[PATCH 02/10] ARM: V7M: Make read_cpuid() generally available on V7M.

Vladimir Murzin vladimir.murzin at arm.com
Mon Jun 13 09:21:18 PDT 2016


On 13/06/16 16:15, Russell King - ARM Linux wrote:
> On Mon, Jun 13, 2016 at 04:03:01PM +0100, Vladimir Murzin wrote:
>> This requires a custom specialisation for each of the CPUID_* registers, and
>> as more than just CPUID_ID may be implemented in the future this doesn't
>> make much sense.
> 
> You shouldn't need most of this patch.  The CPUID registers are defined
> in such a way that unimplemented registers do not fault, but return the
> MIDR value.  If you're just implementing MIDR, then you should just
> return the MIDR value and be done with it.
> 
> (Any location reading the other CPUID registers without checking whether
> it's a MIDR alias is probably buggy.)
> 

I'll think on it more. Thanks for feedback!

Cheers
Vladimir



More information about the linux-arm-kernel mailing list