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