static int rio_enum_peer()

in rio-scan.c [522:694]

• 138 lines of code
• 27 McCabe index (conditional complexity)

static int rio_enum_peer(struct rio_net *net, struct rio_mport *port,
			 u8 hopcount, struct rio_dev *prev, int prev_port)
{
	struct rio_dev *rdev;
	u32 regval;
	int tmp;

	if (rio_mport_chk_dev_access(port,
			RIO_ANY_DESTID(port->sys_size), hopcount)) {
		pr_debug("RIO: device access check failed\n");
		return -1;
	}

	if (rio_get_host_deviceid_lock(port, hopcount) == port->host_deviceid) {
		pr_debug("RIO: PE already discovered by this host\n");
		/*
		 * Already discovered by this host. Add it as another
		 * link to the existing device.
		 */
		rio_mport_read_config_32(port, RIO_ANY_DESTID(port->sys_size),
				hopcount, RIO_COMPONENT_TAG_CSR, &regval);

		if (regval) {
			rdev = rio_get_comptag((regval & 0xffff), NULL);

			if (rdev && prev && rio_is_switch(prev)) {
				pr_debug("RIO: redundant path to %s\n",
					 rio_name(rdev));
				prev->rswitch->nextdev[prev_port] = rdev;
			}
		}

		return 0;
	}

	/* Attempt to acquire device lock */
	rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
				  hopcount,
				  RIO_HOST_DID_LOCK_CSR, port->host_deviceid);
	while ((tmp = rio_get_host_deviceid_lock(port, hopcount))
	       < port->host_deviceid) {
		/* Delay a bit */
		mdelay(1);
		/* Attempt to acquire device lock again */
		rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
					  hopcount,
					  RIO_HOST_DID_LOCK_CSR,
					  port->host_deviceid);
	}

	if (rio_get_host_deviceid_lock(port, hopcount) > port->host_deviceid) {
		pr_debug(
		    "RIO: PE locked by a higher priority host...retreating\n");
		return -1;
	}

	/* Setup new RIO device */
	rdev = rio_setup_device(net, port, RIO_ANY_DESTID(port->sys_size),
					hopcount, 1);
	if (rdev) {
		rdev->prev = prev;
		if (prev && rio_is_switch(prev))
			prev->rswitch->nextdev[prev_port] = rdev;
	} else
		return -1;

	if (rio_is_switch(rdev)) {
		int sw_destid;
		int cur_destid;
		int sw_inport;
		u16 destid;
		int port_num;

		sw_inport = RIO_GET_PORT_NUM(rdev->swpinfo);
		rio_route_add_entry(rdev, RIO_GLOBAL_TABLE,
				    port->host_deviceid, sw_inport, 0);
		rdev->rswitch->route_table[port->host_deviceid] = sw_inport;

		destid = rio_destid_first(net);
		while (destid != RIO_INVALID_DESTID && destid < next_destid) {
			if (destid != port->host_deviceid) {
				rio_route_add_entry(rdev, RIO_GLOBAL_TABLE,
						    destid, sw_inport, 0);
				rdev->rswitch->route_table[destid] = sw_inport;
			}
			destid = rio_destid_next(net, destid + 1);
		}
		pr_debug(
		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
		    rio_name(rdev), rdev->vid, rdev->did,
		    RIO_GET_TOTAL_PORTS(rdev->swpinfo));
		sw_destid = next_destid;
		for (port_num = 0;
		     port_num < RIO_GET_TOTAL_PORTS(rdev->swpinfo);
		     port_num++) {
			if (sw_inport == port_num) {
				rio_enable_rx_tx_port(port, 0,
					      RIO_ANY_DESTID(port->sys_size),
					      hopcount, port_num);
				rdev->rswitch->port_ok |= (1 << port_num);
				continue;
			}

			cur_destid = next_destid;

			if (rio_sport_is_active(rdev, port_num)) {
				pr_debug(
				    "RIO: scanning device on port %d\n",
				    port_num);
				rio_enable_rx_tx_port(port, 0,
					      RIO_ANY_DESTID(port->sys_size),
					      hopcount, port_num);
				rdev->rswitch->port_ok |= (1 << port_num);
				rio_route_add_entry(rdev, RIO_GLOBAL_TABLE,
						RIO_ANY_DESTID(port->sys_size),
						port_num, 0);

				if (rio_enum_peer(net, port, hopcount + 1,
						  rdev, port_num) < 0)
					return -1;

				/* Update routing tables */
				destid = rio_destid_next(net, cur_destid + 1);
				if (destid != RIO_INVALID_DESTID) {
					for (destid = cur_destid;
					     destid < next_destid;) {
						if (destid != port->host_deviceid) {
							rio_route_add_entry(rdev,
								    RIO_GLOBAL_TABLE,
								    destid,
								    port_num,
								    0);
							rdev->rswitch->
								route_table[destid] =
								port_num;
						}
						destid = rio_destid_next(net,
								destid + 1);
					}
				}
			} else {
				/* If switch supports Error Management,
				 * set PORT_LOCKOUT bit for unused port
				 */
				if (rdev->em_efptr)
					rio_set_port_lockout(rdev, port_num, 1);

				rdev->rswitch->port_ok &= ~(1 << port_num);
			}
		}

		/* Direct Port-write messages to the enumeratiing host */
		if ((rdev->src_ops & RIO_SRC_OPS_PORT_WRITE) &&
		    (rdev->em_efptr)) {
			rio_write_config_32(rdev,
					rdev->em_efptr + RIO_EM_PW_TGT_DEVID,
					(port->host_deviceid << 16) |
					(port->sys_size << 15));
		}

		rio_init_em(rdev);

		/* Check for empty switch */
		if (next_destid == sw_destid)
			next_destid = rio_destid_alloc(net);

		rdev->destid = sw_destid;
	} else
		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
		    rio_name(rdev), rdev->vid, rdev->did);

	return 0;
}