Alex Deucher of AMD had already sent in a pull request to add Radeon userptr support for Linux 3.18 after it just missed the Linux 3.17 merge window due to the user-space support not being tried and tested. In Alex's latest pull request to DRM subsystem maintainer David Airlie, there's more changes than the first.
The main feature of this latest Radeon DRM update for the Linux 3.18 kernel is landing the open-source UVD support for RV600 GPUs that after years of waiting is now finally available to Radeon HD 3000 users on the open-source driver. There's also new firmware/microcode files and a small Mesa patch (already mainline) required for getting this GPU-based video decoding work. Of course, going back to early last year was open-source support for newer versions of UVD.
This latest pull also has reset rework handling in preparation for merging Maarten Lankhorst's fence patches, and there's also a few other changes.
This latest Radeon drm-next work that outlines all sixteen new patches can be found via this mailing list post.