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1/*
2 * include/asm-v850/atomic.h -- Atomic operations
3 *
4 * Copyright (C) 2001,02 NEC Corporation
5 * Copyright (C) 2001,02 Miles Bader <miles@gnu.org>
6 *
7 * This file is subject to the terms and conditions of the GNU General
8 * Public License. See the file COPYING in the main directory of this
9 * archive for more details.
10 *
11 * Written by Miles Bader <miles@gnu.org>
12 */
13
14#ifndef __V850_ATOMIC_H__
15#define __V850_ATOMIC_H__
16
17
18#include <asm/system.h>
19
20#ifdef CONFIG_SMP
21#error SMP not supported
22#endif
23
24typedef struct { int counter; } atomic_t;
25
26#define ATOMIC_INIT(i) { (i) }
27
28#ifdef __KERNEL__
29
30#define atomic_read(v) ((v)->counter)
31#define atomic_set(v,i) (((v)->counter) = (i))
32
33static inline int atomic_add_return (int i, volatile atomic_t *v)
34{
35 unsigned long flags;
36 int res;
37
38 local_irq_save (flags);
39 res = v->counter + i;
40 v->counter = res;
41 local_irq_restore (flags);
42
43 return res;
44}
45
46static __inline__ int atomic_sub_return (int i, volatile atomic_t *v)
47{
48 unsigned long flags;
49 int res;
50
51 local_irq_save (flags);
52 res = v->counter - i;
53 v->counter = res;
54 local_irq_restore (flags);
55
56 return res;
57}
58
59static __inline__ void atomic_clear_mask (unsigned long mask, unsigned long *addr)
60{
61 unsigned long flags;
62
63 local_irq_save (flags);
64 *addr &= ~mask;
65 local_irq_restore (flags);
66}
67
68#endif
69
70#define atomic_add(i, v) atomic_add_return ((i), (v))
71#define atomic_sub(i, v) atomic_sub_return ((i), (v))
72
73#define atomic_dec_return(v) atomic_sub_return (1, (v))
74#define atomic_inc_return(v) atomic_add_return (1, (v))
75#define atomic_inc(v) atomic_inc_return (v)
76#define atomic_dec(v) atomic_dec_return (v)
77
78/*
79 * atomic_inc_and_test - increment and test
80 * @v: pointer of type atomic_t
81 *
82 * Atomically increments @v by 1
83 * and returns true if the result is zero, or false for all
84 * other cases.
85 */
86#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
87
88#define atomic_sub_and_test(i,v) (atomic_sub_return ((i), (v)) == 0)
89#define atomic_dec_and_test(v) (atomic_sub_return (1, (v)) == 0)
90#define atomic_add_negative(i,v) (atomic_add_return ((i), (v)) < 0)
91
92static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
93{
94 int ret;
95 unsigned long flags;
96
97 local_irq_save(flags);
98 ret = v->counter;
99 if (likely(ret == old))
100 v->counter = new;
101 local_irq_restore(flags);
102
103 return ret;
104}
105
106#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
107
108static inline int atomic_add_unless(atomic_t *v, int a, int u)
109{
110 int ret;
111 unsigned long flags;
112
113 local_irq_save(flags);
114 ret = v->counter;
115 if (ret != u)
116 v->counter += a;
117 local_irq_restore(flags);
118
119 return ret != u;
120}
121
122#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
123
124/* Atomic operations are already serializing on ARM */
125#define smp_mb__before_atomic_dec() barrier()
126#define smp_mb__after_atomic_dec() barrier()
127#define smp_mb__before_atomic_inc() barrier()
128#define smp_mb__after_atomic_inc() barrier()
129
130#include <asm-generic/atomic.h>
131#endif /* __V850_ATOMIC_H__ */