[S390] dasd: re-initialize read_conf buffer for retries

The buffer for read configuration data has to be initialized with an
EBCDIC string to show support for extended UIDs to z/VM.
If this read configuration data CQR needs to be retried, the buffer
may have changed in between. So re-initialize the buffer to get a
correct extended UID under z/VM.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/block/dasd.c

@@ -2059,13 +2059,14 @@ void dasd_add_request_tail(struct dasd_ccw_req *cqr)
 /*
  * Wakeup helper for the 'sleep_on' functions.
  */
-static void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
+void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
 {
 	spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
 	cqr->callback_data = DASD_SLEEPON_END_TAG;
 	spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
 	wake_up(&generic_waitq);
 }
+EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
 
 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
 {
@@ -2165,7 +2166,9 @@ static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
 		} else
 			wait_event(generic_waitq, !(device->stopped));
 
-		cqr->callback = dasd_wakeup_cb;
+		if (!cqr->callback)
+			cqr->callback = dasd_wakeup_cb;
+
 		cqr->callback_data = DASD_SLEEPON_START_TAG;
 		dasd_add_request_tail(cqr);
 		if (interruptible) {

drivers/s390/block/dasd_eckd.c

@@ -844,6 +844,30 @@ static void dasd_eckd_fill_rcd_cqr(struct dasd_device *device,
 	set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);
 }
 
+/*
+ * Wakeup helper for read_conf
+ * if the cqr is not done and needs some error recovery
+ * the buffer has to be re-initialized with the EBCDIC "V1.0"
+ * to show support for virtual device SNEQ
+ */
+static void read_conf_cb(struct dasd_ccw_req *cqr, void *data)
+{
+	struct ccw1 *ccw;
+	__u8 *rcd_buffer;
+
+	if (cqr->status !=  DASD_CQR_DONE) {
+		ccw = cqr->cpaddr;
+		rcd_buffer = (__u8 *)((addr_t) ccw->cda);
+		memset(rcd_buffer, 0, sizeof(*rcd_buffer));
+
+		rcd_buffer[0] = 0xE5;
+		rcd_buffer[1] = 0xF1;
+		rcd_buffer[2] = 0x4B;
+		rcd_buffer[3] = 0xF0;
+	}
+	dasd_wakeup_cb(cqr, data);
+}
+
 static int dasd_eckd_read_conf_immediately(struct dasd_device *device,
 					   struct dasd_ccw_req *cqr,
 					   __u8 *rcd_buffer,
@@ -863,6 +887,7 @@ static int dasd_eckd_read_conf_immediately(struct dasd_device *device,
 	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 	set_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags);
 	cqr->retries = 5;
+	cqr->callback = read_conf_cb;
 	rc = dasd_sleep_on_immediatly(cqr);
 	return rc;
 }
@@ -900,6 +925,7 @@ static int dasd_eckd_read_conf_lpm(struct dasd_device *device,
 		goto out_error;
 	}
 	dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buf, lpm);
+	cqr->callback = read_conf_cb;
 	ret = dasd_sleep_on(cqr);
 	/*
 	 * on success we update the user input parms

drivers/s390/block/dasd_int.h

@@ -643,6 +643,7 @@ struct dasd_ccw_req *
 dasd_smalloc_request(int , int, int, struct dasd_device *);
 void dasd_kfree_request(struct dasd_ccw_req *, struct dasd_device *);
 void dasd_sfree_request(struct dasd_ccw_req *, struct dasd_device *);
+void dasd_wakeup_cb(struct dasd_ccw_req *, void *);
 
 static inline int
 dasd_kmalloc_set_cda(struct ccw1 *ccw, void *cda, struct dasd_device *device)