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  *
  59  * Assume s_lock is held.
  60  *
  61  * Return 1 if constructed; otherwise, return 0.
  62  */
  63 int hfi1_make_uc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
  64 {
  65         struct hfi1_qp_priv *priv = qp->priv;
  66         struct ib_other_headers *ohdr;
  67         struct rvt_swqe *wqe;
  68         u32 hwords;
  69         u32 bth0 = 0;
  70         u32 len;
  71         u32 pmtu = qp->pmtu;
  72         int middle = 0;
  73
  74         ps->s_txreq = get_txreq(ps->dev, qp);
  75         if (!ps->s_txreq)
  76                 goto bail_no_tx;
  77
  78         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
  79                 if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
  80                         goto bail;
  81                 /* We are in the error state, flush the work request. */
  82                 if (qp->s_last == READ_ONCE(qp->s_head))
  83                         goto bail;
  84                 /* If DMAs are in progress, we can't flush immediately. */
  85                 if (iowait_sdma_pending(&priv->s_iowait)) {
  86                         qp->s_flags |= RVT_S_WAIT_DMA;
  87                         goto bail;
  88                 }
  89                 clear_ahg(qp);
  90                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
  91                 rvt_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
  92                 goto done_free_tx;
  93         }
  94
  95         if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
  96                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
  97                 hwords = 5;
  98                 if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
  99                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
 100                 else
 101                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
 102         } else {
 103                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
 104                 hwords = 7;
 105                 if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
 106                     (hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))))
 107                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
 108                 else
 109                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
 110         }
 111
 112         /* Get the next send request. */
 113         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
 114         qp->s_wqe = NULL;
 115         switch (qp->s_state) {
 116         default:
 117                 if (!(ib_rvt_state_ops[qp->state] &
 118                     RVT_PROCESS_NEXT_SEND_OK))
 119                         goto bail;
 120                 /* Check if send work queue is empty. */
 121                 if (qp->s_cur == READ_ONCE(qp->s_head)) {
 122                         clear_ahg(qp);
 123                         goto bail;
 124                 }
 125                 /*
 126                  * Local operations are processed immediately
 127                  * after all prior requests have completed.
 128                  */
 129                 if (wqe->wr.opcode == IB_WR_REG_MR ||
 130                     wqe->wr.opcode == IB_WR_LOCAL_INV) {
 131                         int local_ops = 0;
 132                         int err = 0;
 133
 134                         if (qp->s_last != qp->s_cur)
 135                                 goto bail;
 136                         if (++qp->s_cur == qp->s_size)
 137                                 qp->s_cur = 0;
 138                         if (!(wqe->wr.send_flags & RVT_SEND_COMPLETION_ONLY)) {
 139                                 err = rvt_invalidate_rkey(
 140                                         qp, wqe->wr.ex.invalidate_rkey);
 141                                 local_ops = 1;
 142                         }
 143                         rvt_send_complete(qp, wqe, err ? IB_WC_LOC_PROT_ERR
 144                                                         : IB_WC_SUCCESS);
 145                         if (local_ops)
 146                                 atomic_dec(&qp->local_ops_pending);
 147                         goto done_free_tx;
 148                 }
 149                 /*
 150                  * Start a new request.
 151                  */
 152                 qp->s_psn = wqe->psn;
 153                 qp->s_sge.sge = wqe->sg_list[0];
 154                 qp->s_sge.sg_list = wqe->sg_list + 1;
 155                 qp->s_sge.num_sge = wqe->wr.num_sge;
 156                 qp->s_sge.total_len = wqe->length;
 157                 len = wqe->length;
 158                 qp->s_len = len;
 159                 switch (wqe->wr.opcode) {
 160                 case IB_WR_SEND:
 161                 case IB_WR_SEND_WITH_IMM:
 162                         if (len > pmtu) {
 163                                 qp->s_state = OP(SEND_FIRST);
 164                                 len = pmtu;
 165                                 break;
 166                         }
 167                         if (wqe->wr.opcode == IB_WR_SEND) {
 168                                 qp->s_state = OP(SEND_ONLY);
 169                         } else {
 170                                 qp->s_state =
 171                                         OP(SEND_ONLY_WITH_IMMEDIATE);
 172                                 /* Immediate data comes after the BTH */
 173                                 ohdr->u.imm_data = wqe->wr.ex.imm_data;
 174                                 hwords += 1;
 175                         }
 176                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 177                                 bth0 |= IB_BTH_SOLICITED;
 178                         qp->s_wqe = wqe;
 179                         if (++qp->s_cur >= qp->s_size)
 180                                 qp->s_cur = 0;
 181                         break;
 182
 183                 case IB_WR_RDMA_WRITE:
 184                 case IB_WR_RDMA_WRITE_WITH_IMM:
 185                         ohdr->u.rc.reth.vaddr =
 186                                 cpu_to_be64(wqe->rdma_wr.remote_addr);
 187                         ohdr->u.rc.reth.rkey =
 188                                 cpu_to_be32(wqe->rdma_wr.rkey);
 189                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 190                         hwords += sizeof(struct ib_reth) / 4;
 191                         if (len > pmtu) {
 192                                 qp->s_state = OP(RDMA_WRITE_FIRST);
 193                                 len = pmtu;
 194                                 break;
 195                         }
 196                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 197                                 qp->s_state = OP(RDMA_WRITE_ONLY);
 198                         } else {
 199                                 qp->s_state =
 200                                         OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
 201                                 /* Immediate data comes after the RETH */
 202                                 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
 203                                 hwords += 1;
 204                                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 205                                         bth0 |= IB_BTH_SOLICITED;
 206                         }
 207                         qp->s_wqe = wqe;
 208                         if (++qp->s_cur >= qp->s_size)
 209                                 qp->s_cur = 0;
 210                         break;
 211
 212                 default:
 213                         goto bail;
 214                 }
 215                 break;
 216
 217         case OP(SEND_FIRST):
 218                 qp->s_state = OP(SEND_MIDDLE);
 219                 fallthrough;
 220         case OP(SEND_MIDDLE):
 221                 len = qp->s_len;
 222                 if (len > pmtu) {
 223                         len = pmtu;
 224                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 225                         break;
 226                 }
 227                 if (wqe->wr.opcode == IB_WR_SEND) {
 228                         qp->s_state = OP(SEND_LAST);
 229                 } else {
 230                         qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
 231                         /* Immediate data comes after the BTH */
 232                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 233                         hwords += 1;
 234                 }
 235                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 236                         bth0 |= IB_BTH_SOLICITED;
 237                 qp->s_wqe = wqe;
 238                 if (++qp->s_cur >= qp->s_size)
 239                         qp->s_cur = 0;
 240                 break;
 241
 242         case OP(RDMA_WRITE_FIRST):
 243                 qp->s_state = OP(RDMA_WRITE_MIDDLE);
 244                 fallthrough;
 245         case OP(RDMA_WRITE_MIDDLE):
 246                 len = qp->s_len;
 247                 if (len > pmtu) {
 248                         len = pmtu;
 249                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 250                         break;
 251                 }
 252                 if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 253                         qp->s_state = OP(RDMA_WRITE_LAST);
 254                 } else {
 255                         qp->s_state =
 256                                 OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
 257                         /* Immediate data comes after the BTH */
 258                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 259                         hwords += 1;
 260                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 261                                 bth0 |= IB_BTH_SOLICITED;
 262                 }
 263                 qp->s_wqe = wqe;
 264                 if (++qp->s_cur >= qp->s_size)
 265                         qp->s_cur = 0;
 266                 break;
 267         }
 268         qp->s_len -= len;
 269         ps->s_txreq->hdr_dwords = hwords;
 270         ps->s_txreq->sde = priv->s_sde;
 271         ps->s_txreq->ss = &qp->s_sge;
 272         ps->s_txreq->s_cur_size = len;
 273         hfi1_make_ruc_header(qp, ohdr, bth0 | (qp->s_state << 24),
 274                              qp->remote_qpn, mask_psn(qp->s_psn++),
 275                              middle, ps);
 276         return 1;
 277
 278 done_free_tx:
 279         hfi1_put_txreq(ps->s_txreq);
 280         ps->s_txreq = NULL;
 281         return 1;
 282
 283 bail:
 284         hfi1_put_txreq(ps->s_txreq);
 285
 286 bail_no_tx:
 287         ps->s_txreq = NULL;
 288         qp->s_flags &= ~RVT_S_BUSY;
 289         return 0;
 290 }
 291
 292 /**
 293  * hfi1_uc_rcv - handle an incoming UC packet
 294  * @ibp: the port the packet came in on
 295  * @hdr: the header of the packet
 296  * @rcv_flags: flags relevant to rcv processing
 297  * @data: the packet data
 298  * @tlen: the length of the packet
 299  * @qp: the QP for this packet.
 300  *
 301  * This is called from qp_rcv() to process an incoming UC packet
 302  * for the given QP.
 303  * Called at interrupt level.
 304  */
 305 void hfi1_uc_rcv(struct hfi1_packet *packet)
 306 {
 307         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
 308         void *data = packet->payload;
 309         u32 tlen = packet->tlen;
 310         struct rvt_qp *qp = packet->qp;
 311         struct ib_other_headers *ohdr = packet->ohdr;
 312         u32 opcode = packet->opcode;
 313         u32 hdrsize = packet->hlen;
 314         u32 psn;
 315         u32 pad = packet->pad;
 316         struct ib_wc wc;
 317         u32 pmtu = qp->pmtu;
 318         struct ib_reth *reth;
 319         int ret;
 320         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
 321
 322         if (hfi1_ruc_check_hdr(ibp, packet))
 323                 return;
 324
 325         process_ecn(qp, packet);
 326
 327         psn = ib_bth_get_psn(ohdr);
 328         /* Compare the PSN verses the expected PSN. */
 329         if (unlikely(cmp_psn(psn, qp->r_psn) != 0)) {
 330                 /*
 331                  * Handle a sequence error.
 332                  * Silently drop any current message.
 333                  */
 334                 qp->r_psn = psn;
 335 inv:
 336                 if (qp->r_state == OP(SEND_FIRST) ||
 337                     qp->r_state == OP(SEND_MIDDLE)) {
 338                         set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
 339                         qp->r_sge.num_sge = 0;
 340                 } else {
 341                         rvt_put_ss(&qp->r_sge);
 342                 }
 343                 qp->r_state = OP(SEND_LAST);
 344                 switch (opcode) {
 345                 case OP(SEND_FIRST):
 346                 case OP(SEND_ONLY):
 347                 case OP(SEND_ONLY_WITH_IMMEDIATE):
 348                         goto send_first;
 349
 350                 case OP(RDMA_WRITE_FIRST):
 351                 case OP(RDMA_WRITE_ONLY):
 352                 case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
 353                         goto rdma_first;
 354
 355                 default:
 356                         goto drop;
 357                 }
 358         }
 359
 360         /* Check for opcode sequence errors. */
 361         switch (qp->r_state) {
 362         case OP(SEND_FIRST):
 363         case OP(SEND_MIDDLE):
 364                 if (opcode == OP(SEND_MIDDLE) ||
 365                     opcode == OP(SEND_LAST) ||
 366                     opcode == OP(SEND_LAST_WITH_IMMEDIATE))
 367                         break;
 368                 goto inv;
 369
 370         case OP(RDMA_WRITE_FIRST):
 371         case OP(RDMA_WRITE_MIDDLE):
 372                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
 373                     opcode == OP(RDMA_WRITE_LAST) ||
 374                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
 375                         break;
 376                 goto inv;
 377
 378         default:
 379                 if (opcode == OP(SEND_FIRST) ||
 380                     opcode == OP(SEND_ONLY) ||
 381                     opcode == OP(SEND_ONLY_WITH_IMMEDIATE) ||
 382                     opcode == OP(RDMA_WRITE_FIRST) ||
 383                     opcode == OP(RDMA_WRITE_ONLY) ||
 384                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
 385                         break;
 386                 goto inv;
 387         }
 388
 389         if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
 390                 rvt_comm_est(qp);
 391
 392         /* OK, process the packet. */
 393         switch (opcode) {
 394         case OP(SEND_FIRST):
 395         case OP(SEND_ONLY):
 396         case OP(SEND_ONLY_WITH_IMMEDIATE):
 397 send_first:
 398                 if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
 399                         qp->r_sge = qp->s_rdma_read_sge;
 400                 } else {
 401                         ret = rvt_get_rwqe(qp, false);
 402                         if (ret < 0)
 403                                 goto op_err;
 404                         if (!ret)
 405                                 goto drop;
 406                         /*
 407                          * qp->s_rdma_read_sge will be the owner
 408                          * of the mr references.
 409                          */
 410                         qp->s_rdma_read_sge = qp->r_sge;
 411                 }
 412                 qp->r_rcv_len = 0;
 413                 if (opcode == OP(SEND_ONLY))
 414                         goto no_immediate_data;
 415                 else if (opcode == OP(SEND_ONLY_WITH_IMMEDIATE))
 416                         goto send_last_imm;
 417                 fallthrough;
 418         case OP(SEND_MIDDLE):
 419                 /* Check for invalid length PMTU or posted rwqe len. */
 420                 /*
 421                  * There will be no padding for 9B packet but 16B packets
 422                  * will come in with some padding since we always add
 423                  * CRC and LT bytes which will need to be flit aligned
 424                  */
 425                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
 426                         goto rewind;
 427                 qp->r_rcv_len += pmtu;
 428                 if (unlikely(qp->r_rcv_len > qp->r_len))
 429                         goto rewind;
 430                 rvt_copy_sge(qp, &qp->r_sge, data, pmtu, false, false);
 431                 break;
 432
 433         case OP(SEND_LAST_WITH_IMMEDIATE):
 434 send_last_imm:
 435                 wc.ex.imm_data = ohdr->u.imm_data;
 436                 wc.wc_flags = IB_WC_WITH_IMM;
 437                 goto send_last;
 438         case OP(SEND_LAST):
 439 no_immediate_data:
 440                 wc.ex.imm_data = 0;
 441                 wc.wc_flags = 0;
 442 send_last:
 443                 /* Check for invalid length. */
 444                 /* LAST len should be >= 1 */
 445                 if (unlikely(tlen < (hdrsize + extra_bytes)))
 446                         goto rewind;
 447                 /* Don't count the CRC. */
 448                 tlen -= (hdrsize + extra_bytes);
 449                 wc.byte_len = tlen + qp->r_rcv_len;
 450                 if (unlikely(wc.byte_len > qp->r_len))
 451                         goto rewind;
 452                 wc.opcode = IB_WC_RECV;
 453                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, false, false);
 454                 rvt_put_ss(&qp->s_rdma_read_sge);
 455 last_imm:
 456                 wc.wr_id = qp->r_wr_id;
 457                 wc.status = IB_WC_SUCCESS;
 458                 wc.qp = &qp->ibqp;
 459                 wc.src_qp = qp->remote_qpn;
 460                 wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
 461                 /*
 462                  * It seems that IB mandates the presence of an SL in a
 463                  * work completion only for the UD transport (see section
 464                  * 11.4.2 of IBTA Vol. 1).
 465                  *
 466                  * However, the way the SL is chosen below is consistent
 467                  * with the way that IB/qib works and is trying avoid
 468                  * introducing incompatibilities.
 469                  *
 470                  * See also OPA Vol. 1, section 9.7.6, and table 9-17.
 471                  */
 472                 wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
 473                 /* zero fields that are N/A */
 474                 wc.vendor_err = 0;
 475                 wc.pkey_index = 0;
 476                 wc.dlid_path_bits = 0;
 477                 wc.port_num = 0;
 478                 /* Signal completion event if the solicited bit is set. */
 479                 rvt_recv_cq(qp, &wc, ib_bth_is_solicited(ohdr));
 480                 break;
 481
 482         case OP(RDMA_WRITE_FIRST):
 483         case OP(RDMA_WRITE_ONLY):
 484         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): /* consume RWQE */
 485 rdma_first:
 486                 if (unlikely(!(qp->qp_access_flags &
 487                                IB_ACCESS_REMOTE_WRITE))) {
 488                         goto drop;
 489                 }
 490                 reth = &ohdr->u.rc.reth;
 491                 qp->r_len = be32_to_cpu(reth->length);
 492                 qp->r_rcv_len = 0;
 493                 qp->r_sge.sg_list = NULL;
 494                 if (qp->r_len != 0) {
 495                         u32 rkey = be32_to_cpu(reth->rkey);
 496                         u64 vaddr = be64_to_cpu(reth->vaddr);
 497                         int ok;
 498
 499                         /* Check rkey */
 500                         ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len,
 501                                          vaddr, rkey, IB_ACCESS_REMOTE_WRITE);
 502                         if (unlikely(!ok))
 503                                 goto drop;
 504                         qp->r_sge.num_sge = 1;
 505                 } else {
 506                         qp->r_sge.num_sge = 0;
 507                         qp->r_sge.sge.mr = NULL;
 508                         qp->r_sge.sge.vaddr = NULL;
 509                         qp->r_sge.sge.length = 0;
 510                         qp->r_sge.sge.sge_length = 0;
 511                 }
 512                 if (opcode == OP(RDMA_WRITE_ONLY)) {
 513                         goto rdma_last;
 514                 } else if (opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE)) {
 515                         wc.ex.imm_data = ohdr->u.rc.imm_data;
 516                         goto rdma_last_imm;
 517                 }
 518                 fallthrough;
 519         case OP(RDMA_WRITE_MIDDLE):
 520                 /* Check for invalid length PMTU or posted rwqe len. */
 521                 if (unlikely(tlen != (hdrsize + pmtu + 4)))
 522                         goto drop;
 523                 qp->r_rcv_len += pmtu;
 524                 if (unlikely(qp->r_rcv_len > qp->r_len))
 525                         goto drop;
 526                 rvt_copy_sge(qp, &qp->r_sge, data, pmtu, true, false);
 527                 break;
 528
 529         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
 530                 wc.ex.imm_data = ohdr->u.imm_data;
 531 rdma_last_imm:
 532                 wc.wc_flags = IB_WC_WITH_IMM;
 533
 534                 /* Check for invalid length. */
 535                 /* LAST len should be >= 1 */
 536                 if (unlikely(tlen < (hdrsize + pad + 4)))
 537                         goto drop;
 538                 /* Don't count the CRC. */
 539                 tlen -= (hdrsize + extra_bytes);
 540                 if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
 541                         goto drop;
 542                 if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
 543                         rvt_put_ss(&qp->s_rdma_read_sge);
 544                 } else {
 545                         ret = rvt_get_rwqe(qp, true);
 546                         if (ret < 0)
 547                                 goto op_err;
 548                         if (!ret)
 549                                 goto drop;
 550                 }
 551                 wc.byte_len = qp->r_len;
 552                 wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
 553                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, false);
 554                 rvt_put_ss(&qp->r_sge);
 555                 goto last_imm;
 556
 557         case OP(RDMA_WRITE_LAST):
 558 rdma_last:
 559                 /* Check for invalid length. */
 560                 /* LAST len should be >= 1 */
 561                 if (unlikely(tlen < (hdrsize + pad + 4)))
 562                         goto drop;
 563                 /* Don't count the CRC. */
 564                 tlen -= (hdrsize + extra_bytes);
 565                 if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
 566                         goto drop;
 567                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, false);
 568                 rvt_put_ss(&qp->r_sge);
 569                 break;
 570
 571         default:
 572                 /* Drop packet for unknown opcodes. */
 573                 goto drop;
 574         }
 575         qp->r_psn++;
 576         qp->r_state = opcode;
 577         return;
 578
 579 rewind:
 580         set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
 581         qp->r_sge.num_sge = 0;
 582 drop:
 583         ibp->rvp.n_pkt_drops++;
 584         return;
 585
 586 op_err:
 587         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
 588 }