include/asm-generic/percpu.h

   1 #ifndef _ASM_GENERIC_PERCPU_H_
   2 #define _ASM_GENERIC_PERCPU_H_
   3 #include <linux/compiler.h>
   4 #include <linux/threads.h>
   5
   6 #define __GENERIC_PER_CPU
   7 #ifdef CONFIG_SMP
   8
   9 extern unsigned long __per_cpu_offset[NR_CPUS];
  10
  11 #define per_cpu_offset(x) (__per_cpu_offset[x])
  12
  13 /* Separate out the type, so (int[3], foo) works. */
  14 #define DEFINE_PER_CPU(type, name) \
  15     __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name
  16
  17 /* var is in discarded region: offset to particular copy we want */
  18 #define per_cpu(var, cpu) (*({                          \
  19         extern int simple_identifier_##var(void);       \
  20         RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]); }))
  21 #define __get_cpu_var(var) per_cpu(var, smp_processor_id())
  22 #define __raw_get_cpu_var(var) per_cpu(var, raw_smp_processor_id())
  23
  24 /* A macro to avoid #include hell... */
  25 #define percpu_modcopy(pcpudst, src, size)                      \
  26 do {                                                            \
  27         unsigned int __i;                                       \
  28         for_each_possible_cpu(__i)                              \
  29                 memcpy((pcpudst)+__per_cpu_offset[__i],         \
  30                        (src), (size));                          \
  31 } while (0)
  32 #else /* ! SMP */
  33
  34 #define DEFINE_PER_CPU(type, name) \
  35     __typeof__(type) per_cpu__##name
  36
  37 #define per_cpu(var, cpu)                       (*((void)(cpu), &per_cpu__##var))
  38 #define __get_cpu_var(var)                      per_cpu__##var
  39 #define __raw_get_cpu_var(var)                  per_cpu__##var
  40
  41 #endif  /* SMP */
  42
  43 #define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
  44
  45 #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
  46 #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
  47
  48 #endif /* _ASM_GENERIC_PERCPU_H_ */