00d4b2bb03
An IOMMU device can only be attached to one IOMMU domain at any given time. Check whether the device is already attached to a domain before allowing it to be attached to another domain. If so, return busy. Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org> Signed-off-by: Daniel Walker <dwalker@codeaurora.org>