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; 107 108 default: 109 return 0xff; 110 } 111 } 112 113 void retransmit_timer(struct timer_list *t) 114 { 115 struct rxe_qp *qp = from_timer(qp, t, retrans_timer); 116 117 pr_debug("%s: fired for qp#%d\n", __func__, qp->elem.index); 118 119 if (qp->valid) { 120 qp->comp.timeout = 1; 121 rxe_run_task(&qp->comp.task, 1); 122 } 123 } 124 125 void rxe_comp_queue_pkt(struct rxe_qp *qp, struct sk_buff *skb) 126 { 127 int must_sched; 128 129 skb_queue_tail(&qp->resp_pkts, skb); 130 131 must_sched = skb_queue_len(&qp->resp_pkts) > 1; 132 if (must_sched != 0) 133 rxe_counter_inc(SKB_TO_PKT(skb)->rxe, RXE_CNT_COMPLETER_SCHED); 134 135 rxe_run_task(&qp->comp.task, must_sched); 136 } 137 138 static inline enum comp_state get_wqe(struct rxe_qp *qp, 139 struct rxe_pkt_info *pkt, 140 struct rxe_send_wqe **wqe_p) 141 { 142 struct rxe_send_wqe *wqe; 143 144 /* we come here whether or not we found a response packet to see if 145 * there are any posted WQEs 146 */ 147 wqe = queue_head(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT); 148 *wqe_p = wqe; 149 150 /* no WQE or requester has not started it yet */ 151 if (!wqe || wqe->state == wqe_state_posted) 152 return pkt ? COMPST_DONE : COMPST_EXIT; 153 154 /* WQE does not require an ack */ 155 if (wqe->state == wqe_state_done) 156 return COMPST_COMP_WQE; 157 158 /* WQE caused an error */ 159 if (wqe->state == wqe_state_error) 160 return COMPST_ERROR; 161 162 /* we have a WQE, if we also have an ack check its PSN */ 163 return pkt ? COMPST_CHECK_PSN : COMPST_EXIT; 164 } 165 166 static inline void reset_retry_counters(struct rxe_qp *qp) 167 { 168 qp->comp.retry_cnt = qp->attr.retry_cnt; 169 qp->comp.rnr_retry = qp->attr.rnr_retry; 170 qp->comp.started_retry = 0; 171 } 172 173 static inline enum comp_state check_psn(struct rxe_qp *qp, 174 struct rxe_pkt_info *pkt, 175 struct rxe_send_wqe *wqe) 176 { 177 s32 diff; 178 179 /* check to see if response is past the oldest WQE. if it is, complete 180 * send/write or error read/atomic 181 */ 182 diff = psn_compare(pkt->psn, wqe->last_psn); 183 if (diff > 0) { 184 if (wqe->state == wqe_state_pending) { 185 if (wqe->mask & WR_ATOMIC_OR_READ_MASK) 186 return COMPST_ERROR_RETRY; 187 188 reset_retry_counters(qp); 189 return COMPST_COMP_WQE; 190 } else { 191 return COMPST_DONE; 192 } 193 } 194 195 /* compare response packet to expected response */ 196 diff = psn_compare(pkt->psn, qp->comp.psn); 197 if (diff < 0) { 198 /* response is most likely a retried packet if it matches an 199 * uncompleted WQE go complete it else ignore it 200 */ 201 if (pkt->psn == wqe->last_psn) 202 return COMPST_COMP_ACK; 203 else 204 return COMPST_DONE; 205 } else if ((diff > 0) && (wqe->mask & WR_ATOMIC_OR_READ_MASK)) { 206 return COMPST_DONE; 207 } else { 208 return COMPST_CHECK_ACK; 209 } 210 } 211 212 static inline enum comp_state check_ack(struct rxe_qp *qp, 213 struct rxe_pkt_info *pkt, 214 struct rxe_send_wqe *wqe) 215 { 216 unsigned int mask = pkt->mask; 217 u8 syn; 218 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 219 220 /* Check the sequence only */ 221 switch (qp->comp.opcode) { 222 case -1: 223 /* Will catch all *_ONLY cases. */ 224 if (!(mask & RXE_START_MASK)) 225 return COMPST_ERROR; 226 227 break; 228 229 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 230 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 231 if (pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE && 232 pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST) { 233 /* read retries of partial data may restart from 234 * read response first or response only. 235 */ 236 if ((pkt->psn == wqe->first_psn && 237 pkt->opcode == 238 IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) || 239 (wqe->first_psn == wqe->last_psn && 240 pkt->opcode == 241 IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY)) 242 break; 243 244 return COMPST_ERROR; 245 } 246 break; 247 default: 248 WARN_ON_ONCE(1); 249 } 250 251 /* Check operation validity. */ 252 switch (pkt->opcode) { 253 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 254 case IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST: 255 case IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY: 256 syn = aeth_syn(pkt); 257 258 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 259 return COMPST_ERROR; 260 261 fallthrough; 262 /* (IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE doesn't have an AETH) 263 */ 264 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 265 if (wqe->wr.opcode != IB_WR_RDMA_READ && 266 wqe->wr.opcode != IB_WR_RDMA_READ_WITH_INV) { 267 wqe->status = IB_WC_FATAL_ERR; 268 return COMPST_ERROR; 269 } 270 reset_retry_counters(qp); 271 return COMPST_READ; 272 273 case IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE: 274 syn = aeth_syn(pkt); 275 276 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 277 return COMPST_ERROR; 278 279 if (wqe->wr.opcode != IB_WR_ATOMIC_CMP_AND_SWP && 280 wqe->wr.opcode != IB_WR_ATOMIC_FETCH_AND_ADD) 281 return COMPST_ERROR; 282 reset_retry_counters(qp); 283 return COMPST_ATOMIC; 284 285 case IB_OPCODE_RC_ACKNOWLEDGE: 286 syn = aeth_syn(pkt); 287 switch (syn & AETH_TYPE_MASK) { 288 case AETH_ACK: 289 reset_retry_counters(qp); 290 return COMPST_WRITE_SEND; 291 292 case AETH_RNR_NAK: 293 rxe_counter_inc(rxe, RXE_CNT_RCV_RNR); 294 return COMPST_RNR_RETRY; 295 296 case AETH_NAK: 297 switch (syn) { 298 case AETH_NAK_PSN_SEQ_ERROR: 299 /* a nak implicitly acks all packets with psns 300 * before 301 */ 302 if (psn_compare(pkt->psn, qp->comp.psn) > 0) { 303 rxe_counter_inc(rxe, 304 RXE_CNT_RCV_SEQ_ERR); 305 qp->comp.psn = pkt->psn; 306 if (qp->req.wait_psn) { 307 qp->req.wait_psn = 0; 308 rxe_run_task(&qp->req.task, 0); 309 } 310 } 311 return COMPST_ERROR_RETRY; 312 313 case AETH_NAK_INVALID_REQ: 314 wqe->status = IB_WC_REM_INV_REQ_ERR; 315 return COMPST_ERROR; 316 317 case AETH_NAK_REM_ACC_ERR: 318 wqe->status = IB_WC_REM_ACCESS_ERR; 319 return COMPST_ERROR; 320 321 case AETH_NAK_REM_OP_ERR: 322 wqe->status = IB_WC_REM_OP_ERR; 323 return COMPST_ERROR; 324 325 default: 326 pr_warn("unexpected nak %x\n", syn); 327 wqe->status = IB_WC_REM_OP_ERR; 328 return COMPST_ERROR; 329 } 330 331 default: 332 return COMPST_ERROR; 333 } 334 break; 335 336 default: 337 pr_warn("unexpected opcode\n"); 338 } 339 340 return COMPST_ERROR; 341 } 342 343 static inline enum comp_state do_read(struct rxe_qp *qp, 344 struct rxe_pkt_info *pkt, 345 struct rxe_send_wqe *wqe) 346 { 347 int ret; 348 349 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, 350 &wqe->dma, payload_addr(pkt), 351 payload_size(pkt), RXE_TO_MR_OBJ); 352 if (ret) { 353 wqe->status = IB_WC_LOC_PROT_ERR; 354 return COMPST_ERROR; 355 } 356 357 if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK)) 358 return COMPST_COMP_ACK; 359 360 return COMPST_UPDATE_COMP; 361 } 362 363 static inline enum comp_state do_atomic(struct rxe_qp *qp, 364 struct rxe_pkt_info *pkt, 365 struct rxe_send_wqe *wqe) 366 { 367 int ret; 368 369 u64 atomic_orig = atmack_orig(pkt); 370 371 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, 372 &wqe->dma, &atomic_orig, 373 sizeof(u64), RXE_TO_MR_OBJ); 374 if (ret) { 375 wqe->status = IB_WC_LOC_PROT_ERR; 376 return COMPST_ERROR; 377 } 378 379 return COMPST_COMP_ACK; 380 } 381 382 static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe, 383 struct rxe_cqe *cqe) 384 { 385 struct ib_wc *wc = &cqe->ibwc; 386 struct ib_uverbs_wc *uwc = &cqe->uibwc; 387 388 memset(cqe, 0, sizeof(*cqe)); 389 390 if (!qp->is_user) { 391 wc->wr_id = wqe->wr.wr_id; 392 wc->status = wqe->status; 393 wc->qp = &qp->ibqp; 394 } else { 395 uwc->wr_id = wqe->wr.wr_id; 396 uwc->status = wqe->status; 397 uwc->qp_num = qp->ibqp.qp_num; 398 } 399 400 if (wqe->status == IB_WC_SUCCESS) { 401 if (!qp->is_user) { 402 wc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 403 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 404 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 405 wc->wc_flags = IB_WC_WITH_IMM; 406 wc->byte_len = wqe->dma.length; 407 } else { 408 uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 409 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 410 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 411 uwc->wc_flags = IB_WC_WITH_IMM; 412 uwc->byte_len = wqe->dma.length; 413 } 414 } 415 } 416 417 /* 418 * IBA Spec. Section 10.7.3.1 SIGNALED COMPLETIONS 419 * ---------8<---------8<------------- 420 * ...Note that if a completion error occurs, a Work Completion 421 * will always be generated, even if the signaling 422 * indicator requests an Unsignaled Completion. 423 * ---------8<---------8<------------- 424 */ 425 static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe) 426 { 427 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 428 struct rxe_cqe cqe; 429 bool post; 430 431 /* do we need to post a completion */ 432 post = ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) || 433 (wqe->wr.send_flags & IB_SEND_SIGNALED) || 434 wqe->status != IB_WC_SUCCESS); 435 436 if (post) 437 make_send_cqe(qp, wqe, &cqe); 438 439 queue_advance_consumer(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT); 440 441 if (post) 442 rxe_cq_post(qp->scq, &cqe, 0); 443 444 if (wqe->wr.opcode == IB_WR_SEND || 445 wqe->wr.opcode == IB_WR_SEND_WITH_IMM || 446 wqe->wr.opcode == IB_WR_SEND_WITH_INV) 447 rxe_counter_inc(rxe, RXE_CNT_RDMA_SEND); 448 449 /* 450 * we completed something so let req run again 451 * if it is trying to fence 452 */ 453 if (qp->req.wait_fence) { 454 qp->req.wait_fence = 0; 455 rxe_run_task(&qp->req.task, 0); 456 } 457 } 458 459 static inline enum comp_state complete_ack(struct rxe_qp *qp, 460 struct rxe_pkt_info *pkt, 461 struct rxe_send_wqe *wqe) 462 { 463 if (wqe->has_rd_atomic) { 464 wqe->has_rd_atomic = 0; 465 atomic_inc(&qp->req.rd_atomic); 466 if (qp->req.need_rd_atomic) { 467 qp->comp.timeout_retry = 0; 468 qp->req.need_rd_atomic = 0; 469 rxe_run_task(&qp->req.task, 0); 470 } 471 } 472 473 if (unlikely(qp->req.state == QP_STATE_DRAIN)) { 474 /* state_lock used by requester & completer */ 475 spin_lock_bh(&qp->state_lock); 476 if ((qp->req.state == QP_STATE_DRAIN) && 477 (qp->comp.psn == qp->req.psn)) { 478 qp->req.state = QP_STATE_DRAINED; 479 spin_unlock_bh(&qp->state_lock); 480 481 if (qp->ibqp.event_handler) { 482 struct ib_event ev; 483 484 ev.device = qp->ibqp.device; 485 ev.element.qp = &qp->ibqp; 486 ev.event = IB_EVENT_SQ_DRAINED; 487 qp->ibqp.event_handler(&ev, 488 qp->ibqp.qp_context); 489 } 490 } else { 491 spin_unlock_bh(&qp->state_lock); 492 } 493 } 494 495 do_complete(qp, wqe); 496 497 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 498 return COMPST_UPDATE_COMP; 499 else 500 return COMPST_DONE; 501 } 502 503 static inline enum comp_state complete_wqe(struct rxe_qp *qp, 504 struct rxe_pkt_info *pkt, 505 struct rxe_send_wqe *wqe) 506 { 507 if (pkt && wqe->state == wqe_state_pending) { 508 if (psn_compare(wqe->last_psn, qp->comp.psn) >= 0) { 509 qp->comp.psn = (wqe->last_psn + 1) & BTH_PSN_MASK; 510 qp->comp.opcode = -1; 511 } 512 513 if (qp->req.wait_psn) { 514 qp->req.wait_psn = 0; 515 rxe_run_task(&qp->req.task, 1); 516 } 517 } 518 519 do_complete(qp, wqe); 520 521 return COMPST_GET_WQE; 522 } 523 524 static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify) 525 { 526 struct sk_buff *skb; 527 struct rxe_send_wqe *wqe; 528 struct rxe_queue *q = qp->sq.queue; 529 530 while ((skb = skb_dequeue(&qp->resp_pkts))) { 531 rxe_put(qp); 532 kfree_skb(skb); 533 ib_device_put(qp->ibqp.device); 534 } 535 536 while ((wqe = queue_head(q, q->type))) { 537 if (notify) { 538 wqe->status = IB_WC_WR_FLUSH_ERR; 539 do_complete(qp, wqe); 540 } else { 541 queue_advance_consumer(q, q->type); 542 } 543 } 544 } 545 546 static void free_pkt(struct rxe_pkt_info *pkt) 547 { 548 struct sk_buff *skb = PKT_TO_SKB(pkt); 549 struct rxe_qp *qp = pkt->qp; 550 struct ib_device *dev = qp->ibqp.device; 551 552 kfree_skb(skb); 553 rxe_put(qp); 554 ib_device_put(dev); 555 } 556 557 int rxe_completer(void *arg) 558 { 559 struct rxe_qp *qp = (struct rxe_qp *)arg; 560 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 561 struct rxe_send_wqe *wqe = NULL; 562 struct sk_buff *skb = NULL; 563 struct rxe_pkt_info *pkt = NULL; 564 enum comp_state state; 565 int ret; 566 567 if (!rxe_get(qp)) 568 return -EAGAIN; 569 570 if (!qp->valid || qp->comp.state == QP_STATE_ERROR || 571 qp->comp.state == QP_STATE_RESET) { 572 rxe_drain_resp_pkts(qp, qp->valid && 573 qp->comp.state == QP_STATE_ERROR); 574 goto exit; 575 } 576 577 if (qp->comp.timeout) { 578 qp->comp.timeout_retry = 1; 579 qp->comp.timeout = 0; 580 } else { 581 qp->comp.timeout_retry = 0; 582 } 583 584 if (qp->req.need_retry) 585 goto exit; 586 587 state = COMPST_GET_ACK; 588 589 while (1) { 590 pr_debug("qp#%d state = %s\n", qp_num(qp), 591 comp_state_name[state]); 592 switch (state) { 593 case COMPST_GET_ACK: 594 skb = skb_dequeue(&qp->resp_pkts); 595 if (skb) { 596 pkt = SKB_TO_PKT(skb); 597 qp->comp.timeout_retry = 0; 598 } 599 state = COMPST_GET_WQE; 600 break; 601 602 case COMPST_GET_WQE: 603 state = get_wqe(qp, pkt, &wqe); 604 break; 605 606 case COMPST_CHECK_PSN: 607 state = check_psn(qp, pkt, wqe); 608 break; 609 610 case COMPST_CHECK_ACK: 611 state = check_ack(qp, pkt, wqe); 612 break; 613 614 case COMPST_READ: 615 state = do_read(qp, pkt, wqe); 616 break; 617 618 case COMPST_ATOMIC: 619 state = do_atomic(qp, pkt, wqe); 620 break; 621 622 case COMPST_WRITE_SEND: 623 if (wqe->state == wqe_state_pending && 624 wqe->last_psn == pkt->psn) 625 state = COMPST_COMP_ACK; 626 else 627 state = COMPST_UPDATE_COMP; 628 break; 629 630 case COMPST_COMP_ACK: 631 state = complete_ack(qp, pkt, wqe); 632 break; 633 634 case COMPST_COMP_WQE: 635 state = complete_wqe(qp, pkt, wqe); 636 break; 637 638 case COMPST_UPDATE_COMP: 639 if (pkt->mask & RXE_END_MASK) 640 qp->comp.opcode = -1; 641 else 642 qp->comp.opcode = pkt->opcode; 643 644 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 645 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; 646 647 if (qp->req.wait_psn) { 648 qp->req.wait_psn = 0; 649 rxe_run_task(&qp->req.task, 1); 650 } 651 652 state = COMPST_DONE; 653 break; 654 655 case COMPST_DONE: 656 goto done; 657 658 case COMPST_EXIT: 659 if (qp->comp.timeout_retry && wqe) { 660 state = COMPST_ERROR_RETRY; 661 break; 662 } 663 664 /* re reset the timeout counter if 665 * (1) QP is type RC 666 * (2) the QP is alive 667 * (3) there is a packet sent by the requester that 668 * might be acked (we still might get spurious 669 * timeouts but try to keep them as few as possible) 670 * (4) the timeout parameter is set 671 */ 672 if ((qp_type(qp) == IB_QPT_RC) && 673 (qp->req.state == QP_STATE_READY) && 674 (psn_compare(qp->req.psn, qp->comp.psn) > 0) && 675 qp->qp_timeout_jiffies) 676 mod_timer(&qp->retrans_timer, 677 jiffies + qp->qp_timeout_jiffies); 678 goto exit; 679 680 case COMPST_ERROR_RETRY: 681 /* we come here if the retry timer fired and we did 682 * not receive a response packet. try to retry the send 683 * queue if that makes sense and the limits have not 684 * been exceeded. remember that some timeouts are 685 * spurious since we do not reset the timer but kick 686 * it down the road or let it expire 687 */ 688 689 /* there is nothing to retry in this case */ 690 if (!wqe || (wqe->state == wqe_state_posted)) 691 goto exit; 692 693 /* if we've started a retry, don't start another 694 * retry sequence, unless this is a timeout. 695 */ 696 if (qp->comp.started_retry && 697 !qp->comp.timeout_retry) 698 goto done; 699 700 if (qp->comp.retry_cnt > 0) { 701 if (qp->comp.retry_cnt != 7) 702 qp->comp.retry_cnt--; 703 704 /* no point in retrying if we have already 705 * seen the last ack that the requester could 706 * have caused 707 */ 708 if (psn_compare(qp->req.psn, 709 qp->comp.psn) > 0) { 710 /* tell the requester to retry the 711 * send queue next time around 712 */ 713 rxe_counter_inc(rxe, 714 RXE_CNT_COMP_RETRY); 715 qp->req.need_retry = 1; 716 qp->comp.started_retry = 1; 717 rxe_run_task(&qp->req.task, 0); 718 } 719 goto done; 720 721 } else { 722 rxe_counter_inc(rxe, RXE_CNT_RETRY_EXCEEDED); 723 wqe->status = IB_WC_RETRY_EXC_ERR; 724 state = COMPST_ERROR; 725 } 726 break; 727 728 case COMPST_RNR_RETRY: 729 /* we come here if we received an RNR NAK */ 730 if (qp->comp.rnr_retry > 0) { 731 if (qp->comp.rnr_retry != 7) 732 qp->comp.rnr_retry--; 733 734 /* don't start a retry flow until the 735 * rnr timer has fired 736 */ 737 qp->req.wait_for_rnr_timer = 1; 738 pr_debug("qp#%d set rnr nak timer\n", 739 qp_num(qp)); 740 mod_timer(&qp->rnr_nak_timer, 741 jiffies + rnrnak_jiffies(aeth_syn(pkt) 742 & ~AETH_TYPE_MASK)); 743 goto exit; 744 } else { 745 rxe_counter_inc(rxe, 746 RXE_CNT_RNR_RETRY_EXCEEDED); 747 wqe->status = IB_WC_RNR_RETRY_EXC_ERR; 748 state = COMPST_ERROR; 749 } 750 break; 751 752 case COMPST_ERROR: 753 WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS); 754 do_complete(qp, wqe); 755 rxe_qp_error(qp); 756 goto exit; 757 } 758 } 759 760 /* A non-zero return value will cause rxe_do_task to 761 * exit its loop and end the tasklet. A zero return 762 * will continue looping and return to rxe_completer 763 */ 764 done: 765 ret = 0; 766 goto out; 767 exit: 768 ret = -EAGAIN; 769 out: 770 if (pkt) 771 free_pkt(pkt); 772 rxe_put(qp); 773 774 return ret; 775 } 776