[S390] smp: always reboot on cpu 0

Always reboot on logical cpu 0. This makes sure that the IPL cpu is
always the same and usually avoids strange numbering schemes between
physical and logical cpus.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index 9d2acb0..c2d0e63 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -31,6 +31,18 @@
 
 extern struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
 
+extern void smp_switch_to_ipl_cpu(void (*func)(void *), void *);
+extern void smp_switch_to_cpu(void (*)(void *), void *, unsigned long sp,
+			      int from, int to);
+extern void smp_restart_cpu(void);
+
+#else /* CONFIG_SMP */
+
+static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
+{
+	func(data);
+}
+
 #endif /* CONFIG_SMP */
 
 #ifdef CONFIG_HOTPLUG_CPU