[SCSI] libfc: add some generic NPIV support routines to libfc

Adds a function to create a new VN_Port instances, which share the EM
list with the N_Port, VN_Port lookup by fabric ID when responding to a new
request (otherwise the exchange lookup from the N_Ports EM list is trusted to
return an exchange with a cached lport value for the correct VN_Port),
a pointer to a fc_vport structure for VN_Ports, and flags to indicate if an
N_Port supports NPIV and if the switch/fabric allows it.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 86 insertions, 0 deletions

diff --git a/drivers/scsi/libfc/fc_npiv.c b/drivers/scsi/libfc/fc_npiv.c
new file mode 100644
index 000000000000..39f02c09a8d9
--- /dev/null
+++ b/drivers/scsi/libfc/fc_npiv.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright(c) 2009 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Maintained at www.Open-FCoE.org
+ */
+
+/*
+ * NPIV VN_Port helper functions for libfc
+ */
+
+#include <scsi/libfc.h>
+
+/**
+ * fc_vport_create() - Create a new NPIV vport instance
+ * @vport: fc_vport structure from scsi_transport_fc
+ * @privsize: driver private data size to allocate along with the Scsi_Host
+ */
+
+struct fc_lport *libfc_vport_create(struct fc_vport *vport, int privsize)
+{
+	struct Scsi_Host *shost = vport_to_shost(vport);
+	struct fc_lport *n_port = shost_priv(shost);
+	struct fc_lport *vn_port;
+
+	vn_port = libfc_host_alloc(shost->hostt, privsize);
+	if (!vn_port)
+		goto err_out;
+	if (fc_exch_mgr_list_clone(n_port, vn_port))
+		goto err_put;
+
+	vn_port->vport = vport;
+	vport->dd_data = vn_port;
+
+	mutex_lock(&n_port->lp_mutex);
+	list_add_tail(&vn_port->list, &n_port->vports);
+	mutex_unlock(&n_port->lp_mutex);
+
+	return vn_port;
+
+err_put:
+	scsi_host_put(vn_port->host);
+err_out:
+	return NULL;
+}
+EXPORT_SYMBOL(libfc_vport_create);
+
+/**
+ * fc_vport_id_lookup() - find NPIV lport that matches a given fabric ID
+ * @n_port: Top level N_Port which may have multiple NPIV VN_Ports
+ * @port_id: Fabric ID to find a match for
+ *
+ * Returns: matching lport pointer or NULL if there is no match
+ */
+struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id)
+{
+	struct fc_lport *lport = NULL;
+	struct fc_lport *vn_port;
+
+	if (fc_host_port_id(n_port->host) == port_id)
+		return n_port;
+
+	mutex_lock(&n_port->lp_mutex);
+	list_for_each_entry(vn_port, &n_port->vports, list) {
+		if (fc_host_port_id(vn_port->host) == port_id) {
+			lport = vn_port;
+			break;
+		}
+	}
+	mutex_unlock(&n_port->lp_mutex);
+
+	return lport;
+}
+