[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 <[e-mail]>
Signed-off-by: Robert Love <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/libfc/Makefile

···
 	fc_frame.o \
 	fc_lport.o \
 	fc_rport.o \
-	fc_fcp.o
+	fc_fcp.o \
+	fc_npiv.o

drivers/scsi/libfc/fc_exch.c

···
 	u32 f_ctl;
 	enum fc_pf_rjt_reason reject;
 
+	/* We can have the wrong fc_lport at this point with NPIV, which is a
+	 * problem now that we know a new exchange needs to be allocated
+	 */
+	lp = fc_vport_id_lookup(lp, ntoh24(fh->fh_d_id));
+	if (!lp) {
+		fc_frame_free(fp);
+		return;
+	}
+
 	fr_seq(fp) = NULL;
 	reject = fc_seq_lookup_recip(lp, mp, fp);
 	if (reject == FC_RJT_NONE) {
···
 	kfree(ema);
 }
 EXPORT_SYMBOL(fc_exch_mgr_del);
+
+/**
+ * fc_exch_mgr_list_clone() - share all exchange manager objects
+ * @src: source lport to clone exchange managers from
+ * @dst: new lport that takes references to all the exchange managers
+ */
+int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
+{
+	struct fc_exch_mgr_anchor *ema, *tmp;
+
+	list_for_each_entry(ema, &src->ema_list, ema_list) {
+		if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
+			goto err;
+	}
+	return 0;
+err:
+	list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
+		fc_exch_mgr_del(ema);
+	return -ENOMEM;
+}
 
 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lp,
 				      enum fc_class class,

drivers/scsi/libfc/fc_npiv.c

···
+/*
+ * 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;
+}
+

include/scsi/libfc.h

···
 	/* Associations */
 	struct Scsi_Host	*host;
 	struct list_head	ema_list;
+	struct list_head	vports;		/* child vports if N_Port */
+	struct fc_vport		*vport;		/* parent vport if VN_Port */
 	struct fc_rport_priv	*dns_rp;
 	struct fc_rport_priv	*ptp_rp;
 	void			*scsi_priv;
···
 	u32			seq_offload:1;	/* seq offload supported */
 	u32			crc_offload:1;	/* crc offload supported */
 	u32			lro_enabled:1;	/* large receive offload */
+	u32			does_npiv:1;	/* supports multiple vports */
+	u32			npiv_enabled:1;	/* switch/fabric allows NPIV */
 	u32			mfs;	        /* max FC payload size */
 	unsigned int		service_params;
 	unsigned int		e_d_tov;
···
 	lport = shost_priv(shost);
 	lport->host = shost;
 	INIT_LIST_HEAD(&lport->ema_list);
+	INIT_LIST_HEAD(&lport->vports);
 	return lport;
 }
 
···
  */
 int fc_set_mfs(struct fc_lport *lp, u32 mfs);
 
+/*
+ * Allocate a new lport struct for an NPIV VN_Port
+ */
+struct fc_lport *libfc_vport_create(struct fc_vport *vport, int privsize);
+
+/*
+ * Find an NPIV VN_Port by port ID
+ */
+struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id);
 
 /*
  * REMOTE PORT LAYER
···
  * then also destroys associated EM.
  */
 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema);
+
+/*
+ * Clone an exchange manager list, getting reference holds for each EM.
+ * This is for use with NPIV and sharing the X_ID space between VN_Ports.
+ */
+int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst);
 
 /*
  * Allocates an Exchange Manager (EM).