radeon memory map & DRM patch

[Benjamin Herrenschmidt]

> > Justo to inform author. The XAA regresion is still present on my current setup. Running glxgears still cause a heavy corruption on desktop (Corruption is gone as soon as I close gears window)
> 
> Have you tried to disable PageFlipping in xorg.conf? That resolved the
> issue for me.

There is a bug with PageFlipping with the new code that I haven't found
yet. I'll commit a fix as soon as I figure it out.

So pease tell us indeed if it works with PF. off, also tell us if it
works with EXA.

Ben.