vc: separate state

There are two copies of some members of struct vc_data. This is because
we need to save them and restore later. Move these memebers to a
separate structure called vc_state. So now instead of members like:
  vc_x, vc_y and vc_saved_x, vc_saved_y
we have
  state and saved_state (of type: struct vc_state)
containing
  state.x, state.y and saved_state.x, saved_state.y

This change:
* makes clear what is saved & restored
* eases save & restore by using memcpy (see save_cur and restore_cur)

Finally, we document the newly added struct vc_state using kernel-doc.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 33 insertions, 21 deletions

diff --git a/include/linux/console_struct.h b/include/linux/console_struct.h
index 24d4c16e3ae0..162f4337c767 100644
--- a/include/linux/console_struct.h
+++ b/include/linux/console_struct.h
@@ -22,6 +22,37 @@ struct uni_screen;
 
 #define NPAR 16
 
+/**
+ * struct vc_state -- state of a VC
+ * @x: cursor's x-position
+ * @y: cursor's y-position
+ * @color: foreground & background colors
+ * @G0_charset: what's G0 slot set to (like GRAF_MAP, LAT1_MAP)
+ * @G1_charset: what's G1 slot set to (like GRAF_MAP, LAT1_MAP)
+ * @charset: what character set to use (0=G0 or 1=G1)
+ * @intensity: 0=half-bright, 1=normal, 2=bold
+ * @reverse: reversed foreground/background colors
+ *
+ * These members are defined separately from struct vc_data as we save &
+ * restore them at times.
+ */
+struct vc_state {
+	unsigned int	x, y;
+
+	unsigned char	color;
+
+	unsigned char	G0_charset;
+	unsigned char	G1_charset;
+	unsigned int	charset		: 1;
+
+	/* attribute flags */
+	unsigned int	intensity	: 2;
+	unsigned int	italic		: 1;
+	unsigned int	underline	: 1;
+	unsigned int	blink		: 1;
+	unsigned int	reverse		: 1;
+};
+
 /*
  * Example: vc_data of a console that was scrolled 3 lines down.
  *
@@ -57,6 +88,8 @@ struct uni_screen;
 struct vc_data {
 	struct tty_port port;			/* Upper level data */
 
+	struct vc_state state, saved_state;
+
 	unsigned short	vc_num;			/* Console number */
 	unsigned int	vc_cols;		/* [#] Console size */
 	unsigned int	vc_rows;
@@ -73,8 +106,6 @@ struct vc_data {
 	/* attributes for all characters on screen */
 	unsigned char	vc_attr;		/* Current attributes */
 	unsigned char	vc_def_color;		/* Default colors */
-	unsigned char	vc_color;		/* Foreground & background */
-	unsigned char	vc_s_color;		/* Saved foreground & background */
 	unsigned char	vc_ulcolor;		/* Color for underline mode */
 	unsigned char   vc_itcolor;
 	unsigned char	vc_halfcolor;		/* Color for half intensity mode */
@@ -82,8 +113,6 @@ struct vc_data {
 	unsigned int	vc_cursor_type;
 	unsigned short	vc_complement_mask;	/* [#] Xor mask for mouse pointer */
 	unsigned short	vc_s_complement_mask;	/* Saved mouse pointer mask */
-	unsigned int	vc_x, vc_y;		/* Cursor position */
-	unsigned int	vc_saved_x, vc_saved_y;
 	unsigned long	vc_pos;			/* Cursor address */
 	/* fonts */	
 	unsigned short	vc_hi_font_mask;	/* [#] Attribute set for upper 256 chars of font or 0 if not supported */
@@ -98,8 +127,6 @@ struct vc_data {
 	int		vt_newvt;
 	wait_queue_head_t paste_wait;
 	/* mode flags */
-	unsigned int	vc_charset	: 1;	/* Character set G0 / G1 */
-	unsigned int	vc_s_charset	: 1;	/* Saved character set */
 	unsigned int	vc_disp_ctrl	: 1;	/* Display chars < 32? */
 	unsigned int	vc_toggle_meta	: 1;	/* Toggle high bit? */
 	unsigned int	vc_decscnm	: 1;	/* Screen Mode */
@@ -107,17 +134,6 @@ struct vc_data {
 	unsigned int	vc_decawm	: 1;	/* Autowrap Mode */
 	unsigned int	vc_deccm	: 1;	/* Cursor Visible */
 	unsigned int	vc_decim	: 1;	/* Insert Mode */
-	/* attribute flags */
-	unsigned int	vc_intensity	: 2;	/* 0=half-bright, 1=normal, 2=bold */
-	unsigned int    vc_italic:1;
-	unsigned int	vc_underline	: 1;
-	unsigned int	vc_blink	: 1;
-	unsigned int	vc_reverse	: 1;
-	unsigned int	vc_s_intensity	: 2;	/* saved rendition */
-	unsigned int    vc_s_italic:1;
-	unsigned int	vc_s_underline	: 1;
-	unsigned int	vc_s_blink	: 1;
-	unsigned int	vc_s_reverse	: 1;
 	/* misc */
 	unsigned int	vc_priv		: 3;
 	unsigned int	vc_need_wrap	: 1;
@@ -129,10 +145,6 @@ struct vc_data {
 	unsigned int	vc_tab_stop[8];		/* Tab stops. 256 columns. */
 	unsigned char   vc_palette[16*3];       /* Colour palette for VGA+ */
 	unsigned short * vc_translate;
-	unsigned char 	vc_G0_charset;
-	unsigned char 	vc_G1_charset;
-	unsigned char 	vc_saved_G0;
-	unsigned char 	vc_saved_G1;
 	unsigned int    vc_resize_user;         /* resize request from user */
 	unsigned int	vc_bell_pitch;		/* Console bell pitch */
 	unsigned int	vc_bell_duration;	/* Console bell duration */