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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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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
/*
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* CPU reset routines
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*
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* Copyright (C) 2001 Deep Blue Solutions Ltd.
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* Copyright (C) 2012 ARM Ltd.
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* Copyright (C) 2015 Huawei Futurewei Technologies.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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#include <asm/sysreg.h>
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#include <asm/virt.h>
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.text
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.pushsection .idmap.text, "ax"
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/*
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* __cpu_soft_restart(el2_switch, entry, arg0, arg1, arg2) - Helper for
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* cpu_soft_restart.
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*
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* @el2_switch: Flag to indicate a swich to EL2 is needed.
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* @entry: Location to jump to for soft reset.
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* arg0: First argument passed to @entry.
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* arg1: Second argument passed to @entry.
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* arg2: Third argument passed to @entry.
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*
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* Put the CPU into the same state as it would be if it had been reset, and
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* branch to what would be the reset vector. It must be executed with the
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* flat identity mapping.
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*/
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ENTRY(__cpu_soft_restart)
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/* Clear sctlr_el1 flags. */
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mrs x12, sctlr_el1
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ldr x13, =SCTLR_ELx_FLAGS
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bic x12, x12, x13
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msr sctlr_el1, x12
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isb
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cbz x0, 1f // el2_switch?
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mov x0, #HVC_SOFT_RESTART
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hvc #0 // no return
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1: mov x18, x1 // entry
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mov x0, x2 // arg0
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mov x1, x3 // arg1
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mov x2, x4 // arg2
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br x18
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ENDPROC(__cpu_soft_restart)
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.popsection
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