Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756651Ab3H3OyO (ORCPT ); Fri, 30 Aug 2013 10:54:14 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:44966 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756023Ab3H3OyM (ORCPT ); Fri, 30 Aug 2013 10:54:12 -0400 X-AuditID: cbfee61a-b7f7a6d00000235f-f2-5220b21355f2 From: Sylwester Nawrocki To: linux-arm-kernel@lists.infradead.org Cc: linux@arm.linux.org.uk, mturquette@linaro.org, jiada_wang@mentor.com, kyungmin.park@samsung.com, myungjoo.ham@samsung.com, t.figa@samsung.com, g.liakhovetski@gmx.de, laurent.pinchart@ideasonboard.com, linux-kernel@vger.kernel.org, linux-mips@linux-mips.org, linux-sh@vger.kernel.org, Sylwester Nawrocki Subject: [PATCH v6 1/5] clk: Provide not locked variant of of_clk_get_from_provider() Date: Fri, 30 Aug 2013 16:53:18 +0200 Message-id: <1377874402-2944-2-git-send-email-s.nawrocki@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1377874402-2944-1-git-send-email-s.nawrocki@samsung.com> References: <1377874402-2944-1-git-send-email-s.nawrocki@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrELMWRmVeSWpSXmKPExsVy+t9jAV3hTQpBBhcfC1q83ziPyaLnT6XF 2aY37BadE5ewW2x6fI3V4vKuOWwWE6ZOYreY82cKs8Xty7wWTydcZLO43biCzeLwm3ZWi/Uz XrM48Hq0NPeweXz4GOcxu2Mmq8eda3vYPI6uXMvksXlJvcfur02MHn1bVjF6fN4kF8AZxWWT kpqTWZZapG+XwJVxYOsS9oI3chWrn/xjb2A8J9nFyMkhIWAi8eTCRHYIW0ziwr31bF2MXBxC AosYJe63XmKBcDqYJNadnQ9WxSZgKNF7tI8RxBYR0JCY0vWYHaSIWeAyk8SmL11gRcIC4RIr Lq8As1kEVCX2vdgD1sAr4CrxePoa1i5GDqB1ChJzJtmAhDkF3CQuTAPZzAm0zFVizolVjBMY eRcwMqxiFE0tSC4oTkrPNdQrTswtLs1L10vOz93ECA7ZZ1I7GFc2WBxiFOBgVOLhTViqECTE mlhWXJl7iFGCg1lJhPfjYqAQb0piZVVqUX58UWlOavEhRmkOFiVx3gOt1oFCAumJJanZqakF qUUwWSYOTqkGxtIuWa41zFftXqr8XS+e+qQu5tWkNtOI/V49mcqO9/ompR8pOBOjcK9Cxotb 8X5BxO+QjHvzAj8/09Uo3vkpss6RJdTZ/JgPu8TTsIcC6z7YpL7QVbcsZAg7N4VReLKy9N4Z 1feWhX81O8qibCMpsibQKev/1+6K8OW9iywe8HMsvdh/9sE8JZbijERDLeai4kQA1sdU6VUC AAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4053 Lines: 145 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 2db08c0..8f18564 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); @@ -2103,7 +2105,18 @@ 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) @@ -2147,9 +2160,9 @@ 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; @@ -2164,7 +2177,7 @@ 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); @@ -2173,24 +2186,33 @@ 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 -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/