/*
 * 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/err.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/random.h>
#include <linux/rbtree.h>
#include <linux/spinlock.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_ID_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);
                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_resp_res(req_msg, param->responder_resources);
        cm_req_set_init_depth(req_msg, param->initiator_depth);
        cm_req_set_remote_resp_timeout(req_msg,
                                       param->remote_cm_response_timeout);
        cm_req_set_qp_type(req_msg, param->qp_type);
        cm_req_set_flow_ctrl(req_msg, param->flow_control);
        cm_req_set_starting_psn(req_msg, cpu_to_be32(param->starting_psn));
        cm_req_set_local_resp_timeout(req_msg,
                                      param->local_cm_response_timeout);
        cm_req_set_retry_count(req_msg, param->retry_count);
        req_msg->pkey = param->primary_path->pkey;
        cm_req_set_path_mtu(req_msg, param->primary_path->mtu);
        cm_req_set_rnr_retry_count(req_msg, param->rnr_retry_count);
        cm_req_set_max_cm_retries(req_msg, param->max_cm_retries);
        cm_req_set_srq(req_msg, param->srq);

        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)
                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_local_qpn(rep_msg, cpu_to_be32(param->qp_num));
        cm_rep_set_starting_psn(rep_msg, cpu_to_be32(param->starting_psn));
        rep_msg->resp_resources = param->responder_resources;
        rep_msg->initiator_depth = param->initiator_depth;
        cm_rep_set_target_ack_delay(rep_msg,
                                    cm_id_priv->av.port->cm_dev->ack_delay);
        cm_rep_set_failover(rep_msg, param->failover_accepted);
        cm_rep_set_flow_ctrl(rep_msg, param->flow_control);
        cm_rep_set_rnr_retry_count(rep_msg, param->rnr_retry_count);
        cm_rep_set_srq(rep_msg, param->srq);
        rep_msg->local_ca_guid = cm_id_priv->id.device->node_guid;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

static void cm_dup_rep_handler(struct cm_work *work)
{
        struct cm_id_private *cm_id_priv;
        struct cm_rep_msg *rep_msg;
        struct ib_mad_send_buf *msg = NULL;
        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);

        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_local_qpn(rep_msg);

        spin_lock(&cm.lock);
        /* Check for duplicate REP. */
        if (cm_insert_remote_id(cm_id_priv->timewait_info)) {
                spin_unlock(&cm.lock);
                spin_unlock_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_local_qpn(rep_msg);
        cm_id_priv->initiator_depth = rep_msg->resp_resources;
        cm_id_priv->responder_resources = rep_msg->initiator_depth;
        cm_id_priv->sq_psn = cm_rep_get_starting_psn(rep_msg);
        cm_id_priv->rnr_retry_count = cm_rep_get_rnr_retry_count(rep_msg);
        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;
        }

        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:
        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:
        case IB_CM_ESTABLISHED:
                cm_enter_timewait(cm_id_priv);
                break;
        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:
                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);
        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: