fbcon.c

Linux程序设计权威指南代码.包含所有章节代码

    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) / conp->vc_size_row;
		n = softback_top;
	    }
        } else if (softback_curr >= softback_top && n < softback_top) {
	    softback_lines -= (softback_top - n) / conp->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 *)conp->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) {
		    p->dispsw->putcs(conp, p, start, s - start,
				     real_y(p, line), x);
		    x += s - start;
		    start = s;
		}
	    }
	    if (c == scr_readw(d)) {
	    	if (s > start) {
	    	    p->dispsw->putcs(conp, p, start, s - start,
				     real_y(p, line), x);
		    x += s - start + 1;
		    start = s + 1;
	    	} else {
	    	    x++;
	    	    start++;
	    	}
	    }
	    s++;
	    d++;
	} while (s < le);
	if (s > start)
	    p->dispsw->putcs(conp, p, start, s - start, real_y(p, line), x);
	line++;
	if (d == (u16 *)softback_end)
	    d = (u16 *)softback_buf;
	if (d == (u16 *)softback_in)
	    d = (u16 *)conp->vc_origin;
	if (s == (u16 *)softback_end)
	    s = (u16 *)softback_buf;
	if (s == (u16 *)softback_in)
	    s = (u16 *)conp->vc_origin;
    }
}

static void fbcon_redraw(struct vc_data *conp, struct display *p, 
			 int line, int count, int offset)
{
    unsigned short *d = (unsigned short *)
	(conp->vc_origin + conp->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) {
		    p->dispsw->putcs(conp, p, start, s - start,
				     real_y(p, line), x);
		    x += s - start;
		    start = s;
		}
	    }
	    if (c == scr_readw(d)) {
	    	if (s > start) {
	    	    p->dispsw->putcs(conp, p, start, s - start,
				     real_y(p, line), x);
		    x += s - start + 1;
		    start = s + 1;
	    	} else {
	    	    x++;
	    	    start++;
	    	}
	    }
	    scr_writew(c, d);
	    s++;
	    d++;
	} while (s < le);
	if (s > start)
	    p->dispsw->putcs(conp, p, start, s - start, real_y(p, line), x);
	if (offset > 0)
		line++;
	else {
		line--;
		/* NOTE: We subtract two lines from these pointers */
		s -= conp->vc_size_row;
		d -= conp->vc_size_row;
	}
    }
}

/* This cannot be used together with ypan or ywrap */
void fbcon_redraw_bmove(struct display *p, int sy, int sx, int dy, int dx, int h, int w)
{
    if (sy != dy)
    	panic("fbcon_redraw_bmove width sy != dy");
    /* h will be always 1, but it does not matter if we are more generic */

    while (h-- > 0) {
	struct vc_data *conp = p->conp;
	unsigned short *d = (unsigned short *)
		(conp->vc_origin + conp->vc_size_row * dy + dx * 2);
	unsigned short *s = d + (dx - sx);
	unsigned short *start = d;
	unsigned short *ls = d;
	unsigned short *le = d + w;
	unsigned short c;
	int x = dx;
	unsigned short attr = 1;

	do {
	    c = scr_readw(d);
	    if (attr != (c & 0xff00)) {
		attr = c & 0xff00;
		if (d > start) {
		    p->dispsw->putcs(conp, p, start, d - start, dy, x);
		    x += d - start;
		    start = d;
		}
	    }
	    if (s >= ls && s < le && c == scr_readw(s)) {
		if (d > start) {
		    p->dispsw->putcs(conp, p, start, d - start, dy, x);
		    x += d - start + 1;
		    start = d + 1;
		} else {
		    x++;
		    start++;
		}
	    }
	    s++;
	    d++;
	} while (d < le);
	if (d > start)
	    p->dispsw->putcs(conp, p, start, d - start, dy, x);
	sy++;
	dy++;
    }
}

static inline void fbcon_softback_note(struct vc_data *conp, int t, int count)
{
    unsigned short *p = (unsigned short *)
    	(conp->vc_origin + t * conp->vc_size_row);
    while (count) {
    	scr_memcpyw((u16 *)softback_in, p, conp->vc_size_row);
    	count--;
    	p = advance_row(p, 1);
    	softback_in += conp->vc_size_row;
    	if (softback_in == softback_end)
    	    softback_in = softback_buf;
    	if (softback_in == softback_top) {
    	    softback_top += conp->vc_size_row;
    	    if (softback_top == softback_end)
    	    	softback_top = softback_buf;
    	}
    }
    softback_curr = softback_in;
}

static int fbcon_scroll(struct vc_data *conp, int t, int b, int dir,
			int count)
{
    int unit = conp->vc_num;
    struct display *p = &fb_display[unit];
    int scroll_partial = !(p->scrollmode & __SCROLL_YNOPARTIAL);

    if (!p->can_soft_blank && console_blanked)
	return 0;

    if (!count || vt_cons[unit]->vc_mode != KD_TEXT)
	return 0;

    fbcon_cursor(conp, 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 > conp->vc_rows)	/* Maximum realistic size */
		count = conp->vc_rows;
	    if (softback_top)
	        fbcon_softback_note(conp, t, count);
	    if (logo_shown >= 0) goto redraw_up;
	    switch (p->scrollmode & __SCROLL_YMASK) {
	    case __SCROLL_YMOVE:
		p->dispsw->bmove(p, t+count, 0, t, 0, b-t-count,
				 conp->vc_cols);
		p->dispsw->clear(conp, p, b-count, 0, count,
				 conp->vc_cols);
		break;

	    case __SCROLL_YWRAP:
		if (b-t-count > 3*conp->vc_rows>>2) {
		    if (t > 0)
			fbcon_bmove(conp, 0, 0, count, 0, t,
				    conp->vc_cols);
			ywrap_up(unit, conp, p, count);
		    if (conp->vc_rows-b > 0)
			fbcon_bmove(conp, b-count, 0, b, 0,
				    conp->vc_rows-b, conp->vc_cols);
		} else if (p->scrollmode & __SCROLL_YPANREDRAW)
		    goto redraw_up;
		else
		    fbcon_bmove(conp, t+count, 0, t, 0, b-t-count,
				conp->vc_cols);
		fbcon_clear(conp, b-count, 0, count, conp->vc_cols);
		break;

	    case __SCROLL_YPAN:
		if (( p->yscroll + count <= 2 * (p->vrows - conp->vc_rows)) &&
		    (( !scroll_partial && (b-t == conp->vc_rows)) ||
		     ( scroll_partial  && (b-t-count > 3*conp->vc_rows>>2)))) {
		    if (t > 0)
			fbcon_bmove(conp, 0, 0, count, 0, t,
				    conp->vc_cols);
		    ypan_up(unit, conp, p, count);
		    if (conp->vc_rows-b > 0)
			fbcon_bmove(conp, b-count, 0, b, 0,
				    conp->vc_rows-b, conp->vc_cols);
		} else if (p->scrollmode & __SCROLL_YPANREDRAW)
		    goto redraw_up;
		else
		    fbcon_bmove(conp, t+count, 0, t, 0, b-t-count,
				conp->vc_cols);
		fbcon_clear(conp, b-count, 0, count, conp->vc_cols);
		break;

	    case __SCROLL_YREDRAW:
	    redraw_up:
		fbcon_redraw(conp, p, t, b-t-count, count*conp->vc_cols);
		p->dispsw->clear(conp, p, real_y(p, b-count), 0,
				 count, conp->vc_cols);
		scr_memsetw((unsigned short *)(conp->vc_origin + 
		    	    conp->vc_size_row * (b-count)), 
		    	    conp->vc_video_erase_char,
		    	    conp->vc_size_row * count);
		return 1;
	    }
	    break;

	case SM_DOWN:
	    if (count > conp->vc_rows)	/* Maximum realistic size */
		count = conp->vc_rows;
	    switch (p->scrollmode & __SCROLL_YMASK) {
	    case __SCROLL_YMOVE:
		p->dispsw->bmove(p, t, 0, t+count, 0, b-t-count,
				 conp->vc_cols);
		p->dispsw->clear(conp, p, t, 0,
				 count, conp->vc_cols);
		break;

	    case __SCROLL_YWRAP:
		if (b-t-count > 3*conp->vc_rows>>2) {
		    if (conp->vc_rows-b > 0)
			fbcon_bmove(conp, b, 0, b-count, 0,
				    conp->vc_rows-b, conp->vc_cols);
		    ywrap_down(unit, conp, p, count);
		    if (t > 0)
			fbcon_bmove(conp, count, 0, 0, 0, t,
				    conp->vc_cols);
		} else if (p->scrollmode & __SCROLL_YPANREDRAW)
		    goto redraw_down;
		else
		    fbcon_bmove(conp, t, 0, t+count, 0, b-t-count,
				conp->vc_cols);
		fbcon_clear(conp, t, 0, count, conp->vc_cols);
		break;

	    case __SCROLL_YPAN:
		if (( count-p->yscroll <= p->vrows-conp->vc_rows) &&
		    (( !scroll_partial && (b-t == conp->vc_rows)) ||
		     ( scroll_partial  && (b-t-count > 3*conp->vc_rows>>2)))) {
		    if (conp->vc_rows-b > 0)
			fbcon_bmove(conp, b, 0, b-count, 0,
				    conp->vc_rows-b, conp->vc_cols);
		    ypan_down(unit, conp, p, count);
		    if (t > 0)
			fbcon_bmove(conp, count, 0, 0, 0, t,
				    conp->vc_cols);
		} else if (p->scrollmode & __SCROLL_YPANREDRAW)
		    goto redraw_down;
		else
		    fbcon_bmove(conp, t, 0, t+count, 0, b-t-count,
				conp->vc_cols);
		fbcon_clear(conp, t, 0, count, conp->vc_cols);
		break;

	    case __SCROLL_YREDRAW:
	    redraw_down:
		fbcon_redraw(conp, p, b - 1, b-t-count, -count*conp->vc_cols);
		p->dispsw->clear(conp, p, real_y(p, t), 0,
				 count, conp->vc_cols);
	    	scr_memsetw((unsigned short *)(conp->vc_origin + 
	    		    conp->vc_size_row * t), 
	    		    conp->vc_video_erase_char,
	    		    conp->vc_size_row * count);
	    	return 1;
	    }
    }
    return 0;
}


static void fbcon_bmove(struct vc_data *conp, int sy, int sx, int dy, int dx,
			int height, int width)
{
    int unit = conp->vc_num;
    struct display *p = &fb_display[unit];
    
    if (!p->can_soft_blank && console_blanked)
	return;

    if (!width || !height)
	return;

    if (((sy <= p->cursor_y) && (p->cursor_y < sy+height) &&
	  (sx <= p->cursor_x) && (p->cursor_x < sx+width)) ||
	 ((dy <= p->cursor_y) && (p->cursor_y < dy+height) &&
	  (dx <= p->cursor_x) && (p->cursor_x < dx+width)))
	fbcon_cursor(conp, CM_ERASE|CM_SOFTBACK);

    /*  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(p, sy, sx, dy, dx, height, width, p->vrows-p->yscroll);
}

static void fbcon_bmove_rec(struct display *p, int sy, int sx, int dy, int dx,
			    int height, int width, u_int y_break)
{
    u_int b;

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


static int fbcon_switch(struct vc_data *conp)
{
    int unit = conp->vc_num;
    struct display *p = &fb_display[unit];
    struct fb_info *info = p->fb_info;

    if (softback_top) {
    	int l = fbcon_softback_size / conp->vc_size_row;
	if (softback_lines)
	    fbcon_set_origin(conp);
        softback_top = softback_curr = softback_in = softback_buf;
        softback_lines = 0;

	if (l > 5)
	    softback_end = softback_buf + l * conp->vc_size_row;
	else {
	    /* Smaller scrollback makes no sense, and 0 would screw
	       the operation totally */
	    softback_top = 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;
    	logo_shown = -1;
    }
    p->var.yoffset = p->yscroll = 0;
    switch (p->scrollmode & __SCROLL_YMASK) {
	case __SCROLL_YWRAP:
	    scrollback_phys_max = p->vrows-conp->vc_rows;
	    break;
	case __SCROLL_YPAN:
	    scrollback_phys_max = p->vrows-2*conp->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 (info && info->switch_con)
	(*info->switch_con)(unit, info);
    if (p->dispsw->clear_margins && vt_cons[unit]->vc_mode == KD_TEXT)
	p->dispsw->clear_margins(conp, p, 0);
    if (logo_shown == -2) {
	logo_shown = fg_console;
	fbcon_show_logo(); /* This is protected above by initmem_freed */
	update_region(fg_console,
		      conp->vc_origin + conp->vc_size_row * conp->vc_top,
		      conp->vc_size_row * (conp->vc_bottom - conp->vc_top) / 2);
	return 0;
    }
    return 1;
}