summaryrefslogtreecommitdiffstats
path: root/include/asm-sh/atomic.h
blob: 618d8e0de3480e7b4c8f8610c3d8a35628846bbf (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
#ifndef __ASM_SH_ATOMIC_H
#define __ASM_SH_ATOMIC_H

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

typedef struct { volatile int counter; } atomic_t;

#define ATOMIC_INIT(i)	( (atomic_t) { (i) } )

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

#include <asm/system.h>

/*
 * To get proper branch prediction for the main line, we must branch
 * forward to code at the end of this object's .text section, then
 * branch back to restart the operation.
 */

static __inline__ void atomic_add(int i, atomic_t * v)
{
	unsigned long flags;

	local_irq_save(flags);
	*(long *)v += i;
	local_irq_restore(flags);
}

static __inline__ void atomic_sub(int i, atomic_t *v)
{
	unsigned long flags;

	local_irq_save(flags);
	*(long *)v -= i;
	local_irq_restore(flags);
}

static __inline__ int atomic_add_return(int i, atomic_t * v)
{
	unsigned long temp, flags;

	local_irq_save(flags);
	temp = *(long *)v;
	temp += i;
	*(long *)v = temp;
	local_irq_restore(flags);

	return temp;
}

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

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

	local_irq_save(flags);
	temp = *(long *)v;
	temp -= i;
	*(long *)v = temp;
	local_irq_restore(flags);

	return temp;
}

#define atomic_dec_return(v) atomic_sub_return(1,(v))
#define atomic_inc_return(v) atomic_add_return(1,(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_inc(v) atomic_add(1,(v))
#define atomic_dec(v) atomic_sub(1,(v))

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)

static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v)
{
	unsigned long flags;

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

static __inline__ void atomic_set_mask(unsigned int mask, atomic_t *v)
{
	unsigned long flags;

	local_irq_save(flags);
	*(long *)v |= mask;
	local_irq_restore(flags);
}

/* Atomic operations are already serializing on SH */
#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 /* __ASM_SH_ATOMIC_H */