The Radeon™ R7 300, R9 295X2, R9 280X, R9 280, R9 270X, R9 270, R7 265, R7 250X, R7 250, R7 240, HD 8500 - HD 8900, and HD 7700 – HD 7900 Series
only have support for Ubuntu 15.10 or lower,
to be more detailed is support being added to the AMDGPU-PRO Driver for Linux for R9280 and R7370 .
hopefully AMD is able to provide updated drivers for the new kernel, I suggest checking that link occasionally and see if anything new is posted
I do keep checking and i know asking for a time frame can be pointless sometimes and some times not so i ask sense it been taking awhile which is cool i understand why .