atomic.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef __TOOLS_LINUX_ATOMIC_H
 3#define __TOOLS_LINUX_ATOMIC_H
 4
 5#include <asm/atomic.h>
 6
 7void atomic_long_set(atomic_long_t *v, long i);
 8
 9/* atomic_cmpxchg_relaxed */
10#ifndef atomic_cmpxchg_relaxed
11#define  atomic_cmpxchg_relaxed		atomic_cmpxchg
12#define  atomic_cmpxchg_release         atomic_cmpxchg
13#endif /* atomic_cmpxchg_relaxed */
14
15static inline bool atomic_try_cmpxchg(atomic_t *ptr, int *oldp, int new)
16{
17	int ret, old = *oldp;
18
19	ret = atomic_cmpxchg(ptr, old, new);
20	if (ret != old)
21		*oldp = ret;
22	return ret == old;
23}
24
25static inline bool atomic_inc_unless_negative(atomic_t *v)
26{
27	int c = atomic_read(v);
28
29	do {
30		if (unlikely(c < 0))
31			return false;
32	} while (!atomic_try_cmpxchg(v, &c, c + 1));
33
34	return true;
35}
36
37#endif /* __TOOLS_LINUX_ATOMIC_H */