From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Thu, 25 Jun 2015 17:13:08 +0100 Subject: [PATCH] keystone: psci: adds cpu_die implementation In-Reply-To: <558C25E0.3010102@ti.com> References: <1435240970-30869-1-git-send-email-vitalya@ti.com> <20150625144511.GA6844@leverpostej> <558C174F.80108@oracle.com> <558C25E0.3010102@ti.com> Message-ID: <20150625161308.GF6844@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jun 25, 2015 at 05:01:36PM +0100, Vitaly Andrianov wrote: > > > On 06/25/2015 10:59 AM, santosh shilimkar wrote: > > On 6/25/2015 7:45 AM, Mark Rutland wrote: > >> Hi, > >> > >> On Thu, Jun 25, 2015 at 03:02:50PM +0100, Vitaly Andrianov wrote: > >>> This commit add cpu_die implementation using psci api > >> > >> I don't understand. If you have a PSCI implementation, it should be > >> sufficient to have a PSCI node (and enable-method) in your DT, and the > >> generic code will be used. Nothing should be required in your board > >> code. > >> > >> You should also use CPU_ON to bring secondaries online rather than > >> mixing up PSCI and platform-specific mechanisms. > >> > > Good point about CPU_ON. We need that as well. > > > Does it mean that keystone_defconfig must always have CONFIG_HOTPLUG_CPU > and CONFIG_ARM_PSCI enabled? No. You need CONFIG_ARM_PSCI for PSCI CPU_ON. Without CONFIG_HOTPLUG_CPU, you'll get PSCI CPU_ON but not PSCI CPU_OFF. > What is if someone doesn't want to have HOTPLUG_CPU? Then you don't get PSCI CPU_OFF, but can still have PSCI CPU_ON. Only the portions of the PSCI code required for turning CPUs off are dependent on HOTPLUG_CPU. > How he can boot secondary CPU w/o platform-specific mechanizm? By using PSCI CPU_ON. Thanks, Mark From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751874AbbFYQNj (ORCPT ); Thu, 25 Jun 2015 12:13:39 -0400 Received: from foss.arm.com ([217.140.101.70]:57642 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751790AbbFYQN0 (ORCPT ); Thu, 25 Jun 2015 12:13:26 -0400 Date: Thu, 25 Jun 2015 17:13:08 +0100 From: Mark Rutland To: Vitaly Andrianov Cc: santosh shilimkar , "ssantosh@kernel.org" , "linux@arm.linux.org.uk" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Lorenzo Pieralisi Subject: Re: [PATCH] keystone: psci: adds cpu_die implementation Message-ID: <20150625161308.GF6844@leverpostej> References: <1435240970-30869-1-git-send-email-vitalya@ti.com> <20150625144511.GA6844@leverpostej> <558C174F.80108@oracle.com> <558C25E0.3010102@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <558C25E0.3010102@ti.com> 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 Thu, Jun 25, 2015 at 05:01:36PM +0100, Vitaly Andrianov wrote: > > > On 06/25/2015 10:59 AM, santosh shilimkar wrote: > > On 6/25/2015 7:45 AM, Mark Rutland wrote: > >> Hi, > >> > >> On Thu, Jun 25, 2015 at 03:02:50PM +0100, Vitaly Andrianov wrote: > >>> This commit add cpu_die implementation using psci api > >> > >> I don't understand. If you have a PSCI implementation, it should be > >> sufficient to have a PSCI node (and enable-method) in your DT, and the > >> generic code will be used. Nothing should be required in your board > >> code. > >> > >> You should also use CPU_ON to bring secondaries online rather than > >> mixing up PSCI and platform-specific mechanisms. > >> > > Good point about CPU_ON. We need that as well. > > > Does it mean that keystone_defconfig must always have CONFIG_HOTPLUG_CPU > and CONFIG_ARM_PSCI enabled? No. You need CONFIG_ARM_PSCI for PSCI CPU_ON. Without CONFIG_HOTPLUG_CPU, you'll get PSCI CPU_ON but not PSCI CPU_OFF. > What is if someone doesn't want to have HOTPLUG_CPU? Then you don't get PSCI CPU_OFF, but can still have PSCI CPU_ON. Only the portions of the PSCI code required for turning CPUs off are dependent on HOTPLUG_CPU. > How he can boot secondary CPU w/o platform-specific mechanizm? By using PSCI CPU_ON. Thanks, Mark