/*
 *  linux/drivers/video/fbcon.c -- Low level frame buffer based console driver
 *
 *      Copyright (C) 1995 Geert Uytterhoeven
 *
 *
 *  This file is based on the original Amiga console driver (amicon.c):
 *
 *      Copyright (C) 1993 Hamish Macdonald
 *                         Greg Harp
 *      Copyright (C) 1994 David Carter [carter@compsci.bristol.ac.uk]
 *
 *            with work by William Rucklidge (wjr@cs.cornell.edu)
 *                         Geert Uytterhoeven
 *                         Jes Sorensen (jds@kom.auc.dk)
 *                         Martin Apel
 *
 *  and on the original Atari console driver (atacon.c):
 *
 *      Copyright (C) 1993 Bjoern Brauel
 *                         Roman Hodek
 *
 *            with work by Guenther Kelleter
 *                         Martin Schaller
 *                         Andreas Schwab
 *
 *  Hardware cursor support added by Emmanuel Marty (core@ggi-project.org)
 *  Smart redraw scrolling, arbitrary font width support, 512char font support
 *  and software scrollback added by 
 *                         Jakub Jelinek (jj@ultra.linux.cz)
 *
 *  Random hacking by Martin Mares <mj@ucw.cz>
 *
 *      2001 - Documented with DocBook
 *      - Brad Douglas <brad@neruo.com>
 *
 *  The low level operations for the various display memory organizations are
 *  now in separate source files.
 *
 *  Currently the following organizations are supported:
 *
 *    o afb                     Amiga bitplanes
 *    o cfb{2,4,8,16,24,32}     Packed pixels
 *    o ilbm                    Amiga interleaved bitplanes
 *    o iplan2p[248]            Atari interleaved bitplanes
 *    o mfb                     Monochrome
 *    o vga                     VGA characters/attributes
 *
 *  To do:
 *
 *    - Implement 16 plane mode (iplan2p16)
 *
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License.  See the file COPYING in the main directory of this archive for
 *  more details.
 */

#undef FBCONDEBUG

#include <linux/module.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/delay.h>        /* MSch: for IRQ probe */
#include <linux/console.h>
#include <linux/string.h>
#include <linux/kd.h>
#include <linux/slab.h>
#include <linux/fb.h>
#include <linux/vt_kern.h>
#include <linux/selection.h>
#include <linux/font.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/crc32.h> /* For counting font checksums */
#include <asm/fb.h>
#include <asm/irq.h>

#include "fbcon.h"

#ifdef FBCONDEBUG
#  define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt, __func__ , ## args)
#else
#  define DPRINTK(fmt, args...)
#endif

enum {
        FBCON_LOGO_CANSHOW      = -1,   /* the logo can be shown */
        FBCON_LOGO_DRAW         = -2,   /* draw the logo to a console */
        FBCON_LOGO_DONTSHOW     = -3    /* do not show the logo */
};

static struct display fb_display[MAX_NR_CONSOLES];

static signed char con2fb_map[MAX_NR_CONSOLES];
static signed char con2fb_map_boot[MAX_NR_CONSOLES];

static int logo_lines;
/* logo_shown is an index to vc_cons when >= 0; otherwise follows FBCON_LOGO
   enums.  */
static int logo_shown = FBCON_LOGO_CANSHOW;
/* Software scrollback */
static int fbcon_softback_size = 32768;
static unsigned long softback_buf, softback_curr;
static unsigned long softback_in;
static unsigned long softback_top, softback_end;
static int softback_lines;
/* console mappings */
static int first_fb_vc;
static int last_fb_vc = MAX_NR_CONSOLES - 1;
static int fbcon_is_default = 1; 
static int fbcon_has_exited;
static int primary_device = -1;
static int fbcon_has_console_bind;

#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY
static int map_override;

static inline void fbcon_map_override(void)
{
        map_override = 1;
}
#else
static inline void fbcon_map_override(void)
{
}
#endif /* CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY */

/* font data */
static char fontname[40];

/* current fb_info */
static int info_idx = -1;

/* console rotation */
static int initial_rotation;
static int fbcon_has_sysfs;

static const struct consw fb_con;

#define CM_SOFTBACK     (8)

#define advance_row(p, delta) (unsigned short *)((unsigned long)(p) + (delta) * vc->vc_size_row)

static int fbcon_set_origin(struct vc_data *);

#define CURSOR_DRAW_DELAY               (1)

static int vbl_cursor_cnt;
static int fbcon_cursor_noblink;

#define divides(a, b)   ((!(a) || (b)%(a)) ? 0 : 1)

/*
 *  Interface used by the world
 */

static const char *fbcon_startup(void);
static void fbcon_init(struct vc_data *vc, int init);
static void fbcon_deinit(struct vc_data *vc);
static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height,
                        int width);
static void fbcon_putc(struct vc_data *vc, int c, int ypos, int xpos);
static void fbcon_putcs(struct vc_data *vc, const unsigned short *s,
                        int count, int ypos, int xpos);
static void fbcon_clear_margins(struct vc_data *vc, int bottom_only);
static void fbcon_cursor(struct vc_data *vc, int mode);
static int fbcon_scroll(struct vc_data *vc, int t, int b, int dir,
                        int count);
static void fbcon_bmove(struct vc_data *vc, int sy, int sx, int dy, int dx,
                        int height, int width);
static int fbcon_switch(struct vc_data *vc);
static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch);
static int fbcon_set_palette(struct vc_data *vc, unsigned char *table);
static int fbcon_scrolldelta(struct vc_data *vc, int lines);

/*
 *  Internal routines
 */
static __inline__ void ywrap_up(struct vc_data *vc, int count);
static __inline__ void ywrap_down(struct vc_data *vc, int count);
static __inline__ void ypan_up(struct vc_data *vc, int count);
static __inline__ void ypan_down(struct vc_data *vc, int count);
static void fbcon_bmove_rec(struct vc_data *vc, struct display *p, int sy, int sx,
                            int dy, int dx, int height, int width, u_int y_break);
static void fbcon_set_disp(struct fb_info *info, struct fb_var_screeninfo *var,
                           int unit);
static void fbcon_redraw_move(struct vc_data *vc, struct display *p,
                              int line, int count, int dy);
static void fbcon_modechanged(struct fb_info *info);
static void fbcon_set_all_vcs(struct fb_info *info);
static void fbcon_start(void);
static void fbcon_exit(void);
static struct device *fbcon_device;

#ifdef CONFIG_FRAMEBUFFER_CONSOLE_ROTATION
static inline void fbcon_set_rotation(struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;

        if (!(info->flags & FBINFO_MISC_TILEBLITTING) &&
            ops->p->con_rotate < 4)
                ops->rotate = ops->p->con_rotate;
        else
                ops->rotate = 0;
}

static void fbcon_rotate(struct fb_info *info, u32 rotate)
{
        struct fbcon_ops *ops= info->fbcon_par;
        struct fb_info *fb_info;

        if (!ops || ops->currcon == -1)
                return;

        fb_info = registered_fb[con2fb_map[ops->currcon]];

        if (info == fb_info) {
                struct display *p = &fb_display[ops->currcon];

                if (rotate < 4)
                        p->con_rotate = rotate;
                else
                        p->con_rotate = 0;

                fbcon_modechanged(info);
        }
}

static void fbcon_rotate_all(struct fb_info *info, u32 rotate)
{
        struct fbcon_ops *ops = info->fbcon_par;
        struct vc_data *vc;
        struct display *p;
        int i;

        if (!ops || ops->currcon < 0 || rotate > 3)
                return;

        for (i = first_fb_vc; i <= last_fb_vc; i++) {
                vc = vc_cons[i].d;
                if (!vc || vc->vc_mode != KD_TEXT ||
                    registered_fb[con2fb_map[i]] != info)
                        continue;

                p = &fb_display[vc->vc_num];
                p->con_rotate = rotate;
        }

        fbcon_set_all_vcs(info);
}
#else
static inline void fbcon_set_rotation(struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;

        ops->rotate = FB_ROTATE_UR;
}

static void fbcon_rotate(struct fb_info *info, u32 rotate)
{
        return;
}

static void fbcon_rotate_all(struct fb_info *info, u32 rotate)
{
        return;
}
#endif /* CONFIG_FRAMEBUFFER_CONSOLE_ROTATION */

static int fbcon_get_rotate(struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;

        return (ops) ? ops->rotate : 0;
}

static inline int fbcon_is_inactive(struct vc_data *vc, struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;

        return (info->state != FBINFO_STATE_RUNNING ||
                vc->vc_mode != KD_TEXT || ops->graphics) &&
                !vt_force_oops_output(vc);
}

static int get_color(struct vc_data *vc, struct fb_info *info,
              u16 c, int is_fg)
{
        int depth = fb_get_color_depth(&info->var, &info->fix);
        int color = 0;

        if (console_blanked) {
                unsigned short charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;

                c = vc->vc_video_erase_char & charmask;
        }

        if (depth != 1)
                color = (is_fg) ? attr_fgcol((vc->vc_hi_font_mask) ? 9 : 8, c)
                        : attr_bgcol((vc->vc_hi_font_mask) ? 13 : 12, c);

        switch (depth) {
        case 1:
        {
                int col = mono_col(info);
                /* 0 or 1 */
                int fg = (info->fix.visual != FB_VISUAL_MONO01) ? col : 0;
                int bg = (info->fix.visual != FB_VISUAL_MONO01) ? 0 : col;

                if (console_blanked)
                        fg = bg;

                color = (is_fg) ? fg : bg;
                break;
        }
        case 2:
                /*
                 * Scale down 16-colors to 4 colors. Default 4-color palette
                 * is grayscale. However, simply dividing the values by 4
                 * will not work, as colors 1, 2 and 3 will be scaled-down
                 * to zero rendering them invisible.  So empirically convert
                 * colors to a sane 4-level grayscale.
                 */
                switch (color) {
                case 0:
                        color = 0; /* black */
                        break;
                case 1 ... 6:
                        color = 2; /* white */
                        break;
                case 7 ... 8:
                        color = 1; /* gray */
                        break;
                default:
                        color = 3; /* intense white */
                        break;
                }
                break;
        case 3:
                /*
                 * Last 8 entries of default 16-color palette is a more intense
                 * version of the first 8 (i.e., same chrominance, different
                 * luminance).
                 */
                color &= 7;
                break;
        }


        return color;
}

static void fbcon_update_softback(struct vc_data *vc)
{
        int l = fbcon_softback_size / vc->vc_size_row;

        if (l > 5)
                softback_end = softback_buf + l * vc->vc_size_row;
        else
                /* Smaller scrollback makes no sense, and 0 would screw
                   the operation totally */
                softback_top = 0;
}

static void fb_flashcursor(struct work_struct *work)
{
        struct fb_info *info = container_of(work, struct fb_info, queue);
        struct fbcon_ops *ops = info->fbcon_par;
        struct vc_data *vc = NULL;
        int c;
        int mode;
        int ret;

        /* FIXME: we should sort out the unbind locking instead */
        /* instead we just fail to flash the cursor if we can't get
         * the lock instead of blocking fbcon deinit */
        ret = console_trylock();
        if (ret == 0)
                return;

        if (ops && ops->currcon != -1)
                vc = vc_cons[ops->currcon].d;

        if (!vc || !CON_IS_VISIBLE(vc) ||
            registered_fb[con2fb_map[vc->vc_num]] != info ||
            vc->vc_deccm != 1) {
                console_unlock();
                return;
        }

        c = scr_readw((u16 *) vc->vc_pos);
        mode = (!ops->cursor_flash || ops->cursor_state.enable) ?
                CM_ERASE : CM_DRAW;
        ops->cursor(vc, info, mode, softback_lines, get_color(vc, info, c, 1),
                    get_color(vc, info, c, 0));
        console_unlock();
}

static void cursor_timer_handler(unsigned long dev_addr)
{
        struct fb_info *info = (struct fb_info *) dev_addr;
        struct fbcon_ops *ops = info->fbcon_par;

        queue_work(system_power_efficient_wq, &info->queue);
        mod_timer(&ops->cursor_timer, jiffies + HZ/5);
}

static void fbcon_add_cursor_timer(struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;

        if ((!info->queue.func || info->queue.func == fb_flashcursor) &&
            !(ops->flags & FBCON_FLAGS_CURSOR_TIMER) &&
            !fbcon_cursor_noblink) {
                if (!info->queue.func)
                        INIT_WORK(&info->queue, fb_flashcursor);

                init_timer(&ops->cursor_timer);
                ops->cursor_timer.function = cursor_timer_handler;
                ops->cursor_timer.expires = jiffies + HZ / 5;
                ops->cursor_timer.data = (unsigned long ) info;
                add_timer(&ops->cursor_timer);
                ops->flags |= FBCON_FLAGS_CURSOR_TIMER;
        }
}

static void fbcon_del_cursor_timer(struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;

        if (info->queue.func == fb_flashcursor &&
            ops->flags & FBCON_FLAGS_CURSOR_TIMER) {
                del_timer_sync(&ops->cursor_timer);
                ops->flags &= ~FBCON_FLAGS_CURSOR_TIMER;
        }
}

#ifndef MODULE
static int __init fb_console_setup(char *this_opt)
{
        char *options;
        int i, j;

        if (!this_opt || !*this_opt)
                return 1;

        while ((options = strsep(&this_opt, ",")) != NULL) {
                if (!strncmp(options, "font:", 5))
                        strlcpy(fontname, options + 5, sizeof(fontname));
                
                if (!strncmp(options, "scrollback:", 11)) {
                        options += 11;
                        if (*options) {
                                fbcon_softback_size = simple_strtoul(options, &options, 0);
                                if (*options == 'k' || *options == 'K') {
                                        fbcon_softback_size *= 1024;
                                        options++;
                                }
                                if (*options != ',')
                                        return 1;
                                options++;
                        } else
                                return 1;
                }
                
                if (!strncmp(options, "map:", 4)) {
                        options += 4;
                        if (*options) {
                                for (i = 0, j = 0; i < MAX_NR_CONSOLES; i++) {
                                        if (!options[j])
                                                j = 0;
                                        con2fb_map_boot[i] =
                                                (options[j++]-'0') % FB_MAX;
                                }

                                fbcon_map_override();
                        }

                        return 1;
                }

                if (!strncmp(options, "vc:", 3)) {
                        options += 3;
                        if (*options)
                                first_fb_vc = simple_strtoul(options, &options, 10) - 1;
                        if (first_fb_vc < 0)
                                first_fb_vc = 0;
                        if (*options++ == '-')
                                last_fb_vc = simple_strtoul(options, &options, 10) - 1;
                        fbcon_is_default = 0; 
                }       

                if (!strncmp(options, "rotate:", 7)) {
                        options += 7;
                        if (*options)
                                initial_rotation = simple_strtoul(options, &options, 0);
                        if (initial_rotation > 3)
                                initial_rotation = 0;
                }
        }
        return 1;
}

__setup("fbcon=", fb_console_setup);
#endif

static int search_fb_in_map(int idx)
{
        int i, retval = 0;

        for (i = first_fb_vc; i <= last_fb_vc; i++) {
                if (con2fb_map[i] == idx)
                        retval = 1;
        }
        return retval;
}

static int search_for_mapped_con(void)
{
        int i, retval = 0;

        for (i = first_fb_vc; i <= last_fb_vc; i++) {
                if (con2fb_map[i] != -1)
                        retval = 1;
        }
        return retval;
}

static int do_fbcon_takeover(int show_logo)
{
        int err, i;

        if (!num_registered_fb)
                return -ENODEV;

        if (!show_logo)
                logo_shown = FBCON_LOGO_DONTSHOW;

        for (i = first_fb_vc; i <= last_fb_vc; i++)
                con2fb_map[i] = info_idx;

        err = do_take_over_console(&fb_con, first_fb_vc, last_fb_vc,
                                fbcon_is_default);

        if (err) {
                for (i = first_fb_vc; i <= last_fb_vc; i++)
                        con2fb_map[i] = -1;
                info_idx = -1;
        } else {
                fbcon_has_console_bind = 1;
        }

        return err;
}

#ifdef MODULE
static void fbcon_prepare_logo(struct vc_data *vc, struct fb_info *info,
                               int cols, int rows, int new_cols, int new_rows)
{
        logo_shown = FBCON_LOGO_DONTSHOW;
}
#else
static void fbcon_prepare_logo(struct vc_data *vc, struct fb_info *info,
                               int cols, int rows, int new_cols, int new_rows)
{
        /* Need to make room for the logo */
        struct fbcon_ops *ops = info->fbcon_par;
        int cnt, erase = vc->vc_video_erase_char, step;
        unsigned short *save = NULL, *r, *q;
        int logo_height;

        if (info->flags & FBINFO_MODULE) {
                logo_shown = FBCON_LOGO_DONTSHOW;
                return;
        }

        /*
         * remove underline attribute from erase character
         * if black and white framebuffer.
         */
        if (fb_get_color_depth(&info->var, &info->fix) == 1)
                erase &= ~0x400;
        logo_height = fb_prepare_logo(info, ops->rotate);
        logo_lines = DIV_ROUND_UP(logo_height, vc->vc_font.height);
        q = (unsigned short *) (vc->vc_origin +
                                vc->vc_size_row * rows);
        step = logo_lines * cols;
        for (r = q - logo_lines * cols; r < q; r++)
                if (scr_readw(r) != vc->vc_video_erase_char)
                        break;
        if (r != q && new_rows >= rows + logo_lines) {
                save = kmalloc(logo_lines * new_cols * 2, GFP_KERNEL);
                if (save) {
                        int i = cols < new_cols ? cols : new_cols;
                        scr_memsetw(save, erase, logo_lines * new_cols * 2);
                        r = q - step;
                        for (cnt = 0; cnt < logo_lines; cnt++, r += i)
                                scr_memcpyw(save + cnt * new_cols, r, 2 * i);
                        r = q;
                }
        }
        if (r == q) {
                /* We can scroll screen down */
                r = q - step - cols;
                for (cnt = rows - logo_lines; cnt > 0; cnt--) {
                        scr_memcpyw(r + step, r, vc->vc_size_row);
                        r -= cols;
                }
                if (!save) {
                        int lines;
                        if (vc->vc_y + logo_lines >= rows)
                                lines = rows - vc->vc_y - 1;
                        else
                                lines = logo_lines;
                        vc->vc_y += lines;
                        vc->vc_pos += lines * vc->vc_size_row;
                }
        }
        scr_memsetw((unsigned short *) vc->vc_origin,
                    erase,
                    vc->vc_size_row * logo_lines);

        if (CON_IS_VISIBLE(vc) && vc->vc_mode == KD_TEXT) {
                fbcon_clear_margins(vc, 0);
                update_screen(vc);
        }

        if (save) {
                q = (unsigned short *) (vc->vc_origin +
                                        vc->vc_size_row *
                                        rows);
                scr_memcpyw(q, save, logo_lines * new_cols * 2);
                vc->vc_y += logo_lines;
                vc->vc_pos += logo_lines * vc->vc_size_row;
                kfree(save);
        }

        if (logo_lines > vc->vc_bottom) {
                logo_shown = FBCON_LOGO_CANSHOW;
                printk(KERN_INFO
                       "fbcon_init: disable boot-logo (boot-logo bigger than screen).\n");
        } else if (logo_shown != FBCON_LOGO_DONTSHOW) {
                logo_shown = FBCON_LOGO_DRAW;
                vc->vc_top = logo_lines;
        }
}
#endif /* MODULE */

#ifdef CONFIG_FB_TILEBLITTING
static void set_blitting_type(struct vc_data *vc, struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;

        ops->p = &fb_display[vc->vc_num];

        if ((info->flags & FBINFO_MISC_TILEBLITTING))
                fbcon_set_tileops(vc, info);
        else {
                fbcon_set_rotation(info);
                fbcon_set_bitops(ops);
        }
}

static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount)
{
        int err = 0;

        if (info->flags & FBINFO_MISC_TILEBLITTING &&
            info->tileops->fb_get_tilemax(info) < charcount)
                err = 1;

        return err;
}
#else
static void set_blitting_type(struct vc_data *vc, struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;

        info->flags &= ~FBINFO_MISC_TILEBLITTING;
        ops->p = &fb_display[vc->vc_num];
        fbcon_set_rotation(info);
        fbcon_set_bitops(ops);
}

static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount)
{
        return 0;
}

#endif /* CONFIG_MISC_TILEBLITTING */


static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info,
                                  int unit, int oldidx)
{
        struct fbcon_ops *ops = NULL;
        int err = 0;

        if (!try_module_get(info->fbops->owner))
                err = -ENODEV;

        if (!err && info->fbops->fb_open &&
            info->fbops->fb_open(info, 0))
                err = -ENODEV;

        if (!err) {
                ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
                if (!ops)
                        err = -ENOMEM;
        }

        if (!err) {
                info->fbcon_par = ops;

                if (vc)
                        set_blitting_type(vc, info);
        }

        if (err) {
                con2fb_map[unit] = oldidx;
                module_put(info->fbops->owner);
        }

        return err;
}

static int con2fb_release_oldinfo(struct vc_data *vc, struct fb_info *oldinfo,
                                  struct fb_info *newinfo, int unit,
                                  int oldidx, int found)
{
        struct fbcon_ops *ops = oldinfo->fbcon_par;
        int err = 0, ret;

        if (oldinfo->fbops->fb_release &&
            oldinfo->fbops->fb_release(oldinfo, 0)) {
                con2fb_map[unit] = oldidx;
                if (!found && newinfo->fbops->fb_release)
                        newinfo->fbops->fb_release(newinfo, 0);
                if (!found)
                        module_put(newinfo->fbops->owner);
                err = -ENODEV;
        }

        if (!err) {
                fbcon_del_cursor_timer(oldinfo);
                kfree(ops->cursor_state.mask);
                kfree(ops->cursor_data);
                kfree(ops->fontbuffer);
                kfree(oldinfo->fbcon_par);
                oldinfo->fbcon_par = NULL;
                module_put(oldinfo->fbops->owner);
                /*
                  If oldinfo and newinfo are driving the same hardware,
                  the fb_release() method of oldinfo may attempt to
                  restore the hardware state.  This will leave the
                  newinfo in an undefined state. Thus, a call to
                  fb_set_par() may be needed for the newinfo.
                */
                if (newinfo->fbops->fb_set_par) {
                        ret = newinfo->fbops->fb_set_par(newinfo);

                        if (ret)
                                printk(KERN_ERR "con2fb_release_oldinfo: "
                                        "detected unhandled fb_set_par error, "
                                        "error code %d\n", ret);
                }
        }

        return err;
}

static void con2fb_init_display(struct vc_data *vc, struct fb_info *info,
                                int unit, int show_logo)
{
        struct fbcon_ops *ops = info->fbcon_par;
        int ret;

        ops->currcon = fg_console;

        if (info->fbops->fb_set_par && !(ops->flags & FBCON_FLAGS_INIT)) {
                ret = info->fbops->fb_set_par(info);

                if (ret)
                        printk(KERN_ERR "con2fb_init_display: detected "
                                "unhandled fb_set_par error, "
                                "error code %d\n", ret);
        }

        ops->flags |= FBCON_FLAGS_INIT;
        ops->graphics = 0;
        fbcon_set_disp(info, &info->var, unit);

        if (show_logo) {
                struct vc_data *fg_vc = vc_cons[fg_console].d;
                struct fb_info *fg_info =
                        registered_fb[con2fb_map[fg_console]];

                fbcon_prepare_logo(fg_vc, fg_info, fg_vc->vc_cols,
                                   fg_vc->vc_rows, fg_vc->vc_cols,
                                   fg_vc->vc_rows);
        }

        update_screen(vc_cons[fg_console].d);
}

/**
 *      set_con2fb_map - map console to frame buffer device
 *      @unit: virtual console number to map
 *      @newidx: frame buffer index to map virtual console to
 *      @user: user request
 *
 *      Maps a virtual console @unit to a frame buffer device
 *      @newidx.
 *
 *      This should be called with the console lock held.
 */
static int set_con2fb_map(int unit, int newidx, int user)
{
        struct vc_data *vc = vc_cons[unit].d;
        int oldidx = con2fb_map[unit];
        struct fb_info *info = registered_fb[newidx];
        struct fb_info *oldinfo = NULL;
        int found, err = 0;

        if (oldidx == newidx)
                return 0;

        if (!info)
                return -EINVAL;

        if (!search_for_mapped_con() || !con_is_bound(&fb_con)) {
                info_idx = newidx;
                return do_fbcon_takeover(0);
        }

        if (oldidx != -1)
                oldinfo = registered_fb[oldidx];

        found = search_fb_in_map(newidx);

        con2fb_map[unit] = newidx;
        if (!err && !found)
                err = con2fb_acquire_newinfo(vc, info, unit, oldidx);


        /*
         * If old fb is not mapped to any of the consoles,
         * fbcon should release it.
         */
        if (!err && oldinfo && !search_fb_in_map(oldidx))
                err = con2fb_release_oldinfo(vc, oldinfo, info, unit, oldidx,
                                             found);

        if (!err) {
                int show_logo = (fg_console == 0 && !user &&
                                 logo_shown != FBCON_LOGO_DONTSHOW);

                if (!found)
                        fbcon_add_cursor_timer(info);
                con2fb_map_boot[unit] = newidx;
                con2fb_init_display(vc, info, unit, show_logo);
        }

        if (!search_fb_in_map(info_idx))
                info_idx = newidx;

        return err;
}

/*
 *  Low Level Operations
 */
/* NOTE: fbcon cannot be __init: it may be called from do_take_over_console later */
static int var_to_display(struct display *disp,
                          struct fb_var_screeninfo *var,
                          struct fb_info *info)
{
        disp->xres_virtual = var->xres_virtual;
        disp->yres_virtual = var->yres_virtual;
        disp->bits_per_pixel = var->bits_per_pixel;
        disp->grayscale = var->grayscale;
        disp->nonstd = var->nonstd;
        disp->accel_flags = var->accel_flags;
        disp->height = var->height;
        disp->width = var->width;
        disp->red = var->red;
        disp->green = var->green;
        disp->blue = var->blue;
        disp->transp = var->transp;
        disp->rotate = var->rotate;
        disp->mode = fb_match_mode(var, &info->modelist);
        if (disp->mode == NULL)
                /* This should not happen */
                return -EINVAL;
        return 0;
}

static void display_to_var(struct fb_var_screeninfo *var,
                           struct display *disp)
{
        fb_videomode_to_var(var, disp->mode);
        var->xres_virtual = disp->xres_virtual;
        var->yres_virtual = disp->yres_virtual;
        var->bits_per_pixel = disp->bits_per_pixel;
        var->grayscale = disp->grayscale;
        var->nonstd = disp->nonstd;
        var->accel_flags = disp->accel_flags;
        var->height = disp->height;
        var->width = disp->width;
        var->red = disp->red;
        var->green = disp->green;
        var->blue = disp->blue;
        var->transp = disp->transp;
        var->rotate = disp->rotate;
}

static const char *fbcon_startup(void)
{
        const char *display_desc = "frame buffer device";
        struct display *p = &fb_display[fg_console];
        struct vc_data *vc = vc_cons[fg_console].d;
        const struct font_desc *font = NULL;
        struct module *owner;
        struct fb_info *info = NULL;
        struct fbcon_ops *ops;
        int rows, cols;

        /*
         *  If num_registered_fb is zero, this is a call for the dummy part.
         *  The frame buffer devices weren't initialized yet.
         */
        if (!num_registered_fb || info_idx == -1)
                return display_desc;
        /*
         * Instead of blindly using registered_fb[0], we use info_idx, set by
         * fb_console_init();
         */
        info = registered_fb[info_idx];
        if (!info)
                return NULL;
        
        owner = info->fbops->owner;
        if (!try_module_get(owner))
                return NULL;
        if (info->fbops->fb_open && info->fbops->fb_open(info, 0)) {
                module_put(owner);
                return NULL;
        }

        ops = kzalloc(sizeof(struct fbcon_ops), GFP_KERNEL);
        if (!ops) {
                module_put(owner);
                return NULL;
        }

        ops->currcon = -1;
        ops->graphics = 1;
        ops->cur_rotate = -1;
        info->fbcon_par = ops;
        p->con_rotate = initial_rotation;
        set_blitting_type(vc, info);

        if (info->fix.type != FB_TYPE_TEXT) {
                if (fbcon_softback_size) {
                        if (!softback_buf) {
                                softback_buf =
                                    (unsigned long)
                                    kmalloc(fbcon_softback_size,
                                            GFP_KERNEL);
                                if (!softback_buf) {
                                        fbcon_softback_size = 0;
                                        softback_top = 0;
                                }
                        }
                } else {
                        if (softback_buf) {
                                kfree((void *) softback_buf);
                                softback_buf = 0;
                                softback_top = 0;
                        }
                }
                if (softback_buf)
                        softback_in = softback_top = softback_curr =
                            softback_buf;
                softback_lines = 0;
        }

        /* Setup default font */
        if (!p->fontdata && !vc->vc_font.data) {
                if (!fontname[0] || !(font = find_font(fontname)))
                        font = get_default_font(info->var.xres,
                                                info->var.yres,
                                                info->pixmap.blit_x,
                                                info->pixmap.blit_y);
                vc->vc_font.width = font->width;
                vc->vc_font.height = font->height;
                vc->vc_font.data = (void *)(p->fontdata = font->data);

                vc->vc_font.charcount = 256; /* FIXME  Need to support more fonts */
        } else {
                p->fontdata = vc->vc_font.data;
        }

        cols = FBCON_SWAP(ops->rotate, info->var.xres, info->var.yres);
        rows = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
        cols /= vc->vc_font.width;
        rows /= vc->vc_font.height;
        vc_resize(vc, cols, rows);

        DPRINTK("mode:   %s\n", info->fix.id);
        DPRINTK("visual: %d\n", info->fix.visual);
        DPRINTK("res:    %dx%d-%d\n", info->var.xres,
                info->var.yres,
                info->var.bits_per_pixel);

        fbcon_add_cursor_timer(info);
        fbcon_has_exited = 0;
        return display_desc;
}

static void fbcon_init(struct vc_data *vc, int init)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops;
        struct vc_data **default_mode = vc->vc_display_fg;
        struct vc_data *svc = *default_mode;
        struct display *t, *p = &fb_display[vc->vc_num];
        int logo = 1, new_rows, new_cols, rows, cols, charcnt = 256;
        int cap, ret;

        if (info_idx == -1 || info == NULL)
            return;

        cap = info->flags;

        if (vc != svc || logo_shown == FBCON_LOGO_DONTSHOW ||
            (info->fix.type == FB_TYPE_TEXT))
                logo = 0;

        if (var_to_display(p, &info->var, info))
                return;

        if (!info->fbcon_par)
                con2fb_acquire_newinfo(vc, info, vc->vc_num, -1);

        /* If we are not the first console on this
           fb, copy the font from that console */
        t = &fb_display[fg_console];
        if (!p->fontdata) {
                if (t->fontdata) {
                        struct vc_data *fvc = vc_cons[fg_console].d;

                        vc->vc_font.data = (void *)(p->fontdata =
                                                    fvc->vc_font.data);
                        vc->vc_font.width = fvc->vc_font.width;
                        vc->vc_font.height = fvc->vc_font.height;
                        p->userfont = t->userfont;

                        if (p->userfont)
                                REFCOUNT(p->fontdata)++;
                } else {
                        const struct font_desc *font = NULL;

                        if (!fontname[0] || !(font = find_font(fontname)))
                                font = get_default_font(info->var.xres,
                                                        info->var.yres,
                                                        info->pixmap.blit_x,
                                                        info->pixmap.blit_y);
                        vc->vc_font.width = font->width;
                        vc->vc_font.height = font->height;
                        vc->vc_font.data = (void *)(p->fontdata = font->data);
                        vc->vc_font.charcount = 256; /* FIXME  Need to
                                                        support more fonts */
                }
        }

        if (p->userfont)
                charcnt = FNTCHARCNT(p->fontdata);

        vc->vc_panic_force_write = !!(info->flags & FBINFO_CAN_FORCE_OUTPUT);
        vc->vc_can_do_color = (fb_get_color_depth(&info->var, &info->fix)!=1);
        vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
        if (charcnt == 256) {
                vc->vc_hi_font_mask = 0;
        } else {
                vc->vc_hi_font_mask = 0x100;
                if (vc->vc_can_do_color)
                        vc->vc_complement_mask <<= 1;
        }

        if (!*svc->vc_uni_pagedir_loc)
                con_set_default_unimap(svc);
        if (!*vc->vc_uni_pagedir_loc)
                con_copy_unimap(vc, svc);

        ops = info->fbcon_par;
        p->con_rotate = initial_rotation;
        set_blitting_type(vc, info);

        cols = vc->vc_cols;
        rows = vc->vc_rows;
        new_cols = FBCON_SWAP(ops->rotate, info->var.xres, info->var.yres);
        new_rows = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
        new_cols /= vc->vc_font.width;
        new_rows /= vc->vc_font.height;

        /*
         * We must always set the mode. The mode of the previous console
         * driver could be in the same resolution but we are using different
         * hardware so we have to initialize the hardware.
         *
         * We need to do it in fbcon_init() to prevent screen corruption.
         */
        if (CON_IS_VISIBLE(vc) && vc->vc_mode == KD_TEXT) {
                if (info->fbops->fb_set_par &&
                    !(ops->flags & FBCON_FLAGS_INIT)) {
                        ret = info->fbops->fb_set_par(info);

                        if (ret)
                                printk(KERN_ERR "fbcon_init: detected "
                                        "unhandled fb_set_par error, "
                                        "error code %d\n", ret);
                }

                ops->flags |= FBCON_FLAGS_INIT;
        }

        ops->graphics = 0;

        if ((cap & FBINFO_HWACCEL_COPYAREA) &&
            !(cap & FBINFO_HWACCEL_DISABLED))
                p->scrollmode = SCROLL_MOVE;
        else /* default to something safe */
                p->scrollmode = SCROLL_REDRAW;

        /*
         *  ++guenther: console.c:vc_allocate() relies on initializing
         *  vc_{cols,rows}, but we must not set those if we are only
         *  resizing the console.
         */
        if (init) {
                vc->vc_cols = new_cols;
                vc->vc_rows = new_rows;
        } else
                vc_resize(vc, new_cols, new_rows);

        if (logo)
                fbcon_prepare_logo(vc, info, cols, rows, new_cols, new_rows);

        if (vc == svc && softback_buf)
                fbcon_update_softback(vc);

        if (ops->rotate_font && ops->rotate_font(info, vc)) {
                ops->rotate = FB_ROTATE_UR;
                set_blitting_type(vc, info);
        }

        ops->p = &fb_display[fg_console];
}

static void fbcon_free_font(struct display *p, bool freefont)
{
        if (freefont && p->userfont && p->fontdata && (--REFCOUNT(p->fontdata) == 0))
                kfree(p->fontdata - FONT_EXTRA_WORDS * sizeof(int));
        p->fontdata = NULL;
        p->userfont = 0;
}

static void fbcon_deinit(struct vc_data *vc)
{
        struct display *p = &fb_display[vc->vc_num];
        struct fb_info *info;
        struct fbcon_ops *ops;
        int idx;
        bool free_font = true;

        idx = con2fb_map[vc->vc_num];

        if (idx == -1)
                goto finished;

        info = registered_fb[idx];

        if (!info)
                goto finished;

        if (info->flags & FBINFO_MISC_FIRMWARE)
                free_font = false;
        ops = info->fbcon_par;

        if (!ops)
                goto finished;

        if (CON_IS_VISIBLE(vc))
                fbcon_del_cursor_timer(info);

        ops->flags &= ~FBCON_FLAGS_INIT;
finished:

        fbcon_free_font(p, free_font);
        if (free_font)
                vc->vc_font.data = NULL;

        if (!con_is_bound(&fb_con))
                fbcon_exit();

        return;
}

/* ====================================================================== */

/*  fbcon_XXX routines - interface used by the world
 *
 *  This system is now divided into two levels because of complications
 *  caused by hardware scrolling. Top level functions:
 *
 *      fbcon_bmove(), fbcon_clear(), fbcon_putc(), fbcon_clear_margins()
 *
 *  handles y values in range [0, scr_height-1] that correspond to real
 *  screen positions. y_wrap shift means that first line of bitmap may be
 *  anywhere on this display. These functions convert lineoffsets to
 *  bitmap offsets and deal with the wrap-around case by splitting blits.
 *
 *      fbcon_bmove_physical_8()    -- These functions fast implementations
 *      fbcon_clear_physical_8()    -- of original fbcon_XXX fns.
 *      fbcon_putc_physical_8()     -- (font width != 8) may be added later
 *
 *  WARNING:
 *
 *  At the moment fbcon_putc() cannot blit across vertical wrap boundary
 *  Implies should only really hardware scroll in rows. Only reason for
 *  restriction is simplicity & efficiency at the moment.
 */

static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height,
                        int width)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;

        struct display *p = &fb_display[vc->vc_num];
        u_int y_break;

        if (fbcon_is_inactive(vc, info))
                return;

        if (!height || !width)
                return;

        if (sy < vc->vc_top && vc->vc_top == logo_lines) {
                vc->vc_top = 0;
                /*
                 * If the font dimensions are not an integral of the display
                 * dimensions then the ops->clear below won't end up clearing
                 * the margins.  Call clear_margins here in case the logo
                 * bitmap stretched into the margin area.
                 */
                fbcon_clear_margins(vc, 0);
        }

        /* Split blits that cross physical y_wrap boundary */

        y_break = p->vrows - p->yscroll;
        if (sy < y_break && sy + height - 1 >= y_break) {
                u_int b = y_break - sy;
                ops->clear(vc, info, real_y(p, sy), sx, b, width);
                ops->clear(vc, info, real_y(p, sy + b), sx, height - b,
                                 width);
        } else
                ops->clear(vc, info, real_y(p, sy), sx, height, width);
}

static void fbcon_putcs(struct vc_data *vc, const unsigned short *s,
                        int count, int ypos, int xpos)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct display *p = &fb_display[vc->vc_num];
        struct fbcon_ops *ops = info->fbcon_par;

        if (!fbcon_is_inactive(vc, info))
                ops->putcs(vc, info, s, count, real_y(p, ypos), xpos,
                           get_color(vc, info, scr_readw(s), 1),
                           get_color(vc, info, scr_readw(s), 0));
}

static void fbcon_putc(struct vc_data *vc, int c, int ypos, int xpos)
{
        unsigned short chr;

        scr_writew(c, &chr);
        fbcon_putcs(vc, &chr, 1, ypos, xpos);
}

static void fbcon_clear_margins(struct vc_data *vc, int bottom_only)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;

        if (!fbcon_is_inactive(vc, info))
                ops->clear_margins(vc, info, bottom_only);
}

static void fbcon_cursor(struct vc_data *vc, int mode)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;
        int y;
        int c = scr_readw((u16 *) vc->vc_pos);

        if (fbcon_is_inactive(vc, info) || vc->vc_deccm != 1)
                return;

        if (vc->vc_cursor_type & 0x10)
                fbcon_del_cursor_timer(info);
        else
                fbcon_add_cursor_timer(info);

        ops->cursor_flash = (mode == CM_ERASE) ? 0 : 1;
        if (mode & CM_SOFTBACK) {
                mode &= ~CM_SOFTBACK;
                y = softback_lines;
        } else {
                if (softback_lines)
                        fbcon_set_origin(vc);
                y = 0;
        }

        ops->cursor(vc, info, mode, y, get_color(vc, info, c, 1),
                    get_color(vc, info, c, 0));
        vbl_cursor_cnt = CURSOR_DRAW_DELAY;
}

static int scrollback_phys_max = 0;
static int scrollback_max = 0;
static int scrollback_current = 0;

static void fbcon_set_disp(struct fb_info *info, struct fb_var_screeninfo *var,
                           int unit)
{
        struct display *p, *t;
        struct vc_data **default_mode, *vc;
        struct vc_data *svc;
        struct fbcon_ops *ops = info->fbcon_par;
        int rows, cols, charcnt = 256;

        p = &fb_display[unit];

        if (var_to_display(p, var, info))
                return;

        vc = vc_cons[unit].d;

        if (!vc)
                return;

        default_mode = vc->vc_display_fg;
        svc = *default_mode;
        t = &fb_display[svc->vc_num];

        if (!vc->vc_font.data) {
                vc->vc_font.data = (void *)(p->fontdata = t->fontdata);
                vc->vc_font.width = (*default_mode)->vc_font.width;
                vc->vc_font.height = (*default_mode)->vc_font.height;
                p->userfont = t->userfont;
                if (p->userfont)
                        REFCOUNT(p->fontdata)++;
        }
        if (p->userfont)
                charcnt = FNTCHARCNT(p->fontdata);

        var->activate = FB_ACTIVATE_NOW;
        info->var.activate = var->activate;
        var->yoffset = info->var.yoffset;
        var->xoffset = info->var.xoffset;
        fb_set_var(info, var);
        ops->var = info->var;
        vc->vc_can_do_color = (fb_get_color_depth(&info->var, &info->fix)!=1);
        vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
        if (charcnt == 256) {
                vc->vc_hi_font_mask = 0;
        } else {
                vc->vc_hi_font_mask = 0x100;
                if (vc->vc_can_do_color)
                        vc->vc_complement_mask <<= 1;
        }

        if (!*svc->vc_uni_pagedir_loc)
                con_set_default_unimap(svc);
        if (!*vc->vc_uni_pagedir_loc)
                con_copy_unimap(vc, svc);

        cols = FBCON_SWAP(ops->rotate, info->var.xres, info->var.yres);
        rows = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
        cols /= vc->vc_font.width;
        rows /= vc->vc_font.height;
        vc_resize(vc, cols, rows);

        if (CON_IS_VISIBLE(vc)) {
                update_screen(vc);
                if (softback_buf)
                        fbcon_update_softback(vc);
        }
}

static __inline__ void ywrap_up(struct vc_data *vc, int count)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;
        struct display *p = &fb_display[vc->vc_num];
        
        p->yscroll += count;
        if (p->yscroll >= p->vrows)     /* Deal with wrap */
                p->yscroll -= p->vrows;
        ops->var.xoffset = 0;
        ops->var.yoffset = p->yscroll * vc->vc_font.height;
        ops->var.vmode |= FB_VMODE_YWRAP;
        ops->update_start(info);
        scrollback_max += count;
        if (scrollback_max > scrollback_phys_max)
                scrollback_max = scrollback_phys_max;
        scrollback_current = 0;
}

static __inline__ void ywrap_down(struct vc_data *vc, int count)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;
        struct display *p = &fb_display[vc->vc_num];
        
        p->yscroll -= count;
        if (p->yscroll < 0)     /* Deal with wrap */
                p->yscroll += p->vrows;
        ops->var.xoffset = 0;
        ops->var.yoffset = p->yscroll * vc->vc_font.height;
        ops->var.vmode |= FB_VMODE_YWRAP;
        ops->update_start(info);
        scrollback_max -= count;
        if (scrollback_max < 0)
                scrollback_max = 0;
        scrollback_current = 0;
}

static __inline__ void ypan_up(struct vc_data *vc, int count)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct display *p = &fb_display[vc->vc_num];
        struct fbcon_ops *ops = info->fbcon_par;

        p->yscroll += count;
        if (p->yscroll > p->vrows - vc->vc_rows) {
                ops->bmove(vc, info, p->vrows - vc->vc_rows,
                            0, 0, 0, vc->vc_rows, vc->vc_cols);
                p->yscroll -= p->vrows - vc->vc_rows;
        }

        ops->var.xoffset = 0;
        ops->var.yoffset = p->yscroll * vc->vc_font.height;
        ops->var.vmode &= ~FB_VMODE_YWRAP;
        ops->update_start(info);
        fbcon_clear_margins(vc, 1);
        scrollback_max += count;
        if (scrollback_max > scrollback_phys_max)
                scrollback_max = scrollback_phys_max;
        scrollback_current = 0;
}

static __inline__ void ypan_up_redraw(struct vc_data *vc, int t, int count)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;
        struct display *p = &fb_display[vc->vc_num];

        p->yscroll += count;

        if (p->yscroll > p->vrows - vc->vc_rows) {
                p->yscroll -= p->vrows - vc->vc_rows;
                fbcon_redraw_move(vc, p, t + count, vc->vc_rows - count, t);
        }

        ops->var.xoffset = 0;
        ops->var.yoffset = p->yscroll * vc->vc_font.height;
        ops->var.vmode &= ~FB_VMODE_YWRAP;
        ops->update_start(info);
        fbcon_clear_margins(vc, 1);
        scrollback_max += count;
        if (scrollback_max > scrollback_phys_max)
                scrollback_max = scrollback_phys_max;
        scrollback_current = 0;
}

static __inline__ void ypan_down(struct vc_data *vc, int count)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct display *p = &fb_display[vc->vc_num];
        struct fbcon_ops *ops = info->fbcon_par;
        
        p->yscroll -= count;
        if (p->yscroll < 0) {
                ops->bmove(vc, info, 0, 0, p->vrows - vc->vc_rows,
                            0, vc->vc_rows, vc->vc_cols);
                p->yscroll += p->vrows - vc->vc_rows;
        }

        ops->var.xoffset = 0;
        ops->var.yoffset = p->yscroll * vc->vc_font.height;
        ops->var.vmode &= ~FB_VMODE_YWRAP;
        ops->update_start(info);
        fbcon_clear_margins(vc, 1);
        scrollback_max -= count;
        if (scrollback_max < 0)
                scrollback_max = 0;
        scrollback_current = 0;
}

static __inline__ void ypan_down_redraw(struct vc_data *vc, int t, int count)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;
        struct display *p = &fb_display[vc->vc_num];

        p->yscroll -= count;

        if (p->yscroll < 0) {
                p->yscroll += p->vrows - vc->vc_rows;
                fbcon_redraw_move(vc, p, t, vc->vc_rows - count, t + count);
        }

        ops->var.xoffset = 0;
        ops->var.yoffset = p->yscroll * vc->vc_font.height;
        ops->var.vmode &= ~FB_VMODE_YWRAP;
        ops->update_start(info);
        fbcon_clear_margins(vc, 1);
        scrollback_max -= count;
        if (scrollback_max < 0)
                scrollback_max = 0;
        scrollback_current = 0;
}

static void fbcon_redraw_softback(struct vc_data *vc, struct display *p,
                                  long delta)
{
        int count = vc->vc_rows;
        unsigned short *d, *s;
        unsigned long n;
        int line = 0;

        d = (u16 *) softback_curr;
        if (d == (u16 *) softback_in)
                d = (u16 *) vc->vc_origin;
        n = softback_curr + delta * vc->vc_size_row;
        softback_lines -= delta;
        if (delta < 0) {
                if (softback_curr < softback_top && n < softback_buf) {
                        n += softback_end - softback_buf;
                        if (n < softback_top) {
                                softback_lines -=
                                    (softback_top - n) / vc->vc_size_row;
                                n = softback_top;
                        }
                } else if (softback_curr >= softback_top
                           && n < softback_top) {
                        softback_lines -=
                            (softback_top - n) / vc->vc_size_row;
                        n = softback_top;
                }
        } else {
                if (softback_curr > softback_in && n >= softback_end) {
                        n += softback_buf - softback_end;
                        if (n > softback_in) {
                                n = softback_in;
                                softback_lines = 0;
                        }
                } else if (softback_curr <= softback_in && n > softback_in) {
                        n = softback_in;
                        softback_lines = 0;
                }
        }
        if (n == softback_curr)
                return;
        softback_curr = n;
        s = (u16 *) softback_curr;
        if (s == (u16 *) softback_in)
                s = (u16 *) vc->vc_origin;
        while (count--) {
                unsigned short *start;
                unsigned short *le;
                unsigned short c;
                int x = 0;
                unsigned short attr = 1;

                start = s;
                le = advance_row(s, 1);
                do {
                        c = scr_readw(s);
                        if (attr != (c & 0xff00)) {
                                attr = c & 0xff00;
                                if (s > start) {
                                        fbcon_putcs(vc, start, s - start,
                                                    line, x);
                                        x += s - start;
                                        start = s;
                                }
                        }
                        if (c == scr_readw(d)) {
                                if (s > start) {
                                        fbcon_putcs(vc, start, s - start,
                                                    line, x);
                                        x += s - start + 1;
                                        start = s + 1;
                                } else {
                                        x++;
                                        start++;
                                }
                        }
                        s++;
                        d++;
                } while (s < le);
                if (s > start)
                        fbcon_putcs(vc, start, s - start, line, x);
                line++;
                if (d == (u16 *) softback_end)
                        d = (u16 *) softback_buf;
                if (d == (u16 *) softback_in)
                        d = (u16 *) vc->vc_origin;
                if (s == (u16 *) softback_end)
                        s = (u16 *) softback_buf;
                if (s == (u16 *) softback_in)
                        s = (u16 *) vc->vc_origin;
        }
}

static void fbcon_redraw_move(struct vc_data *vc, struct display *p,
                              int line, int count, int dy)
{
        unsigned short *s = (unsigned short *)
                (vc->vc_origin + vc->vc_size_row * line);

        while (count--) {
                unsigned short *start = s;
                unsigned short *le = advance_row(s, 1);
                unsigned short c;
                int x = 0;
                unsigned short attr = 1;

                do {
                        c = scr_readw(s);
                        if (attr != (c & 0xff00)) {
                                attr = c & 0xff00;
                                if (s > start) {
                                        fbcon_putcs(vc, start, s - start,
                                                    dy, x);
                                        x += s - start;
                                        start = s;
                                }
                        }
                        console_conditional_schedule();
                        s++;
                } while (s < le);
                if (s > start)
                        fbcon_putcs(vc, start, s - start, dy, x);
                console_conditional_schedule();
                dy++;
        }
}

static void fbcon_redraw_blit(struct vc_data *vc, struct fb_info *info,
                        struct display *p, int line, int count, int ycount)
{
        int offset = ycount * vc->vc_cols;
        unsigned short *d = (unsigned short *)
            (vc->vc_origin + vc->vc_size_row * line);
        unsigned short *s = d + offset;
        struct fbcon_ops *ops = info->fbcon_par;

        while (count--) {
                unsigned short *start = s;
                unsigned short *le = advance_row(s, 1);
                unsigned short c;
                int x = 0;

                do {
                        c = scr_readw(s);

                        if (c == scr_readw(d)) {
                                if (s > start) {
                                        ops->bmove(vc, info, line + ycount, x,
                                                   line, x, 1, s-start);
                                        x += s - start + 1;
                                        start = s + 1;
                                } else {
                                        x++;
                                        start++;
                                }
                        }

                        scr_writew(c, d);
                        console_conditional_schedule();
                        s++;
                        d++;
                } while (s < le);
                if (s > start)
                        ops->bmove(vc, info, line + ycount, x, line, x, 1,
                                   s-start);
                console_conditional_schedule();
                if (ycount > 0)
                        line++;
                else {
                        line--;
                        /* NOTE: We subtract two lines from these pointers */
                        s -= vc->vc_size_row;
                        d -= vc->vc_size_row;
                }
        }
}

static void fbcon_redraw(struct vc_data *vc, struct display *p,
                         int line, int count, int offset)
{
        unsigned short *d = (unsigned short *)
            (vc->vc_origin + vc->vc_size_row * line);
        unsigned short *s = d + offset;

        while (count--) {
                unsigned short *start = s;
                unsigned short *le = advance_row(s, 1);
                unsigned short c;
                int x = 0;
                unsigned short attr = 1;

                do {
                        c = scr_readw(s);
                        if (attr != (c & 0xff00)) {
                                attr = c & 0xff00;
                                if (s > start) {
                                        fbcon_putcs(vc, start, s - start,
                                                    line, x);
                                        x += s - start;
                                        start = s;
                                }
                        }
                        if (c == scr_readw(d)) {
                                if (s > start) {
                                        fbcon_putcs(vc, start, s - start,
                                                     line, x);
                                        x += s - start + 1;
                                        start = s + 1;
                                } else {
                                        x++;
                                        start++;
                                }
                        }
                        scr_writew(c, d);
                        console_conditional_schedule();
                        s++;
                        d++;
                } while (s < le);
                if (s > start)
                        fbcon_putcs(vc, start, s - start, line, x);
                console_conditional_schedule();
                if (offset > 0)
                        line++;
                else {
                        line--;
                        /* NOTE: We subtract two lines from these pointers */
                        s -= vc->vc_size_row;
                        d -= vc->vc_size_row;
                }
        }
}

static inline void fbcon_softback_note(struct vc_data *vc, int t,
                                       int count)
{
        unsigned short *p;

        if (vc->vc_num != fg_console)
                return;
        p = (unsigned short *) (vc->vc_origin + t * vc->vc_size_row);

        while (count) {
                scr_memcpyw((u16 *) softback_in, p, vc->vc_size_row);
                count--;
                p = advance_row(p, 1);
                softback_in += vc->vc_size_row;
                if (softback_in == softback_end)
                        softback_in = softback_buf;
                if (softback_in == softback_top) {
                        softback_top += vc->vc_size_row;
                        if (softback_top == softback_end)
                                softback_top = softback_buf;
                }
        }
        softback_curr = softback_in;
}

static int fbcon_scroll(struct vc_data *vc, int t, int b, int dir,
                        int count)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct display *p = &fb_display[vc->vc_num];
        int scroll_partial = info->flags & FBINFO_PARTIAL_PAN_OK;

        if (fbcon_is_inactive(vc, info))
                return -EINVAL;

        fbcon_cursor(vc, CM_ERASE);

        /*
         * ++Geert: Only use ywrap/ypan if the console is in text mode
         * ++Andrew: Only use ypan on hardware text mode when scrolling the
         *           whole screen (prevents flicker).
         */

        switch (dir) {
        case SM_UP:
                if (count > vc->vc_rows)        /* Maximum realistic size */
                        count = vc->vc_rows;
                if (softback_top)
                        fbcon_softback_note(vc, t, count);
                if (logo_shown >= 0)
                        goto redraw_up;
                switch (p->scrollmode) {
                case SCROLL_MOVE:
                        fbcon_redraw_blit(vc, info, p, t, b - t - count,
                                     count);
                        fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
                        scr_memsetw((unsigned short *) (vc->vc_origin +
                                                        vc->vc_size_row *
                                                        (b - count)),
                                    vc->vc_video_erase_char,
                                    vc->vc_size_row * count);
                        return 1;
                        break;

                case SCROLL_WRAP_MOVE:
                        if (b - t - count > 3 * vc->vc_rows >> 2) {
                                if (t > 0)
                                        fbcon_bmove(vc, 0, 0, count, 0, t,
                                                    vc->vc_cols);
                                ywrap_up(vc, count);
                                if (vc->vc_rows - b > 0)
                                        fbcon_bmove(vc, b - count, 0, b, 0,
                                                    vc->vc_rows - b,
                                                    vc->vc_cols);
                        } else if (info->flags & FBINFO_READS_FAST)
                                fbcon_bmove(vc, t + count, 0, t, 0,
                                            b - t - count, vc->vc_cols);
                        else
                                goto redraw_up;
                        fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
                        break;

                case SCROLL_PAN_REDRAW:
                        if ((p->yscroll + count <=
                             2 * (p->vrows - vc->vc_rows))
                            && ((!scroll_partial && (b - t == vc->vc_rows))
                                || (scroll_partial
                                    && (b - t - count >
                                        3 * vc->vc_rows >> 2)))) {
                                if (t > 0)
                                        fbcon_redraw_move(vc, p, 0, t, count);
                                ypan_up_redraw(vc, t, count);
                                if (vc->vc_rows - b > 0)
                                        fbcon_redraw_move(vc, p, b,
                                                          vc->vc_rows - b, b);
                        } else
                                fbcon_redraw_move(vc, p, t + count, b - t - count, t);
                        fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
                        break;

                case SCROLL_PAN_MOVE:
                        if ((p->yscroll + count <=
                             2 * (p->vrows - vc->vc_rows))
                            && ((!scroll_partial && (b - t == vc->vc_rows))
                                || (scroll_partial
                                    && (b - t - count >
                                        3 * vc->vc_rows >> 2)))) {
                                if (t > 0)
                                        fbcon_bmove(vc, 0, 0, count, 0, t,
                                                    vc->vc_cols);
                                ypan_up(vc, count);
                                if (vc->vc_rows - b > 0)
                                        fbcon_bmove(vc, b - count, 0, b, 0,
                                                    vc->vc_rows - b,
                                                    vc->vc_cols);
                        } else if (info->flags & FBINFO_READS_FAST)
                                fbcon_bmove(vc, t + count, 0, t, 0,
                                            b - t - count, vc->vc_cols);
                        else
                                goto redraw_up;
                        fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
                        break;

                case SCROLL_REDRAW:
                      redraw_up:
                        fbcon_redraw(vc, p, t, b - t - count,
                                     count * vc->vc_cols);
                        fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
                        scr_memsetw((unsigned short *) (vc->vc_origin +
                                                        vc->vc_size_row *
                                                        (b - count)),
                                    vc->vc_video_erase_char,
                                    vc->vc_size_row * count);
                        return 1;
                }
                break;

        case SM_DOWN:
                if (count > vc->vc_rows)        /* Maximum realistic size */
                        count = vc->vc_rows;
                if (logo_shown >= 0)
                        goto redraw_down;
                switch (p->scrollmode) {
                case SCROLL_MOVE:
                        fbcon_redraw_blit(vc, info, p, b - 1, b - t - count,
                                     -count);
                        fbcon_clear(vc, t, 0, count, vc->vc_cols);
                        scr_memsetw((unsigned short *) (vc->vc_origin +
                                                        vc->vc_size_row *
                                                        t),
                                    vc->vc_video_erase_char,
                                    vc->vc_size_row * count);
                        return 1;
                        break;

                case SCROLL_WRAP_MOVE:
                        if (b - t - count > 3 * vc->vc_rows >> 2) {
                                if (vc->vc_rows - b > 0)
                                        fbcon_bmove(vc, b, 0, b - count, 0,
                                                    vc->vc_rows - b,
                                                    vc->vc_cols);
                                ywrap_down(vc, count);
                                if (t > 0)
                                        fbcon_bmove(vc, count, 0, 0, 0, t,
                                                    vc->vc_cols);
                        } else if (info->flags & FBINFO_READS_FAST)
                                fbcon_bmove(vc, t, 0, t + count, 0,
                                            b - t - count, vc->vc_cols);
                        else
                                goto redraw_down;
                        fbcon_clear(vc, t, 0, count, vc->vc_cols);
                        break;

                case SCROLL_PAN_MOVE:
                        if ((count - p->yscroll <= p->vrows - vc->vc_rows)
                            && ((!scroll_partial && (b - t == vc->vc_rows))
                                || (scroll_partial
                                    && (b - t - count >
                                        3 * vc->vc_rows >> 2)))) {
                                if (vc->vc_rows - b > 0)
                                        fbcon_bmove(vc, b, 0, b - count, 0,
                                                    vc->vc_rows - b,
                                                    vc->vc_cols);
                                ypan_down(vc, count);
                                if (t > 0)
                                        fbcon_bmove(vc, count, 0, 0, 0, t,
                                                    vc->vc_cols);
                        } else if (info->flags & FBINFO_READS_FAST)
                                fbcon_bmove(vc, t, 0, t + count, 0,
                                            b - t - count, vc->vc_cols);
                        else
                                goto redraw_down;
                        fbcon_clear(vc, t, 0, count, vc->vc_cols);
                        break;

                case SCROLL_PAN_REDRAW:
                        if ((count - p->yscroll <= p->vrows - vc->vc_rows)
                            && ((!scroll_partial && (b - t == vc->vc_rows))
                                || (scroll_partial
                                    && (b - t - count >
                                        3 * vc->vc_rows >> 2)))) {
                                if (vc->vc_rows - b > 0)
                                        fbcon_redraw_move(vc, p, b, vc->vc_rows - b,
                                                          b - count);
                                ypan_down_redraw(vc, t, count);
                                if (t > 0)
                                        fbcon_redraw_move(vc, p, count, t, 0);
                        } else
                                fbcon_redraw_move(vc, p, t, b - t - count, t + count);
                        fbcon_clear(vc, t, 0, count, vc->vc_cols);
                        break;

                case SCROLL_REDRAW:
                      redraw_down:
                        fbcon_redraw(vc, p, b - 1, b - t - count,
                                     -count * vc->vc_cols);
                        fbcon_clear(vc, t, 0, count, vc->vc_cols);
                        scr_memsetw((unsigned short *) (vc->vc_origin +
                                                        vc->vc_size_row *
                                                        t),
                                    vc->vc_video_erase_char,
                                    vc->vc_size_row * count);
                        return 1;
                }
        }
        return 0;
}

static void fbcon_bmove(struct vc_data *vc, int sy, int sx, int dy, int dx,
                        int height, int width)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct display *p = &fb_display[vc->vc_num];
        
        if (fbcon_is_inactive(vc, info))
                return;

        if (!width || !height)
                return;

        /*  Split blits that cross physical y_wrap case.
         *  Pathological case involves 4 blits, better to use recursive
         *  code rather than unrolled case
         *
         *  Recursive invocations don't need to erase the cursor over and
         *  over again, so we use fbcon_bmove_rec()
         */
        fbcon_bmove_rec(vc, p, sy, sx, dy, dx, height, width,
                        p->vrows - p->yscroll);
}

static void fbcon_bmove_rec(struct vc_data *vc, struct display *p, int sy, int sx, 
                            int dy, int dx, int height, int width, u_int y_break)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;
        u_int b;

        if (sy < y_break && sy + height > y_break) {
                b = y_break - sy;
                if (dy < sy) {  /* Avoid trashing self */
                        fbcon_bmove_rec(vc, p, sy, sx, dy, dx, b, width,
                                        y_break);
                        fbcon_bmove_rec(vc, p, sy + b, sx, dy + b, dx,
                                        height - b, width, y_break);
                } else {
                        fbcon_bmove_rec(vc, p, sy + b, sx, dy + b, dx,
                                        height - b, width, y_break);
                        fbcon_bmove_rec(vc, p, sy, sx, dy, dx, b, width,
                                        y_break);
                }
                return;
        }

        if (dy < y_break && dy + height > y_break) {
                b = y_break - dy;
                if (dy < sy) {  /* Avoid trashing self */
                        fbcon_bmove_rec(vc, p, sy, sx, dy, dx, b, width,
                                        y_break);
                        fbcon_bmove_rec(vc, p, sy + b, sx, dy + b, dx,
                                        height - b, width, y_break);
                } else {
                        fbcon_bmove_rec(vc, p, sy + b, sx, dy + b, dx,
                                        height - b, width, y_break);
                        fbcon_bmove_rec(vc, p, sy, sx, dy, dx, b, width,
                                        y_break);
                }
                return;
        }
        ops->bmove(vc, info, real_y(p, sy), sx, real_y(p, dy), dx,
                   height, width);
}

static void updatescrollmode(struct display *p,
                                        struct fb_info *info,
                                        struct vc_data *vc)
{
        struct fbcon_ops *ops = info->fbcon_par;
        int fh = vc->vc_font.height;
        int cap = info->flags;
        u16 t = 0;
        int ypan = FBCON_SWAP(ops->rotate, info->fix.ypanstep,
                                  info->fix.xpanstep);
        int ywrap = FBCON_SWAP(ops->rotate, info->fix.ywrapstep, t);
        int yres = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
        int vyres = FBCON_SWAP(ops->rotate, info->var.yres_virtual,
                                   info->var.xres_virtual);
        int good_pan = (cap & FBINFO_HWACCEL_YPAN) &&
                divides(ypan, vc->vc_font.height) && vyres > yres;
        int good_wrap = (cap & FBINFO_HWACCEL_YWRAP) &&
                divides(ywrap, vc->vc_font.height) &&
                divides(vc->vc_font.height, vyres) &&
                divides(vc->vc_font.height, yres);
        int reading_fast = cap & FBINFO_READS_FAST;
        int fast_copyarea = (cap & FBINFO_HWACCEL_COPYAREA) &&
                !(cap & FBINFO_HWACCEL_DISABLED);
        int fast_imageblit = (cap & FBINFO_HWACCEL_IMAGEBLIT) &&
                !(cap & FBINFO_HWACCEL_DISABLED);

        p->vrows = vyres/fh;
        if (yres > (fh * (vc->vc_rows + 1)))
                p->vrows -= (yres - (fh * vc->vc_rows)) / fh;
        if ((yres % fh) && (vyres % fh < yres % fh))
                p->vrows--;

        if (good_wrap || good_pan) {
                if (reading_fast || fast_copyarea)
                        p->scrollmode = good_wrap ?
                                SCROLL_WRAP_MOVE : SCROLL_PAN_MOVE;
                else
                        p->scrollmode = good_wrap ? SCROLL_REDRAW :
                                SCROLL_PAN_REDRAW;
        } else {
                if (reading_fast || (fast_copyarea && !fast_imageblit))
                        p->scrollmode = SCROLL_MOVE;
                else
                        p->scrollmode = SCROLL_REDRAW;
        }
}

static int fbcon_resize(struct vc_data *vc, unsigned int width, 
                        unsigned int height, unsigned int user)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;
        struct display *p = &fb_display[vc->vc_num];
        struct fb_var_screeninfo var = info->var;
        int x_diff, y_diff, virt_w, virt_h, virt_fw, virt_fh;

        virt_w = FBCON_SWAP(ops->rotate, width, height);
        virt_h = FBCON_SWAP(ops->rotate, height, width);
        virt_fw = FBCON_SWAP(ops->rotate, vc->vc_font.width,
                                 vc->vc_font.height);
        virt_fh = FBCON_SWAP(ops->rotate, vc->vc_font.height,
                                 vc->vc_font.width);
        var.xres = virt_w * virt_fw;
        var.yres = virt_h * virt_fh;
        x_diff = info->var.xres - var.xres;
        y_diff = info->var.yres - var.yres;
        if (x_diff < 0 || x_diff > virt_fw ||
            y_diff < 0 || y_diff > virt_fh) {
                const struct fb_videomode *mode;

                DPRINTK("attempting resize %ix%i\n", var.xres, var.yres);
                mode = fb_find_best_mode(&var, &info->modelist);
                if (mode == NULL)
                        return -EINVAL;
                display_to_var(&var, p);
                fb_videomode_to_var(&var, mode);

                if (virt_w > var.xres/virt_fw || virt_h > var.yres/virt_fh)
                        return -EINVAL;

                DPRINTK("resize now %ix%i\n", var.xres, var.yres);
                if (CON_IS_VISIBLE(vc)) {
                        var.activate = FB_ACTIVATE_NOW |
                                FB_ACTIVATE_FORCE;
                        fb_set_var(info, &var);
                }
                var_to_display(p, &info->var, info);
                ops->var = info->var;
        }
        updatescrollmode(p, info, vc);
        return 0;
}

static int fbcon_switch(struct vc_data *vc)
{
        struct fb_info *info, *old_info = NULL;
        struct fbcon_ops *ops;
        struct display *p = &fb_display[vc->vc_num];
        struct fb_var_screeninfo var;
        int i, ret, prev_console, charcnt = 256;

        info = registered_fb[con2fb_map[vc->vc_num]];
        ops = info->fbcon_par;

        if (softback_top) {
                if (softback_lines)
                        fbcon_set_origin(vc);
                softback_top = softback_curr = softback_in = softback_buf;
                softback_lines = 0;
                fbcon_update_softback(vc);
        }

        if (logo_shown >= 0) {
                struct vc_data *conp2 = vc_cons[logo_shown].d;

                if (conp2->vc_top == logo_lines
                    && conp2->vc_bottom == conp2->vc_rows)
                        conp2->vc_top = 0;
                logo_shown = FBCON_LOGO_CANSHOW;
        }

        prev_console = ops->currcon;
        if (prev_console != -1)
                old_info = registered_fb[con2fb_map[prev_console]];
        /*
         * FIXME: If we have multiple fbdev's loaded, we need to
         * update all info->currcon.  Perhaps, we can place this
         * in a centralized structure, but this might break some
         * drivers.
         *
         * info->currcon = vc->vc_num;
         */
        for (i = 0; i < FB_MAX; i++) {
                if (registered_fb[i] != NULL && registered_fb[i]->fbcon_par) {
                        struct fbcon_ops *o = registered_fb[i]->fbcon_par;

                        o->currcon = vc->vc_num;
                }
        }
        memset(&var, 0, sizeof(struct fb_var_screeninfo));
        display_to_var(&var, p);
        var.activate = FB_ACTIVATE_NOW;

        /*
         * make sure we don't unnecessarily trip the memcmp()
         * in fb_set_var()
         */
        info->var.activate = var.activate;
        var.vmode |= info->var.vmode & ~FB_VMODE_MASK;
        fb_set_var(info, &var);
        ops->var = info->var;

        if (old_info != NULL && (old_info != info ||
                                 info->flags & FBINFO_MISC_ALWAYS_SETPAR)) {
                if (info->fbops->fb_set_par) {
                        ret = info->fbops->fb_set_par(info);

                        if (ret)
                                printk(KERN_ERR "fbcon_switch: detected "
                                        "unhandled fb_set_par error, "
                                        "error code %d\n", ret);
                }

                if (old_info != info)
                        fbcon_del_cursor_timer(old_info);
        }

        if (fbcon_is_inactive(vc, info) ||
            ops->blank_state != FB_BLANK_UNBLANK)
                fbcon_del_cursor_timer(info);
        else
                fbcon_add_cursor_timer(info);

        set_blitting_type(vc, info);
        ops->cursor_reset = 1;

        if (ops->rotate_font && ops->rotate_font(info, vc)) {
                ops->rotate = FB_ROTATE_UR;
                set_blitting_type(vc, info);
        }

        vc->vc_can_do_color = (fb_get_color_depth(&info->var, &info->fix)!=1);
        vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;

        if (p->userfont)
                charcnt = FNTCHARCNT(vc->vc_font.data);

        if (charcnt > 256)
                vc->vc_complement_mask <<= 1;

        updatescrollmode(p, info, vc);

        switch (p->scrollmode) {
        case SCROLL_WRAP_MOVE:
                scrollback_phys_max = p->vrows - vc->vc_rows;
                break;
        case SCROLL_PAN_MOVE:
        case SCROLL_PAN_REDRAW:
                scrollback_phys_max = p->vrows - 2 * vc->vc_rows;
                if (scrollback_phys_max < 0)
                        scrollback_phys_max = 0;
                break;
        default:
                scrollback_phys_max = 0;
                break;
        }

        scrollback_max = 0;
        scrollback_current = 0;

        if (!fbcon_is_inactive(vc, info)) {
            ops->var.xoffset = ops->var.yoffset = p->yscroll = 0;
            ops->update_start(info);
        }

        fbcon_set_palette(vc, color_table);     
        fbcon_clear_margins(vc, 0);

        if (logo_shown == FBCON_LOGO_DRAW) {

                logo_shown = fg_console;
                /* This is protected above by initmem_freed */
                fb_show_logo(info, ops->rotate);
                update_region(vc,
                              vc->vc_origin + vc->vc_size_row * vc->vc_top,
                              vc->vc_size_row * (vc->vc_bottom -
                                                 vc->vc_top) / 2);
                return 0;
        }
        return 1;
}

static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info,
                                int blank)
{
        struct fb_event event;

        if (blank) {
                unsigned short charmask = vc->vc_hi_font_mask ?
                        0x1ff : 0xff;
                unsigned short oldc;

                oldc = vc->vc_video_erase_char;
                vc->vc_video_erase_char &= charmask;
                fbcon_clear(vc, 0, 0, vc->vc_rows, vc->vc_cols);
                vc->vc_video_erase_char = oldc;
        }


        if (!lock_fb_info(info))
                return;
        event.info = info;
        event.data = &blank;
        fb_notifier_call_chain(FB_EVENT_CONBLANK, &event);
        unlock_fb_info(info);
}

static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;

        if (mode_switch) {
                struct fb_var_screeninfo var = info->var;

                ops->graphics = 1;

                if (!blank) {
                        var.activate = FB_ACTIVATE_NOW | FB_ACTIVATE_FORCE;
                        fb_set_var(info, &var);
                        ops->graphics = 0;
                        ops->var = info->var;
                }
        }

        if (!fbcon_is_inactive(vc, info)) {
                if (ops->blank_state != blank) {
                        ops->blank_state = blank;
                        fbcon_cursor(vc, blank ? CM_ERASE : CM_DRAW);
                        ops->cursor_flash = (!blank);

                        if (!(info->flags & FBINFO_MISC_USEREVENT))
                                if (fb_blank(info, blank))
                                        fbcon_generic_blank(vc, info, blank);
                }

                if (!blank)
                        update_screen(vc);
        }

        if (mode_switch || fbcon_is_inactive(vc, info) ||
            ops->blank_state != FB_BLANK_UNBLANK)
                fbcon_del_cursor_timer(info);
        else
                fbcon_add_cursor_timer(info);

        return 0;
}

static int fbcon_debug_enter(struct vc_data *vc)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;

        ops->save_graphics = ops->graphics;
        ops->graphics = 0;
        if (info->fbops->fb_debug_enter)
                info->fbops->fb_debug_enter(info);
        fbcon_set_palette(vc, color_table);
        return 0;
}

static int fbcon_debug_leave(struct vc_data *vc)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;

        ops->graphics = ops->save_graphics;
        if (info->fbops->fb_debug_leave)
                info->fbops->fb_debug_leave(info);
        return 0;
}

static int fbcon_get_font(struct vc_data *vc, struct console_font *font)
{
        u8 *fontdata = vc->vc_font.data;
        u8 *data = font->data;
        int i, j;

        font->width = vc->vc_font.width;
        font->height = vc->vc_font.height;
        font->charcount = vc->vc_hi_font_mask ? 512 : 256;
        if (!font->data)
                return 0;

        if (font->width <= 8) {
                j = vc->vc_font.height;
                for (i = 0; i < font->charcount; i++) {
                        memcpy(data, fontdata, j);
                        memset(data + j, 0, 32 - j);
                        data += 32;
                        fontdata += j;
                }
        } else if (font->width <= 16) {
                j = vc->vc_font.height * 2;
                for (i = 0; i < font->charcount; i++) {
                        memcpy(data, fontdata, j);
                        memset(data + j, 0, 64 - j);
                        data += 64;
                        fontdata += j;
                }
        } else if (font->width <= 24) {
                for (i = 0; i < font->charcount; i++) {
                        for (j = 0; j < vc->vc_font.height; j++) {
                                *data++ = fontdata[0];
                                *data++ = fontdata[1];
                                *data++ = fontdata[2];
                                fontdata += sizeof(u32);
                        }
                        memset(data, 0, 3 * (32 - j));
                        data += 3 * (32 - j);
                }
        } else {
                j = vc->vc_font.height * 4;
                for (i = 0; i < font->charcount; i++) {
                        memcpy(data, fontdata, j);
                        memset(data + j, 0, 128 - j);
                        data += 128;
                        fontdata += j;
                }
        }
        return 0;
}

static int fbcon_do_set_font(struct vc_data *vc, int w, int h,
                             const u8 * data, int userfont)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        struct fbcon_ops *ops = info->fbcon_par;
        struct display *p = &fb_display[vc->vc_num];
        int resize;
        int cnt;
        char *old_data = NULL;

        if (CON_IS_VISIBLE(vc) && softback_lines)
                fbcon_set_origin(vc);

        resize = (w != vc->vc_font.width) || (h != vc->vc_font.height);
        if (p->userfont)
                old_data = vc->vc_font.data;
        if (userfont)
                cnt = FNTCHARCNT(data);
        else
                cnt = 256;
        vc->vc_font.data = (void *)(p->fontdata = data);
        if ((p->userfont = userfont))
                REFCOUNT(data)++;
        vc->vc_font.width = w;
        vc->vc_font.height = h;
        if (vc->vc_hi_font_mask && cnt == 256) {
                vc->vc_hi_font_mask = 0;
                if (vc->vc_can_do_color) {
                        vc->vc_complement_mask >>= 1;
                        vc->vc_s_complement_mask >>= 1;
                }
                        
                /* ++Edmund: reorder the attribute bits */
                if (vc->vc_can_do_color) {
                        unsigned short *cp =
                            (unsigned short *) vc->vc_origin;
                        int count = vc->vc_screenbuf_size / 2;
                        unsigned short c;
                        for (; count > 0; count--, cp++) {
                                c = scr_readw(cp);
                                scr_writew(((c & 0xfe00) >> 1) |
                                           (c & 0xff), cp);
                        }
                        c = vc->vc_video_erase_char;
                        vc->vc_video_erase_char =
                            ((c & 0xfe00) >> 1) | (c & 0xff);
                        vc->vc_attr >>= 1;
                }
        } else if (!vc->vc_hi_font_mask && cnt == 512) {
                vc->vc_hi_font_mask = 0x100;
                if (vc->vc_can_do_color) {
                        vc->vc_complement_mask <<= 1;
                        vc->vc_s_complement_mask <<= 1;
                }
                        
                /* ++Edmund: reorder the attribute bits */
                {
                        unsigned short *cp =
                            (unsigned short *) vc->vc_origin;
                        int count = vc->vc_screenbuf_size / 2;
                        unsigned short c;
                        for (; count > 0; count--, cp++) {
                                unsigned short newc;
                                c = scr_readw(cp);
                                if (vc->vc_can_do_color)
                                        newc =
                                            ((c & 0xff00) << 1) | (c &
                                                                   0xff);
                                else
                                        newc = c & ~0x100;
                                scr_writew(newc, cp);
                        }
                        c = vc->vc_video_erase_char;
                        if (vc->vc_can_do_color) {
                                vc->vc_video_erase_char =
                                    ((c & 0xff00) << 1) | (c & 0xff);
                                vc->vc_attr <<= 1;
                        } else
                                vc->vc_video_erase_char = c & ~0x100;
                }

        }

        if (resize) {
                int cols, rows;

                cols = FBCON_SWAP(ops->rotate, info->var.xres, info->var.yres);
                rows = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
                cols /= w;
                rows /= h;
                vc_resize(vc, cols, rows);
                if (CON_IS_VISIBLE(vc) && softback_buf)
                        fbcon_update_softback(vc);
        } else if (CON_IS_VISIBLE(vc)
                   && vc->vc_mode == KD_TEXT) {
                fbcon_clear_margins(vc, 0);
                update_screen(vc);
        }

        if (old_data && (--REFCOUNT(old_data) == 0))
                kfree(old_data - FONT_EXTRA_WORDS * sizeof(int));
        return 0;
}

static int fbcon_copy_font(struct vc_data *vc, int con)
{
        struct display *od = &fb_display[con];
        struct console_font *f = &vc->vc_font;

        if (od->fontdata == f->data)
                return 0;       /* already the same font... */
        return fbcon_do_set_font(vc, f->width, f->height, od->fontdata, od->userfont);
}

/*
 *  User asked to set font; we are guaranteed that
 *      a) width and height are in range 1..32
 *      b) charcount does not exceed 512
 *  but lets not assume that, since someone might someday want to use larger
 *  fonts. And charcount of 512 is small for unicode support.
 *
 *  However, user space gives the font in 32 rows , regardless of
 *  actual font height. So a new API is needed if support for larger fonts
 *  is ever implemented.
 */

static int fbcon_set_font(struct vc_data *vc, struct console_font *font, unsigned flags)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        unsigned charcount = font->charcount;
        int w = font->width;
        int h = font->height;
        int size;
        int i, csum;
        u8 *new_data, *data = font->data;
        int pitch = (font->width+7) >> 3;

        /* Is there a reason why fbconsole couldn't handle any charcount >256?
         * If not this check should be changed to charcount < 256 */
        if (charcount != 256 && charcount != 512)
                return -EINVAL;

        /* Make sure drawing engine can handle the font */
        if (!(info->pixmap.blit_x & (1 << (font->width - 1))) ||
            !(info->pixmap.blit_y & (1 << (font->height - 1))))
                return -EINVAL;

        /* Make sure driver can handle the font length */
        if (fbcon_invalid_charcount(info, charcount))
                return -EINVAL;

        size = h * pitch * charcount;

        new_data = kmalloc(FONT_EXTRA_WORDS * sizeof(int) + size, GFP_USER);

        if (!new_data)
                return -ENOMEM;

        new_data += FONT_EXTRA_WORDS * sizeof(int);
        FNTSIZE(new_data) = size;
        FNTCHARCNT(new_data) = charcount;
        REFCOUNT(new_data) = 0; /* usage counter */
        for (i=0; i< charcount; i++) {
                memcpy(new_data + i*h*pitch, data +  i*32*pitch, h*pitch);
        }

        /* Since linux has a nice crc32 function use it for counting font
         * checksums. */
        csum = crc32(0, new_data, size);

        FNTSUM(new_data) = csum;
        /* Check if the same font is on some other console already */
        for (i = first_fb_vc; i <= last_fb_vc; i++) {
                struct vc_data *tmp = vc_cons[i].d;
                
                if (fb_display[i].userfont &&
                    fb_display[i].fontdata &&
                    FNTSUM(fb_display[i].fontdata) == csum &&
                    FNTSIZE(fb_display[i].fontdata) == size &&
                    tmp->vc_font.width == w &&
                    !memcmp(fb_display[i].fontdata, new_data, size)) {
                        kfree(new_data - FONT_EXTRA_WORDS * sizeof(int));
                        new_data = (u8 *)fb_display[i].fontdata;
                        break;
                }
        }
        return fbcon_do_set_font(vc, font->width, font->height, new_data, 1);
}

static int fbcon_set_def_font(struct vc_data *vc, struct console_font *font, char *name)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        const struct font_desc *f;

        if (!name)
                f = get_default_font(info->var.xres, info->var.yres,
                                     info->pixmap.blit_x, info->pixmap.blit_y);
        else if (!(f = find_font(name)))
                return -ENOENT;

        font->width = f->width;
        font->height = f->height;
        return fbcon_do_set_font(vc, f->width, f->height, f->data, 0);
}

static u16 palette_red[16];
static u16 palette_green[16];
static u16 palette_blue[16];

static struct fb_cmap palette_cmap = {
        0, 16, palette_red, palette_green, palette_blue, NULL
};

static int fbcon_set_palette(struct vc_data *vc, unsigned char *table)
{
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        int i, j, k, depth;
        u8 val;

        if (fbcon_is_inactive(vc, info))
                return -EINVAL;

        if (!CON_IS_VISIBLE(vc))
                return 0;

        depth = fb_get_color_depth(&info->var, &info->fix);
        if (depth > 3) {
                for (i = j = 0; i < 16; i++) {
                        k = table[i];
                        val = vc->vc_palette[j++];
                        palette_red[k] = (val << 8) | val;
                        val = vc->vc_palette[j++];
                        palette_green[k] = (val << 8) | val;
                        val = vc->vc_palette[j++];
                        palette_blue[k] = (val << 8) | val;
                }
                palette_cmap.len = 16;
                palette_cmap.start = 0;
        /*
         * If framebuffer is capable of less than 16 colors,
         * use default palette of fbcon.
         */
        } else
                fb_copy_cmap(fb_default_cmap(1 << depth), &palette_cmap);

        return fb_set_cmap(&palette_cmap, info);
}

static u16 *fbcon_screen_pos(struct vc_data *vc, int offset)
{
        unsigned long p;
        int line;
        
        if (vc->vc_num != fg_console || !softback_lines)
                return (u16 *) (vc->vc_origin + offset);
        line = offset / vc->vc_size_row;
        if (line >= softback_lines)
                return (u16 *) (vc->vc_origin + offset -
                                softback_lines * vc->vc_size_row);
        p = softback_curr + offset;
        if (p >= softback_end)
                p += softback_buf - softback_end;
        return (u16 *) p;
}

static unsigned long fbcon_getxy(struct vc_data *vc, unsigned long pos,
                                 int *px, int *py)
{
        unsigned long ret;
        int x, y;

        if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
                unsigned long offset = (pos - vc->vc_origin) / 2;

                x = offset % vc->vc_cols;
                y = offset / vc->vc_cols;
                if (vc->vc_num == fg_console)
                        y += softback_lines;
                ret = pos + (vc->vc_cols - x) * 2;
        } else if (vc->vc_num == fg_console && softback_lines) {
                unsigned long offset = pos - softback_curr;

                if (pos < softback_curr)
                        offset += softback_end - softback_buf;
                offset /= 2;
                x = offset % vc->vc_cols;
                y = offset / vc->vc_cols;
                ret = pos + (vc->vc_cols - x) * 2;
                if (ret == softback_end)
                        ret = softback_buf;
                if (ret == softback_in)
                        ret = vc->vc_origin;
        } else {
                /* Should not happen */
                x = y = 0;
                ret = vc->vc_origin;
        }
        if (px)
                *px = x;
        if (py)
                *py = y;
        return ret;
}

/* As we might be inside of softback, we may work with non-contiguous buffer,
   that's why we have to use a separate routine. */
static void fbcon_invert_region(struct vc_data *vc, u16 * p, int cnt)
{
        while (cnt--) {
                u16 a = scr_readw(p);
                if (!vc->vc_can_do_color)
                        a ^= 0x0800;
                else if (vc->vc_hi_font_mask == 0x100)
                        a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) |
                            (((a) & 0x0e00) << 4);
                else
                        a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) |
                            (((a) & 0x0700) << 4);
                scr_writew(a, p++);
                if (p == (u16 *) softback_end)
                        p = (u16 *) softback_buf;
                if (p == (u16 *) softback_in)
                        p = (u16 *) vc->vc_origin;
        }
}

static int fbcon_scrolldelta(struct vc_data *vc, int lines)
{
        struct fb_info *info = registered_fb[con2fb_map[fg_console]];
        struct fbcon_ops *ops = info->fbcon_par;
        struct display *disp = &fb_display[fg_console];
        int offset, limit, scrollback_old;

        if (softback_top) {
                if (vc->vc_num != fg_console)
                        return 0;
                if (vc->vc_mode != KD_TEXT || !lines)
                        return 0;
                if (logo_shown >= 0) {
                        struct vc_data *conp2 = vc_cons[logo_shown].d;

                        if (conp2->vc_top == logo_lines
                            && conp2->vc_bottom == conp2->vc_rows)
                                conp2->vc_top = 0;
                        if (logo_shown == vc->vc_num) {
                                unsigned long p, q;
                                int i;

                                p = softback_in;
                                q = vc->vc_origin +
                                    logo_lines * vc->vc_size_row;
                                for (i = 0; i < logo_lines; i++) {
                                        if (p == softback_top)
                                                break;
                                        if (p == softback_buf)
                                                p = softback_end;
                                        p -= vc->vc_size_row;
                                        q -= vc->vc_size_row;
                                        scr_memcpyw((u16 *) q, (u16 *) p,
                                                    vc->vc_size_row);
                                }
                                softback_in = softback_curr = p;
                                update_region(vc, vc->vc_origin,
                                              logo_lines * vc->vc_cols);
                        }
                        logo_shown = FBCON_LOGO_CANSHOW;
                }
                fbcon_cursor(vc, CM_ERASE | CM_SOFTBACK);
                fbcon_redraw_softback(vc, disp, lines);
                fbcon_cursor(vc, CM_DRAW | CM_SOFTBACK);
                return 0;
        }

        if (!scrollback_phys_max)
                return -ENOSYS;

        scrollback_old = scrollback_current;
        scrollback_current -= lines;
        if (scrollback_current < 0)
                scrollback_current = 0;
        else if (scrollback_current > scrollback_max)
                scrollback_current = scrollback_max;
        if (scrollback_current == scrollback_old)
                return 0;

        if (fbcon_is_inactive(vc, info))
                return 0;

        fbcon_cursor(vc, CM_ERASE);

        offset = disp->yscroll - scrollback_current;
        limit = disp->vrows;
        switch (disp->scrollmode) {
        case SCROLL_WRAP_MOVE:
                info->var.vmode |= FB_VMODE_YWRAP;
                break;
        case SCROLL_PAN_MOVE:
        case SCROLL_PAN_REDRAW:
                limit -= vc->vc_rows;
                info->var.vmode &= ~FB_VMODE_YWRAP;
                break;
        }
        if (offset < 0)
                offset += limit;
        else if (offset >= limit)
                offset -= limit;

        ops->var.xoffset = 0;
        ops->var.yoffset = offset * vc->vc_font.height;
        ops->update_start(info);

        if (!scrollback_current)
                fbcon_cursor(vc, CM_DRAW);
        return 0;
}

static int fbcon_set_origin(struct vc_data *vc)
{
        if (softback_lines)
                fbcon_scrolldelta(vc, softback_lines);
        return 0;
}

static void fbcon_suspended(struct fb_info *info)
{
        struct vc_data *vc = NULL;
        struct fbcon_ops *ops = info->fbcon_par;

        if (!ops || ops->currcon < 0)
                return;
        vc = vc_cons[ops->currcon].d;

        /* Clear cursor, restore saved data */
        fbcon_cursor(vc, CM_ERASE);
}

static void fbcon_resumed(struct fb_info *info)
{
        struct vc_data *vc;
        struct fbcon_ops *ops = info->fbcon_par;

        if (!ops || ops->currcon < 0)
                return;
        vc = vc_cons[ops->currcon].d;

        update_screen(vc);
}

static void fbcon_modechanged(struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;
        struct vc_data *vc;
        struct display *p;
        int rows, cols;

        if (!ops || ops->currcon < 0)
                return;
        vc = vc_cons[ops->currcon].d;
        if (vc->vc_mode != KD_TEXT ||
            registered_fb[con2fb_map[ops->currcon]] != info)
                return;

        p = &fb_display[vc->vc_num];
        set_blitting_type(vc, info);

        if (CON_IS_VISIBLE(vc)) {
                var_to_display(p, &info->var, info);
                cols = FBCON_SWAP(ops->rotate, info->var.xres, info->var.yres);
                rows = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
                cols /= vc->vc_font.width;
                rows /= vc->vc_font.height;
                vc_resize(vc, cols, rows);
                updatescrollmode(p, info, vc);
                scrollback_max = 0;
                scrollback_current = 0;

                if (!fbcon_is_inactive(vc, info)) {
                    ops->var.xoffset = ops->var.yoffset = p->yscroll = 0;
                    ops->update_start(info);
                }

                fbcon_set_palette(vc, color_table);
                update_screen(vc);
                if (softback_buf)
                        fbcon_update_softback(vc);
        }
}

static void fbcon_set_all_vcs(struct fb_info *info)
{
        struct fbcon_ops *ops = info->fbcon_par;
        struct vc_data *vc;
        struct display *p;
        int i, rows, cols, fg = -1;

        if (!ops || ops->currcon < 0)
                return;

        for (i = first_fb_vc; i <= last_fb_vc; i++) {
                vc = vc_cons[i].d;
                if (!vc || vc->vc_mode != KD_TEXT ||
                    registered_fb[con2fb_map[i]] != info)
                        continue;

                if (CON_IS_VISIBLE(vc)) {
                        fg = i;
                        continue;
                }

                p = &fb_display[vc->vc_num];
                set_blitting_type(vc, info);
                var_to_display(p, &info->var, info);
                cols = FBCON_SWAP(ops->rotate, info->var.xres, info->var.yres);
                rows = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
                cols /= vc->vc_font.width;
                rows /= vc->vc_font.height;
                vc_resize(vc, cols, rows);
        }

        if (fg != -1)
                fbcon_modechanged(info);
}

static int fbcon_mode_deleted(struct fb_info *info,
                              struct fb_videomode *mode)
{
        struct fb_info *fb_info;
        struct display *p;
        int i, j, found = 0;

        /* before deletion, ensure that mode is not in use */
        for (i = first_fb_vc; i <= last_fb_vc; i++) {
                j = con2fb_map[i];
                if (j == -1)
                        continue;
                fb_info = registered_fb[j];
                if (fb_info != info)
                        continue;
                p = &fb_display[i];
                if (!p || !p->mode)
                        continue;
                if (fb_mode_is_equal(p->mode, mode)) {
                        found = 1;
                        break;
                }
        }
        return found;
}

#ifdef CONFIG_VT_HW_CONSOLE_BINDING
static int fbcon_unbind(void)
{
        int ret;

        ret = do_unbind_con_driver(&fb_con, first_fb_vc, last_fb_vc,
                                fbcon_is_default);

        if (!ret)
                fbcon_has_console_bind = 0;