drm/ttm: refactor out common code to setup a new tt backed resource

This factors out the code to setup non-system tt.

The same code was used twice in the move paths.
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201019071314.1671485-2-airlied@gmail.com

drivers/gpu/drm/ttm/ttm_bo.c

@@ -252,15 +252,9 @@ static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
 		if (ret)
 			goto out_err;
 
-		if (mem->mem_type != TTM_PL_SYSTEM) {
-			ret = ttm_tt_populate(bdev, bo->ttm, ctx);
-			if (ret)
-				goto out_err;
-
-			ret = ttm_bo_tt_bind(bo, mem);
-			if (ret)
-				goto out_err;
-		}
+		ret = ttm_bo_move_to_new_tt_mem(bo, ctx, mem);
+		if (ret)
+			goto out_err;
 	}
 
 	if (bdev->driver->move_notify)

drivers/gpu/drm/ttm/ttm_bo_util.c

@@ -45,11 +45,30 @@ struct ttm_transfer_obj {
 	struct ttm_buffer_object *bo;
 };
 
+int ttm_bo_move_to_new_tt_mem(struct ttm_buffer_object *bo,
+			      struct ttm_operation_ctx *ctx,
+			      struct ttm_resource *new_mem)
+{
+	int ret;
+
+	if (new_mem->mem_type == TTM_PL_SYSTEM)
+		return 0;
+
+	ret = ttm_tt_populate(bo->bdev, bo->ttm, ctx);
+	if (unlikely(ret != 0))
+		return ret;
+
+	ret = ttm_bo_tt_bind(bo, new_mem);
+	if (unlikely(ret != 0))
+		return ret;
+
+	return 0;
+}
+
 int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
 		   struct ttm_operation_ctx *ctx,
 		    struct ttm_resource *new_mem)
 {
-	struct ttm_tt *ttm = bo->ttm;
 	struct ttm_resource *old_mem = &bo->mem;
 	int ret;
 
@@ -67,16 +86,9 @@ int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
 		old_mem->mem_type = TTM_PL_SYSTEM;
 	}
 
-	if (new_mem->mem_type != TTM_PL_SYSTEM) {
-
-		ret = ttm_tt_populate(bo->bdev, ttm, ctx);
-		if (unlikely(ret != 0))
-			return ret;
-
-		ret = ttm_bo_tt_bind(bo, new_mem);
-		if (unlikely(ret != 0))
-			return ret;
-	}
+	ret = ttm_bo_move_to_new_tt_mem(bo, ctx, new_mem);
+	if (unlikely(ret != 0))
+		return ret;
 
 	ttm_bo_assign_mem(bo, new_mem);
 	return 0;

include/drm/ttm/ttm_bo_driver.h

@@ -593,6 +593,10 @@ int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
 		    struct ttm_operation_ctx *ctx,
 		    struct ttm_resource *new_mem);
 
+int ttm_bo_move_to_new_tt_mem(struct ttm_buffer_object *bo,
+			      struct ttm_operation_ctx *ctx,
+			      struct ttm_resource *new_mem);
+
 /**
  * ttm_bo_move_memcpy
  *