this device is a ata controller that might just work with
plan9's generic ata driver (given you add the pci id).
i checked 9front sdide.c which has the pci id for the controller:
case (0x03ec<<16)|0x10DE: /* nVidia nForce 61 MCP SATA */
we add these pci id's as we encounter the device so it has been
tested and worked (at least at some point) with 9front.
so i highly recommend just adding the pci device id to your ide/ata
driver and try it out. this is not some rocket science justifying a
gsoc project. :)
--
cinap