From patchwork Tue Aug 26 14:57:39 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thierry Reding X-Patchwork-Id: 383098 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id E468E1400D7 for ; Wed, 27 Aug 2014 00:59:40 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755459AbaHZO5y (ORCPT ); Tue, 26 Aug 2014 10:57:54 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:42544 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932832AbaHZO5w (ORCPT ); Tue, 26 Aug 2014 10:57:52 -0400 Received: by mail-wi0-f172.google.com with SMTP id n3so4352693wiv.17 for ; Tue, 26 Aug 2014 07:57:50 -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:in-reply-to:references; bh=YILWlZ0eODTCr86lRPLFD6Qy5I8k1ua40TropWyM/Z8=; b=PHC2a8phKk+gEcpm4EusZcA/PXaB8/5e17yu3oE/CUGaH4Gh15XMj9q74vEIFjiEBm rjYAXug4XUD1OPUtnPhultBVs0Sdy1Ilv0hJbUfIhQ3NUebcmKViwHFrmy7GoIxLulB5 HzHp+bm7SNM9+ck/lAQ1VGS/58VwwMuZdb/L9JY8EW1+tXxArx6qwDmCZiytzyasxu1f 2psFzGAxOlnEpH3wQcIa8UIeggyPq4A68Hd7z3CKPPtHhbazflqUEFyx8SdR+SgHF8i4 n2bzw+7tzt0GHGaIT6UgLZI+pw+f6bHLEwDuOo0QqviQC88tAjptKDnKk6mQ4zgwQOf8 gE6w== X-Received: by 10.194.222.138 with SMTP id qm10mr5187897wjc.25.1409065070770; Tue, 26 Aug 2014 07:57:50 -0700 (PDT) Received: from localhost (port-7111.pppoe.wtnet.de. [84.46.27.226]) by mx.google.com with ESMTPSA id ew1sm8889773wjb.31.2014.08.26.07.57.49 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Aug 2014 07:57:50 -0700 (PDT) From: Thierry Reding To: Bjorn Helgaas Cc: Stephen Warren , linux-pci@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/6] resource: Add device-managed request/release_resource() Date: Tue, 26 Aug 2014 16:57:39 +0200 Message-Id: <1409065064-17617-2-git-send-email-thierry.reding@gmail.com> X-Mailer: git-send-email 2.0.4 In-Reply-To: <1409065064-17617-1-git-send-email-thierry.reding@gmail.com> References: <1409065064-17617-1-git-send-email-thierry.reding@gmail.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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. Acked-by: Tejun Heo Signed-off-by: Thierry Reding --- 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 60c5a3856ab7..46322019ab7d 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1245,6 +1245,76 @@ 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;