This reverts commit 583bbf46133c726bae277e8f4e32bfba2a528c7f. Turns out we need mmap to work on imported BOs even if the current code is buggy. Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Sean Paul <sean@poorly.run> Link: https://patchwork.freedesktop.org/patch/msgid/20190807145253.2037-3-sean@poorly.run