From patchwork Fri Aug 25 06:27:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sui Jingfeng X-Patchwork-Id: 13365075 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5FFF2C71133 for ; Fri, 25 Aug 2023 06:27:39 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4583310E602; Fri, 25 Aug 2023 06:27:37 +0000 (UTC) Received: from out-54.mta1.migadu.com (out-54.mta1.migadu.com [95.215.58.54]) by gabe.freedesktop.org (Postfix) with ESMTPS id 67A3310E109 for ; Fri, 25 Aug 2023 06:27:30 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1692944848; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mHmggkPoB6PVkfuQyqjiEi6pSxLj7NQb/O/moIUqI3Q=; b=gGlORSRXYl4gFoXXTmBWXlDv9M59x4zb6DH/yv9Me/t4nLyEdmV9ka2HJBT95q/hEQ5/qp o3h5Y41uekJhozAijzpufcmcPJKQeg9tw+djHsg1V7nZ/b88TT009/f84nAk9E2roApfBk Gc+swNB9ZjDJuDdVymWrbVncDrt8mN0= From: Sui Jingfeng To: Bjorn Helgaas Subject: [PATCH 1/5] PCI: Add the pci_get_base_class() helper Date: Fri, 25 Aug 2023 14:27:10 +0800 Message-Id: <20230825062714.6325-2-sui.jingfeng@linux.dev> In-Reply-To: <20230825062714.6325-1-sui.jingfeng@linux.dev> References: <20230825062714.6325-1-sui.jingfeng@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alsa-devel@alsa-project.org, Sui Jingfeng , nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, linux-pci@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Sui Jingfeng There is no function that can be used to get all PCI(e) devices in a system by matching against its the PCI base class code only, while keep the sub-class code and the programming interface ignored. Therefore, add the pci_get_base_class() function to suit the need. For example, if an application want to process all PCI(e) display devices in a system, it can achieve such goal by writing the code as following: pdev = NULL; do { pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev); if (!pdev) break; do_something_for_pci_display_device(pdev); } while (1); Cc: Bjorn Helgaas Signed-off-by: Sui Jingfeng --- drivers/pci/search.c | 31 +++++++++++++++++++++++++++++++ include/linux/pci.h | 5 +++++ 2 files changed, 36 insertions(+) diff --git a/drivers/pci/search.c b/drivers/pci/search.c index b4c138a6ec02..53840634fbfc 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -363,6 +363,37 @@ struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from) } EXPORT_SYMBOL(pci_get_class); +/** + * pci_get_base_class - searching for a PCI device by matching against the base class code only + * @class: search for a PCI device with this base class code + * @from: Previous PCI device found in search, or %NULL for new search. + * + * Iterates through the list of known PCI devices. If a PCI device is found + * with a matching base class code, the reference count to the device is + * incremented. See pci_match_one_device() to figure out how does this works. + * A new search is initiated by passing %NULL as the @from argument. + * Otherwise if @from is not %NULL, searches continue from next device on the + * global list. The reference count for @from is always decremented if it is + * not %NULL. + * + * Returns: + * A pointer to a matched PCI device, %NULL Otherwise. + */ +struct pci_dev *pci_get_base_class(unsigned int class, struct pci_dev *from) +{ + struct pci_device_id id = { + .vendor = PCI_ANY_ID, + .device = PCI_ANY_ID, + .subvendor = PCI_ANY_ID, + .subdevice = PCI_ANY_ID, + .class_mask = 0xFF0000, + .class = class << 16, + }; + + return pci_get_dev_by_id(&id, from); +} +EXPORT_SYMBOL(pci_get_base_class); + /** * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not. * @ids: A pointer to a null terminated list of struct pci_device_id structures diff --git a/include/linux/pci.h b/include/linux/pci.h index 71c85380676c..486ad959e1f9 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1180,6 +1180,8 @@ struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn); struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus, unsigned int devfn); struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from); +struct pci_dev *pci_get_base_class(unsigned int class, struct pci_dev *from); + int pci_dev_present(const struct pci_device_id *ids); int pci_bus_read_config_byte(struct pci_bus *bus, unsigned int devfn, @@ -1896,6 +1898,9 @@ static inline struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from) { return NULL; } +static inline struct pci_dev *pci_get_base_class(unsigned int class, + struct pci_dev *from) +{ return NULL; } static inline int pci_dev_present(const struct pci_device_id *ids) { return 0; }