From b60e6a0eb0273132cbb60a9806abf5f47a4aee1c Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Thu, 21 Mar 2013 12:21:31 +0000 Subject: cpuidle : handle clockevent notify from the cpuidle framework When a cpu enters a deep idle state, the local timers are stopped and the time framework falls back to the timer device used as a broadcast timer. The different cpuidle drivers are calling clockevents_notify ENTER/EXIT when the idle state stops the local timer. Add a new flag CPUIDLE_FLAG_TIMER_STOP which can be set by the cpuidle drivers. If the flag is set, the cpuidle core code takes care of the notification on behalf of the driver to avoid pointless code duplication. Signed-off-by: Daniel Lezcano Reviewed-by: Thomas Gleixner Acked-by: Santosh Shilimkar Signed-off-by: Rafael J. Wysocki --- include/linux/cpuidle.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 480c14dc1dd..a837b332df6 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -57,6 +57,7 @@ struct cpuidle_state { /* Idle State Flags */ #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */ #define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */ +#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */ #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) -- cgit v1.2.3-70-g09d2 From 4dbad816febb6cb7340e36af4f5c0dc86e55a2ca Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Wed, 27 Mar 2013 10:22:09 +0000 Subject: timer: move enum definition out of ifdef section The next patch will setup automatically the broadcast timer for the different cpuidle driver when one idle state stops its timer. This will be part of the generic code. But some ARM boards, like s3c64xx, uses cpuidle but without the CONFIG_GENERIC_CLOCKEVENTS_BUILD set. Hence the cpuidle framework will be compiled with the code supposed to be generic, that is with clockevents_notify and the different enum. Also the function clockevents_notify is a noop macro, this is fine except the usual code is: int cpu = smp_processor_id(); clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &cpu); and that raises a warning for the variable cpu which is not used. Move the clock_event_nofitiers enum definition out of the CONFIG_GENERIC_CLOCKEVENTS_BUILD section to prevent a compilation error when these are used in the code. Change the clockevents_notify macro to a static inline noop function to prevent a compilation warning. Signed-off-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki --- include/linux/clockchips.h | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) (limited to 'include') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 66346521cb6..f9fd9375833 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -8,6 +8,20 @@ #ifndef _LINUX_CLOCKCHIPS_H #define _LINUX_CLOCKCHIPS_H +/* Clock event notification values */ +enum clock_event_nofitiers { + CLOCK_EVT_NOTIFY_ADD, + CLOCK_EVT_NOTIFY_BROADCAST_ON, + CLOCK_EVT_NOTIFY_BROADCAST_OFF, + CLOCK_EVT_NOTIFY_BROADCAST_FORCE, + CLOCK_EVT_NOTIFY_BROADCAST_ENTER, + CLOCK_EVT_NOTIFY_BROADCAST_EXIT, + CLOCK_EVT_NOTIFY_SUSPEND, + CLOCK_EVT_NOTIFY_RESUME, + CLOCK_EVT_NOTIFY_CPU_DYING, + CLOCK_EVT_NOTIFY_CPU_DEAD, +}; + #ifdef CONFIG_GENERIC_CLOCKEVENTS_BUILD #include @@ -26,20 +40,6 @@ enum clock_event_mode { CLOCK_EVT_MODE_RESUME, }; -/* Clock event notification values */ -enum clock_event_nofitiers { - CLOCK_EVT_NOTIFY_ADD, - CLOCK_EVT_NOTIFY_BROADCAST_ON, - CLOCK_EVT_NOTIFY_BROADCAST_OFF, - CLOCK_EVT_NOTIFY_BROADCAST_FORCE, - CLOCK_EVT_NOTIFY_BROADCAST_ENTER, - CLOCK_EVT_NOTIFY_BROADCAST_EXIT, - CLOCK_EVT_NOTIFY_SUSPEND, - CLOCK_EVT_NOTIFY_RESUME, - CLOCK_EVT_NOTIFY_CPU_DYING, - CLOCK_EVT_NOTIFY_CPU_DEAD, -}; - /* * Clock event features */ @@ -173,7 +173,7 @@ extern int tick_receive_broadcast(void); #ifdef CONFIG_GENERIC_CLOCKEVENTS extern void clockevents_notify(unsigned long reason, void *arg); #else -# define clockevents_notify(reason, arg) do { } while (0) +static inline void clockevents_notify(unsigned long reason, void *arg) {} #endif #else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */ @@ -181,7 +181,7 @@ extern void clockevents_notify(unsigned long reason, void *arg); static inline void clockevents_suspend(void) {} static inline void clockevents_resume(void) {} -#define clockevents_notify(reason, arg) do { } while (0) +static inline void clockevents_notify(unsigned long reason, void *arg) {} #endif -- cgit v1.2.3-70-g09d2 From a06df062a189a8d5588babb8bf0bb78672497798 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Wed, 27 Mar 2013 10:22:10 +0000 Subject: cpuidle: initialize the broadcast timer framework The commit 89878baa73f0f1c679355006bd8632e5d78f96c2 introduced the CPUIDLE_FLAG_TIMER_STOP flag where we specify a specific idle state stops the local timer. Now use this flag to check at init time if one state will need the broadcast timer and, in this case, setup the broadcast timer framework. That prevents multiple code duplication in the drivers. Signed-off-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki --- drivers/cpuidle/driver.c | 31 +++++++++++++++++++++++++++++-- include/linux/cpuidle.h | 2 ++ 2 files changed, 31 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 422c7b69ba7..8dfaaae9444 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -11,6 +11,8 @@ #include #include #include +#include +#include #include "cpuidle.h" @@ -19,9 +21,28 @@ DEFINE_SPINLOCK(cpuidle_driver_lock); static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu); static struct cpuidle_driver * __cpuidle_get_cpu_driver(int cpu); -static void __cpuidle_driver_init(struct cpuidle_driver *drv) +static void cpuidle_setup_broadcast_timer(void *arg) { + int cpu = smp_processor_id(); + clockevents_notify((long)(arg), &cpu); +} + +static void __cpuidle_driver_init(struct cpuidle_driver *drv, int cpu) +{ + int i; + drv->refcnt = 0; + + for (i = drv->state_count - 1; i >= 0 ; i--) { + + if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP)) + continue; + + drv->bctimer = 1; + on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer, + (void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1); + break; + } } static int __cpuidle_register_driver(struct cpuidle_driver *drv, int cpu) @@ -35,7 +56,7 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv, int cpu) if (__cpuidle_get_cpu_driver(cpu)) return -EBUSY; - __cpuidle_driver_init(drv); + __cpuidle_driver_init(drv, cpu); __cpuidle_set_cpu_driver(drv, cpu); @@ -49,6 +70,12 @@ static void __cpuidle_unregister_driver(struct cpuidle_driver *drv, int cpu) if (!WARN_ON(drv->refcnt > 0)) __cpuidle_set_cpu_driver(NULL, cpu); + + if (drv->bctimer) { + drv->bctimer = 0; + on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer, + (void *)CLOCK_EVT_NOTIFY_BROADCAST_OFF, 1); + } } #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index a837b332df6..fc3e5808b7f 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -107,6 +107,8 @@ struct cpuidle_driver { /* set to 1 to use the core cpuidle time keeping (for all states). */ unsigned int en_core_tk_irqen:1; + /* used by the cpuidle framework to setup the broadcast timer */ + unsigned int bctimer:1; /* states array must be ordered in decreasing power consumption */ struct cpuidle_state states[CPUIDLE_STATE_MAX]; int state_count; -- cgit v1.2.3-70-g09d2