drivers/infiniband/hw/hfi1/rc.c

   1 /*
   2  * Copyright(c) 2015, 2016 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 <linux/io.h>
  49 #include <rdma/rdma_vt.h>
  50 #include <rdma/rdmavt_qp.h>
  51
  52 #include "hfi.h"
  53 #include "qp.h"
  54 #include "verbs_txreq.h"
  55 #include "trace.h"
  56
  57 /* cut down ridiculously long IB macro names */
  58 #define OP(x) RC_OP(x)
  59
  60 static u32 restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe,
  61                        u32 psn, u32 pmtu)
  62 {
  63         u32 len;
  64
  65         len = delta_psn(psn, wqe->psn) * pmtu;
  66         ss->sge = wqe->sg_list[0];
  67         ss->sg_list = wqe->sg_list + 1;
  68         ss->num_sge = wqe->wr.num_sge;
  69         ss->total_len = wqe->length;
  70         rvt_skip_sge(ss, len, false);
  71         return wqe->length - len;
  72 }
  73
  74 /**
  75  * make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
  76  * @dev: the device for this QP
  77  * @qp: a pointer to the QP
  78  * @ohdr: a pointer to the IB header being constructed
  79  * @ps: the xmit packet state
  80  *
  81  * Return 1 if constructed; otherwise, return 0.
  82  * Note that we are in the responder's side of the QP context.
  83  * Note the QP s_lock must be held.
  84  */
  85 static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp,
  86                        struct ib_other_headers *ohdr,
  87                        struct hfi1_pkt_state *ps)
  88 {
  89         struct rvt_ack_entry *e;
  90         u32 hwords;
  91         u32 len;
  92         u32 bth0;
  93         u32 bth2;
  94         int middle = 0;
  95         u32 pmtu = qp->pmtu;
  96         struct hfi1_qp_priv *priv = qp->priv;
  97
  98         lockdep_assert_held(&qp->s_lock);
  99         /* Don't send an ACK if we aren't supposed to. */
 100         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
 101                 goto bail;
 102
 103         /* header size in 32-bit words LRH+BTH = (8+12)/4. */
 104         hwords = 5;
 105
 106         switch (qp->s_ack_state) {
 107         case OP(RDMA_READ_RESPONSE_LAST):
 108         case OP(RDMA_READ_RESPONSE_ONLY):
 109                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 110                 if (e->rdma_sge.mr) {
 111                         rvt_put_mr(e->rdma_sge.mr);
 112                         e->rdma_sge.mr = NULL;
 113                 }
 114                 /* FALLTHROUGH */
 115         case OP(ATOMIC_ACKNOWLEDGE):
 116                 /*
 117                  * We can increment the tail pointer now that the last
 118                  * response has been sent instead of only being
 119                  * constructed.
 120                  */
 121                 if (++qp->s_tail_ack_queue > HFI1_MAX_RDMA_ATOMIC)
 122                         qp->s_tail_ack_queue = 0;
 123                 /* FALLTHROUGH */
 124         case OP(SEND_ONLY):
 125         case OP(ACKNOWLEDGE):
 126                 /* Check for no next entry in the queue. */
 127                 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
 128                         if (qp->s_flags & RVT_S_ACK_PENDING)
 129                                 goto normal;
 130                         goto bail;
 131                 }
 132
 133                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 134                 if (e->opcode == OP(RDMA_READ_REQUEST)) {
 135                         /*
 136                          * If a RDMA read response is being resent and
 137                          * we haven't seen the duplicate request yet,
 138                          * then stop sending the remaining responses the
 139                          * responder has seen until the requester re-sends it.
 140                          */
 141                         len = e->rdma_sge.sge_length;
 142                         if (len && !e->rdma_sge.mr) {
 143                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
 144                                 goto bail;
 145                         }
 146                         /* Copy SGE state in case we need to resend */
 147                         ps->s_txreq->mr = e->rdma_sge.mr;
 148                         if (ps->s_txreq->mr)
 149                                 rvt_get_mr(ps->s_txreq->mr);
 150                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
 151                         qp->s_ack_rdma_sge.num_sge = 1;
 152                         ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 153                         if (len > pmtu) {
 154                                 len = pmtu;
 155                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
 156                         } else {
 157                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
 158                                 e->sent = 1;
 159                         }
 160                         ohdr->u.aeth = rvt_compute_aeth(qp);
 161                         hwords++;
 162                         qp->s_ack_rdma_psn = e->psn;
 163                         bth2 = mask_psn(qp->s_ack_rdma_psn++);
 164                 } else {
 165                         /* COMPARE_SWAP or FETCH_ADD */
 166                         ps->s_txreq->ss = NULL;
 167                         len = 0;
 168                         qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
 169                         ohdr->u.at.aeth = rvt_compute_aeth(qp);
 170                         ib_u64_put(e->atomic_data, &ohdr->u.at.atomic_ack_eth);
 171                         hwords += sizeof(ohdr->u.at) / sizeof(u32);
 172                         bth2 = mask_psn(e->psn);
 173                         e->sent = 1;
 174                 }
 175                 bth0 = qp->s_ack_state << 24;
 176                 break;
 177
 178         case OP(RDMA_READ_RESPONSE_FIRST):
 179                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
 180                 /* FALLTHROUGH */
 181         case OP(RDMA_READ_RESPONSE_MIDDLE):
 182                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 183                 ps->s_txreq->mr = qp->s_ack_rdma_sge.sge.mr;
 184                 if (ps->s_txreq->mr)
 185                         rvt_get_mr(ps->s_txreq->mr);
 186                 len = qp->s_ack_rdma_sge.sge.sge_length;
 187                 if (len > pmtu) {
 188                         len = pmtu;
 189                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 190                 } else {
 191                         ohdr->u.aeth = rvt_compute_aeth(qp);
 192                         hwords++;
 193                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
 194                         e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 195                         e->sent = 1;
 196                 }
 197                 bth0 = qp->s_ack_state << 24;
 198                 bth2 = mask_psn(qp->s_ack_rdma_psn++);
 199                 break;
 200
 201         default:
 202 normal:
 203                 /*
 204                  * Send a regular ACK.
 205                  * Set the s_ack_state so we wait until after sending
 206                  * the ACK before setting s_ack_state to ACKNOWLEDGE
 207                  * (see above).
 208                  */
 209                 qp->s_ack_state = OP(SEND_ONLY);
 210                 qp->s_flags &= ~RVT_S_ACK_PENDING;
 211                 ps->s_txreq->ss = NULL;
 212                 if (qp->s_nak_state)
 213                         ohdr->u.aeth =
 214                                 cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
 215                                             (qp->s_nak_state <<
 216                                              IB_AETH_CREDIT_SHIFT));
 217                 else
 218                         ohdr->u.aeth = rvt_compute_aeth(qp);
 219                 hwords++;
 220                 len = 0;
 221                 bth0 = OP(ACKNOWLEDGE) << 24;
 222                 bth2 = mask_psn(qp->s_ack_psn);
 223         }
 224         qp->s_rdma_ack_cnt++;
 225         qp->s_hdrwords = hwords;
 226         ps->s_txreq->sde = priv->s_sde;
 227         ps->s_txreq->s_cur_size = len;
 228         hfi1_make_ruc_header(qp, ohdr, bth0, bth2, middle, ps);
 229         /* pbc */
 230         ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2;
 231         return 1;
 232
 233 bail:
 234         qp->s_ack_state = OP(ACKNOWLEDGE);
 235         /*
 236          * Ensure s_rdma_ack_cnt changes are committed prior to resetting
 237          * RVT_S_RESP_PENDING
 238          */
 239         smp_wmb();
 240         qp->s_flags &= ~(RVT_S_RESP_PENDING
 241                                 | RVT_S_ACK_PENDING
 242                                 | RVT_S_AHG_VALID);
 243         return 0;
 244 }
 245
 246 /**
 247  * hfi1_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
 248  * @qp: a pointer to the QP
 249  *
 250  * Assumes s_lock is held.
 251  *
 252  * Return 1 if constructed; otherwise, return 0.
 253  */
 254 int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
 255 {
 256         struct hfi1_qp_priv *priv = qp->priv;
 257         struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
 258         struct ib_other_headers *ohdr;
 259         struct rvt_sge_state *ss;
 260         struct rvt_swqe *wqe;
 261         /* header size in 32-bit words LRH+BTH = (8+12)/4. */
 262         u32 hwords = 5;
 263         u32 len;
 264         u32 bth0 = 0;
 265         u32 bth2;
 266         u32 pmtu = qp->pmtu;
 267         char newreq;
 268         int middle = 0;
 269         int delta;
 270
 271         lockdep_assert_held(&qp->s_lock);
 272         ps->s_txreq = get_txreq(ps->dev, qp);
 273         if (IS_ERR(ps->s_txreq))
 274                 goto bail_no_tx;
 275
 276         ohdr = &ps->s_txreq->phdr.hdr.u.oth;
 277         if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
 278                 ohdr = &ps->s_txreq->phdr.hdr.u.l.oth;
 279
 280         /* Sending responses has higher priority over sending requests. */
 281         if ((qp->s_flags & RVT_S_RESP_PENDING) &&
 282             make_rc_ack(dev, qp, ohdr, ps))
 283                 return 1;
 284
 285         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
 286                 if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
 287                         goto bail;
 288                 /* We are in the error state, flush the work request. */
 289                 smp_read_barrier_depends(); /* see post_one_send() */
 290                 if (qp->s_last == READ_ONCE(qp->s_head))
 291                         goto bail;
 292                 /* If DMAs are in progress, we can't flush immediately. */
 293                 if (iowait_sdma_pending(&priv->s_iowait)) {
 294                         qp->s_flags |= RVT_S_WAIT_DMA;
 295                         goto bail;
 296                 }
 297                 clear_ahg(qp);
 298                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
 299                 hfi1_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
 300                         IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
 301                 /* will get called again */
 302                 goto done_free_tx;
 303         }
 304
 305         if (qp->s_flags & (RVT_S_WAIT_RNR | RVT_S_WAIT_ACK))
 306                 goto bail;
 307
 308         if (cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) {
 309                 if (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) {
 310                         qp->s_flags |= RVT_S_WAIT_PSN;
 311                         goto bail;
 312                 }
 313                 qp->s_sending_psn = qp->s_psn;
 314                 qp->s_sending_hpsn = qp->s_psn - 1;
 315         }
 316
 317         /* Send a request. */
 318         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
 319         switch (qp->s_state) {
 320         default:
 321                 if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK))
 322                         goto bail;
 323                 /*
 324                  * Resend an old request or start a new one.
 325                  *
 326                  * We keep track of the current SWQE so that
 327                  * we don't reset the "furthest progress" state
 328                  * if we need to back up.
 329                  */
 330                 newreq = 0;
 331                 if (qp->s_cur == qp->s_tail) {
 332                         /* Check if send work queue is empty. */
 333                         smp_read_barrier_depends(); /* see post_one_send() */
 334                         if (qp->s_tail == READ_ONCE(qp->s_head)) {
 335                                 clear_ahg(qp);
 336                                 goto bail;
 337                         }
 338                         /*
 339                          * If a fence is requested, wait for previous
 340                          * RDMA read and atomic operations to finish.
 341                          */
 342                         if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
 343                             qp->s_num_rd_atomic) {
 344                                 qp->s_flags |= RVT_S_WAIT_FENCE;
 345                                 goto bail;
 346                         }
 347                         /*
 348                          * Local operations are processed immediately
 349                          * after all prior requests have completed
 350                          */
 351                         if (wqe->wr.opcode == IB_WR_REG_MR ||
 352                             wqe->wr.opcode == IB_WR_LOCAL_INV) {
 353                                 int local_ops = 0;
 354                                 int err = 0;
 355
 356                                 if (qp->s_last != qp->s_cur)
 357                                         goto bail;
 358                                 if (++qp->s_cur == qp->s_size)
 359                                         qp->s_cur = 0;
 360                                 if (++qp->s_tail == qp->s_size)
 361                                         qp->s_tail = 0;
 362                                 if (!(wqe->wr.send_flags &
 363                                       RVT_SEND_COMPLETION_ONLY)) {
 364                                         err = rvt_invalidate_rkey(
 365                                                 qp,
 366                                                 wqe->wr.ex.invalidate_rkey);
 367                                         local_ops = 1;
 368                                 }
 369                                 hfi1_send_complete(qp, wqe,
 370                                                    err ? IB_WC_LOC_PROT_ERR
 371                                                        : IB_WC_SUCCESS);
 372                                 if (local_ops)
 373                                         atomic_dec(&qp->local_ops_pending);
 374                                 qp->s_hdrwords = 0;
 375                                 goto done_free_tx;
 376                         }
 377
 378                         newreq = 1;
 379                         qp->s_psn = wqe->psn;
 380                 }
 381                 /*
 382                  * Note that we have to be careful not to modify the
 383                  * original work request since we may need to resend
 384                  * it.
 385                  */
 386                 len = wqe->length;
 387                 ss = &qp->s_sge;
 388                 bth2 = mask_psn(qp->s_psn);
 389                 switch (wqe->wr.opcode) {
 390                 case IB_WR_SEND:
 391                 case IB_WR_SEND_WITH_IMM:
 392                 case IB_WR_SEND_WITH_INV:
 393                         /* If no credit, return. */
 394                         if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
 395                             rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
 396                                 qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
 397                                 goto bail;
 398                         }
 399                         if (len > pmtu) {
 400                                 qp->s_state = OP(SEND_FIRST);
 401                                 len = pmtu;
 402                                 break;
 403                         }
 404                         if (wqe->wr.opcode == IB_WR_SEND) {
 405                                 qp->s_state = OP(SEND_ONLY);
 406                         } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 407                                 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
 408                                 /* Immediate data comes after the BTH */
 409                                 ohdr->u.imm_data = wqe->wr.ex.imm_data;
 410                                 hwords += 1;
 411                         } else {
 412                                 qp->s_state = OP(SEND_ONLY_WITH_INVALIDATE);
 413                                 /* Invalidate rkey comes after the BTH */
 414                                 ohdr->u.ieth = cpu_to_be32(
 415                                                 wqe->wr.ex.invalidate_rkey);
 416                                 hwords += 1;
 417                         }
 418                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 419                                 bth0 |= IB_BTH_SOLICITED;
 420                         bth2 |= IB_BTH_REQ_ACK;
 421                         if (++qp->s_cur == qp->s_size)
 422                                 qp->s_cur = 0;
 423                         break;
 424
 425                 case IB_WR_RDMA_WRITE:
 426                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 427                                 qp->s_lsn++;
 428                         /* FALLTHROUGH */
 429                 case IB_WR_RDMA_WRITE_WITH_IMM:
 430                         /* If no credit, return. */
 431                         if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
 432                             rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
 433                                 qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
 434                                 goto bail;
 435                         }
 436                         put_ib_reth_vaddr(
 437                                 wqe->rdma_wr.remote_addr,
 438                                 &ohdr->u.rc.reth);
 439                         ohdr->u.rc.reth.rkey =
 440                                 cpu_to_be32(wqe->rdma_wr.rkey);
 441                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 442                         hwords += sizeof(struct ib_reth) / sizeof(u32);
 443                         if (len > pmtu) {
 444                                 qp->s_state = OP(RDMA_WRITE_FIRST);
 445                                 len = pmtu;
 446                                 break;
 447                         }
 448                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 449                                 qp->s_state = OP(RDMA_WRITE_ONLY);
 450                         } else {
 451                                 qp->s_state =
 452                                         OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
 453                                 /* Immediate data comes after RETH */
 454                                 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
 455                                 hwords += 1;
 456                                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 457                                         bth0 |= IB_BTH_SOLICITED;
 458                         }
 459                         bth2 |= IB_BTH_REQ_ACK;
 460                         if (++qp->s_cur == qp->s_size)
 461                                 qp->s_cur = 0;
 462                         break;
 463
 464                 case IB_WR_RDMA_READ:
 465                         /*
 466                          * Don't allow more operations to be started
 467                          * than the QP limits allow.
 468                          */
 469                         if (newreq) {
 470                                 if (qp->s_num_rd_atomic >=
 471                                     qp->s_max_rd_atomic) {
 472                                         qp->s_flags |= RVT_S_WAIT_RDMAR;
 473                                         goto bail;
 474                                 }
 475                                 qp->s_num_rd_atomic++;
 476                                 if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 477                                         qp->s_lsn++;
 478                         }
 479                         put_ib_reth_vaddr(
 480                                 wqe->rdma_wr.remote_addr,
 481                                 &ohdr->u.rc.reth);
 482                         ohdr->u.rc.reth.rkey =
 483                                 cpu_to_be32(wqe->rdma_wr.rkey);
 484                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 485                         qp->s_state = OP(RDMA_READ_REQUEST);
 486                         hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
 487                         ss = NULL;
 488                         len = 0;
 489                         bth2 |= IB_BTH_REQ_ACK;
 490                         if (++qp->s_cur == qp->s_size)
 491                                 qp->s_cur = 0;
 492                         break;
 493
 494                 case IB_WR_ATOMIC_CMP_AND_SWP:
 495                 case IB_WR_ATOMIC_FETCH_AND_ADD:
 496                         /*
 497                          * Don't allow more operations to be started
 498                          * than the QP limits allow.
 499                          */
 500                         if (newreq) {
 501                                 if (qp->s_num_rd_atomic >=
 502                                     qp->s_max_rd_atomic) {
 503                                         qp->s_flags |= RVT_S_WAIT_RDMAR;
 504                                         goto bail;
 505                                 }
 506                                 qp->s_num_rd_atomic++;
 507                                 if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 508                                         qp->s_lsn++;
 509                         }
 510                         if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) {
 511                                 qp->s_state = OP(COMPARE_SWAP);
 512                                 put_ib_ateth_swap(wqe->atomic_wr.swap,
 513                                                   &ohdr->u.atomic_eth);
 514                                 put_ib_ateth_compare(wqe->atomic_wr.compare_add,
 515                                                      &ohdr->u.atomic_eth);
 516                         } else {
 517                                 qp->s_state = OP(FETCH_ADD);
 518                                 put_ib_ateth_swap(wqe->atomic_wr.compare_add,
 519                                                   &ohdr->u.atomic_eth);
 520                                 put_ib_ateth_compare(0, &ohdr->u.atomic_eth);
 521                         }
 522                         put_ib_ateth_vaddr(wqe->atomic_wr.remote_addr,
 523                                            &ohdr->u.atomic_eth);
 524                         ohdr->u.atomic_eth.rkey = cpu_to_be32(
 525                                 wqe->atomic_wr.rkey);
 526                         hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
 527                         ss = NULL;
 528                         len = 0;
 529                         bth2 |= IB_BTH_REQ_ACK;
 530                         if (++qp->s_cur == qp->s_size)
 531                                 qp->s_cur = 0;
 532                         break;
 533
 534                 default:
 535                         goto bail;
 536                 }
 537                 qp->s_sge.sge = wqe->sg_list[0];
 538                 qp->s_sge.sg_list = wqe->sg_list + 1;
 539                 qp->s_sge.num_sge = wqe->wr.num_sge;
 540                 qp->s_sge.total_len = wqe->length;
 541                 qp->s_len = wqe->length;
 542                 if (newreq) {
 543                         qp->s_tail++;
 544                         if (qp->s_tail >= qp->s_size)
 545                                 qp->s_tail = 0;
 546                 }
 547                 if (wqe->wr.opcode == IB_WR_RDMA_READ)
 548                         qp->s_psn = wqe->lpsn + 1;
 549                 else
 550                         qp->s_psn++;
 551                 break;
 552
 553         case OP(RDMA_READ_RESPONSE_FIRST):
 554                 /*
 555                  * qp->s_state is normally set to the opcode of the
 556                  * last packet constructed for new requests and therefore
 557                  * is never set to RDMA read response.
 558                  * RDMA_READ_RESPONSE_FIRST is used by the ACK processing
 559                  * thread to indicate a SEND needs to be restarted from an
 560                  * earlier PSN without interfering with the sending thread.
 561                  * See restart_rc().
 562                  */
 563                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
 564                 /* FALLTHROUGH */
 565         case OP(SEND_FIRST):
 566                 qp->s_state = OP(SEND_MIDDLE);
 567                 /* FALLTHROUGH */
 568         case OP(SEND_MIDDLE):
 569                 bth2 = mask_psn(qp->s_psn++);
 570                 ss = &qp->s_sge;
 571                 len = qp->s_len;
 572                 if (len > pmtu) {
 573                         len = pmtu;
 574                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 575                         break;
 576                 }
 577                 if (wqe->wr.opcode == IB_WR_SEND) {
 578                         qp->s_state = OP(SEND_LAST);
 579                 } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 580                         qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
 581                         /* Immediate data comes after the BTH */
 582                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 583                         hwords += 1;
 584                 } else {
 585                         qp->s_state = OP(SEND_LAST_WITH_INVALIDATE);
 586                         /* invalidate data comes after the BTH */
 587                         ohdr->u.ieth = cpu_to_be32(wqe->wr.ex.invalidate_rkey);
 588                         hwords += 1;
 589                 }
 590                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 591                         bth0 |= IB_BTH_SOLICITED;
 592                 bth2 |= IB_BTH_REQ_ACK;
 593                 qp->s_cur++;
 594                 if (qp->s_cur >= qp->s_size)
 595                         qp->s_cur = 0;
 596                 break;
 597
 598         case OP(RDMA_READ_RESPONSE_LAST):
 599                 /*
 600                  * qp->s_state is normally set to the opcode of the
 601                  * last packet constructed for new requests and therefore
 602                  * is never set to RDMA read response.
 603                  * RDMA_READ_RESPONSE_LAST is used by the ACK processing
 604                  * thread to indicate a RDMA write needs to be restarted from
 605                  * an earlier PSN without interfering with the sending thread.
 606                  * See restart_rc().
 607                  */
 608                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
 609                 /* FALLTHROUGH */
 610         case OP(RDMA_WRITE_FIRST):
 611                 qp->s_state = OP(RDMA_WRITE_MIDDLE);
 612                 /* FALLTHROUGH */
 613         case OP(RDMA_WRITE_MIDDLE):
 614                 bth2 = mask_psn(qp->s_psn++);
 615                 ss = &qp->s_sge;
 616                 len = qp->s_len;
 617                 if (len > pmtu) {
 618                         len = pmtu;
 619                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 620                         break;
 621                 }
 622                 if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 623                         qp->s_state = OP(RDMA_WRITE_LAST);
 624                 } else {
 625                         qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
 626                         /* Immediate data comes after the BTH */
 627                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 628                         hwords += 1;
 629                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 630                                 bth0 |= IB_BTH_SOLICITED;
 631                 }
 632                 bth2 |= IB_BTH_REQ_ACK;
 633                 qp->s_cur++;
 634                 if (qp->s_cur >= qp->s_size)
 635                         qp->s_cur = 0;
 636                 break;
 637
 638         case OP(RDMA_READ_RESPONSE_MIDDLE):
 639                 /*
 640                  * qp->s_state is normally set to the opcode of the
 641                  * last packet constructed for new requests and therefore
 642                  * is never set to RDMA read response.
 643                  * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing
 644                  * thread to indicate a RDMA read needs to be restarted from
 645                  * an earlier PSN without interfering with the sending thread.
 646                  * See restart_rc().
 647                  */
 648                 len = (delta_psn(qp->s_psn, wqe->psn)) * pmtu;
 649                 put_ib_reth_vaddr(
 650                         wqe->rdma_wr.remote_addr + len,
 651                         &ohdr->u.rc.reth);
 652                 ohdr->u.rc.reth.rkey =
 653                         cpu_to_be32(wqe->rdma_wr.rkey);
 654                 ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len);
 655                 qp->s_state = OP(RDMA_READ_REQUEST);
 656                 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
 657                 bth2 = mask_psn(qp->s_psn) | IB_BTH_REQ_ACK;
 658                 qp->s_psn = wqe->lpsn + 1;
 659                 ss = NULL;
 660                 len = 0;
 661                 qp->s_cur++;
 662                 if (qp->s_cur == qp->s_size)
 663                         qp->s_cur = 0;
 664                 break;
 665         }
 666         qp->s_sending_hpsn = bth2;
 667         delta = delta_psn(bth2, wqe->psn);
 668         if (delta && delta % HFI1_PSN_CREDIT == 0)
 669                 bth2 |= IB_BTH_REQ_ACK;
 670         if (qp->s_flags & RVT_S_SEND_ONE) {
 671                 qp->s_flags &= ~RVT_S_SEND_ONE;
 672                 qp->s_flags |= RVT_S_WAIT_ACK;
 673                 bth2 |= IB_BTH_REQ_ACK;
 674         }
 675         qp->s_len -= len;
 676         qp->s_hdrwords = hwords;
 677         ps->s_txreq->sde = priv->s_sde;
 678         ps->s_txreq->ss = ss;
 679         ps->s_txreq->s_cur_size = len;
 680         hfi1_make_ruc_header(
 681                 qp,
 682                 ohdr,
 683                 bth0 | (qp->s_state << 24),
 684                 bth2,
 685                 middle,
 686                 ps);
 687         /* pbc */
 688         ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2;
 689         return 1;
 690
 691 done_free_tx:
 692         hfi1_put_txreq(ps->s_txreq);
 693         ps->s_txreq = NULL;
 694         return 1;
 695
 696 bail:
 697         hfi1_put_txreq(ps->s_txreq);
 698
 699 bail_no_tx:
 700         ps->s_txreq = NULL;
 701         qp->s_flags &= ~RVT_S_BUSY;
 702         qp->s_hdrwords = 0;
 703         return 0;
 704 }
 705
 706 /**
 707  * hfi1_send_rc_ack - Construct an ACK packet and send it
 708  * @qp: a pointer to the QP
 709  *
 710  * This is called from hfi1_rc_rcv() and handle_receive_interrupt().
 711  * Note that RDMA reads and atomics are handled in the
 712  * send side QP state and send engine.
 713  */
 714 void hfi1_send_rc_ack(struct hfi1_ctxtdata *rcd, struct rvt_qp *qp,
 715                       int is_fecn)
 716 {
 717         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
 718         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
 719         u64 pbc, pbc_flags = 0;
 720         u16 lrh0;
 721         u16 sc5;
 722         u32 bth0;
 723         u32 hwords;
 724         u32 vl, plen;
 725         struct send_context *sc;
 726         struct pio_buf *pbuf;
 727         struct ib_header hdr;
 728         struct ib_other_headers *ohdr;
 729         unsigned long flags;
 730
 731         /* clear the defer count */
 732         qp->r_adefered = 0;
 733
 734         /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
 735         if (qp->s_flags & RVT_S_RESP_PENDING)
 736                 goto queue_ack;
 737
 738         /* Ensure s_rdma_ack_cnt changes are committed */
 739         smp_read_barrier_depends();
 740         if (qp->s_rdma_ack_cnt)
 741                 goto queue_ack;
 742
 743         /* Construct the header */
 744         /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4 */
 745         hwords = 6;
 746         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)) {
 747                 hwords += hfi1_make_grh(ibp, &hdr.u.l.grh,
 748                                         rdma_ah_read_grh(&qp->remote_ah_attr),
 749                                         hwords, 0);
 750                 ohdr = &hdr.u.l.oth;
 751                 lrh0 = HFI1_LRH_GRH;
 752         } else {
 753                 ohdr = &hdr.u.oth;
 754                 lrh0 = HFI1_LRH_BTH;
 755         }
 756         /* read pkey_index w/o lock (its atomic) */
 757         bth0 = hfi1_get_pkey(ibp, qp->s_pkey_index) | (OP(ACKNOWLEDGE) << 24);
 758         if (qp->s_mig_state == IB_MIG_MIGRATED)
 759                 bth0 |= IB_BTH_MIG_REQ;
 760         if (qp->r_nak_state)
 761                 ohdr->u.aeth = cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
 762                                             (qp->r_nak_state <<
 763                                              IB_AETH_CREDIT_SHIFT));
 764         else
 765                 ohdr->u.aeth = rvt_compute_aeth(qp);
 766         sc5 = ibp->sl_to_sc[rdma_ah_get_sl(&qp->remote_ah_attr)];
 767         /* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
 768         pbc_flags |= ((!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT);
 769         lrh0 |= (sc5 & 0xf) << 12 | (rdma_ah_get_sl(&qp->remote_ah_attr)
 770                                      & 0xf) << 4;
 771         hdr.lrh[0] = cpu_to_be16(lrh0);
 772         hdr.lrh[1] = cpu_to_be16(rdma_ah_get_dlid(&qp->remote_ah_attr));
 773         hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC);
 774         hdr.lrh[3] = cpu_to_be16(ppd->lid |
 775                                  rdma_ah_get_path_bits(&qp->remote_ah_attr));
 776         ohdr->bth[0] = cpu_to_be32(bth0);
 777         ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
 778         ohdr->bth[1] |= cpu_to_be32((!!is_fecn) << IB_BECN_SHIFT);
 779         ohdr->bth[2] = cpu_to_be32(mask_psn(qp->r_ack_psn));
 780
 781         /* Don't try to send ACKs if the link isn't ACTIVE */
 782         if (driver_lstate(ppd) != IB_PORT_ACTIVE)
 783                 return;
 784
 785         sc = rcd->sc;
 786         plen = 2 /* PBC */ + hwords;
 787         vl = sc_to_vlt(ppd->dd, sc5);
 788         pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps, vl, plen);
 789
 790         pbuf = sc_buffer_alloc(sc, plen, NULL, NULL);
 791         if (!pbuf) {
 792                 /*
 793                  * We have no room to send at the moment.  Pass
 794                  * responsibility for sending the ACK to the send engine
 795                  * so that when enough buffer space becomes available,
 796                  * the ACK is sent ahead of other outgoing packets.
 797                  */
 798                 goto queue_ack;
 799         }
 800
 801         trace_ack_output_ibhdr(dd_from_ibdev(qp->ibqp.device), &hdr);
 802
 803         /* write the pbc and data */
 804         ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc, &hdr, hwords);
 805
 806         return;
 807
 808 queue_ack:
 809         spin_lock_irqsave(&qp->s_lock, flags);
 810         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
 811                 goto unlock;
 812         this_cpu_inc(*ibp->rvp.rc_qacks);
 813         qp->s_flags |= RVT_S_ACK_PENDING | RVT_S_RESP_PENDING;
 814         qp->s_nak_state = qp->r_nak_state;
 815         qp->s_ack_psn = qp->r_ack_psn;
 816         if (is_fecn)
 817                 qp->s_flags |= RVT_S_ECN;
 818
 819         /* Schedule the send engine. */
 820         hfi1_schedule_send(qp);
 821 unlock:
 822         spin_unlock_irqrestore(&qp->s_lock, flags);
 823 }
 824
 825 /**
 826  * reset_psn - reset the QP state to send starting from PSN
 827  * @qp: the QP
 828  * @psn: the packet sequence number to restart at
 829  *
 830  * This is called from hfi1_rc_rcv() to process an incoming RC ACK
 831  * for the given QP.
 832  * Called at interrupt level with the QP s_lock held.
 833  */
 834 static void reset_psn(struct rvt_qp *qp, u32 psn)
 835 {
 836         u32 n = qp->s_acked;
 837         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, n);
 838         u32 opcode;
 839
 840         lockdep_assert_held(&qp->s_lock);
 841         qp->s_cur = n;
 842
 843         /*
 844          * If we are starting the request from the beginning,
 845          * let the normal send code handle initialization.
 846          */
 847         if (cmp_psn(psn, wqe->psn) <= 0) {
 848                 qp->s_state = OP(SEND_LAST);
 849                 goto done;
 850         }
 851
 852         /* Find the work request opcode corresponding to the given PSN. */
 853         opcode = wqe->wr.opcode;
 854         for (;;) {
 855                 int diff;
 856
 857                 if (++n == qp->s_size)
 858                         n = 0;
 859                 if (n == qp->s_tail)
 860                         break;
 861                 wqe = rvt_get_swqe_ptr(qp, n);
 862                 diff = cmp_psn(psn, wqe->psn);
 863                 if (diff < 0)
 864                         break;
 865                 qp->s_cur = n;
 866                 /*
 867                  * If we are starting the request from the beginning,
 868                  * let the normal send code handle initialization.
 869                  */
 870                 if (diff == 0) {
 871                         qp->s_state = OP(SEND_LAST);
 872                         goto done;
 873                 }
 874                 opcode = wqe->wr.opcode;
 875         }
 876
 877         /*
 878          * Set the state to restart in the middle of a request.
 879          * Don't change the s_sge, s_cur_sge, or s_cur_size.
 880          * See hfi1_make_rc_req().
 881          */
 882         switch (opcode) {
 883         case IB_WR_SEND:
 884         case IB_WR_SEND_WITH_IMM:
 885                 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
 886                 break;
 887
 888         case IB_WR_RDMA_WRITE:
 889         case IB_WR_RDMA_WRITE_WITH_IMM:
 890                 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
 891                 break;
 892
 893         case IB_WR_RDMA_READ:
 894                 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
 895                 break;
 896
 897         default:
 898                 /*
 899                  * This case shouldn't happen since its only
 900                  * one PSN per req.
 901                  */
 902                 qp->s_state = OP(SEND_LAST);
 903         }
 904 done:
 905         qp->s_psn = psn;
 906         /*
 907          * Set RVT_S_WAIT_PSN as rc_complete() may start the timer
 908          * asynchronously before the send engine can get scheduled.
 909          * Doing it in hfi1_make_rc_req() is too late.
 910          */
 911         if ((cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) &&
 912             (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0))
 913                 qp->s_flags |= RVT_S_WAIT_PSN;
 914         qp->s_flags &= ~RVT_S_AHG_VALID;
 915 }
 916
 917 /*
 918  * Back up requester to resend the last un-ACKed request.
 919  * The QP r_lock and s_lock should be held and interrupts disabled.
 920  */
 921 void hfi1_restart_rc(struct rvt_qp *qp, u32 psn, int wait)
 922 {
 923         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
 924         struct hfi1_ibport *ibp;
 925
 926         lockdep_assert_held(&qp->r_lock);
 927         lockdep_assert_held(&qp->s_lock);
 928         if (qp->s_retry == 0) {
 929                 if (qp->s_mig_state == IB_MIG_ARMED) {
 930                         hfi1_migrate_qp(qp);
 931                         qp->s_retry = qp->s_retry_cnt;
 932                 } else if (qp->s_last == qp->s_acked) {
 933                         hfi1_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR);
 934                         rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
 935                         return;
 936                 } else { /* need to handle delayed completion */
 937                         return;
 938                 }
 939         } else {
 940                 qp->s_retry--;
 941         }
 942
 943         ibp = to_iport(qp->ibqp.device, qp->port_num);
 944         if (wqe->wr.opcode == IB_WR_RDMA_READ)
 945                 ibp->rvp.n_rc_resends++;
 946         else
 947                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
 948
 949         qp->s_flags &= ~(RVT_S_WAIT_FENCE | RVT_S_WAIT_RDMAR |
 950                          RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_PSN |
 951                          RVT_S_WAIT_ACK);
 952         if (wait)
 953                 qp->s_flags |= RVT_S_SEND_ONE;
 954         reset_psn(qp, psn);
 955 }
 956
 957 /*
 958  * Set qp->s_sending_psn to the next PSN after the given one.
 959  * This would be psn+1 except when RDMA reads are present.
 960  */
 961 static void reset_sending_psn(struct rvt_qp *qp, u32 psn)
 962 {
 963         struct rvt_swqe *wqe;
 964         u32 n = qp->s_last;
 965
 966         lockdep_assert_held(&qp->s_lock);
 967         /* Find the work request corresponding to the given PSN. */
 968         for (;;) {
 969                 wqe = rvt_get_swqe_ptr(qp, n);
 970                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
 971                         if (wqe->wr.opcode == IB_WR_RDMA_READ)
 972                                 qp->s_sending_psn = wqe->lpsn + 1;
 973                         else
 974                                 qp->s_sending_psn = psn + 1;
 975                         break;
 976                 }
 977                 if (++n == qp->s_size)
 978                         n = 0;
 979                 if (n == qp->s_tail)
 980                         break;
 981         }
 982 }
 983
 984 /*
 985  * This should be called with the QP s_lock held and interrupts disabled.
 986  */
 987 void hfi1_rc_send_complete(struct rvt_qp *qp, struct ib_header *hdr)
 988 {
 989         struct ib_other_headers *ohdr;
 990         struct rvt_swqe *wqe;
 991         u32 opcode;
 992         u32 psn;
 993
 994         lockdep_assert_held(&qp->s_lock);
 995         if (!(ib_rvt_state_ops[qp->state] & RVT_SEND_OR_FLUSH_OR_RECV_OK))
 996                 return;
 997
 998         /* Find out where the BTH is */
 999         if (ib_get_lnh(hdr) == HFI1_LRH_BTH)
1000                 ohdr = &hdr->u.oth;
1001         else
1002                 ohdr = &hdr->u.l.oth;
1003
1004         opcode = ib_bth_get_opcode(ohdr);
1005         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1006             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
1007                 WARN_ON(!qp->s_rdma_ack_cnt);
1008                 qp->s_rdma_ack_cnt--;
1009                 return;
1010         }
1011
1012         psn = be32_to_cpu(ohdr->bth[2]);
1013         reset_sending_psn(qp, psn);
1014
1015         /*
1016          * Start timer after a packet requesting an ACK has been sent and
1017          * there are still requests that haven't been acked.
1018          */
1019         if ((psn & IB_BTH_REQ_ACK) && qp->s_acked != qp->s_tail &&
1020             !(qp->s_flags &
1021                 (RVT_S_TIMER | RVT_S_WAIT_RNR | RVT_S_WAIT_PSN)) &&
1022                 (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
1023                 rvt_add_retry_timer(qp);
1024
1025         while (qp->s_last != qp->s_acked) {
1026                 u32 s_last;
1027
1028                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
1029                 if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 &&
1030                     cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
1031                         break;
1032                 s_last = qp->s_last;
1033                 trace_hfi1_qp_send_completion(qp, wqe, s_last);
1034                 if (++s_last >= qp->s_size)
1035                         s_last = 0;
1036                 qp->s_last = s_last;
1037                 /* see post_send() */
1038                 barrier();
1039                 rvt_put_swqe(wqe);
1040                 rvt_qp_swqe_complete(qp,
1041                                      wqe,
1042                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1043                                      IB_WC_SUCCESS);
1044         }
1045         /*
1046          * If we were waiting for sends to complete before re-sending,
1047          * and they are now complete, restart sending.
1048          */
1049         trace_hfi1_sendcomplete(qp, psn);
1050         if (qp->s_flags & RVT_S_WAIT_PSN &&
1051             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1052                 qp->s_flags &= ~RVT_S_WAIT_PSN;
1053                 qp->s_sending_psn = qp->s_psn;
1054                 qp->s_sending_hpsn = qp->s_psn - 1;
1055                 hfi1_schedule_send(qp);
1056         }
1057 }
1058
1059 static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
1060 {
1061         qp->s_last_psn = psn;
1062 }
1063
1064 /*
1065  * Generate a SWQE completion.
1066  * This is similar to hfi1_send_complete but has to check to be sure
1067  * that the SGEs are not being referenced if the SWQE is being resent.
1068  */
1069 static struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
1070                                          struct rvt_swqe *wqe,
1071                                          struct hfi1_ibport *ibp)
1072 {
1073         lockdep_assert_held(&qp->s_lock);
1074         /*
1075          * Don't decrement refcount and don't generate a
1076          * completion if the SWQE is being resent until the send
1077          * is finished.
1078          */
1079         if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 ||
1080             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1081                 u32 s_last;
1082
1083                 rvt_put_swqe(wqe);
1084                 s_last = qp->s_last;
1085                 trace_hfi1_qp_send_completion(qp, wqe, s_last);
1086                 if (++s_last >= qp->s_size)
1087                         s_last = 0;
1088                 qp->s_last = s_last;
1089                 /* see post_send() */
1090                 barrier();
1091                 rvt_qp_swqe_complete(qp,
1092                                      wqe,
1093                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1094                                      IB_WC_SUCCESS);
1095         } else {
1096                 struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1097
1098                 this_cpu_inc(*ibp->rvp.rc_delayed_comp);
1099                 /*
1100                  * If send progress not running attempt to progress
1101                  * SDMA queue.
1102                  */
1103                 if (ppd->dd->flags & HFI1_HAS_SEND_DMA) {
1104                         struct sdma_engine *engine;
1105                         u8 sl = rdma_ah_get_sl(&qp->remote_ah_attr);
1106                         u8 sc5;
1107
1108                         /* For now use sc to find engine */
1109                         sc5 = ibp->sl_to_sc[sl];
1110                         engine = qp_to_sdma_engine(qp, sc5);
1111                         sdma_engine_progress_schedule(engine);
1112                 }
1113         }
1114
1115         qp->s_retry = qp->s_retry_cnt;
1116         update_last_psn(qp, wqe->lpsn);
1117
1118         /*
1119          * If we are completing a request which is in the process of
1120          * being resent, we can stop re-sending it since we know the
1121          * responder has already seen it.
1122          */
1123         if (qp->s_acked == qp->s_cur) {
1124                 if (++qp->s_cur >= qp->s_size)
1125                         qp->s_cur = 0;
1126                 qp->s_acked = qp->s_cur;
1127                 wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1128                 if (qp->s_acked != qp->s_tail) {
1129                         qp->s_state = OP(SEND_LAST);
1130                         qp->s_psn = wqe->psn;
1131                 }
1132         } else {
1133                 if (++qp->s_acked >= qp->s_size)
1134                         qp->s_acked = 0;
1135                 if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur)
1136                         qp->s_draining = 0;
1137                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1138         }
1139         return wqe;
1140 }
1141
1142 /**
1143  * do_rc_ack - process an incoming RC ACK
1144  * @qp: the QP the ACK came in on
1145  * @psn: the packet sequence number of the ACK
1146  * @opcode: the opcode of the request that resulted in the ACK
1147  *
1148  * This is called from rc_rcv_resp() to process an incoming RC ACK
1149  * for the given QP.
1150  * May be called at interrupt level, with the QP s_lock held.
1151  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
1152  */
1153 static int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
1154                      u64 val, struct hfi1_ctxtdata *rcd)
1155 {
1156         struct hfi1_ibport *ibp;
1157         enum ib_wc_status status;
1158         struct rvt_swqe *wqe;
1159         int ret = 0;
1160         u32 ack_psn;
1161         int diff;
1162
1163         lockdep_assert_held(&qp->s_lock);
1164         /*
1165          * Note that NAKs implicitly ACK outstanding SEND and RDMA write
1166          * requests and implicitly NAK RDMA read and atomic requests issued
1167          * before the NAK'ed request.  The MSN won't include the NAK'ed
1168          * request but will include an ACK'ed request(s).
1169          */
1170         ack_psn = psn;
1171         if (aeth >> IB_AETH_NAK_SHIFT)
1172                 ack_psn--;
1173         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1174         ibp = rcd_to_iport(rcd);
1175
1176         /*
1177          * The MSN might be for a later WQE than the PSN indicates so
1178          * only complete WQEs that the PSN finishes.
1179          */
1180         while ((diff = delta_psn(ack_psn, wqe->lpsn)) >= 0) {
1181                 /*
1182                  * RDMA_READ_RESPONSE_ONLY is a special case since
1183                  * we want to generate completion events for everything
1184                  * before the RDMA read, copy the data, then generate
1185                  * the completion for the read.
1186                  */
1187                 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
1188                     opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
1189                     diff == 0) {
1190                         ret = 1;
1191                         goto bail_stop;
1192                 }
1193                 /*
1194                  * If this request is a RDMA read or atomic, and the ACK is
1195                  * for a later operation, this ACK NAKs the RDMA read or
1196                  * atomic.  In other words, only a RDMA_READ_LAST or ONLY
1197                  * can ACK a RDMA read and likewise for atomic ops.  Note
1198                  * that the NAK case can only happen if relaxed ordering is
1199                  * used and requests are sent after an RDMA read or atomic
1200                  * is sent but before the response is received.
1201                  */
1202                 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
1203                      (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
1204                     ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1205                       wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
1206                      (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) {
1207                         /* Retry this request. */
1208                         if (!(qp->r_flags & RVT_R_RDMAR_SEQ)) {
1209                                 qp->r_flags |= RVT_R_RDMAR_SEQ;
1210                                 hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
1211                                 if (list_empty(&qp->rspwait)) {
1212                                         qp->r_flags |= RVT_R_RSP_SEND;
1213                                         rvt_get_qp(qp);
1214                                         list_add_tail(&qp->rspwait,
1215                                                       &rcd->qp_wait_list);
1216                                 }
1217                         }
1218                         /*
1219                          * No need to process the ACK/NAK since we are
1220                          * restarting an earlier request.
1221                          */
1222                         goto bail_stop;
1223                 }
1224                 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1225                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
1226                         u64 *vaddr = wqe->sg_list[0].vaddr;
1227                         *vaddr = val;
1228                 }
1229                 if (qp->s_num_rd_atomic &&
1230                     (wqe->wr.opcode == IB_WR_RDMA_READ ||
1231                      wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1232                      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
1233                         qp->s_num_rd_atomic--;
1234                         /* Restart sending task if fence is complete */
1235                         if ((qp->s_flags & RVT_S_WAIT_FENCE) &&
1236                             !qp->s_num_rd_atomic) {
1237                                 qp->s_flags &= ~(RVT_S_WAIT_FENCE |
1238                                                  RVT_S_WAIT_ACK);
1239                                 hfi1_schedule_send(qp);
1240                         } else if (qp->s_flags & RVT_S_WAIT_RDMAR) {
1241                                 qp->s_flags &= ~(RVT_S_WAIT_RDMAR |
1242                                                  RVT_S_WAIT_ACK);
1243                                 hfi1_schedule_send(qp);
1244                         }
1245                 }
1246                 wqe = do_rc_completion(qp, wqe, ibp);
1247                 if (qp->s_acked == qp->s_tail)
1248                         break;
1249         }
1250
1251         switch (aeth >> IB_AETH_NAK_SHIFT) {
1252         case 0:         /* ACK */
1253                 this_cpu_inc(*ibp->rvp.rc_acks);
1254                 if (qp->s_acked != qp->s_tail) {
1255                         /*
1256                          * We are expecting more ACKs so
1257                          * mod the retry timer.
1258                          */
1259                         rvt_mod_retry_timer(qp);
1260                         /*
1261                          * We can stop re-sending the earlier packets and
1262                          * continue with the next packet the receiver wants.
1263                          */
1264                         if (cmp_psn(qp->s_psn, psn) <= 0)
1265                                 reset_psn(qp, psn + 1);
1266                 } else {
1267                         /* No more acks - kill all timers */
1268                         rvt_stop_rc_timers(qp);
1269                         if (cmp_psn(qp->s_psn, psn) <= 0) {
1270                                 qp->s_state = OP(SEND_LAST);
1271                                 qp->s_psn = psn + 1;
1272                         }
1273                 }
1274                 if (qp->s_flags & RVT_S_WAIT_ACK) {
1275                         qp->s_flags &= ~RVT_S_WAIT_ACK;
1276                         hfi1_schedule_send(qp);
1277                 }
1278                 rvt_get_credit(qp, aeth);
1279                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1280                 qp->s_retry = qp->s_retry_cnt;
1281                 update_last_psn(qp, psn);
1282                 return 1;
1283
1284         case 1:         /* RNR NAK */
1285                 ibp->rvp.n_rnr_naks++;
1286                 if (qp->s_acked == qp->s_tail)
1287                         goto bail_stop;
1288                 if (qp->s_flags & RVT_S_WAIT_RNR)
1289                         goto bail_stop;
1290                 if (qp->s_rnr_retry == 0) {
1291                         status = IB_WC_RNR_RETRY_EXC_ERR;
1292                         goto class_b;
1293                 }
1294                 if (qp->s_rnr_retry_cnt < 7)
1295                         qp->s_rnr_retry--;
1296
1297                 /* The last valid PSN is the previous PSN. */
1298                 update_last_psn(qp, psn - 1);
1299
1300                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
1301
1302                 reset_psn(qp, psn);
1303
1304                 qp->s_flags &= ~(RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_ACK);
1305                 rvt_stop_rc_timers(qp);
1306                 rvt_add_rnr_timer(qp, aeth);
1307                 return 0;
1308
1309         case 3:         /* NAK */
1310                 if (qp->s_acked == qp->s_tail)
1311                         goto bail_stop;
1312                 /* The last valid PSN is the previous PSN. */
1313                 update_last_psn(qp, psn - 1);
1314                 switch ((aeth >> IB_AETH_CREDIT_SHIFT) &
1315                         IB_AETH_CREDIT_MASK) {
1316                 case 0: /* PSN sequence error */
1317                         ibp->rvp.n_seq_naks++;
1318                         /*
1319                          * Back up to the responder's expected PSN.
1320                          * Note that we might get a NAK in the middle of an
1321                          * RDMA READ response which terminates the RDMA
1322                          * READ.
1323                          */
1324                         hfi1_restart_rc(qp, psn, 0);
1325                         hfi1_schedule_send(qp);
1326                         break;
1327
1328                 case 1: /* Invalid Request */
1329                         status = IB_WC_REM_INV_REQ_ERR;
1330                         ibp->rvp.n_other_naks++;
1331                         goto class_b;
1332
1333                 case 2: /* Remote Access Error */
1334                         status = IB_WC_REM_ACCESS_ERR;
1335                         ibp->rvp.n_other_naks++;
1336                         goto class_b;
1337
1338                 case 3: /* Remote Operation Error */
1339                         status = IB_WC_REM_OP_ERR;
1340                         ibp->rvp.n_other_naks++;
1341 class_b:
1342                         if (qp->s_last == qp->s_acked) {
1343                                 hfi1_send_complete(qp, wqe, status);
1344                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1345                         }
1346                         break;
1347
1348                 default:
1349                         /* Ignore other reserved NAK error codes */
1350                         goto reserved;
1351                 }
1352                 qp->s_retry = qp->s_retry_cnt;
1353                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1354                 goto bail_stop;
1355
1356         default:                /* 2: reserved */
1357 reserved:
1358                 /* Ignore reserved NAK codes. */
1359                 goto bail_stop;
1360         }
1361         /* cannot be reached  */
1362 bail_stop:
1363         rvt_stop_rc_timers(qp);
1364         return ret;
1365 }
1366
1367 /*
1368  * We have seen an out of sequence RDMA read middle or last packet.
1369  * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE.
1370  */
1371 static void rdma_seq_err(struct rvt_qp *qp, struct hfi1_ibport *ibp, u32 psn,
1372                          struct hfi1_ctxtdata *rcd)
1373 {
1374         struct rvt_swqe *wqe;
1375
1376         lockdep_assert_held(&qp->s_lock);
1377         /* Remove QP from retry timer */
1378         rvt_stop_rc_timers(qp);
1379
1380         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1381
1382         while (cmp_psn(psn, wqe->lpsn) > 0) {
1383                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1384                     wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1385                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
1386                         break;
1387                 wqe = do_rc_completion(qp, wqe, ibp);
1388         }
1389
1390         ibp->rvp.n_rdma_seq++;
1391         qp->r_flags |= RVT_R_RDMAR_SEQ;
1392         hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
1393         if (list_empty(&qp->rspwait)) {
1394                 qp->r_flags |= RVT_R_RSP_SEND;
1395                 rvt_get_qp(qp);
1396                 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1397         }
1398 }
1399
1400 /**
1401  * rc_rcv_resp - process an incoming RC response packet
1402  * @ibp: the port this packet came in on
1403  * @ohdr: the other headers for this packet
1404  * @data: the packet data
1405  * @tlen: the packet length
1406  * @qp: the QP for this packet
1407  * @opcode: the opcode for this packet
1408  * @psn: the packet sequence number for this packet
1409  * @hdrsize: the header length
1410  * @pmtu: the path MTU
1411  *
1412  * This is called from hfi1_rc_rcv() to process an incoming RC response
1413  * packet for the given QP.
1414  * Called at interrupt level.
1415  */
1416 static void rc_rcv_resp(struct hfi1_ibport *ibp,
1417                         struct ib_other_headers *ohdr,
1418                         void *data, u32 tlen, struct rvt_qp *qp,
1419                         u32 opcode, u32 psn, u32 hdrsize, u32 pmtu,
1420                         struct hfi1_ctxtdata *rcd)
1421 {
1422         struct rvt_swqe *wqe;
1423         enum ib_wc_status status;
1424         unsigned long flags;
1425         int diff;
1426         u32 pad;
1427         u32 aeth;
1428         u64 val;
1429
1430         spin_lock_irqsave(&qp->s_lock, flags);
1431
1432         trace_hfi1_ack(qp, psn);
1433
1434         /* Ignore invalid responses. */
1435         smp_read_barrier_depends(); /* see post_one_send */
1436         if (cmp_psn(psn, READ_ONCE(qp->s_next_psn)) >= 0)
1437                 goto ack_done;
1438
1439         /* Ignore duplicate responses. */
1440         diff = cmp_psn(psn, qp->s_last_psn);
1441         if (unlikely(diff <= 0)) {
1442                 /* Update credits for "ghost" ACKs */
1443                 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
1444                         aeth = be32_to_cpu(ohdr->u.aeth);
1445                         if ((aeth >> IB_AETH_NAK_SHIFT) == 0)
1446                                 rvt_get_credit(qp, aeth);
1447                 }
1448                 goto ack_done;
1449         }
1450
1451         /*
1452          * Skip everything other than the PSN we expect, if we are waiting
1453          * for a reply to a restarted RDMA read or atomic op.
1454          */
1455         if (qp->r_flags & RVT_R_RDMAR_SEQ) {
1456                 if (cmp_psn(psn, qp->s_last_psn + 1) != 0)
1457                         goto ack_done;
1458                 qp->r_flags &= ~RVT_R_RDMAR_SEQ;
1459         }
1460
1461         if (unlikely(qp->s_acked == qp->s_tail))
1462                 goto ack_done;
1463         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1464         status = IB_WC_SUCCESS;
1465
1466         switch (opcode) {
1467         case OP(ACKNOWLEDGE):
1468         case OP(ATOMIC_ACKNOWLEDGE):
1469         case OP(RDMA_READ_RESPONSE_FIRST):
1470                 aeth = be32_to_cpu(ohdr->u.aeth);
1471                 if (opcode == OP(ATOMIC_ACKNOWLEDGE))
1472                         val = ib_u64_get(&ohdr->u.at.atomic_ack_eth);
1473                 else
1474                         val = 0;
1475                 if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) ||
1476                     opcode != OP(RDMA_READ_RESPONSE_FIRST))
1477                         goto ack_done;
1478                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1479                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1480                         goto ack_op_err;
1481                 /*
1482                  * If this is a response to a resent RDMA read, we
1483                  * have to be careful to copy the data to the right
1484                  * location.
1485                  */
1486                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1487                                                   wqe, psn, pmtu);
1488                 goto read_middle;
1489
1490         case OP(RDMA_READ_RESPONSE_MIDDLE):
1491                 /* no AETH, no ACK */
1492                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
1493                         goto ack_seq_err;
1494                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1495                         goto ack_op_err;
1496 read_middle:
1497                 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1498                         goto ack_len_err;
1499                 if (unlikely(pmtu >= qp->s_rdma_read_len))
1500                         goto ack_len_err;
1501
1502                 /*
1503                  * We got a response so update the timeout.
1504                  * 4.096 usec. * (1 << qp->timeout)
1505                  */
1506                 rvt_mod_retry_timer(qp);
1507                 if (qp->s_flags & RVT_S_WAIT_ACK) {
1508                         qp->s_flags &= ~RVT_S_WAIT_ACK;
1509                         hfi1_schedule_send(qp);
1510                 }
1511
1512                 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
1513                         qp->s_retry = qp->s_retry_cnt;
1514
1515                 /*
1516                  * Update the RDMA receive state but do the copy w/o
1517                  * holding the locks and blocking interrupts.
1518                  */
1519                 qp->s_rdma_read_len -= pmtu;
1520                 update_last_psn(qp, psn);
1521                 spin_unlock_irqrestore(&qp->s_lock, flags);
1522                 hfi1_copy_sge(&qp->s_rdma_read_sge, data, pmtu, false, false);
1523                 goto bail;
1524
1525         case OP(RDMA_READ_RESPONSE_ONLY):
1526                 aeth = be32_to_cpu(ohdr->u.aeth);
1527                 if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd))
1528                         goto ack_done;
1529                 /* Get the number of bytes the message was padded by. */
1530                 pad = ib_bth_get_pad(ohdr);
1531                 /*
1532                  * Check that the data size is >= 0 && <= pmtu.
1533                  * Remember to account for ICRC (4).
1534                  */
1535                 if (unlikely(tlen < (hdrsize + pad + 4)))
1536                         goto ack_len_err;
1537                 /*
1538                  * If this is a response to a resent RDMA read, we
1539                  * have to be careful to copy the data to the right
1540                  * location.
1541                  */
1542                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1543                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1544                                                   wqe, psn, pmtu);
1545                 goto read_last;
1546
1547         case OP(RDMA_READ_RESPONSE_LAST):
1548                 /* ACKs READ req. */
1549                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
1550                         goto ack_seq_err;
1551                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1552                         goto ack_op_err;
1553                 /* Get the number of bytes the message was padded by. */
1554                 pad = ib_bth_get_pad(ohdr);
1555                 /*
1556                  * Check that the data size is >= 1 && <= pmtu.
1557                  * Remember to account for ICRC (4).
1558                  */
1559                 if (unlikely(tlen <= (hdrsize + pad + 4)))
1560                         goto ack_len_err;
1561 read_last:
1562                 tlen -= hdrsize + pad + 4;
1563                 if (unlikely(tlen != qp->s_rdma_read_len))
1564                         goto ack_len_err;
1565                 aeth = be32_to_cpu(ohdr->u.aeth);
1566                 hfi1_copy_sge(&qp->s_rdma_read_sge, data, tlen, false, false);
1567                 WARN_ON(qp->s_rdma_read_sge.num_sge);
1568                 (void)do_rc_ack(qp, aeth, psn,
1569                                  OP(RDMA_READ_RESPONSE_LAST), 0, rcd);
1570                 goto ack_done;
1571         }
1572
1573 ack_op_err:
1574         status = IB_WC_LOC_QP_OP_ERR;
1575         goto ack_err;
1576
1577 ack_seq_err:
1578         rdma_seq_err(qp, ibp, psn, rcd);
1579         goto ack_done;
1580
1581 ack_len_err:
1582         status = IB_WC_LOC_LEN_ERR;
1583 ack_err:
1584         if (qp->s_last == qp->s_acked) {
1585                 hfi1_send_complete(qp, wqe, status);
1586                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1587         }
1588 ack_done:
1589         spin_unlock_irqrestore(&qp->s_lock, flags);
1590 bail:
1591         return;
1592 }
1593
1594 static inline void rc_defered_ack(struct hfi1_ctxtdata *rcd,
1595                                   struct rvt_qp *qp)
1596 {
1597         if (list_empty(&qp->rspwait)) {
1598                 qp->r_flags |= RVT_R_RSP_NAK;
1599                 rvt_get_qp(qp);
1600                 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1601         }
1602 }
1603
1604 static inline void rc_cancel_ack(struct rvt_qp *qp)
1605 {
1606         qp->r_adefered = 0;
1607         if (list_empty(&qp->rspwait))
1608                 return;
1609         list_del_init(&qp->rspwait);
1610         qp->r_flags &= ~RVT_R_RSP_NAK;
1611         rvt_put_qp(qp);
1612 }
1613
1614 /**
1615  * rc_rcv_error - process an incoming duplicate or error RC packet
1616  * @ohdr: the other headers for this packet
1617  * @data: the packet data
1618  * @qp: the QP for this packet
1619  * @opcode: the opcode for this packet
1620  * @psn: the packet sequence number for this packet
1621  * @diff: the difference between the PSN and the expected PSN
1622  *
1623  * This is called from hfi1_rc_rcv() to process an unexpected
1624  * incoming RC packet for the given QP.
1625  * Called at interrupt level.
1626  * Return 1 if no more processing is needed; otherwise return 0 to
1627  * schedule a response to be sent.
1628  */
1629 static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
1630                                  struct rvt_qp *qp, u32 opcode, u32 psn,
1631                                  int diff, struct hfi1_ctxtdata *rcd)
1632 {
1633         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
1634         struct rvt_ack_entry *e;
1635         unsigned long flags;
1636         u8 i, prev;
1637         int old_req;
1638
1639         trace_hfi1_rcv_error(qp, psn);
1640         if (diff > 0) {
1641                 /*
1642                  * Packet sequence error.
1643                  * A NAK will ACK earlier sends and RDMA writes.
1644                  * Don't queue the NAK if we already sent one.
1645                  */
1646                 if (!qp->r_nak_state) {
1647                         ibp->rvp.n_rc_seqnak++;
1648                         qp->r_nak_state = IB_NAK_PSN_ERROR;
1649                         /* Use the expected PSN. */
1650                         qp->r_ack_psn = qp->r_psn;
1651                         /*
1652                          * Wait to send the sequence NAK until all packets
1653                          * in the receive queue have been processed.
1654                          * Otherwise, we end up propagating congestion.
1655                          */
1656                         rc_defered_ack(rcd, qp);
1657                 }
1658                 goto done;
1659         }
1660
1661         /*
1662          * Handle a duplicate request.  Don't re-execute SEND, RDMA
1663          * write or atomic op.  Don't NAK errors, just silently drop
1664          * the duplicate request.  Note that r_sge, r_len, and
1665          * r_rcv_len may be in use so don't modify them.
1666          *
1667          * We are supposed to ACK the earliest duplicate PSN but we
1668          * can coalesce an outstanding duplicate ACK.  We have to
1669          * send the earliest so that RDMA reads can be restarted at
1670          * the requester's expected PSN.
1671          *
1672          * First, find where this duplicate PSN falls within the
1673          * ACKs previously sent.
1674          * old_req is true if there is an older response that is scheduled
1675          * to be sent before sending this one.
1676          */
1677         e = NULL;
1678         old_req = 1;
1679         ibp->rvp.n_rc_dupreq++;
1680
1681         spin_lock_irqsave(&qp->s_lock, flags);
1682
1683         for (i = qp->r_head_ack_queue; ; i = prev) {
1684                 if (i == qp->s_tail_ack_queue)
1685                         old_req = 0;
1686                 if (i)
1687                         prev = i - 1;
1688                 else
1689                         prev = HFI1_MAX_RDMA_ATOMIC;
1690                 if (prev == qp->r_head_ack_queue) {
1691                         e = NULL;
1692                         break;
1693                 }
1694                 e = &qp->s_ack_queue[prev];
1695                 if (!e->opcode) {
1696                         e = NULL;
1697                         break;
1698                 }
1699                 if (cmp_psn(psn, e->psn) >= 0) {
1700                         if (prev == qp->s_tail_ack_queue &&
1701                             cmp_psn(psn, e->lpsn) <= 0)
1702                                 old_req = 0;
1703                         break;
1704                 }
1705         }
1706         switch (opcode) {
1707         case OP(RDMA_READ_REQUEST): {
1708                 struct ib_reth *reth;
1709                 u32 offset;
1710                 u32 len;
1711
1712                 /*
1713                  * If we didn't find the RDMA read request in the ack queue,
1714                  * we can ignore this request.
1715                  */
1716                 if (!e || e->opcode != OP(RDMA_READ_REQUEST))
1717                         goto unlock_done;
1718                 /* RETH comes after BTH */
1719                 reth = &ohdr->u.rc.reth;
1720                 /*
1721                  * Address range must be a subset of the original
1722                  * request and start on pmtu boundaries.
1723                  * We reuse the old ack_queue slot since the requester
1724                  * should not back up and request an earlier PSN for the
1725                  * same request.
1726                  */
1727                 offset = delta_psn(psn, e->psn) * qp->pmtu;
1728                 len = be32_to_cpu(reth->length);
1729                 if (unlikely(offset + len != e->rdma_sge.sge_length))
1730                         goto unlock_done;
1731                 if (e->rdma_sge.mr) {
1732                         rvt_put_mr(e->rdma_sge.mr);
1733                         e->rdma_sge.mr = NULL;
1734                 }
1735                 if (len != 0) {
1736                         u32 rkey = be32_to_cpu(reth->rkey);
1737                         u64 vaddr = get_ib_reth_vaddr(reth);
1738                         int ok;
1739
1740                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
1741                                          IB_ACCESS_REMOTE_READ);
1742                         if (unlikely(!ok))
1743                                 goto unlock_done;
1744                 } else {
1745                         e->rdma_sge.vaddr = NULL;
1746                         e->rdma_sge.length = 0;
1747                         e->rdma_sge.sge_length = 0;
1748                 }
1749                 e->psn = psn;
1750                 if (old_req)
1751                         goto unlock_done;
1752                 qp->s_tail_ack_queue = prev;
1753                 break;
1754         }
1755
1756         case OP(COMPARE_SWAP):
1757         case OP(FETCH_ADD): {
1758                 /*
1759                  * If we didn't find the atomic request in the ack queue
1760                  * or the send engine is already backed up to send an
1761                  * earlier entry, we can ignore this request.
1762                  */
1763                 if (!e || e->opcode != (u8)opcode || old_req)
1764                         goto unlock_done;
1765                 qp->s_tail_ack_queue = prev;
1766                 break;
1767         }
1768
1769         default:
1770                 /*
1771                  * Ignore this operation if it doesn't request an ACK
1772                  * or an earlier RDMA read or atomic is going to be resent.
1773                  */
1774                 if (!(psn & IB_BTH_REQ_ACK) || old_req)
1775                         goto unlock_done;
1776                 /*
1777                  * Resend the most recent ACK if this request is
1778                  * after all the previous RDMA reads and atomics.
1779                  */
1780                 if (i == qp->r_head_ack_queue) {
1781                         spin_unlock_irqrestore(&qp->s_lock, flags);
1782                         qp->r_nak_state = 0;
1783                         qp->r_ack_psn = qp->r_psn - 1;
1784                         goto send_ack;
1785                 }
1786
1787                 /*
1788                  * Resend the RDMA read or atomic op which
1789                  * ACKs this duplicate request.
1790                  */
1791                 qp->s_tail_ack_queue = i;
1792                 break;
1793         }
1794         qp->s_ack_state = OP(ACKNOWLEDGE);
1795         qp->s_flags |= RVT_S_RESP_PENDING;
1796         qp->r_nak_state = 0;
1797         hfi1_schedule_send(qp);
1798
1799 unlock_done:
1800         spin_unlock_irqrestore(&qp->s_lock, flags);
1801 done:
1802         return 1;
1803
1804 send_ack:
1805         return 0;
1806 }
1807
1808 static inline void update_ack_queue(struct rvt_qp *qp, unsigned n)
1809 {
1810         unsigned next;
1811
1812         next = n + 1;
1813         if (next > HFI1_MAX_RDMA_ATOMIC)
1814                 next = 0;
1815         qp->s_tail_ack_queue = next;
1816         qp->s_ack_state = OP(ACKNOWLEDGE);
1817 }
1818
1819 static void log_cca_event(struct hfi1_pportdata *ppd, u8 sl, u32 rlid,
1820                           u32 lqpn, u32 rqpn, u8 svc_type)
1821 {
1822         struct opa_hfi1_cong_log_event_internal *cc_event;
1823         unsigned long flags;
1824
1825         if (sl >= OPA_MAX_SLS)
1826                 return;
1827
1828         spin_lock_irqsave(&ppd->cc_log_lock, flags);
1829
1830         ppd->threshold_cong_event_map[sl / 8] |= 1 << (sl % 8);
1831         ppd->threshold_event_counter++;
1832
1833         cc_event = &ppd->cc_events[ppd->cc_log_idx++];
1834         if (ppd->cc_log_idx == OPA_CONG_LOG_ELEMS)
1835                 ppd->cc_log_idx = 0;
1836         cc_event->lqpn = lqpn & RVT_QPN_MASK;
1837         cc_event->rqpn = rqpn & RVT_QPN_MASK;
1838         cc_event->sl = sl;
1839         cc_event->svc_type = svc_type;
1840         cc_event->rlid = rlid;
1841         /* keep timestamp in units of 1.024 usec */
1842         cc_event->timestamp = ktime_to_ns(ktime_get()) / 1024;
1843
1844         spin_unlock_irqrestore(&ppd->cc_log_lock, flags);
1845 }
1846
1847 void process_becn(struct hfi1_pportdata *ppd, u8 sl, u16 rlid, u32 lqpn,
1848                   u32 rqpn, u8 svc_type)
1849 {
1850         struct cca_timer *cca_timer;
1851         u16 ccti, ccti_incr, ccti_timer, ccti_limit;
1852         u8 trigger_threshold;
1853         struct cc_state *cc_state;
1854         unsigned long flags;
1855
1856         if (sl >= OPA_MAX_SLS)
1857                 return;
1858
1859         cc_state = get_cc_state(ppd);
1860
1861         if (!cc_state)
1862                 return;
1863
1864         /*
1865          * 1) increase CCTI (for this SL)
1866          * 2) select IPG (i.e., call set_link_ipg())
1867          * 3) start timer
1868          */
1869         ccti_limit = cc_state->cct.ccti_limit;
1870         ccti_incr = cc_state->cong_setting.entries[sl].ccti_increase;
1871         ccti_timer = cc_state->cong_setting.entries[sl].ccti_timer;
1872         trigger_threshold =
1873                 cc_state->cong_setting.entries[sl].trigger_threshold;
1874
1875         spin_lock_irqsave(&ppd->cca_timer_lock, flags);
1876
1877         cca_timer = &ppd->cca_timer[sl];
1878         if (cca_timer->ccti < ccti_limit) {
1879                 if (cca_timer->ccti + ccti_incr <= ccti_limit)
1880                         cca_timer->ccti += ccti_incr;
1881                 else
1882                         cca_timer->ccti = ccti_limit;
1883                 set_link_ipg(ppd);
1884         }
1885
1886         ccti = cca_timer->ccti;
1887
1888         if (!hrtimer_active(&cca_timer->hrtimer)) {
1889                 /* ccti_timer is in units of 1.024 usec */
1890                 unsigned long nsec = 1024 * ccti_timer;
1891
1892                 hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec),
1893                               HRTIMER_MODE_REL);
1894         }
1895
1896         spin_unlock_irqrestore(&ppd->cca_timer_lock, flags);
1897
1898         if ((trigger_threshold != 0) && (ccti >= trigger_threshold))
1899                 log_cca_event(ppd, sl, rlid, lqpn, rqpn, svc_type);
1900 }
1901
1902 /**
1903  * hfi1_rc_rcv - process an incoming RC packet
1904  * @rcd: the context pointer
1905  * @hdr: the header of this packet
1906  * @rcv_flags: flags relevant to rcv processing
1907  * @data: the packet data
1908  * @tlen: the packet length
1909  * @qp: the QP for this packet
1910  *
1911  * This is called from qp_rcv() to process an incoming RC packet
1912  * for the given QP.
1913  * May be called at interrupt level.
1914  */
1915 void hfi1_rc_rcv(struct hfi1_packet *packet)
1916 {
1917         struct hfi1_ctxtdata *rcd = packet->rcd;
1918         struct ib_header *hdr = packet->hdr;
1919         u32 rcv_flags = packet->rcv_flags;
1920         void *data = packet->ebuf;
1921         u32 tlen = packet->tlen;
1922         struct rvt_qp *qp = packet->qp;
1923         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
1924         struct ib_other_headers *ohdr = packet->ohdr;
1925         u32 bth0, opcode;
1926         u32 hdrsize = packet->hlen;
1927         u32 psn;
1928         u32 pad;
1929         struct ib_wc wc;
1930         u32 pmtu = qp->pmtu;
1931         int diff;
1932         struct ib_reth *reth;
1933         unsigned long flags;
1934         int ret;
1935         bool is_fecn = false;
1936         bool copy_last = false;
1937         u32 rkey;
1938
1939         lockdep_assert_held(&qp->r_lock);
1940         bth0 = be32_to_cpu(ohdr->bth[0]);
1941         if (hfi1_ruc_check_hdr(ibp, hdr, rcv_flags & HFI1_HAS_GRH, qp, bth0))
1942                 return;
1943
1944         is_fecn = process_ecn(qp, packet, false);
1945
1946         psn = be32_to_cpu(ohdr->bth[2]);
1947         opcode = ib_bth_get_opcode(ohdr);
1948
1949         /*
1950          * Process responses (ACKs) before anything else.  Note that the
1951          * packet sequence number will be for something in the send work
1952          * queue rather than the expected receive packet sequence number.
1953          * In other words, this QP is the requester.
1954          */
1955         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1956             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
1957                 rc_rcv_resp(ibp, ohdr, data, tlen, qp, opcode, psn,
1958                             hdrsize, pmtu, rcd);
1959                 if (is_fecn)
1960                         goto send_ack;
1961                 return;
1962         }
1963
1964         /* Compute 24 bits worth of difference. */
1965         diff = delta_psn(psn, qp->r_psn);
1966         if (unlikely(diff)) {
1967                 if (rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd))
1968                         return;
1969                 goto send_ack;
1970         }
1971
1972         /* Check for opcode sequence errors. */
1973         switch (qp->r_state) {
1974         case OP(SEND_FIRST):
1975         case OP(SEND_MIDDLE):
1976                 if (opcode == OP(SEND_MIDDLE) ||
1977                     opcode == OP(SEND_LAST) ||
1978                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
1979                     opcode == OP(SEND_LAST_WITH_INVALIDATE))
1980                         break;
1981                 goto nack_inv;
1982
1983         case OP(RDMA_WRITE_FIRST):
1984         case OP(RDMA_WRITE_MIDDLE):
1985                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
1986                     opcode == OP(RDMA_WRITE_LAST) ||
1987                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1988                         break;
1989                 goto nack_inv;
1990
1991         default:
1992                 if (opcode == OP(SEND_MIDDLE) ||
1993                     opcode == OP(SEND_LAST) ||
1994                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
1995                     opcode == OP(SEND_LAST_WITH_INVALIDATE) ||
1996                     opcode == OP(RDMA_WRITE_MIDDLE) ||
1997                     opcode == OP(RDMA_WRITE_LAST) ||
1998                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1999                         goto nack_inv;
2000                 /*
2001                  * Note that it is up to the requester to not send a new
2002                  * RDMA read or atomic operation before receiving an ACK
2003                  * for the previous operation.
2004                  */
2005                 break;
2006         }
2007
2008         if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
2009                 rvt_comm_est(qp);
2010
2011         /* OK, process the packet. */
2012         switch (opcode) {
2013         case OP(SEND_FIRST):
2014                 ret = hfi1_rvt_get_rwqe(qp, 0);
2015                 if (ret < 0)
2016                         goto nack_op_err;
2017                 if (!ret)
2018                         goto rnr_nak;
2019                 qp->r_rcv_len = 0;
2020                 /* FALLTHROUGH */
2021         case OP(SEND_MIDDLE):
2022         case OP(RDMA_WRITE_MIDDLE):
2023 send_middle:
2024                 /* Check for invalid length PMTU or posted rwqe len. */
2025                 if (unlikely(tlen != (hdrsize + pmtu + 4)))
2026                         goto nack_inv;
2027                 qp->r_rcv_len += pmtu;
2028                 if (unlikely(qp->r_rcv_len > qp->r_len))
2029                         goto nack_inv;
2030                 hfi1_copy_sge(&qp->r_sge, data, pmtu, true, false);
2031                 break;
2032
2033         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
2034                 /* consume RWQE */
2035                 ret = hfi1_rvt_get_rwqe(qp, 1);
2036                 if (ret < 0)
2037                         goto nack_op_err;
2038                 if (!ret)
2039                         goto rnr_nak;
2040                 goto send_last_imm;
2041
2042         case OP(SEND_ONLY):
2043         case OP(SEND_ONLY_WITH_IMMEDIATE):
2044         case OP(SEND_ONLY_WITH_INVALIDATE):
2045                 ret = hfi1_rvt_get_rwqe(qp, 0);
2046                 if (ret < 0)
2047                         goto nack_op_err;
2048                 if (!ret)
2049                         goto rnr_nak;
2050                 qp->r_rcv_len = 0;
2051                 if (opcode == OP(SEND_ONLY))
2052                         goto no_immediate_data;
2053                 if (opcode == OP(SEND_ONLY_WITH_INVALIDATE))
2054                         goto send_last_inv;
2055                 /* FALLTHROUGH for SEND_ONLY_WITH_IMMEDIATE */
2056         case OP(SEND_LAST_WITH_IMMEDIATE):
2057 send_last_imm:
2058                 wc.ex.imm_data = ohdr->u.imm_data;
2059                 wc.wc_flags = IB_WC_WITH_IMM;
2060                 goto send_last;
2061         case OP(SEND_LAST_WITH_INVALIDATE):
2062 send_last_inv:
2063                 rkey = be32_to_cpu(ohdr->u.ieth);
2064                 if (rvt_invalidate_rkey(qp, rkey))
2065                         goto no_immediate_data;
2066                 wc.ex.invalidate_rkey = rkey;
2067                 wc.wc_flags = IB_WC_WITH_INVALIDATE;
2068                 goto send_last;
2069         case OP(RDMA_WRITE_LAST):
2070                 copy_last = rvt_is_user_qp(qp);
2071                 /* fall through */
2072         case OP(SEND_LAST):
2073 no_immediate_data:
2074                 wc.wc_flags = 0;
2075                 wc.ex.imm_data = 0;
2076 send_last:
2077                 /* Get the number of bytes the message was padded by. */
2078                 pad = ib_bth_get_pad(ohdr);
2079                 /* Check for invalid length. */
2080                 /* LAST len should be >= 1 */
2081                 if (unlikely(tlen < (hdrsize + pad + 4)))
2082                         goto nack_inv;
2083                 /* Don't count the CRC. */
2084                 tlen -= (hdrsize + pad + 4);
2085                 wc.byte_len = tlen + qp->r_rcv_len;
2086                 if (unlikely(wc.byte_len > qp->r_len))
2087                         goto nack_inv;
2088                 hfi1_copy_sge(&qp->r_sge, data, tlen, true, copy_last);
2089                 rvt_put_ss(&qp->r_sge);
2090                 qp->r_msn++;
2091                 if (!__test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
2092                         break;
2093                 wc.wr_id = qp->r_wr_id;
2094                 wc.status = IB_WC_SUCCESS;
2095                 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
2096                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
2097                         wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
2098                 else
2099                         wc.opcode = IB_WC_RECV;
2100                 wc.qp = &qp->ibqp;
2101                 wc.src_qp = qp->remote_qpn;
2102                 wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr);
2103                 /*
2104                  * It seems that IB mandates the presence of an SL in a
2105                  * work completion only for the UD transport (see section
2106                  * 11.4.2 of IBTA Vol. 1).
2107                  *
2108                  * However, the way the SL is chosen below is consistent
2109                  * with the way that IB/qib works and is trying avoid
2110                  * introducing incompatibilities.
2111                  *
2112                  * See also OPA Vol. 1, section 9.7.6, and table 9-17.
2113                  */
2114                 wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
2115                 /* zero fields that are N/A */
2116                 wc.vendor_err = 0;
2117                 wc.pkey_index = 0;
2118                 wc.dlid_path_bits = 0;
2119                 wc.port_num = 0;
2120                 /* Signal completion event if the solicited bit is set. */
2121                 rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
2122                              (bth0 & IB_BTH_SOLICITED) != 0);
2123                 break;
2124
2125         case OP(RDMA_WRITE_ONLY):
2126                 copy_last = rvt_is_user_qp(qp);
2127                 /* fall through */
2128         case OP(RDMA_WRITE_FIRST):
2129         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
2130                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
2131                         goto nack_inv;
2132                 /* consume RWQE */
2133                 reth = &ohdr->u.rc.reth;
2134                 qp->r_len = be32_to_cpu(reth->length);
2135                 qp->r_rcv_len = 0;
2136                 qp->r_sge.sg_list = NULL;
2137                 if (qp->r_len != 0) {
2138                         u32 rkey = be32_to_cpu(reth->rkey);
2139                         u64 vaddr = get_ib_reth_vaddr(reth);
2140                         int ok;
2141
2142                         /* Check rkey & NAK */
2143                         ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr,
2144                                          rkey, IB_ACCESS_REMOTE_WRITE);
2145                         if (unlikely(!ok))
2146                                 goto nack_acc;
2147                         qp->r_sge.num_sge = 1;
2148                 } else {
2149                         qp->r_sge.num_sge = 0;
2150                         qp->r_sge.sge.mr = NULL;
2151                         qp->r_sge.sge.vaddr = NULL;
2152                         qp->r_sge.sge.length = 0;
2153                         qp->r_sge.sge.sge_length = 0;
2154                 }
2155                 if (opcode == OP(RDMA_WRITE_FIRST))
2156                         goto send_middle;
2157                 else if (opcode == OP(RDMA_WRITE_ONLY))
2158                         goto no_immediate_data;
2159                 ret = hfi1_rvt_get_rwqe(qp, 1);
2160                 if (ret < 0)
2161                         goto nack_op_err;
2162                 if (!ret) {
2163                         /* peer will send again */
2164                         rvt_put_ss(&qp->r_sge);
2165                         goto rnr_nak;
2166                 }
2167                 wc.ex.imm_data = ohdr->u.rc.imm_data;
2168                 wc.wc_flags = IB_WC_WITH_IMM;
2169                 goto send_last;
2170
2171         case OP(RDMA_READ_REQUEST): {
2172                 struct rvt_ack_entry *e;
2173                 u32 len;
2174                 u8 next;
2175
2176                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
2177                         goto nack_inv;
2178                 next = qp->r_head_ack_queue + 1;
2179                 /* s_ack_queue is size HFI1_MAX_RDMA_ATOMIC+1 so use > not >= */
2180                 if (next > HFI1_MAX_RDMA_ATOMIC)
2181                         next = 0;
2182                 spin_lock_irqsave(&qp->s_lock, flags);
2183                 if (unlikely(next == qp->s_tail_ack_queue)) {
2184                         if (!qp->s_ack_queue[next].sent)
2185                                 goto nack_inv_unlck;
2186                         update_ack_queue(qp, next);
2187                 }
2188                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
2189                 if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
2190                         rvt_put_mr(e->rdma_sge.mr);
2191                         e->rdma_sge.mr = NULL;
2192                 }
2193                 reth = &ohdr->u.rc.reth;
2194                 len = be32_to_cpu(reth->length);
2195                 if (len) {
2196                         u32 rkey = be32_to_cpu(reth->rkey);
2197                         u64 vaddr = get_ib_reth_vaddr(reth);
2198                         int ok;
2199
2200                         /* Check rkey & NAK */
2201                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr,
2202                                          rkey, IB_ACCESS_REMOTE_READ);
2203                         if (unlikely(!ok))
2204                                 goto nack_acc_unlck;
2205                         /*
2206                          * Update the next expected PSN.  We add 1 later
2207                          * below, so only add the remainder here.
2208                          */
2209                         qp->r_psn += rvt_div_mtu(qp, len - 1);
2210                 } else {
2211                         e->rdma_sge.mr = NULL;
2212                         e->rdma_sge.vaddr = NULL;
2213                         e->rdma_sge.length = 0;
2214                         e->rdma_sge.sge_length = 0;
2215                 }
2216                 e->opcode = opcode;
2217                 e->sent = 0;
2218                 e->psn = psn;
2219                 e->lpsn = qp->r_psn;
2220                 /*
2221                  * We need to increment the MSN here instead of when we
2222                  * finish sending the result since a duplicate request would
2223                  * increment it more than once.
2224                  */
2225                 qp->r_msn++;
2226                 qp->r_psn++;
2227                 qp->r_state = opcode;
2228                 qp->r_nak_state = 0;
2229                 qp->r_head_ack_queue = next;
2230
2231                 /* Schedule the send engine. */
2232                 qp->s_flags |= RVT_S_RESP_PENDING;
2233                 hfi1_schedule_send(qp);
2234
2235                 spin_unlock_irqrestore(&qp->s_lock, flags);
2236                 if (is_fecn)
2237                         goto send_ack;
2238                 return;
2239         }
2240
2241         case OP(COMPARE_SWAP):
2242         case OP(FETCH_ADD): {
2243                 struct ib_atomic_eth *ateth;
2244                 struct rvt_ack_entry *e;
2245                 u64 vaddr;
2246                 atomic64_t *maddr;
2247                 u64 sdata;
2248                 u32 rkey;
2249                 u8 next;
2250
2251                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
2252                         goto nack_inv;
2253                 next = qp->r_head_ack_queue + 1;
2254                 if (next > HFI1_MAX_RDMA_ATOMIC)
2255                         next = 0;
2256                 spin_lock_irqsave(&qp->s_lock, flags);
2257                 if (unlikely(next == qp->s_tail_ack_queue)) {
2258                         if (!qp->s_ack_queue[next].sent)
2259                                 goto nack_inv_unlck;
2260                         update_ack_queue(qp, next);
2261                 }
2262                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
2263                 if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
2264                         rvt_put_mr(e->rdma_sge.mr);
2265                         e->rdma_sge.mr = NULL;
2266                 }
2267                 ateth = &ohdr->u.atomic_eth;
2268                 vaddr = get_ib_ateth_vaddr(ateth);
2269                 if (unlikely(vaddr & (sizeof(u64) - 1)))
2270                         goto nack_inv_unlck;
2271                 rkey = be32_to_cpu(ateth->rkey);
2272                 /* Check rkey & NAK */
2273                 if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
2274                                           vaddr, rkey,
2275                                           IB_ACCESS_REMOTE_ATOMIC)))
2276                         goto nack_acc_unlck;
2277                 /* Perform atomic OP and save result. */
2278                 maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
2279                 sdata = get_ib_ateth_swap(ateth);
2280                 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
2281                         (u64)atomic64_add_return(sdata, maddr) - sdata :
2282                         (u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
2283                                       get_ib_ateth_compare(ateth),
2284                                       sdata);
2285                 rvt_put_mr(qp->r_sge.sge.mr);
2286                 qp->r_sge.num_sge = 0;
2287                 e->opcode = opcode;
2288                 e->sent = 0;
2289                 e->psn = psn;
2290                 e->lpsn = psn;
2291                 qp->r_msn++;
2292                 qp->r_psn++;
2293                 qp->r_state = opcode;
2294                 qp->r_nak_state = 0;
2295                 qp->r_head_ack_queue = next;
2296
2297                 /* Schedule the send engine. */
2298                 qp->s_flags |= RVT_S_RESP_PENDING;
2299                 hfi1_schedule_send(qp);
2300
2301                 spin_unlock_irqrestore(&qp->s_lock, flags);
2302                 if (is_fecn)
2303                         goto send_ack;
2304                 return;
2305         }
2306
2307         default:
2308                 /* NAK unknown opcodes. */
2309                 goto nack_inv;
2310         }
2311         qp->r_psn++;
2312         qp->r_state = opcode;
2313         qp->r_ack_psn = psn;
2314         qp->r_nak_state = 0;
2315         /* Send an ACK if requested or required. */
2316         if (psn & IB_BTH_REQ_ACK) {
2317                 if (packet->numpkt == 0) {
2318                         rc_cancel_ack(qp);
2319                         goto send_ack;
2320                 }
2321                 if (qp->r_adefered >= HFI1_PSN_CREDIT) {
2322                         rc_cancel_ack(qp);
2323                         goto send_ack;
2324                 }
2325                 if (unlikely(is_fecn)) {
2326                         rc_cancel_ack(qp);
2327                         goto send_ack;
2328                 }
2329                 qp->r_adefered++;
2330                 rc_defered_ack(rcd, qp);
2331         }
2332         return;
2333
2334 rnr_nak:
2335         qp->r_nak_state = qp->r_min_rnr_timer | IB_RNR_NAK;
2336         qp->r_ack_psn = qp->r_psn;
2337         /* Queue RNR NAK for later */
2338         rc_defered_ack(rcd, qp);
2339         return;
2340
2341 nack_op_err:
2342         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
2343         qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
2344         qp->r_ack_psn = qp->r_psn;
2345         /* Queue NAK for later */
2346         rc_defered_ack(rcd, qp);
2347         return;
2348
2349 nack_inv_unlck:
2350         spin_unlock_irqrestore(&qp->s_lock, flags);
2351 nack_inv:
2352         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
2353         qp->r_nak_state = IB_NAK_INVALID_REQUEST;
2354         qp->r_ack_psn = qp->r_psn;
2355         /* Queue NAK for later */
2356         rc_defered_ack(rcd, qp);
2357         return;
2358
2359 nack_acc_unlck:
2360         spin_unlock_irqrestore(&qp->s_lock, flags);
2361 nack_acc:
2362         rvt_rc_error(qp, IB_WC_LOC_PROT_ERR);
2363         qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
2364         qp->r_ack_psn = qp->r_psn;
2365 send_ack:
2366         hfi1_send_rc_ack(rcd, qp, is_fecn);
2367 }
2368
2369 void hfi1_rc_hdrerr(
2370         struct hfi1_ctxtdata *rcd,
2371         struct ib_header *hdr,
2372         u32 rcv_flags,
2373         struct rvt_qp *qp)
2374 {
2375         int has_grh = rcv_flags & HFI1_HAS_GRH;
2376         struct ib_other_headers *ohdr;
2377         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2378         int diff;
2379         u32 opcode;
2380         u32 psn, bth0;
2381
2382         /* Check for GRH */
2383         ohdr = &hdr->u.oth;
2384         if (has_grh)
2385                 ohdr = &hdr->u.l.oth;
2386
2387         bth0 = be32_to_cpu(ohdr->bth[0]);
2388         if (hfi1_ruc_check_hdr(ibp, hdr, has_grh, qp, bth0))
2389                 return;
2390
2391         psn = be32_to_cpu(ohdr->bth[2]);
2392         opcode = ib_bth_get_opcode(ohdr);
2393
2394         /* Only deal with RDMA Writes for now */
2395         if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {
2396                 diff = delta_psn(psn, qp->r_psn);
2397                 if (!qp->r_nak_state && diff >= 0) {
2398                         ibp->rvp.n_rc_seqnak++;
2399                         qp->r_nak_state = IB_NAK_PSN_ERROR;
2400                         /* Use the expected PSN. */
2401                         qp->r_ack_psn = qp->r_psn;
2402                         /*
2403                          * Wait to send the sequence
2404                          * NAK until all packets
2405                          * in the receive queue have
2406                          * been processed.
2407                          * Otherwise, we end up
2408                          * propagating congestion.
2409                          */
2410                         rc_defered_ack(rcd, qp);
2411                 } /* Out of sequence NAK */
2412         } /* QP Request NAKs */
2413 }