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 #ifdef CONFIG_SMP
   7
   8 extern unsigned long __per_cpu_offset[NR_CPUS];
   9
  10 #define per_cpu_offset(x) (__per_cpu_offset[x])
  11
  12 /* Separate out the type, so (int[3], foo) works. */
  13 #define DEFINE_PER_CPU(type, name) \
  14     __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name
  15
  16 #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)               \
  17     __attribute__((__section__(".data.percpu.shared_aligned"))) \
  18     __typeof__(type) per_cpu__##name                            \
  19     ____cacheline_aligned_in_smp
  20
  21 /* var is in discarded region: offset to particular copy we want */
  22 #define per_cpu(var, cpu) (*({                          \
  23         extern int simple_identifier_##var(void);       \
  24         RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]); }))
  25 #define __get_cpu_var(var) per_cpu(var, smp_processor_id())
  26 #define __raw_get_cpu_var(var) per_cpu(var, raw_smp_processor_id())
  27
  28 /* A macro to avoid #include hell... */
  29 #define percpu_modcopy(pcpudst, src, size)                      \
  30 do {                                                            \
  31         unsigned int __i;                                       \
  32         for_each_possible_cpu(__i)                              \
  33                 memcpy((pcpudst)+__per_cpu_offset[__i],         \
  34                        (src), (size));                          \
  35 } while (0)
  36 #else /* ! SMP */
  37
  38 #define DEFINE_PER_CPU(type, name) \
  39     __typeof__(type) per_cpu__##name
  40
  41 #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)       \
  42     DEFINE_PER_CPU(type, name)
  43
  44 #define per_cpu(var, cpu)                       (*((void)(cpu), &per_cpu__##var))
  45 #define __get_cpu_var(var)                      per_cpu__##var
  46 #define __raw_get_cpu_var(var)                  per_cpu__##var
  47
  48 #endif  /* SMP */
  49
  50 #define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
  51
  52 #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
  53 #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
  54
  55 #endif /* _ASM_GENERIC_PERCPU_H_ */