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Diffstat (limited to 'kernel/timer.c')
-rw-r--r--kernel/timer.c35
1 files changed, 24 insertions, 11 deletions
diff --git a/kernel/timer.c b/kernel/timer.c
index 8d185a1677cc..706fe4c53e82 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -95,6 +95,11 @@ static inline unsigned int tbase_get_deferrable(struct tvec_base *base)
return ((unsigned int)(unsigned long)base & TIMER_DEFERRABLE);
}
+static inline unsigned int tbase_get_irqsafe(struct tvec_base *base)
+{
+ return ((unsigned int)(unsigned long)base & TIMER_IRQSAFE);
+}
+
static inline struct tvec_base *tbase_get_base(struct tvec_base *base)
{
return ((struct tvec_base *)((unsigned long)base & ~TIMER_FLAG_MASK));
@@ -1002,14 +1007,14 @@ EXPORT_SYMBOL(try_to_del_timer_sync);
*
* Synchronization rules: Callers must prevent restarting of the timer,
* otherwise this function is meaningless. It must not be called from
- * interrupt contexts. The caller must not hold locks which would prevent
- * completion of the timer's handler. The timer's handler must not call
- * add_timer_on(). Upon exit the timer is not queued and the handler is
- * not running on any CPU.
+ * interrupt contexts unless the timer is an irqsafe one. The caller must
+ * not hold locks which would prevent completion of the timer's
+ * handler. The timer's handler must not call add_timer_on(). Upon exit the
+ * timer is not queued and the handler is not running on any CPU.
*
- * Note: You must not hold locks that are held in interrupt context
- * while calling this function. Even if the lock has nothing to do
- * with the timer in question. Here's why:
+ * Note: For !irqsafe timers, you must not hold locks that are held in
+ * interrupt context while calling this function. Even if the lock has
+ * nothing to do with the timer in question. Here's why:
*
* CPU0 CPU1
* ---- ----
@@ -1046,7 +1051,7 @@ int del_timer_sync(struct timer_list *timer)
* don't use it in hardirq context, because it
* could lead to deadlock.
*/
- WARN_ON(in_irq());
+ WARN_ON(in_irq() && !tbase_get_irqsafe(timer->base));
for (;;) {
int ret = try_to_del_timer_sync(timer);
if (ret >= 0)
@@ -1153,19 +1158,27 @@ static inline void __run_timers(struct tvec_base *base)
while (!list_empty(head)) {
void (*fn)(unsigned long);
unsigned long data;
+ bool irqsafe;
timer = list_first_entry(head, struct timer_list,entry);
fn = timer->function;
data = timer->data;
+ irqsafe = tbase_get_irqsafe(timer->base);
timer_stats_account_timer(timer);
base->running_timer = timer;
detach_expired_timer(timer, base);
- spin_unlock_irq(&base->lock);
- call_timer_fn(timer, fn, data);
- spin_lock_irq(&base->lock);
+ if (irqsafe) {
+ spin_unlock(&base->lock);
+ call_timer_fn(timer, fn, data);
+ spin_lock(&base->lock);
+ } else {
+ spin_unlock_irq(&base->lock);
+ call_timer_fn(timer, fn, data);
+ spin_lock_irq(&base->lock);
+ }
}
}
base->running_timer = NULL;