From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1751824AbdLYBoK (ORCPT <rfc822;w@1wt.eu>);
        Sun, 24 Dec 2017 20:44:10 -0500
Received: from szxga04-in.huawei.com ([45.249.212.190]:2726 "EHLO huawei.com"
        rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP
        id S1751112AbdLYBoG (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Sun, 24 Dec 2017 20:44:06 -0500
Subject: Re: [PATCH v3 27/27] devres: kill devm_ioremap_nocache
To: Greg KH <gregkh@linuxfoundation.org>
References: <1514026979-33838-1-git-send-email-xieyisheng1@huawei.com>
 <20171223134532.GA10103@kroah.com>
CC: <linux-kernel@vger.kernel.org>, <linux-mips@linux-mips.org>,
        <ulf.hansson@linaro.org>, <jakub.kicinski@netronome.com>,
        <airlied@linux.ie>, <linux-wireless@vger.kernel.org>,
        <linus.walleij@linaro.org>, <alsa-devel@alsa-project.org>,
        <dri-devel@lists.freedesktop.org>,
        <platform-driver-x86@vger.kernel.org>, <linux-ide@vger.kernel.org>,
        <linux-mtd@lists.infradead.org>, <daniel.vetter@intel.com>,
        <dan.j.williams@intel.com>, <jason@lakedaemon.net>,
        <linux-rtc@vger.kernel.org>, <boris.brezillon@free-electrons.com>,
        <mchehab@kernel.org>, <dmaengine@vger.kernel.org>,
        <vinod.koul@intel.com>, <richard@nod.at>, <marek.vasut@gmail.com>,
        <industrypack-devel@lists.sourceforge.net>,
        <linux-pci@vger.kernel.org>, <dvhart@infradead.org>,
        <linux@roeck-us.net>, <linux-media@vger.kernel.org>,
        <seanpaul@chromium.org>, <devel@driverdev.osuosl.org>,
        <linux-watchdog@vger.kernel.org>, <arnd@arndb.de>,
        <b.zolnierkie@samsung.com>, <marc.zyngier@arm.com>, <jslaby@suse.com>,
        <jani.nikula@linux.intel.com>, <linux-can@vger.kernel.org>,
        <linux-gpio@vger.kernel.org>, <broonie@kernel.org>,
        <mkl@pengutronix.de>, <linux-fbdev@vger.kernel.org>,
        <nios2-dev@lists.rocketboards.org>, <bhelgaas@google.com>,
        <tglx@linutronix.de>, <andriy.shevchenko@linux.intel.com>,
        <kvalo@codeaurora.org>, <a.zummo@towertech.it>,
        <netdev@vger.kernel.org>, <linux-mmc@vger.kernel.org>,
        <lgirdwood@gmail.com>, <ralf@linux-mips.org>,
        <linux-spi@vger.kernel.org>, <ysxie@foxmail.com>, <wg@grandegger.com>,
        <cyrille.pitchen@wedev4u.fr>, <tj@kernel.org>,
        <alexandre.belloni@free-electrons.com>, <davem@davemloft.net>,
        <andy@infradead.org>
From: Yisheng Xie <xieyisheng1@huawei.com>
Message-ID: <4d0991ec-9cd4-0c33-5560-ae9c2c762765@huawei.com>
Date: Mon, 25 Dec 2017 09:43:40 +0800
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101
 Thunderbird/45.1.0
MIME-Version: 1.0
In-Reply-To: <20171223134532.GA10103@kroah.com>
Content-Type: text/plain; charset="windows-1252"
Content-Transfer-Encoding: 7bit
X-Originating-IP: [10.177.29.40]
X-CFilter-Loop: Reflected
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org



On 2017/12/23 21:45, Greg KH wrote:
> On Sat, Dec 23, 2017 at 07:02:59PM +0800, Yisheng Xie wrote:
>> --- a/lib/devres.c
>> +++ b/lib/devres.c
>> @@ -44,35 +44,6 @@ void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
>>  EXPORT_SYMBOL(devm_ioremap);
>>  
>>  /**
>> - * devm_ioremap_nocache - Managed ioremap_nocache()
>> - * @dev: Generic device to remap IO address for
>> - * @offset: Resource address to map
>> - * @size: Size of map
>> - *
>> - * Managed ioremap_nocache().  Map is automatically unmapped on driver
>> - * detach.
>> - */
>> -void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
>> -				   resource_size_t size)
>> -{
>> -	void __iomem **ptr, *addr;
>> -
>> -	ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
>> -	if (!ptr)
>> -		return NULL;
>> -
>> -	addr = ioremap_nocache(offset, size);
> 
> Wait, devm_ioremap() calls ioremap(), not ioremap_nocache(), are you
> _SURE_ that these are all identical?  For all arches?  If so, then
> ioremap_nocache() can also be removed, right?

Yeah, As Christophe pointed out, that 4 archs do not have the same function.
But I do not why they do not want do the same thing. Driver may no know about
this? right?

> 
> In my quick glance, I don't think you can do this series at all :(

Yes, maybe should take Christophe suggestion and use a bool or enum to distinguish them?

Thanks
Yisheng
> 
> greg k-h
> 
> .
>