From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37B39E77351 for ; Sat, 30 Sep 2023 08:41:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229557AbjI3Ilz (ORCPT ); Sat, 30 Sep 2023 04:41:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229489AbjI3Ilz (ORCPT ); Sat, 30 Sep 2023 04:41:55 -0400 Received: from out30-124.freemail.mail.aliyun.com (out30-124.freemail.mail.aliyun.com [115.124.30.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D83741A4; Sat, 30 Sep 2023 01:41:50 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046056;MF=guwen@linux.alibaba.com;NM=1;PH=DS;RN=17;SR=0;TI=SMTPD_---0Vt5scEN_1696063306; Received: from 30.236.0.214(mailfrom:guwen@linux.alibaba.com fp:SMTPD_---0Vt5scEN_1696063306) by smtp.aliyun-inc.com; Sat, 30 Sep 2023 16:41:48 +0800 Message-ID: <643c479a-b8bc-7526-330a-5c3f5547385c@linux.alibaba.com> Date: Sat, 30 Sep 2023 16:41:45 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH net-next v4 03/18] net/smc: extract v2 check helper from SMC-D device registration To: Jan Karcher , kgraul@linux.ibm.com, wenjia@linux.ibm.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: wintera@linux.ibm.com, schnelle@linux.ibm.com, gbayer@linux.ibm.com, pasic@linux.ibm.com, alibuda@linux.alibaba.com, tonylu@linux.alibaba.com, dust.li@linux.alibaba.com, linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <1695568613-125057-1-git-send-email-guwen@linux.alibaba.com> <1695568613-125057-4-git-send-email-guwen@linux.alibaba.com> <902e41df-0c98-c8ef-09cb-a92cf053f9d2@linux.ibm.com> From: Wen Gu In-Reply-To: <902e41df-0c98-c8ef-09cb-a92cf053f9d2@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On 2023/9/28 11:08, Jan Karcher wrote: > > > On 24/09/2023 17:16, Wen Gu wrote: >> This patch extracts v2-capable logic from the process of registering the >> ISM device as an SMC-D device, so that the registration process of other >> underlying devices can reuse it. >> >> Signed-off-by: Wen Gu >> --- >>   net/smc/smc_ism.c | 29 ++++++++++++++++++----------- >>   net/smc/smc_ism.h |  1 + >>   2 files changed, 19 insertions(+), 11 deletions(-) >> >> diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c >> index 455ae0a..8f1ba74 100644 >> --- a/net/smc/smc_ism.c >> +++ b/net/smc/smc_ism.c >> @@ -69,6 +69,22 @@ bool smc_ism_is_v2_capable(void) >>       return smc_ism_v2_capable; >>   } >> +/* must be called under smcd_dev_list.mutex lock */ >> +void smc_ism_check_v2_capable(struct smcd_dev *smcd) >> +{ >> +    u8 *system_eid = NULL; >> + >> +    if (smc_ism_v2_capable) >> +        return; >> + >> +    system_eid = smcd->ops->get_system_eid(); >> +    if (smcd->ops->supports_v2()) { >> +        smc_ism_v2_capable = true; >> +        memcpy(smc_ism_v2_system_eid, system_eid, >> +               SMC_MAX_EID_LEN); >> +    } >> +} >> + >>   /* Set a connection using this DMBE. */ >>   void smc_ism_set_conn(struct smc_connection *conn) >>   { >> @@ -423,16 +439,7 @@ static void smcd_register_dev(struct ism_dev *ism) >>           smc_pnetid_by_table_smcd(smcd); >>       mutex_lock(&smcd_dev_list.mutex); >> -    if (list_empty(&smcd_dev_list.list)) { >> -        u8 *system_eid = NULL; >> - >> -        system_eid = smcd->ops->get_system_eid(); >> -        if (smcd->ops->supports_v2()) { >> -            smc_ism_v2_capable = true; >> -            memcpy(smc_ism_v2_system_eid, system_eid, >> -                   SMC_MAX_EID_LEN); >> -        } >> -    } >> +    smc_ism_check_v2_capable(smcd); > > The list_empty check is omitted here which means the smc_ism_check_v2_capable does not touch the list. > So i think the call could be placed prior the mutex_lock. > Good catch. I omitted the list_empty check in this version but forget to remove 'the lock comments' and place the helper prior to the mutex_lock. It will be fixed. Thank you. >>       /* sort list: devices without pnetid before devices with pnetid */ >>       if (smcd->pnetid[0]) >>           list_add_tail(&smcd->list, &smcd_dev_list.list); >> @@ -535,10 +542,10 @@ int smc_ism_init(void) >>   { >>       int rc = 0; >> -#if IS_ENABLED(CONFIG_ISM) >>       smc_ism_v2_capable = false; >>       memset(smc_ism_v2_system_eid, 0, SMC_MAX_EID_LEN); >> +#if IS_ENABLED(CONFIG_ISM) >>       rc = ism_register_client(&smc_ism_client); >>   #endif >>       return rc; >> diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h >> index 832b2f4..14d2e77 100644 >> --- a/net/smc/smc_ism.h >> +++ b/net/smc/smc_ism.h >> @@ -42,6 +42,7 @@ int smc_ism_register_dmb(struct smc_link_group *lgr, int buf_size, >>   void smc_ism_get_system_eid(u8 **eid); >>   u16 smc_ism_get_chid(struct smcd_dev *dev); >>   bool smc_ism_is_v2_capable(void); >> +void smc_ism_check_v2_capable(struct smcd_dev *dev); >>   int smc_ism_init(void); >>   void smc_ism_exit(void); >>   int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb);