text: /*
   * 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;
  	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);
  
  	idr_preload(GFP_KERNEL);
  	spin_lock(&to_mdev(ibdev)->sriov.id_map_lock);
  
  	ret = idr_alloc_cyclic(&sriov->pv_id_table, ent, 0, 0, GFP_NOWAIT);
  	if (ret >= 0) {
  		ent->pv_cm_id = (u32)ret;
  		sl_id_map_add(ibdev, ent);
  		list_add_tail(&ent->list, &sriov->cm_list);
  	}
  
  	spin_unlock(&sriov->id_map_lock);
  	idr_preload_end();
  
  	if (ret >= 0)
  		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);
  }
  
  /* 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);
  	}
  }
  