From patchwork Wed Aug 4 13:47:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dongdong Liu X-Patchwork-Id: 12418879 X-Patchwork-Delegate: bhelgaas@google.com 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 677BCC4320A for ; Wed, 4 Aug 2021 13:49:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54A5060F58 for ; Wed, 4 Aug 2021 13:49:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238567AbhHDNtt (ORCPT ); Wed, 4 Aug 2021 09:49:49 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:12446 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238408AbhHDNtb (ORCPT ); Wed, 4 Aug 2021 09:49:31 -0400 Received: from dggeme758-chm.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4GftKz1z7bzckq3; Wed, 4 Aug 2021 21:45:43 +0800 (CST) Received: from SZX1000464847.huawei.com (10.21.59.169) 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; Wed, 4 Aug 2021 21:49:17 +0800 From: Dongdong Liu To: , , , , , , , CC: , Subject: [PATCH V7 9/9] PCI/P2PDMA: Add a 10-Bit Tag check in P2PDMA Date: Wed, 4 Aug 2021 21:47:08 +0800 Message-ID: <1628084828-119542-10-git-send-email-liudongdong3@huawei.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1628084828-119542-1-git-send-email-liudongdong3@huawei.com> References: <1628084828-119542-1-git-send-email-liudongdong3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.21.59.169] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggeme758-chm.china.huawei.com (10.3.19.104) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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. "echo 0 > /sys/bus/pci/devices/.../10bit_tag" to disable 10-BIT Tag Requester for PF device. "echo 0 > /sys/bus/pci/devices/.../sriov_vf_10bit_tag_ctl" to disable 10-BIT Tag Requester for VF device. Signed-off-by: Dongdong Liu --- drivers/pci/p2pdma.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 50cdde3..948f2be 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, @@ -410,6 +411,41 @@ static unsigned long map_types_idx(struct pci_dev *client) (client->bus->number << 8) | client->devfn; } +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)); + if (a->is_virtfn) + pci_warn(a, "to disable 10-Bit Tag Requester for this device, echo 0 > /sys/bus/pci/devices/%s/sriov_vf_10bit_tag_ctl\n", + pci_name(a)); + else + pci_warn(a, "to disable 10-Bit Tag Requester for this device, echo 0 > /sys/bus/pci/devices/%s/10bit_tag\n", + pci_name(a)); + } + return false; + } + + return true; +} + /* * Calculate the P2PDMA mapping type and distance between two PCI devices. * @@ -532,6 +568,10 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client, map_type = PCI_P2PDMA_MAP_NOT_SUPPORTED; } done: + if (!check_10bit_tags_vaild(client, provider, verbose) || + !check_10bit_tags_vaild(provider, client, verbose)) + map_type = PCI_P2PDMA_MAP_NOT_SUPPORTED; + rcu_read_lock(); p2pdma = rcu_dereference(provider->p2pdma); if (p2pdma)