mad_rmpp.c

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/*
 * Copyright (c) 2005 Intel Inc. All rights reserved.
 * Copyright (c) 2005-2006 Voltaire, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/slab.h>

#include "mad_priv.h"
#include "mad_rmpp.h"

enum rmpp_state {
    RMPP_STATE_ACTIVE,
    RMPP_STATE_TIMEOUT,
    RMPP_STATE_COMPLETE,
    RMPP_STATE_CANCELING
};

struct mad_rmpp_recv {
    struct ib_mad_agent_private *agent;
    struct list_head list;
    struct delayed_work timeout_work;
    struct delayed_work cleanup_work;
    struct completion comp;
    enum rmpp_state state;
    spinlock_t lock;
    atomic_t refcount;

    struct ib_ah *ah;
    struct ib_mad_recv_wc *rmpp_wc;
    struct ib_mad_recv_buf *cur_seg_buf;
    int last_ack;
    int seg_num;
    int newwin;
    int repwin;

    __be64 tid;
    u32 src_qp;
    u16 slid;
    u8 mgmt_class;
    u8 class_version;
    u8 method;
};

static inline void deref_rmpp_recv(struct mad_rmpp_recv *rmpp_recv)
{
    if (atomic_dec_and_test(&rmpp_recv->refcount))
        complete(&rmpp_recv->comp);
}

static void destroy_rmpp_recv(struct mad_rmpp_recv *rmpp_recv)
{
    deref_rmpp_recv(rmpp_recv);
    wait_for_completion(&rmpp_recv->comp);
    ib_destroy_ah(rmpp_recv->ah);
    kfree(rmpp_recv);
}

void ib_cancel_rmpp_recvs(struct ib_mad_agent_private *agent)
{
    struct mad_rmpp_recv *rmpp_recv, *temp_rmpp_recv;
    unsigned long flags;

    spin_lock_irqsave(&agent->lock, flags);
    list_for_each_entry(rmpp_recv, &agent->rmpp_list, list) {
        if (rmpp_recv->state != RMPP_STATE_COMPLETE)
            ib_free_recv_mad(rmpp_recv->rmpp_wc);
        rmpp_recv->state = RMPP_STATE_CANCELING;
    }
    spin_unlock_irqrestore(&agent->lock, flags);

    list_for_each_entry(rmpp_recv, &agent->rmpp_list, list) {
        cancel_delayed_work(&rmpp_recv->timeout_work);
        cancel_delayed_work(&rmpp_recv->cleanup_work);
    }

    flush_workqueue(agent->qp_info->port_priv->wq);

    list_for_each_entry_safe(rmpp_recv, temp_rmpp_recv,
                 &agent->rmpp_list, list) {
        list_del(&rmpp_recv->list);
        destroy_rmpp_recv(rmpp_recv);
    }
}

static void format_ack(struct ib_mad_send_buf *msg,
               struct ib_rmpp_mad *data,
               struct mad_rmpp_recv *rmpp_recv)
{
    struct ib_rmpp_mad *ack = msg->mad;
    unsigned long flags;

    memcpy(ack, &data->mad_hdr, msg->hdr_len);

    ack->mad_hdr.method ^= IB_MGMT_METHOD_RESP;
    ack->rmpp_hdr.rmpp_type = IB_MGMT_RMPP_TYPE_ACK;
    ib_set_rmpp_flags(&ack->rmpp_hdr, IB_MGMT_RMPP_FLAG_ACTIVE);

    spin_lock_irqsave(&rmpp_recv->lock, flags);
    rmpp_recv->last_ack = rmpp_recv->seg_num;
    ack->rmpp_hdr.seg_num = cpu_to_be32(rmpp_recv->seg_num);
    ack->rmpp_hdr.paylen_newwin = cpu_to_be32(rmpp_recv->newwin);
    spin_unlock_irqrestore(&rmpp_recv->lock, flags);
}

static void ack_recv(struct mad_rmpp_recv *rmpp_recv,
             struct ib_mad_recv_wc *recv_wc)
{
    struct ib_mad_send_buf *msg;
    int ret, hdr_len;

    hdr_len = ib_get_mad_data_offset(recv_wc->recv_buf.mad->mad_hdr.mgmt_class);
    msg = ib_create_send_mad(&rmpp_recv->agent->agent, recv_wc->wc->src_qp,
                 recv_wc->wc->pkey_index, 1, hdr_len,
                 0, GFP_KERNEL);
    if (IS_ERR(msg))
        return;

    format_ack(msg, (struct ib_rmpp_mad *) recv_wc->recv_buf.mad, rmpp_recv);
    msg->ah = rmpp_recv->ah;
    ret = ib_post_send_mad(msg, NULL);
    if (ret)
        ib_free_send_mad(msg);
}

static struct ib_mad_send_buf *alloc_response_msg(struct ib_mad_agent *agent,
                          struct ib_mad_recv_wc *recv_wc)
{
    struct ib_mad_send_buf *msg;
    struct ib_ah *ah;
    int hdr_len;

    ah = ib_create_ah_from_wc(agent->qp->pd, recv_wc->wc,
                  recv_wc->recv_buf.grh, agent->port_num);
    if (IS_ERR(ah))
        return (void *) ah;

    hdr_len = ib_get_mad_data_offset(recv_wc->recv_buf.mad->mad_hdr.mgmt_class);
    msg = ib_create_send_mad(agent, recv_wc->wc->src_qp,
                 recv_wc->wc->pkey_index, 1,
                 hdr_len, 0, GFP_KERNEL);
    if (IS_ERR(msg))
        ib_destroy_ah(ah);
    else {
        msg->ah = ah;
        msg->context[0] = ah;
    }

    return msg;
}

static void ack_ds_ack(struct ib_mad_agent_private *agent,
               struct ib_mad_recv_wc *recv_wc)
{
    struct ib_mad_send_buf *msg;
    struct ib_rmpp_mad *rmpp_mad;
    int ret;

    msg = alloc_response_msg(&agent->agent, recv_wc);
    if (IS_ERR(msg))
        return;

    rmpp_mad = msg->mad;
    memcpy(rmpp_mad, recv_wc->recv_buf.mad, msg->hdr_len);

    rmpp_mad->mad_hdr.method ^= IB_MGMT_METHOD_RESP;
    ib_set_rmpp_flags(&rmpp_mad->rmpp_hdr, IB_MGMT_RMPP_FLAG_ACTIVE);
    rmpp_mad->rmpp_hdr.seg_num = 0;
    rmpp_mad->rmpp_hdr.paylen_newwin = cpu_to_be32(1);

    ret = ib_post_send_mad(msg, NULL);
    if (ret) {
        ib_destroy_ah(msg->ah);
        ib_free_send_mad(msg);
    }
}

void ib_rmpp_send_handler(struct ib_mad_send_wc *mad_send_wc)
{
    if (mad_send_wc->send_buf->context[0] == mad_send_wc->send_buf->ah)
        ib_destroy_ah(mad_send_wc->send_buf->ah);
    ib_free_send_mad(mad_send_wc->send_buf);
}

static void nack_recv(struct ib_mad_agent_private *agent,
              struct ib_mad_recv_wc *recv_wc, u8 rmpp_status)
{
    struct ib_mad_send_buf *msg;
    struct ib_rmpp_mad *rmpp_mad;
    int ret;

    msg = alloc_response_msg(&agent->agent, recv_wc);
    if (IS_ERR(msg))
        return;

    rmpp_mad = msg->mad;
    memcpy(rmpp_mad, recv_wc->recv_buf.mad, msg->hdr_len);

    rmpp_mad->mad_hdr.method ^= IB_MGMT_METHOD_RESP;
    rmpp_mad->rmpp_hdr.rmpp_version = IB_MGMT_RMPP_VERSION;
    rmpp_mad->rmpp_hdr.rmpp_type = IB_MGMT_RMPP_TYPE_ABORT;
    ib_set_rmpp_flags(&rmpp_mad->rmpp_hdr, IB_MGMT_RMPP_FLAG_ACTIVE);
    rmpp_mad->rmpp_hdr.rmpp_status = rmpp_status;
    rmpp_mad->rmpp_hdr.seg_num = 0;
    rmpp_mad->rmpp_hdr.paylen_newwin = 0;

    ret = ib_post_send_mad(msg, NULL);
    if (ret) {
        ib_destroy_ah(msg->ah);
        ib_free_send_mad(msg);
    }
}

static void recv_timeout_handler(struct work_struct *work)
{
    struct mad_rmpp_recv *rmpp_recv =
        container_of(work, struct mad_rmpp_recv, timeout_work.work);
    struct ib_mad_recv_wc *rmpp_wc;
    unsigned long flags;

    spin_lock_irqsave(&rmpp_recv->agent->lock, flags);
    if (rmpp_recv->state != RMPP_STATE_ACTIVE) {
        spin_unlock_irqrestore(&rmpp_recv->agent->lock, flags);
        return;
    }
    rmpp_recv->state = RMPP_STATE_TIMEOUT;
    list_del(&rmpp_recv->list);
    spin_unlock_irqrestore(&rmpp_recv->agent->lock, flags);

    rmpp_wc = rmpp_recv->rmpp_wc;
    nack_recv(rmpp_recv->agent, rmpp_wc, IB_MGMT_RMPP_STATUS_T2L);
    destroy_rmpp_recv(rmpp_recv);
    ib_free_recv_mad(rmpp_wc);
}

static void recv_cleanup_handler(struct work_struct *work)
{
    struct mad_rmpp_recv *rmpp_recv =
        container_of(work, struct mad_rmpp_recv, cleanup_work.work);
    unsigned long flags;

    spin_lock_irqsave(&rmpp_recv->agent->lock, flags);
    if (rmpp_recv->state == RMPP_STATE_CANCELING) {
        spin_unlock_irqrestore(&rmpp_recv->agent->lock, flags);
        return;
    }
    list_del(&rmpp_recv->list);
    spin_unlock_irqrestore(&rmpp_recv->agent->lock, flags);
    destroy_rmpp_recv(rmpp_recv);
}

static struct mad_rmpp_recv *
create_rmpp_recv(struct ib_mad_agent_private *agent,
         struct ib_mad_recv_wc *mad_recv_wc)
{
    struct mad_rmpp_recv *rmpp_recv;
    struct ib_mad_hdr *mad_hdr;

    rmpp_recv = kmalloc(sizeof *rmpp_recv, GFP_KERNEL);
    if (!rmpp_recv)
        return NULL;

    rmpp_recv->ah = ib_create_ah_from_wc(agent->agent.qp->pd,
                         mad_recv_wc->wc,
                         mad_recv_wc->recv_buf.grh,
                         agent->agent.port_num);
    if (IS_ERR(rmpp_recv->ah))
        goto error;

    rmpp_recv->agent = agent;
    init_completion(&rmpp_recv->comp);
    INIT_DELAYED_WORK(&rmpp_recv->timeout_work, recv_timeout_handler);
    INIT_DELAYED_WORK(&rmpp_recv->cleanup_work, recv_cleanup_handler);
    spin_lock_init(&rmpp_recv->lock);
    rmpp_recv->state = RMPP_STATE_ACTIVE;
    atomic_set(&rmpp_recv->refcount, 1);

    rmpp_recv->rmpp_wc = mad_recv_wc;
    rmpp_recv->cur_seg_buf = &mad_recv_wc->recv_buf;
    rmpp_recv->newwin = 1;
    rmpp_recv->seg_num = 1;
    rmpp_recv->last_ack = 0;
    rmpp_recv->repwin = 1;

    mad_hdr = &mad_recv_wc->recv_buf.mad->mad_hdr;
    rmpp_recv->tid = mad_hdr->tid;
    rmpp_recv->src_qp = mad_recv_wc->wc->src_qp;
    rmpp_recv->slid = mad_recv_wc->wc->slid;
    rmpp_recv->mgmt_class = mad_hdr->mgmt_class;
    rmpp_recv->class_version = mad_hdr->class_version;
    rmpp_recv->method  = mad_hdr->method;
    return rmpp_recv;

error:  kfree(rmpp_recv);
    return NULL;
}

static struct mad_rmpp_recv *
find_rmpp_recv(struct ib_mad_agent_private *agent,
           struct ib_mad_recv_wc *mad_recv_wc)
{
    struct mad_rmpp_recv *rmpp_recv;
    struct ib_mad_hdr *mad_hdr = &mad_recv_wc->recv_buf.mad->mad_hdr;

    list_for_each_entry(rmpp_recv, &agent->rmpp_list, list) {
        if (rmpp_recv->tid == mad_hdr->tid &&
            rmpp_recv->src_qp == mad_recv_wc->wc->src_qp &&
            rmpp_recv->slid == mad_recv_wc->wc->slid &&
            rmpp_recv->mgmt_class == mad_hdr->mgmt_class &&
            rmpp_recv->class_version == mad_hdr->class_version &&
            rmpp_recv->method == mad_hdr->method)
            return rmpp_recv;
    }
    return NULL;
}

static struct mad_rmpp_recv *
acquire_rmpp_recv(struct ib_mad_agent_private *agent,
          struct ib_mad_recv_wc *mad_recv_wc)
{
    struct mad_rmpp_recv *rmpp_recv;
    unsigned long flags;

    spin_lock_irqsave(&agent->lock, flags);
    rmpp_recv = find_rmpp_recv(agent, mad_recv_wc);
    if (rmpp_recv)
        atomic_inc(&rmpp_recv->refcount);
    spin_unlock_irqrestore(&agent->lock, flags);
    return rmpp_recv;
}

static struct mad_rmpp_recv *
insert_rmpp_recv(struct ib_mad_agent_private *agent,
         struct mad_rmpp_recv *rmpp_recv)
{
    struct mad_rmpp_recv *cur_rmpp_recv;

    cur_rmpp_recv = find_rmpp_recv(agent, rmpp_recv->rmpp_wc);
    if (!cur_rmpp_recv)
        list_add_tail(&rmpp_recv->list, &agent->rmpp_list);

    return cur_rmpp_recv;
}

static inline int get_last_flag(struct ib_mad_recv_buf *seg)
{
    struct ib_rmpp_mad *rmpp_mad;

    rmpp_mad = (struct ib_rmpp_mad *) seg->mad;
    return ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) & IB_MGMT_RMPP_FLAG_LAST;
}

static inline int get_seg_num(struct ib_mad_recv_buf *seg)
{
    struct ib_rmpp_mad *rmpp_mad;

    rmpp_mad = (struct ib_rmpp_mad *) seg->mad;
    return be32_to_cpu(rmpp_mad->rmpp_hdr.seg_num);
}

static inline struct ib_mad_recv_buf * get_next_seg(struct list_head *rmpp_list,
                            struct ib_mad_recv_buf *seg)
{
    if (seg->list.next == rmpp_list)
        return NULL;

    return container_of(seg->list.next, struct ib_mad_recv_buf, list);
}

static inline int window_size(struct ib_mad_agent_private *agent)
{
    return max(agent->qp_info->recv_queue.max_active >> 3, 1);
}

static struct ib_mad_recv_buf * find_seg_location(struct list_head *rmpp_list,
                          int seg_num)
{
    struct ib_mad_recv_buf *seg_buf;
    int cur_seg_num;

    list_for_each_entry_reverse(seg_buf, rmpp_list, list) {
        cur_seg_num = get_seg_num(seg_buf);
        if (seg_num > cur_seg_num)
            return seg_buf;
        if (seg_num == cur_seg_num)
            break;
    }
    return NULL;
}

static void update_seg_num(struct mad_rmpp_recv *rmpp_recv,
               struct ib_mad_recv_buf *new_buf)
{
    struct list_head *rmpp_list = &rmpp_recv->rmpp_wc->rmpp_list;

    while (new_buf && (get_seg_num(new_buf) == rmpp_recv->seg_num + 1)) {
        rmpp_recv->cur_seg_buf = new_buf;
        rmpp_recv->seg_num++;
        new_buf = get_next_seg(rmpp_list, new_buf);
    }
}

static inline int get_mad_len(struct mad_rmpp_recv *rmpp_recv)
{
    struct ib_rmpp_mad *rmpp_mad;
    int hdr_size, data_size, pad;

    rmpp_mad = (struct ib_rmpp_mad *)rmpp_recv->cur_seg_buf->mad;

    hdr_size = ib_get_mad_data_offset(rmpp_mad->mad_hdr.mgmt_class);
    data_size = sizeof(struct ib_rmpp_mad) - hdr_size;
    pad = IB_MGMT_RMPP_DATA - be32_to_cpu(rmpp_mad->rmpp_hdr.paylen_newwin);
    if (pad > IB_MGMT_RMPP_DATA || pad < 0)
        pad = 0;

    return hdr_size + rmpp_recv->seg_num * data_size - pad;
}

static struct ib_mad_recv_wc * complete_rmpp(struct mad_rmpp_recv *rmpp_recv)
{
    struct ib_mad_recv_wc *rmpp_wc;

    ack_recv(rmpp_recv, rmpp_recv->rmpp_wc);
    if (rmpp_recv->seg_num > 1)
        cancel_delayed_work(&rmpp_recv->timeout_work);

    rmpp_wc = rmpp_recv->rmpp_wc;
    rmpp_wc->mad_len = get_mad_len(rmpp_recv);
    /* 10 seconds until we can find the packet lifetime */
    queue_delayed_work(rmpp_recv->agent->qp_info->port_priv->wq,
               &rmpp_recv->cleanup_work, msecs_to_jiffies(10000));
    return rmpp_wc;
}

static struct ib_mad_recv_wc *
continue_rmpp(struct ib_mad_agent_private *agent,
          struct ib_mad_recv_wc *mad_recv_wc)
{
    struct mad_rmpp_recv *rmpp_recv;
    struct ib_mad_recv_buf *prev_buf;
    struct ib_mad_recv_wc *done_wc;
    int seg_num;
    unsigned long flags;

    rmpp_recv = acquire_rmpp_recv(agent, mad_recv_wc);
    if (!rmpp_recv)
        goto drop1;

    seg_num = get_seg_num(&mad_recv_wc->recv_buf);

    spin_lock_irqsave(&rmpp_recv->lock, flags);
    if ((rmpp_recv->state == RMPP_STATE_TIMEOUT) ||
        (seg_num > rmpp_recv->newwin))
        goto drop3;

    if ((seg_num <= rmpp_recv->last_ack) ||
        (rmpp_recv->state == RMPP_STATE_COMPLETE)) {
        spin_unlock_irqrestore(&rmpp_recv->lock, flags);
        ack_recv(rmpp_recv, mad_recv_wc);
        goto drop2;
    }

    prev_buf = find_seg_location(&rmpp_recv->rmpp_wc->rmpp_list, seg_num);
    if (!prev_buf)
        goto drop3;

    done_wc = NULL;
    list_add(&mad_recv_wc->recv_buf.list, &prev_buf->list);
    if (rmpp_recv->cur_seg_buf == prev_buf) {
        update_seg_num(rmpp_recv, &mad_recv_wc->recv_buf);
        if (get_last_flag(rmpp_recv->cur_seg_buf)) {
            rmpp_recv->state = RMPP_STATE_COMPLETE;
            spin_unlock_irqrestore(&rmpp_recv->lock, flags);
            done_wc = complete_rmpp(rmpp_recv);
            goto out;
        } else if (rmpp_recv->seg_num == rmpp_recv->newwin) {
            rmpp_recv->newwin += window_size(agent);
            spin_unlock_irqrestore(&rmpp_recv->lock, flags);
            ack_recv(rmpp_recv, mad_recv_wc);
            goto out;
        }
    }
    spin_unlock_irqrestore(&rmpp_recv->lock, flags);
out:
    deref_rmpp_recv(rmpp_recv);
    return done_wc;

drop3:  spin_unlock_irqrestore(&rmpp_recv->lock, flags);
drop2:  deref_rmpp_recv(rmpp_recv);
drop1:  ib_free_recv_mad(mad_recv_wc);
    return NULL;
}

static struct ib_mad_recv_wc *
start_rmpp(struct ib_mad_agent_private *agent,
       struct ib_mad_recv_wc *mad_recv_wc)
{
    struct mad_rmpp_recv *rmpp_recv;
    unsigned long flags;

    rmpp_recv = create_rmpp_recv(agent, mad_recv_wc);
    if (!rmpp_recv) {
        ib_free_recv_mad(mad_recv_wc);
        return NULL;
    }

    spin_lock_irqsave(&agent->lock, flags);
    if (insert_rmpp_recv(agent, rmpp_recv)) {
        spin_unlock_irqrestore(&agent->lock, flags);
        /* duplicate first MAD */
        destroy_rmpp_recv(rmpp_recv);
        return continue_rmpp(agent, mad_recv_wc);
    }
    atomic_inc(&rmpp_recv->refcount);

    if (get_last_flag(&mad_recv_wc->recv_buf)) {
        rmpp_recv->state = RMPP_STATE_COMPLETE;
        spin_unlock_irqrestore(&agent->lock, flags);
        complete_rmpp(rmpp_recv);
    } else {
        spin_unlock_irqrestore(&agent->lock, flags);
        /* 40 seconds until we can find the packet lifetimes */
        queue_delayed_work(agent->qp_info->port_priv->wq,
                   &rmpp_recv->timeout_work,
                   msecs_to_jiffies(40000));
        rmpp_recv->newwin += window_size(agent);
        ack_recv(rmpp_recv, mad_recv_wc);
        mad_recv_wc = NULL;
    }
    deref_rmpp_recv(rmpp_recv);
    return mad_recv_wc;
}

static int send_next_seg(struct ib_mad_send_wr_private *mad_send_wr)
{
    struct ib_rmpp_mad *rmpp_mad;
    int timeout;
    u32 paylen = 0;

    rmpp_mad = mad_send_wr->send_buf.mad;
    ib_set_rmpp_flags(&rmpp_mad->rmpp_hdr, IB_MGMT_RMPP_FLAG_ACTIVE);
    rmpp_mad->rmpp_hdr.seg_num = cpu_to_be32(++mad_send_wr->seg_num);

    if (mad_send_wr->seg_num == 1) {
        rmpp_mad->rmpp_hdr.rmpp_rtime_flags |= IB_MGMT_RMPP_FLAG_FIRST;
        paylen = mad_send_wr->send_buf.seg_count * IB_MGMT_RMPP_DATA -
             mad_send_wr->pad;
    }

    if (mad_send_wr->seg_num == mad_send_wr->send_buf.seg_count) {
        rmpp_mad->rmpp_hdr.rmpp_rtime_flags |= IB_MGMT_RMPP_FLAG_LAST;
        paylen = IB_MGMT_RMPP_DATA - mad_send_wr->pad;
    }
    rmpp_mad->rmpp_hdr.paylen_newwin = cpu_to_be32(paylen);

    /* 2 seconds for an ACK until we can find the packet lifetime */
    timeout = mad_send_wr->send_buf.timeout_ms;
    if (!timeout || timeout > 2000)
        mad_send_wr->timeout = msecs_to_jiffies(2000);

    return ib_send_mad(mad_send_wr);
}

static void abort_send(struct ib_mad_agent_private *agent,
               struct ib_mad_recv_wc *mad_recv_wc, u8 rmpp_status)
{
    struct ib_mad_send_wr_private *mad_send_wr;
    struct ib_mad_send_wc wc;
    unsigned long flags;

    spin_lock_irqsave(&agent->lock, flags);
    mad_send_wr = ib_find_send_mad(agent, mad_recv_wc);
    if (!mad_send_wr)
        goto out;   /* Unmatched send */

    if ((mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) ||
        (!mad_send_wr->timeout) || (mad_send_wr->status != IB_WC_SUCCESS))
        goto out;   /* Send is already done */

    ib_mark_mad_done(mad_send_wr);
    spin_unlock_irqrestore(&agent->lock, flags);

    wc.status = IB_WC_REM_ABORT_ERR;
    wc.vendor_err = rmpp_status;
    wc.send_buf = &mad_send_wr->send_buf;
    ib_mad_complete_send_wr(mad_send_wr, &wc);
    return;
out:
    spin_unlock_irqrestore(&agent->lock, flags);
}

static inline void adjust_last_ack(struct ib_mad_send_wr_private *wr,
                   int seg_num)
{
    struct list_head *list;

    wr->last_ack = seg_num;
    list = &wr->last_ack_seg->list;
    list_for_each_entry(wr->last_ack_seg, list, list)
        if (wr->last_ack_seg->num == seg_num)
            break;
}

static void process_ds_ack(struct ib_mad_agent_private *agent,
               struct ib_mad_recv_wc *mad_recv_wc, int newwin)
{
    struct mad_rmpp_recv *rmpp_recv;

    rmpp_recv = find_rmpp_recv(agent, mad_recv_wc);
    if (rmpp_recv && rmpp_recv->state == RMPP_STATE_COMPLETE)
        rmpp_recv->repwin = newwin;
}

static void process_rmpp_ack(struct ib_mad_agent_private *agent,
                 struct ib_mad_recv_wc *mad_recv_wc)
{
    struct ib_mad_send_wr_private *mad_send_wr;
    struct ib_rmpp_mad *rmpp_mad;
    unsigned long flags;
    int seg_num, newwin, ret;

    rmpp_mad = (struct ib_rmpp_mad *)mad_recv_wc->recv_buf.mad;
    if (rmpp_mad->rmpp_hdr.rmpp_status) {
        abort_send(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_BAD_STATUS);
        nack_recv(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_BAD_STATUS);
        return;
    }

    seg_num = be32_to_cpu(rmpp_mad->rmpp_hdr.seg_num);
    newwin = be32_to_cpu(rmpp_mad->rmpp_hdr.paylen_newwin);
    if (newwin < seg_num) {
        abort_send(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_W2S);
        nack_recv(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_W2S);
        return;
    }

    spin_lock_irqsave(&agent->lock, flags);
    mad_send_wr = ib_find_send_mad(agent, mad_recv_wc);
    if (!mad_send_wr) {
        if (!seg_num)
            process_ds_ack(agent, mad_recv_wc, newwin);
        goto out;   /* Unmatched or DS RMPP ACK */
    }

    if ((mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) &&
        (mad_send_wr->timeout)) {
        spin_unlock_irqrestore(&agent->lock, flags);
        ack_ds_ack(agent, mad_recv_wc);
        return;     /* Repeated ACK for DS RMPP transaction */
    }

    if ((mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) ||
        (!mad_send_wr->timeout) || (mad_send_wr->status != IB_WC_SUCCESS))
        goto out;   /* Send is already done */

    if (seg_num > mad_send_wr->send_buf.seg_count ||
        seg_num > mad_send_wr->newwin) {
        spin_unlock_irqrestore(&agent->lock, flags);
        abort_send(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_S2B);
        nack_recv(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_S2B);
        return;
    }

    if (newwin < mad_send_wr->newwin || seg_num < mad_send_wr->last_ack)
        goto out;   /* Old ACK */

    if (seg_num > mad_send_wr->last_ack) {
        adjust_last_ack(mad_send_wr, seg_num);
        mad_send_wr->retries_left = mad_send_wr->max_retries;
    }
    mad_send_wr->newwin = newwin;
    if (mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) {
        /* If no response is expected, the ACK completes the send */
        if (!mad_send_wr->send_buf.timeout_ms) {
            struct ib_mad_send_wc wc;

            ib_mark_mad_done(mad_send_wr);
            spin_unlock_irqrestore(&agent->lock, flags);

            wc.status = IB_WC_SUCCESS;
            wc.vendor_err = 0;
            wc.send_buf = &mad_send_wr->send_buf;
            ib_mad_complete_send_wr(mad_send_wr, &wc);
            return;
        }
        if (mad_send_wr->refcount == 1)
            ib_reset_mad_timeout(mad_send_wr,
                         mad_send_wr->send_buf.timeout_ms);
        spin_unlock_irqrestore(&agent->lock, flags);
        ack_ds_ack(agent, mad_recv_wc);
        return;
    } else if (mad_send_wr->refcount == 1 &&
           mad_send_wr->seg_num < mad_send_wr->newwin &&
           mad_send_wr->seg_num < mad_send_wr->send_buf.seg_count) {
        /* Send failure will just result in a timeout/retry */
        ret = send_next_seg(mad_send_wr);
        if (ret)
            goto out;

        mad_send_wr->refcount++;
        list_move_tail(&mad_send_wr->agent_list,
                  &mad_send_wr->mad_agent_priv->send_list);
    }
out:
    spin_unlock_irqrestore(&agent->lock, flags);
}

static struct ib_mad_recv_wc *
process_rmpp_data(struct ib_mad_agent_private *agent,
          struct ib_mad_recv_wc *mad_recv_wc)
{
    struct ib_rmpp_hdr *rmpp_hdr;
    u8 rmpp_status;

    rmpp_hdr = &((struct ib_rmpp_mad *)mad_recv_wc->recv_buf.mad)->rmpp_hdr;

    if (rmpp_hdr->rmpp_status) {
        rmpp_status = IB_MGMT_RMPP_STATUS_BAD_STATUS;
        goto bad;
    }

    if (rmpp_hdr->seg_num == cpu_to_be32(1)) {
        if (!(ib_get_rmpp_flags(rmpp_hdr) & IB_MGMT_RMPP_FLAG_FIRST)) {
            rmpp_status = IB_MGMT_RMPP_STATUS_BAD_SEG;
            goto bad;
        }
        return start_rmpp(agent, mad_recv_wc);
    } else {
        if (ib_get_rmpp_flags(rmpp_hdr) & IB_MGMT_RMPP_FLAG_FIRST) {
            rmpp_status = IB_MGMT_RMPP_STATUS_BAD_SEG;
            goto bad;
        }
        return continue_rmpp(agent, mad_recv_wc);
    }
bad:
    nack_recv(agent, mad_recv_wc, rmpp_status);
    ib_free_recv_mad(mad_recv_wc);
    return NULL;
}

static void process_rmpp_stop(struct ib_mad_agent_private *agent,
                  struct ib_mad_recv_wc *mad_recv_wc)
{
    struct ib_rmpp_mad *rmpp_mad;

    rmpp_mad = (struct ib_rmpp_mad *)mad_recv_wc->recv_buf.mad;

    if (rmpp_mad->rmpp_hdr.rmpp_status != IB_MGMT_RMPP_STATUS_RESX) {
        abort_send(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_BAD_STATUS);
        nack_recv(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_BAD_STATUS);
    } else
        abort_send(agent, mad_recv_wc, rmpp_mad->rmpp_hdr.rmpp_status);
}

static void process_rmpp_abort(struct ib_mad_agent_private *agent,
                   struct ib_mad_recv_wc *mad_recv_wc)
{
    struct ib_rmpp_mad *rmpp_mad;

    rmpp_mad = (struct ib_rmpp_mad *)mad_recv_wc->recv_buf.mad;

    if (rmpp_mad->rmpp_hdr.rmpp_status < IB_MGMT_RMPP_STATUS_ABORT_MIN ||
        rmpp_mad->rmpp_hdr.rmpp_status > IB_MGMT_RMPP_STATUS_ABORT_MAX) {
        abort_send(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_BAD_STATUS);
        nack_recv(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_BAD_STATUS);
    } else
        abort_send(agent, mad_recv_wc, rmpp_mad->rmpp_hdr.rmpp_status);
}

struct ib_mad_recv_wc *
ib_process_rmpp_recv_wc(struct ib_mad_agent_private *agent,
            struct ib_mad_recv_wc *mad_recv_wc)
{
    struct ib_rmpp_mad *rmpp_mad;

    rmpp_mad = (struct ib_rmpp_mad *)mad_recv_wc->recv_buf.mad;
    if (!(rmpp_mad->rmpp_hdr.rmpp_rtime_flags & IB_MGMT_RMPP_FLAG_ACTIVE))
        return mad_recv_wc;

    if (rmpp_mad->rmpp_hdr.rmpp_version != IB_MGMT_RMPP_VERSION) {
        abort_send(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_UNV);
        nack_recv(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_UNV);
        goto out;
    }

    switch (rmpp_mad->rmpp_hdr.rmpp_type) {
    case IB_MGMT_RMPP_TYPE_DATA:
        return process_rmpp_data(agent, mad_recv_wc);
    case IB_MGMT_RMPP_TYPE_ACK:
        process_rmpp_ack(agent, mad_recv_wc);
        break;
    case IB_MGMT_RMPP_TYPE_STOP:
        process_rmpp_stop(agent, mad_recv_wc);
        break;
    case IB_MGMT_RMPP_TYPE_ABORT:
        process_rmpp_abort(agent, mad_recv_wc);
        break;
    default:
        abort_send(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_BADT);
        nack_recv(agent, mad_recv_wc, IB_MGMT_RMPP_STATUS_BADT);
        break;
    }
out:
    ib_free_recv_mad(mad_recv_wc);
    return NULL;
}

static int init_newwin(struct ib_mad_send_wr_private *mad_send_wr)
{
    struct ib_mad_agent_private *agent = mad_send_wr->mad_agent_priv;
    struct ib_mad_hdr *mad_hdr = mad_send_wr->send_buf.mad;
    struct mad_rmpp_recv *rmpp_recv;
    struct ib_ah_attr ah_attr;
    unsigned long flags;
    int newwin = 1;

    if (!(mad_hdr->method & IB_MGMT_METHOD_RESP))
        goto out;

    spin_lock_irqsave(&agent->lock, flags);
    list_for_each_entry(rmpp_recv, &agent->rmpp_list, list) {
        if (rmpp_recv->tid != mad_hdr->tid ||
            rmpp_recv->mgmt_class != mad_hdr->mgmt_class ||
            rmpp_recv->class_version != mad_hdr->class_version ||
            (rmpp_recv->method & IB_MGMT_METHOD_RESP))
            continue;

        if (ib_query_ah(mad_send_wr->send_buf.ah, &ah_attr))
            continue;

        if (rmpp_recv->slid == ah_attr.dlid) {
            newwin = rmpp_recv->repwin;
            break;
        }
    }
    spin_unlock_irqrestore(&agent->lock, flags);
out:
    return newwin;
}

int ib_send_rmpp_mad(struct ib_mad_send_wr_private *mad_send_wr)
{
    struct ib_rmpp_mad *rmpp_mad;
    int ret;

    rmpp_mad = mad_send_wr->send_buf.mad;
    if (!(ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) &
          IB_MGMT_RMPP_FLAG_ACTIVE))
        return IB_RMPP_RESULT_UNHANDLED;

    if (rmpp_mad->rmpp_hdr.rmpp_type != IB_MGMT_RMPP_TYPE_DATA) {
        mad_send_wr->seg_num = 1;
        return IB_RMPP_RESULT_INTERNAL;
    }

    mad_send_wr->newwin = init_newwin(mad_send_wr);

    /* We need to wait for the final ACK even if there isn't a response */
    mad_send_wr->refcount += (mad_send_wr->timeout == 0);
    ret = send_next_seg(mad_send_wr);
    if (!ret)
        return IB_RMPP_RESULT_CONSUMED;
    return ret;
}

int ib_process_rmpp_send_wc(struct ib_mad_send_wr_private *mad_send_wr,
                struct ib_mad_send_wc *mad_send_wc)
{
    struct ib_rmpp_mad *rmpp_mad;
    int ret;

    rmpp_mad = mad_send_wr->send_buf.mad;
    if (!(ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) &
          IB_MGMT_RMPP_FLAG_ACTIVE))
        return IB_RMPP_RESULT_UNHANDLED; /* RMPP not active */

    if (rmpp_mad->rmpp_hdr.rmpp_type != IB_MGMT_RMPP_TYPE_DATA)
        return IB_RMPP_RESULT_INTERNAL;  /* ACK, STOP, or ABORT */

    if (mad_send_wc->status != IB_WC_SUCCESS ||
        mad_send_wr->status != IB_WC_SUCCESS)
        return IB_RMPP_RESULT_PROCESSED; /* Canceled or send error */

    if (!mad_send_wr->timeout)
        return IB_RMPP_RESULT_PROCESSED; /* Response received */

    if (mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count) {
        mad_send_wr->timeout =
            msecs_to_jiffies(mad_send_wr->send_buf.timeout_ms);
        return IB_RMPP_RESULT_PROCESSED; /* Send done */
    }

    if (mad_send_wr->seg_num == mad_send_wr->newwin ||
        mad_send_wr->seg_num == mad_send_wr->send_buf.seg_count)
        return IB_RMPP_RESULT_PROCESSED; /* Wait for ACK */

    ret = send_next_seg(mad_send_wr);
    if (ret) {
        mad_send_wc->status = IB_WC_GENERAL_ERR;
        return IB_RMPP_RESULT_PROCESSED;
    }
    return IB_RMPP_RESULT_CONSUMED;
}

int ib_retry_rmpp(struct ib_mad_send_wr_private *mad_send_wr)
{
    struct ib_rmpp_mad *rmpp_mad;
    int ret;

    rmpp_mad = mad_send_wr->send_buf.mad;
    if (!(ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) &
          IB_MGMT_RMPP_FLAG_ACTIVE))
        return IB_RMPP_RESULT_UNHANDLED; /* RMPP not active */

    if (mad_send_wr->last_ack == mad_send_wr->send_buf.seg_count)
        return IB_RMPP_RESULT_PROCESSED;

    mad_send_wr->seg_num = mad_send_wr->last_ack;
    mad_send_wr->cur_seg = mad_send_wr->last_ack_seg;

    ret = send_next_seg(mad_send_wr);
    if (ret)
        return IB_RMPP_RESULT_PROCESSED;

    return IB_RMPP_RESULT_CONSUMED;
}