[S390] cio: introduce fcx enabled scsw format

Extend the scsw data structure to the format required by fcx. Also
provide helper functions for easier access to fields which are present
in both the traditional as well as the modified format.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index efdb9fd..f7a0cb9 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -48,7 +48,7 @@
  */
 struct schib {
 	struct pmcw pmcw;	 /* path management control word */
-	struct scsw scsw;	 /* subchannel status word */
+	union scsw scsw;	 /* subchannel status word */
 	__u64 mba;               /* measurement block address */
 	__u8 mda[4];		 /* model dependent area */
 } __attribute__ ((packed,aligned(4)));