drivers/infiniband/hw/hfi1/uc.c

   1 /*
   2  * Copyright(c) 2015 - 2018 Intel Corporation.
   3  *
   4  * This file is provided under a dual BSD/GPLv2 license.  When using or
   5  * redistributing this file, you may do so under either license.
   6  *
   7  * GPL LICENSE SUMMARY
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * BSD LICENSE
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  *
  24  *  - Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  *  - Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in
  28  *    the documentation and/or other materials provided with the
  29  *    distribution.
  30  *  - Neither the name of Intel Corporation nor the names of its
  31  *    contributors may be used to endorse or promote products derived
  32  *    from this software without specific prior written permission.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45  *
  46  */
  47
  48 #include "hfi.h"
  49 #include "verbs_txreq.h"
  50 #include "qp.h"
  51
  52 /* cut down ridiculously long IB macro names */
  53 #define OP(x) UC_OP(x)
  54
  55 /**
  56  * hfi1_make_uc_req - construct a request packet (SEND, RDMA write)
  57  * @qp: a pointer to the QP
  58  * @ps: the current packet state
  59  *
  60  * Assume s_lock is held.
  61  *
  62  * Return 1 if constructed; otherwise, return 0.
  63  */
  64 int hfi1_make_uc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
  65 {
  66         struct hfi1_qp_priv *priv = qp->priv;
  67         struct ib_other_headers *ohdr;
  68         struct rvt_swqe *wqe;
  69         u32 hwords;
  70         u32 bth0 = 0;
  71         u32 len;
  72         u32 pmtu = qp->pmtu;
  73         int middle = 0;
  74
  75         ps->s_txreq = get_txreq(ps->dev, qp);
  76         if (!ps->s_txreq)
  77                 goto bail_no_tx;
  78
  79         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
  80                 if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
  81                         goto bail;
  82                 /* We are in the error state, flush the work request. */
  83                 if (qp->s_last == READ_ONCE(qp->s_head))
  84                         goto bail;
  85                 /* If DMAs are in progress, we can't flush immediately. */
  86                 if (iowait_sdma_pending(&priv->s_iowait)) {
  87                         qp->s_flags |= RVT_S_WAIT_DMA;
  88                         goto bail;
  89                 }
  90                 clear_ahg(qp);
  91                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
  92                 rvt_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
  93                 goto done_free_tx;
  94         }
  95
  96         if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
  97                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
  98                 hwords = 5;
  99                 if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
 100                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
 101                 else
 102                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
 103         } else {
 104                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
 105                 hwords = 7;
 106                 if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
 107                     (hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))))
 108                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
 109                 else
 110                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
 111         }
 112
 113         /* Get the next send request. */
 114         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
 115         qp->s_wqe = NULL;
 116         switch (qp->s_state) {
 117         default:
 118                 if (!(ib_rvt_state_ops[qp->state] &
 119                     RVT_PROCESS_NEXT_SEND_OK))
 120                         goto bail;
 121                 /* Check if send work queue is empty. */
 122                 if (qp->s_cur == READ_ONCE(qp->s_head)) {
 123                         clear_ahg(qp);
 124                         goto bail;
 125                 }
 126                 /*
 127                  * Local operations are processed immediately
 128                  * after all prior requests have completed.
 129                  */
 130                 if (wqe->wr.opcode == IB_WR_REG_MR ||
 131                     wqe->wr.opcode == IB_WR_LOCAL_INV) {
 132                         int local_ops = 0;
 133                         int err = 0;
 134
 135                         if (qp->s_last != qp->s_cur)
 136                                 goto bail;
 137                         if (++qp->s_cur == qp->s_size)
 138                                 qp->s_cur = 0;
 139                         if (!(wqe->wr.send_flags & RVT_SEND_COMPLETION_ONLY)) {
 140                                 err = rvt_invalidate_rkey(
 141                                         qp, wqe->wr.ex.invalidate_rkey);
 142                                 local_ops = 1;
 143                         }
 144                         rvt_send_complete(qp, wqe, err ? IB_WC_LOC_PROT_ERR
 145                                                         : IB_WC_SUCCESS);
 146                         if (local_ops)
 147                                 atomic_dec(&qp->local_ops_pending);
 148                         goto done_free_tx;
 149                 }
 150                 /*
 151                  * Start a new request.
 152                  */
 153                 qp->s_psn = wqe->psn;
 154                 qp->s_sge.sge = wqe->sg_list[0];
 155                 qp->s_sge.sg_list = wqe->sg_list + 1;
 156                 qp->s_sge.num_sge = wqe->wr.num_sge;
 157                 qp->s_sge.total_len = wqe->length;
 158                 len = wqe->length;
 159                 qp->s_len = len;
 160                 switch (wqe->wr.opcode) {
 161                 case IB_WR_SEND:
 162                 case IB_WR_SEND_WITH_IMM:
 163                         if (len > pmtu) {
 164                                 qp->s_state = OP(SEND_FIRST);
 165                                 len = pmtu;
 166                                 break;
 167                         }
 168                         if (wqe->wr.opcode == IB_WR_SEND) {
 169                                 qp->s_state = OP(SEND_ONLY);
 170                         } else {
 171                                 qp->s_state =
 172                                         OP(SEND_ONLY_WITH_IMMEDIATE);
 173                                 /* Immediate data comes after the BTH */
 174                                 ohdr->u.imm_data = wqe->wr.ex.imm_data;
 175                                 hwords += 1;
 176                         }
 177                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 178                                 bth0 |= IB_BTH_SOLICITED;
 179                         qp->s_wqe = wqe;
 180                         if (++qp->s_cur >= qp->s_size)
 181                                 qp->s_cur = 0;
 182                         break;
 183
 184                 case IB_WR_RDMA_WRITE:
 185                 case IB_WR_RDMA_WRITE_WITH_IMM:
 186                         ohdr->u.rc.reth.vaddr =
 187                                 cpu_to_be64(wqe->rdma_wr.remote_addr);
 188                         ohdr->u.rc.reth.rkey =
 189                                 cpu_to_be32(wqe->rdma_wr.rkey);
 190                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 191                         hwords += sizeof(struct ib_reth) / 4;
 192                         if (len > pmtu) {
 193                                 qp->s_state = OP(RDMA_WRITE_FIRST);
 194                                 len = pmtu;
 195                                 break;
 196                         }
 197                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 198                                 qp->s_state = OP(RDMA_WRITE_ONLY);
 199                         } else {
 200                                 qp->s_state =
 201                                         OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
 202                                 /* Immediate data comes after the RETH */
 203                                 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
 204                                 hwords += 1;
 205                                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 206                                         bth0 |= IB_BTH_SOLICITED;
 207                         }
 208                         qp->s_wqe = wqe;
 209                         if (++qp->s_cur >= qp->s_size)
 210                                 qp->s_cur = 0;
 211                         break;
 212
 213                 default:
 214                         goto bail;
 215                 }
 216                 break;
 217
 218         case OP(SEND_FIRST):
 219                 qp->s_state = OP(SEND_MIDDLE);
 220                 fallthrough;
 221         case OP(SEND_MIDDLE):
 222                 len = qp->s_len;
 223                 if (len > pmtu) {
 224                         len = pmtu;
 225                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 226                         break;
 227                 }
 228                 if (wqe->wr.opcode == IB_WR_SEND) {
 229                         qp->s_state = OP(SEND_LAST);
 230                 } else {
 231                         qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
 232                         /* Immediate data comes after the BTH */
 233                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 234                         hwords += 1;
 235                 }
 236                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 237                         bth0 |= IB_BTH_SOLICITED;
 238                 qp->s_wqe = wqe;
 239                 if (++qp->s_cur >= qp->s_size)
 240                         qp->s_cur = 0;
 241                 break;
 242
 243         case OP(RDMA_WRITE_FIRST):
 244                 qp->s_state = OP(RDMA_WRITE_MIDDLE);
 245                 fallthrough;
 246         case OP(RDMA_WRITE_MIDDLE):
 247                 len = qp->s_len;
 248                 if (len > pmtu) {
 249                         len = pmtu;
 250                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 251                         break;
 252                 }
 253                 if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 254                         qp->s_state = OP(RDMA_WRITE_LAST);
 255                 } else {
 256                         qp->s_state =
 257                                 OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
 258                         /* Immediate data comes after the BTH */
 259                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 260                         hwords += 1;
 261                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 262                                 bth0 |= IB_BTH_SOLICITED;
 263                 }
 264                 qp->s_wqe = wqe;
 265                 if (++qp->s_cur >= qp->s_size)
 266                         qp->s_cur = 0;
 267                 break;
 268         }
 269         qp->s_len -= len;
 270         ps->s_txreq->hdr_dwords = hwords;
 271         ps->s_txreq->sde = priv->s_sde;
 272         ps->s_txreq->ss = &qp->s_sge;
 273         ps->s_txreq->s_cur_size = len;
 274         hfi1_make_ruc_header(qp, ohdr, bth0 | (qp->s_state << 24),
 275                              qp->remote_qpn, mask_psn(qp->s_psn++),
 276                              middle, ps);
 277         return 1;
 278
 279 done_free_tx:
 280         hfi1_put_txreq(ps->s_txreq);
 281         ps->s_txreq = NULL;
 282         return 1;
 283
 284 bail:
 285         hfi1_put_txreq(ps->s_txreq);
 286
 287 bail_no_tx:
 288         ps->s_txreq = NULL;
 289         qp->s_flags &= ~RVT_S_BUSY;
 290         return 0;
 291 }
 292
 293 /**
 294  * hfi1_uc_rcv - handle an incoming UC packet
 295  * @packet: the packet structure
 296  *
 297  * This is called from qp_rcv() to process an incoming UC packet
 298  * for the given QP.
 299  * Called at interrupt level.
 300  */
 301 void hfi1_uc_rcv(struct hfi1_packet *packet)
 302 {
 303         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
 304         void *data = packet->payload;
 305         u32 tlen = packet->tlen;
 306         struct rvt_qp *qp = packet->qp;
 307         struct ib_other_headers *ohdr = packet->ohdr;
 308         u32 opcode = packet->opcode;
 309         u32 hdrsize = packet->hlen;
 310         u32 psn;
 311         u32 pad = packet->pad;
 312         struct ib_wc wc;
 313         u32 pmtu = qp->pmtu;
 314         struct ib_reth *reth;
 315         int ret;
 316         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
 317
 318         if (hfi1_ruc_check_hdr(ibp, packet))
 319                 return;
 320
 321         process_ecn(qp, packet);
 322
 323         psn = ib_bth_get_psn(ohdr);
 324         /* Compare the PSN verses the expected PSN. */
 325         if (unlikely(cmp_psn(psn, qp->r_psn) != 0)) {
 326                 /*
 327                  * Handle a sequence error.
 328                  * Silently drop any current message.
 329                  */
 330                 qp->r_psn = psn;
 331 inv:
 332                 if (qp->r_state == OP(SEND_FIRST) ||
 333                     qp->r_state == OP(SEND_MIDDLE)) {
 334                         set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
 335                         qp->r_sge.num_sge = 0;
 336                 } else {
 337                         rvt_put_ss(&qp->r_sge);
 338                 }
 339                 qp->r_state = OP(SEND_LAST);
 340                 switch (opcode) {
 341                 case OP(SEND_FIRST):
 342                 case OP(SEND_ONLY):
 343                 case OP(SEND_ONLY_WITH_IMMEDIATE):
 344                         goto send_first;
 345
 346                 case OP(RDMA_WRITE_FIRST):
 347                 case OP(RDMA_WRITE_ONLY):
 348                 case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
 349                         goto rdma_first;
 350
 351                 default:
 352                         goto drop;
 353                 }
 354         }
 355
 356         /* Check for opcode sequence errors. */
 357         switch (qp->r_state) {
 358         case OP(SEND_FIRST):
 359         case OP(SEND_MIDDLE):
 360                 if (opcode == OP(SEND_MIDDLE) ||
 361                     opcode == OP(SEND_LAST) ||
 362                     opcode == OP(SEND_LAST_WITH_IMMEDIATE))
 363                         break;
 364                 goto inv;
 365
 366         case OP(RDMA_WRITE_FIRST):
 367         case OP(RDMA_WRITE_MIDDLE):
 368                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
 369                     opcode == OP(RDMA_WRITE_LAST) ||
 370                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
 371                         break;
 372                 goto inv;
 373
 374         default:
 375                 if (opcode == OP(SEND_FIRST) ||
 376                     opcode == OP(SEND_ONLY) ||
 377                     opcode == OP(SEND_ONLY_WITH_IMMEDIATE) ||
 378                     opcode == OP(RDMA_WRITE_FIRST) ||
 379                     opcode == OP(RDMA_WRITE_ONLY) ||
 380                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
 381                         break;
 382                 goto inv;
 383         }
 384
 385         if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
 386                 rvt_comm_est(qp);
 387
 388         /* OK, process the packet. */
 389         switch (opcode) {
 390         case OP(SEND_FIRST):
 391         case OP(SEND_ONLY):
 392         case OP(SEND_ONLY_WITH_IMMEDIATE):
 393 send_first:
 394                 if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
 395                         qp->r_sge = qp->s_rdma_read_sge;
 396                 } else {
 397                         ret = rvt_get_rwqe(qp, false);
 398                         if (ret < 0)
 399                                 goto op_err;
 400                         if (!ret)
 401                                 goto drop;
 402                         /*
 403                          * qp->s_rdma_read_sge will be the owner
 404                          * of the mr references.
 405                          */
 406                         qp->s_rdma_read_sge = qp->r_sge;
 407                 }
 408                 qp->r_rcv_len = 0;
 409                 if (opcode == OP(SEND_ONLY))
 410                         goto no_immediate_data;
 411                 else if (opcode == OP(SEND_ONLY_WITH_IMMEDIATE))
 412                         goto send_last_imm;
 413                 fallthrough;
 414         case OP(SEND_MIDDLE):
 415                 /* Check for invalid length PMTU or posted rwqe len. */
 416                 /*
 417                  * There will be no padding for 9B packet but 16B packets
 418                  * will come in with some padding since we always add
 419                  * CRC and LT bytes which will need to be flit aligned
 420                  */
 421                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
 422                         goto rewind;
 423                 qp->r_rcv_len += pmtu;
 424                 if (unlikely(qp->r_rcv_len > qp->r_len))
 425                         goto rewind;
 426                 rvt_copy_sge(qp, &qp->r_sge, data, pmtu, false, false);
 427                 break;
 428
 429         case OP(SEND_LAST_WITH_IMMEDIATE):
 430 send_last_imm:
 431                 wc.ex.imm_data = ohdr->u.imm_data;
 432                 wc.wc_flags = IB_WC_WITH_IMM;
 433                 goto send_last;
 434         case OP(SEND_LAST):
 435 no_immediate_data:
 436                 wc.ex.imm_data = 0;
 437                 wc.wc_flags = 0;
 438 send_last:
 439                 /* Check for invalid length. */
 440                 /* LAST len should be >= 1 */
 441                 if (unlikely(tlen < (hdrsize + extra_bytes)))
 442                         goto rewind;
 443                 /* Don't count the CRC. */
 444                 tlen -= (hdrsize + extra_bytes);
 445                 wc.byte_len = tlen + qp->r_rcv_len;
 446                 if (unlikely(wc.byte_len > qp->r_len))
 447                         goto rewind;
 448                 wc.opcode = IB_WC_RECV;
 449                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, false, false);
 450                 rvt_put_ss(&qp->s_rdma_read_sge);
 451 last_imm:
 452                 wc.wr_id = qp->r_wr_id;
 453                 wc.status = IB_WC_SUCCESS;
 454                 wc.qp = &qp->ibqp;
 455                 wc.src_qp = qp->remote_qpn;
 456                 wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
 457                 /*
 458                  * It seems that IB mandates the presence of an SL in a
 459                  * work completion only for the UD transport (see section
 460                  * 11.4.2 of IBTA Vol. 1).
 461                  *
 462                  * However, the way the SL is chosen below is consistent
 463                  * with the way that IB/qib works and is trying avoid
 464                  * introducing incompatibilities.
 465                  *
 466                  * See also OPA Vol. 1, section 9.7.6, and table 9-17.
 467                  */
 468                 wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
 469                 /* zero fields that are N/A */
 470                 wc.vendor_err = 0;
 471                 wc.pkey_index = 0;
 472                 wc.dlid_path_bits = 0;
 473                 wc.port_num = 0;
 474                 /* Signal completion event if the solicited bit is set. */
 475                 rvt_recv_cq(qp, &wc, ib_bth_is_solicited(ohdr));
 476                 break;
 477
 478         case OP(RDMA_WRITE_FIRST):
 479         case OP(RDMA_WRITE_ONLY):
 480         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): /* consume RWQE */
 481 rdma_first:
 482                 if (unlikely(!(qp->qp_access_flags &
 483                                IB_ACCESS_REMOTE_WRITE))) {
 484                         goto drop;
 485                 }
 486                 reth = &ohdr->u.rc.reth;
 487                 qp->r_len = be32_to_cpu(reth->length);
 488                 qp->r_rcv_len = 0;
 489                 qp->r_sge.sg_list = NULL;
 490                 if (qp->r_len != 0) {
 491                         u32 rkey = be32_to_cpu(reth->rkey);
 492                         u64 vaddr = be64_to_cpu(reth->vaddr);
 493                         int ok;
 494
 495                         /* Check rkey */
 496                         ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len,
 497                                          vaddr, rkey, IB_ACCESS_REMOTE_WRITE);
 498                         if (unlikely(!ok))
 499                                 goto drop;
 500                         qp->r_sge.num_sge = 1;
 501                 } else {
 502                         qp->r_sge.num_sge = 0;
 503                         qp->r_sge.sge.mr = NULL;
 504                         qp->r_sge.sge.vaddr = NULL;
 505                         qp->r_sge.sge.length = 0;
 506                         qp->r_sge.sge.sge_length = 0;
 507                 }
 508                 if (opcode == OP(RDMA_WRITE_ONLY)) {
 509                         goto rdma_last;
 510                 } else if (opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE)) {
 511                         wc.ex.imm_data = ohdr->u.rc.imm_data;
 512                         goto rdma_last_imm;
 513                 }
 514                 fallthrough;
 515         case OP(RDMA_WRITE_MIDDLE):
 516                 /* Check for invalid length PMTU or posted rwqe len. */
 517                 if (unlikely(tlen != (hdrsize + pmtu + 4)))
 518                         goto drop;
 519                 qp->r_rcv_len += pmtu;
 520                 if (unlikely(qp->r_rcv_len > qp->r_len))
 521                         goto drop;
 522                 rvt_copy_sge(qp, &qp->r_sge, data, pmtu, true, false);
 523                 break;
 524
 525         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
 526                 wc.ex.imm_data = ohdr->u.imm_data;
 527 rdma_last_imm:
 528                 wc.wc_flags = IB_WC_WITH_IMM;
 529
 530                 /* Check for invalid length. */
 531                 /* LAST len should be >= 1 */
 532                 if (unlikely(tlen < (hdrsize + pad + 4)))
 533                         goto drop;
 534                 /* Don't count the CRC. */
 535                 tlen -= (hdrsize + extra_bytes);
 536                 if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
 537                         goto drop;
 538                 if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
 539                         rvt_put_ss(&qp->s_rdma_read_sge);
 540                 } else {
 541                         ret = rvt_get_rwqe(qp, true);
 542                         if (ret < 0)
 543                                 goto op_err;
 544                         if (!ret)
 545                                 goto drop;
 546                 }
 547                 wc.byte_len = qp->r_len;
 548                 wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
 549                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, false);
 550                 rvt_put_ss(&qp->r_sge);
 551                 goto last_imm;
 552
 553         case OP(RDMA_WRITE_LAST):
 554 rdma_last:
 555                 /* Check for invalid length. */
 556                 /* LAST len should be >= 1 */
 557                 if (unlikely(tlen < (hdrsize + pad + 4)))
 558                         goto drop;
 559                 /* Don't count the CRC. */
 560                 tlen -= (hdrsize + extra_bytes);
 561                 if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
 562                         goto drop;
 563                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, false);
 564                 rvt_put_ss(&qp->r_sge);
 565                 break;
 566
 567         default:
 568                 /* Drop packet for unknown opcodes. */
 569                 goto drop;
 570         }
 571         qp->r_psn++;
 572         qp->r_state = opcode;
 573         return;
 574
 575 rewind:
 576         set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
 577         qp->r_sge.num_sge = 0;
 578 drop:
 579         ibp->rvp.n_pkt_drops++;
 580         return;
 581
 582 op_err:
 583         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
 584 }