>So, what's the current state of the smp for sparc? I have an old
>Quad SS20 that I'm thinking of installing NetBSD on.

Depends on your cpus.  If you have Ross Hypersparc's as in:

cpu0 at mainbus0: RT620/625 @ 100 MHz, on-chip FPU

then, no it doesn't work.  These particular cpu's need some extra
help wrt cache coherency, and I don't know that anyone has the needed
docs to fix it.  (I've got four of those cpu's as well ;-)

--sjg