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/cmpxchg.h>
13#include <asm/barrier.h>
14
15#define ATOMIC_INIT(i)	{ (i) }
16
17#define atomic_read(v)		READ_ONCE((v)->counter)
18#define atomic_set(v,i)		WRITE_ONCE((v)->counter, (i))
19
20#if defined(CONFIG_GUSA_RB)
21#include <asm/atomic-grb.h>
22#elif defined(CONFIG_CPU_SH4A)
23#include <asm/atomic-llsc.h>
24#else
25#include <asm/atomic-irq.h>
26#endif
27
28#define atomic_add_negative(a, v)	(atomic_add_return((a), (v)) < 0)
29#define atomic_dec_return(v)		atomic_sub_return(1, (v))
30#define atomic_inc_return(v)		atomic_add_return(1, (v))
31#define atomic_inc_and_test(v)		(atomic_inc_return(v) == 0)
32#define atomic_sub_and_test(i,v)	(atomic_sub_return((i), (v)) == 0)
33#define atomic_dec_and_test(v)		(atomic_sub_return(1, (v)) == 0)
34
35#define atomic_inc(v)			atomic_add(1, (v))
36#define atomic_dec(v)			atomic_sub(1, (v))
37
38#define atomic_xchg(v, new)		(xchg(&((v)->counter), new))
39#define atomic_cmpxchg(v, o, n)		(cmpxchg(&((v)->counter), (o), (n)))
40
41/**
42 * __atomic_add_unless - add unless the number is a given value
43 * @v: pointer of type atomic_t
44 * @a: the amount to add to v...
45 * @u: ...unless v is equal to u.
46 *
47 * Atomically adds @a to @v, so long as it was not @u.
48 * Returns the old value of @v.
49 */
50static inline int __atomic_add_unless(atomic_t *v, int a, int u)
51{
52	int c, old;
53	c = atomic_read(v);
54	for (;;) {
55		if (unlikely(c == (u)))
56			break;
57		old = atomic_cmpxchg((v), c, c + (a));
58		if (likely(old == c))
59			break;
60		c = old;
61	}
62
63	return c;
64}
65
66#endif /* __ASM_SH_ATOMIC_H */
67