arch/sh/include/asm/cmpxchg.h

   1 #ifndef __ASM_SH_CMPXCHG_H
   2 #define __ASM_SH_CMPXCHG_H
   3
   4 /*
   5  * Atomic operations that C can't guarantee us.  Useful for
   6  * resource counting etc..
   7  */
   8
   9 #include <linux/compiler.h>
  10 #include <linux/types.h>
  11
  12 #if defined(CONFIG_GUSA_RB)
  13 #include <asm/cmpxchg-grb.h>
  14 #elif defined(CONFIG_CPU_SH4A)
  15 #include <asm/cmpxchg-llsc.h>
  16 #elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP)
  17 #include <asm/cmpxchg-cas.h>
  18 #else
  19 #include <asm/cmpxchg-irq.h>
  20 #endif
  21
  22 extern void __xchg_called_with_bad_pointer(void);
  23
  24 #define __xchg(ptr, x, size)                            \
  25 ({                                                      \
  26         unsigned long __xchg__res;                      \
  27         volatile void *__xchg_ptr = (ptr);              \
  28         switch (size) {                                 \
  29         case 4:                                         \
  30                 __xchg__res = xchg_u32(__xchg_ptr, x);  \
  31                 break;                                  \
  32         case 2:                                         \
  33                 __xchg__res = xchg_u16(__xchg_ptr, x);  \
  34                 break;                                  \
  35         case 1:                                         \
  36                 __xchg__res = xchg_u8(__xchg_ptr, x);   \
  37                 break;                                  \
  38         default:                                        \
  39                 __xchg_called_with_bad_pointer();       \
  40                 __xchg__res = x;                        \
  41                 break;                                  \
  42         }                                               \
  43                                                         \
  44         __xchg__res;                                    \
  45 })
  46
  47 #define xchg(ptr,x)     \
  48         ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
  49
  50 /* This function doesn't exist, so you'll get a linker error
  51  * if something tries to do an invalid cmpxchg(). */
  52 extern void __cmpxchg_called_with_bad_pointer(void);
  53
  54 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
  55                 unsigned long new, int size)
  56 {
  57         switch (size) {
  58         case 4:
  59                 return __cmpxchg_u32(ptr, old, new);
  60         }
  61         __cmpxchg_called_with_bad_pointer();
  62         return old;
  63 }
  64
  65 #define cmpxchg(ptr,o,n)                                                 \
  66   ({                                                                     \
  67      __typeof__(*(ptr)) _o_ = (o);                                       \
  68      __typeof__(*(ptr)) _n_ = (n);                                       \
  69      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
  70                                     (unsigned long)_n_, sizeof(*(ptr))); \
  71   })
  72
  73 #endif /* __ASM_SH_CMPXCHG_H */