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
  31int in_crash_kexec;
  32
  33#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
  34
  35static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
  36{
  37#ifdef CONFIG_X86_32
  38        struct pt_regs fixed_regs;
  39#endif
  40
  41#ifdef CONFIG_X86_32
  42        if (!user_mode_vm(regs)) {
  43                crash_fixup_ss_esp(&fixed_regs, regs);
  44                regs = &fixed_regs;
  45        }
  46#endif
  47        crash_save_cpu(regs, cpu);
  48
  49        /* Disable VMX or SVM if needed.
  50         *
  51         * We need to disable virtualization on all CPUs.
  52         * Having VMX or SVM enabled on any CPU may break rebooting
  53         * after the kdump kernel has finished its task.
  54         */
  55        cpu_emergency_vmxoff();
  56        cpu_emergency_svm_disable();
  57
  58        disable_local_APIC();
  59}
  60
  61static void kdump_nmi_shootdown_cpus(void)
  62{
  63        in_crash_kexec = 1;
  64        nmi_shootdown_cpus(kdump_nmi_callback);
  65
  66        disable_local_APIC();
  67}
  68
  69#else
  70static void kdump_nmi_shootdown_cpus(void)
  71{
  72        /* There are no cpus to shootdown */
  73}
  74#endif
  75
  76void native_machine_crash_shutdown(struct pt_regs *regs)
  77{
  78        /* This function is only called after the system
  79         * has panicked or is otherwise in a critical state.
  80         * The minimum amount of code to allow a kexec'd kernel
  81         * to run successfully needs to happen here.
  82         *
  83         * In practice this means shooting down the other cpus in
  84         * an SMP system.
  85         */
  86        /* The kernel is broken so disable interrupts */
  87        local_irq_disable();
  88
  89        kdump_nmi_shootdown_cpus();
  90
  91        /* Booting kdump kernel with VMX or SVM enabled won't work,
  92         * because (among other limitations) we can't disable paging
  93         * with the virt flags.
  94         */
  95        cpu_emergency_vmxoff();
  96        cpu_emergency_svm_disable();
  97
  98        lapic_shutdown();
  99#if defined(CONFIG_X86_IO_APIC)
 100        disable_IO_APIC();
 101#endif
 102#ifdef CONFIG_HPET_TIMER
 103        hpet_disable();
 104#endif
 105        crash_save_cpu(regs, safe_smp_processor_id());
 106}
 107