don't take an arg, but swi_generic() is special in order to avoid one
whole conditional branch in the old SWI dispatch code. The new SWI
dispatch code passed it a garbage arg. Bypass swi_generic() and call
swi_dispatcher() directly, like the corresponding alpha code has always
done.
The panic was rare because because it only occurred if more than one
of the {sio,cy,rc} drivers was configured and one was active, and the
cy driver doesn't even compile.
include:
* Mutual exclusion is used instead of spl*(). See mutex(9). (Note: The
alpha port is still in transition and currently uses both.)
* Per-CPU idle processes.
* Interrupts are run in their own separate kernel threads and can be
preempted (i386 only).
Partially contributed by: BSDi (BSD/OS)
Submissions by (at least): cp, dfr, dillon, grog, jake, jhb, sheldonh
