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: NBen Skeggs <bskeggs@redhat.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_gem.c

@@ -210,6 +210,8 @@ drm_gem_handle_delete(struct drm_file *filp, u32 handle)
 	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;
@@ -226,6 +228,7 @@ drm_gem_handle_create(struct drm_file *file_priv,
 		       struct drm_gem_object *obj,
 		       u32 *handlep)
 {
+	struct drm_device *dev = obj->dev;
 	int ret;
 
 	/*
@@ -247,6 +250,15 @@ drm_gem_handle_create(struct drm_file *file_priv,
 		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 @@ drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
 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 @@ void
 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);

include/drm/drmP.h

@@ -886,6 +886,8 @@ struct drm_driver {
 	 */
 	int (*gem_init_object) (struct drm_gem_object *obj);
 	void (*gem_free_object) (struct drm_gem_object *obj);
+	int (*gem_open_object) (struct drm_gem_object *, struct drm_file *);
+	void (*gem_close_object) (struct drm_gem_object *, struct drm_file *);
 
 	/* vga arb irq handler */
 	void (*vgaarb_irq)(struct drm_device *dev, bool state);