Atmosphere/libraries/libmesosphere/source/arch/arm64/kern_cpu_asm.s
2020-01-29 04:36:18 -08:00

63 lines
1.7 KiB
ArmAsm

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* ams::kern::arm64::cpu::SynchronizeAllCoresImpl(int *sync_var, int num_cores) */
.section .text._ZN3ams4kern5arm643cpu23SynchronizeAllCoresImplEPii, "ax", %progbits
.global _ZN3ams4kern5arm643cpu23SynchronizeAllCoresImplEPii
.type _ZN3ams4kern5arm643cpu23SynchronizeAllCoresImplEPii, %function
_ZN3ams4kern5arm643cpu23SynchronizeAllCoresImplEPii:
/* Loop until the sync var is less than num cores. */
sevl
1:
wfe
ldaxr w2, [x0]
cmp w2, w1
b.gt 1b
/* Increment the sync var. */
2:
ldaxr w2, [x0]
add w3, w2, #1
stlxr w4, w3, [x0]
cbnz w4, 2b
/* Loop until the sync var matches our ticket. */
add w3, w2, w1
sevl
3:
wfe
ldaxr w2, [x0]
cmp w2, w3
b.ne 3b
/* Check if the ticket is the last. */
sub w2, w1, #1
add w2, w2, w1
cmp w3, w2
b.eq 5f
/* Our ticket is not the last one. Increment. */
4:
ldaxr w2, [x0]
add w3, w2, #1
stlxr w4, w3, [x0]
cbnz w4, 4b
ret
/* Our ticket is the last one. */
5:
stlr wzr, [x0]
ret