From patchwork Fri Jul 26 05:21:14 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: preeti X-Patchwork-Id: 2833788 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 136AFC0319 for ; Fri, 26 Jul 2013 05:24:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 48E1320181 for ; Fri, 26 Jul 2013 05:24:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 549DA2017C for ; Fri, 26 Jul 2013 05:24:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751337Ab3GZFYt (ORCPT ); Fri, 26 Jul 2013 01:24:49 -0400 Received: from e23smtp06.au.ibm.com ([202.81.31.148]:45438 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751116Ab3GZFYs (ORCPT ); Fri, 26 Jul 2013 01:24:48 -0400 Received: from /spool/local by e23smtp06.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Fri, 26 Jul 2013 15:16:53 +1000 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [9.190.234.120]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 38B402CE8052; Fri, 26 Jul 2013 15:24:45 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r6Q59B7R23724114; Fri, 26 Jul 2013 15:09:18 +1000 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r6Q5OWmb008847; Fri, 26 Jul 2013 15:24:36 +1000 Received: from [192.168.2.6] ([9.124.213.205]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r6Q5NWYu007140; Fri, 26 Jul 2013 15:24:21 +1000 Subject: [Resend RFC PATCH 5/5] cpuidle/ppc: Add longnap state to the idle states on powernv To: benh@kernel.crashing.org, paul.gortmaker@windriver.com, paulus@samba.org, shangw@linux.vnet.ibm.com, galak@kernel.crashing.org, fweisbec@gmail.com, paulmck@linux.vnet.ibm.com, michael@ellerman.id.au, arnd@arndb.de, linux-pm@vger.kernel.org, rostedt@goodmis.org, rjw@sisk.pl, john.stultz@linaro.org, tglx@linutronix.de, chenhui.zhao@freescale.com, deepthi@linux.vnet.ibm.com, geoff@infradead.org, linux-kernel@vger.kernel.org, srivatsa.bhat@linux.vnet.ibm.com, schwidefsky@de.ibm.com, svaidy@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org From: Preeti U Murthy Date: Fri, 26 Jul 2013 10:51:14 +0530 Message-ID: <20130726052040.17167.21530.stgit@preeti> In-Reply-To: <20130726050915.17167.16298.stgit@preeti> References: <20130726050915.17167.16298.stgit@preeti> User-Agent: StGit/0.16-38-g167d MIME-Version: 1.0 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13072605-7014-0000-0000-00000361506F Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch hooks into the existing broadcast framework with the support that this patchset introduces for ppc, and the cpuidle driver backend for powernv(posted out recently by Deepthi Dharwar) to add sleep state as one of the deep idle states, in which the decrementer is switched off. However in this patch, we only emulate sleep by going into a state which does a nap with the decrementer interrupts disabled, termed as longnap. This enables focus on the timer broadcast framework for ppc in this series of patches , which is required as a first step to enable sleep on ppc. Signed-off-by: Preeti U Murthy --- arch/powerpc/platforms/powernv/processor_idle.c | 48 +++++++++++++++++++++++ 1 file changed, 47 insertions(+), 1 deletion(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/powerpc/platforms/powernv/processor_idle.c b/arch/powerpc/platforms/powernv/processor_idle.c index f43ad91a..9aca502 100644 --- a/arch/powerpc/platforms/powernv/processor_idle.c +++ b/arch/powerpc/platforms/powernv/processor_idle.c @@ -9,16 +9,18 @@ #include #include #include +#include #include #include +#include struct cpuidle_driver powernv_idle_driver = { .name = "powernv_idle", .owner = THIS_MODULE, }; -#define MAX_IDLE_STATE_COUNT 2 +#define MAX_IDLE_STATE_COUNT 3 static int max_idle_state = MAX_IDLE_STATE_COUNT - 1; static struct cpuidle_device __percpu *powernv_cpuidle_devices; @@ -54,6 +56,43 @@ static int nap_loop(struct cpuidle_device *dev, return index; } +/* Emulate sleep, with long nap. + * During sleep, the core does not receive decrementer interrupts. + * Emulate sleep using long nap with decrementers interrupts disabled. + * This is an initial prototype to test the timer offload framework for ppc. + * We will eventually introduce the sleep state once the timer offload framework + * for ppc is stable. + */ +static int longnap_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + int cpu = dev->cpu; + + unsigned long lpcr = mfspr(SPRN_LPCR); + + lpcr &= ~(LPCR_MER | LPCR_PECE); /* lpcr[mer] must be 0 */ + + /* exit powersave upon external interrupt, but not decrementer + * interrupt, Emulate sleep. + */ + lpcr |= LPCR_PECE0; + + if (cpu != bc_cpu) { + mtspr(SPRN_LPCR, lpcr); + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu); + power7_nap(); + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu); + } else { + /* Wakeup on a decrementer interrupt, Do a nap */ + lpcr |= LPCR_PECE1; + mtspr(SPRN_LPCR, lpcr); + power7_nap(); + } + + return index; +} + /* * States for dedicated partition case. */ @@ -72,6 +111,13 @@ static struct cpuidle_state powernv_states[MAX_IDLE_STATE_COUNT] = { .exit_latency = 10, .target_residency = 100, .enter = &nap_loop }, + { /* LongNap */ + .name = "LongNap", + .desc = "LongNap", + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 10, + .target_residency = 100, + .enter = &longnap_loop }, }; static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,