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| author |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2011-08-23 15:29:43 +0200 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2011-09-08 11:10:56 +0200 |
| commit | 65516f8a7c2028381f0dae4c16ddb621c96158cc (patch) | |
| tree | 1f6192832c77e25499331b074398e165c1220197 | |
| parent | clockevents: Make minimum delay adjustments configurable (diff) | |
| download | linux-dev-65516f8a7c2028381f0dae4c16ddb621c96158cc.tar.xz linux-dev-65516f8a7c2028381f0dae4c16ddb621c96158cc.zip | |
clockevents: Add direct ktime programming function
There is at least one architecture (s390) with a sane clockevent device
that can be programmed with the equivalent of a ktime. No need to create
a delta against the current time, the ktime can be used directly.
A new clock device function 'set_next_ktime' is introduced that is called
with the unmodified ktime for the timer if the clock event device has the
CLOCK_EVT_FEAT_KTIME bit set.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: john stultz <johnstul@us.ibm.com>
Link: http://lkml.kernel.org/r/20110823133142.815350967@de.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/clockchips.h | 10 | ||||
| -rw-r--r-- | kernel/time/clockevents.c | 4 |
2 files changed, 11 insertions, 3 deletions
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 39bb050bdbb2..81e803e90aa4 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -45,20 +45,22 @@ enum clock_event_nofitiers { */ #define CLOCK_EVT_FEAT_PERIODIC 0x000001 #define CLOCK_EVT_FEAT_ONESHOT 0x000002 +#define CLOCK_EVT_FEAT_KTIME 0x000004 /* * x86(64) specific misfeatures: * * - Clockevent source stops in C3 State and needs broadcast support. * - Local APIC timer is used as a dummy device. */ -#define CLOCK_EVT_FEAT_C3STOP 0x000004 -#define CLOCK_EVT_FEAT_DUMMY 0x000008 +#define CLOCK_EVT_FEAT_C3STOP 0x000008 +#define CLOCK_EVT_FEAT_DUMMY 0x000010 /** * struct clock_event_device - clock event device descriptor * @event_handler: Assigned by the framework to be called by the low * level handler of the event source - * @set_next_event: set next event function + * @set_next_event: set next event function using a clocksource delta + * @set_next_ktime: set next event function using a direct ktime value * @next_event: local storage for the next event in oneshot mode * @max_delta_ns: maximum delta value in ns * @min_delta_ns: minimum delta value in ns @@ -81,6 +83,8 @@ struct clock_event_device { void (*event_handler)(struct clock_event_device *); int (*set_next_event)(unsigned long evt, struct clock_event_device *); + int (*set_next_ktime)(ktime_t expires, + struct clock_event_device *); ktime_t next_event; u64 max_delta_ns; u64 min_delta_ns; diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 713ef94eceef..1ecd6ba36d6c 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -216,6 +216,10 @@ int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN) return 0; + /* Shortcut for clockevent devices that can deal with ktime. */ + if (dev->features & CLOCK_EVT_FEAT_KTIME) + return dev->set_next_ktime(expires, dev); + delta = ktime_to_ns(ktime_sub(expires, ktime_get())); if (delta <= 0) return force ? clockevents_program_min_delta(dev) : -ETIME; |