From patchwork Sat Aug 24 15:19:45 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sylwester Nawrocki X-Patchwork-Id: 2849225 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 885419F239 for ; Sat, 24 Aug 2013 15:21:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A28EA2026F for ; Sat, 24 Aug 2013 15:21:36 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9262720272 for ; Sat, 24 Aug 2013 15:21:35 +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 1VDFef-0007yo-9z; Sat, 24 Aug 2013 15:21:33 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VDFed-0001FY-3W; Sat, 24 Aug 2013 15:21:31 +0000 Received: from mail-ee0-x22a.google.com ([2a00:1450:4013:c00::22a]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VDFeZ-0001ES-T8 for linux-arm-kernel@lists.infradead.org; Sat, 24 Aug 2013 15:21:28 +0000 Received: by mail-ee0-f42.google.com with SMTP id b45so803549eek.29 for ; Sat, 24 Aug 2013 08:21:06 -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=J5S7P41X70UuN1Rfy0Zef7vnTwHZ9o5DIJHfHr2+p40=; b=tuLDMIt6VHxildAQLpnwT6xakPNzfgF9js8XM+6tVrDCpwUEi0Jo7Zxk2BTRcwMQLc OkzU8YhwUtUirjymyXs+fV7B8FLO36Lbe4godd7up3pTrJeURSfQ0qg1LDYfD767YwD8 0S7S/K0uFpfhn2k371U9bTEi3NzpoWcidfJYrlF2NenxldpIH37VFA2VQrVC2vGYckkK Iaq9KvcxziKGBxPtrE5W+s0Wlcar3Zt1rDPus1foHmXar2b58cTmDvDo/57MVWjc4oAL l0kA1QrjhX5S4vCnSLUuJaDKc6QWsVhIf1RtlocEb66sw3f3d9pVrH0VfrnV/xSQKgCJ gQ6g== X-Received: by 10.15.27.133 with SMTP id p5mr519893eeu.65.1377357665995; Sat, 24 Aug 2013 08:21:05 -0700 (PDT) Received: from localhost.localdomain (093105185086.warszawa.vectranet.pl. [93.105.185.86]) by mx.google.com with ESMTPSA id x47sm7415825eea.16.1969.12.31.16.00.00 (version=TLSv1 cipher=RC4-SHA bits=128/128); Sat, 24 Aug 2013 08:21:05 -0700 (PDT) From: Sylwester Nawrocki To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 1/5] clk: Provide not locked variant of of_clk_get_from_provider() Date: Sat, 24 Aug 2013 17:19:45 +0200 Message-Id: <1377357589-13242-2-git-send-email-s.nawrocki@samsung.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1377357589-13242-1-git-send-email-s.nawrocki@samsung.com> References: <1377357589-13242-1-git-send-email-s.nawrocki@samsung.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130824_112128_085611_DC171D80 X-CRM114-Status: GOOD ( 16.40 ) X-Spam-Score: -2.0 (--) Cc: linux-mips@linux-mips.org, mturquette@linaro.org, linux-sh@vger.kernel.org, jiada_wang@mentor.com, t.figa@samsung.com, laurent.pinchart@ideasonboard.com, linux-kernel@vger.kernel.org, ralf@linux-mips.org, kyungmin.park@samsung.com, broonie@kernel.org, vapier@gentoo.org, myungjoo.ham@samsung.com, s.nawrocki@samsung.com, uclinux-dist-devel@blackfin.uclinux.org, linux@arm.linux.org.uk, shawn.guo@linaro.org, LW@KARO-electronics.de, g.liakhovetski@gmx.de, sebastian.hesselbarth@gmail.com 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=-6.9 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, 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 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 bc02037..f46444f 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); @@ -2097,7 +2099,18 @@ 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) @@ -2141,9 +2154,9 @@ 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; @@ -2158,7 +2171,7 @@ 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); @@ -2167,24 +2180,33 @@ 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