Dave Airlie spotted that his ILK laptop with DMAR enabled was generating
the occasional DMAR warning.

"The ordering in the previous code was to rewrite the GTT table before
unmapping the pages and that makes sense to me."

This is his stable patch ported to d-i-n.
Reported-by: Dave Airlie <airlied@redhat.com>
Original-patch-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Required for my pineview system to not barf after resuming.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

A glorified s/obj_priv/obj/ with a net reduction of over a 100 lines and
many characters!
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

No more drm_*_agp in i915_gem.c!
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

This still uses the agp functions to actually reinstate the mappings
(with a gross hack to make agp cooperate), but it wires everything
up correctly for the switchover.

The call to agp_rebind_memory can be dropped because all non-kms drivers
do all their rebinding on EnterVT.

v2: Be more paranoid and flush the chipset cache after restoring gtt
mappings.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Now that the drm core can do this, lets just use it, split the code out
so TTM doesn't have to drag all of drmP.h in.
Signed-off-by: Dave Airlie <airlied@redhat.com>