From patchwork Tue Sep 21 22:04:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12508997 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=-16.7 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 00589C4167E for ; Tue, 21 Sep 2021 22:05:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E19A761168 for ; Tue, 21 Sep 2021 22:05:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235909AbhIUWGg (ORCPT ); Tue, 21 Sep 2021 18:06:36 -0400 Received: from mga14.intel.com ([192.55.52.115]:40128 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235902AbhIUWGg (ORCPT ); Tue, 21 Sep 2021 18:06:36 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10114"; a="223119138" X-IronPort-AV: E=Sophos;i="5.85,311,1624345200"; d="scan'208";a="223119138" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Sep 2021 15:05:06 -0700 X-IronPort-AV: E=Sophos;i="5.85,311,1624345200"; d="scan'208";a="557114687" Received: from ksankar-mobl2.amr.corp.intel.com (HELO bad-guy.kumite) ([10.252.132.1]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Sep 2021 15:05:06 -0700 From: Ben Widawsky To: linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org Cc: Ben Widawsky , "David E . Box" , Jonathan Cameron , Bjorn Helgaas , Dan Williams , linuxppc-dev@lists.ozlabs.org, Frederic Barrat , Andrew Donnellan , Alison Schofield , Ira Weiny , Jonathan Cameron , Vishal Verma Subject: [PATCH 5/7] PCI: Add pci_find_dvsec_capability to find designated VSEC Date: Tue, 21 Sep 2021 15:04:57 -0700 Message-Id: <20210921220459.2437386-6-ben.widawsky@intel.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210921220459.2437386-1-ben.widawsky@intel.com> References: <20210921220459.2437386-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Add pci_find_dvsec_capability to locate a Designated Vendor-Specific Extended Capability with the specified DVSEC ID. The Designated Vendor-Specific Extended Capability (DVSEC) allows one or more vendor specific capabilities that aren't tied to the vendor ID of the PCI component. DVSEC is critical for both the Compute Express Link (CXL) driver as well as the driver for OpenCAPI coherent accelerator (OCXL). 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: Frederic Barrat Cc: Andrew Donnellan Signed-off-by: Ben Widawsky Reviewed-by: Frederic Barrat --- 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);