From 5f12a761937373d2f9b557d7519e6f1cf738b8f0 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 11 Aug 2011 12:31:20 +0100 Subject: perf: provide PMU when initing events Currently, an event's 'pmu' field is set after pmu::event_init() is called. This means that pmu::event_init() must figure out which struct pmu the event was initialised from. This makes it difficult to consolidate common event initialisation code for similar PMUs, and very difficult to implement drivers for PMUs which can have multiple instances (e.g. a USB controller PMU, a GPU PMU, etc). This patch sets the 'pmu' field before initialising the event, allowing event init code to identify the struct pmu instance easily. In the event of failure to initialise an event, the event is destroyed via kfree() without calling perf_event::destroy(), so this shouldn't result in bad behaviour even if the destroy field was set before failure to initialise was noted. Signed-off-by: Mark Rutland Reviewed-by: Will Deacon Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1313062280-19123-1-git-send-email-mark.rutland@arm.com Signed-off-by: Ingo Molnar --- kernel/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/events/core.c b/kernel/events/core.c index b8785e26ee1c..68c8017de969 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5715,6 +5715,7 @@ struct pmu *perf_init_event(struct perf_event *event) pmu = idr_find(&pmu_idr, event->attr.type); rcu_read_unlock(); if (pmu) { + event->pmu = pmu; ret = pmu->event_init(event); if (ret) pmu = ERR_PTR(ret); @@ -5722,6 +5723,7 @@ struct pmu *perf_init_event(struct perf_event *event) } list_for_each_entry_rcu(pmu, &pmus, entry) { + event->pmu = pmu; ret = pmu->event_init(event); if (!ret) goto unlock; @@ -5848,8 +5850,6 @@ done: return ERR_PTR(err); } - event->pmu = pmu; - if (!event->parent) { if (event->attach_state & PERF_ATTACH_TASK) jump_label_inc(&perf_sched_events); -- cgit v1.2.3 From ab10023e0088d5075354afc7cb9e72304757dddd Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Thu, 10 Feb 2011 02:04:45 -0800 Subject: 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 Tested-by: Vishwanath BS --- include/linux/cpu_pm.h | 109 +++++++++++++++++++++++++++ kernel/Makefile | 1 + kernel/cpu_pm.c | 200 +++++++++++++++++++++++++++++++++++++++++++++++++ kernel/power/Kconfig | 4 + 4 files changed, 314 insertions(+) create mode 100644 include/linux/cpu_pm.h create mode 100644 kernel/cpu_pm.c (limited to 'kernel') diff --git a/include/linux/cpu_pm.h b/include/linux/cpu_pm.h new file mode 100644 index 000000000000..455b233dd3b1 --- /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 eca595e2fd52..988cb3da7031 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 000000000000..4d1ff4acd04b --- /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 3744c594b19b..80a85971cf64 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 -- cgit v1.2.3 From 6f3eaec87b6b17bfa49cb3b5b8d07fa84be18512 Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Fri, 22 Jul 2011 14:57:09 -0700 Subject: cpu_pm: call notifiers during suspend Implements syscore_ops in cpu_pm to call the cpu and cpu cluster notifiers during suspend and resume, allowing drivers receiving the notifications to avoid implementing syscore_ops. Signed-off-by: Colin Cross Signed-off-by: Santosh Shilimkar Reviewed-by: Kevin Hilman Tested-and-Acked-by: Shawn Guo Tested-by: Vishwanath BS --- kernel/cpu_pm.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'kernel') diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c index 4d1ff4acd04b..249152e15308 100644 --- a/kernel/cpu_pm.c +++ b/kernel/cpu_pm.c @@ -20,6 +20,7 @@ #include #include #include +#include static DEFINE_RWLOCK(cpu_pm_notifier_lock); static RAW_NOTIFIER_HEAD(cpu_pm_notifier_chain); @@ -198,3 +199,35 @@ int cpu_cluster_pm_exit(void) return ret; } EXPORT_SYMBOL_GPL(cpu_cluster_pm_exit); + +#ifdef CONFIG_PM +static int cpu_pm_suspend(void) +{ + int ret; + + ret = cpu_pm_enter(); + if (ret) + return ret; + + ret = cpu_cluster_pm_enter(); + return ret; +} + +static void cpu_pm_resume(void) +{ + cpu_cluster_pm_exit(); + cpu_pm_exit(); +} + +static struct syscore_ops cpu_pm_syscore_ops = { + .suspend = cpu_pm_suspend, + .resume = cpu_pm_resume, +}; + +static int cpu_pm_init(void) +{ + register_syscore_ops(&cpu_pm_syscore_ops); + return 0; +} +core_initcall(cpu_pm_init); +#endif -- cgit v1.2.3