From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753272AbbF2Rwu (ORCPT ); Mon, 29 Jun 2015 13:52:50 -0400 Received: from foss.arm.com ([217.140.101.70]:39171 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753480AbbF2Rwm (ORCPT ); Mon, 29 Jun 2015 13:52:42 -0400 Date: Mon, 29 Jun 2015 18:52:23 +0100 From: Mark Rutland To: Vitaly Andrianov Cc: "linux@arm.linux.org.uk" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "ssantosh@kernel.org" , Lorenzo Pieralisi , "grygorii.strashko@ti.com" Subject: Re: [PATCH] keystone: adds cpu_die implementation Message-ID: <20150629175223.GC19863@leverpostej> References: <1435600352-32733-1-git-send-email-vitalya@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1435600352-32733-1-git-send-email-vitalya@ti.com> Thread-Topic: [PATCH] keystone: adds cpu_die implementation Accept-Language: en-GB, en-US Content-Language: en-US User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 29, 2015 at 06:52:32PM +0100, Vitaly Andrianov wrote: > This commit add cpu_die implementation > > Signed-off-by: Vitaly Andrianov > --- > > The discussion of the "keystone: psci: adds cpu_die implementation" commit > shows that if PCSI is enabled platform code doesn't need that implementation > at all. Having PSCI commands in DTB should be sufficient. Unfortunately > Keystone with LPAE enable requires some additional development. I don't follow. What do you need to implement for LPAE? Why not implement that rather than adding more platform code that you'll likely want to remove later anyway? Thanks, Mark. > To support HOTPLUG_CPU w/o PSCI we need platform implementation of > the cpu_die(), which is added by this patch. > > arch/arm/mach-keystone/keystone.h | 1 + > arch/arm/mach-keystone/platsmp.c | 24 ++++++++++++++++++++++++ > 2 files changed, 25 insertions(+) > > diff --git a/arch/arm/mach-keystone/keystone.h b/arch/arm/mach-keystone/keystone.h > index cd04a1c..93549cf 100644 > --- a/arch/arm/mach-keystone/keystone.h > +++ b/arch/arm/mach-keystone/keystone.h > @@ -12,6 +12,7 @@ > #define __KEYSTONE_H__ > > #define KEYSTONE_MON_CPU_UP_IDX 0x00 > +#define KEYSTONE_MON_CPU_DIE_IDX 0x84000002 > > #ifndef __ASSEMBLER__ > > diff --git a/arch/arm/mach-keystone/platsmp.c b/arch/arm/mach-keystone/platsmp.c > index 5f46a7c..4e5bdde 100644 > --- a/arch/arm/mach-keystone/platsmp.c > +++ b/arch/arm/mach-keystone/platsmp.c > @@ -51,7 +51,31 @@ static inline void __cpuinit keystone_smp_secondary_initmem(unsigned int cpu) > {} > #endif > > + > +#ifdef CONFIG_HOTPLUG_CPU > +static void keystone_cpu_die(unsigned int cpu) > +{ > + int error; > + > + pr_debug("keystone-smp: cpu_die %d\n", cpu); > + > + error = keystone_cpu_smc(KEYSTONE_MON_CPU_DIE_IDX, cpu, 0); > + if (error) > + pr_err("CPU %d die failed with %d\n", cpu, error); > + > + /* > + * we shouldn't come here. But in case something went > + * wrong the code below prevents kernel from crush > + */ > + while (1) > + cpu_do_idle(); > +} > +#endif > + > struct smp_operations keystone_smp_ops __initdata = { > .smp_boot_secondary = keystone_smp_boot_secondary, > .smp_secondary_init = keystone_smp_secondary_initmem, > +#ifdef CONFIG_HOTPLUG_CPU > + .cpu_die = keystone_cpu_die, > +#endif > }; > -- > 1.9.1 >