drm/i915/bdw: Limit GTT to 2GB

Because of the way in which we're allocating the pages for the Aliasing
PPGTT, we cannot actually successfully alloc enough space for anything
greater than 2GB.

Instead of a quick hack to fix this, we should defer until we have the
real solution in place (allocating much less contiguous space).

This wasn't found sooner because we didn't not have any systems
supporting more than a 2GB GTT.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Ben Widawsky 2013-11-07 21:40:51 -08:00 committed by Daniel Vetter
parent eb0d4b75d5
commit 3a2ffb65ee

View file

@ -1239,6 +1239,11 @@ static inline unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
if (bdw_gmch_ctl)
bdw_gmch_ctl = 1 << bdw_gmch_ctl;
if (bdw_gmch_ctl > 4) {
WARN_ON(!i915_preliminary_hw_support);
return 4<<20;
}
return bdw_gmch_ctl << 20;
}