From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751939AbZH0LwD (ORCPT ); Thu, 27 Aug 2009 07:52:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751462AbZH0LwC (ORCPT ); Thu, 27 Aug 2009 07:52:02 -0400 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:56429 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751044AbZH0LwB (ORCPT ); Thu, 27 Aug 2009 07:52:01 -0400 Date: Thu, 27 Aug 2009 17:21:47 +0530 From: Arun R Bharadwaj To: Joel Schopp , Benjamin Herrenschmidt , Paul Mackerras , Peter Zijlstra , Ingo Molnar , Vaidyanathan Srinivasan , Dipankar Sarma , Balbir Singh , Gautham R Shenoy , "Pallipadi, Venkatesh" , Arun Bharadwaj Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH 1/4]: CPUIDLE/POWER: Enable cpuidle for pSeries. Message-ID: <20090827115147.GB24986@linux.vnet.ibm.com> Reply-To: arun@linux.vnet.ibm.com References: <20090827114908.GA24986@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090827114908.GA24986@linux.vnet.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Arun R Bharadwaj [2009-08-27 17:19:08]: This patch enables the cpuidle option in Kconfig for pSeries. Currently cpuidle infrastructure is enabled only for x86 and ARM. This code is almost completely borrowed from x86 to enable cpuidle for pSeries. Signed-off-by: Arun R Bharadwaj --- arch/powerpc/Kconfig | 17 +++++++++++++++++ arch/powerpc/include/asm/system.h | 2 ++ arch/powerpc/kernel/idle.c | 19 +++++++++++++++++++ 3 files changed, 38 insertions(+) Index: linux.trees.git/arch/powerpc/Kconfig =================================================================== --- linux.trees.git.orig/arch/powerpc/Kconfig +++ linux.trees.git/arch/powerpc/Kconfig @@ -88,6 +88,9 @@ config ARCH_HAS_ILOG2_U64 bool default y if 64BIT +config ARCH_HAS_CPU_IDLE_WAIT + def_bool y + config GENERIC_HWEIGHT bool default y @@ -243,6 +246,20 @@ source "kernel/Kconfig.freezer" source "arch/powerpc/sysdev/Kconfig" source "arch/powerpc/platforms/Kconfig" +menu "Power management options" + +source "drivers/cpuidle/Kconfig" + +config PSERIES_PROCESSOR_IDLE + bool "Idle Power Management Support for pSeries" + depends on PPC_PSERIES && CPU_IDLE + default y + help + Idle Power Management Support for pSeries. This hooks onto cpuidle + infrastructure to help in idle cpu power management. + +endmenu + menu "Kernel options" config HIGHMEM Index: linux.trees.git/arch/powerpc/include/asm/system.h =================================================================== --- linux.trees.git.orig/arch/powerpc/include/asm/system.h +++ linux.trees.git/arch/powerpc/include/asm/system.h @@ -546,5 +546,7 @@ extern void account_system_vtime(struct extern struct dentry *powerpc_debugfs_root; +void cpu_idle_wait(void); + #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_SYSTEM_H */ Index: linux.trees.git/arch/powerpc/kernel/idle.c =================================================================== --- linux.trees.git.orig/arch/powerpc/kernel/idle.c +++ linux.trees.git/arch/powerpc/kernel/idle.c @@ -102,6 +102,25 @@ void cpu_idle(void) } } +static void do_nothing(void *unused) +{ +} + +/* + * cpu_idle_wait - Used to ensure that all the CPUs discard old value of + * ppc_md.power_save and update to new value. + * Required while changing ppc_md.power_save handler on SMP systems. + * Caller must have changed ppc_md.power_save to the new value before the call. + */ +void cpu_idle_wait(void) +{ + /* Ensure that new value of ppc_md.power_save is set */ + smp_mb(); + /* kick all the CPUs so that they exit out of ppc_md.power_save */ + smp_call_function(do_nothing, NULL, 1); +} +EXPORT_SYMBOL_GPL(cpu_idle_wait); + int powersave_nap; #ifdef CONFIG_SYSCTL