arch/sh/include/asm/atomic.h

   1 #ifndef __ASM_SH_ATOMIC_H
   2 #define __ASM_SH_ATOMIC_H
   3
   4 /*
   5  * Atomic operations that C can't guarantee us.  Useful for
   6  * resource counting etc..
   7  *
   8  */
   9
  10 #include <linux/compiler.h>
  11 #include <linux/types.h>
  12 #include <asm/system.h>
  13
  14 #define ATOMIC_INIT(i)  ( (atomic_t) { (i) } )
  15
  16 #define atomic_read(v)          (*(volatile int *)&(v)->counter)
  17 #define atomic_set(v,i)         ((v)->counter = (i))
  18
  19 #if defined(CONFIG_GUSA_RB)
  20 #include <asm/atomic-grb.h>
  21 #elif defined(CONFIG_CPU_SH4A)
  22 #include <asm/atomic-llsc.h>
  23 #else
  24 #include <asm/atomic-irq.h>
  25 #endif
  26
  27 #define atomic_add_negative(a, v)       (atomic_add_return((a), (v)) < 0)
  28 #define atomic_dec_return(v)            atomic_sub_return(1, (v))
  29 #define atomic_inc_return(v)            atomic_add_return(1, (v))
  30 #define atomic_inc_and_test(v)          (atomic_inc_return(v) == 0)
  31 #define atomic_sub_and_test(i,v)        (atomic_sub_return((i), (v)) == 0)
  32 #define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
  33 #define atomic_inc_not_zero(v)          atomic_add_unless((v), 1, 0)
  34
  35 #define atomic_inc(v)                   atomic_add(1, (v))
  36 #define atomic_dec(v)                   atomic_sub(1, (v))
  37
  38 #define atomic_xchg(v, new)             (xchg(&((v)->counter), new))
  39 #define atomic_cmpxchg(v, o, n)         (cmpxchg(&((v)->counter), (o), (n)))
  40
  41 /**
  42  * atomic_add_unless - add unless the number is a given value
  43  * @v: pointer of type atomic_t
  44  * @a: the amount to add to v...
  45  * @u: ...unless v is equal to u.
  46  *
  47  * Atomically adds @a to @v, so long as it was not @u.
  48  * Returns non-zero if @v was not @u, and zero otherwise.
  49  */
  50 static inline int atomic_add_unless(atomic_t *v, int a, int u)
  51 {
  52         int c, old;
  53         c = atomic_read(v);
  54         for (;;) {
  55                 if (unlikely(c == (u)))
  56                         break;
  57                 old = atomic_cmpxchg((v), c, c + (a));
  58                 if (likely(old == c))
  59                         break;
  60                 c = old;
  61         }
  62
  63         return c != (u);
  64 }
  65
  66 #define smp_mb__before_atomic_dec()     smp_mb()
  67 #define smp_mb__after_atomic_dec()      smp_mb()
  68 #define smp_mb__before_atomic_inc()     smp_mb()
  69 #define smp_mb__after_atomic_inc()      smp_mb()
  70
  71 #include <asm-generic/atomic-long.h>
  72 #include <asm-generic/atomic64.h>
  73
  74 #endif /* __ASM_SH_ATOMIC_H */