This adds modifier support to radeonsi. It has been tested on
- VEGA10, RAVEN, NAVI14 - weston, sway, X with xf86-video-amdgpu (i.e. legacy path still works)
and includes some basic testing of the layout code.
The main goal is to keep it somewhat simple and regression free, so on the display side this series only exposes what the current GPU can render to. While we could expose more I think that is more suitable for follow-up work as the benefit would be minimal and there are some more design discussion there to discuss that are orthogonal from the initial implementation.
Similarly this series only exposes 32-bpp displayable DCC in the cases that radeonsi would use it and any extra capabilities here should be future work.
I believe these are by far the most complicated modifiers we've seen up till now, mostly related to
- GPU identification for cases where it matters wrt tiling. - Every generation having tiling layout changes - Compression settings.
I believe the complexity is necessary as every layout should be different and all layouts should be the best in some situation (though not all combinations of GPU parameters will actually have an existing GPU).
That said, on the render side the number of modifiers actually listed for a given GPU is ~10, and in the current implementation that is the same for the display side. (we could expose more actually differing layouts on the display side for cross-GPU compatibility, but I consider that out of scope for this initial work).
This series can be found on https://github.com/BNieuwenhuizen/linux/tree/modifiers
An userspace implementation in radeonsi can be found on https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6176
Bas Nieuwenhuizen (8): drm/amd/display: Do not silently accept DCC for multiplane formats. drm/amd: Init modifier field of helper fb. drm/amd/display: Honor the offset for plane 0. drm/fourcc: Add AMD DRM modifiers. drm/amd/display: Refactor surface tiling setup. drm/amd/display: Set DC options from modifiers. drm/amd/display: Add formats for DCC with 2/3 planes. drm/amd/display: Expose modifiers.
drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c | 2 +- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 758 +++++++++++++++--- include/uapi/drm/drm_fourcc.h | 115 +++ 3 files changed, 775 insertions(+), 100 deletions(-)