scsi: ibmvfc: Simplify handling of sub-CRQ initialization

If ibmvfc_init_sub_crqs() fails ibmvfc_probe() simply parrots registration
failure reported elsewhere, and futher vhost->scsi_scrq.scrq == NULL is
indication enough to the driver that it has no sub-CRQs available. The
mq_enabled check can also be moved into ibmvfc_init_sub_crqs() such that
each caller doesn't have to gate the call with a mq_enabled check. Finally,
in the case of sub-CRQ setup failure setting do_enquiry can be turned off
to putting the driver into single queue fallback mode.

The aforementioned changes also simplify the next patch in the series that
fixes a hard reset issue, by tying a sub-CRQ setup failure and do_enquiry
logic into ibmvfc_init_sub_crqs().

Link: https://lore.kernel.org/r/20210302230543.9905-2-tyreld@linux.ibm.comReviewed-by: Brian King <brking@linux.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ibmvscsi/ibmvfc.c

@@ -5707,17 +5707,21 @@ static void ibmvfc_deregister_scsi_channel(struct ibmvfc_host *vhost, int index)
 	LEAVE;
 }
 
-static int ibmvfc_init_sub_crqs(struct ibmvfc_host *vhost)
+static void ibmvfc_init_sub_crqs(struct ibmvfc_host *vhost)
 {
 	int i, j;
 
 	ENTER;
+	if (!vhost->mq_enabled)
+		return;
 
 	vhost->scsi_scrqs.scrqs = kcalloc(nr_scsi_hw_queues,
 					  sizeof(*vhost->scsi_scrqs.scrqs),
 					  GFP_KERNEL);
-	if (!vhost->scsi_scrqs.scrqs)
-		return -1;
+	if (!vhost->scsi_scrqs.scrqs) {
+		vhost->do_enquiry = 0;
+		return;
+	}
 
 	for (i = 0; i < nr_scsi_hw_queues; i++) {
 		if (ibmvfc_register_scsi_channel(vhost, i)) {
@@ -5726,13 +5730,12 @@ static int ibmvfc_init_sub_crqs(struct ibmvfc_host *vhost)
 			kfree(vhost->scsi_scrqs.scrqs);
 			vhost->scsi_scrqs.scrqs = NULL;
 			vhost->scsi_scrqs.active_queues = 0;
-			LEAVE;
-			return -1;
+			vhost->do_enquiry = 0;
+			break;
 		}
 	}
 
 	LEAVE;
-	return 0;
 }
 
 static void ibmvfc_release_sub_crqs(struct ibmvfc_host *vhost)
@@ -5999,11 +6002,7 @@ static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 		goto remove_shost;
 	}
 
-	if (vhost->mq_enabled) {
-		rc = ibmvfc_init_sub_crqs(vhost);
-		if (rc)
-			dev_warn(dev, "Failed to allocate Sub-CRQs. rc=%d\n", rc);
-	}
+	ibmvfc_init_sub_crqs(vhost);
 
 	if (shost_to_fc_host(shost)->rqst_q)
 		blk_queue_max_segments(shost_to_fc_host(shost)->rqst_q, 1);