blob: 5ad4e1674b9eb4367082a6a1a2f785cb2efc8150 (
plain) (
blame)
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
|
/* $OpenBSD: _atomic_lock.c,v 1.1 2017/08/15 06:13:24 guenther Exp $ */
/*
* Atomic lock for mips
* Written by Miodrag Vallat <miod@openbsd.org> - placed in the public domain.
*/
#include <machine/spinlock.h>
int
_atomic_lock(volatile _atomic_lock_t *lock)
{
_atomic_lock_t old;
__asm__ volatile (
".set noreorder\n"
"1: ll %0, 0(%1)\n"
" sc %2, 0(%1)\n"
" beqz %2, 1b\n"
" addi %2, $0, %3\n"
".set reorder\n"
: "=&r"(old)
: "r"(lock), "r"(_ATOMIC_LOCK_LOCKED), "i"(_ATOMIC_LOCK_LOCKED)
: "memory");
return (old != _ATOMIC_LOCK_UNLOCKED);
}
|
