ipath_ud.c

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/*
 * Copyright (c) 2006, 2007, 2008 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/sched.h>
#include <rdma/ib_smi.h>

#include "ipath_verbs.h"
#include "ipath_kernel.h"

static void ipath_ud_loopback(struct ipath_qp *sqp, struct ipath_swqe *swqe)
{
    struct ipath_ibdev *dev = to_idev(sqp->ibqp.device);
    struct ipath_qp *qp;
    struct ib_ah_attr *ah_attr;
    unsigned long flags;
    struct ipath_rq *rq;
    struct ipath_srq *srq;
    struct ipath_sge_state rsge;
    struct ipath_sge *sge;
    struct ipath_rwq *wq;
    struct ipath_rwqe *wqe;
    void (*handler)(struct ib_event *, void *);
    struct ib_wc wc;
    u32 tail;
    u32 rlen;
    u32 length;

    qp = ipath_lookup_qpn(&dev->qp_table, swqe->wr.wr.ud.remote_qpn);
    if (!qp || !(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK)) {
        dev->n_pkt_drops++;
        goto done;
    }

    /*
     * Check that the qkey matches (except for QP0, see 9.6.1.4.1).
     * Qkeys with the high order bit set mean use the
     * qkey from the QP context instead of the WR (see 10.2.5).
     */
    if (unlikely(qp->ibqp.qp_num &&
             ((int) swqe->wr.wr.ud.remote_qkey < 0 ?
              sqp->qkey : swqe->wr.wr.ud.remote_qkey) != qp->qkey)) {
        /* XXX OK to lose a count once in a while. */
        dev->qkey_violations++;
        dev->n_pkt_drops++;
        goto drop;
    }

    /*
     * A GRH is expected to precede the data even if not
     * present on the wire.
     */
    length = swqe->length;
    memset(&wc, 0, sizeof wc);
    wc.byte_len = length + sizeof(struct ib_grh);

    if (swqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
        wc.wc_flags = IB_WC_WITH_IMM;
        wc.ex.imm_data = swqe->wr.ex.imm_data;
    }

    /*
     * This would be a lot simpler if we could call ipath_get_rwqe()
     * but that uses state that the receive interrupt handler uses
     * so we would need to lock out receive interrupts while doing
     * local loopback.
     */
    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;
    }

    /*
     * Get the next work request entry to find where to put the data.
     * Note that it is safe to drop the lock after changing rq->tail
     * since ipath_post_receive() won't fill the empty slot.
     */
    spin_lock_irqsave(&rq->lock, flags);
    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)) {
        spin_unlock_irqrestore(&rq->lock, flags);
        dev->n_pkt_drops++;
        goto drop;
    }
    wqe = get_rwqe_ptr(rq, tail);
    rsge.sg_list = qp->r_ud_sg_list;
    if (!ipath_init_sge(qp, wqe, &rlen, &rsge)) {
        spin_unlock_irqrestore(&rq->lock, flags);
        dev->n_pkt_drops++;
        goto drop;
    }
    /* Silently drop packets which are too big. */
    if (wc.byte_len > rlen) {
        spin_unlock_irqrestore(&rq->lock, flags);
        dev->n_pkt_drops++;
        goto drop;
    }
    if (++tail >= rq->size)
        tail = 0;
    wq->tail = tail;
    wc.wr_id = wqe->wr_id;
    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);
        } else
            spin_unlock_irqrestore(&rq->lock, flags);
    } else
        spin_unlock_irqrestore(&rq->lock, flags);

    ah_attr = &to_iah(swqe->wr.wr.ud.ah)->attr;
    if (ah_attr->ah_flags & IB_AH_GRH) {
        ipath_copy_sge(&rsge, &ah_attr->grh, sizeof(struct ib_grh));
        wc.wc_flags |= IB_WC_GRH;
    } else
        ipath_skip_sge(&rsge, sizeof(struct ib_grh));
    sge = swqe->sg_list;
    while (length) {
        u32 len = sge->length;

        if (len > length)
            len = length;
        if (len > sge->sge_length)
            len = sge->sge_length;
        BUG_ON(len == 0);
        ipath_copy_sge(&rsge, sge->vaddr, len);
        sge->vaddr += len;
        sge->length -= len;
        sge->sge_length -= len;
        if (sge->sge_length == 0) {
            if (--swqe->wr.num_sge)
                sge++;
        } else if (sge->length == 0 && sge->mr != NULL) {
            if (++sge->n >= IPATH_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;
        }
        length -= len;
    }
    wc.status = IB_WC_SUCCESS;
    wc.opcode = IB_WC_RECV;
    wc.qp = &qp->ibqp;
    wc.src_qp = sqp->ibqp.qp_num;
    /* XXX do we know which pkey matched? Only needed for GSI. */
    wc.pkey_index = 0;
    wc.slid = dev->dd->ipath_lid |
        (ah_attr->src_path_bits &
         ((1 << dev->dd->ipath_lmc) - 1));
    wc.sl = ah_attr->sl;
    wc.dlid_path_bits =
        ah_attr->dlid & ((1 << dev->dd->ipath_lmc) - 1);
    wc.port_num = 1;
    /* Signal completion event if the solicited bit is set. */
    ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
               swqe->wr.send_flags & IB_SEND_SOLICITED);
drop:
    if (atomic_dec_and_test(&qp->refcount))
        wake_up(&qp->wait);
done:;
}

int ipath_make_ud_req(struct ipath_qp *qp)
{
    struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
    struct ipath_other_headers *ohdr;
    struct ib_ah_attr *ah_attr;
    struct ipath_swqe *wqe;
    unsigned long flags;
    u32 nwords;
    u32 extra_bytes;
    u32 bth0;
    u16 lrh0;
    u16 lid;
    int ret = 0;
    int next_cur;

    spin_lock_irqsave(&qp->s_lock, flags);

    if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_NEXT_SEND_OK)) {
        if (!(ib_ipath_state_ops[qp->state] & IPATH_FLUSH_SEND))
            goto bail;
        /* We are in the error state, flush the work request. */
        if (qp->s_last == qp->s_head)
            goto bail;
        /* If DMAs are in progress, we can't flush immediately. */
        if (atomic_read(&qp->s_dma_busy)) {
            qp->s_flags |= IPATH_S_WAIT_DMA;
            goto bail;
        }
        wqe = get_swqe_ptr(qp, qp->s_last);
        ipath_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
        goto done;
    }

    if (qp->s_cur == qp->s_head)
        goto bail;

    wqe = get_swqe_ptr(qp, qp->s_cur);
    next_cur = qp->s_cur + 1;
    if (next_cur >= qp->s_size)
        next_cur = 0;

    /* Construct the header. */
    ah_attr = &to_iah(wqe->wr.wr.ud.ah)->attr;
    if (ah_attr->dlid >= IPATH_MULTICAST_LID_BASE) {
        if (ah_attr->dlid != IPATH_PERMISSIVE_LID)
            dev->n_multicast_xmit++;
        else
            dev->n_unicast_xmit++;
    } else {
        dev->n_unicast_xmit++;
        lid = ah_attr->dlid & ~((1 << dev->dd->ipath_lmc) - 1);
        if (unlikely(lid == dev->dd->ipath_lid)) {
            /*
             * If DMAs are in progress, we can't generate
             * a completion for the loopback packet since
             * it would be out of order.
             * XXX Instead of waiting, we could queue a
             * zero length descriptor so we get a callback.
             */
            if (atomic_read(&qp->s_dma_busy)) {
                qp->s_flags |= IPATH_S_WAIT_DMA;
                goto bail;
            }
            qp->s_cur = next_cur;
            spin_unlock_irqrestore(&qp->s_lock, flags);
            ipath_ud_loopback(qp, wqe);
            spin_lock_irqsave(&qp->s_lock, flags);
            ipath_send_complete(qp, wqe, IB_WC_SUCCESS);
            goto done;
        }
    }

    qp->s_cur = next_cur;
    extra_bytes = -wqe->length & 3;
    nwords = (wqe->length + extra_bytes) >> 2;

    /* header size in 32-bit words LRH+BTH+DETH = (8+12+8)/4. */
    qp->s_hdrwords = 7;
    qp->s_cur_size = wqe->length;
    qp->s_cur_sge = &qp->s_sge;
    qp->s_dmult = ah_attr->static_rate;
    qp->s_wqe = wqe;
    qp->s_sge.sge = wqe->sg_list[0];
    qp->s_sge.sg_list = wqe->sg_list + 1;
    qp->s_sge.num_sge = wqe->wr.num_sge;

    if (ah_attr->ah_flags & IB_AH_GRH) {
        /* Header size in 32-bit words. */
        qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
                         &ah_attr->grh,
                         qp->s_hdrwords, nwords);
        lrh0 = IPATH_LRH_GRH;
        ohdr = &qp->s_hdr.u.l.oth;
        /*
         * Don't worry about sending to locally attached multicast
         * QPs.  It is unspecified by the spec. what happens.
         */
    } else {
        /* Header size in 32-bit words. */
        lrh0 = IPATH_LRH_BTH;
        ohdr = &qp->s_hdr.u.oth;
    }
    if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
        qp->s_hdrwords++;
        ohdr->u.ud.imm_data = wqe->wr.ex.imm_data;
        bth0 = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE << 24;
    } else
        bth0 = IB_OPCODE_UD_SEND_ONLY << 24;
    lrh0 |= ah_attr->sl << 4;
    if (qp->ibqp.qp_type == IB_QPT_SMI)
        lrh0 |= 0xF000; /* Set VL (see ch. 13.5.3.1) */
    qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
    qp->s_hdr.lrh[1] = cpu_to_be16(ah_attr->dlid);  /* DEST LID */
    qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords +
                       SIZE_OF_CRC);
    lid = dev->dd->ipath_lid;
    if (lid) {
        lid |= ah_attr->src_path_bits &
            ((1 << dev->dd->ipath_lmc) - 1);
        qp->s_hdr.lrh[3] = cpu_to_be16(lid);
    } else
        qp->s_hdr.lrh[3] = IB_LID_PERMISSIVE;
    if (wqe->wr.send_flags & IB_SEND_SOLICITED)
        bth0 |= 1 << 23;
    bth0 |= extra_bytes << 20;
    bth0 |= qp->ibqp.qp_type == IB_QPT_SMI ? IPATH_DEFAULT_P_KEY :
        ipath_get_pkey(dev->dd, qp->s_pkey_index);
    ohdr->bth[0] = cpu_to_be32(bth0);
    /*
     * Use the multicast QP if the destination LID is a multicast LID.
     */
    ohdr->bth[1] = ah_attr->dlid >= IPATH_MULTICAST_LID_BASE &&
        ah_attr->dlid != IPATH_PERMISSIVE_LID ?
        cpu_to_be32(IPATH_MULTICAST_QPN) :
        cpu_to_be32(wqe->wr.wr.ud.remote_qpn);
    ohdr->bth[2] = cpu_to_be32(qp->s_next_psn++ & IPATH_PSN_MASK);
    /*
     * Qkeys with the high order bit set mean use the
     * qkey from the QP context instead of the WR (see 10.2.5).
     */
    ohdr->u.ud.deth[0] = cpu_to_be32((int)wqe->wr.wr.ud.remote_qkey < 0 ?
                     qp->qkey : wqe->wr.wr.ud.remote_qkey);
    ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);

done:
    ret = 1;
    goto unlock;

bail:
    qp->s_flags &= ~IPATH_S_BUSY;
unlock:
    spin_unlock_irqrestore(&qp->s_lock, flags);
    return ret;
}

void ipath_ud_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
          int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
{
    struct ipath_other_headers *ohdr;
    int opcode;
    u32 hdrsize;
    u32 pad;
    struct ib_wc wc;
    u32 qkey;
    u32 src_qp;
    u16 dlid;
    int header_in_data;

    /* Check for GRH */
    if (!has_grh) {
        ohdr = &hdr->u.oth;
        hdrsize = 8 + 12 + 8;   /* LRH + BTH + DETH */
        qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
        src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
        header_in_data = 0;
    } else {
        ohdr = &hdr->u.l.oth;
        hdrsize = 8 + 40 + 12 + 8; /* LRH + GRH + BTH + DETH */
        /*
         * The header with GRH is 68 bytes and the core driver sets
         * the eager header buffer size to 56 bytes so the last 12
         * bytes of the IB header is in the data buffer.
         */
        header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
        if (header_in_data) {
            qkey = be32_to_cpu(((__be32 *) data)[1]);
            src_qp = be32_to_cpu(((__be32 *) data)[2]);
            data += 12;
        } else {
            qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
            src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
        }
    }
    src_qp &= IPATH_QPN_MASK;

    /*
     * Check that the permissive LID is only used on QP0
     * and the QKEY matches (see 9.6.1.4.1 and 9.6.1.5.1).
     */
    if (qp->ibqp.qp_num) {
        if (unlikely(hdr->lrh[1] == IB_LID_PERMISSIVE ||
                 hdr->lrh[3] == IB_LID_PERMISSIVE)) {
            dev->n_pkt_drops++;
            goto bail;
        }
        if (unlikely(qkey != qp->qkey)) {
            /* XXX OK to lose a count once in a while. */
            dev->qkey_violations++;
            dev->n_pkt_drops++;
            goto bail;
        }
    } else if (hdr->lrh[1] == IB_LID_PERMISSIVE ||
           hdr->lrh[3] == IB_LID_PERMISSIVE) {
        struct ib_smp *smp = (struct ib_smp *) data;

        if (smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
            dev->n_pkt_drops++;
            goto bail;
        }
    }

    /*
     * The opcode is in the low byte when its in network order
     * (top byte when in host order).
     */
    opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
    if (qp->ibqp.qp_num > 1 &&
        opcode == IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE) {
        if (header_in_data) {
            wc.ex.imm_data = *(__be32 *) data;
            data += sizeof(__be32);
        } else
            wc.ex.imm_data = ohdr->u.ud.imm_data;
        wc.wc_flags = IB_WC_WITH_IMM;
        hdrsize += sizeof(u32);
    } else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
        wc.ex.imm_data = 0;
        wc.wc_flags = 0;
    } else {
        dev->n_pkt_drops++;
        goto bail;
    }

    /* Get the number of bytes the message was padded by. */
    pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
    if (unlikely(tlen < (hdrsize + pad + 4))) {
        /* Drop incomplete packets. */
        dev->n_pkt_drops++;
        goto bail;
    }
    tlen -= hdrsize + pad + 4;

    /* Drop invalid MAD packets (see 13.5.3.1). */
    if (unlikely((qp->ibqp.qp_num == 0 &&
              (tlen != 256 ||
               (be16_to_cpu(hdr->lrh[0]) >> 12) != 15)) ||
             (qp->ibqp.qp_num == 1 &&
              (tlen != 256 ||
               (be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))) {
        dev->n_pkt_drops++;
        goto bail;
    }

    /*
     * A GRH is expected to precede the data even if not
     * present on the wire.
     */
    wc.byte_len = tlen + sizeof(struct ib_grh);

    /*
     * Get the next work request entry to find where to put the data.
     */
    if (qp->r_flags & IPATH_R_REUSE_SGE)
        qp->r_flags &= ~IPATH_R_REUSE_SGE;
    else if (!ipath_get_rwqe(qp, 0)) {
        /*
         * Count VL15 packets dropped due to no receive buffer.
         * Otherwise, count them as buffer overruns since usually,
         * the HW will be able to receive packets even if there are
         * no QPs with posted receive buffers.
         */
        if (qp->ibqp.qp_num == 0)
            dev->n_vl15_dropped++;
        else
            dev->rcv_errors++;
        goto bail;
    }
    /* Silently drop packets which are too big. */
    if (wc.byte_len > qp->r_len) {
        qp->r_flags |= IPATH_R_REUSE_SGE;
        dev->n_pkt_drops++;
        goto bail;
    }
    if (has_grh) {
        ipath_copy_sge(&qp->r_sge, &hdr->u.l.grh,
                   sizeof(struct ib_grh));
        wc.wc_flags |= IB_WC_GRH;
    } else
        ipath_skip_sge(&qp->r_sge, sizeof(struct ib_grh));
    ipath_copy_sge(&qp->r_sge, data,
               wc.byte_len - sizeof(struct ib_grh));
    if (!test_and_clear_bit(IPATH_R_WRID_VALID, &qp->r_aflags))
        goto bail;
    wc.wr_id = qp->r_wr_id;
    wc.status = IB_WC_SUCCESS;
    wc.opcode = IB_WC_RECV;
    wc.vendor_err = 0;
    wc.qp = &qp->ibqp;
    wc.src_qp = src_qp;
    /* XXX do we know which pkey matched? Only needed for GSI. */
    wc.pkey_index = 0;
    wc.slid = be16_to_cpu(hdr->lrh[3]);
    wc.sl = (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF;
    dlid = be16_to_cpu(hdr->lrh[1]);
    /*
     * Save the LMC lower bits if the destination LID is a unicast LID.
     */
    wc.dlid_path_bits = dlid >= IPATH_MULTICAST_LID_BASE ? 0 :
        dlid & ((1 << dev->dd->ipath_lmc) - 1);
    wc.port_num = 1;
    /* Signal completion event if the solicited bit is set. */
    ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
               (ohdr->bth[0] &
            cpu_to_be32(1 << 23)) != 0);

bail:;
}