[RFC PATCH 2/5] clockevents: Add generic timer broadcast receiver

From: Mark Rutland
Date: Tue Dec 18 2012 - 07:07:37 EST

Currently the broadcast mechanism used for timers is abstracted by a
function pointer on struct clock_event_device. As the fundamental
mechanism for broadcast is architecture-specific, this ties each
clock_event_device driver to a single architecture, even where the
driver is otherwise generic.

This patch adds a standard path for the receipt of timer broadcasts, so
drivers and/or architecture backends need not manage redundant lists of
timers for the purpose of routing broadcast timer ticks.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
include/linux/clockchips.h | 4 ++++
kernel/time/tick-broadcast.c | 15 +++++++++++++++
2 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index 8a7096f..e1089aa 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -161,6 +161,10 @@ clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
extern void clockevents_suspend(void);
extern void clockevents_resume(void);

+extern int tick_receive_broadcast(void);
extern void clockevents_notify(unsigned long reason, void *arg);
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index f113755..c2dd022 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -125,6 +125,21 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
return ret;

+int tick_receive_broadcast(void)
+ struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
+ struct clock_event_device *evt = td->evtdev;
+ if (!evt)
+ return -ENODEV;
+ if (!evt->event_handler)
+ return -EINVAL;
+ evt->event_handler(evt);
+ return 0;
* Broadcast the event to the cpus, which are set in the mask (mangled).

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