drm/i915: Replace __I915__ with typesafe variant
Ville pointed out the GCCism __builtin_types_compatible_p() that we
could use to replace our heavily casted presumption __I915__ macro that
was based on comparing struct sizes.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index eb99a109..2af0071 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2004,8 +2004,16 @@
};
/* Note that the (struct drm_i915_private *) cast is just to shut up gcc. */
-#define __I915__(p) ((sizeof(*(p)) == sizeof(struct drm_i915_private)) ? \
- (struct drm_i915_private *)(p) : to_i915(p))
+#define __I915__(p) ({ \
+ struct drm_i915_private *__p; \
+ if (__builtin_types_compatible_p(typeof(*p), struct drm_i915_private)) \
+ __p = (struct drm_i915_private *)p; \
+ else if (__builtin_types_compatible_p(typeof(*p), struct drm_device)) \
+ __p = to_i915((struct drm_device *)p); \
+ else \
+ BUILD_BUG(); \
+ __p; \
+})
#define INTEL_INFO(p) (&__I915__(p)->info)
#define INTEL_DEVID(p) (INTEL_INFO(p)->device_id)