[S390] cio: CHSC SIOSL Support

A Linux interface for the CHSC command
store-I/O-operation-status-and-initiate-logging (SIOSL).
Model-dependent logging within the channel subsystem can be invoked
via a helper function or a writable subchannel device attribute.

Signed-off-by: Michael Ernst <mernst@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/ccwdev.h b/arch/s390/include/asm/ccwdev.h
index 1c0030f..f3ba0fa 100644
--- a/arch/s390/include/asm/ccwdev.h
+++ b/arch/s390/include/asm/ccwdev.h
@@ -208,6 +208,8 @@
 extern struct ccw_device *ccw_device_probe_console(void);
 extern int ccw_device_force_console(void);
 
+int ccw_device_siosl(struct ccw_device *);
+
 // FIXME: these have to go
 extern int _ccw_device_get_subchannel_number(struct ccw_device *);