Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756214Ab1FGQaN (ORCPT ); Tue, 7 Jun 2011 12:30:13 -0400 Received: from e23smtp06.au.ibm.com ([202.81.31.148]:58015 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754213Ab1FGQaJ (ORCPT ); Tue, 7 Jun 2011 12:30:09 -0400 From: Trinabh Gupta Subject: [RFC PATCH V1 4/7] cpuidle: (powerpc) Add cpu_idle_wait() to allow switching idle routines To: linux-pm@lists.linux-foundation.org, linuxppc-dev@ozlabs.org Cc: linux-kernel@vger.kernel.org Date: Tue, 07 Jun 2011 22:00:04 +0530 Message-ID: <20110607162959.6848.26918.stgit@tringupt.in.ibm.com> In-Reply-To: <20110607162847.6848.44707.stgit@tringupt.in.ibm.com> References: <20110607162847.6848.44707.stgit@tringupt.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2196 Lines: 75 This patch provides cpu_idle_wait() routine required by the cpuidle subsystem. Almost all the code is borrowed from x86. Signed-off-by: Trinabh Gupta Signed-off-by: Arun R Bharadwaj --- arch/powerpc/Kconfig | 4 ++++ arch/powerpc/include/asm/system.h | 1 + arch/powerpc/kernel/idle.c | 18 ++++++++++++++++++ 3 files changed, 23 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 2729c66..518beda 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -87,6 +87,10 @@ config ARCH_HAS_ILOG2_U64 bool default y if 64BIT +config ARCH_HAS_CPU_IDLE_WAIT + bool + default y + config GENERIC_HWEIGHT bool default y diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/system.h index 2dc595d..811cdf1 100644 --- a/arch/powerpc/include/asm/system.h +++ b/arch/powerpc/include/asm/system.h @@ -222,6 +222,7 @@ extern unsigned long klimit; extern void *zalloc_maybe_bootmem(size_t size, gfp_t mask); extern int powersave_nap; /* set if nap mode can be used in idle loop */ +void cpu_idle_wait(void); /* * Atomic exchange diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c index 39a2baa..932392b 100644 --- a/arch/powerpc/kernel/idle.c +++ b/arch/powerpc/kernel/idle.c @@ -102,6 +102,24 @@ void cpu_idle(void) } } +static void do_nothing(void *unused) +{ +} + +/* + * cpu_idle_wait - Used to ensure that all the CPUs come out of the old + * idle loop and start using the new idle loop. + * Required while changing idle handler on SMP systems. + * Caller must have changed idle handler to the new value before the call. + */ +void cpu_idle_wait(void) +{ + smp_mb(); + /* kick all the CPUs so that they exit out of old idle routine */ + smp_call_function(do_nothing, NULL, 1); +} +EXPORT_SYMBOL_GPL(cpu_idle_wait); + int powersave_nap; #ifdef CONFIG_SYSCTL -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/