linux_dsm_epyc7002/arch/arm64/kernel/cpu-reset.S
AKASHI Takahiro 4c9e7e649a arm64: kexec_file: invoke the kernel without purgatory
On arm64, purgatory would do almost nothing. So just invoke secondary
kernel directly by jumping into its entry code.

While, in this case, cpu_soft_restart() must be called with dtb address
in the fifth argument, the behavior still stays compatible with kexec_load
case as long as the argument is null.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: James Morse <james.morse@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-06 14:38:53 +00:00

56 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, "awx"
/*
* __cpu_soft_restart(el2_switch, entry, arg0, arg1, arg2) - Helper for
* cpu_soft_restart.
*
* @el2_switch: Flag to indicate a switch to EL2 is needed.
* @entry: Location to jump to for soft reset.
* arg0: First argument passed to @entry. (relocation list)
* arg1: Second argument passed to @entry.(physical kernel entry)
* arg2: Third argument passed to @entry. (physical dtb address)
*
* 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
pre_disable_mmu_workaround
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