lpfc: add support for translating an RSCN rcv into a discovery rescan

This patch updates RSCN receive processing to check for the remote
port being an NVME port, and if so, invoke the nvme_fc callback to
rescan the remote port.  The rescan will generate a discovery udev
event.
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_crtn.h

@@ -557,6 +557,8 @@ void lpfc_ras_stop_fwlog(struct lpfc_hba *phba);
 int lpfc_check_fwlog_support(struct lpfc_hba *phba);
 
 /* NVME interfaces. */
+void lpfc_nvme_rescan_port(struct lpfc_vport *vport,
+			   struct lpfc_nodelist *ndlp);
 void lpfc_nvme_unregister_port(struct lpfc_vport *vport,
 			struct lpfc_nodelist *ndlp);
 int lpfc_nvme_register_port(struct lpfc_vport *vport,

drivers/scsi/lpfc/lpfc_els.c

@@ -6326,6 +6326,8 @@ lpfc_rscn_recovery_check(struct lpfc_vport *vport)
 			continue;
 		}
 
+		if (ndlp->nlp_fc4_type & NLP_FC4_NVME)
+			lpfc_nvme_rescan_port(vport, ndlp);
 
 		lpfc_disc_state_machine(vport, ndlp, NULL,
 					NLP_EVT_DEVICE_RECOVERY);
@@ -6437,6 +6439,9 @@ lpfc_els_rcv_rscn(struct lpfc_vport *vport, struct lpfc_iocbq *cmdiocb,
 				 "2024 pt2pt RSCN %08x Data: x%x x%x\n",
 				 *lp, vport->fc_flag, payload_len);
 		lpfc_els_rsp_acc(vport, ELS_CMD_ACC, cmdiocb, ndlp, NULL);
+
+		if (ndlp->nlp_fc4_type & NLP_FC4_NVME)
+			lpfc_nvme_rescan_port(vport, ndlp);
 		return 0;
 	}
 

drivers/scsi/lpfc/lpfc_nvme.c

@@ -2402,6 +2402,50 @@ lpfc_nvme_register_port(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
 #endif
 }
 
+/**
+ * lpfc_nvme_rescan_port - Check to see if we should rescan this remoteport
+ *
+ * If the ndlp represents an NVME Target, that we are logged into,
+ * ping the NVME FC Transport layer to initiate a device rescan
+ * on this remote NPort.
+ */
+void
+lpfc_nvme_rescan_port(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
+{
+#if (IS_ENABLED(CONFIG_NVME_FC))
+	struct lpfc_nvme_rport *rport;
+	struct nvme_fc_remote_port *remoteport;
+
+	rport = ndlp->nrport;
+
+	lpfc_printf_vlog(vport, KERN_INFO, LOG_NVME_DISC,
+			 "6170 Rescan NPort DID x%06x type x%x "
+			 "state x%x rport %p\n",
+			 ndlp->nlp_DID, ndlp->nlp_type, ndlp->nlp_state, rport);
+	if (!rport)
+		goto input_err;
+	remoteport = rport->remoteport;
+	if (!remoteport)
+		goto input_err;
+
+	/* Only rescan if we are an NVME target in the MAPPED state */
+	if (remoteport->port_role & FC_PORT_ROLE_NVME_DISCOVERY &&
+	    ndlp->nlp_state == NLP_STE_MAPPED_NODE) {
+		nvme_fc_rescan_remoteport(remoteport);
+
+		lpfc_printf_vlog(vport, KERN_ERR, LOG_NVME_DISC,
+				 "6172 NVME rescanned DID x%06x "
+				 "port_state x%x\n",
+				 ndlp->nlp_DID, remoteport->port_state);
+	}
+	return;
+input_err:
+	lpfc_printf_vlog(vport, KERN_ERR, LOG_NVME_DISC,
+			 "6169 State error: lport %p, rport%p FCID x%06x\n",
+			 vport->localport, ndlp->rport, ndlp->nlp_DID);
+#endif
+}
+
 /* lpfc_nvme_unregister_port - unbind the DID and port_role from this rport.
  *
  * There is no notion of Devloss or rport recovery from the current