[PATCHv2 1/4] clockevents: Add generic timer broadcast receiver

From: Mark Rutland
Date: Wed Jan 09 2013 - 09:46:41 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>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
Tested-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
---
include/linux/clockchips.h | 9 +++++++++
kernel/time/tick-broadcast.c | 12 ++++++++++++
2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index 8a7096f..6537114 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -161,6 +161,15 @@ clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
extern void clockevents_suspend(void);
extern void clockevents_resume(void);

+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+extern int tick_receive_broadcast(void);
+#else
+static inline int tick_receive_broadcast(void)
+{
+ return 0;
+}
+#endif
+
#ifdef CONFIG_GENERIC_CLOCKEVENTS
extern void clockevents_notify(unsigned long reason, void *arg);
#else
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index f113755..5079bb7 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -125,6 +125,18 @@ 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;
+
+ evt->event_handler(evt);
+ return 0;
+}
+
/*
* Broadcast the event to the cpus, which are set in the mask (mangled).
*/
--
1.7.0.4


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