From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [RFC PATCH v2 3/4] powerpc: refactor of_get_cpu_node to support other architectures Date: Mon, 19 Aug 2013 08:02:52 -0500 Message-ID: <5212177C.8000709@gmail.com> References: <1376586580-5409-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1376674791-28244-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1376674791-28244-2-git-send-email-Sudeep.KarkadaNagesha@arm.com> <2032060.4bgTKOdEX2@flatron> <1376777376.25016.11.camel@pasglop> <20130819101922.GI3719@e106331-lin.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130819101922.GI3719@e106331-lin.cambridge.arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Mark Rutland Cc: Benjamin Herrenschmidt , Jonas Bonn , "devicetree@vger.kernel.org" , Michal Simek , "linux-pm@vger.kernel.org" , Sudeep KarkadaNagesha , Tomasz Figa , "rob.herring@calxeda.com" , "linux-kernel@vger.kernel.org" , "Rafael J. Wysocki" , "grant.likely@linaro.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-arm-kernel@lists.infradead.org" , Lorenzo Pieralisi List-Id: linux-pm@vger.kernel.org On 08/19/2013 05:19 AM, Mark Rutland wrote: > On Sat, Aug 17, 2013 at 11:09:36PM +0100, Benjamin Herrenschmidt wrote: >> On Sat, 2013-08-17 at 12:50 +0200, Tomasz Figa wrote: >>> I wonder how would this handle uniprocessor ARM (pre-v7) cores, for >>> which >>> the updated bindings[1] define #address-cells = <0> and so no reg >>> property. >>> >>> [1] - http://thread.gmane.org/gmane.linux.ports.arm.kernel/260795 >> >> Why did you do that in the binding ? That sounds like looking to create >> problems ... >> >> Traditionally, UP setups just used "0" as the "reg" property on other >> architectures, why do differently ? > > The decision was taken because we defined our reg property to refer to > the MPIDR register's Aff{2,1,0} bitfields, and on UP cores before v7 > there's no MPIDR register at all. Given there can only be a single CPU > in that case, describing a register that wasn't present didn't seem > necessary or helpful. What exactly reg represents is up to the binding definition, but it still should be present IMO. I don't see any issue with it being different for pre-v7. Rob > > Thanks, > Mark. > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >