xref: /openbmc/linux/drivers/tty/vt/vt.c (revision 6dfcd296)
1 /*
2  *  Copyright (C) 1991, 1992  Linus Torvalds
3  */
4 
5 /*
6  * Hopefully this will be a rather complete VT102 implementation.
7  *
8  * Beeping thanks to John T Kohl.
9  *
10  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
11  *   Chars, and VT100 enhancements by Peter MacDonald.
12  *
13  * Copy and paste function by Andrew Haylett,
14  *   some enhancements by Alessandro Rubini.
15  *
16  * Code to check for different video-cards mostly by Galen Hunt,
17  * <g-hunt@ee.utah.edu>
18  *
19  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
20  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
21  *
22  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
23  * Resizing of consoles, aeb, 940926
24  *
25  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
26  * <poe@daimi.aau.dk>
27  *
28  * User-defined bell sound, new setterm control sequences and printk
29  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
30  *
31  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
32  *
33  * Merge with the abstract console driver by Geert Uytterhoeven
34  * <geert@linux-m68k.org>, Jan 1997.
35  *
36  *   Original m68k console driver modifications by
37  *
38  *     - Arno Griffioen <arno@usn.nl>
39  *     - David Carter <carter@cs.bris.ac.uk>
40  *
41  *   The abstract console driver provides a generic interface for a text
42  *   console. It supports VGA text mode, frame buffer based graphical consoles
43  *   and special graphics processors that are only accessible through some
44  *   registers (e.g. a TMS340x0 GSP).
45  *
46  *   The interface to the hardware is specified using a special structure
47  *   (struct consw) which contains function pointers to console operations
48  *   (see <linux/console.h> for more information).
49  *
50  * Support for changeable cursor shape
51  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
52  *
53  * Ported to i386 and con_scrolldelta fixed
54  * by Emmanuel Marty <core@ggi-project.org>, April 1998
55  *
56  * Resurrected character buffers in videoram plus lots of other trickery
57  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
58  *
59  * Removed old-style timers, introduced console_timer, made timer
60  * deletion SMP-safe.  17Jun00, Andrew Morton
61  *
62  * Removed console_lock, enabled interrupts across all console operations
63  * 13 March 2001, Andrew Morton
64  *
65  * Fixed UTF-8 mode so alternate charset modes always work according
66  * to control sequences interpreted in do_con_trol function
67  * preserving backward VT100 semigraphics compatibility,
68  * malformed UTF sequences represented as sequences of replacement glyphs,
69  * original codes or '?' as a last resort if replacement glyph is undefined
70  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
71  */
72 
73 #include <linux/module.h>
74 #include <linux/types.h>
75 #include <linux/sched.h>
76 #include <linux/tty.h>
77 #include <linux/tty_flip.h>
78 #include <linux/kernel.h>
79 #include <linux/string.h>
80 #include <linux/errno.h>
81 #include <linux/kd.h>
82 #include <linux/slab.h>
83 #include <linux/major.h>
84 #include <linux/mm.h>
85 #include <linux/console.h>
86 #include <linux/init.h>
87 #include <linux/mutex.h>
88 #include <linux/vt_kern.h>
89 #include <linux/selection.h>
90 #include <linux/tiocl.h>
91 #include <linux/kbd_kern.h>
92 #include <linux/consolemap.h>
93 #include <linux/timer.h>
94 #include <linux/interrupt.h>
95 #include <linux/workqueue.h>
96 #include <linux/pm.h>
97 #include <linux/font.h>
98 #include <linux/bitops.h>
99 #include <linux/notifier.h>
100 #include <linux/device.h>
101 #include <linux/io.h>
102 #include <linux/uaccess.h>
103 #include <linux/kdb.h>
104 #include <linux/ctype.h>
105 
106 #define MAX_NR_CON_DRIVER 16
107 
108 #define CON_DRIVER_FLAG_MODULE 1
109 #define CON_DRIVER_FLAG_INIT   2
110 #define CON_DRIVER_FLAG_ATTR   4
111 #define CON_DRIVER_FLAG_ZOMBIE 8
112 
113 struct con_driver {
114 	const struct consw *con;
115 	const char *desc;
116 	struct device *dev;
117 	int node;
118 	int first;
119 	int last;
120 	int flag;
121 };
122 
123 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
124 const struct consw *conswitchp;
125 
126 /* A bitmap for codes <32. A bit of 1 indicates that the code
127  * corresponding to that bit number invokes some special action
128  * (such as cursor movement) and should not be displayed as a
129  * glyph unless the disp_ctrl mode is explicitly enabled.
130  */
131 #define CTRL_ACTION 0x0d00ff81
132 #define CTRL_ALWAYS 0x0800f501	/* Cannot be overridden by disp_ctrl */
133 
134 /*
135  * Here is the default bell parameters: 750HZ, 1/8th of a second
136  */
137 #define DEFAULT_BELL_PITCH	750
138 #define DEFAULT_BELL_DURATION	(HZ/8)
139 #define DEFAULT_CURSOR_BLINK_MS	200
140 
141 struct vc vc_cons [MAX_NR_CONSOLES];
142 
143 #ifndef VT_SINGLE_DRIVER
144 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
145 #endif
146 
147 static int con_open(struct tty_struct *, struct file *);
148 static void vc_init(struct vc_data *vc, unsigned int rows,
149 		    unsigned int cols, int do_clear);
150 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
151 static void save_cur(struct vc_data *vc);
152 static void reset_terminal(struct vc_data *vc, int do_clear);
153 static void con_flush_chars(struct tty_struct *tty);
154 static int set_vesa_blanking(char __user *p);
155 static void set_cursor(struct vc_data *vc);
156 static void hide_cursor(struct vc_data *vc);
157 static void console_callback(struct work_struct *ignored);
158 static void con_driver_unregister_callback(struct work_struct *ignored);
159 static void blank_screen_t(unsigned long dummy);
160 static void set_palette(struct vc_data *vc);
161 
162 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
163 
164 static int printable;		/* Is console ready for printing? */
165 int default_utf8 = true;
166 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
167 int global_cursor_default = -1;
168 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
169 
170 static int cur_default = CUR_DEFAULT;
171 module_param(cur_default, int, S_IRUGO | S_IWUSR);
172 
173 /*
174  * ignore_poke: don't unblank the screen when things are typed.  This is
175  * mainly for the privacy of braille terminal users.
176  */
177 static int ignore_poke;
178 
179 int do_poke_blanked_console;
180 int console_blanked;
181 
182 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
183 static int vesa_off_interval;
184 static int blankinterval = 10*60;
185 core_param(consoleblank, blankinterval, int, 0444);
186 
187 static DECLARE_WORK(console_work, console_callback);
188 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
189 
190 /*
191  * fg_console is the current virtual console,
192  * last_console is the last used one,
193  * want_console is the console we want to switch to,
194  * saved_* variants are for save/restore around kernel debugger enter/leave
195  */
196 int fg_console;
197 int last_console;
198 int want_console = -1;
199 static int saved_fg_console;
200 static int saved_last_console;
201 static int saved_want_console;
202 static int saved_vc_mode;
203 static int saved_console_blanked;
204 
205 /*
206  * For each existing display, we have a pointer to console currently visible
207  * on that display, allowing consoles other than fg_console to be refreshed
208  * appropriately. Unless the low-level driver supplies its own display_fg
209  * variable, we use this one for the "master display".
210  */
211 static struct vc_data *master_display_fg;
212 
213 /*
214  * Unfortunately, we need to delay tty echo when we're currently writing to the
215  * console since the code is (and always was) not re-entrant, so we schedule
216  * all flip requests to process context with schedule-task() and run it from
217  * console_callback().
218  */
219 
220 /*
221  * For the same reason, we defer scrollback to the console callback.
222  */
223 static int scrollback_delta;
224 
225 /*
226  * Hook so that the power management routines can (un)blank
227  * the console on our behalf.
228  */
229 int (*console_blank_hook)(int);
230 
231 static DEFINE_TIMER(console_timer, blank_screen_t, 0, 0);
232 static int blank_state;
233 static int blank_timer_expired;
234 enum {
235 	blank_off = 0,
236 	blank_normal_wait,
237 	blank_vesa_wait,
238 };
239 
240 /*
241  * /sys/class/tty/tty0/
242  *
243  * the attribute 'active' contains the name of the current vc
244  * console and it supports poll() to detect vc switches
245  */
246 static struct device *tty0dev;
247 
248 /*
249  * Notifier list for console events.
250  */
251 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
252 
253 int register_vt_notifier(struct notifier_block *nb)
254 {
255 	return atomic_notifier_chain_register(&vt_notifier_list, nb);
256 }
257 EXPORT_SYMBOL_GPL(register_vt_notifier);
258 
259 int unregister_vt_notifier(struct notifier_block *nb)
260 {
261 	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
262 }
263 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
264 
265 static void notify_write(struct vc_data *vc, unsigned int unicode)
266 {
267 	struct vt_notifier_param param = { .vc = vc, .c = unicode };
268 	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
269 }
270 
271 static void notify_update(struct vc_data *vc)
272 {
273 	struct vt_notifier_param param = { .vc = vc };
274 	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
275 }
276 /*
277  *	Low-Level Functions
278  */
279 
280 static inline bool con_is_fg(const struct vc_data *vc)
281 {
282 	return vc->vc_num == fg_console;
283 }
284 
285 static inline bool con_should_update(const struct vc_data *vc)
286 {
287 	return con_is_visible(vc) && !console_blanked;
288 }
289 
290 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
291 {
292 	unsigned short *p;
293 
294 	if (!viewed)
295 		p = (unsigned short *)(vc->vc_origin + offset);
296 	else if (!vc->vc_sw->con_screen_pos)
297 		p = (unsigned short *)(vc->vc_visible_origin + offset);
298 	else
299 		p = vc->vc_sw->con_screen_pos(vc, offset);
300 	return p;
301 }
302 
303 /* Called  from the keyboard irq path.. */
304 static inline void scrolldelta(int lines)
305 {
306 	/* FIXME */
307 	/* scrolldelta needs some kind of consistency lock, but the BKL was
308 	   and still is not protecting versus the scheduled back end */
309 	scrollback_delta += lines;
310 	schedule_console_callback();
311 }
312 
313 void schedule_console_callback(void)
314 {
315 	schedule_work(&console_work);
316 }
317 
318 static void scrup(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
319 {
320 	unsigned short *d, *s;
321 
322 	if (t+nr >= b)
323 		nr = b - t - 1;
324 	if (b > vc->vc_rows || t >= b || nr < 1)
325 		return;
326 	if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, SM_UP, nr))
327 		return;
328 	d = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
329 	s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * (t + nr));
330 	scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
331 	scr_memsetw(d + (b - t - nr) * vc->vc_cols, vc->vc_video_erase_char,
332 		    vc->vc_size_row * nr);
333 }
334 
335 static void scrdown(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
336 {
337 	unsigned short *s;
338 	unsigned int step;
339 
340 	if (t+nr >= b)
341 		nr = b - t - 1;
342 	if (b > vc->vc_rows || t >= b || nr < 1)
343 		return;
344 	if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, SM_DOWN, nr))
345 		return;
346 	s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
347 	step = vc->vc_cols * nr;
348 	scr_memmovew(s + step, s, (b - t - nr) * vc->vc_size_row);
349 	scr_memsetw(s, vc->vc_video_erase_char, 2 * step);
350 }
351 
352 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
353 {
354 	unsigned int xx, yy, offset;
355 	u16 *p;
356 
357 	p = (u16 *) start;
358 	if (!vc->vc_sw->con_getxy) {
359 		offset = (start - vc->vc_origin) / 2;
360 		xx = offset % vc->vc_cols;
361 		yy = offset / vc->vc_cols;
362 	} else {
363 		int nxx, nyy;
364 		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
365 		xx = nxx; yy = nyy;
366 	}
367 	for(;;) {
368 		u16 attrib = scr_readw(p) & 0xff00;
369 		int startx = xx;
370 		u16 *q = p;
371 		while (xx < vc->vc_cols && count) {
372 			if (attrib != (scr_readw(p) & 0xff00)) {
373 				if (p > q)
374 					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
375 				startx = xx;
376 				q = p;
377 				attrib = scr_readw(p) & 0xff00;
378 			}
379 			p++;
380 			xx++;
381 			count--;
382 		}
383 		if (p > q)
384 			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
385 		if (!count)
386 			break;
387 		xx = 0;
388 		yy++;
389 		if (vc->vc_sw->con_getxy) {
390 			p = (u16 *)start;
391 			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
392 		}
393 	}
394 }
395 
396 void update_region(struct vc_data *vc, unsigned long start, int count)
397 {
398 	WARN_CONSOLE_UNLOCKED();
399 
400 	if (con_should_update(vc)) {
401 		hide_cursor(vc);
402 		do_update_region(vc, start, count);
403 		set_cursor(vc);
404 	}
405 }
406 
407 /* Structure of attributes is hardware-dependent */
408 
409 static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
410     u8 _underline, u8 _reverse, u8 _italic)
411 {
412 	if (vc->vc_sw->con_build_attr)
413 		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
414 		       _blink, _underline, _reverse, _italic);
415 
416 /*
417  * ++roman: I completely changed the attribute format for monochrome
418  * mode (!can_do_color). The formerly used MDA (monochrome display
419  * adapter) format didn't allow the combination of certain effects.
420  * Now the attribute is just a bit vector:
421  *  Bit 0..1: intensity (0..2)
422  *  Bit 2   : underline
423  *  Bit 3   : reverse
424  *  Bit 7   : blink
425  */
426 	{
427 	u8 a = _color;
428 	if (!vc->vc_can_do_color)
429 		return _intensity |
430 		       (_italic ? 2 : 0) |
431 		       (_underline ? 4 : 0) |
432 		       (_reverse ? 8 : 0) |
433 		       (_blink ? 0x80 : 0);
434 	if (_italic)
435 		a = (a & 0xF0) | vc->vc_itcolor;
436 	else if (_underline)
437 		a = (a & 0xf0) | vc->vc_ulcolor;
438 	else if (_intensity == 0)
439 		a = (a & 0xf0) | vc->vc_ulcolor;
440 	if (_reverse)
441 		a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
442 	if (_blink)
443 		a ^= 0x80;
444 	if (_intensity == 2)
445 		a ^= 0x08;
446 	if (vc->vc_hi_font_mask == 0x100)
447 		a <<= 1;
448 	return a;
449 	}
450 }
451 
452 static void update_attr(struct vc_data *vc)
453 {
454 	vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
455 	              vc->vc_blink, vc->vc_underline,
456 	              vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
457 	vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
458 }
459 
460 /* Note: inverting the screen twice should revert to the original state */
461 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
462 {
463 	unsigned short *p;
464 
465 	WARN_CONSOLE_UNLOCKED();
466 
467 	count /= 2;
468 	p = screenpos(vc, offset, viewed);
469 	if (vc->vc_sw->con_invert_region) {
470 		vc->vc_sw->con_invert_region(vc, p, count);
471 	} else {
472 		u16 *q = p;
473 		int cnt = count;
474 		u16 a;
475 
476 		if (!vc->vc_can_do_color) {
477 			while (cnt--) {
478 			    a = scr_readw(q);
479 			    a ^= 0x0800;
480 			    scr_writew(a, q);
481 			    q++;
482 			}
483 		} else if (vc->vc_hi_font_mask == 0x100) {
484 			while (cnt--) {
485 				a = scr_readw(q);
486 				a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
487 				scr_writew(a, q);
488 				q++;
489 			}
490 		} else {
491 			while (cnt--) {
492 				a = scr_readw(q);
493 				a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
494 				scr_writew(a, q);
495 				q++;
496 			}
497 		}
498 	}
499 
500 	if (con_should_update(vc))
501 		do_update_region(vc, (unsigned long) p, count);
502 	notify_update(vc);
503 }
504 
505 /* used by selection: complement pointer position */
506 void complement_pos(struct vc_data *vc, int offset)
507 {
508 	static int old_offset = -1;
509 	static unsigned short old;
510 	static unsigned short oldx, oldy;
511 
512 	WARN_CONSOLE_UNLOCKED();
513 
514 	if (old_offset != -1 && old_offset >= 0 &&
515 	    old_offset < vc->vc_screenbuf_size) {
516 		scr_writew(old, screenpos(vc, old_offset, 1));
517 		if (con_should_update(vc))
518 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
519 		notify_update(vc);
520 	}
521 
522 	old_offset = offset;
523 
524 	if (offset != -1 && offset >= 0 &&
525 	    offset < vc->vc_screenbuf_size) {
526 		unsigned short new;
527 		unsigned short *p;
528 		p = screenpos(vc, offset, 1);
529 		old = scr_readw(p);
530 		new = old ^ vc->vc_complement_mask;
531 		scr_writew(new, p);
532 		if (con_should_update(vc)) {
533 			oldx = (offset >> 1) % vc->vc_cols;
534 			oldy = (offset >> 1) / vc->vc_cols;
535 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
536 		}
537 		notify_update(vc);
538 	}
539 }
540 
541 static void insert_char(struct vc_data *vc, unsigned int nr)
542 {
543 	unsigned short *p = (unsigned short *) vc->vc_pos;
544 
545 	scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
546 	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
547 	vc->vc_need_wrap = 0;
548 	if (con_should_update(vc))
549 		do_update_region(vc, (unsigned long) p,
550 			vc->vc_cols - vc->vc_x);
551 }
552 
553 static void delete_char(struct vc_data *vc, unsigned int nr)
554 {
555 	unsigned short *p = (unsigned short *) vc->vc_pos;
556 
557 	scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
558 	scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
559 			nr * 2);
560 	vc->vc_need_wrap = 0;
561 	if (con_should_update(vc))
562 		do_update_region(vc, (unsigned long) p,
563 			vc->vc_cols - vc->vc_x);
564 }
565 
566 static int softcursor_original = -1;
567 
568 static void add_softcursor(struct vc_data *vc)
569 {
570 	int i = scr_readw((u16 *) vc->vc_pos);
571 	u32 type = vc->vc_cursor_type;
572 
573 	if (! (type & 0x10)) return;
574 	if (softcursor_original != -1) return;
575 	softcursor_original = i;
576 	i |= ((type >> 8) & 0xff00 );
577 	i ^= ((type) & 0xff00 );
578 	if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
579 	if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
580 	scr_writew(i, (u16 *) vc->vc_pos);
581 	if (con_should_update(vc))
582 		vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
583 }
584 
585 static void hide_softcursor(struct vc_data *vc)
586 {
587 	if (softcursor_original != -1) {
588 		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
589 		if (con_should_update(vc))
590 			vc->vc_sw->con_putc(vc, softcursor_original,
591 					vc->vc_y, vc->vc_x);
592 		softcursor_original = -1;
593 	}
594 }
595 
596 static void hide_cursor(struct vc_data *vc)
597 {
598 	if (vc == sel_cons)
599 		clear_selection();
600 	vc->vc_sw->con_cursor(vc, CM_ERASE);
601 	hide_softcursor(vc);
602 }
603 
604 static void set_cursor(struct vc_data *vc)
605 {
606 	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
607 		return;
608 	if (vc->vc_deccm) {
609 		if (vc == sel_cons)
610 			clear_selection();
611 		add_softcursor(vc);
612 		if ((vc->vc_cursor_type & 0x0f) != 1)
613 			vc->vc_sw->con_cursor(vc, CM_DRAW);
614 	} else
615 		hide_cursor(vc);
616 }
617 
618 static void set_origin(struct vc_data *vc)
619 {
620 	WARN_CONSOLE_UNLOCKED();
621 
622 	if (!con_is_visible(vc) ||
623 	    !vc->vc_sw->con_set_origin ||
624 	    !vc->vc_sw->con_set_origin(vc))
625 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
626 	vc->vc_visible_origin = vc->vc_origin;
627 	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
628 	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
629 }
630 
631 static void save_screen(struct vc_data *vc)
632 {
633 	WARN_CONSOLE_UNLOCKED();
634 
635 	if (vc->vc_sw->con_save_screen)
636 		vc->vc_sw->con_save_screen(vc);
637 }
638 
639 /*
640  *	Redrawing of screen
641  */
642 
643 void clear_buffer_attributes(struct vc_data *vc)
644 {
645 	unsigned short *p = (unsigned short *)vc->vc_origin;
646 	int count = vc->vc_screenbuf_size / 2;
647 	int mask = vc->vc_hi_font_mask | 0xff;
648 
649 	for (; count > 0; count--, p++) {
650 		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
651 	}
652 }
653 
654 void redraw_screen(struct vc_data *vc, int is_switch)
655 {
656 	int redraw = 0;
657 
658 	WARN_CONSOLE_UNLOCKED();
659 
660 	if (!vc) {
661 		/* strange ... */
662 		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
663 		return;
664 	}
665 
666 	if (is_switch) {
667 		struct vc_data *old_vc = vc_cons[fg_console].d;
668 		if (old_vc == vc)
669 			return;
670 		if (!con_is_visible(vc))
671 			redraw = 1;
672 		*vc->vc_display_fg = vc;
673 		fg_console = vc->vc_num;
674 		hide_cursor(old_vc);
675 		if (!con_is_visible(old_vc)) {
676 			save_screen(old_vc);
677 			set_origin(old_vc);
678 		}
679 		if (tty0dev)
680 			sysfs_notify(&tty0dev->kobj, NULL, "active");
681 	} else {
682 		hide_cursor(vc);
683 		redraw = 1;
684 	}
685 
686 	if (redraw) {
687 		int update;
688 		int old_was_color = vc->vc_can_do_color;
689 
690 		set_origin(vc);
691 		update = vc->vc_sw->con_switch(vc);
692 		set_palette(vc);
693 		/*
694 		 * If console changed from mono<->color, the best we can do
695 		 * is to clear the buffer attributes. As it currently stands,
696 		 * rebuilding new attributes from the old buffer is not doable
697 		 * without overly complex code.
698 		 */
699 		if (old_was_color != vc->vc_can_do_color) {
700 			update_attr(vc);
701 			clear_buffer_attributes(vc);
702 		}
703 
704 		/* Forcibly update if we're panicing */
705 		if ((update && vc->vc_mode != KD_GRAPHICS) ||
706 		    vt_force_oops_output(vc))
707 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
708 	}
709 	set_cursor(vc);
710 	if (is_switch) {
711 		set_leds();
712 		compute_shiftstate();
713 		notify_update(vc);
714 	}
715 }
716 
717 /*
718  *	Allocation, freeing and resizing of VTs.
719  */
720 
721 int vc_cons_allocated(unsigned int i)
722 {
723 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
724 }
725 
726 static void visual_init(struct vc_data *vc, int num, int init)
727 {
728 	/* ++Geert: vc->vc_sw->con_init determines console size */
729 	if (vc->vc_sw)
730 		module_put(vc->vc_sw->owner);
731 	vc->vc_sw = conswitchp;
732 #ifndef VT_SINGLE_DRIVER
733 	if (con_driver_map[num])
734 		vc->vc_sw = con_driver_map[num];
735 #endif
736 	__module_get(vc->vc_sw->owner);
737 	vc->vc_num = num;
738 	vc->vc_display_fg = &master_display_fg;
739 	if (vc->vc_uni_pagedir_loc)
740 		con_free_unimap(vc);
741 	vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
742 	vc->vc_uni_pagedir = NULL;
743 	vc->vc_hi_font_mask = 0;
744 	vc->vc_complement_mask = 0;
745 	vc->vc_can_do_color = 0;
746 	vc->vc_panic_force_write = false;
747 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
748 	vc->vc_sw->con_init(vc, init);
749 	if (!vc->vc_complement_mask)
750 		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
751 	vc->vc_s_complement_mask = vc->vc_complement_mask;
752 	vc->vc_size_row = vc->vc_cols << 1;
753 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
754 }
755 
756 int vc_allocate(unsigned int currcons)	/* return 0 on success */
757 {
758 	struct vt_notifier_param param;
759 	struct vc_data *vc;
760 
761 	WARN_CONSOLE_UNLOCKED();
762 
763 	if (currcons >= MAX_NR_CONSOLES)
764 		return -ENXIO;
765 
766 	if (vc_cons[currcons].d)
767 		return 0;
768 
769 	/* due to the granularity of kmalloc, we waste some memory here */
770 	/* the alloc is done in two steps, to optimize the common situation
771 	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
772 	/* although the numbers above are not valid since long ago, the
773 	   point is still up-to-date and the comment still has its value
774 	   even if only as a historical artifact.  --mj, July 1998 */
775 	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
776 	if (!vc)
777 		return -ENOMEM;
778 
779 	vc_cons[currcons].d = vc;
780 	tty_port_init(&vc->port);
781 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
782 
783 	visual_init(vc, currcons, 1);
784 
785 	if (!*vc->vc_uni_pagedir_loc)
786 		con_set_default_unimap(vc);
787 
788 	vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
789 	if (!vc->vc_screenbuf)
790 		goto err_free;
791 
792 	/* If no drivers have overridden us and the user didn't pass a
793 	   boot option, default to displaying the cursor */
794 	if (global_cursor_default == -1)
795 		global_cursor_default = 1;
796 
797 	vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
798 	vcs_make_sysfs(currcons);
799 	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
800 
801 	return 0;
802 err_free:
803 	kfree(vc);
804 	vc_cons[currcons].d = NULL;
805 	return -ENOMEM;
806 }
807 
808 static inline int resize_screen(struct vc_data *vc, int width, int height,
809 				int user)
810 {
811 	/* Resizes the resolution of the display adapater */
812 	int err = 0;
813 
814 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
815 		err = vc->vc_sw->con_resize(vc, width, height, user);
816 
817 	return err;
818 }
819 
820 /*
821  * Change # of rows and columns (0 means unchanged/the size of fg_console)
822  * [this is to be used together with some user program
823  * like resize that changes the hardware videomode]
824  */
825 #define VC_RESIZE_MAXCOL (32767)
826 #define VC_RESIZE_MAXROW (32767)
827 
828 /**
829  *	vc_do_resize	-	resizing method for the tty
830  *	@tty: tty being resized
831  *	@real_tty: real tty (different to tty if a pty/tty pair)
832  *	@vc: virtual console private data
833  *	@cols: columns
834  *	@lines: lines
835  *
836  *	Resize a virtual console, clipping according to the actual constraints.
837  *	If the caller passes a tty structure then update the termios winsize
838  *	information and perform any necessary signal handling.
839  *
840  *	Caller must hold the console semaphore. Takes the termios rwsem and
841  *	ctrl_lock of the tty IFF a tty is passed.
842  */
843 
844 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
845 				unsigned int cols, unsigned int lines)
846 {
847 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
848 	unsigned long end;
849 	unsigned int old_rows, old_row_size;
850 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
851 	unsigned int user;
852 	unsigned short *newscreen;
853 
854 	WARN_CONSOLE_UNLOCKED();
855 
856 	if (!vc)
857 		return -ENXIO;
858 
859 	user = vc->vc_resize_user;
860 	vc->vc_resize_user = 0;
861 
862 	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
863 		return -EINVAL;
864 
865 	new_cols = (cols ? cols : vc->vc_cols);
866 	new_rows = (lines ? lines : vc->vc_rows);
867 	new_row_size = new_cols << 1;
868 	new_screen_size = new_row_size * new_rows;
869 
870 	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
871 		return 0;
872 
873 	newscreen = kmalloc(new_screen_size, GFP_USER);
874 	if (!newscreen)
875 		return -ENOMEM;
876 
877 	old_rows = vc->vc_rows;
878 	old_row_size = vc->vc_size_row;
879 
880 	err = resize_screen(vc, new_cols, new_rows, user);
881 	if (err) {
882 		kfree(newscreen);
883 		return err;
884 	}
885 
886 	vc->vc_rows = new_rows;
887 	vc->vc_cols = new_cols;
888 	vc->vc_size_row = new_row_size;
889 	vc->vc_screenbuf_size = new_screen_size;
890 
891 	rlth = min(old_row_size, new_row_size);
892 	rrem = new_row_size - rlth;
893 	old_origin = vc->vc_origin;
894 	new_origin = (long) newscreen;
895 	new_scr_end = new_origin + new_screen_size;
896 
897 	if (vc->vc_y > new_rows) {
898 		if (old_rows - vc->vc_y < new_rows) {
899 			/*
900 			 * Cursor near the bottom, copy contents from the
901 			 * bottom of buffer
902 			 */
903 			old_origin += (old_rows - new_rows) * old_row_size;
904 		} else {
905 			/*
906 			 * Cursor is in no man's land, copy 1/2 screenful
907 			 * from the top and bottom of cursor position
908 			 */
909 			old_origin += (vc->vc_y - new_rows/2) * old_row_size;
910 		}
911 	}
912 
913 	end = old_origin + old_row_size * min(old_rows, new_rows);
914 
915 	update_attr(vc);
916 
917 	while (old_origin < end) {
918 		scr_memcpyw((unsigned short *) new_origin,
919 			    (unsigned short *) old_origin, rlth);
920 		if (rrem)
921 			scr_memsetw((void *)(new_origin + rlth),
922 				    vc->vc_video_erase_char, rrem);
923 		old_origin += old_row_size;
924 		new_origin += new_row_size;
925 	}
926 	if (new_scr_end > new_origin)
927 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
928 			    new_scr_end - new_origin);
929 	kfree(vc->vc_screenbuf);
930 	vc->vc_screenbuf = newscreen;
931 	vc->vc_screenbuf_size = new_screen_size;
932 	set_origin(vc);
933 
934 	/* do part of a reset_terminal() */
935 	vc->vc_top = 0;
936 	vc->vc_bottom = vc->vc_rows;
937 	gotoxy(vc, vc->vc_x, vc->vc_y);
938 	save_cur(vc);
939 
940 	if (tty) {
941 		/* Rewrite the requested winsize data with the actual
942 		   resulting sizes */
943 		struct winsize ws;
944 		memset(&ws, 0, sizeof(ws));
945 		ws.ws_row = vc->vc_rows;
946 		ws.ws_col = vc->vc_cols;
947 		ws.ws_ypixel = vc->vc_scan_lines;
948 		tty_do_resize(tty, &ws);
949 	}
950 
951 	if (con_is_visible(vc))
952 		update_screen(vc);
953 	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
954 	return err;
955 }
956 
957 /**
958  *	vc_resize		-	resize a VT
959  *	@vc: virtual console
960  *	@cols: columns
961  *	@rows: rows
962  *
963  *	Resize a virtual console as seen from the console end of things. We
964  *	use the common vc_do_resize methods to update the structures. The
965  *	caller must hold the console sem to protect console internals and
966  *	vc->port.tty
967  */
968 
969 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
970 {
971 	return vc_do_resize(vc->port.tty, vc, cols, rows);
972 }
973 
974 /**
975  *	vt_resize		-	resize a VT
976  *	@tty: tty to resize
977  *	@ws: winsize attributes
978  *
979  *	Resize a virtual terminal. This is called by the tty layer as we
980  *	register our own handler for resizing. The mutual helper does all
981  *	the actual work.
982  *
983  *	Takes the console sem and the called methods then take the tty
984  *	termios_rwsem and the tty ctrl_lock in that order.
985  */
986 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
987 {
988 	struct vc_data *vc = tty->driver_data;
989 	int ret;
990 
991 	console_lock();
992 	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
993 	console_unlock();
994 	return ret;
995 }
996 
997 struct vc_data *vc_deallocate(unsigned int currcons)
998 {
999 	struct vc_data *vc = NULL;
1000 
1001 	WARN_CONSOLE_UNLOCKED();
1002 
1003 	if (vc_cons_allocated(currcons)) {
1004 		struct vt_notifier_param param;
1005 
1006 		param.vc = vc = vc_cons[currcons].d;
1007 		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1008 		vcs_remove_sysfs(currcons);
1009 		vc->vc_sw->con_deinit(vc);
1010 		put_pid(vc->vt_pid);
1011 		module_put(vc->vc_sw->owner);
1012 		kfree(vc->vc_screenbuf);
1013 		vc_cons[currcons].d = NULL;
1014 	}
1015 	return vc;
1016 }
1017 
1018 /*
1019  *	VT102 emulator
1020  */
1021 
1022 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1023 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1024 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1025 
1026 #define decarm		VC_REPEAT
1027 #define decckm		VC_CKMODE
1028 #define kbdapplic	VC_APPLIC
1029 #define lnm		VC_CRLF
1030 
1031 /*
1032  * this is what the terminal answers to a ESC-Z or csi0c query.
1033  */
1034 #define VT100ID "\033[?1;2c"
1035 #define VT102ID "\033[?6c"
1036 
1037 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1038 				       8,12,10,14, 9,13,11,15 };
1039 
1040 /* the default colour table, for VGA+ colour systems */
1041 unsigned char default_red[] = {
1042 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1043 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1044 };
1045 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1046 
1047 unsigned char default_grn[] = {
1048 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1049 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1050 };
1051 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1052 
1053 unsigned char default_blu[] = {
1054 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1055 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1056 };
1057 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1058 
1059 /*
1060  * gotoxy() must verify all boundaries, because the arguments
1061  * might also be negative. If the given position is out of
1062  * bounds, the cursor is placed at the nearest margin.
1063  */
1064 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1065 {
1066 	int min_y, max_y;
1067 
1068 	if (new_x < 0)
1069 		vc->vc_x = 0;
1070 	else {
1071 		if (new_x >= vc->vc_cols)
1072 			vc->vc_x = vc->vc_cols - 1;
1073 		else
1074 			vc->vc_x = new_x;
1075 	}
1076 
1077  	if (vc->vc_decom) {
1078 		min_y = vc->vc_top;
1079 		max_y = vc->vc_bottom;
1080 	} else {
1081 		min_y = 0;
1082 		max_y = vc->vc_rows;
1083 	}
1084 	if (new_y < min_y)
1085 		vc->vc_y = min_y;
1086 	else if (new_y >= max_y)
1087 		vc->vc_y = max_y - 1;
1088 	else
1089 		vc->vc_y = new_y;
1090 	vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
1091 	vc->vc_need_wrap = 0;
1092 }
1093 
1094 /* for absolute user moves, when decom is set */
1095 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1096 {
1097 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1098 }
1099 
1100 void scrollback(struct vc_data *vc)
1101 {
1102 	scrolldelta(-(vc->vc_rows / 2));
1103 }
1104 
1105 void scrollfront(struct vc_data *vc, int lines)
1106 {
1107 	if (!lines)
1108 		lines = vc->vc_rows / 2;
1109 	scrolldelta(lines);
1110 }
1111 
1112 static void lf(struct vc_data *vc)
1113 {
1114     	/* don't scroll if above bottom of scrolling region, or
1115 	 * if below scrolling region
1116 	 */
1117     	if (vc->vc_y + 1 == vc->vc_bottom)
1118 		scrup(vc, vc->vc_top, vc->vc_bottom, 1);
1119 	else if (vc->vc_y < vc->vc_rows - 1) {
1120 	    	vc->vc_y++;
1121 		vc->vc_pos += vc->vc_size_row;
1122 	}
1123 	vc->vc_need_wrap = 0;
1124 	notify_write(vc, '\n');
1125 }
1126 
1127 static void ri(struct vc_data *vc)
1128 {
1129     	/* don't scroll if below top of scrolling region, or
1130 	 * if above scrolling region
1131 	 */
1132 	if (vc->vc_y == vc->vc_top)
1133 		scrdown(vc, vc->vc_top, vc->vc_bottom, 1);
1134 	else if (vc->vc_y > 0) {
1135 		vc->vc_y--;
1136 		vc->vc_pos -= vc->vc_size_row;
1137 	}
1138 	vc->vc_need_wrap = 0;
1139 }
1140 
1141 static inline void cr(struct vc_data *vc)
1142 {
1143 	vc->vc_pos -= vc->vc_x << 1;
1144 	vc->vc_need_wrap = vc->vc_x = 0;
1145 	notify_write(vc, '\r');
1146 }
1147 
1148 static inline void bs(struct vc_data *vc)
1149 {
1150 	if (vc->vc_x) {
1151 		vc->vc_pos -= 2;
1152 		vc->vc_x--;
1153 		vc->vc_need_wrap = 0;
1154 		notify_write(vc, '\b');
1155 	}
1156 }
1157 
1158 static inline void del(struct vc_data *vc)
1159 {
1160 	/* ignored */
1161 }
1162 
1163 static void csi_J(struct vc_data *vc, int vpar)
1164 {
1165 	unsigned int count;
1166 	unsigned short * start;
1167 
1168 	switch (vpar) {
1169 		case 0:	/* erase from cursor to end of display */
1170 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1171 			start = (unsigned short *)vc->vc_pos;
1172 			break;
1173 		case 1:	/* erase from start to cursor */
1174 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1175 			start = (unsigned short *)vc->vc_origin;
1176 			break;
1177 		case 3: /* erase scroll-back buffer (and whole display) */
1178 			scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
1179 				    vc->vc_screenbuf_size >> 1);
1180 			set_origin(vc);
1181 			if (con_is_visible(vc))
1182 				update_screen(vc);
1183 			/* fall through */
1184 		case 2: /* erase whole display */
1185 			count = vc->vc_cols * vc->vc_rows;
1186 			start = (unsigned short *)vc->vc_origin;
1187 			break;
1188 		default:
1189 			return;
1190 	}
1191 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1192 	if (con_should_update(vc))
1193 		do_update_region(vc, (unsigned long) start, count);
1194 	vc->vc_need_wrap = 0;
1195 }
1196 
1197 static void csi_K(struct vc_data *vc, int vpar)
1198 {
1199 	unsigned int count;
1200 	unsigned short * start;
1201 
1202 	switch (vpar) {
1203 		case 0:	/* erase from cursor to end of line */
1204 			count = vc->vc_cols - vc->vc_x;
1205 			start = (unsigned short *)vc->vc_pos;
1206 			break;
1207 		case 1:	/* erase from start of line to cursor */
1208 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1209 			count = vc->vc_x + 1;
1210 			break;
1211 		case 2: /* erase whole line */
1212 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1213 			count = vc->vc_cols;
1214 			break;
1215 		default:
1216 			return;
1217 	}
1218 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1219 	vc->vc_need_wrap = 0;
1220 	if (con_should_update(vc))
1221 		do_update_region(vc, (unsigned long) start, count);
1222 }
1223 
1224 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1225 {					  /* not vt100? */
1226 	int count;
1227 
1228 	if (!vpar)
1229 		vpar++;
1230 	count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
1231 
1232 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1233 	if (con_should_update(vc))
1234 		vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
1235 	vc->vc_need_wrap = 0;
1236 }
1237 
1238 static void default_attr(struct vc_data *vc)
1239 {
1240 	vc->vc_intensity = 1;
1241 	vc->vc_italic = 0;
1242 	vc->vc_underline = 0;
1243 	vc->vc_reverse = 0;
1244 	vc->vc_blink = 0;
1245 	vc->vc_color = vc->vc_def_color;
1246 }
1247 
1248 struct rgb { u8 r; u8 g; u8 b; };
1249 
1250 static void rgb_from_256(int i, struct rgb *c)
1251 {
1252 	if (i < 8) {            /* Standard colours. */
1253 		c->r = i&1 ? 0xaa : 0x00;
1254 		c->g = i&2 ? 0xaa : 0x00;
1255 		c->b = i&4 ? 0xaa : 0x00;
1256 	} else if (i < 16) {
1257 		c->r = i&1 ? 0xff : 0x55;
1258 		c->g = i&2 ? 0xff : 0x55;
1259 		c->b = i&4 ? 0xff : 0x55;
1260 	} else if (i < 232) {   /* 6x6x6 colour cube. */
1261 		c->r = (i - 16) / 36 * 85 / 2;
1262 		c->g = (i - 16) / 6 % 6 * 85 / 2;
1263 		c->b = (i - 16) % 6 * 85 / 2;
1264 	} else                  /* Grayscale ramp. */
1265 		c->r = c->g = c->b = i * 10 - 2312;
1266 }
1267 
1268 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1269 {
1270 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1271 
1272 	if (c->r > max / 2)
1273 		hue |= 4;
1274 	if (c->g > max / 2)
1275 		hue |= 2;
1276 	if (c->b > max / 2)
1277 		hue |= 1;
1278 
1279 	if (hue == 7 && max <= 0x55) {
1280 		hue = 0;
1281 		vc->vc_intensity = 2;
1282 	} else if (max > 0xaa)
1283 		vc->vc_intensity = 2;
1284 	else
1285 		vc->vc_intensity = 1;
1286 
1287 	vc->vc_color = (vc->vc_color & 0xf0) | hue;
1288 }
1289 
1290 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1291 {
1292 	/* For backgrounds, err on the dark side. */
1293 	vc->vc_color = (vc->vc_color & 0x0f)
1294 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1295 }
1296 
1297 /*
1298  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1299  * and thus need to be detected and ignored by hand. Strictly speaking, that
1300  * standard also wants : rather than ; as separators, contrary to ECMA-48, but
1301  * no one produces such codes and almost no one accepts them.
1302  *
1303  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1304  * supporting them.
1305  */
1306 static int vc_t416_color(struct vc_data *vc, int i,
1307 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1308 {
1309 	struct rgb c;
1310 
1311 	i++;
1312 	if (i > vc->vc_npar)
1313 		return i;
1314 
1315 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1316 		/* 256 colours */
1317 		i++;
1318 		rgb_from_256(vc->vc_par[i], &c);
1319 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1320 		/* 24 bit */
1321 		c.r = vc->vc_par[i + 1];
1322 		c.g = vc->vc_par[i + 2];
1323 		c.b = vc->vc_par[i + 3];
1324 		i += 3;
1325 	} else
1326 		return i;
1327 
1328 	set_color(vc, &c);
1329 
1330 	return i;
1331 }
1332 
1333 /* console_lock is held */
1334 static void csi_m(struct vc_data *vc)
1335 {
1336 	int i;
1337 
1338 	for (i = 0; i <= vc->vc_npar; i++)
1339 		switch (vc->vc_par[i]) {
1340 		case 0:	/* all attributes off */
1341 			default_attr(vc);
1342 			break;
1343 		case 1:
1344 			vc->vc_intensity = 2;
1345 			break;
1346 		case 2:
1347 			vc->vc_intensity = 0;
1348 			break;
1349 		case 3:
1350 			vc->vc_italic = 1;
1351 			break;
1352 		case 4:
1353 			vc->vc_underline = 1;
1354 			break;
1355 		case 5:
1356 			vc->vc_blink = 1;
1357 			break;
1358 		case 7:
1359 			vc->vc_reverse = 1;
1360 			break;
1361 		case 10: /* ANSI X3.64-1979 (SCO-ish?)
1362 			  * Select primary font, don't display control chars if
1363 			  * defined, don't set bit 8 on output.
1364 			  */
1365 			vc->vc_translate = set_translate(vc->vc_charset == 0
1366 					? vc->vc_G0_charset
1367 					: vc->vc_G1_charset, vc);
1368 			vc->vc_disp_ctrl = 0;
1369 			vc->vc_toggle_meta = 0;
1370 			break;
1371 		case 11: /* ANSI X3.64-1979 (SCO-ish?)
1372 			  * Select first alternate font, lets chars < 32 be
1373 			  * displayed as ROM chars.
1374 			  */
1375 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1376 			vc->vc_disp_ctrl = 1;
1377 			vc->vc_toggle_meta = 0;
1378 			break;
1379 		case 12: /* ANSI X3.64-1979 (SCO-ish?)
1380 			  * Select second alternate font, toggle high bit
1381 			  * before displaying as ROM char.
1382 			  */
1383 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1384 			vc->vc_disp_ctrl = 1;
1385 			vc->vc_toggle_meta = 1;
1386 			break;
1387 		case 21:
1388 		case 22:
1389 			vc->vc_intensity = 1;
1390 			break;
1391 		case 23:
1392 			vc->vc_italic = 0;
1393 			break;
1394 		case 24:
1395 			vc->vc_underline = 0;
1396 			break;
1397 		case 25:
1398 			vc->vc_blink = 0;
1399 			break;
1400 		case 27:
1401 			vc->vc_reverse = 0;
1402 			break;
1403 		case 38:
1404 			i = vc_t416_color(vc, i, rgb_foreground);
1405 			break;
1406 		case 48:
1407 			i = vc_t416_color(vc, i, rgb_background);
1408 			break;
1409 		case 39:
1410 			vc->vc_color = (vc->vc_def_color & 0x0f) |
1411 				(vc->vc_color & 0xf0);
1412 			break;
1413 		case 49:
1414 			vc->vc_color = (vc->vc_def_color & 0xf0) |
1415 				(vc->vc_color & 0x0f);
1416 			break;
1417 		default:
1418 			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1419 				if (vc->vc_par[i] < 100)
1420 					vc->vc_intensity = 2;
1421 				vc->vc_par[i] -= 60;
1422 			}
1423 			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1424 				vc->vc_color = color_table[vc->vc_par[i] - 30]
1425 					| (vc->vc_color & 0xf0);
1426 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1427 				vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1428 					| (vc->vc_color & 0x0f);
1429 			break;
1430 		}
1431 	update_attr(vc);
1432 }
1433 
1434 static void respond_string(const char *p, struct tty_port *port)
1435 {
1436 	while (*p) {
1437 		tty_insert_flip_char(port, *p, 0);
1438 		p++;
1439 	}
1440 	tty_schedule_flip(port);
1441 }
1442 
1443 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1444 {
1445 	char buf[40];
1446 
1447 	sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1448 	respond_string(buf, tty->port);
1449 }
1450 
1451 static inline void status_report(struct tty_struct *tty)
1452 {
1453 	respond_string("\033[0n", tty->port);	/* Terminal ok */
1454 }
1455 
1456 static inline void respond_ID(struct tty_struct *tty)
1457 {
1458 	respond_string(VT102ID, tty->port);
1459 }
1460 
1461 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1462 {
1463 	char buf[8];
1464 
1465 	sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1466 		(char)('!' + mry));
1467 	respond_string(buf, tty->port);
1468 }
1469 
1470 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1471 int mouse_reporting(void)
1472 {
1473 	return vc_cons[fg_console].d->vc_report_mouse;
1474 }
1475 
1476 /* console_lock is held */
1477 static void set_mode(struct vc_data *vc, int on_off)
1478 {
1479 	int i;
1480 
1481 	for (i = 0; i <= vc->vc_npar; i++)
1482 		if (vc->vc_ques) {
1483 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1484 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1485 				if (on_off)
1486 					set_kbd(vc, decckm);
1487 				else
1488 					clr_kbd(vc, decckm);
1489 				break;
1490 			case 3:	/* 80/132 mode switch unimplemented */
1491 #if 0
1492 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1493 				/* this alone does not suffice; some user mode
1494 				   utility has to change the hardware regs */
1495 #endif
1496 				break;
1497 			case 5:			/* Inverted screen on/off */
1498 				if (vc->vc_decscnm != on_off) {
1499 					vc->vc_decscnm = on_off;
1500 					invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1501 					update_attr(vc);
1502 				}
1503 				break;
1504 			case 6:			/* Origin relative/absolute */
1505 				vc->vc_decom = on_off;
1506 				gotoxay(vc, 0, 0);
1507 				break;
1508 			case 7:			/* Autowrap on/off */
1509 				vc->vc_decawm = on_off;
1510 				break;
1511 			case 8:			/* Autorepeat on/off */
1512 				if (on_off)
1513 					set_kbd(vc, decarm);
1514 				else
1515 					clr_kbd(vc, decarm);
1516 				break;
1517 			case 9:
1518 				vc->vc_report_mouse = on_off ? 1 : 0;
1519 				break;
1520 			case 25:		/* Cursor on/off */
1521 				vc->vc_deccm = on_off;
1522 				break;
1523 			case 1000:
1524 				vc->vc_report_mouse = on_off ? 2 : 0;
1525 				break;
1526 			}
1527 		} else {
1528 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1529 			case 3:			/* Monitor (display ctrls) */
1530 				vc->vc_disp_ctrl = on_off;
1531 				break;
1532 			case 4:			/* Insert Mode on/off */
1533 				vc->vc_decim = on_off;
1534 				break;
1535 			case 20:		/* Lf, Enter == CrLf/Lf */
1536 				if (on_off)
1537 					set_kbd(vc, lnm);
1538 				else
1539 					clr_kbd(vc, lnm);
1540 				break;
1541 			}
1542 		}
1543 }
1544 
1545 /* console_lock is held */
1546 static void setterm_command(struct vc_data *vc)
1547 {
1548 	switch(vc->vc_par[0]) {
1549 		case 1:	/* set color for underline mode */
1550 			if (vc->vc_can_do_color &&
1551 					vc->vc_par[1] < 16) {
1552 				vc->vc_ulcolor = color_table[vc->vc_par[1]];
1553 				if (vc->vc_underline)
1554 					update_attr(vc);
1555 			}
1556 			break;
1557 		case 2:	/* set color for half intensity mode */
1558 			if (vc->vc_can_do_color &&
1559 					vc->vc_par[1] < 16) {
1560 				vc->vc_halfcolor = color_table[vc->vc_par[1]];
1561 				if (vc->vc_intensity == 0)
1562 					update_attr(vc);
1563 			}
1564 			break;
1565 		case 8:	/* store colors as defaults */
1566 			vc->vc_def_color = vc->vc_attr;
1567 			if (vc->vc_hi_font_mask == 0x100)
1568 				vc->vc_def_color >>= 1;
1569 			default_attr(vc);
1570 			update_attr(vc);
1571 			break;
1572 		case 9:	/* set blanking interval */
1573 			blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1574 			poke_blanked_console();
1575 			break;
1576 		case 10: /* set bell frequency in Hz */
1577 			if (vc->vc_npar >= 1)
1578 				vc->vc_bell_pitch = vc->vc_par[1];
1579 			else
1580 				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1581 			break;
1582 		case 11: /* set bell duration in msec */
1583 			if (vc->vc_npar >= 1)
1584 				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1585 					msecs_to_jiffies(vc->vc_par[1]) : 0;
1586 			else
1587 				vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1588 			break;
1589 		case 12: /* bring specified console to the front */
1590 			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1591 				set_console(vc->vc_par[1] - 1);
1592 			break;
1593 		case 13: /* unblank the screen */
1594 			poke_blanked_console();
1595 			break;
1596 		case 14: /* set vesa powerdown interval */
1597 			vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1598 			break;
1599 		case 15: /* activate the previous console */
1600 			set_console(last_console);
1601 			break;
1602 		case 16: /* set cursor blink duration in msec */
1603 			if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1604 					vc->vc_par[1] <= USHRT_MAX)
1605 				vc->vc_cur_blink_ms = vc->vc_par[1];
1606 			else
1607 				vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1608 			break;
1609 	}
1610 }
1611 
1612 /* console_lock is held */
1613 static void csi_at(struct vc_data *vc, unsigned int nr)
1614 {
1615 	if (nr > vc->vc_cols - vc->vc_x)
1616 		nr = vc->vc_cols - vc->vc_x;
1617 	else if (!nr)
1618 		nr = 1;
1619 	insert_char(vc, nr);
1620 }
1621 
1622 /* console_lock is held */
1623 static void csi_L(struct vc_data *vc, unsigned int nr)
1624 {
1625 	if (nr > vc->vc_rows - vc->vc_y)
1626 		nr = vc->vc_rows - vc->vc_y;
1627 	else if (!nr)
1628 		nr = 1;
1629 	scrdown(vc, vc->vc_y, vc->vc_bottom, nr);
1630 	vc->vc_need_wrap = 0;
1631 }
1632 
1633 /* console_lock is held */
1634 static void csi_P(struct vc_data *vc, unsigned int nr)
1635 {
1636 	if (nr > vc->vc_cols - vc->vc_x)
1637 		nr = vc->vc_cols - vc->vc_x;
1638 	else if (!nr)
1639 		nr = 1;
1640 	delete_char(vc, nr);
1641 }
1642 
1643 /* console_lock is held */
1644 static void csi_M(struct vc_data *vc, unsigned int nr)
1645 {
1646 	if (nr > vc->vc_rows - vc->vc_y)
1647 		nr = vc->vc_rows - vc->vc_y;
1648 	else if (!nr)
1649 		nr=1;
1650 	scrup(vc, vc->vc_y, vc->vc_bottom, nr);
1651 	vc->vc_need_wrap = 0;
1652 }
1653 
1654 /* console_lock is held (except via vc_init->reset_terminal */
1655 static void save_cur(struct vc_data *vc)
1656 {
1657 	vc->vc_saved_x		= vc->vc_x;
1658 	vc->vc_saved_y		= vc->vc_y;
1659 	vc->vc_s_intensity	= vc->vc_intensity;
1660 	vc->vc_s_italic         = vc->vc_italic;
1661 	vc->vc_s_underline	= vc->vc_underline;
1662 	vc->vc_s_blink		= vc->vc_blink;
1663 	vc->vc_s_reverse	= vc->vc_reverse;
1664 	vc->vc_s_charset	= vc->vc_charset;
1665 	vc->vc_s_color		= vc->vc_color;
1666 	vc->vc_saved_G0		= vc->vc_G0_charset;
1667 	vc->vc_saved_G1		= vc->vc_G1_charset;
1668 }
1669 
1670 /* console_lock is held */
1671 static void restore_cur(struct vc_data *vc)
1672 {
1673 	gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
1674 	vc->vc_intensity	= vc->vc_s_intensity;
1675 	vc->vc_italic		= vc->vc_s_italic;
1676 	vc->vc_underline	= vc->vc_s_underline;
1677 	vc->vc_blink		= vc->vc_s_blink;
1678 	vc->vc_reverse		= vc->vc_s_reverse;
1679 	vc->vc_charset		= vc->vc_s_charset;
1680 	vc->vc_color		= vc->vc_s_color;
1681 	vc->vc_G0_charset	= vc->vc_saved_G0;
1682 	vc->vc_G1_charset	= vc->vc_saved_G1;
1683 	vc->vc_translate	= set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
1684 	update_attr(vc);
1685 	vc->vc_need_wrap = 0;
1686 }
1687 
1688 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
1689 	EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
1690 	ESpalette, ESosc };
1691 
1692 /* console_lock is held (except via vc_init()) */
1693 static void reset_terminal(struct vc_data *vc, int do_clear)
1694 {
1695 	vc->vc_top		= 0;
1696 	vc->vc_bottom		= vc->vc_rows;
1697 	vc->vc_state		= ESnormal;
1698 	vc->vc_ques		= 0;
1699 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
1700 	vc->vc_G0_charset	= LAT1_MAP;
1701 	vc->vc_G1_charset	= GRAF_MAP;
1702 	vc->vc_charset		= 0;
1703 	vc->vc_need_wrap	= 0;
1704 	vc->vc_report_mouse	= 0;
1705 	vc->vc_utf              = default_utf8;
1706 	vc->vc_utf_count	= 0;
1707 
1708 	vc->vc_disp_ctrl	= 0;
1709 	vc->vc_toggle_meta	= 0;
1710 
1711 	vc->vc_decscnm		= 0;
1712 	vc->vc_decom		= 0;
1713 	vc->vc_decawm		= 1;
1714 	vc->vc_deccm		= global_cursor_default;
1715 	vc->vc_decim		= 0;
1716 
1717 	vt_reset_keyboard(vc->vc_num);
1718 
1719 	vc->vc_cursor_type = cur_default;
1720 	vc->vc_complement_mask = vc->vc_s_complement_mask;
1721 
1722 	default_attr(vc);
1723 	update_attr(vc);
1724 
1725 	vc->vc_tab_stop[0]	= 0x01010100;
1726 	vc->vc_tab_stop[1]	=
1727 	vc->vc_tab_stop[2]	=
1728 	vc->vc_tab_stop[3]	=
1729 	vc->vc_tab_stop[4]	=
1730 	vc->vc_tab_stop[5]	=
1731 	vc->vc_tab_stop[6]	=
1732 	vc->vc_tab_stop[7]	= 0x01010101;
1733 
1734 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1735 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1736 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1737 
1738 	gotoxy(vc, 0, 0);
1739 	save_cur(vc);
1740 	if (do_clear)
1741 	    csi_J(vc, 2);
1742 }
1743 
1744 /* console_lock is held */
1745 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
1746 {
1747 	/*
1748 	 *  Control characters can be used in the _middle_
1749 	 *  of an escape sequence.
1750 	 */
1751 	if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
1752 		return;
1753 	switch (c) {
1754 	case 0:
1755 		return;
1756 	case 7:
1757 		if (vc->vc_state == ESosc)
1758 			vc->vc_state = ESnormal;
1759 		else if (vc->vc_bell_duration)
1760 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
1761 		return;
1762 	case 8:
1763 		bs(vc);
1764 		return;
1765 	case 9:
1766 		vc->vc_pos -= (vc->vc_x << 1);
1767 		while (vc->vc_x < vc->vc_cols - 1) {
1768 			vc->vc_x++;
1769 			if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
1770 				break;
1771 		}
1772 		vc->vc_pos += (vc->vc_x << 1);
1773 		notify_write(vc, '\t');
1774 		return;
1775 	case 10: case 11: case 12:
1776 		lf(vc);
1777 		if (!is_kbd(vc, lnm))
1778 			return;
1779 	case 13:
1780 		cr(vc);
1781 		return;
1782 	case 14:
1783 		vc->vc_charset = 1;
1784 		vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
1785 		vc->vc_disp_ctrl = 1;
1786 		return;
1787 	case 15:
1788 		vc->vc_charset = 0;
1789 		vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
1790 		vc->vc_disp_ctrl = 0;
1791 		return;
1792 	case 24: case 26:
1793 		vc->vc_state = ESnormal;
1794 		return;
1795 	case 27:
1796 		vc->vc_state = ESesc;
1797 		return;
1798 	case 127:
1799 		del(vc);
1800 		return;
1801 	case 128+27:
1802 		vc->vc_state = ESsquare;
1803 		return;
1804 	}
1805 	switch(vc->vc_state) {
1806 	case ESesc:
1807 		vc->vc_state = ESnormal;
1808 		switch (c) {
1809 		case '[':
1810 			vc->vc_state = ESsquare;
1811 			return;
1812 		case ']':
1813 			vc->vc_state = ESnonstd;
1814 			return;
1815 		case '%':
1816 			vc->vc_state = ESpercent;
1817 			return;
1818 		case 'E':
1819 			cr(vc);
1820 			lf(vc);
1821 			return;
1822 		case 'M':
1823 			ri(vc);
1824 			return;
1825 		case 'D':
1826 			lf(vc);
1827 			return;
1828 		case 'H':
1829 			vc->vc_tab_stop[vc->vc_x >> 5] |= (1 << (vc->vc_x & 31));
1830 			return;
1831 		case 'Z':
1832 			respond_ID(tty);
1833 			return;
1834 		case '7':
1835 			save_cur(vc);
1836 			return;
1837 		case '8':
1838 			restore_cur(vc);
1839 			return;
1840 		case '(':
1841 			vc->vc_state = ESsetG0;
1842 			return;
1843 		case ')':
1844 			vc->vc_state = ESsetG1;
1845 			return;
1846 		case '#':
1847 			vc->vc_state = EShash;
1848 			return;
1849 		case 'c':
1850 			reset_terminal(vc, 1);
1851 			return;
1852 		case '>':  /* Numeric keypad */
1853 			clr_kbd(vc, kbdapplic);
1854 			return;
1855 		case '=':  /* Appl. keypad */
1856 			set_kbd(vc, kbdapplic);
1857 			return;
1858 		}
1859 		return;
1860 	case ESnonstd:
1861 		if (c=='P') {   /* palette escape sequence */
1862 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1863 				vc->vc_par[vc->vc_npar] = 0;
1864 			vc->vc_npar = 0;
1865 			vc->vc_state = ESpalette;
1866 			return;
1867 		} else if (c=='R') {   /* reset palette */
1868 			reset_palette(vc);
1869 			vc->vc_state = ESnormal;
1870 		} else if (c>='0' && c<='9')
1871 			vc->vc_state = ESosc;
1872 		else
1873 			vc->vc_state = ESnormal;
1874 		return;
1875 	case ESpalette:
1876 		if (isxdigit(c)) {
1877 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
1878 			if (vc->vc_npar == 7) {
1879 				int i = vc->vc_par[0] * 3, j = 1;
1880 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1881 				vc->vc_palette[i++] += vc->vc_par[j++];
1882 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1883 				vc->vc_palette[i++] += vc->vc_par[j++];
1884 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1885 				vc->vc_palette[i] += vc->vc_par[j];
1886 				set_palette(vc);
1887 				vc->vc_state = ESnormal;
1888 			}
1889 		} else
1890 			vc->vc_state = ESnormal;
1891 		return;
1892 	case ESsquare:
1893 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1894 			vc->vc_par[vc->vc_npar] = 0;
1895 		vc->vc_npar = 0;
1896 		vc->vc_state = ESgetpars;
1897 		if (c == '[') { /* Function key */
1898 			vc->vc_state=ESfunckey;
1899 			return;
1900 		}
1901 		vc->vc_ques = (c == '?');
1902 		if (vc->vc_ques)
1903 			return;
1904 	case ESgetpars:
1905 		if (c == ';' && vc->vc_npar < NPAR - 1) {
1906 			vc->vc_npar++;
1907 			return;
1908 		} else if (c>='0' && c<='9') {
1909 			vc->vc_par[vc->vc_npar] *= 10;
1910 			vc->vc_par[vc->vc_npar] += c - '0';
1911 			return;
1912 		}
1913 		vc->vc_state = ESnormal;
1914 		switch(c) {
1915 		case 'h':
1916 			set_mode(vc, 1);
1917 			return;
1918 		case 'l':
1919 			set_mode(vc, 0);
1920 			return;
1921 		case 'c':
1922 			if (vc->vc_ques) {
1923 				if (vc->vc_par[0])
1924 					vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
1925 				else
1926 					vc->vc_cursor_type = cur_default;
1927 				return;
1928 			}
1929 			break;
1930 		case 'm':
1931 			if (vc->vc_ques) {
1932 				clear_selection();
1933 				if (vc->vc_par[0])
1934 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
1935 				else
1936 					vc->vc_complement_mask = vc->vc_s_complement_mask;
1937 				return;
1938 			}
1939 			break;
1940 		case 'n':
1941 			if (!vc->vc_ques) {
1942 				if (vc->vc_par[0] == 5)
1943 					status_report(tty);
1944 				else if (vc->vc_par[0] == 6)
1945 					cursor_report(vc, tty);
1946 			}
1947 			return;
1948 		}
1949 		if (vc->vc_ques) {
1950 			vc->vc_ques = 0;
1951 			return;
1952 		}
1953 		switch(c) {
1954 		case 'G': case '`':
1955 			if (vc->vc_par[0])
1956 				vc->vc_par[0]--;
1957 			gotoxy(vc, vc->vc_par[0], vc->vc_y);
1958 			return;
1959 		case 'A':
1960 			if (!vc->vc_par[0])
1961 				vc->vc_par[0]++;
1962 			gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
1963 			return;
1964 		case 'B': case 'e':
1965 			if (!vc->vc_par[0])
1966 				vc->vc_par[0]++;
1967 			gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
1968 			return;
1969 		case 'C': case 'a':
1970 			if (!vc->vc_par[0])
1971 				vc->vc_par[0]++;
1972 			gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
1973 			return;
1974 		case 'D':
1975 			if (!vc->vc_par[0])
1976 				vc->vc_par[0]++;
1977 			gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
1978 			return;
1979 		case 'E':
1980 			if (!vc->vc_par[0])
1981 				vc->vc_par[0]++;
1982 			gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
1983 			return;
1984 		case 'F':
1985 			if (!vc->vc_par[0])
1986 				vc->vc_par[0]++;
1987 			gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
1988 			return;
1989 		case 'd':
1990 			if (vc->vc_par[0])
1991 				vc->vc_par[0]--;
1992 			gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
1993 			return;
1994 		case 'H': case 'f':
1995 			if (vc->vc_par[0])
1996 				vc->vc_par[0]--;
1997 			if (vc->vc_par[1])
1998 				vc->vc_par[1]--;
1999 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2000 			return;
2001 		case 'J':
2002 			csi_J(vc, vc->vc_par[0]);
2003 			return;
2004 		case 'K':
2005 			csi_K(vc, vc->vc_par[0]);
2006 			return;
2007 		case 'L':
2008 			csi_L(vc, vc->vc_par[0]);
2009 			return;
2010 		case 'M':
2011 			csi_M(vc, vc->vc_par[0]);
2012 			return;
2013 		case 'P':
2014 			csi_P(vc, vc->vc_par[0]);
2015 			return;
2016 		case 'c':
2017 			if (!vc->vc_par[0])
2018 				respond_ID(tty);
2019 			return;
2020 		case 'g':
2021 			if (!vc->vc_par[0])
2022 				vc->vc_tab_stop[vc->vc_x >> 5] &= ~(1 << (vc->vc_x & 31));
2023 			else if (vc->vc_par[0] == 3) {
2024 				vc->vc_tab_stop[0] =
2025 					vc->vc_tab_stop[1] =
2026 					vc->vc_tab_stop[2] =
2027 					vc->vc_tab_stop[3] =
2028 					vc->vc_tab_stop[4] =
2029 					vc->vc_tab_stop[5] =
2030 					vc->vc_tab_stop[6] =
2031 					vc->vc_tab_stop[7] = 0;
2032 			}
2033 			return;
2034 		case 'm':
2035 			csi_m(vc);
2036 			return;
2037 		case 'q': /* DECLL - but only 3 leds */
2038 			/* map 0,1,2,3 to 0,1,2,4 */
2039 			if (vc->vc_par[0] < 4)
2040 				vt_set_led_state(vc->vc_num,
2041 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2042 			return;
2043 		case 'r':
2044 			if (!vc->vc_par[0])
2045 				vc->vc_par[0]++;
2046 			if (!vc->vc_par[1])
2047 				vc->vc_par[1] = vc->vc_rows;
2048 			/* Minimum allowed region is 2 lines */
2049 			if (vc->vc_par[0] < vc->vc_par[1] &&
2050 			    vc->vc_par[1] <= vc->vc_rows) {
2051 				vc->vc_top = vc->vc_par[0] - 1;
2052 				vc->vc_bottom = vc->vc_par[1];
2053 				gotoxay(vc, 0, 0);
2054 			}
2055 			return;
2056 		case 's':
2057 			save_cur(vc);
2058 			return;
2059 		case 'u':
2060 			restore_cur(vc);
2061 			return;
2062 		case 'X':
2063 			csi_X(vc, vc->vc_par[0]);
2064 			return;
2065 		case '@':
2066 			csi_at(vc, vc->vc_par[0]);
2067 			return;
2068 		case ']': /* setterm functions */
2069 			setterm_command(vc);
2070 			return;
2071 		}
2072 		return;
2073 	case ESpercent:
2074 		vc->vc_state = ESnormal;
2075 		switch (c) {
2076 		case '@':  /* defined in ISO 2022 */
2077 			vc->vc_utf = 0;
2078 			return;
2079 		case 'G':  /* prelim official escape code */
2080 		case '8':  /* retained for compatibility */
2081 			vc->vc_utf = 1;
2082 			return;
2083 		}
2084 		return;
2085 	case ESfunckey:
2086 		vc->vc_state = ESnormal;
2087 		return;
2088 	case EShash:
2089 		vc->vc_state = ESnormal;
2090 		if (c == '8') {
2091 			/* DEC screen alignment test. kludge :-) */
2092 			vc->vc_video_erase_char =
2093 				(vc->vc_video_erase_char & 0xff00) | 'E';
2094 			csi_J(vc, 2);
2095 			vc->vc_video_erase_char =
2096 				(vc->vc_video_erase_char & 0xff00) | ' ';
2097 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2098 		}
2099 		return;
2100 	case ESsetG0:
2101 		if (c == '0')
2102 			vc->vc_G0_charset = GRAF_MAP;
2103 		else if (c == 'B')
2104 			vc->vc_G0_charset = LAT1_MAP;
2105 		else if (c == 'U')
2106 			vc->vc_G0_charset = IBMPC_MAP;
2107 		else if (c == 'K')
2108 			vc->vc_G0_charset = USER_MAP;
2109 		if (vc->vc_charset == 0)
2110 			vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2111 		vc->vc_state = ESnormal;
2112 		return;
2113 	case ESsetG1:
2114 		if (c == '0')
2115 			vc->vc_G1_charset = GRAF_MAP;
2116 		else if (c == 'B')
2117 			vc->vc_G1_charset = LAT1_MAP;
2118 		else if (c == 'U')
2119 			vc->vc_G1_charset = IBMPC_MAP;
2120 		else if (c == 'K')
2121 			vc->vc_G1_charset = USER_MAP;
2122 		if (vc->vc_charset == 1)
2123 			vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2124 		vc->vc_state = ESnormal;
2125 		return;
2126 	case ESosc:
2127 		return;
2128 	default:
2129 		vc->vc_state = ESnormal;
2130 	}
2131 }
2132 
2133 /* is_double_width() is based on the wcwidth() implementation by
2134  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2135  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2136  */
2137 struct interval {
2138 	uint32_t first;
2139 	uint32_t last;
2140 };
2141 
2142 static int bisearch(uint32_t ucs, const struct interval *table, int max)
2143 {
2144 	int min = 0;
2145 	int mid;
2146 
2147 	if (ucs < table[0].first || ucs > table[max].last)
2148 		return 0;
2149 	while (max >= min) {
2150 		mid = (min + max) / 2;
2151 		if (ucs > table[mid].last)
2152 			min = mid + 1;
2153 		else if (ucs < table[mid].first)
2154 			max = mid - 1;
2155 		else
2156 			return 1;
2157 	}
2158 	return 0;
2159 }
2160 
2161 static int is_double_width(uint32_t ucs)
2162 {
2163 	static const struct interval double_width[] = {
2164 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2165 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2166 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2167 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2168 	};
2169 	return bisearch(ucs, double_width, ARRAY_SIZE(double_width) - 1);
2170 }
2171 
2172 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2173 		unsigned long draw_to, int *draw_x)
2174 {
2175 	if (*draw_x < 0)
2176 		return;
2177 
2178 	vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2179 			(u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2180 	*draw_x = -1;
2181 }
2182 
2183 /* acquires console_lock */
2184 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2185 {
2186 	int c, tc, ok, n = 0, draw_x = -1;
2187 	unsigned int currcons;
2188 	unsigned long draw_from = 0, draw_to = 0;
2189 	struct vc_data *vc;
2190 	unsigned char vc_attr;
2191 	struct vt_notifier_param param;
2192 	uint8_t rescan;
2193 	uint8_t inverse;
2194 	uint8_t width;
2195 	u16 himask, charmask;
2196 
2197 	if (in_interrupt())
2198 		return count;
2199 
2200 	might_sleep();
2201 
2202 	console_lock();
2203 	vc = tty->driver_data;
2204 	if (vc == NULL) {
2205 		printk(KERN_ERR "vt: argh, driver_data is NULL !\n");
2206 		console_unlock();
2207 		return 0;
2208 	}
2209 
2210 	currcons = vc->vc_num;
2211 	if (!vc_cons_allocated(currcons)) {
2212 		/* could this happen? */
2213 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2214 		console_unlock();
2215 		return 0;
2216 	}
2217 
2218 	himask = vc->vc_hi_font_mask;
2219 	charmask = himask ? 0x1ff : 0xff;
2220 
2221 	/* undraw cursor first */
2222 	if (con_is_fg(vc))
2223 		hide_cursor(vc);
2224 
2225 	param.vc = vc;
2226 
2227 	while (!tty->stopped && count) {
2228 		int orig = *buf;
2229 		c = orig;
2230 		buf++;
2231 		n++;
2232 		count--;
2233 		rescan = 0;
2234 		inverse = 0;
2235 		width = 1;
2236 
2237 		/* Do no translation at all in control states */
2238 		if (vc->vc_state != ESnormal) {
2239 			tc = c;
2240 		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2241 		    /* Combine UTF-8 into Unicode in vc_utf_char.
2242 		     * vc_utf_count is the number of continuation bytes still
2243 		     * expected to arrive.
2244 		     * vc_npar is the number of continuation bytes arrived so
2245 		     * far
2246 		     */
2247 rescan_last_byte:
2248 		    if ((c & 0xc0) == 0x80) {
2249 			/* Continuation byte received */
2250 			static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2251 			if (vc->vc_utf_count) {
2252 			    vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2253 			    vc->vc_npar++;
2254 			    if (--vc->vc_utf_count) {
2255 				/* Still need some bytes */
2256 				continue;
2257 			    }
2258 			    /* Got a whole character */
2259 			    c = vc->vc_utf_char;
2260 			    /* Reject overlong sequences */
2261 			    if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2262 					c > utf8_length_changes[vc->vc_npar])
2263 				c = 0xfffd;
2264 			} else {
2265 			    /* Unexpected continuation byte */
2266 			    vc->vc_utf_count = 0;
2267 			    c = 0xfffd;
2268 			}
2269 		    } else {
2270 			/* Single ASCII byte or first byte of a sequence received */
2271 			if (vc->vc_utf_count) {
2272 			    /* Continuation byte expected */
2273 			    rescan = 1;
2274 			    vc->vc_utf_count = 0;
2275 			    c = 0xfffd;
2276 			} else if (c > 0x7f) {
2277 			    /* First byte of a multibyte sequence received */
2278 			    vc->vc_npar = 0;
2279 			    if ((c & 0xe0) == 0xc0) {
2280 				vc->vc_utf_count = 1;
2281 				vc->vc_utf_char = (c & 0x1f);
2282 			    } else if ((c & 0xf0) == 0xe0) {
2283 				vc->vc_utf_count = 2;
2284 				vc->vc_utf_char = (c & 0x0f);
2285 			    } else if ((c & 0xf8) == 0xf0) {
2286 				vc->vc_utf_count = 3;
2287 				vc->vc_utf_char = (c & 0x07);
2288 			    } else if ((c & 0xfc) == 0xf8) {
2289 				vc->vc_utf_count = 4;
2290 				vc->vc_utf_char = (c & 0x03);
2291 			    } else if ((c & 0xfe) == 0xfc) {
2292 				vc->vc_utf_count = 5;
2293 				vc->vc_utf_char = (c & 0x01);
2294 			    } else {
2295 				/* 254 and 255 are invalid */
2296 				c = 0xfffd;
2297 			    }
2298 			    if (vc->vc_utf_count) {
2299 				/* Still need some bytes */
2300 				continue;
2301 			    }
2302 			}
2303 			/* Nothing to do if an ASCII byte was received */
2304 		    }
2305 		    /* End of UTF-8 decoding. */
2306 		    /* c is the received character, or U+FFFD for invalid sequences. */
2307 		    /* Replace invalid Unicode code points with U+FFFD too */
2308 		    if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2309 			c = 0xfffd;
2310 		    tc = c;
2311 		} else {	/* no utf or alternate charset mode */
2312 		    tc = vc_translate(vc, c);
2313 		}
2314 
2315 		param.c = tc;
2316 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2317 					&param) == NOTIFY_STOP)
2318 			continue;
2319 
2320                 /* If the original code was a control character we
2321                  * only allow a glyph to be displayed if the code is
2322                  * not normally used (such as for cursor movement) or
2323                  * if the disp_ctrl mode has been explicitly enabled.
2324                  * Certain characters (as given by the CTRL_ALWAYS
2325                  * bitmap) are always displayed as control characters,
2326                  * as the console would be pretty useless without
2327                  * them; to display an arbitrary font position use the
2328                  * direct-to-font zone in UTF-8 mode.
2329                  */
2330                 ok = tc && (c >= 32 ||
2331 			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2332 				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2333 			&& (c != 127 || vc->vc_disp_ctrl)
2334 			&& (c != 128+27);
2335 
2336 		if (vc->vc_state == ESnormal && ok) {
2337 			if (vc->vc_utf && !vc->vc_disp_ctrl) {
2338 				if (is_double_width(c))
2339 					width = 2;
2340 			}
2341 			/* Now try to find out how to display it */
2342 			tc = conv_uni_to_pc(vc, tc);
2343 			if (tc & ~charmask) {
2344 				if (tc == -1 || tc == -2) {
2345 				    continue; /* nothing to display */
2346 				}
2347 				/* Glyph not found */
2348 				if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2349 				    /* In legacy mode use the glyph we get by a 1:1 mapping.
2350 				       This would make absolutely no sense with Unicode in mind,
2351 				       but do this for ASCII characters since a font may lack
2352 				       Unicode mapping info and we don't want to end up with
2353 				       having question marks only. */
2354 				    tc = c;
2355 				} else {
2356 				    /* Display U+FFFD. If it's not found, display an inverse question mark. */
2357 				    tc = conv_uni_to_pc(vc, 0xfffd);
2358 				    if (tc < 0) {
2359 					inverse = 1;
2360 					tc = conv_uni_to_pc(vc, '?');
2361 					if (tc < 0) tc = '?';
2362 				    }
2363 				}
2364 			}
2365 
2366 			if (!inverse) {
2367 				vc_attr = vc->vc_attr;
2368 			} else {
2369 				/* invert vc_attr */
2370 				if (!vc->vc_can_do_color) {
2371 					vc_attr = (vc->vc_attr) ^ 0x08;
2372 				} else if (vc->vc_hi_font_mask == 0x100) {
2373 					vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2374 				} else {
2375 					vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2376 				}
2377 				con_flush(vc, draw_from, draw_to, &draw_x);
2378 			}
2379 
2380 			while (1) {
2381 				if (vc->vc_need_wrap || vc->vc_decim)
2382 					con_flush(vc, draw_from, draw_to,
2383 							&draw_x);
2384 				if (vc->vc_need_wrap) {
2385 					cr(vc);
2386 					lf(vc);
2387 				}
2388 				if (vc->vc_decim)
2389 					insert_char(vc, 1);
2390 				scr_writew(himask ?
2391 					     ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2392 					     (vc_attr << 8) + tc,
2393 					   (u16 *) vc->vc_pos);
2394 				if (con_should_update(vc) && draw_x < 0) {
2395 					draw_x = vc->vc_x;
2396 					draw_from = vc->vc_pos;
2397 				}
2398 				if (vc->vc_x == vc->vc_cols - 1) {
2399 					vc->vc_need_wrap = vc->vc_decawm;
2400 					draw_to = vc->vc_pos + 2;
2401 				} else {
2402 					vc->vc_x++;
2403 					draw_to = (vc->vc_pos += 2);
2404 				}
2405 
2406 				if (!--width) break;
2407 
2408 				tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2409 				if (tc < 0) tc = ' ';
2410 			}
2411 			notify_write(vc, c);
2412 
2413 			if (inverse)
2414 				con_flush(vc, draw_from, draw_to, &draw_x);
2415 
2416 			if (rescan) {
2417 				rescan = 0;
2418 				inverse = 0;
2419 				width = 1;
2420 				c = orig;
2421 				goto rescan_last_byte;
2422 			}
2423 			continue;
2424 		}
2425 		con_flush(vc, draw_from, draw_to, &draw_x);
2426 		do_con_trol(tty, vc, orig);
2427 	}
2428 	con_flush(vc, draw_from, draw_to, &draw_x);
2429 	console_conditional_schedule();
2430 	console_unlock();
2431 	notify_update(vc);
2432 	return n;
2433 }
2434 
2435 /*
2436  * This is the console switching callback.
2437  *
2438  * Doing console switching in a process context allows
2439  * us to do the switches asynchronously (needed when we want
2440  * to switch due to a keyboard interrupt).  Synchronization
2441  * with other console code and prevention of re-entrancy is
2442  * ensured with console_lock.
2443  */
2444 static void console_callback(struct work_struct *ignored)
2445 {
2446 	console_lock();
2447 
2448 	if (want_console >= 0) {
2449 		if (want_console != fg_console &&
2450 		    vc_cons_allocated(want_console)) {
2451 			hide_cursor(vc_cons[fg_console].d);
2452 			change_console(vc_cons[want_console].d);
2453 			/* we only changed when the console had already
2454 			   been allocated - a new console is not created
2455 			   in an interrupt routine */
2456 		}
2457 		want_console = -1;
2458 	}
2459 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2460 		do_poke_blanked_console = 0;
2461 		poke_blanked_console();
2462 	}
2463 	if (scrollback_delta) {
2464 		struct vc_data *vc = vc_cons[fg_console].d;
2465 		clear_selection();
2466 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2467 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2468 		scrollback_delta = 0;
2469 	}
2470 	if (blank_timer_expired) {
2471 		do_blank_screen(0);
2472 		blank_timer_expired = 0;
2473 	}
2474 	notify_update(vc_cons[fg_console].d);
2475 
2476 	console_unlock();
2477 }
2478 
2479 int set_console(int nr)
2480 {
2481 	struct vc_data *vc = vc_cons[fg_console].d;
2482 
2483 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
2484 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2485 
2486 		/*
2487 		 * Console switch will fail in console_callback() or
2488 		 * change_console() so there is no point scheduling
2489 		 * the callback
2490 		 *
2491 		 * Existing set_console() users don't check the return
2492 		 * value so this shouldn't break anything
2493 		 */
2494 		return -EINVAL;
2495 	}
2496 
2497 	want_console = nr;
2498 	schedule_console_callback();
2499 
2500 	return 0;
2501 }
2502 
2503 struct tty_driver *console_driver;
2504 
2505 #ifdef CONFIG_VT_CONSOLE
2506 
2507 /**
2508  * vt_kmsg_redirect() - Sets/gets the kernel message console
2509  * @new:	The new virtual terminal number or -1 if the console should stay
2510  * 		unchanged
2511  *
2512  * By default, the kernel messages are always printed on the current virtual
2513  * console. However, the user may modify that default with the
2514  * TIOCL_SETKMSGREDIRECT ioctl call.
2515  *
2516  * This function sets the kernel message console to be @new. It returns the old
2517  * virtual console number. The virtual terminal number 0 (both as parameter and
2518  * return value) means no redirection (i.e. always printed on the currently
2519  * active console).
2520  *
2521  * The parameter -1 means that only the current console is returned, but the
2522  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2523  * case to make the code more understandable.
2524  *
2525  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2526  * the parameter and always returns 0.
2527  */
2528 int vt_kmsg_redirect(int new)
2529 {
2530 	static int kmsg_con;
2531 
2532 	if (new != -1)
2533 		return xchg(&kmsg_con, new);
2534 	else
2535 		return kmsg_con;
2536 }
2537 
2538 /*
2539  *	Console on virtual terminal
2540  *
2541  * The console must be locked when we get here.
2542  */
2543 
2544 static void vt_console_print(struct console *co, const char *b, unsigned count)
2545 {
2546 	struct vc_data *vc = vc_cons[fg_console].d;
2547 	unsigned char c;
2548 	static DEFINE_SPINLOCK(printing_lock);
2549 	const ushort *start;
2550 	ushort cnt = 0;
2551 	ushort myx;
2552 	int kmsg_console;
2553 
2554 	/* console busy or not yet initialized */
2555 	if (!printable)
2556 		return;
2557 	if (!spin_trylock(&printing_lock))
2558 		return;
2559 
2560 	kmsg_console = vt_get_kmsg_redirect();
2561 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2562 		vc = vc_cons[kmsg_console - 1].d;
2563 
2564 	/* read `x' only after setting currcons properly (otherwise
2565 	   the `x' macro will read the x of the foreground console). */
2566 	myx = vc->vc_x;
2567 
2568 	if (!vc_cons_allocated(fg_console)) {
2569 		/* impossible */
2570 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2571 		goto quit;
2572 	}
2573 
2574 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
2575 		goto quit;
2576 
2577 	/* undraw cursor first */
2578 	if (con_is_fg(vc))
2579 		hide_cursor(vc);
2580 
2581 	start = (ushort *)vc->vc_pos;
2582 
2583 	/* Contrived structure to try to emulate original need_wrap behaviour
2584 	 * Problems caused when we have need_wrap set on '\n' character */
2585 	while (count--) {
2586 		c = *b++;
2587 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2588 			if (cnt > 0) {
2589 				if (con_is_visible(vc))
2590 					vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2591 				vc->vc_x += cnt;
2592 				if (vc->vc_need_wrap)
2593 					vc->vc_x--;
2594 				cnt = 0;
2595 			}
2596 			if (c == 8) {		/* backspace */
2597 				bs(vc);
2598 				start = (ushort *)vc->vc_pos;
2599 				myx = vc->vc_x;
2600 				continue;
2601 			}
2602 			if (c != 13)
2603 				lf(vc);
2604 			cr(vc);
2605 			start = (ushort *)vc->vc_pos;
2606 			myx = vc->vc_x;
2607 			if (c == 10 || c == 13)
2608 				continue;
2609 		}
2610 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2611 		notify_write(vc, c);
2612 		cnt++;
2613 		if (myx == vc->vc_cols - 1) {
2614 			vc->vc_need_wrap = 1;
2615 			continue;
2616 		}
2617 		vc->vc_pos += 2;
2618 		myx++;
2619 	}
2620 	if (cnt > 0) {
2621 		if (con_is_visible(vc))
2622 			vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2623 		vc->vc_x += cnt;
2624 		if (vc->vc_x == vc->vc_cols) {
2625 			vc->vc_x--;
2626 			vc->vc_need_wrap = 1;
2627 		}
2628 	}
2629 	set_cursor(vc);
2630 	notify_update(vc);
2631 
2632 quit:
2633 	spin_unlock(&printing_lock);
2634 }
2635 
2636 static struct tty_driver *vt_console_device(struct console *c, int *index)
2637 {
2638 	*index = c->index ? c->index-1 : fg_console;
2639 	return console_driver;
2640 }
2641 
2642 static struct console vt_console_driver = {
2643 	.name		= "tty",
2644 	.write		= vt_console_print,
2645 	.device		= vt_console_device,
2646 	.unblank	= unblank_screen,
2647 	.flags		= CON_PRINTBUFFER,
2648 	.index		= -1,
2649 };
2650 #endif
2651 
2652 /*
2653  *	Handling of Linux-specific VC ioctls
2654  */
2655 
2656 /*
2657  * Generally a bit racy with respect to console_lock();.
2658  *
2659  * There are some functions which don't need it.
2660  *
2661  * There are some functions which can sleep for arbitrary periods
2662  * (paste_selection) but we don't need the lock there anyway.
2663  *
2664  * set_selection has locking, and definitely needs it
2665  */
2666 
2667 int tioclinux(struct tty_struct *tty, unsigned long arg)
2668 {
2669 	char type, data;
2670 	char __user *p = (char __user *)arg;
2671 	int lines;
2672 	int ret;
2673 
2674 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
2675 		return -EPERM;
2676 	if (get_user(type, p))
2677 		return -EFAULT;
2678 	ret = 0;
2679 
2680 	switch (type)
2681 	{
2682 		case TIOCL_SETSEL:
2683 			console_lock();
2684 			ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
2685 			console_unlock();
2686 			break;
2687 		case TIOCL_PASTESEL:
2688 			ret = paste_selection(tty);
2689 			break;
2690 		case TIOCL_UNBLANKSCREEN:
2691 			console_lock();
2692 			unblank_screen();
2693 			console_unlock();
2694 			break;
2695 		case TIOCL_SELLOADLUT:
2696 			console_lock();
2697 			ret = sel_loadlut(p);
2698 			console_unlock();
2699 			break;
2700 		case TIOCL_GETSHIFTSTATE:
2701 
2702 	/*
2703 	 * Make it possible to react to Shift+Mousebutton.
2704 	 * Note that 'shift_state' is an undocumented
2705 	 * kernel-internal variable; programs not closely
2706 	 * related to the kernel should not use this.
2707 	 */
2708 			data = vt_get_shift_state();
2709 			ret = __put_user(data, p);
2710 			break;
2711 		case TIOCL_GETMOUSEREPORTING:
2712 			console_lock();	/* May be overkill */
2713 			data = mouse_reporting();
2714 			console_unlock();
2715 			ret = __put_user(data, p);
2716 			break;
2717 		case TIOCL_SETVESABLANK:
2718 			console_lock();
2719 			ret = set_vesa_blanking(p);
2720 			console_unlock();
2721 			break;
2722 		case TIOCL_GETKMSGREDIRECT:
2723 			data = vt_get_kmsg_redirect();
2724 			ret = __put_user(data, p);
2725 			break;
2726 		case TIOCL_SETKMSGREDIRECT:
2727 			if (!capable(CAP_SYS_ADMIN)) {
2728 				ret = -EPERM;
2729 			} else {
2730 				if (get_user(data, p+1))
2731 					ret = -EFAULT;
2732 				else
2733 					vt_kmsg_redirect(data);
2734 			}
2735 			break;
2736 		case TIOCL_GETFGCONSOLE:
2737 			/* No locking needed as this is a transiently
2738 			   correct return anyway if the caller hasn't
2739 			   disabled switching */
2740 			ret = fg_console;
2741 			break;
2742 		case TIOCL_SCROLLCONSOLE:
2743 			if (get_user(lines, (s32 __user *)(p+4))) {
2744 				ret = -EFAULT;
2745 			} else {
2746 				/* Need the console lock here. Note that lots
2747 				   of other calls need fixing before the lock
2748 				   is actually useful ! */
2749 				console_lock();
2750 				scrollfront(vc_cons[fg_console].d, lines);
2751 				console_unlock();
2752 				ret = 0;
2753 			}
2754 			break;
2755 		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
2756 			console_lock();
2757 			ignore_poke = 1;
2758 			do_blank_screen(0);
2759 			console_unlock();
2760 			break;
2761 		case TIOCL_BLANKEDSCREEN:
2762 			ret = console_blanked;
2763 			break;
2764 		default:
2765 			ret = -EINVAL;
2766 			break;
2767 	}
2768 	return ret;
2769 }
2770 
2771 /*
2772  * /dev/ttyN handling
2773  */
2774 
2775 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2776 {
2777 	int	retval;
2778 
2779 	retval = do_con_write(tty, buf, count);
2780 	con_flush_chars(tty);
2781 
2782 	return retval;
2783 }
2784 
2785 static int con_put_char(struct tty_struct *tty, unsigned char ch)
2786 {
2787 	if (in_interrupt())
2788 		return 0;	/* n_r3964 calls put_char() from interrupt context */
2789 	return do_con_write(tty, &ch, 1);
2790 }
2791 
2792 static int con_write_room(struct tty_struct *tty)
2793 {
2794 	if (tty->stopped)
2795 		return 0;
2796 	return 32768;		/* No limit, really; we're not buffering */
2797 }
2798 
2799 static int con_chars_in_buffer(struct tty_struct *tty)
2800 {
2801 	return 0;		/* we're not buffering */
2802 }
2803 
2804 /*
2805  * con_throttle and con_unthrottle are only used for
2806  * paste_selection(), which has to stuff in a large number of
2807  * characters...
2808  */
2809 static void con_throttle(struct tty_struct *tty)
2810 {
2811 }
2812 
2813 static void con_unthrottle(struct tty_struct *tty)
2814 {
2815 	struct vc_data *vc = tty->driver_data;
2816 
2817 	wake_up_interruptible(&vc->paste_wait);
2818 }
2819 
2820 /*
2821  * Turn the Scroll-Lock LED on when the tty is stopped
2822  */
2823 static void con_stop(struct tty_struct *tty)
2824 {
2825 	int console_num;
2826 	if (!tty)
2827 		return;
2828 	console_num = tty->index;
2829 	if (!vc_cons_allocated(console_num))
2830 		return;
2831 	vt_kbd_con_stop(console_num);
2832 }
2833 
2834 /*
2835  * Turn the Scroll-Lock LED off when the console is started
2836  */
2837 static void con_start(struct tty_struct *tty)
2838 {
2839 	int console_num;
2840 	if (!tty)
2841 		return;
2842 	console_num = tty->index;
2843 	if (!vc_cons_allocated(console_num))
2844 		return;
2845 	vt_kbd_con_start(console_num);
2846 }
2847 
2848 static void con_flush_chars(struct tty_struct *tty)
2849 {
2850 	struct vc_data *vc;
2851 
2852 	if (in_interrupt())	/* from flush_to_ldisc */
2853 		return;
2854 
2855 	/* if we race with con_close(), vt may be null */
2856 	console_lock();
2857 	vc = tty->driver_data;
2858 	if (vc)
2859 		set_cursor(vc);
2860 	console_unlock();
2861 }
2862 
2863 /*
2864  * Allocate the console screen memory.
2865  */
2866 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
2867 {
2868 	unsigned int currcons = tty->index;
2869 	struct vc_data *vc;
2870 	int ret;
2871 
2872 	console_lock();
2873 	ret = vc_allocate(currcons);
2874 	if (ret)
2875 		goto unlock;
2876 
2877 	vc = vc_cons[currcons].d;
2878 
2879 	/* Still being freed */
2880 	if (vc->port.tty) {
2881 		ret = -ERESTARTSYS;
2882 		goto unlock;
2883 	}
2884 
2885 	ret = tty_port_install(&vc->port, driver, tty);
2886 	if (ret)
2887 		goto unlock;
2888 
2889 	tty->driver_data = vc;
2890 	vc->port.tty = tty;
2891 
2892 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
2893 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
2894 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
2895 	}
2896 	if (vc->vc_utf)
2897 		tty->termios.c_iflag |= IUTF8;
2898 	else
2899 		tty->termios.c_iflag &= ~IUTF8;
2900 unlock:
2901 	console_unlock();
2902 	return ret;
2903 }
2904 
2905 static int con_open(struct tty_struct *tty, struct file *filp)
2906 {
2907 	/* everything done in install */
2908 	return 0;
2909 }
2910 
2911 
2912 static void con_close(struct tty_struct *tty, struct file *filp)
2913 {
2914 	/* Nothing to do - we defer to shutdown */
2915 }
2916 
2917 static void con_shutdown(struct tty_struct *tty)
2918 {
2919 	struct vc_data *vc = tty->driver_data;
2920 	BUG_ON(vc == NULL);
2921 	console_lock();
2922 	vc->port.tty = NULL;
2923 	console_unlock();
2924 }
2925 
2926 static int default_color           = 7; /* white */
2927 static int default_italic_color    = 2; // green (ASCII)
2928 static int default_underline_color = 3; // cyan (ASCII)
2929 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
2930 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
2931 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
2932 
2933 static void vc_init(struct vc_data *vc, unsigned int rows,
2934 		    unsigned int cols, int do_clear)
2935 {
2936 	int j, k ;
2937 
2938 	vc->vc_cols = cols;
2939 	vc->vc_rows = rows;
2940 	vc->vc_size_row = cols << 1;
2941 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
2942 
2943 	set_origin(vc);
2944 	vc->vc_pos = vc->vc_origin;
2945 	reset_vc(vc);
2946 	for (j=k=0; j<16; j++) {
2947 		vc->vc_palette[k++] = default_red[j] ;
2948 		vc->vc_palette[k++] = default_grn[j] ;
2949 		vc->vc_palette[k++] = default_blu[j] ;
2950 	}
2951 	vc->vc_def_color       = default_color;
2952 	vc->vc_ulcolor         = default_underline_color;
2953 	vc->vc_itcolor         = default_italic_color;
2954 	vc->vc_halfcolor       = 0x08;   /* grey */
2955 	init_waitqueue_head(&vc->paste_wait);
2956 	reset_terminal(vc, do_clear);
2957 }
2958 
2959 /*
2960  * This routine initializes console interrupts, and does nothing
2961  * else. If you want the screen to clear, call tty_write with
2962  * the appropriate escape-sequence.
2963  */
2964 
2965 static int __init con_init(void)
2966 {
2967 	const char *display_desc = NULL;
2968 	struct vc_data *vc;
2969 	unsigned int currcons = 0, i;
2970 
2971 	console_lock();
2972 
2973 	if (conswitchp)
2974 		display_desc = conswitchp->con_startup();
2975 	if (!display_desc) {
2976 		fg_console = 0;
2977 		console_unlock();
2978 		return 0;
2979 	}
2980 
2981 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
2982 		struct con_driver *con_driver = &registered_con_driver[i];
2983 
2984 		if (con_driver->con == NULL) {
2985 			con_driver->con = conswitchp;
2986 			con_driver->desc = display_desc;
2987 			con_driver->flag = CON_DRIVER_FLAG_INIT;
2988 			con_driver->first = 0;
2989 			con_driver->last = MAX_NR_CONSOLES - 1;
2990 			break;
2991 		}
2992 	}
2993 
2994 	for (i = 0; i < MAX_NR_CONSOLES; i++)
2995 		con_driver_map[i] = conswitchp;
2996 
2997 	if (blankinterval) {
2998 		blank_state = blank_normal_wait;
2999 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3000 	}
3001 
3002 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3003 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3004 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3005 		tty_port_init(&vc->port);
3006 		visual_init(vc, currcons, 1);
3007 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3008 		vc_init(vc, vc->vc_rows, vc->vc_cols,
3009 			currcons || !vc->vc_sw->con_save_screen);
3010 	}
3011 	currcons = fg_console = 0;
3012 	master_display_fg = vc = vc_cons[currcons].d;
3013 	set_origin(vc);
3014 	save_screen(vc);
3015 	gotoxy(vc, vc->vc_x, vc->vc_y);
3016 	csi_J(vc, 0);
3017 	update_screen(vc);
3018 	pr_info("Console: %s %s %dx%d\n",
3019 		vc->vc_can_do_color ? "colour" : "mono",
3020 		display_desc, vc->vc_cols, vc->vc_rows);
3021 	printable = 1;
3022 
3023 	console_unlock();
3024 
3025 #ifdef CONFIG_VT_CONSOLE
3026 	register_console(&vt_console_driver);
3027 #endif
3028 	return 0;
3029 }
3030 console_initcall(con_init);
3031 
3032 static const struct tty_operations con_ops = {
3033 	.install = con_install,
3034 	.open = con_open,
3035 	.close = con_close,
3036 	.write = con_write,
3037 	.write_room = con_write_room,
3038 	.put_char = con_put_char,
3039 	.flush_chars = con_flush_chars,
3040 	.chars_in_buffer = con_chars_in_buffer,
3041 	.ioctl = vt_ioctl,
3042 #ifdef CONFIG_COMPAT
3043 	.compat_ioctl = vt_compat_ioctl,
3044 #endif
3045 	.stop = con_stop,
3046 	.start = con_start,
3047 	.throttle = con_throttle,
3048 	.unthrottle = con_unthrottle,
3049 	.resize = vt_resize,
3050 	.shutdown = con_shutdown
3051 };
3052 
3053 static struct cdev vc0_cdev;
3054 
3055 static ssize_t show_tty_active(struct device *dev,
3056 				struct device_attribute *attr, char *buf)
3057 {
3058 	return sprintf(buf, "tty%d\n", fg_console + 1);
3059 }
3060 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3061 
3062 static struct attribute *vt_dev_attrs[] = {
3063 	&dev_attr_active.attr,
3064 	NULL
3065 };
3066 
3067 ATTRIBUTE_GROUPS(vt_dev);
3068 
3069 int __init vty_init(const struct file_operations *console_fops)
3070 {
3071 	cdev_init(&vc0_cdev, console_fops);
3072 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3073 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3074 		panic("Couldn't register /dev/tty0 driver\n");
3075 	tty0dev = device_create_with_groups(tty_class, NULL,
3076 					    MKDEV(TTY_MAJOR, 0), NULL,
3077 					    vt_dev_groups, "tty0");
3078 	if (IS_ERR(tty0dev))
3079 		tty0dev = NULL;
3080 
3081 	vcs_init();
3082 
3083 	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3084 	if (!console_driver)
3085 		panic("Couldn't allocate console driver\n");
3086 
3087 	console_driver->name = "tty";
3088 	console_driver->name_base = 1;
3089 	console_driver->major = TTY_MAJOR;
3090 	console_driver->minor_start = 1;
3091 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3092 	console_driver->init_termios = tty_std_termios;
3093 	if (default_utf8)
3094 		console_driver->init_termios.c_iflag |= IUTF8;
3095 	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3096 	tty_set_operations(console_driver, &con_ops);
3097 	if (tty_register_driver(console_driver))
3098 		panic("Couldn't register console driver\n");
3099 	kbd_init();
3100 	console_map_init();
3101 #ifdef CONFIG_MDA_CONSOLE
3102 	mda_console_init();
3103 #endif
3104 	return 0;
3105 }
3106 
3107 #ifndef VT_SINGLE_DRIVER
3108 
3109 static struct class *vtconsole_class;
3110 
3111 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3112 			   int deflt)
3113 {
3114 	struct module *owner = csw->owner;
3115 	const char *desc = NULL;
3116 	struct con_driver *con_driver;
3117 	int i, j = -1, k = -1, retval = -ENODEV;
3118 
3119 	if (!try_module_get(owner))
3120 		return -ENODEV;
3121 
3122 	WARN_CONSOLE_UNLOCKED();
3123 
3124 	/* check if driver is registered */
3125 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3126 		con_driver = &registered_con_driver[i];
3127 
3128 		if (con_driver->con == csw) {
3129 			desc = con_driver->desc;
3130 			retval = 0;
3131 			break;
3132 		}
3133 	}
3134 
3135 	if (retval)
3136 		goto err;
3137 
3138 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3139 		csw->con_startup();
3140 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3141 	}
3142 
3143 	if (deflt) {
3144 		if (conswitchp)
3145 			module_put(conswitchp->owner);
3146 
3147 		__module_get(owner);
3148 		conswitchp = csw;
3149 	}
3150 
3151 	first = max(first, con_driver->first);
3152 	last = min(last, con_driver->last);
3153 
3154 	for (i = first; i <= last; i++) {
3155 		int old_was_color;
3156 		struct vc_data *vc = vc_cons[i].d;
3157 
3158 		if (con_driver_map[i])
3159 			module_put(con_driver_map[i]->owner);
3160 		__module_get(owner);
3161 		con_driver_map[i] = csw;
3162 
3163 		if (!vc || !vc->vc_sw)
3164 			continue;
3165 
3166 		j = i;
3167 
3168 		if (con_is_visible(vc)) {
3169 			k = i;
3170 			save_screen(vc);
3171 		}
3172 
3173 		old_was_color = vc->vc_can_do_color;
3174 		vc->vc_sw->con_deinit(vc);
3175 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3176 		visual_init(vc, i, 0);
3177 		set_origin(vc);
3178 		update_attr(vc);
3179 
3180 		/* If the console changed between mono <-> color, then
3181 		 * the attributes in the screenbuf will be wrong.  The
3182 		 * following resets all attributes to something sane.
3183 		 */
3184 		if (old_was_color != vc->vc_can_do_color)
3185 			clear_buffer_attributes(vc);
3186 	}
3187 
3188 	pr_info("Console: switching ");
3189 	if (!deflt)
3190 		printk(KERN_CONT "consoles %d-%d ", first+1, last+1);
3191 	if (j >= 0) {
3192 		struct vc_data *vc = vc_cons[j].d;
3193 
3194 		printk(KERN_CONT "to %s %s %dx%d\n",
3195 		       vc->vc_can_do_color ? "colour" : "mono",
3196 		       desc, vc->vc_cols, vc->vc_rows);
3197 
3198 		if (k >= 0) {
3199 			vc = vc_cons[k].d;
3200 			update_screen(vc);
3201 		}
3202 	} else
3203 		printk(KERN_CONT "to %s\n", desc);
3204 
3205 	retval = 0;
3206 err:
3207 	module_put(owner);
3208 	return retval;
3209 };
3210 
3211 
3212 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3213 /* unlocked version of unbind_con_driver() */
3214 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3215 {
3216 	struct module *owner = csw->owner;
3217 	const struct consw *defcsw = NULL;
3218 	struct con_driver *con_driver = NULL, *con_back = NULL;
3219 	int i, retval = -ENODEV;
3220 
3221 	if (!try_module_get(owner))
3222 		return -ENODEV;
3223 
3224 	WARN_CONSOLE_UNLOCKED();
3225 
3226 	/* check if driver is registered and if it is unbindable */
3227 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3228 		con_driver = &registered_con_driver[i];
3229 
3230 		if (con_driver->con == csw &&
3231 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3232 			retval = 0;
3233 			break;
3234 		}
3235 	}
3236 
3237 	if (retval)
3238 		goto err;
3239 
3240 	retval = -ENODEV;
3241 
3242 	/* check if backup driver exists */
3243 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3244 		con_back = &registered_con_driver[i];
3245 
3246 		if (con_back->con && con_back->con != csw) {
3247 			defcsw = con_back->con;
3248 			retval = 0;
3249 			break;
3250 		}
3251 	}
3252 
3253 	if (retval)
3254 		goto err;
3255 
3256 	if (!con_is_bound(csw))
3257 		goto err;
3258 
3259 	first = max(first, con_driver->first);
3260 	last = min(last, con_driver->last);
3261 
3262 	for (i = first; i <= last; i++) {
3263 		if (con_driver_map[i] == csw) {
3264 			module_put(csw->owner);
3265 			con_driver_map[i] = NULL;
3266 		}
3267 	}
3268 
3269 	if (!con_is_bound(defcsw)) {
3270 		const struct consw *defconsw = conswitchp;
3271 
3272 		defcsw->con_startup();
3273 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3274 		/*
3275 		 * vgacon may change the default driver to point
3276 		 * to dummycon, we restore it here...
3277 		 */
3278 		conswitchp = defconsw;
3279 	}
3280 
3281 	if (!con_is_bound(csw))
3282 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3283 
3284 	/* ignore return value, binding should not fail */
3285 	do_bind_con_driver(defcsw, first, last, deflt);
3286 err:
3287 	module_put(owner);
3288 	return retval;
3289 
3290 }
3291 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3292 
3293 static int vt_bind(struct con_driver *con)
3294 {
3295 	const struct consw *defcsw = NULL, *csw = NULL;
3296 	int i, more = 1, first = -1, last = -1, deflt = 0;
3297 
3298  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3299 		goto err;
3300 
3301 	csw = con->con;
3302 
3303 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3304 		struct con_driver *con = &registered_con_driver[i];
3305 
3306 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3307 			defcsw = con->con;
3308 			break;
3309 		}
3310 	}
3311 
3312 	if (!defcsw)
3313 		goto err;
3314 
3315 	while (more) {
3316 		more = 0;
3317 
3318 		for (i = con->first; i <= con->last; i++) {
3319 			if (con_driver_map[i] == defcsw) {
3320 				if (first == -1)
3321 					first = i;
3322 				last = i;
3323 				more = 1;
3324 			} else if (first != -1)
3325 				break;
3326 		}
3327 
3328 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3329 			deflt = 1;
3330 
3331 		if (first != -1)
3332 			do_bind_con_driver(csw, first, last, deflt);
3333 
3334 		first = -1;
3335 		last = -1;
3336 		deflt = 0;
3337 	}
3338 
3339 err:
3340 	return 0;
3341 }
3342 
3343 static int vt_unbind(struct con_driver *con)
3344 {
3345 	const struct consw *csw = NULL;
3346 	int i, more = 1, first = -1, last = -1, deflt = 0;
3347 	int ret;
3348 
3349  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3350 		goto err;
3351 
3352 	csw = con->con;
3353 
3354 	while (more) {
3355 		more = 0;
3356 
3357 		for (i = con->first; i <= con->last; i++) {
3358 			if (con_driver_map[i] == csw) {
3359 				if (first == -1)
3360 					first = i;
3361 				last = i;
3362 				more = 1;
3363 			} else if (first != -1)
3364 				break;
3365 		}
3366 
3367 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3368 			deflt = 1;
3369 
3370 		if (first != -1) {
3371 			ret = do_unbind_con_driver(csw, first, last, deflt);
3372 			if (ret != 0)
3373 				return ret;
3374 		}
3375 
3376 		first = -1;
3377 		last = -1;
3378 		deflt = 0;
3379 	}
3380 
3381 err:
3382 	return 0;
3383 }
3384 #else
3385 static inline int vt_bind(struct con_driver *con)
3386 {
3387 	return 0;
3388 }
3389 static inline int vt_unbind(struct con_driver *con)
3390 {
3391 	return 0;
3392 }
3393 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3394 
3395 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3396 			  const char *buf, size_t count)
3397 {
3398 	struct con_driver *con = dev_get_drvdata(dev);
3399 	int bind = simple_strtoul(buf, NULL, 0);
3400 
3401 	console_lock();
3402 
3403 	if (bind)
3404 		vt_bind(con);
3405 	else
3406 		vt_unbind(con);
3407 
3408 	console_unlock();
3409 
3410 	return count;
3411 }
3412 
3413 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3414 			 char *buf)
3415 {
3416 	struct con_driver *con = dev_get_drvdata(dev);
3417 	int bind = con_is_bound(con->con);
3418 
3419 	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3420 }
3421 
3422 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3423 			 char *buf)
3424 {
3425 	struct con_driver *con = dev_get_drvdata(dev);
3426 
3427 	return snprintf(buf, PAGE_SIZE, "%s %s\n",
3428 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3429 			 con->desc);
3430 
3431 }
3432 
3433 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3434 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3435 
3436 static struct attribute *con_dev_attrs[] = {
3437 	&dev_attr_bind.attr,
3438 	&dev_attr_name.attr,
3439 	NULL
3440 };
3441 
3442 ATTRIBUTE_GROUPS(con_dev);
3443 
3444 static int vtconsole_init_device(struct con_driver *con)
3445 {
3446 	con->flag |= CON_DRIVER_FLAG_ATTR;
3447 	return 0;
3448 }
3449 
3450 static void vtconsole_deinit_device(struct con_driver *con)
3451 {
3452 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3453 }
3454 
3455 /**
3456  * con_is_bound - checks if driver is bound to the console
3457  * @csw: console driver
3458  *
3459  * RETURNS: zero if unbound, nonzero if bound
3460  *
3461  * Drivers can call this and if zero, they should release
3462  * all resources allocated on con_startup()
3463  */
3464 int con_is_bound(const struct consw *csw)
3465 {
3466 	int i, bound = 0;
3467 
3468 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3469 		if (con_driver_map[i] == csw) {
3470 			bound = 1;
3471 			break;
3472 		}
3473 	}
3474 
3475 	return bound;
3476 }
3477 EXPORT_SYMBOL(con_is_bound);
3478 
3479 /**
3480  * con_debug_enter - prepare the console for the kernel debugger
3481  * @sw: console driver
3482  *
3483  * Called when the console is taken over by the kernel debugger, this
3484  * function needs to save the current console state, then put the console
3485  * into a state suitable for the kernel debugger.
3486  *
3487  * RETURNS:
3488  * Zero on success, nonzero if a failure occurred when trying to prepare
3489  * the console for the debugger.
3490  */
3491 int con_debug_enter(struct vc_data *vc)
3492 {
3493 	int ret = 0;
3494 
3495 	saved_fg_console = fg_console;
3496 	saved_last_console = last_console;
3497 	saved_want_console = want_console;
3498 	saved_vc_mode = vc->vc_mode;
3499 	saved_console_blanked = console_blanked;
3500 	vc->vc_mode = KD_TEXT;
3501 	console_blanked = 0;
3502 	if (vc->vc_sw->con_debug_enter)
3503 		ret = vc->vc_sw->con_debug_enter(vc);
3504 #ifdef CONFIG_KGDB_KDB
3505 	/* Set the initial LINES variable if it is not already set */
3506 	if (vc->vc_rows < 999) {
3507 		int linecount;
3508 		char lns[4];
3509 		const char *setargs[3] = {
3510 			"set",
3511 			"LINES",
3512 			lns,
3513 		};
3514 		if (kdbgetintenv(setargs[0], &linecount)) {
3515 			snprintf(lns, 4, "%i", vc->vc_rows);
3516 			kdb_set(2, setargs);
3517 		}
3518 	}
3519 	if (vc->vc_cols < 999) {
3520 		int colcount;
3521 		char cols[4];
3522 		const char *setargs[3] = {
3523 			"set",
3524 			"COLUMNS",
3525 			cols,
3526 		};
3527 		if (kdbgetintenv(setargs[0], &colcount)) {
3528 			snprintf(cols, 4, "%i", vc->vc_cols);
3529 			kdb_set(2, setargs);
3530 		}
3531 	}
3532 #endif /* CONFIG_KGDB_KDB */
3533 	return ret;
3534 }
3535 EXPORT_SYMBOL_GPL(con_debug_enter);
3536 
3537 /**
3538  * con_debug_leave - restore console state
3539  * @sw: console driver
3540  *
3541  * Restore the console state to what it was before the kernel debugger
3542  * was invoked.
3543  *
3544  * RETURNS:
3545  * Zero on success, nonzero if a failure occurred when trying to restore
3546  * the console.
3547  */
3548 int con_debug_leave(void)
3549 {
3550 	struct vc_data *vc;
3551 	int ret = 0;
3552 
3553 	fg_console = saved_fg_console;
3554 	last_console = saved_last_console;
3555 	want_console = saved_want_console;
3556 	console_blanked = saved_console_blanked;
3557 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3558 
3559 	vc = vc_cons[fg_console].d;
3560 	if (vc->vc_sw->con_debug_leave)
3561 		ret = vc->vc_sw->con_debug_leave(vc);
3562 	return ret;
3563 }
3564 EXPORT_SYMBOL_GPL(con_debug_leave);
3565 
3566 static int do_register_con_driver(const struct consw *csw, int first, int last)
3567 {
3568 	struct module *owner = csw->owner;
3569 	struct con_driver *con_driver;
3570 	const char *desc;
3571 	int i, retval;
3572 
3573 	WARN_CONSOLE_UNLOCKED();
3574 
3575 	if (!try_module_get(owner))
3576 		return -ENODEV;
3577 
3578 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3579 		con_driver = &registered_con_driver[i];
3580 
3581 		/* already registered */
3582 		if (con_driver->con == csw) {
3583 			retval = -EBUSY;
3584 			goto err;
3585 		}
3586 	}
3587 
3588 	desc = csw->con_startup();
3589 	if (!desc) {
3590 		retval = -ENODEV;
3591 		goto err;
3592 	}
3593 
3594 	retval = -EINVAL;
3595 
3596 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3597 		con_driver = &registered_con_driver[i];
3598 
3599 		if (con_driver->con == NULL &&
3600 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3601 			con_driver->con = csw;
3602 			con_driver->desc = desc;
3603 			con_driver->node = i;
3604 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
3605 			                   CON_DRIVER_FLAG_INIT;
3606 			con_driver->first = first;
3607 			con_driver->last = last;
3608 			retval = 0;
3609 			break;
3610 		}
3611 	}
3612 
3613 	if (retval)
3614 		goto err;
3615 
3616 	con_driver->dev =
3617 		device_create_with_groups(vtconsole_class, NULL,
3618 					  MKDEV(0, con_driver->node),
3619 					  con_driver, con_dev_groups,
3620 					  "vtcon%i", con_driver->node);
3621 	if (IS_ERR(con_driver->dev)) {
3622 		printk(KERN_WARNING "Unable to create device for %s; "
3623 		       "errno = %ld\n", con_driver->desc,
3624 		       PTR_ERR(con_driver->dev));
3625 		con_driver->dev = NULL;
3626 	} else {
3627 		vtconsole_init_device(con_driver);
3628 	}
3629 
3630 err:
3631 	module_put(owner);
3632 	return retval;
3633 }
3634 
3635 
3636 /**
3637  * do_unregister_con_driver - unregister console driver from console layer
3638  * @csw: console driver
3639  *
3640  * DESCRIPTION: All drivers that registers to the console layer must
3641  * call this function upon exit, or if the console driver is in a state
3642  * where it won't be able to handle console services, such as the
3643  * framebuffer console without loaded framebuffer drivers.
3644  *
3645  * The driver must unbind first prior to unregistration.
3646  */
3647 int do_unregister_con_driver(const struct consw *csw)
3648 {
3649 	int i;
3650 
3651 	/* cannot unregister a bound driver */
3652 	if (con_is_bound(csw))
3653 		return -EBUSY;
3654 
3655 	if (csw == conswitchp)
3656 		return -EINVAL;
3657 
3658 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3659 		struct con_driver *con_driver = &registered_con_driver[i];
3660 
3661 		if (con_driver->con == csw) {
3662 			/*
3663 			 * Defer the removal of the sysfs entries since that
3664 			 * will acquire the kernfs s_active lock and we can't
3665 			 * acquire this lock while holding the console lock:
3666 			 * the unbind sysfs entry imposes already the opposite
3667 			 * order. Reset con already here to prevent any later
3668 			 * lookup to succeed and mark this slot as zombie, so
3669 			 * it won't get reused until we complete the removal
3670 			 * in the deferred work.
3671 			 */
3672 			con_driver->con = NULL;
3673 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
3674 			schedule_work(&con_driver_unregister_work);
3675 
3676 			return 0;
3677 		}
3678 	}
3679 
3680 	return -ENODEV;
3681 }
3682 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
3683 
3684 static void con_driver_unregister_callback(struct work_struct *ignored)
3685 {
3686 	int i;
3687 
3688 	console_lock();
3689 
3690 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3691 		struct con_driver *con_driver = &registered_con_driver[i];
3692 
3693 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
3694 			continue;
3695 
3696 		console_unlock();
3697 
3698 		vtconsole_deinit_device(con_driver);
3699 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
3700 
3701 		console_lock();
3702 
3703 		if (WARN_ON_ONCE(con_driver->con))
3704 			con_driver->con = NULL;
3705 		con_driver->desc = NULL;
3706 		con_driver->dev = NULL;
3707 		con_driver->node = 0;
3708 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
3709 		con_driver->flag = 0;
3710 		con_driver->first = 0;
3711 		con_driver->last = 0;
3712 	}
3713 
3714 	console_unlock();
3715 }
3716 
3717 /*
3718  *	If we support more console drivers, this function is used
3719  *	when a driver wants to take over some existing consoles
3720  *	and become default driver for newly opened ones.
3721  *
3722  *	do_take_over_console is basically a register followed by unbind
3723  */
3724 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
3725 {
3726 	int err;
3727 
3728 	err = do_register_con_driver(csw, first, last);
3729 	/*
3730 	 * If we get an busy error we still want to bind the console driver
3731 	 * and return success, as we may have unbound the console driver
3732 	 * but not unregistered it.
3733 	 */
3734 	if (err == -EBUSY)
3735 		err = 0;
3736 	if (!err)
3737 		do_bind_con_driver(csw, first, last, deflt);
3738 
3739 	return err;
3740 }
3741 EXPORT_SYMBOL_GPL(do_take_over_console);
3742 
3743 
3744 /*
3745  * give_up_console is a wrapper to unregister_con_driver. It will only
3746  * work if driver is fully unbound.
3747  */
3748 void give_up_console(const struct consw *csw)
3749 {
3750 	console_lock();
3751 	do_unregister_con_driver(csw);
3752 	console_unlock();
3753 }
3754 
3755 static int __init vtconsole_class_init(void)
3756 {
3757 	int i;
3758 
3759 	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
3760 	if (IS_ERR(vtconsole_class)) {
3761 		printk(KERN_WARNING "Unable to create vt console class; "
3762 		       "errno = %ld\n", PTR_ERR(vtconsole_class));
3763 		vtconsole_class = NULL;
3764 	}
3765 
3766 	/* Add system drivers to sysfs */
3767 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3768 		struct con_driver *con = &registered_con_driver[i];
3769 
3770 		if (con->con && !con->dev) {
3771 			con->dev =
3772 				device_create_with_groups(vtconsole_class, NULL,
3773 							  MKDEV(0, con->node),
3774 							  con, con_dev_groups,
3775 							  "vtcon%i", con->node);
3776 
3777 			if (IS_ERR(con->dev)) {
3778 				printk(KERN_WARNING "Unable to create "
3779 				       "device for %s; errno = %ld\n",
3780 				       con->desc, PTR_ERR(con->dev));
3781 				con->dev = NULL;
3782 			} else {
3783 				vtconsole_init_device(con);
3784 			}
3785 		}
3786 	}
3787 
3788 	return 0;
3789 }
3790 postcore_initcall(vtconsole_class_init);
3791 
3792 #endif
3793 
3794 /*
3795  *	Screen blanking
3796  */
3797 
3798 static int set_vesa_blanking(char __user *p)
3799 {
3800 	unsigned int mode;
3801 
3802 	if (get_user(mode, p + 1))
3803 		return -EFAULT;
3804 
3805 	vesa_blank_mode = (mode < 4) ? mode : 0;
3806 	return 0;
3807 }
3808 
3809 void do_blank_screen(int entering_gfx)
3810 {
3811 	struct vc_data *vc = vc_cons[fg_console].d;
3812 	int i;
3813 
3814 	WARN_CONSOLE_UNLOCKED();
3815 
3816 	if (console_blanked) {
3817 		if (blank_state == blank_vesa_wait) {
3818 			blank_state = blank_off;
3819 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
3820 		}
3821 		return;
3822 	}
3823 
3824 	/* entering graphics mode? */
3825 	if (entering_gfx) {
3826 		hide_cursor(vc);
3827 		save_screen(vc);
3828 		vc->vc_sw->con_blank(vc, -1, 1);
3829 		console_blanked = fg_console + 1;
3830 		blank_state = blank_off;
3831 		set_origin(vc);
3832 		return;
3833 	}
3834 
3835 	if (blank_state != blank_normal_wait)
3836 		return;
3837 	blank_state = blank_off;
3838 
3839 	/* don't blank graphics */
3840 	if (vc->vc_mode != KD_TEXT) {
3841 		console_blanked = fg_console + 1;
3842 		return;
3843 	}
3844 
3845 	hide_cursor(vc);
3846 	del_timer_sync(&console_timer);
3847 	blank_timer_expired = 0;
3848 
3849 	save_screen(vc);
3850 	/* In case we need to reset origin, blanking hook returns 1 */
3851 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
3852 	console_blanked = fg_console + 1;
3853 	if (i)
3854 		set_origin(vc);
3855 
3856 	if (console_blank_hook && console_blank_hook(1))
3857 		return;
3858 
3859 	if (vesa_off_interval && vesa_blank_mode) {
3860 		blank_state = blank_vesa_wait;
3861 		mod_timer(&console_timer, jiffies + vesa_off_interval);
3862 	}
3863 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
3864 }
3865 EXPORT_SYMBOL(do_blank_screen);
3866 
3867 /*
3868  * Called by timer as well as from vt_console_driver
3869  */
3870 void do_unblank_screen(int leaving_gfx)
3871 {
3872 	struct vc_data *vc;
3873 
3874 	/* This should now always be called from a "sane" (read: can schedule)
3875 	 * context for the sake of the low level drivers, except in the special
3876 	 * case of oops_in_progress
3877 	 */
3878 	if (!oops_in_progress)
3879 		might_sleep();
3880 
3881 	WARN_CONSOLE_UNLOCKED();
3882 
3883 	ignore_poke = 0;
3884 	if (!console_blanked)
3885 		return;
3886 	if (!vc_cons_allocated(fg_console)) {
3887 		/* impossible */
3888 		pr_warn("unblank_screen: tty %d not allocated ??\n",
3889 			fg_console + 1);
3890 		return;
3891 	}
3892 	vc = vc_cons[fg_console].d;
3893 	/* Try to unblank in oops case too */
3894 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
3895 		return; /* but leave console_blanked != 0 */
3896 
3897 	if (blankinterval) {
3898 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3899 		blank_state = blank_normal_wait;
3900 	}
3901 
3902 	console_blanked = 0;
3903 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
3904 		/* Low-level driver cannot restore -> do it ourselves */
3905 		update_screen(vc);
3906 	if (console_blank_hook)
3907 		console_blank_hook(0);
3908 	set_palette(vc);
3909 	set_cursor(vc);
3910 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
3911 }
3912 EXPORT_SYMBOL(do_unblank_screen);
3913 
3914 /*
3915  * This is called by the outside world to cause a forced unblank, mostly for
3916  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
3917  * call it with 1 as an argument and so force a mode restore... that may kill
3918  * X or at least garbage the screen but would also make the Oops visible...
3919  */
3920 void unblank_screen(void)
3921 {
3922 	do_unblank_screen(0);
3923 }
3924 
3925 /*
3926  * We defer the timer blanking to work queue so it can take the console mutex
3927  * (console operations can still happen at irq time, but only from printk which
3928  * has the console mutex. Not perfect yet, but better than no locking
3929  */
3930 static void blank_screen_t(unsigned long dummy)
3931 {
3932 	if (unlikely(!keventd_up())) {
3933 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3934 		return;
3935 	}
3936 	blank_timer_expired = 1;
3937 	schedule_work(&console_work);
3938 }
3939 
3940 void poke_blanked_console(void)
3941 {
3942 	WARN_CONSOLE_UNLOCKED();
3943 
3944 	/* Add this so we quickly catch whoever might call us in a non
3945 	 * safe context. Nowadays, unblank_screen() isn't to be called in
3946 	 * atomic contexts and is allowed to schedule (with the special case
3947 	 * of oops_in_progress, but that isn't of any concern for this
3948 	 * function. --BenH.
3949 	 */
3950 	might_sleep();
3951 
3952 	/* This isn't perfectly race free, but a race here would be mostly harmless,
3953 	 * at worse, we'll do a spurrious blank and it's unlikely
3954 	 */
3955 	del_timer(&console_timer);
3956 	blank_timer_expired = 0;
3957 
3958 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
3959 		return;
3960 	if (console_blanked)
3961 		unblank_screen();
3962 	else if (blankinterval) {
3963 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3964 		blank_state = blank_normal_wait;
3965 	}
3966 }
3967 
3968 /*
3969  *	Palettes
3970  */
3971 
3972 static void set_palette(struct vc_data *vc)
3973 {
3974 	WARN_CONSOLE_UNLOCKED();
3975 
3976 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
3977 		vc->vc_sw->con_set_palette(vc, color_table);
3978 }
3979 
3980 /*
3981  * Load palette into the DAC registers. arg points to a colour
3982  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
3983  */
3984 
3985 int con_set_cmap(unsigned char __user *arg)
3986 {
3987 	int i, j, k;
3988 	unsigned char colormap[3*16];
3989 
3990 	if (copy_from_user(colormap, arg, sizeof(colormap)))
3991 		return -EFAULT;
3992 
3993 	console_lock();
3994 	for (i = k = 0; i < 16; i++) {
3995 		default_red[i] = colormap[k++];
3996 		default_grn[i] = colormap[k++];
3997 		default_blu[i] = colormap[k++];
3998 	}
3999 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
4000 		if (!vc_cons_allocated(i))
4001 			continue;
4002 		for (j = k = 0; j < 16; j++) {
4003 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4004 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4005 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4006 		}
4007 		set_palette(vc_cons[i].d);
4008 	}
4009 	console_unlock();
4010 
4011 	return 0;
4012 }
4013 
4014 int con_get_cmap(unsigned char __user *arg)
4015 {
4016 	int i, k;
4017 	unsigned char colormap[3*16];
4018 
4019 	console_lock();
4020 	for (i = k = 0; i < 16; i++) {
4021 		colormap[k++] = default_red[i];
4022 		colormap[k++] = default_grn[i];
4023 		colormap[k++] = default_blu[i];
4024 	}
4025 	console_unlock();
4026 
4027 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4028 		return -EFAULT;
4029 
4030 	return 0;
4031 }
4032 
4033 void reset_palette(struct vc_data *vc)
4034 {
4035 	int j, k;
4036 	for (j=k=0; j<16; j++) {
4037 		vc->vc_palette[k++] = default_red[j];
4038 		vc->vc_palette[k++] = default_grn[j];
4039 		vc->vc_palette[k++] = default_blu[j];
4040 	}
4041 	set_palette(vc);
4042 }
4043 
4044 /*
4045  *  Font switching
4046  *
4047  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4048  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4049  *  depending on width) reserved for each character which is kinda wasty, but
4050  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4051  *  is up to the actual low-level console-driver convert data into its favorite
4052  *  format (maybe we should add a `fontoffset' field to the `display'
4053  *  structure so we won't have to convert the fontdata all the time.
4054  *  /Jes
4055  */
4056 
4057 #define max_font_size 65536
4058 
4059 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4060 {
4061 	struct console_font font;
4062 	int rc = -EINVAL;
4063 	int c;
4064 
4065 	if (op->data) {
4066 		font.data = kmalloc(max_font_size, GFP_KERNEL);
4067 		if (!font.data)
4068 			return -ENOMEM;
4069 	} else
4070 		font.data = NULL;
4071 
4072 	console_lock();
4073 	if (vc->vc_mode != KD_TEXT)
4074 		rc = -EINVAL;
4075 	else if (vc->vc_sw->con_font_get)
4076 		rc = vc->vc_sw->con_font_get(vc, &font);
4077 	else
4078 		rc = -ENOSYS;
4079 	console_unlock();
4080 
4081 	if (rc)
4082 		goto out;
4083 
4084 	c = (font.width+7)/8 * 32 * font.charcount;
4085 
4086 	if (op->data && font.charcount > op->charcount)
4087 		rc = -ENOSPC;
4088 	if (!(op->flags & KD_FONT_FLAG_OLD)) {
4089 		if (font.width > op->width || font.height > op->height)
4090 			rc = -ENOSPC;
4091 	} else {
4092 		if (font.width != 8)
4093 			rc = -EIO;
4094 		else if ((op->height && font.height > op->height) ||
4095 			 font.height > 32)
4096 			rc = -ENOSPC;
4097 	}
4098 	if (rc)
4099 		goto out;
4100 
4101 	op->height = font.height;
4102 	op->width = font.width;
4103 	op->charcount = font.charcount;
4104 
4105 	if (op->data && copy_to_user(op->data, font.data, c))
4106 		rc = -EFAULT;
4107 
4108 out:
4109 	kfree(font.data);
4110 	return rc;
4111 }
4112 
4113 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4114 {
4115 	struct console_font font;
4116 	int rc = -EINVAL;
4117 	int size;
4118 
4119 	if (vc->vc_mode != KD_TEXT)
4120 		return -EINVAL;
4121 	if (!op->data)
4122 		return -EINVAL;
4123 	if (op->charcount > 512)
4124 		return -EINVAL;
4125 	if (!op->height) {		/* Need to guess font height [compat] */
4126 		int h, i;
4127 		u8 __user *charmap = op->data;
4128 		u8 tmp;
4129 
4130 		/* If from KDFONTOP ioctl, don't allow things which can be done in userland,
4131 		   so that we can get rid of this soon */
4132 		if (!(op->flags & KD_FONT_FLAG_OLD))
4133 			return -EINVAL;
4134 		for (h = 32; h > 0; h--)
4135 			for (i = 0; i < op->charcount; i++) {
4136 				if (get_user(tmp, &charmap[32*i+h-1]))
4137 					return -EFAULT;
4138 				if (tmp)
4139 					goto nonzero;
4140 			}
4141 		return -EINVAL;
4142 	nonzero:
4143 		op->height = h;
4144 	}
4145 	if (op->width <= 0 || op->width > 32 || op->height > 32)
4146 		return -EINVAL;
4147 	size = (op->width+7)/8 * 32 * op->charcount;
4148 	if (size > max_font_size)
4149 		return -ENOSPC;
4150 	font.charcount = op->charcount;
4151 	font.height = op->height;
4152 	font.width = op->width;
4153 	font.data = memdup_user(op->data, size);
4154 	if (IS_ERR(font.data))
4155 		return PTR_ERR(font.data);
4156 	console_lock();
4157 	if (vc->vc_mode != KD_TEXT)
4158 		rc = -EINVAL;
4159 	else if (vc->vc_sw->con_font_set)
4160 		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4161 	else
4162 		rc = -ENOSYS;
4163 	console_unlock();
4164 	kfree(font.data);
4165 	return rc;
4166 }
4167 
4168 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4169 {
4170 	struct console_font font = {.width = op->width, .height = op->height};
4171 	char name[MAX_FONT_NAME];
4172 	char *s = name;
4173 	int rc;
4174 
4175 
4176 	if (!op->data)
4177 		s = NULL;
4178 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4179 		return -EFAULT;
4180 	else
4181 		name[MAX_FONT_NAME - 1] = 0;
4182 
4183 	console_lock();
4184 	if (vc->vc_mode != KD_TEXT) {
4185 		console_unlock();
4186 		return -EINVAL;
4187 	}
4188 	if (vc->vc_sw->con_font_default)
4189 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4190 	else
4191 		rc = -ENOSYS;
4192 	console_unlock();
4193 	if (!rc) {
4194 		op->width = font.width;
4195 		op->height = font.height;
4196 	}
4197 	return rc;
4198 }
4199 
4200 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4201 {
4202 	int con = op->height;
4203 	int rc;
4204 
4205 
4206 	console_lock();
4207 	if (vc->vc_mode != KD_TEXT)
4208 		rc = -EINVAL;
4209 	else if (!vc->vc_sw->con_font_copy)
4210 		rc = -ENOSYS;
4211 	else if (con < 0 || !vc_cons_allocated(con))
4212 		rc = -ENOTTY;
4213 	else if (con == vc->vc_num)	/* nothing to do */
4214 		rc = 0;
4215 	else
4216 		rc = vc->vc_sw->con_font_copy(vc, con);
4217 	console_unlock();
4218 	return rc;
4219 }
4220 
4221 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4222 {
4223 	switch (op->op) {
4224 	case KD_FONT_OP_SET:
4225 		return con_font_set(vc, op);
4226 	case KD_FONT_OP_GET:
4227 		return con_font_get(vc, op);
4228 	case KD_FONT_OP_SET_DEFAULT:
4229 		return con_font_default(vc, op);
4230 	case KD_FONT_OP_COPY:
4231 		return con_font_copy(vc, op);
4232 	}
4233 	return -ENOSYS;
4234 }
4235 
4236 /*
4237  *	Interface exported to selection and vcs.
4238  */
4239 
4240 /* used by selection */
4241 u16 screen_glyph(struct vc_data *vc, int offset)
4242 {
4243 	u16 w = scr_readw(screenpos(vc, offset, 1));
4244 	u16 c = w & 0xff;
4245 
4246 	if (w & vc->vc_hi_font_mask)
4247 		c |= 0x100;
4248 	return c;
4249 }
4250 EXPORT_SYMBOL_GPL(screen_glyph);
4251 
4252 /* used by vcs - note the word offset */
4253 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4254 {
4255 	return screenpos(vc, 2 * w_offset, viewed);
4256 }
4257 EXPORT_SYMBOL_GPL(screen_pos);
4258 
4259 void getconsxy(struct vc_data *vc, unsigned char *p)
4260 {
4261 	p[0] = vc->vc_x;
4262 	p[1] = vc->vc_y;
4263 }
4264 
4265 void putconsxy(struct vc_data *vc, unsigned char *p)
4266 {
4267 	hide_cursor(vc);
4268 	gotoxy(vc, p[0], p[1]);
4269 	set_cursor(vc);
4270 }
4271 
4272 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4273 {
4274 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4275 		return softcursor_original;
4276 	return scr_readw(org);
4277 }
4278 
4279 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4280 {
4281 	scr_writew(val, org);
4282 	if ((unsigned long)org == vc->vc_pos) {
4283 		softcursor_original = -1;
4284 		add_softcursor(vc);
4285 	}
4286 }
4287 
4288 void vcs_scr_updated(struct vc_data *vc)
4289 {
4290 	notify_update(vc);
4291 }
4292 
4293 /*
4294  *	Visible symbols for modules
4295  */
4296 
4297 EXPORT_SYMBOL(color_table);
4298 EXPORT_SYMBOL(default_red);
4299 EXPORT_SYMBOL(default_grn);
4300 EXPORT_SYMBOL(default_blu);
4301 EXPORT_SYMBOL(update_region);
4302 EXPORT_SYMBOL(redraw_screen);
4303 EXPORT_SYMBOL(vc_resize);
4304 EXPORT_SYMBOL(fg_console);
4305 EXPORT_SYMBOL(console_blank_hook);
4306 EXPORT_SYMBOL(console_blanked);
4307 EXPORT_SYMBOL(vc_cons);
4308 EXPORT_SYMBOL(global_cursor_default);
4309 #ifndef VT_SINGLE_DRIVER
4310 EXPORT_SYMBOL(give_up_console);
4311 #endif
4312