From patchwork Wed Jan 15 08:10:11 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Preeti U Murthy X-Patchwork-Id: 311015 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 4AAE22C035C for ; Wed, 15 Jan 2014 19:16:32 +1100 (EST) Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id A8ED92C06FF for ; Wed, 15 Jan 2014 19:13:52 +1100 (EST) Received: from /spool/local by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 15 Jan 2014 01:13:48 -0700 Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 4651D1FF001B for ; Wed, 15 Jan 2014 01:13:17 -0700 (MST) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by b03cxnp08026.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s0F8DavF7602684 for ; Wed, 15 Jan 2014 09:13:36 +0100 Received: from d03av02.boulder.ibm.com (localhost [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s0F8Di1w018453 for ; Wed, 15 Jan 2014 01:13:47 -0700 Received: from preeti.in.ibm.com ([9.124.220.147]) by d03av02.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id s0F8DWqV017798; Wed, 15 Jan 2014 01:13:33 -0700 Subject: [PATCH V5 7/8] cpuidle/powernv: Add "Fast-Sleep" CPU idle state To: daniel.lezcano@linaro.org, peterz@infradead.org, fweisbec@gmail.com, agraf@suse.de, paul.gortmaker@windriver.com, paulus@samba.org, mingo@kernel.org, mikey@neuling.org, shangw@linux.vnet.ibm.com, rafael.j.wysocki@intel.com, galak@kernel.crashing.org, benh@kernel.crashing.org, paulmck@linux.vnet.ibm.com, arnd@arndb.de, linux-pm@vger.kernel.org, rostedt@goodmis.org, michael@ellerman.id.au, john.stultz@linaro.org, anton@samba.org, tglx@linutronix.de, chenhui.zhao@freescale.com, deepthi@linux.vnet.ibm.com, r58472@freescale.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: Wed, 15 Jan 2014 13:40:11 +0530 Message-ID: <20140115081011.20446.17305.stgit@preeti.in.ibm.com> In-Reply-To: <20140115080555.20446.27238.stgit@preeti.in.ibm.com> References: <20140115080555.20446.27238.stgit@preeti.in.ibm.com> User-Agent: StGit/0.16-38-g167d MIME-Version: 1.0 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14011508-7164-0000-0000-0000052135F4 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.16 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Fast sleep is one of the deep idle states on Power8 in which local timers of CPUs stop. On PowerPC we do not have an external clock device which can handle wakeup of such CPUs. Now that we have the support in the tick broadcast framework for archs that do not sport such a device and the low level support for fast sleep, enable it in the cpuidle framework on PowerNV. Signed-off-by: Preeti U Murthy --- arch/powerpc/Kconfig | 2 ++ arch/powerpc/kernel/time.c | 2 +- drivers/cpuidle/cpuidle-powernv.c | 39 +++++++++++++++++++++++++++++++++++++ 3 files changed, 42 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index b44b52c..cafa788 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -129,6 +129,8 @@ config PPC select GENERIC_CMOS_UPDATE select GENERIC_TIME_VSYSCALL_OLD select GENERIC_CLOCKEVENTS + select GENERIC_CLOCKEVENTS_BROADCAST + select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER select HAVE_MOD_ARCH_SPECIFIC diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 42cb603..d9efd93 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -106,7 +106,7 @@ struct clock_event_device decrementer_clockevent = { .irq = 0, .set_next_event = decrementer_set_next_event, .set_mode = decrementer_set_mode, - .features = CLOCK_EVT_FEAT_ONESHOT, + .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP, }; EXPORT_SYMBOL(decrementer_clockevent); diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index 78fd174..e3aa62f 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -49,6 +50,37 @@ static int nap_loop(struct cpuidle_device *dev, return index; } +static int fastsleep_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + int cpu = dev->cpu; + unsigned long old_lpcr = mfspr(SPRN_LPCR); + unsigned long new_lpcr; + + new_lpcr = old_lpcr; + new_lpcr &= ~(LPCR_MER | LPCR_PECE); /* lpcr[mer] must be 0 */ + + /* exit powersave upon external interrupt, but not decrementer + * interrupt, Emulate sleep. + */ + new_lpcr |= LPCR_PECE0; + + if (clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu)) { + new_lpcr |= LPCR_PECE1; + mtspr(SPRN_LPCR, new_lpcr); + power7_nap(); + } else { + mtspr(SPRN_LPCR, new_lpcr); + power7_sleep(); + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu); + } + + mtspr(SPRN_LPCR, old_lpcr); + + return index; +} + /* * States for dedicated partition case. */ @@ -67,6 +99,13 @@ static struct cpuidle_state powernv_states[] = { .exit_latency = 10, .target_residency = 100, .enter = &nap_loop }, + { /* Fastsleep */ + .name = "fastsleep", + .desc = "fastsleep", + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 10, + .target_residency = 100, + .enter = &fastsleep_loop }, }; static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,