[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>

4 files changed, 137 insertions, 1 deletions

diff --git a/drivers/scsi/libfc/Makefile b/drivers/scsi/libfc/Makefile
index 2be549c1db77..4bb23ac86a5c 100644
--- a/drivers/scsi/libfc/Makefile
+++ b/drivers/scsi/libfc/Makefile
@@ -10,4 +10,5 @@ libfc-objs := \
         fc_frame.o \
         fc_lport.o \
         fc_rport.o \
-        fc_fcp.o
+        fc_fcp.o \
+        fc_npiv.o
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index ee6031e24c14..751a485685d9 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -1134,6 +1134,15 @@ static void fc_exch_recv_req(struct fc_lport *lp, struct fc_exch_mgr *mp,
         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) {
@@ -1900,6 +1909,26 @@ void fc_exch_mgr_del(struct fc_exch_mgr_anchor *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,
                                       u16 min_xid, u16 max_xid,
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;
+}
+
diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
index ed3057b4e78d..2c6d55de8ccd 100644
--- a/include/scsi/libfc.h
+++ b/include/scsi/libfc.h
@@ -640,6 +640,8 @@ struct fc_lport {
         /* 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;
@@ -664,6 +666,8 @@ struct fc_lport {
         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;
@@ -753,6 +757,7 @@ libfc_host_alloc(struct scsi_host_template *sht, int priv_size)
         lport = shost_priv(shost);
         lport->host = shost;
         INIT_LIST_HEAD(&lport->ema_list);
+        INIT_LIST_HEAD(&lport->vports);
         return lport;
 }
 
@@ -805,6 +810,15 @@ int fc_lport_reset(struct fc_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
@@ -912,6 +926,12 @@ struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
 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).
  *
  * The EM manages exchanges for their allocation and