qib_ruc.c

Go to the documentation of this file.

/*
 * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
 * Copyright (c) 2005, 2006 PathScale, 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/spinlock.h>

#include "qib.h"
#include "qib_mad.h"

/*
 * Convert the AETH RNR timeout code into the number of microseconds.
 */
const u32 ib_qib_rnr_table[32] = {
    655360, /* 00: 655.36 */
    10, /* 01:    .01 */
    20, /* 02     .02 */
    30, /* 03:    .03 */
    40, /* 04:    .04 */
    60, /* 05:    .06 */
    80, /* 06:    .08 */
    120,    /* 07:    .12 */
    160,    /* 08:    .16 */
    240,    /* 09:    .24 */
    320,    /* 0A:    .32 */
    480,    /* 0B:    .48 */
    640,    /* 0C:    .64 */
    960,    /* 0D:    .96 */
    1280,   /* 0E:   1.28 */
    1920,   /* 0F:   1.92 */
    2560,   /* 10:   2.56 */
    3840,   /* 11:   3.84 */
    5120,   /* 12:   5.12 */
    7680,   /* 13:   7.68 */
    10240,  /* 14:  10.24 */
    15360,  /* 15:  15.36 */
    20480,  /* 16:  20.48 */
    30720,  /* 17:  30.72 */
    40960,  /* 18:  40.96 */
    61440,  /* 19:  61.44 */
    81920,  /* 1A:  81.92 */
    122880, /* 1B: 122.88 */
    163840, /* 1C: 163.84 */
    245760, /* 1D: 245.76 */
    327680, /* 1E: 327.68 */
    491520  /* 1F: 491.52 */
};

/*
 * Validate a RWQE and fill in the SGE state.
 * Return 1 if OK.
 */
static int qib_init_sge(struct qib_qp *qp, struct qib_rwqe *wqe)
{
    int i, j, ret;
    struct ib_wc wc;
    struct qib_lkey_table *rkt;
    struct qib_pd *pd;
    struct qib_sge_state *ss;

    rkt = &to_idev(qp->ibqp.device)->lk_table;
    pd = to_ipd(qp->ibqp.srq ? qp->ibqp.srq->pd : qp->ibqp.pd);
    ss = &qp->r_sge;
    ss->sg_list = qp->r_sg_list;
    qp->r_len = 0;
    for (i = j = 0; i < wqe->num_sge; i++) {
        if (wqe->sg_list[i].length == 0)
            continue;
        /* Check LKEY */
        if (!qib_lkey_ok(rkt, pd, j ? &ss->sg_list[j - 1] : &ss->sge,
                 &wqe->sg_list[i], IB_ACCESS_LOCAL_WRITE))
            goto bad_lkey;
        qp->r_len += wqe->sg_list[i].length;
        j++;
    }
    ss->num_sge = j;
    ss->total_len = qp->r_len;
    ret = 1;
    goto bail;

bad_lkey:
    while (j) {
        struct qib_sge *sge = --j ? &ss->sg_list[j - 1] : &ss->sge;

        qib_put_mr(sge->mr);
    }
    ss->num_sge = 0;
    memset(&wc, 0, sizeof(wc));
    wc.wr_id = wqe->wr_id;
    wc.status = IB_WC_LOC_PROT_ERR;
    wc.opcode = IB_WC_RECV;
    wc.qp = &qp->ibqp;
    /* Signal solicited completion event. */
    qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
    ret = 0;
bail:
    return ret;
}

int qib_get_rwqe(struct qib_qp *qp, int wr_id_only)
{
    unsigned long flags;
    struct qib_rq *rq;
    struct qib_rwq *wq;
    struct qib_srq *srq;
    struct qib_rwqe *wqe;
    void (*handler)(struct ib_event *, void *);
    u32 tail;
    int ret;

    if (qp->ibqp.srq) {
        srq = to_isrq(qp->ibqp.srq);
        handler = srq->ibsrq.event_handler;
        rq = &srq->rq;
    } else {
        srq = NULL;
        handler = NULL;
        rq = &qp->r_rq;
    }

    spin_lock_irqsave(&rq->lock, flags);
    if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) {
        ret = 0;
        goto unlock;
    }

    wq = rq->wq;
    tail = wq->tail;
    /* Validate tail before using it since it is user writable. */
    if (tail >= rq->size)
        tail = 0;
    if (unlikely(tail == wq->head)) {
        ret = 0;
        goto unlock;
    }
    /* Make sure entry is read after head index is read. */
    smp_rmb();
    wqe = get_rwqe_ptr(rq, tail);
    /*
     * Even though we update the tail index in memory, the verbs
     * consumer is not supposed to post more entries until a
     * completion is generated.
     */
    if (++tail >= rq->size)
        tail = 0;
    wq->tail = tail;
    if (!wr_id_only && !qib_init_sge(qp, wqe)) {
        ret = -1;
        goto unlock;
    }
    qp->r_wr_id = wqe->wr_id;

    ret = 1;
    set_bit(QIB_R_WRID_VALID, &qp->r_aflags);
    if (handler) {
        u32 n;

        /*
         * Validate head pointer value and compute
         * the number of remaining WQEs.
         */
        n = wq->head;
        if (n >= rq->size)
            n = 0;
        if (n < tail)
            n += rq->size - tail;
        else
            n -= tail;
        if (n < srq->limit) {
            struct ib_event ev;

            srq->limit = 0;
            spin_unlock_irqrestore(&rq->lock, flags);
            ev.device = qp->ibqp.device;
            ev.element.srq = qp->ibqp.srq;
            ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
            handler(&ev, srq->ibsrq.srq_context);
            goto bail;
        }
    }
unlock:
    spin_unlock_irqrestore(&rq->lock, flags);
bail:
    return ret;
}

/*
 * Switch to alternate path.
 * The QP s_lock should be held and interrupts disabled.
 */
void qib_migrate_qp(struct qib_qp *qp)
{
    struct ib_event ev;

    qp->s_mig_state = IB_MIG_MIGRATED;
    qp->remote_ah_attr = qp->alt_ah_attr;
    qp->port_num = qp->alt_ah_attr.port_num;
    qp->s_pkey_index = qp->s_alt_pkey_index;

    ev.device = qp->ibqp.device;
    ev.element.qp = &qp->ibqp;
    ev.event = IB_EVENT_PATH_MIG;
    qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
}

static __be64 get_sguid(struct qib_ibport *ibp, unsigned index)
{
    if (!index) {
        struct qib_pportdata *ppd = ppd_from_ibp(ibp);

        return ppd->guid;
    } else
        return ibp->guids[index - 1];
}

static int gid_ok(union ib_gid *gid, __be64 gid_prefix, __be64 id)
{
    return (gid->global.interface_id == id &&
        (gid->global.subnet_prefix == gid_prefix ||
         gid->global.subnet_prefix == IB_DEFAULT_GID_PREFIX));
}

/*
 *
 * This should be called with the QP r_lock held.
 *
 * The s_lock will be acquired around the qib_migrate_qp() call.
 */
int qib_ruc_check_hdr(struct qib_ibport *ibp, struct qib_ib_header *hdr,
              int has_grh, struct qib_qp *qp, u32 bth0)
{
    __be64 guid;
    unsigned long flags;

    if (qp->s_mig_state == IB_MIG_ARMED && (bth0 & IB_BTH_MIG_REQ)) {
        if (!has_grh) {
            if (qp->alt_ah_attr.ah_flags & IB_AH_GRH)
                goto err;
        } else {
            if (!(qp->alt_ah_attr.ah_flags & IB_AH_GRH))
                goto err;
            guid = get_sguid(ibp, qp->alt_ah_attr.grh.sgid_index);
            if (!gid_ok(&hdr->u.l.grh.dgid, ibp->gid_prefix, guid))
                goto err;
            if (!gid_ok(&hdr->u.l.grh.sgid,
                qp->alt_ah_attr.grh.dgid.global.subnet_prefix,
                qp->alt_ah_attr.grh.dgid.global.interface_id))
                goto err;
        }
        if (!qib_pkey_ok((u16)bth0,
                 qib_get_pkey(ibp, qp->s_alt_pkey_index))) {
            qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY,
                      (u16)bth0,
                      (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
                      0, qp->ibqp.qp_num,
                      hdr->lrh[3], hdr->lrh[1]);
            goto err;
        }
        /* Validate the SLID. See Ch. 9.6.1.5 and 17.2.8 */
        if (be16_to_cpu(hdr->lrh[3]) != qp->alt_ah_attr.dlid ||
            ppd_from_ibp(ibp)->port != qp->alt_ah_attr.port_num)
            goto err;
        spin_lock_irqsave(&qp->s_lock, flags);
        qib_migrate_qp(qp);
        spin_unlock_irqrestore(&qp->s_lock, flags);
    } else {
        if (!has_grh) {
            if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
                goto err;
        } else {
            if (!(qp->remote_ah_attr.ah_flags & IB_AH_GRH))
                goto err;
            guid = get_sguid(ibp,
                     qp->remote_ah_attr.grh.sgid_index);
            if (!gid_ok(&hdr->u.l.grh.dgid, ibp->gid_prefix, guid))
                goto err;
            if (!gid_ok(&hdr->u.l.grh.sgid,
                qp->remote_ah_attr.grh.dgid.global.subnet_prefix,
                qp->remote_ah_attr.grh.dgid.global.interface_id))
                goto err;
        }
        if (!qib_pkey_ok((u16)bth0,
                 qib_get_pkey(ibp, qp->s_pkey_index))) {
            qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY,
                      (u16)bth0,
                      (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
                      0, qp->ibqp.qp_num,
                      hdr->lrh[3], hdr->lrh[1]);
            goto err;
        }
        /* Validate the SLID. See Ch. 9.6.1.5 */
        if (be16_to_cpu(hdr->lrh[3]) != qp->remote_ah_attr.dlid ||
            ppd_from_ibp(ibp)->port != qp->port_num)
            goto err;
        if (qp->s_mig_state == IB_MIG_REARM &&
            !(bth0 & IB_BTH_MIG_REQ))
            qp->s_mig_state = IB_MIG_ARMED;
    }

    return 0;

err:
    return 1;
}

static void qib_ruc_loopback(struct qib_qp *sqp)
{
    struct qib_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
    struct qib_qp *qp;
    struct qib_swqe *wqe;
    struct qib_sge *sge;
    unsigned long flags;
    struct ib_wc wc;
    u64 sdata;
    atomic64_t *maddr;
    enum ib_wc_status send_status;
    int release;
    int ret;

    /*
     * Note that we check the responder QP state after
     * checking the requester's state.
     */
    qp = qib_lookup_qpn(ibp, sqp->remote_qpn);

    spin_lock_irqsave(&sqp->s_lock, flags);

    /* Return if we are already busy processing a work request. */
    if ((sqp->s_flags & (QIB_S_BUSY | QIB_S_ANY_WAIT)) ||
        !(ib_qib_state_ops[sqp->state] & QIB_PROCESS_OR_FLUSH_SEND))
        goto unlock;

    sqp->s_flags |= QIB_S_BUSY;

again:
    if (sqp->s_last == sqp->s_head)
        goto clr_busy;
    wqe = get_swqe_ptr(sqp, sqp->s_last);

    /* Return if it is not OK to start a new work reqeust. */
    if (!(ib_qib_state_ops[sqp->state] & QIB_PROCESS_NEXT_SEND_OK)) {
        if (!(ib_qib_state_ops[sqp->state] & QIB_FLUSH_SEND))
            goto clr_busy;
        /* We are in the error state, flush the work request. */
        send_status = IB_WC_WR_FLUSH_ERR;
        goto flush_send;
    }

    /*
     * We can rely on the entry not changing without the s_lock
     * being held until we update s_last.
     * We increment s_cur to indicate s_last is in progress.
     */
    if (sqp->s_last == sqp->s_cur) {
        if (++sqp->s_cur >= sqp->s_size)
            sqp->s_cur = 0;
    }
    spin_unlock_irqrestore(&sqp->s_lock, flags);

    if (!qp || !(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK) ||
        qp->ibqp.qp_type != sqp->ibqp.qp_type) {
        ibp->n_pkt_drops++;
        /*
         * For RC, the requester would timeout and retry so
         * shortcut the timeouts and just signal too many retries.
         */
        if (sqp->ibqp.qp_type == IB_QPT_RC)
            send_status = IB_WC_RETRY_EXC_ERR;
        else
            send_status = IB_WC_SUCCESS;
        goto serr;
    }

    memset(&wc, 0, sizeof wc);
    send_status = IB_WC_SUCCESS;

    release = 1;
    sqp->s_sge.sge = wqe->sg_list[0];
    sqp->s_sge.sg_list = wqe->sg_list + 1;
    sqp->s_sge.num_sge = wqe->wr.num_sge;
    sqp->s_len = wqe->length;
    switch (wqe->wr.opcode) {
    case IB_WR_SEND_WITH_IMM:
        wc.wc_flags = IB_WC_WITH_IMM;
        wc.ex.imm_data = wqe->wr.ex.imm_data;
        /* FALLTHROUGH */
    case IB_WR_SEND:
        ret = qib_get_rwqe(qp, 0);
        if (ret < 0)
            goto op_err;
        if (!ret)
            goto rnr_nak;
        break;

    case IB_WR_RDMA_WRITE_WITH_IMM:
        if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
            goto inv_err;
        wc.wc_flags = IB_WC_WITH_IMM;
        wc.ex.imm_data = wqe->wr.ex.imm_data;
        ret = qib_get_rwqe(qp, 1);
        if (ret < 0)
            goto op_err;
        if (!ret)
            goto rnr_nak;
        /* FALLTHROUGH */
    case IB_WR_RDMA_WRITE:
        if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
            goto inv_err;
        if (wqe->length == 0)
            break;
        if (unlikely(!qib_rkey_ok(qp, &qp->r_sge.sge, wqe->length,
                      wqe->wr.wr.rdma.remote_addr,
                      wqe->wr.wr.rdma.rkey,
                      IB_ACCESS_REMOTE_WRITE)))
            goto acc_err;
        qp->r_sge.sg_list = NULL;
        qp->r_sge.num_sge = 1;
        qp->r_sge.total_len = wqe->length;
        break;

    case IB_WR_RDMA_READ:
        if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
            goto inv_err;
        if (unlikely(!qib_rkey_ok(qp, &sqp->s_sge.sge, wqe->length,
                      wqe->wr.wr.rdma.remote_addr,
                      wqe->wr.wr.rdma.rkey,
                      IB_ACCESS_REMOTE_READ)))
            goto acc_err;
        release = 0;
        sqp->s_sge.sg_list = NULL;
        sqp->s_sge.num_sge = 1;
        qp->r_sge.sge = wqe->sg_list[0];
        qp->r_sge.sg_list = wqe->sg_list + 1;
        qp->r_sge.num_sge = wqe->wr.num_sge;
        qp->r_sge.total_len = wqe->length;
        break;

    case IB_WR_ATOMIC_CMP_AND_SWP:
    case IB_WR_ATOMIC_FETCH_AND_ADD:
        if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
            goto inv_err;
        if (unlikely(!qib_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
                      wqe->wr.wr.atomic.remote_addr,
                      wqe->wr.wr.atomic.rkey,
                      IB_ACCESS_REMOTE_ATOMIC)))
            goto acc_err;
        /* Perform atomic OP and save result. */
        maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
        sdata = wqe->wr.wr.atomic.compare_add;
        *(u64 *) sqp->s_sge.sge.vaddr =
            (wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) ?
            (u64) atomic64_add_return(sdata, maddr) - sdata :
            (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
                      sdata, wqe->wr.wr.atomic.swap);
        qib_put_mr(qp->r_sge.sge.mr);
        qp->r_sge.num_sge = 0;
        goto send_comp;

    default:
        send_status = IB_WC_LOC_QP_OP_ERR;
        goto serr;
    }

    sge = &sqp->s_sge.sge;
    while (sqp->s_len) {
        u32 len = sqp->s_len;

        if (len > sge->length)
            len = sge->length;
        if (len > sge->sge_length)
            len = sge->sge_length;
        BUG_ON(len == 0);
        qib_copy_sge(&qp->r_sge, sge->vaddr, len, release);
        sge->vaddr += len;
        sge->length -= len;
        sge->sge_length -= len;
        if (sge->sge_length == 0) {
            if (!release)
                qib_put_mr(sge->mr);
            if (--sqp->s_sge.num_sge)
                *sge = *sqp->s_sge.sg_list++;
        } else if (sge->length == 0 && sge->mr->lkey) {
            if (++sge->n >= QIB_SEGSZ) {
                if (++sge->m >= sge->mr->mapsz)
                    break;
                sge->n = 0;
            }
            sge->vaddr =
                sge->mr->map[sge->m]->segs[sge->n].vaddr;
            sge->length =
                sge->mr->map[sge->m]->segs[sge->n].length;
        }
        sqp->s_len -= len;
    }
    if (release)
        qib_put_ss(&qp->r_sge);

    if (!test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags))
        goto send_comp;

    if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM)
        wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
    else
        wc.opcode = IB_WC_RECV;
    wc.wr_id = qp->r_wr_id;
    wc.status = IB_WC_SUCCESS;
    wc.byte_len = wqe->length;
    wc.qp = &qp->ibqp;
    wc.src_qp = qp->remote_qpn;
    wc.slid = qp->remote_ah_attr.dlid;
    wc.sl = qp->remote_ah_attr.sl;
    wc.port_num = 1;
    /* Signal completion event if the solicited bit is set. */
    qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
               wqe->wr.send_flags & IB_SEND_SOLICITED);

send_comp:
    spin_lock_irqsave(&sqp->s_lock, flags);
    ibp->n_loop_pkts++;
flush_send:
    sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
    qib_send_complete(sqp, wqe, send_status);
    goto again;

rnr_nak:
    /* Handle RNR NAK */
    if (qp->ibqp.qp_type == IB_QPT_UC)
        goto send_comp;
    ibp->n_rnr_naks++;
    /*
     * Note: we don't need the s_lock held since the BUSY flag
     * makes this single threaded.
     */
    if (sqp->s_rnr_retry == 0) {
        send_status = IB_WC_RNR_RETRY_EXC_ERR;
        goto serr;
    }
    if (sqp->s_rnr_retry_cnt < 7)
        sqp->s_rnr_retry--;
    spin_lock_irqsave(&sqp->s_lock, flags);
    if (!(ib_qib_state_ops[sqp->state] & QIB_PROCESS_RECV_OK))
        goto clr_busy;
    sqp->s_flags |= QIB_S_WAIT_RNR;
    sqp->s_timer.function = qib_rc_rnr_retry;
    sqp->s_timer.expires = jiffies +
        usecs_to_jiffies(ib_qib_rnr_table[qp->r_min_rnr_timer]);
    add_timer(&sqp->s_timer);
    goto clr_busy;

op_err:
    send_status = IB_WC_REM_OP_ERR;
    wc.status = IB_WC_LOC_QP_OP_ERR;
    goto err;

inv_err:
    send_status = IB_WC_REM_INV_REQ_ERR;
    wc.status = IB_WC_LOC_QP_OP_ERR;
    goto err;

acc_err:
    send_status = IB_WC_REM_ACCESS_ERR;
    wc.status = IB_WC_LOC_PROT_ERR;
err:
    /* responder goes to error state */
    qib_rc_error(qp, wc.status);

serr:
    spin_lock_irqsave(&sqp->s_lock, flags);
    qib_send_complete(sqp, wqe, send_status);
    if (sqp->ibqp.qp_type == IB_QPT_RC) {
        int lastwqe = qib_error_qp(sqp, IB_WC_WR_FLUSH_ERR);

        sqp->s_flags &= ~QIB_S_BUSY;
        spin_unlock_irqrestore(&sqp->s_lock, flags);
        if (lastwqe) {
            struct ib_event ev;

            ev.device = sqp->ibqp.device;
            ev.element.qp = &sqp->ibqp;
            ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
            sqp->ibqp.event_handler(&ev, sqp->ibqp.qp_context);
        }
        goto done;
    }
clr_busy:
    sqp->s_flags &= ~QIB_S_BUSY;
unlock:
    spin_unlock_irqrestore(&sqp->s_lock, flags);
done:
    if (qp && atomic_dec_and_test(&qp->refcount))
        wake_up(&qp->wait);
}

u32 qib_make_grh(struct qib_ibport *ibp, struct ib_grh *hdr,
         struct ib_global_route *grh, u32 hwords, u32 nwords)
{
    hdr->version_tclass_flow =
        cpu_to_be32((IB_GRH_VERSION << IB_GRH_VERSION_SHIFT) |
                (grh->traffic_class << IB_GRH_TCLASS_SHIFT) |
                (grh->flow_label << IB_GRH_FLOW_SHIFT));
    hdr->paylen = cpu_to_be16((hwords - 2 + nwords + SIZE_OF_CRC) << 2);
    /* next_hdr is defined by C8-7 in ch. 8.4.1 */
    hdr->next_hdr = IB_GRH_NEXT_HDR;
    hdr->hop_limit = grh->hop_limit;
    /* The SGID is 32-bit aligned. */
    hdr->sgid.global.subnet_prefix = ibp->gid_prefix;
    hdr->sgid.global.interface_id = grh->sgid_index ?
        ibp->guids[grh->sgid_index - 1] : ppd_from_ibp(ibp)->guid;
    hdr->dgid = grh->dgid;

    /* GRH header size in 32-bit words. */
    return sizeof(struct ib_grh) / sizeof(u32);
}

void qib_make_ruc_header(struct qib_qp *qp, struct qib_other_headers *ohdr,
             u32 bth0, u32 bth2)
{
    struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
    u16 lrh0;
    u32 nwords;
    u32 extra_bytes;

    /* Construct the header. */
    extra_bytes = -qp->s_cur_size & 3;
    nwords = (qp->s_cur_size + extra_bytes) >> 2;
    lrh0 = QIB_LRH_BTH;
    if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
        qp->s_hdrwords += qib_make_grh(ibp, &qp->s_hdr->u.l.grh,
                           &qp->remote_ah_attr.grh,
                           qp->s_hdrwords, nwords);
        lrh0 = QIB_LRH_GRH;
    }
    lrh0 |= ibp->sl_to_vl[qp->remote_ah_attr.sl] << 12 |
        qp->remote_ah_attr.sl << 4;
    qp->s_hdr->lrh[0] = cpu_to_be16(lrh0);
    qp->s_hdr->lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
    qp->s_hdr->lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
    qp->s_hdr->lrh[3] = cpu_to_be16(ppd_from_ibp(ibp)->lid |
                       qp->remote_ah_attr.src_path_bits);
    bth0 |= qib_get_pkey(ibp, qp->s_pkey_index);
    bth0 |= extra_bytes << 20;
    if (qp->s_mig_state == IB_MIG_MIGRATED)
        bth0 |= IB_BTH_MIG_REQ;
    ohdr->bth[0] = cpu_to_be32(bth0);
    ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
    ohdr->bth[2] = cpu_to_be32(bth2);
}

void qib_do_send(struct work_struct *work)
{
    struct qib_qp *qp = container_of(work, struct qib_qp, s_work);
    struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
    struct qib_pportdata *ppd = ppd_from_ibp(ibp);
    int (*make_req)(struct qib_qp *qp);
    unsigned long flags;

    if ((qp->ibqp.qp_type == IB_QPT_RC ||
         qp->ibqp.qp_type == IB_QPT_UC) &&
        (qp->remote_ah_attr.dlid & ~((1 << ppd->lmc) - 1)) == ppd->lid) {
        qib_ruc_loopback(qp);
        return;
    }

    if (qp->ibqp.qp_type == IB_QPT_RC)
        make_req = qib_make_rc_req;
    else if (qp->ibqp.qp_type == IB_QPT_UC)
        make_req = qib_make_uc_req;
    else
        make_req = qib_make_ud_req;

    spin_lock_irqsave(&qp->s_lock, flags);

    /* Return if we are already busy processing a work request. */
    if (!qib_send_ok(qp)) {
        spin_unlock_irqrestore(&qp->s_lock, flags);
        return;
    }

    qp->s_flags |= QIB_S_BUSY;

    spin_unlock_irqrestore(&qp->s_lock, flags);

    do {
        /* Check for a constructed packet to be sent. */
        if (qp->s_hdrwords != 0) {
            /*
             * If the packet cannot be sent now, return and
             * the send tasklet will be woken up later.
             */
            if (qib_verbs_send(qp, qp->s_hdr, qp->s_hdrwords,
                       qp->s_cur_sge, qp->s_cur_size))
                break;
            /* Record that s_hdr is empty. */
            qp->s_hdrwords = 0;
        }
    } while (make_req(qp));
}

/*
 * This should be called with s_lock held.
 */
void qib_send_complete(struct qib_qp *qp, struct qib_swqe *wqe,
               enum ib_wc_status status)
{
    u32 old_last, last;
    unsigned i;

    if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_OR_FLUSH_SEND))
        return;

    for (i = 0; i < wqe->wr.num_sge; i++) {
        struct qib_sge *sge = &wqe->sg_list[i];

        qib_put_mr(sge->mr);
    }
    if (qp->ibqp.qp_type == IB_QPT_UD ||
        qp->ibqp.qp_type == IB_QPT_SMI ||
        qp->ibqp.qp_type == IB_QPT_GSI)
        atomic_dec(&to_iah(wqe->wr.wr.ud.ah)->refcount);

    /* See ch. 11.2.4.1 and 10.7.3.1 */
    if (!(qp->s_flags & QIB_S_SIGNAL_REQ_WR) ||
        (wqe->wr.send_flags & IB_SEND_SIGNALED) ||
        status != IB_WC_SUCCESS) {
        struct ib_wc wc;

        memset(&wc, 0, sizeof wc);
        wc.wr_id = wqe->wr.wr_id;
        wc.status = status;
        wc.opcode = ib_qib_wc_opcode[wqe->wr.opcode];
        wc.qp = &qp->ibqp;
        if (status == IB_WC_SUCCESS)
            wc.byte_len = wqe->length;
        qib_cq_enter(to_icq(qp->ibqp.send_cq), &wc,
                 status != IB_WC_SUCCESS);
    }

    last = qp->s_last;
    old_last = last;
    if (++last >= qp->s_size)
        last = 0;
    qp->s_last = last;
    if (qp->s_acked == old_last)
        qp->s_acked = last;
    if (qp->s_cur == old_last)
        qp->s_cur = last;
    if (qp->s_tail == old_last)
        qp->s_tail = last;
    if (qp->state == IB_QPS_SQD && last == qp->s_cur)
        qp->s_draining = 0;
}