From patchwork Tue Jan 23 09:43:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Philipp Stanner X-Patchwork-Id: 13527074 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 4968EC47258 for ; Tue, 23 Jan 2024 09:44:59 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6FC1A10E719; Tue, 23 Jan 2024 09:44:56 +0000 (UTC) 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 CE7AD10E716 for ; Tue, 23 Jan 2024 09:44:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1706003094; 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=3EoIsZMzaud9t26sivTeCHJdwdosgvCL2VSONhiwz3c=; b=bzO4KYR+HIGw1CeigCrcbXMdijwZbVwp+77kd/sdotBPtz9PWoQr2nkgR705QvY7XR1it8 Zzs7zNGmSIwU/aSPFV3Hv9p79mtk0iu0TzFGZniShd0AOt3XJk/ZQTonRZqqHQejlK38Vy lBHYE0QAUKR+A0yjUNK9zv04BtA6ILg= Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-317-Bdcklg15M8yw4lAyfb4M3w-1; Tue, 23 Jan 2024 04:44:52 -0500 X-MC-Unique: Bdcklg15M8yw4lAyfb4M3w-1 Received: by mail-qk1-f198.google.com with SMTP id af79cd13be357-781314b6298so128252985a.1 for ; Tue, 23 Jan 2024 01:44:52 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706003092; x=1706607892; 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=3EoIsZMzaud9t26sivTeCHJdwdosgvCL2VSONhiwz3c=; b=CLo6eb6ZfAG/D0Scgh1oK5xpcAFL3y14a9EA/gYm7RvMT9Y56CoRZT8fhKlOJCMavu a79GctcGE0PON7bLSgJNOdeGNvGjZYi+ceChBM6cvqJszmeLB1MVm9zeVrGebIqIyjBK bRBlFSqnCf7wi5gU7NUyyFfq2hMYCbqLKBatWwLTfSmk5+8D64+vB22aoAMKdor0gfX9 me8EmbkXn0VcfnsBTWZ5FM7V3fUKYrw2FwR+1a/DaCLsT6BhOaU2GLuaKZGIWKMqIIG+ sWA/zyDIfq6M1xfJ9bCH6os4pAFJnnZak+BGzQtes236K/bf2pVVKR5nXd/RMB6BZuur UOyg== X-Gm-Message-State: AOJu0YykCWfxj8s6IV/guzoNn7oZd7JuYabpJZdgbx0BvhrnzsLl5/xM xRNY9conGGghRXuFFo5R5z2pyUsSwZ0YESdkQ8nA9lilCGzIZuTVOmmUwogaSROABi19r+QqZny 00jaV+HRTRHn2VjQnM99v4JnPDhv7tVyLo/c8glfO2fS4FyBQ56QoZg9O0mgwm+SSsQ== X-Received: by 2002:a05:6214:c6e:b0:686:90f0:2a33 with SMTP id t14-20020a0562140c6e00b0068690f02a33mr5644869qvj.5.1706003091671; Tue, 23 Jan 2024 01:44:51 -0800 (PST) X-Google-Smtp-Source: AGHT+IHPwBecVC6FieQ1xp9U2Y6NBmb5GNR/o+qtX9gU0WfvrCMFDX+wPNNnUyTl0yQMJj1YP7+7Og== X-Received: by 2002:a05:6214:c6e:b0:686:90f0:2a33 with SMTP id t14-20020a0562140c6e00b0068690f02a33mr5644861qvj.5.1706003091343; Tue, 23 Jan 2024 01:44:51 -0800 (PST) Received: from pstanner-thinkpadt14sgen1.muc.redhat.com (nat-pool-muc-t.redhat.com. [149.14.88.26]) by smtp.gmail.com with ESMTPSA id nc5-20020a0562142dc500b00685e2ffcaf5sm2958704qvb.38.2024.01.23.01.44.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jan 2024 01:44:51 -0800 (PST) From: Philipp Stanner To: Jonathan Corbet , Hans de Goede , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Bjorn Helgaas , Philipp Stanner , Sam Ravnborg , dakr@redhat.com Subject: [PATCH v2 03/10] PCI: warn users about complicated devres nature Date: Tue, 23 Jan 2024 10:43:00 +0100 Message-ID: <20240123094317.15958-4-pstanner@redhat.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240123094317.15958-1-pstanner@redhat.com> References: <20240123094317.15958-1-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: , Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org 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 b7faf22ec8f5..0b7fcc2f7a49 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 2899df77a285..7ca860acf351 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3907,6 +3907,8 @@ 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 @@ -3918,6 +3920,13 @@ 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) @@ -3966,6 +3975,8 @@ 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 @@ -3973,6 +3984,12 @@ 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) { @@ -3998,6 +4015,13 @@ 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) { @@ -4023,6 +4047,14 @@ 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) @@ -4031,6 +4063,20 @@ 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) { @@ -4048,7 +4094,6 @@ 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); @@ -4080,6 +4125,8 @@ 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. @@ -4089,6 +4136,12 @@ 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) { @@ -4420,6 +4473,11 @@ 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) {