From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH] xen: arm: ignore CPUs which are not marked available in the DT Date: Thu, 24 Jul 2014 11:36:01 +0100 Message-ID: <53D0E191.9000001@linaro.org> References: <1f69ed8ee6a21c2a0c4d548ae83260b14c54ab36.1406133950.git.ian.campbell@citrix.com> <53CFEDB3.4000702@linaro.org> <1406140610.29480.5.camel@dagon.hellion.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1406140610.29480.5.camel@dagon.hellion.org.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: stefano.stabellini@eu.citrix.com, tim@xen.org, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org Hi Ian, On 23/07/14 19:36, Ian Campbell wrote: > On Wed, 2014-07-23 at 18:15 +0100, Julien Grall wrote: >> On 07/23/2014 05:45 PM, Ian Campbell wrote: >>> Signed-off-by: Ian Campbell >>> --- >>> xen/arch/arm/smpboot.c | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c >>> index cf149da..4b0a738 100644 >>> --- a/xen/arch/arm/smpboot.c >>> +++ b/xen/arch/arm/smpboot.c >>> @@ -134,6 +134,9 @@ void __init smp_init_cpus(void) >>> if ( !dt_device_type_is_equal(cpu, "cpu") ) >>> continue; >>> >>> + if ( !dt_device_is_available(cpu) ) >>> + continue; >>> + >> >> I can't find a such things on the Linux device tree bindings. > > status is a generic property which is common to all nodes, it comes from > ePAPR. > >> Do you >> have a use case where CPU are marked disabled? > > I use it locally when booting with models -- it allows me to turn off > cpus in the base .dts file using a wrapper instead of having to edit the > original. I read the ePAPR and the property status on CPU node. AFAIU, the = property doesn't have this meaning for a such node. This property means the CPU is in quiescent state and property to bring = up the CPU is provides in the device tree node. Section 5.5.2.2: Before starting a client program on the boot cpu, the boot program shall = set certain properties in the device tree passed to the client as follows: =95 Each secondary CPU=92s cpu node shall have a status property with a = value of =93disabled=94. Regards, -- = Julien Grall