From patchwork Fri Mar 1 11:29:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Philipp Stanner X-Patchwork-Id: 13578376 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 27B73C5475B for ; Fri, 1 Mar 2024 11:30:23 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A18F810ECAA; Fri, 1 Mar 2024 11:30:20 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="GTp1uvbt"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2E01A10EC63 for ; Fri, 1 Mar 2024 11:30:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1709292618; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=x1vv8w5iQVUitgG0ysLWn1q06xCEf1/TkXPRyfO6KrE=; b=GTp1uvbtnnyUFfsAvK2rnroJtzGsqsQdzTopGVTMDida1XEUlLfdAsGwlfgLIrQm9JcWqc reoSdG12M1IKgJtdDDpk4MrdWmy9DCDUR2Fc7Dz4ZRMueQ+DMBoaQcOELnGq3ZqiogM/MA r3h8+w251VS5YwDlHws/hKA4tJa8k2k= Received: from mail-oi1-f199.google.com (mail-oi1-f199.google.com [209.85.167.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-533--X0dgZThOWKisy0KCjM2Rw-1; Fri, 01 Mar 2024 06:30:17 -0500 X-MC-Unique: -X0dgZThOWKisy0KCjM2Rw-1 Received: by mail-oi1-f199.google.com with SMTP id 5614622812f47-3c1aba536a1so155375b6e.1 for ; Fri, 01 Mar 2024 03:30:17 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709292616; x=1709897416; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=x1vv8w5iQVUitgG0ysLWn1q06xCEf1/TkXPRyfO6KrE=; b=Zy8P+8s+uHOS067gZtuYGtLFGWjDfTFD0M/nejDehbBOyHOLlrMD1KhE4IK/KxEJPW EOpqd9UUEI4LdqC3QjbUfHTgLS31eb8vSyiftYbZXd6yNGGMk1KTTMbq7BoqTp1QEY6K ODsFXxGVDQ87w6ixseRPxGMQJhZIoTH9bQbZ9RB8cH2m8t/S1zfUkVVpGOzL07KLFpc7 IUvCXwKYieUi56QtDSbqXaAeK5X0OWkD9x93TUXRVsFn5yU3jtHrSMIeNI55VqoFRN9u a4u1vaAd2GCJ9esre2oVsN+/Ny4rDb/ZXp/Hblaf9/FQCeMPK3KKTt3rJPR0KBS4KzUd eu0A== X-Gm-Message-State: AOJu0Yx1/vK3tIQczixNTZj9snWQvGfq/Ep8hN+jN9NiCPjc9R75zjxz NWEd7iYSw1YGgTRAG42bQPYO7wf7Ogxi8gxImmn6lVKeA22YsuImmR0r8Kv0Gq8fGOSEZy+eT2g x32cbW7mUfwX+63Lh/qxG38cTIM8TsDVJsLEs/d1IQznxZiJEVWSRRobCYuat0lYfLA== X-Received: by 2002:a05:6870:1b89:b0:21e:be91:ae48 with SMTP id hm9-20020a0568701b8900b0021ebe91ae48mr1405855oab.1.1709292616338; Fri, 01 Mar 2024 03:30:16 -0800 (PST) X-Google-Smtp-Source: AGHT+IEbFvAujWEWv1z6YVxUiGVIfr1SqZdnci7z1l0hJ/GNeV3/nbcF6AczulXgObryYZMXAxSD7g== X-Received: by 2002:a05:6870:1b89:b0:21e:be91:ae48 with SMTP id hm9-20020a0568701b8900b0021ebe91ae48mr1405843oab.1.1709292616009; Fri, 01 Mar 2024 03:30:16 -0800 (PST) Received: from pstanner-thinkpadt14sgen1.remote.csb (nat-pool-muc-t.redhat.com. [149.14.88.26]) by smtp.gmail.com with ESMTPSA id b1-20020ac86781000000b0042eb46d15bbsm1596239qtp.88.2024.03.01.03.30.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 Mar 2024 03:30:15 -0800 (PST) From: Philipp Stanner To: Hans de Goede , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Bjorn Helgaas , Sam Ravnborg , dakr@redhat.com Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Philipp Stanner Subject: [PATCH v4 03/10] PCI: Warn users about complicated devres nature Date: Fri, 1 Mar 2024 12:29:51 +0100 Message-ID: <20240301112959.21947-4-pstanner@redhat.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240301112959.21947-1-pstanner@redhat.com> References: <20240301112959.21947-1-pstanner@redhat.com> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The PCI region-request functions become managed functions when pcim_enable_device() has been called previously instead of pci_enable_device(). This has already caused bugs by confusing users, who came to believe that all pci functions, such as pci_iomap_range(), suddenly are managed that way. This is not the case. Add comments to the relevant functions' docstrings that warn users about this behavior. Signed-off-by: Philipp Stanner --- drivers/pci/iomap.c | 18 ++++++++++++++ drivers/pci/pci.c | 60 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 77 insertions(+), 1 deletion(-) diff --git a/drivers/pci/iomap.c b/drivers/pci/iomap.c index c9725428e387..ea3b9842132a 100644 --- a/drivers/pci/iomap.c +++ b/drivers/pci/iomap.c @@ -23,6 +23,11 @@ * * @maxlen specifies the maximum length to map. If you want to get access to * the complete BAR from offset to the end, pass %0 here. + * + * NOTE: + * This function is never managed, even if you initialized with + * pcim_enable_device(). + * If you need automatic cleanup, use pcim_iomap_range(). * */ void __iomem *pci_iomap_range(struct pci_dev *dev, int bar, @@ -63,6 +68,10 @@ EXPORT_SYMBOL(pci_iomap_range); * * @maxlen specifies the maximum length to map. If you want to get access to * the complete BAR from offset to the end, pass %0 here. + * + * NOTE: + * This function is never managed, even if you initialized with + * pcim_enable_device(). * */ void __iomem *pci_iomap_wc_range(struct pci_dev *dev, int bar, @@ -106,6 +115,11 @@ EXPORT_SYMBOL_GPL(pci_iomap_wc_range); * * @maxlen specifies the maximum length to map. If you want to get access to * the complete BAR without checking for its length first, pass %0 here. + * + * NOTE: + * This function is never managed, even if you initialized with + * pcim_enable_device(). + * If you need automatic cleanup, use pcim_iomap(). * */ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) { @@ -127,6 +141,10 @@ EXPORT_SYMBOL(pci_iomap); * * @maxlen specifies the maximum length to map. If you want to get access to * the complete BAR without checking for its length first, pass %0 here. + * + * NOTE: + * This function is never managed, even if you initialized with + * pcim_enable_device(). * */ void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen) { diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e01e316de1c3..26179611587b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3887,6 +3887,8 @@ EXPORT_SYMBOL(pci_release_region); * @res_name: Name to be associated with resource. * @exclusive: whether the region access is exclusive or not * + * Returns: 0 on success, negative error code on failure. + * * Mark the PCI region associated with PCI device @pdev BAR @bar as * being reserved by owner @res_name. Do not access any * address inside the PCI regions unless this call returns @@ -3898,6 +3900,13 @@ EXPORT_SYMBOL(pci_release_region); * * Returns 0 on success, or %EBUSY on error. A warning * message is also printed on failure. + * + * NOTE: + * This is a "hybrid" function: Its normally unmanaged, but becomes managed + * when pcim_enable_device() has been called in advance. + * This hybrid feature is DEPRECATED! If you need to implement a new pci + * function that does automatic cleanup, write a new pcim_* function that uses + * devres directly. */ static int __pci_request_region(struct pci_dev *pdev, int bar, const char *res_name, int exclusive) @@ -3946,6 +3955,8 @@ static int __pci_request_region(struct pci_dev *pdev, int bar, * @bar: BAR to be reserved * @res_name: Name to be associated with resource * + * Returns: 0 on success, negative error code on failure. + * * Mark the PCI region associated with PCI device @pdev BAR @bar as * being reserved by owner @res_name. Do not access any * address inside the PCI regions unless this call returns @@ -3953,6 +3964,12 @@ static int __pci_request_region(struct pci_dev *pdev, int bar, * * Returns 0 on success, or %EBUSY on error. A warning * message is also printed on failure. + * + * NOTE: + * This is a "hybrid" function: Its normally unmanaged, but becomes managed + * when pcim_enable_device() has been called in advance. + * This hybrid feature is DEPRECATED! If you want managed cleanup, use the + * pcim_* functions instead. */ int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name) { @@ -3978,6 +3995,13 @@ void pci_release_selected_regions(struct pci_dev *pdev, int bars) } EXPORT_SYMBOL(pci_release_selected_regions); +/* + * NOTE: + * This is a "hybrid" function: Its normally unmanaged, but becomes managed + * when pcim_enable_device() has been called in advance. + * This hybrid feature is DEPRECATED! If you want managed cleanup, use the + * pcim_* functions instead. + */ static int __pci_request_selected_regions(struct pci_dev *pdev, int bars, const char *res_name, int excl) { @@ -4003,6 +4027,14 @@ static int __pci_request_selected_regions(struct pci_dev *pdev, int bars, * @pdev: PCI device whose resources are to be reserved * @bars: Bitmask of BARs to be requested * @res_name: Name to be associated with resource + * + * Returns: 0 on success, negative error code on failure. + * + * NOTE: + * This is a "hybrid" function: Its normally unmanaged, but becomes managed + * when pcim_enable_device() has been called in advance. + * This hybrid feature is DEPRECATED! If you want managed cleanup, use the + * pcim_* functions instead. */ int pci_request_selected_regions(struct pci_dev *pdev, int bars, const char *res_name) @@ -4011,6 +4043,20 @@ int pci_request_selected_regions(struct pci_dev *pdev, int bars, } EXPORT_SYMBOL(pci_request_selected_regions); +/** + * pci_request_selected_regions_exclusive - Request regions exclusively + * @pdev: PCI device to request regions from + * @bars: bit mask of bars to request + * @res_name: name to be associated with the requests + * + * Returns: 0 on success, negative error code on failure. + * + * NOTE: + * This is a "hybrid" function: Its normally unmanaged, but becomes managed + * when pcim_enable_device() has been called in advance. + * This hybrid feature is DEPRECATED! If you want managed cleanup, use the + * pcim_* functions instead. + */ int pci_request_selected_regions_exclusive(struct pci_dev *pdev, int bars, const char *res_name) { @@ -4028,7 +4074,6 @@ EXPORT_SYMBOL(pci_request_selected_regions_exclusive); * successful call to pci_request_regions(). Call this function only * after all use of the PCI regions has ceased. */ - void pci_release_regions(struct pci_dev *pdev) { pci_release_selected_regions(pdev, (1 << PCI_STD_NUM_BARS) - 1); @@ -4060,6 +4105,8 @@ EXPORT_SYMBOL(pci_request_regions); * @pdev: PCI device whose resources are to be reserved * @res_name: Name to be associated with resource. * + * Returns: 0 on success, negative error code on failure. + * * Mark all PCI regions associated with PCI device @pdev as being reserved * by owner @res_name. Do not access any address inside the PCI regions * unless this call returns successfully. @@ -4069,6 +4116,12 @@ EXPORT_SYMBOL(pci_request_regions); * * Returns 0 on success, or %EBUSY on error. A warning message is also * printed on failure. + * + * NOTE: + * This is a "hybrid" function: Its normally unmanaged, but becomes managed + * when pcim_enable_device() has been called in advance. + * This hybrid feature is DEPRECATED! If you want managed cleanup, use the + * pcim_* functions instead. */ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name) { @@ -4400,6 +4453,11 @@ void pci_disable_parity(struct pci_dev *dev) * @enable: boolean: whether to enable or disable PCI INTx * * Enables/disables PCI INTx for device @pdev + * + * NOTE: + * This is a "hybrid" function: Its normally unmanaged, but becomes managed + * when pcim_enable_device() has been called in advance. + * This hybrid feature is DEPRECATED! */ void pci_intx(struct pci_dev *pdev, int enable) {