scsi: always assign block layer tags if enabled

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq.  This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index 4a15006..a24106a 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -5598,10 +5598,7 @@
 	struct lpfc_vport *vport = (struct lpfc_vport *) sdev->host->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	if (sdev->tagged_supported)
-		scsi_activate_tcq(sdev, vport->cfg_lun_queue_depth);
-	else
-		scsi_deactivate_tcq(sdev, vport->cfg_lun_queue_depth);
+	scsi_adjust_queue_depth(sdev, 0, vport->cfg_lun_queue_depth);
 
 	if (phba->cfg_poll & ENABLE_FCP_RING_POLLING) {
 		lpfc_sli_handle_fast_ring_event(phba,
@@ -5986,6 +5983,7 @@
 	.vendor_id		= LPFC_NL_VENDOR_ID,
 	.change_queue_depth	= lpfc_change_queue_depth,
 	.change_queue_type	= scsi_change_queue_type,
+	.use_blk_tags		= 1,
 };
 
 struct scsi_host_template lpfc_vport_template = {
@@ -6009,4 +6007,5 @@
 	.max_sectors		= 0xFFFF,
 	.change_queue_depth	= lpfc_change_queue_depth,
 	.change_queue_type	= scsi_change_queue_type,
+	.use_blk_tags		= 1,
 };