drivers/infiniband/sw/rxe/rxe_comp.c

   1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
   2 /*
   3  * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
   4  * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
   5  */
   6
   7 #include <linux/skbuff.h>
   8
   9 #include "rxe.h"
  10 #include "rxe_loc.h"
  11 #include "rxe_queue.h"
  12 #include "rxe_task.h"
  13
  14 enum comp_state {
  15         COMPST_GET_ACK,
  16         COMPST_GET_WQE,
  17         COMPST_COMP_WQE,
  18         COMPST_COMP_ACK,
  19         COMPST_CHECK_PSN,
  20         COMPST_CHECK_ACK,
  21         COMPST_READ,
  22         COMPST_ATOMIC,
  23         COMPST_WRITE_SEND,
  24         COMPST_UPDATE_COMP,
  25         COMPST_ERROR_RETRY,
  26         COMPST_RNR_RETRY,
  27         COMPST_ERROR,
  28         COMPST_EXIT, /* We have an issue, and we want to rerun the completer */
  29         COMPST_DONE, /* The completer finished successflly */
  30 };
  31
  32 static char *comp_state_name[] =  {
  33         [COMPST_GET_ACK]                = "GET ACK",
  34         [COMPST_GET_WQE]                = "GET WQE",
  35         [COMPST_COMP_WQE]               = "COMP WQE",
  36         [COMPST_COMP_ACK]               = "COMP ACK",
  37         [COMPST_CHECK_PSN]              = "CHECK PSN",
  38         [COMPST_CHECK_ACK]              = "CHECK ACK",
  39         [COMPST_READ]                   = "READ",
  40         [COMPST_ATOMIC]                 = "ATOMIC",
  41         [COMPST_WRITE_SEND]             = "WRITE/SEND",
  42         [COMPST_UPDATE_COMP]            = "UPDATE COMP",
  43         [COMPST_ERROR_RETRY]            = "ERROR RETRY",
  44         [COMPST_RNR_RETRY]              = "RNR RETRY",
  45         [COMPST_ERROR]                  = "ERROR",
  46         [COMPST_EXIT]                   = "EXIT",
  47         [COMPST_DONE]                   = "DONE",
  48 };
  49
  50 static unsigned long rnrnak_usec[32] = {
  51         [IB_RNR_TIMER_655_36] = 655360,
  52         [IB_RNR_TIMER_000_01] = 10,
  53         [IB_RNR_TIMER_000_02] = 20,
  54         [IB_RNR_TIMER_000_03] = 30,
  55         [IB_RNR_TIMER_000_04] = 40,
  56         [IB_RNR_TIMER_000_06] = 60,
  57         [IB_RNR_TIMER_000_08] = 80,
  58         [IB_RNR_TIMER_000_12] = 120,
  59         [IB_RNR_TIMER_000_16] = 160,
  60         [IB_RNR_TIMER_000_24] = 240,
  61         [IB_RNR_TIMER_000_32] = 320,
  62         [IB_RNR_TIMER_000_48] = 480,
  63         [IB_RNR_TIMER_000_64] = 640,
  64         [IB_RNR_TIMER_000_96] = 960,
  65         [IB_RNR_TIMER_001_28] = 1280,
  66         [IB_RNR_TIMER_001_92] = 1920,
  67         [IB_RNR_TIMER_002_56] = 2560,
  68         [IB_RNR_TIMER_003_84] = 3840,
  69         [IB_RNR_TIMER_005_12] = 5120,
  70         [IB_RNR_TIMER_007_68] = 7680,
  71         [IB_RNR_TIMER_010_24] = 10240,
  72         [IB_RNR_TIMER_015_36] = 15360,
  73         [IB_RNR_TIMER_020_48] = 20480,
  74         [IB_RNR_TIMER_030_72] = 30720,
  75         [IB_RNR_TIMER_040_96] = 40960,
  76         [IB_RNR_TIMER_061_44] = 61410,
  77         [IB_RNR_TIMER_081_92] = 81920,
  78         [IB_RNR_TIMER_122_88] = 122880,
  79         [IB_RNR_TIMER_163_84] = 163840,
  80         [IB_RNR_TIMER_245_76] = 245760,
  81         [IB_RNR_TIMER_327_68] = 327680,
  82         [IB_RNR_TIMER_491_52] = 491520,
  83 };
  84
  85 static inline unsigned long rnrnak_jiffies(u8 timeout)
  86 {
  87         return max_t(unsigned long,
  88                 usecs_to_jiffies(rnrnak_usec[timeout]), 1);
  89 }
  90
  91 static enum ib_wc_opcode wr_to_wc_opcode(enum ib_wr_opcode opcode)
  92 {
  93         switch (opcode) {
  94         case IB_WR_RDMA_WRITE:                  return IB_WC_RDMA_WRITE;
  95         case IB_WR_RDMA_WRITE_WITH_IMM:         return IB_WC_RDMA_WRITE;
  96         case IB_WR_SEND:                        return IB_WC_SEND;
  97         case IB_WR_SEND_WITH_IMM:               return IB_WC_SEND;
  98         case IB_WR_RDMA_READ:                   return IB_WC_RDMA_READ;
  99         case IB_WR_ATOMIC_CMP_AND_SWP:          return IB_WC_COMP_SWAP;
 100         case IB_WR_ATOMIC_FETCH_AND_ADD:        return IB_WC_FETCH_ADD;
 101         case IB_WR_LSO:                         return IB_WC_LSO;
 102         case IB_WR_SEND_WITH_INV:               return IB_WC_SEND;
 103         case IB_WR_RDMA_READ_WITH_INV:          return IB_WC_RDMA_READ;
 104         case IB_WR_LOCAL_INV:                   return IB_WC_LOCAL_INV;
 105         case IB_WR_REG_MR:                      return IB_WC_REG_MR;
 106         case IB_WR_BIND_MW:                     return IB_WC_BIND_MW;
 107         case IB_WR_ATOMIC_WRITE:                return IB_WC_ATOMIC_WRITE;
 108         case IB_WR_FLUSH:                       return IB_WC_FLUSH;
 109
 110         default:
 111                 return 0xff;
 112         }
 113 }
 114
 115 void retransmit_timer(struct timer_list *t)
 116 {
 117         struct rxe_qp *qp = from_timer(qp, t, retrans_timer);
 118         unsigned long flags;
 119
 120         rxe_dbg_qp(qp, "retransmit timer fired\n");
 121
 122         spin_lock_irqsave(&qp->state_lock, flags);
 123         if (qp->valid) {
 124                 qp->comp.timeout = 1;
 125                 rxe_sched_task(&qp->send_task);
 126         }
 127         spin_unlock_irqrestore(&qp->state_lock, flags);
 128 }
 129
 130 void rxe_comp_queue_pkt(struct rxe_qp *qp, struct sk_buff *skb)
 131 {
 132         rxe_counter_inc(SKB_TO_PKT(skb)->rxe, RXE_CNT_SENDER_SCHED);
 133         skb_queue_tail(&qp->resp_pkts, skb);
 134         rxe_sched_task(&qp->send_task);
 135 }
 136
 137 static inline enum comp_state get_wqe(struct rxe_qp *qp,
 138                                       struct rxe_pkt_info *pkt,
 139                                       struct rxe_send_wqe **wqe_p)
 140 {
 141         struct rxe_send_wqe *wqe;
 142
 143         /* we come here whether or not we found a response packet to see if
 144          * there are any posted WQEs
 145          */
 146         wqe = queue_head(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT);
 147         *wqe_p = wqe;
 148
 149         /* no WQE or requester has not started it yet */
 150         if (!wqe || wqe->state == wqe_state_posted)
 151                 return pkt ? COMPST_DONE : COMPST_EXIT;
 152
 153         /* WQE does not require an ack */
 154         if (wqe->state == wqe_state_done)
 155                 return COMPST_COMP_WQE;
 156
 157         /* WQE caused an error */
 158         if (wqe->state == wqe_state_error)
 159                 return COMPST_ERROR;
 160
 161         /* we have a WQE, if we also have an ack check its PSN */
 162         return pkt ? COMPST_CHECK_PSN : COMPST_EXIT;
 163 }
 164
 165 static inline void reset_retry_counters(struct rxe_qp *qp)
 166 {
 167         qp->comp.retry_cnt = qp->attr.retry_cnt;
 168         qp->comp.rnr_retry = qp->attr.rnr_retry;
 169         qp->comp.started_retry = 0;
 170 }
 171
 172 static inline enum comp_state check_psn(struct rxe_qp *qp,
 173                                         struct rxe_pkt_info *pkt,
 174                                         struct rxe_send_wqe *wqe)
 175 {
 176         s32 diff;
 177
 178         /* check to see if response is past the oldest WQE. if it is, complete
 179          * send/write or error read/atomic
 180          */
 181         diff = psn_compare(pkt->psn, wqe->last_psn);
 182         if (diff > 0) {
 183                 if (wqe->state == wqe_state_pending) {
 184                         if (wqe->mask & WR_ATOMIC_OR_READ_MASK)
 185                                 return COMPST_ERROR_RETRY;
 186
 187                         reset_retry_counters(qp);
 188                         return COMPST_COMP_WQE;
 189                 } else {
 190                         return COMPST_DONE;
 191                 }
 192         }
 193
 194         /* compare response packet to expected response */
 195         diff = psn_compare(pkt->psn, qp->comp.psn);
 196         if (diff < 0) {
 197                 /* response is most likely a retried packet if it matches an
 198                  * uncompleted WQE go complete it else ignore it
 199                  */
 200                 if (pkt->psn == wqe->last_psn)
 201                         return COMPST_COMP_ACK;
 202                 else if (pkt->opcode == IB_OPCODE_RC_ACKNOWLEDGE &&
 203                          (qp->comp.opcode == IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST ||
 204                           qp->comp.opcode == IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE))
 205                         return COMPST_CHECK_ACK;
 206                 else
 207                         return COMPST_DONE;
 208         } else if ((diff > 0) && (wqe->mask & WR_ATOMIC_OR_READ_MASK)) {
 209                 return COMPST_DONE;
 210         } else {
 211                 return COMPST_CHECK_ACK;
 212         }
 213 }
 214
 215 static inline enum comp_state check_ack(struct rxe_qp *qp,
 216                                         struct rxe_pkt_info *pkt,
 217                                         struct rxe_send_wqe *wqe)
 218 {
 219         unsigned int mask = pkt->mask;
 220         u8 syn;
 221         struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
 222
 223         /* Check the sequence only */
 224         switch (qp->comp.opcode) {
 225         case -1:
 226                 /* Will catch all *_ONLY cases. */
 227                 if (!(mask & RXE_START_MASK))
 228                         return COMPST_ERROR;
 229
 230                 break;
 231
 232         case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST:
 233         case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE:
 234                 /* Check NAK code to handle a remote error */
 235                 if (pkt->opcode == IB_OPCODE_RC_ACKNOWLEDGE)
 236                         break;
 237
 238                 if (pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE &&
 239                     pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST) {
 240                         /* read retries of partial data may restart from
 241                          * read response first or response only.
 242                          */
 243                         if ((pkt->psn == wqe->first_psn &&
 244                              pkt->opcode ==
 245                              IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) ||
 246                             (wqe->first_psn == wqe->last_psn &&
 247                              pkt->opcode ==
 248                              IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY))
 249                                 break;
 250
 251                         return COMPST_ERROR;
 252                 }
 253                 break;
 254         default:
 255                 WARN_ON_ONCE(1);
 256         }
 257
 258         /* Check operation validity. */
 259         switch (pkt->opcode) {
 260         case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST:
 261         case IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST:
 262         case IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY:
 263                 syn = aeth_syn(pkt);
 264
 265                 if ((syn & AETH_TYPE_MASK) != AETH_ACK)
 266                         return COMPST_ERROR;
 267
 268                 if (wqe->wr.opcode == IB_WR_ATOMIC_WRITE)
 269                         return COMPST_WRITE_SEND;
 270
 271                 fallthrough;
 272                 /* (IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE doesn't have an AETH)
 273                  */
 274         case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE:
 275                 if (wqe->wr.opcode != IB_WR_RDMA_READ &&
 276                     wqe->wr.opcode != IB_WR_RDMA_READ_WITH_INV &&
 277                     wqe->wr.opcode != IB_WR_FLUSH) {
 278                         wqe->status = IB_WC_FATAL_ERR;
 279                         return COMPST_ERROR;
 280                 }
 281                 reset_retry_counters(qp);
 282                 return COMPST_READ;
 283
 284         case IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE:
 285                 syn = aeth_syn(pkt);
 286
 287                 if ((syn & AETH_TYPE_MASK) != AETH_ACK)
 288                         return COMPST_ERROR;
 289
 290                 if (wqe->wr.opcode != IB_WR_ATOMIC_CMP_AND_SWP &&
 291                     wqe->wr.opcode != IB_WR_ATOMIC_FETCH_AND_ADD)
 292                         return COMPST_ERROR;
 293                 reset_retry_counters(qp);
 294                 return COMPST_ATOMIC;
 295
 296         case IB_OPCODE_RC_ACKNOWLEDGE:
 297                 syn = aeth_syn(pkt);
 298                 switch (syn & AETH_TYPE_MASK) {
 299                 case AETH_ACK:
 300                         reset_retry_counters(qp);
 301                         return COMPST_WRITE_SEND;
 302
 303                 case AETH_RNR_NAK:
 304                         rxe_counter_inc(rxe, RXE_CNT_RCV_RNR);
 305                         return COMPST_RNR_RETRY;
 306
 307                 case AETH_NAK:
 308                         switch (syn) {
 309                         case AETH_NAK_PSN_SEQ_ERROR:
 310                                 /* a nak implicitly acks all packets with psns
 311                                  * before
 312                                  */
 313                                 if (psn_compare(pkt->psn, qp->comp.psn) > 0) {
 314                                         rxe_counter_inc(rxe,
 315                                                         RXE_CNT_RCV_SEQ_ERR);
 316                                         qp->comp.psn = pkt->psn;
 317                                         if (qp->req.wait_psn) {
 318                                                 qp->req.wait_psn = 0;
 319                                                 qp->req.again = 1;
 320                                         }
 321                                 }
 322                                 return COMPST_ERROR_RETRY;
 323
 324                         case AETH_NAK_INVALID_REQ:
 325                                 wqe->status = IB_WC_REM_INV_REQ_ERR;
 326                                 return COMPST_ERROR;
 327
 328                         case AETH_NAK_REM_ACC_ERR:
 329                                 wqe->status = IB_WC_REM_ACCESS_ERR;
 330                                 return COMPST_ERROR;
 331
 332                         case AETH_NAK_REM_OP_ERR:
 333                                 wqe->status = IB_WC_REM_OP_ERR;
 334                                 return COMPST_ERROR;
 335
 336                         default:
 337                                 rxe_dbg_qp(qp, "unexpected nak %x\n", syn);
 338                                 wqe->status = IB_WC_REM_OP_ERR;
 339                                 return COMPST_ERROR;
 340                         }
 341
 342                 default:
 343                         return COMPST_ERROR;
 344                 }
 345                 break;
 346
 347         default:
 348                 rxe_dbg_qp(qp, "unexpected opcode\n");
 349         }
 350
 351         return COMPST_ERROR;
 352 }
 353
 354 static inline enum comp_state do_read(struct rxe_qp *qp,
 355                                       struct rxe_pkt_info *pkt,
 356                                       struct rxe_send_wqe *wqe)
 357 {
 358         int ret;
 359
 360         ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE,
 361                         &wqe->dma, payload_addr(pkt),
 362                         payload_size(pkt), RXE_TO_MR_OBJ);
 363         if (ret) {
 364                 wqe->status = IB_WC_LOC_PROT_ERR;
 365                 return COMPST_ERROR;
 366         }
 367
 368         if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK))
 369                 return COMPST_COMP_ACK;
 370
 371         return COMPST_UPDATE_COMP;
 372 }
 373
 374 static inline enum comp_state do_atomic(struct rxe_qp *qp,
 375                                         struct rxe_pkt_info *pkt,
 376                                         struct rxe_send_wqe *wqe)
 377 {
 378         int ret;
 379
 380         u64 atomic_orig = atmack_orig(pkt);
 381
 382         ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE,
 383                         &wqe->dma, &atomic_orig,
 384                         sizeof(u64), RXE_TO_MR_OBJ);
 385         if (ret) {
 386                 wqe->status = IB_WC_LOC_PROT_ERR;
 387                 return COMPST_ERROR;
 388         }
 389
 390         return COMPST_COMP_ACK;
 391 }
 392
 393 static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
 394                           struct rxe_cqe *cqe)
 395 {
 396         struct ib_wc *wc = &cqe->ibwc;
 397         struct ib_uverbs_wc *uwc = &cqe->uibwc;
 398
 399         memset(cqe, 0, sizeof(*cqe));
 400
 401         if (!qp->is_user) {
 402                 wc->wr_id = wqe->wr.wr_id;
 403                 wc->status = wqe->status;
 404                 wc->qp = &qp->ibqp;
 405         } else {
 406                 uwc->wr_id = wqe->wr.wr_id;
 407                 uwc->status = wqe->status;
 408                 uwc->qp_num = qp->ibqp.qp_num;
 409         }
 410
 411         if (wqe->status == IB_WC_SUCCESS) {
 412                 if (!qp->is_user) {
 413                         wc->opcode = wr_to_wc_opcode(wqe->wr.opcode);
 414                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM ||
 415                             wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
 416                                 wc->wc_flags = IB_WC_WITH_IMM;
 417                         wc->byte_len = wqe->dma.length;
 418                 } else {
 419                         uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode);
 420                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM ||
 421                             wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
 422                                 uwc->wc_flags = IB_WC_WITH_IMM;
 423                         uwc->byte_len = wqe->dma.length;
 424                 }
 425         } else {
 426                 if (wqe->status != IB_WC_WR_FLUSH_ERR)
 427                         rxe_err_qp(qp, "non-flush error status = %d\n",
 428                                 wqe->status);
 429         }
 430 }
 431
 432 /*
 433  * IBA Spec. Section 10.7.3.1 SIGNALED COMPLETIONS
 434  * ---------8<---------8<-------------
 435  * ...Note that if a completion error occurs, a Work Completion
 436  * will always be generated, even if the signaling
 437  * indicator requests an Unsignaled Completion.
 438  * ---------8<---------8<-------------
 439  */
 440 static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe)
 441 {
 442         struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
 443         struct rxe_cqe cqe;
 444         bool post;
 445
 446         /* do we need to post a completion */
 447         post = ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) ||
 448                         (wqe->wr.send_flags & IB_SEND_SIGNALED) ||
 449                         wqe->status != IB_WC_SUCCESS);
 450
 451         if (post)
 452                 make_send_cqe(qp, wqe, &cqe);
 453
 454         queue_advance_consumer(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT);
 455
 456         if (post)
 457                 rxe_cq_post(qp->scq, &cqe, 0);
 458
 459         if (wqe->wr.opcode == IB_WR_SEND ||
 460             wqe->wr.opcode == IB_WR_SEND_WITH_IMM ||
 461             wqe->wr.opcode == IB_WR_SEND_WITH_INV)
 462                 rxe_counter_inc(rxe, RXE_CNT_RDMA_SEND);
 463
 464         /*
 465          * we completed something so let req run again
 466          * if it is trying to fence
 467          */
 468         if (qp->req.wait_fence) {
 469                 qp->req.wait_fence = 0;
 470                 qp->req.again = 1;
 471         }
 472 }
 473
 474 static void comp_check_sq_drain_done(struct rxe_qp *qp)
 475 {
 476         unsigned long flags;
 477
 478         spin_lock_irqsave(&qp->state_lock, flags);
 479         if (unlikely(qp_state(qp) == IB_QPS_SQD)) {
 480                 if (qp->attr.sq_draining && qp->comp.psn == qp->req.psn) {
 481                         qp->attr.sq_draining = 0;
 482                         spin_unlock_irqrestore(&qp->state_lock, flags);
 483
 484                         if (qp->ibqp.event_handler) {
 485                                 struct ib_event ev;
 486
 487                                 ev.device = qp->ibqp.device;
 488                                 ev.element.qp = &qp->ibqp;
 489                                 ev.event = IB_EVENT_SQ_DRAINED;
 490                                 qp->ibqp.event_handler(&ev,
 491                                         qp->ibqp.qp_context);
 492                         }
 493                         return;
 494                 }
 495         }
 496         spin_unlock_irqrestore(&qp->state_lock, flags);
 497 }
 498
 499 static inline enum comp_state complete_ack(struct rxe_qp *qp,
 500                                            struct rxe_pkt_info *pkt,
 501                                            struct rxe_send_wqe *wqe)
 502 {
 503         if (wqe->has_rd_atomic) {
 504                 wqe->has_rd_atomic = 0;
 505                 atomic_inc(&qp->req.rd_atomic);
 506                 if (qp->req.need_rd_atomic) {
 507                         qp->comp.timeout_retry = 0;
 508                         qp->req.need_rd_atomic = 0;
 509                         qp->req.again = 1;
 510                 }
 511         }
 512
 513         comp_check_sq_drain_done(qp);
 514
 515         do_complete(qp, wqe);
 516
 517         if (psn_compare(pkt->psn, qp->comp.psn) >= 0)
 518                 return COMPST_UPDATE_COMP;
 519         else
 520                 return COMPST_DONE;
 521 }
 522
 523 static inline enum comp_state complete_wqe(struct rxe_qp *qp,
 524                                            struct rxe_pkt_info *pkt,
 525                                            struct rxe_send_wqe *wqe)
 526 {
 527         if (pkt && wqe->state == wqe_state_pending) {
 528                 if (psn_compare(wqe->last_psn, qp->comp.psn) >= 0) {
 529                         qp->comp.psn = (wqe->last_psn + 1) & BTH_PSN_MASK;
 530                         qp->comp.opcode = -1;
 531                 }
 532
 533                 if (qp->req.wait_psn) {
 534                         qp->req.wait_psn = 0;
 535                         qp->req.again = 1;
 536                 }
 537         }
 538
 539         do_complete(qp, wqe);
 540
 541         return COMPST_GET_WQE;
 542 }
 543
 544 /* drain incoming response packet queue */
 545 static void drain_resp_pkts(struct rxe_qp *qp)
 546 {
 547         struct sk_buff *skb;
 548
 549         while ((skb = skb_dequeue(&qp->resp_pkts))) {
 550                 rxe_put(qp);
 551                 kfree_skb(skb);
 552                 ib_device_put(qp->ibqp.device);
 553         }
 554 }
 555
 556 /* complete send wqe with flush error */
 557 static int flush_send_wqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe)
 558 {
 559         struct rxe_cqe cqe = {};
 560         struct ib_wc *wc = &cqe.ibwc;
 561         struct ib_uverbs_wc *uwc = &cqe.uibwc;
 562         int err;
 563
 564         if (qp->is_user) {
 565                 uwc->wr_id = wqe->wr.wr_id;
 566                 uwc->status = IB_WC_WR_FLUSH_ERR;
 567                 uwc->qp_num = qp->ibqp.qp_num;
 568         } else {
 569                 wc->wr_id = wqe->wr.wr_id;
 570                 wc->status = IB_WC_WR_FLUSH_ERR;
 571                 wc->qp = &qp->ibqp;
 572         }
 573
 574         err = rxe_cq_post(qp->scq, &cqe, 0);
 575         if (err)
 576                 rxe_dbg_cq(qp->scq, "post cq failed, err = %d\n", err);
 577
 578         return err;
 579 }
 580
 581 /* drain and optionally complete the send queue
 582  * if unable to complete a wqe, i.e. cq is full, stop
 583  * completing and flush the remaining wqes
 584  */
 585 static void flush_send_queue(struct rxe_qp *qp, bool notify)
 586 {
 587         struct rxe_send_wqe *wqe;
 588         struct rxe_queue *q = qp->sq.queue;
 589         int err;
 590
 591         /* send queue never got created. nothing to do. */
 592         if (!qp->sq.queue)
 593                 return;
 594
 595         while ((wqe = queue_head(q, q->type))) {
 596                 if (notify) {
 597                         err = flush_send_wqe(qp, wqe);
 598                         if (err)
 599                                 notify = 0;
 600                 }
 601                 queue_advance_consumer(q, q->type);
 602         }
 603 }
 604
 605 static void free_pkt(struct rxe_pkt_info *pkt)
 606 {
 607         struct sk_buff *skb = PKT_TO_SKB(pkt);
 608         struct rxe_qp *qp = pkt->qp;
 609         struct ib_device *dev = qp->ibqp.device;
 610
 611         kfree_skb(skb);
 612         rxe_put(qp);
 613         ib_device_put(dev);
 614 }
 615
 616 /* reset the retry timer if
 617  * - QP is type RC
 618  * - there is a packet sent by the requester that
 619  *   might be acked (we still might get spurious
 620  *   timeouts but try to keep them as few as possible)
 621  * - the timeout parameter is set
 622  * - the QP is alive
 623  */
 624 static void reset_retry_timer(struct rxe_qp *qp)
 625 {
 626         unsigned long flags;
 627
 628         if (qp_type(qp) == IB_QPT_RC && qp->qp_timeout_jiffies) {
 629                 spin_lock_irqsave(&qp->state_lock, flags);
 630                 if (qp_state(qp) >= IB_QPS_RTS &&
 631                     psn_compare(qp->req.psn, qp->comp.psn) > 0)
 632                         mod_timer(&qp->retrans_timer,
 633                                   jiffies + qp->qp_timeout_jiffies);
 634                 spin_unlock_irqrestore(&qp->state_lock, flags);
 635         }
 636 }
 637
 638 int rxe_completer(struct rxe_qp *qp)
 639 {
 640         struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
 641         struct rxe_send_wqe *wqe = NULL;
 642         struct sk_buff *skb = NULL;
 643         struct rxe_pkt_info *pkt = NULL;
 644         enum comp_state state;
 645         int ret;
 646         unsigned long flags;
 647
 648         qp->req.again = 0;
 649
 650         spin_lock_irqsave(&qp->state_lock, flags);
 651         if (!qp->valid || qp_state(qp) == IB_QPS_ERR ||
 652                           qp_state(qp) == IB_QPS_RESET) {
 653                 bool notify = qp->valid && (qp_state(qp) == IB_QPS_ERR);
 654
 655                 drain_resp_pkts(qp);
 656                 flush_send_queue(qp, notify);
 657                 spin_unlock_irqrestore(&qp->state_lock, flags);
 658                 goto exit;
 659         }
 660         spin_unlock_irqrestore(&qp->state_lock, flags);
 661
 662         if (qp->comp.timeout) {
 663                 qp->comp.timeout_retry = 1;
 664                 qp->comp.timeout = 0;
 665         } else {
 666                 qp->comp.timeout_retry = 0;
 667         }
 668
 669         if (qp->req.need_retry)
 670                 goto exit;
 671
 672         state = COMPST_GET_ACK;
 673
 674         while (1) {
 675                 rxe_dbg_qp(qp, "state = %s\n", comp_state_name[state]);
 676                 switch (state) {
 677                 case COMPST_GET_ACK:
 678                         skb = skb_dequeue(&qp->resp_pkts);
 679                         if (skb) {
 680                                 pkt = SKB_TO_PKT(skb);
 681                                 qp->comp.timeout_retry = 0;
 682                         }
 683                         state = COMPST_GET_WQE;
 684                         break;
 685
 686                 case COMPST_GET_WQE:
 687                         state = get_wqe(qp, pkt, &wqe);
 688                         break;
 689
 690                 case COMPST_CHECK_PSN:
 691                         state = check_psn(qp, pkt, wqe);
 692                         break;
 693
 694                 case COMPST_CHECK_ACK:
 695                         state = check_ack(qp, pkt, wqe);
 696                         break;
 697
 698                 case COMPST_READ:
 699                         state = do_read(qp, pkt, wqe);
 700                         break;
 701
 702                 case COMPST_ATOMIC:
 703                         state = do_atomic(qp, pkt, wqe);
 704                         break;
 705
 706                 case COMPST_WRITE_SEND:
 707                         if (wqe->state == wqe_state_pending &&
 708                             wqe->last_psn == pkt->psn)
 709                                 state = COMPST_COMP_ACK;
 710                         else
 711                                 state = COMPST_UPDATE_COMP;
 712                         break;
 713
 714                 case COMPST_COMP_ACK:
 715                         state = complete_ack(qp, pkt, wqe);
 716                         break;
 717
 718                 case COMPST_COMP_WQE:
 719                         state = complete_wqe(qp, pkt, wqe);
 720                         break;
 721
 722                 case COMPST_UPDATE_COMP:
 723                         if (pkt->mask & RXE_END_MASK)
 724                                 qp->comp.opcode = -1;
 725                         else
 726                                 qp->comp.opcode = pkt->opcode;
 727
 728                         if (psn_compare(pkt->psn, qp->comp.psn) >= 0)
 729                                 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
 730
 731                         if (qp->req.wait_psn) {
 732                                 qp->req.wait_psn = 0;
 733                                 qp->req.again = 1;
 734                         }
 735
 736                         state = COMPST_DONE;
 737                         break;
 738
 739                 case COMPST_DONE:
 740                         goto done;
 741
 742                 case COMPST_EXIT:
 743                         if (qp->comp.timeout_retry && wqe) {
 744                                 state = COMPST_ERROR_RETRY;
 745                                 break;
 746                         }
 747
 748                         reset_retry_timer(qp);
 749                         goto exit;
 750
 751                 case COMPST_ERROR_RETRY:
 752                         /* we come here if the retry timer fired and we did
 753                          * not receive a response packet. try to retry the send
 754                          * queue if that makes sense and the limits have not
 755                          * been exceeded. remember that some timeouts are
 756                          * spurious since we do not reset the timer but kick
 757                          * it down the road or let it expire
 758                          */
 759
 760                         /* there is nothing to retry in this case */
 761                         if (!wqe || (wqe->state == wqe_state_posted))
 762                                 goto exit;
 763
 764                         /* if we've started a retry, don't start another
 765                          * retry sequence, unless this is a timeout.
 766                          */
 767                         if (qp->comp.started_retry &&
 768                             !qp->comp.timeout_retry)
 769                                 goto done;
 770
 771                         if (qp->comp.retry_cnt > 0) {
 772                                 if (qp->comp.retry_cnt != 7)
 773                                         qp->comp.retry_cnt--;
 774
 775                                 /* no point in retrying if we have already
 776                                  * seen the last ack that the requester could
 777                                  * have caused
 778                                  */
 779                                 if (psn_compare(qp->req.psn,
 780                                                 qp->comp.psn) > 0) {
 781                                         /* tell the requester to retry the
 782                                          * send queue next time around
 783                                          */
 784                                         rxe_counter_inc(rxe,
 785                                                         RXE_CNT_COMP_RETRY);
 786                                         qp->req.need_retry = 1;
 787                                         qp->comp.started_retry = 1;
 788                                         qp->req.again = 1;
 789                                 }
 790                                 goto done;
 791
 792                         } else {
 793                                 rxe_counter_inc(rxe, RXE_CNT_RETRY_EXCEEDED);
 794                                 wqe->status = IB_WC_RETRY_EXC_ERR;
 795                                 state = COMPST_ERROR;
 796                         }
 797                         break;
 798
 799                 case COMPST_RNR_RETRY:
 800                         /* we come here if we received an RNR NAK */
 801                         if (qp->comp.rnr_retry > 0) {
 802                                 if (qp->comp.rnr_retry != 7)
 803                                         qp->comp.rnr_retry--;
 804
 805                                 /* don't start a retry flow until the
 806                                  * rnr timer has fired
 807                                  */
 808                                 qp->req.wait_for_rnr_timer = 1;
 809                                 rxe_dbg_qp(qp, "set rnr nak timer\n");
 810                                 // TODO who protects from destroy_qp??
 811                                 mod_timer(&qp->rnr_nak_timer,
 812                                           jiffies + rnrnak_jiffies(aeth_syn(pkt)
 813                                                 & ~AETH_TYPE_MASK));
 814                                 goto exit;
 815                         } else {
 816                                 rxe_counter_inc(rxe,
 817                                                 RXE_CNT_RNR_RETRY_EXCEEDED);
 818                                 wqe->status = IB_WC_RNR_RETRY_EXC_ERR;
 819                                 state = COMPST_ERROR;
 820                         }
 821                         break;
 822
 823                 case COMPST_ERROR:
 824                         WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS);
 825                         do_complete(qp, wqe);
 826                         rxe_qp_error(qp);
 827                         goto exit;
 828                 }
 829         }
 830
 831         /* A non-zero return value will cause rxe_do_task to
 832          * exit its loop and end the work item. A zero return
 833          * will continue looping and return to rxe_completer
 834          */
 835 done:
 836         ret = 0;
 837         goto out;
 838 exit:
 839         ret = (qp->req.again) ? 0 : -EAGAIN;
 840 out:
 841         qp->req.again = 0;
 842         if (pkt)
 843                 free_pkt(pkt);
 844         return ret;
 845 }