f9076ecfb1
Commit 68234df4ea ("arm64: kill flush_cache_all()") removed the global
arm64 routines cpu_reset() and cpu_soft_restart() needed by the arm64
kexec and kdump support. Add back a simplified version of
cpu_soft_restart() with some changes needed for kexec in the new files
cpu_reset.S, and cpu_reset.h.
When a CPU is reset it needs to be put into the exception level it had when
it entered the kernel. Update cpu_soft_restart() to accept an argument
which signals if the reset address should be entered at EL1 or EL2, and
add a new hypercall HVC_SOFT_RESTART which is used for the EL2 switch.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
55 lines
1.4 KiB
ArmAsm
55 lines
1.4 KiB
ArmAsm
/*
|
|
* CPU reset routines
|
|
*
|
|
* Copyright (C) 2001 Deep Blue Solutions Ltd.
|
|
* Copyright (C) 2012 ARM Ltd.
|
|
* Copyright (C) 2015 Huawei Futurewei Technologies.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
#include <asm/sysreg.h>
|
|
#include <asm/virt.h>
|
|
|
|
.text
|
|
.pushsection .idmap.text, "ax"
|
|
|
|
/*
|
|
* __cpu_soft_restart(el2_switch, entry, arg0, arg1, arg2) - Helper for
|
|
* cpu_soft_restart.
|
|
*
|
|
* @el2_switch: Flag to indicate a swich to EL2 is needed.
|
|
* @entry: Location to jump to for soft reset.
|
|
* arg0: First argument passed to @entry.
|
|
* arg1: Second argument passed to @entry.
|
|
* arg2: Third argument passed to @entry.
|
|
*
|
|
* Put the CPU into the same state as it would be if it had been reset, and
|
|
* branch to what would be the reset vector. It must be executed with the
|
|
* flat identity mapping.
|
|
*/
|
|
ENTRY(__cpu_soft_restart)
|
|
/* Clear sctlr_el1 flags. */
|
|
mrs x12, sctlr_el1
|
|
ldr x13, =SCTLR_ELx_FLAGS
|
|
bic x12, x12, x13
|
|
msr sctlr_el1, x12
|
|
isb
|
|
|
|
cbz x0, 1f // el2_switch?
|
|
mov x0, #HVC_SOFT_RESTART
|
|
hvc #0 // no return
|
|
|
|
1: mov x18, x1 // entry
|
|
mov x0, x2 // arg0
|
|
mov x1, x3 // arg1
|
|
mov x2, x4 // arg2
|
|
br x18
|
|
ENDPROC(__cpu_soft_restart)
|
|
|
|
.popsection
|