eeh@netbsd.org writes:
> Given that this is supposed to reduce confusion, I'd prefer to lop
> off some of the letters at the front rather than the part with 
> real significance.  Is BUS_SPACE_BARRIER_W_R obvious as to what
> it does?

Uh, is "BUS_SPACE_BARRIER_WRITE_READ" obvious as to what it does?!