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Commit bcd375f7 authored by Manuel Schölling's avatar Manuel Schölling Committed by Greg Kroah-Hartman
Browse files

console: Add callback to flush scrollback buffer to consw struct 



This new callback is in preparation for persistent scrollback buffer
support for VGA consoles.
With a single scrollback buffer for all consoles, we could flush the
buffer just by invocating consw->con_switch(). But when each VGA console
has its own scrollback buffer, we need a new callback to tell the
video console driver which buffer to flush.

Signed-off-by: default avatarManuel Schölling <manuel.schoelling@gmx.de>
Reviewed-by: default avatarAndrey Utkin <andrey_utkin@fastmail.com>
Tested-by: default avatarAndrey Utkin <andrey_utkin@fastmail.com>
Tested-by: default avatarAdam Borowski <kilobyte@angband.pl>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 66da39eb

drivers/tty/vt/vt.c

+9 −0
Original line number Diff line number Diff line
@@ -625,6 +625,14 @@ static void save_screen(struct vc_data *vc) 
		vc->vc_sw->con_save_screen(vc);

}



static void flush_scrollback(struct vc_data *vc)

{

	WARN_CONSOLE_UNLOCKED();



	if (vc->vc_sw->con_flush_scrollback)

		vc->vc_sw->con_flush_scrollback(vc);

}



/*

 *	Redrawing of screen

 */
@@ -1171,6 +1179,7 @@ static void csi_J(struct vc_data *vc, int vpar) 
		case 3: /* erase scroll-back buffer (and whole display) */

			scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,

				    vc->vc_screenbuf_size);

			flush_scrollback(vc);

			set_origin(vc);

			if (con_is_visible(vc))

				update_screen(vc);

drivers/video/console/vgacon.c

+23 −1
Original line number Diff line number Diff line
@@ -173,6 +173,16 @@ static struct vgacon_scrollback_info { 
	int restore;

} vgacon_scrollback;



static void vgacon_scrollback_reset(size_t reset_size)

{

	if (vgacon_scrollback.data && reset_size > 0)

		memset(vgacon_scrollback.data, 0, reset_size);



	vgacon_scrollback.cnt  = 0;

	vgacon_scrollback.tail = 0;

	vgacon_scrollback.cur  = 0;

}



static void vgacon_scrollback_init(int pitch)

{

	int rows = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024/pitch;
@@ -305,6 +315,14 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines) 
	} else

		vgacon_cursor(c, CM_MOVE);

}



static void vgacon_flush_scrollback(struct vc_data *c)

{

	size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;



	if (c->vc_num == fg_console)

		vgacon_scrollback_reset(size);

}

#else

#define vgacon_scrollback_startup(...) do { } while (0)

#define vgacon_scrollback_init(...)    do { } while (0)
@@ -322,6 +340,10 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines) 
			vga_vram_size);

	vga_set_mem_top(c);

}



static void vgacon_flush_scrollback(struct vc_data *c)

{

}

#endif /* CONFIG_VGACON_SOFT_SCROLLBACK */



static const char *vgacon_startup(void)
@@ -1329,7 +1351,6 @@ static bool vgacon_scroll(struct vc_data *c, unsigned int t, unsigned int b, 
	return true;

}





/*

 *  The console `switch' structure for the VGA based console

 */
@@ -1362,6 +1383,7 @@ const struct consw vga_con = { 
	.con_save_screen = vgacon_save_screen,

	.con_build_attr = vgacon_build_attr,

	.con_invert_region = vgacon_invert_region,

	.con_flush_scrollback = vgacon_flush_scrollback,

};

EXPORT_SYMBOL(vga_con);

include/linux/console.h

+4 −0
Original line number Diff line number Diff line
@@ -72,6 +72,10 @@ struct consw { 
	void	(*con_invert_region)(struct vc_data *, u16 *, int);

	u16    *(*con_screen_pos)(struct vc_data *, int);

	unsigned long (*con_getxy)(struct vc_data *, unsigned long, int *, int *);

	/*

	 * Flush the video console driver's scrollback buffer

	 */

	void	(*con_flush_scrollback)(struct vc_data *);

	/*

	 * Prepare the console for the debugger.  This includes, but is not

	 * limited to, unblanking the console, loading an appropriate