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Commit 93521314 authored by Felix Beck's avatar Felix Beck Committed by Martin Schwidefsky
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[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: default avatarFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 7a6f5cd0

drivers/s390/crypto/ap_bus.c

+8 −3
Original line number Diff line number Diff line
@@ -102,6 +102,7 @@ static atomic_t ap_poll_requests = ATOMIC_INIT(0); 
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 @@ ap_config_timeout(unsigned long ptr) 
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 @@ int __init ap_module_init(void) 
	 */

	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;