diff options
Diffstat (limited to 'arch/x86/kernel/reboot.c')
| -rw-r--r-- | arch/x86/kernel/reboot.c | 943 |
1 files changed, 943 insertions, 0 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c new file mode 100644 index 000000000..4d8c0e258 --- /dev/null +++ b/arch/x86/kernel/reboot.c @@ -0,0 +1,943 @@ +// SPDX-License-Identifier: GPL-2.0 +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/export.h> +#include <linux/reboot.h> +#include <linux/init.h> +#include <linux/pm.h> +#include <linux/efi.h> +#include <linux/dmi.h> +#include <linux/sched.h> +#include <linux/tboot.h> +#include <linux/delay.h> +#include <linux/objtool.h> +#include <linux/pgtable.h> +#include <acpi/reboot.h> +#include <asm/io.h> +#include <asm/apic.h> +#include <asm/io_apic.h> +#include <asm/desc.h> +#include <asm/hpet.h> +#include <asm/proto.h> +#include <asm/reboot_fixups.h> +#include <asm/reboot.h> +#include <asm/pci_x86.h> +#include <asm/virtext.h> +#include <asm/cpu.h> +#include <asm/nmi.h> +#include <asm/smp.h> + +#include <linux/ctype.h> +#include <linux/mc146818rtc.h> +#include <asm/realmode.h> +#include <asm/x86_init.h> +#include <asm/efi.h> + +/* + * Power off function, if any + */ +void (*pm_power_off)(void); +EXPORT_SYMBOL(pm_power_off); + +/* + * This is set if we need to go through the 'emergency' path. + * When machine_emergency_restart() is called, we may be on + * an inconsistent state and won't be able to do a clean cleanup + */ +static int reboot_emergency; + +/* This is set by the PCI code if either type 1 or type 2 PCI is detected */ +bool port_cf9_safe = false; + +/* + * Reboot options and system auto-detection code provided by + * Dell Inc. so their systems "just work". :-) + */ + +/* + * Some machines require the "reboot=a" commandline options + */ +static int __init set_acpi_reboot(const struct dmi_system_id *d) +{ + if (reboot_type != BOOT_ACPI) { + reboot_type = BOOT_ACPI; + pr_info("%s series board detected. Selecting %s-method for reboots.\n", + d->ident, "ACPI"); + } + return 0; +} + +/* + * Some machines require the "reboot=b" or "reboot=k" commandline options, + * this quirk makes that automatic. + */ +static int __init set_bios_reboot(const struct dmi_system_id *d) +{ + if (reboot_type != BOOT_BIOS) { + reboot_type = BOOT_BIOS; + pr_info("%s series board detected. Selecting %s-method for reboots.\n", + d->ident, "BIOS"); + } + return 0; +} + +/* + * Some machines don't handle the default ACPI reboot method and + * require the EFI reboot method: + */ +static int __init set_efi_reboot(const struct dmi_system_id *d) +{ + if (reboot_type != BOOT_EFI && !efi_runtime_disabled()) { + reboot_type = BOOT_EFI; + pr_info("%s series board detected. Selecting EFI-method for reboot.\n", d->ident); + } + return 0; +} + +void __noreturn machine_real_restart(unsigned int type) +{ + local_irq_disable(); + + /* + * Write zero to CMOS register number 0x0f, which the BIOS POST + * routine will recognize as telling it to do a proper reboot. (Well + * that's what this book in front of me says -- it may only apply to + * the Phoenix BIOS though, it's not clear). At the same time, + * disable NMIs by setting the top bit in the CMOS address register, + * as we're about to do peculiar things to the CPU. I'm not sure if + * `outb_p' is needed instead of just `outb'. Use it to be on the + * safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.) + */ + spin_lock(&rtc_lock); + CMOS_WRITE(0x00, 0x8f); + spin_unlock(&rtc_lock); + + /* + * Switch to the trampoline page table. + */ + load_trampoline_pgtable(); + + /* Jump to the identity-mapped low memory code */ +#ifdef CONFIG_X86_32 + asm volatile("jmpl *%0" : : + "rm" (real_mode_header->machine_real_restart_asm), + "a" (type)); +#else + asm volatile("ljmpl *%0" : : + "m" (real_mode_header->machine_real_restart_asm), + "D" (type)); +#endif + unreachable(); +} +#ifdef CONFIG_APM_MODULE +EXPORT_SYMBOL(machine_real_restart); +#endif +STACK_FRAME_NON_STANDARD(machine_real_restart); + +/* + * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot + */ +static int __init set_pci_reboot(const struct dmi_system_id *d) +{ + if (reboot_type != BOOT_CF9_FORCE) { + reboot_type = BOOT_CF9_FORCE; + pr_info("%s series board detected. Selecting %s-method for reboots.\n", + d->ident, "PCI"); + } + return 0; +} + +static int __init set_kbd_reboot(const struct dmi_system_id *d) +{ + if (reboot_type != BOOT_KBD) { + reboot_type = BOOT_KBD; + pr_info("%s series board detected. Selecting %s-method for reboot.\n", + d->ident, "KBD"); + } + return 0; +} + +/* + * This is a single dmi_table handling all reboot quirks. + */ +static const struct dmi_system_id reboot_dmi_table[] __initconst = { + + /* Acer */ + { /* Handle reboot issue on Acer Aspire one */ + .callback = set_kbd_reboot, + .ident = "Acer Aspire One A110", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Acer"), + DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"), + }, + }, + { /* Handle reboot issue on Acer TravelMate X514-51T */ + .callback = set_efi_reboot, + .ident = "Acer TravelMate X514-51T", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Acer"), + DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"), + }, + }, + + /* Apple */ + { /* Handle problems with rebooting on Apple MacBook5 */ + .callback = set_pci_reboot, + .ident = "Apple MacBook5", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"), + }, + }, + { /* Handle problems with rebooting on Apple MacBook6,1 */ + .callback = set_pci_reboot, + .ident = "Apple MacBook6,1", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "MacBook6,1"), + }, + }, + { /* Handle problems with rebooting on Apple MacBookPro5 */ + .callback = set_pci_reboot, + .ident = "Apple MacBookPro5", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"), + }, + }, + { /* Handle problems with rebooting on Apple Macmini3,1 */ + .callback = set_pci_reboot, + .ident = "Apple Macmini3,1", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"), + }, + }, + { /* Handle problems with rebooting on the iMac9,1. */ + .callback = set_pci_reboot, + .ident = "Apple iMac9,1", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"), + }, + }, + { /* Handle problems with rebooting on the iMac10,1. */ + .callback = set_pci_reboot, + .ident = "Apple iMac10,1", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"), + }, + }, + + /* ASRock */ + { /* Handle problems with rebooting on ASRock Q1900DC-ITX */ + .callback = set_pci_reboot, + .ident = "ASRock Q1900DC-ITX", + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"), + DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"), + }, + }, + + /* ASUS */ + { /* Handle problems with rebooting on ASUS P4S800 */ + .callback = set_bios_reboot, + .ident = "ASUS P4S800", + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."), + DMI_MATCH(DMI_BOARD_NAME, "P4S800"), + }, + }, + { /* Handle problems with rebooting on ASUS EeeBook X205TA */ + .callback = set_acpi_reboot, + .ident = "ASUS EeeBook X205TA", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"), + }, + }, + { /* Handle problems with rebooting on ASUS EeeBook X205TAW */ + .callback = set_acpi_reboot, + .ident = "ASUS EeeBook X205TAW", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"), + }, + }, + + /* Certec */ + { /* Handle problems with rebooting on Certec BPC600 */ + .callback = set_pci_reboot, + .ident = "Certec BPC600", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Certec"), + DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"), + }, + }, + + /* Dell */ + { /* Handle problems with rebooting on Dell DXP061 */ + .callback = set_bios_reboot, + .ident = "Dell DXP061", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"), + }, + }, + { /* Handle problems with rebooting on Dell E520's */ + .callback = set_bios_reboot, + .ident = "Dell E520", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"), + }, + }, + { /* Handle problems with rebooting on the Latitude E5410. */ + .callback = set_pci_reboot, + .ident = "Dell Latitude E5410", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"), + }, + }, + { /* Handle problems with rebooting on the Latitude E5420. */ + .callback = set_pci_reboot, + .ident = "Dell Latitude E5420", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"), + }, + }, + { /* Handle problems with rebooting on the Latitude E6320. */ + .callback = set_pci_reboot, + .ident = "Dell Latitude E6320", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"), + }, + }, + { /* Handle problems with rebooting on the Latitude E6420. */ + .callback = set_pci_reboot, + .ident = "Dell Latitude E6420", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"), + }, + }, + { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */ + .callback = set_bios_reboot, + .ident = "Dell OptiPlex 330", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"), + DMI_MATCH(DMI_BOARD_NAME, "0KP561"), + }, + }, + { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */ + .callback = set_bios_reboot, + .ident = "Dell OptiPlex 360", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"), + DMI_MATCH(DMI_BOARD_NAME, "0T656F"), + }, + }, + { /* Handle problems with rebooting on Dell Optiplex 745's SFF */ + .callback = set_bios_reboot, + .ident = "Dell OptiPlex 745", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), + }, + }, + { /* Handle problems with rebooting on Dell Optiplex 745's DFF */ + .callback = set_bios_reboot, + .ident = "Dell OptiPlex 745", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), + DMI_MATCH(DMI_BOARD_NAME, "0MM599"), + }, + }, + { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */ + .callback = set_bios_reboot, + .ident = "Dell OptiPlex 745", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), + DMI_MATCH(DMI_BOARD_NAME, "0KW626"), + }, + }, + { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */ + .callback = set_bios_reboot, + .ident = "Dell OptiPlex 760", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"), + DMI_MATCH(DMI_BOARD_NAME, "0G919G"), + }, + }, + { /* Handle problems with rebooting on the OptiPlex 990. */ + .callback = set_pci_reboot, + .ident = "Dell OptiPlex 990 BIOS A0x", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"), + DMI_MATCH(DMI_BIOS_VERSION, "A0"), + }, + }, + { /* Handle problems with rebooting on Dell 300's */ + .callback = set_bios_reboot, + .ident = "Dell PowerEdge 300", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"), + }, + }, + { /* Handle problems with rebooting on Dell 1300's */ + .callback = set_bios_reboot, + .ident = "Dell PowerEdge 1300", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"), + }, + }, + { /* Handle problems with rebooting on Dell 2400's */ + .callback = set_bios_reboot, + .ident = "Dell PowerEdge 2400", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"), + }, + }, + { /* Handle problems with rebooting on the Dell PowerEdge C6100. */ + .callback = set_pci_reboot, + .ident = "Dell PowerEdge C6100", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell"), + DMI_MATCH(DMI_PRODUCT_NAME, "C6100"), + }, + }, + { /* Handle problems with rebooting on the Precision M6600. */ + .callback = set_pci_reboot, + .ident = "Dell Precision M6600", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"), + }, + }, + { /* Handle problems with rebooting on Dell T5400's */ + .callback = set_bios_reboot, + .ident = "Dell Precision T5400", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"), + }, + }, + { /* Handle problems with rebooting on Dell T7400's */ + .callback = set_bios_reboot, + .ident = "Dell Precision T7400", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"), + }, + }, + { /* Handle problems with rebooting on Dell XPS710 */ + .callback = set_bios_reboot, + .ident = "Dell XPS710", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"), + }, + }, + { /* Handle problems with rebooting on Dell Optiplex 7450 AIO */ + .callback = set_acpi_reboot, + .ident = "Dell OptiPlex 7450 AIO", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"), + }, + }, + + /* Hewlett-Packard */ + { /* Handle problems with rebooting on HP laptops */ + .callback = set_bios_reboot, + .ident = "HP Compaq Laptop", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), + DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"), + }, + }, + + { /* PCIe Wifi card isn't detected after reboot otherwise */ + .callback = set_pci_reboot, + .ident = "Zotac ZBOX CI327 nano", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "NA"), + DMI_MATCH(DMI_PRODUCT_NAME, "ZBOX-CI327NANO-GS-01"), + }, + }, + + /* Sony */ + { /* Handle problems with rebooting on Sony VGN-Z540N */ + .callback = set_bios_reboot, + .ident = "Sony VGN-Z540N", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"), + }, + }, + + { } +}; + +static int __init reboot_init(void) +{ + int rv; + + /* + * Only do the DMI check if reboot_type hasn't been overridden + * on the command line + */ + if (!reboot_default) + return 0; + + /* + * The DMI quirks table takes precedence. If no quirks entry + * matches and the ACPI Hardware Reduced bit is set and EFI + * runtime services are enabled, force EFI reboot. + */ + rv = dmi_check_system(reboot_dmi_table); + + if (!rv && efi_reboot_required() && !efi_runtime_disabled()) + reboot_type = BOOT_EFI; + + return 0; +} +core_initcall(reboot_init); + +static inline void kb_wait(void) +{ + int i; + + for (i = 0; i < 0x10000; i++) { + if ((inb(0x64) & 0x02) == 0) + break; + udelay(2); + } +} + +static inline void nmi_shootdown_cpus_on_restart(void); + +static void emergency_reboot_disable_virtualization(void) +{ + /* Just make sure we won't change CPUs while doing this */ + local_irq_disable(); + + /* + * Disable virtualization on all CPUs before rebooting to avoid hanging + * the system, as VMX and SVM block INIT when running in the host. + * + * We can't take any locks and we may be on an inconsistent state, so + * use NMIs as IPIs to tell the other CPUs to disable VMX/SVM and halt. + * + * Do the NMI shootdown even if virtualization is off on _this_ CPU, as + * other CPUs may have virtualization enabled. + */ + if (cpu_has_vmx() || cpu_has_svm(NULL)) { + /* Safely force _this_ CPU out of VMX/SVM operation. */ + cpu_emergency_disable_virtualization(); + + /* Disable VMX/SVM and halt on other CPUs. */ + nmi_shootdown_cpus_on_restart(); + } +} + + +void __attribute__((weak)) mach_reboot_fixups(void) +{ +} + +/* + * To the best of our knowledge Windows compatible x86 hardware expects + * the following on reboot: + * + * 1) If the FADT has the ACPI reboot register flag set, try it + * 2) If still alive, write to the keyboard controller + * 3) If still alive, write to the ACPI reboot register again + * 4) If still alive, write to the keyboard controller again + * 5) If still alive, call the EFI runtime service to reboot + * 6) If no EFI runtime service, call the BIOS to do a reboot + * + * We default to following the same pattern. We also have + * two other reboot methods: 'triple fault' and 'PCI', which + * can be triggered via the reboot= kernel boot option or + * via quirks. + * + * This means that this function can never return, it can misbehave + * by not rebooting properly and hanging. + */ +static void native_machine_emergency_restart(void) +{ + int i; + int attempt = 0; + int orig_reboot_type = reboot_type; + unsigned short mode; + + if (reboot_emergency) + emergency_reboot_disable_virtualization(); + + tboot_shutdown(TB_SHUTDOWN_REBOOT); + + /* Tell the BIOS if we want cold or warm reboot */ + mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0; + *((unsigned short *)__va(0x472)) = mode; + + /* + * If an EFI capsule has been registered with the firmware then + * override the reboot= parameter. + */ + if (efi_capsule_pending(NULL)) { + pr_info("EFI capsule is pending, forcing EFI reboot.\n"); + reboot_type = BOOT_EFI; + } + + for (;;) { + /* Could also try the reset bit in the Hammer NB */ + switch (reboot_type) { + case BOOT_ACPI: + acpi_reboot(); + reboot_type = BOOT_KBD; + break; + + case BOOT_KBD: + mach_reboot_fixups(); /* For board specific fixups */ + + for (i = 0; i < 10; i++) { + kb_wait(); + udelay(50); + outb(0xfe, 0x64); /* Pulse reset low */ + udelay(50); + } + if (attempt == 0 && orig_reboot_type == BOOT_ACPI) { + attempt = 1; + reboot_type = BOOT_ACPI; + } else { + reboot_type = BOOT_EFI; + } + break; + + case BOOT_EFI: + efi_reboot(reboot_mode, NULL); + reboot_type = BOOT_BIOS; + break; + + case BOOT_BIOS: + machine_real_restart(MRR_BIOS); + + /* We're probably dead after this, but... */ + reboot_type = BOOT_CF9_SAFE; + break; + + case BOOT_CF9_FORCE: + port_cf9_safe = true; + fallthrough; + + case BOOT_CF9_SAFE: + if (port_cf9_safe) { + u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E; + u8 cf9 = inb(0xcf9) & ~reboot_code; + outb(cf9|2, 0xcf9); /* Request hard reset */ + udelay(50); + /* Actually do the reset */ + outb(cf9|reboot_code, 0xcf9); + udelay(50); + } + reboot_type = BOOT_TRIPLE; + break; + + case BOOT_TRIPLE: + idt_invalidate(NULL); + __asm__ __volatile__("int3"); + + /* We're probably dead after this, but... */ + reboot_type = BOOT_KBD; + break; + } + } +} + +void native_machine_shutdown(void) +{ + /* Stop the cpus and apics */ +#ifdef CONFIG_X86_IO_APIC + /* + * Disabling IO APIC before local APIC is a workaround for + * erratum AVR31 in "Intel Atom Processor C2000 Product Family + * Specification Update". In this situation, interrupts that target + * a Logical Processor whose Local APIC is either in the process of + * being hardware disabled or software disabled are neither delivered + * nor discarded. When this erratum occurs, the processor may hang. + * + * Even without the erratum, it still makes sense to quiet IO APIC + * before disabling Local APIC. + */ + clear_IO_APIC(); +#endif + +#ifdef CONFIG_SMP + /* + * Stop all of the others. Also disable the local irq to + * not receive the per-cpu timer interrupt which may trigger + * scheduler's load balance. + */ + local_irq_disable(); + stop_other_cpus(); +#endif + + lapic_shutdown(); + restore_boot_irq_mode(); + +#ifdef CONFIG_HPET_TIMER + hpet_disable(); +#endif + +#ifdef CONFIG_X86_64 + x86_platform.iommu_shutdown(); +#endif +} + +static void __machine_emergency_restart(int emergency) +{ + reboot_emergency = emergency; + machine_ops.emergency_restart(); +} + +static void native_machine_restart(char *__unused) +{ + pr_notice("machine restart\n"); + + if (!reboot_force) + machine_shutdown(); + __machine_emergency_restart(0); +} + +static void native_machine_halt(void) +{ + /* Stop other cpus and apics */ + machine_shutdown(); + + tboot_shutdown(TB_SHUTDOWN_HALT); + + stop_this_cpu(NULL); +} + +static void native_machine_power_off(void) +{ + if (pm_power_off) { + if (!reboot_force) + machine_shutdown(); + pm_power_off(); + } + /* A fallback in case there is no PM info available */ + tboot_shutdown(TB_SHUTDOWN_HALT); +} + +struct machine_ops machine_ops __ro_after_init = { + .power_off = native_machine_power_off, + .shutdown = native_machine_shutdown, + .emergency_restart = native_machine_emergency_restart, + .restart = native_machine_restart, + .halt = native_machine_halt, +#ifdef CONFIG_KEXEC_CORE + .crash_shutdown = native_machine_crash_shutdown, +#endif +}; + +void machine_power_off(void) +{ + machine_ops.power_off(); +} + +void machine_shutdown(void) +{ + machine_ops.shutdown(); +} + +void machine_emergency_restart(void) +{ + __machine_emergency_restart(1); +} + +void machine_restart(char *cmd) +{ + machine_ops.restart(cmd); +} + +void machine_halt(void) +{ + machine_ops.halt(); +} + +#ifdef CONFIG_KEXEC_CORE +void machine_crash_shutdown(struct pt_regs *regs) +{ + machine_ops.crash_shutdown(regs); +} +#endif + + +/* This is the CPU performing the emergency shutdown work. */ +int crashing_cpu = -1; + +/* + * Disable virtualization, i.e. VMX or SVM, to ensure INIT is recognized during + * reboot. VMX blocks INIT if the CPU is post-VMXON, and SVM blocks INIT if + * GIF=0, i.e. if the crash occurred between CLGI and STGI. + */ +void cpu_emergency_disable_virtualization(void) +{ + cpu_emergency_vmxoff(); + cpu_emergency_svm_disable(); +} + +#if defined(CONFIG_SMP) + +static nmi_shootdown_cb shootdown_callback; + +static atomic_t waiting_for_crash_ipi; +static int crash_ipi_issued; + +static int crash_nmi_callback(unsigned int val, struct pt_regs *regs) +{ + int cpu; + + cpu = raw_smp_processor_id(); + + /* + * Don't do anything if this handler is invoked on crashing cpu. + * Otherwise, system will completely hang. Crashing cpu can get + * an NMI if system was initially booted with nmi_watchdog parameter. + */ + if (cpu == crashing_cpu) + return NMI_HANDLED; + local_irq_disable(); + + if (shootdown_callback) + shootdown_callback(cpu, regs); + + /* + * Prepare the CPU for reboot _after_ invoking the callback so that the + * callback can safely use virtualization instructions, e.g. VMCLEAR. + */ + cpu_emergency_disable_virtualization(); + + atomic_dec(&waiting_for_crash_ipi); + /* Assume hlt works */ + halt(); + for (;;) + cpu_relax(); + + return NMI_HANDLED; +} + +/** + * nmi_shootdown_cpus - Stop other CPUs via NMI + * @callback: Optional callback to be invoked from the NMI handler + * + * The NMI handler on the remote CPUs invokes @callback, if not + * NULL, first and then disables virtualization to ensure that + * INIT is recognized during reboot. + * + * nmi_shootdown_cpus() can only be invoked once. After the first + * invocation all other CPUs are stuck in crash_nmi_callback() and + * cannot respond to a second NMI. + */ +void nmi_shootdown_cpus(nmi_shootdown_cb callback) +{ + unsigned long msecs; + + local_irq_disable(); + + /* + * Avoid certain doom if a shootdown already occurred; re-registering + * the NMI handler will cause list corruption, modifying the callback + * will do who knows what, etc... + */ + if (WARN_ON_ONCE(crash_ipi_issued)) + return; + + /* Make a note of crashing cpu. Will be used in NMI callback. */ + crashing_cpu = safe_smp_processor_id(); + + shootdown_callback = callback; + + atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); + /* Would it be better to replace the trap vector here? */ + if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback, + NMI_FLAG_FIRST, "crash")) + return; /* Return what? */ + /* + * Ensure the new callback function is set before sending + * out the NMI + */ + wmb(); + + apic_send_IPI_allbutself(NMI_VECTOR); + + /* Kick CPUs looping in NMI context. */ + WRITE_ONCE(crash_ipi_issued, 1); + + msecs = 1000; /* Wait at most a second for the other cpus to stop */ + while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { + mdelay(1); + msecs--; + } + + /* + * Leave the nmi callback set, shootdown is a one-time thing. Clearing + * the callback could result in a NULL pointer dereference if a CPU + * (finally) responds after the timeout expires. + */ +} + +static inline void nmi_shootdown_cpus_on_restart(void) +{ + if (!crash_ipi_issued) + nmi_shootdown_cpus(NULL); +} + +/* + * Check if the crash dumping IPI got issued and if so, call its callback + * directly. This function is used when we have already been in NMI handler. + * It doesn't return. + */ +void run_crash_ipi_callback(struct pt_regs *regs) +{ + if (crash_ipi_issued) + crash_nmi_callback(0, regs); +} + +/* Override the weak function in kernel/panic.c */ +void nmi_panic_self_stop(struct pt_regs *regs) +{ + while (1) { + /* If no CPU is preparing crash dump, we simply loop here. */ + run_crash_ipi_callback(regs); + cpu_relax(); + } +} + +#else /* !CONFIG_SMP */ +void nmi_shootdown_cpus(nmi_shootdown_cb callback) +{ + /* No other CPUs to shoot down */ +} + +static inline void nmi_shootdown_cpus_on_restart(void) { } + +void run_crash_ipi_callback(struct pt_regs *regs) +{ +} +#endif |