drivers/infiniband/hw/hfi1/rc.c

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
   2 /*
   3  * Copyright(c) 2015 - 2018 Intel Corporation.
   4  */
   5
   6 #include <linux/io.h>
   7 #include <rdma/rdma_vt.h>
   8 #include <rdma/rdmavt_qp.h>
   9
  10 #include "hfi.h"
  11 #include "qp.h"
  12 #include "rc.h"
  13 #include "verbs_txreq.h"
  14 #include "trace.h"
  15
  16 struct rvt_ack_entry *find_prev_entry(struct rvt_qp *qp, u32 psn, u8 *prev,
  17                                       u8 *prev_ack, bool *scheduled)
  18         __must_hold(&qp->s_lock)
  19 {
  20         struct rvt_ack_entry *e = NULL;
  21         u8 i, p;
  22         bool s = true;
  23
  24         for (i = qp->r_head_ack_queue; ; i = p) {
  25                 if (i == qp->s_tail_ack_queue)
  26                         s = false;
  27                 if (i)
  28                         p = i - 1;
  29                 else
  30                         p = rvt_size_atomic(ib_to_rvt(qp->ibqp.device));
  31                 if (p == qp->r_head_ack_queue) {
  32                         e = NULL;
  33                         break;
  34                 }
  35                 e = &qp->s_ack_queue[p];
  36                 if (!e->opcode) {
  37                         e = NULL;
  38                         break;
  39                 }
  40                 if (cmp_psn(psn, e->psn) >= 0) {
  41                         if (p == qp->s_tail_ack_queue &&
  42                             cmp_psn(psn, e->lpsn) <= 0)
  43                                 s = false;
  44                         break;
  45                 }
  46         }
  47         if (prev)
  48                 *prev = p;
  49         if (prev_ack)
  50                 *prev_ack = i;
  51         if (scheduled)
  52                 *scheduled = s;
  53         return e;
  54 }
  55
  56 /**
  57  * make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
  58  * @dev: the device for this QP
  59  * @qp: a pointer to the QP
  60  * @ohdr: a pointer to the IB header being constructed
  61  * @ps: the xmit packet state
  62  *
  63  * Return 1 if constructed; otherwise, return 0.
  64  * Note that we are in the responder's side of the QP context.
  65  * Note the QP s_lock must be held.
  66  */
  67 static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp,
  68                        struct ib_other_headers *ohdr,
  69                        struct hfi1_pkt_state *ps)
  70 {
  71         struct rvt_ack_entry *e;
  72         u32 hwords, hdrlen;
  73         u32 len = 0;
  74         u32 bth0 = 0, bth2 = 0;
  75         u32 bth1 = qp->remote_qpn | (HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT);
  76         int middle = 0;
  77         u32 pmtu = qp->pmtu;
  78         struct hfi1_qp_priv *qpriv = qp->priv;
  79         bool last_pkt;
  80         u32 delta;
  81         u8 next = qp->s_tail_ack_queue;
  82         struct tid_rdma_request *req;
  83
  84         trace_hfi1_rsp_make_rc_ack(qp, 0);
  85         lockdep_assert_held(&qp->s_lock);
  86         /* Don't send an ACK if we aren't supposed to. */
  87         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
  88                 goto bail;
  89
  90         if (qpriv->hdr_type == HFI1_PKT_TYPE_9B)
  91                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
  92                 hwords = 5;
  93         else
  94                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
  95                 hwords = 7;
  96
  97         switch (qp->s_ack_state) {
  98         case OP(RDMA_READ_RESPONSE_LAST):
  99         case OP(RDMA_READ_RESPONSE_ONLY):
 100                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 101                 release_rdma_sge_mr(e);
 102                 fallthrough;
 103         case OP(ATOMIC_ACKNOWLEDGE):
 104                 /*
 105                  * We can increment the tail pointer now that the last
 106                  * response has been sent instead of only being
 107                  * constructed.
 108                  */
 109                 if (++next > rvt_size_atomic(&dev->rdi))
 110                         next = 0;
 111                 /*
 112                  * Only advance the s_acked_ack_queue pointer if there
 113                  * have been no TID RDMA requests.
 114                  */
 115                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 116                 if (e->opcode != TID_OP(WRITE_REQ) &&
 117                     qp->s_acked_ack_queue == qp->s_tail_ack_queue)
 118                         qp->s_acked_ack_queue = next;
 119                 qp->s_tail_ack_queue = next;
 120                 trace_hfi1_rsp_make_rc_ack(qp, e->psn);
 121                 fallthrough;
 122         case OP(SEND_ONLY):
 123         case OP(ACKNOWLEDGE):
 124                 /* Check for no next entry in the queue. */
 125                 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
 126                         if (qp->s_flags & RVT_S_ACK_PENDING)
 127                                 goto normal;
 128                         goto bail;
 129                 }
 130
 131                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 132                 /* Check for tid write fence */
 133                 if ((qpriv->s_flags & HFI1_R_TID_WAIT_INTERLCK) ||
 134                     hfi1_tid_rdma_ack_interlock(qp, e)) {
 135                         iowait_set_flag(&qpriv->s_iowait, IOWAIT_PENDING_IB);
 136                         goto bail;
 137                 }
 138                 if (e->opcode == OP(RDMA_READ_REQUEST)) {
 139                         /*
 140                          * If a RDMA read response is being resent and
 141                          * we haven't seen the duplicate request yet,
 142                          * then stop sending the remaining responses the
 143                          * responder has seen until the requester re-sends it.
 144                          */
 145                         len = e->rdma_sge.sge_length;
 146                         if (len && !e->rdma_sge.mr) {
 147                                 if (qp->s_acked_ack_queue ==
 148                                     qp->s_tail_ack_queue)
 149                                         qp->s_acked_ack_queue =
 150                                                 qp->r_head_ack_queue;
 151                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
 152                                 goto bail;
 153                         }
 154                         /* Copy SGE state in case we need to resend */
 155                         ps->s_txreq->mr = e->rdma_sge.mr;
 156                         if (ps->s_txreq->mr)
 157                                 rvt_get_mr(ps->s_txreq->mr);
 158                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
 159                         qp->s_ack_rdma_sge.num_sge = 1;
 160                         ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 161                         if (len > pmtu) {
 162                                 len = pmtu;
 163                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
 164                         } else {
 165                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
 166                                 e->sent = 1;
 167                         }
 168                         ohdr->u.aeth = rvt_compute_aeth(qp);
 169                         hwords++;
 170                         qp->s_ack_rdma_psn = e->psn;
 171                         bth2 = mask_psn(qp->s_ack_rdma_psn++);
 172                 } else if (e->opcode == TID_OP(WRITE_REQ)) {
 173                         /*
 174                          * If a TID RDMA WRITE RESP is being resent, we have to
 175                          * wait for the actual request. All requests that are to
 176                          * be resent will have their state set to
 177                          * TID_REQUEST_RESEND. When the new request arrives, the
 178                          * state will be changed to TID_REQUEST_RESEND_ACTIVE.
 179                          */
 180                         req = ack_to_tid_req(e);
 181                         if (req->state == TID_REQUEST_RESEND ||
 182                             req->state == TID_REQUEST_INIT_RESEND)
 183                                 goto bail;
 184                         qp->s_ack_state = TID_OP(WRITE_RESP);
 185                         qp->s_ack_rdma_psn = mask_psn(e->psn + req->cur_seg);
 186                         goto write_resp;
 187                 } else if (e->opcode == TID_OP(READ_REQ)) {
 188                         /*
 189                          * If a TID RDMA read response is being resent and
 190                          * we haven't seen the duplicate request yet,
 191                          * then stop sending the remaining responses the
 192                          * responder has seen until the requester re-sends it.
 193                          */
 194                         len = e->rdma_sge.sge_length;
 195                         if (len && !e->rdma_sge.mr) {
 196                                 if (qp->s_acked_ack_queue ==
 197                                     qp->s_tail_ack_queue)
 198                                         qp->s_acked_ack_queue =
 199                                                 qp->r_head_ack_queue;
 200                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
 201                                 goto bail;
 202                         }
 203                         /* Copy SGE state in case we need to resend */
 204                         ps->s_txreq->mr = e->rdma_sge.mr;
 205                         if (ps->s_txreq->mr)
 206                                 rvt_get_mr(ps->s_txreq->mr);
 207                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
 208                         qp->s_ack_rdma_sge.num_sge = 1;
 209                         qp->s_ack_state = TID_OP(READ_RESP);
 210                         goto read_resp;
 211                 } else {
 212                         /* COMPARE_SWAP or FETCH_ADD */
 213                         ps->s_txreq->ss = NULL;
 214                         len = 0;
 215                         qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
 216                         ohdr->u.at.aeth = rvt_compute_aeth(qp);
 217                         ib_u64_put(e->atomic_data, &ohdr->u.at.atomic_ack_eth);
 218                         hwords += sizeof(ohdr->u.at) / sizeof(u32);
 219                         bth2 = mask_psn(e->psn);
 220                         e->sent = 1;
 221                 }
 222                 trace_hfi1_tid_write_rsp_make_rc_ack(qp);
 223                 bth0 = qp->s_ack_state << 24;
 224                 break;
 225
 226         case OP(RDMA_READ_RESPONSE_FIRST):
 227                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
 228                 fallthrough;
 229         case OP(RDMA_READ_RESPONSE_MIDDLE):
 230                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 231                 ps->s_txreq->mr = qp->s_ack_rdma_sge.sge.mr;
 232                 if (ps->s_txreq->mr)
 233                         rvt_get_mr(ps->s_txreq->mr);
 234                 len = qp->s_ack_rdma_sge.sge.sge_length;
 235                 if (len > pmtu) {
 236                         len = pmtu;
 237                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 238                 } else {
 239                         ohdr->u.aeth = rvt_compute_aeth(qp);
 240                         hwords++;
 241                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
 242                         e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 243                         e->sent = 1;
 244                 }
 245                 bth0 = qp->s_ack_state << 24;
 246                 bth2 = mask_psn(qp->s_ack_rdma_psn++);
 247                 break;
 248
 249         case TID_OP(WRITE_RESP):
 250 write_resp:
 251                 /*
 252                  * 1. Check if RVT_S_ACK_PENDING is set. If yes,
 253                  *    goto normal.
 254                  * 2. Attempt to allocate TID resources.
 255                  * 3. Remove RVT_S_RESP_PENDING flags from s_flags
 256                  * 4. If resources not available:
 257                  *    4.1 Set RVT_S_WAIT_TID_SPACE
 258                  *    4.2 Queue QP on RCD TID queue
 259                  *    4.3 Put QP on iowait list.
 260                  *    4.4 Build IB RNR NAK with appropriate timeout value
 261                  *    4.5 Return indication progress made.
 262                  * 5. If resources are available:
 263                  *    5.1 Program HW flow CSRs
 264                  *    5.2 Build TID RDMA WRITE RESP packet
 265                  *    5.3 If more resources needed, do 2.1 - 2.3.
 266                  *    5.4 Wake up next QP on RCD TID queue.
 267                  *    5.5 Return indication progress made.
 268                  */
 269
 270                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 271                 req = ack_to_tid_req(e);
 272
 273                 /*
 274                  * Send scheduled RNR NAK's. RNR NAK's need to be sent at
 275                  * segment boundaries, not at request boundaries. Don't change
 276                  * s_ack_state because we are still in the middle of a request
 277                  */
 278                 if (qpriv->rnr_nak_state == TID_RNR_NAK_SEND &&
 279                     qp->s_tail_ack_queue == qpriv->r_tid_alloc &&
 280                     req->cur_seg == req->alloc_seg) {
 281                         qpriv->rnr_nak_state = TID_RNR_NAK_SENT;
 282                         goto normal_no_state;
 283                 }
 284
 285                 bth2 = mask_psn(qp->s_ack_rdma_psn);
 286                 hdrlen = hfi1_build_tid_rdma_write_resp(qp, e, ohdr, &bth1,
 287                                                         bth2, &len,
 288                                                         &ps->s_txreq->ss);
 289                 if (!hdrlen)
 290                         return 0;
 291
 292                 hwords += hdrlen;
 293                 bth0 = qp->s_ack_state << 24;
 294                 qp->s_ack_rdma_psn++;
 295                 trace_hfi1_tid_req_make_rc_ack_write(qp, 0, e->opcode, e->psn,
 296                                                      e->lpsn, req);
 297                 if (req->cur_seg != req->total_segs)
 298                         break;
 299
 300                 e->sent = 1;
 301                 /* Do not free e->rdma_sge until all data are received */
 302                 qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
 303                 break;
 304
 305         case TID_OP(READ_RESP):
 306 read_resp:
 307                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
 308                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
 309                 delta = hfi1_build_tid_rdma_read_resp(qp, e, ohdr, &bth0,
 310                                                       &bth1, &bth2, &len,
 311                                                       &last_pkt);
 312                 if (delta == 0)
 313                         goto error_qp;
 314                 hwords += delta;
 315                 if (last_pkt) {
 316                         e->sent = 1;
 317                         /*
 318                          * Increment qp->s_tail_ack_queue through s_ack_state
 319                          * transition.
 320                          */
 321                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
 322                 }
 323                 break;
 324         case TID_OP(READ_REQ):
 325                 goto bail;
 326
 327         default:
 328 normal:
 329                 /*
 330                  * Send a regular ACK.
 331                  * Set the s_ack_state so we wait until after sending
 332                  * the ACK before setting s_ack_state to ACKNOWLEDGE
 333                  * (see above).
 334                  */
 335                 qp->s_ack_state = OP(SEND_ONLY);
 336 normal_no_state:
 337                 if (qp->s_nak_state)
 338                         ohdr->u.aeth =
 339                                 cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
 340                                             (qp->s_nak_state <<
 341                                              IB_AETH_CREDIT_SHIFT));
 342                 else
 343                         ohdr->u.aeth = rvt_compute_aeth(qp);
 344                 hwords++;
 345                 len = 0;
 346                 bth0 = OP(ACKNOWLEDGE) << 24;
 347                 bth2 = mask_psn(qp->s_ack_psn);
 348                 qp->s_flags &= ~RVT_S_ACK_PENDING;
 349                 ps->s_txreq->txreq.flags |= SDMA_TXREQ_F_VIP;
 350                 ps->s_txreq->ss = NULL;
 351         }
 352         qp->s_rdma_ack_cnt++;
 353         ps->s_txreq->sde = qpriv->s_sde;
 354         ps->s_txreq->s_cur_size = len;
 355         ps->s_txreq->hdr_dwords = hwords;
 356         hfi1_make_ruc_header(qp, ohdr, bth0, bth1, bth2, middle, ps);
 357         return 1;
 358 error_qp:
 359         spin_unlock_irqrestore(&qp->s_lock, ps->flags);
 360         spin_lock_irqsave(&qp->r_lock, ps->flags);
 361         spin_lock(&qp->s_lock);
 362         rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
 363         spin_unlock(&qp->s_lock);
 364         spin_unlock_irqrestore(&qp->r_lock, ps->flags);
 365         spin_lock_irqsave(&qp->s_lock, ps->flags);
 366 bail:
 367         qp->s_ack_state = OP(ACKNOWLEDGE);
 368         /*
 369          * Ensure s_rdma_ack_cnt changes are committed prior to resetting
 370          * RVT_S_RESP_PENDING
 371          */
 372         smp_wmb();
 373         qp->s_flags &= ~(RVT_S_RESP_PENDING
 374                                 | RVT_S_ACK_PENDING
 375                                 | HFI1_S_AHG_VALID);
 376         return 0;
 377 }
 378
 379 /**
 380  * hfi1_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
 381  * @qp: a pointer to the QP
 382  * @ps: the current packet state
 383  *
 384  * Assumes s_lock is held.
 385  *
 386  * Return 1 if constructed; otherwise, return 0.
 387  */
 388 int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
 389 {
 390         struct hfi1_qp_priv *priv = qp->priv;
 391         struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
 392         struct ib_other_headers *ohdr;
 393         struct rvt_sge_state *ss = NULL;
 394         struct rvt_swqe *wqe;
 395         struct hfi1_swqe_priv *wpriv;
 396         struct tid_rdma_request *req = NULL;
 397         /* header size in 32-bit words LRH+BTH = (8+12)/4. */
 398         u32 hwords = 5;
 399         u32 len = 0;
 400         u32 bth0 = 0, bth2 = 0;
 401         u32 bth1 = qp->remote_qpn | (HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT);
 402         u32 pmtu = qp->pmtu;
 403         char newreq;
 404         int middle = 0;
 405         int delta;
 406         struct tid_rdma_flow *flow = NULL;
 407         struct tid_rdma_params *remote;
 408
 409         trace_hfi1_sender_make_rc_req(qp);
 410         lockdep_assert_held(&qp->s_lock);
 411         ps->s_txreq = get_txreq(ps->dev, qp);
 412         if (!ps->s_txreq)
 413                 goto bail_no_tx;
 414
 415         if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
 416                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
 417                 hwords = 5;
 418                 if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
 419                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
 420                 else
 421                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
 422         } else {
 423                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
 424                 hwords = 7;
 425                 if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
 426                     (hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))))
 427                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
 428                 else
 429                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
 430         }
 431
 432         /* Sending responses has higher priority over sending requests. */
 433         if ((qp->s_flags & RVT_S_RESP_PENDING) &&
 434             make_rc_ack(dev, qp, ohdr, ps))
 435                 return 1;
 436
 437         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
 438                 if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
 439                         goto bail;
 440                 /* We are in the error state, flush the work request. */
 441                 if (qp->s_last == READ_ONCE(qp->s_head))
 442                         goto bail;
 443                 /* If DMAs are in progress, we can't flush immediately. */
 444                 if (iowait_sdma_pending(&priv->s_iowait)) {
 445                         qp->s_flags |= RVT_S_WAIT_DMA;
 446                         goto bail;
 447                 }
 448                 clear_ahg(qp);
 449                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
 450                 hfi1_trdma_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
 451                                          IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
 452                 /* will get called again */
 453                 goto done_free_tx;
 454         }
 455
 456         if (qp->s_flags & (RVT_S_WAIT_RNR | RVT_S_WAIT_ACK | HFI1_S_WAIT_HALT))
 457                 goto bail;
 458
 459         if (cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) {
 460                 if (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) {
 461                         qp->s_flags |= RVT_S_WAIT_PSN;
 462                         goto bail;
 463                 }
 464                 qp->s_sending_psn = qp->s_psn;
 465                 qp->s_sending_hpsn = qp->s_psn - 1;
 466         }
 467
 468         /* Send a request. */
 469         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
 470 check_s_state:
 471         switch (qp->s_state) {
 472         default:
 473                 if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK))
 474                         goto bail;
 475                 /*
 476                  * Resend an old request or start a new one.
 477                  *
 478                  * We keep track of the current SWQE so that
 479                  * we don't reset the "furthest progress" state
 480                  * if we need to back up.
 481                  */
 482                 newreq = 0;
 483                 if (qp->s_cur == qp->s_tail) {
 484                         /* Check if send work queue is empty. */
 485                         if (qp->s_tail == READ_ONCE(qp->s_head)) {
 486                                 clear_ahg(qp);
 487                                 goto bail;
 488                         }
 489                         /*
 490                          * If a fence is requested, wait for previous
 491                          * RDMA read and atomic operations to finish.
 492                          * However, there is no need to guard against
 493                          * TID RDMA READ after TID RDMA READ.
 494                          */
 495                         if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
 496                             qp->s_num_rd_atomic &&
 497                             (wqe->wr.opcode != IB_WR_TID_RDMA_READ ||
 498                              priv->pending_tid_r_segs < qp->s_num_rd_atomic)) {
 499                                 qp->s_flags |= RVT_S_WAIT_FENCE;
 500                                 goto bail;
 501                         }
 502                         /*
 503                          * Local operations are processed immediately
 504                          * after all prior requests have completed
 505                          */
 506                         if (wqe->wr.opcode == IB_WR_REG_MR ||
 507                             wqe->wr.opcode == IB_WR_LOCAL_INV) {
 508                                 int local_ops = 0;
 509                                 int err = 0;
 510
 511                                 if (qp->s_last != qp->s_cur)
 512                                         goto bail;
 513                                 if (++qp->s_cur == qp->s_size)
 514                                         qp->s_cur = 0;
 515                                 if (++qp->s_tail == qp->s_size)
 516                                         qp->s_tail = 0;
 517                                 if (!(wqe->wr.send_flags &
 518                                       RVT_SEND_COMPLETION_ONLY)) {
 519                                         err = rvt_invalidate_rkey(
 520                                                 qp,
 521                                                 wqe->wr.ex.invalidate_rkey);
 522                                         local_ops = 1;
 523                                 }
 524                                 rvt_send_complete(qp, wqe,
 525                                                   err ? IB_WC_LOC_PROT_ERR
 526                                                       : IB_WC_SUCCESS);
 527                                 if (local_ops)
 528                                         atomic_dec(&qp->local_ops_pending);
 529                                 goto done_free_tx;
 530                         }
 531
 532                         newreq = 1;
 533                         qp->s_psn = wqe->psn;
 534                 }
 535                 /*
 536                  * Note that we have to be careful not to modify the
 537                  * original work request since we may need to resend
 538                  * it.
 539                  */
 540                 len = wqe->length;
 541                 ss = &qp->s_sge;
 542                 bth2 = mask_psn(qp->s_psn);
 543
 544                 /*
 545                  * Interlock between various IB requests and TID RDMA
 546                  * if necessary.
 547                  */
 548                 if ((priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) ||
 549                     hfi1_tid_rdma_wqe_interlock(qp, wqe))
 550                         goto bail;
 551
 552                 switch (wqe->wr.opcode) {
 553                 case IB_WR_SEND:
 554                 case IB_WR_SEND_WITH_IMM:
 555                 case IB_WR_SEND_WITH_INV:
 556                         /* If no credit, return. */
 557                         if (!rvt_rc_credit_avail(qp, wqe))
 558                                 goto bail;
 559                         if (len > pmtu) {
 560                                 qp->s_state = OP(SEND_FIRST);
 561                                 len = pmtu;
 562                                 break;
 563                         }
 564                         if (wqe->wr.opcode == IB_WR_SEND) {
 565                                 qp->s_state = OP(SEND_ONLY);
 566                         } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 567                                 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
 568                                 /* Immediate data comes after the BTH */
 569                                 ohdr->u.imm_data = wqe->wr.ex.imm_data;
 570                                 hwords += 1;
 571                         } else {
 572                                 qp->s_state = OP(SEND_ONLY_WITH_INVALIDATE);
 573                                 /* Invalidate rkey comes after the BTH */
 574                                 ohdr->u.ieth = cpu_to_be32(
 575                                                 wqe->wr.ex.invalidate_rkey);
 576                                 hwords += 1;
 577                         }
 578                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 579                                 bth0 |= IB_BTH_SOLICITED;
 580                         bth2 |= IB_BTH_REQ_ACK;
 581                         if (++qp->s_cur == qp->s_size)
 582                                 qp->s_cur = 0;
 583                         break;
 584
 585                 case IB_WR_RDMA_WRITE:
 586                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 587                                 qp->s_lsn++;
 588                         goto no_flow_control;
 589                 case IB_WR_RDMA_WRITE_WITH_IMM:
 590                         /* If no credit, return. */
 591                         if (!rvt_rc_credit_avail(qp, wqe))
 592                                 goto bail;
 593 no_flow_control:
 594                         put_ib_reth_vaddr(
 595                                 wqe->rdma_wr.remote_addr,
 596                                 &ohdr->u.rc.reth);
 597                         ohdr->u.rc.reth.rkey =
 598                                 cpu_to_be32(wqe->rdma_wr.rkey);
 599                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 600                         hwords += sizeof(struct ib_reth) / sizeof(u32);
 601                         if (len > pmtu) {
 602                                 qp->s_state = OP(RDMA_WRITE_FIRST);
 603                                 len = pmtu;
 604                                 break;
 605                         }
 606                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 607                                 qp->s_state = OP(RDMA_WRITE_ONLY);
 608                         } else {
 609                                 qp->s_state =
 610                                         OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
 611                                 /* Immediate data comes after RETH */
 612                                 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
 613                                 hwords += 1;
 614                                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 615                                         bth0 |= IB_BTH_SOLICITED;
 616                         }
 617                         bth2 |= IB_BTH_REQ_ACK;
 618                         if (++qp->s_cur == qp->s_size)
 619                                 qp->s_cur = 0;
 620                         break;
 621
 622                 case IB_WR_TID_RDMA_WRITE:
 623                         if (newreq) {
 624                                 /*
 625                                  * Limit the number of TID RDMA WRITE requests.
 626                                  */
 627                                 if (atomic_read(&priv->n_tid_requests) >=
 628                                     HFI1_TID_RDMA_WRITE_CNT)
 629                                         goto bail;
 630
 631                                 if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 632                                         qp->s_lsn++;
 633                         }
 634
 635                         hwords += hfi1_build_tid_rdma_write_req(qp, wqe, ohdr,
 636                                                                 &bth1, &bth2,
 637                                                                 &len);
 638                         ss = NULL;
 639                         if (priv->s_tid_cur == HFI1_QP_WQE_INVALID) {
 640                                 priv->s_tid_cur = qp->s_cur;
 641                                 if (priv->s_tid_tail == HFI1_QP_WQE_INVALID) {
 642                                         priv->s_tid_tail = qp->s_cur;
 643                                         priv->s_state = TID_OP(WRITE_RESP);
 644                                 }
 645                         } else if (priv->s_tid_cur == priv->s_tid_head) {
 646                                 struct rvt_swqe *__w;
 647                                 struct tid_rdma_request *__r;
 648
 649                                 __w = rvt_get_swqe_ptr(qp, priv->s_tid_cur);
 650                                 __r = wqe_to_tid_req(__w);
 651
 652                                 /*
 653                                  * The s_tid_cur pointer is advanced to s_cur if
 654                                  * any of the following conditions about the WQE
 655                                  * to which s_ti_cur currently points to are
 656                                  * satisfied:
 657                                  *   1. The request is not a TID RDMA WRITE
 658                                  *      request,
 659                                  *   2. The request is in the INACTIVE or
 660                                  *      COMPLETE states (TID RDMA READ requests
 661                                  *      stay at INACTIVE and TID RDMA WRITE
 662                                  *      transition to COMPLETE when done),
 663                                  *   3. The request is in the ACTIVE or SYNC
 664                                  *      state and the number of completed
 665                                  *      segments is equal to the total segment
 666                                  *      count.
 667                                  *      (If ACTIVE, the request is waiting for
 668                                  *       ACKs. If SYNC, the request has not
 669                                  *       received any responses because it's
 670                                  *       waiting on a sync point.)
 671                                  */
 672                                 if (__w->wr.opcode != IB_WR_TID_RDMA_WRITE ||
 673                                     __r->state == TID_REQUEST_INACTIVE ||
 674                                     __r->state == TID_REQUEST_COMPLETE ||
 675                                     ((__r->state == TID_REQUEST_ACTIVE ||
 676                                       __r->state == TID_REQUEST_SYNC) &&
 677                                      __r->comp_seg == __r->total_segs)) {
 678                                         if (priv->s_tid_tail ==
 679                                             priv->s_tid_cur &&
 680                                             priv->s_state ==
 681                                             TID_OP(WRITE_DATA_LAST)) {
 682                                                 priv->s_tid_tail = qp->s_cur;
 683                                                 priv->s_state =
 684                                                         TID_OP(WRITE_RESP);
 685                                         }
 686                                         priv->s_tid_cur = qp->s_cur;
 687                                 }
 688                                 /*
 689                                  * A corner case: when the last TID RDMA WRITE
 690                                  * request was completed, s_tid_head,
 691                                  * s_tid_cur, and s_tid_tail all point to the
 692                                  * same location. Other requests are posted and
 693                                  * s_cur wraps around to the same location,
 694                                  * where a new TID RDMA WRITE is posted. In
 695                                  * this case, none of the indices need to be
 696                                  * updated. However, the priv->s_state should.
 697                                  */
 698                                 if (priv->s_tid_tail == qp->s_cur &&
 699                                     priv->s_state == TID_OP(WRITE_DATA_LAST))
 700                                         priv->s_state = TID_OP(WRITE_RESP);
 701                         }
 702                         req = wqe_to_tid_req(wqe);
 703                         if (newreq) {
 704                                 priv->s_tid_head = qp->s_cur;
 705                                 priv->pending_tid_w_resp += req->total_segs;
 706                                 atomic_inc(&priv->n_tid_requests);
 707                                 atomic_dec(&priv->n_requests);
 708                         } else {
 709                                 req->state = TID_REQUEST_RESEND;
 710                                 req->comp_seg = delta_psn(bth2, wqe->psn);
 711                                 /*
 712                                  * Pull back any segments since we are going
 713                                  * to re-receive them.
 714                                  */
 715                                 req->setup_head = req->clear_tail;
 716                                 priv->pending_tid_w_resp +=
 717                                         delta_psn(wqe->lpsn, bth2) + 1;
 718                         }
 719
 720                         trace_hfi1_tid_write_sender_make_req(qp, newreq);
 721                         trace_hfi1_tid_req_make_req_write(qp, newreq,
 722                                                           wqe->wr.opcode,
 723                                                           wqe->psn, wqe->lpsn,
 724                                                           req);
 725                         if (++qp->s_cur == qp->s_size)
 726                                 qp->s_cur = 0;
 727                         break;
 728
 729                 case IB_WR_RDMA_READ:
 730                         /*
 731                          * Don't allow more operations to be started
 732                          * than the QP limits allow.
 733                          */
 734                         if (qp->s_num_rd_atomic >=
 735                             qp->s_max_rd_atomic) {
 736                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
 737                                 goto bail;
 738                         }
 739                         qp->s_num_rd_atomic++;
 740                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 741                                 qp->s_lsn++;
 742                         put_ib_reth_vaddr(
 743                                 wqe->rdma_wr.remote_addr,
 744                                 &ohdr->u.rc.reth);
 745                         ohdr->u.rc.reth.rkey =
 746                                 cpu_to_be32(wqe->rdma_wr.rkey);
 747                         ohdr->u.rc.reth.length = cpu_to_be32(len);
 748                         qp->s_state = OP(RDMA_READ_REQUEST);
 749                         hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
 750                         ss = NULL;
 751                         len = 0;
 752                         bth2 |= IB_BTH_REQ_ACK;
 753                         if (++qp->s_cur == qp->s_size)
 754                                 qp->s_cur = 0;
 755                         break;
 756
 757                 case IB_WR_TID_RDMA_READ:
 758                         trace_hfi1_tid_read_sender_make_req(qp, newreq);
 759                         wpriv = wqe->priv;
 760                         req = wqe_to_tid_req(wqe);
 761                         trace_hfi1_tid_req_make_req_read(qp, newreq,
 762                                                          wqe->wr.opcode,
 763                                                          wqe->psn, wqe->lpsn,
 764                                                          req);
 765                         delta = cmp_psn(qp->s_psn, wqe->psn);
 766
 767                         /*
 768                          * Don't allow more operations to be started
 769                          * than the QP limits allow. We could get here under
 770                          * three conditions; (1) It's a new request; (2) We are
 771                          * sending the second or later segment of a request,
 772                          * but the qp->s_state is set to OP(RDMA_READ_REQUEST)
 773                          * when the last segment of a previous request is
 774                          * received just before this; (3) We are re-sending a
 775                          * request.
 776                          */
 777                         if (qp->s_num_rd_atomic >= qp->s_max_rd_atomic) {
 778                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
 779                                 goto bail;
 780                         }
 781                         if (newreq) {
 782                                 struct tid_rdma_flow *flow =
 783                                         &req->flows[req->setup_head];
 784
 785                                 /*
 786                                  * Set up s_sge as it is needed for TID
 787                                  * allocation. However, if the pages have been
 788                                  * walked and mapped, skip it. An earlier try
 789                                  * has failed to allocate the TID entries.
 790                                  */
 791                                 if (!flow->npagesets) {
 792                                         qp->s_sge.sge = wqe->sg_list[0];
 793                                         qp->s_sge.sg_list = wqe->sg_list + 1;
 794                                         qp->s_sge.num_sge = wqe->wr.num_sge;
 795                                         qp->s_sge.total_len = wqe->length;
 796                                         qp->s_len = wqe->length;
 797                                         req->isge = 0;
 798                                         req->clear_tail = req->setup_head;
 799                                         req->flow_idx = req->setup_head;
 800                                         req->state = TID_REQUEST_ACTIVE;
 801                                 }
 802                         } else if (delta == 0) {
 803                                 /* Re-send a request */
 804                                 req->cur_seg = 0;
 805                                 req->comp_seg = 0;
 806                                 req->ack_pending = 0;
 807                                 req->flow_idx = req->clear_tail;
 808                                 req->state = TID_REQUEST_RESEND;
 809                         }
 810                         req->s_next_psn = qp->s_psn;
 811                         /* Read one segment at a time */
 812                         len = min_t(u32, req->seg_len,
 813                                     wqe->length - req->seg_len * req->cur_seg);
 814                         delta = hfi1_build_tid_rdma_read_req(qp, wqe, ohdr,
 815                                                              &bth1, &bth2,
 816                                                              &len);
 817                         if (delta <= 0) {
 818                                 /* Wait for TID space */
 819                                 goto bail;
 820                         }
 821                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 822                                 qp->s_lsn++;
 823                         hwords += delta;
 824                         ss = &wpriv->ss;
 825                         /* Check if this is the last segment */
 826                         if (req->cur_seg >= req->total_segs &&
 827                             ++qp->s_cur == qp->s_size)
 828                                 qp->s_cur = 0;
 829                         break;
 830
 831                 case IB_WR_ATOMIC_CMP_AND_SWP:
 832                 case IB_WR_ATOMIC_FETCH_AND_ADD:
 833                         /*
 834                          * Don't allow more operations to be started
 835                          * than the QP limits allow.
 836                          */
 837                         if (qp->s_num_rd_atomic >=
 838                             qp->s_max_rd_atomic) {
 839                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
 840                                 goto bail;
 841                         }
 842                         qp->s_num_rd_atomic++;
 843                         fallthrough;
 844                 case IB_WR_OPFN:
 845                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
 846                                 qp->s_lsn++;
 847                         if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
 848                             wqe->wr.opcode == IB_WR_OPFN) {
 849                                 qp->s_state = OP(COMPARE_SWAP);
 850                                 put_ib_ateth_swap(wqe->atomic_wr.swap,
 851                                                   &ohdr->u.atomic_eth);
 852                                 put_ib_ateth_compare(wqe->atomic_wr.compare_add,
 853                                                      &ohdr->u.atomic_eth);
 854                         } else {
 855                                 qp->s_state = OP(FETCH_ADD);
 856                                 put_ib_ateth_swap(wqe->atomic_wr.compare_add,
 857                                                   &ohdr->u.atomic_eth);
 858                                 put_ib_ateth_compare(0, &ohdr->u.atomic_eth);
 859                         }
 860                         put_ib_ateth_vaddr(wqe->atomic_wr.remote_addr,
 861                                            &ohdr->u.atomic_eth);
 862                         ohdr->u.atomic_eth.rkey = cpu_to_be32(
 863                                 wqe->atomic_wr.rkey);
 864                         hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
 865                         ss = NULL;
 866                         len = 0;
 867                         bth2 |= IB_BTH_REQ_ACK;
 868                         if (++qp->s_cur == qp->s_size)
 869                                 qp->s_cur = 0;
 870                         break;
 871
 872                 default:
 873                         goto bail;
 874                 }
 875                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ) {
 876                         qp->s_sge.sge = wqe->sg_list[0];
 877                         qp->s_sge.sg_list = wqe->sg_list + 1;
 878                         qp->s_sge.num_sge = wqe->wr.num_sge;
 879                         qp->s_sge.total_len = wqe->length;
 880                         qp->s_len = wqe->length;
 881                 }
 882                 if (newreq) {
 883                         qp->s_tail++;
 884                         if (qp->s_tail >= qp->s_size)
 885                                 qp->s_tail = 0;
 886                 }
 887                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
 888                     wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
 889                         qp->s_psn = wqe->lpsn + 1;
 890                 else if (wqe->wr.opcode == IB_WR_TID_RDMA_READ)
 891                         qp->s_psn = req->s_next_psn;
 892                 else
 893                         qp->s_psn++;
 894                 break;
 895
 896         case OP(RDMA_READ_RESPONSE_FIRST):
 897                 /*
 898                  * qp->s_state is normally set to the opcode of the
 899                  * last packet constructed for new requests and therefore
 900                  * is never set to RDMA read response.
 901                  * RDMA_READ_RESPONSE_FIRST is used by the ACK processing
 902                  * thread to indicate a SEND needs to be restarted from an
 903                  * earlier PSN without interfering with the sending thread.
 904                  * See restart_rc().
 905                  */
 906                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
 907                 fallthrough;
 908         case OP(SEND_FIRST):
 909                 qp->s_state = OP(SEND_MIDDLE);
 910                 fallthrough;
 911         case OP(SEND_MIDDLE):
 912                 bth2 = mask_psn(qp->s_psn++);
 913                 ss = &qp->s_sge;
 914                 len = qp->s_len;
 915                 if (len > pmtu) {
 916                         len = pmtu;
 917                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 918                         break;
 919                 }
 920                 if (wqe->wr.opcode == IB_WR_SEND) {
 921                         qp->s_state = OP(SEND_LAST);
 922                 } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
 923                         qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
 924                         /* Immediate data comes after the BTH */
 925                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 926                         hwords += 1;
 927                 } else {
 928                         qp->s_state = OP(SEND_LAST_WITH_INVALIDATE);
 929                         /* invalidate data comes after the BTH */
 930                         ohdr->u.ieth = cpu_to_be32(wqe->wr.ex.invalidate_rkey);
 931                         hwords += 1;
 932                 }
 933                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 934                         bth0 |= IB_BTH_SOLICITED;
 935                 bth2 |= IB_BTH_REQ_ACK;
 936                 qp->s_cur++;
 937                 if (qp->s_cur >= qp->s_size)
 938                         qp->s_cur = 0;
 939                 break;
 940
 941         case OP(RDMA_READ_RESPONSE_LAST):
 942                 /*
 943                  * qp->s_state is normally set to the opcode of the
 944                  * last packet constructed for new requests and therefore
 945                  * is never set to RDMA read response.
 946                  * RDMA_READ_RESPONSE_LAST is used by the ACK processing
 947                  * thread to indicate a RDMA write needs to be restarted from
 948                  * an earlier PSN without interfering with the sending thread.
 949                  * See restart_rc().
 950                  */
 951                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
 952                 fallthrough;
 953         case OP(RDMA_WRITE_FIRST):
 954                 qp->s_state = OP(RDMA_WRITE_MIDDLE);
 955                 fallthrough;
 956         case OP(RDMA_WRITE_MIDDLE):
 957                 bth2 = mask_psn(qp->s_psn++);
 958                 ss = &qp->s_sge;
 959                 len = qp->s_len;
 960                 if (len > pmtu) {
 961                         len = pmtu;
 962                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
 963                         break;
 964                 }
 965                 if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
 966                         qp->s_state = OP(RDMA_WRITE_LAST);
 967                 } else {
 968                         qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
 969                         /* Immediate data comes after the BTH */
 970                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
 971                         hwords += 1;
 972                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 973                                 bth0 |= IB_BTH_SOLICITED;
 974                 }
 975                 bth2 |= IB_BTH_REQ_ACK;
 976                 qp->s_cur++;
 977                 if (qp->s_cur >= qp->s_size)
 978                         qp->s_cur = 0;
 979                 break;
 980
 981         case OP(RDMA_READ_RESPONSE_MIDDLE):
 982                 /*
 983                  * qp->s_state is normally set to the opcode of the
 984                  * last packet constructed for new requests and therefore
 985                  * is never set to RDMA read response.
 986                  * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing
 987                  * thread to indicate a RDMA read needs to be restarted from
 988                  * an earlier PSN without interfering with the sending thread.
 989                  * See restart_rc().
 990                  */
 991                 len = (delta_psn(qp->s_psn, wqe->psn)) * pmtu;
 992                 put_ib_reth_vaddr(
 993                         wqe->rdma_wr.remote_addr + len,
 994                         &ohdr->u.rc.reth);
 995                 ohdr->u.rc.reth.rkey =
 996                         cpu_to_be32(wqe->rdma_wr.rkey);
 997                 ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len);
 998                 qp->s_state = OP(RDMA_READ_REQUEST);
 999                 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
1000                 bth2 = mask_psn(qp->s_psn) | IB_BTH_REQ_ACK;
1001                 qp->s_psn = wqe->lpsn + 1;
1002                 ss = NULL;
1003                 len = 0;
1004                 qp->s_cur++;
1005                 if (qp->s_cur == qp->s_size)
1006                         qp->s_cur = 0;
1007                 break;
1008
1009         case TID_OP(WRITE_RESP):
1010                 /*
1011                  * This value for s_state is used for restarting a TID RDMA
1012                  * WRITE request. See comment in OP(RDMA_READ_RESPONSE_MIDDLE
1013                  * for more).
1014                  */
1015                 req = wqe_to_tid_req(wqe);
1016                 req->state = TID_REQUEST_RESEND;
1017                 rcu_read_lock();
1018                 remote = rcu_dereference(priv->tid_rdma.remote);
1019                 req->comp_seg = delta_psn(qp->s_psn, wqe->psn);
1020                 len = wqe->length - (req->comp_seg * remote->max_len);
1021                 rcu_read_unlock();
1022
1023                 bth2 = mask_psn(qp->s_psn);
1024                 hwords += hfi1_build_tid_rdma_write_req(qp, wqe, ohdr, &bth1,
1025                                                         &bth2, &len);
1026                 qp->s_psn = wqe->lpsn + 1;
1027                 ss = NULL;
1028                 qp->s_state = TID_OP(WRITE_REQ);
1029                 priv->pending_tid_w_resp += delta_psn(wqe->lpsn, bth2) + 1;
1030                 priv->s_tid_cur = qp->s_cur;
1031                 if (++qp->s_cur == qp->s_size)
1032                         qp->s_cur = 0;
1033                 trace_hfi1_tid_req_make_req_write(qp, 0, wqe->wr.opcode,
1034                                                   wqe->psn, wqe->lpsn, req);
1035                 break;
1036
1037         case TID_OP(READ_RESP):
1038                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ)
1039                         goto bail;
1040                 /* This is used to restart a TID read request */
1041                 req = wqe_to_tid_req(wqe);
1042                 wpriv = wqe->priv;
1043                 /*
1044                  * Back down. The field qp->s_psn has been set to the psn with
1045                  * which the request should be restart. It's OK to use division
1046                  * as this is on the retry path.
1047                  */
1048                 req->cur_seg = delta_psn(qp->s_psn, wqe->psn) / priv->pkts_ps;
1049
1050                 /*
1051                  * The following function need to be redefined to return the
1052                  * status to make sure that we find the flow. At the same
1053                  * time, we can use the req->state change to check if the
1054                  * call succeeds or not.
1055                  */
1056                 req->state = TID_REQUEST_RESEND;
1057                 hfi1_tid_rdma_restart_req(qp, wqe, &bth2);
1058                 if (req->state != TID_REQUEST_ACTIVE) {
1059                         /*
1060                          * Failed to find the flow. Release all allocated tid
1061                          * resources.
1062                          */
1063                         hfi1_kern_exp_rcv_clear_all(req);
1064                         hfi1_kern_clear_hw_flow(priv->rcd, qp);
1065
1066                         hfi1_trdma_send_complete(qp, wqe, IB_WC_LOC_QP_OP_ERR);
1067                         goto bail;
1068                 }
1069                 req->state = TID_REQUEST_RESEND;
1070                 len = min_t(u32, req->seg_len,
1071                             wqe->length - req->seg_len * req->cur_seg);
1072                 flow = &req->flows[req->flow_idx];
1073                 len -= flow->sent;
1074                 req->s_next_psn = flow->flow_state.ib_lpsn + 1;
1075                 delta = hfi1_build_tid_rdma_read_packet(wqe, ohdr, &bth1,
1076                                                         &bth2, &len);
1077                 if (delta <= 0) {
1078                         /* Wait for TID space */
1079                         goto bail;
1080                 }
1081                 hwords += delta;
1082                 ss = &wpriv->ss;
1083                 /* Check if this is the last segment */
1084                 if (req->cur_seg >= req->total_segs &&
1085                     ++qp->s_cur == qp->s_size)
1086                         qp->s_cur = 0;
1087                 qp->s_psn = req->s_next_psn;
1088                 trace_hfi1_tid_req_make_req_read(qp, 0, wqe->wr.opcode,
1089                                                  wqe->psn, wqe->lpsn, req);
1090                 break;
1091         case TID_OP(READ_REQ):
1092                 req = wqe_to_tid_req(wqe);
1093                 delta = cmp_psn(qp->s_psn, wqe->psn);
1094                 /*
1095                  * If the current WR is not TID RDMA READ, or this is the start
1096                  * of a new request, we need to change the qp->s_state so that
1097                  * the request can be set up properly.
1098                  */
1099                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ || delta == 0 ||
1100                     qp->s_cur == qp->s_tail) {
1101                         qp->s_state = OP(RDMA_READ_REQUEST);
1102                         if (delta == 0 || qp->s_cur == qp->s_tail)
1103                                 goto check_s_state;
1104                         else
1105                                 goto bail;
1106                 }
1107
1108                 /* Rate limiting */
1109                 if (qp->s_num_rd_atomic >= qp->s_max_rd_atomic) {
1110                         qp->s_flags |= RVT_S_WAIT_RDMAR;
1111                         goto bail;
1112                 }
1113
1114                 wpriv = wqe->priv;
1115                 /* Read one segment at a time */
1116                 len = min_t(u32, req->seg_len,
1117                             wqe->length - req->seg_len * req->cur_seg);
1118                 delta = hfi1_build_tid_rdma_read_req(qp, wqe, ohdr, &bth1,
1119                                                      &bth2, &len);
1120                 if (delta <= 0) {
1121                         /* Wait for TID space */
1122                         goto bail;
1123                 }
1124                 hwords += delta;
1125                 ss = &wpriv->ss;
1126                 /* Check if this is the last segment */
1127                 if (req->cur_seg >= req->total_segs &&
1128                     ++qp->s_cur == qp->s_size)
1129                         qp->s_cur = 0;
1130                 qp->s_psn = req->s_next_psn;
1131                 trace_hfi1_tid_req_make_req_read(qp, 0, wqe->wr.opcode,
1132                                                  wqe->psn, wqe->lpsn, req);
1133                 break;
1134         }
1135         qp->s_sending_hpsn = bth2;
1136         delta = delta_psn(bth2, wqe->psn);
1137         if (delta && delta % HFI1_PSN_CREDIT == 0 &&
1138             wqe->wr.opcode != IB_WR_TID_RDMA_WRITE)
1139                 bth2 |= IB_BTH_REQ_ACK;
1140         if (qp->s_flags & RVT_S_SEND_ONE) {
1141                 qp->s_flags &= ~RVT_S_SEND_ONE;
1142                 qp->s_flags |= RVT_S_WAIT_ACK;
1143                 bth2 |= IB_BTH_REQ_ACK;
1144         }
1145         qp->s_len -= len;
1146         ps->s_txreq->hdr_dwords = hwords;
1147         ps->s_txreq->sde = priv->s_sde;
1148         ps->s_txreq->ss = ss;
1149         ps->s_txreq->s_cur_size = len;
1150         hfi1_make_ruc_header(
1151                 qp,
1152                 ohdr,
1153                 bth0 | (qp->s_state << 24),
1154                 bth1,
1155                 bth2,
1156                 middle,
1157                 ps);
1158         return 1;
1159
1160 done_free_tx:
1161         hfi1_put_txreq(ps->s_txreq);
1162         ps->s_txreq = NULL;
1163         return 1;
1164
1165 bail:
1166         hfi1_put_txreq(ps->s_txreq);
1167
1168 bail_no_tx:
1169         ps->s_txreq = NULL;
1170         qp->s_flags &= ~RVT_S_BUSY;
1171         /*
1172          * If we didn't get a txreq, the QP will be woken up later to try
1173          * again. Set the flags to indicate which work item to wake
1174          * up.
1175          */
1176         iowait_set_flag(&priv->s_iowait, IOWAIT_PENDING_IB);
1177         return 0;
1178 }
1179
1180 static inline void hfi1_make_bth_aeth(struct rvt_qp *qp,
1181                                       struct ib_other_headers *ohdr,
1182                                       u32 bth0, u32 bth1)
1183 {
1184         if (qp->r_nak_state)
1185                 ohdr->u.aeth = cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
1186                                             (qp->r_nak_state <<
1187                                              IB_AETH_CREDIT_SHIFT));
1188         else
1189                 ohdr->u.aeth = rvt_compute_aeth(qp);
1190
1191         ohdr->bth[0] = cpu_to_be32(bth0);
1192         ohdr->bth[1] = cpu_to_be32(bth1 | qp->remote_qpn);
1193         ohdr->bth[2] = cpu_to_be32(mask_psn(qp->r_ack_psn));
1194 }
1195
1196 static inline void hfi1_queue_rc_ack(struct hfi1_packet *packet, bool is_fecn)
1197 {
1198         struct rvt_qp *qp = packet->qp;
1199         struct hfi1_ibport *ibp;
1200         unsigned long flags;
1201
1202         spin_lock_irqsave(&qp->s_lock, flags);
1203         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
1204                 goto unlock;
1205         ibp = rcd_to_iport(packet->rcd);
1206         this_cpu_inc(*ibp->rvp.rc_qacks);
1207         qp->s_flags |= RVT_S_ACK_PENDING | RVT_S_RESP_PENDING;
1208         qp->s_nak_state = qp->r_nak_state;
1209         qp->s_ack_psn = qp->r_ack_psn;
1210         if (is_fecn)
1211                 qp->s_flags |= RVT_S_ECN;
1212
1213         /* Schedule the send tasklet. */
1214         hfi1_schedule_send(qp);
1215 unlock:
1216         spin_unlock_irqrestore(&qp->s_lock, flags);
1217 }
1218
1219 static inline void hfi1_make_rc_ack_9B(struct hfi1_packet *packet,
1220                                        struct hfi1_opa_header *opa_hdr,
1221                                        u8 sc5, bool is_fecn,
1222                                        u64 *pbc_flags, u32 *hwords,
1223                                        u32 *nwords)
1224 {
1225         struct rvt_qp *qp = packet->qp;
1226         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
1227         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1228         struct ib_header *hdr = &opa_hdr->ibh;
1229         struct ib_other_headers *ohdr;
1230         u16 lrh0 = HFI1_LRH_BTH;
1231         u16 pkey;
1232         u32 bth0, bth1;
1233
1234         opa_hdr->hdr_type = HFI1_PKT_TYPE_9B;
1235         ohdr = &hdr->u.oth;
1236         /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4 */
1237         *hwords = 6;
1238
1239         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)) {
1240                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
1241                                          rdma_ah_read_grh(&qp->remote_ah_attr),
1242                                          *hwords - 2, SIZE_OF_CRC);
1243                 ohdr = &hdr->u.l.oth;
1244                 lrh0 = HFI1_LRH_GRH;
1245         }
1246         /* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
1247         *pbc_flags |= ((!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT);
1248
1249         /* read pkey_index w/o lock (its atomic) */
1250         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
1251
1252         lrh0 |= (sc5 & IB_SC_MASK) << IB_SC_SHIFT |
1253                 (rdma_ah_get_sl(&qp->remote_ah_attr) & IB_SL_MASK) <<
1254                         IB_SL_SHIFT;
1255
1256         hfi1_make_ib_hdr(hdr, lrh0, *hwords + SIZE_OF_CRC,
1257                          opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr), 9B),
1258                          ppd->lid | rdma_ah_get_path_bits(&qp->remote_ah_attr));
1259
1260         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
1261         if (qp->s_mig_state == IB_MIG_MIGRATED)
1262                 bth0 |= IB_BTH_MIG_REQ;
1263         bth1 = (!!is_fecn) << IB_BECN_SHIFT;
1264         /*
1265          * Inline ACKs go out without the use of the Verbs send engine, so
1266          * we need to set the STL Verbs Extended bit here
1267          */
1268         bth1 |= HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT;
1269         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
1270 }
1271
1272 static inline void hfi1_make_rc_ack_16B(struct hfi1_packet *packet,
1273                                         struct hfi1_opa_header *opa_hdr,
1274                                         u8 sc5, bool is_fecn,
1275                                         u64 *pbc_flags, u32 *hwords,
1276                                         u32 *nwords)
1277 {
1278         struct rvt_qp *qp = packet->qp;
1279         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
1280         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1281         struct hfi1_16b_header *hdr = &opa_hdr->opah;
1282         struct ib_other_headers *ohdr;
1283         u32 bth0, bth1 = 0;
1284         u16 len, pkey;
1285         bool becn = is_fecn;
1286         u8 l4 = OPA_16B_L4_IB_LOCAL;
1287         u8 extra_bytes;
1288
1289         opa_hdr->hdr_type = HFI1_PKT_TYPE_16B;
1290         ohdr = &hdr->u.oth;
1291         /* header size in 32-bit words 16B LRH+BTH+AETH = (16+12+4)/4 */
1292         *hwords = 8;
1293         extra_bytes = hfi1_get_16b_padding(*hwords << 2, 0);
1294         *nwords = SIZE_OF_CRC + ((extra_bytes + SIZE_OF_LT) >> 2);
1295
1296         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
1297             hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))) {
1298                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
1299                                          rdma_ah_read_grh(&qp->remote_ah_attr),
1300                                          *hwords - 4, *nwords);
1301                 ohdr = &hdr->u.l.oth;
1302                 l4 = OPA_16B_L4_IB_GLOBAL;
1303         }
1304         *pbc_flags |= PBC_PACKET_BYPASS | PBC_INSERT_BYPASS_ICRC;
1305
1306         /* read pkey_index w/o lock (its atomic) */
1307         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
1308
1309         /* Convert dwords to flits */
1310         len = (*hwords + *nwords) >> 1;
1311
1312         hfi1_make_16b_hdr(hdr, ppd->lid |
1313                           (rdma_ah_get_path_bits(&qp->remote_ah_attr) &
1314                           ((1 << ppd->lmc) - 1)),
1315                           opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr),
1316                                       16B), len, pkey, becn, 0, l4, sc5);
1317
1318         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
1319         bth0 |= extra_bytes << 20;
1320         if (qp->s_mig_state == IB_MIG_MIGRATED)
1321                 bth1 = OPA_BTH_MIG_REQ;
1322         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
1323 }
1324
1325 typedef void (*hfi1_make_rc_ack)(struct hfi1_packet *packet,
1326                                  struct hfi1_opa_header *opa_hdr,
1327                                  u8 sc5, bool is_fecn,
1328                                  u64 *pbc_flags, u32 *hwords,
1329                                  u32 *nwords);
1330
1331 /* We support only two types - 9B and 16B for now */
1332 static const hfi1_make_rc_ack hfi1_make_rc_ack_tbl[2] = {
1333         [HFI1_PKT_TYPE_9B] = &hfi1_make_rc_ack_9B,
1334         [HFI1_PKT_TYPE_16B] = &hfi1_make_rc_ack_16B
1335 };
1336
1337 /*
1338  * hfi1_send_rc_ack - Construct an ACK packet and send it
1339  *
1340  * This is called from hfi1_rc_rcv() and handle_receive_interrupt().
1341  * Note that RDMA reads and atomics are handled in the
1342  * send side QP state and send engine.
1343  */
1344 void hfi1_send_rc_ack(struct hfi1_packet *packet, bool is_fecn)
1345 {
1346         struct hfi1_ctxtdata *rcd = packet->rcd;
1347         struct rvt_qp *qp = packet->qp;
1348         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
1349         struct hfi1_qp_priv *priv = qp->priv;
1350         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1351         u8 sc5 = ibp->sl_to_sc[rdma_ah_get_sl(&qp->remote_ah_attr)];
1352         u64 pbc, pbc_flags = 0;
1353         u32 hwords = 0;
1354         u32 nwords = 0;
1355         u32 plen;
1356         struct pio_buf *pbuf;
1357         struct hfi1_opa_header opa_hdr;
1358
1359         /* clear the defer count */
1360         qp->r_adefered = 0;
1361
1362         /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
1363         if (qp->s_flags & RVT_S_RESP_PENDING) {
1364                 hfi1_queue_rc_ack(packet, is_fecn);
1365                 return;
1366         }
1367
1368         /* Ensure s_rdma_ack_cnt changes are committed */
1369         if (qp->s_rdma_ack_cnt) {
1370                 hfi1_queue_rc_ack(packet, is_fecn);
1371                 return;
1372         }
1373
1374         /* Don't try to send ACKs if the link isn't ACTIVE */
1375         if (driver_lstate(ppd) != IB_PORT_ACTIVE)
1376                 return;
1377
1378         /* Make the appropriate header */
1379         hfi1_make_rc_ack_tbl[priv->hdr_type](packet, &opa_hdr, sc5, is_fecn,
1380                                              &pbc_flags, &hwords, &nwords);
1381
1382         plen = 2 /* PBC */ + hwords + nwords;
1383         pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps,
1384                          sc_to_vlt(ppd->dd, sc5), plen);
1385         pbuf = sc_buffer_alloc(rcd->sc, plen, NULL, NULL);
1386         if (IS_ERR_OR_NULL(pbuf)) {
1387                 /*
1388                  * We have no room to send at the moment.  Pass
1389                  * responsibility for sending the ACK to the send engine
1390                  * so that when enough buffer space becomes available,
1391                  * the ACK is sent ahead of other outgoing packets.
1392                  */
1393                 hfi1_queue_rc_ack(packet, is_fecn);
1394                 return;
1395         }
1396         trace_ack_output_ibhdr(dd_from_ibdev(qp->ibqp.device),
1397                                &opa_hdr, ib_is_sc5(sc5));
1398
1399         /* write the pbc and data */
1400         ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc,
1401                                  (priv->hdr_type == HFI1_PKT_TYPE_9B ?
1402                                  (void *)&opa_hdr.ibh :
1403                                  (void *)&opa_hdr.opah), hwords);
1404         return;
1405 }
1406
1407 /**
1408  * update_num_rd_atomic - update the qp->s_num_rd_atomic
1409  * @qp: the QP
1410  * @psn: the packet sequence number to restart at
1411  * @wqe: the wqe
1412  *
1413  * This is called from reset_psn() to update qp->s_num_rd_atomic
1414  * for the current wqe.
1415  * Called at interrupt level with the QP s_lock held.
1416  */
1417 static void update_num_rd_atomic(struct rvt_qp *qp, u32 psn,
1418                                  struct rvt_swqe *wqe)
1419 {
1420         u32 opcode = wqe->wr.opcode;
1421
1422         if (opcode == IB_WR_RDMA_READ ||
1423             opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1424             opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
1425                 qp->s_num_rd_atomic++;
1426         } else if (opcode == IB_WR_TID_RDMA_READ) {
1427                 struct tid_rdma_request *req = wqe_to_tid_req(wqe);
1428                 struct hfi1_qp_priv *priv = qp->priv;
1429
1430                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
1431                         u32 cur_seg;
1432
1433                         cur_seg = (psn - wqe->psn) / priv->pkts_ps;
1434                         req->ack_pending = cur_seg - req->comp_seg;
1435                         priv->pending_tid_r_segs += req->ack_pending;
1436                         qp->s_num_rd_atomic += req->ack_pending;
1437                         trace_hfi1_tid_req_update_num_rd_atomic(qp, 0,
1438                                                                 wqe->wr.opcode,
1439                                                                 wqe->psn,
1440                                                                 wqe->lpsn,
1441                                                                 req);
1442                 } else {
1443                         priv->pending_tid_r_segs += req->total_segs;
1444                         qp->s_num_rd_atomic += req->total_segs;
1445                 }
1446         }
1447 }
1448
1449 /**
1450  * reset_psn - reset the QP state to send starting from PSN
1451  * @qp: the QP
1452  * @psn: the packet sequence number to restart at
1453  *
1454  * This is called from hfi1_rc_rcv() to process an incoming RC ACK
1455  * for the given QP.
1456  * Called at interrupt level with the QP s_lock held.
1457  */
1458 static void reset_psn(struct rvt_qp *qp, u32 psn)
1459 {
1460         u32 n = qp->s_acked;
1461         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, n);
1462         u32 opcode;
1463         struct hfi1_qp_priv *priv = qp->priv;
1464
1465         lockdep_assert_held(&qp->s_lock);
1466         qp->s_cur = n;
1467         priv->pending_tid_r_segs = 0;
1468         priv->pending_tid_w_resp = 0;
1469         qp->s_num_rd_atomic = 0;
1470
1471         /*
1472          * If we are starting the request from the beginning,
1473          * let the normal send code handle initialization.
1474          */
1475         if (cmp_psn(psn, wqe->psn) <= 0) {
1476                 qp->s_state = OP(SEND_LAST);
1477                 goto done;
1478         }
1479         update_num_rd_atomic(qp, psn, wqe);
1480
1481         /* Find the work request opcode corresponding to the given PSN. */
1482         for (;;) {
1483                 int diff;
1484
1485                 if (++n == qp->s_size)
1486                         n = 0;
1487                 if (n == qp->s_tail)
1488                         break;
1489                 wqe = rvt_get_swqe_ptr(qp, n);
1490                 diff = cmp_psn(psn, wqe->psn);
1491                 if (diff < 0) {
1492                         /* Point wqe back to the previous one*/
1493                         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1494                         break;
1495                 }
1496                 qp->s_cur = n;
1497                 /*
1498                  * If we are starting the request from the beginning,
1499                  * let the normal send code handle initialization.
1500                  */
1501                 if (diff == 0) {
1502                         qp->s_state = OP(SEND_LAST);
1503                         goto done;
1504                 }
1505
1506                 update_num_rd_atomic(qp, psn, wqe);
1507         }
1508         opcode = wqe->wr.opcode;
1509
1510         /*
1511          * Set the state to restart in the middle of a request.
1512          * Don't change the s_sge, s_cur_sge, or s_cur_size.
1513          * See hfi1_make_rc_req().
1514          */
1515         switch (opcode) {
1516         case IB_WR_SEND:
1517         case IB_WR_SEND_WITH_IMM:
1518                 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
1519                 break;
1520
1521         case IB_WR_RDMA_WRITE:
1522         case IB_WR_RDMA_WRITE_WITH_IMM:
1523                 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
1524                 break;
1525
1526         case IB_WR_TID_RDMA_WRITE:
1527                 qp->s_state = TID_OP(WRITE_RESP);
1528                 break;
1529
1530         case IB_WR_RDMA_READ:
1531                 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
1532                 break;
1533
1534         case IB_WR_TID_RDMA_READ:
1535                 qp->s_state = TID_OP(READ_RESP);
1536                 break;
1537
1538         default:
1539                 /*
1540                  * This case shouldn't happen since its only
1541                  * one PSN per req.
1542                  */
1543                 qp->s_state = OP(SEND_LAST);
1544         }
1545 done:
1546         priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
1547         qp->s_psn = psn;
1548         /*
1549          * Set RVT_S_WAIT_PSN as rc_complete() may start the timer
1550          * asynchronously before the send engine can get scheduled.
1551          * Doing it in hfi1_make_rc_req() is too late.
1552          */
1553         if ((cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) &&
1554             (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0))
1555                 qp->s_flags |= RVT_S_WAIT_PSN;
1556         qp->s_flags &= ~HFI1_S_AHG_VALID;
1557         trace_hfi1_sender_reset_psn(qp);
1558 }
1559
1560 /*
1561  * Back up requester to resend the last un-ACKed request.
1562  * The QP r_lock and s_lock should be held and interrupts disabled.
1563  */
1564 void hfi1_restart_rc(struct rvt_qp *qp, u32 psn, int wait)
1565 {
1566         struct hfi1_qp_priv *priv = qp->priv;
1567         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1568         struct hfi1_ibport *ibp;
1569
1570         lockdep_assert_held(&qp->r_lock);
1571         lockdep_assert_held(&qp->s_lock);
1572         trace_hfi1_sender_restart_rc(qp);
1573         if (qp->s_retry == 0) {
1574                 if (qp->s_mig_state == IB_MIG_ARMED) {
1575                         hfi1_migrate_qp(qp);
1576                         qp->s_retry = qp->s_retry_cnt;
1577                 } else if (qp->s_last == qp->s_acked) {
1578                         /*
1579                          * We need special handling for the OPFN request WQEs as
1580                          * they are not allowed to generate real user errors
1581                          */
1582                         if (wqe->wr.opcode == IB_WR_OPFN) {
1583                                 struct hfi1_ibport *ibp =
1584                                         to_iport(qp->ibqp.device, qp->port_num);
1585                                 /*
1586                                  * Call opfn_conn_reply() with capcode and
1587                                  * remaining data as 0 to close out the
1588                                  * current request
1589                                  */
1590                                 opfn_conn_reply(qp, priv->opfn.curr);
1591                                 wqe = do_rc_completion(qp, wqe, ibp);
1592                                 qp->s_flags &= ~RVT_S_WAIT_ACK;
1593                         } else {
1594                                 trace_hfi1_tid_write_sender_restart_rc(qp, 0);
1595                                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ) {
1596                                         struct tid_rdma_request *req;
1597
1598                                         req = wqe_to_tid_req(wqe);
1599                                         hfi1_kern_exp_rcv_clear_all(req);
1600                                         hfi1_kern_clear_hw_flow(priv->rcd, qp);
1601                                 }
1602
1603                                 hfi1_trdma_send_complete(qp, wqe,
1604                                                          IB_WC_RETRY_EXC_ERR);
1605                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1606                         }
1607                         return;
1608                 } else { /* need to handle delayed completion */
1609                         return;
1610                 }
1611         } else {
1612                 qp->s_retry--;
1613         }
1614
1615         ibp = to_iport(qp->ibqp.device, qp->port_num);
1616         if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1617             wqe->wr.opcode == IB_WR_TID_RDMA_READ)
1618                 ibp->rvp.n_rc_resends++;
1619         else
1620                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
1621
1622         qp->s_flags &= ~(RVT_S_WAIT_FENCE | RVT_S_WAIT_RDMAR |
1623                          RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_PSN |
1624                          RVT_S_WAIT_ACK | HFI1_S_WAIT_TID_RESP);
1625         if (wait)
1626                 qp->s_flags |= RVT_S_SEND_ONE;
1627         reset_psn(qp, psn);
1628 }
1629
1630 /*
1631  * Set qp->s_sending_psn to the next PSN after the given one.
1632  * This would be psn+1 except when RDMA reads or TID RDMA ops
1633  * are present.
1634  */
1635 static void reset_sending_psn(struct rvt_qp *qp, u32 psn)
1636 {
1637         struct rvt_swqe *wqe;
1638         u32 n = qp->s_last;
1639
1640         lockdep_assert_held(&qp->s_lock);
1641         /* Find the work request corresponding to the given PSN. */
1642         for (;;) {
1643                 wqe = rvt_get_swqe_ptr(qp, n);
1644                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
1645                         if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1646                             wqe->wr.opcode == IB_WR_TID_RDMA_READ ||
1647                             wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
1648                                 qp->s_sending_psn = wqe->lpsn + 1;
1649                         else
1650                                 qp->s_sending_psn = psn + 1;
1651                         break;
1652                 }
1653                 if (++n == qp->s_size)
1654                         n = 0;
1655                 if (n == qp->s_tail)
1656                         break;
1657         }
1658 }
1659
1660 /**
1661  * hfi1_rc_verbs_aborted - handle abort status
1662  * @qp: the QP
1663  * @opah: the opa header
1664  *
1665  * This code modifies both ACK bit in BTH[2]
1666  * and the s_flags to go into send one mode.
1667  *
1668  * This serves to throttle the send engine to only
1669  * send a single packet in the likely case the
1670  * a link has gone down.
1671  */
1672 void hfi1_rc_verbs_aborted(struct rvt_qp *qp, struct hfi1_opa_header *opah)
1673 {
1674         struct ib_other_headers *ohdr = hfi1_get_rc_ohdr(opah);
1675         u8 opcode = ib_bth_get_opcode(ohdr);
1676         u32 psn;
1677
1678         /* ignore responses */
1679         if ((opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1680              opcode <= OP(ATOMIC_ACKNOWLEDGE)) ||
1681             opcode == TID_OP(READ_RESP) ||
1682             opcode == TID_OP(WRITE_RESP))
1683                 return;
1684
1685         psn = ib_bth_get_psn(ohdr) | IB_BTH_REQ_ACK;
1686         ohdr->bth[2] = cpu_to_be32(psn);
1687         qp->s_flags |= RVT_S_SEND_ONE;
1688 }
1689
1690 /*
1691  * This should be called with the QP s_lock held and interrupts disabled.
1692  */
1693 void hfi1_rc_send_complete(struct rvt_qp *qp, struct hfi1_opa_header *opah)
1694 {
1695         struct ib_other_headers *ohdr;
1696         struct hfi1_qp_priv *priv = qp->priv;
1697         struct rvt_swqe *wqe;
1698         u32 opcode, head, tail;
1699         u32 psn;
1700         struct tid_rdma_request *req;
1701
1702         lockdep_assert_held(&qp->s_lock);
1703         if (!(ib_rvt_state_ops[qp->state] & RVT_SEND_OR_FLUSH_OR_RECV_OK))
1704                 return;
1705
1706         ohdr = hfi1_get_rc_ohdr(opah);
1707         opcode = ib_bth_get_opcode(ohdr);
1708         if ((opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1709              opcode <= OP(ATOMIC_ACKNOWLEDGE)) ||
1710             opcode == TID_OP(READ_RESP) ||
1711             opcode == TID_OP(WRITE_RESP)) {
1712                 WARN_ON(!qp->s_rdma_ack_cnt);
1713                 qp->s_rdma_ack_cnt--;
1714                 return;
1715         }
1716
1717         psn = ib_bth_get_psn(ohdr);
1718         /*
1719          * Don't attempt to reset the sending PSN for packets in the
1720          * KDETH PSN space since the PSN does not match anything.
1721          */
1722         if (opcode != TID_OP(WRITE_DATA) &&
1723             opcode != TID_OP(WRITE_DATA_LAST) &&
1724             opcode != TID_OP(ACK) && opcode != TID_OP(RESYNC))
1725                 reset_sending_psn(qp, psn);
1726
1727         /* Handle TID RDMA WRITE packets differently */
1728         if (opcode >= TID_OP(WRITE_REQ) &&
1729             opcode <= TID_OP(WRITE_DATA_LAST)) {
1730                 head = priv->s_tid_head;
1731                 tail = priv->s_tid_cur;
1732                 /*
1733                  * s_tid_cur is set to s_tid_head in the case, where
1734                  * a new TID RDMA request is being started and all
1735                  * previous ones have been completed.
1736                  * Therefore, we need to do a secondary check in order
1737                  * to properly determine whether we should start the
1738                  * RC timer.
1739                  */
1740                 wqe = rvt_get_swqe_ptr(qp, tail);
1741                 req = wqe_to_tid_req(wqe);
1742                 if (head == tail && req->comp_seg < req->total_segs) {
1743                         if (tail == 0)
1744                                 tail = qp->s_size - 1;
1745                         else
1746                                 tail -= 1;
1747                 }
1748         } else {
1749                 head = qp->s_tail;
1750                 tail = qp->s_acked;
1751         }
1752
1753         /*
1754          * Start timer after a packet requesting an ACK has been sent and
1755          * there are still requests that haven't been acked.
1756          */
1757         if ((psn & IB_BTH_REQ_ACK) && tail != head &&
1758             opcode != TID_OP(WRITE_DATA) && opcode != TID_OP(WRITE_DATA_LAST) &&
1759             opcode != TID_OP(RESYNC) &&
1760             !(qp->s_flags &
1761               (RVT_S_TIMER | RVT_S_WAIT_RNR | RVT_S_WAIT_PSN)) &&
1762             (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
1763                 if (opcode == TID_OP(READ_REQ))
1764                         rvt_add_retry_timer_ext(qp, priv->timeout_shift);
1765                 else
1766                         rvt_add_retry_timer(qp);
1767         }
1768
1769         /* Start TID RDMA ACK timer */
1770         if ((opcode == TID_OP(WRITE_DATA) ||
1771              opcode == TID_OP(WRITE_DATA_LAST) ||
1772              opcode == TID_OP(RESYNC)) &&
1773             (psn & IB_BTH_REQ_ACK) &&
1774             !(priv->s_flags & HFI1_S_TID_RETRY_TIMER) &&
1775             (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
1776                 /*
1777                  * The TID RDMA ACK packet could be received before this
1778                  * function is called. Therefore, add the timer only if TID
1779                  * RDMA ACK packets are actually pending.
1780                  */
1781                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1782                 req = wqe_to_tid_req(wqe);
1783                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
1784                     req->ack_seg < req->cur_seg)
1785                         hfi1_add_tid_retry_timer(qp);
1786         }
1787
1788         while (qp->s_last != qp->s_acked) {
1789                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
1790                 if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 &&
1791                     cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
1792                         break;
1793                 trdma_clean_swqe(qp, wqe);
1794                 trace_hfi1_qp_send_completion(qp, wqe, qp->s_last);
1795                 rvt_qp_complete_swqe(qp,
1796                                      wqe,
1797                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1798                                      IB_WC_SUCCESS);
1799         }
1800         /*
1801          * If we were waiting for sends to complete before re-sending,
1802          * and they are now complete, restart sending.
1803          */
1804         trace_hfi1_sendcomplete(qp, psn);
1805         if (qp->s_flags & RVT_S_WAIT_PSN &&
1806             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1807                 qp->s_flags &= ~RVT_S_WAIT_PSN;
1808                 qp->s_sending_psn = qp->s_psn;
1809                 qp->s_sending_hpsn = qp->s_psn - 1;
1810                 hfi1_schedule_send(qp);
1811         }
1812 }
1813
1814 static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
1815 {
1816         qp->s_last_psn = psn;
1817 }
1818
1819 /*
1820  * Generate a SWQE completion.
1821  * This is similar to hfi1_send_complete but has to check to be sure
1822  * that the SGEs are not being referenced if the SWQE is being resent.
1823  */
1824 struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
1825                                   struct rvt_swqe *wqe,
1826                                   struct hfi1_ibport *ibp)
1827 {
1828         struct hfi1_qp_priv *priv = qp->priv;
1829
1830         lockdep_assert_held(&qp->s_lock);
1831         /*
1832          * Don't decrement refcount and don't generate a
1833          * completion if the SWQE is being resent until the send
1834          * is finished.
1835          */
1836         trace_hfi1_rc_completion(qp, wqe->lpsn);
1837         if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 ||
1838             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1839                 trdma_clean_swqe(qp, wqe);
1840                 trace_hfi1_qp_send_completion(qp, wqe, qp->s_last);
1841                 rvt_qp_complete_swqe(qp,
1842                                      wqe,
1843                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1844                                      IB_WC_SUCCESS);
1845         } else {
1846                 struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1847
1848                 this_cpu_inc(*ibp->rvp.rc_delayed_comp);
1849                 /*
1850                  * If send progress not running attempt to progress
1851                  * SDMA queue.
1852                  */
1853                 if (ppd->dd->flags & HFI1_HAS_SEND_DMA) {
1854                         struct sdma_engine *engine;
1855                         u8 sl = rdma_ah_get_sl(&qp->remote_ah_attr);
1856                         u8 sc5;
1857
1858                         /* For now use sc to find engine */
1859                         sc5 = ibp->sl_to_sc[sl];
1860                         engine = qp_to_sdma_engine(qp, sc5);
1861                         sdma_engine_progress_schedule(engine);
1862                 }
1863         }
1864
1865         qp->s_retry = qp->s_retry_cnt;
1866         /*
1867          * Don't update the last PSN if the request being completed is
1868          * a TID RDMA WRITE request.
1869          * Completion of the TID RDMA WRITE requests are done by the
1870          * TID RDMA ACKs and as such could be for a request that has
1871          * already been ACKed as far as the IB state machine is
1872          * concerned.
1873          */
1874         if (wqe->wr.opcode != IB_WR_TID_RDMA_WRITE)
1875                 update_last_psn(qp, wqe->lpsn);
1876
1877         /*
1878          * If we are completing a request which is in the process of
1879          * being resent, we can stop re-sending it since we know the
1880          * responder has already seen it.
1881          */
1882         if (qp->s_acked == qp->s_cur) {
1883                 if (++qp->s_cur >= qp->s_size)
1884                         qp->s_cur = 0;
1885                 qp->s_acked = qp->s_cur;
1886                 wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1887                 if (qp->s_acked != qp->s_tail) {
1888                         qp->s_state = OP(SEND_LAST);
1889                         qp->s_psn = wqe->psn;
1890                 }
1891         } else {
1892                 if (++qp->s_acked >= qp->s_size)
1893                         qp->s_acked = 0;
1894                 if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur)
1895                         qp->s_draining = 0;
1896                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1897         }
1898         if (priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) {
1899                 priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
1900                 hfi1_schedule_send(qp);
1901         }
1902         return wqe;
1903 }
1904
1905 static void set_restart_qp(struct rvt_qp *qp, struct hfi1_ctxtdata *rcd)
1906 {
1907         /* Retry this request. */
1908         if (!(qp->r_flags & RVT_R_RDMAR_SEQ)) {
1909                 qp->r_flags |= RVT_R_RDMAR_SEQ;
1910                 hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
1911                 if (list_empty(&qp->rspwait)) {
1912                         qp->r_flags |= RVT_R_RSP_SEND;
1913                         rvt_get_qp(qp);
1914                         list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1915                 }
1916         }
1917 }
1918
1919 /**
1920  * update_qp_retry_state - Update qp retry state.
1921  * @qp: the QP
1922  * @psn: the packet sequence number of the TID RDMA WRITE RESP.
1923  * @spsn:  The start psn for the given TID RDMA WRITE swqe.
1924  * @lpsn:  The last psn for the given TID RDMA WRITE swqe.
1925  *
1926  * This function is called to update the qp retry state upon
1927  * receiving a TID WRITE RESP after the qp is scheduled to retry
1928  * a request.
1929  */
1930 static void update_qp_retry_state(struct rvt_qp *qp, u32 psn, u32 spsn,
1931                                   u32 lpsn)
1932 {
1933         struct hfi1_qp_priv *qpriv = qp->priv;
1934
1935         qp->s_psn = psn + 1;
1936         /*
1937          * If this is the first TID RDMA WRITE RESP packet for the current
1938          * request, change the s_state so that the retry will be processed
1939          * correctly. Similarly, if this is the last TID RDMA WRITE RESP
1940          * packet, change the s_state and advance the s_cur.
1941          */
1942         if (cmp_psn(psn, lpsn) >= 0) {
1943                 qp->s_cur = qpriv->s_tid_cur + 1;
1944                 if (qp->s_cur >= qp->s_size)
1945                         qp->s_cur = 0;
1946                 qp->s_state = TID_OP(WRITE_REQ);
1947         } else  if (!cmp_psn(psn, spsn)) {
1948                 qp->s_cur = qpriv->s_tid_cur;
1949                 qp->s_state = TID_OP(WRITE_RESP);
1950         }
1951 }
1952
1953 /*
1954  * do_rc_ack - process an incoming RC ACK
1955  * @qp: the QP the ACK came in on
1956  * @psn: the packet sequence number of the ACK
1957  * @opcode: the opcode of the request that resulted in the ACK
1958  *
1959  * This is called from rc_rcv_resp() to process an incoming RC ACK
1960  * for the given QP.
1961  * May be called at interrupt level, with the QP s_lock held.
1962  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
1963  */
1964 int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
1965               u64 val, struct hfi1_ctxtdata *rcd)
1966 {
1967         struct hfi1_ibport *ibp;
1968         enum ib_wc_status status;
1969         struct hfi1_qp_priv *qpriv = qp->priv;
1970         struct rvt_swqe *wqe;
1971         int ret = 0;
1972         u32 ack_psn;
1973         int diff;
1974         struct rvt_dev_info *rdi;
1975
1976         lockdep_assert_held(&qp->s_lock);
1977         /*
1978          * Note that NAKs implicitly ACK outstanding SEND and RDMA write
1979          * requests and implicitly NAK RDMA read and atomic requests issued
1980          * before the NAK'ed request.  The MSN won't include the NAK'ed
1981          * request but will include an ACK'ed request(s).
1982          */
1983         ack_psn = psn;
1984         if (aeth >> IB_AETH_NAK_SHIFT)
1985                 ack_psn--;
1986         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1987         ibp = rcd_to_iport(rcd);
1988
1989         /*
1990          * The MSN might be for a later WQE than the PSN indicates so
1991          * only complete WQEs that the PSN finishes.
1992          */
1993         while ((diff = delta_psn(ack_psn, wqe->lpsn)) >= 0) {
1994                 /*
1995                  * RDMA_READ_RESPONSE_ONLY is a special case since
1996                  * we want to generate completion events for everything
1997                  * before the RDMA read, copy the data, then generate
1998                  * the completion for the read.
1999                  */
2000                 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
2001                     opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
2002                     diff == 0) {
2003                         ret = 1;
2004                         goto bail_stop;
2005                 }
2006                 /*
2007                  * If this request is a RDMA read or atomic, and the ACK is
2008                  * for a later operation, this ACK NAKs the RDMA read or
2009                  * atomic.  In other words, only a RDMA_READ_LAST or ONLY
2010                  * can ACK a RDMA read and likewise for atomic ops.  Note
2011                  * that the NAK case can only happen if relaxed ordering is
2012                  * used and requests are sent after an RDMA read or atomic
2013                  * is sent but before the response is received.
2014                  */
2015                 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
2016                      (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
2017                     (wqe->wr.opcode == IB_WR_TID_RDMA_READ &&
2018                      (opcode != TID_OP(READ_RESP) || diff != 0)) ||
2019                     ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2020                       wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
2021                      (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0)) ||
2022                     (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2023                      (delta_psn(psn, qp->s_last_psn) != 1))) {
2024                         set_restart_qp(qp, rcd);
2025                         /*
2026                          * No need to process the ACK/NAK since we are
2027                          * restarting an earlier request.
2028                          */
2029                         goto bail_stop;
2030                 }
2031                 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2032                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
2033                         u64 *vaddr = wqe->sg_list[0].vaddr;
2034                         *vaddr = val;
2035                 }
2036                 if (wqe->wr.opcode == IB_WR_OPFN)
2037                         opfn_conn_reply(qp, val);
2038
2039                 if (qp->s_num_rd_atomic &&
2040                     (wqe->wr.opcode == IB_WR_RDMA_READ ||
2041                      wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2042                      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
2043                         qp->s_num_rd_atomic--;
2044                         /* Restart sending task if fence is complete */
2045                         if ((qp->s_flags & RVT_S_WAIT_FENCE) &&
2046                             !qp->s_num_rd_atomic) {
2047                                 qp->s_flags &= ~(RVT_S_WAIT_FENCE |
2048                                                  RVT_S_WAIT_ACK);
2049                                 hfi1_schedule_send(qp);
2050                         } else if (qp->s_flags & RVT_S_WAIT_RDMAR) {
2051                                 qp->s_flags &= ~(RVT_S_WAIT_RDMAR |
2052                                                  RVT_S_WAIT_ACK);
2053                                 hfi1_schedule_send(qp);
2054                         }
2055                 }
2056
2057                 /*
2058                  * TID RDMA WRITE requests will be completed by the TID RDMA
2059                  * ACK packet handler (see tid_rdma.c).
2060                  */
2061                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
2062                         break;
2063
2064                 wqe = do_rc_completion(qp, wqe, ibp);
2065                 if (qp->s_acked == qp->s_tail)
2066                         break;
2067         }
2068
2069         trace_hfi1_rc_ack_do(qp, aeth, psn, wqe);
2070         trace_hfi1_sender_do_rc_ack(qp);
2071         switch (aeth >> IB_AETH_NAK_SHIFT) {
2072         case 0:         /* ACK */
2073                 this_cpu_inc(*ibp->rvp.rc_acks);
2074                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ) {
2075                         if (wqe_to_tid_req(wqe)->ack_pending)
2076                                 rvt_mod_retry_timer_ext(qp,
2077                                                         qpriv->timeout_shift);
2078                         else
2079                                 rvt_stop_rc_timers(qp);
2080                 } else if (qp->s_acked != qp->s_tail) {
2081                         struct rvt_swqe *__w = NULL;
2082
2083                         if (qpriv->s_tid_cur != HFI1_QP_WQE_INVALID)
2084                                 __w = rvt_get_swqe_ptr(qp, qpriv->s_tid_cur);
2085
2086                         /*
2087                          * Stop timers if we've received all of the TID RDMA
2088                          * WRITE * responses.
2089                          */
2090                         if (__w && __w->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2091                             opcode == TID_OP(WRITE_RESP)) {
2092                                 /*
2093                                  * Normally, the loop above would correctly
2094                                  * process all WQEs from s_acked onward and
2095                                  * either complete them or check for correct
2096                                  * PSN sequencing.
2097                                  * However, for TID RDMA, due to pipelining,
2098                                  * the response may not be for the request at
2099                                  * s_acked so the above look would just be
2100                                  * skipped. This does not allow for checking
2101                                  * the PSN sequencing. It has to be done
2102                                  * separately.
2103                                  */
2104                                 if (cmp_psn(psn, qp->s_last_psn + 1)) {
2105                                         set_restart_qp(qp, rcd);
2106                                         goto bail_stop;
2107                                 }
2108                                 /*
2109                                  * If the psn is being resent, stop the
2110                                  * resending.
2111                                  */
2112                                 if (qp->s_cur != qp->s_tail &&
2113                                     cmp_psn(qp->s_psn, psn) <= 0)
2114                                         update_qp_retry_state(qp, psn,
2115                                                               __w->psn,
2116                                                               __w->lpsn);
2117                                 else if (--qpriv->pending_tid_w_resp)
2118                                         rvt_mod_retry_timer(qp);
2119                                 else
2120                                         rvt_stop_rc_timers(qp);
2121                         } else {
2122                                 /*
2123                                  * We are expecting more ACKs so
2124                                  * mod the retry timer.
2125                                  */
2126                                 rvt_mod_retry_timer(qp);
2127                                 /*
2128                                  * We can stop re-sending the earlier packets
2129                                  * and continue with the next packet the
2130                                  * receiver wants.
2131                                  */
2132                                 if (cmp_psn(qp->s_psn, psn) <= 0)
2133                                         reset_psn(qp, psn + 1);
2134                         }
2135                 } else {
2136                         /* No more acks - kill all timers */
2137                         rvt_stop_rc_timers(qp);
2138                         if (cmp_psn(qp->s_psn, psn) <= 0) {
2139                                 qp->s_state = OP(SEND_LAST);
2140                                 qp->s_psn = psn + 1;
2141                         }
2142                 }
2143                 if (qp->s_flags & RVT_S_WAIT_ACK) {
2144                         qp->s_flags &= ~RVT_S_WAIT_ACK;
2145                         hfi1_schedule_send(qp);
2146                 }
2147                 rvt_get_credit(qp, aeth);
2148                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
2149                 qp->s_retry = qp->s_retry_cnt;
2150                 /*
2151                  * If the current request is a TID RDMA WRITE request and the
2152                  * response is not a TID RDMA WRITE RESP packet, s_last_psn
2153                  * can't be advanced.
2154                  */
2155                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2156                     opcode != TID_OP(WRITE_RESP) &&
2157                     cmp_psn(psn, wqe->psn) >= 0)
2158                         return 1;
2159                 update_last_psn(qp, psn);
2160                 return 1;
2161
2162         case 1:         /* RNR NAK */
2163                 ibp->rvp.n_rnr_naks++;
2164                 if (qp->s_acked == qp->s_tail)
2165                         goto bail_stop;
2166                 if (qp->s_flags & RVT_S_WAIT_RNR)
2167                         goto bail_stop;
2168                 rdi = ib_to_rvt(qp->ibqp.device);
2169                 if (!(rdi->post_parms[wqe->wr.opcode].flags &
2170                        RVT_OPERATION_IGN_RNR_CNT)) {
2171                         if (qp->s_rnr_retry == 0) {
2172                                 status = IB_WC_RNR_RETRY_EXC_ERR;
2173                                 goto class_b;
2174                         }
2175                         if (qp->s_rnr_retry_cnt < 7 && qp->s_rnr_retry_cnt > 0)
2176                                 qp->s_rnr_retry--;
2177                 }
2178
2179                 /*
2180                  * The last valid PSN is the previous PSN. For TID RDMA WRITE
2181                  * request, s_last_psn should be incremented only when a TID
2182                  * RDMA WRITE RESP is received to avoid skipping lost TID RDMA
2183                  * WRITE RESP packets.
2184                  */
2185                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE) {
2186                         reset_psn(qp, qp->s_last_psn + 1);
2187                 } else {
2188                         update_last_psn(qp, psn - 1);
2189                         reset_psn(qp, psn);
2190                 }
2191
2192                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
2193                 qp->s_flags &= ~(RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_ACK);
2194                 rvt_stop_rc_timers(qp);
2195                 rvt_add_rnr_timer(qp, aeth);
2196                 return 0;
2197
2198         case 3:         /* NAK */
2199                 if (qp->s_acked == qp->s_tail)
2200                         goto bail_stop;
2201                 /* The last valid PSN is the previous PSN. */
2202                 update_last_psn(qp, psn - 1);
2203                 switch ((aeth >> IB_AETH_CREDIT_SHIFT) &
2204                         IB_AETH_CREDIT_MASK) {
2205                 case 0: /* PSN sequence error */
2206                         ibp->rvp.n_seq_naks++;
2207                         /*
2208                          * Back up to the responder's expected PSN.
2209                          * Note that we might get a NAK in the middle of an
2210                          * RDMA READ response which terminates the RDMA
2211                          * READ.
2212                          */
2213                         hfi1_restart_rc(qp, psn, 0);
2214                         hfi1_schedule_send(qp);
2215                         break;
2216
2217                 case 1: /* Invalid Request */
2218                         status = IB_WC_REM_INV_REQ_ERR;
2219                         ibp->rvp.n_other_naks++;
2220                         goto class_b;
2221
2222                 case 2: /* Remote Access Error */
2223                         status = IB_WC_REM_ACCESS_ERR;
2224                         ibp->rvp.n_other_naks++;
2225                         goto class_b;
2226
2227                 case 3: /* Remote Operation Error */
2228                         status = IB_WC_REM_OP_ERR;
2229                         ibp->rvp.n_other_naks++;
2230 class_b:
2231                         if (qp->s_last == qp->s_acked) {
2232                                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ)
2233                                         hfi1_kern_read_tid_flow_free(qp);
2234
2235                                 hfi1_trdma_send_complete(qp, wqe, status);
2236                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
2237                         }
2238                         break;
2239
2240                 default:
2241                         /* Ignore other reserved NAK error codes */
2242                         goto reserved;
2243                 }
2244                 qp->s_retry = qp->s_retry_cnt;
2245                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
2246                 goto bail_stop;
2247
2248         default:                /* 2: reserved */
2249 reserved:
2250                 /* Ignore reserved NAK codes. */
2251                 goto bail_stop;
2252         }
2253         /* cannot be reached  */
2254 bail_stop:
2255         rvt_stop_rc_timers(qp);
2256         return ret;
2257 }
2258
2259 /*
2260  * We have seen an out of sequence RDMA read middle or last packet.
2261  * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE.
2262  */
2263 static void rdma_seq_err(struct rvt_qp *qp, struct hfi1_ibport *ibp, u32 psn,
2264                          struct hfi1_ctxtdata *rcd)
2265 {
2266         struct rvt_swqe *wqe;
2267
2268         lockdep_assert_held(&qp->s_lock);
2269         /* Remove QP from retry timer */
2270         rvt_stop_rc_timers(qp);
2271
2272         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2273
2274         while (cmp_psn(psn, wqe->lpsn) > 0) {
2275                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
2276                     wqe->wr.opcode == IB_WR_TID_RDMA_READ ||
2277                     wqe->wr.opcode == IB_WR_TID_RDMA_WRITE ||
2278                     wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2279                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
2280                         break;
2281                 wqe = do_rc_completion(qp, wqe, ibp);
2282         }
2283
2284         ibp->rvp.n_rdma_seq++;
2285         qp->r_flags |= RVT_R_RDMAR_SEQ;
2286         hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
2287         if (list_empty(&qp->rspwait)) {
2288                 qp->r_flags |= RVT_R_RSP_SEND;
2289                 rvt_get_qp(qp);
2290                 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
2291         }
2292 }
2293
2294 /**
2295  * rc_rcv_resp - process an incoming RC response packet
2296  * @packet: data packet information
2297  *
2298  * This is called from hfi1_rc_rcv() to process an incoming RC response
2299  * packet for the given QP.
2300  * Called at interrupt level.
2301  */
2302 static void rc_rcv_resp(struct hfi1_packet *packet)
2303 {
2304         struct hfi1_ctxtdata *rcd = packet->rcd;
2305         void *data = packet->payload;
2306         u32 tlen = packet->tlen;
2307         struct rvt_qp *qp = packet->qp;
2308         struct hfi1_ibport *ibp;
2309         struct ib_other_headers *ohdr = packet->ohdr;
2310         struct rvt_swqe *wqe;
2311         enum ib_wc_status status;
2312         unsigned long flags;
2313         int diff;
2314         u64 val;
2315         u32 aeth;
2316         u32 psn = ib_bth_get_psn(packet->ohdr);
2317         u32 pmtu = qp->pmtu;
2318         u16 hdrsize = packet->hlen;
2319         u8 opcode = packet->opcode;
2320         u8 pad = packet->pad;
2321         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
2322
2323         spin_lock_irqsave(&qp->s_lock, flags);
2324         trace_hfi1_ack(qp, psn);
2325
2326         /* Ignore invalid responses. */
2327         if (cmp_psn(psn, READ_ONCE(qp->s_next_psn)) >= 0)
2328                 goto ack_done;
2329
2330         /* Ignore duplicate responses. */
2331         diff = cmp_psn(psn, qp->s_last_psn);
2332         if (unlikely(diff <= 0)) {
2333                 /* Update credits for "ghost" ACKs */
2334                 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
2335                         aeth = be32_to_cpu(ohdr->u.aeth);
2336                         if ((aeth >> IB_AETH_NAK_SHIFT) == 0)
2337                                 rvt_get_credit(qp, aeth);
2338                 }
2339                 goto ack_done;
2340         }
2341
2342         /*
2343          * Skip everything other than the PSN we expect, if we are waiting
2344          * for a reply to a restarted RDMA read or atomic op.
2345          */
2346         if (qp->r_flags & RVT_R_RDMAR_SEQ) {
2347                 if (cmp_psn(psn, qp->s_last_psn + 1) != 0)
2348                         goto ack_done;
2349                 qp->r_flags &= ~RVT_R_RDMAR_SEQ;
2350         }
2351
2352         if (unlikely(qp->s_acked == qp->s_tail))
2353                 goto ack_done;
2354         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2355         status = IB_WC_SUCCESS;
2356
2357         switch (opcode) {
2358         case OP(ACKNOWLEDGE):
2359         case OP(ATOMIC_ACKNOWLEDGE):
2360         case OP(RDMA_READ_RESPONSE_FIRST):
2361                 aeth = be32_to_cpu(ohdr->u.aeth);
2362                 if (opcode == OP(ATOMIC_ACKNOWLEDGE))
2363                         val = ib_u64_get(&ohdr->u.at.atomic_ack_eth);
2364                 else
2365                         val = 0;
2366                 if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) ||
2367                     opcode != OP(RDMA_READ_RESPONSE_FIRST))
2368                         goto ack_done;
2369                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2370                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2371                         goto ack_op_err;
2372                 /*
2373                  * If this is a response to a resent RDMA read, we
2374                  * have to be careful to copy the data to the right
2375                  * location.
2376                  */
2377                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
2378                                                   wqe, psn, pmtu);
2379                 goto read_middle;
2380
2381         case OP(RDMA_READ_RESPONSE_MIDDLE):
2382                 /* no AETH, no ACK */
2383                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
2384                         goto ack_seq_err;
2385                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2386                         goto ack_op_err;
2387 read_middle:
2388                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
2389                         goto ack_len_err;
2390                 if (unlikely(pmtu >= qp->s_rdma_read_len))
2391                         goto ack_len_err;
2392
2393                 /*
2394                  * We got a response so update the timeout.
2395                  * 4.096 usec. * (1 << qp->timeout)
2396                  */
2397                 rvt_mod_retry_timer(qp);
2398                 if (qp->s_flags & RVT_S_WAIT_ACK) {
2399                         qp->s_flags &= ~RVT_S_WAIT_ACK;
2400                         hfi1_schedule_send(qp);
2401                 }
2402
2403                 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
2404                         qp->s_retry = qp->s_retry_cnt;
2405
2406                 /*
2407                  * Update the RDMA receive state but do the copy w/o
2408                  * holding the locks and blocking interrupts.
2409                  */
2410                 qp->s_rdma_read_len -= pmtu;
2411                 update_last_psn(qp, psn);
2412                 spin_unlock_irqrestore(&qp->s_lock, flags);
2413                 rvt_copy_sge(qp, &qp->s_rdma_read_sge,
2414                              data, pmtu, false, false);
2415                 goto bail;
2416
2417         case OP(RDMA_READ_RESPONSE_ONLY):
2418                 aeth = be32_to_cpu(ohdr->u.aeth);
2419                 if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd))
2420                         goto ack_done;
2421                 /*
2422                  * Check that the data size is >= 0 && <= pmtu.
2423                  * Remember to account for ICRC (4).
2424                  */
2425                 if (unlikely(tlen < (hdrsize + extra_bytes)))
2426                         goto ack_len_err;
2427                 /*
2428                  * If this is a response to a resent RDMA read, we
2429                  * have to be careful to copy the data to the right
2430                  * location.
2431                  */
2432                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2433                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
2434                                                   wqe, psn, pmtu);
2435                 goto read_last;
2436
2437         case OP(RDMA_READ_RESPONSE_LAST):
2438                 /* ACKs READ req. */
2439                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
2440                         goto ack_seq_err;
2441                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2442                         goto ack_op_err;
2443                 /*
2444                  * Check that the data size is >= 1 && <= pmtu.
2445                  * Remember to account for ICRC (4).
2446                  */
2447                 if (unlikely(tlen <= (hdrsize + extra_bytes)))
2448                         goto ack_len_err;
2449 read_last:
2450                 tlen -= hdrsize + extra_bytes;
2451                 if (unlikely(tlen != qp->s_rdma_read_len))
2452                         goto ack_len_err;
2453                 aeth = be32_to_cpu(ohdr->u.aeth);
2454                 rvt_copy_sge(qp, &qp->s_rdma_read_sge,
2455                              data, tlen, false, false);
2456                 WARN_ON(qp->s_rdma_read_sge.num_sge);
2457                 (void)do_rc_ack(qp, aeth, psn,
2458                                  OP(RDMA_READ_RESPONSE_LAST), 0, rcd);
2459                 goto ack_done;
2460         }
2461
2462 ack_op_err:
2463         status = IB_WC_LOC_QP_OP_ERR;
2464         goto ack_err;
2465
2466 ack_seq_err:
2467         ibp = rcd_to_iport(rcd);
2468         rdma_seq_err(qp, ibp, psn, rcd);
2469         goto ack_done;
2470
2471 ack_len_err:
2472         status = IB_WC_LOC_LEN_ERR;
2473 ack_err:
2474         if (qp->s_last == qp->s_acked) {
2475                 rvt_send_complete(qp, wqe, status);
2476                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
2477         }
2478 ack_done:
2479         spin_unlock_irqrestore(&qp->s_lock, flags);
2480 bail:
2481         return;
2482 }
2483
2484 static inline void rc_cancel_ack(struct rvt_qp *qp)
2485 {
2486         qp->r_adefered = 0;
2487         if (list_empty(&qp->rspwait))
2488                 return;
2489         list_del_init(&qp->rspwait);
2490         qp->r_flags &= ~RVT_R_RSP_NAK;
2491         rvt_put_qp(qp);
2492 }
2493
2494 /**
2495  * rc_rcv_error - process an incoming duplicate or error RC packet
2496  * @ohdr: the other headers for this packet
2497  * @data: the packet data
2498  * @qp: the QP for this packet
2499  * @opcode: the opcode for this packet
2500  * @psn: the packet sequence number for this packet
2501  * @diff: the difference between the PSN and the expected PSN
2502  * @rcd: the receive context
2503  *
2504  * This is called from hfi1_rc_rcv() to process an unexpected
2505  * incoming RC packet for the given QP.
2506  * Called at interrupt level.
2507  * Return 1 if no more processing is needed; otherwise return 0 to
2508  * schedule a response to be sent.
2509  */
2510 static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
2511                                  struct rvt_qp *qp, u32 opcode, u32 psn,
2512                                  int diff, struct hfi1_ctxtdata *rcd)
2513 {
2514         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2515         struct rvt_ack_entry *e;
2516         unsigned long flags;
2517         u8 prev;
2518         u8 mra; /* most recent ACK */
2519         bool old_req;
2520
2521         trace_hfi1_rcv_error(qp, psn);
2522         if (diff > 0) {
2523                 /*
2524                  * Packet sequence error.
2525                  * A NAK will ACK earlier sends and RDMA writes.
2526                  * Don't queue the NAK if we already sent one.
2527                  */
2528                 if (!qp->r_nak_state) {
2529                         ibp->rvp.n_rc_seqnak++;
2530                         qp->r_nak_state = IB_NAK_PSN_ERROR;
2531                         /* Use the expected PSN. */
2532                         qp->r_ack_psn = qp->r_psn;
2533                         /*
2534                          * Wait to send the sequence NAK until all packets
2535                          * in the receive queue have been processed.
2536                          * Otherwise, we end up propagating congestion.
2537                          */
2538                         rc_defered_ack(rcd, qp);
2539                 }
2540                 goto done;
2541         }
2542
2543         /*
2544          * Handle a duplicate request.  Don't re-execute SEND, RDMA
2545          * write or atomic op.  Don't NAK errors, just silently drop
2546          * the duplicate request.  Note that r_sge, r_len, and
2547          * r_rcv_len may be in use so don't modify them.
2548          *
2549          * We are supposed to ACK the earliest duplicate PSN but we
2550          * can coalesce an outstanding duplicate ACK.  We have to
2551          * send the earliest so that RDMA reads can be restarted at
2552          * the requester's expected PSN.
2553          *
2554          * First, find where this duplicate PSN falls within the
2555          * ACKs previously sent.
2556          * old_req is true if there is an older response that is scheduled
2557          * to be sent before sending this one.
2558          */
2559         e = NULL;
2560         old_req = true;
2561         ibp->rvp.n_rc_dupreq++;
2562
2563         spin_lock_irqsave(&qp->s_lock, flags);
2564
2565         e = find_prev_entry(qp, psn, &prev, &mra, &old_req);
2566
2567         switch (opcode) {
2568         case OP(RDMA_READ_REQUEST): {
2569                 struct ib_reth *reth;
2570                 u32 offset;
2571                 u32 len;
2572
2573                 /*
2574                  * If we didn't find the RDMA read request in the ack queue,
2575                  * we can ignore this request.
2576                  */
2577                 if (!e || e->opcode != OP(RDMA_READ_REQUEST))
2578                         goto unlock_done;
2579                 /* RETH comes after BTH */
2580                 reth = &ohdr->u.rc.reth;
2581                 /*
2582                  * Address range must be a subset of the original
2583                  * request and start on pmtu boundaries.
2584                  * We reuse the old ack_queue slot since the requester
2585                  * should not back up and request an earlier PSN for the
2586                  * same request.
2587                  */
2588                 offset = delta_psn(psn, e->psn) * qp->pmtu;
2589                 len = be32_to_cpu(reth->length);
2590                 if (unlikely(offset + len != e->rdma_sge.sge_length))
2591                         goto unlock_done;
2592                 release_rdma_sge_mr(e);
2593                 if (len != 0) {
2594                         u32 rkey = be32_to_cpu(reth->rkey);
2595                         u64 vaddr = get_ib_reth_vaddr(reth);
2596                         int ok;
2597
2598                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
2599                                          IB_ACCESS_REMOTE_READ);
2600                         if (unlikely(!ok))
2601                                 goto unlock_done;
2602                 } else {
2603                         e->rdma_sge.vaddr = NULL;
2604                         e->rdma_sge.length = 0;
2605                         e->rdma_sge.sge_length = 0;
2606                 }
2607                 e->psn = psn;
2608                 if (old_req)
2609                         goto unlock_done;
2610                 if (qp->s_acked_ack_queue == qp->s_tail_ack_queue)
2611                         qp->s_acked_ack_queue = prev;
2612                 qp->s_tail_ack_queue = prev;
2613                 break;
2614         }
2615
2616         case OP(COMPARE_SWAP):
2617         case OP(FETCH_ADD): {
2618                 /*
2619                  * If we didn't find the atomic request in the ack queue
2620                  * or the send engine is already backed up to send an
2621                  * earlier entry, we can ignore this request.
2622                  */
2623                 if (!e || e->opcode != (u8)opcode || old_req)
2624                         goto unlock_done;
2625                 if (qp->s_tail_ack_queue == qp->s_acked_ack_queue)
2626                         qp->s_acked_ack_queue = prev;
2627                 qp->s_tail_ack_queue = prev;
2628                 break;
2629         }
2630
2631         default:
2632                 /*
2633                  * Ignore this operation if it doesn't request an ACK
2634                  * or an earlier RDMA read or atomic is going to be resent.
2635                  */
2636                 if (!(psn & IB_BTH_REQ_ACK) || old_req)
2637                         goto unlock_done;
2638                 /*
2639                  * Resend the most recent ACK if this request is
2640                  * after all the previous RDMA reads and atomics.
2641                  */
2642                 if (mra == qp->r_head_ack_queue) {
2643                         spin_unlock_irqrestore(&qp->s_lock, flags);
2644                         qp->r_nak_state = 0;
2645                         qp->r_ack_psn = qp->r_psn - 1;
2646                         goto send_ack;
2647                 }
2648
2649                 /*
2650                  * Resend the RDMA read or atomic op which
2651                  * ACKs this duplicate request.
2652                  */
2653                 if (qp->s_tail_ack_queue == qp->s_acked_ack_queue)
2654                         qp->s_acked_ack_queue = mra;
2655                 qp->s_tail_ack_queue = mra;
2656                 break;
2657         }
2658         qp->s_ack_state = OP(ACKNOWLEDGE);
2659         qp->s_flags |= RVT_S_RESP_PENDING;
2660         qp->r_nak_state = 0;
2661         hfi1_schedule_send(qp);
2662
2663 unlock_done:
2664         spin_unlock_irqrestore(&qp->s_lock, flags);
2665 done:
2666         return 1;
2667
2668 send_ack:
2669         return 0;
2670 }
2671
2672 static void log_cca_event(struct hfi1_pportdata *ppd, u8 sl, u32 rlid,
2673                           u32 lqpn, u32 rqpn, u8 svc_type)
2674 {
2675         struct opa_hfi1_cong_log_event_internal *cc_event;
2676         unsigned long flags;
2677
2678         if (sl >= OPA_MAX_SLS)
2679                 return;
2680
2681         spin_lock_irqsave(&ppd->cc_log_lock, flags);
2682
2683         ppd->threshold_cong_event_map[sl / 8] |= 1 << (sl % 8);
2684         ppd->threshold_event_counter++;
2685
2686         cc_event = &ppd->cc_events[ppd->cc_log_idx++];
2687         if (ppd->cc_log_idx == OPA_CONG_LOG_ELEMS)
2688                 ppd->cc_log_idx = 0;
2689         cc_event->lqpn = lqpn & RVT_QPN_MASK;
2690         cc_event->rqpn = rqpn & RVT_QPN_MASK;
2691         cc_event->sl = sl;
2692         cc_event->svc_type = svc_type;
2693         cc_event->rlid = rlid;
2694         /* keep timestamp in units of 1.024 usec */
2695         cc_event->timestamp = ktime_get_ns() / 1024;
2696
2697         spin_unlock_irqrestore(&ppd->cc_log_lock, flags);
2698 }
2699
2700 void process_becn(struct hfi1_pportdata *ppd, u8 sl, u32 rlid, u32 lqpn,
2701                   u32 rqpn, u8 svc_type)
2702 {
2703         struct cca_timer *cca_timer;
2704         u16 ccti, ccti_incr, ccti_timer, ccti_limit;
2705         u8 trigger_threshold;
2706         struct cc_state *cc_state;
2707         unsigned long flags;
2708
2709         if (sl >= OPA_MAX_SLS)
2710                 return;
2711
2712         cc_state = get_cc_state(ppd);
2713
2714         if (!cc_state)
2715                 return;
2716
2717         /*
2718          * 1) increase CCTI (for this SL)
2719          * 2) select IPG (i.e., call set_link_ipg())
2720          * 3) start timer
2721          */
2722         ccti_limit = cc_state->cct.ccti_limit;
2723         ccti_incr = cc_state->cong_setting.entries[sl].ccti_increase;
2724         ccti_timer = cc_state->cong_setting.entries[sl].ccti_timer;
2725         trigger_threshold =
2726                 cc_state->cong_setting.entries[sl].trigger_threshold;
2727
2728         spin_lock_irqsave(&ppd->cca_timer_lock, flags);
2729
2730         cca_timer = &ppd->cca_timer[sl];
2731         if (cca_timer->ccti < ccti_limit) {
2732                 if (cca_timer->ccti + ccti_incr <= ccti_limit)
2733                         cca_timer->ccti += ccti_incr;
2734                 else
2735                         cca_timer->ccti = ccti_limit;
2736                 set_link_ipg(ppd);
2737         }
2738
2739         ccti = cca_timer->ccti;
2740
2741         if (!hrtimer_active(&cca_timer->hrtimer)) {
2742                 /* ccti_timer is in units of 1.024 usec */
2743                 unsigned long nsec = 1024 * ccti_timer;
2744
2745                 hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec),
2746                               HRTIMER_MODE_REL_PINNED);
2747         }
2748
2749         spin_unlock_irqrestore(&ppd->cca_timer_lock, flags);
2750
2751         if ((trigger_threshold != 0) && (ccti >= trigger_threshold))
2752                 log_cca_event(ppd, sl, rlid, lqpn, rqpn, svc_type);
2753 }
2754
2755 /**
2756  * hfi1_rc_rcv - process an incoming RC packet
2757  * @packet: data packet information
2758  *
2759  * This is called from qp_rcv() to process an incoming RC packet
2760  * for the given QP.
2761  * May be called at interrupt level.
2762  */
2763 void hfi1_rc_rcv(struct hfi1_packet *packet)
2764 {
2765         struct hfi1_ctxtdata *rcd = packet->rcd;
2766         void *data = packet->payload;
2767         u32 tlen = packet->tlen;
2768         struct rvt_qp *qp = packet->qp;
2769         struct hfi1_qp_priv *qpriv = qp->priv;
2770         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2771         struct ib_other_headers *ohdr = packet->ohdr;
2772         u32 opcode = packet->opcode;
2773         u32 hdrsize = packet->hlen;
2774         u32 psn = ib_bth_get_psn(packet->ohdr);
2775         u32 pad = packet->pad;
2776         struct ib_wc wc;
2777         u32 pmtu = qp->pmtu;
2778         int diff;
2779         struct ib_reth *reth;
2780         unsigned long flags;
2781         int ret;
2782         bool copy_last = false, fecn;
2783         u32 rkey;
2784         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
2785
2786         lockdep_assert_held(&qp->r_lock);
2787
2788         if (hfi1_ruc_check_hdr(ibp, packet))
2789                 return;
2790
2791         fecn = process_ecn(qp, packet);
2792         opfn_trigger_conn_request(qp, be32_to_cpu(ohdr->bth[1]));
2793
2794         /*
2795          * Process responses (ACKs) before anything else.  Note that the
2796          * packet sequence number will be for something in the send work
2797          * queue rather than the expected receive packet sequence number.
2798          * In other words, this QP is the requester.
2799          */
2800         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
2801             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
2802                 rc_rcv_resp(packet);
2803                 return;
2804         }
2805
2806         /* Compute 24 bits worth of difference. */
2807         diff = delta_psn(psn, qp->r_psn);
2808         if (unlikely(diff)) {
2809                 if (rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd))
2810                         return;
2811                 goto send_ack;
2812         }
2813
2814         /* Check for opcode sequence errors. */
2815         switch (qp->r_state) {
2816         case OP(SEND_FIRST):
2817         case OP(SEND_MIDDLE):
2818                 if (opcode == OP(SEND_MIDDLE) ||
2819                     opcode == OP(SEND_LAST) ||
2820                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2821                     opcode == OP(SEND_LAST_WITH_INVALIDATE))
2822                         break;
2823                 goto nack_inv;
2824
2825         case OP(RDMA_WRITE_FIRST):
2826         case OP(RDMA_WRITE_MIDDLE):
2827                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
2828                     opcode == OP(RDMA_WRITE_LAST) ||
2829                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2830                         break;
2831                 goto nack_inv;
2832
2833         default:
2834                 if (opcode == OP(SEND_MIDDLE) ||
2835                     opcode == OP(SEND_LAST) ||
2836                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2837                     opcode == OP(SEND_LAST_WITH_INVALIDATE) ||
2838                     opcode == OP(RDMA_WRITE_MIDDLE) ||
2839                     opcode == OP(RDMA_WRITE_LAST) ||
2840                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2841                         goto nack_inv;
2842                 /*
2843                  * Note that it is up to the requester to not send a new
2844                  * RDMA read or atomic operation before receiving an ACK
2845                  * for the previous operation.
2846                  */
2847                 break;
2848         }
2849
2850         if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
2851                 rvt_comm_est(qp);
2852
2853         /* OK, process the packet. */
2854         switch (opcode) {
2855         case OP(SEND_FIRST):
2856                 ret = rvt_get_rwqe(qp, false);
2857                 if (ret < 0)
2858                         goto nack_op_err;
2859                 if (!ret)
2860                         goto rnr_nak;
2861                 qp->r_rcv_len = 0;
2862                 fallthrough;
2863         case OP(SEND_MIDDLE):
2864         case OP(RDMA_WRITE_MIDDLE):
2865 send_middle:
2866                 /* Check for invalid length PMTU or posted rwqe len. */
2867                 /*
2868                  * There will be no padding for 9B packet but 16B packets
2869                  * will come in with some padding since we always add
2870                  * CRC and LT bytes which will need to be flit aligned
2871                  */
2872                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
2873                         goto nack_inv;
2874                 qp->r_rcv_len += pmtu;
2875                 if (unlikely(qp->r_rcv_len > qp->r_len))
2876                         goto nack_inv;
2877                 rvt_copy_sge(qp, &qp->r_sge, data, pmtu, true, false);
2878                 break;
2879
2880         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
2881                 /* consume RWQE */
2882                 ret = rvt_get_rwqe(qp, true);
2883                 if (ret < 0)
2884                         goto nack_op_err;
2885                 if (!ret)
2886                         goto rnr_nak;
2887                 goto send_last_imm;
2888
2889         case OP(SEND_ONLY):
2890         case OP(SEND_ONLY_WITH_IMMEDIATE):
2891         case OP(SEND_ONLY_WITH_INVALIDATE):
2892                 ret = rvt_get_rwqe(qp, false);
2893                 if (ret < 0)
2894                         goto nack_op_err;
2895                 if (!ret)
2896                         goto rnr_nak;
2897                 qp->r_rcv_len = 0;
2898                 if (opcode == OP(SEND_ONLY))
2899                         goto no_immediate_data;
2900                 if (opcode == OP(SEND_ONLY_WITH_INVALIDATE))
2901                         goto send_last_inv;
2902                 fallthrough;    /* for SEND_ONLY_WITH_IMMEDIATE */
2903         case OP(SEND_LAST_WITH_IMMEDIATE):
2904 send_last_imm:
2905                 wc.ex.imm_data = ohdr->u.imm_data;
2906                 wc.wc_flags = IB_WC_WITH_IMM;
2907                 goto send_last;
2908         case OP(SEND_LAST_WITH_INVALIDATE):
2909 send_last_inv:
2910                 rkey = be32_to_cpu(ohdr->u.ieth);
2911                 if (rvt_invalidate_rkey(qp, rkey))
2912                         goto no_immediate_data;
2913                 wc.ex.invalidate_rkey = rkey;
2914                 wc.wc_flags = IB_WC_WITH_INVALIDATE;
2915                 goto send_last;
2916         case OP(RDMA_WRITE_LAST):
2917                 copy_last = rvt_is_user_qp(qp);
2918                 fallthrough;
2919         case OP(SEND_LAST):
2920 no_immediate_data:
2921                 wc.wc_flags = 0;
2922                 wc.ex.imm_data = 0;
2923 send_last:
2924                 /* Check for invalid length. */
2925                 /* LAST len should be >= 1 */
2926                 if (unlikely(tlen < (hdrsize + extra_bytes)))
2927                         goto nack_inv;
2928                 /* Don't count the CRC(and padding and LT byte for 16B). */
2929                 tlen -= (hdrsize + extra_bytes);
2930                 wc.byte_len = tlen + qp->r_rcv_len;
2931                 if (unlikely(wc.byte_len > qp->r_len))
2932                         goto nack_inv;
2933                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, copy_last);
2934                 rvt_put_ss(&qp->r_sge);
2935                 qp->r_msn++;
2936                 if (!__test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
2937                         break;
2938                 wc.wr_id = qp->r_wr_id;
2939                 wc.status = IB_WC_SUCCESS;
2940                 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
2941                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
2942                         wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
2943                 else
2944                         wc.opcode = IB_WC_RECV;
2945                 wc.qp = &qp->ibqp;
2946                 wc.src_qp = qp->remote_qpn;
2947                 wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
2948                 /*
2949                  * It seems that IB mandates the presence of an SL in a
2950                  * work completion only for the UD transport (see section
2951                  * 11.4.2 of IBTA Vol. 1).
2952                  *
2953                  * However, the way the SL is chosen below is consistent
2954                  * with the way that IB/qib works and is trying avoid
2955                  * introducing incompatibilities.
2956                  *
2957                  * See also OPA Vol. 1, section 9.7.6, and table 9-17.
2958                  */
2959                 wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
2960                 /* zero fields that are N/A */
2961                 wc.vendor_err = 0;
2962                 wc.pkey_index = 0;
2963                 wc.dlid_path_bits = 0;
2964                 wc.port_num = 0;
2965                 /* Signal completion event if the solicited bit is set. */
2966                 rvt_recv_cq(qp, &wc, ib_bth_is_solicited(ohdr));
2967                 break;
2968
2969         case OP(RDMA_WRITE_ONLY):
2970                 copy_last = rvt_is_user_qp(qp);
2971                 fallthrough;
2972         case OP(RDMA_WRITE_FIRST):
2973         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
2974                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
2975                         goto nack_inv;
2976                 /* consume RWQE */
2977                 reth = &ohdr->u.rc.reth;
2978                 qp->r_len = be32_to_cpu(reth->length);
2979                 qp->r_rcv_len = 0;
2980                 qp->r_sge.sg_list = NULL;
2981                 if (qp->r_len != 0) {
2982                         u32 rkey = be32_to_cpu(reth->rkey);
2983                         u64 vaddr = get_ib_reth_vaddr(reth);
2984                         int ok;
2985
2986                         /* Check rkey & NAK */
2987                         ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr,
2988                                          rkey, IB_ACCESS_REMOTE_WRITE);
2989                         if (unlikely(!ok))
2990                                 goto nack_acc;
2991                         qp->r_sge.num_sge = 1;
2992                 } else {
2993                         qp->r_sge.num_sge = 0;
2994                         qp->r_sge.sge.mr = NULL;
2995                         qp->r_sge.sge.vaddr = NULL;
2996                         qp->r_sge.sge.length = 0;
2997                         qp->r_sge.sge.sge_length = 0;
2998                 }
2999                 if (opcode == OP(RDMA_WRITE_FIRST))
3000                         goto send_middle;
3001                 else if (opcode == OP(RDMA_WRITE_ONLY))
3002                         goto no_immediate_data;
3003                 ret = rvt_get_rwqe(qp, true);
3004                 if (ret < 0)
3005                         goto nack_op_err;
3006                 if (!ret) {
3007                         /* peer will send again */
3008                         rvt_put_ss(&qp->r_sge);
3009                         goto rnr_nak;
3010                 }
3011                 wc.ex.imm_data = ohdr->u.rc.imm_data;
3012                 wc.wc_flags = IB_WC_WITH_IMM;
3013                 goto send_last;
3014
3015         case OP(RDMA_READ_REQUEST): {
3016                 struct rvt_ack_entry *e;
3017                 u32 len;
3018                 u8 next;
3019
3020                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
3021                         goto nack_inv;
3022                 next = qp->r_head_ack_queue + 1;
3023                 /* s_ack_queue is size rvt_size_atomic()+1 so use > not >= */
3024                 if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
3025                         next = 0;
3026                 spin_lock_irqsave(&qp->s_lock, flags);
3027                 if (unlikely(next == qp->s_acked_ack_queue)) {
3028                         if (!qp->s_ack_queue[next].sent)
3029                                 goto nack_inv_unlck;
3030                         update_ack_queue(qp, next);
3031                 }
3032                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
3033                 release_rdma_sge_mr(e);
3034                 reth = &ohdr->u.rc.reth;
3035                 len = be32_to_cpu(reth->length);
3036                 if (len) {
3037                         u32 rkey = be32_to_cpu(reth->rkey);
3038                         u64 vaddr = get_ib_reth_vaddr(reth);
3039                         int ok;
3040
3041                         /* Check rkey & NAK */
3042                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr,
3043                                          rkey, IB_ACCESS_REMOTE_READ);
3044                         if (unlikely(!ok))
3045                                 goto nack_acc_unlck;
3046                         /*
3047                          * Update the next expected PSN.  We add 1 later
3048                          * below, so only add the remainder here.
3049                          */
3050                         qp->r_psn += rvt_div_mtu(qp, len - 1);
3051                 } else {
3052                         e->rdma_sge.mr = NULL;
3053                         e->rdma_sge.vaddr = NULL;
3054                         e->rdma_sge.length = 0;
3055                         e->rdma_sge.sge_length = 0;
3056                 }
3057                 e->opcode = opcode;
3058                 e->sent = 0;
3059                 e->psn = psn;
3060                 e->lpsn = qp->r_psn;
3061                 /*
3062                  * We need to increment the MSN here instead of when we
3063                  * finish sending the result since a duplicate request would
3064                  * increment it more than once.
3065                  */
3066                 qp->r_msn++;
3067                 qp->r_psn++;
3068                 qp->r_state = opcode;
3069                 qp->r_nak_state = 0;
3070                 qp->r_head_ack_queue = next;
3071                 qpriv->r_tid_alloc = qp->r_head_ack_queue;
3072
3073                 /* Schedule the send engine. */
3074                 qp->s_flags |= RVT_S_RESP_PENDING;
3075                 if (fecn)
3076                         qp->s_flags |= RVT_S_ECN;
3077                 hfi1_schedule_send(qp);
3078
3079                 spin_unlock_irqrestore(&qp->s_lock, flags);
3080                 return;
3081         }
3082
3083         case OP(COMPARE_SWAP):
3084         case OP(FETCH_ADD): {
3085                 struct ib_atomic_eth *ateth = &ohdr->u.atomic_eth;
3086                 u64 vaddr = get_ib_ateth_vaddr(ateth);
3087                 bool opfn = opcode == OP(COMPARE_SWAP) &&
3088                         vaddr == HFI1_VERBS_E_ATOMIC_VADDR;
3089                 struct rvt_ack_entry *e;
3090                 atomic64_t *maddr;
3091                 u64 sdata;
3092                 u32 rkey;
3093                 u8 next;
3094
3095                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC) &&
3096                              !opfn))
3097                         goto nack_inv;
3098                 next = qp->r_head_ack_queue + 1;
3099                 if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
3100                         next = 0;
3101                 spin_lock_irqsave(&qp->s_lock, flags);
3102                 if (unlikely(next == qp->s_acked_ack_queue)) {
3103                         if (!qp->s_ack_queue[next].sent)
3104                                 goto nack_inv_unlck;
3105                         update_ack_queue(qp, next);
3106                 }
3107                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
3108                 release_rdma_sge_mr(e);
3109                 /* Process OPFN special virtual address */
3110                 if (opfn) {
3111                         opfn_conn_response(qp, e, ateth);
3112                         goto ack;
3113                 }
3114                 if (unlikely(vaddr & (sizeof(u64) - 1)))
3115                         goto nack_inv_unlck;
3116                 rkey = be32_to_cpu(ateth->rkey);
3117                 /* Check rkey & NAK */
3118                 if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
3119                                           vaddr, rkey,
3120                                           IB_ACCESS_REMOTE_ATOMIC)))
3121                         goto nack_acc_unlck;
3122                 /* Perform atomic OP and save result. */
3123                 maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
3124                 sdata = get_ib_ateth_swap(ateth);
3125                 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
3126                         (u64)atomic64_add_return(sdata, maddr) - sdata :
3127                         (u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
3128                                       get_ib_ateth_compare(ateth),
3129                                       sdata);
3130                 rvt_put_mr(qp->r_sge.sge.mr);
3131                 qp->r_sge.num_sge = 0;
3132 ack:
3133                 e->opcode = opcode;
3134                 e->sent = 0;
3135                 e->psn = psn;
3136                 e->lpsn = psn;
3137                 qp->r_msn++;
3138                 qp->r_psn++;
3139                 qp->r_state = opcode;
3140                 qp->r_nak_state = 0;
3141                 qp->r_head_ack_queue = next;
3142                 qpriv->r_tid_alloc = qp->r_head_ack_queue;
3143
3144                 /* Schedule the send engine. */
3145                 qp->s_flags |= RVT_S_RESP_PENDING;
3146                 if (fecn)
3147                         qp->s_flags |= RVT_S_ECN;
3148                 hfi1_schedule_send(qp);
3149
3150                 spin_unlock_irqrestore(&qp->s_lock, flags);
3151                 return;
3152         }
3153
3154         default:
3155                 /* NAK unknown opcodes. */
3156                 goto nack_inv;
3157         }
3158         qp->r_psn++;
3159         qp->r_state = opcode;
3160         qp->r_ack_psn = psn;
3161         qp->r_nak_state = 0;
3162         /* Send an ACK if requested or required. */
3163         if (psn & IB_BTH_REQ_ACK || fecn) {
3164                 if (packet->numpkt == 0 || fecn ||
3165                     qp->r_adefered >= HFI1_PSN_CREDIT) {
3166                         rc_cancel_ack(qp);
3167                         goto send_ack;
3168                 }
3169                 qp->r_adefered++;
3170                 rc_defered_ack(rcd, qp);
3171         }
3172         return;
3173
3174 rnr_nak:
3175         qp->r_nak_state = qp->r_min_rnr_timer | IB_RNR_NAK;
3176         qp->r_ack_psn = qp->r_psn;
3177         /* Queue RNR NAK for later */
3178         rc_defered_ack(rcd, qp);
3179         return;
3180
3181 nack_op_err:
3182         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
3183         qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
3184         qp->r_ack_psn = qp->r_psn;
3185         /* Queue NAK for later */
3186         rc_defered_ack(rcd, qp);
3187         return;
3188
3189 nack_inv_unlck:
3190         spin_unlock_irqrestore(&qp->s_lock, flags);
3191 nack_inv:
3192         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
3193         qp->r_nak_state = IB_NAK_INVALID_REQUEST;
3194         qp->r_ack_psn = qp->r_psn;
3195         /* Queue NAK for later */
3196         rc_defered_ack(rcd, qp);
3197         return;
3198
3199 nack_acc_unlck:
3200         spin_unlock_irqrestore(&qp->s_lock, flags);
3201 nack_acc:
3202         rvt_rc_error(qp, IB_WC_LOC_PROT_ERR);
3203         qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
3204         qp->r_ack_psn = qp->r_psn;
3205 send_ack:
3206         hfi1_send_rc_ack(packet, fecn);
3207 }
3208
3209 void hfi1_rc_hdrerr(
3210         struct hfi1_ctxtdata *rcd,
3211         struct hfi1_packet *packet,
3212         struct rvt_qp *qp)
3213 {
3214         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
3215         int diff;
3216         u32 opcode;
3217         u32 psn;
3218
3219         if (hfi1_ruc_check_hdr(ibp, packet))
3220                 return;
3221
3222         psn = ib_bth_get_psn(packet->ohdr);
3223         opcode = ib_bth_get_opcode(packet->ohdr);
3224
3225         /* Only deal with RDMA Writes for now */
3226         if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {
3227                 diff = delta_psn(psn, qp->r_psn);
3228                 if (!qp->r_nak_state && diff >= 0) {
3229                         ibp->rvp.n_rc_seqnak++;
3230                         qp->r_nak_state = IB_NAK_PSN_ERROR;
3231                         /* Use the expected PSN. */
3232                         qp->r_ack_psn = qp->r_psn;
3233                         /*
3234                          * Wait to send the sequence
3235                          * NAK until all packets
3236                          * in the receive queue have
3237                          * been processed.
3238                          * Otherwise, we end up
3239                          * propagating congestion.
3240                          */
3241                         rc_defered_ack(rcd, qp);
3242                 } /* Out of sequence NAK */
3243         } /* QP Request NAKs */
3244 }