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 wqe->status = IB_WC_FATAL_ERR; 280 return COMPST_ERROR; 281 } 282 reset_retry_counters(qp); 283 return COMPST_READ; 284 285 case IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE: 286 syn = aeth_syn(pkt); 287 288 if ((syn & AETH_TYPE_MASK) != AETH_ACK) 289 return COMPST_ERROR; 290 291 if (wqe->wr.opcode != IB_WR_ATOMIC_CMP_AND_SWP && 292 wqe->wr.opcode != IB_WR_ATOMIC_FETCH_AND_ADD) 293 return COMPST_ERROR; 294 reset_retry_counters(qp); 295 return COMPST_ATOMIC; 296 297 case IB_OPCODE_RC_ACKNOWLEDGE: 298 syn = aeth_syn(pkt); 299 switch (syn & AETH_TYPE_MASK) { 300 case AETH_ACK: 301 reset_retry_counters(qp); 302 return COMPST_WRITE_SEND; 303 304 case AETH_RNR_NAK: 305 rxe_counter_inc(rxe, RXE_CNT_RCV_RNR); 306 return COMPST_RNR_RETRY; 307 308 case AETH_NAK: 309 switch (syn) { 310 case AETH_NAK_PSN_SEQ_ERROR: 311 /* a nak implicitly acks all packets with psns 312 * before 313 */ 314 if (psn_compare(pkt->psn, qp->comp.psn) > 0) { 315 rxe_counter_inc(rxe, 316 RXE_CNT_RCV_SEQ_ERR); 317 qp->comp.psn = pkt->psn; 318 if (qp->req.wait_psn) { 319 qp->req.wait_psn = 0; 320 rxe_run_task(&qp->req.task, 1); 321 } 322 } 323 return COMPST_ERROR_RETRY; 324 325 case AETH_NAK_INVALID_REQ: 326 wqe->status = IB_WC_REM_INV_REQ_ERR; 327 return COMPST_ERROR; 328 329 case AETH_NAK_REM_ACC_ERR: 330 wqe->status = IB_WC_REM_ACCESS_ERR; 331 return COMPST_ERROR; 332 333 case AETH_NAK_REM_OP_ERR: 334 wqe->status = IB_WC_REM_OP_ERR; 335 return COMPST_ERROR; 336 337 default: 338 pr_warn("unexpected nak %x\n", syn); 339 wqe->status = IB_WC_REM_OP_ERR; 340 return COMPST_ERROR; 341 } 342 343 default: 344 return COMPST_ERROR; 345 } 346 break; 347 348 default: 349 pr_warn("unexpected opcode\n"); 350 } 351 352 return COMPST_ERROR; 353 } 354 355 static inline enum comp_state do_read(struct rxe_qp *qp, 356 struct rxe_pkt_info *pkt, 357 struct rxe_send_wqe *wqe) 358 { 359 int ret; 360 361 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, 362 &wqe->dma, payload_addr(pkt), 363 payload_size(pkt), to_mem_obj, NULL); 364 if (ret) 365 return COMPST_ERROR; 366 367 if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK)) 368 return COMPST_COMP_ACK; 369 else 370 return COMPST_UPDATE_COMP; 371 } 372 373 static inline enum comp_state do_atomic(struct rxe_qp *qp, 374 struct rxe_pkt_info *pkt, 375 struct rxe_send_wqe *wqe) 376 { 377 int ret; 378 379 u64 atomic_orig = atmack_orig(pkt); 380 381 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, 382 &wqe->dma, &atomic_orig, 383 sizeof(u64), to_mem_obj, NULL); 384 if (ret) 385 return COMPST_ERROR; 386 else 387 return COMPST_COMP_ACK; 388 } 389 390 static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe, 391 struct rxe_cqe *cqe) 392 { 393 memset(cqe, 0, sizeof(*cqe)); 394 395 if (!qp->is_user) { 396 struct ib_wc *wc = &cqe->ibwc; 397 398 wc->wr_id = wqe->wr.wr_id; 399 wc->status = wqe->status; 400 wc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 401 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 402 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 403 wc->wc_flags = IB_WC_WITH_IMM; 404 wc->byte_len = wqe->dma.length; 405 wc->qp = &qp->ibqp; 406 } else { 407 struct ib_uverbs_wc *uwc = &cqe->uibwc; 408 409 uwc->wr_id = wqe->wr.wr_id; 410 uwc->status = wqe->status; 411 uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode); 412 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM || 413 wqe->wr.opcode == IB_WR_SEND_WITH_IMM) 414 uwc->wc_flags = IB_WC_WITH_IMM; 415 uwc->byte_len = wqe->dma.length; 416 uwc->qp_num = qp->ibqp.qp_num; 417 } 418 } 419 420 /* 421 * IBA Spec. Section 10.7.3.1 SIGNALED COMPLETIONS 422 * ---------8<---------8<------------- 423 * ...Note that if a completion error occurs, a Work Completion 424 * will always be generated, even if the signaling 425 * indicator requests an Unsignaled Completion. 426 * ---------8<---------8<------------- 427 */ 428 static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe) 429 { 430 struct rxe_cqe cqe; 431 432 if ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) || 433 (wqe->wr.send_flags & IB_SEND_SIGNALED) || 434 wqe->status != IB_WC_SUCCESS) { 435 make_send_cqe(qp, wqe, &cqe); 436 advance_consumer(qp->sq.queue); 437 rxe_cq_post(qp->scq, &cqe, 0); 438 } else { 439 advance_consumer(qp->sq.queue); 440 } 441 442 /* 443 * we completed something so let req run again 444 * if it is trying to fence 445 */ 446 if (qp->req.wait_fence) { 447 qp->req.wait_fence = 0; 448 rxe_run_task(&qp->req.task, 1); 449 } 450 } 451 452 static inline enum comp_state complete_ack(struct rxe_qp *qp, 453 struct rxe_pkt_info *pkt, 454 struct rxe_send_wqe *wqe) 455 { 456 unsigned long flags; 457 458 if (wqe->has_rd_atomic) { 459 wqe->has_rd_atomic = 0; 460 atomic_inc(&qp->req.rd_atomic); 461 if (qp->req.need_rd_atomic) { 462 qp->comp.timeout_retry = 0; 463 qp->req.need_rd_atomic = 0; 464 rxe_run_task(&qp->req.task, 1); 465 } 466 } 467 468 if (unlikely(qp->req.state == QP_STATE_DRAIN)) { 469 /* state_lock used by requester & completer */ 470 spin_lock_irqsave(&qp->state_lock, flags); 471 if ((qp->req.state == QP_STATE_DRAIN) && 472 (qp->comp.psn == qp->req.psn)) { 473 qp->req.state = QP_STATE_DRAINED; 474 spin_unlock_irqrestore(&qp->state_lock, flags); 475 476 if (qp->ibqp.event_handler) { 477 struct ib_event ev; 478 479 ev.device = qp->ibqp.device; 480 ev.element.qp = &qp->ibqp; 481 ev.event = IB_EVENT_SQ_DRAINED; 482 qp->ibqp.event_handler(&ev, 483 qp->ibqp.qp_context); 484 } 485 } else { 486 spin_unlock_irqrestore(&qp->state_lock, flags); 487 } 488 } 489 490 do_complete(qp, wqe); 491 492 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 493 return COMPST_UPDATE_COMP; 494 else 495 return COMPST_DONE; 496 } 497 498 static inline enum comp_state complete_wqe(struct rxe_qp *qp, 499 struct rxe_pkt_info *pkt, 500 struct rxe_send_wqe *wqe) 501 { 502 qp->comp.opcode = -1; 503 504 if (pkt) { 505 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 506 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; 507 508 if (qp->req.wait_psn) { 509 qp->req.wait_psn = 0; 510 rxe_run_task(&qp->req.task, 1); 511 } 512 } 513 514 do_complete(qp, wqe); 515 516 return COMPST_GET_WQE; 517 } 518 519 static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify) 520 { 521 struct sk_buff *skb; 522 struct rxe_send_wqe *wqe; 523 524 while ((skb = skb_dequeue(&qp->resp_pkts))) { 525 rxe_drop_ref(qp); 526 kfree_skb(skb); 527 } 528 529 while ((wqe = queue_head(qp->sq.queue))) { 530 if (notify) { 531 wqe->status = IB_WC_WR_FLUSH_ERR; 532 do_complete(qp, wqe); 533 } else { 534 advance_consumer(qp->sq.queue); 535 } 536 } 537 } 538 539 int rxe_completer(void *arg) 540 { 541 struct rxe_qp *qp = (struct rxe_qp *)arg; 542 struct rxe_dev *rxe = to_rdev(qp->ibqp.device); 543 struct rxe_send_wqe *wqe = wqe; 544 struct sk_buff *skb = NULL; 545 struct rxe_pkt_info *pkt = NULL; 546 enum comp_state state; 547 548 rxe_add_ref(qp); 549 550 if (!qp->valid || qp->req.state == QP_STATE_ERROR || 551 qp->req.state == QP_STATE_RESET) { 552 rxe_drain_resp_pkts(qp, qp->valid && 553 qp->req.state == QP_STATE_ERROR); 554 goto exit; 555 } 556 557 if (qp->comp.timeout) { 558 qp->comp.timeout_retry = 1; 559 qp->comp.timeout = 0; 560 } else { 561 qp->comp.timeout_retry = 0; 562 } 563 564 if (qp->req.need_retry) 565 goto exit; 566 567 state = COMPST_GET_ACK; 568 569 while (1) { 570 pr_debug("qp#%d state = %s\n", qp_num(qp), 571 comp_state_name[state]); 572 switch (state) { 573 case COMPST_GET_ACK: 574 skb = skb_dequeue(&qp->resp_pkts); 575 if (skb) { 576 pkt = SKB_TO_PKT(skb); 577 qp->comp.timeout_retry = 0; 578 } 579 state = COMPST_GET_WQE; 580 break; 581 582 case COMPST_GET_WQE: 583 state = get_wqe(qp, pkt, &wqe); 584 break; 585 586 case COMPST_CHECK_PSN: 587 state = check_psn(qp, pkt, wqe); 588 break; 589 590 case COMPST_CHECK_ACK: 591 state = check_ack(qp, pkt, wqe); 592 break; 593 594 case COMPST_READ: 595 state = do_read(qp, pkt, wqe); 596 break; 597 598 case COMPST_ATOMIC: 599 state = do_atomic(qp, pkt, wqe); 600 break; 601 602 case COMPST_WRITE_SEND: 603 if (wqe->state == wqe_state_pending && 604 wqe->last_psn == pkt->psn) 605 state = COMPST_COMP_ACK; 606 else 607 state = COMPST_UPDATE_COMP; 608 break; 609 610 case COMPST_COMP_ACK: 611 state = complete_ack(qp, pkt, wqe); 612 break; 613 614 case COMPST_COMP_WQE: 615 state = complete_wqe(qp, pkt, wqe); 616 break; 617 618 case COMPST_UPDATE_COMP: 619 if (pkt->mask & RXE_END_MASK) 620 qp->comp.opcode = -1; 621 else 622 qp->comp.opcode = pkt->opcode; 623 624 if (psn_compare(pkt->psn, qp->comp.psn) >= 0) 625 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; 626 627 if (qp->req.wait_psn) { 628 qp->req.wait_psn = 0; 629 rxe_run_task(&qp->req.task, 1); 630 } 631 632 state = COMPST_DONE; 633 break; 634 635 case COMPST_DONE: 636 if (pkt) { 637 rxe_drop_ref(pkt->qp); 638 kfree_skb(skb); 639 skb = NULL; 640 } 641 goto done; 642 643 case COMPST_EXIT: 644 if (qp->comp.timeout_retry && wqe) { 645 state = COMPST_ERROR_RETRY; 646 break; 647 } 648 649 /* re reset the timeout counter if 650 * (1) QP is type RC 651 * (2) the QP is alive 652 * (3) there is a packet sent by the requester that 653 * might be acked (we still might get spurious 654 * timeouts but try to keep them as few as possible) 655 * (4) the timeout parameter is set 656 */ 657 if ((qp_type(qp) == IB_QPT_RC) && 658 (qp->req.state == QP_STATE_READY) && 659 (psn_compare(qp->req.psn, qp->comp.psn) > 0) && 660 qp->qp_timeout_jiffies) 661 mod_timer(&qp->retrans_timer, 662 jiffies + qp->qp_timeout_jiffies); 663 goto exit; 664 665 case COMPST_ERROR_RETRY: 666 /* we come here if the retry timer fired and we did 667 * not receive a response packet. try to retry the send 668 * queue if that makes sense and the limits have not 669 * been exceeded. remember that some timeouts are 670 * spurious since we do not reset the timer but kick 671 * it down the road or let it expire 672 */ 673 674 /* there is nothing to retry in this case */ 675 if (!wqe || (wqe->state == wqe_state_posted)) { 676 goto exit; 677 } 678 679 if (qp->comp.retry_cnt > 0) { 680 if (qp->comp.retry_cnt != 7) 681 qp->comp.retry_cnt--; 682 683 /* no point in retrying if we have already 684 * seen the last ack that the requester could 685 * have caused 686 */ 687 if (psn_compare(qp->req.psn, 688 qp->comp.psn) > 0) { 689 /* tell the requester to retry the 690 * send queue next time around 691 */ 692 rxe_counter_inc(rxe, 693 RXE_CNT_COMP_RETRY); 694 qp->req.need_retry = 1; 695 rxe_run_task(&qp->req.task, 1); 696 } 697 698 if (pkt) { 699 rxe_drop_ref(pkt->qp); 700 kfree_skb(skb); 701 skb = NULL; 702 } 703 704 goto exit; 705 706 } else { 707 rxe_counter_inc(rxe, RXE_CNT_RETRY_EXCEEDED); 708 wqe->status = IB_WC_RETRY_EXC_ERR; 709 state = COMPST_ERROR; 710 } 711 break; 712 713 case COMPST_RNR_RETRY: 714 if (qp->comp.rnr_retry > 0) { 715 if (qp->comp.rnr_retry != 7) 716 qp->comp.rnr_retry--; 717 718 qp->req.need_retry = 1; 719 pr_debug("qp#%d set rnr nak timer\n", 720 qp_num(qp)); 721 mod_timer(&qp->rnr_nak_timer, 722 jiffies + rnrnak_jiffies(aeth_syn(pkt) 723 & ~AETH_TYPE_MASK)); 724 rxe_drop_ref(pkt->qp); 725 kfree_skb(skb); 726 skb = NULL; 727 goto exit; 728 } else { 729 rxe_counter_inc(rxe, 730 RXE_CNT_RNR_RETRY_EXCEEDED); 731 wqe->status = IB_WC_RNR_RETRY_EXC_ERR; 732 state = COMPST_ERROR; 733 } 734 break; 735 736 case COMPST_ERROR: 737 WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS); 738 do_complete(qp, wqe); 739 rxe_qp_error(qp); 740 741 if (pkt) { 742 rxe_drop_ref(pkt->qp); 743 kfree_skb(skb); 744 skb = NULL; 745 } 746 747 goto exit; 748 } 749 } 750 751 exit: 752 /* we come here if we are done with processing and want the task to 753 * exit from the loop calling us 754 */ 755 WARN_ON_ONCE(skb); 756 rxe_drop_ref(qp); 757 return -EAGAIN; 758 759 done: 760 /* we come here if we have processed a packet we want the task to call 761 * us again to see if there is anything else to do 762 */ 763 WARN_ON_ONCE(skb); 764 rxe_drop_ref(qp); 765 return 0; 766 } 767