From patchwork Thu Feb 11 09:12:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gustavo Pimentel X-Patchwork-Id: 1439367 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; dkim=pass (2048-bit key; unprotected) header.d=synopsys.com header.i=@synopsys.com header.a=rsa-sha256 header.s=mail header.b=TdvJtSgU; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Dbrf056z8z9sB4 for ; Thu, 11 Feb 2021 20:18:32 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229971AbhBKJSX (ORCPT ); Thu, 11 Feb 2021 04:18:23 -0500 Received: from smtprelay-out1.synopsys.com ([149.117.87.133]:56796 "EHLO smtprelay-out1.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230108AbhBKJOM (ORCPT ); Thu, 11 Feb 2021 04:14:12 -0500 Received: from mailhost.synopsys.com (mdc-mailhost2.synopsys.com [10.225.0.210]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by smtprelay-out1.synopsys.com (Postfix) with ESMTPS id 4FA11C00C5; Thu, 11 Feb 2021 09:12:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1613034779; bh=xSw5LvD/YxXUJeeq0fPt2fEv2IzUw5tDpPF/ckOJIV0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:From; b=TdvJtSgUpmmC+ly6Drd8sTpXaTE1G97pOUNKuA9O09B/X8ZfoA5obL1aFW3FWEKu8 gACUxJnQwGwdb7pL0r5xdC6FPcYud2/TEdjKeMtvj1xUkFYs7lYbH9AI/6ANRHvO3A UcQyfnk30kZw8B9538pjckxgSigvBwFmYOHZ1CxBGsw5pBRR+wb444vFeqNs5PJ/9Q M9D96Gv89ubzIG+WJ0WsfFs1vRPYRo+dqxnKnO2PfBF8k8a+vBQefq2hMQ2CBKU/0I Mnazp974S7kRS3sDkRPy5fuYbB8WmddLRi3+VFaZNej+e9rjCEpC8JUhdLsXwe1MzC DtIfP/m2uxaGw== Received: from de02dwia024.internal.synopsys.com (de02dwia024.internal.synopsys.com [10.225.19.81]) by mailhost.synopsys.com (Postfix) with ESMTP id 20ABEA0061; Thu, 11 Feb 2021 09:12:58 +0000 (UTC) X-SNPS-Relay: synopsys.com From: Gustavo Pimentel To: dmaengine@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Vinod Koul , Dan Williams , Bjorn Helgaas Cc: Gustavo Pimentel Subject: [PATCH v5 04/15] PCI: Add pci_find_vsec_capability() to find a specific VSEC Date: Thu, 11 Feb 2021 10:12:37 +0100 Message-Id: <45b51292876f238afe3f6865113cd9d72d33e51a.1613034728.git.gustavo.pimentel@synopsys.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Add pci_find_vsec_capability() that crawls through the device config space searching in all Vendor-Specific Extended Capabilities for a particular capability ID. Vendor-Specific Extended Capability (VSEC) is a PCIe capability (acts like a wrapper) specified by PCI-SIG that allows the vendor to create their own and specific capability in the device config space. Signed-off-by: Gustavo Pimentel --- drivers/pci/pci.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/pci.h | 2 ++ include/uapi/linux/pci_regs.h | 6 ++++++ 3 files changed, 42 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b9fecc2..1307af6 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -693,6 +693,40 @@ u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap) EXPORT_SYMBOL_GPL(pci_find_ht_capability); /** + * pci_find_vsec_capability - Find a vendor-specific extended capability + * @dev: PCI device to query + * @cap: vendor-specific capability ID code + * + * Typically this function will be called by the pci driver, which passes + * through argument the 'struct pci_dev *' already pointing for the device + * config space that is associated with the vendor and device ID which will + * know which ID to search and what to do with it, however, it might be + * cases that this function could be called outside of this scope and + * therefore is the caller responsibility to check the vendor and/or + * device ID first. + * + * Returns the address of the vendor-specific structure that matches the + * requested capability ID code within the device's PCI configuration space + * or 0 if it does not find a match. + */ +u16 pci_find_vsec_capability(struct pci_dev *dev, int vsec_cap_id) +{ + u16 vsec = 0; + u32 header; + + while ((vsec = pci_find_next_ext_capability(dev, vsec, + PCI_EXT_CAP_ID_VNDR))) { + if (pci_read_config_dword(dev, vsec + PCI_VSEC_HDR, + &header) == PCIBIOS_SUCCESSFUL && + PCI_VSEC_CAP_ID(header) == vsec_cap_id) + return vsec; + } + + return 0; +} +EXPORT_SYMBOL_GPL(pci_find_vsec_capability); + +/** * pci_find_parent_resource - return resource region of parent bus of given * region * @dev: PCI device structure contains resources to be searched diff --git a/include/linux/pci.h b/include/linux/pci.h index b32126d..da6ab6a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1080,6 +1080,8 @@ struct pci_bus *pci_find_next_bus(const struct pci_bus *from); u64 pci_get_dsn(struct pci_dev *dev); +u16 pci_find_vsec_capability(struct pci_dev *dev, int vsec_cap_id); + struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from); struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index e709ae8..deae275 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -983,6 +983,12 @@ #define PCI_VSEC_HDR 4 /* extended cap - vendor-specific */ #define PCI_VSEC_HDR_LEN_SHIFT 20 /* shift for length field */ +/* Vendor-Specific Extended Capabilities */ +#define PCI_VSEC_HEADER 4 /* Vendor-Specific Header */ +#define PCI_VSEC_CAP_ID(x) ((x) & 0xffff) +#define PCI_VSEC_CAP_REV(x) (((x) >> 16) & 0xf) +#define PCI_VSEC_CAP_LEN(x) (((x) >> 20) & 0xfff) + /* SATA capability */ #define PCI_SATA_REGS 4 /* SATA REGs specifier */ #define PCI_SATA_REGS_MASK 0xF /* location - BAR#/inline */