LXR linux/arch/x86/kernel/crash.c

   1/*
   2 * Architecture specific (i386/x86_64) functions for kexec based crash dumps.
   3 *
   4 * Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
   5 *
   6 * Copyright (C) IBM Corporation, 2004. All rights reserved.
   7 *
   8 */
   9
  10#include <linux/init.h>
  11#include <linux/types.h>
  12#include <linux/kernel.h>
  13#include <linux/smp.h>
  14#include <linux/reboot.h>
  15#include <linux/kexec.h>
  16#include <linux/delay.h>
  17#include <linux/elf.h>
  18#include <linux/elfcore.h>
  19
  20#include <asm/processor.h>
  21#include <asm/hardirq.h>
  22#include <asm/nmi.h>
  23#include <asm/hw_irq.h>
  24#include <asm/apic.h>
  25#include <asm/hpet.h>
  26#include <linux/kdebug.h>
  27#include <asm/cpu.h>
  28#include <asm/reboot.h>
  29#include <asm/virtext.h>
  30#include <asm/iommu.h>
  31
  32
  33#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
  34
  35static void kdump_nmi_callback(int cpu, struct die_args *args)
  36{
  37        struct pt_regs *regs;
  38#ifdef CONFIG_X86_32
  39        struct pt_regs fixed_regs;
  40#endif
  41
  42        regs = args->regs;
  43
  44#ifdef CONFIG_X86_32
  45        if (!user_mode_vm(regs)) {
  46                crash_fixup_ss_esp(&fixed_regs, regs);
  47                regs = &fixed_regs;
  48        }
  49#endif
  50        crash_save_cpu(regs, cpu);
  51
  52        /* Disable VMX or SVM if needed.
  53         *
  54         * We need to disable virtualization on all CPUs.
  55         * Having VMX or SVM enabled on any CPU may break rebooting
  56         * after the kdump kernel has finished its task.
  57         */
  58        cpu_emergency_vmxoff();
  59        cpu_emergency_svm_disable();
  60
  61        disable_local_APIC();
  62}
  63
  64static void kdump_nmi_shootdown_cpus(void)
  65{
  66        nmi_shootdown_cpus(kdump_nmi_callback);
  67
  68        disable_local_APIC();
  69}
  70
  71#else
  72static void kdump_nmi_shootdown_cpus(void)
  73{
  74        /* There are no cpus to shootdown */
  75}
  76#endif
  77
  78void native_machine_crash_shutdown(struct pt_regs *regs)
  79{
  80        /* This function is only called after the system
  81         * has panicked or is otherwise in a critical state.
  82         * The minimum amount of code to allow a kexec'd kernel
  83         * to run successfully needs to happen here.
  84         *
  85         * In practice this means shooting down the other cpus in
  86         * an SMP system.
  87         */
  88        /* The kernel is broken so disable interrupts */
  89        local_irq_disable();
  90
  91        kdump_nmi_shootdown_cpus();
  92
  93        /* Booting kdump kernel with VMX or SVM enabled won't work,
  94         * because (among other limitations) we can't disable paging
  95         * with the virt flags.
  96         */
  97        cpu_emergency_vmxoff();
  98        cpu_emergency_svm_disable();
  99
 100        lapic_shutdown();
 101#if defined(CONFIG_X86_IO_APIC)
 102        disable_IO_APIC();
 103#endif
 104#ifdef CONFIG_HPET_TIMER
 105        hpet_disable();
 106#endif
 107
 108#ifdef CONFIG_X86_64
 109        pci_iommu_shutdown();
 110#endif
 111
 112        crash_save_cpu(regs, safe_smp_processor_id());
 113}
 114