From patchwork Thu Apr 30 13:55:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Karsten Graul X-Patchwork-Id: 220217 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C18EC28CBC for ; Thu, 30 Apr 2020 13:56:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C1B32063A for ; Thu, 30 Apr 2020 13:56:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728292AbgD3N40 (ORCPT ); Thu, 30 Apr 2020 09:56:26 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:17018 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728074AbgD3N4X (ORCPT ); Thu, 30 Apr 2020 09:56:23 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 03UDah17141386; Thu, 30 Apr 2020 09:56:13 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0b-001b2d01.pphosted.com with ESMTP id 30qxvqam83-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 30 Apr 2020 09:56:09 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.27/8.16.0.27) with SMTP id 03UDmUra031754; Thu, 30 Apr 2020 13:56:07 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma04ams.nl.ibm.com with ESMTP id 30mcu72qdv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 30 Apr 2020 13:56:06 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 03UDu4H559179308 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 30 Apr 2020 13:56:04 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3A5A24C050; Thu, 30 Apr 2020 13:56:04 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F408C4C046; Thu, 30 Apr 2020 13:56:03 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 30 Apr 2020 13:56:03 +0000 (GMT) From: Karsten Graul To: davem@davemloft.net Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, heiko.carstens@de.ibm.com, raspl@linux.ibm.com, ubraun@linux.ibm.com Subject: [PATCH net-next 01/14] net/smc: add event-based llc_flow framework Date: Thu, 30 Apr 2020 15:55:38 +0200 Message-Id: <20200430135551.26267-2-kgraul@linux.ibm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200430135551.26267-1-kgraul@linux.ibm.com> References: <20200430135551.26267-1-kgraul@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.676 definitions=2020-04-30_08:2020-04-30,2020-04-30 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 mlxscore=0 priorityscore=1501 phishscore=0 mlxlogscore=956 suspectscore=3 malwarescore=0 lowpriorityscore=0 impostorscore=0 bulkscore=0 clxscore=1015 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004300106 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The new framework allows to start specific types of LLC control flows, protects active flows and makes it possible to wait for flows to finish before starting a new flow. This mechanism is used for the LLC control layer to model flows like 'add link' or 'delete link' which need to send/receive several LLC messages and are not allowed to get interrupted by the wrong type of messages. 'Add link' or 'Delete link' messages arriving in the middle of a flow are delayed and processed when the current flow finished. Signed-off-by: Karsten Graul Reviewed-by: Ursula Braun --- net/smc/smc_core.c | 2 + net/smc/smc_core.h | 24 +++++++ net/smc/smc_llc.c | 165 +++++++++++++++++++++++++++++++++++++++++++++ net/smc/smc_llc.h | 8 +++ 4 files changed, 199 insertions(+) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index db49f8cd5c95..4867ddcfe0c6 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -263,6 +263,7 @@ static void smc_lgr_free_work(struct work_struct *work) if (smc_link_usable(lnk)) lnk->state = SMC_LNK_INACTIVE; } + wake_up_interruptible_all(&lgr->llc_waiter); } smc_lgr_free(lgr); } @@ -696,6 +697,7 @@ static void smc_lgr_cleanup(struct smc_link_group *lgr) if (smc_link_usable(lnk)) lnk->state = SMC_LNK_INACTIVE; } + wake_up_interruptible_all(&lgr->llc_waiter); } } diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index b5781511063d..70399217ad6f 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -197,6 +197,20 @@ struct smc_rtoken { /* address/key of remote RMB */ struct smcd_dev; +enum smc_llc_flowtype { + SMC_LLC_FLOW_NONE = 0, + SMC_LLC_FLOW_ADD_LINK = 2, + SMC_LLC_FLOW_DEL_LINK = 4, + SMC_LLC_FLOW_RKEY = 6, +}; + +struct smc_llc_qentry; + +struct smc_llc_flow { + enum smc_llc_flowtype type; + struct smc_llc_qentry *qentry; +}; + struct smc_link_group { struct list_head list; struct rb_root conns_all; /* connection tree */ @@ -238,6 +252,16 @@ struct smc_link_group { /* protects llc_event_q */ struct work_struct llc_event_work; /* llc event worker */ + wait_queue_head_t llc_waiter; + /* w4 next llc event */ + struct smc_llc_flow llc_flow_lcl; + /* llc local control field */ + struct smc_llc_flow llc_flow_rmt; + /* llc remote control field */ + struct smc_llc_qentry *delayed_event; + /* arrived when flow active */ + spinlock_t llc_flow_lock; + /* protects llc flow */ int llc_testlink_time; /* link keep alive time */ }; diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index e715dd6735ee..647cf1a2dfa5 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -140,6 +140,154 @@ struct smc_llc_qentry { union smc_llc_msg msg; }; +struct smc_llc_qentry *smc_llc_flow_qentry_clr(struct smc_llc_flow *flow) +{ + struct smc_llc_qentry *qentry = flow->qentry; + + flow->qentry = NULL; + return qentry; +} + +void smc_llc_flow_qentry_del(struct smc_llc_flow *flow) +{ + struct smc_llc_qentry *qentry; + + if (flow->qentry) { + qentry = flow->qentry; + flow->qentry = NULL; + kfree(qentry); + } +} + +static inline void smc_llc_flow_qentry_set(struct smc_llc_flow *flow, + struct smc_llc_qentry *qentry) +{ + flow->qentry = qentry; +} + +/* try to start a new llc flow, initiated by an incoming llc msg */ +static bool smc_llc_flow_start(struct smc_llc_flow *flow, + struct smc_llc_qentry *qentry) +{ + struct smc_link_group *lgr = qentry->link->lgr; + + spin_lock_bh(&lgr->llc_flow_lock); + if (flow->type) { + /* a flow is already active */ + if ((qentry->msg.raw.hdr.common.type == SMC_LLC_ADD_LINK || + qentry->msg.raw.hdr.common.type == SMC_LLC_DELETE_LINK) && + !lgr->delayed_event) { + lgr->delayed_event = qentry; + } else { + /* forget this llc request */ + kfree(qentry); + } + spin_unlock_bh(&lgr->llc_flow_lock); + return false; + } + switch (qentry->msg.raw.hdr.common.type) { + case SMC_LLC_ADD_LINK: + flow->type = SMC_LLC_FLOW_ADD_LINK; + break; + case SMC_LLC_DELETE_LINK: + flow->type = SMC_LLC_FLOW_DEL_LINK; + break; + case SMC_LLC_CONFIRM_RKEY: + case SMC_LLC_DELETE_RKEY: + flow->type = SMC_LLC_FLOW_RKEY; + break; + default: + flow->type = SMC_LLC_FLOW_NONE; + } + if (qentry == lgr->delayed_event) + lgr->delayed_event = NULL; + spin_unlock_bh(&lgr->llc_flow_lock); + smc_llc_flow_qentry_set(flow, qentry); + return true; +} + +/* start a new local llc flow, wait till current flow finished */ +int smc_llc_flow_initiate(struct smc_link_group *lgr, + enum smc_llc_flowtype type) +{ + enum smc_llc_flowtype allowed_remote = SMC_LLC_FLOW_NONE; + int rc; + + /* all flows except confirm_rkey and delete_rkey are exclusive, + * confirm/delete rkey flows can run concurrently (local and remote) + */ + if (type == SMC_LLC_FLOW_RKEY) + allowed_remote = SMC_LLC_FLOW_RKEY; +again: + if (list_empty(&lgr->list)) + return -ENODEV; + spin_lock_bh(&lgr->llc_flow_lock); + if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE && + (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE || + lgr->llc_flow_rmt.type == allowed_remote)) { + lgr->llc_flow_lcl.type = type; + spin_unlock_bh(&lgr->llc_flow_lock); + return 0; + } + spin_unlock_bh(&lgr->llc_flow_lock); + rc = wait_event_interruptible_timeout(lgr->llc_waiter, + (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE && + (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE || + lgr->llc_flow_rmt.type == allowed_remote)), + SMC_LLC_WAIT_TIME); + if (!rc) + return -ETIMEDOUT; + goto again; +} + +/* finish the current llc flow */ +void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow) +{ + spin_lock_bh(&lgr->llc_flow_lock); + memset(flow, 0, sizeof(*flow)); + flow->type = SMC_LLC_FLOW_NONE; + spin_unlock_bh(&lgr->llc_flow_lock); + if (!list_empty(&lgr->list) && lgr->delayed_event && + flow == &lgr->llc_flow_lcl) + schedule_work(&lgr->llc_event_work); + else + wake_up_interruptible(&lgr->llc_waiter); +} + +/* lnk is optional and used for early wakeup when link goes down, useful in + * cases where we wait for a response on the link after we sent a request + */ +struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr, + struct smc_link *lnk, + int time_out, u8 exp_msg) +{ + struct smc_llc_flow *flow = &lgr->llc_flow_lcl; + + wait_event_interruptible_timeout(lgr->llc_waiter, + (flow->qentry || + (lnk && !smc_link_usable(lnk)) || + list_empty(&lgr->list)), + time_out); + if (!flow->qentry || + (lnk && !smc_link_usable(lnk)) || list_empty(&lgr->list)) { + smc_llc_flow_qentry_del(flow); + goto out; + } + if (exp_msg && flow->qentry->msg.raw.hdr.common.type != exp_msg) { + if (exp_msg == SMC_LLC_ADD_LINK && + flow->qentry->msg.raw.hdr.common.type == + SMC_LLC_DELETE_LINK) { + /* flow_start will delay the unexpected msg */ + smc_llc_flow_start(&lgr->llc_flow_lcl, + smc_llc_flow_qentry_clr(flow)); + return NULL; + } + smc_llc_flow_qentry_del(flow); + } +out: + return flow->qentry; +} + /********************************** send *************************************/ struct smc_llc_tx_pend { @@ -547,6 +695,16 @@ static void smc_llc_event_work(struct work_struct *work) llc_event_work); struct smc_llc_qentry *qentry; + if (!lgr->llc_flow_lcl.type && lgr->delayed_event) { + if (smc_link_usable(lgr->delayed_event->link)) { + smc_llc_event_handler(lgr->delayed_event); + } else { + qentry = lgr->delayed_event; + lgr->delayed_event = NULL; + kfree(qentry); + } + } + again: spin_lock_bh(&lgr->llc_event_q_lock); if (!list_empty(&lgr->llc_event_q)) { @@ -676,6 +834,8 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc) INIT_WORK(&lgr->llc_event_work, smc_llc_event_work); INIT_LIST_HEAD(&lgr->llc_event_q); spin_lock_init(&lgr->llc_event_q_lock); + spin_lock_init(&lgr->llc_flow_lock); + init_waitqueue_head(&lgr->llc_waiter); lgr->llc_testlink_time = net->ipv4.sysctl_tcp_keepalive_time; } @@ -683,7 +843,12 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc) void smc_llc_lgr_clear(struct smc_link_group *lgr) { smc_llc_event_flush(lgr); + wake_up_interruptible_all(&lgr->llc_waiter); cancel_work_sync(&lgr->llc_event_work); + if (lgr->delayed_event) { + kfree(lgr->delayed_event); + lgr->delayed_event = NULL; + } } int smc_llc_link_init(struct smc_link *link) diff --git a/net/smc/smc_llc.h b/net/smc/smc_llc.h index 66063f22166b..49e99ff00ee7 100644 --- a/net/smc/smc_llc.h +++ b/net/smc/smc_llc.h @@ -63,6 +63,14 @@ int smc_llc_do_confirm_rkey(struct smc_link *link, struct smc_buf_desc *rmb_desc); int smc_llc_do_delete_rkey(struct smc_link *link, struct smc_buf_desc *rmb_desc); +int smc_llc_flow_initiate(struct smc_link_group *lgr, + enum smc_llc_flowtype type); +void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow); +struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr, + struct smc_link *lnk, + int time_out, u8 exp_msg); +struct smc_llc_qentry *smc_llc_flow_qentry_clr(struct smc_llc_flow *flow); +void smc_llc_flow_qentry_del(struct smc_llc_flow *flow); int smc_llc_init(void) __init; #endif /* SMC_LLC_H */