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