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cm.c

/*
 * Copyright (c) 2004, 2005 Intel Corporation.  All rights reserved.
 * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
 * Copyright (c) 2004, 2005 Voltaire Corporation.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, 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.
 *
 * $Id: cm.c 4311 2005-12-05 18:42:01Z sean.hefty $
 */

#include <linux/completion.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/rbtree.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>

#include <rdma/ib_cache.h>
#include <rdma/ib_cm.h>
#include "cm_msgs.h"

MODULE_AUTHOR("Sean Hefty");
MODULE_DESCRIPTION("InfiniBand CM");
MODULE_LICENSE("Dual BSD/GPL");

static void cm_add_one(struct ib_device *device);
static void cm_remove_one(struct ib_device *device);

static struct ib_client cm_client = {
      .name   = "cm",
      .add    = cm_add_one,
      .remove = cm_remove_one
};

static struct ib_cm {
      spinlock_t lock;
      struct list_head device_list;
      rwlock_t device_lock;
      struct rb_root listen_service_table;
      u64 listen_service_id;
      /* struct rb_root peer_service_table; todo: fix peer to peer */
      struct rb_root remote_qp_table;
      struct rb_root remote_id_table;
      struct rb_root remote_sidr_table;
      struct idr local_id_table;
      struct workqueue_struct *wq;
} cm;

struct cm_port {
      struct cm_device *cm_dev;
      struct ib_mad_agent *mad_agent;
      u8 port_num;
};

struct cm_device {
      struct list_head list;
      struct ib_device *device;
      __be64 ca_guid;
      struct cm_port port[0];
};

struct cm_av {
      struct cm_port *port;
      union ib_gid dgid;
      struct ib_ah_attr ah_attr;
      u16 pkey_index;
      u8 packet_life_time;
};

struct cm_work {
      struct work_struct work;
      struct list_head list;
      struct cm_port *port;
      struct ib_mad_recv_wc *mad_recv_wc; /* Received MADs */
      __be32 local_id;              /* Established / timewait */
      __be32 remote_id;
      struct ib_cm_event cm_event;
      struct ib_sa_path_rec path[0];
};

struct cm_timewait_info {
      struct cm_work work;                /* Must be first. */
      struct rb_node remote_qp_node;
      struct rb_node remote_id_node;
      __be64 remote_ca_guid;
      __be32 remote_qpn;
      u8 inserted_remote_qp;
      u8 inserted_remote_id;
};

struct cm_id_private {
      struct ib_cm_id   id;

      struct rb_node service_node;
      struct rb_node sidr_id_node;
      spinlock_t lock;  /* Do not acquire inside cm.lock */
      struct completion comp;
      atomic_t refcount;

      struct ib_mad_send_buf *msg;
      struct cm_timewait_info *timewait_info;
      /* todo: use alternate port on send failure */
      struct cm_av av;
      struct cm_av alt_av;
      struct ib_cm_compare_data *compare_data;

      void *private_data;
      __be64 tid;
      __be32 local_qpn;
      __be32 remote_qpn;
      enum ib_qp_type qp_type;
      __be32 sq_psn;
      __be32 rq_psn;
      int timeout_ms;
      enum ib_mtu path_mtu;
      u8 private_data_len;
      u8 max_cm_retries;
      u8 peer_to_peer;
      u8 responder_resources;
      u8 initiator_depth;
      u8 local_ack_timeout;
      u8 retry_count;
      u8 rnr_retry_count;
      u8 service_timeout;

      struct list_head work_list;
      atomic_t work_count;
};

static void cm_work_handler(void *data);

static inline void cm_deref_id(struct cm_id_private *cm_id_priv)
{
      if (atomic_dec_and_test(&cm_id_priv->refcount))
            complete(&cm_id_priv->comp);
}

static int cm_alloc_msg(struct cm_id_private *cm_id_priv,
                  struct ib_mad_send_buf **msg)
{
      struct ib_mad_agent *mad_agent;
      struct ib_mad_send_buf *m;
      struct ib_ah *ah;

      mad_agent = cm_id_priv->av.port->mad_agent;
      ah = ib_create_ah(mad_agent->qp->pd, &cm_id_priv->av.ah_attr);
      if (IS_ERR(ah))
            return PTR_ERR(ah);

      m = ib_create_send_mad(mad_agent, cm_id_priv->id.remote_cm_qpn, 
                         cm_id_priv->av.pkey_index,
                         0, IB_MGMT_MAD_HDR, IB_MGMT_MAD_DATA,
                         GFP_ATOMIC);
      if (IS_ERR(m)) {
            ib_destroy_ah(ah);
            return PTR_ERR(m);
      }

      /* Timeout set by caller if response is expected. */
      m->ah = ah;
      m->retries = cm_id_priv->max_cm_retries;

      atomic_inc(&cm_id_priv->refcount);
      m->context[0] = cm_id_priv;
      *msg = m;
      return 0;
}

static int cm_alloc_response_msg(struct cm_port *port,
                         struct ib_mad_recv_wc *mad_recv_wc,
                         struct ib_mad_send_buf **msg)
{
      struct ib_mad_send_buf *m;
      struct ib_ah *ah;

      ah = ib_create_ah_from_wc(port->mad_agent->qp->pd, mad_recv_wc->wc,
                          mad_recv_wc->recv_buf.grh, port->port_num);
      if (IS_ERR(ah))
            return PTR_ERR(ah);

      m = ib_create_send_mad(port->mad_agent, 1, mad_recv_wc->wc->pkey_index,
                         0, IB_MGMT_MAD_HDR, IB_MGMT_MAD_DATA,
                         GFP_ATOMIC);
      if (IS_ERR(m)) {
            ib_destroy_ah(ah);
            return PTR_ERR(m);
      }
      m->ah = ah;
      *msg = m;
      return 0;
}

static void cm_free_msg(struct ib_mad_send_buf *msg)
{
      ib_destroy_ah(msg->ah);
      if (msg->context[0])
            cm_deref_id(msg->context[0]);
      ib_free_send_mad(msg);
}

static void * cm_copy_private_data(const void *private_data,
                           u8 private_data_len)
{
      void *data;

      if (!private_data || !private_data_len)
            return NULL;

      data = kmalloc(private_data_len, GFP_KERNEL);
      if (!data)
            return ERR_PTR(-ENOMEM);

      memcpy(data, private_data, private_data_len);
      return data;
}

static void cm_set_private_data(struct cm_id_private *cm_id_priv,
                         void *private_data, u8 private_data_len)
{
      if (cm_id_priv->private_data && cm_id_priv->private_data_len)
            kfree(cm_id_priv->private_data);

      cm_id_priv->private_data = private_data;
      cm_id_priv->private_data_len = private_data_len;
}

static void cm_init_av_for_response(struct cm_port *port, struct ib_wc *wc,
                            struct ib_grh *grh, struct cm_av *av)
{
      av->port = port;
      av->pkey_index = wc->pkey_index;
      ib_init_ah_from_wc(port->cm_dev->device, port->port_num, wc,
                     grh, &av->ah_attr);
}

static int cm_init_av_by_path(struct ib_sa_path_rec *path, struct cm_av *av)
{
      struct cm_device *cm_dev;
      struct cm_port *port = NULL;
      unsigned long flags;
      int ret;
      u8 p;

      read_lock_irqsave(&cm.device_lock, flags);
      list_for_each_entry(cm_dev, &cm.device_list, list) {
            if (!ib_find_cached_gid(cm_dev->device, &path->sgid,
                              &p, NULL)) {
                  port = &cm_dev->port[p-1];
                  break;
            }
      }
      read_unlock_irqrestore(&cm.device_lock, flags);

      if (!port)
            return -EINVAL;

      ret = ib_find_cached_pkey(cm_dev->device, port->port_num,
                          be16_to_cpu(path->pkey), &av->pkey_index);
      if (ret)
            return ret;

      av->port = port;
      ib_init_ah_from_path(cm_dev->device, port->port_num, path,
                       &av->ah_attr);
      av->packet_life_time = path->packet_life_time;
      return 0;
}

static int cm_alloc_id(struct cm_id_private *cm_id_priv)
{
      unsigned long flags;
      int ret;
      static int next_id;

      do {
            spin_lock_irqsave(&cm.lock, flags);
            ret = idr_get_new_above(&cm.local_id_table, cm_id_priv, next_id++,
                              (__force int *) &cm_id_priv->id.local_id);
            spin_unlock_irqrestore(&cm.lock, flags);
      } while( (ret == -EAGAIN) && idr_pre_get(&cm.local_id_table, GFP_KERNEL) );
      return ret;
}

static void cm_free_id(__be32 local_id)
{
      unsigned long flags;

      spin_lock_irqsave(&cm.lock, flags);
      idr_remove(&cm.local_id_table, (__force int) local_id);
      spin_unlock_irqrestore(&cm.lock, flags);
}

static struct cm_id_private * cm_get_id(__be32 local_id, __be32 remote_id)
{
      struct cm_id_private *cm_id_priv;

      cm_id_priv = idr_find(&cm.local_id_table, (__force int) local_id);
      if (cm_id_priv) {
            if (cm_id_priv->id.remote_id == remote_id)
                  atomic_inc(&cm_id_priv->refcount);
            else
                  cm_id_priv = NULL;
      }

      return cm_id_priv;
}

static struct cm_id_private * cm_acquire_id(__be32 local_id, __be32 remote_id)
{
      struct cm_id_private *cm_id_priv;
      unsigned long flags;

      spin_lock_irqsave(&cm.lock, flags);
      cm_id_priv = cm_get_id(local_id, remote_id);
      spin_unlock_irqrestore(&cm.lock, flags);

      return cm_id_priv;
}

static void cm_mask_copy(u8 *dst, u8 *src, u8 *mask)
{
      int i;

      for (i = 0; i < IB_CM_COMPARE_SIZE / sizeof(unsigned long); i++)
            ((unsigned long *) dst)[i] = ((unsigned long *) src)[i] &
                                   ((unsigned long *) mask)[i];
}

static int cm_compare_data(struct ib_cm_compare_data *src_data,
                     struct ib_cm_compare_data *dst_data)
{
      u8 src[IB_CM_COMPARE_SIZE];
      u8 dst[IB_CM_COMPARE_SIZE];

      if (!src_data || !dst_data)
            return 0;

      cm_mask_copy(src, src_data->data, dst_data->mask);
      cm_mask_copy(dst, dst_data->data, src_data->mask);
      return memcmp(src, dst, IB_CM_COMPARE_SIZE);
}

static int cm_compare_private_data(u8 *private_data,
                           struct ib_cm_compare_data *dst_data)
{
      u8 src[IB_CM_COMPARE_SIZE];

      if (!dst_data)
            return 0;

      cm_mask_copy(src, private_data, dst_data->mask);
      return memcmp(src, dst_data->data, IB_CM_COMPARE_SIZE);
}

static struct cm_id_private * cm_insert_listen(struct cm_id_private *cm_id_priv)
{
      struct rb_node **link = &cm.listen_service_table.rb_node;
      struct rb_node *parent = NULL;
      struct cm_id_private *cur_cm_id_priv;
      __be64 service_id = cm_id_priv->id.service_id;
      __be64 service_mask = cm_id_priv->id.service_mask;
      int data_cmp;

      while (*link) {
            parent = *link;
            cur_cm_id_priv = rb_entry(parent, struct cm_id_private,
                                service_node);
            data_cmp = cm_compare_data(cm_id_priv->compare_data,
                                 cur_cm_id_priv->compare_data);
            if ((cur_cm_id_priv->id.service_mask & service_id) ==
                (service_mask & cur_cm_id_priv->id.service_id) &&
                (cm_id_priv->id.device == cur_cm_id_priv->id.device) &&
                !data_cmp)
                  return cur_cm_id_priv;

            if (cm_id_priv->id.device < cur_cm_id_priv->id.device)
                  link = &(*link)->rb_left;
            else if (cm_id_priv->id.device > cur_cm_id_priv->id.device)
                  link = &(*link)->rb_right;
            else if (service_id < cur_cm_id_priv->id.service_id)
                  link = &(*link)->rb_left;
            else if (service_id > cur_cm_id_priv->id.service_id)
                  link = &(*link)->rb_right;
            else if (data_cmp < 0)
                  link = &(*link)->rb_left;
            else
                  link = &(*link)->rb_right;
      }
      rb_link_node(&cm_id_priv->service_node, parent, link);
      rb_insert_color(&cm_id_priv->service_node, &cm.listen_service_table);
      return NULL;
}

static struct cm_id_private * cm_find_listen(struct ib_device *device,
                                   __be64 service_id,
                                   u8 *private_data)
{
      struct rb_node *node = cm.listen_service_table.rb_node;
      struct cm_id_private *cm_id_priv;
      int data_cmp;

      while (node) {
            cm_id_priv = rb_entry(node, struct cm_id_private, service_node);
            data_cmp = cm_compare_private_data(private_data,
                                       cm_id_priv->compare_data);
            if ((cm_id_priv->id.service_mask & service_id) ==
                 cm_id_priv->id.service_id &&
                (cm_id_priv->id.device == device) && !data_cmp)
                  return cm_id_priv;

            if (device < cm_id_priv->id.device)
                  node = node->rb_left;
            else if (device > cm_id_priv->id.device)
                  node = node->rb_right;
            else if (service_id < cm_id_priv->id.service_id)
                  node = node->rb_left;
            else if (service_id > cm_id_priv->id.service_id)
                  node = node->rb_right;
            else if (data_cmp < 0)
                  node = node->rb_left;
            else
                  node = node->rb_right;
      }
      return NULL;
}

static struct cm_timewait_info * cm_insert_remote_id(struct cm_timewait_info
                                         *timewait_info)
{
      struct rb_node **link = &cm.remote_id_table.rb_node;
      struct rb_node *parent = NULL;
      struct cm_timewait_info *cur_timewait_info;
      __be64 remote_ca_guid = timewait_info->remote_ca_guid;
      __be32 remote_id = timewait_info->work.remote_id;

      while (*link) {
            parent = *link;
            cur_timewait_info = rb_entry(parent, struct cm_timewait_info,
                                   remote_id_node);
            if (remote_id < cur_timewait_info->work.remote_id)
                  link = &(*link)->rb_left;
            else if (remote_id > cur_timewait_info->work.remote_id)
                  link = &(*link)->rb_right;
            else if (remote_ca_guid < cur_timewait_info->remote_ca_guid)
                  link = &(*link)->rb_left;
            else if (remote_ca_guid > cur_timewait_info->remote_ca_guid)
                  link = &(*link)->rb_right;
            else
                  return cur_timewait_info;
      }
      timewait_info->inserted_remote_id = 1;
      rb_link_node(&timewait_info->remote_id_node, parent, link);
      rb_insert_color(&timewait_info->remote_id_node, &cm.remote_id_table);
      return NULL;
}

static struct cm_timewait_info * cm_find_remote_id(__be64 remote_ca_guid,
                                       __be32 remote_id)
{
      struct rb_node *node = cm.remote_id_table.rb_node;
      struct cm_timewait_info *timewait_info;

      while (node) {
            timewait_info = rb_entry(node, struct cm_timewait_info,
                               remote_id_node);
            if (remote_id < timewait_info->work.remote_id)
                  node = node->rb_left;
            else if (remote_id > timewait_info->work.remote_id)
                  node = node->rb_right;
            else if (remote_ca_guid < timewait_info->remote_ca_guid)
                  node = node->rb_left;
            else if (remote_ca_guid > timewait_info->remote_ca_guid)
                  node = node->rb_right;
            else
                  return timewait_info;
      }
      return NULL;
}

static struct cm_timewait_info * cm_insert_remote_qpn(struct cm_timewait_info
                                          *timewait_info)
{
      struct rb_node **link = &cm.remote_qp_table.rb_node;
      struct rb_node *parent = NULL;
      struct cm_timewait_info *cur_timewait_info;
      __be64 remote_ca_guid = timewait_info->remote_ca_guid;
      __be32 remote_qpn = timewait_info->remote_qpn;

      while (*link) {
            parent = *link;
            cur_timewait_info = rb_entry(parent, struct cm_timewait_info,
                                   remote_qp_node);
            if (remote_qpn < cur_timewait_info->remote_qpn)
                  link = &(*link)->rb_left;
            else if (remote_qpn > cur_timewait_info->remote_qpn)
                  link = &(*link)->rb_right;
            else if (remote_ca_guid < cur_timewait_info->remote_ca_guid)
                  link = &(*link)->rb_left;
            else if (remote_ca_guid > cur_timewait_info->remote_ca_guid)
                  link = &(*link)->rb_right;
            else
                  return cur_timewait_info;
      }
      timewait_info->inserted_remote_qp = 1;
      rb_link_node(&timewait_info->remote_qp_node, parent, link);
      rb_insert_color(&timewait_info->remote_qp_node, &cm.remote_qp_table);
      return NULL;
}

static struct cm_id_private * cm_insert_remote_sidr(struct cm_id_private
                                        *cm_id_priv)
{
      struct rb_node **link = &cm.remote_sidr_table.rb_node;
      struct rb_node *parent = NULL;
      struct cm_id_private *cur_cm_id_priv;
      union ib_gid *port_gid = &cm_id_priv->av.dgid;
      __be32 remote_id = cm_id_priv->id.remote_id;

      while (*link) {
            parent = *link;
            cur_cm_id_priv = rb_entry(parent, struct cm_id_private,
                                sidr_id_node);
            if (remote_id < cur_cm_id_priv->id.remote_id)
                  link = &(*link)->rb_left;
            else if (remote_id > cur_cm_id_priv->id.remote_id)
                  link = &(*link)->rb_right;
            else {
                  int cmp;
                  cmp = memcmp(port_gid, &cur_cm_id_priv->av.dgid,
                             sizeof *port_gid);
                  if (cmp < 0)
                        link = &(*link)->rb_left;
                  else if (cmp > 0)
                        link = &(*link)->rb_right;
                  else
                        return cur_cm_id_priv;
            }
      }
      rb_link_node(&cm_id_priv->sidr_id_node, parent, link);
      rb_insert_color(&cm_id_priv->sidr_id_node, &cm.remote_sidr_table);
      return NULL;
}

static void cm_reject_sidr_req(struct cm_id_private *cm_id_priv,
                         enum ib_cm_sidr_status status)
{
      struct ib_cm_sidr_rep_param param;

      memset(&param, 0, sizeof param);
      param.status = status;
      ib_send_cm_sidr_rep(&cm_id_priv->id, &param);
}

struct ib_cm_id *ib_create_cm_id(struct ib_device *device,
                         ib_cm_handler cm_handler,
                         void *context)
{
      struct cm_id_private *cm_id_priv;
      int ret;

      cm_id_priv = kzalloc(sizeof *cm_id_priv, GFP_KERNEL);
      if (!cm_id_priv)
            return ERR_PTR(-ENOMEM);

      cm_id_priv->id.state = IB_CM_IDLE;
      cm_id_priv->id.device = device;
      cm_id_priv->id.cm_handler = cm_handler;
      cm_id_priv->id.context = context;
      cm_id_priv->id.remote_cm_qpn = 1;
      ret = cm_alloc_id(cm_id_priv);
      if (ret)
            goto error;

      spin_lock_init(&cm_id_priv->lock);
      init_completion(&cm_id_priv->comp);
      INIT_LIST_HEAD(&cm_id_priv->work_list);
      atomic_set(&cm_id_priv->work_count, -1);
      atomic_set(&cm_id_priv->refcount, 1);
      return &cm_id_priv->id;

error:
      kfree(cm_id_priv);
      return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL(ib_create_cm_id);

static struct cm_work * cm_dequeue_work(struct cm_id_private *cm_id_priv)
{
      struct cm_work *work;

      if (list_empty(&cm_id_priv->work_list))
            return NULL;

      work = list_entry(cm_id_priv->work_list.next, struct cm_work, list);
      list_del(&work->list);
      return work;
}

static void cm_free_work(struct cm_work *work)
{
      if (work->mad_recv_wc)
            ib_free_recv_mad(work->mad_recv_wc);
      kfree(work);
}

static inline int cm_convert_to_ms(int iba_time)
{
      /* approximate conversion to ms from 4.096us x 2^iba_time */
      return 1 << max(iba_time - 8, 0);
}

static void cm_cleanup_timewait(struct cm_timewait_info *timewait_info)
{
      unsigned long flags;

      if (!timewait_info->inserted_remote_id &&
          !timewait_info->inserted_remote_qp)
          return;

      spin_lock_irqsave(&cm.lock, flags);
      if (timewait_info->inserted_remote_id) {
            rb_erase(&timewait_info->remote_id_node, &cm.remote_id_table);
            timewait_info->inserted_remote_id = 0;
      }

      if (timewait_info->inserted_remote_qp) {
            rb_erase(&timewait_info->remote_qp_node, &cm.remote_qp_table);
            timewait_info->inserted_remote_qp = 0;
      }
      spin_unlock_irqrestore(&cm.lock, flags);
}

static struct cm_timewait_info * cm_create_timewait_info(__be32 local_id)
{
      struct cm_timewait_info *timewait_info;

      timewait_info = kzalloc(sizeof *timewait_info, GFP_KERNEL);
      if (!timewait_info)
            return ERR_PTR(-ENOMEM);

      timewait_info->work.local_id = local_id;
      INIT_WORK(&timewait_info->work.work, cm_work_handler,
              &timewait_info->work);
      timewait_info->work.cm_event.event = IB_CM_TIMEWAIT_EXIT;
      return timewait_info;
}

static void cm_enter_timewait(struct cm_id_private *cm_id_priv)
{
      int wait_time;

      /*
       * The cm_id could be destroyed by the user before we exit timewait.
       * To protect against this, we search for the cm_id after exiting
       * timewait before notifying the user that we've exited timewait.
       */
      cm_id_priv->id.state = IB_CM_TIMEWAIT;
      wait_time = cm_convert_to_ms(cm_id_priv->local_ack_timeout);
      queue_delayed_work(cm.wq, &cm_id_priv->timewait_info->work.work,
                     msecs_to_jiffies(wait_time));
      cm_id_priv->timewait_info = NULL;
}

static void cm_reset_to_idle(struct cm_id_private *cm_id_priv)
{
      cm_id_priv->id.state = IB_CM_IDLE;
      if (cm_id_priv->timewait_info) {
            cm_cleanup_timewait(cm_id_priv->timewait_info);
            kfree(cm_id_priv->timewait_info);
            cm_id_priv->timewait_info = NULL;
      }
}

static void cm_destroy_id(struct ib_cm_id *cm_id, int err)
{
      struct cm_id_private *cm_id_priv;
      struct cm_work *work;
      unsigned long flags;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
retest:
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id->state) {
      case IB_CM_LISTEN:
            cm_id->state = IB_CM_IDLE;
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            spin_lock_irqsave(&cm.lock, flags);
            rb_erase(&cm_id_priv->service_node, &cm.listen_service_table);
            spin_unlock_irqrestore(&cm.lock, flags);
            break;
      case IB_CM_SIDR_REQ_SENT:
            cm_id->state = IB_CM_IDLE;
            ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            break;
      case IB_CM_SIDR_REQ_RCVD:
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_reject_sidr_req(cm_id_priv, IB_SIDR_REJECT);
            break;
      case IB_CM_REQ_SENT:
            ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            ib_send_cm_rej(cm_id, IB_CM_REJ_TIMEOUT,
                         &cm_id_priv->av.port->cm_dev->ca_guid,
                         sizeof cm_id_priv->av.port->cm_dev->ca_guid,
                         NULL, 0);
            break;
      case IB_CM_REQ_RCVD:
            if (err == -ENOMEM) {
                  /* Do not reject to allow future retries. */
                  cm_reset_to_idle(cm_id_priv);
                  spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            } else {
                  spin_unlock_irqrestore(&cm_id_priv->lock, flags);
                  ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
                               NULL, 0, NULL, 0);
            }
            break;
      case IB_CM_MRA_REQ_RCVD:
      case IB_CM_REP_SENT:
      case IB_CM_MRA_REP_RCVD:
            ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
            /* Fall through */
      case IB_CM_MRA_REQ_SENT:
      case IB_CM_REP_RCVD:
      case IB_CM_MRA_REP_SENT:
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
                         NULL, 0, NULL, 0);
            break;
      case IB_CM_ESTABLISHED:
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            ib_send_cm_dreq(cm_id, NULL, 0);
            goto retest;
      case IB_CM_DREQ_SENT:
            ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
            cm_enter_timewait(cm_id_priv);
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            break;
      case IB_CM_DREQ_RCVD:
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            ib_send_cm_drep(cm_id, NULL, 0);
            break;
      default:
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            break;
      }

      cm_free_id(cm_id->local_id);
      cm_deref_id(cm_id_priv);
      wait_for_completion(&cm_id_priv->comp);
      while ((work = cm_dequeue_work(cm_id_priv)) != NULL)
            cm_free_work(work);
      kfree(cm_id_priv->compare_data);
      kfree(cm_id_priv->private_data);
      kfree(cm_id_priv);
}

void ib_destroy_cm_id(struct ib_cm_id *cm_id)
{
      cm_destroy_id(cm_id, 0);
}
EXPORT_SYMBOL(ib_destroy_cm_id);

int ib_cm_listen(struct ib_cm_id *cm_id, __be64 service_id, __be64 service_mask,
             struct ib_cm_compare_data *compare_data)
{
      struct cm_id_private *cm_id_priv, *cur_cm_id_priv;
      unsigned long flags;
      int ret = 0;

      service_mask = service_mask ? service_mask :
                   __constant_cpu_to_be64(~0ULL);
      service_id &= service_mask;
      if ((service_id & IB_SERVICE_ID_AGN_MASK) == IB_CM_ASSIGN_SERVICE_ID &&
          (service_id != IB_CM_ASSIGN_SERVICE_ID))
            return -EINVAL;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      if (cm_id->state != IB_CM_IDLE)
            return -EINVAL;

      if (compare_data) {
            cm_id_priv->compare_data = kzalloc(sizeof *compare_data,
                                       GFP_KERNEL);
            if (!cm_id_priv->compare_data)
                  return -ENOMEM;
            cm_mask_copy(cm_id_priv->compare_data->data,
                       compare_data->data, compare_data->mask);
            memcpy(cm_id_priv->compare_data->mask, compare_data->mask,
                   IB_CM_COMPARE_SIZE);
      }

      cm_id->state = IB_CM_LISTEN;

      spin_lock_irqsave(&cm.lock, flags);
      if (service_id == IB_CM_ASSIGN_SERVICE_ID) {
            cm_id->service_id = cpu_to_be64(cm.listen_service_id++);
            cm_id->service_mask = __constant_cpu_to_be64(~0ULL);
      } else {
            cm_id->service_id = service_id;
            cm_id->service_mask = service_mask;
      }
      cur_cm_id_priv = cm_insert_listen(cm_id_priv);
      spin_unlock_irqrestore(&cm.lock, flags);

      if (cur_cm_id_priv) {
            cm_id->state = IB_CM_IDLE;
            kfree(cm_id_priv->compare_data);
            cm_id_priv->compare_data = NULL;
            ret = -EBUSY;
      }
      return ret;
}
EXPORT_SYMBOL(ib_cm_listen);

static __be64 cm_form_tid(struct cm_id_private *cm_id_priv,
                    enum cm_msg_sequence msg_seq)
{
      u64 hi_tid, low_tid;

      hi_tid   = ((u64) cm_id_priv->av.port->mad_agent->hi_tid) << 32;
      low_tid  = (u64) ((__force u32)cm_id_priv->id.local_id |
                    (msg_seq << 30));
      return cpu_to_be64(hi_tid | low_tid);
}

static void cm_format_mad_hdr(struct ib_mad_hdr *hdr,
                        __be16 attr_id, __be64 tid)
{
      hdr->base_version  = IB_MGMT_BASE_VERSION;
      hdr->mgmt_class      = IB_MGMT_CLASS_CM;
      hdr->class_version = IB_CM_CLASS_VERSION;
      hdr->method    = IB_MGMT_METHOD_SEND;
      hdr->attr_id         = attr_id;
      hdr->tid       = tid;
}

static void cm_format_req(struct cm_req_msg *req_msg,
                    struct cm_id_private *cm_id_priv,
                    struct ib_cm_req_param *param)
{
      cm_format_mad_hdr(&req_msg->hdr, CM_REQ_ATTR_ID,
                    cm_form_tid(cm_id_priv, CM_MSG_SEQUENCE_REQ));

      req_msg->local_comm_id = cm_id_priv->id.local_id;
      req_msg->service_id = param->service_id;
      req_msg->local_ca_guid = cm_id_priv->av.port->cm_dev->ca_guid;
      cm_req_set_local_qpn(req_msg, cpu_to_be32(param->qp_num));
      cm_req_set_resp_res(req_msg, param->responder_resources);
      cm_req_set_init_depth(req_msg, param->initiator_depth);
      cm_req_set_remote_resp_timeout(req_msg,
                               param->remote_cm_response_timeout);
      cm_req_set_qp_type(req_msg, param->qp_type);
      cm_req_set_flow_ctrl(req_msg, param->flow_control);
      cm_req_set_starting_psn(req_msg, cpu_to_be32(param->starting_psn));
      cm_req_set_local_resp_timeout(req_msg,
                              param->local_cm_response_timeout);
      cm_req_set_retry_count(req_msg, param->retry_count);
      req_msg->pkey = param->primary_path->pkey;
      cm_req_set_path_mtu(req_msg, param->primary_path->mtu);
      cm_req_set_rnr_retry_count(req_msg, param->rnr_retry_count);
      cm_req_set_max_cm_retries(req_msg, param->max_cm_retries);
      cm_req_set_srq(req_msg, param->srq);

      req_msg->primary_local_lid = param->primary_path->slid;
      req_msg->primary_remote_lid = param->primary_path->dlid;
      req_msg->primary_local_gid = param->primary_path->sgid;
      req_msg->primary_remote_gid = param->primary_path->dgid;
      cm_req_set_primary_flow_label(req_msg, param->primary_path->flow_label);
      cm_req_set_primary_packet_rate(req_msg, param->primary_path->rate);
      req_msg->primary_traffic_class = param->primary_path->traffic_class;
      req_msg->primary_hop_limit = param->primary_path->hop_limit;
      cm_req_set_primary_sl(req_msg, param->primary_path->sl);
      cm_req_set_primary_subnet_local(req_msg, 1); /* local only... */
      cm_req_set_primary_local_ack_timeout(req_msg,
            min(31, param->primary_path->packet_life_time + 1));

      if (param->alternate_path) {
            req_msg->alt_local_lid = param->alternate_path->slid;
            req_msg->alt_remote_lid = param->alternate_path->dlid;
            req_msg->alt_local_gid = param->alternate_path->sgid;
            req_msg->alt_remote_gid = param->alternate_path->dgid;
            cm_req_set_alt_flow_label(req_msg,
                                param->alternate_path->flow_label);
            cm_req_set_alt_packet_rate(req_msg, param->alternate_path->rate);
            req_msg->alt_traffic_class = param->alternate_path->traffic_class;
            req_msg->alt_hop_limit = param->alternate_path->hop_limit;
            cm_req_set_alt_sl(req_msg, param->alternate_path->sl);
            cm_req_set_alt_subnet_local(req_msg, 1); /* local only... */
            cm_req_set_alt_local_ack_timeout(req_msg,
                  min(31, param->alternate_path->packet_life_time + 1));
      }

      if (param->private_data && param->private_data_len)
            memcpy(req_msg->private_data, param->private_data,
                   param->private_data_len);
}

static int cm_validate_req_param(struct ib_cm_req_param *param)
{
      /* peer-to-peer not supported */
      if (param->peer_to_peer)
            return -EINVAL;

      if (!param->primary_path)
            return -EINVAL;

      if (param->qp_type != IB_QPT_RC && param->qp_type != IB_QPT_UC)
            return -EINVAL;

      if (param->private_data &&
          param->private_data_len > IB_CM_REQ_PRIVATE_DATA_SIZE)
            return -EINVAL;

      if (param->alternate_path &&
          (param->alternate_path->pkey != param->primary_path->pkey ||
           param->alternate_path->mtu != param->primary_path->mtu))
            return -EINVAL;

      return 0;
}

int ib_send_cm_req(struct ib_cm_id *cm_id,
               struct ib_cm_req_param *param)
{
      struct cm_id_private *cm_id_priv;
      struct cm_req_msg *req_msg;
      unsigned long flags;
      int ret;

      ret = cm_validate_req_param(param);
      if (ret)
            return ret;

      /* Verify that we're not in timewait. */
      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id->state != IB_CM_IDLE) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            ret = -EINVAL;
            goto out;
      }
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      cm_id_priv->timewait_info = cm_create_timewait_info(cm_id_priv->
                                              id.local_id);
      if (IS_ERR(cm_id_priv->timewait_info)) {
            ret = PTR_ERR(cm_id_priv->timewait_info);
            goto out;
      }

      ret = cm_init_av_by_path(param->primary_path, &cm_id_priv->av);
      if (ret)
            goto error1;
      if (param->alternate_path) {
            ret = cm_init_av_by_path(param->alternate_path,
                               &cm_id_priv->alt_av);
            if (ret)
                  goto error1;
      }
      cm_id->service_id = param->service_id;
      cm_id->service_mask = __constant_cpu_to_be64(~0ULL);
      cm_id_priv->timeout_ms = cm_convert_to_ms(
                            param->primary_path->packet_life_time) * 2 +
                         cm_convert_to_ms(
                            param->remote_cm_response_timeout);
      cm_id_priv->max_cm_retries = param->max_cm_retries;
      cm_id_priv->initiator_depth = param->initiator_depth;
      cm_id_priv->responder_resources = param->responder_resources;
      cm_id_priv->retry_count = param->retry_count;
      cm_id_priv->path_mtu = param->primary_path->mtu;
      cm_id_priv->qp_type = param->qp_type;

      ret = cm_alloc_msg(cm_id_priv, &cm_id_priv->msg);
      if (ret)
            goto error1;

      req_msg = (struct cm_req_msg *) cm_id_priv->msg->mad;
      cm_format_req(req_msg, cm_id_priv, param);
      cm_id_priv->tid = req_msg->hdr.tid;
      cm_id_priv->msg->timeout_ms = cm_id_priv->timeout_ms;
      cm_id_priv->msg->context[1] = (void *) (unsigned long) IB_CM_REQ_SENT;

      cm_id_priv->local_qpn = cm_req_get_local_qpn(req_msg);
      cm_id_priv->rq_psn = cm_req_get_starting_psn(req_msg);
      cm_id_priv->local_ack_timeout =
                        cm_req_get_primary_local_ack_timeout(req_msg);

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      ret = ib_post_send_mad(cm_id_priv->msg, NULL);
      if (ret) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            goto error2;
      }
      BUG_ON(cm_id->state != IB_CM_IDLE);
      cm_id->state = IB_CM_REQ_SENT;
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return 0;

error2:     cm_free_msg(cm_id_priv->msg);
error1:     kfree(cm_id_priv->timewait_info);
out:  return ret;
}
EXPORT_SYMBOL(ib_send_cm_req);

static int cm_issue_rej(struct cm_port *port,
                  struct ib_mad_recv_wc *mad_recv_wc,
                  enum ib_cm_rej_reason reason,
                  enum cm_msg_response msg_rejected,
                  void *ari, u8 ari_length)
{
      struct ib_mad_send_buf *msg = NULL;
      struct cm_rej_msg *rej_msg, *rcv_msg;
      int ret;

      ret = cm_alloc_response_msg(port, mad_recv_wc, &msg);
      if (ret)
            return ret;

      /* We just need common CM header information.  Cast to any message. */
      rcv_msg = (struct cm_rej_msg *) mad_recv_wc->recv_buf.mad;
      rej_msg = (struct cm_rej_msg *) msg->mad;

      cm_format_mad_hdr(&rej_msg->hdr, CM_REJ_ATTR_ID, rcv_msg->hdr.tid);
      rej_msg->remote_comm_id = rcv_msg->local_comm_id;
      rej_msg->local_comm_id = rcv_msg->remote_comm_id;
      cm_rej_set_msg_rejected(rej_msg, msg_rejected);
      rej_msg->reason = cpu_to_be16(reason);

      if (ari && ari_length) {
            cm_rej_set_reject_info_len(rej_msg, ari_length);
            memcpy(rej_msg->ari, ari, ari_length);
      }

      ret = ib_post_send_mad(msg, NULL);
      if (ret)
            cm_free_msg(msg);

      return ret;
}

static inline int cm_is_active_peer(__be64 local_ca_guid, __be64 remote_ca_guid,
                            __be32 local_qpn, __be32 remote_qpn)
{
      return (be64_to_cpu(local_ca_guid) > be64_to_cpu(remote_ca_guid) ||
            ((local_ca_guid == remote_ca_guid) &&
             (be32_to_cpu(local_qpn) > be32_to_cpu(remote_qpn))));
}

static void cm_format_paths_from_req(struct cm_req_msg *req_msg,
                                  struct ib_sa_path_rec *primary_path,
                                  struct ib_sa_path_rec *alt_path)
{
      memset(primary_path, 0, sizeof *primary_path);
      primary_path->dgid = req_msg->primary_local_gid;
      primary_path->sgid = req_msg->primary_remote_gid;
      primary_path->dlid = req_msg->primary_local_lid;
      primary_path->slid = req_msg->primary_remote_lid;
      primary_path->flow_label = cm_req_get_primary_flow_label(req_msg);
      primary_path->hop_limit = req_msg->primary_hop_limit;
      primary_path->traffic_class = req_msg->primary_traffic_class;
      primary_path->reversible = 1;
      primary_path->pkey = req_msg->pkey;
      primary_path->sl = cm_req_get_primary_sl(req_msg);
      primary_path->mtu_selector = IB_SA_EQ;
      primary_path->mtu = cm_req_get_path_mtu(req_msg);
      primary_path->rate_selector = IB_SA_EQ;
      primary_path->rate = cm_req_get_primary_packet_rate(req_msg);
      primary_path->packet_life_time_selector = IB_SA_EQ;
      primary_path->packet_life_time =
            cm_req_get_primary_local_ack_timeout(req_msg);
      primary_path->packet_life_time -= (primary_path->packet_life_time > 0);

      if (req_msg->alt_local_lid) {
            memset(alt_path, 0, sizeof *alt_path);
            alt_path->dgid = req_msg->alt_local_gid;
            alt_path->sgid = req_msg->alt_remote_gid;
            alt_path->dlid = req_msg->alt_local_lid;
            alt_path->slid = req_msg->alt_remote_lid;
            alt_path->flow_label = cm_req_get_alt_flow_label(req_msg);
            alt_path->hop_limit = req_msg->alt_hop_limit;
            alt_path->traffic_class = req_msg->alt_traffic_class;
            alt_path->reversible = 1;
            alt_path->pkey = req_msg->pkey;
            alt_path->sl = cm_req_get_alt_sl(req_msg);
            alt_path->mtu_selector = IB_SA_EQ;
            alt_path->mtu = cm_req_get_path_mtu(req_msg);
            alt_path->rate_selector = IB_SA_EQ;
            alt_path->rate = cm_req_get_alt_packet_rate(req_msg);
            alt_path->packet_life_time_selector = IB_SA_EQ;
            alt_path->packet_life_time =
                  cm_req_get_alt_local_ack_timeout(req_msg);
            alt_path->packet_life_time -= (alt_path->packet_life_time > 0);
      }
}

static void cm_format_req_event(struct cm_work *work,
                        struct cm_id_private *cm_id_priv,
                        struct ib_cm_id *listen_id)
{
      struct cm_req_msg *req_msg;
      struct ib_cm_req_event_param *param;

      req_msg = (struct cm_req_msg *)work->mad_recv_wc->recv_buf.mad;
      param = &work->cm_event.param.req_rcvd;
      param->listen_id = listen_id;
      param->port = cm_id_priv->av.port->port_num;
      param->primary_path = &work->path[0];
      if (req_msg->alt_local_lid)
            param->alternate_path = &work->path[1];
      else
            param->alternate_path = NULL;
      param->remote_ca_guid = req_msg->local_ca_guid;
      param->remote_qkey = be32_to_cpu(req_msg->local_qkey);
      param->remote_qpn = be32_to_cpu(cm_req_get_local_qpn(req_msg));
      param->qp_type = cm_req_get_qp_type(req_msg);
      param->starting_psn = be32_to_cpu(cm_req_get_starting_psn(req_msg));
      param->responder_resources = cm_req_get_init_depth(req_msg);
      param->initiator_depth = cm_req_get_resp_res(req_msg);
      param->local_cm_response_timeout =
                              cm_req_get_remote_resp_timeout(req_msg);
      param->flow_control = cm_req_get_flow_ctrl(req_msg);
      param->remote_cm_response_timeout =
                              cm_req_get_local_resp_timeout(req_msg);
      param->retry_count = cm_req_get_retry_count(req_msg);
      param->rnr_retry_count = cm_req_get_rnr_retry_count(req_msg);
      param->srq = cm_req_get_srq(req_msg);
      work->cm_event.private_data = &req_msg->private_data;
}

static void cm_process_work(struct cm_id_private *cm_id_priv,
                      struct cm_work *work)
{
      unsigned long flags;
      int ret;

      /* We will typically only have the current event to report. */
      ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, &work->cm_event);
      cm_free_work(work);

      while (!ret && !atomic_add_negative(-1, &cm_id_priv->work_count)) {
            spin_lock_irqsave(&cm_id_priv->lock, flags);
            work = cm_dequeue_work(cm_id_priv);
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            BUG_ON(!work);
            ret = cm_id_priv->id.cm_handler(&cm_id_priv->id,
                                    &work->cm_event);
            cm_free_work(work);
      }
      cm_deref_id(cm_id_priv);
      if (ret)
            cm_destroy_id(&cm_id_priv->id, ret);
}

static void cm_format_mra(struct cm_mra_msg *mra_msg,
                    struct cm_id_private *cm_id_priv,
                    enum cm_msg_response msg_mraed, u8 service_timeout,
                    const void *private_data, u8 private_data_len)
{
      cm_format_mad_hdr(&mra_msg->hdr, CM_MRA_ATTR_ID, cm_id_priv->tid);
      cm_mra_set_msg_mraed(mra_msg, msg_mraed);
      mra_msg->local_comm_id = cm_id_priv->id.local_id;
      mra_msg->remote_comm_id = cm_id_priv->id.remote_id;
      cm_mra_set_service_timeout(mra_msg, service_timeout);

      if (private_data && private_data_len)
            memcpy(mra_msg->private_data, private_data, private_data_len);
}

static void cm_format_rej(struct cm_rej_msg *rej_msg,
                    struct cm_id_private *cm_id_priv,
                    enum ib_cm_rej_reason reason,
                    void *ari,
                    u8 ari_length,
                    const void *private_data,
                    u8 private_data_len)
{
      cm_format_mad_hdr(&rej_msg->hdr, CM_REJ_ATTR_ID, cm_id_priv->tid);
      rej_msg->remote_comm_id = cm_id_priv->id.remote_id;

      switch(cm_id_priv->id.state) {
      case IB_CM_REQ_RCVD:
            rej_msg->local_comm_id = 0;
            cm_rej_set_msg_rejected(rej_msg, CM_MSG_RESPONSE_REQ);
            break;
      case IB_CM_MRA_REQ_SENT:
            rej_msg->local_comm_id = cm_id_priv->id.local_id;
            cm_rej_set_msg_rejected(rej_msg, CM_MSG_RESPONSE_REQ);
            break;
      case IB_CM_REP_RCVD:
      case IB_CM_MRA_REP_SENT:
            rej_msg->local_comm_id = cm_id_priv->id.local_id;
            cm_rej_set_msg_rejected(rej_msg, CM_MSG_RESPONSE_REP);
            break;
      default:
            rej_msg->local_comm_id = cm_id_priv->id.local_id;
            cm_rej_set_msg_rejected(rej_msg, CM_MSG_RESPONSE_OTHER);
            break;
      }

      rej_msg->reason = cpu_to_be16(reason);
      if (ari && ari_length) {
            cm_rej_set_reject_info_len(rej_msg, ari_length);
            memcpy(rej_msg->ari, ari, ari_length);
      }

      if (private_data && private_data_len)
            memcpy(rej_msg->private_data, private_data, private_data_len);
}

static void cm_dup_req_handler(struct cm_work *work,
                         struct cm_id_private *cm_id_priv)
{
      struct ib_mad_send_buf *msg = NULL;
      unsigned long flags;
      int ret;

      /* Quick state check to discard duplicate REQs. */
      if (cm_id_priv->id.state == IB_CM_REQ_RCVD)
            return;

      ret = cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg);
      if (ret)
            return;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id_priv->id.state) {
      case IB_CM_MRA_REQ_SENT:
            cm_format_mra((struct cm_mra_msg *) msg->mad, cm_id_priv,
                        CM_MSG_RESPONSE_REQ, cm_id_priv->service_timeout,
                        cm_id_priv->private_data,
                        cm_id_priv->private_data_len);
            break;
      case IB_CM_TIMEWAIT:
            cm_format_rej((struct cm_rej_msg *) msg->mad, cm_id_priv,
                        IB_CM_REJ_STALE_CONN, NULL, 0, NULL, 0);
            break;
      default:
            goto unlock;
      }
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      ret = ib_post_send_mad(msg, NULL);
      if (ret)
            goto free;
      return;

unlock:     spin_unlock_irqrestore(&cm_id_priv->lock, flags);
free: cm_free_msg(msg);
}

static struct cm_id_private * cm_match_req(struct cm_work *work,
                                 struct cm_id_private *cm_id_priv)
{
      struct cm_id_private *listen_cm_id_priv, *cur_cm_id_priv;
      struct cm_timewait_info *timewait_info;
      struct cm_req_msg *req_msg;
      unsigned long flags;

      req_msg = (struct cm_req_msg *)work->mad_recv_wc->recv_buf.mad;

      /* Check for duplicate REQ and stale connections. */
      spin_lock_irqsave(&cm.lock, flags);
      timewait_info = cm_insert_remote_id(cm_id_priv->timewait_info);
      if (!timewait_info)
            timewait_info = cm_insert_remote_qpn(cm_id_priv->timewait_info);

      if (timewait_info) {
            cur_cm_id_priv = cm_get_id(timewait_info->work.local_id,
                                 timewait_info->work.remote_id);
            spin_unlock_irqrestore(&cm.lock, flags);
            if (cur_cm_id_priv) {
                  cm_dup_req_handler(work, cur_cm_id_priv);
                  cm_deref_id(cur_cm_id_priv);
            } else
                  cm_issue_rej(work->port, work->mad_recv_wc,
                             IB_CM_REJ_STALE_CONN, CM_MSG_RESPONSE_REQ,
                             NULL, 0);
            goto error;
      }

      /* Find matching listen request. */
      listen_cm_id_priv = cm_find_listen(cm_id_priv->id.device,
                                 req_msg->service_id,
                                 req_msg->private_data);
      if (!listen_cm_id_priv) {
            spin_unlock_irqrestore(&cm.lock, flags);
            cm_issue_rej(work->port, work->mad_recv_wc,
                       IB_CM_REJ_INVALID_SERVICE_ID, CM_MSG_RESPONSE_REQ,
                       NULL, 0);
            goto error;
      }
      atomic_inc(&listen_cm_id_priv->refcount);
      atomic_inc(&cm_id_priv->refcount);
      cm_id_priv->id.state = IB_CM_REQ_RCVD;
      atomic_inc(&cm_id_priv->work_count);
      spin_unlock_irqrestore(&cm.lock, flags);
      return listen_cm_id_priv;

error:      cm_cleanup_timewait(cm_id_priv->timewait_info);
      return NULL;
}

static int cm_req_handler(struct cm_work *work)
{
      struct ib_cm_id *cm_id;
      struct cm_id_private *cm_id_priv, *listen_cm_id_priv;
      struct cm_req_msg *req_msg;
      int ret;

      req_msg = (struct cm_req_msg *)work->mad_recv_wc->recv_buf.mad;

      cm_id = ib_create_cm_id(work->port->cm_dev->device, NULL, NULL);
      if (IS_ERR(cm_id))
            return PTR_ERR(cm_id);

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      cm_id_priv->id.remote_id = req_msg->local_comm_id;
      cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
                        work->mad_recv_wc->recv_buf.grh,
                        &cm_id_priv->av);
      cm_id_priv->timewait_info = cm_create_timewait_info(cm_id_priv->
                                              id.local_id);
      if (IS_ERR(cm_id_priv->timewait_info)) {
            ret = PTR_ERR(cm_id_priv->timewait_info);
            goto error1;
      }
      cm_id_priv->timewait_info->work.remote_id = req_msg->local_comm_id;
      cm_id_priv->timewait_info->remote_ca_guid = req_msg->local_ca_guid;
      cm_id_priv->timewait_info->remote_qpn = cm_req_get_local_qpn(req_msg);

      listen_cm_id_priv = cm_match_req(work, cm_id_priv);
      if (!listen_cm_id_priv) {
            ret = -EINVAL;
            goto error2;
      }

      cm_id_priv->id.cm_handler = listen_cm_id_priv->id.cm_handler;
      cm_id_priv->id.context = listen_cm_id_priv->id.context;
      cm_id_priv->id.service_id = req_msg->service_id;
      cm_id_priv->id.service_mask = __constant_cpu_to_be64(~0ULL);

      cm_format_paths_from_req(req_msg, &work->path[0], &work->path[1]);
      ret = cm_init_av_by_path(&work->path[0], &cm_id_priv->av);
      if (ret)
            goto error3;
      if (req_msg->alt_local_lid) {
            ret = cm_init_av_by_path(&work->path[1], &cm_id_priv->alt_av);
            if (ret)
                  goto error3;
      }
      cm_id_priv->tid = req_msg->hdr.tid;
      cm_id_priv->timeout_ms = cm_convert_to_ms(
                              cm_req_get_local_resp_timeout(req_msg));
      cm_id_priv->max_cm_retries = cm_req_get_max_cm_retries(req_msg);
      cm_id_priv->remote_qpn = cm_req_get_local_qpn(req_msg);
      cm_id_priv->initiator_depth = cm_req_get_resp_res(req_msg);
      cm_id_priv->responder_resources = cm_req_get_init_depth(req_msg);
      cm_id_priv->path_mtu = cm_req_get_path_mtu(req_msg);
      cm_id_priv->sq_psn = cm_req_get_starting_psn(req_msg);
      cm_id_priv->local_ack_timeout =
                        cm_req_get_primary_local_ack_timeout(req_msg);
      cm_id_priv->retry_count = cm_req_get_retry_count(req_msg);
      cm_id_priv->rnr_retry_count = cm_req_get_rnr_retry_count(req_msg);
      cm_id_priv->qp_type = cm_req_get_qp_type(req_msg);

      cm_format_req_event(work, cm_id_priv, &listen_cm_id_priv->id);
      cm_process_work(cm_id_priv, work);
      cm_deref_id(listen_cm_id_priv);
      return 0;

error3:     atomic_dec(&cm_id_priv->refcount);
      cm_deref_id(listen_cm_id_priv);
      cm_cleanup_timewait(cm_id_priv->timewait_info);
error2:     kfree(cm_id_priv->timewait_info);
      cm_id_priv->timewait_info = NULL;
error1:     ib_destroy_cm_id(&cm_id_priv->id);
      return ret;
}

static void cm_format_rep(struct cm_rep_msg *rep_msg,
                    struct cm_id_private *cm_id_priv,
                    struct ib_cm_rep_param *param)
{
      cm_format_mad_hdr(&rep_msg->hdr, CM_REP_ATTR_ID, cm_id_priv->tid);
      rep_msg->local_comm_id = cm_id_priv->id.local_id;
      rep_msg->remote_comm_id = cm_id_priv->id.remote_id;
      cm_rep_set_local_qpn(rep_msg, cpu_to_be32(param->qp_num));
      cm_rep_set_starting_psn(rep_msg, cpu_to_be32(param->starting_psn));
      rep_msg->resp_resources = param->responder_resources;
      rep_msg->initiator_depth = param->initiator_depth;
      cm_rep_set_target_ack_delay(rep_msg, param->target_ack_delay);
      cm_rep_set_failover(rep_msg, param->failover_accepted);
      cm_rep_set_flow_ctrl(rep_msg, param->flow_control);
      cm_rep_set_rnr_retry_count(rep_msg, param->rnr_retry_count);
      cm_rep_set_srq(rep_msg, param->srq);
      rep_msg->local_ca_guid = cm_id_priv->av.port->cm_dev->ca_guid;

      if (param->private_data && param->private_data_len)
            memcpy(rep_msg->private_data, param->private_data,
                   param->private_data_len);
}

int ib_send_cm_rep(struct ib_cm_id *cm_id,
               struct ib_cm_rep_param *param)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      struct cm_rep_msg *rep_msg;
      unsigned long flags;
      int ret;

      if (param->private_data &&
          param->private_data_len > IB_CM_REP_PRIVATE_DATA_SIZE)
            return -EINVAL;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id->state != IB_CM_REQ_RCVD &&
          cm_id->state != IB_CM_MRA_REQ_SENT) {
            ret = -EINVAL;
            goto out;
      }

      ret = cm_alloc_msg(cm_id_priv, &msg);
      if (ret)
            goto out;

      rep_msg = (struct cm_rep_msg *) msg->mad;
      cm_format_rep(rep_msg, cm_id_priv, param);
      msg->timeout_ms = cm_id_priv->timeout_ms;
      msg->context[1] = (void *) (unsigned long) IB_CM_REP_SENT;

      ret = ib_post_send_mad(msg, NULL);
      if (ret) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_free_msg(msg);
            return ret;
      }

      cm_id->state = IB_CM_REP_SENT;
      cm_id_priv->msg = msg;
      cm_id_priv->initiator_depth = param->initiator_depth;
      cm_id_priv->responder_resources = param->responder_resources;
      cm_id_priv->rq_psn = cm_rep_get_starting_psn(rep_msg);
      cm_id_priv->local_qpn = cm_rep_get_local_qpn(rep_msg);

out:  spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_rep);

static void cm_format_rtu(struct cm_rtu_msg *rtu_msg,
                    struct cm_id_private *cm_id_priv,
                    const void *private_data,
                    u8 private_data_len)
{
      cm_format_mad_hdr(&rtu_msg->hdr, CM_RTU_ATTR_ID, cm_id_priv->tid);
      rtu_msg->local_comm_id = cm_id_priv->id.local_id;
      rtu_msg->remote_comm_id = cm_id_priv->id.remote_id;

      if (private_data && private_data_len)
            memcpy(rtu_msg->private_data, private_data, private_data_len);
}

int ib_send_cm_rtu(struct ib_cm_id *cm_id,
               const void *private_data,
               u8 private_data_len)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      unsigned long flags;
      void *data;
      int ret;

      if (private_data && private_data_len > IB_CM_RTU_PRIVATE_DATA_SIZE)
            return -EINVAL;

      data = cm_copy_private_data(private_data, private_data_len);
      if (IS_ERR(data))
            return PTR_ERR(data);

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id->state != IB_CM_REP_RCVD &&
          cm_id->state != IB_CM_MRA_REP_SENT) {
            ret = -EINVAL;
            goto error;
      }

      ret = cm_alloc_msg(cm_id_priv, &msg);
      if (ret)
            goto error;

      cm_format_rtu((struct cm_rtu_msg *) msg->mad, cm_id_priv,
                  private_data, private_data_len);

      ret = ib_post_send_mad(msg, NULL);
      if (ret) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_free_msg(msg);
            kfree(data);
            return ret;
      }

      cm_id->state = IB_CM_ESTABLISHED;
      cm_set_private_data(cm_id_priv, data, private_data_len);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return 0;

error:      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      kfree(data);
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_rtu);

static void cm_format_rep_event(struct cm_work *work)
{
      struct cm_rep_msg *rep_msg;
      struct ib_cm_rep_event_param *param;

      rep_msg = (struct cm_rep_msg *)work->mad_recv_wc->recv_buf.mad;
      param = &work->cm_event.param.rep_rcvd;
      param->remote_ca_guid = rep_msg->local_ca_guid;
      param->remote_qkey = be32_to_cpu(rep_msg->local_qkey);
      param->remote_qpn = be32_to_cpu(cm_rep_get_local_qpn(rep_msg));
      param->starting_psn = be32_to_cpu(cm_rep_get_starting_psn(rep_msg));
      param->responder_resources = rep_msg->initiator_depth;
      param->initiator_depth = rep_msg->resp_resources;
      param->target_ack_delay = cm_rep_get_target_ack_delay(rep_msg);
      param->failover_accepted = cm_rep_get_failover(rep_msg);
      param->flow_control = cm_rep_get_flow_ctrl(rep_msg);
      param->rnr_retry_count = cm_rep_get_rnr_retry_count(rep_msg);
      param->srq = cm_rep_get_srq(rep_msg);
      work->cm_event.private_data = &rep_msg->private_data;
}

static void cm_dup_rep_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      struct cm_rep_msg *rep_msg;
      struct ib_mad_send_buf *msg = NULL;
      unsigned long flags;
      int ret;

      rep_msg = (struct cm_rep_msg *) work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_id(rep_msg->remote_comm_id,
                           rep_msg->local_comm_id);
      if (!cm_id_priv)
            return;

      ret = cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg);
      if (ret)
            goto deref;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id_priv->id.state == IB_CM_ESTABLISHED)
            cm_format_rtu((struct cm_rtu_msg *) msg->mad, cm_id_priv,
                        cm_id_priv->private_data,
                        cm_id_priv->private_data_len);
      else if (cm_id_priv->id.state == IB_CM_MRA_REP_SENT)
            cm_format_mra((struct cm_mra_msg *) msg->mad, cm_id_priv,
                        CM_MSG_RESPONSE_REP, cm_id_priv->service_timeout,
                        cm_id_priv->private_data,
                        cm_id_priv->private_data_len);
      else
            goto unlock;
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      ret = ib_post_send_mad(msg, NULL);
      if (ret)
            goto free;
      goto deref;

unlock:     spin_unlock_irqrestore(&cm_id_priv->lock, flags);
free: cm_free_msg(msg);
deref:      cm_deref_id(cm_id_priv);
}

static int cm_rep_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      struct cm_rep_msg *rep_msg;
      unsigned long flags;
      int ret;

      rep_msg = (struct cm_rep_msg *)work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_id(rep_msg->remote_comm_id, 0);
      if (!cm_id_priv) {
            cm_dup_rep_handler(work);
            return -EINVAL;
      }

      cm_format_rep_event(work);

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id_priv->id.state) {
      case IB_CM_REQ_SENT:
      case IB_CM_MRA_REQ_RCVD:
            break;
      default:
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            ret = -EINVAL;
            goto error;
      }

      cm_id_priv->timewait_info->work.remote_id = rep_msg->local_comm_id;
      cm_id_priv->timewait_info->remote_ca_guid = rep_msg->local_ca_guid;
      cm_id_priv->timewait_info->remote_qpn = cm_rep_get_local_qpn(rep_msg);

      spin_lock(&cm.lock);
      /* Check for duplicate REP. */
      if (cm_insert_remote_id(cm_id_priv->timewait_info)) {
            spin_unlock(&cm.lock);
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            ret = -EINVAL;
            goto error;
      }
      /* Check for a stale connection. */
      if (cm_insert_remote_qpn(cm_id_priv->timewait_info)) {
            rb_erase(&cm_id_priv->timewait_info->remote_id_node,
                   &cm.remote_id_table);
            cm_id_priv->timewait_info->inserted_remote_id = 0;
            spin_unlock(&cm.lock);
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_issue_rej(work->port, work->mad_recv_wc,
                       IB_CM_REJ_STALE_CONN, CM_MSG_RESPONSE_REP,
                       NULL, 0);
            ret = -EINVAL;
            goto error;
      }
      spin_unlock(&cm.lock);

      cm_id_priv->id.state = IB_CM_REP_RCVD;
      cm_id_priv->id.remote_id = rep_msg->local_comm_id;
      cm_id_priv->remote_qpn = cm_rep_get_local_qpn(rep_msg);
      cm_id_priv->initiator_depth = rep_msg->resp_resources;
      cm_id_priv->responder_resources = rep_msg->initiator_depth;
      cm_id_priv->sq_psn = cm_rep_get_starting_psn(rep_msg);
      cm_id_priv->rnr_retry_count = cm_rep_get_rnr_retry_count(rep_msg);

      /* todo: handle peer_to_peer */

      ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;

error:
      cm_deref_id(cm_id_priv);
      return ret;
}

static int cm_establish_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      unsigned long flags;
      int ret;

      /* See comment in ib_cm_establish about lookup. */
      cm_id_priv = cm_acquire_id(work->local_id, work->remote_id);
      if (!cm_id_priv)
            return -EINVAL;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id_priv->id.state != IB_CM_ESTABLISHED) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            goto out;
      }

      ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;
out:
      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

static int cm_rtu_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      struct cm_rtu_msg *rtu_msg;
      unsigned long flags;
      int ret;

      rtu_msg = (struct cm_rtu_msg *)work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_id(rtu_msg->remote_comm_id,
                           rtu_msg->local_comm_id);
      if (!cm_id_priv)
            return -EINVAL;

      work->cm_event.private_data = &rtu_msg->private_data;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id_priv->id.state != IB_CM_REP_SENT &&
          cm_id_priv->id.state != IB_CM_MRA_REP_RCVD) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            goto out;
      }
      cm_id_priv->id.state = IB_CM_ESTABLISHED;

      ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;
out:
      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

static void cm_format_dreq(struct cm_dreq_msg *dreq_msg,
                    struct cm_id_private *cm_id_priv,
                    const void *private_data,
                    u8 private_data_len)
{
      cm_format_mad_hdr(&dreq_msg->hdr, CM_DREQ_ATTR_ID,
                    cm_form_tid(cm_id_priv, CM_MSG_SEQUENCE_DREQ));
      dreq_msg->local_comm_id = cm_id_priv->id.local_id;
      dreq_msg->remote_comm_id = cm_id_priv->id.remote_id;
      cm_dreq_set_remote_qpn(dreq_msg, cm_id_priv->remote_qpn);

      if (private_data && private_data_len)
            memcpy(dreq_msg->private_data, private_data, private_data_len);
}

int ib_send_cm_dreq(struct ib_cm_id *cm_id,
                const void *private_data,
                u8 private_data_len)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      unsigned long flags;
      int ret;

      if (private_data && private_data_len > IB_CM_DREQ_PRIVATE_DATA_SIZE)
            return -EINVAL;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id->state != IB_CM_ESTABLISHED) {
            ret = -EINVAL;
            goto out;
      }

      ret = cm_alloc_msg(cm_id_priv, &msg);
      if (ret) {
            cm_enter_timewait(cm_id_priv);
            goto out;
      }

      cm_format_dreq((struct cm_dreq_msg *) msg->mad, cm_id_priv,
                   private_data, private_data_len);
      msg->timeout_ms = cm_id_priv->timeout_ms;
      msg->context[1] = (void *) (unsigned long) IB_CM_DREQ_SENT;

      ret = ib_post_send_mad(msg, NULL);
      if (ret) {
            cm_enter_timewait(cm_id_priv);
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_free_msg(msg);
            return ret;
      }

      cm_id->state = IB_CM_DREQ_SENT;
      cm_id_priv->msg = msg;
out:  spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_dreq);

static void cm_format_drep(struct cm_drep_msg *drep_msg,
                    struct cm_id_private *cm_id_priv,
                    const void *private_data,
                    u8 private_data_len)
{
      cm_format_mad_hdr(&drep_msg->hdr, CM_DREP_ATTR_ID, cm_id_priv->tid);
      drep_msg->local_comm_id = cm_id_priv->id.local_id;
      drep_msg->remote_comm_id = cm_id_priv->id.remote_id;

      if (private_data && private_data_len)
            memcpy(drep_msg->private_data, private_data, private_data_len);
}

int ib_send_cm_drep(struct ib_cm_id *cm_id,
                const void *private_data,
                u8 private_data_len)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      unsigned long flags;
      void *data;
      int ret;

      if (private_data && private_data_len > IB_CM_DREP_PRIVATE_DATA_SIZE)
            return -EINVAL;

      data = cm_copy_private_data(private_data, private_data_len);
      if (IS_ERR(data))
            return PTR_ERR(data);

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id->state != IB_CM_DREQ_RCVD) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            kfree(data);
            return -EINVAL;
      }

      cm_set_private_data(cm_id_priv, data, private_data_len);
      cm_enter_timewait(cm_id_priv);

      ret = cm_alloc_msg(cm_id_priv, &msg);
      if (ret)
            goto out;

      cm_format_drep((struct cm_drep_msg *) msg->mad, cm_id_priv,
                   private_data, private_data_len);

      ret = ib_post_send_mad(msg, NULL);
      if (ret) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_free_msg(msg);
            return ret;
      }

out:  spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_drep);

static int cm_dreq_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      struct cm_dreq_msg *dreq_msg;
      struct ib_mad_send_buf *msg = NULL;
      unsigned long flags;
      int ret;

      dreq_msg = (struct cm_dreq_msg *)work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_id(dreq_msg->remote_comm_id,
                           dreq_msg->local_comm_id);
      if (!cm_id_priv)
            return -EINVAL;

      work->cm_event.private_data = &dreq_msg->private_data;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id_priv->local_qpn != cm_dreq_get_remote_qpn(dreq_msg))
            goto unlock;

      switch (cm_id_priv->id.state) {
      case IB_CM_REP_SENT:
      case IB_CM_DREQ_SENT:
            ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
            break;
      case IB_CM_ESTABLISHED:
      case IB_CM_MRA_REP_RCVD:
            break;
      case IB_CM_TIMEWAIT:
            if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
                  goto unlock;

            cm_format_drep((struct cm_drep_msg *) msg->mad, cm_id_priv,
                         cm_id_priv->private_data,
                         cm_id_priv->private_data_len);
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);

            if (ib_post_send_mad(msg, NULL))
                  cm_free_msg(msg);
            goto deref;
      default:
            goto unlock;
      }
      cm_id_priv->id.state = IB_CM_DREQ_RCVD;
      cm_id_priv->tid = dreq_msg->hdr.tid;
      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;

unlock:     spin_unlock_irqrestore(&cm_id_priv->lock, flags);
deref:      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

static int cm_drep_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      struct cm_drep_msg *drep_msg;
      unsigned long flags;
      int ret;

      drep_msg = (struct cm_drep_msg *)work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_id(drep_msg->remote_comm_id,
                           drep_msg->local_comm_id);
      if (!cm_id_priv)
            return -EINVAL;

      work->cm_event.private_data = &drep_msg->private_data;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id_priv->id.state != IB_CM_DREQ_SENT &&
          cm_id_priv->id.state != IB_CM_DREQ_RCVD) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            goto out;
      }
      cm_enter_timewait(cm_id_priv);

      ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;
out:
      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

int ib_send_cm_rej(struct ib_cm_id *cm_id,
               enum ib_cm_rej_reason reason,
               void *ari,
               u8 ari_length,
               const void *private_data,
               u8 private_data_len)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      unsigned long flags;
      int ret;

      if ((private_data && private_data_len > IB_CM_REJ_PRIVATE_DATA_SIZE) ||
          (ari && ari_length > IB_CM_REJ_ARI_LENGTH))
            return -EINVAL;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id->state) {
      case IB_CM_REQ_SENT:
      case IB_CM_MRA_REQ_RCVD:
      case IB_CM_REQ_RCVD:
      case IB_CM_MRA_REQ_SENT:
      case IB_CM_REP_RCVD:
      case IB_CM_MRA_REP_SENT:
            ret = cm_alloc_msg(cm_id_priv, &msg);
            if (!ret)
                  cm_format_rej((struct cm_rej_msg *) msg->mad,
                              cm_id_priv, reason, ari, ari_length,
                              private_data, private_data_len);

            cm_reset_to_idle(cm_id_priv);
            break;
      case IB_CM_REP_SENT:
      case IB_CM_MRA_REP_RCVD:
            ret = cm_alloc_msg(cm_id_priv, &msg);
            if (!ret)
                  cm_format_rej((struct cm_rej_msg *) msg->mad,
                              cm_id_priv, reason, ari, ari_length,
                              private_data, private_data_len);

            cm_enter_timewait(cm_id_priv);
            break;
      default:
            ret = -EINVAL;
            goto out;
      }

      if (ret)
            goto out;

      ret = ib_post_send_mad(msg, NULL);
      if (ret)
            cm_free_msg(msg);

out:  spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_rej);

static void cm_format_rej_event(struct cm_work *work)
{
      struct cm_rej_msg *rej_msg;
      struct ib_cm_rej_event_param *param;

      rej_msg = (struct cm_rej_msg *)work->mad_recv_wc->recv_buf.mad;
      param = &work->cm_event.param.rej_rcvd;
      param->ari = rej_msg->ari;
      param->ari_length = cm_rej_get_reject_info_len(rej_msg);
      param->reason = __be16_to_cpu(rej_msg->reason);
      work->cm_event.private_data = &rej_msg->private_data;
}

static struct cm_id_private * cm_acquire_rejected_id(struct cm_rej_msg *rej_msg)
{
      struct cm_timewait_info *timewait_info;
      struct cm_id_private *cm_id_priv;
      unsigned long flags;
      __be32 remote_id;

      remote_id = rej_msg->local_comm_id;

      if (__be16_to_cpu(rej_msg->reason) == IB_CM_REJ_TIMEOUT) {
            spin_lock_irqsave(&cm.lock, flags);
            timewait_info = cm_find_remote_id( *((__be64 *) rej_msg->ari),
                                      remote_id);
            if (!timewait_info) {
                  spin_unlock_irqrestore(&cm.lock, flags);
                  return NULL;
            }
            cm_id_priv = idr_find(&cm.local_id_table,
                              (__force int) timewait_info->work.local_id);
            if (cm_id_priv) {
                  if (cm_id_priv->id.remote_id == remote_id)
                        atomic_inc(&cm_id_priv->refcount);
                  else
                        cm_id_priv = NULL;
            }
            spin_unlock_irqrestore(&cm.lock, flags);
      } else if (cm_rej_get_msg_rejected(rej_msg) == CM_MSG_RESPONSE_REQ)
            cm_id_priv = cm_acquire_id(rej_msg->remote_comm_id, 0);
      else
            cm_id_priv = cm_acquire_id(rej_msg->remote_comm_id, remote_id);

      return cm_id_priv;
}

static int cm_rej_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      struct cm_rej_msg *rej_msg;
      unsigned long flags;
      int ret;

      rej_msg = (struct cm_rej_msg *)work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_rejected_id(rej_msg);
      if (!cm_id_priv)
            return -EINVAL;

      cm_format_rej_event(work);

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id_priv->id.state) {
      case IB_CM_REQ_SENT:
      case IB_CM_MRA_REQ_RCVD:
      case IB_CM_REP_SENT:
      case IB_CM_MRA_REP_RCVD:
            ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
            /* fall through */
      case IB_CM_REQ_RCVD:
      case IB_CM_MRA_REQ_SENT:
            if (__be16_to_cpu(rej_msg->reason) == IB_CM_REJ_STALE_CONN)
                  cm_enter_timewait(cm_id_priv);
            else
                  cm_reset_to_idle(cm_id_priv);
            break;
      case IB_CM_DREQ_SENT:
            ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
            /* fall through */
      case IB_CM_REP_RCVD:
      case IB_CM_MRA_REP_SENT:
      case IB_CM_ESTABLISHED:
            cm_enter_timewait(cm_id_priv);
            break;
      default:
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            ret = -EINVAL;
            goto out;
      }

      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;
out:
      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

int ib_send_cm_mra(struct ib_cm_id *cm_id,
               u8 service_timeout,
               const void *private_data,
               u8 private_data_len)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      void *data;
      unsigned long flags;
      int ret;

      if (private_data && private_data_len > IB_CM_MRA_PRIVATE_DATA_SIZE)
            return -EINVAL;

      data = cm_copy_private_data(private_data, private_data_len);
      if (IS_ERR(data))
            return PTR_ERR(data);

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch(cm_id_priv->id.state) {
      case IB_CM_REQ_RCVD:
            ret = cm_alloc_msg(cm_id_priv, &msg);
            if (ret)
                  goto error1;

            cm_format_mra((struct cm_mra_msg *) msg->mad, cm_id_priv,
                        CM_MSG_RESPONSE_REQ, service_timeout,
                        private_data, private_data_len);
            ret = ib_post_send_mad(msg, NULL);
            if (ret)
                  goto error2;
            cm_id->state = IB_CM_MRA_REQ_SENT;
            break;
      case IB_CM_REP_RCVD:
            ret = cm_alloc_msg(cm_id_priv, &msg);
            if (ret)
                  goto error1;

            cm_format_mra((struct cm_mra_msg *) msg->mad, cm_id_priv,
                        CM_MSG_RESPONSE_REP, service_timeout,
                        private_data, private_data_len);
            ret = ib_post_send_mad(msg, NULL);
            if (ret)
                  goto error2;
            cm_id->state = IB_CM_MRA_REP_SENT;
            break;
      case IB_CM_ESTABLISHED:
            ret = cm_alloc_msg(cm_id_priv, &msg);
            if (ret)
                  goto error1;

            cm_format_mra((struct cm_mra_msg *) msg->mad, cm_id_priv,
                        CM_MSG_RESPONSE_OTHER, service_timeout,
                        private_data, private_data_len);
            ret = ib_post_send_mad(msg, NULL);
            if (ret)
                  goto error2;
            cm_id->lap_state = IB_CM_MRA_LAP_SENT;
            break;
      default:
            ret = -EINVAL;
            goto error1;
      }
      cm_id_priv->service_timeout = service_timeout;
      cm_set_private_data(cm_id_priv, data, private_data_len);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return 0;

error1:     spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      kfree(data);
      return ret;

error2:     spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      kfree(data);
      cm_free_msg(msg);
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_mra);

static struct cm_id_private * cm_acquire_mraed_id(struct cm_mra_msg *mra_msg)
{
      switch (cm_mra_get_msg_mraed(mra_msg)) {
      case CM_MSG_RESPONSE_REQ:
            return cm_acquire_id(mra_msg->remote_comm_id, 0);
      case CM_MSG_RESPONSE_REP:
      case CM_MSG_RESPONSE_OTHER:
            return cm_acquire_id(mra_msg->remote_comm_id,
                             mra_msg->local_comm_id);
      default:
            return NULL;
      }
}

static int cm_mra_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      struct cm_mra_msg *mra_msg;
      unsigned long flags;
      int timeout, ret;

      mra_msg = (struct cm_mra_msg *)work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_mraed_id(mra_msg);
      if (!cm_id_priv)
            return -EINVAL;

      work->cm_event.private_data = &mra_msg->private_data;
      work->cm_event.param.mra_rcvd.service_timeout =
                              cm_mra_get_service_timeout(mra_msg);
      timeout = cm_convert_to_ms(cm_mra_get_service_timeout(mra_msg)) +
              cm_convert_to_ms(cm_id_priv->av.packet_life_time);

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id_priv->id.state) {
      case IB_CM_REQ_SENT:
            if (cm_mra_get_msg_mraed(mra_msg) != CM_MSG_RESPONSE_REQ ||
                ib_modify_mad(cm_id_priv->av.port->mad_agent,
                          cm_id_priv->msg, timeout))
                  goto out;
            cm_id_priv->id.state = IB_CM_MRA_REQ_RCVD;
            break;
      case IB_CM_REP_SENT:
            if (cm_mra_get_msg_mraed(mra_msg) != CM_MSG_RESPONSE_REP ||
                ib_modify_mad(cm_id_priv->av.port->mad_agent,
                          cm_id_priv->msg, timeout))
                  goto out;
            cm_id_priv->id.state = IB_CM_MRA_REP_RCVD;
            break;
      case IB_CM_ESTABLISHED:
            if (cm_mra_get_msg_mraed(mra_msg) != CM_MSG_RESPONSE_OTHER ||
                cm_id_priv->id.lap_state != IB_CM_LAP_SENT ||
                ib_modify_mad(cm_id_priv->av.port->mad_agent,
                          cm_id_priv->msg, timeout))
                  goto out;
            cm_id_priv->id.lap_state = IB_CM_MRA_LAP_RCVD;
            break;
      default:
            goto out;
      }

      cm_id_priv->msg->context[1] = (void *) (unsigned long)
                              cm_id_priv->id.state;
      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;
out:
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

static void cm_format_lap(struct cm_lap_msg *lap_msg,
                    struct cm_id_private *cm_id_priv,
                    struct ib_sa_path_rec *alternate_path,
                    const void *private_data,
                    u8 private_data_len)
{
      cm_format_mad_hdr(&lap_msg->hdr, CM_LAP_ATTR_ID,
                    cm_form_tid(cm_id_priv, CM_MSG_SEQUENCE_LAP));
      lap_msg->local_comm_id = cm_id_priv->id.local_id;
      lap_msg->remote_comm_id = cm_id_priv->id.remote_id;
      cm_lap_set_remote_qpn(lap_msg, cm_id_priv->remote_qpn);
      /* todo: need remote CM response timeout */
      cm_lap_set_remote_resp_timeout(lap_msg, 0x1F);
      lap_msg->alt_local_lid = alternate_path->slid;
      lap_msg->alt_remote_lid = alternate_path->dlid;
      lap_msg->alt_local_gid = alternate_path->sgid;
      lap_msg->alt_remote_gid = alternate_path->dgid;
      cm_lap_set_flow_label(lap_msg, alternate_path->flow_label);
      cm_lap_set_traffic_class(lap_msg, alternate_path->traffic_class);
      lap_msg->alt_hop_limit = alternate_path->hop_limit;
      cm_lap_set_packet_rate(lap_msg, alternate_path->rate);
      cm_lap_set_sl(lap_msg, alternate_path->sl);
      cm_lap_set_subnet_local(lap_msg, 1); /* local only... */
      cm_lap_set_local_ack_timeout(lap_msg,
            min(31, alternate_path->packet_life_time + 1));

      if (private_data && private_data_len)
            memcpy(lap_msg->private_data, private_data, private_data_len);
}

int ib_send_cm_lap(struct ib_cm_id *cm_id,
               struct ib_sa_path_rec *alternate_path,
               const void *private_data,
               u8 private_data_len)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      unsigned long flags;
      int ret;

      if (private_data && private_data_len > IB_CM_LAP_PRIVATE_DATA_SIZE)
            return -EINVAL;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id->state != IB_CM_ESTABLISHED ||
          cm_id->lap_state != IB_CM_LAP_IDLE) {
            ret = -EINVAL;
            goto out;
      }

      ret = cm_alloc_msg(cm_id_priv, &msg);
      if (ret)
            goto out;

      cm_format_lap((struct cm_lap_msg *) msg->mad, cm_id_priv,
                  alternate_path, private_data, private_data_len);
      msg->timeout_ms = cm_id_priv->timeout_ms;
      msg->context[1] = (void *) (unsigned long) IB_CM_ESTABLISHED;

      ret = ib_post_send_mad(msg, NULL);
      if (ret) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_free_msg(msg);
            return ret;
      }

      cm_id->lap_state = IB_CM_LAP_SENT;
      cm_id_priv->msg = msg;

out:  spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_lap);

static void cm_format_path_from_lap(struct ib_sa_path_rec *path,
                            struct cm_lap_msg *lap_msg)
{
      memset(path, 0, sizeof *path);
      path->dgid = lap_msg->alt_local_gid;
      path->sgid = lap_msg->alt_remote_gid;
      path->dlid = lap_msg->alt_local_lid;
      path->slid = lap_msg->alt_remote_lid;
      path->flow_label = cm_lap_get_flow_label(lap_msg);
      path->hop_limit = lap_msg->alt_hop_limit;
      path->traffic_class = cm_lap_get_traffic_class(lap_msg);
      path->reversible = 1;
      /* pkey is same as in REQ */
      path->sl = cm_lap_get_sl(lap_msg);
      path->mtu_selector = IB_SA_EQ;
      /* mtu is same as in REQ */
      path->rate_selector = IB_SA_EQ;
      path->rate = cm_lap_get_packet_rate(lap_msg);
      path->packet_life_time_selector = IB_SA_EQ;
      path->packet_life_time = cm_lap_get_local_ack_timeout(lap_msg);
      path->packet_life_time -= (path->packet_life_time > 0);
}

static int cm_lap_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      struct cm_lap_msg *lap_msg;
      struct ib_cm_lap_event_param *param;
      struct ib_mad_send_buf *msg = NULL;
      unsigned long flags;
      int ret;

      /* todo: verify LAP request and send reject APR if invalid. */
      lap_msg = (struct cm_lap_msg *)work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_id(lap_msg->remote_comm_id,
                           lap_msg->local_comm_id);
      if (!cm_id_priv)
            return -EINVAL;

      param = &work->cm_event.param.lap_rcvd;
      param->alternate_path = &work->path[0];
      cm_format_path_from_lap(param->alternate_path, lap_msg);
      work->cm_event.private_data = &lap_msg->private_data;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id_priv->id.state != IB_CM_ESTABLISHED)
            goto unlock;

      switch (cm_id_priv->id.lap_state) {
      case IB_CM_LAP_IDLE:
            break;
      case IB_CM_MRA_LAP_SENT:
            if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
                  goto unlock;

            cm_format_mra((struct cm_mra_msg *) msg->mad, cm_id_priv,
                        CM_MSG_RESPONSE_OTHER,
                        cm_id_priv->service_timeout,
                        cm_id_priv->private_data,
                        cm_id_priv->private_data_len);
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);

            if (ib_post_send_mad(msg, NULL))
                  cm_free_msg(msg);
            goto deref;
      default:
            goto unlock;
      }

      cm_id_priv->id.lap_state = IB_CM_LAP_RCVD;
      cm_id_priv->tid = lap_msg->hdr.tid;
      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;

unlock:     spin_unlock_irqrestore(&cm_id_priv->lock, flags);
deref:      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

static void cm_format_apr(struct cm_apr_msg *apr_msg,
                    struct cm_id_private *cm_id_priv,
                    enum ib_cm_apr_status status,
                    void *info,
                    u8 info_length,
                    const void *private_data,
                    u8 private_data_len)
{
      cm_format_mad_hdr(&apr_msg->hdr, CM_APR_ATTR_ID, cm_id_priv->tid);
      apr_msg->local_comm_id = cm_id_priv->id.local_id;
      apr_msg->remote_comm_id = cm_id_priv->id.remote_id;
      apr_msg->ap_status = (u8) status;

      if (info && info_length) {
            apr_msg->info_length = info_length;
            memcpy(apr_msg->info, info, info_length);
      }

      if (private_data && private_data_len)
            memcpy(apr_msg->private_data, private_data, private_data_len);
}

int ib_send_cm_apr(struct ib_cm_id *cm_id,
               enum ib_cm_apr_status status,
               void *info,
               u8 info_length,
               const void *private_data,
               u8 private_data_len)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      unsigned long flags;
      int ret;

      if ((private_data && private_data_len > IB_CM_APR_PRIVATE_DATA_SIZE) ||
          (info && info_length > IB_CM_APR_INFO_LENGTH))
            return -EINVAL;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id->state != IB_CM_ESTABLISHED ||
          (cm_id->lap_state != IB_CM_LAP_RCVD &&
           cm_id->lap_state != IB_CM_MRA_LAP_SENT)) {
            ret = -EINVAL;
            goto out;
      }

      ret = cm_alloc_msg(cm_id_priv, &msg);
      if (ret)
            goto out;

      cm_format_apr((struct cm_apr_msg *) msg->mad, cm_id_priv, status,
                  info, info_length, private_data, private_data_len);
      ret = ib_post_send_mad(msg, NULL);
      if (ret) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_free_msg(msg);
            return ret;
      }

      cm_id->lap_state = IB_CM_LAP_IDLE;
out:  spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_apr);

static int cm_apr_handler(struct cm_work *work)
{
      struct cm_id_private *cm_id_priv;
      struct cm_apr_msg *apr_msg;
      unsigned long flags;
      int ret;

      apr_msg = (struct cm_apr_msg *)work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_id(apr_msg->remote_comm_id,
                           apr_msg->local_comm_id);
      if (!cm_id_priv)
            return -EINVAL; /* Unmatched reply. */

      work->cm_event.param.apr_rcvd.ap_status = apr_msg->ap_status;
      work->cm_event.param.apr_rcvd.apr_info = &apr_msg->info;
      work->cm_event.param.apr_rcvd.info_len = apr_msg->info_length;
      work->cm_event.private_data = &apr_msg->private_data;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id_priv->id.state != IB_CM_ESTABLISHED ||
          (cm_id_priv->id.lap_state != IB_CM_LAP_SENT &&
           cm_id_priv->id.lap_state != IB_CM_MRA_LAP_RCVD)) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            goto out;
      }
      cm_id_priv->id.lap_state = IB_CM_LAP_IDLE;
      ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
      cm_id_priv->msg = NULL;

      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;
out:
      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

static int cm_timewait_handler(struct cm_work *work)
{
      struct cm_timewait_info *timewait_info;
      struct cm_id_private *cm_id_priv;
      unsigned long flags;
      int ret;

      timewait_info = (struct cm_timewait_info *)work;
      cm_cleanup_timewait(timewait_info);

      cm_id_priv = cm_acquire_id(timewait_info->work.local_id,
                           timewait_info->work.remote_id);
      if (!cm_id_priv)
            return -EINVAL;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id_priv->id.state != IB_CM_TIMEWAIT ||
          cm_id_priv->remote_qpn != timewait_info->remote_qpn) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            goto out;
      }
      cm_id_priv->id.state = IB_CM_IDLE;
      ret = atomic_inc_and_test(&cm_id_priv->work_count);
      if (!ret)
            list_add_tail(&work->list, &cm_id_priv->work_list);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret)
            cm_process_work(cm_id_priv, work);
      else
            cm_deref_id(cm_id_priv);
      return 0;
out:
      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

static void cm_format_sidr_req(struct cm_sidr_req_msg *sidr_req_msg,
                         struct cm_id_private *cm_id_priv,
                         struct ib_cm_sidr_req_param *param)
{
      cm_format_mad_hdr(&sidr_req_msg->hdr, CM_SIDR_REQ_ATTR_ID,
                    cm_form_tid(cm_id_priv, CM_MSG_SEQUENCE_SIDR));
      sidr_req_msg->request_id = cm_id_priv->id.local_id;
      sidr_req_msg->pkey = cpu_to_be16(param->path->pkey);
      sidr_req_msg->service_id = param->service_id;

      if (param->private_data && param->private_data_len)
            memcpy(sidr_req_msg->private_data, param->private_data,
                   param->private_data_len);
}

int ib_send_cm_sidr_req(struct ib_cm_id *cm_id,
                  struct ib_cm_sidr_req_param *param)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      unsigned long flags;
      int ret;

      if (!param->path || (param->private_data &&
           param->private_data_len > IB_CM_SIDR_REQ_PRIVATE_DATA_SIZE))
            return -EINVAL;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      ret = cm_init_av_by_path(param->path, &cm_id_priv->av);
      if (ret)
            goto out;

      cm_id->service_id = param->service_id;
      cm_id->service_mask = __constant_cpu_to_be64(~0ULL);
      cm_id_priv->timeout_ms = param->timeout_ms;
      cm_id_priv->max_cm_retries = param->max_cm_retries;
      ret = cm_alloc_msg(cm_id_priv, &msg);
      if (ret)
            goto out;

      cm_format_sidr_req((struct cm_sidr_req_msg *) msg->mad, cm_id_priv,
                     param);
      msg->timeout_ms = cm_id_priv->timeout_ms;
      msg->context[1] = (void *) (unsigned long) IB_CM_SIDR_REQ_SENT;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id->state == IB_CM_IDLE)
            ret = ib_post_send_mad(msg, NULL);
      else
            ret = -EINVAL;

      if (ret) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_free_msg(msg);
            goto out;
      }
      cm_id->state = IB_CM_SIDR_REQ_SENT;
      cm_id_priv->msg = msg;
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
out:
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_sidr_req);

static void cm_format_sidr_req_event(struct cm_work *work,
                             struct ib_cm_id *listen_id)
{
      struct cm_sidr_req_msg *sidr_req_msg;
      struct ib_cm_sidr_req_event_param *param;

      sidr_req_msg = (struct cm_sidr_req_msg *)
                        work->mad_recv_wc->recv_buf.mad;
      param = &work->cm_event.param.sidr_req_rcvd;
      param->pkey = __be16_to_cpu(sidr_req_msg->pkey);
      param->listen_id = listen_id;
      param->port = work->port->port_num;
      work->cm_event.private_data = &sidr_req_msg->private_data;
}

static int cm_sidr_req_handler(struct cm_work *work)
{
      struct ib_cm_id *cm_id;
      struct cm_id_private *cm_id_priv, *cur_cm_id_priv;
      struct cm_sidr_req_msg *sidr_req_msg;
      struct ib_wc *wc;
      unsigned long flags;

      cm_id = ib_create_cm_id(work->port->cm_dev->device, NULL, NULL);
      if (IS_ERR(cm_id))
            return PTR_ERR(cm_id);
      cm_id_priv = container_of(cm_id, struct cm_id_private, id);

      /* Record SGID/SLID and request ID for lookup. */
      sidr_req_msg = (struct cm_sidr_req_msg *)
                        work->mad_recv_wc->recv_buf.mad;
      wc = work->mad_recv_wc->wc;
      cm_id_priv->av.dgid.global.subnet_prefix = cpu_to_be64(wc->slid);
      cm_id_priv->av.dgid.global.interface_id = 0;
      cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
                        work->mad_recv_wc->recv_buf.grh,
                        &cm_id_priv->av);
      cm_id_priv->id.remote_id = sidr_req_msg->request_id;
      cm_id_priv->id.state = IB_CM_SIDR_REQ_RCVD;
      cm_id_priv->tid = sidr_req_msg->hdr.tid;
      atomic_inc(&cm_id_priv->work_count);

      spin_lock_irqsave(&cm.lock, flags);
      cur_cm_id_priv = cm_insert_remote_sidr(cm_id_priv);
      if (cur_cm_id_priv) {
            spin_unlock_irqrestore(&cm.lock, flags);
            goto out; /* Duplicate message. */
      }
      cur_cm_id_priv = cm_find_listen(cm_id->device,
                              sidr_req_msg->service_id,
                              sidr_req_msg->private_data);
      if (!cur_cm_id_priv) {
            rb_erase(&cm_id_priv->sidr_id_node, &cm.remote_sidr_table);
            spin_unlock_irqrestore(&cm.lock, flags);
            /* todo: reply with no match */
            goto out; /* No match. */
      }
      atomic_inc(&cur_cm_id_priv->refcount);
      spin_unlock_irqrestore(&cm.lock, flags);

      cm_id_priv->id.cm_handler = cur_cm_id_priv->id.cm_handler;
      cm_id_priv->id.context = cur_cm_id_priv->id.context;
      cm_id_priv->id.service_id = sidr_req_msg->service_id;
      cm_id_priv->id.service_mask = __constant_cpu_to_be64(~0ULL);

      cm_format_sidr_req_event(work, &cur_cm_id_priv->id);
      cm_process_work(cm_id_priv, work);
      cm_deref_id(cur_cm_id_priv);
      return 0;
out:
      ib_destroy_cm_id(&cm_id_priv->id);
      return -EINVAL;
}

static void cm_format_sidr_rep(struct cm_sidr_rep_msg *sidr_rep_msg,
                         struct cm_id_private *cm_id_priv,
                         struct ib_cm_sidr_rep_param *param)
{
      cm_format_mad_hdr(&sidr_rep_msg->hdr, CM_SIDR_REP_ATTR_ID,
                    cm_id_priv->tid);
      sidr_rep_msg->request_id = cm_id_priv->id.remote_id;
      sidr_rep_msg->status = param->status;
      cm_sidr_rep_set_qpn(sidr_rep_msg, cpu_to_be32(param->qp_num));
      sidr_rep_msg->service_id = cm_id_priv->id.service_id;
      sidr_rep_msg->qkey = cpu_to_be32(param->qkey);

      if (param->info && param->info_length)
            memcpy(sidr_rep_msg->info, param->info, param->info_length);

      if (param->private_data && param->private_data_len)
            memcpy(sidr_rep_msg->private_data, param->private_data,
                   param->private_data_len);
}

int ib_send_cm_sidr_rep(struct ib_cm_id *cm_id,
                  struct ib_cm_sidr_rep_param *param)
{
      struct cm_id_private *cm_id_priv;
      struct ib_mad_send_buf *msg;
      unsigned long flags;
      int ret;

      if ((param->info && param->info_length > IB_CM_SIDR_REP_INFO_LENGTH) ||
          (param->private_data &&
           param->private_data_len > IB_CM_SIDR_REP_PRIVATE_DATA_SIZE))
            return -EINVAL;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id->state != IB_CM_SIDR_REQ_RCVD) {
            ret = -EINVAL;
            goto error;
      }

      ret = cm_alloc_msg(cm_id_priv, &msg);
      if (ret)
            goto error;

      cm_format_sidr_rep((struct cm_sidr_rep_msg *) msg->mad, cm_id_priv,
                     param);
      ret = ib_post_send_mad(msg, NULL);
      if (ret) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            cm_free_msg(msg);
            return ret;
      }
      cm_id->state = IB_CM_IDLE;
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      spin_lock_irqsave(&cm.lock, flags);
      rb_erase(&cm_id_priv->sidr_id_node, &cm.remote_sidr_table);
      spin_unlock_irqrestore(&cm.lock, flags);
      return 0;

error:      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}
EXPORT_SYMBOL(ib_send_cm_sidr_rep);

static void cm_format_sidr_rep_event(struct cm_work *work)
{
      struct cm_sidr_rep_msg *sidr_rep_msg;
      struct ib_cm_sidr_rep_event_param *param;

      sidr_rep_msg = (struct cm_sidr_rep_msg *)
                        work->mad_recv_wc->recv_buf.mad;
      param = &work->cm_event.param.sidr_rep_rcvd;
      param->status = sidr_rep_msg->status;
      param->qkey = be32_to_cpu(sidr_rep_msg->qkey);
      param->qpn = be32_to_cpu(cm_sidr_rep_get_qpn(sidr_rep_msg));
      param->info = &sidr_rep_msg->info;
      param->info_len = sidr_rep_msg->info_length;
      work->cm_event.private_data = &sidr_rep_msg->private_data;
}

static int cm_sidr_rep_handler(struct cm_work *work)
{
      struct cm_sidr_rep_msg *sidr_rep_msg;
      struct cm_id_private *cm_id_priv;
      unsigned long flags;

      sidr_rep_msg = (struct cm_sidr_rep_msg *)
                        work->mad_recv_wc->recv_buf.mad;
      cm_id_priv = cm_acquire_id(sidr_rep_msg->request_id, 0);
      if (!cm_id_priv)
            return -EINVAL; /* Unmatched reply. */

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      if (cm_id_priv->id.state != IB_CM_SIDR_REQ_SENT) {
            spin_unlock_irqrestore(&cm_id_priv->lock, flags);
            goto out;
      }
      cm_id_priv->id.state = IB_CM_IDLE;
      ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      cm_format_sidr_rep_event(work);
      cm_process_work(cm_id_priv, work);
      return 0;
out:
      cm_deref_id(cm_id_priv);
      return -EINVAL;
}

static void cm_process_send_error(struct ib_mad_send_buf *msg,
                          enum ib_wc_status wc_status)
{
      struct cm_id_private *cm_id_priv;
      struct ib_cm_event cm_event;
      enum ib_cm_state state;
      unsigned long flags;
      int ret;

      memset(&cm_event, 0, sizeof cm_event);
      cm_id_priv = msg->context[0];

      /* Discard old sends or ones without a response. */
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      state = (enum ib_cm_state) (unsigned long) msg->context[1];
      if (msg != cm_id_priv->msg || state != cm_id_priv->id.state)
            goto discard;

      switch (state) {
      case IB_CM_REQ_SENT:
      case IB_CM_MRA_REQ_RCVD:
            cm_reset_to_idle(cm_id_priv);
            cm_event.event = IB_CM_REQ_ERROR;
            break;
      case IB_CM_REP_SENT:
      case IB_CM_MRA_REP_RCVD:
            cm_reset_to_idle(cm_id_priv);
            cm_event.event = IB_CM_REP_ERROR;
            break;
      case IB_CM_DREQ_SENT:
            cm_enter_timewait(cm_id_priv);
            cm_event.event = IB_CM_DREQ_ERROR;
            break;
      case IB_CM_SIDR_REQ_SENT:
            cm_id_priv->id.state = IB_CM_IDLE;
            cm_event.event = IB_CM_SIDR_REQ_ERROR;
            break;
      default:
            goto discard;
      }
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      cm_event.param.send_status = wc_status;

      /* No other events can occur on the cm_id at this point. */
      ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, &cm_event);
      cm_free_msg(msg);
      if (ret)
            ib_destroy_cm_id(&cm_id_priv->id);
      return;
discard:
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      cm_free_msg(msg);
}

static void cm_send_handler(struct ib_mad_agent *mad_agent,
                      struct ib_mad_send_wc *mad_send_wc)
{
      struct ib_mad_send_buf *msg = mad_send_wc->send_buf;

      switch (mad_send_wc->status) {
      case IB_WC_SUCCESS:
      case IB_WC_WR_FLUSH_ERR:
            cm_free_msg(msg);
            break;
      default:
            if (msg->context[0] && msg->context[1])
                  cm_process_send_error(msg, mad_send_wc->status);
            else
                  cm_free_msg(msg);
            break;
      }
}

static void cm_work_handler(void *data)
{
      struct cm_work *work = data;
      int ret;

      switch (work->cm_event.event) {
      case IB_CM_REQ_RECEIVED:
            ret = cm_req_handler(work);
            break;
      case IB_CM_MRA_RECEIVED:
            ret = cm_mra_handler(work);
            break;
      case IB_CM_REJ_RECEIVED:
            ret = cm_rej_handler(work);
            break;
      case IB_CM_REP_RECEIVED:
            ret = cm_rep_handler(work);
            break;
      case IB_CM_RTU_RECEIVED:
            ret = cm_rtu_handler(work);
            break;
      case IB_CM_USER_ESTABLISHED:
            ret = cm_establish_handler(work);
            break;
      case IB_CM_DREQ_RECEIVED:
            ret = cm_dreq_handler(work);
            break;
      case IB_CM_DREP_RECEIVED:
            ret = cm_drep_handler(work);
            break;
      case IB_CM_SIDR_REQ_RECEIVED:
            ret = cm_sidr_req_handler(work);
            break;
      case IB_CM_SIDR_REP_RECEIVED:
            ret = cm_sidr_rep_handler(work);
            break;
      case IB_CM_LAP_RECEIVED:
            ret = cm_lap_handler(work);
            break;
      case IB_CM_APR_RECEIVED:
            ret = cm_apr_handler(work);
            break;
      case IB_CM_TIMEWAIT_EXIT:
            ret = cm_timewait_handler(work);
            break;
      default:
            ret = -EINVAL;
            break;
      }
      if (ret)
            cm_free_work(work);
}

int ib_cm_establish(struct ib_cm_id *cm_id)
{
      struct cm_id_private *cm_id_priv;
      struct cm_work *work;
      unsigned long flags;
      int ret = 0;

      work = kmalloc(sizeof *work, GFP_ATOMIC);
      if (!work)
            return -ENOMEM;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id->state)
      {
      case IB_CM_REP_SENT:
      case IB_CM_MRA_REP_RCVD:
            cm_id->state = IB_CM_ESTABLISHED;
            break;
      case IB_CM_ESTABLISHED:
            ret = -EISCONN;
            break;
      default:
            ret = -EINVAL;
            break;
      }
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);

      if (ret) {
            kfree(work);
            goto out;
      }

      /*
       * The CM worker thread may try to destroy the cm_id before it
       * can execute this work item.  To prevent potential deadlock,
       * we need to find the cm_id once we're in the context of the
       * worker thread, rather than holding a reference on it.
       */
      INIT_WORK(&work->work, cm_work_handler, work);
      work->local_id = cm_id->local_id;
      work->remote_id = cm_id->remote_id;
      work->mad_recv_wc = NULL;
      work->cm_event.event = IB_CM_USER_ESTABLISHED;
      queue_work(cm.wq, &work->work);
out:
      return ret;
}
EXPORT_SYMBOL(ib_cm_establish);

static void cm_recv_handler(struct ib_mad_agent *mad_agent,
                      struct ib_mad_recv_wc *mad_recv_wc)
{
      struct cm_work *work;
      enum ib_cm_event_type event;
      int paths = 0;

      switch (mad_recv_wc->recv_buf.mad->mad_hdr.attr_id) {
      case CM_REQ_ATTR_ID:
            paths = 1 + (((struct cm_req_msg *) mad_recv_wc->recv_buf.mad)->
                                        alt_local_lid != 0);
            event = IB_CM_REQ_RECEIVED;
            break;
      case CM_MRA_ATTR_ID:
            event = IB_CM_MRA_RECEIVED;
            break;
      case CM_REJ_ATTR_ID:
            event = IB_CM_REJ_RECEIVED;
            break;
      case CM_REP_ATTR_ID:
            event = IB_CM_REP_RECEIVED;
            break;
      case CM_RTU_ATTR_ID:
            event = IB_CM_RTU_RECEIVED;
            break;
      case CM_DREQ_ATTR_ID:
            event = IB_CM_DREQ_RECEIVED;
            break;
      case CM_DREP_ATTR_ID:
            event = IB_CM_DREP_RECEIVED;
            break;
      case CM_SIDR_REQ_ATTR_ID:
            event = IB_CM_SIDR_REQ_RECEIVED;
            break;
      case CM_SIDR_REP_ATTR_ID:
            event = IB_CM_SIDR_REP_RECEIVED;
            break;
      case CM_LAP_ATTR_ID:
            paths = 1;
            event = IB_CM_LAP_RECEIVED;
            break;
      case CM_APR_ATTR_ID:
            event = IB_CM_APR_RECEIVED;
            break;
      default:
            ib_free_recv_mad(mad_recv_wc);
            return;
      }

      work = kmalloc(sizeof *work + sizeof(struct ib_sa_path_rec) * paths,
                   GFP_KERNEL);
      if (!work) {
            ib_free_recv_mad(mad_recv_wc);
            return;
      }

      INIT_WORK(&work->work, cm_work_handler, work);
      work->cm_event.event = event;
      work->mad_recv_wc = mad_recv_wc;
      work->port = (struct cm_port *)mad_agent->context;
      queue_work(cm.wq, &work->work);
}

static int cm_init_qp_init_attr(struct cm_id_private *cm_id_priv,
                        struct ib_qp_attr *qp_attr,
                        int *qp_attr_mask)
{
      unsigned long flags;
      int ret;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id_priv->id.state) {
      case IB_CM_REQ_SENT:
      case IB_CM_MRA_REQ_RCVD:
      case IB_CM_REQ_RCVD:
      case IB_CM_MRA_REQ_SENT:
      case IB_CM_REP_RCVD:
      case IB_CM_MRA_REP_SENT:
      case IB_CM_REP_SENT:
      case IB_CM_MRA_REP_RCVD:
      case IB_CM_ESTABLISHED:
            *qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS |
                        IB_QP_PKEY_INDEX | IB_QP_PORT;
            qp_attr->qp_access_flags = IB_ACCESS_LOCAL_WRITE |
                                 IB_ACCESS_REMOTE_WRITE;
            if (cm_id_priv->responder_resources)
                  qp_attr->qp_access_flags |= IB_ACCESS_REMOTE_READ;
            qp_attr->pkey_index = cm_id_priv->av.pkey_index;
            qp_attr->port_num = cm_id_priv->av.port->port_num;
            ret = 0;
            break;
      default:
            ret = -EINVAL;
            break;
      }
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}

static int cm_init_qp_rtr_attr(struct cm_id_private *cm_id_priv,
                         struct ib_qp_attr *qp_attr,
                         int *qp_attr_mask)
{
      unsigned long flags;
      int ret;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id_priv->id.state) {
      case IB_CM_REQ_RCVD:
      case IB_CM_MRA_REQ_SENT:
      case IB_CM_REP_RCVD:
      case IB_CM_MRA_REP_SENT:
      case IB_CM_REP_SENT:
      case IB_CM_MRA_REP_RCVD:
      case IB_CM_ESTABLISHED:
            *qp_attr_mask = IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU |
                        IB_QP_DEST_QPN | IB_QP_RQ_PSN;
            qp_attr->ah_attr = cm_id_priv->av.ah_attr;
            qp_attr->path_mtu = cm_id_priv->path_mtu;
            qp_attr->dest_qp_num = be32_to_cpu(cm_id_priv->remote_qpn);
            qp_attr->rq_psn = be32_to_cpu(cm_id_priv->rq_psn);
            if (cm_id_priv->qp_type == IB_QPT_RC) {
                  *qp_attr_mask |= IB_QP_MAX_DEST_RD_ATOMIC |
                               IB_QP_MIN_RNR_TIMER;
                  qp_attr->max_dest_rd_atomic =
                              cm_id_priv->responder_resources;
                  qp_attr->min_rnr_timer = 0;
            }
            if (cm_id_priv->alt_av.ah_attr.dlid) {
                  *qp_attr_mask |= IB_QP_ALT_PATH;
                  qp_attr->alt_port_num = cm_id_priv->alt_av.port->port_num;
                  qp_attr->alt_ah_attr = cm_id_priv->alt_av.ah_attr;
            }
            ret = 0;
            break;
      default:
            ret = -EINVAL;
            break;
      }
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}

static int cm_init_qp_rts_attr(struct cm_id_private *cm_id_priv,
                         struct ib_qp_attr *qp_attr,
                         int *qp_attr_mask)
{
      unsigned long flags;
      int ret;

      spin_lock_irqsave(&cm_id_priv->lock, flags);
      switch (cm_id_priv->id.state) {
      case IB_CM_REP_RCVD:
      case IB_CM_MRA_REP_SENT:
      case IB_CM_REP_SENT:
      case IB_CM_MRA_REP_RCVD:
      case IB_CM_ESTABLISHED:
            *qp_attr_mask = IB_QP_STATE | IB_QP_SQ_PSN;
            qp_attr->sq_psn = be32_to_cpu(cm_id_priv->sq_psn);
            if (cm_id_priv->qp_type == IB_QPT_RC) {
                  *qp_attr_mask |= IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
                               IB_QP_RNR_RETRY |
                               IB_QP_MAX_QP_RD_ATOMIC;
                  qp_attr->timeout = cm_id_priv->local_ack_timeout;
                  qp_attr->retry_cnt = cm_id_priv->retry_count;
                  qp_attr->rnr_retry = cm_id_priv->rnr_retry_count;
                  qp_attr->max_rd_atomic = cm_id_priv->initiator_depth;
            }
            if (cm_id_priv->alt_av.ah_attr.dlid) {
                  *qp_attr_mask |= IB_QP_PATH_MIG_STATE;
                  qp_attr->path_mig_state = IB_MIG_REARM;
            }
            ret = 0;
            break;
      default:
            ret = -EINVAL;
            break;
      }
      spin_unlock_irqrestore(&cm_id_priv->lock, flags);
      return ret;
}

int ib_cm_init_qp_attr(struct ib_cm_id *cm_id,
                   struct ib_qp_attr *qp_attr,
                   int *qp_attr_mask)
{
      struct cm_id_private *cm_id_priv;
      int ret;

      cm_id_priv = container_of(cm_id, struct cm_id_private, id);
      switch (qp_attr->qp_state) {
      case IB_QPS_INIT:
            ret = cm_init_qp_init_attr(cm_id_priv, qp_attr, qp_attr_mask);
            break;
      case IB_QPS_RTR:
            ret = cm_init_qp_rtr_attr(cm_id_priv, qp_attr, qp_attr_mask);
            break;
      case IB_QPS_RTS:
            ret = cm_init_qp_rts_attr(cm_id_priv, qp_attr, qp_attr_mask);
            break;
      default:
            ret = -EINVAL;
            break;
      }
      return ret;
}
EXPORT_SYMBOL(ib_cm_init_qp_attr);

static void cm_add_one(struct ib_device *device)
{
      struct cm_device *cm_dev;
      struct cm_port *port;
      struct ib_mad_reg_req reg_req = {
            .mgmt_class = IB_MGMT_CLASS_CM,
            .mgmt_class_version = IB_CM_CLASS_VERSION
      };
      struct ib_port_modify port_modify = {
            .set_port_cap_mask = IB_PORT_CM_SUP
      };
      unsigned long flags;
      int ret;
      u8 i;

      cm_dev = kmalloc(sizeof(*cm_dev) + sizeof(*port) *
                   device->phys_port_cnt, GFP_KERNEL);
      if (!cm_dev)
            return;

      cm_dev->device = device;
      cm_dev->ca_guid = device->node_guid;

      set_bit(IB_MGMT_METHOD_SEND, reg_req.method_mask);
      for (i = 1; i <= device->phys_port_cnt; i++) {
            port = &cm_dev->port[i-1];
            port->cm_dev = cm_dev;
            port->port_num = i;
            port->mad_agent = ib_register_mad_agent(device, i,
                                          IB_QPT_GSI,
                                          &reg_req,
                                          0,
                                          cm_send_handler,
                                          cm_recv_handler,
                                          port);
            if (IS_ERR(port->mad_agent))
                  goto error1;

            ret = ib_modify_port(device, i, 0, &port_modify);
            if (ret)
                  goto error2;
      }
      ib_set_client_data(device, &cm_client, cm_dev);

      write_lock_irqsave(&cm.device_lock, flags);
      list_add_tail(&cm_dev->list, &cm.device_list);
      write_unlock_irqrestore(&cm.device_lock, flags);
      return;

error2:
      ib_unregister_mad_agent(port->mad_agent);
error1:
      port_modify.set_port_cap_mask = 0;
      port_modify.clr_port_cap_mask = IB_PORT_CM_SUP;
      while (--i) {
            port = &cm_dev->port[i-1];
            ib_modify_port(device, port->port_num, 0, &port_modify);
            ib_unregister_mad_agent(port->mad_agent);
      }
      kfree(cm_dev);
}

static void cm_remove_one(struct ib_device *device)
{
      struct cm_device *cm_dev;
      struct cm_port *port;
      struct ib_port_modify port_modify = {
            .clr_port_cap_mask = IB_PORT_CM_SUP
      };
      unsigned long flags;
      int i;

      cm_dev = ib_get_client_data(device, &cm_client);
      if (!cm_dev)
            return;

      write_lock_irqsave(&cm.device_lock, flags);
      list_del(&cm_dev->list);
      write_unlock_irqrestore(&cm.device_lock, flags);

      for (i = 1; i <= device->phys_port_cnt; i++) {
            port = &cm_dev->port[i-1];
            ib_modify_port(device, port->port_num, 0, &port_modify);
            ib_unregister_mad_agent(port->mad_agent);
      }
      kfree(cm_dev);
}

static int __init ib_cm_init(void)
{
      int ret;

      memset(&cm, 0, sizeof cm);
      INIT_LIST_HEAD(&cm.device_list);
      rwlock_init(&cm.device_lock);
      spin_lock_init(&cm.lock);
      cm.listen_service_table = RB_ROOT;
      cm.listen_service_id = __constant_be64_to_cpu(IB_CM_ASSIGN_SERVICE_ID);
      cm.remote_id_table = RB_ROOT;
      cm.remote_qp_table = RB_ROOT;
      cm.remote_sidr_table = RB_ROOT;
      idr_init(&cm.local_id_table);
      idr_pre_get(&cm.local_id_table, GFP_KERNEL);

      cm.wq = create_workqueue("ib_cm");
      if (!cm.wq)
            return -ENOMEM;

      ret = ib_register_client(&cm_client);
      if (ret)
            goto error;

      return 0;
error:
      destroy_workqueue(cm.wq);
      return ret;
}

static void __exit ib_cm_cleanup(void)
{
      destroy_workqueue(cm.wq);
      ib_unregister_client(&cm_client);
      idr_destroy(&cm.local_id_table);
}

module_init(ib_cm_init);
module_exit(ib_cm_cleanup);


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