xref: /openbmc/linux/drivers/tty/vt/vt.c (revision bc5aa3a0)
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 < vc->vc_npar) {
1316 		/* 256 colours -- ubiquitous */
1317 		i++;
1318 		rgb_from_256(vc->vc_par[i], &c);
1319 	} else if (vc->vc_par[i] == 2 && i <= vc->vc_npar + 3) {
1320 		/* 24 bit -- extremely rare */
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] >= 30 && vc->vc_par[i] <= 37)
1419 				vc->vc_color = color_table[vc->vc_par[i] - 30]
1420 					| (vc->vc_color & 0xf0);
1421 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1422 				vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1423 					| (vc->vc_color & 0x0f);
1424 			break;
1425 		}
1426 	update_attr(vc);
1427 }
1428 
1429 static void respond_string(const char *p, struct tty_port *port)
1430 {
1431 	while (*p) {
1432 		tty_insert_flip_char(port, *p, 0);
1433 		p++;
1434 	}
1435 	tty_schedule_flip(port);
1436 }
1437 
1438 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1439 {
1440 	char buf[40];
1441 
1442 	sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1443 	respond_string(buf, tty->port);
1444 }
1445 
1446 static inline void status_report(struct tty_struct *tty)
1447 {
1448 	respond_string("\033[0n", tty->port);	/* Terminal ok */
1449 }
1450 
1451 static inline void respond_ID(struct tty_struct *tty)
1452 {
1453 	respond_string(VT102ID, tty->port);
1454 }
1455 
1456 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1457 {
1458 	char buf[8];
1459 
1460 	sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1461 		(char)('!' + mry));
1462 	respond_string(buf, tty->port);
1463 }
1464 
1465 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1466 int mouse_reporting(void)
1467 {
1468 	return vc_cons[fg_console].d->vc_report_mouse;
1469 }
1470 
1471 /* console_lock is held */
1472 static void set_mode(struct vc_data *vc, int on_off)
1473 {
1474 	int i;
1475 
1476 	for (i = 0; i <= vc->vc_npar; i++)
1477 		if (vc->vc_ques) {
1478 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1479 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1480 				if (on_off)
1481 					set_kbd(vc, decckm);
1482 				else
1483 					clr_kbd(vc, decckm);
1484 				break;
1485 			case 3:	/* 80/132 mode switch unimplemented */
1486 #if 0
1487 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1488 				/* this alone does not suffice; some user mode
1489 				   utility has to change the hardware regs */
1490 #endif
1491 				break;
1492 			case 5:			/* Inverted screen on/off */
1493 				if (vc->vc_decscnm != on_off) {
1494 					vc->vc_decscnm = on_off;
1495 					invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1496 					update_attr(vc);
1497 				}
1498 				break;
1499 			case 6:			/* Origin relative/absolute */
1500 				vc->vc_decom = on_off;
1501 				gotoxay(vc, 0, 0);
1502 				break;
1503 			case 7:			/* Autowrap on/off */
1504 				vc->vc_decawm = on_off;
1505 				break;
1506 			case 8:			/* Autorepeat on/off */
1507 				if (on_off)
1508 					set_kbd(vc, decarm);
1509 				else
1510 					clr_kbd(vc, decarm);
1511 				break;
1512 			case 9:
1513 				vc->vc_report_mouse = on_off ? 1 : 0;
1514 				break;
1515 			case 25:		/* Cursor on/off */
1516 				vc->vc_deccm = on_off;
1517 				break;
1518 			case 1000:
1519 				vc->vc_report_mouse = on_off ? 2 : 0;
1520 				break;
1521 			}
1522 		} else {
1523 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1524 			case 3:			/* Monitor (display ctrls) */
1525 				vc->vc_disp_ctrl = on_off;
1526 				break;
1527 			case 4:			/* Insert Mode on/off */
1528 				vc->vc_decim = on_off;
1529 				break;
1530 			case 20:		/* Lf, Enter == CrLf/Lf */
1531 				if (on_off)
1532 					set_kbd(vc, lnm);
1533 				else
1534 					clr_kbd(vc, lnm);
1535 				break;
1536 			}
1537 		}
1538 }
1539 
1540 /* console_lock is held */
1541 static void setterm_command(struct vc_data *vc)
1542 {
1543 	switch(vc->vc_par[0]) {
1544 		case 1:	/* set color for underline mode */
1545 			if (vc->vc_can_do_color &&
1546 					vc->vc_par[1] < 16) {
1547 				vc->vc_ulcolor = color_table[vc->vc_par[1]];
1548 				if (vc->vc_underline)
1549 					update_attr(vc);
1550 			}
1551 			break;
1552 		case 2:	/* set color for half intensity mode */
1553 			if (vc->vc_can_do_color &&
1554 					vc->vc_par[1] < 16) {
1555 				vc->vc_halfcolor = color_table[vc->vc_par[1]];
1556 				if (vc->vc_intensity == 0)
1557 					update_attr(vc);
1558 			}
1559 			break;
1560 		case 8:	/* store colors as defaults */
1561 			vc->vc_def_color = vc->vc_attr;
1562 			if (vc->vc_hi_font_mask == 0x100)
1563 				vc->vc_def_color >>= 1;
1564 			default_attr(vc);
1565 			update_attr(vc);
1566 			break;
1567 		case 9:	/* set blanking interval */
1568 			blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1569 			poke_blanked_console();
1570 			break;
1571 		case 10: /* set bell frequency in Hz */
1572 			if (vc->vc_npar >= 1)
1573 				vc->vc_bell_pitch = vc->vc_par[1];
1574 			else
1575 				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1576 			break;
1577 		case 11: /* set bell duration in msec */
1578 			if (vc->vc_npar >= 1)
1579 				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1580 					msecs_to_jiffies(vc->vc_par[1]) : 0;
1581 			else
1582 				vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1583 			break;
1584 		case 12: /* bring specified console to the front */
1585 			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1586 				set_console(vc->vc_par[1] - 1);
1587 			break;
1588 		case 13: /* unblank the screen */
1589 			poke_blanked_console();
1590 			break;
1591 		case 14: /* set vesa powerdown interval */
1592 			vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1593 			break;
1594 		case 15: /* activate the previous console */
1595 			set_console(last_console);
1596 			break;
1597 		case 16: /* set cursor blink duration in msec */
1598 			if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1599 					vc->vc_par[1] <= USHRT_MAX)
1600 				vc->vc_cur_blink_ms = vc->vc_par[1];
1601 			else
1602 				vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1603 			break;
1604 	}
1605 }
1606 
1607 /* console_lock is held */
1608 static void csi_at(struct vc_data *vc, unsigned int nr)
1609 {
1610 	if (nr > vc->vc_cols - vc->vc_x)
1611 		nr = vc->vc_cols - vc->vc_x;
1612 	else if (!nr)
1613 		nr = 1;
1614 	insert_char(vc, nr);
1615 }
1616 
1617 /* console_lock is held */
1618 static void csi_L(struct vc_data *vc, unsigned int nr)
1619 {
1620 	if (nr > vc->vc_rows - vc->vc_y)
1621 		nr = vc->vc_rows - vc->vc_y;
1622 	else if (!nr)
1623 		nr = 1;
1624 	scrdown(vc, vc->vc_y, vc->vc_bottom, nr);
1625 	vc->vc_need_wrap = 0;
1626 }
1627 
1628 /* console_lock is held */
1629 static void csi_P(struct vc_data *vc, unsigned int nr)
1630 {
1631 	if (nr > vc->vc_cols - vc->vc_x)
1632 		nr = vc->vc_cols - vc->vc_x;
1633 	else if (!nr)
1634 		nr = 1;
1635 	delete_char(vc, nr);
1636 }
1637 
1638 /* console_lock is held */
1639 static void csi_M(struct vc_data *vc, unsigned int nr)
1640 {
1641 	if (nr > vc->vc_rows - vc->vc_y)
1642 		nr = vc->vc_rows - vc->vc_y;
1643 	else if (!nr)
1644 		nr=1;
1645 	scrup(vc, vc->vc_y, vc->vc_bottom, nr);
1646 	vc->vc_need_wrap = 0;
1647 }
1648 
1649 /* console_lock is held (except via vc_init->reset_terminal */
1650 static void save_cur(struct vc_data *vc)
1651 {
1652 	vc->vc_saved_x		= vc->vc_x;
1653 	vc->vc_saved_y		= vc->vc_y;
1654 	vc->vc_s_intensity	= vc->vc_intensity;
1655 	vc->vc_s_italic         = vc->vc_italic;
1656 	vc->vc_s_underline	= vc->vc_underline;
1657 	vc->vc_s_blink		= vc->vc_blink;
1658 	vc->vc_s_reverse	= vc->vc_reverse;
1659 	vc->vc_s_charset	= vc->vc_charset;
1660 	vc->vc_s_color		= vc->vc_color;
1661 	vc->vc_saved_G0		= vc->vc_G0_charset;
1662 	vc->vc_saved_G1		= vc->vc_G1_charset;
1663 }
1664 
1665 /* console_lock is held */
1666 static void restore_cur(struct vc_data *vc)
1667 {
1668 	gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
1669 	vc->vc_intensity	= vc->vc_s_intensity;
1670 	vc->vc_italic		= vc->vc_s_italic;
1671 	vc->vc_underline	= vc->vc_s_underline;
1672 	vc->vc_blink		= vc->vc_s_blink;
1673 	vc->vc_reverse		= vc->vc_s_reverse;
1674 	vc->vc_charset		= vc->vc_s_charset;
1675 	vc->vc_color		= vc->vc_s_color;
1676 	vc->vc_G0_charset	= vc->vc_saved_G0;
1677 	vc->vc_G1_charset	= vc->vc_saved_G1;
1678 	vc->vc_translate	= set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
1679 	update_attr(vc);
1680 	vc->vc_need_wrap = 0;
1681 }
1682 
1683 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
1684 	EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
1685 	ESpalette, ESosc };
1686 
1687 /* console_lock is held (except via vc_init()) */
1688 static void reset_terminal(struct vc_data *vc, int do_clear)
1689 {
1690 	vc->vc_top		= 0;
1691 	vc->vc_bottom		= vc->vc_rows;
1692 	vc->vc_state		= ESnormal;
1693 	vc->vc_ques		= 0;
1694 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
1695 	vc->vc_G0_charset	= LAT1_MAP;
1696 	vc->vc_G1_charset	= GRAF_MAP;
1697 	vc->vc_charset		= 0;
1698 	vc->vc_need_wrap	= 0;
1699 	vc->vc_report_mouse	= 0;
1700 	vc->vc_utf              = default_utf8;
1701 	vc->vc_utf_count	= 0;
1702 
1703 	vc->vc_disp_ctrl	= 0;
1704 	vc->vc_toggle_meta	= 0;
1705 
1706 	vc->vc_decscnm		= 0;
1707 	vc->vc_decom		= 0;
1708 	vc->vc_decawm		= 1;
1709 	vc->vc_deccm		= global_cursor_default;
1710 	vc->vc_decim		= 0;
1711 
1712 	vt_reset_keyboard(vc->vc_num);
1713 
1714 	vc->vc_cursor_type = cur_default;
1715 	vc->vc_complement_mask = vc->vc_s_complement_mask;
1716 
1717 	default_attr(vc);
1718 	update_attr(vc);
1719 
1720 	vc->vc_tab_stop[0]	= 0x01010100;
1721 	vc->vc_tab_stop[1]	=
1722 	vc->vc_tab_stop[2]	=
1723 	vc->vc_tab_stop[3]	=
1724 	vc->vc_tab_stop[4]	=
1725 	vc->vc_tab_stop[5]	=
1726 	vc->vc_tab_stop[6]	=
1727 	vc->vc_tab_stop[7]	= 0x01010101;
1728 
1729 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1730 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1731 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1732 
1733 	gotoxy(vc, 0, 0);
1734 	save_cur(vc);
1735 	if (do_clear)
1736 	    csi_J(vc, 2);
1737 }
1738 
1739 /* console_lock is held */
1740 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
1741 {
1742 	/*
1743 	 *  Control characters can be used in the _middle_
1744 	 *  of an escape sequence.
1745 	 */
1746 	if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
1747 		return;
1748 	switch (c) {
1749 	case 0:
1750 		return;
1751 	case 7:
1752 		if (vc->vc_state == ESosc)
1753 			vc->vc_state = ESnormal;
1754 		else if (vc->vc_bell_duration)
1755 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
1756 		return;
1757 	case 8:
1758 		bs(vc);
1759 		return;
1760 	case 9:
1761 		vc->vc_pos -= (vc->vc_x << 1);
1762 		while (vc->vc_x < vc->vc_cols - 1) {
1763 			vc->vc_x++;
1764 			if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
1765 				break;
1766 		}
1767 		vc->vc_pos += (vc->vc_x << 1);
1768 		notify_write(vc, '\t');
1769 		return;
1770 	case 10: case 11: case 12:
1771 		lf(vc);
1772 		if (!is_kbd(vc, lnm))
1773 			return;
1774 	case 13:
1775 		cr(vc);
1776 		return;
1777 	case 14:
1778 		vc->vc_charset = 1;
1779 		vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
1780 		vc->vc_disp_ctrl = 1;
1781 		return;
1782 	case 15:
1783 		vc->vc_charset = 0;
1784 		vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
1785 		vc->vc_disp_ctrl = 0;
1786 		return;
1787 	case 24: case 26:
1788 		vc->vc_state = ESnormal;
1789 		return;
1790 	case 27:
1791 		vc->vc_state = ESesc;
1792 		return;
1793 	case 127:
1794 		del(vc);
1795 		return;
1796 	case 128+27:
1797 		vc->vc_state = ESsquare;
1798 		return;
1799 	}
1800 	switch(vc->vc_state) {
1801 	case ESesc:
1802 		vc->vc_state = ESnormal;
1803 		switch (c) {
1804 		case '[':
1805 			vc->vc_state = ESsquare;
1806 			return;
1807 		case ']':
1808 			vc->vc_state = ESnonstd;
1809 			return;
1810 		case '%':
1811 			vc->vc_state = ESpercent;
1812 			return;
1813 		case 'E':
1814 			cr(vc);
1815 			lf(vc);
1816 			return;
1817 		case 'M':
1818 			ri(vc);
1819 			return;
1820 		case 'D':
1821 			lf(vc);
1822 			return;
1823 		case 'H':
1824 			vc->vc_tab_stop[vc->vc_x >> 5] |= (1 << (vc->vc_x & 31));
1825 			return;
1826 		case 'Z':
1827 			respond_ID(tty);
1828 			return;
1829 		case '7':
1830 			save_cur(vc);
1831 			return;
1832 		case '8':
1833 			restore_cur(vc);
1834 			return;
1835 		case '(':
1836 			vc->vc_state = ESsetG0;
1837 			return;
1838 		case ')':
1839 			vc->vc_state = ESsetG1;
1840 			return;
1841 		case '#':
1842 			vc->vc_state = EShash;
1843 			return;
1844 		case 'c':
1845 			reset_terminal(vc, 1);
1846 			return;
1847 		case '>':  /* Numeric keypad */
1848 			clr_kbd(vc, kbdapplic);
1849 			return;
1850 		case '=':  /* Appl. keypad */
1851 			set_kbd(vc, kbdapplic);
1852 			return;
1853 		}
1854 		return;
1855 	case ESnonstd:
1856 		if (c=='P') {   /* palette escape sequence */
1857 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1858 				vc->vc_par[vc->vc_npar] = 0;
1859 			vc->vc_npar = 0;
1860 			vc->vc_state = ESpalette;
1861 			return;
1862 		} else if (c=='R') {   /* reset palette */
1863 			reset_palette(vc);
1864 			vc->vc_state = ESnormal;
1865 		} else if (c>='0' && c<='9')
1866 			vc->vc_state = ESosc;
1867 		else
1868 			vc->vc_state = ESnormal;
1869 		return;
1870 	case ESpalette:
1871 		if (isxdigit(c)) {
1872 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
1873 			if (vc->vc_npar == 7) {
1874 				int i = vc->vc_par[0] * 3, j = 1;
1875 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1876 				vc->vc_palette[i++] += vc->vc_par[j++];
1877 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1878 				vc->vc_palette[i++] += vc->vc_par[j++];
1879 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1880 				vc->vc_palette[i] += vc->vc_par[j];
1881 				set_palette(vc);
1882 				vc->vc_state = ESnormal;
1883 			}
1884 		} else
1885 			vc->vc_state = ESnormal;
1886 		return;
1887 	case ESsquare:
1888 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1889 			vc->vc_par[vc->vc_npar] = 0;
1890 		vc->vc_npar = 0;
1891 		vc->vc_state = ESgetpars;
1892 		if (c == '[') { /* Function key */
1893 			vc->vc_state=ESfunckey;
1894 			return;
1895 		}
1896 		vc->vc_ques = (c == '?');
1897 		if (vc->vc_ques)
1898 			return;
1899 	case ESgetpars:
1900 		if (c == ';' && vc->vc_npar < NPAR - 1) {
1901 			vc->vc_npar++;
1902 			return;
1903 		} else if (c>='0' && c<='9') {
1904 			vc->vc_par[vc->vc_npar] *= 10;
1905 			vc->vc_par[vc->vc_npar] += c - '0';
1906 			return;
1907 		}
1908 		vc->vc_state = ESnormal;
1909 		switch(c) {
1910 		case 'h':
1911 			set_mode(vc, 1);
1912 			return;
1913 		case 'l':
1914 			set_mode(vc, 0);
1915 			return;
1916 		case 'c':
1917 			if (vc->vc_ques) {
1918 				if (vc->vc_par[0])
1919 					vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
1920 				else
1921 					vc->vc_cursor_type = cur_default;
1922 				return;
1923 			}
1924 			break;
1925 		case 'm':
1926 			if (vc->vc_ques) {
1927 				clear_selection();
1928 				if (vc->vc_par[0])
1929 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
1930 				else
1931 					vc->vc_complement_mask = vc->vc_s_complement_mask;
1932 				return;
1933 			}
1934 			break;
1935 		case 'n':
1936 			if (!vc->vc_ques) {
1937 				if (vc->vc_par[0] == 5)
1938 					status_report(tty);
1939 				else if (vc->vc_par[0] == 6)
1940 					cursor_report(vc, tty);
1941 			}
1942 			return;
1943 		}
1944 		if (vc->vc_ques) {
1945 			vc->vc_ques = 0;
1946 			return;
1947 		}
1948 		switch(c) {
1949 		case 'G': case '`':
1950 			if (vc->vc_par[0])
1951 				vc->vc_par[0]--;
1952 			gotoxy(vc, vc->vc_par[0], vc->vc_y);
1953 			return;
1954 		case 'A':
1955 			if (!vc->vc_par[0])
1956 				vc->vc_par[0]++;
1957 			gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
1958 			return;
1959 		case 'B': case 'e':
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 'C': case 'a':
1965 			if (!vc->vc_par[0])
1966 				vc->vc_par[0]++;
1967 			gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
1968 			return;
1969 		case 'D':
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 'E':
1975 			if (!vc->vc_par[0])
1976 				vc->vc_par[0]++;
1977 			gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
1978 			return;
1979 		case 'F':
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 'd':
1985 			if (vc->vc_par[0])
1986 				vc->vc_par[0]--;
1987 			gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
1988 			return;
1989 		case 'H': case 'f':
1990 			if (vc->vc_par[0])
1991 				vc->vc_par[0]--;
1992 			if (vc->vc_par[1])
1993 				vc->vc_par[1]--;
1994 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
1995 			return;
1996 		case 'J':
1997 			csi_J(vc, vc->vc_par[0]);
1998 			return;
1999 		case 'K':
2000 			csi_K(vc, vc->vc_par[0]);
2001 			return;
2002 		case 'L':
2003 			csi_L(vc, vc->vc_par[0]);
2004 			return;
2005 		case 'M':
2006 			csi_M(vc, vc->vc_par[0]);
2007 			return;
2008 		case 'P':
2009 			csi_P(vc, vc->vc_par[0]);
2010 			return;
2011 		case 'c':
2012 			if (!vc->vc_par[0])
2013 				respond_ID(tty);
2014 			return;
2015 		case 'g':
2016 			if (!vc->vc_par[0])
2017 				vc->vc_tab_stop[vc->vc_x >> 5] &= ~(1 << (vc->vc_x & 31));
2018 			else if (vc->vc_par[0] == 3) {
2019 				vc->vc_tab_stop[0] =
2020 					vc->vc_tab_stop[1] =
2021 					vc->vc_tab_stop[2] =
2022 					vc->vc_tab_stop[3] =
2023 					vc->vc_tab_stop[4] =
2024 					vc->vc_tab_stop[5] =
2025 					vc->vc_tab_stop[6] =
2026 					vc->vc_tab_stop[7] = 0;
2027 			}
2028 			return;
2029 		case 'm':
2030 			csi_m(vc);
2031 			return;
2032 		case 'q': /* DECLL - but only 3 leds */
2033 			/* map 0,1,2,3 to 0,1,2,4 */
2034 			if (vc->vc_par[0] < 4)
2035 				vt_set_led_state(vc->vc_num,
2036 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2037 			return;
2038 		case 'r':
2039 			if (!vc->vc_par[0])
2040 				vc->vc_par[0]++;
2041 			if (!vc->vc_par[1])
2042 				vc->vc_par[1] = vc->vc_rows;
2043 			/* Minimum allowed region is 2 lines */
2044 			if (vc->vc_par[0] < vc->vc_par[1] &&
2045 			    vc->vc_par[1] <= vc->vc_rows) {
2046 				vc->vc_top = vc->vc_par[0] - 1;
2047 				vc->vc_bottom = vc->vc_par[1];
2048 				gotoxay(vc, 0, 0);
2049 			}
2050 			return;
2051 		case 's':
2052 			save_cur(vc);
2053 			return;
2054 		case 'u':
2055 			restore_cur(vc);
2056 			return;
2057 		case 'X':
2058 			csi_X(vc, vc->vc_par[0]);
2059 			return;
2060 		case '@':
2061 			csi_at(vc, vc->vc_par[0]);
2062 			return;
2063 		case ']': /* setterm functions */
2064 			setterm_command(vc);
2065 			return;
2066 		}
2067 		return;
2068 	case ESpercent:
2069 		vc->vc_state = ESnormal;
2070 		switch (c) {
2071 		case '@':  /* defined in ISO 2022 */
2072 			vc->vc_utf = 0;
2073 			return;
2074 		case 'G':  /* prelim official escape code */
2075 		case '8':  /* retained for compatibility */
2076 			vc->vc_utf = 1;
2077 			return;
2078 		}
2079 		return;
2080 	case ESfunckey:
2081 		vc->vc_state = ESnormal;
2082 		return;
2083 	case EShash:
2084 		vc->vc_state = ESnormal;
2085 		if (c == '8') {
2086 			/* DEC screen alignment test. kludge :-) */
2087 			vc->vc_video_erase_char =
2088 				(vc->vc_video_erase_char & 0xff00) | 'E';
2089 			csi_J(vc, 2);
2090 			vc->vc_video_erase_char =
2091 				(vc->vc_video_erase_char & 0xff00) | ' ';
2092 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2093 		}
2094 		return;
2095 	case ESsetG0:
2096 		if (c == '0')
2097 			vc->vc_G0_charset = GRAF_MAP;
2098 		else if (c == 'B')
2099 			vc->vc_G0_charset = LAT1_MAP;
2100 		else if (c == 'U')
2101 			vc->vc_G0_charset = IBMPC_MAP;
2102 		else if (c == 'K')
2103 			vc->vc_G0_charset = USER_MAP;
2104 		if (vc->vc_charset == 0)
2105 			vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2106 		vc->vc_state = ESnormal;
2107 		return;
2108 	case ESsetG1:
2109 		if (c == '0')
2110 			vc->vc_G1_charset = GRAF_MAP;
2111 		else if (c == 'B')
2112 			vc->vc_G1_charset = LAT1_MAP;
2113 		else if (c == 'U')
2114 			vc->vc_G1_charset = IBMPC_MAP;
2115 		else if (c == 'K')
2116 			vc->vc_G1_charset = USER_MAP;
2117 		if (vc->vc_charset == 1)
2118 			vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2119 		vc->vc_state = ESnormal;
2120 		return;
2121 	case ESosc:
2122 		return;
2123 	default:
2124 		vc->vc_state = ESnormal;
2125 	}
2126 }
2127 
2128 /* is_double_width() is based on the wcwidth() implementation by
2129  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2130  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2131  */
2132 struct interval {
2133 	uint32_t first;
2134 	uint32_t last;
2135 };
2136 
2137 static int bisearch(uint32_t ucs, const struct interval *table, int max)
2138 {
2139 	int min = 0;
2140 	int mid;
2141 
2142 	if (ucs < table[0].first || ucs > table[max].last)
2143 		return 0;
2144 	while (max >= min) {
2145 		mid = (min + max) / 2;
2146 		if (ucs > table[mid].last)
2147 			min = mid + 1;
2148 		else if (ucs < table[mid].first)
2149 			max = mid - 1;
2150 		else
2151 			return 1;
2152 	}
2153 	return 0;
2154 }
2155 
2156 static int is_double_width(uint32_t ucs)
2157 {
2158 	static const struct interval double_width[] = {
2159 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2160 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2161 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2162 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2163 	};
2164 	return bisearch(ucs, double_width, ARRAY_SIZE(double_width) - 1);
2165 }
2166 
2167 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2168 		unsigned long draw_to, int *draw_x)
2169 {
2170 	if (*draw_x < 0)
2171 		return;
2172 
2173 	vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2174 			(u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2175 	*draw_x = -1;
2176 }
2177 
2178 /* acquires console_lock */
2179 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2180 {
2181 	int c, tc, ok, n = 0, draw_x = -1;
2182 	unsigned int currcons;
2183 	unsigned long draw_from = 0, draw_to = 0;
2184 	struct vc_data *vc;
2185 	unsigned char vc_attr;
2186 	struct vt_notifier_param param;
2187 	uint8_t rescan;
2188 	uint8_t inverse;
2189 	uint8_t width;
2190 	u16 himask, charmask;
2191 
2192 	if (in_interrupt())
2193 		return count;
2194 
2195 	might_sleep();
2196 
2197 	console_lock();
2198 	vc = tty->driver_data;
2199 	if (vc == NULL) {
2200 		printk(KERN_ERR "vt: argh, driver_data is NULL !\n");
2201 		console_unlock();
2202 		return 0;
2203 	}
2204 
2205 	currcons = vc->vc_num;
2206 	if (!vc_cons_allocated(currcons)) {
2207 		/* could this happen? */
2208 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2209 		console_unlock();
2210 		return 0;
2211 	}
2212 
2213 	himask = vc->vc_hi_font_mask;
2214 	charmask = himask ? 0x1ff : 0xff;
2215 
2216 	/* undraw cursor first */
2217 	if (con_is_fg(vc))
2218 		hide_cursor(vc);
2219 
2220 	param.vc = vc;
2221 
2222 	while (!tty->stopped && count) {
2223 		int orig = *buf;
2224 		c = orig;
2225 		buf++;
2226 		n++;
2227 		count--;
2228 		rescan = 0;
2229 		inverse = 0;
2230 		width = 1;
2231 
2232 		/* Do no translation at all in control states */
2233 		if (vc->vc_state != ESnormal) {
2234 			tc = c;
2235 		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2236 		    /* Combine UTF-8 into Unicode in vc_utf_char.
2237 		     * vc_utf_count is the number of continuation bytes still
2238 		     * expected to arrive.
2239 		     * vc_npar is the number of continuation bytes arrived so
2240 		     * far
2241 		     */
2242 rescan_last_byte:
2243 		    if ((c & 0xc0) == 0x80) {
2244 			/* Continuation byte received */
2245 			static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2246 			if (vc->vc_utf_count) {
2247 			    vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2248 			    vc->vc_npar++;
2249 			    if (--vc->vc_utf_count) {
2250 				/* Still need some bytes */
2251 				continue;
2252 			    }
2253 			    /* Got a whole character */
2254 			    c = vc->vc_utf_char;
2255 			    /* Reject overlong sequences */
2256 			    if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2257 					c > utf8_length_changes[vc->vc_npar])
2258 				c = 0xfffd;
2259 			} else {
2260 			    /* Unexpected continuation byte */
2261 			    vc->vc_utf_count = 0;
2262 			    c = 0xfffd;
2263 			}
2264 		    } else {
2265 			/* Single ASCII byte or first byte of a sequence received */
2266 			if (vc->vc_utf_count) {
2267 			    /* Continuation byte expected */
2268 			    rescan = 1;
2269 			    vc->vc_utf_count = 0;
2270 			    c = 0xfffd;
2271 			} else if (c > 0x7f) {
2272 			    /* First byte of a multibyte sequence received */
2273 			    vc->vc_npar = 0;
2274 			    if ((c & 0xe0) == 0xc0) {
2275 				vc->vc_utf_count = 1;
2276 				vc->vc_utf_char = (c & 0x1f);
2277 			    } else if ((c & 0xf0) == 0xe0) {
2278 				vc->vc_utf_count = 2;
2279 				vc->vc_utf_char = (c & 0x0f);
2280 			    } else if ((c & 0xf8) == 0xf0) {
2281 				vc->vc_utf_count = 3;
2282 				vc->vc_utf_char = (c & 0x07);
2283 			    } else if ((c & 0xfc) == 0xf8) {
2284 				vc->vc_utf_count = 4;
2285 				vc->vc_utf_char = (c & 0x03);
2286 			    } else if ((c & 0xfe) == 0xfc) {
2287 				vc->vc_utf_count = 5;
2288 				vc->vc_utf_char = (c & 0x01);
2289 			    } else {
2290 				/* 254 and 255 are invalid */
2291 				c = 0xfffd;
2292 			    }
2293 			    if (vc->vc_utf_count) {
2294 				/* Still need some bytes */
2295 				continue;
2296 			    }
2297 			}
2298 			/* Nothing to do if an ASCII byte was received */
2299 		    }
2300 		    /* End of UTF-8 decoding. */
2301 		    /* c is the received character, or U+FFFD for invalid sequences. */
2302 		    /* Replace invalid Unicode code points with U+FFFD too */
2303 		    if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2304 			c = 0xfffd;
2305 		    tc = c;
2306 		} else {	/* no utf or alternate charset mode */
2307 		    tc = vc_translate(vc, c);
2308 		}
2309 
2310 		param.c = tc;
2311 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2312 					&param) == NOTIFY_STOP)
2313 			continue;
2314 
2315                 /* If the original code was a control character we
2316                  * only allow a glyph to be displayed if the code is
2317                  * not normally used (such as for cursor movement) or
2318                  * if the disp_ctrl mode has been explicitly enabled.
2319                  * Certain characters (as given by the CTRL_ALWAYS
2320                  * bitmap) are always displayed as control characters,
2321                  * as the console would be pretty useless without
2322                  * them; to display an arbitrary font position use the
2323                  * direct-to-font zone in UTF-8 mode.
2324                  */
2325                 ok = tc && (c >= 32 ||
2326 			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2327 				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2328 			&& (c != 127 || vc->vc_disp_ctrl)
2329 			&& (c != 128+27);
2330 
2331 		if (vc->vc_state == ESnormal && ok) {
2332 			if (vc->vc_utf && !vc->vc_disp_ctrl) {
2333 				if (is_double_width(c))
2334 					width = 2;
2335 			}
2336 			/* Now try to find out how to display it */
2337 			tc = conv_uni_to_pc(vc, tc);
2338 			if (tc & ~charmask) {
2339 				if (tc == -1 || tc == -2) {
2340 				    continue; /* nothing to display */
2341 				}
2342 				/* Glyph not found */
2343 				if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2344 				    /* In legacy mode use the glyph we get by a 1:1 mapping.
2345 				       This would make absolutely no sense with Unicode in mind,
2346 				       but do this for ASCII characters since a font may lack
2347 				       Unicode mapping info and we don't want to end up with
2348 				       having question marks only. */
2349 				    tc = c;
2350 				} else {
2351 				    /* Display U+FFFD. If it's not found, display an inverse question mark. */
2352 				    tc = conv_uni_to_pc(vc, 0xfffd);
2353 				    if (tc < 0) {
2354 					inverse = 1;
2355 					tc = conv_uni_to_pc(vc, '?');
2356 					if (tc < 0) tc = '?';
2357 				    }
2358 				}
2359 			}
2360 
2361 			if (!inverse) {
2362 				vc_attr = vc->vc_attr;
2363 			} else {
2364 				/* invert vc_attr */
2365 				if (!vc->vc_can_do_color) {
2366 					vc_attr = (vc->vc_attr) ^ 0x08;
2367 				} else if (vc->vc_hi_font_mask == 0x100) {
2368 					vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2369 				} else {
2370 					vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2371 				}
2372 				con_flush(vc, draw_from, draw_to, &draw_x);
2373 			}
2374 
2375 			while (1) {
2376 				if (vc->vc_need_wrap || vc->vc_decim)
2377 					con_flush(vc, draw_from, draw_to,
2378 							&draw_x);
2379 				if (vc->vc_need_wrap) {
2380 					cr(vc);
2381 					lf(vc);
2382 				}
2383 				if (vc->vc_decim)
2384 					insert_char(vc, 1);
2385 				scr_writew(himask ?
2386 					     ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2387 					     (vc_attr << 8) + tc,
2388 					   (u16 *) vc->vc_pos);
2389 				if (con_should_update(vc) && draw_x < 0) {
2390 					draw_x = vc->vc_x;
2391 					draw_from = vc->vc_pos;
2392 				}
2393 				if (vc->vc_x == vc->vc_cols - 1) {
2394 					vc->vc_need_wrap = vc->vc_decawm;
2395 					draw_to = vc->vc_pos + 2;
2396 				} else {
2397 					vc->vc_x++;
2398 					draw_to = (vc->vc_pos += 2);
2399 				}
2400 
2401 				if (!--width) break;
2402 
2403 				tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2404 				if (tc < 0) tc = ' ';
2405 			}
2406 			notify_write(vc, c);
2407 
2408 			if (inverse)
2409 				con_flush(vc, draw_from, draw_to, &draw_x);
2410 
2411 			if (rescan) {
2412 				rescan = 0;
2413 				inverse = 0;
2414 				width = 1;
2415 				c = orig;
2416 				goto rescan_last_byte;
2417 			}
2418 			continue;
2419 		}
2420 		con_flush(vc, draw_from, draw_to, &draw_x);
2421 		do_con_trol(tty, vc, orig);
2422 	}
2423 	con_flush(vc, draw_from, draw_to, &draw_x);
2424 	console_conditional_schedule();
2425 	console_unlock();
2426 	notify_update(vc);
2427 	return n;
2428 }
2429 
2430 /*
2431  * This is the console switching callback.
2432  *
2433  * Doing console switching in a process context allows
2434  * us to do the switches asynchronously (needed when we want
2435  * to switch due to a keyboard interrupt).  Synchronization
2436  * with other console code and prevention of re-entrancy is
2437  * ensured with console_lock.
2438  */
2439 static void console_callback(struct work_struct *ignored)
2440 {
2441 	console_lock();
2442 
2443 	if (want_console >= 0) {
2444 		if (want_console != fg_console &&
2445 		    vc_cons_allocated(want_console)) {
2446 			hide_cursor(vc_cons[fg_console].d);
2447 			change_console(vc_cons[want_console].d);
2448 			/* we only changed when the console had already
2449 			   been allocated - a new console is not created
2450 			   in an interrupt routine */
2451 		}
2452 		want_console = -1;
2453 	}
2454 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2455 		do_poke_blanked_console = 0;
2456 		poke_blanked_console();
2457 	}
2458 	if (scrollback_delta) {
2459 		struct vc_data *vc = vc_cons[fg_console].d;
2460 		clear_selection();
2461 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2462 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2463 		scrollback_delta = 0;
2464 	}
2465 	if (blank_timer_expired) {
2466 		do_blank_screen(0);
2467 		blank_timer_expired = 0;
2468 	}
2469 	notify_update(vc_cons[fg_console].d);
2470 
2471 	console_unlock();
2472 }
2473 
2474 int set_console(int nr)
2475 {
2476 	struct vc_data *vc = vc_cons[fg_console].d;
2477 
2478 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
2479 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2480 
2481 		/*
2482 		 * Console switch will fail in console_callback() or
2483 		 * change_console() so there is no point scheduling
2484 		 * the callback
2485 		 *
2486 		 * Existing set_console() users don't check the return
2487 		 * value so this shouldn't break anything
2488 		 */
2489 		return -EINVAL;
2490 	}
2491 
2492 	want_console = nr;
2493 	schedule_console_callback();
2494 
2495 	return 0;
2496 }
2497 
2498 struct tty_driver *console_driver;
2499 
2500 #ifdef CONFIG_VT_CONSOLE
2501 
2502 /**
2503  * vt_kmsg_redirect() - Sets/gets the kernel message console
2504  * @new:	The new virtual terminal number or -1 if the console should stay
2505  * 		unchanged
2506  *
2507  * By default, the kernel messages are always printed on the current virtual
2508  * console. However, the user may modify that default with the
2509  * TIOCL_SETKMSGREDIRECT ioctl call.
2510  *
2511  * This function sets the kernel message console to be @new. It returns the old
2512  * virtual console number. The virtual terminal number 0 (both as parameter and
2513  * return value) means no redirection (i.e. always printed on the currently
2514  * active console).
2515  *
2516  * The parameter -1 means that only the current console is returned, but the
2517  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2518  * case to make the code more understandable.
2519  *
2520  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2521  * the parameter and always returns 0.
2522  */
2523 int vt_kmsg_redirect(int new)
2524 {
2525 	static int kmsg_con;
2526 
2527 	if (new != -1)
2528 		return xchg(&kmsg_con, new);
2529 	else
2530 		return kmsg_con;
2531 }
2532 
2533 /*
2534  *	Console on virtual terminal
2535  *
2536  * The console must be locked when we get here.
2537  */
2538 
2539 static void vt_console_print(struct console *co, const char *b, unsigned count)
2540 {
2541 	struct vc_data *vc = vc_cons[fg_console].d;
2542 	unsigned char c;
2543 	static DEFINE_SPINLOCK(printing_lock);
2544 	const ushort *start;
2545 	ushort cnt = 0;
2546 	ushort myx;
2547 	int kmsg_console;
2548 
2549 	/* console busy or not yet initialized */
2550 	if (!printable)
2551 		return;
2552 	if (!spin_trylock(&printing_lock))
2553 		return;
2554 
2555 	kmsg_console = vt_get_kmsg_redirect();
2556 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2557 		vc = vc_cons[kmsg_console - 1].d;
2558 
2559 	/* read `x' only after setting currcons properly (otherwise
2560 	   the `x' macro will read the x of the foreground console). */
2561 	myx = vc->vc_x;
2562 
2563 	if (!vc_cons_allocated(fg_console)) {
2564 		/* impossible */
2565 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2566 		goto quit;
2567 	}
2568 
2569 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
2570 		goto quit;
2571 
2572 	/* undraw cursor first */
2573 	if (con_is_fg(vc))
2574 		hide_cursor(vc);
2575 
2576 	start = (ushort *)vc->vc_pos;
2577 
2578 	/* Contrived structure to try to emulate original need_wrap behaviour
2579 	 * Problems caused when we have need_wrap set on '\n' character */
2580 	while (count--) {
2581 		c = *b++;
2582 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2583 			if (cnt > 0) {
2584 				if (con_is_visible(vc))
2585 					vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2586 				vc->vc_x += cnt;
2587 				if (vc->vc_need_wrap)
2588 					vc->vc_x--;
2589 				cnt = 0;
2590 			}
2591 			if (c == 8) {		/* backspace */
2592 				bs(vc);
2593 				start = (ushort *)vc->vc_pos;
2594 				myx = vc->vc_x;
2595 				continue;
2596 			}
2597 			if (c != 13)
2598 				lf(vc);
2599 			cr(vc);
2600 			start = (ushort *)vc->vc_pos;
2601 			myx = vc->vc_x;
2602 			if (c == 10 || c == 13)
2603 				continue;
2604 		}
2605 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2606 		notify_write(vc, c);
2607 		cnt++;
2608 		if (myx == vc->vc_cols - 1) {
2609 			vc->vc_need_wrap = 1;
2610 			continue;
2611 		}
2612 		vc->vc_pos += 2;
2613 		myx++;
2614 	}
2615 	if (cnt > 0) {
2616 		if (con_is_visible(vc))
2617 			vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2618 		vc->vc_x += cnt;
2619 		if (vc->vc_x == vc->vc_cols) {
2620 			vc->vc_x--;
2621 			vc->vc_need_wrap = 1;
2622 		}
2623 	}
2624 	set_cursor(vc);
2625 	notify_update(vc);
2626 
2627 quit:
2628 	spin_unlock(&printing_lock);
2629 }
2630 
2631 static struct tty_driver *vt_console_device(struct console *c, int *index)
2632 {
2633 	*index = c->index ? c->index-1 : fg_console;
2634 	return console_driver;
2635 }
2636 
2637 static struct console vt_console_driver = {
2638 	.name		= "tty",
2639 	.write		= vt_console_print,
2640 	.device		= vt_console_device,
2641 	.unblank	= unblank_screen,
2642 	.flags		= CON_PRINTBUFFER,
2643 	.index		= -1,
2644 };
2645 #endif
2646 
2647 /*
2648  *	Handling of Linux-specific VC ioctls
2649  */
2650 
2651 /*
2652  * Generally a bit racy with respect to console_lock();.
2653  *
2654  * There are some functions which don't need it.
2655  *
2656  * There are some functions which can sleep for arbitrary periods
2657  * (paste_selection) but we don't need the lock there anyway.
2658  *
2659  * set_selection has locking, and definitely needs it
2660  */
2661 
2662 int tioclinux(struct tty_struct *tty, unsigned long arg)
2663 {
2664 	char type, data;
2665 	char __user *p = (char __user *)arg;
2666 	int lines;
2667 	int ret;
2668 
2669 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
2670 		return -EPERM;
2671 	if (get_user(type, p))
2672 		return -EFAULT;
2673 	ret = 0;
2674 
2675 	switch (type)
2676 	{
2677 		case TIOCL_SETSEL:
2678 			console_lock();
2679 			ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
2680 			console_unlock();
2681 			break;
2682 		case TIOCL_PASTESEL:
2683 			ret = paste_selection(tty);
2684 			break;
2685 		case TIOCL_UNBLANKSCREEN:
2686 			console_lock();
2687 			unblank_screen();
2688 			console_unlock();
2689 			break;
2690 		case TIOCL_SELLOADLUT:
2691 			console_lock();
2692 			ret = sel_loadlut(p);
2693 			console_unlock();
2694 			break;
2695 		case TIOCL_GETSHIFTSTATE:
2696 
2697 	/*
2698 	 * Make it possible to react to Shift+Mousebutton.
2699 	 * Note that 'shift_state' is an undocumented
2700 	 * kernel-internal variable; programs not closely
2701 	 * related to the kernel should not use this.
2702 	 */
2703 			data = vt_get_shift_state();
2704 			ret = __put_user(data, p);
2705 			break;
2706 		case TIOCL_GETMOUSEREPORTING:
2707 			console_lock();	/* May be overkill */
2708 			data = mouse_reporting();
2709 			console_unlock();
2710 			ret = __put_user(data, p);
2711 			break;
2712 		case TIOCL_SETVESABLANK:
2713 			console_lock();
2714 			ret = set_vesa_blanking(p);
2715 			console_unlock();
2716 			break;
2717 		case TIOCL_GETKMSGREDIRECT:
2718 			data = vt_get_kmsg_redirect();
2719 			ret = __put_user(data, p);
2720 			break;
2721 		case TIOCL_SETKMSGREDIRECT:
2722 			if (!capable(CAP_SYS_ADMIN)) {
2723 				ret = -EPERM;
2724 			} else {
2725 				if (get_user(data, p+1))
2726 					ret = -EFAULT;
2727 				else
2728 					vt_kmsg_redirect(data);
2729 			}
2730 			break;
2731 		case TIOCL_GETFGCONSOLE:
2732 			/* No locking needed as this is a transiently
2733 			   correct return anyway if the caller hasn't
2734 			   disabled switching */
2735 			ret = fg_console;
2736 			break;
2737 		case TIOCL_SCROLLCONSOLE:
2738 			if (get_user(lines, (s32 __user *)(p+4))) {
2739 				ret = -EFAULT;
2740 			} else {
2741 				/* Need the console lock here. Note that lots
2742 				   of other calls need fixing before the lock
2743 				   is actually useful ! */
2744 				console_lock();
2745 				scrollfront(vc_cons[fg_console].d, lines);
2746 				console_unlock();
2747 				ret = 0;
2748 			}
2749 			break;
2750 		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
2751 			console_lock();
2752 			ignore_poke = 1;
2753 			do_blank_screen(0);
2754 			console_unlock();
2755 			break;
2756 		case TIOCL_BLANKEDSCREEN:
2757 			ret = console_blanked;
2758 			break;
2759 		default:
2760 			ret = -EINVAL;
2761 			break;
2762 	}
2763 	return ret;
2764 }
2765 
2766 /*
2767  * /dev/ttyN handling
2768  */
2769 
2770 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2771 {
2772 	int	retval;
2773 
2774 	retval = do_con_write(tty, buf, count);
2775 	con_flush_chars(tty);
2776 
2777 	return retval;
2778 }
2779 
2780 static int con_put_char(struct tty_struct *tty, unsigned char ch)
2781 {
2782 	if (in_interrupt())
2783 		return 0;	/* n_r3964 calls put_char() from interrupt context */
2784 	return do_con_write(tty, &ch, 1);
2785 }
2786 
2787 static int con_write_room(struct tty_struct *tty)
2788 {
2789 	if (tty->stopped)
2790 		return 0;
2791 	return 32768;		/* No limit, really; we're not buffering */
2792 }
2793 
2794 static int con_chars_in_buffer(struct tty_struct *tty)
2795 {
2796 	return 0;		/* we're not buffering */
2797 }
2798 
2799 /*
2800  * con_throttle and con_unthrottle are only used for
2801  * paste_selection(), which has to stuff in a large number of
2802  * characters...
2803  */
2804 static void con_throttle(struct tty_struct *tty)
2805 {
2806 }
2807 
2808 static void con_unthrottle(struct tty_struct *tty)
2809 {
2810 	struct vc_data *vc = tty->driver_data;
2811 
2812 	wake_up_interruptible(&vc->paste_wait);
2813 }
2814 
2815 /*
2816  * Turn the Scroll-Lock LED on when the tty is stopped
2817  */
2818 static void con_stop(struct tty_struct *tty)
2819 {
2820 	int console_num;
2821 	if (!tty)
2822 		return;
2823 	console_num = tty->index;
2824 	if (!vc_cons_allocated(console_num))
2825 		return;
2826 	vt_kbd_con_stop(console_num);
2827 }
2828 
2829 /*
2830  * Turn the Scroll-Lock LED off when the console is started
2831  */
2832 static void con_start(struct tty_struct *tty)
2833 {
2834 	int console_num;
2835 	if (!tty)
2836 		return;
2837 	console_num = tty->index;
2838 	if (!vc_cons_allocated(console_num))
2839 		return;
2840 	vt_kbd_con_start(console_num);
2841 }
2842 
2843 static void con_flush_chars(struct tty_struct *tty)
2844 {
2845 	struct vc_data *vc;
2846 
2847 	if (in_interrupt())	/* from flush_to_ldisc */
2848 		return;
2849 
2850 	/* if we race with con_close(), vt may be null */
2851 	console_lock();
2852 	vc = tty->driver_data;
2853 	if (vc)
2854 		set_cursor(vc);
2855 	console_unlock();
2856 }
2857 
2858 /*
2859  * Allocate the console screen memory.
2860  */
2861 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
2862 {
2863 	unsigned int currcons = tty->index;
2864 	struct vc_data *vc;
2865 	int ret;
2866 
2867 	console_lock();
2868 	ret = vc_allocate(currcons);
2869 	if (ret)
2870 		goto unlock;
2871 
2872 	vc = vc_cons[currcons].d;
2873 
2874 	/* Still being freed */
2875 	if (vc->port.tty) {
2876 		ret = -ERESTARTSYS;
2877 		goto unlock;
2878 	}
2879 
2880 	ret = tty_port_install(&vc->port, driver, tty);
2881 	if (ret)
2882 		goto unlock;
2883 
2884 	tty->driver_data = vc;
2885 	vc->port.tty = tty;
2886 
2887 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
2888 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
2889 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
2890 	}
2891 	if (vc->vc_utf)
2892 		tty->termios.c_iflag |= IUTF8;
2893 	else
2894 		tty->termios.c_iflag &= ~IUTF8;
2895 unlock:
2896 	console_unlock();
2897 	return ret;
2898 }
2899 
2900 static int con_open(struct tty_struct *tty, struct file *filp)
2901 {
2902 	/* everything done in install */
2903 	return 0;
2904 }
2905 
2906 
2907 static void con_close(struct tty_struct *tty, struct file *filp)
2908 {
2909 	/* Nothing to do - we defer to shutdown */
2910 }
2911 
2912 static void con_shutdown(struct tty_struct *tty)
2913 {
2914 	struct vc_data *vc = tty->driver_data;
2915 	BUG_ON(vc == NULL);
2916 	console_lock();
2917 	vc->port.tty = NULL;
2918 	console_unlock();
2919 }
2920 
2921 static int default_color           = 7; /* white */
2922 static int default_italic_color    = 2; // green (ASCII)
2923 static int default_underline_color = 3; // cyan (ASCII)
2924 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
2925 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
2926 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
2927 
2928 static void vc_init(struct vc_data *vc, unsigned int rows,
2929 		    unsigned int cols, int do_clear)
2930 {
2931 	int j, k ;
2932 
2933 	vc->vc_cols = cols;
2934 	vc->vc_rows = rows;
2935 	vc->vc_size_row = cols << 1;
2936 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
2937 
2938 	set_origin(vc);
2939 	vc->vc_pos = vc->vc_origin;
2940 	reset_vc(vc);
2941 	for (j=k=0; j<16; j++) {
2942 		vc->vc_palette[k++] = default_red[j] ;
2943 		vc->vc_palette[k++] = default_grn[j] ;
2944 		vc->vc_palette[k++] = default_blu[j] ;
2945 	}
2946 	vc->vc_def_color       = default_color;
2947 	vc->vc_ulcolor         = default_underline_color;
2948 	vc->vc_itcolor         = default_italic_color;
2949 	vc->vc_halfcolor       = 0x08;   /* grey */
2950 	init_waitqueue_head(&vc->paste_wait);
2951 	reset_terminal(vc, do_clear);
2952 }
2953 
2954 /*
2955  * This routine initializes console interrupts, and does nothing
2956  * else. If you want the screen to clear, call tty_write with
2957  * the appropriate escape-sequence.
2958  */
2959 
2960 static int __init con_init(void)
2961 {
2962 	const char *display_desc = NULL;
2963 	struct vc_data *vc;
2964 	unsigned int currcons = 0, i;
2965 
2966 	console_lock();
2967 
2968 	if (conswitchp)
2969 		display_desc = conswitchp->con_startup();
2970 	if (!display_desc) {
2971 		fg_console = 0;
2972 		console_unlock();
2973 		return 0;
2974 	}
2975 
2976 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
2977 		struct con_driver *con_driver = &registered_con_driver[i];
2978 
2979 		if (con_driver->con == NULL) {
2980 			con_driver->con = conswitchp;
2981 			con_driver->desc = display_desc;
2982 			con_driver->flag = CON_DRIVER_FLAG_INIT;
2983 			con_driver->first = 0;
2984 			con_driver->last = MAX_NR_CONSOLES - 1;
2985 			break;
2986 		}
2987 	}
2988 
2989 	for (i = 0; i < MAX_NR_CONSOLES; i++)
2990 		con_driver_map[i] = conswitchp;
2991 
2992 	if (blankinterval) {
2993 		blank_state = blank_normal_wait;
2994 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
2995 	}
2996 
2997 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
2998 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
2999 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3000 		tty_port_init(&vc->port);
3001 		visual_init(vc, currcons, 1);
3002 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3003 		vc_init(vc, vc->vc_rows, vc->vc_cols,
3004 			currcons || !vc->vc_sw->con_save_screen);
3005 	}
3006 	currcons = fg_console = 0;
3007 	master_display_fg = vc = vc_cons[currcons].d;
3008 	set_origin(vc);
3009 	save_screen(vc);
3010 	gotoxy(vc, vc->vc_x, vc->vc_y);
3011 	csi_J(vc, 0);
3012 	update_screen(vc);
3013 	pr_info("Console: %s %s %dx%d\n",
3014 		vc->vc_can_do_color ? "colour" : "mono",
3015 		display_desc, vc->vc_cols, vc->vc_rows);
3016 	printable = 1;
3017 
3018 	console_unlock();
3019 
3020 #ifdef CONFIG_VT_CONSOLE
3021 	register_console(&vt_console_driver);
3022 #endif
3023 	return 0;
3024 }
3025 console_initcall(con_init);
3026 
3027 static const struct tty_operations con_ops = {
3028 	.install = con_install,
3029 	.open = con_open,
3030 	.close = con_close,
3031 	.write = con_write,
3032 	.write_room = con_write_room,
3033 	.put_char = con_put_char,
3034 	.flush_chars = con_flush_chars,
3035 	.chars_in_buffer = con_chars_in_buffer,
3036 	.ioctl = vt_ioctl,
3037 #ifdef CONFIG_COMPAT
3038 	.compat_ioctl = vt_compat_ioctl,
3039 #endif
3040 	.stop = con_stop,
3041 	.start = con_start,
3042 	.throttle = con_throttle,
3043 	.unthrottle = con_unthrottle,
3044 	.resize = vt_resize,
3045 	.shutdown = con_shutdown
3046 };
3047 
3048 static struct cdev vc0_cdev;
3049 
3050 static ssize_t show_tty_active(struct device *dev,
3051 				struct device_attribute *attr, char *buf)
3052 {
3053 	return sprintf(buf, "tty%d\n", fg_console + 1);
3054 }
3055 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3056 
3057 static struct attribute *vt_dev_attrs[] = {
3058 	&dev_attr_active.attr,
3059 	NULL
3060 };
3061 
3062 ATTRIBUTE_GROUPS(vt_dev);
3063 
3064 int __init vty_init(const struct file_operations *console_fops)
3065 {
3066 	cdev_init(&vc0_cdev, console_fops);
3067 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3068 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3069 		panic("Couldn't register /dev/tty0 driver\n");
3070 	tty0dev = device_create_with_groups(tty_class, NULL,
3071 					    MKDEV(TTY_MAJOR, 0), NULL,
3072 					    vt_dev_groups, "tty0");
3073 	if (IS_ERR(tty0dev))
3074 		tty0dev = NULL;
3075 
3076 	vcs_init();
3077 
3078 	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3079 	if (!console_driver)
3080 		panic("Couldn't allocate console driver\n");
3081 
3082 	console_driver->name = "tty";
3083 	console_driver->name_base = 1;
3084 	console_driver->major = TTY_MAJOR;
3085 	console_driver->minor_start = 1;
3086 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3087 	console_driver->init_termios = tty_std_termios;
3088 	if (default_utf8)
3089 		console_driver->init_termios.c_iflag |= IUTF8;
3090 	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3091 	tty_set_operations(console_driver, &con_ops);
3092 	if (tty_register_driver(console_driver))
3093 		panic("Couldn't register console driver\n");
3094 	kbd_init();
3095 	console_map_init();
3096 #ifdef CONFIG_MDA_CONSOLE
3097 	mda_console_init();
3098 #endif
3099 	return 0;
3100 }
3101 
3102 #ifndef VT_SINGLE_DRIVER
3103 
3104 static struct class *vtconsole_class;
3105 
3106 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3107 			   int deflt)
3108 {
3109 	struct module *owner = csw->owner;
3110 	const char *desc = NULL;
3111 	struct con_driver *con_driver;
3112 	int i, j = -1, k = -1, retval = -ENODEV;
3113 
3114 	if (!try_module_get(owner))
3115 		return -ENODEV;
3116 
3117 	WARN_CONSOLE_UNLOCKED();
3118 
3119 	/* check if driver is registered */
3120 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3121 		con_driver = &registered_con_driver[i];
3122 
3123 		if (con_driver->con == csw) {
3124 			desc = con_driver->desc;
3125 			retval = 0;
3126 			break;
3127 		}
3128 	}
3129 
3130 	if (retval)
3131 		goto err;
3132 
3133 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3134 		csw->con_startup();
3135 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3136 	}
3137 
3138 	if (deflt) {
3139 		if (conswitchp)
3140 			module_put(conswitchp->owner);
3141 
3142 		__module_get(owner);
3143 		conswitchp = csw;
3144 	}
3145 
3146 	first = max(first, con_driver->first);
3147 	last = min(last, con_driver->last);
3148 
3149 	for (i = first; i <= last; i++) {
3150 		int old_was_color;
3151 		struct vc_data *vc = vc_cons[i].d;
3152 
3153 		if (con_driver_map[i])
3154 			module_put(con_driver_map[i]->owner);
3155 		__module_get(owner);
3156 		con_driver_map[i] = csw;
3157 
3158 		if (!vc || !vc->vc_sw)
3159 			continue;
3160 
3161 		j = i;
3162 
3163 		if (con_is_visible(vc)) {
3164 			k = i;
3165 			save_screen(vc);
3166 		}
3167 
3168 		old_was_color = vc->vc_can_do_color;
3169 		vc->vc_sw->con_deinit(vc);
3170 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3171 		visual_init(vc, i, 0);
3172 		set_origin(vc);
3173 		update_attr(vc);
3174 
3175 		/* If the console changed between mono <-> color, then
3176 		 * the attributes in the screenbuf will be wrong.  The
3177 		 * following resets all attributes to something sane.
3178 		 */
3179 		if (old_was_color != vc->vc_can_do_color)
3180 			clear_buffer_attributes(vc);
3181 	}
3182 
3183 	pr_info("Console: switching ");
3184 	if (!deflt)
3185 		printk("consoles %d-%d ", first+1, last+1);
3186 	if (j >= 0) {
3187 		struct vc_data *vc = vc_cons[j].d;
3188 
3189 		printk("to %s %s %dx%d\n",
3190 		       vc->vc_can_do_color ? "colour" : "mono",
3191 		       desc, vc->vc_cols, vc->vc_rows);
3192 
3193 		if (k >= 0) {
3194 			vc = vc_cons[k].d;
3195 			update_screen(vc);
3196 		}
3197 	} else
3198 		printk("to %s\n", desc);
3199 
3200 	retval = 0;
3201 err:
3202 	module_put(owner);
3203 	return retval;
3204 };
3205 
3206 
3207 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3208 /* unlocked version of unbind_con_driver() */
3209 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3210 {
3211 	struct module *owner = csw->owner;
3212 	const struct consw *defcsw = NULL;
3213 	struct con_driver *con_driver = NULL, *con_back = NULL;
3214 	int i, retval = -ENODEV;
3215 
3216 	if (!try_module_get(owner))
3217 		return -ENODEV;
3218 
3219 	WARN_CONSOLE_UNLOCKED();
3220 
3221 	/* check if driver is registered and if it is unbindable */
3222 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3223 		con_driver = &registered_con_driver[i];
3224 
3225 		if (con_driver->con == csw &&
3226 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3227 			retval = 0;
3228 			break;
3229 		}
3230 	}
3231 
3232 	if (retval)
3233 		goto err;
3234 
3235 	retval = -ENODEV;
3236 
3237 	/* check if backup driver exists */
3238 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3239 		con_back = &registered_con_driver[i];
3240 
3241 		if (con_back->con && con_back->con != csw) {
3242 			defcsw = con_back->con;
3243 			retval = 0;
3244 			break;
3245 		}
3246 	}
3247 
3248 	if (retval)
3249 		goto err;
3250 
3251 	if (!con_is_bound(csw))
3252 		goto err;
3253 
3254 	first = max(first, con_driver->first);
3255 	last = min(last, con_driver->last);
3256 
3257 	for (i = first; i <= last; i++) {
3258 		if (con_driver_map[i] == csw) {
3259 			module_put(csw->owner);
3260 			con_driver_map[i] = NULL;
3261 		}
3262 	}
3263 
3264 	if (!con_is_bound(defcsw)) {
3265 		const struct consw *defconsw = conswitchp;
3266 
3267 		defcsw->con_startup();
3268 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3269 		/*
3270 		 * vgacon may change the default driver to point
3271 		 * to dummycon, we restore it here...
3272 		 */
3273 		conswitchp = defconsw;
3274 	}
3275 
3276 	if (!con_is_bound(csw))
3277 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3278 
3279 	/* ignore return value, binding should not fail */
3280 	do_bind_con_driver(defcsw, first, last, deflt);
3281 err:
3282 	module_put(owner);
3283 	return retval;
3284 
3285 }
3286 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3287 
3288 static int vt_bind(struct con_driver *con)
3289 {
3290 	const struct consw *defcsw = NULL, *csw = NULL;
3291 	int i, more = 1, first = -1, last = -1, deflt = 0;
3292 
3293  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3294 		goto err;
3295 
3296 	csw = con->con;
3297 
3298 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3299 		struct con_driver *con = &registered_con_driver[i];
3300 
3301 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3302 			defcsw = con->con;
3303 			break;
3304 		}
3305 	}
3306 
3307 	if (!defcsw)
3308 		goto err;
3309 
3310 	while (more) {
3311 		more = 0;
3312 
3313 		for (i = con->first; i <= con->last; i++) {
3314 			if (con_driver_map[i] == defcsw) {
3315 				if (first == -1)
3316 					first = i;
3317 				last = i;
3318 				more = 1;
3319 			} else if (first != -1)
3320 				break;
3321 		}
3322 
3323 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3324 			deflt = 1;
3325 
3326 		if (first != -1)
3327 			do_bind_con_driver(csw, first, last, deflt);
3328 
3329 		first = -1;
3330 		last = -1;
3331 		deflt = 0;
3332 	}
3333 
3334 err:
3335 	return 0;
3336 }
3337 
3338 static int vt_unbind(struct con_driver *con)
3339 {
3340 	const struct consw *csw = NULL;
3341 	int i, more = 1, first = -1, last = -1, deflt = 0;
3342 	int ret;
3343 
3344  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3345 		goto err;
3346 
3347 	csw = con->con;
3348 
3349 	while (more) {
3350 		more = 0;
3351 
3352 		for (i = con->first; i <= con->last; i++) {
3353 			if (con_driver_map[i] == csw) {
3354 				if (first == -1)
3355 					first = i;
3356 				last = i;
3357 				more = 1;
3358 			} else if (first != -1)
3359 				break;
3360 		}
3361 
3362 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3363 			deflt = 1;
3364 
3365 		if (first != -1) {
3366 			ret = do_unbind_con_driver(csw, first, last, deflt);
3367 			if (ret != 0)
3368 				return ret;
3369 		}
3370 
3371 		first = -1;
3372 		last = -1;
3373 		deflt = 0;
3374 	}
3375 
3376 err:
3377 	return 0;
3378 }
3379 #else
3380 static inline int vt_bind(struct con_driver *con)
3381 {
3382 	return 0;
3383 }
3384 static inline int vt_unbind(struct con_driver *con)
3385 {
3386 	return 0;
3387 }
3388 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3389 
3390 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3391 			  const char *buf, size_t count)
3392 {
3393 	struct con_driver *con = dev_get_drvdata(dev);
3394 	int bind = simple_strtoul(buf, NULL, 0);
3395 
3396 	console_lock();
3397 
3398 	if (bind)
3399 		vt_bind(con);
3400 	else
3401 		vt_unbind(con);
3402 
3403 	console_unlock();
3404 
3405 	return count;
3406 }
3407 
3408 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3409 			 char *buf)
3410 {
3411 	struct con_driver *con = dev_get_drvdata(dev);
3412 	int bind = con_is_bound(con->con);
3413 
3414 	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3415 }
3416 
3417 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3418 			 char *buf)
3419 {
3420 	struct con_driver *con = dev_get_drvdata(dev);
3421 
3422 	return snprintf(buf, PAGE_SIZE, "%s %s\n",
3423 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3424 			 con->desc);
3425 
3426 }
3427 
3428 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3429 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3430 
3431 static struct attribute *con_dev_attrs[] = {
3432 	&dev_attr_bind.attr,
3433 	&dev_attr_name.attr,
3434 	NULL
3435 };
3436 
3437 ATTRIBUTE_GROUPS(con_dev);
3438 
3439 static int vtconsole_init_device(struct con_driver *con)
3440 {
3441 	con->flag |= CON_DRIVER_FLAG_ATTR;
3442 	return 0;
3443 }
3444 
3445 static void vtconsole_deinit_device(struct con_driver *con)
3446 {
3447 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3448 }
3449 
3450 /**
3451  * con_is_bound - checks if driver is bound to the console
3452  * @csw: console driver
3453  *
3454  * RETURNS: zero if unbound, nonzero if bound
3455  *
3456  * Drivers can call this and if zero, they should release
3457  * all resources allocated on con_startup()
3458  */
3459 int con_is_bound(const struct consw *csw)
3460 {
3461 	int i, bound = 0;
3462 
3463 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3464 		if (con_driver_map[i] == csw) {
3465 			bound = 1;
3466 			break;
3467 		}
3468 	}
3469 
3470 	return bound;
3471 }
3472 EXPORT_SYMBOL(con_is_bound);
3473 
3474 /**
3475  * con_debug_enter - prepare the console for the kernel debugger
3476  * @sw: console driver
3477  *
3478  * Called when the console is taken over by the kernel debugger, this
3479  * function needs to save the current console state, then put the console
3480  * into a state suitable for the kernel debugger.
3481  *
3482  * RETURNS:
3483  * Zero on success, nonzero if a failure occurred when trying to prepare
3484  * the console for the debugger.
3485  */
3486 int con_debug_enter(struct vc_data *vc)
3487 {
3488 	int ret = 0;
3489 
3490 	saved_fg_console = fg_console;
3491 	saved_last_console = last_console;
3492 	saved_want_console = want_console;
3493 	saved_vc_mode = vc->vc_mode;
3494 	saved_console_blanked = console_blanked;
3495 	vc->vc_mode = KD_TEXT;
3496 	console_blanked = 0;
3497 	if (vc->vc_sw->con_debug_enter)
3498 		ret = vc->vc_sw->con_debug_enter(vc);
3499 #ifdef CONFIG_KGDB_KDB
3500 	/* Set the initial LINES variable if it is not already set */
3501 	if (vc->vc_rows < 999) {
3502 		int linecount;
3503 		char lns[4];
3504 		const char *setargs[3] = {
3505 			"set",
3506 			"LINES",
3507 			lns,
3508 		};
3509 		if (kdbgetintenv(setargs[0], &linecount)) {
3510 			snprintf(lns, 4, "%i", vc->vc_rows);
3511 			kdb_set(2, setargs);
3512 		}
3513 	}
3514 	if (vc->vc_cols < 999) {
3515 		int colcount;
3516 		char cols[4];
3517 		const char *setargs[3] = {
3518 			"set",
3519 			"COLUMNS",
3520 			cols,
3521 		};
3522 		if (kdbgetintenv(setargs[0], &colcount)) {
3523 			snprintf(cols, 4, "%i", vc->vc_cols);
3524 			kdb_set(2, setargs);
3525 		}
3526 	}
3527 #endif /* CONFIG_KGDB_KDB */
3528 	return ret;
3529 }
3530 EXPORT_SYMBOL_GPL(con_debug_enter);
3531 
3532 /**
3533  * con_debug_leave - restore console state
3534  * @sw: console driver
3535  *
3536  * Restore the console state to what it was before the kernel debugger
3537  * was invoked.
3538  *
3539  * RETURNS:
3540  * Zero on success, nonzero if a failure occurred when trying to restore
3541  * the console.
3542  */
3543 int con_debug_leave(void)
3544 {
3545 	struct vc_data *vc;
3546 	int ret = 0;
3547 
3548 	fg_console = saved_fg_console;
3549 	last_console = saved_last_console;
3550 	want_console = saved_want_console;
3551 	console_blanked = saved_console_blanked;
3552 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3553 
3554 	vc = vc_cons[fg_console].d;
3555 	if (vc->vc_sw->con_debug_leave)
3556 		ret = vc->vc_sw->con_debug_leave(vc);
3557 	return ret;
3558 }
3559 EXPORT_SYMBOL_GPL(con_debug_leave);
3560 
3561 static int do_register_con_driver(const struct consw *csw, int first, int last)
3562 {
3563 	struct module *owner = csw->owner;
3564 	struct con_driver *con_driver;
3565 	const char *desc;
3566 	int i, retval;
3567 
3568 	WARN_CONSOLE_UNLOCKED();
3569 
3570 	if (!try_module_get(owner))
3571 		return -ENODEV;
3572 
3573 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3574 		con_driver = &registered_con_driver[i];
3575 
3576 		/* already registered */
3577 		if (con_driver->con == csw) {
3578 			retval = -EBUSY;
3579 			goto err;
3580 		}
3581 	}
3582 
3583 	desc = csw->con_startup();
3584 	if (!desc) {
3585 		retval = -ENODEV;
3586 		goto err;
3587 	}
3588 
3589 	retval = -EINVAL;
3590 
3591 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3592 		con_driver = &registered_con_driver[i];
3593 
3594 		if (con_driver->con == NULL &&
3595 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3596 			con_driver->con = csw;
3597 			con_driver->desc = desc;
3598 			con_driver->node = i;
3599 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
3600 			                   CON_DRIVER_FLAG_INIT;
3601 			con_driver->first = first;
3602 			con_driver->last = last;
3603 			retval = 0;
3604 			break;
3605 		}
3606 	}
3607 
3608 	if (retval)
3609 		goto err;
3610 
3611 	con_driver->dev =
3612 		device_create_with_groups(vtconsole_class, NULL,
3613 					  MKDEV(0, con_driver->node),
3614 					  con_driver, con_dev_groups,
3615 					  "vtcon%i", con_driver->node);
3616 	if (IS_ERR(con_driver->dev)) {
3617 		printk(KERN_WARNING "Unable to create device for %s; "
3618 		       "errno = %ld\n", con_driver->desc,
3619 		       PTR_ERR(con_driver->dev));
3620 		con_driver->dev = NULL;
3621 	} else {
3622 		vtconsole_init_device(con_driver);
3623 	}
3624 
3625 err:
3626 	module_put(owner);
3627 	return retval;
3628 }
3629 
3630 
3631 /**
3632  * do_unregister_con_driver - unregister console driver from console layer
3633  * @csw: console driver
3634  *
3635  * DESCRIPTION: All drivers that registers to the console layer must
3636  * call this function upon exit, or if the console driver is in a state
3637  * where it won't be able to handle console services, such as the
3638  * framebuffer console without loaded framebuffer drivers.
3639  *
3640  * The driver must unbind first prior to unregistration.
3641  */
3642 int do_unregister_con_driver(const struct consw *csw)
3643 {
3644 	int i;
3645 
3646 	/* cannot unregister a bound driver */
3647 	if (con_is_bound(csw))
3648 		return -EBUSY;
3649 
3650 	if (csw == conswitchp)
3651 		return -EINVAL;
3652 
3653 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3654 		struct con_driver *con_driver = &registered_con_driver[i];
3655 
3656 		if (con_driver->con == csw) {
3657 			/*
3658 			 * Defer the removal of the sysfs entries since that
3659 			 * will acquire the kernfs s_active lock and we can't
3660 			 * acquire this lock while holding the console lock:
3661 			 * the unbind sysfs entry imposes already the opposite
3662 			 * order. Reset con already here to prevent any later
3663 			 * lookup to succeed and mark this slot as zombie, so
3664 			 * it won't get reused until we complete the removal
3665 			 * in the deferred work.
3666 			 */
3667 			con_driver->con = NULL;
3668 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
3669 			schedule_work(&con_driver_unregister_work);
3670 
3671 			return 0;
3672 		}
3673 	}
3674 
3675 	return -ENODEV;
3676 }
3677 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
3678 
3679 static void con_driver_unregister_callback(struct work_struct *ignored)
3680 {
3681 	int i;
3682 
3683 	console_lock();
3684 
3685 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3686 		struct con_driver *con_driver = &registered_con_driver[i];
3687 
3688 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
3689 			continue;
3690 
3691 		console_unlock();
3692 
3693 		vtconsole_deinit_device(con_driver);
3694 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
3695 
3696 		console_lock();
3697 
3698 		if (WARN_ON_ONCE(con_driver->con))
3699 			con_driver->con = NULL;
3700 		con_driver->desc = NULL;
3701 		con_driver->dev = NULL;
3702 		con_driver->node = 0;
3703 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
3704 		con_driver->flag = 0;
3705 		con_driver->first = 0;
3706 		con_driver->last = 0;
3707 	}
3708 
3709 	console_unlock();
3710 }
3711 
3712 /*
3713  *	If we support more console drivers, this function is used
3714  *	when a driver wants to take over some existing consoles
3715  *	and become default driver for newly opened ones.
3716  *
3717  *	do_take_over_console is basically a register followed by unbind
3718  */
3719 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
3720 {
3721 	int err;
3722 
3723 	err = do_register_con_driver(csw, first, last);
3724 	/*
3725 	 * If we get an busy error we still want to bind the console driver
3726 	 * and return success, as we may have unbound the console driver
3727 	 * but not unregistered it.
3728 	 */
3729 	if (err == -EBUSY)
3730 		err = 0;
3731 	if (!err)
3732 		do_bind_con_driver(csw, first, last, deflt);
3733 
3734 	return err;
3735 }
3736 EXPORT_SYMBOL_GPL(do_take_over_console);
3737 
3738 
3739 /*
3740  * give_up_console is a wrapper to unregister_con_driver. It will only
3741  * work if driver is fully unbound.
3742  */
3743 void give_up_console(const struct consw *csw)
3744 {
3745 	console_lock();
3746 	do_unregister_con_driver(csw);
3747 	console_unlock();
3748 }
3749 
3750 static int __init vtconsole_class_init(void)
3751 {
3752 	int i;
3753 
3754 	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
3755 	if (IS_ERR(vtconsole_class)) {
3756 		printk(KERN_WARNING "Unable to create vt console class; "
3757 		       "errno = %ld\n", PTR_ERR(vtconsole_class));
3758 		vtconsole_class = NULL;
3759 	}
3760 
3761 	/* Add system drivers to sysfs */
3762 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3763 		struct con_driver *con = &registered_con_driver[i];
3764 
3765 		if (con->con && !con->dev) {
3766 			con->dev =
3767 				device_create_with_groups(vtconsole_class, NULL,
3768 							  MKDEV(0, con->node),
3769 							  con, con_dev_groups,
3770 							  "vtcon%i", con->node);
3771 
3772 			if (IS_ERR(con->dev)) {
3773 				printk(KERN_WARNING "Unable to create "
3774 				       "device for %s; errno = %ld\n",
3775 				       con->desc, PTR_ERR(con->dev));
3776 				con->dev = NULL;
3777 			} else {
3778 				vtconsole_init_device(con);
3779 			}
3780 		}
3781 	}
3782 
3783 	return 0;
3784 }
3785 postcore_initcall(vtconsole_class_init);
3786 
3787 #endif
3788 
3789 /*
3790  *	Screen blanking
3791  */
3792 
3793 static int set_vesa_blanking(char __user *p)
3794 {
3795 	unsigned int mode;
3796 
3797 	if (get_user(mode, p + 1))
3798 		return -EFAULT;
3799 
3800 	vesa_blank_mode = (mode < 4) ? mode : 0;
3801 	return 0;
3802 }
3803 
3804 void do_blank_screen(int entering_gfx)
3805 {
3806 	struct vc_data *vc = vc_cons[fg_console].d;
3807 	int i;
3808 
3809 	WARN_CONSOLE_UNLOCKED();
3810 
3811 	if (console_blanked) {
3812 		if (blank_state == blank_vesa_wait) {
3813 			blank_state = blank_off;
3814 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
3815 		}
3816 		return;
3817 	}
3818 
3819 	/* entering graphics mode? */
3820 	if (entering_gfx) {
3821 		hide_cursor(vc);
3822 		save_screen(vc);
3823 		vc->vc_sw->con_blank(vc, -1, 1);
3824 		console_blanked = fg_console + 1;
3825 		blank_state = blank_off;
3826 		set_origin(vc);
3827 		return;
3828 	}
3829 
3830 	if (blank_state != blank_normal_wait)
3831 		return;
3832 	blank_state = blank_off;
3833 
3834 	/* don't blank graphics */
3835 	if (vc->vc_mode != KD_TEXT) {
3836 		console_blanked = fg_console + 1;
3837 		return;
3838 	}
3839 
3840 	hide_cursor(vc);
3841 	del_timer_sync(&console_timer);
3842 	blank_timer_expired = 0;
3843 
3844 	save_screen(vc);
3845 	/* In case we need to reset origin, blanking hook returns 1 */
3846 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
3847 	console_blanked = fg_console + 1;
3848 	if (i)
3849 		set_origin(vc);
3850 
3851 	if (console_blank_hook && console_blank_hook(1))
3852 		return;
3853 
3854 	if (vesa_off_interval && vesa_blank_mode) {
3855 		blank_state = blank_vesa_wait;
3856 		mod_timer(&console_timer, jiffies + vesa_off_interval);
3857 	}
3858 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
3859 }
3860 EXPORT_SYMBOL(do_blank_screen);
3861 
3862 /*
3863  * Called by timer as well as from vt_console_driver
3864  */
3865 void do_unblank_screen(int leaving_gfx)
3866 {
3867 	struct vc_data *vc;
3868 
3869 	/* This should now always be called from a "sane" (read: can schedule)
3870 	 * context for the sake of the low level drivers, except in the special
3871 	 * case of oops_in_progress
3872 	 */
3873 	if (!oops_in_progress)
3874 		might_sleep();
3875 
3876 	WARN_CONSOLE_UNLOCKED();
3877 
3878 	ignore_poke = 0;
3879 	if (!console_blanked)
3880 		return;
3881 	if (!vc_cons_allocated(fg_console)) {
3882 		/* impossible */
3883 		pr_warn("unblank_screen: tty %d not allocated ??\n",
3884 			fg_console + 1);
3885 		return;
3886 	}
3887 	vc = vc_cons[fg_console].d;
3888 	/* Try to unblank in oops case too */
3889 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
3890 		return; /* but leave console_blanked != 0 */
3891 
3892 	if (blankinterval) {
3893 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3894 		blank_state = blank_normal_wait;
3895 	}
3896 
3897 	console_blanked = 0;
3898 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
3899 		/* Low-level driver cannot restore -> do it ourselves */
3900 		update_screen(vc);
3901 	if (console_blank_hook)
3902 		console_blank_hook(0);
3903 	set_palette(vc);
3904 	set_cursor(vc);
3905 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
3906 }
3907 EXPORT_SYMBOL(do_unblank_screen);
3908 
3909 /*
3910  * This is called by the outside world to cause a forced unblank, mostly for
3911  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
3912  * call it with 1 as an argument and so force a mode restore... that may kill
3913  * X or at least garbage the screen but would also make the Oops visible...
3914  */
3915 void unblank_screen(void)
3916 {
3917 	do_unblank_screen(0);
3918 }
3919 
3920 /*
3921  * We defer the timer blanking to work queue so it can take the console mutex
3922  * (console operations can still happen at irq time, but only from printk which
3923  * has the console mutex. Not perfect yet, but better than no locking
3924  */
3925 static void blank_screen_t(unsigned long dummy)
3926 {
3927 	if (unlikely(!keventd_up())) {
3928 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3929 		return;
3930 	}
3931 	blank_timer_expired = 1;
3932 	schedule_work(&console_work);
3933 }
3934 
3935 void poke_blanked_console(void)
3936 {
3937 	WARN_CONSOLE_UNLOCKED();
3938 
3939 	/* Add this so we quickly catch whoever might call us in a non
3940 	 * safe context. Nowadays, unblank_screen() isn't to be called in
3941 	 * atomic contexts and is allowed to schedule (with the special case
3942 	 * of oops_in_progress, but that isn't of any concern for this
3943 	 * function. --BenH.
3944 	 */
3945 	might_sleep();
3946 
3947 	/* This isn't perfectly race free, but a race here would be mostly harmless,
3948 	 * at worse, we'll do a spurrious blank and it's unlikely
3949 	 */
3950 	del_timer(&console_timer);
3951 	blank_timer_expired = 0;
3952 
3953 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
3954 		return;
3955 	if (console_blanked)
3956 		unblank_screen();
3957 	else if (blankinterval) {
3958 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3959 		blank_state = blank_normal_wait;
3960 	}
3961 }
3962 
3963 /*
3964  *	Palettes
3965  */
3966 
3967 static void set_palette(struct vc_data *vc)
3968 {
3969 	WARN_CONSOLE_UNLOCKED();
3970 
3971 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
3972 		vc->vc_sw->con_set_palette(vc, color_table);
3973 }
3974 
3975 /*
3976  * Load palette into the DAC registers. arg points to a colour
3977  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
3978  */
3979 
3980 int con_set_cmap(unsigned char __user *arg)
3981 {
3982 	int i, j, k;
3983 	unsigned char colormap[3*16];
3984 
3985 	if (copy_from_user(colormap, arg, sizeof(colormap)))
3986 		return -EFAULT;
3987 
3988 	console_lock();
3989 	for (i = k = 0; i < 16; i++) {
3990 		default_red[i] = colormap[k++];
3991 		default_grn[i] = colormap[k++];
3992 		default_blu[i] = colormap[k++];
3993 	}
3994 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3995 		if (!vc_cons_allocated(i))
3996 			continue;
3997 		for (j = k = 0; j < 16; j++) {
3998 			vc_cons[i].d->vc_palette[k++] = default_red[j];
3999 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4000 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4001 		}
4002 		set_palette(vc_cons[i].d);
4003 	}
4004 	console_unlock();
4005 
4006 	return 0;
4007 }
4008 
4009 int con_get_cmap(unsigned char __user *arg)
4010 {
4011 	int i, k;
4012 	unsigned char colormap[3*16];
4013 
4014 	console_lock();
4015 	for (i = k = 0; i < 16; i++) {
4016 		colormap[k++] = default_red[i];
4017 		colormap[k++] = default_grn[i];
4018 		colormap[k++] = default_blu[i];
4019 	}
4020 	console_unlock();
4021 
4022 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4023 		return -EFAULT;
4024 
4025 	return 0;
4026 }
4027 
4028 void reset_palette(struct vc_data *vc)
4029 {
4030 	int j, k;
4031 	for (j=k=0; j<16; j++) {
4032 		vc->vc_palette[k++] = default_red[j];
4033 		vc->vc_palette[k++] = default_grn[j];
4034 		vc->vc_palette[k++] = default_blu[j];
4035 	}
4036 	set_palette(vc);
4037 }
4038 
4039 /*
4040  *  Font switching
4041  *
4042  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4043  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4044  *  depending on width) reserved for each character which is kinda wasty, but
4045  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4046  *  is up to the actual low-level console-driver convert data into its favorite
4047  *  format (maybe we should add a `fontoffset' field to the `display'
4048  *  structure so we won't have to convert the fontdata all the time.
4049  *  /Jes
4050  */
4051 
4052 #define max_font_size 65536
4053 
4054 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4055 {
4056 	struct console_font font;
4057 	int rc = -EINVAL;
4058 	int c;
4059 
4060 	if (op->data) {
4061 		font.data = kmalloc(max_font_size, GFP_KERNEL);
4062 		if (!font.data)
4063 			return -ENOMEM;
4064 	} else
4065 		font.data = NULL;
4066 
4067 	console_lock();
4068 	if (vc->vc_mode != KD_TEXT)
4069 		rc = -EINVAL;
4070 	else if (vc->vc_sw->con_font_get)
4071 		rc = vc->vc_sw->con_font_get(vc, &font);
4072 	else
4073 		rc = -ENOSYS;
4074 	console_unlock();
4075 
4076 	if (rc)
4077 		goto out;
4078 
4079 	c = (font.width+7)/8 * 32 * font.charcount;
4080 
4081 	if (op->data && font.charcount > op->charcount)
4082 		rc = -ENOSPC;
4083 	if (!(op->flags & KD_FONT_FLAG_OLD)) {
4084 		if (font.width > op->width || font.height > op->height)
4085 			rc = -ENOSPC;
4086 	} else {
4087 		if (font.width != 8)
4088 			rc = -EIO;
4089 		else if ((op->height && font.height > op->height) ||
4090 			 font.height > 32)
4091 			rc = -ENOSPC;
4092 	}
4093 	if (rc)
4094 		goto out;
4095 
4096 	op->height = font.height;
4097 	op->width = font.width;
4098 	op->charcount = font.charcount;
4099 
4100 	if (op->data && copy_to_user(op->data, font.data, c))
4101 		rc = -EFAULT;
4102 
4103 out:
4104 	kfree(font.data);
4105 	return rc;
4106 }
4107 
4108 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4109 {
4110 	struct console_font font;
4111 	int rc = -EINVAL;
4112 	int size;
4113 
4114 	if (vc->vc_mode != KD_TEXT)
4115 		return -EINVAL;
4116 	if (!op->data)
4117 		return -EINVAL;
4118 	if (op->charcount > 512)
4119 		return -EINVAL;
4120 	if (!op->height) {		/* Need to guess font height [compat] */
4121 		int h, i;
4122 		u8 __user *charmap = op->data;
4123 		u8 tmp;
4124 
4125 		/* If from KDFONTOP ioctl, don't allow things which can be done in userland,
4126 		   so that we can get rid of this soon */
4127 		if (!(op->flags & KD_FONT_FLAG_OLD))
4128 			return -EINVAL;
4129 		for (h = 32; h > 0; h--)
4130 			for (i = 0; i < op->charcount; i++) {
4131 				if (get_user(tmp, &charmap[32*i+h-1]))
4132 					return -EFAULT;
4133 				if (tmp)
4134 					goto nonzero;
4135 			}
4136 		return -EINVAL;
4137 	nonzero:
4138 		op->height = h;
4139 	}
4140 	if (op->width <= 0 || op->width > 32 || op->height > 32)
4141 		return -EINVAL;
4142 	size = (op->width+7)/8 * 32 * op->charcount;
4143 	if (size > max_font_size)
4144 		return -ENOSPC;
4145 	font.charcount = op->charcount;
4146 	font.height = op->height;
4147 	font.width = op->width;
4148 	font.data = memdup_user(op->data, size);
4149 	if (IS_ERR(font.data))
4150 		return PTR_ERR(font.data);
4151 	console_lock();
4152 	if (vc->vc_mode != KD_TEXT)
4153 		rc = -EINVAL;
4154 	else if (vc->vc_sw->con_font_set)
4155 		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4156 	else
4157 		rc = -ENOSYS;
4158 	console_unlock();
4159 	kfree(font.data);
4160 	return rc;
4161 }
4162 
4163 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4164 {
4165 	struct console_font font = {.width = op->width, .height = op->height};
4166 	char name[MAX_FONT_NAME];
4167 	char *s = name;
4168 	int rc;
4169 
4170 
4171 	if (!op->data)
4172 		s = NULL;
4173 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4174 		return -EFAULT;
4175 	else
4176 		name[MAX_FONT_NAME - 1] = 0;
4177 
4178 	console_lock();
4179 	if (vc->vc_mode != KD_TEXT) {
4180 		console_unlock();
4181 		return -EINVAL;
4182 	}
4183 	if (vc->vc_sw->con_font_default)
4184 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4185 	else
4186 		rc = -ENOSYS;
4187 	console_unlock();
4188 	if (!rc) {
4189 		op->width = font.width;
4190 		op->height = font.height;
4191 	}
4192 	return rc;
4193 }
4194 
4195 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4196 {
4197 	int con = op->height;
4198 	int rc;
4199 
4200 
4201 	console_lock();
4202 	if (vc->vc_mode != KD_TEXT)
4203 		rc = -EINVAL;
4204 	else if (!vc->vc_sw->con_font_copy)
4205 		rc = -ENOSYS;
4206 	else if (con < 0 || !vc_cons_allocated(con))
4207 		rc = -ENOTTY;
4208 	else if (con == vc->vc_num)	/* nothing to do */
4209 		rc = 0;
4210 	else
4211 		rc = vc->vc_sw->con_font_copy(vc, con);
4212 	console_unlock();
4213 	return rc;
4214 }
4215 
4216 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4217 {
4218 	switch (op->op) {
4219 	case KD_FONT_OP_SET:
4220 		return con_font_set(vc, op);
4221 	case KD_FONT_OP_GET:
4222 		return con_font_get(vc, op);
4223 	case KD_FONT_OP_SET_DEFAULT:
4224 		return con_font_default(vc, op);
4225 	case KD_FONT_OP_COPY:
4226 		return con_font_copy(vc, op);
4227 	}
4228 	return -ENOSYS;
4229 }
4230 
4231 /*
4232  *	Interface exported to selection and vcs.
4233  */
4234 
4235 /* used by selection */
4236 u16 screen_glyph(struct vc_data *vc, int offset)
4237 {
4238 	u16 w = scr_readw(screenpos(vc, offset, 1));
4239 	u16 c = w & 0xff;
4240 
4241 	if (w & vc->vc_hi_font_mask)
4242 		c |= 0x100;
4243 	return c;
4244 }
4245 EXPORT_SYMBOL_GPL(screen_glyph);
4246 
4247 /* used by vcs - note the word offset */
4248 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4249 {
4250 	return screenpos(vc, 2 * w_offset, viewed);
4251 }
4252 EXPORT_SYMBOL_GPL(screen_pos);
4253 
4254 void getconsxy(struct vc_data *vc, unsigned char *p)
4255 {
4256 	p[0] = vc->vc_x;
4257 	p[1] = vc->vc_y;
4258 }
4259 
4260 void putconsxy(struct vc_data *vc, unsigned char *p)
4261 {
4262 	hide_cursor(vc);
4263 	gotoxy(vc, p[0], p[1]);
4264 	set_cursor(vc);
4265 }
4266 
4267 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4268 {
4269 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4270 		return softcursor_original;
4271 	return scr_readw(org);
4272 }
4273 
4274 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4275 {
4276 	scr_writew(val, org);
4277 	if ((unsigned long)org == vc->vc_pos) {
4278 		softcursor_original = -1;
4279 		add_softcursor(vc);
4280 	}
4281 }
4282 
4283 void vcs_scr_updated(struct vc_data *vc)
4284 {
4285 	notify_update(vc);
4286 }
4287 
4288 /*
4289  *	Visible symbols for modules
4290  */
4291 
4292 EXPORT_SYMBOL(color_table);
4293 EXPORT_SYMBOL(default_red);
4294 EXPORT_SYMBOL(default_grn);
4295 EXPORT_SYMBOL(default_blu);
4296 EXPORT_SYMBOL(update_region);
4297 EXPORT_SYMBOL(redraw_screen);
4298 EXPORT_SYMBOL(vc_resize);
4299 EXPORT_SYMBOL(fg_console);
4300 EXPORT_SYMBOL(console_blank_hook);
4301 EXPORT_SYMBOL(console_blanked);
4302 EXPORT_SYMBOL(vc_cons);
4303 EXPORT_SYMBOL(global_cursor_default);
4304 #ifndef VT_SINGLE_DRIVER
4305 EXPORT_SYMBOL(give_up_console);
4306 #endif
4307