drm/i915: ppgtt binding/unbinding support

This adds support to bind/unbind objects and wires it up. Objects are
only put into the ppgtt when necessary, i.e. at execbuf time.

Objects are still unconditionally put into the global gtt.

v2: Kill the quick hack and explicitly pass cache_level to ppgtt_bind
like for the global gtt function. Noticed by Chris Wilson.

Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index b964998..9835b2e 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -515,6 +515,7 @@
 			    struct drm_file *file,
 			    struct list_head *objects)
 {
+	drm_i915_private_t *dev_priv = ring->dev->dev_private;
 	struct drm_i915_gem_object *obj;
 	int ret, retry;
 	bool has_fenced_gpu_access = INTEL_INFO(ring->dev)->gen < 4;
@@ -623,6 +624,14 @@
 			}
 
 			i915_gem_object_unpin(obj);
+
+			/* ... and ensure ppgtt mapping exist if needed. */
+			if (dev_priv->mm.aliasing_ppgtt && !obj->has_aliasing_ppgtt_mapping) {
+				i915_ppgtt_bind_object(dev_priv->mm.aliasing_ppgtt,
+						       obj, obj->cache_level);
+
+				obj->has_aliasing_ppgtt_mapping = 1;
+			}
 		}
 
 		if (ret != -ENOSPC || retry > 1)