1 // SPDX-License-Identifier: GPL-2.0
5 #include <linux/reboot.h>
15 #include <acpi/reboot.h>
23 #include <asm/reboot.h>
52  * Reboot options and system auto-detection code provided by
53  * Dell Inc. so their systems "just work". :-)
57  * Some machines require the "reboot=a" commandline options
63 		pr_info("%s series board detected. Selecting %s-method for reboots.\n",  in set_acpi_reboot()
64 			d->ident, "ACPI");  in set_acpi_reboot()
70  * Some machines require the "reboot=b" or "reboot=k"  commandline options,
77 		pr_info("%s series board detected. Selecting %s-method for reboots.\n",  in set_bios_reboot()
78 			d->ident, "BIOS");  in set_bios_reboot()
84  * Some machines don't handle the default ACPI reboot method and
85  * require the EFI reboot method:
91 		pr_info("%s series board detected. Selecting EFI-method for reboot.\n", d->ident);  in set_efi_reboot()
102 	 * routine will recognize as telling it to do a proper reboot.  (Well  in machine_real_restart()
103 	 * that's what this book in front of me says -- it may only apply to  in machine_real_restart()
108 	 * safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)  in machine_real_restart()
119 	/* Jump to the identity-mapped low memory code */  in machine_real_restart()
122 		     "rm" (real_mode_header->machine_real_restart_asm),  in machine_real_restart()
126 		     "m" (real_mode_header->machine_real_restart_asm),  in machine_real_restart()
137  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
143 		pr_info("%s series board detected. Selecting %s-method for reboots.\n",  in set_pci_reboot()
144 			d->ident, "PCI");  in set_pci_reboot()
153 		pr_info("%s series board detected. Selecting %s-method for reboot.\n",  in set_kbd_reboot()
154 			d->ident, "KBD");  in set_kbd_reboot()
160  * This is a single dmi_table handling all reboot quirks.
165 	{	/* Handle reboot issue on Acer Aspire one */
173 	{	/* Handle reboot issue on Acer TravelMate X514-51T */
175 		.ident = "Acer TravelMate X514-51T",
178 			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"),
233 	{	/* Handle problems with rebooting on ASRock Q1900DC-ITX */
235 		.ident = "ASRock Q1900DC-ITX",
238 			DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
462 	/* Hewlett-Packard */
467 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
472 	{	/* PCIe Wifi card isn't detected after reboot otherwise */
477 			DMI_MATCH(DMI_PRODUCT_NAME, "ZBOX-CI327NANO-GS-01"),
482 	{	/* Handle problems with rebooting on Sony VGN-Z540N */
484 		.ident = "Sony VGN-Z540N",
487 			DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
508 	 * runtime services are enabled, force EFI reboot.  in reboot_init()
533 /* RCU-protected callback to disable virtualization prior to reboot. */
557  * reboot.  VMX blocks INIT if the CPU is post-VMXON, and SVM blocks INIT if
610  * the following on reboot:
612  * 1) If the FADT has the ACPI reboot register flag set, try it
614  * 3) If still alive, write to the ACPI reboot register again
616  * 5) If still alive, call the EFI runtime service to reboot
617  * 6) If no EFI runtime service, call the BIOS to do a reboot
620  * two other reboot methods: 'triple fault' and 'PCI', which
621  * can be triggered via the reboot= kernel boot option or
632 	unsigned short mode;  in native_machine_emergency_restart()  local
639 	/* Tell the BIOS if we want cold or warm reboot */  in native_machine_emergency_restart()
640 	mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;  in native_machine_emergency_restart()
641 	*((unsigned short *)__va(0x472)) = mode;  in native_machine_emergency_restart()
645 	 * override the reboot= parameter.  in native_machine_emergency_restart()
648 		pr_info("EFI capsule is pending, forcing EFI reboot.\n");  in native_machine_emergency_restart()
738 	 * not receive the per-cpu timer interrupt which may trigger  in native_machine_shutdown()
837 int crashing_cpu = -1;
865 	 * Prepare the CPU for reboot _after_ invoking the callback so that the  in crash_nmi_callback()
880  * nmi_shootdown_cpus - Stop other CPUs via NMI
885  * INIT is recognized during reboot.
898 	 * Avoid certain doom if a shootdown already occurred; re-registering  in nmi_shootdown_cpus()
910 	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);  in nmi_shootdown_cpus()
929 		msecs--;  in nmi_shootdown_cpus()
933 	 * Leave the nmi callback set, shootdown is a one-time thing.  Clearing  in nmi_shootdown_cpus()