s390/zcrypt: Fixed attrition of AP adapters and domains

Currently the first eligible AP adapter respectively domain will be
selected to service requests. In case of sequential workload, the
very same adapter/domain will be used.

The adapter/domain selection algorithm now considers the completed
transactions per adaper/domain and therefore ensures a homogeneous
utilization.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/crypto/ap_card.c b/drivers/s390/crypto/ap_card.c
index 731dc0d..0110d44 100644
--- a/drivers/s390/crypto/ap_card.c
+++ b/drivers/s390/crypto/ap_card.c
@@ -63,13 +63,11 @@ static ssize_t ap_request_count_show(struct device *dev,
 				     char *buf)
 {
 	struct ap_card *ac = to_ap_card(dev);
-	struct ap_queue *aq;
 	unsigned int req_cnt;
 
 	req_cnt = 0;
 	spin_lock_bh(&ap_list_lock);
-	for_each_ap_queue(aq, ac)
-		req_cnt += aq->total_request_count;
+	req_cnt = atomic_read(&ac->total_request_count);
 	spin_unlock_bh(&ap_list_lock);
 	return snprintf(buf, PAGE_SIZE, "%d\n", req_cnt);
 }