AMD Soon Might Have Out AMDGPU Support For The Original GCN GPUs
A Phoronix reader pointed out this comment made two weeks ago by AMD's John Bridgman. When asked about the GCN 1.0 / SI support for the AMDGPU kernel driver, he wrote, "SI support in amdgpu is making pretty good progress, hoping to get the first public code out in the next couple of weeks. Once we have accumulated some test coverage on the CI & SI support and fixed enough bugs that it seems like a decent replacement for radeon upstream we will work with the upstream maintainer to do some organized public testing then enable it by default (disabling radeon for the same chips we enable on amdgpu)."
That comment about hoping to get the SI AMDGPU out in the public "in the next couple of weeks" was made two weeks ago. While the Radeon DRM driver offers mature support for Southern Islands hardware, AMDGPU support is sought after for these original Radeon GCN GPUs so that it will work with AMD's new binary-driver-in-user-space "PRO" stack and as part of that for having Vulkan support. The PRO / Vulkan stacks are designed to only work with the AMDGPU kernel driver and not the Radeon DRM driver that supports older hardware. There will not be any AMDGPU support for pre-GCN GPUs.
Once the SI AMDGPU support is out there in patch form, it will still likely be a while before it appears in a mainline Linux kernel. It's likely too late now to get reviewed and merged into DRM-Next for the Linux 4.7 kernel with that merge window opening next week (especially with DRM maintainer David Airlile not liking last minute work heading to DRM-Next), thus likely will not be material until Linux 4.8. Once that happens, it will still be experimental and disabled-by-default as outlined by Bridgman until sufficient testing happens. The GCN 1.1 hardware is in the same boat with continuing to be turned off in AMDGPU as default behavior while Radeon DRM provides the stable support.
So it will likely be a long road before GCN 1.0/1.1 hardware sees AMDGPU support out-of-the-box, but AMD continues to be working in the right direction.