/*
 * 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 <net/dst.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 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, 0);
        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 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;
}

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 ipoib_dev_priv *priv = netdev_priv(dev);
        struct ipoib_neigh *neigh, *tn;
        struct sk_buff *skb;
        unsigned long flags;

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

        spin_lock_irqsave(&priv->lock, flags);

        list_for_each_entry_safe(neigh, tn, &path->neigh_list, list) {
                /*
                 * It's safe to call ipoib_put_ah() inside priv->lock
                 * here, because we know that path->ah will always
                 * hold one more reference, so ipoib_put_ah() will
                 * never do more than decrement the ref count.
                 */
                if (neigh->ah)
                        ipoib_put_ah(neigh->ah);

                ipoib_neigh_free(dev, neigh);
        }

        spin_unlock_irqrestore(&priv->lock, flags);

        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;
                        memcpy(&neigh->dgid.raw, &path->pathrec.dgid.raw,
                               sizeof(union ib_gid));

                        if (ipoib_cm_enabled(dev, neigh->neighbour)) {
                                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);
                                        if (neigh->ah)
                                                ipoib_put_ah(neigh->ah);
                                        ipoib_neigh_free(dev, 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;
}

/* called with rcu_read_lock */
static void neigh_add_path(struct sk_buff *skb, struct neighbour *n, struct net_device *dev)
{
        struct ipoib_dev_priv *priv = netdev_priv(dev);
        struct ipoib_path *path;
        struct ipoib_neigh *neigh;
        unsigned long flags;

        neigh = ipoib_neigh_alloc(n, skb->dev);
        if (!neigh) {
                ++dev->stats.tx_dropped;
                dev_kfree_skb_any(skb);
                return;
        }

        spin_lock_irqsave(&priv->lock, flags);

        path = __path_find(dev, n->ha + 4);
        if (!path) {
                path = path_rec_create(dev, n->ha + 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;
                memcpy(&neigh->dgid.raw, &path->pathrec.dgid.raw,
                       sizeof(union ib_gid));

                if (ipoib_cm_enabled(dev, neigh->neighbour)) {
                        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);
                                if (neigh->ah)
                                        ipoib_put_ah(neigh->ah);
                                ipoib_neigh_free(dev, 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(n->ha));
                        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);
        return;

err_list:
        list_del(&neigh->list);

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

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

/* called with rcu_read_lock */
static void ipoib_path_lookup(struct sk_buff *skb, struct neighbour *n, struct net_device *dev)
{
        struct ipoib_dev_priv *priv = netdev_priv(skb->dev);

        /* Look up path record for unicasts */
        if (n->ha[4] != 0xff) {
                neigh_add_path(skb, n, dev);
                return;
        }

        /* Add in the P_Key for multicasts */
        n->ha[8] = (priv->pkey >> 8) & 0xff;
        n->ha[9] = priv->pkey & 0xff;
        ipoib_mcast_send(dev, n->ha + 4, skb);
}

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 neighbour *n = NULL;
        unsigned long flags;

        rcu_read_lock();
        if (likely(skb_dst(skb))) {
                n = dst_get_neighbour_noref(skb_dst(skb));
                if (!n) {
                        ++dev->stats.tx_dropped;
                        dev_kfree_skb_any(skb);
                        goto unlock;
                }
        }
        if (likely(n)) {
                if (unlikely(!*to_ipoib_neigh(n))) {
                        ipoib_path_lookup(skb, n, dev);
                        goto unlock;
                }

                neigh = *to_ipoib_neigh(n);

                if (unlikely((memcmp(&neigh->dgid.raw,
                                     n->ha + 4,
                                     sizeof(union ib_gid))) ||
                             (neigh->dev != dev))) {
                        spin_lock_irqsave(&priv->lock, flags);
                        /*
                         * It's safe to call ipoib_put_ah() inside
                         * priv->lock here, because we know that
                         * path->ah will always hold one more reference,
                         * so ipoib_put_ah() will never do more than
                         * decrement the ref count.
                         */
                        if (neigh->ah)
                                ipoib_put_ah(neigh->ah);
                        list_del(&neigh->list);
                        ipoib_neigh_free(dev, neigh);
                        spin_unlock_irqrestore(&priv->lock, flags);
                        ipoib_path_lookup(skb, n, dev);
                        goto unlock;
                }

                if (ipoib_cm_get(neigh)) {
                        if (ipoib_cm_up(neigh)) {
                                ipoib_cm_send(dev, skb, ipoib_cm_get(neigh));
                                goto unlock;
                        }
                } else if (neigh->ah) {
                        ipoib_send(dev, skb, neigh->ah, IPOIB_QPN(n->ha));
                        goto unlock;
                }

                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);
                }
        } else {
                struct ipoib_cb *cb = (struct ipoib_cb *) skb->cb;

                if (cb->hwaddr[4] == 0xff) {
                        /* Add in the P_Key for multicast*/
                        cb->hwaddr[8] = (priv->pkey >> 8) & 0xff;
                        cb->hwaddr[9] = priv->pkey & 0xff;

                        ipoib_mcast_send(dev, cb->hwaddr + 4, skb);
                } else {
                        /* unicast GID -- should be ARP or RARP reply */

                        if ((be16_to_cpup((__be16 *) skb->data) != ETH_P_ARP) &&
                            (be16_to_cpup((__be16 *) skb->data) != ETH_P_RARP)) {
                                ipoib_warn(priv, "Unicast, no %s: type %04x, QPN %06x %pI6\n",
                                           skb_dst(skb) ? "neigh" : "dst",
                                           be16_to_cpup((__be16 *) skb->data),
                                           IPOIB_QPN(cb->hwaddr),
                                           cb->hwaddr + 4);
                                dev_kfree_skb_any(skb);
                                ++dev->stats.tx_dropped;
                                goto unlock;
                        }

                        unicast_arp_send(skb, dev, cb);
                }
        }
unlock:
        rcu_read_unlock();
        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;

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

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

        /*
         * If we don't have a dst_entry structure, stuff the
         * destination address into skb->cb so we can figure out where
         * to send the packet later.
         */
        if (!skb_dst(skb)) {
                struct ipoib_cb *cb = (struct ipoib_cb *) skb->cb;
                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 void ipoib_neigh_cleanup(struct neighbour *n)
{
        struct ipoib_neigh *neigh;
        struct ipoib_dev_priv *priv = netdev_priv(n->dev);
        unsigned long flags;
        struct ipoib_ah *ah = NULL;

        neigh = *to_ipoib_neigh(n);
        if (neigh)
                priv = netdev_priv(neigh->dev);
        else
                return;
        ipoib_dbg(priv,
                  "neigh_cleanup for %06x %pI6\n",
                  IPOIB_QPN(n->ha),
                  n->ha + 4);

        spin_lock_irqsave(&priv->lock, flags);

        if (neigh->ah)
                ah = neigh->ah;
        list_del(&neigh->list);
        ipoib_neigh_free(n->dev, neigh);

        spin_unlock_irqrestore(&priv->lock, flags);

        if (ah)
                ipoib_put_ah(ah);
}

struct ipoib_neigh *ipoib_neigh_alloc(struct neighbour *neighbour,
                                      struct net_device *dev)
{
        struct ipoib_neigh *neigh;

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

        neigh->neighbour = neighbour;
        neigh->dev = dev;
        memset(&neigh->dgid.raw, 0, sizeof (union ib_gid));
        *to_ipoib_neigh(neighbour) = neigh;
        skb_queue_head_init(&neigh->queue);
        ipoib_cm_set(neigh, NULL);

        return neigh;
}

void ipoib_neigh_free(struct net_device *dev, struct ipoib_neigh *neigh)
{
        struct sk_buff *skb;
        *to_ipoib_neigh(neigh->neighbour) = NULL;
        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));
        kfree(neigh);
}

static int ipoib_neigh_setup_dev(struct net_device *dev, struct neigh_parms *parms)
{
        parms->neigh_cleanup = ipoib_neigh_cleanup;

        return 0;
}

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) {
                printk(KERN_WARNING "%s: failed to allocate RX ring (%d entries)\n",
                       ca->name, ipoib_recvq_size);
                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;

        return 0;

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;

        ipoib_delete_debug_files(dev);

        /* Delete any child interfaces first */
        list_for_each_entry_safe(cpriv, tcpriv, &priv->child_intfs, list) {
                unregister_netdev(cpriv->dev);
                ipoib_dev_cleanup(cpriv->dev);
                free_netdev(cpriv->dev);
        }

        ipoib_ib_dev_cleanup(dev);

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

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

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

static const struct net_device_ops ipoib_netdev_ops = {
        .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_neigh_setup         = ipoib_neigh_setup_dev,
};

static 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);
}

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));
}

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

        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);

        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);
        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();

                flush_workqueue(ipoib_workqueue);

                unregister_netdev(priv->dev);
                ipoib_dev_cleanup(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;

        return 0;

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)
{
        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);