xref: /openbmc/linux/arch/arm64/kernel/cpu-reset.S (revision 1dd0dd0b)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * CPU reset routines
4 *
5 * Copyright (C) 2001 Deep Blue Solutions Ltd.
6 * Copyright (C) 2012 ARM Ltd.
7 * Copyright (C) 2015 Huawei Futurewei Technologies.
8 */
9
10#include <linux/linkage.h>
11#include <asm/assembler.h>
12#include <asm/sysreg.h>
13#include <asm/virt.h>
14
15.text
16.pushsection    .idmap.text, "awx"
17
18/*
19 * cpu_soft_restart(el2_switch, entry, arg0, arg1, arg2)
20 *
21 * @el2_switch: Flag to indicate a switch to EL2 is needed.
22 * @entry: Location to jump to for soft reset.
23 * arg0: First argument passed to @entry. (relocation list)
24 * arg1: Second argument passed to @entry.(physical kernel entry)
25 * arg2: Third argument passed to @entry. (physical dtb address)
26 *
27 * Put the CPU into the same state as it would be if it had been reset, and
28 * branch to what would be the reset vector. It must be executed with the
29 * flat identity mapping.
30 */
31SYM_CODE_START(cpu_soft_restart)
32	mov_q	x12, INIT_SCTLR_EL1_MMU_OFF
33	pre_disable_mmu_workaround
34	/*
35	 * either disable EL1&0 translation regime or disable EL2&0 translation
36	 * regime if HCR_EL2.E2H == 1
37	 */
38	msr	sctlr_el1, x12
39	isb
40
41	cbz	x0, 1f				// el2_switch?
42	mov	x0, #HVC_SOFT_RESTART
43	hvc	#0				// no return
44
451:	mov	x8, x1				// entry
46	mov	x0, x2				// arg0
47	mov	x1, x3				// arg1
48	mov	x2, x4				// arg2
49	br	x8
50SYM_CODE_END(cpu_soft_restart)
51
52.popsection
53