As long as the kernel is GPL, Nvidia can't use DMA_BUF. That's how GPL works. You'd have to relicense the entire kernel, and that's impossible.
Someone should just fork his code as LGPL
It's better if somebody forks Nvidia's code as LGPL :facepalm:
If its his code, and he won't let anyone touch it, then we'll use the GPL to against him, and show him its OUR code.