[S390] cio: Export chsc_error_from_response().

Make chsc_error_from_response() available to chsc callers outside
of chsc.c (namely qdio) to avoid duplicating error checking code.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

drivers/s390/cio/chsc.c

@@ -27,7 +27,13 @@
 
 static void *sei_page;
 
-static int chsc_error_from_response(int response)
+/**
+ * chsc_error_from_response() - convert a chsc response to an error
+ * @response: chsc response code
+ *
+ * Returns an appropriate Linux error code for @response.
+ */
+int chsc_error_from_response(int response)
 {
 	switch (response) {
 	case 0x0001:
@@ -45,6 +51,7 @@ static int chsc_error_from_response(int response)
 		return -EIO;
 	}
 }
+EXPORT_SYMBOL_GPL(chsc_error_from_response);
 
 struct chsc_ssd_area {
 	struct chsc_header request;

drivers/s390/cio/chsc.h

@@ -101,4 +101,6 @@ void chsc_chp_online(struct chp_id chpid);
 void chsc_chp_offline(struct chp_id chpid);
 int chsc_get_channel_measurement_chars(struct channel_path *chp);
 
+int chsc_error_from_response(int response);
+
 #endif