From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 48C872C05BA for ; Wed, 22 Jan 2014 18:13:11 +1100 (EST) Received: from /spool/local by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 22 Jan 2014 00:13:09 -0700 Received: from b03cxnp08027.gho.boulder.ibm.com (b03cxnp08027.gho.boulder.ibm.com [9.17.130.19]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id 1C74919D8036 for ; Wed, 22 Jan 2014 00:12:57 -0700 (MST) Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by b03cxnp08027.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s0M7CqoX4915476 for ; Wed, 22 Jan 2014 08:12:52 +0100 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s0M7D4P6029855 for ; Wed, 22 Jan 2014 00:13:06 -0700 Subject: [RESEND PATCH V5 7/8] cpuidle/powernv: Add "Fast-Sleep" CPU idle state To: peterz@infradead.org, fweisbec@gmail.com, 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, =daniel.lezcano@linaro.org, benh@kernel.crashing.org, paulmck@linux.vnet.ibm.com, --to=agraf@suse.de, 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, 22 Jan 2014 12:39:32 +0530 Message-ID: <20140122070932.30650.88481.stgit@preeti.in.ibm.com> In-Reply-To: <20140122065918.30650.22437.stgit@preeti.in.ibm.com> References: <20140122065918.30650.22437.stgit@preeti.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 | 42 +++++++++++++++++++++++++++++++++++++ 3 files changed, 45 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index fa39517..ec91584 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 df2989b..95fa5ce 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..90f0c2b 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 +50,40 @@ 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; + + if (unlikely(system_state < SYSTEM_RUNNING)) + return index; + + 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 +102,13 @@ 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,