net/tipc/ib_media.c - maze/linux - Git at Google

 /*
  * net/tipc/ib_media.c: Infiniband bearer support for TIPC
  *
  * Copyright (c) 2013 Patrick McHardy <kaber@trash.net>
  *
  * Based on eth_media.c, which carries the following copyright notice:
  *
  * Copyright (c) 2001-2007, Ericsson AB
  * Copyright (c) 2005-2008, 2011, Wind River Systems
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. 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.
  * 3. Neither the names of the copyright holders nor the names of its
  *    contributors may be used to endorse or promote products derived from
  *    this software without specific prior written permission.
  *
  * Alternatively, this software may be distributed under the terms of the
  * GNU General Public License ("GPL") version 2 as published by the Free
  * Software Foundation.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */

 #include <linux/if_infiniband.h>
 #include "core.h"
 #include "bearer.h"

 #define MAX_IB_BEARERS		MAX_BEARERS

 /**
  * struct ib_bearer - Infiniband bearer data structure
  * @bearer: ptr to associated "generic" bearer structure
  * @dev: ptr to associated Infiniband network device
  * @tipc_packet_type: used in binding TIPC to Infiniband driver
  * @cleanup: work item used when disabling bearer
  */

 struct ib_bearer {
 	struct tipc_bearer *bearer;
 	struct net_device *dev;
 	struct packet_type tipc_packet_type;
 	struct work_struct setup;
 	struct work_struct cleanup;
 };

 static struct tipc_media ib_media_info;
 static struct ib_bearer ib_bearers[MAX_IB_BEARERS];
 static int ib_started;

 /**
  * ib_media_addr_set - initialize Infiniband media address structure
  *
  * Media-dependent "value" field stores MAC address in first 6 bytes
  * and zeroes out the remaining bytes.
  */
 static void ib_media_addr_set(const struct tipc_bearer *tb_ptr,
 			      struct tipc_media_addr *a, char *mac)
 {
 	BUILD_BUG_ON(sizeof(a->value) < INFINIBAND_ALEN);
 	memcpy(a->value, mac, INFINIBAND_ALEN);
 	a->media_id = TIPC_MEDIA_TYPE_IB;
 	a->broadcast = !memcmp(mac, tb_ptr->bcast_addr.value, INFINIBAND_ALEN);
 }

 /**
  * send_msg - send a TIPC message out over an InfiniBand interface
  */
 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
 		    struct tipc_media_addr *dest)
 {
 	struct sk_buff *clone;
 	struct net_device *dev;
 	int delta;

 	clone = skb_clone(buf, GFP_ATOMIC);
 	if (!clone)
 		return 0;

 	dev = ((struct ib_bearer *)(tb_ptr->usr_handle))->dev;
 	delta = dev->hard_header_len - skb_headroom(buf);

 	if ((delta > 0) &&
 	    pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
 		kfree_skb(clone);
 		return 0;
 	}

 	skb_reset_network_header(clone);
 	clone->dev = dev;
 	clone->protocol = htons(ETH_P_TIPC);
 	dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
 			dev->dev_addr, clone->len);
 	dev_queue_xmit(clone);
 	return 0;
 }

 /**
  * recv_msg - handle incoming TIPC message from an InfiniBand interface
  *
  * Accept only packets explicitly sent to this node, or broadcast packets;
  * ignores packets sent using InfiniBand multicast, and traffic sent to other
  * nodes (which can happen if interface is running in promiscuous mode).
  */
 static int recv_msg(struct sk_buff *buf, struct net_device *dev,
 		    struct packet_type *pt, struct net_device *orig_dev)
 {
 	struct ib_bearer *ib_ptr = (struct ib_bearer *)pt->af_packet_priv;

 	if (!net_eq(dev_net(dev), &init_net)) {
 		kfree_skb(buf);
 		return 0;
 	}

 	if (likely(ib_ptr->bearer)) {
 		if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
 			buf->next = NULL;
 			tipc_recv_msg(buf, ib_ptr->bearer);
 			return 0;
 		}
 	}
 	kfree_skb(buf);
 	return 0;
 }

 /**
  * setup_bearer - setup association between InfiniBand bearer and interface
  */
 static void setup_bearer(struct work_struct *work)
 {
 	struct ib_bearer *ib_ptr =
 		container_of(work, struct ib_bearer, setup);

 	dev_add_pack(&ib_ptr->tipc_packet_type);
 }

 /**
  * enable_bearer - attach TIPC bearer to an InfiniBand interface
  */
 static int enable_bearer(struct tipc_bearer *tb_ptr)
 {
 	struct net_device *dev = NULL;
 	struct net_device *pdev = NULL;
 	struct ib_bearer *ib_ptr = &ib_bearers[0];
 	struct ib_bearer *stop = &ib_bearers[MAX_IB_BEARERS];
 	char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
 	int pending_dev = 0;

 	/* Find unused InfiniBand bearer structure */
 	while (ib_ptr->dev) {
 		if (!ib_ptr->bearer)
 			pending_dev++;
 		if (++ib_ptr == stop)
 			return pending_dev ? -EAGAIN : -EDQUOT;
 	}

 	/* Find device with specified name */
 	read_lock(&dev_base_lock);
 	for_each_netdev(&init_net, pdev) {
 		if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) {
 			dev = pdev;
 			dev_hold(dev);
 			break;
 		}
 	}
 	read_unlock(&dev_base_lock);
 	if (!dev)
 		return -ENODEV;

 	/* Create InfiniBand bearer for device */
 	ib_ptr->dev = dev;
 	ib_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
 	ib_ptr->tipc_packet_type.dev = dev;
 	ib_ptr->tipc_packet_type.func = recv_msg;
 	ib_ptr->tipc_packet_type.af_packet_priv = ib_ptr;
 	INIT_LIST_HEAD(&(ib_ptr->tipc_packet_type.list));
 	INIT_WORK(&ib_ptr->setup, setup_bearer);
 	schedule_work(&ib_ptr->setup);

 	/* Associate TIPC bearer with InfiniBand bearer */
 	ib_ptr->bearer = tb_ptr;
 	tb_ptr->usr_handle = (void *)ib_ptr;
 	memset(tb_ptr->bcast_addr.value, 0, sizeof(tb_ptr->bcast_addr.value));
 	memcpy(tb_ptr->bcast_addr.value, dev->broadcast, INFINIBAND_ALEN);
 	tb_ptr->bcast_addr.media_id = TIPC_MEDIA_TYPE_IB;
 	tb_ptr->bcast_addr.broadcast = 1;
 	tb_ptr->mtu = dev->mtu;
 	tb_ptr->blocked = 0;
 	ib_media_addr_set(tb_ptr, &tb_ptr->addr, (char *)dev->dev_addr);
 	return 0;
 }

 /**
  * cleanup_bearer - break association between InfiniBand bearer and interface
  *
  * This routine must be invoked from a work queue because it can sleep.
  */
 static void cleanup_bearer(struct work_struct *work)
 {
 	struct ib_bearer *ib_ptr =
 		container_of(work, struct ib_bearer, cleanup);

 	dev_remove_pack(&ib_ptr->tipc_packet_type);
 	dev_put(ib_ptr->dev);
 	ib_ptr->dev = NULL;
 }

 /**
  * disable_bearer - detach TIPC bearer from an InfiniBand interface
  *
  * Mark InfiniBand bearer as inactive so that incoming buffers are thrown away,
  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
  * here because cleanup code needs to sleep and caller holds spinlocks.)
  */
 static void disable_bearer(struct tipc_bearer *tb_ptr)
 {
 	struct ib_bearer *ib_ptr = (struct ib_bearer *)tb_ptr->usr_handle;

 	ib_ptr->bearer = NULL;
 	INIT_WORK(&ib_ptr->cleanup, cleanup_bearer);
 	schedule_work(&ib_ptr->cleanup);
 }

 /**
  * recv_notification - handle device updates from OS
  *
  * Change the state of the InfiniBand bearer (if any) associated with the
  * specified device.
  */
 static int recv_notification(struct notifier_block *nb, unsigned long evt,
 			     void *dv)
 {
 	struct net_device *dev = (struct net_device *)dv;
 	struct ib_bearer *ib_ptr = &ib_bearers[0];
 	struct ib_bearer *stop = &ib_bearers[MAX_IB_BEARERS];

 	if (!net_eq(dev_net(dev), &init_net))
 		return NOTIFY_DONE;

 	while ((ib_ptr->dev != dev)) {
 		if (++ib_ptr == stop)
 			return NOTIFY_DONE;	/* couldn't find device */
 	}
 	if (!ib_ptr->bearer)
 		return NOTIFY_DONE;		/* bearer had been disabled */

 	ib_ptr->bearer->mtu = dev->mtu;

 	switch (evt) {
 	case NETDEV_CHANGE:
 		if (netif_carrier_ok(dev))
 			tipc_continue(ib_ptr->bearer);
 		else
 			tipc_block_bearer(ib_ptr->bearer->name);
 		break;
 	case NETDEV_UP:
 		tipc_continue(ib_ptr->bearer);
 		break;
 	case NETDEV_DOWN:
 		tipc_block_bearer(ib_ptr->bearer->name);
 		break;
 	case NETDEV_CHANGEMTU:
 	case NETDEV_CHANGEADDR:
 		tipc_block_bearer(ib_ptr->bearer->name);
 		tipc_continue(ib_ptr->bearer);
 		break;
 	case NETDEV_UNREGISTER:
 	case NETDEV_CHANGENAME:
 		tipc_disable_bearer(ib_ptr->bearer->name);
 		break;
 	}
 	return NOTIFY_OK;
 }

 static struct notifier_block notifier = {
 	.notifier_call	= recv_notification,
 	.priority	= 0,
 };

 /**
  * ib_addr2str - convert InfiniBand address to string
  */
 static int ib_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
 {
 	if (str_size < 60)	/* 60 = 19 * strlen("xx:") + strlen("xx\0") */
 		return 1;

 	sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:"
 			 "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
 		a->value[0], a->value[1], a->value[2], a->value[3],
 		a->value[4], a->value[5], a->value[6], a->value[7],
 		a->value[8], a->value[9], a->value[10], a->value[11],
 		a->value[12], a->value[13], a->value[14], a->value[15],
 		a->value[16], a->value[17], a->value[18], a->value[19]);

 	return 0;
 }

 /**
  * ib_addr2msg - convert InfiniBand address format to message header format
  */
 static int ib_addr2msg(struct tipc_media_addr *a, char *msg_area)
 {
 	memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
 	msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_IB;
 	memcpy(msg_area, a->value, INFINIBAND_ALEN);
 	return 0;
 }

 /**
  * ib_msg2addr - convert message header address format to InfiniBand format
  */
 static int ib_msg2addr(const struct tipc_bearer *tb_ptr,
 		       struct tipc_media_addr *a, char *msg_area)
 {
 	ib_media_addr_set(tb_ptr, a, msg_area);
 	return 0;
 }

 /*
  * InfiniBand media registration info
  */
 static struct tipc_media ib_media_info = {
 	.send_msg	= send_msg,
 	.enable_bearer	= enable_bearer,
 	.disable_bearer	= disable_bearer,
 	.addr2str	= ib_addr2str,
 	.addr2msg	= ib_addr2msg,
 	.msg2addr	= ib_msg2addr,
 	.priority	= TIPC_DEF_LINK_PRI,
 	.tolerance	= TIPC_DEF_LINK_TOL,
 	.window		= TIPC_DEF_LINK_WIN,
 	.type_id	= TIPC_MEDIA_TYPE_IB,
 	.name		= "ib"
 };

 /**
  * tipc_ib_media_start - activate InfiniBand bearer support
  *
  * Register InfiniBand media type with TIPC bearer code.  Also register
  * with OS for notifications about device state changes.
  */
 int tipc_ib_media_start(void)
 {
 	int res;

 	if (ib_started)
 		return -EINVAL;

 	res = tipc_register_media(&ib_media_info);
 	if (res)
 		return res;

 	res = register_netdevice_notifier(&notifier);
 	if (!res)
 		ib_started = 1;
 	return res;
 }

 /**
  * tipc_ib_media_stop - deactivate InfiniBand bearer support
  */
 void tipc_ib_media_stop(void)
 {
 	if (!ib_started)
 		return;

 	flush_scheduled_work();
 	unregister_netdevice_notifier(&notifier);
 	ib_started = 0;
 }
	/*
	* net/tipc/ib_media.c: Infiniband bearer support for TIPC
	*
	* Copyright (c) 2013 Patrick McHardy <kaber@trash.net>
	*
	* Based on eth_media.c, which carries the following copyright notice:
	*
	* Copyright (c) 2001-2007, Ericsson AB
	* Copyright (c) 2005-2008, 2011, Wind River Systems
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. 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.
	* 3. Neither the names of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* Alternatively, this software may be distributed under the terms of the
	* GNU General Public License ("GPL") version 2 as published by the Free
	* Software Foundation.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	* POSSIBILITY OF SUCH DAMAGE.
	*/

	#include <linux/if_infiniband.h>
	#include "core.h"
	#include "bearer.h"

	#define MAX_IB_BEARERS MAX_BEARERS

	/**
	* struct ib_bearer - Infiniband bearer data structure
	* @bearer: ptr to associated "generic" bearer structure
	* @dev: ptr to associated Infiniband network device
	* @tipc_packet_type: used in binding TIPC to Infiniband driver
	* @cleanup: work item used when disabling bearer
	*/

	struct ib_bearer {
	struct tipc_bearer *bearer;
	struct net_device *dev;
	struct packet_type tipc_packet_type;
	struct work_struct setup;
	struct work_struct cleanup;
	};

	static struct tipc_media ib_media_info;
	static struct ib_bearer ib_bearers[MAX_IB_BEARERS];
	static int ib_started;

	/**
	* ib_media_addr_set - initialize Infiniband media address structure
	*
	* Media-dependent "value" field stores MAC address in first 6 bytes
	* and zeroes out the remaining bytes.
	*/
	static void ib_media_addr_set(const struct tipc_bearer *tb_ptr,
	struct tipc_media_addr a, char mac)
	{
	BUILD_BUG_ON(sizeof(a->value) < INFINIBAND_ALEN);
	memcpy(a->value, mac, INFINIBAND_ALEN);
	a->media_id = TIPC_MEDIA_TYPE_IB;
	a->broadcast = !memcmp(mac, tb_ptr->bcast_addr.value, INFINIBAND_ALEN);
	}

	/**
	* send_msg - send a TIPC message out over an InfiniBand interface
	*/
	static int send_msg(struct sk_buff buf, struct tipc_bearer tb_ptr,
	struct tipc_media_addr *dest)
	{
	struct sk_buff *clone;
	struct net_device *dev;
	int delta;

	clone = skb_clone(buf, GFP_ATOMIC);
	if (!clone)
	return 0;

	dev = ((struct ib_bearer *)(tb_ptr->usr_handle))->dev;
	delta = dev->hard_header_len - skb_headroom(buf);

	if ((delta > 0) &&
	pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
	kfree_skb(clone);
	return 0;
	}

	skb_reset_network_header(clone);
	clone->dev = dev;
	clone->protocol = htons(ETH_P_TIPC);
	dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
	dev->dev_addr, clone->len);
	dev_queue_xmit(clone);
	return 0;
	}

	/**
	* recv_msg - handle incoming TIPC message from an InfiniBand interface
	*
	* Accept only packets explicitly sent to this node, or broadcast packets;
	* ignores packets sent using InfiniBand multicast, and traffic sent to other
	* nodes (which can happen if interface is running in promiscuous mode).
	*/
	static int recv_msg(struct sk_buff buf, struct net_device dev,
	struct packet_type pt, struct net_device orig_dev)
	{
	struct ib_bearer ib_ptr = (struct ib_bearer )pt->af_packet_priv;

	if (!net_eq(dev_net(dev), &init_net)) {
	kfree_skb(buf);
	return 0;
	}

	if (likely(ib_ptr->bearer)) {
	if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
	buf->next = NULL;
	tipc_recv_msg(buf, ib_ptr->bearer);
	return 0;
	}
	}
	kfree_skb(buf);
	return 0;
	}

	/**
	* setup_bearer - setup association between InfiniBand bearer and interface
	*/
	static void setup_bearer(struct work_struct *work)
	{
	struct ib_bearer *ib_ptr =
	container_of(work, struct ib_bearer, setup);

	dev_add_pack(&ib_ptr->tipc_packet_type);
	}

	/**
	* enable_bearer - attach TIPC bearer to an InfiniBand interface
	*/
	static int enable_bearer(struct tipc_bearer *tb_ptr)
	{
	struct net_device *dev = NULL;
	struct net_device *pdev = NULL;
	struct ib_bearer *ib_ptr = &ib_bearers[0];
	struct ib_bearer *stop = &ib_bearers[MAX_IB_BEARERS];
	char driver_name = strchr((const char )tb_ptr->name, ':') + 1;
	int pending_dev = 0;

	/* Find unused InfiniBand bearer structure */
	while (ib_ptr->dev) {
	if (!ib_ptr->bearer)
	pending_dev++;
	if (++ib_ptr == stop)
	return pending_dev ? -EAGAIN : -EDQUOT;
	}

	/* Find device with specified name */
	read_lock(&dev_base_lock);
	for_each_netdev(&init_net, pdev) {
	if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) {
	dev = pdev;
	dev_hold(dev);
	break;
	}
	}
	read_unlock(&dev_base_lock);
	if (!dev)
	return -ENODEV;

	/* Create InfiniBand bearer for device */
	ib_ptr->dev = dev;
	ib_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
	ib_ptr->tipc_packet_type.dev = dev;
	ib_ptr->tipc_packet_type.func = recv_msg;
	ib_ptr->tipc_packet_type.af_packet_priv = ib_ptr;
	INIT_LIST_HEAD(&(ib_ptr->tipc_packet_type.list));
	INIT_WORK(&ib_ptr->setup, setup_bearer);
	schedule_work(&ib_ptr->setup);

	/* Associate TIPC bearer with InfiniBand bearer */
	ib_ptr->bearer = tb_ptr;
	tb_ptr->usr_handle = (void *)ib_ptr;
	memset(tb_ptr->bcast_addr.value, 0, sizeof(tb_ptr->bcast_addr.value));
	memcpy(tb_ptr->bcast_addr.value, dev->broadcast, INFINIBAND_ALEN);
	tb_ptr->bcast_addr.media_id = TIPC_MEDIA_TYPE_IB;
	tb_ptr->bcast_addr.broadcast = 1;
	tb_ptr->mtu = dev->mtu;
	tb_ptr->blocked = 0;
	ib_media_addr_set(tb_ptr, &tb_ptr->addr, (char *)dev->dev_addr);
	return 0;
	}

	/**
	* cleanup_bearer - break association between InfiniBand bearer and interface
	*
	* This routine must be invoked from a work queue because it can sleep.
	*/
	static void cleanup_bearer(struct work_struct *work)
	{
	struct ib_bearer *ib_ptr =
	container_of(work, struct ib_bearer, cleanup);

	dev_remove_pack(&ib_ptr->tipc_packet_type);
	dev_put(ib_ptr->dev);
	ib_ptr->dev = NULL;
	}

	/**
	* disable_bearer - detach TIPC bearer from an InfiniBand interface
	*
	* Mark InfiniBand bearer as inactive so that incoming buffers are thrown away,
	* then get worker thread to complete bearer cleanup. (Can't do cleanup
	* here because cleanup code needs to sleep and caller holds spinlocks.)
	*/
	static void disable_bearer(struct tipc_bearer *tb_ptr)
	{
	struct ib_bearer ib_ptr = (struct ib_bearer )tb_ptr->usr_handle;

	ib_ptr->bearer = NULL;
	INIT_WORK(&ib_ptr->cleanup, cleanup_bearer);
	schedule_work(&ib_ptr->cleanup);
	}

	/**
	* recv_notification - handle device updates from OS
	*
	* Change the state of the InfiniBand bearer (if any) associated with the
	* specified device.
	*/
	static int recv_notification(struct notifier_block *nb, unsigned long evt,
	void *dv)
	{
	struct net_device dev = (struct net_device )dv;
	struct ib_bearer *ib_ptr = &ib_bearers[0];
	struct ib_bearer *stop = &ib_bearers[MAX_IB_BEARERS];

	if (!net_eq(dev_net(dev), &init_net))
	return NOTIFY_DONE;

	while ((ib_ptr->dev != dev)) {
	if (++ib_ptr == stop)
	return NOTIFY_DONE; /* couldn't find device */
	}
	if (!ib_ptr->bearer)
	return NOTIFY_DONE; /* bearer had been disabled */

	ib_ptr->bearer->mtu = dev->mtu;

	switch (evt) {
	case NETDEV_CHANGE:
	if (netif_carrier_ok(dev))
	tipc_continue(ib_ptr->bearer);
	else
	tipc_block_bearer(ib_ptr->bearer->name);
	break;
	case NETDEV_UP:
	tipc_continue(ib_ptr->bearer);
	break;
	case NETDEV_DOWN:
	tipc_block_bearer(ib_ptr->bearer->name);
	break;
	case NETDEV_CHANGEMTU:
	case NETDEV_CHANGEADDR:
	tipc_block_bearer(ib_ptr->bearer->name);
	tipc_continue(ib_ptr->bearer);
	break;
	case NETDEV_UNREGISTER:
	case NETDEV_CHANGENAME:
	tipc_disable_bearer(ib_ptr->bearer->name);
	break;
	}
	return NOTIFY_OK;
	}

	static struct notifier_block notifier = {
	.notifier_call = recv_notification,
	.priority = 0,
	};

	/**
	* ib_addr2str - convert InfiniBand address to string
	*/
	static int ib_addr2str(struct tipc_media_addr a, char str_buf, int str_size)
	{
	if (str_size < 60) /* 60 = 19 * strlen("xx:") + strlen("xx\0") */
	return 1;

	sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:"
	"%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
	a->value[0], a->value[1], a->value[2], a->value[3],
	a->value[4], a->value[5], a->value[6], a->value[7],
	a->value[8], a->value[9], a->value[10], a->value[11],
	a->value[12], a->value[13], a->value[14], a->value[15],
	a->value[16], a->value[17], a->value[18], a->value[19]);

	return 0;
	}

	/**
	* ib_addr2msg - convert InfiniBand address format to message header format
	*/
	static int ib_addr2msg(struct tipc_media_addr a, char msg_area)
	{
	memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
	msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_IB;
	memcpy(msg_area, a->value, INFINIBAND_ALEN);
	return 0;
	}

	/**
	* ib_msg2addr - convert message header address format to InfiniBand format
	*/
	static int ib_msg2addr(const struct tipc_bearer *tb_ptr,
	struct tipc_media_addr a, char msg_area)
	{
	ib_media_addr_set(tb_ptr, a, msg_area);
	return 0;
	}

	/*
	* InfiniBand media registration info
	*/
	static struct tipc_media ib_media_info = {
	.send_msg = send_msg,
	.enable_bearer = enable_bearer,
	.disable_bearer = disable_bearer,
	.addr2str = ib_addr2str,
	.addr2msg = ib_addr2msg,
	.msg2addr = ib_msg2addr,
	.priority = TIPC_DEF_LINK_PRI,
	.tolerance = TIPC_DEF_LINK_TOL,
	.window = TIPC_DEF_LINK_WIN,
	.type_id = TIPC_MEDIA_TYPE_IB,
	.name = "ib"
	};

	/**
	* tipc_ib_media_start - activate InfiniBand bearer support
	*
	* Register InfiniBand media type with TIPC bearer code. Also register
	* with OS for notifications about device state changes.
	*/
	int tipc_ib_media_start(void)
	{
	int res;

	if (ib_started)
	return -EINVAL;

	res = tipc_register_media(&ib_media_info);
	if (res)
	return res;

	res = register_netdevice_notifier(&notifier);
	if (!res)
	ib_started = 1;
	return res;
	}

	/**
	* tipc_ib_media_stop - deactivate InfiniBand bearer support
	*/
	void tipc_ib_media_stop(void)
	{
	if (!ib_started)
	return;

	flush_scheduled_work();
	unregister_netdevice_notifier(&notifier);
	ib_started = 0;
	}