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/x86_init.h>
  31
  32#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
  33
  34static void kdump_nmi_callback(int cpu, struct die_args *args)
  35{
  36        struct pt_regs *regs;
  37#ifdef CONFIG_X86_32
  38        struct pt_regs fixed_regs;
  39#endif
  40
  41        regs = args->regs;
  42
  43#ifdef CONFIG_X86_32
  44        if (!user_mode_vm(regs)) {
  45                crash_fixup_ss_esp(&fixed_regs, regs);
  46                regs = &fixed_regs;
  47        }
  48#endif
  49        crash_save_cpu(regs, cpu);
  50
  51        /* Disable VMX or SVM if needed.
  52         *
  53         * We need to disable virtualization on all CPUs.
  54         * Having VMX or SVM enabled on any CPU may break rebooting
  55         * after the kdump kernel has finished its task.
  56         */
  57        cpu_emergency_vmxoff();
  58        cpu_emergency_svm_disable();
  59
  60        disable_local_APIC();
  61}
  62
  63static void kdump_nmi_shootdown_cpus(void)
  64{
  65        nmi_shootdown_cpus(kdump_nmi_callback);
  66
  67        disable_local_APIC();
  68}
  69
  70#else
  71static void kdump_nmi_shootdown_cpus(void)
  72{
  73        /* There are no cpus to shootdown */
  74}
  75#endif
  76
  77void native_machine_crash_shutdown(struct pt_regs *regs)
  78{
  79        /* This function is only called after the system
  80         * has panicked or is otherwise in a critical state.
  81         * The minimum amount of code to allow a kexec'd kernel
  82         * to run successfully needs to happen here.
  83         *
  84         * In practice this means shooting down the other cpus in
  85         * an SMP system.
  86         */
  87        /* The kernel is broken so disable interrupts */
  88        local_irq_disable();
  89
  90        kdump_nmi_shootdown_cpus();
  91
  92        /* Booting kdump kernel with VMX or SVM enabled won't work,
  93         * because (among other limitations) we can't disable paging
  94         * with the virt flags.
  95         */
  96        cpu_emergency_vmxoff();
  97        cpu_emergency_svm_disable();
  98
  99        lapic_shutdown();
 100#if defined(CONFIG_X86_IO_APIC)
 101        disable_IO_APIC();
 102#endif
 103#ifdef CONFIG_HPET_TIMER
 104        hpet_disable();
 105#endif
 106
 107#ifdef CONFIG_X86_64
 108        x86_platform.iommu_shutdown();
 109#endif
 110
 111        crash_save_cpu(regs, safe_smp_processor_id());
 112}
 113