From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754431Ab1IMFnC (ORCPT ); Tue, 13 Sep 2011 01:43:02 -0400 Received: from na3sys009aog102.obsmtp.com ([74.125.149.69]:49790 "EHLO na3sys009aog102.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754221Ab1IMFm7 (ORCPT ); Tue, 13 Sep 2011 01:42:59 -0400 Message-ID: <4E6EED5B.3050304@ti.com> Date: Tue, 13 Sep 2011 11:12:51 +0530 From: Santosh User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.18) Gecko/20110617 Thunderbird/3.1.11 MIME-Version: 1.0 To: Andrew Morton CC: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux@arm.linux.org.uk, ccross@android.com, rjw@sisk.pl, khilman@ti.com, linux-arch@vger.kernel.org Subject: Re: [PATCH v2 1/5] cpu_pm: Add cpu power management notifiers References: <1315060755-4613-1-git-send-email-santosh.shilimkar@ti.com> <1315060755-4613-2-git-send-email-santosh.shilimkar@ti.com> <20110909155632.661f5696.akpm@linux-foundation.org> <4E6B2E6E.7010807@ti.com> <4E6D924F.9050605@ti.com> In-Reply-To: <4E6D924F.9050605@ti.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ( CC'ing linux-arch@vger.kernel.org) On Monday 12 September 2011 10:32 AM, Santosh wrote: > On Saturday 10 September 2011 03:01 PM, Santosh wrote: >> Andrew, >> >> On Saturday 10 September 2011 04:26 AM, Andrew Morton wrote: >>> On Sat, 3 Sep 2011 20:09:11 +0530 >>> Santosh Shilimkar wrote: >> >> [...] >> >>> >>> Have you identified which indivudual you hope/expect to merge this into >>> mainline? >>> >>> The code is presumably and hopefully applicable to architectures other >>> than ARM, yes? Can you suggest likely candidate architectures so we >>> can go off and bug the relevant maintainers to review it? >>> >> Sorry I missed above question in last email. Am not too sure but any >> arch which has CPU local timers, interrupt controller, Floating point >> co-processor etc, should be able to make use of it. So it's applicable >> to any architecture, but whether they want to use it, i don't know. >> >> As you noticed most of the ARM machine's are adapting to it. >> Along with generic patch, there are couple ARM drivers adapting >> to make use of it. That was the reason I was pushing this series >> via Russell's tree. >> > Here is an updated patch addressing your comments. > Attaching the same in case mailer eats spaces. > > From 6a0ef5d42da459d9eba0a5f396e6d9a95d3f94ff Mon Sep 17 00:00:00 2001 > From: Colin Cross > Date: Thu, 10 Feb 2011 02:04:45 -0800 > Subject: [PATCH 1/5] cpu_pm: Add cpu power management notifiers > > During some CPU power modes entered during idle, hotplug and > suspend, peripherals located in the CPU power domain, such as > the GIC, localtimers, and VFP, may be powered down. Add a > notifier chain that allows drivers for those peripherals to > be notified before and after they may be reset. > > Notified drivers can include VFP co-processor, interrupt controller > and it's PM extensions, local CPU timers context save/restore which > shouldn't be interrupted. Hence CPU PM event APIs must be called > with interrupts disabled. > > Signed-off-by: Colin Cross > Signed-off-by: Santosh Shilimkar > Reviewed-by: Kevin Hilman > Tested-and-Acked-by: Shawn Guo > Tested-by: Kevin Hilman > --- > include/linux/cpu_pm.h | 109 ++++++++++++++++++++++++++ > kernel/Makefile | 1 + > kernel/cpu_pm.c | 200 ++++++++++++++++++++++++++++++++++++++++++++++++ > kernel/power/Kconfig | 4 + > 4 files changed, 314 insertions(+), 0 deletions(-) > create mode 100644 include/linux/cpu_pm.h > create mode 100644 kernel/cpu_pm.c > > diff --git a/include/linux/cpu_pm.h b/include/linux/cpu_pm.h > new file mode 100644 > index 0000000..455b233 > --- /dev/null > +++ b/include/linux/cpu_pm.h > @@ -0,0 +1,109 @@ > +/* > + * Copyright (C) 2011 Google, Inc. > + * > + * Author: > + * Colin Cross > + * > + * This software is licensed under the terms of the GNU General Public > + * License version 2, as published by the Free Software Foundation, and > + * may be copied, distributed, and modified under those terms. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > + > +#ifndef _LINUX_CPU_PM_H > +#define _LINUX_CPU_PM_H > + > +#include > +#include > + > +/* > + * When a CPU goes to a low power state that turns off power to the CPU's > + * power domain, the contents of some blocks (floating point coprocessors, > + * interrupt controllers, caches, timers) in the same power domain can > + * be lost. The cpm_pm notifiers provide a method for platform idle, > suspend, > + * and hotplug implementations to notify the drivers for these blocks that > + * they may be reset. > + * > + * All cpu_pm notifications must be called with interrupts disabled. > + * > + * The notifications are split into two classes: CPU notifications and CPU > + * cluster notifications. > + * > + * CPU notifications apply to a single CPU and must be called on the > affected > + * CPU. They are used to save per-cpu context for affected blocks. > + * > + * CPU cluster notifications apply to all CPUs in a single power > domain. They > + * are used to save any global context for affected blocks, and must be > called > + * after all the CPUs in the power domain have been notified of the low > power > + * state. > + */ > + > +/* > + * Event codes passed as unsigned long val to notifier calls > + */ > +enum cpu_pm_event { > + /* A single cpu is entering a low power state */ > + CPU_PM_ENTER, > + > + /* A single cpu failed to enter a low power state */ > + CPU_PM_ENTER_FAILED, > + > + /* A single cpu is exiting a low power state */ > + CPU_PM_EXIT, > + > + /* A cpu power domain is entering a low power state */ > + CPU_CLUSTER_PM_ENTER, > + > + /* A cpu power domain failed to enter a low power state */ > + CPU_CLUSTER_PM_ENTER_FAILED, > + > + /* A cpu power domain is exiting a low power state */ > + CPU_CLUSTER_PM_EXIT, > +}; > + > +#ifdef CONFIG_CPU_PM > +int cpu_pm_register_notifier(struct notifier_block *nb); > +int cpu_pm_unregister_notifier(struct notifier_block *nb); > +int cpu_pm_enter(void); > +int cpu_pm_exit(void); > +int cpu_cluster_pm_enter(void); > +int cpu_cluster_pm_exit(void); > + > +#else > + > +static inline int cpu_pm_register_notifier(struct notifier_block *nb) > +{ > + return 0; > +} > + > +static inline int cpu_pm_unregister_notifier(struct notifier_block *nb) > +{ > + return 0; > +} > + > +static inline int cpu_pm_enter(void) > +{ > + return 0; > +} > + > +static inline int cpu_pm_exit(void) > +{ > + return 0; > +} > + > +static inline int cpu_cluster_pm_enter(void) > +{ > + return 0; > +} > + > +static inline int cpu_cluster_pm_exit(void) > +{ > + return 0; > +} > +#endif > +#endif > diff --git a/kernel/Makefile b/kernel/Makefile > index eca595e..988cb3d 100644 > --- a/kernel/Makefile > +++ b/kernel/Makefile > @@ -101,6 +101,7 @@ obj-$(CONFIG_RING_BUFFER) += trace/ > obj-$(CONFIG_TRACEPOINTS) += trace/ > obj-$(CONFIG_SMP) += sched_cpupri.o > obj-$(CONFIG_IRQ_WORK) += irq_work.o > +obj-$(CONFIG_CPU_PM) += cpu_pm.o > > obj-$(CONFIG_PERF_EVENTS) += events/ > > diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c > new file mode 100644 > index 0000000..4d1ff4a > --- /dev/null > +++ b/kernel/cpu_pm.c > @@ -0,0 +1,200 @@ > +/* > + * Copyright (C) 2011 Google, Inc. > + * > + * Author: > + * Colin Cross > + * > + * This software is licensed under the terms of the GNU General Public > + * License version 2, as published by the Free Software Foundation, and > + * may be copied, distributed, and modified under those terms. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +static DEFINE_RWLOCK(cpu_pm_notifier_lock); > +static RAW_NOTIFIER_HEAD(cpu_pm_notifier_chain); > + > +static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int > *nr_calls) > +{ > + int ret; > + > + ret = __raw_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL, > + nr_to_call, nr_calls); > + > + return notifier_to_errno(ret); > +} > + > +/** > + * cpu_pm_register_notifier - register a driver with cpu_pm > + * @nb: notifier block to register > + * > + * Add a driver to a list of drivers that are notified about > + * CPU and CPU cluster low power entry and exit. > + * > + * This function may sleep, and has the same return conditions as > + * raw_notifier_chain_register. > + */ > +int cpu_pm_register_notifier(struct notifier_block *nb) > +{ > + unsigned long flags; > + int ret; > + > + write_lock_irqsave(&cpu_pm_notifier_lock, flags); > + ret = raw_notifier_chain_register(&cpu_pm_notifier_chain, nb); > + write_unlock_irqrestore(&cpu_pm_notifier_lock, flags); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_pm_register_notifier); > + > +/** > + * cpu_pm_unregister_notifier - unregister a driver with cpu_pm > + * @nb: notifier block to be unregistered > + * > + * Remove a driver from the CPU PM notifier list. > + * > + * This function may sleep, and has the same return conditions as > + * raw_notifier_chain_unregister. > + */ > +int cpu_pm_unregister_notifier(struct notifier_block *nb) > +{ > + unsigned long flags; > + int ret; > + > + write_lock_irqsave(&cpu_pm_notifier_lock, flags); > + ret = raw_notifier_chain_unregister(&cpu_pm_notifier_chain, nb); > + write_unlock_irqrestore(&cpu_pm_notifier_lock, flags); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_pm_unregister_notifier); > + > +/** > + * cpm_pm_enter - CPU low power entry notifier > + * > + * Notifies listeners that a single CPU is entering a low power state > that may > + * cause some blocks in the same power domain as the cpu to reset. > + * > + * Must be called on the affected CPU with interrupts disabled. > Platform is > + * responsible for ensuring that cpu_pm_enter is not called twice on > the same > + * CPU before cpu_pm_exit is called. Notified drivers can include VFP > + * co-processor, interrupt controller and it's PM extensions, local CPU > + * timers context save/restore which shouldn't be interrupted. Hence it > + * must be called with interrupts disabled. > + * > + * Return conditions are same as __raw_notifier_call_chain. > + */ > +int cpu_pm_enter(void) > +{ > + int nr_calls; > + int ret = 0; > + > + read_lock(&cpu_pm_notifier_lock); > + ret = cpu_pm_notify(CPU_PM_ENTER, -1, &nr_calls); > + if (ret) > + /* > + * Inform listeners (nr_calls - 1) about failure of CPU PM > + * PM entry who are notified earlier to prepare for it. > + */ > + cpu_pm_notify(CPU_PM_ENTER_FAILED, nr_calls - 1, NULL); > + read_unlock(&cpu_pm_notifier_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_pm_enter); > + > +/** > + * cpm_pm_exit - CPU low power exit notifier > + * > + * Notifies listeners that a single CPU is exiting a low power state > that may > + * have caused some blocks in the same power domain as the cpu to reset. > + * > + * Notified drivers can include VFP co-processor, interrupt controller > + * and it's PM extensions, local CPU timers context save/restore which > + * shouldn't be interrupted. Hence it must be called with interrupts > disabled. > + * > + * Return conditions are same as __raw_notifier_call_chain. > + */ > +int cpu_pm_exit(void) > +{ > + int ret; > + > + read_lock(&cpu_pm_notifier_lock); > + ret = cpu_pm_notify(CPU_PM_EXIT, -1, NULL); > + read_unlock(&cpu_pm_notifier_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_pm_exit); > + > +/** > + * cpm_cluster_pm_enter - CPU cluster low power entry notifier > + * > + * Notifies listeners that all cpus in a power domain are entering a > low power > + * state that may cause some blocks in the same power domain to reset. > + * > + * Must be called after cpu_pm_enter has been called on all cpus in the > power > + * domain, and before cpu_pm_exit has been called on any cpu in the power > + * domain. Notified drivers can include VFP co-processor, interrupt > controller > + * and it's PM extensions, local CPU timers context save/restore which > + * shouldn't be interrupted. Hence it must be called with interrupts > disabled. > + * > + * Must be called with interrupts disabled. > + * > + * Return conditions are same as __raw_notifier_call_chain. > + */ > +int cpu_cluster_pm_enter(void) > +{ > + int nr_calls; > + int ret = 0; > + > + read_lock(&cpu_pm_notifier_lock); > + ret = cpu_pm_notify(CPU_CLUSTER_PM_ENTER, -1, &nr_calls); > + if (ret) > + /* > + * Inform listeners (nr_calls - 1) about failure of CPU cluster > + * PM entry who are notified earlier to prepare for it. > + */ > + cpu_pm_notify(CPU_CLUSTER_PM_ENTER_FAILED, nr_calls - 1, NULL); > + read_unlock(&cpu_pm_notifier_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_cluster_pm_enter); > + > +/** > + * cpm_cluster_pm_exit - CPU cluster low power exit notifier > + * > + * Notifies listeners that all cpus in a power domain are exiting form a > + * low power state that may have caused some blocks in the same power > domain > + * to reset. > + * > + * Must be called after cpu_pm_exit has been called on all cpus in the > power > + * domain, and before cpu_pm_exit has been called on any cpu in the power > + * domain. Notified drivers can include VFP co-processor, interrupt > controller > + * and it's PM extensions, local CPU timers context save/restore which > + * shouldn't be interrupted. Hence it must be called with interrupts > disabled. > + * > + * Return conditions are same as __raw_notifier_call_chain. > + */ > +int cpu_cluster_pm_exit(void) > +{ > + int ret; > + > + read_lock(&cpu_pm_notifier_lock); > + ret = cpu_pm_notify(CPU_CLUSTER_PM_EXIT, -1, NULL); > + read_unlock(&cpu_pm_notifier_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_cluster_pm_exit); > diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig > index 3744c59..80a8597 100644 > --- a/kernel/power/Kconfig > +++ b/kernel/power/Kconfig > @@ -235,3 +235,7 @@ config PM_GENERIC_DOMAINS > config PM_GENERIC_DOMAINS_RUNTIME > def_bool y > depends on PM_RUNTIME && PM_GENERIC_DOMAINS > + > +config CPU_PM > + bool > + depends on SUSPEND || CPU_IDLE From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Santosh) Date: Tue, 13 Sep 2011 11:12:51 +0530 Subject: [PATCH v2 1/5] cpu_pm: Add cpu power management notifiers In-Reply-To: <4E6D924F.9050605@ti.com> References: <1315060755-4613-1-git-send-email-santosh.shilimkar@ti.com> <1315060755-4613-2-git-send-email-santosh.shilimkar@ti.com> <20110909155632.661f5696.akpm@linux-foundation.org> <4E6B2E6E.7010807@ti.com> <4E6D924F.9050605@ti.com> Message-ID: <4E6EED5B.3050304@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org ( CC'ing linux-arch at vger.kernel.org) On Monday 12 September 2011 10:32 AM, Santosh wrote: > On Saturday 10 September 2011 03:01 PM, Santosh wrote: >> Andrew, >> >> On Saturday 10 September 2011 04:26 AM, Andrew Morton wrote: >>> On Sat, 3 Sep 2011 20:09:11 +0530 >>> Santosh Shilimkar wrote: >> >> [...] >> >>> >>> Have you identified which indivudual you hope/expect to merge this into >>> mainline? >>> >>> The code is presumably and hopefully applicable to architectures other >>> than ARM, yes? Can you suggest likely candidate architectures so we >>> can go off and bug the relevant maintainers to review it? >>> >> Sorry I missed above question in last email. Am not too sure but any >> arch which has CPU local timers, interrupt controller, Floating point >> co-processor etc, should be able to make use of it. So it's applicable >> to any architecture, but whether they want to use it, i don't know. >> >> As you noticed most of the ARM machine's are adapting to it. >> Along with generic patch, there are couple ARM drivers adapting >> to make use of it. That was the reason I was pushing this series >> via Russell's tree. >> > Here is an updated patch addressing your comments. > Attaching the same in case mailer eats spaces. > > From 6a0ef5d42da459d9eba0a5f396e6d9a95d3f94ff Mon Sep 17 00:00:00 2001 > From: Colin Cross > Date: Thu, 10 Feb 2011 02:04:45 -0800 > Subject: [PATCH 1/5] cpu_pm: Add cpu power management notifiers > > During some CPU power modes entered during idle, hotplug and > suspend, peripherals located in the CPU power domain, such as > the GIC, localtimers, and VFP, may be powered down. Add a > notifier chain that allows drivers for those peripherals to > be notified before and after they may be reset. > > Notified drivers can include VFP co-processor, interrupt controller > and it's PM extensions, local CPU timers context save/restore which > shouldn't be interrupted. Hence CPU PM event APIs must be called > with interrupts disabled. > > Signed-off-by: Colin Cross > Signed-off-by: Santosh Shilimkar > Reviewed-by: Kevin Hilman > Tested-and-Acked-by: Shawn Guo > Tested-by: Kevin Hilman > --- > include/linux/cpu_pm.h | 109 ++++++++++++++++++++++++++ > kernel/Makefile | 1 + > kernel/cpu_pm.c | 200 ++++++++++++++++++++++++++++++++++++++++++++++++ > kernel/power/Kconfig | 4 + > 4 files changed, 314 insertions(+), 0 deletions(-) > create mode 100644 include/linux/cpu_pm.h > create mode 100644 kernel/cpu_pm.c > > diff --git a/include/linux/cpu_pm.h b/include/linux/cpu_pm.h > new file mode 100644 > index 0000000..455b233 > --- /dev/null > +++ b/include/linux/cpu_pm.h > @@ -0,0 +1,109 @@ > +/* > + * Copyright (C) 2011 Google, Inc. > + * > + * Author: > + * Colin Cross > + * > + * This software is licensed under the terms of the GNU General Public > + * License version 2, as published by the Free Software Foundation, and > + * may be copied, distributed, and modified under those terms. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > + > +#ifndef _LINUX_CPU_PM_H > +#define _LINUX_CPU_PM_H > + > +#include > +#include > + > +/* > + * When a CPU goes to a low power state that turns off power to the CPU's > + * power domain, the contents of some blocks (floating point coprocessors, > + * interrupt controllers, caches, timers) in the same power domain can > + * be lost. The cpm_pm notifiers provide a method for platform idle, > suspend, > + * and hotplug implementations to notify the drivers for these blocks that > + * they may be reset. > + * > + * All cpu_pm notifications must be called with interrupts disabled. > + * > + * The notifications are split into two classes: CPU notifications and CPU > + * cluster notifications. > + * > + * CPU notifications apply to a single CPU and must be called on the > affected > + * CPU. They are used to save per-cpu context for affected blocks. > + * > + * CPU cluster notifications apply to all CPUs in a single power > domain. They > + * are used to save any global context for affected blocks, and must be > called > + * after all the CPUs in the power domain have been notified of the low > power > + * state. > + */ > + > +/* > + * Event codes passed as unsigned long val to notifier calls > + */ > +enum cpu_pm_event { > + /* A single cpu is entering a low power state */ > + CPU_PM_ENTER, > + > + /* A single cpu failed to enter a low power state */ > + CPU_PM_ENTER_FAILED, > + > + /* A single cpu is exiting a low power state */ > + CPU_PM_EXIT, > + > + /* A cpu power domain is entering a low power state */ > + CPU_CLUSTER_PM_ENTER, > + > + /* A cpu power domain failed to enter a low power state */ > + CPU_CLUSTER_PM_ENTER_FAILED, > + > + /* A cpu power domain is exiting a low power state */ > + CPU_CLUSTER_PM_EXIT, > +}; > + > +#ifdef CONFIG_CPU_PM > +int cpu_pm_register_notifier(struct notifier_block *nb); > +int cpu_pm_unregister_notifier(struct notifier_block *nb); > +int cpu_pm_enter(void); > +int cpu_pm_exit(void); > +int cpu_cluster_pm_enter(void); > +int cpu_cluster_pm_exit(void); > + > +#else > + > +static inline int cpu_pm_register_notifier(struct notifier_block *nb) > +{ > + return 0; > +} > + > +static inline int cpu_pm_unregister_notifier(struct notifier_block *nb) > +{ > + return 0; > +} > + > +static inline int cpu_pm_enter(void) > +{ > + return 0; > +} > + > +static inline int cpu_pm_exit(void) > +{ > + return 0; > +} > + > +static inline int cpu_cluster_pm_enter(void) > +{ > + return 0; > +} > + > +static inline int cpu_cluster_pm_exit(void) > +{ > + return 0; > +} > +#endif > +#endif > diff --git a/kernel/Makefile b/kernel/Makefile > index eca595e..988cb3d 100644 > --- a/kernel/Makefile > +++ b/kernel/Makefile > @@ -101,6 +101,7 @@ obj-$(CONFIG_RING_BUFFER) += trace/ > obj-$(CONFIG_TRACEPOINTS) += trace/ > obj-$(CONFIG_SMP) += sched_cpupri.o > obj-$(CONFIG_IRQ_WORK) += irq_work.o > +obj-$(CONFIG_CPU_PM) += cpu_pm.o > > obj-$(CONFIG_PERF_EVENTS) += events/ > > diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c > new file mode 100644 > index 0000000..4d1ff4a > --- /dev/null > +++ b/kernel/cpu_pm.c > @@ -0,0 +1,200 @@ > +/* > + * Copyright (C) 2011 Google, Inc. > + * > + * Author: > + * Colin Cross > + * > + * This software is licensed under the terms of the GNU General Public > + * License version 2, as published by the Free Software Foundation, and > + * may be copied, distributed, and modified under those terms. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +static DEFINE_RWLOCK(cpu_pm_notifier_lock); > +static RAW_NOTIFIER_HEAD(cpu_pm_notifier_chain); > + > +static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int > *nr_calls) > +{ > + int ret; > + > + ret = __raw_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL, > + nr_to_call, nr_calls); > + > + return notifier_to_errno(ret); > +} > + > +/** > + * cpu_pm_register_notifier - register a driver with cpu_pm > + * @nb: notifier block to register > + * > + * Add a driver to a list of drivers that are notified about > + * CPU and CPU cluster low power entry and exit. > + * > + * This function may sleep, and has the same return conditions as > + * raw_notifier_chain_register. > + */ > +int cpu_pm_register_notifier(struct notifier_block *nb) > +{ > + unsigned long flags; > + int ret; > + > + write_lock_irqsave(&cpu_pm_notifier_lock, flags); > + ret = raw_notifier_chain_register(&cpu_pm_notifier_chain, nb); > + write_unlock_irqrestore(&cpu_pm_notifier_lock, flags); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_pm_register_notifier); > + > +/** > + * cpu_pm_unregister_notifier - unregister a driver with cpu_pm > + * @nb: notifier block to be unregistered > + * > + * Remove a driver from the CPU PM notifier list. > + * > + * This function may sleep, and has the same return conditions as > + * raw_notifier_chain_unregister. > + */ > +int cpu_pm_unregister_notifier(struct notifier_block *nb) > +{ > + unsigned long flags; > + int ret; > + > + write_lock_irqsave(&cpu_pm_notifier_lock, flags); > + ret = raw_notifier_chain_unregister(&cpu_pm_notifier_chain, nb); > + write_unlock_irqrestore(&cpu_pm_notifier_lock, flags); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_pm_unregister_notifier); > + > +/** > + * cpm_pm_enter - CPU low power entry notifier > + * > + * Notifies listeners that a single CPU is entering a low power state > that may > + * cause some blocks in the same power domain as the cpu to reset. > + * > + * Must be called on the affected CPU with interrupts disabled. > Platform is > + * responsible for ensuring that cpu_pm_enter is not called twice on > the same > + * CPU before cpu_pm_exit is called. Notified drivers can include VFP > + * co-processor, interrupt controller and it's PM extensions, local CPU > + * timers context save/restore which shouldn't be interrupted. Hence it > + * must be called with interrupts disabled. > + * > + * Return conditions are same as __raw_notifier_call_chain. > + */ > +int cpu_pm_enter(void) > +{ > + int nr_calls; > + int ret = 0; > + > + read_lock(&cpu_pm_notifier_lock); > + ret = cpu_pm_notify(CPU_PM_ENTER, -1, &nr_calls); > + if (ret) > + /* > + * Inform listeners (nr_calls - 1) about failure of CPU PM > + * PM entry who are notified earlier to prepare for it. > + */ > + cpu_pm_notify(CPU_PM_ENTER_FAILED, nr_calls - 1, NULL); > + read_unlock(&cpu_pm_notifier_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_pm_enter); > + > +/** > + * cpm_pm_exit - CPU low power exit notifier > + * > + * Notifies listeners that a single CPU is exiting a low power state > that may > + * have caused some blocks in the same power domain as the cpu to reset. > + * > + * Notified drivers can include VFP co-processor, interrupt controller > + * and it's PM extensions, local CPU timers context save/restore which > + * shouldn't be interrupted. Hence it must be called with interrupts > disabled. > + * > + * Return conditions are same as __raw_notifier_call_chain. > + */ > +int cpu_pm_exit(void) > +{ > + int ret; > + > + read_lock(&cpu_pm_notifier_lock); > + ret = cpu_pm_notify(CPU_PM_EXIT, -1, NULL); > + read_unlock(&cpu_pm_notifier_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_pm_exit); > + > +/** > + * cpm_cluster_pm_enter - CPU cluster low power entry notifier > + * > + * Notifies listeners that all cpus in a power domain are entering a > low power > + * state that may cause some blocks in the same power domain to reset. > + * > + * Must be called after cpu_pm_enter has been called on all cpus in the > power > + * domain, and before cpu_pm_exit has been called on any cpu in the power > + * domain. Notified drivers can include VFP co-processor, interrupt > controller > + * and it's PM extensions, local CPU timers context save/restore which > + * shouldn't be interrupted. Hence it must be called with interrupts > disabled. > + * > + * Must be called with interrupts disabled. > + * > + * Return conditions are same as __raw_notifier_call_chain. > + */ > +int cpu_cluster_pm_enter(void) > +{ > + int nr_calls; > + int ret = 0; > + > + read_lock(&cpu_pm_notifier_lock); > + ret = cpu_pm_notify(CPU_CLUSTER_PM_ENTER, -1, &nr_calls); > + if (ret) > + /* > + * Inform listeners (nr_calls - 1) about failure of CPU cluster > + * PM entry who are notified earlier to prepare for it. > + */ > + cpu_pm_notify(CPU_CLUSTER_PM_ENTER_FAILED, nr_calls - 1, NULL); > + read_unlock(&cpu_pm_notifier_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_cluster_pm_enter); > + > +/** > + * cpm_cluster_pm_exit - CPU cluster low power exit notifier > + * > + * Notifies listeners that all cpus in a power domain are exiting form a > + * low power state that may have caused some blocks in the same power > domain > + * to reset. > + * > + * Must be called after cpu_pm_exit has been called on all cpus in the > power > + * domain, and before cpu_pm_exit has been called on any cpu in the power > + * domain. Notified drivers can include VFP co-processor, interrupt > controller > + * and it's PM extensions, local CPU timers context save/restore which > + * shouldn't be interrupted. Hence it must be called with interrupts > disabled. > + * > + * Return conditions are same as __raw_notifier_call_chain. > + */ > +int cpu_cluster_pm_exit(void) > +{ > + int ret; > + > + read_lock(&cpu_pm_notifier_lock); > + ret = cpu_pm_notify(CPU_CLUSTER_PM_EXIT, -1, NULL); > + read_unlock(&cpu_pm_notifier_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cpu_cluster_pm_exit); > diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig > index 3744c59..80a8597 100644 > --- a/kernel/power/Kconfig > +++ b/kernel/power/Kconfig > @@ -235,3 +235,7 @@ config PM_GENERIC_DOMAINS > config PM_GENERIC_DOMAINS_RUNTIME > def_bool y > depends on PM_RUNTIME && PM_GENERIC_DOMAINS > + > +config CPU_PM > + bool > + depends on SUSPEND || CPU_IDLE