WIP cl_ext_image_drm_format_modifier

[kpet]

• [ ] Do we need a Vulkan mechanism to get a DRM format modifier for an image exported from Vulkan?

[bcalidas]

Sharing some initial feedback.

1. For cl_ext_image_tiling_control, is there really a need for the CL_DEVICE_IMAGE_TILING_DEVICE_ACCESS_EXT token.

2. For cl_ext_image_tiling_control does CL_DEVICE_IMAGE_TILING_HOST_ACCESS_EXT relate to whether or not the implementation will detile the image on mapping?

3. For cl_ext_image_tiling_control, is there an assumption that the image is linear if no explicit tiling mode is forced. To us it seemed that the spec implicitly suggested optimal tiling by default.

4. For cl_ext_image_drm_format_modifer, why would a drm format modifier be required for an image. Shouldn't drm format modifiers be viewed as a decoration of top of optimal tiling. Our thinking was that drm format modifiers would be applied only when importing an optimally tiled image. Additionally, they could be queried for any image ( including linear ) but an application would only make the query when exporting an image.

5. For cl_ext_image_drm_format_modifier, how are we planning to manage the drm format modifier header file from the implementation side and from the application side.