drm/etnaviv: remove unused function etnaviv_gem_mapping_reference

Hasn't been used for quite a while. There is no point in keeping
unused code around.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Guido Günther <agx@sigxcpu.org>

drivers/gpu/drm/etnaviv/etnaviv_gem.c

@@ -235,18 +235,6 @@ etnaviv_gem_get_vram_mapping(struct etnaviv_gem_object *obj,
 	return NULL;
 }
 
-void etnaviv_gem_mapping_reference(struct etnaviv_vram_mapping *mapping)
-{
-	struct etnaviv_gem_object *etnaviv_obj = mapping->object;
-
-	drm_gem_object_get(&etnaviv_obj->base);
-
-	mutex_lock(&etnaviv_obj->lock);
-	WARN_ON(mapping->use == 0);
-	mapping->use += 1;
-	mutex_unlock(&etnaviv_obj->lock);
-}
-
 void etnaviv_gem_mapping_unreference(struct etnaviv_vram_mapping *mapping)
 {
 	struct etnaviv_gem_object *etnaviv_obj = mapping->object;

drivers/gpu/drm/etnaviv/etnaviv_gem.h

@@ -120,7 +120,6 @@ void etnaviv_gem_put_pages(struct etnaviv_gem_object *obj);
 
 struct etnaviv_vram_mapping *etnaviv_gem_mapping_get(
 	struct drm_gem_object *obj, struct etnaviv_gpu *gpu);
-void etnaviv_gem_mapping_reference(struct etnaviv_vram_mapping *mapping);
 void etnaviv_gem_mapping_unreference(struct etnaviv_vram_mapping *mapping);
 
 #endif /* __ETNAVIV_GEM_H__ */