On Wed, Jan 30, 2008 at 01:14:03AM +1100, Michael Ellerman wrote:

For example a machine with 4GB of memory would end up with the normal
IOMMU window from 0-2GB and the fixed mapping window from 2GB to 6GB. In
this case a 64-bit device wishing to DMA to 1GB would be told to DMA to
3GB, plus any offset required by firmware. The firmware offset is encoded
in the "dma-ranges" property.

Shouldn't the fixed mapping be between 4G and 8G (and the offset for 1G
is at 5G), to account for the MMIO range at 2-4G?


-Olof