With discrete GPUs, we aren't able to change mapping modes after we've
created a buffer. This is a limitation of TTM. However, we already
have a buffer cache and it's pretty likely that stuff in any given
memzone will end up with just the one mapping type anyway so this
shouldn't have much of a cost.
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11583>
Jason Ekstrand
dd890f520e