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authorThomas Gleixner <tglx@linutronix.de>2014-02-03 14:34:31 -0800
committerThomas Gleixner <tglx@linutronix.de>2014-02-07 15:34:28 +0100
commit627ee7947e2e83ba565c31c5c9373d6e364b1ecd (patch)
tree30fc40a08542f0411e28ba9becc00e07f7ec3b44 /kernel/time/clockevents.c
parente8b175946c16d7001b22620f52d78ab497efc9d0 (diff)
downloadop-kernel-dev-627ee7947e2e83ba565c31c5c9373d6e364b1ecd.zip
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clockevents: Serialize calls to clockevents_update_freq() in the core
We can identify the broadcast device in the core and serialize all callers including interrupts on a different CPU against the update. Also, disabling interrupts is moved into the core allowing callers to leave interrutps enabled when calling clockevents_update_freq(). Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Soeren Brinkmann <soren.brinkmann@xilinx.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Michal Simek <michal.simek@xilinx.com> Link: http://lkml.kernel.org/r/1391466877-28908-2-git-send-email-soren.brinkmann@xilinx.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time/clockevents.c')
-rw-r--r--kernel/time/clockevents.c29
1 files changed, 22 insertions, 7 deletions
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 086ad60..641d910 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -439,6 +439,16 @@ void clockevents_config_and_register(struct clock_event_device *dev,
}
EXPORT_SYMBOL_GPL(clockevents_config_and_register);
+int __clockevents_update_freq(struct clock_event_device *dev, u32 freq)
+{
+ clockevents_config(dev, freq);
+
+ if (dev->mode != CLOCK_EVT_MODE_ONESHOT)
+ return 0;
+
+ return clockevents_program_event(dev, dev->next_event, false);
+}
+
/**
* clockevents_update_freq - Update frequency and reprogram a clock event device.
* @dev: device to modify
@@ -446,17 +456,22 @@ EXPORT_SYMBOL_GPL(clockevents_config_and_register);
*
* Reconfigure and reprogram a clock event device in oneshot
* mode. Must be called on the cpu for which the device delivers per
- * cpu timer events with interrupts disabled! Returns 0 on success,
- * -ETIME when the event is in the past.
+ * cpu timer events. If called for the broadcast device the core takes
+ * care of serialization.
+ *
+ * Returns 0 on success, -ETIME when the event is in the past.
*/
int clockevents_update_freq(struct clock_event_device *dev, u32 freq)
{
- clockevents_config(dev, freq);
-
- if (dev->mode != CLOCK_EVT_MODE_ONESHOT)
- return 0;
+ unsigned long flags;
+ int ret;
- return clockevents_program_event(dev, dev->next_event, false);
+ local_irq_save(flags);
+ ret = tick_broadcast_update_freq(dev, freq);
+ if (ret == -ENODEV)
+ ret = __clockevents_update_freq(dev, freq);
+ local_irq_restore(flags);
+ return ret;
}
/*
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