kernel/arch/metag/include/asm/cmpxchg.h

   1 #ifndef __ASM_METAG_CMPXCHG_H
   2 #define __ASM_METAG_CMPXCHG_H
   3
   4 #include <asm/barrier.h>
   5
   6 #if defined(CONFIG_METAG_ATOMICITY_IRQSOFF)
   7 #include <asm/cmpxchg_irq.h>
   8 #elif defined(CONFIG_METAG_ATOMICITY_LOCK1)
   9 #include <asm/cmpxchg_lock1.h>
  10 #elif defined(CONFIG_METAG_ATOMICITY_LNKGET)
  11 #include <asm/cmpxchg_lnkget.h>
  12 #endif
  13
  14 extern void __xchg_called_with_bad_pointer(void);
  15
  16 #define __xchg(ptr, x, size)                            \
  17 ({                                                      \
  18         unsigned long __xchg__res;                      \
  19         volatile void *__xchg_ptr = (ptr);              \
  20         switch (size) {                                 \
  21         case 4:                                         \
  22                 __xchg__res = xchg_u32(__xchg_ptr, x);  \
  23                 break;                                  \
  24         case 1:                                         \
  25                 __xchg__res = xchg_u8(__xchg_ptr, x);   \
  26                 break;                                  \
  27         default:                                        \
  28                 __xchg_called_with_bad_pointer();       \
  29                 __xchg__res = x;                        \
  30                 break;                                  \
  31         }                                               \
  32                                                         \
  33         __xchg__res;                                    \
  34 })
  35
  36 #define xchg(ptr, x)    \
  37         ((__typeof__(*(ptr)))__xchg((ptr), (unsigned long)(x), sizeof(*(ptr))))
  38
  39 /* This function doesn't exist, so you'll get a linker error
  40  * if something tries to do an invalid cmpxchg(). */
  41 extern void __cmpxchg_called_with_bad_pointer(void);
  42
  43 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
  44                                       unsigned long new, int size)
  45 {
  46         switch (size) {
  47         case 4:
  48                 return __cmpxchg_u32(ptr, old, new);
  49         }
  50         __cmpxchg_called_with_bad_pointer();
  51         return old;
  52 }
  53
  54 #define __HAVE_ARCH_CMPXCHG 1
  55
  56 #define cmpxchg(ptr, o, n)                                              \
  57         ({                                                              \
  58                 __typeof__(*(ptr)) _o_ = (o);                           \
  59                 __typeof__(*(ptr)) _n_ = (n);                           \
  60                 (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
  61                                                (unsigned long)_n_,      \
  62                                                sizeof(*(ptr)));         \
  63         })
  64
  65 #endif /* __ASM_METAG_CMPXCHG_H */