drm/ttm: use a static ttm_mem_global instance

As the name says we only need one global instance of ttm_mem_global.

Drop all the driver initialization and just use a single exported
instance which is initialized during BO global initialization.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/mgag200/mgag200_drv.h

@@ -212,7 +212,6 @@ struct mga_device {
 	int fb_mtrr;
 
 	struct {
-		struct drm_global_reference mem_global_ref;
 		struct ttm_bo_global_ref bo_global_ref;
 		struct ttm_bo_device bdev;
 	} ttm;

drivers/gpu/drm/mgag200/mgag200_ttm.c

@@ -36,37 +36,11 @@ mgag200_bdev(struct ttm_bo_device *bd)
 	return container_of(bd, struct mga_device, ttm.bdev);
 }
 
-static int
-mgag200_ttm_mem_global_init(struct drm_global_reference *ref)
-{
-	return ttm_mem_global_init(ref->object);
-}
-
-static void
-mgag200_ttm_mem_global_release(struct drm_global_reference *ref)
-{
-	ttm_mem_global_release(ref->object);
-}
-
 static int mgag200_ttm_global_init(struct mga_device *ast)
 {
 	struct drm_global_reference *global_ref;
 	int r;
 
-	global_ref = &ast->ttm.mem_global_ref;
-	global_ref->global_type = DRM_GLOBAL_TTM_MEM;
-	global_ref->size = sizeof(struct ttm_mem_global);
-	global_ref->init = &mgag200_ttm_mem_global_init;
-	global_ref->release = &mgag200_ttm_mem_global_release;
-	r = drm_global_item_ref(global_ref);
-	if (r != 0) {
-		DRM_ERROR("Failed setting up TTM memory accounting "
-			  "subsystem.\n");
-		return r;
-	}
-
-	ast->ttm.bo_global_ref.mem_glob =
-		ast->ttm.mem_global_ref.object;
 	global_ref = &ast->ttm.bo_global_ref.ref;
 	global_ref->global_type = DRM_GLOBAL_TTM_BO;
 	global_ref->size = sizeof(struct ttm_bo_global);
@@ -75,7 +49,6 @@ static int mgag200_ttm_global_init(struct mga_device *ast)
 	r = drm_global_item_ref(global_ref);
 	if (r != 0) {
 		DRM_ERROR("Failed setting up TTM BO subsystem.\n");
-		drm_global_item_unref(&ast->ttm.mem_global_ref);
 		return r;
 	}
 	return 0;
@@ -84,12 +57,11 @@ static int mgag200_ttm_global_init(struct mga_device *ast)
 static void
 mgag200_ttm_global_release(struct mga_device *ast)
 {
-	if (ast->ttm.mem_global_ref.release == NULL)
+	if (ast->ttm.bo_global_ref.ref.release == NULL)
 		return;
 
 	drm_global_item_unref(&ast->ttm.bo_global_ref.ref);
-	drm_global_item_unref(&ast->ttm.mem_global_ref);
-	ast->ttm.mem_global_ref.release = NULL;
+	ast->ttm.bo_global_ref.ref.release = NULL;
 }