Merge tag 'sound-fix-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai...

[mirror_ubuntu-disco-kernel.git] / drivers / infiniband / ulp / ipoib / ipoib_main.c

/*
 * 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>
#include <net/addrconf.h>
#include <linux/inetdevice.h>
#include <rdma/ib_cache.h>
#include <linux/pci.h>

#define DRV_VERSION "1.0.0"

const char ipoib_driver_version[] = DRV_VERSION;

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

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, void *client_data);
static void ipoib_neigh_reclaim(struct rcu_head *rp);
static struct net_device *ipoib_get_net_dev_by_params(
                struct ib_device *dev, u8 port, u16 pkey,
                const union ib_gid *gid, const struct sockaddr *addr,
                void *client_data);
static int ipoib_set_mac(struct net_device *dev, void *addr);

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

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

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

        netif_carrier_off(dev);

        set_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags);

        priv->sm_fullmember_sendonly_support = false;

        if (ipoib_ib_dev_open(dev)) {
                if (!test_bit(IPOIB_PKEY_ASSIGNED, &priv->flags))
                        return 0;
                goto err_disable;
        }

        ipoib_ib_dev_up(dev);

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

                /* Bring up any child interfaces too */
                down_read(&priv->vlan_rwsem);
                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);
                }
                up_read(&priv->vlan_rwsem);
        }

        netif_start_queue(dev);

        return 0;

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);
        ipoib_ib_dev_stop(dev);

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

                /* Bring down any child interfaces too */
                down_read(&priv->vlan_rwsem);
                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);
                }
                up_read(&priv->vlan_rwsem);
        }

        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_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;

        if (priv->mcast_mtu < priv->admin_mtu)
                ipoib_dbg(priv, "MTU must be smaller than the underlying "
                                "link layer MTU - 4 (%u)\n", priv->mcast_mtu);

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

        return 0;
}

/* Called with an RCU read lock taken */
static bool ipoib_is_dev_match_addr_rcu(const struct sockaddr *addr,
                                        struct net_device *dev)
{
        struct net *net = dev_net(dev);
        struct in_device *in_dev;
        struct sockaddr_in *addr_in = (struct sockaddr_in *)addr;
        struct sockaddr_in6 *addr_in6 = (struct sockaddr_in6 *)addr;
        __be32 ret_addr;

        switch (addr->sa_family) {
        case AF_INET:
                in_dev = in_dev_get(dev);
                if (!in_dev)
                        return false;

                ret_addr = inet_confirm_addr(net, in_dev, 0,
                                             addr_in->sin_addr.s_addr,
                                             RT_SCOPE_HOST);
                in_dev_put(in_dev);
                if (ret_addr)
                        return true;

                break;
        case AF_INET6:
                if (IS_ENABLED(CONFIG_IPV6) &&
                    ipv6_chk_addr(net, &addr_in6->sin6_addr, dev, 1))
                        return true;

                break;
        }
        return false;
}

/**
 * Find the master net_device on top of the given net_device.
 * @dev: base IPoIB net_device
 *
 * Returns the master net_device with a reference held, or the same net_device
 * if no master exists.
 */
static struct net_device *ipoib_get_master_net_dev(struct net_device *dev)
{
        struct net_device *master;

        rcu_read_lock();
        master = netdev_master_upper_dev_get_rcu(dev);
        if (master)
                dev_hold(master);
        rcu_read_unlock();

        if (master)
                return master;

        dev_hold(dev);
        return dev;
}

struct ipoib_walk_data {
        const struct sockaddr *addr;
        struct net_device *result;
};

static int ipoib_upper_walk(struct net_device *upper, void *_data)
{
        struct ipoib_walk_data *data = _data;
        int ret = 0;

        if (ipoib_is_dev_match_addr_rcu(data->addr, upper)) {
                dev_hold(upper);
                data->result = upper;
                ret = 1;
        }

        return ret;
}

/**
 * Find a net_device matching the given address, which is an upper device of
 * the given net_device.
 * @addr: IP address to look for.
 * @dev: base IPoIB net_device
 *
 * If found, returns the net_device with a reference held. Otherwise return
 * NULL.
 */
static struct net_device *ipoib_get_net_dev_match_addr(
                const struct sockaddr *addr, struct net_device *dev)
{
        struct ipoib_walk_data data = {
                .addr = addr,
        };

        rcu_read_lock();
        if (ipoib_is_dev_match_addr_rcu(addr, dev)) {
                dev_hold(dev);
                data.result = dev;
                goto out;
        }

        netdev_walk_all_upper_dev_rcu(dev, ipoib_upper_walk, &data);
out:
        rcu_read_unlock();
        return data.result;
}

/* returns the number of IPoIB netdevs on top a given ipoib device matching a
 * pkey_index and address, if one exists.
 *
 * @found_net_dev: contains a matching net_device if the return value >= 1,
 * with a reference held. */
static int ipoib_match_gid_pkey_addr(struct ipoib_dev_priv *priv,
                                     const union ib_gid *gid,
                                     u16 pkey_index,
                                     const struct sockaddr *addr,
                                     int nesting,
                                     struct net_device **found_net_dev)
{
        struct ipoib_dev_priv *child_priv;
        struct net_device *net_dev = NULL;
        int matches = 0;

        if (priv->pkey_index == pkey_index &&
            (!gid || !memcmp(gid, &priv->local_gid, sizeof(*gid)))) {
                if (!addr) {
                        net_dev = ipoib_get_master_net_dev(priv->dev);
                } else {
                        /* Verify the net_device matches the IP address, as
                         * IPoIB child devices currently share a GID. */
                        net_dev = ipoib_get_net_dev_match_addr(addr, priv->dev);
                }
                if (net_dev) {
                        if (!*found_net_dev)
                                *found_net_dev = net_dev;
                        else
                                dev_put(net_dev);
                        ++matches;
                }
        }

        /* Check child interfaces */
        down_read_nested(&priv->vlan_rwsem, nesting);
        list_for_each_entry(child_priv, &priv->child_intfs, list) {
                matches += ipoib_match_gid_pkey_addr(child_priv, gid,
                                                    pkey_index, addr,
                                                    nesting + 1,
                                                    found_net_dev);
                if (matches > 1)
                        break;
        }
        up_read(&priv->vlan_rwsem);

        return matches;
}

/* Returns the number of matching net_devs found (between 0 and 2). Also
 * return the matching net_device in the @net_dev parameter, holding a
 * reference to the net_device, if the number of matches >= 1 */
static int __ipoib_get_net_dev_by_params(struct list_head *dev_list, u8 port,
                                         u16 pkey_index,
                                         const union ib_gid *gid,
                                         const struct sockaddr *addr,
                                         struct net_device **net_dev)
{
        struct ipoib_dev_priv *priv;
        int matches = 0;

        *net_dev = NULL;

        list_for_each_entry(priv, dev_list, list) {
                if (priv->port != port)
                        continue;

                matches += ipoib_match_gid_pkey_addr(priv, gid, pkey_index,
                                                     addr, 0, net_dev);
                if (matches > 1)
                        break;
        }

        return matches;
}

static struct net_device *ipoib_get_net_dev_by_params(
                struct ib_device *dev, u8 port, u16 pkey,
                const union ib_gid *gid, const struct sockaddr *addr,
                void *client_data)
{
        struct net_device *net_dev;
        struct list_head *dev_list = client_data;
        u16 pkey_index;
        int matches;
        int ret;

        if (!rdma_protocol_ib(dev, port))
                return NULL;

        ret = ib_find_cached_pkey(dev, port, pkey, &pkey_index);
        if (ret)
                return NULL;

        if (!dev_list)
                return NULL;

        /* See if we can find a unique device matching the L2 parameters */
        matches = __ipoib_get_net_dev_by_params(dev_list, port, pkey_index,
                                                gid, NULL, &net_dev);

        switch (matches) {
        case 0:
                return NULL;
        case 1:
                return net_dev;
        }

        dev_put(net_dev);

        /* Couldn't find a unique device with L2 parameters only. Use L3
         * address to uniquely match the net device */
        matches = __ipoib_get_net_dev_by_params(dev_list, port, pkey_index,
                                                gid, addr, &net_dev);
        switch (matches) {
        case 0:
                return NULL;
        default:
                dev_warn_ratelimited(&dev->dev,
                                     "duplicate IP address detected\n");
                /* Fall through */
        case 1:
                return net_dev;
        }
}

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

        if ((test_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags) &&
             !strcmp(buf, "connected\n")) ||
             (!test_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags) &&
             !strcmp(buf, "datagram\n"))) {
                return 0;
        }

        /* 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);
                dev_set_mtu(dev, ipoib_cm_max_mtu(dev));
                rtnl_unlock();
                priv->tx_wr.wr.send_flags &= ~IB_SEND_IP_CSUM;

                ipoib_flush_paths(dev);
                return (!rtnl_trylock()) ? -EBUSY : 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);
                return (!rtnl_trylock()) ? -EBUSY : 0;
        }

        return -EINVAL;
}

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);
}

struct classport_info_context {
        struct ipoib_dev_priv   *priv;
        struct completion       done;
        struct ib_sa_query      *sa_query;
};

static void classport_info_query_cb(int status, struct ib_class_port_info *rec,
                                    void *context)
{
        struct classport_info_context *cb_ctx = context;
        struct ipoib_dev_priv *priv;

        WARN_ON(!context);

        priv = cb_ctx->priv;

        if (status || !rec) {
                pr_debug("device: %s failed query classport_info status: %d\n",
                         priv->dev->name, status);
                /* keeps the default, will try next mcast_restart */
                priv->sm_fullmember_sendonly_support = false;
                goto out;
        }

        if (ib_get_cpi_capmask2(rec) &
            IB_SA_CAP_MASK2_SENDONLY_FULL_MEM_SUPPORT) {
                pr_debug("device: %s enabled fullmember-sendonly for sendonly MCG\n",
                         priv->dev->name);
                priv->sm_fullmember_sendonly_support = true;
        } else {
                pr_debug("device: %s disabled fullmember-sendonly for sendonly MCG\n",
                         priv->dev->name);
                priv->sm_fullmember_sendonly_support = false;
        }

out:
        complete(&cb_ctx->done);
}

int ipoib_check_sm_sendonly_fullmember_support(struct ipoib_dev_priv *priv)
{
        struct classport_info_context *callback_context;
        int ret;

        callback_context = kmalloc(sizeof(*callback_context), GFP_KERNEL);
        if (!callback_context)
                return -ENOMEM;

        callback_context->priv = priv;
        init_completion(&callback_context->done);

        ret = ib_sa_classport_info_rec_query(&ipoib_sa_client,
                                             priv->ca, priv->port, 3000,
                                             GFP_KERNEL,
                                             classport_info_query_cb,
                                             callback_context,
                                             &callback_context->sa_query);
        if (ret < 0) {
                pr_info("%s failed to send ib_sa_classport_info query, ret: %d\n",
                        priv->dev->name, ret);
                kfree(callback_context);
                return ret;
        }

        /* waiting for the callback to finish before returnning */
        wait_for_completion(&callback_context->done);
        kfree(callback_context);

        return ret;
}

static void push_pseudo_header(struct sk_buff *skb, const char *daddr)
{
        struct ipoib_pseudo_header *phdr;

        phdr = (struct ipoib_pseudo_header *)skb_push(skb, sizeof(*phdr));
        memcpy(phdr->hwaddr, daddr, INFINIBAND_ALEN);
}

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)) {
                                        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 (IS_ERR_OR_NULL(ah))
                ipoib_del_neighs_by_gid(dev, path->pathrec.dgid.raw);

        if (old_ah)
                ipoib_put_ah(old_ah);

        while ((skb = __skb_dequeue(&skqueue))) {
                int ret;
                skb->dev = dev;
                ret = dev_queue_xmit(skb);
                if (ret)
                        ipoib_warn(priv, "%s: dev_queue_xmit failed to re-queue packet, ret:%d\n",
                                   __func__, ret);
        }
}

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)) {
                                ipoib_neigh_free(neigh);
                                goto err_drop;
                        }
                        if (skb_queue_len(&neigh->queue) <
                            IPOIB_MAX_PATH_REC_QUEUE) {
                                push_pseudo_header(skb, neigh->daddr);
                                __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_path;
                if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
                        push_pseudo_header(skb, neigh->daddr);
                        __skb_queue_tail(&neigh->queue, skb);
                } else {
                        goto err_drop;
                }
        }

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

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_pseudo_header *phdr)
{
        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, phdr->hwaddr + 4);
        if (!path || !path->valid) {
                int new_path = 0;

                if (!path) {
                        path = path_rec_create(dev, phdr->hwaddr + 4);
                        new_path = 1;
                }
                if (path) {
                        if (skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
                                push_pseudo_header(skb, phdr->hwaddr);
                                __skb_queue_tail(&path->queue, skb);
                        } else {
                                ++dev->stats.tx_dropped;
                                dev_kfree_skb_any(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(phdr->hwaddr));
                return;
        } else if ((path->query || !path_rec_start(dev, path)) &&
                   skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
                push_pseudo_header(skb, phdr->hwaddr);
                __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_pseudo_header *phdr;
        struct ipoib_header *header;
        unsigned long flags;

        phdr = (struct ipoib_pseudo_header *) skb->data;
        skb_pull(skb, sizeof(*phdr));
        header = (struct ipoib_header *) skb->data;

        if (unlikely(phdr->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)) &&
                    (header->proto != htons(ETH_P_TIPC))) {
                        /* 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*/
                phdr->hwaddr[8] = (priv->pkey >> 8) & 0xff;
                phdr->hwaddr[9] = priv->pkey & 0xff;

                neigh = ipoib_neigh_get(dev, phdr->hwaddr);
                if (likely(neigh))
                        goto send_using_neigh;
                ipoib_mcast_send(dev, phdr->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):
        case htons(ETH_P_TIPC):
                neigh = ipoib_neigh_get(dev, phdr->hwaddr);
                if (unlikely(!neigh)) {
                        neigh_add_path(skb, phdr->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, phdr);
                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(phdr->hwaddr));
                goto unref;
        }

        if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
                push_pseudo_header(skb, phdr->hwaddr);
                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(dev)));
        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;

        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 hard header so we can figure out where
         * to send the packet later.
         */
        push_pseudo_header(skb, daddr);

        return IPOIB_HARD_LEN;
}

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(priv->wq, &priv->restart_task);
}

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

        /* parent interface */
        if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags))
                return dev->ifindex;

        /* child/vlan interface */
        return priv->parent->ifindex;
}

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 *d32 = (u32 *) daddr;
        u32 hv;

        hv = jhash_3words(d32[3], d32[4], IPOIB_QPN_MASK & d32[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;
                        }

                        if (likely(skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE))
                                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;
        LIST_HEAD(remove_list);

        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)) {

                                ipoib_check_and_add_mcast_sendonly(priv, neigh->daddr + 4, &remove_list);

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

                }
        }

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

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(priv->wq, &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)));
                        /* remove from parent list */
                        list_del_init(&neigh->list);
                        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 __rcu **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;
        RCU_INIT_POINTER(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(priv->wq, &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_init(&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_init(&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);

        /* 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)
                goto out;

        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;

        /*
         * Must be after ipoib_ib_dev_init so we can allocate a per
         * device wq there and use it here
         */
        if (ipoib_neigh_hash_init(priv) < 0)
                goto out_dev_uninit;

        return 0;

out_dev_uninit:
        ipoib_ib_dev_cleanup(dev);

out_tx_ring_cleanup:
        vfree(priv->tx_ring);

out_rx_ring_cleanup:
        kfree(priv->rx_ring);

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);

        /*
         * Must be before ipoib_ib_dev_cleanup or we delete an in use
         * work queue
         */
        ipoib_neigh_hash_uninit(dev);

        ipoib_ib_dev_cleanup(dev);

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

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

static int ipoib_set_vf_link_state(struct net_device *dev, int vf, int link_state)
{
        struct ipoib_dev_priv *priv = netdev_priv(dev);

        return ib_set_vf_link_state(priv->ca, vf, priv->port, link_state);
}

static int ipoib_get_vf_config(struct net_device *dev, int vf,
                               struct ifla_vf_info *ivf)
{
        struct ipoib_dev_priv *priv = netdev_priv(dev);
        int err;

        err = ib_get_vf_config(priv->ca, vf, priv->port, ivf);
        if (err)
                return err;

        ivf->vf = vf;

        return 0;
}

static int ipoib_set_vf_guid(struct net_device *dev, int vf, u64 guid, int type)
{
        struct ipoib_dev_priv *priv = netdev_priv(dev);

        if (type != IFLA_VF_IB_NODE_GUID && type != IFLA_VF_IB_PORT_GUID)
                return -EINVAL;

        return ib_set_vf_guid(priv->ca, vf, priv->port, guid, type);
}

static int ipoib_get_vf_stats(struct net_device *dev, int vf,
                              struct ifla_vf_stats *vf_stats)
{
        struct ipoib_dev_priv *priv = netdev_priv(dev);

        return ib_get_vf_stats(priv->ca, vf, priv->port, vf_stats);
}

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

static const struct net_device_ops ipoib_netdev_ops_pf = {
        .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,
        .ndo_get_iflink          = ipoib_get_iflink,
        .ndo_set_vf_link_state   = ipoib_set_vf_link_state,
        .ndo_get_vf_config       = ipoib_get_vf_config,
        .ndo_get_vf_stats        = ipoib_get_vf_stats,
        .ndo_set_vf_guid         = ipoib_set_vf_guid,
        .ndo_set_mac_address     = ipoib_set_mac,
};

static const struct net_device_ops ipoib_netdev_ops_vf = {
        .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,
        .ndo_get_iflink          = ipoib_get_iflink,
};

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

        if (priv->hca_caps & IB_DEVICE_VIRTUAL_FUNCTION)
                dev->netdev_ops = &ipoib_netdev_ops_vf;
        else
                dev->netdev_ops = &ipoib_netdev_ops_pf;

        dev->header_ops          = &ipoib_header_ops;

        ipoib_set_ethtool_ops(dev);

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

        dev->watchdog_timeo      = HZ;

        dev->flags              |= IFF_BROADCAST | IFF_MULTICAST;

        dev->hard_header_len     = IPOIB_HARD_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);
        netif_keep_dst(dev);

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

        priv->dev = dev;

        spin_lock_init(&priv->lock);

        init_rwsem(&priv->vlan_rwsem);

        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->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,
                           NET_NAME_UNKNOWN, 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 void set_base_guid(struct ipoib_dev_priv *priv, union ib_gid *gid)
{
        struct ipoib_dev_priv *child_priv;
        struct net_device *netdev = priv->dev;

        netif_addr_lock_bh(netdev);

        memcpy(&priv->local_gid.global.interface_id,
               &gid->global.interface_id,
               sizeof(gid->global.interface_id));
        memcpy(netdev->dev_addr + 4, &priv->local_gid, sizeof(priv->local_gid));
        clear_bit(IPOIB_FLAG_DEV_ADDR_SET, &priv->flags);

        netif_addr_unlock_bh(netdev);

        if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags)) {
                down_read(&priv->vlan_rwsem);
                list_for_each_entry(child_priv, &priv->child_intfs, list)
                        set_base_guid(child_priv, gid);
                up_read(&priv->vlan_rwsem);
        }
}

static int ipoib_check_lladdr(struct net_device *dev,
                              struct sockaddr_storage *ss)
{
        union ib_gid *gid = (union ib_gid *)(ss->__data + 4);
        int ret = 0;

        netif_addr_lock_bh(dev);

        /* Make sure the QPN, reserved and subnet prefix match the current
         * lladdr, it also makes sure the lladdr is unicast.
         */
        if (memcmp(dev->dev_addr, ss->__data,
                   4 + sizeof(gid->global.subnet_prefix)) ||
            gid->global.interface_id == 0)
                ret = -EINVAL;

        netif_addr_unlock_bh(dev);

        return ret;
}

static int ipoib_set_mac(struct net_device *dev, void *addr)
{
        struct ipoib_dev_priv *priv = netdev_priv(dev);
        struct sockaddr_storage *ss = addr;
        int ret;

        if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
                return -EBUSY;

        ret = ipoib_check_lladdr(dev, ss);
        if (ret)
                return ret;

        set_base_guid(priv, (union ib_gid *)(ss->__data + 4));

        queue_work(ipoib_workqueue, &priv->flush_light);

        return 0;
}

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 || pkey == 0x8000)
                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);
}

void ipoib_set_dev_features(struct ipoib_dev_priv *priv, struct ib_device *hca)
{
        priv->hca_caps = hca->attrs.device_cap_flags;

        if (priv->hca_caps & IB_DEVICE_UD_IP_CSUM) {
                priv->dev->hw_features = 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;
        }
}

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->dev.parent);
        priv->dev->dev_id = port - 1;

        result = ib_query_port(hca, port, &attr);
        if (!result)
                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->max_mtu = IPOIB_CM_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;
        }

        ipoib_set_dev_features(priv, hca);

        /*
         * 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, NULL);
        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));
        set_bit(IPOIB_FLAG_DEV_ADDR_SET, &priv->flags);

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

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 p;
        int count = 0;

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

        INIT_LIST_HEAD(dev_list);

        for (p = rdma_start_port(device); p <= rdma_end_port(device); ++p) {
                if (!rdma_protocol_ib(device, p))
                        continue;
                dev = ipoib_add_port("ib%d", device, p);
                if (!IS_ERR(dev)) {
                        priv = netdev_priv(dev);
                        list_add_tail(&priv->list, dev_list);
                        count++;
                }
        }

        if (!count) {
                kfree(dev_list);
                return;
        }

        ib_set_client_data(device, &ipoib_client, dev_list);
}

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

        if (!dev_list)
                return;

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

                /* mark interface in the middle of destruction */
                set_bit(IPOIB_FLAG_GOING_DOWN, &priv->flags);

                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(priv->wq);

                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 a global workqueue here that is used for all flush
         * operations.  However, if you attempt to flush a workqueue
         * from a task on that same workqueue, it deadlocks the system.
         * We want to be able to flush the tasks associated with a
         * specific net device, so we also create a workqueue for each
         * netdevice.  We queue up the tasks for that device only on
         * its private workqueue, and we only queue up flush events
         * on our global flush workqueue.  This avoids the deadlocks.
         */
        ipoib_workqueue = alloc_ordered_workqueue("ipoib_flush",
                                                  WQ_MEM_RECLAIM);
        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);