[SCSI] fcoe: allow SCSI-FCP to be processed directly in softirq context

[safe/jmp/linux-2.6] / drivers / scsi / fcoe / fcoe.c

/*
 * Copyright(c) 2007 - 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
 */

#include <linux/module.h>
#include <linux/version.h>
#include <linux/spinlock.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/crc32.h>
#include <linux/cpu.h>
#include <linux/fs.h>
#include <linux/sysfs.h>
#include <linux/ctype.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsicam.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_fc.h>
#include <net/rtnetlink.h>

#include <scsi/fc/fc_encaps.h>
#include <scsi/fc/fc_fip.h>

#include <scsi/libfc.h>
#include <scsi/fc_frame.h>
#include <scsi/libfcoe.h>

#include "fcoe.h"

MODULE_AUTHOR("Open-FCoE.org");
MODULE_DESCRIPTION("FCoE");
MODULE_LICENSE("GPL v2");

/* Performance tuning parameters for fcoe */
static unsigned int fcoe_ddp_min;
module_param_named(ddp_min, fcoe_ddp_min, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(ddp_min, "Minimum I/O size in bytes for "      \
                 "Direct Data Placement (DDP).");

DEFINE_MUTEX(fcoe_config_mutex);

/* fcoe_percpu_clean completion.  Waiter protected by fcoe_create_mutex */
static DECLARE_COMPLETION(fcoe_flush_completion);

/* fcoe host list */
/* must only by accessed under the RTNL mutex */
LIST_HEAD(fcoe_hostlist);
DEFINE_PER_CPU(struct fcoe_percpu_s, fcoe_percpu);

/* Function Prototypes */
static int fcoe_reset(struct Scsi_Host *);
static int fcoe_xmit(struct fc_lport *, struct fc_frame *);
static int fcoe_rcv(struct sk_buff *, struct net_device *,
                    struct packet_type *, struct net_device *);
static int fcoe_percpu_receive_thread(void *);
static void fcoe_clean_pending_queue(struct fc_lport *);
static void fcoe_percpu_clean(struct fc_lport *);
static int fcoe_link_ok(struct fc_lport *);

static struct fc_lport *fcoe_hostlist_lookup(const struct net_device *);
static int fcoe_hostlist_add(const struct fc_lport *);

static void fcoe_check_wait_queue(struct fc_lport *, struct sk_buff *);
static int fcoe_device_notification(struct notifier_block *, ulong, void *);
static void fcoe_dev_setup(void);
static void fcoe_dev_cleanup(void);
static struct fcoe_interface
*fcoe_hostlist_lookup_port(const struct net_device *);

static int fcoe_fip_recv(struct sk_buff *, struct net_device *,
                         struct packet_type *, struct net_device *);

static void fcoe_fip_send(struct fcoe_ctlr *, struct sk_buff *);
static void fcoe_update_src_mac(struct fc_lport *, u8 *);
static u8 *fcoe_get_src_mac(struct fc_lport *);
static void fcoe_destroy_work(struct work_struct *);

static int fcoe_ddp_setup(struct fc_lport *, u16, struct scatterlist *,
                          unsigned int);
static int fcoe_ddp_done(struct fc_lport *, u16);

static int fcoe_cpu_callback(struct notifier_block *, unsigned long, void *);

static int fcoe_create(const char *, struct kernel_param *);
static int fcoe_destroy(const char *, struct kernel_param *);

static struct fc_seq *fcoe_elsct_send(struct fc_lport *,
                                      u32 did, struct fc_frame *,
                                      unsigned int op,
                                      void (*resp)(struct fc_seq *,
                                                   struct fc_frame *,
                                                   void *),
                                      void *, u32 timeout);
static void fcoe_recv_frame(struct sk_buff *skb);

module_param_call(create, fcoe_create, NULL, NULL, S_IWUSR);
__MODULE_PARM_TYPE(create, "string");
MODULE_PARM_DESC(create, "Create fcoe fcoe using net device passed in.");
module_param_call(destroy, fcoe_destroy, NULL, NULL, S_IWUSR);
__MODULE_PARM_TYPE(destroy, "string");
MODULE_PARM_DESC(destroy, "Destroy fcoe fcoe");

/* notification function for packets from net device */
static struct notifier_block fcoe_notifier = {
        .notifier_call = fcoe_device_notification,
};

/* notification function for CPU hotplug events */
static struct notifier_block fcoe_cpu_notifier = {
        .notifier_call = fcoe_cpu_callback,
};

static struct scsi_transport_template *fcoe_transport_template;
static struct scsi_transport_template *fcoe_vport_transport_template;

static int fcoe_vport_destroy(struct fc_vport *);
static int fcoe_vport_create(struct fc_vport *, bool disabled);
static int fcoe_vport_disable(struct fc_vport *, bool disable);
static void fcoe_set_vport_symbolic_name(struct fc_vport *);

static struct libfc_function_template fcoe_libfc_fcn_templ = {
        .frame_send = fcoe_xmit,
        .ddp_setup = fcoe_ddp_setup,
        .ddp_done = fcoe_ddp_done,
        .elsct_send = fcoe_elsct_send,
};

struct fc_function_template fcoe_transport_function = {
        .show_host_node_name = 1,
        .show_host_port_name = 1,
        .show_host_supported_classes = 1,
        .show_host_supported_fc4s = 1,
        .show_host_active_fc4s = 1,
        .show_host_maxframe_size = 1,

        .show_host_port_id = 1,
        .show_host_supported_speeds = 1,
        .get_host_speed = fc_get_host_speed,
        .show_host_speed = 1,
        .show_host_port_type = 1,
        .get_host_port_state = fc_get_host_port_state,
        .show_host_port_state = 1,
        .show_host_symbolic_name = 1,

        .dd_fcrport_size = sizeof(struct fc_rport_libfc_priv),
        .show_rport_maxframe_size = 1,
        .show_rport_supported_classes = 1,

        .show_host_fabric_name = 1,
        .show_starget_node_name = 1,
        .show_starget_port_name = 1,
        .show_starget_port_id = 1,
        .set_rport_dev_loss_tmo = fc_set_rport_loss_tmo,
        .show_rport_dev_loss_tmo = 1,
        .get_fc_host_stats = fc_get_host_stats,
        .issue_fc_host_lip = fcoe_reset,

        .terminate_rport_io = fc_rport_terminate_io,

        .vport_create = fcoe_vport_create,
        .vport_delete = fcoe_vport_destroy,
        .vport_disable = fcoe_vport_disable,
        .set_vport_symbolic_name = fcoe_set_vport_symbolic_name,

        .bsg_request = fc_lport_bsg_request,
};

struct fc_function_template fcoe_vport_transport_function = {
        .show_host_node_name = 1,
        .show_host_port_name = 1,
        .show_host_supported_classes = 1,
        .show_host_supported_fc4s = 1,
        .show_host_active_fc4s = 1,
        .show_host_maxframe_size = 1,

        .show_host_port_id = 1,
        .show_host_supported_speeds = 1,
        .get_host_speed = fc_get_host_speed,
        .show_host_speed = 1,
        .show_host_port_type = 1,
        .get_host_port_state = fc_get_host_port_state,
        .show_host_port_state = 1,
        .show_host_symbolic_name = 1,

        .dd_fcrport_size = sizeof(struct fc_rport_libfc_priv),
        .show_rport_maxframe_size = 1,
        .show_rport_supported_classes = 1,

        .show_host_fabric_name = 1,
        .show_starget_node_name = 1,
        .show_starget_port_name = 1,
        .show_starget_port_id = 1,
        .set_rport_dev_loss_tmo = fc_set_rport_loss_tmo,
        .show_rport_dev_loss_tmo = 1,
        .get_fc_host_stats = fc_get_host_stats,
        .issue_fc_host_lip = fcoe_reset,

        .terminate_rport_io = fc_rport_terminate_io,

        .bsg_request = fc_lport_bsg_request,
};

static struct scsi_host_template fcoe_shost_template = {
        .module = THIS_MODULE,
        .name = "FCoE Driver",
        .proc_name = FCOE_NAME,
        .queuecommand = fc_queuecommand,
        .eh_abort_handler = fc_eh_abort,
        .eh_device_reset_handler = fc_eh_device_reset,
        .eh_host_reset_handler = fc_eh_host_reset,
        .slave_alloc = fc_slave_alloc,
        .change_queue_depth = fc_change_queue_depth,
        .change_queue_type = fc_change_queue_type,
        .this_id = -1,
        .cmd_per_lun = 3,
        .can_queue = FCOE_MAX_OUTSTANDING_COMMANDS,
        .use_clustering = ENABLE_CLUSTERING,
        .sg_tablesize = SG_ALL,
        .max_sectors = 0xffff,
};

/**
 * fcoe_interface_setup() - Setup a FCoE interface
 * @fcoe:   The new FCoE interface
 * @netdev: The net device that the fcoe interface is on
 *
 * Returns : 0 for success
 * Locking: must be called with the RTNL mutex held
 */
static int fcoe_interface_setup(struct fcoe_interface *fcoe,
                                struct net_device *netdev)
{
        struct fcoe_ctlr *fip = &fcoe->ctlr;
        struct netdev_hw_addr *ha;
        struct net_device *real_dev;
        u8 flogi_maddr[ETH_ALEN];
        const struct net_device_ops *ops;

        fcoe->netdev = netdev;

        /* Let LLD initialize for FCoE */
        ops = netdev->netdev_ops;
        if (ops->ndo_fcoe_enable) {
                if (ops->ndo_fcoe_enable(netdev))
                        FCOE_NETDEV_DBG(netdev, "Failed to enable FCoE"
                                        " specific feature for LLD.\n");
        }

        /* Do not support for bonding device */
        if ((netdev->priv_flags & IFF_MASTER_ALB) ||
            (netdev->priv_flags & IFF_SLAVE_INACTIVE) ||
            (netdev->priv_flags & IFF_MASTER_8023AD)) {
                FCOE_NETDEV_DBG(netdev, "Bonded interfaces not supported\n");
                return -EOPNOTSUPP;
        }

        /* look for SAN MAC address, if multiple SAN MACs exist, only
         * use the first one for SPMA */
        real_dev = (netdev->priv_flags & IFF_802_1Q_VLAN) ?
                vlan_dev_real_dev(netdev) : netdev;
        rcu_read_lock();
        for_each_dev_addr(real_dev, ha) {
                if ((ha->type == NETDEV_HW_ADDR_T_SAN) &&
                    (is_valid_ether_addr(ha->addr))) {
                        memcpy(fip->ctl_src_addr, ha->addr, ETH_ALEN);
                        fip->spma = 1;
                        break;
                }
        }
        rcu_read_unlock();

        /* setup Source Mac Address */
        if (!fip->spma)
                memcpy(fip->ctl_src_addr, netdev->dev_addr, netdev->addr_len);

        /*
         * Add FCoE MAC address as second unicast MAC address
         * or enter promiscuous mode if not capable of listening
         * for multiple unicast MACs.
         */
        memcpy(flogi_maddr, (u8[6]) FC_FCOE_FLOGI_MAC, ETH_ALEN);
        dev_unicast_add(netdev, flogi_maddr);
        if (fip->spma)
                dev_unicast_add(netdev, fip->ctl_src_addr);
        dev_mc_add(netdev, FIP_ALL_ENODE_MACS, ETH_ALEN, 0);

        /*
         * setup the receive function from ethernet driver
         * on the ethertype for the given device
         */
        fcoe->fcoe_packet_type.func = fcoe_rcv;
        fcoe->fcoe_packet_type.type = __constant_htons(ETH_P_FCOE);
        fcoe->fcoe_packet_type.dev = netdev;
        dev_add_pack(&fcoe->fcoe_packet_type);

        fcoe->fip_packet_type.func = fcoe_fip_recv;
        fcoe->fip_packet_type.type = htons(ETH_P_FIP);
        fcoe->fip_packet_type.dev = netdev;
        dev_add_pack(&fcoe->fip_packet_type);

        return 0;
}

/**
 * fcoe_interface_create() - Create a FCoE interface on a net device
 * @netdev: The net device to create the FCoE interface on
 *
 * Returns: pointer to a struct fcoe_interface or NULL on error
 */
static struct fcoe_interface *fcoe_interface_create(struct net_device *netdev)
{
        struct fcoe_interface *fcoe;
        int err;

        fcoe = kzalloc(sizeof(*fcoe), GFP_KERNEL);
        if (!fcoe) {
                FCOE_NETDEV_DBG(netdev, "Could not allocate fcoe structure\n");
                return NULL;
        }

        dev_hold(netdev);
        kref_init(&fcoe->kref);

        /*
         * Initialize FIP.
         */
        fcoe_ctlr_init(&fcoe->ctlr);
        fcoe->ctlr.send = fcoe_fip_send;
        fcoe->ctlr.update_mac = fcoe_update_src_mac;
        fcoe->ctlr.get_src_addr = fcoe_get_src_mac;

        err = fcoe_interface_setup(fcoe, netdev);
        if (err) {
                fcoe_ctlr_destroy(&fcoe->ctlr);
                kfree(fcoe);
                dev_put(netdev);
                return NULL;
        }

        return fcoe;
}

/**
 * fcoe_interface_cleanup() - Clean up a FCoE interface
 * @fcoe: The FCoE interface to be cleaned up
 *
 * Caller must be holding the RTNL mutex
 */
void fcoe_interface_cleanup(struct fcoe_interface *fcoe)
{
        struct net_device *netdev = fcoe->netdev;
        struct fcoe_ctlr *fip = &fcoe->ctlr;
        u8 flogi_maddr[ETH_ALEN];
        const struct net_device_ops *ops;

        /*
         * Don't listen for Ethernet packets anymore.
         * synchronize_net() ensures that the packet handlers are not running
         * on another CPU. dev_remove_pack() would do that, this calls the
         * unsyncronized version __dev_remove_pack() to avoid multiple delays.
         */
        __dev_remove_pack(&fcoe->fcoe_packet_type);
        __dev_remove_pack(&fcoe->fip_packet_type);
        synchronize_net();

        /* Delete secondary MAC addresses */
        memcpy(flogi_maddr, (u8[6]) FC_FCOE_FLOGI_MAC, ETH_ALEN);
        dev_unicast_delete(netdev, flogi_maddr);
        if (fip->spma)
                dev_unicast_delete(netdev, fip->ctl_src_addr);
        dev_mc_delete(netdev, FIP_ALL_ENODE_MACS, ETH_ALEN, 0);

        /* Tell the LLD we are done w/ FCoE */
        ops = netdev->netdev_ops;
        if (ops->ndo_fcoe_disable) {
                if (ops->ndo_fcoe_disable(netdev))
                        FCOE_NETDEV_DBG(netdev, "Failed to disable FCoE"
                                        " specific feature for LLD.\n");
        }
}

/**
 * fcoe_interface_release() - fcoe_port kref release function
 * @kref: Embedded reference count in an fcoe_interface struct
 */
static void fcoe_interface_release(struct kref *kref)
{
        struct fcoe_interface *fcoe;
        struct net_device *netdev;

        fcoe = container_of(kref, struct fcoe_interface, kref);
        netdev = fcoe->netdev;
        /* tear-down the FCoE controller */
        fcoe_ctlr_destroy(&fcoe->ctlr);
        kfree(fcoe);
        dev_put(netdev);
}

/**
 * fcoe_interface_get() - Get a reference to a FCoE interface
 * @fcoe: The FCoE interface to be held
 */
static inline void fcoe_interface_get(struct fcoe_interface *fcoe)
{
        kref_get(&fcoe->kref);
}

/**
 * fcoe_interface_put() - Put a reference to a FCoE interface
 * @fcoe: The FCoE interface to be released
 */
static inline void fcoe_interface_put(struct fcoe_interface *fcoe)
{
        kref_put(&fcoe->kref, fcoe_interface_release);
}

/**
 * fcoe_fip_recv() - Handler for received FIP frames
 * @skb:      The receive skb
 * @netdev:   The associated net device
 * @ptype:    The packet_type structure which was used to register this handler
 * @orig_dev: The original net_device the the skb was received on.
 *            (in case dev is a bond)
 *
 * Returns: 0 for success
 */
static int fcoe_fip_recv(struct sk_buff *skb, struct net_device *netdev,
                         struct packet_type *ptype,
                         struct net_device *orig_dev)
{
        struct fcoe_interface *fcoe;

        fcoe = container_of(ptype, struct fcoe_interface, fip_packet_type);
        fcoe_ctlr_recv(&fcoe->ctlr, skb);
        return 0;
}

/**
 * fcoe_fip_send() - Send an Ethernet-encapsulated FIP frame
 * @fip: The FCoE controller
 * @skb: The FIP packet to be sent
 */
static void fcoe_fip_send(struct fcoe_ctlr *fip, struct sk_buff *skb)
{
        skb->dev = fcoe_from_ctlr(fip)->netdev;
        dev_queue_xmit(skb);
}

/**
 * fcoe_update_src_mac() - Update the Ethernet MAC filters
 * @lport: The local port to update the source MAC on
 * @addr:  Unicast MAC address to add
 *
 * Remove any previously-set unicast MAC filter.
 * Add secondary FCoE MAC address filter for our OUI.
 */
static void fcoe_update_src_mac(struct fc_lport *lport, u8 *addr)
{
        struct fcoe_port *port = lport_priv(lport);
        struct fcoe_interface *fcoe = port->fcoe;

        rtnl_lock();
        if (!is_zero_ether_addr(port->data_src_addr))
                dev_unicast_delete(fcoe->netdev, port->data_src_addr);
        if (!is_zero_ether_addr(addr))
                dev_unicast_add(fcoe->netdev, addr);
        memcpy(port->data_src_addr, addr, ETH_ALEN);
        rtnl_unlock();
}

/**
 * fcoe_get_src_mac() - return the Ethernet source address for an lport
 * @lport: libfc lport
 */
static u8 *fcoe_get_src_mac(struct fc_lport *lport)
{
        struct fcoe_port *port = lport_priv(lport);

        return port->data_src_addr;
}

/**
 * fcoe_lport_config() - Set up a local port
 * @lport: The local port to be setup
 *
 * Returns: 0 for success
 */
static int fcoe_lport_config(struct fc_lport *lport)
{
        lport->link_up = 0;
        lport->qfull = 0;
        lport->max_retry_count = 3;
        lport->max_rport_retry_count = 3;
        lport->e_d_tov = 2 * 1000;      /* FC-FS default */
        lport->r_a_tov = 2 * 2 * 1000;
        lport->service_params = (FCP_SPPF_INIT_FCN | FCP_SPPF_RD_XRDY_DIS |
                                 FCP_SPPF_RETRY | FCP_SPPF_CONF_COMPL);
        lport->does_npiv = 1;

        fc_lport_init_stats(lport);

        /* lport fc_lport related configuration */
        fc_lport_config(lport);

        /* offload related configuration */
        lport->crc_offload = 0;
        lport->seq_offload = 0;
        lport->lro_enabled = 0;
        lport->lro_xid = 0;
        lport->lso_max = 0;

        return 0;
}

/**
 * fcoe_queue_timer() - The fcoe queue timer
 * @lport: The local port
 *
 * Calls fcoe_check_wait_queue on timeout
 */
static void fcoe_queue_timer(ulong lport)
{
        fcoe_check_wait_queue((struct fc_lport *)lport, NULL);
}

/**
 * fcoe_netdev_config() - Set up net devive for SW FCoE
 * @lport:  The local port that is associated with the net device
 * @netdev: The associated net device
 *
 * Must be called after fcoe_lport_config() as it will use local port mutex
 *
 * Returns: 0 for success
 */
static int fcoe_netdev_config(struct fc_lport *lport, struct net_device *netdev)
{
        u32 mfs;
        u64 wwnn, wwpn;
        struct fcoe_interface *fcoe;
        struct fcoe_port *port;
        int vid = 0;

        /* Setup lport private data to point to fcoe softc */
        port = lport_priv(lport);
        fcoe = port->fcoe;

        /*
         * Determine max frame size based on underlying device and optional
         * user-configured limit.  If the MFS is too low, fcoe_link_ok()
         * will return 0, so do this first.
         */
        mfs = netdev->mtu;
        if (netdev->features & NETIF_F_FCOE_MTU) {
                mfs = FCOE_MTU;
                FCOE_NETDEV_DBG(netdev, "Supports FCOE_MTU of %d bytes\n", mfs);
        }
        mfs -= (sizeof(struct fcoe_hdr) + sizeof(struct fcoe_crc_eof));
        if (fc_set_mfs(lport, mfs))
                return -EINVAL;

        /* offload features support */
        if (netdev->features & NETIF_F_SG)
                lport->sg_supp = 1;

        if (netdev->features & NETIF_F_FCOE_CRC) {
                lport->crc_offload = 1;
                FCOE_NETDEV_DBG(netdev, "Supports FCCRC offload\n");
        }
        if (netdev->features & NETIF_F_FSO) {
                lport->seq_offload = 1;
                lport->lso_max = netdev->gso_max_size;
                FCOE_NETDEV_DBG(netdev, "Supports LSO for max len 0x%x\n",
                                lport->lso_max);
        }
        if (netdev->fcoe_ddp_xid) {
                lport->lro_enabled = 1;
                lport->lro_xid = netdev->fcoe_ddp_xid;
                FCOE_NETDEV_DBG(netdev, "Supports LRO for max xid 0x%x\n",
                                lport->lro_xid);
        }
        skb_queue_head_init(&port->fcoe_pending_queue);
        port->fcoe_pending_queue_active = 0;
        setup_timer(&port->timer, fcoe_queue_timer, (unsigned long)lport);

        if (!lport->vport) {
                /*
                 * Use NAA 1&2 (FC-FS Rev. 2.0, Sec. 15) to generate WWNN/WWPN:
                 * For WWNN, we use NAA 1 w/ bit 27-16 of word 0 as 0.
                 * For WWPN, we use NAA 2 w/ bit 27-16 of word 0 from VLAN ID
                 */
                if (netdev->priv_flags & IFF_802_1Q_VLAN)
                        vid = vlan_dev_vlan_id(netdev);
                wwnn = fcoe_wwn_from_mac(fcoe->ctlr.ctl_src_addr, 1, 0);
                fc_set_wwnn(lport, wwnn);
                wwpn = fcoe_wwn_from_mac(fcoe->ctlr.ctl_src_addr, 2, vid);
                fc_set_wwpn(lport, wwpn);
        }

        return 0;
}

/**
 * fcoe_shost_config() - Set up the SCSI host associated with a local port
 * @lport: The local port
 * @shost: The SCSI host to associate with the local port
 * @dev:   The device associated with the SCSI host
 *
 * Must be called after fcoe_lport_config() and fcoe_netdev_config()
 *
 * Returns: 0 for success
 */
static int fcoe_shost_config(struct fc_lport *lport, struct Scsi_Host *shost,
                             struct device *dev)
{
        int rc = 0;

        /* lport scsi host config */
        lport->host->max_lun = FCOE_MAX_LUN;
        lport->host->max_id = FCOE_MAX_FCP_TARGET;
        lport->host->max_channel = 0;
        if (lport->vport)
                lport->host->transportt = fcoe_vport_transport_template;
        else
                lport->host->transportt = fcoe_transport_template;

        /* add the new host to the SCSI-ml */
        rc = scsi_add_host(lport->host, dev);
        if (rc) {
                FCOE_NETDEV_DBG(fcoe_netdev(lport), "fcoe_shost_config: "
                                "error on scsi_add_host\n");
                return rc;
        }

        if (!lport->vport)
                fc_host_max_npiv_vports(lport->host) = USHORT_MAX;

        snprintf(fc_host_symbolic_name(lport->host), FC_SYMBOLIC_NAME_SIZE,
                 "%s v%s over %s", FCOE_NAME, FCOE_VERSION,
                 fcoe_netdev(lport)->name);

        return 0;
}

/**
 * fcoe_oem_match() - The match routine for the offloaded exchange manager
 * @fp: The I/O frame
 *
 * This routine will be associated with an exchange manager (EM). When
 * the libfc exchange handling code is looking for an EM to use it will
 * call this routine and pass it the frame that it wishes to send. This
 * routine will return True if the associated EM is to be used and False
 * if the echange code should continue looking for an EM.
 *
 * The offload EM that this routine is associated with will handle any
 * packets that are for SCSI read requests.
 *
 * Returns: True for read types I/O, otherwise returns false.
 */
bool fcoe_oem_match(struct fc_frame *fp)
{
        return fc_fcp_is_read(fr_fsp(fp)) &&
                (fr_fsp(fp)->data_len > fcoe_ddp_min);
}

/**
 * fcoe_em_config() - Allocate and configure an exchange manager
 * @lport: The local port that the new EM will be associated with
 *
 * Returns: 0 on success
 */
static inline int fcoe_em_config(struct fc_lport *lport)
{
        struct fcoe_port *port = lport_priv(lport);
        struct fcoe_interface *fcoe = port->fcoe;
        struct fcoe_interface *oldfcoe = NULL;
        struct net_device *old_real_dev, *cur_real_dev;
        u16 min_xid = FCOE_MIN_XID;
        u16 max_xid = FCOE_MAX_XID;

        /*
         * Check if need to allocate an em instance for
         * offload exchange ids to be shared across all VN_PORTs/lport.
         */
        if (!lport->lro_enabled || !lport->lro_xid ||
            (lport->lro_xid >= max_xid)) {
                lport->lro_xid = 0;
                goto skip_oem;
        }

        /*
         * Reuse existing offload em instance in case
         * it is already allocated on real eth device
         */
        if (fcoe->netdev->priv_flags & IFF_802_1Q_VLAN)
                cur_real_dev = vlan_dev_real_dev(fcoe->netdev);
        else
                cur_real_dev = fcoe->netdev;

        list_for_each_entry(oldfcoe, &fcoe_hostlist, list) {
                if (oldfcoe->netdev->priv_flags & IFF_802_1Q_VLAN)
                        old_real_dev = vlan_dev_real_dev(oldfcoe->netdev);
                else
                        old_real_dev = oldfcoe->netdev;

                if (cur_real_dev == old_real_dev) {
                        fcoe->oem = oldfcoe->oem;
                        break;
                }
        }

        if (fcoe->oem) {
                if (!fc_exch_mgr_add(lport, fcoe->oem, fcoe_oem_match)) {
                        printk(KERN_ERR "fcoe_em_config: failed to add "
                               "offload em:%p on interface:%s\n",
                               fcoe->oem, fcoe->netdev->name);
                        return -ENOMEM;
                }
        } else {
                fcoe->oem = fc_exch_mgr_alloc(lport, FC_CLASS_3,
                                              FCOE_MIN_XID, lport->lro_xid,
                                              fcoe_oem_match);
                if (!fcoe->oem) {
                        printk(KERN_ERR "fcoe_em_config: failed to allocate "
                               "em for offload exches on interface:%s\n",
                               fcoe->netdev->name);
                        return -ENOMEM;
                }
        }

        /*
         * Exclude offload EM xid range from next EM xid range.
         */
        min_xid += lport->lro_xid + 1;

skip_oem:
        if (!fc_exch_mgr_alloc(lport, FC_CLASS_3, min_xid, max_xid, NULL)) {
                printk(KERN_ERR "fcoe_em_config: failed to "
                       "allocate em on interface %s\n", fcoe->netdev->name);
                return -ENOMEM;
        }

        return 0;
}

/**
 * fcoe_if_destroy() - Tear down a SW FCoE instance
 * @lport: The local port to be destroyed
 */
static void fcoe_if_destroy(struct fc_lport *lport)
{
        struct fcoe_port *port = lport_priv(lport);
        struct fcoe_interface *fcoe = port->fcoe;
        struct net_device *netdev = fcoe->netdev;

        FCOE_NETDEV_DBG(netdev, "Destroying interface\n");

        /* Logout of the fabric */
        fc_fabric_logoff(lport);

        /* Cleanup the fc_lport */
        fc_lport_destroy(lport);
        fc_fcp_destroy(lport);

        /* Stop the transmit retry timer */
        del_timer_sync(&port->timer);

        /* Free existing transmit skbs */
        fcoe_clean_pending_queue(lport);

        rtnl_lock();
        if (!is_zero_ether_addr(port->data_src_addr))
                dev_unicast_delete(netdev, port->data_src_addr);
        rtnl_unlock();

        /* receives may not be stopped until after this */
        fcoe_interface_put(fcoe);

        /* Free queued packets for the per-CPU receive threads */
        fcoe_percpu_clean(lport);

        /* Detach from the scsi-ml */
        fc_remove_host(lport->host);
        scsi_remove_host(lport->host);

        /* There are no more rports or I/O, free the EM */
        fc_exch_mgr_free(lport);

        /* Free memory used by statistical counters */
        fc_lport_free_stats(lport);

        /* Release the Scsi_Host */
        scsi_host_put(lport->host);
}

/**
 * fcoe_ddp_setup() - Call a LLD's ddp_setup through the net device
 * @lport: The local port to setup DDP for
 * @xid:   The exchange ID for this DDP transfer
 * @sgl:   The scatterlist describing this transfer
 * @sgc:   The number of sg items
 *
 * Returns: 0 if the DDP context was not configured
 */
static int fcoe_ddp_setup(struct fc_lport *lport, u16 xid,
                          struct scatterlist *sgl, unsigned int sgc)
{
        struct net_device *netdev = fcoe_netdev(lport);

        if (netdev->netdev_ops->ndo_fcoe_ddp_setup)
                return netdev->netdev_ops->ndo_fcoe_ddp_setup(netdev,
                                                              xid, sgl,
                                                              sgc);

        return 0;
}

/**
 * fcoe_ddp_done() - Call a LLD's ddp_done through the net device
 * @lport: The local port to complete DDP on
 * @xid:   The exchange ID for this DDP transfer
 *
 * Returns: the length of data that have been completed by DDP
 */
static int fcoe_ddp_done(struct fc_lport *lport, u16 xid)
{
        struct net_device *netdev = fcoe_netdev(lport);

        if (netdev->netdev_ops->ndo_fcoe_ddp_done)
                return netdev->netdev_ops->ndo_fcoe_ddp_done(netdev, xid);
        return 0;
}

/**
 * fcoe_if_create() - Create a FCoE instance on an interface
 * @fcoe:   The FCoE interface to create a local port on
 * @parent: The device pointer to be the parent in sysfs for the SCSI host
 * @npiv:   Indicates if the port is a vport or not
 *
 * Creates a fc_lport instance and a Scsi_Host instance and configure them.
 *
 * Returns: The allocated fc_lport or an error pointer
 */
static struct fc_lport *fcoe_if_create(struct fcoe_interface *fcoe,
                                       struct device *parent, int npiv)
{
        struct net_device *netdev = fcoe->netdev;
        struct fc_lport *lport = NULL;
        struct fcoe_port *port;
        struct Scsi_Host *shost;
        int rc;
        /*
         * parent is only a vport if npiv is 1,
         * but we'll only use vport in that case so go ahead and set it
         */
        struct fc_vport *vport = dev_to_vport(parent);

        FCOE_NETDEV_DBG(netdev, "Create Interface\n");

        if (!npiv) {
                lport = libfc_host_alloc(&fcoe_shost_template,
                                         sizeof(struct fcoe_port));
        } else  {
                lport = libfc_vport_create(vport,
                                           sizeof(struct fcoe_port));
        }
        if (!lport) {
                FCOE_NETDEV_DBG(netdev, "Could not allocate host structure\n");
                rc = -ENOMEM;
                goto out;
        }
        shost = lport->host;
        port = lport_priv(lport);
        port->lport = lport;
        port->fcoe = fcoe;
        INIT_WORK(&port->destroy_work, fcoe_destroy_work);

        /* configure a fc_lport including the exchange manager */
        rc = fcoe_lport_config(lport);
        if (rc) {
                FCOE_NETDEV_DBG(netdev, "Could not configure lport for the "
                                "interface\n");
                goto out_host_put;
        }

        if (npiv) {
                FCOE_NETDEV_DBG(netdev, "Setting vport names, 0x%llX 0x%llX\n",
                                vport->node_name, vport->port_name);
                fc_set_wwnn(lport, vport->node_name);
                fc_set_wwpn(lport, vport->port_name);
        }

        /* configure lport network properties */
        rc = fcoe_netdev_config(lport, netdev);
        if (rc) {
                FCOE_NETDEV_DBG(netdev, "Could not configure netdev for the "
                                "interface\n");
                goto out_lp_destroy;
        }

        /* configure lport scsi host properties */
        rc = fcoe_shost_config(lport, shost, parent);
        if (rc) {
                FCOE_NETDEV_DBG(netdev, "Could not configure shost for the "
                                "interface\n");
                goto out_lp_destroy;
        }

        /* Initialize the library */
        rc = fcoe_libfc_config(lport, &fcoe_libfc_fcn_templ);
        if (rc) {
                FCOE_NETDEV_DBG(netdev, "Could not configure libfc for the "
                                "interface\n");
                goto out_lp_destroy;
        }

        if (!npiv) {
                /*
                 * fcoe_em_alloc() and fcoe_hostlist_add() both
                 * need to be atomic with respect to other changes to the
                 * hostlist since fcoe_em_alloc() looks for an existing EM
                 * instance on host list updated by fcoe_hostlist_add().
                 *
                 * This is currently handled through the fcoe_config_mutex
                 * begin held.
                 */

                /* lport exch manager allocation */
                rc = fcoe_em_config(lport);
                if (rc) {
                        FCOE_NETDEV_DBG(netdev, "Could not configure the EM "
                                        "for the interface\n");
                        goto out_lp_destroy;
                }
        }

        fcoe_interface_get(fcoe);
        return lport;

out_lp_destroy:
        fc_exch_mgr_free(lport);
out_host_put:
        scsi_host_put(lport->host);
out:
        return ERR_PTR(rc);
}

/**
 * fcoe_if_init() - Initialization routine for fcoe.ko
 *
 * Attaches the SW FCoE transport to the FC transport
 *
 * Returns: 0 on success
 */
static int __init fcoe_if_init(void)
{
        /* attach to scsi transport */
        fcoe_transport_template = fc_attach_transport(&fcoe_transport_function);
        fcoe_vport_transport_template =
                fc_attach_transport(&fcoe_vport_transport_function);

        if (!fcoe_transport_template) {
                printk(KERN_ERR "fcoe: Failed to attach to the FC transport\n");
                return -ENODEV;
        }

        return 0;
}

/**
 * fcoe_if_exit() - Tear down fcoe.ko
 *
 * Detaches the SW FCoE transport from the FC transport
 *
 * Returns: 0 on success
 */
int __exit fcoe_if_exit(void)
{
        fc_release_transport(fcoe_transport_template);
        fc_release_transport(fcoe_vport_transport_template);
        fcoe_transport_template = NULL;
        fcoe_vport_transport_template = NULL;
        return 0;
}

/**
 * fcoe_percpu_thread_create() - Create a receive thread for an online CPU
 * @cpu: The CPU index of the CPU to create a receive thread for
 */
static void fcoe_percpu_thread_create(unsigned int cpu)
{
        struct fcoe_percpu_s *p;
        struct task_struct *thread;

        p = &per_cpu(fcoe_percpu, cpu);

        thread = kthread_create(fcoe_percpu_receive_thread,
                                (void *)p, "fcoethread/%d", cpu);

        if (likely(!IS_ERR(thread))) {
                kthread_bind(thread, cpu);
                wake_up_process(thread);

                spin_lock_bh(&p->fcoe_rx_list.lock);
                p->thread = thread;
                spin_unlock_bh(&p->fcoe_rx_list.lock);
        }
}

/**
 * fcoe_percpu_thread_destroy() - Remove the receive thread of a CPU
 * @cpu: The CPU index of the CPU whose receive thread is to be destroyed
 *
 * Destroys a per-CPU Rx thread. Any pending skbs are moved to the
 * current CPU's Rx thread. If the thread being destroyed is bound to
 * the CPU processing this context the skbs will be freed.
 */
static void fcoe_percpu_thread_destroy(unsigned int cpu)
{
        struct fcoe_percpu_s *p;
        struct task_struct *thread;
        struct page *crc_eof;
        struct sk_buff *skb;
#ifdef CONFIG_SMP
        struct fcoe_percpu_s *p0;
        unsigned targ_cpu = smp_processor_id();
#endif /* CONFIG_SMP */

        FCOE_DBG("Destroying receive thread for CPU %d\n", cpu);

        /* Prevent any new skbs from being queued for this CPU. */
        p = &per_cpu(fcoe_percpu, cpu);
        spin_lock_bh(&p->fcoe_rx_list.lock);
        thread = p->thread;
        p->thread = NULL;
        crc_eof = p->crc_eof_page;
        p->crc_eof_page = NULL;
        p->crc_eof_offset = 0;
        spin_unlock_bh(&p->fcoe_rx_list.lock);

#ifdef CONFIG_SMP
        /*
         * Don't bother moving the skb's if this context is running
         * on the same CPU that is having its thread destroyed. This
         * can easily happen when the module is removed.
         */
        if (cpu != targ_cpu) {
                p0 = &per_cpu(fcoe_percpu, targ_cpu);
                spin_lock_bh(&p0->fcoe_rx_list.lock);
                if (p0->thread) {
                        FCOE_DBG("Moving frames from CPU %d to CPU %d\n",
                                 cpu, targ_cpu);

                        while ((skb = __skb_dequeue(&p->fcoe_rx_list)) != NULL)
                                __skb_queue_tail(&p0->fcoe_rx_list, skb);
                        spin_unlock_bh(&p0->fcoe_rx_list.lock);
                } else {
                        /*
                         * The targeted CPU is not initialized and cannot accept
                         * new  skbs. Unlock the targeted CPU and drop the skbs
                         * on the CPU that is going offline.
                         */
                        while ((skb = __skb_dequeue(&p->fcoe_rx_list)) != NULL)
                                kfree_skb(skb);
                        spin_unlock_bh(&p0->fcoe_rx_list.lock);
                }
        } else {
                /*
                 * This scenario occurs when the module is being removed
                 * and all threads are being destroyed. skbs will continue
                 * to be shifted from the CPU thread that is being removed
                 * to the CPU thread associated with the CPU that is processing
                 * the module removal. Once there is only one CPU Rx thread it
                 * will reach this case and we will drop all skbs and later
                 * stop the thread.
                 */
                spin_lock_bh(&p->fcoe_rx_list.lock);
                while ((skb = __skb_dequeue(&p->fcoe_rx_list)) != NULL)
                        kfree_skb(skb);
                spin_unlock_bh(&p->fcoe_rx_list.lock);
        }
#else
        /*
         * This a non-SMP scenario where the singular Rx thread is
         * being removed. Free all skbs and stop the thread.
         */
        spin_lock_bh(&p->fcoe_rx_list.lock);
        while ((skb = __skb_dequeue(&p->fcoe_rx_list)) != NULL)
                kfree_skb(skb);
        spin_unlock_bh(&p->fcoe_rx_list.lock);
#endif

        if (thread)
                kthread_stop(thread);

        if (crc_eof)
                put_page(crc_eof);
}

/**
 * fcoe_cpu_callback() - Handler for CPU hotplug events
 * @nfb:    The callback data block
 * @action: The event triggering the callback
 * @hcpu:   The index of the CPU that the event is for
 *
 * This creates or destroys per-CPU data for fcoe
 *
 * Returns NOTIFY_OK always.
 */
static int fcoe_cpu_callback(struct notifier_block *nfb,
                             unsigned long action, void *hcpu)
{
        unsigned cpu = (unsigned long)hcpu;

        switch (action) {
        case CPU_ONLINE:
        case CPU_ONLINE_FROZEN:
                FCOE_DBG("CPU %x online: Create Rx thread\n", cpu);
                fcoe_percpu_thread_create(cpu);
                break;
        case CPU_DEAD:
        case CPU_DEAD_FROZEN:
                FCOE_DBG("CPU %x offline: Remove Rx thread\n", cpu);
                fcoe_percpu_thread_destroy(cpu);
                break;
        default:
                break;
        }
        return NOTIFY_OK;
}

/**
 * fcoe_rcv() - Receive packets from a net device
 * @skb:    The received packet
 * @netdev: The net device that the packet was received on
 * @ptype:  The packet type context
 * @olddev: The last device net device
 *
 * This routine is called by NET_RX_SOFTIRQ. It receives a packet, builds a
 * FC frame and passes the frame to libfc.
 *
 * Returns: 0 for success
 */
int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev,
             struct packet_type *ptype, struct net_device *olddev)
{
        struct fc_lport *lport;
        struct fcoe_rcv_info *fr;
        struct fcoe_interface *fcoe;
        struct fc_frame_header *fh;
        struct fcoe_percpu_s *fps;
        unsigned int cpu;

        fcoe = container_of(ptype, struct fcoe_interface, fcoe_packet_type);
        lport = fcoe->ctlr.lp;
        if (unlikely(!lport)) {
                FCOE_NETDEV_DBG(netdev, "Cannot find hba structure");
                goto err2;
        }
        if (!lport->link_up)
                goto err2;

        FCOE_NETDEV_DBG(netdev, "skb_info: len:%d data_len:%d head:%p "
                        "data:%p tail:%p end:%p sum:%d dev:%s",
                        skb->len, skb->data_len, skb->head, skb->data,
                        skb_tail_pointer(skb), skb_end_pointer(skb),
                        skb->csum, skb->dev ? skb->dev->name : "<NULL>");

        /* check for FCOE packet type */
        if (unlikely(eth_hdr(skb)->h_proto != htons(ETH_P_FCOE))) {
                FCOE_NETDEV_DBG(netdev, "Wrong FC type frame");
                goto err;
        }

        /*
         * Check for minimum frame length, and make sure required FCoE
         * and FC headers are pulled into the linear data area.
         */
        if (unlikely((skb->len < FCOE_MIN_FRAME) ||
                     !pskb_may_pull(skb, FCOE_HEADER_LEN)))
                goto err;

        skb_set_transport_header(skb, sizeof(struct fcoe_hdr));
        fh = (struct fc_frame_header *) skb_transport_header(skb);

        fr = fcoe_dev_from_skb(skb);
        fr->fr_dev = lport;
        fr->ptype = ptype;

        /*
         * In case the incoming frame's exchange is originated from
         * the initiator, then received frame's exchange id is ANDed
         * with fc_cpu_mask bits to get the same cpu on which exchange
         * was originated, otherwise just use the current cpu.
         */
        if (ntoh24(fh->fh_f_ctl) & FC_FC_EX_CTX)
                cpu = ntohs(fh->fh_ox_id) & fc_cpu_mask;
        else
                cpu = smp_processor_id();

        fps = &per_cpu(fcoe_percpu, cpu);
        spin_lock_bh(&fps->fcoe_rx_list.lock);
        if (unlikely(!fps->thread)) {
                /*
                 * The targeted CPU is not ready, let's target
                 * the first CPU now. For non-SMP systems this
                 * will check the same CPU twice.
                 */
                FCOE_NETDEV_DBG(netdev, "CPU is online, but no receive thread "
                                "ready for incoming skb- using first online "
                                "CPU.\n");

                spin_unlock_bh(&fps->fcoe_rx_list.lock);
                cpu = first_cpu(cpu_online_map);
                fps = &per_cpu(fcoe_percpu, cpu);
                spin_lock_bh(&fps->fcoe_rx_list.lock);
                if (!fps->thread) {
                        spin_unlock_bh(&fps->fcoe_rx_list.lock);
                        goto err;
                }
        }

        /*
         * We now have a valid CPU that we're targeting for
         * this skb. We also have this receive thread locked,
         * so we're free to queue skbs into it's queue.
         */

        /* If this is a SCSI-FCP frame, and this is already executing on the
         * correct CPU, and the queue for this CPU is empty, then go ahead
         * and process the frame directly in the softirq context.
         * This lets us process completions without context switching from the
         * NET_RX softirq, to our receive processing thread, and then back to
         * BLOCK softirq context.
         */
        if (fh->fh_type == FC_TYPE_FCP &&
            cpu == smp_processor_id() &&
            skb_queue_empty(&fps->fcoe_rx_list)) {
                spin_unlock_bh(&fps->fcoe_rx_list.lock);
                fcoe_recv_frame(skb);
        } else {
                __skb_queue_tail(&fps->fcoe_rx_list, skb);
                if (fps->fcoe_rx_list.qlen == 1)
                        wake_up_process(fps->thread);
                spin_unlock_bh(&fps->fcoe_rx_list.lock);
        }

        return 0;
err:
        fc_lport_get_stats(lport)->ErrorFrames++;

err2:
        kfree_skb(skb);
        return -1;
}

/**
 * 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
 */
static inline int fcoe_start_io(struct sk_buff *skb)
{
        struct sk_buff *nskb;
        int rc;

        nskb = skb_clone(skb, GFP_ATOMIC);
        rc = dev_queue_xmit(nskb);
        if (rc != 0)
                return rc;
        kfree_skb(skb);
        return 0;
}

/**
 * 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
 *
 * 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
 */
static int fcoe_get_paged_crc_eof(struct sk_buff *skb, int tlen)
{
        struct fcoe_percpu_s *fps;
        struct page *page;

        fps = &get_cpu_var(fcoe_percpu);
        page = fps->crc_eof_page;
        if (!page) {
                page = alloc_page(GFP_ATOMIC);
                if (!page) {
                        put_cpu_var(fcoe_percpu);
                        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);
        }
        put_cpu_var(fcoe_percpu);
        return 0;
}

/**
 * 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 = frag->size;
                while (len > 0) {
                        clen = min(len, PAGE_SIZE - (off & ~PAGE_MASK));
                        data = kmap_atomic(frag->page + (off >> PAGE_SHIFT),
                                           KM_SKB_DATA_SOFTIRQ);
                        crc = crc32(crc, data + (off & ~PAGE_MASK), clen);
                        kunmap_atomic(data, KM_SKB_DATA_SOFTIRQ);
                        off += clen;
                        len -= clen;
                }
        }
        return crc;
}

/**
 * fcoe_xmit() - Transmit a FCoE frame
 * @lport: The local port that the frame is to be transmitted for
 * @fp:    The frame to be transmitted
 *
 * Return: 0 for success
 */
int fcoe_xmit(struct fc_lport *lport, struct fc_frame *fp)
{
        int wlen;
        u32 crc;
        struct ethhdr *eh;
        struct fcoe_crc_eof *cp;
        struct sk_buff *skb;
        struct fcoe_dev_stats *stats;
        struct fc_frame_header *fh;
        unsigned int hlen;              /* header length implies the version */
        unsigned int tlen;              /* trailer length */
        unsigned int elen;              /* eth header, may include vlan */
        struct fcoe_port *port = lport_priv(lport);
        struct fcoe_interface *fcoe = port->fcoe;
        u8 sof, eof;
        struct fcoe_hdr *hp;

        WARN_ON((fr_len(fp) % sizeof(u32)) != 0);

        fh = fc_frame_header_get(fp);
        skb = fp_skb(fp);
        wlen = skb->len / FCOE_WORD_TO_BYTE;

        if (!lport->link_up) {
                kfree_skb(skb);
                return 0;
        }

        if (unlikely(fh->fh_r_ctl == FC_RCTL_ELS_REQ) &&
            fcoe_ctlr_els_send(&fcoe->ctlr, lport, skb))
                return 0;

        sof = fr_sof(fp);
        eof = fr_eof(fp);

        elen = sizeof(struct ethhdr);
        hlen = sizeof(struct fcoe_hdr);
        tlen = sizeof(struct fcoe_crc_eof);
        wlen = (skb->len - tlen + sizeof(crc)) / FCOE_WORD_TO_BYTE;

        /* crc offload */
        if (likely(lport->crc_offload)) {
                skb->ip_summed = CHECKSUM_PARTIAL;
                skb->csum_start = skb_headroom(skb);
                skb->csum_offset = skb->len;
                crc = 0;
        } else {
                skb->ip_summed = CHECKSUM_NONE;
                crc = fcoe_fc_crc(fp);
        }

        /* copy port crc and eof to the skb buff */
        if (skb_is_nonlinear(skb)) {
                skb_frag_t *frag;
                if (fcoe_get_paged_crc_eof(skb, tlen)) {
                        kfree_skb(skb);
                        return -ENOMEM;
                }
                frag = &skb_shinfo(skb)->frags[skb_shinfo(skb)->nr_frags - 1];
                cp = kmap_atomic(frag->page, KM_SKB_DATA_SOFTIRQ)
                        + frag->page_offset;
        } else {
                cp = (struct fcoe_crc_eof *)skb_put(skb, tlen);
        }

        memset(cp, 0, sizeof(*cp));
        cp->fcoe_eof = eof;
        cp->fcoe_crc32 = cpu_to_le32(~crc);

        if (skb_is_nonlinear(skb)) {
                kunmap_atomic(cp, KM_SKB_DATA_SOFTIRQ);
                cp = NULL;
        }

        /* adjust skb network/transport offsets to match mac/fcoe/port */
        skb_push(skb, elen + hlen);
        skb_reset_mac_header(skb);
        skb_reset_network_header(skb);
        skb->mac_len = elen;
        skb->protocol = htons(ETH_P_FCOE);
        skb->dev = fcoe->netdev;

        /* fill up mac and fcoe headers */
        eh = eth_hdr(skb);
        eh->h_proto = htons(ETH_P_FCOE);
        if (fcoe->ctlr.map_dest)
                fc_fcoe_set_mac(eh->h_dest, fh->fh_d_id);
        else
                /* insert GW address */
                memcpy(eh->h_dest, fcoe->ctlr.dest_addr, ETH_ALEN);

        if (unlikely(fcoe->ctlr.flogi_oxid != FC_XID_UNKNOWN))
                memcpy(eh->h_source, fcoe->ctlr.ctl_src_addr, ETH_ALEN);
        else
                memcpy(eh->h_source, port->data_src_addr, ETH_ALEN);

        hp = (struct fcoe_hdr *)(eh + 1);
        memset(hp, 0, sizeof(*hp));
        if (FC_FCOE_VER)
                FC_FCOE_ENCAPS_VER(hp, FC_FCOE_VER);
        hp->fcoe_sof = sof;

        /* fcoe lso, mss is in max_payload which is non-zero for FCP data */
        if (lport->seq_offload && fr_max_payload(fp)) {
                skb_shinfo(skb)->gso_type = SKB_GSO_FCOE;
                skb_shinfo(skb)->gso_size = fr_max_payload(fp);
        } else {
                skb_shinfo(skb)->gso_type = 0;
                skb_shinfo(skb)->gso_size = 0;
        }
        /* update tx stats: regardless if LLD fails */
        stats = fc_lport_get_stats(lport);
        stats->TxFrames++;
        stats->TxWords += wlen;

        /* send down to lld */
        fr_dev(fp) = lport;
        if (port->fcoe_pending_queue.qlen)
                fcoe_check_wait_queue(lport, skb);
        else if (fcoe_start_io(skb))
                fcoe_check_wait_queue(lport, skb);

        return 0;
}

/**
 * fcoe_percpu_flush_done() - Indicate per-CPU queue flush completion
 * @skb: The completed skb (argument required by destructor)
 */
static void fcoe_percpu_flush_done(struct sk_buff *skb)
{
        complete(&fcoe_flush_completion);
}

/**
 * fcoe_recv_frame() - process a single received frame
 * @skb: frame to process
 */
static void fcoe_recv_frame(struct sk_buff *skb)
{
        u32 fr_len;
        struct fc_lport *lport;
        struct fcoe_rcv_info *fr;
        struct fcoe_dev_stats *stats;
        struct fc_frame_header *fh;
        struct fcoe_crc_eof crc_eof;
        struct fc_frame *fp;
        u8 *mac = NULL;
        struct fcoe_port *port;
        struct fcoe_hdr *hp;

        fr = fcoe_dev_from_skb(skb);
        lport = fr->fr_dev;
        if (unlikely(!lport)) {
                if (skb->destructor != fcoe_percpu_flush_done)
                        FCOE_NETDEV_DBG(skb->dev, "NULL lport in skb");
                kfree_skb(skb);
                return;
        }

        FCOE_NETDEV_DBG(skb->dev, "skb_info: len:%d data_len:%d "
                        "head:%p data:%p tail:%p end:%p sum:%d dev:%s",
                        skb->len, skb->data_len,
                        skb->head, skb->data, skb_tail_pointer(skb),
                        skb_end_pointer(skb), skb->csum,
                        skb->dev ? skb->dev->name : "<NULL>");

        /*
         * Save source MAC address before discarding header.
         */
        port = lport_priv(lport);
        if (skb_is_nonlinear(skb))
                skb_linearize(skb);     /* not ideal */
        mac = eth_hdr(skb)->h_source;

        /*
         * Frame length checks and setting up the header pointers
         * was done in fcoe_rcv already.
         */
        hp = (struct fcoe_hdr *) skb_network_header(skb);
        fh = (struct fc_frame_header *) skb_transport_header(skb);

        stats = fc_lport_get_stats(lport);
        if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
                if (stats->ErrorFrames < 5)
                        printk(KERN_WARNING "fcoe: FCoE version "
                               "mismatch: The frame has "
                               "version %x, but the "
                               "initiator supports version "
                               "%x\n", FC_FCOE_DECAPS_VER(hp),
                               FC_FCOE_VER);
                stats->ErrorFrames++;
                kfree_skb(skb);
                return;
        }

        skb_pull(skb, sizeof(struct fcoe_hdr));
        fr_len = skb->len - sizeof(struct fcoe_crc_eof);

        stats->RxFrames++;
        stats->RxWords += fr_len / FCOE_WORD_TO_BYTE;

        fp = (struct fc_frame *)skb;
        fc_frame_init(fp);
        fr_dev(fp) = lport;
        fr_sof(fp) = hp->fcoe_sof;

        /* Copy out the CRC and EOF trailer for access */
        if (skb_copy_bits(skb, fr_len, &crc_eof, sizeof(crc_eof))) {
                kfree_skb(skb);
                return;
        }
        fr_eof(fp) = crc_eof.fcoe_eof;
        fr_crc(fp) = crc_eof.fcoe_crc32;
        if (pskb_trim(skb, fr_len)) {
                kfree_skb(skb);
                return;
        }

        /*
         * We only check CRC if no offload is available and if it is
         * it's solicited data, in which case, the FCP layer would
         * check it during the copy.
         */
        if (lport->crc_offload &&
            skb->ip_summed == CHECKSUM_UNNECESSARY)
                fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
        else
                fr_flags(fp) |= FCPHF_CRC_UNCHECKED;

        fh = fc_frame_header_get(fp);
        if (fh->fh_r_ctl == FC_RCTL_DD_SOL_DATA &&
            fh->fh_type == FC_TYPE_FCP) {
                fc_exch_recv(lport, fp);
                return;
        }
        if (fr_flags(fp) & FCPHF_CRC_UNCHECKED) {
                if (le32_to_cpu(fr_crc(fp)) !=
                    ~crc32(~0, skb->data, fr_len)) {
                        if (stats->InvalidCRCCount < 5)
                                printk(KERN_WARNING "fcoe: dropping "
                                       "frame with CRC error\n");
                        stats->InvalidCRCCount++;
                        stats->ErrorFrames++;
                        fc_frame_free(fp);
                        return;
                }
                fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
        }
        fc_exch_recv(lport, fp);
}

/**
 * fcoe_percpu_receive_thread() - The per-CPU packet receive thread
 * @arg: The per-CPU context
 *
 * Return: 0 for success
 */
int fcoe_percpu_receive_thread(void *arg)
{
        struct fcoe_percpu_s *p = arg;
        struct sk_buff *skb;

        set_user_nice(current, -20);

        while (!kthread_should_stop()) {

                spin_lock_bh(&p->fcoe_rx_list.lock);
                while ((skb = __skb_dequeue(&p->fcoe_rx_list)) == NULL) {
                        set_current_state(TASK_INTERRUPTIBLE);
                        spin_unlock_bh(&p->fcoe_rx_list.lock);
                        schedule();
                        set_current_state(TASK_RUNNING);
                        if (kthread_should_stop())
                                return 0;
                        spin_lock_bh(&p->fcoe_rx_list.lock);
                }
                spin_unlock_bh(&p->fcoe_rx_list.lock);
                fcoe_recv_frame(skb);
        }
        return 0;
}

/**
 * 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.
 */
static 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 < FCOE_LOW_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 > FCOE_MAX_QUEUE_DEPTH)
                lport->qfull = 1;
        spin_unlock_bh(&port->fcoe_pending_queue.lock);
        return;
}

/**
 * fcoe_dev_setup() - Setup the link change notification interface
 */
static void fcoe_dev_setup(void)
{
        register_netdevice_notifier(&fcoe_notifier);
}

/**
 * fcoe_dev_cleanup() - Cleanup the link change notification interface
 */
static void fcoe_dev_cleanup(void)
{
        unregister_netdevice_notifier(&fcoe_notifier);
}

/**
 * fcoe_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 fcoe_device_notification(struct notifier_block *notifier,
                                    ulong event, void *ptr)
{
        struct fc_lport *lport = NULL;
        struct net_device *netdev = ptr;
        struct fcoe_interface *fcoe;
        struct fcoe_port *port;
        struct fcoe_dev_stats *stats;
        u32 link_possible = 1;
        u32 mfs;
        int rc = NOTIFY_OK;

        list_for_each_entry(fcoe, &fcoe_hostlist, list) {
                if (fcoe->netdev == netdev) {
                        lport = fcoe->ctlr.lp;
                        break;
                }
        }
        if (!lport) {
                rc = NOTIFY_DONE;
                goto out;
        }

        switch (event) {
        case NETDEV_DOWN:
        case NETDEV_GOING_DOWN:
                link_possible = 0;
                break;
        case NETDEV_UP:
        case NETDEV_CHANGE:
                break;
        case NETDEV_CHANGEMTU:
                if (netdev->features & NETIF_F_FCOE_MTU)
                        break;
                mfs = netdev->mtu - (sizeof(struct fcoe_hdr) +
                                     sizeof(struct fcoe_crc_eof));
                if (mfs >= FC_MIN_MAX_FRAME)
                        fc_set_mfs(lport, mfs);
                break;
        case NETDEV_REGISTER:
                break;
        case NETDEV_UNREGISTER:
                list_del(&fcoe->list);
                port = lport_priv(fcoe->ctlr.lp);
                fcoe_interface_cleanup(fcoe);
                schedule_work(&port->destroy_work);
                goto out;
                break;
        default:
                FCOE_NETDEV_DBG(netdev, "Unknown event %ld "
                                "from netdev netlink\n", event);
        }
        if (link_possible && !fcoe_link_ok(lport))
                fcoe_ctlr_link_up(&fcoe->ctlr);
        else if (fcoe_ctlr_link_down(&fcoe->ctlr)) {
                stats = fc_lport_get_stats(lport);
                stats->LinkFailureCount++;
                fcoe_clean_pending_queue(lport);
        }
out:
        return rc;
}

/**
 * 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;
}

/**
 * fcoe_destroy() - Destroy a FCoE interface
 * @buffer: The name of the Ethernet interface to be destroyed
 * @kp:     The associated kernel parameter
 *
 * Called from sysfs.
 *
 * Returns: 0 for success
 */
static int fcoe_destroy(const char *buffer, struct kernel_param *kp)
{
        struct fcoe_interface *fcoe;
        struct net_device *netdev;
        int rc = 0;

        mutex_lock(&fcoe_config_mutex);
#ifdef CONFIG_FCOE_MODULE
        /*
         * Make sure the module has been initialized, and is not about to be
         * removed.  Module paramter sysfs files are writable before the
         * module_init function is called and after module_exit.
         */
        if (THIS_MODULE->state != MODULE_STATE_LIVE) {
                rc = -ENODEV;
                goto out_nodev;
        }
#endif

        netdev = fcoe_if_to_netdev(buffer);
        if (!netdev) {
                rc = -ENODEV;
                goto out_nodev;
        }

        rtnl_lock();
        fcoe = fcoe_hostlist_lookup_port(netdev);
        if (!fcoe) {
                rtnl_unlock();
                rc = -ENODEV;
                goto out_putdev;
        }
        list_del(&fcoe->list);
        fcoe_interface_cleanup(fcoe);
        rtnl_unlock();
        fcoe_if_destroy(fcoe->ctlr.lp);
out_putdev:
        dev_put(netdev);
out_nodev:
        mutex_unlock(&fcoe_config_mutex);
        return rc;
}

/**
 * fcoe_destroy_work() - Destroy a FCoE port in a deferred work context
 * @work: Handle to the FCoE port to be destroyed
 */
static void fcoe_destroy_work(struct work_struct *work)
{
        struct fcoe_port *port;

        port = container_of(work, struct fcoe_port, destroy_work);
        mutex_lock(&fcoe_config_mutex);
        fcoe_if_destroy(port->lport);
        mutex_unlock(&fcoe_config_mutex);
}

/**
 * fcoe_create() - Create a fcoe interface
 * @buffer: The name of the Ethernet interface to create on
 * @kp:     The associated kernel param
 *
 * Called from sysfs.
 *
 * Returns: 0 for success
 */
static int fcoe_create(const char *buffer, struct kernel_param *kp)
{
        int rc;
        struct fcoe_interface *fcoe;
        struct fc_lport *lport;
        struct net_device *netdev;

        mutex_lock(&fcoe_config_mutex);
#ifdef CONFIG_FCOE_MODULE
        /*
         * Make sure the module has been initialized, and is not about to be
         * removed.  Module paramter sysfs files are writable before the
         * module_init function is called and after module_exit.
         */
        if (THIS_MODULE->state != MODULE_STATE_LIVE) {
                rc = -ENODEV;
                goto out_nodev;
        }
#endif

        rtnl_lock();
        netdev = fcoe_if_to_netdev(buffer);
        if (!netdev) {
                rc = -ENODEV;
                goto out_nodev;
        }

        /* look for existing lport */
        if (fcoe_hostlist_lookup(netdev)) {
                rc = -EEXIST;
                goto out_putdev;
        }

        fcoe = fcoe_interface_create(netdev);
        if (!fcoe) {
                rc = -ENOMEM;
                goto out_putdev;
        }

        lport = fcoe_if_create(fcoe, &netdev->dev, 0);
        if (IS_ERR(lport)) {
                printk(KERN_ERR "fcoe: Failed to create interface (%s)\n",
                       netdev->name);
                rc = -EIO;
                fcoe_interface_cleanup(fcoe);
                goto out_free;
        }

        /* Make this the "master" N_Port */
        fcoe->ctlr.lp = lport;

        /* add to lports list */
        fcoe_hostlist_add(lport);

        /* start FIP Discovery and FLOGI */
        lport->boot_time = jiffies;
        fc_fabric_login(lport);
        if (!fcoe_link_ok(lport))
                fcoe_ctlr_link_up(&fcoe->ctlr);

        rc = 0;
out_free:
        /*
         * Release from init in fcoe_interface_create(), on success lport
         * should be holding a reference taken in fcoe_if_create().
         */
        fcoe_interface_put(fcoe);
out_putdev:
        dev_put(netdev);
out_nodev:
        rtnl_unlock();
        mutex_unlock(&fcoe_config_mutex);
        return rc;
}

/**
 * fcoe_link_ok() - Check if the link is OK for a local port
 * @lport: The local port to check link on
 *
 * Any permanently-disqualifying conditions have been previously checked.
 * This also updates the speed setting, which may change with link for 100/1000.
 *
 * This function should probably be checking for PAUSE support at some point
 * in the future. Currently Per-priority-pause is not determinable using
 * ethtool, so we shouldn't be restrictive until that problem is resolved.
 *
 * Returns: 0 if link is OK for use by FCoE.
 *
 */
int fcoe_link_ok(struct fc_lport *lport)
{
        struct fcoe_port *port = lport_priv(lport);
        struct net_device *netdev = port->fcoe->netdev;
        struct ethtool_cmd ecmd = { ETHTOOL_GSET };

        if ((netdev->flags & IFF_UP) && netif_carrier_ok(netdev) &&
            (!dev_ethtool_get_settings(netdev, &ecmd))) {
                lport->link_supported_speeds &=
                        ~(FC_PORTSPEED_1GBIT | FC_PORTSPEED_10GBIT);
                if (ecmd.supported & (SUPPORTED_1000baseT_Half |
                                      SUPPORTED_1000baseT_Full))
                        lport->link_supported_speeds |= FC_PORTSPEED_1GBIT;
                if (ecmd.supported & SUPPORTED_10000baseT_Full)
                        lport->link_supported_speeds |=
                                FC_PORTSPEED_10GBIT;
                if (ecmd.speed == SPEED_1000)
                        lport->link_speed = FC_PORTSPEED_1GBIT;
                if (ecmd.speed == SPEED_10000)
                        lport->link_speed = FC_PORTSPEED_10GBIT;

                return 0;
        }
        return -1;
}

/**
 * fcoe_percpu_clean() - Clear all pending skbs for an local port
 * @lport: The local port whose skbs are to be cleared
 *
 * Must be called with fcoe_create_mutex held to single-thread completion.
 *
 * This flushes the pending skbs by adding a new skb to each queue and
 * waiting until they are all freed.  This assures us that not only are
 * there no packets that will be handled by the lport, but also that any
 * threads already handling packet have returned.
 */
void fcoe_percpu_clean(struct fc_lport *lport)
{
        struct fcoe_percpu_s *pp;
        struct fcoe_rcv_info *fr;
        struct sk_buff_head *list;
        struct sk_buff *skb, *next;
        struct sk_buff *head;
        unsigned int cpu;

        for_each_possible_cpu(cpu) {
                pp = &per_cpu(fcoe_percpu, cpu);
                spin_lock_bh(&pp->fcoe_rx_list.lock);
                list = &pp->fcoe_rx_list;
                head = list->next;
                for (skb = head; skb != (struct sk_buff *)list;
                     skb = next) {
                        next = skb->next;
                        fr = fcoe_dev_from_skb(skb);
                        if (fr->fr_dev == lport) {
                                __skb_unlink(skb, list);
                                kfree_skb(skb);
                        }
                }

                if (!pp->thread || !cpu_online(cpu)) {
                        spin_unlock_bh(&pp->fcoe_rx_list.lock);
                        continue;
                }

                skb = dev_alloc_skb(0);
                if (!skb) {
                        spin_unlock_bh(&pp->fcoe_rx_list.lock);
                        continue;
                }
                skb->destructor = fcoe_percpu_flush_done;

                __skb_queue_tail(&pp->fcoe_rx_list, skb);
                if (pp->fcoe_rx_list.qlen == 1)
                        wake_up_process(pp->thread);
                spin_unlock_bh(&pp->fcoe_rx_list.lock);

                wait_for_completion(&fcoe_flush_completion);
        }
}

/**
 * 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);
}

/**
 * fcoe_reset() - Reset a local port
 * @shost: The SCSI host associated with the local port to be reset
 *
 * Returns: Always 0 (return value required by FC transport template)
 */
int fcoe_reset(struct Scsi_Host *shost)
{
        struct fc_lport *lport = shost_priv(shost);
        fc_lport_reset(lport);
        return 0;
}

/**
 * fcoe_hostlist_lookup_port() - Find the FCoE interface associated with a net device
 * @netdev: The net device used as a key
 *
 * Locking: Must be called with the RNL mutex held.
 *
 * Returns: NULL or the FCoE interface
 */
static struct fcoe_interface *
fcoe_hostlist_lookup_port(const struct net_device *netdev)
{
        struct fcoe_interface *fcoe;

        list_for_each_entry(fcoe, &fcoe_hostlist, list) {
                if (fcoe->netdev == netdev)
                        return fcoe;
        }
        return NULL;
}

/**
 * fcoe_hostlist_lookup() - Find the local port associated with a
 *                          given net device
 * @netdev: The netdevice used as a key
 *
 * Locking: Must be called with the RTNL mutex held
 *
 * Returns: NULL or the local port
 */
static struct fc_lport *fcoe_hostlist_lookup(const struct net_device *netdev)
{
        struct fcoe_interface *fcoe;

        fcoe = fcoe_hostlist_lookup_port(netdev);
        return (fcoe) ? fcoe->ctlr.lp : NULL;
}

/**
 * fcoe_hostlist_add() - Add the FCoE interface identified by a local
 *                       port to the hostlist
 * @lport: The local port that identifies the FCoE interface to be added
 *
 * Locking: must be called with the RTNL mutex held
 *
 * Returns: 0 for success
 */
static int fcoe_hostlist_add(const struct fc_lport *lport)
{
        struct fcoe_interface *fcoe;
        struct fcoe_port *port;

        fcoe = fcoe_hostlist_lookup_port(fcoe_netdev(lport));
        if (!fcoe) {
                port = lport_priv(lport);
                fcoe = port->fcoe;
                list_add_tail(&fcoe->list, &fcoe_hostlist);
        }
        return 0;
}

/**
 * fcoe_init() - Initialize fcoe.ko
 *
 * Returns: 0 on success, or a negative value on failure
 */
static int __init fcoe_init(void)
{
        struct fcoe_percpu_s *p;
        unsigned int cpu;
        int rc = 0;

        mutex_lock(&fcoe_config_mutex);

        for_each_possible_cpu(cpu) {
                p = &per_cpu(fcoe_percpu, cpu);
                skb_queue_head_init(&p->fcoe_rx_list);
        }

        for_each_online_cpu(cpu)
                fcoe_percpu_thread_create(cpu);

        /* Initialize per CPU interrupt thread */
        rc = register_hotcpu_notifier(&fcoe_cpu_notifier);
        if (rc)
                goto out_free;

        /* Setup link change notification */
        fcoe_dev_setup();

        rc = fcoe_if_init();
        if (rc)
                goto out_free;

        mutex_unlock(&fcoe_config_mutex);
        return 0;

out_free:
        for_each_online_cpu(cpu) {
                fcoe_percpu_thread_destroy(cpu);
        }
        mutex_unlock(&fcoe_config_mutex);
        return rc;
}
module_init(fcoe_init);

/**
 * fcoe_exit() - Clean up fcoe.ko
 *
 * Returns: 0 on success or a  negative value on failure
 */
static void __exit fcoe_exit(void)
{
        struct fcoe_interface *fcoe, *tmp;
        struct fcoe_port *port;
        unsigned int cpu;

        mutex_lock(&fcoe_config_mutex);

        fcoe_dev_cleanup();

        /* releases the associated fcoe hosts */
        rtnl_lock();
        list_for_each_entry_safe(fcoe, tmp, &fcoe_hostlist, list) {
                list_del(&fcoe->list);
                port = lport_priv(fcoe->ctlr.lp);
                fcoe_interface_cleanup(fcoe);
                schedule_work(&port->destroy_work);
        }
        rtnl_unlock();

        unregister_hotcpu_notifier(&fcoe_cpu_notifier);

        for_each_online_cpu(cpu)
                fcoe_percpu_thread_destroy(cpu);

        mutex_unlock(&fcoe_config_mutex);

        /* flush any asyncronous interface destroys,
         * this should happen after the netdev notifier is unregistered */
        flush_scheduled_work();
        /* That will flush out all the N_Ports on the hostlist, but now we
         * may have NPIV VN_Ports scheduled for destruction */
        flush_scheduled_work();

        /* detach from scsi transport
         * must happen after all destroys are done, therefor after the flush */
        fcoe_if_exit();
}
module_exit(fcoe_exit);

/**
 * fcoe_flogi_resp() - FCoE specific FLOGI and FDISC response handler
 * @seq: active sequence in the FLOGI or FDISC exchange
 * @fp: response frame, or error encoded in a pointer (timeout)
 * @arg: pointer the the fcoe_ctlr structure
 *
 * This handles MAC address managment for FCoE, then passes control on to
 * the libfc FLOGI response handler.
 */
static void fcoe_flogi_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
{
        struct fcoe_ctlr *fip = arg;
        struct fc_exch *exch = fc_seq_exch(seq);
        struct fc_lport *lport = exch->lp;
        u8 *mac;

        if (IS_ERR(fp))
                goto done;

        mac = fr_cb(fp)->granted_mac;
        if (is_zero_ether_addr(mac)) {
                /* pre-FIP */
                if (fcoe_ctlr_recv_flogi(fip, lport, fp)) {
                        fc_frame_free(fp);
                        return;
                }
        }
        fcoe_update_src_mac(lport, mac);
done:
        fc_lport_flogi_resp(seq, fp, lport);
}

/**
 * fcoe_logo_resp() - FCoE specific LOGO response handler
 * @seq: active sequence in the LOGO exchange
 * @fp: response frame, or error encoded in a pointer (timeout)
 * @arg: pointer the the fcoe_ctlr structure
 *
 * This handles MAC address managment for FCoE, then passes control on to
 * the libfc LOGO response handler.
 */
static void fcoe_logo_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
{
        struct fc_lport *lport = arg;
        static u8 zero_mac[ETH_ALEN] = { 0 };

        if (!IS_ERR(fp))
                fcoe_update_src_mac(lport, zero_mac);
        fc_lport_logo_resp(seq, fp, lport);
}

/**
 * fcoe_elsct_send - FCoE specific ELS handler
 *
 * This does special case handling of FIP encapsualted ELS exchanges for FCoE,
 * using FCoE specific response handlers and passing the FIP controller as
 * the argument (the lport is still available from the exchange).
 *
 * Most of the work here is just handed off to the libfc routine.
 */
static struct fc_seq *fcoe_elsct_send(struct fc_lport *lport, u32 did,
                                      struct fc_frame *fp, unsigned int op,
                                      void (*resp)(struct fc_seq *,
                                                   struct fc_frame *,
                                                   void *),
                                      void *arg, u32 timeout)
{
        struct fcoe_port *port = lport_priv(lport);
        struct fcoe_interface *fcoe = port->fcoe;
        struct fcoe_ctlr *fip = &fcoe->ctlr;
        struct fc_frame_header *fh = fc_frame_header_get(fp);

        switch (op) {
        case ELS_FLOGI:
        case ELS_FDISC:
                return fc_elsct_send(lport, did, fp, op, fcoe_flogi_resp,
                                     fip, timeout);
        case ELS_LOGO:
                /* only hook onto fabric logouts, not port logouts */
                if (ntoh24(fh->fh_d_id) != FC_FID_FLOGI)
                        break;
                return fc_elsct_send(lport, did, fp, op, fcoe_logo_resp,
                                     lport, timeout);
        }
        return fc_elsct_send(lport, did, fp, op, resp, arg, timeout);
}

/**
 * fcoe_vport_create() - create an fc_host/scsi_host for a vport
 * @vport: fc_vport object to create a new fc_host for
 * @disabled: start the new fc_host in a disabled state by default?
 *
 * Returns: 0 for success
 */
static int fcoe_vport_create(struct fc_vport *vport, bool disabled)
{
        struct Scsi_Host *shost = vport_to_shost(vport);
        struct fc_lport *n_port = shost_priv(shost);
        struct fcoe_port *port = lport_priv(n_port);
        struct fcoe_interface *fcoe = port->fcoe;
        struct net_device *netdev = fcoe->netdev;
        struct fc_lport *vn_port;

        mutex_lock(&fcoe_config_mutex);
        vn_port = fcoe_if_create(fcoe, &vport->dev, 1);
        mutex_unlock(&fcoe_config_mutex);

        if (IS_ERR(vn_port)) {
                printk(KERN_ERR "fcoe: fcoe_vport_create(%s) failed\n",
                       netdev->name);
                return -EIO;
        }

        if (disabled) {
                fc_vport_set_state(vport, FC_VPORT_DISABLED);
        } else {
                vn_port->boot_time = jiffies;
                fc_fabric_login(vn_port);
                fc_vport_setlink(vn_port);
        }
        return 0;
}

/**
 * fcoe_vport_destroy() - destroy the fc_host/scsi_host for a vport
 * @vport: fc_vport object that is being destroyed
 *
 * Returns: 0 for success
 */
static int fcoe_vport_destroy(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 = vport->dd_data;
        struct fcoe_port *port = lport_priv(vn_port);

        mutex_lock(&n_port->lp_mutex);
        list_del(&vn_port->list);
        mutex_unlock(&n_port->lp_mutex);
        schedule_work(&port->destroy_work);
        return 0;
}

/**
 * fcoe_vport_disable() - change vport state
 * @vport: vport to bring online/offline
 * @disable: should the vport be disabled?
 */
static int fcoe_vport_disable(struct fc_vport *vport, bool disable)
{
        struct fc_lport *lport = vport->dd_data;

        if (disable) {
                fc_vport_set_state(vport, FC_VPORT_DISABLED);
                fc_fabric_logoff(lport);
        } else {
                lport->boot_time = jiffies;
                fc_fabric_login(lport);
                fc_vport_setlink(lport);
        }

        return 0;
}

/**
 * fcoe_vport_set_symbolic_name() - append vport string to symbolic name
 * @vport: fc_vport with a new symbolic name string
 *
 * After generating a new symbolic name string, a new RSPN_ID request is
 * sent to the name server.  There is no response handler, so if it fails
 * for some reason it will not be retried.
 */
static void fcoe_set_vport_symbolic_name(struct fc_vport *vport)
{
        struct fc_lport *lport = vport->dd_data;
        struct fc_frame *fp;
        size_t len;

        snprintf(fc_host_symbolic_name(lport->host), FC_SYMBOLIC_NAME_SIZE,
                 "%s v%s over %s : %s", FCOE_NAME, FCOE_VERSION,
                 fcoe_netdev(lport)->name, vport->symbolic_name);

        if (lport->state != LPORT_ST_READY)
                return;

        len = strnlen(fc_host_symbolic_name(lport->host), 255);
        fp = fc_frame_alloc(lport,
                            sizeof(struct fc_ct_hdr) +
                            sizeof(struct fc_ns_rspn) + len);
        if (!fp)
                return;
        lport->tt.elsct_send(lport, FC_FID_DIR_SERV, fp, FC_NS_RSPN_ID,
                             NULL, NULL, 3 * lport->r_a_tov);
}