From patchwork Fri Jul 23 11:06:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dongdong Liu X-Patchwork-Id: 12395883 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=ham 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 BC632C00144 for ; Fri, 23 Jul 2021 11:08:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD51D60725 for ; Fri, 23 Jul 2021 11:08:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234103AbhGWK2A (ORCPT ); Fri, 23 Jul 2021 06:28:00 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:12244 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232141AbhGWK1x (ORCPT ); Fri, 23 Jul 2021 06:27:53 -0400 Received: from dggeme758-chm.china.huawei.com (unknown [172.30.72.54]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4GWRHH4Wh2z1CMxp; Fri, 23 Jul 2021 19:02:35 +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 19:08:24 +0800 From: Dongdong Liu To: , , , , , , CC: , Subject: [PATCH V6 4/8] PCI: Enable 10-Bit tag support for PCIe Endpoint devices Date: Fri, 23 Jul 2021 19:06:38 +0800 Message-ID: <1627038402-114183-5-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 10-Bit Tag capability, introduced in PCIe-4.0 increases the total Tag field size from 8 bits to 10 bits. PCIe spec 5.0 r1.0 section 2.2.6.2 "Considerations for Implementing 10-Bit Tag Capabilities" Implementation Note. For platforms where the RC supports 10-Bit Tag Completer capability, it is highly recommended for platform firmware or operating software that configures PCIe hierarchies to Set the 10-Bit Tag Requester Enable bit automatically in Endpoints with 10-Bit Tag Requester capability. This enables the important class of 10-Bit Tag capable adapters that send Memory Read Requests only to host memory. Signed-off-by: Dongdong Liu Reviewed-by: Christoph Hellwig --- drivers/pci/probe.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++- include/linux/pci.h | 2 ++ 2 files changed, 48 insertions(+), 1 deletion(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c83245b..3da7baa 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2029,10 +2029,42 @@ static void pci_configure_mps(struct pci_dev *dev) p_mps, mps, mpss); } +static void pci_configure_10bit_tags(struct pci_dev *dev) +{ + struct pci_dev *bridge; + + if (!(dev->pcie_devcap2 & PCI_EXP_DEVCAP2_10BIT_TAG_COMP)) + return; + + if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { + dev->ext_10bit_tag = 1; + return; + } + + bridge = pci_upstream_bridge(dev); + if (bridge && bridge->ext_10bit_tag) + dev->ext_10bit_tag = 1; + + /* + * 10-Bit Tag Requester Enable in Device Control 2 Register is RsvdP + * for VF. + */ + if (dev->is_virtfn) + return; + + if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT && + dev->ext_10bit_tag == 1 && + (dev->pcie_devcap2 & PCI_EXP_DEVCAP2_10BIT_TAG_REQ)) { + pci_dbg(dev, "enabling 10-Bit Tag Requester\n"); + pcie_capability_set_word(dev, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_10BIT_TAG_REQ_EN); + } +} + int pci_configure_extended_tags(struct pci_dev *dev, void *ign) { struct pci_host_bridge *host; - u16 ctl; + u16 ctl, ctl2; int ret; if (!pci_is_pcie(dev)) @@ -2045,6 +2077,10 @@ int pci_configure_extended_tags(struct pci_dev *dev, void *ign) if (ret) return 0; + ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &ctl2); + if (ret) + return 0; + host = pci_find_host_bridge(dev->bus); if (!host) return 0; @@ -2059,6 +2095,12 @@ int pci_configure_extended_tags(struct pci_dev *dev, void *ign) pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_EXT_TAG); } + + if (ctl2 & PCI_EXP_DEVCTL2_10BIT_TAG_REQ_EN) { + pci_info(dev, "disabling 10-Bit Tags\n"); + pcie_capability_clear_word(dev, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_10BIT_TAG_REQ_EN); + } return 0; } @@ -2067,6 +2109,9 @@ int pci_configure_extended_tags(struct pci_dev *dev, void *ign) pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_EXT_TAG); } + + pci_configure_10bit_tags(dev); + return 0; } diff --git a/include/linux/pci.h b/include/linux/pci.h index 9aab67f..af6cb53 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -393,6 +393,8 @@ struct pci_dev { #endif unsigned int eetlp_prefix_path:1; /* End-to-End TLP Prefix */ + unsigned int ext_10bit_tag:1; /* 10-Bit Tag Completer Supported + from root to here */ pci_channel_state_t error_state; /* Current connectivity state */ struct device dev; /* Generic device interface */