vt: store a pointer to the keyboard instead of index

This effectively reverts r355935, but is functionally equivalent. We gain no
benefit from storing the index and repeatedly fetching the keyboard with
`kbd_get_keyboard` when we need it. We'll be notified when it's going away
so we can clean up the pointer.

All existing references were trivially converted. Only once instance
actually needed the index.

2 files changed, 24 insertions, 47 deletions

diff --git a/sys/dev/vt/vt.h b/sys/dev/vt/vt.h
index da308cd035c4..ec939f2341cd 100644
--- a/sys/dev/vt/vt.h
+++ b/sys/dev/vt/vt.h
@@ -158,7 +158,7 @@ struct vt_device {
 #define	VDF_QUIET_BELL	0x80	/* Disable bell. */
 #define	VDF_SUSPENDED	0x100	/* Device has been suspended. */
 #define	VDF_DOWNGRADE	0x8000	/* The driver is being downgraded. */
-	int			 vd_keyboard;	/* (G) Keyboard index. */
+	struct keyboard		*vd_keyboard;	/* (G) Keyboard. */
 	unsigned int		 vd_kbstate;	/* (?) Device unit. */
 	unsigned int		 vd_unit;	/* (c) Device unit. */
 	int			 vd_altbrk;	/* (?) Alt break seq. state */
diff --git a/sys/dev/vt/vt_core.c b/sys/dev/vt/vt_core.c
index 78cd5d60b1cf..3d7eecdb1b10 100644
--- a/sys/dev/vt/vt_core.c
+++ b/sys/dev/vt/vt_core.c
@@ -605,8 +605,7 @@ vt_window_switch(struct vt_window *vw)
 
 	/* Restore per-window keyboard mode. */
 	mtx_lock(&Giant);
-	kbd = kbd_get_keyboard(vd->vd_keyboard);
-	if (kbd != NULL) {
+	if ((kbd = vd->vd_keyboard) != NULL) {
 		if (curvw->vw_kbdmode == K_XLATE)
 			vt_save_kbd_state(curvw, kbd);
 
@@ -982,7 +981,7 @@ vt_kbdevent(keyboard_t *kbd, int event, void *arg)
 		break;
 	case KBDIO_UNLOADING:
 		mtx_lock(&Giant);
-		vd->vd_keyboard = -1;
+		vd->vd_keyboard = NULL;
 		kbd_release(kbd, (void *)vd);
 		mtx_unlock(&Giant);
 		return (0);
@@ -1039,19 +1038,14 @@ vt_allocate_keyboard(struct vt_device *vd)
 		DPRINTF(20, "%s: no kbdmux allocated\n", __func__);
 		idx0 = kbd_allocate("*", -1, vd, vt_kbdevent, vd);
 		if (idx0 < 0) {
-			/*
-			 * We don't have a keyboard yet, so we must invalidate
-			 * vd->vd_keyboard so that later keyboard attachment can
-			 * succeed.  Any value >= 0 can accidentally match a
-			 * keyboard.
-			 */
-			vd->vd_keyboard = -1;
 			DPRINTF(10, "%s: No keyboard found.\n", __func__);
 			return (-1);
 		}
+		k0 = kbd_get_keyboard(idx0);
 	}
-	vd->vd_keyboard = idx0;
-	DPRINTF(20, "%s: vd_keyboard = %d\n", __func__, vd->vd_keyboard);
+	vd->vd_keyboard = k0;
+	DPRINTF(20, "%s: vd_keyboard = %d\n", __func__,
+	    vd->vd_keyboard->kb_index);
 
 	if (vd->vd_curwindow == &vt_conswindow) {
 		for (i = 0; i < grabbed; ++i)
@@ -1540,8 +1534,7 @@ vtterm_cngetc(struct terminal *tm)
 	}
 
 	/* Stripped down keyboard handler. */
-	kbd = kbd_get_keyboard(vd->vd_keyboard);
-	if (kbd == NULL)
+	if ((kbd = vd->vd_keyboard) == NULL)
 		return (-1);
 
 	/* Force keyboard input mode to K_XLATE */
@@ -1617,8 +1610,7 @@ vtterm_cngrab(struct terminal *tm)
 	if (!cold)
 		vt_window_switch(vw);
 
-	kbd = kbd_get_keyboard(vd->vd_keyboard);
-	if (kbd == NULL)
+	if ((kbd = vd->vd_keyboard) == NULL)
 		return;
 
 	if (vw->vw_grabbed++ > 0)
@@ -1648,8 +1640,7 @@ vtterm_cnungrab(struct terminal *tm)
 	vw = tm->tm_softc;
 	vd = vw->vw_device;
 
-	kbd = kbd_get_keyboard(vd->vd_keyboard);
-	if (kbd == NULL)
+	if ((kbd = vd->vd_keyboard) == NULL)
 		return;
 
 	if (--vw->vw_grabbed > 0)
@@ -2189,8 +2180,7 @@ skip_thunk:
 		error = 0;
 
 		mtx_lock(&Giant);
-		kbd = kbd_get_keyboard(vd->vd_keyboard);
-		if (kbd != NULL)
+		if ((kbd = vd->vd_keyboard) != NULL)
 			error = kbdd_ioctl(kbd, cmd, data);
 		mtx_unlock(&Giant);
 		if (error == ENOIOCTL) {
@@ -2208,8 +2198,7 @@ skip_thunk:
 
 		if (vw == vd->vd_curwindow) {
 			mtx_lock(&Giant);
-			kbd = kbd_get_keyboard(vd->vd_keyboard);
-			if (kbd != NULL)
+			if ((kbd = vd->vd_keyboard) != NULL)
 				error = vt_save_kbd_state(vw, kbd);
 			mtx_unlock(&Giant);
 
@@ -2234,8 +2223,7 @@ skip_thunk:
 		error = 0;
 		if (vw == vd->vd_curwindow) {
 			mtx_lock(&Giant);
-			kbd = kbd_get_keyboard(vd->vd_keyboard);
-			if (kbd != NULL)
+			if ((kbd = vd->vd_keyboard) != NULL)
 				error = vt_update_kbd_state(vw, kbd);
 			mtx_unlock(&Giant);
 		}
@@ -2247,8 +2235,7 @@ skip_thunk:
 
 		if (vw == vd->vd_curwindow) {
 			mtx_lock(&Giant);
-			kbd = kbd_get_keyboard(vd->vd_keyboard);
-			if (kbd != NULL)
+			if ((kbd = vd->vd_keyboard) != NULL)
 				error = vt_save_kbd_leds(vw, kbd);
 			mtx_unlock(&Giant);
 
@@ -2273,8 +2260,7 @@ skip_thunk:
 		error = 0;
 		if (vw == vd->vd_curwindow) {
 			mtx_lock(&Giant);
-			kbd = kbd_get_keyboard(vd->vd_keyboard);
-			if (kbd != NULL)
+			if ((kbd = vd->vd_keyboard) != NULL)
 				error = vt_update_kbd_leds(vw, kbd);
 			mtx_unlock(&Giant);
 		}
@@ -2290,8 +2276,7 @@ skip_thunk:
 
 		if (vw == vd->vd_curwindow) {
 			mtx_lock(&Giant);
-			kbd = kbd_get_keyboard(vd->vd_keyboard);
-			if (kbd != NULL)
+			if ((kbd = vd->vd_keyboard) != NULL)
 				error = vt_save_kbd_mode(vw, kbd);
 			mtx_unlock(&Giant);
 
@@ -2316,8 +2301,7 @@ skip_thunk:
 			error = 0;
 			if (vw == vd->vd_curwindow) {
 				mtx_lock(&Giant);
-				kbd = kbd_get_keyboard(vd->vd_keyboard);
-				if (kbd != NULL)
+				if ((kbd = vd->vd_keyboard) != NULL)
 					error = vt_update_kbd_mode(vw, kbd);
 				mtx_unlock(&Giant);
 			}
@@ -2362,8 +2346,7 @@ skip_thunk:
 
 		if (vw == vd->vd_curwindow) {
 			mtx_lock(&Giant);
-			kbd = kbd_get_keyboard(vd->vd_keyboard);
-			if (kbd != NULL)
+			if ((kbd = vd->vd_keyboard) != NULL)
 				vt_save_kbd_state(vw, kbd);
 			mtx_unlock(&Giant);
 		}
@@ -2482,7 +2465,8 @@ skip_thunk:
 	case CONS_SETKBD:	/* set the new keyboard */
 		mtx_lock(&Giant);
 		error = 0;
-		if (vd->vd_keyboard != *(int *)data) {
+		if (vd->vd_keyboard == NULL ||
+		    vd->vd_keyboard->kb_index != *(int *)data) {
 			kbd = kbd_get_keyboard(*(int *)data);
 			if (kbd == NULL) {
 				mtx_unlock(&Giant);
@@ -2491,13 +2475,11 @@ skip_thunk:
 			i = kbd_allocate(kbd->kb_name, kbd->kb_unit,
 			    (void *)vd, vt_kbdevent, vd);
 			if (i >= 0) {
-				if (vd->vd_keyboard != -1) {
-					kbd = kbd_get_keyboard(vd->vd_keyboard);
+				if ((kbd = vd->vd_keyboard) != NULL) {
 					vt_save_kbd_state(vd->vd_curwindow, kbd);
 					kbd_release(kbd, (void *)vd);
 				}
-				kbd = kbd_get_keyboard(i);
-				vd->vd_keyboard = i;
+				kbd = vd->vd_keyboard = kbd_get_keyboard(i);
 
 				vt_update_kbd_mode(vd->vd_curwindow, kbd);
 				vt_update_kbd_state(vd->vd_curwindow, kbd);
@@ -2510,16 +2492,11 @@ skip_thunk:
 	case CONS_RELKBD:	/* release the current keyboard */
 		mtx_lock(&Giant);
 		error = 0;
-		if (vd->vd_keyboard != -1) {
-			kbd = kbd_get_keyboard(vd->vd_keyboard);
-			if (kbd == NULL) {
-				mtx_unlock(&Giant);
-				return (EINVAL);
-			}
+		if ((kbd = vd->vd_keyboard) != NULL) {
 			vt_save_kbd_state(vd->vd_curwindow, kbd);
 			error = kbd_release(kbd, (void *)vd);
 			if (error == 0) {
-				vd->vd_keyboard = -1;
+				vd->vd_keyboard = NULL;
 			}
 		}
 		mtx_unlock(&Giant);