mad.c

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/*
 * Copyright (c) 2004-2007 Voltaire, Inc. All rights reserved.
 * Copyright (c) 2005 Intel Corporation.  All rights reserved.
 * Copyright (c) 2005 Mellanox Technologies Ltd.  All rights reserved.
 * Copyright (c) 2009 HNR Consulting. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <rdma/ib_cache.h>

#include "mad_priv.h"
#include "mad_rmpp.h"
#include "smi.h"
#include "agent.h"

MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("kernel IB MAD API");
MODULE_AUTHOR("Hal Rosenstock");
MODULE_AUTHOR("Sean Hefty");

static int mad_sendq_size = IB_MAD_QP_SEND_SIZE;
static int mad_recvq_size = IB_MAD_QP_RECV_SIZE;

module_param_named(send_queue_size, mad_sendq_size, int, 0444);
MODULE_PARM_DESC(send_queue_size, "Size of send queue in number of work requests");
module_param_named(recv_queue_size, mad_recvq_size, int, 0444);
MODULE_PARM_DESC(recv_queue_size, "Size of receive queue in number of work requests");

static struct kmem_cache *ib_mad_cache;

static struct list_head ib_mad_port_list;
static u32 ib_mad_client_id = 0;

/* Port list lock */
static DEFINE_SPINLOCK(ib_mad_port_list_lock);

/* Forward declarations */
static int method_in_use(struct ib_mad_mgmt_method_table **method,
             struct ib_mad_reg_req *mad_reg_req);
static void remove_mad_reg_req(struct ib_mad_agent_private *priv);
static struct ib_mad_agent_private *find_mad_agent(
                    struct ib_mad_port_private *port_priv,
                    struct ib_mad *mad);
static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info,
                    struct ib_mad_private *mad);
static void cancel_mads(struct ib_mad_agent_private *mad_agent_priv);
static void timeout_sends(struct work_struct *work);
static void local_completions(struct work_struct *work);
static int add_nonoui_reg_req(struct ib_mad_reg_req *mad_reg_req,
                  struct ib_mad_agent_private *agent_priv,
                  u8 mgmt_class);
static int add_oui_reg_req(struct ib_mad_reg_req *mad_reg_req,
               struct ib_mad_agent_private *agent_priv);

/*
 * Returns a ib_mad_port_private structure or NULL for a device/port
 * Assumes ib_mad_port_list_lock is being held
 */
static inline struct ib_mad_port_private *
__ib_get_mad_port(struct ib_device *device, int port_num)
{
    struct ib_mad_port_private *entry;

    list_for_each_entry(entry, &ib_mad_port_list, port_list) {
        if (entry->device == device && entry->port_num == port_num)
            return entry;
    }
    return NULL;
}

/*
 * Wrapper function to return a ib_mad_port_private structure or NULL
 * for a device/port
 */
static inline struct ib_mad_port_private *
ib_get_mad_port(struct ib_device *device, int port_num)
{
    struct ib_mad_port_private *entry;
    unsigned long flags;

    spin_lock_irqsave(&ib_mad_port_list_lock, flags);
    entry = __ib_get_mad_port(device, port_num);
    spin_unlock_irqrestore(&ib_mad_port_list_lock, flags);

    return entry;
}

static inline u8 convert_mgmt_class(u8 mgmt_class)
{
    /* Alias IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE to 0 */
    return mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE ?
        0 : mgmt_class;
}

static int get_spl_qp_index(enum ib_qp_type qp_type)
{
    switch (qp_type)
    {
    case IB_QPT_SMI:
        return 0;
    case IB_QPT_GSI:
        return 1;
    default:
        return -1;
    }
}

static int vendor_class_index(u8 mgmt_class)
{
    return mgmt_class - IB_MGMT_CLASS_VENDOR_RANGE2_START;
}

static int is_vendor_class(u8 mgmt_class)
{
    if ((mgmt_class < IB_MGMT_CLASS_VENDOR_RANGE2_START) ||
        (mgmt_class > IB_MGMT_CLASS_VENDOR_RANGE2_END))
        return 0;
    return 1;
}

static int is_vendor_oui(char *oui)
{
    if (oui[0] || oui[1] || oui[2])
        return 1;
    return 0;
}

static int is_vendor_method_in_use(
        struct ib_mad_mgmt_vendor_class *vendor_class,
        struct ib_mad_reg_req *mad_reg_req)
{
    struct ib_mad_mgmt_method_table *method;
    int i;

    for (i = 0; i < MAX_MGMT_OUI; i++) {
        if (!memcmp(vendor_class->oui[i], mad_reg_req->oui, 3)) {
            method = vendor_class->method_table[i];
            if (method) {
                if (method_in_use(&method, mad_reg_req))
                    return 1;
                else
                    break;
            }
        }
    }
    return 0;
}

int ib_response_mad(struct ib_mad *mad)
{
    return ((mad->mad_hdr.method & IB_MGMT_METHOD_RESP) ||
        (mad->mad_hdr.method == IB_MGMT_METHOD_TRAP_REPRESS) ||
        ((mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_BM) &&
         (mad->mad_hdr.attr_mod & IB_BM_ATTR_MOD_RESP)));
}
EXPORT_SYMBOL(ib_response_mad);

/*
 * ib_register_mad_agent - Register to send/receive MADs
 */
struct ib_mad_agent *ib_register_mad_agent(struct ib_device *device,
                       u8 port_num,
                       enum ib_qp_type qp_type,
                       struct ib_mad_reg_req *mad_reg_req,
                       u8 rmpp_version,
                       ib_mad_send_handler send_handler,
                       ib_mad_recv_handler recv_handler,
                       void *context)
{
    struct ib_mad_port_private *port_priv;
    struct ib_mad_agent *ret = ERR_PTR(-EINVAL);
    struct ib_mad_agent_private *mad_agent_priv;
    struct ib_mad_reg_req *reg_req = NULL;
    struct ib_mad_mgmt_class_table *class;
    struct ib_mad_mgmt_vendor_class_table *vendor;
    struct ib_mad_mgmt_vendor_class *vendor_class;
    struct ib_mad_mgmt_method_table *method;
    int ret2, qpn;
    unsigned long flags;
    u8 mgmt_class, vclass;

    /* Validate parameters */
    qpn = get_spl_qp_index(qp_type);
    if (qpn == -1)
        goto error1;

    if (rmpp_version && rmpp_version != IB_MGMT_RMPP_VERSION)
        goto error1;

    /* Validate MAD registration request if supplied */
    if (mad_reg_req) {
        if (mad_reg_req->mgmt_class_version >= MAX_MGMT_VERSION)
            goto error1;
        if (!recv_handler)
            goto error1;
        if (mad_reg_req->mgmt_class >= MAX_MGMT_CLASS) {
            /*
             * IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE is the only
             * one in this range currently allowed
             */
            if (mad_reg_req->mgmt_class !=
                IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
                goto error1;
        } else if (mad_reg_req->mgmt_class == 0) {
            /*
             * Class 0 is reserved in IBA and is used for
             * aliasing of IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE
             */
            goto error1;
        } else if (is_vendor_class(mad_reg_req->mgmt_class)) {
            /*
             * If class is in "new" vendor range,
             * ensure supplied OUI is not zero
             */
            if (!is_vendor_oui(mad_reg_req->oui))
                goto error1;
        }
        /* Make sure class supplied is consistent with RMPP */
        if (!ib_is_mad_class_rmpp(mad_reg_req->mgmt_class)) {
            if (rmpp_version)
                goto error1;
        }
        /* Make sure class supplied is consistent with QP type */
        if (qp_type == IB_QPT_SMI) {
            if ((mad_reg_req->mgmt_class !=
                    IB_MGMT_CLASS_SUBN_LID_ROUTED) &&
                (mad_reg_req->mgmt_class !=
                    IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE))
                goto error1;
        } else {
            if ((mad_reg_req->mgmt_class ==
                    IB_MGMT_CLASS_SUBN_LID_ROUTED) ||
                (mad_reg_req->mgmt_class ==
                    IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE))
                goto error1;
        }
    } else {
        /* No registration request supplied */
        if (!send_handler)
            goto error1;
    }

    /* Validate device and port */
    port_priv = ib_get_mad_port(device, port_num);
    if (!port_priv) {
        ret = ERR_PTR(-ENODEV);
        goto error1;
    }

    /* Verify the QP requested is supported.  For example, Ethernet devices
     * will not have QP0 */
    if (!port_priv->qp_info[qpn].qp) {
        ret = ERR_PTR(-EPROTONOSUPPORT);
        goto error1;
    }

    /* Allocate structures */
    mad_agent_priv = kzalloc(sizeof *mad_agent_priv, GFP_KERNEL);
    if (!mad_agent_priv) {
        ret = ERR_PTR(-ENOMEM);
        goto error1;
    }

    mad_agent_priv->agent.mr = ib_get_dma_mr(port_priv->qp_info[qpn].qp->pd,
                         IB_ACCESS_LOCAL_WRITE);
    if (IS_ERR(mad_agent_priv->agent.mr)) {
        ret = ERR_PTR(-ENOMEM);
        goto error2;
    }

    if (mad_reg_req) {
        reg_req = kmemdup(mad_reg_req, sizeof *reg_req, GFP_KERNEL);
        if (!reg_req) {
            ret = ERR_PTR(-ENOMEM);
            goto error3;
        }
    }

    /* Now, fill in the various structures */
    mad_agent_priv->qp_info = &port_priv->qp_info[qpn];
    mad_agent_priv->reg_req = reg_req;
    mad_agent_priv->agent.rmpp_version = rmpp_version;
    mad_agent_priv->agent.device = device;
    mad_agent_priv->agent.recv_handler = recv_handler;
    mad_agent_priv->agent.send_handler = send_handler;
    mad_agent_priv->agent.context = context;
    mad_agent_priv->agent.qp = port_priv->qp_info[qpn].qp;
    mad_agent_priv->agent.port_num = port_num;
    spin_lock_init(&mad_agent_priv->lock);
    INIT_LIST_HEAD(&mad_agent_priv->send_list);
    INIT_LIST_HEAD(&mad_agent_priv->wait_list);
    INIT_LIST_HEAD(&mad_agent_priv->done_list);
    INIT_LIST_HEAD(&mad_agent_priv->rmpp_list);
    INIT_DELAYED_WORK(&mad_agent_priv->timed_work, timeout_sends);
    INIT_LIST_HEAD(&mad_agent_priv->local_list);
    INIT_WORK(&mad_agent_priv->local_work, local_completions);
    atomic_set(&mad_agent_priv->refcount, 1);
    init_completion(&mad_agent_priv->comp);

    spin_lock_irqsave(&port_priv->reg_lock, flags);
    mad_agent_priv->agent.hi_tid = ++ib_mad_client_id;

    /*
     * Make sure MAD registration (if supplied)
     * is non overlapping with any existing ones
     */
    if (mad_reg_req) {
        mgmt_class = convert_mgmt_class(mad_reg_req->mgmt_class);
        if (!is_vendor_class(mgmt_class)) {
            class = port_priv->version[mad_reg_req->
                           mgmt_class_version].class;
            if (class) {
                method = class->method_table[mgmt_class];
                if (method) {
                    if (method_in_use(&method,
                               mad_reg_req))
                        goto error4;
                }
            }
            ret2 = add_nonoui_reg_req(mad_reg_req, mad_agent_priv,
                          mgmt_class);
        } else {
            /* "New" vendor class range */
            vendor = port_priv->version[mad_reg_req->
                            mgmt_class_version].vendor;
            if (vendor) {
                vclass = vendor_class_index(mgmt_class);
                vendor_class = vendor->vendor_class[vclass];
                if (vendor_class) {
                    if (is_vendor_method_in_use(
                            vendor_class,
                            mad_reg_req))
                        goto error4;
                }
            }
            ret2 = add_oui_reg_req(mad_reg_req, mad_agent_priv);
        }
        if (ret2) {
            ret = ERR_PTR(ret2);
            goto error4;
        }
    }

    /* Add mad agent into port's agent list */
    list_add_tail(&mad_agent_priv->agent_list, &port_priv->agent_list);
    spin_unlock_irqrestore(&port_priv->reg_lock, flags);

    return &mad_agent_priv->agent;

error4:
    spin_unlock_irqrestore(&port_priv->reg_lock, flags);
    kfree(reg_req);
error3:
    ib_dereg_mr(mad_agent_priv->agent.mr);
error2:
    kfree(mad_agent_priv);
error1:
    return ret;
}
EXPORT_SYMBOL(ib_register_mad_agent);

static inline int is_snooping_sends(int mad_snoop_flags)
{
    return (mad_snoop_flags &
        (/*IB_MAD_SNOOP_POSTED_SENDS |
         IB_MAD_SNOOP_RMPP_SENDS |*/
         IB_MAD_SNOOP_SEND_COMPLETIONS /*|
         IB_MAD_SNOOP_RMPP_SEND_COMPLETIONS*/));
}

static inline int is_snooping_recvs(int mad_snoop_flags)
{
    return (mad_snoop_flags &
        (IB_MAD_SNOOP_RECVS /*|
         IB_MAD_SNOOP_RMPP_RECVS*/));
}

static int register_snoop_agent(struct ib_mad_qp_info *qp_info,
                struct ib_mad_snoop_private *mad_snoop_priv)
{
    struct ib_mad_snoop_private **new_snoop_table;
    unsigned long flags;
    int i;

    spin_lock_irqsave(&qp_info->snoop_lock, flags);
    /* Check for empty slot in array. */
    for (i = 0; i < qp_info->snoop_table_size; i++)
        if (!qp_info->snoop_table[i])
            break;

    if (i == qp_info->snoop_table_size) {
        /* Grow table. */
        new_snoop_table = krealloc(qp_info->snoop_table,
                       sizeof mad_snoop_priv *
                       (qp_info->snoop_table_size + 1),
                       GFP_ATOMIC);
        if (!new_snoop_table) {
            i = -ENOMEM;
            goto out;
        }

        qp_info->snoop_table = new_snoop_table;
        qp_info->snoop_table_size++;
    }
    qp_info->snoop_table[i] = mad_snoop_priv;
    atomic_inc(&qp_info->snoop_count);
out:
    spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
    return i;
}

struct ib_mad_agent *ib_register_mad_snoop(struct ib_device *device,
                       u8 port_num,
                       enum ib_qp_type qp_type,
                       int mad_snoop_flags,
                       ib_mad_snoop_handler snoop_handler,
                       ib_mad_recv_handler recv_handler,
                       void *context)
{
    struct ib_mad_port_private *port_priv;
    struct ib_mad_agent *ret;
    struct ib_mad_snoop_private *mad_snoop_priv;
    int qpn;

    /* Validate parameters */
    if ((is_snooping_sends(mad_snoop_flags) && !snoop_handler) ||
        (is_snooping_recvs(mad_snoop_flags) && !recv_handler)) {
        ret = ERR_PTR(-EINVAL);
        goto error1;
    }
    qpn = get_spl_qp_index(qp_type);
    if (qpn == -1) {
        ret = ERR_PTR(-EINVAL);
        goto error1;
    }
    port_priv = ib_get_mad_port(device, port_num);
    if (!port_priv) {
        ret = ERR_PTR(-ENODEV);
        goto error1;
    }
    /* Allocate structures */
    mad_snoop_priv = kzalloc(sizeof *mad_snoop_priv, GFP_KERNEL);
    if (!mad_snoop_priv) {
        ret = ERR_PTR(-ENOMEM);
        goto error1;
    }

    /* Now, fill in the various structures */
    mad_snoop_priv->qp_info = &port_priv->qp_info[qpn];
    mad_snoop_priv->agent.device = device;
    mad_snoop_priv->agent.recv_handler = recv_handler;
    mad_snoop_priv->agent.snoop_handler = snoop_handler;
    mad_snoop_priv->agent.context = context;
    mad_snoop_priv->agent.qp = port_priv->qp_info[qpn].qp;
    mad_snoop_priv->agent.port_num = port_num;
    mad_snoop_priv->mad_snoop_flags = mad_snoop_flags;
    init_completion(&mad_snoop_priv->comp);
    mad_snoop_priv->snoop_index = register_snoop_agent(
                        &port_priv->qp_info[qpn],
                        mad_snoop_priv);
    if (mad_snoop_priv->snoop_index < 0) {
        ret = ERR_PTR(mad_snoop_priv->snoop_index);
        goto error2;
    }

    atomic_set(&mad_snoop_priv->refcount, 1);
    return &mad_snoop_priv->agent;

error2:
    kfree(mad_snoop_priv);
error1:
    return ret;
}
EXPORT_SYMBOL(ib_register_mad_snoop);

static inline void deref_mad_agent(struct ib_mad_agent_private *mad_agent_priv)
{
    if (atomic_dec_and_test(&mad_agent_priv->refcount))
        complete(&mad_agent_priv->comp);
}

static inline void deref_snoop_agent(struct ib_mad_snoop_private *mad_snoop_priv)
{
    if (atomic_dec_and_test(&mad_snoop_priv->refcount))
        complete(&mad_snoop_priv->comp);
}

static void unregister_mad_agent(struct ib_mad_agent_private *mad_agent_priv)
{
    struct ib_mad_port_private *port_priv;
    unsigned long flags;

    /* Note that we could still be handling received MADs */

    /*
     * Canceling all sends results in dropping received response
     * MADs, preventing us from queuing additional work
     */
    cancel_mads(mad_agent_priv);
    port_priv = mad_agent_priv->qp_info->port_priv;
    cancel_delayed_work(&mad_agent_priv->timed_work);

    spin_lock_irqsave(&port_priv->reg_lock, flags);
    remove_mad_reg_req(mad_agent_priv);
    list_del(&mad_agent_priv->agent_list);
    spin_unlock_irqrestore(&port_priv->reg_lock, flags);

    flush_workqueue(port_priv->wq);
    ib_cancel_rmpp_recvs(mad_agent_priv);

    deref_mad_agent(mad_agent_priv);
    wait_for_completion(&mad_agent_priv->comp);

    kfree(mad_agent_priv->reg_req);
    ib_dereg_mr(mad_agent_priv->agent.mr);
    kfree(mad_agent_priv);
}

static void unregister_mad_snoop(struct ib_mad_snoop_private *mad_snoop_priv)
{
    struct ib_mad_qp_info *qp_info;
    unsigned long flags;

    qp_info = mad_snoop_priv->qp_info;
    spin_lock_irqsave(&qp_info->snoop_lock, flags);
    qp_info->snoop_table[mad_snoop_priv->snoop_index] = NULL;
    atomic_dec(&qp_info->snoop_count);
    spin_unlock_irqrestore(&qp_info->snoop_lock, flags);

    deref_snoop_agent(mad_snoop_priv);
    wait_for_completion(&mad_snoop_priv->comp);

    kfree(mad_snoop_priv);
}

/*
 * ib_unregister_mad_agent - Unregisters a client from using MAD services
 */
int ib_unregister_mad_agent(struct ib_mad_agent *mad_agent)
{
    struct ib_mad_agent_private *mad_agent_priv;
    struct ib_mad_snoop_private *mad_snoop_priv;

    /* If the TID is zero, the agent can only snoop. */
    if (mad_agent->hi_tid) {
        mad_agent_priv = container_of(mad_agent,
                          struct ib_mad_agent_private,
                          agent);
        unregister_mad_agent(mad_agent_priv);
    } else {
        mad_snoop_priv = container_of(mad_agent,
                          struct ib_mad_snoop_private,
                          agent);
        unregister_mad_snoop(mad_snoop_priv);
    }
    return 0;
}
EXPORT_SYMBOL(ib_unregister_mad_agent);

static void dequeue_mad(struct ib_mad_list_head *mad_list)
{
    struct ib_mad_queue *mad_queue;
    unsigned long flags;

    BUG_ON(!mad_list->mad_queue);
    mad_queue = mad_list->mad_queue;
    spin_lock_irqsave(&mad_queue->lock, flags);
    list_del(&mad_list->list);
    mad_queue->count--;
    spin_unlock_irqrestore(&mad_queue->lock, flags);
}

static void snoop_send(struct ib_mad_qp_info *qp_info,
               struct ib_mad_send_buf *send_buf,
               struct ib_mad_send_wc *mad_send_wc,
               int mad_snoop_flags)
{
    struct ib_mad_snoop_private *mad_snoop_priv;
    unsigned long flags;
    int i;

    spin_lock_irqsave(&qp_info->snoop_lock, flags);
    for (i = 0; i < qp_info->snoop_table_size; i++) {
        mad_snoop_priv = qp_info->snoop_table[i];
        if (!mad_snoop_priv ||
            !(mad_snoop_priv->mad_snoop_flags & mad_snoop_flags))
            continue;

        atomic_inc(&mad_snoop_priv->refcount);
        spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
        mad_snoop_priv->agent.snoop_handler(&mad_snoop_priv->agent,
                            send_buf, mad_send_wc);
        deref_snoop_agent(mad_snoop_priv);
        spin_lock_irqsave(&qp_info->snoop_lock, flags);
    }
    spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
}

static void snoop_recv(struct ib_mad_qp_info *qp_info,
               struct ib_mad_recv_wc *mad_recv_wc,
               int mad_snoop_flags)
{
    struct ib_mad_snoop_private *mad_snoop_priv;
    unsigned long flags;
    int i;

    spin_lock_irqsave(&qp_info->snoop_lock, flags);
    for (i = 0; i < qp_info->snoop_table_size; i++) {
        mad_snoop_priv = qp_info->snoop_table[i];
        if (!mad_snoop_priv ||
            !(mad_snoop_priv->mad_snoop_flags & mad_snoop_flags))
            continue;

        atomic_inc(&mad_snoop_priv->refcount);
        spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
        mad_snoop_priv->agent.recv_handler(&mad_snoop_priv->agent,
                           mad_recv_wc);
        deref_snoop_agent(mad_snoop_priv);
        spin_lock_irqsave(&qp_info->snoop_lock, flags);
    }
    spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
}

static void build_smp_wc(struct ib_qp *qp,
             u64 wr_id, u16 slid, u16 pkey_index, u8 port_num,
             struct ib_wc *wc)
{
    memset(wc, 0, sizeof *wc);
    wc->wr_id = wr_id;
    wc->status = IB_WC_SUCCESS;
    wc->opcode = IB_WC_RECV;
    wc->pkey_index = pkey_index;
    wc->byte_len = sizeof(struct ib_mad) + sizeof(struct ib_grh);
    wc->src_qp = IB_QP0;
    wc->qp = qp;
    wc->slid = slid;
    wc->sl = 0;
    wc->dlid_path_bits = 0;
    wc->port_num = port_num;
}

/*
 * Return 0 if SMP is to be sent
 * Return 1 if SMP was consumed locally (whether or not solicited)
 * Return < 0 if error
 */
static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
                  struct ib_mad_send_wr_private *mad_send_wr)
{
    int ret = 0;
    struct ib_smp *smp = mad_send_wr->send_buf.mad;
    unsigned long flags;
    struct ib_mad_local_private *local;
    struct ib_mad_private *mad_priv;
    struct ib_mad_port_private *port_priv;
    struct ib_mad_agent_private *recv_mad_agent = NULL;
    struct ib_device *device = mad_agent_priv->agent.device;
    u8 port_num;
    struct ib_wc mad_wc;
    struct ib_send_wr *send_wr = &mad_send_wr->send_wr;

    if (device->node_type == RDMA_NODE_IB_SWITCH &&
        smp->mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
        port_num = send_wr->wr.ud.port_num;
    else
        port_num = mad_agent_priv->agent.port_num;

    /*
     * Directed route handling starts if the initial LID routed part of
     * a request or the ending LID routed part of a response is empty.
     * If we are at the start of the LID routed part, don't update the
     * hop_ptr or hop_cnt.  See section 14.2.2, Vol 1 IB spec.
     */
    if ((ib_get_smp_direction(smp) ? smp->dr_dlid : smp->dr_slid) ==
         IB_LID_PERMISSIVE &&
         smi_handle_dr_smp_send(smp, device->node_type, port_num) ==
         IB_SMI_DISCARD) {
        ret = -EINVAL;
        printk(KERN_ERR PFX "Invalid directed route\n");
        goto out;
    }

    /* Check to post send on QP or process locally */
    if (smi_check_local_smp(smp, device) == IB_SMI_DISCARD &&
        smi_check_local_returning_smp(smp, device) == IB_SMI_DISCARD)
        goto out;

    local = kmalloc(sizeof *local, GFP_ATOMIC);
    if (!local) {
        ret = -ENOMEM;
        printk(KERN_ERR PFX "No memory for ib_mad_local_private\n");
        goto out;
    }
    local->mad_priv = NULL;
    local->recv_mad_agent = NULL;
    mad_priv = kmem_cache_alloc(ib_mad_cache, GFP_ATOMIC);
    if (!mad_priv) {
        ret = -ENOMEM;
        printk(KERN_ERR PFX "No memory for local response MAD\n");
        kfree(local);
        goto out;
    }

    build_smp_wc(mad_agent_priv->agent.qp,
             send_wr->wr_id, be16_to_cpu(smp->dr_slid),
             send_wr->wr.ud.pkey_index,
             send_wr->wr.ud.port_num, &mad_wc);

    /* No GRH for DR SMP */
    ret = device->process_mad(device, 0, port_num, &mad_wc, NULL,
                  (struct ib_mad *)smp,
                  (struct ib_mad *)&mad_priv->mad);
    switch (ret)
    {
    case IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY:
        if (ib_response_mad(&mad_priv->mad.mad) &&
            mad_agent_priv->agent.recv_handler) {
            local->mad_priv = mad_priv;
            local->recv_mad_agent = mad_agent_priv;
            /*
             * Reference MAD agent until receive
             * side of local completion handled
             */
            atomic_inc(&mad_agent_priv->refcount);
        } else
            kmem_cache_free(ib_mad_cache, mad_priv);
        break;
    case IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED:
        kmem_cache_free(ib_mad_cache, mad_priv);
        break;
    case IB_MAD_RESULT_SUCCESS:
        /* Treat like an incoming receive MAD */
        port_priv = ib_get_mad_port(mad_agent_priv->agent.device,
                        mad_agent_priv->agent.port_num);
        if (port_priv) {
            memcpy(&mad_priv->mad.mad, smp, sizeof(struct ib_mad));
            recv_mad_agent = find_mad_agent(port_priv,
                                &mad_priv->mad.mad);
        }
        if (!port_priv || !recv_mad_agent) {
            /*
             * No receiving agent so drop packet and
             * generate send completion.
             */
            kmem_cache_free(ib_mad_cache, mad_priv);
            break;
        }
        local->mad_priv = mad_priv;
        local->recv_mad_agent = recv_mad_agent;
        break;
    default:
        kmem_cache_free(ib_mad_cache, mad_priv);
        kfree(local);
        ret = -EINVAL;
        goto out;
    }

    local->mad_send_wr = mad_send_wr;
    /* Reference MAD agent until send side of local completion handled */
    atomic_inc(&mad_agent_priv->refcount);
    /* Queue local completion to local list */
    spin_lock_irqsave(&mad_agent_priv->lock, flags);
    list_add_tail(&local->completion_list, &mad_agent_priv->local_list);
    spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
    queue_work(mad_agent_priv->qp_info->port_priv->wq,
           &mad_agent_priv->local_work);
    ret = 1;
out:
    return ret;
}

static int get_pad_size(int hdr_len, int data_len)
{
    int seg_size, pad;

    seg_size = sizeof(struct ib_mad) - hdr_len;
    if (data_len && seg_size) {
        pad = seg_size - data_len % seg_size;
        return pad == seg_size ? 0 : pad;
    } else
        return seg_size;
}

static void free_send_rmpp_list(struct ib_mad_send_wr_private *mad_send_wr)
{
    struct ib_rmpp_segment *s, *t;

    list_for_each_entry_safe(s, t, &mad_send_wr->rmpp_list, list) {
        list_del(&s->list);
        kfree(s);
    }
}

static int alloc_send_rmpp_list(struct ib_mad_send_wr_private *send_wr,
                gfp_t gfp_mask)
{
    struct ib_mad_send_buf *send_buf = &send_wr->send_buf;
    struct ib_rmpp_mad *rmpp_mad = send_buf->mad;
    struct ib_rmpp_segment *seg = NULL;
    int left, seg_size, pad;

    send_buf->seg_size = sizeof (struct ib_mad) - send_buf->hdr_len;
    seg_size = send_buf->seg_size;
    pad = send_wr->pad;

    /* Allocate data segments. */
    for (left = send_buf->data_len + pad; left > 0; left -= seg_size) {
        seg = kmalloc(sizeof (*seg) + seg_size, gfp_mask);
        if (!seg) {
            printk(KERN_ERR "alloc_send_rmpp_segs: RMPP mem "
                   "alloc failed for len %zd, gfp %#x\n",
                   sizeof (*seg) + seg_size, gfp_mask);
            free_send_rmpp_list(send_wr);
            return -ENOMEM;
        }
        seg->num = ++send_buf->seg_count;
        list_add_tail(&seg->list, &send_wr->rmpp_list);
    }

    /* Zero any padding */
    if (pad)
        memset(seg->data + seg_size - pad, 0, pad);

    rmpp_mad->rmpp_hdr.rmpp_version = send_wr->mad_agent_priv->
                      agent.rmpp_version;
    rmpp_mad->rmpp_hdr.rmpp_type = IB_MGMT_RMPP_TYPE_DATA;
    ib_set_rmpp_flags(&rmpp_mad->rmpp_hdr, IB_MGMT_RMPP_FLAG_ACTIVE);

    send_wr->cur_seg = container_of(send_wr->rmpp_list.next,
                    struct ib_rmpp_segment, list);
    send_wr->last_ack_seg = send_wr->cur_seg;
    return 0;
}

struct ib_mad_send_buf * ib_create_send_mad(struct ib_mad_agent *mad_agent,
                        u32 remote_qpn, u16 pkey_index,
                        int rmpp_active,
                        int hdr_len, int data_len,
                        gfp_t gfp_mask)
{
    struct ib_mad_agent_private *mad_agent_priv;
    struct ib_mad_send_wr_private *mad_send_wr;
    int pad, message_size, ret, size;
    void *buf;

    mad_agent_priv = container_of(mad_agent, struct ib_mad_agent_private,
                      agent);
    pad = get_pad_size(hdr_len, data_len);
    message_size = hdr_len + data_len + pad;

    if ((!mad_agent->rmpp_version &&
         (rmpp_active || message_size > sizeof(struct ib_mad))) ||
        (!rmpp_active && message_size > sizeof(struct ib_mad)))
        return ERR_PTR(-EINVAL);

    size = rmpp_active ? hdr_len : sizeof(struct ib_mad);
    buf = kzalloc(sizeof *mad_send_wr + size, gfp_mask);
    if (!buf)
        return ERR_PTR(-ENOMEM);

    mad_send_wr = buf + size;
    INIT_LIST_HEAD(&mad_send_wr->rmpp_list);
    mad_send_wr->send_buf.mad = buf;
    mad_send_wr->send_buf.hdr_len = hdr_len;
    mad_send_wr->send_buf.data_len = data_len;
    mad_send_wr->pad = pad;

    mad_send_wr->mad_agent_priv = mad_agent_priv;
    mad_send_wr->sg_list[0].length = hdr_len;
    mad_send_wr->sg_list[0].lkey = mad_agent->mr->lkey;
    mad_send_wr->sg_list[1].length = sizeof(struct ib_mad) - hdr_len;
    mad_send_wr->sg_list[1].lkey = mad_agent->mr->lkey;

    mad_send_wr->send_wr.wr_id = (unsigned long) mad_send_wr;
    mad_send_wr->send_wr.sg_list = mad_send_wr->sg_list;
    mad_send_wr->send_wr.num_sge = 2;
    mad_send_wr->send_wr.opcode = IB_WR_SEND;
    mad_send_wr->send_wr.send_flags = IB_SEND_SIGNALED;
    mad_send_wr->send_wr.wr.ud.remote_qpn = remote_qpn;
    mad_send_wr->send_wr.wr.ud.remote_qkey = IB_QP_SET_QKEY;
    mad_send_wr->send_wr.wr.ud.pkey_index = pkey_index;

    if (rmpp_active) {
        ret = alloc_send_rmpp_list(mad_send_wr, gfp_mask);
        if (ret) {
            kfree(buf);
            return ERR_PTR(ret);
        }
    }

    mad_send_wr->send_buf.mad_agent = mad_agent;
    atomic_inc(&mad_agent_priv->refcount);
    return &mad_send_wr->send_buf;
}
EXPORT_SYMBOL(ib_create_send_mad);

int ib_get_mad_data_offset(u8 mgmt_class)
{
    if (mgmt_class == IB_MGMT_CLASS_SUBN_ADM)
        return IB_MGMT_SA_HDR;
    else if ((mgmt_class == IB_MGMT_CLASS_DEVICE_MGMT) ||
         (mgmt_class == IB_MGMT_CLASS_DEVICE_ADM) ||
         (mgmt_class == IB_MGMT_CLASS_BIS))
        return IB_MGMT_DEVICE_HDR;
    else if ((mgmt_class >= IB_MGMT_CLASS_VENDOR_RANGE2_START) &&
         (mgmt_class <= IB_MGMT_CLASS_VENDOR_RANGE2_END))
        return IB_MGMT_VENDOR_HDR;
    else
        return IB_MGMT_MAD_HDR;
}
EXPORT_SYMBOL(ib_get_mad_data_offset);

int ib_is_mad_class_rmpp(u8 mgmt_class)
{
    if ((mgmt_class == IB_MGMT_CLASS_SUBN_ADM) ||
        (mgmt_class == IB_MGMT_CLASS_DEVICE_MGMT) ||
        (mgmt_class == IB_MGMT_CLASS_DEVICE_ADM) ||
        (mgmt_class == IB_MGMT_CLASS_BIS) ||
        ((mgmt_class >= IB_MGMT_CLASS_VENDOR_RANGE2_START) &&
         (mgmt_class <= IB_MGMT_CLASS_VENDOR_RANGE2_END)))
        return 1;
    return 0;
}
EXPORT_SYMBOL(ib_is_mad_class_rmpp);

void *ib_get_rmpp_segment(struct ib_mad_send_buf *send_buf, int seg_num)
{
    struct ib_mad_send_wr_private *mad_send_wr;
    struct list_head *list;

    mad_send_wr = container_of(send_buf, struct ib_mad_send_wr_private,
                   send_buf);
    list = &mad_send_wr->cur_seg->list;

    if (mad_send_wr->cur_seg->num < seg_num) {
        list_for_each_entry(mad_send_wr->cur_seg, list, list)
            if (mad_send_wr->cur_seg->num == seg_num)
                break;
    } else if (mad_send_wr->cur_seg->num > seg_num) {
        list_for_each_entry_reverse(mad_send_wr->cur_seg, list, list)
            if (mad_send_wr->cur_seg->num == seg_num)
                break;
    }
    return mad_send_wr->cur_seg->data;
}
EXPORT_SYMBOL(ib_get_rmpp_segment);

static inline void *ib_get_payload(struct ib_mad_send_wr_private *mad_send_wr)
{
    if (mad_send_wr->send_buf.seg_count)
        return ib_get_rmpp_segment(&mad_send_wr->send_buf,
                       mad_send_wr->seg_num);
    else
        return mad_send_wr->send_buf.mad +
               mad_send_wr->send_buf.hdr_len;
}

void ib_free_send_mad(struct ib_mad_send_buf *send_buf)
{
    struct ib_mad_agent_private *mad_agent_priv;
    struct ib_mad_send_wr_private *mad_send_wr;

    mad_agent_priv = container_of(send_buf->mad_agent,
                      struct ib_mad_agent_private, agent);
    mad_send_wr = container_of(send_buf, struct ib_mad_send_wr_private,
                   send_buf);

    free_send_rmpp_list(mad_send_wr);
    kfree(send_buf->mad);
    deref_mad_agent(mad_agent_priv);
}
EXPORT_SYMBOL(ib_free_send_mad);

int ib_send_mad(struct ib_mad_send_wr_private *mad_send_wr)
{
    struct ib_mad_qp_info *qp_info;
    struct list_head *list;
    struct ib_send_wr *bad_send_wr;
    struct ib_mad_agent *mad_agent;
    struct ib_sge *sge;
    unsigned long flags;
    int ret;

    /* Set WR ID to find mad_send_wr upon completion */
    qp_info = mad_send_wr->mad_agent_priv->qp_info;
    mad_send_wr->send_wr.wr_id = (unsigned long)&mad_send_wr->mad_list;
    mad_send_wr->mad_list.mad_queue = &qp_info->send_queue;

    mad_agent = mad_send_wr->send_buf.mad_agent;
    sge = mad_send_wr->sg_list;
    sge[0].addr = ib_dma_map_single(mad_agent->device,
                    mad_send_wr->send_buf.mad,
                    sge[0].length,
                    DMA_TO_DEVICE);
    mad_send_wr->header_mapping = sge[0].addr;

    sge[1].addr = ib_dma_map_single(mad_agent->device,
                    ib_get_payload(mad_send_wr),
                    sge[1].length,
                    DMA_TO_DEVICE);
    mad_send_wr->payload_mapping = sge[1].addr;

    spin_lock_irqsave(&qp_info->send_queue.lock, flags);
    if (qp_info->send_queue.count < qp_info->send_queue.max_active) {
        ret = ib_post_send(mad_agent->qp, &mad_send_wr->send_wr,
                   &bad_send_wr);
        list = &qp_info->send_queue.list;
    } else {
        ret = 0;
        list = &qp_info->overflow_list;
    }

    if (!ret) {
        qp_info->send_queue.count++;
        list_add_tail(&mad_send_wr->mad_list.list, list);
    }
    spin_unlock_irqrestore(&qp_info->send_queue.lock, flags);
    if (ret) {
        ib_dma_unmap_single(mad_agent->device,
                    mad_send_wr->header_mapping,
                    sge[0].length, DMA_TO_DEVICE);
        ib_dma_unmap_single(mad_agent->device,
                    mad_send_wr->payload_mapping,
                    sge[1].length, DMA_TO_DEVICE);
    }
    return ret;
}

/*
 * ib_post_send_mad - Posts MAD(s) to the send queue of the QP associated
 *  with the registered client
 */
int ib_post_send_mad(struct ib_mad_send_buf *send_buf,
             struct ib_mad_send_buf **bad_send_buf)
{
    struct ib_mad_agent_private *mad_agent_priv;
    struct ib_mad_send_buf *next_send_buf;
    struct ib_mad_send_wr_private *mad_send_wr;
    unsigned long flags;
    int ret = -EINVAL;

    /* Walk list of send WRs and post each on send list */
    for (; send_buf; send_buf = next_send_buf) {

        mad_send_wr = container_of(send_buf,
                       struct ib_mad_send_wr_private,
                       send_buf);
        mad_agent_priv = mad_send_wr->mad_agent_priv;

        if (!send_buf->mad_agent->send_handler ||
            (send_buf->timeout_ms &&
             !send_buf->mad_agent->recv_handler)) {
            ret = -EINVAL;
            goto error;
        }

        if (!ib_is_mad_class_rmpp(((struct ib_mad_hdr *) send_buf->mad)->mgmt_class)) {
            if (mad_agent_priv->agent.rmpp_version) {
                ret = -EINVAL;
                goto error;
            }
        }

        /*
         * Save pointer to next work request to post in case the
         * current one completes, and the user modifies the work
         * request associated with the completion
         */
        next_send_buf = send_buf->next;
        mad_send_wr->send_wr.wr.ud.ah = send_buf->ah;

        if (((struct ib_mad_hdr *) send_buf->mad)->mgmt_class ==
            IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
            ret = handle_outgoing_dr_smp(mad_agent_priv,
                             mad_send_wr);
            if (ret < 0)        /* error */
                goto error;
            else if (ret == 1)  /* locally consumed */
                continue;
        }

        mad_send_wr->tid = ((struct ib_mad_hdr *) send_buf->mad)->tid;
        /* Timeout will be updated after send completes */
        mad_send_wr->timeout = msecs_to_jiffies(send_buf->timeout_ms);
        mad_send_wr->max_retries = send_buf->retries;
        mad_send_wr->retries_left = send_buf->retries;
        send_buf->retries = 0;
        /* Reference for work request to QP + response */
        mad_send_wr->refcount = 1 + (mad_send_wr->timeout > 0);
        mad_send_wr->status = IB_WC_SUCCESS;

        /* Reference MAD agent until send completes */
        atomic_inc(&mad_agent_priv->refcount);
        spin_lock_irqsave(&mad_agent_priv->lock, flags);
        list_add_tail(&mad_send_wr->agent_list,
                  &mad_agent_priv->send_list);
        spin_unlock_irqrestore(&mad_agent_priv->lock, flags);

        if (mad_agent_priv->agent.rmpp_version) {
            ret = ib_send_rmpp_mad(mad_send_wr);
            if (ret >= 0 && ret != IB_RMPP_RESULT_CONSUMED)
                ret = ib_send_mad(mad_send_wr);
        } else
            ret = ib_send_mad(mad_send_wr);
        if (ret < 0) {
            /* Fail send request */
            spin_lock_irqsave(&mad_agent_priv->lock, flags);
            list_del(&mad_send_wr->agent_list);
            spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
            atomic_dec(&mad_agent_priv->refcount);
            goto error;
        }
    }
    return 0;
error:
    if (bad_send_buf)
        *bad_send_buf = send_buf;
    return ret;
}
EXPORT_SYMBOL(ib_post_send_mad);

/*
 * ib_free_recv_mad - Returns data buffers used to receive
 *  a MAD to the access layer
 */
void ib_free_recv_mad(struct ib_mad_recv_wc *mad_recv_wc)
{
    struct ib_mad_recv_buf *mad_recv_buf, *temp_recv_buf;
    struct ib_mad_private_header *mad_priv_hdr;
    struct ib_mad_private *priv;
    struct list_head free_list;

    INIT_LIST_HEAD(&free_list);
    list_splice_init(&mad_recv_wc->rmpp_list, &free_list);

    list_for_each_entry_safe(mad_recv_buf, temp_recv_buf,
                    &free_list, list) {
        mad_recv_wc = container_of(mad_recv_buf, struct ib_mad_recv_wc,
                       recv_buf);
        mad_priv_hdr = container_of(mad_recv_wc,
                        struct ib_mad_private_header,
                        recv_wc);
        priv = container_of(mad_priv_hdr, struct ib_mad_private,
                    header);
        kmem_cache_free(ib_mad_cache, priv);
    }
}
EXPORT_SYMBOL(ib_free_recv_mad);

struct ib_mad_agent *ib_redirect_mad_qp(struct ib_qp *qp,
                    u8 rmpp_version,
                    ib_mad_send_handler send_handler,
                    ib_mad_recv_handler recv_handler,
                    void *context)
{
    return ERR_PTR(-EINVAL);    /* XXX: for now */
}
EXPORT_SYMBOL(ib_redirect_mad_qp);

int ib_process_mad_wc(struct ib_mad_agent *mad_agent,
              struct ib_wc *wc)
{
    printk(KERN_ERR PFX "ib_process_mad_wc() not implemented yet\n");
    return 0;
}
EXPORT_SYMBOL(ib_process_mad_wc);

static int method_in_use(struct ib_mad_mgmt_method_table **method,
             struct ib_mad_reg_req *mad_reg_req)
{
    int i;

    for_each_set_bit(i, mad_reg_req->method_mask, IB_MGMT_MAX_METHODS) {
        if ((*method)->agent[i]) {
            printk(KERN_ERR PFX "Method %d already in use\n", i);
            return -EINVAL;
        }
    }
    return 0;
}

static int allocate_method_table(struct ib_mad_mgmt_method_table **method)
{
    /* Allocate management method table */
    *method = kzalloc(sizeof **method, GFP_ATOMIC);
    if (!*method) {
        printk(KERN_ERR PFX "No memory for "
               "ib_mad_mgmt_method_table\n");
        return -ENOMEM;
    }

    return 0;
}

/*
 * Check to see if there are any methods still in use
 */
static int check_method_table(struct ib_mad_mgmt_method_table *method)
{
    int i;

    for (i = 0; i < IB_MGMT_MAX_METHODS; i++)
        if (method->agent[i])
            return 1;
    return 0;
}

/*
 * Check to see if there are any method tables for this class still in use
 */
static int check_class_table(struct ib_mad_mgmt_class_table *class)
{
    int i;

    for (i = 0; i < MAX_MGMT_CLASS; i++)
        if (class->method_table[i])
            return 1;
    return 0;
}

static int check_vendor_class(struct ib_mad_mgmt_vendor_class *vendor_class)
{
    int i;

    for (i = 0; i < MAX_MGMT_OUI; i++)
        if (vendor_class->method_table[i])
            return 1;
    return 0;
}

static int find_vendor_oui(struct ib_mad_mgmt_vendor_class *vendor_class,
               char *oui)
{
    int i;

    for (i = 0; i < MAX_MGMT_OUI; i++)
        /* Is there matching OUI for this vendor class ? */
        if (!memcmp(vendor_class->oui[i], oui, 3))
            return i;

    return -1;
}

static int check_vendor_table(struct ib_mad_mgmt_vendor_class_table *vendor)
{
    int i;

    for (i = 0; i < MAX_MGMT_VENDOR_RANGE2; i++)
        if (vendor->vendor_class[i])
            return 1;

    return 0;
}

static void remove_methods_mad_agent(struct ib_mad_mgmt_method_table *method,
                     struct ib_mad_agent_private *agent)
{
    int i;

    /* Remove any methods for this mad agent */
    for (i = 0; i < IB_MGMT_MAX_METHODS; i++) {
        if (method->agent[i] == agent) {
            method->agent[i] = NULL;
        }
    }
}

static int add_nonoui_reg_req(struct ib_mad_reg_req *mad_reg_req,
                  struct ib_mad_agent_private *agent_priv,
                  u8 mgmt_class)
{
    struct ib_mad_port_private *port_priv;
    struct ib_mad_mgmt_class_table **class;
    struct ib_mad_mgmt_method_table **method;
    int i, ret;

    port_priv = agent_priv->qp_info->port_priv;
    class = &port_priv->version[mad_reg_req->mgmt_class_version].class;
    if (!*class) {
        /* Allocate management class table for "new" class version */
        *class = kzalloc(sizeof **class, GFP_ATOMIC);
        if (!*class) {
            printk(KERN_ERR PFX "No memory for "
                   "ib_mad_mgmt_class_table\n");
            ret = -ENOMEM;
            goto error1;
        }

        /* Allocate method table for this management class */
        method = &(*class)->method_table[mgmt_class];
        if ((ret = allocate_method_table(method)))
            goto error2;
    } else {
        method = &(*class)->method_table[mgmt_class];
        if (!*method) {
            /* Allocate method table for this management class */
            if ((ret = allocate_method_table(method)))
                goto error1;
        }
    }

    /* Now, make sure methods are not already in use */
    if (method_in_use(method, mad_reg_req))
        goto error3;

    /* Finally, add in methods being registered */
    for_each_set_bit(i, mad_reg_req->method_mask, IB_MGMT_MAX_METHODS)
        (*method)->agent[i] = agent_priv;

    return 0;

error3:
    /* Remove any methods for this mad agent */
    remove_methods_mad_agent(*method, agent_priv);
    /* Now, check to see if there are any methods in use */
    if (!check_method_table(*method)) {
        /* If not, release management method table */
        kfree(*method);
        *method = NULL;
    }
    ret = -EINVAL;
    goto error1;
error2:
    kfree(*class);
    *class = NULL;
error1:
    return ret;
}

static int add_oui_reg_req(struct ib_mad_reg_req *mad_reg_req,
               struct ib_mad_agent_private *agent_priv)
{
    struct ib_mad_port_private *port_priv;
    struct ib_mad_mgmt_vendor_class_table **vendor_table;
    struct ib_mad_mgmt_vendor_class_table *vendor = NULL;
    struct ib_mad_mgmt_vendor_class *vendor_class = NULL;
    struct ib_mad_mgmt_method_table **method;
    int i, ret = -ENOMEM;
    u8 vclass;

    /* "New" vendor (with OUI) class */
    vclass = vendor_class_index(mad_reg_req->mgmt_class);
    port_priv = agent_priv->qp_info->port_priv;
    vendor_table = &port_priv->version[
                mad_reg_req->mgmt_class_version].vendor;
    if (!*vendor_table) {
        /* Allocate mgmt vendor class table for "new" class version */
        vendor = kzalloc(sizeof *vendor, GFP_ATOMIC);
        if (!vendor) {
            printk(KERN_ERR PFX "No memory for "
                   "ib_mad_mgmt_vendor_class_table\n");
            goto error1;
        }

        *vendor_table = vendor;
    }
    if (!(*vendor_table)->vendor_class[vclass]) {
        /* Allocate table for this management vendor class */
        vendor_class = kzalloc(sizeof *vendor_class, GFP_ATOMIC);
        if (!vendor_class) {
            printk(KERN_ERR PFX "No memory for "
                   "ib_mad_mgmt_vendor_class\n");
            goto error2;
        }

        (*vendor_table)->vendor_class[vclass] = vendor_class;
    }
    for (i = 0; i < MAX_MGMT_OUI; i++) {
        /* Is there matching OUI for this vendor class ? */
        if (!memcmp((*vendor_table)->vendor_class[vclass]->oui[i],
                mad_reg_req->oui, 3)) {
            method = &(*vendor_table)->vendor_class[
                        vclass]->method_table[i];
            BUG_ON(!*method);
            goto check_in_use;
        }
    }
    for (i = 0; i < MAX_MGMT_OUI; i++) {
        /* OUI slot available ? */
        if (!is_vendor_oui((*vendor_table)->vendor_class[
                vclass]->oui[i])) {
            method = &(*vendor_table)->vendor_class[
                vclass]->method_table[i];
            BUG_ON(*method);
            /* Allocate method table for this OUI */
            if ((ret = allocate_method_table(method)))
                goto error3;
            memcpy((*vendor_table)->vendor_class[vclass]->oui[i],
                   mad_reg_req->oui, 3);
            goto check_in_use;
        }
    }
    printk(KERN_ERR PFX "All OUI slots in use\n");
    goto error3;

check_in_use:
    /* Now, make sure methods are not already in use */
    if (method_in_use(method, mad_reg_req))
        goto error4;

    /* Finally, add in methods being registered */
    for_each_set_bit(i, mad_reg_req->method_mask, IB_MGMT_MAX_METHODS)
        (*method)->agent[i] = agent_priv;

    return 0;

error4:
    /* Remove any methods for this mad agent */
    remove_methods_mad_agent(*method, agent_priv);
    /* Now, check to see if there are any methods in use */
    if (!check_method_table(*method)) {
        /* If not, release management method table */
        kfree(*method);
        *method = NULL;
    }
    ret = -EINVAL;
error3:
    if (vendor_class) {
        (*vendor_table)->vendor_class[vclass] = NULL;
        kfree(vendor_class);
    }
error2:
    if (vendor) {
        *vendor_table = NULL;
        kfree(vendor);
    }
error1:
    return ret;
}

static void remove_mad_reg_req(struct ib_mad_agent_private *agent_priv)
{
    struct ib_mad_port_private *port_priv;
    struct ib_mad_mgmt_class_table *class;
    struct ib_mad_mgmt_method_table *method;
    struct ib_mad_mgmt_vendor_class_table *vendor;
    struct ib_mad_mgmt_vendor_class *vendor_class;
    int index;
    u8 mgmt_class;

    /*
     * Was MAD registration request supplied
     * with original registration ?
     */
    if (!agent_priv->reg_req) {
        goto out;
    }

    port_priv = agent_priv->qp_info->port_priv;
    mgmt_class = convert_mgmt_class(agent_priv->reg_req->mgmt_class);
    class = port_priv->version[
            agent_priv->reg_req->mgmt_class_version].class;
    if (!class)
        goto vendor_check;

    method = class->method_table[mgmt_class];
    if (method) {
        /* Remove any methods for this mad agent */
        remove_methods_mad_agent(method, agent_priv);
        /* Now, check to see if there are any methods still in use */
        if (!check_method_table(method)) {
            /* If not, release management method table */
             kfree(method);
             class->method_table[mgmt_class] = NULL;
             /* Any management classes left ? */
            if (!check_class_table(class)) {
                /* If not, release management class table */
                kfree(class);
                port_priv->version[
                    agent_priv->reg_req->
                    mgmt_class_version].class = NULL;
            }
        }
    }

vendor_check:
    if (!is_vendor_class(mgmt_class))
        goto out;

    /* normalize mgmt_class to vendor range 2 */
    mgmt_class = vendor_class_index(agent_priv->reg_req->mgmt_class);
    vendor = port_priv->version[
            agent_priv->reg_req->mgmt_class_version].vendor;

    if (!vendor)
        goto out;

    vendor_class = vendor->vendor_class[mgmt_class];
    if (vendor_class) {
        index = find_vendor_oui(vendor_class, agent_priv->reg_req->oui);
        if (index < 0)
            goto out;
        method = vendor_class->method_table[index];
        if (method) {
            /* Remove any methods for this mad agent */
            remove_methods_mad_agent(method, agent_priv);
            /*
             * Now, check to see if there are
             * any methods still in use
             */
            if (!check_method_table(method)) {
                /* If not, release management method table */
                kfree(method);
                vendor_class->method_table[index] = NULL;
                memset(vendor_class->oui[index], 0, 3);
                /* Any OUIs left ? */
                if (!check_vendor_class(vendor_class)) {
                    /* If not, release vendor class table */
                    kfree(vendor_class);
                    vendor->vendor_class[mgmt_class] = NULL;
                    /* Any other vendor classes left ? */
                    if (!check_vendor_table(vendor)) {
                        kfree(vendor);
                        port_priv->version[
                            agent_priv->reg_req->
                            mgmt_class_version].
                            vendor = NULL;
                    }
                }
            }
        }
    }

out:
    return;
}

static struct ib_mad_agent_private *
find_mad_agent(struct ib_mad_port_private *port_priv,
           struct ib_mad *mad)
{
    struct ib_mad_agent_private *mad_agent = NULL;
    unsigned long flags;

    spin_lock_irqsave(&port_priv->reg_lock, flags);
    if (ib_response_mad(mad)) {
        u32 hi_tid;
        struct ib_mad_agent_private *entry;

        /*
         * Routing is based on high 32 bits of transaction ID
         * of MAD.
         */
        hi_tid = be64_to_cpu(mad->mad_hdr.tid) >> 32;
        list_for_each_entry(entry, &port_priv->agent_list, agent_list) {
            if (entry->agent.hi_tid == hi_tid) {
                mad_agent = entry;
                break;
            }
        }
    } else {
        struct ib_mad_mgmt_class_table *class;
        struct ib_mad_mgmt_method_table *method;
        struct ib_mad_mgmt_vendor_class_table *vendor;
        struct ib_mad_mgmt_vendor_class *vendor_class;
        struct ib_vendor_mad *vendor_mad;
        int index;

        /*
         * Routing is based on version, class, and method
         * For "newer" vendor MADs, also based on OUI
         */
        if (mad->mad_hdr.class_version >= MAX_MGMT_VERSION)
            goto out;
        if (!is_vendor_class(mad->mad_hdr.mgmt_class)) {
            class = port_priv->version[
                    mad->mad_hdr.class_version].class;
            if (!class)
                goto out;
            if (convert_mgmt_class(mad->mad_hdr.mgmt_class) >=
                IB_MGMT_MAX_METHODS)
                goto out;
            method = class->method_table[convert_mgmt_class(
                            mad->mad_hdr.mgmt_class)];
            if (method)
                mad_agent = method->agent[mad->mad_hdr.method &
                              ~IB_MGMT_METHOD_RESP];
        } else {
            vendor = port_priv->version[
                    mad->mad_hdr.class_version].vendor;
            if (!vendor)
                goto out;
            vendor_class = vendor->vendor_class[vendor_class_index(
                        mad->mad_hdr.mgmt_class)];
            if (!vendor_class)
                goto out;
            /* Find matching OUI */
            vendor_mad = (struct ib_vendor_mad *)mad;
            index = find_vendor_oui(vendor_class, vendor_mad->oui);
            if (index == -1)
                goto out;
            method = vendor_class->method_table[index];
            if (method) {
                mad_agent = method->agent[mad->mad_hdr.method &
                              ~IB_MGMT_METHOD_RESP];
            }
        }
    }

    if (mad_agent) {
        if (mad_agent->agent.recv_handler)
            atomic_inc(&mad_agent->refcount);
        else {
            printk(KERN_NOTICE PFX "No receive handler for client "
                   "%p on port %d\n",
                   &mad_agent->agent, port_priv->port_num);
            mad_agent = NULL;
        }
    }
out:
    spin_unlock_irqrestore(&port_priv->reg_lock, flags);

    return mad_agent;
}

static int validate_mad(struct ib_mad *mad, u32 qp_num)
{
    int valid = 0;

    /* Make sure MAD base version is understood */
    if (mad->mad_hdr.base_version != IB_MGMT_BASE_VERSION) {
        printk(KERN_ERR PFX "MAD received with unsupported base "
               "version %d\n", mad->mad_hdr.base_version);
        goto out;
    }

    /* Filter SMI packets sent to other than QP0 */
    if ((mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED) ||
        (mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)) {
        if (qp_num == 0)
            valid = 1;
    } else {
        /* Filter GSI packets sent to QP0 */
        if (qp_num != 0)
            valid = 1;
    }

out:
    return valid;
}

static int is_data_mad(struct ib_mad_agent_private *mad_agent_priv,
               struct ib_mad_hdr *mad_hdr)
{
    struct ib_rmpp_mad *rmpp_mad;

    rmpp_mad = (struct ib_rmpp_mad *)mad_hdr;
    return !mad_agent_priv->agent.rmpp_version ||
        !(ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) &
                    IB_MGMT_RMPP_FLAG_ACTIVE) ||
        (rmpp_mad->rmpp_hdr.rmpp_type == IB_MGMT_RMPP_TYPE_DATA);
}

static inline int rcv_has_same_class(struct ib_mad_send_wr_private *wr,
                     struct ib_mad_recv_wc *rwc)
{
    return ((struct ib_mad *)(wr->send_buf.mad))->mad_hdr.mgmt_class ==
        rwc->recv_buf.mad->mad_hdr.mgmt_class;
}

static inline int rcv_has_same_gid(struct ib_mad_agent_private *mad_agent_priv,
                   struct ib_mad_send_wr_private *wr,
                   struct ib_mad_recv_wc *rwc )
{
    struct ib_ah_attr attr;
    u8 send_resp, rcv_resp;
    union ib_gid sgid;
    struct ib_device *device = mad_agent_priv->agent.device;
    u8 port_num = mad_agent_priv->agent.port_num;
    u8 lmc;

    send_resp = ib_response_mad((struct ib_mad *)wr->send_buf.mad);
    rcv_resp = ib_response_mad(rwc->recv_buf.mad);

    if (send_resp == rcv_resp)
        /* both requests, or both responses. GIDs different */
        return 0;

    if (ib_query_ah(wr->send_buf.ah, &attr))
        /* Assume not equal, to avoid false positives. */
        return 0;

    if (!!(attr.ah_flags & IB_AH_GRH) !=
        !!(rwc->wc->wc_flags & IB_WC_GRH))
        /* one has GID, other does not.  Assume different */
        return 0;

    if (!send_resp && rcv_resp) {
        /* is request/response. */
        if (!(attr.ah_flags & IB_AH_GRH)) {
            if (ib_get_cached_lmc(device, port_num, &lmc))
                return 0;
            return (!lmc || !((attr.src_path_bits ^
                       rwc->wc->dlid_path_bits) &
                      ((1 << lmc) - 1)));
        } else {
            if (ib_get_cached_gid(device, port_num,
                          attr.grh.sgid_index, &sgid))
                return 0;
            return !memcmp(sgid.raw, rwc->recv_buf.grh->dgid.raw,
                       16);
        }
    }

    if (!(attr.ah_flags & IB_AH_GRH))
        return attr.dlid == rwc->wc->slid;
    else
        return !memcmp(attr.grh.dgid.raw, rwc->recv_buf.grh->sgid.raw,
                   16);
}

static inline int is_direct(u8 class)
{
    return (class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE);
}

struct ib_mad_send_wr_private*
ib_find_send_mad(struct ib_mad_agent_private *mad_agent_priv,
         struct ib_mad_recv_wc *wc)
{
    struct ib_mad_send_wr_private *wr;
    struct ib_mad *mad;

    mad = (struct ib_mad *)wc->recv_buf.mad;

    list_for_each_entry(wr, &mad_agent_priv->wait_list, agent_list) {
        if ((wr->tid == mad->mad_hdr.tid) &&
            rcv_has_same_class(wr, wc) &&
            /*
             * Don't check GID for direct routed MADs.
             * These might have permissive LIDs.
             */
            (is_direct(wc->recv_buf.mad->mad_hdr.mgmt_class) ||
             rcv_has_same_gid(mad_agent_priv, wr, wc)))
            return (wr->status == IB_WC_SUCCESS) ? wr : NULL;
    }

    /*
     * It's possible to receive the response before we've
     * been notified that the send has completed
     */
    list_for_each_entry(wr, &mad_agent_priv->send_list, agent_list) {
        if (is_data_mad(mad_agent_priv, wr->send_buf.mad) &&
            wr->tid == mad->mad_hdr.tid &&
            wr->timeout &&
            rcv_has_same_class(wr, wc) &&
            /*
             * Don't check GID for direct routed MADs.
             * These might have permissive LIDs.
             */
            (is_direct(wc->recv_buf.mad->mad_hdr.mgmt_class) ||
             rcv_has_same_gid(mad_agent_priv, wr, wc)))
            /* Verify request has not been canceled */
            return (wr->status == IB_WC_SUCCESS) ? wr : NULL;
    }
    return NULL;
}

void ib_mark_mad_done(struct ib_mad_send_wr_private *mad_send_wr)
{
    mad_send_wr->timeout = 0;
    if (mad_send_wr->refcount == 1)
        list_move_tail(&mad_send_wr->agent_list,
                  &mad_send_wr->mad_agent_priv->done_list);
}

static void ib_mad_complete_recv(struct ib_mad_agent_private *mad_agent_priv,
                 struct ib_mad_recv_wc *mad_recv_wc)
{
    struct ib_mad_send_wr_private *mad_send_wr;
    struct ib_mad_send_wc mad_send_wc;
    unsigned long flags;

    INIT_LIST_HEAD(&mad_recv_wc->rmpp_list);
    list_add(&mad_recv_wc->recv_buf.list, &mad_recv_wc->rmpp_list);
    if (mad_agent_priv->agent.rmpp_version) {
        mad_recv_wc = ib_process_rmpp_recv_wc(mad_agent_priv,
                              mad_recv_wc);
        if (!mad_recv_wc) {
            deref_mad_agent(mad_agent_priv);
            return;
        }
    }

    /* Complete corresponding request */
    if (ib_response_mad(mad_recv_wc->recv_buf.mad)) {
        spin_lock_irqsave(&mad_agent_priv->lock, flags);
        mad_send_wr = ib_find_send_mad(mad_agent_priv, mad_recv_wc);
        if (!mad_send_wr) {
            spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
            ib_free_recv_mad(mad_recv_wc);
            deref_mad_agent(mad_agent_priv);
            return;
        }
        ib_mark_mad_done(mad_send_wr);
        spin_unlock_irqrestore(&mad_agent_priv->lock, flags);

        /* Defined behavior is to complete response before request */
        mad_recv_wc->wc->wr_id = (unsigned long) &mad_send_wr->send_buf;
        mad_agent_priv->agent.recv_handler(&mad_agent_priv->agent,
                           mad_recv_wc);
        atomic_dec(&mad_agent_priv->refcount);

        mad_send_wc.status = IB_WC_SUCCESS;
        mad_send_wc.vendor_err = 0;
        mad_send_wc.send_buf = &mad_send_wr->send_buf;
        ib_mad_complete_send_wr(mad_send_wr, &mad_send_wc);
    } else {
        mad_agent_priv->agent.recv_handler(&mad_agent_priv->agent,
                           mad_recv_wc);
        deref_mad_agent(mad_agent_priv);
    }
}

static bool generate_unmatched_resp(struct ib_mad_private *recv,
                    struct ib_mad_private *response)
{
    if (recv->mad.mad.mad_hdr.method == IB_MGMT_METHOD_GET ||
        recv->mad.mad.mad_hdr.method == IB_MGMT_METHOD_SET) {
        memcpy(response, recv, sizeof *response);
        response->header.recv_wc.wc = &response->header.wc;
        response->header.recv_wc.recv_buf.mad = &response->mad.mad;
        response->header.recv_wc.recv_buf.grh = &response->grh;
        response->mad.mad.mad_hdr.method = IB_MGMT_METHOD_GET_RESP;
        response->mad.mad.mad_hdr.status =
            cpu_to_be16(IB_MGMT_MAD_STATUS_UNSUPPORTED_METHOD_ATTRIB);
        if (recv->mad.mad.mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
            response->mad.mad.mad_hdr.status |= IB_SMP_DIRECTION;

        return true;
    } else {
        return false;
    }
}
static void ib_mad_recv_done_handler(struct ib_mad_port_private *port_priv,
                     struct ib_wc *wc)
{
    struct ib_mad_qp_info *qp_info;
    struct ib_mad_private_header *mad_priv_hdr;
    struct ib_mad_private *recv, *response = NULL;
    struct ib_mad_list_head *mad_list;
    struct ib_mad_agent_private *mad_agent;
    int port_num;
    int ret = IB_MAD_RESULT_SUCCESS;

    mad_list = (struct ib_mad_list_head *)(unsigned long)wc->wr_id;
    qp_info = mad_list->mad_queue->qp_info;
    dequeue_mad(mad_list);

    mad_priv_hdr = container_of(mad_list, struct ib_mad_private_header,
                    mad_list);
    recv = container_of(mad_priv_hdr, struct ib_mad_private, header);
    ib_dma_unmap_single(port_priv->device,
                recv->header.mapping,
                sizeof(struct ib_mad_private) -
                  sizeof(struct ib_mad_private_header),
                DMA_FROM_DEVICE);

    /* Setup MAD receive work completion from "normal" work completion */
    recv->header.wc = *wc;
    recv->header.recv_wc.wc = &recv->header.wc;
    recv->header.recv_wc.mad_len = sizeof(struct ib_mad);
    recv->header.recv_wc.recv_buf.mad = &recv->mad.mad;
    recv->header.recv_wc.recv_buf.grh = &recv->grh;

    if (atomic_read(&qp_info->snoop_count))
        snoop_recv(qp_info, &recv->header.recv_wc, IB_MAD_SNOOP_RECVS);

    /* Validate MAD */
    if (!validate_mad(&recv->mad.mad, qp_info->qp->qp_num))
        goto out;

    response = kmem_cache_alloc(ib_mad_cache, GFP_KERNEL);
    if (!response) {
        printk(KERN_ERR PFX "ib_mad_recv_done_handler no memory "
               "for response buffer\n");
        goto out;
    }

    if (port_priv->device->node_type == RDMA_NODE_IB_SWITCH)
        port_num = wc->port_num;
    else
        port_num = port_priv->port_num;

    if (recv->mad.mad.mad_hdr.mgmt_class ==
        IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
        enum smi_forward_action retsmi;

        if (smi_handle_dr_smp_recv(&recv->mad.smp,
                       port_priv->device->node_type,
                       port_num,
                       port_priv->device->phys_port_cnt) ==
                       IB_SMI_DISCARD)
            goto out;

        retsmi = smi_check_forward_dr_smp(&recv->mad.smp);
        if (retsmi == IB_SMI_LOCAL)
            goto local;

        if (retsmi == IB_SMI_SEND) { /* don't forward */
            if (smi_handle_dr_smp_send(&recv->mad.smp,
                           port_priv->device->node_type,
                           port_num) == IB_SMI_DISCARD)
                goto out;

            if (smi_check_local_smp(&recv->mad.smp, port_priv->device) == IB_SMI_DISCARD)
                goto out;
        } else if (port_priv->device->node_type == RDMA_NODE_IB_SWITCH) {
            /* forward case for switches */
            memcpy(response, recv, sizeof(*response));
            response->header.recv_wc.wc = &response->header.wc;
            response->header.recv_wc.recv_buf.mad = &response->mad.mad;
            response->header.recv_wc.recv_buf.grh = &response->grh;

            agent_send_response(&response->mad.mad,
                        &response->grh, wc,
                        port_priv->device,
                        smi_get_fwd_port(&recv->mad.smp),
                        qp_info->qp->qp_num);

            goto out;
        }
    }

local:
    /* Give driver "right of first refusal" on incoming MAD */
    if (port_priv->device->process_mad) {
        ret = port_priv->device->process_mad(port_priv->device, 0,
                             port_priv->port_num,
                             wc, &recv->grh,
                             &recv->mad.mad,
                             &response->mad.mad);
        if (ret & IB_MAD_RESULT_SUCCESS) {
            if (ret & IB_MAD_RESULT_CONSUMED)
                goto out;
            if (ret & IB_MAD_RESULT_REPLY) {
                agent_send_response(&response->mad.mad,
                            &recv->grh, wc,
                            port_priv->device,
                            port_num,
                            qp_info->qp->qp_num);
                goto out;
            }
        }
    }

    mad_agent = find_mad_agent(port_priv, &recv->mad.mad);
    if (mad_agent) {
        ib_mad_complete_recv(mad_agent, &recv->header.recv_wc);
        /*
         * recv is freed up in error cases in ib_mad_complete_recv
         * or via recv_handler in ib_mad_complete_recv()
         */
        recv = NULL;
    } else if ((ret & IB_MAD_RESULT_SUCCESS) &&
           generate_unmatched_resp(recv, response)) {
        agent_send_response(&response->mad.mad, &recv->grh, wc,
                    port_priv->device, port_num, qp_info->qp->qp_num);
    }

out:
    /* Post another receive request for this QP */
    if (response) {
        ib_mad_post_receive_mads(qp_info, response);
        if (recv)
            kmem_cache_free(ib_mad_cache, recv);
    } else
        ib_mad_post_receive_mads(qp_info, recv);
}

static void adjust_timeout(struct ib_mad_agent_private *mad_agent_priv)
{
    struct ib_mad_send_wr_private *mad_send_wr;
    unsigned long delay;

    if (list_empty(&mad_agent_priv->wait_list)) {
        cancel_delayed_work(&mad_agent_priv->timed_work);
    } else {
        mad_send_wr = list_entry(mad_agent_priv->wait_list.next,
                     struct ib_mad_send_wr_private,
                     agent_list);

        if (time_after(mad_agent_priv->timeout,
                   mad_send_wr->timeout)) {
            mad_agent_priv->timeout = mad_send_wr->timeout;
            delay = mad_send_wr->timeout - jiffies;
            if ((long)delay <= 0)
                delay = 1;
            mod_delayed_work(mad_agent_priv->qp_info->port_priv->wq,
                     &mad_agent_priv->timed_work, delay);
        }
    }
}

static void wait_for_response(struct ib_mad_send_wr_private *mad_send_wr)
{
    struct ib_mad_agent_private *mad_agent_priv;
    struct ib_mad_send_wr_private *temp_mad_send_wr;
    struct list_head *list_item;
    unsigned long delay;

    mad_agent_priv = mad_send_wr->mad_agent_priv;
    list_del(&mad_send_wr->agent_list);

    delay = mad_send_wr->timeout;
    mad_send_wr->timeout += jiffies;

    if (delay) {
        list_for_each_prev(list_item, &mad_agent_priv->wait_list) {
            temp_mad_send_wr = list_entry(list_item,
                        struct ib_mad_send_wr_private,
                        agent_list);
            if (time_after(mad_send_wr->timeout,
                       temp_mad_send_wr->timeout))
                break;
        }
    }
    else
        list_item = &mad_agent_priv->wait_list;
    list_add(&mad_send_wr->agent_list, list_item);

    /* Reschedule a work item if we have a shorter timeout */
    if (mad_agent_priv->wait_list.next == &mad_send_wr->agent_list)
        mod_delayed_work(mad_agent_priv->qp_info->port_priv->wq,
                 &mad_agent_priv->timed_work, delay);
}

void ib_reset_mad_timeout(struct ib_mad_send_wr_private *mad_send_wr,
              int timeout_ms)
{
    mad_send_wr->timeout = msecs_to_jiffies(timeout_ms);
    wait_for_response(mad_send_wr);
}

/*
 * Process a send work completion
 */
void ib_mad_complete_send_wr(struct ib_mad_send_wr_private *mad_send_wr,
                 struct ib_mad_send_wc *mad_send_wc)
{
    struct ib_mad_agent_private *mad_agent_priv;
    unsigned long           flags;
    int             ret;

    mad_agent_priv = mad_send_wr->mad_agent_priv;
    spin_lock_irqsave(&mad_agent_priv->lock, flags);
    if (mad_agent_priv->agent.rmpp_version) {
        ret = ib_process_rmpp_send_wc(mad_send_wr, mad_send_wc);
        if (ret == IB_RMPP_RESULT_CONSUMED)
            goto done;
    } else
        ret = IB_RMPP_RESULT_UNHANDLED;

    if (mad_send_wc->status != IB_WC_SUCCESS &&
        mad_send_wr->status == IB_WC_SUCCESS) {
        mad_send_wr->status = mad_send_wc->status;
        mad_send_wr->refcount -= (mad_send_wr->timeout > 0);
    }

    if (--mad_send_wr->refcount > 0) {
        if (mad_send_wr->refcount == 1 && mad_send_wr->timeout &&
            mad_send_wr->status == IB_WC_SUCCESS) {
            wait_for_response(mad_send_wr);
        }
        goto done;
    }

    /* Remove send from MAD agent and notify client of completion */
    list_del(&mad_send_wr->agent_list);
    adjust_timeout(mad_agent_priv);
    spin_unlock_irqrestore(&mad_agent_priv->lock, flags);

    if (mad_send_wr->status != IB_WC_SUCCESS )
        mad_send_wc->status = mad_send_wr->status;
    if (ret == IB_RMPP_RESULT_INTERNAL)
        ib_rmpp_send_handler(mad_send_wc);
    else
        mad_agent_priv->agent.send_handler(&mad_agent_priv->agent,
                           mad_send_wc);

    /* Release reference on agent taken when sending */
    deref_mad_agent(mad_agent_priv);
    return;
done:
    spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
}

static void ib_mad_send_done_handler(struct ib_mad_port_private *port_priv,
                     struct ib_wc *wc)
{
    struct ib_mad_send_wr_private   *mad_send_wr, *queued_send_wr;
    struct ib_mad_list_head     *mad_list;
    struct ib_mad_qp_info       *qp_info;
    struct ib_mad_queue     *send_queue;
    struct ib_send_wr       *bad_send_wr;
    struct ib_mad_send_wc       mad_send_wc;
    unsigned long flags;
    int ret;

    mad_list = (struct ib_mad_list_head *)(unsigned long)wc->wr_id;
    mad_send_wr = container_of(mad_list, struct ib_mad_send_wr_private,
                   mad_list);
    send_queue = mad_list->mad_queue;
    qp_info = send_queue->qp_info;

retry:
    ib_dma_unmap_single(mad_send_wr->send_buf.mad_agent->device,
                mad_send_wr->header_mapping,
                mad_send_wr->sg_list[0].length, DMA_TO_DEVICE);
    ib_dma_unmap_single(mad_send_wr->send_buf.mad_agent->device,
                mad_send_wr->payload_mapping,
                mad_send_wr->sg_list[1].length, DMA_TO_DEVICE);
    queued_send_wr = NULL;
    spin_lock_irqsave(&send_queue->lock, flags);
    list_del(&mad_list->list);

    /* Move queued send to the send queue */
    if (send_queue->count-- > send_queue->max_active) {
        mad_list = container_of(qp_info->overflow_list.next,
                    struct ib_mad_list_head, list);
        queued_send_wr = container_of(mad_list,
                    struct ib_mad_send_wr_private,
                    mad_list);
        list_move_tail(&mad_list->list, &send_queue->list);
    }
    spin_unlock_irqrestore(&send_queue->lock, flags);

    mad_send_wc.send_buf = &mad_send_wr->send_buf;
    mad_send_wc.status = wc->status;
    mad_send_wc.vendor_err = wc->vendor_err;
    if (atomic_read(&qp_info->snoop_count))
        snoop_send(qp_info, &mad_send_wr->send_buf, &mad_send_wc,
               IB_MAD_SNOOP_SEND_COMPLETIONS);
    ib_mad_complete_send_wr(mad_send_wr, &mad_send_wc);

    if (queued_send_wr) {
        ret = ib_post_send(qp_info->qp, &queued_send_wr->send_wr,
                   &bad_send_wr);
        if (ret) {
            printk(KERN_ERR PFX "ib_post_send failed: %d\n", ret);
            mad_send_wr = queued_send_wr;
            wc->status = IB_WC_LOC_QP_OP_ERR;
            goto retry;
        }
    }
}

static void mark_sends_for_retry(struct ib_mad_qp_info *qp_info)
{
    struct ib_mad_send_wr_private *mad_send_wr;
    struct ib_mad_list_head *mad_list;
    unsigned long flags;

    spin_lock_irqsave(&qp_info->send_queue.lock, flags);
    list_for_each_entry(mad_list, &qp_info->send_queue.list, list) {
        mad_send_wr = container_of(mad_list,
                       struct ib_mad_send_wr_private,
                       mad_list);
        mad_send_wr->retry = 1;
    }
    spin_unlock_irqrestore(&qp_info->send_queue.lock, flags);
}

static void mad_error_handler(struct ib_mad_port_private *port_priv,
                  struct ib_wc *wc)
{
    struct ib_mad_list_head *mad_list;
    struct ib_mad_qp_info *qp_info;
    struct ib_mad_send_wr_private *mad_send_wr;
    int ret;

    /* Determine if failure was a send or receive */
    mad_list = (struct ib_mad_list_head *)(unsigned long)wc->wr_id;
    qp_info = mad_list->mad_queue->qp_info;
    if (mad_list->mad_queue == &qp_info->recv_queue)
        /*
         * Receive errors indicate that the QP has entered the error
         * state - error handling/shutdown code will cleanup
         */
        return;

    /*
     * Send errors will transition the QP to SQE - move
     * QP to RTS and repost flushed work requests
     */
    mad_send_wr = container_of(mad_list, struct ib_mad_send_wr_private,
                   mad_list);
    if (wc->status == IB_WC_WR_FLUSH_ERR) {
        if (mad_send_wr->retry) {
            /* Repost send */
            struct ib_send_wr *bad_send_wr;

            mad_send_wr->retry = 0;
            ret = ib_post_send(qp_info->qp, &mad_send_wr->send_wr,
                    &bad_send_wr);
            if (ret)
                ib_mad_send_done_handler(port_priv, wc);
        } else
            ib_mad_send_done_handler(port_priv, wc);
    } else {
        struct ib_qp_attr *attr;

        /* Transition QP to RTS and fail offending send */
        attr = kmalloc(sizeof *attr, GFP_KERNEL);
        if (attr) {
            attr->qp_state = IB_QPS_RTS;
            attr->cur_qp_state = IB_QPS_SQE;
            ret = ib_modify_qp(qp_info->qp, attr,
                       IB_QP_STATE | IB_QP_CUR_STATE);
            kfree(attr);
            if (ret)
                printk(KERN_ERR PFX "mad_error_handler - "
                       "ib_modify_qp to RTS : %d\n", ret);
            else
                mark_sends_for_retry(qp_info);
        }
        ib_mad_send_done_handler(port_priv, wc);
    }
}

/*
 * IB MAD completion callback
 */
static void ib_mad_completion_handler(struct work_struct *work)
{
    struct ib_mad_port_private *port_priv;
    struct ib_wc wc;

    port_priv = container_of(work, struct ib_mad_port_private, work);
    ib_req_notify_cq(port_priv->cq, IB_CQ_NEXT_COMP);

    while (ib_poll_cq(port_priv->cq, 1, &wc) == 1) {
        if (wc.status == IB_WC_SUCCESS) {
            switch (wc.opcode) {
            case IB_WC_SEND:
                ib_mad_send_done_handler(port_priv, &wc);
                break;
            case IB_WC_RECV:
                ib_mad_recv_done_handler(port_priv, &wc);
                break;
            default:
                BUG_ON(1);
                break;
            }
        } else
            mad_error_handler(port_priv, &wc);
    }
}

static void cancel_mads(struct ib_mad_agent_private *mad_agent_priv)
{
    unsigned long flags;
    struct ib_mad_send_wr_private *mad_send_wr, *temp_mad_send_wr;
    struct ib_mad_send_wc mad_send_wc;
    struct list_head cancel_list;

    INIT_LIST_HEAD(&cancel_list);

    spin_lock_irqsave(&mad_agent_priv->lock, flags);
    list_for_each_entry_safe(mad_send_wr, temp_mad_send_wr,
                 &mad_agent_priv->send_list, agent_list) {
        if (mad_send_wr->status == IB_WC_SUCCESS) {
            mad_send_wr->status = IB_WC_WR_FLUSH_ERR;
            mad_send_wr->refcount -= (mad_send_wr->timeout > 0);
        }
    }

    /* Empty wait list to prevent receives from finding a request */
    list_splice_init(&mad_agent_priv->wait_list, &cancel_list);
    spin_unlock_irqrestore(&mad_agent_priv->lock, flags);

    /* Report all cancelled requests */
    mad_send_wc.status = IB_WC_WR_FLUSH_ERR;
    mad_send_wc.vendor_err = 0;

    list_for_each_entry_safe(mad_send_wr, temp_mad_send_wr,
                 &cancel_list, agent_list) {
        mad_send_wc.send_buf = &mad_send_wr->send_buf;
        list_del(&mad_send_wr->agent_list);
        mad_agent_priv->agent.send_handler(&mad_agent_priv->agent,
                           &mad_send_wc);
        atomic_dec(&mad_agent_priv->refcount);
    }
}

static struct ib_mad_send_wr_private*
find_send_wr(struct ib_mad_agent_private *mad_agent_priv,
         struct ib_mad_send_buf *send_buf)
{
    struct ib_mad_send_wr_private *mad_send_wr;

    list_for_each_entry(mad_send_wr, &mad_agent_priv->wait_list,
                agent_list) {
        if (&mad_send_wr->send_buf == send_buf)
            return mad_send_wr;
    }

    list_for_each_entry(mad_send_wr, &mad_agent_priv->send_list,
                agent_list) {
        if (is_data_mad(mad_agent_priv, mad_send_wr->send_buf.mad) &&
            &mad_send_wr->send_buf == send_buf)
            return mad_send_wr;
    }
    return NULL;
}

int ib_modify_mad(struct ib_mad_agent *mad_agent,
          struct ib_mad_send_buf *send_buf, u32 timeout_ms)
{
    struct ib_mad_agent_private *mad_agent_priv;
    struct ib_mad_send_wr_private *mad_send_wr;
    unsigned long flags;
    int active;

    mad_agent_priv = container_of(mad_agent, struct ib_mad_agent_private,
                      agent);
    spin_lock_irqsave(&mad_agent_priv->lock, flags);
    mad_send_wr = find_send_wr(mad_agent_priv, send_buf);
    if (!mad_send_wr || mad_send_wr->status != IB_WC_SUCCESS) {
        spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
        return -EINVAL;
    }

    active = (!mad_send_wr->timeout || mad_send_wr->refcount > 1);
    if (!timeout_ms) {
        mad_send_wr->status = IB_WC_WR_FLUSH_ERR;
        mad_send_wr->refcount -= (mad_send_wr->timeout > 0);
    }

    mad_send_wr->send_buf.timeout_ms = timeout_ms;
    if (active)
        mad_send_wr->timeout = msecs_to_jiffies(timeout_ms);
    else
        ib_reset_mad_timeout(mad_send_wr, timeout_ms);

    spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
    return 0;
}
EXPORT_SYMBOL(ib_modify_mad);

void ib_cancel_mad(struct ib_mad_agent *mad_agent,
           struct ib_mad_send_buf *send_buf)
{
    ib_modify_mad(mad_agent, send_buf, 0);
}
EXPORT_SYMBOL(ib_cancel_mad);

static void local_completions(struct work_struct *work)
{
    struct ib_mad_agent_private *mad_agent_priv;
    struct ib_mad_local_private *local;
    struct ib_mad_agent_private *recv_mad_agent;
    unsigned long flags;
    int free_mad;
    struct ib_wc wc;
    struct ib_mad_send_wc mad_send_wc;

    mad_agent_priv =
        container_of(work, struct ib_mad_agent_private, local_work);

    spin_lock_irqsave(&mad_agent_priv->lock, flags);
    while (!list_empty(&mad_agent_priv->local_list)) {
        local = list_entry(mad_agent_priv->local_list.next,
                   struct ib_mad_local_private,
                   completion_list);
        list_del(&local->completion_list);
        spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
        free_mad = 0;
        if (local->mad_priv) {
            recv_mad_agent = local->recv_mad_agent;
            if (!recv_mad_agent) {
                printk(KERN_ERR PFX "No receive MAD agent for local completion\n");
                free_mad = 1;
                goto local_send_completion;
            }

            /*
             * Defined behavior is to complete response
             * before request
             */
            build_smp_wc(recv_mad_agent->agent.qp,
                     (unsigned long) local->mad_send_wr,
                     be16_to_cpu(IB_LID_PERMISSIVE),
                     0, recv_mad_agent->agent.port_num, &wc);

            local->mad_priv->header.recv_wc.wc = &wc;
            local->mad_priv->header.recv_wc.mad_len =
                        sizeof(struct ib_mad);
            INIT_LIST_HEAD(&local->mad_priv->header.recv_wc.rmpp_list);
            list_add(&local->mad_priv->header.recv_wc.recv_buf.list,
                 &local->mad_priv->header.recv_wc.rmpp_list);
            local->mad_priv->header.recv_wc.recv_buf.grh = NULL;
            local->mad_priv->header.recv_wc.recv_buf.mad =
                        &local->mad_priv->mad.mad;
            if (atomic_read(&recv_mad_agent->qp_info->snoop_count))
                snoop_recv(recv_mad_agent->qp_info,
                      &local->mad_priv->header.recv_wc,
                       IB_MAD_SNOOP_RECVS);
            recv_mad_agent->agent.recv_handler(
                        &recv_mad_agent->agent,
                        &local->mad_priv->header.recv_wc);
            spin_lock_irqsave(&recv_mad_agent->lock, flags);
            atomic_dec(&recv_mad_agent->refcount);
            spin_unlock_irqrestore(&recv_mad_agent->lock, flags);
        }

local_send_completion:
        /* Complete send */
        mad_send_wc.status = IB_WC_SUCCESS;
        mad_send_wc.vendor_err = 0;
        mad_send_wc.send_buf = &local->mad_send_wr->send_buf;
        if (atomic_read(&mad_agent_priv->qp_info->snoop_count))
            snoop_send(mad_agent_priv->qp_info,
                   &local->mad_send_wr->send_buf,
                   &mad_send_wc, IB_MAD_SNOOP_SEND_COMPLETIONS);
        mad_agent_priv->agent.send_handler(&mad_agent_priv->agent,
                           &mad_send_wc);

        spin_lock_irqsave(&mad_agent_priv->lock, flags);
        atomic_dec(&mad_agent_priv->refcount);
        if (free_mad)
            kmem_cache_free(ib_mad_cache, local->mad_priv);
        kfree(local);
    }
    spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
}

static int retry_send(struct ib_mad_send_wr_private *mad_send_wr)
{
    int ret;

    if (!mad_send_wr->retries_left)
        return -ETIMEDOUT;

    mad_send_wr->retries_left--;
    mad_send_wr->send_buf.retries++;

    mad_send_wr->timeout = msecs_to_jiffies(mad_send_wr->send_buf.timeout_ms);

    if (mad_send_wr->mad_agent_priv->agent.rmpp_version) {
        ret = ib_retry_rmpp(mad_send_wr);
        switch (ret) {
        case IB_RMPP_RESULT_UNHANDLED:
            ret = ib_send_mad(mad_send_wr);
            break;
        case IB_RMPP_RESULT_CONSUMED:
            ret = 0;
            break;
        default:
            ret = -ECOMM;
            break;
        }
    } else
        ret = ib_send_mad(mad_send_wr);

    if (!ret) {
        mad_send_wr->refcount++;
        list_add_tail(&mad_send_wr->agent_list,
                  &mad_send_wr->mad_agent_priv->send_list);
    }
    return ret;
}

static void timeout_sends(struct work_struct *work)
{
    struct ib_mad_agent_private *mad_agent_priv;
    struct ib_mad_send_wr_private *mad_send_wr;
    struct ib_mad_send_wc mad_send_wc;
    unsigned long flags, delay;

    mad_agent_priv = container_of(work, struct ib_mad_agent_private,
                      timed_work.work);
    mad_send_wc.vendor_err = 0;

    spin_lock_irqsave(&mad_agent_priv->lock, flags);
    while (!list_empty(&mad_agent_priv->wait_list)) {
        mad_send_wr = list_entry(mad_agent_priv->wait_list.next,
                     struct ib_mad_send_wr_private,
                     agent_list);

        if (time_after(mad_send_wr->timeout, jiffies)) {
            delay = mad_send_wr->timeout - jiffies;
            if ((long)delay <= 0)
                delay = 1;
            queue_delayed_work(mad_agent_priv->qp_info->
                       port_priv->wq,
                       &mad_agent_priv->timed_work, delay);
            break;
        }

        list_del(&mad_send_wr->agent_list);
        if (mad_send_wr->status == IB_WC_SUCCESS &&
            !retry_send(mad_send_wr))
            continue;

        spin_unlock_irqrestore(&mad_agent_priv->lock, flags);

        if (mad_send_wr->status == IB_WC_SUCCESS)
            mad_send_wc.status = IB_WC_RESP_TIMEOUT_ERR;
        else
            mad_send_wc.status = mad_send_wr->status;
        mad_send_wc.send_buf = &mad_send_wr->send_buf;
        mad_agent_priv->agent.send_handler(&mad_agent_priv->agent,
                           &mad_send_wc);

        atomic_dec(&mad_agent_priv->refcount);
        spin_lock_irqsave(&mad_agent_priv->lock, flags);
    }
    spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
}

static void ib_mad_thread_completion_handler(struct ib_cq *cq, void *arg)
{
    struct ib_mad_port_private *port_priv = cq->cq_context;
    unsigned long flags;

    spin_lock_irqsave(&ib_mad_port_list_lock, flags);
    if (!list_empty(&port_priv->port_list))
        queue_work(port_priv->wq, &port_priv->work);
    spin_unlock_irqrestore(&ib_mad_port_list_lock, flags);
}

/*
 * Allocate receive MADs and post receive WRs for them
 */
static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info,
                    struct ib_mad_private *mad)
{
    unsigned long flags;
    int post, ret;
    struct ib_mad_private *mad_priv;
    struct ib_sge sg_list;
    struct ib_recv_wr recv_wr, *bad_recv_wr;
    struct ib_mad_queue *recv_queue = &qp_info->recv_queue;

    /* Initialize common scatter list fields */
    sg_list.length = sizeof *mad_priv - sizeof mad_priv->header;
    sg_list.lkey = (*qp_info->port_priv->mr).lkey;

    /* Initialize common receive WR fields */
    recv_wr.next = NULL;
    recv_wr.sg_list = &sg_list;
    recv_wr.num_sge = 1;

    do {
        /* Allocate and map receive buffer */
        if (mad) {
            mad_priv = mad;
            mad = NULL;
        } else {
            mad_priv = kmem_cache_alloc(ib_mad_cache, GFP_KERNEL);
            if (!mad_priv) {
                printk(KERN_ERR PFX "No memory for receive buffer\n");
                ret = -ENOMEM;
                break;
            }
        }
        sg_list.addr = ib_dma_map_single(qp_info->port_priv->device,
                         &mad_priv->grh,
                         sizeof *mad_priv -
                           sizeof mad_priv->header,
                         DMA_FROM_DEVICE);
        mad_priv->header.mapping = sg_list.addr;
        recv_wr.wr_id = (unsigned long)&mad_priv->header.mad_list;
        mad_priv->header.mad_list.mad_queue = recv_queue;

        /* Post receive WR */
        spin_lock_irqsave(&recv_queue->lock, flags);
        post = (++recv_queue->count < recv_queue->max_active);
        list_add_tail(&mad_priv->header.mad_list.list, &recv_queue->list);
        spin_unlock_irqrestore(&recv_queue->lock, flags);
        ret = ib_post_recv(qp_info->qp, &recv_wr, &bad_recv_wr);
        if (ret) {
            spin_lock_irqsave(&recv_queue->lock, flags);
            list_del(&mad_priv->header.mad_list.list);
            recv_queue->count--;
            spin_unlock_irqrestore(&recv_queue->lock, flags);
            ib_dma_unmap_single(qp_info->port_priv->device,
                        mad_priv->header.mapping,
                        sizeof *mad_priv -
                          sizeof mad_priv->header,
                        DMA_FROM_DEVICE);
            kmem_cache_free(ib_mad_cache, mad_priv);
            printk(KERN_ERR PFX "ib_post_recv failed: %d\n", ret);
            break;
        }
    } while (post);

    return ret;
}

/*
 * Return all the posted receive MADs
 */
static void cleanup_recv_queue(struct ib_mad_qp_info *qp_info)
{
    struct ib_mad_private_header *mad_priv_hdr;
    struct ib_mad_private *recv;
    struct ib_mad_list_head *mad_list;

    if (!qp_info->qp)
        return;

    while (!list_empty(&qp_info->recv_queue.list)) {

        mad_list = list_entry(qp_info->recv_queue.list.next,
                      struct ib_mad_list_head, list);
        mad_priv_hdr = container_of(mad_list,
                        struct ib_mad_private_header,
                        mad_list);
        recv = container_of(mad_priv_hdr, struct ib_mad_private,
                    header);

        /* Remove from posted receive MAD list */
        list_del(&mad_list->list);

        ib_dma_unmap_single(qp_info->port_priv->device,
                    recv->header.mapping,
                    sizeof(struct ib_mad_private) -
                      sizeof(struct ib_mad_private_header),
                    DMA_FROM_DEVICE);
        kmem_cache_free(ib_mad_cache, recv);
    }

    qp_info->recv_queue.count = 0;
}

/*
 * Start the port
 */
static int ib_mad_port_start(struct ib_mad_port_private *port_priv)
{
    int ret, i;
    struct ib_qp_attr *attr;
    struct ib_qp *qp;

    attr = kmalloc(sizeof *attr, GFP_KERNEL);
    if (!attr) {
        printk(KERN_ERR PFX "Couldn't kmalloc ib_qp_attr\n");
        return -ENOMEM;
    }

    for (i = 0; i < IB_MAD_QPS_CORE; i++) {
        qp = port_priv->qp_info[i].qp;
        if (!qp)
            continue;

        /*
         * PKey index for QP1 is irrelevant but
         * one is needed for the Reset to Init transition
         */
        attr->qp_state = IB_QPS_INIT;
        attr->pkey_index = 0;
        attr->qkey = (qp->qp_num == 0) ? 0 : IB_QP1_QKEY;
        ret = ib_modify_qp(qp, attr, IB_QP_STATE |
                         IB_QP_PKEY_INDEX | IB_QP_QKEY);
        if (ret) {
            printk(KERN_ERR PFX "Couldn't change QP%d state to "
                   "INIT: %d\n", i, ret);
            goto out;
        }

        attr->qp_state = IB_QPS_RTR;
        ret = ib_modify_qp(qp, attr, IB_QP_STATE);
        if (ret) {
            printk(KERN_ERR PFX "Couldn't change QP%d state to "
                   "RTR: %d\n", i, ret);
            goto out;
        }

        attr->qp_state = IB_QPS_RTS;
        attr->sq_psn = IB_MAD_SEND_Q_PSN;
        ret = ib_modify_qp(qp, attr, IB_QP_STATE | IB_QP_SQ_PSN);
        if (ret) {
            printk(KERN_ERR PFX "Couldn't change QP%d state to "
                   "RTS: %d\n", i, ret);
            goto out;
        }
    }

    ret = ib_req_notify_cq(port_priv->cq, IB_CQ_NEXT_COMP);
    if (ret) {
        printk(KERN_ERR PFX "Failed to request completion "
               "notification: %d\n", ret);
        goto out;
    }

    for (i = 0; i < IB_MAD_QPS_CORE; i++) {
        if (!port_priv->qp_info[i].qp)
            continue;

        ret = ib_mad_post_receive_mads(&port_priv->qp_info[i], NULL);
        if (ret) {
            printk(KERN_ERR PFX "Couldn't post receive WRs\n");
            goto out;
        }
    }
out:
    kfree(attr);
    return ret;
}

static void qp_event_handler(struct ib_event *event, void *qp_context)
{
    struct ib_mad_qp_info   *qp_info = qp_context;

    /* It's worse than that! He's dead, Jim! */
    printk(KERN_ERR PFX "Fatal error (%d) on MAD QP (%d)\n",
        event->event, qp_info->qp->qp_num);
}

static void init_mad_queue(struct ib_mad_qp_info *qp_info,
               struct ib_mad_queue *mad_queue)
{
    mad_queue->qp_info = qp_info;
    mad_queue->count = 0;
    spin_lock_init(&mad_queue->lock);
    INIT_LIST_HEAD(&mad_queue->list);
}

static void init_mad_qp(struct ib_mad_port_private *port_priv,
            struct ib_mad_qp_info *qp_info)
{
    qp_info->port_priv = port_priv;
    init_mad_queue(qp_info, &qp_info->send_queue);
    init_mad_queue(qp_info, &qp_info->recv_queue);
    INIT_LIST_HEAD(&qp_info->overflow_list);
    spin_lock_init(&qp_info->snoop_lock);
    qp_info->snoop_table = NULL;
    qp_info->snoop_table_size = 0;
    atomic_set(&qp_info->snoop_count, 0);
}

static int create_mad_qp(struct ib_mad_qp_info *qp_info,
             enum ib_qp_type qp_type)
{
    struct ib_qp_init_attr  qp_init_attr;
    int ret;

    memset(&qp_init_attr, 0, sizeof qp_init_attr);
    qp_init_attr.send_cq = qp_info->port_priv->cq;
    qp_init_attr.recv_cq = qp_info->port_priv->cq;
    qp_init_attr.sq_sig_type = IB_SIGNAL_ALL_WR;
    qp_init_attr.cap.max_send_wr = mad_sendq_size;
    qp_init_attr.cap.max_recv_wr = mad_recvq_size;
    qp_init_attr.cap.max_send_sge = IB_MAD_SEND_REQ_MAX_SG;
    qp_init_attr.cap.max_recv_sge = IB_MAD_RECV_REQ_MAX_SG;
    qp_init_attr.qp_type = qp_type;
    qp_init_attr.port_num = qp_info->port_priv->port_num;
    qp_init_attr.qp_context = qp_info;
    qp_init_attr.event_handler = qp_event_handler;
    qp_info->qp = ib_create_qp(qp_info->port_priv->pd, &qp_init_attr);
    if (IS_ERR(qp_info->qp)) {
        printk(KERN_ERR PFX "Couldn't create ib_mad QP%d\n",
               get_spl_qp_index(qp_type));
        ret = PTR_ERR(qp_info->qp);
        goto error;
    }
    /* Use minimum queue sizes unless the CQ is resized */
    qp_info->send_queue.max_active = mad_sendq_size;
    qp_info->recv_queue.max_active = mad_recvq_size;
    return 0;

error:
    return ret;
}

static void destroy_mad_qp(struct ib_mad_qp_info *qp_info)
{
    if (!qp_info->qp)
        return;

    ib_destroy_qp(qp_info->qp);
    kfree(qp_info->snoop_table);
}

/*
 * Open the port
 * Create the QP, PD, MR, and CQ if needed
 */
static int ib_mad_port_open(struct ib_device *device,
                int port_num)
{
    int ret, cq_size;
    struct ib_mad_port_private *port_priv;
    unsigned long flags;
    char name[sizeof "ib_mad123"];
    int has_smi;

    /* Create new device info */
    port_priv = kzalloc(sizeof *port_priv, GFP_KERNEL);
    if (!port_priv) {
        printk(KERN_ERR PFX "No memory for ib_mad_port_private\n");
        return -ENOMEM;
    }

    port_priv->device = device;
    port_priv->port_num = port_num;
    spin_lock_init(&port_priv->reg_lock);
    INIT_LIST_HEAD(&port_priv->agent_list);
    init_mad_qp(port_priv, &port_priv->qp_info[0]);
    init_mad_qp(port_priv, &port_priv->qp_info[1]);

    cq_size = mad_sendq_size + mad_recvq_size;
    has_smi = rdma_port_get_link_layer(device, port_num) == IB_LINK_LAYER_INFINIBAND;
    if (has_smi)
        cq_size *= 2;

    port_priv->cq = ib_create_cq(port_priv->device,
                     ib_mad_thread_completion_handler,
                     NULL, port_priv, cq_size, 0);
    if (IS_ERR(port_priv->cq)) {
        printk(KERN_ERR PFX "Couldn't create ib_mad CQ\n");
        ret = PTR_ERR(port_priv->cq);
        goto error3;
    }

    port_priv->pd = ib_alloc_pd(device);
    if (IS_ERR(port_priv->pd)) {
        printk(KERN_ERR PFX "Couldn't create ib_mad PD\n");
        ret = PTR_ERR(port_priv->pd);
        goto error4;
    }

    port_priv->mr = ib_get_dma_mr(port_priv->pd, IB_ACCESS_LOCAL_WRITE);
    if (IS_ERR(port_priv->mr)) {
        printk(KERN_ERR PFX "Couldn't get ib_mad DMA MR\n");
        ret = PTR_ERR(port_priv->mr);
        goto error5;
    }

    if (has_smi) {
        ret = create_mad_qp(&port_priv->qp_info[0], IB_QPT_SMI);
        if (ret)
            goto error6;
    }
    ret = create_mad_qp(&port_priv->qp_info[1], IB_QPT_GSI);
    if (ret)
        goto error7;

    snprintf(name, sizeof name, "ib_mad%d", port_num);
    port_priv->wq = create_singlethread_workqueue(name);
    if (!port_priv->wq) {
        ret = -ENOMEM;
        goto error8;
    }
    INIT_WORK(&port_priv->work, ib_mad_completion_handler);

    spin_lock_irqsave(&ib_mad_port_list_lock, flags);
    list_add_tail(&port_priv->port_list, &ib_mad_port_list);
    spin_unlock_irqrestore(&ib_mad_port_list_lock, flags);

    ret = ib_mad_port_start(port_priv);
    if (ret) {
        printk(KERN_ERR PFX "Couldn't start port\n");
        goto error9;
    }

    return 0;

error9:
    spin_lock_irqsave(&ib_mad_port_list_lock, flags);
    list_del_init(&port_priv->port_list);
    spin_unlock_irqrestore(&ib_mad_port_list_lock, flags);

    destroy_workqueue(port_priv->wq);
error8:
    destroy_mad_qp(&port_priv->qp_info[1]);
error7:
    destroy_mad_qp(&port_priv->qp_info[0]);
error6:
    ib_dereg_mr(port_priv->mr);
error5:
    ib_dealloc_pd(port_priv->pd);
error4:
    ib_destroy_cq(port_priv->cq);
    cleanup_recv_queue(&port_priv->qp_info[1]);
    cleanup_recv_queue(&port_priv->qp_info[0]);
error3:
    kfree(port_priv);

    return ret;
}

/*
 * Close the port
 * If there are no classes using the port, free the port
 * resources (CQ, MR, PD, QP) and remove the port's info structure
 */
static int ib_mad_port_close(struct ib_device *device, int port_num)
{
    struct ib_mad_port_private *port_priv;
    unsigned long flags;

    spin_lock_irqsave(&ib_mad_port_list_lock, flags);
    port_priv = __ib_get_mad_port(device, port_num);
    if (port_priv == NULL) {
        spin_unlock_irqrestore(&ib_mad_port_list_lock, flags);
        printk(KERN_ERR PFX "Port %d not found\n", port_num);
        return -ENODEV;
    }
    list_del_init(&port_priv->port_list);
    spin_unlock_irqrestore(&ib_mad_port_list_lock, flags);

    destroy_workqueue(port_priv->wq);
    destroy_mad_qp(&port_priv->qp_info[1]);
    destroy_mad_qp(&port_priv->qp_info[0]);
    ib_dereg_mr(port_priv->mr);
    ib_dealloc_pd(port_priv->pd);
    ib_destroy_cq(port_priv->cq);
    cleanup_recv_queue(&port_priv->qp_info[1]);
    cleanup_recv_queue(&port_priv->qp_info[0]);
    /* XXX: Handle deallocation of MAD registration tables */

    kfree(port_priv);

    return 0;
}

static void ib_mad_init_device(struct ib_device *device)
{
    int start, end, i;

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

    if (device->node_type == RDMA_NODE_IB_SWITCH) {
        start = 0;
        end   = 0;
    } else {
        start = 1;
        end   = device->phys_port_cnt;
    }

    for (i = start; i <= end; i++) {
        if (ib_mad_port_open(device, i)) {
            printk(KERN_ERR PFX "Couldn't open %s port %d\n",
                   device->name, i);
            goto error;
        }
        if (ib_agent_port_open(device, i)) {
            printk(KERN_ERR PFX "Couldn't open %s port %d "
                   "for agents\n",
                   device->name, i);
            goto error_agent;
        }
    }
    return;

error_agent:
    if (ib_mad_port_close(device, i))
        printk(KERN_ERR PFX "Couldn't close %s port %d\n",
               device->name, i);

error:
    i--;

    while (i >= start) {
        if (ib_agent_port_close(device, i))
            printk(KERN_ERR PFX "Couldn't close %s port %d "
                   "for agents\n",
                   device->name, i);
        if (ib_mad_port_close(device, i))
            printk(KERN_ERR PFX "Couldn't close %s port %d\n",
                   device->name, i);
        i--;
    }
}

static void ib_mad_remove_device(struct ib_device *device)
{
    int i, num_ports, cur_port;

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

    if (device->node_type == RDMA_NODE_IB_SWITCH) {
        num_ports = 1;
        cur_port = 0;
    } else {
        num_ports = device->phys_port_cnt;
        cur_port = 1;
    }
    for (i = 0; i < num_ports; i++, cur_port++) {
        if (ib_agent_port_close(device, cur_port))
            printk(KERN_ERR PFX "Couldn't close %s port %d "
                   "for agents\n",
                   device->name, cur_port);
        if (ib_mad_port_close(device, cur_port))
            printk(KERN_ERR PFX "Couldn't close %s port %d\n",
                   device->name, cur_port);
    }
}

static struct ib_client mad_client = {
    .name   = "mad",
    .add = ib_mad_init_device,
    .remove = ib_mad_remove_device
};

static int __init ib_mad_init_module(void)
{
    int ret;

    mad_recvq_size = min(mad_recvq_size, IB_MAD_QP_MAX_SIZE);
    mad_recvq_size = max(mad_recvq_size, IB_MAD_QP_MIN_SIZE);

    mad_sendq_size = min(mad_sendq_size, IB_MAD_QP_MAX_SIZE);
    mad_sendq_size = max(mad_sendq_size, IB_MAD_QP_MIN_SIZE);

    ib_mad_cache = kmem_cache_create("ib_mad",
                     sizeof(struct ib_mad_private),
                     0,
                     SLAB_HWCACHE_ALIGN,
                     NULL);
    if (!ib_mad_cache) {
        printk(KERN_ERR PFX "Couldn't create ib_mad cache\n");
        ret = -ENOMEM;
        goto error1;
    }

    INIT_LIST_HEAD(&ib_mad_port_list);

    if (ib_register_client(&mad_client)) {
        printk(KERN_ERR PFX "Couldn't register ib_mad client\n");
        ret = -EINVAL;
        goto error2;
    }

    return 0;

error2:
    kmem_cache_destroy(ib_mad_cache);
error1:
    return ret;
}

static void __exit ib_mad_cleanup_module(void)
{
    ib_unregister_client(&mad_client);
    kmem_cache_destroy(ib_mad_cache);
}

module_init(ib_mad_init_module);
module_exit(ib_mad_cleanup_module);