From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752265AbbFYPAP (ORCPT ); Thu, 25 Jun 2015 11:00:15 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:29044 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752031AbbFYPAL (ORCPT ); Thu, 25 Jun 2015 11:00:11 -0400 Subject: Re: [PATCH] keystone: psci: adds cpu_die implementation To: Mark Rutland , Vitaly Andrianov References: <1435240970-30869-1-git-send-email-vitalya@ti.com> <20150625144511.GA6844@leverpostej> Cc: "ssantosh@kernel.org" , "linux@arm.linux.org.uk" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , lorenzo.pieralisi@arm.com From: santosh shilimkar Organization: Oracle Corporation Message-ID: <558C174F.80108@oracle.com> Date: Thu, 25 Jun 2015 07:59:27 -0700 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.0.1 MIME-Version: 1.0 In-Reply-To: <20150625144511.GA6844@leverpostej> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. >> >> Signed-off-by: Vitaly Andrianov >> --- >> arch/arm/mach-keystone/platsmp.c | 32 ++++++++++++++++++++++++++++++++ >> 1 file changed, 32 insertions(+) >> >> diff --git a/arch/arm/mach-keystone/platsmp.c b/arch/arm/mach-keystone/platsmp.c >> index 5f46a7c..2c40cc0 100644 >> --- a/arch/arm/mach-keystone/platsmp.c >> +++ b/arch/arm/mach-keystone/platsmp.c >> @@ -20,6 +20,7 @@ >> #include >> #include >> #include >> +#include >> >> #include "keystone.h" >> >> @@ -51,7 +52,38 @@ static inline void __cpuinit keystone_smp_secondary_initmem(unsigned int cpu) >> {} >> #endif >> >> + >> +#ifdef CONFIG_HOTPLUG_CPU >> +static void keystone_cpu_die(unsigned int cpu) >> +{ >> +#ifdef CONFIG_ARM_PSCI >> + struct psci_power_state pwr_state = {0, 0, 0}; >> + >> + pr_info("keystone_cpu_die(%d) from %d using PSCI\n", cpu, >> + smp_processor_id()); >> + >> + if (psci_ops.cpu_off) >> + psci_ops.cpu_off(pwr_state); >> +#else >> + /* >> + * We may want to add here a direct smc call to monitor >> + * if the kernel doesn't support PSCI API >> + */ >> +#endif > > You should determine this from your DT. Your FW/bootloader can patch in > the relevant nodes and properties when support is present, so the > presence of such nodes should guarantee that PSCI is available. > That will be a nice trick. FW already does some tweaks of dts for LPAE/non_LPAE tweaks. Regards, Santosh