isp_allocate_handle
reqp->req_handle = isp_allocate_handle(isp, xs, ISP_HANDLE_INITIATOR);
handle = isp_allocate_handle(isp, ccb, ISP_HANDLE_TARGET);
hdl = isp_allocate_handle(isp, resp, ISP_HANDLE_CTRL);
uint32_t isp_allocate_handle(ispsoftc_t *, void *, int);