diff --git a/sys/dev/cfe/cfe_console.c b/sys/dev/cfe/cfe_console.c
index b40567d4f73a..2c38096859f2 100644
--- a/sys/dev/cfe/cfe_console.c
+++ b/sys/dev/cfe/cfe_console.c
@@ -89,7 +89,7 @@ cn_drvinit(void *unused)
 
 	if (cfe_consdev.cn_pri != CN_DEAD &&
 	    cfe_consdev.cn_name[0] != '\0') {
-		tp = tty_alloc(&cfe_ttydevsw, NULL, NULL);
+		tp = tty_alloc(&cfe_ttydevsw, NULL);
 		tty_makedev(tp, NULL, "%s", output);
 		tty_makealias(tp, "cfecons");
 	}
diff --git a/sys/dev/dcons/dcons_os.c b/sys/dev/dcons/dcons_os.c
index 49967eb5018a..3b98cdd255f7 100644
--- a/sys/dev/dcons/dcons_os.c
+++ b/sys/dev/dcons/dcons_os.c
@@ -357,7 +357,7 @@ dcons_attach_port(int port, char *name, int flags)
 	struct tty *tp;
 
 	dc = &sc[port];
-	tp = tty_alloc(&dcons_ttydevsw, dc, NULL);
+	tp = tty_alloc(&dcons_ttydevsw, dc);
 	dc->flags = flags;
 	dc->tty   = tp;
 	tty_init_console(tp, 0);
diff --git a/sys/dev/nmdm/nmdm.c b/sys/dev/nmdm/nmdm.c
index 2c41290297bf..d2fe8777b94a 100644
--- a/sys/dev/nmdm/nmdm.c
+++ b/sys/dev/nmdm/nmdm.c
@@ -117,11 +117,11 @@ nmdm_alloc(unsigned long unit)
 	callout_init(&ns->ns_part2.np_callout, CALLOUT_MPSAFE);
 
 	/* Create device nodes. */
-	tp = ns->ns_part1.np_tty = tty_alloc(&nmdm_class, &ns->ns_part1,
+	tp = ns->ns_part1.np_tty = tty_alloc_mutex(&nmdm_class, &ns->ns_part1,
 	    &ns->ns_mtx);
 	tty_makedev(tp, NULL, "nmdm%luA", unit);
 
-	tp = ns->ns_part2.np_tty = tty_alloc(&nmdm_class, &ns->ns_part2,
+	tp = ns->ns_part2.np_tty = tty_alloc_mutex(&nmdm_class, &ns->ns_part2,
 	    &ns->ns_mtx);
 	tty_makedev(tp, NULL, "nmdm%luB", unit);
 
diff --git a/sys/dev/ofw/ofw_console.c b/sys/dev/ofw/ofw_console.c
index 493bb7836664..fd280c97fc89 100644
--- a/sys/dev/ofw/ofw_console.c
+++ b/sys/dev/ofw/ofw_console.c
@@ -95,7 +95,7 @@ cn_drvinit(void *unused)
 		 * XXX: This is a hack and it may result in two /dev/ttya
 		 * XXX: devices on platforms where the sab driver works.
 		 */
-		tp = tty_alloc(&ofw_ttydevsw, NULL, NULL);
+		tp = tty_alloc(&ofw_ttydevsw, NULL);
 		tty_makedev(tp, NULL, "%s", output);
 		tty_makealias(tp, "ofwcons");
 	}
diff --git a/sys/dev/rp/rp.c b/sys/dev/rp/rp.c
index 690e2218de1a..520ca80f9301 100644
--- a/sys/dev/rp/rp.c
+++ b/sys/dev/rp/rp.c
@@ -774,7 +774,7 @@ rp_attachcommon(CONTROLLER_T *ctlp, int num_aiops, int num_ports)
 	for(aiop=0; aiop < num_aiops; aiop++) {
 		num_chan = sGetAiopNumChan(ctlp, aiop);
 		for(chan=0; chan < num_chan; chan++, port++, rp++) {
-			rp->rp_tty = tp = tty_alloc(&rp_tty_class, rp, NULL);
+			rp->rp_tty = tp = tty_alloc(&rp_tty_class, rp);
 			rp->rp_port = port;
 			rp->rp_ctlp = ctlp;
 			rp->rp_unit = unit;
diff --git a/sys/dev/si/si.c b/sys/dev/si/si.c
index ded079c7ac22..416771cf1c7a 100644
--- a/sys/dev/si/si.c
+++ b/sys/dev/si/si.c
@@ -584,7 +584,7 @@ siattach(device_t dev)
 			sprintf(pp->sp_name, "si%r%r", unit,
 			    (int)(pp - sc->sc_ports));
 #endif
-			tp = pp->sp_tty = tty_alloc(&si_tty_class, pp, &Giant);
+			tp = pp->sp_tty = tty_alloc_mutex(&si_tty_class, pp, &Giant);
 			tty_makedev(tp, NULL, "A%r%r", unit, (int)(pp - sc->sc_ports));
 		}
 try_next2:
diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index 0ba7d7dcac89..653ff08274a9 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -334,7 +334,7 @@ sc_alloc_tty(int index, int devnum)
 	stc = malloc(sizeof(struct sc_ttysoftc), M_DEVBUF, M_WAITOK);
 	stc->st_index = index;
 	stc->st_stat = NULL;
-	tp = tty_alloc(&sc_ttydevsw, stc, &Giant);
+	tp = tty_alloc_mutex(&sc_ttydevsw, stc, &Giant);
 
 	/* Create device node. */
 	tty_makedev(tp, NULL, "v%r", devnum);
diff --git a/sys/dev/syscons/sysmouse.c b/sys/dev/syscons/sysmouse.c
index 67c5079f50cf..4e787efbbe51 100644
--- a/sys/dev/syscons/sysmouse.c
+++ b/sys/dev/syscons/sysmouse.c
@@ -164,7 +164,7 @@ static struct ttydevsw smdev_ttydevsw = {
 static void
 sm_attach_mouse(void *unused)
 {
-	sysmouse_tty = tty_alloc(&smdev_ttydevsw, NULL, NULL);
+	sysmouse_tty = tty_alloc(&smdev_ttydevsw, NULL);
 	tty_makedev(sysmouse_tty, NULL, "sysmouse");
 }
 
diff --git a/sys/dev/uart/uart_tty.c b/sys/dev/uart/uart_tty.c
index 5fcf98e24316..cb77f65ecae9 100644
--- a/sys/dev/uart/uart_tty.c
+++ b/sys/dev/uart/uart_tty.c
@@ -356,7 +356,7 @@ uart_tty_attach(struct uart_softc *sc)
 	struct tty *tp;
 	int unit;
 
-	sc->sc_u.u_tty.tp = tp = tty_alloc(&uart_tty_class, sc, NULL);
+	sc->sc_u.u_tty.tp = tp = tty_alloc(&uart_tty_class, sc);
 
 	unit = device_get_unit(sc->sc_dev);
 
diff --git a/sys/dev/usb/serial/usb_serial.c b/sys/dev/usb/serial/usb_serial.c
index b5222708a7a6..fc9a6fd10a63 100644
--- a/sys/dev/usb/serial/usb_serial.c
+++ b/sys/dev/usb/serial/usb_serial.c
@@ -293,7 +293,7 @@ usb2_com_attach_tty(struct ucom_softc *sc, uint32_t sub_units)
 	int error = 0;
 	char buf[32];			/* temporary TTY device name buffer */
 
-	tp = tty_alloc(&usb2_com_class, sc, sc->sc_mtx);
+	tp = tty_alloc_mutex(&usb2_com_class, sc, sc->sc_mtx);
 	if (tp == NULL) {
 		error = ENOMEM;
 		goto done;
diff --git a/sys/dev/xen/console/console.c b/sys/dev/xen/console/console.c
index 9b376b52fbfb..68bb0aecf859 100644
--- a/sys/dev/xen/console/console.c
+++ b/sys/dev/xen/console/console.c
@@ -230,7 +230,7 @@ xc_attach(device_t dev)
 		xc_consdev.cn_putc = xccnputc_dom0;
 	} 
 
-	xccons = tty_alloc(&xc_ttydevsw, NULL, NULL);
+	xccons = tty_alloc(&xc_ttydevsw, NULL);
 	tty_makedev(xccons, NULL, "xc%r", 0);
 
 	callout_init(&xc_callout, 0);
diff --git a/sys/ia64/ia64/ssc.c b/sys/ia64/ia64/ssc.c
index 04144c5789c9..ff810fc87f2b 100644
--- a/sys/ia64/ia64/ssc.c
+++ b/sys/ia64/ia64/ssc.c
@@ -106,7 +106,7 @@ ssc_cnattach(void *arg)
 {
 	struct tty *tp;
 
-	tp = tty_alloc(&ssc_class, NULL, NULL);
+	tp = tty_alloc(&ssc_class, NULL);
 	tty_makedev(tp, NULL, "ssccons");
 }
 
diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index 9b3c57162a13..ba7e6ba191aa 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -885,7 +885,14 @@ ttydevsw_deffree(void *softc)
  */
 
 struct tty *
-tty_alloc(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
+tty_alloc(struct ttydevsw *tsw, void *sc)
+{
+
+	return (tty_alloc_mutex(tsw, sc, NULL));
+}
+
+struct tty *
+tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
 {
 	struct tty *tp;
 
diff --git a/sys/kern/tty_pts.c b/sys/kern/tty_pts.c
index 67704b8eaa9f..27e481e650be 100644
--- a/sys/kern/tty_pts.c
+++ b/sys/kern/tty_pts.c
@@ -741,7 +741,7 @@ pts_alloc(int fflags, struct thread *td, struct file *fp)
 	psc->pts_uidinfo = uid;
 	uihold(uid);
 
-	tp = tty_alloc(&pts_class, psc, NULL);
+	tp = tty_alloc(&pts_class, psc);
 	knlist_init(&psc->pts_inpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
 	knlist_init(&psc->pts_outpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
 
@@ -781,7 +781,7 @@ pts_alloc_external(int fflags, struct thread *td, struct file *fp,
 	psc->pts_uidinfo = uid;
 	uihold(uid);
 
-	tp = tty_alloc(&pts_class, psc, NULL);
+	tp = tty_alloc(&pts_class, psc);
 	knlist_init(&psc->pts_inpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
 	knlist_init(&psc->pts_outpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
 
diff --git a/sys/sun4v/sun4v/hvcons.c b/sys/sun4v/sun4v/hvcons.c
index 314d15cdde4c..60f830b08c7f 100644
--- a/sys/sun4v/sun4v/hvcons.c
+++ b/sys/sun4v/sun4v/hvcons.c
@@ -327,7 +327,7 @@ hvcn_dev_attach(device_t dev)
 	    hvcn_consdev.cn_name[0] == '\0') 
 		return (ENXIO);
 
-	tp = tty_alloc(&hvcn_class, NULL, NULL);
+	tp = tty_alloc(&hvcn_class, NULL);
 	tty_makedev(tp, NULL, "v%r", 1);
 	tty_makealias(tp, "hvcn");
 	
diff --git a/sys/sys/tty.h b/sys/sys/tty.h
index 893509395e44..8d7daca49d21 100644
--- a/sys/sys/tty.h
+++ b/sys/sys/tty.h
@@ -152,7 +152,8 @@ struct xtty {
 #ifdef _KERNEL
 
 /* Allocation and deallocation. */
-struct tty *tty_alloc(struct ttydevsw *tsw, void *softc, struct mtx *mtx);
+struct tty *tty_alloc(struct ttydevsw *tsw, void *softc);
+struct tty *tty_alloc_mutex(struct ttydevsw *tsw, void *softc, struct mtx *mtx);
 void	tty_rel_pgrp(struct tty *tp, struct pgrp *pgrp);
 void	tty_rel_sess(struct tty *tp, struct session *sess);
 void	tty_rel_gone(struct tty *tp);