From patchwork Wed Sep 16 13:42:56 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Heib X-Patchwork-Id: 7195091 Return-Path: X-Original-To: patchwork-linux-rdma@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 26DDBBEEC1 for ; Wed, 16 Sep 2015 13:44:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5ECD12081D for ; Wed, 16 Sep 2015 13:44:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BA3F20862 for ; Wed, 16 Sep 2015 13:44:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753407AbbIPNoh (ORCPT ); Wed, 16 Sep 2015 09:44:37 -0400 Received: from [193.47.165.129] ([193.47.165.129]:58890 "EHLO mellanox.co.il" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752110AbbIPNoh (ORCPT ); Wed, 16 Sep 2015 09:44:37 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from kamalh@mellanox.com) with ESMTPS (AES256-SHA encrypted); 16 Sep 2015 16:43:21 +0300 Received: from r-vnc04.mtr.labs.mlnx (r-vnc04.mtr.labs.mlnx [10.208.0.116]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id t8GDh9cV015033; Wed, 16 Sep 2015 16:43:12 +0300 From: Kamal Heib To: Doug Ledford Cc: linux-rdma@vger.kernel.org, Liran Liss , Tal Alon , Kamal Heib , Amir Vadai Subject: [PATCH rdma-next 22/32] IB/rxe: Completion handling Date: Wed, 16 Sep 2015 16:42:56 +0300 Message-Id: <1442410986-28232-23-git-send-email-kamalh@mellanox.com> X-Mailer: git-send-email 1.7.8.2 In-Reply-To: <1442410986-28232-1-git-send-email-kamalh@mellanox.com> References: <1442410986-28232-1-git-send-email-kamalh@mellanox.com> Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Handling of Work Completions. Signed-off-by: Kamal Heib Signed-off-by: Amir Vadai --- drivers/staging/rxe/rxe_comp.c | 728 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 728 insertions(+) create mode 100644 drivers/staging/rxe/rxe_comp.c diff --git a/drivers/staging/rxe/rxe_comp.c b/drivers/staging/rxe/rxe_comp.c new file mode 100644 index 0000000..00a4cf7 --- /dev/null +++ b/drivers/staging/rxe/rxe_comp.c @@ -0,0 +1,728 @@ +/* + * Copyright (c) 2015 Mellanox Technologies Ltd. All rights reserved. + * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include + +#include "rxe.h" +#include "rxe_loc.h" +#include "rxe_queue.h" +#include "rxe_task.h" + +enum comp_state { + COMPST_GET_ACK, + COMPST_GET_WQE, + COMPST_COMP_WQE, + COMPST_COMP_ACK, + COMPST_CHECK_PSN, + COMPST_CHECK_ACK, + COMPST_READ, + COMPST_ATOMIC, + COMPST_WRITE_SEND, + COMPST_UPDATE_COMP, + COMPST_ERROR_RETRY, + COMPST_RNR_RETRY, + COMPST_ERROR, + COMPST_EXIT, /* We have an issue, and we want to rerun the completer */ + COMPST_DONE, /* The completer finished successflly */ +}; + +static char *comp_state_name[] = { + [COMPST_GET_ACK] = "GET ACK", + [COMPST_GET_WQE] = "GET WQE", + [COMPST_COMP_WQE] = "COMP WQE", + [COMPST_COMP_ACK] = "COMP ACK", + [COMPST_CHECK_PSN] = "CHECK PSN", + [COMPST_CHECK_ACK] = "CHECK ACK", + [COMPST_READ] = "READ", + [COMPST_ATOMIC] = "ATOMIC", + [COMPST_WRITE_SEND] = "WRITE/SEND", + [COMPST_UPDATE_COMP] = "UPDATE COMP", + [COMPST_ERROR_RETRY] = "ERROR RETRY", + [COMPST_RNR_RETRY] = "RNR RETRY", + [COMPST_ERROR] = "ERROR", + [COMPST_EXIT] = "EXIT", + [COMPST_DONE] = "DONE", +}; + +static unsigned long rnrnak_usec[32] = { + [IB_RNR_TIMER_655_36] = 655360, + [IB_RNR_TIMER_000_01] = 10, + [IB_RNR_TIMER_000_02] = 20, + [IB_RNR_TIMER_000_03] = 30, + [IB_RNR_TIMER_000_04] = 40, + [IB_RNR_TIMER_000_06] = 60, + [IB_RNR_TIMER_000_08] = 80, + [IB_RNR_TIMER_000_12] = 120, + [IB_RNR_TIMER_000_16] = 160, + [IB_RNR_TIMER_000_24] = 240, + [IB_RNR_TIMER_000_32] = 320, + [IB_RNR_TIMER_000_48] = 480, + [IB_RNR_TIMER_000_64] = 640, + [IB_RNR_TIMER_000_96] = 960, + [IB_RNR_TIMER_001_28] = 1280, + [IB_RNR_TIMER_001_92] = 1920, + [IB_RNR_TIMER_002_56] = 2560, + [IB_RNR_TIMER_003_84] = 3840, + [IB_RNR_TIMER_005_12] = 5120, + [IB_RNR_TIMER_007_68] = 7680, + [IB_RNR_TIMER_010_24] = 10240, + [IB_RNR_TIMER_015_36] = 15360, + [IB_RNR_TIMER_020_48] = 20480, + [IB_RNR_TIMER_030_72] = 30720, + [IB_RNR_TIMER_040_96] = 40960, + [IB_RNR_TIMER_061_44] = 61410, + [IB_RNR_TIMER_081_92] = 81920, + [IB_RNR_TIMER_122_88] = 122880, + [IB_RNR_TIMER_163_84] = 163840, + [IB_RNR_TIMER_245_76] = 245760, + [IB_RNR_TIMER_327_68] = 327680, + [IB_RNR_TIMER_491_52] = 491520, +}; + +static inline unsigned long rnrnak_jiffies(u8 timeout) +{ + return max_t(unsigned long, + usecs_to_jiffies(rnrnak_usec[timeout]), 1); +} + +static enum ib_wc_opcode wr_to_wc_opcode(enum ib_wr_opcode opcode) +{ + switch (opcode) { + case IB_WR_RDMA_WRITE: return IB_WC_RDMA_WRITE; + case IB_WR_RDMA_WRITE_WITH_IMM: return IB_WC_RDMA_WRITE; + case IB_WR_SEND: return IB_WC_SEND; + case IB_WR_SEND_WITH_IMM: return IB_WC_SEND; + case IB_WR_RDMA_READ: return IB_WC_RDMA_READ; + case IB_WR_ATOMIC_CMP_AND_SWP: return IB_WC_COMP_SWAP; + case IB_WR_ATOMIC_FETCH_AND_ADD: return IB_WC_FETCH_ADD; + case IB_WR_LSO: return IB_WC_LSO; + case IB_WR_SEND_WITH_INV: return IB_WC_SEND; + case IB_WR_RDMA_READ_WITH_INV: return IB_WC_RDMA_READ; + case IB_WR_LOCAL_INV: return IB_WC_LOCAL_INV; + case IB_WR_FAST_REG_MR: return IB_WC_FAST_REG_MR; + + default: + return 0xff; + } +} + +void retransmit_timer(unsigned long data) +{ + struct rxe_qp *qp = (struct rxe_qp *)data; + + if (qp->valid) { + qp->comp.timeout = 1; + rxe_run_task(&qp->comp.task, 1); + } +} + +void rxe_comp_queue_pkt(struct rxe_dev *rxe, struct rxe_qp *qp, + struct sk_buff *skb) +{ + int must_sched; + + skb_queue_tail(&qp->resp_pkts, skb); + + must_sched = skb_queue_len(&qp->resp_pkts) > 1; + rxe_run_task(&qp->comp.task, must_sched); +} + +static inline enum comp_state get_wqe(struct rxe_qp *qp, + struct rxe_pkt_info *pkt, + struct rxe_send_wqe **wqe_p) +{ + struct rxe_send_wqe *wqe; + + /* we come here whether or not we found a response packet to see if + * there are any posted WQEs + */ + wqe = queue_head(qp->sq.queue); + *wqe_p = wqe; + + /* no WQE or requester has not started it yet */ + if (!wqe || wqe->state == wqe_state_posted) + return pkt ? COMPST_DONE : COMPST_EXIT; + + /* WQE does not require an ack */ + if (wqe->state == wqe_state_done) + return COMPST_COMP_WQE; + + /* WQE caused an error */ + if (wqe->state == wqe_state_error) + return COMPST_ERROR; + + /* we have a WQE, if we also have an ack check its PSN */ + return pkt ? COMPST_CHECK_PSN : COMPST_EXIT; +} + +static inline void reset_retry_counters(struct rxe_qp *qp) +{ + qp->comp.retry_cnt = qp->attr.retry_cnt; + qp->comp.rnr_retry = qp->attr.rnr_retry; +} + +static inline enum comp_state check_psn(struct rxe_qp *qp, + struct rxe_pkt_info *pkt, + struct rxe_send_wqe *wqe) +{ + s32 diff; + + /* check to see if response is past the oldest WQE. if it is, complete + * send/write or error read/atomic + */ + diff = psn_compare(pkt->psn, wqe->last_psn); + if (diff > 0) { + if (wqe->state == wqe_state_pending) { + if (wqe->mask & WR_ATOMIC_OR_READ_MASK) + return COMPST_ERROR_RETRY; + + reset_retry_counters(qp); + return COMPST_COMP_WQE; + } else { + return COMPST_DONE; + } + } + + /* compare response packet to expected response */ + diff = psn_compare(pkt->psn, qp->comp.psn); + if (diff < 0) { + /* response is most likely a retried packet if it matches an + * uncompleted WQE go complete it else ignore it + */ + if (pkt->psn == wqe->last_psn) + return COMPST_COMP_ACK; + else + return COMPST_DONE; + } else if ((diff > 0) && (wqe->mask & WR_ATOMIC_OR_READ_MASK)) { + return COMPST_ERROR_RETRY; + } else { + return COMPST_CHECK_ACK; + } +} + +static inline enum comp_state check_ack(struct rxe_qp *qp, + struct rxe_pkt_info *pkt, + struct rxe_send_wqe *wqe) +{ + unsigned int mask = pkt->mask; + u8 syn; + + /* Check the sequence only */ + switch (qp->comp.opcode) { + case -1: + /* Will catch all *_ONLY cases. */ + if (!(mask & RXE_START_MASK)) + return COMPST_ERROR; + + break; + + case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: + case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: + if (pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE && + pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST) { + return COMPST_ERROR; + } + break; + default: + WARN_ON(1); + } + + /* Check operation validity. */ + switch (pkt->opcode) { + case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST: + case IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST: + case IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY: + syn = aeth_syn(pkt); + + if ((syn & AETH_TYPE_MASK) != AETH_ACK) + return COMPST_ERROR; + + /* Fall through (IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE + * doesn't have an AETH) + */ + case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE: + if (wqe->wr.opcode != IB_WR_RDMA_READ && + wqe->wr.opcode != IB_WR_RDMA_READ_WITH_INV) { + return COMPST_ERROR; + } + reset_retry_counters(qp); + return COMPST_READ; + + case IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE: + syn = aeth_syn(pkt); + + if ((syn & AETH_TYPE_MASK) != AETH_ACK) + return COMPST_ERROR; + + if (wqe->wr.opcode != IB_WR_ATOMIC_CMP_AND_SWP && + wqe->wr.opcode != IB_WR_ATOMIC_FETCH_AND_ADD) + return COMPST_ERROR; + reset_retry_counters(qp); + return COMPST_ATOMIC; + + case IB_OPCODE_RC_ACKNOWLEDGE: + syn = aeth_syn(pkt); + switch (syn & AETH_TYPE_MASK) { + case AETH_ACK: + reset_retry_counters(qp); + return COMPST_WRITE_SEND; + + case AETH_RNR_NAK: + return COMPST_RNR_RETRY; + + case AETH_NAK: + switch (syn) { + case AETH_NAK_PSN_SEQ_ERROR: + /* a nak implicitly acks all packets with psns + * before + */ + if (psn_compare(pkt->psn, qp->comp.psn) > 0) { + qp->comp.psn = pkt->psn; + if (qp->req.wait_psn) { + qp->req.wait_psn = 0; + rxe_run_task(&qp->req.task, 1); + } + } + return COMPST_ERROR_RETRY; + + case AETH_NAK_INVALID_REQ: + wqe->status = IB_WC_REM_INV_REQ_ERR; + return COMPST_ERROR; + + case AETH_NAK_REM_ACC_ERR: + wqe->status = IB_WC_REM_ACCESS_ERR; + return COMPST_ERROR; + + case AETH_NAK_REM_OP_ERR: + wqe->status = IB_WC_REM_OP_ERR; + return COMPST_ERROR; + + default: + pr_warn("unexpected nak %x\n", syn); + wqe->status = IB_WC_REM_OP_ERR; + return COMPST_ERROR; + } + + default: + return COMPST_ERROR; + } + break; + + default: + pr_warn("unexpected opcode\n"); + } + + return COMPST_ERROR; +} + +static inline enum comp_state do_read(struct rxe_qp *qp, + struct rxe_pkt_info *pkt, + struct rxe_send_wqe *wqe) +{ + struct rxe_dev *rxe = to_rdev(qp->ibqp.device); + int ret; + + ret = copy_data(rxe, qp->pd, IB_ACCESS_LOCAL_WRITE, + &wqe->dma, payload_addr(pkt), + payload_size(pkt), to_mem_obj, NULL); + if (ret) + return COMPST_ERROR; + + if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK)) + return COMPST_COMP_ACK; + else + return COMPST_UPDATE_COMP; +} + +static inline enum comp_state do_atomic(struct rxe_qp *qp, + struct rxe_pkt_info *pkt, + struct rxe_send_wqe *wqe) +{ + struct rxe_dev *rxe = to_rdev(qp->ibqp.device); + int ret; + + u64 atomic_orig = atmack_orig(pkt); + + ret = copy_data(rxe, qp->pd, IB_ACCESS_LOCAL_WRITE, + &wqe->dma, &atomic_orig, + sizeof(u64), to_mem_obj, NULL); + if (ret) + return COMPST_ERROR; + else + return COMPST_COMP_ACK; +} + +static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe, + struct rxe_cqe *cqe) +{ + memset(cqe, 0, sizeof(*cqe)); + + if (!qp->is_user) { + struct ib_wc *wc = &cqe->ibwc; + + wc->wr_id = wqe->wr.wr_id; + wc->status = wqe->status; + wc->opcode = wr_to_wc_opcode(wqe->wr.opcode); + wc->byte_len = wqe->dma.length; + wc->qp = &qp->ibqp; + } else { + struct ib_uverbs_wc *uwc = &cqe->uibwc; + + uwc->wr_id = wqe->wr.wr_id; + uwc->status = wqe->status; + uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode); + uwc->byte_len = wqe->dma.length; + uwc->qp_num = qp->ibqp.qp_num; + } +} + +static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe) +{ + struct rxe_cqe cqe; + + if ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) || + (wqe->wr.send_flags & IB_SEND_SIGNALED) || + (qp->req.state == QP_STATE_ERROR)) { + make_send_cqe(qp, wqe, &cqe); + rxe_cq_post(qp->scq, &cqe, 0); + } + + advance_consumer(qp->sq.queue); + + /* + * we completed something so let req run again + * if it is trying to fence + */ + if (qp->req.wait_fence) { + qp->req.wait_fence = 0; + rxe_run_task(&qp->req.task, 1); + } +} + +static inline enum comp_state complete_ack(struct rxe_qp *qp, + struct rxe_pkt_info *pkt, + struct rxe_send_wqe *wqe) +{ + unsigned long flags; + + if (wqe->has_rd_atomic) { + wqe->has_rd_atomic = 0; + atomic_inc(&qp->req.rd_atomic); + if (qp->req.need_rd_atomic) { + qp->comp.timeout_retry = 0; + qp->req.need_rd_atomic = 0; + rxe_run_task(&qp->req.task, 1); + } + } + + if (unlikely(qp->req.state == QP_STATE_DRAIN)) { + /* state_lock used by requester & completer */ + spin_lock_irqsave(&qp->state_lock, flags); + if ((qp->req.state == QP_STATE_DRAIN) && + (qp->comp.psn == qp->req.psn)) { + qp->req.state = QP_STATE_DRAINED; + spin_unlock_irqrestore(&qp->state_lock, flags); + + if (qp->ibqp.event_handler) { + struct ib_event ev; + + ev.device = qp->ibqp.device; + ev.element.qp = &qp->ibqp; + ev.event = IB_EVENT_SQ_DRAINED; + qp->ibqp.event_handler(&ev, + qp->ibqp.qp_context); + } + } else { + spin_unlock_irqrestore(&qp->state_lock, flags); + } + } + + do_complete(qp, wqe); + + if (psn_compare(pkt->psn, qp->comp.psn) >= 0) + return COMPST_UPDATE_COMP; + else + return COMPST_DONE; +} + +static inline enum comp_state complete_wqe(struct rxe_qp *qp, + struct rxe_pkt_info *pkt, + struct rxe_send_wqe *wqe) +{ + qp->comp.opcode = -1; + + if (pkt) { + if (psn_compare(pkt->psn, qp->comp.psn) >= 0) + qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; + + if (qp->req.wait_psn) { + qp->req.wait_psn = 0; + rxe_run_task(&qp->req.task, 1); + } + } + + do_complete(qp, wqe); + + return COMPST_GET_WQE; +} + +int rxe_completer(void *arg) +{ + struct rxe_qp *qp = (struct rxe_qp *)arg; + struct rxe_send_wqe *wqe = wqe; + struct sk_buff *skb = NULL; + struct rxe_pkt_info *pkt = NULL; + enum comp_state state; + + if (!qp->valid) { + while ((skb = skb_dequeue(&qp->resp_pkts))) { + rxe_drop_ref(qp); + kfree_skb(skb); + } + skb = NULL; + pkt = NULL; + + while (queue_head(qp->sq.queue)) + advance_consumer(qp->sq.queue); + + goto exit; + } + + if (qp->req.state == QP_STATE_ERROR) { + while ((skb = skb_dequeue(&qp->resp_pkts))) { + rxe_drop_ref(qp); + kfree_skb(skb); + } + skb = NULL; + pkt = NULL; + + while ((wqe = queue_head(qp->sq.queue))) { + wqe->status = IB_WC_WR_FLUSH_ERR; + do_complete(qp, wqe); + } + + goto exit; + } + + if (qp->req.state == QP_STATE_RESET) { + while ((skb = skb_dequeue(&qp->resp_pkts))) { + rxe_drop_ref(qp); + kfree_skb(skb); + } + skb = NULL; + pkt = NULL; + + while (queue_head(qp->sq.queue)) + advance_consumer(qp->sq.queue); + + goto exit; + } + + if (qp->comp.timeout) { + qp->comp.timeout_retry = 1; + qp->comp.timeout = 0; + } else { + qp->comp.timeout_retry = 0; + } + + if (qp->req.need_retry) + goto exit; + + state = COMPST_GET_ACK; + + while (1) { + pr_debug("state = %s\n", comp_state_name[state]); + switch (state) { + case COMPST_GET_ACK: + skb = skb_dequeue(&qp->resp_pkts); + if (skb) { + pkt = SKB_TO_PKT(skb); + qp->comp.timeout_retry = 0; + } + state = COMPST_GET_WQE; + break; + + case COMPST_GET_WQE: + state = get_wqe(qp, pkt, &wqe); + break; + + case COMPST_CHECK_PSN: + state = check_psn(qp, pkt, wqe); + break; + + case COMPST_CHECK_ACK: + state = check_ack(qp, pkt, wqe); + break; + + case COMPST_READ: + state = do_read(qp, pkt, wqe); + break; + + case COMPST_ATOMIC: + state = do_atomic(qp, pkt, wqe); + break; + + case COMPST_WRITE_SEND: + if (wqe->state == wqe_state_pending && + wqe->last_psn == pkt->psn) + state = COMPST_COMP_ACK; + else + state = COMPST_UPDATE_COMP; + break; + + case COMPST_COMP_ACK: + state = complete_ack(qp, pkt, wqe); + break; + + case COMPST_COMP_WQE: + state = complete_wqe(qp, pkt, wqe); + break; + + case COMPST_UPDATE_COMP: + if (pkt->mask & RXE_END_MASK) + qp->comp.opcode = -1; + else + qp->comp.opcode = pkt->opcode; + + if (psn_compare(pkt->psn, qp->comp.psn) >= 0) + qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK; + + if (qp->req.wait_psn) { + qp->req.wait_psn = 0; + rxe_run_task(&qp->req.task, 1); + } + + state = COMPST_DONE; + break; + + case COMPST_DONE: + if (pkt) { + rxe_drop_ref(pkt->qp); + kfree_skb(skb); + } + goto done; + + case COMPST_EXIT: + if (qp->comp.timeout_retry && wqe) { + state = COMPST_ERROR_RETRY; + break; + } + + /* re reset the timeout counter if + * (1) QP is type RC + * (2) the QP is alive + * (3) there is a packet sent by the requester that + * might be acked (we still might get spurious + * timeouts but try to keep them as few as possible) + * (4) the timeout parameter is set + */ + if ((qp_type(qp) == IB_QPT_RC) && + (qp->req.state == QP_STATE_READY) && + (psn_compare(qp->req.psn, qp->comp.psn) > 0) && + qp->qp_timeout_jiffies) + mod_timer(&qp->retrans_timer, + jiffies + qp->qp_timeout_jiffies); + goto exit; + + case COMPST_ERROR_RETRY: + /* we come here if the retry timer fired and we did + * not receive a response packet. try to retry the send + * queue if that makes sense and the limits have not + * been exceeded. remember that some timeouts are + * spurious since we do not reset the timer but kick + * it down the road or let it expire + */ + + /* there is nothing to retry in this case */ + if (!wqe || (wqe->state == wqe_state_posted)) + goto exit; + + if (qp->comp.retry_cnt > 0) { + if (qp->comp.retry_cnt != 7) + qp->comp.retry_cnt--; + + /* no point in retrying if we have already + * seen the last ack that the requester could + * have caused + */ + if (psn_compare(qp->req.psn, + qp->comp.psn) > 0) { + /* tell the requester to retry the + * send send queue next time around + */ + qp->req.need_retry = 1; + rxe_run_task(&qp->req.task, 1); + } + goto exit; + } else { + wqe->status = IB_WC_RETRY_EXC_ERR; + state = COMPST_ERROR; + } + break; + + case COMPST_RNR_RETRY: + if (qp->comp.rnr_retry > 0) { + if (qp->comp.rnr_retry != 7) + qp->comp.rnr_retry--; + + qp->req.need_retry = 1; + pr_debug("set rnr nak timer\n"); + mod_timer(&qp->rnr_nak_timer, + jiffies + rnrnak_jiffies(aeth_syn(pkt) + & ~AETH_TYPE_MASK)); + goto exit; + } else { + wqe->status = IB_WC_RNR_RETRY_EXC_ERR; + state = COMPST_ERROR; + } + break; + + case COMPST_ERROR: + do_complete(qp, wqe); + rxe_qp_error(qp); + goto exit; + } + } + +exit: + /* we come here if we are done with processing and want the task to + * exit from the loop calling us + */ + return -EAGAIN; + +done: + /* we come here if we have processed a packet we want the task to call + * us again to see if there is anything else to do + */ + return 0; +}