bus dma: a flag/quirk for page zero

[Andriy Gapon]

on 11/01/2012 19:18 Andriy Gapon said the following:
> Actually, I think that on x86 we don't have to do anything special for any memory
> allocations that we do, including the bounce pages, as the page zero is excluded
> from phys_avail and is not available for normal use.

After some additional thinking there is probably no reason to take advantage of
this fact.  First, it would increase differences with other platforms.  Second,
it would add a hidden dependency.  So it's better to be explicit here.

-- 
Andriy Gapon