SIOP_DMA_DVA
SIOP_DMA_DVA(siop_cmd->siop_cbdp->xfers);
dsa = SIOP_DMA_DVA(newcbd->xfers) +
if (dsa >= SIOP_DMA_DVA(cbdp->xfers) &&
dsa < SIOP_DMA_DVA(cbdp->xfers) + PAGE_SIZE) {
dsa -= SIOP_DMA_DVA(cbdp->xfers);