mthca_cq.c

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/*
 * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 * Copyright (c) 2005, 2006 Cisco Systems, Inc. All rights reserved.
 * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
 * Copyright (c) 2004 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/gfp.h>
#include <linux/hardirq.h>
#include <linux/sched.h>

#include <asm/io.h>

#include <rdma/ib_pack.h>

#include "mthca_dev.h"
#include "mthca_cmd.h"
#include "mthca_memfree.h"

enum {
    MTHCA_MAX_DIRECT_CQ_SIZE = 4 * PAGE_SIZE
};

enum {
    MTHCA_CQ_ENTRY_SIZE = 0x20
};

enum {
    MTHCA_ATOMIC_BYTE_LEN = 8
};

/*
 * Must be packed because start is 64 bits but only aligned to 32 bits.
 */
struct mthca_cq_context {
    __be32 flags;
    __be64 start;
    __be32 logsize_usrpage;
    __be32 error_eqn;   /* Tavor only */
    __be32 comp_eqn;
    __be32 pd;
    __be32 lkey;
    __be32 last_notified_index;
    __be32 solicit_producer_index;
    __be32 consumer_index;
    __be32 producer_index;
    __be32 cqn;
    __be32 ci_db;       /* Arbel only */
    __be32 state_db;    /* Arbel only */
    u32    reserved;
} __attribute__((packed));

#define MTHCA_CQ_STATUS_OK          ( 0 << 28)
#define MTHCA_CQ_STATUS_OVERFLOW    ( 9 << 28)
#define MTHCA_CQ_STATUS_WRITE_FAIL  (10 << 28)
#define MTHCA_CQ_FLAG_TR            ( 1 << 18)
#define MTHCA_CQ_FLAG_OI            ( 1 << 17)
#define MTHCA_CQ_STATE_DISARMED     ( 0 <<  8)
#define MTHCA_CQ_STATE_ARMED        ( 1 <<  8)
#define MTHCA_CQ_STATE_ARMED_SOL    ( 4 <<  8)
#define MTHCA_EQ_STATE_FIRED        (10 <<  8)

enum {
    MTHCA_ERROR_CQE_OPCODE_MASK = 0xfe
};

enum {
    SYNDROME_LOCAL_LENGTH_ERR    = 0x01,
    SYNDROME_LOCAL_QP_OP_ERR     = 0x02,
    SYNDROME_LOCAL_EEC_OP_ERR    = 0x03,
    SYNDROME_LOCAL_PROT_ERR      = 0x04,
    SYNDROME_WR_FLUSH_ERR        = 0x05,
    SYNDROME_MW_BIND_ERR         = 0x06,
    SYNDROME_BAD_RESP_ERR        = 0x10,
    SYNDROME_LOCAL_ACCESS_ERR    = 0x11,
    SYNDROME_REMOTE_INVAL_REQ_ERR    = 0x12,
    SYNDROME_REMOTE_ACCESS_ERR   = 0x13,
    SYNDROME_REMOTE_OP_ERR       = 0x14,
    SYNDROME_RETRY_EXC_ERR       = 0x15,
    SYNDROME_RNR_RETRY_EXC_ERR   = 0x16,
    SYNDROME_LOCAL_RDD_VIOL_ERR      = 0x20,
    SYNDROME_REMOTE_INVAL_RD_REQ_ERR = 0x21,
    SYNDROME_REMOTE_ABORTED_ERR      = 0x22,
    SYNDROME_INVAL_EECN_ERR      = 0x23,
    SYNDROME_INVAL_EEC_STATE_ERR     = 0x24
};

struct mthca_cqe {
    __be32 my_qpn;
    __be32 my_ee;
    __be32 rqpn;
    u8     sl_ipok;
    u8     g_mlpath;
    __be16 rlid;
    __be32 imm_etype_pkey_eec;
    __be32 byte_cnt;
    __be32 wqe;
    u8     opcode;
    u8     is_send;
    u8     reserved;
    u8     owner;
};

struct mthca_err_cqe {
    __be32 my_qpn;
    u32    reserved1[3];
    u8     syndrome;
    u8     vendor_err;
    __be16 db_cnt;
    u32    reserved2;
    __be32 wqe;
    u8     opcode;
    u8     reserved3[2];
    u8     owner;
};

#define MTHCA_CQ_ENTRY_OWNER_SW      (0 << 7)
#define MTHCA_CQ_ENTRY_OWNER_HW      (1 << 7)

#define MTHCA_TAVOR_CQ_DB_INC_CI       (1 << 24)
#define MTHCA_TAVOR_CQ_DB_REQ_NOT      (2 << 24)
#define MTHCA_TAVOR_CQ_DB_REQ_NOT_SOL  (3 << 24)
#define MTHCA_TAVOR_CQ_DB_SET_CI       (4 << 24)
#define MTHCA_TAVOR_CQ_DB_REQ_NOT_MULT (5 << 24)

#define MTHCA_ARBEL_CQ_DB_REQ_NOT_SOL  (1 << 24)
#define MTHCA_ARBEL_CQ_DB_REQ_NOT      (2 << 24)
#define MTHCA_ARBEL_CQ_DB_REQ_NOT_MULT (3 << 24)

static inline struct mthca_cqe *get_cqe_from_buf(struct mthca_cq_buf *buf,
                         int entry)
{
    if (buf->is_direct)
        return buf->queue.direct.buf + (entry * MTHCA_CQ_ENTRY_SIZE);
    else
        return buf->queue.page_list[entry * MTHCA_CQ_ENTRY_SIZE / PAGE_SIZE].buf
            + (entry * MTHCA_CQ_ENTRY_SIZE) % PAGE_SIZE;
}

static inline struct mthca_cqe *get_cqe(struct mthca_cq *cq, int entry)
{
    return get_cqe_from_buf(&cq->buf, entry);
}

static inline struct mthca_cqe *cqe_sw(struct mthca_cqe *cqe)
{
    return MTHCA_CQ_ENTRY_OWNER_HW & cqe->owner ? NULL : cqe;
}

static inline struct mthca_cqe *next_cqe_sw(struct mthca_cq *cq)
{
    return cqe_sw(get_cqe(cq, cq->cons_index & cq->ibcq.cqe));
}

static inline void set_cqe_hw(struct mthca_cqe *cqe)
{
    cqe->owner = MTHCA_CQ_ENTRY_OWNER_HW;
}

static void dump_cqe(struct mthca_dev *dev, void *cqe_ptr)
{
    __be32 *cqe = cqe_ptr;

    (void) cqe; /* avoid warning if mthca_dbg compiled away... */
    mthca_dbg(dev, "CQE contents %08x %08x %08x %08x %08x %08x %08x %08x\n",
          be32_to_cpu(cqe[0]), be32_to_cpu(cqe[1]), be32_to_cpu(cqe[2]),
          be32_to_cpu(cqe[3]), be32_to_cpu(cqe[4]), be32_to_cpu(cqe[5]),
          be32_to_cpu(cqe[6]), be32_to_cpu(cqe[7]));
}

/*
 * incr is ignored in native Arbel (mem-free) mode, so cq->cons_index
 * should be correct before calling update_cons_index().
 */
static inline void update_cons_index(struct mthca_dev *dev, struct mthca_cq *cq,
                     int incr)
{
    if (mthca_is_memfree(dev)) {
        *cq->set_ci_db = cpu_to_be32(cq->cons_index);
        wmb();
    } else {
        mthca_write64(MTHCA_TAVOR_CQ_DB_INC_CI | cq->cqn, incr - 1,
                  dev->kar + MTHCA_CQ_DOORBELL,
                  MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
        /*
         * Make sure doorbells don't leak out of CQ spinlock
         * and reach the HCA out of order:
         */
        mmiowb();
    }
}

void mthca_cq_completion(struct mthca_dev *dev, u32 cqn)
{
    struct mthca_cq *cq;

    cq = mthca_array_get(&dev->cq_table.cq, cqn & (dev->limits.num_cqs - 1));

    if (!cq) {
        mthca_warn(dev, "Completion event for bogus CQ %08x\n", cqn);
        return;
    }

    ++cq->arm_sn;

    cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
}

void mthca_cq_event(struct mthca_dev *dev, u32 cqn,
            enum ib_event_type event_type)
{
    struct mthca_cq *cq;
    struct ib_event event;

    spin_lock(&dev->cq_table.lock);

    cq = mthca_array_get(&dev->cq_table.cq, cqn & (dev->limits.num_cqs - 1));
    if (cq)
        ++cq->refcount;

    spin_unlock(&dev->cq_table.lock);

    if (!cq) {
        mthca_warn(dev, "Async event for bogus CQ %08x\n", cqn);
        return;
    }

    event.device      = &dev->ib_dev;
    event.event       = event_type;
    event.element.cq  = &cq->ibcq;
    if (cq->ibcq.event_handler)
        cq->ibcq.event_handler(&event, cq->ibcq.cq_context);

    spin_lock(&dev->cq_table.lock);
    if (!--cq->refcount)
        wake_up(&cq->wait);
    spin_unlock(&dev->cq_table.lock);
}

static inline int is_recv_cqe(struct mthca_cqe *cqe)
{
    if ((cqe->opcode & MTHCA_ERROR_CQE_OPCODE_MASK) ==
        MTHCA_ERROR_CQE_OPCODE_MASK)
        return !(cqe->opcode & 0x01);
    else
        return !(cqe->is_send & 0x80);
}

void mthca_cq_clean(struct mthca_dev *dev, struct mthca_cq *cq, u32 qpn,
            struct mthca_srq *srq)
{
    struct mthca_cqe *cqe;
    u32 prod_index;
    int i, nfreed = 0;

    spin_lock_irq(&cq->lock);

    /*
     * First we need to find the current producer index, so we
     * know where to start cleaning from.  It doesn't matter if HW
     * adds new entries after this loop -- the QP we're worried
     * about is already in RESET, so the new entries won't come
     * from our QP and therefore don't need to be checked.
     */
    for (prod_index = cq->cons_index;
         cqe_sw(get_cqe(cq, prod_index & cq->ibcq.cqe));
         ++prod_index)
        if (prod_index == cq->cons_index + cq->ibcq.cqe)
            break;

    if (0)
        mthca_dbg(dev, "Cleaning QPN %06x from CQN %06x; ci %d, pi %d\n",
              qpn, cq->cqn, cq->cons_index, prod_index);

    /*
     * Now sweep backwards through the CQ, removing CQ entries
     * that match our QP by copying older entries on top of them.
     */
    while ((int) --prod_index - (int) cq->cons_index >= 0) {
        cqe = get_cqe(cq, prod_index & cq->ibcq.cqe);
        if (cqe->my_qpn == cpu_to_be32(qpn)) {
            if (srq && is_recv_cqe(cqe))
                mthca_free_srq_wqe(srq, be32_to_cpu(cqe->wqe));
            ++nfreed;
        } else if (nfreed)
            memcpy(get_cqe(cq, (prod_index + nfreed) & cq->ibcq.cqe),
                   cqe, MTHCA_CQ_ENTRY_SIZE);
    }

    if (nfreed) {
        for (i = 0; i < nfreed; ++i)
            set_cqe_hw(get_cqe(cq, (cq->cons_index + i) & cq->ibcq.cqe));
        wmb();
        cq->cons_index += nfreed;
        update_cons_index(dev, cq, nfreed);
    }

    spin_unlock_irq(&cq->lock);
}

void mthca_cq_resize_copy_cqes(struct mthca_cq *cq)
{
    int i;

    /*
     * In Tavor mode, the hardware keeps the consumer and producer
     * indices mod the CQ size.  Since we might be making the CQ
     * bigger, we need to deal with the case where the producer
     * index wrapped around before the CQ was resized.
     */
    if (!mthca_is_memfree(to_mdev(cq->ibcq.device)) &&
        cq->ibcq.cqe < cq->resize_buf->cqe) {
        cq->cons_index &= cq->ibcq.cqe;
        if (cqe_sw(get_cqe(cq, cq->ibcq.cqe)))
            cq->cons_index -= cq->ibcq.cqe + 1;
    }

    for (i = cq->cons_index; cqe_sw(get_cqe(cq, i & cq->ibcq.cqe)); ++i)
        memcpy(get_cqe_from_buf(&cq->resize_buf->buf,
                    i & cq->resize_buf->cqe),
               get_cqe(cq, i & cq->ibcq.cqe), MTHCA_CQ_ENTRY_SIZE);
}

int mthca_alloc_cq_buf(struct mthca_dev *dev, struct mthca_cq_buf *buf, int nent)
{
    int ret;
    int i;

    ret = mthca_buf_alloc(dev, nent * MTHCA_CQ_ENTRY_SIZE,
                  MTHCA_MAX_DIRECT_CQ_SIZE,
                  &buf->queue, &buf->is_direct,
                  &dev->driver_pd, 1, &buf->mr);
    if (ret)
        return ret;

    for (i = 0; i < nent; ++i)
        set_cqe_hw(get_cqe_from_buf(buf, i));

    return 0;
}

void mthca_free_cq_buf(struct mthca_dev *dev, struct mthca_cq_buf *buf, int cqe)
{
    mthca_buf_free(dev, (cqe + 1) * MTHCA_CQ_ENTRY_SIZE, &buf->queue,
               buf->is_direct, &buf->mr);
}

static void handle_error_cqe(struct mthca_dev *dev, struct mthca_cq *cq,
                 struct mthca_qp *qp, int wqe_index, int is_send,
                 struct mthca_err_cqe *cqe,
                 struct ib_wc *entry, int *free_cqe)
{
    int dbd;
    __be32 new_wqe;

    if (cqe->syndrome == SYNDROME_LOCAL_QP_OP_ERR) {
        mthca_dbg(dev, "local QP operation err "
              "(QPN %06x, WQE @ %08x, CQN %06x, index %d)\n",
              be32_to_cpu(cqe->my_qpn), be32_to_cpu(cqe->wqe),
              cq->cqn, cq->cons_index);
        dump_cqe(dev, cqe);
    }

    /*
     * For completions in error, only work request ID, status, vendor error
     * (and freed resource count for RD) have to be set.
     */
    switch (cqe->syndrome) {
    case SYNDROME_LOCAL_LENGTH_ERR:
        entry->status = IB_WC_LOC_LEN_ERR;
        break;
    case SYNDROME_LOCAL_QP_OP_ERR:
        entry->status = IB_WC_LOC_QP_OP_ERR;
        break;
    case SYNDROME_LOCAL_EEC_OP_ERR:
        entry->status = IB_WC_LOC_EEC_OP_ERR;
        break;
    case SYNDROME_LOCAL_PROT_ERR:
        entry->status = IB_WC_LOC_PROT_ERR;
        break;
    case SYNDROME_WR_FLUSH_ERR:
        entry->status = IB_WC_WR_FLUSH_ERR;
        break;
    case SYNDROME_MW_BIND_ERR:
        entry->status = IB_WC_MW_BIND_ERR;
        break;
    case SYNDROME_BAD_RESP_ERR:
        entry->status = IB_WC_BAD_RESP_ERR;
        break;
    case SYNDROME_LOCAL_ACCESS_ERR:
        entry->status = IB_WC_LOC_ACCESS_ERR;
        break;
    case SYNDROME_REMOTE_INVAL_REQ_ERR:
        entry->status = IB_WC_REM_INV_REQ_ERR;
        break;
    case SYNDROME_REMOTE_ACCESS_ERR:
        entry->status = IB_WC_REM_ACCESS_ERR;
        break;
    case SYNDROME_REMOTE_OP_ERR:
        entry->status = IB_WC_REM_OP_ERR;
        break;
    case SYNDROME_RETRY_EXC_ERR:
        entry->status = IB_WC_RETRY_EXC_ERR;
        break;
    case SYNDROME_RNR_RETRY_EXC_ERR:
        entry->status = IB_WC_RNR_RETRY_EXC_ERR;
        break;
    case SYNDROME_LOCAL_RDD_VIOL_ERR:
        entry->status = IB_WC_LOC_RDD_VIOL_ERR;
        break;
    case SYNDROME_REMOTE_INVAL_RD_REQ_ERR:
        entry->status = IB_WC_REM_INV_RD_REQ_ERR;
        break;
    case SYNDROME_REMOTE_ABORTED_ERR:
        entry->status = IB_WC_REM_ABORT_ERR;
        break;
    case SYNDROME_INVAL_EECN_ERR:
        entry->status = IB_WC_INV_EECN_ERR;
        break;
    case SYNDROME_INVAL_EEC_STATE_ERR:
        entry->status = IB_WC_INV_EEC_STATE_ERR;
        break;
    default:
        entry->status = IB_WC_GENERAL_ERR;
        break;
    }

    entry->vendor_err = cqe->vendor_err;

    /*
     * Mem-free HCAs always generate one CQE per WQE, even in the
     * error case, so we don't have to check the doorbell count, etc.
     */
    if (mthca_is_memfree(dev))
        return;

    mthca_free_err_wqe(dev, qp, is_send, wqe_index, &dbd, &new_wqe);

    /*
     * If we're at the end of the WQE chain, or we've used up our
     * doorbell count, free the CQE.  Otherwise just update it for
     * the next poll operation.
     */
    if (!(new_wqe & cpu_to_be32(0x3f)) || (!cqe->db_cnt && dbd))
        return;

    be16_add_cpu(&cqe->db_cnt, -dbd);
    cqe->wqe      = new_wqe;
    cqe->syndrome = SYNDROME_WR_FLUSH_ERR;

    *free_cqe = 0;
}

static inline int mthca_poll_one(struct mthca_dev *dev,
                 struct mthca_cq *cq,
                 struct mthca_qp **cur_qp,
                 int *freed,
                 struct ib_wc *entry)
{
    struct mthca_wq *wq;
    struct mthca_cqe *cqe;
    int wqe_index;
    int is_error;
    int is_send;
    int free_cqe = 1;
    int err = 0;
    u16 checksum;

    cqe = next_cqe_sw(cq);
    if (!cqe)
        return -EAGAIN;

    /*
     * Make sure we read CQ entry contents after we've checked the
     * ownership bit.
     */
    rmb();

    if (0) {
        mthca_dbg(dev, "%x/%d: CQE -> QPN %06x, WQE @ %08x\n",
              cq->cqn, cq->cons_index, be32_to_cpu(cqe->my_qpn),
              be32_to_cpu(cqe->wqe));
        dump_cqe(dev, cqe);
    }

    is_error = (cqe->opcode & MTHCA_ERROR_CQE_OPCODE_MASK) ==
        MTHCA_ERROR_CQE_OPCODE_MASK;
    is_send  = is_error ? cqe->opcode & 0x01 : cqe->is_send & 0x80;

    if (!*cur_qp || be32_to_cpu(cqe->my_qpn) != (*cur_qp)->qpn) {
        /*
         * We do not have to take the QP table lock here,
         * because CQs will be locked while QPs are removed
         * from the table.
         */
        *cur_qp = mthca_array_get(&dev->qp_table.qp,
                      be32_to_cpu(cqe->my_qpn) &
                      (dev->limits.num_qps - 1));
        if (!*cur_qp) {
            mthca_warn(dev, "CQ entry for unknown QP %06x\n",
                   be32_to_cpu(cqe->my_qpn) & 0xffffff);
            err = -EINVAL;
            goto out;
        }
    }

    entry->qp = &(*cur_qp)->ibqp;

    if (is_send) {
        wq = &(*cur_qp)->sq;
        wqe_index = ((be32_to_cpu(cqe->wqe) - (*cur_qp)->send_wqe_offset)
                 >> wq->wqe_shift);
        entry->wr_id = (*cur_qp)->wrid[wqe_index +
                           (*cur_qp)->rq.max];
    } else if ((*cur_qp)->ibqp.srq) {
        struct mthca_srq *srq = to_msrq((*cur_qp)->ibqp.srq);
        u32 wqe = be32_to_cpu(cqe->wqe);
        wq = NULL;
        wqe_index = wqe >> srq->wqe_shift;
        entry->wr_id = srq->wrid[wqe_index];
        mthca_free_srq_wqe(srq, wqe);
    } else {
        s32 wqe;
        wq = &(*cur_qp)->rq;
        wqe = be32_to_cpu(cqe->wqe);
        wqe_index = wqe >> wq->wqe_shift;
        /*
         * WQE addr == base - 1 might be reported in receive completion
         * with error instead of (rq size - 1) by Sinai FW 1.0.800 and
         * Arbel FW 5.1.400.  This bug should be fixed in later FW revs.
         */
        if (unlikely(wqe_index < 0))
            wqe_index = wq->max - 1;
        entry->wr_id = (*cur_qp)->wrid[wqe_index];
    }

    if (wq) {
        if (wq->last_comp < wqe_index)
            wq->tail += wqe_index - wq->last_comp;
        else
            wq->tail += wqe_index + wq->max - wq->last_comp;

        wq->last_comp = wqe_index;
    }

    if (is_error) {
        handle_error_cqe(dev, cq, *cur_qp, wqe_index, is_send,
                 (struct mthca_err_cqe *) cqe,
                 entry, &free_cqe);
        goto out;
    }

    if (is_send) {
        entry->wc_flags = 0;
        switch (cqe->opcode) {
        case MTHCA_OPCODE_RDMA_WRITE:
            entry->opcode    = IB_WC_RDMA_WRITE;
            break;
        case MTHCA_OPCODE_RDMA_WRITE_IMM:
            entry->opcode    = IB_WC_RDMA_WRITE;
            entry->wc_flags |= IB_WC_WITH_IMM;
            break;
        case MTHCA_OPCODE_SEND:
            entry->opcode    = IB_WC_SEND;
            break;
        case MTHCA_OPCODE_SEND_IMM:
            entry->opcode    = IB_WC_SEND;
            entry->wc_flags |= IB_WC_WITH_IMM;
            break;
        case MTHCA_OPCODE_RDMA_READ:
            entry->opcode    = IB_WC_RDMA_READ;
            entry->byte_len  = be32_to_cpu(cqe->byte_cnt);
            break;
        case MTHCA_OPCODE_ATOMIC_CS:
            entry->opcode    = IB_WC_COMP_SWAP;
            entry->byte_len  = MTHCA_ATOMIC_BYTE_LEN;
            break;
        case MTHCA_OPCODE_ATOMIC_FA:
            entry->opcode    = IB_WC_FETCH_ADD;
            entry->byte_len  = MTHCA_ATOMIC_BYTE_LEN;
            break;
        case MTHCA_OPCODE_BIND_MW:
            entry->opcode    = IB_WC_BIND_MW;
            break;
        default:
            entry->opcode    = MTHCA_OPCODE_INVALID;
            break;
        }
    } else {
        entry->byte_len = be32_to_cpu(cqe->byte_cnt);
        switch (cqe->opcode & 0x1f) {
        case IB_OPCODE_SEND_LAST_WITH_IMMEDIATE:
        case IB_OPCODE_SEND_ONLY_WITH_IMMEDIATE:
            entry->wc_flags = IB_WC_WITH_IMM;
            entry->ex.imm_data = cqe->imm_etype_pkey_eec;
            entry->opcode = IB_WC_RECV;
            break;
        case IB_OPCODE_RDMA_WRITE_LAST_WITH_IMMEDIATE:
        case IB_OPCODE_RDMA_WRITE_ONLY_WITH_IMMEDIATE:
            entry->wc_flags = IB_WC_WITH_IMM;
            entry->ex.imm_data = cqe->imm_etype_pkey_eec;
            entry->opcode = IB_WC_RECV_RDMA_WITH_IMM;
            break;
        default:
            entry->wc_flags = 0;
            entry->opcode = IB_WC_RECV;
            break;
        }
        entry->slid        = be16_to_cpu(cqe->rlid);
        entry->sl          = cqe->sl_ipok >> 4;
        entry->src_qp      = be32_to_cpu(cqe->rqpn) & 0xffffff;
        entry->dlid_path_bits = cqe->g_mlpath & 0x7f;
        entry->pkey_index  = be32_to_cpu(cqe->imm_etype_pkey_eec) >> 16;
        entry->wc_flags   |= cqe->g_mlpath & 0x80 ? IB_WC_GRH : 0;
        checksum = (be32_to_cpu(cqe->rqpn) >> 24) |
                ((be32_to_cpu(cqe->my_ee) >> 16) & 0xff00);
        entry->wc_flags   |=  (cqe->sl_ipok & 1 && checksum == 0xffff) ?
                            IB_WC_IP_CSUM_OK : 0;
    }

    entry->status = IB_WC_SUCCESS;

 out:
    if (likely(free_cqe)) {
        set_cqe_hw(cqe);
        ++(*freed);
        ++cq->cons_index;
    }

    return err;
}

int mthca_poll_cq(struct ib_cq *ibcq, int num_entries,
          struct ib_wc *entry)
{
    struct mthca_dev *dev = to_mdev(ibcq->device);
    struct mthca_cq *cq = to_mcq(ibcq);
    struct mthca_qp *qp = NULL;
    unsigned long flags;
    int err = 0;
    int freed = 0;
    int npolled;

    spin_lock_irqsave(&cq->lock, flags);

    npolled = 0;
repoll:
    while (npolled < num_entries) {
        err = mthca_poll_one(dev, cq, &qp,
                     &freed, entry + npolled);
        if (err)
            break;
        ++npolled;
    }

    if (freed) {
        wmb();
        update_cons_index(dev, cq, freed);
    }

    /*
     * If a CQ resize is in progress and we discovered that the
     * old buffer is empty, then peek in the new buffer, and if
     * it's not empty, switch to the new buffer and continue
     * polling there.
     */
    if (unlikely(err == -EAGAIN && cq->resize_buf &&
             cq->resize_buf->state == CQ_RESIZE_READY)) {
        /*
         * In Tavor mode, the hardware keeps the producer
         * index modulo the CQ size.  Since we might be making
         * the CQ bigger, we need to mask our consumer index
         * using the size of the old CQ buffer before looking
         * in the new CQ buffer.
         */
        if (!mthca_is_memfree(dev))
            cq->cons_index &= cq->ibcq.cqe;

        if (cqe_sw(get_cqe_from_buf(&cq->resize_buf->buf,
                        cq->cons_index & cq->resize_buf->cqe))) {
            struct mthca_cq_buf tbuf;
            int tcqe;

            tbuf         = cq->buf;
            tcqe         = cq->ibcq.cqe;
            cq->buf      = cq->resize_buf->buf;
            cq->ibcq.cqe = cq->resize_buf->cqe;

            cq->resize_buf->buf   = tbuf;
            cq->resize_buf->cqe   = tcqe;
            cq->resize_buf->state = CQ_RESIZE_SWAPPED;

            goto repoll;
        }
    }

    spin_unlock_irqrestore(&cq->lock, flags);

    return err == 0 || err == -EAGAIN ? npolled : err;
}

int mthca_tavor_arm_cq(struct ib_cq *cq, enum ib_cq_notify_flags flags)
{
    u32 dbhi = ((flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED ?
            MTHCA_TAVOR_CQ_DB_REQ_NOT_SOL :
            MTHCA_TAVOR_CQ_DB_REQ_NOT) |
        to_mcq(cq)->cqn;

    mthca_write64(dbhi, 0xffffffff, to_mdev(cq->device)->kar + MTHCA_CQ_DOORBELL,
              MTHCA_GET_DOORBELL_LOCK(&to_mdev(cq->device)->doorbell_lock));

    return 0;
}

int mthca_arbel_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags)
{
    struct mthca_cq *cq = to_mcq(ibcq);
    __be32 db_rec[2];
    u32 dbhi;
    u32 sn = cq->arm_sn & 3;

    db_rec[0] = cpu_to_be32(cq->cons_index);
    db_rec[1] = cpu_to_be32((cq->cqn << 8) | (2 << 5) | (sn << 3) |
                ((flags & IB_CQ_SOLICITED_MASK) ==
                 IB_CQ_SOLICITED ? 1 : 2));

    mthca_write_db_rec(db_rec, cq->arm_db);

    /*
     * Make sure that the doorbell record in host memory is
     * written before ringing the doorbell via PCI MMIO.
     */
    wmb();

    dbhi = (sn << 28) |
        ((flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED ?
         MTHCA_ARBEL_CQ_DB_REQ_NOT_SOL :
         MTHCA_ARBEL_CQ_DB_REQ_NOT) | cq->cqn;

    mthca_write64(dbhi, cq->cons_index,
              to_mdev(ibcq->device)->kar + MTHCA_CQ_DOORBELL,
              MTHCA_GET_DOORBELL_LOCK(&to_mdev(ibcq->device)->doorbell_lock));

    return 0;
}

int mthca_init_cq(struct mthca_dev *dev, int nent,
          struct mthca_ucontext *ctx, u32 pdn,
          struct mthca_cq *cq)
{
    struct mthca_mailbox *mailbox;
    struct mthca_cq_context *cq_context;
    int err = -ENOMEM;

    cq->ibcq.cqe  = nent - 1;
    cq->is_kernel = !ctx;

    cq->cqn = mthca_alloc(&dev->cq_table.alloc);
    if (cq->cqn == -1)
        return -ENOMEM;

    if (mthca_is_memfree(dev)) {
        err = mthca_table_get(dev, dev->cq_table.table, cq->cqn);
        if (err)
            goto err_out;

        if (cq->is_kernel) {
            cq->arm_sn = 1;

            err = -ENOMEM;

            cq->set_ci_db_index = mthca_alloc_db(dev, MTHCA_DB_TYPE_CQ_SET_CI,
                                 cq->cqn, &cq->set_ci_db);
            if (cq->set_ci_db_index < 0)
                goto err_out_icm;

            cq->arm_db_index = mthca_alloc_db(dev, MTHCA_DB_TYPE_CQ_ARM,
                              cq->cqn, &cq->arm_db);
            if (cq->arm_db_index < 0)
                goto err_out_ci;
        }
    }

    mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
    if (IS_ERR(mailbox))
        goto err_out_arm;

    cq_context = mailbox->buf;

    if (cq->is_kernel) {
        err = mthca_alloc_cq_buf(dev, &cq->buf, nent);
        if (err)
            goto err_out_mailbox;
    }

    spin_lock_init(&cq->lock);
    cq->refcount = 1;
    init_waitqueue_head(&cq->wait);
    mutex_init(&cq->mutex);

    memset(cq_context, 0, sizeof *cq_context);
    cq_context->flags           = cpu_to_be32(MTHCA_CQ_STATUS_OK      |
                          MTHCA_CQ_STATE_DISARMED |
                          MTHCA_CQ_FLAG_TR);
    cq_context->logsize_usrpage = cpu_to_be32((ffs(nent) - 1) << 24);
    if (ctx)
        cq_context->logsize_usrpage |= cpu_to_be32(ctx->uar.index);
    else
        cq_context->logsize_usrpage |= cpu_to_be32(dev->driver_uar.index);
    cq_context->error_eqn       = cpu_to_be32(dev->eq_table.eq[MTHCA_EQ_ASYNC].eqn);
    cq_context->comp_eqn        = cpu_to_be32(dev->eq_table.eq[MTHCA_EQ_COMP].eqn);
    cq_context->pd              = cpu_to_be32(pdn);
    cq_context->lkey            = cpu_to_be32(cq->buf.mr.ibmr.lkey);
    cq_context->cqn             = cpu_to_be32(cq->cqn);

    if (mthca_is_memfree(dev)) {
        cq_context->ci_db    = cpu_to_be32(cq->set_ci_db_index);
        cq_context->state_db = cpu_to_be32(cq->arm_db_index);
    }

    err = mthca_SW2HW_CQ(dev, mailbox, cq->cqn);
    if (err) {
        mthca_warn(dev, "SW2HW_CQ failed (%d)\n", err);
        goto err_out_free_mr;
    }

    spin_lock_irq(&dev->cq_table.lock);
    if (mthca_array_set(&dev->cq_table.cq,
                cq->cqn & (dev->limits.num_cqs - 1),
                cq)) {
        spin_unlock_irq(&dev->cq_table.lock);
        goto err_out_free_mr;
    }
    spin_unlock_irq(&dev->cq_table.lock);

    cq->cons_index = 0;

    mthca_free_mailbox(dev, mailbox);

    return 0;

err_out_free_mr:
    if (cq->is_kernel)
        mthca_free_cq_buf(dev, &cq->buf, cq->ibcq.cqe);

err_out_mailbox:
    mthca_free_mailbox(dev, mailbox);

err_out_arm:
    if (cq->is_kernel && mthca_is_memfree(dev))
        mthca_free_db(dev, MTHCA_DB_TYPE_CQ_ARM, cq->arm_db_index);

err_out_ci:
    if (cq->is_kernel && mthca_is_memfree(dev))
        mthca_free_db(dev, MTHCA_DB_TYPE_CQ_SET_CI, cq->set_ci_db_index);

err_out_icm:
    mthca_table_put(dev, dev->cq_table.table, cq->cqn);

err_out:
    mthca_free(&dev->cq_table.alloc, cq->cqn);

    return err;
}

static inline int get_cq_refcount(struct mthca_dev *dev, struct mthca_cq *cq)
{
    int c;

    spin_lock_irq(&dev->cq_table.lock);
    c = cq->refcount;
    spin_unlock_irq(&dev->cq_table.lock);

    return c;
}

void mthca_free_cq(struct mthca_dev *dev,
           struct mthca_cq *cq)
{
    struct mthca_mailbox *mailbox;
    int err;

    mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
    if (IS_ERR(mailbox)) {
        mthca_warn(dev, "No memory for mailbox to free CQ.\n");
        return;
    }

    err = mthca_HW2SW_CQ(dev, mailbox, cq->cqn);
    if (err)
        mthca_warn(dev, "HW2SW_CQ failed (%d)\n", err);

    if (0) {
        __be32 *ctx = mailbox->buf;
        int j;

        printk(KERN_ERR "context for CQN %x (cons index %x, next sw %d)\n",
               cq->cqn, cq->cons_index,
               cq->is_kernel ? !!next_cqe_sw(cq) : 0);
        for (j = 0; j < 16; ++j)
            printk(KERN_ERR "[%2x] %08x\n", j * 4, be32_to_cpu(ctx[j]));
    }

    spin_lock_irq(&dev->cq_table.lock);
    mthca_array_clear(&dev->cq_table.cq,
              cq->cqn & (dev->limits.num_cqs - 1));
    --cq->refcount;
    spin_unlock_irq(&dev->cq_table.lock);

    if (dev->mthca_flags & MTHCA_FLAG_MSI_X)
        synchronize_irq(dev->eq_table.eq[MTHCA_EQ_COMP].msi_x_vector);
    else
        synchronize_irq(dev->pdev->irq);

    wait_event(cq->wait, !get_cq_refcount(dev, cq));

    if (cq->is_kernel) {
        mthca_free_cq_buf(dev, &cq->buf, cq->ibcq.cqe);
        if (mthca_is_memfree(dev)) {
            mthca_free_db(dev, MTHCA_DB_TYPE_CQ_ARM,    cq->arm_db_index);
            mthca_free_db(dev, MTHCA_DB_TYPE_CQ_SET_CI, cq->set_ci_db_index);
        }
    }

    mthca_table_put(dev, dev->cq_table.table, cq->cqn);
    mthca_free(&dev->cq_table.alloc, cq->cqn);
    mthca_free_mailbox(dev, mailbox);
}

int mthca_init_cq_table(struct mthca_dev *dev)
{
    int err;

    spin_lock_init(&dev->cq_table.lock);

    err = mthca_alloc_init(&dev->cq_table.alloc,
                   dev->limits.num_cqs,
                   (1 << 24) - 1,
                   dev->limits.reserved_cqs);
    if (err)
        return err;

    err = mthca_array_init(&dev->cq_table.cq,
                   dev->limits.num_cqs);
    if (err)
        mthca_alloc_cleanup(&dev->cq_table.alloc);

    return err;
}

void mthca_cleanup_cq_table(struct mthca_dev *dev)
{
    mthca_array_cleanup(&dev->cq_table.cq, dev->limits.num_cqs);
    mthca_alloc_cleanup(&dev->cq_table.alloc);
}