cm.c

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

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

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

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

static struct ib_cm {
    spinlock_t lock;
    struct list_head device_list;
    rwlock_t device_lock;
    struct rb_root listen_service_table;
    u64 listen_service_id;
    /* struct rb_root peer_service_table; todo: fix peer to peer */
    struct rb_root remote_qp_table;
    struct rb_root remote_id_table;
    struct rb_root remote_sidr_table;
    struct idr local_id_table;
    __be32 random_id_operand;
    struct list_head timewait_list;
    struct workqueue_struct *wq;
} 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 cm_counter_group counter_group[CM_COUNTER_GROUPS];
};

struct cm_device {
    struct list_head list;
    struct ib_device *ib_device;
    struct device *device;
    u8 ack_delay;
    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;

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

    void *private_data;
    __be64 tid;
    __be32 local_qpn;
    __be32 remote_qpn;
    enum ib_qp_type qp_type;
    __be32 sq_psn;
    __be32 rq_psn;
    int timeout_ms;
    enum ib_mtu path_mtu;
    __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 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;

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

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

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

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

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

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

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

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

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

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

    data = 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 void cm_init_av_for_response(struct cm_port *port, struct ib_wc *wc,
                    struct ib_grh *grh, struct cm_av *av)
{
    av->port = port;
    av->pkey_index = wc->pkey_index;
    ib_init_ah_from_wc(port->cm_dev->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_device *cm_dev;
    struct cm_port *port = NULL;
    unsigned long flags;
    int ret;
    u8 p;

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

    if (!port)
        return -EINVAL;

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

    av->port = port;
    ib_init_ah_from_path(cm_dev->ib_device, port->port_num, path,
                 &av->ah_attr);
    av->timeout = path->packet_life_time + 1;
    return 0;
}

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

    do {
        spin_lock_irqsave(&cm.lock, flags);
        ret = idr_get_new_above(&cm.local_id_table, cm_id_priv,
                    next_id, &id);
        if (!ret)
            next_id = ((unsigned) id + 1) & MAX_IDR_MASK;
        spin_unlock_irqrestore(&cm.lock, flags);
    } while( (ret == -EAGAIN) && idr_pre_get(&cm.local_id_table, GFP_KERNEL) );

    cm_id_priv->id.local_id = (__force __be32)id ^ cm.random_id_operand;
    return ret;
}

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;
}

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

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

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

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

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

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

    if (!dst_data)
        return 0;

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

/*
 * 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;
    int data_cmp;

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

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

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

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

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

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

    while (*link) {
        parent = *link;
        cur_timewait_info = rb_entry(parent, struct cm_timewait_info,
                         remote_id_node);
        if (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);
    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;

    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);
    queue_delayed_work(cm.wq, &cm_id_priv->timewait_info->work.work,
               msecs_to_jiffies(wait_time));
    cm_id_priv->timewait_info = NULL;
}

static void cm_reset_to_idle(struct cm_id_private *cm_id_priv)
{
    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:
        cm_id->state = IB_CM_IDLE;
        spin_unlock_irq(&cm_id_priv->lock);
        spin_lock_irq(&cm.lock);
        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);
        break;
    case IB_CM_REQ_SENT:
        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_MRA_REQ_RCVD:
    case IB_CM_REP_SENT:
    case IB_CM_MRA_REP_RCVD:
        ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
        /* Fall through */
    case IB_CM_MRA_REQ_SENT:
    case IB_CM_REP_RCVD:
    case IB_CM_MRA_REP_SENT:
        spin_unlock_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;
    }

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

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

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

    service_mask = service_mask ? service_mask : ~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;

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

    cm_id->state = IB_CM_LISTEN;

    spin_lock_irqsave(&cm.lock, flags);
    if (service_id == IB_CM_ASSIGN_SERVICE_ID) {
        cm_id->service_id = cpu_to_be64(cm.listen_service_id++);
        cm_id->service_mask = ~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);
    spin_unlock_irqrestore(&cm.lock, flags);

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

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

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

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

static void cm_format_req(struct cm_req_msg *req_msg,
              struct cm_id_private *cm_id_priv,
              struct ib_cm_req_param *param)
{
    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, CM_MSG_SEQUENCE_REQ));

    req_msg->local_comm_id = cm_id_priv->id.local_id;
    req_msg->service_id = param->service_id;
    req_msg->local_ca_guid = cm_id_priv->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);
    if (ret)
        goto error1;
    if (param->alternate_path) {
        ret = cm_init_av_by_path(param->alternate_path,
                     &cm_id_priv->alt_av);
        if (ret)
            goto error1;
    }
    cm_id->service_id = param->service_id;
    cm_id->service_mask = ~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 inline int cm_is_active_peer(__be64 local_ca_guid, __be64 remote_ca_guid,
                    __be32 local_qpn, __be32 remote_qpn)
{
    return (be64_to_cpu(local_ca_guid) > be64_to_cpu(remote_ca_guid) ||
        ((local_ca_guid == remote_ca_guid) &&
         (be32_to_cpu(local_qpn) > be32_to_cpu(remote_qpn))));
}

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

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

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

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

static void cm_process_work(struct cm_id_private *cm_id_priv,
                struct cm_work *work)
{
    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;

    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);
        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);
        return NULL;
    }

    /* Find matching listen request. */
    listen_cm_id_priv = cm_find_listen(cm_id_priv->id.device,
                       req_msg->service_id,
                       req_msg->private_data);
    if (!listen_cm_id_priv) {
        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;
    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;
    cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
                work->mad_recv_wc->recv_buf.grh,
                &cm_id_priv->av);
    cm_id_priv->timewait_info = cm_create_timewait_info(cm_id_priv->
                                id.local_id);
    if (IS_ERR(cm_id_priv->timewait_info)) {
        ret = PTR_ERR(cm_id_priv->timewait_info);
        goto 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;
        kfree(cm_id_priv->timewait_info);
        goto destroy;
    }

    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]);
    ret = cm_init_av_by_path(&work->path[0], &cm_id_priv->av);
    if (ret) {
        ib_get_cached_gid(work->port->cm_dev->ib_device,
                  work->port->port_num, 0, &work->path[0].sgid);
        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);
        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);
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;

    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. */
    if (cm_insert_remote_qpn(cm_id_priv->timewait_info)) {
        rb_erase(&cm_id_priv->timewait_info->remote_id_node,
             &cm.remote_id_table);
        cm_id_priv->timewait_info->inserted_remote_id = 0;
        spin_unlock(&cm.lock);
        spin_unlock_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;
        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, CM_MSG_SEQUENCE_DREQ));
    dreq_msg->local_comm_id = cm_id_priv->id.local_id;
    dreq_msg->remote_comm_id = cm_id_priv->id.remote_id;
    cm_dreq_set_remote_qpn(dreq_msg, cm_id_priv->remote_qpn);

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

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

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

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

    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]);
        if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
            goto unlock;

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

        if (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, CM_MSG_SEQUENCE_LAP));
    lap_msg->local_comm_id = cm_id_priv->id.local_id;
    lap_msg->remote_comm_id = cm_id_priv->id.remote_id;
    cm_lap_set_remote_qpn(lap_msg, cm_id_priv->remote_qpn);
    /* todo: need remote CM response timeout */
    cm_lap_set_remote_resp_timeout(lap_msg, 0x1F);
    lap_msg->alt_local_lid = alternate_path->slid;
    lap_msg->alt_remote_lid = alternate_path->dlid;
    lap_msg->alt_local_gid = alternate_path->sgid;
    lap_msg->alt_remote_gid = alternate_path->dgid;
    cm_lap_set_flow_label(lap_msg, alternate_path->flow_label);
    cm_lap_set_traffic_class(lap_msg, alternate_path->traffic_class);
    lap_msg->alt_hop_limit = alternate_path->hop_limit;
    cm_lap_set_packet_rate(lap_msg, alternate_path->rate);
    cm_lap_set_sl(lap_msg, alternate_path->sl);
    cm_lap_set_subnet_local(lap_msg, 1); /* local only... */
    cm_lap_set_local_ack_timeout(lap_msg,
        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);
    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;

    /* 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]);
        if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
            goto unlock;

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

        if (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;
    cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
                work->mad_recv_wc->recv_buf.grh,
                &cm_id_priv->av);
    cm_init_av_by_path(param->alternate_path, &cm_id_priv->alt_av);
    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;

    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, CM_MSG_SEQUENCE_SIDR));
    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);
    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,
                     struct ib_cm_id *listen_id)
{
    struct cm_sidr_req_msg *sidr_req_msg;
    struct ib_cm_sidr_req_event_param *param;

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

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

    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;
    cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
                work->mad_recv_wc->recv_buf.grh,
                &cm_id_priv->av);
    cm_id_priv->id.remote_id = sidr_req_msg->request_id;
    cm_id_priv->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,
                    sidr_req_msg->private_data);
    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, &cur_cm_id_priv->id);
    cm_process_work(cm_id_priv, work);
    cm_deref_id(cur_cm_id_priv);
    return 0;
out:
    ib_destroy_cm_id(&cm_id_priv->id);
    return -EINVAL;
}

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

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

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

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

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

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

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

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

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

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

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

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

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

    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;

    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;
    queue_delayed_work(cm.wq, &work->work, 0);
out:
    return ret;
}

static int cm_migrate(struct ib_cm_id *cm_id)
{
    struct cm_id_private *cm_id_priv;
    unsigned long flags;
    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;
        cm_id_priv->av = cm_id_priv->alt_av;
    } 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_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;

    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;
    queue_delayed_work(cm.wq, &work->work, 0);
}

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 void cm_get_ack_delay(struct cm_device *cm_dev)
{
    struct ib_device_attr attr;

    if (ib_query_device(cm_dev->ib_device, &attr))
        cm_dev->ack_delay = 0; /* acks will rely on packet life time */
    else
        cm_dev->ack_delay = attr.local_ca_ack_delay;
}

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 void cm_release_port_obj(struct kobject *obj)
{
    struct cm_port *cm_port;

    cm_port = container_of(obj, struct cm_port, port_obj);
    kfree(cm_port);
}

static struct kobj_type cm_port_obj_type = {
    .release = cm_release_port_obj
};

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;

    ret = kobject_init_and_add(&port->port_obj, &cm_port_obj_type,
                   &port->cm_dev->device->kobj,
                   "%d", port->port_num);
    if (ret) {
        kfree(port);
        return ret;
    }

    for (i = 0; i < CM_COUNTER_GROUPS; i++) {
        ret = kobject_init_and_add(&port->counter_group[i].obj,
                       &cm_counter_obj_type,
                       &port->port_obj,
                       "%s", counter_group_names[i]);
        if (ret)
            goto error;
    }

    return 0;

error:
    while (i--)
        kobject_put(&port->counter_group[i].obj);
    kobject_put(&port->port_obj);
    return ret;

}

static void cm_remove_port_fs(struct cm_port *port)
{
    int i;

    for (i = 0; i < CM_COUNTER_GROUPS; i++)
        kobject_put(&port->counter_group[i].obj);

    kobject_put(&port->port_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;
    u8 i;

    if (rdma_node_get_transport(ib_device->node_type) != RDMA_TRANSPORT_IB)
        return;

    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_get_ack_delay(cm_dev);

    cm_dev->device = device_create(&cm_class, &ib_device->dev,
                       MKDEV(0, 0), NULL,
                       "%s", ib_device->name);
    if (IS_ERR(cm_dev->device)) {
        kfree(cm_dev);
        return;
    }

    set_bit(IB_MGMT_METHOD_SEND, reg_req.method_mask);
    for (i = 1; i <= ib_device->phys_port_cnt; i++) {
        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;

        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);
        if (IS_ERR(port->mad_agent))
            goto error2;

        ret = ib_modify_port(ib_device, i, 0, &port_modify);
        if (ret)
            goto error3;
    }
    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;
    while (--i) {
        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);
    }
    device_unregister(cm_dev->device);
    kfree(cm_dev);
}

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

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

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

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

static int __init ib_cm_init(void)
{
    int ret;

    memset(&cm, 0, sizeof cm);
    INIT_LIST_HEAD(&cm.device_list);
    rwlock_init(&cm.device_lock);
    spin_lock_init(&cm.lock);
    cm.listen_service_table = RB_ROOT;
    cm.listen_service_id = 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);
    idr_pre_get(&cm.local_id_table, GFP_KERNEL);
    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) {
        list_del(&timewait_info->list);
        kfree(timewait_info);
    }

    class_unregister(&cm_class);
    idr_destroy(&cm.local_id_table);
}

module_init(ib_cm_init);
module_exit(ib_cm_cleanup);