xref: /openbmc/linux/arch/arm64/kernel/cpu-reset.S (revision 4f6cce39)
1/*
2 * CPU reset routines
3 *
4 * Copyright (C) 2001 Deep Blue Solutions Ltd.
5 * Copyright (C) 2012 ARM Ltd.
6 * Copyright (C) 2015 Huawei Futurewei Technologies.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15#include <asm/sysreg.h>
16#include <asm/virt.h>
17
18.text
19.pushsection    .idmap.text, "ax"
20
21/*
22 * __cpu_soft_restart(el2_switch, entry, arg0, arg1, arg2) - Helper for
23 * cpu_soft_restart.
24 *
25 * @el2_switch: Flag to indicate a swich to EL2 is needed.
26 * @entry: Location to jump to for soft reset.
27 * arg0: First argument passed to @entry.
28 * arg1: Second argument passed to @entry.
29 * arg2: Third argument passed to @entry.
30 *
31 * Put the CPU into the same state as it would be if it had been reset, and
32 * branch to what would be the reset vector. It must be executed with the
33 * flat identity mapping.
34 */
35ENTRY(__cpu_soft_restart)
36	/* Clear sctlr_el1 flags. */
37	mrs	x12, sctlr_el1
38	ldr	x13, =SCTLR_ELx_FLAGS
39	bic	x12, x12, x13
40	msr	sctlr_el1, x12
41	isb
42
43	cbz	x0, 1f				// el2_switch?
44	mov	x0, #HVC_SOFT_RESTART
45	hvc	#0				// no return
46
471:	mov	x18, x1				// entry
48	mov	x0, x2				// arg0
49	mov	x1, x3				// arg1
50	mov	x2, x4				// arg2
51	br	x18
52ENDPROC(__cpu_soft_restart)
53
54.popsection
55