x86: EFI runtime service support: EFI runtime services

This patch adds support for several EFI runtime services for EFI x86_64
system.

The EFI support for emergency_restart is added.
Signed-off-by: Chandramouli Narayanan <mouli@linux.intel.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/reboot_64.c

@@ -9,6 +9,7 @@
 #include <linux/pm.h>
 #include <linux/kdebug.h>
 #include <linux/sched.h>
+#include <linux/efi.h>
 #include <acpi/reboot.h>
 #include <asm/io.h>
 #include <asm/delay.h>
@@ -28,20 +29,17 @@ void (*pm_power_off)(void);
 EXPORT_SYMBOL(pm_power_off);
 
 static long no_idt[3];
-static enum { 
-	BOOT_TRIPLE = 't',
-	BOOT_KBD = 'k',
-	BOOT_ACPI = 'a'
-} reboot_type = BOOT_KBD;
+enum reboot_type reboot_type = BOOT_KBD;
 static int reboot_mode = 0;
 int reboot_force;
 
-/* reboot=t[riple] | k[bd] [, [w]arm | [c]old]
+/* reboot=t[riple] | k[bd] | e[fi] [, [w]arm | [c]old]
    warm   Don't set the cold reboot flag
    cold   Set the cold reboot flag
    triple Force a triple fault (init)
    kbd    Use the keyboard controller. cold reset (default)
    acpi   Use the RESET_REG in the FADT
+   efi    Use efi reset_system runtime service
    force  Avoid anything that could hang.
  */ 
 static int __init reboot_setup(char *str)
@@ -60,6 +58,7 @@ static int __init reboot_setup(char *str)
 		case 'a':
 		case 'b':
 		case 'k':
+		case 'e':
 			reboot_type = *str;
 			break;
 		case 'f':
@@ -155,6 +154,13 @@ void machine_emergency_restart(void)
 			acpi_reboot();
 			reboot_type = BOOT_KBD;
 			break;
+
+		case BOOT_EFI:
+			if (efi_enabled)
+				efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
+						 EFI_SUCCESS, 0, NULL);
+			reboot_type = BOOT_KBD;
+			break;
 		}
 	}      
 }

include/asm-x86/emergency-restart.h

 #ifndef _ASM_EMERGENCY_RESTART_H
 #define _ASM_EMERGENCY_RESTART_H
 
+enum reboot_type {
+	BOOT_TRIPLE = 't',
+	BOOT_KBD = 'k',
+	BOOT_ACPI = 'a',
+	BOOT_EFI = 'e'
+};
+
+extern enum reboot_type reboot_type;
+
 extern void machine_emergency_restart(void);
 
 #endif /* _ASM_EMERGENCY_RESTART_H */