xref: /openbmc/linux/arch/arm64/kernel/cpu-reset.S (revision ecd25094)
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) - Helper for
20 * cpu_soft_restart.
21 *
22 * @el2_switch: Flag to indicate a switch to EL2 is needed.
23 * @entry: Location to jump to for soft reset.
24 * arg0: First argument passed to @entry. (relocation list)
25 * arg1: Second argument passed to @entry.(physical kernel entry)
26 * arg2: Third argument passed to @entry. (physical dtb address)
27 *
28 * Put the CPU into the same state as it would be if it had been reset, and
29 * branch to what would be the reset vector. It must be executed with the
30 * flat identity mapping.
31 */
32ENTRY(__cpu_soft_restart)
33	/* Clear sctlr_el1 flags. */
34	mrs	x12, sctlr_el1
35	ldr	x13, =SCTLR_ELx_FLAGS
36	bic	x12, x12, x13
37	pre_disable_mmu_workaround
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	x18, x1				// entry
46	mov	x0, x2				// arg0
47	mov	x1, x3				// arg1
48	mov	x2, x4				// arg2
49	br	x18
50ENDPROC(__cpu_soft_restart)
51
52.popsection
53