Adding upstream version 6.9.7.upstream/6.9.7

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 871 insertions, 723 deletions

diff --git a/drivers/tty/vt/Makefile b/drivers/tty/vt/Makefile
index b3dfe9d571..2c8ce8b592 100644
--- a/drivers/tty/vt/Makefile
+++ b/drivers/tty/vt/Makefile
@@ -5,9 +5,9 @@
 FONTMAPFILE = cp437.uni
 
 obj-$(CONFIG_VT)			+= vt_ioctl.o vc_screen.o \
-					   selection.o keyboard.o
+					   selection.o keyboard.o \
+					   vt.o defkeymap.o
 obj-$(CONFIG_CONSOLE_TRANSLATIONS)	+= consolemap.o consolemap_deftbl.o
-obj-$(CONFIG_HW_CONSOLE)		+= vt.o defkeymap.o
 
 # Files generated that shall be removed upon make clean
 clean-files := consolemap_deftbl.c defkeymap.c
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index 8967c3a0d9..564341f1a7 100644
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -7,7 +7,7 @@
  *     'int set_selection_kernel(struct tiocl_selection *, struct tty_struct *)'
  *     'void clear_selection(void)'
  *     'int paste_selection(struct tty_struct *)'
- *     'int sel_loadlut(char __user *)'
+ *     'int sel_loadlut(u32 __user *)'
  *
  * Now that /dev/vcs exists, most of this can disappear again.
  */
@@ -73,10 +73,12 @@ sel_pos(int n, bool unicode)
 }
 
 /**
- *	clear_selection		-	remove current selection
+ * clear_selection - remove current selection
  *
- *	Remove the current selection highlight, if any from the console
- *	holding the selection. The caller must hold the console lock.
+ * Remove the current selection highlight, if any from the console holding the
+ * selection.
+ *
+ * Locking: The caller must hold the console lock.
  */
 void clear_selection(void)
 {
@@ -88,7 +90,7 @@ void clear_selection(void)
 }
 EXPORT_SYMBOL_GPL(clear_selection);
 
-bool vc_is_sel(struct vc_data *vc)
+bool vc_is_sel(const struct vc_data *vc)
 {
 	return vc == vc_sel.cons;
 }
@@ -110,18 +112,25 @@ static inline int inword(const u32 c)
 }
 
 /**
- *	sel_loadlut()		-	load the LUT table
- *	@p: user table
+ * sel_loadlut() - load the LUT table
+ * @lut: user table
+ *
+ * Load the LUT table from user space. Make a temporary copy so a partial
+ * update doesn't make a mess.
  *
- *	Load the LUT table from user space. The caller must hold the console
- *	lock. Make a temporary copy so a partial update doesn't make a mess.
+ * Locking: The console lock is acquired.
  */
-int sel_loadlut(char __user *p)
+int sel_loadlut(u32 __user *lut)
 {
 	u32 tmplut[ARRAY_SIZE(inwordLut)];
-	if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
+
+	if (copy_from_user(tmplut, lut, sizeof(inwordLut)))
 		return -EFAULT;
+
+	console_lock();
 	memcpy(inwordLut, tmplut, sizeof(inwordLut));
+	console_unlock();
+
 	return 0;
 }
 
@@ -166,14 +175,14 @@ static int store_utf8(u32 c, char *p)
 }
 
 /**
- *	set_selection_user	-	set the current selection.
- *	@sel: user selection info
- *	@tty: the console tty
+ * set_selection_user - set the current selection.
+ * @sel: user selection info
+ * @tty: the console tty
  *
- *	Invoked by the ioctl handle for the vt layer.
+ * Invoked by the ioctl handle for the vt layer.
  *
- *	The entire selection process is managed under the console_lock. It's
- *	 a lot under the lock but its hardly a performance path
+ * Locking: The entire selection process is managed under the console_lock.
+ * It's a lot under the lock but its hardly a performance path.
  */
 int set_selection_user(const struct tiocl_selection __user *sel,
 		       struct tty_struct *tty)
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 52e6ca1ba2..cd87e3d129 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -145,7 +145,7 @@ static void gotoxy(struct vc_data *vc, int new_x, int new_y);
 static void save_cur(struct vc_data *vc);
 static void reset_terminal(struct vc_data *vc, int do_clear);
 static void con_flush_chars(struct tty_struct *tty);
-static int set_vesa_blanking(char __user *p);
+static int set_vesa_blanking(u8 __user *mode);
 static void set_cursor(struct vc_data *vc);
 static void hide_cursor(struct vc_data *vc);
 static void console_callback(struct work_struct *ignored);
@@ -175,7 +175,7 @@ int do_poke_blanked_console;
 int console_blanked;
 EXPORT_SYMBOL(console_blanked);
 
-static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
+static enum vesa_blank_mode vesa_blank_mode;
 static int vesa_off_interval;
 static int blankinterval;
 core_param(consoleblank, blankinterval, int, 0444);
@@ -286,18 +286,20 @@ static inline bool con_should_update(const struct vc_data *vc)
 	return con_is_visible(vc) && !console_blanked;
 }
 
-static inline unsigned short *screenpos(const struct vc_data *vc, int offset,
-		bool viewed)
+static inline u16 *screenpos(const struct vc_data *vc, unsigned int offset,
+			     bool viewed)
 {
-	unsigned short *p;
-	
-	if (!viewed)
-		p = (unsigned short *)(vc->vc_origin + offset);
-	else if (!vc->vc_sw->con_screen_pos)
-		p = (unsigned short *)(vc->vc_visible_origin + offset);
+	unsigned long origin = viewed ? vc->vc_visible_origin : vc->vc_origin;
+
+	return (u16 *)(origin + offset);
+}
+
+static void con_putc(struct vc_data *vc, u16 ca, unsigned int y, unsigned int x)
+{
+	if (vc->vc_sw->con_putc)
+		vc->vc_sw->con_putc(vc, ca, y, x);
 	else
-		p = vc->vc_sw->con_screen_pos(vc, offset);
-	return p;
+		vc->vc_sw->con_putcs(vc, &ca, 1, y, x);
 }
 
 /* Called  from the keyboard irq path.. */
@@ -591,18 +593,12 @@ static void con_scroll(struct vc_data *vc, unsigned int top,
 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 {
 	unsigned int xx, yy, offset;
-	u16 *p;
+	u16 *p = (u16 *)start;
+
+	offset = (start - vc->vc_origin) / 2;
+	xx = offset % vc->vc_cols;
+	yy = offset / vc->vc_cols;
 
-	p = (u16 *) start;
-	if (!vc->vc_sw->con_getxy) {
-		offset = (start - vc->vc_origin) / 2;
-		xx = offset % vc->vc_cols;
-		yy = offset / vc->vc_cols;
-	} else {
-		int nxx, nyy;
-		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
-		xx = nxx; yy = nyy;
-	}
 	for(;;) {
 		u16 attrib = scr_readw(p) & 0xff00;
 		int startx = xx;
@@ -625,10 +621,6 @@ static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 			break;
 		xx = 0;
 		yy++;
-		if (vc->vc_sw->con_getxy) {
-			p = (u16 *)start;
-			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
-		}
 	}
 }
 
@@ -703,7 +695,7 @@ static void update_attr(struct vc_data *vc)
 /* Note: inverting the screen twice should revert to the original state */
 void invert_screen(struct vc_data *vc, int offset, int count, bool viewed)
 {
-	unsigned short *p;
+	u16 *p;
 
 	WARN_CONSOLE_UNLOCKED();
 
@@ -762,7 +754,7 @@ void complement_pos(struct vc_data *vc, int offset)
 	    old_offset < vc->vc_screenbuf_size) {
 		scr_writew(old, screenpos(vc, old_offset, true));
 		if (con_should_update(vc))
-			vc->vc_sw->con_putc(vc, old, oldy, oldx);
+			con_putc(vc, old, oldy, oldx);
 		notify_update(vc);
 	}
 
@@ -771,15 +763,14 @@ void complement_pos(struct vc_data *vc, int offset)
 	if (offset != -1 && offset >= 0 &&
 	    offset < vc->vc_screenbuf_size) {
 		unsigned short new;
-		unsigned short *p;
-		p = screenpos(vc, offset, true);
+		u16 *p = screenpos(vc, offset, true);
 		old = scr_readw(p);
 		new = old ^ vc->vc_complement_mask;
 		scr_writew(new, p);
 		if (con_should_update(vc)) {
 			oldx = (offset >> 1) % vc->vc_cols;
 			oldy = (offset >> 1) / vc->vc_cols;
-			vc->vc_sw->con_putc(vc, new, oldy, oldx);
+			con_putc(vc, new, oldy, oldx);
 		}
 		notify_update(vc);
 	}
@@ -833,7 +824,7 @@ static void add_softcursor(struct vc_data *vc)
 		i ^= CUR_FG;
 	scr_writew(i, (u16 *)vc->vc_pos);
 	if (con_should_update(vc))
-		vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
+		con_putc(vc, i, vc->state.y, vc->state.x);
 }
 
 static void hide_softcursor(struct vc_data *vc)
@@ -841,8 +832,8 @@ static void hide_softcursor(struct vc_data *vc)
 	if (softcursor_original != -1) {
 		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
 		if (con_should_update(vc))
-			vc->vc_sw->con_putc(vc, softcursor_original,
-					vc->state.y, vc->state.x);
+			con_putc(vc, softcursor_original, vc->state.y,
+				 vc->state.x);
 		softcursor_original = -1;
 	}
 }
@@ -852,7 +843,7 @@ static void hide_cursor(struct vc_data *vc)
 	if (vc_is_sel(vc))
 		clear_selection();
 
-	vc->vc_sw->con_cursor(vc, CM_ERASE);
+	vc->vc_sw->con_cursor(vc, false);
 	hide_softcursor(vc);
 }
 
@@ -865,7 +856,7 @@ static void set_cursor(struct vc_data *vc)
 			clear_selection();
 		add_softcursor(vc);
 		if (CUR_SIZE(vc->vc_cursor_type) != CUR_NONE)
-			vc->vc_sw->con_cursor(vc, CM_DRAW);
+			vc->vc_sw->con_cursor(vc, true);
 	} else
 		hide_cursor(vc);
 }
@@ -897,21 +888,18 @@ static void flush_scrollback(struct vc_data *vc)
 	WARN_CONSOLE_UNLOCKED();
 
 	set_origin(vc);
-	if (vc->vc_sw->con_flush_scrollback) {
-		vc->vc_sw->con_flush_scrollback(vc);
-	} else if (con_is_visible(vc)) {
-		/*
-		 * When no con_flush_scrollback method is provided then the
-		 * legacy way for flushing the scrollback buffer is to use
-		 * a side effect of the con_switch method. We do it only on
-		 * the foreground console as background consoles have no
-		 * scrollback buffers in that case and we obviously don't
-		 * want to switch to them.
-		 */
-		hide_cursor(vc);
-		vc->vc_sw->con_switch(vc);
-		set_cursor(vc);
-	}
+	if (!con_is_visible(vc))
+		return;
+
+	/*
+	 * The legacy way for flushing the scrollback buffer is to use a side
+	 * effect of the con_switch method. We do it only on the foreground
+	 * console as background consoles have no scrollback buffers in that
+	 * case and we obviously don't want to switch to them.
+	 */
+	hide_cursor(vc);
+	vc->vc_sw->con_switch(vc);
+	set_cursor(vc);
 }
 
 /*
@@ -962,7 +950,7 @@ void redraw_screen(struct vc_data *vc, int is_switch)
 	}
 
 	if (redraw) {
-		int update;
+		bool update;
 		int old_was_color = vc->vc_can_do_color;
 
 		set_origin(vc);
@@ -999,7 +987,7 @@ int vc_cons_allocated(unsigned int i)
 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
 }
 
-static void visual_init(struct vc_data *vc, int num, int init)
+static void visual_init(struct vc_data *vc, int num, bool init)
 {
 	/* ++Geert: vc->vc_sw->con_init determines console size */
 	if (vc->vc_sw)
@@ -1083,7 +1071,7 @@ int vc_allocate(unsigned int currcons)	/* return 0 on success */
 	vc->port.ops = &vc_port_ops;
 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
 
-	visual_init(vc, currcons, 1);
+	visual_init(vc, currcons, true);
 
 	if (!*vc->uni_pagedict_loc)
 		con_set_default_unimap(vc);
@@ -1115,51 +1103,44 @@ err_free:
 }
 
 static inline int resize_screen(struct vc_data *vc, int width, int height,
-				int user)
+				bool from_user)
 {
 	/* Resizes the resolution of the display adapater */
 	int err = 0;
 
 	if (vc->vc_sw->con_resize)
-		err = vc->vc_sw->con_resize(vc, width, height, user);
+		err = vc->vc_sw->con_resize(vc, width, height, from_user);
 
 	return err;
 }
 
 /**
- *	vc_do_resize	-	resizing method for the tty
- *	@tty: tty being resized
- *	@vc: virtual console private data
- *	@cols: columns
- *	@lines: lines
+ * vc_do_resize - resizing method for the tty
+ * @tty: tty being resized
+ * @vc: virtual console private data
+ * @cols: columns
+ * @lines: lines
+ * @from_user: invoked by a user?
  *
- *	Resize a virtual console, clipping according to the actual constraints.
- *	If the caller passes a tty structure then update the termios winsize
- *	information and perform any necessary signal handling.
+ * Resize a virtual console, clipping according to the actual constraints. If
+ * the caller passes a tty structure then update the termios winsize
+ * information and perform any necessary signal handling.
  *
- *	Caller must hold the console semaphore. Takes the termios rwsem and
- *	ctrl.lock of the tty IFF a tty is passed.
+ * Locking: Caller must hold the console semaphore. Takes the termios rwsem and
+ * ctrl.lock of the tty IFF a tty is passed.
  */
-
 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
-				unsigned int cols, unsigned int lines)
+			unsigned int cols, unsigned int lines, bool from_user)
 {
 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
 	unsigned long end;
 	unsigned int old_rows, old_row_size, first_copied_row;
 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
-	unsigned int user;
 	unsigned short *oldscreen, *newscreen;
 	u32 **new_uniscr = NULL;
 
 	WARN_CONSOLE_UNLOCKED();
 
-	if (!vc)
-		return -ENXIO;
-
-	user = vc->vc_resize_user;
-	vc->vc_resize_user = 0;
-
 	if (cols > VC_MAXCOL || lines > VC_MAXROW)
 		return -EINVAL;
 
@@ -1185,7 +1166,7 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
 		 * to deal with possible errors from the code below, we call
 		 * the resize_screen here as well.
 		 */
-		return resize_screen(vc, new_cols, new_rows, user);
+		return resize_screen(vc, new_cols, new_rows, from_user);
 	}
 
 	if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
@@ -1208,7 +1189,7 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
 	old_rows = vc->vc_rows;
 	old_row_size = vc->vc_size_row;
 
-	err = resize_screen(vc, new_cols, new_rows, user);
+	err = resize_screen(vc, new_cols, new_rows, from_user);
 	if (err) {
 		kfree(newscreen);
 		vc_uniscr_free(new_uniscr);
@@ -1295,34 +1276,35 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
 }
 
 /**
- *	vc_resize		-	resize a VT
- *	@vc: virtual console
- *	@cols: columns
- *	@rows: rows
+ * __vc_resize - resize a VT
+ * @vc: virtual console
+ * @cols: columns
+ * @rows: rows
+ * @from_user: invoked by a user?
  *
- *	Resize a virtual console as seen from the console end of things. We
- *	use the common vc_do_resize methods to update the structures. The
- *	caller must hold the console sem to protect console internals and
- *	vc->port.tty
+ * Resize a virtual console as seen from the console end of things. We use the
+ * common vc_do_resize() method to update the structures.
+ *
+ * Locking: The caller must hold the console sem to protect console internals
+ * and @vc->port.tty.
  */
-
-int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
+int __vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows,
+		bool from_user)
 {
-	return vc_do_resize(vc->port.tty, vc, cols, rows);
+	return vc_do_resize(vc->port.tty, vc, cols, rows, from_user);
 }
-EXPORT_SYMBOL(vc_resize);
+EXPORT_SYMBOL(__vc_resize);
 
 /**
- *	vt_resize		-	resize a VT
- *	@tty: tty to resize
- *	@ws: winsize attributes
+ * vt_resize - resize a VT
+ * @tty: tty to resize
+ * @ws: winsize attributes
  *
- *	Resize a virtual terminal. This is called by the tty layer as we
- *	register our own handler for resizing. The mutual helper does all
- *	the actual work.
+ * Resize a virtual terminal. This is called by the tty layer as we register
+ * our own handler for resizing. The mutual helper does all the actual work.
  *
- *	Takes the console sem and the called methods then take the tty
- *	termios_rwsem and the tty ctrl.lock in that order.
+ * Locking: Takes the console sem and the called methods then take the tty
+ * termios_rwsem and the tty ctrl.lock in that order.
  */
 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
 {
@@ -1330,7 +1312,7 @@ static int vt_resize(struct tty_struct *tty, struct winsize *ws)
 	int ret;
 
 	console_lock();
-	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
+	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row, false);
 	console_unlock();
 	return ret;
 }
@@ -1503,36 +1485,43 @@ static inline void del(struct vc_data *vc)
 	/* ignored */
 }
 
-static void csi_J(struct vc_data *vc, int vpar)
+enum CSI_J {
+	CSI_J_CURSOR_TO_END	= 0,
+	CSI_J_START_TO_CURSOR	= 1,
+	CSI_J_VISIBLE		= 2,
+	CSI_J_FULL		= 3,
+};
+
+static void csi_J(struct vc_data *vc, enum CSI_J vpar)
 {
+	unsigned short *start;
 	unsigned int count;
-	unsigned short * start;
 
 	switch (vpar) {
-		case 0:	/* erase from cursor to end of display */
-			vc_uniscr_clear_line(vc, vc->state.x,
-					     vc->vc_cols - vc->state.x);
-			vc_uniscr_clear_lines(vc, vc->state.y + 1,
-					      vc->vc_rows - vc->state.y - 1);
-			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
-			start = (unsigned short *)vc->vc_pos;
-			break;
-		case 1:	/* erase from start to cursor */
-			vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
-			vc_uniscr_clear_lines(vc, 0, vc->state.y);
-			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
-			start = (unsigned short *)vc->vc_origin;
-			break;
-		case 3: /* include scrollback */
-			flush_scrollback(vc);
-			fallthrough;
-		case 2: /* erase whole display */
-			vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
-			count = vc->vc_cols * vc->vc_rows;
-			start = (unsigned short *)vc->vc_origin;
-			break;
-		default:
-			return;
+	case CSI_J_CURSOR_TO_END:
+		vc_uniscr_clear_line(vc, vc->state.x,
+				     vc->vc_cols - vc->state.x);
+		vc_uniscr_clear_lines(vc, vc->state.y + 1,
+				      vc->vc_rows - vc->state.y - 1);
+		count = (vc->vc_scr_end - vc->vc_pos) >> 1;
+		start = (unsigned short *)vc->vc_pos;
+		break;
+	case CSI_J_START_TO_CURSOR:
+		vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
+		vc_uniscr_clear_lines(vc, 0, vc->state.y);
+		count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
+		start = (unsigned short *)vc->vc_origin;
+		break;
+	case CSI_J_FULL:
+		flush_scrollback(vc);
+		fallthrough;
+	case CSI_J_VISIBLE:
+		vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
+		count = vc->vc_cols * vc->vc_rows;
+		start = (unsigned short *)vc->vc_origin;
+		break;
+	default:
+		return;
 	}
 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
 	if (con_should_update(vc))
@@ -1540,27 +1529,33 @@ static void csi_J(struct vc_data *vc, int vpar)
 	vc->vc_need_wrap = 0;
 }
 
-static void csi_K(struct vc_data *vc, int vpar)
+enum {
+	CSI_K_CURSOR_TO_LINEEND		= 0,
+	CSI_K_LINESTART_TO_CURSOR	= 1,
+	CSI_K_LINE			= 2,
+};
+
+static void csi_K(struct vc_data *vc)
 {
 	unsigned int count;
 	unsigned short *start = (unsigned short *)vc->vc_pos;
 	int offset;
 
-	switch (vpar) {
-		case 0:	/* erase from cursor to end of line */
-			offset = 0;
-			count = vc->vc_cols - vc->state.x;
-			break;
-		case 1:	/* erase from start of line to cursor */
-			offset = -vc->state.x;
-			count = vc->state.x + 1;
-			break;
-		case 2: /* erase whole line */
-			offset = -vc->state.x;
-			count = vc->vc_cols;
-			break;
-		default:
-			return;
+	switch (vc->vc_par[0]) {
+	case CSI_K_CURSOR_TO_LINEEND:
+		offset = 0;
+		count = vc->vc_cols - vc->state.x;
+		break;
+	case CSI_K_LINESTART_TO_CURSOR:
+		offset = -vc->state.x;
+		count = vc->state.x + 1;
+		break;
+	case CSI_K_LINE:
+		offset = -vc->state.x;
+		count = vc->vc_cols;
+		break;
+	default:
+		return;
 	}
 	vc_uniscr_clear_line(vc, vc->state.x + offset, count);
 	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
@@ -1569,20 +1564,15 @@ static void csi_K(struct vc_data *vc, int vpar)
 		do_update_region(vc, (unsigned long)(start + offset), count);
 }
 
-/* erase the following vpar positions */
-static void csi_X(struct vc_data *vc, unsigned int vpar)
+/* erase the following count positions */
+static void csi_X(struct vc_data *vc)
 {					  /* not vt100? */
-	unsigned int count;
-
-	if (!vpar)
-		vpar++;
-
-	count = min(vpar, vc->vc_cols - vc->state.x);
+	unsigned int count = clamp(vc->vc_par[0], 1, vc->vc_cols - vc->state.x);
 
 	vc_uniscr_clear_line(vc, vc->state.x, count);
 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
 	if (con_should_update(vc))
-		vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
+		vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, count);
 	vc->vc_need_wrap = 0;
 }
 
@@ -1598,7 +1588,7 @@ static void default_attr(struct vc_data *vc)
 
 struct rgb { u8 r; u8 g; u8 b; };
 
-static void rgb_from_256(int i, struct rgb *c)
+static void rgb_from_256(unsigned int i, struct rgb *c)
 {
 	if (i < 8) {            /* Standard colours. */
 		c->r = i&1 ? 0xaa : 0x00;
@@ -1609,9 +1599,12 @@ static void rgb_from_256(int i, struct rgb *c)
 		c->g = i&2 ? 0xff : 0x55;
 		c->b = i&4 ? 0xff : 0x55;
 	} else if (i < 232) {   /* 6x6x6 colour cube. */
-		c->r = (i - 16) / 36 * 85 / 2;
-		c->g = (i - 16) / 6 % 6 * 85 / 2;
-		c->b = (i - 16) % 6 * 85 / 2;
+		i -= 16;
+		c->b = i % 6 * 255 / 6;
+		i /= 6;
+		c->g = i % 6 * 255 / 6;
+		i /= 6;
+		c->r = i     * 255 / 6;
 	} else                  /* Grayscale ramp. */
 		c->r = c->g = c->b = i * 10 - 2312;
 }
@@ -1681,6 +1674,39 @@ static int vc_t416_color(struct vc_data *vc, int i,
 	return i;
 }
 
+enum {
+	CSI_m_DEFAULT			= 0,
+	CSI_m_BOLD			= 1,
+	CSI_m_HALF_BRIGHT		= 2,
+	CSI_m_ITALIC			= 3,
+	CSI_m_UNDERLINE			= 4,
+	CSI_m_BLINK			= 5,
+	CSI_m_REVERSE			= 7,
+	CSI_m_PRI_FONT			= 10,
+	CSI_m_ALT_FONT1			= 11,
+	CSI_m_ALT_FONT2			= 12,
+	CSI_m_DOUBLE_UNDERLINE		= 21,
+	CSI_m_NORMAL_INTENSITY		= 22,
+	CSI_m_NO_ITALIC			= 23,
+	CSI_m_NO_UNDERLINE		= 24,
+	CSI_m_NO_BLINK			= 25,
+	CSI_m_NO_REVERSE		= 27,
+	CSI_m_FG_COLOR_BEG		= 30,
+	CSI_m_FG_COLOR_END		= 37,
+	CSI_m_FG_COLOR			= 38,
+	CSI_m_DEFAULT_FG_COLOR		= 39,
+	CSI_m_BG_COLOR_BEG		= 40,
+	CSI_m_BG_COLOR_END		= 47,
+	CSI_m_BG_COLOR			= 48,
+	CSI_m_DEFAULT_BG_COLOR		= 49,
+	CSI_m_BRIGHT_FG_COLOR_BEG	= 90,
+	CSI_m_BRIGHT_FG_COLOR_END	= 97,
+	CSI_m_BRIGHT_FG_COLOR_OFF	= CSI_m_BRIGHT_FG_COLOR_BEG - CSI_m_FG_COLOR_BEG,
+	CSI_m_BRIGHT_BG_COLOR_BEG	= 100,
+	CSI_m_BRIGHT_BG_COLOR_END	= 107,
+	CSI_m_BRIGHT_BG_COLOR_OFF	= CSI_m_BRIGHT_BG_COLOR_BEG - CSI_m_BG_COLOR_BEG,
+};
+
 /* console_lock is held */
 static void csi_m(struct vc_data *vc)
 {
@@ -1688,33 +1714,33 @@ static void csi_m(struct vc_data *vc)
 
 	for (i = 0; i <= vc->vc_npar; i++)
 		switch (vc->vc_par[i]) {
-		case 0:	/* all attributes off */
+		case CSI_m_DEFAULT:	/* all attributes off */
 			default_attr(vc);
 			break;
-		case 1:
+		case CSI_m_BOLD:
 			vc->state.intensity = VCI_BOLD;
 			break;
-		case 2:
+		case CSI_m_HALF_BRIGHT:
 			vc->state.intensity = VCI_HALF_BRIGHT;
 			break;
-		case 3:
+		case CSI_m_ITALIC:
 			vc->state.italic = true;
 			break;
-		case 21:
+		case CSI_m_DOUBLE_UNDERLINE:
 			/*
 			 * No console drivers support double underline, so
 			 * convert it to a single underline.
 			 */
-		case 4:
+		case CSI_m_UNDERLINE:
 			vc->state.underline = true;
 			break;
-		case 5:
+		case CSI_m_BLINK:
 			vc->state.blink = true;
 			break;
-		case 7:
+		case CSI_m_REVERSE:
 			vc->state.reverse = true;
 			break;
-		case 10: /* ANSI X3.64-1979 (SCO-ish?)
+		case CSI_m_PRI_FONT: /* ANSI X3.64-1979 (SCO-ish?)
 			  * Select primary font, don't display control chars if
 			  * defined, don't set bit 8 on output.
 			  */
@@ -1722,7 +1748,7 @@ static void csi_m(struct vc_data *vc)
 			vc->vc_disp_ctrl = 0;
 			vc->vc_toggle_meta = 0;
 			break;
-		case 11: /* ANSI X3.64-1979 (SCO-ish?)
+		case CSI_m_ALT_FONT1: /* ANSI X3.64-1979 (SCO-ish?)
 			  * Select first alternate font, lets chars < 32 be
 			  * displayed as ROM chars.
 			  */
@@ -1730,7 +1756,7 @@ static void csi_m(struct vc_data *vc)
 			vc->vc_disp_ctrl = 1;
 			vc->vc_toggle_meta = 0;
 			break;
-		case 12: /* ANSI X3.64-1979 (SCO-ish?)
+		case CSI_m_ALT_FONT2: /* ANSI X3.64-1979 (SCO-ish?)
 			  * Select second alternate font, toggle high bit
 			  * before displaying as ROM char.
 			  */
@@ -1738,47 +1764,51 @@ static void csi_m(struct vc_data *vc)
 			vc->vc_disp_ctrl = 1;
 			vc->vc_toggle_meta = 1;
 			break;
-		case 22:
+		case CSI_m_NORMAL_INTENSITY:
 			vc->state.intensity = VCI_NORMAL;
 			break;
-		case 23:
+		case CSI_m_NO_ITALIC:
 			vc->state.italic = false;
 			break;
-		case 24:
+		case CSI_m_NO_UNDERLINE:
 			vc->state.underline = false;
 			break;
-		case 25:
+		case CSI_m_NO_BLINK:
 			vc->state.blink = false;
 			break;
-		case 27:
+		case CSI_m_NO_REVERSE:
 			vc->state.reverse = false;
 			break;
-		case 38:
+		case CSI_m_FG_COLOR:
 			i = vc_t416_color(vc, i, rgb_foreground);
 			break;
-		case 48:
+		case CSI_m_BG_COLOR:
 			i = vc_t416_color(vc, i, rgb_background);
 			break;
-		case 39:
+		case CSI_m_DEFAULT_FG_COLOR:
 			vc->state.color = (vc->vc_def_color & 0x0f) |
 				(vc->state.color & 0xf0);
 			break;
-		case 49:
+		case CSI_m_DEFAULT_BG_COLOR:
 			vc->state.color = (vc->vc_def_color & 0xf0) |
 				(vc->state.color & 0x0f);
 			break;
-		default:
-			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
-				if (vc->vc_par[i] < 100)
-					vc->state.intensity = VCI_BOLD;
-				vc->vc_par[i] -= 60;
-			}
-			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
-				vc->state.color = color_table[vc->vc_par[i] - 30]
-					| (vc->state.color & 0xf0);
-			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
-				vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
-					| (vc->state.color & 0x0f);
+		case CSI_m_BRIGHT_FG_COLOR_BEG ... CSI_m_BRIGHT_FG_COLOR_END:
+			vc->state.intensity = VCI_BOLD;
+			vc->vc_par[i] -= CSI_m_BRIGHT_FG_COLOR_OFF;
+			fallthrough;
+		case CSI_m_FG_COLOR_BEG ... CSI_m_FG_COLOR_END:
+			vc->vc_par[i] -= CSI_m_FG_COLOR_BEG;
+			vc->state.color = color_table[vc->vc_par[i]] |
+				(vc->state.color & 0xf0);
+			break;
+		case CSI_m_BRIGHT_BG_COLOR_BEG ... CSI_m_BRIGHT_BG_COLOR_END:
+			vc->vc_par[i] -= CSI_m_BRIGHT_BG_COLOR_OFF;
+			fallthrough;
+		case CSI_m_BG_COLOR_BEG ... CSI_m_BG_COLOR_END:
+			vc->vc_par[i] -= CSI_m_BG_COLOR_BEG;
+			vc->state.color = (color_table[vc->vc_par[i]] << 4) |
+				(vc->state.color & 0x0f);
 			break;
 		}
 	update_attr(vc);
@@ -1832,133 +1862,175 @@ int mouse_reporting(void)
 	return vc_cons[fg_console].d->vc_report_mouse;
 }
 
+enum {
+	CSI_DEC_hl_CURSOR_KEYS	= 1,	/* CKM: cursor keys send ^[Ox/^[[x */
+	CSI_DEC_hl_132_COLUMNS	= 3,	/* COLM: 80/132 mode switch */
+	CSI_DEC_hl_REVERSE_VIDEO = 5,	/* SCNM */
+	CSI_DEC_hl_ORIGIN_MODE	= 6,	/* OM: origin relative/absolute */
+	CSI_DEC_hl_AUTOWRAP	= 7,	/* AWM */
+	CSI_DEC_hl_AUTOREPEAT	= 8,	/* ARM */
+	CSI_DEC_hl_MOUSE_X10	= 9,
+	CSI_DEC_hl_SHOW_CURSOR	= 25,	/* TCEM */
+	CSI_DEC_hl_MOUSE_VT200	= 1000,
+};
+
 /* console_lock is held */
-static void set_mode(struct vc_data *vc, int on_off)
+static void csi_DEC_hl(struct vc_data *vc, bool on_off)
 {
-	int i;
+	unsigned int i;
 
 	for (i = 0; i <= vc->vc_npar; i++)
-		if (vc->vc_priv == EPdec) {
-			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
-			case 1:			/* Cursor keys send ^[Ox/^[[x */
-				if (on_off)
-					set_kbd(vc, decckm);
-				else
-					clr_kbd(vc, decckm);
-				break;
-			case 3:	/* 80/132 mode switch unimplemented */
+		switch (vc->vc_par[i]) {
+		case CSI_DEC_hl_CURSOR_KEYS:
+			if (on_off)
+				set_kbd(vc, decckm);
+			else
+				clr_kbd(vc, decckm);
+			break;
+		case CSI_DEC_hl_132_COLUMNS:	/* unimplemented */
 #if 0
-				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
-				/* this alone does not suffice; some user mode
-				   utility has to change the hardware regs */
+			vc_resize(deccolm ? 132 : 80, vc->vc_rows);
+			/* this alone does not suffice; some user mode
+			   utility has to change the hardware regs */
 #endif
-				break;
-			case 5:			/* Inverted screen on/off */
-				if (vc->vc_decscnm != on_off) {
-					vc->vc_decscnm = on_off;
-					invert_screen(vc, 0,
-							vc->vc_screenbuf_size,
-							false);
-					update_attr(vc);
-				}
-				break;
-			case 6:			/* Origin relative/absolute */
-				vc->vc_decom = on_off;
-				gotoxay(vc, 0, 0);
-				break;
-			case 7:			/* Autowrap on/off */
-				vc->vc_decawm = on_off;
-				break;
-			case 8:			/* Autorepeat on/off */
-				if (on_off)
-					set_kbd(vc, decarm);
-				else
-					clr_kbd(vc, decarm);
-				break;
-			case 9:
-				vc->vc_report_mouse = on_off ? 1 : 0;
-				break;
-			case 25:		/* Cursor on/off */
-				vc->vc_deccm = on_off;
-				break;
-			case 1000:
-				vc->vc_report_mouse = on_off ? 2 : 0;
-				break;
-			}
-		} else {
-			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
-			case 3:			/* Monitor (display ctrls) */
-				vc->vc_disp_ctrl = on_off;
-				break;
-			case 4:			/* Insert Mode on/off */
-				vc->vc_decim = on_off;
-				break;
-			case 20:		/* Lf, Enter == CrLf/Lf */
-				if (on_off)
-					set_kbd(vc, lnm);
-				else
-					clr_kbd(vc, lnm);
-				break;
+			break;
+		case CSI_DEC_hl_REVERSE_VIDEO:
+			if (vc->vc_decscnm != on_off) {
+				vc->vc_decscnm = on_off;
+				invert_screen(vc, 0, vc->vc_screenbuf_size,
+					      false);
+				update_attr(vc);
 			}
+			break;
+		case CSI_DEC_hl_ORIGIN_MODE:
+			vc->vc_decom = on_off;
+			gotoxay(vc, 0, 0);
+			break;
+		case CSI_DEC_hl_AUTOWRAP:
+			vc->vc_decawm = on_off;
+			break;
+		case CSI_DEC_hl_AUTOREPEAT:
+			if (on_off)
+				set_kbd(vc, decarm);
+			else
+				clr_kbd(vc, decarm);
+			break;
+		case CSI_DEC_hl_MOUSE_X10:
+			vc->vc_report_mouse = on_off ? 1 : 0;
+			break;
+		case CSI_DEC_hl_SHOW_CURSOR:
+			vc->vc_deccm = on_off;
+			break;
+		case CSI_DEC_hl_MOUSE_VT200:
+			vc->vc_report_mouse = on_off ? 2 : 0;
+			break;
 		}
 }
 
+enum {
+	CSI_hl_DISPLAY_CTRL	= 3,	/* handle ansi control chars */
+	CSI_hl_INSERT		= 4,	/* IRM: insert/replace */
+	CSI_hl_AUTO_NL		= 20,	/* LNM: Enter == CrLf/Lf */
+};
+
 /* console_lock is held */
-static void setterm_command(struct vc_data *vc)
+static void csi_hl(struct vc_data *vc, bool on_off)
+{
+	unsigned int i;
+
+	for (i = 0; i <= vc->vc_npar; i++)
+		switch (vc->vc_par[i]) {	/* ANSI modes set/reset */
+		case CSI_hl_DISPLAY_CTRL:
+			vc->vc_disp_ctrl = on_off;
+			break;
+		case CSI_hl_INSERT:
+			vc->vc_decim = on_off;
+			break;
+		case CSI_hl_AUTO_NL:
+			if (on_off)
+				set_kbd(vc, lnm);
+			else
+				clr_kbd(vc, lnm);
+			break;
+		}
+}
+
+enum CSI_right_square_bracket {
+	CSI_RSB_COLOR_FOR_UNDERLINE		= 1,
+	CSI_RSB_COLOR_FOR_HALF_BRIGHT		= 2,
+	CSI_RSB_MAKE_CUR_COLOR_DEFAULT		= 8,
+	CSI_RSB_BLANKING_INTERVAL		= 9,
+	CSI_RSB_BELL_FREQUENCY			= 10,
+	CSI_RSB_BELL_DURATION			= 11,
+	CSI_RSB_BRING_CONSOLE_TO_FRONT		= 12,
+	CSI_RSB_UNBLANK				= 13,
+	CSI_RSB_VESA_OFF_INTERVAL		= 14,
+	CSI_RSB_BRING_PREV_CONSOLE_TO_FRONT	= 15,
+	CSI_RSB_CURSOR_BLINK_INTERVAL		= 16,
+};
+
+/*
+ * csi_RSB - csi+] (Right Square Bracket) handler
+ *
+ * These are linux console private sequences.
+ *
+ * console_lock is held
+ */
+static void csi_RSB(struct vc_data *vc)
 {
 	switch (vc->vc_par[0]) {
-	case 1:	/* set color for underline mode */
+	case CSI_RSB_COLOR_FOR_UNDERLINE:
 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
 			vc->vc_ulcolor = color_table[vc->vc_par[1]];
 			if (vc->state.underline)
 				update_attr(vc);
 		}
 		break;
-	case 2:	/* set color for half intensity mode */
+	case CSI_RSB_COLOR_FOR_HALF_BRIGHT:
 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
 			vc->vc_halfcolor = color_table[vc->vc_par[1]];
 			if (vc->state.intensity == VCI_HALF_BRIGHT)
 				update_attr(vc);
 		}
 		break;
-	case 8:	/* store colors as defaults */
+	case CSI_RSB_MAKE_CUR_COLOR_DEFAULT:
 		vc->vc_def_color = vc->vc_attr;
 		if (vc->vc_hi_font_mask == 0x100)
 			vc->vc_def_color >>= 1;
 		default_attr(vc);
 		update_attr(vc);
 		break;
-	case 9:	/* set blanking interval */
+	case CSI_RSB_BLANKING_INTERVAL:
 		blankinterval = min(vc->vc_par[1], 60U) * 60;
 		poke_blanked_console();
 		break;
-	case 10: /* set bell frequency in Hz */
+	case CSI_RSB_BELL_FREQUENCY:
 		if (vc->vc_npar >= 1)
 			vc->vc_bell_pitch = vc->vc_par[1];
 		else
 			vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
 		break;
-	case 11: /* set bell duration in msec */
+	case CSI_RSB_BELL_DURATION:
 		if (vc->vc_npar >= 1)
 			vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
 				msecs_to_jiffies(vc->vc_par[1]) : 0;
 		else
 			vc->vc_bell_duration = DEFAULT_BELL_DURATION;
 		break;
-	case 12: /* bring specified console to the front */
+	case CSI_RSB_BRING_CONSOLE_TO_FRONT:
 		if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
 			set_console(vc->vc_par[1] - 1);
 		break;
-	case 13: /* unblank the screen */
+	case CSI_RSB_UNBLANK:
 		poke_blanked_console();
 		break;
-	case 14: /* set vesa powerdown interval */
+	case CSI_RSB_VESA_OFF_INTERVAL:
 		vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
 		break;
-	case 15: /* activate the previous console */
+	case CSI_RSB_BRING_PREV_CONSOLE_TO_FRONT:
 		set_console(last_console);
 		break;
-	case 16: /* set cursor blink duration in msec */
+	case CSI_RSB_CURSOR_BLINK_INTERVAL:
 		if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
 				vc->vc_par[1] <= USHRT_MAX)
 			vc->vc_cur_blink_ms = vc->vc_par[1];
@@ -1971,41 +2043,32 @@ static void setterm_command(struct vc_data *vc)
 /* console_lock is held */
 static void csi_at(struct vc_data *vc, unsigned int nr)
 {
-	if (nr > vc->vc_cols - vc->state.x)
-		nr = vc->vc_cols - vc->state.x;
-	else if (!nr)
-		nr = 1;
+	nr = clamp(nr, 1, vc->vc_cols - vc->state.x);
 	insert_char(vc, nr);
 }
 
 /* console_lock is held */
-static void csi_L(struct vc_data *vc, unsigned int nr)
+static void csi_L(struct vc_data *vc)
 {
-	if (nr > vc->vc_rows - vc->state.y)
-		nr = vc->vc_rows - vc->state.y;
-	else if (!nr)
-		nr = 1;
+	unsigned int nr = clamp(vc->vc_par[0], 1, vc->vc_rows - vc->state.y);
+
 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
 	vc->vc_need_wrap = 0;
 }
 
 /* console_lock is held */
-static void csi_P(struct vc_data *vc, unsigned int nr)
+static void csi_P(struct vc_data *vc)
 {
-	if (nr > vc->vc_cols - vc->state.x)
-		nr = vc->vc_cols - vc->state.x;
-	else if (!nr)
-		nr = 1;
+	unsigned int nr = clamp(vc->vc_par[0], 1, vc->vc_cols - vc->state.x);
+
 	delete_char(vc, nr);
 }
 
 /* console_lock is held */
-static void csi_M(struct vc_data *vc, unsigned int nr)
+static void csi_M(struct vc_data *vc)
 {
-	if (nr > vc->vc_rows - vc->state.y)
-		nr = vc->vc_rows - vc->state.y;
-	else if (!nr)
-		nr=1;
+	unsigned int nr = clamp(vc->vc_par[0], 1, vc->vc_rows - vc->state.y);
+
 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
 	vc->vc_need_wrap = 0;
 }
@@ -2028,9 +2091,48 @@ static void restore_cur(struct vc_data *vc)
 	vc->vc_need_wrap = 0;
 }
 
-enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
-	EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
-	ESpalette, ESosc, ESapc, ESpm, ESdcs };
+/**
+ * enum vc_ctl_state - control characters state of a vt
+ *
+ * @ESnormal:		initial state, no control characters parsed
+ * @ESesc:		ESC parsed
+ * @ESsquare:		CSI parsed -- modifiers/parameters/ctrl chars expected
+ * @ESgetpars:		CSI parsed -- parameters/ctrl chars expected
+ * @ESfunckey:		CSI [ parsed
+ * @EShash:		ESC # parsed
+ * @ESsetG0:		ESC ( parsed
+ * @ESsetG1:		ESC ) parsed
+ * @ESpercent:		ESC % parsed
+ * @EScsiignore:	CSI [0x20-0x3f] parsed
+ * @ESnonstd:		OSC parsed
+ * @ESpalette:		OSC P parsed
+ * @ESosc:		OSC [0-9] parsed
+ * @ESANSI_first:	first state for ignoring ansi control sequences
+ * @ESapc:		ESC _ parsed
+ * @ESpm:		ESC ^ parsed
+ * @ESdcs:		ESC P parsed
+ * @ESANSI_last:	last state for ignoring ansi control sequences
+ */
+enum vc_ctl_state {
+	ESnormal,
+	ESesc,
+	ESsquare,
+	ESgetpars,
+	ESfunckey,
+	EShash,
+	ESsetG0,
+	ESsetG1,
+	ESpercent,
+	EScsiignore,
+	ESnonstd,
+	ESpalette,
+	ESosc,
+	ESANSI_first = ESosc,
+	ESapc,
+	ESpm,
+	ESdcs,
+	ESANSI_last = ESdcs,
+};
 
 /* console_lock is held (except via vc_init()) */
 static void reset_terminal(struct vc_data *vc, int do_clear)
@@ -2078,10 +2180,10 @@ static void reset_terminal(struct vc_data *vc, int do_clear)
 	gotoxy(vc, 0, 0);
 	save_cur(vc);
 	if (do_clear)
-	    csi_J(vc, 2);
+	    csi_J(vc, CSI_J_VISIBLE);
 }
 
-static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
+static void vc_setGx(struct vc_data *vc, unsigned int which, u8 c)
 {
 	unsigned char *charset = &vc->state.Gx_charset[which];
 
@@ -2104,36 +2206,54 @@ static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
 		vc->vc_translate = set_translate(*charset, vc);
 }
 
-/* is this state an ANSI control string? */
-static bool ansi_control_string(unsigned int state)
+static bool ansi_control_string(enum vc_ctl_state state)
 {
-	if (state == ESosc || state == ESapc || state == ESpm || state == ESdcs)
-		return true;
-	return false;
+	return state >= ESANSI_first && state <= ESANSI_last;
 }
 
-/* console_lock is held */
-static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
+enum {
+	ASCII_NULL		= 0,
+	ASCII_BELL		= 7,
+	ASCII_BACKSPACE		= 8,
+	ASCII_IGNORE_FIRST	= ASCII_BACKSPACE,
+	ASCII_HTAB		= 9,
+	ASCII_LINEFEED		= 10,
+	ASCII_VTAB		= 11,
+	ASCII_FORMFEED		= 12,
+	ASCII_CAR_RET		= 13,
+	ASCII_IGNORE_LAST	= ASCII_CAR_RET,
+	ASCII_SHIFTOUT		= 14,
+	ASCII_SHIFTIN		= 15,
+	ASCII_CANCEL		= 24,
+	ASCII_SUBSTITUTE	= 26,
+	ASCII_ESCAPE		= 27,
+	ASCII_CSI_IGNORE_FIRST	= ' ', /* 0x2x, 0x3a and 0x3c - 0x3f */
+	ASCII_CSI_IGNORE_LAST	= '?',
+	ASCII_DEL		= 127,
+	ASCII_EXT_CSI		= 128 + ASCII_ESCAPE,
+};
+
+/*
+ * Handle ascii characters in control sequences and change states accordingly.
+ * E.g. ESC sets the state of vc to ESesc.
+ *
+ * Returns: true if @c handled.
+ */
+static bool handle_ascii(struct tty_struct *tty, struct vc_data *vc, u8 c)
 {
-	/*
-	 *  Control characters can be used in the _middle_
-	 *  of an escape sequence, aside from ANSI control strings.
-	 */
-	if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
-		return;
 	switch (c) {
-	case 0:
-		return;
-	case 7:
+	case ASCII_NULL:
+		return true;
+	case ASCII_BELL:
 		if (ansi_control_string(vc->vc_state))
 			vc->vc_state = ESnormal;
 		else if (vc->vc_bell_duration)
 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
-		return;
-	case 8:
+		return true;
+	case ASCII_BACKSPACE:
 		bs(vc);
-		return;
-	case 9:
+		return true;
+	case ASCII_HTAB:
 		vc->vc_pos -= (vc->state.x << 1);
 
 		vc->state.x = find_next_bit(vc->vc_tab_stop,
@@ -2144,119 +2264,330 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
 
 		vc->vc_pos += (vc->state.x << 1);
 		notify_write(vc, '\t');
-		return;
-	case 10: case 11: case 12:
+		return true;
+	case ASCII_LINEFEED:
+	case ASCII_VTAB:
+	case ASCII_FORMFEED:
 		lf(vc);
 		if (!is_kbd(vc, lnm))
-			return;
+			return true;
 		fallthrough;
-	case 13:
+	case ASCII_CAR_RET:
 		cr(vc);
-		return;
-	case 14:
+		return true;
+	case ASCII_SHIFTOUT:
 		vc->state.charset = 1;
 		vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
 		vc->vc_disp_ctrl = 1;
-		return;
-	case 15:
+		return true;
+	case ASCII_SHIFTIN:
 		vc->state.charset = 0;
 		vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
 		vc->vc_disp_ctrl = 0;
-		return;
-	case 24: case 26:
+		return true;
+	case ASCII_CANCEL:
+	case ASCII_SUBSTITUTE:
 		vc->vc_state = ESnormal;
-		return;
-	case 27:
+		return true;
+	case ASCII_ESCAPE:
 		vc->vc_state = ESesc;
-		return;
-	case 127:
+		return true;
+	case ASCII_DEL:
 		del(vc);
-		return;
-	case 128+27:
+		return true;
+	case ASCII_EXT_CSI:
 		vc->vc_state = ESsquare;
-		return;
+		return true;
 	}
-	switch(vc->vc_state) {
-	case ESesc:
-		vc->vc_state = ESnormal;
-		switch (c) {
-		case '[':
-			vc->vc_state = ESsquare;
-			return;
-		case ']':
-			vc->vc_state = ESnonstd;
-			return;
-		case '_':
-			vc->vc_state = ESapc;
-			return;
-		case '^':
-			vc->vc_state = ESpm;
-			return;
-		case '%':
-			vc->vc_state = ESpercent;
-			return;
-		case 'E':
-			cr(vc);
-			lf(vc);
-			return;
-		case 'M':
-			ri(vc);
-			return;
-		case 'D':
-			lf(vc);
-			return;
-		case 'H':
-			if (vc->state.x < VC_TABSTOPS_COUNT)
-				set_bit(vc->state.x, vc->vc_tab_stop);
-			return;
-		case 'P':
-			vc->vc_state = ESdcs;
-			return;
-		case 'Z':
+
+	return false;
+}
+
+/*
+ * Handle a character (@c) following an ESC (when @vc is in the ESesc state).
+ * E.g. previous ESC with @c == '[' here yields the ESsquare state (that is:
+ * CSI).
+ */
+static void handle_esc(struct tty_struct *tty, struct vc_data *vc, u8 c)
+{
+	vc->vc_state = ESnormal;
+	switch (c) {
+	case '[':
+		vc->vc_state = ESsquare;
+		break;
+	case ']':
+		vc->vc_state = ESnonstd;
+		break;
+	case '_':
+		vc->vc_state = ESapc;
+		break;
+	case '^':
+		vc->vc_state = ESpm;
+		break;
+	case '%':
+		vc->vc_state = ESpercent;
+		break;
+	case 'E':
+		cr(vc);
+		lf(vc);
+		break;
+	case 'M':
+		ri(vc);
+		break;
+	case 'D':
+		lf(vc);
+		break;
+	case 'H':
+		if (vc->state.x < VC_TABSTOPS_COUNT)
+			set_bit(vc->state.x, vc->vc_tab_stop);
+		break;
+	case 'P':
+		vc->vc_state = ESdcs;
+		break;
+	case 'Z':
+		respond_ID(tty);
+		break;
+	case '7':
+		save_cur(vc);
+		break;
+	case '8':
+		restore_cur(vc);
+		break;
+	case '(':
+		vc->vc_state = ESsetG0;
+		break;
+	case ')':
+		vc->vc_state = ESsetG1;
+		break;
+	case '#':
+		vc->vc_state = EShash;
+		break;
+	case 'c':
+		reset_terminal(vc, 1);
+		break;
+	case '>':  /* Numeric keypad */
+		clr_kbd(vc, kbdapplic);
+		break;
+	case '=':  /* Appl. keypad */
+		set_kbd(vc, kbdapplic);
+		break;
+	}
+}
+
+/*
+ * Handle special DEC control sequences ("ESC [ ? parameters char"). Parameters
+ * are in @vc->vc_par and the char is in @c here.
+ */
+static void csi_DEC(struct tty_struct *tty, struct vc_data *vc, u8 c)
+{
+	switch (c) {
+	case 'h':
+		csi_DEC_hl(vc, true);
+		break;
+	case 'l':
+		csi_DEC_hl(vc, false);
+		break;
+	case 'c':
+		if (vc->vc_par[0])
+			vc->vc_cursor_type = CUR_MAKE(vc->vc_par[0],
+						      vc->vc_par[1],
+						      vc->vc_par[2]);
+		else
+			vc->vc_cursor_type = cur_default;
+		break;
+	case 'm':
+		clear_selection();
+		if (vc->vc_par[0])
+			vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
+		else
+			vc->vc_complement_mask = vc->vc_s_complement_mask;
+		break;
+	case 'n':
+		if (vc->vc_par[0] == 5)
+			status_report(tty);
+		else if (vc->vc_par[0] == 6)
+			cursor_report(vc, tty);
+		break;
+	}
+}
+
+/*
+ * Handle Control Sequence Introducer control characters. That is
+ * "ESC [ parameters char". Parameters are in @vc->vc_par and the char is in
+ * @c here.
+ */
+static void csi_ECMA(struct tty_struct *tty, struct vc_data *vc, u8 c)
+{
+	switch (c) {
+	case 'G':
+	case '`':
+		if (vc->vc_par[0])
+			vc->vc_par[0]--;
+		gotoxy(vc, vc->vc_par[0], vc->state.y);
+		break;
+	case 'A':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
+		break;
+	case 'B':
+	case 'e':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
+		break;
+	case 'C':
+	case 'a':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
+		break;
+	case 'D':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
+		break;
+	case 'E':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
+		break;
+	case 'F':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
+		break;
+	case 'd':
+		if (vc->vc_par[0])
+			vc->vc_par[0]--;
+		gotoxay(vc, vc->state.x ,vc->vc_par[0]);
+		break;
+	case 'H':
+	case 'f':
+		if (vc->vc_par[0])
+			vc->vc_par[0]--;
+		if (vc->vc_par[1])
+			vc->vc_par[1]--;
+		gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
+		break;
+	case 'J':
+		csi_J(vc, vc->vc_par[0]);
+		break;
+	case 'K':
+		csi_K(vc);
+		break;
+	case 'L':
+		csi_L(vc);
+		break;
+	case 'M':
+		csi_M(vc);
+		break;
+	case 'P':
+		csi_P(vc);
+		break;
+	case 'c':
+		if (!vc->vc_par[0])
 			respond_ID(tty);
-			return;
-		case '7':
-			save_cur(vc);
-			return;
-		case '8':
-			restore_cur(vc);
-			return;
-		case '(':
-			vc->vc_state = ESsetG0;
-			return;
-		case ')':
-			vc->vc_state = ESsetG1;
-			return;
-		case '#':
-			vc->vc_state = EShash;
-			return;
-		case 'c':
-			reset_terminal(vc, 1);
-			return;
-		case '>':  /* Numeric keypad */
-			clr_kbd(vc, kbdapplic);
-			return;
-		case '=':  /* Appl. keypad */
-			set_kbd(vc, kbdapplic);
-			return;
+		break;
+	case 'g':
+		if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
+			set_bit(vc->state.x, vc->vc_tab_stop);
+		else if (vc->vc_par[0] == 3)
+			bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
+		break;
+	case 'h':
+		csi_hl(vc, true);
+		break;
+	case 'l':
+		csi_hl(vc, false);
+		break;
+	case 'm':
+		csi_m(vc);
+		break;
+	case 'n':
+		if (vc->vc_par[0] == 5)
+			status_report(tty);
+		else if (vc->vc_par[0] == 6)
+			cursor_report(vc, tty);
+		break;
+	case 'q': /* DECLL - but only 3 leds */
+		/* map 0,1,2,3 to 0,1,2,4 */
+		if (vc->vc_par[0] < 4)
+			vt_set_led_state(vc->vc_num,
+				    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
+		break;
+	case 'r':
+		if (!vc->vc_par[0])
+			vc->vc_par[0]++;
+		if (!vc->vc_par[1])
+			vc->vc_par[1] = vc->vc_rows;
+		/* Minimum allowed region is 2 lines */
+		if (vc->vc_par[0] < vc->vc_par[1] &&
+		    vc->vc_par[1] <= vc->vc_rows) {
+			vc->vc_top = vc->vc_par[0] - 1;
+			vc->vc_bottom = vc->vc_par[1];
+			gotoxay(vc, 0, 0);
 		}
+		break;
+	case 's':
+		save_cur(vc);
+		break;
+	case 'u':
+		restore_cur(vc);
+		break;
+	case 'X':
+		csi_X(vc);
+		break;
+	case '@':
+		csi_at(vc, vc->vc_par[0]);
+		break;
+	case ']':
+		csi_RSB(vc);
+		break;
+	}
+
+}
+
+static void vc_reset_params(struct vc_data *vc)
+{
+	memset(vc->vc_par, 0, sizeof(vc->vc_par));
+	vc->vc_npar = 0;
+}
+
+/* console_lock is held */
+static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, u8 c)
+{
+	/*
+	 *  Control characters can be used in the _middle_
+	 *  of an escape sequence, aside from ANSI control strings.
+	 */
+	if (ansi_control_string(vc->vc_state) && c >= ASCII_IGNORE_FIRST &&
+	    c <= ASCII_IGNORE_LAST)
+		return;
+
+	if (handle_ascii(tty, vc, c))
+		return;
+
+	switch(vc->vc_state) {
+	case ESesc:	/* ESC */
+		handle_esc(tty, vc, c);
 		return;
-	case ESnonstd:
-		if (c=='P') {   /* palette escape sequence */
-			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
-				vc->vc_par[vc->vc_npar] = 0;
-			vc->vc_npar = 0;
+	case ESnonstd:	/* ESC ] aka OSC */
+		switch (c) {
+		case 'P': /* palette escape sequence */
+			vc_reset_params(vc);
 			vc->vc_state = ESpalette;
 			return;
-		} else if (c=='R') {   /* reset palette */
+		case 'R': /* reset palette */
 			reset_palette(vc);
-			vc->vc_state = ESnormal;
-		} else if (c>='0' && c<='9')
+			break;
+		case '0' ... '9':
 			vc->vc_state = ESosc;
-		else
-			vc->vc_state = ESnormal;
+			return;
+		}
+		vc->vc_state = ESnormal;
 		return;
-	case ESpalette:
+	case ESpalette:	/* ESC ] P aka OSC P */
 		if (isxdigit(c)) {
 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
 			if (vc->vc_npar == 7) {
@@ -2273,16 +2604,14 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
 		} else
 			vc->vc_state = ESnormal;
 		return;
-	case ESsquare:
-		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
-			vc->vc_par[vc->vc_npar] = 0;
-		vc->vc_npar = 0;
+	case ESsquare:	/* ESC [ aka CSI, parameters or modifiers expected */
+		vc_reset_params(vc);
+
 		vc->vc_state = ESgetpars;
-		if (c == '[') { /* Function key */
-			vc->vc_state=ESfunckey;
-			return;
-		}
 		switch (c) {
+		case '[': /* Function key */
+			vc->vc_state = ESfunckey;
+			return;
 		case '?':
 			vc->vc_priv = EPdec;
 			return;
@@ -2298,182 +2627,44 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
 		}
 		vc->vc_priv = EPecma;
 		fallthrough;
-	case ESgetpars:
-		if (c == ';' && vc->vc_npar < NPAR - 1) {
-			vc->vc_npar++;
-			return;
-		} else if (c>='0' && c<='9') {
+	case ESgetpars: /* ESC [ aka CSI, parameters expected */
+		switch (c) {
+		case ';':
+			if (vc->vc_npar < NPAR - 1) {
+				vc->vc_npar++;
+				return;
+			}
+			break;
+		case '0' ... '9':
 			vc->vc_par[vc->vc_npar] *= 10;
 			vc->vc_par[vc->vc_npar] += c - '0';
 			return;
 		}
-		if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
+		if (c >= ASCII_CSI_IGNORE_FIRST && c <= ASCII_CSI_IGNORE_LAST) {
 			vc->vc_state = EScsiignore;
 			return;
 		}
+
+		/* parameters done, handle the control char @c */
+
 		vc->vc_state = ESnormal;
-		switch(c) {
-		case 'h':
-			if (vc->vc_priv <= EPdec)
-				set_mode(vc, 1);
-			return;
-		case 'l':
-			if (vc->vc_priv <= EPdec)
-				set_mode(vc, 0);
-			return;
-		case 'c':
-			if (vc->vc_priv == EPdec) {
-				if (vc->vc_par[0])
-					vc->vc_cursor_type =
-						CUR_MAKE(vc->vc_par[0],
-							 vc->vc_par[1],
-							 vc->vc_par[2]);
-				else
-					vc->vc_cursor_type = cur_default;
-				return;
-			}
-			break;
-		case 'm':
-			if (vc->vc_priv == EPdec) {
-				clear_selection();
-				if (vc->vc_par[0])
-					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
-				else
-					vc->vc_complement_mask = vc->vc_s_complement_mask;
-				return;
-			}
-			break;
-		case 'n':
-			if (vc->vc_priv == EPecma) {
-				if (vc->vc_par[0] == 5)
-					status_report(tty);
-				else if (vc->vc_par[0] == 6)
-					cursor_report(vc, tty);
-			}
-			return;
-		}
-		if (vc->vc_priv != EPecma) {
-			vc->vc_priv = EPecma;
-			return;
-		}
-		switch(c) {
-		case 'G': case '`':
-			if (vc->vc_par[0])
-				vc->vc_par[0]--;
-			gotoxy(vc, vc->vc_par[0], vc->state.y);
-			return;
-		case 'A':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
-			return;
-		case 'B': case 'e':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
-			return;
-		case 'C': case 'a':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
-			return;
-		case 'D':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
-			return;
-		case 'E':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
-			return;
-		case 'F':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
-			return;
-		case 'd':
-			if (vc->vc_par[0])
-				vc->vc_par[0]--;
-			gotoxay(vc, vc->state.x ,vc->vc_par[0]);
-			return;
-		case 'H': case 'f':
-			if (vc->vc_par[0])
-				vc->vc_par[0]--;
-			if (vc->vc_par[1])
-				vc->vc_par[1]--;
-			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
-			return;
-		case 'J':
-			csi_J(vc, vc->vc_par[0]);
-			return;
-		case 'K':
-			csi_K(vc, vc->vc_par[0]);
-			return;
-		case 'L':
-			csi_L(vc, vc->vc_par[0]);
-			return;
-		case 'M':
-			csi_M(vc, vc->vc_par[0]);
-			return;
-		case 'P':
-			csi_P(vc, vc->vc_par[0]);
-			return;
-		case 'c':
-			if (!vc->vc_par[0])
-				respond_ID(tty);
-			return;
-		case 'g':
-			if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
-				set_bit(vc->state.x, vc->vc_tab_stop);
-			else if (vc->vc_par[0] == 3)
-				bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
-			return;
-		case 'm':
-			csi_m(vc);
-			return;
-		case 'q': /* DECLL - but only 3 leds */
-			/* map 0,1,2,3 to 0,1,2,4 */
-			if (vc->vc_par[0] < 4)
-				vt_set_led_state(vc->vc_num,
-					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
-			return;
-		case 'r':
-			if (!vc->vc_par[0])
-				vc->vc_par[0]++;
-			if (!vc->vc_par[1])
-				vc->vc_par[1] = vc->vc_rows;
-			/* Minimum allowed region is 2 lines */
-			if (vc->vc_par[0] < vc->vc_par[1] &&
-			    vc->vc_par[1] <= vc->vc_rows) {
-				vc->vc_top = vc->vc_par[0] - 1;
-				vc->vc_bottom = vc->vc_par[1];
-				gotoxay(vc, 0, 0);
-			}
-			return;
-		case 's':
-			save_cur(vc);
-			return;
-		case 'u':
-			restore_cur(vc);
-			return;
-		case 'X':
-			csi_X(vc, vc->vc_par[0]);
+
+		switch (vc->vc_priv) {
+		case EPdec:
+			csi_DEC(tty, vc, c);
 			return;
-		case '@':
-			csi_at(vc, vc->vc_par[0]);
+		case EPecma:
+			csi_ECMA(tty, vc, c);
 			return;
-		case ']': /* setterm functions */
-			setterm_command(vc);
+		default:
 			return;
 		}
-		return;
 	case EScsiignore:
-		if (c >= 0x20 && c <= 0x3f)
+		if (c >= ASCII_CSI_IGNORE_FIRST && c <= ASCII_CSI_IGNORE_LAST)
 			return;
 		vc->vc_state = ESnormal;
 		return;
-	case ESpercent:
+	case ESpercent:	/* ESC % */
 		vc->vc_state = ESnormal;
 		switch (c) {
 		case '@':  /* defined in ISO 2022 */
@@ -2485,36 +2676,36 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
 			return;
 		}
 		return;
-	case ESfunckey:
+	case ESfunckey:	/* ESC [ [ aka CSI [ */
 		vc->vc_state = ESnormal;
 		return;
-	case EShash:
+	case EShash:	/* ESC # */
 		vc->vc_state = ESnormal;
 		if (c == '8') {
 			/* DEC screen alignment test. kludge :-) */
 			vc->vc_video_erase_char =
 				(vc->vc_video_erase_char & 0xff00) | 'E';
-			csi_J(vc, 2);
+			csi_J(vc, CSI_J_VISIBLE);
 			vc->vc_video_erase_char =
 				(vc->vc_video_erase_char & 0xff00) | ' ';
 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
 		}
 		return;
-	case ESsetG0:
+	case ESsetG0:	/* ESC ( */
 		vc_setGx(vc, 0, c);
 		vc->vc_state = ESnormal;
 		return;
-	case ESsetG1:
+	case ESsetG1:	/* ESC ) */
 		vc_setGx(vc, 1, c);
 		vc->vc_state = ESnormal;
 		return;
-	case ESapc:
+	case ESapc:	/* ESC _ */
 		return;
-	case ESosc:
+	case ESosc:	/* ESC ] [0-9] aka OSC [0-9] */
 		return;
-	case ESpm:
+	case ESpm:	/* ESC ^ */
 		return;
-	case ESdcs:
+	case ESdcs:	/* ESC P */
 		return;
 	default:
 		vc->vc_state = ESnormal;
@@ -2588,33 +2779,39 @@ static inline int vc_translate_ascii(const struct vc_data *vc, int c)
 
 
 /**
- * vc_sanitize_unicode - Replace invalid Unicode code points with U+FFFD
- * @c: the received character, or U+FFFD for invalid sequences.
+ * vc_sanitize_unicode - Replace invalid Unicode code points with ``U+FFFD``
+ * @c: the received code point
  */
 static inline int vc_sanitize_unicode(const int c)
 {
-	if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
+	if (c >= 0xd800 && c <= 0xdfff)
 		return 0xfffd;
 
 	return c;
 }
 
 /**
- * vc_translate_unicode - Combine UTF-8 into Unicode in @vc_utf_char
+ * vc_translate_unicode - Combine UTF-8 into Unicode in &vc_data.vc_utf_char
  * @vc: virtual console
- * @c: character to translate
- * @rescan: we return true if we need more (continuation) data
+ * @c: UTF-8 byte to translate
+ * @rescan: set to true iff @c wasn't consumed here and needs to be re-processed
+ *
+ * * &vc_data.vc_utf_char is the being-constructed Unicode code point.
+ * * &vc_data.vc_utf_count is the number of continuation bytes still expected to
+ *   arrive.
+ * * &vc_data.vc_npar is the number of continuation bytes arrived so far.
  *
- * @vc_utf_char is the being-constructed unicode character.
- * @vc_utf_count is the number of continuation bytes still expected to arrive.
- * @vc_npar is the number of continuation bytes arrived so far.
+ * Return:
+ * * %-1 - Input OK so far, @c consumed, further bytes expected.
+ * * %0xFFFD - Possibility 1: input invalid, @c may have been consumed (see
+ *             desc. of @rescan). Possibility 2: input OK, @c consumed,
+ *             ``U+FFFD`` is the resulting code point. ``U+FFFD`` is valid,
+ *             ``REPLACEMENT CHARACTER``.
+ * * otherwise - Input OK, @c consumed, resulting code point returned.
  */
 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
 {
-	static const u32 utf8_length_changes[] = {
-		0x0000007f, 0x000007ff, 0x0000ffff,
-		0x001fffff, 0x03ffffff, 0x7fffffff
-	};
+	static const u32 utf8_length_changes[] = {0x7f, 0x7ff, 0xffff, 0x10ffff};
 
 	/* Continuation byte received */
 	if ((c & 0xc0) == 0x80) {
@@ -2660,14 +2857,7 @@ static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
 	} else if ((c & 0xf8) == 0xf0) {
 		vc->vc_utf_count = 3;
 		vc->vc_utf_char = (c & 0x07);
-	} else if ((c & 0xfc) == 0xf8) {
-		vc->vc_utf_count = 4;
-		vc->vc_utf_char = (c & 0x03);
-	} else if ((c & 0xfe) == 0xfc) {
-		vc->vc_utf_count = 5;
-		vc->vc_utf_char = (c & 0x01);
 	} else {
-		/* 254 and 255 are invalid */
 		return 0xfffd;
 	}
 
@@ -2711,9 +2901,13 @@ static bool vc_is_control(struct vc_data *vc, int tc, int c)
 	 * as cursor movement) and should not be displayed as a glyph unless
 	 * the disp_ctrl mode is explicitly enabled.
 	 */
-	static const u32 CTRL_ACTION = 0x0d00ff81;
+	static const u32 CTRL_ACTION = BIT(ASCII_NULL) |
+		GENMASK(ASCII_SHIFTIN, ASCII_BELL) | BIT(ASCII_CANCEL) |
+		BIT(ASCII_SUBSTITUTE) | BIT(ASCII_ESCAPE);
 	/* Cannot be overridden by disp_ctrl */
-	static const u32 CTRL_ALWAYS = 0x0800f501;
+	static const u32 CTRL_ALWAYS = BIT(ASCII_NULL) | BIT(ASCII_BACKSPACE) |
+		BIT(ASCII_LINEFEED) | BIT(ASCII_SHIFTIN) | BIT(ASCII_SHIFTOUT) |
+		BIT(ASCII_CAR_RET) | BIT(ASCII_FORMFEED) | BIT(ASCII_ESCAPE);
 
 	if (vc->vc_state != ESnormal)
 		return true;
@@ -2730,17 +2924,17 @@ static bool vc_is_control(struct vc_data *vc, int tc, int c)
 	 * useless without them; to display an arbitrary font position use the
 	 * direct-to-font zone in UTF-8 mode.
 	 */
-	if (c < 32) {
+	if (c < BITS_PER_TYPE(CTRL_ALWAYS)) {
 		if (vc->vc_disp_ctrl)
 			return CTRL_ALWAYS & BIT(c);
 		else
 			return vc->vc_utf || (CTRL_ACTION & BIT(c));
 	}
 
-	if (c == 127 && !vc->vc_disp_ctrl)
+	if (c == ASCII_DEL && !vc->vc_disp_ctrl)
 		return true;
 
-	if (c == 128 + 27)
+	if (c == ASCII_EXT_CSI)
 		return true;
 
 	return false;
@@ -2852,7 +3046,7 @@ static int do_con_write(struct tty_struct *tty, const u8 *buf, int count)
 	};
 	int c, tc, n = 0;
 	unsigned int currcons;
-	struct vc_data *vc;
+	struct vc_data *vc = tty->driver_data;
 	struct vt_notifier_param param;
 	bool rescan;
 
@@ -2860,13 +3054,6 @@ static int do_con_write(struct tty_struct *tty, const u8 *buf, int count)
 		return count;
 
 	console_lock();
-	vc = tty->driver_data;
-	if (vc == NULL) {
-		pr_err("vt: argh, driver_data is NULL !\n");
-		console_unlock();
-		return 0;
-	}
-
 	currcons = vc->vc_num;
 	if (!vc_cons_allocated(currcons)) {
 		/* could this happen? */
@@ -2883,7 +3070,7 @@ static int do_con_write(struct tty_struct *tty, const u8 *buf, int count)
 	param.vc = vc;
 
 	while (!tty->flow.stopped && count) {
-		int orig = *buf;
+		u8 orig = *buf;
 		buf++;
 		n++;
 		count--;
@@ -2992,16 +3179,16 @@ struct tty_driver *console_driver;
 #ifdef CONFIG_VT_CONSOLE
 
 /**
- * vt_kmsg_redirect() - Sets/gets the kernel message console
- * @new:	The new virtual terminal number or -1 if the console should stay
- * 		unchanged
+ * vt_kmsg_redirect() - sets/gets the kernel message console
+ * @new: the new virtual terminal number or -1 if the console should stay
+ *	unchanged
  *
  * By default, the kernel messages are always printed on the current virtual
  * console. However, the user may modify that default with the
- * TIOCL_SETKMSGREDIRECT ioctl call.
+ * %TIOCL_SETKMSGREDIRECT ioctl call.
  *
  * This function sets the kernel message console to be @new. It returns the old
- * virtual console number. The virtual terminal number 0 (both as parameter and
+ * virtual console number. The virtual terminal number %0 (both as parameter and
  * return value) means no redirection (i.e. always printed on the currently
  * active console).
  *
@@ -3009,8 +3196,8 @@ struct tty_driver *console_driver;
  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
  * case to make the code more understandable.
  *
- * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
- * the parameter and always returns 0.
+ * When the kernel is compiled without %CONFIG_VT_CONSOLE, this function ignores
+ * the parameter and always returns %0.
  */
 int vt_kmsg_redirect(int new)
 {
@@ -3065,22 +3252,23 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
 	cnt = 0;
 	while (count--) {
 		c = *b++;
-		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
+		if (c == ASCII_LINEFEED || c == ASCII_CAR_RET ||
+		    c == ASCII_BACKSPACE || vc->vc_need_wrap) {
 			if (cnt && con_is_visible(vc))
 				vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
 			cnt = 0;
-			if (c == 8) {		/* backspace */
+			if (c == ASCII_BACKSPACE) {
 				bs(vc);
 				start = (ushort *)vc->vc_pos;
 				start_x = vc->state.x;
 				continue;
 			}
-			if (c != 13)
+			if (c != ASCII_CAR_RET)
 				lf(vc);
 			cr(vc);
 			start = (ushort *)vc->vc_pos;
 			start_x = vc->state.x;
-			if (c == 10 || c == 13)
+			if (c == ASCII_LINEFEED || c == ASCII_CAR_RET)
 				continue;
 		}
 		vc_uniscr_putc(vc, c);
@@ -3144,6 +3332,8 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
 {
 	char type, data;
 	char __user *p = (char __user *)arg;
+	void __user *param_aligned32 = (u32 __user *)arg + 1;
+	void __user *param = (void __user *)arg + 1;
 	int lines;
 	int ret;
 
@@ -3157,8 +3347,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
 	case TIOCL_SETSEL:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
-		return set_selection_user((struct tiocl_selection
-					 __user *)(p+1), tty);
+		return set_selection_user(param, tty);
 	case TIOCL_PASTESEL:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
@@ -3171,10 +3360,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
 	case TIOCL_SELLOADLUT:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
-		console_lock();
-		ret = sel_loadlut(p);
-		console_unlock();
-		break;
+		return sel_loadlut(param_aligned32);
 	case TIOCL_GETSHIFTSTATE:
 		/*
 		 * Make it possible to react to Shift+Mousebutton. Note that
@@ -3190,10 +3376,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
 		console_unlock();
 		return put_user(data, p);
 	case TIOCL_SETVESABLANK:
-		console_lock();
-		ret = set_vesa_blanking(p);
-		console_unlock();
-		break;
+		return set_vesa_blanking(param);
 	case TIOCL_GETKMSGREDIRECT:
 		data = vt_get_kmsg_redirect();
 		return put_user(data, p);
@@ -3214,7 +3397,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
 		 */
 		return fg_console;
 	case TIOCL_SCROLLCONSOLE:
-		if (get_user(lines, (s32 __user *)(p+4)))
+		if (get_user(lines, (s32 __user *)param_aligned32))
 			return -EFAULT;
 
 		/*
@@ -3312,16 +3495,13 @@ static void con_start(struct tty_struct *tty)
 
 static void con_flush_chars(struct tty_struct *tty)
 {
-	struct vc_data *vc;
+	struct vc_data *vc = tty->driver_data;
 
 	if (in_interrupt())	/* from flush_to_ldisc */
 		return;
 
-	/* if we race with con_close(), vt may be null */
 	console_lock();
-	vc = tty->driver_data;
-	if (vc)
-		set_cursor(vc);
+	set_cursor(vc);
 	console_unlock();
 }
 
@@ -3396,6 +3576,15 @@ static void con_cleanup(struct tty_struct *tty)
 	tty_port_put(&vc->port);
 }
 
+/*
+ * We can't deal with anything but the N_TTY ldisc,
+ * because we can sleep in our write() routine.
+ */
+static int con_ldisc_ok(struct tty_struct *tty, int ldisc)
+{
+	return ldisc == N_TTY ? 0 : -EINVAL;
+}
+
 static int default_color           = 7; /* white */
 static int default_italic_color    = 2; // green (ASCII)
 static int default_underline_color = 3; // cyan (ASCII)
@@ -3471,7 +3660,7 @@ static int __init con_init(void)
 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
 		tty_port_init(&vc->port);
-		visual_init(vc, currcons, 1);
+		visual_init(vc, currcons, true);
 		/* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
 		vc_init(vc, currcons || !vc->vc_sw->con_save_screen);
@@ -3481,7 +3670,7 @@ static int __init con_init(void)
 	set_origin(vc);
 	save_screen(vc);
 	gotoxy(vc, vc->state.x, vc->state.y);
-	csi_J(vc, 0);
+	csi_J(vc, CSI_J_CURSOR_TO_END);
 	update_screen(vc);
 	pr_info("Console: %s %s %dx%d\n",
 		vc->vc_can_do_color ? "colour" : "mono",
@@ -3515,6 +3704,7 @@ static const struct tty_operations con_ops = {
 	.resize = vt_resize,
 	.shutdown = con_shutdown,
 	.cleanup = con_cleanup,
+	.ldisc_ok = con_ldisc_ok,
 };
 
 static struct cdev vc0_cdev;
@@ -3640,7 +3830,7 @@ static int do_bind_con_driver(const struct consw *csw, int first, int last,
 		old_was_color = vc->vc_can_do_color;
 		vc->vc_sw->con_deinit(vc);
 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
-		visual_init(vc, i, 0);
+		visual_init(vc, i, false);
 		set_origin(vc);
 		update_attr(vc);
 
@@ -3930,7 +4120,7 @@ static void vtconsole_deinit_device(struct con_driver *con)
  * RETURNS: zero if unbound, nonzero if bound
  *
  * Drivers can call this and if zero, they should release
- * all resources allocated on con_startup()
+ * all resources allocated on &consw.con_startup()
  */
 int con_is_bound(const struct consw *csw)
 {
@@ -3970,15 +4160,9 @@ EXPORT_SYMBOL(con_is_visible);
  * Called when the console is taken over by the kernel debugger, this
  * function needs to save the current console state, then put the console
  * into a state suitable for the kernel debugger.
- *
- * RETURNS:
- * Zero on success, nonzero if a failure occurred when trying to prepare
- * the console for the debugger.
  */
-int con_debug_enter(struct vc_data *vc)
+void con_debug_enter(struct vc_data *vc)
 {
-	int ret = 0;
-
 	saved_fg_console = fg_console;
 	saved_last_console = last_console;
 	saved_want_console = want_console;
@@ -3987,7 +4171,7 @@ int con_debug_enter(struct vc_data *vc)
 	vc->vc_mode = KD_TEXT;
 	console_blanked = 0;
 	if (vc->vc_sw->con_debug_enter)
-		ret = vc->vc_sw->con_debug_enter(vc);
+		vc->vc_sw->con_debug_enter(vc);
 #ifdef CONFIG_KGDB_KDB
 	/* Set the initial LINES variable if it is not already set */
 	if (vc->vc_rows < 999) {
@@ -4017,7 +4201,6 @@ int con_debug_enter(struct vc_data *vc)
 		}
 	}
 #endif /* CONFIG_KGDB_KDB */
-	return ret;
 }
 EXPORT_SYMBOL_GPL(con_debug_enter);
 
@@ -4026,15 +4209,10 @@ EXPORT_SYMBOL_GPL(con_debug_enter);
  *
  * Restore the console state to what it was before the kernel debugger
  * was invoked.
- *
- * RETURNS:
- * Zero on success, nonzero if a failure occurred when trying to restore
- * the console.
  */
-int con_debug_leave(void)
+void con_debug_leave(void)
 {
 	struct vc_data *vc;
-	int ret = 0;
 
 	fg_console = saved_fg_console;
 	last_console = saved_last_console;
@@ -4044,8 +4222,7 @@ int con_debug_leave(void)
 
 	vc = vc_cons[fg_console].d;
 	if (vc->vc_sw->con_debug_leave)
-		ret = vc->vc_sw->con_debug_leave(vc);
-	return ret;
+		vc->vc_sw->con_debug_leave(vc);
 }
 EXPORT_SYMBOL_GPL(con_debug_leave);
 
@@ -4275,14 +4452,17 @@ postcore_initcall(vtconsole_class_init);
  *	Screen blanking
  */
 
-static int set_vesa_blanking(char __user *p)
+static int set_vesa_blanking(u8 __user *mode_user)
 {
-	unsigned int mode;
+	u8 mode;
 
-	if (get_user(mode, p + 1))
+	if (get_user(mode, mode_user))
 		return -EFAULT;
 
-	vesa_blank_mode = (mode < 4) ? mode : 0;
+	console_lock();
+	vesa_blank_mode = (mode <= VESA_BLANK_MAX) ? mode : VESA_NO_BLANKING;
+	console_unlock();
+
 	return 0;
 }
 
@@ -4307,7 +4487,7 @@ void do_blank_screen(int entering_gfx)
 	if (entering_gfx) {
 		hide_cursor(vc);
 		save_screen(vc);
-		vc->vc_sw->con_blank(vc, -1, 1);
+		vc->vc_sw->con_blank(vc, VESA_VSYNC_SUSPEND, 1);
 		console_blanked = fg_console + 1;
 		blank_state = blank_off;
 		set_origin(vc);
@@ -4328,7 +4508,8 @@ void do_blank_screen(int entering_gfx)
 
 	save_screen(vc);
 	/* In case we need to reset origin, blanking hook returns 1 */
-	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
+	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? VESA_VSYNC_SUSPEND :
+				 (vesa_blank_mode + 1), 0);
 	console_blanked = fg_console + 1;
 	if (i)
 		set_origin(vc);
@@ -4379,7 +4560,7 @@ void do_unblank_screen(int leaving_gfx)
 	}
 
 	console_blanked = 0;
-	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
+	if (vc->vc_sw->con_blank(vc, VESA_NO_BLANKING, leaving_gfx))
 		/* Low-level driver cannot restore -> do it ourselves */
 		update_screen(vc);
 	if (console_blank_hook)
@@ -4584,7 +4765,7 @@ out:
 	return rc;
 }
 
-static int con_font_set(struct vc_data *vc, struct console_font_op *op)
+static int con_font_set(struct vc_data *vc, const struct console_font_op *op)
 {
 	struct console_font font;
 	int rc = -EINVAL;
@@ -4748,43 +4929,3 @@ void vcs_scr_updated(struct vc_data *vc)
 {
 	notify_update(vc);
 }
-
-void vc_scrolldelta_helper(struct vc_data *c, int lines,
-		unsigned int rolled_over, void *base, unsigned int size)
-{
-	unsigned long ubase = (unsigned long)base;
-	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
-	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
-	ptrdiff_t origin = (void *)c->vc_origin - base;
-	int margin = c->vc_size_row * 4;
-	int from, wrap, from_off, avail;
-
-	/* Turn scrollback off */
-	if (!lines) {
-		c->vc_visible_origin = c->vc_origin;
-		return;
-	}
-
-	/* Do we have already enough to allow jumping from 0 to the end? */
-	if (rolled_over > scr_end + margin) {
-		from = scr_end;
-		wrap = rolled_over + c->vc_size_row;
-	} else {
-		from = 0;
-		wrap = size;
-	}
-
-	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
-	avail = (origin - from + wrap) % wrap;
-
-	/* Only a little piece would be left? Show all incl. the piece! */
-	if (avail < 2 * margin)
-		margin = 0;
-	if (from_off < margin)
-		from_off = 0;
-	if (from_off > avail - margin)
-		from_off = avail;
-
-	c->vc_visible_origin = ubase + (from + from_off) % wrap;
-}
-EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
index 8c685b5014..4b91072f3a 100644
--- a/drivers/tty/vt/vt_ioctl.c
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -714,8 +714,7 @@ static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs)
 				vcp->vc_scan_lines = v.v_vlin;
 			if (v.v_clin)
 				vcp->vc_cell_height = v.v_clin;
-			vcp->vc_resize_user = 1;
-			ret = vc_resize(vcp, v.v_cols, v.v_rows);
+			ret = __vc_resize(vcp, v.v_cols, v.v_rows, true);
 			if (ret) {
 				vcp->vc_scan_lines = save_scan_lines;
 				vcp->vc_cell_height = save_cell_height;
@@ -923,9 +922,8 @@ int vt_ioctl(struct tty_struct *tty,
 			vc = vc_cons[i].d;
 
 			if (vc) {
-				vc->vc_resize_user = 1;
 				/* FIXME: review v tty lock */
-				vc_resize(vc_cons[i].d, cc, ll);
+				__vc_resize(vc_cons[i].d, cc, ll, true);
 			}
 		}
 		console_unlock();