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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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8f9f55e83e
This effectively reverts commit 61d047be99.
Disabling the IOMMU can potetially allow DMA transactions to
complete without being translated. Leave it enabled, and allow
crash kernel to do the IOMMU reinitialization properly.
Cc: stable@kernel.org
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
107 lines
2.3 KiB
C
107 lines
2.3 KiB
C
/*
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* Architecture specific (i386/x86_64) functions for kexec based crash dumps.
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*
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* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
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*
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* Copyright (C) IBM Corporation, 2004. All rights reserved.
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*
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*/
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/smp.h>
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#include <linux/reboot.h>
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#include <linux/kexec.h>
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#include <linux/delay.h>
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#include <linux/elf.h>
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#include <linux/elfcore.h>
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#include <asm/processor.h>
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#include <asm/hardirq.h>
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#include <asm/nmi.h>
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#include <asm/hw_irq.h>
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#include <asm/apic.h>
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#include <asm/hpet.h>
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#include <linux/kdebug.h>
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#include <asm/cpu.h>
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#include <asm/reboot.h>
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#include <asm/virtext.h>
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#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
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static void kdump_nmi_callback(int cpu, struct die_args *args)
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{
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struct pt_regs *regs;
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#ifdef CONFIG_X86_32
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struct pt_regs fixed_regs;
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#endif
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regs = args->regs;
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#ifdef CONFIG_X86_32
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if (!user_mode_vm(regs)) {
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crash_fixup_ss_esp(&fixed_regs, regs);
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regs = &fixed_regs;
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}
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#endif
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crash_save_cpu(regs, cpu);
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/* Disable VMX or SVM if needed.
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*
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* We need to disable virtualization on all CPUs.
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* Having VMX or SVM enabled on any CPU may break rebooting
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* after the kdump kernel has finished its task.
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*/
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cpu_emergency_vmxoff();
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cpu_emergency_svm_disable();
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disable_local_APIC();
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}
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static void kdump_nmi_shootdown_cpus(void)
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{
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nmi_shootdown_cpus(kdump_nmi_callback);
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disable_local_APIC();
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}
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#else
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static void kdump_nmi_shootdown_cpus(void)
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{
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/* There are no cpus to shootdown */
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}
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#endif
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void native_machine_crash_shutdown(struct pt_regs *regs)
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{
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/* This function is only called after the system
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* has panicked or is otherwise in a critical state.
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* The minimum amount of code to allow a kexec'd kernel
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* to run successfully needs to happen here.
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*
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* In practice this means shooting down the other cpus in
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* an SMP system.
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*/
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/* The kernel is broken so disable interrupts */
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local_irq_disable();
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kdump_nmi_shootdown_cpus();
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/* Booting kdump kernel with VMX or SVM enabled won't work,
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* because (among other limitations) we can't disable paging
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* with the virt flags.
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*/
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cpu_emergency_vmxoff();
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cpu_emergency_svm_disable();
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lapic_shutdown();
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#if defined(CONFIG_X86_IO_APIC)
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disable_IO_APIC();
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#endif
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#ifdef CONFIG_HPET_TIMER
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hpet_disable();
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#endif
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crash_save_cpu(regs, safe_smp_processor_id());
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}
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