summaryrefslogtreecommitdiffstats
path: root/include/asm-cris/atomic.h
blob: b3dfea5a71e42ed83e44c3f40a086a71feb4ead8 (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
150
/* $Id: atomic.h,v 1.3 2001/07/25 16:15:19 bjornw Exp $ */

#ifndef __ASM_CRIS_ATOMIC__
#define __ASM_CRIS_ATOMIC__

#include <asm/system.h>

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

/*
 * Make sure gcc doesn't try to be clever and move things around
 * on us. We need to use _exactly_ the address the user gave us,
 * not some alias that contains the same information.
 */

#define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)

typedef struct { int counter; } atomic_t;

#define ATOMIC_INIT(i)  { (i) }

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

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

extern __inline__ void atomic_add(int i, volatile atomic_t *v)
{
	unsigned long flags;
	local_save_flags(flags);
	local_irq_disable();
	v->counter += i;
	local_irq_restore(flags);
}

extern __inline__ void atomic_sub(int i, volatile atomic_t *v)
{
	unsigned long flags;
	local_save_flags(flags);
	local_irq_disable();
	v->counter -= i;
	local_irq_restore(flags);
}

extern __inline__ int atomic_add_return(int i, volatile atomic_t *v)
{
	unsigned long flags;
	int retval;
	local_save_flags(flags);
	local_irq_disable();
	retval = (v->counter += i);
	local_irq_restore(flags);
	return retval;
}

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

extern __inline__ int atomic_sub_return(int i, volatile atomic_t *v)
{
	unsigned long flags;
	int retval;
	local_save_flags(flags);
	local_irq_disable();
	retval = (v->counter -= i);
	local_irq_restore(flags);
	return retval;
}

extern __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v)
{
	int retval;
	unsigned long flags;
	local_save_flags(flags);
	local_irq_disable();
	retval = (v->counter -= i) == 0;
	local_irq_restore(flags);
	return retval;
}

extern __inline__ void atomic_inc(volatile atomic_t *v)
{
	unsigned long flags;
	local_save_flags(flags);
	local_irq_disable();
	(v->counter)++;
	local_irq_restore(flags);
}

extern __inline__ void atomic_dec(volatile atomic_t *v)
{
	unsigned long flags;
	local_save_flags(flags);
	local_irq_disable();
	(v->counter)--;
	local_irq_restore(flags);
}

extern __inline__ int atomic_inc_return(volatile atomic_t *v)
{
	unsigned long flags;
	int retval;
	local_save_flags(flags);
	local_irq_disable();
	retval = (v->counter)++;
	local_irq_restore(flags);
	return retval;
}

extern __inline__ int atomic_dec_return(volatile atomic_t *v)
{
	unsigned long flags;
	int retval;
	local_save_flags(flags);
	local_irq_disable();
	retval = (v->counter)--;
	local_irq_restore(flags);
	return retval;
}
extern __inline__ int atomic_dec_and_test(volatile atomic_t *v)
{
	int retval;
	unsigned long flags;
	local_save_flags(flags);
	local_irq_disable();
	retval = --(v->counter) == 0;
	local_irq_restore(flags);
	return retval;
}

extern __inline__ int atomic_inc_and_test(volatile atomic_t *v)
{
	int retval;
	unsigned long flags;
	local_save_flags(flags);
	local_irq_disable();
	retval = ++(v->counter) == 0;
	local_irq_restore(flags);
	return retval;
}

/* Atomic operations are already serializing */
#define smp_mb__before_atomic_dec()    barrier()
#define smp_mb__after_atomic_dec()     barrier()
#define smp_mb__before_atomic_inc()    barrier()
#define smp_mb__after_atomic_inc()     barrier()

#endif
OpenPOWER on IntegriCloud