vt.c

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/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

/*
 * Hopefully this will be a rather complete VT102 implementation.
 *
 * Beeping thanks to John T Kohl.
 *
 * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
 *   Chars, and VT100 enhancements by Peter MacDonald.
 *
 * Copy and paste function by Andrew Haylett,
 *   some enhancements by Alessandro Rubini.
 *
 * Code to check for different video-cards mostly by Galen Hunt,
 * <[email protected]>
 *
 * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
 * Markus Kuhn, <[email protected]>.
 *
 * Dynamic allocation of consoles, [email protected], May 1994
 * Resizing of consoles, aeb, 940926
 *
 * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
 * <[email protected]>
 *
 * User-defined bell sound, new setterm control sequences and printk
 * redirection by Martin Mares <[email protected]> 19-Nov-95
 *
 * APM screenblank bug fixed Takashi Manabe <[email protected]>
 *
 * Merge with the abstract console driver by Geert Uytterhoeven
 * <[email protected]>, Jan 1997.
 *
 *   Original m68k console driver modifications by
 *
 *     - Arno Griffioen <[email protected]>
 *     - David Carter <[email protected]>
 * 
 *   The abstract console driver provides a generic interface for a text
 *   console. It supports VGA text mode, frame buffer based graphical consoles
 *   and special graphics processors that are only accessible through some
 *   registers (e.g. a TMS340x0 GSP).
 *
 *   The interface to the hardware is specified using a special structure
 *   (struct consw) which contains function pointers to console operations
 *   (see <linux/console.h> for more information).
 *
 * Support for changeable cursor shape
 * by Pavel Machek <[email protected]>, August 1997
 *
 * Ported to i386 and con_scrolldelta fixed
 * by Emmanuel Marty <[email protected]>, April 1998
 *
 * Resurrected character buffers in videoram plus lots of other trickery
 * by Martin Mares <[email protected]>, July 1998
 *
 * Removed old-style timers, introduced console_timer, made timer
 * deletion SMP-safe.  17Jun00, Andrew Morton
 *
 * Removed console_lock, enabled interrupts across all console operations
 * 13 March 2001, Andrew Morton
 *
 * Fixed UTF-8 mode so alternate charset modes always work according
 * to control sequences interpreted in do_con_trol function
 * preserving backward VT100 semigraphics compatibility,
 * malformed UTF sequences represented as sequences of replacement glyphs,
 * original codes or '?' as a last resort if replacement glyph is undefined
 * by Adam Tla/lka <[email protected]>, Aug 2006
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/kd.h>
#include <linux/slab.h>
#include <linux/major.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/vt_kern.h>
#include <linux/selection.h>
#include <linux/tiocl.h>
#include <linux/kbd_kern.h>
#include <linux/consolemap.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/pm.h>
#include <linux/font.h>
#include <linux/bitops.h>
#include <linux/notifier.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/kdb.h>
#include <linux/ctype.h>

#define MAX_NR_CON_DRIVER 16

#define CON_DRIVER_FLAG_MODULE 1
#define CON_DRIVER_FLAG_INIT   2
#define CON_DRIVER_FLAG_ATTR   4

struct con_driver {
    const struct consw *con;
    const char *desc;
    struct device *dev;
    int node;
    int first;
    int last;
    int flag;
};

static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
const struct consw *conswitchp;

/* A bitmap for codes <32. A bit of 1 indicates that the code
 * corresponding to that bit number invokes some special action
 * (such as cursor movement) and should not be displayed as a
 * glyph unless the disp_ctrl mode is explicitly enabled.
 */
#define CTRL_ACTION 0x0d00ff81
#define CTRL_ALWAYS 0x0800f501  /* Cannot be overridden by disp_ctrl */

/*
 * Here is the default bell parameters: 750HZ, 1/8th of a second
 */
#define DEFAULT_BELL_PITCH  750
#define DEFAULT_BELL_DURATION   (HZ/8)

struct vc vc_cons [MAX_NR_CONSOLES];

#ifndef VT_SINGLE_DRIVER
static const struct consw *con_driver_map[MAX_NR_CONSOLES];
#endif

static int con_open(struct tty_struct *, struct file *);
static void vc_init(struct vc_data *vc, unsigned int rows,
            unsigned int cols, int do_clear);
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 void set_cursor(struct vc_data *vc);
static void hide_cursor(struct vc_data *vc);
static void console_callback(struct work_struct *ignored);
static void blank_screen_t(unsigned long dummy);
static void set_palette(struct vc_data *vc);

static int printable;       /* Is console ready for printing? */
int default_utf8 = true;
module_param(default_utf8, int, S_IRUGO | S_IWUSR);
int global_cursor_default = -1;
module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);

static int cur_default = CUR_DEFAULT;
module_param(cur_default, int, S_IRUGO | S_IWUSR);

/*
 * ignore_poke: don't unblank the screen when things are typed.  This is
 * mainly for the privacy of braille terminal users.
 */
static int ignore_poke;

int do_poke_blanked_console;
int console_blanked;

static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
static int vesa_off_interval;
static int blankinterval = 10*60;
core_param(consoleblank, blankinterval, int, 0444);

static DECLARE_WORK(console_work, console_callback);

/*
 * fg_console is the current virtual console,
 * last_console is the last used one,
 * want_console is the console we want to switch to,
 * saved_* variants are for save/restore around kernel debugger enter/leave
 */
int fg_console;
int last_console;
int want_console = -1;
static int saved_fg_console;
static int saved_last_console;
static int saved_want_console;
static int saved_vc_mode;
static int saved_console_blanked;

/*
 * For each existing display, we have a pointer to console currently visible
 * on that display, allowing consoles other than fg_console to be refreshed
 * appropriately. Unless the low-level driver supplies its own display_fg
 * variable, we use this one for the "master display".
 */
static struct vc_data *master_display_fg;

/*
 * Unfortunately, we need to delay tty echo when we're currently writing to the
 * console since the code is (and always was) not re-entrant, so we schedule
 * all flip requests to process context with schedule-task() and run it from
 * console_callback().
 */

/*
 * For the same reason, we defer scrollback to the console callback.
 */
static int scrollback_delta;

/*
 * Hook so that the power management routines can (un)blank
 * the console on our behalf.
 */
int (*console_blank_hook)(int);

static DEFINE_TIMER(console_timer, blank_screen_t, 0, 0);
static int blank_state;
static int blank_timer_expired;
enum {
    blank_off = 0,
    blank_normal_wait,
    blank_vesa_wait,
};

/*
 * /sys/class/tty/tty0/
 *
 * the attribute 'active' contains the name of the current vc
 * console and it supports poll() to detect vc switches
 */
static struct device *tty0dev;

/*
 * Notifier list for console events.
 */
static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);

int register_vt_notifier(struct notifier_block *nb)
{
    return atomic_notifier_chain_register(&vt_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(register_vt_notifier);

int unregister_vt_notifier(struct notifier_block *nb)
{
    return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(unregister_vt_notifier);

static void notify_write(struct vc_data *vc, unsigned int unicode)
{
    struct vt_notifier_param param = { .vc = vc, .c = unicode };
    atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
}

static void notify_update(struct vc_data *vc)
{
    struct vt_notifier_param param = { .vc = vc };
    atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
}
/*
 *  Low-Level Functions
 */

#define IS_FG(vc)   ((vc)->vc_num == fg_console)

#ifdef VT_BUF_VRAM_ONLY
#define DO_UPDATE(vc)   0
#else
#define DO_UPDATE(vc)   (CON_IS_VISIBLE(vc) && !console_blanked)
#endif

static inline unsigned short *screenpos(struct vc_data *vc, int offset, int 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);
    else
        p = vc->vc_sw->con_screen_pos(vc, offset);
    return p;
}

/* Called  from the keyboard irq path.. */
static inline void scrolldelta(int lines)
{
    /* FIXME */
    /* scrolldelta needs some kind of consistency lock, but the BKL was
       and still is not protecting versus the scheduled back end */
    scrollback_delta += lines;
    schedule_console_callback();
}

void schedule_console_callback(void)
{
    schedule_work(&console_work);
}

static void scrup(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
{
    unsigned short *d, *s;

    if (t+nr >= b)
        nr = b - t - 1;
    if (b > vc->vc_rows || t >= b || nr < 1)
        return;
    if (CON_IS_VISIBLE(vc) && vc->vc_sw->con_scroll(vc, t, b, SM_UP, nr))
        return;
    d = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
    s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * (t + nr));
    scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
    scr_memsetw(d + (b - t - nr) * vc->vc_cols, vc->vc_video_erase_char,
            vc->vc_size_row * nr);
}

static void scrdown(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
{
    unsigned short *s;
    unsigned int step;

    if (t+nr >= b)
        nr = b - t - 1;
    if (b > vc->vc_rows || t >= b || nr < 1)
        return;
    if (CON_IS_VISIBLE(vc) && vc->vc_sw->con_scroll(vc, t, b, SM_DOWN, nr))
        return;
    s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
    step = vc->vc_cols * nr;
    scr_memmovew(s + step, s, (b - t - nr) * vc->vc_size_row);
    scr_memsetw(s, vc->vc_video_erase_char, 2 * step);
}

static void do_update_region(struct vc_data *vc, unsigned long start, int count)
{
#ifndef VT_BUF_VRAM_ONLY
    unsigned int xx, yy, offset;
    u16 *p;

    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;
        u16 *q = p;
        while (xx < vc->vc_cols && count) {
            if (attrib != (scr_readw(p) & 0xff00)) {
                if (p > q)
                    vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
                startx = xx;
                q = p;
                attrib = scr_readw(p) & 0xff00;
            }
            p++;
            xx++;
            count--;
        }
        if (p > q)
            vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
        if (!count)
            break;
        xx = 0;
        yy++;
        if (vc->vc_sw->con_getxy) {
            p = (u16 *)start;
            start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
        }
    }
#endif
}

void update_region(struct vc_data *vc, unsigned long start, int count)
{
    WARN_CONSOLE_UNLOCKED();

    if (DO_UPDATE(vc)) {
        hide_cursor(vc);
        do_update_region(vc, start, count);
        set_cursor(vc);
    }
}

/* Structure of attributes is hardware-dependent */

static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
    u8 _underline, u8 _reverse, u8 _italic)
{
    if (vc->vc_sw->con_build_attr)
        return vc->vc_sw->con_build_attr(vc, _color, _intensity,
               _blink, _underline, _reverse, _italic);

#ifndef VT_BUF_VRAM_ONLY
/*
 * ++roman: I completely changed the attribute format for monochrome
 * mode (!can_do_color). The formerly used MDA (monochrome display
 * adapter) format didn't allow the combination of certain effects.
 * Now the attribute is just a bit vector:
 *  Bit 0..1: intensity (0..2)
 *  Bit 2   : underline
 *  Bit 3   : reverse
 *  Bit 7   : blink
 */
    {
    u8 a = _color;
    if (!vc->vc_can_do_color)
        return _intensity |
               (_italic ? 2 : 0) |
               (_underline ? 4 : 0) |
               (_reverse ? 8 : 0) |
               (_blink ? 0x80 : 0);
    if (_italic)
        a = (a & 0xF0) | vc->vc_itcolor;
    else if (_underline)
        a = (a & 0xf0) | vc->vc_ulcolor;
    else if (_intensity == 0)
        a = (a & 0xf0) | vc->vc_ulcolor;
    if (_reverse)
        a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
    if (_blink)
        a ^= 0x80;
    if (_intensity == 2)
        a ^= 0x08;
    if (vc->vc_hi_font_mask == 0x100)
        a <<= 1;
    return a;
    }
#else
    return 0;
#endif
}

static void update_attr(struct vc_data *vc)
{
    vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
                  vc->vc_blink, vc->vc_underline,
                  vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
    vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
}

/* Note: inverting the screen twice should revert to the original state */
void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
{
    unsigned short *p;

    WARN_CONSOLE_UNLOCKED();

    count /= 2;
    p = screenpos(vc, offset, viewed);
    if (vc->vc_sw->con_invert_region)
        vc->vc_sw->con_invert_region(vc, p, count);
#ifndef VT_BUF_VRAM_ONLY
    else {
        u16 *q = p;
        int cnt = count;
        u16 a;

        if (!vc->vc_can_do_color) {
            while (cnt--) {
                a = scr_readw(q);
                a ^= 0x0800;
                scr_writew(a, q);
                q++;
            }
        } else if (vc->vc_hi_font_mask == 0x100) {
            while (cnt--) {
                a = scr_readw(q);
                a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
                scr_writew(a, q);
                q++;
            }
        } else {
            while (cnt--) {
                a = scr_readw(q);
                a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
                scr_writew(a, q);
                q++;
            }
        }
    }
#endif
    if (DO_UPDATE(vc))
        do_update_region(vc, (unsigned long) p, count);
}

/* used by selection: complement pointer position */
void complement_pos(struct vc_data *vc, int offset)
{
    static int old_offset = -1;
    static unsigned short old;
    static unsigned short oldx, oldy;

    WARN_CONSOLE_UNLOCKED();

    if (old_offset != -1 && old_offset >= 0 &&
        old_offset < vc->vc_screenbuf_size) {
        scr_writew(old, screenpos(vc, old_offset, 1));
        if (DO_UPDATE(vc))
            vc->vc_sw->con_putc(vc, old, oldy, oldx);
    }

    old_offset = offset;

    if (offset != -1 && offset >= 0 &&
        offset < vc->vc_screenbuf_size) {
        unsigned short new;
        unsigned short *p;
        p = screenpos(vc, offset, 1);
        old = scr_readw(p);
        new = old ^ vc->vc_complement_mask;
        scr_writew(new, p);
        if (DO_UPDATE(vc)) {
            oldx = (offset >> 1) % vc->vc_cols;
            oldy = (offset >> 1) / vc->vc_cols;
            vc->vc_sw->con_putc(vc, new, oldy, oldx);
        }
    }

}

static void insert_char(struct vc_data *vc, unsigned int nr)
{
    unsigned short *p = (unsigned short *) vc->vc_pos;

    scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x) * 2);
    scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
    vc->vc_need_wrap = 0;
    if (DO_UPDATE(vc))
        do_update_region(vc, (unsigned long) p,
            vc->vc_cols - vc->vc_x);
}

static void delete_char(struct vc_data *vc, unsigned int nr)
{
    unsigned short *p = (unsigned short *) vc->vc_pos;

    scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
    scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
            nr * 2);
    vc->vc_need_wrap = 0;
    if (DO_UPDATE(vc))
        do_update_region(vc, (unsigned long) p,
            vc->vc_cols - vc->vc_x);
}

static int softcursor_original;

static void add_softcursor(struct vc_data *vc)
{
    int i = scr_readw((u16 *) vc->vc_pos);
    u32 type = vc->vc_cursor_type;

    if (! (type & 0x10)) return;
    if (softcursor_original != -1) return;
    softcursor_original = i;
    i |= ((type >> 8) & 0xff00 );
    i ^= ((type) & 0xff00 );
    if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
    if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
    scr_writew(i, (u16 *) vc->vc_pos);
    if (DO_UPDATE(vc))
        vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
}

static void hide_softcursor(struct vc_data *vc)
{
    if (softcursor_original != -1) {
        scr_writew(softcursor_original, (u16 *)vc->vc_pos);
        if (DO_UPDATE(vc))
            vc->vc_sw->con_putc(vc, softcursor_original,
                    vc->vc_y, vc->vc_x);
        softcursor_original = -1;
    }
}

static void hide_cursor(struct vc_data *vc)
{
    if (vc == sel_cons)
        clear_selection();
    vc->vc_sw->con_cursor(vc, CM_ERASE);
    hide_softcursor(vc);
}

static void set_cursor(struct vc_data *vc)
{
    if (!IS_FG(vc) || console_blanked ||
        vc->vc_mode == KD_GRAPHICS)
        return;
    if (vc->vc_deccm) {
        if (vc == sel_cons)
            clear_selection();
        add_softcursor(vc);
        if ((vc->vc_cursor_type & 0x0f) != 1)
            vc->vc_sw->con_cursor(vc, CM_DRAW);
    } else
        hide_cursor(vc);
}

static void set_origin(struct vc_data *vc)
{
    WARN_CONSOLE_UNLOCKED();

    if (!CON_IS_VISIBLE(vc) ||
        !vc->vc_sw->con_set_origin ||
        !vc->vc_sw->con_set_origin(vc))
        vc->vc_origin = (unsigned long)vc->vc_screenbuf;
    vc->vc_visible_origin = vc->vc_origin;
    vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
    vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
}

static inline void save_screen(struct vc_data *vc)
{
    WARN_CONSOLE_UNLOCKED();

    if (vc->vc_sw->con_save_screen)
        vc->vc_sw->con_save_screen(vc);
}

/*
 *  Redrawing of screen
 */

static void clear_buffer_attributes(struct vc_data *vc)
{
    unsigned short *p = (unsigned short *)vc->vc_origin;
    int count = vc->vc_screenbuf_size / 2;
    int mask = vc->vc_hi_font_mask | 0xff;

    for (; count > 0; count--, p++) {
        scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
    }
}

void redraw_screen(struct vc_data *vc, int is_switch)
{
    int redraw = 0;

    WARN_CONSOLE_UNLOCKED();

    if (!vc) {
        /* strange ... */
        /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
        return;
    }

    if (is_switch) {
        struct vc_data *old_vc = vc_cons[fg_console].d;
        if (old_vc == vc)
            return;
        if (!CON_IS_VISIBLE(vc))
            redraw = 1;
        *vc->vc_display_fg = vc;
        fg_console = vc->vc_num;
        hide_cursor(old_vc);
        if (!CON_IS_VISIBLE(old_vc)) {
            save_screen(old_vc);
            set_origin(old_vc);
        }
        if (tty0dev)
            sysfs_notify(&tty0dev->kobj, NULL, "active");
    } else {
        hide_cursor(vc);
        redraw = 1;
    }

    if (redraw) {
        int update;
        int old_was_color = vc->vc_can_do_color;

        set_origin(vc);
        update = vc->vc_sw->con_switch(vc);
        set_palette(vc);
        /*
         * If console changed from mono<->color, the best we can do
         * is to clear the buffer attributes. As it currently stands,
         * rebuilding new attributes from the old buffer is not doable
         * without overly complex code.
         */
        if (old_was_color != vc->vc_can_do_color) {
            update_attr(vc);
            clear_buffer_attributes(vc);
        }

        /* Forcibly update if we're panicing */
        if ((update && vc->vc_mode != KD_GRAPHICS) ||
            vt_force_oops_output(vc))
            do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
    }
    set_cursor(vc);
    if (is_switch) {
        set_leds();
        compute_shiftstate();
        notify_update(vc);
    }
}

/*
 *  Allocation, freeing and resizing of VTs.
 */

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)
{
    /* ++Geert: vc->vc_sw->con_init determines console size */
    if (vc->vc_sw)
        module_put(vc->vc_sw->owner);
    vc->vc_sw = conswitchp;
#ifndef VT_SINGLE_DRIVER
    if (con_driver_map[num])
        vc->vc_sw = con_driver_map[num];
#endif
    __module_get(vc->vc_sw->owner);
    vc->vc_num = num;
    vc->vc_display_fg = &master_display_fg;
    vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
    vc->vc_uni_pagedir = 0;
    vc->vc_hi_font_mask = 0;
    vc->vc_complement_mask = 0;
    vc->vc_can_do_color = 0;
    vc->vc_panic_force_write = false;
    vc->vc_sw->con_init(vc, init);
    if (!vc->vc_complement_mask)
        vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
    vc->vc_s_complement_mask = vc->vc_complement_mask;
    vc->vc_size_row = vc->vc_cols << 1;
    vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
}

int vc_allocate(unsigned int currcons)  /* return 0 on success */
{
    WARN_CONSOLE_UNLOCKED();

    if (currcons >= MAX_NR_CONSOLES)
        return -ENXIO;
    if (!vc_cons[currcons].d) {
        struct vc_data *vc;
        struct vt_notifier_param param;

        /* prevent users from taking too much memory */
        if (currcons >= MAX_NR_USER_CONSOLES && !capable(CAP_SYS_RESOURCE))
          return -EPERM;

        /* due to the granularity of kmalloc, we waste some memory here */
        /* the alloc is done in two steps, to optimize the common situation
           of a 25x80 console (structsize=216, screenbuf_size=4000) */
        /* although the numbers above are not valid since long ago, the
           point is still up-to-date and the comment still has its value
           even if only as a historical artifact.  --mj, July 1998 */
        param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
        if (!vc)
        return -ENOMEM;
        vc_cons[currcons].d = vc;
        tty_port_init(&vc->port);
        INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
        visual_init(vc, currcons, 1);
        if (!*vc->vc_uni_pagedir_loc)
        con_set_default_unimap(vc);
        vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
        if (!vc->vc_screenbuf) {
        kfree(vc);
        vc_cons[currcons].d = NULL;
        return -ENOMEM;
        }

        /* If no drivers have overridden us and the user didn't pass a
           boot option, default to displaying the cursor */
        if (global_cursor_default == -1)
            global_cursor_default = 1;

        vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
        vcs_make_sysfs(currcons);
        atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
    }
    return 0;
}

static inline int resize_screen(struct vc_data *vc, int width, int height,
                int user)
{
    /* Resizes the resolution of the display adapater */
    int err = 0;

    if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
        err = vc->vc_sw->con_resize(vc, width, height, user);

    return err;
}

/*
 * Change # of rows and columns (0 means unchanged/the size of fg_console)
 * [this is to be used together with some user program
 * like resize that changes the hardware videomode]
 */
#define VC_RESIZE_MAXCOL (32767)
#define VC_RESIZE_MAXROW (32767)

static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
                unsigned int cols, unsigned int lines)
{
    unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
    unsigned long end;
    unsigned int old_rows, old_row_size;
    unsigned int new_cols, new_rows, new_row_size, new_screen_size;
    unsigned int user;
    unsigned short *newscreen;

    WARN_CONSOLE_UNLOCKED();

    if (!vc)
        return -ENXIO;

    user = vc->vc_resize_user;
    vc->vc_resize_user = 0;

    if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
        return -EINVAL;

    new_cols = (cols ? cols : vc->vc_cols);
    new_rows = (lines ? lines : vc->vc_rows);
    new_row_size = new_cols << 1;
    new_screen_size = new_row_size * new_rows;

    if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
        return 0;

    newscreen = kmalloc(new_screen_size, GFP_USER);
    if (!newscreen)
        return -ENOMEM;

    old_rows = vc->vc_rows;
    old_row_size = vc->vc_size_row;

    err = resize_screen(vc, new_cols, new_rows, user);
    if (err) {
        kfree(newscreen);
        return err;
    }

    vc->vc_rows = new_rows;
    vc->vc_cols = new_cols;
    vc->vc_size_row = new_row_size;
    vc->vc_screenbuf_size = new_screen_size;

    rlth = min(old_row_size, new_row_size);
    rrem = new_row_size - rlth;
    old_origin = vc->vc_origin;
    new_origin = (long) newscreen;
    new_scr_end = new_origin + new_screen_size;

    if (vc->vc_y > new_rows) {
        if (old_rows - vc->vc_y < new_rows) {
            /*
             * Cursor near the bottom, copy contents from the
             * bottom of buffer
             */
            old_origin += (old_rows - new_rows) * old_row_size;
        } else {
            /*
             * Cursor is in no man's land, copy 1/2 screenful
             * from the top and bottom of cursor position
             */
            old_origin += (vc->vc_y - new_rows/2) * old_row_size;
        }
    }

    end = old_origin + old_row_size * min(old_rows, new_rows);

    update_attr(vc);

    while (old_origin < end) {
        scr_memcpyw((unsigned short *) new_origin,
                (unsigned short *) old_origin, rlth);
        if (rrem)
            scr_memsetw((void *)(new_origin + rlth),
                    vc->vc_video_erase_char, rrem);
        old_origin += old_row_size;
        new_origin += new_row_size;
    }
    if (new_scr_end > new_origin)
        scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
                new_scr_end - new_origin);
    kfree(vc->vc_screenbuf);
    vc->vc_screenbuf = newscreen;
    vc->vc_screenbuf_size = new_screen_size;
    set_origin(vc);

    /* do part of a reset_terminal() */
    vc->vc_top = 0;
    vc->vc_bottom = vc->vc_rows;
    gotoxy(vc, vc->vc_x, vc->vc_y);
    save_cur(vc);

    if (tty) {
        /* Rewrite the requested winsize data with the actual
           resulting sizes */
        struct winsize ws;
        memset(&ws, 0, sizeof(ws));
        ws.ws_row = vc->vc_rows;
        ws.ws_col = vc->vc_cols;
        ws.ws_ypixel = vc->vc_scan_lines;
        tty_do_resize(tty, &ws);
    }

    if (CON_IS_VISIBLE(vc))
        update_screen(vc);
    vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
    return err;
}

int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
{
    return vc_do_resize(vc->port.tty, vc, cols, rows);
}

static int vt_resize(struct tty_struct *tty, struct winsize *ws)
{
    struct vc_data *vc = tty->driver_data;
    int ret;

    console_lock();
    ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
    console_unlock();
    return ret;
}

void vc_deallocate(unsigned int currcons)
{
    WARN_CONSOLE_UNLOCKED();

    if (vc_cons_allocated(currcons)) {
        struct vc_data *vc = vc_cons[currcons].d;
        struct vt_notifier_param param = { .vc = vc };

        atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
        vcs_remove_sysfs(currcons);
        vc->vc_sw->con_deinit(vc);
        put_pid(vc->vt_pid);
        module_put(vc->vc_sw->owner);
        kfree(vc->vc_screenbuf);
        if (currcons >= MIN_NR_CONSOLES)
            kfree(vc);
        vc_cons[currcons].d = NULL;
    }
}

/*
 *  VT102 emulator
 */

#define set_kbd(vc, x)  vt_set_kbd_mode_bit((vc)->vc_num, (x))
#define clr_kbd(vc, x)  vt_clr_kbd_mode_bit((vc)->vc_num, (x))
#define is_kbd(vc, x)   vt_get_kbd_mode_bit((vc)->vc_num, (x))

#define decarm      VC_REPEAT
#define decckm      VC_CKMODE
#define kbdapplic   VC_APPLIC
#define lnm     VC_CRLF

/*
 * this is what the terminal answers to a ESC-Z or csi0c query.
 */
#define VT100ID "\033[?1;2c"
#define VT102ID "\033[?6c"

unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
                       8,12,10,14, 9,13,11,15 };

/* the default colour table, for VGA+ colour systems */
int default_red[] = {0x00,0xaa,0x00,0xaa,0x00,0xaa,0x00,0xaa,
    0x55,0xff,0x55,0xff,0x55,0xff,0x55,0xff};
int default_grn[] = {0x00,0x00,0xaa,0x55,0x00,0x00,0xaa,0xaa,
    0x55,0x55,0xff,0xff,0x55,0x55,0xff,0xff};
int default_blu[] = {0x00,0x00,0x00,0x00,0xaa,0xaa,0xaa,0xaa,
    0x55,0x55,0x55,0x55,0xff,0xff,0xff,0xff};

module_param_array(default_red, int, NULL, S_IRUGO | S_IWUSR);
module_param_array(default_grn, int, NULL, S_IRUGO | S_IWUSR);
module_param_array(default_blu, int, NULL, S_IRUGO | S_IWUSR);

/*
 * gotoxy() must verify all boundaries, because the arguments
 * might also be negative. If the given position is out of
 * bounds, the cursor is placed at the nearest margin.
 */
static void gotoxy(struct vc_data *vc, int new_x, int new_y)
{
    int min_y, max_y;

    if (new_x < 0)
        vc->vc_x = 0;
    else {
        if (new_x >= vc->vc_cols)
            vc->vc_x = vc->vc_cols - 1;
        else
            vc->vc_x = new_x;
    }

    if (vc->vc_decom) {
        min_y = vc->vc_top;
        max_y = vc->vc_bottom;
    } else {
        min_y = 0;
        max_y = vc->vc_rows;
    }
    if (new_y < min_y)
        vc->vc_y = min_y;
    else if (new_y >= max_y)
        vc->vc_y = max_y - 1;
    else
        vc->vc_y = new_y;
    vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
    vc->vc_need_wrap = 0;
}

/* for absolute user moves, when decom is set */
static void gotoxay(struct vc_data *vc, int new_x, int new_y)
{
    gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
}

void scrollback(struct vc_data *vc, int lines)
{
    if (!lines)
        lines = vc->vc_rows / 2;
    scrolldelta(-lines);
}

void scrollfront(struct vc_data *vc, int lines)
{
    if (!lines)
        lines = vc->vc_rows / 2;
    scrolldelta(lines);
}

static void lf(struct vc_data *vc)
{
        /* don't scroll if above bottom of scrolling region, or
     * if below scrolling region
     */
        if (vc->vc_y + 1 == vc->vc_bottom)
        scrup(vc, vc->vc_top, vc->vc_bottom, 1);
    else if (vc->vc_y < vc->vc_rows - 1) {
            vc->vc_y++;
        vc->vc_pos += vc->vc_size_row;
    }
    vc->vc_need_wrap = 0;
    notify_write(vc, '\n');
}

static void ri(struct vc_data *vc)
{
        /* don't scroll if below top of scrolling region, or
     * if above scrolling region
     */
    if (vc->vc_y == vc->vc_top)
        scrdown(vc, vc->vc_top, vc->vc_bottom, 1);
    else if (vc->vc_y > 0) {
        vc->vc_y--;
        vc->vc_pos -= vc->vc_size_row;
    }
    vc->vc_need_wrap = 0;
}

static inline void cr(struct vc_data *vc)
{
    vc->vc_pos -= vc->vc_x << 1;
    vc->vc_need_wrap = vc->vc_x = 0;
    notify_write(vc, '\r');
}

static inline void bs(struct vc_data *vc)
{
    if (vc->vc_x) {
        vc->vc_pos -= 2;
        vc->vc_x--;
        vc->vc_need_wrap = 0;
        notify_write(vc, '\b');
    }
}

static inline void del(struct vc_data *vc)
{
    /* ignored */
}

static void csi_J(struct vc_data *vc, int vpar)
{
    unsigned int count;
    unsigned short * start;

    switch (vpar) {
        case 0: /* erase from cursor to end of display */
            count = (vc->vc_scr_end - vc->vc_pos) >> 1;
            start = (unsigned short *)vc->vc_pos;
            break;
        case 1: /* erase from start to cursor */
            count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
            start = (unsigned short *)vc->vc_origin;
            break;
        case 3: /* erase scroll-back buffer (and whole display) */
            scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
                    vc->vc_screenbuf_size >> 1);
            set_origin(vc);
            /* fall through */
        case 2: /* erase whole display */
            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 (DO_UPDATE(vc))
        do_update_region(vc, (unsigned long) start, count);
    vc->vc_need_wrap = 0;
}

static void csi_K(struct vc_data *vc, int vpar)
{
    unsigned int count;
    unsigned short * start;

    switch (vpar) {
        case 0: /* erase from cursor to end of line */
            count = vc->vc_cols - vc->vc_x;
            start = (unsigned short *)vc->vc_pos;
            break;
        case 1: /* erase from start of line to cursor */
            start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
            count = vc->vc_x + 1;
            break;
        case 2: /* erase whole line */
            start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
            count = vc->vc_cols;
            break;
        default:
            return;
    }
    scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
    vc->vc_need_wrap = 0;
    if (DO_UPDATE(vc))
        do_update_region(vc, (unsigned long) start, count);
}

static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
{                     /* not vt100? */
    int count;

    if (!vpar)
        vpar++;
    count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;

    scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
    if (DO_UPDATE(vc))
        vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
    vc->vc_need_wrap = 0;
}

static void default_attr(struct vc_data *vc)
{
    vc->vc_intensity = 1;
    vc->vc_italic = 0;
    vc->vc_underline = 0;
    vc->vc_reverse = 0;
    vc->vc_blink = 0;
    vc->vc_color = vc->vc_def_color;
}

/* console_lock is held */
static void csi_m(struct vc_data *vc)
{
    int i;

    for (i = 0; i <= vc->vc_npar; i++)
        switch (vc->vc_par[i]) {
            case 0: /* all attributes off */
                default_attr(vc);
                break;
            case 1:
                vc->vc_intensity = 2;
                break;
            case 2:
                vc->vc_intensity = 0;
                break;
            case 3:
                vc->vc_italic = 1;
                break;
            case 4:
                vc->vc_underline = 1;
                break;
            case 5:
                vc->vc_blink = 1;
                break;
            case 7:
                vc->vc_reverse = 1;
                break;
            case 10: /* ANSI X3.64-1979 (SCO-ish?)
                  * Select primary font, don't display
                  * control chars if defined, don't set
                  * bit 8 on output.
                  */
                vc->vc_translate = set_translate(vc->vc_charset == 0
                        ? vc->vc_G0_charset
                        : vc->vc_G1_charset, vc);
                vc->vc_disp_ctrl = 0;
                vc->vc_toggle_meta = 0;
                break;
            case 11: /* ANSI X3.64-1979 (SCO-ish?)
                  * Select first alternate font, lets
                  * chars < 32 be displayed as ROM chars.
                  */
                vc->vc_translate = set_translate(IBMPC_MAP, vc);
                vc->vc_disp_ctrl = 1;
                vc->vc_toggle_meta = 0;
                break;
            case 12: /* ANSI X3.64-1979 (SCO-ish?)
                  * Select second alternate font, toggle
                  * high bit before displaying as ROM char.
                  */
                vc->vc_translate = set_translate(IBMPC_MAP, vc);
                vc->vc_disp_ctrl = 1;
                vc->vc_toggle_meta = 1;
                break;
            case 21:
            case 22:
                vc->vc_intensity = 1;
                break;
            case 23:
                vc->vc_italic = 0;
                break;
            case 24:
                vc->vc_underline = 0;
                break;
            case 25:
                vc->vc_blink = 0;
                break;
            case 27:
                vc->vc_reverse = 0;
                break;
            case 38: /* ANSI X3.64-1979 (SCO-ish?)
                  * Enables underscore, white foreground
                  * with white underscore (Linux - use
                  * default foreground).
                  */
                vc->vc_color = (vc->vc_def_color & 0x0f) | (vc->vc_color & 0xf0);
                vc->vc_underline = 1;
                break;
            case 39: /* ANSI X3.64-1979 (SCO-ish?)
                  * Disable underline option.
                  * Reset colour to default? It did this
                  * before...
                  */
                vc->vc_color = (vc->vc_def_color & 0x0f) | (vc->vc_color & 0xf0);
                vc->vc_underline = 0;
                break;
            case 49:
                vc->vc_color = (vc->vc_def_color & 0xf0) | (vc->vc_color & 0x0f);
                break;
            default:
                if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
                    vc->vc_color = color_table[vc->vc_par[i] - 30]
                        | (vc->vc_color & 0xf0);
                else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
                    vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
                        | (vc->vc_color & 0x0f);
                break;
        }
    update_attr(vc);
}

static void respond_string(const char *p, struct tty_struct *tty)
{
    while (*p) {
        tty_insert_flip_char(tty, *p, 0);
        p++;
    }
    tty_schedule_flip(tty);
}

static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
{
    char buf[40];

    sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
    respond_string(buf, tty);
}

static inline void status_report(struct tty_struct *tty)
{
    respond_string("\033[0n", tty); /* Terminal ok */
}

static inline void respond_ID(struct tty_struct * tty)
{
    respond_string(VT102ID, tty);
}

void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
{
    char buf[8];

    sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
        (char)('!' + mry));
    respond_string(buf, tty);
}

/* invoked via ioctl(TIOCLINUX) and through set_selection */
int mouse_reporting(void)
{
    return vc_cons[fg_console].d->vc_report_mouse;
}

/* console_lock is held */
static void set_mode(struct vc_data *vc, int on_off)
{
    int i;

    for (i = 0; i <= vc->vc_npar; i++)
        if (vc->vc_ques) {
            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 */
                vc->vc_deccolm = on_off;
#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 */
#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, 0);
                    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;
            }
        }
}

/* console_lock is held */
static void setterm_command(struct vc_data *vc)
{
    switch(vc->vc_par[0]) {
        case 1: /* set color for underline mode */
            if (vc->vc_can_do_color &&
                    vc->vc_par[1] < 16) {
                vc->vc_ulcolor = color_table[vc->vc_par[1]];
                if (vc->vc_underline)
                    update_attr(vc);
            }
            break;
        case 2: /* set color for half intensity mode */
            if (vc->vc_can_do_color &&
                    vc->vc_par[1] < 16) {
                vc->vc_halfcolor = color_table[vc->vc_par[1]];
                if (vc->vc_intensity == 0)
                    update_attr(vc);
            }
            break;
        case 8: /* store colors as defaults */
            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 */
            blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
            poke_blanked_console();
            break;
        case 10: /* set bell frequency in Hz */
            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 */
            if (vc->vc_npar >= 1)
                vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
                    vc->vc_par[1] * HZ / 1000 : 0;
            else
                vc->vc_bell_duration = DEFAULT_BELL_DURATION;
            break;
        case 12: /* bring specified console to the 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 */
            poke_blanked_console();
            break;
        case 14: /* set vesa powerdown interval */
            vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
            break;
        case 15: /* activate the previous console */
            set_console(last_console);
            break;
    }
}

/* console_lock is held */
static void csi_at(struct vc_data *vc, unsigned int nr)
{
    if (nr > vc->vc_cols - vc->vc_x)
        nr = vc->vc_cols - vc->vc_x;
    else if (!nr)
        nr = 1;
    insert_char(vc, nr);
}

/* console_lock is held */
static void csi_L(struct vc_data *vc, unsigned int nr)
{
    if (nr > vc->vc_rows - vc->vc_y)
        nr = vc->vc_rows - vc->vc_y;
    else if (!nr)
        nr = 1;
    scrdown(vc, vc->vc_y, vc->vc_bottom, nr);
    vc->vc_need_wrap = 0;
}

/* console_lock is held */
static void csi_P(struct vc_data *vc, unsigned int nr)
{
    if (nr > vc->vc_cols - vc->vc_x)
        nr = vc->vc_cols - vc->vc_x;
    else if (!nr)
        nr = 1;
    delete_char(vc, nr);
}

/* console_lock is held */
static void csi_M(struct vc_data *vc, unsigned int nr)
{
    if (nr > vc->vc_rows - vc->vc_y)
        nr = vc->vc_rows - vc->vc_y;
    else if (!nr)
        nr=1;
    scrup(vc, vc->vc_y, vc->vc_bottom, nr);
    vc->vc_need_wrap = 0;
}

/* console_lock is held (except via vc_init->reset_terminal */
static void save_cur(struct vc_data *vc)
{
    vc->vc_saved_x      = vc->vc_x;
    vc->vc_saved_y      = vc->vc_y;
    vc->vc_s_intensity  = vc->vc_intensity;
    vc->vc_s_italic         = vc->vc_italic;
    vc->vc_s_underline  = vc->vc_underline;
    vc->vc_s_blink      = vc->vc_blink;
    vc->vc_s_reverse    = vc->vc_reverse;
    vc->vc_s_charset    = vc->vc_charset;
    vc->vc_s_color      = vc->vc_color;
    vc->vc_saved_G0     = vc->vc_G0_charset;
    vc->vc_saved_G1     = vc->vc_G1_charset;
}

/* console_lock is held */
static void restore_cur(struct vc_data *vc)
{
    gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
    vc->vc_intensity    = vc->vc_s_intensity;
    vc->vc_italic       = vc->vc_s_italic;
    vc->vc_underline    = vc->vc_s_underline;
    vc->vc_blink        = vc->vc_s_blink;
    vc->vc_reverse      = vc->vc_s_reverse;
    vc->vc_charset      = vc->vc_s_charset;
    vc->vc_color        = vc->vc_s_color;
    vc->vc_G0_charset   = vc->vc_saved_G0;
    vc->vc_G1_charset   = vc->vc_saved_G1;
    vc->vc_translate    = set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
    update_attr(vc);
    vc->vc_need_wrap = 0;
}

enum { ESnormal, ESesc, ESsquare, ESgetpars, ESgotpars, ESfunckey,
    EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
    ESpalette };

/* console_lock is held (except via vc_init()) */
static void reset_terminal(struct vc_data *vc, int do_clear)
{
    vc->vc_top      = 0;
    vc->vc_bottom       = vc->vc_rows;
    vc->vc_state        = ESnormal;
    vc->vc_ques     = 0;
    vc->vc_translate    = set_translate(LAT1_MAP, vc);
    vc->vc_G0_charset   = LAT1_MAP;
    vc->vc_G1_charset   = GRAF_MAP;
    vc->vc_charset      = 0;
    vc->vc_need_wrap    = 0;
    vc->vc_report_mouse = 0;
    vc->vc_utf              = default_utf8;
    vc->vc_utf_count    = 0;

    vc->vc_disp_ctrl    = 0;
    vc->vc_toggle_meta  = 0;

    vc->vc_decscnm      = 0;
    vc->vc_decom        = 0;
    vc->vc_decawm       = 1;
    vc->vc_deccm        = global_cursor_default;
    vc->vc_decim        = 0;

    vt_reset_keyboard(vc->vc_num);

    vc->vc_cursor_type = cur_default;
    vc->vc_complement_mask = vc->vc_s_complement_mask;

    default_attr(vc);
    update_attr(vc);

    vc->vc_tab_stop[0]  = 0x01010100;
    vc->vc_tab_stop[1]  =
    vc->vc_tab_stop[2]  =
    vc->vc_tab_stop[3]  =
    vc->vc_tab_stop[4]  =
    vc->vc_tab_stop[5]  =
    vc->vc_tab_stop[6]  =
    vc->vc_tab_stop[7]  = 0x01010101;

    vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
    vc->vc_bell_duration = DEFAULT_BELL_DURATION;

    gotoxy(vc, 0, 0);
    save_cur(vc);
    if (do_clear)
        csi_J(vc, 2);
}

/* console_lock is held */
static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
{
    /*
     *  Control characters can be used in the _middle_
     *  of an escape sequence.
     */
    switch (c) {
    case 0:
        return;
    case 7:
        if (vc->vc_bell_duration)
            kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
        return;
    case 8:
        bs(vc);
        return;
    case 9:
        vc->vc_pos -= (vc->vc_x << 1);
        while (vc->vc_x < vc->vc_cols - 1) {
            vc->vc_x++;
            if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
                break;
        }
        vc->vc_pos += (vc->vc_x << 1);
        notify_write(vc, '\t');
        return;
    case 10: case 11: case 12:
        lf(vc);
        if (!is_kbd(vc, lnm))
            return;
    case 13:
        cr(vc);
        return;
    case 14:
        vc->vc_charset = 1;
        vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
        vc->vc_disp_ctrl = 1;
        return;
    case 15:
        vc->vc_charset = 0;
        vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
        vc->vc_disp_ctrl = 0;
        return;
    case 24: case 26:
        vc->vc_state = ESnormal;
        return;
    case 27:
        vc->vc_state = ESesc;
        return;
    case 127:
        del(vc);
        return;
    case 128+27:
        vc->vc_state = ESsquare;
        return;
    }
    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 = ESpercent;
            return;
        case 'E':
            cr(vc);
            lf(vc);
            return;
        case 'M':
            ri(vc);
            return;
        case 'D':
            lf(vc);
            return;
        case 'H':
            vc->vc_tab_stop[vc->vc_x >> 5] |= (1 << (vc->vc_x & 31));
            return;
        case 'Z':
            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;
        }
        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;
            vc->vc_state = ESpalette;
            return;
        } else if (c=='R') {   /* reset palette */
            reset_palette(vc);
            vc->vc_state = ESnormal;
        } else
            vc->vc_state = ESnormal;
        return;
    case ESpalette:
        if (isxdigit(c)) {
            vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
            if (vc->vc_npar == 7) {
                int i = vc->vc_par[0] * 3, j = 1;
                vc->vc_palette[i] = 16 * vc->vc_par[j++];
                vc->vc_palette[i++] += vc->vc_par[j++];
                vc->vc_palette[i] = 16 * vc->vc_par[j++];
                vc->vc_palette[i++] += vc->vc_par[j++];
                vc->vc_palette[i] = 16 * vc->vc_par[j++];
                vc->vc_palette[i] += vc->vc_par[j];
                set_palette(vc);
                vc->vc_state = ESnormal;
            }
        } 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;
        vc->vc_state = ESgetpars;
        if (c == '[') { /* Function key */
            vc->vc_state=ESfunckey;
            return;
        }
        vc->vc_ques = (c == '?');
        if (vc->vc_ques)
            return;
    case ESgetpars:
        if (c == ';' && vc->vc_npar < NPAR - 1) {
            vc->vc_npar++;
            return;
        } else if (c>='0' && c<='9') {
            vc->vc_par[vc->vc_npar] *= 10;
            vc->vc_par[vc->vc_npar] += c - '0';
            return;
        } else
            vc->vc_state = ESgotpars;
    case ESgotpars:
        vc->vc_state = ESnormal;
        switch(c) {
        case 'h':
            set_mode(vc, 1);
            return;
        case 'l':
            set_mode(vc, 0);
            return;
        case 'c':
            if (vc->vc_ques) {
                if (vc->vc_par[0])
                    vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
                else
                    vc->vc_cursor_type = cur_default;
                return;
            }
            break;
        case 'm':
            if (vc->vc_ques) {
                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_ques) {
                if (vc->vc_par[0] == 5)
                    status_report(tty);
                else if (vc->vc_par[0] == 6)
                    cursor_report(vc, tty);
            }
            return;
        }
        if (vc->vc_ques) {
            vc->vc_ques = 0;
            return;
        }
        switch(c) {
        case 'G': case '`':
            if (vc->vc_par[0])
                vc->vc_par[0]--;
            gotoxy(vc, vc->vc_par[0], vc->vc_y);
            return;
        case 'A':
            if (!vc->vc_par[0])
                vc->vc_par[0]++;
            gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
            return;
        case 'B': case 'e':
            if (!vc->vc_par[0])
                vc->vc_par[0]++;
            gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
            return;
        case 'C': case 'a':
            if (!vc->vc_par[0])
                vc->vc_par[0]++;
            gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
            return;
        case 'D':
            if (!vc->vc_par[0])
                vc->vc_par[0]++;
            gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
            return;
        case 'E':
            if (!vc->vc_par[0])
                vc->vc_par[0]++;
            gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
            return;
        case 'F':
            if (!vc->vc_par[0])
                vc->vc_par[0]++;
            gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
            return;
        case 'd':
            if (vc->vc_par[0])
                vc->vc_par[0]--;
            gotoxay(vc, vc->vc_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->vc_tab_stop[vc->vc_x >> 5] &= ~(1 << (vc->vc_x & 31));
            else if (vc->vc_par[0] == 3) {
                vc->vc_tab_stop[0] =
                    vc->vc_tab_stop[1] =
                    vc->vc_tab_stop[2] =
                    vc->vc_tab_stop[3] =
                    vc->vc_tab_stop[4] =
                    vc->vc_tab_stop[5] =
                    vc->vc_tab_stop[6] =
                    vc->vc_tab_stop[7] = 0;
            }
            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]);
            return;
        case '@':
            csi_at(vc, vc->vc_par[0]);
            return;
        case ']': /* setterm functions */
            setterm_command(vc);
            return;
        }
        return;
    case ESpercent:
        vc->vc_state = ESnormal;
        switch (c) {
        case '@':  /* defined in ISO 2022 */
            vc->vc_utf = 0;
            return;
        case 'G':  /* prelim official escape code */
        case '8':  /* retained for compatibility */
            vc->vc_utf = 1;
            return;
        }
        return;
    case ESfunckey:
        vc->vc_state = ESnormal;
        return;
    case EShash:
        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);
            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:
        if (c == '0')
            vc->vc_G0_charset = GRAF_MAP;
        else if (c == 'B')
            vc->vc_G0_charset = LAT1_MAP;
        else if (c == 'U')
            vc->vc_G0_charset = IBMPC_MAP;
        else if (c == 'K')
            vc->vc_G0_charset = USER_MAP;
        if (vc->vc_charset == 0)
            vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
        vc->vc_state = ESnormal;
        return;
    case ESsetG1:
        if (c == '0')
            vc->vc_G1_charset = GRAF_MAP;
        else if (c == 'B')
            vc->vc_G1_charset = LAT1_MAP;
        else if (c == 'U')
            vc->vc_G1_charset = IBMPC_MAP;
        else if (c == 'K')
            vc->vc_G1_charset = USER_MAP;
        if (vc->vc_charset == 1)
            vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
        vc->vc_state = ESnormal;
        return;
    default:
        vc->vc_state = ESnormal;
    }
}

/* is_double_width() is based on the wcwidth() implementation by
 * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
 * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
 */
struct interval {
    uint32_t first;
    uint32_t last;
};

static int bisearch(uint32_t ucs, const struct interval *table, int max)
{
    int min = 0;
    int mid;

    if (ucs < table[0].first || ucs > table[max].last)
        return 0;
    while (max >= min) {
        mid = (min + max) / 2;
        if (ucs > table[mid].last)
            min = mid + 1;
        else if (ucs < table[mid].first)
            max = mid - 1;
        else
            return 1;
    }
    return 0;
}

static int is_double_width(uint32_t ucs)
{
    static const struct interval double_width[] = {
        { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
        { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
        { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
        { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
    };
    return bisearch(ucs, double_width, ARRAY_SIZE(double_width) - 1);
}

/* acquires console_lock */
static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
#ifdef VT_BUF_VRAM_ONLY
#define FLUSH do { } while(0);
#else
#define FLUSH if (draw_x >= 0) { \
    vc->vc_sw->con_putcs(vc, (u16 *)draw_from, (u16 *)draw_to - (u16 *)draw_from, vc->vc_y, draw_x); \
    draw_x = -1; \
    }
#endif

    int c, tc, ok, n = 0, draw_x = -1;
    unsigned int currcons;
    unsigned long draw_from = 0, draw_to = 0;
    struct vc_data *vc;
    unsigned char vc_attr;
    struct vt_notifier_param param;
    uint8_t rescan;
    uint8_t inverse;
    uint8_t width;
    u16 himask, charmask;

    if (in_interrupt())
        return count;

    might_sleep();

    console_lock();
    vc = tty->driver_data;
    if (vc == NULL) {
        printk(KERN_ERR "vt: argh, driver_data is NULL !\n");
        console_unlock();
        return 0;
    }

    currcons = vc->vc_num;
    if (!vc_cons_allocated(currcons)) {
        /* could this happen? */
        pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
        console_unlock();
        return 0;
    }

    himask = vc->vc_hi_font_mask;
    charmask = himask ? 0x1ff : 0xff;

    /* undraw cursor first */
    if (IS_FG(vc))
        hide_cursor(vc);

    param.vc = vc;

    while (!tty->stopped && count) {
        int orig = *buf;
        c = orig;
        buf++;
        n++;
        count--;
        rescan = 0;
        inverse = 0;
        width = 1;

        /* Do no translation at all in control states */
        if (vc->vc_state != ESnormal) {
            tc = c;
        } else if (vc->vc_utf && !vc->vc_disp_ctrl) {
            /* Combine UTF-8 into Unicode in vc_utf_char.
             * vc_utf_count is the number of continuation bytes still
             * expected to arrive.
             * vc_npar is the number of continuation bytes arrived so
             * far
             */
rescan_last_byte:
            if ((c & 0xc0) == 0x80) {
            /* Continuation byte received */
            static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
            if (vc->vc_utf_count) {
                vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
                vc->vc_npar++;
                if (--vc->vc_utf_count) {
                /* Still need some bytes */
                continue;
                }
                /* Got a whole character */
                c = vc->vc_utf_char;
                /* Reject overlong sequences */
                if (c <= utf8_length_changes[vc->vc_npar - 1] ||
                    c > utf8_length_changes[vc->vc_npar])
                c = 0xfffd;
            } else {
                /* Unexpected continuation byte */
                vc->vc_utf_count = 0;
                c = 0xfffd;
            }
            } else {
            /* Single ASCII byte or first byte of a sequence received */
            if (vc->vc_utf_count) {
                /* Continuation byte expected */
                rescan = 1;
                vc->vc_utf_count = 0;
                c = 0xfffd;
            } else if (c > 0x7f) {
                /* First byte of a multibyte sequence received */
                vc->vc_npar = 0;
                if ((c & 0xe0) == 0xc0) {
                vc->vc_utf_count = 1;
                vc->vc_utf_char = (c & 0x1f);
                } else if ((c & 0xf0) == 0xe0) {
                vc->vc_utf_count = 2;
                vc->vc_utf_char = (c & 0x0f);
                } 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 */
                c = 0xfffd;
                }
                if (vc->vc_utf_count) {
                /* Still need some bytes */
                continue;
                }
            }
            /* Nothing to do if an ASCII byte was received */
            }
            /* End of UTF-8 decoding. */
            /* c is the received character, or U+FFFD for invalid sequences. */
            /* Replace invalid Unicode code points with U+FFFD too */
            if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
            c = 0xfffd;
            tc = c;
        } else {    /* no utf or alternate charset mode */
            tc = vc_translate(vc, c);
        }

        param.c = tc;
        if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
                    &param) == NOTIFY_STOP)
            continue;

                /* If the original code was a control character we
                 * only allow a glyph to be displayed if the code is
                 * not normally used (such as for cursor movement) or
                 * if the disp_ctrl mode has been explicitly enabled.
                 * Certain characters (as given by the CTRL_ALWAYS
                 * bitmap) are always displayed as control characters,
                 * as the console would be pretty useless without
                 * them; to display an arbitrary font position use the
                 * direct-to-font zone in UTF-8 mode.
                 */
                ok = tc && (c >= 32 ||
                !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
                  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
            && (c != 127 || vc->vc_disp_ctrl)
            && (c != 128+27);

        if (vc->vc_state == ESnormal && ok) {
            if (vc->vc_utf && !vc->vc_disp_ctrl) {
                if (is_double_width(c))
                    width = 2;
            }
            /* Now try to find out how to display it */
            tc = conv_uni_to_pc(vc, tc);
            if (tc & ~charmask) {
                if (tc == -1 || tc == -2) {
                    continue; /* nothing to display */
                }
                /* Glyph not found */
                if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
                    /* In legacy mode use the glyph we get by a 1:1 mapping.
                       This would make absolutely no sense with Unicode in mind,
                       but do this for ASCII characters since a font may lack
                       Unicode mapping info and we don't want to end up with
                       having question marks only. */
                    tc = c;
                } else {
                    /* Display U+FFFD. If it's not found, display an inverse question mark. */
                    tc = conv_uni_to_pc(vc, 0xfffd);
                    if (tc < 0) {
                    inverse = 1;
                    tc = conv_uni_to_pc(vc, '?');
                    if (tc < 0) tc = '?';
                    }
                }
            }

            if (!inverse) {
                vc_attr = vc->vc_attr;
            } else {
                /* invert vc_attr */
                if (!vc->vc_can_do_color) {
                    vc_attr = (vc->vc_attr) ^ 0x08;
                } else if (vc->vc_hi_font_mask == 0x100) {
                    vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
                } else {
                    vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
                }
                FLUSH
            }

            while (1) {
                if (vc->vc_need_wrap || vc->vc_decim)
                    FLUSH
                if (vc->vc_need_wrap) {
                    cr(vc);
                    lf(vc);
                }
                if (vc->vc_decim)
                    insert_char(vc, 1);
                scr_writew(himask ?
                         ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
                         (vc_attr << 8) + tc,
                       (u16 *) vc->vc_pos);
                if (DO_UPDATE(vc) && draw_x < 0) {
                    draw_x = vc->vc_x;
                    draw_from = vc->vc_pos;
                }
                if (vc->vc_x == vc->vc_cols - 1) {
                    vc->vc_need_wrap = vc->vc_decawm;
                    draw_to = vc->vc_pos + 2;
                } else {
                    vc->vc_x++;
                    draw_to = (vc->vc_pos += 2);
                }

                if (!--width) break;

                tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
                if (tc < 0) tc = ' ';
            }
            notify_write(vc, c);

            if (inverse) {
                FLUSH
            }

            if (rescan) {
                rescan = 0;
                inverse = 0;
                width = 1;
                c = orig;
                goto rescan_last_byte;
            }
            continue;
        }
        FLUSH
        do_con_trol(tty, vc, orig);
    }
    FLUSH
    console_conditional_schedule();
    console_unlock();
    notify_update(vc);
    return n;
#undef FLUSH
}

/*
 * This is the console switching callback.
 *
 * Doing console switching in a process context allows
 * us to do the switches asynchronously (needed when we want
 * to switch due to a keyboard interrupt).  Synchronization
 * with other console code and prevention of re-entrancy is
 * ensured with console_lock.
 */
static void console_callback(struct work_struct *ignored)
{
    console_lock();

    if (want_console >= 0) {
        if (want_console != fg_console &&
            vc_cons_allocated(want_console)) {
            hide_cursor(vc_cons[fg_console].d);
            change_console(vc_cons[want_console].d);
            /* we only changed when the console had already
               been allocated - a new console is not created
               in an interrupt routine */
        }
        want_console = -1;
    }
    if (do_poke_blanked_console) { /* do not unblank for a LED change */
        do_poke_blanked_console = 0;
        poke_blanked_console();
    }
    if (scrollback_delta) {
        struct vc_data *vc = vc_cons[fg_console].d;
        clear_selection();
        if (vc->vc_mode == KD_TEXT)
            vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
        scrollback_delta = 0;
    }
    if (blank_timer_expired) {
        do_blank_screen(0);
        blank_timer_expired = 0;
    }
    notify_update(vc_cons[fg_console].d);

    console_unlock();
}

int set_console(int nr)
{
    struct vc_data *vc = vc_cons[fg_console].d;

    if (!vc_cons_allocated(nr) || vt_dont_switch ||
        (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {

        /*
         * Console switch will fail in console_callback() or
         * change_console() so there is no point scheduling
         * the callback
         *
         * Existing set_console() users don't check the return
         * value so this shouldn't break anything
         */
        return -EINVAL;
    }

    want_console = nr;
    schedule_console_callback();

    return 0;
}

struct tty_driver *console_driver;

#ifdef CONFIG_VT_CONSOLE

int vt_kmsg_redirect(int new)
{
    static int kmsg_con;

    if (new != -1)
        return xchg(&kmsg_con, new);
    else
        return kmsg_con;
}

/*
 *  Console on virtual terminal
 *
 * The console must be locked when we get here.
 */

static void vt_console_print(struct console *co, const char *b, unsigned count)
{
    struct vc_data *vc = vc_cons[fg_console].d;
    unsigned char c;
    static DEFINE_SPINLOCK(printing_lock);
    const ushort *start;
    ushort cnt = 0;
    ushort myx;
    int kmsg_console;

    /* console busy or not yet initialized */
    if (!printable)
        return;
    if (!spin_trylock(&printing_lock))
        return;

    kmsg_console = vt_get_kmsg_redirect();
    if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
        vc = vc_cons[kmsg_console - 1].d;

    /* read `x' only after setting currcons properly (otherwise
       the `x' macro will read the x of the foreground console). */
    myx = vc->vc_x;

    if (!vc_cons_allocated(fg_console)) {
        /* impossible */
        /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
        goto quit;
    }

    if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
        goto quit;

    /* undraw cursor first */
    if (IS_FG(vc))
        hide_cursor(vc);

    start = (ushort *)vc->vc_pos;

    /* Contrived structure to try to emulate original need_wrap behaviour
     * Problems caused when we have need_wrap set on '\n' character */
    while (count--) {
        c = *b++;
        if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
            if (cnt > 0) {
                if (CON_IS_VISIBLE(vc))
                    vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
                vc->vc_x += cnt;
                if (vc->vc_need_wrap)
                    vc->vc_x--;
                cnt = 0;
            }
            if (c == 8) {       /* backspace */
                bs(vc);
                start = (ushort *)vc->vc_pos;
                myx = vc->vc_x;
                continue;
            }
            if (c != 13)
                lf(vc);
            cr(vc);
            start = (ushort *)vc->vc_pos;
            myx = vc->vc_x;
            if (c == 10 || c == 13)
                continue;
        }
        scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
        notify_write(vc, c);
        cnt++;
        if (myx == vc->vc_cols - 1) {
            vc->vc_need_wrap = 1;
            continue;
        }
        vc->vc_pos += 2;
        myx++;
    }
    if (cnt > 0) {
        if (CON_IS_VISIBLE(vc))
            vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
        vc->vc_x += cnt;
        if (vc->vc_x == vc->vc_cols) {
            vc->vc_x--;
            vc->vc_need_wrap = 1;
        }
    }
    set_cursor(vc);
    notify_update(vc);

quit:
    spin_unlock(&printing_lock);
}

static struct tty_driver *vt_console_device(struct console *c, int *index)
{
    *index = c->index ? c->index-1 : fg_console;
    return console_driver;
}

static struct console vt_console_driver = {
    .name       = "tty",
    .write      = vt_console_print,
    .device     = vt_console_device,
    .unblank    = unblank_screen,
    .flags      = CON_PRINTBUFFER,
    .index      = -1,
};
#endif

/*
 *  Handling of Linux-specific VC ioctls
 */

/*
 * Generally a bit racy with respect to console_lock();.
 *
 * There are some functions which don't need it.
 *
 * There are some functions which can sleep for arbitrary periods
 * (paste_selection) but we don't need the lock there anyway.
 *
 * set_selection has locking, and definitely needs it
 */

int tioclinux(struct tty_struct *tty, unsigned long arg)
{
    char type, data;
    char __user *p = (char __user *)arg;
    int lines;
    int ret;

    if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
        return -EPERM;
    if (get_user(type, p))
        return -EFAULT;
    ret = 0;

    switch (type)
    {
        case TIOCL_SETSEL:
            console_lock();
            ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
            console_unlock();
            break;
        case TIOCL_PASTESEL:
            ret = paste_selection(tty);
            break;
        case TIOCL_UNBLANKSCREEN:
            console_lock();
            unblank_screen();
            console_unlock();
            break;
        case TIOCL_SELLOADLUT:
            console_lock();
            ret = sel_loadlut(p);
            console_unlock();
            break;
        case TIOCL_GETSHIFTSTATE:

    /*
     * Make it possible to react to Shift+Mousebutton.
     * Note that 'shift_state' is an undocumented
     * kernel-internal variable; programs not closely
     * related to the kernel should not use this.
     */
            data = vt_get_shift_state();
            ret = __put_user(data, p);
            break;
        case TIOCL_GETMOUSEREPORTING:
            console_lock(); /* May be overkill */
            data = mouse_reporting();
            console_unlock();
            ret = __put_user(data, p);
            break;
        case TIOCL_SETVESABLANK:
            console_lock();
            ret = set_vesa_blanking(p);
            console_unlock();
            break;
        case TIOCL_GETKMSGREDIRECT:
            data = vt_get_kmsg_redirect();
            ret = __put_user(data, p);
            break;
        case TIOCL_SETKMSGREDIRECT:
            if (!capable(CAP_SYS_ADMIN)) {
                ret = -EPERM;
            } else {
                if (get_user(data, p+1))
                    ret = -EFAULT;
                else
                    vt_kmsg_redirect(data);
            }
            break;
        case TIOCL_GETFGCONSOLE:
            /* No locking needed as this is a transiently
               correct return anyway if the caller hasn't
               disabled switching */
            ret = fg_console;
            break;
        case TIOCL_SCROLLCONSOLE:
            if (get_user(lines, (s32 __user *)(p+4))) {
                ret = -EFAULT;
            } else {
                /* Need the console lock here. Note that lots
                   of other calls need fixing before the lock
                   is actually useful ! */
                console_lock();
                scrollfront(vc_cons[fg_console].d, lines);
                console_unlock();
                ret = 0;
            }
            break;
        case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
            console_lock();
            ignore_poke = 1;
            do_blank_screen(0);
            console_unlock();
            break;
        case TIOCL_BLANKEDSCREEN:
            ret = console_blanked;
            break;
        default:
            ret = -EINVAL;
            break;
    }
    return ret;
}

/*
 * /dev/ttyN handling
 */

static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
    int retval;

    retval = do_con_write(tty, buf, count);
    con_flush_chars(tty);

    return retval;
}

static int con_put_char(struct tty_struct *tty, unsigned char ch)
{
    if (in_interrupt())
        return 0;   /* n_r3964 calls put_char() from interrupt context */
    return do_con_write(tty, &ch, 1);
}

static int con_write_room(struct tty_struct *tty)
{
    if (tty->stopped)
        return 0;
    return 32768;       /* No limit, really; we're not buffering */
}

static int con_chars_in_buffer(struct tty_struct *tty)
{
    return 0;       /* we're not buffering */
}

/*
 * con_throttle and con_unthrottle are only used for
 * paste_selection(), which has to stuff in a large number of
 * characters...
 */
static void con_throttle(struct tty_struct *tty)
{
}

static void con_unthrottle(struct tty_struct *tty)
{
    struct vc_data *vc = tty->driver_data;

    wake_up_interruptible(&vc->paste_wait);
}

/*
 * Turn the Scroll-Lock LED on when the tty is stopped
 */
static void con_stop(struct tty_struct *tty)
{
    int console_num;
    if (!tty)
        return;
    console_num = tty->index;
    if (!vc_cons_allocated(console_num))
        return;
    vt_kbd_con_stop(console_num);
}

/*
 * Turn the Scroll-Lock LED off when the console is started
 */
static void con_start(struct tty_struct *tty)
{
    int console_num;
    if (!tty)
        return;
    console_num = tty->index;
    if (!vc_cons_allocated(console_num))
        return;
    vt_kbd_con_start(console_num);
}

static void con_flush_chars(struct tty_struct *tty)
{
    struct vc_data *vc;

    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);
    console_unlock();
}

/*
 * Allocate the console screen memory.
 */
static int con_install(struct tty_driver *driver, struct tty_struct *tty)
{
    unsigned int currcons = tty->index;
    struct vc_data *vc;
    int ret;

    console_lock();
    ret = vc_allocate(currcons);
    if (ret)
        goto unlock;

    vc = vc_cons[currcons].d;

    /* Still being freed */
    if (vc->port.tty) {
        ret = -ERESTARTSYS;
        goto unlock;
    }

    ret = tty_port_install(&vc->port, driver, tty);
    if (ret)
        goto unlock;

    tty->driver_data = vc;
    vc->port.tty = tty;

    if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
        tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
        tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
    }
    if (vc->vc_utf)
        tty->termios.c_iflag |= IUTF8;
    else
        tty->termios.c_iflag &= ~IUTF8;
unlock:
    console_unlock();
    return ret;
}

static int con_open(struct tty_struct *tty, struct file *filp)
{
    /* everything done in install */
    return 0;
}


static void con_close(struct tty_struct *tty, struct file *filp)
{
    /* Nothing to do - we defer to shutdown */
}

static void con_shutdown(struct tty_struct *tty)
{
    struct vc_data *vc = tty->driver_data;
    BUG_ON(vc == NULL);
    console_lock();
    vc->port.tty = NULL;
    console_unlock();
}

static int default_italic_color    = 2; // green (ASCII)
static int default_underline_color = 3; // cyan (ASCII)
module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);

static void vc_init(struct vc_data *vc, unsigned int rows,
            unsigned int cols, int do_clear)
{
    int j, k ;

    vc->vc_cols = cols;
    vc->vc_rows = rows;
    vc->vc_size_row = cols << 1;
    vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;

    set_origin(vc);
    vc->vc_pos = vc->vc_origin;
    reset_vc(vc);
    for (j=k=0; j<16; j++) {
        vc->vc_palette[k++] = default_red[j] ;
        vc->vc_palette[k++] = default_grn[j] ;
        vc->vc_palette[k++] = default_blu[j] ;
    }
    vc->vc_def_color       = 0x07;   /* white */
    vc->vc_ulcolor         = default_underline_color;
    vc->vc_itcolor         = default_italic_color;
    vc->vc_halfcolor       = 0x08;   /* grey */
    init_waitqueue_head(&vc->paste_wait);
    reset_terminal(vc, do_clear);
}

/*
 * This routine initializes console interrupts, and does nothing
 * else. If you want the screen to clear, call tty_write with
 * the appropriate escape-sequence.
 */

static int __init con_init(void)
{
    const char *display_desc = NULL;
    struct vc_data *vc;
    unsigned int currcons = 0, i;

    console_lock();

    if (conswitchp)
        display_desc = conswitchp->con_startup();
    if (!display_desc) {
        fg_console = 0;
        console_unlock();
        return 0;
    }

    for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
        struct con_driver *con_driver = &registered_con_driver[i];

        if (con_driver->con == NULL) {
            con_driver->con = conswitchp;
            con_driver->desc = display_desc;
            con_driver->flag = CON_DRIVER_FLAG_INIT;
            con_driver->first = 0;
            con_driver->last = MAX_NR_CONSOLES - 1;
            break;
        }
    }

    for (i = 0; i < MAX_NR_CONSOLES; i++)
        con_driver_map[i] = conswitchp;

    if (blankinterval) {
        blank_state = blank_normal_wait;
        mod_timer(&console_timer, jiffies + (blankinterval * HZ));
    }

    for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
        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);
        vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
        vc_init(vc, vc->vc_rows, vc->vc_cols,
            currcons || !vc->vc_sw->con_save_screen);
    }
    currcons = fg_console = 0;
    master_display_fg = vc = vc_cons[currcons].d;
    set_origin(vc);
    save_screen(vc);
    gotoxy(vc, vc->vc_x, vc->vc_y);
    csi_J(vc, 0);
    update_screen(vc);
    pr_info("Console: %s %s %dx%d\n",
        vc->vc_can_do_color ? "colour" : "mono",
        display_desc, vc->vc_cols, vc->vc_rows);
    printable = 1;

    console_unlock();

#ifdef CONFIG_VT_CONSOLE
    register_console(&vt_console_driver);
#endif
    return 0;
}
console_initcall(con_init);

static const struct tty_operations con_ops = {
    .install = con_install,
    .open = con_open,
    .close = con_close,
    .write = con_write,
    .write_room = con_write_room,
    .put_char = con_put_char,
    .flush_chars = con_flush_chars,
    .chars_in_buffer = con_chars_in_buffer,
    .ioctl = vt_ioctl,
#ifdef CONFIG_COMPAT
    .compat_ioctl = vt_compat_ioctl,
#endif
    .stop = con_stop,
    .start = con_start,
    .throttle = con_throttle,
    .unthrottle = con_unthrottle,
    .resize = vt_resize,
    .shutdown = con_shutdown
};

static struct cdev vc0_cdev;

static ssize_t show_tty_active(struct device *dev,
                struct device_attribute *attr, char *buf)
{
    return sprintf(buf, "tty%d\n", fg_console + 1);
}
static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);

int __init vty_init(const struct file_operations *console_fops)
{
    cdev_init(&vc0_cdev, console_fops);
    if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
        register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
        panic("Couldn't register /dev/tty0 driver\n");
    tty0dev = device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
    if (IS_ERR(tty0dev))
        tty0dev = NULL;
    else
        WARN_ON(device_create_file(tty0dev, &dev_attr_active) < 0);

    vcs_init();

    console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
    if (!console_driver)
        panic("Couldn't allocate console driver\n");

    console_driver->name = "tty";
    console_driver->name_base = 1;
    console_driver->major = TTY_MAJOR;
    console_driver->minor_start = 1;
    console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
    console_driver->init_termios = tty_std_termios;
    if (default_utf8)
        console_driver->init_termios.c_iflag |= IUTF8;
    console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
    tty_set_operations(console_driver, &con_ops);
    if (tty_register_driver(console_driver))
        panic("Couldn't register console driver\n");
    kbd_init();
    console_map_init();
#ifdef CONFIG_MDA_CONSOLE
    mda_console_init();
#endif
    return 0;
}

#ifndef VT_SINGLE_DRIVER

static struct class *vtconsole_class;

static int bind_con_driver(const struct consw *csw, int first, int last,
               int deflt)
{
    struct module *owner = csw->owner;
    const char *desc = NULL;
    struct con_driver *con_driver;
    int i, j = -1, k = -1, retval = -ENODEV;

    if (!try_module_get(owner))
        return -ENODEV;

    console_lock();

    /* check if driver is registered */
    for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
        con_driver = &registered_con_driver[i];

        if (con_driver->con == csw) {
            desc = con_driver->desc;
            retval = 0;
            break;
        }
    }

    if (retval)
        goto err;

    if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
        csw->con_startup();
        con_driver->flag |= CON_DRIVER_FLAG_INIT;
    }

    if (deflt) {
        if (conswitchp)
            module_put(conswitchp->owner);

        __module_get(owner);
        conswitchp = csw;
    }

    first = max(first, con_driver->first);
    last = min(last, con_driver->last);

    for (i = first; i <= last; i++) {
        int old_was_color;
        struct vc_data *vc = vc_cons[i].d;

        if (con_driver_map[i])
            module_put(con_driver_map[i]->owner);
        __module_get(owner);
        con_driver_map[i] = csw;

        if (!vc || !vc->vc_sw)
            continue;

        j = i;

        if (CON_IS_VISIBLE(vc)) {
            k = i;
            save_screen(vc);
        }

        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);
        set_origin(vc);
        update_attr(vc);

        /* If the console changed between mono <-> color, then
         * the attributes in the screenbuf will be wrong.  The
         * following resets all attributes to something sane.
         */
        if (old_was_color != vc->vc_can_do_color)
            clear_buffer_attributes(vc);
    }

    pr_info("Console: switching ");
    if (!deflt)
        printk("consoles %d-%d ", first+1, last+1);
    if (j >= 0) {
        struct vc_data *vc = vc_cons[j].d;

        printk("to %s %s %dx%d\n",
               vc->vc_can_do_color ? "colour" : "mono",
               desc, vc->vc_cols, vc->vc_rows);

        if (k >= 0) {
            vc = vc_cons[k].d;
            update_screen(vc);
        }
    } else
        printk("to %s\n", desc);

    retval = 0;
err:
    console_unlock();
    module_put(owner);
    return retval;
};

#ifdef CONFIG_VT_HW_CONSOLE_BINDING
static int con_is_graphics(const struct consw *csw, int first, int last)
{
    int i, retval = 0;

    for (i = first; i <= last; i++) {
        struct vc_data *vc = vc_cons[i].d;

        if (vc && vc->vc_mode == KD_GRAPHICS) {
            retval = 1;
            break;
        }
    }

    return retval;
}

int unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
{
    struct module *owner = csw->owner;
    const struct consw *defcsw = NULL;
    struct con_driver *con_driver = NULL, *con_back = NULL;
    int i, retval = -ENODEV;

    if (!try_module_get(owner))
        return -ENODEV;

    console_lock();

    /* check if driver is registered and if it is unbindable */
    for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
        con_driver = &registered_con_driver[i];

        if (con_driver->con == csw &&
            con_driver->flag & CON_DRIVER_FLAG_MODULE) {
            retval = 0;
            break;
        }
    }

    if (retval) {
        console_unlock();
        goto err;
    }

    retval = -ENODEV;

    /* check if backup driver exists */
    for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
        con_back = &registered_con_driver[i];

        if (con_back->con &&
            !(con_back->flag & CON_DRIVER_FLAG_MODULE)) {
            defcsw = con_back->con;
            retval = 0;
            break;
        }
    }

    if (retval) {
        console_unlock();
        goto err;
    }

    if (!con_is_bound(csw)) {
        console_unlock();
        goto err;
    }

    first = max(first, con_driver->first);
    last = min(last, con_driver->last);

    for (i = first; i <= last; i++) {
        if (con_driver_map[i] == csw) {
            module_put(csw->owner);
            con_driver_map[i] = NULL;
        }
    }

    if (!con_is_bound(defcsw)) {
        const struct consw *defconsw = conswitchp;

        defcsw->con_startup();
        con_back->flag |= CON_DRIVER_FLAG_INIT;
        /*
         * vgacon may change the default driver to point
         * to dummycon, we restore it here...
         */
        conswitchp = defconsw;
    }

    if (!con_is_bound(csw))
        con_driver->flag &= ~CON_DRIVER_FLAG_INIT;

    console_unlock();
    /* ignore return value, binding should not fail */
    bind_con_driver(defcsw, first, last, deflt);
err:
    module_put(owner);
    return retval;

}
EXPORT_SYMBOL(unbind_con_driver);

static int vt_bind(struct con_driver *con)
{
    const struct consw *defcsw = NULL, *csw = NULL;
    int i, more = 1, first = -1, last = -1, deflt = 0;

    if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
        con_is_graphics(con->con, con->first, con->last))
        goto err;

    csw = con->con;

    for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
        struct con_driver *con = &registered_con_driver[i];

        if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
            defcsw = con->con;
            break;
        }
    }

    if (!defcsw)
        goto err;

    while (more) {
        more = 0;

        for (i = con->first; i <= con->last; i++) {
            if (con_driver_map[i] == defcsw) {
                if (first == -1)
                    first = i;
                last = i;
                more = 1;
            } else if (first != -1)
                break;
        }

        if (first == 0 && last == MAX_NR_CONSOLES -1)
            deflt = 1;

        if (first != -1)
            bind_con_driver(csw, first, last, deflt);

        first = -1;
        last = -1;
        deflt = 0;
    }

err:
    return 0;
}

static int vt_unbind(struct con_driver *con)
{
    const struct consw *csw = NULL;
    int i, more = 1, first = -1, last = -1, deflt = 0;

    if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
        con_is_graphics(con->con, con->first, con->last))
        goto err;

    csw = con->con;

    while (more) {
        more = 0;

        for (i = con->first; i <= con->last; i++) {
            if (con_driver_map[i] == csw) {
                if (first == -1)
                    first = i;
                last = i;
                more = 1;
            } else if (first != -1)
                break;
        }

        if (first == 0 && last == MAX_NR_CONSOLES -1)
            deflt = 1;

        if (first != -1)
            unbind_con_driver(csw, first, last, deflt);

        first = -1;
        last = -1;
        deflt = 0;
    }

err:
    return 0;
}
#else
static inline int vt_bind(struct con_driver *con)
{
    return 0;
}
static inline int vt_unbind(struct con_driver *con)
{
    return 0;
}
#endif /* CONFIG_VT_HW_CONSOLE_BINDING */

static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
              const char *buf, size_t count)
{
    struct con_driver *con = dev_get_drvdata(dev);
    int bind = simple_strtoul(buf, NULL, 0);

    if (bind)
        vt_bind(con);
    else
        vt_unbind(con);

    return count;
}

static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
             char *buf)
{
    struct con_driver *con = dev_get_drvdata(dev);
    int bind = con_is_bound(con->con);

    return snprintf(buf, PAGE_SIZE, "%i\n", bind);
}

static ssize_t show_name(struct device *dev, struct device_attribute *attr,
             char *buf)
{
    struct con_driver *con = dev_get_drvdata(dev);

    return snprintf(buf, PAGE_SIZE, "%s %s\n",
            (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
             con->desc);

}

static struct device_attribute device_attrs[] = {
    __ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind),
    __ATTR(name, S_IRUGO, show_name, NULL),
};

static int vtconsole_init_device(struct con_driver *con)
{
    int i;
    int error = 0;

    con->flag |= CON_DRIVER_FLAG_ATTR;
    dev_set_drvdata(con->dev, con);
    for (i = 0; i < ARRAY_SIZE(device_attrs); i++) {
        error = device_create_file(con->dev, &device_attrs[i]);
        if (error)
            break;
    }

    if (error) {
        while (--i >= 0)
            device_remove_file(con->dev, &device_attrs[i]);
        con->flag &= ~CON_DRIVER_FLAG_ATTR;
    }

    return error;
}

static void vtconsole_deinit_device(struct con_driver *con)
{
    int i;

    if (con->flag & CON_DRIVER_FLAG_ATTR) {
        for (i = 0; i < ARRAY_SIZE(device_attrs); i++)
            device_remove_file(con->dev, &device_attrs[i]);
        con->flag &= ~CON_DRIVER_FLAG_ATTR;
    }
}

int con_is_bound(const struct consw *csw)
{
    int i, bound = 0;

    for (i = 0; i < MAX_NR_CONSOLES; i++) {
        if (con_driver_map[i] == csw) {
            bound = 1;
            break;
        }
    }

    return bound;
}
EXPORT_SYMBOL(con_is_bound);

int 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;
    saved_vc_mode = vc->vc_mode;
    saved_console_blanked = console_blanked;
    vc->vc_mode = KD_TEXT;
    console_blanked = 0;
    if (vc->vc_sw->con_debug_enter)
        ret = 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) {
        int linecount;
        char lns[4];
        const char *setargs[3] = {
            "set",
            "LINES",
            lns,
        };
        if (kdbgetintenv(setargs[0], &linecount)) {
            snprintf(lns, 4, "%i", vc->vc_rows);
            kdb_set(2, setargs);
        }
    }
    if (vc->vc_cols < 999) {
        int colcount;
        char cols[4];
        const char *setargs[3] = {
            "set",
            "COLUMNS",
            cols,
        };
        if (kdbgetintenv(setargs[0], &colcount)) {
            snprintf(cols, 4, "%i", vc->vc_cols);
            kdb_set(2, setargs);
        }
    }
#endif /* CONFIG_KGDB_KDB */
    return ret;
}
EXPORT_SYMBOL_GPL(con_debug_enter);

int con_debug_leave(void)
{
    struct vc_data *vc;
    int ret = 0;

    fg_console = saved_fg_console;
    last_console = saved_last_console;
    want_console = saved_want_console;
    console_blanked = saved_console_blanked;
    vc_cons[fg_console].d->vc_mode = saved_vc_mode;

    vc = vc_cons[fg_console].d;
    if (vc->vc_sw->con_debug_leave)
        ret = vc->vc_sw->con_debug_leave(vc);
    return ret;
}
EXPORT_SYMBOL_GPL(con_debug_leave);

int register_con_driver(const struct consw *csw, int first, int last)
{
    struct module *owner = csw->owner;
    struct con_driver *con_driver;
    const char *desc;
    int i, retval = 0;

    if (!try_module_get(owner))
        return -ENODEV;

    console_lock();

    for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
        con_driver = &registered_con_driver[i];

        /* already registered */
        if (con_driver->con == csw)
            retval = -EBUSY;
    }

    if (retval)
        goto err;

    desc = csw->con_startup();

    if (!desc)
        goto err;

    retval = -EINVAL;

    for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
        con_driver = &registered_con_driver[i];

        if (con_driver->con == NULL) {
            con_driver->con = csw;
            con_driver->desc = desc;
            con_driver->node = i;
            con_driver->flag = CON_DRIVER_FLAG_MODULE |
                               CON_DRIVER_FLAG_INIT;
            con_driver->first = first;
            con_driver->last = last;
            retval = 0;
            break;
        }
    }

    if (retval)
        goto err;

    con_driver->dev = device_create(vtconsole_class, NULL,
                        MKDEV(0, con_driver->node),
                        NULL, "vtcon%i",
                        con_driver->node);

    if (IS_ERR(con_driver->dev)) {
        printk(KERN_WARNING "Unable to create device for %s; "
               "errno = %ld\n", con_driver->desc,
               PTR_ERR(con_driver->dev));
        con_driver->dev = NULL;
    } else {
        vtconsole_init_device(con_driver);
    }

err:
    console_unlock();
    module_put(owner);
    return retval;
}
EXPORT_SYMBOL(register_con_driver);

int unregister_con_driver(const struct consw *csw)
{
    int i, retval = -ENODEV;

    console_lock();

    /* cannot unregister a bound driver */
    if (con_is_bound(csw))
        goto err;

    for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
        struct con_driver *con_driver = &registered_con_driver[i];

        if (con_driver->con == csw &&
            con_driver->flag & CON_DRIVER_FLAG_MODULE) {
            vtconsole_deinit_device(con_driver);
            device_destroy(vtconsole_class,
                       MKDEV(0, con_driver->node));
            con_driver->con = NULL;
            con_driver->desc = NULL;
            con_driver->dev = NULL;
            con_driver->node = 0;
            con_driver->flag = 0;
            con_driver->first = 0;
            con_driver->last = 0;
            retval = 0;
            break;
        }
    }
err:
    console_unlock();
    return retval;
}
EXPORT_SYMBOL(unregister_con_driver);

/*
 *  If we support more console drivers, this function is used
 *  when a driver wants to take over some existing consoles
 *  and become default driver for newly opened ones.
 *
 *      take_over_console is basically a register followed by unbind
 */
int take_over_console(const struct consw *csw, int first, int last, int deflt)
{
    int err;

    err = register_con_driver(csw, first, last);
    /* if we get an busy error we still want to bind the console driver
     * and return success, as we may have unbound the console driver
     * but not unregistered it.
    */
    if (err == -EBUSY)
        err = 0;
    if (!err)
        bind_con_driver(csw, first, last, deflt);

    return err;
}

/*
 * give_up_console is a wrapper to unregister_con_driver. It will only
 * work if driver is fully unbound.
 */
void give_up_console(const struct consw *csw)
{
    unregister_con_driver(csw);
}

static int __init vtconsole_class_init(void)
{
    int i;

    vtconsole_class = class_create(THIS_MODULE, "vtconsole");
    if (IS_ERR(vtconsole_class)) {
        printk(KERN_WARNING "Unable to create vt console class; "
               "errno = %ld\n", PTR_ERR(vtconsole_class));
        vtconsole_class = NULL;
    }

    /* Add system drivers to sysfs */
    for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
        struct con_driver *con = &registered_con_driver[i];

        if (con->con && !con->dev) {
            con->dev = device_create(vtconsole_class, NULL,
                             MKDEV(0, con->node),
                             NULL, "vtcon%i",
                             con->node);

            if (IS_ERR(con->dev)) {
                printk(KERN_WARNING "Unable to create "
                       "device for %s; errno = %ld\n",
                       con->desc, PTR_ERR(con->dev));
                con->dev = NULL;
            } else {
                vtconsole_init_device(con);
            }
        }
    }

    return 0;
}
postcore_initcall(vtconsole_class_init);

#endif

/*
 *  Screen blanking
 */

static int set_vesa_blanking(char __user *p)
{
    unsigned int mode;

    if (get_user(mode, p + 1))
        return -EFAULT;

    vesa_blank_mode = (mode < 4) ? mode : 0;
    return 0;
}

void do_blank_screen(int entering_gfx)
{
    struct vc_data *vc = vc_cons[fg_console].d;
    int i;

    WARN_CONSOLE_UNLOCKED();

    if (console_blanked) {
        if (blank_state == blank_vesa_wait) {
            blank_state = blank_off;
            vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
        }
        return;
    }

    /* entering graphics mode? */
    if (entering_gfx) {
        hide_cursor(vc);
        save_screen(vc);
        vc->vc_sw->con_blank(vc, -1, 1);
        console_blanked = fg_console + 1;
        blank_state = blank_off;
        set_origin(vc);
        return;
    }

    if (blank_state != blank_normal_wait)
        return;
    blank_state = blank_off;

    /* don't blank graphics */
    if (vc->vc_mode != KD_TEXT) {
        console_blanked = fg_console + 1;
        return;
    }

    hide_cursor(vc);
    del_timer_sync(&console_timer);
    blank_timer_expired = 0;

    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);
    console_blanked = fg_console + 1;
    if (i)
        set_origin(vc);

    if (console_blank_hook && console_blank_hook(1))
        return;

    if (vesa_off_interval && vesa_blank_mode) {
        blank_state = blank_vesa_wait;
        mod_timer(&console_timer, jiffies + vesa_off_interval);
    }
    vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
}
EXPORT_SYMBOL(do_blank_screen);

/*
 * Called by timer as well as from vt_console_driver
 */
void do_unblank_screen(int leaving_gfx)
{
    struct vc_data *vc;

    /* This should now always be called from a "sane" (read: can schedule)
     * context for the sake of the low level drivers, except in the special
     * case of oops_in_progress
     */
    if (!oops_in_progress)
        might_sleep();

    WARN_CONSOLE_UNLOCKED();

    ignore_poke = 0;
    if (!console_blanked)
        return;
    if (!vc_cons_allocated(fg_console)) {
        /* impossible */
        pr_warning("unblank_screen: tty %d not allocated ??\n",
               fg_console+1);
        return;
    }
    vc = vc_cons[fg_console].d;
    /* Try to unblank in oops case too */
    if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
        return; /* but leave console_blanked != 0 */

    if (blankinterval) {
        mod_timer(&console_timer, jiffies + (blankinterval * HZ));
        blank_state = blank_normal_wait;
    }

    console_blanked = 0;
    if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
        /* Low-level driver cannot restore -> do it ourselves */
        update_screen(vc);
    if (console_blank_hook)
        console_blank_hook(0);
    set_palette(vc);
    set_cursor(vc);
    vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
}
EXPORT_SYMBOL(do_unblank_screen);

/*
 * This is called by the outside world to cause a forced unblank, mostly for
 * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
 * call it with 1 as an argument and so force a mode restore... that may kill
 * X or at least garbage the screen but would also make the Oops visible...
 */
void unblank_screen(void)
{
    do_unblank_screen(0);
}

/*
 * We defer the timer blanking to work queue so it can take the console mutex
 * (console operations can still happen at irq time, but only from printk which
 * has the console mutex. Not perfect yet, but better than no locking
 */
static void blank_screen_t(unsigned long dummy)
{
    if (unlikely(!keventd_up())) {
        mod_timer(&console_timer, jiffies + (blankinterval * HZ));
        return;
    }
    blank_timer_expired = 1;
    schedule_work(&console_work);
}

void poke_blanked_console(void)
{
    WARN_CONSOLE_UNLOCKED();

    /* Add this so we quickly catch whoever might call us in a non
     * safe context. Nowadays, unblank_screen() isn't to be called in
     * atomic contexts and is allowed to schedule (with the special case
     * of oops_in_progress, but that isn't of any concern for this
     * function. --BenH.
     */
    might_sleep();

    /* This isn't perfectly race free, but a race here would be mostly harmless,
     * at worse, we'll do a spurrious blank and it's unlikely
     */
    del_timer(&console_timer);
    blank_timer_expired = 0;

    if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
        return;
    if (console_blanked)
        unblank_screen();
    else if (blankinterval) {
        mod_timer(&console_timer, jiffies + (blankinterval * HZ));
        blank_state = blank_normal_wait;
    }
}

/*
 *  Palettes
 */

static void set_palette(struct vc_data *vc)
{
    WARN_CONSOLE_UNLOCKED();

    if (vc->vc_mode != KD_GRAPHICS)
        vc->vc_sw->con_set_palette(vc, color_table);
}

/*
 * Load palette into the DAC registers. arg points to a colour
 * map, 3 bytes per colour, 16 colours, range from 0 to 255.
 */

int con_set_cmap(unsigned char __user *arg)
{
    int i, j, k;
    unsigned char colormap[3*16];

    if (copy_from_user(colormap, arg, sizeof(colormap)))
        return -EFAULT;

    console_lock();
    for (i = k = 0; i < 16; i++) {
        default_red[i] = colormap[k++];
        default_grn[i] = colormap[k++];
        default_blu[i] = colormap[k++];
    }
    for (i = 0; i < MAX_NR_CONSOLES; i++) {
        if (!vc_cons_allocated(i))
            continue;
        for (j = k = 0; j < 16; j++) {
            vc_cons[i].d->vc_palette[k++] = default_red[j];
            vc_cons[i].d->vc_palette[k++] = default_grn[j];
            vc_cons[i].d->vc_palette[k++] = default_blu[j];
        }
        set_palette(vc_cons[i].d);
    }
    console_unlock();

    return 0;
}

int con_get_cmap(unsigned char __user *arg)
{
    int i, k;
    unsigned char colormap[3*16];

    console_lock();
    for (i = k = 0; i < 16; i++) {
        colormap[k++] = default_red[i];
        colormap[k++] = default_grn[i];
        colormap[k++] = default_blu[i];
    }
    console_unlock();

    if (copy_to_user(arg, colormap, sizeof(colormap)))
        return -EFAULT;

    return 0;
}

void reset_palette(struct vc_data *vc)
{
    int j, k;
    for (j=k=0; j<16; j++) {
        vc->vc_palette[k++] = default_red[j];
        vc->vc_palette[k++] = default_grn[j];
        vc->vc_palette[k++] = default_blu[j];
    }
    set_palette(vc);
}

/*
 *  Font switching
 *
 *  Currently we only support fonts up to 32 pixels wide, at a maximum height
 *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints, 
 *  depending on width) reserved for each character which is kinda wasty, but 
 *  this is done in order to maintain compatibility with the EGA/VGA fonts. It 
 *  is up to the actual low-level console-driver convert data into its favorite
 *  format (maybe we should add a `fontoffset' field to the `display'
 *  structure so we won't have to convert the fontdata all the time.
 *  /Jes
 */

#define max_font_size 65536

static int con_font_get(struct vc_data *vc, struct console_font_op *op)
{
    struct console_font font;
    int rc = -EINVAL;
    int c;

    if (op->data) {
        font.data = kmalloc(max_font_size, GFP_KERNEL);
        if (!font.data)
            return -ENOMEM;
    } else
        font.data = NULL;

    console_lock();
    if (vc->vc_mode != KD_TEXT)
        rc = -EINVAL;
    else if (vc->vc_sw->con_font_get)
        rc = vc->vc_sw->con_font_get(vc, &font);
    else
        rc = -ENOSYS;
    console_unlock();

    if (rc)
        goto out;

    c = (font.width+7)/8 * 32 * font.charcount;

    if (op->data && font.charcount > op->charcount)
        rc = -ENOSPC;
    if (!(op->flags & KD_FONT_FLAG_OLD)) {
        if (font.width > op->width || font.height > op->height) 
            rc = -ENOSPC;
    } else {
        if (font.width != 8)
            rc = -EIO;
        else if ((op->height && font.height > op->height) ||
             font.height > 32)
            rc = -ENOSPC;
    }
    if (rc)
        goto out;

    op->height = font.height;
    op->width = font.width;
    op->charcount = font.charcount;

    if (op->data && copy_to_user(op->data, font.data, c))
        rc = -EFAULT;

out:
    kfree(font.data);
    return rc;
}

static int con_font_set(struct vc_data *vc, struct console_font_op *op)
{
    struct console_font font;
    int rc = -EINVAL;
    int size;

    if (vc->vc_mode != KD_TEXT)
        return -EINVAL;
    if (!op->data)
        return -EINVAL;
    if (op->charcount > 512)
        return -EINVAL;
    if (!op->height) {      /* Need to guess font height [compat] */
        int h, i;
        u8 __user *charmap = op->data;
        u8 tmp;
        
        /* If from KDFONTOP ioctl, don't allow things which can be done in userland,
           so that we can get rid of this soon */
        if (!(op->flags & KD_FONT_FLAG_OLD))
            return -EINVAL;
        for (h = 32; h > 0; h--)
            for (i = 0; i < op->charcount; i++) {
                if (get_user(tmp, &charmap[32*i+h-1]))
                    return -EFAULT;
                if (tmp)
                    goto nonzero;
            }
        return -EINVAL;
    nonzero:
        op->height = h;
    }
    if (op->width <= 0 || op->width > 32 || op->height > 32)
        return -EINVAL;
    size = (op->width+7)/8 * 32 * op->charcount;
    if (size > max_font_size)
        return -ENOSPC;
    font.charcount = op->charcount;
    font.height = op->height;
    font.width = op->width;
    font.data = memdup_user(op->data, size);
    if (IS_ERR(font.data))
        return PTR_ERR(font.data);
    console_lock();
    if (vc->vc_mode != KD_TEXT)
        rc = -EINVAL;
    else if (vc->vc_sw->con_font_set)
        rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
    else
        rc = -ENOSYS;
    console_unlock();
    kfree(font.data);
    return rc;
}

static int con_font_default(struct vc_data *vc, struct console_font_op *op)
{
    struct console_font font = {.width = op->width, .height = op->height};
    char name[MAX_FONT_NAME];
    char *s = name;
    int rc;


    if (!op->data)
        s = NULL;
    else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
        return -EFAULT;
    else
        name[MAX_FONT_NAME - 1] = 0;

    console_lock();
    if (vc->vc_mode != KD_TEXT) {
        console_unlock();
        return -EINVAL;
    }
    if (vc->vc_sw->con_font_default)
        rc = vc->vc_sw->con_font_default(vc, &font, s);
    else
        rc = -ENOSYS;
    console_unlock();
    if (!rc) {
        op->width = font.width;
        op->height = font.height;
    }
    return rc;
}

static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
{
    int con = op->height;
    int rc;


    console_lock();
    if (vc->vc_mode != KD_TEXT)
        rc = -EINVAL;
    else if (!vc->vc_sw->con_font_copy)
        rc = -ENOSYS;
    else if (con < 0 || !vc_cons_allocated(con))
        rc = -ENOTTY;
    else if (con == vc->vc_num) /* nothing to do */
        rc = 0;
    else
        rc = vc->vc_sw->con_font_copy(vc, con);
    console_unlock();
    return rc;
}

int con_font_op(struct vc_data *vc, struct console_font_op *op)
{
    switch (op->op) {
    case KD_FONT_OP_SET:
        return con_font_set(vc, op);
    case KD_FONT_OP_GET:
        return con_font_get(vc, op);
    case KD_FONT_OP_SET_DEFAULT:
        return con_font_default(vc, op);
    case KD_FONT_OP_COPY:
        return con_font_copy(vc, op);
    }
    return -ENOSYS;
}

/*
 *  Interface exported to selection and vcs.
 */

/* used by selection */
u16 screen_glyph(struct vc_data *vc, int offset)
{
    u16 w = scr_readw(screenpos(vc, offset, 1));
    u16 c = w & 0xff;

    if (w & vc->vc_hi_font_mask)
        c |= 0x100;
    return c;
}
EXPORT_SYMBOL_GPL(screen_glyph);

/* used by vcs - note the word offset */
unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
{
    return screenpos(vc, 2 * w_offset, viewed);
}

void getconsxy(struct vc_data *vc, unsigned char *p)
{
    p[0] = vc->vc_x;
    p[1] = vc->vc_y;
}

void putconsxy(struct vc_data *vc, unsigned char *p)
{
    hide_cursor(vc);
    gotoxy(vc, p[0], p[1]);
    set_cursor(vc);
}

u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
{
    if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
        return softcursor_original;
    return scr_readw(org);
}

void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
{
    scr_writew(val, org);
    if ((unsigned long)org == vc->vc_pos) {
        softcursor_original = -1;
        add_softcursor(vc);
    }
}

void vcs_scr_updated(struct vc_data *vc)
{
    notify_update(vc);
}

/*
 *  Visible symbols for modules
 */

EXPORT_SYMBOL(color_table);
EXPORT_SYMBOL(default_red);
EXPORT_SYMBOL(default_grn);
EXPORT_SYMBOL(default_blu);
EXPORT_SYMBOL(update_region);
EXPORT_SYMBOL(redraw_screen);
EXPORT_SYMBOL(vc_resize);
EXPORT_SYMBOL(fg_console);
EXPORT_SYMBOL(console_blank_hook);
EXPORT_SYMBOL(console_blanked);
EXPORT_SYMBOL(vc_cons);
EXPORT_SYMBOL(global_cursor_default);
#ifndef VT_SINGLE_DRIVER
EXPORT_SYMBOL(take_over_console);
EXPORT_SYMBOL(give_up_console);
#endif