[PATCH v5 07/16] kernel/cpu_pm: Add runtime PM support for CPUs
From: Lina Iyer <hidden>
Date: 2016-08-26 20:17:49
Also in:
linux-arm-msm, linux-pm
Subsystem:
the rest · Maintainer:
Linus Torvalds
Notify runtime PM when the CPU is going to be powered off in the idle state. This allows for runtime PM suspend/resume of the CPU as well as its PM domain. Cc: Kevin Hilman <khilman@kernel.org> Cc: Rafael J. Wysocki <redacted> Signed-off-by: Lina Iyer <redacted> --- kernel/cpu_pm.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+)
diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c
index 009cc9a..657ce06 100644
--- a/kernel/cpu_pm.c
+++ b/kernel/cpu_pm.c@@ -16,9 +16,11 @@ */ #include <linux/kernel.h> +#include <linux/cpu.h> #include <linux/cpu_pm.h> #include <linux/module.h> #include <linux/notifier.h> +#include <linux/pm_runtime.h> #include <linux/spinlock.h> #include <linux/syscore_ops.h>
@@ -99,6 +101,7 @@ int cpu_pm_enter(void) { int nr_calls; int ret = 0; + struct device *dev = get_cpu_device(smp_processor_id()); read_lock(&cpu_pm_notifier_lock); ret = cpu_pm_notify(CPU_PM_ENTER, -1, &nr_calls);
@@ -110,6 +113,10 @@ int cpu_pm_enter(void) cpu_pm_notify(CPU_PM_ENTER_FAILED, nr_calls - 1, NULL); read_unlock(&cpu_pm_notifier_lock); + /* Notify Runtime PM that we are suspending the CPU */ + if (!ret && dev) + RCU_NONIDLE(pm_runtime_put_sync_suspend(dev)); + return ret; } EXPORT_SYMBOL_GPL(cpu_pm_enter);
@@ -129,6 +136,11 @@ EXPORT_SYMBOL_GPL(cpu_pm_enter); int cpu_pm_exit(void) { int ret; + struct device *dev = get_cpu_device(smp_processor_id()); + + /* Notify Runtime PM that we are resuming the CPU */ + if (dev) + RCU_NONIDLE(pm_runtime_get_sync(dev)); read_lock(&cpu_pm_notifier_lock); ret = cpu_pm_notify(CPU_PM_EXIT, -1, NULL);
@@ -200,6 +212,39 @@ int cpu_cluster_pm_exit(void) } EXPORT_SYMBOL_GPL(cpu_cluster_pm_exit); +#ifdef CONFIG_HOTPLUG_CPU +static int cpu_pm_cpu_hotplug(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = get_cpu_device(smp_processor_id()); + + if (!dev) + return NOTIFY_OK; + + /* Execute CPU runtime PM on that CPU */ + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_DYING: + pm_runtime_put_sync_suspend(dev); + break; + case CPU_STARTING: + pm_runtime_get_sync(dev); + break; + default: + break; + } + + return NOTIFY_OK; +} + +static int __init cpu_pm_hotplug_init(void) +{ + /* Register for hotplug notifications for runtime PM */ + hotcpu_notifier(cpu_pm_cpu_hotplug, 0); + return 0; +} +device_initcall(cpu_pm_hotplug_init); +#endif + #ifdef CONFIG_PM static int cpu_pm_suspend(void) {
--
2.7.4