MPI_DOORBELL_DWORDS_SHIFT   54 dev/ic/mpireg.h #define  MPI_DOORBELL_DWORDS_MASK	(0xff << MPI_DOORBELL_DWORDS_SHIFT)
MPI_DOORBELL_DWORDS_SHIFT   56 dev/ic/mpireg.h     (((x) << MPI_DOORBELL_DWORDS_SHIFT) & MPI_DOORBELL_DWORDS_MASK)