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1#ifndef __ASM_SH_ATOMIC_H
2#define __ASM_SH_ATOMIC_H
3
4/*
5 * Atomic operations that C can't guarantee us. Useful for
6 * resource counting etc..
7 *
8 */
9
10#include <linux/compiler.h>
11#include <linux/types.h>
12#include <asm/system.h>
13
14#define ATOMIC_INIT(i) ( (atomic_t) { (i) } )
15
16#define atomic_read(v) (*(volatile int *)&(v)->counter)
17#define atomic_set(v,i) ((v)->counter = (i))
18
19#if defined(CONFIG_GUSA_RB)
20#include <asm/atomic-grb.h>
21#elif defined(CONFIG_CPU_SH4A)
22#include <asm/atomic-llsc.h>
23#else
24#include <asm/atomic-irq.h>
25#endif
26
27#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
28#define atomic_dec_return(v) atomic_sub_return(1, (v))
29#define atomic_inc_return(v) atomic_add_return(1, (v))
30#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
31#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
32#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
33
34#define atomic_inc(v) atomic_add(1, (v))
35#define atomic_dec(v) atomic_sub(1, (v))
36
37#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
38#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
39
40/**
41 * __atomic_add_unless - add unless the number is a given value
42 * @v: pointer of type atomic_t
43 * @a: the amount to add to v...
44 * @u: ...unless v is equal to u.
45 *
46 * Atomically adds @a to @v, so long as it was not @u.
47 * Returns the old value of @v.
48 */
49static inline int __atomic_add_unless(atomic_t *v, int a, int u)
50{
51 int c, old;
52 c = atomic_read(v);
53 for (;;) {
54 if (unlikely(c == (u)))
55 break;
56 old = atomic_cmpxchg((v), c, c + (a));
57 if (likely(old == c))
58 break;
59 c = old;
60 }
61
62 return c;
63}
64
65#define smp_mb__before_atomic_dec() smp_mb()
66#define smp_mb__after_atomic_dec() smp_mb()
67#define smp_mb__before_atomic_inc() smp_mb()
68#define smp_mb__after_atomic_inc() smp_mb()
69
70#endif /* __ASM_SH_ATOMIC_H */