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| author | Thomas Gleixner <tglx@linutronix.de> | 2013-04-25 20:31:50 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2013-05-16 11:09:18 +0200 |
| commit | 03e13cf5ee60584fe0c831682c67212effb7fca4 (patch) | |
| tree | b40a9a0a88a675e4511ad6b6c0bf072b6a1ef9f4 /kernel/time/tick-common.c | |
| parent | 45cb8e01b2ecef1c2afb18333e95793fa1a90281 (diff) | |
| download | linux-03e13cf5ee60584fe0c831682c67212effb7fca4.tar.bz2 | |
clockevents: Implement unbind functionality
Provide a sysfs interface to allow unbinding of clockevent
devices. The device is unbound if it is unused or if there is a
replacement device available. Unbinding of broadcast devices is not
supported as we don't want to foster that nonsense. If no replacement
device is available the unbind returns -EBUSY. Unbind is available
from the kernel and through sysfs, which is necessary to drop the
module refcount.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130425143436.499216659@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time/tick-common.c')
| -rw-r--r-- | kernel/time/tick-common.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index c34021650348..5edfb4806032 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -205,6 +205,17 @@ static void tick_setup_device(struct tick_device *td, tick_setup_oneshot(newdev, handler, next_event); } +void tick_install_replacement(struct clock_event_device *newdev) +{ + struct tick_device *td = &__get_cpu_var(tick_cpu_device); + int cpu = smp_processor_id(); + + clockevents_exchange_device(td->evtdev, newdev); + tick_setup_device(td, newdev, cpu, cpumask_of(cpu)); + if (newdev->features & CLOCK_EVT_FEAT_ONESHOT) + tick_oneshot_notify(); +} + static bool tick_check_percpu(struct clock_event_device *curdev, struct clock_event_device *newdev, int cpu) { @@ -237,6 +248,19 @@ static bool tick_check_preferred(struct clock_event_device *curdev, } /* + * Check whether the new device is a better fit than curdev. curdev + * can be NULL ! + */ +bool tick_check_replacement(struct clock_event_device *curdev, + struct clock_event_device *newdev) +{ + if (tick_check_percpu(curdev, newdev, smp_processor_id())) + return false; + + return tick_check_preferred(curdev, newdev); +} + +/* * Check, if the new registered device should be used. Called with * clockevents_lock held and interrupts disabled. */ |