On Mon, 2009-05-18 at 08:25 -0500, Kumar Gala wrote:

Part of this is how the generic swiotlb code works and part of it
was  
our desire not to bloat dev archdata by adding such info that as you  
say is either bus specific or conveyed in the dma addr mask.

Right but perf sucks :-)

Maybe an option is to clamp the DMA mask when it's set by the driver to
limit it to the available inbound window ?

Cheers,
Ben.