[parisc-linux] How retrieving HPA/SPA with the device node

Grant Grundler grundler@dsl2.external.hp.com
Mon, 03 Jun 2002 14:38:19 -0600


Bruno Vidal wrote:
> Can someone can explain what is the difference between the
> "hpa" of a scsi card (pci or not) and the "base" in the structure Scsi_Host ?

hpa and base are "handles" for different views of HW.
"hpa" doesn't have to be a physical address (though it normally is).
On V-class, the hpa is bogus and just a reference to particular IO device.
base could be "adjusted" (like the LASI example) or "F-extended"
for 64-bit or whatever the platform code thinks the driver needs
to reference the device properly.

But in practice, for the platforms we support to date, I think you
can compare them (or compare most of the bits) to determine
if it's the same device.

grant