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                 release_rdma_sge_mr(e);
 144                 /* FALLTHROUGH */
 145         case OP(ATOMIC_ACKNOWLEDGE):
 146                 /*
 147                  * We can increment the tail pointer now that the last
 148                  * response has been sent instead of only being
 149                  * constructed.
 150                  */
 151                 if (++next > rvt_size_atomic(&dev->rdi))
 152                         next = 0;
 153                 /*
 154                  * Only advance the s_acked_ack_queue pointer if there
 155                  * have been no TID RDMA requests.
 156                  */
 157                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 158                 if (e->opcode != TID_OP(WRITE_REQ) &&
 159                     qp->s_acked_ack_queue == qp->s_tail_ack_queue)
 160                         qp->s_acked_ack_queue = next;
 161                 qp->s_tail_ack_queue = next;
 162                 trace_hfi1_rsp_make_rc_ack(qp, e->psn);
 163                 /* FALLTHROUGH */
 164         case OP(SEND_ONLY):
 165         case OP(ACKNOWLEDGE):
 166                 /* Check for no next entry in the queue. */
 167                 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
 168                         if (qp->s_flags & RVT_S_ACK_PENDING)
 169                                 goto normal;
 170                         goto bail;
 171                 }
 172
 173                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 174                 /* Check for tid write fence */
 175                 if ((qpriv->s_flags & HFI1_R_TID_WAIT_INTERLCK) ||
 176                     hfi1_tid_rdma_ack_interlock(qp, e)) {
 177                         iowait_set_flag(&qpriv->s_iowait, IOWAIT_PENDING_IB);
 178                         goto bail;
 179                 }
 180                 if (e->opcode == OP(RDMA_READ_REQUEST)) {
 181                         /*
 182                          * If a RDMA read response is being resent and
 183                          * we haven't seen the duplicate request yet,
 184                          * then stop sending the remaining responses the
 185                          * responder has seen until the requester re-sends it.
 186                          */
 187                         len = e->rdma_sge.sge_length;
 188                         if (len && !e->rdma_sge.mr) {
 189                                 if (qp->s_acked_ack_queue ==
 190                                     qp->s_tail_ack_queue)
 191                                         qp->s_acked_ack_queue =
 192                                                 qp->r_head_ack_queue;
 193                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
 194                                 goto bail;
 195                         }
 196                         /* Copy SGE state in case we need to resend */
 197                         ps->s_txreq->mr = e->rdma_sge.mr;
 198                         if (ps->s_txreq->mr)
 199                                 rvt_get_mr(ps->s_txreq->mr);
 200                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
 201                         qp->s_ack_rdma_sge.num_sge = 1;
 202                         ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 203                         if (len > pmtu) {
 204                                 len = pmtu;
 205                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
 206                         } else {
 207                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
 208                                 e->sent = 1;
 209                         }
 210                         ohdr->u.aeth = rvt_compute_aeth(qp);
 211                         hwords++;
 212                         qp->s_ack_rdma_psn = e->psn;
 213                         bth2 = mask_psn(qp->s_ack_rdma_psn++);
 214                 } else if (e->opcode == TID_OP(WRITE_REQ)) {
 215                         /*
 216                          * If a TID RDMA WRITE RESP is being resent, we have to
 217                          * wait for the actual request. All requests that are to
 218                          * be resent will have their state set to
 219                          * TID_REQUEST_RESEND. When the new request arrives, the
 220                          * state will be changed to TID_REQUEST_RESEND_ACTIVE.
 221                          */
 222                         req = ack_to_tid_req(e);
 223                         if (req->state == TID_REQUEST_RESEND ||
 224                             req->state == TID_REQUEST_INIT_RESEND)
 225                                 goto bail;
 226                         qp->s_ack_state = TID_OP(WRITE_RESP);
 227                         qp->s_ack_rdma_psn = mask_psn(e->psn + req->cur_seg);
 228                         goto write_resp;
 229                 } else if (e->opcode == TID_OP(READ_REQ)) {
 230                         /*
 231                          * If a TID RDMA read response is being resent and
 232                          * we haven't seen the duplicate request yet,
 233                          * then stop sending the remaining responses the
 234                          * responder has seen until the requester re-sends it.
 235                          */
 236                         len = e->rdma_sge.sge_length;
 237                         if (len && !e->rdma_sge.mr) {
 238                                 if (qp->s_acked_ack_queue ==
 239                                     qp->s_tail_ack_queue)
 240                                         qp->s_acked_ack_queue =
 241                                                 qp->r_head_ack_queue;
 242                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
 243                                 goto bail;
 244                         }
 245                         /* Copy SGE state in case we need to resend */
 246                         ps->s_txreq->mr = e->rdma_sge.mr;
 247                         if (ps->s_txreq->mr)
 248                                 rvt_get_mr(ps->s_txreq->mr);
 249                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
 250                         qp->s_ack_rdma_sge.num_sge = 1;
 251                         qp->s_ack_state = TID_OP(READ_RESP);
 252                         goto read_resp;
 253                 } else {
 254                         /* COMPARE_SWAP or FETCH_ADD */
 255                         ps->s_txreq->ss = NULL;
 256                         len = 0;
 257                         qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
 258                         ohdr->u.at.aeth = rvt_compute_aeth(qp);
 259                         ib_u64_put(e->atomic_data, &ohdr->u.at.atomic_ack_eth);
 260                         hwords += sizeof(ohdr->u.at) / sizeof(u32);
 261                         bth2 = mask_psn(e->psn);
 262                         e->sent = 1;
 263                 }
 264                 trace_hfi1_tid_write_rsp_make_rc_ack(qp);
 265                 bth0 = qp->s_ack_state << 24;
 266                 break;
 267
 268         case OP(RDMA_READ_RESPONSE_FIRST):
 269                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
 270                 /* FALLTHROUGH */
 271         case OP(RDMA_READ_RESPONSE_MIDDLE):
 272                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 273                 ps->s_txreq->mr = qp->s_ack_rdma_sge.sge.mr;
 274                 if (ps->s_txreq->mr)
 275                         rvt_get_mr(ps->s_txreq->mr);
 276                 len = qp->s_ack_rdma_sge.sge.sge_length;
 277                 if (len > pmtu) {
 278                         len = pmtu;
 279                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 280                 } else {
 281                         ohdr->u.aeth = rvt_compute_aeth(qp);
 282                         hwords++;
 283                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
 284                         e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 285                         e->sent = 1;
 286                 }
 287                 bth0 = qp->s_ack_state << 24;
 288                 bth2 = mask_psn(qp->s_ack_rdma_psn++);
 289                 break;
 290
 291         case TID_OP(WRITE_RESP):
 292 write_resp:
 293                 /*
 294                  * 1. Check if RVT_S_ACK_PENDING is set. If yes,
 295                  *    goto normal.
 296                  * 2. Attempt to allocate TID resources.
 297                  * 3. Remove RVT_S_RESP_PENDING flags from s_flags
 298                  * 4. If resources not available:
 299                  *    4.1 Set RVT_S_WAIT_TID_SPACE
 300                  *    4.2 Queue QP on RCD TID queue
 301                  *    4.3 Put QP on iowait list.
 302                  *    4.4 Build IB RNR NAK with appropriate timeout value
 303                  *    4.5 Return indication progress made.
 304                  * 5. If resources are available:
 305                  *    5.1 Program HW flow CSRs
 306                  *    5.2 Build TID RDMA WRITE RESP packet
 307                  *    5.3 If more resources needed, do 2.1 - 2.3.
 308                  *    5.4 Wake up next QP on RCD TID queue.
 309                  *    5.5 Return indication progress made.
 310                  */
 311
 312                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 313                 req = ack_to_tid_req(e);
 314
 315                 /*
 316                  * Send scheduled RNR NAK's. RNR NAK's need to be sent at
 317                  * segment boundaries, not at request boundaries. Don't change
 318                  * s_ack_state because we are still in the middle of a request
 319                  */
 320                 if (qpriv->rnr_nak_state == TID_RNR_NAK_SEND &&
 321                     qp->s_tail_ack_queue == qpriv->r_tid_alloc &&
 322                     req->cur_seg == req->alloc_seg) {
 323                         qpriv->rnr_nak_state = TID_RNR_NAK_SENT;
 324                         goto normal_no_state;
 325                 }
 326
 327                 bth2 = mask_psn(qp->s_ack_rdma_psn);
 328                 hdrlen = hfi1_build_tid_rdma_write_resp(qp, e, ohdr, &bth1,
 329                                                         bth2, &len,
 330                                                         &ps->s_txreq->ss);
 331                 if (!hdrlen)
 332                         return 0;
 333
 334                 hwords += hdrlen;
 335                 bth0 = qp->s_ack_state << 24;
 336                 qp->s_ack_rdma_psn++;
 337                 trace_hfi1_tid_req_make_rc_ack_write(qp, 0, e->opcode, e->psn,
 338                                                      e->lpsn, req);
 339                 if (req->cur_seg != req->total_segs)
 340                         break;
 341
 342                 e->sent = 1;
 343                 /* Do not free e->rdma_sge until all data are received */
 344                 qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
 345                 break;
 346
 347         case TID_OP(READ_RESP):
 348 read_resp:
 349                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 350                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 351                 delta = hfi1_build_tid_rdma_read_resp(qp, e, ohdr, &bth0,
 352                                                       &bth1, &bth2, &len,
 353                                                       &last_pkt);
 354                 if (delta == 0)
 355                         goto error_qp;
 356                 hwords += delta;
 357                 if (last_pkt) {
 358                         e->sent = 1;
 359                         /*
 360                          * Increment qp->s_tail_ack_queue through s_ack_state
 361                          * transition.
 362                          */
 363                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
 364                 }
 365                 break;
 366         case TID_OP(READ_REQ):
 367                 goto bail;
 368
 369         default:
 370 normal:
 371                 /*
 372                  * Send a regular ACK.
 373                  * Set the s_ack_state so we wait until after sending
 374                  * the ACK before setting s_ack_state to ACKNOWLEDGE
 375                  * (see above).
 376                  */
 377                 qp->s_ack_state = OP(SEND_ONLY);
 378 normal_no_state:
 379                 if (qp->s_nak_state)
 380                         ohdr->u.aeth =
 381                                 cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
 382                                             (qp->s_nak_state <<
 383                                              IB_AETH_CREDIT_SHIFT));
 384                 else
 385                         ohdr->u.aeth = rvt_compute_aeth(qp);
 386                 hwords++;
 387                 len = 0;
 388                 bth0 = OP(ACKNOWLEDGE) << 24;
 389                 bth2 = mask_psn(qp->s_ack_psn);
 390                 qp->s_flags &= ~RVT_S_ACK_PENDING;
 391                 ps->s_txreq->txreq.flags |= SDMA_TXREQ_F_VIP;
 392                 ps->s_txreq->ss = NULL;
 393         }
 394         qp->s_rdma_ack_cnt++;
 395         ps->s_txreq->sde = qpriv->s_sde;
 396         ps->s_txreq->s_cur_size = len;
 397         ps->s_txreq->hdr_dwords = hwords;
 398         hfi1_make_ruc_header(qp, ohdr, bth0, bth1, bth2, middle, ps);
 399         return 1;
 400 error_qp:
 401         spin_unlock_irqrestore(&qp->s_lock, ps->flags);
 402         spin_lock_irqsave(&qp->r_lock, ps->flags);
 403         spin_lock(&qp->s_lock);
 404         rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
 405         spin_unlock(&qp->s_lock);
 406         spin_unlock_irqrestore(&qp->r_lock, ps->flags);
 407         spin_lock_irqsave(&qp->s_lock, ps->flags);
 408 bail:
 409         qp->s_ack_state = OP(ACKNOWLEDGE);
 410         /*
 411          * Ensure s_rdma_ack_cnt changes are committed prior to resetting
 412          * RVT_S_RESP_PENDING
 413          */
 414         smp_wmb();
 415         qp->s_flags &= ~(RVT_S_RESP_PENDING
 416                                 | RVT_S_ACK_PENDING
 417                                 | HFI1_S_AHG_VALID);
 418         return 0;
 419 }
 420
 421 /**
 422  * hfi1_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
 423  * @qp: a pointer to the QP
 424  *
 425  * Assumes s_lock is held.
 426  *
 427  * Return 1 if constructed; otherwise, return 0.
 428  */
 429 int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
 430 {
 431         struct hfi1_qp_priv *priv = qp->priv;
 432         struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
 433         struct ib_other_headers *ohdr;
 434         struct rvt_sge_state *ss = NULL;
 435         struct rvt_swqe *wqe;
 436         struct hfi1_swqe_priv *wpriv;
 437         struct tid_rdma_request *req = NULL;
 438         /* header size in 32-bit words LRH+BTH = (8+12)/4. */
 439         u32 hwords = 5;
 440         u32 len = 0;
 441         u32 bth0 = 0, bth2 = 0;
 442         u32 bth1 = qp->remote_qpn | (HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT);
 443         u32 pmtu = qp->pmtu;
 444         char newreq;
 445         int middle = 0;
 446         int delta;
 447         struct tid_rdma_flow *flow = NULL;
 448         struct tid_rdma_params *remote;
 449
 450         trace_hfi1_sender_make_rc_req(qp);
 451         lockdep_assert_held(&qp->s_lock);
 452         ps->s_txreq = get_txreq(ps->dev, qp);
 453         if (!ps->s_txreq)
 454                 goto bail_no_tx;
 455
 456         if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
 457                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
 458                 hwords = 5;
 459                 if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
 460                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
 461                 else
 462                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
 463         } else {
 464                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
 465                 hwords = 7;
 466                 if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
 467                     (hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))))
 468                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
 469                 else
 470                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
 471         }
 472
 473         /* Sending responses has higher priority over sending requests. */
 474         if ((qp->s_flags & RVT_S_RESP_PENDING) &&
 475             make_rc_ack(dev, qp, ohdr, ps))
 476                 return 1;
 477
 478         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
 479                 if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
 480                         goto bail;
 481                 /* We are in the error state, flush the work request. */
 482                 if (qp->s_last == READ_ONCE(qp->s_head))
 483                         goto bail;
 484                 /* If DMAs are in progress, we can't flush immediately. */
 485                 if (iowait_sdma_pending(&priv->s_iowait)) {
 486                         qp->s_flags |= RVT_S_WAIT_DMA;
 487                         goto bail;
 488                 }
 489                 clear_ahg(qp);
 490                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
 491                 hfi1_trdma_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
 492                                          IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
 493                 /* will get called again */
 494                 goto done_free_tx;
 495         }
 496
 497         if (qp->s_flags & (RVT_S_WAIT_RNR | RVT_S_WAIT_ACK | HFI1_S_WAIT_HALT))
 498                 goto bail;
 499
 500         if (cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) {
 501                 if (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) {
 502                         qp->s_flags |= RVT_S_WAIT_PSN;
 503                         goto bail;
 504                 }
 505                 qp->s_sending_psn = qp->s_psn;
 506                 qp->s_sending_hpsn = qp->s_psn - 1;
 507         }
 508
 509         /* Send a request. */
 510         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
 511 check_s_state:
 512         switch (qp->s_state) {
 513         default:
 514                 if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK))
 515                         goto bail;
 516                 /*
 517                  * Resend an old request or start a new one.
 518                  *
 519                  * We keep track of the current SWQE so that
 520                  * we don't reset the "furthest progress" state
 521                  * if we need to back up.
 522                  */
 523                 newreq = 0;
 524                 if (qp->s_cur == qp->s_tail) {
 525                         /* Check if send work queue is empty. */
 526                         if (qp->s_tail == READ_ONCE(qp->s_head)) {
 527                                 clear_ahg(qp);
 528                                 goto bail;
 529                         }
 530                         /*
 531                          * If a fence is requested, wait for previous
 532                          * RDMA read and atomic operations to finish.
 533                          * However, there is no need to guard against
 534                          * TID RDMA READ after TID RDMA READ.
 535                          */
 536                         if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
 537                             qp->s_num_rd_atomic &&
 538                             (wqe->wr.opcode != IB_WR_TID_RDMA_READ ||
 539                              priv->pending_tid_r_segs < qp->s_num_rd_atomic)) {
 540                                 qp->s_flags |= RVT_S_WAIT_FENCE;
 541                                 goto bail;
 542                         }
 543                         /*
 544                          * Local operations are processed immediately
 545                          * after all prior requests have completed
 546                          */
 547                         if (wqe->wr.opcode == IB_WR_REG_MR ||
 548                             wqe->wr.opcode == IB_WR_LOCAL_INV) {
 549                                 int local_ops = 0;
 550                                 int err = 0;
 551
 552                                 if (qp->s_last != qp->s_cur)
 553                                         goto bail;
 554                                 if (++qp->s_cur == qp->s_size)
 555                                         qp->s_cur = 0;
 556                                 if (++qp->s_tail == qp->s_size)
 557                                         qp->s_tail = 0;
 558                                 if (!(wqe->wr.send_flags &
 559                                       RVT_SEND_COMPLETION_ONLY)) {
 560                                         err = rvt_invalidate_rkey(
 561                                                 qp,
 562                                                 wqe->wr.ex.invalidate_rkey);
 563                                         local_ops = 1;
 564                                 }
 565                                 rvt_send_complete(qp, wqe,
 566                                                   err ? IB_WC_LOC_PROT_ERR
 567                                                       : IB_WC_SUCCESS);
 568                                 if (local_ops)
 569                                         atomic_dec(&qp->local_ops_pending);
 570                                 goto done_free_tx;
 571                         }
 572
 573                         newreq = 1;
 574                         qp->s_psn = wqe->psn;
 575                 }
 576                 /*
 577                  * Note that we have to be careful not to modify the
 578                  * original work request since we may need to resend
 579                  * it.
 580                  */
 581                 len = wqe->length;
 582                 ss = &qp->s_sge;
 583                 bth2 = mask_psn(qp->s_psn);
 584
 585                 /*
 586                  * Interlock between various IB requests and TID RDMA
 587                  * if necessary.
 588                  */
 589                 if ((priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) ||
 590                     hfi1_tid_rdma_wqe_interlock(qp, wqe))
 591                         goto bail;
 592
 593                 switch (wqe->wr.opcode) {
 594                 case IB_WR_SEND:
 595                 case IB_WR_SEND_WITH_IMM:
 596                 case IB_WR_SEND_WITH_INV:
 597                         /* If no credit, return. */
 598                         if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
 599                             rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
 600                                 qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
 601                                 goto bail;
 602                         }
 603                         if (len > pmtu) {
 604                                 qp->s_state = OP(SEND_FIRST);
 605                                 len = pmtu;
 606                                 break;
 607                         }
 608                         if (wqe->wr.opcode == IB_WR_SEND) {
 609                                 qp->s_state = OP(SEND_ONLY);
 610                         } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 611                                 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
 612                                 /* Immediate data comes after the BTH */
 613                                 ohdr->u.imm_data = wqe->wr.ex.imm_data;
 614                                 hwords += 1;
 615                         } else {
 616                                 qp->s_state = OP(SEND_ONLY_WITH_INVALIDATE);
 617                                 /* Invalidate rkey comes after the BTH */
 618                                 ohdr->u.ieth = cpu_to_be32(
 619                                                 wqe->wr.ex.invalidate_rkey);
 620                                 hwords += 1;
 621                         }
 622                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 623                                 bth0 |= IB_BTH_SOLICITED;
 624                         bth2 |= IB_BTH_REQ_ACK;
 625                         if (++qp->s_cur == qp->s_size)
 626                                 qp->s_cur = 0;
 627                         break;
 628
 629                 case IB_WR_RDMA_WRITE:
 630                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 631                                 qp->s_lsn++;
 632                         goto no_flow_control;
 633                 case IB_WR_RDMA_WRITE_WITH_IMM:
 634                         /* If no credit, return. */
 635                         if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
 636                             rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
 637                                 qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
 638                                 goto bail;
 639                         }
 640 no_flow_control:
 641                         put_ib_reth_vaddr(
 642                                 wqe->rdma_wr.remote_addr,
 643                                 &ohdr->u.rc.reth);
 644                         ohdr->u.rc.reth.rkey =
 645                                 cpu_to_be32(wqe->rdma_wr.rkey);
 646                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 647                         hwords += sizeof(struct ib_reth) / sizeof(u32);
 648                         if (len > pmtu) {
 649                                 qp->s_state = OP(RDMA_WRITE_FIRST);
 650                                 len = pmtu;
 651                                 break;
 652                         }
 653                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 654                                 qp->s_state = OP(RDMA_WRITE_ONLY);
 655                         } else {
 656                                 qp->s_state =
 657                                         OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
 658                                 /* Immediate data comes after RETH */
 659                                 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
 660                                 hwords += 1;
 661                                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 662                                         bth0 |= IB_BTH_SOLICITED;
 663                         }
 664                         bth2 |= IB_BTH_REQ_ACK;
 665                         if (++qp->s_cur == qp->s_size)
 666                                 qp->s_cur = 0;
 667                         break;
 668
 669                 case IB_WR_TID_RDMA_WRITE:
 670                         if (newreq) {
 671                                 /*
 672                                  * Limit the number of TID RDMA WRITE requests.
 673                                  */
 674                                 if (atomic_read(&priv->n_tid_requests) >=
 675                                     HFI1_TID_RDMA_WRITE_CNT)
 676                                         goto bail;
 677
 678                                 if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 679                                         qp->s_lsn++;
 680                         }
 681
 682                         hwords += hfi1_build_tid_rdma_write_req(qp, wqe, ohdr,
 683                                                                 &bth1, &bth2,
 684                                                                 &len);
 685                         ss = NULL;
 686                         if (priv->s_tid_cur == HFI1_QP_WQE_INVALID) {
 687                                 priv->s_tid_cur = qp->s_cur;
 688                                 if (priv->s_tid_tail == HFI1_QP_WQE_INVALID) {
 689                                         priv->s_tid_tail = qp->s_cur;
 690                                         priv->s_state = TID_OP(WRITE_RESP);
 691                                 }
 692                         } else if (priv->s_tid_cur == priv->s_tid_head) {
 693                                 struct rvt_swqe *__w;
 694                                 struct tid_rdma_request *__r;
 695
 696                                 __w = rvt_get_swqe_ptr(qp, priv->s_tid_cur);
 697                                 __r = wqe_to_tid_req(__w);
 698
 699                                 /*
 700                                  * The s_tid_cur pointer is advanced to s_cur if
 701                                  * any of the following conditions about the WQE
 702                                  * to which s_ti_cur currently points to are
 703                                  * satisfied:
 704                                  *   1. The request is not a TID RDMA WRITE
 705                                  *      request,
 706                                  *   2. The request is in the INACTIVE or
 707                                  *      COMPLETE states (TID RDMA READ requests
 708                                  *      stay at INACTIVE and TID RDMA WRITE
 709                                  *      transition to COMPLETE when done),
 710                                  *   3. The request is in the ACTIVE or SYNC
 711                                  *      state and the number of completed
 712                                  *      segments is equal to the total segment
 713                                  *      count.
 714                                  *      (If ACTIVE, the request is waiting for
 715                                  *       ACKs. If SYNC, the request has not
 716                                  *       received any responses because it's
 717                                  *       waiting on a sync point.)
 718                                  */
 719                                 if (__w->wr.opcode != IB_WR_TID_RDMA_WRITE ||
 720                                     __r->state == TID_REQUEST_INACTIVE ||
 721                                     __r->state == TID_REQUEST_COMPLETE ||
 722                                     ((__r->state == TID_REQUEST_ACTIVE ||
 723                                       __r->state == TID_REQUEST_SYNC) &&
 724                                      __r->comp_seg == __r->total_segs)) {
 725                                         if (priv->s_tid_tail ==
 726                                             priv->s_tid_cur &&
 727                                             priv->s_state ==
 728                                             TID_OP(WRITE_DATA_LAST)) {
 729                                                 priv->s_tid_tail = qp->s_cur;
 730                                                 priv->s_state =
 731                                                         TID_OP(WRITE_RESP);
 732                                         }
 733                                         priv->s_tid_cur = qp->s_cur;
 734                                 }
 735                                 /*
 736                                  * A corner case: when the last TID RDMA WRITE
 737                                  * request was completed, s_tid_head,
 738                                  * s_tid_cur, and s_tid_tail all point to the
 739                                  * same location. Other requests are posted and
 740                                  * s_cur wraps around to the same location,
 741                                  * where a new TID RDMA WRITE is posted. In
 742                                  * this case, none of the indices need to be
 743                                  * updated. However, the priv->s_state should.
 744                                  */
 745                                 if (priv->s_tid_tail == qp->s_cur &&
 746                                     priv->s_state == TID_OP(WRITE_DATA_LAST))
 747                                         priv->s_state = TID_OP(WRITE_RESP);
 748                         }
 749                         req = wqe_to_tid_req(wqe);
 750                         if (newreq) {
 751                                 priv->s_tid_head = qp->s_cur;
 752                                 priv->pending_tid_w_resp += req->total_segs;
 753                                 atomic_inc(&priv->n_tid_requests);
 754                                 atomic_dec(&priv->n_requests);
 755                         } else {
 756                                 req->state = TID_REQUEST_RESEND;
 757                                 req->comp_seg = delta_psn(bth2, wqe->psn);
 758                                 /*
 759                                  * Pull back any segments since we are going
 760                                  * to re-receive them.
 761                                  */
 762                                 req->setup_head = req->clear_tail;
 763                                 priv->pending_tid_w_resp +=
 764                                         delta_psn(wqe->lpsn, bth2) + 1;
 765                         }
 766
 767                         trace_hfi1_tid_write_sender_make_req(qp, newreq);
 768                         trace_hfi1_tid_req_make_req_write(qp, newreq,
 769                                                           wqe->wr.opcode,
 770                                                           wqe->psn, wqe->lpsn,
 771                                                           req);
 772                         if (++qp->s_cur == qp->s_size)
 773                                 qp->s_cur = 0;
 774                         break;
 775
 776                 case IB_WR_RDMA_READ:
 777                         /*
 778                          * Don't allow more operations to be started
 779                          * than the QP limits allow.
 780                          */
 781                         if (qp->s_num_rd_atomic >=
 782                             qp->s_max_rd_atomic) {
 783                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
 784                                 goto bail;
 785                         }
 786                         qp->s_num_rd_atomic++;
 787                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 788                                 qp->s_lsn++;
 789                         put_ib_reth_vaddr(
 790                                 wqe->rdma_wr.remote_addr,
 791                                 &ohdr->u.rc.reth);
 792                         ohdr->u.rc.reth.rkey =
 793                                 cpu_to_be32(wqe->rdma_wr.rkey);
 794                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 795                         qp->s_state = OP(RDMA_READ_REQUEST);
 796                         hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
 797                         ss = NULL;
 798                         len = 0;
 799                         bth2 |= IB_BTH_REQ_ACK;
 800                         if (++qp->s_cur == qp->s_size)
 801                                 qp->s_cur = 0;
 802                         break;
 803
 804                 case IB_WR_TID_RDMA_READ:
 805                         trace_hfi1_tid_read_sender_make_req(qp, newreq);
 806                         wpriv = wqe->priv;
 807                         req = wqe_to_tid_req(wqe);
 808                         trace_hfi1_tid_req_make_req_read(qp, newreq,
 809                                                          wqe->wr.opcode,
 810                                                          wqe->psn, wqe->lpsn,
 811                                                          req);
 812                         delta = cmp_psn(qp->s_psn, wqe->psn);
 813
 814                         /*
 815                          * Don't allow more operations to be started
 816                          * than the QP limits allow. We could get here under
 817                          * three conditions; (1) It's a new request; (2) We are
 818                          * sending the second or later segment of a request,
 819                          * but the qp->s_state is set to OP(RDMA_READ_REQUEST)
 820                          * when the last segment of a previous request is
 821                          * received just before this; (3) We are re-sending a
 822                          * request.
 823                          */
 824                         if (qp->s_num_rd_atomic >= qp->s_max_rd_atomic) {
 825                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
 826                                 goto bail;
 827                         }
 828                         if (newreq) {
 829                                 struct tid_rdma_flow *flow =
 830                                         &req->flows[req->setup_head];
 831
 832                                 /*
 833                                  * Set up s_sge as it is needed for TID
 834                                  * allocation. However, if the pages have been
 835                                  * walked and mapped, skip it. An earlier try
 836                                  * has failed to allocate the TID entries.
 837                                  */
 838                                 if (!flow->npagesets) {
 839                                         qp->s_sge.sge = wqe->sg_list[0];
 840                                         qp->s_sge.sg_list = wqe->sg_list + 1;
 841                                         qp->s_sge.num_sge = wqe->wr.num_sge;
 842                                         qp->s_sge.total_len = wqe->length;
 843                                         qp->s_len = wqe->length;
 844                                         req->isge = 0;
 845                                         req->clear_tail = req->setup_head;
 846                                         req->flow_idx = req->setup_head;
 847                                         req->state = TID_REQUEST_ACTIVE;
 848                                 }
 849                         } else if (delta == 0) {
 850                                 /* Re-send a request */
 851                                 req->cur_seg = 0;
 852                                 req->comp_seg = 0;
 853                                 req->ack_pending = 0;
 854                                 req->flow_idx = req->clear_tail;
 855                                 req->state = TID_REQUEST_RESEND;
 856                         }
 857                         req->s_next_psn = qp->s_psn;
 858                         /* Read one segment at a time */
 859                         len = min_t(u32, req->seg_len,
 860                                     wqe->length - req->seg_len * req->cur_seg);
 861                         delta = hfi1_build_tid_rdma_read_req(qp, wqe, ohdr,
 862                                                              &bth1, &bth2,
 863                                                              &len);
 864                         if (delta <= 0) {
 865                                 /* Wait for TID space */
 866                                 goto bail;
 867                         }
 868                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 869                                 qp->s_lsn++;
 870                         hwords += delta;
 871                         ss = &wpriv->ss;
 872                         /* Check if this is the last segment */
 873                         if (req->cur_seg >= req->total_segs &&
 874                             ++qp->s_cur == qp->s_size)
 875                                 qp->s_cur = 0;
 876                         break;
 877
 878                 case IB_WR_ATOMIC_CMP_AND_SWP:
 879                 case IB_WR_ATOMIC_FETCH_AND_ADD:
 880                         /*
 881                          * Don't allow more operations to be started
 882                          * than the QP limits allow.
 883                          */
 884                         if (qp->s_num_rd_atomic >=
 885                             qp->s_max_rd_atomic) {
 886                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
 887                                 goto bail;
 888                         }
 889                         qp->s_num_rd_atomic++;
 890
 891                         /* FALLTHROUGH */
 892                 case IB_WR_OPFN:
 893                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 894                                 qp->s_lsn++;
 895                         if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
 896                             wqe->wr.opcode == IB_WR_OPFN) {
 897                                 qp->s_state = OP(COMPARE_SWAP);
 898                                 put_ib_ateth_swap(wqe->atomic_wr.swap,
 899                                                   &ohdr->u.atomic_eth);
 900                                 put_ib_ateth_compare(wqe->atomic_wr.compare_add,
 901                                                      &ohdr->u.atomic_eth);
 902                         } else {
 903                                 qp->s_state = OP(FETCH_ADD);
 904                                 put_ib_ateth_swap(wqe->atomic_wr.compare_add,
 905                                                   &ohdr->u.atomic_eth);
 906                                 put_ib_ateth_compare(0, &ohdr->u.atomic_eth);
 907                         }
 908                         put_ib_ateth_vaddr(wqe->atomic_wr.remote_addr,
 909                                            &ohdr->u.atomic_eth);
 910                         ohdr->u.atomic_eth.rkey = cpu_to_be32(
 911                                 wqe->atomic_wr.rkey);
 912                         hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
 913                         ss = NULL;
 914                         len = 0;
 915                         bth2 |= IB_BTH_REQ_ACK;
 916                         if (++qp->s_cur == qp->s_size)
 917                                 qp->s_cur = 0;
 918                         break;
 919
 920                 default:
 921                         goto bail;
 922                 }
 923                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ) {
 924                         qp->s_sge.sge = wqe->sg_list[0];
 925                         qp->s_sge.sg_list = wqe->sg_list + 1;
 926                         qp->s_sge.num_sge = wqe->wr.num_sge;
 927                         qp->s_sge.total_len = wqe->length;
 928                         qp->s_len = wqe->length;
 929                 }
 930                 if (newreq) {
 931                         qp->s_tail++;
 932                         if (qp->s_tail >= qp->s_size)
 933                                 qp->s_tail = 0;
 934                 }
 935                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
 936                     wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
 937                         qp->s_psn = wqe->lpsn + 1;
 938                 else if (wqe->wr.opcode == IB_WR_TID_RDMA_READ)
 939                         qp->s_psn = req->s_next_psn;
 940                 else
 941                         qp->s_psn++;
 942                 break;
 943
 944         case OP(RDMA_READ_RESPONSE_FIRST):
 945                 /*
 946                  * qp->s_state is normally set to the opcode of the
 947                  * last packet constructed for new requests and therefore
 948                  * is never set to RDMA read response.
 949                  * RDMA_READ_RESPONSE_FIRST is used by the ACK processing
 950                  * thread to indicate a SEND needs to be restarted from an
 951                  * earlier PSN without interfering with the sending thread.
 952                  * See restart_rc().
 953                  */
 954                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
 955                 /* FALLTHROUGH */
 956         case OP(SEND_FIRST):
 957                 qp->s_state = OP(SEND_MIDDLE);
 958                 /* FALLTHROUGH */
 959         case OP(SEND_MIDDLE):
 960                 bth2 = mask_psn(qp->s_psn++);
 961                 ss = &qp->s_sge;
 962                 len = qp->s_len;
 963                 if (len > pmtu) {
 964                         len = pmtu;
 965                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 966                         break;
 967                 }
 968                 if (wqe->wr.opcode == IB_WR_SEND) {
 969                         qp->s_state = OP(SEND_LAST);
 970                 } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 971                         qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
 972                         /* Immediate data comes after the BTH */
 973                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 974                         hwords += 1;
 975                 } else {
 976                         qp->s_state = OP(SEND_LAST_WITH_INVALIDATE);
 977                         /* invalidate data comes after the BTH */
 978                         ohdr->u.ieth = cpu_to_be32(wqe->wr.ex.invalidate_rkey);
 979                         hwords += 1;
 980                 }
 981                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 982                         bth0 |= IB_BTH_SOLICITED;
 983                 bth2 |= IB_BTH_REQ_ACK;
 984                 qp->s_cur++;
 985                 if (qp->s_cur >= qp->s_size)
 986                         qp->s_cur = 0;
 987                 break;
 988
 989         case OP(RDMA_READ_RESPONSE_LAST):
 990                 /*
 991                  * qp->s_state is normally set to the opcode of the
 992                  * last packet constructed for new requests and therefore
 993                  * is never set to RDMA read response.
 994                  * RDMA_READ_RESPONSE_LAST is used by the ACK processing
 995                  * thread to indicate a RDMA write needs to be restarted from
 996                  * an earlier PSN without interfering with the sending thread.
 997                  * See restart_rc().
 998                  */
 999                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
1000                 /* FALLTHROUGH */
1001         case OP(RDMA_WRITE_FIRST):
1002                 qp->s_state = OP(RDMA_WRITE_MIDDLE);
1003                 /* FALLTHROUGH */
1004         case OP(RDMA_WRITE_MIDDLE):
1005                 bth2 = mask_psn(qp->s_psn++);
1006                 ss = &qp->s_sge;
1007                 len = qp->s_len;
1008                 if (len > pmtu) {
1009                         len = pmtu;
1010                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
1011                         break;
1012                 }
1013                 if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
1014                         qp->s_state = OP(RDMA_WRITE_LAST);
1015                 } else {
1016                         qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
1017                         /* Immediate data comes after the BTH */
1018                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
1019                         hwords += 1;
1020                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
1021                                 bth0 |= IB_BTH_SOLICITED;
1022                 }
1023                 bth2 |= IB_BTH_REQ_ACK;
1024                 qp->s_cur++;
1025                 if (qp->s_cur >= qp->s_size)
1026                         qp->s_cur = 0;
1027                 break;
1028
1029         case OP(RDMA_READ_RESPONSE_MIDDLE):
1030                 /*
1031                  * qp->s_state is normally set to the opcode of the
1032                  * last packet constructed for new requests and therefore
1033                  * is never set to RDMA read response.
1034                  * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing
1035                  * thread to indicate a RDMA read needs to be restarted from
1036                  * an earlier PSN without interfering with the sending thread.
1037                  * See restart_rc().
1038                  */
1039                 len = (delta_psn(qp->s_psn, wqe->psn)) * pmtu;
1040                 put_ib_reth_vaddr(
1041                         wqe->rdma_wr.remote_addr + len,
1042                         &ohdr->u.rc.reth);
1043                 ohdr->u.rc.reth.rkey =
1044                         cpu_to_be32(wqe->rdma_wr.rkey);
1045                 ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len);
1046                 qp->s_state = OP(RDMA_READ_REQUEST);
1047                 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
1048                 bth2 = mask_psn(qp->s_psn) | IB_BTH_REQ_ACK;
1049                 qp->s_psn = wqe->lpsn + 1;
1050                 ss = NULL;
1051                 len = 0;
1052                 qp->s_cur++;
1053                 if (qp->s_cur == qp->s_size)
1054                         qp->s_cur = 0;
1055                 break;
1056
1057         case TID_OP(WRITE_RESP):
1058                 /*
1059                  * This value for s_state is used for restarting a TID RDMA
1060                  * WRITE request. See comment in OP(RDMA_READ_RESPONSE_MIDDLE
1061                  * for more).
1062                  */
1063                 req = wqe_to_tid_req(wqe);
1064                 req->state = TID_REQUEST_RESEND;
1065                 rcu_read_lock();
1066                 remote = rcu_dereference(priv->tid_rdma.remote);
1067                 req->comp_seg = delta_psn(qp->s_psn, wqe->psn);
1068                 len = wqe->length - (req->comp_seg * remote->max_len);
1069                 rcu_read_unlock();
1070
1071                 bth2 = mask_psn(qp->s_psn);
1072                 hwords += hfi1_build_tid_rdma_write_req(qp, wqe, ohdr, &bth1,
1073                                                         &bth2, &len);
1074                 qp->s_psn = wqe->lpsn + 1;
1075                 ss = NULL;
1076                 qp->s_state = TID_OP(WRITE_REQ);
1077                 priv->pending_tid_w_resp += delta_psn(wqe->lpsn, bth2) + 1;
1078                 priv->s_tid_cur = qp->s_cur;
1079                 if (++qp->s_cur == qp->s_size)
1080                         qp->s_cur = 0;
1081                 trace_hfi1_tid_req_make_req_write(qp, 0, wqe->wr.opcode,
1082                                                   wqe->psn, wqe->lpsn, req);
1083                 break;
1084
1085         case TID_OP(READ_RESP):
1086                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ)
1087                         goto bail;
1088                 /* This is used to restart a TID read request */
1089                 req = wqe_to_tid_req(wqe);
1090                 wpriv = wqe->priv;
1091                 /*
1092                  * Back down. The field qp->s_psn has been set to the psn with
1093                  * which the request should be restart. It's OK to use division
1094                  * as this is on the retry path.
1095                  */
1096                 req->cur_seg = delta_psn(qp->s_psn, wqe->psn) / priv->pkts_ps;
1097
1098                 /*
1099                  * The following function need to be redefined to return the
1100                  * status to make sure that we find the flow. At the same
1101                  * time, we can use the req->state change to check if the
1102                  * call succeeds or not.
1103                  */
1104                 req->state = TID_REQUEST_RESEND;
1105                 hfi1_tid_rdma_restart_req(qp, wqe, &bth2);
1106                 if (req->state != TID_REQUEST_ACTIVE) {
1107                         /*
1108                          * Failed to find the flow. Release all allocated tid
1109                          * resources.
1110                          */
1111                         hfi1_kern_exp_rcv_clear_all(req);
1112                         hfi1_kern_clear_hw_flow(priv->rcd, qp);
1113
1114                         hfi1_trdma_send_complete(qp, wqe, IB_WC_LOC_QP_OP_ERR);
1115                         goto bail;
1116                 }
1117                 req->state = TID_REQUEST_RESEND;
1118                 len = min_t(u32, req->seg_len,
1119                             wqe->length - req->seg_len * req->cur_seg);
1120                 flow = &req->flows[req->flow_idx];
1121                 len -= flow->sent;
1122                 req->s_next_psn = flow->flow_state.ib_lpsn + 1;
1123                 delta = hfi1_build_tid_rdma_read_packet(wqe, ohdr, &bth1,
1124                                                         &bth2, &len);
1125                 if (delta <= 0) {
1126                         /* Wait for TID space */
1127                         goto bail;
1128                 }
1129                 hwords += delta;
1130                 ss = &wpriv->ss;
1131                 /* Check if this is the last segment */
1132                 if (req->cur_seg >= req->total_segs &&
1133                     ++qp->s_cur == qp->s_size)
1134                         qp->s_cur = 0;
1135                 qp->s_psn = req->s_next_psn;
1136                 trace_hfi1_tid_req_make_req_read(qp, 0, wqe->wr.opcode,
1137                                                  wqe->psn, wqe->lpsn, req);
1138                 break;
1139         case TID_OP(READ_REQ):
1140                 req = wqe_to_tid_req(wqe);
1141                 delta = cmp_psn(qp->s_psn, wqe->psn);
1142                 /*
1143                  * If the current WR is not TID RDMA READ, or this is the start
1144                  * of a new request, we need to change the qp->s_state so that
1145                  * the request can be set up properly.
1146                  */
1147                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ || delta == 0 ||
1148                     qp->s_cur == qp->s_tail) {
1149                         qp->s_state = OP(RDMA_READ_REQUEST);
1150                         if (delta == 0 || qp->s_cur == qp->s_tail)
1151                                 goto check_s_state;
1152                         else
1153                                 goto bail;
1154                 }
1155
1156                 /* Rate limiting */
1157                 if (qp->s_num_rd_atomic >= qp->s_max_rd_atomic) {
1158                         qp->s_flags |= RVT_S_WAIT_RDMAR;
1159                         goto bail;
1160                 }
1161
1162                 wpriv = wqe->priv;
1163                 /* Read one segment at a time */
1164                 len = min_t(u32, req->seg_len,
1165                             wqe->length - req->seg_len * req->cur_seg);
1166                 delta = hfi1_build_tid_rdma_read_req(qp, wqe, ohdr, &bth1,
1167                                                      &bth2, &len);
1168                 if (delta <= 0) {
1169                         /* Wait for TID space */
1170                         goto bail;
1171                 }
1172                 hwords += delta;
1173                 ss = &wpriv->ss;
1174                 /* Check if this is the last segment */
1175                 if (req->cur_seg >= req->total_segs &&
1176                     ++qp->s_cur == qp->s_size)
1177                         qp->s_cur = 0;
1178                 qp->s_psn = req->s_next_psn;
1179                 trace_hfi1_tid_req_make_req_read(qp, 0, wqe->wr.opcode,
1180                                                  wqe->psn, wqe->lpsn, req);
1181                 break;
1182         }
1183         qp->s_sending_hpsn = bth2;
1184         delta = delta_psn(bth2, wqe->psn);
1185         if (delta && delta % HFI1_PSN_CREDIT == 0 &&
1186             wqe->wr.opcode != IB_WR_TID_RDMA_WRITE)
1187                 bth2 |= IB_BTH_REQ_ACK;
1188         if (qp->s_flags & RVT_S_SEND_ONE) {
1189                 qp->s_flags &= ~RVT_S_SEND_ONE;
1190                 qp->s_flags |= RVT_S_WAIT_ACK;
1191                 bth2 |= IB_BTH_REQ_ACK;
1192         }
1193         qp->s_len -= len;
1194         ps->s_txreq->hdr_dwords = hwords;
1195         ps->s_txreq->sde = priv->s_sde;
1196         ps->s_txreq->ss = ss;
1197         ps->s_txreq->s_cur_size = len;
1198         hfi1_make_ruc_header(
1199                 qp,
1200                 ohdr,
1201                 bth0 | (qp->s_state << 24),
1202                 bth1,
1203                 bth2,
1204                 middle,
1205                 ps);
1206         return 1;
1207
1208 done_free_tx:
1209         hfi1_put_txreq(ps->s_txreq);
1210         ps->s_txreq = NULL;
1211         return 1;
1212
1213 bail:
1214         hfi1_put_txreq(ps->s_txreq);
1215
1216 bail_no_tx:
1217         ps->s_txreq = NULL;
1218         qp->s_flags &= ~RVT_S_BUSY;
1219         /*
1220          * If we didn't get a txreq, the QP will be woken up later to try
1221          * again. Set the flags to indicate which work item to wake
1222          * up.
1223          */
1224         iowait_set_flag(&priv->s_iowait, IOWAIT_PENDING_IB);
1225         return 0;
1226 }
1227
1228 static inline void hfi1_make_bth_aeth(struct rvt_qp *qp,
1229                                       struct ib_other_headers *ohdr,
1230                                       u32 bth0, u32 bth1)
1231 {
1232         if (qp->r_nak_state)
1233                 ohdr->u.aeth = cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
1234                                             (qp->r_nak_state <<
1235                                              IB_AETH_CREDIT_SHIFT));
1236         else
1237                 ohdr->u.aeth = rvt_compute_aeth(qp);
1238
1239         ohdr->bth[0] = cpu_to_be32(bth0);
1240         ohdr->bth[1] = cpu_to_be32(bth1 | qp->remote_qpn);
1241         ohdr->bth[2] = cpu_to_be32(mask_psn(qp->r_ack_psn));
1242 }
1243
1244 static inline void hfi1_queue_rc_ack(struct hfi1_packet *packet, bool is_fecn)
1245 {
1246         struct rvt_qp *qp = packet->qp;
1247         struct hfi1_ibport *ibp;
1248         unsigned long flags;
1249
1250         spin_lock_irqsave(&qp->s_lock, flags);
1251         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
1252                 goto unlock;
1253         ibp = rcd_to_iport(packet->rcd);
1254         this_cpu_inc(*ibp->rvp.rc_qacks);
1255         qp->s_flags |= RVT_S_ACK_PENDING | RVT_S_RESP_PENDING;
1256         qp->s_nak_state = qp->r_nak_state;
1257         qp->s_ack_psn = qp->r_ack_psn;
1258         if (is_fecn)
1259                 qp->s_flags |= RVT_S_ECN;
1260
1261         /* Schedule the send tasklet. */
1262         hfi1_schedule_send(qp);
1263 unlock:
1264         spin_unlock_irqrestore(&qp->s_lock, flags);
1265 }
1266
1267 static inline void hfi1_make_rc_ack_9B(struct hfi1_packet *packet,
1268                                        struct hfi1_opa_header *opa_hdr,
1269                                        u8 sc5, bool is_fecn,
1270                                        u64 *pbc_flags, u32 *hwords,
1271                                        u32 *nwords)
1272 {
1273         struct rvt_qp *qp = packet->qp;
1274         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
1275         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1276         struct ib_header *hdr = &opa_hdr->ibh;
1277         struct ib_other_headers *ohdr;
1278         u16 lrh0 = HFI1_LRH_BTH;
1279         u16 pkey;
1280         u32 bth0, bth1;
1281
1282         opa_hdr->hdr_type = HFI1_PKT_TYPE_9B;
1283         ohdr = &hdr->u.oth;
1284         /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4 */
1285         *hwords = 6;
1286
1287         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)) {
1288                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
1289                                          rdma_ah_read_grh(&qp->remote_ah_attr),
1290                                          *hwords - 2, SIZE_OF_CRC);
1291                 ohdr = &hdr->u.l.oth;
1292                 lrh0 = HFI1_LRH_GRH;
1293         }
1294         /* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
1295         *pbc_flags |= ((!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT);
1296
1297         /* read pkey_index w/o lock (its atomic) */
1298         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
1299
1300         lrh0 |= (sc5 & IB_SC_MASK) << IB_SC_SHIFT |
1301                 (rdma_ah_get_sl(&qp->remote_ah_attr) & IB_SL_MASK) <<
1302                         IB_SL_SHIFT;
1303
1304         hfi1_make_ib_hdr(hdr, lrh0, *hwords + SIZE_OF_CRC,
1305                          opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr), 9B),
1306                          ppd->lid | rdma_ah_get_path_bits(&qp->remote_ah_attr));
1307
1308         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
1309         if (qp->s_mig_state == IB_MIG_MIGRATED)
1310                 bth0 |= IB_BTH_MIG_REQ;
1311         bth1 = (!!is_fecn) << IB_BECN_SHIFT;
1312         /*
1313          * Inline ACKs go out without the use of the Verbs send engine, so
1314          * we need to set the STL Verbs Extended bit here
1315          */
1316         bth1 |= HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT;
1317         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
1318 }
1319
1320 static inline void hfi1_make_rc_ack_16B(struct hfi1_packet *packet,
1321                                         struct hfi1_opa_header *opa_hdr,
1322                                         u8 sc5, bool is_fecn,
1323                                         u64 *pbc_flags, u32 *hwords,
1324                                         u32 *nwords)
1325 {
1326         struct rvt_qp *qp = packet->qp;
1327         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
1328         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1329         struct hfi1_16b_header *hdr = &opa_hdr->opah;
1330         struct ib_other_headers *ohdr;
1331         u32 bth0, bth1 = 0;
1332         u16 len, pkey;
1333         bool becn = is_fecn;
1334         u8 l4 = OPA_16B_L4_IB_LOCAL;
1335         u8 extra_bytes;
1336
1337         opa_hdr->hdr_type = HFI1_PKT_TYPE_16B;
1338         ohdr = &hdr->u.oth;
1339         /* header size in 32-bit words 16B LRH+BTH+AETH = (16+12+4)/4 */
1340         *hwords = 8;
1341         extra_bytes = hfi1_get_16b_padding(*hwords << 2, 0);
1342         *nwords = SIZE_OF_CRC + ((extra_bytes + SIZE_OF_LT) >> 2);
1343
1344         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
1345             hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))) {
1346                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
1347                                          rdma_ah_read_grh(&qp->remote_ah_attr),
1348                                          *hwords - 4, *nwords);
1349                 ohdr = &hdr->u.l.oth;
1350                 l4 = OPA_16B_L4_IB_GLOBAL;
1351         }
1352         *pbc_flags |= PBC_PACKET_BYPASS | PBC_INSERT_BYPASS_ICRC;
1353
1354         /* read pkey_index w/o lock (its atomic) */
1355         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
1356
1357         /* Convert dwords to flits */
1358         len = (*hwords + *nwords) >> 1;
1359
1360         hfi1_make_16b_hdr(hdr, ppd->lid |
1361                           (rdma_ah_get_path_bits(&qp->remote_ah_attr) &
1362                           ((1 << ppd->lmc) - 1)),
1363                           opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr),
1364                                       16B), len, pkey, becn, 0, l4, sc5);
1365
1366         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
1367         bth0 |= extra_bytes << 20;
1368         if (qp->s_mig_state == IB_MIG_MIGRATED)
1369                 bth1 = OPA_BTH_MIG_REQ;
1370         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
1371 }
1372
1373 typedef void (*hfi1_make_rc_ack)(struct hfi1_packet *packet,
1374                                  struct hfi1_opa_header *opa_hdr,
1375                                  u8 sc5, bool is_fecn,
1376                                  u64 *pbc_flags, u32 *hwords,
1377                                  u32 *nwords);
1378
1379 /* We support only two types - 9B and 16B for now */
1380 static const hfi1_make_rc_ack hfi1_make_rc_ack_tbl[2] = {
1381         [HFI1_PKT_TYPE_9B] = &hfi1_make_rc_ack_9B,
1382         [HFI1_PKT_TYPE_16B] = &hfi1_make_rc_ack_16B
1383 };
1384
1385 /**
1386  * hfi1_send_rc_ack - Construct an ACK packet and send it
1387  * @qp: a pointer to the QP
1388  *
1389  * This is called from hfi1_rc_rcv() and handle_receive_interrupt().
1390  * Note that RDMA reads and atomics are handled in the
1391  * send side QP state and send engine.
1392  */
1393 void hfi1_send_rc_ack(struct hfi1_packet *packet, bool is_fecn)
1394 {
1395         struct hfi1_ctxtdata *rcd = packet->rcd;
1396         struct rvt_qp *qp = packet->qp;
1397         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
1398         struct hfi1_qp_priv *priv = qp->priv;
1399         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1400         u8 sc5 = ibp->sl_to_sc[rdma_ah_get_sl(&qp->remote_ah_attr)];
1401         u64 pbc, pbc_flags = 0;
1402         u32 hwords = 0;
1403         u32 nwords = 0;
1404         u32 plen;
1405         struct pio_buf *pbuf;
1406         struct hfi1_opa_header opa_hdr;
1407
1408         /* clear the defer count */
1409         qp->r_adefered = 0;
1410
1411         /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
1412         if (qp->s_flags & RVT_S_RESP_PENDING) {
1413                 hfi1_queue_rc_ack(packet, is_fecn);
1414                 return;
1415         }
1416
1417         /* Ensure s_rdma_ack_cnt changes are committed */
1418         if (qp->s_rdma_ack_cnt) {
1419                 hfi1_queue_rc_ack(packet, is_fecn);
1420                 return;
1421         }
1422
1423         /* Don't try to send ACKs if the link isn't ACTIVE */
1424         if (driver_lstate(ppd) != IB_PORT_ACTIVE)
1425                 return;
1426
1427         /* Make the appropriate header */
1428         hfi1_make_rc_ack_tbl[priv->hdr_type](packet, &opa_hdr, sc5, is_fecn,
1429                                              &pbc_flags, &hwords, &nwords);
1430
1431         plen = 2 /* PBC */ + hwords + nwords;
1432         pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps,
1433                          sc_to_vlt(ppd->dd, sc5), plen);
1434         pbuf = sc_buffer_alloc(rcd->sc, plen, NULL, NULL);
1435         if (IS_ERR_OR_NULL(pbuf)) {
1436                 /*
1437                  * We have no room to send at the moment.  Pass
1438                  * responsibility for sending the ACK to the send engine
1439                  * so that when enough buffer space becomes available,
1440                  * the ACK is sent ahead of other outgoing packets.
1441                  */
1442                 hfi1_queue_rc_ack(packet, is_fecn);
1443                 return;
1444         }
1445         trace_ack_output_ibhdr(dd_from_ibdev(qp->ibqp.device),
1446                                &opa_hdr, ib_is_sc5(sc5));
1447
1448         /* write the pbc and data */
1449         ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc,
1450                                  (priv->hdr_type == HFI1_PKT_TYPE_9B ?
1451                                  (void *)&opa_hdr.ibh :
1452                                  (void *)&opa_hdr.opah), hwords);
1453         return;
1454 }
1455
1456 /**
1457  * update_num_rd_atomic - update the qp->s_num_rd_atomic
1458  * @qp: the QP
1459  * @psn: the packet sequence number to restart at
1460  * @wqe: the wqe
1461  *
1462  * This is called from reset_psn() to update qp->s_num_rd_atomic
1463  * for the current wqe.
1464  * Called at interrupt level with the QP s_lock held.
1465  */
1466 static void update_num_rd_atomic(struct rvt_qp *qp, u32 psn,
1467                                  struct rvt_swqe *wqe)
1468 {
1469         u32 opcode = wqe->wr.opcode;
1470
1471         if (opcode == IB_WR_RDMA_READ ||
1472             opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1473             opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
1474                 qp->s_num_rd_atomic++;
1475         } else if (opcode == IB_WR_TID_RDMA_READ) {
1476                 struct tid_rdma_request *req = wqe_to_tid_req(wqe);
1477                 struct hfi1_qp_priv *priv = qp->priv;
1478
1479                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
1480                         u32 cur_seg;
1481
1482                         cur_seg = (psn - wqe->psn) / priv->pkts_ps;
1483                         req->ack_pending = cur_seg - req->comp_seg;
1484                         priv->pending_tid_r_segs += req->ack_pending;
1485                         qp->s_num_rd_atomic += req->ack_pending;
1486                 } else {
1487                         priv->pending_tid_r_segs += req->total_segs;
1488                         qp->s_num_rd_atomic += req->total_segs;
1489                 }
1490         }
1491 }
1492
1493 /**
1494  * reset_psn - reset the QP state to send starting from PSN
1495  * @qp: the QP
1496  * @psn: the packet sequence number to restart at
1497  *
1498  * This is called from hfi1_rc_rcv() to process an incoming RC ACK
1499  * for the given QP.
1500  * Called at interrupt level with the QP s_lock held.
1501  */
1502 static void reset_psn(struct rvt_qp *qp, u32 psn)
1503 {
1504         u32 n = qp->s_acked;
1505         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, n);
1506         u32 opcode;
1507         struct hfi1_qp_priv *priv = qp->priv;
1508
1509         lockdep_assert_held(&qp->s_lock);
1510         qp->s_cur = n;
1511         priv->pending_tid_r_segs = 0;
1512         priv->pending_tid_w_resp = 0;
1513         qp->s_num_rd_atomic = 0;
1514
1515         /*
1516          * If we are starting the request from the beginning,
1517          * let the normal send code handle initialization.
1518          */
1519         if (cmp_psn(psn, wqe->psn) <= 0) {
1520                 qp->s_state = OP(SEND_LAST);
1521                 goto done;
1522         }
1523         update_num_rd_atomic(qp, psn, wqe);
1524
1525         /* Find the work request opcode corresponding to the given PSN. */
1526         for (;;) {
1527                 int diff;
1528
1529                 if (++n == qp->s_size)
1530                         n = 0;
1531                 if (n == qp->s_tail)
1532                         break;
1533                 wqe = rvt_get_swqe_ptr(qp, n);
1534                 diff = cmp_psn(psn, wqe->psn);
1535                 if (diff < 0) {
1536                         /* Point wqe back to the previous one*/
1537                         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1538                         break;
1539                 }
1540                 qp->s_cur = n;
1541                 /*
1542                  * If we are starting the request from the beginning,
1543                  * let the normal send code handle initialization.
1544                  */
1545                 if (diff == 0) {
1546                         qp->s_state = OP(SEND_LAST);
1547                         goto done;
1548                 }
1549
1550                 update_num_rd_atomic(qp, psn, wqe);
1551         }
1552         opcode = wqe->wr.opcode;
1553
1554         /*
1555          * Set the state to restart in the middle of a request.
1556          * Don't change the s_sge, s_cur_sge, or s_cur_size.
1557          * See hfi1_make_rc_req().
1558          */
1559         switch (opcode) {
1560         case IB_WR_SEND:
1561         case IB_WR_SEND_WITH_IMM:
1562                 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
1563                 break;
1564
1565         case IB_WR_RDMA_WRITE:
1566         case IB_WR_RDMA_WRITE_WITH_IMM:
1567                 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
1568                 break;
1569
1570         case IB_WR_TID_RDMA_WRITE:
1571                 qp->s_state = TID_OP(WRITE_RESP);
1572                 break;
1573
1574         case IB_WR_RDMA_READ:
1575                 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
1576                 break;
1577
1578         case IB_WR_TID_RDMA_READ:
1579                 qp->s_state = TID_OP(READ_RESP);
1580                 break;
1581
1582         default:
1583                 /*
1584                  * This case shouldn't happen since its only
1585                  * one PSN per req.
1586                  */
1587                 qp->s_state = OP(SEND_LAST);
1588         }
1589 done:
1590         priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
1591         qp->s_psn = psn;
1592         /*
1593          * Set RVT_S_WAIT_PSN as rc_complete() may start the timer
1594          * asynchronously before the send engine can get scheduled.
1595          * Doing it in hfi1_make_rc_req() is too late.
1596          */
1597         if ((cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) &&
1598             (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0))
1599                 qp->s_flags |= RVT_S_WAIT_PSN;
1600         qp->s_flags &= ~HFI1_S_AHG_VALID;
1601         trace_hfi1_sender_reset_psn(qp);
1602 }
1603
1604 /*
1605  * Back up requester to resend the last un-ACKed request.
1606  * The QP r_lock and s_lock should be held and interrupts disabled.
1607  */
1608 void hfi1_restart_rc(struct rvt_qp *qp, u32 psn, int wait)
1609 {
1610         struct hfi1_qp_priv *priv = qp->priv;
1611         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1612         struct hfi1_ibport *ibp;
1613
1614         lockdep_assert_held(&qp->r_lock);
1615         lockdep_assert_held(&qp->s_lock);
1616         trace_hfi1_sender_restart_rc(qp);
1617         if (qp->s_retry == 0) {
1618                 if (qp->s_mig_state == IB_MIG_ARMED) {
1619                         hfi1_migrate_qp(qp);
1620                         qp->s_retry = qp->s_retry_cnt;
1621                 } else if (qp->s_last == qp->s_acked) {
1622                         /*
1623                          * We need special handling for the OPFN request WQEs as
1624                          * they are not allowed to generate real user errors
1625                          */
1626                         if (wqe->wr.opcode == IB_WR_OPFN) {
1627                                 struct hfi1_ibport *ibp =
1628                                         to_iport(qp->ibqp.device, qp->port_num);
1629                                 /*
1630                                  * Call opfn_conn_reply() with capcode and
1631                                  * remaining data as 0 to close out the
1632                                  * current request
1633                                  */
1634                                 opfn_conn_reply(qp, priv->opfn.curr);
1635                                 wqe = do_rc_completion(qp, wqe, ibp);
1636                                 qp->s_flags &= ~RVT_S_WAIT_ACK;
1637                         } else {
1638                                 trace_hfi1_tid_write_sender_restart_rc(qp, 0);
1639                                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ) {
1640                                         struct tid_rdma_request *req;
1641
1642                                         req = wqe_to_tid_req(wqe);
1643                                         hfi1_kern_exp_rcv_clear_all(req);
1644                                         hfi1_kern_clear_hw_flow(priv->rcd, qp);
1645                                 }
1646
1647                                 hfi1_trdma_send_complete(qp, wqe,
1648                                                          IB_WC_RETRY_EXC_ERR);
1649                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1650                         }
1651                         return;
1652                 } else { /* need to handle delayed completion */
1653                         return;
1654                 }
1655         } else {
1656                 qp->s_retry--;
1657         }
1658
1659         ibp = to_iport(qp->ibqp.device, qp->port_num);
1660         if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1661             wqe->wr.opcode == IB_WR_TID_RDMA_READ)
1662                 ibp->rvp.n_rc_resends++;
1663         else
1664                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
1665
1666         qp->s_flags &= ~(RVT_S_WAIT_FENCE | RVT_S_WAIT_RDMAR |
1667                          RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_PSN |
1668                          RVT_S_WAIT_ACK | HFI1_S_WAIT_TID_RESP);
1669         if (wait)
1670                 qp->s_flags |= RVT_S_SEND_ONE;
1671         reset_psn(qp, psn);
1672 }
1673
1674 /*
1675  * Set qp->s_sending_psn to the next PSN after the given one.
1676  * This would be psn+1 except when RDMA reads or TID RDMA ops
1677  * are present.
1678  */
1679 static void reset_sending_psn(struct rvt_qp *qp, u32 psn)
1680 {
1681         struct rvt_swqe *wqe;
1682         u32 n = qp->s_last;
1683
1684         lockdep_assert_held(&qp->s_lock);
1685         /* Find the work request corresponding to the given PSN. */
1686         for (;;) {
1687                 wqe = rvt_get_swqe_ptr(qp, n);
1688                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
1689                         if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1690                             wqe->wr.opcode == IB_WR_TID_RDMA_READ ||
1691                             wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
1692                                 qp->s_sending_psn = wqe->lpsn + 1;
1693                         else
1694                                 qp->s_sending_psn = psn + 1;
1695                         break;
1696                 }
1697                 if (++n == qp->s_size)
1698                         n = 0;
1699                 if (n == qp->s_tail)
1700                         break;
1701         }
1702 }
1703
1704 /**
1705  * hfi1_rc_verbs_aborted - handle abort status
1706  * @qp: the QP
1707  * @opah: the opa header
1708  *
1709  * This code modifies both ACK bit in BTH[2]
1710  * and the s_flags to go into send one mode.
1711  *
1712  * This serves to throttle the send engine to only
1713  * send a single packet in the likely case the
1714  * a link has gone down.
1715  */
1716 void hfi1_rc_verbs_aborted(struct rvt_qp *qp, struct hfi1_opa_header *opah)
1717 {
1718         struct ib_other_headers *ohdr = hfi1_get_rc_ohdr(opah);
1719         u8 opcode = ib_bth_get_opcode(ohdr);
1720         u32 psn;
1721
1722         /* ignore responses */
1723         if ((opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1724              opcode <= OP(ATOMIC_ACKNOWLEDGE)) ||
1725             opcode == TID_OP(READ_RESP) ||
1726             opcode == TID_OP(WRITE_RESP))
1727                 return;
1728
1729         psn = ib_bth_get_psn(ohdr) | IB_BTH_REQ_ACK;
1730         ohdr->bth[2] = cpu_to_be32(psn);
1731         qp->s_flags |= RVT_S_SEND_ONE;
1732 }
1733
1734 /*
1735  * This should be called with the QP s_lock held and interrupts disabled.
1736  */
1737 void hfi1_rc_send_complete(struct rvt_qp *qp, struct hfi1_opa_header *opah)
1738 {
1739         struct ib_other_headers *ohdr;
1740         struct hfi1_qp_priv *priv = qp->priv;
1741         struct rvt_swqe *wqe;
1742         u32 opcode, head, tail;
1743         u32 psn;
1744         struct tid_rdma_request *req;
1745
1746         lockdep_assert_held(&qp->s_lock);
1747         if (!(ib_rvt_state_ops[qp->state] & RVT_SEND_OR_FLUSH_OR_RECV_OK))
1748                 return;
1749
1750         ohdr = hfi1_get_rc_ohdr(opah);
1751         opcode = ib_bth_get_opcode(ohdr);
1752         if ((opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1753              opcode <= OP(ATOMIC_ACKNOWLEDGE)) ||
1754             opcode == TID_OP(READ_RESP) ||
1755             opcode == TID_OP(WRITE_RESP)) {
1756                 WARN_ON(!qp->s_rdma_ack_cnt);
1757                 qp->s_rdma_ack_cnt--;
1758                 return;
1759         }
1760
1761         psn = ib_bth_get_psn(ohdr);
1762         /*
1763          * Don't attempt to reset the sending PSN for packets in the
1764          * KDETH PSN space since the PSN does not match anything.
1765          */
1766         if (opcode != TID_OP(WRITE_DATA) &&
1767             opcode != TID_OP(WRITE_DATA_LAST) &&
1768             opcode != TID_OP(ACK) && opcode != TID_OP(RESYNC))
1769                 reset_sending_psn(qp, psn);
1770
1771         /* Handle TID RDMA WRITE packets differently */
1772         if (opcode >= TID_OP(WRITE_REQ) &&
1773             opcode <= TID_OP(WRITE_DATA_LAST)) {
1774                 head = priv->s_tid_head;
1775                 tail = priv->s_tid_cur;
1776                 /*
1777                  * s_tid_cur is set to s_tid_head in the case, where
1778                  * a new TID RDMA request is being started and all
1779                  * previous ones have been completed.
1780                  * Therefore, we need to do a secondary check in order
1781                  * to properly determine whether we should start the
1782                  * RC timer.
1783                  */
1784                 wqe = rvt_get_swqe_ptr(qp, tail);
1785                 req = wqe_to_tid_req(wqe);
1786                 if (head == tail && req->comp_seg < req->total_segs) {
1787                         if (tail == 0)
1788                                 tail = qp->s_size - 1;
1789                         else
1790                                 tail -= 1;
1791                 }
1792         } else {
1793                 head = qp->s_tail;
1794                 tail = qp->s_acked;
1795         }
1796
1797         /*
1798          * Start timer after a packet requesting an ACK has been sent and
1799          * there are still requests that haven't been acked.
1800          */
1801         if ((psn & IB_BTH_REQ_ACK) && tail != head &&
1802             opcode != TID_OP(WRITE_DATA) && opcode != TID_OP(WRITE_DATA_LAST) &&
1803             opcode != TID_OP(RESYNC) &&
1804             !(qp->s_flags &
1805               (RVT_S_TIMER | RVT_S_WAIT_RNR | RVT_S_WAIT_PSN)) &&
1806             (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
1807                 if (opcode == TID_OP(READ_REQ))
1808                         rvt_add_retry_timer_ext(qp, priv->timeout_shift);
1809                 else
1810                         rvt_add_retry_timer(qp);
1811         }
1812
1813         /* Start TID RDMA ACK timer */
1814         if ((opcode == TID_OP(WRITE_DATA) ||
1815              opcode == TID_OP(WRITE_DATA_LAST) ||
1816              opcode == TID_OP(RESYNC)) &&
1817             (psn & IB_BTH_REQ_ACK) &&
1818             !(priv->s_flags & HFI1_S_TID_RETRY_TIMER) &&
1819             (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
1820                 /*
1821                  * The TID RDMA ACK packet could be received before this
1822                  * function is called. Therefore, add the timer only if TID
1823                  * RDMA ACK packets are actually pending.
1824                  */
1825                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1826                 req = wqe_to_tid_req(wqe);
1827                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
1828                     req->ack_seg < req->cur_seg)
1829                         hfi1_add_tid_retry_timer(qp);
1830         }
1831
1832         while (qp->s_last != qp->s_acked) {
1833                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
1834                 if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 &&
1835                     cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
1836                         break;
1837                 trdma_clean_swqe(qp, wqe);
1838                 trace_hfi1_qp_send_completion(qp, wqe, qp->s_last);
1839                 rvt_qp_complete_swqe(qp,
1840                                      wqe,
1841                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1842                                      IB_WC_SUCCESS);
1843         }
1844         /*
1845          * If we were waiting for sends to complete before re-sending,
1846          * and they are now complete, restart sending.
1847          */
1848         trace_hfi1_sendcomplete(qp, psn);
1849         if (qp->s_flags & RVT_S_WAIT_PSN &&
1850             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1851                 qp->s_flags &= ~RVT_S_WAIT_PSN;
1852                 qp->s_sending_psn = qp->s_psn;
1853                 qp->s_sending_hpsn = qp->s_psn - 1;
1854                 hfi1_schedule_send(qp);
1855         }
1856 }
1857
1858 static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
1859 {
1860         qp->s_last_psn = psn;
1861 }
1862
1863 /*
1864  * Generate a SWQE completion.
1865  * This is similar to hfi1_send_complete but has to check to be sure
1866  * that the SGEs are not being referenced if the SWQE is being resent.
1867  */
1868 struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
1869                                   struct rvt_swqe *wqe,
1870                                   struct hfi1_ibport *ibp)
1871 {
1872         struct hfi1_qp_priv *priv = qp->priv;
1873
1874         lockdep_assert_held(&qp->s_lock);
1875         /*
1876          * Don't decrement refcount and don't generate a
1877          * completion if the SWQE is being resent until the send
1878          * is finished.
1879          */
1880         trace_hfi1_rc_completion(qp, wqe->lpsn);
1881         if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 ||
1882             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1883                 trdma_clean_swqe(qp, wqe);
1884                 trace_hfi1_qp_send_completion(qp, wqe, qp->s_last);
1885                 rvt_qp_complete_swqe(qp,
1886                                      wqe,
1887                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1888                                      IB_WC_SUCCESS);
1889         } else {
1890                 struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1891
1892                 this_cpu_inc(*ibp->rvp.rc_delayed_comp);
1893                 /*
1894                  * If send progress not running attempt to progress
1895                  * SDMA queue.
1896                  */
1897                 if (ppd->dd->flags & HFI1_HAS_SEND_DMA) {
1898                         struct sdma_engine *engine;
1899                         u8 sl = rdma_ah_get_sl(&qp->remote_ah_attr);
1900                         u8 sc5;
1901
1902                         /* For now use sc to find engine */
1903                         sc5 = ibp->sl_to_sc[sl];
1904                         engine = qp_to_sdma_engine(qp, sc5);
1905                         sdma_engine_progress_schedule(engine);
1906                 }
1907         }
1908
1909         qp->s_retry = qp->s_retry_cnt;
1910         /*
1911          * Don't update the last PSN if the request being completed is
1912          * a TID RDMA WRITE request.
1913          * Completion of the TID RDMA WRITE requests are done by the
1914          * TID RDMA ACKs and as such could be for a request that has
1915          * already been ACKed as far as the IB state machine is
1916          * concerned.
1917          */
1918         if (wqe->wr.opcode != IB_WR_TID_RDMA_WRITE)
1919                 update_last_psn(qp, wqe->lpsn);
1920
1921         /*
1922          * If we are completing a request which is in the process of
1923          * being resent, we can stop re-sending it since we know the
1924          * responder has already seen it.
1925          */
1926         if (qp->s_acked == qp->s_cur) {
1927                 if (++qp->s_cur >= qp->s_size)
1928                         qp->s_cur = 0;
1929                 qp->s_acked = qp->s_cur;
1930                 wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1931                 if (qp->s_acked != qp->s_tail) {
1932                         qp->s_state = OP(SEND_LAST);
1933                         qp->s_psn = wqe->psn;
1934                 }
1935         } else {
1936                 if (++qp->s_acked >= qp->s_size)
1937                         qp->s_acked = 0;
1938                 if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur)
1939                         qp->s_draining = 0;
1940                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1941         }
1942         if (priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) {
1943                 priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
1944                 hfi1_schedule_send(qp);
1945         }
1946         return wqe;
1947 }
1948
1949 static void set_restart_qp(struct rvt_qp *qp, struct hfi1_ctxtdata *rcd)
1950 {
1951         /* Retry this request. */
1952         if (!(qp->r_flags & RVT_R_RDMAR_SEQ)) {
1953                 qp->r_flags |= RVT_R_RDMAR_SEQ;
1954                 hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
1955                 if (list_empty(&qp->rspwait)) {
1956                         qp->r_flags |= RVT_R_RSP_SEND;
1957                         rvt_get_qp(qp);
1958                         list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1959                 }
1960         }
1961 }
1962
1963 /**
1964  * update_qp_retry_state - Update qp retry state.
1965  * @qp: the QP
1966  * @psn: the packet sequence number of the TID RDMA WRITE RESP.
1967  * @spsn:  The start psn for the given TID RDMA WRITE swqe.
1968  * @lpsn:  The last psn for the given TID RDMA WRITE swqe.
1969  *
1970  * This function is called to update the qp retry state upon
1971  * receiving a TID WRITE RESP after the qp is scheduled to retry
1972  * a request.
1973  */
1974 static void update_qp_retry_state(struct rvt_qp *qp, u32 psn, u32 spsn,
1975                                   u32 lpsn)
1976 {
1977         struct hfi1_qp_priv *qpriv = qp->priv;
1978
1979         qp->s_psn = psn + 1;
1980         /*
1981          * If this is the first TID RDMA WRITE RESP packet for the current
1982          * request, change the s_state so that the retry will be processed
1983          * correctly. Similarly, if this is the last TID RDMA WRITE RESP
1984          * packet, change the s_state and advance the s_cur.
1985          */
1986         if (cmp_psn(psn, lpsn) >= 0) {
1987                 qp->s_cur = qpriv->s_tid_cur + 1;
1988                 if (qp->s_cur >= qp->s_size)
1989                         qp->s_cur = 0;
1990                 qp->s_state = TID_OP(WRITE_REQ);
1991         } else  if (!cmp_psn(psn, spsn)) {
1992                 qp->s_cur = qpriv->s_tid_cur;
1993                 qp->s_state = TID_OP(WRITE_RESP);
1994         }
1995 }
1996
1997 /**
1998  * do_rc_ack - process an incoming RC ACK
1999  * @qp: the QP the ACK came in on
2000  * @psn: the packet sequence number of the ACK
2001  * @opcode: the opcode of the request that resulted in the ACK
2002  *
2003  * This is called from rc_rcv_resp() to process an incoming RC ACK
2004  * for the given QP.
2005  * May be called at interrupt level, with the QP s_lock held.
2006  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
2007  */
2008 int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
2009               u64 val, struct hfi1_ctxtdata *rcd)
2010 {
2011         struct hfi1_ibport *ibp;
2012         enum ib_wc_status status;
2013         struct hfi1_qp_priv *qpriv = qp->priv;
2014         struct rvt_swqe *wqe;
2015         int ret = 0;
2016         u32 ack_psn;
2017         int diff;
2018         struct rvt_dev_info *rdi;
2019
2020         lockdep_assert_held(&qp->s_lock);
2021         /*
2022          * Note that NAKs implicitly ACK outstanding SEND and RDMA write
2023          * requests and implicitly NAK RDMA read and atomic requests issued
2024          * before the NAK'ed request.  The MSN won't include the NAK'ed
2025          * request but will include an ACK'ed request(s).
2026          */
2027         ack_psn = psn;
2028         if (aeth >> IB_AETH_NAK_SHIFT)
2029                 ack_psn--;
2030         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2031         ibp = rcd_to_iport(rcd);
2032
2033         /*
2034          * The MSN might be for a later WQE than the PSN indicates so
2035          * only complete WQEs that the PSN finishes.
2036          */
2037         while ((diff = delta_psn(ack_psn, wqe->lpsn)) >= 0) {
2038                 /*
2039                  * RDMA_READ_RESPONSE_ONLY is a special case since
2040                  * we want to generate completion events for everything
2041                  * before the RDMA read, copy the data, then generate
2042                  * the completion for the read.
2043                  */
2044                 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
2045                     opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
2046                     diff == 0) {
2047                         ret = 1;
2048                         goto bail_stop;
2049                 }
2050                 /*
2051                  * If this request is a RDMA read or atomic, and the ACK is
2052                  * for a later operation, this ACK NAKs the RDMA read or
2053                  * atomic.  In other words, only a RDMA_READ_LAST or ONLY
2054                  * can ACK a RDMA read and likewise for atomic ops.  Note
2055                  * that the NAK case can only happen if relaxed ordering is
2056                  * used and requests are sent after an RDMA read or atomic
2057                  * is sent but before the response is received.
2058                  */
2059                 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
2060                      (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
2061                     (wqe->wr.opcode == IB_WR_TID_RDMA_READ &&
2062                      (opcode != TID_OP(READ_RESP) || diff != 0)) ||
2063                     ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2064                       wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
2065                      (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0)) ||
2066                     (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2067                      (delta_psn(psn, qp->s_last_psn) != 1))) {
2068                         set_restart_qp(qp, rcd);
2069                         /*
2070                          * No need to process the ACK/NAK since we are
2071                          * restarting an earlier request.
2072                          */
2073                         goto bail_stop;
2074                 }
2075                 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2076                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
2077                         u64 *vaddr = wqe->sg_list[0].vaddr;
2078                         *vaddr = val;
2079                 }
2080                 if (wqe->wr.opcode == IB_WR_OPFN)
2081                         opfn_conn_reply(qp, val);
2082
2083                 if (qp->s_num_rd_atomic &&
2084                     (wqe->wr.opcode == IB_WR_RDMA_READ ||
2085                      wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2086                      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
2087                         qp->s_num_rd_atomic--;
2088                         /* Restart sending task if fence is complete */
2089                         if ((qp->s_flags & RVT_S_WAIT_FENCE) &&
2090                             !qp->s_num_rd_atomic) {
2091                                 qp->s_flags &= ~(RVT_S_WAIT_FENCE |
2092                                                  RVT_S_WAIT_ACK);
2093                                 hfi1_schedule_send(qp);
2094                         } else if (qp->s_flags & RVT_S_WAIT_RDMAR) {
2095                                 qp->s_flags &= ~(RVT_S_WAIT_RDMAR |
2096                                                  RVT_S_WAIT_ACK);
2097                                 hfi1_schedule_send(qp);
2098                         }
2099                 }
2100
2101                 /*
2102                  * TID RDMA WRITE requests will be completed by the TID RDMA
2103                  * ACK packet handler (see tid_rdma.c).
2104                  */
2105                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
2106                         break;
2107
2108                 wqe = do_rc_completion(qp, wqe, ibp);
2109                 if (qp->s_acked == qp->s_tail)
2110                         break;
2111         }
2112
2113         trace_hfi1_rc_ack_do(qp, aeth, psn, wqe);
2114         trace_hfi1_sender_do_rc_ack(qp);
2115         switch (aeth >> IB_AETH_NAK_SHIFT) {
2116         case 0:         /* ACK */
2117                 this_cpu_inc(*ibp->rvp.rc_acks);
2118                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ) {
2119                         if (wqe_to_tid_req(wqe)->ack_pending)
2120                                 rvt_mod_retry_timer_ext(qp,
2121                                                         qpriv->timeout_shift);
2122                         else
2123                                 rvt_stop_rc_timers(qp);
2124                 } else if (qp->s_acked != qp->s_tail) {
2125                         struct rvt_swqe *__w = NULL;
2126
2127                         if (qpriv->s_tid_cur != HFI1_QP_WQE_INVALID)
2128                                 __w = rvt_get_swqe_ptr(qp, qpriv->s_tid_cur);
2129
2130                         /*
2131                          * Stop timers if we've received all of the TID RDMA
2132                          * WRITE * responses.
2133                          */
2134                         if (__w && __w->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2135                             opcode == TID_OP(WRITE_RESP)) {
2136                                 /*
2137                                  * Normally, the loop above would correctly
2138                                  * process all WQEs from s_acked onward and
2139                                  * either complete them or check for correct
2140                                  * PSN sequencing.
2141                                  * However, for TID RDMA, due to pipelining,
2142                                  * the response may not be for the request at
2143                                  * s_acked so the above look would just be
2144                                  * skipped. This does not allow for checking
2145                                  * the PSN sequencing. It has to be done
2146                                  * separately.
2147                                  */
2148                                 if (cmp_psn(psn, qp->s_last_psn + 1)) {
2149                                         set_restart_qp(qp, rcd);
2150                                         goto bail_stop;
2151                                 }
2152                                 /*
2153                                  * If the psn is being resent, stop the
2154                                  * resending.
2155                                  */
2156                                 if (qp->s_cur != qp->s_tail &&
2157                                     cmp_psn(qp->s_psn, psn) <= 0)
2158                                         update_qp_retry_state(qp, psn,
2159                                                               __w->psn,
2160                                                               __w->lpsn);
2161                                 else if (--qpriv->pending_tid_w_resp)
2162                                         rvt_mod_retry_timer(qp);
2163                                 else
2164                                         rvt_stop_rc_timers(qp);
2165                         } else {
2166                                 /*
2167                                  * We are expecting more ACKs so
2168                                  * mod the retry timer.
2169                                  */
2170                                 rvt_mod_retry_timer(qp);
2171                                 /*
2172                                  * We can stop re-sending the earlier packets
2173                                  * and continue with the next packet the
2174                                  * receiver wants.
2175                                  */
2176                                 if (cmp_psn(qp->s_psn, psn) <= 0)
2177                                         reset_psn(qp, psn + 1);
2178                         }
2179                 } else {
2180                         /* No more acks - kill all timers */
2181                         rvt_stop_rc_timers(qp);
2182                         if (cmp_psn(qp->s_psn, psn) <= 0) {
2183                                 qp->s_state = OP(SEND_LAST);
2184                                 qp->s_psn = psn + 1;
2185                         }
2186                 }
2187                 if (qp->s_flags & RVT_S_WAIT_ACK) {
2188                         qp->s_flags &= ~RVT_S_WAIT_ACK;
2189                         hfi1_schedule_send(qp);
2190                 }
2191                 rvt_get_credit(qp, aeth);
2192                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
2193                 qp->s_retry = qp->s_retry_cnt;
2194                 /*
2195                  * If the current request is a TID RDMA WRITE request and the
2196                  * response is not a TID RDMA WRITE RESP packet, s_last_psn
2197                  * can't be advanced.
2198                  */
2199                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2200                     opcode != TID_OP(WRITE_RESP) &&
2201                     cmp_psn(psn, wqe->psn) >= 0)
2202                         return 1;
2203                 update_last_psn(qp, psn);
2204                 return 1;
2205
2206         case 1:         /* RNR NAK */
2207                 ibp->rvp.n_rnr_naks++;
2208                 if (qp->s_acked == qp->s_tail)
2209                         goto bail_stop;
2210                 if (qp->s_flags & RVT_S_WAIT_RNR)
2211                         goto bail_stop;
2212                 rdi = ib_to_rvt(qp->ibqp.device);
2213                 if (qp->s_rnr_retry == 0 &&
2214                     !((rdi->post_parms[wqe->wr.opcode].flags &
2215                       RVT_OPERATION_IGN_RNR_CNT) &&
2216                       qp->s_rnr_retry_cnt == 0)) {
2217                         status = IB_WC_RNR_RETRY_EXC_ERR;
2218                         goto class_b;
2219                 }
2220                 if (qp->s_rnr_retry_cnt < 7 && qp->s_rnr_retry_cnt > 0)
2221                         qp->s_rnr_retry--;
2222
2223                 /*
2224                  * The last valid PSN is the previous PSN. For TID RDMA WRITE
2225                  * request, s_last_psn should be incremented only when a TID
2226                  * RDMA WRITE RESP is received to avoid skipping lost TID RDMA
2227                  * WRITE RESP packets.
2228                  */
2229                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE) {
2230                         reset_psn(qp, qp->s_last_psn + 1);
2231                 } else {
2232                         update_last_psn(qp, psn - 1);
2233                         reset_psn(qp, psn);
2234                 }
2235
2236                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
2237                 qp->s_flags &= ~(RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_ACK);
2238                 rvt_stop_rc_timers(qp);
2239                 rvt_add_rnr_timer(qp, aeth);
2240                 return 0;
2241
2242         case 3:         /* NAK */
2243                 if (qp->s_acked == qp->s_tail)
2244                         goto bail_stop;
2245                 /* The last valid PSN is the previous PSN. */
2246                 update_last_psn(qp, psn - 1);
2247                 switch ((aeth >> IB_AETH_CREDIT_SHIFT) &
2248                         IB_AETH_CREDIT_MASK) {
2249                 case 0: /* PSN sequence error */
2250                         ibp->rvp.n_seq_naks++;
2251                         /*
2252                          * Back up to the responder's expected PSN.
2253                          * Note that we might get a NAK in the middle of an
2254                          * RDMA READ response which terminates the RDMA
2255                          * READ.
2256                          */
2257                         hfi1_restart_rc(qp, psn, 0);
2258                         hfi1_schedule_send(qp);
2259                         break;
2260
2261                 case 1: /* Invalid Request */
2262                         status = IB_WC_REM_INV_REQ_ERR;
2263                         ibp->rvp.n_other_naks++;
2264                         goto class_b;
2265
2266                 case 2: /* Remote Access Error */
2267                         status = IB_WC_REM_ACCESS_ERR;
2268                         ibp->rvp.n_other_naks++;
2269                         goto class_b;
2270
2271                 case 3: /* Remote Operation Error */
2272                         status = IB_WC_REM_OP_ERR;
2273                         ibp->rvp.n_other_naks++;
2274 class_b:
2275                         if (qp->s_last == qp->s_acked) {
2276                                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ)
2277                                         hfi1_kern_read_tid_flow_free(qp);
2278
2279                                 hfi1_trdma_send_complete(qp, wqe, status);
2280                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
2281                         }
2282                         break;
2283
2284                 default:
2285                         /* Ignore other reserved NAK error codes */
2286                         goto reserved;
2287                 }
2288                 qp->s_retry = qp->s_retry_cnt;
2289                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
2290                 goto bail_stop;
2291
2292         default:                /* 2: reserved */
2293 reserved:
2294                 /* Ignore reserved NAK codes. */
2295                 goto bail_stop;
2296         }
2297         /* cannot be reached  */
2298 bail_stop:
2299         rvt_stop_rc_timers(qp);
2300         return ret;
2301 }
2302
2303 /*
2304  * We have seen an out of sequence RDMA read middle or last packet.
2305  * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE.
2306  */
2307 static void rdma_seq_err(struct rvt_qp *qp, struct hfi1_ibport *ibp, u32 psn,
2308                          struct hfi1_ctxtdata *rcd)
2309 {
2310         struct rvt_swqe *wqe;
2311
2312         lockdep_assert_held(&qp->s_lock);
2313         /* Remove QP from retry timer */
2314         rvt_stop_rc_timers(qp);
2315
2316         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2317
2318         while (cmp_psn(psn, wqe->lpsn) > 0) {
2319                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
2320                     wqe->wr.opcode == IB_WR_TID_RDMA_READ ||
2321                     wqe->wr.opcode == IB_WR_TID_RDMA_WRITE ||
2322                     wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2323                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
2324                         break;
2325                 wqe = do_rc_completion(qp, wqe, ibp);
2326         }
2327
2328         ibp->rvp.n_rdma_seq++;
2329         qp->r_flags |= RVT_R_RDMAR_SEQ;
2330         hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
2331         if (list_empty(&qp->rspwait)) {
2332                 qp->r_flags |= RVT_R_RSP_SEND;
2333                 rvt_get_qp(qp);
2334                 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
2335         }
2336 }
2337
2338 /**
2339  * rc_rcv_resp - process an incoming RC response packet
2340  * @packet: data packet information
2341  *
2342  * This is called from hfi1_rc_rcv() to process an incoming RC response
2343  * packet for the given QP.
2344  * Called at interrupt level.
2345  */
2346 static void rc_rcv_resp(struct hfi1_packet *packet)
2347 {
2348         struct hfi1_ctxtdata *rcd = packet->rcd;
2349         void *data = packet->payload;
2350         u32 tlen = packet->tlen;
2351         struct rvt_qp *qp = packet->qp;
2352         struct hfi1_ibport *ibp;
2353         struct ib_other_headers *ohdr = packet->ohdr;
2354         struct rvt_swqe *wqe;
2355         enum ib_wc_status status;
2356         unsigned long flags;
2357         int diff;
2358         u64 val;
2359         u32 aeth;
2360         u32 psn = ib_bth_get_psn(packet->ohdr);
2361         u32 pmtu = qp->pmtu;
2362         u16 hdrsize = packet->hlen;
2363         u8 opcode = packet->opcode;
2364         u8 pad = packet->pad;
2365         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
2366
2367         spin_lock_irqsave(&qp->s_lock, flags);
2368         trace_hfi1_ack(qp, psn);
2369
2370         /* Ignore invalid responses. */
2371         if (cmp_psn(psn, READ_ONCE(qp->s_next_psn)) >= 0)
2372                 goto ack_done;
2373
2374         /* Ignore duplicate responses. */
2375         diff = cmp_psn(psn, qp->s_last_psn);
2376         if (unlikely(diff <= 0)) {
2377                 /* Update credits for "ghost" ACKs */
2378                 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
2379                         aeth = be32_to_cpu(ohdr->u.aeth);
2380                         if ((aeth >> IB_AETH_NAK_SHIFT) == 0)
2381                                 rvt_get_credit(qp, aeth);
2382                 }
2383                 goto ack_done;
2384         }
2385
2386         /*
2387          * Skip everything other than the PSN we expect, if we are waiting
2388          * for a reply to a restarted RDMA read or atomic op.
2389          */
2390         if (qp->r_flags & RVT_R_RDMAR_SEQ) {
2391                 if (cmp_psn(psn, qp->s_last_psn + 1) != 0)
2392                         goto ack_done;
2393                 qp->r_flags &= ~RVT_R_RDMAR_SEQ;
2394         }
2395
2396         if (unlikely(qp->s_acked == qp->s_tail))
2397                 goto ack_done;
2398         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2399         status = IB_WC_SUCCESS;
2400
2401         switch (opcode) {
2402         case OP(ACKNOWLEDGE):
2403         case OP(ATOMIC_ACKNOWLEDGE):
2404         case OP(RDMA_READ_RESPONSE_FIRST):
2405                 aeth = be32_to_cpu(ohdr->u.aeth);
2406                 if (opcode == OP(ATOMIC_ACKNOWLEDGE))
2407                         val = ib_u64_get(&ohdr->u.at.atomic_ack_eth);
2408                 else
2409                         val = 0;
2410                 if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) ||
2411                     opcode != OP(RDMA_READ_RESPONSE_FIRST))
2412                         goto ack_done;
2413                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2414                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2415                         goto ack_op_err;
2416                 /*
2417                  * If this is a response to a resent RDMA read, we
2418                  * have to be careful to copy the data to the right
2419                  * location.
2420                  */
2421                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
2422                                                   wqe, psn, pmtu);
2423                 goto read_middle;
2424
2425         case OP(RDMA_READ_RESPONSE_MIDDLE):
2426                 /* no AETH, no ACK */
2427                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
2428                         goto ack_seq_err;
2429                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2430                         goto ack_op_err;
2431 read_middle:
2432                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
2433                         goto ack_len_err;
2434                 if (unlikely(pmtu >= qp->s_rdma_read_len))
2435                         goto ack_len_err;
2436
2437                 /*
2438                  * We got a response so update the timeout.
2439                  * 4.096 usec. * (1 << qp->timeout)
2440                  */
2441                 rvt_mod_retry_timer(qp);
2442                 if (qp->s_flags & RVT_S_WAIT_ACK) {
2443                         qp->s_flags &= ~RVT_S_WAIT_ACK;
2444                         hfi1_schedule_send(qp);
2445                 }
2446
2447                 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
2448                         qp->s_retry = qp->s_retry_cnt;
2449
2450                 /*
2451                  * Update the RDMA receive state but do the copy w/o
2452                  * holding the locks and blocking interrupts.
2453                  */
2454                 qp->s_rdma_read_len -= pmtu;
2455                 update_last_psn(qp, psn);
2456                 spin_unlock_irqrestore(&qp->s_lock, flags);
2457                 rvt_copy_sge(qp, &qp->s_rdma_read_sge,
2458                              data, pmtu, false, false);
2459                 goto bail;
2460
2461         case OP(RDMA_READ_RESPONSE_ONLY):
2462                 aeth = be32_to_cpu(ohdr->u.aeth);
2463                 if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd))
2464                         goto ack_done;
2465                 /*
2466                  * Check that the data size is >= 0 && <= pmtu.
2467                  * Remember to account for ICRC (4).
2468                  */
2469                 if (unlikely(tlen < (hdrsize + extra_bytes)))
2470                         goto ack_len_err;
2471                 /*
2472                  * If this is a response to a resent RDMA read, we
2473                  * have to be careful to copy the data to the right
2474                  * location.
2475                  */
2476                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2477                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
2478                                                   wqe, psn, pmtu);
2479                 goto read_last;
2480
2481         case OP(RDMA_READ_RESPONSE_LAST):
2482                 /* ACKs READ req. */
2483                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
2484                         goto ack_seq_err;
2485                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2486                         goto ack_op_err;
2487                 /*
2488                  * Check that the data size is >= 1 && <= pmtu.
2489                  * Remember to account for ICRC (4).
2490                  */
2491                 if (unlikely(tlen <= (hdrsize + extra_bytes)))
2492                         goto ack_len_err;
2493 read_last:
2494                 tlen -= hdrsize + extra_bytes;
2495                 if (unlikely(tlen != qp->s_rdma_read_len))
2496                         goto ack_len_err;
2497                 aeth = be32_to_cpu(ohdr->u.aeth);
2498                 rvt_copy_sge(qp, &qp->s_rdma_read_sge,
2499                              data, tlen, false, false);
2500                 WARN_ON(qp->s_rdma_read_sge.num_sge);
2501                 (void)do_rc_ack(qp, aeth, psn,
2502                                  OP(RDMA_READ_RESPONSE_LAST), 0, rcd);
2503                 goto ack_done;
2504         }
2505
2506 ack_op_err:
2507         status = IB_WC_LOC_QP_OP_ERR;
2508         goto ack_err;
2509
2510 ack_seq_err:
2511         ibp = rcd_to_iport(rcd);
2512         rdma_seq_err(qp, ibp, psn, rcd);
2513         goto ack_done;
2514
2515 ack_len_err:
2516         status = IB_WC_LOC_LEN_ERR;
2517 ack_err:
2518         if (qp->s_last == qp->s_acked) {
2519                 rvt_send_complete(qp, wqe, status);
2520                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
2521         }
2522 ack_done:
2523         spin_unlock_irqrestore(&qp->s_lock, flags);
2524 bail:
2525         return;
2526 }
2527
2528 static inline void rc_cancel_ack(struct rvt_qp *qp)
2529 {
2530         qp->r_adefered = 0;
2531         if (list_empty(&qp->rspwait))
2532                 return;
2533         list_del_init(&qp->rspwait);
2534         qp->r_flags &= ~RVT_R_RSP_NAK;
2535         rvt_put_qp(qp);
2536 }
2537
2538 /**
2539  * rc_rcv_error - process an incoming duplicate or error RC packet
2540  * @ohdr: the other headers for this packet
2541  * @data: the packet data
2542  * @qp: the QP for this packet
2543  * @opcode: the opcode for this packet
2544  * @psn: the packet sequence number for this packet
2545  * @diff: the difference between the PSN and the expected PSN
2546  *
2547  * This is called from hfi1_rc_rcv() to process an unexpected
2548  * incoming RC packet for the given QP.
2549  * Called at interrupt level.
2550  * Return 1 if no more processing is needed; otherwise return 0 to
2551  * schedule a response to be sent.
2552  */
2553 static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
2554                                  struct rvt_qp *qp, u32 opcode, u32 psn,
2555                                  int diff, struct hfi1_ctxtdata *rcd)
2556 {
2557         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2558         struct rvt_ack_entry *e;
2559         unsigned long flags;
2560         u8 prev;
2561         u8 mra; /* most recent ACK */
2562         bool old_req;
2563
2564         trace_hfi1_rcv_error(qp, psn);
2565         if (diff > 0) {
2566                 /*
2567                  * Packet sequence error.
2568                  * A NAK will ACK earlier sends and RDMA writes.
2569                  * Don't queue the NAK if we already sent one.
2570                  */
2571                 if (!qp->r_nak_state) {
2572                         ibp->rvp.n_rc_seqnak++;
2573                         qp->r_nak_state = IB_NAK_PSN_ERROR;
2574                         /* Use the expected PSN. */
2575                         qp->r_ack_psn = qp->r_psn;
2576                         /*
2577                          * Wait to send the sequence NAK until all packets
2578                          * in the receive queue have been processed.
2579                          * Otherwise, we end up propagating congestion.
2580                          */
2581                         rc_defered_ack(rcd, qp);
2582                 }
2583                 goto done;
2584         }
2585
2586         /*
2587          * Handle a duplicate request.  Don't re-execute SEND, RDMA
2588          * write or atomic op.  Don't NAK errors, just silently drop
2589          * the duplicate request.  Note that r_sge, r_len, and
2590          * r_rcv_len may be in use so don't modify them.
2591          *
2592          * We are supposed to ACK the earliest duplicate PSN but we
2593          * can coalesce an outstanding duplicate ACK.  We have to
2594          * send the earliest so that RDMA reads can be restarted at
2595          * the requester's expected PSN.
2596          *
2597          * First, find where this duplicate PSN falls within the
2598          * ACKs previously sent.
2599          * old_req is true if there is an older response that is scheduled
2600          * to be sent before sending this one.
2601          */
2602         e = NULL;
2603         old_req = 1;
2604         ibp->rvp.n_rc_dupreq++;
2605
2606         spin_lock_irqsave(&qp->s_lock, flags);
2607
2608         e = find_prev_entry(qp, psn, &prev, &mra, &old_req);
2609
2610         switch (opcode) {
2611         case OP(RDMA_READ_REQUEST): {
2612                 struct ib_reth *reth;
2613                 u32 offset;
2614                 u32 len;
2615
2616                 /*
2617                  * If we didn't find the RDMA read request in the ack queue,
2618                  * we can ignore this request.
2619                  */
2620                 if (!e || e->opcode != OP(RDMA_READ_REQUEST))
2621                         goto unlock_done;
2622                 /* RETH comes after BTH */
2623                 reth = &ohdr->u.rc.reth;
2624                 /*
2625                  * Address range must be a subset of the original
2626                  * request and start on pmtu boundaries.
2627                  * We reuse the old ack_queue slot since the requester
2628                  * should not back up and request an earlier PSN for the
2629                  * same request.
2630                  */
2631                 offset = delta_psn(psn, e->psn) * qp->pmtu;
2632                 len = be32_to_cpu(reth->length);
2633                 if (unlikely(offset + len != e->rdma_sge.sge_length))
2634                         goto unlock_done;
2635                 release_rdma_sge_mr(e);
2636                 if (len != 0) {
2637                         u32 rkey = be32_to_cpu(reth->rkey);
2638                         u64 vaddr = get_ib_reth_vaddr(reth);
2639                         int ok;
2640
2641                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
2642                                          IB_ACCESS_REMOTE_READ);
2643                         if (unlikely(!ok))
2644                                 goto unlock_done;
2645                 } else {
2646                         e->rdma_sge.vaddr = NULL;
2647                         e->rdma_sge.length = 0;
2648                         e->rdma_sge.sge_length = 0;
2649                 }
2650                 e->psn = psn;
2651                 if (old_req)
2652                         goto unlock_done;
2653                 if (qp->s_acked_ack_queue == qp->s_tail_ack_queue)
2654                         qp->s_acked_ack_queue = prev;
2655                 qp->s_tail_ack_queue = prev;
2656                 break;
2657         }
2658
2659         case OP(COMPARE_SWAP):
2660         case OP(FETCH_ADD): {
2661                 /*
2662                  * If we didn't find the atomic request in the ack queue
2663                  * or the send engine is already backed up to send an
2664                  * earlier entry, we can ignore this request.
2665                  */
2666                 if (!e || e->opcode != (u8)opcode || old_req)
2667                         goto unlock_done;
2668                 if (qp->s_tail_ack_queue == qp->s_acked_ack_queue)
2669                         qp->s_acked_ack_queue = prev;
2670                 qp->s_tail_ack_queue = prev;
2671                 break;
2672         }
2673
2674         default:
2675                 /*
2676                  * Ignore this operation if it doesn't request an ACK
2677                  * or an earlier RDMA read or atomic is going to be resent.
2678                  */
2679                 if (!(psn & IB_BTH_REQ_ACK) || old_req)
2680                         goto unlock_done;
2681                 /*
2682                  * Resend the most recent ACK if this request is
2683                  * after all the previous RDMA reads and atomics.
2684                  */
2685                 if (mra == qp->r_head_ack_queue) {
2686                         spin_unlock_irqrestore(&qp->s_lock, flags);
2687                         qp->r_nak_state = 0;
2688                         qp->r_ack_psn = qp->r_psn - 1;
2689                         goto send_ack;
2690                 }
2691
2692                 /*
2693                  * Resend the RDMA read or atomic op which
2694                  * ACKs this duplicate request.
2695                  */
2696                 if (qp->s_tail_ack_queue == qp->s_acked_ack_queue)
2697                         qp->s_acked_ack_queue = mra;
2698                 qp->s_tail_ack_queue = mra;
2699                 break;
2700         }
2701         qp->s_ack_state = OP(ACKNOWLEDGE);
2702         qp->s_flags |= RVT_S_RESP_PENDING;
2703         qp->r_nak_state = 0;
2704         hfi1_schedule_send(qp);
2705
2706 unlock_done:
2707         spin_unlock_irqrestore(&qp->s_lock, flags);
2708 done:
2709         return 1;
2710
2711 send_ack:
2712         return 0;
2713 }
2714
2715 static void log_cca_event(struct hfi1_pportdata *ppd, u8 sl, u32 rlid,
2716                           u32 lqpn, u32 rqpn, u8 svc_type)
2717 {
2718         struct opa_hfi1_cong_log_event_internal *cc_event;
2719         unsigned long flags;
2720
2721         if (sl >= OPA_MAX_SLS)
2722                 return;
2723
2724         spin_lock_irqsave(&ppd->cc_log_lock, flags);
2725
2726         ppd->threshold_cong_event_map[sl / 8] |= 1 << (sl % 8);
2727         ppd->threshold_event_counter++;
2728
2729         cc_event = &ppd->cc_events[ppd->cc_log_idx++];
2730         if (ppd->cc_log_idx == OPA_CONG_LOG_ELEMS)
2731                 ppd->cc_log_idx = 0;
2732         cc_event->lqpn = lqpn & RVT_QPN_MASK;
2733         cc_event->rqpn = rqpn & RVT_QPN_MASK;
2734         cc_event->sl = sl;
2735         cc_event->svc_type = svc_type;
2736         cc_event->rlid = rlid;
2737         /* keep timestamp in units of 1.024 usec */
2738         cc_event->timestamp = ktime_get_ns() / 1024;
2739
2740         spin_unlock_irqrestore(&ppd->cc_log_lock, flags);
2741 }
2742
2743 void process_becn(struct hfi1_pportdata *ppd, u8 sl, u32 rlid, u32 lqpn,
2744                   u32 rqpn, u8 svc_type)
2745 {
2746         struct cca_timer *cca_timer;
2747         u16 ccti, ccti_incr, ccti_timer, ccti_limit;
2748         u8 trigger_threshold;
2749         struct cc_state *cc_state;
2750         unsigned long flags;
2751
2752         if (sl >= OPA_MAX_SLS)
2753                 return;
2754
2755         cc_state = get_cc_state(ppd);
2756
2757         if (!cc_state)
2758                 return;
2759
2760         /*
2761          * 1) increase CCTI (for this SL)
2762          * 2) select IPG (i.e., call set_link_ipg())
2763          * 3) start timer
2764          */
2765         ccti_limit = cc_state->cct.ccti_limit;
2766         ccti_incr = cc_state->cong_setting.entries[sl].ccti_increase;
2767         ccti_timer = cc_state->cong_setting.entries[sl].ccti_timer;
2768         trigger_threshold =
2769                 cc_state->cong_setting.entries[sl].trigger_threshold;
2770
2771         spin_lock_irqsave(&ppd->cca_timer_lock, flags);
2772
2773         cca_timer = &ppd->cca_timer[sl];
2774         if (cca_timer->ccti < ccti_limit) {
2775                 if (cca_timer->ccti + ccti_incr <= ccti_limit)
2776                         cca_timer->ccti += ccti_incr;
2777                 else
2778                         cca_timer->ccti = ccti_limit;
2779                 set_link_ipg(ppd);
2780         }
2781
2782         ccti = cca_timer->ccti;
2783
2784         if (!hrtimer_active(&cca_timer->hrtimer)) {
2785                 /* ccti_timer is in units of 1.024 usec */
2786                 unsigned long nsec = 1024 * ccti_timer;
2787
2788                 hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec),
2789                               HRTIMER_MODE_REL_PINNED);
2790         }
2791
2792         spin_unlock_irqrestore(&ppd->cca_timer_lock, flags);
2793
2794         if ((trigger_threshold != 0) && (ccti >= trigger_threshold))
2795                 log_cca_event(ppd, sl, rlid, lqpn, rqpn, svc_type);
2796 }
2797
2798 /**
2799  * hfi1_rc_rcv - process an incoming RC packet
2800  * @packet: data packet information
2801  *
2802  * This is called from qp_rcv() to process an incoming RC packet
2803  * for the given QP.
2804  * May be called at interrupt level.
2805  */
2806 void hfi1_rc_rcv(struct hfi1_packet *packet)
2807 {
2808         struct hfi1_ctxtdata *rcd = packet->rcd;
2809         void *data = packet->payload;
2810         u32 tlen = packet->tlen;
2811         struct rvt_qp *qp = packet->qp;
2812         struct hfi1_qp_priv *qpriv = qp->priv;
2813         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2814         struct ib_other_headers *ohdr = packet->ohdr;
2815         u32 opcode = packet->opcode;
2816         u32 hdrsize = packet->hlen;
2817         u32 psn = ib_bth_get_psn(packet->ohdr);
2818         u32 pad = packet->pad;
2819         struct ib_wc wc;
2820         u32 pmtu = qp->pmtu;
2821         int diff;
2822         struct ib_reth *reth;
2823         unsigned long flags;
2824         int ret;
2825         bool copy_last = false, fecn;
2826         u32 rkey;
2827         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
2828
2829         lockdep_assert_held(&qp->r_lock);
2830
2831         if (hfi1_ruc_check_hdr(ibp, packet))
2832                 return;
2833
2834         fecn = process_ecn(qp, packet);
2835         opfn_trigger_conn_request(qp, be32_to_cpu(ohdr->bth[1]));
2836
2837         /*
2838          * Process responses (ACKs) before anything else.  Note that the
2839          * packet sequence number will be for something in the send work
2840          * queue rather than the expected receive packet sequence number.
2841          * In other words, this QP is the requester.
2842          */
2843         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
2844             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
2845                 rc_rcv_resp(packet);
2846                 return;
2847         }
2848
2849         /* Compute 24 bits worth of difference. */
2850         diff = delta_psn(psn, qp->r_psn);
2851         if (unlikely(diff)) {
2852                 if (rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd))
2853                         return;
2854                 goto send_ack;
2855         }
2856
2857         /* Check for opcode sequence errors. */
2858         switch (qp->r_state) {
2859         case OP(SEND_FIRST):
2860         case OP(SEND_MIDDLE):
2861                 if (opcode == OP(SEND_MIDDLE) ||
2862                     opcode == OP(SEND_LAST) ||
2863                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2864                     opcode == OP(SEND_LAST_WITH_INVALIDATE))
2865                         break;
2866                 goto nack_inv;
2867
2868         case OP(RDMA_WRITE_FIRST):
2869         case OP(RDMA_WRITE_MIDDLE):
2870                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
2871                     opcode == OP(RDMA_WRITE_LAST) ||
2872                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2873                         break;
2874                 goto nack_inv;
2875
2876         default:
2877                 if (opcode == OP(SEND_MIDDLE) ||
2878                     opcode == OP(SEND_LAST) ||
2879                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2880                     opcode == OP(SEND_LAST_WITH_INVALIDATE) ||
2881                     opcode == OP(RDMA_WRITE_MIDDLE) ||
2882                     opcode == OP(RDMA_WRITE_LAST) ||
2883                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2884                         goto nack_inv;
2885                 /*
2886                  * Note that it is up to the requester to not send a new
2887                  * RDMA read or atomic operation before receiving an ACK
2888                  * for the previous operation.
2889                  */
2890                 break;
2891         }
2892
2893         if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
2894                 rvt_comm_est(qp);
2895
2896         /* OK, process the packet. */
2897         switch (opcode) {
2898         case OP(SEND_FIRST):
2899                 ret = rvt_get_rwqe(qp, false);
2900                 if (ret < 0)
2901                         goto nack_op_err;
2902                 if (!ret)
2903                         goto rnr_nak;
2904                 qp->r_rcv_len = 0;
2905                 /* FALLTHROUGH */
2906         case OP(SEND_MIDDLE):
2907         case OP(RDMA_WRITE_MIDDLE):
2908 send_middle:
2909                 /* Check for invalid length PMTU or posted rwqe len. */
2910                 /*
2911                  * There will be no padding for 9B packet but 16B packets
2912                  * will come in with some padding since we always add
2913                  * CRC and LT bytes which will need to be flit aligned
2914                  */
2915                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
2916                         goto nack_inv;
2917                 qp->r_rcv_len += pmtu;
2918                 if (unlikely(qp->r_rcv_len > qp->r_len))
2919                         goto nack_inv;
2920                 rvt_copy_sge(qp, &qp->r_sge, data, pmtu, true, false);
2921                 break;
2922
2923         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
2924                 /* consume RWQE */
2925                 ret = rvt_get_rwqe(qp, true);
2926                 if (ret < 0)
2927                         goto nack_op_err;
2928                 if (!ret)
2929                         goto rnr_nak;
2930                 goto send_last_imm;
2931
2932         case OP(SEND_ONLY):
2933         case OP(SEND_ONLY_WITH_IMMEDIATE):
2934         case OP(SEND_ONLY_WITH_INVALIDATE):
2935                 ret = rvt_get_rwqe(qp, false);
2936                 if (ret < 0)
2937                         goto nack_op_err;
2938                 if (!ret)
2939                         goto rnr_nak;
2940                 qp->r_rcv_len = 0;
2941                 if (opcode == OP(SEND_ONLY))
2942                         goto no_immediate_data;
2943                 if (opcode == OP(SEND_ONLY_WITH_INVALIDATE))
2944                         goto send_last_inv;
2945                 /* FALLTHROUGH -- for SEND_ONLY_WITH_IMMEDIATE */
2946         case OP(SEND_LAST_WITH_IMMEDIATE):
2947 send_last_imm:
2948                 wc.ex.imm_data = ohdr->u.imm_data;
2949                 wc.wc_flags = IB_WC_WITH_IMM;
2950                 goto send_last;
2951         case OP(SEND_LAST_WITH_INVALIDATE):
2952 send_last_inv:
2953                 rkey = be32_to_cpu(ohdr->u.ieth);
2954                 if (rvt_invalidate_rkey(qp, rkey))
2955                         goto no_immediate_data;
2956                 wc.ex.invalidate_rkey = rkey;
2957                 wc.wc_flags = IB_WC_WITH_INVALIDATE;
2958                 goto send_last;
2959         case OP(RDMA_WRITE_LAST):
2960                 copy_last = rvt_is_user_qp(qp);
2961                 /* fall through */
2962         case OP(SEND_LAST):
2963 no_immediate_data:
2964                 wc.wc_flags = 0;
2965                 wc.ex.imm_data = 0;
2966 send_last:
2967                 /* Check for invalid length. */
2968                 /* LAST len should be >= 1 */
2969                 if (unlikely(tlen < (hdrsize + extra_bytes)))
2970                         goto nack_inv;
2971                 /* Don't count the CRC(and padding and LT byte for 16B). */
2972                 tlen -= (hdrsize + extra_bytes);
2973                 wc.byte_len = tlen + qp->r_rcv_len;
2974                 if (unlikely(wc.byte_len > qp->r_len))
2975                         goto nack_inv;
2976                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, copy_last);
2977                 rvt_put_ss(&qp->r_sge);
2978                 qp->r_msn++;
2979                 if (!__test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
2980                         break;
2981                 wc.wr_id = qp->r_wr_id;
2982                 wc.status = IB_WC_SUCCESS;
2983                 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
2984                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
2985                         wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
2986                 else
2987                         wc.opcode = IB_WC_RECV;
2988                 wc.qp = &qp->ibqp;
2989                 wc.src_qp = qp->remote_qpn;
2990                 wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
2991                 /*
2992                  * It seems that IB mandates the presence of an SL in a
2993                  * work completion only for the UD transport (see section
2994                  * 11.4.2 of IBTA Vol. 1).
2995                  *
2996                  * However, the way the SL is chosen below is consistent
2997                  * with the way that IB/qib works and is trying avoid
2998                  * introducing incompatibilities.
2999                  *
3000                  * See also OPA Vol. 1, section 9.7.6, and table 9-17.
3001                  */
3002                 wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
3003                 /* zero fields that are N/A */
3004                 wc.vendor_err = 0;
3005                 wc.pkey_index = 0;
3006                 wc.dlid_path_bits = 0;
3007                 wc.port_num = 0;
3008                 /* Signal completion event if the solicited bit is set. */
3009                 rvt_recv_cq(qp, &wc, ib_bth_is_solicited(ohdr));
3010                 break;
3011
3012         case OP(RDMA_WRITE_ONLY):
3013                 copy_last = rvt_is_user_qp(qp);
3014                 /* fall through */
3015         case OP(RDMA_WRITE_FIRST):
3016         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
3017                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
3018                         goto nack_inv;
3019                 /* consume RWQE */
3020                 reth = &ohdr->u.rc.reth;
3021                 qp->r_len = be32_to_cpu(reth->length);
3022                 qp->r_rcv_len = 0;
3023                 qp->r_sge.sg_list = NULL;
3024                 if (qp->r_len != 0) {
3025                         u32 rkey = be32_to_cpu(reth->rkey);
3026                         u64 vaddr = get_ib_reth_vaddr(reth);
3027                         int ok;
3028
3029                         /* Check rkey & NAK */
3030                         ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr,
3031                                          rkey, IB_ACCESS_REMOTE_WRITE);
3032                         if (unlikely(!ok))
3033                                 goto nack_acc;
3034                         qp->r_sge.num_sge = 1;
3035                 } else {
3036                         qp->r_sge.num_sge = 0;
3037                         qp->r_sge.sge.mr = NULL;
3038                         qp->r_sge.sge.vaddr = NULL;
3039                         qp->r_sge.sge.length = 0;
3040                         qp->r_sge.sge.sge_length = 0;
3041                 }
3042                 if (opcode == OP(RDMA_WRITE_FIRST))
3043                         goto send_middle;
3044                 else if (opcode == OP(RDMA_WRITE_ONLY))
3045                         goto no_immediate_data;
3046                 ret = rvt_get_rwqe(qp, true);
3047                 if (ret < 0)
3048                         goto nack_op_err;
3049                 if (!ret) {
3050                         /* peer will send again */
3051                         rvt_put_ss(&qp->r_sge);
3052                         goto rnr_nak;
3053                 }
3054                 wc.ex.imm_data = ohdr->u.rc.imm_data;
3055                 wc.wc_flags = IB_WC_WITH_IMM;
3056                 goto send_last;
3057
3058         case OP(RDMA_READ_REQUEST): {
3059                 struct rvt_ack_entry *e;
3060                 u32 len;
3061                 u8 next;
3062
3063                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
3064                         goto nack_inv;
3065                 next = qp->r_head_ack_queue + 1;
3066                 /* s_ack_queue is size rvt_size_atomic()+1 so use > not >= */
3067                 if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
3068                         next = 0;
3069                 spin_lock_irqsave(&qp->s_lock, flags);
3070                 if (unlikely(next == qp->s_acked_ack_queue)) {
3071                         if (!qp->s_ack_queue[next].sent)
3072                                 goto nack_inv_unlck;
3073                         update_ack_queue(qp, next);
3074                 }
3075                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
3076                 release_rdma_sge_mr(e);
3077                 reth = &ohdr->u.rc.reth;
3078                 len = be32_to_cpu(reth->length);
3079                 if (len) {
3080                         u32 rkey = be32_to_cpu(reth->rkey);
3081                         u64 vaddr = get_ib_reth_vaddr(reth);
3082                         int ok;
3083
3084                         /* Check rkey & NAK */
3085                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr,
3086                                          rkey, IB_ACCESS_REMOTE_READ);
3087                         if (unlikely(!ok))
3088                                 goto nack_acc_unlck;
3089                         /*
3090                          * Update the next expected PSN.  We add 1 later
3091                          * below, so only add the remainder here.
3092                          */
3093                         qp->r_psn += rvt_div_mtu(qp, len - 1);
3094                 } else {
3095                         e->rdma_sge.mr = NULL;
3096                         e->rdma_sge.vaddr = NULL;
3097                         e->rdma_sge.length = 0;
3098                         e->rdma_sge.sge_length = 0;
3099                 }
3100                 e->opcode = opcode;
3101                 e->sent = 0;
3102                 e->psn = psn;
3103                 e->lpsn = qp->r_psn;
3104                 /*
3105                  * We need to increment the MSN here instead of when we
3106                  * finish sending the result since a duplicate request would
3107                  * increment it more than once.
3108                  */
3109                 qp->r_msn++;
3110                 qp->r_psn++;
3111                 qp->r_state = opcode;
3112                 qp->r_nak_state = 0;
3113                 qp->r_head_ack_queue = next;
3114                 qpriv->r_tid_alloc = qp->r_head_ack_queue;
3115
3116                 /* Schedule the send engine. */
3117                 qp->s_flags |= RVT_S_RESP_PENDING;
3118                 if (fecn)
3119                         qp->s_flags |= RVT_S_ECN;
3120                 hfi1_schedule_send(qp);
3121
3122                 spin_unlock_irqrestore(&qp->s_lock, flags);
3123                 return;
3124         }
3125
3126         case OP(COMPARE_SWAP):
3127         case OP(FETCH_ADD): {
3128                 struct ib_atomic_eth *ateth = &ohdr->u.atomic_eth;
3129                 u64 vaddr = get_ib_ateth_vaddr(ateth);
3130                 bool opfn = opcode == OP(COMPARE_SWAP) &&
3131                         vaddr == HFI1_VERBS_E_ATOMIC_VADDR;
3132                 struct rvt_ack_entry *e;
3133                 atomic64_t *maddr;
3134                 u64 sdata;
3135                 u32 rkey;
3136                 u8 next;
3137
3138                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC) &&
3139                              !opfn))
3140                         goto nack_inv;
3141                 next = qp->r_head_ack_queue + 1;
3142                 if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
3143                         next = 0;
3144                 spin_lock_irqsave(&qp->s_lock, flags);
3145                 if (unlikely(next == qp->s_acked_ack_queue)) {
3146                         if (!qp->s_ack_queue[next].sent)
3147                                 goto nack_inv_unlck;
3148                         update_ack_queue(qp, next);
3149                 }
3150                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
3151                 release_rdma_sge_mr(e);
3152                 /* Process OPFN special virtual address */
3153                 if (opfn) {
3154                         opfn_conn_response(qp, e, ateth);
3155                         goto ack;
3156                 }
3157                 if (unlikely(vaddr & (sizeof(u64) - 1)))
3158                         goto nack_inv_unlck;
3159                 rkey = be32_to_cpu(ateth->rkey);
3160                 /* Check rkey & NAK */
3161                 if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
3162                                           vaddr, rkey,
3163                                           IB_ACCESS_REMOTE_ATOMIC)))
3164                         goto nack_acc_unlck;
3165                 /* Perform atomic OP and save result. */
3166                 maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
3167                 sdata = get_ib_ateth_swap(ateth);
3168                 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
3169                         (u64)atomic64_add_return(sdata, maddr) - sdata :
3170                         (u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
3171                                       get_ib_ateth_compare(ateth),
3172                                       sdata);
3173                 rvt_put_mr(qp->r_sge.sge.mr);
3174                 qp->r_sge.num_sge = 0;
3175 ack:
3176                 e->opcode = opcode;
3177                 e->sent = 0;
3178                 e->psn = psn;
3179                 e->lpsn = psn;
3180                 qp->r_msn++;
3181                 qp->r_psn++;
3182                 qp->r_state = opcode;
3183                 qp->r_nak_state = 0;
3184                 qp->r_head_ack_queue = next;
3185                 qpriv->r_tid_alloc = qp->r_head_ack_queue;
3186
3187                 /* Schedule the send engine. */
3188                 qp->s_flags |= RVT_S_RESP_PENDING;
3189                 if (fecn)
3190                         qp->s_flags |= RVT_S_ECN;
3191                 hfi1_schedule_send(qp);
3192
3193                 spin_unlock_irqrestore(&qp->s_lock, flags);
3194                 return;
3195         }
3196
3197         default:
3198                 /* NAK unknown opcodes. */
3199                 goto nack_inv;
3200         }
3201         qp->r_psn++;
3202         qp->r_state = opcode;
3203         qp->r_ack_psn = psn;
3204         qp->r_nak_state = 0;
3205         /* Send an ACK if requested or required. */
3206         if (psn & IB_BTH_REQ_ACK || fecn) {
3207                 if (packet->numpkt == 0 || fecn ||
3208                     qp->r_adefered >= HFI1_PSN_CREDIT) {
3209                         rc_cancel_ack(qp);
3210                         goto send_ack;
3211                 }
3212                 qp->r_adefered++;
3213                 rc_defered_ack(rcd, qp);
3214         }
3215         return;
3216
3217 rnr_nak:
3218         qp->r_nak_state = qp->r_min_rnr_timer | IB_RNR_NAK;
3219         qp->r_ack_psn = qp->r_psn;
3220         /* Queue RNR NAK for later */
3221         rc_defered_ack(rcd, qp);
3222         return;
3223
3224 nack_op_err:
3225         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
3226         qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
3227         qp->r_ack_psn = qp->r_psn;
3228         /* Queue NAK for later */
3229         rc_defered_ack(rcd, qp);
3230         return;
3231
3232 nack_inv_unlck:
3233         spin_unlock_irqrestore(&qp->s_lock, flags);
3234 nack_inv:
3235         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
3236         qp->r_nak_state = IB_NAK_INVALID_REQUEST;
3237         qp->r_ack_psn = qp->r_psn;
3238         /* Queue NAK for later */
3239         rc_defered_ack(rcd, qp);
3240         return;
3241
3242 nack_acc_unlck:
3243         spin_unlock_irqrestore(&qp->s_lock, flags);
3244 nack_acc:
3245         rvt_rc_error(qp, IB_WC_LOC_PROT_ERR);
3246         qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
3247         qp->r_ack_psn = qp->r_psn;
3248 send_ack:
3249         hfi1_send_rc_ack(packet, fecn);
3250 }
3251
3252 void hfi1_rc_hdrerr(
3253         struct hfi1_ctxtdata *rcd,
3254         struct hfi1_packet *packet,
3255         struct rvt_qp *qp)
3256 {
3257         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
3258         int diff;
3259         u32 opcode;
3260         u32 psn;
3261
3262         if (hfi1_ruc_check_hdr(ibp, packet))
3263                 return;
3264
3265         psn = ib_bth_get_psn(packet->ohdr);
3266         opcode = ib_bth_get_opcode(packet->ohdr);
3267
3268         /* Only deal with RDMA Writes for now */
3269         if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {
3270                 diff = delta_psn(psn, qp->r_psn);
3271                 if (!qp->r_nak_state && diff >= 0) {
3272                         ibp->rvp.n_rc_seqnak++;
3273                         qp->r_nak_state = IB_NAK_PSN_ERROR;
3274                         /* Use the expected PSN. */
3275                         qp->r_ack_psn = qp->r_psn;
3276                         /*
3277                          * Wait to send the sequence
3278                          * NAK until all packets
3279                          * in the receive queue have
3280                          * been processed.
3281                          * Otherwise, we end up
3282                          * propagating congestion.
3283                          */
3284                         rc_defered_ack(rcd, qp);
3285                 } /* Out of sequence NAK */
3286         } /* QP Request NAKs */
3287 }