aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-v850/atomic.h
blob: f5b9ab6f4e70da97b847db5e910c5956a63a9acd (plain) (blame)
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
/*
 * include/asm-v850/atomic.h -- Atomic operations
 *
 *  Copyright (C) 2001,02  NEC Corporation
 *  Copyright (C) 2001,02  Miles Bader <miles@gnu.org>
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file COPYING in the main directory of this
 * archive for more details.
 *
 * Written by Miles Bader <miles@gnu.org>
 */

#ifndef __V850_ATOMIC_H__
#define __V850_ATOMIC_H__

#include <linux/config.h>

#include <asm/system.h>

#ifdef CONFIG_SMP
#error SMP not supported
#endif

typedef struct { int counter; } atomic_t;

#define ATOMIC_INIT(i)	{ (i) }

#ifdef __KERNEL__

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

static inline int atomic_add_return (int i, volatile atomic_t *v)
{
	unsigned long flags;
	int res;

	local_irq_save (flags);
	res = v->counter + i;
	v->counter = res;
	local_irq_restore (flags);

	return res;
}

static __inline__ int atomic_sub_return (int i, volatile atomic_t *v)
{
	unsigned long flags;
	int res;

	local_irq_save (flags);
	res = v->counter - i;
	v->counter = res;
	local_irq_restore (flags);

	return res;
}

static __inline__ void atomic_clear_mask (unsigned long mask, unsigned long *addr)
{
	unsigned long flags;

	local_irq_save (flags);
	*addr &= ~mask;
	local_irq_restore (flags);
}

#endif

#define atomic_add(i, v)	atomic_add_return ((i), (v))
#define atomic_sub(i, v)	atomic_sub_return ((i), (v))

#define atomic_dec_return(v)	atomic_sub_return (1, (v))
#define atomic_inc_return(v)	atomic_add_return (1, (v))
#define atomic_inc(v) 		atomic_inc_return (v)
#define atomic_dec(v) 		atomic_dec_return (v)

/*
 * atomic_inc_and_test - increment and test
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1
 * and returns true if the result is zero, or false for all
 * other cases.
 */
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)

#define atomic_sub_and_test(i,v)	(atomic_sub_return ((i), (v)) == 0)
#define atomic_dec_and_test(v)		(atomic_sub_return (1, (v)) == 0)
#define atomic_add_negative(i,v)	(atomic_add_return ((i), (v)) < 0)

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

	local_irq_save(flags);
	ret = v->counter;
	if (likely(ret == old))
		v->counter = new;
	local_irq_restore(flags);

	return ret;
}

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

	local_irq_save(flags);
	ret = v->counter;
	if (ret != u)
		v->counter += a;
	local_irq_restore(flags);

	return ret != u;
}

#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)

/* Atomic operations are already serializing on ARM */
#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()

#include <asm-generic/atomic.h>
#endif /* __V850_ATOMIC_H__ */