OCXL_NUM_MINORS
minor = idr_alloc(&minors_idr, info, 0, OCXL_NUM_MINORS, GFP_KERNEL);
rc = alloc_chrdev_region(&ocxl_dev, 0, OCXL_NUM_MINORS, "ocxl");
unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS);
unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS);