lpfc: add support to generate RSCN events for nport

This patch adds general RSCN support:

- The ability to transmit an RSCN to the port on the other end of
the link (regular port if pt2pt, or fabric controller if fabric).
- And general recognition of an RSCN ELS when an ELS is received.

Signed-off-by: Dick Kennedy <[e-mail]>
Signed-off-by: James Smart <[e-mail]>
Reviewed-by: Hannes Reinecke <[e-mail]>
Reviewed-by: Arun Easi <[e-mail]>
Signed-off-by: Sagi Grimberg <[e-mail]>
Signed-off-by: Christoph Hellwig <[e-mail]>

drivers/scsi/lpfc/lpfc.h

···
 	uint32_t elsXmitADISC;
 	uint32_t elsXmitLOGO;
 	uint32_t elsXmitSCR;
+	uint32_t elsXmitRSCN;
 	uint32_t elsXmitRNID;
 	uint32_t elsXmitFARP;
 	uint32_t elsXmitFARPR;

drivers/scsi/lpfc/lpfc_crtn.h

···
 int lpfc_issue_els_logo(struct lpfc_vport *, struct lpfc_nodelist *, uint8_t);
 int lpfc_issue_els_npiv_logo(struct lpfc_vport *, struct lpfc_nodelist *);
 int lpfc_issue_els_scr(struct lpfc_vport *, uint32_t, uint8_t);
+int lpfc_issue_els_rscn(struct lpfc_vport *vport, uint8_t retry);
 int lpfc_issue_fabric_reglogin(struct lpfc_vport *);
 int lpfc_els_free_iocb(struct lpfc_hba *, struct lpfc_iocbq *);
 int lpfc_ct_free_iocb(struct lpfc_hba *, struct lpfc_iocbq *);
···
 struct lpfc_nodelist *lpfc_findnode_did(struct lpfc_vport *, uint32_t);
 struct lpfc_nodelist *lpfc_findnode_wwpn(struct lpfc_vport *,
 					 struct lpfc_name *);
+struct lpfc_nodelist *lpfc_findnode_mapped(struct lpfc_vport *vport);
 
 int lpfc_sli_issue_mbox_wait(struct lpfc_hba *, LPFC_MBOXQ_t *, uint32_t);
 

drivers/scsi/lpfc/lpfc_els.c

···
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_transport_fc.h>
+#include <uapi/scsi/fc/fc_fs.h>
+#include <uapi/scsi/fc/fc_els.h>
 
 #include "lpfc_hw4.h"
 #include "lpfc_hw.h"
···
 	 */
 	if (!(vport->fc_flag & FC_PT2PT))
 		lpfc_nlp_put(ndlp);
+	return 0;
+}
+
+/**
+ * lpfc_issue_els_rscn - Issue an RSCN to the Fabric Controller (Fabric)
+ *   or the other nport (pt2pt).
+ * @vport: pointer to a host virtual N_Port data structure.
+ * @retry: number of retries to the command IOCB.
+ *
+ * This routine issues a RSCN to the Fabric Controller (DID 0xFFFFFD)
+ *  when connected to a fabric, or to the remote port when connected
+ *  in point-to-point mode. When sent to the Fabric Controller, it will
+ *  replay the RSCN to registered recipients.
+ *
+ * Note that, in lpfc_prep_els_iocb() routine, the reference count of ndlp
+ * will be incremented by 1 for holding the ndlp and the reference to ndlp
+ * will be stored into the context1 field of the IOCB for the completion
+ * callback function to the RSCN ELS command.
+ *
+ * Return code
+ *   0 - Successfully issued RSCN command
+ *   1 - Failed to issue RSCN command
+ **/
+int
+lpfc_issue_els_rscn(struct lpfc_vport *vport, uint8_t retry)
+{
+	struct lpfc_hba *phba = vport->phba;
+	struct lpfc_iocbq *elsiocb;
+	struct lpfc_nodelist *ndlp;
+	struct {
+		struct fc_els_rscn rscn;
+		struct fc_els_rscn_page portid;
+	} *event;
+	uint32_t nportid;
+	uint16_t cmdsize = sizeof(*event);
+
+	/* Not supported for private loop */
+	if (phba->fc_topology == LPFC_TOPOLOGY_LOOP &&
+	    !(vport->fc_flag & FC_PUBLIC_LOOP))
+		return 1;
+
+	if (vport->fc_flag & FC_PT2PT) {
+		/* find any mapped nport - that would be the other nport */
+		ndlp = lpfc_findnode_mapped(vport);
+		if (!ndlp)
+			return 1;
+	} else {
+		nportid = FC_FID_FCTRL;
+		/* find the fabric controller node */
+		ndlp = lpfc_findnode_did(vport, nportid);
+		if (!ndlp) {
+			/* if one didn't exist, make one */
+			ndlp = lpfc_nlp_init(vport, nportid);
+			if (!ndlp)
+				return 1;
+			lpfc_enqueue_node(vport, ndlp);
+		} else if (!NLP_CHK_NODE_ACT(ndlp)) {
+			ndlp = lpfc_enable_node(vport, ndlp,
+						NLP_STE_UNUSED_NODE);
+			if (!ndlp)
+				return 1;
+		}
+	}
+
+	elsiocb = lpfc_prep_els_iocb(vport, 1, cmdsize, retry, ndlp,
+				     ndlp->nlp_DID, ELS_CMD_RSCN_XMT);
+
+	if (!elsiocb) {
+		/* This will trigger the release of the node just
+		 * allocated
+		 */
+		lpfc_nlp_put(ndlp);
+		return 1;
+	}
+
+	event = ((struct lpfc_dmabuf *)elsiocb->context2)->virt;
+
+	event->rscn.rscn_cmd = ELS_RSCN;
+	event->rscn.rscn_page_len = sizeof(struct fc_els_rscn_page);
+	event->rscn.rscn_plen = cpu_to_be16(cmdsize);
+
+	nportid = vport->fc_myDID;
+	/* appears that page flags must be 0 for fabric to broadcast RSCN */
+	event->portid.rscn_page_flags = 0;
+	event->portid.rscn_fid[0] = (nportid & 0x00FF0000) >> 16;
+	event->portid.rscn_fid[1] = (nportid & 0x0000FF00) >> 8;
+	event->portid.rscn_fid[2] = nportid & 0x000000FF;
+
+	lpfc_debugfs_disc_trc(vport, LPFC_DISC_TRC_ELS_CMD,
+			      "Issue RSCN:       did:x%x",
+			      ndlp->nlp_DID, 0, 0);
+
+	phba->fc_stat.elsXmitRSCN++;
+	elsiocb->iocb_cmpl = lpfc_cmpl_els_cmd;
+	if (lpfc_sli_issue_iocb(phba, LPFC_ELS_RING, elsiocb, 0) ==
+	    IOCB_ERROR) {
+		/* The additional lpfc_nlp_put will cause the following
+		 * lpfc_els_free_iocb routine to trigger the rlease of
+		 * the node.
+		 */
+		lpfc_nlp_put(ndlp);
+		lpfc_els_free_iocb(phba, elsiocb);
+		return 1;
+	}
+	/* This will cause the callback-function lpfc_cmpl_els_cmd to
+	 * trigger the release of node.
+	 */
+	if (!(vport->fc_flag & FC_PT2PT))
+		lpfc_nlp_put(ndlp);
+
 	return 0;
 }
 
···
 	for (i = 0; i < payload_len/sizeof(uint32_t); i++)
 		fc_host_post_event(shost, fc_get_event_number(),
 			FCH_EVT_RSCN, lp[i]);
+
+	/* Check if RSCN is coming from a direct-connected remote NPort */
+	if (vport->fc_flag & FC_PT2PT) {
+		/* If so, just ACC it, no other action needed for now */
+		lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
+				 "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);
+		return 0;
+	}
 
 	/* If we are about to begin discovery, just ACC the RSCN.
 	 * Discovery processing will satisfy it.

drivers/scsi/lpfc/lpfc_hbadisc.c

···
 }
 
 struct lpfc_nodelist *
+lpfc_findnode_mapped(struct lpfc_vport *vport)
+{
+	struct Scsi_Host *shost = lpfc_shost_from_vport(vport);
+	struct lpfc_nodelist *ndlp;
+	uint32_t data1;
+	unsigned long iflags;
+
+	spin_lock_irqsave(shost->host_lock, iflags);
+
+	list_for_each_entry(ndlp, &vport->fc_nodes, nlp_listp) {
+		if (ndlp->nlp_state == NLP_STE_UNMAPPED_NODE ||
+		    ndlp->nlp_state == NLP_STE_MAPPED_NODE) {
+			data1 = (((uint32_t)ndlp->nlp_state << 24) |
+				 ((uint32_t)ndlp->nlp_xri << 16) |
+				 ((uint32_t)ndlp->nlp_type << 8) |
+				 ((uint32_t)ndlp->nlp_rpi & 0xff));
+			spin_unlock_irqrestore(shost->host_lock, iflags);
+			lpfc_printf_vlog(vport, KERN_INFO, LOG_NODE,
+					 "2025 FIND node DID "
+					 "Data: x%p x%x x%x x%x %p\n",
+					 ndlp, ndlp->nlp_DID,
+					 ndlp->nlp_flag, data1,
+					 ndlp->active_rrqs_xri_bitmap);
+			return ndlp;
+		}
+	}
+	spin_unlock_irqrestore(shost->host_lock, iflags);
+
+	/* FIND node did <did> NOT FOUND */
+	lpfc_printf_vlog(vport, KERN_INFO, LOG_NODE,
+			 "2026 FIND mapped did NOT FOUND.\n");
+	return NULL;
+}
+
+struct lpfc_nodelist *
 lpfc_setup_disc_node(struct lpfc_vport *vport, uint32_t did)
 {
 	struct Scsi_Host *shost = lpfc_shost_from_vport(vport);

drivers/scsi/lpfc/lpfc_hw.h

···
 #define ELS_CMD_RPL       0x57000000
 #define ELS_CMD_FAN       0x60000000
 #define ELS_CMD_RSCN      0x61040000
+#define ELS_CMD_RSCN_XMT  0x61040008
 #define ELS_CMD_SCR       0x62000000
 #define ELS_CMD_RNID      0x78000000
 #define ELS_CMD_LIRR      0x7A000000
···
 #define ELS_CMD_RPL       0x57
 #define ELS_CMD_FAN       0x60
 #define ELS_CMD_RSCN      0x0461
+#define ELS_CMD_RSCN_XMT  0x08000461
 #define ELS_CMD_SCR       0x62
 #define ELS_CMD_RNID      0x78
 #define ELS_CMD_LIRR      0x7A

drivers/scsi/lpfc/lpfc_sli.c

···
 		if (if_type >= LPFC_SLI_INTF_IF_TYPE_2) {
 			if (pcmd && (*pcmd == ELS_CMD_FLOGI ||
 				*pcmd == ELS_CMD_SCR ||
+				*pcmd == ELS_CMD_RSCN_XMT ||
 				*pcmd == ELS_CMD_FDISC ||
 				*pcmd == ELS_CMD_LOGO ||
 				*pcmd == ELS_CMD_PLOGI)) {