Mesa 26.3 RADV + RadeonSI Ready With DRM Format Modifiers For Older AMD GPUs

Coming with Linux 7.3 is DRM format modifiers for GFX6 through GFX8 era GPUs covering the original Raddeon HD 7000 (GCN 1.0) graphics cards up through the Polaris and Fiji series. This work by Valve's Timur Kristóf is necessary for these older GPUs to support Vulkan-based Wayland compositors, better interoperability between OpenGL and Vulkan or other APis, compositors running on the Zink OpenGL-on-Vulkan driver implementation, and other benefits. Now merged for Mesa 26.3 is the RadeonSI and RADV user-space side support for making use of the format modifiers on these older GPUs. With the AMDGPU GFX6 to GFX8 DRM format modifiers merged for the current Linux 7.3 cycle, which will debut as stable in October, the Mesa side patches have been merged for Mesa 26.3 that in turn should debut as stable in November. DRM format modifiers provide details on tiling, compression, and other attributes for image buffers. Depending upon the layout it can also help with better performance and other more versatile use-cases. This merge by Timur Kristóf that landed in Mesa Git today contains all the Mesa side changes for this GFX6 to GFX8 modifier support. GFX9 and newer was already supported by AMDGPU and Mesa.