Linux DMA-BUF protocol

Maintainers:
Pekka Paalanen <pekka.paalanen@collabora.co.uk> (@pq)
Daniel Stone <daniels@collabora.com> (@daniels)

Disclaimer: This protocol extension has been marked stable. This copy is
no longer used and only retained for backwards compatibility. The
canonical version can be found in the stable/ directory.
