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