s390/head64: Make startup code ready for lowcore relocation

In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in startup_continue().

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

Author: svens-s390

arch/s390/kernel/head64.S

@@ -10,6 +10,7 @@
 
 #include <linux/init.h>
 #include <linux/linkage.h>
+#include <asm/lowcore.h>
 #include <asm/asm-offsets.h>
 #include <asm/thread_info.h>
 #include <asm/page.h>
@@ -18,14 +19,15 @@
 __HEAD
 SYM_CODE_START(startup_continue)
 	larl	%r1,tod_clock_base
-	mvc	0(16,%r1),__LC_BOOT_CLOCK
+	GET_LC	%r2
+	mvc	0(16,%r1),__LC_BOOT_CLOCK(%r2)
 #
 # Setup stack
 #
 	larl	%r14,init_task
-	stg	%r14,__LC_CURRENT
+	stg	%r14,__LC_CURRENT(%r2)
 	larl	%r15,init_thread_union+STACK_INIT_OFFSET
-	stg	%r15,__LC_KERNEL_STACK
+	stg	%r15,__LC_KERNEL_STACK(%r2)
 	brasl	%r14,sclp_early_adjust_va	# allow sclp_early_printk
 	brasl	%r14,startup_init		# s390 specific early init
 	brasl	%r14,start_kernel		# common init code