Re: drm_bufs.c not compiling on i386-current

["Blair Sadewitz" <blair.sadewitz%gmail.com@localhost>]

I was not aware that btop() did not exist on all platforms--I am now.
;)  Bytes-to-page just seemed like the logical thing to use--I should
have looked in the headers.

Is btoc() what we should be using?  For now, I replaced btop() with
round_page(size) >> PAGE_SHIFT.  Seems to work fine.  I also fixed the
problem where a certain call
to mmap() in DrmMap() returned EINVAL--this
was due to my [obviously] not using bus_space_mmap() correctly in
drm_vm.c.  It worked before I added the code to use the extent
manager, so I'll have to see
why this is happening.

Sorry for the lossage.

--Blair