s390/dasd: enhance CUIR scope detection

This patch adds an enhanced detection for control unit initiated
reconfiguration request scope.
The first approach assumed the scope of the reconfiguration request
to be restricted to the path on which the message was received.
The enhanced approach determines the full scope of the reconfiguration
request by evaluating additional path and device selection information
contained in the reconfiguration message.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/block/dasd_eckd.h

@@ -355,7 +355,8 @@ struct dasd_gneq {
 		__u8 identifier:2;
 		__u8 reserved:6;
 	} __attribute__ ((packed)) flags;
-	__u8 reserved[5];
+	__u8 record_selector;
+	__u8 reserved[4];
 	struct {
 		__u8 value:2;
 		__u8 number:6;
@@ -492,10 +493,18 @@ struct alias_pav_group {
 	struct dasd_device *next;
 };
 
+struct dasd_conf_data {
+	struct dasd_ned neds[5];
+	u8 reserved[64];
+	struct dasd_gneq gneq;
+} __packed;
+
 struct dasd_eckd_private {
 	struct dasd_eckd_characteristics rdc_data;
 	u8 *conf_data;
 	int conf_len;
+	/* per path configuration data */
+	struct dasd_conf_data *path_conf_data[8];
 	/* pointers to specific parts in the conf_data */
 	struct dasd_ned *ned;
 	struct dasd_sneq *sneq;