BSDL code is fine in the GPLv2 kernel. E.g., most of the DRM drivers are dual BSD-GPL licensed.
Re:Show HN: ZFS Implementation in Python
by lunixbochs on Saturday May 04, 2019 @02:11PM
(#19828146)
BSD is a subset of GPL's restrictions, so you can include BSD-licensed code in a GPL work.
Except, it seems this is BSD-licensed, so I'm not sure how that would work in the kernel (which is GPLv2).