[PATCH 4/5] xen/irq: Export 'xen_pirq_from_irq' function.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

We need this to find the real Xen PIRQ value for a device
that requests an MSI or MSI-X. In the past we used
'xen_gsi_from_irq' since that function would return
an Xen PIRQ or GSI depending on the provided IRQ. Now that
we have seperated that we need to use the correct
function.

[v2: Deal with rebase on stable/irq.cleanup]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 drivers/xen/events.c |    6 ++++++
 include/xen/events.h |    3 +++
 2 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 0ac7a14..e4e8e9a 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -763,6 +763,12 @@ out:
 	return irq;
 }
 
+
+int xen_pirq_from_irq(unsigned irq)
+{
+	return pirq_from_irq(irq);
+}
+EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 int bind_evtchn_to_irq(unsigned int evtchn)
 {
 	int irq;
diff --git a/include/xen/events.h b/include/xen/events.h
index 932e540..9af21e1 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -95,6 +95,9 @@ int xen_destroy_irq(int irq);
 /* Return irq from pirq */
 int xen_irq_from_pirq(unsigned pirq);
 
+/* Return the pirq allocated to the irq. */
+int xen_pirq_from_irq(unsigned irq);
+
 /* Determine whether to ignore this IRQ if it is passed to a guest. */
 int xen_test_irq_shared(int irq);
 
-- 
1.7.1