Ideally, no.  As I went on to say, ideally there would be a generic
   bouncebus psuedo-driver implemented as a shim, purely in terms of the
   bus_dma interface and simply proxying most of the routines and calls
   straight through.  I'm not sure if we can presently meet that ideal,
   though, so I started with the more-specific example.


bus_dma doesn't work like this.  there aren't ways "proxy" part of
it.  the tags are setup and how functions work is entirely under
the control of <machine/bus.h>.  there may not be functions at all,
they might be macros.  the only way to handle bouncing currently is
in the MD backend.


"bus shims" are not possible in a MI fashion with bus_dma(9) as-is.


.mrg.