def prepare_inputs(self):
        """
        Returns a list of input parameters that all reside on the target device.
        """
        def ensure_device(parameter):
            if self.is_device_array(parameter):
                convert = self.as_device_array
            else:
                convert = self.to_device

            return convert(parameter)

        return [ensure_device(p) for p in self.inputs]

        Returns a list of input parameters that all reside on the target device.
        
numba/cuda/deviceufunc.py