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