xref: /linux/drivers/tty/vt/vt.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 1991, 1992  Linus Torvalds
4  */
5 
6 /*
7  * Hopefully this will be a rather complete VT102 implementation.
8  *
9  * Beeping thanks to John T Kohl.
10  *
11  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
12  *   Chars, and VT100 enhancements by Peter MacDonald.
13  *
14  * Copy and paste function by Andrew Haylett,
15  *   some enhancements by Alessandro Rubini.
16  *
17  * Code to check for different video-cards mostly by Galen Hunt,
18  * <g-hunt@ee.utah.edu>
19  *
20  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
21  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
22  *
23  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
24  * Resizing of consoles, aeb, 940926
25  *
26  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
27  * <poe@daimi.aau.dk>
28  *
29  * User-defined bell sound, new setterm control sequences and printk
30  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
31  *
32  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
33  *
34  * Merge with the abstract console driver by Geert Uytterhoeven
35  * <geert@linux-m68k.org>, Jan 1997.
36  *
37  *   Original m68k console driver modifications by
38  *
39  *     - Arno Griffioen <arno@usn.nl>
40  *     - David Carter <carter@cs.bris.ac.uk>
41  *
42  *   The abstract console driver provides a generic interface for a text
43  *   console. It supports VGA text mode, frame buffer based graphical consoles
44  *   and special graphics processors that are only accessible through some
45  *   registers (e.g. a TMS340x0 GSP).
46  *
47  *   The interface to the hardware is specified using a special structure
48  *   (struct consw) which contains function pointers to console operations
49  *   (see <linux/console.h> for more information).
50  *
51  * Support for changeable cursor shape
52  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
53  *
54  * Ported to i386 and con_scrolldelta fixed
55  * by Emmanuel Marty <core@ggi-project.org>, April 1998
56  *
57  * Resurrected character buffers in videoram plus lots of other trickery
58  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
59  *
60  * Removed old-style timers, introduced console_timer, made timer
61  * deletion SMP-safe.  17Jun00, Andrew Morton
62  *
63  * Removed console_lock, enabled interrupts across all console operations
64  * 13 March 2001, Andrew Morton
65  *
66  * Fixed UTF-8 mode so alternate charset modes always work according
67  * to control sequences interpreted in do_con_trol function
68  * preserving backward VT100 semigraphics compatibility,
69  * malformed UTF sequences represented as sequences of replacement glyphs,
70  * original codes or '?' as a last resort if replacement glyph is undefined
71  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
72  */
73 
74 #include <linux/module.h>
75 #include <linux/types.h>
76 #include <linux/sched/signal.h>
77 #include <linux/tty.h>
78 #include <linux/tty_flip.h>
79 #include <linux/kernel.h>
80 #include <linux/string.h>
81 #include <linux/errno.h>
82 #include <linux/kd.h>
83 #include <linux/slab.h>
84 #include <linux/major.h>
85 #include <linux/mm.h>
86 #include <linux/console.h>
87 #include <linux/init.h>
88 #include <linux/mutex.h>
89 #include <linux/vt_kern.h>
90 #include <linux/selection.h>
91 #include <linux/tiocl.h>
92 #include <linux/kbd_kern.h>
93 #include <linux/consolemap.h>
94 #include <linux/timer.h>
95 #include <linux/interrupt.h>
96 #include <linux/workqueue.h>
97 #include <linux/pm.h>
98 #include <linux/font.h>
99 #include <linux/bitops.h>
100 #include <linux/notifier.h>
101 #include <linux/device.h>
102 #include <linux/io.h>
103 #include <linux/uaccess.h>
104 #include <linux/kdb.h>
105 #include <linux/ctype.h>
106 #include <linux/bsearch.h>
107 
108 #define MAX_NR_CON_DRIVER 16
109 
110 #define CON_DRIVER_FLAG_MODULE 1
111 #define CON_DRIVER_FLAG_INIT   2
112 #define CON_DRIVER_FLAG_ATTR   4
113 #define CON_DRIVER_FLAG_ZOMBIE 8
114 
115 struct con_driver {
116 	const struct consw *con;
117 	const char *desc;
118 	struct device *dev;
119 	int node;
120 	int first;
121 	int last;
122 	int flag;
123 };
124 
125 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
126 const struct consw *conswitchp;
127 
128 /* A bitmap for codes <32. A bit of 1 indicates that the code
129  * corresponding to that bit number invokes some special action
130  * (such as cursor movement) and should not be displayed as a
131  * glyph unless the disp_ctrl mode is explicitly enabled.
132  */
133 #define CTRL_ACTION 0x0d00ff81
134 #define CTRL_ALWAYS 0x0800f501	/* Cannot be overridden by disp_ctrl */
135 
136 /*
137  * Here is the default bell parameters: 750HZ, 1/8th of a second
138  */
139 #define DEFAULT_BELL_PITCH	750
140 #define DEFAULT_BELL_DURATION	(HZ/8)
141 #define DEFAULT_CURSOR_BLINK_MS	200
142 
143 struct vc vc_cons [MAX_NR_CONSOLES];
144 
145 #ifndef VT_SINGLE_DRIVER
146 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
147 #endif
148 
149 static int con_open(struct tty_struct *, struct file *);
150 static void vc_init(struct vc_data *vc, unsigned int rows,
151 		    unsigned int cols, int do_clear);
152 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
153 static void save_cur(struct vc_data *vc);
154 static void reset_terminal(struct vc_data *vc, int do_clear);
155 static void con_flush_chars(struct tty_struct *tty);
156 static int set_vesa_blanking(char __user *p);
157 static void set_cursor(struct vc_data *vc);
158 static void hide_cursor(struct vc_data *vc);
159 static void console_callback(struct work_struct *ignored);
160 static void con_driver_unregister_callback(struct work_struct *ignored);
161 static void blank_screen_t(struct timer_list *unused);
162 static void set_palette(struct vc_data *vc);
163 
164 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
165 
166 static int printable;		/* Is console ready for printing? */
167 int default_utf8 = true;
168 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
169 int global_cursor_default = -1;
170 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
171 
172 static int cur_default = CUR_DEFAULT;
173 module_param(cur_default, int, S_IRUGO | S_IWUSR);
174 
175 /*
176  * ignore_poke: don't unblank the screen when things are typed.  This is
177  * mainly for the privacy of braille terminal users.
178  */
179 static int ignore_poke;
180 
181 int do_poke_blanked_console;
182 int console_blanked;
183 
184 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
185 static int vesa_off_interval;
186 static int blankinterval;
187 core_param(consoleblank, blankinterval, int, 0444);
188 
189 static DECLARE_WORK(console_work, console_callback);
190 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
191 
192 /*
193  * fg_console is the current virtual console,
194  * last_console is the last used one,
195  * want_console is the console we want to switch to,
196  * saved_* variants are for save/restore around kernel debugger enter/leave
197  */
198 int fg_console;
199 int last_console;
200 int want_console = -1;
201 static int saved_fg_console;
202 static int saved_last_console;
203 static int saved_want_console;
204 static int saved_vc_mode;
205 static int saved_console_blanked;
206 
207 /*
208  * For each existing display, we have a pointer to console currently visible
209  * on that display, allowing consoles other than fg_console to be refreshed
210  * appropriately. Unless the low-level driver supplies its own display_fg
211  * variable, we use this one for the "master display".
212  */
213 static struct vc_data *master_display_fg;
214 
215 /*
216  * Unfortunately, we need to delay tty echo when we're currently writing to the
217  * console since the code is (and always was) not re-entrant, so we schedule
218  * all flip requests to process context with schedule-task() and run it from
219  * console_callback().
220  */
221 
222 /*
223  * For the same reason, we defer scrollback to the console callback.
224  */
225 static int scrollback_delta;
226 
227 /*
228  * Hook so that the power management routines can (un)blank
229  * the console on our behalf.
230  */
231 int (*console_blank_hook)(int);
232 
233 static DEFINE_TIMER(console_timer, blank_screen_t);
234 static int blank_state;
235 static int blank_timer_expired;
236 enum {
237 	blank_off = 0,
238 	blank_normal_wait,
239 	blank_vesa_wait,
240 };
241 
242 /*
243  * /sys/class/tty/tty0/
244  *
245  * the attribute 'active' contains the name of the current vc
246  * console and it supports poll() to detect vc switches
247  */
248 static struct device *tty0dev;
249 
250 /*
251  * Notifier list for console events.
252  */
253 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
254 
255 int register_vt_notifier(struct notifier_block *nb)
256 {
257 	return atomic_notifier_chain_register(&vt_notifier_list, nb);
258 }
259 EXPORT_SYMBOL_GPL(register_vt_notifier);
260 
261 int unregister_vt_notifier(struct notifier_block *nb)
262 {
263 	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
264 }
265 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
266 
267 static void notify_write(struct vc_data *vc, unsigned int unicode)
268 {
269 	struct vt_notifier_param param = { .vc = vc, .c = unicode };
270 	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
271 }
272 
273 static void notify_update(struct vc_data *vc)
274 {
275 	struct vt_notifier_param param = { .vc = vc };
276 	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
277 }
278 /*
279  *	Low-Level Functions
280  */
281 
282 static inline bool con_is_fg(const struct vc_data *vc)
283 {
284 	return vc->vc_num == fg_console;
285 }
286 
287 static inline bool con_should_update(const struct vc_data *vc)
288 {
289 	return con_is_visible(vc) && !console_blanked;
290 }
291 
292 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
293 {
294 	unsigned short *p;
295 
296 	if (!viewed)
297 		p = (unsigned short *)(vc->vc_origin + offset);
298 	else if (!vc->vc_sw->con_screen_pos)
299 		p = (unsigned short *)(vc->vc_visible_origin + offset);
300 	else
301 		p = vc->vc_sw->con_screen_pos(vc, offset);
302 	return p;
303 }
304 
305 /* Called  from the keyboard irq path.. */
306 static inline void scrolldelta(int lines)
307 {
308 	/* FIXME */
309 	/* scrolldelta needs some kind of consistency lock, but the BKL was
310 	   and still is not protecting versus the scheduled back end */
311 	scrollback_delta += lines;
312 	schedule_console_callback();
313 }
314 
315 void schedule_console_callback(void)
316 {
317 	schedule_work(&console_work);
318 }
319 
320 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
321 		enum con_scroll dir, unsigned int nr)
322 {
323 	u16 *clear, *d, *s;
324 
325 	if (t + nr >= b)
326 		nr = b - t - 1;
327 	if (b > vc->vc_rows || t >= b || nr < 1)
328 		return;
329 	if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
330 		return;
331 
332 	s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
333 	d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
334 
335 	if (dir == SM_UP) {
336 		clear = s + (b - t - nr) * vc->vc_cols;
337 		swap(s, d);
338 	}
339 	scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
340 	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
341 }
342 
343 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
344 {
345 	unsigned int xx, yy, offset;
346 	u16 *p;
347 
348 	p = (u16 *) start;
349 	if (!vc->vc_sw->con_getxy) {
350 		offset = (start - vc->vc_origin) / 2;
351 		xx = offset % vc->vc_cols;
352 		yy = offset / vc->vc_cols;
353 	} else {
354 		int nxx, nyy;
355 		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
356 		xx = nxx; yy = nyy;
357 	}
358 	for(;;) {
359 		u16 attrib = scr_readw(p) & 0xff00;
360 		int startx = xx;
361 		u16 *q = p;
362 		while (xx < vc->vc_cols && count) {
363 			if (attrib != (scr_readw(p) & 0xff00)) {
364 				if (p > q)
365 					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
366 				startx = xx;
367 				q = p;
368 				attrib = scr_readw(p) & 0xff00;
369 			}
370 			p++;
371 			xx++;
372 			count--;
373 		}
374 		if (p > q)
375 			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
376 		if (!count)
377 			break;
378 		xx = 0;
379 		yy++;
380 		if (vc->vc_sw->con_getxy) {
381 			p = (u16 *)start;
382 			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
383 		}
384 	}
385 }
386 
387 void update_region(struct vc_data *vc, unsigned long start, int count)
388 {
389 	WARN_CONSOLE_UNLOCKED();
390 
391 	if (con_should_update(vc)) {
392 		hide_cursor(vc);
393 		do_update_region(vc, start, count);
394 		set_cursor(vc);
395 	}
396 }
397 
398 /* Structure of attributes is hardware-dependent */
399 
400 static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
401     u8 _underline, u8 _reverse, u8 _italic)
402 {
403 	if (vc->vc_sw->con_build_attr)
404 		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
405 		       _blink, _underline, _reverse, _italic);
406 
407 /*
408  * ++roman: I completely changed the attribute format for monochrome
409  * mode (!can_do_color). The formerly used MDA (monochrome display
410  * adapter) format didn't allow the combination of certain effects.
411  * Now the attribute is just a bit vector:
412  *  Bit 0..1: intensity (0..2)
413  *  Bit 2   : underline
414  *  Bit 3   : reverse
415  *  Bit 7   : blink
416  */
417 	{
418 	u8 a = _color;
419 	if (!vc->vc_can_do_color)
420 		return _intensity |
421 		       (_italic ? 2 : 0) |
422 		       (_underline ? 4 : 0) |
423 		       (_reverse ? 8 : 0) |
424 		       (_blink ? 0x80 : 0);
425 	if (_italic)
426 		a = (a & 0xF0) | vc->vc_itcolor;
427 	else if (_underline)
428 		a = (a & 0xf0) | vc->vc_ulcolor;
429 	else if (_intensity == 0)
430 		a = (a & 0xf0) | vc->vc_halfcolor;
431 	if (_reverse)
432 		a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
433 	if (_blink)
434 		a ^= 0x80;
435 	if (_intensity == 2)
436 		a ^= 0x08;
437 	if (vc->vc_hi_font_mask == 0x100)
438 		a <<= 1;
439 	return a;
440 	}
441 }
442 
443 static void update_attr(struct vc_data *vc)
444 {
445 	vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
446 	              vc->vc_blink, vc->vc_underline,
447 	              vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
448 	vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
449 }
450 
451 /* Note: inverting the screen twice should revert to the original state */
452 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
453 {
454 	unsigned short *p;
455 
456 	WARN_CONSOLE_UNLOCKED();
457 
458 	count /= 2;
459 	p = screenpos(vc, offset, viewed);
460 	if (vc->vc_sw->con_invert_region) {
461 		vc->vc_sw->con_invert_region(vc, p, count);
462 	} else {
463 		u16 *q = p;
464 		int cnt = count;
465 		u16 a;
466 
467 		if (!vc->vc_can_do_color) {
468 			while (cnt--) {
469 			    a = scr_readw(q);
470 			    a ^= 0x0800;
471 			    scr_writew(a, q);
472 			    q++;
473 			}
474 		} else if (vc->vc_hi_font_mask == 0x100) {
475 			while (cnt--) {
476 				a = scr_readw(q);
477 				a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
478 				scr_writew(a, q);
479 				q++;
480 			}
481 		} else {
482 			while (cnt--) {
483 				a = scr_readw(q);
484 				a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
485 				scr_writew(a, q);
486 				q++;
487 			}
488 		}
489 	}
490 
491 	if (con_should_update(vc))
492 		do_update_region(vc, (unsigned long) p, count);
493 	notify_update(vc);
494 }
495 
496 /* used by selection: complement pointer position */
497 void complement_pos(struct vc_data *vc, int offset)
498 {
499 	static int old_offset = -1;
500 	static unsigned short old;
501 	static unsigned short oldx, oldy;
502 
503 	WARN_CONSOLE_UNLOCKED();
504 
505 	if (old_offset != -1 && old_offset >= 0 &&
506 	    old_offset < vc->vc_screenbuf_size) {
507 		scr_writew(old, screenpos(vc, old_offset, 1));
508 		if (con_should_update(vc))
509 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
510 		notify_update(vc);
511 	}
512 
513 	old_offset = offset;
514 
515 	if (offset != -1 && offset >= 0 &&
516 	    offset < vc->vc_screenbuf_size) {
517 		unsigned short new;
518 		unsigned short *p;
519 		p = screenpos(vc, offset, 1);
520 		old = scr_readw(p);
521 		new = old ^ vc->vc_complement_mask;
522 		scr_writew(new, p);
523 		if (con_should_update(vc)) {
524 			oldx = (offset >> 1) % vc->vc_cols;
525 			oldy = (offset >> 1) / vc->vc_cols;
526 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
527 		}
528 		notify_update(vc);
529 	}
530 }
531 
532 static void insert_char(struct vc_data *vc, unsigned int nr)
533 {
534 	unsigned short *p = (unsigned short *) vc->vc_pos;
535 
536 	scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
537 	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
538 	vc->vc_need_wrap = 0;
539 	if (con_should_update(vc))
540 		do_update_region(vc, (unsigned long) p,
541 			vc->vc_cols - vc->vc_x);
542 }
543 
544 static void delete_char(struct vc_data *vc, unsigned int nr)
545 {
546 	unsigned short *p = (unsigned short *) vc->vc_pos;
547 
548 	scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
549 	scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
550 			nr * 2);
551 	vc->vc_need_wrap = 0;
552 	if (con_should_update(vc))
553 		do_update_region(vc, (unsigned long) p,
554 			vc->vc_cols - vc->vc_x);
555 }
556 
557 static int softcursor_original = -1;
558 
559 static void add_softcursor(struct vc_data *vc)
560 {
561 	int i = scr_readw((u16 *) vc->vc_pos);
562 	u32 type = vc->vc_cursor_type;
563 
564 	if (! (type & 0x10)) return;
565 	if (softcursor_original != -1) return;
566 	softcursor_original = i;
567 	i |= ((type >> 8) & 0xff00 );
568 	i ^= ((type) & 0xff00 );
569 	if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
570 	if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
571 	scr_writew(i, (u16 *) vc->vc_pos);
572 	if (con_should_update(vc))
573 		vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
574 }
575 
576 static void hide_softcursor(struct vc_data *vc)
577 {
578 	if (softcursor_original != -1) {
579 		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
580 		if (con_should_update(vc))
581 			vc->vc_sw->con_putc(vc, softcursor_original,
582 					vc->vc_y, vc->vc_x);
583 		softcursor_original = -1;
584 	}
585 }
586 
587 static void hide_cursor(struct vc_data *vc)
588 {
589 	if (vc == sel_cons)
590 		clear_selection();
591 	vc->vc_sw->con_cursor(vc, CM_ERASE);
592 	hide_softcursor(vc);
593 }
594 
595 static void set_cursor(struct vc_data *vc)
596 {
597 	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
598 		return;
599 	if (vc->vc_deccm) {
600 		if (vc == sel_cons)
601 			clear_selection();
602 		add_softcursor(vc);
603 		if ((vc->vc_cursor_type & 0x0f) != 1)
604 			vc->vc_sw->con_cursor(vc, CM_DRAW);
605 	} else
606 		hide_cursor(vc);
607 }
608 
609 static void set_origin(struct vc_data *vc)
610 {
611 	WARN_CONSOLE_UNLOCKED();
612 
613 	if (!con_is_visible(vc) ||
614 	    !vc->vc_sw->con_set_origin ||
615 	    !vc->vc_sw->con_set_origin(vc))
616 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
617 	vc->vc_visible_origin = vc->vc_origin;
618 	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
619 	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
620 }
621 
622 static void save_screen(struct vc_data *vc)
623 {
624 	WARN_CONSOLE_UNLOCKED();
625 
626 	if (vc->vc_sw->con_save_screen)
627 		vc->vc_sw->con_save_screen(vc);
628 }
629 
630 static void flush_scrollback(struct vc_data *vc)
631 {
632 	WARN_CONSOLE_UNLOCKED();
633 
634 	if (vc->vc_sw->con_flush_scrollback)
635 		vc->vc_sw->con_flush_scrollback(vc);
636 }
637 
638 /*
639  *	Redrawing of screen
640  */
641 
642 void clear_buffer_attributes(struct vc_data *vc)
643 {
644 	unsigned short *p = (unsigned short *)vc->vc_origin;
645 	int count = vc->vc_screenbuf_size / 2;
646 	int mask = vc->vc_hi_font_mask | 0xff;
647 
648 	for (; count > 0; count--, p++) {
649 		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
650 	}
651 }
652 
653 void redraw_screen(struct vc_data *vc, int is_switch)
654 {
655 	int redraw = 0;
656 
657 	WARN_CONSOLE_UNLOCKED();
658 
659 	if (!vc) {
660 		/* strange ... */
661 		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
662 		return;
663 	}
664 
665 	if (is_switch) {
666 		struct vc_data *old_vc = vc_cons[fg_console].d;
667 		if (old_vc == vc)
668 			return;
669 		if (!con_is_visible(vc))
670 			redraw = 1;
671 		*vc->vc_display_fg = vc;
672 		fg_console = vc->vc_num;
673 		hide_cursor(old_vc);
674 		if (!con_is_visible(old_vc)) {
675 			save_screen(old_vc);
676 			set_origin(old_vc);
677 		}
678 		if (tty0dev)
679 			sysfs_notify(&tty0dev->kobj, NULL, "active");
680 	} else {
681 		hide_cursor(vc);
682 		redraw = 1;
683 	}
684 
685 	if (redraw) {
686 		int update;
687 		int old_was_color = vc->vc_can_do_color;
688 
689 		set_origin(vc);
690 		update = vc->vc_sw->con_switch(vc);
691 		set_palette(vc);
692 		/*
693 		 * If console changed from mono<->color, the best we can do
694 		 * is to clear the buffer attributes. As it currently stands,
695 		 * rebuilding new attributes from the old buffer is not doable
696 		 * without overly complex code.
697 		 */
698 		if (old_was_color != vc->vc_can_do_color) {
699 			update_attr(vc);
700 			clear_buffer_attributes(vc);
701 		}
702 
703 		/* Forcibly update if we're panicing */
704 		if ((update && vc->vc_mode != KD_GRAPHICS) ||
705 		    vt_force_oops_output(vc))
706 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
707 	}
708 	set_cursor(vc);
709 	if (is_switch) {
710 		set_leds();
711 		compute_shiftstate();
712 		notify_update(vc);
713 	}
714 }
715 
716 /*
717  *	Allocation, freeing and resizing of VTs.
718  */
719 
720 int vc_cons_allocated(unsigned int i)
721 {
722 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
723 }
724 
725 static void visual_init(struct vc_data *vc, int num, int init)
726 {
727 	/* ++Geert: vc->vc_sw->con_init determines console size */
728 	if (vc->vc_sw)
729 		module_put(vc->vc_sw->owner);
730 	vc->vc_sw = conswitchp;
731 #ifndef VT_SINGLE_DRIVER
732 	if (con_driver_map[num])
733 		vc->vc_sw = con_driver_map[num];
734 #endif
735 	__module_get(vc->vc_sw->owner);
736 	vc->vc_num = num;
737 	vc->vc_display_fg = &master_display_fg;
738 	if (vc->vc_uni_pagedir_loc)
739 		con_free_unimap(vc);
740 	vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
741 	vc->vc_uni_pagedir = NULL;
742 	vc->vc_hi_font_mask = 0;
743 	vc->vc_complement_mask = 0;
744 	vc->vc_can_do_color = 0;
745 	vc->vc_panic_force_write = false;
746 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
747 	vc->vc_sw->con_init(vc, init);
748 	if (!vc->vc_complement_mask)
749 		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
750 	vc->vc_s_complement_mask = vc->vc_complement_mask;
751 	vc->vc_size_row = vc->vc_cols << 1;
752 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
753 }
754 
755 int vc_allocate(unsigned int currcons)	/* return 0 on success */
756 {
757 	struct vt_notifier_param param;
758 	struct vc_data *vc;
759 
760 	WARN_CONSOLE_UNLOCKED();
761 
762 	if (currcons >= MAX_NR_CONSOLES)
763 		return -ENXIO;
764 
765 	if (vc_cons[currcons].d)
766 		return 0;
767 
768 	/* due to the granularity of kmalloc, we waste some memory here */
769 	/* the alloc is done in two steps, to optimize the common situation
770 	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
771 	/* although the numbers above are not valid since long ago, the
772 	   point is still up-to-date and the comment still has its value
773 	   even if only as a historical artifact.  --mj, July 1998 */
774 	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
775 	if (!vc)
776 		return -ENOMEM;
777 
778 	vc_cons[currcons].d = vc;
779 	tty_port_init(&vc->port);
780 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
781 
782 	visual_init(vc, currcons, 1);
783 
784 	if (!*vc->vc_uni_pagedir_loc)
785 		con_set_default_unimap(vc);
786 
787 	vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
788 	if (!vc->vc_screenbuf)
789 		goto err_free;
790 
791 	/* If no drivers have overridden us and the user didn't pass a
792 	   boot option, default to displaying the cursor */
793 	if (global_cursor_default == -1)
794 		global_cursor_default = 1;
795 
796 	vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
797 	vcs_make_sysfs(currcons);
798 	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
799 
800 	return 0;
801 err_free:
802 	kfree(vc);
803 	vc_cons[currcons].d = NULL;
804 	return -ENOMEM;
805 }
806 
807 static inline int resize_screen(struct vc_data *vc, int width, int height,
808 				int user)
809 {
810 	/* Resizes the resolution of the display adapater */
811 	int err = 0;
812 
813 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
814 		err = vc->vc_sw->con_resize(vc, width, height, user);
815 
816 	return err;
817 }
818 
819 /*
820  * Change # of rows and columns (0 means unchanged/the size of fg_console)
821  * [this is to be used together with some user program
822  * like resize that changes the hardware videomode]
823  */
824 #define VC_RESIZE_MAXCOL (32767)
825 #define VC_RESIZE_MAXROW (32767)
826 
827 /**
828  *	vc_do_resize	-	resizing method for the tty
829  *	@tty: tty being resized
830  *	@real_tty: real tty (different to tty if a pty/tty pair)
831  *	@vc: virtual console private data
832  *	@cols: columns
833  *	@lines: lines
834  *
835  *	Resize a virtual console, clipping according to the actual constraints.
836  *	If the caller passes a tty structure then update the termios winsize
837  *	information and perform any necessary signal handling.
838  *
839  *	Caller must hold the console semaphore. Takes the termios rwsem and
840  *	ctrl_lock of the tty IFF a tty is passed.
841  */
842 
843 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
844 				unsigned int cols, unsigned int lines)
845 {
846 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
847 	unsigned long end;
848 	unsigned int old_rows, old_row_size;
849 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
850 	unsigned int user;
851 	unsigned short *newscreen;
852 
853 	WARN_CONSOLE_UNLOCKED();
854 
855 	if (!vc)
856 		return -ENXIO;
857 
858 	user = vc->vc_resize_user;
859 	vc->vc_resize_user = 0;
860 
861 	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
862 		return -EINVAL;
863 
864 	new_cols = (cols ? cols : vc->vc_cols);
865 	new_rows = (lines ? lines : vc->vc_rows);
866 	new_row_size = new_cols << 1;
867 	new_screen_size = new_row_size * new_rows;
868 
869 	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
870 		return 0;
871 
872 	if (new_screen_size > (4 << 20))
873 		return -EINVAL;
874 	newscreen = kmalloc(new_screen_size, GFP_USER);
875 	if (!newscreen)
876 		return -ENOMEM;
877 
878 	if (vc == sel_cons)
879 		clear_selection();
880 
881 	old_rows = vc->vc_rows;
882 	old_row_size = vc->vc_size_row;
883 
884 	err = resize_screen(vc, new_cols, new_rows, user);
885 	if (err) {
886 		kfree(newscreen);
887 		return err;
888 	}
889 
890 	vc->vc_rows = new_rows;
891 	vc->vc_cols = new_cols;
892 	vc->vc_size_row = new_row_size;
893 	vc->vc_screenbuf_size = new_screen_size;
894 
895 	rlth = min(old_row_size, new_row_size);
896 	rrem = new_row_size - rlth;
897 	old_origin = vc->vc_origin;
898 	new_origin = (long) newscreen;
899 	new_scr_end = new_origin + new_screen_size;
900 
901 	if (vc->vc_y > new_rows) {
902 		if (old_rows - vc->vc_y < new_rows) {
903 			/*
904 			 * Cursor near the bottom, copy contents from the
905 			 * bottom of buffer
906 			 */
907 			old_origin += (old_rows - new_rows) * old_row_size;
908 		} else {
909 			/*
910 			 * Cursor is in no man's land, copy 1/2 screenful
911 			 * from the top and bottom of cursor position
912 			 */
913 			old_origin += (vc->vc_y - new_rows/2) * old_row_size;
914 		}
915 	}
916 
917 	end = old_origin + old_row_size * min(old_rows, new_rows);
918 
919 	update_attr(vc);
920 
921 	while (old_origin < end) {
922 		scr_memcpyw((unsigned short *) new_origin,
923 			    (unsigned short *) old_origin, rlth);
924 		if (rrem)
925 			scr_memsetw((void *)(new_origin + rlth),
926 				    vc->vc_video_erase_char, rrem);
927 		old_origin += old_row_size;
928 		new_origin += new_row_size;
929 	}
930 	if (new_scr_end > new_origin)
931 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
932 			    new_scr_end - new_origin);
933 	kfree(vc->vc_screenbuf);
934 	vc->vc_screenbuf = newscreen;
935 	vc->vc_screenbuf_size = new_screen_size;
936 	set_origin(vc);
937 
938 	/* do part of a reset_terminal() */
939 	vc->vc_top = 0;
940 	vc->vc_bottom = vc->vc_rows;
941 	gotoxy(vc, vc->vc_x, vc->vc_y);
942 	save_cur(vc);
943 
944 	if (tty) {
945 		/* Rewrite the requested winsize data with the actual
946 		   resulting sizes */
947 		struct winsize ws;
948 		memset(&ws, 0, sizeof(ws));
949 		ws.ws_row = vc->vc_rows;
950 		ws.ws_col = vc->vc_cols;
951 		ws.ws_ypixel = vc->vc_scan_lines;
952 		tty_do_resize(tty, &ws);
953 	}
954 
955 	if (con_is_visible(vc))
956 		update_screen(vc);
957 	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
958 	return err;
959 }
960 
961 /**
962  *	vc_resize		-	resize a VT
963  *	@vc: virtual console
964  *	@cols: columns
965  *	@rows: rows
966  *
967  *	Resize a virtual console as seen from the console end of things. We
968  *	use the common vc_do_resize methods to update the structures. The
969  *	caller must hold the console sem to protect console internals and
970  *	vc->port.tty
971  */
972 
973 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
974 {
975 	return vc_do_resize(vc->port.tty, vc, cols, rows);
976 }
977 
978 /**
979  *	vt_resize		-	resize a VT
980  *	@tty: tty to resize
981  *	@ws: winsize attributes
982  *
983  *	Resize a virtual terminal. This is called by the tty layer as we
984  *	register our own handler for resizing. The mutual helper does all
985  *	the actual work.
986  *
987  *	Takes the console sem and the called methods then take the tty
988  *	termios_rwsem and the tty ctrl_lock in that order.
989  */
990 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
991 {
992 	struct vc_data *vc = tty->driver_data;
993 	int ret;
994 
995 	console_lock();
996 	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
997 	console_unlock();
998 	return ret;
999 }
1000 
1001 struct vc_data *vc_deallocate(unsigned int currcons)
1002 {
1003 	struct vc_data *vc = NULL;
1004 
1005 	WARN_CONSOLE_UNLOCKED();
1006 
1007 	if (vc_cons_allocated(currcons)) {
1008 		struct vt_notifier_param param;
1009 
1010 		param.vc = vc = vc_cons[currcons].d;
1011 		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1012 		vcs_remove_sysfs(currcons);
1013 		vc->vc_sw->con_deinit(vc);
1014 		put_pid(vc->vt_pid);
1015 		module_put(vc->vc_sw->owner);
1016 		kfree(vc->vc_screenbuf);
1017 		vc_cons[currcons].d = NULL;
1018 	}
1019 	return vc;
1020 }
1021 
1022 /*
1023  *	VT102 emulator
1024  */
1025 
1026 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1027 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1028 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1029 
1030 #define decarm		VC_REPEAT
1031 #define decckm		VC_CKMODE
1032 #define kbdapplic	VC_APPLIC
1033 #define lnm		VC_CRLF
1034 
1035 /*
1036  * this is what the terminal answers to a ESC-Z or csi0c query.
1037  */
1038 #define VT100ID "\033[?1;2c"
1039 #define VT102ID "\033[?6c"
1040 
1041 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1042 				       8,12,10,14, 9,13,11,15 };
1043 
1044 /* the default colour table, for VGA+ colour systems */
1045 unsigned char default_red[] = {
1046 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1047 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1048 };
1049 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1050 
1051 unsigned char default_grn[] = {
1052 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1053 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1054 };
1055 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1056 
1057 unsigned char default_blu[] = {
1058 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1059 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1060 };
1061 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1062 
1063 /*
1064  * gotoxy() must verify all boundaries, because the arguments
1065  * might also be negative. If the given position is out of
1066  * bounds, the cursor is placed at the nearest margin.
1067  */
1068 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1069 {
1070 	int min_y, max_y;
1071 
1072 	if (new_x < 0)
1073 		vc->vc_x = 0;
1074 	else {
1075 		if (new_x >= vc->vc_cols)
1076 			vc->vc_x = vc->vc_cols - 1;
1077 		else
1078 			vc->vc_x = new_x;
1079 	}
1080 
1081  	if (vc->vc_decom) {
1082 		min_y = vc->vc_top;
1083 		max_y = vc->vc_bottom;
1084 	} else {
1085 		min_y = 0;
1086 		max_y = vc->vc_rows;
1087 	}
1088 	if (new_y < min_y)
1089 		vc->vc_y = min_y;
1090 	else if (new_y >= max_y)
1091 		vc->vc_y = max_y - 1;
1092 	else
1093 		vc->vc_y = new_y;
1094 	vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
1095 	vc->vc_need_wrap = 0;
1096 }
1097 
1098 /* for absolute user moves, when decom is set */
1099 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1100 {
1101 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1102 }
1103 
1104 void scrollback(struct vc_data *vc)
1105 {
1106 	scrolldelta(-(vc->vc_rows / 2));
1107 }
1108 
1109 void scrollfront(struct vc_data *vc, int lines)
1110 {
1111 	if (!lines)
1112 		lines = vc->vc_rows / 2;
1113 	scrolldelta(lines);
1114 }
1115 
1116 static void lf(struct vc_data *vc)
1117 {
1118     	/* don't scroll if above bottom of scrolling region, or
1119 	 * if below scrolling region
1120 	 */
1121     	if (vc->vc_y + 1 == vc->vc_bottom)
1122 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1123 	else if (vc->vc_y < vc->vc_rows - 1) {
1124 	    	vc->vc_y++;
1125 		vc->vc_pos += vc->vc_size_row;
1126 	}
1127 	vc->vc_need_wrap = 0;
1128 	notify_write(vc, '\n');
1129 }
1130 
1131 static void ri(struct vc_data *vc)
1132 {
1133     	/* don't scroll if below top of scrolling region, or
1134 	 * if above scrolling region
1135 	 */
1136 	if (vc->vc_y == vc->vc_top)
1137 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1138 	else if (vc->vc_y > 0) {
1139 		vc->vc_y--;
1140 		vc->vc_pos -= vc->vc_size_row;
1141 	}
1142 	vc->vc_need_wrap = 0;
1143 }
1144 
1145 static inline void cr(struct vc_data *vc)
1146 {
1147 	vc->vc_pos -= vc->vc_x << 1;
1148 	vc->vc_need_wrap = vc->vc_x = 0;
1149 	notify_write(vc, '\r');
1150 }
1151 
1152 static inline void bs(struct vc_data *vc)
1153 {
1154 	if (vc->vc_x) {
1155 		vc->vc_pos -= 2;
1156 		vc->vc_x--;
1157 		vc->vc_need_wrap = 0;
1158 		notify_write(vc, '\b');
1159 	}
1160 }
1161 
1162 static inline void del(struct vc_data *vc)
1163 {
1164 	/* ignored */
1165 }
1166 
1167 static void csi_J(struct vc_data *vc, int vpar)
1168 {
1169 	unsigned int count;
1170 	unsigned short * start;
1171 
1172 	switch (vpar) {
1173 		case 0:	/* erase from cursor to end of display */
1174 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1175 			start = (unsigned short *)vc->vc_pos;
1176 			break;
1177 		case 1:	/* erase from start to cursor */
1178 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1179 			start = (unsigned short *)vc->vc_origin;
1180 			break;
1181 		case 3: /* erase scroll-back buffer (and whole display) */
1182 			scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
1183 				    vc->vc_screenbuf_size);
1184 			flush_scrollback(vc);
1185 			set_origin(vc);
1186 			if (con_is_visible(vc))
1187 				update_screen(vc);
1188 			/* fall through */
1189 		case 2: /* erase whole display */
1190 			count = vc->vc_cols * vc->vc_rows;
1191 			start = (unsigned short *)vc->vc_origin;
1192 			break;
1193 		default:
1194 			return;
1195 	}
1196 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1197 	if (con_should_update(vc))
1198 		do_update_region(vc, (unsigned long) start, count);
1199 	vc->vc_need_wrap = 0;
1200 }
1201 
1202 static void csi_K(struct vc_data *vc, int vpar)
1203 {
1204 	unsigned int count;
1205 	unsigned short * start;
1206 
1207 	switch (vpar) {
1208 		case 0:	/* erase from cursor to end of line */
1209 			count = vc->vc_cols - vc->vc_x;
1210 			start = (unsigned short *)vc->vc_pos;
1211 			break;
1212 		case 1:	/* erase from start of line to cursor */
1213 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1214 			count = vc->vc_x + 1;
1215 			break;
1216 		case 2: /* erase whole line */
1217 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1218 			count = vc->vc_cols;
1219 			break;
1220 		default:
1221 			return;
1222 	}
1223 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1224 	vc->vc_need_wrap = 0;
1225 	if (con_should_update(vc))
1226 		do_update_region(vc, (unsigned long) start, count);
1227 }
1228 
1229 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1230 {					  /* not vt100? */
1231 	int count;
1232 
1233 	if (!vpar)
1234 		vpar++;
1235 	count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
1236 
1237 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1238 	if (con_should_update(vc))
1239 		vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
1240 	vc->vc_need_wrap = 0;
1241 }
1242 
1243 static void default_attr(struct vc_data *vc)
1244 {
1245 	vc->vc_intensity = 1;
1246 	vc->vc_italic = 0;
1247 	vc->vc_underline = 0;
1248 	vc->vc_reverse = 0;
1249 	vc->vc_blink = 0;
1250 	vc->vc_color = vc->vc_def_color;
1251 }
1252 
1253 struct rgb { u8 r; u8 g; u8 b; };
1254 
1255 static void rgb_from_256(int i, struct rgb *c)
1256 {
1257 	if (i < 8) {            /* Standard colours. */
1258 		c->r = i&1 ? 0xaa : 0x00;
1259 		c->g = i&2 ? 0xaa : 0x00;
1260 		c->b = i&4 ? 0xaa : 0x00;
1261 	} else if (i < 16) {
1262 		c->r = i&1 ? 0xff : 0x55;
1263 		c->g = i&2 ? 0xff : 0x55;
1264 		c->b = i&4 ? 0xff : 0x55;
1265 	} else if (i < 232) {   /* 6x6x6 colour cube. */
1266 		c->r = (i - 16) / 36 * 85 / 2;
1267 		c->g = (i - 16) / 6 % 6 * 85 / 2;
1268 		c->b = (i - 16) % 6 * 85 / 2;
1269 	} else                  /* Grayscale ramp. */
1270 		c->r = c->g = c->b = i * 10 - 2312;
1271 }
1272 
1273 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1274 {
1275 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1276 
1277 	if (c->r > max / 2)
1278 		hue |= 4;
1279 	if (c->g > max / 2)
1280 		hue |= 2;
1281 	if (c->b > max / 2)
1282 		hue |= 1;
1283 
1284 	if (hue == 7 && max <= 0x55) {
1285 		hue = 0;
1286 		vc->vc_intensity = 2;
1287 	} else if (max > 0xaa)
1288 		vc->vc_intensity = 2;
1289 	else
1290 		vc->vc_intensity = 1;
1291 
1292 	vc->vc_color = (vc->vc_color & 0xf0) | hue;
1293 }
1294 
1295 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1296 {
1297 	/* For backgrounds, err on the dark side. */
1298 	vc->vc_color = (vc->vc_color & 0x0f)
1299 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1300 }
1301 
1302 /*
1303  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1304  * and thus need to be detected and ignored by hand. Strictly speaking, that
1305  * standard also wants : rather than ; as separators, contrary to ECMA-48, but
1306  * no one produces such codes and almost no one accepts them.
1307  *
1308  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1309  * supporting them.
1310  */
1311 static int vc_t416_color(struct vc_data *vc, int i,
1312 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1313 {
1314 	struct rgb c;
1315 
1316 	i++;
1317 	if (i > vc->vc_npar)
1318 		return i;
1319 
1320 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1321 		/* 256 colours */
1322 		i++;
1323 		rgb_from_256(vc->vc_par[i], &c);
1324 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1325 		/* 24 bit */
1326 		c.r = vc->vc_par[i + 1];
1327 		c.g = vc->vc_par[i + 2];
1328 		c.b = vc->vc_par[i + 3];
1329 		i += 3;
1330 	} else
1331 		return i;
1332 
1333 	set_color(vc, &c);
1334 
1335 	return i;
1336 }
1337 
1338 /* console_lock is held */
1339 static void csi_m(struct vc_data *vc)
1340 {
1341 	int i;
1342 
1343 	for (i = 0; i <= vc->vc_npar; i++)
1344 		switch (vc->vc_par[i]) {
1345 		case 0:	/* all attributes off */
1346 			default_attr(vc);
1347 			break;
1348 		case 1:
1349 			vc->vc_intensity = 2;
1350 			break;
1351 		case 2:
1352 			vc->vc_intensity = 0;
1353 			break;
1354 		case 3:
1355 			vc->vc_italic = 1;
1356 			break;
1357 		case 4:
1358 			vc->vc_underline = 1;
1359 			break;
1360 		case 5:
1361 			vc->vc_blink = 1;
1362 			break;
1363 		case 7:
1364 			vc->vc_reverse = 1;
1365 			break;
1366 		case 10: /* ANSI X3.64-1979 (SCO-ish?)
1367 			  * Select primary font, don't display control chars if
1368 			  * defined, don't set bit 8 on output.
1369 			  */
1370 			vc->vc_translate = set_translate(vc->vc_charset == 0
1371 					? vc->vc_G0_charset
1372 					: vc->vc_G1_charset, vc);
1373 			vc->vc_disp_ctrl = 0;
1374 			vc->vc_toggle_meta = 0;
1375 			break;
1376 		case 11: /* ANSI X3.64-1979 (SCO-ish?)
1377 			  * Select first alternate font, lets chars < 32 be
1378 			  * displayed as ROM chars.
1379 			  */
1380 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1381 			vc->vc_disp_ctrl = 1;
1382 			vc->vc_toggle_meta = 0;
1383 			break;
1384 		case 12: /* ANSI X3.64-1979 (SCO-ish?)
1385 			  * Select second alternate font, toggle high bit
1386 			  * before displaying as ROM char.
1387 			  */
1388 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1389 			vc->vc_disp_ctrl = 1;
1390 			vc->vc_toggle_meta = 1;
1391 			break;
1392 		case 21:
1393 		case 22:
1394 			vc->vc_intensity = 1;
1395 			break;
1396 		case 23:
1397 			vc->vc_italic = 0;
1398 			break;
1399 		case 24:
1400 			vc->vc_underline = 0;
1401 			break;
1402 		case 25:
1403 			vc->vc_blink = 0;
1404 			break;
1405 		case 27:
1406 			vc->vc_reverse = 0;
1407 			break;
1408 		case 38:
1409 			i = vc_t416_color(vc, i, rgb_foreground);
1410 			break;
1411 		case 48:
1412 			i = vc_t416_color(vc, i, rgb_background);
1413 			break;
1414 		case 39:
1415 			vc->vc_color = (vc->vc_def_color & 0x0f) |
1416 				(vc->vc_color & 0xf0);
1417 			break;
1418 		case 49:
1419 			vc->vc_color = (vc->vc_def_color & 0xf0) |
1420 				(vc->vc_color & 0x0f);
1421 			break;
1422 		default:
1423 			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1424 				if (vc->vc_par[i] < 100)
1425 					vc->vc_intensity = 2;
1426 				vc->vc_par[i] -= 60;
1427 			}
1428 			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1429 				vc->vc_color = color_table[vc->vc_par[i] - 30]
1430 					| (vc->vc_color & 0xf0);
1431 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1432 				vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1433 					| (vc->vc_color & 0x0f);
1434 			break;
1435 		}
1436 	update_attr(vc);
1437 }
1438 
1439 static void respond_string(const char *p, struct tty_port *port)
1440 {
1441 	while (*p) {
1442 		tty_insert_flip_char(port, *p, 0);
1443 		p++;
1444 	}
1445 	tty_schedule_flip(port);
1446 }
1447 
1448 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1449 {
1450 	char buf[40];
1451 
1452 	sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1453 	respond_string(buf, tty->port);
1454 }
1455 
1456 static inline void status_report(struct tty_struct *tty)
1457 {
1458 	respond_string("\033[0n", tty->port);	/* Terminal ok */
1459 }
1460 
1461 static inline void respond_ID(struct tty_struct *tty)
1462 {
1463 	respond_string(VT102ID, tty->port);
1464 }
1465 
1466 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1467 {
1468 	char buf[8];
1469 
1470 	sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1471 		(char)('!' + mry));
1472 	respond_string(buf, tty->port);
1473 }
1474 
1475 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1476 int mouse_reporting(void)
1477 {
1478 	return vc_cons[fg_console].d->vc_report_mouse;
1479 }
1480 
1481 /* console_lock is held */
1482 static void set_mode(struct vc_data *vc, int on_off)
1483 {
1484 	int i;
1485 
1486 	for (i = 0; i <= vc->vc_npar; i++)
1487 		if (vc->vc_ques) {
1488 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1489 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1490 				if (on_off)
1491 					set_kbd(vc, decckm);
1492 				else
1493 					clr_kbd(vc, decckm);
1494 				break;
1495 			case 3:	/* 80/132 mode switch unimplemented */
1496 #if 0
1497 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1498 				/* this alone does not suffice; some user mode
1499 				   utility has to change the hardware regs */
1500 #endif
1501 				break;
1502 			case 5:			/* Inverted screen on/off */
1503 				if (vc->vc_decscnm != on_off) {
1504 					vc->vc_decscnm = on_off;
1505 					invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1506 					update_attr(vc);
1507 				}
1508 				break;
1509 			case 6:			/* Origin relative/absolute */
1510 				vc->vc_decom = on_off;
1511 				gotoxay(vc, 0, 0);
1512 				break;
1513 			case 7:			/* Autowrap on/off */
1514 				vc->vc_decawm = on_off;
1515 				break;
1516 			case 8:			/* Autorepeat on/off */
1517 				if (on_off)
1518 					set_kbd(vc, decarm);
1519 				else
1520 					clr_kbd(vc, decarm);
1521 				break;
1522 			case 9:
1523 				vc->vc_report_mouse = on_off ? 1 : 0;
1524 				break;
1525 			case 25:		/* Cursor on/off */
1526 				vc->vc_deccm = on_off;
1527 				break;
1528 			case 1000:
1529 				vc->vc_report_mouse = on_off ? 2 : 0;
1530 				break;
1531 			}
1532 		} else {
1533 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1534 			case 3:			/* Monitor (display ctrls) */
1535 				vc->vc_disp_ctrl = on_off;
1536 				break;
1537 			case 4:			/* Insert Mode on/off */
1538 				vc->vc_decim = on_off;
1539 				break;
1540 			case 20:		/* Lf, Enter == CrLf/Lf */
1541 				if (on_off)
1542 					set_kbd(vc, lnm);
1543 				else
1544 					clr_kbd(vc, lnm);
1545 				break;
1546 			}
1547 		}
1548 }
1549 
1550 /* console_lock is held */
1551 static void setterm_command(struct vc_data *vc)
1552 {
1553 	switch(vc->vc_par[0]) {
1554 		case 1:	/* set color for underline mode */
1555 			if (vc->vc_can_do_color &&
1556 					vc->vc_par[1] < 16) {
1557 				vc->vc_ulcolor = color_table[vc->vc_par[1]];
1558 				if (vc->vc_underline)
1559 					update_attr(vc);
1560 			}
1561 			break;
1562 		case 2:	/* set color for half intensity mode */
1563 			if (vc->vc_can_do_color &&
1564 					vc->vc_par[1] < 16) {
1565 				vc->vc_halfcolor = color_table[vc->vc_par[1]];
1566 				if (vc->vc_intensity == 0)
1567 					update_attr(vc);
1568 			}
1569 			break;
1570 		case 8:	/* store colors as defaults */
1571 			vc->vc_def_color = vc->vc_attr;
1572 			if (vc->vc_hi_font_mask == 0x100)
1573 				vc->vc_def_color >>= 1;
1574 			default_attr(vc);
1575 			update_attr(vc);
1576 			break;
1577 		case 9:	/* set blanking interval */
1578 			blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1579 			poke_blanked_console();
1580 			break;
1581 		case 10: /* set bell frequency in Hz */
1582 			if (vc->vc_npar >= 1)
1583 				vc->vc_bell_pitch = vc->vc_par[1];
1584 			else
1585 				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1586 			break;
1587 		case 11: /* set bell duration in msec */
1588 			if (vc->vc_npar >= 1)
1589 				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1590 					msecs_to_jiffies(vc->vc_par[1]) : 0;
1591 			else
1592 				vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1593 			break;
1594 		case 12: /* bring specified console to the front */
1595 			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1596 				set_console(vc->vc_par[1] - 1);
1597 			break;
1598 		case 13: /* unblank the screen */
1599 			poke_blanked_console();
1600 			break;
1601 		case 14: /* set vesa powerdown interval */
1602 			vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1603 			break;
1604 		case 15: /* activate the previous console */
1605 			set_console(last_console);
1606 			break;
1607 		case 16: /* set cursor blink duration in msec */
1608 			if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1609 					vc->vc_par[1] <= USHRT_MAX)
1610 				vc->vc_cur_blink_ms = vc->vc_par[1];
1611 			else
1612 				vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1613 			break;
1614 	}
1615 }
1616 
1617 /* console_lock is held */
1618 static void csi_at(struct vc_data *vc, unsigned int nr)
1619 {
1620 	if (nr > vc->vc_cols - vc->vc_x)
1621 		nr = vc->vc_cols - vc->vc_x;
1622 	else if (!nr)
1623 		nr = 1;
1624 	insert_char(vc, nr);
1625 }
1626 
1627 /* console_lock is held */
1628 static void csi_L(struct vc_data *vc, unsigned int nr)
1629 {
1630 	if (nr > vc->vc_rows - vc->vc_y)
1631 		nr = vc->vc_rows - vc->vc_y;
1632 	else if (!nr)
1633 		nr = 1;
1634 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_DOWN, nr);
1635 	vc->vc_need_wrap = 0;
1636 }
1637 
1638 /* console_lock is held */
1639 static void csi_P(struct vc_data *vc, unsigned int nr)
1640 {
1641 	if (nr > vc->vc_cols - vc->vc_x)
1642 		nr = vc->vc_cols - vc->vc_x;
1643 	else if (!nr)
1644 		nr = 1;
1645 	delete_char(vc, nr);
1646 }
1647 
1648 /* console_lock is held */
1649 static void csi_M(struct vc_data *vc, unsigned int nr)
1650 {
1651 	if (nr > vc->vc_rows - vc->vc_y)
1652 		nr = vc->vc_rows - vc->vc_y;
1653 	else if (!nr)
1654 		nr=1;
1655 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_UP, nr);
1656 	vc->vc_need_wrap = 0;
1657 }
1658 
1659 /* console_lock is held (except via vc_init->reset_terminal */
1660 static void save_cur(struct vc_data *vc)
1661 {
1662 	vc->vc_saved_x		= vc->vc_x;
1663 	vc->vc_saved_y		= vc->vc_y;
1664 	vc->vc_s_intensity	= vc->vc_intensity;
1665 	vc->vc_s_italic         = vc->vc_italic;
1666 	vc->vc_s_underline	= vc->vc_underline;
1667 	vc->vc_s_blink		= vc->vc_blink;
1668 	vc->vc_s_reverse	= vc->vc_reverse;
1669 	vc->vc_s_charset	= vc->vc_charset;
1670 	vc->vc_s_color		= vc->vc_color;
1671 	vc->vc_saved_G0		= vc->vc_G0_charset;
1672 	vc->vc_saved_G1		= vc->vc_G1_charset;
1673 }
1674 
1675 /* console_lock is held */
1676 static void restore_cur(struct vc_data *vc)
1677 {
1678 	gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
1679 	vc->vc_intensity	= vc->vc_s_intensity;
1680 	vc->vc_italic		= vc->vc_s_italic;
1681 	vc->vc_underline	= vc->vc_s_underline;
1682 	vc->vc_blink		= vc->vc_s_blink;
1683 	vc->vc_reverse		= vc->vc_s_reverse;
1684 	vc->vc_charset		= vc->vc_s_charset;
1685 	vc->vc_color		= vc->vc_s_color;
1686 	vc->vc_G0_charset	= vc->vc_saved_G0;
1687 	vc->vc_G1_charset	= vc->vc_saved_G1;
1688 	vc->vc_translate	= set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
1689 	update_attr(vc);
1690 	vc->vc_need_wrap = 0;
1691 }
1692 
1693 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
1694 	EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
1695 	ESpalette, ESosc };
1696 
1697 /* console_lock is held (except via vc_init()) */
1698 static void reset_terminal(struct vc_data *vc, int do_clear)
1699 {
1700 	vc->vc_top		= 0;
1701 	vc->vc_bottom		= vc->vc_rows;
1702 	vc->vc_state		= ESnormal;
1703 	vc->vc_ques		= 0;
1704 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
1705 	vc->vc_G0_charset	= LAT1_MAP;
1706 	vc->vc_G1_charset	= GRAF_MAP;
1707 	vc->vc_charset		= 0;
1708 	vc->vc_need_wrap	= 0;
1709 	vc->vc_report_mouse	= 0;
1710 	vc->vc_utf              = default_utf8;
1711 	vc->vc_utf_count	= 0;
1712 
1713 	vc->vc_disp_ctrl	= 0;
1714 	vc->vc_toggle_meta	= 0;
1715 
1716 	vc->vc_decscnm		= 0;
1717 	vc->vc_decom		= 0;
1718 	vc->vc_decawm		= 1;
1719 	vc->vc_deccm		= global_cursor_default;
1720 	vc->vc_decim		= 0;
1721 
1722 	vt_reset_keyboard(vc->vc_num);
1723 
1724 	vc->vc_cursor_type = cur_default;
1725 	vc->vc_complement_mask = vc->vc_s_complement_mask;
1726 
1727 	default_attr(vc);
1728 	update_attr(vc);
1729 
1730 	vc->vc_tab_stop[0]	= 0x01010100;
1731 	vc->vc_tab_stop[1]	=
1732 	vc->vc_tab_stop[2]	=
1733 	vc->vc_tab_stop[3]	=
1734 	vc->vc_tab_stop[4]	=
1735 	vc->vc_tab_stop[5]	=
1736 	vc->vc_tab_stop[6]	=
1737 	vc->vc_tab_stop[7]	= 0x01010101;
1738 
1739 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1740 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1741 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1742 
1743 	gotoxy(vc, 0, 0);
1744 	save_cur(vc);
1745 	if (do_clear)
1746 	    csi_J(vc, 2);
1747 }
1748 
1749 /* console_lock is held */
1750 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
1751 {
1752 	/*
1753 	 *  Control characters can be used in the _middle_
1754 	 *  of an escape sequence.
1755 	 */
1756 	if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
1757 		return;
1758 	switch (c) {
1759 	case 0:
1760 		return;
1761 	case 7:
1762 		if (vc->vc_state == ESosc)
1763 			vc->vc_state = ESnormal;
1764 		else if (vc->vc_bell_duration)
1765 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
1766 		return;
1767 	case 8:
1768 		bs(vc);
1769 		return;
1770 	case 9:
1771 		vc->vc_pos -= (vc->vc_x << 1);
1772 		while (vc->vc_x < vc->vc_cols - 1) {
1773 			vc->vc_x++;
1774 			if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
1775 				break;
1776 		}
1777 		vc->vc_pos += (vc->vc_x << 1);
1778 		notify_write(vc, '\t');
1779 		return;
1780 	case 10: case 11: case 12:
1781 		lf(vc);
1782 		if (!is_kbd(vc, lnm))
1783 			return;
1784 	case 13:
1785 		cr(vc);
1786 		return;
1787 	case 14:
1788 		vc->vc_charset = 1;
1789 		vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
1790 		vc->vc_disp_ctrl = 1;
1791 		return;
1792 	case 15:
1793 		vc->vc_charset = 0;
1794 		vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
1795 		vc->vc_disp_ctrl = 0;
1796 		return;
1797 	case 24: case 26:
1798 		vc->vc_state = ESnormal;
1799 		return;
1800 	case 27:
1801 		vc->vc_state = ESesc;
1802 		return;
1803 	case 127:
1804 		del(vc);
1805 		return;
1806 	case 128+27:
1807 		vc->vc_state = ESsquare;
1808 		return;
1809 	}
1810 	switch(vc->vc_state) {
1811 	case ESesc:
1812 		vc->vc_state = ESnormal;
1813 		switch (c) {
1814 		case '[':
1815 			vc->vc_state = ESsquare;
1816 			return;
1817 		case ']':
1818 			vc->vc_state = ESnonstd;
1819 			return;
1820 		case '%':
1821 			vc->vc_state = ESpercent;
1822 			return;
1823 		case 'E':
1824 			cr(vc);
1825 			lf(vc);
1826 			return;
1827 		case 'M':
1828 			ri(vc);
1829 			return;
1830 		case 'D':
1831 			lf(vc);
1832 			return;
1833 		case 'H':
1834 			vc->vc_tab_stop[vc->vc_x >> 5] |= (1 << (vc->vc_x & 31));
1835 			return;
1836 		case 'Z':
1837 			respond_ID(tty);
1838 			return;
1839 		case '7':
1840 			save_cur(vc);
1841 			return;
1842 		case '8':
1843 			restore_cur(vc);
1844 			return;
1845 		case '(':
1846 			vc->vc_state = ESsetG0;
1847 			return;
1848 		case ')':
1849 			vc->vc_state = ESsetG1;
1850 			return;
1851 		case '#':
1852 			vc->vc_state = EShash;
1853 			return;
1854 		case 'c':
1855 			reset_terminal(vc, 1);
1856 			return;
1857 		case '>':  /* Numeric keypad */
1858 			clr_kbd(vc, kbdapplic);
1859 			return;
1860 		case '=':  /* Appl. keypad */
1861 			set_kbd(vc, kbdapplic);
1862 			return;
1863 		}
1864 		return;
1865 	case ESnonstd:
1866 		if (c=='P') {   /* palette escape sequence */
1867 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1868 				vc->vc_par[vc->vc_npar] = 0;
1869 			vc->vc_npar = 0;
1870 			vc->vc_state = ESpalette;
1871 			return;
1872 		} else if (c=='R') {   /* reset palette */
1873 			reset_palette(vc);
1874 			vc->vc_state = ESnormal;
1875 		} else if (c>='0' && c<='9')
1876 			vc->vc_state = ESosc;
1877 		else
1878 			vc->vc_state = ESnormal;
1879 		return;
1880 	case ESpalette:
1881 		if (isxdigit(c)) {
1882 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
1883 			if (vc->vc_npar == 7) {
1884 				int i = vc->vc_par[0] * 3, j = 1;
1885 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1886 				vc->vc_palette[i++] += vc->vc_par[j++];
1887 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1888 				vc->vc_palette[i++] += vc->vc_par[j++];
1889 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1890 				vc->vc_palette[i] += vc->vc_par[j];
1891 				set_palette(vc);
1892 				vc->vc_state = ESnormal;
1893 			}
1894 		} else
1895 			vc->vc_state = ESnormal;
1896 		return;
1897 	case ESsquare:
1898 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1899 			vc->vc_par[vc->vc_npar] = 0;
1900 		vc->vc_npar = 0;
1901 		vc->vc_state = ESgetpars;
1902 		if (c == '[') { /* Function key */
1903 			vc->vc_state=ESfunckey;
1904 			return;
1905 		}
1906 		vc->vc_ques = (c == '?');
1907 		if (vc->vc_ques)
1908 			return;
1909 	case ESgetpars:
1910 		if (c == ';' && vc->vc_npar < NPAR - 1) {
1911 			vc->vc_npar++;
1912 			return;
1913 		} else if (c>='0' && c<='9') {
1914 			vc->vc_par[vc->vc_npar] *= 10;
1915 			vc->vc_par[vc->vc_npar] += c - '0';
1916 			return;
1917 		}
1918 		vc->vc_state = ESnormal;
1919 		switch(c) {
1920 		case 'h':
1921 			set_mode(vc, 1);
1922 			return;
1923 		case 'l':
1924 			set_mode(vc, 0);
1925 			return;
1926 		case 'c':
1927 			if (vc->vc_ques) {
1928 				if (vc->vc_par[0])
1929 					vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
1930 				else
1931 					vc->vc_cursor_type = cur_default;
1932 				return;
1933 			}
1934 			break;
1935 		case 'm':
1936 			if (vc->vc_ques) {
1937 				clear_selection();
1938 				if (vc->vc_par[0])
1939 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
1940 				else
1941 					vc->vc_complement_mask = vc->vc_s_complement_mask;
1942 				return;
1943 			}
1944 			break;
1945 		case 'n':
1946 			if (!vc->vc_ques) {
1947 				if (vc->vc_par[0] == 5)
1948 					status_report(tty);
1949 				else if (vc->vc_par[0] == 6)
1950 					cursor_report(vc, tty);
1951 			}
1952 			return;
1953 		}
1954 		if (vc->vc_ques) {
1955 			vc->vc_ques = 0;
1956 			return;
1957 		}
1958 		switch(c) {
1959 		case 'G': case '`':
1960 			if (vc->vc_par[0])
1961 				vc->vc_par[0]--;
1962 			gotoxy(vc, vc->vc_par[0], vc->vc_y);
1963 			return;
1964 		case 'A':
1965 			if (!vc->vc_par[0])
1966 				vc->vc_par[0]++;
1967 			gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
1968 			return;
1969 		case 'B': case 'e':
1970 			if (!vc->vc_par[0])
1971 				vc->vc_par[0]++;
1972 			gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
1973 			return;
1974 		case 'C': case 'a':
1975 			if (!vc->vc_par[0])
1976 				vc->vc_par[0]++;
1977 			gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
1978 			return;
1979 		case 'D':
1980 			if (!vc->vc_par[0])
1981 				vc->vc_par[0]++;
1982 			gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
1983 			return;
1984 		case 'E':
1985 			if (!vc->vc_par[0])
1986 				vc->vc_par[0]++;
1987 			gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
1988 			return;
1989 		case 'F':
1990 			if (!vc->vc_par[0])
1991 				vc->vc_par[0]++;
1992 			gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
1993 			return;
1994 		case 'd':
1995 			if (vc->vc_par[0])
1996 				vc->vc_par[0]--;
1997 			gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
1998 			return;
1999 		case 'H': case 'f':
2000 			if (vc->vc_par[0])
2001 				vc->vc_par[0]--;
2002 			if (vc->vc_par[1])
2003 				vc->vc_par[1]--;
2004 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2005 			return;
2006 		case 'J':
2007 			csi_J(vc, vc->vc_par[0]);
2008 			return;
2009 		case 'K':
2010 			csi_K(vc, vc->vc_par[0]);
2011 			return;
2012 		case 'L':
2013 			csi_L(vc, vc->vc_par[0]);
2014 			return;
2015 		case 'M':
2016 			csi_M(vc, vc->vc_par[0]);
2017 			return;
2018 		case 'P':
2019 			csi_P(vc, vc->vc_par[0]);
2020 			return;
2021 		case 'c':
2022 			if (!vc->vc_par[0])
2023 				respond_ID(tty);
2024 			return;
2025 		case 'g':
2026 			if (!vc->vc_par[0])
2027 				vc->vc_tab_stop[vc->vc_x >> 5] &= ~(1 << (vc->vc_x & 31));
2028 			else if (vc->vc_par[0] == 3) {
2029 				vc->vc_tab_stop[0] =
2030 					vc->vc_tab_stop[1] =
2031 					vc->vc_tab_stop[2] =
2032 					vc->vc_tab_stop[3] =
2033 					vc->vc_tab_stop[4] =
2034 					vc->vc_tab_stop[5] =
2035 					vc->vc_tab_stop[6] =
2036 					vc->vc_tab_stop[7] = 0;
2037 			}
2038 			return;
2039 		case 'm':
2040 			csi_m(vc);
2041 			return;
2042 		case 'q': /* DECLL - but only 3 leds */
2043 			/* map 0,1,2,3 to 0,1,2,4 */
2044 			if (vc->vc_par[0] < 4)
2045 				vt_set_led_state(vc->vc_num,
2046 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2047 			return;
2048 		case 'r':
2049 			if (!vc->vc_par[0])
2050 				vc->vc_par[0]++;
2051 			if (!vc->vc_par[1])
2052 				vc->vc_par[1] = vc->vc_rows;
2053 			/* Minimum allowed region is 2 lines */
2054 			if (vc->vc_par[0] < vc->vc_par[1] &&
2055 			    vc->vc_par[1] <= vc->vc_rows) {
2056 				vc->vc_top = vc->vc_par[0] - 1;
2057 				vc->vc_bottom = vc->vc_par[1];
2058 				gotoxay(vc, 0, 0);
2059 			}
2060 			return;
2061 		case 's':
2062 			save_cur(vc);
2063 			return;
2064 		case 'u':
2065 			restore_cur(vc);
2066 			return;
2067 		case 'X':
2068 			csi_X(vc, vc->vc_par[0]);
2069 			return;
2070 		case '@':
2071 			csi_at(vc, vc->vc_par[0]);
2072 			return;
2073 		case ']': /* setterm functions */
2074 			setterm_command(vc);
2075 			return;
2076 		}
2077 		return;
2078 	case ESpercent:
2079 		vc->vc_state = ESnormal;
2080 		switch (c) {
2081 		case '@':  /* defined in ISO 2022 */
2082 			vc->vc_utf = 0;
2083 			return;
2084 		case 'G':  /* prelim official escape code */
2085 		case '8':  /* retained for compatibility */
2086 			vc->vc_utf = 1;
2087 			return;
2088 		}
2089 		return;
2090 	case ESfunckey:
2091 		vc->vc_state = ESnormal;
2092 		return;
2093 	case EShash:
2094 		vc->vc_state = ESnormal;
2095 		if (c == '8') {
2096 			/* DEC screen alignment test. kludge :-) */
2097 			vc->vc_video_erase_char =
2098 				(vc->vc_video_erase_char & 0xff00) | 'E';
2099 			csi_J(vc, 2);
2100 			vc->vc_video_erase_char =
2101 				(vc->vc_video_erase_char & 0xff00) | ' ';
2102 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2103 		}
2104 		return;
2105 	case ESsetG0:
2106 		if (c == '0')
2107 			vc->vc_G0_charset = GRAF_MAP;
2108 		else if (c == 'B')
2109 			vc->vc_G0_charset = LAT1_MAP;
2110 		else if (c == 'U')
2111 			vc->vc_G0_charset = IBMPC_MAP;
2112 		else if (c == 'K')
2113 			vc->vc_G0_charset = USER_MAP;
2114 		if (vc->vc_charset == 0)
2115 			vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2116 		vc->vc_state = ESnormal;
2117 		return;
2118 	case ESsetG1:
2119 		if (c == '0')
2120 			vc->vc_G1_charset = GRAF_MAP;
2121 		else if (c == 'B')
2122 			vc->vc_G1_charset = LAT1_MAP;
2123 		else if (c == 'U')
2124 			vc->vc_G1_charset = IBMPC_MAP;
2125 		else if (c == 'K')
2126 			vc->vc_G1_charset = USER_MAP;
2127 		if (vc->vc_charset == 1)
2128 			vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2129 		vc->vc_state = ESnormal;
2130 		return;
2131 	case ESosc:
2132 		return;
2133 	default:
2134 		vc->vc_state = ESnormal;
2135 	}
2136 }
2137 
2138 /* is_double_width() is based on the wcwidth() implementation by
2139  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2140  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2141  */
2142 struct interval {
2143 	uint32_t first;
2144 	uint32_t last;
2145 };
2146 
2147 static int ucs_cmp(const void *key, const void *elt)
2148 {
2149 	uint32_t ucs = *(uint32_t *)key;
2150 	struct interval e = *(struct interval *) elt;
2151 
2152 	if (ucs > e.last)
2153 		return 1;
2154 	else if (ucs < e.first)
2155 		return -1;
2156 	return 0;
2157 }
2158 
2159 static int is_double_width(uint32_t ucs)
2160 {
2161 	static const struct interval double_width[] = {
2162 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2163 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2164 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2165 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2166 	};
2167 	if (ucs < double_width[0].first ||
2168 	    ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2169 		return 0;
2170 
2171 	return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2172 			sizeof(struct interval), ucs_cmp) != NULL;
2173 }
2174 
2175 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2176 		unsigned long draw_to, int *draw_x)
2177 {
2178 	if (*draw_x < 0)
2179 		return;
2180 
2181 	vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2182 			(u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2183 	*draw_x = -1;
2184 }
2185 
2186 /* acquires console_lock */
2187 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2188 {
2189 	int c, tc, ok, n = 0, draw_x = -1;
2190 	unsigned int currcons;
2191 	unsigned long draw_from = 0, draw_to = 0;
2192 	struct vc_data *vc;
2193 	unsigned char vc_attr;
2194 	struct vt_notifier_param param;
2195 	uint8_t rescan;
2196 	uint8_t inverse;
2197 	uint8_t width;
2198 	u16 himask, charmask;
2199 
2200 	if (in_interrupt())
2201 		return count;
2202 
2203 	might_sleep();
2204 
2205 	console_lock();
2206 	vc = tty->driver_data;
2207 	if (vc == NULL) {
2208 		pr_err("vt: argh, driver_data is NULL !\n");
2209 		console_unlock();
2210 		return 0;
2211 	}
2212 
2213 	currcons = vc->vc_num;
2214 	if (!vc_cons_allocated(currcons)) {
2215 		/* could this happen? */
2216 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2217 		console_unlock();
2218 		return 0;
2219 	}
2220 
2221 	himask = vc->vc_hi_font_mask;
2222 	charmask = himask ? 0x1ff : 0xff;
2223 
2224 	/* undraw cursor first */
2225 	if (con_is_fg(vc))
2226 		hide_cursor(vc);
2227 
2228 	param.vc = vc;
2229 
2230 	while (!tty->stopped && count) {
2231 		int orig = *buf;
2232 		c = orig;
2233 		buf++;
2234 		n++;
2235 		count--;
2236 		rescan = 0;
2237 		inverse = 0;
2238 		width = 1;
2239 
2240 		/* Do no translation at all in control states */
2241 		if (vc->vc_state != ESnormal) {
2242 			tc = c;
2243 		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2244 		    /* Combine UTF-8 into Unicode in vc_utf_char.
2245 		     * vc_utf_count is the number of continuation bytes still
2246 		     * expected to arrive.
2247 		     * vc_npar is the number of continuation bytes arrived so
2248 		     * far
2249 		     */
2250 rescan_last_byte:
2251 		    if ((c & 0xc0) == 0x80) {
2252 			/* Continuation byte received */
2253 			static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2254 			if (vc->vc_utf_count) {
2255 			    vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2256 			    vc->vc_npar++;
2257 			    if (--vc->vc_utf_count) {
2258 				/* Still need some bytes */
2259 				continue;
2260 			    }
2261 			    /* Got a whole character */
2262 			    c = vc->vc_utf_char;
2263 			    /* Reject overlong sequences */
2264 			    if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2265 					c > utf8_length_changes[vc->vc_npar])
2266 				c = 0xfffd;
2267 			} else {
2268 			    /* Unexpected continuation byte */
2269 			    vc->vc_utf_count = 0;
2270 			    c = 0xfffd;
2271 			}
2272 		    } else {
2273 			/* Single ASCII byte or first byte of a sequence received */
2274 			if (vc->vc_utf_count) {
2275 			    /* Continuation byte expected */
2276 			    rescan = 1;
2277 			    vc->vc_utf_count = 0;
2278 			    c = 0xfffd;
2279 			} else if (c > 0x7f) {
2280 			    /* First byte of a multibyte sequence received */
2281 			    vc->vc_npar = 0;
2282 			    if ((c & 0xe0) == 0xc0) {
2283 				vc->vc_utf_count = 1;
2284 				vc->vc_utf_char = (c & 0x1f);
2285 			    } else if ((c & 0xf0) == 0xe0) {
2286 				vc->vc_utf_count = 2;
2287 				vc->vc_utf_char = (c & 0x0f);
2288 			    } else if ((c & 0xf8) == 0xf0) {
2289 				vc->vc_utf_count = 3;
2290 				vc->vc_utf_char = (c & 0x07);
2291 			    } else if ((c & 0xfc) == 0xf8) {
2292 				vc->vc_utf_count = 4;
2293 				vc->vc_utf_char = (c & 0x03);
2294 			    } else if ((c & 0xfe) == 0xfc) {
2295 				vc->vc_utf_count = 5;
2296 				vc->vc_utf_char = (c & 0x01);
2297 			    } else {
2298 				/* 254 and 255 are invalid */
2299 				c = 0xfffd;
2300 			    }
2301 			    if (vc->vc_utf_count) {
2302 				/* Still need some bytes */
2303 				continue;
2304 			    }
2305 			}
2306 			/* Nothing to do if an ASCII byte was received */
2307 		    }
2308 		    /* End of UTF-8 decoding. */
2309 		    /* c is the received character, or U+FFFD for invalid sequences. */
2310 		    /* Replace invalid Unicode code points with U+FFFD too */
2311 		    if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2312 			c = 0xfffd;
2313 		    tc = c;
2314 		} else {	/* no utf or alternate charset mode */
2315 		    tc = vc_translate(vc, c);
2316 		}
2317 
2318 		param.c = tc;
2319 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2320 					&param) == NOTIFY_STOP)
2321 			continue;
2322 
2323                 /* If the original code was a control character we
2324                  * only allow a glyph to be displayed if the code is
2325                  * not normally used (such as for cursor movement) or
2326                  * if the disp_ctrl mode has been explicitly enabled.
2327                  * Certain characters (as given by the CTRL_ALWAYS
2328                  * bitmap) are always displayed as control characters,
2329                  * as the console would be pretty useless without
2330                  * them; to display an arbitrary font position use the
2331                  * direct-to-font zone in UTF-8 mode.
2332                  */
2333                 ok = tc && (c >= 32 ||
2334 			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2335 				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2336 			&& (c != 127 || vc->vc_disp_ctrl)
2337 			&& (c != 128+27);
2338 
2339 		if (vc->vc_state == ESnormal && ok) {
2340 			if (vc->vc_utf && !vc->vc_disp_ctrl) {
2341 				if (is_double_width(c))
2342 					width = 2;
2343 			}
2344 			/* Now try to find out how to display it */
2345 			tc = conv_uni_to_pc(vc, tc);
2346 			if (tc & ~charmask) {
2347 				if (tc == -1 || tc == -2) {
2348 				    continue; /* nothing to display */
2349 				}
2350 				/* Glyph not found */
2351 				if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2352 				    /* In legacy mode use the glyph we get by a 1:1 mapping.
2353 				       This would make absolutely no sense with Unicode in mind,
2354 				       but do this for ASCII characters since a font may lack
2355 				       Unicode mapping info and we don't want to end up with
2356 				       having question marks only. */
2357 				    tc = c;
2358 				} else {
2359 				    /* Display U+FFFD. If it's not found, display an inverse question mark. */
2360 				    tc = conv_uni_to_pc(vc, 0xfffd);
2361 				    if (tc < 0) {
2362 					inverse = 1;
2363 					tc = conv_uni_to_pc(vc, '?');
2364 					if (tc < 0) tc = '?';
2365 				    }
2366 				}
2367 			}
2368 
2369 			if (!inverse) {
2370 				vc_attr = vc->vc_attr;
2371 			} else {
2372 				/* invert vc_attr */
2373 				if (!vc->vc_can_do_color) {
2374 					vc_attr = (vc->vc_attr) ^ 0x08;
2375 				} else if (vc->vc_hi_font_mask == 0x100) {
2376 					vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2377 				} else {
2378 					vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2379 				}
2380 				con_flush(vc, draw_from, draw_to, &draw_x);
2381 			}
2382 
2383 			while (1) {
2384 				if (vc->vc_need_wrap || vc->vc_decim)
2385 					con_flush(vc, draw_from, draw_to,
2386 							&draw_x);
2387 				if (vc->vc_need_wrap) {
2388 					cr(vc);
2389 					lf(vc);
2390 				}
2391 				if (vc->vc_decim)
2392 					insert_char(vc, 1);
2393 				scr_writew(himask ?
2394 					     ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2395 					     (vc_attr << 8) + tc,
2396 					   (u16 *) vc->vc_pos);
2397 				if (con_should_update(vc) && draw_x < 0) {
2398 					draw_x = vc->vc_x;
2399 					draw_from = vc->vc_pos;
2400 				}
2401 				if (vc->vc_x == vc->vc_cols - 1) {
2402 					vc->vc_need_wrap = vc->vc_decawm;
2403 					draw_to = vc->vc_pos + 2;
2404 				} else {
2405 					vc->vc_x++;
2406 					draw_to = (vc->vc_pos += 2);
2407 				}
2408 
2409 				if (!--width) break;
2410 
2411 				tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2412 				if (tc < 0) tc = ' ';
2413 			}
2414 			notify_write(vc, c);
2415 
2416 			if (inverse)
2417 				con_flush(vc, draw_from, draw_to, &draw_x);
2418 
2419 			if (rescan) {
2420 				rescan = 0;
2421 				inverse = 0;
2422 				width = 1;
2423 				c = orig;
2424 				goto rescan_last_byte;
2425 			}
2426 			continue;
2427 		}
2428 		con_flush(vc, draw_from, draw_to, &draw_x);
2429 		do_con_trol(tty, vc, orig);
2430 	}
2431 	con_flush(vc, draw_from, draw_to, &draw_x);
2432 	console_conditional_schedule();
2433 	console_unlock();
2434 	notify_update(vc);
2435 	return n;
2436 }
2437 
2438 /*
2439  * This is the console switching callback.
2440  *
2441  * Doing console switching in a process context allows
2442  * us to do the switches asynchronously (needed when we want
2443  * to switch due to a keyboard interrupt).  Synchronization
2444  * with other console code and prevention of re-entrancy is
2445  * ensured with console_lock.
2446  */
2447 static void console_callback(struct work_struct *ignored)
2448 {
2449 	console_lock();
2450 
2451 	if (want_console >= 0) {
2452 		if (want_console != fg_console &&
2453 		    vc_cons_allocated(want_console)) {
2454 			hide_cursor(vc_cons[fg_console].d);
2455 			change_console(vc_cons[want_console].d);
2456 			/* we only changed when the console had already
2457 			   been allocated - a new console is not created
2458 			   in an interrupt routine */
2459 		}
2460 		want_console = -1;
2461 	}
2462 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2463 		do_poke_blanked_console = 0;
2464 		poke_blanked_console();
2465 	}
2466 	if (scrollback_delta) {
2467 		struct vc_data *vc = vc_cons[fg_console].d;
2468 		clear_selection();
2469 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2470 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2471 		scrollback_delta = 0;
2472 	}
2473 	if (blank_timer_expired) {
2474 		do_blank_screen(0);
2475 		blank_timer_expired = 0;
2476 	}
2477 	notify_update(vc_cons[fg_console].d);
2478 
2479 	console_unlock();
2480 }
2481 
2482 int set_console(int nr)
2483 {
2484 	struct vc_data *vc = vc_cons[fg_console].d;
2485 
2486 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
2487 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2488 
2489 		/*
2490 		 * Console switch will fail in console_callback() or
2491 		 * change_console() so there is no point scheduling
2492 		 * the callback
2493 		 *
2494 		 * Existing set_console() users don't check the return
2495 		 * value so this shouldn't break anything
2496 		 */
2497 		return -EINVAL;
2498 	}
2499 
2500 	want_console = nr;
2501 	schedule_console_callback();
2502 
2503 	return 0;
2504 }
2505 
2506 struct tty_driver *console_driver;
2507 
2508 #ifdef CONFIG_VT_CONSOLE
2509 
2510 /**
2511  * vt_kmsg_redirect() - Sets/gets the kernel message console
2512  * @new:	The new virtual terminal number or -1 if the console should stay
2513  * 		unchanged
2514  *
2515  * By default, the kernel messages are always printed on the current virtual
2516  * console. However, the user may modify that default with the
2517  * TIOCL_SETKMSGREDIRECT ioctl call.
2518  *
2519  * This function sets the kernel message console to be @new. It returns the old
2520  * virtual console number. The virtual terminal number 0 (both as parameter and
2521  * return value) means no redirection (i.e. always printed on the currently
2522  * active console).
2523  *
2524  * The parameter -1 means that only the current console is returned, but the
2525  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2526  * case to make the code more understandable.
2527  *
2528  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2529  * the parameter and always returns 0.
2530  */
2531 int vt_kmsg_redirect(int new)
2532 {
2533 	static int kmsg_con;
2534 
2535 	if (new != -1)
2536 		return xchg(&kmsg_con, new);
2537 	else
2538 		return kmsg_con;
2539 }
2540 
2541 /*
2542  *	Console on virtual terminal
2543  *
2544  * The console must be locked when we get here.
2545  */
2546 
2547 static void vt_console_print(struct console *co, const char *b, unsigned count)
2548 {
2549 	struct vc_data *vc = vc_cons[fg_console].d;
2550 	unsigned char c;
2551 	static DEFINE_SPINLOCK(printing_lock);
2552 	const ushort *start;
2553 	ushort cnt = 0;
2554 	ushort myx;
2555 	int kmsg_console;
2556 
2557 	/* console busy or not yet initialized */
2558 	if (!printable)
2559 		return;
2560 	if (!spin_trylock(&printing_lock))
2561 		return;
2562 
2563 	kmsg_console = vt_get_kmsg_redirect();
2564 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2565 		vc = vc_cons[kmsg_console - 1].d;
2566 
2567 	/* read `x' only after setting currcons properly (otherwise
2568 	   the `x' macro will read the x of the foreground console). */
2569 	myx = vc->vc_x;
2570 
2571 	if (!vc_cons_allocated(fg_console)) {
2572 		/* impossible */
2573 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2574 		goto quit;
2575 	}
2576 
2577 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
2578 		goto quit;
2579 
2580 	/* undraw cursor first */
2581 	if (con_is_fg(vc))
2582 		hide_cursor(vc);
2583 
2584 	start = (ushort *)vc->vc_pos;
2585 
2586 	/* Contrived structure to try to emulate original need_wrap behaviour
2587 	 * Problems caused when we have need_wrap set on '\n' character */
2588 	while (count--) {
2589 		c = *b++;
2590 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2591 			if (cnt > 0) {
2592 				if (con_is_visible(vc))
2593 					vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2594 				vc->vc_x += cnt;
2595 				if (vc->vc_need_wrap)
2596 					vc->vc_x--;
2597 				cnt = 0;
2598 			}
2599 			if (c == 8) {		/* backspace */
2600 				bs(vc);
2601 				start = (ushort *)vc->vc_pos;
2602 				myx = vc->vc_x;
2603 				continue;
2604 			}
2605 			if (c != 13)
2606 				lf(vc);
2607 			cr(vc);
2608 			start = (ushort *)vc->vc_pos;
2609 			myx = vc->vc_x;
2610 			if (c == 10 || c == 13)
2611 				continue;
2612 		}
2613 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2614 		notify_write(vc, c);
2615 		cnt++;
2616 		if (myx == vc->vc_cols - 1) {
2617 			vc->vc_need_wrap = 1;
2618 			continue;
2619 		}
2620 		vc->vc_pos += 2;
2621 		myx++;
2622 	}
2623 	if (cnt > 0) {
2624 		if (con_is_visible(vc))
2625 			vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2626 		vc->vc_x += cnt;
2627 		if (vc->vc_x == vc->vc_cols) {
2628 			vc->vc_x--;
2629 			vc->vc_need_wrap = 1;
2630 		}
2631 	}
2632 	set_cursor(vc);
2633 	notify_update(vc);
2634 
2635 quit:
2636 	spin_unlock(&printing_lock);
2637 }
2638 
2639 static struct tty_driver *vt_console_device(struct console *c, int *index)
2640 {
2641 	*index = c->index ? c->index-1 : fg_console;
2642 	return console_driver;
2643 }
2644 
2645 static struct console vt_console_driver = {
2646 	.name		= "tty",
2647 	.write		= vt_console_print,
2648 	.device		= vt_console_device,
2649 	.unblank	= unblank_screen,
2650 	.flags		= CON_PRINTBUFFER,
2651 	.index		= -1,
2652 };
2653 #endif
2654 
2655 /*
2656  *	Handling of Linux-specific VC ioctls
2657  */
2658 
2659 /*
2660  * Generally a bit racy with respect to console_lock();.
2661  *
2662  * There are some functions which don't need it.
2663  *
2664  * There are some functions which can sleep for arbitrary periods
2665  * (paste_selection) but we don't need the lock there anyway.
2666  *
2667  * set_selection has locking, and definitely needs it
2668  */
2669 
2670 int tioclinux(struct tty_struct *tty, unsigned long arg)
2671 {
2672 	char type, data;
2673 	char __user *p = (char __user *)arg;
2674 	int lines;
2675 	int ret;
2676 
2677 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
2678 		return -EPERM;
2679 	if (get_user(type, p))
2680 		return -EFAULT;
2681 	ret = 0;
2682 
2683 	switch (type)
2684 	{
2685 		case TIOCL_SETSEL:
2686 			console_lock();
2687 			ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
2688 			console_unlock();
2689 			break;
2690 		case TIOCL_PASTESEL:
2691 			ret = paste_selection(tty);
2692 			break;
2693 		case TIOCL_UNBLANKSCREEN:
2694 			console_lock();
2695 			unblank_screen();
2696 			console_unlock();
2697 			break;
2698 		case TIOCL_SELLOADLUT:
2699 			console_lock();
2700 			ret = sel_loadlut(p);
2701 			console_unlock();
2702 			break;
2703 		case TIOCL_GETSHIFTSTATE:
2704 
2705 	/*
2706 	 * Make it possible to react to Shift+Mousebutton.
2707 	 * Note that 'shift_state' is an undocumented
2708 	 * kernel-internal variable; programs not closely
2709 	 * related to the kernel should not use this.
2710 	 */
2711 			data = vt_get_shift_state();
2712 			ret = put_user(data, p);
2713 			break;
2714 		case TIOCL_GETMOUSEREPORTING:
2715 			console_lock();	/* May be overkill */
2716 			data = mouse_reporting();
2717 			console_unlock();
2718 			ret = put_user(data, p);
2719 			break;
2720 		case TIOCL_SETVESABLANK:
2721 			console_lock();
2722 			ret = set_vesa_blanking(p);
2723 			console_unlock();
2724 			break;
2725 		case TIOCL_GETKMSGREDIRECT:
2726 			data = vt_get_kmsg_redirect();
2727 			ret = put_user(data, p);
2728 			break;
2729 		case TIOCL_SETKMSGREDIRECT:
2730 			if (!capable(CAP_SYS_ADMIN)) {
2731 				ret = -EPERM;
2732 			} else {
2733 				if (get_user(data, p+1))
2734 					ret = -EFAULT;
2735 				else
2736 					vt_kmsg_redirect(data);
2737 			}
2738 			break;
2739 		case TIOCL_GETFGCONSOLE:
2740 			/* No locking needed as this is a transiently
2741 			   correct return anyway if the caller hasn't
2742 			   disabled switching */
2743 			ret = fg_console;
2744 			break;
2745 		case TIOCL_SCROLLCONSOLE:
2746 			if (get_user(lines, (s32 __user *)(p+4))) {
2747 				ret = -EFAULT;
2748 			} else {
2749 				/* Need the console lock here. Note that lots
2750 				   of other calls need fixing before the lock
2751 				   is actually useful ! */
2752 				console_lock();
2753 				scrollfront(vc_cons[fg_console].d, lines);
2754 				console_unlock();
2755 				ret = 0;
2756 			}
2757 			break;
2758 		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
2759 			console_lock();
2760 			ignore_poke = 1;
2761 			do_blank_screen(0);
2762 			console_unlock();
2763 			break;
2764 		case TIOCL_BLANKEDSCREEN:
2765 			ret = console_blanked;
2766 			break;
2767 		default:
2768 			ret = -EINVAL;
2769 			break;
2770 	}
2771 	return ret;
2772 }
2773 
2774 /*
2775  * /dev/ttyN handling
2776  */
2777 
2778 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2779 {
2780 	int	retval;
2781 
2782 	retval = do_con_write(tty, buf, count);
2783 	con_flush_chars(tty);
2784 
2785 	return retval;
2786 }
2787 
2788 static int con_put_char(struct tty_struct *tty, unsigned char ch)
2789 {
2790 	if (in_interrupt())
2791 		return 0;	/* n_r3964 calls put_char() from interrupt context */
2792 	return do_con_write(tty, &ch, 1);
2793 }
2794 
2795 static int con_write_room(struct tty_struct *tty)
2796 {
2797 	if (tty->stopped)
2798 		return 0;
2799 	return 32768;		/* No limit, really; we're not buffering */
2800 }
2801 
2802 static int con_chars_in_buffer(struct tty_struct *tty)
2803 {
2804 	return 0;		/* we're not buffering */
2805 }
2806 
2807 /*
2808  * con_throttle and con_unthrottle are only used for
2809  * paste_selection(), which has to stuff in a large number of
2810  * characters...
2811  */
2812 static void con_throttle(struct tty_struct *tty)
2813 {
2814 }
2815 
2816 static void con_unthrottle(struct tty_struct *tty)
2817 {
2818 	struct vc_data *vc = tty->driver_data;
2819 
2820 	wake_up_interruptible(&vc->paste_wait);
2821 }
2822 
2823 /*
2824  * Turn the Scroll-Lock LED on when the tty is stopped
2825  */
2826 static void con_stop(struct tty_struct *tty)
2827 {
2828 	int console_num;
2829 	if (!tty)
2830 		return;
2831 	console_num = tty->index;
2832 	if (!vc_cons_allocated(console_num))
2833 		return;
2834 	vt_kbd_con_stop(console_num);
2835 }
2836 
2837 /*
2838  * Turn the Scroll-Lock LED off when the console is started
2839  */
2840 static void con_start(struct tty_struct *tty)
2841 {
2842 	int console_num;
2843 	if (!tty)
2844 		return;
2845 	console_num = tty->index;
2846 	if (!vc_cons_allocated(console_num))
2847 		return;
2848 	vt_kbd_con_start(console_num);
2849 }
2850 
2851 static void con_flush_chars(struct tty_struct *tty)
2852 {
2853 	struct vc_data *vc;
2854 
2855 	if (in_interrupt())	/* from flush_to_ldisc */
2856 		return;
2857 
2858 	/* if we race with con_close(), vt may be null */
2859 	console_lock();
2860 	vc = tty->driver_data;
2861 	if (vc)
2862 		set_cursor(vc);
2863 	console_unlock();
2864 }
2865 
2866 /*
2867  * Allocate the console screen memory.
2868  */
2869 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
2870 {
2871 	unsigned int currcons = tty->index;
2872 	struct vc_data *vc;
2873 	int ret;
2874 
2875 	console_lock();
2876 	ret = vc_allocate(currcons);
2877 	if (ret)
2878 		goto unlock;
2879 
2880 	vc = vc_cons[currcons].d;
2881 
2882 	/* Still being freed */
2883 	if (vc->port.tty) {
2884 		ret = -ERESTARTSYS;
2885 		goto unlock;
2886 	}
2887 
2888 	ret = tty_port_install(&vc->port, driver, tty);
2889 	if (ret)
2890 		goto unlock;
2891 
2892 	tty->driver_data = vc;
2893 	vc->port.tty = tty;
2894 
2895 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
2896 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
2897 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
2898 	}
2899 	if (vc->vc_utf)
2900 		tty->termios.c_iflag |= IUTF8;
2901 	else
2902 		tty->termios.c_iflag &= ~IUTF8;
2903 unlock:
2904 	console_unlock();
2905 	return ret;
2906 }
2907 
2908 static int con_open(struct tty_struct *tty, struct file *filp)
2909 {
2910 	/* everything done in install */
2911 	return 0;
2912 }
2913 
2914 
2915 static void con_close(struct tty_struct *tty, struct file *filp)
2916 {
2917 	/* Nothing to do - we defer to shutdown */
2918 }
2919 
2920 static void con_shutdown(struct tty_struct *tty)
2921 {
2922 	struct vc_data *vc = tty->driver_data;
2923 	BUG_ON(vc == NULL);
2924 	console_lock();
2925 	vc->port.tty = NULL;
2926 	console_unlock();
2927 }
2928 
2929 static int default_color           = 7; /* white */
2930 static int default_italic_color    = 2; // green (ASCII)
2931 static int default_underline_color = 3; // cyan (ASCII)
2932 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
2933 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
2934 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
2935 
2936 static void vc_init(struct vc_data *vc, unsigned int rows,
2937 		    unsigned int cols, int do_clear)
2938 {
2939 	int j, k ;
2940 
2941 	vc->vc_cols = cols;
2942 	vc->vc_rows = rows;
2943 	vc->vc_size_row = cols << 1;
2944 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
2945 
2946 	set_origin(vc);
2947 	vc->vc_pos = vc->vc_origin;
2948 	reset_vc(vc);
2949 	for (j=k=0; j<16; j++) {
2950 		vc->vc_palette[k++] = default_red[j] ;
2951 		vc->vc_palette[k++] = default_grn[j] ;
2952 		vc->vc_palette[k++] = default_blu[j] ;
2953 	}
2954 	vc->vc_def_color       = default_color;
2955 	vc->vc_ulcolor         = default_underline_color;
2956 	vc->vc_itcolor         = default_italic_color;
2957 	vc->vc_halfcolor       = 0x08;   /* grey */
2958 	init_waitqueue_head(&vc->paste_wait);
2959 	reset_terminal(vc, do_clear);
2960 }
2961 
2962 /*
2963  * This routine initializes console interrupts, and does nothing
2964  * else. If you want the screen to clear, call tty_write with
2965  * the appropriate escape-sequence.
2966  */
2967 
2968 static int __init con_init(void)
2969 {
2970 	const char *display_desc = NULL;
2971 	struct vc_data *vc;
2972 	unsigned int currcons = 0, i;
2973 
2974 	console_lock();
2975 
2976 	if (conswitchp)
2977 		display_desc = conswitchp->con_startup();
2978 	if (!display_desc) {
2979 		fg_console = 0;
2980 		console_unlock();
2981 		return 0;
2982 	}
2983 
2984 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
2985 		struct con_driver *con_driver = &registered_con_driver[i];
2986 
2987 		if (con_driver->con == NULL) {
2988 			con_driver->con = conswitchp;
2989 			con_driver->desc = display_desc;
2990 			con_driver->flag = CON_DRIVER_FLAG_INIT;
2991 			con_driver->first = 0;
2992 			con_driver->last = MAX_NR_CONSOLES - 1;
2993 			break;
2994 		}
2995 	}
2996 
2997 	for (i = 0; i < MAX_NR_CONSOLES; i++)
2998 		con_driver_map[i] = conswitchp;
2999 
3000 	if (blankinterval) {
3001 		blank_state = blank_normal_wait;
3002 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3003 	}
3004 
3005 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3006 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3007 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3008 		tty_port_init(&vc->port);
3009 		visual_init(vc, currcons, 1);
3010 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3011 		vc_init(vc, vc->vc_rows, vc->vc_cols,
3012 			currcons || !vc->vc_sw->con_save_screen);
3013 	}
3014 	currcons = fg_console = 0;
3015 	master_display_fg = vc = vc_cons[currcons].d;
3016 	set_origin(vc);
3017 	save_screen(vc);
3018 	gotoxy(vc, vc->vc_x, vc->vc_y);
3019 	csi_J(vc, 0);
3020 	update_screen(vc);
3021 	pr_info("Console: %s %s %dx%d\n",
3022 		vc->vc_can_do_color ? "colour" : "mono",
3023 		display_desc, vc->vc_cols, vc->vc_rows);
3024 	printable = 1;
3025 
3026 	console_unlock();
3027 
3028 #ifdef CONFIG_VT_CONSOLE
3029 	register_console(&vt_console_driver);
3030 #endif
3031 	return 0;
3032 }
3033 console_initcall(con_init);
3034 
3035 static const struct tty_operations con_ops = {
3036 	.install = con_install,
3037 	.open = con_open,
3038 	.close = con_close,
3039 	.write = con_write,
3040 	.write_room = con_write_room,
3041 	.put_char = con_put_char,
3042 	.flush_chars = con_flush_chars,
3043 	.chars_in_buffer = con_chars_in_buffer,
3044 	.ioctl = vt_ioctl,
3045 #ifdef CONFIG_COMPAT
3046 	.compat_ioctl = vt_compat_ioctl,
3047 #endif
3048 	.stop = con_stop,
3049 	.start = con_start,
3050 	.throttle = con_throttle,
3051 	.unthrottle = con_unthrottle,
3052 	.resize = vt_resize,
3053 	.shutdown = con_shutdown
3054 };
3055 
3056 static struct cdev vc0_cdev;
3057 
3058 static ssize_t show_tty_active(struct device *dev,
3059 				struct device_attribute *attr, char *buf)
3060 {
3061 	return sprintf(buf, "tty%d\n", fg_console + 1);
3062 }
3063 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3064 
3065 static struct attribute *vt_dev_attrs[] = {
3066 	&dev_attr_active.attr,
3067 	NULL
3068 };
3069 
3070 ATTRIBUTE_GROUPS(vt_dev);
3071 
3072 int __init vty_init(const struct file_operations *console_fops)
3073 {
3074 	cdev_init(&vc0_cdev, console_fops);
3075 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3076 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3077 		panic("Couldn't register /dev/tty0 driver\n");
3078 	tty0dev = device_create_with_groups(tty_class, NULL,
3079 					    MKDEV(TTY_MAJOR, 0), NULL,
3080 					    vt_dev_groups, "tty0");
3081 	if (IS_ERR(tty0dev))
3082 		tty0dev = NULL;
3083 
3084 	vcs_init();
3085 
3086 	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3087 	if (!console_driver)
3088 		panic("Couldn't allocate console driver\n");
3089 
3090 	console_driver->name = "tty";
3091 	console_driver->name_base = 1;
3092 	console_driver->major = TTY_MAJOR;
3093 	console_driver->minor_start = 1;
3094 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3095 	console_driver->init_termios = tty_std_termios;
3096 	if (default_utf8)
3097 		console_driver->init_termios.c_iflag |= IUTF8;
3098 	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3099 	tty_set_operations(console_driver, &con_ops);
3100 	if (tty_register_driver(console_driver))
3101 		panic("Couldn't register console driver\n");
3102 	kbd_init();
3103 	console_map_init();
3104 #ifdef CONFIG_MDA_CONSOLE
3105 	mda_console_init();
3106 #endif
3107 	return 0;
3108 }
3109 
3110 #ifndef VT_SINGLE_DRIVER
3111 
3112 static struct class *vtconsole_class;
3113 
3114 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3115 			   int deflt)
3116 {
3117 	struct module *owner = csw->owner;
3118 	const char *desc = NULL;
3119 	struct con_driver *con_driver;
3120 	int i, j = -1, k = -1, retval = -ENODEV;
3121 
3122 	if (!try_module_get(owner))
3123 		return -ENODEV;
3124 
3125 	WARN_CONSOLE_UNLOCKED();
3126 
3127 	/* check if driver is registered */
3128 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3129 		con_driver = &registered_con_driver[i];
3130 
3131 		if (con_driver->con == csw) {
3132 			desc = con_driver->desc;
3133 			retval = 0;
3134 			break;
3135 		}
3136 	}
3137 
3138 	if (retval)
3139 		goto err;
3140 
3141 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3142 		csw->con_startup();
3143 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3144 	}
3145 
3146 	if (deflt) {
3147 		if (conswitchp)
3148 			module_put(conswitchp->owner);
3149 
3150 		__module_get(owner);
3151 		conswitchp = csw;
3152 	}
3153 
3154 	first = max(first, con_driver->first);
3155 	last = min(last, con_driver->last);
3156 
3157 	for (i = first; i <= last; i++) {
3158 		int old_was_color;
3159 		struct vc_data *vc = vc_cons[i].d;
3160 
3161 		if (con_driver_map[i])
3162 			module_put(con_driver_map[i]->owner);
3163 		__module_get(owner);
3164 		con_driver_map[i] = csw;
3165 
3166 		if (!vc || !vc->vc_sw)
3167 			continue;
3168 
3169 		j = i;
3170 
3171 		if (con_is_visible(vc)) {
3172 			k = i;
3173 			save_screen(vc);
3174 		}
3175 
3176 		old_was_color = vc->vc_can_do_color;
3177 		vc->vc_sw->con_deinit(vc);
3178 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3179 		visual_init(vc, i, 0);
3180 		set_origin(vc);
3181 		update_attr(vc);
3182 
3183 		/* If the console changed between mono <-> color, then
3184 		 * the attributes in the screenbuf will be wrong.  The
3185 		 * following resets all attributes to something sane.
3186 		 */
3187 		if (old_was_color != vc->vc_can_do_color)
3188 			clear_buffer_attributes(vc);
3189 	}
3190 
3191 	pr_info("Console: switching ");
3192 	if (!deflt)
3193 		pr_cont("consoles %d-%d ", first + 1, last + 1);
3194 	if (j >= 0) {
3195 		struct vc_data *vc = vc_cons[j].d;
3196 
3197 		pr_cont("to %s %s %dx%d\n",
3198 			vc->vc_can_do_color ? "colour" : "mono",
3199 			desc, vc->vc_cols, vc->vc_rows);
3200 
3201 		if (k >= 0) {
3202 			vc = vc_cons[k].d;
3203 			update_screen(vc);
3204 		}
3205 	} else {
3206 		pr_cont("to %s\n", desc);
3207 	}
3208 
3209 	retval = 0;
3210 err:
3211 	module_put(owner);
3212 	return retval;
3213 };
3214 
3215 
3216 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3217 /* unlocked version of unbind_con_driver() */
3218 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3219 {
3220 	struct module *owner = csw->owner;
3221 	const struct consw *defcsw = NULL;
3222 	struct con_driver *con_driver = NULL, *con_back = NULL;
3223 	int i, retval = -ENODEV;
3224 
3225 	if (!try_module_get(owner))
3226 		return -ENODEV;
3227 
3228 	WARN_CONSOLE_UNLOCKED();
3229 
3230 	/* check if driver is registered and if it is unbindable */
3231 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3232 		con_driver = &registered_con_driver[i];
3233 
3234 		if (con_driver->con == csw &&
3235 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3236 			retval = 0;
3237 			break;
3238 		}
3239 	}
3240 
3241 	if (retval)
3242 		goto err;
3243 
3244 	retval = -ENODEV;
3245 
3246 	/* check if backup driver exists */
3247 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3248 		con_back = &registered_con_driver[i];
3249 
3250 		if (con_back->con && con_back->con != csw) {
3251 			defcsw = con_back->con;
3252 			retval = 0;
3253 			break;
3254 		}
3255 	}
3256 
3257 	if (retval)
3258 		goto err;
3259 
3260 	if (!con_is_bound(csw))
3261 		goto err;
3262 
3263 	first = max(first, con_driver->first);
3264 	last = min(last, con_driver->last);
3265 
3266 	for (i = first; i <= last; i++) {
3267 		if (con_driver_map[i] == csw) {
3268 			module_put(csw->owner);
3269 			con_driver_map[i] = NULL;
3270 		}
3271 	}
3272 
3273 	if (!con_is_bound(defcsw)) {
3274 		const struct consw *defconsw = conswitchp;
3275 
3276 		defcsw->con_startup();
3277 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3278 		/*
3279 		 * vgacon may change the default driver to point
3280 		 * to dummycon, we restore it here...
3281 		 */
3282 		conswitchp = defconsw;
3283 	}
3284 
3285 	if (!con_is_bound(csw))
3286 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3287 
3288 	/* ignore return value, binding should not fail */
3289 	do_bind_con_driver(defcsw, first, last, deflt);
3290 err:
3291 	module_put(owner);
3292 	return retval;
3293 
3294 }
3295 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3296 
3297 static int vt_bind(struct con_driver *con)
3298 {
3299 	const struct consw *defcsw = NULL, *csw = NULL;
3300 	int i, more = 1, first = -1, last = -1, deflt = 0;
3301 
3302  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3303 		goto err;
3304 
3305 	csw = con->con;
3306 
3307 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3308 		struct con_driver *con = &registered_con_driver[i];
3309 
3310 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3311 			defcsw = con->con;
3312 			break;
3313 		}
3314 	}
3315 
3316 	if (!defcsw)
3317 		goto err;
3318 
3319 	while (more) {
3320 		more = 0;
3321 
3322 		for (i = con->first; i <= con->last; i++) {
3323 			if (con_driver_map[i] == defcsw) {
3324 				if (first == -1)
3325 					first = i;
3326 				last = i;
3327 				more = 1;
3328 			} else if (first != -1)
3329 				break;
3330 		}
3331 
3332 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3333 			deflt = 1;
3334 
3335 		if (first != -1)
3336 			do_bind_con_driver(csw, first, last, deflt);
3337 
3338 		first = -1;
3339 		last = -1;
3340 		deflt = 0;
3341 	}
3342 
3343 err:
3344 	return 0;
3345 }
3346 
3347 static int vt_unbind(struct con_driver *con)
3348 {
3349 	const struct consw *csw = NULL;
3350 	int i, more = 1, first = -1, last = -1, deflt = 0;
3351 	int ret;
3352 
3353  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3354 		goto err;
3355 
3356 	csw = con->con;
3357 
3358 	while (more) {
3359 		more = 0;
3360 
3361 		for (i = con->first; i <= con->last; i++) {
3362 			if (con_driver_map[i] == csw) {
3363 				if (first == -1)
3364 					first = i;
3365 				last = i;
3366 				more = 1;
3367 			} else if (first != -1)
3368 				break;
3369 		}
3370 
3371 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3372 			deflt = 1;
3373 
3374 		if (first != -1) {
3375 			ret = do_unbind_con_driver(csw, first, last, deflt);
3376 			if (ret != 0)
3377 				return ret;
3378 		}
3379 
3380 		first = -1;
3381 		last = -1;
3382 		deflt = 0;
3383 	}
3384 
3385 err:
3386 	return 0;
3387 }
3388 #else
3389 static inline int vt_bind(struct con_driver *con)
3390 {
3391 	return 0;
3392 }
3393 static inline int vt_unbind(struct con_driver *con)
3394 {
3395 	return 0;
3396 }
3397 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3398 
3399 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3400 			  const char *buf, size_t count)
3401 {
3402 	struct con_driver *con = dev_get_drvdata(dev);
3403 	int bind = simple_strtoul(buf, NULL, 0);
3404 
3405 	console_lock();
3406 
3407 	if (bind)
3408 		vt_bind(con);
3409 	else
3410 		vt_unbind(con);
3411 
3412 	console_unlock();
3413 
3414 	return count;
3415 }
3416 
3417 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3418 			 char *buf)
3419 {
3420 	struct con_driver *con = dev_get_drvdata(dev);
3421 	int bind = con_is_bound(con->con);
3422 
3423 	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3424 }
3425 
3426 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3427 			 char *buf)
3428 {
3429 	struct con_driver *con = dev_get_drvdata(dev);
3430 
3431 	return snprintf(buf, PAGE_SIZE, "%s %s\n",
3432 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3433 			 con->desc);
3434 
3435 }
3436 
3437 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3438 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3439 
3440 static struct attribute *con_dev_attrs[] = {
3441 	&dev_attr_bind.attr,
3442 	&dev_attr_name.attr,
3443 	NULL
3444 };
3445 
3446 ATTRIBUTE_GROUPS(con_dev);
3447 
3448 static int vtconsole_init_device(struct con_driver *con)
3449 {
3450 	con->flag |= CON_DRIVER_FLAG_ATTR;
3451 	return 0;
3452 }
3453 
3454 static void vtconsole_deinit_device(struct con_driver *con)
3455 {
3456 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3457 }
3458 
3459 /**
3460  * con_is_bound - checks if driver is bound to the console
3461  * @csw: console driver
3462  *
3463  * RETURNS: zero if unbound, nonzero if bound
3464  *
3465  * Drivers can call this and if zero, they should release
3466  * all resources allocated on con_startup()
3467  */
3468 int con_is_bound(const struct consw *csw)
3469 {
3470 	int i, bound = 0;
3471 
3472 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3473 		if (con_driver_map[i] == csw) {
3474 			bound = 1;
3475 			break;
3476 		}
3477 	}
3478 
3479 	return bound;
3480 }
3481 EXPORT_SYMBOL(con_is_bound);
3482 
3483 /**
3484  * con_debug_enter - prepare the console for the kernel debugger
3485  * @sw: console driver
3486  *
3487  * Called when the console is taken over by the kernel debugger, this
3488  * function needs to save the current console state, then put the console
3489  * into a state suitable for the kernel debugger.
3490  *
3491  * RETURNS:
3492  * Zero on success, nonzero if a failure occurred when trying to prepare
3493  * the console for the debugger.
3494  */
3495 int con_debug_enter(struct vc_data *vc)
3496 {
3497 	int ret = 0;
3498 
3499 	saved_fg_console = fg_console;
3500 	saved_last_console = last_console;
3501 	saved_want_console = want_console;
3502 	saved_vc_mode = vc->vc_mode;
3503 	saved_console_blanked = console_blanked;
3504 	vc->vc_mode = KD_TEXT;
3505 	console_blanked = 0;
3506 	if (vc->vc_sw->con_debug_enter)
3507 		ret = vc->vc_sw->con_debug_enter(vc);
3508 #ifdef CONFIG_KGDB_KDB
3509 	/* Set the initial LINES variable if it is not already set */
3510 	if (vc->vc_rows < 999) {
3511 		int linecount;
3512 		char lns[4];
3513 		const char *setargs[3] = {
3514 			"set",
3515 			"LINES",
3516 			lns,
3517 		};
3518 		if (kdbgetintenv(setargs[0], &linecount)) {
3519 			snprintf(lns, 4, "%i", vc->vc_rows);
3520 			kdb_set(2, setargs);
3521 		}
3522 	}
3523 	if (vc->vc_cols < 999) {
3524 		int colcount;
3525 		char cols[4];
3526 		const char *setargs[3] = {
3527 			"set",
3528 			"COLUMNS",
3529 			cols,
3530 		};
3531 		if (kdbgetintenv(setargs[0], &colcount)) {
3532 			snprintf(cols, 4, "%i", vc->vc_cols);
3533 			kdb_set(2, setargs);
3534 		}
3535 	}
3536 #endif /* CONFIG_KGDB_KDB */
3537 	return ret;
3538 }
3539 EXPORT_SYMBOL_GPL(con_debug_enter);
3540 
3541 /**
3542  * con_debug_leave - restore console state
3543  * @sw: console driver
3544  *
3545  * Restore the console state to what it was before the kernel debugger
3546  * was invoked.
3547  *
3548  * RETURNS:
3549  * Zero on success, nonzero if a failure occurred when trying to restore
3550  * the console.
3551  */
3552 int con_debug_leave(void)
3553 {
3554 	struct vc_data *vc;
3555 	int ret = 0;
3556 
3557 	fg_console = saved_fg_console;
3558 	last_console = saved_last_console;
3559 	want_console = saved_want_console;
3560 	console_blanked = saved_console_blanked;
3561 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3562 
3563 	vc = vc_cons[fg_console].d;
3564 	if (vc->vc_sw->con_debug_leave)
3565 		ret = vc->vc_sw->con_debug_leave(vc);
3566 	return ret;
3567 }
3568 EXPORT_SYMBOL_GPL(con_debug_leave);
3569 
3570 static int do_register_con_driver(const struct consw *csw, int first, int last)
3571 {
3572 	struct module *owner = csw->owner;
3573 	struct con_driver *con_driver;
3574 	const char *desc;
3575 	int i, retval;
3576 
3577 	WARN_CONSOLE_UNLOCKED();
3578 
3579 	if (!try_module_get(owner))
3580 		return -ENODEV;
3581 
3582 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3583 		con_driver = &registered_con_driver[i];
3584 
3585 		/* already registered */
3586 		if (con_driver->con == csw) {
3587 			retval = -EBUSY;
3588 			goto err;
3589 		}
3590 	}
3591 
3592 	desc = csw->con_startup();
3593 	if (!desc) {
3594 		retval = -ENODEV;
3595 		goto err;
3596 	}
3597 
3598 	retval = -EINVAL;
3599 
3600 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3601 		con_driver = &registered_con_driver[i];
3602 
3603 		if (con_driver->con == NULL &&
3604 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3605 			con_driver->con = csw;
3606 			con_driver->desc = desc;
3607 			con_driver->node = i;
3608 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
3609 			                   CON_DRIVER_FLAG_INIT;
3610 			con_driver->first = first;
3611 			con_driver->last = last;
3612 			retval = 0;
3613 			break;
3614 		}
3615 	}
3616 
3617 	if (retval)
3618 		goto err;
3619 
3620 	con_driver->dev =
3621 		device_create_with_groups(vtconsole_class, NULL,
3622 					  MKDEV(0, con_driver->node),
3623 					  con_driver, con_dev_groups,
3624 					  "vtcon%i", con_driver->node);
3625 	if (IS_ERR(con_driver->dev)) {
3626 		pr_warn("Unable to create device for %s; errno = %ld\n",
3627 			con_driver->desc, PTR_ERR(con_driver->dev));
3628 		con_driver->dev = NULL;
3629 	} else {
3630 		vtconsole_init_device(con_driver);
3631 	}
3632 
3633 err:
3634 	module_put(owner);
3635 	return retval;
3636 }
3637 
3638 
3639 /**
3640  * do_unregister_con_driver - unregister console driver from console layer
3641  * @csw: console driver
3642  *
3643  * DESCRIPTION: All drivers that registers to the console layer must
3644  * call this function upon exit, or if the console driver is in a state
3645  * where it won't be able to handle console services, such as the
3646  * framebuffer console without loaded framebuffer drivers.
3647  *
3648  * The driver must unbind first prior to unregistration.
3649  */
3650 int do_unregister_con_driver(const struct consw *csw)
3651 {
3652 	int i;
3653 
3654 	/* cannot unregister a bound driver */
3655 	if (con_is_bound(csw))
3656 		return -EBUSY;
3657 
3658 	if (csw == conswitchp)
3659 		return -EINVAL;
3660 
3661 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3662 		struct con_driver *con_driver = &registered_con_driver[i];
3663 
3664 		if (con_driver->con == csw) {
3665 			/*
3666 			 * Defer the removal of the sysfs entries since that
3667 			 * will acquire the kernfs s_active lock and we can't
3668 			 * acquire this lock while holding the console lock:
3669 			 * the unbind sysfs entry imposes already the opposite
3670 			 * order. Reset con already here to prevent any later
3671 			 * lookup to succeed and mark this slot as zombie, so
3672 			 * it won't get reused until we complete the removal
3673 			 * in the deferred work.
3674 			 */
3675 			con_driver->con = NULL;
3676 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
3677 			schedule_work(&con_driver_unregister_work);
3678 
3679 			return 0;
3680 		}
3681 	}
3682 
3683 	return -ENODEV;
3684 }
3685 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
3686 
3687 static void con_driver_unregister_callback(struct work_struct *ignored)
3688 {
3689 	int i;
3690 
3691 	console_lock();
3692 
3693 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3694 		struct con_driver *con_driver = &registered_con_driver[i];
3695 
3696 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
3697 			continue;
3698 
3699 		console_unlock();
3700 
3701 		vtconsole_deinit_device(con_driver);
3702 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
3703 
3704 		console_lock();
3705 
3706 		if (WARN_ON_ONCE(con_driver->con))
3707 			con_driver->con = NULL;
3708 		con_driver->desc = NULL;
3709 		con_driver->dev = NULL;
3710 		con_driver->node = 0;
3711 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
3712 		con_driver->flag = 0;
3713 		con_driver->first = 0;
3714 		con_driver->last = 0;
3715 	}
3716 
3717 	console_unlock();
3718 }
3719 
3720 /*
3721  *	If we support more console drivers, this function is used
3722  *	when a driver wants to take over some existing consoles
3723  *	and become default driver for newly opened ones.
3724  *
3725  *	do_take_over_console is basically a register followed by unbind
3726  */
3727 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
3728 {
3729 	int err;
3730 
3731 	err = do_register_con_driver(csw, first, last);
3732 	/*
3733 	 * If we get an busy error we still want to bind the console driver
3734 	 * and return success, as we may have unbound the console driver
3735 	 * but not unregistered it.
3736 	 */
3737 	if (err == -EBUSY)
3738 		err = 0;
3739 	if (!err)
3740 		do_bind_con_driver(csw, first, last, deflt);
3741 
3742 	return err;
3743 }
3744 EXPORT_SYMBOL_GPL(do_take_over_console);
3745 
3746 
3747 /*
3748  * give_up_console is a wrapper to unregister_con_driver. It will only
3749  * work if driver is fully unbound.
3750  */
3751 void give_up_console(const struct consw *csw)
3752 {
3753 	console_lock();
3754 	do_unregister_con_driver(csw);
3755 	console_unlock();
3756 }
3757 
3758 static int __init vtconsole_class_init(void)
3759 {
3760 	int i;
3761 
3762 	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
3763 	if (IS_ERR(vtconsole_class)) {
3764 		pr_warn("Unable to create vt console class; errno = %ld\n",
3765 			PTR_ERR(vtconsole_class));
3766 		vtconsole_class = NULL;
3767 	}
3768 
3769 	/* Add system drivers to sysfs */
3770 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3771 		struct con_driver *con = &registered_con_driver[i];
3772 
3773 		if (con->con && !con->dev) {
3774 			con->dev =
3775 				device_create_with_groups(vtconsole_class, NULL,
3776 							  MKDEV(0, con->node),
3777 							  con, con_dev_groups,
3778 							  "vtcon%i", con->node);
3779 
3780 			if (IS_ERR(con->dev)) {
3781 				pr_warn("Unable to create device for %s; errno = %ld\n",
3782 					con->desc, PTR_ERR(con->dev));
3783 				con->dev = NULL;
3784 			} else {
3785 				vtconsole_init_device(con);
3786 			}
3787 		}
3788 	}
3789 
3790 	return 0;
3791 }
3792 postcore_initcall(vtconsole_class_init);
3793 
3794 #endif
3795 
3796 /*
3797  *	Screen blanking
3798  */
3799 
3800 static int set_vesa_blanking(char __user *p)
3801 {
3802 	unsigned int mode;
3803 
3804 	if (get_user(mode, p + 1))
3805 		return -EFAULT;
3806 
3807 	vesa_blank_mode = (mode < 4) ? mode : 0;
3808 	return 0;
3809 }
3810 
3811 void do_blank_screen(int entering_gfx)
3812 {
3813 	struct vc_data *vc = vc_cons[fg_console].d;
3814 	int i;
3815 
3816 	WARN_CONSOLE_UNLOCKED();
3817 
3818 	if (console_blanked) {
3819 		if (blank_state == blank_vesa_wait) {
3820 			blank_state = blank_off;
3821 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
3822 		}
3823 		return;
3824 	}
3825 
3826 	/* entering graphics mode? */
3827 	if (entering_gfx) {
3828 		hide_cursor(vc);
3829 		save_screen(vc);
3830 		vc->vc_sw->con_blank(vc, -1, 1);
3831 		console_blanked = fg_console + 1;
3832 		blank_state = blank_off;
3833 		set_origin(vc);
3834 		return;
3835 	}
3836 
3837 	if (blank_state != blank_normal_wait)
3838 		return;
3839 	blank_state = blank_off;
3840 
3841 	/* don't blank graphics */
3842 	if (vc->vc_mode != KD_TEXT) {
3843 		console_blanked = fg_console + 1;
3844 		return;
3845 	}
3846 
3847 	hide_cursor(vc);
3848 	del_timer_sync(&console_timer);
3849 	blank_timer_expired = 0;
3850 
3851 	save_screen(vc);
3852 	/* In case we need to reset origin, blanking hook returns 1 */
3853 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
3854 	console_blanked = fg_console + 1;
3855 	if (i)
3856 		set_origin(vc);
3857 
3858 	if (console_blank_hook && console_blank_hook(1))
3859 		return;
3860 
3861 	if (vesa_off_interval && vesa_blank_mode) {
3862 		blank_state = blank_vesa_wait;
3863 		mod_timer(&console_timer, jiffies + vesa_off_interval);
3864 	}
3865 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
3866 }
3867 EXPORT_SYMBOL(do_blank_screen);
3868 
3869 /*
3870  * Called by timer as well as from vt_console_driver
3871  */
3872 void do_unblank_screen(int leaving_gfx)
3873 {
3874 	struct vc_data *vc;
3875 
3876 	/* This should now always be called from a "sane" (read: can schedule)
3877 	 * context for the sake of the low level drivers, except in the special
3878 	 * case of oops_in_progress
3879 	 */
3880 	if (!oops_in_progress)
3881 		might_sleep();
3882 
3883 	WARN_CONSOLE_UNLOCKED();
3884 
3885 	ignore_poke = 0;
3886 	if (!console_blanked)
3887 		return;
3888 	if (!vc_cons_allocated(fg_console)) {
3889 		/* impossible */
3890 		pr_warn("unblank_screen: tty %d not allocated ??\n",
3891 			fg_console + 1);
3892 		return;
3893 	}
3894 	vc = vc_cons[fg_console].d;
3895 	/* Try to unblank in oops case too */
3896 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
3897 		return; /* but leave console_blanked != 0 */
3898 
3899 	if (blankinterval) {
3900 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3901 		blank_state = blank_normal_wait;
3902 	}
3903 
3904 	console_blanked = 0;
3905 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
3906 		/* Low-level driver cannot restore -> do it ourselves */
3907 		update_screen(vc);
3908 	if (console_blank_hook)
3909 		console_blank_hook(0);
3910 	set_palette(vc);
3911 	set_cursor(vc);
3912 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
3913 }
3914 EXPORT_SYMBOL(do_unblank_screen);
3915 
3916 /*
3917  * This is called by the outside world to cause a forced unblank, mostly for
3918  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
3919  * call it with 1 as an argument and so force a mode restore... that may kill
3920  * X or at least garbage the screen but would also make the Oops visible...
3921  */
3922 void unblank_screen(void)
3923 {
3924 	do_unblank_screen(0);
3925 }
3926 
3927 /*
3928  * We defer the timer blanking to work queue so it can take the console mutex
3929  * (console operations can still happen at irq time, but only from printk which
3930  * has the console mutex. Not perfect yet, but better than no locking
3931  */
3932 static void blank_screen_t(struct timer_list *unused)
3933 {
3934 	blank_timer_expired = 1;
3935 	schedule_work(&console_work);
3936 }
3937 
3938 void poke_blanked_console(void)
3939 {
3940 	WARN_CONSOLE_UNLOCKED();
3941 
3942 	/* Add this so we quickly catch whoever might call us in a non
3943 	 * safe context. Nowadays, unblank_screen() isn't to be called in
3944 	 * atomic contexts and is allowed to schedule (with the special case
3945 	 * of oops_in_progress, but that isn't of any concern for this
3946 	 * function. --BenH.
3947 	 */
3948 	might_sleep();
3949 
3950 	/* This isn't perfectly race free, but a race here would be mostly harmless,
3951 	 * at worse, we'll do a spurrious blank and it's unlikely
3952 	 */
3953 	del_timer(&console_timer);
3954 	blank_timer_expired = 0;
3955 
3956 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
3957 		return;
3958 	if (console_blanked)
3959 		unblank_screen();
3960 	else if (blankinterval) {
3961 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3962 		blank_state = blank_normal_wait;
3963 	}
3964 }
3965 
3966 /*
3967  *	Palettes
3968  */
3969 
3970 static void set_palette(struct vc_data *vc)
3971 {
3972 	WARN_CONSOLE_UNLOCKED();
3973 
3974 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
3975 		vc->vc_sw->con_set_palette(vc, color_table);
3976 }
3977 
3978 /*
3979  * Load palette into the DAC registers. arg points to a colour
3980  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
3981  */
3982 
3983 int con_set_cmap(unsigned char __user *arg)
3984 {
3985 	int i, j, k;
3986 	unsigned char colormap[3*16];
3987 
3988 	if (copy_from_user(colormap, arg, sizeof(colormap)))
3989 		return -EFAULT;
3990 
3991 	console_lock();
3992 	for (i = k = 0; i < 16; i++) {
3993 		default_red[i] = colormap[k++];
3994 		default_grn[i] = colormap[k++];
3995 		default_blu[i] = colormap[k++];
3996 	}
3997 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3998 		if (!vc_cons_allocated(i))
3999 			continue;
4000 		for (j = k = 0; j < 16; j++) {
4001 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4002 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4003 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4004 		}
4005 		set_palette(vc_cons[i].d);
4006 	}
4007 	console_unlock();
4008 
4009 	return 0;
4010 }
4011 
4012 int con_get_cmap(unsigned char __user *arg)
4013 {
4014 	int i, k;
4015 	unsigned char colormap[3*16];
4016 
4017 	console_lock();
4018 	for (i = k = 0; i < 16; i++) {
4019 		colormap[k++] = default_red[i];
4020 		colormap[k++] = default_grn[i];
4021 		colormap[k++] = default_blu[i];
4022 	}
4023 	console_unlock();
4024 
4025 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4026 		return -EFAULT;
4027 
4028 	return 0;
4029 }
4030 
4031 void reset_palette(struct vc_data *vc)
4032 {
4033 	int j, k;
4034 	for (j=k=0; j<16; j++) {
4035 		vc->vc_palette[k++] = default_red[j];
4036 		vc->vc_palette[k++] = default_grn[j];
4037 		vc->vc_palette[k++] = default_blu[j];
4038 	}
4039 	set_palette(vc);
4040 }
4041 
4042 /*
4043  *  Font switching
4044  *
4045  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4046  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4047  *  depending on width) reserved for each character which is kinda wasty, but
4048  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4049  *  is up to the actual low-level console-driver convert data into its favorite
4050  *  format (maybe we should add a `fontoffset' field to the `display'
4051  *  structure so we won't have to convert the fontdata all the time.
4052  *  /Jes
4053  */
4054 
4055 #define max_font_size 65536
4056 
4057 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4058 {
4059 	struct console_font font;
4060 	int rc = -EINVAL;
4061 	int c;
4062 
4063 	if (op->data) {
4064 		font.data = kmalloc(max_font_size, GFP_KERNEL);
4065 		if (!font.data)
4066 			return -ENOMEM;
4067 	} else
4068 		font.data = NULL;
4069 
4070 	console_lock();
4071 	if (vc->vc_mode != KD_TEXT)
4072 		rc = -EINVAL;
4073 	else if (vc->vc_sw->con_font_get)
4074 		rc = vc->vc_sw->con_font_get(vc, &font);
4075 	else
4076 		rc = -ENOSYS;
4077 	console_unlock();
4078 
4079 	if (rc)
4080 		goto out;
4081 
4082 	c = (font.width+7)/8 * 32 * font.charcount;
4083 
4084 	if (op->data && font.charcount > op->charcount)
4085 		rc = -ENOSPC;
4086 	if (!(op->flags & KD_FONT_FLAG_OLD)) {
4087 		if (font.width > op->width || font.height > op->height)
4088 			rc = -ENOSPC;
4089 	} else {
4090 		if (font.width != 8)
4091 			rc = -EIO;
4092 		else if ((op->height && font.height > op->height) ||
4093 			 font.height > 32)
4094 			rc = -ENOSPC;
4095 	}
4096 	if (rc)
4097 		goto out;
4098 
4099 	op->height = font.height;
4100 	op->width = font.width;
4101 	op->charcount = font.charcount;
4102 
4103 	if (op->data && copy_to_user(op->data, font.data, c))
4104 		rc = -EFAULT;
4105 
4106 out:
4107 	kfree(font.data);
4108 	return rc;
4109 }
4110 
4111 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4112 {
4113 	struct console_font font;
4114 	int rc = -EINVAL;
4115 	int size;
4116 
4117 	if (vc->vc_mode != KD_TEXT)
4118 		return -EINVAL;
4119 	if (!op->data)
4120 		return -EINVAL;
4121 	if (op->charcount > 512)
4122 		return -EINVAL;
4123 	if (op->width <= 0 || op->width > 32 || op->height > 32)
4124 		return -EINVAL;
4125 	size = (op->width+7)/8 * 32 * op->charcount;
4126 	if (size > max_font_size)
4127 		return -ENOSPC;
4128 
4129 	font.data = memdup_user(op->data, size);
4130 	if (IS_ERR(font.data))
4131 		return PTR_ERR(font.data);
4132 
4133 	if (!op->height) {		/* Need to guess font height [compat] */
4134 		int h, i;
4135 		u8 *charmap = font.data;
4136 
4137 		/*
4138 		 * If from KDFONTOP ioctl, don't allow things which can be done
4139 		 * in userland,so that we can get rid of this soon
4140 		 */
4141 		if (!(op->flags & KD_FONT_FLAG_OLD)) {
4142 			kfree(font.data);
4143 			return -EINVAL;
4144 		}
4145 
4146 		for (h = 32; h > 0; h--)
4147 			for (i = 0; i < op->charcount; i++)
4148 				if (charmap[32*i+h-1])
4149 					goto nonzero;
4150 
4151 		kfree(font.data);
4152 		return -EINVAL;
4153 
4154 	nonzero:
4155 		op->height = h;
4156 	}
4157 
4158 	font.charcount = op->charcount;
4159 	font.width = op->width;
4160 	font.height = op->height;
4161 
4162 	console_lock();
4163 	if (vc->vc_mode != KD_TEXT)
4164 		rc = -EINVAL;
4165 	else if (vc->vc_sw->con_font_set)
4166 		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4167 	else
4168 		rc = -ENOSYS;
4169 	console_unlock();
4170 	kfree(font.data);
4171 	return rc;
4172 }
4173 
4174 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4175 {
4176 	struct console_font font = {.width = op->width, .height = op->height};
4177 	char name[MAX_FONT_NAME];
4178 	char *s = name;
4179 	int rc;
4180 
4181 
4182 	if (!op->data)
4183 		s = NULL;
4184 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4185 		return -EFAULT;
4186 	else
4187 		name[MAX_FONT_NAME - 1] = 0;
4188 
4189 	console_lock();
4190 	if (vc->vc_mode != KD_TEXT) {
4191 		console_unlock();
4192 		return -EINVAL;
4193 	}
4194 	if (vc->vc_sw->con_font_default)
4195 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4196 	else
4197 		rc = -ENOSYS;
4198 	console_unlock();
4199 	if (!rc) {
4200 		op->width = font.width;
4201 		op->height = font.height;
4202 	}
4203 	return rc;
4204 }
4205 
4206 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4207 {
4208 	int con = op->height;
4209 	int rc;
4210 
4211 
4212 	console_lock();
4213 	if (vc->vc_mode != KD_TEXT)
4214 		rc = -EINVAL;
4215 	else if (!vc->vc_sw->con_font_copy)
4216 		rc = -ENOSYS;
4217 	else if (con < 0 || !vc_cons_allocated(con))
4218 		rc = -ENOTTY;
4219 	else if (con == vc->vc_num)	/* nothing to do */
4220 		rc = 0;
4221 	else
4222 		rc = vc->vc_sw->con_font_copy(vc, con);
4223 	console_unlock();
4224 	return rc;
4225 }
4226 
4227 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4228 {
4229 	switch (op->op) {
4230 	case KD_FONT_OP_SET:
4231 		return con_font_set(vc, op);
4232 	case KD_FONT_OP_GET:
4233 		return con_font_get(vc, op);
4234 	case KD_FONT_OP_SET_DEFAULT:
4235 		return con_font_default(vc, op);
4236 	case KD_FONT_OP_COPY:
4237 		return con_font_copy(vc, op);
4238 	}
4239 	return -ENOSYS;
4240 }
4241 
4242 /*
4243  *	Interface exported to selection and vcs.
4244  */
4245 
4246 /* used by selection */
4247 u16 screen_glyph(struct vc_data *vc, int offset)
4248 {
4249 	u16 w = scr_readw(screenpos(vc, offset, 1));
4250 	u16 c = w & 0xff;
4251 
4252 	if (w & vc->vc_hi_font_mask)
4253 		c |= 0x100;
4254 	return c;
4255 }
4256 EXPORT_SYMBOL_GPL(screen_glyph);
4257 
4258 /* used by vcs - note the word offset */
4259 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4260 {
4261 	return screenpos(vc, 2 * w_offset, viewed);
4262 }
4263 EXPORT_SYMBOL_GPL(screen_pos);
4264 
4265 void getconsxy(struct vc_data *vc, unsigned char *p)
4266 {
4267 	p[0] = vc->vc_x;
4268 	p[1] = vc->vc_y;
4269 }
4270 
4271 void putconsxy(struct vc_data *vc, unsigned char *p)
4272 {
4273 	hide_cursor(vc);
4274 	gotoxy(vc, p[0], p[1]);
4275 	set_cursor(vc);
4276 }
4277 
4278 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4279 {
4280 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4281 		return softcursor_original;
4282 	return scr_readw(org);
4283 }
4284 
4285 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4286 {
4287 	scr_writew(val, org);
4288 	if ((unsigned long)org == vc->vc_pos) {
4289 		softcursor_original = -1;
4290 		add_softcursor(vc);
4291 	}
4292 }
4293 
4294 void vcs_scr_updated(struct vc_data *vc)
4295 {
4296 	notify_update(vc);
4297 }
4298 
4299 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4300 		unsigned int rolled_over, void *base, unsigned int size)
4301 {
4302 	unsigned long ubase = (unsigned long)base;
4303 	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4304 	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4305 	ptrdiff_t origin = (void *)c->vc_origin - base;
4306 	int margin = c->vc_size_row * 4;
4307 	int from, wrap, from_off, avail;
4308 
4309 	/* Turn scrollback off */
4310 	if (!lines) {
4311 		c->vc_visible_origin = c->vc_origin;
4312 		return;
4313 	}
4314 
4315 	/* Do we have already enough to allow jumping from 0 to the end? */
4316 	if (rolled_over > scr_end + margin) {
4317 		from = scr_end;
4318 		wrap = rolled_over + c->vc_size_row;
4319 	} else {
4320 		from = 0;
4321 		wrap = size;
4322 	}
4323 
4324 	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4325 	avail = (origin - from + wrap) % wrap;
4326 
4327 	/* Only a little piece would be left? Show all incl. the piece! */
4328 	if (avail < 2 * margin)
4329 		margin = 0;
4330 	if (from_off < margin)
4331 		from_off = 0;
4332 	if (from_off > avail - margin)
4333 		from_off = avail;
4334 
4335 	c->vc_visible_origin = ubase + (from + from_off) % wrap;
4336 }
4337 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4338 
4339 /*
4340  *	Visible symbols for modules
4341  */
4342 
4343 EXPORT_SYMBOL(color_table);
4344 EXPORT_SYMBOL(default_red);
4345 EXPORT_SYMBOL(default_grn);
4346 EXPORT_SYMBOL(default_blu);
4347 EXPORT_SYMBOL(update_region);
4348 EXPORT_SYMBOL(redraw_screen);
4349 EXPORT_SYMBOL(vc_resize);
4350 EXPORT_SYMBOL(fg_console);
4351 EXPORT_SYMBOL(console_blank_hook);
4352 EXPORT_SYMBOL(console_blanked);
4353 EXPORT_SYMBOL(vc_cons);
4354 EXPORT_SYMBOL(global_cursor_default);
4355 #ifndef VT_SINGLE_DRIVER
4356 EXPORT_SYMBOL(give_up_console);
4357 #endif
4358