include/asm-s390/percpu.h

   1 #ifndef __ARCH_S390_PERCPU__
   2 #define __ARCH_S390_PERCPU__
   3
   4 #include <linux/compiler.h>
   5 #include <asm/lowcore.h>
   6
   7 #define __GENERIC_PER_CPU
   8
   9 /*
  10  * s390 uses its own implementation for per cpu data, the offset of
  11  * the cpu local data area is cached in the cpu's lowcore memory.
  12  * For 64 bit module code s390 forces the use of a GOT slot for the
  13  * address of the per cpu variable. This is needed because the module
  14  * may be more than 4G above the per cpu area.
  15  */
  16 #if defined(__s390x__) && defined(MODULE)
  17
  18 #define __reloc_hide(var,offset) \
  19   (*({ unsigned long *__ptr; \
  20        asm ( "larl %0,per_cpu__"#var"@GOTENT" \
  21              : "=a" (__ptr) : "X" (per_cpu__##var) ); \
  22        (typeof(&per_cpu__##var))((*__ptr) + (offset)); }))
  23
  24 #else
  25
  26 #define __reloc_hide(var, offset) \
  27   (*({ unsigned long __ptr; \
  28        asm ( "" : "=a" (__ptr) : "0" (&per_cpu__##var) ); \
  29        (typeof(&per_cpu__##var)) (__ptr + (offset)); }))
  30
  31 #endif
  32
  33 #ifdef CONFIG_SMP
  34
  35 extern unsigned long __per_cpu_offset[NR_CPUS];
  36
  37 /* Separate out the type, so (int[3], foo) works. */
  38 #define DEFINE_PER_CPU(type, name) \
  39     __attribute__((__section__(".data.percpu"))) \
  40     __typeof__(type) per_cpu__##name
  41
  42 #define __get_cpu_var(var) __reloc_hide(var,S390_lowcore.percpu_offset)
  43 #define per_cpu(var,cpu) __reloc_hide(var,__per_cpu_offset[cpu])
  44
  45 /* A macro to avoid #include hell... */
  46 #define percpu_modcopy(pcpudst, src, size)                      \
  47 do {                                                            \
  48         unsigned int __i;                                       \
  49         for (__i = 0; __i < NR_CPUS; __i++)                     \
  50                 if (cpu_possible(__i))                          \
  51                         memcpy((pcpudst)+__per_cpu_offset[__i], \
  52                                (src), (size));                  \
  53 } while (0)
  54
  55 #else /* ! SMP */
  56
  57 #define DEFINE_PER_CPU(type, name) \
  58     __typeof__(type) per_cpu__##name
  59
  60 #define __get_cpu_var(var) __reloc_hide(var,0)
  61 #define per_cpu(var,cpu) __reloc_hide(var,0)
  62
  63 #endif /* SMP */
  64
  65 #define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
  66
  67 #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
  68 #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
  69
  70 #endif /* __ARCH_S390_PERCPU__ */