From patchwork Sat Jan 9 09:11:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dongdong Liu X-Patchwork-Id: 1424057 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=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DCZj056jDz9shx for ; Sat, 9 Jan 2021 20:40:52 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726902AbhAIJkh (ORCPT ); Sat, 9 Jan 2021 04:40:37 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:10493 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726820AbhAIJkg (ORCPT ); Sat, 9 Jan 2021 04:40:36 -0500 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4DCZfn5mZKzj2nL; Sat, 9 Jan 2021 17:38:57 +0800 (CST) Received: from linux-ioko.site (10.78.228.23) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.498.0; Sat, 9 Jan 2021 17:39:49 +0800 From: Dongdong Liu To: , Subject: [RFC PATCH 2/3] PCI: Enable 10-bit tags support for PCIe devices Date: Sat, 9 Jan 2021 17:11:22 +0800 Message-ID: <1610183483-2061-3-git-send-email-liudongdong3@huawei.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1610183483-2061-1-git-send-email-liudongdong3@huawei.com> References: <1610183483-2061-1-git-send-email-liudongdong3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.78.228.23] 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. 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 --- drivers/pci/probe.c | 39 +++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 40 insertions(+) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 953f15a..611acce 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2051,6 +2051,44 @@ int pci_configure_extended_tags(struct pci_dev *dev, void *ign) return 0; } +static void pci_configure_10bit_tags(struct pci_dev *dev) +{ + u32 cap; + int ret; + struct pci_dev *bridge; + + if (!pci_is_pcie(dev)) + return; + + ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap); + if (ret) + return; + + if (!(cap & PCI_EXP_DEVCAP2_10BIT_TAG_COMP)) + return; + + if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { + dev->ext_10bit_tag_comp_path = 1; + return; + } + + bridge = pci_upstream_bridge(dev); + if (bridge && bridge->ext_10bit_tag_comp_path) + dev->ext_10bit_tag_comp_path = 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_comp_path == 1) { + if (cap & PCI_EXP_DEVCAP2_10BIT_TAG_REQ) + pcie_capability_set_word(dev, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_10BIT_TAG_REQ_EN); + return; + } +} + /** * pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable * @dev: PCI device to query @@ -2190,6 +2228,7 @@ static void pci_configure_device(struct pci_dev *dev) { pci_configure_mps(dev); pci_configure_extended_tags(dev, NULL); + pci_configure_10bit_tags(dev); pci_configure_relaxed_ordering(dev); pci_configure_ltr(dev); pci_configure_eetlp_prefix(dev); diff --git a/include/linux/pci.h b/include/linux/pci.h index b32126d..a6dfa2f 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -390,6 +390,7 @@ struct pci_dev { #endif unsigned int eetlp_prefix_path:1; /* End-to-End TLP Prefix */ + unsigned int ext_10bit_tag_comp_path: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 */