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 if (qp->valid) { 122 qp->comp.timeout = 1; 123 rxe_sched_task(&qp->comp.task); 124 } 125 } 126 127 void rxe_comp_queue_pkt(struct rxe_qp *qp, struct sk_buff *skb) 128 { 129 int must_sched; 130 131 skb_queue_tail(&qp->resp_pkts, skb); 132 133 must_sched = skb_queue_len(&qp->resp_pkts) > 1; 134 if (must_sched != 0) 135 rxe_counter_inc(SKB_TO_PKT(skb)->rxe, RXE_CNT_COMPLETER_SCHED); 136 137 if (must_sched) 138 rxe_sched_task(&qp->comp.task); 139 else 140 rxe_run_task(&qp->comp.task); 141 } 142 143 static inline enum comp_state get_wqe(struct rxe_qp *qp, 144 struct rxe_pkt_info *pkt, 145 struct rxe_send_wqe **wqe_p) 146 { 147 struct rxe_send_wqe *wqe; 148 149 /* we come here whether or not we found a response packet to see if 150 * there are any posted WQEs 151 */ 152 wqe = queue_head(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT); 153 *wqe_p = wqe; 154 155 /* no WQE or requester has not started it yet */ 156 if (!wqe || wqe->state == wqe_state_posted) 157 return pkt ? COMPST_DONE : COMPST_EXIT; 158 159 /* WQE does not require an ack */ 160 if (wqe->state == wqe_state_done) 161 return COMPST_COMP_WQE; 162 163 /* WQE caused an error */ 164 if (wqe->state == wqe_state_error) 165 return COMPST_ERROR; 166 167 /* we have a WQE, if we also have an ack check its PSN */ 168 return pkt ? COMPST_CHECK_PSN : COMPST_EXIT; 169 } 170 171 static inline void reset_retry_counters(struct rxe_qp *qp) 172 { 173 qp->comp.retry_cnt = qp->attr.retry_cnt; 174 qp->comp.rnr_retry = qp->attr.rnr_retry; 175 qp->comp.started_retry = 0; 176 } 177 178 static inline enum comp_state check_psn(struct rxe_qp *qp, 179 struct rxe_pkt_info *pkt, 180 struct rxe_send_wqe *wqe) 181 { 182 s32 diff; 183 184 /* check to see if response is past the oldest WQE. if it is, complete 185 * send/write or error read/atomic 186 */ 187 diff = psn_compare(pkt->psn, wqe->last_psn); 188 if (diff > 0) { 189 if (wqe->state == wqe_state_pending) { 190 if (wqe->mask & WR_ATOMIC_OR_READ_MASK) 191 return COMPST_ERROR_RETRY; 192 193 reset_retry_counters(qp); 194 return COMPST_COMP_WQE; 195 } else { 196 return COMPST_DONE; 197 } 198 } 199 200 /* compare response packet to expected response */ 201 diff = psn_compare(pkt->psn, qp->comp.psn); 202 if (diff < 0) { 203 /* response is most likely a retried packet if it matches an 204 * uncompleted WQE go complete it else ignore it 205 */ 206 if (pkt->psn == wqe->last_psn) 207 return COMPST_COMP_ACK; 208 else if (pkt->opcode == IB_OPCODE_RC_ACKNOWLEDGE && 209 (qp->comp.opcode == IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST || 210 qp->comp.opcode == IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE)) 211 return COMPST_CHECK_ACK; 212 else 213 return COMPST_DONE; 214 } else if ((diff > 0) && (wqe->mask & WR_ATOMIC_OR_READ_MASK)) { 215 return COMPST_DONE; 216 } else { 217 return COMPST_CHECK_ACK; 218 } 219 } 220 221 static inline enum comp_state check_ack(struct rxe_qp *qp, 222 struct rxe_pkt_info *pkt, 223 struct rxe_send_wqe *wqe) 224 { 225 unsigned int mask = pkt->mask; 226 u8 syn; 227 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 228 229 /* Check the sequence only */ 230 switch (qp->comp.opcode) { 231 case -1: 232 /* Will catch all *_ONLY cases. */ 233 if (!(mask & RXE_START_MASK)) 234 return COMPST_ERROR; 235 236 break; 237 238 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 239 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 240 /* Check NAK code to handle a remote error */ 241 if (pkt->opcode == IB_OPCODE_RC_ACKNOWLEDGE) 242 break; 243 244 if (pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE && 245 pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST) { 246 /* read retries of partial data may restart from 247 * read response first or response only. 248 */ 249 if ((pkt->psn == wqe->first_psn && 250 pkt->opcode == 251 IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) || 252 (wqe->first_psn == wqe->last_psn && 253 pkt->opcode == 254 IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY)) 255 break; 256 257 return COMPST_ERROR; 258 } 259 break; 260 default: 261 WARN_ON_ONCE(1); 262 } 263 264 /* Check operation validity. */ 265 switch (pkt->opcode) { 266 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 267 case IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST: 268 case IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY: 269 syn = aeth_syn(pkt); 270 271 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 272 return COMPST_ERROR; 273 274 if (wqe->wr.opcode == IB_WR_ATOMIC_WRITE) 275 return COMPST_WRITE_SEND; 276 277 fallthrough; 278 /* (IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE doesn't have an AETH) 279 */ 280 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 281 if (wqe->wr.opcode != IB_WR_RDMA_READ && 282 wqe->wr.opcode != IB_WR_RDMA_READ_WITH_INV && 283 wqe->wr.opcode != IB_WR_FLUSH) { 284 wqe->status = IB_WC_FATAL_ERR; 285 return COMPST_ERROR; 286 } 287 reset_retry_counters(qp); 288 return COMPST_READ; 289 290 case IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE: 291 syn = aeth_syn(pkt); 292 293 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 294 return COMPST_ERROR; 295 296 if (wqe->wr.opcode != IB_WR_ATOMIC_CMP_AND_SWP && 297 wqe->wr.opcode != IB_WR_ATOMIC_FETCH_AND_ADD) 298 return COMPST_ERROR; 299 reset_retry_counters(qp); 300 return COMPST_ATOMIC; 301 302 case IB_OPCODE_RC_ACKNOWLEDGE: 303 syn = aeth_syn(pkt); 304 switch (syn & AETH_TYPE_MASK) { 305 case AETH_ACK: 306 reset_retry_counters(qp); 307 return COMPST_WRITE_SEND; 308 309 case AETH_RNR_NAK: 310 rxe_counter_inc(rxe, RXE_CNT_RCV_RNR); 311 return COMPST_RNR_RETRY; 312 313 case AETH_NAK: 314 switch (syn) { 315 case AETH_NAK_PSN_SEQ_ERROR: 316 /* a nak implicitly acks all packets with psns 317 * before 318 */ 319 if (psn_compare(pkt->psn, qp->comp.psn) > 0) { 320 rxe_counter_inc(rxe, 321 RXE_CNT_RCV_SEQ_ERR); 322 qp->comp.psn = pkt->psn; 323 if (qp->req.wait_psn) { 324 qp->req.wait_psn = 0; 325 rxe_run_task(&qp->req.task); 326 } 327 } 328 return COMPST_ERROR_RETRY; 329 330 case AETH_NAK_INVALID_REQ: 331 wqe->status = IB_WC_REM_INV_REQ_ERR; 332 return COMPST_ERROR; 333 334 case AETH_NAK_REM_ACC_ERR: 335 wqe->status = IB_WC_REM_ACCESS_ERR; 336 return COMPST_ERROR; 337 338 case AETH_NAK_REM_OP_ERR: 339 wqe->status = IB_WC_REM_OP_ERR; 340 return COMPST_ERROR; 341 342 default: 343 rxe_dbg_qp(qp, "unexpected nak %x\n", syn); 344 wqe->status = IB_WC_REM_OP_ERR; 345 return COMPST_ERROR; 346 } 347 348 default: 349 return COMPST_ERROR; 350 } 351 break; 352 353 default: 354 rxe_dbg_qp(qp, "unexpected opcode\n"); 355 } 356 357 return COMPST_ERROR; 358 } 359 360 static inline enum comp_state do_read(struct rxe_qp *qp, 361 struct rxe_pkt_info *pkt, 362 struct rxe_send_wqe *wqe) 363 { 364 int ret; 365 366 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, 367 &wqe->dma, payload_addr(pkt), 368 payload_size(pkt), RXE_TO_MR_OBJ); 369 if (ret) { 370 wqe->status = IB_WC_LOC_PROT_ERR; 371 return COMPST_ERROR; 372 } 373 374 if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK)) 375 return COMPST_COMP_ACK; 376 377 return COMPST_UPDATE_COMP; 378 } 379 380 static inline enum comp_state do_atomic(struct rxe_qp *qp, 381 struct rxe_pkt_info *pkt, 382 struct rxe_send_wqe *wqe) 383 { 384 int ret; 385 386 u64 atomic_orig = atmack_orig(pkt); 387 388 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, 389 &wqe->dma, &atomic_orig, 390 sizeof(u64), RXE_TO_MR_OBJ); 391 if (ret) { 392 wqe->status = IB_WC_LOC_PROT_ERR; 393 return COMPST_ERROR; 394 } 395 396 return COMPST_COMP_ACK; 397 } 398 399 static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe, 400 struct rxe_cqe *cqe) 401 { 402 struct ib_wc *wc = &cqe->ibwc; 403 struct ib_uverbs_wc *uwc = &cqe->uibwc; 404 405 memset(cqe, 0, sizeof(*cqe)); 406 407 if (!qp->is_user) { 408 wc->wr_id = wqe->wr.wr_id; 409 wc->status = wqe->status; 410 wc->qp = &qp->ibqp; 411 } else { 412 uwc->wr_id = wqe->wr.wr_id; 413 uwc->status = wqe->status; 414 uwc->qp_num = qp->ibqp.qp_num; 415 } 416 417 if (wqe->status == IB_WC_SUCCESS) { 418 if (!qp->is_user) { 419 wc->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 wc->wc_flags = IB_WC_WITH_IMM; 423 wc->byte_len = wqe->dma.length; 424 } else { 425 uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 426 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 427 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 428 uwc->wc_flags = IB_WC_WITH_IMM; 429 uwc->byte_len = wqe->dma.length; 430 } 431 } 432 } 433 434 /* 435 * IBA Spec. Section 10.7.3.1 SIGNALED COMPLETIONS 436 * ---------8<---------8<------------- 437 * ...Note that if a completion error occurs, a Work Completion 438 * will always be generated, even if the signaling 439 * indicator requests an Unsignaled Completion. 440 * ---------8<---------8<------------- 441 */ 442 static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe) 443 { 444 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 445 struct rxe_cqe cqe; 446 bool post; 447 448 /* do we need to post a completion */ 449 post = ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) || 450 (wqe->wr.send_flags & IB_SEND_SIGNALED) || 451 wqe->status != IB_WC_SUCCESS); 452 453 if (post) 454 make_send_cqe(qp, wqe, &cqe); 455 456 queue_advance_consumer(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT); 457 458 if (post) 459 rxe_cq_post(qp->scq, &cqe, 0); 460 461 if (wqe->wr.opcode == IB_WR_SEND || 462 wqe->wr.opcode == IB_WR_SEND_WITH_IMM || 463 wqe->wr.opcode == IB_WR_SEND_WITH_INV) 464 rxe_counter_inc(rxe, RXE_CNT_RDMA_SEND); 465 466 /* 467 * we completed something so let req run again 468 * if it is trying to fence 469 */ 470 if (qp->req.wait_fence) { 471 qp->req.wait_fence = 0; 472 rxe_run_task(&qp->req.task); 473 } 474 } 475 476 static inline enum comp_state complete_ack(struct rxe_qp *qp, 477 struct rxe_pkt_info *pkt, 478 struct rxe_send_wqe *wqe) 479 { 480 if (wqe->has_rd_atomic) { 481 wqe->has_rd_atomic = 0; 482 atomic_inc(&qp->req.rd_atomic); 483 if (qp->req.need_rd_atomic) { 484 qp->comp.timeout_retry = 0; 485 qp->req.need_rd_atomic = 0; 486 rxe_run_task(&qp->req.task); 487 } 488 } 489 490 if (unlikely(qp->req.state == QP_STATE_DRAIN)) { 491 /* state_lock used by requester & completer */ 492 spin_lock_bh(&qp->state_lock); 493 if ((qp->req.state == QP_STATE_DRAIN) && 494 (qp->comp.psn == qp->req.psn)) { 495 qp->req.state = QP_STATE_DRAINED; 496 spin_unlock_bh(&qp->state_lock); 497 498 if (qp->ibqp.event_handler) { 499 struct ib_event ev; 500 501 ev.device = qp->ibqp.device; 502 ev.element.qp = &qp->ibqp; 503 ev.event = IB_EVENT_SQ_DRAINED; 504 qp->ibqp.event_handler(&ev, 505 qp->ibqp.qp_context); 506 } 507 } else { 508 spin_unlock_bh(&qp->state_lock); 509 } 510 } 511 512 do_complete(qp, wqe); 513 514 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 515 return COMPST_UPDATE_COMP; 516 else 517 return COMPST_DONE; 518 } 519 520 static inline enum comp_state complete_wqe(struct rxe_qp *qp, 521 struct rxe_pkt_info *pkt, 522 struct rxe_send_wqe *wqe) 523 { 524 if (pkt && wqe->state == wqe_state_pending) { 525 if (psn_compare(wqe->last_psn, qp->comp.psn) >= 0) { 526 qp->comp.psn = (wqe->last_psn + 1) & BTH_PSN_MASK; 527 qp->comp.opcode = -1; 528 } 529 530 if (qp->req.wait_psn) { 531 qp->req.wait_psn = 0; 532 rxe_sched_task(&qp->req.task); 533 } 534 } 535 536 do_complete(qp, wqe); 537 538 return COMPST_GET_WQE; 539 } 540 541 static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify) 542 { 543 struct sk_buff *skb; 544 struct rxe_send_wqe *wqe; 545 struct rxe_queue *q = qp->sq.queue; 546 547 while ((skb = skb_dequeue(&qp->resp_pkts))) { 548 rxe_put(qp); 549 kfree_skb(skb); 550 ib_device_put(qp->ibqp.device); 551 } 552 553 while ((wqe = queue_head(q, q->type))) { 554 if (notify) { 555 wqe->status = IB_WC_WR_FLUSH_ERR; 556 do_complete(qp, wqe); 557 } else { 558 queue_advance_consumer(q, q->type); 559 } 560 } 561 } 562 563 static void free_pkt(struct rxe_pkt_info *pkt) 564 { 565 struct sk_buff *skb = PKT_TO_SKB(pkt); 566 struct rxe_qp *qp = pkt->qp; 567 struct ib_device *dev = qp->ibqp.device; 568 569 kfree_skb(skb); 570 rxe_put(qp); 571 ib_device_put(dev); 572 } 573 574 int rxe_completer(void *arg) 575 { 576 struct rxe_qp *qp = (struct rxe_qp *)arg; 577 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 578 struct rxe_send_wqe *wqe = NULL; 579 struct sk_buff *skb = NULL; 580 struct rxe_pkt_info *pkt = NULL; 581 enum comp_state state; 582 int ret; 583 584 if (!rxe_get(qp)) 585 return -EAGAIN; 586 587 if (!qp->valid || qp->comp.state == QP_STATE_ERROR || 588 qp->comp.state == QP_STATE_RESET) { 589 rxe_drain_resp_pkts(qp, qp->valid && 590 qp->comp.state == QP_STATE_ERROR); 591 goto exit; 592 } 593 594 if (qp->comp.timeout) { 595 qp->comp.timeout_retry = 1; 596 qp->comp.timeout = 0; 597 } else { 598 qp->comp.timeout_retry = 0; 599 } 600 601 if (qp->req.need_retry) 602 goto exit; 603 604 state = COMPST_GET_ACK; 605 606 while (1) { 607 rxe_dbg_qp(qp, "state = %s\n", comp_state_name[state]); 608 switch (state) { 609 case COMPST_GET_ACK: 610 skb = skb_dequeue(&qp->resp_pkts); 611 if (skb) { 612 pkt = SKB_TO_PKT(skb); 613 qp->comp.timeout_retry = 0; 614 } 615 state = COMPST_GET_WQE; 616 break; 617 618 case COMPST_GET_WQE: 619 state = get_wqe(qp, pkt, &wqe); 620 break; 621 622 case COMPST_CHECK_PSN: 623 state = check_psn(qp, pkt, wqe); 624 break; 625 626 case COMPST_CHECK_ACK: 627 state = check_ack(qp, pkt, wqe); 628 break; 629 630 case COMPST_READ: 631 state = do_read(qp, pkt, wqe); 632 break; 633 634 case COMPST_ATOMIC: 635 state = do_atomic(qp, pkt, wqe); 636 break; 637 638 case COMPST_WRITE_SEND: 639 if (wqe->state == wqe_state_pending && 640 wqe->last_psn == pkt->psn) 641 state = COMPST_COMP_ACK; 642 else 643 state = COMPST_UPDATE_COMP; 644 break; 645 646 case COMPST_COMP_ACK: 647 state = complete_ack(qp, pkt, wqe); 648 break; 649 650 case COMPST_COMP_WQE: 651 state = complete_wqe(qp, pkt, wqe); 652 break; 653 654 case COMPST_UPDATE_COMP: 655 if (pkt->mask & RXE_END_MASK) 656 qp->comp.opcode = -1; 657 else 658 qp->comp.opcode = pkt->opcode; 659 660 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 661 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; 662 663 if (qp->req.wait_psn) { 664 qp->req.wait_psn = 0; 665 rxe_sched_task(&qp->req.task); 666 } 667 668 state = COMPST_DONE; 669 break; 670 671 case COMPST_DONE: 672 goto done; 673 674 case COMPST_EXIT: 675 if (qp->comp.timeout_retry && wqe) { 676 state = COMPST_ERROR_RETRY; 677 break; 678 } 679 680 /* re reset the timeout counter if 681 * (1) QP is type RC 682 * (2) the QP is alive 683 * (3) there is a packet sent by the requester that 684 * might be acked (we still might get spurious 685 * timeouts but try to keep them as few as possible) 686 * (4) the timeout parameter is set 687 */ 688 if ((qp_type(qp) == IB_QPT_RC) && 689 (qp->req.state == QP_STATE_READY) && 690 (psn_compare(qp->req.psn, qp->comp.psn) > 0) && 691 qp->qp_timeout_jiffies) 692 mod_timer(&qp->retrans_timer, 693 jiffies + qp->qp_timeout_jiffies); 694 goto exit; 695 696 case COMPST_ERROR_RETRY: 697 /* we come here if the retry timer fired and we did 698 * not receive a response packet. try to retry the send 699 * queue if that makes sense and the limits have not 700 * been exceeded. remember that some timeouts are 701 * spurious since we do not reset the timer but kick 702 * it down the road or let it expire 703 */ 704 705 /* there is nothing to retry in this case */ 706 if (!wqe || (wqe->state == wqe_state_posted)) 707 goto exit; 708 709 /* if we've started a retry, don't start another 710 * retry sequence, unless this is a timeout. 711 */ 712 if (qp->comp.started_retry && 713 !qp->comp.timeout_retry) 714 goto done; 715 716 if (qp->comp.retry_cnt > 0) { 717 if (qp->comp.retry_cnt != 7) 718 qp->comp.retry_cnt--; 719 720 /* no point in retrying if we have already 721 * seen the last ack that the requester could 722 * have caused 723 */ 724 if (psn_compare(qp->req.psn, 725 qp->comp.psn) > 0) { 726 /* tell the requester to retry the 727 * send queue next time around 728 */ 729 rxe_counter_inc(rxe, 730 RXE_CNT_COMP_RETRY); 731 qp->req.need_retry = 1; 732 qp->comp.started_retry = 1; 733 rxe_run_task(&qp->req.task); 734 } 735 goto done; 736 737 } else { 738 rxe_counter_inc(rxe, RXE_CNT_RETRY_EXCEEDED); 739 wqe->status = IB_WC_RETRY_EXC_ERR; 740 state = COMPST_ERROR; 741 } 742 break; 743 744 case COMPST_RNR_RETRY: 745 /* we come here if we received an RNR NAK */ 746 if (qp->comp.rnr_retry > 0) { 747 if (qp->comp.rnr_retry != 7) 748 qp->comp.rnr_retry--; 749 750 /* don't start a retry flow until the 751 * rnr timer has fired 752 */ 753 qp->req.wait_for_rnr_timer = 1; 754 rxe_dbg_qp(qp, "set rnr nak timer\n"); 755 mod_timer(&qp->rnr_nak_timer, 756 jiffies + rnrnak_jiffies(aeth_syn(pkt) 757 & ~AETH_TYPE_MASK)); 758 goto exit; 759 } else { 760 rxe_counter_inc(rxe, 761 RXE_CNT_RNR_RETRY_EXCEEDED); 762 wqe->status = IB_WC_RNR_RETRY_EXC_ERR; 763 state = COMPST_ERROR; 764 } 765 break; 766 767 case COMPST_ERROR: 768 WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS); 769 do_complete(qp, wqe); 770 rxe_qp_error(qp); 771 goto exit; 772 } 773 } 774 775 /* A non-zero return value will cause rxe_do_task to 776 * exit its loop and end the tasklet. A zero return 777 * will continue looping and return to rxe_completer 778 */ 779 done: 780 ret = 0; 781 goto out; 782 exit: 783 ret = -EAGAIN; 784 out: 785 if (pkt) 786 free_pkt(pkt); 787 rxe_put(qp); 788 789 return ret; 790 } 791