drm/i915: add HAS_ALIASING_PPGTT parameter for userspace
authorDaniel Vetter <daniel.vetter@ffwll.ch>
Wed, 15 Feb 2012 22:50:25 +0000 (23:50 +0100)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 20 Mar 2012 20:55:40 +0000 (21:55 +0100)
commit777ee96f50d8c3ac4ff3dde9ad69c22779ac88cb
treebfd67435b0d900d46e9f92d8ab1ced659506c5ce
parent0ebb98299357e1dbeeea470eec29241263c8f244
drm/i915: add HAS_ALIASING_PPGTT parameter for userspace

On Sanybridge a few MI read/write commands only work when ppgtt is
enabled.  Userspace therefore needs to be able to check whether ppgtt
is enabled. For added hilarity, you need to reset the "use global GTT"
bit on snb when ppgtt is enabled, otherwise it won't work.  Despite
what bspec says about automatically using ppgtt ...

Luckily PIPE_CONTROL (the only write cmd current userspace uses) is
not affected by all this, as tested by tests/gem_pipe_control_store_loop.

Reviewed-and-tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_dma.c
include/drm/i915_drm.h