Function nexus_alloc_resource

freebsd/mips/mips/nexus.c:278–345

* Allocate a resource on behalf of child. NB: child is usually going to be a * child of one of our descendants, not a direct child of nexus0. * (Exceptions include footbridge.) */

 * (Exceptions include footbridge.)
 */
static struct resource *
nexus_alloc_resource(device_t bus, device_t child, int type, int *rid,
	rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
{
	struct nexus_device		*ndev = DEVTONX(child);
	struct resource			*rv;
	struct resource_list_entry	*rle;
	struct rman			*rm;
	int				 isdefault, needactivate, passthrough;

	dprintf("%s: entry (%p, %p, %d, %p, %p, %p, %jd, %d)\n",
	    __func__, bus, child, type, rid, (void *)(intptr_t)start,
	    (void *)(intptr_t)end, count, flags);
	dprintf("%s: requested rid is %d\n", __func__, *rid);

	isdefault = (RMAN_IS_DEFAULT_RANGE(start, end) && count == 1);
	needactivate = flags & RF_ACTIVE;
	passthrough = (device_get_parent(child) != bus);
	rle = NULL;

	/*
	 * If this is an allocation of the "default" range for a given RID,
	 * and we know what the resources for this device are (ie. they aren't
	 * maintained by a child bus), then work out the start/end values.
	 */
	if (!passthrough && isdefault) {
		rle = resource_list_find(&ndev->nx_resources, type, *rid);
		if (rle == NULL)
			return (NULL);
		if (rle->res != NULL) {
			panic("%s: resource entry is busy", __func__);
		}
		start = rle->start;
		end = rle->end;
		count = rle->count;
	}

	switch (type) {
	case SYS_RES_IRQ:
		rm = &irq_rman;
		break;
	case SYS_RES_MEMORY:
		rm = &mem_rman;
		break;
	default:
		printf("%s: unknown resource type %d\n", __func__, type);
		return (0);
	}

	rv = rman_reserve_resource(rm, start, end, count, flags, child);
	if (rv == NULL) {
		printf("%s: could not reserve resource for %s\n", __func__,
		    device_get_nameunit(child));
		return (0);
	}

	rman_set_rid(rv, *rid);