Re: [PATCH v4] MIPS: Expose prid and globalnumber to sysfs

From: Greg KH
Date: Tue Aug 16 2022 - 08:42:29 EST


On Tue, Aug 16, 2022 at 01:38:27PM +0100, Jiaxun Yang wrote:
>
>
> 在2022年8月16日八月 上午10:21,Greg KH写道:
> > On Tue, Aug 16, 2022 at 09:12:58AM +0000, Jiaxun Yang wrote:
> >> Some application would like to know precise model and rev of processor
> >> to do errata workaround or optimization.
> >>
> >> Expose them in sysfs as:
> >> /sys/devices/system/cpu/cpuX/regs/identification/prid
> >> /sys/devices/system/cpu/cpuX/regs/identification/globalnumber
> >>
> >> Reusing AArch64 CPU registers directory.
> >>
> >> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
> >> ---
> >> v2: Drop static qualifier for kobj (gregkh)
> >> v3: Use kzalloc to allocate struct cpuregs.
> >> note: When Greg mentioned about static I was thinking about
> >> static qualifier of percpu variable. After reading documents
> >> again it turns out kobjs should be allocated at runtime. Arm64's
> >> cpuinfo kobj is also on a percpu variable... I guess that was a
> >> intentional use?
> >> v4: Properly handle err of kobj creation. (gregkh)
> >
> > Nothing was fixed :(
>
> [Resending due to previous mail contains HTML. I just got a Macbook
> and was trying to use it's built-in mail client. Turns out that it's
> sending HTML even with "Plain Text" selected...
> Now turning back to mutt. Apologise for inconvinence.]
>
> Hi Greg,
>
> Sorry for misinterpret your comments again :(
>
> Hmm I just use kobject_put to replace kobject_del.
> I thought that was what you were trying to say?

Yes, I think that is correct (I have no context here), but you can't
then call kfree() as the memory is now gone from the last put, right?

Try it and see :)

thanks,

greg k-h