drivers/infiniband/hw/mlx4/cm.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (c) 2012 Mellanox Technologies. 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 <rdma/ib_mad.h>

 #include <linux/mlx4/cmd.h>
 #include <linux/rbtree.h>
 #include <linux/idr.h>
 #include <rdma/ib_cm.h>

 #include "mlx4_ib.h"

 #define CM_CLEANUP_CACHE_TIMEOUT  (5 * HZ)

 struct id_map_entry {
 	struct rb_node node;

 	u32 sl_cm_id;
 	u32 pv_cm_id;
 	int slave_id;
 	int scheduled_delete;
 	struct mlx4_ib_dev *dev;

 	struct list_head list;
 	struct delayed_work timeout;
 };

 struct cm_generic_msg {
 	struct ib_mad_hdr hdr;

 	__be32 local_comm_id;
 	__be32 remote_comm_id;
 };

 struct cm_req_msg {
 	unsigned char unused[0x60];
 	union ib_gid primary_path_sgid;
 };


 static void set_local_comm_id(struct ib_mad *mad, u32 cm_id)
 {
 	struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
 	msg->local_comm_id = cpu_to_be32(cm_id);
 }

 static u32 get_local_comm_id(struct ib_mad *mad)
 {
 	struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;

 	return be32_to_cpu(msg->local_comm_id);
 }

 static void set_remote_comm_id(struct ib_mad *mad, u32 cm_id)
 {
 	struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
 	msg->remote_comm_id = cpu_to_be32(cm_id);
 }

 static u32 get_remote_comm_id(struct ib_mad *mad)
 {
 	struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;

 	return be32_to_cpu(msg->remote_comm_id);
 }

 static union ib_gid gid_from_req_msg(struct ib_device *ibdev, struct ib_mad *mad)
 {
 	struct cm_req_msg *msg = (struct cm_req_msg *)mad;

 	return msg->primary_path_sgid;
 }

 /* Lock should be taken before called */
 static struct id_map_entry *
 id_map_find_by_sl_id(struct ib_device *ibdev, u32 slave_id, u32 sl_cm_id)
 {
 	struct rb_root *sl_id_map = &to_mdev(ibdev)->sriov.sl_id_map;
 	struct rb_node *node = sl_id_map->rb_node;

 	while (node) {
 		struct id_map_entry *id_map_entry =
 			rb_entry(node, struct id_map_entry, node);

 		if (id_map_entry->sl_cm_id > sl_cm_id)
 			node = node->rb_left;
 		else if (id_map_entry->sl_cm_id < sl_cm_id)
 			node = node->rb_right;
 		else if (id_map_entry->slave_id > slave_id)
 			node = node->rb_left;
 		else if (id_map_entry->slave_id < slave_id)
 			node = node->rb_right;
 		else
 			return id_map_entry;
 	}
 	return NULL;
 }

 static void id_map_ent_timeout(struct work_struct *work)
 {
 	struct delayed_work *delay = to_delayed_work(work);
 	struct id_map_entry *ent = container_of(delay, struct id_map_entry, timeout);
 	struct id_map_entry *db_ent, *found_ent;
 	struct mlx4_ib_dev *dev = ent->dev;
 	struct mlx4_ib_sriov *sriov = &dev->sriov;
 	struct rb_root *sl_id_map = &sriov->sl_id_map;
 	int pv_id = (int) ent->pv_cm_id;

 	spin_lock(&sriov->id_map_lock);
 	db_ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, pv_id);
 	if (!db_ent)
 		goto out;
 	found_ent = id_map_find_by_sl_id(&dev->ib_dev, ent->slave_id, ent->sl_cm_id);
 	if (found_ent && found_ent == ent)
 		rb_erase(&found_ent->node, sl_id_map);
 	idr_remove(&sriov->pv_id_table, pv_id);

 out:
 	list_del(&ent->list);
 	spin_unlock(&sriov->id_map_lock);
 	kfree(ent);
 }

 static void id_map_find_del(struct ib_device *ibdev, int pv_cm_id)
 {
 	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
 	struct rb_root *sl_id_map = &sriov->sl_id_map;
 	struct id_map_entry *ent, *found_ent;

 	spin_lock(&sriov->id_map_lock);
 	ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, pv_cm_id);
 	if (!ent)
 		goto out;
 	found_ent = id_map_find_by_sl_id(ibdev, ent->slave_id, ent->sl_cm_id);
 	if (found_ent && found_ent == ent)
 		rb_erase(&found_ent->node, sl_id_map);
 	idr_remove(&sriov->pv_id_table, pv_cm_id);
 out:
 	spin_unlock(&sriov->id_map_lock);
 }

 static void sl_id_map_add(struct ib_device *ibdev, struct id_map_entry *new)
 {
 	struct rb_root *sl_id_map = &to_mdev(ibdev)->sriov.sl_id_map;
 	struct rb_node **link = &sl_id_map->rb_node, *parent = NULL;
 	struct id_map_entry *ent;
 	int slave_id = new->slave_id;
 	int sl_cm_id = new->sl_cm_id;

 	ent = id_map_find_by_sl_id(ibdev, slave_id, sl_cm_id);
 	if (ent) {
 		pr_debug("overriding existing sl_id_map entry (cm_id = %x)\n",
 			 sl_cm_id);

 		rb_replace_node(&ent->node, &new->node, sl_id_map);
 		return;
 	}

 	/* Go to the bottom of the tree */
 	while (*link) {
 		parent = *link;
 		ent = rb_entry(parent, struct id_map_entry, node);

 		if (ent->sl_cm_id > sl_cm_id || (ent->sl_cm_id == sl_cm_id && ent->slave_id > slave_id))
 			link = &(*link)->rb_left;
 		else
 			link = &(*link)->rb_right;
 	}

 	rb_link_node(&new->node, parent, link);
 	rb_insert_color(&new->node, sl_id_map);
 }

 static struct id_map_entry *
 id_map_alloc(struct ib_device *ibdev, int slave_id, u32 sl_cm_id)
 {
 	int ret, id;
 	static int next_id;
 	struct id_map_entry *ent;
 	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;

 	ent = kmalloc(sizeof (struct id_map_entry), GFP_KERNEL);
 	if (!ent) {
 		mlx4_ib_warn(ibdev, "Couldn't allocate id cache entry - out of memory\n");
 		return ERR_PTR(-ENOMEM);
 	}

 	ent->sl_cm_id = sl_cm_id;
 	ent->slave_id = slave_id;
 	ent->scheduled_delete = 0;
 	ent->dev = to_mdev(ibdev);
 	INIT_DELAYED_WORK(&ent->timeout, id_map_ent_timeout);

 	do {
 		spin_lock(&to_mdev(ibdev)->sriov.id_map_lock);
 		ret = idr_get_new_above(&sriov->pv_id_table, ent,
 					next_id, &id);
 		if (!ret) {
 			next_id = ((unsigned) id + 1) & MAX_IDR_MASK;
 			ent->pv_cm_id = (u32)id;
 			sl_id_map_add(ibdev, ent);
 		}

 		spin_unlock(&sriov->id_map_lock);
 	} while (ret == -EAGAIN && idr_pre_get(&sriov->pv_id_table, GFP_KERNEL));
 	/*the function idr_get_new_above can return -ENOSPC, so don't insert in that case.*/
 	if (!ret) {
 		spin_lock(&sriov->id_map_lock);
 		list_add_tail(&ent->list, &sriov->cm_list);
 		spin_unlock(&sriov->id_map_lock);
 		return ent;
 	}
 	/*error flow*/
 	kfree(ent);
 	mlx4_ib_warn(ibdev, "No more space in the idr (err:0x%x)\n", ret);
 	return ERR_PTR(-ENOMEM);
 }

 static struct id_map_entry *
 id_map_get(struct ib_device *ibdev, int *pv_cm_id, int sl_cm_id, int slave_id)
 {
 	struct id_map_entry *ent;
 	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;

 	spin_lock(&sriov->id_map_lock);
 	if (*pv_cm_id == -1) {
 		ent = id_map_find_by_sl_id(ibdev, sl_cm_id, slave_id);
 		if (ent)
 			*pv_cm_id = (int) ent->pv_cm_id;
 	} else
 		ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, *pv_cm_id);
 	spin_unlock(&sriov->id_map_lock);

 	return ent;
 }

 static void schedule_delayed(struct ib_device *ibdev, struct id_map_entry *id)
 {
 	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
 	unsigned long flags;

 	spin_lock(&sriov->id_map_lock);
 	spin_lock_irqsave(&sriov->going_down_lock, flags);
 	/*make sure that there is no schedule inside the scheduled work.*/
 	if (!sriov->is_going_down) {
 		id->scheduled_delete = 1;
 		schedule_delayed_work(&id->timeout, CM_CLEANUP_CACHE_TIMEOUT);
 	}
 	spin_unlock_irqrestore(&sriov->going_down_lock, flags);
 	spin_unlock(&sriov->id_map_lock);
 }

 int mlx4_ib_multiplex_cm_handler(struct ib_device *ibdev, int port, int slave_id,
 		struct ib_mad *mad)
 {
 	struct id_map_entry *id;
 	u32 sl_cm_id;
 	int pv_cm_id = -1;

 	sl_cm_id = get_local_comm_id(mad);

 	if (mad->mad_hdr.attr_id == CM_REQ_ATTR_ID ||
 			mad->mad_hdr.attr_id == CM_REP_ATTR_ID) {
 		id = id_map_alloc(ibdev, slave_id, sl_cm_id);
 		if (IS_ERR(id)) {
 			mlx4_ib_warn(ibdev, "%s: id{slave: %d, sl_cm_id: 0x%x} Failed to id_map_alloc\n",
 				__func__, slave_id, sl_cm_id);
 			return PTR_ERR(id);
 		}
 	} else if (mad->mad_hdr.attr_id == CM_REJ_ATTR_ID) {
 		return 0;
 	} else {
 		id = id_map_get(ibdev, &pv_cm_id, slave_id, sl_cm_id);
 	}

 	if (!id) {
 		pr_debug("id{slave: %d, sl_cm_id: 0x%x} is NULL!\n",
 			 slave_id, sl_cm_id);
 		return -EINVAL;
 	}

 	set_local_comm_id(mad, id->pv_cm_id);

 	if (mad->mad_hdr.attr_id == CM_DREQ_ATTR_ID)
 		schedule_delayed(ibdev, id);
 	else if (mad->mad_hdr.attr_id == CM_DREP_ATTR_ID)
 		id_map_find_del(ibdev, pv_cm_id);

 	return 0;
 }

 int mlx4_ib_demux_cm_handler(struct ib_device *ibdev, int port, int *slave,
 							     struct ib_mad *mad)
 {
 	u32 pv_cm_id;
 	struct id_map_entry *id;

 	if (mad->mad_hdr.attr_id == CM_REQ_ATTR_ID) {
 		union ib_gid gid;

 		gid = gid_from_req_msg(ibdev, mad);
 		*slave = mlx4_ib_find_real_gid(ibdev, port, gid.global.interface_id);
 		if (*slave < 0) {
 			mlx4_ib_warn(ibdev, "failed matching slave_id by gid (0x%llx)\n",
 					gid.global.interface_id);
 			return -ENOENT;
 		}
 		return 0;
 	}

 	pv_cm_id = get_remote_comm_id(mad);
 	id = id_map_get(ibdev, (int *)&pv_cm_id, -1, -1);

 	if (!id) {
 		pr_debug("Couldn't find an entry for pv_cm_id 0x%x\n", pv_cm_id);
 		return -ENOENT;
 	}

 	*slave = id->slave_id;
 	set_remote_comm_id(mad, id->sl_cm_id);

 	if (mad->mad_hdr.attr_id == CM_DREQ_ATTR_ID)
 		schedule_delayed(ibdev, id);
 	else if (mad->mad_hdr.attr_id == CM_REJ_ATTR_ID ||
 			mad->mad_hdr.attr_id == CM_DREP_ATTR_ID) {
 		id_map_find_del(ibdev, (int) pv_cm_id);
 	}

 	return 0;
 }

 void mlx4_ib_cm_paravirt_init(struct mlx4_ib_dev *dev)
 {
 	spin_lock_init(&dev->sriov.id_map_lock);
 	INIT_LIST_HEAD(&dev->sriov.cm_list);
 	dev->sriov.sl_id_map = RB_ROOT;
 	idr_init(&dev->sriov.pv_id_table);
 	idr_pre_get(&dev->sriov.pv_id_table, GFP_KERNEL);
 }

 /* slave = -1 ==> all slaves */
 /* TBD -- call paravirt clean for single slave.  Need for slave RESET event */
 void mlx4_ib_cm_paravirt_clean(struct mlx4_ib_dev *dev, int slave)
 {
 	struct mlx4_ib_sriov *sriov = &dev->sriov;
 	struct rb_root *sl_id_map = &sriov->sl_id_map;
 	struct list_head lh;
 	struct rb_node *nd;
 	int need_flush = 1;
 	struct id_map_entry *map, *tmp_map;
 	/* cancel all delayed work queue entries */
 	INIT_LIST_HEAD(&lh);
 	spin_lock(&sriov->id_map_lock);
 	list_for_each_entry_safe(map, tmp_map, &dev->sriov.cm_list, list) {
 		if (slave < 0 || slave == map->slave_id) {
 			if (map->scheduled_delete)
 				need_flush &= !!cancel_delayed_work(&map->timeout);
 		}
 	}

 	spin_unlock(&sriov->id_map_lock);

 	if (!need_flush)
 		flush_scheduled_work(); /* make sure all timers were flushed */

 	/* now, remove all leftover entries from databases*/
 	spin_lock(&sriov->id_map_lock);
 	if (slave < 0) {
 		while (rb_first(sl_id_map)) {
 			struct id_map_entry *ent =
 				rb_entry(rb_first(sl_id_map),
 					 struct id_map_entry, node);

 			rb_erase(&ent->node, sl_id_map);
 			idr_remove(&sriov->pv_id_table, (int) ent->pv_cm_id);
 		}
 		list_splice_init(&dev->sriov.cm_list, &lh);
 	} else {
 		/* first, move nodes belonging to slave to db remove list */
 		nd = rb_first(sl_id_map);
 		while (nd) {
 			struct id_map_entry *ent =
 				rb_entry(nd, struct id_map_entry, node);
 			nd = rb_next(nd);
 			if (ent->slave_id == slave)
 				list_move_tail(&ent->list, &lh);
 		}
 		/* remove those nodes from databases */
 		list_for_each_entry_safe(map, tmp_map, &lh, list) {
 			rb_erase(&map->node, sl_id_map);
 			idr_remove(&sriov->pv_id_table, (int) map->pv_cm_id);
 		}

 		/* add remaining nodes from cm_list */
 		list_for_each_entry_safe(map, tmp_map, &dev->sriov.cm_list, list) {
 			if (slave == map->slave_id)
 				list_move_tail(&map->list, &lh);
 		}
 	}

 	spin_unlock(&sriov->id_map_lock);

 	/* free any map entries left behind due to cancel_delayed_work above */
 	list_for_each_entry_safe(map, tmp_map, &lh, list) {
 		list_del(&map->list);
 		kfree(map);
 	}
 }
	/*
	* Copyright (c) 2012 Mellanox Technologies. 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 <rdma/ib_mad.h>

	#include <linux/mlx4/cmd.h>
	#include <linux/rbtree.h>
	#include <linux/idr.h>
	#include <rdma/ib_cm.h>

	#include "mlx4_ib.h"

	#define CM_CLEANUP_CACHE_TIMEOUT (5 * HZ)

	struct id_map_entry {
	struct rb_node node;

	u32 sl_cm_id;
	u32 pv_cm_id;
	int slave_id;
	int scheduled_delete;
	struct mlx4_ib_dev *dev;

	struct list_head list;
	struct delayed_work timeout;
	};

	struct cm_generic_msg {
	struct ib_mad_hdr hdr;

	__be32 local_comm_id;
	__be32 remote_comm_id;
	};

	struct cm_req_msg {
	unsigned char unused[0x60];
	union ib_gid primary_path_sgid;
	};


	static void set_local_comm_id(struct ib_mad *mad, u32 cm_id)
	{
	struct cm_generic_msg msg = (struct cm_generic_msg )mad;
	msg->local_comm_id = cpu_to_be32(cm_id);
	}

	static u32 get_local_comm_id(struct ib_mad *mad)
	{
	struct cm_generic_msg msg = (struct cm_generic_msg )mad;

	return be32_to_cpu(msg->local_comm_id);
	}

	static void set_remote_comm_id(struct ib_mad *mad, u32 cm_id)
	{
	struct cm_generic_msg msg = (struct cm_generic_msg )mad;
	msg->remote_comm_id = cpu_to_be32(cm_id);
	}

	static u32 get_remote_comm_id(struct ib_mad *mad)
	{
	struct cm_generic_msg msg = (struct cm_generic_msg )mad;

	return be32_to_cpu(msg->remote_comm_id);
	}

	static union ib_gid gid_from_req_msg(struct ib_device ibdev, struct ib_mad mad)
	{
	struct cm_req_msg msg = (struct cm_req_msg )mad;

	return msg->primary_path_sgid;
	}

	/* Lock should be taken before called */
	static struct id_map_entry *
	id_map_find_by_sl_id(struct ib_device *ibdev, u32 slave_id, u32 sl_cm_id)
	{
	struct rb_root *sl_id_map = &to_mdev(ibdev)->sriov.sl_id_map;
	struct rb_node *node = sl_id_map->rb_node;

	while (node) {
	struct id_map_entry *id_map_entry =
	rb_entry(node, struct id_map_entry, node);

	if (id_map_entry->sl_cm_id > sl_cm_id)
	node = node->rb_left;
	else if (id_map_entry->sl_cm_id < sl_cm_id)
	node = node->rb_right;
	else if (id_map_entry->slave_id > slave_id)
	node = node->rb_left;
	else if (id_map_entry->slave_id < slave_id)
	node = node->rb_right;
	else
	return id_map_entry;
	}
	return NULL;
	}

	static void id_map_ent_timeout(struct work_struct *work)
	{
	struct delayed_work *delay = to_delayed_work(work);
	struct id_map_entry *ent = container_of(delay, struct id_map_entry, timeout);
	struct id_map_entry db_ent, found_ent;
	struct mlx4_ib_dev *dev = ent->dev;
	struct mlx4_ib_sriov *sriov = &dev->sriov;
	struct rb_root *sl_id_map = &sriov->sl_id_map;
	int pv_id = (int) ent->pv_cm_id;

	spin_lock(&sriov->id_map_lock);
	db_ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, pv_id);
	if (!db_ent)
	goto out;
	found_ent = id_map_find_by_sl_id(&dev->ib_dev, ent->slave_id, ent->sl_cm_id);
	if (found_ent && found_ent == ent)
	rb_erase(&found_ent->node, sl_id_map);
	idr_remove(&sriov->pv_id_table, pv_id);

	out:
	list_del(&ent->list);
	spin_unlock(&sriov->id_map_lock);
	kfree(ent);
	}

	static void id_map_find_del(struct ib_device *ibdev, int pv_cm_id)
	{
	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
	struct rb_root *sl_id_map = &sriov->sl_id_map;
	struct id_map_entry ent, found_ent;

	spin_lock(&sriov->id_map_lock);
	ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, pv_cm_id);
	if (!ent)
	goto out;
	found_ent = id_map_find_by_sl_id(ibdev, ent->slave_id, ent->sl_cm_id);
	if (found_ent && found_ent == ent)
	rb_erase(&found_ent->node, sl_id_map);
	idr_remove(&sriov->pv_id_table, pv_cm_id);
	out:
	spin_unlock(&sriov->id_map_lock);
	}

	static void sl_id_map_add(struct ib_device ibdev, struct id_map_entry new)
	{
	struct rb_root *sl_id_map = &to_mdev(ibdev)->sriov.sl_id_map;
	struct rb_node *link = &sl_id_map->rb_node, parent = NULL;
	struct id_map_entry *ent;
	int slave_id = new->slave_id;
	int sl_cm_id = new->sl_cm_id;

	ent = id_map_find_by_sl_id(ibdev, slave_id, sl_cm_id);
	if (ent) {
	pr_debug("overriding existing sl_id_map entry (cm_id = %x)\n",
	sl_cm_id);

	rb_replace_node(&ent->node, &new->node, sl_id_map);
	return;
	}

	/* Go to the bottom of the tree */
	while (*link) {
	parent = *link;
	ent = rb_entry(parent, struct id_map_entry, node);

	if (ent->sl_cm_id > sl_cm_id \|\| (ent->sl_cm_id == sl_cm_id && ent->slave_id > slave_id))
	link = &(*link)->rb_left;
	else
	link = &(*link)->rb_right;
	}

	rb_link_node(&new->node, parent, link);
	rb_insert_color(&new->node, sl_id_map);
	}

	static struct id_map_entry *
	id_map_alloc(struct ib_device *ibdev, int slave_id, u32 sl_cm_id)
	{
	int ret, id;
	static int next_id;
	struct id_map_entry *ent;
	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;

	ent = kmalloc(sizeof (struct id_map_entry), GFP_KERNEL);
	if (!ent) {
	mlx4_ib_warn(ibdev, "Couldn't allocate id cache entry - out of memory\n");
	return ERR_PTR(-ENOMEM);
	}

	ent->sl_cm_id = sl_cm_id;
	ent->slave_id = slave_id;
	ent->scheduled_delete = 0;
	ent->dev = to_mdev(ibdev);
	INIT_DELAYED_WORK(&ent->timeout, id_map_ent_timeout);

	do {
	spin_lock(&to_mdev(ibdev)->sriov.id_map_lock);
	ret = idr_get_new_above(&sriov->pv_id_table, ent,
	next_id, &id);
	if (!ret) {
	next_id = ((unsigned) id + 1) & MAX_IDR_MASK;
	ent->pv_cm_id = (u32)id;
	sl_id_map_add(ibdev, ent);
	}

	spin_unlock(&sriov->id_map_lock);
	} while (ret == -EAGAIN && idr_pre_get(&sriov->pv_id_table, GFP_KERNEL));
	/the function idr_get_new_above can return -ENOSPC, so don't insert in that case./
	if (!ret) {
	spin_lock(&sriov->id_map_lock);
	list_add_tail(&ent->list, &sriov->cm_list);
	spin_unlock(&sriov->id_map_lock);
	return ent;
	}
	/error flow/
	kfree(ent);
	mlx4_ib_warn(ibdev, "No more space in the idr (err:0x%x)\n", ret);
	return ERR_PTR(-ENOMEM);
	}

	static struct id_map_entry *
	id_map_get(struct ib_device ibdev, int pv_cm_id, int sl_cm_id, int slave_id)
	{
	struct id_map_entry *ent;
	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;

	spin_lock(&sriov->id_map_lock);
	if (*pv_cm_id == -1) {
	ent = id_map_find_by_sl_id(ibdev, sl_cm_id, slave_id);
	if (ent)
	*pv_cm_id = (int) ent->pv_cm_id;
	} else
	ent = (struct id_map_entry )idr_find(&sriov->pv_id_table, pv_cm_id);
	spin_unlock(&sriov->id_map_lock);

	return ent;
	}

	static void schedule_delayed(struct ib_device ibdev, struct id_map_entry id)
	{
	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
	unsigned long flags;

	spin_lock(&sriov->id_map_lock);
	spin_lock_irqsave(&sriov->going_down_lock, flags);
	/make sure that there is no schedule inside the scheduled work./
	if (!sriov->is_going_down) {
	id->scheduled_delete = 1;
	schedule_delayed_work(&id->timeout, CM_CLEANUP_CACHE_TIMEOUT);
	}
	spin_unlock_irqrestore(&sriov->going_down_lock, flags);
	spin_unlock(&sriov->id_map_lock);
	}

	int mlx4_ib_multiplex_cm_handler(struct ib_device *ibdev, int port, int slave_id,
	struct ib_mad *mad)
	{
	struct id_map_entry *id;
	u32 sl_cm_id;
	int pv_cm_id = -1;

	sl_cm_id = get_local_comm_id(mad);

	if (mad->mad_hdr.attr_id == CM_REQ_ATTR_ID \|\|
	mad->mad_hdr.attr_id == CM_REP_ATTR_ID) {
	id = id_map_alloc(ibdev, slave_id, sl_cm_id);
	if (IS_ERR(id)) {
	mlx4_ib_warn(ibdev, "%s: id{slave: %d, sl_cm_id: 0x%x} Failed to id_map_alloc\n",
	__func__, slave_id, sl_cm_id);
	return PTR_ERR(id);
	}
	} else if (mad->mad_hdr.attr_id == CM_REJ_ATTR_ID) {
	return 0;
	} else {
	id = id_map_get(ibdev, &pv_cm_id, slave_id, sl_cm_id);
	}

	if (!id) {
	pr_debug("id{slave: %d, sl_cm_id: 0x%x} is NULL!\n",
	slave_id, sl_cm_id);
	return -EINVAL;
	}

	set_local_comm_id(mad, id->pv_cm_id);

	if (mad->mad_hdr.attr_id == CM_DREQ_ATTR_ID)
	schedule_delayed(ibdev, id);
	else if (mad->mad_hdr.attr_id == CM_DREP_ATTR_ID)
	id_map_find_del(ibdev, pv_cm_id);

	return 0;
	}

	int mlx4_ib_demux_cm_handler(struct ib_device ibdev, int port, int slave,
	struct ib_mad *mad)
	{
	u32 pv_cm_id;
	struct id_map_entry *id;

	if (mad->mad_hdr.attr_id == CM_REQ_ATTR_ID) {
	union ib_gid gid;

	gid = gid_from_req_msg(ibdev, mad);
	*slave = mlx4_ib_find_real_gid(ibdev, port, gid.global.interface_id);
	if (*slave < 0) {
	mlx4_ib_warn(ibdev, "failed matching slave_id by gid (0x%llx)\n",
	gid.global.interface_id);
	return -ENOENT;
	}
	return 0;
	}

	pv_cm_id = get_remote_comm_id(mad);
	id = id_map_get(ibdev, (int *)&pv_cm_id, -1, -1);

	if (!id) {
	pr_debug("Couldn't find an entry for pv_cm_id 0x%x\n", pv_cm_id);
	return -ENOENT;
	}

	*slave = id->slave_id;
	set_remote_comm_id(mad, id->sl_cm_id);

	if (mad->mad_hdr.attr_id == CM_DREQ_ATTR_ID)
	schedule_delayed(ibdev, id);
	else if (mad->mad_hdr.attr_id == CM_REJ_ATTR_ID \|\|
	mad->mad_hdr.attr_id == CM_DREP_ATTR_ID) {
	id_map_find_del(ibdev, (int) pv_cm_id);
	}

	return 0;
	}

	void mlx4_ib_cm_paravirt_init(struct mlx4_ib_dev *dev)
	{
	spin_lock_init(&dev->sriov.id_map_lock);
	INIT_LIST_HEAD(&dev->sriov.cm_list);
	dev->sriov.sl_id_map = RB_ROOT;
	idr_init(&dev->sriov.pv_id_table);
	idr_pre_get(&dev->sriov.pv_id_table, GFP_KERNEL);
	}

	/* slave = -1 ==> all slaves */
	/* TBD -- call paravirt clean for single slave. Need for slave RESET event */
	void mlx4_ib_cm_paravirt_clean(struct mlx4_ib_dev *dev, int slave)
	{
	struct mlx4_ib_sriov *sriov = &dev->sriov;
	struct rb_root *sl_id_map = &sriov->sl_id_map;
	struct list_head lh;
	struct rb_node *nd;
	int need_flush = 1;
	struct id_map_entry map, tmp_map;
	/* cancel all delayed work queue entries */
	INIT_LIST_HEAD(&lh);
	spin_lock(&sriov->id_map_lock);
	list_for_each_entry_safe(map, tmp_map, &dev->sriov.cm_list, list) {
	if (slave < 0 \|\| slave == map->slave_id) {
	if (map->scheduled_delete)
	need_flush &= !!cancel_delayed_work(&map->timeout);
	}
	}

	spin_unlock(&sriov->id_map_lock);

	if (!need_flush)
	flush_scheduled_work(); /* make sure all timers were flushed */

	/* now, remove all leftover entries from databases*/
	spin_lock(&sriov->id_map_lock);
	if (slave < 0) {
	while (rb_first(sl_id_map)) {
	struct id_map_entry *ent =
	rb_entry(rb_first(sl_id_map),
	struct id_map_entry, node);

	rb_erase(&ent->node, sl_id_map);
	idr_remove(&sriov->pv_id_table, (int) ent->pv_cm_id);
	}
	list_splice_init(&dev->sriov.cm_list, &lh);
	} else {
	/* first, move nodes belonging to slave to db remove list */
	nd = rb_first(sl_id_map);
	while (nd) {
	struct id_map_entry *ent =
	rb_entry(nd, struct id_map_entry, node);
	nd = rb_next(nd);
	if (ent->slave_id == slave)
	list_move_tail(&ent->list, &lh);
	}
	/* remove those nodes from databases */
	list_for_each_entry_safe(map, tmp_map, &lh, list) {
	rb_erase(&map->node, sl_id_map);
	idr_remove(&sriov->pv_id_table, (int) map->pv_cm_id);
	}

	/* add remaining nodes from cm_list */
	list_for_each_entry_safe(map, tmp_map, &dev->sriov.cm_list, list) {
	if (slave == map->slave_id)
	list_move_tail(&map->list, &lh);
	}
	}

	spin_unlock(&sriov->id_map_lock);

	/* free any map entries left behind due to cancel_delayed_work above */
	list_for_each_entry_safe(map, tmp_map, &lh, list) {
	list_del(&map->list);
	kfree(map);
	}
	}