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 35 static 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 64 static void kdump_nmi_shootdown_cpus(void) 65 { 66 nmi_shootdown_cpus(kdump_nmi_callback); 67 68 disable_local_APIC(); 69 } 70 71 #else 72 static void kdump_nmi_shootdown_cpus(void) 73 { 74 /* There are no cpus to shootdown */ 75 } 76 #endif 77 78 void 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