[RFC PATCH 0/2] ARM: update cpuinfo to print CPU model name

Ruslan Bilovol ruslan.bilovol at gmail.com
Wed Jan 30 08:20:31 EST 2013


On Wed, Jan 30, 2013 at 1:38 AM, Nishanth Menon <nm at ti.com> wrote:
> On 01:08-20130130, Ruslan Bilovol wrote:
>> Hi,
>>
>> On Tue, Jan 29, 2013 at 6:02 PM, Nishanth Menon <nm at ti.com> wrote:
>> >
>> > On 17:54-20130129, Ruslan Bilovol wrote:
>> > > Hi,
>> > >
>> > > The following patches update cpuinfo to print CPU
>> > > model name for ARM. First patch exactly makes needed
>> > > changes for ARM architecture.
>> > > Second patch adds this ability to OMAP4 SoCs.
>> > >
>> > > This adds a common approach to show SoC name.
>> > >
>> > > Looks like there were few attempts to do similar
>> > > changes to cpuinfo without any luck.
>> > >
>> > > So - comments are welcome
>> > >
>> > > Ruslan Bilovol (2):
>> > >   ARM: kernel: update cpuinfo to print CPU model name
>> > >   ARM: OMAP4: setup CPU model name during ID initialisation
>> >
>> > We had an discussion on similar lines but a generic suggestion:
>> > https://patchwork.kernel.org/patch/98720/
>> > SoCinfo framework which was supposed to introduce this
>> >
>> > Would'nt that be a better approach to take than an OMAP only solution?
>>
>> My goal is only to say what is the SoC model name in the /proc/cpuinfo
>> (And it is not an OMAP-only solution - it is common. Support for OMAP
>> is added in second patch)
>> This is the only type of information that we can apply for any SoC.
>> My point is - any SoC-specific information should go through some other
>> way - like SoCinfo framework mentioned by you.
>> And additional point - in cpuinfo we already have CPU name and Machine name.
>> The SoC name (that is something between these two things) looks also relevant
> Looking at the sample output in patch #1/2
> OMAP4470 ES1.0 HS
>
> OMAP4470 is SoC name
> ES1.0 is SoC revision
> HS is SoC type

Will fix it in next patchseries. Let's leave only only SoC name

>
> We even have SoC features (e.g. at boot NEON etc..)
>
> Is the intent to put all this inside /proc/cpuinfo?? I bet every SoC has
> it's own interesting data it'd like to have (like some of the info
> populated by DT even). I am hardpressed to think this fits inside
> /proc/cpuinfo. I might even suspect that the list of interesting
> information might even vary per SoC.

No, I don't think we need all these information in cpuinfo - just because
it will be different for different SoC - so the file structure will be
very different..
Let's have only SoC name in cpuinfo.

>
> having machine name is something ARM specific? dumping it on my linux
> machines (x86[1] and sparc[2]) dont seem to show that.

Yes - it's ARM specific.

>
> but in the interest of not breaking existing interfaces, new interfaces
> should potentially belong elsewhere.. my 2 cents.
>
> [1] http://pastebin.com/CF8HPDAC (Xubuntu 12.04 3.2.0-36)
> [2] http://pastebin.com/qNwWHwiu (Debian 3.2.35-2)

Just look at changes in cpuinfo for ARM between kernels:
3.4 kernel: http://pastebin.com/TfmE7b2b
3.8-rc3: http://pastebin.com/zvvTGeNt

The file structure has huge changes

> --
> Regards,
> Nishanth Menon



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