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Commit fa20efd2 authored by Aaron Durbin's avatar Aaron Durbin Committed by Ingo Molnar
Browse files

x86: add ACPI reboot option 



Add the ability to reboot an x86_64 based machine using the RESET_REG in the
FADT ACPI table.

Signed-off-by: default avatarAaron Durbin <adurbin@google.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 5f561d3b

Documentation/x86_64/boot-options.txt

+4 −1
Original line number Original line Diff line number Diff line
@@ -110,12 +110,15 @@ Idle loop 




Rebooting

Rebooting





   reboot=b[ios] | t[riple] | k[bd] [, [w]arm | [c]old]

   reboot=b[ios] | t[riple] | k[bd] | a[cpi] [, [w]arm | [c]old]

   bios	  Use the CPU reboot vector for warm reset

   bios	  Use the CPU reboot vector for warm reset

   warm   Don't set the cold reboot flag

   warm   Don't set the cold reboot flag

   cold   Set the cold reboot flag

   cold   Set the cold reboot flag

   triple Force a triple fault (init)

   triple Force a triple fault (init)

   kbd    Use the keyboard controller. cold reset (default)

   kbd    Use the keyboard controller. cold reset (default)

   acpi   Use the ACPI RESET_REG in the FADT. If ACPI is not configured or the

          ACPI reset does not work, the reboot path attempts the reset using

          the keyboard controller.





   Using warm reset will be much faster especially on big memory

   Using warm reset will be much faster especially on big memory

   systems because the BIOS will not go through the memory check.

   systems because the BIOS will not go through the memory check.

arch/x86/kernel/reboot_64.c

+10 −1
Original line number Original line Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/pm.h>

#include <linux/pm.h>

#include <linux/kdebug.h>

#include <linux/kdebug.h>

#include <linux/sched.h>

#include <linux/sched.h>

#include <acpi/reboot.h>

#include <asm/io.h>

#include <asm/io.h>

#include <asm/delay.h>

#include <asm/delay.h>

#include <asm/desc.h>

#include <asm/desc.h>
@@ -29,7 +30,8 @@ EXPORT_SYMBOL(pm_power_off); 
static long no_idt[3];

static long no_idt[3];

static enum { 

static enum { 

	BOOT_TRIPLE = 't',

	BOOT_TRIPLE = 't',

	BOOT_KBD = 'k'

	BOOT_KBD = 'k',

	BOOT_ACPI = 'a'

} reboot_type = BOOT_KBD;

} reboot_type = BOOT_KBD;

static int reboot_mode = 0;

static int reboot_mode = 0;

int reboot_force;

int reboot_force;
@@ -39,6 +41,7 @@ int reboot_force; 
   cold   Set the cold reboot flag

   cold   Set the cold reboot flag

   triple Force a triple fault (init)

   triple Force a triple fault (init)

   kbd    Use the keyboard controller. cold reset (default)

   kbd    Use the keyboard controller. cold reset (default)

   acpi   Use the RESET_REG in the FADT

   force  Avoid anything that could hang.

   force  Avoid anything that could hang.

 */ 

 */ 

static int __init reboot_setup(char *str)

static int __init reboot_setup(char *str)
@@ -54,6 +57,7 @@ static int __init reboot_setup(char *str) 
			break;

			break;





		case 't':

		case 't':

		case 'a':

		case 'b':

		case 'b':

		case 'k':

		case 'k':

			reboot_type = *str;

			reboot_type = *str;
@@ -146,6 +150,11 @@ void machine_emergency_restart(void) 




			reboot_type = BOOT_KBD;

			reboot_type = BOOT_KBD;

			break;

			break;



		case BOOT_ACPI:

			acpi_reboot();

			reboot_type = BOOT_KBD;

			break;

		}      

		}      

	}      

	}      

}

}