[PATCH v3 3/7] drm/i915: add generic __to_intel_display()

[Jani Nikula <jani.nikula@intel.com>]

Add generic __to_intel_display() macro that accepts either struct
drm_i915_private * or struct intel_display *. This is to be used for
transitional stuff that eventually needs to be converted to use struct
intel_display *, and therefore is not part of to_intel_display().

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ee0d7d5f135d..4819f80942d3 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -357,6 +357,17 @@ struct drm_i915_private {
 	 */
 };
 
+/*
+ * Transitional macro to optionally convert struct drm_i915_private * to struct
+ * intel_display *, also accepting the latter.
+ */
+#define __to_intel_display(p)						\
+	_Generic(p,							\
+		 const struct drm_i915_private *: (&((const struct drm_i915_private *)(p))->display), \
+		 struct drm_i915_private *: (&((struct drm_i915_private *)(p))->display), \
+		 const struct intel_display *: (p),			\
+		 struct intel_display *: (p))
+
 static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
 {
 	return container_of(dev, struct drm_i915_private, drm);
-- 
2.39.2