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 /*
   8  * s390 uses its own implementation for per cpu data, the offset of
   9  * the cpu local data area is cached in the cpu's lowcore memory.
  10  * For 64 bit module code s390 forces the use of a GOT slot for the
  11  * address of the per cpu variable. This is needed because the module
  12  * may be more than 4G above the per cpu area.
  13  */
  14 #if defined(__s390x__) && defined(MODULE)
  15
  16 #define __reloc_hide(var,offset) (*({                   \
  17         extern int simple_identifier_##var(void);       \
  18         unsigned long *__ptr;                           \
  19         asm ( "larl %0,per_cpu__"#var"@GOTENT"          \
  20             : "=a" (__ptr) : "X" (per_cpu__##var) );    \
  21         (typeof(&per_cpu__##var))((*__ptr) + (offset)); }))
  22
  23 #else
  24
  25 #define __reloc_hide(var, offset) (*({                          \
  26         extern int simple_identifier_##var(void);               \
  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 #define __get_cpu_var(var) __reloc_hide(var,S390_lowcore.percpu_offset)
  38 #define __raw_get_cpu_var(var) __reloc_hide(var,S390_lowcore.percpu_offset)
  39 #define per_cpu(var,cpu) __reloc_hide(var,__per_cpu_offset[cpu])
  40 #define per_cpu_offset(x) (__per_cpu_offset[x])
  41
  42 /* A macro to avoid #include hell... */
  43 #define percpu_modcopy(pcpudst, src, size)                      \
  44 do {                                                            \
  45         unsigned int __i;                                       \
  46         for_each_possible_cpu(__i)                              \
  47                 memcpy((pcpudst)+__per_cpu_offset[__i],         \
  48                        (src), (size));                          \
  49 } while (0)
  50
  51 #else /* ! SMP */
  52
  53 #define __get_cpu_var(var) __reloc_hide(var,0)
  54 #define __raw_get_cpu_var(var) __reloc_hide(var,0)
  55 #define per_cpu(var,cpu) __reloc_hide(var,0)
  56
  57 #endif /* SMP */
  58
  59 #define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
  60
  61 #endif /* __ARCH_S390_PERCPU__ */