Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / scsi / fcoe / fcoe_transport.c
diff --git a/kernel/drivers/scsi/fcoe/fcoe_transport.c b/kernel/drivers/scsi/fcoe/fcoe_transport.c
new file mode 100644 (file)
index 0000000..bdc8989
--- /dev/null
@@ -0,0 +1,1040 @@
+/*
+ * Copyright(c) 2008 - 2011 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
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/errno.h>
+#include <linux/crc32.h>
+#include <scsi/libfcoe.h>
+
+#include "libfcoe.h"
+
+MODULE_AUTHOR("Open-FCoE.org");
+MODULE_DESCRIPTION("FIP discovery protocol and FCoE transport for FCoE HBAs");
+MODULE_LICENSE("GPL v2");
+
+static int fcoe_transport_create(const char *, struct kernel_param *);
+static int fcoe_transport_destroy(const char *, struct kernel_param *);
+static int fcoe_transport_show(char *buffer, const struct kernel_param *kp);
+static struct fcoe_transport *fcoe_transport_lookup(struct net_device *device);
+static struct fcoe_transport *fcoe_netdev_map_lookup(struct net_device *device);
+static int fcoe_transport_enable(const char *, struct kernel_param *);
+static int fcoe_transport_disable(const char *, struct kernel_param *);
+static int libfcoe_device_notification(struct notifier_block *notifier,
+                                   ulong event, void *ptr);
+
+static LIST_HEAD(fcoe_transports);
+static DEFINE_MUTEX(ft_mutex);
+static LIST_HEAD(fcoe_netdevs);
+static DEFINE_MUTEX(fn_mutex);
+
+unsigned int libfcoe_debug_logging;
+module_param_named(debug_logging, libfcoe_debug_logging, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
+
+module_param_call(show, NULL, fcoe_transport_show, NULL, S_IRUSR);
+__MODULE_PARM_TYPE(show, "string");
+MODULE_PARM_DESC(show, " Show attached FCoE transports");
+
+module_param_call(create, fcoe_transport_create, NULL,
+                 (void *)FIP_MODE_FABRIC, S_IWUSR);
+__MODULE_PARM_TYPE(create, "string");
+MODULE_PARM_DESC(create, " Creates fcoe instance on a ethernet interface");
+
+module_param_call(create_vn2vn, fcoe_transport_create, NULL,
+                 (void *)FIP_MODE_VN2VN, S_IWUSR);
+__MODULE_PARM_TYPE(create_vn2vn, "string");
+MODULE_PARM_DESC(create_vn2vn, " Creates a VN_node to VN_node FCoE instance "
+                "on an Ethernet interface");
+
+module_param_call(destroy, fcoe_transport_destroy, NULL, NULL, S_IWUSR);
+__MODULE_PARM_TYPE(destroy, "string");
+MODULE_PARM_DESC(destroy, " Destroys fcoe instance on a ethernet interface");
+
+module_param_call(enable, fcoe_transport_enable, NULL, NULL, S_IWUSR);
+__MODULE_PARM_TYPE(enable, "string");
+MODULE_PARM_DESC(enable, " Enables fcoe on a ethernet interface.");
+
+module_param_call(disable, fcoe_transport_disable, NULL, NULL, S_IWUSR);
+__MODULE_PARM_TYPE(disable, "string");
+MODULE_PARM_DESC(disable, " Disables fcoe on a ethernet interface.");
+
+/* notification function for packets from net device */
+static struct notifier_block libfcoe_notifier = {
+       .notifier_call = libfcoe_device_notification,
+};
+
+/**
+ * fcoe_link_speed_update() - Update the supported and actual link speeds
+ * @lport: The local port to update speeds for
+ *
+ * Returns: 0 if the ethtool query was successful
+ *          -1 if the ethtool query failed
+ */
+int fcoe_link_speed_update(struct fc_lport *lport)
+{
+       struct net_device *netdev = fcoe_get_netdev(lport);
+       struct ethtool_cmd ecmd;
+
+       if (!__ethtool_get_settings(netdev, &ecmd)) {
+               lport->link_supported_speeds &= ~(FC_PORTSPEED_1GBIT  |
+                                                 FC_PORTSPEED_10GBIT |
+                                                 FC_PORTSPEED_20GBIT |
+                                                 FC_PORTSPEED_40GBIT);
+
+               if (ecmd.supported & (SUPPORTED_1000baseT_Half |
+                                     SUPPORTED_1000baseT_Full |
+                                     SUPPORTED_1000baseKX_Full))
+                       lport->link_supported_speeds |= FC_PORTSPEED_1GBIT;
+
+               if (ecmd.supported & (SUPPORTED_10000baseT_Full   |
+                                     SUPPORTED_10000baseKX4_Full |
+                                     SUPPORTED_10000baseKR_Full  |
+                                     SUPPORTED_10000baseR_FEC))
+                       lport->link_supported_speeds |= FC_PORTSPEED_10GBIT;
+
+               if (ecmd.supported & (SUPPORTED_20000baseMLD2_Full |
+                                     SUPPORTED_20000baseKR2_Full))
+                       lport->link_supported_speeds |= FC_PORTSPEED_20GBIT;
+
+               if (ecmd.supported & (SUPPORTED_40000baseKR4_Full |
+                                     SUPPORTED_40000baseCR4_Full |
+                                     SUPPORTED_40000baseSR4_Full |
+                                     SUPPORTED_40000baseLR4_Full))
+                       lport->link_supported_speeds |= FC_PORTSPEED_40GBIT;
+
+               switch (ethtool_cmd_speed(&ecmd)) {
+               case SPEED_1000:
+                       lport->link_speed = FC_PORTSPEED_1GBIT;
+                       break;
+               case SPEED_10000:
+                       lport->link_speed = FC_PORTSPEED_10GBIT;
+                       break;
+               case 20000:
+                       lport->link_speed = FC_PORTSPEED_20GBIT;
+                       break;
+               case 40000:
+                       lport->link_speed = FC_PORTSPEED_40GBIT;
+                       break;
+               default:
+                       lport->link_speed = FC_PORTSPEED_UNKNOWN;
+                       break;
+               }
+               return 0;
+       }
+       return -1;
+}
+EXPORT_SYMBOL_GPL(fcoe_link_speed_update);
+
+/**
+ * __fcoe_get_lesb() - Get the Link Error Status Block (LESB) for a given lport
+ * @lport: The local port to update speeds for
+ * @fc_lesb: Pointer to the LESB to be filled up
+ * @netdev: Pointer to the netdev that is associated with the lport
+ *
+ * Note, the Link Error Status Block (LESB) for FCoE is defined in FC-BB-6
+ * Clause 7.11 in v1.04.
+ */
+void __fcoe_get_lesb(struct fc_lport *lport,
+                    struct fc_els_lesb *fc_lesb,
+                    struct net_device *netdev)
+{
+       unsigned int cpu;
+       u32 lfc, vlfc, mdac;
+       struct fc_stats *stats;
+       struct fcoe_fc_els_lesb *lesb;
+       struct rtnl_link_stats64 temp;
+
+       lfc = 0;
+       vlfc = 0;
+       mdac = 0;
+       lesb = (struct fcoe_fc_els_lesb *)fc_lesb;
+       memset(lesb, 0, sizeof(*lesb));
+       for_each_possible_cpu(cpu) {
+               stats = per_cpu_ptr(lport->stats, cpu);
+               lfc += stats->LinkFailureCount;
+               vlfc += stats->VLinkFailureCount;
+               mdac += stats->MissDiscAdvCount;
+       }
+       lesb->lesb_link_fail = htonl(lfc);
+       lesb->lesb_vlink_fail = htonl(vlfc);
+       lesb->lesb_miss_fka = htonl(mdac);
+       lesb->lesb_fcs_error =
+                       htonl(dev_get_stats(netdev, &temp)->rx_crc_errors);
+}
+EXPORT_SYMBOL_GPL(__fcoe_get_lesb);
+
+/**
+ * fcoe_get_lesb() - Fill the FCoE Link Error Status Block
+ * @lport: the local port
+ * @fc_lesb: the link error status block
+ */
+void fcoe_get_lesb(struct fc_lport *lport,
+                        struct fc_els_lesb *fc_lesb)
+{
+       struct net_device *netdev = fcoe_get_netdev(lport);
+
+       __fcoe_get_lesb(lport, fc_lesb, netdev);
+}
+EXPORT_SYMBOL_GPL(fcoe_get_lesb);
+
+/**
+ * fcoe_ctlr_get_lesb() - Get the Link Error Status Block (LESB) for a given
+ * fcoe controller device
+ * @ctlr_dev: The given fcoe controller device
+ *
+ */
+void fcoe_ctlr_get_lesb(struct fcoe_ctlr_device *ctlr_dev)
+{
+       struct fcoe_ctlr *fip = fcoe_ctlr_device_priv(ctlr_dev);
+       struct net_device *netdev = fcoe_get_netdev(fip->lp);
+       struct fc_els_lesb *fc_lesb;
+
+       fc_lesb = (struct fc_els_lesb *)(&ctlr_dev->lesb);
+       __fcoe_get_lesb(fip->lp, fc_lesb, netdev);
+}
+EXPORT_SYMBOL_GPL(fcoe_ctlr_get_lesb);
+
+void fcoe_wwn_to_str(u64 wwn, char *buf, int len)
+{
+       u8 wwpn[8];
+
+       u64_to_wwn(wwn, wwpn);
+       snprintf(buf, len, "%02x%02x%02x%02x%02x%02x%02x%02x",
+                wwpn[0], wwpn[1], wwpn[2], wwpn[3],
+                wwpn[4], wwpn[5], wwpn[6], wwpn[7]);
+}
+EXPORT_SYMBOL_GPL(fcoe_wwn_to_str);
+
+/**
+ * fcoe_validate_vport_create() - Validate a vport before creating it
+ * @vport: NPIV port to be created
+ *
+ * This routine is meant to add validation for a vport before creating it
+ * via fcoe_vport_create().
+ * Current validations are:
+ *      - WWPN supplied is unique for given lport
+ */
+int fcoe_validate_vport_create(struct fc_vport *vport)
+{
+       struct Scsi_Host *shost = vport_to_shost(vport);
+       struct fc_lport *n_port = shost_priv(shost);
+       struct fc_lport *vn_port;
+       int rc = 0;
+       char buf[32];
+
+       mutex_lock(&n_port->lp_mutex);
+
+       fcoe_wwn_to_str(vport->port_name, buf, sizeof(buf));
+       /* Check if the wwpn is not same as that of the lport */
+       if (!memcmp(&n_port->wwpn, &vport->port_name, sizeof(u64))) {
+               LIBFCOE_TRANSPORT_DBG("vport WWPN 0x%s is same as that of the "
+                                     "base port WWPN\n", buf);
+               rc = -EINVAL;
+               goto out;
+       }
+
+       /* Check if there is any existing vport with same wwpn */
+       list_for_each_entry(vn_port, &n_port->vports, list) {
+               if (!memcmp(&vn_port->wwpn, &vport->port_name, sizeof(u64))) {
+                       LIBFCOE_TRANSPORT_DBG("vport with given WWPN 0x%s "
+                                             "already exists\n", buf);
+                       rc = -EINVAL;
+                       break;
+               }
+       }
+out:
+       mutex_unlock(&n_port->lp_mutex);
+       return rc;
+}
+EXPORT_SYMBOL_GPL(fcoe_validate_vport_create);
+
+/**
+ * fcoe_get_wwn() - Get the world wide name from LLD if it supports it
+ * @netdev: the associated net device
+ * @wwn: the output WWN
+ * @type: the type of WWN (WWPN or WWNN)
+ *
+ * Returns: 0 for success
+ */
+int fcoe_get_wwn(struct net_device *netdev, u64 *wwn, int type)
+{
+       const struct net_device_ops *ops = netdev->netdev_ops;
+
+       if (ops->ndo_fcoe_get_wwn)
+               return ops->ndo_fcoe_get_wwn(netdev, wwn, type);
+       return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(fcoe_get_wwn);
+
+/**
+ * fcoe_fc_crc() - Calculates the CRC for a given frame
+ * @fp: The frame to be checksumed
+ *
+ * This uses crc32() routine to calculate the CRC for a frame
+ *
+ * Return: The 32 bit CRC value
+ */
+u32 fcoe_fc_crc(struct fc_frame *fp)
+{
+       struct sk_buff *skb = fp_skb(fp);
+       struct skb_frag_struct *frag;
+       unsigned char *data;
+       unsigned long off, len, clen;
+       u32 crc;
+       unsigned i;
+
+       crc = crc32(~0, skb->data, skb_headlen(skb));
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               frag = &skb_shinfo(skb)->frags[i];
+               off = frag->page_offset;
+               len = skb_frag_size(frag);
+               while (len > 0) {
+                       clen = min(len, PAGE_SIZE - (off & ~PAGE_MASK));
+                       data = kmap_atomic(
+                               skb_frag_page(frag) + (off >> PAGE_SHIFT));
+                       crc = crc32(crc, data + (off & ~PAGE_MASK), clen);
+                       kunmap_atomic(data);
+                       off += clen;
+                       len -= clen;
+               }
+       }
+       return crc;
+}
+EXPORT_SYMBOL_GPL(fcoe_fc_crc);
+
+/**
+ * fcoe_start_io() - Start FCoE I/O
+ * @skb: The packet to be transmitted
+ *
+ * This routine is called from the net device to start transmitting
+ * FCoE packets.
+ *
+ * Returns: 0 for success
+ */
+int fcoe_start_io(struct sk_buff *skb)
+{
+       struct sk_buff *nskb;
+       int rc;
+
+       nskb = skb_clone(skb, GFP_ATOMIC);
+       if (!nskb)
+               return -ENOMEM;
+       rc = dev_queue_xmit(nskb);
+       if (rc != 0)
+               return rc;
+       kfree_skb(skb);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(fcoe_start_io);
+
+
+/**
+ * fcoe_clean_pending_queue() - Dequeue a skb and free it
+ * @lport: The local port to dequeue a skb on
+ */
+void fcoe_clean_pending_queue(struct fc_lport *lport)
+{
+       struct fcoe_port  *port = lport_priv(lport);
+       struct sk_buff *skb;
+
+       spin_lock_bh(&port->fcoe_pending_queue.lock);
+       while ((skb = __skb_dequeue(&port->fcoe_pending_queue)) != NULL) {
+               spin_unlock_bh(&port->fcoe_pending_queue.lock);
+               kfree_skb(skb);
+               spin_lock_bh(&port->fcoe_pending_queue.lock);
+       }
+       spin_unlock_bh(&port->fcoe_pending_queue.lock);
+}
+EXPORT_SYMBOL_GPL(fcoe_clean_pending_queue);
+
+/**
+ * fcoe_check_wait_queue() - Attempt to clear the transmit backlog
+ * @lport: The local port whose backlog is to be cleared
+ *
+ * This empties the wait_queue, dequeues the head of the wait_queue queue
+ * and calls fcoe_start_io() for each packet. If all skb have been
+ * transmitted it returns the qlen. If an error occurs it restores
+ * wait_queue (to try again later) and returns -1.
+ *
+ * The wait_queue is used when the skb transmit fails. The failed skb
+ * will go in the wait_queue which will be emptied by the timer function or
+ * by the next skb transmit.
+ */
+void fcoe_check_wait_queue(struct fc_lport *lport, struct sk_buff *skb)
+{
+       struct fcoe_port *port = lport_priv(lport);
+       int rc;
+
+       spin_lock_bh(&port->fcoe_pending_queue.lock);
+
+       if (skb)
+               __skb_queue_tail(&port->fcoe_pending_queue, skb);
+
+       if (port->fcoe_pending_queue_active)
+               goto out;
+       port->fcoe_pending_queue_active = 1;
+
+       while (port->fcoe_pending_queue.qlen) {
+               /* keep qlen > 0 until fcoe_start_io succeeds */
+               port->fcoe_pending_queue.qlen++;
+               skb = __skb_dequeue(&port->fcoe_pending_queue);
+
+               spin_unlock_bh(&port->fcoe_pending_queue.lock);
+               rc = fcoe_start_io(skb);
+               spin_lock_bh(&port->fcoe_pending_queue.lock);
+
+               if (rc) {
+                       __skb_queue_head(&port->fcoe_pending_queue, skb);
+                       /* undo temporary increment above */
+                       port->fcoe_pending_queue.qlen--;
+                       break;
+               }
+               /* undo temporary increment above */
+               port->fcoe_pending_queue.qlen--;
+       }
+
+       if (port->fcoe_pending_queue.qlen < port->min_queue_depth)
+               lport->qfull = 0;
+       if (port->fcoe_pending_queue.qlen && !timer_pending(&port->timer))
+               mod_timer(&port->timer, jiffies + 2);
+       port->fcoe_pending_queue_active = 0;
+out:
+       if (port->fcoe_pending_queue.qlen > port->max_queue_depth)
+               lport->qfull = 1;
+       spin_unlock_bh(&port->fcoe_pending_queue.lock);
+}
+EXPORT_SYMBOL_GPL(fcoe_check_wait_queue);
+
+/**
+ * fcoe_queue_timer() - The fcoe queue timer
+ * @lport: The local port
+ *
+ * Calls fcoe_check_wait_queue on timeout
+ */
+void fcoe_queue_timer(ulong lport)
+{
+       fcoe_check_wait_queue((struct fc_lport *)lport, NULL);
+}
+EXPORT_SYMBOL_GPL(fcoe_queue_timer);
+
+/**
+ * fcoe_get_paged_crc_eof() - Allocate a page to be used for the trailer CRC
+ * @skb:  The packet to be transmitted
+ * @tlen: The total length of the trailer
+ * @fps:  The fcoe context
+ *
+ * This routine allocates a page for frame trailers. The page is re-used if
+ * there is enough room left on it for the current trailer. If there isn't
+ * enough buffer left a new page is allocated for the trailer. Reference to
+ * the page from this function as well as the skbs using the page fragments
+ * ensure that the page is freed at the appropriate time.
+ *
+ * Returns: 0 for success
+ */
+int fcoe_get_paged_crc_eof(struct sk_buff *skb, int tlen,
+                          struct fcoe_percpu_s *fps)
+{
+       struct page *page;
+
+       page = fps->crc_eof_page;
+       if (!page) {
+               page = alloc_page(GFP_ATOMIC);
+               if (!page)
+                       return -ENOMEM;
+
+               fps->crc_eof_page = page;
+               fps->crc_eof_offset = 0;
+       }
+
+       get_page(page);
+       skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, page,
+                          fps->crc_eof_offset, tlen);
+       skb->len += tlen;
+       skb->data_len += tlen;
+       skb->truesize += tlen;
+       fps->crc_eof_offset += sizeof(struct fcoe_crc_eof);
+
+       if (fps->crc_eof_offset >= PAGE_SIZE) {
+               fps->crc_eof_page = NULL;
+               fps->crc_eof_offset = 0;
+               put_page(page);
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(fcoe_get_paged_crc_eof);
+
+/**
+ * fcoe_transport_lookup - find an fcoe transport that matches a netdev
+ * @netdev: The netdev to look for from all attached transports
+ *
+ * Returns : ptr to the fcoe transport that supports this netdev or NULL
+ * if not found.
+ *
+ * The ft_mutex should be held when this is called
+ */
+static struct fcoe_transport *fcoe_transport_lookup(struct net_device *netdev)
+{
+       struct fcoe_transport *ft = NULL;
+
+       list_for_each_entry(ft, &fcoe_transports, list)
+               if (ft->match && ft->match(netdev))
+                       return ft;
+       return NULL;
+}
+
+/**
+ * fcoe_transport_attach - Attaches an FCoE transport
+ * @ft: The fcoe transport to be attached
+ *
+ * Returns : 0 for success
+ */
+int fcoe_transport_attach(struct fcoe_transport *ft)
+{
+       int rc = 0;
+
+       mutex_lock(&ft_mutex);
+       if (ft->attached) {
+               LIBFCOE_TRANSPORT_DBG("transport %s already attached\n",
+                                      ft->name);
+               rc = -EEXIST;
+               goto out_attach;
+       }
+
+       /* Add default transport to the tail */
+       if (strcmp(ft->name, FCOE_TRANSPORT_DEFAULT))
+               list_add(&ft->list, &fcoe_transports);
+       else
+               list_add_tail(&ft->list, &fcoe_transports);
+
+       ft->attached = true;
+       LIBFCOE_TRANSPORT_DBG("attaching transport %s\n", ft->name);
+
+out_attach:
+       mutex_unlock(&ft_mutex);
+       return rc;
+}
+EXPORT_SYMBOL(fcoe_transport_attach);
+
+/**
+ * fcoe_transport_detach - Detaches an FCoE transport
+ * @ft: The fcoe transport to be attached
+ *
+ * Returns : 0 for success
+ */
+int fcoe_transport_detach(struct fcoe_transport *ft)
+{
+       int rc = 0;
+       struct fcoe_netdev_mapping *nm = NULL, *tmp;
+
+       mutex_lock(&ft_mutex);
+       if (!ft->attached) {
+               LIBFCOE_TRANSPORT_DBG("transport %s already detached\n",
+                       ft->name);
+               rc = -ENODEV;
+               goto out_attach;
+       }
+
+       /* remove netdev mapping for this transport as it is going away */
+       mutex_lock(&fn_mutex);
+       list_for_each_entry_safe(nm, tmp, &fcoe_netdevs, list) {
+               if (nm->ft == ft) {
+                       LIBFCOE_TRANSPORT_DBG("transport %s going away, "
+                               "remove its netdev mapping for %s\n",
+                               ft->name, nm->netdev->name);
+                       list_del(&nm->list);
+                       kfree(nm);
+               }
+       }
+       mutex_unlock(&fn_mutex);
+
+       list_del(&ft->list);
+       ft->attached = false;
+       LIBFCOE_TRANSPORT_DBG("detaching transport %s\n", ft->name);
+
+out_attach:
+       mutex_unlock(&ft_mutex);
+       return rc;
+
+}
+EXPORT_SYMBOL(fcoe_transport_detach);
+
+static int fcoe_transport_show(char *buffer, const struct kernel_param *kp)
+{
+       int i, j;
+       struct fcoe_transport *ft = NULL;
+
+       i = j = sprintf(buffer, "Attached FCoE transports:");
+       mutex_lock(&ft_mutex);
+       list_for_each_entry(ft, &fcoe_transports, list) {
+               if (i >= PAGE_SIZE - IFNAMSIZ)
+                       break;
+               i += snprintf(&buffer[i], IFNAMSIZ, "%s ", ft->name);
+       }
+       mutex_unlock(&ft_mutex);
+       if (i == j)
+               i += snprintf(&buffer[i], IFNAMSIZ, "none");
+       return i;
+}
+
+static int __init fcoe_transport_init(void)
+{
+       register_netdevice_notifier(&libfcoe_notifier);
+       return 0;
+}
+
+static int fcoe_transport_exit(void)
+{
+       struct fcoe_transport *ft;
+
+       unregister_netdevice_notifier(&libfcoe_notifier);
+       mutex_lock(&ft_mutex);
+       list_for_each_entry(ft, &fcoe_transports, list)
+               printk(KERN_ERR "FCoE transport %s is still attached!\n",
+                     ft->name);
+       mutex_unlock(&ft_mutex);
+       return 0;
+}
+
+
+static int fcoe_add_netdev_mapping(struct net_device *netdev,
+                                       struct fcoe_transport *ft)
+{
+       struct fcoe_netdev_mapping *nm;
+
+       nm = kmalloc(sizeof(*nm), GFP_KERNEL);
+       if (!nm) {
+               printk(KERN_ERR "Unable to allocate netdev_mapping");
+               return -ENOMEM;
+       }
+
+       nm->netdev = netdev;
+       nm->ft = ft;
+
+       mutex_lock(&fn_mutex);
+       list_add(&nm->list, &fcoe_netdevs);
+       mutex_unlock(&fn_mutex);
+       return 0;
+}
+
+
+static void fcoe_del_netdev_mapping(struct net_device *netdev)
+{
+       struct fcoe_netdev_mapping *nm = NULL, *tmp;
+
+       mutex_lock(&fn_mutex);
+       list_for_each_entry_safe(nm, tmp, &fcoe_netdevs, list) {
+               if (nm->netdev == netdev) {
+                       list_del(&nm->list);
+                       kfree(nm);
+                       mutex_unlock(&fn_mutex);
+                       return;
+               }
+       }
+       mutex_unlock(&fn_mutex);
+}
+
+
+/**
+ * fcoe_netdev_map_lookup - find the fcoe transport that matches the netdev on which
+ * it was created
+ *
+ * Returns : ptr to the fcoe transport that supports this netdev or NULL
+ * if not found.
+ *
+ * The ft_mutex should be held when this is called
+ */
+static struct fcoe_transport *fcoe_netdev_map_lookup(struct net_device *netdev)
+{
+       struct fcoe_transport *ft = NULL;
+       struct fcoe_netdev_mapping *nm;
+
+       mutex_lock(&fn_mutex);
+       list_for_each_entry(nm, &fcoe_netdevs, list) {
+               if (netdev == nm->netdev) {
+                       ft = nm->ft;
+                       mutex_unlock(&fn_mutex);
+                       return ft;
+               }
+       }
+
+       mutex_unlock(&fn_mutex);
+       return NULL;
+}
+
+/**
+ * fcoe_if_to_netdev() - Parse a name buffer to get a net device
+ * @buffer: The name of the net device
+ *
+ * Returns: NULL or a ptr to net_device
+ */
+static struct net_device *fcoe_if_to_netdev(const char *buffer)
+{
+       char *cp;
+       char ifname[IFNAMSIZ + 2];
+
+       if (buffer) {
+               strlcpy(ifname, buffer, IFNAMSIZ);
+               cp = ifname + strlen(ifname);
+               while (--cp >= ifname && *cp == '\n')
+                       *cp = '\0';
+               return dev_get_by_name(&init_net, ifname);
+       }
+       return NULL;
+}
+
+/**
+ * libfcoe_device_notification() - Handler for net device events
+ * @notifier: The context of the notification
+ * @event:    The type of event
+ * @ptr:      The net device that the event was on
+ *
+ * This function is called by the Ethernet driver in case of link change event.
+ *
+ * Returns: 0 for success
+ */
+static int libfcoe_device_notification(struct notifier_block *notifier,
+                                   ulong event, void *ptr)
+{
+       struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+
+       switch (event) {
+       case NETDEV_UNREGISTER:
+               LIBFCOE_TRANSPORT_DBG("NETDEV_UNREGISTER %s\n",
+                                     netdev->name);
+               fcoe_del_netdev_mapping(netdev);
+               break;
+       }
+       return NOTIFY_OK;
+}
+
+ssize_t fcoe_ctlr_create_store(struct bus_type *bus,
+                              const char *buf, size_t count)
+{
+       struct net_device *netdev = NULL;
+       struct fcoe_transport *ft = NULL;
+       int rc = 0;
+       int err;
+
+       mutex_lock(&ft_mutex);
+
+       netdev = fcoe_if_to_netdev(buf);
+       if (!netdev) {
+               LIBFCOE_TRANSPORT_DBG("Invalid device %s.\n", buf);
+               rc = -ENODEV;
+               goto out_nodev;
+       }
+
+       ft = fcoe_netdev_map_lookup(netdev);
+       if (ft) {
+               LIBFCOE_TRANSPORT_DBG("transport %s already has existing "
+                                     "FCoE instance on %s.\n",
+                                     ft->name, netdev->name);
+               rc = -EEXIST;
+               goto out_putdev;
+       }
+
+       ft = fcoe_transport_lookup(netdev);
+       if (!ft) {
+               LIBFCOE_TRANSPORT_DBG("no FCoE transport found for %s.\n",
+                                     netdev->name);
+               rc = -ENODEV;
+               goto out_putdev;
+       }
+
+       /* pass to transport create */
+       err = ft->alloc ? ft->alloc(netdev) : -ENODEV;
+       if (err) {
+               fcoe_del_netdev_mapping(netdev);
+               rc = -ENOMEM;
+               goto out_putdev;
+       }
+
+       err = fcoe_add_netdev_mapping(netdev, ft);
+       if (err) {
+               LIBFCOE_TRANSPORT_DBG("failed to add new netdev mapping "
+                                     "for FCoE transport %s for %s.\n",
+                                     ft->name, netdev->name);
+               rc = -ENODEV;
+               goto out_putdev;
+       }
+
+       LIBFCOE_TRANSPORT_DBG("transport %s succeeded to create fcoe on %s.\n",
+                             ft->name, netdev->name);
+
+out_putdev:
+       dev_put(netdev);
+out_nodev:
+       mutex_unlock(&ft_mutex);
+       if (rc)
+               return rc;
+       return count;
+}
+
+ssize_t fcoe_ctlr_destroy_store(struct bus_type *bus,
+                               const char *buf, size_t count)
+{
+       int rc = -ENODEV;
+       struct net_device *netdev = NULL;
+       struct fcoe_transport *ft = NULL;
+
+       mutex_lock(&ft_mutex);
+
+       netdev = fcoe_if_to_netdev(buf);
+       if (!netdev) {
+               LIBFCOE_TRANSPORT_DBG("invalid device %s.\n", buf);
+               goto out_nodev;
+       }
+
+       ft = fcoe_netdev_map_lookup(netdev);
+       if (!ft) {
+               LIBFCOE_TRANSPORT_DBG("no FCoE transport found for %s.\n",
+                                     netdev->name);
+               goto out_putdev;
+       }
+
+       /* pass to transport destroy */
+       rc = ft->destroy(netdev);
+       if (rc)
+               goto out_putdev;
+
+       fcoe_del_netdev_mapping(netdev);
+       LIBFCOE_TRANSPORT_DBG("transport %s %s to destroy fcoe on %s.\n",
+                             ft->name, (rc) ? "failed" : "succeeded",
+                             netdev->name);
+       rc = count; /* required for successful return */
+out_putdev:
+       dev_put(netdev);
+out_nodev:
+       mutex_unlock(&ft_mutex);
+       return rc;
+}
+EXPORT_SYMBOL(fcoe_ctlr_destroy_store);
+
+/**
+ * fcoe_transport_create() - Create a fcoe interface
+ * @buffer: The name of the Ethernet interface to create on
+ * @kp:            The associated kernel param
+ *
+ * Called from sysfs. This holds the ft_mutex while calling the
+ * registered fcoe transport's create function.
+ *
+ * Returns: 0 for success
+ */
+static int fcoe_transport_create(const char *buffer, struct kernel_param *kp)
+{
+       int rc = -ENODEV;
+       struct net_device *netdev = NULL;
+       struct fcoe_transport *ft = NULL;
+       enum fip_state fip_mode = (enum fip_state)(long)kp->arg;
+
+       mutex_lock(&ft_mutex);
+
+       netdev = fcoe_if_to_netdev(buffer);
+       if (!netdev) {
+               LIBFCOE_TRANSPORT_DBG("Invalid device %s.\n", buffer);
+               goto out_nodev;
+       }
+
+       ft = fcoe_netdev_map_lookup(netdev);
+       if (ft) {
+               LIBFCOE_TRANSPORT_DBG("transport %s already has existing "
+                                     "FCoE instance on %s.\n",
+                                     ft->name, netdev->name);
+               rc = -EEXIST;
+               goto out_putdev;
+       }
+
+       ft = fcoe_transport_lookup(netdev);
+       if (!ft) {
+               LIBFCOE_TRANSPORT_DBG("no FCoE transport found for %s.\n",
+                                     netdev->name);
+               goto out_putdev;
+       }
+
+       rc = fcoe_add_netdev_mapping(netdev, ft);
+       if (rc) {
+               LIBFCOE_TRANSPORT_DBG("failed to add new netdev mapping "
+                                     "for FCoE transport %s for %s.\n",
+                                     ft->name, netdev->name);
+               goto out_putdev;
+       }
+
+       /* pass to transport create */
+       rc = ft->create ? ft->create(netdev, fip_mode) : -ENODEV;
+       if (rc)
+               fcoe_del_netdev_mapping(netdev);
+
+       LIBFCOE_TRANSPORT_DBG("transport %s %s to create fcoe on %s.\n",
+                             ft->name, (rc) ? "failed" : "succeeded",
+                             netdev->name);
+
+out_putdev:
+       dev_put(netdev);
+out_nodev:
+       mutex_unlock(&ft_mutex);
+       return rc;
+}
+
+/**
+ * fcoe_transport_destroy() - Destroy a FCoE interface
+ * @buffer: The name of the Ethernet interface to be destroyed
+ * @kp:            The associated kernel parameter
+ *
+ * Called from sysfs. This holds the ft_mutex while calling the
+ * registered fcoe transport's destroy function.
+ *
+ * Returns: 0 for success
+ */
+static int fcoe_transport_destroy(const char *buffer, struct kernel_param *kp)
+{
+       int rc = -ENODEV;
+       struct net_device *netdev = NULL;
+       struct fcoe_transport *ft = NULL;
+
+       mutex_lock(&ft_mutex);
+
+       netdev = fcoe_if_to_netdev(buffer);
+       if (!netdev) {
+               LIBFCOE_TRANSPORT_DBG("invalid device %s.\n", buffer);
+               goto out_nodev;
+       }
+
+       ft = fcoe_netdev_map_lookup(netdev);
+       if (!ft) {
+               LIBFCOE_TRANSPORT_DBG("no FCoE transport found for %s.\n",
+                                     netdev->name);
+               goto out_putdev;
+       }
+
+       /* pass to transport destroy */
+       rc = ft->destroy ? ft->destroy(netdev) : -ENODEV;
+       fcoe_del_netdev_mapping(netdev);
+       LIBFCOE_TRANSPORT_DBG("transport %s %s to destroy fcoe on %s.\n",
+                             ft->name, (rc) ? "failed" : "succeeded",
+                             netdev->name);
+
+out_putdev:
+       dev_put(netdev);
+out_nodev:
+       mutex_unlock(&ft_mutex);
+       return rc;
+}
+
+/**
+ * fcoe_transport_disable() - Disables a FCoE interface
+ * @buffer: The name of the Ethernet interface to be disabled
+ * @kp:            The associated kernel parameter
+ *
+ * Called from sysfs.
+ *
+ * Returns: 0 for success
+ */
+static int fcoe_transport_disable(const char *buffer, struct kernel_param *kp)
+{
+       int rc = -ENODEV;
+       struct net_device *netdev = NULL;
+       struct fcoe_transport *ft = NULL;
+
+       mutex_lock(&ft_mutex);
+
+       netdev = fcoe_if_to_netdev(buffer);
+       if (!netdev)
+               goto out_nodev;
+
+       ft = fcoe_netdev_map_lookup(netdev);
+       if (!ft)
+               goto out_putdev;
+
+       rc = ft->disable ? ft->disable(netdev) : -ENODEV;
+
+out_putdev:
+       dev_put(netdev);
+out_nodev:
+       mutex_unlock(&ft_mutex);
+       return rc;
+}
+
+/**
+ * fcoe_transport_enable() - Enables a FCoE interface
+ * @buffer: The name of the Ethernet interface to be enabled
+ * @kp:     The associated kernel parameter
+ *
+ * Called from sysfs.
+ *
+ * Returns: 0 for success
+ */
+static int fcoe_transport_enable(const char *buffer, struct kernel_param *kp)
+{
+       int rc = -ENODEV;
+       struct net_device *netdev = NULL;
+       struct fcoe_transport *ft = NULL;
+
+       mutex_lock(&ft_mutex);
+
+       netdev = fcoe_if_to_netdev(buffer);
+       if (!netdev)
+               goto out_nodev;
+
+       ft = fcoe_netdev_map_lookup(netdev);
+       if (!ft)
+               goto out_putdev;
+
+       rc = ft->enable ? ft->enable(netdev) : -ENODEV;
+
+out_putdev:
+       dev_put(netdev);
+out_nodev:
+       mutex_unlock(&ft_mutex);
+       return rc;
+}
+
+/**
+ * libfcoe_init() - Initialization routine for libfcoe.ko
+ */
+static int __init libfcoe_init(void)
+{
+       int rc = 0;
+
+       rc = fcoe_transport_init();
+       if (rc)
+               return rc;
+
+       rc = fcoe_sysfs_setup();
+       if (rc)
+               fcoe_transport_exit();
+
+       return rc;
+}
+module_init(libfcoe_init);
+
+/**
+ * libfcoe_exit() - Tear down libfcoe.ko
+ */
+static void __exit libfcoe_exit(void)
+{
+       fcoe_sysfs_teardown();
+       fcoe_transport_exit();
+}
+module_exit(libfcoe_exit);