zaius: Add slots for the Barreleye G2 HDD rack
zaius: Add slots for the Barreleye G2 HDD rack

The Barreleye G2 is distinct from the Zaius in that it features a 24
Bay NVMe/SATA HDD rack. To provide meaningful slot names for each NVMe
device we need to define a slot table for the NVMe capable HDD bays.

Unfortunately this isn't straightforward because the PCIe path to the
NVMe devices isn't fixed. The PCIe topology is something like:

	P9 -> HBA card -> 9797 switch -> 20x NVMe HDD slots

The 9797 switch is partitioned into two (or four) virtual switches which
allow multiple HBA cards to be used (e.g. one per socket). As a result
the exact BDFN of the ports will vary depending on how the system is
configured.

That said, the virtual switch configuration of the 9797 does not change
the device and function numbers of the switch downports. This means that
we can define a single slot table that maps switch ports to the NVMe bay
names.

Unfortunately we still need to guess which bus to use this table on, so
we assume that any switch downport we find with the PEX9797 VDID is part
of the 9797 that supports the HDD rack.

Signed-off-by: Oliver O'Halloran <3dfaff8fa6ae977f042064a112a6aac576279b9b@gmail.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

shenki/skiboot,qemu/skiboot,shenki/skiboot,legoater/skiboot,stewart-ibm/skiboot,open-power/skiboot,legoater/skiboot,open-power/skiboot,qemu/skiboot,shenki/skiboot,shenki/skiboot,qemu/skiboot,open-power/skiboot,stewart-ibm/skiboot,open-power/skiboot,shenki/skiboot,legoater/skiboot,legoater/skiboot,stewart-ibm/skiboot,legoater/skiboot,qemu/skiboot,qemu/skiboot,open-power/skiboot