LXR linux/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)          ((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
  29#define atomic_dec_return(v) atomic_sub_return(1,(v))
  30#define atomic_inc_return(v) atomic_add_return(1,(v))
  31
  32/*
  33 * atomic_inc_and_test - increment and test
  34 * @v: pointer of type atomic_t
  35 *
  36 * Atomically increments @v by 1
  37 * and returns true if the result is zero, or false for all
  38 * other cases.
  39 */
  40#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
  41
  42#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
  43#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
  44
  45#define atomic_inc(v) atomic_add(1,(v))
  46#define atomic_dec(v) atomic_sub(1,(v))
  47
  48#if !defined(CONFIG_GUSA_RB) && !defined(CONFIG_CPU_SH4A)
  49static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
  50{
  51        int ret;
  52        unsigned long flags;
  53
  54        local_irq_save(flags);
  55        ret = v->counter;
  56        if (likely(ret == old))
  57                v->counter = new;
  58        local_irq_restore(flags);
  59
  60        return ret;
  61}
  62
  63static inline int atomic_add_unless(atomic_t *v, int a, int u)
  64{
  65        int ret;
  66        unsigned long flags;
  67
  68        local_irq_save(flags);
  69        ret = v->counter;
  70        if (ret != u)
  71                v->counter += a;
  72        local_irq_restore(flags);
  73
  74        return ret != u;
  75}
  76#endif /* !CONFIG_GUSA_RB && !CONFIG_CPU_SH4A */
  77
  78#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
  79#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
  80
  81/* Atomic operations are already serializing on SH */
  82#define smp_mb__before_atomic_dec()     barrier()
  83#define smp_mb__after_atomic_dec()      barrier()
  84#define smp_mb__before_atomic_inc()     barrier()
  85#define smp_mb__after_atomic_inc()      barrier()
  86
  87#include <asm-generic/atomic-long.h>
  88#include <asm-generic/atomic64.h>
  89
  90#endif /* __ASM_SH_ATOMIC_H */
  91