I want to calculate all the detail orders with quantity * price, I do not want one by one if not all

Delimiter //
Create procedure sp_CalcularSubtotal (in _id_detalle_pedido int)   
BEGIN
declare subtotal int;
set subtotal= (select sum(Cantidad*Precio) from detalle_pedido join producto on  Producto=ID_Producto  where Producto = ID_Producto and  ID_Detalle_Pedido=_id_detalle_pedido );
update detalle_pedido
set SubTotal = subtotal where ID_Detalle_Pedido=_id_detalle_pedido ;
End//