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[~andy/linux] / include / asm-x86_64 / percpu.h
1 #ifndef _ASM_X8664_PERCPU_H_
2 #define _ASM_X8664_PERCPU_H_
3 #include <linux/compiler.h>
4
5 /* Same as asm-generic/percpu.h, except that we store the per cpu offset
6    in the PDA. Longer term the PDA and every per cpu variable
7    should be just put into a single section and referenced directly
8    from %gs */
9
10 #ifdef CONFIG_SMP
11
12 #include <asm/pda.h>
13
14 #ifdef CONFIG_MODULES
15 # define PERCPU_MODULE_RESERVE 8192
16 #else
17 # define PERCPU_MODULE_RESERVE 0
18 #endif
19
20 #define PERCPU_ENOUGH_ROOM \
21         (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
22          PERCPU_MODULE_RESERVE)
23
24 #define __per_cpu_offset(cpu) (cpu_pda(cpu)->data_offset)
25 #define __my_cpu_offset() read_pda(data_offset)
26
27 #define per_cpu_offset(x) (__per_cpu_offset(x))
28
29 /* Separate out the type, so (int[3], foo) works. */
30 #define DEFINE_PER_CPU(type, name) \
31     __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name
32
33 /* var is in discarded region: offset to particular copy we want */
34 #define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset(cpu)))
35 #define __get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()))
36 #define __raw_get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()))
37
38 /* A macro to avoid #include hell... */
39 #define percpu_modcopy(pcpudst, src, size)                      \
40 do {                                                            \
41         unsigned int __i;                                       \
42         for_each_possible_cpu(__i)                              \
43                 memcpy((pcpudst)+__per_cpu_offset(__i),         \
44                        (src), (size));                          \
45 } while (0)
46
47 extern void setup_per_cpu_areas(void);
48
49 #else /* ! SMP */
50
51 #define DEFINE_PER_CPU(type, name) \
52     __typeof__(type) per_cpu__##name
53
54 #define per_cpu(var, cpu)                       (*((void)(cpu), &per_cpu__##var))
55 #define __get_cpu_var(var)                      per_cpu__##var
56 #define __raw_get_cpu_var(var)                  per_cpu__##var
57
58 #endif  /* SMP */
59
60 #define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
61
62 #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
63 #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
64
65 #endif /* _ASM_X8664_PERCPU_H_ */