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[linux-rt-nao.git] / drivers / scsi / fcoe / libfcoe.c

/*
 * Copyright(c) 2007 - 2008 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/kernel.h>
#include <linux/spinlock.h>
#include <linux/skbuff.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/kthread.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/libfc.h>
#include <scsi/fc_frame.h>
#include <scsi/libfcoe.h>
#include <scsi/fc_transport_fcoe.h>

static int debug_fcoe;

#define FCOE_MAX_QUEUE_DEPTH  256
#define FCOE_LOW_QUEUE_DEPTH  32

/* destination address mode */
#define FCOE_GW_ADDR_MODE           0x00
#define FCOE_FCOUI_ADDR_MODE        0x01

#define FCOE_WORD_TO_BYTE  4

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

/* fcoe host list */
LIST_HEAD(fcoe_hostlist);
DEFINE_RWLOCK(fcoe_hostlist_lock);
DEFINE_TIMER(fcoe_timer, NULL, 0, 0);
struct fcoe_percpu_s *fcoe_percpu[NR_CPUS];


/* Function Prototyes */
static int fcoe_check_wait_queue(struct fc_lport *);
static void fcoe_recv_flogi(struct fcoe_softc *, struct fc_frame *, u8 *);
#ifdef CONFIG_HOTPLUG_CPU
static int fcoe_cpu_callback(struct notifier_block *, ulong, void *);
#endif /* CONFIG_HOTPLUG_CPU */
static int fcoe_device_notification(struct notifier_block *, ulong, void *);
static void fcoe_dev_setup(void);
static void fcoe_dev_cleanup(void);

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


#ifdef CONFIG_HOTPLUG_CPU
static struct notifier_block fcoe_cpu_notifier = {
        .notifier_call = fcoe_cpu_callback,
};

/**
 * fcoe_create_percpu_data() - creates the associated cpu data
 * @cpu: index for the cpu where fcoe cpu data will be created
 *
 * create percpu stats block, from cpu add notifier
 *
 * Returns: none
 */
static void fcoe_create_percpu_data(int cpu)
{
        struct fc_lport *lp;
        struct fcoe_softc *fc;

        write_lock_bh(&fcoe_hostlist_lock);
        list_for_each_entry(fc, &fcoe_hostlist, list) {
                lp = fc->lp;
                if (lp->dev_stats[cpu] == NULL)
                        lp->dev_stats[cpu] =
                                kzalloc(sizeof(struct fcoe_dev_stats),
                                        GFP_KERNEL);
        }
        write_unlock_bh(&fcoe_hostlist_lock);
}

/**
 * fcoe_destroy_percpu_data() - destroys the associated cpu data
 * @cpu: index for the cpu where fcoe cpu data will destroyed
 *
 * destroy percpu stats block called by cpu add/remove notifier
 *
 * Retuns: none
 */
static void fcoe_destroy_percpu_data(int cpu)
{
        struct fc_lport *lp;
        struct fcoe_softc *fc;

        write_lock_bh(&fcoe_hostlist_lock);
        list_for_each_entry(fc, &fcoe_hostlist, list) {
                lp = fc->lp;
                kfree(lp->dev_stats[cpu]);
                lp->dev_stats[cpu] = NULL;
        }
        write_unlock_bh(&fcoe_hostlist_lock);
}

/**
 * fcoe_cpu_callback() - fcoe cpu hotplug event callback
 * @nfb: callback data block
 * @action: event triggering the callback
 * @hcpu: index for the cpu of this event
 *
 * 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 int cpu = (unsigned long)hcpu;

        switch (action) {
        case CPU_ONLINE:
                fcoe_create_percpu_data(cpu);
                break;
        case CPU_DEAD:
                fcoe_destroy_percpu_data(cpu);
                break;
        default:
                break;
        }
        return NOTIFY_OK;
}
#endif /* CONFIG_HOTPLUG_CPU */

/**
 * fcoe_rcv() - this is the fcoe receive function called by NET_RX_SOFTIRQ
 * @skb: the receive skb
 * @dev: associated net device
 * @ptype: context
 * @odldev: last device
 *
 * this function will receive the packet and build fc frame and pass it up
 *
 * Returns: 0 for success
 */
int fcoe_rcv(struct sk_buff *skb, struct net_device *dev,
             struct packet_type *ptype, struct net_device *olddev)
{
        struct fc_lport *lp;
        struct fcoe_rcv_info *fr;
        struct fcoe_softc *fc;
        struct fcoe_dev_stats *stats;
        struct fc_frame_header *fh;
        unsigned short oxid;
        int cpu_idx;
        struct fcoe_percpu_s *fps;

        fc = container_of(ptype, struct fcoe_softc, fcoe_packet_type);
        lp = fc->lp;
        if (unlikely(lp == NULL)) {
                FC_DBG("cannot find hba structure");
                goto err2;
        }

        if (unlikely(debug_fcoe)) {
                FC_DBG("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))) {
                FC_DBG("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);

        oxid = ntohs(fh->fh_ox_id);

        fr = fcoe_dev_from_skb(skb);
        fr->fr_dev = lp;
        fr->ptype = ptype;
        cpu_idx = 0;
#ifdef CONFIG_SMP
        /*
         * The incoming frame exchange id(oxid) is ANDed with num of online
         * cpu bits to get cpu_idx and then this cpu_idx is used for selecting
         * a per cpu kernel thread from fcoe_percpu. In case the cpu is
         * offline or no kernel thread for derived cpu_idx then cpu_idx is
         * initialize to first online cpu index.
         */
        cpu_idx = oxid & (num_online_cpus() - 1);
        if (!fcoe_percpu[cpu_idx] || !cpu_online(cpu_idx))
                cpu_idx = first_cpu(cpu_online_map);
#endif
        fps = fcoe_percpu[cpu_idx];

        spin_lock_bh(&fps->fcoe_rx_list.lock);
        __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:
#ifdef CONFIG_SMP
        stats = lp->dev_stats[smp_processor_id()];
#else
        stats = lp->dev_stats[0];
#endif
        if (stats)
                stats->ErrorFrames++;

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

/**
 * fcoe_start_io() - pass to netdev to start xmit for fcoe
 * @skb: the skb to be xmitted
 *
 * Returns: 0 for success
 */
static inline int fcoe_start_io(struct sk_buff *skb)
{
        int rc;

        skb_get(skb);
        rc = dev_queue_xmit(skb);
        if (rc != 0)
                return rc;
        kfree_skb(skb);
        return 0;
}

/**
 * fcoe_get_paged_crc_eof() - in case we need alloc a page for crc_eof
 * @skb: the skb to be xmitted
 * @tlen: total len
 *
 * 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;
        int cpu_idx;

        cpu_idx = get_cpu();
        fps = fcoe_percpu[cpu_idx];
        page = fps->crc_eof_page;
        if (!page) {
                page = alloc_page(GFP_ATOMIC);
                if (!page) {
                        put_cpu();
                        return -ENOMEM;
                }
                fps->crc_eof_page = page;
                WARN_ON(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();
        return 0;
}

/**
 * fcoe_fc_crc() - calculates FC CRC in this fcoe skb
 * @fp: the fc_frame containg data to be checksummed
 *
 * This uses crc32() to calculate the crc for fc frame
 * Return   : 32 bit crc
 */
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;
}
EXPORT_SYMBOL_GPL(fcoe_fc_crc);

/**
 * fcoe_xmit() - FCoE frame transmit function
 * @lp: the associated local port
 * @fp: the fc_frame to be transmitted
 *
 * Return   : 0 for success
 */
int fcoe_xmit(struct fc_lport *lp, struct fc_frame *fp)
{
        int wlen, rc = 0;
        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 */
        int flogi_in_progress = 0;
        struct fcoe_softc *fc;
        u8 sof, eof;
        struct fcoe_hdr *hp;

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

        fc = lport_priv(lp);
        /*
         * if it is a flogi then we need to learn gw-addr
         * and my own fcid
         */
        fh = fc_frame_header_get(fp);
        if (unlikely(fh->fh_r_ctl == FC_RCTL_ELS_REQ)) {
                if (fc_frame_payload_op(fp) == ELS_FLOGI) {
                        fc->flogi_oxid = ntohs(fh->fh_ox_id);
                        fc->address_mode = FCOE_FCOUI_ADDR_MODE;
                        fc->flogi_progress = 1;
                        flogi_in_progress = 1;
                } else if (fc->flogi_progress && ntoh24(fh->fh_s_id) != 0) {
                        /*
                         * Here we must've gotten an SID by accepting an FLOGI
                         * from a point-to-point connection.  Switch to using
                         * the source mac based on the SID.  The destination
                         * MAC in this case would have been set by receving the
                         * FLOGI.
                         */
                        fc_fcoe_set_mac(fc->data_src_addr, fh->fh_s_id);
                        fc->flogi_progress = 0;
                }
        }

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

        elen = (fc->real_dev->priv_flags & IFF_802_1Q_VLAN) ?
                sizeof(struct vlan_ethhdr) : 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(lp->crc_offload)) {
                skb->ip_summed = CHECKSUM_COMPLETE;
                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 fc 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 netowrk/transport offsets to match mac/fcoe/fc */
        skb_push(skb, elen + hlen);
        skb_reset_mac_header(skb);
        skb_reset_network_header(skb);
        skb->mac_len = elen;
        skb->protocol = htons(ETH_P_802_3);
        skb->dev = fc->real_dev;

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

        if (unlikely(flogi_in_progress))
                memcpy(eh->h_source, fc->ctl_src_addr, ETH_ALEN);
        else
                memcpy(eh->h_source, fc->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;

        /* update tx stats: regardless if LLD fails */
        stats = lp->dev_stats[smp_processor_id()];
        if (stats) {
                stats->TxFrames++;
                stats->TxWords += wlen;
        }

        /* send down to lld */
        fr_dev(fp) = lp;
        if (fc->fcoe_pending_queue.qlen)
                rc = fcoe_check_wait_queue(lp);

        if (rc == 0)
                rc = fcoe_start_io(skb);

        if (rc) {
                spin_lock_bh(&fc->fcoe_pending_queue.lock);
                __skb_queue_tail(&fc->fcoe_pending_queue, skb);
                spin_unlock_bh(&fc->fcoe_pending_queue.lock);
                if (fc->fcoe_pending_queue.qlen > FCOE_MAX_QUEUE_DEPTH)
                        lp->qfull = 1;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(fcoe_xmit);

/**
 * fcoe_percpu_receive_thread() - recv thread per cpu
 * @arg: ptr to the fcoe per cpu struct
 *
 * Return: 0 for success
 */
int fcoe_percpu_receive_thread(void *arg)
{
        struct fcoe_percpu_s *p = arg;
        u32 fr_len;
        struct fc_lport *lp;
        struct fcoe_rcv_info *fr;
        struct fcoe_dev_stats *stats;
        struct fc_frame_header *fh;
        struct sk_buff *skb;
        struct fcoe_crc_eof crc_eof;
        struct fc_frame *fp;
        u8 *mac = NULL;
        struct fcoe_softc *fc;
        struct fcoe_hdr *hp;

        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);
                fr = fcoe_dev_from_skb(skb);
                lp = fr->fr_dev;
                if (unlikely(lp == NULL)) {
                        FC_DBG("invalid HBA Structure");
                        kfree_skb(skb);
                        continue;
                }

                stats = lp->dev_stats[smp_processor_id()];

                if (unlikely(debug_fcoe)) {
                        FC_DBG("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.
                 */
                fc = lport_priv(lp);
                if (unlikely(fc->flogi_progress))
                        mac = eth_hdr(skb)->h_source;

                if (skb_is_nonlinear(skb))
                        skb_linearize(skb);     /* not ideal */

                /*
                 * 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);

                if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
                        if (stats) {
                                if (stats->ErrorFrames < 5)
                                        FC_DBG("unknown FCoE version %x",
                                               FC_FCOE_DECAPS_VER(hp));
                                stats->ErrorFrames++;
                        }
                        kfree_skb(skb);
                        continue;
                }

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

                if (stats) {
                        stats->RxFrames++;
                        stats->RxWords += fr_len / FCOE_WORD_TO_BYTE;
                }

                fp = (struct fc_frame *)skb;
                fc_frame_init(fp);
                fr_dev(fp) = lp;
                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);
                        continue;
                }
                fr_eof(fp) = crc_eof.fcoe_eof;
                fr_crc(fp) = crc_eof.fcoe_crc32;
                if (pskb_trim(skb, fr_len)) {
                        kfree_skb(skb);
                        continue;
                }

                /*
                 * 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 (lp->crc_offload)
                        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(lp, lp->emp, fp);
                        continue;
                }
                if (fr_flags(fp) & FCPHF_CRC_UNCHECKED) {
                        if (le32_to_cpu(fr_crc(fp)) !=
                            ~crc32(~0, skb->data, fr_len)) {
                                if (debug_fcoe || stats->InvalidCRCCount < 5)
                                        printk(KERN_WARNING "fcoe: dropping "
                                               "frame with CRC error\n");
                                stats->InvalidCRCCount++;
                                stats->ErrorFrames++;
                                fc_frame_free(fp);
                                continue;
                        }
                        fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
                }
                /* non flogi and non data exchanges are handled here */
                if (unlikely(fc->flogi_progress))
                        fcoe_recv_flogi(fc, fp, mac);
                fc_exch_recv(lp, lp->emp, fp);
        }
        return 0;
}

/**
 * fcoe_recv_flogi() - flogi receive function
 * @fc: associated fcoe_softc
 * @fp: the recieved frame
 * @sa: the source address of this flogi
 *
 * This is responsible to parse the flogi response and sets the corresponding
 * mac address for the initiator, eitehr OUI based or GW based.
 *
 * Returns: none
 */
static void fcoe_recv_flogi(struct fcoe_softc *fc, struct fc_frame *fp, u8 *sa)
{
        struct fc_frame_header *fh;
        u8 op;

        fh = fc_frame_header_get(fp);
        if (fh->fh_type != FC_TYPE_ELS)
                return;
        op = fc_frame_payload_op(fp);
        if (op == ELS_LS_ACC && fh->fh_r_ctl == FC_RCTL_ELS_REP &&
            fc->flogi_oxid == ntohs(fh->fh_ox_id)) {
                /*
                 * FLOGI accepted.
                 * If the src mac addr is FC_OUI-based, then we mark the
                 * address_mode flag to use FC_OUI-based Ethernet DA.
                 * Otherwise we use the FCoE gateway addr
                 */
                if (!compare_ether_addr(sa, (u8[6]) FC_FCOE_FLOGI_MAC)) {
                        fc->address_mode = FCOE_FCOUI_ADDR_MODE;
                } else {
                        memcpy(fc->dest_addr, sa, ETH_ALEN);
                        fc->address_mode = FCOE_GW_ADDR_MODE;
                }

                /*
                 * Remove any previously-set unicast MAC filter.
                 * Add secondary FCoE MAC address filter for our OUI.
                 */
                rtnl_lock();
                if (compare_ether_addr(fc->data_src_addr, (u8[6]) { 0 }))
                        dev_unicast_delete(fc->real_dev, fc->data_src_addr,
                                           ETH_ALEN);
                fc_fcoe_set_mac(fc->data_src_addr, fh->fh_d_id);
                dev_unicast_add(fc->real_dev, fc->data_src_addr, ETH_ALEN);
                rtnl_unlock();

                fc->flogi_progress = 0;
        } else if (op == ELS_FLOGI && fh->fh_r_ctl == FC_RCTL_ELS_REQ && sa) {
                /*
                 * Save source MAC for point-to-point responses.
                 */
                memcpy(fc->dest_addr, sa, ETH_ALEN);
                fc->address_mode = FCOE_GW_ADDR_MODE;
        }
}

/**
 * fcoe_watchdog() - fcoe timer callback
 * @vp:
 *
 * This checks the pending queue length for fcoe and set lport qfull
 * if the FCOE_MAX_QUEUE_DEPTH is reached. This is done for all fc_lport on the
 * fcoe_hostlist.
 *
 * Returns: 0 for success
 */
void fcoe_watchdog(ulong vp)
{
        struct fcoe_softc *fc;

        read_lock(&fcoe_hostlist_lock);
        list_for_each_entry(fc, &fcoe_hostlist, list) {
                if (fc->lp)
                        fcoe_check_wait_queue(fc->lp);
        }
        read_unlock(&fcoe_hostlist_lock);

        fcoe_timer.expires = jiffies + (1 * HZ);
        add_timer(&fcoe_timer);
}


/**
 * fcoe_check_wait_queue() - put the skb into fcoe pending xmit queue
 * @lp: the fc_port for this skb
 * @skb: the associated skb to be xmitted
 *
 * This empties the wait_queue, dequeue the head of the wait_queue queue
 * and calls fcoe_start_io() for each packet, if all skb have been
 * transmitted, return qlen or -1 if a error occurs, then restore
 * wait_queue and  try again later.
 *
 * The wait_queue is used when the skb transmit fails. skb will go
 * in the wait_queue which will be emptied by the time function OR
 * by the next skb transmit.
 *
 * Returns: 0 for success
 */
static int fcoe_check_wait_queue(struct fc_lport *lp)
{
        struct fcoe_softc *fc = lport_priv(lp);
        struct sk_buff *skb;
        int rc = -1;

        spin_lock_bh(&fc->fcoe_pending_queue.lock);
        if (fc->fcoe_pending_queue_active)
                goto out;
        fc->fcoe_pending_queue_active = 1;

        while (fc->fcoe_pending_queue.qlen) {
                /* keep qlen > 0 until fcoe_start_io succeeds */
                fc->fcoe_pending_queue.qlen++;
                skb = __skb_dequeue(&fc->fcoe_pending_queue);

                spin_unlock_bh(&fc->fcoe_pending_queue.lock);
                rc = fcoe_start_io(skb);
                spin_lock_bh(&fc->fcoe_pending_queue.lock);

                if (rc) {
                        __skb_queue_head(&fc->fcoe_pending_queue, skb);
                        /* undo temporary increment above */
                        fc->fcoe_pending_queue.qlen--;
                        break;
                }
                /* undo temporary increment above */
                fc->fcoe_pending_queue.qlen--;
        }

        if (fc->fcoe_pending_queue.qlen < FCOE_LOW_QUEUE_DEPTH)
                lp->qfull = 0;
        fc->fcoe_pending_queue_active = 0;
        rc = fc->fcoe_pending_queue.qlen;
out:
        spin_unlock_bh(&fc->fcoe_pending_queue.lock);
        return rc;
}

/**
 * fcoe_dev_setup() - setup link change notification interface
 */
static void fcoe_dev_setup()
{
        /*
         * here setup a interface specific wd time to
         * monitor the link state
         */
        register_netdevice_notifier(&fcoe_notifier);
}

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

/**
 * fcoe_device_notification() - netdev event notification callback
 * @notifier: context of the notification
 * @event: type of event
 * @ptr: fixed array for output parsed ifname
 *
 * 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 *lp = NULL;
        struct net_device *real_dev = ptr;
        struct fcoe_softc *fc;
        struct fcoe_dev_stats *stats;
        u32 new_link_up;
        u32 mfs;
        int rc = NOTIFY_OK;

        read_lock(&fcoe_hostlist_lock);
        list_for_each_entry(fc, &fcoe_hostlist, list) {
                if (fc->real_dev == real_dev) {
                        lp = fc->lp;
                        break;
                }
        }
        read_unlock(&fcoe_hostlist_lock);
        if (lp == NULL) {
                rc = NOTIFY_DONE;
                goto out;
        }

        new_link_up = lp->link_up;
        switch (event) {
        case NETDEV_DOWN:
        case NETDEV_GOING_DOWN:
                new_link_up = 0;
                break;
        case NETDEV_UP:
        case NETDEV_CHANGE:
                new_link_up = !fcoe_link_ok(lp);
                break;
        case NETDEV_CHANGEMTU:
                mfs = fc->real_dev->mtu -
                        (sizeof(struct fcoe_hdr) +
                         sizeof(struct fcoe_crc_eof));
                if (mfs >= FC_MIN_MAX_FRAME)
                        fc_set_mfs(lp, mfs);
                new_link_up = !fcoe_link_ok(lp);
                break;
        case NETDEV_REGISTER:
                break;
        default:
                FC_DBG("unknown event %ld call", event);
        }
        if (lp->link_up != new_link_up) {
                if (new_link_up)
                        fc_linkup(lp);
                else {
                        stats = lp->dev_stats[smp_processor_id()];
                        if (stats)
                                stats->LinkFailureCount++;
                        fc_linkdown(lp);
                        fcoe_clean_pending_queue(lp);
                }
        }
out:
        return rc;
}

/**
 * fcoe_if_to_netdev() - parse a name buffer to get netdev
 * @ifname: fixed array for output parsed ifname
 * @buffer: incoming buffer to be copied
 *
 * Returns: NULL or ptr to netdeive
 */
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_netdev_to_module_owner() - finds out the nic drive moddule of the netdev
 * @netdev: the target netdev
 *
 * Returns: ptr to the struct module, NULL for failure
 */
static struct module *
fcoe_netdev_to_module_owner(const struct net_device *netdev)
{
        struct device *dev;

        if (!netdev)
                return NULL;

        dev = netdev->dev.parent;
        if (!dev)
                return NULL;

        if (!dev->driver)
                return NULL;

        return dev->driver->owner;
}

/**
 * fcoe_ethdrv_get() - Hold the Ethernet driver
 * @netdev: the target netdev
 *
 * Holds the Ethernet driver module by try_module_get() for
 * the corresponding netdev.
 *
 * Returns: 0 for succsss
 */
static int fcoe_ethdrv_get(const struct net_device *netdev)
{
        struct module *owner;

        owner = fcoe_netdev_to_module_owner(netdev);
        if (owner) {
                printk(KERN_DEBUG "fcoe:hold driver module %s for %s\n",
                       module_name(owner), netdev->name);
                return  try_module_get(owner);
        }
        return -ENODEV;
}

/**
 * fcoe_ethdrv_put() - Release the Ethernet driver
 * @netdev: the target netdev
 *
 * Releases the Ethernet driver module by module_put for
 * the corresponding netdev.
 *
 * Returns: 0 for succsss
 */
static int fcoe_ethdrv_put(const struct net_device *netdev)
{
        struct module *owner;

        owner = fcoe_netdev_to_module_owner(netdev);
        if (owner) {
                printk(KERN_DEBUG "fcoe:release driver module %s for %s\n",
                       module_name(owner), netdev->name);
                module_put(owner);
                return 0;
        }
        return -ENODEV;
}

/**
 * fcoe_destroy() - handles the destroy from sysfs
 * @buffer: expcted to be a eth if name
 * @kp: associated kernel param
 *
 * Returns: 0 for success
 */
static int fcoe_destroy(const char *buffer, struct kernel_param *kp)
{
        int rc;
        struct net_device *netdev;

        netdev = fcoe_if_to_netdev(buffer);
        if (!netdev) {
                rc = -ENODEV;
                goto out_nodev;
        }
        /* look for existing lport */
        if (!fcoe_hostlist_lookup(netdev)) {
                rc = -ENODEV;
                goto out_putdev;
        }
        /* pass to transport */
        rc = fcoe_transport_release(netdev);
        if (rc) {
                printk(KERN_ERR "fcoe: fcoe_transport_release(%s) failed\n",
                       netdev->name);
                rc = -EIO;
                goto out_putdev;
        }
        fcoe_ethdrv_put(netdev);
        rc = 0;
out_putdev:
        dev_put(netdev);
out_nodev:
        return rc;
}

/**
 * fcoe_create() - Handles the create call from sysfs
 * @buffer: expcted to be a eth if name
 * @kp: associated kernel param
 *
 * Returns: 0 for success
 */
static int fcoe_create(const char *buffer, struct kernel_param *kp)
{
        int rc;
        struct net_device *netdev;

        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_ethdrv_get(netdev);

        /* pass to transport */
        rc = fcoe_transport_attach(netdev);
        if (rc) {
                printk(KERN_ERR "fcoe: fcoe_transport_attach(%s) failed\n",
                       netdev->name);
                fcoe_ethdrv_put(netdev);
                rc = -EIO;
                goto out_putdev;
        }
        rc = 0;
out_putdev:
        dev_put(netdev);
out_nodev:
        return rc;
}

module_param_call(create, fcoe_create, NULL, NULL, S_IWUSR);
__MODULE_PARM_TYPE(create, "string");
MODULE_PARM_DESC(create, "Create fcoe port 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 port");

/**
 * fcoe_link_ok() - Check if link is ok for the fc_lport
 * @lp: ptr to the fc_lport
 *
 * 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 *lp)
{
        struct fcoe_softc *fc = lport_priv(lp);
        struct net_device *dev = fc->real_dev;
        struct ethtool_cmd ecmd = { ETHTOOL_GSET };
        int rc = 0;

        if ((dev->flags & IFF_UP) && netif_carrier_ok(dev)) {
                dev = fc->phys_dev;
                if (dev->ethtool_ops->get_settings) {
                        dev->ethtool_ops->get_settings(dev, &ecmd);
                        lp->link_supported_speeds &=
                                ~(FC_PORTSPEED_1GBIT | FC_PORTSPEED_10GBIT);
                        if (ecmd.supported & (SUPPORTED_1000baseT_Half |
                                              SUPPORTED_1000baseT_Full))
                                lp->link_supported_speeds |= FC_PORTSPEED_1GBIT;
                        if (ecmd.supported & SUPPORTED_10000baseT_Full)
                                lp->link_supported_speeds |=
                                        FC_PORTSPEED_10GBIT;
                        if (ecmd.speed == SPEED_1000)
                                lp->link_speed = FC_PORTSPEED_1GBIT;
                        if (ecmd.speed == SPEED_10000)
                                lp->link_speed = FC_PORTSPEED_10GBIT;
                }
        } else
                rc = -1;

        return rc;
}
EXPORT_SYMBOL_GPL(fcoe_link_ok);

/**
 * fcoe_percpu_clean() - Clear the pending skbs for an lport
 * @lp: the fc_lport
 */
void fcoe_percpu_clean(struct fc_lport *lp)
{
        int idx;
        struct fcoe_percpu_s *pp;
        struct fcoe_rcv_info *fr;
        struct sk_buff_head *list;
        struct sk_buff *skb, *next;
        struct sk_buff *head;

        for (idx = 0; idx < NR_CPUS; idx++) {
                if (fcoe_percpu[idx]) {
                        pp = fcoe_percpu[idx];
                        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 == lp) {
                                        __skb_unlink(skb, list);
                                        kfree_skb(skb);
                                }
                        }
                        spin_unlock_bh(&pp->fcoe_rx_list.lock);
                }
        }
}
EXPORT_SYMBOL_GPL(fcoe_percpu_clean);

/**
 * fcoe_clean_pending_queue() - Dequeue a skb and free it
 * @lp: the corresponding fc_lport
 *
 * Returns: none
 */
void fcoe_clean_pending_queue(struct fc_lport *lp)
{
        struct fcoe_softc  *fc = lport_priv(lp);
        struct sk_buff *skb;

        spin_lock_bh(&fc->fcoe_pending_queue.lock);
        while ((skb = __skb_dequeue(&fc->fcoe_pending_queue)) != NULL) {
                spin_unlock_bh(&fc->fcoe_pending_queue.lock);
                kfree_skb(skb);
                spin_lock_bh(&fc->fcoe_pending_queue.lock);
        }
        spin_unlock_bh(&fc->fcoe_pending_queue.lock);
}
EXPORT_SYMBOL_GPL(fcoe_clean_pending_queue);

/**
 * libfc_host_alloc() - Allocate a Scsi_Host with room for the fc_lport
 * @sht: ptr to the scsi host templ
 * @priv_size: size of private data after fc_lport
 *
 * Returns: ptr to Scsi_Host
 * TODO: to libfc?
 */
static inline struct Scsi_Host *
libfc_host_alloc(struct scsi_host_template *sht, int priv_size)
{
        return scsi_host_alloc(sht, sizeof(struct fc_lport) + priv_size);
}

/**
 * fcoe_host_alloc() - Allocate a Scsi_Host with room for the fcoe_softc
 * @sht: ptr to the scsi host templ
 * @priv_size: size of private data after fc_lport
 *
 * Returns: ptr to Scsi_Host
 */
struct Scsi_Host *fcoe_host_alloc(struct scsi_host_template *sht, int priv_size)
{
        return libfc_host_alloc(sht, sizeof(struct fcoe_softc) + priv_size);
}
EXPORT_SYMBOL_GPL(fcoe_host_alloc);

/**
 * fcoe_reset() - Resets the fcoe
 * @shost: shost the reset is from
 *
 * Returns: always 0
 */
int fcoe_reset(struct Scsi_Host *shost)
{
        struct fc_lport *lport = shost_priv(shost);
        fc_lport_reset(lport);
        return 0;
}
EXPORT_SYMBOL_GPL(fcoe_reset);

/**
 * fcoe_wwn_from_mac() - Converts 48-bit IEEE MAC address to 64-bit FC WWN.
 * @mac: mac address
 * @scheme: check port
 * @port: port indicator for converting
 *
 * Returns: u64 fc world wide name
 */
u64 fcoe_wwn_from_mac(unsigned char mac[MAX_ADDR_LEN],
                      unsigned int scheme, unsigned int port)
{
        u64 wwn;
        u64 host_mac;

        /* The MAC is in NO, so flip only the low 48 bits */
        host_mac = ((u64) mac[0] << 40) |
                ((u64) mac[1] << 32) |
                ((u64) mac[2] << 24) |
                ((u64) mac[3] << 16) |
                ((u64) mac[4] << 8) |
                (u64) mac[5];

        WARN_ON(host_mac >= (1ULL << 48));
        wwn = host_mac | ((u64) scheme << 60);
        switch (scheme) {
        case 1:
                WARN_ON(port != 0);
                break;
        case 2:
                WARN_ON(port >= 0xfff);
                wwn |= (u64) port << 48;
                break;
        default:
                WARN_ON(1);
                break;
        }

        return wwn;
}
EXPORT_SYMBOL_GPL(fcoe_wwn_from_mac);

/**
 * fcoe_hostlist_lookup_softc() - find the corresponding lport by a given device
 * @device: this is currently ptr to net_device
 *
 * Returns: NULL or the located fcoe_softc
 */
static struct fcoe_softc *
fcoe_hostlist_lookup_softc(const struct net_device *dev)
{
        struct fcoe_softc *fc;

        read_lock(&fcoe_hostlist_lock);
        list_for_each_entry(fc, &fcoe_hostlist, list) {
                if (fc->real_dev == dev) {
                        read_unlock(&fcoe_hostlist_lock);
                        return fc;
                }
        }
        read_unlock(&fcoe_hostlist_lock);
        return NULL;
}

/**
 * fcoe_hostlist_lookup() - Find the corresponding lport by netdev
 * @netdev: ptr to net_device
 *
 * Returns: 0 for success
 */
struct fc_lport *fcoe_hostlist_lookup(const struct net_device *netdev)
{
        struct fcoe_softc *fc;

        fc = fcoe_hostlist_lookup_softc(netdev);

        return (fc) ? fc->lp : NULL;
}
EXPORT_SYMBOL_GPL(fcoe_hostlist_lookup);

/**
 * fcoe_hostlist_add() - Add a lport to lports list
 * @lp: ptr to the fc_lport to badded
 *
 * Returns: 0 for success
 */
int fcoe_hostlist_add(const struct fc_lport *lp)
{
        struct fcoe_softc *fc;

        fc = fcoe_hostlist_lookup_softc(fcoe_netdev(lp));
        if (!fc) {
                fc = lport_priv(lp);
                write_lock_bh(&fcoe_hostlist_lock);
                list_add_tail(&fc->list, &fcoe_hostlist);
                write_unlock_bh(&fcoe_hostlist_lock);
        }
        return 0;
}
EXPORT_SYMBOL_GPL(fcoe_hostlist_add);

/**
 * fcoe_hostlist_remove() - remove a lport from lports list
 * @lp: ptr to the fc_lport to badded
 *
 * Returns: 0 for success
 */
int fcoe_hostlist_remove(const struct fc_lport *lp)
{
        struct fcoe_softc *fc;

        fc = fcoe_hostlist_lookup_softc(fcoe_netdev(lp));
        BUG_ON(!fc);
        write_lock_bh(&fcoe_hostlist_lock);
        list_del(&fc->list);
        write_unlock_bh(&fcoe_hostlist_lock);

        return 0;
}
EXPORT_SYMBOL_GPL(fcoe_hostlist_remove);

/**
 * fcoe_libfc_config() - sets up libfc related properties for lport
 * @lp: ptr to the fc_lport
 * @tt: libfc function template
 *
 * Returns : 0 for success
 */
int fcoe_libfc_config(struct fc_lport *lp, struct libfc_function_template *tt)
{
        /* Set the function pointers set by the LLDD */
        memcpy(&lp->tt, tt, sizeof(*tt));
        if (fc_fcp_init(lp))
                return -ENOMEM;
        fc_exch_init(lp);
        fc_elsct_init(lp);
        fc_lport_init(lp);
        fc_rport_init(lp);
        fc_disc_init(lp);

        return 0;
}
EXPORT_SYMBOL_GPL(fcoe_libfc_config);

/**
 * fcoe_init() - fcoe module loading initialization
 *
 * Initialization routine
 * 1. Will create fc transport software structure
 * 2. initialize the link list of port information structure
 *
 * Returns 0 on success, negative on failure
 */
static int __init fcoe_init(void)
{
        int cpu;
        struct fcoe_percpu_s *p;


        INIT_LIST_HEAD(&fcoe_hostlist);
        rwlock_init(&fcoe_hostlist_lock);

#ifdef CONFIG_HOTPLUG_CPU
        register_cpu_notifier(&fcoe_cpu_notifier);
#endif /* CONFIG_HOTPLUG_CPU */

        /*
         * initialize per CPU interrupt thread
         */
        for_each_online_cpu(cpu) {
                p = kzalloc(sizeof(struct fcoe_percpu_s), GFP_KERNEL);
                if (p) {
                        p->thread = kthread_create(fcoe_percpu_receive_thread,
                                                   (void *)p,
                                                   "fcoethread/%d", cpu);

                        /*
                         * if there is no error then bind the thread to the cpu
                         * initialize the semaphore and skb queue head
                         */
                        if (likely(!IS_ERR(p->thread))) {
                                p->cpu = cpu;
                                fcoe_percpu[cpu] = p;
                                skb_queue_head_init(&p->fcoe_rx_list);
                                kthread_bind(p->thread, cpu);
                                wake_up_process(p->thread);
                        } else {
                                fcoe_percpu[cpu] = NULL;
                                kfree(p);
                        }
                }
        }

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

        setup_timer(&fcoe_timer, fcoe_watchdog, 0);

        mod_timer(&fcoe_timer, jiffies + (10 * HZ));

        /* initiatlize the fcoe transport */
        fcoe_transport_init();

        fcoe_sw_init();

        return 0;
}
module_init(fcoe_init);

/**
 * fcoe_exit() - fcoe module unloading cleanup
 *
 * Returns 0 on success, negative on failure
 */
static void __exit fcoe_exit(void)
{
        u32 idx;
        struct fcoe_softc *fc, *tmp;
        struct fcoe_percpu_s *p;
        struct sk_buff *skb;

        /*
         * Stop all call back interfaces
         */
#ifdef CONFIG_HOTPLUG_CPU
        unregister_cpu_notifier(&fcoe_cpu_notifier);
#endif /* CONFIG_HOTPLUG_CPU */
        fcoe_dev_cleanup();

        /*
         * stop timer
         */
        del_timer_sync(&fcoe_timer);

        /* releases the associated fcoe transport for each lport */
        list_for_each_entry_safe(fc, tmp, &fcoe_hostlist, list)
                fcoe_transport_release(fc->real_dev);

        for (idx = 0; idx < NR_CPUS; idx++) {
                if (fcoe_percpu[idx]) {
                        kthread_stop(fcoe_percpu[idx]->thread);
                        p = fcoe_percpu[idx];
                        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);
                        if (fcoe_percpu[idx]->crc_eof_page)
                                put_page(fcoe_percpu[idx]->crc_eof_page);
                        kfree(fcoe_percpu[idx]);
                }
        }

        /* remove sw trasnport */
        fcoe_sw_exit();

        /* detach the transport */
        fcoe_transport_exit();
}
module_exit(fcoe_exit);