git.oblomov.eu Git - linux-2.6/blob - drivers/infiniband/hw/ipath/ipath_ud.c

   1 /*
   2  * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
   3  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33
  34 #include <rdma/ib_smi.h>
  35
  36 #include "ipath_verbs.h"
  37 #include "ipath_kernel.h"
  38
  39 /**
  40  * ipath_ud_loopback - handle send on loopback QPs
  41  * @sqp: the sending QP
  42  * @swqe: the send work request
  43  *
  44  * This is called from ipath_make_ud_req() to forward a WQE addressed
  45  * to the same HCA.
  46  * Note that the receive interrupt handler may be calling ipath_ud_rcv()
  47  * while this is being called.
  48  */
  49 static void ipath_ud_loopback(struct ipath_qp *sqp, struct ipath_swqe *swqe)
  50 {
  51         struct ipath_ibdev *dev = to_idev(sqp->ibqp.device);
  52         struct ipath_qp *qp;
  53         struct ib_ah_attr *ah_attr;
  54         unsigned long flags;
  55         struct ipath_rq *rq;
  56         struct ipath_srq *srq;
  57         struct ipath_sge_state rsge;
  58         struct ipath_sge *sge;
  59         struct ipath_rwq *wq;
  60         struct ipath_rwqe *wqe;
  61         void (*handler)(struct ib_event *, void *);
  62         struct ib_wc wc;
  63         u32 tail;
  64         u32 rlen;
  65         u32 length;
  66
  67         qp = ipath_lookup_qpn(&dev->qp_table, swqe->wr.wr.ud.remote_qpn);
  68         if (!qp) {
  69                 dev->n_pkt_drops++;
  70                 goto send_comp;
  71         }
  72
  73         rsge.sg_list = NULL;
  74
  75         /*
  76          * Check that the qkey matches (except for QP0, see 9.6.1.4.1).
  77          * Qkeys with the high order bit set mean use the
  78          * qkey from the QP context instead of the WR (see 10.2.5).
  79          */
  80         if (unlikely(qp->ibqp.qp_num &&
  81                      ((int) swqe->wr.wr.ud.remote_qkey < 0 ?
  82                       sqp->qkey : swqe->wr.wr.ud.remote_qkey) != qp->qkey)) {
  83                 /* XXX OK to lose a count once in a while. */
  84                 dev->qkey_violations++;
  85                 dev->n_pkt_drops++;
  86                 goto drop;
  87         }
  88
  89         /*
  90          * A GRH is expected to preceed the data even if not
  91          * present on the wire.
  92          */
  93         length = swqe->length;
  94         wc.byte_len = length + sizeof(struct ib_grh);
  95
  96         if (swqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
  97                 wc.wc_flags = IB_WC_WITH_IMM;
  98                 wc.imm_data = swqe->wr.imm_data;
  99         } else {
 100                 wc.wc_flags = 0;
 101                 wc.imm_data = 0;
 102         }
 103
 104         /*
 105          * This would be a lot simpler if we could call ipath_get_rwqe()
 106          * but that uses state that the receive interrupt handler uses
 107          * so we would need to lock out receive interrupts while doing
 108          * local loopback.
 109          */
 110         if (qp->ibqp.srq) {
 111                 srq = to_isrq(qp->ibqp.srq);
 112                 handler = srq->ibsrq.event_handler;
 113                 rq = &srq->rq;
 114         } else {
 115                 srq = NULL;
 116                 handler = NULL;
 117                 rq = &qp->r_rq;
 118         }
 119
 120         if (rq->max_sge > 1) {
 121                 /*
 122                  * XXX We could use GFP_KERNEL if ipath_do_send()
 123                  * was always called from the tasklet instead of
 124                  * from ipath_post_send().
 125                  */
 126                 rsge.sg_list = kmalloc((rq->max_sge - 1) *
 127                                         sizeof(struct ipath_sge),
 128                                        GFP_ATOMIC);
 129                 if (!rsge.sg_list) {
 130                         dev->n_pkt_drops++;
 131                         goto drop;
 132                 }
 133         }
 134
 135         /*
 136          * Get the next work request entry to find where to put the data.
 137          * Note that it is safe to drop the lock after changing rq->tail
 138          * since ipath_post_receive() won't fill the empty slot.
 139          */
 140         spin_lock_irqsave(&rq->lock, flags);
 141         wq = rq->wq;
 142         tail = wq->tail;
 143         /* Validate tail before using it since it is user writable. */
 144         if (tail >= rq->size)
 145                 tail = 0;
 146         if (unlikely(tail == wq->head)) {
 147                 spin_unlock_irqrestore(&rq->lock, flags);
 148                 dev->n_pkt_drops++;
 149                 goto drop;
 150         }
 151         wqe = get_rwqe_ptr(rq, tail);
 152         if (!ipath_init_sge(qp, wqe, &rlen, &rsge)) {
 153                 spin_unlock_irqrestore(&rq->lock, flags);
 154                 dev->n_pkt_drops++;
 155                 goto drop;
 156         }
 157         /* Silently drop packets which are too big. */
 158         if (wc.byte_len > rlen) {
 159                 spin_unlock_irqrestore(&rq->lock, flags);
 160                 dev->n_pkt_drops++;
 161                 goto drop;
 162         }
 163         if (++tail >= rq->size)
 164                 tail = 0;
 165         wq->tail = tail;
 166         wc.wr_id = wqe->wr_id;
 167         if (handler) {
 168                 u32 n;
 169
 170                 /*
 171                  * validate head pointer value and compute
 172                  * the number of remaining WQEs.
 173                  */
 174                 n = wq->head;
 175                 if (n >= rq->size)
 176                         n = 0;
 177                 if (n < tail)
 178                         n += rq->size - tail;
 179                 else
 180                         n -= tail;
 181                 if (n < srq->limit) {
 182                         struct ib_event ev;
 183
 184                         srq->limit = 0;
 185                         spin_unlock_irqrestore(&rq->lock, flags);
 186                         ev.device = qp->ibqp.device;
 187                         ev.element.srq = qp->ibqp.srq;
 188                         ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
 189                         handler(&ev, srq->ibsrq.srq_context);
 190                 } else
 191                         spin_unlock_irqrestore(&rq->lock, flags);
 192         } else
 193                 spin_unlock_irqrestore(&rq->lock, flags);
 194
 195         ah_attr = &to_iah(swqe->wr.wr.ud.ah)->attr;
 196         if (ah_attr->ah_flags & IB_AH_GRH) {
 197                 ipath_copy_sge(&rsge, &ah_attr->grh, sizeof(struct ib_grh));
 198                 wc.wc_flags |= IB_WC_GRH;
 199         } else
 200                 ipath_skip_sge(&rsge, sizeof(struct ib_grh));
 201         sge = swqe->sg_list;
 202         while (length) {
 203                 u32 len = sge->length;
 204
 205                 if (len > length)
 206                         len = length;
 207                 if (len > sge->sge_length)
 208                         len = sge->sge_length;
 209                 BUG_ON(len == 0);
 210                 ipath_copy_sge(&rsge, sge->vaddr, len);
 211                 sge->vaddr += len;
 212                 sge->length -= len;
 213                 sge->sge_length -= len;
 214                 if (sge->sge_length == 0) {
 215                         if (--swqe->wr.num_sge)
 216                                 sge++;
 217                 } else if (sge->length == 0 && sge->mr != NULL) {
 218                         if (++sge->n >= IPATH_SEGSZ) {
 219                                 if (++sge->m >= sge->mr->mapsz)
 220                                         break;
 221                                 sge->n = 0;
 222                         }
 223                         sge->vaddr =
 224                                 sge->mr->map[sge->m]->segs[sge->n].vaddr;
 225                         sge->length =
 226                                 sge->mr->map[sge->m]->segs[sge->n].length;
 227                 }
 228                 length -= len;
 229         }
 230         wc.status = IB_WC_SUCCESS;
 231         wc.opcode = IB_WC_RECV;
 232         wc.vendor_err = 0;
 233         wc.qp = &qp->ibqp;
 234         wc.src_qp = sqp->ibqp.qp_num;
 235         /* XXX do we know which pkey matched? Only needed for GSI. */
 236         wc.pkey_index = 0;
 237         wc.slid = dev->dd->ipath_lid |
 238                 (ah_attr->src_path_bits &
 239                  ((1 << dev->dd->ipath_lmc) - 1));
 240         wc.sl = ah_attr->sl;
 241         wc.dlid_path_bits =
 242                 ah_attr->dlid & ((1 << dev->dd->ipath_lmc) - 1);
 243         wc.port_num = 1;
 244         /* Signal completion event if the solicited bit is set. */
 245         ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 246                        swqe->wr.send_flags & IB_SEND_SOLICITED);
 247 drop:
 248         kfree(rsge.sg_list);
 249         if (atomic_dec_and_test(&qp->refcount))
 250                 wake_up(&qp->wait);
 251 send_comp:
 252         ipath_send_complete(sqp, swqe, IB_WC_SUCCESS);
 253 }
 254
 255 /**
 256  * ipath_make_ud_req - construct a UD request packet
 257  * @qp: the QP
 258  *
 259  * Return 1 if constructed; otherwise, return 0.
 260  */
 261 int ipath_make_ud_req(struct ipath_qp *qp)
 262 {
 263         struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
 264         struct ipath_other_headers *ohdr;
 265         struct ib_ah_attr *ah_attr;
 266         struct ipath_swqe *wqe;
 267         u32 nwords;
 268         u32 extra_bytes;
 269         u32 bth0;
 270         u16 lrh0;
 271         u16 lid;
 272         int ret = 0;
 273
 274         if (unlikely(!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK)))
 275                 goto bail;
 276
 277         if (qp->s_cur == qp->s_head)
 278                 goto bail;
 279
 280         wqe = get_swqe_ptr(qp, qp->s_cur);
 281
 282         /* Construct the header. */
 283         ah_attr = &to_iah(wqe->wr.wr.ud.ah)->attr;
 284         if (ah_attr->dlid >= IPATH_MULTICAST_LID_BASE) {
 285                 if (ah_attr->dlid != IPATH_PERMISSIVE_LID)
 286                         dev->n_multicast_xmit++;
 287                 else
 288                         dev->n_unicast_xmit++;
 289         } else {
 290                 dev->n_unicast_xmit++;
 291                 lid = ah_attr->dlid &
 292                         ~((1 << dev->dd->ipath_lmc) - 1);
 293                 if (unlikely(lid == dev->dd->ipath_lid)) {
 294                         ipath_ud_loopback(qp, wqe);
 295                         goto done;
 296                 }
 297         }
 298
 299         extra_bytes = -wqe->length & 3;
 300         nwords = (wqe->length + extra_bytes) >> 2;
 301
 302         /* header size in 32-bit words LRH+BTH+DETH = (8+12+8)/4. */
 303         qp->s_hdrwords = 7;
 304         if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
 305                 qp->s_hdrwords++;
 306         qp->s_cur_size = wqe->length;
 307         qp->s_cur_sge = &qp->s_sge;
 308         qp->s_wqe = wqe;
 309         qp->s_sge.sge = wqe->sg_list[0];
 310         qp->s_sge.sg_list = wqe->sg_list + 1;
 311         qp->s_sge.num_sge = wqe->wr.num_sge;
 312
 313         if (ah_attr->ah_flags & IB_AH_GRH) {
 314                 /* Header size in 32-bit words. */
 315                 qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
 316                                                  &ah_attr->grh,
 317                                                  qp->s_hdrwords, nwords);
 318                 lrh0 = IPATH_LRH_GRH;
 319                 ohdr = &qp->s_hdr.u.l.oth;
 320                 /*
 321                  * Don't worry about sending to locally attached multicast
 322                  * QPs.  It is unspecified by the spec. what happens.
 323                  */
 324         } else {
 325                 /* Header size in 32-bit words. */
 326                 lrh0 = IPATH_LRH_BTH;
 327                 ohdr = &qp->s_hdr.u.oth;
 328         }
 329         if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 330                 ohdr->u.ud.imm_data = wqe->wr.imm_data;
 331                 bth0 = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE << 24;
 332         } else
 333                 bth0 = IB_OPCODE_UD_SEND_ONLY << 24;
 334         lrh0 |= ah_attr->sl << 4;
 335         if (qp->ibqp.qp_type == IB_QPT_SMI)
 336                 lrh0 |= 0xF000; /* Set VL (see ch. 13.5.3.1) */
 337         qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
 338         qp->s_hdr.lrh[1] = cpu_to_be16(ah_attr->dlid);  /* DEST LID */
 339         qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords +
 340                                            SIZE_OF_CRC);
 341         lid = dev->dd->ipath_lid;
 342         if (lid) {
 343                 lid |= ah_attr->src_path_bits &
 344                         ((1 << dev->dd->ipath_lmc) - 1);
 345                 qp->s_hdr.lrh[3] = cpu_to_be16(lid);
 346         } else
 347                 qp->s_hdr.lrh[3] = IB_LID_PERMISSIVE;
 348         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 349                 bth0 |= 1 << 23;
 350         bth0 |= extra_bytes << 20;
 351         bth0 |= qp->ibqp.qp_type == IB_QPT_SMI ? IPATH_DEFAULT_P_KEY :
 352                 ipath_get_pkey(dev->dd, qp->s_pkey_index);
 353         ohdr->bth[0] = cpu_to_be32(bth0);
 354         /*
 355          * Use the multicast QP if the destination LID is a multicast LID.
 356          */
 357         ohdr->bth[1] = ah_attr->dlid >= IPATH_MULTICAST_LID_BASE &&
 358                 ah_attr->dlid != IPATH_PERMISSIVE_LID ?
 359                 __constant_cpu_to_be32(IPATH_MULTICAST_QPN) :
 360                 cpu_to_be32(wqe->wr.wr.ud.remote_qpn);
 361         ohdr->bth[2] = cpu_to_be32(qp->s_next_psn++ & IPATH_PSN_MASK);
 362         /*
 363          * Qkeys with the high order bit set mean use the
 364          * qkey from the QP context instead of the WR (see 10.2.5).
 365          */
 366         ohdr->u.ud.deth[0] = cpu_to_be32((int)wqe->wr.wr.ud.remote_qkey < 0 ?
 367                                          qp->qkey : wqe->wr.wr.ud.remote_qkey);
 368         ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);
 369
 370 done:
 371         if (++qp->s_cur >= qp->s_size)
 372                 qp->s_cur = 0;
 373         ret = 1;
 374
 375 bail:
 376         return ret;
 377 }
 378
 379 /**
 380  * ipath_ud_rcv - receive an incoming UD packet
 381  * @dev: the device the packet came in on
 382  * @hdr: the packet header
 383  * @has_grh: true if the packet has a GRH
 384  * @data: the packet data
 385  * @tlen: the packet length
 386  * @qp: the QP the packet came on
 387  *
 388  * This is called from ipath_qp_rcv() to process an incoming UD packet
 389  * for the given QP.
 390  * Called at interrupt level.
 391  */
 392 void ipath_ud_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
 393                   int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
 394 {
 395         struct ipath_other_headers *ohdr;
 396         int opcode;
 397         u32 hdrsize;
 398         u32 pad;
 399         struct ib_wc wc;
 400         u32 qkey;
 401         u32 src_qp;
 402         u16 dlid;
 403         int header_in_data;
 404
 405         /* Check for GRH */
 406         if (!has_grh) {
 407                 ohdr = &hdr->u.oth;
 408                 hdrsize = 8 + 12 + 8;   /* LRH + BTH + DETH */
 409                 qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
 410                 src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
 411                 header_in_data = 0;
 412         } else {
 413                 ohdr = &hdr->u.l.oth;
 414                 hdrsize = 8 + 40 + 12 + 8; /* LRH + GRH + BTH + DETH */
 415                 /*
 416                  * The header with GRH is 68 bytes and the core driver sets
 417                  * the eager header buffer size to 56 bytes so the last 12
 418                  * bytes of the IB header is in the data buffer.
 419                  */
 420                 header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
 421                 if (header_in_data) {
 422                         qkey = be32_to_cpu(((__be32 *) data)[1]);
 423                         src_qp = be32_to_cpu(((__be32 *) data)[2]);
 424                         data += 12;
 425                 } else {
 426                         qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
 427                         src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
 428                 }
 429         }
 430         src_qp &= IPATH_QPN_MASK;
 431
 432         /*
 433          * Check that the permissive LID is only used on QP0
 434          * and the QKEY matches (see 9.6.1.4.1 and 9.6.1.5.1).
 435          */
 436         if (qp->ibqp.qp_num) {
 437                 if (unlikely(hdr->lrh[1] == IB_LID_PERMISSIVE ||
 438                              hdr->lrh[3] == IB_LID_PERMISSIVE)) {
 439                         dev->n_pkt_drops++;
 440                         goto bail;
 441                 }
 442                 if (unlikely(qkey != qp->qkey)) {
 443                         /* XXX OK to lose a count once in a while. */
 444                         dev->qkey_violations++;
 445                         dev->n_pkt_drops++;
 446                         goto bail;
 447                 }
 448         } else if (hdr->lrh[1] == IB_LID_PERMISSIVE ||
 449                    hdr->lrh[3] == IB_LID_PERMISSIVE) {
 450                 struct ib_smp *smp = (struct ib_smp *) data;
 451
 452                 if (smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
 453                         dev->n_pkt_drops++;
 454                         goto bail;
 455                 }
 456         }
 457
 458         /* Get the number of bytes the message was padded by. */
 459         pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
 460         if (unlikely(tlen < (hdrsize + pad + 4))) {
 461                 /* Drop incomplete packets. */
 462                 dev->n_pkt_drops++;
 463                 goto bail;
 464         }
 465         tlen -= hdrsize + pad + 4;
 466
 467         /* Drop invalid MAD packets (see 13.5.3.1). */
 468         if (unlikely((qp->ibqp.qp_num == 0 &&
 469                       (tlen != 256 ||
 470                        (be16_to_cpu(hdr->lrh[0]) >> 12) != 15)) ||
 471                      (qp->ibqp.qp_num == 1 &&
 472                       (tlen != 256 ||
 473                        (be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))) {
 474                 dev->n_pkt_drops++;
 475                 goto bail;
 476         }
 477
 478         /*
 479          * A GRH is expected to preceed the data even if not
 480          * present on the wire.
 481          */
 482         wc.byte_len = tlen + sizeof(struct ib_grh);
 483
 484         /*
 485          * The opcode is in the low byte when its in network order
 486          * (top byte when in host order).
 487          */
 488         opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
 489         if (qp->ibqp.qp_num > 1 &&
 490             opcode == IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE) {
 491                 if (header_in_data) {
 492                         wc.imm_data = *(__be32 *) data;
 493                         data += sizeof(__be32);
 494                 } else
 495                         wc.imm_data = ohdr->u.ud.imm_data;
 496                 wc.wc_flags = IB_WC_WITH_IMM;
 497                 hdrsize += sizeof(u32);
 498         } else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
 499                 wc.imm_data = 0;
 500                 wc.wc_flags = 0;
 501         } else {
 502                 dev->n_pkt_drops++;
 503                 goto bail;
 504         }
 505
 506         /*
 507          * Get the next work request entry to find where to put the data.
 508          */
 509         if (qp->r_reuse_sge)
 510                 qp->r_reuse_sge = 0;
 511         else if (!ipath_get_rwqe(qp, 0)) {
 512                 /*
 513                  * Count VL15 packets dropped due to no receive buffer.
 514                  * Otherwise, count them as buffer overruns since usually,
 515                  * the HW will be able to receive packets even if there are
 516                  * no QPs with posted receive buffers.
 517                  */
 518                 if (qp->ibqp.qp_num == 0)
 519                         dev->n_vl15_dropped++;
 520                 else
 521                         dev->rcv_errors++;
 522                 goto bail;
 523         }
 524         /* Silently drop packets which are too big. */
 525         if (wc.byte_len > qp->r_len) {
 526                 qp->r_reuse_sge = 1;
 527                 dev->n_pkt_drops++;
 528                 goto bail;
 529         }
 530         if (has_grh) {
 531                 ipath_copy_sge(&qp->r_sge, &hdr->u.l.grh,
 532                                sizeof(struct ib_grh));
 533                 wc.wc_flags |= IB_WC_GRH;
 534         } else
 535                 ipath_skip_sge(&qp->r_sge, sizeof(struct ib_grh));
 536         ipath_copy_sge(&qp->r_sge, data,
 537                        wc.byte_len - sizeof(struct ib_grh));
 538         qp->r_wrid_valid = 0;
 539         wc.wr_id = qp->r_wr_id;
 540         wc.status = IB_WC_SUCCESS;
 541         wc.opcode = IB_WC_RECV;
 542         wc.vendor_err = 0;
 543         wc.qp = &qp->ibqp;
 544         wc.src_qp = src_qp;
 545         /* XXX do we know which pkey matched? Only needed for GSI. */
 546         wc.pkey_index = 0;
 547         wc.slid = be16_to_cpu(hdr->lrh[3]);
 548         wc.sl = (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF;
 549         dlid = be16_to_cpu(hdr->lrh[1]);
 550         /*
 551          * Save the LMC lower bits if the destination LID is a unicast LID.
 552          */
 553         wc.dlid_path_bits = dlid >= IPATH_MULTICAST_LID_BASE ? 0 :
 554                 dlid & ((1 << dev->dd->ipath_lmc) - 1);
 555         wc.port_num = 1;
 556         /* Signal completion event if the solicited bit is set. */
 557         ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 558                        (ohdr->bth[0] &
 559                         __constant_cpu_to_be32(1 << 23)) != 0);
 560
 561 bail:;
 562 }