drm/radeon/kms: add gui_idle callback

Check to see if the GUI engine and related blocks
(2D, 3D, CP, etc) are idle or not.  There are a number
of cases when we need to know if the drawing engine
is busy.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_asic.h b/drivers/gpu/drm/radeon/radeon_asic.h
index ef2c7ba..c74bf9b 100644
--- a/drivers/gpu/drm/radeon/radeon_asic.h
+++ b/drivers/gpu/drm/radeon/radeon_asic.h
@@ -126,6 +126,7 @@
 void r100_enable_bm(struct radeon_device *rdev);
 void r100_set_common_regs(struct radeon_device *rdev);
 void r100_bm_disable(struct radeon_device *rdev);
+extern bool r100_gui_idle(struct radeon_device *rdev);
 /*
  * r200,rv250,rs300,rv280
  */
@@ -269,6 +270,7 @@
 void r600_hpd_set_polarity(struct radeon_device *rdev,
 			   enum radeon_hpd_id hpd);
 extern void r600_ioctl_wait_idle(struct radeon_device *rdev, struct radeon_bo *bo);
+extern bool r600_gui_idle(struct radeon_device *rdev);
 
 /*
  * rv770,rv730,rv710,rv740