1 files changed, 23 insertions, 0 deletions

diff --git a/arch/s390/kernel/s390_ext.c b/arch/s390/kernel/s390_ext.c
index 185029919c4d..87b5c532abf1 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);