Re: [PATCH v5 11/31] elx: libefc: SLI and FC PORT state machine interfaces

This patch continues the libefc library population.

This patch adds library interface definitions for:
- SLI and FC port (aka n_port_id) registration, allocation and
   deallocation.

Co-developed-by: Ram Vegesna <ram.vegesna@broadcom.com>
Signed-off-by: Ram Vegesna <ram.vegesna@broadcom.com>
Signed-off-by: James Smart <redacted>
---
  drivers/scsi/elx/libefc/efc_nport.c | 794 ++++++++++++++++++++++++++++
  drivers/scsi/elx/libefc/efc_nport.h |  50 ++
  2 files changed, 844 insertions(+)
  create mode 100644 drivers/scsi/elx/libefc/efc_nport.c
  create mode 100644 drivers/scsi/elx/libefc/efc_nport.h

diff --git a/drivers/scsi/elx/libefc/efc_nport.c b/drivers/scsi/elx/libefc/efc_nport.c
new file mode 100644
index 000000000000..fad42cd8a108
--- /dev/null
+++ b/drivers/scsi/elx/libefc/efc_nport.c

@@ -0,0 +1,794 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Broadcom. All Rights Reserved. The term
+ * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
+ */
+
+/*
+ * NPORT
+ *
+ * Port object for physical port and NPIV ports.
+ */
+
+/*
+ * NPORT REFERENCE COUNTING
+ *
+ * A nport reference should be taken when:
+ * - an nport is allocated
+ * - a vport populates associated nport
+ * - a remote node is allocated
+ * - a unsolicited frame is processed
+ * The reference should be dropped when:
+ * - the unsolicited frame processesing is done
+ * - the remote node is removed
+ * - the vport is removed
+ * - the nport is removed
+ */
+
+#include "efc.h"
+
+int
+efc_nport_cb(void *arg, int event, void *data)
+{
+	struct efc *efc = arg;
+	struct efc_nport *nport = data;
+	unsigned long flags = 0;
+
+	efc_log_debug(efc, "nport event: %s\n", efc_sm_event_name(event));
+
+	spin_lock_irqsave(&efc->lock, flags);
+	efc_sm_post_event(&nport->sm, event, NULL);
+	spin_unlock_irqrestore(&efc->lock, flags);
+
+	return EFC_SUCCESS;
+}
+
+static struct efc_nport *
+efc_nport_find_wwn(struct efc_domain *domain, uint64_t wwnn, uint64_t wwpn)
+{
+	struct efc_nport *nport = NULL;
+
+	/* Find a nport, given the WWNN and WWPN */
+	list_for_each_entry(nport, &domain->nport_list, list_entry) {
+		if (nport->wwnn == wwnn && nport->wwpn == wwpn)
+			return nport;
+	}
+	return NULL;
+}
+
+static void
+_efc_nport_free(struct kref *arg)
+{
+	struct efc_nport *nport = container_of(arg, struct efc_nport, ref);
+
+	kfree(nport);
+}
+
+struct efc_nport *
+efc_nport_alloc(struct efc_domain *domain, uint64_t wwpn, uint64_t wwnn,
+		u32 fc_id, bool enable_ini, bool enable_tgt)
+{
+	struct efc_nport *nport;
+
+	if (domain->efc->enable_ini)
+		enable_ini = 0;
+
+	/* Return a failure if this nport has already been allocated */
+	if ((wwpn != 0) || (wwnn != 0)) {
+		nport = efc_nport_find_wwn(domain, wwnn, wwpn);
+		if (nport) {
+			efc_log_err(domain->efc,
+				"Err: NPORT %016llX %016llX already allocated\n",
+				wwnn, wwpn);
+			return NULL;
+		}
+	}
+
+	nport = kzalloc(sizeof(*nport), GFP_ATOMIC);
+	if (!nport)
+		return nport;
+
+	/* initialize refcount */
+	kref_init(&nport->ref);
+	nport->release = _efc_nport_free;
+
+	nport->efc = domain->efc;
+	snprintf(nport->display_name, sizeof(nport->display_name), "------");
+	nport->domain = domain;
+	xa_init(&nport->lookup);
+	nport->instance_index = domain->nport_count++;
+	nport->sm.app = nport;
+	nport->enable_ini = enable_ini;
+	nport->enable_tgt = enable_tgt;
+	nport->enable_rscn = (nport->enable_ini ||
+			(nport->enable_tgt && enable_target_rscn(nport->efc)));
+
+	/* Copy service parameters from domain */
+	memcpy(nport->service_params, domain->service_params,
+		sizeof(struct fc_els_flogi));
+
+	/* Update requested fc_id */
+	nport->fc_id = fc_id;
+
+	/* Update the nport's service parameters for the new wwn's */
+	nport->wwpn = wwpn;
+	nport->wwnn = wwnn;
+	snprintf(nport->wwnn_str, sizeof(nport->wwnn_str), "%016llX",
+			(unsigned long long)wwnn);
+
+	/*
+	 * if this is the "first" nport of the domain,
+	 * then make it the "phys" nport
+	 */
+	if (list_empty(&domain->nport_list))
+		domain->nport = nport;
+
+	INIT_LIST_HEAD(&nport->list_entry);
+	list_add_tail(&nport->list_entry, &domain->nport_list);
+
+	kref_get(&domain->ref);
+
+	efc_log_debug(domain->efc, "New Nport [%s]\n", nport->display_name);
+
+	return nport;
+}
+
+void
+efc_nport_free(struct efc_nport *nport)
+{
+	struct efc_domain *domain;
+
+	if (!nport)
+		return;
+
+	domain = nport->domain;
+	efc_log_debug(domain->efc, "[%s] free nport\n", nport->display_name);
+	list_del(&nport->list_entry);
+	/*
+	 * if this is the physical nport,
+	 * then clear it out of the domain
+	 */
+	if (nport == domain->nport)
+		domain->nport = NULL;
+
+	xa_destroy(&nport->lookup);
+	xa_erase(&domain->lookup, nport->fc_id);
+
+	if (list_empty(&domain->nport_list))
+		efc_domain_post_event(domain, EFC_EVT_ALL_CHILD_NODES_FREE,
+				      NULL);
+
+	kref_put(&domain->ref, domain->release);
+	kref_put(&nport->ref, nport->release);
+
+}
+
+struct efc_nport *
+efc_nport_find(struct efc_domain *domain, u32 d_id)
+{
+	struct efc_nport *nport;
+
+	/* Find a nport object, given an FC_ID */
+	nport = xa_load(&domain->lookup, d_id);
+	if (!nport || !kref_get_unless_zero(&nport->ref))
+		return NULL;
+
+	return nport;
+}
+
+int
+efc_nport_attach(struct efc_nport *nport, u32 fc_id)
+{
+	int rc;
+	struct efc_node *node;
+	struct efc *efc = nport->efc;
+	unsigned long index;
+
+	/* Set our lookup */
+	rc = xa_err(xa_store(&nport->domain->lookup, fc_id, nport, GFP_ATOMIC));
+	if (rc) {
+		efc_log_err(efc, "Sport lookup store failed: %d\n", rc);
+		return rc;
+	}
+
+	/* Update our display_name */
+	efc_node_fcid_display(fc_id, nport->display_name,
+			      sizeof(nport->display_name));
+
+	xa_for_each(&nport->lookup, index, node) {
+		efc_node_update_display_name(node);
+	}
+
+	efc_log_debug(nport->efc, "[%s] attach nport: fc_id x%06x\n",
+		      nport->display_name, fc_id);
+
+	/* Register a nport, given an FC_ID */
+	rc = efc_cmd_nport_attach(efc, nport, fc_id);
+	if (rc != EFC_HW_RTN_SUCCESS) {
+		efc_log_err(nport->efc,
+			    "efc_hw_port_attach failed: %d\n", rc);
+		return EFC_FAIL;
+	}
+	return EFC_SUCCESS;
+}
+
+static void
+efc_nport_shutdown(struct efc_nport *nport)
+{
+	struct efc *efc = nport->efc;
+	struct efc_node *node;
+	unsigned long index;
+
+	xa_for_each(&nport->lookup, index, node) {
+		if (!(node->rnode.fc_id == FC_FID_FLOGI && nport->is_vport)) {
+			efc_node_post_event(node, EFC_EVT_SHUTDOWN, NULL);
+			continue;
+		}
+
+		/*
+		 * If this is a vport, logout of the fabric
+		 * controller so that it deletes the vport
+		 * on the switch.
+		 */
+		/* if link is down, don't send logo */
+		if (efc->link_status == EFC_LINK_STATUS_DOWN) {
+			efc_node_post_event(node, EFC_EVT_SHUTDOWN, NULL);
+			continue;
+		}
+
+		efc_log_debug(efc, "[%s] nport shutdown vport, send logo\n",
+					node->display_name);
+
+		if (!efc_send_logo(node)) {
+			/* sent LOGO, wait for response */
+			efc_node_transition(node, __efc_d_wait_logo_rsp, NULL);
+			continue;
+		}
+
+		/*
+		 * failed to send LOGO,
+		 * go ahead and cleanup node anyways
+		 */
+		node_printf(node, "Failed to send LOGO\n");
+		efc_node_post_event(node, EFC_EVT_SHUTDOWN_EXPLICIT_LOGO, NULL);
+	}
+}
+
+static void
+efc_vport_link_down(struct efc_nport *nport)
+{
+	struct efc *efc = nport->efc;
+	struct efc_vport_spec *vport;
+
+	/* Clear the nport reference in the vport specification */
+	list_for_each_entry(vport, &efc->vport_list, list_entry) {
+		if (vport->nport == nport) {
+			kref_put(&nport->ref, nport->release);
+			vport->nport = NULL;
+			break;
+		}
+	}
+}
+