diff options
Diffstat (limited to 'kernel/time/tick-broadcast.c')
| -rw-r--r-- | kernel/time/tick-broadcast.c | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 115e0bf01276..bda3d2391a60 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -165,23 +165,31 @@ static bool tick_set_oneshot_wakeup_device(struct clock_event_device *newdev, */ void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { - struct clock_event_device *cur = tick_broadcast_device.evtdev; + struct clock_event_device *cur; - if (tick_set_oneshot_wakeup_device(dev, cpu)) - return; + scoped_guard(raw_spinlock_irqsave, &tick_broadcast_lock) { - if (!tick_check_broadcast_device(cur, dev)) - return; + if (tick_set_oneshot_wakeup_device(dev, cpu)) + return; - if (!try_module_get(dev->owner)) - return; + cur = tick_broadcast_device.evtdev; + if (!tick_check_broadcast_device(cur, dev)) + return; - clockevents_exchange_device(cur, dev); + if (!try_module_get(dev->owner)) + return; + + __clockevents_exchange_device(cur, dev); + if (cur) + cur->event_handler = clockevents_handle_noop; + WRITE_ONCE(tick_broadcast_device.evtdev, dev); + if (!cpumask_empty(tick_broadcast_mask)) + tick_broadcast_start_periodic(dev); + } + + /* Module release must be outside of the lock */ if (cur) - cur->event_handler = clockevents_handle_noop; - tick_broadcast_device.evtdev = dev; - if (!cpumask_empty(tick_broadcast_mask)) - tick_broadcast_start_periodic(dev); + module_put(cur->owner); if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT)) return; @@ -1218,7 +1226,7 @@ int tick_broadcast_oneshot_active(void) */ bool tick_broadcast_oneshot_available(void) { - struct clock_event_device *bc = tick_broadcast_device.evtdev; + struct clock_event_device *bc = READ_ONCE(tick_broadcast_device.evtdev); return bc ? bc->features & CLOCK_EVT_FEAT_ONESHOT : false; } @@ -1226,7 +1234,7 @@ bool tick_broadcast_oneshot_available(void) #else int __tick_broadcast_oneshot_control(enum tick_broadcast_state state) { - struct clock_event_device *bc = tick_broadcast_device.evtdev; + struct clock_event_device *bc = READ_ONCE(tick_broadcast_device.evtdev); if (!bc || (bc->features & CLOCK_EVT_FEAT_HRTIMER)) return -EBUSY; |