Re: Updated drm code

[Arto Huusko <arto.huusko%pp2.inet.fi@localhost>]

> i have merged arto's work with netbsd -current.
>
> i've tested it on a radeon 9000-m card (r200) and it works
> fine.  infact, it works better -- glxgears got a 20% speed
> up.  i haven't pushed it hard yet.

FreeBSD code has some optimizations that I think should be
adapted to NetBSD. I don't know how much of a difference they
would make, but at least some would serve to reduce diffs:

 - FreeBSD has fls, ffsl and flsl on libkern. flsl is
   used to implement drm_order() in drm_bufs.c.
   I think importing those functions from FreeBSD should
   be very simple?

 - FreeBSD supports mapping device pages with write combining.
   See drm_memory.c. I guess bus_space could be adapted to
   support it with some new flags?

 - Newer radeons have Message Signaled Interrupts, and
   drm code base supports it. I couldn't find support for
   them in NetBSD, but didn't look hard.