FreeBSD/Linux Kernel Cross Reference
sys/ofed/drivers/infiniband/core/ib_cm.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0
      *
      * Copyright (c) 2004-2007 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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <linux/completion.h>
    #include <linux/dma-mapping.h>
    #include <linux/device.h>
    #include <linux/module.h>
    #include <linux/err.h>
    #include <linux/idr.h>
    #include <linux/interrupt.h>
    #include <linux/random.h>
    #include <linux/rbtree.h>
    #include <linux/spinlock.h>
    #include <linux/slab.h>
    #include <linux/sysfs.h>
    #include <linux/workqueue.h>
    #include <linux/kdev_t.h>
    #include <linux/etherdevice.h>
    
    #include <asm/atomic-long.h>
    
    #include <rdma/ib_addr.h>
    #include <rdma/ib_cache.h>
    #include <rdma/ib_cm.h>
    #include "cm_msgs.h"
    #include "core_priv.h"
    
    MODULE_AUTHOR("Sean Hefty");
    MODULE_DESCRIPTION("InfiniBand CM");
    MODULE_LICENSE("Dual BSD/GPL");
    
    static const char * const ibcm_rej_reason_strs[] = {
            [IB_CM_REJ_NO_QP]                       = "no QP",
            [IB_CM_REJ_NO_EEC]                      = "no EEC",
            [IB_CM_REJ_NO_RESOURCES]                = "no resources",
            [IB_CM_REJ_TIMEOUT]                     = "timeout",
            [IB_CM_REJ_UNSUPPORTED]                 = "unsupported",
            [IB_CM_REJ_INVALID_COMM_ID]             = "invalid comm ID",
            [IB_CM_REJ_INVALID_COMM_INSTANCE]       = "invalid comm instance",
            [IB_CM_REJ_INVALID_SERVICE_ID]          = "invalid service ID",
            [IB_CM_REJ_INVALID_TRANSPORT_TYPE]      = "invalid transport type",
            [IB_CM_REJ_STALE_CONN]                  = "stale conn",
            [IB_CM_REJ_RDC_NOT_EXIST]               = "RDC not exist",
            [IB_CM_REJ_INVALID_GID]                 = "invalid GID",
            [IB_CM_REJ_INVALID_LID]                 = "invalid LID",
            [IB_CM_REJ_INVALID_SL]                  = "invalid SL",
            [IB_CM_REJ_INVALID_TRAFFIC_CLASS]       = "invalid traffic class",
            [IB_CM_REJ_INVALID_HOP_LIMIT]           = "invalid hop limit",
            [IB_CM_REJ_INVALID_PACKET_RATE]         = "invalid packet rate",
            [IB_CM_REJ_INVALID_ALT_GID]             = "invalid alt GID",
            [IB_CM_REJ_INVALID_ALT_LID]             = "invalid alt LID",
            [IB_CM_REJ_INVALID_ALT_SL]              = "invalid alt SL",
            [IB_CM_REJ_INVALID_ALT_TRAFFIC_CLASS]   = "invalid alt traffic class",
            [IB_CM_REJ_INVALID_ALT_HOP_LIMIT]       = "invalid alt hop limit",
            [IB_CM_REJ_INVALID_ALT_PACKET_RATE]     = "invalid alt packet rate",
            [IB_CM_REJ_PORT_CM_REDIRECT]            = "port CM redirect",
            [IB_CM_REJ_PORT_REDIRECT]               = "port redirect",
            [IB_CM_REJ_INVALID_MTU]                 = "invalid MTU",
            [IB_CM_REJ_INSUFFICIENT_RESP_RESOURCES] = "insufficient resp resources",
            [IB_CM_REJ_CONSUMER_DEFINED]            = "consumer defined",
            [IB_CM_REJ_INVALID_RNR_RETRY]           = "invalid RNR retry",
            [IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID]     = "duplicate local comm ID",
           [IB_CM_REJ_INVALID_CLASS_VERSION]       = "invalid class version",
           [IB_CM_REJ_INVALID_FLOW_LABEL]          = "invalid flow label",
           [IB_CM_REJ_INVALID_ALT_FLOW_LABEL]      = "invalid alt flow label",
   };
   
   const char *__attribute_const__ ibcm_reject_msg(int reason)
   {
           size_t index = reason;
   
           if (index < ARRAY_SIZE(ibcm_rej_reason_strs) &&
               ibcm_rej_reason_strs[index])
                   return ibcm_rej_reason_strs[index];
           else
                   return "unrecognized reason";
   }
   EXPORT_SYMBOL(ibcm_reject_msg);
   
   static void cm_add_one(struct ib_device *device);
   static void cm_remove_one(struct ib_device *device, void *client_data);
   
   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;
           __be32 random_id_operand;
           struct list_head timewait_list;
           struct workqueue_struct *wq;
           /* Sync on cm change port state */
           spinlock_t state_lock;
   } cm;
   
   /* Counter indexes ordered by attribute ID */
   enum {
           CM_REQ_COUNTER,
           CM_MRA_COUNTER,
           CM_REJ_COUNTER,
           CM_REP_COUNTER,
           CM_RTU_COUNTER,
           CM_DREQ_COUNTER,
           CM_DREP_COUNTER,
           CM_SIDR_REQ_COUNTER,
           CM_SIDR_REP_COUNTER,
           CM_LAP_COUNTER,
           CM_APR_COUNTER,
           CM_ATTR_COUNT,
           CM_ATTR_ID_OFFSET = 0x0010,
   };
   
   enum {
           CM_XMIT,
           CM_XMIT_RETRIES,
           CM_RECV,
           CM_RECV_DUPLICATES,
           CM_COUNTER_GROUPS
   };
   
   static char const counter_group_names[CM_COUNTER_GROUPS]
                                        [sizeof("cm_rx_duplicates")] = {
           "cm_tx_msgs", "cm_tx_retries",
           "cm_rx_msgs", "cm_rx_duplicates"
   };
   
   struct cm_counter_group {
           struct kobject obj;
           atomic_long_t counter[CM_ATTR_COUNT];
   };
   
   struct cm_counter_attribute {
           struct attribute attr;
           int index;
   };
   
   #define CM_COUNTER_ATTR(_name, _index) \
   struct cm_counter_attribute cm_##_name##_counter_attr = { \
           .attr = { .name = __stringify(_name), .mode = 0444 }, \
           .index = _index \
   }
   
   static CM_COUNTER_ATTR(req, CM_REQ_COUNTER);
   static CM_COUNTER_ATTR(mra, CM_MRA_COUNTER);
   static CM_COUNTER_ATTR(rej, CM_REJ_COUNTER);
   static CM_COUNTER_ATTR(rep, CM_REP_COUNTER);
   static CM_COUNTER_ATTR(rtu, CM_RTU_COUNTER);
   static CM_COUNTER_ATTR(dreq, CM_DREQ_COUNTER);
   static CM_COUNTER_ATTR(drep, CM_DREP_COUNTER);
   static CM_COUNTER_ATTR(sidr_req, CM_SIDR_REQ_COUNTER);
   static CM_COUNTER_ATTR(sidr_rep, CM_SIDR_REP_COUNTER);
   static CM_COUNTER_ATTR(lap, CM_LAP_COUNTER);
   static CM_COUNTER_ATTR(apr, CM_APR_COUNTER);
   
   static struct attribute *cm_counter_default_attrs[] = {
           &cm_req_counter_attr.attr,
           &cm_mra_counter_attr.attr,
           &cm_rej_counter_attr.attr,
           &cm_rep_counter_attr.attr,
           &cm_rtu_counter_attr.attr,
           &cm_dreq_counter_attr.attr,
           &cm_drep_counter_attr.attr,
           &cm_sidr_req_counter_attr.attr,
           &cm_sidr_rep_counter_attr.attr,
           &cm_lap_counter_attr.attr,
           &cm_apr_counter_attr.attr,
           NULL
   };
   
   struct cm_port {
           struct cm_device *cm_dev;
           struct ib_mad_agent *mad_agent;
           struct kobject port_obj;
           u8 port_num;
           struct list_head cm_priv_prim_list;
           struct list_head cm_priv_altr_list;
           struct cm_counter_group counter_group[CM_COUNTER_GROUPS];
   };
   
   struct cm_device {
           struct list_head list;
           struct ib_device *ib_device;
           u8 ack_delay;
           int going_down;
           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 timeout;
   };
   
   struct cm_work {
           struct delayed_work 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 list_head list;
           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;
           /* Number of clients sharing this ib_cm_id. Only valid for listeners.
            * Protected by the cm.lock spinlock. */
           int listen_sharecount;
   
           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;
   
           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;
           __be16 pkey;
           u8 private_data_len;
           u8 max_cm_retries;
           u8 peer_to_peer;
           u8 responder_resources;
           u8 initiator_depth;
           u8 retry_count;
           u8 rnr_retry_count;
           u8 service_timeout;
           u8 target_ack_delay;
   
           struct list_head prim_list;
           struct list_head altr_list;
           /* Indicates that the send port mad is registered and av is set */
           int prim_send_port_not_ready;
           int altr_send_port_not_ready;
   
           struct list_head work_list;
           atomic_t work_count;
   };
   
   static void cm_work_handler(struct work_struct *work);
   
   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;
           struct cm_av *av;
           unsigned long flags, flags2;
           int ret = 0;
   
           /* don't let the port to be released till the agent is down */
           spin_lock_irqsave(&cm.state_lock, flags2);
           spin_lock_irqsave(&cm.lock, flags);
           if (!cm_id_priv->prim_send_port_not_ready)
                   av = &cm_id_priv->av;
           else if (!cm_id_priv->altr_send_port_not_ready &&
                    (cm_id_priv->alt_av.port))
                   av = &cm_id_priv->alt_av;
           else {
                   pr_info("%s: not valid CM id\n", __func__);
                   ret = -ENODEV;
                   spin_unlock_irqrestore(&cm.lock, flags);
                   goto out;
           }
           spin_unlock_irqrestore(&cm.lock, flags);
           /* Make sure the port haven't released the mad yet */
           mad_agent = cm_id_priv->av.port->mad_agent;
           if (!mad_agent) {
                   pr_info("%s: not a valid MAD agent\n", __func__);
                   ret = -ENODEV;
                   goto out;
           }
           ah = ib_create_ah(mad_agent->qp->pd, &av->ah_attr, 0);
           if (IS_ERR(ah)) {
                   ret = PTR_ERR(ah);
                   goto out;
           }
   
           m = ib_create_send_mad(mad_agent, cm_id_priv->id.remote_cm_qpn,
                                  av->pkey_index,
                                  0, IB_MGMT_MAD_HDR, IB_MGMT_MAD_DATA,
                                  GFP_ATOMIC,
                                  IB_MGMT_BASE_VERSION);
           if (IS_ERR(m)) {
                   ib_destroy_ah(ah, 0);
                   ret = PTR_ERR(m);
                   goto out;
           }
   
           /* 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;
   
   out:
           spin_unlock_irqrestore(&cm.state_lock, flags2);
           return ret;
   }
   
   static struct ib_mad_send_buf *cm_alloc_response_msg_no_ah(struct cm_port *port,
                                                              struct ib_mad_recv_wc *mad_recv_wc)
   {
           return 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,
                                     IB_MGMT_BASE_VERSION);
   }
   
   static int cm_create_response_msg_ah(struct cm_port *port,
                                        struct ib_mad_recv_wc *mad_recv_wc,
                                        struct ib_mad_send_buf *msg)
   {
           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);
   
           msg->ah = ah;
           return 0;
   }
   
   static void cm_free_msg(struct ib_mad_send_buf *msg)
   {
           if (msg->ah)
                   ib_destroy_ah(msg->ah, 0);
           if (msg->context[0])
                   cm_deref_id(msg->context[0]);
           ib_free_send_mad(msg);
   }
   
   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;
           int ret;
   
           m = cm_alloc_response_msg_no_ah(port, mad_recv_wc);
           if (IS_ERR(m))
                   return PTR_ERR(m);
   
           ret = cm_create_response_msg_ah(port, mad_recv_wc, m);
           if (ret) {
                   cm_free_msg(m);
                   return ret;
           }
   
           *msg = m;
           return 0;
   }
   
   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 = kmemdup(private_data, private_data_len, GFP_KERNEL);
           if (!data)
                   return ERR_PTR(-ENOMEM);
   
           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 int cm_init_av_for_lap(struct cm_port *port, struct ib_wc *wc,
                                 struct ib_grh *grh, struct cm_av *av)
   {
           struct ib_ah_attr new_ah_attr;
           int ret;
   
           av->port = port;
           av->pkey_index = wc->pkey_index;
   
           /*
            * av->ah_attr might be initialized based on past wc during incoming
            * connect request or while sending out connect request. So initialize
            * a new ah_attr on stack. If initialization fails, old ah_attr is
            * used for sending any responses. If initialization is successful,
            * than new ah_attr is used by overwriting old one.
            */
           ret = ib_init_ah_from_wc(port->cm_dev->ib_device,
                                    port->port_num, wc,
                                    grh, &new_ah_attr);
           if (ret)
                   return ret;
   
           memcpy(&av->ah_attr, &new_ah_attr, sizeof(new_ah_attr));
           return 0;
   }
   
   static int 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;
           return ib_init_ah_from_wc(port->cm_dev->ib_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_id_private *cm_id_priv)
   {
           struct cm_device *cm_dev;
           struct cm_port *port = NULL;
           unsigned long flags;
           int ret;
           u8 p;
           struct ifnet *ndev = ib_get_ndev_from_path(path);
   
           read_lock_irqsave(&cm.device_lock, flags);
           list_for_each_entry(cm_dev, &cm.device_list, list) {
                   if (!ib_find_cached_gid(cm_dev->ib_device, &path->sgid,
                                           path->gid_type, ndev, &p, NULL)) {
                           port = cm_dev->port[p-1];
                           break;
                   }
           }
           read_unlock_irqrestore(&cm.device_lock, flags);
   
           if (ndev)
                   dev_put(ndev);
   
           if (!port)
                   return -EINVAL;
   
           ret = ib_find_cached_pkey(cm_dev->ib_device, port->port_num,
                                     be16_to_cpu(path->pkey), &av->pkey_index);
           if (ret)
                   return ret;
   
           av->port = port;
           ret = ib_init_ah_from_path(cm_dev->ib_device, port->port_num,
                                      path, &av->ah_attr);
           if (ret)
                   return ret;
   
           av->timeout = path->packet_life_time + 1;
   
           spin_lock_irqsave(&cm.lock, flags);
           if (&cm_id_priv->av == av)
                   list_add_tail(&cm_id_priv->prim_list, &port->cm_priv_prim_list);
           else if (&cm_id_priv->alt_av == av)
                   list_add_tail(&cm_id_priv->altr_list, &port->cm_priv_altr_list);
           else
                   ret = -EINVAL;
   
           spin_unlock_irqrestore(&cm.lock, flags);
   
           return ret;
   }
   
   static int cm_alloc_id(struct cm_id_private *cm_id_priv)
   {
           unsigned long flags;
           int id;
   
           idr_preload(GFP_KERNEL);
           spin_lock_irqsave(&cm.lock, flags);
   
           id = idr_alloc_cyclic(&cm.local_id_table, cm_id_priv, 0, 0, GFP_NOWAIT);
   
           spin_unlock_irqrestore(&cm.lock, flags);
           idr_preload_end();
   
           cm_id_priv->id.local_id = (__force __be32)id ^ cm.random_id_operand;
           return id < 0 ? id : 0;
   }
   
   static void cm_free_id(__be32 local_id)
   {
           spin_lock_irq(&cm.lock);
           idr_remove(&cm.local_id_table,
                      (__force int) (local_id ^ cm.random_id_operand));
           spin_unlock_irq(&cm.lock);
   }
   
   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 ^ cm.random_id_operand));
           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;
   
           spin_lock_irq(&cm.lock);
           cm_id_priv = cm_get_id(local_id, remote_id);
           spin_unlock_irq(&cm.lock);
   
           return cm_id_priv;
   }
   
   /*
    * Trivial helpers to strip endian annotation and compare; the
    * endianness doesn't actually matter since we just need a stable
    * order for the RB tree.
    */
   static int be32_lt(__be32 a, __be32 b)
   {
           return (__force u32) a < (__force u32) b;
   }
   
   static int be32_gt(__be32 a, __be32 b)
   {
           return (__force u32) a > (__force u32) b;
   }
   
   static int be64_lt(__be64 a, __be64 b)
   {
           return (__force u64) a < (__force u64) b;
   }
   
   static int be64_gt(__be64 a, __be64 b)
   {
           return (__force u64) a > (__force u64) b;
   }
   
   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;
   
           while (*link) {
                   parent = *link;
                   cur_cm_id_priv = rb_entry(parent, struct cm_id_private,
                                             service_node);
                   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))
                           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 (be64_lt(service_id, cur_cm_id_priv->id.service_id))
                           link = &(*link)->rb_left;
                   else if (be64_gt(service_id, cur_cm_id_priv->id.service_id))
                           link = &(*link)->rb_right;
                   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)
   {
           struct rb_node *node = cm.listen_service_table.rb_node;
           struct cm_id_private *cm_id_priv;
   
           while (node) {
                   cm_id_priv = rb_entry(node, struct cm_id_private, service_node);
                   if ((cm_id_priv->id.service_mask & service_id) ==
                        cm_id_priv->id.service_id &&
                       (cm_id_priv->id.device == device))
                           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 (be64_lt(service_id, cm_id_priv->id.service_id))
                           node = node->rb_left;
                   else if (be64_gt(service_id, cm_id_priv->id.service_id))
                           node = node->rb_right;
                   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 (be32_lt(remote_id, cur_timewait_info->work.remote_id))
                           link = &(*link)->rb_left;
                   else if (be32_gt(remote_id, cur_timewait_info->work.remote_id))
                           link = &(*link)->rb_right;
                   else if (be64_lt(remote_ca_guid, cur_timewait_info->remote_ca_guid))
                           link = &(*link)->rb_left;
                   else if (be64_gt(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 (be32_lt(remote_id, timewait_info->work.remote_id))
                           node = node->rb_left;
                   else if (be32_gt(remote_id, timewait_info->work.remote_id))
                           node = node->rb_right;
                   else if (be64_lt(remote_ca_guid, timewait_info->remote_ca_guid))
                           node = node->rb_left;
                   else if (be64_gt(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 (be32_lt(remote_qpn, cur_timewait_info->remote_qpn))
                           link = &(*link)->rb_left;
                   else if (be32_gt(remote_qpn, cur_timewait_info->remote_qpn))
                           link = &(*link)->rb_right;
                   else if (be64_lt(remote_ca_guid, cur_timewait_info->remote_ca_guid))
                           link = &(*link)->rb_left;
                   else if (be64_gt(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 (be32_lt(remote_id, cur_cm_id_priv->id.remote_id))
                           link = &(*link)->rb_left;
                   else if (be32_gt(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);
           INIT_LIST_HEAD(&cm_id_priv->prim_list);
           INIT_LIST_HEAD(&cm_id_priv->altr_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);
   }
   
   /*
    * calculate: 4.096x2^ack_timeout = 4.096x2^ack_delay + 2x4.096x2^life_time
    * Because of how ack_timeout is stored, adding one doubles the timeout.
    * To avoid large timeouts, select the max(ack_delay, life_time + 1), and
    * increment it (round up) only if the other is within 50%.
    */
   static u8 cm_ack_timeout(u8 ca_ack_delay, u8 packet_life_time)
   {
           int ack_timeout = packet_life_time + 1;
   
           if (ack_timeout >= ca_ack_delay)
                   ack_timeout += (ca_ack_delay >= (ack_timeout - 1));
           else
                   ack_timeout = ca_ack_delay +
                                 (ack_timeout >= (ca_ack_delay - 1));
   
           return min(31, ack_timeout);
   }
   
   static void cm_cleanup_timewait(struct cm_timewait_info *timewait_info)
   {
           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;
           }
   }
   
   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_DELAYED_WORK(&timewait_info->work.work, cm_work_handler);
           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;
           unsigned long flags;
           struct cm_device *cm_dev;
   
           cm_dev = ib_get_client_data(cm_id_priv->id.device, &cm_client);
           if (!cm_dev)
                   return;
   
           spin_lock_irqsave(&cm.lock, flags);
           cm_cleanup_timewait(cm_id_priv->timewait_info);
           list_add_tail(&cm_id_priv->timewait_info->list, &cm.timewait_list);
           spin_unlock_irqrestore(&cm.lock, flags);
   
           /*
            * 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->av.timeout);
   
           /* Check if the device started its remove_one */
           spin_lock_irqsave(&cm.lock, flags);
           if (!cm_dev->going_down)
                   queue_delayed_work(cm.wq, &cm_id_priv->timewait_info->work.work,
                                      msecs_to_jiffies(wait_time));
           spin_unlock_irqrestore(&cm.lock, flags);
   
           cm_id_priv->timewait_info = NULL;
   }
   
   static void cm_reset_to_idle(struct cm_id_private *cm_id_priv)
   {
           unsigned long flags;
   
           cm_id_priv->id.state = IB_CM_IDLE;
           if (cm_id_priv->timewait_info) {
                   spin_lock_irqsave(&cm.lock, flags);
                   cm_cleanup_timewait(cm_id_priv->timewait_info);
                   spin_unlock_irqrestore(&cm.lock, flags);
                   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;
   
           cm_id_priv = container_of(cm_id, struct cm_id_private, id);
   retest:
           spin_lock_irq(&cm_id_priv->lock);
           switch (cm_id->state) {
           case IB_CM_LISTEN:
                   spin_unlock_irq(&cm_id_priv->lock);
   
                   spin_lock_irq(&cm.lock);
                   if (--cm_id_priv->listen_sharecount > 0) {
                           /* The id is still shared. */
                           cm_deref_id(cm_id_priv);
                           spin_unlock_irq(&cm.lock);
                           return;
                   }
                   rb_erase(&cm_id_priv->service_node, &cm.listen_service_table);
                   spin_unlock_irq(&cm.lock);
                   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_irq(&cm_id_priv->lock);
                   break;
           case IB_CM_SIDR_REQ_RCVD:
                   spin_unlock_irq(&cm_id_priv->lock);
                   cm_reject_sidr_req(cm_id_priv, IB_SIDR_REJECT);
                   spin_lock_irq(&cm.lock);
                   if (!RB_EMPTY_NODE(&cm_id_priv->sidr_id_node))
                           rb_erase(&cm_id_priv->sidr_id_node,
                                   &cm.remote_sidr_table);
                  spin_unlock_irq(&cm.lock);
                  break;
          case IB_CM_REQ_SENT:
          case IB_CM_MRA_REQ_RCVD:
                  ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
                  spin_unlock_irq(&cm_id_priv->lock);
                  ib_send_cm_rej(cm_id, IB_CM_REJ_TIMEOUT,
                                 &cm_id_priv->id.device->node_guid,
                                 sizeof cm_id_priv->id.device->node_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_irq(&cm_id_priv->lock);
                  } else {
                          spin_unlock_irq(&cm_id_priv->lock);
                          ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
                                         NULL, 0, NULL, 0);
                  }
                  break;
          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_irq(&cm_id_priv->lock);
                  ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
                                 NULL, 0, NULL, 0);
                  break;
          case IB_CM_ESTABLISHED:
                  spin_unlock_irq(&cm_id_priv->lock);
                  if (cm_id_priv->qp_type == IB_QPT_XRC_TGT)
                          break;
                  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_irq(&cm_id_priv->lock);
                  break;
          case IB_CM_DREQ_RCVD:
                  spin_unlock_irq(&cm_id_priv->lock);
                  ib_send_cm_drep(cm_id, NULL, 0);
                  break;
          default:
                  spin_unlock_irq(&cm_id_priv->lock);
                  break;
          }
  
          spin_lock_irq(&cm.lock);
          if (!list_empty(&cm_id_priv->altr_list) &&
              (!cm_id_priv->altr_send_port_not_ready))
                  list_del(&cm_id_priv->altr_list);
          if (!list_empty(&cm_id_priv->prim_list) &&
              (!cm_id_priv->prim_send_port_not_ready))
                  list_del(&cm_id_priv->prim_list);
          spin_unlock_irq(&cm.lock);
  
          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->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);
  
  /**
   * __ib_cm_listen - Initiates listening on the specified service ID for
   *   connection and service ID resolution requests.
   * @cm_id: Connection identifier associated with the listen request.
   * @service_id: Service identifier matched against incoming connection
   *   and service ID resolution requests.  The service ID should be specified
   *   network-byte order.  If set to IB_CM_ASSIGN_SERVICE_ID, the CM will
   *   assign a service ID to the caller.
   * @service_mask: Mask applied to service ID used to listen across a
   *   range of service IDs.  If set to 0, the service ID is matched
   *   exactly.  This parameter is ignored if %service_id is set to
   *   IB_CM_ASSIGN_SERVICE_ID.
   */
  static int __ib_cm_listen(struct ib_cm_id *cm_id, __be64 service_id,
                            __be64 service_mask)
  {
          struct cm_id_private *cm_id_priv, *cur_cm_id_priv;
          int ret = 0;
  
          service_mask = service_mask ? service_mask : ~cpu_to_be64(0);
          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;
  
          cm_id->state = IB_CM_LISTEN;
          ++cm_id_priv->listen_sharecount;
  
          if (service_id == IB_CM_ASSIGN_SERVICE_ID) {
                  cm_id->service_id = cpu_to_be64(cm.listen_service_id++);
                  cm_id->service_mask = ~cpu_to_be64(0);
          } else {
                  cm_id->service_id = service_id;
                  cm_id->service_mask = service_mask;
          }
          cur_cm_id_priv = cm_insert_listen(cm_id_priv);
  
          if (cur_cm_id_priv) {
                  cm_id->state = IB_CM_IDLE;
                  --cm_id_priv->listen_sharecount;
                  ret = -EBUSY;
          }
          return ret;
  }
  
  int ib_cm_listen(struct ib_cm_id *cm_id, __be64 service_id, __be64 service_mask)
  {
          unsigned long flags;
          int ret;
  
          spin_lock_irqsave(&cm.lock, flags);
          ret = __ib_cm_listen(cm_id, service_id, service_mask);
          spin_unlock_irqrestore(&cm.lock, flags);
  
          return ret;
  }
  EXPORT_SYMBOL(ib_cm_listen);
  
  /**
   * Create a new listening ib_cm_id and listen on the given service ID.
   *
   * If there's an existing ID listening on that same device and service ID,
   * return it.
   *
   * @device: Device associated with the cm_id.  All related communication will
   * be associated with the specified device.
   * @cm_handler: Callback invoked to notify the user of CM events.
   * @service_id: Service identifier matched against incoming connection
   *   and service ID resolution requests.  The service ID should be specified
   *   network-byte order.  If set to IB_CM_ASSIGN_SERVICE_ID, the CM will
   *   assign a service ID to the caller.
   *
   * Callers should call ib_destroy_cm_id when done with the listener ID.
   */
  struct ib_cm_id *ib_cm_insert_listen(struct ib_device *device,
                                       ib_cm_handler cm_handler,
                                       __be64 service_id)
  {
          struct cm_id_private *cm_id_priv;
          struct ib_cm_id *cm_id;
          unsigned long flags;
          int err = 0;
  
          /* Create an ID in advance, since the creation may sleep */
          cm_id = ib_create_cm_id(device, cm_handler, NULL);
          if (IS_ERR(cm_id))
                  return cm_id;
  
          spin_lock_irqsave(&cm.lock, flags);
  
          if (service_id == IB_CM_ASSIGN_SERVICE_ID)
                  goto new_id;
  
          /* Find an existing ID */
          cm_id_priv = cm_find_listen(device, service_id);
          if (cm_id_priv) {
                  if (cm_id->cm_handler != cm_handler || cm_id->context) {
                          /* Sharing an ib_cm_id with different handlers is not
                           * supported */
                          spin_unlock_irqrestore(&cm.lock, flags);
                          ib_destroy_cm_id(cm_id);
                          return ERR_PTR(-EINVAL);
                  }
                  atomic_inc(&cm_id_priv->refcount);
                  ++cm_id_priv->listen_sharecount;
                  spin_unlock_irqrestore(&cm.lock, flags);
  
                  ib_destroy_cm_id(cm_id);
                  cm_id = &cm_id_priv->id;
                  return cm_id;
          }
  
  new_id:
          /* Use newly created ID */
          err = __ib_cm_listen(cm_id, service_id, 0);
  
          spin_unlock_irqrestore(&cm.lock, flags);
  
          if (err) {
                  ib_destroy_cm_id(cm_id);
                  return ERR_PTR(err);
          }
          return cm_id;
  }
  EXPORT_SYMBOL(ib_cm_insert_listen);
  
  static __be64 cm_form_tid(struct cm_id_private *cm_id_priv)
  {
          u64 hi_tid, low_tid;
  
          hi_tid   = ((u64) cm_id_priv->av.port->mad_agent->hi_tid) << 32;
          low_tid  = (u64)cm_id_priv->id.local_id;
          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)
  {
          struct ib_sa_path_rec *pri_path = param->primary_path;
          struct ib_sa_path_rec *alt_path = param->alternate_path;
  
          cm_format_mad_hdr(&req_msg->hdr, CM_REQ_ATTR_ID,
                            cm_form_tid(cm_id_priv));
  
          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->id.device->node_guid;
          cm_req_set_local_qpn(req_msg, cpu_to_be32(param->qp_num));
          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);
          req_msg->pkey = param->primary_path->pkey;
          cm_req_set_path_mtu(req_msg, param->primary_path->mtu);
          cm_req_set_max_cm_retries(req_msg, param->max_cm_retries);
  
          if (param->qp_type != IB_QPT_XRC_INI) {
                  cm_req_set_resp_res(req_msg, param->responder_resources);
                  cm_req_set_retry_count(req_msg, param->retry_count);
                  cm_req_set_rnr_retry_count(req_msg, param->rnr_retry_count);
                  cm_req_set_srq(req_msg, param->srq);
          }
  
          if (pri_path->hop_limit <= 1) {
                  req_msg->primary_local_lid = pri_path->slid;
                  req_msg->primary_remote_lid = pri_path->dlid;
          } else {
                  /* Work-around until there's a way to obtain remote LID info */
                  req_msg->primary_local_lid = IB_LID_PERMISSIVE;
                  req_msg->primary_remote_lid = IB_LID_PERMISSIVE;
          }
          req_msg->primary_local_gid = pri_path->sgid;
          req_msg->primary_remote_gid = pri_path->dgid;
          cm_req_set_primary_flow_label(req_msg, pri_path->flow_label);
          cm_req_set_primary_packet_rate(req_msg, pri_path->rate);
          req_msg->primary_traffic_class = pri_path->traffic_class;
          req_msg->primary_hop_limit = pri_path->hop_limit;
          cm_req_set_primary_sl(req_msg, pri_path->sl);
          cm_req_set_primary_subnet_local(req_msg, (pri_path->hop_limit <= 1));
          cm_req_set_primary_local_ack_timeout(req_msg,
                  cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
                                 pri_path->packet_life_time));
  
          if (alt_path) {
                  if (alt_path->hop_limit <= 1) {
                          req_msg->alt_local_lid = alt_path->slid;
                          req_msg->alt_remote_lid = alt_path->dlid;
                  } else {
                          req_msg->alt_local_lid = IB_LID_PERMISSIVE;
                          req_msg->alt_remote_lid = IB_LID_PERMISSIVE;
                  }
                  req_msg->alt_local_gid = alt_path->sgid;
                  req_msg->alt_remote_gid = alt_path->dgid;
                  cm_req_set_alt_flow_label(req_msg,
                                            alt_path->flow_label);
                  cm_req_set_alt_packet_rate(req_msg, alt_path->rate);
                  req_msg->alt_traffic_class = alt_path->traffic_class;
                  req_msg->alt_hop_limit = alt_path->hop_limit;
                  cm_req_set_alt_sl(req_msg, alt_path->sl);
                  cm_req_set_alt_subnet_local(req_msg, (alt_path->hop_limit <= 1));
                  cm_req_set_alt_local_ack_timeout(req_msg,
                          cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
                                         alt_path->packet_life_time));
          }
  
          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 &&
              param->qp_type != IB_QPT_XRC_INI)
                  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,
                                   cm_id_priv);
          if (ret)
                  goto error1;
          if (param->alternate_path) {
                  ret = cm_init_av_by_path(param->alternate_path,
                                           &cm_id_priv->alt_av, cm_id_priv);
                  if (ret)
                          goto error1;
          }
          cm_id->service_id = param->service_id;
          cm_id->service_mask = ~cpu_to_be64(0);
          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->pkey = param->primary_path->pkey;
          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);
  
          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 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);
          primary_path->service_id = req_msg->service_id;
  
          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);
                  alt_path->service_id = req_msg->service_id;
          }
  }
  
  static u16 cm_get_bth_pkey(struct cm_work *work)
  {
          struct ib_device *ib_dev = work->port->cm_dev->ib_device;
          u8 port_num = work->port->port_num;
          u16 pkey_index = work->mad_recv_wc->wc->pkey_index;
          u16 pkey;
          int ret;
  
          ret = ib_get_cached_pkey(ib_dev, port_num, pkey_index, &pkey);
          if (ret) {
                  dev_warn_ratelimited(&ib_dev->dev, "ib_cm: Couldn't retrieve pkey for incoming request (port %d, pkey index %d). %d\n",
                                       port_num, pkey_index, ret);
                  return 0;
          }
  
          return pkey;
  }
  
  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->bth_pkey = cm_get_bth_pkey(work);
          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);
          param->ppath_sgid_index = cm_id_priv->av.ah_attr.grh.sgid_index;
          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)
  {
          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_irq(&cm_id_priv->lock);
                  work = cm_dequeue_work(cm_id_priv);
                  spin_unlock_irq(&cm_id_priv->lock);
                  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;
          int ret;
  
          atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                          counter[CM_REQ_COUNTER]);
  
          /* 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_irq(&cm_id_priv->lock);
          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_irq(&cm_id_priv->lock);
  
          ret = ib_post_send_mad(msg, NULL);
          if (ret)
                  goto free;
          return;
  
  unlock: spin_unlock_irq(&cm_id_priv->lock);
  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;
          struct ib_cm_id *cm_id;
  
          req_msg = (struct cm_req_msg *)work->mad_recv_wc->recv_buf.mad;
  
          /* Check for possible duplicate REQ. */
          spin_lock_irq(&cm.lock);
          timewait_info = cm_insert_remote_id(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_irq(&cm.lock);
                  if (cur_cm_id_priv) {
                          cm_dup_req_handler(work, cur_cm_id_priv);
                          cm_deref_id(cur_cm_id_priv);
                  }
                  return NULL;
          }
  
          /* Check for stale connections. */
          timewait_info = cm_insert_remote_qpn(cm_id_priv->timewait_info);
          if (timewait_info) {
                  cm_cleanup_timewait(cm_id_priv->timewait_info);
                  cur_cm_id_priv = cm_get_id(timewait_info->work.local_id,
                                             timewait_info->work.remote_id);
  
                  spin_unlock_irq(&cm.lock);
                  cm_issue_rej(work->port, work->mad_recv_wc,
                               IB_CM_REJ_STALE_CONN, CM_MSG_RESPONSE_REQ,
                               NULL, 0);
                  if (cur_cm_id_priv) {
                          cm_id = &cur_cm_id_priv->id;
                          ib_send_cm_dreq(cm_id, NULL, 0);
                          cm_deref_id(cur_cm_id_priv);
                  }
                  return NULL;
          }
  
          /* Find matching listen request. */
          listen_cm_id_priv = cm_find_listen(cm_id_priv->id.device,
                                             req_msg->service_id);
          if (!listen_cm_id_priv) {
                  cm_cleanup_timewait(cm_id_priv->timewait_info);
                  spin_unlock_irq(&cm.lock);
                  cm_issue_rej(work->port, work->mad_recv_wc,
                               IB_CM_REJ_INVALID_SERVICE_ID, CM_MSG_RESPONSE_REQ,
                               NULL, 0);
                  goto out;
          }
          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_irq(&cm.lock);
  out:
          return listen_cm_id_priv;
  }
  
  /*
   * Work-around for inter-subnet connections.  If the LIDs are permissive,
   * we need to override the LID/SL data in the REQ with the LID information
   * in the work completion.
   */
  static void cm_process_routed_req(struct cm_req_msg *req_msg, struct ib_wc *wc)
  {
          if (!cm_req_get_primary_subnet_local(req_msg)) {
                  if (req_msg->primary_local_lid == IB_LID_PERMISSIVE) {
                          req_msg->primary_local_lid = cpu_to_be16(wc->slid);
                          cm_req_set_primary_sl(req_msg, wc->sl);
                  }
  
                  if (req_msg->primary_remote_lid == IB_LID_PERMISSIVE)
                          req_msg->primary_remote_lid = cpu_to_be16(wc->dlid_path_bits);
          }
  
          if (!cm_req_get_alt_subnet_local(req_msg)) {
                  if (req_msg->alt_local_lid == IB_LID_PERMISSIVE) {
                          req_msg->alt_local_lid = cpu_to_be16(wc->slid);
                          cm_req_set_alt_sl(req_msg, wc->sl);
                  }
  
                  if (req_msg->alt_remote_lid == IB_LID_PERMISSIVE)
                          req_msg->alt_remote_lid = cpu_to_be16(wc->dlid_path_bits);
          }
  }
  
  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;
          union ib_gid gid;
          struct ib_gid_attr gid_attr;
          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->ib_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;
          ret = cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
                                        work->mad_recv_wc->recv_buf.grh,
                                        &cm_id_priv->av);
          if (ret)
                  goto destroy;
          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 destroy;
          }
          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 free_timeinfo;
          }
  
          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 = ~cpu_to_be64(0);
  
          cm_process_routed_req(req_msg, work->mad_recv_wc->wc);
          cm_format_paths_from_req(req_msg, &work->path[0], &work->path[1]);
  
          memcpy(work->path[0].dmac, cm_id_priv->av.ah_attr.dmac, ETH_ALEN);
          work->path[0].hop_limit = cm_id_priv->av.ah_attr.grh.hop_limit;
          ret = ib_get_cached_gid(work->port->cm_dev->ib_device,
                                  work->port->port_num,
                                  cm_id_priv->av.ah_attr.grh.sgid_index,
                                  &gid, &gid_attr);
          if (!ret) {
                  if (gid_attr.ndev) {
                          work->path[0].ifindex = gid_attr.ndev->if_index;
                          work->path[0].net = dev_net(gid_attr.ndev);
                          dev_put(gid_attr.ndev);
                  }
                  work->path[0].gid_type = gid_attr.gid_type;
                  ret = cm_init_av_by_path(&work->path[0], &cm_id_priv->av,
                                           cm_id_priv);
          }
          if (ret) {
                  int err = ib_get_cached_gid(work->port->cm_dev->ib_device,
                                              work->port->port_num, 0,
                                              &work->path[0].sgid,
                                              &gid_attr);
                  if (!err && gid_attr.ndev) {
                          work->path[0].ifindex = gid_attr.ndev->if_index;
                          work->path[0].net = dev_net(gid_attr.ndev);
                          dev_put(gid_attr.ndev);
                  }
                  work->path[0].gid_type = gid_attr.gid_type;
                  ib_send_cm_rej(cm_id, IB_CM_REJ_INVALID_GID,
                                 &work->path[0].sgid, sizeof work->path[0].sgid,
                                 NULL, 0);
                  goto rejected;
          }
          if (req_msg->alt_local_lid) {
                  ret = cm_init_av_by_path(&work->path[1], &cm_id_priv->alt_av,
                                           cm_id_priv);
                  if (ret) {
                          ib_send_cm_rej(cm_id, IB_CM_REJ_INVALID_ALT_GID,
                                         &work->path[0].sgid,
                                         sizeof work->path[0].sgid, NULL, 0);
                          goto rejected;
                  }
          }
          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->pkey = req_msg->pkey;
          cm_id_priv->sq_psn = cm_req_get_starting_psn(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;
  
  rejected:
          atomic_dec(&cm_id_priv->refcount);
          cm_deref_id(listen_cm_id_priv);
  free_timeinfo:
          kfree(cm_id_priv->timewait_info);
  destroy:
          ib_destroy_cm_id(cm_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_starting_psn(rep_msg, cpu_to_be32(param->starting_psn));
          rep_msg->resp_resources = param->responder_resources;
          cm_rep_set_target_ack_delay(rep_msg,
                                      cm_id_priv->av.port->cm_dev->ack_delay);
          cm_rep_set_failover(rep_msg, param->failover_accepted);
          cm_rep_set_rnr_retry_count(rep_msg, param->rnr_retry_count);
          rep_msg->local_ca_guid = cm_id_priv->id.device->node_guid;
  
          if (cm_id_priv->qp_type != IB_QPT_XRC_TGT) {
                  rep_msg->initiator_depth = param->initiator_depth;
                  cm_rep_set_flow_ctrl(rep_msg, param->flow_control);
                  cm_rep_set_srq(rep_msg, param->srq);
                  cm_rep_set_local_qpn(rep_msg, cpu_to_be32(param->qp_num));
          } else {
                  cm_rep_set_srq(rep_msg, 1);
                  cm_rep_set_local_eecn(rep_msg, cpu_to_be32(param->qp_num));
          }
  
          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 = cpu_to_be32(param->qp_num & 0xFFFFFF);
  
  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, enum ib_qp_type qp_type)
  {
          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_qpn(rep_msg, qp_type));
          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;
          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;
  
          atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                          counter[CM_REP_COUNTER]);
          ret = cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg);
          if (ret)
                  goto deref;
  
          spin_lock_irq(&cm_id_priv->lock);
          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_irq(&cm_id_priv->lock);
  
          ret = ib_post_send_mad(msg, NULL);
          if (ret)
                  goto free;
          goto deref;
  
  unlock: spin_unlock_irq(&cm_id_priv->lock);
  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;
          int ret;
          struct cm_id_private *cur_cm_id_priv;
          struct ib_cm_id *cm_id;
          struct cm_timewait_info *timewait_info;
  
          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, cm_id_priv->qp_type);
  
          spin_lock_irq(&cm_id_priv->lock);
          switch (cm_id_priv->id.state) {
          case IB_CM_REQ_SENT:
          case IB_CM_MRA_REQ_RCVD:
                  break;
          default:
                  spin_unlock_irq(&cm_id_priv->lock);
                  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_qpn(rep_msg, cm_id_priv->qp_type);
  
          spin_lock(&cm.lock);
          /* Check for duplicate REP. */
          if (cm_insert_remote_id(cm_id_priv->timewait_info)) {
                  spin_unlock(&cm.lock);
                  spin_unlock_irq(&cm_id_priv->lock);
                  ret = -EINVAL;
                  goto error;
          }
          /* Check for a stale connection. */
          timewait_info = cm_insert_remote_qpn(cm_id_priv->timewait_info);
          if (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;
                  cur_cm_id_priv = cm_get_id(timewait_info->work.local_id,
                                             timewait_info->work.remote_id);
  
                  spin_unlock(&cm.lock);
                  spin_unlock_irq(&cm_id_priv->lock);
                  cm_issue_rej(work->port, work->mad_recv_wc,
                               IB_CM_REJ_STALE_CONN, CM_MSG_RESPONSE_REP,
                               NULL, 0);
                  ret = -EINVAL;
                  if (cur_cm_id_priv) {
                          cm_id = &cur_cm_id_priv->id;
                          ib_send_cm_dreq(cm_id, NULL, 0);
                          cm_deref_id(cur_cm_id_priv);
                  }
  
                  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_qpn(rep_msg, cm_id_priv->qp_type);
          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);
          cm_id_priv->target_ack_delay = cm_rep_get_target_ack_delay(rep_msg);
          cm_id_priv->av.timeout =
                          cm_ack_timeout(cm_id_priv->target_ack_delay,
                                         cm_id_priv->av.timeout - 1);
          cm_id_priv->alt_av.timeout =
                          cm_ack_timeout(cm_id_priv->target_ack_delay,
                                         cm_id_priv->alt_av.timeout - 1);
  
          /* 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_irq(&cm_id_priv->lock);
  
          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;
          int ret;
  
          /* See comment in cm_establish about lookup. */
          cm_id_priv = cm_acquire_id(work->local_id, work->remote_id);
          if (!cm_id_priv)
                  return -EINVAL;
  
          spin_lock_irq(&cm_id_priv->lock);
          if (cm_id_priv->id.state != IB_CM_ESTABLISHED) {
                  spin_unlock_irq(&cm_id_priv->lock);
                  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_irq(&cm_id_priv->lock);
  
          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;
          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_irq(&cm_id_priv->lock);
          if (cm_id_priv->id.state != IB_CM_REP_SENT &&
              cm_id_priv->id.state != IB_CM_MRA_REP_RCVD) {
                  spin_unlock_irq(&cm_id_priv->lock);
                  atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                  counter[CM_RTU_COUNTER]);
                  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_irq(&cm_id_priv->lock);
  
          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));
          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;
          }
  
          if (cm_id->lap_state == IB_CM_LAP_SENT ||
              cm_id->lap_state == IB_CM_MRA_LAP_RCVD)
                  ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
  
          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_issue_drep(struct cm_port *port,
                           struct ib_mad_recv_wc *mad_recv_wc)
  {
          struct ib_mad_send_buf *msg = NULL;
          struct cm_dreq_msg *dreq_msg;
          struct cm_drep_msg *drep_msg;
          int ret;
  
          ret = cm_alloc_response_msg(port, mad_recv_wc, &msg);
          if (ret)
                  return ret;
  
          dreq_msg = (struct cm_dreq_msg *) mad_recv_wc->recv_buf.mad;
          drep_msg = (struct cm_drep_msg *) msg->mad;
  
          cm_format_mad_hdr(&drep_msg->hdr, CM_DREP_ATTR_ID, dreq_msg->hdr.tid);
          drep_msg->remote_comm_id = dreq_msg->local_comm_id;
          drep_msg->local_comm_id = dreq_msg->remote_comm_id;
  
          ret = ib_post_send_mad(msg, NULL);
          if (ret)
                  cm_free_msg(msg);
  
          return ret;
  }
  
  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;
          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) {
                  atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                  counter[CM_DREQ_COUNTER]);
                  cm_issue_drep(work->port, work->mad_recv_wc);
                  return -EINVAL;
          }
  
          work->cm_event.private_data = &dreq_msg->private_data;
  
          spin_lock_irq(&cm_id_priv->lock);
          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:
                  if (cm_id_priv->id.lap_state == IB_CM_LAP_SENT ||
                      cm_id_priv->id.lap_state == IB_CM_MRA_LAP_RCVD)
                          ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
                  break;
          case IB_CM_MRA_REP_RCVD:
                  break;
          case IB_CM_TIMEWAIT:
                  atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                  counter[CM_DREQ_COUNTER]);
                  msg = cm_alloc_response_msg_no_ah(work->port, work->mad_recv_wc);
                  if (IS_ERR(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_irq(&cm_id_priv->lock);
  
                  if (cm_create_response_msg_ah(work->port, work->mad_recv_wc, msg) ||
                      ib_post_send_mad(msg, NULL))
                          cm_free_msg(msg);
                  goto deref;
          case IB_CM_DREQ_RCVD:
                  atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                  counter[CM_DREQ_COUNTER]);
                  goto unlock;
          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_irq(&cm_id_priv->lock);
  
          if (ret)
                  cm_process_work(cm_id_priv, work);
          else
                  cm_deref_id(cm_id_priv);
          return 0;
  
  unlock: spin_unlock_irq(&cm_id_priv->lock);
  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;
          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_irq(&cm_id_priv->lock);
          if (cm_id_priv->id.state != IB_CM_DREQ_SENT &&
              cm_id_priv->id.state != IB_CM_DREQ_RCVD) {
                  spin_unlock_irq(&cm_id_priv->lock);
                  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_irq(&cm_id_priv->lock);
  
          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;
          __be32 remote_id;
  
          remote_id = rej_msg->local_comm_id;
  
          if (__be16_to_cpu(rej_msg->reason) == IB_CM_REJ_TIMEOUT) {
                  spin_lock_irq(&cm.lock);
                  timewait_info = cm_find_remote_id( *((__be64 *) rej_msg->ari),
                                                    remote_id);
                  if (!timewait_info) {
                          spin_unlock_irq(&cm.lock);
                          return NULL;
                  }
                  cm_id_priv = idr_find(&cm.local_id_table, (__force int)
                                        (timewait_info->work.local_id ^
                                         cm.random_id_operand));
                  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_irq(&cm.lock);
          } 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;
          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_irq(&cm_id_priv->lock);
          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:
                  cm_enter_timewait(cm_id_priv);
                  break;
          case IB_CM_ESTABLISHED:
                  if (cm_id_priv->id.lap_state == IB_CM_LAP_UNINIT ||
                      cm_id_priv->id.lap_state == IB_CM_LAP_SENT) {
                          if (cm_id_priv->id.lap_state == IB_CM_LAP_SENT)
                                  ib_cancel_mad(cm_id_priv->av.port->mad_agent,
                                                cm_id_priv->msg);
                          cm_enter_timewait(cm_id_priv);
                          break;
                  }
                  /* fall through */
          default:
                  spin_unlock_irq(&cm_id_priv->lock);
                  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_irq(&cm_id_priv->lock);
  
          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;
          enum ib_cm_state cm_state;
          enum ib_cm_lap_state lap_state;
          enum cm_msg_response msg_response;
          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:
                  cm_state = IB_CM_MRA_REQ_SENT;
                  lap_state = cm_id->lap_state;
                  msg_response = CM_MSG_RESPONSE_REQ;
                  break;
          case IB_CM_REP_RCVD:
                  cm_state = IB_CM_MRA_REP_SENT;
                  lap_state = cm_id->lap_state;
                  msg_response = CM_MSG_RESPONSE_REP;
                  break;
          case IB_CM_ESTABLISHED:
                  if (cm_id->lap_state == IB_CM_LAP_RCVD) {
                          cm_state = cm_id->state;
                          lap_state = IB_CM_MRA_LAP_SENT;
                          msg_response = CM_MSG_RESPONSE_OTHER;
                          break;
                  }
          default:
                  ret = -EINVAL;
                  goto error1;
          }
  
          if (!(service_timeout & IB_CM_MRA_FLAG_DELAY)) {
                  ret = cm_alloc_msg(cm_id_priv, &msg);
                  if (ret)
                          goto error1;
  
                  cm_format_mra((struct cm_mra_msg *) msg->mad, cm_id_priv,
                                msg_response, service_timeout,
                                private_data, private_data_len);
                  ret = ib_post_send_mad(msg, NULL);
                  if (ret)
                          goto error2;
          }
  
          cm_id->state = cm_state;
          cm_id->lap_state = lap_state;
          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;
          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.timeout);
  
          spin_lock_irq(&cm_id_priv->lock);
          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)) {
                          if (cm_id_priv->id.lap_state == IB_CM_MRA_LAP_RCVD)
                                  atomic_long_inc(&work->port->
                                                  counter_group[CM_RECV_DUPLICATES].
                                                  counter[CM_MRA_COUNTER]);
                          goto out;
                  }
                  cm_id_priv->id.lap_state = IB_CM_MRA_LAP_RCVD;
                  break;
          case IB_CM_MRA_REQ_RCVD:
          case IB_CM_MRA_REP_RCVD:
                  atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                  counter[CM_MRA_COUNTER]);
                  /* fall through */
          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_irq(&cm_id_priv->lock);
  
          if (ret)
                  cm_process_work(cm_id_priv, work);
          else
                  cm_deref_id(cm_id_priv);
          return 0;
  out:
          spin_unlock_irq(&cm_id_priv->lock);
          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));
          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,
                  cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
                                 alternate_path->packet_life_time));
  
          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_UNINIT &&
               cm_id->lap_state != IB_CM_LAP_IDLE)) {
                  ret = -EINVAL;
                  goto out;
          }
  
          ret = cm_init_av_by_path(alternate_path, &cm_id_priv->alt_av,
                                   cm_id_priv);
          if (ret)
                  goto out;
          cm_id_priv->alt_av.timeout =
                          cm_ack_timeout(cm_id_priv->target_ack_delay,
                                         cm_id_priv->alt_av.timeout - 1);
  
          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 cm_id_private *cm_id_priv,
                                      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;
          path->pkey = cm_id_priv->pkey;
          path->sl = cm_lap_get_sl(lap_msg);
          path->mtu_selector = IB_SA_EQ;
          path->mtu = cm_id_priv->path_mtu;
          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;
          int ret;
  
          /* Currently Alternate path messages are not supported for
           * RoCE link layer.
           */
          if (rdma_protocol_roce(work->port->cm_dev->ib_device,
                                 work->port->port_num))
                  return -EINVAL;
  
          /* 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(cm_id_priv, param->alternate_path, lap_msg);
          work->cm_event.private_data = &lap_msg->private_data;
  
          spin_lock_irq(&cm_id_priv->lock);
          if (cm_id_priv->id.state != IB_CM_ESTABLISHED)
                  goto unlock;
  
          switch (cm_id_priv->id.lap_state) {
          case IB_CM_LAP_UNINIT:
          case IB_CM_LAP_IDLE:
                  break;
          case IB_CM_MRA_LAP_SENT:
                  atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                  counter[CM_LAP_COUNTER]);
                  msg = cm_alloc_response_msg_no_ah(work->port, work->mad_recv_wc);
                  if (IS_ERR(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_irq(&cm_id_priv->lock);
  
                  if (cm_create_response_msg_ah(work->port, work->mad_recv_wc, msg) ||
                      ib_post_send_mad(msg, NULL))
                          cm_free_msg(msg);
                  goto deref;
          case IB_CM_LAP_RCVD:
                  atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                  counter[CM_LAP_COUNTER]);
                  goto unlock;
          default:
                  goto unlock;
          }
  
          cm_id_priv->id.lap_state = IB_CM_LAP_RCVD;
          cm_id_priv->tid = lap_msg->hdr.tid;
          ret = cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
                                        work->mad_recv_wc->recv_buf.grh,
                                        &cm_id_priv->av);
          if (ret)
                  goto unlock;
          ret = cm_init_av_by_path(param->alternate_path, &cm_id_priv->alt_av,
                                   cm_id_priv);
          if (ret)
                  goto unlock;
          ret = atomic_inc_and_test(&cm_id_priv->work_count);
          if (!ret)
                  list_add_tail(&work->list, &cm_id_priv->work_list);
          spin_unlock_irq(&cm_id_priv->lock);
  
          if (ret)
                  cm_process_work(cm_id_priv, work);
          else
                  cm_deref_id(cm_id_priv);
          return 0;
  
  unlock: spin_unlock_irq(&cm_id_priv->lock);
  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;
          int ret;
  
          /* Currently Alternate path messages are not supported for
           * RoCE link layer.
           */
          if (rdma_protocol_roce(work->port->cm_dev->ib_device,
                                 work->port->port_num))
                  return -EINVAL;
  
          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_irq(&cm_id_priv->lock);
          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_irq(&cm_id_priv->lock);
                  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_irq(&cm_id_priv->lock);
  
          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;
          int ret;
  
          timewait_info = (struct cm_timewait_info *)work;
          spin_lock_irq(&cm.lock);
          list_del(&timewait_info->list);
          spin_unlock_irq(&cm.lock);
  
          cm_id_priv = cm_acquire_id(timewait_info->work.local_id,
                                     timewait_info->work.remote_id);
          if (!cm_id_priv)
                  return -EINVAL;
  
          spin_lock_irq(&cm_id_priv->lock);
          if (cm_id_priv->id.state != IB_CM_TIMEWAIT ||
              cm_id_priv->remote_qpn != timewait_info->remote_qpn) {
                  spin_unlock_irq(&cm_id_priv->lock);
                  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_irq(&cm_id_priv->lock);
  
          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));
          sidr_req_msg->request_id = cm_id_priv->id.local_id;
          sidr_req_msg->pkey = 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, cm_id_priv);
          if (ret)
                  goto out;
  
          cm_id->service_id = param->service_id;
          cm_id->service_mask = ~cpu_to_be64(0);
          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,
                                       const struct cm_id_private *rx_cm_id,
                                       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->service_id = sidr_req_msg->service_id;
          param->bth_pkey = cm_get_bth_pkey(work);
          param->port = work->port->port_num;
          param->sgid_index = rx_cm_id->av.ah_attr.grh.sgid_index;
          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;
          int ret;
  
          cm_id = ib_create_cm_id(work->port->cm_dev->ib_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;
          ret = cm_init_av_for_lap(work->port, work->mad_recv_wc->wc,
                                   work->mad_recv_wc->recv_buf.grh,
                                   &cm_id_priv->av);
          if (ret)
                  goto out;
          cm_id_priv->id.remote_id = sidr_req_msg->request_id;
          cm_id_priv->tid = sidr_req_msg->hdr.tid;
          atomic_inc(&cm_id_priv->work_count);
  
          spin_lock_irq(&cm.lock);
          cur_cm_id_priv = cm_insert_remote_sidr(cm_id_priv);
          if (cur_cm_id_priv) {
                  spin_unlock_irq(&cm.lock);
                  atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                  counter[CM_SIDR_REQ_COUNTER]);
                  goto out; /* Duplicate message. */
          }
          cm_id_priv->id.state = IB_CM_SIDR_REQ_RCVD;
          cur_cm_id_priv = cm_find_listen(cm_id->device,
                                          sidr_req_msg->service_id);
          if (!cur_cm_id_priv) {
                  spin_unlock_irq(&cm.lock);
                  cm_reject_sidr_req(cm_id_priv, IB_SIDR_UNSUPPORTED);
                  goto out; /* No match. */
          }
          atomic_inc(&cur_cm_id_priv->refcount);
          atomic_inc(&cm_id_priv->refcount);
          spin_unlock_irq(&cm.lock);
  
          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 = ~cpu_to_be64(0);
  
          cm_format_sidr_req_event(work, cm_id_priv, &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);
          if (!RB_EMPTY_NODE(&cm_id_priv->sidr_id_node)) {
                  rb_erase(&cm_id_priv->sidr_id_node, &cm.remote_sidr_table);
                  RB_CLEAR_NODE(&cm_id_priv->sidr_id_node);
          }
          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;
  
          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_irq(&cm_id_priv->lock);
          if (cm_id_priv->id.state != IB_CM_SIDR_REQ_SENT) {
                  spin_unlock_irq(&cm_id_priv->lock);
                  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_irq(&cm_id_priv->lock);
  
          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;
          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_irq(&cm_id_priv->lock);
          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_irq(&cm_id_priv->lock);
          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_irq(&cm_id_priv->lock);
          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;
          struct cm_port *port;
          u16 attr_index;
  
          port = mad_agent->context;
          attr_index = be16_to_cpu(((struct ib_mad_hdr *)
                                    msg->mad)->attr_id) - CM_ATTR_ID_OFFSET;
  
          /*
           * If the send was in response to a received message (context[0] is not
           * set to a cm_id), and is not a REJ, then it is a send that was
           * manually retried.
           */
          if (!msg->context[0] && (attr_index != CM_REJ_COUNTER))
                  msg->retries = 1;
  
          atomic_long_add(1 + msg->retries,
                          &port->counter_group[CM_XMIT].counter[attr_index]);
          if (msg->retries)
                  atomic_long_add(msg->retries,
                                  &port->counter_group[CM_XMIT_RETRIES].
                                  counter[attr_index]);
  
          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(struct work_struct *_work)
  {
          struct cm_work *work = container_of(_work, struct cm_work, work.work);
          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);
  }
  
  static int 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;
          struct cm_device *cm_dev;
  
          cm_dev = ib_get_client_data(cm_id->device, &cm_client);
          if (!cm_dev)
                  return -ENODEV;
  
          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_DELAYED_WORK(&work->work, cm_work_handler);
          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;
  
          /* Check if the device started its remove_one */
          spin_lock_irqsave(&cm.lock, flags);
          if (!cm_dev->going_down) {
                  queue_delayed_work(cm.wq, &work->work, 0);
          } else {
                  kfree(work);
                  ret = -ENODEV;
          }
          spin_unlock_irqrestore(&cm.lock, flags);
  
  out:
          return ret;
  }
  
  static int cm_migrate(struct ib_cm_id *cm_id)
  {
          struct cm_id_private *cm_id_priv;
          struct cm_av tmp_av;
          unsigned long flags;
          int tmp_send_port_not_ready;
          int ret = 0;
  
          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_UNINIT ||
               cm_id->lap_state == IB_CM_LAP_IDLE)) {
                  cm_id->lap_state = IB_CM_LAP_IDLE;
                  /* Swap address vector */
                  tmp_av = cm_id_priv->av;
                  cm_id_priv->av = cm_id_priv->alt_av;
                  cm_id_priv->alt_av = tmp_av;
                  /* Swap port send ready state */
                  tmp_send_port_not_ready = cm_id_priv->prim_send_port_not_ready;
                  cm_id_priv->prim_send_port_not_ready = cm_id_priv->altr_send_port_not_ready;
                  cm_id_priv->altr_send_port_not_ready = tmp_send_port_not_ready;
          } else
                  ret = -EINVAL;
          spin_unlock_irqrestore(&cm_id_priv->lock, flags);
  
          return ret;
  }
  
  int ib_cm_notify(struct ib_cm_id *cm_id, enum ib_event_type event)
  {
          int ret;
  
          switch (event) {
          case IB_EVENT_COMM_EST:
                  ret = cm_establish(cm_id);
                  break;
          case IB_EVENT_PATH_MIG:
                  ret = cm_migrate(cm_id);
                  break;
          default:
                  ret = -EINVAL;
          }
          return ret;
  }
  EXPORT_SYMBOL(ib_cm_notify);
  
  static void cm_recv_handler(struct ib_mad_agent *mad_agent,
                              struct ib_mad_send_buf *send_buf,
                              struct ib_mad_recv_wc *mad_recv_wc)
  {
          struct cm_port *port = mad_agent->context;
          struct cm_work *work;
          enum ib_cm_event_type event;
          u16 attr_id;
          int paths = 0;
          int going_down = 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;
          }
  
          attr_id = be16_to_cpu(mad_recv_wc->recv_buf.mad->mad_hdr.attr_id);
          atomic_long_inc(&port->counter_group[CM_RECV].
                          counter[attr_id - CM_ATTR_ID_OFFSET]);
  
          work = kmalloc(sizeof *work + sizeof(struct ib_sa_path_rec) * paths,
                         GFP_KERNEL);
          if (!work) {
                  ib_free_recv_mad(mad_recv_wc);
                  return;
          }
  
          INIT_DELAYED_WORK(&work->work, cm_work_handler);
          work->cm_event.event = event;
          work->mad_recv_wc = mad_recv_wc;
          work->port = port;
  
          /* Check if the device started its remove_one */
          spin_lock_irq(&cm.lock);
          if (!port->cm_dev->going_down)
                  queue_delayed_work(cm.wq, &work->work, 0);
          else
                  going_down = 1;
          spin_unlock_irq(&cm.lock);
  
          if (going_down) {
                  kfree(work);
                  ib_free_recv_mad(mad_recv_wc);
          }
  }
  
  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_REMOTE_WRITE;
                  if (cm_id_priv->responder_resources)
                          qp_attr->qp_access_flags |= IB_ACCESS_REMOTE_READ |
                                                      IB_ACCESS_REMOTE_ATOMIC;
                  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 ||
                      cm_id_priv->qp_type == IB_QPT_XRC_TGT) {
                          *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_pkey_index = cm_id_priv->alt_av.pkey_index;
                          qp_attr->alt_timeout = cm_id_priv->alt_av.timeout;
                          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) {
          /* Allow transition to RTS before sending REP */
          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:
                  if (cm_id_priv->id.lap_state == IB_CM_LAP_UNINIT) {
                          *qp_attr_mask = IB_QP_STATE | IB_QP_SQ_PSN;
                          qp_attr->sq_psn = be32_to_cpu(cm_id_priv->sq_psn);
                          switch (cm_id_priv->qp_type) {
                          case IB_QPT_RC:
                          case IB_QPT_XRC_INI:
                                  *qp_attr_mask |= IB_QP_RETRY_CNT | IB_QP_RNR_RETRY |
                                                   IB_QP_MAX_QP_RD_ATOMIC;
                                  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;
                                  /* fall through */
                          case IB_QPT_XRC_TGT:
                                  *qp_attr_mask |= IB_QP_TIMEOUT;
                                  qp_attr->timeout = cm_id_priv->av.timeout;
                                  break;
                          default:
                                  break;
                          }
                          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;
                          }
                  } else {
                          *qp_attr_mask = IB_QP_ALT_PATH | IB_QP_PATH_MIG_STATE;
                          qp_attr->alt_port_num = cm_id_priv->alt_av.port->port_num;
                          qp_attr->alt_pkey_index = cm_id_priv->alt_av.pkey_index;
                          qp_attr->alt_timeout = cm_id_priv->alt_av.timeout;
                          qp_attr->alt_ah_attr = cm_id_priv->alt_av.ah_attr;
                          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 ssize_t cm_show_counter(struct kobject *obj, struct attribute *attr,
                                 char *buf)
  {
          struct cm_counter_group *group;
          struct cm_counter_attribute *cm_attr;
  
          group = container_of(obj, struct cm_counter_group, obj);
          cm_attr = container_of(attr, struct cm_counter_attribute, attr);
  
          return sprintf(buf, "%ld\n",
                         atomic_long_read(&group->counter[cm_attr->index]));
  }
  
  static const struct sysfs_ops cm_counter_ops = {
          .show = cm_show_counter
  };
  
  static struct kobj_type cm_counter_obj_type = {
          .sysfs_ops = &cm_counter_ops,
          .default_attrs = cm_counter_default_attrs
  };
  
  static char *cm_devnode(struct device *dev, umode_t *mode)
  {
          if (mode)
                  *mode = 0666;
          return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
  }
  
  struct class cm_class = {
          .owner   = THIS_MODULE,
          .name    = "infiniband_cm",
          .devnode = cm_devnode,
  };
  EXPORT_SYMBOL(cm_class);
  
  static int cm_create_port_fs(struct cm_port *port)
  {
          int i, ret;
  
          for (i = 0; i < CM_COUNTER_GROUPS; i++) {
                  ret = ib_port_register_module_stat(port->cm_dev->ib_device,
                                                     port->port_num,
                                                     &port->counter_group[i].obj,
                                                     &cm_counter_obj_type,
                                                     counter_group_names[i]);
                  if (ret)
                          goto error;
          }
  
          return 0;
  
  error:
          while (i--)
                  ib_port_unregister_module_stat(&port->counter_group[i].obj);
          return ret;
  
  }
  
  static void cm_remove_port_fs(struct cm_port *port)
  {
          int i;
  
          for (i = 0; i < CM_COUNTER_GROUPS; i++)
                  ib_port_unregister_module_stat(&port->counter_group[i].obj);
  
  }
  
  static void cm_add_one(struct ib_device *ib_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;
          int count = 0;
          u8 i;
  
          cm_dev = kzalloc(sizeof(*cm_dev) + sizeof(*port) *
                           ib_device->phys_port_cnt, GFP_KERNEL);
          if (!cm_dev)
                  return;
  
          cm_dev->ib_device = ib_device;
          cm_dev->ack_delay = ib_device->attrs.local_ca_ack_delay;
          cm_dev->going_down = 0;
  
          set_bit(IB_MGMT_METHOD_SEND, reg_req.method_mask);
          for (i = 1; i <= ib_device->phys_port_cnt; i++) {
                  if (!rdma_cap_ib_cm(ib_device, i))
                          continue;
  
                  port = kzalloc(sizeof *port, GFP_KERNEL);
                  if (!port)
                          goto error1;
  
                  cm_dev->port[i-1] = port;
                  port->cm_dev = cm_dev;
                  port->port_num = i;
  
                  INIT_LIST_HEAD(&port->cm_priv_prim_list);
                  INIT_LIST_HEAD(&port->cm_priv_altr_list);
  
                  ret = cm_create_port_fs(port);
                  if (ret)
                          goto error1;
  
                  port->mad_agent = ib_register_mad_agent(ib_device, i,
                                                          IB_QPT_GSI,
                                                          &reg_req,
                                                          0,
                                                          cm_send_handler,
                                                          cm_recv_handler,
                                                          port,
                                                          0);
                  if (IS_ERR(port->mad_agent))
                          goto error2;
  
                  ret = ib_modify_port(ib_device, i, 0, &port_modify);
                  if (ret)
                          goto error3;
  
                  count++;
          }
  
          if (!count)
                  goto free;
  
          ib_set_client_data(ib_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;
  
  error3:
          ib_unregister_mad_agent(port->mad_agent);
  error2:
          cm_remove_port_fs(port);
  error1:
          port_modify.set_port_cap_mask = 0;
          port_modify.clr_port_cap_mask = IB_PORT_CM_SUP;
          kfree(port);
          while (--i) {
                  if (!rdma_cap_ib_cm(ib_device, i))
                          continue;
  
                  port = cm_dev->port[i-1];
                  ib_modify_port(ib_device, port->port_num, 0, &port_modify);
                  ib_unregister_mad_agent(port->mad_agent);
                  cm_remove_port_fs(port);
                  kfree(port);
          }
  free:
          kfree(cm_dev);
  }
  
  static void cm_remove_one(struct ib_device *ib_device, void *client_data)
  {
          struct cm_device *cm_dev = client_data;
          struct cm_port *port;
          struct cm_id_private *cm_id_priv;
          struct ib_mad_agent *cur_mad_agent;
          struct ib_port_modify port_modify = {
                  .clr_port_cap_mask = IB_PORT_CM_SUP
          };
          unsigned long flags;
          int i;
  
          if (!cm_dev)
                  return;
  
          write_lock_irqsave(&cm.device_lock, flags);
          list_del(&cm_dev->list);
          write_unlock_irqrestore(&cm.device_lock, flags);
  
          spin_lock_irq(&cm.lock);
          cm_dev->going_down = 1;
          spin_unlock_irq(&cm.lock);
  
          for (i = 1; i <= ib_device->phys_port_cnt; i++) {
                  if (!rdma_cap_ib_cm(ib_device, i))
                          continue;
  
                  port = cm_dev->port[i-1];
                  ib_modify_port(ib_device, port->port_num, 0, &port_modify);
                  /* Mark all the cm_id's as not valid */
                  spin_lock_irq(&cm.lock);
                  list_for_each_entry(cm_id_priv, &port->cm_priv_altr_list, altr_list)
                          cm_id_priv->altr_send_port_not_ready = 1;
                  list_for_each_entry(cm_id_priv, &port->cm_priv_prim_list, prim_list)
                          cm_id_priv->prim_send_port_not_ready = 1;
                  spin_unlock_irq(&cm.lock);
                  /*
                   * We flush the queue here after the going_down set, this
                   * verify that no new works will be queued in the recv handler,
                   * after that we can call the unregister_mad_agent
                   */
                  flush_workqueue(cm.wq);
                  spin_lock_irq(&cm.state_lock);
                  cur_mad_agent = port->mad_agent;
                  port->mad_agent = NULL;
                  spin_unlock_irq(&cm.state_lock);
                  ib_unregister_mad_agent(cur_mad_agent);
                  cm_remove_port_fs(port);
                  kfree(port);
          }
  
          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);
          spin_lock_init(&cm.state_lock);
          cm.listen_service_table = RB_ROOT;
          cm.listen_service_id = 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);
          get_random_bytes(&cm.random_id_operand, sizeof cm.random_id_operand);
          INIT_LIST_HEAD(&cm.timewait_list);
  
          ret = class_register(&cm_class);
          if (ret) {
                  ret = -ENOMEM;
                  goto error1;
          }
  
          cm.wq = create_workqueue("ib_cm");
          if (!cm.wq) {
                  ret = -ENOMEM;
                  goto error2;
          }
  
          ret = ib_register_client(&cm_client);
          if (ret)
                  goto error3;
  
          return 0;
  error3:
          destroy_workqueue(cm.wq);
  error2:
          class_unregister(&cm_class);
  error1:
          idr_destroy(&cm.local_id_table);
          return ret;
  }
  
  static void __exit ib_cm_cleanup(void)
  {
          struct cm_timewait_info *timewait_info, *tmp;
  
          spin_lock_irq(&cm.lock);
          list_for_each_entry(timewait_info, &cm.timewait_list, list)
                  cancel_delayed_work(&timewait_info->work.work);
          spin_unlock_irq(&cm.lock);
  
          ib_unregister_client(&cm_client);
          destroy_workqueue(cm.wq);
  
          list_for_each_entry_safe(timewait_info, tmp, &cm.timewait_list, list) {
                  cancel_delayed_work_sync(&timewait_info->work.work);
                  list_del(&timewait_info->list);
                  kfree(timewait_info);
          }
  
          class_unregister(&cm_class);
          idr_destroy(&cm.local_id_table);
  }
  
  module_init_order(ib_cm_init, SI_ORDER_SECOND);
  module_exit_order(ib_cm_cleanup, SI_ORDER_SECOND);