[S390] cio: Introduce subchannel->private.

Introduce a private pointer in struct subchannel to store
per-subchannel type data (cannot use dev->priv since this
is already used for something else).

Create a new header io_sch.h for I/O subchannel specific structures
and instructions.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/device_id.c b/drivers/s390/cio/device_id.c
index 156f3f9..918b8b8 100644
--- a/drivers/s390/cio/device_id.c
+++ b/drivers/s390/cio/device_id.c
@@ -24,6 +24,7 @@
 #include "css.h"
 #include "device.h"
 #include "ioasm.h"
+#include "io_sch.h"
 
 /*
  * Input :
@@ -219,11 +220,13 @@
 		return -EAGAIN;
 	}
 	if (irb->scsw.cc == 3) {
-		if ((sch->orb.lpm &
-		     sch->schib.pmcw.pim & sch->schib.pmcw.pam) != 0)
+		u8 lpm;
+
+		lpm = to_io_private(sch)->orb.lpm;
+		if ((lpm & sch->schib.pmcw.pim & sch->schib.pmcw.pam) != 0)
 			CIO_MSG_EVENT(2, "SenseID : path %02X for device %04x "
 				      "on subchannel 0.%x.%04x is "
-				      "'not operational'\n", sch->orb.lpm,
+				      "'not operational'\n", lpm,
 				      cdev->private->dev_id.devno,
 				      sch->schid.ssid, sch->schid.sch_no);
 		return -EACCES;