Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753518AbaA0GYU (ORCPT ); Mon, 27 Jan 2014 01:24:20 -0500 Received: from relais.videotron.ca ([24.201.245.36]:51663 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753451AbaA0GYQ (ORCPT ); Mon, 27 Jan 2014 01:24:16 -0500 X-Greylist: delayed 901 seconds by postgrey-1.27 at vger.kernel.org; Mon, 27 Jan 2014 01:24:12 EST Content-transfer-encoding: 7BIT From: Nicolas Pitre To: Russell King , Catalin Marinas , Benjamin Herrenschmidt , Paul Mundt , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , "Rafael J. Wysocki" , Daniel Lezcano Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, linux-pm@vger.kernel.org, linaro-kernel@lists.linaro.org Subject: [PATCH 6/9] PPC: remove redundant cpuidle_idle_call() Date: Mon, 27 Jan 2014 01:08:21 -0500 Message-id: <1390802904-28399-7-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 1.8.4.108.g55ea5f6 In-reply-to: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org> References: <1390802904-28399-1-git-send-email-nicolas.pitre@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The core idle loop now takes care of it. However a few things need checking: - Invocation of cpuidle_idle_call() in pseries_lpar_idle() happened through arch_cpu_idle() and was therefore always preceded by a call to ppc64_runlatch_off(). To preserve this property now that cpuidle_idle_call() is invoked directly from core code, a call to ppc64_runlatch_off() has been added to idle_loop_prolog() in platforms/pseries/processor_idle.c. - Similarly, cpuidle_idle_call() was followed by ppc64_runlatch_off() so a call to the later has been added to idle_loop_epilog(). - And since arch_cpu_idle() always made sure to re-enable IRQs if they were not enabled, this is now done in idle_loop_epilog() as well. The above was made in order to keep the execution flow close to the original. I don't know if that was strictly necessary. Someone well aquainted with the platform details might find some room for possible optimizations. Signed-off-by: Nicolas Pitre --- arch/powerpc/platforms/pseries/processor_idle.c | 5 ++++ arch/powerpc/platforms/pseries/setup.c | 34 ++++++++++--------------- 2 files changed, 19 insertions(+), 20 deletions(-) diff --git a/arch/powerpc/platforms/pseries/processor_idle.c b/arch/powerpc/platforms/pseries/processor_idle.c index a166e38bd6..72ddfe3d2f 100644 --- a/arch/powerpc/platforms/pseries/processor_idle.c +++ b/arch/powerpc/platforms/pseries/processor_idle.c @@ -33,6 +33,7 @@ static struct cpuidle_state *cpuidle_state_table; static inline void idle_loop_prolog(unsigned long *in_purr) { + ppc64_runlatch_off(); *in_purr = mfspr(SPRN_PURR); /* * Indicate to the HV that we are idle. Now would be @@ -49,6 +50,10 @@ static inline void idle_loop_epilog(unsigned long in_purr) wait_cycles += mfspr(SPRN_PURR) - in_purr; get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles); get_lppaca()->idle = 0; + + if (irqs_disabled()) + local_irq_enable(); + ppc64_runlatch_on(); } static int snooze_loop(struct cpuidle_device *dev, diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index c1f1908587..7604c19d54 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -39,7 +39,6 @@ #include #include #include -#include #include #include @@ -356,29 +355,24 @@ early_initcall(alloc_dispatch_log_kmem_cache); static void pseries_lpar_idle(void) { - /* This would call on the cpuidle framework, and the back-end pseries - * driver to go to idle states + /* + * Default handler to go into low thread priority and possibly + * low power mode by cedeing processor to hypervisor */ - if (cpuidle_idle_call()) { - /* On error, execute default handler - * to go into low thread priority and possibly - * low power mode by cedeing processor to hypervisor - */ - /* Indicate to hypervisor that we are idle. */ - get_lppaca()->idle = 1; + /* Indicate to hypervisor that we are idle. */ + get_lppaca()->idle = 1; - /* - * Yield the processor to the hypervisor. We return if - * an external interrupt occurs (which are driven prior - * to returning here) or if a prod occurs from another - * processor. When returning here, external interrupts - * are enabled. - */ - cede_processor(); + /* + * Yield the processor to the hypervisor. We return if + * an external interrupt occurs (which are driven prior + * to returning here) or if a prod occurs from another + * processor. When returning here, external interrupts + * are enabled. + */ + cede_processor(); - get_lppaca()->idle = 0; - } + get_lppaca()->idle = 0; } /* -- 1.8.4.108.g55ea5f6 -- 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/