drm/radeon/kms: add support for interrupts on SI

This is mostly identical to evergreen/ni, however
there are some additional fields in the IV vector
for RINGID and VMID.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 5eb2382..924b687 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -2778,7 +2778,7 @@
 	rdev->ih.rptr = 0;
 }
 
-static int r600_ih_ring_alloc(struct radeon_device *rdev)
+int r600_ih_ring_alloc(struct radeon_device *rdev)
 {
 	int r;
 
@@ -2814,7 +2814,7 @@
 	return 0;
 }
 
-static void r600_ih_ring_fini(struct radeon_device *rdev)
+void r600_ih_ring_fini(struct radeon_device *rdev)
 {
 	int r;
 	if (rdev->ih.ring_obj) {