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 31 32 #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) 33 34 static 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 63 static void kdump_nmi_shootdown_cpus(void) 64 { 65 nmi_shootdown_cpus(kdump_nmi_callback); 66 67 disable_local_APIC(); 68 } 69 70 #else 71 static void kdump_nmi_shootdown_cpus(void) 72 { 73 /* There are no cpus to shootdown */ 74 } 75 #endif 76 77 void 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 crash_save_cpu(regs, safe_smp_processor_id()); 107 } 108