isp_action
static void isp_action(struct cam_sim *, union ccb *);
sim = cam_sim_alloc(isp_action, isp_poll, "isp", isp, device_get_unit(isp->isp_dev), &isp->isp_osinfo.lock, isp->isp_maxcmds, isp->isp_maxcmds, devq);