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. We do not call into runtime PM for ARM WFI to keep the default state simple and faster. Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx> --- Changes since RFC v1 - - runtime PM initialization is now done as part of this file - hotplug and its runtime PM invocation is done here drivers/cpuidle/cpuidle-arm.c | 48 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c index 545069d..bf7a80c 100644 --- a/drivers/cpuidle/cpuidle-arm.c +++ b/drivers/cpuidle/cpuidle-arm.c @@ -11,12 +11,14 @@ #define pr_fmt(fmt) "CPUidle arm: " fmt +#include <linux/cpu.h> #include <linux/cpuidle.h> #include <linux/cpumask.h> #include <linux/cpu_pm.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/pm_runtime.h> #include <linux/slab.h> #include <asm/cpuidle.h> @@ -37,6 +39,7 @@ static int arm_enter_idle_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, int idx) { int ret; + struct device *cpu_dev = get_cpu_device(dev->cpu); if (!idx) { cpu_do_idle(); @@ -45,6 +48,8 @@ static int arm_enter_idle_state(struct cpuidle_device *dev, ret = cpu_pm_enter(); if (!ret) { + RCU_NONIDLE(pm_runtime_put_sync_suspend(cpu_dev)); + /* * Pass idle state index to cpu_suspend which in turn will * call the CPU ops suspend protocol with idle index as a @@ -52,6 +57,7 @@ static int arm_enter_idle_state(struct cpuidle_device *dev, */ arm_cpuidle_suspend(idx); + RCU_NONIDLE(pm_runtime_get_sync(cpu_dev)); cpu_pm_exit(); } @@ -84,6 +90,30 @@ static const struct of_device_id arm_idle_state_match[] __initconst = { { }, }; +#ifdef CONFIG_HOTPLUG_CPU +static int cpu_hotplug(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *cpu_dev = get_cpu_device(smp_processor_id()); + + /* Execute CPU runtime PM on that CPU */ + switch (action) { + case CPU_DYING: + case CPU_DYING_FROZEN: + RCU_NONIDLE(pm_runtime_put_sync_suspend(cpu_dev)); + break; + case CPU_STARTING: + case CPU_STARTING_FROZEN: + RCU_NONIDLE(pm_runtime_get_sync(cpu_dev)); + break; + default: + break; + } + + return NOTIFY_OK; +} +#endif + /* * arm_idle_init * @@ -96,6 +126,7 @@ static int __init arm_idle_init(void) int cpu, ret; struct cpuidle_driver *drv = &arm_idle_driver; struct cpuidle_device *dev; + struct device *cpu_dev; /* * Initialize idle states data, starting at index 1. @@ -118,6 +149,16 @@ static int __init arm_idle_init(void) * idle states suspend back-end specific data */ for_each_possible_cpu(cpu) { + + /* Initialize Runtime PM for the CPU */ + cpu_dev = get_cpu_device(cpu); + pm_runtime_irq_safe(cpu_dev); + pm_runtime_enable(cpu_dev); + if (cpu_online(cpu)) { + pm_runtime_get_noresume(cpu_dev); + pm_runtime_set_active(cpu_dev); + } + ret = arm_cpuidle_init(cpu); /* @@ -148,10 +189,17 @@ static int __init arm_idle_init(void) } } +#ifdef CONFIG_HOTPLUG_CPU + /* Register for hotplug notifications for runtime PM */ + hotcpu_notifier(cpu_hotplug, 0); +#endif + return 0; out_fail: while (--cpu >= 0) { dev = per_cpu(cpuidle_devices, cpu); + cpu_dev = get_cpu_device(cpu); + __pm_runtime_disable(cpu_dev, false); cpuidle_unregister_device(dev); kfree(dev); } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html