SCSI_DMA_READ_P
unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr;
SCSI_DMA_READ_P(dma_addr));
(SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr);
phys_dst = SCSI_DMA_READ_P(dma_addr);