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clockevents: Split out selection logic

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Split out the clockevent device selection logic. Preparatory patch to
allow unbinding active clockevent devices.

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/20130425143436.431796247@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2013-04-25 20:31:50 +00:00
parent 501f867064
commit 45cb8e01b2
2 changed files with 56 additions and 38 deletions
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25
kernel/time/tick-broadcast.c
View File

@ -65,19 +65,34 @@ static void tick_broadcast_start_periodic(struct clock_event_device *bc)
/*
* Check, if the device can be utilized as broadcast device:
*/
static bool tick_check_broadcast_device(struct clock_event_device *curdev,
struct clock_event_device *newdev)
{
if ((newdev->features & CLOCK_EVT_FEAT_DUMMY) ||
(newdev->features & CLOCK_EVT_FEAT_C3STOP))
return false;
if (tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT &&
!(newdev->features & CLOCK_EVT_FEAT_ONESHOT))
return false;
return !curdev || newdev->rating > curdev->rating;
}
/*
* Conditionally install/replace broadcast device
*/
void tick_install_broadcast_device(struct clock_event_device *dev)
{
struct clock_event_device *cur = tick_broadcast_device.evtdev;
if ((dev->features & CLOCK_EVT_FEAT_DUMMY) ||
(tick_broadcast_device.evtdev &&
tick_broadcast_device.evtdev->rating >= dev->rating) ||
(dev->features & CLOCK_EVT_FEAT_C3STOP))
if (!tick_check_broadcast_device(cur, dev))
return;
if (!try_module_get(dev->owner))
return;
clockevents_exchange_device(tick_broadcast_device.evtdev, dev);
clockevents_exchange_device(cur, dev);
if (cur)
cur->event_handler = clockevents_handle_noop;
tick_broadcast_device.evtdev = dev;

69
kernel/time/tick-common.c
View File

@ -205,6 +205,37 @@ static void tick_setup_device(struct tick_device *td,
tick_setup_oneshot(newdev, handler, next_event);
}
static bool tick_check_percpu(struct clock_event_device *curdev,
struct clock_event_device *newdev, int cpu)
{
if (!cpumask_test_cpu(cpu, newdev->cpumask))
return false;
if (cpumask_equal(newdev->cpumask, cpumask_of(cpu)))
return true;
/* Check if irq affinity can be set */
if (newdev->irq >= 0 && !irq_can_set_affinity(newdev->irq))
return false;
/* Prefer an existing cpu local device */
if (curdev && cpumask_equal(curdev->cpumask, cpumask_of(cpu)))
return false;
return true;
}
static bool tick_check_preferred(struct clock_event_device *curdev,
struct clock_event_device *newdev)
{
/* Prefer oneshot capable device */
if (!(newdev->features & CLOCK_EVT_FEAT_ONESHOT)) {
if (curdev && (curdev->features & CLOCK_EVT_FEAT_ONESHOT))
return false;
if (tick_oneshot_mode_active())
return false;
}
/* Use the higher rated one */
return !curdev || newdev->rating > curdev->rating;
}
/*
* Check, if the new registered device should be used. Called with
* clockevents_lock held and interrupts disabled.
@ -223,40 +254,12 @@ void tick_check_new_device(struct clock_event_device *newdev)
curdev = td->evtdev;
/* cpu local device ? */
if (!cpumask_equal(newdev->cpumask, cpumask_of(cpu))) {
if (!tick_check_percpu(curdev, newdev, cpu))
goto out_bc;
/*
* If the cpu affinity of the device interrupt can not
* be set, ignore it.
*/
if (!irq_can_set_affinity(newdev->irq))
goto out_bc;
/*
* If we have a cpu local device already, do not replace it
* by a non cpu local device
*/
if (curdev && cpumask_equal(curdev->cpumask, cpumask_of(cpu)))
goto out_bc;
}
/*
* If we have an active device, then check the rating and the oneshot
* feature.
*/
if (curdev) {
/*
* Prefer one shot capable devices !
*/
if ((curdev->features & CLOCK_EVT_FEAT_ONESHOT) &&
!(newdev->features & CLOCK_EVT_FEAT_ONESHOT))
goto out_bc;
/*
* Check the rating
*/
if (curdev->rating >= newdev->rating)
goto out_bc;
}
/* Preference decision */
if (!tick_check_preferred(curdev, newdev))
goto out_bc;
if (!try_module_get(newdev->owner))
return;