From patchwork Fri Jul 23 11:06:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dongdong Liu X-Patchwork-Id: 1509133 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4GWRQF3cr4z9sXM for ; Fri, 23 Jul 2021 21:08:37 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234316AbhGWK2C (ORCPT ); Fri, 23 Jul 2021 06:28:02 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:15053 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232609AbhGWK1x (ORCPT ); Fri, 23 Jul 2021 06:27:53 -0400 Received: from dggeme758-chm.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4GWRL52RXbzZrYC; Fri, 23 Jul 2021 19:05:01 +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; Fri, 23 Jul 2021 19:08:25 +0800 From: Dongdong Liu To: , , , , , , CC: , Subject: [PATCH V6 8/8] PCI/P2PDMA: Add a 10-bit tag check in P2PDMA Date: Fri, 23 Jul 2021 19:06:42 +0800 Message-ID: <1627038402-114183-9-git-send-email-liudongdong3@huawei.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1627038402-114183-1-git-send-email-liudongdong3@huawei.com> References: <1627038402-114183-1-git-send-email-liudongdong3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.21.59.169] 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: 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 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; + map = calc_map_type_and_dist(provider, pci_client, &distance, verbose);