[S390] zcrypt: Do not simultaneously schedule hrtimer
Protect the hrtimer ap_poll_timer from being scheduled at the same
time from several processes.
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 21077f4..20836ef 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -102,6 +102,7 @@
static DECLARE_WAIT_QUEUE_HEAD(ap_poll_wait);
static struct task_struct *ap_poll_kthread = NULL;
static DEFINE_MUTEX(ap_poll_thread_mutex);
+static DEFINE_SPINLOCK(ap_poll_timer_lock);
static void *ap_interrupt_indicator;
static struct hrtimer ap_poll_timer;
/* In LPAR poll with 4kHz frequency. Poll every 250000 nanoseconds.
@@ -1170,16 +1171,19 @@
static inline void ap_schedule_poll_timer(void)
{
ktime_t hr_time;
+
+ spin_lock_bh(&ap_poll_timer_lock);
if (ap_using_interrupts() || ap_suspend_flag)
- return;
+ goto out;
if (hrtimer_is_queued(&ap_poll_timer))
- return;
+ goto out;
if (ktime_to_ns(hrtimer_expires_remaining(&ap_poll_timer)) <= 0) {
hr_time = ktime_set(0, poll_timeout);
hrtimer_forward_now(&ap_poll_timer, hr_time);
hrtimer_restart(&ap_poll_timer);
}
- return;
+out:
+ spin_unlock_bh(&ap_poll_timer_lock);
}
/**
@@ -1668,6 +1672,7 @@
*/
if (MACHINE_IS_VM)
poll_timeout = 1500000;
+ spin_lock_init(&ap_poll_timer_lock);
hrtimer_init(&ap_poll_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
ap_poll_timer.function = ap_poll_timeout;