drm/i915: Unbind closed vma for i915_gem_object_unbind()

Closed vma are removed from the obj->vma_list so that they cannot be
found by userspace. However, this means that when forcibly unbinding an
object, we have to wait upon all rendering to that object first in order
for the closed, but active, vma to be reaped and their bindings removed.

Reported-by: Matthew Auld <matthew.auld@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97343
Fixes: aa653a685d81 ("drm/i915: Be more careful when unbinding vma")
Fixes: 8a3b3d576c93 (" drm/i915: Convert non-blocking userptr waits...")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471196681-30043-2-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Tested-by: Matthew Auld <matthew.auld@intel.com>

drivers/gpu/drm/i915/i915_gem.c

@@ -283,11 +283,21 @@ int i915_gem_object_unbind(struct drm_i915_gem_object *obj)
 {
 	struct i915_vma *vma;
 	LIST_HEAD(still_in_list);
-	int ret = 0;
+	int ret;
 
-	/* The vma will only be freed if it is marked as closed, and if we wait
-	 * upon rendering to the vma, we may unbind anything in the list.
+	lockdep_assert_held(&obj->base.dev->struct_mutex);
+
+	/* Closed vma are removed from the obj->vma_list - but they may
+	 * still have an active binding on the object. To remove those we
+	 * must wait for all rendering to complete to the object (as unbinding
+	 * must anyway), and retire the requests.
 	 */
+	ret = i915_gem_object_wait_rendering(obj, false);
+	if (ret)
+		return ret;
+
+	i915_gem_retire_requests(to_i915(obj->base.dev));
+
 	while ((vma = list_first_entry_or_null(&obj->vma_list,
 					       struct i915_vma,
 					       obj_link))) {