This repository doesn't contain any Linux sources whatsoever as all improvements and fixes for ARC cores are submitted directly to upstream project.
Please visit https://www.kernel.org/ if you're looking for stable releases of the Linux kernel or https://git.kernel.org/ if you're interested in a bleeding edge sources.
Quite a lot of interesting an useful articles could be found in the Wiki section of this repository
Please feel free to reprort observed problems with Linux kernel port for ARC in Issues section of this repo.