linux

drm/{i915,xe}: driver agnostic drm to display pointer chase The display driver needs to get from the struct drm_device pointer to the struct intel_display pointer. Currently, this depends on knowledge of the struct drm_i915_private and struct xe_device definitions, but we'd like to hide those definitions from display. Require the struct drm_device and struct intel_display * members within struct drm_i915_private and struct xe_device to be placed next to each other, to be able to figure out the display pointer without knowledge of the structures. Use a generic dummy device structure to define the relative offsets of the drm and display members, and add static assertions to ensure this holds for both i915 and xe. Use the dummy structure to do the pointer chase from struct drm_device * to struct intel_display *. This requires moving the display member in struct xe_device after the drm member. Cc: Lucas De Marchi <lucas.demarchi@intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Suggested-by: Simona Vetter <simona.vetter@ffwll.ch> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com> Link: https://lore.kernel.org/r/20250926111032.1188876-1-jani.nikula@intel.com Signed-off-by: Jani Nikula <jani.nikula@intel.com> 2025-09-26 14:10:32 +03:00