Hi.  While doing some MI device driver work I noticed that sparc's
softintr(9) implementation needs some fleshing out - currently,
softintr_establish() registers everything at priority level 1.
To get anything different you have to go outside softintr(9) and
use bus_intr_establish() and do a raise() or ienab_bis() by hand.

The following patch makes sparc's softintr(9) more universal and 
does away with BUS_INTR_ESTABLISH_SOFTINTR.  

ftp://ftp.netbsd.org/pub/NetBSD/misc/fredette/sparc-softintr.diff

I compiled and booted a GENERIC with this on my SS20, but the only
softintr-using things it has are the zs'es, softclock, and softnet, 
which seem fine.  The changes were more mechanical than not; still, 
I'd appreciate others testing amdaudio, fd, and especially sun4/sun4c.

This patch also removes BUS_INTR_ESTABLISH_SOFTINTR from sparc64.
sparc64 already has a full softintr(9), so those changes were minimal.
I compiled a sparc64 GENERIC but don't have any sparc64 hardware.

Comments and/or "ok to commit" welcome.  Thanks!

-- 
Matt Fredette