drivers/infiniband/hw/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 <linux/sched.h>
  35 #include <rdma/ib_smi.h>
  36
  37 #include "ipath_verbs.h"
  38 #include "ipath_kernel.h"
  39
  40 /**
  41  * ipath_ud_loopback - handle send on loopback QPs
  42  * @sqp: the sending QP
  43  * @swqe: the send work request
  44  *
  45  * This is called from ipath_make_ud_req() to forward a WQE addressed
  46  * to the same HCA.
  47  * Note that the receive interrupt handler may be calling ipath_ud_rcv()
  48  * while this is being called.
  49  */
  50 static void ipath_ud_loopback(struct ipath_qp *sqp, struct ipath_swqe *swqe)
  51 {
  52         struct ipath_ibdev *dev = to_idev(sqp->ibqp.device);
  53         struct ipath_qp *qp;
  54         struct ib_ah_attr *ah_attr;
  55         unsigned long flags;
  56         struct ipath_rq *rq;
  57         struct ipath_srq *srq;
  58         struct ipath_sge_state rsge;
  59         struct ipath_sge *sge;
  60         struct ipath_rwq *wq;
  61         struct ipath_rwqe *wqe;
  62         void (*handler)(struct ib_event *, void *);
  63         struct ib_wc wc;
  64         u32 tail;
  65         u32 rlen;
  66         u32 length;
  67
  68         qp = ipath_lookup_qpn(&dev->qp_table, swqe->wr.wr.ud.remote_qpn);
  69         if (!qp || !(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK)) {
  70                 dev->n_pkt_drops++;
  71                 goto done;
  72         }
  73
  74         /*
  75          * Check that the qkey matches (except for QP0, see 9.6.1.4.1).
  76          * Qkeys with the high order bit set mean use the
  77          * qkey from the QP context instead of the WR (see 10.2.5).
  78          */
  79         if (unlikely(qp->ibqp.qp_num &&
  80                      ((int) swqe->wr.wr.ud.remote_qkey < 0 ?
  81                       sqp->qkey : swqe->wr.wr.ud.remote_qkey) != qp->qkey)) {
  82                 /* XXX OK to lose a count once in a while. */
  83                 dev->qkey_violations++;
  84                 dev->n_pkt_drops++;
  85                 goto drop;
  86         }
  87
  88         /*
  89          * A GRH is expected to precede the data even if not
  90          * present on the wire.
  91          */
  92         length = swqe->length;
  93         memset(&wc, 0, sizeof wc);
  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.ex.imm_data = swqe->wr.ex.imm_data;
  99         }
 100
 101         /*
 102          * This would be a lot simpler if we could call ipath_get_rwqe()
 103          * but that uses state that the receive interrupt handler uses
 104          * so we would need to lock out receive interrupts while doing
 105          * local loopback.
 106          */
 107         if (qp->ibqp.srq) {
 108                 srq = to_isrq(qp->ibqp.srq);
 109                 handler = srq->ibsrq.event_handler;
 110                 rq = &srq->rq;
 111         } else {
 112                 srq = NULL;
 113                 handler = NULL;
 114                 rq = &qp->r_rq;
 115         }
 116
 117         /*
 118          * Get the next work request entry to find where to put the data.
 119          * Note that it is safe to drop the lock after changing rq->tail
 120          * since ipath_post_receive() won't fill the empty slot.
 121          */
 122         spin_lock_irqsave(&rq->lock, flags);
 123         wq = rq->wq;
 124         tail = wq->tail;
 125         /* Validate tail before using it since it is user writable. */
 126         if (tail >= rq->size)
 127                 tail = 0;
 128         if (unlikely(tail == wq->head)) {
 129                 spin_unlock_irqrestore(&rq->lock, flags);
 130                 dev->n_pkt_drops++;
 131                 goto drop;
 132         }
 133         wqe = get_rwqe_ptr(rq, tail);
 134         rsge.sg_list = qp->r_ud_sg_list;
 135         if (!ipath_init_sge(qp, wqe, &rlen, &rsge)) {
 136                 spin_unlock_irqrestore(&rq->lock, flags);
 137                 dev->n_pkt_drops++;
 138                 goto drop;
 139         }
 140         /* Silently drop packets which are too big. */
 141         if (wc.byte_len > rlen) {
 142                 spin_unlock_irqrestore(&rq->lock, flags);
 143                 dev->n_pkt_drops++;
 144                 goto drop;
 145         }
 146         if (++tail >= rq->size)
 147                 tail = 0;
 148         wq->tail = tail;
 149         wc.wr_id = wqe->wr_id;
 150         if (handler) {
 151                 u32 n;
 152
 153                 /*
 154                  * validate head pointer value and compute
 155                  * the number of remaining WQEs.
 156                  */
 157                 n = wq->head;
 158                 if (n >= rq->size)
 159                         n = 0;
 160                 if (n < tail)
 161                         n += rq->size - tail;
 162                 else
 163                         n -= tail;
 164                 if (n < srq->limit) {
 165                         struct ib_event ev;
 166
 167                         srq->limit = 0;
 168                         spin_unlock_irqrestore(&rq->lock, flags);
 169                         ev.device = qp->ibqp.device;
 170                         ev.element.srq = qp->ibqp.srq;
 171                         ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
 172                         handler(&ev, srq->ibsrq.srq_context);
 173                 } else
 174                         spin_unlock_irqrestore(&rq->lock, flags);
 175         } else
 176                 spin_unlock_irqrestore(&rq->lock, flags);
 177
 178         ah_attr = &to_iah(swqe->wr.wr.ud.ah)->attr;
 179         if (ah_attr->ah_flags & IB_AH_GRH) {
 180                 ipath_copy_sge(&rsge, &ah_attr->grh, sizeof(struct ib_grh));
 181                 wc.wc_flags |= IB_WC_GRH;
 182         } else
 183                 ipath_skip_sge(&rsge, sizeof(struct ib_grh));
 184         sge = swqe->sg_list;
 185         while (length) {
 186                 u32 len = sge->length;
 187
 188                 if (len > length)
 189                         len = length;
 190                 if (len > sge->sge_length)
 191                         len = sge->sge_length;
 192                 BUG_ON(len == 0);
 193                 ipath_copy_sge(&rsge, sge->vaddr, len);
 194                 sge->vaddr += len;
 195                 sge->length -= len;
 196                 sge->sge_length -= len;
 197                 if (sge->sge_length == 0) {
 198                         if (--swqe->wr.num_sge)
 199                                 sge++;
 200                 } else if (sge->length == 0 && sge->mr != NULL) {
 201                         if (++sge->n >= IPATH_SEGSZ) {
 202                                 if (++sge->m >= sge->mr->mapsz)
 203                                         break;
 204                                 sge->n = 0;
 205                         }
 206                         sge->vaddr =
 207                                 sge->mr->map[sge->m]->segs[sge->n].vaddr;
 208                         sge->length =
 209                                 sge->mr->map[sge->m]->segs[sge->n].length;
 210                 }
 211                 length -= len;
 212         }
 213         wc.status = IB_WC_SUCCESS;
 214         wc.opcode = IB_WC_RECV;
 215         wc.qp = &qp->ibqp;
 216         wc.src_qp = sqp->ibqp.qp_num;
 217         /* XXX do we know which pkey matched? Only needed for GSI. */
 218         wc.pkey_index = 0;
 219         wc.slid = dev->dd->ipath_lid |
 220                 (ah_attr->src_path_bits &
 221                  ((1 << dev->dd->ipath_lmc) - 1));
 222         wc.sl = ah_attr->sl;
 223         wc.dlid_path_bits =
 224                 ah_attr->dlid & ((1 << dev->dd->ipath_lmc) - 1);
 225         wc.port_num = 1;
 226         /* Signal completion event if the solicited bit is set. */
 227         ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 228                        swqe->wr.send_flags & IB_SEND_SOLICITED);
 229 drop:
 230         if (atomic_dec_and_test(&qp->refcount))
 231                 wake_up(&qp->wait);
 232 done:;
 233 }
 234
 235 /**
 236  * ipath_make_ud_req - construct a UD request packet
 237  * @qp: the QP
 238  *
 239  * Return 1 if constructed; otherwise, return 0.
 240  */
 241 int ipath_make_ud_req(struct ipath_qp *qp)
 242 {
 243         struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
 244         struct ipath_other_headers *ohdr;
 245         struct ib_ah_attr *ah_attr;
 246         struct ipath_swqe *wqe;
 247         unsigned long flags;
 248         u32 nwords;
 249         u32 extra_bytes;
 250         u32 bth0;
 251         u16 lrh0;
 252         u16 lid;
 253         int ret = 0;
 254         int next_cur;
 255
 256         spin_lock_irqsave(&qp->s_lock, flags);
 257
 258         if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_NEXT_SEND_OK)) {
 259                 if (!(ib_ipath_state_ops[qp->state] & IPATH_FLUSH_SEND))
 260                         goto bail;
 261                 /* We are in the error state, flush the work request. */
 262                 if (qp->s_last == qp->s_head)
 263                         goto bail;
 264                 /* If DMAs are in progress, we can't flush immediately. */
 265                 if (atomic_read(&qp->s_dma_busy)) {
 266                         qp->s_flags |= IPATH_S_WAIT_DMA;
 267                         goto bail;
 268                 }
 269                 wqe = get_swqe_ptr(qp, qp->s_last);
 270                 ipath_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
 271                 goto done;
 272         }
 273
 274         if (qp->s_cur == qp->s_head)
 275                 goto bail;
 276
 277         wqe = get_swqe_ptr(qp, qp->s_cur);
 278         next_cur = qp->s_cur + 1;
 279         if (next_cur >= qp->s_size)
 280                 next_cur = 0;
 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 & ~((1 << dev->dd->ipath_lmc) - 1);
 292                 if (unlikely(lid == dev->dd->ipath_lid)) {
 293                         /*
 294                          * If DMAs are in progress, we can't generate
 295                          * a completion for the loopback packet since
 296                          * it would be out of order.
 297                          * XXX Instead of waiting, we could queue a
 298                          * zero length descriptor so we get a callback.
 299                          */
 300                         if (atomic_read(&qp->s_dma_busy)) {
 301                                 qp->s_flags |= IPATH_S_WAIT_DMA;
 302                                 goto bail;
 303                         }
 304                         qp->s_cur = next_cur;
 305                         spin_unlock_irqrestore(&qp->s_lock, flags);
 306                         ipath_ud_loopback(qp, wqe);
 307                         spin_lock_irqsave(&qp->s_lock, flags);
 308                         ipath_send_complete(qp, wqe, IB_WC_SUCCESS);
 309                         goto done;
 310                 }
 311         }
 312
 313         qp->s_cur = next_cur;
 314         extra_bytes = -wqe->length & 3;
 315         nwords = (wqe->length + extra_bytes) >> 2;
 316
 317         /* header size in 32-bit words LRH+BTH+DETH = (8+12+8)/4. */
 318         qp->s_hdrwords = 7;
 319         qp->s_cur_size = wqe->length;
 320         qp->s_cur_sge = &qp->s_sge;
 321         qp->s_dmult = ah_attr->static_rate;
 322         qp->s_wqe = wqe;
 323         qp->s_sge.sge = wqe->sg_list[0];
 324         qp->s_sge.sg_list = wqe->sg_list + 1;
 325         qp->s_sge.num_sge = wqe->wr.num_sge;
 326
 327         if (ah_attr->ah_flags & IB_AH_GRH) {
 328                 /* Header size in 32-bit words. */
 329                 qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
 330                                                  &ah_attr->grh,
 331                                                  qp->s_hdrwords, nwords);
 332                 lrh0 = IPATH_LRH_GRH;
 333                 ohdr = &qp->s_hdr.u.l.oth;
 334                 /*
 335                  * Don't worry about sending to locally attached multicast
 336                  * QPs.  It is unspecified by the spec. what happens.
 337                  */
 338         } else {
 339                 /* Header size in 32-bit words. */
 340                 lrh0 = IPATH_LRH_BTH;
 341                 ohdr = &qp->s_hdr.u.oth;
 342         }
 343         if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 344                 qp->s_hdrwords++;
 345                 ohdr->u.ud.imm_data = wqe->wr.ex.imm_data;
 346                 bth0 = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE << 24;
 347         } else
 348                 bth0 = IB_OPCODE_UD_SEND_ONLY << 24;
 349         lrh0 |= ah_attr->sl << 4;
 350         if (qp->ibqp.qp_type == IB_QPT_SMI)
 351                 lrh0 |= 0xF000; /* Set VL (see ch. 13.5.3.1) */
 352         qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
 353         qp->s_hdr.lrh[1] = cpu_to_be16(ah_attr->dlid);  /* DEST LID */
 354         qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords +
 355                                            SIZE_OF_CRC);
 356         lid = dev->dd->ipath_lid;
 357         if (lid) {
 358                 lid |= ah_attr->src_path_bits &
 359                         ((1 << dev->dd->ipath_lmc) - 1);
 360                 qp->s_hdr.lrh[3] = cpu_to_be16(lid);
 361         } else
 362                 qp->s_hdr.lrh[3] = IB_LID_PERMISSIVE;
 363         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 364                 bth0 |= 1 << 23;
 365         bth0 |= extra_bytes << 20;
 366         bth0 |= qp->ibqp.qp_type == IB_QPT_SMI ? IPATH_DEFAULT_P_KEY :
 367                 ipath_get_pkey(dev->dd, qp->s_pkey_index);
 368         ohdr->bth[0] = cpu_to_be32(bth0);
 369         /*
 370          * Use the multicast QP if the destination LID is a multicast LID.
 371          */
 372         ohdr->bth[1] = ah_attr->dlid >= IPATH_MULTICAST_LID_BASE &&
 373                 ah_attr->dlid != IPATH_PERMISSIVE_LID ?
 374                 cpu_to_be32(IPATH_MULTICAST_QPN) :
 375                 cpu_to_be32(wqe->wr.wr.ud.remote_qpn);
 376         ohdr->bth[2] = cpu_to_be32(qp->s_next_psn++ & IPATH_PSN_MASK);
 377         /*
 378          * Qkeys with the high order bit set mean use the
 379          * qkey from the QP context instead of the WR (see 10.2.5).
 380          */
 381         ohdr->u.ud.deth[0] = cpu_to_be32((int)wqe->wr.wr.ud.remote_qkey < 0 ?
 382                                          qp->qkey : wqe->wr.wr.ud.remote_qkey);
 383         ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);
 384
 385 done:
 386         ret = 1;
 387         goto unlock;
 388
 389 bail:
 390         qp->s_flags &= ~IPATH_S_BUSY;
 391 unlock:
 392         spin_unlock_irqrestore(&qp->s_lock, flags);
 393         return ret;
 394 }
 395
 396 /**
 397  * ipath_ud_rcv - receive an incoming UD packet
 398  * @dev: the device the packet came in on
 399  * @hdr: the packet header
 400  * @has_grh: true if the packet has a GRH
 401  * @data: the packet data
 402  * @tlen: the packet length
 403  * @qp: the QP the packet came on
 404  *
 405  * This is called from ipath_qp_rcv() to process an incoming UD packet
 406  * for the given QP.
 407  * Called at interrupt level.
 408  */
 409 void ipath_ud_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
 410                   int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
 411 {
 412         struct ipath_other_headers *ohdr;
 413         int opcode;
 414         u32 hdrsize;
 415         u32 pad;
 416         struct ib_wc wc;
 417         u32 qkey;
 418         u32 src_qp;
 419         u16 dlid;
 420         int header_in_data;
 421
 422         /* Check for GRH */
 423         if (!has_grh) {
 424                 ohdr = &hdr->u.oth;
 425                 hdrsize = 8 + 12 + 8;   /* LRH + BTH + DETH */
 426                 qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
 427                 src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
 428                 header_in_data = 0;
 429         } else {
 430                 ohdr = &hdr->u.l.oth;
 431                 hdrsize = 8 + 40 + 12 + 8; /* LRH + GRH + BTH + DETH */
 432                 /*
 433                  * The header with GRH is 68 bytes and the core driver sets
 434                  * the eager header buffer size to 56 bytes so the last 12
 435                  * bytes of the IB header is in the data buffer.
 436                  */
 437                 header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
 438                 if (header_in_data) {
 439                         qkey = be32_to_cpu(((__be32 *) data)[1]);
 440                         src_qp = be32_to_cpu(((__be32 *) data)[2]);
 441                         data += 12;
 442                 } else {
 443                         qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
 444                         src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
 445                 }
 446         }
 447         src_qp &= IPATH_QPN_MASK;
 448
 449         /*
 450          * Check that the permissive LID is only used on QP0
 451          * and the QKEY matches (see 9.6.1.4.1 and 9.6.1.5.1).
 452          */
 453         if (qp->ibqp.qp_num) {
 454                 if (unlikely(hdr->lrh[1] == IB_LID_PERMISSIVE ||
 455                              hdr->lrh[3] == IB_LID_PERMISSIVE)) {
 456                         dev->n_pkt_drops++;
 457                         goto bail;
 458                 }
 459                 if (unlikely(qkey != qp->qkey)) {
 460                         /* XXX OK to lose a count once in a while. */
 461                         dev->qkey_violations++;
 462                         dev->n_pkt_drops++;
 463                         goto bail;
 464                 }
 465         } else if (hdr->lrh[1] == IB_LID_PERMISSIVE ||
 466                    hdr->lrh[3] == IB_LID_PERMISSIVE) {
 467                 struct ib_smp *smp = (struct ib_smp *) data;
 468
 469                 if (smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
 470                         dev->n_pkt_drops++;
 471                         goto bail;
 472                 }
 473         }
 474
 475         /*
 476          * The opcode is in the low byte when its in network order
 477          * (top byte when in host order).
 478          */
 479         opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
 480         if (qp->ibqp.qp_num > 1 &&
 481             opcode == IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE) {
 482                 if (header_in_data) {
 483                         wc.ex.imm_data = *(__be32 *) data;
 484                         data += sizeof(__be32);
 485                 } else
 486                         wc.ex.imm_data = ohdr->u.ud.imm_data;
 487                 wc.wc_flags = IB_WC_WITH_IMM;
 488                 hdrsize += sizeof(u32);
 489         } else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
 490                 wc.ex.imm_data = 0;
 491                 wc.wc_flags = 0;
 492         } else {
 493                 dev->n_pkt_drops++;
 494                 goto bail;
 495         }
 496
 497         /* Get the number of bytes the message was padded by. */
 498         pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
 499         if (unlikely(tlen < (hdrsize + pad + 4))) {
 500                 /* Drop incomplete packets. */
 501                 dev->n_pkt_drops++;
 502                 goto bail;
 503         }
 504         tlen -= hdrsize + pad + 4;
 505
 506         /* Drop invalid MAD packets (see 13.5.3.1). */
 507         if (unlikely((qp->ibqp.qp_num == 0 &&
 508                       (tlen != 256 ||
 509                        (be16_to_cpu(hdr->lrh[0]) >> 12) != 15)) ||
 510                      (qp->ibqp.qp_num == 1 &&
 511                       (tlen != 256 ||
 512                        (be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))) {
 513                 dev->n_pkt_drops++;
 514                 goto bail;
 515         }
 516
 517         /*
 518          * A GRH is expected to precede the data even if not
 519          * present on the wire.
 520          */
 521         wc.byte_len = tlen + sizeof(struct ib_grh);
 522
 523         /*
 524          * Get the next work request entry to find where to put the data.
 525          */
 526         if (qp->r_flags & IPATH_R_REUSE_SGE)
 527                 qp->r_flags &= ~IPATH_R_REUSE_SGE;
 528         else if (!ipath_get_rwqe(qp, 0)) {
 529                 /*
 530                  * Count VL15 packets dropped due to no receive buffer.
 531                  * Otherwise, count them as buffer overruns since usually,
 532                  * the HW will be able to receive packets even if there are
 533                  * no QPs with posted receive buffers.
 534                  */
 535                 if (qp->ibqp.qp_num == 0)
 536                         dev->n_vl15_dropped++;
 537                 else
 538                         dev->rcv_errors++;
 539                 goto bail;
 540         }
 541         /* Silently drop packets which are too big. */
 542         if (wc.byte_len > qp->r_len) {
 543                 qp->r_flags |= IPATH_R_REUSE_SGE;
 544                 dev->n_pkt_drops++;
 545                 goto bail;
 546         }
 547         if (has_grh) {
 548                 ipath_copy_sge(&qp->r_sge, &hdr->u.l.grh,
 549                                sizeof(struct ib_grh));
 550                 wc.wc_flags |= IB_WC_GRH;
 551         } else
 552                 ipath_skip_sge(&qp->r_sge, sizeof(struct ib_grh));
 553         ipath_copy_sge(&qp->r_sge, data,
 554                        wc.byte_len - sizeof(struct ib_grh));
 555         if (!test_and_clear_bit(IPATH_R_WRID_VALID, &qp->r_aflags))
 556                 goto bail;
 557         wc.wr_id = qp->r_wr_id;
 558         wc.status = IB_WC_SUCCESS;
 559         wc.opcode = IB_WC_RECV;
 560         wc.vendor_err = 0;
 561         wc.qp = &qp->ibqp;
 562         wc.src_qp = src_qp;
 563         /* XXX do we know which pkey matched? Only needed for GSI. */
 564         wc.pkey_index = 0;
 565         wc.slid = be16_to_cpu(hdr->lrh[3]);
 566         wc.sl = (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF;
 567         dlid = be16_to_cpu(hdr->lrh[1]);
 568         /*
 569          * Save the LMC lower bits if the destination LID is a unicast LID.
 570          */
 571         wc.dlid_path_bits = dlid >= IPATH_MULTICAST_LID_BASE ? 0 :
 572                 dlid & ((1 << dev->dd->ipath_lmc) - 1);
 573         wc.port_num = 1;
 574         /* Signal completion event if the solicited bit is set. */
 575         ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 576                        (ohdr->bth[0] &
 577                         cpu_to_be32(1 << 23)) != 0);
 578
 579 bail:;
 580 }