summaryrefslogtreecommitdiff
path: root/sys/arch/sparc64/include/lock.h
blob: 0e873b3955be6cfad6c56f0c85d043514af5dce5 (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
49
50
51
52
53
54
55
56
/*	$OpenBSD: lock.h,v 1.5 2010/04/27 21:15:01 kettenis Exp $	*/

/* public domain */

#ifndef	_SPARC64_LOCK_H_
#define	_SPARC64_LOCK_H_

#include <machine/atomic.h>
#include <machine/ctlreg.h>

typedef volatile u_int8_t __cpu_simple_lock_t;

#define	__SIMPLELOCK_LOCKED	0xff
#define	__SIMPLELOCK_UNLOCKED	0x00

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__
		    ("ldstub [%0], %1" : "=r" (l), "=r" (old) : "0" (l));
		membar(LoadLoad | LoadStore);
	} 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__
	    ("ldstub [%0], %1" : "=r" (l), "=r" (old) : "0" (l));
	membar(LoadLoad | LoadStore);

	return (old == __SIMPLELOCK_UNLOCKED);
}

static __inline__ void
__cpu_simple_unlock(__cpu_simple_lock_t *l)
{
	membar(StoreStore | LoadStore);
	*l = __SIMPLELOCK_UNLOCKED;
}

#define	rw_cas(p, o, n)		(sparc64_casx(p, o, n) != o)

#endif	/* _SPARC64_LOCK_H_ */