I'm trying to get the CyberBlade EXA driver into a bit better shape, and 
that means some sort of decent host<->fb DMA support.  The device 
itself is apparently capable of that, but EXA has trouble since it only 
has the user virtual address of the transfers it wants to make, so I 
thought a DRM driver might be in order.  It's also necessary for decent 
VBLANK support, which will hopefully be pretty straightforward.  Note 
that at this point, the DRM driver won't do you any good since I 
haven't checked the EXA stuff that uses it into X.Org CVS yet (and 
afaik there's no DRI driver for this device either).

Any thoughts on how the host<->fb DMA stuff should work?  Basically EXA 
UploadToScreen wants to hand the card a virtual address range and have 
it loaded up to the card's VRAM; DownloadFromScreen wants to do the 
same in reverse.  Should I just add a device specific DRM_IOCTL to 
accomplish this (using get_user_pages() etc.) or is there some existing 
code I could leverage?

Thanks,
Jesse

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>