This is needed when Thunderbolt service drivers need to DMA map memory
before it is passed down to the ring.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NMichael Jamet <michael.jamet@intel.com>
Reviewed-by: NYehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>