cq.c

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/*
 * Copyright (c) 2009-2010 Chelsio, 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 "iw_cxgb4.h"

static int destroy_cq(struct c4iw_rdev *rdev, struct t4_cq *cq,
              struct c4iw_dev_ucontext *uctx)
{
    struct fw_ri_res_wr *res_wr;
    struct fw_ri_res *res;
    int wr_len;
    struct c4iw_wr_wait wr_wait;
    struct sk_buff *skb;
    int ret;

    wr_len = sizeof *res_wr + sizeof *res;
    skb = alloc_skb(wr_len, GFP_KERNEL);
    if (!skb)
        return -ENOMEM;
    set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);

    res_wr = (struct fw_ri_res_wr *)__skb_put(skb, wr_len);
    memset(res_wr, 0, wr_len);
    res_wr->op_nres = cpu_to_be32(
            FW_WR_OP(FW_RI_RES_WR) |
            V_FW_RI_RES_WR_NRES(1) |
            FW_WR_COMPL(1));
    res_wr->len16_pkd = cpu_to_be32(DIV_ROUND_UP(wr_len, 16));
    res_wr->cookie = (unsigned long) &wr_wait;
    res = res_wr->res;
    res->u.cq.restype = FW_RI_RES_TYPE_CQ;
    res->u.cq.op = FW_RI_RES_OP_RESET;
    res->u.cq.iqid = cpu_to_be32(cq->cqid);

    c4iw_init_wr_wait(&wr_wait);
    ret = c4iw_ofld_send(rdev, skb);
    if (!ret) {
        ret = c4iw_wait_for_reply(rdev, &wr_wait, 0, 0, __func__);
    }

    kfree(cq->sw_queue);
    dma_free_coherent(&(rdev->lldi.pdev->dev),
              cq->memsize, cq->queue,
              dma_unmap_addr(cq, mapping));
    c4iw_put_cqid(rdev, cq->cqid, uctx);
    return ret;
}

static int create_cq(struct c4iw_rdev *rdev, struct t4_cq *cq,
             struct c4iw_dev_ucontext *uctx)
{
    struct fw_ri_res_wr *res_wr;
    struct fw_ri_res *res;
    int wr_len;
    int user = (uctx != &rdev->uctx);
    struct c4iw_wr_wait wr_wait;
    int ret;
    struct sk_buff *skb;

    cq->cqid = c4iw_get_cqid(rdev, uctx);
    if (!cq->cqid) {
        ret = -ENOMEM;
        goto err1;
    }

    if (!user) {
        cq->sw_queue = kzalloc(cq->memsize, GFP_KERNEL);
        if (!cq->sw_queue) {
            ret = -ENOMEM;
            goto err2;
        }
    }
    cq->queue = dma_alloc_coherent(&rdev->lldi.pdev->dev, cq->memsize,
                       &cq->dma_addr, GFP_KERNEL);
    if (!cq->queue) {
        ret = -ENOMEM;
        goto err3;
    }
    dma_unmap_addr_set(cq, mapping, cq->dma_addr);
    memset(cq->queue, 0, cq->memsize);

    /* build fw_ri_res_wr */
    wr_len = sizeof *res_wr + sizeof *res;

    skb = alloc_skb(wr_len, GFP_KERNEL);
    if (!skb) {
        ret = -ENOMEM;
        goto err4;
    }
    set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);

    res_wr = (struct fw_ri_res_wr *)__skb_put(skb, wr_len);
    memset(res_wr, 0, wr_len);
    res_wr->op_nres = cpu_to_be32(
            FW_WR_OP(FW_RI_RES_WR) |
            V_FW_RI_RES_WR_NRES(1) |
            FW_WR_COMPL(1));
    res_wr->len16_pkd = cpu_to_be32(DIV_ROUND_UP(wr_len, 16));
    res_wr->cookie = (unsigned long) &wr_wait;
    res = res_wr->res;
    res->u.cq.restype = FW_RI_RES_TYPE_CQ;
    res->u.cq.op = FW_RI_RES_OP_WRITE;
    res->u.cq.iqid = cpu_to_be32(cq->cqid);
    res->u.cq.iqandst_to_iqandstindex = cpu_to_be32(
            V_FW_RI_RES_WR_IQANUS(0) |
            V_FW_RI_RES_WR_IQANUD(1) |
            F_FW_RI_RES_WR_IQANDST |
            V_FW_RI_RES_WR_IQANDSTINDEX(*rdev->lldi.rxq_ids));
    res->u.cq.iqdroprss_to_iqesize = cpu_to_be16(
            F_FW_RI_RES_WR_IQDROPRSS |
            V_FW_RI_RES_WR_IQPCIECH(2) |
            V_FW_RI_RES_WR_IQINTCNTTHRESH(0) |
            F_FW_RI_RES_WR_IQO |
            V_FW_RI_RES_WR_IQESIZE(1));
    res->u.cq.iqsize = cpu_to_be16(cq->size);
    res->u.cq.iqaddr = cpu_to_be64(cq->dma_addr);

    c4iw_init_wr_wait(&wr_wait);

    ret = c4iw_ofld_send(rdev, skb);
    if (ret)
        goto err4;
    PDBG("%s wait_event wr_wait %p\n", __func__, &wr_wait);
    ret = c4iw_wait_for_reply(rdev, &wr_wait, 0, 0, __func__);
    if (ret)
        goto err4;

    cq->gen = 1;
    cq->gts = rdev->lldi.gts_reg;
    cq->rdev = rdev;
    if (user) {
        cq->ugts = (u64)pci_resource_start(rdev->lldi.pdev, 2) +
                    (cq->cqid << rdev->cqshift);
        cq->ugts &= PAGE_MASK;
    }
    return 0;
err4:
    dma_free_coherent(&rdev->lldi.pdev->dev, cq->memsize, cq->queue,
              dma_unmap_addr(cq, mapping));
err3:
    kfree(cq->sw_queue);
err2:
    c4iw_put_cqid(rdev, cq->cqid, uctx);
err1:
    return ret;
}

static void insert_recv_cqe(struct t4_wq *wq, struct t4_cq *cq)
{
    struct t4_cqe cqe;

    PDBG("%s wq %p cq %p sw_cidx %u sw_pidx %u\n", __func__,
         wq, cq, cq->sw_cidx, cq->sw_pidx);
    memset(&cqe, 0, sizeof(cqe));
    cqe.header = cpu_to_be32(V_CQE_STATUS(T4_ERR_SWFLUSH) |
                 V_CQE_OPCODE(FW_RI_SEND) |
                 V_CQE_TYPE(0) |
                 V_CQE_SWCQE(1) |
                 V_CQE_QPID(wq->sq.qid));
    cqe.bits_type_ts = cpu_to_be64(V_CQE_GENBIT((u64)cq->gen));
    cq->sw_queue[cq->sw_pidx] = cqe;
    t4_swcq_produce(cq);
}

int c4iw_flush_rq(struct t4_wq *wq, struct t4_cq *cq, int count)
{
    int flushed = 0;
    int in_use = wq->rq.in_use - count;

    BUG_ON(in_use < 0);
    PDBG("%s wq %p cq %p rq.in_use %u skip count %u\n", __func__,
         wq, cq, wq->rq.in_use, count);
    while (in_use--) {
        insert_recv_cqe(wq, cq);
        flushed++;
    }
    return flushed;
}

static void insert_sq_cqe(struct t4_wq *wq, struct t4_cq *cq,
              struct t4_swsqe *swcqe)
{
    struct t4_cqe cqe;

    PDBG("%s wq %p cq %p sw_cidx %u sw_pidx %u\n", __func__,
         wq, cq, cq->sw_cidx, cq->sw_pidx);
    memset(&cqe, 0, sizeof(cqe));
    cqe.header = cpu_to_be32(V_CQE_STATUS(T4_ERR_SWFLUSH) |
                 V_CQE_OPCODE(swcqe->opcode) |
                 V_CQE_TYPE(1) |
                 V_CQE_SWCQE(1) |
                 V_CQE_QPID(wq->sq.qid));
    CQE_WRID_SQ_IDX(&cqe) = swcqe->idx;
    cqe.bits_type_ts = cpu_to_be64(V_CQE_GENBIT((u64)cq->gen));
    cq->sw_queue[cq->sw_pidx] = cqe;
    t4_swcq_produce(cq);
}

int c4iw_flush_sq(struct t4_wq *wq, struct t4_cq *cq, int count)
{
    int flushed = 0;
    struct t4_swsqe *swsqe = &wq->sq.sw_sq[wq->sq.cidx + count];
    int in_use = wq->sq.in_use - count;

    BUG_ON(in_use < 0);
    while (in_use--) {
        swsqe->signaled = 0;
        insert_sq_cqe(wq, cq, swsqe);
        swsqe++;
        if (swsqe == (wq->sq.sw_sq + wq->sq.size))
            swsqe = wq->sq.sw_sq;
        flushed++;
    }
    return flushed;
}

/*
 * Move all CQEs from the HWCQ into the SWCQ.
 */
void c4iw_flush_hw_cq(struct t4_cq *cq)
{
    struct t4_cqe *cqe = NULL, *swcqe;
    int ret;

    PDBG("%s cq %p cqid 0x%x\n", __func__, cq, cq->cqid);
    ret = t4_next_hw_cqe(cq, &cqe);
    while (!ret) {
        PDBG("%s flushing hwcq cidx 0x%x swcq pidx 0x%x\n",
             __func__, cq->cidx, cq->sw_pidx);
        swcqe = &cq->sw_queue[cq->sw_pidx];
        *swcqe = *cqe;
        swcqe->header |= cpu_to_be32(V_CQE_SWCQE(1));
        t4_swcq_produce(cq);
        t4_hwcq_consume(cq);
        ret = t4_next_hw_cqe(cq, &cqe);
    }
}

static int cqe_completes_wr(struct t4_cqe *cqe, struct t4_wq *wq)
{
    if (CQE_OPCODE(cqe) == FW_RI_TERMINATE)
        return 0;

    if ((CQE_OPCODE(cqe) == FW_RI_RDMA_WRITE) && RQ_TYPE(cqe))
        return 0;

    if ((CQE_OPCODE(cqe) == FW_RI_READ_RESP) && SQ_TYPE(cqe))
        return 0;

    if (CQE_SEND_OPCODE(cqe) && RQ_TYPE(cqe) && t4_rq_empty(wq))
        return 0;
    return 1;
}

void c4iw_count_scqes(struct t4_cq *cq, struct t4_wq *wq, int *count)
{
    struct t4_cqe *cqe;
    u32 ptr;

    *count = 0;
    ptr = cq->sw_cidx;
    while (ptr != cq->sw_pidx) {
        cqe = &cq->sw_queue[ptr];
        if ((SQ_TYPE(cqe) || ((CQE_OPCODE(cqe) == FW_RI_READ_RESP) &&
                      wq->sq.oldest_read)) &&
            (CQE_QPID(cqe) == wq->sq.qid))
            (*count)++;
        if (++ptr == cq->size)
            ptr = 0;
    }
    PDBG("%s cq %p count %d\n", __func__, cq, *count);
}

void c4iw_count_rcqes(struct t4_cq *cq, struct t4_wq *wq, int *count)
{
    struct t4_cqe *cqe;
    u32 ptr;

    *count = 0;
    PDBG("%s count zero %d\n", __func__, *count);
    ptr = cq->sw_cidx;
    while (ptr != cq->sw_pidx) {
        cqe = &cq->sw_queue[ptr];
        if (RQ_TYPE(cqe) && (CQE_OPCODE(cqe) != FW_RI_READ_RESP) &&
            (CQE_QPID(cqe) == wq->sq.qid) && cqe_completes_wr(cqe, wq))
            (*count)++;
        if (++ptr == cq->size)
            ptr = 0;
    }
    PDBG("%s cq %p count %d\n", __func__, cq, *count);
}

static void flush_completed_wrs(struct t4_wq *wq, struct t4_cq *cq)
{
    struct t4_swsqe *swsqe;
    u16 ptr = wq->sq.cidx;
    int count = wq->sq.in_use;
    int unsignaled = 0;

    swsqe = &wq->sq.sw_sq[ptr];
    while (count--)
        if (!swsqe->signaled) {
            if (++ptr == wq->sq.size)
                ptr = 0;
            swsqe = &wq->sq.sw_sq[ptr];
            unsignaled++;
        } else if (swsqe->complete) {

            /*
             * Insert this completed cqe into the swcq.
             */
            PDBG("%s moving cqe into swcq sq idx %u cq idx %u\n",
                 __func__, ptr, cq->sw_pidx);
            swsqe->cqe.header |= htonl(V_CQE_SWCQE(1));
            cq->sw_queue[cq->sw_pidx] = swsqe->cqe;
            t4_swcq_produce(cq);
            swsqe->signaled = 0;
            wq->sq.in_use -= unsignaled;
            break;
        } else
            break;
}

static void create_read_req_cqe(struct t4_wq *wq, struct t4_cqe *hw_cqe,
                struct t4_cqe *read_cqe)
{
    read_cqe->u.scqe.cidx = wq->sq.oldest_read->idx;
    read_cqe->len = cpu_to_be32(wq->sq.oldest_read->read_len);
    read_cqe->header = htonl(V_CQE_QPID(CQE_QPID(hw_cqe)) |
                 V_CQE_SWCQE(SW_CQE(hw_cqe)) |
                 V_CQE_OPCODE(FW_RI_READ_REQ) |
                 V_CQE_TYPE(1));
    read_cqe->bits_type_ts = hw_cqe->bits_type_ts;
}

/*
 * Return a ptr to the next read wr in the SWSQ or NULL.
 */
static void advance_oldest_read(struct t4_wq *wq)
{

    u32 rptr = wq->sq.oldest_read - wq->sq.sw_sq + 1;

    if (rptr == wq->sq.size)
        rptr = 0;
    while (rptr != wq->sq.pidx) {
        wq->sq.oldest_read = &wq->sq.sw_sq[rptr];

        if (wq->sq.oldest_read->opcode == FW_RI_READ_REQ)
            return;
        if (++rptr == wq->sq.size)
            rptr = 0;
    }
    wq->sq.oldest_read = NULL;
}

/*
 * poll_cq
 *
 * Caller must:
 *     check the validity of the first CQE,
 *     supply the wq assicated with the qpid.
 *
 * credit: cq credit to return to sge.
 * cqe_flushed: 1 iff the CQE is flushed.
 * cqe: copy of the polled CQE.
 *
 * return value:
 *    0         CQE returned ok.
 *    -EAGAIN       CQE skipped, try again.
 *    -EOVERFLOW    CQ overflow detected.
 */
static int poll_cq(struct t4_wq *wq, struct t4_cq *cq, struct t4_cqe *cqe,
           u8 *cqe_flushed, u64 *cookie, u32 *credit)
{
    int ret = 0;
    struct t4_cqe *hw_cqe, read_cqe;

    *cqe_flushed = 0;
    *credit = 0;
    ret = t4_next_cqe(cq, &hw_cqe);
    if (ret)
        return ret;

    PDBG("%s CQE OVF %u qpid 0x%0x genbit %u type %u status 0x%0x"
         " opcode 0x%0x len 0x%0x wrid_hi_stag 0x%x wrid_low_msn 0x%x\n",
         __func__, CQE_OVFBIT(hw_cqe), CQE_QPID(hw_cqe),
         CQE_GENBIT(hw_cqe), CQE_TYPE(hw_cqe), CQE_STATUS(hw_cqe),
         CQE_OPCODE(hw_cqe), CQE_LEN(hw_cqe), CQE_WRID_HI(hw_cqe),
         CQE_WRID_LOW(hw_cqe));

    /*
     * skip cqe's not affiliated with a QP.
     */
    if (wq == NULL) {
        ret = -EAGAIN;
        goto skip_cqe;
    }

    /*
     * Gotta tweak READ completions:
     *  1) the cqe doesn't contain the sq_wptr from the wr.
     *  2) opcode not reflected from the wr.
     *  3) read_len not reflected from the wr.
     *  4) cq_type is RQ_TYPE not SQ_TYPE.
     */
    if (RQ_TYPE(hw_cqe) && (CQE_OPCODE(hw_cqe) == FW_RI_READ_RESP)) {

        /*
         * If this is an unsolicited read response, then the read
         * was generated by the kernel driver as part of peer-2-peer
         * connection setup.  So ignore the completion.
         */
        if (!wq->sq.oldest_read) {
            if (CQE_STATUS(hw_cqe))
                t4_set_wq_in_error(wq);
            ret = -EAGAIN;
            goto skip_cqe;
        }

        /*
         * Don't write to the HWCQ, so create a new read req CQE
         * in local memory.
         */
        create_read_req_cqe(wq, hw_cqe, &read_cqe);
        hw_cqe = &read_cqe;
        advance_oldest_read(wq);
    }

    if (CQE_STATUS(hw_cqe) || t4_wq_in_error(wq)) {
        *cqe_flushed = t4_wq_in_error(wq);
        t4_set_wq_in_error(wq);
        goto proc_cqe;
    }

    if (CQE_OPCODE(hw_cqe) == FW_RI_TERMINATE) {
        ret = -EAGAIN;
        goto skip_cqe;
    }

    /*
     * RECV completion.
     */
    if (RQ_TYPE(hw_cqe)) {

        /*
         * HW only validates 4 bits of MSN.  So we must validate that
         * the MSN in the SEND is the next expected MSN.  If its not,
         * then we complete this with T4_ERR_MSN and mark the wq in
         * error.
         */

        if (t4_rq_empty(wq)) {
            t4_set_wq_in_error(wq);
            ret = -EAGAIN;
            goto skip_cqe;
        }
        if (unlikely((CQE_WRID_MSN(hw_cqe) != (wq->rq.msn)))) {
            t4_set_wq_in_error(wq);
            hw_cqe->header |= htonl(V_CQE_STATUS(T4_ERR_MSN));
            goto proc_cqe;
        }
        goto proc_cqe;
    }

    /*
     * If we get here its a send completion.
     *
     * Handle out of order completion. These get stuffed
     * in the SW SQ. Then the SW SQ is walked to move any
     * now in-order completions into the SW CQ.  This handles
     * 2 cases:
     *  1) reaping unsignaled WRs when the first subsequent
     *     signaled WR is completed.
     *  2) out of order read completions.
     */
    if (!SW_CQE(hw_cqe) && (CQE_WRID_SQ_IDX(hw_cqe) != wq->sq.cidx)) {
        struct t4_swsqe *swsqe;

        PDBG("%s out of order completion going in sw_sq at idx %u\n",
             __func__, CQE_WRID_SQ_IDX(hw_cqe));
        swsqe = &wq->sq.sw_sq[CQE_WRID_SQ_IDX(hw_cqe)];
        swsqe->cqe = *hw_cqe;
        swsqe->complete = 1;
        ret = -EAGAIN;
        goto flush_wq;
    }

proc_cqe:
    *cqe = *hw_cqe;

    /*
     * Reap the associated WR(s) that are freed up with this
     * completion.
     */
    if (SQ_TYPE(hw_cqe)) {
        wq->sq.cidx = CQE_WRID_SQ_IDX(hw_cqe);
        PDBG("%s completing sq idx %u\n", __func__, wq->sq.cidx);
        *cookie = wq->sq.sw_sq[wq->sq.cidx].wr_id;
        t4_sq_consume(wq);
    } else {
        PDBG("%s completing rq idx %u\n", __func__, wq->rq.cidx);
        *cookie = wq->rq.sw_rq[wq->rq.cidx].wr_id;
        BUG_ON(t4_rq_empty(wq));
        t4_rq_consume(wq);
    }

flush_wq:
    /*
     * Flush any completed cqes that are now in-order.
     */
    flush_completed_wrs(wq, cq);

skip_cqe:
    if (SW_CQE(hw_cqe)) {
        PDBG("%s cq %p cqid 0x%x skip sw cqe cidx %u\n",
             __func__, cq, cq->cqid, cq->sw_cidx);
        t4_swcq_consume(cq);
    } else {
        PDBG("%s cq %p cqid 0x%x skip hw cqe cidx %u\n",
             __func__, cq, cq->cqid, cq->cidx);
        t4_hwcq_consume(cq);
    }
    return ret;
}

/*
 * Get one cq entry from c4iw and map it to openib.
 *
 * Returns:
 *  0           cqe returned
 *  -ENODATA        EMPTY;
 *  -EAGAIN         caller must try again
 *  any other -errno    fatal error
 */
static int c4iw_poll_cq_one(struct c4iw_cq *chp, struct ib_wc *wc)
{
    struct c4iw_qp *qhp = NULL;
    struct t4_cqe cqe = {0, 0}, *rd_cqe;
    struct t4_wq *wq;
    u32 credit = 0;
    u8 cqe_flushed;
    u64 cookie = 0;
    int ret;

    ret = t4_next_cqe(&chp->cq, &rd_cqe);

    if (ret)
        return ret;

    qhp = get_qhp(chp->rhp, CQE_QPID(rd_cqe));
    if (!qhp)
        wq = NULL;
    else {
        spin_lock(&qhp->lock);
        wq = &(qhp->wq);
    }
    ret = poll_cq(wq, &(chp->cq), &cqe, &cqe_flushed, &cookie, &credit);
    if (ret)
        goto out;

    wc->wr_id = cookie;
    wc->qp = &qhp->ibqp;
    wc->vendor_err = CQE_STATUS(&cqe);
    wc->wc_flags = 0;

    PDBG("%s qpid 0x%x type %d opcode %d status 0x%x len %u wrid hi 0x%x "
         "lo 0x%x cookie 0x%llx\n", __func__, CQE_QPID(&cqe),
         CQE_TYPE(&cqe), CQE_OPCODE(&cqe), CQE_STATUS(&cqe), CQE_LEN(&cqe),
         CQE_WRID_HI(&cqe), CQE_WRID_LOW(&cqe), (unsigned long long)cookie);

    if (CQE_TYPE(&cqe) == 0) {
        if (!CQE_STATUS(&cqe))
            wc->byte_len = CQE_LEN(&cqe);
        else
            wc->byte_len = 0;
        wc->opcode = IB_WC_RECV;
        if (CQE_OPCODE(&cqe) == FW_RI_SEND_WITH_INV ||
            CQE_OPCODE(&cqe) == FW_RI_SEND_WITH_SE_INV) {
            wc->ex.invalidate_rkey = CQE_WRID_STAG(&cqe);
            wc->wc_flags |= IB_WC_WITH_INVALIDATE;
        }
    } else {
        switch (CQE_OPCODE(&cqe)) {
        case FW_RI_RDMA_WRITE:
            wc->opcode = IB_WC_RDMA_WRITE;
            break;
        case FW_RI_READ_REQ:
            wc->opcode = IB_WC_RDMA_READ;
            wc->byte_len = CQE_LEN(&cqe);
            break;
        case FW_RI_SEND_WITH_INV:
        case FW_RI_SEND_WITH_SE_INV:
            wc->opcode = IB_WC_SEND;
            wc->wc_flags |= IB_WC_WITH_INVALIDATE;
            break;
        case FW_RI_SEND:
        case FW_RI_SEND_WITH_SE:
            wc->opcode = IB_WC_SEND;
            break;
        case FW_RI_BIND_MW:
            wc->opcode = IB_WC_BIND_MW;
            break;

        case FW_RI_LOCAL_INV:
            wc->opcode = IB_WC_LOCAL_INV;
            break;
        case FW_RI_FAST_REGISTER:
            wc->opcode = IB_WC_FAST_REG_MR;
            break;
        default:
            printk(KERN_ERR MOD "Unexpected opcode %d "
                   "in the CQE received for QPID=0x%0x\n",
                   CQE_OPCODE(&cqe), CQE_QPID(&cqe));
            ret = -EINVAL;
            goto out;
        }
    }

    if (cqe_flushed)
        wc->status = IB_WC_WR_FLUSH_ERR;
    else {

        switch (CQE_STATUS(&cqe)) {
        case T4_ERR_SUCCESS:
            wc->status = IB_WC_SUCCESS;
            break;
        case T4_ERR_STAG:
            wc->status = IB_WC_LOC_ACCESS_ERR;
            break;
        case T4_ERR_PDID:
            wc->status = IB_WC_LOC_PROT_ERR;
            break;
        case T4_ERR_QPID:
        case T4_ERR_ACCESS:
            wc->status = IB_WC_LOC_ACCESS_ERR;
            break;
        case T4_ERR_WRAP:
            wc->status = IB_WC_GENERAL_ERR;
            break;
        case T4_ERR_BOUND:
            wc->status = IB_WC_LOC_LEN_ERR;
            break;
        case T4_ERR_INVALIDATE_SHARED_MR:
        case T4_ERR_INVALIDATE_MR_WITH_MW_BOUND:
            wc->status = IB_WC_MW_BIND_ERR;
            break;
        case T4_ERR_CRC:
        case T4_ERR_MARKER:
        case T4_ERR_PDU_LEN_ERR:
        case T4_ERR_OUT_OF_RQE:
        case T4_ERR_DDP_VERSION:
        case T4_ERR_RDMA_VERSION:
        case T4_ERR_DDP_QUEUE_NUM:
        case T4_ERR_MSN:
        case T4_ERR_TBIT:
        case T4_ERR_MO:
        case T4_ERR_MSN_RANGE:
        case T4_ERR_IRD_OVERFLOW:
        case T4_ERR_OPCODE:
        case T4_ERR_INTERNAL_ERR:
            wc->status = IB_WC_FATAL_ERR;
            break;
        case T4_ERR_SWFLUSH:
            wc->status = IB_WC_WR_FLUSH_ERR;
            break;
        default:
            printk(KERN_ERR MOD
                   "Unexpected cqe_status 0x%x for QPID=0x%0x\n",
                   CQE_STATUS(&cqe), CQE_QPID(&cqe));
            ret = -EINVAL;
        }
    }
out:
    if (wq)
        spin_unlock(&qhp->lock);
    return ret;
}

int c4iw_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
{
    struct c4iw_cq *chp;
    unsigned long flags;
    int npolled;
    int err = 0;

    chp = to_c4iw_cq(ibcq);

    spin_lock_irqsave(&chp->lock, flags);
    for (npolled = 0; npolled < num_entries; ++npolled) {
        do {
            err = c4iw_poll_cq_one(chp, wc + npolled);
        } while (err == -EAGAIN);
        if (err)
            break;
    }
    spin_unlock_irqrestore(&chp->lock, flags);
    return !err || err == -ENODATA ? npolled : err;
}

int c4iw_destroy_cq(struct ib_cq *ib_cq)
{
    struct c4iw_cq *chp;
    struct c4iw_ucontext *ucontext;

    PDBG("%s ib_cq %p\n", __func__, ib_cq);
    chp = to_c4iw_cq(ib_cq);

    remove_handle(chp->rhp, &chp->rhp->cqidr, chp->cq.cqid);
    atomic_dec(&chp->refcnt);
    wait_event(chp->wait, !atomic_read(&chp->refcnt));

    ucontext = ib_cq->uobject ? to_c4iw_ucontext(ib_cq->uobject->context)
                  : NULL;
    destroy_cq(&chp->rhp->rdev, &chp->cq,
           ucontext ? &ucontext->uctx : &chp->cq.rdev->uctx);
    kfree(chp);
    return 0;
}

struct ib_cq *c4iw_create_cq(struct ib_device *ibdev, int entries,
                 int vector, struct ib_ucontext *ib_context,
                 struct ib_udata *udata)
{
    struct c4iw_dev *rhp;
    struct c4iw_cq *chp;
    struct c4iw_create_cq_resp uresp;
    struct c4iw_ucontext *ucontext = NULL;
    int ret;
    size_t memsize, hwentries;
    struct c4iw_mm_entry *mm, *mm2;

    PDBG("%s ib_dev %p entries %d\n", __func__, ibdev, entries);

    rhp = to_c4iw_dev(ibdev);

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

    if (ib_context)
        ucontext = to_c4iw_ucontext(ib_context);

    /* account for the status page. */
    entries++;

    /* IQ needs one extra entry to differentiate full vs empty. */
    entries++;

    /*
     * entries must be multiple of 16 for HW.
     */
    entries = roundup(entries, 16);

    /*
     * Make actual HW queue 2x to avoid cdix_inc overflows.
     */
    hwentries = entries * 2;

    /*
     * Make HW queue at least 64 entries so GTS updates aren't too
     * frequent.
     */
    if (hwentries < 64)
        hwentries = 64;

    memsize = hwentries * sizeof *chp->cq.queue;

    /*
     * memsize must be a multiple of the page size if its a user cq.
     */
    if (ucontext) {
        memsize = roundup(memsize, PAGE_SIZE);
        hwentries = memsize / sizeof *chp->cq.queue;
        while (hwentries > T4_MAX_IQ_SIZE) {
            memsize -= PAGE_SIZE;
            hwentries = memsize / sizeof *chp->cq.queue;
        }
    }
    chp->cq.size = hwentries;
    chp->cq.memsize = memsize;

    ret = create_cq(&rhp->rdev, &chp->cq,
            ucontext ? &ucontext->uctx : &rhp->rdev.uctx);
    if (ret)
        goto err1;

    chp->rhp = rhp;
    chp->cq.size--;             /* status page */
    chp->ibcq.cqe = entries - 2;
    spin_lock_init(&chp->lock);
    spin_lock_init(&chp->comp_handler_lock);
    atomic_set(&chp->refcnt, 1);
    init_waitqueue_head(&chp->wait);
    ret = insert_handle(rhp, &rhp->cqidr, chp, chp->cq.cqid);
    if (ret)
        goto err2;

    if (ucontext) {
        mm = kmalloc(sizeof *mm, GFP_KERNEL);
        if (!mm)
            goto err3;
        mm2 = kmalloc(sizeof *mm2, GFP_KERNEL);
        if (!mm2)
            goto err4;

        uresp.qid_mask = rhp->rdev.cqmask;
        uresp.cqid = chp->cq.cqid;
        uresp.size = chp->cq.size;
        uresp.memsize = chp->cq.memsize;
        spin_lock(&ucontext->mmap_lock);
        uresp.key = ucontext->key;
        ucontext->key += PAGE_SIZE;
        uresp.gts_key = ucontext->key;
        ucontext->key += PAGE_SIZE;
        spin_unlock(&ucontext->mmap_lock);
        ret = ib_copy_to_udata(udata, &uresp, sizeof uresp);
        if (ret)
            goto err5;

        mm->key = uresp.key;
        mm->addr = virt_to_phys(chp->cq.queue);
        mm->len = chp->cq.memsize;
        insert_mmap(ucontext, mm);

        mm2->key = uresp.gts_key;
        mm2->addr = chp->cq.ugts;
        mm2->len = PAGE_SIZE;
        insert_mmap(ucontext, mm2);
    }
    PDBG("%s cqid 0x%0x chp %p size %u memsize %zu, dma_addr 0x%0llx\n",
         __func__, chp->cq.cqid, chp, chp->cq.size,
         chp->cq.memsize,
         (unsigned long long) chp->cq.dma_addr);
    return &chp->ibcq;
err5:
    kfree(mm2);
err4:
    kfree(mm);
err3:
    remove_handle(rhp, &rhp->cqidr, chp->cq.cqid);
err2:
    destroy_cq(&chp->rhp->rdev, &chp->cq,
           ucontext ? &ucontext->uctx : &rhp->rdev.uctx);
err1:
    kfree(chp);
    return ERR_PTR(ret);
}

int c4iw_resize_cq(struct ib_cq *cq, int cqe, struct ib_udata *udata)
{
    return -ENOSYS;
}

int c4iw_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags)
{
    struct c4iw_cq *chp;
    int ret;
    unsigned long flag;

    chp = to_c4iw_cq(ibcq);
    spin_lock_irqsave(&chp->lock, flag);
    ret = t4_arm_cq(&chp->cq,
            (flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED);
    spin_unlock_irqrestore(&chp->lock, flag);
    if (ret && !(flags & IB_CQ_REPORT_MISSED_EVENTS))
        ret = 0;
    return ret;
}