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(struct timer_list *t) 140 { 141 struct rxe_qp *qp = from_timer(qp, t, retrans_timer); 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 if (must_sched != 0) 158 rxe_counter_inc(rxe, RXE_CNT_COMPLETER_SCHED); 159 rxe_run_task(&qp->comp.task, must_sched); 160 } 161 162 static inline enum comp_state get_wqe(struct rxe_qp *qp, 163 struct rxe_pkt_info *pkt, 164 struct rxe_send_wqe **wqe_p) 165 { 166 struct rxe_send_wqe *wqe; 167 168 /* we come here whether or not we found a response packet to see if 169 * there are any posted WQEs 170 */ 171 wqe = queue_head(qp->sq.queue); 172 *wqe_p = wqe; 173 174 /* no WQE or requester has not started it yet */ 175 if (!wqe || wqe->state == wqe_state_posted) 176 return pkt ? COMPST_DONE : COMPST_EXIT; 177 178 /* WQE does not require an ack */ 179 if (wqe->state == wqe_state_done) 180 return COMPST_COMP_WQE; 181 182 /* WQE caused an error */ 183 if (wqe->state == wqe_state_error) 184 return COMPST_ERROR; 185 186 /* we have a WQE, if we also have an ack check its PSN */ 187 return pkt ? COMPST_CHECK_PSN : COMPST_EXIT; 188 } 189 190 static inline void reset_retry_counters(struct rxe_qp *qp) 191 { 192 qp->comp.retry_cnt = qp->attr.retry_cnt; 193 qp->comp.rnr_retry = qp->attr.rnr_retry; 194 } 195 196 static inline enum comp_state check_psn(struct rxe_qp *qp, 197 struct rxe_pkt_info *pkt, 198 struct rxe_send_wqe *wqe) 199 { 200 s32 diff; 201 202 /* check to see if response is past the oldest WQE. if it is, complete 203 * send/write or error read/atomic 204 */ 205 diff = psn_compare(pkt->psn, wqe->last_psn); 206 if (diff > 0) { 207 if (wqe->state == wqe_state_pending) { 208 if (wqe->mask & WR_ATOMIC_OR_READ_MASK) 209 return COMPST_ERROR_RETRY; 210 211 reset_retry_counters(qp); 212 return COMPST_COMP_WQE; 213 } else { 214 return COMPST_DONE; 215 } 216 } 217 218 /* compare response packet to expected response */ 219 diff = psn_compare(pkt->psn, qp->comp.psn); 220 if (diff < 0) { 221 /* response is most likely a retried packet if it matches an 222 * uncompleted WQE go complete it else ignore it 223 */ 224 if (pkt->psn == wqe->last_psn) 225 return COMPST_COMP_ACK; 226 else 227 return COMPST_DONE; 228 } else if ((diff > 0) && (wqe->mask & WR_ATOMIC_OR_READ_MASK)) { 229 return COMPST_DONE; 230 } else { 231 return COMPST_CHECK_ACK; 232 } 233 } 234 235 static inline enum comp_state check_ack(struct rxe_qp *qp, 236 struct rxe_pkt_info *pkt, 237 struct rxe_send_wqe *wqe) 238 { 239 unsigned int mask = pkt->mask; 240 u8 syn; 241 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 242 243 /* Check the sequence only */ 244 switch (qp->comp.opcode) { 245 case -1: 246 /* Will catch all *_ONLY cases. */ 247 if (!(mask & RXE_START_MASK)) 248 return COMPST_ERROR; 249 250 break; 251 252 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 253 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 254 if (pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE && 255 pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST) { 256 return COMPST_ERROR; 257 } 258 break; 259 default: 260 WARN_ON_ONCE(1); 261 } 262 263 /* Check operation validity. */ 264 switch (pkt->opcode) { 265 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: 266 case IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST: 267 case IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY: 268 syn = aeth_syn(pkt); 269 270 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 271 return COMPST_ERROR; 272 273 /* fall through */ 274 /* (IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE doesn't have an AETH) 275 */ 276 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: 277 if (wqe->wr.opcode != IB_WR_RDMA_READ && 278 wqe->wr.opcode != IB_WR_RDMA_READ_WITH_INV) { 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 rxe_run_task(&qp->req.task, 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 pr_warn("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 pr_warn("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), to_mem_obj, NULL); 363 if (ret) 364 return COMPST_ERROR; 365 366 if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK)) 367 return COMPST_COMP_ACK; 368 else 369 return COMPST_UPDATE_COMP; 370 } 371 372 static inline enum comp_state do_atomic(struct rxe_qp *qp, 373 struct rxe_pkt_info *pkt, 374 struct rxe_send_wqe *wqe) 375 { 376 int ret; 377 378 u64 atomic_orig = atmack_orig(pkt); 379 380 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, 381 &wqe->dma, &atomic_orig, 382 sizeof(u64), to_mem_obj, NULL); 383 if (ret) 384 return COMPST_ERROR; 385 else 386 return COMPST_COMP_ACK; 387 } 388 389 static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe, 390 struct rxe_cqe *cqe) 391 { 392 memset(cqe, 0, sizeof(*cqe)); 393 394 if (!qp->is_user) { 395 struct ib_wc *wc = &cqe->ibwc; 396 397 wc->wr_id = wqe->wr.wr_id; 398 wc->status = wqe->status; 399 wc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 400 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 401 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 402 wc->wc_flags = IB_WC_WITH_IMM; 403 wc->byte_len = wqe->dma.length; 404 wc->qp = &qp->ibqp; 405 } else { 406 struct ib_uverbs_wc *uwc = &cqe->uibwc; 407 408 uwc->wr_id = wqe->wr.wr_id; 409 uwc->status = wqe->status; 410 uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 411 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 412 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 413 uwc->wc_flags = IB_WC_WITH_IMM; 414 uwc->byte_len = wqe->dma.length; 415 uwc->qp_num = qp->ibqp.qp_num; 416 } 417 } 418 419 /* 420 * IBA Spec. Section 10.7.3.1 SIGNALED COMPLETIONS 421 * ---------8<---------8<------------- 422 * ...Note that if a completion error occurs, a Work Completion 423 * will always be generated, even if the signaling 424 * indicator requests an Unsignaled Completion. 425 * ---------8<---------8<------------- 426 */ 427 static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe) 428 { 429 struct rxe_cqe cqe; 430 431 if ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) || 432 (wqe->wr.send_flags & IB_SEND_SIGNALED) || 433 wqe->status != IB_WC_SUCCESS) { 434 make_send_cqe(qp, wqe, &cqe); 435 advance_consumer(qp->sq.queue); 436 rxe_cq_post(qp->scq, &cqe, 0); 437 } else { 438 advance_consumer(qp->sq.queue); 439 } 440 441 /* 442 * we completed something so let req run again 443 * if it is trying to fence 444 */ 445 if (qp->req.wait_fence) { 446 qp->req.wait_fence = 0; 447 rxe_run_task(&qp->req.task, 1); 448 } 449 } 450 451 static inline enum comp_state complete_ack(struct rxe_qp *qp, 452 struct rxe_pkt_info *pkt, 453 struct rxe_send_wqe *wqe) 454 { 455 unsigned long flags; 456 457 if (wqe->has_rd_atomic) { 458 wqe->has_rd_atomic = 0; 459 atomic_inc(&qp->req.rd_atomic); 460 if (qp->req.need_rd_atomic) { 461 qp->comp.timeout_retry = 0; 462 qp->req.need_rd_atomic = 0; 463 rxe_run_task(&qp->req.task, 1); 464 } 465 } 466 467 if (unlikely(qp->req.state == QP_STATE_DRAIN)) { 468 /* state_lock used by requester & completer */ 469 spin_lock_irqsave(&qp->state_lock, flags); 470 if ((qp->req.state == QP_STATE_DRAIN) && 471 (qp->comp.psn == qp->req.psn)) { 472 qp->req.state = QP_STATE_DRAINED; 473 spin_unlock_irqrestore(&qp->state_lock, flags); 474 475 if (qp->ibqp.event_handler) { 476 struct ib_event ev; 477 478 ev.device = qp->ibqp.device; 479 ev.element.qp = &qp->ibqp; 480 ev.event = IB_EVENT_SQ_DRAINED; 481 qp->ibqp.event_handler(&ev, 482 qp->ibqp.qp_context); 483 } 484 } else { 485 spin_unlock_irqrestore(&qp->state_lock, flags); 486 } 487 } 488 489 do_complete(qp, wqe); 490 491 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 492 return COMPST_UPDATE_COMP; 493 else 494 return COMPST_DONE; 495 } 496 497 static inline enum comp_state complete_wqe(struct rxe_qp *qp, 498 struct rxe_pkt_info *pkt, 499 struct rxe_send_wqe *wqe) 500 { 501 qp->comp.opcode = -1; 502 503 if (pkt) { 504 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 505 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; 506 507 if (qp->req.wait_psn) { 508 qp->req.wait_psn = 0; 509 rxe_run_task(&qp->req.task, 1); 510 } 511 } 512 513 do_complete(qp, wqe); 514 515 return COMPST_GET_WQE; 516 } 517 518 static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify) 519 { 520 struct sk_buff *skb; 521 struct rxe_send_wqe *wqe; 522 523 while ((skb = skb_dequeue(&qp->resp_pkts))) { 524 rxe_drop_ref(qp); 525 kfree_skb(skb); 526 } 527 528 while ((wqe = queue_head(qp->sq.queue))) { 529 if (notify) { 530 wqe->status = IB_WC_WR_FLUSH_ERR; 531 do_complete(qp, wqe); 532 } else { 533 advance_consumer(qp->sq.queue); 534 } 535 } 536 } 537 538 int rxe_completer(void *arg) 539 { 540 struct rxe_qp *qp = (struct rxe_qp *)arg; 541 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 542 struct rxe_send_wqe *wqe = wqe; 543 struct sk_buff *skb = NULL; 544 struct rxe_pkt_info *pkt = NULL; 545 enum comp_state state; 546 547 rxe_add_ref(qp); 548 549 if (!qp->valid || qp->req.state == QP_STATE_ERROR || 550 qp->req.state == QP_STATE_RESET) { 551 rxe_drain_resp_pkts(qp, qp->valid && 552 qp->req.state == QP_STATE_ERROR); 553 goto exit; 554 } 555 556 if (qp->comp.timeout) { 557 qp->comp.timeout_retry = 1; 558 qp->comp.timeout = 0; 559 } else { 560 qp->comp.timeout_retry = 0; 561 } 562 563 if (qp->req.need_retry) 564 goto exit; 565 566 state = COMPST_GET_ACK; 567 568 while (1) { 569 pr_debug("qp#%d state = %s\n", qp_num(qp), 570 comp_state_name[state]); 571 switch (state) { 572 case COMPST_GET_ACK: 573 skb = skb_dequeue(&qp->resp_pkts); 574 if (skb) { 575 pkt = SKB_TO_PKT(skb); 576 qp->comp.timeout_retry = 0; 577 } 578 state = COMPST_GET_WQE; 579 break; 580 581 case COMPST_GET_WQE: 582 state = get_wqe(qp, pkt, &wqe); 583 break; 584 585 case COMPST_CHECK_PSN: 586 state = check_psn(qp, pkt, wqe); 587 break; 588 589 case COMPST_CHECK_ACK: 590 state = check_ack(qp, pkt, wqe); 591 break; 592 593 case COMPST_READ: 594 state = do_read(qp, pkt, wqe); 595 break; 596 597 case COMPST_ATOMIC: 598 state = do_atomic(qp, pkt, wqe); 599 break; 600 601 case COMPST_WRITE_SEND: 602 if (wqe->state == wqe_state_pending && 603 wqe->last_psn == pkt->psn) 604 state = COMPST_COMP_ACK; 605 else 606 state = COMPST_UPDATE_COMP; 607 break; 608 609 case COMPST_COMP_ACK: 610 state = complete_ack(qp, pkt, wqe); 611 break; 612 613 case COMPST_COMP_WQE: 614 state = complete_wqe(qp, pkt, wqe); 615 break; 616 617 case COMPST_UPDATE_COMP: 618 if (pkt->mask & RXE_END_MASK) 619 qp->comp.opcode = -1; 620 else 621 qp->comp.opcode = pkt->opcode; 622 623 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 624 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; 625 626 if (qp->req.wait_psn) { 627 qp->req.wait_psn = 0; 628 rxe_run_task(&qp->req.task, 1); 629 } 630 631 state = COMPST_DONE; 632 break; 633 634 case COMPST_DONE: 635 if (pkt) { 636 rxe_drop_ref(pkt->qp); 637 kfree_skb(skb); 638 skb = NULL; 639 } 640 goto done; 641 642 case COMPST_EXIT: 643 if (qp->comp.timeout_retry && wqe) { 644 state = COMPST_ERROR_RETRY; 645 break; 646 } 647 648 /* re reset the timeout counter if 649 * (1) QP is type RC 650 * (2) the QP is alive 651 * (3) there is a packet sent by the requester that 652 * might be acked (we still might get spurious 653 * timeouts but try to keep them as few as possible) 654 * (4) the timeout parameter is set 655 */ 656 if ((qp_type(qp) == IB_QPT_RC) && 657 (qp->req.state == QP_STATE_READY) && 658 (psn_compare(qp->req.psn, qp->comp.psn) > 0) && 659 qp->qp_timeout_jiffies) 660 mod_timer(&qp->retrans_timer, 661 jiffies + qp->qp_timeout_jiffies); 662 goto exit; 663 664 case COMPST_ERROR_RETRY: 665 /* we come here if the retry timer fired and we did 666 * not receive a response packet. try to retry the send 667 * queue if that makes sense and the limits have not 668 * been exceeded. remember that some timeouts are 669 * spurious since we do not reset the timer but kick 670 * it down the road or let it expire 671 */ 672 673 /* there is nothing to retry in this case */ 674 if (!wqe || (wqe->state == wqe_state_posted)) { 675 goto exit; 676 } 677 678 if (qp->comp.retry_cnt > 0) { 679 if (qp->comp.retry_cnt != 7) 680 qp->comp.retry_cnt--; 681 682 /* no point in retrying if we have already 683 * seen the last ack that the requester could 684 * have caused 685 */ 686 if (psn_compare(qp->req.psn, 687 qp->comp.psn) > 0) { 688 /* tell the requester to retry the 689 * send queue next time around 690 */ 691 rxe_counter_inc(rxe, 692 RXE_CNT_COMP_RETRY); 693 qp->req.need_retry = 1; 694 rxe_run_task(&qp->req.task, 1); 695 } 696 697 if (pkt) { 698 rxe_drop_ref(pkt->qp); 699 kfree_skb(skb); 700 skb = NULL; 701 } 702 703 goto exit; 704 705 } else { 706 rxe_counter_inc(rxe, RXE_CNT_RETRY_EXCEEDED); 707 wqe->status = IB_WC_RETRY_EXC_ERR; 708 state = COMPST_ERROR; 709 } 710 break; 711 712 case COMPST_RNR_RETRY: 713 if (qp->comp.rnr_retry > 0) { 714 if (qp->comp.rnr_retry != 7) 715 qp->comp.rnr_retry--; 716 717 qp->req.need_retry = 1; 718 pr_debug("qp#%d set rnr nak timer\n", 719 qp_num(qp)); 720 mod_timer(&qp->rnr_nak_timer, 721 jiffies + rnrnak_jiffies(aeth_syn(pkt) 722 & ~AETH_TYPE_MASK)); 723 rxe_drop_ref(pkt->qp); 724 kfree_skb(skb); 725 skb = NULL; 726 goto exit; 727 } else { 728 rxe_counter_inc(rxe, 729 RXE_CNT_RNR_RETRY_EXCEEDED); 730 wqe->status = IB_WC_RNR_RETRY_EXC_ERR; 731 state = COMPST_ERROR; 732 } 733 break; 734 735 case COMPST_ERROR: 736 WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS); 737 do_complete(qp, wqe); 738 rxe_qp_error(qp); 739 740 if (pkt) { 741 rxe_drop_ref(pkt->qp); 742 kfree_skb(skb); 743 skb = NULL; 744 } 745 746 goto exit; 747 } 748 } 749 750 exit: 751 /* we come here if we are done with processing and want the task to 752 * exit from the loop calling us 753 */ 754 WARN_ON_ONCE(skb); 755 rxe_drop_ref(qp); 756 return -EAGAIN; 757 758 done: 759 /* we come here if we have processed a packet we want the task to call 760 * us again to see if there is anything else to do 761 */ 762 WARN_ON_ONCE(skb); 763 rxe_drop_ref(qp); 764 return 0; 765 } 766