drivers/infiniband/hw/hfi1/rc.c

   1 /*
   2  * Copyright(c) 2015 - 2018 Intel Corporation.
   3  *
   4  * This file is provided under a dual BSD/GPLv2 license.  When using or
   5  * redistributing this file, you may do so under either license.
   6  *
   7  * GPL LICENSE SUMMARY
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * BSD LICENSE
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  *
  24  *  - Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  *  - Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in
  28  *    the documentation and/or other materials provided with the
  29  *    distribution.
  30  *  - Neither the name of Intel Corporation nor the names of its
  31  *    contributors may be used to endorse or promote products derived
  32  *    from this software without specific prior written permission.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45  *
  46  */
  47
  48 #include <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 "rc.h"
  55 #include "verbs_txreq.h"
  56 #include "trace.h"
  57
  58 struct rvt_ack_entry *find_prev_entry(struct rvt_qp *qp, u32 psn, u8 *prev,
  59                                       u8 *prev_ack, bool *scheduled)
  60         __must_hold(&qp->s_lock)
  61 {
  62         struct rvt_ack_entry *e = NULL;
  63         u8 i, p;
  64         bool s = true;
  65
  66         for (i = qp->r_head_ack_queue; ; i = p) {
  67                 if (i == qp->s_tail_ack_queue)
  68                         s = false;
  69                 if (i)
  70                         p = i - 1;
  71                 else
  72                         p = rvt_size_atomic(ib_to_rvt(qp->ibqp.device));
  73                 if (p == qp->r_head_ack_queue) {
  74                         e = NULL;
  75                         break;
  76                 }
  77                 e = &qp->s_ack_queue[p];
  78                 if (!e->opcode) {
  79                         e = NULL;
  80                         break;
  81                 }
  82                 if (cmp_psn(psn, e->psn) >= 0) {
  83                         if (p == qp->s_tail_ack_queue &&
  84                             cmp_psn(psn, e->lpsn) <= 0)
  85                                 s = false;
  86                         break;
  87                 }
  88         }
  89         if (prev)
  90                 *prev = p;
  91         if (prev_ack)
  92                 *prev_ack = i;
  93         if (scheduled)
  94                 *scheduled = s;
  95         return e;
  96 }
  97
  98 /**
  99  * make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
 100  * @dev: the device for this QP
 101  * @qp: a pointer to the QP
 102  * @ohdr: a pointer to the IB header being constructed
 103  * @ps: the xmit packet state
 104  *
 105  * Return 1 if constructed; otherwise, return 0.
 106  * Note that we are in the responder's side of the QP context.
 107  * Note the QP s_lock must be held.
 108  */
 109 static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp,
 110                        struct ib_other_headers *ohdr,
 111                        struct hfi1_pkt_state *ps)
 112 {
 113         struct rvt_ack_entry *e;
 114         u32 hwords, hdrlen;
 115         u32 len = 0;
 116         u32 bth0 = 0, bth2 = 0;
 117         u32 bth1 = qp->remote_qpn | (HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT);
 118         int middle = 0;
 119         u32 pmtu = qp->pmtu;
 120         struct hfi1_qp_priv *qpriv = qp->priv;
 121         bool last_pkt;
 122         u32 delta;
 123         u8 next = qp->s_tail_ack_queue;
 124         struct tid_rdma_request *req;
 125
 126         trace_hfi1_rsp_make_rc_ack(qp, 0);
 127         lockdep_assert_held(&qp->s_lock);
 128         /* Don't send an ACK if we aren't supposed to. */
 129         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
 130                 goto bail;
 131
 132         if (qpriv->hdr_type == HFI1_PKT_TYPE_9B)
 133                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
 134                 hwords = 5;
 135         else
 136                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
 137                 hwords = 7;
 138
 139         switch (qp->s_ack_state) {
 140         case OP(RDMA_READ_RESPONSE_LAST):
 141         case OP(RDMA_READ_RESPONSE_ONLY):
 142                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 143                 if (e->rdma_sge.mr) {
 144                         rvt_put_mr(e->rdma_sge.mr);
 145                         e->rdma_sge.mr = NULL;
 146                 }
 147                 /* FALLTHROUGH */
 148         case OP(ATOMIC_ACKNOWLEDGE):
 149                 /*
 150                  * We can increment the tail pointer now that the last
 151                  * response has been sent instead of only being
 152                  * constructed.
 153                  */
 154                 if (++next > rvt_size_atomic(&dev->rdi))
 155                         next = 0;
 156                 /*
 157                  * Only advance the s_acked_ack_queue pointer if there
 158                  * have been no TID RDMA requests.
 159                  */
 160                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 161                 if (e->opcode != TID_OP(WRITE_REQ) &&
 162                     qp->s_acked_ack_queue == qp->s_tail_ack_queue)
 163                         qp->s_acked_ack_queue = next;
 164                 qp->s_tail_ack_queue = next;
 165                 trace_hfi1_rsp_make_rc_ack(qp, e->psn);
 166                 /* FALLTHROUGH */
 167         case OP(SEND_ONLY):
 168         case OP(ACKNOWLEDGE):
 169                 /* Check for no next entry in the queue. */
 170                 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
 171                         if (qp->s_flags & RVT_S_ACK_PENDING)
 172                                 goto normal;
 173                         goto bail;
 174                 }
 175
 176                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 177                 /* Check for tid write fence */
 178                 if ((qpriv->s_flags & HFI1_R_TID_WAIT_INTERLCK) ||
 179                     hfi1_tid_rdma_ack_interlock(qp, e)) {
 180                         iowait_set_flag(&qpriv->s_iowait, IOWAIT_PENDING_IB);
 181                         goto bail;
 182                 }
 183                 if (e->opcode == OP(RDMA_READ_REQUEST)) {
 184                         /*
 185                          * If a RDMA read response is being resent and
 186                          * we haven't seen the duplicate request yet,
 187                          * then stop sending the remaining responses the
 188                          * responder has seen until the requester re-sends it.
 189                          */
 190                         len = e->rdma_sge.sge_length;
 191                         if (len && !e->rdma_sge.mr) {
 192                                 if (qp->s_acked_ack_queue ==
 193                                     qp->s_tail_ack_queue)
 194                                         qp->s_acked_ack_queue =
 195                                                 qp->r_head_ack_queue;
 196                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
 197                                 goto bail;
 198                         }
 199                         /* Copy SGE state in case we need to resend */
 200                         ps->s_txreq->mr = e->rdma_sge.mr;
 201                         if (ps->s_txreq->mr)
 202                                 rvt_get_mr(ps->s_txreq->mr);
 203                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
 204                         qp->s_ack_rdma_sge.num_sge = 1;
 205                         ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 206                         if (len > pmtu) {
 207                                 len = pmtu;
 208                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
 209                         } else {
 210                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
 211                                 e->sent = 1;
 212                         }
 213                         ohdr->u.aeth = rvt_compute_aeth(qp);
 214                         hwords++;
 215                         qp->s_ack_rdma_psn = e->psn;
 216                         bth2 = mask_psn(qp->s_ack_rdma_psn++);
 217                 } else if (e->opcode == TID_OP(WRITE_REQ)) {
 218                         /*
 219                          * If a TID RDMA WRITE RESP is being resent, we have to
 220                          * wait for the actual request. All requests that are to
 221                          * be resent will have their state set to
 222                          * TID_REQUEST_RESEND. When the new request arrives, the
 223                          * state will be changed to TID_REQUEST_RESEND_ACTIVE.
 224                          */
 225                         req = ack_to_tid_req(e);
 226                         if (req->state == TID_REQUEST_RESEND ||
 227                             req->state == TID_REQUEST_INIT_RESEND)
 228                                 goto bail;
 229                         qp->s_ack_state = TID_OP(WRITE_RESP);
 230                         qp->s_ack_rdma_psn = mask_psn(e->psn + req->cur_seg);
 231                         goto write_resp;
 232                 } else if (e->opcode == TID_OP(READ_REQ)) {
 233                         /*
 234                          * If a TID RDMA read response is being resent and
 235                          * we haven't seen the duplicate request yet,
 236                          * then stop sending the remaining responses the
 237                          * responder has seen until the requester re-sends it.
 238                          */
 239                         len = e->rdma_sge.sge_length;
 240                         if (len && !e->rdma_sge.mr) {
 241                                 if (qp->s_acked_ack_queue ==
 242                                     qp->s_tail_ack_queue)
 243                                         qp->s_acked_ack_queue =
 244                                                 qp->r_head_ack_queue;
 245                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
 246                                 goto bail;
 247                         }
 248                         /* Copy SGE state in case we need to resend */
 249                         ps->s_txreq->mr = e->rdma_sge.mr;
 250                         if (ps->s_txreq->mr)
 251                                 rvt_get_mr(ps->s_txreq->mr);
 252                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
 253                         qp->s_ack_rdma_sge.num_sge = 1;
 254                         qp->s_ack_state = TID_OP(READ_RESP);
 255                         goto read_resp;
 256                 } else {
 257                         /* COMPARE_SWAP or FETCH_ADD */
 258                         ps->s_txreq->ss = NULL;
 259                         len = 0;
 260                         qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
 261                         ohdr->u.at.aeth = rvt_compute_aeth(qp);
 262                         ib_u64_put(e->atomic_data, &ohdr->u.at.atomic_ack_eth);
 263                         hwords += sizeof(ohdr->u.at) / sizeof(u32);
 264                         bth2 = mask_psn(e->psn);
 265                         e->sent = 1;
 266                 }
 267                 trace_hfi1_tid_write_rsp_make_rc_ack(qp);
 268                 bth0 = qp->s_ack_state << 24;
 269                 break;
 270
 271         case OP(RDMA_READ_RESPONSE_FIRST):
 272                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
 273                 /* FALLTHROUGH */
 274         case OP(RDMA_READ_RESPONSE_MIDDLE):
 275                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 276                 ps->s_txreq->mr = qp->s_ack_rdma_sge.sge.mr;
 277                 if (ps->s_txreq->mr)
 278                         rvt_get_mr(ps->s_txreq->mr);
 279                 len = qp->s_ack_rdma_sge.sge.sge_length;
 280                 if (len > pmtu) {
 281                         len = pmtu;
 282                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 283                 } else {
 284                         ohdr->u.aeth = rvt_compute_aeth(qp);
 285                         hwords++;
 286                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
 287                         e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 288                         e->sent = 1;
 289                 }
 290                 bth0 = qp->s_ack_state << 24;
 291                 bth2 = mask_psn(qp->s_ack_rdma_psn++);
 292                 break;
 293
 294         case TID_OP(WRITE_RESP):
 295 write_resp:
 296                 /*
 297                  * 1. Check if RVT_S_ACK_PENDING is set. If yes,
 298                  *    goto normal.
 299                  * 2. Attempt to allocate TID resources.
 300                  * 3. Remove RVT_S_RESP_PENDING flags from s_flags
 301                  * 4. If resources not available:
 302                  *    4.1 Set RVT_S_WAIT_TID_SPACE
 303                  *    4.2 Queue QP on RCD TID queue
 304                  *    4.3 Put QP on iowait list.
 305                  *    4.4 Build IB RNR NAK with appropriate timeout value
 306                  *    4.5 Return indication progress made.
 307                  * 5. If resources are available:
 308                  *    5.1 Program HW flow CSRs
 309                  *    5.2 Build TID RDMA WRITE RESP packet
 310                  *    5.3 If more resources needed, do 2.1 - 2.3.
 311                  *    5.4 Wake up next QP on RCD TID queue.
 312                  *    5.5 Return indication progress made.
 313                  */
 314
 315                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 316                 req = ack_to_tid_req(e);
 317
 318                 /*
 319                  * Send scheduled RNR NAK's. RNR NAK's need to be sent at
 320                  * segment boundaries, not at request boundaries. Don't change
 321                  * s_ack_state because we are still in the middle of a request
 322                  */
 323                 if (qpriv->rnr_nak_state == TID_RNR_NAK_SEND &&
 324                     qp->s_tail_ack_queue == qpriv->r_tid_alloc &&
 325                     req->cur_seg == req->alloc_seg) {
 326                         qpriv->rnr_nak_state = TID_RNR_NAK_SENT;
 327                         goto normal_no_state;
 328                 }
 329
 330                 bth2 = mask_psn(qp->s_ack_rdma_psn);
 331                 hdrlen = hfi1_build_tid_rdma_write_resp(qp, e, ohdr, &bth1,
 332                                                         bth2, &len,
 333                                                         &ps->s_txreq->ss);
 334                 if (!hdrlen)
 335                         return 0;
 336
 337                 hwords += hdrlen;
 338                 bth0 = qp->s_ack_state << 24;
 339                 qp->s_ack_rdma_psn++;
 340                 trace_hfi1_tid_req_make_rc_ack_write(qp, 0, e->opcode, e->psn,
 341                                                      e->lpsn, req);
 342                 if (req->cur_seg != req->total_segs)
 343                         break;
 344
 345                 e->sent = 1;
 346                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
 347                 break;
 348
 349         case TID_OP(READ_RESP):
 350 read_resp:
 351                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 352                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 353                 delta = hfi1_build_tid_rdma_read_resp(qp, e, ohdr, &bth0,
 354                                                       &bth1, &bth2, &len,
 355                                                       &last_pkt);
 356                 if (delta == 0)
 357                         goto error_qp;
 358                 hwords += delta;
 359                 if (last_pkt) {
 360                         e->sent = 1;
 361                         /*
 362                          * Increment qp->s_tail_ack_queue through s_ack_state
 363                          * transition.
 364                          */
 365                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
 366                 }
 367                 break;
 368         case TID_OP(READ_REQ):
 369                 goto bail;
 370
 371         default:
 372 normal:
 373                 /*
 374                  * Send a regular ACK.
 375                  * Set the s_ack_state so we wait until after sending
 376                  * the ACK before setting s_ack_state to ACKNOWLEDGE
 377                  * (see above).
 378                  */
 379                 qp->s_ack_state = OP(SEND_ONLY);
 380 normal_no_state:
 381                 if (qp->s_nak_state)
 382                         ohdr->u.aeth =
 383                                 cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
 384                                             (qp->s_nak_state <<
 385                                              IB_AETH_CREDIT_SHIFT));
 386                 else
 387                         ohdr->u.aeth = rvt_compute_aeth(qp);
 388                 hwords++;
 389                 len = 0;
 390                 bth0 = OP(ACKNOWLEDGE) << 24;
 391                 bth2 = mask_psn(qp->s_ack_psn);
 392                 qp->s_flags &= ~RVT_S_ACK_PENDING;
 393                 ps->s_txreq->txreq.flags |= SDMA_TXREQ_F_VIP;
 394                 ps->s_txreq->ss = NULL;
 395         }
 396         qp->s_rdma_ack_cnt++;
 397         ps->s_txreq->sde = qpriv->s_sde;
 398         ps->s_txreq->s_cur_size = len;
 399         ps->s_txreq->hdr_dwords = hwords;
 400         hfi1_make_ruc_header(qp, ohdr, bth0, bth1, bth2, middle, ps);
 401         return 1;
 402 error_qp:
 403         spin_unlock_irqrestore(&qp->s_lock, ps->flags);
 404         spin_lock_irqsave(&qp->r_lock, ps->flags);
 405         spin_lock(&qp->s_lock);
 406         rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
 407         spin_unlock(&qp->s_lock);
 408         spin_unlock_irqrestore(&qp->r_lock, ps->flags);
 409         spin_lock_irqsave(&qp->s_lock, ps->flags);
 410 bail:
 411         qp->s_ack_state = OP(ACKNOWLEDGE);
 412         /*
 413          * Ensure s_rdma_ack_cnt changes are committed prior to resetting
 414          * RVT_S_RESP_PENDING
 415          */
 416         smp_wmb();
 417         qp->s_flags &= ~(RVT_S_RESP_PENDING
 418                                 | RVT_S_ACK_PENDING
 419                                 | HFI1_S_AHG_VALID);
 420         return 0;
 421 }
 422
 423 /**
 424  * hfi1_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
 425  * @qp: a pointer to the QP
 426  *
 427  * Assumes s_lock is held.
 428  *
 429  * Return 1 if constructed; otherwise, return 0.
 430  */
 431 int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
 432 {
 433         struct hfi1_qp_priv *priv = qp->priv;
 434         struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
 435         struct ib_other_headers *ohdr;
 436         struct rvt_sge_state *ss = NULL;
 437         struct rvt_swqe *wqe;
 438         struct hfi1_swqe_priv *wpriv;
 439         struct tid_rdma_request *req = NULL;
 440         /* header size in 32-bit words LRH+BTH = (8+12)/4. */
 441         u32 hwords = 5;
 442         u32 len = 0;
 443         u32 bth0 = 0, bth2 = 0;
 444         u32 bth1 = qp->remote_qpn | (HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT);
 445         u32 pmtu = qp->pmtu;
 446         char newreq;
 447         int middle = 0;
 448         int delta;
 449         struct tid_rdma_flow *flow = NULL;
 450         struct tid_rdma_params *remote;
 451
 452         trace_hfi1_sender_make_rc_req(qp);
 453         lockdep_assert_held(&qp->s_lock);
 454         ps->s_txreq = get_txreq(ps->dev, qp);
 455         if (!ps->s_txreq)
 456                 goto bail_no_tx;
 457
 458         if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
 459                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
 460                 hwords = 5;
 461                 if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
 462                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
 463                 else
 464                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
 465         } else {
 466                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
 467                 hwords = 7;
 468                 if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
 469                     (hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))))
 470                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
 471                 else
 472                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
 473         }
 474
 475         /* Sending responses has higher priority over sending requests. */
 476         if ((qp->s_flags & RVT_S_RESP_PENDING) &&
 477             make_rc_ack(dev, qp, ohdr, ps))
 478                 return 1;
 479
 480         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
 481                 if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
 482                         goto bail;
 483                 /* We are in the error state, flush the work request. */
 484                 if (qp->s_last == READ_ONCE(qp->s_head))
 485                         goto bail;
 486                 /* If DMAs are in progress, we can't flush immediately. */
 487                 if (iowait_sdma_pending(&priv->s_iowait)) {
 488                         qp->s_flags |= RVT_S_WAIT_DMA;
 489                         goto bail;
 490                 }
 491                 clear_ahg(qp);
 492                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
 493                 hfi1_trdma_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
 494                                          IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
 495                 /* will get called again */
 496                 goto done_free_tx;
 497         }
 498
 499         if (qp->s_flags & (RVT_S_WAIT_RNR | RVT_S_WAIT_ACK | HFI1_S_WAIT_HALT))
 500                 goto bail;
 501
 502         if (cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) {
 503                 if (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) {
 504                         qp->s_flags |= RVT_S_WAIT_PSN;
 505                         goto bail;
 506                 }
 507                 qp->s_sending_psn = qp->s_psn;
 508                 qp->s_sending_hpsn = qp->s_psn - 1;
 509         }
 510
 511         /* Send a request. */
 512         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
 513 check_s_state:
 514         switch (qp->s_state) {
 515         default:
 516                 if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK))
 517                         goto bail;
 518                 /*
 519                  * Resend an old request or start a new one.
 520                  *
 521                  * We keep track of the current SWQE so that
 522                  * we don't reset the "furthest progress" state
 523                  * if we need to back up.
 524                  */
 525                 newreq = 0;
 526                 if (qp->s_cur == qp->s_tail) {
 527                         /* Check if send work queue is empty. */
 528                         if (qp->s_tail == READ_ONCE(qp->s_head)) {
 529                                 clear_ahg(qp);
 530                                 goto bail;
 531                         }
 532                         /*
 533                          * If a fence is requested, wait for previous
 534                          * RDMA read and atomic operations to finish.
 535                          * However, there is no need to guard against
 536                          * TID RDMA READ after TID RDMA READ.
 537                          */
 538                         if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
 539                             qp->s_num_rd_atomic &&
 540                             (wqe->wr.opcode != IB_WR_TID_RDMA_READ ||
 541                              priv->pending_tid_r_segs < qp->s_num_rd_atomic)) {
 542                                 qp->s_flags |= RVT_S_WAIT_FENCE;
 543                                 goto bail;
 544                         }
 545                         /*
 546                          * Local operations are processed immediately
 547                          * after all prior requests have completed
 548                          */
 549                         if (wqe->wr.opcode == IB_WR_REG_MR ||
 550                             wqe->wr.opcode == IB_WR_LOCAL_INV) {
 551                                 int local_ops = 0;
 552                                 int err = 0;
 553
 554                                 if (qp->s_last != qp->s_cur)
 555                                         goto bail;
 556                                 if (++qp->s_cur == qp->s_size)
 557                                         qp->s_cur = 0;
 558                                 if (++qp->s_tail == qp->s_size)
 559                                         qp->s_tail = 0;
 560                                 if (!(wqe->wr.send_flags &
 561                                       RVT_SEND_COMPLETION_ONLY)) {
 562                                         err = rvt_invalidate_rkey(
 563                                                 qp,
 564                                                 wqe->wr.ex.invalidate_rkey);
 565                                         local_ops = 1;
 566                                 }
 567                                 rvt_send_complete(qp, wqe,
 568                                                   err ? IB_WC_LOC_PROT_ERR
 569                                                       : IB_WC_SUCCESS);
 570                                 if (local_ops)
 571                                         atomic_dec(&qp->local_ops_pending);
 572                                 goto done_free_tx;
 573                         }
 574
 575                         newreq = 1;
 576                         qp->s_psn = wqe->psn;
 577                 }
 578                 /*
 579                  * Note that we have to be careful not to modify the
 580                  * original work request since we may need to resend
 581                  * it.
 582                  */
 583                 len = wqe->length;
 584                 ss = &qp->s_sge;
 585                 bth2 = mask_psn(qp->s_psn);
 586
 587                 /*
 588                  * Interlock between various IB requests and TID RDMA
 589                  * if necessary.
 590                  */
 591                 if ((priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) ||
 592                     hfi1_tid_rdma_wqe_interlock(qp, wqe))
 593                         goto bail;
 594
 595                 switch (wqe->wr.opcode) {
 596                 case IB_WR_SEND:
 597                 case IB_WR_SEND_WITH_IMM:
 598                 case IB_WR_SEND_WITH_INV:
 599                         /* If no credit, return. */
 600                         if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
 601                             rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
 602                                 qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
 603                                 goto bail;
 604                         }
 605                         if (len > pmtu) {
 606                                 qp->s_state = OP(SEND_FIRST);
 607                                 len = pmtu;
 608                                 break;
 609                         }
 610                         if (wqe->wr.opcode == IB_WR_SEND) {
 611                                 qp->s_state = OP(SEND_ONLY);
 612                         } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 613                                 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
 614                                 /* Immediate data comes after the BTH */
 615                                 ohdr->u.imm_data = wqe->wr.ex.imm_data;
 616                                 hwords += 1;
 617                         } else {
 618                                 qp->s_state = OP(SEND_ONLY_WITH_INVALIDATE);
 619                                 /* Invalidate rkey comes after the BTH */
 620                                 ohdr->u.ieth = cpu_to_be32(
 621                                                 wqe->wr.ex.invalidate_rkey);
 622                                 hwords += 1;
 623                         }
 624                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 625                                 bth0 |= IB_BTH_SOLICITED;
 626                         bth2 |= IB_BTH_REQ_ACK;
 627                         if (++qp->s_cur == qp->s_size)
 628                                 qp->s_cur = 0;
 629                         break;
 630
 631                 case IB_WR_RDMA_WRITE:
 632                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 633                                 qp->s_lsn++;
 634                         goto no_flow_control;
 635                 case IB_WR_RDMA_WRITE_WITH_IMM:
 636                         /* If no credit, return. */
 637                         if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
 638                             rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
 639                                 qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
 640                                 goto bail;
 641                         }
 642 no_flow_control:
 643                         put_ib_reth_vaddr(
 644                                 wqe->rdma_wr.remote_addr,
 645                                 &ohdr->u.rc.reth);
 646                         ohdr->u.rc.reth.rkey =
 647                                 cpu_to_be32(wqe->rdma_wr.rkey);
 648                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 649                         hwords += sizeof(struct ib_reth) / sizeof(u32);
 650                         if (len > pmtu) {
 651                                 qp->s_state = OP(RDMA_WRITE_FIRST);
 652                                 len = pmtu;
 653                                 break;
 654                         }
 655                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 656                                 qp->s_state = OP(RDMA_WRITE_ONLY);
 657                         } else {
 658                                 qp->s_state =
 659                                         OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
 660                                 /* Immediate data comes after RETH */
 661                                 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
 662                                 hwords += 1;
 663                                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 664                                         bth0 |= IB_BTH_SOLICITED;
 665                         }
 666                         bth2 |= IB_BTH_REQ_ACK;
 667                         if (++qp->s_cur == qp->s_size)
 668                                 qp->s_cur = 0;
 669                         break;
 670
 671                 case IB_WR_TID_RDMA_WRITE:
 672                         if (newreq) {
 673                                 /*
 674                                  * Limit the number of TID RDMA WRITE requests.
 675                                  */
 676                                 if (atomic_read(&priv->n_tid_requests) >=
 677                                     HFI1_TID_RDMA_WRITE_CNT)
 678                                         goto bail;
 679
 680                                 if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 681                                         qp->s_lsn++;
 682                         }
 683
 684                         hwords += hfi1_build_tid_rdma_write_req(qp, wqe, ohdr,
 685                                                                 &bth1, &bth2,
 686                                                                 &len);
 687                         ss = NULL;
 688                         if (priv->s_tid_cur == HFI1_QP_WQE_INVALID) {
 689                                 priv->s_tid_cur = qp->s_cur;
 690                                 if (priv->s_tid_tail == HFI1_QP_WQE_INVALID) {
 691                                         priv->s_tid_tail = qp->s_cur;
 692                                         priv->s_state = TID_OP(WRITE_RESP);
 693                                 }
 694                         } else if (priv->s_tid_cur == priv->s_tid_head) {
 695                                 struct rvt_swqe *__w;
 696                                 struct tid_rdma_request *__r;
 697
 698                                 __w = rvt_get_swqe_ptr(qp, priv->s_tid_cur);
 699                                 __r = wqe_to_tid_req(__w);
 700
 701                                 /*
 702                                  * The s_tid_cur pointer is advanced to s_cur if
 703                                  * any of the following conditions about the WQE
 704                                  * to which s_ti_cur currently points to are
 705                                  * satisfied:
 706                                  *   1. The request is not a TID RDMA WRITE
 707                                  *      request,
 708                                  *   2. The request is in the INACTIVE or
 709                                  *      COMPLETE states (TID RDMA READ requests
 710                                  *      stay at INACTIVE and TID RDMA WRITE
 711                                  *      transition to COMPLETE when done),
 712                                  *   3. The request is in the ACTIVE or SYNC
 713                                  *      state and the number of completed
 714                                  *      segments is equal to the total segment
 715                                  *      count.
 716                                  *      (If ACTIVE, the request is waiting for
 717                                  *       ACKs. If SYNC, the request has not
 718                                  *       received any responses because it's
 719                                  *       waiting on a sync point.)
 720                                  */
 721                                 if (__w->wr.opcode != IB_WR_TID_RDMA_WRITE ||
 722                                     __r->state == TID_REQUEST_INACTIVE ||
 723                                     __r->state == TID_REQUEST_COMPLETE ||
 724                                     ((__r->state == TID_REQUEST_ACTIVE ||
 725                                       __r->state == TID_REQUEST_SYNC) &&
 726                                      __r->comp_seg == __r->total_segs)) {
 727                                         if (priv->s_tid_tail ==
 728                                             priv->s_tid_cur &&
 729                                             priv->s_state ==
 730                                             TID_OP(WRITE_DATA_LAST)) {
 731                                                 priv->s_tid_tail = qp->s_cur;
 732                                                 priv->s_state =
 733                                                         TID_OP(WRITE_RESP);
 734                                         }
 735                                         priv->s_tid_cur = qp->s_cur;
 736                                 }
 737                                 /*
 738                                  * A corner case: when the last TID RDMA WRITE
 739                                  * request was completed, s_tid_head,
 740                                  * s_tid_cur, and s_tid_tail all point to the
 741                                  * same location. Other requests are posted and
 742                                  * s_cur wraps around to the same location,
 743                                  * where a new TID RDMA WRITE is posted. In
 744                                  * this case, none of the indices need to be
 745                                  * updated. However, the priv->s_state should.
 746                                  */
 747                                 if (priv->s_tid_tail == qp->s_cur &&
 748                                     priv->s_state == TID_OP(WRITE_DATA_LAST))
 749                                         priv->s_state = TID_OP(WRITE_RESP);
 750                         }
 751                         req = wqe_to_tid_req(wqe);
 752                         if (newreq) {
 753                                 priv->s_tid_head = qp->s_cur;
 754                                 priv->pending_tid_w_resp += req->total_segs;
 755                                 atomic_inc(&priv->n_tid_requests);
 756                                 atomic_dec(&priv->n_requests);
 757                         } else {
 758                                 req->state = TID_REQUEST_RESEND;
 759                                 req->comp_seg = delta_psn(bth2, wqe->psn);
 760                                 /*
 761                                  * Pull back any segments since we are going
 762                                  * to re-receive them.
 763                                  */
 764                                 req->setup_head = req->clear_tail;
 765                                 priv->pending_tid_w_resp +=
 766                                         delta_psn(wqe->lpsn, bth2) + 1;
 767                         }
 768
 769                         trace_hfi1_tid_write_sender_make_req(qp, newreq);
 770                         trace_hfi1_tid_req_make_req_write(qp, newreq,
 771                                                           wqe->wr.opcode,
 772                                                           wqe->psn, wqe->lpsn,
 773                                                           req);
 774                         if (++qp->s_cur == qp->s_size)
 775                                 qp->s_cur = 0;
 776                         break;
 777
 778                 case IB_WR_RDMA_READ:
 779                         /*
 780                          * Don't allow more operations to be started
 781                          * than the QP limits allow.
 782                          */
 783                         if (qp->s_num_rd_atomic >=
 784                             qp->s_max_rd_atomic) {
 785                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
 786                                 goto bail;
 787                         }
 788                         qp->s_num_rd_atomic++;
 789                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 790                                 qp->s_lsn++;
 791                         put_ib_reth_vaddr(
 792                                 wqe->rdma_wr.remote_addr,
 793                                 &ohdr->u.rc.reth);
 794                         ohdr->u.rc.reth.rkey =
 795                                 cpu_to_be32(wqe->rdma_wr.rkey);
 796                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 797                         qp->s_state = OP(RDMA_READ_REQUEST);
 798                         hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
 799                         ss = NULL;
 800                         len = 0;
 801                         bth2 |= IB_BTH_REQ_ACK;
 802                         if (++qp->s_cur == qp->s_size)
 803                                 qp->s_cur = 0;
 804                         break;
 805
 806                 case IB_WR_TID_RDMA_READ:
 807                         trace_hfi1_tid_read_sender_make_req(qp, newreq);
 808                         wpriv = wqe->priv;
 809                         req = wqe_to_tid_req(wqe);
 810                         trace_hfi1_tid_req_make_req_read(qp, newreq,
 811                                                          wqe->wr.opcode,
 812                                                          wqe->psn, wqe->lpsn,
 813                                                          req);
 814                         delta = cmp_psn(qp->s_psn, wqe->psn);
 815
 816                         /*
 817                          * Don't allow more operations to be started
 818                          * than the QP limits allow. We could get here under
 819                          * three conditions; (1) It's a new request; (2) We are
 820                          * sending the second or later segment of a request,
 821                          * but the qp->s_state is set to OP(RDMA_READ_REQUEST)
 822                          * when the last segment of a previous request is
 823                          * received just before this; (3) We are re-sending a
 824                          * request.
 825                          */
 826                         if (qp->s_num_rd_atomic >= qp->s_max_rd_atomic) {
 827                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
 828                                 goto bail;
 829                         }
 830                         if (newreq) {
 831                                 struct tid_rdma_flow *flow =
 832                                         &req->flows[req->setup_head];
 833
 834                                 /*
 835                                  * Set up s_sge as it is needed for TID
 836                                  * allocation. However, if the pages have been
 837                                  * walked and mapped, skip it. An earlier try
 838                                  * has failed to allocate the TID entries.
 839                                  */
 840                                 if (!flow->npagesets) {
 841                                         qp->s_sge.sge = wqe->sg_list[0];
 842                                         qp->s_sge.sg_list = wqe->sg_list + 1;
 843                                         qp->s_sge.num_sge = wqe->wr.num_sge;
 844                                         qp->s_sge.total_len = wqe->length;
 845                                         qp->s_len = wqe->length;
 846                                         req->isge = 0;
 847                                         req->clear_tail = req->setup_head;
 848                                         req->flow_idx = req->setup_head;
 849                                         req->state = TID_REQUEST_ACTIVE;
 850                                 }
 851                         } else if (delta == 0) {
 852                                 /* Re-send a request */
 853                                 req->cur_seg = 0;
 854                                 req->comp_seg = 0;
 855                                 req->ack_pending = 0;
 856                                 req->flow_idx = req->clear_tail;
 857                                 req->state = TID_REQUEST_RESEND;
 858                         }
 859                         req->s_next_psn = qp->s_psn;
 860                         /* Read one segment at a time */
 861                         len = min_t(u32, req->seg_len,
 862                                     wqe->length - req->seg_len * req->cur_seg);
 863                         delta = hfi1_build_tid_rdma_read_req(qp, wqe, ohdr,
 864                                                              &bth1, &bth2,
 865                                                              &len);
 866                         if (delta <= 0) {
 867                                 /* Wait for TID space */
 868                                 goto bail;
 869                         }
 870                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 871                                 qp->s_lsn++;
 872                         hwords += delta;
 873                         ss = &wpriv->ss;
 874                         /* Check if this is the last segment */
 875                         if (req->cur_seg >= req->total_segs &&
 876                             ++qp->s_cur == qp->s_size)
 877                                 qp->s_cur = 0;
 878                         break;
 879
 880                 case IB_WR_ATOMIC_CMP_AND_SWP:
 881                 case IB_WR_ATOMIC_FETCH_AND_ADD:
 882                         /*
 883                          * Don't allow more operations to be started
 884                          * than the QP limits allow.
 885                          */
 886                         if (qp->s_num_rd_atomic >=
 887                             qp->s_max_rd_atomic) {
 888                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
 889                                 goto bail;
 890                         }
 891                         qp->s_num_rd_atomic++;
 892
 893                         /* FALLTHROUGH */
 894                 case IB_WR_OPFN:
 895                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 896                                 qp->s_lsn++;
 897                         if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
 898                             wqe->wr.opcode == IB_WR_OPFN) {
 899                                 qp->s_state = OP(COMPARE_SWAP);
 900                                 put_ib_ateth_swap(wqe->atomic_wr.swap,
 901                                                   &ohdr->u.atomic_eth);
 902                                 put_ib_ateth_compare(wqe->atomic_wr.compare_add,
 903                                                      &ohdr->u.atomic_eth);
 904                         } else {
 905                                 qp->s_state = OP(FETCH_ADD);
 906                                 put_ib_ateth_swap(wqe->atomic_wr.compare_add,
 907                                                   &ohdr->u.atomic_eth);
 908                                 put_ib_ateth_compare(0, &ohdr->u.atomic_eth);
 909                         }
 910                         put_ib_ateth_vaddr(wqe->atomic_wr.remote_addr,
 911                                            &ohdr->u.atomic_eth);
 912                         ohdr->u.atomic_eth.rkey = cpu_to_be32(
 913                                 wqe->atomic_wr.rkey);
 914                         hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
 915                         ss = NULL;
 916                         len = 0;
 917                         bth2 |= IB_BTH_REQ_ACK;
 918                         if (++qp->s_cur == qp->s_size)
 919                                 qp->s_cur = 0;
 920                         break;
 921
 922                 default:
 923                         goto bail;
 924                 }
 925                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ) {
 926                         qp->s_sge.sge = wqe->sg_list[0];
 927                         qp->s_sge.sg_list = wqe->sg_list + 1;
 928                         qp->s_sge.num_sge = wqe->wr.num_sge;
 929                         qp->s_sge.total_len = wqe->length;
 930                         qp->s_len = wqe->length;
 931                 }
 932                 if (newreq) {
 933                         qp->s_tail++;
 934                         if (qp->s_tail >= qp->s_size)
 935                                 qp->s_tail = 0;
 936                 }
 937                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
 938                     wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
 939                         qp->s_psn = wqe->lpsn + 1;
 940                 else if (wqe->wr.opcode == IB_WR_TID_RDMA_READ)
 941                         qp->s_psn = req->s_next_psn;
 942                 else
 943                         qp->s_psn++;
 944                 break;
 945
 946         case OP(RDMA_READ_RESPONSE_FIRST):
 947                 /*
 948                  * qp->s_state is normally set to the opcode of the
 949                  * last packet constructed for new requests and therefore
 950                  * is never set to RDMA read response.
 951                  * RDMA_READ_RESPONSE_FIRST is used by the ACK processing
 952                  * thread to indicate a SEND needs to be restarted from an
 953                  * earlier PSN without interfering with the sending thread.
 954                  * See restart_rc().
 955                  */
 956                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
 957                 /* FALLTHROUGH */
 958         case OP(SEND_FIRST):
 959                 qp->s_state = OP(SEND_MIDDLE);
 960                 /* FALLTHROUGH */
 961         case OP(SEND_MIDDLE):
 962                 bth2 = mask_psn(qp->s_psn++);
 963                 ss = &qp->s_sge;
 964                 len = qp->s_len;
 965                 if (len > pmtu) {
 966                         len = pmtu;
 967                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 968                         break;
 969                 }
 970                 if (wqe->wr.opcode == IB_WR_SEND) {
 971                         qp->s_state = OP(SEND_LAST);
 972                 } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 973                         qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
 974                         /* Immediate data comes after the BTH */
 975                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 976                         hwords += 1;
 977                 } else {
 978                         qp->s_state = OP(SEND_LAST_WITH_INVALIDATE);
 979                         /* invalidate data comes after the BTH */
 980                         ohdr->u.ieth = cpu_to_be32(wqe->wr.ex.invalidate_rkey);
 981                         hwords += 1;
 982                 }
 983                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 984                         bth0 |= IB_BTH_SOLICITED;
 985                 bth2 |= IB_BTH_REQ_ACK;
 986                 qp->s_cur++;
 987                 if (qp->s_cur >= qp->s_size)
 988                         qp->s_cur = 0;
 989                 break;
 990
 991         case OP(RDMA_READ_RESPONSE_LAST):
 992                 /*
 993                  * qp->s_state is normally set to the opcode of the
 994                  * last packet constructed for new requests and therefore
 995                  * is never set to RDMA read response.
 996                  * RDMA_READ_RESPONSE_LAST is used by the ACK processing
 997                  * thread to indicate a RDMA write needs to be restarted from
 998                  * an earlier PSN without interfering with the sending thread.
 999                  * See restart_rc().
1000                  */
1001                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
1002                 /* FALLTHROUGH */
1003         case OP(RDMA_WRITE_FIRST):
1004                 qp->s_state = OP(RDMA_WRITE_MIDDLE);
1005                 /* FALLTHROUGH */
1006         case OP(RDMA_WRITE_MIDDLE):
1007                 bth2 = mask_psn(qp->s_psn++);
1008                 ss = &qp->s_sge;
1009                 len = qp->s_len;
1010                 if (len > pmtu) {
1011                         len = pmtu;
1012                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
1013                         break;
1014                 }
1015                 if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
1016                         qp->s_state = OP(RDMA_WRITE_LAST);
1017                 } else {
1018                         qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
1019                         /* Immediate data comes after the BTH */
1020                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
1021                         hwords += 1;
1022                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
1023                                 bth0 |= IB_BTH_SOLICITED;
1024                 }
1025                 bth2 |= IB_BTH_REQ_ACK;
1026                 qp->s_cur++;
1027                 if (qp->s_cur >= qp->s_size)
1028                         qp->s_cur = 0;
1029                 break;
1030
1031         case OP(RDMA_READ_RESPONSE_MIDDLE):
1032                 /*
1033                  * qp->s_state is normally set to the opcode of the
1034                  * last packet constructed for new requests and therefore
1035                  * is never set to RDMA read response.
1036                  * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing
1037                  * thread to indicate a RDMA read needs to be restarted from
1038                  * an earlier PSN without interfering with the sending thread.
1039                  * See restart_rc().
1040                  */
1041                 len = (delta_psn(qp->s_psn, wqe->psn)) * pmtu;
1042                 put_ib_reth_vaddr(
1043                         wqe->rdma_wr.remote_addr + len,
1044                         &ohdr->u.rc.reth);
1045                 ohdr->u.rc.reth.rkey =
1046                         cpu_to_be32(wqe->rdma_wr.rkey);
1047                 ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len);
1048                 qp->s_state = OP(RDMA_READ_REQUEST);
1049                 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
1050                 bth2 = mask_psn(qp->s_psn) | IB_BTH_REQ_ACK;
1051                 qp->s_psn = wqe->lpsn + 1;
1052                 ss = NULL;
1053                 len = 0;
1054                 qp->s_cur++;
1055                 if (qp->s_cur == qp->s_size)
1056                         qp->s_cur = 0;
1057                 break;
1058
1059         case TID_OP(WRITE_RESP):
1060                 /*
1061                  * This value for s_state is used for restarting a TID RDMA
1062                  * WRITE request. See comment in OP(RDMA_READ_RESPONSE_MIDDLE
1063                  * for more).
1064                  */
1065                 req = wqe_to_tid_req(wqe);
1066                 req->state = TID_REQUEST_RESEND;
1067                 rcu_read_lock();
1068                 remote = rcu_dereference(priv->tid_rdma.remote);
1069                 req->comp_seg = delta_psn(qp->s_psn, wqe->psn);
1070                 len = wqe->length - (req->comp_seg * remote->max_len);
1071                 rcu_read_unlock();
1072
1073                 bth2 = mask_psn(qp->s_psn);
1074                 hwords += hfi1_build_tid_rdma_write_req(qp, wqe, ohdr, &bth1,
1075                                                         &bth2, &len);
1076                 qp->s_psn = wqe->lpsn + 1;
1077                 ss = NULL;
1078                 qp->s_state = TID_OP(WRITE_REQ);
1079                 priv->pending_tid_w_resp += delta_psn(wqe->lpsn, bth2) + 1;
1080                 priv->s_tid_cur = qp->s_cur;
1081                 if (++qp->s_cur == qp->s_size)
1082                         qp->s_cur = 0;
1083                 trace_hfi1_tid_req_make_req_write(qp, 0, wqe->wr.opcode,
1084                                                   wqe->psn, wqe->lpsn, req);
1085                 break;
1086
1087         case TID_OP(READ_RESP):
1088                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ)
1089                         goto bail;
1090                 /* This is used to restart a TID read request */
1091                 req = wqe_to_tid_req(wqe);
1092                 wpriv = wqe->priv;
1093                 /*
1094                  * Back down. The field qp->s_psn has been set to the psn with
1095                  * which the request should be restart. It's OK to use division
1096                  * as this is on the retry path.
1097                  */
1098                 req->cur_seg = delta_psn(qp->s_psn, wqe->psn) / priv->pkts_ps;
1099
1100                 /*
1101                  * The following function need to be redefined to return the
1102                  * status to make sure that we find the flow. At the same
1103                  * time, we can use the req->state change to check if the
1104                  * call succeeds or not.
1105                  */
1106                 req->state = TID_REQUEST_RESEND;
1107                 hfi1_tid_rdma_restart_req(qp, wqe, &bth2);
1108                 if (req->state != TID_REQUEST_ACTIVE) {
1109                         /*
1110                          * Failed to find the flow. Release all allocated tid
1111                          * resources.
1112                          */
1113                         hfi1_kern_exp_rcv_clear_all(req);
1114                         hfi1_kern_clear_hw_flow(priv->rcd, qp);
1115
1116                         hfi1_trdma_send_complete(qp, wqe, IB_WC_LOC_QP_OP_ERR);
1117                         goto bail;
1118                 }
1119                 req->state = TID_REQUEST_RESEND;
1120                 len = min_t(u32, req->seg_len,
1121                             wqe->length - req->seg_len * req->cur_seg);
1122                 flow = &req->flows[req->flow_idx];
1123                 len -= flow->sent;
1124                 req->s_next_psn = flow->flow_state.ib_lpsn + 1;
1125                 delta = hfi1_build_tid_rdma_read_packet(wqe, ohdr, &bth1,
1126                                                         &bth2, &len);
1127                 if (delta <= 0) {
1128                         /* Wait for TID space */
1129                         goto bail;
1130                 }
1131                 hwords += delta;
1132                 ss = &wpriv->ss;
1133                 /* Check if this is the last segment */
1134                 if (req->cur_seg >= req->total_segs &&
1135                     ++qp->s_cur == qp->s_size)
1136                         qp->s_cur = 0;
1137                 qp->s_psn = req->s_next_psn;
1138                 trace_hfi1_tid_req_make_req_read(qp, 0, wqe->wr.opcode,
1139                                                  wqe->psn, wqe->lpsn, req);
1140                 break;
1141         case TID_OP(READ_REQ):
1142                 req = wqe_to_tid_req(wqe);
1143                 delta = cmp_psn(qp->s_psn, wqe->psn);
1144                 /*
1145                  * If the current WR is not TID RDMA READ, or this is the start
1146                  * of a new request, we need to change the qp->s_state so that
1147                  * the request can be set up properly.
1148                  */
1149                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ || delta == 0 ||
1150                     qp->s_cur == qp->s_tail) {
1151                         qp->s_state = OP(RDMA_READ_REQUEST);
1152                         if (delta == 0 || qp->s_cur == qp->s_tail)
1153                                 goto check_s_state;
1154                         else
1155                                 goto bail;
1156                 }
1157
1158                 /* Rate limiting */
1159                 if (qp->s_num_rd_atomic >= qp->s_max_rd_atomic) {
1160                         qp->s_flags |= RVT_S_WAIT_RDMAR;
1161                         goto bail;
1162                 }
1163
1164                 wpriv = wqe->priv;
1165                 /* Read one segment at a time */
1166                 len = min_t(u32, req->seg_len,
1167                             wqe->length - req->seg_len * req->cur_seg);
1168                 delta = hfi1_build_tid_rdma_read_req(qp, wqe, ohdr, &bth1,
1169                                                      &bth2, &len);
1170                 if (delta <= 0) {
1171                         /* Wait for TID space */
1172                         goto bail;
1173                 }
1174                 hwords += delta;
1175                 ss = &wpriv->ss;
1176                 /* Check if this is the last segment */
1177                 if (req->cur_seg >= req->total_segs &&
1178                     ++qp->s_cur == qp->s_size)
1179                         qp->s_cur = 0;
1180                 qp->s_psn = req->s_next_psn;
1181                 trace_hfi1_tid_req_make_req_read(qp, 0, wqe->wr.opcode,
1182                                                  wqe->psn, wqe->lpsn, req);
1183                 break;
1184         }
1185         qp->s_sending_hpsn = bth2;
1186         delta = delta_psn(bth2, wqe->psn);
1187         if (delta && delta % HFI1_PSN_CREDIT == 0 &&
1188             wqe->wr.opcode != IB_WR_TID_RDMA_WRITE)
1189                 bth2 |= IB_BTH_REQ_ACK;
1190         if (qp->s_flags & RVT_S_SEND_ONE) {
1191                 qp->s_flags &= ~RVT_S_SEND_ONE;
1192                 qp->s_flags |= RVT_S_WAIT_ACK;
1193                 bth2 |= IB_BTH_REQ_ACK;
1194         }
1195         qp->s_len -= len;
1196         ps->s_txreq->hdr_dwords = hwords;
1197         ps->s_txreq->sde = priv->s_sde;
1198         ps->s_txreq->ss = ss;
1199         ps->s_txreq->s_cur_size = len;
1200         hfi1_make_ruc_header(
1201                 qp,
1202                 ohdr,
1203                 bth0 | (qp->s_state << 24),
1204                 bth1,
1205                 bth2,
1206                 middle,
1207                 ps);
1208         return 1;
1209
1210 done_free_tx:
1211         hfi1_put_txreq(ps->s_txreq);
1212         ps->s_txreq = NULL;
1213         return 1;
1214
1215 bail:
1216         hfi1_put_txreq(ps->s_txreq);
1217
1218 bail_no_tx:
1219         ps->s_txreq = NULL;
1220         qp->s_flags &= ~RVT_S_BUSY;
1221         /*
1222          * If we didn't get a txreq, the QP will be woken up later to try
1223          * again. Set the flags to indicate which work item to wake
1224          * up.
1225          */
1226         iowait_set_flag(&priv->s_iowait, IOWAIT_PENDING_IB);
1227         return 0;
1228 }
1229
1230 static inline void hfi1_make_bth_aeth(struct rvt_qp *qp,
1231                                       struct ib_other_headers *ohdr,
1232                                       u32 bth0, u32 bth1)
1233 {
1234         if (qp->r_nak_state)
1235                 ohdr->u.aeth = cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
1236                                             (qp->r_nak_state <<
1237                                              IB_AETH_CREDIT_SHIFT));
1238         else
1239                 ohdr->u.aeth = rvt_compute_aeth(qp);
1240
1241         ohdr->bth[0] = cpu_to_be32(bth0);
1242         ohdr->bth[1] = cpu_to_be32(bth1 | qp->remote_qpn);
1243         ohdr->bth[2] = cpu_to_be32(mask_psn(qp->r_ack_psn));
1244 }
1245
1246 static inline void hfi1_queue_rc_ack(struct hfi1_packet *packet, bool is_fecn)
1247 {
1248         struct rvt_qp *qp = packet->qp;
1249         struct hfi1_ibport *ibp;
1250         unsigned long flags;
1251
1252         spin_lock_irqsave(&qp->s_lock, flags);
1253         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
1254                 goto unlock;
1255         ibp = rcd_to_iport(packet->rcd);
1256         this_cpu_inc(*ibp->rvp.rc_qacks);
1257         qp->s_flags |= RVT_S_ACK_PENDING | RVT_S_RESP_PENDING;
1258         qp->s_nak_state = qp->r_nak_state;
1259         qp->s_ack_psn = qp->r_ack_psn;
1260         if (is_fecn)
1261                 qp->s_flags |= RVT_S_ECN;
1262
1263         /* Schedule the send tasklet. */
1264         hfi1_schedule_send(qp);
1265 unlock:
1266         spin_unlock_irqrestore(&qp->s_lock, flags);
1267 }
1268
1269 static inline void hfi1_make_rc_ack_9B(struct hfi1_packet *packet,
1270                                        struct hfi1_opa_header *opa_hdr,
1271                                        u8 sc5, bool is_fecn,
1272                                        u64 *pbc_flags, u32 *hwords,
1273                                        u32 *nwords)
1274 {
1275         struct rvt_qp *qp = packet->qp;
1276         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
1277         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1278         struct ib_header *hdr = &opa_hdr->ibh;
1279         struct ib_other_headers *ohdr;
1280         u16 lrh0 = HFI1_LRH_BTH;
1281         u16 pkey;
1282         u32 bth0, bth1;
1283
1284         opa_hdr->hdr_type = HFI1_PKT_TYPE_9B;
1285         ohdr = &hdr->u.oth;
1286         /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4 */
1287         *hwords = 6;
1288
1289         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)) {
1290                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
1291                                          rdma_ah_read_grh(&qp->remote_ah_attr),
1292                                          *hwords - 2, SIZE_OF_CRC);
1293                 ohdr = &hdr->u.l.oth;
1294                 lrh0 = HFI1_LRH_GRH;
1295         }
1296         /* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
1297         *pbc_flags |= ((!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT);
1298
1299         /* read pkey_index w/o lock (its atomic) */
1300         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
1301
1302         lrh0 |= (sc5 & IB_SC_MASK) << IB_SC_SHIFT |
1303                 (rdma_ah_get_sl(&qp->remote_ah_attr) & IB_SL_MASK) <<
1304                         IB_SL_SHIFT;
1305
1306         hfi1_make_ib_hdr(hdr, lrh0, *hwords + SIZE_OF_CRC,
1307                          opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr), 9B),
1308                          ppd->lid | rdma_ah_get_path_bits(&qp->remote_ah_attr));
1309
1310         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
1311         if (qp->s_mig_state == IB_MIG_MIGRATED)
1312                 bth0 |= IB_BTH_MIG_REQ;
1313         bth1 = (!!is_fecn) << IB_BECN_SHIFT;
1314         /*
1315          * Inline ACKs go out without the use of the Verbs send engine, so
1316          * we need to set the STL Verbs Extended bit here
1317          */
1318         bth1 |= HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT;
1319         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
1320 }
1321
1322 static inline void hfi1_make_rc_ack_16B(struct hfi1_packet *packet,
1323                                         struct hfi1_opa_header *opa_hdr,
1324                                         u8 sc5, bool is_fecn,
1325                                         u64 *pbc_flags, u32 *hwords,
1326                                         u32 *nwords)
1327 {
1328         struct rvt_qp *qp = packet->qp;
1329         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
1330         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1331         struct hfi1_16b_header *hdr = &opa_hdr->opah;
1332         struct ib_other_headers *ohdr;
1333         u32 bth0, bth1 = 0;
1334         u16 len, pkey;
1335         bool becn = is_fecn;
1336         u8 l4 = OPA_16B_L4_IB_LOCAL;
1337         u8 extra_bytes;
1338
1339         opa_hdr->hdr_type = HFI1_PKT_TYPE_16B;
1340         ohdr = &hdr->u.oth;
1341         /* header size in 32-bit words 16B LRH+BTH+AETH = (16+12+4)/4 */
1342         *hwords = 8;
1343         extra_bytes = hfi1_get_16b_padding(*hwords << 2, 0);
1344         *nwords = SIZE_OF_CRC + ((extra_bytes + SIZE_OF_LT) >> 2);
1345
1346         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
1347             hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))) {
1348                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
1349                                          rdma_ah_read_grh(&qp->remote_ah_attr),
1350                                          *hwords - 4, *nwords);
1351                 ohdr = &hdr->u.l.oth;
1352                 l4 = OPA_16B_L4_IB_GLOBAL;
1353         }
1354         *pbc_flags |= PBC_PACKET_BYPASS | PBC_INSERT_BYPASS_ICRC;
1355
1356         /* read pkey_index w/o lock (its atomic) */
1357         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
1358
1359         /* Convert dwords to flits */
1360         len = (*hwords + *nwords) >> 1;
1361
1362         hfi1_make_16b_hdr(hdr, ppd->lid |
1363                           (rdma_ah_get_path_bits(&qp->remote_ah_attr) &
1364                           ((1 << ppd->lmc) - 1)),
1365                           opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr),
1366                                       16B), len, pkey, becn, 0, l4, sc5);
1367
1368         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
1369         bth0 |= extra_bytes << 20;
1370         if (qp->s_mig_state == IB_MIG_MIGRATED)
1371                 bth1 = OPA_BTH_MIG_REQ;
1372         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
1373 }
1374
1375 typedef void (*hfi1_make_rc_ack)(struct hfi1_packet *packet,
1376                                  struct hfi1_opa_header *opa_hdr,
1377                                  u8 sc5, bool is_fecn,
1378                                  u64 *pbc_flags, u32 *hwords,
1379                                  u32 *nwords);
1380
1381 /* We support only two types - 9B and 16B for now */
1382 static const hfi1_make_rc_ack hfi1_make_rc_ack_tbl[2] = {
1383         [HFI1_PKT_TYPE_9B] = &hfi1_make_rc_ack_9B,
1384         [HFI1_PKT_TYPE_16B] = &hfi1_make_rc_ack_16B
1385 };
1386
1387 /**
1388  * hfi1_send_rc_ack - Construct an ACK packet and send it
1389  * @qp: a pointer to the QP
1390  *
1391  * This is called from hfi1_rc_rcv() and handle_receive_interrupt().
1392  * Note that RDMA reads and atomics are handled in the
1393  * send side QP state and send engine.
1394  */
1395 void hfi1_send_rc_ack(struct hfi1_packet *packet, bool is_fecn)
1396 {
1397         struct hfi1_ctxtdata *rcd = packet->rcd;
1398         struct rvt_qp *qp = packet->qp;
1399         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
1400         struct hfi1_qp_priv *priv = qp->priv;
1401         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1402         u8 sc5 = ibp->sl_to_sc[rdma_ah_get_sl(&qp->remote_ah_attr)];
1403         u64 pbc, pbc_flags = 0;
1404         u32 hwords = 0;
1405         u32 nwords = 0;
1406         u32 plen;
1407         struct pio_buf *pbuf;
1408         struct hfi1_opa_header opa_hdr;
1409
1410         /* clear the defer count */
1411         qp->r_adefered = 0;
1412
1413         /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
1414         if (qp->s_flags & RVT_S_RESP_PENDING) {
1415                 hfi1_queue_rc_ack(packet, is_fecn);
1416                 return;
1417         }
1418
1419         /* Ensure s_rdma_ack_cnt changes are committed */
1420         if (qp->s_rdma_ack_cnt) {
1421                 hfi1_queue_rc_ack(packet, is_fecn);
1422                 return;
1423         }
1424
1425         /* Don't try to send ACKs if the link isn't ACTIVE */
1426         if (driver_lstate(ppd) != IB_PORT_ACTIVE)
1427                 return;
1428
1429         /* Make the appropriate header */
1430         hfi1_make_rc_ack_tbl[priv->hdr_type](packet, &opa_hdr, sc5, is_fecn,
1431                                              &pbc_flags, &hwords, &nwords);
1432
1433         plen = 2 /* PBC */ + hwords + nwords;
1434         pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps,
1435                          sc_to_vlt(ppd->dd, sc5), plen);
1436         pbuf = sc_buffer_alloc(rcd->sc, plen, NULL, NULL);
1437         if (!pbuf) {
1438                 /*
1439                  * We have no room to send at the moment.  Pass
1440                  * responsibility for sending the ACK to the send engine
1441                  * so that when enough buffer space becomes available,
1442                  * the ACK is sent ahead of other outgoing packets.
1443                  */
1444                 hfi1_queue_rc_ack(packet, is_fecn);
1445                 return;
1446         }
1447         trace_ack_output_ibhdr(dd_from_ibdev(qp->ibqp.device),
1448                                &opa_hdr, ib_is_sc5(sc5));
1449
1450         /* write the pbc and data */
1451         ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc,
1452                                  (priv->hdr_type == HFI1_PKT_TYPE_9B ?
1453                                  (void *)&opa_hdr.ibh :
1454                                  (void *)&opa_hdr.opah), hwords);
1455         return;
1456 }
1457
1458 /**
1459  * update_num_rd_atomic - update the qp->s_num_rd_atomic
1460  * @qp: the QP
1461  * @psn: the packet sequence number to restart at
1462  * @wqe: the wqe
1463  *
1464  * This is called from reset_psn() to update qp->s_num_rd_atomic
1465  * for the current wqe.
1466  * Called at interrupt level with the QP s_lock held.
1467  */
1468 static void update_num_rd_atomic(struct rvt_qp *qp, u32 psn,
1469                                  struct rvt_swqe *wqe)
1470 {
1471         u32 opcode = wqe->wr.opcode;
1472
1473         if (opcode == IB_WR_RDMA_READ ||
1474             opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1475             opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
1476                 qp->s_num_rd_atomic++;
1477         } else if (opcode == IB_WR_TID_RDMA_READ) {
1478                 struct tid_rdma_request *req = wqe_to_tid_req(wqe);
1479                 struct hfi1_qp_priv *priv = qp->priv;
1480
1481                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
1482                         u32 cur_seg;
1483
1484                         cur_seg = (psn - wqe->psn) / priv->pkts_ps;
1485                         req->ack_pending = cur_seg - req->comp_seg;
1486                         priv->pending_tid_r_segs += req->ack_pending;
1487                         qp->s_num_rd_atomic += req->ack_pending;
1488                 } else {
1489                         priv->pending_tid_r_segs += req->total_segs;
1490                         qp->s_num_rd_atomic += req->total_segs;
1491                 }
1492         }
1493 }
1494
1495 /**
1496  * reset_psn - reset the QP state to send starting from PSN
1497  * @qp: the QP
1498  * @psn: the packet sequence number to restart at
1499  *
1500  * This is called from hfi1_rc_rcv() to process an incoming RC ACK
1501  * for the given QP.
1502  * Called at interrupt level with the QP s_lock held.
1503  */
1504 static void reset_psn(struct rvt_qp *qp, u32 psn)
1505 {
1506         u32 n = qp->s_acked;
1507         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, n);
1508         u32 opcode;
1509         struct hfi1_qp_priv *priv = qp->priv;
1510
1511         lockdep_assert_held(&qp->s_lock);
1512         qp->s_cur = n;
1513         priv->pending_tid_r_segs = 0;
1514         priv->pending_tid_w_resp = 0;
1515         qp->s_num_rd_atomic = 0;
1516
1517         /*
1518          * If we are starting the request from the beginning,
1519          * let the normal send code handle initialization.
1520          */
1521         if (cmp_psn(psn, wqe->psn) <= 0) {
1522                 qp->s_state = OP(SEND_LAST);
1523                 goto done;
1524         }
1525         update_num_rd_atomic(qp, psn, wqe);
1526
1527         /* Find the work request opcode corresponding to the given PSN. */
1528         for (;;) {
1529                 int diff;
1530
1531                 if (++n == qp->s_size)
1532                         n = 0;
1533                 if (n == qp->s_tail)
1534                         break;
1535                 wqe = rvt_get_swqe_ptr(qp, n);
1536                 diff = cmp_psn(psn, wqe->psn);
1537                 if (diff < 0) {
1538                         /* Point wqe back to the previous one*/
1539                         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1540                         break;
1541                 }
1542                 qp->s_cur = n;
1543                 /*
1544                  * If we are starting the request from the beginning,
1545                  * let the normal send code handle initialization.
1546                  */
1547                 if (diff == 0) {
1548                         qp->s_state = OP(SEND_LAST);
1549                         goto done;
1550                 }
1551
1552                 update_num_rd_atomic(qp, psn, wqe);
1553         }
1554         opcode = wqe->wr.opcode;
1555
1556         /*
1557          * Set the state to restart in the middle of a request.
1558          * Don't change the s_sge, s_cur_sge, or s_cur_size.
1559          * See hfi1_make_rc_req().
1560          */
1561         switch (opcode) {
1562         case IB_WR_SEND:
1563         case IB_WR_SEND_WITH_IMM:
1564                 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
1565                 break;
1566
1567         case IB_WR_RDMA_WRITE:
1568         case IB_WR_RDMA_WRITE_WITH_IMM:
1569                 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
1570                 break;
1571
1572         case IB_WR_TID_RDMA_WRITE:
1573                 qp->s_state = TID_OP(WRITE_RESP);
1574                 break;
1575
1576         case IB_WR_RDMA_READ:
1577                 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
1578                 break;
1579
1580         case IB_WR_TID_RDMA_READ:
1581                 qp->s_state = TID_OP(READ_RESP);
1582                 break;
1583
1584         default:
1585                 /*
1586                  * This case shouldn't happen since its only
1587                  * one PSN per req.
1588                  */
1589                 qp->s_state = OP(SEND_LAST);
1590         }
1591 done:
1592         priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
1593         qp->s_psn = psn;
1594         /*
1595          * Set RVT_S_WAIT_PSN as rc_complete() may start the timer
1596          * asynchronously before the send engine can get scheduled.
1597          * Doing it in hfi1_make_rc_req() is too late.
1598          */
1599         if ((cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) &&
1600             (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0))
1601                 qp->s_flags |= RVT_S_WAIT_PSN;
1602         qp->s_flags &= ~HFI1_S_AHG_VALID;
1603         trace_hfi1_sender_reset_psn(qp);
1604 }
1605
1606 /*
1607  * Back up requester to resend the last un-ACKed request.
1608  * The QP r_lock and s_lock should be held and interrupts disabled.
1609  */
1610 void hfi1_restart_rc(struct rvt_qp *qp, u32 psn, int wait)
1611 {
1612         struct hfi1_qp_priv *priv = qp->priv;
1613         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1614         struct hfi1_ibport *ibp;
1615
1616         lockdep_assert_held(&qp->r_lock);
1617         lockdep_assert_held(&qp->s_lock);
1618         trace_hfi1_sender_restart_rc(qp);
1619         if (qp->s_retry == 0) {
1620                 if (qp->s_mig_state == IB_MIG_ARMED) {
1621                         hfi1_migrate_qp(qp);
1622                         qp->s_retry = qp->s_retry_cnt;
1623                 } else if (qp->s_last == qp->s_acked) {
1624                         /*
1625                          * We need special handling for the OPFN request WQEs as
1626                          * they are not allowed to generate real user errors
1627                          */
1628                         if (wqe->wr.opcode == IB_WR_OPFN) {
1629                                 struct hfi1_ibport *ibp =
1630                                         to_iport(qp->ibqp.device, qp->port_num);
1631                                 /*
1632                                  * Call opfn_conn_reply() with capcode and
1633                                  * remaining data as 0 to close out the
1634                                  * current request
1635                                  */
1636                                 opfn_conn_reply(qp, priv->opfn.curr);
1637                                 wqe = do_rc_completion(qp, wqe, ibp);
1638                                 qp->s_flags &= ~RVT_S_WAIT_ACK;
1639                         } else {
1640                                 trace_hfi1_tid_write_sender_restart_rc(qp, 0);
1641                                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ) {
1642                                         struct tid_rdma_request *req;
1643
1644                                         req = wqe_to_tid_req(wqe);
1645                                         hfi1_kern_exp_rcv_clear_all(req);
1646                                         hfi1_kern_clear_hw_flow(priv->rcd, qp);
1647                                 }
1648
1649                                 hfi1_trdma_send_complete(qp, wqe,
1650                                                          IB_WC_RETRY_EXC_ERR);
1651                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1652                         }
1653                         return;
1654                 } else { /* need to handle delayed completion */
1655                         return;
1656                 }
1657         } else {
1658                 qp->s_retry--;
1659         }
1660
1661         ibp = to_iport(qp->ibqp.device, qp->port_num);
1662         if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1663             wqe->wr.opcode == IB_WR_TID_RDMA_READ)
1664                 ibp->rvp.n_rc_resends++;
1665         else
1666                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
1667
1668         qp->s_flags &= ~(RVT_S_WAIT_FENCE | RVT_S_WAIT_RDMAR |
1669                          RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_PSN |
1670                          RVT_S_WAIT_ACK | HFI1_S_WAIT_TID_RESP);
1671         if (wait)
1672                 qp->s_flags |= RVT_S_SEND_ONE;
1673         reset_psn(qp, psn);
1674 }
1675
1676 /*
1677  * Set qp->s_sending_psn to the next PSN after the given one.
1678  * This would be psn+1 except when RDMA reads or TID RDMA ops
1679  * are present.
1680  */
1681 static void reset_sending_psn(struct rvt_qp *qp, u32 psn)
1682 {
1683         struct rvt_swqe *wqe;
1684         u32 n = qp->s_last;
1685
1686         lockdep_assert_held(&qp->s_lock);
1687         /* Find the work request corresponding to the given PSN. */
1688         for (;;) {
1689                 wqe = rvt_get_swqe_ptr(qp, n);
1690                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
1691                         if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1692                             wqe->wr.opcode == IB_WR_TID_RDMA_READ ||
1693                             wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
1694                                 qp->s_sending_psn = wqe->lpsn + 1;
1695                         else
1696                                 qp->s_sending_psn = psn + 1;
1697                         break;
1698                 }
1699                 if (++n == qp->s_size)
1700                         n = 0;
1701                 if (n == qp->s_tail)
1702                         break;
1703         }
1704 }
1705
1706 /*
1707  * This should be called with the QP s_lock held and interrupts disabled.
1708  */
1709 void hfi1_rc_send_complete(struct rvt_qp *qp, struct hfi1_opa_header *opah)
1710 {
1711         struct ib_other_headers *ohdr;
1712         struct hfi1_qp_priv *priv = qp->priv;
1713         struct rvt_swqe *wqe;
1714         struct ib_header *hdr = NULL;
1715         struct hfi1_16b_header *hdr_16b = NULL;
1716         u32 opcode, head, tail;
1717         u32 psn;
1718         struct tid_rdma_request *req;
1719
1720         lockdep_assert_held(&qp->s_lock);
1721         if (!(ib_rvt_state_ops[qp->state] & RVT_SEND_OR_FLUSH_OR_RECV_OK))
1722                 return;
1723
1724         /* Find out where the BTH is */
1725         if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
1726                 hdr = &opah->ibh;
1727                 if (ib_get_lnh(hdr) == HFI1_LRH_BTH)
1728                         ohdr = &hdr->u.oth;
1729                 else
1730                         ohdr = &hdr->u.l.oth;
1731         } else {
1732                 u8 l4;
1733
1734                 hdr_16b = &opah->opah;
1735                 l4  = hfi1_16B_get_l4(hdr_16b);
1736                 if (l4 == OPA_16B_L4_IB_LOCAL)
1737                         ohdr = &hdr_16b->u.oth;
1738                 else
1739                         ohdr = &hdr_16b->u.l.oth;
1740         }
1741
1742         opcode = ib_bth_get_opcode(ohdr);
1743         if ((opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1744              opcode <= OP(ATOMIC_ACKNOWLEDGE)) ||
1745             opcode == TID_OP(READ_RESP) ||
1746             opcode == TID_OP(WRITE_RESP)) {
1747                 WARN_ON(!qp->s_rdma_ack_cnt);
1748                 qp->s_rdma_ack_cnt--;
1749                 return;
1750         }
1751
1752         psn = ib_bth_get_psn(ohdr);
1753         /*
1754          * Don't attempt to reset the sending PSN for packets in the
1755          * KDETH PSN space since the PSN does not match anything.
1756          */
1757         if (opcode != TID_OP(WRITE_DATA) &&
1758             opcode != TID_OP(WRITE_DATA_LAST) &&
1759             opcode != TID_OP(ACK) && opcode != TID_OP(RESYNC))
1760                 reset_sending_psn(qp, psn);
1761
1762         /* Handle TID RDMA WRITE packets differently */
1763         if (opcode >= TID_OP(WRITE_REQ) &&
1764             opcode <= TID_OP(WRITE_DATA_LAST)) {
1765                 head = priv->s_tid_head;
1766                 tail = priv->s_tid_cur;
1767                 /*
1768                  * s_tid_cur is set to s_tid_head in the case, where
1769                  * a new TID RDMA request is being started and all
1770                  * previous ones have been completed.
1771                  * Therefore, we need to do a secondary check in order
1772                  * to properly determine whether we should start the
1773                  * RC timer.
1774                  */
1775                 wqe = rvt_get_swqe_ptr(qp, tail);
1776                 req = wqe_to_tid_req(wqe);
1777                 if (head == tail && req->comp_seg < req->total_segs) {
1778                         if (tail == 0)
1779                                 tail = qp->s_size - 1;
1780                         else
1781                                 tail -= 1;
1782                 }
1783         } else {
1784                 head = qp->s_tail;
1785                 tail = qp->s_acked;
1786         }
1787
1788         /*
1789          * Start timer after a packet requesting an ACK has been sent and
1790          * there are still requests that haven't been acked.
1791          */
1792         if ((psn & IB_BTH_REQ_ACK) && tail != head &&
1793             opcode != TID_OP(WRITE_DATA) && opcode != TID_OP(WRITE_DATA_LAST) &&
1794             opcode != TID_OP(RESYNC) &&
1795             !(qp->s_flags &
1796               (RVT_S_TIMER | RVT_S_WAIT_RNR | RVT_S_WAIT_PSN)) &&
1797             (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
1798                 if (opcode == TID_OP(READ_REQ))
1799                         rvt_add_retry_timer_ext(qp, priv->timeout_shift);
1800                 else
1801                         rvt_add_retry_timer(qp);
1802         }
1803
1804         /* Start TID RDMA ACK timer */
1805         if ((opcode == TID_OP(WRITE_DATA) ||
1806              opcode == TID_OP(WRITE_DATA_LAST) ||
1807              opcode == TID_OP(RESYNC)) &&
1808             (psn & IB_BTH_REQ_ACK) &&
1809             !(priv->s_flags & HFI1_S_TID_RETRY_TIMER) &&
1810             (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
1811                 /*
1812                  * The TID RDMA ACK packet could be received before this
1813                  * function is called. Therefore, add the timer only if TID
1814                  * RDMA ACK packets are actually pending.
1815                  */
1816                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1817                 req = wqe_to_tid_req(wqe);
1818                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
1819                     req->ack_seg < req->cur_seg)
1820                         hfi1_add_tid_retry_timer(qp);
1821         }
1822
1823         while (qp->s_last != qp->s_acked) {
1824                 u32 s_last;
1825
1826                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
1827                 if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 &&
1828                     cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
1829                         break;
1830                 trdma_clean_swqe(qp, wqe);
1831                 rvt_qp_wqe_unreserve(qp, wqe);
1832                 s_last = qp->s_last;
1833                 trace_hfi1_qp_send_completion(qp, wqe, s_last);
1834                 if (++s_last >= qp->s_size)
1835                         s_last = 0;
1836                 qp->s_last = s_last;
1837                 /* see post_send() */
1838                 barrier();
1839                 rvt_put_swqe(wqe);
1840                 rvt_qp_swqe_complete(qp,
1841                                      wqe,
1842                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1843                                      IB_WC_SUCCESS);
1844         }
1845         /*
1846          * If we were waiting for sends to complete before re-sending,
1847          * and they are now complete, restart sending.
1848          */
1849         trace_hfi1_sendcomplete(qp, psn);
1850         if (qp->s_flags & RVT_S_WAIT_PSN &&
1851             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1852                 qp->s_flags &= ~RVT_S_WAIT_PSN;
1853                 qp->s_sending_psn = qp->s_psn;
1854                 qp->s_sending_hpsn = qp->s_psn - 1;
1855                 hfi1_schedule_send(qp);
1856         }
1857 }
1858
1859 static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
1860 {
1861         qp->s_last_psn = psn;
1862 }
1863
1864 /*
1865  * Generate a SWQE completion.
1866  * This is similar to hfi1_send_complete but has to check to be sure
1867  * that the SGEs are not being referenced if the SWQE is being resent.
1868  */
1869 struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
1870                                   struct rvt_swqe *wqe,
1871                                   struct hfi1_ibport *ibp)
1872 {
1873         struct hfi1_qp_priv *priv = qp->priv;
1874
1875         lockdep_assert_held(&qp->s_lock);
1876         /*
1877          * Don't decrement refcount and don't generate a
1878          * completion if the SWQE is being resent until the send
1879          * is finished.
1880          */
1881         trace_hfi1_rc_completion(qp, wqe->lpsn);
1882         if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 ||
1883             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1884                 u32 s_last;
1885
1886                 trdma_clean_swqe(qp, wqe);
1887                 rvt_put_swqe(wqe);
1888                 rvt_qp_wqe_unreserve(qp, wqe);
1889                 s_last = qp->s_last;
1890                 trace_hfi1_qp_send_completion(qp, wqe, s_last);
1891                 if (++s_last >= qp->s_size)
1892                         s_last = 0;
1893                 qp->s_last = s_last;
1894                 /* see post_send() */
1895                 barrier();
1896                 rvt_qp_swqe_complete(qp,
1897                                      wqe,
1898                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1899                                      IB_WC_SUCCESS);
1900         } else {
1901                 struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1902
1903                 this_cpu_inc(*ibp->rvp.rc_delayed_comp);
1904                 /*
1905                  * If send progress not running attempt to progress
1906                  * SDMA queue.
1907                  */
1908                 if (ppd->dd->flags & HFI1_HAS_SEND_DMA) {
1909                         struct sdma_engine *engine;
1910                         u8 sl = rdma_ah_get_sl(&qp->remote_ah_attr);
1911                         u8 sc5;
1912
1913                         /* For now use sc to find engine */
1914                         sc5 = ibp->sl_to_sc[sl];
1915                         engine = qp_to_sdma_engine(qp, sc5);
1916                         sdma_engine_progress_schedule(engine);
1917                 }
1918         }
1919
1920         qp->s_retry = qp->s_retry_cnt;
1921         /*
1922          * Don't update the last PSN if the request being completed is
1923          * a TID RDMA WRITE request.
1924          * Completion of the TID RDMA WRITE requests are done by the
1925          * TID RDMA ACKs and as such could be for a request that has
1926          * already been ACKed as far as the IB state machine is
1927          * concerned.
1928          */
1929         if (wqe->wr.opcode != IB_WR_TID_RDMA_WRITE)
1930                 update_last_psn(qp, wqe->lpsn);
1931
1932         /*
1933          * If we are completing a request which is in the process of
1934          * being resent, we can stop re-sending it since we know the
1935          * responder has already seen it.
1936          */
1937         if (qp->s_acked == qp->s_cur) {
1938                 if (++qp->s_cur >= qp->s_size)
1939                         qp->s_cur = 0;
1940                 qp->s_acked = qp->s_cur;
1941                 wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1942                 if (qp->s_acked != qp->s_tail) {
1943                         qp->s_state = OP(SEND_LAST);
1944                         qp->s_psn = wqe->psn;
1945                 }
1946         } else {
1947                 if (++qp->s_acked >= qp->s_size)
1948                         qp->s_acked = 0;
1949                 if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur)
1950                         qp->s_draining = 0;
1951                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1952         }
1953         if (priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) {
1954                 priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
1955                 hfi1_schedule_send(qp);
1956         }
1957         return wqe;
1958 }
1959
1960 static void set_restart_qp(struct rvt_qp *qp, struct hfi1_ctxtdata *rcd)
1961 {
1962         /* Retry this request. */
1963         if (!(qp->r_flags & RVT_R_RDMAR_SEQ)) {
1964                 qp->r_flags |= RVT_R_RDMAR_SEQ;
1965                 hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
1966                 if (list_empty(&qp->rspwait)) {
1967                         qp->r_flags |= RVT_R_RSP_SEND;
1968                         rvt_get_qp(qp);
1969                         list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1970                 }
1971         }
1972 }
1973
1974 /**
1975  * update_qp_retry_state - Update qp retry state.
1976  * @qp: the QP
1977  * @psn: the packet sequence number of the TID RDMA WRITE RESP.
1978  * @spsn:  The start psn for the given TID RDMA WRITE swqe.
1979  * @lpsn:  The last psn for the given TID RDMA WRITE swqe.
1980  *
1981  * This function is called to update the qp retry state upon
1982  * receiving a TID WRITE RESP after the qp is scheduled to retry
1983  * a request.
1984  */
1985 static void update_qp_retry_state(struct rvt_qp *qp, u32 psn, u32 spsn,
1986                                   u32 lpsn)
1987 {
1988         struct hfi1_qp_priv *qpriv = qp->priv;
1989
1990         qp->s_psn = psn + 1;
1991         /*
1992          * If this is the first TID RDMA WRITE RESP packet for the current
1993          * request, change the s_state so that the retry will be processed
1994          * correctly. Similarly, if this is the last TID RDMA WRITE RESP
1995          * packet, change the s_state and advance the s_cur.
1996          */
1997         if (cmp_psn(psn, lpsn) >= 0) {
1998                 qp->s_cur = qpriv->s_tid_cur + 1;
1999                 if (qp->s_cur >= qp->s_size)
2000                         qp->s_cur = 0;
2001                 qp->s_state = TID_OP(WRITE_REQ);
2002         } else  if (!cmp_psn(psn, spsn)) {
2003                 qp->s_cur = qpriv->s_tid_cur;
2004                 qp->s_state = TID_OP(WRITE_RESP);
2005         }
2006 }
2007
2008 /**
2009  * do_rc_ack - process an incoming RC ACK
2010  * @qp: the QP the ACK came in on
2011  * @psn: the packet sequence number of the ACK
2012  * @opcode: the opcode of the request that resulted in the ACK
2013  *
2014  * This is called from rc_rcv_resp() to process an incoming RC ACK
2015  * for the given QP.
2016  * May be called at interrupt level, with the QP s_lock held.
2017  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
2018  */
2019 int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
2020               u64 val, struct hfi1_ctxtdata *rcd)
2021 {
2022         struct hfi1_ibport *ibp;
2023         enum ib_wc_status status;
2024         struct hfi1_qp_priv *qpriv = qp->priv;
2025         struct rvt_swqe *wqe;
2026         int ret = 0;
2027         u32 ack_psn;
2028         int diff;
2029         struct rvt_dev_info *rdi;
2030
2031         lockdep_assert_held(&qp->s_lock);
2032         /*
2033          * Note that NAKs implicitly ACK outstanding SEND and RDMA write
2034          * requests and implicitly NAK RDMA read and atomic requests issued
2035          * before the NAK'ed request.  The MSN won't include the NAK'ed
2036          * request but will include an ACK'ed request(s).
2037          */
2038         ack_psn = psn;
2039         if (aeth >> IB_AETH_NAK_SHIFT)
2040                 ack_psn--;
2041         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2042         ibp = rcd_to_iport(rcd);
2043
2044         /*
2045          * The MSN might be for a later WQE than the PSN indicates so
2046          * only complete WQEs that the PSN finishes.
2047          */
2048         while ((diff = delta_psn(ack_psn, wqe->lpsn)) >= 0) {
2049                 /*
2050                  * RDMA_READ_RESPONSE_ONLY is a special case since
2051                  * we want to generate completion events for everything
2052                  * before the RDMA read, copy the data, then generate
2053                  * the completion for the read.
2054                  */
2055                 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
2056                     opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
2057                     diff == 0) {
2058                         ret = 1;
2059                         goto bail_stop;
2060                 }
2061                 /*
2062                  * If this request is a RDMA read or atomic, and the ACK is
2063                  * for a later operation, this ACK NAKs the RDMA read or
2064                  * atomic.  In other words, only a RDMA_READ_LAST or ONLY
2065                  * can ACK a RDMA read and likewise for atomic ops.  Note
2066                  * that the NAK case can only happen if relaxed ordering is
2067                  * used and requests are sent after an RDMA read or atomic
2068                  * is sent but before the response is received.
2069                  */
2070                 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
2071                      (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
2072                     (wqe->wr.opcode == IB_WR_TID_RDMA_READ &&
2073                      (opcode != TID_OP(READ_RESP) || diff != 0)) ||
2074                     ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2075                       wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
2076                      (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0)) ||
2077                     (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2078                      (delta_psn(psn, qp->s_last_psn) != 1))) {
2079                         set_restart_qp(qp, rcd);
2080                         /*
2081                          * No need to process the ACK/NAK since we are
2082                          * restarting an earlier request.
2083                          */
2084                         goto bail_stop;
2085                 }
2086                 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2087                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
2088                         u64 *vaddr = wqe->sg_list[0].vaddr;
2089                         *vaddr = val;
2090                 }
2091                 if (wqe->wr.opcode == IB_WR_OPFN)
2092                         opfn_conn_reply(qp, val);
2093
2094                 if (qp->s_num_rd_atomic &&
2095                     (wqe->wr.opcode == IB_WR_RDMA_READ ||
2096                      wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2097                      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
2098                         qp->s_num_rd_atomic--;
2099                         /* Restart sending task if fence is complete */
2100                         if ((qp->s_flags & RVT_S_WAIT_FENCE) &&
2101                             !qp->s_num_rd_atomic) {
2102                                 qp->s_flags &= ~(RVT_S_WAIT_FENCE |
2103                                                  RVT_S_WAIT_ACK);
2104                                 hfi1_schedule_send(qp);
2105                         } else if (qp->s_flags & RVT_S_WAIT_RDMAR) {
2106                                 qp->s_flags &= ~(RVT_S_WAIT_RDMAR |
2107                                                  RVT_S_WAIT_ACK);
2108                                 hfi1_schedule_send(qp);
2109                         }
2110                 }
2111
2112                 /*
2113                  * TID RDMA WRITE requests will be completed by the TID RDMA
2114                  * ACK packet handler (see tid_rdma.c).
2115                  */
2116                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
2117                         break;
2118
2119                 wqe = do_rc_completion(qp, wqe, ibp);
2120                 if (qp->s_acked == qp->s_tail)
2121                         break;
2122         }
2123
2124         trace_hfi1_rc_ack_do(qp, aeth, psn, wqe);
2125         trace_hfi1_sender_do_rc_ack(qp);
2126         switch (aeth >> IB_AETH_NAK_SHIFT) {
2127         case 0:         /* ACK */
2128                 this_cpu_inc(*ibp->rvp.rc_acks);
2129                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ) {
2130                         if (wqe_to_tid_req(wqe)->ack_pending)
2131                                 rvt_mod_retry_timer_ext(qp,
2132                                                         qpriv->timeout_shift);
2133                         else
2134                                 rvt_stop_rc_timers(qp);
2135                 } else if (qp->s_acked != qp->s_tail) {
2136                         struct rvt_swqe *__w = NULL;
2137
2138                         if (qpriv->s_tid_cur != HFI1_QP_WQE_INVALID)
2139                                 __w = rvt_get_swqe_ptr(qp, qpriv->s_tid_cur);
2140
2141                         /*
2142                          * Stop timers if we've received all of the TID RDMA
2143                          * WRITE * responses.
2144                          */
2145                         if (__w && __w->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2146                             opcode == TID_OP(WRITE_RESP)) {
2147                                 /*
2148                                  * Normally, the loop above would correctly
2149                                  * process all WQEs from s_acked onward and
2150                                  * either complete them or check for correct
2151                                  * PSN sequencing.
2152                                  * However, for TID RDMA, due to pipelining,
2153                                  * the response may not be for the request at
2154                                  * s_acked so the above look would just be
2155                                  * skipped. This does not allow for checking
2156                                  * the PSN sequencing. It has to be done
2157                                  * separately.
2158                                  */
2159                                 if (cmp_psn(psn, qp->s_last_psn + 1)) {
2160                                         set_restart_qp(qp, rcd);
2161                                         goto bail_stop;
2162                                 }
2163                                 /*
2164                                  * If the psn is being resent, stop the
2165                                  * resending.
2166                                  */
2167                                 if (qp->s_cur != qp->s_tail &&
2168                                     cmp_psn(qp->s_psn, psn) <= 0)
2169                                         update_qp_retry_state(qp, psn,
2170                                                               __w->psn,
2171                                                               __w->lpsn);
2172                                 else if (--qpriv->pending_tid_w_resp)
2173                                         rvt_mod_retry_timer(qp);
2174                                 else
2175                                         rvt_stop_rc_timers(qp);
2176                         } else {
2177                                 /*
2178                                  * We are expecting more ACKs so
2179                                  * mod the retry timer.
2180                                  */
2181                                 rvt_mod_retry_timer(qp);
2182                                 /*
2183                                  * We can stop re-sending the earlier packets
2184                                  * and continue with the next packet the
2185                                  * receiver wants.
2186                                  */
2187                                 if (cmp_psn(qp->s_psn, psn) <= 0)
2188                                         reset_psn(qp, psn + 1);
2189                         }
2190                 } else {
2191                         /* No more acks - kill all timers */
2192                         rvt_stop_rc_timers(qp);
2193                         if (cmp_psn(qp->s_psn, psn) <= 0) {
2194                                 qp->s_state = OP(SEND_LAST);
2195                                 qp->s_psn = psn + 1;
2196                         }
2197                 }
2198                 if (qp->s_flags & RVT_S_WAIT_ACK) {
2199                         qp->s_flags &= ~RVT_S_WAIT_ACK;
2200                         hfi1_schedule_send(qp);
2201                 }
2202                 rvt_get_credit(qp, aeth);
2203                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
2204                 qp->s_retry = qp->s_retry_cnt;
2205                 /*
2206                  * If the current request is a TID RDMA WRITE request and the
2207                  * response is not a TID RDMA WRITE RESP packet, s_last_psn
2208                  * can't be advanced.
2209                  */
2210                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2211                     opcode != TID_OP(WRITE_RESP) &&
2212                     cmp_psn(psn, wqe->psn) >= 0)
2213                         return 1;
2214                 update_last_psn(qp, psn);
2215                 return 1;
2216
2217         case 1:         /* RNR NAK */
2218                 ibp->rvp.n_rnr_naks++;
2219                 if (qp->s_acked == qp->s_tail)
2220                         goto bail_stop;
2221                 if (qp->s_flags & RVT_S_WAIT_RNR)
2222                         goto bail_stop;
2223                 rdi = ib_to_rvt(qp->ibqp.device);
2224                 if (qp->s_rnr_retry == 0 &&
2225                     !((rdi->post_parms[wqe->wr.opcode].flags &
2226                       RVT_OPERATION_IGN_RNR_CNT) &&
2227                       qp->s_rnr_retry_cnt == 0)) {
2228                         status = IB_WC_RNR_RETRY_EXC_ERR;
2229                         goto class_b;
2230                 }
2231                 if (qp->s_rnr_retry_cnt < 7 && qp->s_rnr_retry_cnt > 0)
2232                         qp->s_rnr_retry--;
2233
2234                 /*
2235                  * The last valid PSN is the previous PSN. For TID RDMA WRITE
2236                  * request, s_last_psn should be incremented only when a TID
2237                  * RDMA WRITE RESP is received to avoid skipping lost TID RDMA
2238                  * WRITE RESP packets.
2239                  */
2240                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE) {
2241                         reset_psn(qp, qp->s_last_psn + 1);
2242                 } else {
2243                         update_last_psn(qp, psn - 1);
2244                         reset_psn(qp, psn);
2245                 }
2246
2247                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
2248                 qp->s_flags &= ~(RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_ACK);
2249                 rvt_stop_rc_timers(qp);
2250                 rvt_add_rnr_timer(qp, aeth);
2251                 return 0;
2252
2253         case 3:         /* NAK */
2254                 if (qp->s_acked == qp->s_tail)
2255                         goto bail_stop;
2256                 /* The last valid PSN is the previous PSN. */
2257                 update_last_psn(qp, psn - 1);
2258                 switch ((aeth >> IB_AETH_CREDIT_SHIFT) &
2259                         IB_AETH_CREDIT_MASK) {
2260                 case 0: /* PSN sequence error */
2261                         ibp->rvp.n_seq_naks++;
2262                         /*
2263                          * Back up to the responder's expected PSN.
2264                          * Note that we might get a NAK in the middle of an
2265                          * RDMA READ response which terminates the RDMA
2266                          * READ.
2267                          */
2268                         hfi1_restart_rc(qp, psn, 0);
2269                         hfi1_schedule_send(qp);
2270                         break;
2271
2272                 case 1: /* Invalid Request */
2273                         status = IB_WC_REM_INV_REQ_ERR;
2274                         ibp->rvp.n_other_naks++;
2275                         goto class_b;
2276
2277                 case 2: /* Remote Access Error */
2278                         status = IB_WC_REM_ACCESS_ERR;
2279                         ibp->rvp.n_other_naks++;
2280                         goto class_b;
2281
2282                 case 3: /* Remote Operation Error */
2283                         status = IB_WC_REM_OP_ERR;
2284                         ibp->rvp.n_other_naks++;
2285 class_b:
2286                         if (qp->s_last == qp->s_acked) {
2287                                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ)
2288                                         hfi1_kern_read_tid_flow_free(qp);
2289
2290                                 hfi1_trdma_send_complete(qp, wqe, status);
2291                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
2292                         }
2293                         break;
2294
2295                 default:
2296                         /* Ignore other reserved NAK error codes */
2297                         goto reserved;
2298                 }
2299                 qp->s_retry = qp->s_retry_cnt;
2300                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
2301                 goto bail_stop;
2302
2303         default:                /* 2: reserved */
2304 reserved:
2305                 /* Ignore reserved NAK codes. */
2306                 goto bail_stop;
2307         }
2308         /* cannot be reached  */
2309 bail_stop:
2310         rvt_stop_rc_timers(qp);
2311         return ret;
2312 }
2313
2314 /*
2315  * We have seen an out of sequence RDMA read middle or last packet.
2316  * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE.
2317  */
2318 static void rdma_seq_err(struct rvt_qp *qp, struct hfi1_ibport *ibp, u32 psn,
2319                          struct hfi1_ctxtdata *rcd)
2320 {
2321         struct rvt_swqe *wqe;
2322
2323         lockdep_assert_held(&qp->s_lock);
2324         /* Remove QP from retry timer */
2325         rvt_stop_rc_timers(qp);
2326
2327         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2328
2329         while (cmp_psn(psn, wqe->lpsn) > 0) {
2330                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
2331                     wqe->wr.opcode == IB_WR_TID_RDMA_READ ||
2332                     wqe->wr.opcode == IB_WR_TID_RDMA_WRITE ||
2333                     wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2334                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
2335                         break;
2336                 wqe = do_rc_completion(qp, wqe, ibp);
2337         }
2338
2339         ibp->rvp.n_rdma_seq++;
2340         qp->r_flags |= RVT_R_RDMAR_SEQ;
2341         hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
2342         if (list_empty(&qp->rspwait)) {
2343                 qp->r_flags |= RVT_R_RSP_SEND;
2344                 rvt_get_qp(qp);
2345                 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
2346         }
2347 }
2348
2349 /**
2350  * rc_rcv_resp - process an incoming RC response packet
2351  * @packet: data packet information
2352  *
2353  * This is called from hfi1_rc_rcv() to process an incoming RC response
2354  * packet for the given QP.
2355  * Called at interrupt level.
2356  */
2357 static void rc_rcv_resp(struct hfi1_packet *packet)
2358 {
2359         struct hfi1_ctxtdata *rcd = packet->rcd;
2360         void *data = packet->payload;
2361         u32 tlen = packet->tlen;
2362         struct rvt_qp *qp = packet->qp;
2363         struct hfi1_ibport *ibp;
2364         struct ib_other_headers *ohdr = packet->ohdr;
2365         struct rvt_swqe *wqe;
2366         enum ib_wc_status status;
2367         unsigned long flags;
2368         int diff;
2369         u64 val;
2370         u32 aeth;
2371         u32 psn = ib_bth_get_psn(packet->ohdr);
2372         u32 pmtu = qp->pmtu;
2373         u16 hdrsize = packet->hlen;
2374         u8 opcode = packet->opcode;
2375         u8 pad = packet->pad;
2376         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
2377
2378         spin_lock_irqsave(&qp->s_lock, flags);
2379         trace_hfi1_ack(qp, psn);
2380
2381         /* Ignore invalid responses. */
2382         if (cmp_psn(psn, READ_ONCE(qp->s_next_psn)) >= 0)
2383                 goto ack_done;
2384
2385         /* Ignore duplicate responses. */
2386         diff = cmp_psn(psn, qp->s_last_psn);
2387         if (unlikely(diff <= 0)) {
2388                 /* Update credits for "ghost" ACKs */
2389                 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
2390                         aeth = be32_to_cpu(ohdr->u.aeth);
2391                         if ((aeth >> IB_AETH_NAK_SHIFT) == 0)
2392                                 rvt_get_credit(qp, aeth);
2393                 }
2394                 goto ack_done;
2395         }
2396
2397         /*
2398          * Skip everything other than the PSN we expect, if we are waiting
2399          * for a reply to a restarted RDMA read or atomic op.
2400          */
2401         if (qp->r_flags & RVT_R_RDMAR_SEQ) {
2402                 if (cmp_psn(psn, qp->s_last_psn + 1) != 0)
2403                         goto ack_done;
2404                 qp->r_flags &= ~RVT_R_RDMAR_SEQ;
2405         }
2406
2407         if (unlikely(qp->s_acked == qp->s_tail))
2408                 goto ack_done;
2409         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2410         status = IB_WC_SUCCESS;
2411
2412         switch (opcode) {
2413         case OP(ACKNOWLEDGE):
2414         case OP(ATOMIC_ACKNOWLEDGE):
2415         case OP(RDMA_READ_RESPONSE_FIRST):
2416                 aeth = be32_to_cpu(ohdr->u.aeth);
2417                 if (opcode == OP(ATOMIC_ACKNOWLEDGE))
2418                         val = ib_u64_get(&ohdr->u.at.atomic_ack_eth);
2419                 else
2420                         val = 0;
2421                 if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) ||
2422                     opcode != OP(RDMA_READ_RESPONSE_FIRST))
2423                         goto ack_done;
2424                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2425                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2426                         goto ack_op_err;
2427                 /*
2428                  * If this is a response to a resent RDMA read, we
2429                  * have to be careful to copy the data to the right
2430                  * location.
2431                  */
2432                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
2433                                                   wqe, psn, pmtu);
2434                 goto read_middle;
2435
2436         case OP(RDMA_READ_RESPONSE_MIDDLE):
2437                 /* no AETH, no ACK */
2438                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
2439                         goto ack_seq_err;
2440                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2441                         goto ack_op_err;
2442 read_middle:
2443                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
2444                         goto ack_len_err;
2445                 if (unlikely(pmtu >= qp->s_rdma_read_len))
2446                         goto ack_len_err;
2447
2448                 /*
2449                  * We got a response so update the timeout.
2450                  * 4.096 usec. * (1 << qp->timeout)
2451                  */
2452                 rvt_mod_retry_timer(qp);
2453                 if (qp->s_flags & RVT_S_WAIT_ACK) {
2454                         qp->s_flags &= ~RVT_S_WAIT_ACK;
2455                         hfi1_schedule_send(qp);
2456                 }
2457
2458                 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
2459                         qp->s_retry = qp->s_retry_cnt;
2460
2461                 /*
2462                  * Update the RDMA receive state but do the copy w/o
2463                  * holding the locks and blocking interrupts.
2464                  */
2465                 qp->s_rdma_read_len -= pmtu;
2466                 update_last_psn(qp, psn);
2467                 spin_unlock_irqrestore(&qp->s_lock, flags);
2468                 rvt_copy_sge(qp, &qp->s_rdma_read_sge,
2469                              data, pmtu, false, false);
2470                 goto bail;
2471
2472         case OP(RDMA_READ_RESPONSE_ONLY):
2473                 aeth = be32_to_cpu(ohdr->u.aeth);
2474                 if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd))
2475                         goto ack_done;
2476                 /*
2477                  * Check that the data size is >= 0 && <= pmtu.
2478                  * Remember to account for ICRC (4).
2479                  */
2480                 if (unlikely(tlen < (hdrsize + extra_bytes)))
2481                         goto ack_len_err;
2482                 /*
2483                  * If this is a response to a resent RDMA read, we
2484                  * have to be careful to copy the data to the right
2485                  * location.
2486                  */
2487                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2488                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
2489                                                   wqe, psn, pmtu);
2490                 goto read_last;
2491
2492         case OP(RDMA_READ_RESPONSE_LAST):
2493                 /* ACKs READ req. */
2494                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
2495                         goto ack_seq_err;
2496                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2497                         goto ack_op_err;
2498                 /*
2499                  * Check that the data size is >= 1 && <= pmtu.
2500                  * Remember to account for ICRC (4).
2501                  */
2502                 if (unlikely(tlen <= (hdrsize + extra_bytes)))
2503                         goto ack_len_err;
2504 read_last:
2505                 tlen -= hdrsize + extra_bytes;
2506                 if (unlikely(tlen != qp->s_rdma_read_len))
2507                         goto ack_len_err;
2508                 aeth = be32_to_cpu(ohdr->u.aeth);
2509                 rvt_copy_sge(qp, &qp->s_rdma_read_sge,
2510                              data, tlen, false, false);
2511                 WARN_ON(qp->s_rdma_read_sge.num_sge);
2512                 (void)do_rc_ack(qp, aeth, psn,
2513                                  OP(RDMA_READ_RESPONSE_LAST), 0, rcd);
2514                 goto ack_done;
2515         }
2516
2517 ack_op_err:
2518         status = IB_WC_LOC_QP_OP_ERR;
2519         goto ack_err;
2520
2521 ack_seq_err:
2522         ibp = rcd_to_iport(rcd);
2523         rdma_seq_err(qp, ibp, psn, rcd);
2524         goto ack_done;
2525
2526 ack_len_err:
2527         status = IB_WC_LOC_LEN_ERR;
2528 ack_err:
2529         if (qp->s_last == qp->s_acked) {
2530                 rvt_send_complete(qp, wqe, status);
2531                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
2532         }
2533 ack_done:
2534         spin_unlock_irqrestore(&qp->s_lock, flags);
2535 bail:
2536         return;
2537 }
2538
2539 static inline void rc_cancel_ack(struct rvt_qp *qp)
2540 {
2541         qp->r_adefered = 0;
2542         if (list_empty(&qp->rspwait))
2543                 return;
2544         list_del_init(&qp->rspwait);
2545         qp->r_flags &= ~RVT_R_RSP_NAK;
2546         rvt_put_qp(qp);
2547 }
2548
2549 /**
2550  * rc_rcv_error - process an incoming duplicate or error RC packet
2551  * @ohdr: the other headers for this packet
2552  * @data: the packet data
2553  * @qp: the QP for this packet
2554  * @opcode: the opcode for this packet
2555  * @psn: the packet sequence number for this packet
2556  * @diff: the difference between the PSN and the expected PSN
2557  *
2558  * This is called from hfi1_rc_rcv() to process an unexpected
2559  * incoming RC packet for the given QP.
2560  * Called at interrupt level.
2561  * Return 1 if no more processing is needed; otherwise return 0 to
2562  * schedule a response to be sent.
2563  */
2564 static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
2565                                  struct rvt_qp *qp, u32 opcode, u32 psn,
2566                                  int diff, struct hfi1_ctxtdata *rcd)
2567 {
2568         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2569         struct rvt_ack_entry *e;
2570         unsigned long flags;
2571         u8 prev;
2572         u8 mra; /* most recent ACK */
2573         bool old_req;
2574
2575         trace_hfi1_rcv_error(qp, psn);
2576         if (diff > 0) {
2577                 /*
2578                  * Packet sequence error.
2579                  * A NAK will ACK earlier sends and RDMA writes.
2580                  * Don't queue the NAK if we already sent one.
2581                  */
2582                 if (!qp->r_nak_state) {
2583                         ibp->rvp.n_rc_seqnak++;
2584                         qp->r_nak_state = IB_NAK_PSN_ERROR;
2585                         /* Use the expected PSN. */
2586                         qp->r_ack_psn = qp->r_psn;
2587                         /*
2588                          * Wait to send the sequence NAK until all packets
2589                          * in the receive queue have been processed.
2590                          * Otherwise, we end up propagating congestion.
2591                          */
2592                         rc_defered_ack(rcd, qp);
2593                 }
2594                 goto done;
2595         }
2596
2597         /*
2598          * Handle a duplicate request.  Don't re-execute SEND, RDMA
2599          * write or atomic op.  Don't NAK errors, just silently drop
2600          * the duplicate request.  Note that r_sge, r_len, and
2601          * r_rcv_len may be in use so don't modify them.
2602          *
2603          * We are supposed to ACK the earliest duplicate PSN but we
2604          * can coalesce an outstanding duplicate ACK.  We have to
2605          * send the earliest so that RDMA reads can be restarted at
2606          * the requester's expected PSN.
2607          *
2608          * First, find where this duplicate PSN falls within the
2609          * ACKs previously sent.
2610          * old_req is true if there is an older response that is scheduled
2611          * to be sent before sending this one.
2612          */
2613         e = NULL;
2614         old_req = 1;
2615         ibp->rvp.n_rc_dupreq++;
2616
2617         spin_lock_irqsave(&qp->s_lock, flags);
2618
2619         e = find_prev_entry(qp, psn, &prev, &mra, &old_req);
2620
2621         switch (opcode) {
2622         case OP(RDMA_READ_REQUEST): {
2623                 struct ib_reth *reth;
2624                 u32 offset;
2625                 u32 len;
2626
2627                 /*
2628                  * If we didn't find the RDMA read request in the ack queue,
2629                  * we can ignore this request.
2630                  */
2631                 if (!e || e->opcode != OP(RDMA_READ_REQUEST))
2632                         goto unlock_done;
2633                 /* RETH comes after BTH */
2634                 reth = &ohdr->u.rc.reth;
2635                 /*
2636                  * Address range must be a subset of the original
2637                  * request and start on pmtu boundaries.
2638                  * We reuse the old ack_queue slot since the requester
2639                  * should not back up and request an earlier PSN for the
2640                  * same request.
2641                  */
2642                 offset = delta_psn(psn, e->psn) * qp->pmtu;
2643                 len = be32_to_cpu(reth->length);
2644                 if (unlikely(offset + len != e->rdma_sge.sge_length))
2645                         goto unlock_done;
2646                 if (e->rdma_sge.mr) {
2647                         rvt_put_mr(e->rdma_sge.mr);
2648                         e->rdma_sge.mr = NULL;
2649                 }
2650                 if (len != 0) {
2651                         u32 rkey = be32_to_cpu(reth->rkey);
2652                         u64 vaddr = get_ib_reth_vaddr(reth);
2653                         int ok;
2654
2655                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
2656                                          IB_ACCESS_REMOTE_READ);
2657                         if (unlikely(!ok))
2658                                 goto unlock_done;
2659                 } else {
2660                         e->rdma_sge.vaddr = NULL;
2661                         e->rdma_sge.length = 0;
2662                         e->rdma_sge.sge_length = 0;
2663                 }
2664                 e->psn = psn;
2665                 if (old_req)
2666                         goto unlock_done;
2667                 if (qp->s_acked_ack_queue == qp->s_tail_ack_queue)
2668                         qp->s_acked_ack_queue = prev;
2669                 qp->s_tail_ack_queue = prev;
2670                 break;
2671         }
2672
2673         case OP(COMPARE_SWAP):
2674         case OP(FETCH_ADD): {
2675                 /*
2676                  * If we didn't find the atomic request in the ack queue
2677                  * or the send engine is already backed up to send an
2678                  * earlier entry, we can ignore this request.
2679                  */
2680                 if (!e || e->opcode != (u8)opcode || old_req)
2681                         goto unlock_done;
2682                 if (qp->s_tail_ack_queue == qp->s_acked_ack_queue)
2683                         qp->s_acked_ack_queue = prev;
2684                 qp->s_tail_ack_queue = prev;
2685                 break;
2686         }
2687
2688         default:
2689                 /*
2690                  * Ignore this operation if it doesn't request an ACK
2691                  * or an earlier RDMA read or atomic is going to be resent.
2692                  */
2693                 if (!(psn & IB_BTH_REQ_ACK) || old_req)
2694                         goto unlock_done;
2695                 /*
2696                  * Resend the most recent ACK if this request is
2697                  * after all the previous RDMA reads and atomics.
2698                  */
2699                 if (mra == qp->r_head_ack_queue) {
2700                         spin_unlock_irqrestore(&qp->s_lock, flags);
2701                         qp->r_nak_state = 0;
2702                         qp->r_ack_psn = qp->r_psn - 1;
2703                         goto send_ack;
2704                 }
2705
2706                 /*
2707                  * Resend the RDMA read or atomic op which
2708                  * ACKs this duplicate request.
2709                  */
2710                 if (qp->s_tail_ack_queue == qp->s_acked_ack_queue)
2711                         qp->s_acked_ack_queue = mra;
2712                 qp->s_tail_ack_queue = mra;
2713                 break;
2714         }
2715         qp->s_ack_state = OP(ACKNOWLEDGE);
2716         qp->s_flags |= RVT_S_RESP_PENDING;
2717         qp->r_nak_state = 0;
2718         hfi1_schedule_send(qp);
2719
2720 unlock_done:
2721         spin_unlock_irqrestore(&qp->s_lock, flags);
2722 done:
2723         return 1;
2724
2725 send_ack:
2726         return 0;
2727 }
2728
2729 static void log_cca_event(struct hfi1_pportdata *ppd, u8 sl, u32 rlid,
2730                           u32 lqpn, u32 rqpn, u8 svc_type)
2731 {
2732         struct opa_hfi1_cong_log_event_internal *cc_event;
2733         unsigned long flags;
2734
2735         if (sl >= OPA_MAX_SLS)
2736                 return;
2737
2738         spin_lock_irqsave(&ppd->cc_log_lock, flags);
2739
2740         ppd->threshold_cong_event_map[sl / 8] |= 1 << (sl % 8);
2741         ppd->threshold_event_counter++;
2742
2743         cc_event = &ppd->cc_events[ppd->cc_log_idx++];
2744         if (ppd->cc_log_idx == OPA_CONG_LOG_ELEMS)
2745                 ppd->cc_log_idx = 0;
2746         cc_event->lqpn = lqpn & RVT_QPN_MASK;
2747         cc_event->rqpn = rqpn & RVT_QPN_MASK;
2748         cc_event->sl = sl;
2749         cc_event->svc_type = svc_type;
2750         cc_event->rlid = rlid;
2751         /* keep timestamp in units of 1.024 usec */
2752         cc_event->timestamp = ktime_get_ns() / 1024;
2753
2754         spin_unlock_irqrestore(&ppd->cc_log_lock, flags);
2755 }
2756
2757 void process_becn(struct hfi1_pportdata *ppd, u8 sl, u32 rlid, u32 lqpn,
2758                   u32 rqpn, u8 svc_type)
2759 {
2760         struct cca_timer *cca_timer;
2761         u16 ccti, ccti_incr, ccti_timer, ccti_limit;
2762         u8 trigger_threshold;
2763         struct cc_state *cc_state;
2764         unsigned long flags;
2765
2766         if (sl >= OPA_MAX_SLS)
2767                 return;
2768
2769         cc_state = get_cc_state(ppd);
2770
2771         if (!cc_state)
2772                 return;
2773
2774         /*
2775          * 1) increase CCTI (for this SL)
2776          * 2) select IPG (i.e., call set_link_ipg())
2777          * 3) start timer
2778          */
2779         ccti_limit = cc_state->cct.ccti_limit;
2780         ccti_incr = cc_state->cong_setting.entries[sl].ccti_increase;
2781         ccti_timer = cc_state->cong_setting.entries[sl].ccti_timer;
2782         trigger_threshold =
2783                 cc_state->cong_setting.entries[sl].trigger_threshold;
2784
2785         spin_lock_irqsave(&ppd->cca_timer_lock, flags);
2786
2787         cca_timer = &ppd->cca_timer[sl];
2788         if (cca_timer->ccti < ccti_limit) {
2789                 if (cca_timer->ccti + ccti_incr <= ccti_limit)
2790                         cca_timer->ccti += ccti_incr;
2791                 else
2792                         cca_timer->ccti = ccti_limit;
2793                 set_link_ipg(ppd);
2794         }
2795
2796         ccti = cca_timer->ccti;
2797
2798         if (!hrtimer_active(&cca_timer->hrtimer)) {
2799                 /* ccti_timer is in units of 1.024 usec */
2800                 unsigned long nsec = 1024 * ccti_timer;
2801
2802                 hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec),
2803                               HRTIMER_MODE_REL_PINNED);
2804         }
2805
2806         spin_unlock_irqrestore(&ppd->cca_timer_lock, flags);
2807
2808         if ((trigger_threshold != 0) && (ccti >= trigger_threshold))
2809                 log_cca_event(ppd, sl, rlid, lqpn, rqpn, svc_type);
2810 }
2811
2812 /**
2813  * hfi1_rc_rcv - process an incoming RC packet
2814  * @packet: data packet information
2815  *
2816  * This is called from qp_rcv() to process an incoming RC packet
2817  * for the given QP.
2818  * May be called at interrupt level.
2819  */
2820 void hfi1_rc_rcv(struct hfi1_packet *packet)
2821 {
2822         struct hfi1_ctxtdata *rcd = packet->rcd;
2823         void *data = packet->payload;
2824         u32 tlen = packet->tlen;
2825         struct rvt_qp *qp = packet->qp;
2826         struct hfi1_qp_priv *qpriv = qp->priv;
2827         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2828         struct ib_other_headers *ohdr = packet->ohdr;
2829         u32 opcode = packet->opcode;
2830         u32 hdrsize = packet->hlen;
2831         u32 psn = ib_bth_get_psn(packet->ohdr);
2832         u32 pad = packet->pad;
2833         struct ib_wc wc;
2834         u32 pmtu = qp->pmtu;
2835         int diff;
2836         struct ib_reth *reth;
2837         unsigned long flags;
2838         int ret;
2839         bool copy_last = false, fecn;
2840         u32 rkey;
2841         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
2842
2843         lockdep_assert_held(&qp->r_lock);
2844
2845         if (hfi1_ruc_check_hdr(ibp, packet))
2846                 return;
2847
2848         fecn = process_ecn(qp, packet);
2849         opfn_trigger_conn_request(qp, be32_to_cpu(ohdr->bth[1]));
2850
2851         /*
2852          * Process responses (ACKs) before anything else.  Note that the
2853          * packet sequence number will be for something in the send work
2854          * queue rather than the expected receive packet sequence number.
2855          * In other words, this QP is the requester.
2856          */
2857         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
2858             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
2859                 rc_rcv_resp(packet);
2860                 return;
2861         }
2862
2863         /* Compute 24 bits worth of difference. */
2864         diff = delta_psn(psn, qp->r_psn);
2865         if (unlikely(diff)) {
2866                 if (rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd))
2867                         return;
2868                 goto send_ack;
2869         }
2870
2871         /* Check for opcode sequence errors. */
2872         switch (qp->r_state) {
2873         case OP(SEND_FIRST):
2874         case OP(SEND_MIDDLE):
2875                 if (opcode == OP(SEND_MIDDLE) ||
2876                     opcode == OP(SEND_LAST) ||
2877                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2878                     opcode == OP(SEND_LAST_WITH_INVALIDATE))
2879                         break;
2880                 goto nack_inv;
2881
2882         case OP(RDMA_WRITE_FIRST):
2883         case OP(RDMA_WRITE_MIDDLE):
2884                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
2885                     opcode == OP(RDMA_WRITE_LAST) ||
2886                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2887                         break;
2888                 goto nack_inv;
2889
2890         default:
2891                 if (opcode == OP(SEND_MIDDLE) ||
2892                     opcode == OP(SEND_LAST) ||
2893                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2894                     opcode == OP(SEND_LAST_WITH_INVALIDATE) ||
2895                     opcode == OP(RDMA_WRITE_MIDDLE) ||
2896                     opcode == OP(RDMA_WRITE_LAST) ||
2897                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2898                         goto nack_inv;
2899                 /*
2900                  * Note that it is up to the requester to not send a new
2901                  * RDMA read or atomic operation before receiving an ACK
2902                  * for the previous operation.
2903                  */
2904                 break;
2905         }
2906
2907         if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
2908                 rvt_comm_est(qp);
2909
2910         /* OK, process the packet. */
2911         switch (opcode) {
2912         case OP(SEND_FIRST):
2913                 ret = rvt_get_rwqe(qp, false);
2914                 if (ret < 0)
2915                         goto nack_op_err;
2916                 if (!ret)
2917                         goto rnr_nak;
2918                 qp->r_rcv_len = 0;
2919                 /* FALLTHROUGH */
2920         case OP(SEND_MIDDLE):
2921         case OP(RDMA_WRITE_MIDDLE):
2922 send_middle:
2923                 /* Check for invalid length PMTU or posted rwqe len. */
2924                 /*
2925                  * There will be no padding for 9B packet but 16B packets
2926                  * will come in with some padding since we always add
2927                  * CRC and LT bytes which will need to be flit aligned
2928                  */
2929                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
2930                         goto nack_inv;
2931                 qp->r_rcv_len += pmtu;
2932                 if (unlikely(qp->r_rcv_len > qp->r_len))
2933                         goto nack_inv;
2934                 rvt_copy_sge(qp, &qp->r_sge, data, pmtu, true, false);
2935                 break;
2936
2937         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
2938                 /* consume RWQE */
2939                 ret = rvt_get_rwqe(qp, true);
2940                 if (ret < 0)
2941                         goto nack_op_err;
2942                 if (!ret)
2943                         goto rnr_nak;
2944                 goto send_last_imm;
2945
2946         case OP(SEND_ONLY):
2947         case OP(SEND_ONLY_WITH_IMMEDIATE):
2948         case OP(SEND_ONLY_WITH_INVALIDATE):
2949                 ret = rvt_get_rwqe(qp, false);
2950                 if (ret < 0)
2951                         goto nack_op_err;
2952                 if (!ret)
2953                         goto rnr_nak;
2954                 qp->r_rcv_len = 0;
2955                 if (opcode == OP(SEND_ONLY))
2956                         goto no_immediate_data;
2957                 if (opcode == OP(SEND_ONLY_WITH_INVALIDATE))
2958                         goto send_last_inv;
2959                 /* FALLTHROUGH -- for SEND_ONLY_WITH_IMMEDIATE */
2960         case OP(SEND_LAST_WITH_IMMEDIATE):
2961 send_last_imm:
2962                 wc.ex.imm_data = ohdr->u.imm_data;
2963                 wc.wc_flags = IB_WC_WITH_IMM;
2964                 goto send_last;
2965         case OP(SEND_LAST_WITH_INVALIDATE):
2966 send_last_inv:
2967                 rkey = be32_to_cpu(ohdr->u.ieth);
2968                 if (rvt_invalidate_rkey(qp, rkey))
2969                         goto no_immediate_data;
2970                 wc.ex.invalidate_rkey = rkey;
2971                 wc.wc_flags = IB_WC_WITH_INVALIDATE;
2972                 goto send_last;
2973         case OP(RDMA_WRITE_LAST):
2974                 copy_last = rvt_is_user_qp(qp);
2975                 /* fall through */
2976         case OP(SEND_LAST):
2977 no_immediate_data:
2978                 wc.wc_flags = 0;
2979                 wc.ex.imm_data = 0;
2980 send_last:
2981                 /* Check for invalid length. */
2982                 /* LAST len should be >= 1 */
2983                 if (unlikely(tlen < (hdrsize + extra_bytes)))
2984                         goto nack_inv;
2985                 /* Don't count the CRC(and padding and LT byte for 16B). */
2986                 tlen -= (hdrsize + extra_bytes);
2987                 wc.byte_len = tlen + qp->r_rcv_len;
2988                 if (unlikely(wc.byte_len > qp->r_len))
2989                         goto nack_inv;
2990                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, copy_last);
2991                 rvt_put_ss(&qp->r_sge);
2992                 qp->r_msn++;
2993                 if (!__test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
2994                         break;
2995                 wc.wr_id = qp->r_wr_id;
2996                 wc.status = IB_WC_SUCCESS;
2997                 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
2998                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
2999                         wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
3000                 else
3001                         wc.opcode = IB_WC_RECV;
3002                 wc.qp = &qp->ibqp;
3003                 wc.src_qp = qp->remote_qpn;
3004                 wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
3005                 /*
3006                  * It seems that IB mandates the presence of an SL in a
3007                  * work completion only for the UD transport (see section
3008                  * 11.4.2 of IBTA Vol. 1).
3009                  *
3010                  * However, the way the SL is chosen below is consistent
3011                  * with the way that IB/qib works and is trying avoid
3012                  * introducing incompatibilities.
3013                  *
3014                  * See also OPA Vol. 1, section 9.7.6, and table 9-17.
3015                  */
3016                 wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
3017                 /* zero fields that are N/A */
3018                 wc.vendor_err = 0;
3019                 wc.pkey_index = 0;
3020                 wc.dlid_path_bits = 0;
3021                 wc.port_num = 0;
3022                 /* Signal completion event if the solicited bit is set. */
3023                 rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
3024                              ib_bth_is_solicited(ohdr));
3025                 break;
3026
3027         case OP(RDMA_WRITE_ONLY):
3028                 copy_last = rvt_is_user_qp(qp);
3029                 /* fall through */
3030         case OP(RDMA_WRITE_FIRST):
3031         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
3032                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
3033                         goto nack_inv;
3034                 /* consume RWQE */
3035                 reth = &ohdr->u.rc.reth;
3036                 qp->r_len = be32_to_cpu(reth->length);
3037                 qp->r_rcv_len = 0;
3038                 qp->r_sge.sg_list = NULL;
3039                 if (qp->r_len != 0) {
3040                         u32 rkey = be32_to_cpu(reth->rkey);
3041                         u64 vaddr = get_ib_reth_vaddr(reth);
3042                         int ok;
3043
3044                         /* Check rkey & NAK */
3045                         ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr,
3046                                          rkey, IB_ACCESS_REMOTE_WRITE);
3047                         if (unlikely(!ok))
3048                                 goto nack_acc;
3049                         qp->r_sge.num_sge = 1;
3050                 } else {
3051                         qp->r_sge.num_sge = 0;
3052                         qp->r_sge.sge.mr = NULL;
3053                         qp->r_sge.sge.vaddr = NULL;
3054                         qp->r_sge.sge.length = 0;
3055                         qp->r_sge.sge.sge_length = 0;
3056                 }
3057                 if (opcode == OP(RDMA_WRITE_FIRST))
3058                         goto send_middle;
3059                 else if (opcode == OP(RDMA_WRITE_ONLY))
3060                         goto no_immediate_data;
3061                 ret = rvt_get_rwqe(qp, true);
3062                 if (ret < 0)
3063                         goto nack_op_err;
3064                 if (!ret) {
3065                         /* peer will send again */
3066                         rvt_put_ss(&qp->r_sge);
3067                         goto rnr_nak;
3068                 }
3069                 wc.ex.imm_data = ohdr->u.rc.imm_data;
3070                 wc.wc_flags = IB_WC_WITH_IMM;
3071                 goto send_last;
3072
3073         case OP(RDMA_READ_REQUEST): {
3074                 struct rvt_ack_entry *e;
3075                 u32 len;
3076                 u8 next;
3077
3078                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
3079                         goto nack_inv;
3080                 next = qp->r_head_ack_queue + 1;
3081                 /* s_ack_queue is size rvt_size_atomic()+1 so use > not >= */
3082                 if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
3083                         next = 0;
3084                 spin_lock_irqsave(&qp->s_lock, flags);
3085                 if (unlikely(next == qp->s_acked_ack_queue)) {
3086                         if (!qp->s_ack_queue[next].sent)
3087                                 goto nack_inv_unlck;
3088                         update_ack_queue(qp, next);
3089                 }
3090                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
3091                 if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
3092                         rvt_put_mr(e->rdma_sge.mr);
3093                         e->rdma_sge.mr = NULL;
3094                 }
3095                 reth = &ohdr->u.rc.reth;
3096                 len = be32_to_cpu(reth->length);
3097                 if (len) {
3098                         u32 rkey = be32_to_cpu(reth->rkey);
3099                         u64 vaddr = get_ib_reth_vaddr(reth);
3100                         int ok;
3101
3102                         /* Check rkey & NAK */
3103                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr,
3104                                          rkey, IB_ACCESS_REMOTE_READ);
3105                         if (unlikely(!ok))
3106                                 goto nack_acc_unlck;
3107                         /*
3108                          * Update the next expected PSN.  We add 1 later
3109                          * below, so only add the remainder here.
3110                          */
3111                         qp->r_psn += rvt_div_mtu(qp, len - 1);
3112                 } else {
3113                         e->rdma_sge.mr = NULL;
3114                         e->rdma_sge.vaddr = NULL;
3115                         e->rdma_sge.length = 0;
3116                         e->rdma_sge.sge_length = 0;
3117                 }
3118                 e->opcode = opcode;
3119                 e->sent = 0;
3120                 e->psn = psn;
3121                 e->lpsn = qp->r_psn;
3122                 /*
3123                  * We need to increment the MSN here instead of when we
3124                  * finish sending the result since a duplicate request would
3125                  * increment it more than once.
3126                  */
3127                 qp->r_msn++;
3128                 qp->r_psn++;
3129                 qp->r_state = opcode;
3130                 qp->r_nak_state = 0;
3131                 qp->r_head_ack_queue = next;
3132                 qpriv->r_tid_alloc = qp->r_head_ack_queue;
3133
3134                 /* Schedule the send engine. */
3135                 qp->s_flags |= RVT_S_RESP_PENDING;
3136                 if (fecn)
3137                         qp->s_flags |= RVT_S_ECN;
3138                 hfi1_schedule_send(qp);
3139
3140                 spin_unlock_irqrestore(&qp->s_lock, flags);
3141                 return;
3142         }
3143
3144         case OP(COMPARE_SWAP):
3145         case OP(FETCH_ADD): {
3146                 struct ib_atomic_eth *ateth = &ohdr->u.atomic_eth;
3147                 u64 vaddr = get_ib_ateth_vaddr(ateth);
3148                 bool opfn = opcode == OP(COMPARE_SWAP) &&
3149                         vaddr == HFI1_VERBS_E_ATOMIC_VADDR;
3150                 struct rvt_ack_entry *e;
3151                 atomic64_t *maddr;
3152                 u64 sdata;
3153                 u32 rkey;
3154                 u8 next;
3155
3156                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC) &&
3157                              !opfn))
3158                         goto nack_inv;
3159                 next = qp->r_head_ack_queue + 1;
3160                 if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
3161                         next = 0;
3162                 spin_lock_irqsave(&qp->s_lock, flags);
3163                 if (unlikely(next == qp->s_acked_ack_queue)) {
3164                         if (!qp->s_ack_queue[next].sent)
3165                                 goto nack_inv_unlck;
3166                         update_ack_queue(qp, next);
3167                 }
3168                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
3169                 if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
3170                         rvt_put_mr(e->rdma_sge.mr);
3171                         e->rdma_sge.mr = NULL;
3172                 }
3173                 /* Process OPFN special virtual address */
3174                 if (opfn) {
3175                         opfn_conn_response(qp, e, ateth);
3176                         goto ack;
3177                 }
3178                 if (unlikely(vaddr & (sizeof(u64) - 1)))
3179                         goto nack_inv_unlck;
3180                 rkey = be32_to_cpu(ateth->rkey);
3181                 /* Check rkey & NAK */
3182                 if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
3183                                           vaddr, rkey,
3184                                           IB_ACCESS_REMOTE_ATOMIC)))
3185                         goto nack_acc_unlck;
3186                 /* Perform atomic OP and save result. */
3187                 maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
3188                 sdata = get_ib_ateth_swap(ateth);
3189                 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
3190                         (u64)atomic64_add_return(sdata, maddr) - sdata :
3191                         (u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
3192                                       get_ib_ateth_compare(ateth),
3193                                       sdata);
3194                 rvt_put_mr(qp->r_sge.sge.mr);
3195                 qp->r_sge.num_sge = 0;
3196 ack:
3197                 e->opcode = opcode;
3198                 e->sent = 0;
3199                 e->psn = psn;
3200                 e->lpsn = psn;
3201                 qp->r_msn++;
3202                 qp->r_psn++;
3203                 qp->r_state = opcode;
3204                 qp->r_nak_state = 0;
3205                 qp->r_head_ack_queue = next;
3206                 qpriv->r_tid_alloc = qp->r_head_ack_queue;
3207
3208                 /* Schedule the send engine. */
3209                 qp->s_flags |= RVT_S_RESP_PENDING;
3210                 if (fecn)
3211                         qp->s_flags |= RVT_S_ECN;
3212                 hfi1_schedule_send(qp);
3213
3214                 spin_unlock_irqrestore(&qp->s_lock, flags);
3215                 return;
3216         }
3217
3218         default:
3219                 /* NAK unknown opcodes. */
3220                 goto nack_inv;
3221         }
3222         qp->r_psn++;
3223         qp->r_state = opcode;
3224         qp->r_ack_psn = psn;
3225         qp->r_nak_state = 0;
3226         /* Send an ACK if requested or required. */
3227         if (psn & IB_BTH_REQ_ACK || fecn) {
3228                 if (packet->numpkt == 0 || fecn ||
3229                     qp->r_adefered >= HFI1_PSN_CREDIT) {
3230                         rc_cancel_ack(qp);
3231                         goto send_ack;
3232                 }
3233                 qp->r_adefered++;
3234                 rc_defered_ack(rcd, qp);
3235         }
3236         return;
3237
3238 rnr_nak:
3239         qp->r_nak_state = qp->r_min_rnr_timer | IB_RNR_NAK;
3240         qp->r_ack_psn = qp->r_psn;
3241         /* Queue RNR NAK for later */
3242         rc_defered_ack(rcd, qp);
3243         return;
3244
3245 nack_op_err:
3246         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
3247         qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
3248         qp->r_ack_psn = qp->r_psn;
3249         /* Queue NAK for later */
3250         rc_defered_ack(rcd, qp);
3251         return;
3252
3253 nack_inv_unlck:
3254         spin_unlock_irqrestore(&qp->s_lock, flags);
3255 nack_inv:
3256         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
3257         qp->r_nak_state = IB_NAK_INVALID_REQUEST;
3258         qp->r_ack_psn = qp->r_psn;
3259         /* Queue NAK for later */
3260         rc_defered_ack(rcd, qp);
3261         return;
3262
3263 nack_acc_unlck:
3264         spin_unlock_irqrestore(&qp->s_lock, flags);
3265 nack_acc:
3266         rvt_rc_error(qp, IB_WC_LOC_PROT_ERR);
3267         qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
3268         qp->r_ack_psn = qp->r_psn;
3269 send_ack:
3270         hfi1_send_rc_ack(packet, fecn);
3271 }
3272
3273 void hfi1_rc_hdrerr(
3274         struct hfi1_ctxtdata *rcd,
3275         struct hfi1_packet *packet,
3276         struct rvt_qp *qp)
3277 {
3278         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
3279         int diff;
3280         u32 opcode;
3281         u32 psn;
3282
3283         if (hfi1_ruc_check_hdr(ibp, packet))
3284                 return;
3285
3286         psn = ib_bth_get_psn(packet->ohdr);
3287         opcode = ib_bth_get_opcode(packet->ohdr);
3288
3289         /* Only deal with RDMA Writes for now */
3290         if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {
3291                 diff = delta_psn(psn, qp->r_psn);
3292                 if (!qp->r_nak_state && diff >= 0) {
3293                         ibp->rvp.n_rc_seqnak++;
3294                         qp->r_nak_state = IB_NAK_PSN_ERROR;
3295                         /* Use the expected PSN. */
3296                         qp->r_ack_psn = qp->r_psn;
3297                         /*
3298                          * Wait to send the sequence
3299                          * NAK until all packets
3300                          * in the receive queue have
3301                          * been processed.
3302                          * Otherwise, we end up
3303                          * propagating congestion.
3304                          */
3305                         rc_defered_ack(rcd, qp);
3306                 } /* Out of sequence NAK */
3307         } /* QP Request NAKs */
3308 }