scsi: lpfc: Implement GID_PT on Nameserver query to support faster failover

The switches seem to respond faster to GID_PT vs GID_FT NameServer
queries.  Add support for GID_PT to be used over GID_FT to enable
faster storage failover detection. Includes addition of new module
parameter to select between GID_PT and GID_FT (GID_FT is default).

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc.h

@@ -784,6 +784,7 @@ struct lpfc_hba {
 #define LPFC_FCF_PRIORITY 2	/* Priority fcf failover */
 	uint32_t cfg_fcf_failover_policy;
 	uint32_t cfg_fcp_io_sched;
+	uint32_t cfg_ns_query;
 	uint32_t cfg_fcp2_no_tgt_reset;
 	uint32_t cfg_cr_delay;
 	uint32_t cfg_cr_count;

drivers/scsi/lpfc/lpfc_attr.c

@@ -5069,6 +5069,18 @@ LPFC_ATTR_RW(fcp_io_sched, LPFC_FCP_SCHED_ROUND_ROBIN,
 	     "Determine scheduling algorithm for "
 	     "issuing commands [0] - Round Robin, [1] - Current CPU");
 
+/*
+ * lpfc_ns_query: Determine algrithmn for NameServer queries after RSCN
+ * range is [0,1]. Default value is 0.
+ * For [0], GID_FT is used for NameServer queries after RSCN (default)
+ * For [1], GID_PT is used for NameServer queries after RSCN
+ *
+ */
+LPFC_ATTR_RW(ns_query, LPFC_NS_QUERY_GID_FT,
+	     LPFC_NS_QUERY_GID_FT, LPFC_NS_QUERY_GID_PT,
+	     "Determine algorithm NameServer queries after RSCN "
+	     "[0] - GID_FT, [1] - GID_PT");
+
 /*
 # lpfc_fcp2_no_tgt_reset: Determine bus reset behavior
 # range is [0,1]. Default value is 0.
@@ -5514,6 +5526,7 @@ struct device_attribute *lpfc_hba_attrs[] = {
 	&dev_attr_lpfc_scan_down,
 	&dev_attr_lpfc_link_speed,
 	&dev_attr_lpfc_fcp_io_sched,
+	&dev_attr_lpfc_ns_query,
 	&dev_attr_lpfc_fcp2_no_tgt_reset,
 	&dev_attr_lpfc_cr_delay,
 	&dev_attr_lpfc_cr_count,
@@ -6564,6 +6577,7 @@ void
 lpfc_get_cfgparam(struct lpfc_hba *phba)
 {
 	lpfc_fcp_io_sched_init(phba, lpfc_fcp_io_sched);
+	lpfc_ns_query_init(phba, lpfc_ns_query);
 	lpfc_fcp2_no_tgt_reset_init(phba, lpfc_fcp2_no_tgt_reset);
 	lpfc_cr_delay_init(phba, lpfc_cr_delay);
 	lpfc_cr_count_init(phba, lpfc_cr_count);

drivers/scsi/lpfc/lpfc_crtn.h

@@ -175,6 +175,7 @@ void lpfc_hb_timeout_handler(struct lpfc_hba *);
 void lpfc_ct_unsol_event(struct lpfc_hba *, struct lpfc_sli_ring *,
 			 struct lpfc_iocbq *);
 int lpfc_ct_handle_unsol_abort(struct lpfc_hba *, struct hbq_dmabuf *);
+int lpfc_issue_gidpt(struct lpfc_vport *vport);
 int lpfc_issue_gidft(struct lpfc_vport *vport);
 int lpfc_get_gidft_type(struct lpfc_vport *vport, struct lpfc_iocbq *iocbq);
 int lpfc_ns_cmd(struct lpfc_vport *, int, uint8_t, uint32_t);

drivers/scsi/lpfc/lpfc_ct.c

@@ -831,6 +831,198 @@ lpfc_cmpl_ct_cmd_gid_ft(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 	return;
 }
 
+static void
+lpfc_cmpl_ct_cmd_gid_pt(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
+			struct lpfc_iocbq *rspiocb)
+{
+	struct lpfc_vport *vport = cmdiocb->vport;
+	struct Scsi_Host *shost = lpfc_shost_from_vport(vport);
+	IOCB_t *irsp;
+	struct lpfc_dmabuf *outp;
+	struct lpfc_dmabuf *inp;
+	struct lpfc_sli_ct_request *CTrsp;
+	struct lpfc_sli_ct_request *CTreq;
+	struct lpfc_nodelist *ndlp;
+	int rc;
+
+	/* First save ndlp, before we overwrite it */
+	ndlp = cmdiocb->context_un.ndlp;
+
+	/* we pass cmdiocb to state machine which needs rspiocb as well */
+	cmdiocb->context_un.rsp_iocb = rspiocb;
+	inp = (struct lpfc_dmabuf *)cmdiocb->context1;
+	outp = (struct lpfc_dmabuf *)cmdiocb->context2;
+	irsp = &rspiocb->iocb;
+
+	lpfc_debugfs_disc_trc(vport, LPFC_DISC_TRC_CT,
+			      "GID_PT cmpl:     status:x%x/x%x rtry:%d",
+			      irsp->ulpStatus, irsp->un.ulpWord[4],
+			      vport->fc_ns_retry);
+
+	/* Don't bother processing response if vport is being torn down. */
+	if (vport->load_flag & FC_UNLOADING) {
+		if (vport->fc_flag & FC_RSCN_MODE)
+			lpfc_els_flush_rscn(vport);
+		goto out;
+	}
+
+	if (lpfc_els_chk_latt(vport)) {
+		lpfc_printf_vlog(vport, KERN_INFO, LOG_DISCOVERY,
+				 "4108 Link event during NS query\n");
+		if (vport->fc_flag & FC_RSCN_MODE)
+			lpfc_els_flush_rscn(vport);
+		lpfc_vport_set_state(vport, FC_VPORT_FAILED);
+		goto out;
+	}
+	if (lpfc_error_lost_link(irsp)) {
+		lpfc_printf_vlog(vport, KERN_INFO, LOG_DISCOVERY,
+				 "4101 NS query failed due to link event\n");
+		if (vport->fc_flag & FC_RSCN_MODE)
+			lpfc_els_flush_rscn(vport);
+		goto out;
+	}
+
+	spin_lock_irq(shost->host_lock);
+	if (vport->fc_flag & FC_RSCN_DEFERRED) {
+		vport->fc_flag &= ~FC_RSCN_DEFERRED;
+		spin_unlock_irq(shost->host_lock);
+
+		/* This is a GID_PT completing so the gidft_inp counter was
+		 * incremented before the GID_PT was issued to the wire.
+		 */
+		vport->gidft_inp--;
+
+		/*
+		 * Skip processing the NS response
+		 * Re-issue the NS cmd
+		 */
+		lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
+				 "4102 Process Deferred RSCN Data: x%x x%x\n",
+				 vport->fc_flag, vport->fc_rscn_id_cnt);
+		lpfc_els_handle_rscn(vport);
+
+		goto out;
+	}
+	spin_unlock_irq(shost->host_lock);
+
+	if (irsp->ulpStatus) {
+		/* Check for retry */
+		if (vport->fc_ns_retry < LPFC_MAX_NS_RETRY) {
+			if (irsp->ulpStatus != IOSTAT_LOCAL_REJECT ||
+			    (irsp->un.ulpWord[4] & IOERR_PARAM_MASK) !=
+			    IOERR_NO_RESOURCES)
+				vport->fc_ns_retry++;
+
+			/* CT command is being retried */
+			vport->gidft_inp--;
+			rc = lpfc_ns_cmd(vport, SLI_CTNS_GID_PT,
+					 vport->fc_ns_retry, GID_PT_N_PORT);
+			if (rc == 0)
+				goto out;
+		}
+		if (vport->fc_flag & FC_RSCN_MODE)
+			lpfc_els_flush_rscn(vport);
+		lpfc_vport_set_state(vport, FC_VPORT_FAILED);
+		lpfc_printf_vlog(vport, KERN_ERR, LOG_ELS,
+				 "4103 GID_FT Query error: 0x%x 0x%x\n",
+				 irsp->ulpStatus, vport->fc_ns_retry);
+	} else {
+		/* Good status, continue checking */
+		CTreq = (struct lpfc_sli_ct_request *)inp->virt;
+		CTrsp = (struct lpfc_sli_ct_request *)outp->virt;
+		if (CTrsp->CommandResponse.bits.CmdRsp ==
+		    cpu_to_be16(SLI_CT_RESPONSE_FS_ACC)) {
+			lpfc_printf_vlog(vport, KERN_INFO, LOG_DISCOVERY,
+					 "4105 NameServer Rsp Data: x%x x%x\n",
+					 vport->fc_flag,
+					 CTreq->un.gid.Fc4Type);
+
+			lpfc_ns_rsp(vport,
+				    outp,
+				    CTreq->un.gid.Fc4Type,
+				    (uint32_t)(irsp->un.genreq64.bdl.bdeSize));
+		} else if (CTrsp->CommandResponse.bits.CmdRsp ==
+			   be16_to_cpu(SLI_CT_RESPONSE_FS_RJT)) {
+			/* NameServer Rsp Error */
+			if ((CTrsp->ReasonCode == SLI_CT_UNABLE_TO_PERFORM_REQ)
+			    && (CTrsp->Explanation == SLI_CT_NO_FC4_TYPES)) {
+				lpfc_printf_vlog(
+					vport, KERN_INFO, LOG_DISCOVERY,
+					"4106 No NameServer Entries "
+					"Data: x%x x%x x%x x%x\n",
+					CTrsp->CommandResponse.bits.CmdRsp,
+					(uint32_t)CTrsp->ReasonCode,
+					(uint32_t)CTrsp->Explanation,
+					vport->fc_flag);
+
+				lpfc_debugfs_disc_trc(
+				vport, LPFC_DISC_TRC_CT,
+				"GID_PT no entry  cmd:x%x rsn:x%x exp:x%x",
+				(uint32_t)CTrsp->CommandResponse.bits.CmdRsp,
+				(uint32_t)CTrsp->ReasonCode,
+				(uint32_t)CTrsp->Explanation);
+			} else {
+				lpfc_printf_vlog(
+					vport, KERN_INFO, LOG_DISCOVERY,
+					"4107 NameServer Rsp Error "
+					"Data: x%x x%x x%x x%x\n",
+					CTrsp->CommandResponse.bits.CmdRsp,
+					(uint32_t)CTrsp->ReasonCode,
+					(uint32_t)CTrsp->Explanation,
+					vport->fc_flag);
+
+				lpfc_debugfs_disc_trc(
+				vport, LPFC_DISC_TRC_CT,
+				"GID_PT rsp err1  cmd:x%x rsn:x%x exp:x%x",
+				(uint32_t)CTrsp->CommandResponse.bits.CmdRsp,
+				(uint32_t)CTrsp->ReasonCode,
+				(uint32_t)CTrsp->Explanation);
+			}
+		} else {
+			/* NameServer Rsp Error */
+			lpfc_printf_vlog(vport, KERN_ERR, LOG_DISCOVERY,
+					 "4109 NameServer Rsp Error "
+					 "Data: x%x x%x x%x x%x\n",
+					 CTrsp->CommandResponse.bits.CmdRsp,
+					 (uint32_t)CTrsp->ReasonCode,
+					 (uint32_t)CTrsp->Explanation,
+					 vport->fc_flag);
+
+			lpfc_debugfs_disc_trc(
+				vport, LPFC_DISC_TRC_CT,
+				"GID_PT rsp err2  cmd:x%x rsn:x%x exp:x%x",
+				(uint32_t)CTrsp->CommandResponse.bits.CmdRsp,
+				(uint32_t)CTrsp->ReasonCode,
+				(uint32_t)CTrsp->Explanation);
+		}
+		vport->gidft_inp--;
+	}
+	/* Link up / RSCN discovery */
+	if ((vport->num_disc_nodes == 0) &&
+	    (vport->gidft_inp == 0)) {
+		/*
+		 * The driver has cycled through all Nports in the RSCN payload.
+		 * Complete the handling by cleaning up and marking the
+		 * current driver state.
+		 */
+		if (vport->port_state >= LPFC_DISC_AUTH) {
+			if (vport->fc_flag & FC_RSCN_MODE) {
+				lpfc_els_flush_rscn(vport);
+				spin_lock_irq(shost->host_lock);
+				vport->fc_flag |= FC_RSCN_MODE; /* RSCN still */
+				spin_unlock_irq(shost->host_lock);
+			} else {
+				lpfc_els_flush_rscn(vport);
+			}
+		}
+
+		lpfc_disc_start(vport);
+	}
+out:
+	cmdiocb->context_un.ndlp = ndlp; /* Now restore ndlp for free */
+	lpfc_ct_free_iocb(phba, cmdiocb);
+}
+
 static void
 lpfc_cmpl_ct_cmd_gff_id(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 			struct lpfc_iocbq *rspiocb)
@@ -1365,6 +1557,8 @@ lpfc_ns_cmd(struct lpfc_vport *vport, int cmdcode,
 	bpl->tus.f.bdeFlags = 0;
 	if (cmdcode == SLI_CTNS_GID_FT)
 		bpl->tus.f.bdeSize = GID_REQUEST_SZ;
+	else if (cmdcode == SLI_CTNS_GID_PT)
+		bpl->tus.f.bdeSize = GID_REQUEST_SZ;
 	else if (cmdcode == SLI_CTNS_GFF_ID)
 		bpl->tus.f.bdeSize = GFF_REQUEST_SZ;
 	else if (cmdcode == SLI_CTNS_GFT_ID)
@@ -1405,6 +1599,18 @@ lpfc_ns_cmd(struct lpfc_vport *vport, int cmdcode,
 		rsp_size = FC_MAX_NS_RSP;
 		break;
 
+	case SLI_CTNS_GID_PT:
+		CtReq->CommandResponse.bits.CmdRsp =
+		    cpu_to_be16(SLI_CTNS_GID_PT);
+		CtReq->un.gid.PortType = context;
+
+		if (vport->port_state < LPFC_NS_QRY)
+			vport->port_state = LPFC_NS_QRY;
+		lpfc_set_disctmo(vport);
+		cmpl = lpfc_cmpl_ct_cmd_gid_pt;
+		rsp_size = FC_MAX_NS_RSP;
+		break;
+
 	case SLI_CTNS_GFF_ID:
 		CtReq->CommandResponse.bits.CmdRsp =
 			cpu_to_be16(SLI_CTNS_GFF_ID);

drivers/scsi/lpfc/lpfc_els.c

@@ -6371,6 +6371,7 @@ int
 lpfc_els_handle_rscn(struct lpfc_vport *vport)
 {
 	struct lpfc_nodelist *ndlp;
+	struct lpfc_hba  *phba = vport->phba;
 
 	/* Ignore RSCN if the port is being torn down. */
 	if (vport->load_flag & FC_UNLOADING) {
@@ -6399,8 +6400,15 @@ lpfc_els_handle_rscn(struct lpfc_vport *vport)
 		 * flush the RSCN.  Otherwise, the outstanding requests
 		 * need to complete.
 		 */
-		if (lpfc_issue_gidft(vport) > 0)
+		if (phba->cfg_ns_query == LPFC_NS_QUERY_GID_FT) {
+			if (lpfc_issue_gidft(vport) > 0)
+				return 1;
+		} else if (phba->cfg_ns_query == LPFC_NS_QUERY_GID_PT) {
+			if (lpfc_issue_gidpt(vport) > 0)
+				return 1;
+		} else {
 			return 1;
+		}
 	} else {
 		/* Nameserver login in question.  Revalidate. */
 		if (ndlp) {

drivers/scsi/lpfc/lpfc_hbadisc.c

@@ -3942,6 +3942,35 @@ lpfc_issue_gidft(struct lpfc_vport *vport)
 	return vport->gidft_inp;
 }
 
+/**
+ * lpfc_issue_gidpt - issue a GID_PT for all N_Ports
+ * @vport: The virtual port for which this call is being executed.
+ *
+ * This routine will issue a GID_PT to get a list of all N_Ports
+ *
+ * Return value :
+ *   0 - Failure to issue a GID_PT
+ *   1 - GID_PT issued
+ **/
+int
+lpfc_issue_gidpt(struct lpfc_vport *vport)
+{
+	/* Good status, issue CT Request to NameServer */
+	if (lpfc_ns_cmd(vport, SLI_CTNS_GID_PT, 0, GID_PT_N_PORT)) {
+		/* Cannot issue NameServer FCP Query, so finish up
+		 * discovery
+		 */
+		lpfc_printf_vlog(vport, KERN_ERR, LOG_SLI,
+				 "0606 %s Port TYPE %x %s\n",
+				 "Failed to issue GID_PT to ",
+				 GID_PT_N_PORT,
+				 "Finishing discovery.");
+		return 0;
+	}
+	vport->gidft_inp++;
+	return 1;
+}
+
 /*
  * This routine handles processing a NameServer REG_LOGIN mailbox
  * command upon completion. It is setup in the LPFC_MBOXQ

drivers/scsi/lpfc/lpfc_hw.h

@@ -115,6 +115,7 @@ struct lpfc_sli_ct_request {
 		uint32_t PortID;
 		struct gid {
 			uint8_t PortType;	/* for GID_PT requests */
+#define GID_PT_N_PORT	1
 			uint8_t DomainScope;
 			uint8_t AreaScope;
 			uint8_t Fc4Type;	/* for GID_FT requests */

drivers/scsi/lpfc/lpfc_hw4.h

@@ -197,6 +197,10 @@ struct lpfc_sli_intf {
 #define	LPFC_FCP_SCHED_ROUND_ROBIN	0
 #define	LPFC_FCP_SCHED_BY_CPU		1
 
+/* Algrithmns for NameServer Query after RSCN */
+#define LPFC_NS_QUERY_GID_FT	0
+#define LPFC_NS_QUERY_GID_PT	1
+
 /* Delay Multiplier constant */
 #define LPFC_DMULT_CONST       651042
 #define LPFC_DMULT_MAX         1023

drivers/scsi/lpfc/lpfc_nportdisc.c

@@ -1775,9 +1775,16 @@ lpfc_cmpl_reglogin_reglogin_issue(struct lpfc_vport *vport,
 			ndlp->nlp_fc4_type |= NLP_FC4_FCP;
 
 		} else if (ndlp->nlp_fc4_type == 0) {
-			rc = lpfc_ns_cmd(vport, SLI_CTNS_GFT_ID,
-					 0, ndlp->nlp_DID);
-			return ndlp->nlp_state;
+			/* If we are only configured for FCP, the driver
+			 * should just issue PRLI for FCP. Otherwise issue
+			 * GFT_ID to determine if remote port supports NVME.
+			 */
+			if (phba->cfg_enable_fc4_type != LPFC_ENABLE_FCP) {
+				rc = lpfc_ns_cmd(vport, SLI_CTNS_GFT_ID,
+						 0, ndlp->nlp_DID);
+				return ndlp->nlp_state;
+			}
+			ndlp->nlp_fc4_type = NLP_FC4_FCP;
 		}
 
 		ndlp->nlp_prev_state = NLP_STE_REG_LOGIN_ISSUE;