ipoib_main.c

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/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 * Copyright (c) 2004 Voltaire, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "ipoib.h"

#include <linux/module.h>

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/vmalloc.h>

#include <linux/if_arp.h>   /* For ARPHRD_xxx */

#include <linux/ip.h>
#include <linux/in.h>

#include <linux/jhash.h>
#include <net/arp.h>

MODULE_AUTHOR("Roland Dreier");
MODULE_DESCRIPTION("IP-over-InfiniBand net driver");
MODULE_LICENSE("Dual BSD/GPL");

int ipoib_sendq_size __read_mostly = IPOIB_TX_RING_SIZE;
int ipoib_recvq_size __read_mostly = IPOIB_RX_RING_SIZE;

module_param_named(send_queue_size, ipoib_sendq_size, int, 0444);
MODULE_PARM_DESC(send_queue_size, "Number of descriptors in send queue");
module_param_named(recv_queue_size, ipoib_recvq_size, int, 0444);
MODULE_PARM_DESC(recv_queue_size, "Number of descriptors in receive queue");

#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
int ipoib_debug_level;

module_param_named(debug_level, ipoib_debug_level, int, 0644);
MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0");
#endif

struct ipoib_path_iter {
    struct net_device *dev;
    struct ipoib_path  path;
};

static const u8 ipv4_bcast_addr[] = {
    0x00, 0xff, 0xff, 0xff,
    0xff, 0x12, 0x40, 0x1b, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff
};

struct workqueue_struct *ipoib_workqueue;

struct ib_sa_client ipoib_sa_client;

static void ipoib_add_one(struct ib_device *device);
static void ipoib_remove_one(struct ib_device *device);
static void ipoib_neigh_reclaim(struct rcu_head *rp);

static struct ib_client ipoib_client = {
    .name   = "ipoib",
    .add    = ipoib_add_one,
    .remove = ipoib_remove_one
};

int ipoib_open(struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    ipoib_dbg(priv, "bringing up interface\n");

    set_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags);

    if (ipoib_pkey_dev_delay_open(dev))
        return 0;

    if (ipoib_ib_dev_open(dev))
        goto err_disable;

    if (ipoib_ib_dev_up(dev))
        goto err_stop;

    if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags)) {
        struct ipoib_dev_priv *cpriv;

        /* Bring up any child interfaces too */
        mutex_lock(&priv->vlan_mutex);
        list_for_each_entry(cpriv, &priv->child_intfs, list) {
            int flags;

            flags = cpriv->dev->flags;
            if (flags & IFF_UP)
                continue;

            dev_change_flags(cpriv->dev, flags | IFF_UP);
        }
        mutex_unlock(&priv->vlan_mutex);
    }

    netif_start_queue(dev);

    return 0;

err_stop:
    ipoib_ib_dev_stop(dev, 1);

err_disable:
    clear_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags);

    return -EINVAL;
}

static int ipoib_stop(struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    ipoib_dbg(priv, "stopping interface\n");

    clear_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags);

    netif_stop_queue(dev);

    ipoib_ib_dev_down(dev, 1);
    ipoib_ib_dev_stop(dev, 0);

    if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags)) {
        struct ipoib_dev_priv *cpriv;

        /* Bring down any child interfaces too */
        mutex_lock(&priv->vlan_mutex);
        list_for_each_entry(cpriv, &priv->child_intfs, list) {
            int flags;

            flags = cpriv->dev->flags;
            if (!(flags & IFF_UP))
                continue;

            dev_change_flags(cpriv->dev, flags & ~IFF_UP);
        }
        mutex_unlock(&priv->vlan_mutex);
    }

    return 0;
}

static void ipoib_uninit(struct net_device *dev)
{
    ipoib_dev_cleanup(dev);
}

static netdev_features_t ipoib_fix_features(struct net_device *dev, netdev_features_t features)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    if (test_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags))
        features &= ~(NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_TSO);

    return features;
}

static int ipoib_change_mtu(struct net_device *dev, int new_mtu)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    /* dev->mtu > 2K ==> connected mode */
    if (ipoib_cm_admin_enabled(dev)) {
        if (new_mtu > ipoib_cm_max_mtu(dev))
            return -EINVAL;

        if (new_mtu > priv->mcast_mtu)
            ipoib_warn(priv, "mtu > %d will cause multicast packet drops.\n",
                   priv->mcast_mtu);

        dev->mtu = new_mtu;
        return 0;
    }

    if (new_mtu > IPOIB_UD_MTU(priv->max_ib_mtu))
        return -EINVAL;

    priv->admin_mtu = new_mtu;

    dev->mtu = min(priv->mcast_mtu, priv->admin_mtu);

    return 0;
}

int ipoib_set_mode(struct net_device *dev, const char *buf)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    /* flush paths if we switch modes so that connections are restarted */
    if (IPOIB_CM_SUPPORTED(dev->dev_addr) && !strcmp(buf, "connected\n")) {
        set_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);
        ipoib_warn(priv, "enabling connected mode "
               "will cause multicast packet drops\n");
        netdev_update_features(dev);
        rtnl_unlock();
        priv->tx_wr.send_flags &= ~IB_SEND_IP_CSUM;

        ipoib_flush_paths(dev);
        rtnl_lock();
        return 0;
    }

    if (!strcmp(buf, "datagram\n")) {
        clear_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);
        netdev_update_features(dev);
        dev_set_mtu(dev, min(priv->mcast_mtu, dev->mtu));
        rtnl_unlock();
        ipoib_flush_paths(dev);
        rtnl_lock();
        return 0;
    }

    return -EINVAL;
}

static struct ipoib_path *__path_find(struct net_device *dev, void *gid)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct rb_node *n = priv->path_tree.rb_node;
    struct ipoib_path *path;
    int ret;

    while (n) {
        path = rb_entry(n, struct ipoib_path, rb_node);

        ret = memcmp(gid, path->pathrec.dgid.raw,
                 sizeof (union ib_gid));

        if (ret < 0)
            n = n->rb_left;
        else if (ret > 0)
            n = n->rb_right;
        else
            return path;
    }

    return NULL;
}

static int __path_add(struct net_device *dev, struct ipoib_path *path)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct rb_node **n = &priv->path_tree.rb_node;
    struct rb_node *pn = NULL;
    struct ipoib_path *tpath;
    int ret;

    while (*n) {
        pn = *n;
        tpath = rb_entry(pn, struct ipoib_path, rb_node);

        ret = memcmp(path->pathrec.dgid.raw, tpath->pathrec.dgid.raw,
                 sizeof (union ib_gid));
        if (ret < 0)
            n = &pn->rb_left;
        else if (ret > 0)
            n = &pn->rb_right;
        else
            return -EEXIST;
    }

    rb_link_node(&path->rb_node, pn, n);
    rb_insert_color(&path->rb_node, &priv->path_tree);

    list_add_tail(&path->list, &priv->path_list);

    return 0;
}

static void path_free(struct net_device *dev, struct ipoib_path *path)
{
    struct sk_buff *skb;

    while ((skb = __skb_dequeue(&path->queue)))
        dev_kfree_skb_irq(skb);

    ipoib_dbg(netdev_priv(dev), "path_free\n");

    /* remove all neigh connected to this path */
    ipoib_del_neighs_by_gid(dev, path->pathrec.dgid.raw);

    if (path->ah)
        ipoib_put_ah(path->ah);

    kfree(path);
}

#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG

struct ipoib_path_iter *ipoib_path_iter_init(struct net_device *dev)
{
    struct ipoib_path_iter *iter;

    iter = kmalloc(sizeof *iter, GFP_KERNEL);
    if (!iter)
        return NULL;

    iter->dev = dev;
    memset(iter->path.pathrec.dgid.raw, 0, 16);

    if (ipoib_path_iter_next(iter)) {
        kfree(iter);
        return NULL;
    }

    return iter;
}

int ipoib_path_iter_next(struct ipoib_path_iter *iter)
{
    struct ipoib_dev_priv *priv = netdev_priv(iter->dev);
    struct rb_node *n;
    struct ipoib_path *path;
    int ret = 1;

    spin_lock_irq(&priv->lock);

    n = rb_first(&priv->path_tree);

    while (n) {
        path = rb_entry(n, struct ipoib_path, rb_node);

        if (memcmp(iter->path.pathrec.dgid.raw, path->pathrec.dgid.raw,
               sizeof (union ib_gid)) < 0) {
            iter->path = *path;
            ret = 0;
            break;
        }

        n = rb_next(n);
    }

    spin_unlock_irq(&priv->lock);

    return ret;
}

void ipoib_path_iter_read(struct ipoib_path_iter *iter,
              struct ipoib_path *path)
{
    *path = iter->path;
}

#endif /* CONFIG_INFINIBAND_IPOIB_DEBUG */

void ipoib_mark_paths_invalid(struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_path *path, *tp;

    spin_lock_irq(&priv->lock);

    list_for_each_entry_safe(path, tp, &priv->path_list, list) {
        ipoib_dbg(priv, "mark path LID 0x%04x GID %pI6 invalid\n",
            be16_to_cpu(path->pathrec.dlid),
            path->pathrec.dgid.raw);
        path->valid =  0;
    }

    spin_unlock_irq(&priv->lock);
}

void ipoib_flush_paths(struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_path *path, *tp;
    LIST_HEAD(remove_list);
    unsigned long flags;

    netif_tx_lock_bh(dev);
    spin_lock_irqsave(&priv->lock, flags);

    list_splice_init(&priv->path_list, &remove_list);

    list_for_each_entry(path, &remove_list, list)
        rb_erase(&path->rb_node, &priv->path_tree);

    list_for_each_entry_safe(path, tp, &remove_list, list) {
        if (path->query)
            ib_sa_cancel_query(path->query_id, path->query);
        spin_unlock_irqrestore(&priv->lock, flags);
        netif_tx_unlock_bh(dev);
        wait_for_completion(&path->done);
        path_free(dev, path);
        netif_tx_lock_bh(dev);
        spin_lock_irqsave(&priv->lock, flags);
    }

    spin_unlock_irqrestore(&priv->lock, flags);
    netif_tx_unlock_bh(dev);
}

static void path_rec_completion(int status,
                struct ib_sa_path_rec *pathrec,
                void *path_ptr)
{
    struct ipoib_path *path = path_ptr;
    struct net_device *dev = path->dev;
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_ah *ah = NULL;
    struct ipoib_ah *old_ah = NULL;
    struct ipoib_neigh *neigh, *tn;
    struct sk_buff_head skqueue;
    struct sk_buff *skb;
    unsigned long flags;

    if (!status)
        ipoib_dbg(priv, "PathRec LID 0x%04x for GID %pI6\n",
              be16_to_cpu(pathrec->dlid), pathrec->dgid.raw);
    else
        ipoib_dbg(priv, "PathRec status %d for GID %pI6\n",
              status, path->pathrec.dgid.raw);

    skb_queue_head_init(&skqueue);

    if (!status) {
        struct ib_ah_attr av;

        if (!ib_init_ah_from_path(priv->ca, priv->port, pathrec, &av))
            ah = ipoib_create_ah(dev, priv->pd, &av);
    }

    spin_lock_irqsave(&priv->lock, flags);

    if (!IS_ERR_OR_NULL(ah)) {
        path->pathrec = *pathrec;

        old_ah   = path->ah;
        path->ah = ah;

        ipoib_dbg(priv, "created address handle %p for LID 0x%04x, SL %d\n",
              ah, be16_to_cpu(pathrec->dlid), pathrec->sl);

        while ((skb = __skb_dequeue(&path->queue)))
            __skb_queue_tail(&skqueue, skb);

        list_for_each_entry_safe(neigh, tn, &path->neigh_list, list) {
            if (neigh->ah) {
                WARN_ON(neigh->ah != old_ah);
                /*
                 * Dropping the ah reference inside
                 * priv->lock is safe here, because we
                 * will hold one more reference from
                 * the original value of path->ah (ie
                 * old_ah).
                 */
                ipoib_put_ah(neigh->ah);
            }
            kref_get(&path->ah->ref);
            neigh->ah = path->ah;

            if (ipoib_cm_enabled(dev, neigh->daddr)) {
                if (!ipoib_cm_get(neigh))
                    ipoib_cm_set(neigh, ipoib_cm_create_tx(dev,
                                           path,
                                           neigh));
                if (!ipoib_cm_get(neigh)) {
                    list_del(&neigh->list);
                    ipoib_neigh_free(neigh);
                    continue;
                }
            }

            while ((skb = __skb_dequeue(&neigh->queue)))
                __skb_queue_tail(&skqueue, skb);
        }
        path->valid = 1;
    }

    path->query = NULL;
    complete(&path->done);

    spin_unlock_irqrestore(&priv->lock, flags);

    if (old_ah)
        ipoib_put_ah(old_ah);

    while ((skb = __skb_dequeue(&skqueue))) {
        skb->dev = dev;
        if (dev_queue_xmit(skb))
            ipoib_warn(priv, "dev_queue_xmit failed "
                   "to requeue packet\n");
    }
}

static struct ipoib_path *path_rec_create(struct net_device *dev, void *gid)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_path *path;

    if (!priv->broadcast)
        return NULL;

    path = kzalloc(sizeof *path, GFP_ATOMIC);
    if (!path)
        return NULL;

    path->dev = dev;

    skb_queue_head_init(&path->queue);

    INIT_LIST_HEAD(&path->neigh_list);

    memcpy(path->pathrec.dgid.raw, gid, sizeof (union ib_gid));
    path->pathrec.sgid      = priv->local_gid;
    path->pathrec.pkey      = cpu_to_be16(priv->pkey);
    path->pathrec.numb_path     = 1;
    path->pathrec.traffic_class = priv->broadcast->mcmember.traffic_class;

    return path;
}

static int path_rec_start(struct net_device *dev,
              struct ipoib_path *path)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    ipoib_dbg(priv, "Start path record lookup for %pI6\n",
          path->pathrec.dgid.raw);

    init_completion(&path->done);

    path->query_id =
        ib_sa_path_rec_get(&ipoib_sa_client, priv->ca, priv->port,
                   &path->pathrec,
                   IB_SA_PATH_REC_DGID      |
                   IB_SA_PATH_REC_SGID      |
                   IB_SA_PATH_REC_NUMB_PATH |
                   IB_SA_PATH_REC_TRAFFIC_CLASS |
                   IB_SA_PATH_REC_PKEY,
                   1000, GFP_ATOMIC,
                   path_rec_completion,
                   path, &path->query);
    if (path->query_id < 0) {
        ipoib_warn(priv, "ib_sa_path_rec_get failed: %d\n", path->query_id);
        path->query = NULL;
        complete(&path->done);
        return path->query_id;
    }

    return 0;
}

static void neigh_add_path(struct sk_buff *skb, u8 *daddr,
               struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_path *path;
    struct ipoib_neigh *neigh;
    unsigned long flags;

    spin_lock_irqsave(&priv->lock, flags);
    neigh = ipoib_neigh_alloc(daddr, dev);
    if (!neigh) {
        spin_unlock_irqrestore(&priv->lock, flags);
        ++dev->stats.tx_dropped;
        dev_kfree_skb_any(skb);
        return;
    }

    path = __path_find(dev, daddr + 4);
    if (!path) {
        path = path_rec_create(dev, daddr + 4);
        if (!path)
            goto err_path;

        __path_add(dev, path);
    }

    list_add_tail(&neigh->list, &path->neigh_list);

    if (path->ah) {
        kref_get(&path->ah->ref);
        neigh->ah = path->ah;

        if (ipoib_cm_enabled(dev, neigh->daddr)) {
            if (!ipoib_cm_get(neigh))
                ipoib_cm_set(neigh, ipoib_cm_create_tx(dev, path, neigh));
            if (!ipoib_cm_get(neigh)) {
                list_del(&neigh->list);
                ipoib_neigh_free(neigh);
                goto err_drop;
            }
            if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE)
                __skb_queue_tail(&neigh->queue, skb);
            else {
                ipoib_warn(priv, "queue length limit %d. Packet drop.\n",
                       skb_queue_len(&neigh->queue));
                goto err_drop;
            }
        } else {
            spin_unlock_irqrestore(&priv->lock, flags);
            ipoib_send(dev, skb, path->ah, IPOIB_QPN(daddr));
            ipoib_neigh_put(neigh);
            return;
        }
    } else {
        neigh->ah  = NULL;

        if (!path->query && path_rec_start(dev, path))
            goto err_list;

        __skb_queue_tail(&neigh->queue, skb);
    }

    spin_unlock_irqrestore(&priv->lock, flags);
    ipoib_neigh_put(neigh);
    return;

err_list:
    list_del(&neigh->list);

err_path:
    ipoib_neigh_free(neigh);
err_drop:
    ++dev->stats.tx_dropped;
    dev_kfree_skb_any(skb);

    spin_unlock_irqrestore(&priv->lock, flags);
    ipoib_neigh_put(neigh);
}

static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
                 struct ipoib_cb *cb)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_path *path;
    unsigned long flags;

    spin_lock_irqsave(&priv->lock, flags);

    path = __path_find(dev, cb->hwaddr + 4);
    if (!path || !path->valid) {
        int new_path = 0;

        if (!path) {
            path = path_rec_create(dev, cb->hwaddr + 4);
            new_path = 1;
        }
        if (path) {
            __skb_queue_tail(&path->queue, skb);

            if (!path->query && path_rec_start(dev, path)) {
                spin_unlock_irqrestore(&priv->lock, flags);
                if (new_path)
                    path_free(dev, path);
                return;
            } else
                __path_add(dev, path);
        } else {
            ++dev->stats.tx_dropped;
            dev_kfree_skb_any(skb);
        }

        spin_unlock_irqrestore(&priv->lock, flags);
        return;
    }

    if (path->ah) {
        ipoib_dbg(priv, "Send unicast ARP to %04x\n",
              be16_to_cpu(path->pathrec.dlid));

        spin_unlock_irqrestore(&priv->lock, flags);
        ipoib_send(dev, skb, path->ah, IPOIB_QPN(cb->hwaddr));
        return;
    } else if ((path->query || !path_rec_start(dev, path)) &&
           skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
        __skb_queue_tail(&path->queue, skb);
    } else {
        ++dev->stats.tx_dropped;
        dev_kfree_skb_any(skb);
    }

    spin_unlock_irqrestore(&priv->lock, flags);
}

static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_neigh *neigh;
    struct ipoib_cb *cb = (struct ipoib_cb *) skb->cb;
    struct ipoib_header *header;
    unsigned long flags;

    header = (struct ipoib_header *) skb->data;

    if (unlikely(cb->hwaddr[4] == 0xff)) {
        /* multicast, arrange "if" according to probability */
        if ((header->proto != htons(ETH_P_IP)) &&
            (header->proto != htons(ETH_P_IPV6)) &&
            (header->proto != htons(ETH_P_ARP)) &&
            (header->proto != htons(ETH_P_RARP))) {
            /* ethertype not supported by IPoIB */
            ++dev->stats.tx_dropped;
            dev_kfree_skb_any(skb);
            return NETDEV_TX_OK;
        }
        /* Add in the P_Key for multicast*/
        cb->hwaddr[8] = (priv->pkey >> 8) & 0xff;
        cb->hwaddr[9] = priv->pkey & 0xff;

        neigh = ipoib_neigh_get(dev, cb->hwaddr);
        if (likely(neigh))
            goto send_using_neigh;
        ipoib_mcast_send(dev, cb->hwaddr, skb);
        return NETDEV_TX_OK;
    }

    /* unicast, arrange "switch" according to probability */
    switch (header->proto) {
    case htons(ETH_P_IP):
    case htons(ETH_P_IPV6):
        neigh = ipoib_neigh_get(dev, cb->hwaddr);
        if (unlikely(!neigh)) {
            neigh_add_path(skb, cb->hwaddr, dev);
            return NETDEV_TX_OK;
        }
        break;
    case htons(ETH_P_ARP):
    case htons(ETH_P_RARP):
        /* for unicast ARP and RARP should always perform path find */
        unicast_arp_send(skb, dev, cb);
        return NETDEV_TX_OK;
    default:
        /* ethertype not supported by IPoIB */
        ++dev->stats.tx_dropped;
        dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
    }

send_using_neigh:
    /* note we now hold a ref to neigh */
    if (ipoib_cm_get(neigh)) {
        if (ipoib_cm_up(neigh)) {
            ipoib_cm_send(dev, skb, ipoib_cm_get(neigh));
            goto unref;
        }
    } else if (neigh->ah) {
        ipoib_send(dev, skb, neigh->ah, IPOIB_QPN(cb->hwaddr));
        goto unref;
    }

    if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
        spin_lock_irqsave(&priv->lock, flags);
        __skb_queue_tail(&neigh->queue, skb);
        spin_unlock_irqrestore(&priv->lock, flags);
    } else {
        ++dev->stats.tx_dropped;
        dev_kfree_skb_any(skb);
    }

unref:
    ipoib_neigh_put(neigh);

    return NETDEV_TX_OK;
}

static void ipoib_timeout(struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    ipoib_warn(priv, "transmit timeout: latency %d msecs\n",
           jiffies_to_msecs(jiffies - dev->trans_start));
    ipoib_warn(priv, "queue stopped %d, tx_head %u, tx_tail %u\n",
           netif_queue_stopped(dev),
           priv->tx_head, priv->tx_tail);
    /* XXX reset QP, etc. */
}

static int ipoib_hard_header(struct sk_buff *skb,
                 struct net_device *dev,
                 unsigned short type,
                 const void *daddr, const void *saddr, unsigned len)
{
    struct ipoib_header *header;
    struct ipoib_cb *cb = (struct ipoib_cb *) skb->cb;

    header = (struct ipoib_header *) skb_push(skb, sizeof *header);

    header->proto = htons(type);
    header->reserved = 0;

    /*
     * we don't rely on dst_entry structure,  always stuff the
     * destination address into skb->cb so we can figure out where
     * to send the packet later.
     */
    memcpy(cb->hwaddr, daddr, INFINIBAND_ALEN);

    return 0;
}

static void ipoib_set_mcast_list(struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) {
        ipoib_dbg(priv, "IPOIB_FLAG_OPER_UP not set");
        return;
    }

    queue_work(ipoib_workqueue, &priv->restart_task);
}

static u32 ipoib_addr_hash(struct ipoib_neigh_hash *htbl, u8 *daddr)
{
    /*
     * Use only the address parts that contributes to spreading
     * The subnet prefix is not used as one can not connect to
     * same remote port (GUID) using the same remote QPN via two
     * different subnets.
     */
     /* qpn octets[1:4) & port GUID octets[12:20) */
    u32 *daddr_32 = (u32 *) daddr;
    u32 hv;

    hv = jhash_3words(daddr_32[3], daddr_32[4], 0xFFFFFF & daddr_32[0], 0);
    return hv & htbl->mask;
}

struct ipoib_neigh *ipoib_neigh_get(struct net_device *dev, u8 *daddr)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_neigh_table *ntbl = &priv->ntbl;
    struct ipoib_neigh_hash *htbl;
    struct ipoib_neigh *neigh = NULL;
    u32 hash_val;

    rcu_read_lock_bh();

    htbl = rcu_dereference_bh(ntbl->htbl);

    if (!htbl)
        goto out_unlock;

    hash_val = ipoib_addr_hash(htbl, daddr);
    for (neigh = rcu_dereference_bh(htbl->buckets[hash_val]);
         neigh != NULL;
         neigh = rcu_dereference_bh(neigh->hnext)) {
        if (memcmp(daddr, neigh->daddr, INFINIBAND_ALEN) == 0) {
            /* found, take one ref on behalf of the caller */
            if (!atomic_inc_not_zero(&neigh->refcnt)) {
                /* deleted */
                neigh = NULL;
                goto out_unlock;
            }
            neigh->alive = jiffies;
            goto out_unlock;
        }
    }

out_unlock:
    rcu_read_unlock_bh();
    return neigh;
}

static void __ipoib_reap_neigh(struct ipoib_dev_priv *priv)
{
    struct ipoib_neigh_table *ntbl = &priv->ntbl;
    struct ipoib_neigh_hash *htbl;
    unsigned long neigh_obsolete;
    unsigned long dt;
    unsigned long flags;
    int i;

    if (test_bit(IPOIB_STOP_NEIGH_GC, &priv->flags))
        return;

    spin_lock_irqsave(&priv->lock, flags);

    htbl = rcu_dereference_protected(ntbl->htbl,
                     lockdep_is_held(&priv->lock));

    if (!htbl)
        goto out_unlock;

    /* neigh is obsolete if it was idle for two GC periods */
    dt = 2 * arp_tbl.gc_interval;
    neigh_obsolete = jiffies - dt;
    /* handle possible race condition */
    if (test_bit(IPOIB_STOP_NEIGH_GC, &priv->flags))
        goto out_unlock;

    for (i = 0; i < htbl->size; i++) {
        struct ipoib_neigh *neigh;
        struct ipoib_neigh __rcu **np = &htbl->buckets[i];

        while ((neigh = rcu_dereference_protected(*np,
                              lockdep_is_held(&priv->lock))) != NULL) {
            /* was the neigh idle for two GC periods */
            if (time_after(neigh_obsolete, neigh->alive)) {
                rcu_assign_pointer(*np,
                           rcu_dereference_protected(neigh->hnext,
                                         lockdep_is_held(&priv->lock)));
                /* remove from path/mc list */
                list_del(&neigh->list);
                call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
            } else {
                np = &neigh->hnext;
            }

        }
    }

out_unlock:
    spin_unlock_irqrestore(&priv->lock, flags);
}

static void ipoib_reap_neigh(struct work_struct *work)
{
    struct ipoib_dev_priv *priv =
        container_of(work, struct ipoib_dev_priv, neigh_reap_task.work);

    __ipoib_reap_neigh(priv);

    if (!test_bit(IPOIB_STOP_NEIGH_GC, &priv->flags))
        queue_delayed_work(ipoib_workqueue, &priv->neigh_reap_task,
                   arp_tbl.gc_interval);
}


static struct ipoib_neigh *ipoib_neigh_ctor(u8 *daddr,
                      struct net_device *dev)
{
    struct ipoib_neigh *neigh;

    neigh = kzalloc(sizeof *neigh, GFP_ATOMIC);
    if (!neigh)
        return NULL;

    neigh->dev = dev;
    memcpy(&neigh->daddr, daddr, sizeof(neigh->daddr));
    skb_queue_head_init(&neigh->queue);
    INIT_LIST_HEAD(&neigh->list);
    ipoib_cm_set(neigh, NULL);
    /* one ref on behalf of the caller */
    atomic_set(&neigh->refcnt, 1);

    return neigh;
}

struct ipoib_neigh *ipoib_neigh_alloc(u8 *daddr,
                      struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_neigh_table *ntbl = &priv->ntbl;
    struct ipoib_neigh_hash *htbl;
    struct ipoib_neigh *neigh;
    u32 hash_val;

    htbl = rcu_dereference_protected(ntbl->htbl,
                     lockdep_is_held(&priv->lock));
    if (!htbl) {
        neigh = NULL;
        goto out_unlock;
    }

    /* need to add a new neigh, but maybe some other thread succeeded?
     * recalc hash, maybe hash resize took place so we do a search
     */
    hash_val = ipoib_addr_hash(htbl, daddr);
    for (neigh = rcu_dereference_protected(htbl->buckets[hash_val],
                           lockdep_is_held(&priv->lock));
         neigh != NULL;
         neigh = rcu_dereference_protected(neigh->hnext,
                           lockdep_is_held(&priv->lock))) {
        if (memcmp(daddr, neigh->daddr, INFINIBAND_ALEN) == 0) {
            /* found, take one ref on behalf of the caller */
            if (!atomic_inc_not_zero(&neigh->refcnt)) {
                /* deleted */
                neigh = NULL;
                break;
            }
            neigh->alive = jiffies;
            goto out_unlock;
        }
    }

    neigh = ipoib_neigh_ctor(daddr, dev);
    if (!neigh)
        goto out_unlock;

    /* one ref on behalf of the hash table */
    atomic_inc(&neigh->refcnt);
    neigh->alive = jiffies;
    /* put in hash */
    rcu_assign_pointer(neigh->hnext,
               rcu_dereference_protected(htbl->buckets[hash_val],
                             lockdep_is_held(&priv->lock)));
    rcu_assign_pointer(htbl->buckets[hash_val], neigh);
    atomic_inc(&ntbl->entries);

out_unlock:

    return neigh;
}

void ipoib_neigh_dtor(struct ipoib_neigh *neigh)
{
    /* neigh reference count was dropprd to zero */
    struct net_device *dev = neigh->dev;
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct sk_buff *skb;
    if (neigh->ah)
        ipoib_put_ah(neigh->ah);
    while ((skb = __skb_dequeue(&neigh->queue))) {
        ++dev->stats.tx_dropped;
        dev_kfree_skb_any(skb);
    }
    if (ipoib_cm_get(neigh))
        ipoib_cm_destroy_tx(ipoib_cm_get(neigh));
    ipoib_dbg(netdev_priv(dev),
          "neigh free for %06x %pI6\n",
          IPOIB_QPN(neigh->daddr),
          neigh->daddr + 4);
    kfree(neigh);
    if (atomic_dec_and_test(&priv->ntbl.entries)) {
        if (test_bit(IPOIB_NEIGH_TBL_FLUSH, &priv->flags))
            complete(&priv->ntbl.flushed);
    }
}

static void ipoib_neigh_reclaim(struct rcu_head *rp)
{
    /* Called as a result of removal from hash table */
    struct ipoib_neigh *neigh = container_of(rp, struct ipoib_neigh, rcu);
    /* note TX context may hold another ref */
    ipoib_neigh_put(neigh);
}

void ipoib_neigh_free(struct ipoib_neigh *neigh)
{
    struct net_device *dev = neigh->dev;
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_neigh_table *ntbl = &priv->ntbl;
    struct ipoib_neigh_hash *htbl;
    struct ipoib_neigh __rcu **np;
    struct ipoib_neigh *n;
    u32 hash_val;

    htbl = rcu_dereference_protected(ntbl->htbl,
                    lockdep_is_held(&priv->lock));
    if (!htbl)
        return;

    hash_val = ipoib_addr_hash(htbl, neigh->daddr);
    np = &htbl->buckets[hash_val];
    for (n = rcu_dereference_protected(*np,
                        lockdep_is_held(&priv->lock));
         n != NULL;
         n = rcu_dereference_protected(*np,
                    lockdep_is_held(&priv->lock))) {
        if (n == neigh) {
            /* found */
            rcu_assign_pointer(*np,
                       rcu_dereference_protected(neigh->hnext,
                                     lockdep_is_held(&priv->lock)));
            call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
            return;
        } else {
            np = &n->hnext;
        }
    }
}

static int ipoib_neigh_hash_init(struct ipoib_dev_priv *priv)
{
    struct ipoib_neigh_table *ntbl = &priv->ntbl;
    struct ipoib_neigh_hash *htbl;
    struct ipoib_neigh **buckets;
    u32 size;

    clear_bit(IPOIB_NEIGH_TBL_FLUSH, &priv->flags);
    ntbl->htbl = NULL;
    htbl = kzalloc(sizeof(*htbl), GFP_KERNEL);
    if (!htbl)
        return -ENOMEM;
    set_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);
    size = roundup_pow_of_two(arp_tbl.gc_thresh3);
    buckets = kzalloc(size * sizeof(*buckets), GFP_KERNEL);
    if (!buckets) {
        kfree(htbl);
        return -ENOMEM;
    }
    htbl->size = size;
    htbl->mask = (size - 1);
    htbl->buckets = buckets;
    ntbl->htbl = htbl;
    htbl->ntbl = ntbl;
    atomic_set(&ntbl->entries, 0);

    /* start garbage collection */
    clear_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);
    queue_delayed_work(ipoib_workqueue, &priv->neigh_reap_task,
               arp_tbl.gc_interval);

    return 0;
}

static void neigh_hash_free_rcu(struct rcu_head *head)
{
    struct ipoib_neigh_hash *htbl = container_of(head,
                            struct ipoib_neigh_hash,
                            rcu);
    struct ipoib_neigh __rcu **buckets = htbl->buckets;
    struct ipoib_neigh_table *ntbl = htbl->ntbl;

    kfree(buckets);
    kfree(htbl);
    complete(&ntbl->deleted);
}

void ipoib_del_neighs_by_gid(struct net_device *dev, u8 *gid)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    struct ipoib_neigh_table *ntbl = &priv->ntbl;
    struct ipoib_neigh_hash *htbl;
    unsigned long flags;
    int i;

    /* remove all neigh connected to a given path or mcast */
    spin_lock_irqsave(&priv->lock, flags);

    htbl = rcu_dereference_protected(ntbl->htbl,
                     lockdep_is_held(&priv->lock));

    if (!htbl)
        goto out_unlock;

    for (i = 0; i < htbl->size; i++) {
        struct ipoib_neigh *neigh;
        struct ipoib_neigh __rcu **np = &htbl->buckets[i];

        while ((neigh = rcu_dereference_protected(*np,
                              lockdep_is_held(&priv->lock))) != NULL) {
            /* delete neighs belong to this parent */
            if (!memcmp(gid, neigh->daddr + 4, sizeof (union ib_gid))) {
                rcu_assign_pointer(*np,
                           rcu_dereference_protected(neigh->hnext,
                                         lockdep_is_held(&priv->lock)));
                /* remove from parent list */
                list_del(&neigh->list);
                call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
            } else {
                np = &neigh->hnext;
            }

        }
    }
out_unlock:
    spin_unlock_irqrestore(&priv->lock, flags);
}

static void ipoib_flush_neighs(struct ipoib_dev_priv *priv)
{
    struct ipoib_neigh_table *ntbl = &priv->ntbl;
    struct ipoib_neigh_hash *htbl;
    unsigned long flags;
    int i, wait_flushed = 0;

    init_completion(&priv->ntbl.flushed);

    spin_lock_irqsave(&priv->lock, flags);

    htbl = rcu_dereference_protected(ntbl->htbl,
                    lockdep_is_held(&priv->lock));
    if (!htbl)
        goto out_unlock;

    wait_flushed = atomic_read(&priv->ntbl.entries);
    if (!wait_flushed)
        goto free_htbl;

    for (i = 0; i < htbl->size; i++) {
        struct ipoib_neigh *neigh;
        struct ipoib_neigh __rcu **np = &htbl->buckets[i];

        while ((neigh = rcu_dereference_protected(*np,
                       lockdep_is_held(&priv->lock))) != NULL) {
            rcu_assign_pointer(*np,
                       rcu_dereference_protected(neigh->hnext,
                                     lockdep_is_held(&priv->lock)));
            /* remove from path/mc list */
            list_del(&neigh->list);
            call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
        }
    }

free_htbl:
    rcu_assign_pointer(ntbl->htbl, NULL);
    call_rcu(&htbl->rcu, neigh_hash_free_rcu);

out_unlock:
    spin_unlock_irqrestore(&priv->lock, flags);
    if (wait_flushed)
        wait_for_completion(&priv->ntbl.flushed);
}

static void ipoib_neigh_hash_uninit(struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);
    int stopped;

    ipoib_dbg(priv, "ipoib_neigh_hash_uninit\n");
    init_completion(&priv->ntbl.deleted);
    set_bit(IPOIB_NEIGH_TBL_FLUSH, &priv->flags);

    /* Stop GC if called at init fail need to cancel work */
    stopped = test_and_set_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);
    if (!stopped)
        cancel_delayed_work(&priv->neigh_reap_task);

    ipoib_flush_neighs(priv);

    wait_for_completion(&priv->ntbl.deleted);
}


int ipoib_dev_init(struct net_device *dev, struct ib_device *ca, int port)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    if (ipoib_neigh_hash_init(priv) < 0)
        goto out;
    /* Allocate RX/TX "rings" to hold queued skbs */
    priv->rx_ring = kzalloc(ipoib_recvq_size * sizeof *priv->rx_ring,
                GFP_KERNEL);
    if (!priv->rx_ring) {
        printk(KERN_WARNING "%s: failed to allocate RX ring (%d entries)\n",
               ca->name, ipoib_recvq_size);
        goto out_neigh_hash_cleanup;
    }

    priv->tx_ring = vzalloc(ipoib_sendq_size * sizeof *priv->tx_ring);
    if (!priv->tx_ring) {
        printk(KERN_WARNING "%s: failed to allocate TX ring (%d entries)\n",
               ca->name, ipoib_sendq_size);
        goto out_rx_ring_cleanup;
    }

    /* priv->tx_head, tx_tail & tx_outstanding are already 0 */

    if (ipoib_ib_dev_init(dev, ca, port))
        goto out_tx_ring_cleanup;

    return 0;

out_tx_ring_cleanup:
    vfree(priv->tx_ring);

out_rx_ring_cleanup:
    kfree(priv->rx_ring);

out_neigh_hash_cleanup:
    ipoib_neigh_hash_uninit(dev);
out:
    return -ENOMEM;
}

void ipoib_dev_cleanup(struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev), *cpriv, *tcpriv;
    LIST_HEAD(head);

    ASSERT_RTNL();

    ipoib_delete_debug_files(dev);

    /* Delete any child interfaces first */
    list_for_each_entry_safe(cpriv, tcpriv, &priv->child_intfs, list) {
        /* Stop GC on child */
        set_bit(IPOIB_STOP_NEIGH_GC, &cpriv->flags);
        cancel_delayed_work(&cpriv->neigh_reap_task);
        unregister_netdevice_queue(cpriv->dev, &head);
    }
    unregister_netdevice_many(&head);

    ipoib_ib_dev_cleanup(dev);

    kfree(priv->rx_ring);
    vfree(priv->tx_ring);

    priv->rx_ring = NULL;
    priv->tx_ring = NULL;

    ipoib_neigh_hash_uninit(dev);
}

static const struct header_ops ipoib_header_ops = {
    .create = ipoib_hard_header,
};

static const struct net_device_ops ipoib_netdev_ops = {
    .ndo_uninit      = ipoib_uninit,
    .ndo_open        = ipoib_open,
    .ndo_stop        = ipoib_stop,
    .ndo_change_mtu      = ipoib_change_mtu,
    .ndo_fix_features    = ipoib_fix_features,
    .ndo_start_xmit      = ipoib_start_xmit,
    .ndo_tx_timeout      = ipoib_timeout,
    .ndo_set_rx_mode     = ipoib_set_mcast_list,
};

void ipoib_setup(struct net_device *dev)
{
    struct ipoib_dev_priv *priv = netdev_priv(dev);

    dev->netdev_ops      = &ipoib_netdev_ops;
    dev->header_ops      = &ipoib_header_ops;

    ipoib_set_ethtool_ops(dev);

    netif_napi_add(dev, &priv->napi, ipoib_poll, 100);

    dev->watchdog_timeo  = HZ;

    dev->flags      |= IFF_BROADCAST | IFF_MULTICAST;

    dev->hard_header_len     = IPOIB_ENCAP_LEN;
    dev->addr_len        = INFINIBAND_ALEN;
    dev->type        = ARPHRD_INFINIBAND;
    dev->tx_queue_len    = ipoib_sendq_size * 2;
    dev->features        = (NETIF_F_VLAN_CHALLENGED |
                    NETIF_F_HIGHDMA);
    dev->priv_flags     &= ~IFF_XMIT_DST_RELEASE;

    memcpy(dev->broadcast, ipv4_bcast_addr, INFINIBAND_ALEN);

    netif_carrier_off(dev);

    priv->dev = dev;

    spin_lock_init(&priv->lock);

    mutex_init(&priv->vlan_mutex);

    INIT_LIST_HEAD(&priv->path_list);
    INIT_LIST_HEAD(&priv->child_intfs);
    INIT_LIST_HEAD(&priv->dead_ahs);
    INIT_LIST_HEAD(&priv->multicast_list);

    INIT_DELAYED_WORK(&priv->pkey_poll_task, ipoib_pkey_poll);
    INIT_DELAYED_WORK(&priv->mcast_task,   ipoib_mcast_join_task);
    INIT_WORK(&priv->carrier_on_task, ipoib_mcast_carrier_on_task);
    INIT_WORK(&priv->flush_light,   ipoib_ib_dev_flush_light);
    INIT_WORK(&priv->flush_normal,   ipoib_ib_dev_flush_normal);
    INIT_WORK(&priv->flush_heavy,   ipoib_ib_dev_flush_heavy);
    INIT_WORK(&priv->restart_task, ipoib_mcast_restart_task);
    INIT_DELAYED_WORK(&priv->ah_reap_task, ipoib_reap_ah);
    INIT_DELAYED_WORK(&priv->neigh_reap_task, ipoib_reap_neigh);
}

struct ipoib_dev_priv *ipoib_intf_alloc(const char *name)
{
    struct net_device *dev;

    dev = alloc_netdev((int) sizeof (struct ipoib_dev_priv), name,
               ipoib_setup);
    if (!dev)
        return NULL;

    return netdev_priv(dev);
}

static ssize_t show_pkey(struct device *dev,
             struct device_attribute *attr, char *buf)
{
    struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(dev));

    return sprintf(buf, "0x%04x\n", priv->pkey);
}
static DEVICE_ATTR(pkey, S_IRUGO, show_pkey, NULL);

static ssize_t show_umcast(struct device *dev,
               struct device_attribute *attr, char *buf)
{
    struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(dev));

    return sprintf(buf, "%d\n", test_bit(IPOIB_FLAG_UMCAST, &priv->flags));
}

void ipoib_set_umcast(struct net_device *ndev, int umcast_val)
{
    struct ipoib_dev_priv *priv = netdev_priv(ndev);

    if (umcast_val > 0) {
        set_bit(IPOIB_FLAG_UMCAST, &priv->flags);
        ipoib_warn(priv, "ignoring multicast groups joined directly "
                "by userspace\n");
    } else
        clear_bit(IPOIB_FLAG_UMCAST, &priv->flags);
}

static ssize_t set_umcast(struct device *dev,
              struct device_attribute *attr,
              const char *buf, size_t count)
{
    unsigned long umcast_val = simple_strtoul(buf, NULL, 0);

    ipoib_set_umcast(to_net_dev(dev), umcast_val);

    return count;
}
static DEVICE_ATTR(umcast, S_IWUSR | S_IRUGO, show_umcast, set_umcast);

int ipoib_add_umcast_attr(struct net_device *dev)
{
    return device_create_file(&dev->dev, &dev_attr_umcast);
}

static ssize_t create_child(struct device *dev,
                struct device_attribute *attr,
                const char *buf, size_t count)
{
    int pkey;
    int ret;

    if (sscanf(buf, "%i", &pkey) != 1)
        return -EINVAL;

    if (pkey < 0 || pkey > 0xffff)
        return -EINVAL;

    /*
     * Set the full membership bit, so that we join the right
     * broadcast group, etc.
     */
    pkey |= 0x8000;

    ret = ipoib_vlan_add(to_net_dev(dev), pkey);

    return ret ? ret : count;
}
static DEVICE_ATTR(create_child, S_IWUSR, NULL, create_child);

static ssize_t delete_child(struct device *dev,
                struct device_attribute *attr,
                const char *buf, size_t count)
{
    int pkey;
    int ret;

    if (sscanf(buf, "%i", &pkey) != 1)
        return -EINVAL;

    if (pkey < 0 || pkey > 0xffff)
        return -EINVAL;

    ret = ipoib_vlan_delete(to_net_dev(dev), pkey);

    return ret ? ret : count;

}
static DEVICE_ATTR(delete_child, S_IWUSR, NULL, delete_child);

int ipoib_add_pkey_attr(struct net_device *dev)
{
    return device_create_file(&dev->dev, &dev_attr_pkey);
}

int ipoib_set_dev_features(struct ipoib_dev_priv *priv, struct ib_device *hca)
{
    struct ib_device_attr *device_attr;
    int result = -ENOMEM;

    device_attr = kmalloc(sizeof *device_attr, GFP_KERNEL);
    if (!device_attr) {
        printk(KERN_WARNING "%s: allocation of %zu bytes failed\n",
               hca->name, sizeof *device_attr);
        return result;
    }

    result = ib_query_device(hca, device_attr);
    if (result) {
        printk(KERN_WARNING "%s: ib_query_device failed (ret = %d)\n",
               hca->name, result);
        kfree(device_attr);
        return result;
    }
    priv->hca_caps = device_attr->device_cap_flags;

    kfree(device_attr);

    if (priv->hca_caps & IB_DEVICE_UD_IP_CSUM) {
        priv->dev->hw_features = NETIF_F_SG |
            NETIF_F_IP_CSUM | NETIF_F_RXCSUM;

        if (priv->hca_caps & IB_DEVICE_UD_TSO)
            priv->dev->hw_features |= NETIF_F_TSO;

        priv->dev->features |= priv->dev->hw_features;
    }

    return 0;
}

static struct net_device *ipoib_add_port(const char *format,
                     struct ib_device *hca, u8 port)
{
    struct ipoib_dev_priv *priv;
    struct ib_port_attr attr;
    int result = -ENOMEM;

    priv = ipoib_intf_alloc(format);
    if (!priv)
        goto alloc_mem_failed;

    SET_NETDEV_DEV(priv->dev, hca->dma_device);
    priv->dev->dev_id = port - 1;

    if (!ib_query_port(hca, port, &attr))
        priv->max_ib_mtu = ib_mtu_enum_to_int(attr.max_mtu);
    else {
        printk(KERN_WARNING "%s: ib_query_port %d failed\n",
               hca->name, port);
        goto device_init_failed;
    }

    /* MTU will be reset when mcast join happens */
    priv->dev->mtu  = IPOIB_UD_MTU(priv->max_ib_mtu);
    priv->mcast_mtu  = priv->admin_mtu = priv->dev->mtu;

    priv->dev->neigh_priv_len = sizeof(struct ipoib_neigh);

    result = ib_query_pkey(hca, port, 0, &priv->pkey);
    if (result) {
        printk(KERN_WARNING "%s: ib_query_pkey port %d failed (ret = %d)\n",
               hca->name, port, result);
        goto device_init_failed;
    }

    if (ipoib_set_dev_features(priv, hca))
        goto device_init_failed;

    /*
     * Set the full membership bit, so that we join the right
     * broadcast group, etc.
     */
    priv->pkey |= 0x8000;

    priv->dev->broadcast[8] = priv->pkey >> 8;
    priv->dev->broadcast[9] = priv->pkey & 0xff;

    result = ib_query_gid(hca, port, 0, &priv->local_gid);
    if (result) {
        printk(KERN_WARNING "%s: ib_query_gid port %d failed (ret = %d)\n",
               hca->name, port, result);
        goto device_init_failed;
    } else
        memcpy(priv->dev->dev_addr + 4, priv->local_gid.raw, sizeof (union ib_gid));

    result = ipoib_dev_init(priv->dev, hca, port);
    if (result < 0) {
        printk(KERN_WARNING "%s: failed to initialize port %d (ret = %d)\n",
               hca->name, port, result);
        goto device_init_failed;
    }

    INIT_IB_EVENT_HANDLER(&priv->event_handler,
                  priv->ca, ipoib_event);
    result = ib_register_event_handler(&priv->event_handler);
    if (result < 0) {
        printk(KERN_WARNING "%s: ib_register_event_handler failed for "
               "port %d (ret = %d)\n",
               hca->name, port, result);
        goto event_failed;
    }

    result = register_netdev(priv->dev);
    if (result) {
        printk(KERN_WARNING "%s: couldn't register ipoib port %d; error %d\n",
               hca->name, port, result);
        goto register_failed;
    }

    ipoib_create_debug_files(priv->dev);

    if (ipoib_cm_add_mode_attr(priv->dev))
        goto sysfs_failed;
    if (ipoib_add_pkey_attr(priv->dev))
        goto sysfs_failed;
    if (ipoib_add_umcast_attr(priv->dev))
        goto sysfs_failed;
    if (device_create_file(&priv->dev->dev, &dev_attr_create_child))
        goto sysfs_failed;
    if (device_create_file(&priv->dev->dev, &dev_attr_delete_child))
        goto sysfs_failed;

    return priv->dev;

sysfs_failed:
    ipoib_delete_debug_files(priv->dev);
    unregister_netdev(priv->dev);

register_failed:
    ib_unregister_event_handler(&priv->event_handler);
    /* Stop GC if started before flush */
    set_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);
    cancel_delayed_work(&priv->neigh_reap_task);
    flush_workqueue(ipoib_workqueue);

event_failed:
    ipoib_dev_cleanup(priv->dev);

device_init_failed:
    free_netdev(priv->dev);

alloc_mem_failed:
    return ERR_PTR(result);
}

static void ipoib_add_one(struct ib_device *device)
{
    struct list_head *dev_list;
    struct net_device *dev;
    struct ipoib_dev_priv *priv;
    int s, e, p;

    if (rdma_node_get_transport(device->node_type) != RDMA_TRANSPORT_IB)
        return;

    dev_list = kmalloc(sizeof *dev_list, GFP_KERNEL);
    if (!dev_list)
        return;

    INIT_LIST_HEAD(dev_list);

    if (device->node_type == RDMA_NODE_IB_SWITCH) {
        s = 0;
        e = 0;
    } else {
        s = 1;
        e = device->phys_port_cnt;
    }

    for (p = s; p <= e; ++p) {
        if (rdma_port_get_link_layer(device, p) != IB_LINK_LAYER_INFINIBAND)
            continue;
        dev = ipoib_add_port("ib%d", device, p);
        if (!IS_ERR(dev)) {
            priv = netdev_priv(dev);
            list_add_tail(&priv->list, dev_list);
        }
    }

    ib_set_client_data(device, &ipoib_client, dev_list);
}

static void ipoib_remove_one(struct ib_device *device)
{
    struct ipoib_dev_priv *priv, *tmp;
    struct list_head *dev_list;

    if (rdma_node_get_transport(device->node_type) != RDMA_TRANSPORT_IB)
        return;

    dev_list = ib_get_client_data(device, &ipoib_client);

    list_for_each_entry_safe(priv, tmp, dev_list, list) {
        ib_unregister_event_handler(&priv->event_handler);

        rtnl_lock();
        dev_change_flags(priv->dev, priv->dev->flags & ~IFF_UP);
        rtnl_unlock();

        /* Stop GC */
        set_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);
        cancel_delayed_work(&priv->neigh_reap_task);
        flush_workqueue(ipoib_workqueue);

        unregister_netdev(priv->dev);
        free_netdev(priv->dev);
    }

    kfree(dev_list);
}

static int __init ipoib_init_module(void)
{
    int ret;

    ipoib_recvq_size = roundup_pow_of_two(ipoib_recvq_size);
    ipoib_recvq_size = min(ipoib_recvq_size, IPOIB_MAX_QUEUE_SIZE);
    ipoib_recvq_size = max(ipoib_recvq_size, IPOIB_MIN_QUEUE_SIZE);

    ipoib_sendq_size = roundup_pow_of_two(ipoib_sendq_size);
    ipoib_sendq_size = min(ipoib_sendq_size, IPOIB_MAX_QUEUE_SIZE);
    ipoib_sendq_size = max3(ipoib_sendq_size, 2 * MAX_SEND_CQE, IPOIB_MIN_QUEUE_SIZE);
#ifdef CONFIG_INFINIBAND_IPOIB_CM
    ipoib_max_conn_qp = min(ipoib_max_conn_qp, IPOIB_CM_MAX_CONN_QP);
#endif

    /*
     * When copying small received packets, we only copy from the
     * linear data part of the SKB, so we rely on this condition.
     */
    BUILD_BUG_ON(IPOIB_CM_COPYBREAK > IPOIB_CM_HEAD_SIZE);

    ret = ipoib_register_debugfs();
    if (ret)
        return ret;

    /*
     * We create our own workqueue mainly because we want to be
     * able to flush it when devices are being removed.  We can't
     * use schedule_work()/flush_scheduled_work() because both
     * unregister_netdev() and linkwatch_event take the rtnl lock,
     * so flush_scheduled_work() can deadlock during device
     * removal.
     */
    ipoib_workqueue = create_singlethread_workqueue("ipoib");
    if (!ipoib_workqueue) {
        ret = -ENOMEM;
        goto err_fs;
    }

    ib_sa_register_client(&ipoib_sa_client);

    ret = ib_register_client(&ipoib_client);
    if (ret)
        goto err_sa;

    ret = ipoib_netlink_init();
    if (ret)
        goto err_client;

    return 0;

err_client:
    ib_unregister_client(&ipoib_client);

err_sa:
    ib_sa_unregister_client(&ipoib_sa_client);
    destroy_workqueue(ipoib_workqueue);

err_fs:
    ipoib_unregister_debugfs();

    return ret;
}

static void __exit ipoib_cleanup_module(void)
{
    ipoib_netlink_fini();
    ib_unregister_client(&ipoib_client);
    ib_sa_unregister_client(&ipoib_sa_client);
    ipoib_unregister_debugfs();
    destroy_workqueue(ipoib_workqueue);
}

module_init(ipoib_init_module);
module_exit(ipoib_cleanup_module);