// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
 * 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.
 * Copyright (c) 2019, Mellanox Technologies inc.  All rights reserved.
 */

#include <linux/completion.h>
#include <linux/dma-mapping.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/random.h>
#include <linux/rbtree.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/workqueue.h>
#include <linux/kdev_t.h>
#include <linux/etherdevice.h>

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

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

static const char * const ibcm_rej_reason_strs[] = {
        [IB_CM_REJ_NO_QP]                       = "no QP",
        [IB_CM_REJ_NO_EEC]                      = "no EEC",
        [IB_CM_REJ_NO_RESOURCES]                = "no resources",
        [IB_CM_REJ_TIMEOUT]                     = "timeout",
        [IB_CM_REJ_UNSUPPORTED]                 = "unsupported",
        [IB_CM_REJ_INVALID_COMM_ID]             = "invalid comm ID",
        [IB_CM_REJ_INVALID_COMM_INSTANCE]       = "invalid comm instance",
        [IB_CM_REJ_INVALID_SERVICE_ID]          = "invalid service ID",
        [IB_CM_REJ_INVALID_TRANSPORT_TYPE]      = "invalid transport type",
        [IB_CM_REJ_STALE_CONN]                  = "stale conn",
        [IB_CM_REJ_RDC_NOT_EXIST]               = "RDC not exist",
        [IB_CM_REJ_INVALID_GID]                 = "invalid GID",
        [IB_CM_REJ_INVALID_LID]                 = "invalid LID",
        [IB_CM_REJ_INVALID_SL]                  = "invalid SL",
        [IB_CM_REJ_INVALID_TRAFFIC_CLASS]       = "invalid traffic class",
        [IB_CM_REJ_INVALID_HOP_LIMIT]           = "invalid hop limit",
        [IB_CM_REJ_INVALID_PACKET_RATE]         = "invalid packet rate",
        [IB_CM_REJ_INVALID_ALT_GID]             = "invalid alt GID",
        [IB_CM_REJ_INVALID_ALT_LID]             = "invalid alt LID",
        [IB_CM_REJ_INVALID_ALT_SL]              = "invalid alt SL",
        [IB_CM_REJ_INVALID_ALT_TRAFFIC_CLASS]   = "invalid alt traffic class",
        [IB_CM_REJ_INVALID_ALT_HOP_LIMIT]       = "invalid alt hop limit",
        [IB_CM_REJ_INVALID_ALT_PACKET_RATE]     = "invalid alt packet rate",
        [IB_CM_REJ_PORT_CM_REDIRECT]            = "port CM redirect",
        [IB_CM_REJ_PORT_REDIRECT]               = "port redirect",
        [IB_CM_REJ_INVALID_MTU]                 = "invalid MTU",
        [IB_CM_REJ_INSUFFICIENT_RESP_RESOURCES] = "insufficient resp resources",
        [IB_CM_REJ_CONSUMER_DEFINED]            = "consumer defined",
        [IB_CM_REJ_INVALID_RNR_RETRY]           = "invalid RNR retry",
        [IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID]     = "duplicate local comm ID",
        [IB_CM_REJ_INVALID_CLASS_VERSION]       = "invalid class version",
        [IB_CM_REJ_INVALID_FLOW_LABEL]          = "invalid flow label",
        [IB_CM_REJ_INVALID_ALT_FLOW_LABEL]      = "invalid alt flow label",
        [IB_CM_REJ_VENDOR_OPTION_NOT_SUPPORTED] =
                "vendor option is not supported",
};

const char *__attribute_const__ ibcm_reject_msg(int reason)
{
        size_t index = reason;

        if (index < ARRAY_SIZE(ibcm_rej_reason_strs) &&
            ibcm_rej_reason_strs[index])
                return ibcm_rej_reason_strs[index];
        else
                return "unrecognized reason";
}
EXPORT_SYMBOL(ibcm_reject_msg);

struct cm_id_private;
struct cm_work;
static int cm_add_one(struct ib_device *device);
static void cm_remove_one(struct ib_device *device, void *client_data);
static void cm_process_work(struct cm_id_private *cm_id_priv,
                            struct cm_work *work);
static int cm_send_sidr_rep_locked(struct cm_id_private *cm_id_priv,
                                   struct ib_cm_sidr_rep_param *param);
static int cm_send_dreq_locked(struct cm_id_private *cm_id_priv,
                               const void *private_data, u8 private_data_len);
static int cm_send_drep_locked(struct cm_id_private *cm_id_priv,
                               void *private_data, u8 private_data_len);
static int cm_send_rej_locked(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);

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 xarray local_id_table;
        u32 local_id_next;
        __be32 random_id_operand;
        struct list_head timewait_list;
        struct workqueue_struct *wq;
        /* Sync on cm change port state */
        spinlock_t state_lock;
} cm;

/* Counter indexes ordered by attribute ID */
enum {
        CM_REQ_COUNTER,
        CM_MRA_COUNTER,
        CM_REJ_COUNTER,
        CM_REP_COUNTER,
        CM_RTU_COUNTER,
        CM_DREQ_COUNTER,
        CM_DREP_COUNTER,
        CM_SIDR_REQ_COUNTER,
        CM_SIDR_REP_COUNTER,
        CM_LAP_COUNTER,
        CM_APR_COUNTER,
        CM_ATTR_COUNT,
        CM_ATTR_ID_OFFSET = 0x0010,
};

enum {
        CM_XMIT,
        CM_XMIT_RETRIES,
        CM_RECV,
        CM_RECV_DUPLICATES,
        CM_COUNTER_GROUPS
};

static char const counter_group_names[CM_COUNTER_GROUPS]
                                     [sizeof("cm_rx_duplicates")] = {
        "cm_tx_msgs", "cm_tx_retries",
        "cm_rx_msgs", "cm_rx_duplicates"
};

struct cm_counter_group {
        struct kobject obj;
        atomic_long_t counter[CM_ATTR_COUNT];
};

struct cm_counter_attribute {
        struct attribute attr;
        int index;
};

#define CM_COUNTER_ATTR(_name, _index) \
struct cm_counter_attribute cm_##_name##_counter_attr = { \
        .attr = { .name = __stringify(_name), .mode = 0444 }, \
        .index = _index \
}

static CM_COUNTER_ATTR(req, CM_REQ_COUNTER);
static CM_COUNTER_ATTR(mra, CM_MRA_COUNTER);
static CM_COUNTER_ATTR(rej, CM_REJ_COUNTER);
static CM_COUNTER_ATTR(rep, CM_REP_COUNTER);
static CM_COUNTER_ATTR(rtu, CM_RTU_COUNTER);
static CM_COUNTER_ATTR(dreq, CM_DREQ_COUNTER);
static CM_COUNTER_ATTR(drep, CM_DREP_COUNTER);
static CM_COUNTER_ATTR(sidr_req, CM_SIDR_REQ_COUNTER);
static CM_COUNTER_ATTR(sidr_rep, CM_SIDR_REP_COUNTER);
static CM_COUNTER_ATTR(lap, CM_LAP_COUNTER);
static CM_COUNTER_ATTR(apr, CM_APR_COUNTER);

static struct attribute *cm_counter_default_attrs[] = {
        &cm_req_counter_attr.attr,
        &cm_mra_counter_attr.attr,
        &cm_rej_counter_attr.attr,
        &cm_rep_counter_attr.attr,
        &cm_rtu_counter_attr.attr,
        &cm_dreq_counter_attr.attr,
        &cm_drep_counter_attr.attr,
        &cm_sidr_req_counter_attr.attr,
        &cm_sidr_rep_counter_attr.attr,
        &cm_lap_counter_attr.attr,
        &cm_apr_counter_attr.attr,
        NULL
};

struct cm_port {
        struct cm_device *cm_dev;
        struct ib_mad_agent *mad_agent;
        struct kobject port_obj;
        u8 port_num;
        struct list_head cm_priv_prim_list;
        struct list_head cm_priv_altr_list;
        struct cm_counter_group counter_group[CM_COUNTER_GROUPS];
};

struct cm_device {
        struct list_head list;
        struct ib_device *ib_device;
        u8 ack_delay;
        int going_down;
        struct cm_port *port[];
};

struct cm_av {
        struct cm_port *port;
        union ib_gid dgid;
        struct rdma_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 sa_path_rec path[];
};

struct cm_timewait_info {
        struct cm_work work;
        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;
        refcount_t refcount;
        /* Number of clients sharing this ib_cm_id. Only valid for listeners.
         * Protected by the cm.lock spinlock. */
        int listen_sharecount;
        struct rcu_head rcu;

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

        void *private_data;
        __be64 tid;
        __be32 local_qpn;
        __be32 remote_qpn;
        enum ib_qp_type qp_type;
        __be32 sq_psn;
        __be32 rq_psn;
        int timeout_ms;
        enum ib_mtu path_mtu;
        __be16 pkey;
        u8 private_data_len;
        u8 max_cm_retries;
        u8 responder_resources;
        u8 initiator_depth;
        u8 retry_count;
        u8 rnr_retry_count;
        u8 service_timeout;
        u8 target_ack_delay;

        struct list_head prim_list;
        struct list_head altr_list;
        /* Indicates that the send port mad is registered and av is set */
        int prim_send_port_not_ready;
        int altr_send_port_not_ready;

        struct list_head work_list;
        atomic_t work_count;

        struct rdma_ucm_ece ece;
};

static void cm_work_handler(struct work_struct *work);

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

static int cm_alloc_msg(struct cm_id_private *cm_id_priv,
                        struct ib_mad_send_buf **msg)
{
        struct ib_mad_agent *mad_agent;
        struct ib_mad_send_buf *m;
        struct ib_ah *ah;
        struct cm_av *av;
        unsigned long flags, flags2;
        int ret = 0;

        /* don't let the port to be released till the agent is down */
        spin_lock_irqsave(&cm.state_lock, flags2);
        spin_lock_irqsave(&cm.lock, flags);
        if (!cm_id_priv->prim_send_port_not_ready)
                av = &cm_id_priv->av;
        else if (!cm_id_priv->altr_send_port_not_ready &&
                 (cm_id_priv->alt_av.port))
                av = &cm_id_priv->alt_av;
        else {
                pr_info("%s: not valid CM id\n", __func__);
                ret = -ENODEV;
                spin_unlock_irqrestore(&cm.lock, flags);
                goto out;
        }
        spin_unlock_irqrestore(&cm.lock, flags);
        /* Make sure the port haven't released the mad yet */
        mad_agent = cm_id_priv->av.port->mad_agent;
        if (!mad_agent) {
                pr_info("%s: not a valid MAD agent\n", __func__);
                ret = -ENODEV;
                goto out;
        }
        ah = rdma_create_ah(mad_agent->qp->pd, &av->ah_attr, 0);
        if (IS_ERR(ah)) {
                ret = PTR_ERR(ah);
                goto out;
        }

        m = ib_create_send_mad(mad_agent, cm_id_priv->id.remote_cm_qpn,
                               av->pkey_index,
                               0, IB_MGMT_MAD_HDR, IB_MGMT_MAD_DATA,
                               GFP_ATOMIC,
                               IB_MGMT_BASE_VERSION);
        if (IS_ERR(m)) {
                rdma_destroy_ah(ah, 0);
                ret = PTR_ERR(m);
                goto out;
        }

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

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

out:
        spin_unlock_irqrestore(&cm.state_lock, flags2);
        return ret;
}

static struct ib_mad_send_buf *cm_alloc_response_msg_no_ah(struct cm_port *port,
                                                           struct ib_mad_recv_wc *mad_recv_wc)
{
        return ib_create_send_mad(port->mad_agent, 1, mad_recv_wc->wc->pkey_index,
                                  0, IB_MGMT_MAD_HDR, IB_MGMT_MAD_DATA,
                                  GFP_ATOMIC,
                                  IB_MGMT_BASE_VERSION);
}

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

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

        msg->ah = ah;
        return 0;
}

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

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

        m = cm_alloc_response_msg_no_ah(port, mad_recv_wc);
        if (IS_ERR(m))
                return PTR_ERR(m);

        ret = cm_create_response_msg_ah(port, mad_recv_wc, m);
        if (ret) {
                cm_free_msg(m);
                return ret;
        }

        *msg = m;
        return 0;
}

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

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

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

        return data;
}

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

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

static int cm_init_av_for_lap(struct cm_port *port, struct ib_wc *wc,
                              struct ib_grh *grh, struct cm_av *av)
{
        struct rdma_ah_attr new_ah_attr;
        int ret;

        av->port = port;
        av->pkey_index = wc->pkey_index;

        /*
         * av->ah_attr might be initialized based on past wc during incoming
         * connect request or while sending out connect request. So initialize
         * a new ah_attr on stack. If initialization fails, old ah_attr is
         * used for sending any responses. If initialization is successful,
         * than new ah_attr is used by overwriting old one.
         */
        ret = ib_init_ah_attr_from_wc(port->cm_dev->ib_device,
                                      port->port_num, wc,
                                      grh, &new_ah_attr);
        if (ret)
                return ret;

        rdma_move_ah_attr(&av->ah_attr, &new_ah_attr);
        return 0;
}

static int cm_init_av_for_response(struct cm_port *port, struct ib_wc *wc,
                                   struct ib_grh *grh, struct cm_av *av)
{
        av->port = port;
        av->pkey_index = wc->pkey_index;
        return ib_init_ah_attr_from_wc(port->cm_dev->ib_device,
                                       port->port_num, wc,
                                       grh, &av->ah_attr);
}

static void add_cm_id_to_port_list(struct cm_id_private *cm_id_priv,
                                   struct cm_av *av, struct cm_port *port)
{
        unsigned long flags;

        spin_lock_irqsave(&cm.lock, flags);
        if (&cm_id_priv->av == av)
                list_add_tail(&cm_id_priv->prim_list, &port->cm_priv_prim_list);
        else if (&cm_id_priv->alt_av == av)
                list_add_tail(&cm_id_priv->altr_list, &port->cm_priv_altr_list);
        else
                WARN_ON(true);
        spin_unlock_irqrestore(&cm.lock, flags);
}

static struct cm_port *
get_cm_port_from_path(struct sa_path_rec *path, const struct ib_gid_attr *attr)
{
        struct cm_device *cm_dev;
        struct cm_port *port = NULL;
        unsigned long flags;

        if (attr) {
                read_lock_irqsave(&cm.device_lock, flags);
                list_for_each_entry(cm_dev, &cm.device_list, list) {
                        if (cm_dev->ib_device == attr->device) {
                                port = cm_dev->port[attr->port_num - 1];
                                break;
                        }
                }
                read_unlock_irqrestore(&cm.device_lock, flags);
        } else {
                /* SGID attribute can be NULL in following
                 * conditions.
                 * (a) Alternative path
                 * (b) IB link layer without GRH
                 * (c) LAP send messages
                 */
                read_lock_irqsave(&cm.device_lock, flags);
                list_for_each_entry(cm_dev, &cm.device_list, list) {
                        attr = rdma_find_gid(cm_dev->ib_device,
                                             &path->sgid,
                                             sa_conv_pathrec_to_gid_type(path),
                                             NULL);
                        if (!IS_ERR(attr)) {
                                port = cm_dev->port[attr->port_num - 1];
                                break;
                        }
                }
                read_unlock_irqrestore(&cm.device_lock, flags);
                if (port)
                        rdma_put_gid_attr(attr);
        }
        return port;
}

static int cm_init_av_by_path(struct sa_path_rec *path,
                              const struct ib_gid_attr *sgid_attr,
                              struct cm_av *av,
                              struct cm_id_private *cm_id_priv)
{
        struct rdma_ah_attr new_ah_attr;
        struct cm_device *cm_dev;
        struct cm_port *port;
        int ret;

        port = get_cm_port_from_path(path, sgid_attr);
        if (!port)
                return -EINVAL;
        cm_dev = port->cm_dev;

        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;

        /*
         * av->ah_attr might be initialized based on wc or during
         * request processing time which might have reference to sgid_attr.
         * So initialize a new ah_attr on stack.
         * If initialization fails, old ah_attr is used for sending any
         * responses. If initialization is successful, than new ah_attr
         * is used by overwriting the old one. So that right ah_attr
         * can be used to return an error response.
         */
        ret = ib_init_ah_attr_from_path(cm_dev->ib_device, port->port_num, path,
                                        &new_ah_attr, sgid_attr);
        if (ret)
                return ret;

        av->timeout = path->packet_life_time + 1;
        add_cm_id_to_port_list(cm_id_priv, av, port);
        rdma_move_ah_attr(&av->ah_attr, &new_ah_attr);
        return 0;
}

static u32 cm_local_id(__be32 local_id)
{
        return (__force u32) (local_id ^ cm.random_id_operand);
}

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

        rcu_read_lock();
        cm_id_priv = xa_load(&cm.local_id_table, cm_local_id(local_id));
        if (!cm_id_priv || cm_id_priv->id.remote_id != remote_id ||
            !refcount_inc_not_zero(&cm_id_priv->refcount))
                cm_id_priv = NULL;
        rcu_read_unlock();

        return cm_id_priv;
}

/*
 * Trivial helpers to strip endian annotation and compare; the
 * endianness doesn't actually matter since we just need a stable
 * order for the RB tree.
 */
static int be32_lt(__be32 a, __be32 b)
{
        return (__force u32) a < (__force u32) b;
}

static int be32_gt(__be32 a, __be32 b)
{
        return (__force u32) a > (__force u32) b;
}

static int be64_lt(__be64 a, __be64 b)
{
        return (__force u64) a < (__force u64) b;
}

static int be64_gt(__be64 a, __be64 b)
{
        return (__force u64) a > (__force u64) b;
}

/*
 * Inserts a new cm_id_priv into the listen_service_table. Returns cm_id_priv
 * if the new ID was inserted, NULL if it could not be inserted due to a
 * collision, or the existing cm_id_priv ready for shared usage.
 */
static struct cm_id_private *cm_insert_listen(struct cm_id_private *cm_id_priv,
                                              ib_cm_handler shared_handler)
{
        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;
        unsigned long flags;

        spin_lock_irqsave(&cm.lock, flags);
        while (*link) {
                parent = *link;
                cur_cm_id_priv = rb_entry(parent, struct cm_id_private,
                                          service_node);
                if ((cur_cm_id_priv->id.service_mask & service_id) ==
                    (service_mask & cur_cm_id_priv->id.service_id) &&
                    (cm_id_priv->id.device == cur_cm_id_priv->id.device)) {
                        /*
                         * Sharing an ib_cm_id with different handlers is not
                         * supported
                         */
                        if (cur_cm_id_priv->id.cm_handler != shared_handler ||
                            cur_cm_id_priv->id.context ||
                            WARN_ON(!cur_cm_id_priv->id.cm_handler)) {
                                spin_unlock_irqrestore(&cm.lock, flags);
                                return NULL;
                        }
                        refcount_inc(&cur_cm_id_priv->refcount);
                        cur_cm_id_priv->listen_sharecount++;
                        spin_unlock_irqrestore(&cm.lock, flags);
                        return cur_cm_id_priv;
                }

                if (cm_id_priv->id.device < cur_cm_id_priv->id.device)
                        link = &(*link)->rb_left;
                else if (cm_id_priv->id.device > cur_cm_id_priv->id.device)
                        link = &(*link)->rb_right;
                else if (be64_lt(service_id, cur_cm_id_priv->id.service_id))
                        link = &(*link)->rb_left;
                else if (be64_gt(service_id, cur_cm_id_priv->id.service_id))
                        link = &(*link)->rb_right;
                else
                        link = &(*link)->rb_right;
        }
        cm_id_priv->listen_sharecount++;
        rb_link_node(&cm_id_priv->service_node, parent, link);
        rb_insert_color(&cm_id_priv->service_node, &cm.listen_service_table);
        spin_unlock_irqrestore(&cm.lock, flags);
        return cm_id_priv;
}

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

        while (node) {
                cm_id_priv = rb_entry(node, struct cm_id_private, service_node);
                if ((cm_id_priv->id.service_mask & service_id) ==
                     cm_id_priv->id.service_id &&
                    (cm_id_priv->id.device == device)) {
                        refcount_inc(&cm_id_priv->refcount);
                        return cm_id_priv;
                }
                if (device < cm_id_priv->id.device)
                        node = node->rb_left;
                else if (device > cm_id_priv->id.device)
                        node = node->rb_right;
                else if (be64_lt(service_id, cm_id_priv->id.service_id))
                        node = node->rb_left;
                else if (be64_gt(service_id, cm_id_priv->id.service_id))
                        node = node->rb_right;
                else
                        node = node->rb_right;
        }
        return NULL;
}

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

        while (*link) {
                parent = *link;
                cur_timewait_info = rb_entry(parent, struct cm_timewait_info,
                                             remote_id_node);
                if (be32_lt(remote_id, cur_timewait_info->work.remote_id))
                        link = &(*link)->rb_left;
                else if (be32_gt(remote_id, cur_timewait_info->work.remote_id))
                        link = &(*link)->rb_right;
                else if (be64_lt(remote_ca_guid, cur_timewait_info->remote_ca_guid))
                        link = &(*link)->rb_left;
                else if (be64_gt(remote_ca_guid, cur_timewait_info->remote_ca_guid))
                        link = &(*link)->rb_right;
                else
                        return cur_timewait_info;
        }
        timewait_info->inserted_remote_id = 1;
        rb_link_node(&timewait_info->remote_id_node, parent, link);
        rb_insert_color(&timewait_info->remote_id_node, &cm.remote_id_table);
        return NULL;
}

static struct cm_id_private *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;
        struct cm_id_private *res = NULL;

        spin_lock_irq(&cm.lock);
        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 {
                        res = cm_acquire_id(timewait_info->work.local_id,
                                             timewait_info->work.remote_id);
                        break;
                }
        }
        spin_unlock_irq(&cm.lock);
        return res;
}

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 struct cm_id_private *cm_alloc_id_priv(struct ib_device *device,
                                              ib_cm_handler cm_handler,
                                              void *context)
{
        struct cm_id_private *cm_id_priv;
        u32 id;
        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;

        RB_CLEAR_NODE(&cm_id_priv->service_node);
        RB_CLEAR_NODE(&cm_id_priv->sidr_id_node);
        spin_lock_init(&cm_id_priv->lock);
        init_completion(&cm_id_priv->comp);
        INIT_LIST_HEAD(&cm_id_priv->work_list);
        INIT_LIST_HEAD(&cm_id_priv->prim_list);
        INIT_LIST_HEAD(&cm_id_priv->altr_list);
        atomic_set(&cm_id_priv->work_count, -1);
        refcount_set(&cm_id_priv->refcount, 1);

        ret = xa_alloc_cyclic_irq(&cm.local_id_table, &id, NULL, xa_limit_32b,
                                  &cm.local_id_next, GFP_KERNEL);
        if (ret < 0)
                goto error;
        cm_id_priv->id.local_id = (__force __be32)id ^ cm.random_id_operand;

        return cm_id_priv;

error:
        kfree(cm_id_priv);
        return ERR_PTR(ret);
}

/*
 * Make the ID visible to the MAD handlers and other threads that use the
 * xarray.
 */
static void cm_finalize_id(struct cm_id_private *cm_id_priv)
{
        xa_store_irq(&cm.local_id_table, cm_local_id(cm_id_priv->id.local_id),
                     cm_id_priv, GFP_KERNEL);
}

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;

        cm_id_priv = cm_alloc_id_priv(device, cm_handler, context);
        if (IS_ERR(cm_id_priv))
                return ERR_CAST(cm_id_priv);

        cm_finalize_id(cm_id_priv);
        return &cm_id_priv->id;
}
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 void cm_queue_work_unlock(struct cm_id_private *cm_id_priv,
                                 struct cm_work *work)
        __releases(&cm_id_priv->lock)
{
        bool immediate;

        /*
         * To deliver the event to the user callback we have the drop the
         * spinlock, however, we need to ensure that the user callback is single
         * threaded and receives events in the temporal order. If there are
         * already events being processed then thread new events onto a list,
         * the thread currently processing will pick them up.
         */
        immediate = atomic_inc_and_test(&cm_id_priv->work_count);
        if (!immediate) {
                list_add_tail(&work->list, &cm_id_priv->work_list);
                /*
                 * This routine always consumes incoming reference. Once queued
                 * to the work_list then a reference is held by the thread
                 * currently running cm_process_work() and this reference is not
                 * needed.
                 */
                cm_deref_id(cm_id_priv);
        }
        spin_unlock_irq(&cm_id_priv->lock);

        if (immediate)
                cm_process_work(cm_id_priv, 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_remove_remote(struct cm_id_private *cm_id_priv)
{
        struct cm_timewait_info *timewait_info = cm_id_priv->timewait_info;

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

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

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

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

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

}

static void cm_enter_timewait(struct cm_id_private *cm_id_priv)
{
        int wait_time;
        unsigned long flags;
        struct cm_device *cm_dev;

        lockdep_assert_held(&cm_id_priv->lock);

        cm_dev = ib_get_client_data(cm_id_priv->id.device, &cm_client);
        if (!cm_dev)
                return;

        spin_lock_irqsave(&cm.lock, flags);
        cm_remove_remote(cm_id_priv);
        list_add_tail(&cm_id_priv->timewait_info->list, &cm.timewait_list);
        spin_unlock_irqrestore(&cm.lock, flags);

        /*
         * The cm_id could be destroyed by the user before we exit timewait.
         * To protect against this, we search for the cm_id after exiting
         * timewait before notifying the user that we've exited timewait.
         */
        cm_id_priv->id.state = IB_CM_TIMEWAIT;
        wait_time = cm_convert_to_ms(cm_id_priv->av.timeout);

        /* Check if the device started its remove_one */
        spin_lock_irqsave(&cm.lock, flags);
        if (!cm_dev->going_down)
                queue_delayed_work(cm.wq, &cm_id_priv->timewait_info->work.work,
                                   msecs_to_jiffies(wait_time));
        spin_unlock_irqrestore(&cm.lock, flags);

        /*
         * The timewait_info is converted into a work and gets freed during
         * cm_free_work() in cm_timewait_handler().
         */
        BUILD_BUG_ON(offsetof(struct cm_timewait_info, work) != 0);
        cm_id_priv->timewait_info = NULL;
}

static void cm_reset_to_idle(struct cm_id_private *cm_id_priv)
{
        unsigned long flags;

        lockdep_assert_held(&cm_id_priv->lock);

        cm_id_priv->id.state = IB_CM_IDLE;
        if (cm_id_priv->timewait_info) {
                spin_lock_irqsave(&cm.lock, flags);
                cm_remove_remote(cm_id_priv);
                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);
        spin_lock_irq(&cm_id_priv->lock);
retest:
        switch (cm_id->state) {
        case IB_CM_LISTEN:
                spin_lock(&cm.lock);
                if (--cm_id_priv->listen_sharecount > 0) {
                        /* The id is still shared. */
                        WARN_ON(refcount_read(&cm_id_priv->refcount) == 1);
                        spin_unlock(&cm.lock);
                        spin_unlock_irq(&cm_id_priv->lock);
                        cm_deref_id(cm_id_priv);
                        return;
                }
                cm_id->state = IB_CM_IDLE;
                rb_erase(&cm_id_priv->service_node, &cm.listen_service_table);
                RB_CLEAR_NODE(&cm_id_priv->service_node);
                spin_unlock(&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);
                break;
        case IB_CM_SIDR_REQ_RCVD:
                cm_send_sidr_rep_locked(cm_id_priv,
                                        &(struct ib_cm_sidr_rep_param){
                                                .status = IB_SIDR_REJECT });
                /* cm_send_sidr_rep_locked will not move to IDLE if it fails */
                cm_id->state = IB_CM_IDLE;
                break;
        case IB_CM_REQ_SENT:
        case IB_CM_MRA_REQ_RCVD:
                ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
                cm_send_rej_locked(cm_id_priv, 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);
                } else {
                        cm_send_rej_locked(cm_id_priv,
                                           IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,
                                           NULL, 0);
                }
                break;
        case IB_CM_REP_SENT:
        case IB_CM_MRA_REP_RCVD:
                ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
                cm_send_rej_locked(cm_id_priv, IB_CM_REJ_CONSUMER_DEFINED, NULL,
                                   0, NULL, 0);
                goto retest;
        case IB_CM_MRA_REQ_SENT:
        case IB_CM_REP_RCVD:
        case IB_CM_MRA_REP_SENT:
                cm_send_rej_locked(cm_id_priv, IB_CM_REJ_CONSUMER_DEFINED, NULL,
                                   0, NULL, 0);
                break;
        case IB_CM_ESTABLISHED:
                if (cm_id_priv->qp_type == IB_QPT_XRC_TGT) {
                        cm_id->state = IB_CM_IDLE;
                        break;
                }
                cm_send_dreq_locked(cm_id_priv, 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);
                goto retest;
        case IB_CM_DREQ_RCVD:
                cm_send_drep_locked(cm_id_priv, NULL, 0);
                WARN_ON(cm_id->state != IB_CM_TIMEWAIT);
                goto retest;
        case IB_CM_TIMEWAIT:
                /*
                 * The cm_acquire_id in cm_timewait_handler will stop working
                 * once we do xa_erase below, so just move to idle here for
                 * consistency.
                 */
                cm_id->state = IB_CM_IDLE;
                break;
        case IB_CM_IDLE:
                break;
        }
        WARN_ON(cm_id->state != IB_CM_IDLE);

        spin_lock(&cm.lock);
        /* Required for cleanup paths related cm_req_handler() */
        if (cm_id_priv->timewait_info) {
                cm_remove_remote(cm_id_priv);
                kfree(cm_id_priv->timewait_info);
                cm_id_priv->timewait_info = NULL;
        }
        if (!list_empty(&cm_id_priv->altr_list) &&
            (!cm_id_priv->altr_send_port_not_ready))
                list_del(&cm_id_priv->altr_list);
        if (!list_empty(&cm_id_priv->prim_list) &&
            (!cm_id_priv->prim_send_port_not_ready))
                list_del(&cm_id_priv->prim_list);
        WARN_ON(cm_id_priv->listen_sharecount);
        WARN_ON(!RB_EMPTY_NODE(&cm_id_priv->service_node));
        if (!RB_EMPTY_NODE(&cm_id_priv->sidr_id_node))
                rb_erase(&cm_id_priv->sidr_id_node, &cm.remote_sidr_table);
        spin_unlock(&cm.lock);
        spin_unlock_irq(&cm_id_priv->lock);

        xa_erase_irq(&cm.local_id_table, cm_local_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);

        rdma_destroy_ah_attr(&cm_id_priv->av.ah_attr);
        rdma_destroy_ah_attr(&cm_id_priv->alt_av.ah_attr);
        kfree(cm_id_priv->private_data);
        kfree_rcu(cm_id_priv, rcu);
}

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

static int cm_init_listen(struct cm_id_private *cm_id_priv, __be64 service_id,
                          __be64 service_mask)
{
        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;

        if (service_id == IB_CM_ASSIGN_SERVICE_ID) {
                cm_id_priv->id.service_id = cpu_to_be64(cm.listen_service_id++);
                cm_id_priv->id.service_mask = ~cpu_to_be64(0);
        } else {
                cm_id_priv->id.service_id = service_id;
                cm_id_priv->id.service_mask = service_mask;
        }
        return 0;
}

/**
 * ib_cm_listen - Initiates listening on the specified service ID for
 *   connection and service ID resolution requests.
 * @cm_id: Connection identifier associated with the listen request.
 * @service_id: Service identifier matched against incoming connection
 *   and service ID resolution requests.  The service ID should be specified
 *   network-byte order.  If set to IB_CM_ASSIGN_SERVICE_ID, the CM will
 *   assign a service ID to the caller.
 * @service_mask: Mask applied to service ID used to listen across a
 *   range of service IDs.  If set to 0, the service ID is matched
 *   exactly.  This parameter is ignored if %service_id is set to
 *   IB_CM_ASSIGN_SERVICE_ID.
 */
int ib_cm_listen(struct ib_cm_id *cm_id, __be64 service_id, __be64 service_mask)
{
        struct cm_id_private *cm_id_priv =
                container_of(cm_id, struct cm_id_private, id);
        unsigned long flags;
        int ret;

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

        ret = cm_init_listen(cm_id_priv, service_id, service_mask);
        if (ret)
                goto out;

        if (!cm_insert_listen(cm_id_priv, NULL)) {
                ret = -EBUSY;
                goto out;
        }

        cm_id_priv->id.state = IB_CM_LISTEN;
        ret = 0;

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

/**
 * Create a new listening ib_cm_id and listen on the given service ID.
 *
 * If there's an existing ID listening on that same device and service ID,
 * return it.
 *
 * @device: Device associated with the cm_id.  All related communication will
 * be associated with the specified device.
 * @cm_handler: Callback invoked to notify the user of CM events.
 * @service_id: Service identifier matched against incoming connection
 *   and service ID resolution requests.  The service ID should be specified
 *   network-byte order.  If set to IB_CM_ASSIGN_SERVICE_ID, the CM will
 *   assign a service ID to the caller.
 *
 * Callers should call ib_destroy_cm_id when done with the listener ID.
 */
struct ib_cm_id *ib_cm_insert_listen(struct ib_device *device,
                                     ib_cm_handler cm_handler,
                                     __be64 service_id)
{
        struct cm_id_private *listen_id_priv;
        struct cm_id_private *cm_id_priv;
        int err = 0;

        /* Create an ID in advance, since the creation may sleep */
        cm_id_priv = cm_alloc_id_priv(device, cm_handler, NULL);
        if (IS_ERR(cm_id_priv))
                return ERR_CAST(cm_id_priv);

        err = cm_init_listen(cm_id_priv, service_id, 0);
        if (err)
                return ERR_PTR(err);

        spin_lock_irq(&cm_id_priv->lock);
        listen_id_priv = cm_insert_listen(cm_id_priv, cm_handler);
        if (listen_id_priv != cm_id_priv) {
                spin_unlock_irq(&cm_id_priv->lock);
                ib_destroy_cm_id(&cm_id_priv->id);
                if (!listen_id_priv)
                        return ERR_PTR(-EINVAL);
                return &listen_id_priv->id;
        }
        cm_id_priv->id.state = IB_CM_LISTEN;
        spin_unlock_irq(&cm_id_priv->lock);

        /*
         * A listen ID does not need to be in the xarray since it does not
         * receive mads, is not placed in the remote_id or remote_qpn rbtree,
         * and does not enter timewait.
         */

        return &cm_id_priv->id;
}
EXPORT_SYMBOL(ib_cm_insert_listen);

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

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

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

static void cm_format_mad_ece_hdr(struct ib_mad_hdr *hdr, __be16 attr_id,
                                  __be64 tid, u32 attr_mod)
{
        cm_format_mad_hdr(hdr, attr_id, tid);
        hdr->attr_mod = cpu_to_be32(attr_mod);
}

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 sa_path_rec *pri_path = param->primary_path;
        struct sa_path_rec *alt_path = param->alternate_path;
        bool pri_ext = false;

        if (pri_path->rec_type == SA_PATH_REC_TYPE_OPA)
                pri_ext = opa_is_extended_lid(pri_path->opa.dlid,
                                              pri_path->opa.slid);

        cm_format_mad_ece_hdr(&req_msg->hdr, CM_REQ_ATTR_ID,
                              cm_form_tid(cm_id_priv), param->ece.attr_mod);

        IBA_SET(CM_REQ_LOCAL_COMM_ID, req_msg,
                be32_to_cpu(cm_id_priv->id.local_id));
        IBA_SET(CM_REQ_SERVICE_ID, req_msg, be64_to_cpu(param->service_id));
        IBA_SET(CM_REQ_LOCAL_CA_GUID, req_msg,
                be64_to_cpu(cm_id_priv->id.device->node_guid));
        IBA_SET(CM_REQ_LOCAL_QPN, req_msg, param->qp_num);
        IBA_SET(CM_REQ_INITIATOR_DEPTH, req_msg, param->initiator_depth);
        IBA_SET(CM_REQ_REMOTE_CM_RESPONSE_TIMEOUT, req_msg,
                param->remote_cm_response_timeout);
        cm_req_set_qp_type(req_msg, param->qp_type);
        IBA_SET(CM_REQ_END_TO_END_FLOW_CONTROL, req_msg, param->flow_control);
        IBA_SET(CM_REQ_STARTING_PSN, req_msg, param->starting_psn);
        IBA_SET(CM_REQ_LOCAL_CM_RESPONSE_TIMEOUT, req_msg,
                param->local_cm_response_timeout);
        IBA_SET(CM_REQ_PARTITION_KEY, req_msg,
                be16_to_cpu(param->primary_path->pkey));
        IBA_SET(CM_REQ_PATH_PACKET_PAYLOAD_MTU, req_msg,
                param->primary_path->mtu);
        IBA_SET(CM_REQ_MAX_CM_RETRIES, req_msg, param->max_cm_retries);

        if (param->qp_type != IB_QPT_XRC_INI) {
                IBA_SET(CM_REQ_RESPONDER_RESOURCES, req_msg,
                        param->responder_resources);
                IBA_SET(CM_REQ_RETRY_COUNT, req_msg, param->retry_count);
                IBA_SET(CM_REQ_RNR_RETRY_COUNT, req_msg,
                        param->rnr_retry_count);
                IBA_SET(CM_REQ_SRQ, req_msg, param->srq);
        }

        *IBA_GET_MEM_PTR(CM_REQ_PRIMARY_LOCAL_PORT_GID, req_msg) =
                pri_path->sgid;
        *IBA_GET_MEM_PTR(CM_REQ_PRIMARY_REMOTE_PORT_GID, req_msg) =
                pri_path->dgid;
        if (pri_ext) {
                IBA_GET_MEM_PTR(CM_REQ_PRIMARY_LOCAL_PORT_GID, req_msg)
                        ->global.interface_id =
                        OPA_MAKE_ID(be32_to_cpu(pri_path->opa.slid));
                IBA_GET_MEM_PTR(CM_REQ_PRIMARY_REMOTE_PORT_GID, req_msg)
                        ->global.interface_id =
                        OPA_MAKE_ID(be32_to_cpu(pri_path->opa.dlid));
        }
        if (pri_path->hop_limit <= 1) {
                IBA_SET(CM_REQ_PRIMARY_LOCAL_PORT_LID, req_msg,
                        be16_to_cpu(pri_ext ? 0 :
                                              htons(ntohl(sa_path_get_slid(
                                                      pri_path)))));
                IBA_SET(CM_REQ_PRIMARY_REMOTE_PORT_LID, req_msg,
                        be16_to_cpu(pri_ext ? 0 :
                                              htons(ntohl(sa_path_get_dlid(
                                                      pri_path)))));
        } else {
                /* Work-around until there's a way to obtain remote LID info */
                IBA_SET(CM_REQ_PRIMARY_LOCAL_PORT_LID, req_msg,
                        be16_to_cpu(IB_LID_PERMISSIVE));
                IBA_SET(CM_REQ_PRIMARY_REMOTE_PORT_LID, req_msg,
                        be16_to_cpu(IB_LID_PERMISSIVE));
        }
        IBA_SET(CM_REQ_PRIMARY_FLOW_LABEL, req_msg,
                be32_to_cpu(pri_path->flow_label));
        IBA_SET(CM_REQ_PRIMARY_PACKET_RATE, req_msg, pri_path->rate);
        IBA_SET(CM_REQ_PRIMARY_TRAFFIC_CLASS, req_msg, pri_path->traffic_class);
        IBA_SET(CM_REQ_PRIMARY_HOP_LIMIT, req_msg, pri_path->hop_limit);
        IBA_SET(CM_REQ_PRIMARY_SL, req_msg, pri_path->sl);
        IBA_SET(CM_REQ_PRIMARY_SUBNET_LOCAL, req_msg,
                (pri_path->hop_limit <= 1));
        IBA_SET(CM_REQ_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) {
                bool alt_ext = false;

                if (alt_path->rec_type == SA_PATH_REC_TYPE_OPA)
                        alt_ext = opa_is_extended_lid(alt_path->opa.dlid,
                                                      alt_path->opa.slid);

                *IBA_GET_MEM_PTR(CM_REQ_ALTERNATE_LOCAL_PORT_GID, req_msg) =
                        alt_path->sgid;
                *IBA_GET_MEM_PTR(CM_REQ_ALTERNATE_REMOTE_PORT_GID, req_msg) =
                        alt_path->dgid;
                if (alt_ext) {
                        IBA_GET_MEM_PTR(CM_REQ_ALTERNATE_LOCAL_PORT_GID,
                                        req_msg)
                                ->global.interface_id =
                                OPA_MAKE_ID(be32_to_cpu(alt_path->opa.slid));
                        IBA_GET_MEM_PTR(CM_REQ_ALTERNATE_REMOTE_PORT_GID,
                                        req_msg)
                                ->global.interface_id =
                                OPA_MAKE_ID(be32_to_cpu(alt_path->opa.dlid));
                }
                if (alt_path->hop_limit <= 1) {
                        IBA_SET(CM_REQ_ALTERNATE_LOCAL_PORT_LID, req_msg,
                                be16_to_cpu(
                                        alt_ext ? 0 :
                                                  htons(ntohl(sa_path_get_slid(
                                                          alt_path)))));
                        IBA_SET(CM_REQ_ALTERNATE_REMOTE_PORT_LID, req_msg,
                                be16_to_cpu(
                                        alt_ext ? 0 :
                                                  htons(ntohl(sa_path_get_dlid(
                                                          alt_path)))));
                } else {
                        IBA_SET(CM_REQ_ALTERNATE_LOCAL_PORT_LID, req_msg,
                                be16_to_cpu(IB_LID_PERMISSIVE));
                        IBA_SET(CM_REQ_ALTERNATE_REMOTE_PORT_LID, req_msg,
                                be16_to_cpu(IB_LID_PERMISSIVE));
                }
                IBA_SET(CM_REQ_ALTERNATE_FLOW_LABEL, req_msg,
                        be32_to_cpu(alt_path->flow_label));
                IBA_SET(CM_REQ_ALTERNATE_PACKET_RATE, req_msg, alt_path->rate);
                IBA_SET(CM_REQ_ALTERNATE_TRAFFIC_CLASS, req_msg,
                        alt_path->traffic_class);
                IBA_SET(CM_REQ_ALTERNATE_HOP_LIMIT, req_msg,
                        alt_path->hop_limit);
                IBA_SET(CM_REQ_ALTERNATE_SL, req_msg, alt_path->sl);
                IBA_SET(CM_REQ_ALTERNATE_SUBNET_LOCAL, req_msg,
                        (alt_path->hop_limit <= 1));
                IBA_SET(CM_REQ_ALTERNATE_LOCAL_ACK_TIMEOUT, req_msg,
                        cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
                                       alt_path->packet_life_time));
        }
        IBA_SET(CM_REQ_VENDOR_ID, req_msg, param->ece.vendor_id);

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

static int cm_validate_req_param(struct ib_cm_req_param *param)
{
        if (!param->primary_path)
                return -EINVAL;

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

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

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

        return 0;
}

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

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

        /* Verify that we're not in timewait. */
        cm_id_priv = container_of(cm_id, struct cm_id_private, id);
        spin_lock_irqsave(&cm_id_priv->lock, flags);
        if (cm_id->state != IB_CM_IDLE || WARN_ON(cm_id_priv->timewait_info)) {
                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,
                                 param->ppath_sgid_attr, &cm_id_priv->av,
                                 cm_id_priv);
        if (ret)
                goto out;
        if (param->alternate_path) {
                ret = cm_init_av_by_path(param->alternate_path, NULL,
                                         &cm_id_priv->alt_av, cm_id_priv);
                if (ret)
                        goto out;
        }
        cm_id->service_id = param->service_id;
        cm_id->service_mask = ~cpu_to_be64(0);
        cm_id_priv->timeout_ms = 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 out;

        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 = cpu_to_be32(IBA_GET(CM_REQ_LOCAL_QPN, req_msg));
        cm_id_priv->rq_psn = cpu_to_be32(IBA_GET(CM_REQ_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);
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);
        IBA_SET(CM_REJ_REMOTE_COMM_ID, rej_msg,
                IBA_GET(CM_REJ_LOCAL_COMM_ID, rcv_msg));
        IBA_SET(CM_REJ_LOCAL_COMM_ID, rej_msg,
                IBA_GET(CM_REJ_REMOTE_COMM_ID, rcv_msg));
        IBA_SET(CM_REJ_MESSAGE_REJECTED, rej_msg, msg_rejected);
        IBA_SET(CM_REJ_REASON, rej_msg, reason);

        if (ari && ari_length) {
                IBA_SET(CM_REJ_REJECTED_INFO_LENGTH, rej_msg, ari_length);
                IBA_SET_MEM(CM_REJ_ARI, rej_msg, ari, ari_length);
        }

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

        return ret;
}

static bool cm_req_has_alt_path(struct cm_req_msg *req_msg)
{
        return ((cpu_to_be16(
                        IBA_GET(CM_REQ_ALTERNATE_LOCAL_PORT_LID, req_msg))) ||
                (ib_is_opa_gid(IBA_GET_MEM_PTR(CM_REQ_ALTERNATE_LOCAL_PORT_GID,
                                               req_msg))));
}

static void cm_path_set_rec_type(struct ib_device *ib_device, u8 port_num,
                                 struct sa_path_rec *path, union ib_gid *gid)
{
        if (ib_is_opa_gid(gid) && rdma_cap_opa_ah(ib_device, port_num))
                path->rec_type = SA_PATH_REC_TYPE_OPA;
        else
                path->rec_type = SA_PATH_REC_TYPE_IB;
}

static void cm_format_path_lid_from_req(struct cm_req_msg *req_msg,
                                        struct sa_path_rec *primary_path,
                                        struct sa_path_rec *alt_path)
{
        u32 lid;

        if (primary_path->rec_type != SA_PATH_REC_TYPE_OPA) {
                sa_path_set_dlid(primary_path,
                                 IBA_GET(CM_REQ_PRIMARY_LOCAL_PORT_LID,
                                         req_msg));
                sa_path_set_slid(primary_path,
                                 IBA_GET(CM_REQ_PRIMARY_REMOTE_PORT_LID,
                                         req_msg));
        } else {
                lid = opa_get_lid_from_gid(IBA_GET_MEM_PTR(
                        CM_REQ_PRIMARY_LOCAL_PORT_GID, req_msg));
                sa_path_set_dlid(primary_path, lid);

                lid = opa_get_lid_from_gid(IBA_GET_MEM_PTR(
                        CM_REQ_PRIMARY_REMOTE_PORT_GID, req_msg));
                sa_path_set_slid(primary_path, lid);
        }

        if (!cm_req_has_alt_path(req_msg))
                return;

        if (alt_path->rec_type != SA_PATH_REC_TYPE_OPA) {
                sa_path_set_dlid(alt_path,
                                 IBA_GET(CM_REQ_ALTERNATE_LOCAL_PORT_LID,
                                         req_msg));
                sa_path_set_slid(alt_path,
                                 IBA_GET(CM_REQ_ALTERNATE_REMOTE_PORT_LID,
                                         req_msg));
        } else {
                lid = opa_get_lid_from_gid(IBA_GET_MEM_PTR(
                        CM_REQ_ALTERNATE_LOCAL_PORT_GID, req_msg));
                sa_path_set_dlid(alt_path, lid);

                lid = opa_get_lid_from_gid(IBA_GET_MEM_PTR(
                        CM_REQ_ALTERNATE_REMOTE_PORT_GID, req_msg));
                sa_path_set_slid(alt_path, lid);
        }
}

static void cm_format_paths_from_req(struct cm_req_msg *req_msg,
                                     struct sa_path_rec *primary_path,
                                     struct sa_path_rec *alt_path)
{
        primary_path->dgid =
                *IBA_GET_MEM_PTR(CM_REQ_PRIMARY_LOCAL_PORT_GID, req_msg);
        primary_path->sgid =
                *IBA_GET_MEM_PTR(CM_REQ_PRIMARY_REMOTE_PORT_GID, req_msg);
        primary_path->flow_label =
                cpu_to_be32(IBA_GET(CM_REQ_PRIMARY_FLOW_LABEL, req_msg));
        primary_path->hop_limit = IBA_GET(CM_REQ_PRIMARY_HOP_LIMIT, req_msg);
        primary_path->traffic_class =
                IBA_GET(CM_REQ_PRIMARY_TRAFFIC_CLASS, req_msg);
        primary_path->reversible = 1;
        primary_path->pkey =
                cpu_to_be16(IBA_GET(CM_REQ_PARTITION_KEY, req_msg));
        primary_path->sl = IBA_GET(CM_REQ_PRIMARY_SL, req_msg);
        primary_path->mtu_selector = IB_SA_EQ;
        primary_path->mtu = IBA_GET(CM_REQ_PATH_PACKET_PAYLOAD_MTU, req_msg);
        primary_path->rate_selector = IB_SA_EQ;
        primary_path->rate = IBA_GET(CM_REQ_PRIMARY_PACKET_RATE, req_msg);
        primary_path->packet_life_time_selector = IB_SA_EQ;
        primary_path->packet_life_time =
                IBA_GET(CM_REQ_PRIMARY_LOCAL_ACK_TIMEOUT, req_msg);
        primary_path->packet_life_time -= (primary_path->packet_life_time > 0);
        primary_path->service_id =
                cpu_to_be64(IBA_GET(CM_REQ_SERVICE_ID, req_msg));
        if (sa_path_is_roce(primary_path))
                primary_path->roce.route_resolved = false;

        if (cm_req_has_alt_path(req_msg)) {
                alt_path->dgid = *IBA_GET_MEM_PTR(
                        CM_REQ_ALTERNATE_LOCAL_PORT_GID, req_msg);
                alt_path->sgid = *IBA_GET_MEM_PTR(
                        CM_REQ_ALTERNATE_REMOTE_PORT_GID, req_msg);
                alt_path->flow_label = cpu_to_be32(
                        IBA_GET(CM_REQ_ALTERNATE_FLOW_LABEL, req_msg));
                alt_path->hop_limit =
                        IBA_GET(CM_REQ_ALTERNATE_HOP_LIMIT, req_msg);
                alt_path->traffic_class =
                        IBA_GET(CM_REQ_ALTERNATE_TRAFFIC_CLASS, req_msg);
                alt_path->reversible = 1;
                alt_path->pkey =
                        cpu_to_be16(IBA_GET(CM_REQ_PARTITION_KEY, req_msg));
                alt_path->sl = IBA_GET(CM_REQ_ALTERNATE_SL, req_msg);
                alt_path->mtu_selector = IB_SA_EQ;
                alt_path->mtu =
                        IBA_GET(CM_REQ_PATH_PACKET_PAYLOAD_MTU, req_msg);
                alt_path->rate_selector = IB_SA_EQ;
                alt_path->rate = IBA_GET(CM_REQ_ALTERNATE_PACKET_RATE, req_msg);
                alt_path->packet_life_time_selector = IB_SA_EQ;
                alt_path->packet_life_time =
                        IBA_GET(CM_REQ_ALTERNATE_LOCAL_ACK_TIMEOUT, req_msg);
                alt_path->packet_life_time -= (alt_path->packet_life_time > 0);
                alt_path->service_id =
                        cpu_to_be64(IBA_GET(CM_REQ_SERVICE_ID, req_msg));

                if (sa_path_is_roce(alt_path))
                        alt_path->roce.route_resolved = false;
        }
        cm_format_path_lid_from_req(req_msg, primary_path, alt_path);
}

static u16 cm_get_bth_pkey(struct cm_work *work)
{
        struct ib_device *ib_dev = work->port->cm_dev->ib_device;
        u8 port_num = work->port->port_num;
        u16 pkey_index = work->mad_recv_wc->wc->pkey_index;
        u16 pkey;
        int ret;

        ret = ib_get_cached_pkey(ib_dev, port_num, pkey_index, &pkey);
        if (ret) {
                dev_warn_ratelimited(&ib_dev->dev, "ib_cm: Couldn't retrieve pkey for incoming request (port %d, pkey index %d). %d\n",
                                     port_num, pkey_index, ret);
                return 0;
        }

        return pkey;
}

/**
 * Convert OPA SGID to IB SGID
 * ULPs (such as IPoIB) do not understand OPA GIDs and will
 * reject them as the local_gid will not match the sgid. Therefore,
 * change the pathrec's SGID to an IB SGID.
 *
 * @work: Work completion
 * @path: Path record
 */
static void cm_opa_to_ib_sgid(struct cm_work *work,
                              struct sa_path_rec *path)
{
        struct ib_device *dev = work->port->cm_dev->ib_device;
        u8 port_num = work->port->port_num;

        if (rdma_cap_opa_ah(dev, port_num) &&
            (ib_is_opa_gid(&path->sgid))) {
                union ib_gid sgid;

                if (rdma_query_gid(dev, port_num, 0, &sgid)) {
                        dev_warn(&dev->dev,
                                 "Error updating sgid in CM request\n");
                        return;
                }

                path->sgid = sgid;
        }
}

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

        req_msg = (struct cm_req_msg *)work->mad_recv_wc->recv_buf.mad;
        param = &work->cm_event.param.req_rcvd;
        param->listen_id = listen_id;
        param->bth_pkey = cm_get_bth_pkey(work);
        param->port = cm_id_priv->av.port->port_num;
        param->primary_path = &work->path[0];
        cm_opa_to_ib_sgid(work, param->primary_path);
        if (cm_req_has_alt_path(req_msg)) {
                param->alternate_path = &work->path[1];
                cm_opa_to_ib_sgid(work, param->alternate_path);
        } else {
                param->alternate_path = NULL;
        }
        param->remote_ca_guid =
                cpu_to_be64(IBA_GET(CM_REQ_LOCAL_CA_GUID, req_msg));
        param->remote_qkey = IBA_GET(CM_REQ_LOCAL_Q_KEY, req_msg);
        param->remote_qpn = IBA_GET(CM_REQ_LOCAL_QPN, req_msg);
        param->qp_type = cm_req_get_qp_type(req_msg);
        param->starting_psn = IBA_GET(CM_REQ_STARTING_PSN, req_msg);
        param->responder_resources = IBA_GET(CM_REQ_INITIATOR_DEPTH, req_msg);
        param->initiator_depth = IBA_GET(CM_REQ_RESPONDER_RESOURCES, req_msg);
        param->local_cm_response_timeout =
                IBA_GET(CM_REQ_REMOTE_CM_RESPONSE_TIMEOUT, req_msg);
        param->flow_control = IBA_GET(CM_REQ_END_TO_END_FLOW_CONTROL, req_msg);
        param->remote_cm_response_timeout =
                IBA_GET(CM_REQ_LOCAL_CM_RESPONSE_TIMEOUT, req_msg);
        param->retry_count = IBA_GET(CM_REQ_RETRY_COUNT, req_msg);
        param->rnr_retry_count = IBA_GET(CM_REQ_RNR_RETRY_COUNT, req_msg);
        param->srq = IBA_GET(CM_REQ_SRQ, req_msg);
        param->ppath_sgid_attr = cm_id_priv->av.ah_attr.grh.sgid_attr;
        param->ece.vendor_id = IBA_GET(CM_REQ_VENDOR_ID, req_msg);
        param->ece.attr_mod = be32_to_cpu(req_msg->hdr.attr_mod);

        work->cm_event.private_data =
                IBA_GET_MEM_PTR(CM_REQ_PRIVATE_DATA, req_msg);
}

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);
                if (!work)
                        return;

                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);
        IBA_SET(CM_MRA_MESSAGE_MRAED, mra_msg, msg_mraed);
        IBA_SET(CM_MRA_LOCAL_COMM_ID, mra_msg,
                be32_to_cpu(cm_id_priv->id.local_id));
        IBA_SET(CM_MRA_REMOTE_COMM_ID, mra_msg,
                be32_to_cpu(cm_id_priv->id.remote_id));
        IBA_SET(CM_MRA_SERVICE_TIMEOUT, mra_msg, service_timeout);

        if (private_data && private_data_len)
                IBA_SET_MEM(CM_MRA_PRIVATE_DATA, mra_msg, 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, enum ib_cm_state state)
{
        lockdep_assert_held(&cm_id_priv->lock);

        cm_format_mad_hdr(&rej_msg->hdr, CM_REJ_ATTR_ID, cm_id_priv->tid);
        IBA_SET(CM_REJ_REMOTE_COMM_ID, rej_msg,
                be32_to_cpu(cm_id_priv->id.remote_id));

        switch (state) {
        case IB_CM_REQ_RCVD:
                IBA_SET(CM_REJ_LOCAL_COMM_ID, rej_msg, be32_to_cpu(0));
                IBA_SET(CM_REJ_MESSAGE_REJECTED, rej_msg, CM_MSG_RESPONSE_REQ);
                break;
        case IB_CM_MRA_REQ_SENT:
                IBA_SET(CM_REJ_LOCAL_COMM_ID, rej_msg,
                        be32_to_cpu(cm_id_priv->id.local_id));
                IBA_SET(CM_REJ_MESSAGE_REJECTED, rej_msg, CM_MSG_RESPONSE_REQ);
                break;
        case IB_CM_REP_RCVD:
        case IB_CM_MRA_REP_SENT:
                IBA_SET(CM_REJ_LOCAL_COMM_ID, rej_msg,
                        be32_to_cpu(cm_id_priv->id.local_id));
                IBA_SET(CM_REJ_MESSAGE_REJECTED, rej_msg, CM_MSG_RESPONSE_REP);
                break;
        default:
                IBA_SET(CM_REJ_LOCAL_COMM_ID, rej_msg,
                        be32_to_cpu(cm_id_priv->id.local_id));
                IBA_SET(CM_REJ_MESSAGE_REJECTED, rej_msg,
                        CM_MSG_RESPONSE_OTHER);
                break;
        }

        IBA_SET(CM_REJ_REASON, rej_msg, reason);
        if (ari && ari_length) {
                IBA_SET(CM_REJ_REJECTED_INFO_LENGTH, rej_msg, ari_length);
                IBA_SET_MEM(CM_REJ_ARI, rej_msg, ari, ari_length);
        }

        if (private_data && private_data_len)
                IBA_SET_MEM(CM_REJ_PRIVATE_DATA, rej_msg, 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. */
        spin_lock_irq(&cm_id_priv->lock);
        if (cm_id_priv->id.state == IB_CM_REQ_RCVD) {
                spin_unlock_irq(&cm_id_priv->lock);
                return;
        }
        spin_unlock_irq(&cm_id_priv->lock);

        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,
                              IB_CM_TIMEWAIT);
                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_acquire_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_remove_remote(cm_id_priv);
                cur_cm_id_priv = cm_acquire_id(timewait_info->work.local_id,

                                           timewait_info->work.remote_id);

                spin_unlock_irq(&cm.lock);
                cm_issue_rej(work->port, work->mad_recv_wc,
                             IB_CM_REJ_STALE_CONN, CM_MSG_RESPONSE_REQ,
                             NULL, 0);
                if (cur_cm_id_priv) {
                        ib_send_cm_dreq(&cur_cm_id_priv->id, NULL, 0);
                        cm_deref_id(cur_cm_id_priv);
                }
                return NULL;
        }

        /* Find matching listen request. */
        listen_cm_id_priv = cm_find_listen(
                cm_id_priv->id.device,
                cpu_to_be64(IBA_GET(CM_REQ_SERVICE_ID, req_msg)));
        if (!listen_cm_id_priv) {
                cm_remove_remote(cm_id_priv);
                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);
                return NULL;
        }
        spin_unlock_irq(&cm.lock);
        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 (!IBA_GET(CM_REQ_PRIMARY_SUBNET_LOCAL, req_msg)) {
                if (cpu_to_be16(IBA_GET(CM_REQ_PRIMARY_LOCAL_PORT_LID,
                                        req_msg)) == IB_LID_PERMISSIVE) {
                        IBA_SET(CM_REQ_PRIMARY_LOCAL_PORT_LID, req_msg,
                                be16_to_cpu(ib_lid_be16(wc->slid)));
                        IBA_SET(CM_REQ_PRIMARY_SL, req_msg, wc->sl);
                }

                if (cpu_to_be16(IBA_GET(CM_REQ_PRIMARY_REMOTE_PORT_LID,
                                        req_msg)) == IB_LID_PERMISSIVE)
                        IBA_SET(CM_REQ_PRIMARY_REMOTE_PORT_LID, req_msg,
                                wc->dlid_path_bits);
        }

        if (!IBA_GET(CM_REQ_ALTERNATE_SUBNET_LOCAL, req_msg)) {
                if (cpu_to_be16(IBA_GET(CM_REQ_ALTERNATE_LOCAL_PORT_LID,
                                        req_msg)) == IB_LID_PERMISSIVE) {
                        IBA_SET(CM_REQ_ALTERNATE_LOCAL_PORT_LID, req_msg,
                                be16_to_cpu(ib_lid_be16(wc->slid)));
                        IBA_SET(CM_REQ_ALTERNATE_SL, req_msg, wc->sl);
                }

                if (cpu_to_be16(IBA_GET(CM_REQ_ALTERNATE_REMOTE_PORT_LID,
                                        req_msg)) == IB_LID_PERMISSIVE)
                        IBA_SET(CM_REQ_ALTERNATE_REMOTE_PORT_LID, req_msg,
                                wc->dlid_path_bits);
        }
}

static int cm_req_handler(struct cm_work *work)
{
        struct cm_id_private *cm_id_priv, *listen_cm_id_priv;
        struct cm_req_msg *req_msg;
        const struct ib_global_route *grh;
        const struct ib_gid_attr *gid_attr;
        int ret;

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

        cm_id_priv =
                cm_alloc_id_priv(work->port->cm_dev->ib_device, NULL, NULL);
        if (IS_ERR(cm_id_priv))
                return PTR_ERR(cm_id_priv);

        cm_id_priv->id.remote_id =
                cpu_to_be32(IBA_GET(CM_REQ_LOCAL_COMM_ID, req_msg));
        cm_id_priv->id.service_id =
                cpu_to_be64(IBA_GET(CM_REQ_SERVICE_ID, req_msg));
        cm_id_priv->id.service_mask = ~cpu_to_be64(0);
        cm_id_priv->tid = req_msg->hdr.tid;
        cm_id_priv->timeout_ms = cm_convert_to_ms(
                IBA_GET(CM_REQ_LOCAL_CM_RESPONSE_TIMEOUT, req_msg));
        cm_id_priv->max_cm_retries = IBA_GET(CM_REQ_MAX_CM_RETRIES, req_msg);
        cm_id_priv->remote_qpn =
                cpu_to_be32(IBA_GET(CM_REQ_LOCAL_QPN, req_msg));
        cm_id_priv->initiator_depth =
                IBA_GET(CM_REQ_RESPONDER_RESOURCES, req_msg);
        cm_id_priv->responder_resources =
                IBA_GET(CM_REQ_INITIATOR_DEPTH, req_msg);
        cm_id_priv->path_mtu = IBA_GET(CM_REQ_PATH_PACKET_PAYLOAD_MTU, req_msg);
        cm_id_priv->pkey = cpu_to_be16(IBA_GET(CM_REQ_PARTITION_KEY, req_msg));
        cm_id_priv->sq_psn = cpu_to_be32(IBA_GET(CM_REQ_STARTING_PSN, req_msg));
        cm_id_priv->retry_count = IBA_GET(CM_REQ_RETRY_COUNT, req_msg);
        cm_id_priv->rnr_retry_count = IBA_GET(CM_REQ_RNR_RETRY_COUNT, req_msg);
        cm_id_priv->qp_type = cm_req_get_qp_type(req_msg);

        ret = cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
                                      work->mad_recv_wc->recv_buf.grh,
                                      &cm_id_priv->av);
        if (ret)
                goto destroy;
        cm_id_priv->timewait_info = cm_create_timewait_info(cm_id_priv->
                                                            id.local_id);
        if (IS_ERR(cm_id_priv->timewait_info)) {
                ret = PTR_ERR(cm_id_priv->timewait_info);
                goto destroy;
        }
        cm_id_priv->timewait_info->work.remote_id = cm_id_priv->id.remote_id;
        cm_id_priv->timewait_info->remote_ca_guid =
                cpu_to_be64(IBA_GET(CM_REQ_LOCAL_CA_GUID, req_msg));
        cm_id_priv->timewait_info->remote_qpn = cm_id_priv->remote_qpn;

        /*
         * Note that the ID pointer is not in the xarray at this point,
         * so this set is only visible to the local thread.
         */
        cm_id_priv->id.state = IB_CM_REQ_RCVD;

        listen_cm_id_priv = cm_match_req(work, cm_id_priv);
        if (!listen_cm_id_priv) {
                pr_debug("%s: local_id %d, no listen_cm_id_priv\n", __func__,
                         be32_to_cpu(cm_id_priv->id.local_id));
                cm_id_priv->id.state = IB_CM_IDLE;
                ret = -EINVAL;
                goto destroy;
        }

        cm_process_routed_req(req_msg, work->mad_recv_wc->wc);

        memset(&work->path[0], 0, sizeof(work->path[0]));
        if (cm_req_has_alt_path(req_msg))
                memset(&work->path[1], 0, sizeof(work->path[1]));
        grh = rdma_ah_read_grh(&cm_id_priv->av.ah_attr);
        gid_attr = grh->sgid_attr;

        if (gid_attr &&
            rdma_protocol_roce(work->port->cm_dev->ib_device,
                               work->port->port_num)) {
                work->path[0].rec_type =
                        sa_conv_gid_to_pathrec_type(gid_attr->gid_type);
        } else {
                cm_path_set_rec_type(
                        work->port->cm_dev->ib_device, work->port->port_num,
                        &work->path[0],
                        IBA_GET_MEM_PTR(CM_REQ_PRIMARY_LOCAL_PORT_GID,
                                        req_msg));
        }
        if (cm_req_has_alt_path(req_msg))
                work->path[1].rec_type = work->path[0].rec_type;
        cm_format_paths_from_req(req_msg, &work->path[0],
                                 &work->path[1]);
        if (cm_id_priv->av.ah_attr.type == RDMA_AH_ATTR_TYPE_ROCE)
                sa_path_set_dmac(&work->path[0],
                                 cm_id_priv->av.ah_attr.roce.dmac);
        work->path[0].hop_limit = grh->hop_limit;
        ret = cm_init_av_by_path(&work->path[0], gid_attr, &cm_id_priv->av,
                                 cm_id_priv);
        if (ret) {
                int err;

                err = rdma_query_gid(work->port->cm_dev->ib_device,
                                     work->port->port_num, 0,
                                     &work->path[0].sgid);
                if (err)
                        ib_send_cm_rej(&cm_id_priv->id, IB_CM_REJ_INVALID_GID,
                                       NULL, 0, NULL, 0);
                else
                        ib_send_cm_rej(&cm_id_priv->id, IB_CM_REJ_INVALID_GID,
                                       &work->path[0].sgid,
                                       sizeof(work->path[0].sgid),
                                       NULL, 0);
                goto rejected;
        }
        if (cm_req_has_alt_path(req_msg)) {
                ret = cm_init_av_by_path(&work->path[1], NULL,
                                         &cm_id_priv->alt_av, cm_id_priv);
                if (ret) {
                        ib_send_cm_rej(&cm_id_priv->id,
                                       IB_CM_REJ_INVALID_ALT_GID,
                                       &work->path[0].sgid,
                                       sizeof(work->path[0].sgid), NULL, 0);
                        goto rejected;
                }
        }

        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_format_req_event(work, cm_id_priv, &listen_cm_id_priv->id);

        /* Now MAD handlers can see the new ID */
        spin_lock_irq(&cm_id_priv->lock);
        cm_finalize_id(cm_id_priv);

        /* Refcount belongs to the event, pairs with cm_process_work() */
        refcount_inc(&cm_id_priv->refcount);
        cm_queue_work_unlock(cm_id_priv, work);
        /*
         * Since this ID was just created and was not made visible to other MAD
         * handlers until the cm_finalize_id() above we know that the
         * cm_process_work() will deliver the event and the listen_cm_id
         * embedded in the event can be derefed here.
         */
        cm_deref_id(listen_cm_id_priv);
        return 0;

rejected:
        cm_deref_id(listen_cm_id_priv);
destroy:
        ib_destroy_cm_id(&cm_id_priv->id);
        return ret;
}

static void cm_format_rep(struct cm_rep_msg *rep_msg,
                          struct cm_id_private *cm_id_priv,
                          struct ib_cm_rep_param *param)
{
        cm_format_mad_ece_hdr(&rep_msg->hdr, CM_REP_ATTR_ID, cm_id_priv->tid,
                              param->ece.attr_mod);
        IBA_SET(CM_REP_LOCAL_COMM_ID, rep_msg,
                be32_to_cpu(cm_id_priv->id.local_id));
        IBA_SET(CM_REP_REMOTE_COMM_ID, rep_msg,
                be32_to_cpu(cm_id_priv->id.remote_id));
        IBA_SET(CM_REP_STARTING_PSN, rep_msg, param->starting_psn);
        IBA_SET(CM_REP_RESPONDER_RESOURCES, rep_msg,
                param->responder_resources);
        IBA_SET(CM_REP_TARGET_ACK_DELAY, rep_msg,
                cm_id_priv->av.port->cm_dev->ack_delay);
        IBA_SET(CM_REP_FAILOVER_ACCEPTED, rep_msg, param->failover_accepted);
        IBA_SET(CM_REP_RNR_RETRY_COUNT, rep_msg, param->rnr_retry_count);
        IBA_SET(CM_REP_LOCAL_CA_GUID, rep_msg,
                be64_to_cpu(cm_id_priv->id.device->node_guid));

        if (cm_id_priv->qp_type != IB_QPT_XRC_TGT) {
                IBA_SET(CM_REP_INITIATOR_DEPTH, rep_msg,
                        param->initiator_depth);
                IBA_SET(CM_REP_END_TO_END_FLOW_CONTROL, rep_msg,
                        param->flow_control);
                IBA_SET(CM_REP_SRQ, rep_msg, param->srq);
                IBA_SET(CM_REP_LOCAL_QPN, rep_msg, param->qp_num);
        } else {
                IBA_SET(CM_REP_SRQ, rep_msg, 1);
                IBA_SET(CM_REP_LOCAL_EE_CONTEXT_NUMBER, rep_msg, param->qp_num);
        }

        IBA_SET(CM_REP_VENDOR_ID_L, rep_msg, param->ece.vendor_id);
        IBA_SET(CM_REP_VENDOR_ID_M, rep_msg, param->ece.vendor_id >> 8);
        IBA_SET(CM_REP_VENDOR_ID_H, rep_msg, param->ece.vendor_id >> 16);

        if (param->private_data && param->private_data_len)
                IBA_SET_MEM(CM_REP_PRIVATE_DATA, rep_msg, 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) {
                pr_debug("%s: local_comm_id %d, cm_id->state: %d\n", __func__,
                         be32_to_cpu(cm_id_priv->id.local_id), cm_id->state);
                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 = cpu_to_be32(IBA_GET(CM_REP_STARTING_PSN, rep_msg));
        WARN_ONCE(param->qp_num & 0xFF000000,
                  "IBTA declares QPN to be 24 bits, but it is 0x%X\n",
                  param->qp_num);
        cm_id_priv->local_qpn = cpu_to_be32(param->qp_num & 0xFFFFFF);

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

static void cm_format_rtu(struct cm_rtu_msg *rtu_msg,
                          struct cm_id_private *cm_id_priv,
                          const void *private_data,
                          u8 private_data_len)
{
        cm_format_mad_hdr(&rtu_msg->hdr, CM_RTU_ATTR_ID, cm_id_priv->tid);
        IBA_SET(CM_RTU_LOCAL_COMM_ID, rtu_msg,
                be32_to_cpu(cm_id_priv->id.local_id));
        IBA_SET(CM_RTU_REMOTE_COMM_ID, rtu_msg,
                be32_to_cpu(cm_id_priv->id.remote_id));

        if (private_data && private_data_len)
                IBA_SET_MEM(CM_RTU_PRIVATE_DATA, rtu_msg, 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) {
                pr_debug("%s: local_id %d, cm_id->state %d\n", __func__,
                         be32_to_cpu(cm_id->local_id), cm_id->state);
                ret = -EINVAL;
                goto error;
        }

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

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

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

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

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

static void cm_format_rep_event(struct cm_work *work, enum ib_qp_type qp_type)
{
        struct cm_rep_msg *rep_msg;
        struct ib_cm_rep_event_param *param;

        rep_msg = (struct cm_rep_msg *)work->mad_recv_wc->recv_buf.mad;
        param = &work->cm_event.param.rep_rcvd;
        param->remote_ca_guid =
                cpu_to_be64(IBA_GET(CM_REP_LOCAL_CA_GUID, rep_msg));
        param->remote_qkey = IBA_GET(CM_REP_LOCAL_Q_KEY, rep_msg);
        param->remote_qpn = be32_to_cpu(cm_rep_get_qpn(rep_msg, qp_type));
        param->starting_psn = IBA_GET(CM_REP_STARTING_PSN, rep_msg);
        param->responder_resources = IBA_GET(CM_REP_INITIATOR_DEPTH, rep_msg);
        param->initiator_depth = IBA_GET(CM_REP_RESPONDER_RESOURCES, rep_msg);
        param->target_ack_delay = IBA_GET(CM_REP_TARGET_ACK_DELAY, rep_msg);
        param->failover_accepted = IBA_GET(CM_REP_FAILOVER_ACCEPTED, rep_msg);
        param->flow_control = IBA_GET(CM_REP_END_TO_END_FLOW_CONTROL, rep_msg);
        param->rnr_retry_count = IBA_GET(CM_REP_RNR_RETRY_COUNT, rep_msg);
        param->srq = IBA_GET(CM_REP_SRQ, rep_msg);
        param->ece.vendor_id = IBA_GET(CM_REP_VENDOR_ID_H, rep_msg) << 16;
        param->ece.vendor_id |= IBA_GET(CM_REP_VENDOR_ID_M, rep_msg) << 8;
        param->ece.vendor_id |= IBA_GET(CM_REP_VENDOR_ID_L, rep_msg);
        param->ece.attr_mod = be32_to_cpu(rep_msg->hdr.attr_mod);

        work->cm_event.private_data =
                IBA_GET_MEM_PTR(CM_REP_PRIVATE_DATA, rep_msg);
}

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(
                cpu_to_be32(IBA_GET(CM_REP_REMOTE_COMM_ID, rep_msg)),
                cpu_to_be32(IBA_GET(CM_REP_LOCAL_COMM_ID, rep_msg)));
        if (!cm_id_priv)
                return;

        atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                        counter[CM_REP_COUNTER]);
        ret = cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg);
        if (ret)
                goto deref;

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

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

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

static int cm_rep_handler(struct cm_work *work)
{
        struct cm_id_private *cm_id_priv;
        struct cm_rep_msg *rep_msg;
        int ret;
        struct cm_id_private *cur_cm_id_priv;
        struct cm_timewait_info *timewait_info;

        rep_msg = (struct cm_rep_msg *)work->mad_recv_wc->recv_buf.mad;
        cm_id_priv = cm_acquire_id(
                cpu_to_be32(IBA_GET(CM_REP_REMOTE_COMM_ID, rep_msg)), 0);
        if (!cm_id_priv) {
                cm_dup_rep_handler(work);
                pr_debug("%s: remote_comm_id %d, no cm_id_priv\n", __func__,
                         IBA_GET(CM_REP_REMOTE_COMM_ID, rep_msg));
                return -EINVAL;
        }

        cm_format_rep_event(work, cm_id_priv->qp_type);

        spin_lock_irq(&cm_id_priv->lock);
        switch (cm_id_priv->id.state) {
        case IB_CM_REQ_SENT:
        case IB_CM_MRA_REQ_RCVD:
                break;
        default:
                ret = -EINVAL;
                pr_debug(
                        "%s: cm_id_priv->id.state: %d, local_comm_id %d, remote_comm_id %d\n",
                        __func__, cm_id_priv->id.state,
                        IBA_GET(CM_REP_LOCAL_COMM_ID, rep_msg),
                        IBA_GET(CM_REP_REMOTE_COMM_ID, rep_msg));
                spin_unlock_irq(&cm_id_priv->lock);
                goto error;
        }

        cm_id_priv->timewait_info->work.remote_id =
                cpu_to_be32(IBA_GET(CM_REP_LOCAL_COMM_ID, rep_msg));
        cm_id_priv->timewait_info->remote_ca_guid =
                cpu_to_be64(IBA_GET(CM_REP_LOCAL_CA_GUID, rep_msg));
        cm_id_priv->timewait_info->remote_qpn = cm_rep_get_qpn(rep_msg, cm_id_priv->qp_type);

        spin_lock(&cm.lock);
        /* Check for duplicate REP. */
        if (cm_insert_remote_id(cm_id_priv->timewait_info)) {
                spin_unlock(&cm.lock);
                spin_unlock_irq(&cm_id_priv->lock);
                ret = -EINVAL;
                pr_debug("%s: Failed to insert remote id %d\n", __func__,
                         IBA_GET(CM_REP_REMOTE_COMM_ID, rep_msg));
                goto error;
        }
        /* Check for a stale connection. */
        timewait_info = cm_insert_remote_qpn(cm_id_priv->timewait_info);
        if (timewait_info) {
                cm_remove_remote(cm_id_priv);
                cur_cm_id_priv = cm_acquire_id(timewait_info->work.local_id,
                                           timewait_info->work.remote_id);

                spin_unlock(&cm.lock);
                spin_unlock_irq(&cm_id_priv->lock);
                cm_issue_rej(work->port, work->mad_recv_wc,
                             IB_CM_REJ_STALE_CONN, CM_MSG_RESPONSE_REP,
                             NULL, 0);
                ret = -EINVAL;
                pr_debug(
                        "%s: Stale connection. local_comm_id %d, remote_comm_id %d\n",
                        __func__, IBA_GET(CM_REP_LOCAL_COMM_ID, rep_msg),
                        IBA_GET(CM_REP_REMOTE_COMM_ID, rep_msg));

                if (cur_cm_id_priv) {
                        ib_send_cm_dreq(&cur_cm_id_priv->id, NULL, 0);
                        cm_deref_id(cur_cm_id_priv);
                }

                goto error;
        }
        spin_unlock(&cm.lock);

        cm_id_priv->id.state = IB_CM_REP_RCVD;
        cm_id_priv->id.remote_id =
                cpu_to_be32(IBA_GET(CM_REP_LOCAL_COMM_ID, rep_msg));
        cm_id_priv->remote_qpn = cm_rep_get_qpn(rep_msg, cm_id_priv->qp_type);
        cm_id_priv->initiator_depth =
                IBA_GET(CM_REP_RESPONDER_RESOURCES, rep_msg);
        cm_id_priv->responder_resources =
                IBA_GET(CM_REP_INITIATOR_DEPTH, rep_msg);
        cm_id_priv->sq_psn = cpu_to_be32(IBA_GET(CM_REP_STARTING_PSN, rep_msg));
        cm_id_priv->rnr_retry_count = IBA_GET(CM_REP_RNR_RETRY_COUNT, rep_msg);
        cm_id_priv->target_ack_delay =
                IBA_GET(CM_REP_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);

        ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
        cm_queue_work_unlock(cm_id_priv, work);
        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;

        /* 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);
        cm_queue_work_unlock(cm_id_priv, work);
        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;

        rtu_msg = (struct cm_rtu_msg *)work->mad_recv_wc->recv_buf.mad;
        cm_id_priv = cm_acquire_id(
                cpu_to_be32(IBA_GET(CM_RTU_REMOTE_COMM_ID, rtu_msg)),
                cpu_to_be32(IBA_GET(CM_RTU_LOCAL_COMM_ID, rtu_msg)));
        if (!cm_id_priv)
                return -EINVAL;

        work->cm_event.private_data =
                IBA_GET_MEM_PTR(CM_RTU_PRIVATE_DATA, rtu_msg);

        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);
        cm_queue_work_unlock(cm_id_priv, work);
        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));
        IBA_SET(CM_DREQ_LOCAL_COMM_ID, dreq_msg,
                be32_to_cpu(cm_id_priv->id.local_id));
        IBA_SET(CM_DREQ_REMOTE_COMM_ID, dreq_msg,
                be32_to_cpu(cm_id_priv->id.remote_id));
        IBA_SET(CM_DREQ_REMOTE_QPN_EECN, dreq_msg,
                be32_to_cpu(cm_id_priv->remote_qpn));

        if (private_data && private_data_len)
                IBA_SET_MEM(CM_DREQ_PRIVATE_DATA, dreq_msg, private_data,
                            private_data_len);
}

static int cm_send_dreq_locked(struct cm_id_private *cm_id_priv,
                               const void *private_data, u8 private_data_len)
{
        struct ib_mad_send_buf *msg;
        int ret;

        lockdep_assert_held(&cm_id_priv->lock);

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

        if (cm_id_priv->id.state != IB_CM_ESTABLISHED) {
                pr_debug("%s: local_id %d, cm_id->state: %d\n", __func__,
                         be32_to_cpu(cm_id_priv->id.local_id),
                         cm_id_priv->id.state);
                return -EINVAL;
        }

        if (cm_id_priv->id.lap_state == IB_CM_LAP_SENT ||
            cm_id_priv->id.lap_state == IB_CM_MRA_LAP_RCVD)
                ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);

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

        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);
                cm_free_msg(msg);
                return ret;
        }

        cm_id_priv->id.state = IB_CM_DREQ_SENT;
        cm_id_priv->msg = msg;
        return 0;
}

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 =
                container_of(cm_id, struct cm_id_private, id);
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&cm_id_priv->lock, flags);
        ret = cm_send_dreq_locked(cm_id_priv, private_data, private_data_len);
        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);
        IBA_SET(CM_DREP_LOCAL_COMM_ID, drep_msg,
                be32_to_cpu(cm_id_priv->id.local_id));
        IBA_SET(CM_DREP_REMOTE_COMM_ID, drep_msg,
                be32_to_cpu(cm_id_priv->id.remote_id));

        if (private_data && private_data_len)
                IBA_SET_MEM(CM_DREP_PRIVATE_DATA, drep_msg, private_data,
                            private_data_len);
}

static int cm_send_drep_locked(struct cm_id_private *cm_id_priv,
                               void *private_data, u8 private_data_len)
{
        struct ib_mad_send_buf *msg;
        int ret;

        lockdep_assert_held(&cm_id_priv->lock);

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

        if (cm_id_priv->id.state != IB_CM_DREQ_RCVD) {
                pr_debug(
                        "%s: local_id %d, cm_idcm_id->state(%d) != IB_CM_DREQ_RCVD\n",
                        __func__, be32_to_cpu(cm_id_priv->id.local_id),
                        cm_id_priv->id.state);
                kfree(private_data);
                return -EINVAL;
        }

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

        ret = cm_alloc_msg(cm_id_priv, &msg);
        if (ret)
                return ret;

        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) {
                cm_free_msg(msg);
                return ret;
        }
        return 0;
}

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 =
                container_of(cm_id, struct cm_id_private, id);
        unsigned long flags;
        void *data;
        int ret;

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

        spin_lock_irqsave(&cm_id_priv->lock, flags);
        ret = cm_send_drep_locked(cm_id_priv, data, private_data_len);
        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);
        IBA_SET(CM_DREP_REMOTE_COMM_ID, drep_msg,
                IBA_GET(CM_DREQ_LOCAL_COMM_ID, dreq_msg));
        IBA_SET(CM_DREP_LOCAL_COMM_ID, drep_msg,
                IBA_GET(CM_DREQ_REMOTE_COMM_ID, dreq_msg));

        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;

        dreq_msg = (struct cm_dreq_msg *)work->mad_recv_wc->recv_buf.mad;
        cm_id_priv = cm_acquire_id(
                cpu_to_be32(IBA_GET(CM_DREQ_REMOTE_COMM_ID, dreq_msg)),
                cpu_to_be32(IBA_GET(CM_DREQ_LOCAL_COMM_ID, dreq_msg)));
        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);
                pr_debug(
                        "%s: no cm_id_priv, local_comm_id %d, remote_comm_id %d\n",
                        __func__, IBA_GET(CM_DREQ_LOCAL_COMM_ID, dreq_msg),
                        IBA_GET(CM_DREQ_REMOTE_COMM_ID, dreq_msg));
                return -EINVAL;
        }

        work->cm_event.private_data =
                IBA_GET_MEM_PTR(CM_DREQ_PRIVATE_DATA, dreq_msg);

        spin_lock_irq(&cm_id_priv->lock);
        if (cm_id_priv->local_qpn !=
            cpu_to_be32(IBA_GET(CM_DREQ_REMOTE_QPN_EECN, dreq_msg)))
                goto unlock;

        switch (cm_id_priv->id.state) {
        case IB_CM_REP_SENT:
        case IB_CM_DREQ_SENT:
                ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
                break;
        case IB_CM_ESTABLISHED:
                if (cm_id_priv->id.lap_state == IB_CM_LAP_SENT ||
                    cm_id_priv->id.lap_state == IB_CM_MRA_LAP_RCVD)
                        ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
                break;
        case IB_CM_MRA_REP_RCVD:
                break;
        case IB_CM_TIMEWAIT:
                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                counter[CM_DREQ_COUNTER]);
                msg = cm_alloc_response_msg_no_ah(work->port, work->mad_recv_wc);
                if (IS_ERR(msg))
                        goto unlock;

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

                if (cm_create_response_msg_ah(work->port, work->mad_recv_wc, msg) ||
                    ib_post_send_mad(msg, NULL))
                        cm_free_msg(msg);
                goto deref;
        case IB_CM_DREQ_RCVD:
                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
                                counter[CM_DREQ_COUNTER]);
                goto unlock;
        default:
                pr_debug("%s: local_id %d, cm_id_priv->id.state: %d\n",
                         __func__, be32_to_cpu(cm_id_priv->id.local_id),
                         cm_id_priv->id.state);
                goto unlock;
        }
        cm_id_priv->id.state = IB_CM_DREQ_RCVD;
        cm_id_priv->tid = dreq_msg->hdr.tid;
        cm_queue_work_unlock(cm_id_priv, work);
        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;

        drep_msg = (struct cm_drep_msg *)work->mad_recv_wc->recv_buf.mad;
        cm_id_priv = cm_acquire_id(
                cpu_to_be32(IBA_GET(CM_DREP_REMOTE_COMM_ID, drep_msg)),
                cpu_to_be32(IBA_GET(CM_DREP_LOCAL_COMM_ID, drep_msg)));
        if (!cm_id_priv)
                return -EINVAL;

        work->cm_event.private_data =
                IBA_GET_MEM_PTR(CM_DREP_PRIVATE_DATA, drep_msg);

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

static int cm_send_rej_locked(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)
{
        enum ib_cm_state state = cm_id_priv->id.state;
        struct ib_mad_send_buf *msg;
        int ret;

        lockdep_assert_held(&cm_id_priv->lock);

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

        switch (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:
                cm_reset_to_idle(cm_id_priv);
                ret = cm_alloc_msg(cm_id_priv, &msg);
                if (ret)
                        return ret;
                cm_format_rej((struct cm_rej_msg *)msg->mad, cm_id_priv, reason,
                              ari, ari_length, private_data, private_data_len,
                              state);
                break;
        case IB_CM_REP_SENT:
        case IB_CM_MRA_REP_RCVD:
                cm_enter_timewait(cm_id_priv);
                ret = cm_alloc_msg(cm_id_priv, &msg);
                if (ret)
                        return ret;
                cm_format_rej((struct cm_rej_msg *)msg->mad, cm_id_priv, reason,
                              ari, ari_length, private_data, private_data_len,
                              state);
                break;
        default:
                pr_debug("%s: local_id %d, cm_id->state: %d\n", __func__,
                         be32_to_cpu(cm_id_priv->id.local_id),
                         cm_id_priv->id.state);
                return -EINVAL;
        }

        ret = ib_post_send_mad(msg, NULL);
        if (ret) {
                cm_free_msg(msg);
                return ret;
        }

        return 0;
}

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 =
                container_of(cm_id, struct cm_id_private, id);
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&cm_id_priv->lock, flags);
        ret = cm_send_rej_locked(cm_id_priv, reason, ari, ari_length,
                                 private_data, private_data_len);
        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 = IBA_GET_MEM_PTR(CM_REJ_ARI, rej_msg);
        param->ari_length = IBA_GET(CM_REJ_REJECTED_INFO_LENGTH, rej_msg);
        param->reason = IBA_GET(CM_REJ_REASON, rej_msg);
        work->cm_event.private_data =
                IBA_GET_MEM_PTR(CM_REJ_PRIVATE_DATA, rej_msg);
}

static struct cm_id_private * cm_acquire_rejected_id(struct cm_rej_msg *rej_msg)
{
        struct cm_id_private *cm_id_priv;
        __be32 remote_id;

        remote_id = cpu_to_be32(IBA_GET(CM_REJ_LOCAL_COMM_ID, rej_msg));