From patchwork Fri Aug 1 12:15:10 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thierry Reding X-Patchwork-Id: 4662591 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 5AA899F36A for ; Fri, 1 Aug 2014 12:15:45 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 774E420218 for ; Fri, 1 Aug 2014 12:15:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 758FB20219 for ; Fri, 1 Aug 2014 12:15:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754559AbaHAMPU (ORCPT ); Fri, 1 Aug 2014 08:15:20 -0400 Received: from mail-wg0-f45.google.com ([74.125.82.45]:63921 "EHLO mail-wg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751008AbaHAMPS (ORCPT ); Fri, 1 Aug 2014 08:15:18 -0400 Received: by mail-wg0-f45.google.com with SMTP id x12so4284595wgg.16 for ; Fri, 01 Aug 2014 05:15:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=jFxSWooqijWFl5cdT1lmUSlBtbGPQVARELyay2kLUJk=; b=xR4ckVi6aJSDMw/rdhLXuGG2TE97xz2pzp6EGWLNczRHGRuYaIqKuGXilsgnNOTq3L a/ttmxuigiQk6j/wwBxeKOz/sSTCZYRnd4QGW1gSKBYfnBcBMT98RCVlZ33WKoPTdNn0 QmUm4eaPVTtUfAxf2xCOvwQ+0OsBwZ4i1YLN1z7tl85HTDeVR5nPvfeFQa9HT1v/+zGk 8Z7wzMnLbm28HfxJpDWlpLRPV6dGgh7HKQ4l46xqf8LcimiMTfHjaKb2zZgmYccXScf7 53X2gJ8CaApJ849a1UiDLC7UTbK5LpbhTz4+MKJdNUJijpREk1H51ygMI6oMZ5jHJBaS 0TDQ== X-Received: by 10.180.78.100 with SMTP id a4mr6342523wix.36.1406895314183; Fri, 01 Aug 2014 05:15:14 -0700 (PDT) Received: from localhost (port-22661.pppoe.wtnet.de. [46.59.150.52]) by mx.google.com with ESMTPSA id ca8sm20596959wjc.0.2014.08.01.05.15.13 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Aug 2014 05:15:13 -0700 (PDT) From: Thierry Reding To: Bjorn Helgaas , Tejun Heo Cc: Stephen Warren , linux-pci@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/2] resource: Add device-managed request/release_resource() Date: Fri, 1 Aug 2014 14:15:10 +0200 Message-Id: <1406895311-18869-1-git-send-email-thierry.reding@gmail.com> X-Mailer: git-send-email 2.0.3 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Thierry Reding Provide device-managed implementations of the request_resource() and release_resource() functions. Upon failure to request a resource, the new devm_request_resource() function will output an error message for consistent error reporting. Signed-off-by: Thierry Reding Acked-by: Tejun Heo --- Changes in v2: - use more natural flow for error handling - don't needlessly check for NULL pointers Documentation/driver-model/devres.txt | 2 + include/linux/ioport.h | 5 +++ kernel/resource.c | 70 +++++++++++++++++++++++++++++++++++ 3 files changed, 77 insertions(+) diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index d14710b04439..befc3fe12ba6 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -264,8 +264,10 @@ IIO IO region devm_release_mem_region() devm_release_region() + devm_release_resource() devm_request_mem_region() devm_request_region() + devm_request_resource() IOMAP devm_ioport_map() diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 142ec544167c..2c5250222278 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -215,6 +215,11 @@ static inline int __deprecated check_region(resource_size_t s, /* Wrappers for managed devices */ struct device; + +extern int devm_request_resource(struct device *dev, struct resource *root, + struct resource *new); +extern void devm_release_resource(struct device *dev, struct resource *new); + #define devm_request_region(dev,start,n,name) \ __devm_request_region(dev, &ioport_resource, (start), (n), (name)) #define devm_request_mem_region(dev,start,n,name) \ diff --git a/kernel/resource.c b/kernel/resource.c index da14b8d09296..ca24f19f9d18 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1248,6 +1248,76 @@ int release_mem_region_adjustable(struct resource *parent, /* * Managed region resource */ +static void devm_resource_release(struct device *dev, void *ptr) +{ + struct resource **r = ptr; + + release_resource(*r); +} + +/** + * devm_request_resource() - request and reserve an I/O or memory resource + * @dev: device for which to request the resource + * @root: root of the resource tree from which to request the resource + * @new: descriptor of the resource to request + * + * This is a device-managed version of request_resource(). There is usually + * no need to release resources requested by this function explicitly since + * that will be taken care of when the device is unbound from its driver. + * If for some reason the resource needs to be released explicitly, because + * of ordering issues for example, drivers must call devm_release_resource() + * rather than the regular release_resource(). + * + * When a conflict is detected between any existing resources and the newly + * requested resource, an error message will be printed. + * + * Returns 0 on success or a negative error code on failure. + */ +int devm_request_resource(struct device *dev, struct resource *root, + struct resource *new) +{ + struct resource *conflict, **ptr; + + ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + *ptr = new; + + conflict = request_resource_conflict(root, new); + if (conflict) { + dev_err(dev, "resource collision: %pR conflicts with %s %pR\n", + new, conflict->name, conflict); + devres_free(ptr); + return -EBUSY; + } + + devres_add(dev, ptr); + return 0; +} +EXPORT_SYMBOL(devm_request_resource); + +static int devm_resource_match(struct device *dev, void *res, void *data) +{ + struct resource **ptr = res; + + return *ptr == data; +} + +/** + * devm_release_resource() - release a previously requested resource + * @dev: device for which to release the resource + * @new: descriptor of the resource to release + * + * Releases a resource previously requested using devm_request_resource(). + */ +void devm_release_resource(struct device *dev, struct resource *new) +{ + WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match, + new)); +} +EXPORT_SYMBOL(devm_release_resource); + struct region_devres { struct resource *parent; resource_size_t start;