summaryrefslogtreecommitdiff
path: root/arch/cris/include/asm/atomic.h
blob: 279766a70664f6fdc0544397afe302d3f8052761 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/* $Id: atomic.h,v 1.3 2001/07/25 16:15:19 bjornw Exp $ */

#ifndef __ASM_CRIS_ATOMIC__
#define __ASM_CRIS_ATOMIC__

#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/cmpxchg.h>
#include <arch/atomic.h>
#include <arch/system.h>
#include <asm/barrier.h>

/*
 * Atomic operations that C can't guarantee us.  Useful for
 * resource counting etc..
 */

#define ATOMIC_INIT(i)  { (i) }

#define atomic_read(v) ACCESS_ONCE((v)->counter)
#define atomic_set(v,i) (((v)->counter) = (i))

/* These should be written in asm but we do it in C for now. */

#define ATOMIC_OP(op, c_op)						\
static inline void atomic_##op(int i, volatile atomic_t *v)		\
{									\
	unsigned long flags;						\
	cris_atomic_save(v, flags);					\
	v->counter c_op i;						\
	cris_atomic_restore(v, flags);					\
}									\

#define ATOMIC_OP_RETURN(op, c_op)					\
static inline int atomic_##op##_return(int i, volatile atomic_t *v)	\
{									\
	unsigned long flags;						\
	int retval;							\
	cris_atomic_save(v, flags);					\
	retval = (v->counter c_op i);					\
	cris_atomic_restore(v, flags);					\
	return retval;							\
}

#define ATOMIC_OPS(op, c_op) ATOMIC_OP(op, c_op) ATOMIC_OP_RETURN(op, c_op)

ATOMIC_OPS(add, +=)
ATOMIC_OPS(sub, -=)

#undef ATOMIC_OPS
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP

#define atomic_add_negative(a, v)	(atomic_add_return((a), (v)) < 0)

static inline int atomic_sub_and_test(int i, volatile atomic_t *v)
{
	int retval;
	unsigned long flags;
	cris_atomic_save(v, flags);
	retval = (v->counter -= i) == 0;
	cris_atomic_restore(v, flags);
	return retval;
}

static inline void atomic_inc(volatile atomic_t *v)
{
	unsigned long flags;
	cris_atomic_save(v, flags);
	(v->counter)++;
	cris_atomic_restore(v, flags);
}

static inline void atomic_dec(volatile atomic_t *v)
{
	unsigned long flags;
	cris_atomic_save(v, flags);
	(v->counter)--;
	cris_atomic_restore(v, flags);
}

static inline int atomic_inc_return(volatile atomic_t *v)
{
	unsigned long flags;
	int retval;
	cris_atomic_save(v, flags);
	retval = ++(v->counter);
	cris_atomic_restore(v, flags);
	return retval;
}

static inline int atomic_dec_return(volatile atomic_t *v)
{
	unsigned long flags;
	int retval;
	cris_atomic_save(v, flags);
	retval = --(v->counter);
	cris_atomic_restore(v, flags);
	return retval;
}
static inline int atomic_dec_and_test(volatile atomic_t *v)
{
	int retval;
	unsigned long flags;
	cris_atomic_save(v, flags);
	retval = --(v->counter) == 0;
	cris_atomic_restore(v, flags);
	return retval;
}

static inline int atomic_inc_and_test(volatile atomic_t *v)
{
	int retval;
	unsigned long flags;
	cris_atomic_save(v, flags);
	retval = ++(v->counter) == 0;
	cris_atomic_restore(v, flags);
	return retval;
}

static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
{
	int ret;
	unsigned long flags;

	cris_atomic_save(v, flags);
	ret = v->counter;
	if (likely(ret == old))
		v->counter = new;
	cris_atomic_restore(v, flags);
	return ret;
}

#define atomic_xchg(v, new) (xchg(&((v)->counter), new))

static inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
	int ret;
	unsigned long flags;

	cris_atomic_save(v, flags);
	ret = v->counter;
	if (ret != u)
		v->counter += a;
	cris_atomic_restore(v, flags);
	return ret;
}

#endif