arch/sh/include/asm/atomic.h

   1 #ifndef __ASM_SH_ATOMIC_H
   2 #define __ASM_SH_ATOMIC_H
   3
   4 #if defined(CONFIG_CPU_J2)
   5
   6 #include <asm-generic/atomic.h>
   7
   8 #else
   9
  10 /*
  11  * Atomic operations that C can't guarantee us.  Useful for
  12  * resource counting etc..
  13  *
  14  */
  15
  16 #include <linux/compiler.h>
  17 #include <linux/types.h>
  18 #include <asm/cmpxchg.h>
  19 #include <asm/barrier.h>
  20
  21 #define ATOMIC_INIT(i)  { (i) }
  22
  23 #define atomic_read(v)          READ_ONCE((v)->counter)
  24 #define atomic_set(v,i)         WRITE_ONCE((v)->counter, (i))
  25
  26 #if defined(CONFIG_GUSA_RB)
  27 #include <asm/atomic-grb.h>
  28 #elif defined(CONFIG_CPU_SH4A)
  29 #include <asm/atomic-llsc.h>
  30 #else
  31 #include <asm/atomic-irq.h>
  32 #endif
  33
  34 #define atomic_add_negative(a, v)       (atomic_add_return((a), (v)) < 0)
  35 #define atomic_dec_return(v)            atomic_sub_return(1, (v))
  36 #define atomic_inc_return(v)            atomic_add_return(1, (v))
  37 #define atomic_inc_and_test(v)          (atomic_inc_return(v) == 0)
  38 #define atomic_sub_and_test(i,v)        (atomic_sub_return((i), (v)) == 0)
  39 #define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
  40
  41 #define atomic_inc(v)                   atomic_add(1, (v))
  42 #define atomic_dec(v)                   atomic_sub(1, (v))
  43
  44 #define atomic_xchg(v, new)             (xchg(&((v)->counter), new))
  45 #define atomic_cmpxchg(v, o, n)         (cmpxchg(&((v)->counter), (o), (n)))
  46
  47 /**
  48  * __atomic_add_unless - add unless the number is a given value
  49  * @v: pointer of type atomic_t
  50  * @a: the amount to add to v...
  51  * @u: ...unless v is equal to u.
  52  *
  53  * Atomically adds @a to @v, so long as it was not @u.
  54  * Returns the old value of @v.
  55  */
  56 static inline int __atomic_add_unless(atomic_t *v, int a, int u)
  57 {
  58         int c, old;
  59         c = atomic_read(v);
  60         for (;;) {
  61                 if (unlikely(c == (u)))
  62                         break;
  63                 old = atomic_cmpxchg((v), c, c + (a));
  64                 if (likely(old == c))
  65                         break;
  66                 c = old;
  67         }
  68
  69         return c;
  70 }
  71
  72 #endif /* CONFIG_CPU_J2 */
  73
  74 #endif /* __ASM_SH_ATOMIC_H */