Re: [PATCH v2 18/21] powerpc: use libfdt accessors for header data

From: Michal Simek <monstr@monstr.eu>
To: Rob Herring <robherring2@gmail.com>
Cc: Grant Likely <grant.likely@linaro.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>
Subject: Re: [PATCH v2 18/21] powerpc: use libfdt accessors for header data
Date: Wed, 23 Apr 2014 16:21:26 +0200	[thread overview]
Message-ID: <5357CC66.5080802@monstr.eu> (raw)
In-Reply-To: <CAL_JsqKg8oAd+JmmhERa3Xb1dD9CPz1_cVM3mb=ypWhxkZJHtQ@mail.gmail.com>

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On 04/23/2014 04:05 PM, Rob Herring wrote:
> On Wed, Apr 23, 2014 at 8:48 AM, Michal Simek <monstr@monstr.eu> wrote:
>> On 04/23/2014 03:18 AM, Rob Herring wrote:
>>> From: Rob Herring <robh@kernel.org>
>>>
>>> With libfdt support, we can take advantage of helper accessors in libfdt
>>> for accessing the FDT header data. This makes the code more readable and
>>> makes the FDT blob structure more opaque to the kernel. This also
>>> prepares for removing struct boot_param_header completely.
> 
> [...]
> 
>>> @@ -117,14 +118,14 @@ static void __init move_device_tree(void)
>>>       DBG("-> move_device_tree\n");
>>>
>>>       start = __pa(initial_boot_params);
>>> -     size = be32_to_cpu(initial_boot_params->totalsize);
>>> +     size = fdt_totalsize(initial_boot_params);
>>
>> In 19/21 you use your newly introduced of_get_flat_dt_size()
>> that's why I expect you will use it here too.
>> size = of_get_flat_dt_size();
>>
>> The same is for 14/21 where you can use this new function too.
>> It means moving 14/21 to the end and using this new function
>> makes more sense.
> 
> Really, I would prefer to just use libfdt accessors directly rather
> than have wrappers, but including libfdt.h is not the cleanest
> solution. Since x86 just needed this one function, I added a wrapper.
> Since PPC needs other header fields I prefer to use the libfdt
> accessors directly for all fields. The same goes for drivers/of/fdt.c.

Ok. I see your point but maybe will be good to reflect that it is
there just for x86 case and none else should use it.

Thanks,
Michal

-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform

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