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

#include "ipoib.h"

#include <linux/module.h>

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

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

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

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

MODULE_AUTHOR("Roland Dreier");
MODULE_DESCRIPTION("IP-over-InfiniBand net driver");
MODULE_LICENSE("Dual BSD/GPL");
#ifdef RETPOLINE_MLNX
MODULE_INFO(retpoline, "Y");
#endif

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");

static int lro = 1;
module_param(lro, bool, 0444);
MODULE_PARM_DESC(lro,  "Enable LRO (Large Receive Offload)");

static int lro_max_aggr = IPOIB_LRO_MAX_AGGR;
module_param(lro_max_aggr, int, 0644);
MODULE_PARM_DESC(lro_max_aggr, "LRO: Max packets to be aggregated "
		"(default = 64)");

#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

int ipoib_mc_sendonly_timeout;

module_param_named(mc_sendonly_timeout, ipoib_mc_sendonly_timeout, int, 0644);
MODULE_PARM_DESC(mc_sendonly_timeout, "Enable debug tracing if > 0");

#ifndef rcu_dereference_protected
#define rcu_dereference_protected(p, c) \
		rcu_dereference((p))
#endif

#ifndef rcu_dereference_bh
#define rcu_dereference_bh(p) \
		rcu_dereference((p))
#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 workqueue_struct *ipoib_auto_moder_workqueue;

struct ib_sa_client ipoib_sa_client;

static LIST_HEAD(ipoib_all_neigh_list);

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

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

#define to_net_dev(class) container_of(class, struct net_device, class_dev)

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);

	if (priv->ethtool.use_adaptive_rx_coalesce) {
		set_bit(IPOIB_FLAG_AUTO_MODER, &priv->flags);
		queue_delayed_work(ipoib_auto_moder_workqueue,
					   &priv->adaptive_moder_task,
					   ADAPT_MODERATION_DELAY);
	}

	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");
	mutex_lock(&priv->state_lock);
	clear_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags);
	mutex_unlock(&priv->state_lock);

	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 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);

	queue_work(ipoib_workqueue, &priv->flush_light);

	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 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 " IPOIB_GID_FMT " invalid\n",
			be16_to_cpu(path->pathrec.dlid),
			IPOIB_GID_ARG(path->pathrec.dgid));
		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);
		list_del(&path->list);
		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;
	int ret;

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

	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 (ah) {
		path->pathrec = *pathrec;

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

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

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

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

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

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

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

	spin_unlock_irqrestore(&priv->lock, flags);

	if (old_ah)
		ipoib_put_ah(old_ah);

	while ((skb = __skb_dequeue(&skqueue))) {
		skb->dev = dev;
		ret = dev_queue_xmit(skb);
		if (ret)
			ipoib_warn(priv, "%s: dev_queue_xmit failed to requeue"
					 " 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);
	ib_sa_comp_mask comp_mask = IB_SA_PATH_REC_MTU_SELECTOR | IB_SA_PATH_REC_MTU;
	struct ib_sa_path_rec p_rec;

	p_rec = path->pathrec;
	p_rec.mtu_selector = IB_SA_GT;

	switch (roundup_pow_of_two(dev->mtu + IPOIB_ENCAP_LEN)) {
	case 512:
		p_rec.mtu = IB_MTU_256;
		break;
	case 1024:
		p_rec.mtu = IB_MTU_512;
		break;
	case 2048:
		p_rec.mtu = IB_MTU_1024;
		break;
	case 4096:
		p_rec.mtu = IB_MTU_2048;
		break;
	default:
		/* Wildcard everything */
		comp_mask = 0;
		p_rec.mtu = 0;
		p_rec.mtu_selector = 0;
	}

	ipoib_dbg(priv, "Start path record lookup for " IPOIB_GID_FMT " > %d\n",
		  IPOIB_GID_ARG(p_rec.dgid),
		  comp_mask ? ib_mtu_enum_to_int(p_rec.mtu) : 0);

	init_completion(&path->done);

	path->query_id =
		ib_sa_path_rec_get(&ipoib_sa_client, priv->ca, priv->port,
				   &p_rec, comp_mask		|
				   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, 0, 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);
		++priv->stats.tx_dropped;
		dev_kfree_skb_any(skb);
		return;
	}

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

		__path_add(dev, path);
	}

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

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

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

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

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

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

err_list:
	list_del_init(&neigh->list);

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

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

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

	spin_lock_irqsave(&priv->lock, flags);

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

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

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

		ipoib_send(dev, skb, path->ah, IPOIB_QPN(cb->hwaddr));
	} 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 {
		++priv->stats.tx_dropped;
		dev_kfree_skb_any(skb);
	}

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

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

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

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

                neigh = ipoib_neigh_get(dev, cb->hwaddr);
                if (likely(neigh))
                        goto send_using_neigh;
                ipoib_mcast_send(dev, cb->hwaddr, skb);
                return NETDEV_TX_OK;
        }
        /* unicast, arrange "switch" according to probability */
        switch (htons(header->proto)) {
        case ETH_P_IP:
        case ETH_P_IPV6:
                neigh = ipoib_neigh_get(dev, cb->hwaddr);
                if (unlikely(!neigh)) {
                        neigh_add_path(skb, cb->hwaddr, dev);
                        return NETDEV_TX_OK;
                }
                break;
        case ETH_P_ARP:
        case ETH_P_RARP:
                /* for unicast ARP and RARP should always perform path find */
                unicast_arp_send(skb, dev, cb);
                return NETDEV_TX_OK;
        default:
                /* ethertype not supported by IPoIB */
                ++priv->stats.tx_dropped;
                dev_kfree_skb_any(skb);
                return NETDEV_TX_OK;
        }
send_using_neigh:
        /* note we now hold a ref to neigh */
        if (ipoib_cm_get(neigh)) {
                if (ipoib_cm_up(neigh)) {
                        ipoib_cm_send(dev, skb, ipoib_cm_get(neigh));
                        goto unref;
                }
        } else if (neigh->ah) {
                ipoib_send(dev, skb, neigh->ah, IPOIB_QPN(cb->hwaddr));
                goto unref;
        }

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

unref:
        ipoib_neigh_put(neigh);

        return NETDEV_TX_OK;
}

static struct net_device_stats *ipoib_get_stats(struct net_device *dev)
{
	struct ipoib_dev_priv *priv = netdev_priv(dev);

	return &priv->stats;
}

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, tx_outstanding %u ipoib_sendq_size: %d \n",
		   netif_queue_stopped(dev),priv->tx_head, priv->tx_tail, priv->tx_outstanding, ipoib_sendq_size);

	if (unlikely(priv->tx_outstanding < ipoib_sendq_size >> 1) &&
	    netif_queue_stopped(dev) &&
	    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags)) {
		ipoib_warn(priv, "%s: waking the queue\n", __func__);
		netif_wake_queue(dev);
	}

	/* XXX reset QP, etc. */
}

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

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

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

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

	return 0;
}

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

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

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

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

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

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

	rcu_read_lock_bh();

	htbl = rcu_dereference_bh(ntbl->htbl);

	if (!htbl)
		goto out_unlock;

	hash_val = ipoib_addr_hash(htbl, daddr);
	for (neigh = rcu_dereference_bh(htbl->buckets[hash_val]);
	     neigh != NULL;
	     neigh = rcu_dereference_bh(neigh->hnext)) {
		/* don't use flags for the comapre */
		if (memcmp(daddr+1, neigh->daddr+1, INFINIBAND_ALEN-1) == 0) {
			/* found, take one ref on behalf of the caller */
			if (!atomic_inc_not_zero(&neigh->refcnt)) {
				/* deleted */
				neigh = NULL;
				goto out_unlock;
			}
			neigh->alive = jiffies;
			goto out_unlock;
		}
	}

out_unlock:
	rcu_read_unlock_bh();
	return neigh;
}

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

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

	spin_lock_irqsave(&priv->lock, flags);

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

	if (!htbl)
		goto out_unlock;

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

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

		while ((neigh = rcu_dereference_protected(*np,
				lockdep_is_held(&priv->lock))) != NULL) {
			/* was the neigh idle for two GC periods */
			if (time_after(neigh_obsolete, neigh->alive)) {
				rcu_assign_pointer(*np,
					rcu_dereference_protected(neigh->hnext,
						lockdep_is_held(&priv->lock)));
				/* remove from path/mc list */
				list_del_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_reap_neigh(struct work_struct *work)
{
	struct ipoib_dev_priv *priv =
		container_of(work, struct ipoib_dev_priv, neigh_reap_task.work);

	__ipoib_reap_neigh(priv);

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

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

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

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

	ipoib_dbg(netdev_priv(dev),
		  "neigh ctor for %06x %pI6\n",
		  IPOIB_QPN(neigh->daddr),
		  neigh->daddr + 4);

	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))) {
		/* don't use flags for the comapre */
		if (memcmp(daddr+1, neigh->daddr+1, INFINIBAND_ALEN-1) == 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))) {
		++priv->stats.tx_dropped;
		dev_kfree_skb_any(skb);
	}
	if (ipoib_cm_get(neigh))
		ipoib_cm_destroy_tx(ipoib_cm_get(neigh));
	ipoib_dbg(netdev_priv(dev),
		  "neigh free for %06x %pI6\n",
		  IPOIB_QPN(neigh->daddr),
		  neigh->daddr + 4);
	kfree(neigh);
	if (atomic_dec_and_test(&priv->ntbl.entries)) {
		if (test_bit(IPOIB_NEIGH_TBL_FLUSH, &priv->flags))
			complete(&priv->ntbl.flushed);
	}
}

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

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


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

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

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

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

        return 0;
}

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

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

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

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

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

        if (!htbl)
                goto out_unlock;

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

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

	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(&ntbl->rwlock))) != NULL) {
                        rcu_assign_pointer(*np,
                                           rcu_dereference_protected(neigh->hnext,
                                                                     lockdep_is_held(&ntbl->rwlock)));
                        /* remove from path/mc list */
                        spin_lock_irqsave(&priv->lock, flags);
                        list_del_init(&neigh->list);
                        spin_unlock_irqrestore(&priv->lock, flags);
                        call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
                }
        }

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

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

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_sync(&priv->neigh_reap_task);

	ipoib_flush_neighs(priv);

	wait_for_completion(&priv->ntbl.deleted);

}

static void ipoib_set_default_moderation(struct ipoib_dev_priv *priv)
{

	/* If we haven't received a specific coalescing setting
	 * (module param), we set the moderation parameters as follows:
	 * - moder_cnt is set to the number of mtu sized packets to
	 *   satisfy our coaelscing target.
	 * - moder_time is set to a fixed value.
	 */
	priv->ethtool.rx_max_coalesced_frames = IPOIB_RX_COAL_TARGET;
	priv->ethtool.rx_coalesce_usecs = IPOIB_RX_COAL_TIME;
	printk(KERN_ERR "Default coalesing params for mtu:%d - "
			   "rx_frames:%d rx_usecs:%d\n",
	       priv->dev->mtu, priv->ethtool.rx_max_coalesced_frames,
	       priv->ethtool.rx_coalesce_usecs);

	/* Reset auto-moderation params */
	priv->ethtool.pkt_rate_low = IPOIB_RX_RATE_LOW;
	priv->ethtool.rx_coalesce_usecs_low = IPOIB_RX_COAL_TIME_LOW;
	priv->ethtool.pkt_rate_high = IPOIB_RX_RATE_HIGH;
	priv->ethtool.rx_coalesce_usecs_high = IPOIB_RX_COAL_TIME_HIGH;
	priv->ethtool.sample_interval = IPOIB_SAMPLE_INTERVAL;
	priv->ethtool.use_adaptive_rx_coalesce = 1;
	priv->ethtool.last_moder_time = IPOIB_AUTO_CONF;
	priv->ethtool.last_moder_jiffies = 0;
	priv->ethtool.last_moder_packets = 0;
	priv->ethtool.last_moder_tx_packets = 0;
	priv->ethtool.last_moder_bytes = 0;
}
/*
The function classifies the incoming traffic during each sampling interval
into classes. The rx_usec value (i.e., moderation time) is then adjusted
appropriately per class.
There are two classes defined:
	A. Bulk traffic: for heavy traffic consisting of packets of normal size.
	This class is further divided into two sub-classes:
		1. Traffic that is mainly BW bound
		- This traffic will get maximum moderation.
		2. Traffic that is mostly latency bound
		- For situations where low latency is vital
		- The rx_usec will be changed to a value in the range:
		(ethtool.pkt_rate_low  .. ethtool.pkt_rate_high)
		depending on sampled packet rate.
	B.  Low latency traffic: for minimal traffic, or small packets.
	- This traffic will get minimum moderation.
*/
static void ipoib_auto_moderation(struct ipoib_dev_priv *priv)
{
	unsigned long period = jiffies - priv->ethtool.last_moder_jiffies;
	unsigned long packets;
	unsigned long rate;
	unsigned long avg_pkt_size;
	unsigned long rx_packets;
	unsigned long rx_bytes;
	unsigned long tx_packets;
	unsigned long tx_pkt_diff;
	unsigned long rx_pkt_diff;
	int moder_time;
	int ret;

	if (!priv->ethtool.use_adaptive_rx_coalesce)
		return;

	rx_packets = priv->stats.rx_packets;
	rx_bytes = priv->stats.rx_bytes;
	tx_packets = priv->stats.tx_packets;

	tx_pkt_diff = tx_packets - priv->ethtool.last_moder_tx_packets;
	rx_pkt_diff = rx_packets - priv->ethtool.last_moder_packets;
	packets = max(tx_pkt_diff, rx_pkt_diff);
	rate = packets * HZ / period;
	avg_pkt_size = packets ?
		(rx_bytes - priv->ethtool.last_moder_bytes) / packets : 0;

	/* Apply auto-moderation only when packet rate exceeds a rate that
	 * it matters */
	if (rate > IPOIB_RX_RATE_THRESH &&
                    avg_pkt_size > IPOIB_AVG_PKT_SMALL) {
		if (rate < priv->ethtool.pkt_rate_low)
			moder_time =
				priv->ethtool.rx_coalesce_usecs_low;
		else if (rate > priv->ethtool.pkt_rate_high)
			moder_time =
				priv->ethtool.rx_coalesce_usecs_high;
		else
			moder_time = (rate - priv->ethtool.pkt_rate_low) *
				(priv->ethtool.rx_coalesce_usecs_high - priv->ethtool.rx_coalesce_usecs_low) /
				(priv->ethtool.pkt_rate_high - priv->ethtool.pkt_rate_low) +
				priv->ethtool.rx_coalesce_usecs_low;

	} else
		moder_time = priv->ethtool.rx_coalesce_usecs_low;

	if (moder_time != priv->ethtool.last_moder_time) {
		struct ib_cq_attr  attr;

		memset(&attr, 0, sizeof(attr));
		attr.moderation.cq_count = priv->ethtool.rx_max_coalesced_frames;
		attr.moderation.cq_period = moder_time;
		ipoib_dbg(priv, "%s: Rx moder_time changed from:%d to %d\n",
		       __func__, priv->ethtool.last_moder_time, moder_time);
		priv->ethtool.last_moder_time = moder_time;
		ret = ib_modify_cq(priv->recv_cq,
				   &attr,
				   IB_CQ_MODERATE);
		if (ret && ret != -ENOSYS)
			ipoib_warn(priv, "%s: failed modifying CQ (%d)\n",
				   __func__, ret);
	}

	priv->ethtool.last_moder_packets = rx_packets;
	priv->ethtool.last_moder_tx_packets = tx_packets;
	priv->ethtool.last_moder_bytes = rx_bytes;
	priv->ethtool.last_moder_jiffies = jiffies;
}

static void ipoib_config_adapt_moder(struct work_struct *work)
{
	struct delayed_work *delay = to_delayed_work(work);
	struct ipoib_dev_priv *priv = container_of(delay,
						   struct ipoib_dev_priv,
						   adaptive_moder_task);

	if (!(netif_running(priv->dev) && netif_carrier_ok(priv->dev))) {
		ipoib_dbg(priv, "%s: port is not ACTIVE, no configuration"
				" for adaptive moderation\n",
			  __func__);
		return;
	}

	ipoib_auto_moderation(priv);

	if (test_bit(IPOIB_FLAG_AUTO_MODER, &priv->flags) &&
	    priv->ethtool.use_adaptive_rx_coalesce)
		queue_delayed_work(ipoib_auto_moder_workqueue,
				   &priv->adaptive_moder_task,
				   ADAPT_MODERATION_DELAY);
}

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

	if (ipoib_neigh_hash_init(priv) < 0)
		goto out;

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

	priv->tx_ring = vmalloc(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;
	}
	memset(priv->tx_ring, 0, ipoib_sendq_size * sizeof *priv->tx_ring);

	/* priv->tx_head, tx_tail & tx_outstanding are already 0 */
	if (ipoib_ib_dev_init(dev, ca, port))
		goto out_tx_ring_cleanup;

	ipoib_set_default_moderation(priv);

	return 0;

out_tx_ring_cleanup:
	vfree(priv->tx_ring);

out_rx_ring_cleanup:
	kfree(priv->rx_ring);

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

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

	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_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;

	ipoib_neigh_hash_uninit(dev);
}

static int get_skb_hdr(struct sk_buff *skb, void **iphdr,
		       void **tcph, u64 *hdr_flags, void *priv)
{
	unsigned int ip_len;
	struct iphdr *iph;

	if (unlikely(skb->protocol != htons(ETH_P_IP)))
		return -1;

	/*
	 * In the future we may add an else clause that verifies the
	 * checksum and allows devices which do not calculate checksum
	 * to use LRO.
	 */
	if (unlikely(skb->ip_summed != CHECKSUM_UNNECESSARY))
		return -1;

	/* Check for non-TCP packet */
	skb_reset_network_header(skb);
	iph = ip_hdr(skb);
	if (iph->protocol != IPPROTO_TCP)
		return -1;

	ip_len = ip_hdrlen(skb);
	skb_set_transport_header(skb, ip_len);
	*tcph = tcp_hdr(skb);

	/* check if IP header and TCP header are complete */
	if (ntohs(iph->tot_len) < ip_len + tcp_hdrlen(skb))
		return -1;

	*hdr_flags = LRO_IPV4 | LRO_TCP;
	*iphdr = iph;

	return 0;
}

static void ipoib_lro_setup(struct ipoib_dev_priv *priv)
{
	priv->lro.lro_mgr.max_aggr	 = lro_max_aggr;
	priv->lro.lro_mgr.max_desc	 = IPOIB_MAX_LRO_DESCRIPTORS;
	priv->lro.lro_mgr.lro_arr	 = priv->lro.lro_desc;
	priv->lro.lro_mgr.get_skb_header = get_skb_hdr;
	priv->lro.lro_mgr.features	 = LRO_F_NAPI;
	priv->lro.lro_mgr.dev		 = priv->dev;
	priv->lro.lro_mgr.ip_summed_aggr = CHECKSUM_UNNECESSARY;
}

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

	dev->open                = ipoib_open;
	dev->stop                = ipoib_stop;
	dev->change_mtu          = ipoib_change_mtu;
	dev->hard_start_xmit     = ipoib_start_xmit;
	dev->get_stats 		 = ipoib_get_stats;
	dev->tx_timeout          = ipoib_timeout;
	dev->set_multicast_list  = ipoib_set_mcast_list;

	dev->hard_header         = ipoib_hard_header;

	ipoib_set_ethtool_ops(dev);

	dev->poll                = ipoib_poll;
	dev->weight              = 100;

	dev->watchdog_timeo	 = 5 * 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);

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

	netif_carrier_off(dev);

	priv->dev = dev;

	ipoib_lro_setup(priv);

	spin_lock_init(&priv->lock);
	spin_lock_init(&priv->rx_ring_lock);

	mutex_init(&priv->vlan_mutex);
	mutex_init(&priv->state_lock);

	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_join_task,   ipoib_mcast_join_task);
	INIT_DELAYED_WORK(&priv->mcast_leave_task, ipoib_mcast_leave_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->adaptive_moder_task, ipoib_config_adapt_moder);
	INIT_DELAYED_WORK(&priv->neigh_reap_task, ipoib_reap_neigh);
}

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

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

	return netdev_priv(dev);
}

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

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

static ssize_t show_dev_id(struct class_device *d, char *buf)
{
	return sprintf(buf, "%d\n", to_net_dev(d)->dev_id);
}
static CLASS_DEVICE_ATTR(dev_id, S_IRUGO, show_dev_id, NULL);

static ssize_t show_umcast(struct class_device *dev, 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 class_device *dev,
			  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 CLASS_DEVICE_ATTR(umcast, S_IWUSR | S_IRUGO, show_umcast, set_umcast);

int ipoib_add_umcast_attr(struct net_device *dev)
{
	return class_device_create_file(&dev->class_dev,
					&class_device_attr_umcast);
}

static int parse_child(struct device *dev, const char *buf, int *pkey,
		       int *child_index)
{
	int ret;
	struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(dev));

	*pkey = *child_index = -1;

	/* 'pkey' or 'pkey.child_index' or '.child_index' are allowed */
	ret = sscanf(buf, "%i.%i", pkey, child_index);
	if (ret == 1)  /* just pkey, implicit child index is 0 */
		*child_index = 0;
	else  if (ret != 2) { /* pkey same as parent, specified child index */
		*pkey = priv->pkey;
		ret  = sscanf(buf, ".%i", child_index);
		if (ret != 1 || *child_index == 0)
			return -EINVAL;
	}

	if (*child_index < 0 || *child_index > 0xff)
		return -EINVAL;

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

	ipoib_dbg(priv, "parse_child inp %s out pkey %04x index %d\n",
		buf, *pkey, *child_index);
	return 0;
}

static ssize_t create_child(struct class_device *dev,
			    const char *buf, size_t count)
{
	int pkey, child_index;
	int ret;

	if (parse_child(dev, buf, &pkey, &child_index))
		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, child_index);

	return ret ? ret : count;
}
static CLASS_DEVICE_ATTR(create_child, S_IWUGO, NULL, create_child);

static ssize_t delete_child(struct class_device *dev,
			    const char *buf, size_t count)
{
	int pkey, child_index;
	int ret;

	if (parse_child(dev, buf, &pkey, &child_index))
		return -EINVAL;

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

	return ret ? ret : count;

}
static CLASS_DEVICE_ATTR(delete_child, S_IWUGO, NULL, delete_child);

int ipoib_add_pkey_attr(struct net_device *dev)
{
	return class_device_create_file(&dev->class_dev,
					&class_device_attr_pkey);
}

void set_lro_features_bit(struct ipoib_dev_priv *priv)
{
	if (lro)
		priv->dev->features |= NETIF_F_LRO;
	/*no support in LRO with 4k mtu.*/
	if (ipoib_ud_need_sg(priv->max_ib_mtu))
		priv->dev->features  &= ~NETIF_F_LRO;
}

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) {
		set_bit(IPOIB_FLAG_CSUM, &priv->flags);
		priv->dev->features |= NETIF_F_SG | NETIF_F_IP_CSUM;
	}

	set_lro_features_bit(priv);

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

	priv->dev->features |= SOCK_ACCL_POLL_TCP | SOCK_ACCL_POLL_UDP;

	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;

	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;
	}

	result = ipoib_set_dev_features(priv, hca);
	if (result) {
		printk(KERN_WARNING "%s: failed to set device features for port %d (ret = %d)\n",
		       hca->name, port, result);
		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;

	priv->accl_priv.poll = &ipoib_accl_poll;
	priv->accl_priv.get_tcp_ring = ipoib_get_tcp_ring;
	priv->accl_priv.get_udp_rings = ipoib_get_udp_rings;

	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));

	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;
	}
	/*force lro on the dev->features, because the function
	register_netdev disable it according to our private lro*/
	set_lro_features_bit(priv);

	ipoib_create_debug_files(priv->dev);

	result = -ENOMEM;

	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 (class_device_create_file(&priv->dev->class_dev,
				     &class_device_attr_create_child))
		goto sysfs_failed;
	if (class_device_create_file(&priv->dev->class_dev,
				     &class_device_attr_delete_child))
		goto sysfs_failed;
	if (class_device_create_file(&priv->dev->class_dev,
				     &class_device_attr_dev_id))
		goto sysfs_failed;

	return priv->dev;

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

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

event_failed:
	ipoib_dev_cleanup(priv->dev);

device_init_failed:
	free_netdev(priv->dev);

alloc_mem_failed:
	return ERR_PTR(result);
}

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

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

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

	INIT_LIST_HEAD(dev_list);

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

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

	ib_set_client_data(device, &ipoib_client, dev_list);
}

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

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

	dev_list = ib_get_client_data(device, &ipoib_client);
	if (!dev_list)
		return;

	list_for_each_entry_safe(priv, tmp, dev_list, list) {
		if (rdma_port_get_link_layer(device, priv->port) != IB_LINK_LAYER_INFINIBAND)
			continue;

		set_bit(IPOIB_FLAG_MODULE_DOWN, &priv->flags);
		ib_unregister_event_handler(&priv->event_handler);

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

		/* Stop GC */
		set_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);
		cancel_delayed_work(&priv->neigh_reap_task);
		flush_workqueue(ipoib_workqueue);
		flush_workqueue(ipoib_auto_moder_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 = max(ipoib_sendq_size, max(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;
	}

	ipoib_auto_moder_workqueue =
		create_singlethread_workqueue("ipoib_auto_moder");
	if (!ipoib_auto_moder_workqueue) {
		ret = -ENOMEM;
		goto err_am;
	}


	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_auto_moder_workqueue);
err_am:
	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);
	destroy_workqueue(ipoib_auto_moder_workqueue);
}

module_init(ipoib_init_module);
module_exit(ipoib_cleanup_module);
