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 #define __per_cpu_offset(cpu) (cpu_pda(cpu)->data_offset)
  15 #define __my_cpu_offset() read_pda(data_offset)
  16
  17 #define per_cpu_offset(x) (__per_cpu_offset(x))
  18
  19 /* Separate out the type, so (int[3], foo) works. */
  20 #define DEFINE_PER_CPU(type, name) \
  21     __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name
  22
  23 /* var is in discarded region: offset to particular copy we want */
  24 #define per_cpu(var, cpu) (*({                          \
  25         extern int simple_identifier_##var(void);       \
  26         RELOC_HIDE(&per_cpu__##var, __per_cpu_offset(cpu)); }))
  27 #define __get_cpu_var(var) (*({                         \
  28         extern int simple_identifier_##var(void);       \
  29         RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()); }))
  30 #define __raw_get_cpu_var(var) (*({                     \
  31         extern int simple_identifier_##var(void);       \
  32         RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()); }))
  33
  34 /* A macro to avoid #include hell... */
  35 #define percpu_modcopy(pcpudst, src, size)                      \
  36 do {                                                            \
  37         unsigned int __i;                                       \
  38         for_each_possible_cpu(__i)                              \
  39                 memcpy((pcpudst)+__per_cpu_offset(__i),         \
  40                        (src), (size));                          \
  41 } while (0)
  42
  43 extern void setup_per_cpu_areas(void);
  44
  45 #else /* ! SMP */
  46
  47 #define DEFINE_PER_CPU(type, name) \
  48     __typeof__(type) per_cpu__##name
  49
  50 #define per_cpu(var, cpu)                       (*((void)(cpu), &per_cpu__##var))
  51 #define __get_cpu_var(var)                      per_cpu__##var
  52 #define __raw_get_cpu_var(var)                  per_cpu__##var
  53
  54 #endif  /* SMP */
  55
  56 #define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
  57
  58 #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
  59 #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
  60
  61 #endif /* _ASM_X8664_PERCPU_H_ */