1 // SPDX-License-Identifier: GPL-2.0
5 #include <linux/reboot.h>
15 #include <acpi/reboot.h>
23 #include <asm/reboot.h>
53  * Reboot options and system auto-detection code provided by
54  * Dell Inc. so their systems "just work". :-)
58  * Some machines require the "reboot=a" commandline options
64 		pr_info("%s series board detected. Selecting %s-method for reboots.\n",  in set_acpi_reboot()
65 			d->ident, "ACPI");  in set_acpi_reboot()
71  * Some machines require the "reboot=b" or "reboot=k"  commandline options,
78 		pr_info("%s series board detected. Selecting %s-method for reboots.\n",  in set_bios_reboot()
79 			d->ident, "BIOS");  in set_bios_reboot()
85  * Some machines don't handle the default ACPI reboot method and
86  * require the EFI reboot method:
92 		pr_info("%s series board detected. Selecting EFI-method for reboot.\n", d->ident);  in set_efi_reboot()
103 	 * routine will recognize as telling it to do a proper reboot.  (Well  in machine_real_restart()
104 	 * that's what this book in front of me says -- it may only apply to  in machine_real_restart()
109 	 * safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)  in machine_real_restart()
121 	write_cr3(real_mode_header->trampoline_pgd);  in machine_real_restart()
123 	/* Exiting long mode will fail if CR4.PCIDE is set. */  in machine_real_restart()
128 	/* Jump to the identity-mapped low memory code */  in machine_real_restart()
131 		     "rm" (real_mode_header->machine_real_restart_asm),  in machine_real_restart()
135 		     "m" (real_mode_header->machine_real_restart_asm),  in machine_real_restart()
146  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
152 		pr_info("%s series board detected. Selecting %s-method for reboots.\n",  in set_pci_reboot()
153 			d->ident, "PCI");  in set_pci_reboot()
162 		pr_info("%s series board detected. Selecting %s-method for reboot.\n",  in set_kbd_reboot()
163 			d->ident, "KBD");  in set_kbd_reboot()
169  * This is a single dmi_table handling all reboot quirks.
174 	{	/* Handle reboot issue on Acer Aspire one */
182 	{	/* Handle reboot issue on Acer TravelMate X514-51T */
184 		.ident = "Acer TravelMate X514-51T",
187 			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"),
242 	{	/* Handle problems with rebooting on ASRock Q1900DC-ITX */
244 		.ident = "ASRock Q1900DC-ITX",
247 			DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
470 	/* Hewlett-Packard */
475 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
481 	{	/* Handle problems with rebooting on Sony VGN-Z540N */
483 		.ident = "Sony VGN-Z540N",
486 			DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
507 	 * runtime services are enabled, force EFI reboot.  in reboot_init()
576  * the following on reboot:
578  * 1) If the FADT has the ACPI reboot register flag set, try it
580  * 3) If still alive, write to the ACPI reboot register again
582  * 5) If still alive, call the EFI runtime service to reboot
583  * 6) If no EFI runtime service, call the BIOS to do a reboot
586  * two other reboot methods: 'triple fault' and 'PCI', which
587  * can be triggered via the reboot= kernel boot option or
598 	unsigned short mode;  in native_machine_emergency_restart()  local
605 	/* Tell the BIOS if we want cold or warm reboot */  in native_machine_emergency_restart()
606 	mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;  in native_machine_emergency_restart()
607 	*((unsigned short *)__va(0x472)) = mode;  in native_machine_emergency_restart()
611 	 * override the reboot= parameter.  in native_machine_emergency_restart()
614 		pr_info("EFI capsule is pending, forcing EFI reboot.\n");  in native_machine_emergency_restart()
704 	 * not receive the per-cpu timer interrupt which may trigger  in native_machine_shutdown()
804 int crashing_cpu = -1;
843  * or emergency reboot time. The function passed as parameter
856 	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);  in nmi_shootdown_cpus()
875 		msecs--;  in nmi_shootdown_cpus()