lpfc: add nvmet discovery_event op support

This patch adds support for the nvmet discovery op. When the callback
routine is called, the driver will call the routine to generate an RSCN
to the port on the other end of the link.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/lpfc/lpfc_nvmet.c

@@ -1139,13 +1139,30 @@ lpfc_nvmet_defer_rcv(struct nvmet_fc_target_port *tgtport,
 	spin_unlock_irqrestore(&ctxp->ctxlock, iflag);
 }
 
+static void
+lpfc_nvmet_discovery_event(struct nvmet_fc_target_port *tgtport)
+{
+	struct lpfc_nvmet_tgtport *tgtp;
+	struct lpfc_hba *phba;
+	uint32_t rc;
+
+	tgtp = tgtport->private;
+	phba = tgtp->phba;
+
+	rc = lpfc_issue_els_rscn(phba->pport, 0);
+	lpfc_printf_log(phba, KERN_ERR, LOG_NVME,
+			"6420 NVMET subsystem change: Notification %s\n",
+			(rc) ? "Failed" : "Sent");
+}
+
 static struct nvmet_fc_target_template lpfc_tgttemplate = {
 	.targetport_delete = lpfc_nvmet_targetport_delete,
 	.xmt_ls_rsp     = lpfc_nvmet_xmt_ls_rsp,
 	.fcp_op         = lpfc_nvmet_xmt_fcp_op,
 	.fcp_abort      = lpfc_nvmet_xmt_fcp_abort,
 	.fcp_req_release = lpfc_nvmet_xmt_fcp_release,
 	.defer_rcv	= lpfc_nvmet_defer_rcv,
+	.discovery_event = lpfc_nvmet_discovery_event,
 
 	.max_hw_queues  = 1,
 	.max_sgl_segments = LPFC_NVMET_DEFAULT_SEGS,