drivers/infiniband/hw/qib/qib_ud.c

   1 /*
   2  * Copyright (c) 2012 - 2019 Intel Corporation.  All rights reserved.
   3  * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
   4  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * OpenIB.org BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  */
  34
  35 #include <rdma/ib_smi.h>
  36 #include <rdma/ib_verbs.h>
  37
  38 #include "qib.h"
  39 #include "qib_mad.h"
  40
  41 /**
  42  * qib_ud_loopback - handle send on loopback QPs
  43  * @sqp: the sending QP
  44  * @swqe: the send work request
  45  *
  46  * This is called from qib_make_ud_req() to forward a WQE addressed
  47  * to the same HCA.
  48  * Note that the receive interrupt handler may be calling qib_ud_rcv()
  49  * while this is being called.
  50  */
  51 static void qib_ud_loopback(struct rvt_qp *sqp, struct rvt_swqe *swqe)
  52 {
  53         struct qib_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
  54         struct qib_pportdata *ppd = ppd_from_ibp(ibp);
  55         struct qib_devdata *dd = ppd->dd;
  56         struct rvt_dev_info *rdi = &dd->verbs_dev.rdi;
  57         struct rvt_qp *qp;
  58         struct rdma_ah_attr *ah_attr;
  59         unsigned long flags;
  60         struct rvt_sge_state ssge;
  61         struct rvt_sge *sge;
  62         struct ib_wc wc;
  63         u32 length;
  64         enum ib_qp_type sqptype, dqptype;
  65
  66         rcu_read_lock();
  67         qp = rvt_lookup_qpn(rdi, &ibp->rvp, rvt_get_swqe_remote_qpn(swqe));
  68         if (!qp) {
  69                 ibp->rvp.n_pkt_drops++;
  70                 goto drop;
  71         }
  72
  73         sqptype = sqp->ibqp.qp_type == IB_QPT_GSI ?
  74                         IB_QPT_UD : sqp->ibqp.qp_type;
  75         dqptype = qp->ibqp.qp_type == IB_QPT_GSI ?
  76                         IB_QPT_UD : qp->ibqp.qp_type;
  77
  78         if (dqptype != sqptype ||
  79             !(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
  80                 ibp->rvp.n_pkt_drops++;
  81                 goto drop;
  82         }
  83
  84         ah_attr = rvt_get_swqe_ah_attr(swqe);
  85         ppd = ppd_from_ibp(ibp);
  86
  87         if (qp->ibqp.qp_num > 1) {
  88                 u16 pkey1;
  89                 u16 pkey2;
  90                 u16 lid;
  91
  92                 pkey1 = qib_get_pkey(ibp, sqp->s_pkey_index);
  93                 pkey2 = qib_get_pkey(ibp, qp->s_pkey_index);
  94                 if (unlikely(!qib_pkey_ok(pkey1, pkey2))) {
  95                         lid = ppd->lid | (rdma_ah_get_path_bits(ah_attr) &
  96                                           ((1 << ppd->lmc) - 1));
  97                         qib_bad_pkey(ibp, pkey1,
  98                                      rdma_ah_get_sl(ah_attr),
  99                                      sqp->ibqp.qp_num, qp->ibqp.qp_num,
 100                                      cpu_to_be16(lid),
 101                                      cpu_to_be16(rdma_ah_get_dlid(ah_attr)));
 102                         goto drop;
 103                 }
 104         }
 105
 106         /*
 107          * Check that the qkey matches (except for QP0, see 9.6.1.4.1).
 108          * Qkeys with the high order bit set mean use the
 109          * qkey from the QP context instead of the WR (see 10.2.5).
 110          */
 111         if (qp->ibqp.qp_num) {
 112                 u32 qkey;
 113
 114                 qkey = (int)rvt_get_swqe_remote_qkey(swqe) < 0 ?
 115                         sqp->qkey : rvt_get_swqe_remote_qkey(swqe);
 116                 if (unlikely(qkey != qp->qkey))
 117                         goto drop;
 118         }
 119
 120         /*
 121          * A GRH is expected to precede the data even if not
 122          * present on the wire.
 123          */
 124         length = swqe->length;
 125         memset(&wc, 0, sizeof(wc));
 126         wc.byte_len = length + sizeof(struct ib_grh);
 127
 128         if (swqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 129                 wc.wc_flags = IB_WC_WITH_IMM;
 130                 wc.ex.imm_data = swqe->wr.ex.imm_data;
 131         }
 132
 133         spin_lock_irqsave(&qp->r_lock, flags);
 134
 135         /*
 136          * Get the next work request entry to find where to put the data.
 137          */
 138         if (qp->r_flags & RVT_R_REUSE_SGE)
 139                 qp->r_flags &= ~RVT_R_REUSE_SGE;
 140         else {
 141                 int ret;
 142
 143                 ret = rvt_get_rwqe(qp, false);
 144                 if (ret < 0) {
 145                         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
 146                         goto bail_unlock;
 147                 }
 148                 if (!ret) {
 149                         if (qp->ibqp.qp_num == 0)
 150                                 ibp->rvp.n_vl15_dropped++;
 151                         goto bail_unlock;
 152                 }
 153         }
 154         /* Silently drop packets which are too big. */
 155         if (unlikely(wc.byte_len > qp->r_len)) {
 156                 qp->r_flags |= RVT_R_REUSE_SGE;
 157                 ibp->rvp.n_pkt_drops++;
 158                 goto bail_unlock;
 159         }
 160
 161         if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
 162                 struct ib_grh grh;
 163                 const struct ib_global_route *grd = rdma_ah_read_grh(ah_attr);
 164
 165                 qib_make_grh(ibp, &grh, grd, 0, 0);
 166                 rvt_copy_sge(qp, &qp->r_sge, &grh,
 167                              sizeof(grh), true, false);
 168                 wc.wc_flags |= IB_WC_GRH;
 169         } else
 170                 rvt_skip_sge(&qp->r_sge, sizeof(struct ib_grh), true);
 171         ssge.sg_list = swqe->sg_list + 1;
 172         ssge.sge = *swqe->sg_list;
 173         ssge.num_sge = swqe->wr.num_sge;
 174         sge = &ssge.sge;
 175         while (length) {
 176                 u32 len = rvt_get_sge_length(sge, length);
 177
 178                 rvt_copy_sge(qp, &qp->r_sge, sge->vaddr, len, true, false);
 179                 sge->vaddr += len;
 180                 sge->length -= len;
 181                 sge->sge_length -= len;
 182                 if (sge->sge_length == 0) {
 183                         if (--ssge.num_sge)
 184                                 *sge = *ssge.sg_list++;
 185                 } else if (sge->length == 0 && sge->mr->lkey) {
 186                         if (++sge->n >= RVT_SEGSZ) {
 187                                 if (++sge->m >= sge->mr->mapsz)
 188                                         break;
 189                                 sge->n = 0;
 190                         }
 191                         sge->vaddr =
 192                                 sge->mr->map[sge->m]->segs[sge->n].vaddr;
 193                         sge->length =
 194                                 sge->mr->map[sge->m]->segs[sge->n].length;
 195                 }
 196                 length -= len;
 197         }
 198         rvt_put_ss(&qp->r_sge);
 199         if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
 200                 goto bail_unlock;
 201         wc.wr_id = qp->r_wr_id;
 202         wc.status = IB_WC_SUCCESS;
 203         wc.opcode = IB_WC_RECV;
 204         wc.qp = &qp->ibqp;
 205         wc.src_qp = sqp->ibqp.qp_num;
 206         wc.pkey_index = qp->ibqp.qp_type == IB_QPT_GSI ?
 207                 rvt_get_swqe_pkey_index(swqe) : 0;
 208         wc.slid = ppd->lid | (rdma_ah_get_path_bits(ah_attr) &
 209                                 ((1 << ppd->lmc) - 1));
 210         wc.sl = rdma_ah_get_sl(ah_attr);
 211         wc.dlid_path_bits = rdma_ah_get_dlid(ah_attr) & ((1 << ppd->lmc) - 1);
 212         wc.port_num = qp->port_num;
 213         /* Signal completion event if the solicited bit is set. */
 214         rvt_recv_cq(qp, &wc, swqe->wr.send_flags & IB_SEND_SOLICITED);
 215         ibp->rvp.n_loop_pkts++;
 216 bail_unlock:
 217         spin_unlock_irqrestore(&qp->r_lock, flags);
 218 drop:
 219         rcu_read_unlock();
 220 }
 221
 222 /**
 223  * qib_make_ud_req - construct a UD request packet
 224  * @qp: the QP
 225  *
 226  * Assumes the s_lock is held.
 227  *
 228  * Return 1 if constructed; otherwise, return 0.
 229  */
 230 int qib_make_ud_req(struct rvt_qp *qp, unsigned long *flags)
 231 {
 232         struct qib_qp_priv *priv = qp->priv;
 233         struct ib_other_headers *ohdr;
 234         struct rdma_ah_attr *ah_attr;
 235         struct qib_pportdata *ppd;
 236         struct qib_ibport *ibp;
 237         struct rvt_swqe *wqe;
 238         u32 nwords;
 239         u32 extra_bytes;
 240         u32 bth0;
 241         u16 lrh0;
 242         u16 lid;
 243         int ret = 0;
 244         int next_cur;
 245
 246         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK)) {
 247                 if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
 248                         goto bail;
 249                 /* We are in the error state, flush the work request. */
 250                 if (qp->s_last == READ_ONCE(qp->s_head))
 251                         goto bail;
 252                 /* If DMAs are in progress, we can't flush immediately. */
 253                 if (atomic_read(&priv->s_dma_busy)) {
 254                         qp->s_flags |= RVT_S_WAIT_DMA;
 255                         goto bail;
 256                 }
 257                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
 258                 rvt_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
 259                 goto done;
 260         }
 261
 262         /* see post_one_send() */
 263         if (qp->s_cur == READ_ONCE(qp->s_head))
 264                 goto bail;
 265
 266         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
 267         next_cur = qp->s_cur + 1;
 268         if (next_cur >= qp->s_size)
 269                 next_cur = 0;
 270
 271         /* Construct the header. */
 272         ibp = to_iport(qp->ibqp.device, qp->port_num);
 273         ppd = ppd_from_ibp(ibp);
 274         ah_attr = rvt_get_swqe_ah_attr(wqe);
 275         if (rdma_ah_get_dlid(ah_attr) >= be16_to_cpu(IB_MULTICAST_LID_BASE)) {
 276                 if (rdma_ah_get_dlid(ah_attr) !=
 277                                 be16_to_cpu(IB_LID_PERMISSIVE))
 278                         this_cpu_inc(ibp->pmastats->n_multicast_xmit);
 279                 else
 280                         this_cpu_inc(ibp->pmastats->n_unicast_xmit);
 281         } else {
 282                 this_cpu_inc(ibp->pmastats->n_unicast_xmit);
 283                 lid = rdma_ah_get_dlid(ah_attr) & ~((1 << ppd->lmc) - 1);
 284                 if (unlikely(lid == ppd->lid)) {
 285                         unsigned long tflags = *flags;
 286                         /*
 287                          * If DMAs are in progress, we can't generate
 288                          * a completion for the loopback packet since
 289                          * it would be out of order.
 290                          * XXX Instead of waiting, we could queue a
 291                          * zero length descriptor so we get a callback.
 292                          */
 293                         if (atomic_read(&priv->s_dma_busy)) {
 294                                 qp->s_flags |= RVT_S_WAIT_DMA;
 295                                 goto bail;
 296                         }
 297                         qp->s_cur = next_cur;
 298                         spin_unlock_irqrestore(&qp->s_lock, tflags);
 299                         qib_ud_loopback(qp, wqe);
 300                         spin_lock_irqsave(&qp->s_lock, tflags);
 301                         *flags = tflags;
 302                         rvt_send_complete(qp, wqe, IB_WC_SUCCESS);
 303                         goto done;
 304                 }
 305         }
 306
 307         qp->s_cur = next_cur;
 308         extra_bytes = -wqe->length & 3;
 309         nwords = (wqe->length + extra_bytes) >> 2;
 310
 311         /* header size in 32-bit words LRH+BTH+DETH = (8+12+8)/4. */
 312         qp->s_hdrwords = 7;
 313         qp->s_cur_size = wqe->length;
 314         qp->s_cur_sge = &qp->s_sge;
 315         qp->s_srate = rdma_ah_get_static_rate(ah_attr);
 316         qp->s_wqe = wqe;
 317         qp->s_sge.sge = wqe->sg_list[0];
 318         qp->s_sge.sg_list = wqe->sg_list + 1;
 319         qp->s_sge.num_sge = wqe->wr.num_sge;
 320         qp->s_sge.total_len = wqe->length;
 321
 322         if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
 323                 /* Header size in 32-bit words. */
 324                 qp->s_hdrwords += qib_make_grh(ibp, &priv->s_hdr->u.l.grh,
 325                                                rdma_ah_read_grh(ah_attr),
 326                                                qp->s_hdrwords, nwords);
 327                 lrh0 = QIB_LRH_GRH;
 328                 ohdr = &priv->s_hdr->u.l.oth;
 329                 /*
 330                  * Don't worry about sending to locally attached multicast
 331                  * QPs.  It is unspecified by the spec. what happens.
 332                  */
 333         } else {
 334                 /* Header size in 32-bit words. */
 335                 lrh0 = QIB_LRH_BTH;
 336                 ohdr = &priv->s_hdr->u.oth;
 337         }
 338         if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 339                 qp->s_hdrwords++;
 340                 ohdr->u.ud.imm_data = wqe->wr.ex.imm_data;
 341                 bth0 = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE << 24;
 342         } else
 343                 bth0 = IB_OPCODE_UD_SEND_ONLY << 24;
 344         lrh0 |= rdma_ah_get_sl(ah_attr) << 4;
 345         if (qp->ibqp.qp_type == IB_QPT_SMI)
 346                 lrh0 |= 0xF000; /* Set VL (see ch. 13.5.3.1) */
 347         else
 348                 lrh0 |= ibp->sl_to_vl[rdma_ah_get_sl(ah_attr)] << 12;
 349         priv->s_hdr->lrh[0] = cpu_to_be16(lrh0);
 350         priv->s_hdr->lrh[1] =
 351                         cpu_to_be16(rdma_ah_get_dlid(ah_attr));  /* DEST LID */
 352         priv->s_hdr->lrh[2] =
 353                         cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
 354         lid = ppd->lid;
 355         if (lid) {
 356                 lid |= rdma_ah_get_path_bits(ah_attr) &
 357                         ((1 << ppd->lmc) - 1);
 358                 priv->s_hdr->lrh[3] = cpu_to_be16(lid);
 359         } else
 360                 priv->s_hdr->lrh[3] = IB_LID_PERMISSIVE;
 361         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 362                 bth0 |= IB_BTH_SOLICITED;
 363         bth0 |= extra_bytes << 20;
 364         bth0 |= qp->ibqp.qp_type == IB_QPT_SMI ? QIB_DEFAULT_P_KEY :
 365                 qib_get_pkey(ibp, qp->ibqp.qp_type == IB_QPT_GSI ?
 366                              rvt_get_swqe_pkey_index(wqe) : 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] = rdma_ah_get_dlid(ah_attr) >=
 372                         be16_to_cpu(IB_MULTICAST_LID_BASE) &&
 373                 rdma_ah_get_dlid(ah_attr) != be16_to_cpu(IB_LID_PERMISSIVE) ?
 374                 cpu_to_be32(QIB_MULTICAST_QPN) :
 375                 cpu_to_be32(rvt_get_swqe_remote_qpn(wqe));
 376         ohdr->bth[2] = cpu_to_be32(wqe->psn & QIB_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] =
 382                 cpu_to_be32((int)rvt_get_swqe_remote_qkey(wqe) < 0 ? qp->qkey :
 383                             rvt_get_swqe_remote_qkey(wqe));
 384         ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);
 385
 386 done:
 387         return 1;
 388 bail:
 389         qp->s_flags &= ~RVT_S_BUSY;
 390         return ret;
 391 }
 392
 393 static unsigned qib_lookup_pkey(struct qib_ibport *ibp, u16 pkey)
 394 {
 395         struct qib_pportdata *ppd = ppd_from_ibp(ibp);
 396         struct qib_devdata *dd = ppd->dd;
 397         unsigned ctxt = ppd->hw_pidx;
 398         unsigned i;
 399
 400         pkey &= 0x7fff; /* remove limited/full membership bit */
 401
 402         for (i = 0; i < ARRAY_SIZE(dd->rcd[ctxt]->pkeys); ++i)
 403                 if ((dd->rcd[ctxt]->pkeys[i] & 0x7fff) == pkey)
 404                         return i;
 405
 406         /*
 407          * Should not get here, this means hardware failed to validate pkeys.
 408          * Punt and return index 0.
 409          */
 410         return 0;
 411 }
 412
 413 /**
 414  * qib_ud_rcv - receive an incoming UD packet
 415  * @ibp: the port the packet came in on
 416  * @hdr: the packet header
 417  * @has_grh: true if the packet has a GRH
 418  * @data: the packet data
 419  * @tlen: the packet length
 420  * @qp: the QP the packet came on
 421  *
 422  * This is called from qib_qp_rcv() to process an incoming UD packet
 423  * for the given QP.
 424  * Called at interrupt level.
 425  */
 426 void qib_ud_rcv(struct qib_ibport *ibp, struct ib_header *hdr,
 427                 int has_grh, void *data, u32 tlen, struct rvt_qp *qp)
 428 {
 429         struct ib_other_headers *ohdr;
 430         int opcode;
 431         u32 hdrsize;
 432         u32 pad;
 433         struct ib_wc wc;
 434         u32 qkey;
 435         u32 src_qp;
 436         u16 dlid;
 437
 438         /* Check for GRH */
 439         if (!has_grh) {
 440                 ohdr = &hdr->u.oth;
 441                 hdrsize = 8 + 12 + 8;   /* LRH + BTH + DETH */
 442         } else {
 443                 ohdr = &hdr->u.l.oth;
 444                 hdrsize = 8 + 40 + 12 + 8; /* LRH + GRH + BTH + DETH */
 445         }
 446         qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
 447         src_qp = be32_to_cpu(ohdr->u.ud.deth[1]) & RVT_QPN_MASK;
 448
 449         /*
 450          * Get the number of bytes the message was padded by
 451          * and drop incomplete packets.
 452          */
 453         pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
 454         if (unlikely(tlen < (hdrsize + pad + 4)))
 455                 goto drop;
 456
 457         tlen -= hdrsize + pad + 4;
 458
 459         /*
 460          * Check that the permissive LID is only used on QP0
 461          * and the QKEY matches (see 9.6.1.4.1 and 9.6.1.5.1).
 462          */
 463         if (qp->ibqp.qp_num) {
 464                 if (unlikely(hdr->lrh[1] == IB_LID_PERMISSIVE ||
 465                              hdr->lrh[3] == IB_LID_PERMISSIVE))
 466                         goto drop;
 467                 if (qp->ibqp.qp_num > 1) {
 468                         u16 pkey1, pkey2;
 469
 470                         pkey1 = be32_to_cpu(ohdr->bth[0]);
 471                         pkey2 = qib_get_pkey(ibp, qp->s_pkey_index);
 472                         if (unlikely(!qib_pkey_ok(pkey1, pkey2))) {
 473                                 qib_bad_pkey(ibp,
 474                                              pkey1,
 475                                              (be16_to_cpu(hdr->lrh[0]) >> 4) &
 476                                                 0xF,
 477                                              src_qp, qp->ibqp.qp_num,
 478                                              hdr->lrh[3], hdr->lrh[1]);
 479                                 return;
 480                         }
 481                 }
 482                 if (unlikely(qkey != qp->qkey))
 483                         return;
 484
 485                 /* Drop invalid MAD packets (see 13.5.3.1). */
 486                 if (unlikely(qp->ibqp.qp_num == 1 &&
 487                              (tlen != 256 ||
 488                               (be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))
 489                         goto drop;
 490         } else {
 491                 struct ib_smp *smp;
 492
 493                 /* Drop invalid MAD packets (see 13.5.3.1). */
 494                 if (tlen != 256 || (be16_to_cpu(hdr->lrh[0]) >> 12) != 15)
 495                         goto drop;
 496                 smp = (struct ib_smp *) data;
 497                 if ((hdr->lrh[1] == IB_LID_PERMISSIVE ||
 498                      hdr->lrh[3] == IB_LID_PERMISSIVE) &&
 499                     smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
 500                         goto drop;
 501         }
 502
 503         /*
 504          * The opcode is in the low byte when its in network order
 505          * (top byte when in host order).
 506          */
 507         opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
 508         if (qp->ibqp.qp_num > 1 &&
 509             opcode == IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE) {
 510                 wc.ex.imm_data = ohdr->u.ud.imm_data;
 511                 wc.wc_flags = IB_WC_WITH_IMM;
 512         } else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
 513                 wc.ex.imm_data = 0;
 514                 wc.wc_flags = 0;
 515         } else
 516                 goto drop;
 517
 518         /*
 519          * A GRH is expected to precede the data even if not
 520          * present on the wire.
 521          */
 522         wc.byte_len = tlen + sizeof(struct ib_grh);
 523
 524         /*
 525          * Get the next work request entry to find where to put the data.
 526          */
 527         if (qp->r_flags & RVT_R_REUSE_SGE)
 528                 qp->r_flags &= ~RVT_R_REUSE_SGE;
 529         else {
 530                 int ret;
 531
 532                 ret = rvt_get_rwqe(qp, false);
 533                 if (ret < 0) {
 534                         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
 535                         return;
 536                 }
 537                 if (!ret) {
 538                         if (qp->ibqp.qp_num == 0)
 539                                 ibp->rvp.n_vl15_dropped++;
 540                         return;
 541                 }
 542         }
 543         /* Silently drop packets which are too big. */
 544         if (unlikely(wc.byte_len > qp->r_len)) {
 545                 qp->r_flags |= RVT_R_REUSE_SGE;
 546                 goto drop;
 547         }
 548         if (has_grh) {
 549                 rvt_copy_sge(qp, &qp->r_sge, &hdr->u.l.grh,
 550                              sizeof(struct ib_grh), true, false);
 551                 wc.wc_flags |= IB_WC_GRH;
 552         } else
 553                 rvt_skip_sge(&qp->r_sge, sizeof(struct ib_grh), true);
 554         rvt_copy_sge(qp, &qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh),
 555                      true, false);
 556         rvt_put_ss(&qp->r_sge);
 557         if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
 558                 return;
 559         wc.wr_id = qp->r_wr_id;
 560         wc.status = IB_WC_SUCCESS;
 561         wc.opcode = IB_WC_RECV;
 562         wc.vendor_err = 0;
 563         wc.qp = &qp->ibqp;
 564         wc.src_qp = src_qp;
 565         wc.pkey_index = qp->ibqp.qp_type == IB_QPT_GSI ?
 566                 qib_lookup_pkey(ibp, be32_to_cpu(ohdr->bth[0])) : 0;
 567         wc.slid = be16_to_cpu(hdr->lrh[3]);
 568         wc.sl = (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF;
 569         dlid = be16_to_cpu(hdr->lrh[1]);
 570         /*
 571          * Save the LMC lower bits if the destination LID is a unicast LID.
 572          */
 573         wc.dlid_path_bits = dlid >= be16_to_cpu(IB_MULTICAST_LID_BASE) ? 0 :
 574                 dlid & ((1 << ppd_from_ibp(ibp)->lmc) - 1);
 575         wc.port_num = qp->port_num;
 576         /* Signal completion event if the solicited bit is set. */
 577         rvt_recv_cq(qp, &wc, ib_bth_is_solicited(ohdr));
 578         return;
 579
 580 drop:
 581         ibp->rvp.n_pkt_drops++;
 582 }