drivers/infiniband/hw/mthca/mthca_mad.c - kernel/prism - Git at Google

 /*
  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
  * Copyright (c) 2005 Mellanox Technologies. 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 <linux/string.h>
 #include <linux/slab.h>

 #include <rdma/ib_verbs.h>
 #include <rdma/ib_mad.h>
 #include <rdma/ib_smi.h>

 #include "mthca_dev.h"
 #include "mthca_cmd.h"

 enum {
 	MTHCA_VENDOR_CLASS1 = 0x9,
 	MTHCA_VENDOR_CLASS2 = 0xa
 };

 static int mthca_update_rate(struct mthca_dev *dev, u8 port_num)
 {
 	struct ib_port_attr *tprops = NULL;
 	int                  ret;

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

 	ret = ib_query_port(&dev->ib_dev, port_num, tprops);
 	if (ret) {
 		printk(KERN_WARNING "ib_query_port failed (%d) for %s port %d\n",
 		       ret, dev->ib_dev.name, port_num);
 		goto out;
 	}

 	dev->rate[port_num - 1] = tprops->active_speed *
 				  ib_width_enum_to_int(tprops->active_width);

 out:
 	kfree(tprops);
 	return ret;
 }

 static void update_sm_ah(struct mthca_dev *dev,
 			 u8 port_num, u16 lid, u8 sl)
 {
 	struct ib_ah *new_ah;
 	struct ib_ah_attr ah_attr;
 	unsigned long flags;

 	if (!dev->send_agent[port_num - 1][0])
 		return;

 	memset(&ah_attr, 0, sizeof ah_attr);
 	ah_attr.dlid     = lid;
 	ah_attr.sl       = sl;
 	ah_attr.port_num = port_num;

 	new_ah = ib_create_ah(dev->send_agent[port_num - 1][0]->qp->pd,
 			      &ah_attr);
 	if (IS_ERR(new_ah))
 		return;

 	spin_lock_irqsave(&dev->sm_lock, flags);
 	if (dev->sm_ah[port_num - 1])
 		ib_destroy_ah(dev->sm_ah[port_num - 1]);
 	dev->sm_ah[port_num - 1] = new_ah;
 	spin_unlock_irqrestore(&dev->sm_lock, flags);
 }

 /*
  * Snoop SM MADs for port info and P_Key table sets, so we can
  * synthesize LID change and P_Key change events.
  */
 static void smp_snoop(struct ib_device *ibdev,
 		      u8 port_num,
 		      struct ib_mad *mad,
 		      u16 prev_lid)
 {
 	struct ib_event event;

 	if ((mad->mad_hdr.mgmt_class  == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
 	     mad->mad_hdr.mgmt_class  == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
 	    mad->mad_hdr.method     == IB_MGMT_METHOD_SET) {
 		if (mad->mad_hdr.attr_id == IB_SMP_ATTR_PORT_INFO) {
 			struct ib_port_info *pinfo =
 				(struct ib_port_info *) ((struct ib_smp *) mad)->data;
 			u16 lid = be16_to_cpu(pinfo->lid);

 			mthca_update_rate(to_mdev(ibdev), port_num);
 			update_sm_ah(to_mdev(ibdev), port_num,
 				     be16_to_cpu(pinfo->sm_lid),
 				     pinfo->neighbormtu_mastersmsl & 0xf);

 			event.device           = ibdev;
 			event.element.port_num = port_num;

 			if (pinfo->clientrereg_resv_subnetto & 0x80) {
 				event.event    = IB_EVENT_CLIENT_REREGISTER;
 				ib_dispatch_event(&event);
 			}

 			if (prev_lid != lid) {
 				event.event    = IB_EVENT_LID_CHANGE;
 				ib_dispatch_event(&event);
 			}
 		}

 		if (mad->mad_hdr.attr_id == IB_SMP_ATTR_PKEY_TABLE) {
 			event.device           = ibdev;
 			event.event            = IB_EVENT_PKEY_CHANGE;
 			event.element.port_num = port_num;
 			ib_dispatch_event(&event);
 		}
 	}
 }

 static void node_desc_override(struct ib_device *dev,
 			       struct ib_mad *mad)
 {
 	if ((mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
 	     mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
 	    mad->mad_hdr.method == IB_MGMT_METHOD_GET_RESP &&
 	    mad->mad_hdr.attr_id == IB_SMP_ATTR_NODE_DESC) {
 		mutex_lock(&to_mdev(dev)->cap_mask_mutex);
 		memcpy(((struct ib_smp *) mad)->data, dev->node_desc, 64);
 		mutex_unlock(&to_mdev(dev)->cap_mask_mutex);
 	}
 }

 static void forward_trap(struct mthca_dev *dev,
 			 u8 port_num,
 			 struct ib_mad *mad)
 {
 	int qpn = mad->mad_hdr.mgmt_class != IB_MGMT_CLASS_SUBN_LID_ROUTED;
 	struct ib_mad_send_buf *send_buf;
 	struct ib_mad_agent *agent = dev->send_agent[port_num - 1][qpn];
 	int ret;
 	unsigned long flags;

 	if (agent) {
 		send_buf = ib_create_send_mad(agent, qpn, 0, 0, IB_MGMT_MAD_HDR,
 					      IB_MGMT_MAD_DATA, GFP_ATOMIC);
 		/*
 		 * We rely here on the fact that MLX QPs don't use the
 		 * address handle after the send is posted (this is
 		 * wrong following the IB spec strictly, but we know
 		 * it's OK for our devices).
 		 */
 		spin_lock_irqsave(&dev->sm_lock, flags);
 		memcpy(send_buf->mad, mad, sizeof *mad);
 		if ((send_buf->ah = dev->sm_ah[port_num - 1]))
 			ret = ib_post_send_mad(send_buf, NULL);
 		else
 			ret = -EINVAL;
 		spin_unlock_irqrestore(&dev->sm_lock, flags);

 		if (ret)
 			ib_free_send_mad(send_buf);
 	}
 }

 int mthca_process_mad(struct ib_device *ibdev,
 		      int mad_flags,
 		      u8 port_num,
 		      struct ib_wc *in_wc,
 		      struct ib_grh *in_grh,
 		      struct ib_mad *in_mad,
 		      struct ib_mad *out_mad)
 {
 	int err;
 	u8 status;
 	u16 slid = in_wc ? in_wc->slid : be16_to_cpu(IB_LID_PERMISSIVE);
 	u16 prev_lid = 0;
 	struct ib_port_attr pattr;

 	/* Forward locally generated traps to the SM */
 	if (in_mad->mad_hdr.method == IB_MGMT_METHOD_TRAP &&
 	    slid == 0) {
 		forward_trap(to_mdev(ibdev), port_num, in_mad);
 		return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;
 	}

 	/*
 	 * Only handle SM gets, sets and trap represses for SM class
 	 *
 	 * Only handle PMA and Mellanox vendor-specific class gets and
 	 * sets for other classes.
 	 */
 	if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
 	    in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
 		if (in_mad->mad_hdr.method   != IB_MGMT_METHOD_GET &&
 		    in_mad->mad_hdr.method   != IB_MGMT_METHOD_SET &&
 		    in_mad->mad_hdr.method   != IB_MGMT_METHOD_TRAP_REPRESS)
 			return IB_MAD_RESULT_SUCCESS;

 		/*
 		 * Don't process SMInfo queries or vendor-specific
 		 * MADs -- the SMA can't handle them.
 		 */
 		if (in_mad->mad_hdr.attr_id == IB_SMP_ATTR_SM_INFO ||
 		    ((in_mad->mad_hdr.attr_id & IB_SMP_ATTR_VENDOR_MASK) ==
 		     IB_SMP_ATTR_VENDOR_MASK))
 			return IB_MAD_RESULT_SUCCESS;
 	} else if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT ||
 		   in_mad->mad_hdr.mgmt_class == MTHCA_VENDOR_CLASS1     ||
 		   in_mad->mad_hdr.mgmt_class == MTHCA_VENDOR_CLASS2) {
 		if (in_mad->mad_hdr.method  != IB_MGMT_METHOD_GET &&
 		    in_mad->mad_hdr.method  != IB_MGMT_METHOD_SET)
 			return IB_MAD_RESULT_SUCCESS;
 	} else
 		return IB_MAD_RESULT_SUCCESS;
 	if ((in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
 	     in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
 	    in_mad->mad_hdr.method == IB_MGMT_METHOD_SET &&
 	    in_mad->mad_hdr.attr_id == IB_SMP_ATTR_PORT_INFO &&
 	    !ib_query_port(ibdev, port_num, &pattr))
 		prev_lid = pattr.lid;

 	err = mthca_MAD_IFC(to_mdev(ibdev),
 			    mad_flags & IB_MAD_IGNORE_MKEY,
 			    mad_flags & IB_MAD_IGNORE_BKEY,
 			    port_num, in_wc, in_grh, in_mad, out_mad,
 			    &status);
 	if (err) {
 		mthca_err(to_mdev(ibdev), "MAD_IFC failed\n");
 		return IB_MAD_RESULT_FAILURE;
 	}
 	if (status == MTHCA_CMD_STAT_BAD_PKT)
 		return IB_MAD_RESULT_SUCCESS;
 	if (status) {
 		mthca_err(to_mdev(ibdev), "MAD_IFC returned status %02x\n",
 			  status);
 		return IB_MAD_RESULT_FAILURE;
 	}

 	if (!out_mad->mad_hdr.status) {
 		smp_snoop(ibdev, port_num, in_mad, prev_lid);
 		node_desc_override(ibdev, out_mad);
 	}

 	/* set return bit in status of directed route responses */
 	if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
 		out_mad->mad_hdr.status |= cpu_to_be16(1 << 15);

 	if (in_mad->mad_hdr.method == IB_MGMT_METHOD_TRAP_REPRESS)
 		/* no response for trap repress */
 		return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;

 	return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY;
 }

 static void send_handler(struct ib_mad_agent *agent,
 			 struct ib_mad_send_wc *mad_send_wc)
 {
 	ib_free_send_mad(mad_send_wc->send_buf);
 }

 int mthca_create_agents(struct mthca_dev *dev)
 {
 	struct ib_mad_agent *agent;
 	int p, q;
 	int ret;

 	spin_lock_init(&dev->sm_lock);

 	for (p = 0; p < dev->limits.num_ports; ++p)
 		for (q = 0; q <= 1; ++q) {
 			agent = ib_register_mad_agent(&dev->ib_dev, p + 1,
 						      q ? IB_QPT_GSI : IB_QPT_SMI,
 						      NULL, 0, send_handler,
 						      NULL, NULL);
 			if (IS_ERR(agent)) {
 				ret = PTR_ERR(agent);
 				goto err;
 			}
 			dev->send_agent[p][q] = agent;
 		}


 	for (p = 1; p <= dev->limits.num_ports; ++p) {
 		ret = mthca_update_rate(dev, p);
 		if (ret) {
 			mthca_err(dev, "Failed to obtain port %d rate."
 				  " aborting.\n", p);
 			goto err;
 		}
 	}

 	return 0;

 err:
 	for (p = 0; p < dev->limits.num_ports; ++p)
 		for (q = 0; q <= 1; ++q)
 			if (dev->send_agent[p][q])
 				ib_unregister_mad_agent(dev->send_agent[p][q]);

 	return ret;
 }

 void mthca_free_agents(struct mthca_dev *dev)
 {
 	struct ib_mad_agent *agent;
 	int p, q;

 	for (p = 0; p < dev->limits.num_ports; ++p) {
 		for (q = 0; q <= 1; ++q) {
 			agent = dev->send_agent[p][q];
 			dev->send_agent[p][q] = NULL;
 			ib_unregister_mad_agent(agent);
 		}

 		if (dev->sm_ah[p])
 			ib_destroy_ah(dev->sm_ah[p]);
 	}
 }
	/*
	* Copyright (c) 2004 Topspin Communications. All rights reserved.
	* Copyright (c) 2005 Mellanox Technologies. 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 <linux/string.h>
	#include <linux/slab.h>

	#include <rdma/ib_verbs.h>
	#include <rdma/ib_mad.h>
	#include <rdma/ib_smi.h>

	#include "mthca_dev.h"
	#include "mthca_cmd.h"

	enum {
	MTHCA_VENDOR_CLASS1 = 0x9,
	MTHCA_VENDOR_CLASS2 = 0xa
	};

	static int mthca_update_rate(struct mthca_dev *dev, u8 port_num)
	{
	struct ib_port_attr *tprops = NULL;
	int ret;

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

	ret = ib_query_port(&dev->ib_dev, port_num, tprops);
	if (ret) {
	printk(KERN_WARNING "ib_query_port failed (%d) for %s port %d\n",
	ret, dev->ib_dev.name, port_num);
	goto out;
	}

	dev->rate[port_num - 1] = tprops->active_speed *
	ib_width_enum_to_int(tprops->active_width);

	out:
	kfree(tprops);
	return ret;
	}

	static void update_sm_ah(struct mthca_dev *dev,
	u8 port_num, u16 lid, u8 sl)
	{
	struct ib_ah *new_ah;
	struct ib_ah_attr ah_attr;
	unsigned long flags;

	if (!dev->send_agent[port_num - 1][0])
	return;

	memset(&ah_attr, 0, sizeof ah_attr);
	ah_attr.dlid = lid;
	ah_attr.sl = sl;
	ah_attr.port_num = port_num;

	new_ah = ib_create_ah(dev->send_agent[port_num - 1][0]->qp->pd,
	&ah_attr);
	if (IS_ERR(new_ah))
	return;

	spin_lock_irqsave(&dev->sm_lock, flags);
	if (dev->sm_ah[port_num - 1])
	ib_destroy_ah(dev->sm_ah[port_num - 1]);
	dev->sm_ah[port_num - 1] = new_ah;
	spin_unlock_irqrestore(&dev->sm_lock, flags);
	}

	/*
	* Snoop SM MADs for port info and P_Key table sets, so we can
	* synthesize LID change and P_Key change events.
	*/
	static void smp_snoop(struct ib_device *ibdev,
	u8 port_num,
	struct ib_mad *mad,
	u16 prev_lid)
	{
	struct ib_event event;

	if ((mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED \|\|
	mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
	mad->mad_hdr.method == IB_MGMT_METHOD_SET) {
	if (mad->mad_hdr.attr_id == IB_SMP_ATTR_PORT_INFO) {
	struct ib_port_info *pinfo =
	(struct ib_port_info ) ((struct ib_smp ) mad)->data;
	u16 lid = be16_to_cpu(pinfo->lid);

	mthca_update_rate(to_mdev(ibdev), port_num);
	update_sm_ah(to_mdev(ibdev), port_num,
	be16_to_cpu(pinfo->sm_lid),
	pinfo->neighbormtu_mastersmsl & 0xf);

	event.device = ibdev;
	event.element.port_num = port_num;

	if (pinfo->clientrereg_resv_subnetto & 0x80) {
	event.event = IB_EVENT_CLIENT_REREGISTER;
	ib_dispatch_event(&event);
	}

	if (prev_lid != lid) {
	event.event = IB_EVENT_LID_CHANGE;
	ib_dispatch_event(&event);
	}
	}

	if (mad->mad_hdr.attr_id == IB_SMP_ATTR_PKEY_TABLE) {
	event.device = ibdev;
	event.event = IB_EVENT_PKEY_CHANGE;
	event.element.port_num = port_num;
	ib_dispatch_event(&event);
	}
	}
	}

	static void node_desc_override(struct ib_device *dev,
	struct ib_mad *mad)
	{
	if ((mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED \|\|
	mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
	mad->mad_hdr.method == IB_MGMT_METHOD_GET_RESP &&
	mad->mad_hdr.attr_id == IB_SMP_ATTR_NODE_DESC) {
	mutex_lock(&to_mdev(dev)->cap_mask_mutex);
	memcpy(((struct ib_smp *) mad)->data, dev->node_desc, 64);
	mutex_unlock(&to_mdev(dev)->cap_mask_mutex);
	}
	}

	static void forward_trap(struct mthca_dev *dev,
	u8 port_num,
	struct ib_mad *mad)
	{
	int qpn = mad->mad_hdr.mgmt_class != IB_MGMT_CLASS_SUBN_LID_ROUTED;
	struct ib_mad_send_buf *send_buf;
	struct ib_mad_agent *agent = dev->send_agent[port_num - 1][qpn];
	int ret;
	unsigned long flags;

	if (agent) {
	send_buf = ib_create_send_mad(agent, qpn, 0, 0, IB_MGMT_MAD_HDR,
	IB_MGMT_MAD_DATA, GFP_ATOMIC);
	/*
	* We rely here on the fact that MLX QPs don't use the
	* address handle after the send is posted (this is
	* wrong following the IB spec strictly, but we know
	* it's OK for our devices).
	*/
	spin_lock_irqsave(&dev->sm_lock, flags);
	memcpy(send_buf->mad, mad, sizeof *mad);
	if ((send_buf->ah = dev->sm_ah[port_num - 1]))
	ret = ib_post_send_mad(send_buf, NULL);
	else
	ret = -EINVAL;
	spin_unlock_irqrestore(&dev->sm_lock, flags);

	if (ret)
	ib_free_send_mad(send_buf);
	}
	}

	int mthca_process_mad(struct ib_device *ibdev,
	int mad_flags,
	u8 port_num,
	struct ib_wc *in_wc,
	struct ib_grh *in_grh,
	struct ib_mad *in_mad,
	struct ib_mad *out_mad)
	{
	int err;
	u8 status;
	u16 slid = in_wc ? in_wc->slid : be16_to_cpu(IB_LID_PERMISSIVE);
	u16 prev_lid = 0;
	struct ib_port_attr pattr;

	/* Forward locally generated traps to the SM */
	if (in_mad->mad_hdr.method == IB_MGMT_METHOD_TRAP &&
	slid == 0) {
	forward_trap(to_mdev(ibdev), port_num, in_mad);
	return IB_MAD_RESULT_SUCCESS \| IB_MAD_RESULT_CONSUMED;
	}

	/*
	* Only handle SM gets, sets and trap represses for SM class
	*
	* Only handle PMA and Mellanox vendor-specific class gets and
	* sets for other classes.
	*/
	if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED \|\|
	in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
	if (in_mad->mad_hdr.method != IB_MGMT_METHOD_GET &&
	in_mad->mad_hdr.method != IB_MGMT_METHOD_SET &&
	in_mad->mad_hdr.method != IB_MGMT_METHOD_TRAP_REPRESS)
	return IB_MAD_RESULT_SUCCESS;

	/*
	* Don't process SMInfo queries or vendor-specific
	* MADs -- the SMA can't handle them.
	*/
	if (in_mad->mad_hdr.attr_id == IB_SMP_ATTR_SM_INFO \|\|
	((in_mad->mad_hdr.attr_id & IB_SMP_ATTR_VENDOR_MASK) ==
	IB_SMP_ATTR_VENDOR_MASK))
	return IB_MAD_RESULT_SUCCESS;
	} else if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT \|\|
	in_mad->mad_hdr.mgmt_class == MTHCA_VENDOR_CLASS1 \|\|
	in_mad->mad_hdr.mgmt_class == MTHCA_VENDOR_CLASS2) {
	if (in_mad->mad_hdr.method != IB_MGMT_METHOD_GET &&
	in_mad->mad_hdr.method != IB_MGMT_METHOD_SET)
	return IB_MAD_RESULT_SUCCESS;
	} else
	return IB_MAD_RESULT_SUCCESS;
	if ((in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED \|\|
	in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
	in_mad->mad_hdr.method == IB_MGMT_METHOD_SET &&
	in_mad->mad_hdr.attr_id == IB_SMP_ATTR_PORT_INFO &&
	!ib_query_port(ibdev, port_num, &pattr))
	prev_lid = pattr.lid;

	err = mthca_MAD_IFC(to_mdev(ibdev),
	mad_flags & IB_MAD_IGNORE_MKEY,
	mad_flags & IB_MAD_IGNORE_BKEY,
	port_num, in_wc, in_grh, in_mad, out_mad,
	&status);
	if (err) {
	mthca_err(to_mdev(ibdev), "MAD_IFC failed\n");
	return IB_MAD_RESULT_FAILURE;
	}
	if (status == MTHCA_CMD_STAT_BAD_PKT)
	return IB_MAD_RESULT_SUCCESS;
	if (status) {
	mthca_err(to_mdev(ibdev), "MAD_IFC returned status %02x\n",
	status);
	return IB_MAD_RESULT_FAILURE;
	}

	if (!out_mad->mad_hdr.status) {
	smp_snoop(ibdev, port_num, in_mad, prev_lid);
	node_desc_override(ibdev, out_mad);
	}

	/* set return bit in status of directed route responses */
	if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
	out_mad->mad_hdr.status \|= cpu_to_be16(1 << 15);

	if (in_mad->mad_hdr.method == IB_MGMT_METHOD_TRAP_REPRESS)
	/* no response for trap repress */
	return IB_MAD_RESULT_SUCCESS \| IB_MAD_RESULT_CONSUMED;

	return IB_MAD_RESULT_SUCCESS \| IB_MAD_RESULT_REPLY;
	}

	static void send_handler(struct ib_mad_agent *agent,
	struct ib_mad_send_wc *mad_send_wc)
	{
	ib_free_send_mad(mad_send_wc->send_buf);
	}

	int mthca_create_agents(struct mthca_dev *dev)
	{
	struct ib_mad_agent *agent;
	int p, q;
	int ret;

	spin_lock_init(&dev->sm_lock);

	for (p = 0; p < dev->limits.num_ports; ++p)
	for (q = 0; q <= 1; ++q) {
	agent = ib_register_mad_agent(&dev->ib_dev, p + 1,
	q ? IB_QPT_GSI : IB_QPT_SMI,
	NULL, 0, send_handler,
	NULL, NULL);
	if (IS_ERR(agent)) {
	ret = PTR_ERR(agent);
	goto err;
	}
	dev->send_agent[p][q] = agent;
	}


	for (p = 1; p <= dev->limits.num_ports; ++p) {
	ret = mthca_update_rate(dev, p);
	if (ret) {
	mthca_err(dev, "Failed to obtain port %d rate."
	" aborting.\n", p);
	goto err;
	}
	}

	return 0;

	err:
	for (p = 0; p < dev->limits.num_ports; ++p)
	for (q = 0; q <= 1; ++q)
	if (dev->send_agent[p][q])
	ib_unregister_mad_agent(dev->send_agent[p][q]);

	return ret;
	}

	void mthca_free_agents(struct mthca_dev *dev)
	{
	struct ib_mad_agent *agent;
	int p, q;

	for (p = 0; p < dev->limits.num_ports; ++p) {
	for (q = 0; q <= 1; ++q) {
	agent = dev->send_agent[p][q];
	dev->send_agent[p][q] = NULL;
	ib_unregister_mad_agent(agent);
	}

	if (dev->sm_ah[p])
	ib_destroy_ah(dev->sm_ah[p]);
	}
	}