spinlock.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * ARM64 Spinlock support
 4 */
 5#include <stdint.h>
 6
 7#include "spinlock.h"
 8
 9void spin_lock(struct spinlock *lock)
10{
11	int val, res;
12
13	asm volatile(
14	"1:	ldaxr	%w0, [%2]\n"
15	"	cbnz	%w0, 1b\n"
16	"	mov	%w0, #1\n"
17	"	stxr	%w1, %w0, [%2]\n"
18	"	cbnz	%w1, 1b\n"
19	: "=&r" (val), "=&r" (res)
20	: "r" (&lock->v)
21	: "memory");
22}
23
24void spin_unlock(struct spinlock *lock)
25{
26	asm volatile("stlr wzr, [%0]\n"	: : "r" (&lock->v) : "memory");
27}