ardix/arch/at91sam3x8e/atom_get_put.S

46 lines
1.3 KiB
ArmAsm

/* See the end of this file for copyright, license, and warranty information. */
.include "asm.S"
.text
/* int _atom_get(int *count); */
func_begin _atom_get
ldrex r1, [r0] /* int tmp = atom->count */
add r2, r1, #1 /* int newval = tmp + 1 */
strex r3, r2, [r0] /* atom->count = newval */
teq r3, #0 /* store successful? */
bne _atom_get /* -> goto _atom_get to try again if not */
dmb /* data memory barrier */
mov r0, r2 /* return newval */
bx lr
func_end _atom_get
/* int _atom_put(int *count); */
func_begin _atom_put
ldrex r1, [r0] /* int tmp = atom->count */
sub r2, r1, #1 /* int newval = tmp - 1 */
strex r3, r2, [r0] /* atom->count = newval */
teq r3, #0 /* store successful? */
bne _atom_put /* -> goto _atom_put to try again if not */
dmb /* data memory barrier */
mov r0, r2 /* return newval */
bx lr
func_end _atom_put
/*
* This file is part of Ardix.
* Copyright (c) 2021 Felix Kopp <owo@fef.moe>.
*
* Ardix is non-violent software: you may only use, redistribute,
* and/or modify it under the terms of the CNPLv6+ as found in
* the LICENSE file in the source code root directory or at
* <https://git.pixie.town/thufie/CNPL>.
*
* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
* permitted by applicable law. See the CNPLv6+ for details.
*/