas(void);
163#endif
164
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165#else /* CONFIG_SMP */
166
b36128c8 167#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
7ff6f082 168
f2a8205c 169static inline void *__alloc_percpu(size_t size, size_t align)
7ff6f082 170{
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171 /*
172 * Can't easily make larger alignment work with kmalloc. WARN
173 * on it. Larger alignment should only be used for module
174 * percpu sections on SMP for which this path isn't used.
175 */
e3176036 176 WARN_ON_ONCE(align > SMP_CACHE_BYTES);
d2b02615 177 return kzalloc(size, GFP_KERNEL);
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178}
179
f2a8205c 180static inline void free_percpu(void *p)
7ff6f082 181{
f2a8205c 182 kfree(p);
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183}
184
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185static inline void __init setup_per_cpu_areas(void) { }
186
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187#endif /* CONFIG_SMP */
188
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189#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
190 __alignof__(type))
1da177e4 191
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192/*
193 * Optional methods for optimized non-lvalue per-cpu variable access.
194 *
195 * @var can be a percpu variable or a field of it and its size should
196 * equal char, int or long. percpu_read() evaluates to a lvalue and
197 * all others to void.
198 *
199 * These operations are guaranteed to be atomic w.r.t. preemption.
200 * The generic versions use plain get/put_cpu_var(). Archs are
201 * encouraged to implement single-instruction alternatives which don't
202 * require preemption protection.
203 */
204#ifndef percpu_read
205# define percpu_read(var) \
206 ({ \
207 typeof(per_cpu_var(var)) __tmp_var__; \
208 __tmp_var__ = get_cpu_var(var); \
209 put_cpu_var(var); \
210 __tmp_var__; \
211 })
212#endif
213
214#define __percpu_generic_to_op(var, val, op) \
215do { \
216 get_cpu_var(var) op val; \
217 put_cpu_var(var); \
218} while (0)
219
220#ifndef percpu_write
221# define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
222#endif
223
224#ifndef percpu_add
225# define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
226#endif
227
228#ifndef percpu_sub
229# define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
230#endif
231
232#ifndef percpu_and
233# define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
234#endif
235
236#ifndef percpu_or
237# define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
238#endif
239
240#ifndef percpu_xor
241# define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
242#endif
243
1da177e4 244#endif /* __LINUX_PERCPU_H */