Function device_add_child_ordered

freebsd/kern/subr_bus.c:1885–1922

* @brief Create a new device * * This creates a new device and adds it as a child of an existing * parent device. The new device will be added after the last existing * child with the same order. * * @param dev the device which will be the parent of the * new child device * @param order a value which is used to partially sort the * children of @p dev - devices created using * low

 * @returns		the new device
 */
device_t
device_add_child_ordered(device_t dev, u_int order, const char *name, int unit)
{
	device_t child;
	device_t place;

	PDEBUG(("%s at %s with order %u as unit %d",
	    name, DEVICENAME(dev), order, unit));
	KASSERT(name != NULL || unit == -1,
	    ("child device with wildcard name and specific unit number"));

	child = make_device(dev, name, unit);
	if (child == NULL)
		return (child);
	child->order = order;

	TAILQ_FOREACH(place, &dev->children, link) {
		if (place->order > order)
			break;
	}

	if (place) {
		/*
		 * The device 'place' is the first device whose order is
		 * greater than the new child.
		 */
		TAILQ_INSERT_BEFORE(place, child, link);
	} else {
		/*
		 * The new child's order is greater or equal to the order of
		 * any existing device. Add the child to the tail of the list.
		 */
		TAILQ_INSERT_TAIL(&dev->children, child, link);
	}

	bus_data_generation_update();
	return (child);
}

/**
 * @brief Delete a device