diff --git a/arch/s390/include/asm/s390_ext.h b/arch/s390/include/asm/s390_ext.h
index 080876d5f19650aa8cdcbf3d85913fe953109db8..85b2154b899f8113ba669714403e77b8865ee521 100644
--- a/arch/s390/include/asm/s390_ext.h
+++ b/arch/s390/include/asm/s390_ext.h
@@ -13,5 +13,7 @@ typedef void (*ext_int_handler_t)(unsigned int, unsigned int, unsigned long);
 
 int register_external_interrupt(__u16 code, ext_int_handler_t handler);
 int unregister_external_interrupt(__u16 code, ext_int_handler_t handler);
+void service_subclass_irq_register(void);
+void service_subclass_irq_unregister(void);
 
 #endif /* _S390_EXTINT_H */
diff --git a/arch/s390/kernel/s390_ext.c b/arch/s390/kernel/s390_ext.c
index 185029919c4d98fe38440547cf47c1730b8c5a11..87b5c532abf1faf132e85bf4158869c1677493f1 100644
--- a/arch/s390/kernel/s390_ext.c
+++ b/arch/s390/kernel/s390_ext.c
@@ -106,3 +106,26 @@ void __irq_entry do_extint(struct pt_regs *regs, unsigned int ext_int_code,
 	irq_exit();
 	set_irq_regs(old_regs);
 }
+
+static DEFINE_SPINLOCK(sc_irq_lock);
+static int sc_irq_refcount;
+
+void service_subclass_irq_register(void)
+{
+	spin_lock(&sc_irq_lock);
+	if (!sc_irq_refcount)
+		ctl_set_bit(0, 9);
+	sc_irq_refcount++;
+	spin_unlock(&sc_irq_lock);
+}
+EXPORT_SYMBOL(service_subclass_irq_register);
+
+void service_subclass_irq_unregister(void)
+{
+	spin_lock(&sc_irq_lock);
+	sc_irq_refcount--;
+	if (!sc_irq_refcount)
+		ctl_clear_bit(0, 9);
+	spin_unlock(&sc_irq_lock);
+}
+EXPORT_SYMBOL(service_subclass_irq_unregister);
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index e46ba2927424a4461acdd99b7963cd2b96b6a7c3..6e922b50efa45fb8f413d7c83c7265328622a70b 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -613,7 +613,7 @@ static int __init pfault_irq_init(void)
 	rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP;
 	if (rc)
 		goto out_pfault;
-	ctl_set_bit(0, 9);
+	service_subclass_irq_register();
 	hotcpu_notifier(pfault_cpu_notify, 0);
 	return 0;
 
diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
index 85dddb1e4126be512d843ceef08123fd86cc1b0d..5e8e82db188622a7c7a18ffa50e1aff204676f71 100644
--- a/drivers/s390/block/dasd_diag.c
+++ b/drivers/s390/block/dasd_diag.c
@@ -642,7 +642,7 @@ dasd_diag_init(void)
 	}
 	ASCEBC(dasd_diag_discipline.ebcname, 4);
 
-	ctl_set_bit(0, 9);
+	service_subclass_irq_register();
 	register_external_interrupt(0x2603, dasd_ext_handler);
 	dasd_diag_discipline_pointer = &dasd_diag_discipline;
 	return 0;
@@ -652,7 +652,7 @@ static void __exit
 dasd_diag_cleanup(void)
 {
 	unregister_external_interrupt(0x2603, dasd_ext_handler);
-	ctl_clear_bit(0, 9);
+	service_subclass_irq_unregister();
 	dasd_diag_discipline_pointer = NULL;
 }
 
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index b76c61f824857d4ed05d3a38e9657f078098ef90..b37b98cbbd0093b297558ee862c5884d21e3be9d 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -885,12 +885,12 @@ sclp_check_interface(void)
 		spin_unlock_irqrestore(&sclp_lock, flags);
 		/* Enable service-signal interruption - needs to happen
 		 * with IRQs enabled. */
-		ctl_set_bit(0, 9);
+		service_subclass_irq_register();
 		/* Wait for signal from interrupt or timeout */
 		sclp_sync_wait();
 		/* Disable service-signal interruption - needs to happen
 		 * with IRQs enabled. */
-		ctl_clear_bit(0,9);
+		service_subclass_irq_unregister();
 		spin_lock_irqsave(&sclp_lock, flags);
 		del_timer(&sclp_request_timer);
 		if (sclp_init_req.status == SCLP_REQ_DONE &&
@@ -1070,7 +1070,7 @@ sclp_init(void)
 	spin_unlock_irqrestore(&sclp_lock, flags);
 	/* Enable service-signal external interruption - needs to happen with
 	 * IRQs enabled. */
-	ctl_set_bit(0, 9);
+	service_subclass_irq_register();
 	sclp_init_mask(1);
 	return 0;
 
diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index 607998f0b7d8580c05c4fec47cf672bfad9d3c14..724b5923b6e2daae397d9b79bb1900a25dc07444 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -441,7 +441,7 @@ static int __init kvm_devices_init(void)
 
 	INIT_WORK(&hotplug_work, hotplug_devices);
 
-	ctl_set_bit(0, 9);
+	service_subclass_irq_register();
 	register_external_interrupt(0x2603, kvm_extint_handler);
 
 	scan_devices();