s390/irq: rework irq subclass handling

Let's not add a function for every external interrupt subclass for
which we need reference counting. Just have two register/unregister
functions which have a subclass parameter:

void irq_subclass_register(enum irq_subclass subclass);
void irq_subclass_unregister(enum irq_subclass subclass);

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

drivers/s390/char/sclp.c

@@ -910,12 +910,12 @@ sclp_check_interface(void)
 		spin_unlock_irqrestore(&sclp_lock, flags);
 		/* Enable service-signal interruption - needs to happen
 		 * with IRQs enabled. */
-		service_subclass_irq_register();
+		irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
 		/* Wait for signal from interrupt or timeout */
 		sclp_sync_wait();
 		/* Disable service-signal interruption - needs to happen
 		 * with IRQs enabled. */
-		service_subclass_irq_unregister();
+		irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
 		spin_lock_irqsave(&sclp_lock, flags);
 		del_timer(&sclp_request_timer);
 		if (sclp_init_req.status == SCLP_REQ_DONE &&
@@ -1131,7 +1131,7 @@ sclp_init(void)
 	spin_unlock_irqrestore(&sclp_lock, flags);
 	/* Enable service-signal external interruption - needs to happen with
 	 * IRQs enabled. */
-	service_subclass_irq_register();
+	irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
 	sclp_init_mask(1);
 	return 0;