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 = timer_container_of(qp, t, retrans_timer); 118 unsigned long flags; 119 120 rxe_dbg_qp(qp, "retransmit timer fired\n"); 121 122 if (!rxe_get(qp)) 123 return; 124 spin_lock_irqsave(&qp->state_lock, flags); 125 if (qp->valid) { 126 qp->comp.timeout = 1; 127 rxe_sched_task(&qp->send_task); 128 } 129 spin_unlock_irqrestore(&qp->state_lock, flags); 130 rxe_put(qp); 131 } 132 133 void rxe_comp_queue_pkt(struct rxe_qp *qp, struct sk_buff *skb) 134 { 135 rxe_counter_inc(SKB_TO_PKT(skb)->rxe, RXE_CNT_SENDER_SCHED); 136 skb_queue_tail(&qp->resp_pkts, skb); 137 rxe_sched_task(&qp->send_task); 138 } 139 140 static inline enum comp_state get_wqe(struct rxe_qp *qp, 141 struct rxe_pkt_info *pkt, 142 struct rxe_send_wqe **wqe_p) 143 { 144 struct rxe_send_wqe *wqe; 145 146 /* we come here whether or not we found a response packet to see if 147 * there are any posted WQEs 148 */ 149 wqe = queue_head(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT); 150 *wqe_p = wqe; 151 152 /* no WQE or requester has not started it yet */ 153 if (!wqe || wqe->state == wqe_state_posted) 154 return pkt ? COMPST_DONE : COMPST_EXIT; 155 156 /* WQE does not require an ack */ 157 if (wqe->state == wqe_state_done) 158 return COMPST_COMP_WQE; 159 160 /* WQE caused an error */ 161 if (wqe->state == wqe_state_error) 162 return COMPST_ERROR; 163 164 /* we have a WQE, if we also have an ack check its PSN */ 165 return pkt ? COMPST_CHECK_PSN : COMPST_EXIT; 166 } 167 168 static inline void reset_retry_counters(struct rxe_qp *qp) 169 { 170 qp->comp.retry_cnt = qp->attr.retry_cnt; 171 qp->comp.rnr_retry = qp->attr.rnr_retry; 172 qp->comp.started_retry = 0; 173 } 174 175 static inline enum comp_state check_psn(struct rxe_qp *qp, 176 struct rxe_pkt_info *pkt, 177 struct rxe_send_wqe *wqe) 178 { 179 s32 diff; 180 181 /* check to see if response is past the oldest WQE. if it is, complete 182 * send/write or error read/atomic 183 */ 184 diff = psn_compare(pkt->psn, wqe->last_psn); 185 if (diff > 0) { 186 if (wqe->state == wqe_state_pending) { 187 if (wqe->mask & WR_ATOMIC_OR_READ_MASK) 188 return COMPST_ERROR_RETRY; 189 190 reset_retry_counters(qp); 191 return COMPST_COMP_WQE; 192 } else { 193 return COMPST_DONE; 194 } 195 } 196 197 /* compare response packet to expected response */ 198 diff = psn_compare(pkt->psn, qp->comp.psn); 199 if (diff < 0) { 200 /* response is most likely a retried packet if it matches an 201 * uncompleted WQE go complete it else ignore it 202 */ 203 if (pkt->psn == wqe->last_psn) 204 return COMPST_COMP_ACK; 205 else if (pkt->opcode == IB_OPCODE_RC_ACKNOWLEDGE && 206 (qp->comp.opcode == IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST || 207 qp->comp.opcode == IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE)) 208 return COMPST_CHECK_ACK; 209 else 210 return COMPST_DONE; 211 } else if ((diff > 0) && (wqe->mask & WR_ATOMIC_OR_READ_MASK)) { 212 return COMPST_DONE; 213 } else { 214 return COMPST_CHECK_ACK; 215 } 216 } 217 218 static inline enum comp_state check_ack(struct rxe_qp *qp, 219 struct rxe_pkt_info *pkt, 220 struct rxe_send_wqe *wqe) 221 { 222 unsigned int mask = pkt->mask; 223 u8 syn; 224 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 225 226 /* Check the sequence only */ 227 switch (qp->comp.opcode) { 228 case -1: 229 /* Will catch all *_ONLY cases. */ 230 if (!(mask & RXE_START_MASK)) 231 return COMPST_ERROR; 232 233 break; 234 235 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 236 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 237 /* Check NAK code to handle a remote error */ 238 if (pkt->opcode == IB_OPCODE_RC_ACKNOWLEDGE) 239 break; 240 241 if (pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE && 242 pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST) { 243 /* read retries of partial data may restart from 244 * read response first or response only. 245 */ 246 if ((pkt->psn == wqe->first_psn && 247 pkt->opcode == 248 IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) || 249 (wqe->first_psn == wqe->last_psn && 250 pkt->opcode == 251 IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY)) 252 break; 253 254 return COMPST_ERROR; 255 } 256 break; 257 default: 258 WARN_ON_ONCE(1); 259 } 260 261 /* Check operation validity. */ 262 switch (pkt->opcode) { 263 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 264 case IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST: 265 case IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY: 266 syn = aeth_syn(pkt); 267 268 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 269 return COMPST_ERROR; 270 271 if (wqe->wr.opcode == IB_WR_ATOMIC_WRITE) 272 return COMPST_WRITE_SEND; 273 274 fallthrough; 275 /* (IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE doesn't have an AETH) 276 */ 277 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 278 if (wqe->wr.opcode != IB_WR_RDMA_READ && 279 wqe->wr.opcode != IB_WR_RDMA_READ_WITH_INV && 280 wqe->wr.opcode != IB_WR_FLUSH) { 281 wqe->status = IB_WC_FATAL_ERR; 282 return COMPST_ERROR; 283 } 284 reset_retry_counters(qp); 285 return COMPST_READ; 286 287 case IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE: 288 syn = aeth_syn(pkt); 289 290 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 291 return COMPST_ERROR; 292 293 if (wqe->wr.opcode != IB_WR_ATOMIC_CMP_AND_SWP && 294 wqe->wr.opcode != IB_WR_ATOMIC_FETCH_AND_ADD) 295 return COMPST_ERROR; 296 reset_retry_counters(qp); 297 return COMPST_ATOMIC; 298 299 case IB_OPCODE_RC_ACKNOWLEDGE: 300 syn = aeth_syn(pkt); 301 switch (syn & AETH_TYPE_MASK) { 302 case AETH_ACK: 303 reset_retry_counters(qp); 304 return COMPST_WRITE_SEND; 305 306 case AETH_RNR_NAK: 307 rxe_counter_inc(rxe, RXE_CNT_RCV_RNR); 308 return COMPST_RNR_RETRY; 309 310 case AETH_NAK: 311 switch (syn) { 312 case AETH_NAK_PSN_SEQ_ERROR: 313 /* a nak implicitly acks all packets with psns 314 * before 315 */ 316 if (psn_compare(pkt->psn, qp->comp.psn) > 0) { 317 rxe_counter_inc(rxe, 318 RXE_CNT_RCV_SEQ_ERR); 319 qp->comp.psn = pkt->psn; 320 if (qp->req.wait_psn) { 321 qp->req.wait_psn = 0; 322 qp->req.again = 1; 323 } 324 } 325 return COMPST_ERROR_RETRY; 326 327 case AETH_NAK_INVALID_REQ: 328 wqe->status = IB_WC_REM_INV_REQ_ERR; 329 return COMPST_ERROR; 330 331 case AETH_NAK_REM_ACC_ERR: 332 wqe->status = IB_WC_REM_ACCESS_ERR; 333 return COMPST_ERROR; 334 335 case AETH_NAK_REM_OP_ERR: 336 wqe->status = IB_WC_REM_OP_ERR; 337 return COMPST_ERROR; 338 339 default: 340 rxe_dbg_qp(qp, "unexpected nak %x\n", syn); 341 wqe->status = IB_WC_REM_OP_ERR; 342 return COMPST_ERROR; 343 } 344 345 default: 346 return COMPST_ERROR; 347 } 348 break; 349 350 default: 351 rxe_dbg_qp(qp, "unexpected opcode\n"); 352 } 353 354 return COMPST_ERROR; 355 } 356 357 static inline enum comp_state do_read(struct rxe_qp *qp, 358 struct rxe_pkt_info *pkt, 359 struct rxe_send_wqe *wqe) 360 { 361 int ret; 362 363 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, 364 &wqe->dma, payload_addr(pkt), 365 payload_size(pkt), RXE_TO_MR_OBJ); 366 if (ret) { 367 wqe->status = IB_WC_LOC_PROT_ERR; 368 return COMPST_ERROR; 369 } 370 371 if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK)) 372 return COMPST_COMP_ACK; 373 374 return COMPST_UPDATE_COMP; 375 } 376 377 static inline enum comp_state do_atomic(struct rxe_qp *qp, 378 struct rxe_pkt_info *pkt, 379 struct rxe_send_wqe *wqe) 380 { 381 int ret; 382 383 u64 atomic_orig = atmack_orig(pkt); 384 385 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, 386 &wqe->dma, &atomic_orig, 387 sizeof(u64), RXE_TO_MR_OBJ); 388 if (ret) { 389 wqe->status = IB_WC_LOC_PROT_ERR; 390 return COMPST_ERROR; 391 } 392 393 return COMPST_COMP_ACK; 394 } 395 396 static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe, 397 struct rxe_cqe *cqe) 398 { 399 struct ib_wc *wc = &cqe->ibwc; 400 struct ib_uverbs_wc *uwc = &cqe->uibwc; 401 402 memset(cqe, 0, sizeof(*cqe)); 403 404 if (!qp->is_user) { 405 wc->wr_id = wqe->wr.wr_id; 406 wc->status = wqe->status; 407 wc->qp = &qp->ibqp; 408 } else { 409 uwc->wr_id = wqe->wr.wr_id; 410 uwc->status = wqe->status; 411 uwc->qp_num = qp->ibqp.qp_num; 412 } 413 414 if (wqe->status == IB_WC_SUCCESS) { 415 if (!qp->is_user) { 416 wc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 417 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 418 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 419 wc->wc_flags = IB_WC_WITH_IMM; 420 wc->byte_len = wqe->dma.length; 421 } else { 422 uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 423 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 424 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 425 uwc->wc_flags = IB_WC_WITH_IMM; 426 uwc->byte_len = wqe->dma.length; 427 } 428 } else { 429 if (wqe->status != IB_WC_WR_FLUSH_ERR) 430 rxe_err_qp(qp, "non-flush error status = %d\n", 431 wqe->status); 432 } 433 } 434 435 /* 436 * IBA Spec. Section 10.7.3.1 SIGNALED COMPLETIONS 437 * ---------8<---------8<------------- 438 * ...Note that if a completion error occurs, a Work Completion 439 * will always be generated, even if the signaling 440 * indicator requests an Unsignaled Completion. 441 * ---------8<---------8<------------- 442 */ 443 static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe) 444 { 445 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 446 struct rxe_cqe cqe; 447 bool post; 448 449 /* do we need to post a completion */ 450 post = ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) || 451 (wqe->wr.send_flags & IB_SEND_SIGNALED) || 452 wqe->status != IB_WC_SUCCESS); 453 454 if (post) 455 make_send_cqe(qp, wqe, &cqe); 456 457 queue_advance_consumer(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT); 458 459 if (post) 460 rxe_cq_post(qp->scq, &cqe, 0); 461 462 if (wqe->wr.opcode == IB_WR_SEND || 463 wqe->wr.opcode == IB_WR_SEND_WITH_IMM || 464 wqe->wr.opcode == IB_WR_SEND_WITH_INV) 465 rxe_counter_inc(rxe, RXE_CNT_RDMA_SEND); 466 467 /* 468 * we completed something so let req run again 469 * if it is trying to fence 470 */ 471 if (qp->req.wait_fence) { 472 qp->req.wait_fence = 0; 473 qp->req.again = 1; 474 } 475 } 476 477 static void comp_check_sq_drain_done(struct rxe_qp *qp) 478 { 479 unsigned long flags; 480 481 spin_lock_irqsave(&qp->state_lock, flags); 482 if (unlikely(qp_state(qp) == IB_QPS_SQD)) { 483 if (qp->attr.sq_draining && qp->comp.psn == qp->req.psn) { 484 qp->attr.sq_draining = 0; 485 spin_unlock_irqrestore(&qp->state_lock, flags); 486 487 if (qp->ibqp.event_handler) { 488 struct ib_event ev; 489 490 ev.device = qp->ibqp.device; 491 ev.element.qp = &qp->ibqp; 492 ev.event = IB_EVENT_SQ_DRAINED; 493 qp->ibqp.event_handler(&ev, 494 qp->ibqp.qp_context); 495 } 496 return; 497 } 498 } 499 spin_unlock_irqrestore(&qp->state_lock, flags); 500 } 501 502 static inline enum comp_state complete_ack(struct rxe_qp *qp, 503 struct rxe_pkt_info *pkt, 504 struct rxe_send_wqe *wqe) 505 { 506 if (wqe->has_rd_atomic) { 507 wqe->has_rd_atomic = 0; 508 atomic_inc(&qp->req.rd_atomic); 509 if (qp->req.need_rd_atomic) { 510 qp->comp.timeout_retry = 0; 511 qp->req.need_rd_atomic = 0; 512 qp->req.again = 1; 513 } 514 } 515 516 comp_check_sq_drain_done(qp); 517 518 do_complete(qp, wqe); 519 520 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 521 return COMPST_UPDATE_COMP; 522 else 523 return COMPST_DONE; 524 } 525 526 static inline enum comp_state complete_wqe(struct rxe_qp *qp, 527 struct rxe_pkt_info *pkt, 528 struct rxe_send_wqe *wqe) 529 { 530 if (pkt && wqe->state == wqe_state_pending) { 531 if (psn_compare(wqe->last_psn, qp->comp.psn) >= 0) { 532 qp->comp.psn = (wqe->last_psn + 1) & BTH_PSN_MASK; 533 qp->comp.opcode = -1; 534 } 535 536 if (qp->req.wait_psn) { 537 qp->req.wait_psn = 0; 538 qp->req.again = 1; 539 } 540 } 541 542 do_complete(qp, wqe); 543 544 return COMPST_GET_WQE; 545 } 546 547 /* drain incoming response packet queue */ 548 static void drain_resp_pkts(struct rxe_qp *qp) 549 { 550 struct sk_buff *skb; 551 552 while ((skb = skb_dequeue(&qp->resp_pkts))) { 553 rxe_put(qp); 554 kfree_skb(skb); 555 ib_device_put(qp->ibqp.device); 556 } 557 } 558 559 /* complete send wqe with flush error */ 560 static int flush_send_wqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe) 561 { 562 struct rxe_cqe cqe = {}; 563 struct ib_wc *wc = &cqe.ibwc; 564 struct ib_uverbs_wc *uwc = &cqe.uibwc; 565 int err; 566 567 if (qp->is_user) { 568 uwc->wr_id = wqe->wr.wr_id; 569 uwc->status = IB_WC_WR_FLUSH_ERR; 570 uwc->qp_num = qp->ibqp.qp_num; 571 } else { 572 wc->wr_id = wqe->wr.wr_id; 573 wc->status = IB_WC_WR_FLUSH_ERR; 574 wc->qp = &qp->ibqp; 575 } 576 577 err = rxe_cq_post(qp->scq, &cqe, 0); 578 if (err) 579 rxe_dbg_cq(qp->scq, "post cq failed, err = %d\n", err); 580 581 return err; 582 } 583 584 /* drain and optionally complete the send queue 585 * if unable to complete a wqe, i.e. cq is full, stop 586 * completing and flush the remaining wqes 587 */ 588 static void flush_send_queue(struct rxe_qp *qp, bool notify) 589 { 590 struct rxe_send_wqe *wqe; 591 struct rxe_queue *q = qp->sq.queue; 592 int err; 593 594 /* send queue never got created. nothing to do. */ 595 if (!qp->sq.queue) 596 return; 597 598 while ((wqe = queue_head(q, q->type))) { 599 if (notify) { 600 err = flush_send_wqe(qp, wqe); 601 if (err) 602 notify = 0; 603 } 604 queue_advance_consumer(q, q->type); 605 } 606 } 607 608 static void free_pkt(struct rxe_pkt_info *pkt) 609 { 610 struct sk_buff *skb = PKT_TO_SKB(pkt); 611 struct rxe_qp *qp = pkt->qp; 612 struct ib_device *dev = qp->ibqp.device; 613 614 kfree_skb(skb); 615 rxe_put(qp); 616 ib_device_put(dev); 617 } 618 619 /* reset the retry timer if 620 * - QP is type RC 621 * - there is a packet sent by the requester that 622 * might be acked (we still might get spurious 623 * timeouts but try to keep them as few as possible) 624 * - the timeout parameter is set 625 * - the QP is alive 626 */ 627 static void reset_retry_timer(struct rxe_qp *qp) 628 { 629 unsigned long flags; 630 631 if (qp_type(qp) == IB_QPT_RC && qp->qp_timeout_jiffies) { 632 spin_lock_irqsave(&qp->state_lock, flags); 633 if (qp_state(qp) >= IB_QPS_RTS && 634 psn_compare(qp->req.psn, qp->comp.psn) > 0) 635 mod_timer(&qp->retrans_timer, 636 jiffies + qp->qp_timeout_jiffies); 637 spin_unlock_irqrestore(&qp->state_lock, flags); 638 } 639 } 640 641 int rxe_completer(struct rxe_qp *qp) 642 { 643 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 644 struct rxe_send_wqe *wqe = NULL; 645 struct sk_buff *skb = NULL; 646 struct rxe_pkt_info *pkt = NULL; 647 enum comp_state state; 648 int ret; 649 unsigned long flags; 650 651 qp->req.again = 0; 652 653 spin_lock_irqsave(&qp->state_lock, flags); 654 if (!qp->valid || qp_state(qp) == IB_QPS_ERR || 655 qp_state(qp) == IB_QPS_RESET) { 656 bool notify = qp->valid && (qp_state(qp) == IB_QPS_ERR); 657 658 drain_resp_pkts(qp); 659 flush_send_queue(qp, notify); 660 spin_unlock_irqrestore(&qp->state_lock, flags); 661 goto exit; 662 } 663 spin_unlock_irqrestore(&qp->state_lock, flags); 664 665 if (qp->comp.timeout) { 666 qp->comp.timeout_retry = 1; 667 qp->comp.timeout = 0; 668 } else { 669 qp->comp.timeout_retry = 0; 670 } 671 672 if (qp->req.need_retry) 673 goto exit; 674 675 state = COMPST_GET_ACK; 676 677 while (1) { 678 rxe_dbg_qp(qp, "state = %s\n", comp_state_name[state]); 679 switch (state) { 680 case COMPST_GET_ACK: 681 skb = skb_dequeue(&qp->resp_pkts); 682 if (skb) { 683 pkt = SKB_TO_PKT(skb); 684 qp->comp.timeout_retry = 0; 685 } 686 state = COMPST_GET_WQE; 687 break; 688 689 case COMPST_GET_WQE: 690 state = get_wqe(qp, pkt, &wqe); 691 break; 692 693 case COMPST_CHECK_PSN: 694 state = check_psn(qp, pkt, wqe); 695 break; 696 697 case COMPST_CHECK_ACK: 698 state = check_ack(qp, pkt, wqe); 699 break; 700 701 case COMPST_READ: 702 state = do_read(qp, pkt, wqe); 703 break; 704 705 case COMPST_ATOMIC: 706 state = do_atomic(qp, pkt, wqe); 707 break; 708 709 case COMPST_WRITE_SEND: 710 if (wqe->state == wqe_state_pending && 711 wqe->last_psn == pkt->psn) 712 state = COMPST_COMP_ACK; 713 else 714 state = COMPST_UPDATE_COMP; 715 break; 716 717 case COMPST_COMP_ACK: 718 state = complete_ack(qp, pkt, wqe); 719 break; 720 721 case COMPST_COMP_WQE: 722 state = complete_wqe(qp, pkt, wqe); 723 break; 724 725 case COMPST_UPDATE_COMP: 726 if (pkt->mask & RXE_END_MASK) 727 qp->comp.opcode = -1; 728 else 729 qp->comp.opcode = pkt->opcode; 730 731 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 732 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; 733 734 if (qp->req.wait_psn) { 735 qp->req.wait_psn = 0; 736 qp->req.again = 1; 737 } 738 739 state = COMPST_DONE; 740 break; 741 742 case COMPST_DONE: 743 goto done; 744 745 case COMPST_EXIT: 746 if (qp->comp.timeout_retry && wqe) { 747 state = COMPST_ERROR_RETRY; 748 break; 749 } 750 751 reset_retry_timer(qp); 752 goto exit; 753 754 case COMPST_ERROR_RETRY: 755 /* we come here if the retry timer fired and we did 756 * not receive a response packet. try to retry the send 757 * queue if that makes sense and the limits have not 758 * been exceeded. remember that some timeouts are 759 * spurious since we do not reset the timer but kick 760 * it down the road or let it expire 761 */ 762 763 /* there is nothing to retry in this case */ 764 if (!wqe || (wqe->state == wqe_state_posted)) 765 goto exit; 766 767 /* if we've started a retry, don't start another 768 * retry sequence, unless this is a timeout. 769 */ 770 if (qp->comp.started_retry && 771 !qp->comp.timeout_retry) 772 goto done; 773 774 if (qp->comp.retry_cnt > 0) { 775 if (qp->comp.retry_cnt != 7) 776 qp->comp.retry_cnt--; 777 778 /* no point in retrying if we have already 779 * seen the last ack that the requester could 780 * have caused 781 */ 782 if (psn_compare(qp->req.psn, 783 qp->comp.psn) > 0) { 784 /* tell the requester to retry the 785 * send queue next time around 786 */ 787 rxe_counter_inc(rxe, 788 RXE_CNT_COMP_RETRY); 789 qp->req.need_retry = 1; 790 qp->comp.started_retry = 1; 791 qp->req.again = 1; 792 } 793 goto done; 794 795 } else { 796 rxe_counter_inc(rxe, RXE_CNT_RETRY_EXCEEDED); 797 wqe->status = IB_WC_RETRY_EXC_ERR; 798 state = COMPST_ERROR; 799 } 800 break; 801 802 case COMPST_RNR_RETRY: 803 /* we come here if we received an RNR NAK */ 804 if (qp->comp.rnr_retry > 0) { 805 if (qp->comp.rnr_retry != 7) 806 qp->comp.rnr_retry--; 807 808 /* don't start a retry flow until the 809 * rnr timer has fired 810 */ 811 qp->req.wait_for_rnr_timer = 1; 812 rxe_dbg_qp(qp, "set rnr nak timer\n"); 813 // TODO who protects from destroy_qp?? 814 mod_timer(&qp->rnr_nak_timer, 815 jiffies + rnrnak_jiffies(aeth_syn(pkt) 816 & ~AETH_TYPE_MASK)); 817 goto exit; 818 } else { 819 rxe_counter_inc(rxe, 820 RXE_CNT_RNR_RETRY_EXCEEDED); 821 wqe->status = IB_WC_RNR_RETRY_EXC_ERR; 822 state = COMPST_ERROR; 823 } 824 break; 825 826 case COMPST_ERROR: 827 WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS); 828 do_complete(qp, wqe); 829 rxe_qp_error(qp); 830 goto exit; 831 } 832 } 833 834 /* A non-zero return value will cause rxe_do_task to 835 * exit its loop and end the work item. A zero return 836 * will continue looping and return to rxe_completer 837 */ 838 done: 839 ret = 0; 840 goto out; 841 exit: 842 ret = (qp->req.again) ? 0 : -EAGAIN; 843 out: 844 qp->req.again = 0; 845 if (pkt) 846 free_pkt(pkt); 847 return ret; 848 } 849