1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 332dd63750a0..0e0c28574af8 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -734,6 +734,33 @@ static void restore_cpu_ipis(unsigned int cpu)
         }
 }
 
+/* Clear an irq's pending state, in preparation for polling on it */
+void xen_clear_irq_pending(int irq)
+{
+        int evtchn = evtchn_from_irq(irq);
+
+        if (VALID_EVTCHN(evtchn))
+                clear_evtchn(evtchn);
+}
+
+/* Poll waiting for an irq to become pending.  In the usual case, the
+   irq will be disabled so it won't deliver an interrupt. */
+void xen_poll_irq(int irq)
+{
+        evtchn_port_t evtchn = evtchn_from_irq(irq);
+
+        if (VALID_EVTCHN(evtchn)) {
+                struct sched_poll poll;
+
+                poll.nr_ports = 1;
+                poll.timeout = 0;
+                poll.ports = &evtchn;
+
+                if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
+                        BUG();
+        }
+}
+
 void xen_irq_resume(void)
 {
         unsigned int cpu, irq, evtchn;