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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ASM_SH_ATOMIC_H
3#define __ASM_SH_ATOMIC_H
4
5#if defined(CONFIG_CPU_J2)
6
7#include <asm-generic/atomic.h>
8
9#else
10
11/*
12 * Atomic operations that C can't guarantee us. Useful for
13 * resource counting etc..
14 *
15 */
16
17#include <linux/compiler.h>
18#include <linux/types.h>
19#include <asm/cmpxchg.h>
20#include <asm/barrier.h>
21
22#define ATOMIC_INIT(i) { (i) }
23
24#define atomic_read(v) READ_ONCE((v)->counter)
25#define atomic_set(v,i) WRITE_ONCE((v)->counter, (i))
26
27#if defined(CONFIG_GUSA_RB)
28#include <asm/atomic-grb.h>
29#elif defined(CONFIG_CPU_SH4A)
30#include <asm/atomic-llsc.h>
31#else
32#include <asm/atomic-irq.h>
33#endif
34
35#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
36#define atomic_dec_return(v) atomic_sub_return(1, (v))
37#define atomic_inc_return(v) atomic_add_return(1, (v))
38#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
39#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
40#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
41
42#define atomic_inc(v) atomic_add(1, (v))
43#define atomic_dec(v) atomic_sub(1, (v))
44
45#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
46#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
47
48/**
49 * __atomic_add_unless - add unless the number is a given value
50 * @v: pointer of type atomic_t
51 * @a: the amount to add to v...
52 * @u: ...unless v is equal to u.
53 *
54 * Atomically adds @a to @v, so long as it was not @u.
55 * Returns the old value of @v.
56 */
57static inline int __atomic_add_unless(atomic_t *v, int a, int u)
58{
59 int c, old;
60 c = atomic_read(v);
61 for (;;) {
62 if (unlikely(c == (u)))
63 break;
64 old = atomic_cmpxchg((v), c, c + (a));
65 if (likely(old == c))
66 break;
67 c = old;
68 }
69
70 return c;
71}
72
73#endif /* CONFIG_CPU_J2 */
74
75#endif /* __ASM_SH_ATOMIC_H */