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 } 842