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 X-Spam-Level: X-Spam-Status: No, score=-10.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 3EB38C4320E for ; Thu, 5 Aug 2021 08:38:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10F9461100 for ; Thu, 5 Aug 2021 08:38:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239638AbhHEIjK (ORCPT ); Thu, 5 Aug 2021 04:39:10 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:7793 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239572AbhHEIjK (ORCPT ); Thu, 5 Aug 2021 04:39:10 -0400 Received: from dggeme758-chm.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4GgMTM21P5zYlPd; Thu, 5 Aug 2021 16:38:47 +0800 (CST) Received: from [10.67.103.235] (10.67.103.235) by dggeme758-chm.china.huawei.com (10.3.19.104) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Thu, 5 Aug 2021 16:38:54 +0800 Subject: Re: [PATCH V7 7/9] PCI/sysfs: Add a 10-Bit Tag sysfs file To: Bjorn Helgaas References: <20210804235211.GA1693993@bjorn-Precision-5520> CC: , , , , , , , , From: Dongdong Liu Message-ID: <1b6fdf2d-cab3-3f02-5ed6-3752f8adbc0f@huawei.com> Date: Thu, 5 Aug 2021 16:38:54 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20210804235211.GA1693993@bjorn-Precision-5520> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.103.235] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggeme758-chm.china.huawei.com (10.3.19.104) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2021/8/5 7:52, Bjorn Helgaas wrote: > On Wed, Aug 04, 2021 at 09:47:06PM +0800, Dongdong Liu wrote: >> PCIe spec 5.0 r1.0 section 2.2.6.2 says that if an Endpoint supports >> sending Requests to other Endpoints (as opposed to host memory), the >> Endpoint must not send 10-Bit Tag Requests to another given Endpoint >> unless an implementation-specific mechanism determines that the Endpoint >> supports 10-Bit Tag Completer capability. Add a 10bit_tag sysfs file, >> write 0 to disable 10-Bit Tag Requester when the driver does not bind >> the device if the peer device does not support the 10-Bit Tag Completer. >> This will make P2P traffic safe. the 10bit_tag file content indicate >> current 10-Bit Tag Requester Enable status. >> >> Signed-off-by: Dongdong Liu > >> + The file is also writeable, the value only accept by write 0 >> + to disable 10-Bit Tag Requester when the driver does not bind >> + the deivce. The typical use case is for p2pdma when the peer >> + device does not support 10-BIT Tag Completer. > > s/10-BIT/10-Bit/ Will fix and will check other place. Thank, Dongdong > . >