xref: /linux/drivers/tty/vt/vt.c (revision a8b70ccf10e38775785d9cb12ead916474549f99)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 1991, 1992  Linus Torvalds
4  */
5 
6 /*
7  * Hopefully this will be a rather complete VT102 implementation.
8  *
9  * Beeping thanks to John T Kohl.
10  *
11  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
12  *   Chars, and VT100 enhancements by Peter MacDonald.
13  *
14  * Copy and paste function by Andrew Haylett,
15  *   some enhancements by Alessandro Rubini.
16  *
17  * Code to check for different video-cards mostly by Galen Hunt,
18  * <g-hunt@ee.utah.edu>
19  *
20  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
21  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
22  *
23  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
24  * Resizing of consoles, aeb, 940926
25  *
26  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
27  * <poe@daimi.aau.dk>
28  *
29  * User-defined bell sound, new setterm control sequences and printk
30  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
31  *
32  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
33  *
34  * Merge with the abstract console driver by Geert Uytterhoeven
35  * <geert@linux-m68k.org>, Jan 1997.
36  *
37  *   Original m68k console driver modifications by
38  *
39  *     - Arno Griffioen <arno@usn.nl>
40  *     - David Carter <carter@cs.bris.ac.uk>
41  *
42  *   The abstract console driver provides a generic interface for a text
43  *   console. It supports VGA text mode, frame buffer based graphical consoles
44  *   and special graphics processors that are only accessible through some
45  *   registers (e.g. a TMS340x0 GSP).
46  *
47  *   The interface to the hardware is specified using a special structure
48  *   (struct consw) which contains function pointers to console operations
49  *   (see <linux/console.h> for more information).
50  *
51  * Support for changeable cursor shape
52  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
53  *
54  * Ported to i386 and con_scrolldelta fixed
55  * by Emmanuel Marty <core@ggi-project.org>, April 1998
56  *
57  * Resurrected character buffers in videoram plus lots of other trickery
58  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
59  *
60  * Removed old-style timers, introduced console_timer, made timer
61  * deletion SMP-safe.  17Jun00, Andrew Morton
62  *
63  * Removed console_lock, enabled interrupts across all console operations
64  * 13 March 2001, Andrew Morton
65  *
66  * Fixed UTF-8 mode so alternate charset modes always work according
67  * to control sequences interpreted in do_con_trol function
68  * preserving backward VT100 semigraphics compatibility,
69  * malformed UTF sequences represented as sequences of replacement glyphs,
70  * original codes or '?' as a last resort if replacement glyph is undefined
71  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
72  */
73 
74 #include <linux/module.h>
75 #include <linux/types.h>
76 #include <linux/sched/signal.h>
77 #include <linux/tty.h>
78 #include <linux/tty_flip.h>
79 #include <linux/kernel.h>
80 #include <linux/string.h>
81 #include <linux/errno.h>
82 #include <linux/kd.h>
83 #include <linux/slab.h>
84 #include <linux/major.h>
85 #include <linux/mm.h>
86 #include <linux/console.h>
87 #include <linux/init.h>
88 #include <linux/mutex.h>
89 #include <linux/vt_kern.h>
90 #include <linux/selection.h>
91 #include <linux/tiocl.h>
92 #include <linux/kbd_kern.h>
93 #include <linux/consolemap.h>
94 #include <linux/timer.h>
95 #include <linux/interrupt.h>
96 #include <linux/workqueue.h>
97 #include <linux/pm.h>
98 #include <linux/font.h>
99 #include <linux/bitops.h>
100 #include <linux/notifier.h>
101 #include <linux/device.h>
102 #include <linux/io.h>
103 #include <linux/uaccess.h>
104 #include <linux/kdb.h>
105 #include <linux/ctype.h>
106 #include <linux/bsearch.h>
107 
108 #define MAX_NR_CON_DRIVER 16
109 
110 #define CON_DRIVER_FLAG_MODULE 1
111 #define CON_DRIVER_FLAG_INIT   2
112 #define CON_DRIVER_FLAG_ATTR   4
113 #define CON_DRIVER_FLAG_ZOMBIE 8
114 
115 struct con_driver {
116 	const struct consw *con;
117 	const char *desc;
118 	struct device *dev;
119 	int node;
120 	int first;
121 	int last;
122 	int flag;
123 };
124 
125 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
126 const struct consw *conswitchp;
127 
128 /* A bitmap for codes <32. A bit of 1 indicates that the code
129  * corresponding to that bit number invokes some special action
130  * (such as cursor movement) and should not be displayed as a
131  * glyph unless the disp_ctrl mode is explicitly enabled.
132  */
133 #define CTRL_ACTION 0x0d00ff81
134 #define CTRL_ALWAYS 0x0800f501	/* Cannot be overridden by disp_ctrl */
135 
136 /*
137  * Here is the default bell parameters: 750HZ, 1/8th of a second
138  */
139 #define DEFAULT_BELL_PITCH	750
140 #define DEFAULT_BELL_DURATION	(HZ/8)
141 #define DEFAULT_CURSOR_BLINK_MS	200
142 
143 struct vc vc_cons [MAX_NR_CONSOLES];
144 
145 #ifndef VT_SINGLE_DRIVER
146 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
147 #endif
148 
149 static int con_open(struct tty_struct *, struct file *);
150 static void vc_init(struct vc_data *vc, unsigned int rows,
151 		    unsigned int cols, int do_clear);
152 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
153 static void save_cur(struct vc_data *vc);
154 static void reset_terminal(struct vc_data *vc, int do_clear);
155 static void con_flush_chars(struct tty_struct *tty);
156 static int set_vesa_blanking(char __user *p);
157 static void set_cursor(struct vc_data *vc);
158 static void hide_cursor(struct vc_data *vc);
159 static void console_callback(struct work_struct *ignored);
160 static void con_driver_unregister_callback(struct work_struct *ignored);
161 static void blank_screen_t(struct timer_list *unused);
162 static void set_palette(struct vc_data *vc);
163 
164 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
165 
166 static int printable;		/* Is console ready for printing? */
167 int default_utf8 = true;
168 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
169 int global_cursor_default = -1;
170 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
171 
172 static int cur_default = CUR_DEFAULT;
173 module_param(cur_default, int, S_IRUGO | S_IWUSR);
174 
175 /*
176  * ignore_poke: don't unblank the screen when things are typed.  This is
177  * mainly for the privacy of braille terminal users.
178  */
179 static int ignore_poke;
180 
181 int do_poke_blanked_console;
182 int console_blanked;
183 
184 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
185 static int vesa_off_interval;
186 static int blankinterval;
187 core_param(consoleblank, blankinterval, int, 0444);
188 
189 static DECLARE_WORK(console_work, console_callback);
190 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
191 
192 /*
193  * fg_console is the current virtual console,
194  * last_console is the last used one,
195  * want_console is the console we want to switch to,
196  * saved_* variants are for save/restore around kernel debugger enter/leave
197  */
198 int fg_console;
199 int last_console;
200 int want_console = -1;
201 static int saved_fg_console;
202 static int saved_last_console;
203 static int saved_want_console;
204 static int saved_vc_mode;
205 static int saved_console_blanked;
206 
207 /*
208  * For each existing display, we have a pointer to console currently visible
209  * on that display, allowing consoles other than fg_console to be refreshed
210  * appropriately. Unless the low-level driver supplies its own display_fg
211  * variable, we use this one for the "master display".
212  */
213 static struct vc_data *master_display_fg;
214 
215 /*
216  * Unfortunately, we need to delay tty echo when we're currently writing to the
217  * console since the code is (and always was) not re-entrant, so we schedule
218  * all flip requests to process context with schedule-task() and run it from
219  * console_callback().
220  */
221 
222 /*
223  * For the same reason, we defer scrollback to the console callback.
224  */
225 static int scrollback_delta;
226 
227 /*
228  * Hook so that the power management routines can (un)blank
229  * the console on our behalf.
230  */
231 int (*console_blank_hook)(int);
232 
233 static DEFINE_TIMER(console_timer, blank_screen_t);
234 static int blank_state;
235 static int blank_timer_expired;
236 enum {
237 	blank_off = 0,
238 	blank_normal_wait,
239 	blank_vesa_wait,
240 };
241 
242 /*
243  * /sys/class/tty/tty0/
244  *
245  * the attribute 'active' contains the name of the current vc
246  * console and it supports poll() to detect vc switches
247  */
248 static struct device *tty0dev;
249 
250 /*
251  * Notifier list for console events.
252  */
253 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
254 
255 int register_vt_notifier(struct notifier_block *nb)
256 {
257 	return atomic_notifier_chain_register(&vt_notifier_list, nb);
258 }
259 EXPORT_SYMBOL_GPL(register_vt_notifier);
260 
261 int unregister_vt_notifier(struct notifier_block *nb)
262 {
263 	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
264 }
265 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
266 
267 static void notify_write(struct vc_data *vc, unsigned int unicode)
268 {
269 	struct vt_notifier_param param = { .vc = vc, .c = unicode };
270 	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
271 }
272 
273 static void notify_update(struct vc_data *vc)
274 {
275 	struct vt_notifier_param param = { .vc = vc };
276 	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
277 }
278 /*
279  *	Low-Level Functions
280  */
281 
282 static inline bool con_is_fg(const struct vc_data *vc)
283 {
284 	return vc->vc_num == fg_console;
285 }
286 
287 static inline bool con_should_update(const struct vc_data *vc)
288 {
289 	return con_is_visible(vc) && !console_blanked;
290 }
291 
292 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
293 {
294 	unsigned short *p;
295 
296 	if (!viewed)
297 		p = (unsigned short *)(vc->vc_origin + offset);
298 	else if (!vc->vc_sw->con_screen_pos)
299 		p = (unsigned short *)(vc->vc_visible_origin + offset);
300 	else
301 		p = vc->vc_sw->con_screen_pos(vc, offset);
302 	return p;
303 }
304 
305 /* Called  from the keyboard irq path.. */
306 static inline void scrolldelta(int lines)
307 {
308 	/* FIXME */
309 	/* scrolldelta needs some kind of consistency lock, but the BKL was
310 	   and still is not protecting versus the scheduled back end */
311 	scrollback_delta += lines;
312 	schedule_console_callback();
313 }
314 
315 void schedule_console_callback(void)
316 {
317 	schedule_work(&console_work);
318 }
319 
320 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
321 		enum con_scroll dir, unsigned int nr)
322 {
323 	u16 *clear, *d, *s;
324 
325 	if (t + nr >= b)
326 		nr = b - t - 1;
327 	if (b > vc->vc_rows || t >= b || nr < 1)
328 		return;
329 	if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
330 		return;
331 
332 	s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
333 	d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
334 
335 	if (dir == SM_UP) {
336 		clear = s + (b - t - nr) * vc->vc_cols;
337 		swap(s, d);
338 	}
339 	scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
340 	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
341 }
342 
343 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
344 {
345 	unsigned int xx, yy, offset;
346 	u16 *p;
347 
348 	p = (u16 *) start;
349 	if (!vc->vc_sw->con_getxy) {
350 		offset = (start - vc->vc_origin) / 2;
351 		xx = offset % vc->vc_cols;
352 		yy = offset / vc->vc_cols;
353 	} else {
354 		int nxx, nyy;
355 		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
356 		xx = nxx; yy = nyy;
357 	}
358 	for(;;) {
359 		u16 attrib = scr_readw(p) & 0xff00;
360 		int startx = xx;
361 		u16 *q = p;
362 		while (xx < vc->vc_cols && count) {
363 			if (attrib != (scr_readw(p) & 0xff00)) {
364 				if (p > q)
365 					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
366 				startx = xx;
367 				q = p;
368 				attrib = scr_readw(p) & 0xff00;
369 			}
370 			p++;
371 			xx++;
372 			count--;
373 		}
374 		if (p > q)
375 			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
376 		if (!count)
377 			break;
378 		xx = 0;
379 		yy++;
380 		if (vc->vc_sw->con_getxy) {
381 			p = (u16 *)start;
382 			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
383 		}
384 	}
385 }
386 
387 void update_region(struct vc_data *vc, unsigned long start, int count)
388 {
389 	WARN_CONSOLE_UNLOCKED();
390 
391 	if (con_should_update(vc)) {
392 		hide_cursor(vc);
393 		do_update_region(vc, start, count);
394 		set_cursor(vc);
395 	}
396 }
397 
398 /* Structure of attributes is hardware-dependent */
399 
400 static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
401     u8 _underline, u8 _reverse, u8 _italic)
402 {
403 	if (vc->vc_sw->con_build_attr)
404 		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
405 		       _blink, _underline, _reverse, _italic);
406 
407 /*
408  * ++roman: I completely changed the attribute format for monochrome
409  * mode (!can_do_color). The formerly used MDA (monochrome display
410  * adapter) format didn't allow the combination of certain effects.
411  * Now the attribute is just a bit vector:
412  *  Bit 0..1: intensity (0..2)
413  *  Bit 2   : underline
414  *  Bit 3   : reverse
415  *  Bit 7   : blink
416  */
417 	{
418 	u8 a = _color;
419 	if (!vc->vc_can_do_color)
420 		return _intensity |
421 		       (_italic ? 2 : 0) |
422 		       (_underline ? 4 : 0) |
423 		       (_reverse ? 8 : 0) |
424 		       (_blink ? 0x80 : 0);
425 	if (_italic)
426 		a = (a & 0xF0) | vc->vc_itcolor;
427 	else if (_underline)
428 		a = (a & 0xf0) | vc->vc_ulcolor;
429 	else if (_intensity == 0)
430 		a = (a & 0xf0) | vc->vc_halfcolor;
431 	if (_reverse)
432 		a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
433 	if (_blink)
434 		a ^= 0x80;
435 	if (_intensity == 2)
436 		a ^= 0x08;
437 	if (vc->vc_hi_font_mask == 0x100)
438 		a <<= 1;
439 	return a;
440 	}
441 }
442 
443 static void update_attr(struct vc_data *vc)
444 {
445 	vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
446 	              vc->vc_blink, vc->vc_underline,
447 	              vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
448 	vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
449 }
450 
451 /* Note: inverting the screen twice should revert to the original state */
452 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
453 {
454 	unsigned short *p;
455 
456 	WARN_CONSOLE_UNLOCKED();
457 
458 	count /= 2;
459 	p = screenpos(vc, offset, viewed);
460 	if (vc->vc_sw->con_invert_region) {
461 		vc->vc_sw->con_invert_region(vc, p, count);
462 	} else {
463 		u16 *q = p;
464 		int cnt = count;
465 		u16 a;
466 
467 		if (!vc->vc_can_do_color) {
468 			while (cnt--) {
469 			    a = scr_readw(q);
470 			    a ^= 0x0800;
471 			    scr_writew(a, q);
472 			    q++;
473 			}
474 		} else if (vc->vc_hi_font_mask == 0x100) {
475 			while (cnt--) {
476 				a = scr_readw(q);
477 				a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
478 				scr_writew(a, q);
479 				q++;
480 			}
481 		} else {
482 			while (cnt--) {
483 				a = scr_readw(q);
484 				a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
485 				scr_writew(a, q);
486 				q++;
487 			}
488 		}
489 	}
490 
491 	if (con_should_update(vc))
492 		do_update_region(vc, (unsigned long) p, count);
493 	notify_update(vc);
494 }
495 
496 /* used by selection: complement pointer position */
497 void complement_pos(struct vc_data *vc, int offset)
498 {
499 	static int old_offset = -1;
500 	static unsigned short old;
501 	static unsigned short oldx, oldy;
502 
503 	WARN_CONSOLE_UNLOCKED();
504 
505 	if (old_offset != -1 && old_offset >= 0 &&
506 	    old_offset < vc->vc_screenbuf_size) {
507 		scr_writew(old, screenpos(vc, old_offset, 1));
508 		if (con_should_update(vc))
509 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
510 		notify_update(vc);
511 	}
512 
513 	old_offset = offset;
514 
515 	if (offset != -1 && offset >= 0 &&
516 	    offset < vc->vc_screenbuf_size) {
517 		unsigned short new;
518 		unsigned short *p;
519 		p = screenpos(vc, offset, 1);
520 		old = scr_readw(p);
521 		new = old ^ vc->vc_complement_mask;
522 		scr_writew(new, p);
523 		if (con_should_update(vc)) {
524 			oldx = (offset >> 1) % vc->vc_cols;
525 			oldy = (offset >> 1) / vc->vc_cols;
526 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
527 		}
528 		notify_update(vc);
529 	}
530 }
531 
532 static void insert_char(struct vc_data *vc, unsigned int nr)
533 {
534 	unsigned short *p = (unsigned short *) vc->vc_pos;
535 
536 	scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
537 	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
538 	vc->vc_need_wrap = 0;
539 	if (con_should_update(vc))
540 		do_update_region(vc, (unsigned long) p,
541 			vc->vc_cols - vc->vc_x);
542 }
543 
544 static void delete_char(struct vc_data *vc, unsigned int nr)
545 {
546 	unsigned short *p = (unsigned short *) vc->vc_pos;
547 
548 	scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
549 	scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
550 			nr * 2);
551 	vc->vc_need_wrap = 0;
552 	if (con_should_update(vc))
553 		do_update_region(vc, (unsigned long) p,
554 			vc->vc_cols - vc->vc_x);
555 }
556 
557 static int softcursor_original = -1;
558 
559 static void add_softcursor(struct vc_data *vc)
560 {
561 	int i = scr_readw((u16 *) vc->vc_pos);
562 	u32 type = vc->vc_cursor_type;
563 
564 	if (! (type & 0x10)) return;
565 	if (softcursor_original != -1) return;
566 	softcursor_original = i;
567 	i |= ((type >> 8) & 0xff00 );
568 	i ^= ((type) & 0xff00 );
569 	if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
570 	if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
571 	scr_writew(i, (u16 *) vc->vc_pos);
572 	if (con_should_update(vc))
573 		vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
574 }
575 
576 static void hide_softcursor(struct vc_data *vc)
577 {
578 	if (softcursor_original != -1) {
579 		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
580 		if (con_should_update(vc))
581 			vc->vc_sw->con_putc(vc, softcursor_original,
582 					vc->vc_y, vc->vc_x);
583 		softcursor_original = -1;
584 	}
585 }
586 
587 static void hide_cursor(struct vc_data *vc)
588 {
589 	if (vc == sel_cons)
590 		clear_selection();
591 	vc->vc_sw->con_cursor(vc, CM_ERASE);
592 	hide_softcursor(vc);
593 }
594 
595 static void set_cursor(struct vc_data *vc)
596 {
597 	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
598 		return;
599 	if (vc->vc_deccm) {
600 		if (vc == sel_cons)
601 			clear_selection();
602 		add_softcursor(vc);
603 		if ((vc->vc_cursor_type & 0x0f) != 1)
604 			vc->vc_sw->con_cursor(vc, CM_DRAW);
605 	} else
606 		hide_cursor(vc);
607 }
608 
609 static void set_origin(struct vc_data *vc)
610 {
611 	WARN_CONSOLE_UNLOCKED();
612 
613 	if (!con_is_visible(vc) ||
614 	    !vc->vc_sw->con_set_origin ||
615 	    !vc->vc_sw->con_set_origin(vc))
616 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
617 	vc->vc_visible_origin = vc->vc_origin;
618 	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
619 	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
620 }
621 
622 static void save_screen(struct vc_data *vc)
623 {
624 	WARN_CONSOLE_UNLOCKED();
625 
626 	if (vc->vc_sw->con_save_screen)
627 		vc->vc_sw->con_save_screen(vc);
628 }
629 
630 static void flush_scrollback(struct vc_data *vc)
631 {
632 	WARN_CONSOLE_UNLOCKED();
633 
634 	if (vc->vc_sw->con_flush_scrollback)
635 		vc->vc_sw->con_flush_scrollback(vc);
636 }
637 
638 /*
639  *	Redrawing of screen
640  */
641 
642 void clear_buffer_attributes(struct vc_data *vc)
643 {
644 	unsigned short *p = (unsigned short *)vc->vc_origin;
645 	int count = vc->vc_screenbuf_size / 2;
646 	int mask = vc->vc_hi_font_mask | 0xff;
647 
648 	for (; count > 0; count--, p++) {
649 		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
650 	}
651 }
652 
653 void redraw_screen(struct vc_data *vc, int is_switch)
654 {
655 	int redraw = 0;
656 
657 	WARN_CONSOLE_UNLOCKED();
658 
659 	if (!vc) {
660 		/* strange ... */
661 		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
662 		return;
663 	}
664 
665 	if (is_switch) {
666 		struct vc_data *old_vc = vc_cons[fg_console].d;
667 		if (old_vc == vc)
668 			return;
669 		if (!con_is_visible(vc))
670 			redraw = 1;
671 		*vc->vc_display_fg = vc;
672 		fg_console = vc->vc_num;
673 		hide_cursor(old_vc);
674 		if (!con_is_visible(old_vc)) {
675 			save_screen(old_vc);
676 			set_origin(old_vc);
677 		}
678 		if (tty0dev)
679 			sysfs_notify(&tty0dev->kobj, NULL, "active");
680 	} else {
681 		hide_cursor(vc);
682 		redraw = 1;
683 	}
684 
685 	if (redraw) {
686 		int update;
687 		int old_was_color = vc->vc_can_do_color;
688 
689 		set_origin(vc);
690 		update = vc->vc_sw->con_switch(vc);
691 		set_palette(vc);
692 		/*
693 		 * If console changed from mono<->color, the best we can do
694 		 * is to clear the buffer attributes. As it currently stands,
695 		 * rebuilding new attributes from the old buffer is not doable
696 		 * without overly complex code.
697 		 */
698 		if (old_was_color != vc->vc_can_do_color) {
699 			update_attr(vc);
700 			clear_buffer_attributes(vc);
701 		}
702 
703 		/* Forcibly update if we're panicing */
704 		if ((update && vc->vc_mode != KD_GRAPHICS) ||
705 		    vt_force_oops_output(vc))
706 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
707 	}
708 	set_cursor(vc);
709 	if (is_switch) {
710 		set_leds();
711 		compute_shiftstate();
712 		notify_update(vc);
713 	}
714 }
715 
716 /*
717  *	Allocation, freeing and resizing of VTs.
718  */
719 
720 int vc_cons_allocated(unsigned int i)
721 {
722 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
723 }
724 
725 static void visual_init(struct vc_data *vc, int num, int init)
726 {
727 	/* ++Geert: vc->vc_sw->con_init determines console size */
728 	if (vc->vc_sw)
729 		module_put(vc->vc_sw->owner);
730 	vc->vc_sw = conswitchp;
731 #ifndef VT_SINGLE_DRIVER
732 	if (con_driver_map[num])
733 		vc->vc_sw = con_driver_map[num];
734 #endif
735 	__module_get(vc->vc_sw->owner);
736 	vc->vc_num = num;
737 	vc->vc_display_fg = &master_display_fg;
738 	if (vc->vc_uni_pagedir_loc)
739 		con_free_unimap(vc);
740 	vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
741 	vc->vc_uni_pagedir = NULL;
742 	vc->vc_hi_font_mask = 0;
743 	vc->vc_complement_mask = 0;
744 	vc->vc_can_do_color = 0;
745 	vc->vc_panic_force_write = false;
746 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
747 	vc->vc_sw->con_init(vc, init);
748 	if (!vc->vc_complement_mask)
749 		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
750 	vc->vc_s_complement_mask = vc->vc_complement_mask;
751 	vc->vc_size_row = vc->vc_cols << 1;
752 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
753 }
754 
755 int vc_allocate(unsigned int currcons)	/* return 0 on success */
756 {
757 	struct vt_notifier_param param;
758 	struct vc_data *vc;
759 
760 	WARN_CONSOLE_UNLOCKED();
761 
762 	if (currcons >= MAX_NR_CONSOLES)
763 		return -ENXIO;
764 
765 	if (vc_cons[currcons].d)
766 		return 0;
767 
768 	/* due to the granularity of kmalloc, we waste some memory here */
769 	/* the alloc is done in two steps, to optimize the common situation
770 	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
771 	/* although the numbers above are not valid since long ago, the
772 	   point is still up-to-date and the comment still has its value
773 	   even if only as a historical artifact.  --mj, July 1998 */
774 	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
775 	if (!vc)
776 		return -ENOMEM;
777 
778 	vc_cons[currcons].d = vc;
779 	tty_port_init(&vc->port);
780 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
781 
782 	visual_init(vc, currcons, 1);
783 
784 	if (!*vc->vc_uni_pagedir_loc)
785 		con_set_default_unimap(vc);
786 
787 	vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
788 	if (!vc->vc_screenbuf)
789 		goto err_free;
790 
791 	/* If no drivers have overridden us and the user didn't pass a
792 	   boot option, default to displaying the cursor */
793 	if (global_cursor_default == -1)
794 		global_cursor_default = 1;
795 
796 	vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
797 	vcs_make_sysfs(currcons);
798 	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
799 
800 	return 0;
801 err_free:
802 	kfree(vc);
803 	vc_cons[currcons].d = NULL;
804 	return -ENOMEM;
805 }
806 
807 static inline int resize_screen(struct vc_data *vc, int width, int height,
808 				int user)
809 {
810 	/* Resizes the resolution of the display adapater */
811 	int err = 0;
812 
813 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
814 		err = vc->vc_sw->con_resize(vc, width, height, user);
815 
816 	return err;
817 }
818 
819 /*
820  * Change # of rows and columns (0 means unchanged/the size of fg_console)
821  * [this is to be used together with some user program
822  * like resize that changes the hardware videomode]
823  */
824 #define VC_RESIZE_MAXCOL (32767)
825 #define VC_RESIZE_MAXROW (32767)
826 
827 /**
828  *	vc_do_resize	-	resizing method for the tty
829  *	@tty: tty being resized
830  *	@real_tty: real tty (different to tty if a pty/tty pair)
831  *	@vc: virtual console private data
832  *	@cols: columns
833  *	@lines: lines
834  *
835  *	Resize a virtual console, clipping according to the actual constraints.
836  *	If the caller passes a tty structure then update the termios winsize
837  *	information and perform any necessary signal handling.
838  *
839  *	Caller must hold the console semaphore. Takes the termios rwsem and
840  *	ctrl_lock of the tty IFF a tty is passed.
841  */
842 
843 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
844 				unsigned int cols, unsigned int lines)
845 {
846 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
847 	unsigned long end;
848 	unsigned int old_rows, old_row_size;
849 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
850 	unsigned int user;
851 	unsigned short *newscreen;
852 
853 	WARN_CONSOLE_UNLOCKED();
854 
855 	if (!vc)
856 		return -ENXIO;
857 
858 	user = vc->vc_resize_user;
859 	vc->vc_resize_user = 0;
860 
861 	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
862 		return -EINVAL;
863 
864 	new_cols = (cols ? cols : vc->vc_cols);
865 	new_rows = (lines ? lines : vc->vc_rows);
866 	new_row_size = new_cols << 1;
867 	new_screen_size = new_row_size * new_rows;
868 
869 	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
870 		return 0;
871 
872 	if (new_screen_size > (4 << 20))
873 		return -EINVAL;
874 	newscreen = kmalloc(new_screen_size, GFP_USER);
875 	if (!newscreen)
876 		return -ENOMEM;
877 
878 	if (vc == sel_cons)
879 		clear_selection();
880 
881 	old_rows = vc->vc_rows;
882 	old_row_size = vc->vc_size_row;
883 
884 	err = resize_screen(vc, new_cols, new_rows, user);
885 	if (err) {
886 		kfree(newscreen);
887 		return err;
888 	}
889 
890 	vc->vc_rows = new_rows;
891 	vc->vc_cols = new_cols;
892 	vc->vc_size_row = new_row_size;
893 	vc->vc_screenbuf_size = new_screen_size;
894 
895 	rlth = min(old_row_size, new_row_size);
896 	rrem = new_row_size - rlth;
897 	old_origin = vc->vc_origin;
898 	new_origin = (long) newscreen;
899 	new_scr_end = new_origin + new_screen_size;
900 
901 	if (vc->vc_y > new_rows) {
902 		if (old_rows - vc->vc_y < new_rows) {
903 			/*
904 			 * Cursor near the bottom, copy contents from the
905 			 * bottom of buffer
906 			 */
907 			old_origin += (old_rows - new_rows) * old_row_size;
908 		} else {
909 			/*
910 			 * Cursor is in no man's land, copy 1/2 screenful
911 			 * from the top and bottom of cursor position
912 			 */
913 			old_origin += (vc->vc_y - new_rows/2) * old_row_size;
914 		}
915 	}
916 
917 	end = old_origin + old_row_size * min(old_rows, new_rows);
918 
919 	update_attr(vc);
920 
921 	while (old_origin < end) {
922 		scr_memcpyw((unsigned short *) new_origin,
923 			    (unsigned short *) old_origin, rlth);
924 		if (rrem)
925 			scr_memsetw((void *)(new_origin + rlth),
926 				    vc->vc_video_erase_char, rrem);
927 		old_origin += old_row_size;
928 		new_origin += new_row_size;
929 	}
930 	if (new_scr_end > new_origin)
931 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
932 			    new_scr_end - new_origin);
933 	kfree(vc->vc_screenbuf);
934 	vc->vc_screenbuf = newscreen;
935 	vc->vc_screenbuf_size = new_screen_size;
936 	set_origin(vc);
937 
938 	/* do part of a reset_terminal() */
939 	vc->vc_top = 0;
940 	vc->vc_bottom = vc->vc_rows;
941 	gotoxy(vc, vc->vc_x, vc->vc_y);
942 	save_cur(vc);
943 
944 	if (tty) {
945 		/* Rewrite the requested winsize data with the actual
946 		   resulting sizes */
947 		struct winsize ws;
948 		memset(&ws, 0, sizeof(ws));
949 		ws.ws_row = vc->vc_rows;
950 		ws.ws_col = vc->vc_cols;
951 		ws.ws_ypixel = vc->vc_scan_lines;
952 		tty_do_resize(tty, &ws);
953 	}
954 
955 	if (con_is_visible(vc))
956 		update_screen(vc);
957 	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
958 	return err;
959 }
960 
961 /**
962  *	vc_resize		-	resize a VT
963  *	@vc: virtual console
964  *	@cols: columns
965  *	@rows: rows
966  *
967  *	Resize a virtual console as seen from the console end of things. We
968  *	use the common vc_do_resize methods to update the structures. The
969  *	caller must hold the console sem to protect console internals and
970  *	vc->port.tty
971  */
972 
973 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
974 {
975 	return vc_do_resize(vc->port.tty, vc, cols, rows);
976 }
977 
978 /**
979  *	vt_resize		-	resize a VT
980  *	@tty: tty to resize
981  *	@ws: winsize attributes
982  *
983  *	Resize a virtual terminal. This is called by the tty layer as we
984  *	register our own handler for resizing. The mutual helper does all
985  *	the actual work.
986  *
987  *	Takes the console sem and the called methods then take the tty
988  *	termios_rwsem and the tty ctrl_lock in that order.
989  */
990 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
991 {
992 	struct vc_data *vc = tty->driver_data;
993 	int ret;
994 
995 	console_lock();
996 	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
997 	console_unlock();
998 	return ret;
999 }
1000 
1001 struct vc_data *vc_deallocate(unsigned int currcons)
1002 {
1003 	struct vc_data *vc = NULL;
1004 
1005 	WARN_CONSOLE_UNLOCKED();
1006 
1007 	if (vc_cons_allocated(currcons)) {
1008 		struct vt_notifier_param param;
1009 
1010 		param.vc = vc = vc_cons[currcons].d;
1011 		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1012 		vcs_remove_sysfs(currcons);
1013 		vc->vc_sw->con_deinit(vc);
1014 		put_pid(vc->vt_pid);
1015 		module_put(vc->vc_sw->owner);
1016 		kfree(vc->vc_screenbuf);
1017 		vc_cons[currcons].d = NULL;
1018 	}
1019 	return vc;
1020 }
1021 
1022 /*
1023  *	VT102 emulator
1024  */
1025 
1026 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1027 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1028 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1029 
1030 #define decarm		VC_REPEAT
1031 #define decckm		VC_CKMODE
1032 #define kbdapplic	VC_APPLIC
1033 #define lnm		VC_CRLF
1034 
1035 /*
1036  * this is what the terminal answers to a ESC-Z or csi0c query.
1037  */
1038 #define VT100ID "\033[?1;2c"
1039 #define VT102ID "\033[?6c"
1040 
1041 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1042 				       8,12,10,14, 9,13,11,15 };
1043 
1044 /* the default colour table, for VGA+ colour systems */
1045 unsigned char default_red[] = {
1046 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1047 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1048 };
1049 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1050 
1051 unsigned char default_grn[] = {
1052 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1053 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1054 };
1055 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1056 
1057 unsigned char default_blu[] = {
1058 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1059 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1060 };
1061 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1062 
1063 /*
1064  * gotoxy() must verify all boundaries, because the arguments
1065  * might also be negative. If the given position is out of
1066  * bounds, the cursor is placed at the nearest margin.
1067  */
1068 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1069 {
1070 	int min_y, max_y;
1071 
1072 	if (new_x < 0)
1073 		vc->vc_x = 0;
1074 	else {
1075 		if (new_x >= vc->vc_cols)
1076 			vc->vc_x = vc->vc_cols - 1;
1077 		else
1078 			vc->vc_x = new_x;
1079 	}
1080 
1081  	if (vc->vc_decom) {
1082 		min_y = vc->vc_top;
1083 		max_y = vc->vc_bottom;
1084 	} else {
1085 		min_y = 0;
1086 		max_y = vc->vc_rows;
1087 	}
1088 	if (new_y < min_y)
1089 		vc->vc_y = min_y;
1090 	else if (new_y >= max_y)
1091 		vc->vc_y = max_y - 1;
1092 	else
1093 		vc->vc_y = new_y;
1094 	vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
1095 	vc->vc_need_wrap = 0;
1096 }
1097 
1098 /* for absolute user moves, when decom is set */
1099 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1100 {
1101 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1102 }
1103 
1104 void scrollback(struct vc_data *vc)
1105 {
1106 	scrolldelta(-(vc->vc_rows / 2));
1107 }
1108 
1109 void scrollfront(struct vc_data *vc, int lines)
1110 {
1111 	if (!lines)
1112 		lines = vc->vc_rows / 2;
1113 	scrolldelta(lines);
1114 }
1115 
1116 static void lf(struct vc_data *vc)
1117 {
1118     	/* don't scroll if above bottom of scrolling region, or
1119 	 * if below scrolling region
1120 	 */
1121     	if (vc->vc_y + 1 == vc->vc_bottom)
1122 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1123 	else if (vc->vc_y < vc->vc_rows - 1) {
1124 	    	vc->vc_y++;
1125 		vc->vc_pos += vc->vc_size_row;
1126 	}
1127 	vc->vc_need_wrap = 0;
1128 	notify_write(vc, '\n');
1129 }
1130 
1131 static void ri(struct vc_data *vc)
1132 {
1133     	/* don't scroll if below top of scrolling region, or
1134 	 * if above scrolling region
1135 	 */
1136 	if (vc->vc_y == vc->vc_top)
1137 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1138 	else if (vc->vc_y > 0) {
1139 		vc->vc_y--;
1140 		vc->vc_pos -= vc->vc_size_row;
1141 	}
1142 	vc->vc_need_wrap = 0;
1143 }
1144 
1145 static inline void cr(struct vc_data *vc)
1146 {
1147 	vc->vc_pos -= vc->vc_x << 1;
1148 	vc->vc_need_wrap = vc->vc_x = 0;
1149 	notify_write(vc, '\r');
1150 }
1151 
1152 static inline void bs(struct vc_data *vc)
1153 {
1154 	if (vc->vc_x) {
1155 		vc->vc_pos -= 2;
1156 		vc->vc_x--;
1157 		vc->vc_need_wrap = 0;
1158 		notify_write(vc, '\b');
1159 	}
1160 }
1161 
1162 static inline void del(struct vc_data *vc)
1163 {
1164 	/* ignored */
1165 }
1166 
1167 static void csi_J(struct vc_data *vc, int vpar)
1168 {
1169 	unsigned int count;
1170 	unsigned short * start;
1171 
1172 	switch (vpar) {
1173 		case 0:	/* erase from cursor to end of display */
1174 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1175 			start = (unsigned short *)vc->vc_pos;
1176 			break;
1177 		case 1:	/* erase from start to cursor */
1178 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1179 			start = (unsigned short *)vc->vc_origin;
1180 			break;
1181 		case 3: /* erase scroll-back buffer (and whole display) */
1182 			scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
1183 				    vc->vc_screenbuf_size);
1184 			flush_scrollback(vc);
1185 			set_origin(vc);
1186 			if (con_is_visible(vc))
1187 				update_screen(vc);
1188 			/* fall through */
1189 		case 2: /* erase whole display */
1190 			count = vc->vc_cols * vc->vc_rows;
1191 			start = (unsigned short *)vc->vc_origin;
1192 			break;
1193 		default:
1194 			return;
1195 	}
1196 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1197 	if (con_should_update(vc))
1198 		do_update_region(vc, (unsigned long) start, count);
1199 	vc->vc_need_wrap = 0;
1200 }
1201 
1202 static void csi_K(struct vc_data *vc, int vpar)
1203 {
1204 	unsigned int count;
1205 	unsigned short * start;
1206 
1207 	switch (vpar) {
1208 		case 0:	/* erase from cursor to end of line */
1209 			count = vc->vc_cols - vc->vc_x;
1210 			start = (unsigned short *)vc->vc_pos;
1211 			break;
1212 		case 1:	/* erase from start of line to cursor */
1213 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1214 			count = vc->vc_x + 1;
1215 			break;
1216 		case 2: /* erase whole line */
1217 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1218 			count = vc->vc_cols;
1219 			break;
1220 		default:
1221 			return;
1222 	}
1223 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1224 	vc->vc_need_wrap = 0;
1225 	if (con_should_update(vc))
1226 		do_update_region(vc, (unsigned long) start, count);
1227 }
1228 
1229 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1230 {					  /* not vt100? */
1231 	int count;
1232 
1233 	if (!vpar)
1234 		vpar++;
1235 	count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
1236 
1237 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1238 	if (con_should_update(vc))
1239 		vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
1240 	vc->vc_need_wrap = 0;
1241 }
1242 
1243 static void default_attr(struct vc_data *vc)
1244 {
1245 	vc->vc_intensity = 1;
1246 	vc->vc_italic = 0;
1247 	vc->vc_underline = 0;
1248 	vc->vc_reverse = 0;
1249 	vc->vc_blink = 0;
1250 	vc->vc_color = vc->vc_def_color;
1251 }
1252 
1253 struct rgb { u8 r; u8 g; u8 b; };
1254 
1255 static void rgb_from_256(int i, struct rgb *c)
1256 {
1257 	if (i < 8) {            /* Standard colours. */
1258 		c->r = i&1 ? 0xaa : 0x00;
1259 		c->g = i&2 ? 0xaa : 0x00;
1260 		c->b = i&4 ? 0xaa : 0x00;
1261 	} else if (i < 16) {
1262 		c->r = i&1 ? 0xff : 0x55;
1263 		c->g = i&2 ? 0xff : 0x55;
1264 		c->b = i&4 ? 0xff : 0x55;
1265 	} else if (i < 232) {   /* 6x6x6 colour cube. */
1266 		c->r = (i - 16) / 36 * 85 / 2;
1267 		c->g = (i - 16) / 6 % 6 * 85 / 2;
1268 		c->b = (i - 16) % 6 * 85 / 2;
1269 	} else                  /* Grayscale ramp. */
1270 		c->r = c->g = c->b = i * 10 - 2312;
1271 }
1272 
1273 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1274 {
1275 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1276 
1277 	if (c->r > max / 2)
1278 		hue |= 4;
1279 	if (c->g > max / 2)
1280 		hue |= 2;
1281 	if (c->b > max / 2)
1282 		hue |= 1;
1283 
1284 	if (hue == 7 && max <= 0x55) {
1285 		hue = 0;
1286 		vc->vc_intensity = 2;
1287 	} else if (max > 0xaa)
1288 		vc->vc_intensity = 2;
1289 	else
1290 		vc->vc_intensity = 1;
1291 
1292 	vc->vc_color = (vc->vc_color & 0xf0) | hue;
1293 }
1294 
1295 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1296 {
1297 	/* For backgrounds, err on the dark side. */
1298 	vc->vc_color = (vc->vc_color & 0x0f)
1299 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1300 }
1301 
1302 /*
1303  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1304  * and thus need to be detected and ignored by hand. Strictly speaking, that
1305  * standard also wants : rather than ; as separators, contrary to ECMA-48, but
1306  * no one produces such codes and almost no one accepts them.
1307  *
1308  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1309  * supporting them.
1310  */
1311 static int vc_t416_color(struct vc_data *vc, int i,
1312 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1313 {
1314 	struct rgb c;
1315 
1316 	i++;
1317 	if (i > vc->vc_npar)
1318 		return i;
1319 
1320 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1321 		/* 256 colours */
1322 		i++;
1323 		rgb_from_256(vc->vc_par[i], &c);
1324 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1325 		/* 24 bit */
1326 		c.r = vc->vc_par[i + 1];
1327 		c.g = vc->vc_par[i + 2];
1328 		c.b = vc->vc_par[i + 3];
1329 		i += 3;
1330 	} else
1331 		return i;
1332 
1333 	set_color(vc, &c);
1334 
1335 	return i;
1336 }
1337 
1338 /* console_lock is held */
1339 static void csi_m(struct vc_data *vc)
1340 {
1341 	int i;
1342 
1343 	for (i = 0; i <= vc->vc_npar; i++)
1344 		switch (vc->vc_par[i]) {
1345 		case 0:	/* all attributes off */
1346 			default_attr(vc);
1347 			break;
1348 		case 1:
1349 			vc->vc_intensity = 2;
1350 			break;
1351 		case 2:
1352 			vc->vc_intensity = 0;
1353 			break;
1354 		case 3:
1355 			vc->vc_italic = 1;
1356 			break;
1357 		case 21:
1358 			/*
1359 			 * No console drivers support double underline, so
1360 			 * convert it to a single underline.
1361 			 */
1362 		case 4:
1363 			vc->vc_underline = 1;
1364 			break;
1365 		case 5:
1366 			vc->vc_blink = 1;
1367 			break;
1368 		case 7:
1369 			vc->vc_reverse = 1;
1370 			break;
1371 		case 10: /* ANSI X3.64-1979 (SCO-ish?)
1372 			  * Select primary font, don't display control chars if
1373 			  * defined, don't set bit 8 on output.
1374 			  */
1375 			vc->vc_translate = set_translate(vc->vc_charset == 0
1376 					? vc->vc_G0_charset
1377 					: vc->vc_G1_charset, vc);
1378 			vc->vc_disp_ctrl = 0;
1379 			vc->vc_toggle_meta = 0;
1380 			break;
1381 		case 11: /* ANSI X3.64-1979 (SCO-ish?)
1382 			  * Select first alternate font, lets chars < 32 be
1383 			  * displayed as ROM chars.
1384 			  */
1385 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1386 			vc->vc_disp_ctrl = 1;
1387 			vc->vc_toggle_meta = 0;
1388 			break;
1389 		case 12: /* ANSI X3.64-1979 (SCO-ish?)
1390 			  * Select second alternate font, toggle high bit
1391 			  * before displaying as ROM char.
1392 			  */
1393 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1394 			vc->vc_disp_ctrl = 1;
1395 			vc->vc_toggle_meta = 1;
1396 			break;
1397 		case 22:
1398 			vc->vc_intensity = 1;
1399 			break;
1400 		case 23:
1401 			vc->vc_italic = 0;
1402 			break;
1403 		case 24:
1404 			vc->vc_underline = 0;
1405 			break;
1406 		case 25:
1407 			vc->vc_blink = 0;
1408 			break;
1409 		case 27:
1410 			vc->vc_reverse = 0;
1411 			break;
1412 		case 38:
1413 			i = vc_t416_color(vc, i, rgb_foreground);
1414 			break;
1415 		case 48:
1416 			i = vc_t416_color(vc, i, rgb_background);
1417 			break;
1418 		case 39:
1419 			vc->vc_color = (vc->vc_def_color & 0x0f) |
1420 				(vc->vc_color & 0xf0);
1421 			break;
1422 		case 49:
1423 			vc->vc_color = (vc->vc_def_color & 0xf0) |
1424 				(vc->vc_color & 0x0f);
1425 			break;
1426 		default:
1427 			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1428 				if (vc->vc_par[i] < 100)
1429 					vc->vc_intensity = 2;
1430 				vc->vc_par[i] -= 60;
1431 			}
1432 			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1433 				vc->vc_color = color_table[vc->vc_par[i] - 30]
1434 					| (vc->vc_color & 0xf0);
1435 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1436 				vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1437 					| (vc->vc_color & 0x0f);
1438 			break;
1439 		}
1440 	update_attr(vc);
1441 }
1442 
1443 static void respond_string(const char *p, struct tty_port *port)
1444 {
1445 	while (*p) {
1446 		tty_insert_flip_char(port, *p, 0);
1447 		p++;
1448 	}
1449 	tty_schedule_flip(port);
1450 }
1451 
1452 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1453 {
1454 	char buf[40];
1455 
1456 	sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1457 	respond_string(buf, tty->port);
1458 }
1459 
1460 static inline void status_report(struct tty_struct *tty)
1461 {
1462 	respond_string("\033[0n", tty->port);	/* Terminal ok */
1463 }
1464 
1465 static inline void respond_ID(struct tty_struct *tty)
1466 {
1467 	respond_string(VT102ID, tty->port);
1468 }
1469 
1470 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1471 {
1472 	char buf[8];
1473 
1474 	sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1475 		(char)('!' + mry));
1476 	respond_string(buf, tty->port);
1477 }
1478 
1479 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1480 int mouse_reporting(void)
1481 {
1482 	return vc_cons[fg_console].d->vc_report_mouse;
1483 }
1484 
1485 /* console_lock is held */
1486 static void set_mode(struct vc_data *vc, int on_off)
1487 {
1488 	int i;
1489 
1490 	for (i = 0; i <= vc->vc_npar; i++)
1491 		if (vc->vc_ques) {
1492 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1493 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1494 				if (on_off)
1495 					set_kbd(vc, decckm);
1496 				else
1497 					clr_kbd(vc, decckm);
1498 				break;
1499 			case 3:	/* 80/132 mode switch unimplemented */
1500 #if 0
1501 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1502 				/* this alone does not suffice; some user mode
1503 				   utility has to change the hardware regs */
1504 #endif
1505 				break;
1506 			case 5:			/* Inverted screen on/off */
1507 				if (vc->vc_decscnm != on_off) {
1508 					vc->vc_decscnm = on_off;
1509 					invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1510 					update_attr(vc);
1511 				}
1512 				break;
1513 			case 6:			/* Origin relative/absolute */
1514 				vc->vc_decom = on_off;
1515 				gotoxay(vc, 0, 0);
1516 				break;
1517 			case 7:			/* Autowrap on/off */
1518 				vc->vc_decawm = on_off;
1519 				break;
1520 			case 8:			/* Autorepeat on/off */
1521 				if (on_off)
1522 					set_kbd(vc, decarm);
1523 				else
1524 					clr_kbd(vc, decarm);
1525 				break;
1526 			case 9:
1527 				vc->vc_report_mouse = on_off ? 1 : 0;
1528 				break;
1529 			case 25:		/* Cursor on/off */
1530 				vc->vc_deccm = on_off;
1531 				break;
1532 			case 1000:
1533 				vc->vc_report_mouse = on_off ? 2 : 0;
1534 				break;
1535 			}
1536 		} else {
1537 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1538 			case 3:			/* Monitor (display ctrls) */
1539 				vc->vc_disp_ctrl = on_off;
1540 				break;
1541 			case 4:			/* Insert Mode on/off */
1542 				vc->vc_decim = on_off;
1543 				break;
1544 			case 20:		/* Lf, Enter == CrLf/Lf */
1545 				if (on_off)
1546 					set_kbd(vc, lnm);
1547 				else
1548 					clr_kbd(vc, lnm);
1549 				break;
1550 			}
1551 		}
1552 }
1553 
1554 /* console_lock is held */
1555 static void setterm_command(struct vc_data *vc)
1556 {
1557 	switch(vc->vc_par[0]) {
1558 		case 1:	/* set color for underline mode */
1559 			if (vc->vc_can_do_color &&
1560 					vc->vc_par[1] < 16) {
1561 				vc->vc_ulcolor = color_table[vc->vc_par[1]];
1562 				if (vc->vc_underline)
1563 					update_attr(vc);
1564 			}
1565 			break;
1566 		case 2:	/* set color for half intensity mode */
1567 			if (vc->vc_can_do_color &&
1568 					vc->vc_par[1] < 16) {
1569 				vc->vc_halfcolor = color_table[vc->vc_par[1]];
1570 				if (vc->vc_intensity == 0)
1571 					update_attr(vc);
1572 			}
1573 			break;
1574 		case 8:	/* store colors as defaults */
1575 			vc->vc_def_color = vc->vc_attr;
1576 			if (vc->vc_hi_font_mask == 0x100)
1577 				vc->vc_def_color >>= 1;
1578 			default_attr(vc);
1579 			update_attr(vc);
1580 			break;
1581 		case 9:	/* set blanking interval */
1582 			blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1583 			poke_blanked_console();
1584 			break;
1585 		case 10: /* set bell frequency in Hz */
1586 			if (vc->vc_npar >= 1)
1587 				vc->vc_bell_pitch = vc->vc_par[1];
1588 			else
1589 				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1590 			break;
1591 		case 11: /* set bell duration in msec */
1592 			if (vc->vc_npar >= 1)
1593 				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1594 					msecs_to_jiffies(vc->vc_par[1]) : 0;
1595 			else
1596 				vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1597 			break;
1598 		case 12: /* bring specified console to the front */
1599 			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1600 				set_console(vc->vc_par[1] - 1);
1601 			break;
1602 		case 13: /* unblank the screen */
1603 			poke_blanked_console();
1604 			break;
1605 		case 14: /* set vesa powerdown interval */
1606 			vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1607 			break;
1608 		case 15: /* activate the previous console */
1609 			set_console(last_console);
1610 			break;
1611 		case 16: /* set cursor blink duration in msec */
1612 			if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1613 					vc->vc_par[1] <= USHRT_MAX)
1614 				vc->vc_cur_blink_ms = vc->vc_par[1];
1615 			else
1616 				vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1617 			break;
1618 	}
1619 }
1620 
1621 /* console_lock is held */
1622 static void csi_at(struct vc_data *vc, unsigned int nr)
1623 {
1624 	if (nr > vc->vc_cols - vc->vc_x)
1625 		nr = vc->vc_cols - vc->vc_x;
1626 	else if (!nr)
1627 		nr = 1;
1628 	insert_char(vc, nr);
1629 }
1630 
1631 /* console_lock is held */
1632 static void csi_L(struct vc_data *vc, unsigned int nr)
1633 {
1634 	if (nr > vc->vc_rows - vc->vc_y)
1635 		nr = vc->vc_rows - vc->vc_y;
1636 	else if (!nr)
1637 		nr = 1;
1638 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_DOWN, nr);
1639 	vc->vc_need_wrap = 0;
1640 }
1641 
1642 /* console_lock is held */
1643 static void csi_P(struct vc_data *vc, unsigned int nr)
1644 {
1645 	if (nr > vc->vc_cols - vc->vc_x)
1646 		nr = vc->vc_cols - vc->vc_x;
1647 	else if (!nr)
1648 		nr = 1;
1649 	delete_char(vc, nr);
1650 }
1651 
1652 /* console_lock is held */
1653 static void csi_M(struct vc_data *vc, unsigned int nr)
1654 {
1655 	if (nr > vc->vc_rows - vc->vc_y)
1656 		nr = vc->vc_rows - vc->vc_y;
1657 	else if (!nr)
1658 		nr=1;
1659 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_UP, nr);
1660 	vc->vc_need_wrap = 0;
1661 }
1662 
1663 /* console_lock is held (except via vc_init->reset_terminal */
1664 static void save_cur(struct vc_data *vc)
1665 {
1666 	vc->vc_saved_x		= vc->vc_x;
1667 	vc->vc_saved_y		= vc->vc_y;
1668 	vc->vc_s_intensity	= vc->vc_intensity;
1669 	vc->vc_s_italic         = vc->vc_italic;
1670 	vc->vc_s_underline	= vc->vc_underline;
1671 	vc->vc_s_blink		= vc->vc_blink;
1672 	vc->vc_s_reverse	= vc->vc_reverse;
1673 	vc->vc_s_charset	= vc->vc_charset;
1674 	vc->vc_s_color		= vc->vc_color;
1675 	vc->vc_saved_G0		= vc->vc_G0_charset;
1676 	vc->vc_saved_G1		= vc->vc_G1_charset;
1677 }
1678 
1679 /* console_lock is held */
1680 static void restore_cur(struct vc_data *vc)
1681 {
1682 	gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
1683 	vc->vc_intensity	= vc->vc_s_intensity;
1684 	vc->vc_italic		= vc->vc_s_italic;
1685 	vc->vc_underline	= vc->vc_s_underline;
1686 	vc->vc_blink		= vc->vc_s_blink;
1687 	vc->vc_reverse		= vc->vc_s_reverse;
1688 	vc->vc_charset		= vc->vc_s_charset;
1689 	vc->vc_color		= vc->vc_s_color;
1690 	vc->vc_G0_charset	= vc->vc_saved_G0;
1691 	vc->vc_G1_charset	= vc->vc_saved_G1;
1692 	vc->vc_translate	= set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
1693 	update_attr(vc);
1694 	vc->vc_need_wrap = 0;
1695 }
1696 
1697 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
1698 	EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
1699 	ESpalette, ESosc };
1700 
1701 /* console_lock is held (except via vc_init()) */
1702 static void reset_terminal(struct vc_data *vc, int do_clear)
1703 {
1704 	vc->vc_top		= 0;
1705 	vc->vc_bottom		= vc->vc_rows;
1706 	vc->vc_state		= ESnormal;
1707 	vc->vc_ques		= 0;
1708 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
1709 	vc->vc_G0_charset	= LAT1_MAP;
1710 	vc->vc_G1_charset	= GRAF_MAP;
1711 	vc->vc_charset		= 0;
1712 	vc->vc_need_wrap	= 0;
1713 	vc->vc_report_mouse	= 0;
1714 	vc->vc_utf              = default_utf8;
1715 	vc->vc_utf_count	= 0;
1716 
1717 	vc->vc_disp_ctrl	= 0;
1718 	vc->vc_toggle_meta	= 0;
1719 
1720 	vc->vc_decscnm		= 0;
1721 	vc->vc_decom		= 0;
1722 	vc->vc_decawm		= 1;
1723 	vc->vc_deccm		= global_cursor_default;
1724 	vc->vc_decim		= 0;
1725 
1726 	vt_reset_keyboard(vc->vc_num);
1727 
1728 	vc->vc_cursor_type = cur_default;
1729 	vc->vc_complement_mask = vc->vc_s_complement_mask;
1730 
1731 	default_attr(vc);
1732 	update_attr(vc);
1733 
1734 	vc->vc_tab_stop[0]	=
1735 	vc->vc_tab_stop[1]	=
1736 	vc->vc_tab_stop[2]	=
1737 	vc->vc_tab_stop[3]	=
1738 	vc->vc_tab_stop[4]	=
1739 	vc->vc_tab_stop[5]	=
1740 	vc->vc_tab_stop[6]	=
1741 	vc->vc_tab_stop[7]	= 0x01010101;
1742 
1743 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1744 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1745 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1746 
1747 	gotoxy(vc, 0, 0);
1748 	save_cur(vc);
1749 	if (do_clear)
1750 	    csi_J(vc, 2);
1751 }
1752 
1753 /* console_lock is held */
1754 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
1755 {
1756 	/*
1757 	 *  Control characters can be used in the _middle_
1758 	 *  of an escape sequence.
1759 	 */
1760 	if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
1761 		return;
1762 	switch (c) {
1763 	case 0:
1764 		return;
1765 	case 7:
1766 		if (vc->vc_state == ESosc)
1767 			vc->vc_state = ESnormal;
1768 		else if (vc->vc_bell_duration)
1769 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
1770 		return;
1771 	case 8:
1772 		bs(vc);
1773 		return;
1774 	case 9:
1775 		vc->vc_pos -= (vc->vc_x << 1);
1776 		while (vc->vc_x < vc->vc_cols - 1) {
1777 			vc->vc_x++;
1778 			if (vc->vc_tab_stop[7 & (vc->vc_x >> 5)] & (1 << (vc->vc_x & 31)))
1779 				break;
1780 		}
1781 		vc->vc_pos += (vc->vc_x << 1);
1782 		notify_write(vc, '\t');
1783 		return;
1784 	case 10: case 11: case 12:
1785 		lf(vc);
1786 		if (!is_kbd(vc, lnm))
1787 			return;
1788 	case 13:
1789 		cr(vc);
1790 		return;
1791 	case 14:
1792 		vc->vc_charset = 1;
1793 		vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
1794 		vc->vc_disp_ctrl = 1;
1795 		return;
1796 	case 15:
1797 		vc->vc_charset = 0;
1798 		vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
1799 		vc->vc_disp_ctrl = 0;
1800 		return;
1801 	case 24: case 26:
1802 		vc->vc_state = ESnormal;
1803 		return;
1804 	case 27:
1805 		vc->vc_state = ESesc;
1806 		return;
1807 	case 127:
1808 		del(vc);
1809 		return;
1810 	case 128+27:
1811 		vc->vc_state = ESsquare;
1812 		return;
1813 	}
1814 	switch(vc->vc_state) {
1815 	case ESesc:
1816 		vc->vc_state = ESnormal;
1817 		switch (c) {
1818 		case '[':
1819 			vc->vc_state = ESsquare;
1820 			return;
1821 		case ']':
1822 			vc->vc_state = ESnonstd;
1823 			return;
1824 		case '%':
1825 			vc->vc_state = ESpercent;
1826 			return;
1827 		case 'E':
1828 			cr(vc);
1829 			lf(vc);
1830 			return;
1831 		case 'M':
1832 			ri(vc);
1833 			return;
1834 		case 'D':
1835 			lf(vc);
1836 			return;
1837 		case 'H':
1838 			vc->vc_tab_stop[7 & (vc->vc_x >> 5)] |= (1 << (vc->vc_x & 31));
1839 			return;
1840 		case 'Z':
1841 			respond_ID(tty);
1842 			return;
1843 		case '7':
1844 			save_cur(vc);
1845 			return;
1846 		case '8':
1847 			restore_cur(vc);
1848 			return;
1849 		case '(':
1850 			vc->vc_state = ESsetG0;
1851 			return;
1852 		case ')':
1853 			vc->vc_state = ESsetG1;
1854 			return;
1855 		case '#':
1856 			vc->vc_state = EShash;
1857 			return;
1858 		case 'c':
1859 			reset_terminal(vc, 1);
1860 			return;
1861 		case '>':  /* Numeric keypad */
1862 			clr_kbd(vc, kbdapplic);
1863 			return;
1864 		case '=':  /* Appl. keypad */
1865 			set_kbd(vc, kbdapplic);
1866 			return;
1867 		}
1868 		return;
1869 	case ESnonstd:
1870 		if (c=='P') {   /* palette escape sequence */
1871 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1872 				vc->vc_par[vc->vc_npar] = 0;
1873 			vc->vc_npar = 0;
1874 			vc->vc_state = ESpalette;
1875 			return;
1876 		} else if (c=='R') {   /* reset palette */
1877 			reset_palette(vc);
1878 			vc->vc_state = ESnormal;
1879 		} else if (c>='0' && c<='9')
1880 			vc->vc_state = ESosc;
1881 		else
1882 			vc->vc_state = ESnormal;
1883 		return;
1884 	case ESpalette:
1885 		if (isxdigit(c)) {
1886 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
1887 			if (vc->vc_npar == 7) {
1888 				int i = vc->vc_par[0] * 3, j = 1;
1889 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1890 				vc->vc_palette[i++] += vc->vc_par[j++];
1891 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1892 				vc->vc_palette[i++] += vc->vc_par[j++];
1893 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1894 				vc->vc_palette[i] += vc->vc_par[j];
1895 				set_palette(vc);
1896 				vc->vc_state = ESnormal;
1897 			}
1898 		} else
1899 			vc->vc_state = ESnormal;
1900 		return;
1901 	case ESsquare:
1902 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1903 			vc->vc_par[vc->vc_npar] = 0;
1904 		vc->vc_npar = 0;
1905 		vc->vc_state = ESgetpars;
1906 		if (c == '[') { /* Function key */
1907 			vc->vc_state=ESfunckey;
1908 			return;
1909 		}
1910 		vc->vc_ques = (c == '?');
1911 		if (vc->vc_ques)
1912 			return;
1913 	case ESgetpars:
1914 		if (c == ';' && vc->vc_npar < NPAR - 1) {
1915 			vc->vc_npar++;
1916 			return;
1917 		} else if (c>='0' && c<='9') {
1918 			vc->vc_par[vc->vc_npar] *= 10;
1919 			vc->vc_par[vc->vc_npar] += c - '0';
1920 			return;
1921 		}
1922 		vc->vc_state = ESnormal;
1923 		switch(c) {
1924 		case 'h':
1925 			set_mode(vc, 1);
1926 			return;
1927 		case 'l':
1928 			set_mode(vc, 0);
1929 			return;
1930 		case 'c':
1931 			if (vc->vc_ques) {
1932 				if (vc->vc_par[0])
1933 					vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
1934 				else
1935 					vc->vc_cursor_type = cur_default;
1936 				return;
1937 			}
1938 			break;
1939 		case 'm':
1940 			if (vc->vc_ques) {
1941 				clear_selection();
1942 				if (vc->vc_par[0])
1943 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
1944 				else
1945 					vc->vc_complement_mask = vc->vc_s_complement_mask;
1946 				return;
1947 			}
1948 			break;
1949 		case 'n':
1950 			if (!vc->vc_ques) {
1951 				if (vc->vc_par[0] == 5)
1952 					status_report(tty);
1953 				else if (vc->vc_par[0] == 6)
1954 					cursor_report(vc, tty);
1955 			}
1956 			return;
1957 		}
1958 		if (vc->vc_ques) {
1959 			vc->vc_ques = 0;
1960 			return;
1961 		}
1962 		switch(c) {
1963 		case 'G': case '`':
1964 			if (vc->vc_par[0])
1965 				vc->vc_par[0]--;
1966 			gotoxy(vc, vc->vc_par[0], vc->vc_y);
1967 			return;
1968 		case 'A':
1969 			if (!vc->vc_par[0])
1970 				vc->vc_par[0]++;
1971 			gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
1972 			return;
1973 		case 'B': case 'e':
1974 			if (!vc->vc_par[0])
1975 				vc->vc_par[0]++;
1976 			gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
1977 			return;
1978 		case 'C': case 'a':
1979 			if (!vc->vc_par[0])
1980 				vc->vc_par[0]++;
1981 			gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
1982 			return;
1983 		case 'D':
1984 			if (!vc->vc_par[0])
1985 				vc->vc_par[0]++;
1986 			gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
1987 			return;
1988 		case 'E':
1989 			if (!vc->vc_par[0])
1990 				vc->vc_par[0]++;
1991 			gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
1992 			return;
1993 		case 'F':
1994 			if (!vc->vc_par[0])
1995 				vc->vc_par[0]++;
1996 			gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
1997 			return;
1998 		case 'd':
1999 			if (vc->vc_par[0])
2000 				vc->vc_par[0]--;
2001 			gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
2002 			return;
2003 		case 'H': case 'f':
2004 			if (vc->vc_par[0])
2005 				vc->vc_par[0]--;
2006 			if (vc->vc_par[1])
2007 				vc->vc_par[1]--;
2008 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2009 			return;
2010 		case 'J':
2011 			csi_J(vc, vc->vc_par[0]);
2012 			return;
2013 		case 'K':
2014 			csi_K(vc, vc->vc_par[0]);
2015 			return;
2016 		case 'L':
2017 			csi_L(vc, vc->vc_par[0]);
2018 			return;
2019 		case 'M':
2020 			csi_M(vc, vc->vc_par[0]);
2021 			return;
2022 		case 'P':
2023 			csi_P(vc, vc->vc_par[0]);
2024 			return;
2025 		case 'c':
2026 			if (!vc->vc_par[0])
2027 				respond_ID(tty);
2028 			return;
2029 		case 'g':
2030 			if (!vc->vc_par[0])
2031 				vc->vc_tab_stop[7 & (vc->vc_x >> 5)] &= ~(1 << (vc->vc_x & 31));
2032 			else if (vc->vc_par[0] == 3) {
2033 				vc->vc_tab_stop[0] =
2034 					vc->vc_tab_stop[1] =
2035 					vc->vc_tab_stop[2] =
2036 					vc->vc_tab_stop[3] =
2037 					vc->vc_tab_stop[4] =
2038 					vc->vc_tab_stop[5] =
2039 					vc->vc_tab_stop[6] =
2040 					vc->vc_tab_stop[7] = 0;
2041 			}
2042 			return;
2043 		case 'm':
2044 			csi_m(vc);
2045 			return;
2046 		case 'q': /* DECLL - but only 3 leds */
2047 			/* map 0,1,2,3 to 0,1,2,4 */
2048 			if (vc->vc_par[0] < 4)
2049 				vt_set_led_state(vc->vc_num,
2050 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2051 			return;
2052 		case 'r':
2053 			if (!vc->vc_par[0])
2054 				vc->vc_par[0]++;
2055 			if (!vc->vc_par[1])
2056 				vc->vc_par[1] = vc->vc_rows;
2057 			/* Minimum allowed region is 2 lines */
2058 			if (vc->vc_par[0] < vc->vc_par[1] &&
2059 			    vc->vc_par[1] <= vc->vc_rows) {
2060 				vc->vc_top = vc->vc_par[0] - 1;
2061 				vc->vc_bottom = vc->vc_par[1];
2062 				gotoxay(vc, 0, 0);
2063 			}
2064 			return;
2065 		case 's':
2066 			save_cur(vc);
2067 			return;
2068 		case 'u':
2069 			restore_cur(vc);
2070 			return;
2071 		case 'X':
2072 			csi_X(vc, vc->vc_par[0]);
2073 			return;
2074 		case '@':
2075 			csi_at(vc, vc->vc_par[0]);
2076 			return;
2077 		case ']': /* setterm functions */
2078 			setterm_command(vc);
2079 			return;
2080 		}
2081 		return;
2082 	case ESpercent:
2083 		vc->vc_state = ESnormal;
2084 		switch (c) {
2085 		case '@':  /* defined in ISO 2022 */
2086 			vc->vc_utf = 0;
2087 			return;
2088 		case 'G':  /* prelim official escape code */
2089 		case '8':  /* retained for compatibility */
2090 			vc->vc_utf = 1;
2091 			return;
2092 		}
2093 		return;
2094 	case ESfunckey:
2095 		vc->vc_state = ESnormal;
2096 		return;
2097 	case EShash:
2098 		vc->vc_state = ESnormal;
2099 		if (c == '8') {
2100 			/* DEC screen alignment test. kludge :-) */
2101 			vc->vc_video_erase_char =
2102 				(vc->vc_video_erase_char & 0xff00) | 'E';
2103 			csi_J(vc, 2);
2104 			vc->vc_video_erase_char =
2105 				(vc->vc_video_erase_char & 0xff00) | ' ';
2106 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2107 		}
2108 		return;
2109 	case ESsetG0:
2110 		if (c == '0')
2111 			vc->vc_G0_charset = GRAF_MAP;
2112 		else if (c == 'B')
2113 			vc->vc_G0_charset = LAT1_MAP;
2114 		else if (c == 'U')
2115 			vc->vc_G0_charset = IBMPC_MAP;
2116 		else if (c == 'K')
2117 			vc->vc_G0_charset = USER_MAP;
2118 		if (vc->vc_charset == 0)
2119 			vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2120 		vc->vc_state = ESnormal;
2121 		return;
2122 	case ESsetG1:
2123 		if (c == '0')
2124 			vc->vc_G1_charset = GRAF_MAP;
2125 		else if (c == 'B')
2126 			vc->vc_G1_charset = LAT1_MAP;
2127 		else if (c == 'U')
2128 			vc->vc_G1_charset = IBMPC_MAP;
2129 		else if (c == 'K')
2130 			vc->vc_G1_charset = USER_MAP;
2131 		if (vc->vc_charset == 1)
2132 			vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2133 		vc->vc_state = ESnormal;
2134 		return;
2135 	case ESosc:
2136 		return;
2137 	default:
2138 		vc->vc_state = ESnormal;
2139 	}
2140 }
2141 
2142 /* is_double_width() is based on the wcwidth() implementation by
2143  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2144  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2145  */
2146 struct interval {
2147 	uint32_t first;
2148 	uint32_t last;
2149 };
2150 
2151 static int ucs_cmp(const void *key, const void *elt)
2152 {
2153 	uint32_t ucs = *(uint32_t *)key;
2154 	struct interval e = *(struct interval *) elt;
2155 
2156 	if (ucs > e.last)
2157 		return 1;
2158 	else if (ucs < e.first)
2159 		return -1;
2160 	return 0;
2161 }
2162 
2163 static int is_double_width(uint32_t ucs)
2164 {
2165 	static const struct interval double_width[] = {
2166 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2167 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2168 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2169 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2170 	};
2171 	if (ucs < double_width[0].first ||
2172 	    ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2173 		return 0;
2174 
2175 	return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2176 			sizeof(struct interval), ucs_cmp) != NULL;
2177 }
2178 
2179 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2180 		unsigned long draw_to, int *draw_x)
2181 {
2182 	if (*draw_x < 0)
2183 		return;
2184 
2185 	vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2186 			(u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2187 	*draw_x = -1;
2188 }
2189 
2190 /* acquires console_lock */
2191 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2192 {
2193 	int c, tc, ok, n = 0, draw_x = -1;
2194 	unsigned int currcons;
2195 	unsigned long draw_from = 0, draw_to = 0;
2196 	struct vc_data *vc;
2197 	unsigned char vc_attr;
2198 	struct vt_notifier_param param;
2199 	uint8_t rescan;
2200 	uint8_t inverse;
2201 	uint8_t width;
2202 	u16 himask, charmask;
2203 
2204 	if (in_interrupt())
2205 		return count;
2206 
2207 	might_sleep();
2208 
2209 	console_lock();
2210 	vc = tty->driver_data;
2211 	if (vc == NULL) {
2212 		pr_err("vt: argh, driver_data is NULL !\n");
2213 		console_unlock();
2214 		return 0;
2215 	}
2216 
2217 	currcons = vc->vc_num;
2218 	if (!vc_cons_allocated(currcons)) {
2219 		/* could this happen? */
2220 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2221 		console_unlock();
2222 		return 0;
2223 	}
2224 
2225 	himask = vc->vc_hi_font_mask;
2226 	charmask = himask ? 0x1ff : 0xff;
2227 
2228 	/* undraw cursor first */
2229 	if (con_is_fg(vc))
2230 		hide_cursor(vc);
2231 
2232 	param.vc = vc;
2233 
2234 	while (!tty->stopped && count) {
2235 		int orig = *buf;
2236 		c = orig;
2237 		buf++;
2238 		n++;
2239 		count--;
2240 		rescan = 0;
2241 		inverse = 0;
2242 		width = 1;
2243 
2244 		/* Do no translation at all in control states */
2245 		if (vc->vc_state != ESnormal) {
2246 			tc = c;
2247 		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2248 		    /* Combine UTF-8 into Unicode in vc_utf_char.
2249 		     * vc_utf_count is the number of continuation bytes still
2250 		     * expected to arrive.
2251 		     * vc_npar is the number of continuation bytes arrived so
2252 		     * far
2253 		     */
2254 rescan_last_byte:
2255 		    if ((c & 0xc0) == 0x80) {
2256 			/* Continuation byte received */
2257 			static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2258 			if (vc->vc_utf_count) {
2259 			    vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2260 			    vc->vc_npar++;
2261 			    if (--vc->vc_utf_count) {
2262 				/* Still need some bytes */
2263 				continue;
2264 			    }
2265 			    /* Got a whole character */
2266 			    c = vc->vc_utf_char;
2267 			    /* Reject overlong sequences */
2268 			    if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2269 					c > utf8_length_changes[vc->vc_npar])
2270 				c = 0xfffd;
2271 			} else {
2272 			    /* Unexpected continuation byte */
2273 			    vc->vc_utf_count = 0;
2274 			    c = 0xfffd;
2275 			}
2276 		    } else {
2277 			/* Single ASCII byte or first byte of a sequence received */
2278 			if (vc->vc_utf_count) {
2279 			    /* Continuation byte expected */
2280 			    rescan = 1;
2281 			    vc->vc_utf_count = 0;
2282 			    c = 0xfffd;
2283 			} else if (c > 0x7f) {
2284 			    /* First byte of a multibyte sequence received */
2285 			    vc->vc_npar = 0;
2286 			    if ((c & 0xe0) == 0xc0) {
2287 				vc->vc_utf_count = 1;
2288 				vc->vc_utf_char = (c & 0x1f);
2289 			    } else if ((c & 0xf0) == 0xe0) {
2290 				vc->vc_utf_count = 2;
2291 				vc->vc_utf_char = (c & 0x0f);
2292 			    } else if ((c & 0xf8) == 0xf0) {
2293 				vc->vc_utf_count = 3;
2294 				vc->vc_utf_char = (c & 0x07);
2295 			    } else if ((c & 0xfc) == 0xf8) {
2296 				vc->vc_utf_count = 4;
2297 				vc->vc_utf_char = (c & 0x03);
2298 			    } else if ((c & 0xfe) == 0xfc) {
2299 				vc->vc_utf_count = 5;
2300 				vc->vc_utf_char = (c & 0x01);
2301 			    } else {
2302 				/* 254 and 255 are invalid */
2303 				c = 0xfffd;
2304 			    }
2305 			    if (vc->vc_utf_count) {
2306 				/* Still need some bytes */
2307 				continue;
2308 			    }
2309 			}
2310 			/* Nothing to do if an ASCII byte was received */
2311 		    }
2312 		    /* End of UTF-8 decoding. */
2313 		    /* c is the received character, or U+FFFD for invalid sequences. */
2314 		    /* Replace invalid Unicode code points with U+FFFD too */
2315 		    if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2316 			c = 0xfffd;
2317 		    tc = c;
2318 		} else {	/* no utf or alternate charset mode */
2319 		    tc = vc_translate(vc, c);
2320 		}
2321 
2322 		param.c = tc;
2323 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2324 					&param) == NOTIFY_STOP)
2325 			continue;
2326 
2327                 /* If the original code was a control character we
2328                  * only allow a glyph to be displayed if the code is
2329                  * not normally used (such as for cursor movement) or
2330                  * if the disp_ctrl mode has been explicitly enabled.
2331                  * Certain characters (as given by the CTRL_ALWAYS
2332                  * bitmap) are always displayed as control characters,
2333                  * as the console would be pretty useless without
2334                  * them; to display an arbitrary font position use the
2335                  * direct-to-font zone in UTF-8 mode.
2336                  */
2337                 ok = tc && (c >= 32 ||
2338 			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2339 				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2340 			&& (c != 127 || vc->vc_disp_ctrl)
2341 			&& (c != 128+27);
2342 
2343 		if (vc->vc_state == ESnormal && ok) {
2344 			if (vc->vc_utf && !vc->vc_disp_ctrl) {
2345 				if (is_double_width(c))
2346 					width = 2;
2347 			}
2348 			/* Now try to find out how to display it */
2349 			tc = conv_uni_to_pc(vc, tc);
2350 			if (tc & ~charmask) {
2351 				if (tc == -1 || tc == -2) {
2352 				    continue; /* nothing to display */
2353 				}
2354 				/* Glyph not found */
2355 				if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2356 				    /* In legacy mode use the glyph we get by a 1:1 mapping.
2357 				       This would make absolutely no sense with Unicode in mind,
2358 				       but do this for ASCII characters since a font may lack
2359 				       Unicode mapping info and we don't want to end up with
2360 				       having question marks only. */
2361 				    tc = c;
2362 				} else {
2363 				    /* Display U+FFFD. If it's not found, display an inverse question mark. */
2364 				    tc = conv_uni_to_pc(vc, 0xfffd);
2365 				    if (tc < 0) {
2366 					inverse = 1;
2367 					tc = conv_uni_to_pc(vc, '?');
2368 					if (tc < 0) tc = '?';
2369 				    }
2370 				}
2371 			}
2372 
2373 			if (!inverse) {
2374 				vc_attr = vc->vc_attr;
2375 			} else {
2376 				/* invert vc_attr */
2377 				if (!vc->vc_can_do_color) {
2378 					vc_attr = (vc->vc_attr) ^ 0x08;
2379 				} else if (vc->vc_hi_font_mask == 0x100) {
2380 					vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2381 				} else {
2382 					vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2383 				}
2384 				con_flush(vc, draw_from, draw_to, &draw_x);
2385 			}
2386 
2387 			while (1) {
2388 				if (vc->vc_need_wrap || vc->vc_decim)
2389 					con_flush(vc, draw_from, draw_to,
2390 							&draw_x);
2391 				if (vc->vc_need_wrap) {
2392 					cr(vc);
2393 					lf(vc);
2394 				}
2395 				if (vc->vc_decim)
2396 					insert_char(vc, 1);
2397 				scr_writew(himask ?
2398 					     ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2399 					     (vc_attr << 8) + tc,
2400 					   (u16 *) vc->vc_pos);
2401 				if (con_should_update(vc) && draw_x < 0) {
2402 					draw_x = vc->vc_x;
2403 					draw_from = vc->vc_pos;
2404 				}
2405 				if (vc->vc_x == vc->vc_cols - 1) {
2406 					vc->vc_need_wrap = vc->vc_decawm;
2407 					draw_to = vc->vc_pos + 2;
2408 				} else {
2409 					vc->vc_x++;
2410 					draw_to = (vc->vc_pos += 2);
2411 				}
2412 
2413 				if (!--width) break;
2414 
2415 				tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2416 				if (tc < 0) tc = ' ';
2417 			}
2418 			notify_write(vc, c);
2419 
2420 			if (inverse)
2421 				con_flush(vc, draw_from, draw_to, &draw_x);
2422 
2423 			if (rescan) {
2424 				rescan = 0;
2425 				inverse = 0;
2426 				width = 1;
2427 				c = orig;
2428 				goto rescan_last_byte;
2429 			}
2430 			continue;
2431 		}
2432 		con_flush(vc, draw_from, draw_to, &draw_x);
2433 		do_con_trol(tty, vc, orig);
2434 	}
2435 	con_flush(vc, draw_from, draw_to, &draw_x);
2436 	console_conditional_schedule();
2437 	console_unlock();
2438 	notify_update(vc);
2439 	return n;
2440 }
2441 
2442 /*
2443  * This is the console switching callback.
2444  *
2445  * Doing console switching in a process context allows
2446  * us to do the switches asynchronously (needed when we want
2447  * to switch due to a keyboard interrupt).  Synchronization
2448  * with other console code and prevention of re-entrancy is
2449  * ensured with console_lock.
2450  */
2451 static void console_callback(struct work_struct *ignored)
2452 {
2453 	console_lock();
2454 
2455 	if (want_console >= 0) {
2456 		if (want_console != fg_console &&
2457 		    vc_cons_allocated(want_console)) {
2458 			hide_cursor(vc_cons[fg_console].d);
2459 			change_console(vc_cons[want_console].d);
2460 			/* we only changed when the console had already
2461 			   been allocated - a new console is not created
2462 			   in an interrupt routine */
2463 		}
2464 		want_console = -1;
2465 	}
2466 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2467 		do_poke_blanked_console = 0;
2468 		poke_blanked_console();
2469 	}
2470 	if (scrollback_delta) {
2471 		struct vc_data *vc = vc_cons[fg_console].d;
2472 		clear_selection();
2473 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2474 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2475 		scrollback_delta = 0;
2476 	}
2477 	if (blank_timer_expired) {
2478 		do_blank_screen(0);
2479 		blank_timer_expired = 0;
2480 	}
2481 	notify_update(vc_cons[fg_console].d);
2482 
2483 	console_unlock();
2484 }
2485 
2486 int set_console(int nr)
2487 {
2488 	struct vc_data *vc = vc_cons[fg_console].d;
2489 
2490 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
2491 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2492 
2493 		/*
2494 		 * Console switch will fail in console_callback() or
2495 		 * change_console() so there is no point scheduling
2496 		 * the callback
2497 		 *
2498 		 * Existing set_console() users don't check the return
2499 		 * value so this shouldn't break anything
2500 		 */
2501 		return -EINVAL;
2502 	}
2503 
2504 	want_console = nr;
2505 	schedule_console_callback();
2506 
2507 	return 0;
2508 }
2509 
2510 struct tty_driver *console_driver;
2511 
2512 #ifdef CONFIG_VT_CONSOLE
2513 
2514 /**
2515  * vt_kmsg_redirect() - Sets/gets the kernel message console
2516  * @new:	The new virtual terminal number or -1 if the console should stay
2517  * 		unchanged
2518  *
2519  * By default, the kernel messages are always printed on the current virtual
2520  * console. However, the user may modify that default with the
2521  * TIOCL_SETKMSGREDIRECT ioctl call.
2522  *
2523  * This function sets the kernel message console to be @new. It returns the old
2524  * virtual console number. The virtual terminal number 0 (both as parameter and
2525  * return value) means no redirection (i.e. always printed on the currently
2526  * active console).
2527  *
2528  * The parameter -1 means that only the current console is returned, but the
2529  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2530  * case to make the code more understandable.
2531  *
2532  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2533  * the parameter and always returns 0.
2534  */
2535 int vt_kmsg_redirect(int new)
2536 {
2537 	static int kmsg_con;
2538 
2539 	if (new != -1)
2540 		return xchg(&kmsg_con, new);
2541 	else
2542 		return kmsg_con;
2543 }
2544 
2545 /*
2546  *	Console on virtual terminal
2547  *
2548  * The console must be locked when we get here.
2549  */
2550 
2551 static void vt_console_print(struct console *co, const char *b, unsigned count)
2552 {
2553 	struct vc_data *vc = vc_cons[fg_console].d;
2554 	unsigned char c;
2555 	static DEFINE_SPINLOCK(printing_lock);
2556 	const ushort *start;
2557 	ushort cnt = 0;
2558 	ushort myx;
2559 	int kmsg_console;
2560 
2561 	/* console busy or not yet initialized */
2562 	if (!printable)
2563 		return;
2564 	if (!spin_trylock(&printing_lock))
2565 		return;
2566 
2567 	kmsg_console = vt_get_kmsg_redirect();
2568 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2569 		vc = vc_cons[kmsg_console - 1].d;
2570 
2571 	/* read `x' only after setting currcons properly (otherwise
2572 	   the `x' macro will read the x of the foreground console). */
2573 	myx = vc->vc_x;
2574 
2575 	if (!vc_cons_allocated(fg_console)) {
2576 		/* impossible */
2577 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2578 		goto quit;
2579 	}
2580 
2581 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
2582 		goto quit;
2583 
2584 	/* undraw cursor first */
2585 	if (con_is_fg(vc))
2586 		hide_cursor(vc);
2587 
2588 	start = (ushort *)vc->vc_pos;
2589 
2590 	/* Contrived structure to try to emulate original need_wrap behaviour
2591 	 * Problems caused when we have need_wrap set on '\n' character */
2592 	while (count--) {
2593 		c = *b++;
2594 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2595 			if (cnt > 0) {
2596 				if (con_is_visible(vc))
2597 					vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2598 				vc->vc_x += cnt;
2599 				if (vc->vc_need_wrap)
2600 					vc->vc_x--;
2601 				cnt = 0;
2602 			}
2603 			if (c == 8) {		/* backspace */
2604 				bs(vc);
2605 				start = (ushort *)vc->vc_pos;
2606 				myx = vc->vc_x;
2607 				continue;
2608 			}
2609 			if (c != 13)
2610 				lf(vc);
2611 			cr(vc);
2612 			start = (ushort *)vc->vc_pos;
2613 			myx = vc->vc_x;
2614 			if (c == 10 || c == 13)
2615 				continue;
2616 		}
2617 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2618 		notify_write(vc, c);
2619 		cnt++;
2620 		if (myx == vc->vc_cols - 1) {
2621 			vc->vc_need_wrap = 1;
2622 			continue;
2623 		}
2624 		vc->vc_pos += 2;
2625 		myx++;
2626 	}
2627 	if (cnt > 0) {
2628 		if (con_is_visible(vc))
2629 			vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2630 		vc->vc_x += cnt;
2631 		if (vc->vc_x == vc->vc_cols) {
2632 			vc->vc_x--;
2633 			vc->vc_need_wrap = 1;
2634 		}
2635 	}
2636 	set_cursor(vc);
2637 	notify_update(vc);
2638 
2639 quit:
2640 	spin_unlock(&printing_lock);
2641 }
2642 
2643 static struct tty_driver *vt_console_device(struct console *c, int *index)
2644 {
2645 	*index = c->index ? c->index-1 : fg_console;
2646 	return console_driver;
2647 }
2648 
2649 static struct console vt_console_driver = {
2650 	.name		= "tty",
2651 	.write		= vt_console_print,
2652 	.device		= vt_console_device,
2653 	.unblank	= unblank_screen,
2654 	.flags		= CON_PRINTBUFFER,
2655 	.index		= -1,
2656 };
2657 #endif
2658 
2659 /*
2660  *	Handling of Linux-specific VC ioctls
2661  */
2662 
2663 /*
2664  * Generally a bit racy with respect to console_lock();.
2665  *
2666  * There are some functions which don't need it.
2667  *
2668  * There are some functions which can sleep for arbitrary periods
2669  * (paste_selection) but we don't need the lock there anyway.
2670  *
2671  * set_selection has locking, and definitely needs it
2672  */
2673 
2674 int tioclinux(struct tty_struct *tty, unsigned long arg)
2675 {
2676 	char type, data;
2677 	char __user *p = (char __user *)arg;
2678 	int lines;
2679 	int ret;
2680 
2681 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
2682 		return -EPERM;
2683 	if (get_user(type, p))
2684 		return -EFAULT;
2685 	ret = 0;
2686 
2687 	switch (type)
2688 	{
2689 		case TIOCL_SETSEL:
2690 			console_lock();
2691 			ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
2692 			console_unlock();
2693 			break;
2694 		case TIOCL_PASTESEL:
2695 			ret = paste_selection(tty);
2696 			break;
2697 		case TIOCL_UNBLANKSCREEN:
2698 			console_lock();
2699 			unblank_screen();
2700 			console_unlock();
2701 			break;
2702 		case TIOCL_SELLOADLUT:
2703 			console_lock();
2704 			ret = sel_loadlut(p);
2705 			console_unlock();
2706 			break;
2707 		case TIOCL_GETSHIFTSTATE:
2708 
2709 	/*
2710 	 * Make it possible to react to Shift+Mousebutton.
2711 	 * Note that 'shift_state' is an undocumented
2712 	 * kernel-internal variable; programs not closely
2713 	 * related to the kernel should not use this.
2714 	 */
2715 			data = vt_get_shift_state();
2716 			ret = put_user(data, p);
2717 			break;
2718 		case TIOCL_GETMOUSEREPORTING:
2719 			console_lock();	/* May be overkill */
2720 			data = mouse_reporting();
2721 			console_unlock();
2722 			ret = put_user(data, p);
2723 			break;
2724 		case TIOCL_SETVESABLANK:
2725 			console_lock();
2726 			ret = set_vesa_blanking(p);
2727 			console_unlock();
2728 			break;
2729 		case TIOCL_GETKMSGREDIRECT:
2730 			data = vt_get_kmsg_redirect();
2731 			ret = put_user(data, p);
2732 			break;
2733 		case TIOCL_SETKMSGREDIRECT:
2734 			if (!capable(CAP_SYS_ADMIN)) {
2735 				ret = -EPERM;
2736 			} else {
2737 				if (get_user(data, p+1))
2738 					ret = -EFAULT;
2739 				else
2740 					vt_kmsg_redirect(data);
2741 			}
2742 			break;
2743 		case TIOCL_GETFGCONSOLE:
2744 			/* No locking needed as this is a transiently
2745 			   correct return anyway if the caller hasn't
2746 			   disabled switching */
2747 			ret = fg_console;
2748 			break;
2749 		case TIOCL_SCROLLCONSOLE:
2750 			if (get_user(lines, (s32 __user *)(p+4))) {
2751 				ret = -EFAULT;
2752 			} else {
2753 				/* Need the console lock here. Note that lots
2754 				   of other calls need fixing before the lock
2755 				   is actually useful ! */
2756 				console_lock();
2757 				scrollfront(vc_cons[fg_console].d, lines);
2758 				console_unlock();
2759 				ret = 0;
2760 			}
2761 			break;
2762 		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
2763 			console_lock();
2764 			ignore_poke = 1;
2765 			do_blank_screen(0);
2766 			console_unlock();
2767 			break;
2768 		case TIOCL_BLANKEDSCREEN:
2769 			ret = console_blanked;
2770 			break;
2771 		default:
2772 			ret = -EINVAL;
2773 			break;
2774 	}
2775 	return ret;
2776 }
2777 
2778 /*
2779  * /dev/ttyN handling
2780  */
2781 
2782 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2783 {
2784 	int	retval;
2785 
2786 	retval = do_con_write(tty, buf, count);
2787 	con_flush_chars(tty);
2788 
2789 	return retval;
2790 }
2791 
2792 static int con_put_char(struct tty_struct *tty, unsigned char ch)
2793 {
2794 	if (in_interrupt())
2795 		return 0;	/* n_r3964 calls put_char() from interrupt context */
2796 	return do_con_write(tty, &ch, 1);
2797 }
2798 
2799 static int con_write_room(struct tty_struct *tty)
2800 {
2801 	if (tty->stopped)
2802 		return 0;
2803 	return 32768;		/* No limit, really; we're not buffering */
2804 }
2805 
2806 static int con_chars_in_buffer(struct tty_struct *tty)
2807 {
2808 	return 0;		/* we're not buffering */
2809 }
2810 
2811 /*
2812  * con_throttle and con_unthrottle are only used for
2813  * paste_selection(), which has to stuff in a large number of
2814  * characters...
2815  */
2816 static void con_throttle(struct tty_struct *tty)
2817 {
2818 }
2819 
2820 static void con_unthrottle(struct tty_struct *tty)
2821 {
2822 	struct vc_data *vc = tty->driver_data;
2823 
2824 	wake_up_interruptible(&vc->paste_wait);
2825 }
2826 
2827 /*
2828  * Turn the Scroll-Lock LED on when the tty is stopped
2829  */
2830 static void con_stop(struct tty_struct *tty)
2831 {
2832 	int console_num;
2833 	if (!tty)
2834 		return;
2835 	console_num = tty->index;
2836 	if (!vc_cons_allocated(console_num))
2837 		return;
2838 	vt_kbd_con_stop(console_num);
2839 }
2840 
2841 /*
2842  * Turn the Scroll-Lock LED off when the console is started
2843  */
2844 static void con_start(struct tty_struct *tty)
2845 {
2846 	int console_num;
2847 	if (!tty)
2848 		return;
2849 	console_num = tty->index;
2850 	if (!vc_cons_allocated(console_num))
2851 		return;
2852 	vt_kbd_con_start(console_num);
2853 }
2854 
2855 static void con_flush_chars(struct tty_struct *tty)
2856 {
2857 	struct vc_data *vc;
2858 
2859 	if (in_interrupt())	/* from flush_to_ldisc */
2860 		return;
2861 
2862 	/* if we race with con_close(), vt may be null */
2863 	console_lock();
2864 	vc = tty->driver_data;
2865 	if (vc)
2866 		set_cursor(vc);
2867 	console_unlock();
2868 }
2869 
2870 /*
2871  * Allocate the console screen memory.
2872  */
2873 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
2874 {
2875 	unsigned int currcons = tty->index;
2876 	struct vc_data *vc;
2877 	int ret;
2878 
2879 	console_lock();
2880 	ret = vc_allocate(currcons);
2881 	if (ret)
2882 		goto unlock;
2883 
2884 	vc = vc_cons[currcons].d;
2885 
2886 	/* Still being freed */
2887 	if (vc->port.tty) {
2888 		ret = -ERESTARTSYS;
2889 		goto unlock;
2890 	}
2891 
2892 	ret = tty_port_install(&vc->port, driver, tty);
2893 	if (ret)
2894 		goto unlock;
2895 
2896 	tty->driver_data = vc;
2897 	vc->port.tty = tty;
2898 
2899 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
2900 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
2901 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
2902 	}
2903 	if (vc->vc_utf)
2904 		tty->termios.c_iflag |= IUTF8;
2905 	else
2906 		tty->termios.c_iflag &= ~IUTF8;
2907 unlock:
2908 	console_unlock();
2909 	return ret;
2910 }
2911 
2912 static int con_open(struct tty_struct *tty, struct file *filp)
2913 {
2914 	/* everything done in install */
2915 	return 0;
2916 }
2917 
2918 
2919 static void con_close(struct tty_struct *tty, struct file *filp)
2920 {
2921 	/* Nothing to do - we defer to shutdown */
2922 }
2923 
2924 static void con_shutdown(struct tty_struct *tty)
2925 {
2926 	struct vc_data *vc = tty->driver_data;
2927 	BUG_ON(vc == NULL);
2928 	console_lock();
2929 	vc->port.tty = NULL;
2930 	console_unlock();
2931 }
2932 
2933 static int default_color           = 7; /* white */
2934 static int default_italic_color    = 2; // green (ASCII)
2935 static int default_underline_color = 3; // cyan (ASCII)
2936 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
2937 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
2938 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
2939 
2940 static void vc_init(struct vc_data *vc, unsigned int rows,
2941 		    unsigned int cols, int do_clear)
2942 {
2943 	int j, k ;
2944 
2945 	vc->vc_cols = cols;
2946 	vc->vc_rows = rows;
2947 	vc->vc_size_row = cols << 1;
2948 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
2949 
2950 	set_origin(vc);
2951 	vc->vc_pos = vc->vc_origin;
2952 	reset_vc(vc);
2953 	for (j=k=0; j<16; j++) {
2954 		vc->vc_palette[k++] = default_red[j] ;
2955 		vc->vc_palette[k++] = default_grn[j] ;
2956 		vc->vc_palette[k++] = default_blu[j] ;
2957 	}
2958 	vc->vc_def_color       = default_color;
2959 	vc->vc_ulcolor         = default_underline_color;
2960 	vc->vc_itcolor         = default_italic_color;
2961 	vc->vc_halfcolor       = 0x08;   /* grey */
2962 	init_waitqueue_head(&vc->paste_wait);
2963 	reset_terminal(vc, do_clear);
2964 }
2965 
2966 /*
2967  * This routine initializes console interrupts, and does nothing
2968  * else. If you want the screen to clear, call tty_write with
2969  * the appropriate escape-sequence.
2970  */
2971 
2972 static int __init con_init(void)
2973 {
2974 	const char *display_desc = NULL;
2975 	struct vc_data *vc;
2976 	unsigned int currcons = 0, i;
2977 
2978 	console_lock();
2979 
2980 	if (conswitchp)
2981 		display_desc = conswitchp->con_startup();
2982 	if (!display_desc) {
2983 		fg_console = 0;
2984 		console_unlock();
2985 		return 0;
2986 	}
2987 
2988 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
2989 		struct con_driver *con_driver = &registered_con_driver[i];
2990 
2991 		if (con_driver->con == NULL) {
2992 			con_driver->con = conswitchp;
2993 			con_driver->desc = display_desc;
2994 			con_driver->flag = CON_DRIVER_FLAG_INIT;
2995 			con_driver->first = 0;
2996 			con_driver->last = MAX_NR_CONSOLES - 1;
2997 			break;
2998 		}
2999 	}
3000 
3001 	for (i = 0; i < MAX_NR_CONSOLES; i++)
3002 		con_driver_map[i] = conswitchp;
3003 
3004 	if (blankinterval) {
3005 		blank_state = blank_normal_wait;
3006 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3007 	}
3008 
3009 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3010 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3011 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3012 		tty_port_init(&vc->port);
3013 		visual_init(vc, currcons, 1);
3014 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3015 		vc_init(vc, vc->vc_rows, vc->vc_cols,
3016 			currcons || !vc->vc_sw->con_save_screen);
3017 	}
3018 	currcons = fg_console = 0;
3019 	master_display_fg = vc = vc_cons[currcons].d;
3020 	set_origin(vc);
3021 	save_screen(vc);
3022 	gotoxy(vc, vc->vc_x, vc->vc_y);
3023 	csi_J(vc, 0);
3024 	update_screen(vc);
3025 	pr_info("Console: %s %s %dx%d\n",
3026 		vc->vc_can_do_color ? "colour" : "mono",
3027 		display_desc, vc->vc_cols, vc->vc_rows);
3028 	printable = 1;
3029 
3030 	console_unlock();
3031 
3032 #ifdef CONFIG_VT_CONSOLE
3033 	register_console(&vt_console_driver);
3034 #endif
3035 	return 0;
3036 }
3037 console_initcall(con_init);
3038 
3039 static const struct tty_operations con_ops = {
3040 	.install = con_install,
3041 	.open = con_open,
3042 	.close = con_close,
3043 	.write = con_write,
3044 	.write_room = con_write_room,
3045 	.put_char = con_put_char,
3046 	.flush_chars = con_flush_chars,
3047 	.chars_in_buffer = con_chars_in_buffer,
3048 	.ioctl = vt_ioctl,
3049 #ifdef CONFIG_COMPAT
3050 	.compat_ioctl = vt_compat_ioctl,
3051 #endif
3052 	.stop = con_stop,
3053 	.start = con_start,
3054 	.throttle = con_throttle,
3055 	.unthrottle = con_unthrottle,
3056 	.resize = vt_resize,
3057 	.shutdown = con_shutdown
3058 };
3059 
3060 static struct cdev vc0_cdev;
3061 
3062 static ssize_t show_tty_active(struct device *dev,
3063 				struct device_attribute *attr, char *buf)
3064 {
3065 	return sprintf(buf, "tty%d\n", fg_console + 1);
3066 }
3067 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3068 
3069 static struct attribute *vt_dev_attrs[] = {
3070 	&dev_attr_active.attr,
3071 	NULL
3072 };
3073 
3074 ATTRIBUTE_GROUPS(vt_dev);
3075 
3076 int __init vty_init(const struct file_operations *console_fops)
3077 {
3078 	cdev_init(&vc0_cdev, console_fops);
3079 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3080 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3081 		panic("Couldn't register /dev/tty0 driver\n");
3082 	tty0dev = device_create_with_groups(tty_class, NULL,
3083 					    MKDEV(TTY_MAJOR, 0), NULL,
3084 					    vt_dev_groups, "tty0");
3085 	if (IS_ERR(tty0dev))
3086 		tty0dev = NULL;
3087 
3088 	vcs_init();
3089 
3090 	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3091 	if (!console_driver)
3092 		panic("Couldn't allocate console driver\n");
3093 
3094 	console_driver->name = "tty";
3095 	console_driver->name_base = 1;
3096 	console_driver->major = TTY_MAJOR;
3097 	console_driver->minor_start = 1;
3098 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3099 	console_driver->init_termios = tty_std_termios;
3100 	if (default_utf8)
3101 		console_driver->init_termios.c_iflag |= IUTF8;
3102 	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3103 	tty_set_operations(console_driver, &con_ops);
3104 	if (tty_register_driver(console_driver))
3105 		panic("Couldn't register console driver\n");
3106 	kbd_init();
3107 	console_map_init();
3108 #ifdef CONFIG_MDA_CONSOLE
3109 	mda_console_init();
3110 #endif
3111 	return 0;
3112 }
3113 
3114 #ifndef VT_SINGLE_DRIVER
3115 
3116 static struct class *vtconsole_class;
3117 
3118 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3119 			   int deflt)
3120 {
3121 	struct module *owner = csw->owner;
3122 	const char *desc = NULL;
3123 	struct con_driver *con_driver;
3124 	int i, j = -1, k = -1, retval = -ENODEV;
3125 
3126 	if (!try_module_get(owner))
3127 		return -ENODEV;
3128 
3129 	WARN_CONSOLE_UNLOCKED();
3130 
3131 	/* check if driver is registered */
3132 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3133 		con_driver = &registered_con_driver[i];
3134 
3135 		if (con_driver->con == csw) {
3136 			desc = con_driver->desc;
3137 			retval = 0;
3138 			break;
3139 		}
3140 	}
3141 
3142 	if (retval)
3143 		goto err;
3144 
3145 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3146 		csw->con_startup();
3147 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3148 	}
3149 
3150 	if (deflt) {
3151 		if (conswitchp)
3152 			module_put(conswitchp->owner);
3153 
3154 		__module_get(owner);
3155 		conswitchp = csw;
3156 	}
3157 
3158 	first = max(first, con_driver->first);
3159 	last = min(last, con_driver->last);
3160 
3161 	for (i = first; i <= last; i++) {
3162 		int old_was_color;
3163 		struct vc_data *vc = vc_cons[i].d;
3164 
3165 		if (con_driver_map[i])
3166 			module_put(con_driver_map[i]->owner);
3167 		__module_get(owner);
3168 		con_driver_map[i] = csw;
3169 
3170 		if (!vc || !vc->vc_sw)
3171 			continue;
3172 
3173 		j = i;
3174 
3175 		if (con_is_visible(vc)) {
3176 			k = i;
3177 			save_screen(vc);
3178 		}
3179 
3180 		old_was_color = vc->vc_can_do_color;
3181 		vc->vc_sw->con_deinit(vc);
3182 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3183 		visual_init(vc, i, 0);
3184 		set_origin(vc);
3185 		update_attr(vc);
3186 
3187 		/* If the console changed between mono <-> color, then
3188 		 * the attributes in the screenbuf will be wrong.  The
3189 		 * following resets all attributes to something sane.
3190 		 */
3191 		if (old_was_color != vc->vc_can_do_color)
3192 			clear_buffer_attributes(vc);
3193 	}
3194 
3195 	pr_info("Console: switching ");
3196 	if (!deflt)
3197 		pr_cont("consoles %d-%d ", first + 1, last + 1);
3198 	if (j >= 0) {
3199 		struct vc_data *vc = vc_cons[j].d;
3200 
3201 		pr_cont("to %s %s %dx%d\n",
3202 			vc->vc_can_do_color ? "colour" : "mono",
3203 			desc, vc->vc_cols, vc->vc_rows);
3204 
3205 		if (k >= 0) {
3206 			vc = vc_cons[k].d;
3207 			update_screen(vc);
3208 		}
3209 	} else {
3210 		pr_cont("to %s\n", desc);
3211 	}
3212 
3213 	retval = 0;
3214 err:
3215 	module_put(owner);
3216 	return retval;
3217 };
3218 
3219 
3220 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3221 /* unlocked version of unbind_con_driver() */
3222 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3223 {
3224 	struct module *owner = csw->owner;
3225 	const struct consw *defcsw = NULL;
3226 	struct con_driver *con_driver = NULL, *con_back = NULL;
3227 	int i, retval = -ENODEV;
3228 
3229 	if (!try_module_get(owner))
3230 		return -ENODEV;
3231 
3232 	WARN_CONSOLE_UNLOCKED();
3233 
3234 	/* check if driver is registered and if it is unbindable */
3235 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3236 		con_driver = &registered_con_driver[i];
3237 
3238 		if (con_driver->con == csw &&
3239 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3240 			retval = 0;
3241 			break;
3242 		}
3243 	}
3244 
3245 	if (retval)
3246 		goto err;
3247 
3248 	retval = -ENODEV;
3249 
3250 	/* check if backup driver exists */
3251 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3252 		con_back = &registered_con_driver[i];
3253 
3254 		if (con_back->con && con_back->con != csw) {
3255 			defcsw = con_back->con;
3256 			retval = 0;
3257 			break;
3258 		}
3259 	}
3260 
3261 	if (retval)
3262 		goto err;
3263 
3264 	if (!con_is_bound(csw))
3265 		goto err;
3266 
3267 	first = max(first, con_driver->first);
3268 	last = min(last, con_driver->last);
3269 
3270 	for (i = first; i <= last; i++) {
3271 		if (con_driver_map[i] == csw) {
3272 			module_put(csw->owner);
3273 			con_driver_map[i] = NULL;
3274 		}
3275 	}
3276 
3277 	if (!con_is_bound(defcsw)) {
3278 		const struct consw *defconsw = conswitchp;
3279 
3280 		defcsw->con_startup();
3281 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3282 		/*
3283 		 * vgacon may change the default driver to point
3284 		 * to dummycon, we restore it here...
3285 		 */
3286 		conswitchp = defconsw;
3287 	}
3288 
3289 	if (!con_is_bound(csw))
3290 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3291 
3292 	/* ignore return value, binding should not fail */
3293 	do_bind_con_driver(defcsw, first, last, deflt);
3294 err:
3295 	module_put(owner);
3296 	return retval;
3297 
3298 }
3299 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3300 
3301 static int vt_bind(struct con_driver *con)
3302 {
3303 	const struct consw *defcsw = NULL, *csw = NULL;
3304 	int i, more = 1, first = -1, last = -1, deflt = 0;
3305 
3306  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3307 		goto err;
3308 
3309 	csw = con->con;
3310 
3311 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3312 		struct con_driver *con = &registered_con_driver[i];
3313 
3314 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3315 			defcsw = con->con;
3316 			break;
3317 		}
3318 	}
3319 
3320 	if (!defcsw)
3321 		goto err;
3322 
3323 	while (more) {
3324 		more = 0;
3325 
3326 		for (i = con->first; i <= con->last; i++) {
3327 			if (con_driver_map[i] == defcsw) {
3328 				if (first == -1)
3329 					first = i;
3330 				last = i;
3331 				more = 1;
3332 			} else if (first != -1)
3333 				break;
3334 		}
3335 
3336 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3337 			deflt = 1;
3338 
3339 		if (first != -1)
3340 			do_bind_con_driver(csw, first, last, deflt);
3341 
3342 		first = -1;
3343 		last = -1;
3344 		deflt = 0;
3345 	}
3346 
3347 err:
3348 	return 0;
3349 }
3350 
3351 static int vt_unbind(struct con_driver *con)
3352 {
3353 	const struct consw *csw = NULL;
3354 	int i, more = 1, first = -1, last = -1, deflt = 0;
3355 	int ret;
3356 
3357  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3358 		goto err;
3359 
3360 	csw = con->con;
3361 
3362 	while (more) {
3363 		more = 0;
3364 
3365 		for (i = con->first; i <= con->last; i++) {
3366 			if (con_driver_map[i] == csw) {
3367 				if (first == -1)
3368 					first = i;
3369 				last = i;
3370 				more = 1;
3371 			} else if (first != -1)
3372 				break;
3373 		}
3374 
3375 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3376 			deflt = 1;
3377 
3378 		if (first != -1) {
3379 			ret = do_unbind_con_driver(csw, first, last, deflt);
3380 			if (ret != 0)
3381 				return ret;
3382 		}
3383 
3384 		first = -1;
3385 		last = -1;
3386 		deflt = 0;
3387 	}
3388 
3389 err:
3390 	return 0;
3391 }
3392 #else
3393 static inline int vt_bind(struct con_driver *con)
3394 {
3395 	return 0;
3396 }
3397 static inline int vt_unbind(struct con_driver *con)
3398 {
3399 	return 0;
3400 }
3401 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3402 
3403 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3404 			  const char *buf, size_t count)
3405 {
3406 	struct con_driver *con = dev_get_drvdata(dev);
3407 	int bind = simple_strtoul(buf, NULL, 0);
3408 
3409 	console_lock();
3410 
3411 	if (bind)
3412 		vt_bind(con);
3413 	else
3414 		vt_unbind(con);
3415 
3416 	console_unlock();
3417 
3418 	return count;
3419 }
3420 
3421 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3422 			 char *buf)
3423 {
3424 	struct con_driver *con = dev_get_drvdata(dev);
3425 	int bind = con_is_bound(con->con);
3426 
3427 	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3428 }
3429 
3430 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3431 			 char *buf)
3432 {
3433 	struct con_driver *con = dev_get_drvdata(dev);
3434 
3435 	return snprintf(buf, PAGE_SIZE, "%s %s\n",
3436 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3437 			 con->desc);
3438 
3439 }
3440 
3441 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3442 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3443 
3444 static struct attribute *con_dev_attrs[] = {
3445 	&dev_attr_bind.attr,
3446 	&dev_attr_name.attr,
3447 	NULL
3448 };
3449 
3450 ATTRIBUTE_GROUPS(con_dev);
3451 
3452 static int vtconsole_init_device(struct con_driver *con)
3453 {
3454 	con->flag |= CON_DRIVER_FLAG_ATTR;
3455 	return 0;
3456 }
3457 
3458 static void vtconsole_deinit_device(struct con_driver *con)
3459 {
3460 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3461 }
3462 
3463 /**
3464  * con_is_bound - checks if driver is bound to the console
3465  * @csw: console driver
3466  *
3467  * RETURNS: zero if unbound, nonzero if bound
3468  *
3469  * Drivers can call this and if zero, they should release
3470  * all resources allocated on con_startup()
3471  */
3472 int con_is_bound(const struct consw *csw)
3473 {
3474 	int i, bound = 0;
3475 
3476 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3477 		if (con_driver_map[i] == csw) {
3478 			bound = 1;
3479 			break;
3480 		}
3481 	}
3482 
3483 	return bound;
3484 }
3485 EXPORT_SYMBOL(con_is_bound);
3486 
3487 /**
3488  * con_debug_enter - prepare the console for the kernel debugger
3489  * @sw: console driver
3490  *
3491  * Called when the console is taken over by the kernel debugger, this
3492  * function needs to save the current console state, then put the console
3493  * into a state suitable for the kernel debugger.
3494  *
3495  * RETURNS:
3496  * Zero on success, nonzero if a failure occurred when trying to prepare
3497  * the console for the debugger.
3498  */
3499 int con_debug_enter(struct vc_data *vc)
3500 {
3501 	int ret = 0;
3502 
3503 	saved_fg_console = fg_console;
3504 	saved_last_console = last_console;
3505 	saved_want_console = want_console;
3506 	saved_vc_mode = vc->vc_mode;
3507 	saved_console_blanked = console_blanked;
3508 	vc->vc_mode = KD_TEXT;
3509 	console_blanked = 0;
3510 	if (vc->vc_sw->con_debug_enter)
3511 		ret = vc->vc_sw->con_debug_enter(vc);
3512 #ifdef CONFIG_KGDB_KDB
3513 	/* Set the initial LINES variable if it is not already set */
3514 	if (vc->vc_rows < 999) {
3515 		int linecount;
3516 		char lns[4];
3517 		const char *setargs[3] = {
3518 			"set",
3519 			"LINES",
3520 			lns,
3521 		};
3522 		if (kdbgetintenv(setargs[0], &linecount)) {
3523 			snprintf(lns, 4, "%i", vc->vc_rows);
3524 			kdb_set(2, setargs);
3525 		}
3526 	}
3527 	if (vc->vc_cols < 999) {
3528 		int colcount;
3529 		char cols[4];
3530 		const char *setargs[3] = {
3531 			"set",
3532 			"COLUMNS",
3533 			cols,
3534 		};
3535 		if (kdbgetintenv(setargs[0], &colcount)) {
3536 			snprintf(cols, 4, "%i", vc->vc_cols);
3537 			kdb_set(2, setargs);
3538 		}
3539 	}
3540 #endif /* CONFIG_KGDB_KDB */
3541 	return ret;
3542 }
3543 EXPORT_SYMBOL_GPL(con_debug_enter);
3544 
3545 /**
3546  * con_debug_leave - restore console state
3547  * @sw: console driver
3548  *
3549  * Restore the console state to what it was before the kernel debugger
3550  * was invoked.
3551  *
3552  * RETURNS:
3553  * Zero on success, nonzero if a failure occurred when trying to restore
3554  * the console.
3555  */
3556 int con_debug_leave(void)
3557 {
3558 	struct vc_data *vc;
3559 	int ret = 0;
3560 
3561 	fg_console = saved_fg_console;
3562 	last_console = saved_last_console;
3563 	want_console = saved_want_console;
3564 	console_blanked = saved_console_blanked;
3565 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3566 
3567 	vc = vc_cons[fg_console].d;
3568 	if (vc->vc_sw->con_debug_leave)
3569 		ret = vc->vc_sw->con_debug_leave(vc);
3570 	return ret;
3571 }
3572 EXPORT_SYMBOL_GPL(con_debug_leave);
3573 
3574 static int do_register_con_driver(const struct consw *csw, int first, int last)
3575 {
3576 	struct module *owner = csw->owner;
3577 	struct con_driver *con_driver;
3578 	const char *desc;
3579 	int i, retval;
3580 
3581 	WARN_CONSOLE_UNLOCKED();
3582 
3583 	if (!try_module_get(owner))
3584 		return -ENODEV;
3585 
3586 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3587 		con_driver = &registered_con_driver[i];
3588 
3589 		/* already registered */
3590 		if (con_driver->con == csw) {
3591 			retval = -EBUSY;
3592 			goto err;
3593 		}
3594 	}
3595 
3596 	desc = csw->con_startup();
3597 	if (!desc) {
3598 		retval = -ENODEV;
3599 		goto err;
3600 	}
3601 
3602 	retval = -EINVAL;
3603 
3604 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3605 		con_driver = &registered_con_driver[i];
3606 
3607 		if (con_driver->con == NULL &&
3608 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3609 			con_driver->con = csw;
3610 			con_driver->desc = desc;
3611 			con_driver->node = i;
3612 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
3613 			                   CON_DRIVER_FLAG_INIT;
3614 			con_driver->first = first;
3615 			con_driver->last = last;
3616 			retval = 0;
3617 			break;
3618 		}
3619 	}
3620 
3621 	if (retval)
3622 		goto err;
3623 
3624 	con_driver->dev =
3625 		device_create_with_groups(vtconsole_class, NULL,
3626 					  MKDEV(0, con_driver->node),
3627 					  con_driver, con_dev_groups,
3628 					  "vtcon%i", con_driver->node);
3629 	if (IS_ERR(con_driver->dev)) {
3630 		pr_warn("Unable to create device for %s; errno = %ld\n",
3631 			con_driver->desc, PTR_ERR(con_driver->dev));
3632 		con_driver->dev = NULL;
3633 	} else {
3634 		vtconsole_init_device(con_driver);
3635 	}
3636 
3637 err:
3638 	module_put(owner);
3639 	return retval;
3640 }
3641 
3642 
3643 /**
3644  * do_unregister_con_driver - unregister console driver from console layer
3645  * @csw: console driver
3646  *
3647  * DESCRIPTION: All drivers that registers to the console layer must
3648  * call this function upon exit, or if the console driver is in a state
3649  * where it won't be able to handle console services, such as the
3650  * framebuffer console without loaded framebuffer drivers.
3651  *
3652  * The driver must unbind first prior to unregistration.
3653  */
3654 int do_unregister_con_driver(const struct consw *csw)
3655 {
3656 	int i;
3657 
3658 	/* cannot unregister a bound driver */
3659 	if (con_is_bound(csw))
3660 		return -EBUSY;
3661 
3662 	if (csw == conswitchp)
3663 		return -EINVAL;
3664 
3665 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3666 		struct con_driver *con_driver = &registered_con_driver[i];
3667 
3668 		if (con_driver->con == csw) {
3669 			/*
3670 			 * Defer the removal of the sysfs entries since that
3671 			 * will acquire the kernfs s_active lock and we can't
3672 			 * acquire this lock while holding the console lock:
3673 			 * the unbind sysfs entry imposes already the opposite
3674 			 * order. Reset con already here to prevent any later
3675 			 * lookup to succeed and mark this slot as zombie, so
3676 			 * it won't get reused until we complete the removal
3677 			 * in the deferred work.
3678 			 */
3679 			con_driver->con = NULL;
3680 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
3681 			schedule_work(&con_driver_unregister_work);
3682 
3683 			return 0;
3684 		}
3685 	}
3686 
3687 	return -ENODEV;
3688 }
3689 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
3690 
3691 static void con_driver_unregister_callback(struct work_struct *ignored)
3692 {
3693 	int i;
3694 
3695 	console_lock();
3696 
3697 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3698 		struct con_driver *con_driver = &registered_con_driver[i];
3699 
3700 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
3701 			continue;
3702 
3703 		console_unlock();
3704 
3705 		vtconsole_deinit_device(con_driver);
3706 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
3707 
3708 		console_lock();
3709 
3710 		if (WARN_ON_ONCE(con_driver->con))
3711 			con_driver->con = NULL;
3712 		con_driver->desc = NULL;
3713 		con_driver->dev = NULL;
3714 		con_driver->node = 0;
3715 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
3716 		con_driver->flag = 0;
3717 		con_driver->first = 0;
3718 		con_driver->last = 0;
3719 	}
3720 
3721 	console_unlock();
3722 }
3723 
3724 /*
3725  *	If we support more console drivers, this function is used
3726  *	when a driver wants to take over some existing consoles
3727  *	and become default driver for newly opened ones.
3728  *
3729  *	do_take_over_console is basically a register followed by unbind
3730  */
3731 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
3732 {
3733 	int err;
3734 
3735 	err = do_register_con_driver(csw, first, last);
3736 	/*
3737 	 * If we get an busy error we still want to bind the console driver
3738 	 * and return success, as we may have unbound the console driver
3739 	 * but not unregistered it.
3740 	 */
3741 	if (err == -EBUSY)
3742 		err = 0;
3743 	if (!err)
3744 		do_bind_con_driver(csw, first, last, deflt);
3745 
3746 	return err;
3747 }
3748 EXPORT_SYMBOL_GPL(do_take_over_console);
3749 
3750 
3751 /*
3752  * give_up_console is a wrapper to unregister_con_driver. It will only
3753  * work if driver is fully unbound.
3754  */
3755 void give_up_console(const struct consw *csw)
3756 {
3757 	console_lock();
3758 	do_unregister_con_driver(csw);
3759 	console_unlock();
3760 }
3761 
3762 static int __init vtconsole_class_init(void)
3763 {
3764 	int i;
3765 
3766 	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
3767 	if (IS_ERR(vtconsole_class)) {
3768 		pr_warn("Unable to create vt console class; errno = %ld\n",
3769 			PTR_ERR(vtconsole_class));
3770 		vtconsole_class = NULL;
3771 	}
3772 
3773 	/* Add system drivers to sysfs */
3774 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3775 		struct con_driver *con = &registered_con_driver[i];
3776 
3777 		if (con->con && !con->dev) {
3778 			con->dev =
3779 				device_create_with_groups(vtconsole_class, NULL,
3780 							  MKDEV(0, con->node),
3781 							  con, con_dev_groups,
3782 							  "vtcon%i", con->node);
3783 
3784 			if (IS_ERR(con->dev)) {
3785 				pr_warn("Unable to create device for %s; errno = %ld\n",
3786 					con->desc, PTR_ERR(con->dev));
3787 				con->dev = NULL;
3788 			} else {
3789 				vtconsole_init_device(con);
3790 			}
3791 		}
3792 	}
3793 
3794 	return 0;
3795 }
3796 postcore_initcall(vtconsole_class_init);
3797 
3798 #endif
3799 
3800 /*
3801  *	Screen blanking
3802  */
3803 
3804 static int set_vesa_blanking(char __user *p)
3805 {
3806 	unsigned int mode;
3807 
3808 	if (get_user(mode, p + 1))
3809 		return -EFAULT;
3810 
3811 	vesa_blank_mode = (mode < 4) ? mode : 0;
3812 	return 0;
3813 }
3814 
3815 void do_blank_screen(int entering_gfx)
3816 {
3817 	struct vc_data *vc = vc_cons[fg_console].d;
3818 	int i;
3819 
3820 	WARN_CONSOLE_UNLOCKED();
3821 
3822 	if (console_blanked) {
3823 		if (blank_state == blank_vesa_wait) {
3824 			blank_state = blank_off;
3825 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
3826 		}
3827 		return;
3828 	}
3829 
3830 	/* entering graphics mode? */
3831 	if (entering_gfx) {
3832 		hide_cursor(vc);
3833 		save_screen(vc);
3834 		vc->vc_sw->con_blank(vc, -1, 1);
3835 		console_blanked = fg_console + 1;
3836 		blank_state = blank_off;
3837 		set_origin(vc);
3838 		return;
3839 	}
3840 
3841 	if (blank_state != blank_normal_wait)
3842 		return;
3843 	blank_state = blank_off;
3844 
3845 	/* don't blank graphics */
3846 	if (vc->vc_mode != KD_TEXT) {
3847 		console_blanked = fg_console + 1;
3848 		return;
3849 	}
3850 
3851 	hide_cursor(vc);
3852 	del_timer_sync(&console_timer);
3853 	blank_timer_expired = 0;
3854 
3855 	save_screen(vc);
3856 	/* In case we need to reset origin, blanking hook returns 1 */
3857 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
3858 	console_blanked = fg_console + 1;
3859 	if (i)
3860 		set_origin(vc);
3861 
3862 	if (console_blank_hook && console_blank_hook(1))
3863 		return;
3864 
3865 	if (vesa_off_interval && vesa_blank_mode) {
3866 		blank_state = blank_vesa_wait;
3867 		mod_timer(&console_timer, jiffies + vesa_off_interval);
3868 	}
3869 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
3870 }
3871 EXPORT_SYMBOL(do_blank_screen);
3872 
3873 /*
3874  * Called by timer as well as from vt_console_driver
3875  */
3876 void do_unblank_screen(int leaving_gfx)
3877 {
3878 	struct vc_data *vc;
3879 
3880 	/* This should now always be called from a "sane" (read: can schedule)
3881 	 * context for the sake of the low level drivers, except in the special
3882 	 * case of oops_in_progress
3883 	 */
3884 	if (!oops_in_progress)
3885 		might_sleep();
3886 
3887 	WARN_CONSOLE_UNLOCKED();
3888 
3889 	ignore_poke = 0;
3890 	if (!console_blanked)
3891 		return;
3892 	if (!vc_cons_allocated(fg_console)) {
3893 		/* impossible */
3894 		pr_warn("unblank_screen: tty %d not allocated ??\n",
3895 			fg_console + 1);
3896 		return;
3897 	}
3898 	vc = vc_cons[fg_console].d;
3899 	/* Try to unblank in oops case too */
3900 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
3901 		return; /* but leave console_blanked != 0 */
3902 
3903 	if (blankinterval) {
3904 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3905 		blank_state = blank_normal_wait;
3906 	}
3907 
3908 	console_blanked = 0;
3909 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
3910 		/* Low-level driver cannot restore -> do it ourselves */
3911 		update_screen(vc);
3912 	if (console_blank_hook)
3913 		console_blank_hook(0);
3914 	set_palette(vc);
3915 	set_cursor(vc);
3916 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
3917 }
3918 EXPORT_SYMBOL(do_unblank_screen);
3919 
3920 /*
3921  * This is called by the outside world to cause a forced unblank, mostly for
3922  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
3923  * call it with 1 as an argument and so force a mode restore... that may kill
3924  * X or at least garbage the screen but would also make the Oops visible...
3925  */
3926 void unblank_screen(void)
3927 {
3928 	do_unblank_screen(0);
3929 }
3930 
3931 /*
3932  * We defer the timer blanking to work queue so it can take the console mutex
3933  * (console operations can still happen at irq time, but only from printk which
3934  * has the console mutex. Not perfect yet, but better than no locking
3935  */
3936 static void blank_screen_t(struct timer_list *unused)
3937 {
3938 	blank_timer_expired = 1;
3939 	schedule_work(&console_work);
3940 }
3941 
3942 void poke_blanked_console(void)
3943 {
3944 	WARN_CONSOLE_UNLOCKED();
3945 
3946 	/* Add this so we quickly catch whoever might call us in a non
3947 	 * safe context. Nowadays, unblank_screen() isn't to be called in
3948 	 * atomic contexts and is allowed to schedule (with the special case
3949 	 * of oops_in_progress, but that isn't of any concern for this
3950 	 * function. --BenH.
3951 	 */
3952 	might_sleep();
3953 
3954 	/* This isn't perfectly race free, but a race here would be mostly harmless,
3955 	 * at worse, we'll do a spurrious blank and it's unlikely
3956 	 */
3957 	del_timer(&console_timer);
3958 	blank_timer_expired = 0;
3959 
3960 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
3961 		return;
3962 	if (console_blanked)
3963 		unblank_screen();
3964 	else if (blankinterval) {
3965 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3966 		blank_state = blank_normal_wait;
3967 	}
3968 }
3969 
3970 /*
3971  *	Palettes
3972  */
3973 
3974 static void set_palette(struct vc_data *vc)
3975 {
3976 	WARN_CONSOLE_UNLOCKED();
3977 
3978 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
3979 		vc->vc_sw->con_set_palette(vc, color_table);
3980 }
3981 
3982 /*
3983  * Load palette into the DAC registers. arg points to a colour
3984  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
3985  */
3986 
3987 int con_set_cmap(unsigned char __user *arg)
3988 {
3989 	int i, j, k;
3990 	unsigned char colormap[3*16];
3991 
3992 	if (copy_from_user(colormap, arg, sizeof(colormap)))
3993 		return -EFAULT;
3994 
3995 	console_lock();
3996 	for (i = k = 0; i < 16; i++) {
3997 		default_red[i] = colormap[k++];
3998 		default_grn[i] = colormap[k++];
3999 		default_blu[i] = colormap[k++];
4000 	}
4001 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
4002 		if (!vc_cons_allocated(i))
4003 			continue;
4004 		for (j = k = 0; j < 16; j++) {
4005 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4006 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4007 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4008 		}
4009 		set_palette(vc_cons[i].d);
4010 	}
4011 	console_unlock();
4012 
4013 	return 0;
4014 }
4015 
4016 int con_get_cmap(unsigned char __user *arg)
4017 {
4018 	int i, k;
4019 	unsigned char colormap[3*16];
4020 
4021 	console_lock();
4022 	for (i = k = 0; i < 16; i++) {
4023 		colormap[k++] = default_red[i];
4024 		colormap[k++] = default_grn[i];
4025 		colormap[k++] = default_blu[i];
4026 	}
4027 	console_unlock();
4028 
4029 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4030 		return -EFAULT;
4031 
4032 	return 0;
4033 }
4034 
4035 void reset_palette(struct vc_data *vc)
4036 {
4037 	int j, k;
4038 	for (j=k=0; j<16; j++) {
4039 		vc->vc_palette[k++] = default_red[j];
4040 		vc->vc_palette[k++] = default_grn[j];
4041 		vc->vc_palette[k++] = default_blu[j];
4042 	}
4043 	set_palette(vc);
4044 }
4045 
4046 /*
4047  *  Font switching
4048  *
4049  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4050  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4051  *  depending on width) reserved for each character which is kinda wasty, but
4052  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4053  *  is up to the actual low-level console-driver convert data into its favorite
4054  *  format (maybe we should add a `fontoffset' field to the `display'
4055  *  structure so we won't have to convert the fontdata all the time.
4056  *  /Jes
4057  */
4058 
4059 #define max_font_size 65536
4060 
4061 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4062 {
4063 	struct console_font font;
4064 	int rc = -EINVAL;
4065 	int c;
4066 
4067 	if (op->data) {
4068 		font.data = kmalloc(max_font_size, GFP_KERNEL);
4069 		if (!font.data)
4070 			return -ENOMEM;
4071 	} else
4072 		font.data = NULL;
4073 
4074 	console_lock();
4075 	if (vc->vc_mode != KD_TEXT)
4076 		rc = -EINVAL;
4077 	else if (vc->vc_sw->con_font_get)
4078 		rc = vc->vc_sw->con_font_get(vc, &font);
4079 	else
4080 		rc = -ENOSYS;
4081 	console_unlock();
4082 
4083 	if (rc)
4084 		goto out;
4085 
4086 	c = (font.width+7)/8 * 32 * font.charcount;
4087 
4088 	if (op->data && font.charcount > op->charcount)
4089 		rc = -ENOSPC;
4090 	if (!(op->flags & KD_FONT_FLAG_OLD)) {
4091 		if (font.width > op->width || font.height > op->height)
4092 			rc = -ENOSPC;
4093 	} else {
4094 		if (font.width != 8)
4095 			rc = -EIO;
4096 		else if ((op->height && font.height > op->height) ||
4097 			 font.height > 32)
4098 			rc = -ENOSPC;
4099 	}
4100 	if (rc)
4101 		goto out;
4102 
4103 	op->height = font.height;
4104 	op->width = font.width;
4105 	op->charcount = font.charcount;
4106 
4107 	if (op->data && copy_to_user(op->data, font.data, c))
4108 		rc = -EFAULT;
4109 
4110 out:
4111 	kfree(font.data);
4112 	return rc;
4113 }
4114 
4115 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4116 {
4117 	struct console_font font;
4118 	int rc = -EINVAL;
4119 	int size;
4120 
4121 	if (vc->vc_mode != KD_TEXT)
4122 		return -EINVAL;
4123 	if (!op->data)
4124 		return -EINVAL;
4125 	if (op->charcount > 512)
4126 		return -EINVAL;
4127 	if (op->width <= 0 || op->width > 32 || op->height > 32)
4128 		return -EINVAL;
4129 	size = (op->width+7)/8 * 32 * op->charcount;
4130 	if (size > max_font_size)
4131 		return -ENOSPC;
4132 
4133 	font.data = memdup_user(op->data, size);
4134 	if (IS_ERR(font.data))
4135 		return PTR_ERR(font.data);
4136 
4137 	if (!op->height) {		/* Need to guess font height [compat] */
4138 		int h, i;
4139 		u8 *charmap = font.data;
4140 
4141 		/*
4142 		 * If from KDFONTOP ioctl, don't allow things which can be done
4143 		 * in userland,so that we can get rid of this soon
4144 		 */
4145 		if (!(op->flags & KD_FONT_FLAG_OLD)) {
4146 			kfree(font.data);
4147 			return -EINVAL;
4148 		}
4149 
4150 		for (h = 32; h > 0; h--)
4151 			for (i = 0; i < op->charcount; i++)
4152 				if (charmap[32*i+h-1])
4153 					goto nonzero;
4154 
4155 		kfree(font.data);
4156 		return -EINVAL;
4157 
4158 	nonzero:
4159 		op->height = h;
4160 	}
4161 
4162 	font.charcount = op->charcount;
4163 	font.width = op->width;
4164 	font.height = op->height;
4165 
4166 	console_lock();
4167 	if (vc->vc_mode != KD_TEXT)
4168 		rc = -EINVAL;
4169 	else if (vc->vc_sw->con_font_set)
4170 		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4171 	else
4172 		rc = -ENOSYS;
4173 	console_unlock();
4174 	kfree(font.data);
4175 	return rc;
4176 }
4177 
4178 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4179 {
4180 	struct console_font font = {.width = op->width, .height = op->height};
4181 	char name[MAX_FONT_NAME];
4182 	char *s = name;
4183 	int rc;
4184 
4185 
4186 	if (!op->data)
4187 		s = NULL;
4188 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4189 		return -EFAULT;
4190 	else
4191 		name[MAX_FONT_NAME - 1] = 0;
4192 
4193 	console_lock();
4194 	if (vc->vc_mode != KD_TEXT) {
4195 		console_unlock();
4196 		return -EINVAL;
4197 	}
4198 	if (vc->vc_sw->con_font_default)
4199 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4200 	else
4201 		rc = -ENOSYS;
4202 	console_unlock();
4203 	if (!rc) {
4204 		op->width = font.width;
4205 		op->height = font.height;
4206 	}
4207 	return rc;
4208 }
4209 
4210 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4211 {
4212 	int con = op->height;
4213 	int rc;
4214 
4215 
4216 	console_lock();
4217 	if (vc->vc_mode != KD_TEXT)
4218 		rc = -EINVAL;
4219 	else if (!vc->vc_sw->con_font_copy)
4220 		rc = -ENOSYS;
4221 	else if (con < 0 || !vc_cons_allocated(con))
4222 		rc = -ENOTTY;
4223 	else if (con == vc->vc_num)	/* nothing to do */
4224 		rc = 0;
4225 	else
4226 		rc = vc->vc_sw->con_font_copy(vc, con);
4227 	console_unlock();
4228 	return rc;
4229 }
4230 
4231 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4232 {
4233 	switch (op->op) {
4234 	case KD_FONT_OP_SET:
4235 		return con_font_set(vc, op);
4236 	case KD_FONT_OP_GET:
4237 		return con_font_get(vc, op);
4238 	case KD_FONT_OP_SET_DEFAULT:
4239 		return con_font_default(vc, op);
4240 	case KD_FONT_OP_COPY:
4241 		return con_font_copy(vc, op);
4242 	}
4243 	return -ENOSYS;
4244 }
4245 
4246 /*
4247  *	Interface exported to selection and vcs.
4248  */
4249 
4250 /* used by selection */
4251 u16 screen_glyph(struct vc_data *vc, int offset)
4252 {
4253 	u16 w = scr_readw(screenpos(vc, offset, 1));
4254 	u16 c = w & 0xff;
4255 
4256 	if (w & vc->vc_hi_font_mask)
4257 		c |= 0x100;
4258 	return c;
4259 }
4260 EXPORT_SYMBOL_GPL(screen_glyph);
4261 
4262 /* used by vcs - note the word offset */
4263 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4264 {
4265 	return screenpos(vc, 2 * w_offset, viewed);
4266 }
4267 EXPORT_SYMBOL_GPL(screen_pos);
4268 
4269 void getconsxy(struct vc_data *vc, unsigned char *p)
4270 {
4271 	p[0] = vc->vc_x;
4272 	p[1] = vc->vc_y;
4273 }
4274 
4275 void putconsxy(struct vc_data *vc, unsigned char *p)
4276 {
4277 	hide_cursor(vc);
4278 	gotoxy(vc, p[0], p[1]);
4279 	set_cursor(vc);
4280 }
4281 
4282 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4283 {
4284 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4285 		return softcursor_original;
4286 	return scr_readw(org);
4287 }
4288 
4289 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4290 {
4291 	scr_writew(val, org);
4292 	if ((unsigned long)org == vc->vc_pos) {
4293 		softcursor_original = -1;
4294 		add_softcursor(vc);
4295 	}
4296 }
4297 
4298 void vcs_scr_updated(struct vc_data *vc)
4299 {
4300 	notify_update(vc);
4301 }
4302 
4303 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4304 		unsigned int rolled_over, void *base, unsigned int size)
4305 {
4306 	unsigned long ubase = (unsigned long)base;
4307 	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4308 	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4309 	ptrdiff_t origin = (void *)c->vc_origin - base;
4310 	int margin = c->vc_size_row * 4;
4311 	int from, wrap, from_off, avail;
4312 
4313 	/* Turn scrollback off */
4314 	if (!lines) {
4315 		c->vc_visible_origin = c->vc_origin;
4316 		return;
4317 	}
4318 
4319 	/* Do we have already enough to allow jumping from 0 to the end? */
4320 	if (rolled_over > scr_end + margin) {
4321 		from = scr_end;
4322 		wrap = rolled_over + c->vc_size_row;
4323 	} else {
4324 		from = 0;
4325 		wrap = size;
4326 	}
4327 
4328 	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4329 	avail = (origin - from + wrap) % wrap;
4330 
4331 	/* Only a little piece would be left? Show all incl. the piece! */
4332 	if (avail < 2 * margin)
4333 		margin = 0;
4334 	if (from_off < margin)
4335 		from_off = 0;
4336 	if (from_off > avail - margin)
4337 		from_off = avail;
4338 
4339 	c->vc_visible_origin = ubase + (from + from_off) % wrap;
4340 }
4341 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4342 
4343 /*
4344  *	Visible symbols for modules
4345  */
4346 
4347 EXPORT_SYMBOL(color_table);
4348 EXPORT_SYMBOL(default_red);
4349 EXPORT_SYMBOL(default_grn);
4350 EXPORT_SYMBOL(default_blu);
4351 EXPORT_SYMBOL(update_region);
4352 EXPORT_SYMBOL(redraw_screen);
4353 EXPORT_SYMBOL(vc_resize);
4354 EXPORT_SYMBOL(fg_console);
4355 EXPORT_SYMBOL(console_blank_hook);
4356 EXPORT_SYMBOL(console_blanked);
4357 EXPORT_SYMBOL(vc_cons);
4358 EXPORT_SYMBOL(global_cursor_default);
4359 #ifndef VT_SINGLE_DRIVER
4360 EXPORT_SYMBOL(give_up_console);
4361 #endif
4362