From 46bcfad7a819bd17ac4e831b04405152d59784ab Mon Sep 17 00:00:00 2001 From: Deepthi Dharwar Date: Fri, 28 Oct 2011 16:20:42 +0530 Subject: cpuidle: Single/Global registration of idle states This patch makes the cpuidle_states structure global (single copy) instead of per-cpu. The statistics needed on per-cpu basis by the governor are kept per-cpu. This simplifies the cpuidle subsystem as state registration is done by single cpu only. Having single copy of cpuidle_states saves memory. Rare case of asymmetric C-states can be handled within the cpuidle driver and architectures such as POWER do not have asymmetric C-states. Having single/global registration of all the idle states, dynamic C-state transitions on x86 are handled by the boot cpu. Here, the boot cpu would disable all the devices, re-populate the states and later enable all the devices, irrespective of the cpu that would receive the notification first. Reference: https://lkml.org/lkml/2011/4/25/83 Signed-off-by: Deepthi Dharwar Signed-off-by: Trinabh Gupta Tested-by: Jean Pihet Reviewed-by: Kevin Hilman Acked-by: Arjan van de Ven Acked-by: Kevin Hilman Signed-off-by: Len Brown --- drivers/cpuidle/cpuidle.c | 45 ++++++++++++--------------------------------- 1 file changed, 12 insertions(+), 33 deletions(-) (limited to 'drivers/cpuidle/cpuidle.c') diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 7127e92..7a57b11 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -61,6 +61,7 @@ static int __cpuidle_register_device(struct cpuidle_device *dev); int cpuidle_idle_call(void) { struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); + struct cpuidle_driver *drv = cpuidle_get_driver(); struct cpuidle_state *target_state; int next_state, entered_state; @@ -84,18 +85,18 @@ int cpuidle_idle_call(void) #endif /* ask the governor for the next state */ - next_state = cpuidle_curr_governor->select(dev); + next_state = cpuidle_curr_governor->select(drv, dev); if (need_resched()) { local_irq_enable(); return 0; } - target_state = &dev->states[next_state]; + target_state = &drv->states[next_state]; trace_power_start(POWER_CSTATE, next_state, dev->cpu); trace_cpu_idle(next_state, dev->cpu); - entered_state = target_state->enter(dev, next_state); + entered_state = target_state->enter(dev, drv, next_state); trace_power_end(dev->cpu); trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu); @@ -163,7 +164,8 @@ void cpuidle_resume_and_unlock(void) EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); #ifdef CONFIG_ARCH_HAS_CPU_RELAX -static int poll_idle(struct cpuidle_device *dev, int index) +static int poll_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { ktime_t t1, t2; s64 diff; @@ -183,12 +185,9 @@ static int poll_idle(struct cpuidle_device *dev, int index) return index; } -static void poll_idle_init(struct cpuidle_device *dev) +static void poll_idle_init(struct cpuidle_driver *drv) { - struct cpuidle_state *state = &dev->states[0]; - struct cpuidle_state_usage *state_usage = &dev->states_usage[0]; - - cpuidle_set_statedata(state_usage, NULL); + struct cpuidle_state *state = &drv->states[0]; snprintf(state->name, CPUIDLE_NAME_LEN, "POLL"); snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE"); @@ -199,7 +198,7 @@ static void poll_idle_init(struct cpuidle_device *dev) state->enter = poll_idle; } #else -static void poll_idle_init(struct cpuidle_device *dev) {} +static void poll_idle_init(struct cpuidle_driver *drv) {} #endif /* CONFIG_ARCH_HAS_CPU_RELAX */ /** @@ -226,13 +225,13 @@ int cpuidle_enable_device(struct cpuidle_device *dev) return ret; } - poll_idle_init(dev); + poll_idle_init(cpuidle_get_driver()); if ((ret = cpuidle_add_state_sysfs(dev))) return ret; if (cpuidle_curr_governor->enable && - (ret = cpuidle_curr_governor->enable(dev))) + (ret = cpuidle_curr_governor->enable(cpuidle_get_driver(), dev))) goto fail_sysfs; for (i = 0; i < dev->state_count; i++) { @@ -273,7 +272,7 @@ void cpuidle_disable_device(struct cpuidle_device *dev) dev->enabled = 0; if (cpuidle_curr_governor->disable) - cpuidle_curr_governor->disable(dev); + cpuidle_curr_governor->disable(cpuidle_get_driver(), dev); cpuidle_remove_state_sysfs(dev); enabled_devices--; @@ -301,26 +300,6 @@ static int __cpuidle_register_device(struct cpuidle_device *dev) init_completion(&dev->kobj_unregister); - /* - * cpuidle driver should set the dev->power_specified bit - * before registering the device if the driver provides - * power_usage numbers. - * - * For those devices whose ->power_specified is not set, - * we fill in power_usage with decreasing values as the - * cpuidle code has an implicit assumption that state Cn - * uses less power than C(n-1). - * - * With CONFIG_ARCH_HAS_CPU_RELAX, C0 is already assigned - * an power value of -1. So we use -2, -3, etc, for other - * c-states. - */ - if (!dev->power_specified) { - int i; - for (i = CPUIDLE_DRIVER_STATE_START; i < dev->state_count; i++) - dev->states[i].power_usage = -1 - i; - } - per_cpu(cpuidle_devices, dev->cpu) = dev; list_add(&dev->device_list, &cpuidle_detected_devices); if ((ret = cpuidle_add_sysfs(sys_dev))) { -- cgit v1.1