int tb_path_activate()

in path.c [484:569]
72 lines of code
11 McCabe index (conditional complexity)

int tb_path_activate(struct tb_path *path)
{
	int i, res;
	enum tb_path_port out_mask, in_mask;
	if (path->activated) {
		tb_WARN(path->tb, "trying to activate already activated path\n");
		return -EINVAL;
	}

	tb_dbg(path->tb,
	       "activating %s path from %llx:%u to %llx:%u\n",
	       path->name, tb_route(path->hops[0].in_port->sw),
	       path->hops[0].in_port->port,
	       tb_route(path->hops[path->path_length - 1].out_port->sw),
	       path->hops[path->path_length - 1].out_port->port);

	/* Clear counters. */
	for (i = path->path_length - 1; i >= 0; i--) {
		if (path->hops[i].in_counter_index == -1)
			continue;
		res = tb_port_clear_counter(path->hops[i].in_port,
					    path->hops[i].in_counter_index);
		if (res)
			goto err;
	}

	/* Add non flow controlled credits. */
	for (i = path->path_length - 1; i >= 0; i--) {
		res = tb_port_add_nfc_credits(path->hops[i].in_port,
					      path->hops[i].nfc_credits);
		if (res) {
			__tb_path_deallocate_nfc(path, i);
			goto err;
		}
	}

	/* Activate hops. */
	for (i = path->path_length - 1; i >= 0; i--) {
		struct tb_regs_hop hop = { 0 };

		/* If it is left active deactivate it first */
		__tb_path_deactivate_hop(path->hops[i].in_port,
				path->hops[i].in_hop_index, path->clear_fc);

		/* dword 0 */
		hop.next_hop = path->hops[i].next_hop_index;
		hop.out_port = path->hops[i].out_port->port;
		hop.initial_credits = path->hops[i].initial_credits;
		hop.unknown1 = 0;
		hop.enable = 1;

		/* dword 1 */
		out_mask = (i == path->path_length - 1) ?
				TB_PATH_DESTINATION : TB_PATH_INTERNAL;
		in_mask = (i == 0) ? TB_PATH_SOURCE : TB_PATH_INTERNAL;
		hop.weight = path->weight;
		hop.unknown2 = 0;
		hop.priority = path->priority;
		hop.drop_packages = path->drop_packages;
		hop.counter = path->hops[i].in_counter_index;
		hop.counter_enable = path->hops[i].in_counter_index != -1;
		hop.ingress_fc = path->ingress_fc_enable & in_mask;
		hop.egress_fc = path->egress_fc_enable & out_mask;
		hop.ingress_shared_buffer = path->ingress_shared_buffer
					    & in_mask;
		hop.egress_shared_buffer = path->egress_shared_buffer
					    & out_mask;
		hop.unknown3 = 0;

		tb_port_dbg(path->hops[i].in_port, "Writing hop %d\n", i);
		tb_dump_hop(&path->hops[i], &hop);
		res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
				    2 * path->hops[i].in_hop_index, 2);
		if (res) {
			__tb_path_deactivate_hops(path, i);
			__tb_path_deallocate_nfc(path, 0);
			goto err;
		}
	}
	path->activated = true;
	tb_dbg(path->tb, "path activation complete\n");
	return 0;
err:
	tb_WARN(path->tb, "path activation failed\n");
	return res;
}