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/system.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) (*(volatile int *)&(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