From mboxrd@z Thu Jan 1 00:00:00 1970 From: lina.iyer@linaro.org (Lina Iyer) Date: Fri, 26 Aug 2016 14:17:49 -0600 Subject: [PATCH v5 07/16] kernel/cpu_pm: Add runtime PM support for CPUs In-Reply-To: <1472242678-33700-1-git-send-email-lina.iyer@linaro.org> References: <1472242678-33700-1-git-send-email-lina.iyer@linaro.org> Message-ID: <1472242678-33700-8-git-send-email-lina.iyer@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 Cc: Rafael J. Wysocki Signed-off-by: Lina Iyer --- 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 +#include #include #include #include +#include #include #include @@ -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