From patchwork Sat Oct 9 16:44:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 12547917 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 291C6C4332F for ; Sat, 9 Oct 2021 16:44:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 14E946108B for ; Sat, 9 Oct 2021 16:44:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232540AbhJIQqk (ORCPT ); Sat, 9 Oct 2021 12:46:40 -0400 Received: from mga14.intel.com ([192.55.52.115]:56364 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232477AbhJIQqh (ORCPT ); Sat, 9 Oct 2021 12:46:37 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10132"; a="226961878" X-IronPort-AV: E=Sophos;i="5.85,360,1624345200"; d="scan'208";a="226961878" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2021 09:44:40 -0700 X-IronPort-AV: E=Sophos;i="5.85,360,1624345200"; d="scan'208";a="715860710" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.25]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2021 09:44:39 -0700 Subject: [PATCH v3 08/10] PCI: Add pci_find_dvsec_capability to find designated VSEC From: Dan Williams To: linux-cxl@vger.kernel.org Cc: "David E. Box" , Jonathan Cameron , Bjorn Helgaas , linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Andrew Donnellan , Lu Baolu , Frederic Barrat , Ben Widawsky , Andrew Donnellan , Bjorn Helgaas , Kan Liang , Kan Liang , Jonathan Cameron , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, hch@lst.de Date: Sat, 09 Oct 2021 09:44:39 -0700 Message-ID: <163379787943.692348.6814373487017444007.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <163379783658.692348.16064992154261275220.stgit@dwillia2-desk3.amr.corp.intel.com> References: <163379783658.692348.16064992154261275220.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org From: Ben Widawsky Add pci_find_dvsec_capability to locate a Designated Vendor-Specific Extended Capability with the specified Vendor ID and Capability ID. The Designated Vendor-Specific Extended Capability (DVSEC) allows one or more "vendor" specific capabilities that are not tied to the Vendor ID of the PCI component. Where the DVSEC Vendor may be a standards body like CXL. Cc: David E. Box Cc: Jonathan Cameron Cc: Bjorn Helgaas Cc: Dan Williams Cc: linux-pci@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Andrew Donnellan Cc: Lu Baolu Reviewed-by: Frederic Barrat Signed-off-by: Ben Widawsky Reviewed-by: Andrew Donnellan Acked-by: Bjorn Helgaas Tested-by: Kan Liang Signed-off-by: Kan Liang Reviewed-by: Jonathan Cameron Signed-off-by: Dan Williams --- drivers/pci/pci.c | 32 ++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 33 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index ce2ab62b64cf..94ac86ff28b0 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -732,6 +732,38 @@ u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap) } EXPORT_SYMBOL_GPL(pci_find_vsec_capability); +/** + * pci_find_dvsec_capability - Find DVSEC for vendor + * @dev: PCI device to query + * @vendor: Vendor ID to match for the DVSEC + * @dvsec: Designated Vendor-specific capability ID + * + * If DVSEC has Vendor ID @vendor and DVSEC ID @dvsec return the capability + * offset in config space; otherwise return 0. + */ +u16 pci_find_dvsec_capability(struct pci_dev *dev, u16 vendor, u16 dvsec) +{ + int pos; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DVSEC); + if (!pos) + return 0; + + while (pos) { + u16 v, id; + + pci_read_config_word(dev, pos + PCI_DVSEC_HEADER1, &v); + pci_read_config_word(dev, pos + PCI_DVSEC_HEADER2, &id); + if (vendor == v && dvsec == id) + return pos; + + pos = pci_find_next_ext_capability(dev, pos, PCI_EXT_CAP_ID_DVSEC); + } + + return 0; +} +EXPORT_SYMBOL_GPL(pci_find_dvsec_capability); + /** * pci_find_parent_resource - return resource region of parent bus of given * region diff --git a/include/linux/pci.h b/include/linux/pci.h index cd8aa6fce204..c93ccfa4571b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1130,6 +1130,7 @@ u16 pci_find_ext_capability(struct pci_dev *dev, int cap); u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 pos, int cap); struct pci_bus *pci_find_next_bus(const struct pci_bus *from); u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap); +u16 pci_find_dvsec_capability(struct pci_dev *dev, u16 vendor, u16 dvsec); u64 pci_get_dsn(struct pci_dev *dev);