intel-iommu: Check for identity mapping candidate using system dma mask

The identity mapping code appears to make the assumption that if the
devices dma_mask is greater than 32bits the device can use identity
mapping.  But that is not true: take the case where we have a 40bit
device in a 44bit architecture. The device can potentially receive a
physical address that it will truncate and cause incorrect addresses
to be used.

Instead check to see if the device's dma_mask is large enough
to address the system's dma_mask.

Signed-off-by: Mike Travis <[email protected]>
Reviewed-by: Mike Habeck <[email protected]>
Cc: [email protected]
Signed-off-by: David Woodhouse <[email protected]>

0 files changed, 0 insertions, 0 deletions