v4.19.13 snapshot.
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
new file mode 100644
index 0000000..725624b
--- /dev/null
+++ b/arch/x86/kernel/reboot.c
@@ -0,0 +1,887 @@
+// 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/frame.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/pgtable.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;
+}
+
+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 back to the initial page table.
+ */
+#ifdef CONFIG_X86_32
+ load_cr3(initial_page_table);
+#else
+ write_cr3(real_mode_header->trampoline_pgd);
+
+ /* Exiting long mode will fail if CR4.PCIDE is set. */
+ if (static_cpu_has(X86_FEATURE_PCID))
+ cr4_clear_bits(X86_CR4_PCIDE);
+#endif
+
+ /* 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"),
+ },
+ },
+
+ /* 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 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",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+ DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
+ },
+ },
+ { /* 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"),
+ },
+ },
+
+ /* 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 void vmxoff_nmi(int cpu, struct pt_regs *regs)
+{
+ cpu_emergency_vmxoff();
+}
+
+/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
+static void emergency_vmx_disable_all(void)
+{
+ /* Just make sure we won't change CPUs while doing this */
+ local_irq_disable();
+
+ /*
+ * We need to disable VMX on all CPUs before rebooting, otherwise
+ * we risk hanging up the machine, because the CPU ignore INIT
+ * signals when VMX is enabled.
+ *
+ * We can't take any locks and we may be on an inconsistent
+ * state, so we use NMIs as IPIs to tell the other CPUs to disable
+ * VMX and halt.
+ *
+ * For safety, we will avoid running the nmi_shootdown_cpus()
+ * stuff unnecessarily, but we don't have a way to check
+ * if other CPUs have VMX enabled. So we will call it only if the
+ * CPU we are running on has VMX enabled.
+ *
+ * We will miss cases where VMX is not enabled on all CPUs. This
+ * shouldn't do much harm because KVM always enable VMX on all
+ * CPUs anyway. But we can miss it on the small window where KVM
+ * is still enabling VMX.
+ */
+ if (cpu_has_vmx() && cpu_vmx_enabled()) {
+ /* Disable VMX on this CPU. */
+ cpu_vmxoff();
+
+ /* Halt and disable VMX on the other CPUs */
+ nmi_shootdown_cpus(vmxoff_nmi);
+
+ }
+}
+
+
+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_vmx_disable_all();
+
+ 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;
+ /* Fall through */
+
+ 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;
+
+#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();
+
+ shootdown_callback(cpu, regs);
+
+ atomic_dec(&waiting_for_crash_ipi);
+ /* Assume hlt works */
+ halt();
+ for (;;)
+ cpu_relax();
+
+ return NMI_HANDLED;
+}
+
+static void smp_send_nmi_allbutself(void)
+{
+ apic->send_IPI_allbutself(NMI_VECTOR);
+}
+
+/*
+ * Halt all other CPUs, calling the specified function on each of them
+ *
+ * This function can be used to halt all other CPUs on crash
+ * or emergency reboot time. The function passed as parameter
+ * will be called inside a NMI handler on all CPUs.
+ */
+void nmi_shootdown_cpus(nmi_shootdown_cb callback)
+{
+ unsigned long msecs;
+ local_irq_disable();
+
+ /* 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();
+
+ smp_send_nmi_allbutself();
+
+ /* 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 */
+}
+
+/*
+ * 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 */
+}
+
+void run_crash_ipi_callback(struct pt_regs *regs)
+{
+}
+#endif