x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64

With the revamped realmode trampoline code, it is trivial to extend
support for reboot=bios to x86-64.  Furthermore, while we are at it,
remove the restriction that only we can only override the reboot CPU
on 32 bits.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org

3 files changed, 4 insertions, 5 deletions

diff --git a/arch/x86/include/asm/emergency-restart.h b/arch/x86/include/asm/emergency-restart.h
index cc70c1c78ca4..75ce3f47d204 100644
--- a/arch/x86/include/asm/emergency-restart.h
+++ b/arch/x86/include/asm/emergency-restart.h
@@ -4,9 +4,7 @@
 enum reboot_type {
         BOOT_TRIPLE = 't',
         BOOT_KBD = 'k',
-#ifdef CONFIG_X86_32
         BOOT_BIOS = 'b',
-#endif
         BOOT_ACPI = 'a',
         BOOT_EFI = 'e',
         BOOT_CF9 = 'p',
diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h
index fce3f4ae5bd6..fe1ec5bcd846 100644
--- a/arch/x86/include/asm/realmode.h
+++ b/arch/x86/include/asm/realmode.h
@@ -21,8 +21,9 @@ struct real_mode_header {
         u32     wakeup_header;
 #endif
         /* APM/BIOS reboot */
-#ifdef CONFIG_X86_32
         u32     machine_real_restart_asm;
+#ifdef CONFIG_X86_64
+        u32     machine_real_restart_seg;
 #endif
 };
 
diff --git a/arch/x86/include/asm/reboot.h b/arch/x86/include/asm/reboot.h
index 92f297069e87..a82c4f1b4d83 100644
--- a/arch/x86/include/asm/reboot.h
+++ b/arch/x86/include/asm/reboot.h
@@ -18,8 +18,8 @@ extern struct machine_ops machine_ops;
 
 void native_machine_crash_shutdown(struct pt_regs *regs);
 void native_machine_shutdown(void);
-void machine_real_restart(unsigned int type);
-/* These must match dispatch_table in reboot_32.S */
+void __noreturn machine_real_restart(unsigned int type);
+/* These must match dispatch in arch/x86/realmore/rm/reboot.S */
 #define MRR_BIOS        0
 #define MRR_APM         1