Izumi Tsutsui has committed a MI driver for the Symbios/NCR
    53c710 SCSI controller.  It's based on NetBSD/amiga's siop driver, but is
    converted to use bus_space(9) functions and modified to fit
    bus_dma(9) framework.
    
    This driver has been test on NetBSD/arc with jazzio 53c710 SCSI.
    Sync transfers and disconnect/reconnect are also working.
    
    TODO:
    
      - Test under more heavy load
      
- Clean up osiop_checkintr() handler
      
- Reorganize command queue and sync negotiation handling more
        suitable for the newly merged SCSI/ATAPI mid-layer rewrite in
        NetBSD-current.
      
- Re-think deferred interrupt handling for NetBSD/amiga.