summaryrefslogtreecommitdiff
path: root/sys/arch/m68k/include/lock.h
blob: 475236a26d42902ec7ee47297a921956205d736a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
/*	$OpenBSD: lock.h,v 1.1 2007/05/01 18:56:30 miod Exp $	*/

/* public domain */

#ifndef	_M68K_LOCK_H_
#define	_M68K_LOCK_H_

typedef volatile u_int __cpu_simple_lock_t;

#define	__SIMPLELOCK_LOCKED	1
#define	__SIMPLELOCK_UNLOCKED	0

static __inline__ void
__cpu_simple_lock_init(__cpu_simple_lock_t *l)
{
	*l = __SIMPLELOCK_UNLOCKED;
}

static __inline__ void
__cpu_simple_lock(__cpu_simple_lock_t *l)
{
	__cpu_simple_lock_t old;

	do {
		old = __SIMPLELOCK_LOCKED;
		__asm__ __volatile__
		    ("casl %0, %2, %1" : "+d" (old), "=m" (*l) : "d" (*l));
	} while (old != __SIMPLELOCK_UNLOCKED);
}

static __inline__ int
__cpu_simple_lock_try(__cpu_simple_lock_t *l)
{
	__cpu_simple_lock_t old = __SIMPLELOCK_LOCKED;

	__asm__ __volatile__
	    ("casl %0, %2, %1" : "+d" (old), "=m" (*l) : "d" (*l));

	return (old == __SIMPLELOCK_UNLOCKED);
}

static __inline__ void
__cpu_simple_unlock(__cpu_simple_lock_t *l)
{
	*l = __SIMPLELOCK_UNLOCKED;
}

#endif	/* _M68K_LOCK_H_ */