drivers/staging/rdma/ipath/ipath_ud.c

   1 /*
   2  * Copyright (c) 2006, 2007, 2008 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->ud_wr.remote_qpn);
  68         if (!qp || !(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK)) {
  69                 dev->n_pkt_drops++;
  70                 goto done;
  71         }
  72
  73         /*
  74          * Check that the qkey matches (except for QP0, see 9.6.1.4.1).
  75          * Qkeys with the high order bit set mean use the
  76          * qkey from the QP context instead of the WR (see 10.2.5).
  77          */
  78         if (unlikely(qp->ibqp.qp_num &&
  79                      ((int) swqe->ud_wr.remote_qkey < 0 ?
  80                       sqp->qkey : swqe->ud_wr.remote_qkey) != qp->qkey)) {
  81                 /* XXX OK to lose a count once in a while. */
  82                 dev->qkey_violations++;
  83                 dev->n_pkt_drops++;
  84                 goto drop;
  85         }
  86
  87         /*
  88          * A GRH is expected to precede the data even if not
  89          * present on the wire.
  90          */
  91         length = swqe->length;
  92         memset(&wc, 0, sizeof wc);
  93         wc.byte_len = length + sizeof(struct ib_grh);
  94
  95         if (swqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
  96                 wc.wc_flags = IB_WC_WITH_IMM;
  97                 wc.ex.imm_data = swqe->wr.ex.imm_data;
  98         }
  99
 100         /*
 101          * This would be a lot simpler if we could call ipath_get_rwqe()
 102          * but that uses state that the receive interrupt handler uses
 103          * so we would need to lock out receive interrupts while doing
 104          * local loopback.
 105          */
 106         if (qp->ibqp.srq) {
 107                 srq = to_isrq(qp->ibqp.srq);
 108                 handler = srq->ibsrq.event_handler;
 109                 rq = &srq->rq;
 110         } else {
 111                 srq = NULL;
 112                 handler = NULL;
 113                 rq = &qp->r_rq;
 114         }
 115
 116         /*
 117          * Get the next work request entry to find where to put the data.
 118          * Note that it is safe to drop the lock after changing rq->tail
 119          * since ipath_post_receive() won't fill the empty slot.
 120          */
 121         spin_lock_irqsave(&rq->lock, flags);
 122         wq = rq->wq;
 123         tail = wq->tail;
 124         /* Validate tail before using it since it is user writable. */
 125         if (tail >= rq->size)
 126                 tail = 0;
 127         if (unlikely(tail == wq->head)) {
 128                 spin_unlock_irqrestore(&rq->lock, flags);
 129                 dev->n_pkt_drops++;
 130                 goto drop;
 131         }
 132         wqe = get_rwqe_ptr(rq, tail);
 133         rsge.sg_list = qp->r_ud_sg_list;
 134         if (!ipath_init_sge(qp, wqe, &rlen, &rsge)) {
 135                 spin_unlock_irqrestore(&rq->lock, flags);
 136                 dev->n_pkt_drops++;
 137                 goto drop;
 138         }
 139         /* Silently drop packets which are too big. */
 140         if (wc.byte_len > rlen) {
 141                 spin_unlock_irqrestore(&rq->lock, flags);
 142                 dev->n_pkt_drops++;
 143                 goto drop;
 144         }
 145         if (++tail >= rq->size)
 146                 tail = 0;
 147         wq->tail = tail;
 148         wc.wr_id = wqe->wr_id;
 149         if (handler) {
 150                 u32 n;
 151
 152                 /*
 153                  * validate head pointer value and compute
 154                  * the number of remaining WQEs.
 155                  */
 156                 n = wq->head;
 157                 if (n >= rq->size)
 158                         n = 0;
 159                 if (n < tail)
 160                         n += rq->size - tail;
 161                 else
 162                         n -= tail;
 163                 if (n < srq->limit) {
 164                         struct ib_event ev;
 165
 166                         srq->limit = 0;
 167                         spin_unlock_irqrestore(&rq->lock, flags);
 168                         ev.device = qp->ibqp.device;
 169                         ev.element.srq = qp->ibqp.srq;
 170                         ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
 171                         handler(&ev, srq->ibsrq.srq_context);
 172                 } else
 173                         spin_unlock_irqrestore(&rq->lock, flags);
 174         } else
 175                 spin_unlock_irqrestore(&rq->lock, flags);
 176
 177         ah_attr = &to_iah(swqe->ud_wr.ah)->attr;
 178         if (ah_attr->ah_flags & IB_AH_GRH) {
 179                 ipath_copy_sge(&rsge, &ah_attr->grh, sizeof(struct ib_grh));
 180                 wc.wc_flags |= IB_WC_GRH;
 181         } else
 182                 ipath_skip_sge(&rsge, sizeof(struct ib_grh));
 183         sge = swqe->sg_list;
 184         while (length) {
 185                 u32 len = sge->length;
 186
 187                 if (len > length)
 188                         len = length;
 189                 if (len > sge->sge_length)
 190                         len = sge->sge_length;
 191                 BUG_ON(len == 0);
 192                 ipath_copy_sge(&rsge, sge->vaddr, len);
 193                 sge->vaddr += len;
 194                 sge->length -= len;
 195                 sge->sge_length -= len;
 196                 if (sge->sge_length == 0) {
 197                         if (--swqe->wr.num_sge)
 198                                 sge++;
 199                 } else if (sge->length == 0 && sge->mr != NULL) {
 200                         if (++sge->n >= IPATH_SEGSZ) {
 201                                 if (++sge->m >= sge->mr->mapsz)
 202                                         break;
 203                                 sge->n = 0;
 204                         }
 205                         sge->vaddr =
 206                                 sge->mr->map[sge->m]->segs[sge->n].vaddr;
 207                         sge->length =
 208                                 sge->mr->map[sge->m]->segs[sge->n].length;
 209                 }
 210                 length -= len;
 211         }
 212         wc.status = IB_WC_SUCCESS;
 213         wc.opcode = IB_WC_RECV;
 214         wc.qp = &qp->ibqp;
 215         wc.src_qp = sqp->ibqp.qp_num;
 216         /* XXX do we know which pkey matched? Only needed for GSI. */
 217         wc.pkey_index = 0;
 218         wc.slid = dev->dd->ipath_lid |
 219                 (ah_attr->src_path_bits &
 220                  ((1 << dev->dd->ipath_lmc) - 1));
 221         wc.sl = ah_attr->sl;
 222         wc.dlid_path_bits =
 223                 ah_attr->dlid & ((1 << dev->dd->ipath_lmc) - 1);
 224         wc.port_num = 1;
 225         /* Signal completion event if the solicited bit is set. */
 226         ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 227                        swqe->ud_wr.wr.send_flags & IB_SEND_SOLICITED);
 228 drop:
 229         if (atomic_dec_and_test(&qp->refcount))
 230                 wake_up(&qp->wait);
 231 done:;
 232 }
 233
 234 /**
 235  * ipath_make_ud_req - construct a UD request packet
 236  * @qp: the QP
 237  *
 238  * Return 1 if constructed; otherwise, return 0.
 239  */
 240 int ipath_make_ud_req(struct ipath_qp *qp)
 241 {
 242         struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
 243         struct ipath_other_headers *ohdr;
 244         struct ib_ah_attr *ah_attr;
 245         struct ipath_swqe *wqe;
 246         unsigned long flags;
 247         u32 nwords;
 248         u32 extra_bytes;
 249         u32 bth0;
 250         u16 lrh0;
 251         u16 lid;
 252         int ret = 0;
 253         int next_cur;
 254
 255         spin_lock_irqsave(&qp->s_lock, flags);
 256
 257         if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_NEXT_SEND_OK)) {
 258                 if (!(ib_ipath_state_ops[qp->state] & IPATH_FLUSH_SEND))
 259                         goto bail;
 260                 /* We are in the error state, flush the work request. */
 261                 if (qp->s_last == qp->s_head)
 262                         goto bail;
 263                 /* If DMAs are in progress, we can't flush immediately. */
 264                 if (atomic_read(&qp->s_dma_busy)) {
 265                         qp->s_flags |= IPATH_S_WAIT_DMA;
 266                         goto bail;
 267                 }
 268                 wqe = get_swqe_ptr(qp, qp->s_last);
 269                 ipath_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
 270                 goto done;
 271         }
 272
 273         if (qp->s_cur == qp->s_head)
 274                 goto bail;
 275
 276         wqe = get_swqe_ptr(qp, qp->s_cur);
 277         next_cur = qp->s_cur + 1;
 278         if (next_cur >= qp->s_size)
 279                 next_cur = 0;
 280
 281         /* Construct the header. */
 282         ah_attr = &to_iah(wqe->ud_wr.ah)->attr;
 283         if (ah_attr->dlid >= IPATH_MULTICAST_LID_BASE) {
 284                 if (ah_attr->dlid != IPATH_PERMISSIVE_LID)
 285                         dev->n_multicast_xmit++;
 286                 else
 287                         dev->n_unicast_xmit++;
 288         } else {
 289                 dev->n_unicast_xmit++;
 290                 lid = ah_attr->dlid & ~((1 << dev->dd->ipath_lmc) - 1);
 291                 if (unlikely(lid == dev->dd->ipath_lid)) {
 292                         /*
 293                          * If DMAs are in progress, we can't generate
 294                          * a completion for the loopback packet since
 295                          * it would be out of order.
 296                          * XXX Instead of waiting, we could queue a
 297                          * zero length descriptor so we get a callback.
 298                          */
 299                         if (atomic_read(&qp->s_dma_busy)) {
 300                                 qp->s_flags |= IPATH_S_WAIT_DMA;
 301                                 goto bail;
 302                         }
 303                         qp->s_cur = next_cur;
 304                         spin_unlock_irqrestore(&qp->s_lock, flags);
 305                         ipath_ud_loopback(qp, wqe);
 306                         spin_lock_irqsave(&qp->s_lock, flags);
 307                         ipath_send_complete(qp, wqe, IB_WC_SUCCESS);
 308                         goto done;
 309                 }
 310         }
 311
 312         qp->s_cur = next_cur;
 313         extra_bytes = -wqe->length & 3;
 314         nwords = (wqe->length + extra_bytes) >> 2;
 315
 316         /* header size in 32-bit words LRH+BTH+DETH = (8+12+8)/4. */
 317         qp->s_hdrwords = 7;
 318         qp->s_cur_size = wqe->length;
 319         qp->s_cur_sge = &qp->s_sge;
 320         qp->s_dmult = ah_attr->static_rate;
 321         qp->s_wqe = wqe;
 322         qp->s_sge.sge = wqe->sg_list[0];
 323         qp->s_sge.sg_list = wqe->sg_list + 1;
 324         qp->s_sge.num_sge = wqe->ud_wr.wr.num_sge;
 325
 326         if (ah_attr->ah_flags & IB_AH_GRH) {
 327                 /* Header size in 32-bit words. */
 328                 qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
 329                                                  &ah_attr->grh,
 330                                                  qp->s_hdrwords, nwords);
 331                 lrh0 = IPATH_LRH_GRH;
 332                 ohdr = &qp->s_hdr.u.l.oth;
 333                 /*
 334                  * Don't worry about sending to locally attached multicast
 335                  * QPs.  It is unspecified by the spec. what happens.
 336                  */
 337         } else {
 338                 /* Header size in 32-bit words. */
 339                 lrh0 = IPATH_LRH_BTH;
 340                 ohdr = &qp->s_hdr.u.oth;
 341         }
 342         if (wqe->ud_wr.wr.opcode == IB_WR_SEND_WITH_IMM) {
 343                 qp->s_hdrwords++;
 344                 ohdr->u.ud.imm_data = wqe->ud_wr.wr.ex.imm_data;
 345                 bth0 = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE << 24;
 346         } else
 347                 bth0 = IB_OPCODE_UD_SEND_ONLY << 24;
 348         lrh0 |= ah_attr->sl << 4;
 349         if (qp->ibqp.qp_type == IB_QPT_SMI)
 350                 lrh0 |= 0xF000; /* Set VL (see ch. 13.5.3.1) */
 351         qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
 352         qp->s_hdr.lrh[1] = cpu_to_be16(ah_attr->dlid);  /* DEST LID */
 353         qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords +
 354                                            SIZE_OF_CRC);
 355         lid = dev->dd->ipath_lid;
 356         if (lid) {
 357                 lid |= ah_attr->src_path_bits &
 358                         ((1 << dev->dd->ipath_lmc) - 1);
 359                 qp->s_hdr.lrh[3] = cpu_to_be16(lid);
 360         } else
 361                 qp->s_hdr.lrh[3] = IB_LID_PERMISSIVE;
 362         if (wqe->ud_wr.wr.send_flags & IB_SEND_SOLICITED)
 363                 bth0 |= 1 << 23;
 364         bth0 |= extra_bytes << 20;
 365         bth0 |= qp->ibqp.qp_type == IB_QPT_SMI ? IPATH_DEFAULT_P_KEY :
 366                 ipath_get_pkey(dev->dd, qp->s_pkey_index);
 367         ohdr->bth[0] = cpu_to_be32(bth0);
 368         /*
 369          * Use the multicast QP if the destination LID is a multicast LID.
 370          */
 371         ohdr->bth[1] = ah_attr->dlid >= IPATH_MULTICAST_LID_BASE &&
 372                 ah_attr->dlid != IPATH_PERMISSIVE_LID ?
 373                 cpu_to_be32(IPATH_MULTICAST_QPN) :
 374                 cpu_to_be32(wqe->ud_wr.remote_qpn);
 375         ohdr->bth[2] = cpu_to_be32(qp->s_next_psn++ & IPATH_PSN_MASK);
 376         /*
 377          * Qkeys with the high order bit set mean use the
 378          * qkey from the QP context instead of the WR (see 10.2.5).
 379          */
 380         ohdr->u.ud.deth[0] = cpu_to_be32((int)wqe->ud_wr.remote_qkey < 0 ?
 381                                          qp->qkey : wqe->ud_wr.remote_qkey);
 382         ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);
 383
 384 done:
 385         ret = 1;
 386         goto unlock;
 387
 388 bail:
 389         qp->s_flags &= ~IPATH_S_BUSY;
 390 unlock:
 391         spin_unlock_irqrestore(&qp->s_lock, flags);
 392         return ret;
 393 }
 394
 395 /**
 396  * ipath_ud_rcv - receive an incoming UD packet
 397  * @dev: the device the packet came in on
 398  * @hdr: the packet header
 399  * @has_grh: true if the packet has a GRH
 400  * @data: the packet data
 401  * @tlen: the packet length
 402  * @qp: the QP the packet came on
 403  *
 404  * This is called from ipath_qp_rcv() to process an incoming UD packet
 405  * for the given QP.
 406  * Called at interrupt level.
 407  */
 408 void ipath_ud_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
 409                   int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
 410 {
 411         struct ipath_other_headers *ohdr;
 412         int opcode;
 413         u32 hdrsize;
 414         u32 pad;
 415         struct ib_wc wc;
 416         u32 qkey;
 417         u32 src_qp;
 418         u16 dlid;
 419         int header_in_data;
 420
 421         /* Check for GRH */
 422         if (!has_grh) {
 423                 ohdr = &hdr->u.oth;
 424                 hdrsize = 8 + 12 + 8;   /* LRH + BTH + DETH */
 425                 qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
 426                 src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
 427                 header_in_data = 0;
 428         } else {
 429                 ohdr = &hdr->u.l.oth;
 430                 hdrsize = 8 + 40 + 12 + 8; /* LRH + GRH + BTH + DETH */
 431                 /*
 432                  * The header with GRH is 68 bytes and the core driver sets
 433                  * the eager header buffer size to 56 bytes so the last 12
 434                  * bytes of the IB header is in the data buffer.
 435                  */
 436                 header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
 437                 if (header_in_data) {
 438                         qkey = be32_to_cpu(((__be32 *) data)[1]);
 439                         src_qp = be32_to_cpu(((__be32 *) data)[2]);
 440                         data += 12;
 441                 } else {
 442                         qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
 443                         src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
 444                 }
 445         }
 446         src_qp &= IPATH_QPN_MASK;
 447
 448         /*
 449          * Check that the permissive LID is only used on QP0
 450          * and the QKEY matches (see 9.6.1.4.1 and 9.6.1.5.1).
 451          */
 452         if (qp->ibqp.qp_num) {
 453                 if (unlikely(hdr->lrh[1] == IB_LID_PERMISSIVE ||
 454                              hdr->lrh[3] == IB_LID_PERMISSIVE)) {
 455                         dev->n_pkt_drops++;
 456                         goto bail;
 457                 }
 458                 if (unlikely(qkey != qp->qkey)) {
 459                         /* XXX OK to lose a count once in a while. */
 460                         dev->qkey_violations++;
 461                         dev->n_pkt_drops++;
 462                         goto bail;
 463                 }
 464         } else if (hdr->lrh[1] == IB_LID_PERMISSIVE ||
 465                    hdr->lrh[3] == IB_LID_PERMISSIVE) {
 466                 struct ib_smp *smp = (struct ib_smp *) data;
 467
 468                 if (smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
 469                         dev->n_pkt_drops++;
 470                         goto bail;
 471                 }
 472         }
 473
 474         /*
 475          * The opcode is in the low byte when its in network order
 476          * (top byte when in host order).
 477          */
 478         opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
 479         if (qp->ibqp.qp_num > 1 &&
 480             opcode == IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE) {
 481                 if (header_in_data) {
 482                         wc.ex.imm_data = *(__be32 *) data;
 483                         data += sizeof(__be32);
 484                 } else
 485                         wc.ex.imm_data = ohdr->u.ud.imm_data;
 486                 wc.wc_flags = IB_WC_WITH_IMM;
 487                 hdrsize += sizeof(u32);
 488         } else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
 489                 wc.ex.imm_data = 0;
 490                 wc.wc_flags = 0;
 491         } else {
 492                 dev->n_pkt_drops++;
 493                 goto bail;
 494         }
 495
 496         /* Get the number of bytes the message was padded by. */
 497         pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
 498         if (unlikely(tlen < (hdrsize + pad + 4))) {
 499                 /* Drop incomplete packets. */
 500                 dev->n_pkt_drops++;
 501                 goto bail;
 502         }
 503         tlen -= hdrsize + pad + 4;
 504
 505         /* Drop invalid MAD packets (see 13.5.3.1). */
 506         if (unlikely((qp->ibqp.qp_num == 0 &&
 507                       (tlen != 256 ||
 508                        (be16_to_cpu(hdr->lrh[0]) >> 12) != 15)) ||
 509                      (qp->ibqp.qp_num == 1 &&
 510                       (tlen != 256 ||
 511                        (be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))) {
 512                 dev->n_pkt_drops++;
 513                 goto bail;
 514         }
 515
 516         /*
 517          * A GRH is expected to precede the data even if not
 518          * present on the wire.
 519          */
 520         wc.byte_len = tlen + sizeof(struct ib_grh);
 521
 522         /*
 523          * Get the next work request entry to find where to put the data.
 524          */
 525         if (qp->r_flags & IPATH_R_REUSE_SGE)
 526                 qp->r_flags &= ~IPATH_R_REUSE_SGE;
 527         else if (!ipath_get_rwqe(qp, 0)) {
 528                 /*
 529                  * Count VL15 packets dropped due to no receive buffer.
 530                  * Otherwise, count them as buffer overruns since usually,
 531                  * the HW will be able to receive packets even if there are
 532                  * no QPs with posted receive buffers.
 533                  */
 534                 if (qp->ibqp.qp_num == 0)
 535                         dev->n_vl15_dropped++;
 536                 else
 537                         dev->rcv_errors++;
 538                 goto bail;
 539         }
 540         /* Silently drop packets which are too big. */
 541         if (wc.byte_len > qp->r_len) {
 542                 qp->r_flags |= IPATH_R_REUSE_SGE;
 543                 dev->n_pkt_drops++;
 544                 goto bail;
 545         }
 546         if (has_grh) {
 547                 ipath_copy_sge(&qp->r_sge, &hdr->u.l.grh,
 548                                sizeof(struct ib_grh));
 549                 wc.wc_flags |= IB_WC_GRH;
 550         } else
 551                 ipath_skip_sge(&qp->r_sge, sizeof(struct ib_grh));
 552         ipath_copy_sge(&qp->r_sge, data,
 553                        wc.byte_len - sizeof(struct ib_grh));
 554         if (!test_and_clear_bit(IPATH_R_WRID_VALID, &qp->r_aflags))
 555                 goto bail;
 556         wc.wr_id = qp->r_wr_id;
 557         wc.status = IB_WC_SUCCESS;
 558         wc.opcode = IB_WC_RECV;
 559         wc.vendor_err = 0;
 560         wc.qp = &qp->ibqp;
 561         wc.src_qp = src_qp;
 562         /* XXX do we know which pkey matched? Only needed for GSI. */
 563         wc.pkey_index = 0;
 564         wc.slid = be16_to_cpu(hdr->lrh[3]);
 565         wc.sl = (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF;
 566         dlid = be16_to_cpu(hdr->lrh[1]);
 567         /*
 568          * Save the LMC lower bits if the destination LID is a unicast LID.
 569          */
 570         wc.dlid_path_bits = dlid >= IPATH_MULTICAST_LID_BASE ? 0 :
 571                 dlid & ((1 << dev->dd->ipath_lmc) - 1);
 572         wc.port_num = 1;
 573         /* Signal completion event if the solicited bit is set. */
 574         ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 575                        (ohdr->bth[0] &
 576                         cpu_to_be32(1 << 23)) != 0);
 577
 578 bail:;
 579 }