xen/events: support threaded irqs for interdomain event channels

Export bind_interdomain_evtchn_to_irq() so drivers can use threaded
interrupt handlers with:

 irq = bind_interdomain_evtchn_to_irq(remote_dom, remote_port);
 if (irq < 0)
     /* error */
 ret = request_threaded_irq(...);
Signed-off-by: NJuergen Gross <jgross@suse.com>
Acked-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

drivers/xen/events/events_base.c

@@ -900,8 +900,8 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 	return irq;
 }
 
-static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
-					  unsigned int remote_port)
+int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
+				   unsigned int remote_port)
 {
 	struct evtchn_bind_interdomain bind_interdomain;
 	int err;
@@ -914,6 +914,7 @@ static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 
 	return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 }
+EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq);
 
 static int find_virq(unsigned int virq, unsigned int cpu)
 {

include/xen/events.h

@@ -28,6 +28,8 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi,
 			   unsigned long irqflags,
 			   const char *devname,
 			   void *dev_id);
+int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
+				   unsigned int remote_port);
 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
 					  unsigned int remote_port,
 					  irq_handler_t handler,