drm/i915: Use the direct mapping of pipe->crtc

Why iterate all the crtcs to find the pipe, when we already know which
crtc is attached to which pipe?

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 454bcf3..ba94944 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -177,6 +177,13 @@
 #define to_intel_encoder(x) container_of(x, struct intel_encoder, base)
 #define to_intel_framebuffer(x) container_of(x, struct intel_framebuffer, base)
 
+static inline struct drm_crtc *
+intel_get_crtc_for_pipe(struct drm_device *dev, int pipe)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	return dev_priv->pipe_to_crtc_mapping[pipe];
+}
+
 struct intel_unpin_work {
 	struct work_struct work;
 	struct drm_device *dev;
@@ -235,7 +242,6 @@
 				struct drm_file *file_priv);
 extern void intel_wait_for_vblank_off(struct drm_device *dev, int pipe);
 extern void intel_wait_for_vblank(struct drm_device *dev, int pipe);
-extern struct drm_crtc *intel_get_crtc_from_pipe(struct drm_device *dev, int pipe);
 extern struct drm_crtc *intel_get_load_detect_pipe(struct intel_encoder *intel_encoder,
 						   struct drm_connector *connector,
 						   struct drm_display_mode *mode,