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 int in_crash_kexec; 32 33 #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) 34 35 static 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 61 static 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 70 static void kdump_nmi_shootdown_cpus(void) 71 { 72 /* There are no cpus to shootdown */ 73 } 74 #endif 75 76 void 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