From patchwork Wed Dec 4 17:12:04 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Sylwester Nawrocki/Kernel \\(PLT\\) /SRPOL/Staff Engineer/Samsung Electronics" X-Patchwork-Id: 3283911 Return-Path: X-Original-To: patchwork-linux-arm@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 C66669F37A for ; Wed, 4 Dec 2013 17:14:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 93C73204EC for ; Wed, 4 Dec 2013 17:14:31 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5751D204DF for ; Wed, 4 Dec 2013 17:14:30 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VoG1Y-00064N-8U; Wed, 04 Dec 2013 17:14:08 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VoG1O-0002qB-8T; Wed, 04 Dec 2013 17:13:58 +0000 Received: from mailout2.samsung.com ([203.254.224.25]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VoG1K-0002nH-6b for linux-arm-kernel@lists.infradead.org; Wed, 04 Dec 2013 17:13:54 +0000 Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MXA00FRJL6KWYB0@mailout2.samsung.com> for linux-arm-kernel@lists.infradead.org; Thu, 05 Dec 2013 02:13:32 +0900 (KST) X-AuditID: cbfee61a-b7f796d000004313-95-529f62bc12b7 Received: from epmmp1.local.host ( [203.254.227.16]) by epcpsbgm1.samsung.com (EPCPMTA) with SMTP id A6.89.17171.CB26F925; Thu, 05 Dec 2013 02:13:32 +0900 (KST) Received: from amdc1344.digital.local ([106.116.147.32]) by mmp1.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0MXA00HNVL4BBJ20@mmp1.samsung.com>; Thu, 05 Dec 2013 02:13:32 +0900 (KST) From: Sylwester Nawrocki To: mturquette@linaro.org, linux-arm-kernel@lists.infradead.org Subject: [RESEND PATCH v7 2/5] clk: Provide not locked variant of of_clk_get_from_provider() Date: Wed, 04 Dec 2013 18:12:04 +0100 Message-id: <1386177127-2894-3-git-send-email-s.nawrocki@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1386177127-2894-1-git-send-email-s.nawrocki@samsung.com> References: <1386177127-2894-1-git-send-email-s.nawrocki@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrMLMWRmVeSWpSXmKPExsVy+t9jAd09SfODDBZv4rfo+VNpcbbpDbtF 58Ql7BabHl9jtbi8aw6bRc+GrawWty/zWjydcJHN4vCbdlYHTo+W5h42j9kdM1k97lzbw+ax eUm9x+6vTYwefVtWMXp83iQXwB7FZZOSmpNZllqkb5fAlfHn1TqWgjdyFX3PxBoYz0l2MXJy SAiYSHw//IcRwhaTuHBvPVsXIxeHkMAiRolnU5dAOR1MEpu23GACqWITMJToPdoH1iEiYC/R 3vICrIhZ4C6jxPNzD4ESHBzCAnESZ3ZngNSwCKhK3Nu4khnE5hVwldjadIsZpERCQEFiziQb kDCngJvEvhlbWEBsIaCS8zsfs09g5F3AyLCKUTS1ILmgOCk911CvODG3uDQvXS85P3cTIzjo nkntYFzZYHGIUYCDUYmH90Xi/CAh1sSy4srcQ4wSHMxKIryTA4FCvCmJlVWpRfnxRaU5qcWH GKU5WJTEeQ+0WgcKCaQnlqRmp6YWpBbBZJk4OKUaGKULcnOsmJvjJU7P+Z1amL/w2qWs5S0P uBgtPda7HV0XzyNVufKstPcrk1UZdhq5GYqTp39dVZ3RNuH8As+3he9L9+mmN50ON5ryIfdK 5kIV/oDyeW2Pjv2d8ZuHqVo9Jo9tnuTbz++09yTs/3bBy+62i2roC+eA+sxFxz594r4XsWbj YyHxBUosxRmJhlrMRcWJAFp1K542AgAA X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131204_121354_470779_54B5D27E X-CRM114-Status: GOOD ( 15.46 ) X-Spam-Score: -6.9 (------) Cc: linux@arm.linux.org.uk, jiada_wang@mentor.com, linux-kernel@vger.kernel.org, kyungmin.park@samsung.com, laurent.pinchart@ideasonboard.com, Sylwester Nawrocki , linux-media@vger.kernel.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, 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 Add helper functions for the of_clk_providers list locking and an unlocked variant of of_clk_get_from_provider(). These functions are intended to be used in the clkdev to avoid race condition in the device tree based clock look up in clk_get(). Signed-off-by: Sylwester Nawrocki Signed-off-by: Kyungmin Park Acked-by: Russell King --- Changes since v3: - none. Changes since v2: - fixed typo in clk.h. Changes since v1: - moved the function declaractions to a local header. --- drivers/clk/clk.c | 38 ++++++++++++++++++++++++++++++-------- drivers/clk/clk.h | 16 ++++++++++++++++ 2 files changed, 46 insertions(+), 8 deletions(-) create mode 100644 drivers/clk/clk.h diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 77fcd06..c687dc8 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -21,6 +21,8 @@ #include #include +#include "clk.h" + static DEFINE_SPINLOCK(enable_lock); static DEFINE_MUTEX(prepare_lock); @@ -2111,7 +2113,18 @@ static const struct of_device_id __clk_of_table_sentinel __used __section(__clk_of_table_end); static LIST_HEAD(of_clk_providers); -static DEFINE_MUTEX(of_clk_lock); +static DEFINE_MUTEX(of_clk_mutex); + +/* of_clk_provider list locking helpers */ +void of_clk_lock(void) +{ + mutex_lock(&of_clk_mutex); +} + +void of_clk_unlock(void) +{ + mutex_unlock(&of_clk_mutex); +} struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, void *data) @@ -2155,9 +2168,9 @@ int of_clk_add_provider(struct device_node *np, cp->data = data; cp->get = clk_src_get; - mutex_lock(&of_clk_lock); + mutex_lock(&of_clk_mutex); list_add(&cp->link, &of_clk_providers); - mutex_unlock(&of_clk_lock); + mutex_unlock(&of_clk_mutex); pr_debug("Added clock from %s\n", np->full_name); return 0; @@ -2172,7 +2185,7 @@ void of_clk_del_provider(struct device_node *np) { struct of_clk_provider *cp; - mutex_lock(&of_clk_lock); + mutex_lock(&of_clk_mutex); list_for_each_entry(cp, &of_clk_providers, link) { if (cp->node == np) { list_del(&cp->link); @@ -2181,24 +2194,33 @@ void of_clk_del_provider(struct device_node *np) break; } } - mutex_unlock(&of_clk_lock); + mutex_unlock(&of_clk_mutex); } EXPORT_SYMBOL_GPL(of_clk_del_provider); -struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) +struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) { struct of_clk_provider *provider; struct clk *clk = ERR_PTR(-ENOENT); /* Check if we have such a provider in our array */ - mutex_lock(&of_clk_lock); list_for_each_entry(provider, &of_clk_providers, link) { if (provider->node == clkspec->np) clk = provider->get(clkspec, provider->data); if (!IS_ERR(clk)) break; } - mutex_unlock(&of_clk_lock); + + return clk; +} + +struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) +{ + struct clk *clk; + + mutex_lock(&of_clk_mutex); + clk = __of_clk_get_from_provider(clkspec); + mutex_unlock(&of_clk_mutex); return clk; } diff --git a/drivers/clk/clk.h b/drivers/clk/clk.h new file mode 100644 index 0000000..795cc9f --- /dev/null +++ b/drivers/clk/clk.h @@ -0,0 +1,16 @@ +/* + * linux/drivers/clk/clk.h + * + * Copyright (C) 2013 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) +struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec); +void of_clk_lock(void); +void of_clk_unlock(void); +#endif