/*
 * 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.
 * Copyright (c) 2014 Intel Corporation.  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.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 "opa_smi.h"
#include "agent.h"
#include "core_priv.h"

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 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,
                                        const struct ib_mad_hdr *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);
static bool ib_mad_send_error(struct ib_mad_port_private *port_priv,
                              struct ib_wc *wc);
static void ib_mad_send_done(struct ib_cq *cq, struct ib_wc *wc);

/*
 * 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(const struct ib_mad_hdr *hdr)
{
        return ((hdr->method & IB_MGMT_METHOD_RESP) ||
                (hdr->method == IB_MGMT_METHOD_TRAP_REPRESS) ||
                ((hdr->mgmt_class == IB_MGMT_CLASS_BM) &&
                 (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,
                                           u32 registration_flags)
{
        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) {
                dev_notice(&device->dev,
                           "ib_register_mad_agent: invalid QP Type %d\n",
                           qp_type);
                goto error1;
        }

        if (rmpp_version && rmpp_version != IB_MGMT_RMPP_VERSION) {
                dev_notice(&device->dev,
                           "ib_register_mad_agent: invalid RMPP Version %u\n",
                           rmpp_version);
                goto error1;
        }

        /* Validate MAD registration request if supplied */
        if (mad_reg_req) {
                if (mad_reg_req->mgmt_class_version >= MAX_MGMT_VERSION) {
                        dev_notice(&device->dev,
                                   "ib_register_mad_agent: invalid Class Version %u\n",
                                   mad_reg_req->mgmt_class_version);
                        goto error1;
                }
                if (!recv_handler) {
                        dev_notice(&device->dev,
                                   "ib_register_mad_agent: no recv_handler\n");
                        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) {
                                dev_notice(&device->dev,
                                           "ib_register_mad_agent: Invalid Mgmt Class 0x%x\n",
                                           mad_reg_req->mgmt_class);
                                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
                         */
                        dev_notice(&device->dev,
                                   "ib_register_mad_agent: Invalid Mgmt Class 0\n");
                        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)) {
                                dev_notice(&device->dev,
                                           "ib_register_mad_agent: No OUI specified for class 0x%x\n",
                                           mad_reg_req->mgmt_class);
                                goto error1;
                        }
                }
                /* Make sure class supplied is consistent with RMPP */
                if (!ib_is_mad_class_rmpp(mad_reg_req->mgmt_class)) {
                        if (rmpp_version) {
                                dev_notice(&device->dev,
                                           "ib_register_mad_agent: RMPP version for non-RMPP class 0x%x\n",
                                           mad_reg_req->mgmt_class);
                                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)) {
                                dev_notice(&device->dev,
                                           "ib_register_mad_agent: Invalid SM QP type: class 0x%x\n",
                                           mad_reg_req->mgmt_class);
                                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)) {
                                dev_notice(&device->dev,
                                           "ib_register_mad_agent: Invalid GS QP type: class 0x%x\n",
                                           mad_reg_req->mgmt_class);
                                goto error1;
                        }
                }
        } else {
                /* No registration request supplied */
                if (!send_handler)
                        goto error1;
                if (registration_flags & IB_MAD_USER_RMPP)
                        goto error1;
        }

        /* Validate device and port */
        port_priv = ib_get_mad_port(device, port_num);
        if (!port_priv) {
                dev_notice(&device->dev, "ib_register_mad_agent: Invalid port\n");
                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) {
                dev_notice(&device->dev,
                           "ib_register_mad_agent: QP %d not supported\n", qpn);
                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;
        }

        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;
        mad_agent_priv->agent.flags = registration_flags;
        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:
        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);
        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, NULL,
                                                   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, struct ib_cqe *cqe, u16 slid,
                u16 pkey_index, u8 port_num, struct ib_wc *wc)
{
        memset(wc, 0, sizeof *wc);
        wc->wr_cqe = cqe;
        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;
}

static size_t mad_priv_size(const struct ib_mad_private *mp)
{
        return sizeof(struct ib_mad_private) + mp->mad_size;
}

static struct ib_mad_private *alloc_mad_private(size_t mad_size, gfp_t flags)
{
        size_t size = sizeof(struct ib_mad_private) + mad_size;
        struct ib_mad_private *ret = kzalloc(size, flags);

        if (ret)
                ret->mad_size = mad_size;

        return ret;
}

static size_t port_mad_size(const struct ib_mad_port_private *port_priv)
{
        return rdma_max_mad_size(port_priv->device, port_priv->port_num);
}

static size_t mad_priv_dma_size(const struct ib_mad_private *mp)
{
        return sizeof(struct ib_grh) + mp->mad_size;
}

/*
 * 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;
        struct opa_smp *opa_smp = (struct opa_smp *)smp;
        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_ud_wr *send_wr = &mad_send_wr->send_wr;
        size_t mad_size = port_mad_size(mad_agent_priv->qp_info->port_priv);
        u16 out_mad_pkey_index = 0;
        u16 drslid;
        bool opa = rdma_cap_opa_mad(mad_agent_priv->qp_info->port_priv->device,
                                    mad_agent_priv->qp_info->port_priv->port_num);

        if (rdma_cap_ib_switch(device) &&
            smp->mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
                port_num = send_wr->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 (opa && smp->class_version == OPA_SMP_CLASS_VERSION) {
                u32 opa_drslid;

                if ((opa_get_smp_direction(opa_smp)
                     ? opa_smp->route.dr.dr_dlid : opa_smp->route.dr.dr_slid) ==
                     OPA_LID_PERMISSIVE &&
                     opa_smi_handle_dr_smp_send(opa_smp,
                                                rdma_cap_ib_switch(device),
                                                port_num) == IB_SMI_DISCARD) {
                        ret = -EINVAL;
                        dev_err(&device->dev, "OPA Invalid directed route\n");
                        goto out;
                }
                opa_drslid = be32_to_cpu(opa_smp->route.dr.dr_slid);
                if (opa_drslid != be32_to_cpu(OPA_LID_PERMISSIVE) &&
                    opa_drslid & 0xffff0000) {
                        ret = -EINVAL;
                        dev_err(&device->dev, "OPA Invalid dr_slid 0x%x\n",
                               opa_drslid);
                        goto out;
                }
                drslid = (u16)(opa_drslid & 0x0000ffff);

                /* Check to post send on QP or process locally */
                if (opa_smi_check_local_smp(opa_smp, device) == IB_SMI_DISCARD &&
                    opa_smi_check_local_returning_smp(opa_smp, device) == IB_SMI_DISCARD)
                        goto out;
        } else {
                if ((ib_get_smp_direction(smp) ? smp->dr_dlid : smp->dr_slid) ==
                     IB_LID_PERMISSIVE &&
                     smi_handle_dr_smp_send(smp, rdma_cap_ib_switch(device), port_num) ==
                     IB_SMI_DISCARD) {
                        ret = -EINVAL;
                        dev_err(&device->dev, "Invalid directed route\n");
                        goto out;
                }
                drslid = be16_to_cpu(smp->dr_slid);

                /* 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;
                dev_err(&device->dev, "No memory for ib_mad_local_private\n");
                goto out;
        }
        local->mad_priv = NULL;
        local->recv_mad_agent = NULL;
        mad_priv = alloc_mad_private(mad_size, GFP_ATOMIC);
        if (!mad_priv) {
                ret = -ENOMEM;
                dev_err(&device->dev, "No memory for local response MAD\n");
                kfree(local);
                goto out;
        }

        build_smp_wc(mad_agent_priv->agent.qp,
                     send_wr->wr.wr_cqe, drslid,
                     send_wr->pkey_index,
                     send_wr->port_num, &mad_wc);

        if (opa && smp->base_version == OPA_MGMT_BASE_VERSION) {
                mad_wc.byte_len = mad_send_wr->send_buf.hdr_len
                                        + mad_send_wr->send_buf.data_len
                                        + sizeof(struct ib_grh);
        }

        /* No GRH for DR SMP */
        ret = device->process_mad(device, 0, port_num, &mad_wc, NULL,
                                  (const struct ib_mad_hdr *)smp, mad_size,
                                  (struct ib_mad_hdr *)mad_priv->mad,
                                  &mad_size, &out_mad_pkey_index);
        switch (ret)
        {
        case IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY:
                if (ib_response_mad((const struct ib_mad_hdr *)mad_priv->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
                        kfree(mad_priv);
                break;
        case IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED:
                kfree(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, smp, mad_priv->mad_size);
                        recv_mad_agent = find_mad_agent(port_priv,
                                                        (const struct ib_mad_hdr *)mad_priv->mad);
                }
                if (!port_priv || !recv_mad_agent) {
                        /*
                         * No receiving agent so drop packet and
                         * generate send completion.
                         */
                        kfree(mad_priv);
                        break;
                }
                local->mad_priv = mad_priv;
                local->recv_mad_agent = recv_mad_agent;
                break;
        default:
                kfree(mad_priv);
                kfree(local);
                ret = -EINVAL;
                goto out;
        }

        local->mad_send_wr = mad_send_wr;
        if (opa) {
                local->mad_send_wr->send_wr.pkey_index = out_mad_pkey_index;
                local->return_wc_byte_len = mad_size;
        }
        /* 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, size_t mad_size)
{
        int seg_size, pad;

        seg_size = mad_size - 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,
                                size_t mad_size, 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 = mad_size - send_buf->hdr_len;
        send_buf->seg_rmpp_size = mad_size - IB_MGMT_RMPP_HDR;
        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) {
                        dev_err(&send_buf->mad_agent->device->dev,
                                "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;
}

int ib_mad_kernel_rmpp_agent(const struct ib_mad_agent *agent)
{
        return agent->rmpp_version && !(agent->flags & IB_MAD_USER_RMPP);
}
EXPORT_SYMBOL(ib_mad_kernel_rmpp_agent);

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,
                                            u8 base_version)
{
        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;
        size_t mad_size;
        bool opa;

        mad_agent_priv = container_of(mad_agent, struct ib_mad_agent_private,
                                      agent);

        opa = rdma_cap_opa_mad(mad_agent->device, mad_agent->port_num);

        if (opa && base_version == OPA_MGMT_BASE_VERSION)

                mad_size = sizeof(struct opa_mad);
        else
                mad_size = sizeof(struct ib_mad);

        pad = get_pad_size(hdr_len, data_len, mad_size);
        message_size = hdr_len + data_len + pad;

        if (ib_mad_kernel_rmpp_agent(mad_agent)) {
                if (!rmpp_active && message_size > mad_size)
                        return ERR_PTR(-EINVAL);
        } else
                if (rmpp_active || message_size > mad_size)
                        return ERR_PTR(-EINVAL);

        size = rmpp_active ? hdr_len : mad_size;
        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->qp->pd->local_dma_lkey;

        /* OPA MADs don't have to be the full 2048 bytes */
        if (opa && base_version == OPA_MGMT_BASE_VERSION &&
            data_len < mad_size - hdr_len)
                mad_send_wr->sg_list[1].length = data_len;
        else
                mad_send_wr->sg_list[1].length = mad_size - hdr_len;

        mad_send_wr->sg_list[1].lkey = mad_agent->qp->pd->local_dma_lkey;

        mad_send_wr->mad_list.cqe.done = ib_mad_send_done;

        mad_send_wr->send_wr.wr.wr_cqe = &mad_send_wr->mad_list.cqe;
        mad_send_wr->send_wr.wr.sg_list = mad_send_wr->sg_list;
        mad_send_wr->send_wr.wr.num_sge = 2;
        mad_send_wr->send_wr.wr.opcode = IB_WR_SEND;
        mad_send_wr->send_wr.wr.send_flags = IB_SEND_SIGNALED;
        mad_send_wr->send_wr.remote_qpn = remote_qpn;
        mad_send_wr->send_wr.remote_qkey = IB_QP_SET_QKEY;
        mad_send_wr->send_wr.pkey_index = pkey_index;

        if (rmpp_active) {
                ret = alloc_send_rmpp_list(mad_send_wr, mad_size, 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->mad_list.mad_queue = &qp_info->send_queue;
        mad_send_wr->mad_list.cqe.done = ib_mad_send_done;
        mad_send_wr->send_wr.wr.wr_cqe = &mad_send_wr->mad_list.cqe;

        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);
        if (unlikely(ib_dma_mapping_error(mad_agent->device, sge[0].addr)))
                return -ENOMEM;

        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);
        if (unlikely(ib_dma_mapping_error(mad_agent->device, sge[1].addr))) {
                ib_dma_unmap_single(mad_agent->device,
                                    mad_send_wr->header_mapping,
                                    sge[0].length, DMA_TO_DEVICE);
                return -ENOMEM;
        }
        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.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.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 (ib_mad_kernel_rmpp_agent(&mad_agent_priv->agent)) {
                        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);
                kfree(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)
{
        dev_err(&mad_agent->device->dev,
                "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]) {
                        pr_err("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) {
                pr_err("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,
                           const 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) {
                        dev_err(&agent_priv->agent.device->dev,
                                "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) {
                        dev_err(&agent_priv->agent.device->dev,
                                "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) {
                        dev_err(&agent_priv->agent.device->dev,
                                "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;
                }
        }
        dev_err(&agent_priv->agent.device->dev, "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,
               const struct ib_mad_hdr *mad_hdr)
{
        struct ib_mad_agent_private *mad_agent = NULL;
        unsigned long flags;

        spin_lock_irqsave(&port_priv->reg_lock, flags);
        if (ib_response_mad(mad_hdr)) {
                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_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;
                const 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_hdr->class_version >= MAX_MGMT_VERSION)
                        goto out;
                if (!is_vendor_class(mad_hdr->mgmt_class)) {
                        class = port_priv->version[
                                        mad_hdr->class_version].class;
                        if (!class)
                                goto out;
                        if (convert_mgmt_class(mad_hdr->mgmt_class) >=
                            IB_MGMT_MAX_METHODS)
                                goto out;
                        method = class->method_table[convert_mgmt_class(
                                                        mad_hdr->mgmt_class)];
                        if (method)
                                mad_agent = method->agent[mad_hdr->method &
                                                          ~IB_MGMT_METHOD_RESP];
                } else {
                        vendor = port_priv->version[
                                        mad_hdr->class_version].vendor;
                        if (!vendor)
                                goto out;
                        vendor_class = vendor->vendor_class[vendor_class_index(
                                                mad_hdr->mgmt_class)];
                        if (!vendor_class)
                                goto out;
                        /* Find matching OUI */
                        vendor_mad = (const struct ib_vendor_mad *)mad_hdr;
                        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_hdr->method &
                                                          ~IB_MGMT_METHOD_RESP];
                        }
                }
        }

        if (mad_agent) {
                if (mad_agent->agent.recv_handler)
                        atomic_inc(&mad_agent->refcount);
                else {
                        dev_notice(&port_priv->device->dev,
                                   "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(const struct ib_mad_hdr *mad_hdr,
                        const struct ib_mad_qp_info *qp_info,
                        bool opa)
{
        int valid = 0;
        u32 qp_num = qp_info->qp->qp_num;

        /* Make sure MAD base version is understood */
        if (mad_hdr->base_version != IB_MGMT_BASE_VERSION &&
            (!opa || mad_hdr->base_version != OPA_MGMT_BASE_VERSION)) {
                pr_err("MAD received with unsupported base version %d %s\n",
                       mad_hdr->base_version, opa ? "(opa)" : "");
                goto out;
        }

        /* Filter SMI packets sent to other than QP0 */
        if ((mad_hdr->mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED) ||
            (mad_hdr->mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)) {
                if (qp_num == 0)
                        valid = 1;
        } else {
                /* CM attributes other than ClassPortInfo only use Send method */
                if ((mad_hdr->mgmt_class == IB_MGMT_CLASS_CM) &&
                    (mad_hdr->attr_id != IB_MGMT_CLASSPORTINFO_ATTR_ID) &&
                    (mad_hdr->method != IB_MGMT_METHOD_SEND))
                        goto out;
                /* Filter GSI packets sent to QP0 */
                if (qp_num != 0)
                        valid = 1;
        }

out:
        return valid;
}

static int is_rmpp_data_mad(const struct ib_mad_agent_private *mad_agent_priv,
                            const 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_mad_kernel_rmpp_agent(&mad_agent_priv->agent) ||
                !(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(const struct ib_mad_send_wr_private *wr,
                                     const struct ib_mad_recv_wc *rwc)
{
        return ((struct ib_mad_hdr *)(wr->send_buf.mad))->mgmt_class ==
                rwc->recv_buf.mad->mad_hdr.mgmt_class;
}

static inline int rcv_has_same_gid(const struct ib_mad_agent_private *mad_agent_priv,
                                   const struct ib_mad_send_wr_private *wr,
                                   const 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_hdr *)wr->send_buf.mad);
        rcv_resp = ib_response_mad(&rwc->recv_buf.mad->mad_hdr);

        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, NULL))
                                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(const struct ib_mad_agent_private *mad_agent_priv,
                 const struct ib_mad_recv_wc *wc)
{
        struct ib_mad_send_wr_private *wr;
        const struct ib_mad_hdr *mad_hdr;

        mad_hdr = &wc->recv_buf.mad->mad_hdr;

        list_for_each_entry(wr, &mad_agent_priv->wait_list, agent_list) {
                if ((wr->tid == mad_hdr->tid) &&
                    rcv_has_same_class(wr, wc) &&
                    /*
                     * Don't check GID for direct routed MADs.
                     * These might have permissive LIDs.
                     */
                    (is_direct(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_rmpp_data_mad(mad_agent_priv, wr->send_buf.mad) &&
                    wr->tid == 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(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 (ib_mad_kernel_rmpp_agent(&mad_agent_priv->agent)) {
                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->mad_hdr)) {
                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);
                        if (!ib_mad_kernel_rmpp_agent(&mad_agent_priv->agent)
                           && ib_is_mad_class_rmpp(mad_recv_wc->recv_buf.mad->mad_hdr.mgmt_class)
                           && (ib_get_rmpp_flags(&((struct ib_rmpp_mad *)mad_recv_wc->recv_buf.mad)->rmpp_hdr)
                                        & IB_MGMT_RMPP_FLAG_ACTIVE)) {
                                /* user rmpp is in effect
                                 * and this is an active RMPP MAD
                                 */
                                mad_agent_priv->agent.recv_handler(
                                                &mad_agent_priv->agent, NULL,
                                                mad_recv_wc);
                                atomic_dec(&mad_agent_priv->refcount);
                        } else {
                                /* not user rmpp, revert to normal behavior and
                                 * drop the mad */
                                ib_free_recv_mad(mad_recv_wc);
                                deref_mad_agent(mad_agent_priv);
                                return;
                        }
                } else {
                        ib_mark_mad_done(mad_send_wr);
                        spin_unlock_irqrestore(&mad_agent_priv->lock, flags);

                        /* Defined behavior is to complete response before request */
                        mad_agent_priv->agent.recv_handler(
                                        &mad_agent_priv->agent,
                                        &mad_send_wr->send_buf,
                                        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, NULL,
                                                   mad_recv_wc);
                deref_mad_agent(mad_agent_priv);
        }
}

static enum smi_action handle_ib_smi(const struct ib_mad_port_private *port_priv,
                                     const struct ib_mad_qp_info *qp_info,
                                     const struct ib_wc *wc,
                                     int port_num,
                                     struct ib_mad_private *recv,
                                     struct ib_mad_private *response)
{
        enum smi_forward_action retsmi;
        struct ib_smp *smp = (struct ib_smp *)recv->mad;

        if (smi_handle_dr_smp_recv(smp,
                                   rdma_cap_ib_switch(port_priv->device),
                                   port_num,
                                   port_priv->device->phys_port_cnt) ==
                                   IB_SMI_DISCARD)
                return IB_SMI_DISCARD;

        retsmi = smi_check_forward_dr_smp(smp);
        if (retsmi == IB_SMI_LOCAL)
                return IB_SMI_HANDLE;

        if (retsmi == IB_SMI_SEND) { /* don't forward */
                if (smi_handle_dr_smp_send(smp,
                                           rdma_cap_ib_switch(port_priv->device),
                                           port_num) == IB_SMI_DISCARD)
                        return IB_SMI_DISCARD;

                if (smi_check_local_smp(smp, port_priv->device) == IB_SMI_DISCARD)
                        return IB_SMI_DISCARD;
        } else if (rdma_cap_ib_switch(port_priv->device)) {
                /* forward case for switches */
                memcpy(response, recv, mad_priv_size(response));
                response->header.recv_wc.wc = &response->header.wc;
                response->header.recv_wc.recv_buf.mad = (struct ib_mad *)response->mad;
                response->header.recv_wc.recv_buf.grh = &response->grh;

                agent_send_response((const struct ib_mad_hdr *)response->mad,
                                    &response->grh, wc,
                                    port_priv->device,
                                    smi_get_fwd_port(smp),
                                    qp_info->qp->qp_num,
                                    response->mad_size,
                                    false);

                return IB_SMI_DISCARD;
        }
        return IB_SMI_HANDLE;
}

static bool generate_unmatched_resp(const struct ib_mad_private *recv,
                                    struct ib_mad_private *response,
                                    size_t *resp_len, bool opa)
{
        const struct ib_mad_hdr *recv_hdr = (const struct ib_mad_hdr *)recv->mad;
        struct ib_mad_hdr *resp_hdr = (struct ib_mad_hdr *)response->mad;

        if (recv_hdr->method == IB_MGMT_METHOD_GET ||
            recv_hdr->method == IB_MGMT_METHOD_SET) {
                memcpy(response, recv, mad_priv_size(response));
                response->header.recv_wc.wc = &response->header.wc;
                response->header.recv_wc.recv_buf.mad = (struct ib_mad *)response->mad;
                response->header.recv_wc.recv_buf.grh = &response->grh;
                resp_hdr->method = IB_MGMT_METHOD_GET_RESP;
                resp_hdr->status = cpu_to_be16(IB_MGMT_MAD_STATUS_UNSUPPORTED_METHOD_ATTRIB);
                if (recv_hdr->mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
                        resp_hdr->status |= IB_SMP_DIRECTION;

                if (opa && recv_hdr->base_version == OPA_MGMT_BASE_VERSION) {
                        if (recv_hdr->mgmt_class ==
                            IB_MGMT_CLASS_SUBN_LID_ROUTED ||
                            recv_hdr->mgmt_class ==
                            IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
                                *resp_len = opa_get_smp_header_size(
                                                        (struct opa_smp *)recv->mad);
                        else
                                *resp_len = sizeof(struct ib_mad_hdr);
                }

                return true;
        } else {
                return false;
        }
}

static enum smi_action
handle_opa_smi(struct ib_mad_port_private *port_priv,
               struct ib_mad_qp_info *qp_info,
               struct ib_wc *wc,
               int port_num,
               struct ib_mad_private *recv,
               struct ib_mad_private *response)
{
        enum smi_forward_action retsmi;
        struct opa_smp *smp = (struct opa_smp *)recv->mad;

        if (opa_smi_handle_dr_smp_recv(smp,
                                   rdma_cap_ib_switch(port_priv->device),
                                   port_num,
                                   port_priv->device->phys_port_cnt) ==
                                   IB_SMI_DISCARD)
                return IB_SMI_DISCARD;

        retsmi = opa_smi_check_forward_dr_smp(smp);
        if (retsmi == IB_SMI_LOCAL)
                return IB_SMI_HANDLE;

        if (retsmi == IB_SMI_SEND) { /* don't forward */
                if (opa_smi_handle_dr_smp_send(smp,
                                           rdma_cap_ib_switch(port_priv->device),
                                           port_num) == IB_SMI_DISCARD)
                        return IB_SMI_DISCARD;

                if (opa_smi_check_local_smp(smp, port_priv->device) ==
                    IB_SMI_DISCARD)
                        return IB_SMI_DISCARD;

        } else if (rdma_cap_ib_switch(port_priv->device)) {
                /* forward case for switches */
                memcpy(response, recv, mad_priv_size(response));
                response->header.recv_wc.wc = &response->header.wc;
                response->header.recv_wc.recv_buf.opa_mad =
                                (struct opa_mad *)response->mad;
                response->header.recv_wc.recv_buf.grh = &response->grh;

                agent_send_response((const struct ib_mad_hdr *)response->mad,
                                    &response->grh, wc,
                                    port_priv->device,
                                    opa_smi_get_fwd_port(smp),
                                    qp_info->qp->qp_num,
                                    recv->header.wc.byte_len,
                                    true);

                return IB_SMI_DISCARD;
        }

        return IB_SMI_HANDLE;
}

static enum smi_action
handle_smi(struct ib_mad_port_private *port_priv,
           struct ib_mad_qp_info *qp_info,
           struct ib_wc *wc,
           int port_num,
           struct ib_mad_private *recv,
           struct ib_mad_private *response,
           bool opa)
{
        struct ib_mad_hdr *mad_hdr = (struct ib_mad_hdr *)recv->mad;

        if (opa && mad_hdr->base_version == OPA_MGMT_BASE_VERSION &&
            mad_hdr->class_version == OPA_SMI_CLASS_VERSION)
                return handle_opa_smi(port_priv, qp_info, wc, port_num, recv,
                                      response);

        return handle_ib_smi(port_priv, qp_info, wc, port_num, recv, response);
}

static void ib_mad_recv_done(struct ib_cq *cq, struct ib_wc *wc)
{
        struct ib_mad_port_private *port_priv = cq->cq_context;
        struct ib_mad_list_head *mad_list =
                container_of(wc->wr_cqe, struct ib_mad_list_head, cqe);
        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_agent_private *mad_agent;
        int port_num;
        int ret = IB_MAD_RESULT_SUCCESS;
        size_t mad_size;
        u16 resp_mad_pkey_index = 0;
        bool opa;

        if (list_empty_careful(&port_priv->port_list))
                return;

        if (wc->status != IB_WC_SUCCESS) {
                /*
                 * Receive errors indicate that the QP has entered the error
                 * state - error handling/shutdown code will cleanup
                 */
                return;
        }

        qp_info = mad_list->mad_queue->qp_info;
        dequeue_mad(mad_list);

        opa = rdma_cap_opa_mad(qp_info->port_priv->device,
                               qp_info->port_priv->port_num);

        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,
                            mad_priv_dma_size(recv),
                            DMA_FROM_DEVICE);

        /* Setup MAD receive work completion from "normal" work completion */
        recv->header.wc = *wc;
        recv->header.recv_wc.wc = &recv->header.wc;

        if (opa && ((struct ib_mad_hdr *)(recv->mad))->base_version == OPA_MGMT_BASE_VERSION) {
                recv->header.recv_wc.mad_len = wc->byte_len - sizeof(struct ib_grh);
                recv->header.recv_wc.mad_seg_size = sizeof(struct opa_mad);
        } else {
                recv->header.recv_wc.mad_len = sizeof(struct ib_mad);
                recv->header.recv_wc.mad_seg_size = sizeof(struct ib_mad);
        }

        recv->header.recv_wc.recv_buf.mad = (struct ib_mad *)recv->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((const struct ib_mad_hdr *)recv->mad, qp_info, opa))
                goto out;

        mad_size = recv->mad_size;
        response = alloc_mad_private(mad_size, GFP_KERNEL);
        if (!response) {
                dev_err(&port_priv->device->dev,
                        "%s: no memory for response buffer\n", __func__);
                goto out;
        }

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

        if (((struct ib_mad_hdr *)recv->mad)->mgmt_class ==
            IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
                if (handle_smi(port_priv, qp_info, wc, port_num, recv,
                               response, opa)
                    == IB_SMI_DISCARD)
                        goto out;
        }

        /* 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,
                                                     (const struct ib_mad_hdr *)recv->mad,
                                                     recv->mad_size,
                                                     (struct ib_mad_hdr *)response->mad,
                                                     &mad_size, &resp_mad_pkey_index);

                if (opa)
                        wc->pkey_index = resp_mad_pkey_index;

                if (ret & IB_MAD_RESULT_SUCCESS) {
                        if (ret & IB_MAD_RESULT_CONSUMED)
                                goto out;
                        if (ret & IB_MAD_RESULT_REPLY) {
                                agent_send_response((const struct ib_mad_hdr *)response->mad,
                                                    &recv->grh, wc,
                                                    port_priv->device,
                                                    port_num,
                                                    qp_info->qp->qp_num,
                                                    mad_size, opa);
                                goto out;
                        }
                }
        }

        mad_agent = find_mad_agent(port_priv, (const struct ib_mad_hdr *)recv->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, &mad_size, opa)) {
                agent_send_response((const struct ib_mad_hdr *)response->mad, &recv->grh, wc,
                                    port_priv->device, port_num,
                                    qp_info->qp->qp_num, mad_size, opa);
        }

out:
        /* Post another receive request for this QP */
        if (response) {
                ib_mad_post_receive_mads(qp_info, response);
                kfree(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 (ib_mad_kernel_rmpp_agent(&mad_agent_priv->agent)) {
                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(struct ib_cq *cq, struct ib_wc *wc)
{
        struct ib_mad_port_private *port_priv = cq->cq_context;
        struct ib_mad_list_head *mad_list =
                container_of(wc->wr_cqe, struct ib_mad_list_head, cqe);
        struct ib_mad_send_wr_private   *mad_send_wr, *queued_send_wr;
        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;

        if (list_empty_careful(&port_priv->port_list))
                return;

        if (wc->status != IB_WC_SUCCESS) {
                if (!ib_mad_send_error(port_priv, wc))
                        return;
        }

        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.wr,
                                   &bad_send_wr);
                if (ret) {
                        dev_err(&port_priv->device->dev,
                                "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 bool ib_mad_send_error(struct ib_mad_port_private *port_priv,
                struct ib_wc *wc)
{
        struct ib_mad_list_head *mad_list =
                container_of(wc->wr_cqe, struct ib_mad_list_head, cqe);
        struct ib_mad_qp_info *qp_info = mad_list->mad_queue->qp_info;
        struct ib_mad_send_wr_private *mad_send_wr;
        int ret;

        /*
         * 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.wr,
                                        &bad_send_wr);
                        if (!ret)
                                return false;
                }
        } 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)
                                dev_err(&port_priv->device->dev,
                                        "%s - ib_modify_qp to RTS: %d\n",
                                        __func__, ret);
                        else
                                mark_sends_for_retry(qp_info);
                }
        }

        return true;
}

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_rmpp_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;
        bool opa;

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

        opa = rdma_cap_opa_mad(mad_agent_priv->qp_info->port_priv->device,
                               mad_agent_priv->qp_info->port_priv->port_num);

        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) {
                        u8 base_version;
                        recv_mad_agent = local->recv_mad_agent;
                        if (!recv_mad_agent) {
                                dev_err(&mad_agent_priv->agent.device->dev,
                                        "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,
                                     local->mad_send_wr->send_wr.wr.wr_cqe,
                                     be16_to_cpu(IB_LID_PERMISSIVE),
                                     local->mad_send_wr->send_wr.pkey_index,
                                     recv_mad_agent->agent.port_num, &wc);

                        local->mad_priv->header.recv_wc.wc = &wc;

                        base_version = ((struct ib_mad_hdr *)(local->mad_priv->mad))->base_version;
                        if (opa && base_version == OPA_MGMT_BASE_VERSION) {
                                local->mad_priv->header.recv_wc.mad_len = local->return_wc_byte_len;
                                local->mad_priv->header.recv_wc.mad_seg_size = sizeof(struct opa_mad);
                        } else {
                                local->mad_priv->header.recv_wc.mad_len = sizeof(struct ib_mad);
                                local->mad_priv->header.recv_wc.mad_seg_size = 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 =
                                                (struct ib_mad *)local->mad_priv->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_send_wr->send_buf,
                                                &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)
                        kfree(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 (ib_mad_kernel_rmpp_agent(&mad_send_wr->mad_agent_priv->agent)) {
                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);
}

/*
 * 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.lkey = qp_info->port_priv->pd->local_dma_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 = alloc_mad_private(port_mad_size(qp_info->port_priv),
                                                     GFP_ATOMIC);
                        if (!mad_priv) {
                                dev_err(&qp_info->port_priv->device->dev,
                                        "No memory for receive buffer\n");
                                ret = -ENOMEM;
                                break;
                        }
                }
                sg_list.length = mad_priv_dma_size(mad_priv);
                sg_list.addr = ib_dma_map_single(qp_info->port_priv->device,
                                                 &mad_priv->grh,
                                                 mad_priv_dma_size(mad_priv),
                                                 DMA_FROM_DEVICE);
                if (unlikely(ib_dma_mapping_error(qp_info->port_priv->device,
                                                  sg_list.addr))) {
                        ret = -ENOMEM;
                        break;
                }
                mad_priv->header.mapping = sg_list.addr;
                mad_priv->header.mad_list.mad_queue = recv_queue;
                mad_priv->header.mad_list.cqe.done = ib_mad_recv_done;
                recv_wr.wr_cqe = &mad_priv->header.mad_list.cqe;

                /* 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,
                                            mad_priv_dma_size(mad_priv),
                                            DMA_FROM_DEVICE);
                        kfree(mad_priv);
                        dev_err(&qp_info->port_priv->device->dev,
                                "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,
                                    mad_priv_dma_size(recv),
                                    DMA_FROM_DEVICE);
                kfree(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;
        u16 pkey_index;

        attr = kmalloc(sizeof *attr, GFP_KERNEL);
        if (!attr) {
                dev_err(&port_priv->device->dev,
                        "Couldn't kmalloc ib_qp_attr\n");
                return -ENOMEM;
        }

        ret = ib_find_pkey(port_priv->device, port_priv->port_num,
                           IB_DEFAULT_PKEY_FULL, &pkey_index);
        if (ret)
                pkey_index = 0;

        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 = pkey_index;
                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) {
                        dev_err(&port_priv->device->dev,
                                "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) {
                        dev_err(&port_priv->device->dev,
                                "Couldn't change QP%d state to RTR: %d\n",