From mboxrd@z Thu Jan  1 00:00:00 1970
From: vladimir.murzin@arm.com (Vladimir Murzin)
Date: Mon, 13 Jun 2016 17:21:18 +0100
Subject: [PATCH 02/10] ARM: V7M: Make read_cpuid() generally available on
 V7M.
In-Reply-To: <20160613151517.GV1041@n2100.armlinux.org.uk>
References: <1465830189-20128-1-git-send-email-vladimir.murzin@arm.com>
 <1465830189-20128-3-git-send-email-vladimir.murzin@arm.com>
 <20160613151517.GV1041@n2100.armlinux.org.uk>
Message-ID: <575EDD7E.20202@arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

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