NTB: Default to CPU memcpy for performance
NTB: Default to CPU memcpy for performance

Disable DMA usage by default, since the CPU provides much better
performance with write combining.  Provide a module parameter to enable
DMA usage when offloading the memcpy is preferred.

Signed-off-by: Dave Jiang <7a72b0ecdf501e4593e842e1a61bf3d5b53699e6@intel.com>
Signed-off-by: Allen Hubbe <92b2227634627929a043144e46bda0ae15eb2cf5@emc.com>
Signed-off-by: Jon Mason <cac3dbc234078e69b21f0609d62c20cd232525f0@kudzu.us>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs