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=-17.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,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 D68BEC432BE for ; Fri, 23 Jul 2021 16:25:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC87B60E78 for ; Fri, 23 Jul 2021 16:25:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230126AbhGWPpW (ORCPT ); Fri, 23 Jul 2021 11:45:22 -0400 Received: from ale.deltatee.com ([204.191.154.188]:48514 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229510AbhGWPpU (ORCPT ); Fri, 23 Jul 2021 11:45:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:In-Reply-To:MIME-Version:Date: Message-ID:From:References:Cc:To:content-disposition; bh=gnwjVSuqsjlehjAwMxxPG5BYBaf6ZJv7V08qy9lOWWE=; b=TDMMZTqYytUvc4t1ahiJ/Ilp9O 8Ep10S3tiHtsLIfH8m9IFzIR6LEAjHPUrX0VwbWtA1Efv1NWlOyXwSiGu+U0AvAZ8Mfeje/GXxBgs eEFVyfHr8Z3yFuCHI8SjeXGBSS695i2KDOd1DbQjJO2NwaTaRq2/1QzXD9xa8p7xOYByw223k5nou sHd/KCEBdyBHQPzAEJmmzRP57IwrTLKJVZpl9n4s0EM7jq1tFPxvhKauIiCQRSyQJ9E1esOhq5/Ix 2wD5T923ngHCMZTuWf+t36QgqOYRF1DN2oWEXBzCIqtm5TGhEX+XWPMQA3Ah1D8fg3tbbDlPQ+fgD IsQ+tJvA==; Received: from s0106a84e3fe8c3f3.cg.shawcable.net ([24.64.144.200] helo=[192.168.0.10]) by ale.deltatee.com with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1m6xzj-00049R-Li; Fri, 23 Jul 2021 10:25:52 -0600 To: Dongdong Liu , helgaas@kernel.org, hch@infradead.org, kw@linux.com, linux-pci@vger.kernel.org, rajur@chelsio.com, hverkuil-cisco@xs4all.nl Cc: linux-media@vger.kernel.org, netdev@vger.kernel.org References: <1627038402-114183-1-git-send-email-liudongdong3@huawei.com> <1627038402-114183-9-git-send-email-liudongdong3@huawei.com> From: Logan Gunthorpe Message-ID: <24bc5deb-1fa3-8e81-2d9d-18836dc3aec9@deltatee.com> Date: Fri, 23 Jul 2021 10:25:51 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <1627038402-114183-9-git-send-email-liudongdong3@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 24.64.144.200 X-SA-Exim-Rcpt-To: netdev@vger.kernel.org, linux-media@vger.kernel.org, hverkuil-cisco@xs4all.nl, rajur@chelsio.com, linux-pci@vger.kernel.org, kw@linux.com, hch@infradead.org, helgaas@kernel.org, liudongdong3@huawei.com X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH V6 8/8] PCI/P2PDMA: Add a 10-bit tag check in P2PDMA X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2021-07-23 5:06 a.m., Dongdong Liu wrote: > Add a 10-Bit Tag check in the P2PDMA code to ensure that a device with > 10-Bit Tag Requester doesn't interact with a device that does not > support 10-BIT tag Completer. Before that happens, the kernel should > emit a warning saying to enable a ”pci=disable_10bit_tag=“ kernel > parameter. > > Signed-off-by: Dongdong Liu > --- > drivers/pci/p2pdma.c | 38 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > > diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c > index 50cdde3..bd93840 100644 > --- a/drivers/pci/p2pdma.c > +++ b/drivers/pci/p2pdma.c > @@ -19,6 +19,7 @@ > #include > #include > #include > +#include "pci.h" > > enum pci_p2pdma_map_type { > PCI_P2PDMA_MAP_UNKNOWN = 0, > @@ -541,6 +542,39 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client, > return map_type; > } > > + > +static bool check_10bit_tags_vaild(struct pci_dev *a, struct pci_dev *b, > + bool verbose) > +{ > + bool req; > + bool comp; > + u16 ctl2; > + > + if (a->is_virtfn) { > +#ifdef CONFIG_PCI_IOV > + req = !!(a->physfn->sriov->ctrl & > + PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN); > +#endif > + } else { > + pcie_capability_read_word(a, PCI_EXP_DEVCTL2, &ctl2); > + req = !!(ctl2 & PCI_EXP_DEVCTL2_10BIT_TAG_REQ_EN); > + } > + > + comp = !!(b->pcie_devcap2 & PCI_EXP_DEVCAP2_10BIT_TAG_COMP); > + if (req && (!comp)) { > + if (verbose) { > + pci_warn(a, "cannot be used for peer-to-peer DMA as 10-Bit Tag Requester enable is set in device (%s), but peer device (%s) does not support the 10-Bit Tag Completer\n", > + pci_name(a), pci_name(b)); > + > + pci_warn(a, "to disable 10-Bit Tag Requester for this device, add the kernel parameter: pci=disable_10bit_tag=%s\n", > + pci_name(a)); > + } > + return false; > + } > + > + return true; > +} > + > /** > * pci_p2pdma_distance_many - Determine the cumulative distance between > * a p2pdma provider and the clients in use. > @@ -579,6 +613,10 @@ int pci_p2pdma_distance_many(struct pci_dev *provider, struct device **clients, > return -1; > } > > + if (!check_10bit_tags_vaild(pci_client, provider, verbose) || > + !check_10bit_tags_vaild(provider, pci_client, verbose)) > + not_supported = true; > + This check needs to be done in calc_map_type_and_dist(). The mapping type needs to be correctly stored in the xarray cache as other functions rely on the cached value (and upcoming work will be calling calc_map_type_and_dist() without pci_p2pdma_distance_many()). Logan