From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C477C1FC10C; Wed, 5 Mar 2025 08:42:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741164139; cv=none; b=RfHZAnaIrpPI0VLDv/YEnPIMIb1K6YihWrcHbpVnbjnaxBT1Csv3H7S/EupLuYCeszC98xqv0i+ZnGKZw3H03ocjlm6WiQNLk0DOuOqEp3ere20lpiW7ym9jJ4EO1IAFs0Cx4WKyAUOrNqa7CRqsSXWXmsGV8kfA1BZ0Z+9HcWE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741164139; c=relaxed/simple; bh=ip+xY+hrtB8A1Wl/yTyq2dvEsFrmdQG6g+oTOPZIVoE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=FfW8ZYFup3XNBBBoIE2KBWtfQyu7TkfZUPchsHj85sEvKzfj7CtFCxPO32RyGKtUbIAvm/0Tct1W/kKkal3Iyj9xkJWP7p/hvNBFkBHs8nDlEpYB9OphJzU9XxBWC+JusQQgnHhYcZfOzrvZSkY2WdPMFUP3Zwl/VpvuzMMGdro= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id ED9E4FEC; Wed, 5 Mar 2025 00:42:28 -0800 (PST) Received: from [10.57.64.200] (unknown [10.57.64.200]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7D35A3F66E; Wed, 5 Mar 2025 00:42:13 -0800 (PST) Message-ID: <7a1cac10-b065-4b4c-b048-10d6b4132f3d@arm.com> Date: Wed, 5 Mar 2025 08:42:11 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 4/4] drivers/thermal/exymos: Use guard notation when acquiring mutex To: Anand Moon Cc: Bartlomiej Zolnierkiewicz , "open list:SAMSUNG THERMAL DRIVER" , "open list:SAMSUNG THERMAL DRIVER" , Alim Akhtar , Daniel Lezcano , open list , "moderated list:ARM/SAMSUNG S3C, S5P AND EXYNOS ARM ARCHITECTURES" , Zhang Rui , Krzysztof Kozlowski , "Rafael J. Wysocki" References: <20250216195850.5352-1-linux.amoon@gmail.com> <20250216195850.5352-5-linux.amoon@gmail.com> Content-Language: en-US From: Lukasz Luba In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/4/25 12:20, Anand Moon wrote: > Hi Lukasz, > > On Sat, 1 Mar 2025 at 00:06, Anand Moon wrote: >> >> Hi Lukasz, >> >> On Fri, 28 Feb 2025 at 22:58, Lukasz Luba wrote: >>> >>> >>> >>> On 2/16/25 19:58, Anand Moon wrote: >>>> Using guard notation makes the code more compact and error handling >>>> more robust by ensuring that mutexes are released in all code paths >>>> when control leaves critical section. >>>> >>>> Signed-off-by: Anand Moon >>>> --- >>>> v3: new patch >>>> --- >>>> drivers/thermal/samsung/exynos_tmu.c | 21 +++++++-------------- >>>> 1 file changed, 7 insertions(+), 14 deletions(-) >>>> >>>> diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c >>>> index fe090c1a93ab..a34ba3858d64 100644 >>>> --- a/drivers/thermal/samsung/exynos_tmu.c >>>> +++ b/drivers/thermal/samsung/exynos_tmu.c >>>> @@ -256,7 +256,7 @@ static int exynos_tmu_initialize(struct platform_device *pdev) >>>> unsigned int status; >>>> int ret = 0; >>>> >>>> - mutex_lock(&data->lock); >>>> + guard(mutex)(&data->lock); >>>> clk_enable(data->clk); >>>> clk_enable(data->clk_sec); >>>> >>>> @@ -270,7 +270,6 @@ static int exynos_tmu_initialize(struct platform_device *pdev) >>>> >>>> clk_disable(data->clk_sec); >>>> clk_disable(data->clk); >>>> - mutex_unlock(&data->lock); >>>> >>>> return ret; >>>> } >>>> @@ -292,13 +291,12 @@ static int exynos_thermal_zone_configure(struct platform_device *pdev) >>>> return ret; >>>> } >>>> >>>> - mutex_lock(&data->lock); >>>> + guard(mutex)(&data->lock); >>>> clk_enable(data->clk); >>>> >>>> data->tmu_set_crit_temp(data, temp / MCELSIUS); >>>> >>>> clk_disable(data->clk); >>>> - mutex_unlock(&data->lock); >>>> >>>> return 0; >>>> } >>>> @@ -325,12 +323,11 @@ static void exynos_tmu_control(struct platform_device *pdev, bool on) >>>> { >>>> struct exynos_tmu_data *data = platform_get_drvdata(pdev); >>>> >>>> - mutex_lock(&data->lock); >>>> + guard(mutex)(&data->lock); >>>> clk_enable(data->clk); >>>> data->tmu_control(pdev, on); >>>> data->enabled = on; >>>> clk_disable(data->clk); >>>> - mutex_unlock(&data->lock); >>>> } >>>> >>>> static void exynos_tmu_update_bit(struct exynos_tmu_data *data, int reg_off, >>>> @@ -645,7 +642,7 @@ static int exynos_get_temp(struct thermal_zone_device *tz, int *temp) >>>> */ >>>> return -EAGAIN; >>>> >>>> - mutex_lock(&data->lock); >>>> + guard(mutex)(&data->lock); >>>> clk_enable(data->clk); >>>> >>>> value = data->tmu_read(data); >>>> @@ -655,7 +652,6 @@ static int exynos_get_temp(struct thermal_zone_device *tz, int *temp) >>>> *temp = code_to_temp(data, value) * MCELSIUS; >>>> >>>> clk_disable(data->clk); >>>> - mutex_unlock(&data->lock); >>>> >>>> return ret; >>>> } >>>> @@ -720,11 +716,10 @@ static int exynos_tmu_set_emulation(struct thermal_zone_device *tz, int temp) >>>> if (temp && temp < MCELSIUS) >>>> goto out; >>>> >>>> - mutex_lock(&data->lock); >>>> + guard(mutex)(&data->lock); >>>> clk_enable(data->clk); >>>> data->tmu_set_emulation(data, temp); >>>> clk_disable(data->clk); >>>> - mutex_unlock(&data->lock); >>>> return 0; >>>> out: >>>> return ret; >>>> @@ -760,14 +755,13 @@ static irqreturn_t exynos_tmu_threaded_irq(int irq, void *id) >>>> >>>> thermal_zone_device_update(data->tzd, THERMAL_EVENT_UNSPECIFIED); >>>> >>>> - mutex_lock(&data->lock); >>>> + guard(mutex)(&data->lock); >>>> clk_enable(data->clk); >>>> >>>> /* TODO: take action based on particular interrupt */ >>>> data->tmu_clear_irqs(data); >>>> >>>> clk_disable(data->clk); >>>> - mutex_unlock(&data->lock); >>>> >>>> return IRQ_HANDLED; >>>> } >>>> @@ -987,7 +981,7 @@ static int exynos_set_trips(struct thermal_zone_device *tz, int low, int high) >>>> { >>>> struct exynos_tmu_data *data = thermal_zone_device_priv(tz); >>>> >>>> - mutex_lock(&data->lock); >>>> + guard(mutex)(&data->lock); >>>> clk_enable(data->clk); >>>> >>>> if (low > INT_MIN) >>>> @@ -1000,7 +994,6 @@ static int exynos_set_trips(struct thermal_zone_device *tz, int low, int high) >>>> data->tmu_disable_high(data); >>>> >>>> clk_disable(data->clk); >>>> - mutex_unlock(&data->lock); >>>> >>>> return 0; >>>> } >> >> Thanks for your review comments. >>> >>> IMO you should be able to even use something like we have >>> core framework: >>> >>> guard(thermal_zone)(tz); >>> >>> Your mutex name is simply 'lock' in the struct exynos_tmu_data >>> so you should be able to leverage this by: >>> >>> guard(exynos_tmu_data)(data); >>> > > If I introduce the guard it creates a compilation error > > amoon@anand-m920q:~/mainline/linux-exynos-6.y-devel$ vi > drivers/thermal/samsung/exynos_tmu.c +306 > amoon@anand-m920q:~/mainline/linux-exynos-6.y-devel$ make -j$(nproc) > ARCH=arm CROSS_COMPILE=arm-none-eabi- LOCALVERSION=-u3ml dtbs zImage > modules > CALL scripts/checksyscalls.sh > CHK kernel/kheaders_data.tar.xz > CC drivers/thermal/samsung/exynos_tmu.o > CC [M] drivers/md/raid10.o > In file included from ./include/linux/irqflags.h:17, > from ./arch/arm/include/asm/bitops.h:28, > from ./include/linux/bitops.h:68, > from ./include/linux/kernel.h:23, > from ./include/linux/clk.h:13, > from drivers/thermal/samsung/exynos_tmu.c:14: > drivers/thermal/samsung/exynos_tmu.c: In function 'exynos_tmu_update_bit': > ./include/linux/cleanup.h:258:9: error: unknown type name > 'class_exynos_tmu_data_t' > 258 | class_##_name##_t var > __cleanup(class_##_name##_destructor) = \ > | ^~~~~~ > ./include/linux/cleanup.h:309:9: note: in expansion of macro 'CLASS' > 309 | CLASS(_name, __UNIQUE_ID(guard)) > | ^~~~~ > drivers/thermal/samsung/exynos_tmu.c:338:9: note: in expansion of macro 'guard' > 338 | guard(exynos_tmu_data)(data); > | ^~~~~ > drivers/thermal/samsung/exynos_tmu.c:338:9: error: cleanup argument > not a function [snip] Right, you're missing the definition at the begging, like: DEFINE_GUARD(exynos_tmu_data, struct exynos_tmu_data *, mutex_lock(&_T->lock), mutex_unlock(&_T->lock)) below the struct exynos_tmu_data definition. Also, make sure you include the cleanup.h (it might not complain, but it would be explicit and more clear)