1 /* 2 * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved. 3 * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved. 4 * 5 * This software is available to you under a choice of one of two 6 * licenses. You may choose to be licensed under the terms of the GNU 7 * General Public License (GPL) Version 2, available from the file 8 * COPYING in the main directory of this source tree, or the 9 * OpenIB.org BSD license below: 10 * 11 * Redistribution and use in source and binary forms, with or 12 * without modification, are permitted provided that the following 13 * conditions are met: 14 * 15 * - Redistributions of source code must retain the above 16 * copyright notice, this list of conditions and the following 17 * disclaimer. 18 * 19 * - Redistributions in binary form must reproduce the above 20 * copyright notice, this list of conditions and the following 21 * disclaimer in the documentation and/or other materials 22 * provided with the distribution. 23 * 24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 31 * SOFTWARE. 32 */ 33 34 #include <linux/skbuff.h> 35 36 #include "rxe.h" 37 #include "rxe_loc.h" 38 #include "rxe_queue.h" 39 #include "rxe_task.h" 40 41 enum comp_state { 42 COMPST_GET_ACK, 43 COMPST_GET_WQE, 44 COMPST_COMP_WQE, 45 COMPST_COMP_ACK, 46 COMPST_CHECK_PSN, 47 COMPST_CHECK_ACK, 48 COMPST_READ, 49 COMPST_ATOMIC, 50 COMPST_WRITE_SEND, 51 COMPST_UPDATE_COMP, 52 COMPST_ERROR_RETRY, 53 COMPST_RNR_RETRY, 54 COMPST_ERROR, 55 COMPST_EXIT, /* We have an issue, and we want to rerun the completer */ 56 COMPST_DONE, /* The completer finished successflly */ 57 }; 58 59 static char *comp_state_name[] = { 60 [COMPST_GET_ACK] = "GET ACK", 61 [COMPST_GET_WQE] = "GET WQE", 62 [COMPST_COMP_WQE] = "COMP WQE", 63 [COMPST_COMP_ACK] = "COMP ACK", 64 [COMPST_CHECK_PSN] = "CHECK PSN", 65 [COMPST_CHECK_ACK] = "CHECK ACK", 66 [COMPST_READ] = "READ", 67 [COMPST_ATOMIC] = "ATOMIC", 68 [COMPST_WRITE_SEND] = "WRITE/SEND", 69 [COMPST_UPDATE_COMP] = "UPDATE COMP", 70 [COMPST_ERROR_RETRY] = "ERROR RETRY", 71 [COMPST_RNR_RETRY] = "RNR RETRY", 72 [COMPST_ERROR] = "ERROR", 73 [COMPST_EXIT] = "EXIT", 74 [COMPST_DONE] = "DONE", 75 }; 76 77 static unsigned long rnrnak_usec[32] = { 78 [IB_RNR_TIMER_655_36] = 655360, 79 [IB_RNR_TIMER_000_01] = 10, 80 [IB_RNR_TIMER_000_02] = 20, 81 [IB_RNR_TIMER_000_03] = 30, 82 [IB_RNR_TIMER_000_04] = 40, 83 [IB_RNR_TIMER_000_06] = 60, 84 [IB_RNR_TIMER_000_08] = 80, 85 [IB_RNR_TIMER_000_12] = 120, 86 [IB_RNR_TIMER_000_16] = 160, 87 [IB_RNR_TIMER_000_24] = 240, 88 [IB_RNR_TIMER_000_32] = 320, 89 [IB_RNR_TIMER_000_48] = 480, 90 [IB_RNR_TIMER_000_64] = 640, 91 [IB_RNR_TIMER_000_96] = 960, 92 [IB_RNR_TIMER_001_28] = 1280, 93 [IB_RNR_TIMER_001_92] = 1920, 94 [IB_RNR_TIMER_002_56] = 2560, 95 [IB_RNR_TIMER_003_84] = 3840, 96 [IB_RNR_TIMER_005_12] = 5120, 97 [IB_RNR_TIMER_007_68] = 7680, 98 [IB_RNR_TIMER_010_24] = 10240, 99 [IB_RNR_TIMER_015_36] = 15360, 100 [IB_RNR_TIMER_020_48] = 20480, 101 [IB_RNR_TIMER_030_72] = 30720, 102 [IB_RNR_TIMER_040_96] = 40960, 103 [IB_RNR_TIMER_061_44] = 61410, 104 [IB_RNR_TIMER_081_92] = 81920, 105 [IB_RNR_TIMER_122_88] = 122880, 106 [IB_RNR_TIMER_163_84] = 163840, 107 [IB_RNR_TIMER_245_76] = 245760, 108 [IB_RNR_TIMER_327_68] = 327680, 109 [IB_RNR_TIMER_491_52] = 491520, 110 }; 111 112 static inline unsigned long rnrnak_jiffies(u8 timeout) 113 { 114 return max_t(unsigned long, 115 usecs_to_jiffies(rnrnak_usec[timeout]), 1); 116 } 117 118 static enum ib_wc_opcode wr_to_wc_opcode(enum ib_wr_opcode opcode) 119 { 120 switch (opcode) { 121 case IB_WR_RDMA_WRITE: return IB_WC_RDMA_WRITE; 122 case IB_WR_RDMA_WRITE_WITH_IMM: return IB_WC_RDMA_WRITE; 123 case IB_WR_SEND: return IB_WC_SEND; 124 case IB_WR_SEND_WITH_IMM: return IB_WC_SEND; 125 case IB_WR_RDMA_READ: return IB_WC_RDMA_READ; 126 case IB_WR_ATOMIC_CMP_AND_SWP: return IB_WC_COMP_SWAP; 127 case IB_WR_ATOMIC_FETCH_AND_ADD: return IB_WC_FETCH_ADD; 128 case IB_WR_LSO: return IB_WC_LSO; 129 case IB_WR_SEND_WITH_INV: return IB_WC_SEND; 130 case IB_WR_RDMA_READ_WITH_INV: return IB_WC_RDMA_READ; 131 case IB_WR_LOCAL_INV: return IB_WC_LOCAL_INV; 132 case IB_WR_REG_MR: return IB_WC_REG_MR; 133 134 default: 135 return 0xff; 136 } 137 } 138 139 void retransmit_timer(unsigned long data) 140 { 141 struct rxe_qp *qp = (struct rxe_qp *)data; 142 143 if (qp->valid) { 144 qp->comp.timeout = 1; 145 rxe_run_task(&qp->comp.task, 1); 146 } 147 } 148 149 void rxe_comp_queue_pkt(struct rxe_dev *rxe, struct rxe_qp *qp, 150 struct sk_buff *skb) 151 { 152 int must_sched; 153 154 skb_queue_tail(&qp->resp_pkts, skb); 155 156 must_sched = skb_queue_len(&qp->resp_pkts) > 1; 157 rxe_run_task(&qp->comp.task, must_sched); 158 } 159 160 static inline enum comp_state get_wqe(struct rxe_qp *qp, 161 struct rxe_pkt_info *pkt, 162 struct rxe_send_wqe **wqe_p) 163 { 164 struct rxe_send_wqe *wqe; 165 166 /* we come here whether or not we found a response packet to see if 167 * there are any posted WQEs 168 */ 169 wqe = queue_head(qp->sq.queue); 170 *wqe_p = wqe; 171 172 /* no WQE or requester has not started it yet */ 173 if (!wqe || wqe->state == wqe_state_posted) 174 return pkt ? COMPST_DONE : COMPST_EXIT; 175 176 /* WQE does not require an ack */ 177 if (wqe->state == wqe_state_done) 178 return COMPST_COMP_WQE; 179 180 /* WQE caused an error */ 181 if (wqe->state == wqe_state_error) 182 return COMPST_ERROR; 183 184 /* we have a WQE, if we also have an ack check its PSN */ 185 return pkt ? COMPST_CHECK_PSN : COMPST_EXIT; 186 } 187 188 static inline void reset_retry_counters(struct rxe_qp *qp) 189 { 190 qp->comp.retry_cnt = qp->attr.retry_cnt; 191 qp->comp.rnr_retry = qp->attr.rnr_retry; 192 } 193 194 static inline enum comp_state check_psn(struct rxe_qp *qp, 195 struct rxe_pkt_info *pkt, 196 struct rxe_send_wqe *wqe) 197 { 198 s32 diff; 199 200 /* check to see if response is past the oldest WQE. if it is, complete 201 * send/write or error read/atomic 202 */ 203 diff = psn_compare(pkt->psn, wqe->last_psn); 204 if (diff > 0) { 205 if (wqe->state == wqe_state_pending) { 206 if (wqe->mask & WR_ATOMIC_OR_READ_MASK) 207 return COMPST_ERROR_RETRY; 208 209 reset_retry_counters(qp); 210 return COMPST_COMP_WQE; 211 } else { 212 return COMPST_DONE; 213 } 214 } 215 216 /* compare response packet to expected response */ 217 diff = psn_compare(pkt->psn, qp->comp.psn); 218 if (diff < 0) { 219 /* response is most likely a retried packet if it matches an 220 * uncompleted WQE go complete it else ignore it 221 */ 222 if (pkt->psn == wqe->last_psn) 223 return COMPST_COMP_ACK; 224 else 225 return COMPST_DONE; 226 } else if ((diff > 0) && (wqe->mask & WR_ATOMIC_OR_READ_MASK)) { 227 return COMPST_DONE; 228 } else { 229 return COMPST_CHECK_ACK; 230 } 231 } 232 233 static inline enum comp_state check_ack(struct rxe_qp *qp, 234 struct rxe_pkt_info *pkt, 235 struct rxe_send_wqe *wqe) 236 { 237 unsigned int mask = pkt->mask; 238 u8 syn; 239 240 /* Check the sequence only */ 241 switch (qp->comp.opcode) { 242 case -1: 243 /* Will catch all *_ONLY cases. */ 244 if (!(mask & RXE_START_MASK)) 245 return COMPST_ERROR; 246 247 break; 248 249 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 250 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 251 if (pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE && 252 pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST) { 253 return COMPST_ERROR; 254 } 255 break; 256 default: 257 WARN_ON_ONCE(1); 258 } 259 260 /* Check operation validity. */ 261 switch (pkt->opcode) { 262 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 263 case IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST: 264 case IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY: 265 syn = aeth_syn(pkt); 266 267 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 268 return COMPST_ERROR; 269 270 /* Fall through (IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE 271 * doesn't have an AETH) 272 */ 273 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 274 if (wqe->wr.opcode != IB_WR_RDMA_READ && 275 wqe->wr.opcode != IB_WR_RDMA_READ_WITH_INV) { 276 return COMPST_ERROR; 277 } 278 reset_retry_counters(qp); 279 return COMPST_READ; 280 281 case IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE: 282 syn = aeth_syn(pkt); 283 284 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 285 return COMPST_ERROR; 286 287 if (wqe->wr.opcode != IB_WR_ATOMIC_CMP_AND_SWP && 288 wqe->wr.opcode != IB_WR_ATOMIC_FETCH_AND_ADD) 289 return COMPST_ERROR; 290 reset_retry_counters(qp); 291 return COMPST_ATOMIC; 292 293 case IB_OPCODE_RC_ACKNOWLEDGE: 294 syn = aeth_syn(pkt); 295 switch (syn & AETH_TYPE_MASK) { 296 case AETH_ACK: 297 reset_retry_counters(qp); 298 return COMPST_WRITE_SEND; 299 300 case AETH_RNR_NAK: 301 return COMPST_RNR_RETRY; 302 303 case AETH_NAK: 304 switch (syn) { 305 case AETH_NAK_PSN_SEQ_ERROR: 306 /* a nak implicitly acks all packets with psns 307 * before 308 */ 309 if (psn_compare(pkt->psn, qp->comp.psn) > 0) { 310 qp->comp.psn = pkt->psn; 311 if (qp->req.wait_psn) { 312 qp->req.wait_psn = 0; 313 rxe_run_task(&qp->req.task, 1); 314 } 315 } 316 return COMPST_ERROR_RETRY; 317 318 case AETH_NAK_INVALID_REQ: 319 wqe->status = IB_WC_REM_INV_REQ_ERR; 320 return COMPST_ERROR; 321 322 case AETH_NAK_REM_ACC_ERR: 323 wqe->status = IB_WC_REM_ACCESS_ERR; 324 return COMPST_ERROR; 325 326 case AETH_NAK_REM_OP_ERR: 327 wqe->status = IB_WC_REM_OP_ERR; 328 return COMPST_ERROR; 329 330 default: 331 pr_warn("unexpected nak %x\n", syn); 332 wqe->status = IB_WC_REM_OP_ERR; 333 return COMPST_ERROR; 334 } 335 336 default: 337 return COMPST_ERROR; 338 } 339 break; 340 341 default: 342 pr_warn("unexpected opcode\n"); 343 } 344 345 return COMPST_ERROR; 346 } 347 348 static inline enum comp_state do_read(struct rxe_qp *qp, 349 struct rxe_pkt_info *pkt, 350 struct rxe_send_wqe *wqe) 351 { 352 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 353 int ret; 354 355 ret = copy_data(rxe, qp->pd, IB_ACCESS_LOCAL_WRITE, 356 &wqe->dma, payload_addr(pkt), 357 payload_size(pkt), to_mem_obj, NULL); 358 if (ret) 359 return COMPST_ERROR; 360 361 if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK)) 362 return COMPST_COMP_ACK; 363 else 364 return COMPST_UPDATE_COMP; 365 } 366 367 static inline enum comp_state do_atomic(struct rxe_qp *qp, 368 struct rxe_pkt_info *pkt, 369 struct rxe_send_wqe *wqe) 370 { 371 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 372 int ret; 373 374 u64 atomic_orig = atmack_orig(pkt); 375 376 ret = copy_data(rxe, qp->pd, IB_ACCESS_LOCAL_WRITE, 377 &wqe->dma, &atomic_orig, 378 sizeof(u64), to_mem_obj, NULL); 379 if (ret) 380 return COMPST_ERROR; 381 else 382 return COMPST_COMP_ACK; 383 } 384 385 static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe, 386 struct rxe_cqe *cqe) 387 { 388 memset(cqe, 0, sizeof(*cqe)); 389 390 if (!qp->is_user) { 391 struct ib_wc *wc = &cqe->ibwc; 392 393 wc->wr_id = wqe->wr.wr_id; 394 wc->status = wqe->status; 395 wc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 396 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 397 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 398 wc->wc_flags = IB_WC_WITH_IMM; 399 wc->byte_len = wqe->dma.length; 400 wc->qp = &qp->ibqp; 401 } else { 402 struct ib_uverbs_wc *uwc = &cqe->uibwc; 403 404 uwc->wr_id = wqe->wr.wr_id; 405 uwc->status = wqe->status; 406 uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 407 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 408 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 409 uwc->wc_flags = IB_WC_WITH_IMM; 410 uwc->byte_len = wqe->dma.length; 411 uwc->qp_num = qp->ibqp.qp_num; 412 } 413 } 414 415 /* 416 * IBA Spec. Section 10.7.3.1 SIGNALED COMPLETIONS 417 * ---------8<---------8<------------- 418 * ...Note that if a completion error occurs, a Work Completion 419 * will always be generated, even if the signaling 420 * indicator requests an Unsignaled Completion. 421 * ---------8<---------8<------------- 422 */ 423 static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe) 424 { 425 struct rxe_cqe cqe; 426 427 if ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) || 428 (wqe->wr.send_flags & IB_SEND_SIGNALED) || 429 wqe->status != IB_WC_SUCCESS) { 430 make_send_cqe(qp, wqe, &cqe); 431 advance_consumer(qp->sq.queue); 432 rxe_cq_post(qp->scq, &cqe, 0); 433 } else { 434 advance_consumer(qp->sq.queue); 435 } 436 437 /* 438 * we completed something so let req run again 439 * if it is trying to fence 440 */ 441 if (qp->req.wait_fence) { 442 qp->req.wait_fence = 0; 443 rxe_run_task(&qp->req.task, 1); 444 } 445 } 446 447 static inline enum comp_state complete_ack(struct rxe_qp *qp, 448 struct rxe_pkt_info *pkt, 449 struct rxe_send_wqe *wqe) 450 { 451 unsigned long flags; 452 453 if (wqe->has_rd_atomic) { 454 wqe->has_rd_atomic = 0; 455 atomic_inc(&qp->req.rd_atomic); 456 if (qp->req.need_rd_atomic) { 457 qp->comp.timeout_retry = 0; 458 qp->req.need_rd_atomic = 0; 459 rxe_run_task(&qp->req.task, 1); 460 } 461 } 462 463 if (unlikely(qp->req.state == QP_STATE_DRAIN)) { 464 /* state_lock used by requester & completer */ 465 spin_lock_irqsave(&qp->state_lock, flags); 466 if ((qp->req.state == QP_STATE_DRAIN) && 467 (qp->comp.psn == qp->req.psn)) { 468 qp->req.state = QP_STATE_DRAINED; 469 spin_unlock_irqrestore(&qp->state_lock, flags); 470 471 if (qp->ibqp.event_handler) { 472 struct ib_event ev; 473 474 ev.device = qp->ibqp.device; 475 ev.element.qp = &qp->ibqp; 476 ev.event = IB_EVENT_SQ_DRAINED; 477 qp->ibqp.event_handler(&ev, 478 qp->ibqp.qp_context); 479 } 480 } else { 481 spin_unlock_irqrestore(&qp->state_lock, flags); 482 } 483 } 484 485 do_complete(qp, wqe); 486 487 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 488 return COMPST_UPDATE_COMP; 489 else 490 return COMPST_DONE; 491 } 492 493 static inline enum comp_state complete_wqe(struct rxe_qp *qp, 494 struct rxe_pkt_info *pkt, 495 struct rxe_send_wqe *wqe) 496 { 497 qp->comp.opcode = -1; 498 499 if (pkt) { 500 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 501 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; 502 503 if (qp->req.wait_psn) { 504 qp->req.wait_psn = 0; 505 rxe_run_task(&qp->req.task, 1); 506 } 507 } 508 509 do_complete(qp, wqe); 510 511 return COMPST_GET_WQE; 512 } 513 514 static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify) 515 { 516 struct sk_buff *skb; 517 struct rxe_send_wqe *wqe; 518 519 while ((skb = skb_dequeue(&qp->resp_pkts))) { 520 rxe_drop_ref(qp); 521 kfree_skb(skb); 522 } 523 524 while ((wqe = queue_head(qp->sq.queue))) { 525 if (notify) { 526 wqe->status = IB_WC_WR_FLUSH_ERR; 527 do_complete(qp, wqe); 528 } else { 529 advance_consumer(qp->sq.queue); 530 } 531 } 532 } 533 534 int rxe_completer(void *arg) 535 { 536 struct rxe_qp *qp = (struct rxe_qp *)arg; 537 struct rxe_send_wqe *wqe = wqe; 538 struct sk_buff *skb = NULL; 539 struct rxe_pkt_info *pkt = NULL; 540 enum comp_state state; 541 542 rxe_add_ref(qp); 543 544 if (!qp->valid || qp->req.state == QP_STATE_ERROR || 545 qp->req.state == QP_STATE_RESET) { 546 rxe_drain_resp_pkts(qp, qp->valid && 547 qp->req.state == QP_STATE_ERROR); 548 goto exit; 549 } 550 551 if (qp->comp.timeout) { 552 qp->comp.timeout_retry = 1; 553 qp->comp.timeout = 0; 554 } else { 555 qp->comp.timeout_retry = 0; 556 } 557 558 if (qp->req.need_retry) 559 goto exit; 560 561 state = COMPST_GET_ACK; 562 563 while (1) { 564 pr_debug("qp#%d state = %s\n", qp_num(qp), 565 comp_state_name[state]); 566 switch (state) { 567 case COMPST_GET_ACK: 568 skb = skb_dequeue(&qp->resp_pkts); 569 if (skb) { 570 pkt = SKB_TO_PKT(skb); 571 qp->comp.timeout_retry = 0; 572 } 573 state = COMPST_GET_WQE; 574 break; 575 576 case COMPST_GET_WQE: 577 state = get_wqe(qp, pkt, &wqe); 578 break; 579 580 case COMPST_CHECK_PSN: 581 state = check_psn(qp, pkt, wqe); 582 break; 583 584 case COMPST_CHECK_ACK: 585 state = check_ack(qp, pkt, wqe); 586 break; 587 588 case COMPST_READ: 589 state = do_read(qp, pkt, wqe); 590 break; 591 592 case COMPST_ATOMIC: 593 state = do_atomic(qp, pkt, wqe); 594 break; 595 596 case COMPST_WRITE_SEND: 597 if (wqe->state == wqe_state_pending && 598 wqe->last_psn == pkt->psn) 599 state = COMPST_COMP_ACK; 600 else 601 state = COMPST_UPDATE_COMP; 602 break; 603 604 case COMPST_COMP_ACK: 605 state = complete_ack(qp, pkt, wqe); 606 break; 607 608 case COMPST_COMP_WQE: 609 state = complete_wqe(qp, pkt, wqe); 610 break; 611 612 case COMPST_UPDATE_COMP: 613 if (pkt->mask & RXE_END_MASK) 614 qp->comp.opcode = -1; 615 else 616 qp->comp.opcode = pkt->opcode; 617 618 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 619 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; 620 621 if (qp->req.wait_psn) { 622 qp->req.wait_psn = 0; 623 rxe_run_task(&qp->req.task, 1); 624 } 625 626 state = COMPST_DONE; 627 break; 628 629 case COMPST_DONE: 630 if (pkt) { 631 rxe_drop_ref(pkt->qp); 632 kfree_skb(skb); 633 skb = NULL; 634 } 635 goto done; 636 637 case COMPST_EXIT: 638 if (qp->comp.timeout_retry && wqe) { 639 state = COMPST_ERROR_RETRY; 640 break; 641 } 642 643 /* re reset the timeout counter if 644 * (1) QP is type RC 645 * (2) the QP is alive 646 * (3) there is a packet sent by the requester that 647 * might be acked (we still might get spurious 648 * timeouts but try to keep them as few as possible) 649 * (4) the timeout parameter is set 650 */ 651 if ((qp_type(qp) == IB_QPT_RC) && 652 (qp->req.state == QP_STATE_READY) && 653 (psn_compare(qp->req.psn, qp->comp.psn) > 0) && 654 qp->qp_timeout_jiffies) 655 mod_timer(&qp->retrans_timer, 656 jiffies + qp->qp_timeout_jiffies); 657 WARN_ON_ONCE(skb); 658 goto exit; 659 660 case COMPST_ERROR_RETRY: 661 /* we come here if the retry timer fired and we did 662 * not receive a response packet. try to retry the send 663 * queue if that makes sense and the limits have not 664 * been exceeded. remember that some timeouts are 665 * spurious since we do not reset the timer but kick 666 * it down the road or let it expire 667 */ 668 669 /* there is nothing to retry in this case */ 670 if (!wqe || (wqe->state == wqe_state_posted)) { 671 WARN_ON_ONCE(skb); 672 goto exit; 673 } 674 675 if (qp->comp.retry_cnt > 0) { 676 if (qp->comp.retry_cnt != 7) 677 qp->comp.retry_cnt--; 678 679 /* no point in retrying if we have already 680 * seen the last ack that the requester could 681 * have caused 682 */ 683 if (psn_compare(qp->req.psn, 684 qp->comp.psn) > 0) { 685 /* tell the requester to retry the 686 * send send queue next time around 687 */ 688 qp->req.need_retry = 1; 689 rxe_run_task(&qp->req.task, 1); 690 } 691 692 if (pkt) { 693 rxe_drop_ref(pkt->qp); 694 kfree_skb(skb); 695 skb = NULL; 696 } 697 698 WARN_ON_ONCE(skb); 699 goto exit; 700 701 } else { 702 wqe->status = IB_WC_RETRY_EXC_ERR; 703 state = COMPST_ERROR; 704 } 705 break; 706 707 case COMPST_RNR_RETRY: 708 if (qp->comp.rnr_retry > 0) { 709 if (qp->comp.rnr_retry != 7) 710 qp->comp.rnr_retry--; 711 712 qp->req.need_retry = 1; 713 pr_debug("qp#%d set rnr nak timer\n", 714 qp_num(qp)); 715 mod_timer(&qp->rnr_nak_timer, 716 jiffies + rnrnak_jiffies(aeth_syn(pkt) 717 & ~AETH_TYPE_MASK)); 718 rxe_drop_ref(pkt->qp); 719 kfree_skb(skb); 720 skb = NULL; 721 goto exit; 722 } else { 723 wqe->status = IB_WC_RNR_RETRY_EXC_ERR; 724 state = COMPST_ERROR; 725 } 726 break; 727 728 case COMPST_ERROR: 729 WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS); 730 do_complete(qp, wqe); 731 rxe_qp_error(qp); 732 733 if (pkt) { 734 rxe_drop_ref(pkt->qp); 735 kfree_skb(skb); 736 skb = NULL; 737 } 738 739 WARN_ON_ONCE(skb); 740 goto exit; 741 } 742 } 743 744 exit: 745 /* we come here if we are done with processing and want the task to 746 * exit from the loop calling us 747 */ 748 WARN_ON_ONCE(skb); 749 rxe_drop_ref(qp); 750 return -EAGAIN; 751 752 done: 753 /* we come here if we have processed a packet we want the task to call 754 * us again to see if there is anything else to do 755 */ 756 WARN_ON_ONCE(skb); 757 rxe_drop_ref(qp); 758 return 0; 759 } 760