LXR linux/arch/cris/include/asm/atomic.h

   1/* $Id: atomic.h,v 1.3 2001/07/25 16:15:19 bjornw Exp $ */
   2
   3#ifndef __ASM_CRIS_ATOMIC__
   4#define __ASM_CRIS_ATOMIC__
   5
   6#include <linux/compiler.h>
   7#include <linux/types.h>
   8#include <asm/cmpxchg.h>
   9#include <arch/atomic.h>
  10
  11/*
  12 * Atomic operations that C can't guarantee us.  Useful for
  13 * resource counting etc..
  14 */
  15
  16#define ATOMIC_INIT(i)  { (i) }
  17
  18#define atomic_read(v) ACCESS_ONCE((v)->counter)
  19#define atomic_set(v,i) (((v)->counter) = (i))
  20
  21/* These should be written in asm but we do it in C for now. */
  22
  23static inline void atomic_add(int i, volatile atomic_t *v)
  24{
  25        unsigned long flags;
  26        cris_atomic_save(v, flags);
  27        v->counter += i;
  28        cris_atomic_restore(v, flags);
  29}
  30
  31static inline void atomic_sub(int i, volatile atomic_t *v)
  32{
  33        unsigned long flags;
  34        cris_atomic_save(v, flags);
  35        v->counter -= i;
  36        cris_atomic_restore(v, flags);
  37}
  38
  39static inline int atomic_add_return(int i, volatile atomic_t *v)
  40{
  41        unsigned long flags;
  42        int retval;
  43        cris_atomic_save(v, flags);
  44        retval = (v->counter += i);
  45        cris_atomic_restore(v, flags);
  46        return retval;
  47}
  48
  49#define atomic_add_negative(a, v)       (atomic_add_return((a), (v)) < 0)
  50
  51static inline int atomic_sub_return(int i, volatile atomic_t *v)
  52{
  53        unsigned long flags;
  54        int retval;
  55        cris_atomic_save(v, flags);
  56        retval = (v->counter -= i);
  57        cris_atomic_restore(v, flags);
  58        return retval;
  59}
  60
  61static inline int atomic_sub_and_test(int i, volatile atomic_t *v)
  62{
  63        int retval;
  64        unsigned long flags;
  65        cris_atomic_save(v, flags);
  66        retval = (v->counter -= i) == 0;
  67        cris_atomic_restore(v, flags);
  68        return retval;
  69}
  70
  71static inline void atomic_inc(volatile atomic_t *v)
  72{
  73        unsigned long flags;
  74        cris_atomic_save(v, flags);
  75        (v->counter)++;
  76        cris_atomic_restore(v, flags);
  77}
  78
  79static inline void atomic_dec(volatile atomic_t *v)
  80{
  81        unsigned long flags;
  82        cris_atomic_save(v, flags);
  83        (v->counter)--;
  84        cris_atomic_restore(v, flags);
  85}
  86
  87static inline int atomic_inc_return(volatile atomic_t *v)
  88{
  89        unsigned long flags;
  90        int retval;
  91        cris_atomic_save(v, flags);
  92        retval = ++(v->counter);
  93        cris_atomic_restore(v, flags);
  94        return retval;
  95}
  96
  97static inline int atomic_dec_return(volatile atomic_t *v)
  98{
  99        unsigned long flags;
 100        int retval;
 101        cris_atomic_save(v, flags);
 102        retval = --(v->counter);
 103        cris_atomic_restore(v, flags);
 104        return retval;
 105}
 106static inline int atomic_dec_and_test(volatile atomic_t *v)
 107{
 108        int retval;
 109        unsigned long flags;
 110        cris_atomic_save(v, flags);
 111        retval = --(v->counter) == 0;
 112        cris_atomic_restore(v, flags);
 113        return retval;
 114}
 115
 116static inline int atomic_inc_and_test(volatile atomic_t *v)
 117{
 118        int retval;
 119        unsigned long flags;
 120        cris_atomic_save(v, flags);
 121        retval = ++(v->counter) == 0;
 122        cris_atomic_restore(v, flags);
 123        return retval;
 124}
 125
 126static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 127{
 128        int ret;
 129        unsigned long flags;
 130
 131        cris_atomic_save(v, flags);
 132        ret = v->counter;
 133        if (likely(ret == old))
 134                v->counter = new;
 135        cris_atomic_restore(v, flags);
 136        return ret;
 137}
 138
 139#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 140
 141static inline int __atomic_add_unless(atomic_t *v, int a, int u)
 142{
 143        int ret;
 144        unsigned long flags;
 145
 146        cris_atomic_save(v, flags);
 147        ret = v->counter;
 148        if (ret != u)
 149                v->counter += a;
 150        cris_atomic_restore(v, flags);
 151        return ret;
 152}
 153
 154/* Atomic operations are already serializing */
 155#define smp_mb__before_atomic_dec()    barrier()
 156#define smp_mb__after_atomic_dec()     barrier()
 157#define smp_mb__before_atomic_inc()    barrier()
 158#define smp_mb__after_atomic_inc()     barrier()
 159
 160#endif
 161