drm/gem: add hooks to notify driver when object handle is created/destroyed

Nouveau is going to use these hooks to map/unmap objects from a client's
private GPU address space.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 74e4ff5..bad3359 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -210,6 +210,8 @@
 	idr_remove(&filp->object_idr, handle);
 	spin_unlock(&filp->table_lock);
 
+	if (dev->driver->gem_close_object)
+		dev->driver->gem_close_object(obj, filp);
 	drm_gem_object_handle_unreference_unlocked(obj);
 
 	return 0;
@@ -226,7 +228,8 @@
 		       struct drm_gem_object *obj,
 		       u32 *handlep)
 {
-	int	ret;
+	struct drm_device *dev = obj->dev;
+	int ret;
 
 	/*
 	 * Get the user-visible handle using idr.
@@ -247,6 +250,15 @@
 		return ret;
 
 	drm_gem_object_handle_reference(obj);
+
+	if (dev->driver->gem_open_object) {
+		ret = dev->driver->gem_open_object(obj, file_priv);
+		if (ret) {
+			drm_gem_handle_delete(file_priv, *handlep);
+			return ret;
+		}
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL(drm_gem_handle_create);
@@ -401,7 +413,12 @@
 static int
 drm_gem_object_release_handle(int id, void *ptr, void *data)
 {
+	struct drm_file *file_priv = data;
 	struct drm_gem_object *obj = ptr;
+	struct drm_device *dev = obj->dev;
+
+	if (dev->driver->gem_close_object)
+		dev->driver->gem_close_object(obj, file_priv);
 
 	drm_gem_object_handle_unreference_unlocked(obj);
 
@@ -417,7 +434,7 @@
 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
 {
 	idr_for_each(&file_private->object_idr,
-		     &drm_gem_object_release_handle, NULL);
+		     &drm_gem_object_release_handle, file_private);
 
 	idr_remove_all(&file_private->object_idr);
 	idr_destroy(&file_private->object_idr);