as described in
http://mail-index.netbsd.org/tech-kern/2012/06/23/msg013442.html
PMP support in integrated to the atabus layer.
struct ata_channel's ch_drive[] is not dynamically allocated, and ch_ndrive
(renamed to ch_ndrives) closely reflects the size of the ch_drive[] array.
Add helper functions atabus_alloc_drives() and atabus_free_drives()
to manage ch_drive[]/ch_ndrives.
Add wdc_maxdrives to struct wdc_softc so that bus front-end can specify
how much drive they really support (master/slave or single).
ata_reset_drive() callback gains a uint32_t *sigp argument which,
when not NULL, will contain the signature of the device being reset.
While there, some cosmetic changes:
- added a drive_type enum to ata_drive_datas, and stop encoding the
probed drive type in drive_flags (we were out of drive flags anyway).
- rename DRIVE_ATAPIST to DRIVE_ATAPIDSCW to better reflect what this
really is
- remove ata_channel->ata_drives, it's redundant with the pointer in
ata_drive_datas
- factor out the interpretation of SATA signatures in sata_interpet_sig()
propagate these changes to the ATA HBA drivers, and add support for PMP
to ahcisata(4) and siisata(4).
Thanks to:
- Protocase (http://www.protocase.com/) which provided a system
with lots of controllers, SATA PMP and drive slots
- Conservation Genomics Laboratory, Department of Biology, New Mexico State
University for hosting the above system
- Brook Milligan, who set up remote access and has been very responsive
when SATA cable move was needed
