include/asm-ppc/atomic.h

   1 /*
   2  * PowerPC atomic operations
   3  */
   4
   5 #ifndef _ASM_PPC_ATOMIC_H_
   6 #define _ASM_PPC_ATOMIC_H_
   7
   8 #include <linux/config.h>
   9
  10 #ifdef CONFIG_SMP
  11 typedef struct { volatile int counter; } atomic_t;
  12 #else
  13 typedef struct { int counter; } atomic_t;
  14 #endif
  15
  16 #define ATOMIC_INIT(i)  { (i) }
  17
  18 #define atomic_read(v)          ((v)->counter)
  19 #define atomic_set(v,i)         (((v)->counter) = (i))
  20
  21 extern void atomic_clear_mask(unsigned long mask, unsigned long *addr);
  22 extern void atomic_set_mask(unsigned long mask, unsigned long *addr);
  23
  24 extern __inline__ int atomic_add_return(int a, atomic_t *v)
  25 {
  26         int t;
  27
  28         __asm__ __volatile__("\n\
  29 1:      lwarx   %0,0,%3\n\
  30         add     %0,%2,%0\n\
  31         stwcx.  %0,0,%3\n\
  32         bne-    1b"
  33         : "=&r" (t), "=m" (*v)
  34         : "r" (a), "r" (v), "m" (*v)
  35         : "cc");
  36
  37         return t;
  38 }
  39
  40 extern __inline__ int atomic_sub_return(int a, atomic_t *v)
  41 {
  42         int t;
  43
  44         __asm__ __volatile__("\n\
  45 1:      lwarx   %0,0,%3\n\
  46         subf    %0,%2,%0\n\
  47         stwcx.  %0,0,%3\n\
  48         bne-    1b"
  49         : "=&r" (t), "=m" (*v)
  50         : "r" (a), "r" (v), "m" (*v)
  51         : "cc");
  52
  53         return t;
  54 }
  55
  56 extern __inline__ int atomic_inc_return(atomic_t *v)
  57 {
  58         int t;
  59
  60         __asm__ __volatile__("\n\
  61 1:      lwarx   %0,0,%2\n\
  62         addic   %0,%0,1\n\
  63         stwcx.  %0,0,%2\n\
  64         bne-    1b"
  65         : "=&r" (t), "=m" (*v)
  66         : "r" (v), "m" (*v)
  67         : "cc");
  68
  69         return t;
  70 }
  71
  72 extern __inline__ int atomic_dec_return(atomic_t *v)
  73 {
  74         int t;
  75
  76         __asm__ __volatile__("\n\
  77 1:      lwarx   %0,0,%2\n\
  78         addic   %0,%0,-1\n\
  79         stwcx.  %0,0,%2\n\
  80         bne     1b"
  81         : "=&r" (t), "=m" (*v)
  82         : "r" (v), "m" (*v)
  83         : "cc");
  84
  85         return t;
  86 }
  87
  88 #define atomic_add(a, v)                ((void) atomic_add_return((a), (v)))
  89 #define atomic_sub(a, v)                ((void) atomic_sub_return((a), (v)))
  90 #define atomic_sub_and_test(a, v)       (atomic_sub_return((a), (v)) == 0)
  91 #define atomic_inc(v)                   ((void) atomic_inc_return((v)))
  92 #define atomic_dec(v)                   ((void) atomic_dec_return((v)))
  93 #define atomic_dec_and_test(v)          (atomic_dec_return((v)) == 0)
  94
  95 #endif /* _ASM_PPC_ATOMIC_H_ */