I've created a patch of my efforts based on the 2.6.38. It only really works with a single core, with USB being a bit intermittent.
I'm getting a bit frustrated with how Oxnas/PLX have butchered in support in the original 2.6.31 tree. Not having any documentation either hasn't helped matters.
Has anyone else tried anything simular?
Take a look, distribute, improve, enjoy.