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 #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)               \
  24     __attribute__((__section__(".data.percpu.shared_aligned"))) \
  25     __typeof__(type) per_cpu__##name                            \
  26     ____cacheline_internodealigned_in_smp
  27
  28 /* var is in discarded region: offset to particular copy we want */
  29 #define per_cpu(var, cpu) (*({                          \
  30         extern int simple_identifier_##var(void);       \
  31         RELOC_HIDE(&per_cpu__##var, __per_cpu_offset(cpu)); }))
  32 #define __get_cpu_var(var) (*({                         \
  33         extern int simple_identifier_##var(void);       \
  34         RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()); }))
  35 #define __raw_get_cpu_var(var) (*({                     \
  36         extern int simple_identifier_##var(void);       \
  37         RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()); }))
  38
  39 /* A macro to avoid #include hell... */
  40 #define percpu_modcopy(pcpudst, src, size)                      \
  41 do {                                                            \
  42         unsigned int __i;                                       \
  43         for_each_possible_cpu(__i)                              \
  44                 memcpy((pcpudst)+__per_cpu_offset(__i),         \
  45                        (src), (size));                          \
  46 } while (0)
  47
  48 extern void setup_per_cpu_areas(void);
  49
  50 #else /* ! SMP */
  51
  52 #define DEFINE_PER_CPU(type, name) \
  53     __typeof__(type) per_cpu__##name
  54 #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)       \
  55     DEFINE_PER_CPU(type, name)
  56
  57 #define per_cpu(var, cpu)                       (*((void)(cpu), &per_cpu__##var))
  58 #define __get_cpu_var(var)                      per_cpu__##var
  59 #define __raw_get_cpu_var(var)                  per_cpu__##var
  60
  61 #endif  /* SMP */
  62
  63 #define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
  64
  65 #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
  66 #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
  67
  68 #endif /* _ASM_X8664_PERCPU_H_ */