xref: /linux/drivers/tty/vt/vt.c (revision 17b121ad0c43342bc894632f6710b894849ca372)
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/vmalloc.h>
85 #include <linux/major.h>
86 #include <linux/mm.h>
87 #include <linux/console.h>
88 #include <linux/init.h>
89 #include <linux/mutex.h>
90 #include <linux/vt_kern.h>
91 #include <linux/selection.h>
92 #include <linux/tiocl.h>
93 #include <linux/kbd_kern.h>
94 #include <linux/consolemap.h>
95 #include <linux/timer.h>
96 #include <linux/interrupt.h>
97 #include <linux/workqueue.h>
98 #include <linux/pm.h>
99 #include <linux/font.h>
100 #include <linux/bitops.h>
101 #include <linux/notifier.h>
102 #include <linux/device.h>
103 #include <linux/io.h>
104 #include <linux/uaccess.h>
105 #include <linux/kdb.h>
106 #include <linux/ctype.h>
107 #include <linux/bsearch.h>
108 #include <linux/gcd.h>
109 
110 #define MAX_NR_CON_DRIVER 16
111 
112 #define CON_DRIVER_FLAG_MODULE 1
113 #define CON_DRIVER_FLAG_INIT   2
114 #define CON_DRIVER_FLAG_ATTR   4
115 #define CON_DRIVER_FLAG_ZOMBIE 8
116 
117 struct con_driver {
118 	const struct consw *con;
119 	const char *desc;
120 	struct device *dev;
121 	int node;
122 	int first;
123 	int last;
124 	int flag;
125 };
126 
127 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
128 const struct consw *conswitchp;
129 
130 /*
131  * Here is the default bell parameters: 750HZ, 1/8th of a second
132  */
133 #define DEFAULT_BELL_PITCH	750
134 #define DEFAULT_BELL_DURATION	(HZ/8)
135 #define DEFAULT_CURSOR_BLINK_MS	200
136 
137 struct vc vc_cons [MAX_NR_CONSOLES];
138 
139 #ifndef VT_SINGLE_DRIVER
140 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
141 #endif
142 
143 static int con_open(struct tty_struct *, struct file *);
144 static void vc_init(struct vc_data *vc, unsigned int rows,
145 		    unsigned int cols, int do_clear);
146 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
147 static void save_cur(struct vc_data *vc);
148 static void reset_terminal(struct vc_data *vc, int do_clear);
149 static void con_flush_chars(struct tty_struct *tty);
150 static int set_vesa_blanking(char __user *p);
151 static void set_cursor(struct vc_data *vc);
152 static void hide_cursor(struct vc_data *vc);
153 static void console_callback(struct work_struct *ignored);
154 static void con_driver_unregister_callback(struct work_struct *ignored);
155 static void blank_screen_t(struct timer_list *unused);
156 static void set_palette(struct vc_data *vc);
157 
158 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
159 
160 static int printable;		/* Is console ready for printing? */
161 int default_utf8 = true;
162 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
163 int global_cursor_default = -1;
164 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
165 
166 static int cur_default = CUR_UNDERLINE;
167 module_param(cur_default, int, S_IRUGO | S_IWUSR);
168 
169 /*
170  * ignore_poke: don't unblank the screen when things are typed.  This is
171  * mainly for the privacy of braille terminal users.
172  */
173 static int ignore_poke;
174 
175 int do_poke_blanked_console;
176 int console_blanked;
177 
178 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
179 static int vesa_off_interval;
180 static int blankinterval;
181 core_param(consoleblank, blankinterval, int, 0444);
182 
183 static DECLARE_WORK(console_work, console_callback);
184 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
185 
186 /*
187  * fg_console is the current virtual console,
188  * last_console is the last used one,
189  * want_console is the console we want to switch to,
190  * saved_* variants are for save/restore around kernel debugger enter/leave
191  */
192 int fg_console;
193 int last_console;
194 int want_console = -1;
195 static int saved_fg_console;
196 static int saved_last_console;
197 static int saved_want_console;
198 static int saved_vc_mode;
199 static int saved_console_blanked;
200 
201 /*
202  * For each existing display, we have a pointer to console currently visible
203  * on that display, allowing consoles other than fg_console to be refreshed
204  * appropriately. Unless the low-level driver supplies its own display_fg
205  * variable, we use this one for the "master display".
206  */
207 static struct vc_data *master_display_fg;
208 
209 /*
210  * Unfortunately, we need to delay tty echo when we're currently writing to the
211  * console since the code is (and always was) not re-entrant, so we schedule
212  * all flip requests to process context with schedule-task() and run it from
213  * console_callback().
214  */
215 
216 /*
217  * For the same reason, we defer scrollback to the console callback.
218  */
219 static int scrollback_delta;
220 
221 /*
222  * Hook so that the power management routines can (un)blank
223  * the console on our behalf.
224  */
225 int (*console_blank_hook)(int);
226 
227 static DEFINE_TIMER(console_timer, blank_screen_t);
228 static int blank_state;
229 static int blank_timer_expired;
230 enum {
231 	blank_off = 0,
232 	blank_normal_wait,
233 	blank_vesa_wait,
234 };
235 
236 /*
237  * /sys/class/tty/tty0/
238  *
239  * the attribute 'active' contains the name of the current vc
240  * console and it supports poll() to detect vc switches
241  */
242 static struct device *tty0dev;
243 
244 /*
245  * Notifier list for console events.
246  */
247 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
248 
249 int register_vt_notifier(struct notifier_block *nb)
250 {
251 	return atomic_notifier_chain_register(&vt_notifier_list, nb);
252 }
253 EXPORT_SYMBOL_GPL(register_vt_notifier);
254 
255 int unregister_vt_notifier(struct notifier_block *nb)
256 {
257 	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
258 }
259 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
260 
261 static void notify_write(struct vc_data *vc, unsigned int unicode)
262 {
263 	struct vt_notifier_param param = { .vc = vc, .c = unicode };
264 	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
265 }
266 
267 static void notify_update(struct vc_data *vc)
268 {
269 	struct vt_notifier_param param = { .vc = vc };
270 	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
271 }
272 /*
273  *	Low-Level Functions
274  */
275 
276 static inline bool con_is_fg(const struct vc_data *vc)
277 {
278 	return vc->vc_num == fg_console;
279 }
280 
281 static inline bool con_should_update(const struct vc_data *vc)
282 {
283 	return con_is_visible(vc) && !console_blanked;
284 }
285 
286 static inline unsigned short *screenpos(const struct vc_data *vc, int offset,
287 		bool viewed)
288 {
289 	unsigned short *p;
290 
291 	if (!viewed)
292 		p = (unsigned short *)(vc->vc_origin + offset);
293 	else if (!vc->vc_sw->con_screen_pos)
294 		p = (unsigned short *)(vc->vc_visible_origin + offset);
295 	else
296 		p = vc->vc_sw->con_screen_pos(vc, offset);
297 	return p;
298 }
299 
300 /* Called  from the keyboard irq path.. */
301 static inline void scrolldelta(int lines)
302 {
303 	/* FIXME */
304 	/* scrolldelta needs some kind of consistency lock, but the BKL was
305 	   and still is not protecting versus the scheduled back end */
306 	scrollback_delta += lines;
307 	schedule_console_callback();
308 }
309 
310 void schedule_console_callback(void)
311 {
312 	schedule_work(&console_work);
313 }
314 
315 /*
316  * Code to manage unicode-based screen buffers
317  */
318 
319 #ifdef NO_VC_UNI_SCREEN
320 /* this disables and optimizes related code away at compile time */
321 #define get_vc_uniscr(vc) NULL
322 #else
323 #define get_vc_uniscr(vc) vc->vc_uni_screen
324 #endif
325 
326 #define VC_UNI_SCREEN_DEBUG 0
327 
328 typedef uint32_t char32_t;
329 
330 /*
331  * Our screen buffer is preceded by an array of line pointers so that
332  * scrolling only implies some pointer shuffling.
333  */
334 struct uni_screen {
335 	char32_t *lines[0];
336 };
337 
338 static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
339 {
340 	struct uni_screen *uniscr;
341 	void *p;
342 	unsigned int memsize, i;
343 
344 	/* allocate everything in one go */
345 	memsize = cols * rows * sizeof(char32_t);
346 	memsize += rows * sizeof(char32_t *);
347 	p = vmalloc(memsize);
348 	if (!p)
349 		return NULL;
350 
351 	/* initial line pointers */
352 	uniscr = p;
353 	p = uniscr->lines + rows;
354 	for (i = 0; i < rows; i++) {
355 		uniscr->lines[i] = p;
356 		p += cols * sizeof(char32_t);
357 	}
358 	return uniscr;
359 }
360 
361 static void vc_uniscr_free(struct uni_screen *uniscr)
362 {
363 	vfree(uniscr);
364 }
365 
366 static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
367 {
368 	vc_uniscr_free(vc->vc_uni_screen);
369 	vc->vc_uni_screen = new_uniscr;
370 }
371 
372 static void vc_uniscr_putc(struct vc_data *vc, char32_t uc)
373 {
374 	struct uni_screen *uniscr = get_vc_uniscr(vc);
375 
376 	if (uniscr)
377 		uniscr->lines[vc->state.y][vc->state.x] = uc;
378 }
379 
380 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
381 {
382 	struct uni_screen *uniscr = get_vc_uniscr(vc);
383 
384 	if (uniscr) {
385 		char32_t *ln = uniscr->lines[vc->state.y];
386 		unsigned int x = vc->state.x, cols = vc->vc_cols;
387 
388 		memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
389 		memset32(&ln[x], ' ', nr);
390 	}
391 }
392 
393 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
394 {
395 	struct uni_screen *uniscr = get_vc_uniscr(vc);
396 
397 	if (uniscr) {
398 		char32_t *ln = uniscr->lines[vc->state.y];
399 		unsigned int x = vc->state.x, cols = vc->vc_cols;
400 
401 		memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
402 		memset32(&ln[cols - nr], ' ', nr);
403 	}
404 }
405 
406 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
407 				 unsigned int nr)
408 {
409 	struct uni_screen *uniscr = get_vc_uniscr(vc);
410 
411 	if (uniscr) {
412 		char32_t *ln = uniscr->lines[vc->state.y];
413 
414 		memset32(&ln[x], ' ', nr);
415 	}
416 }
417 
418 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
419 				  unsigned int nr)
420 {
421 	struct uni_screen *uniscr = get_vc_uniscr(vc);
422 
423 	if (uniscr) {
424 		unsigned int cols = vc->vc_cols;
425 
426 		while (nr--)
427 			memset32(uniscr->lines[y++], ' ', cols);
428 	}
429 }
430 
431 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
432 			     enum con_scroll dir, unsigned int nr)
433 {
434 	struct uni_screen *uniscr = get_vc_uniscr(vc);
435 
436 	if (uniscr) {
437 		unsigned int i, j, k, sz, d, clear;
438 
439 		sz = b - t;
440 		clear = b - nr;
441 		d = nr;
442 		if (dir == SM_DOWN) {
443 			clear = t;
444 			d = sz - nr;
445 		}
446 		for (i = 0; i < gcd(d, sz); i++) {
447 			char32_t *tmp = uniscr->lines[t + i];
448 			j = i;
449 			while (1) {
450 				k = j + d;
451 				if (k >= sz)
452 					k -= sz;
453 				if (k == i)
454 					break;
455 				uniscr->lines[t + j] = uniscr->lines[t + k];
456 				j = k;
457 			}
458 			uniscr->lines[t + j] = tmp;
459 		}
460 		vc_uniscr_clear_lines(vc, clear, nr);
461 	}
462 }
463 
464 static void vc_uniscr_copy_area(struct uni_screen *dst,
465 				unsigned int dst_cols,
466 				unsigned int dst_rows,
467 				struct uni_screen *src,
468 				unsigned int src_cols,
469 				unsigned int src_top_row,
470 				unsigned int src_bot_row)
471 {
472 	unsigned int dst_row = 0;
473 
474 	if (!dst)
475 		return;
476 
477 	while (src_top_row < src_bot_row) {
478 		char32_t *src_line = src->lines[src_top_row];
479 		char32_t *dst_line = dst->lines[dst_row];
480 
481 		memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
482 		if (dst_cols - src_cols)
483 			memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
484 		src_top_row++;
485 		dst_row++;
486 	}
487 	while (dst_row < dst_rows) {
488 		char32_t *dst_line = dst->lines[dst_row];
489 
490 		memset32(dst_line, ' ', dst_cols);
491 		dst_row++;
492 	}
493 }
494 
495 /*
496  * Called from vcs_read() to make sure unicode screen retrieval is possible.
497  * This will initialize the unicode screen buffer if not already done.
498  * This returns 0 if OK, or a negative error code otherwise.
499  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
500  */
501 int vc_uniscr_check(struct vc_data *vc)
502 {
503 	struct uni_screen *uniscr;
504 	unsigned short *p;
505 	int x, y, mask;
506 
507 	if (__is_defined(NO_VC_UNI_SCREEN))
508 		return -EOPNOTSUPP;
509 
510 	WARN_CONSOLE_UNLOCKED();
511 
512 	if (!vc->vc_utf)
513 		return -ENODATA;
514 
515 	if (vc->vc_uni_screen)
516 		return 0;
517 
518 	uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
519 	if (!uniscr)
520 		return -ENOMEM;
521 
522 	/*
523 	 * Let's populate it initially with (imperfect) reverse translation.
524 	 * This is the next best thing we can do short of having it enabled
525 	 * from the start even when no users rely on this functionality. True
526 	 * unicode content will be available after a complete screen refresh.
527 	 */
528 	p = (unsigned short *)vc->vc_origin;
529 	mask = vc->vc_hi_font_mask | 0xff;
530 	for (y = 0; y < vc->vc_rows; y++) {
531 		char32_t *line = uniscr->lines[y];
532 		for (x = 0; x < vc->vc_cols; x++) {
533 			u16 glyph = scr_readw(p++) & mask;
534 			line[x] = inverse_translate(vc, glyph, true);
535 		}
536 	}
537 
538 	vc->vc_uni_screen = uniscr;
539 	return 0;
540 }
541 
542 /*
543  * Called from vcs_read() to get the unicode data from the screen.
544  * This must be preceded by a successful call to vc_uniscr_check() once
545  * the console lock has been taken.
546  */
547 void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed,
548 			 unsigned int row, unsigned int col, unsigned int nr)
549 {
550 	struct uni_screen *uniscr = get_vc_uniscr(vc);
551 	int offset = row * vc->vc_size_row + col * 2;
552 	unsigned long pos;
553 
554 	BUG_ON(!uniscr);
555 
556 	pos = (unsigned long)screenpos(vc, offset, viewed);
557 	if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
558 		/*
559 		 * Desired position falls in the main screen buffer.
560 		 * However the actual row/col might be different if
561 		 * scrollback is active.
562 		 */
563 		row = (pos - vc->vc_origin) / vc->vc_size_row;
564 		col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
565 		memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t));
566 	} else {
567 		/*
568 		 * Scrollback is active. For now let's simply backtranslate
569 		 * the screen glyphs until the unicode screen buffer does
570 		 * synchronize with console display drivers for a scrollback
571 		 * buffer of its own.
572 		 */
573 		u16 *p = (u16 *)pos;
574 		int mask = vc->vc_hi_font_mask | 0xff;
575 		char32_t *uni_buf = dest;
576 		while (nr--) {
577 			u16 glyph = scr_readw(p++) & mask;
578 			*uni_buf++ = inverse_translate(vc, glyph, true);
579 		}
580 	}
581 }
582 
583 /* this is for validation and debugging only */
584 static void vc_uniscr_debug_check(struct vc_data *vc)
585 {
586 	struct uni_screen *uniscr = get_vc_uniscr(vc);
587 	unsigned short *p;
588 	int x, y, mask;
589 
590 	if (!VC_UNI_SCREEN_DEBUG || !uniscr)
591 		return;
592 
593 	WARN_CONSOLE_UNLOCKED();
594 
595 	/*
596 	 * Make sure our unicode screen translates into the same glyphs
597 	 * as the actual screen. This is brutal indeed.
598 	 */
599 	p = (unsigned short *)vc->vc_origin;
600 	mask = vc->vc_hi_font_mask | 0xff;
601 	for (y = 0; y < vc->vc_rows; y++) {
602 		char32_t *line = uniscr->lines[y];
603 		for (x = 0; x < vc->vc_cols; x++) {
604 			u16 glyph = scr_readw(p++) & mask;
605 			char32_t uc = line[x];
606 			int tc = conv_uni_to_pc(vc, uc);
607 			if (tc == -4)
608 				tc = conv_uni_to_pc(vc, 0xfffd);
609 			if (tc == -4)
610 				tc = conv_uni_to_pc(vc, '?');
611 			if (tc != glyph)
612 				pr_err_ratelimited(
613 					"%s: mismatch at %d,%d: glyph=%#x tc=%#x\n",
614 					__func__, x, y, glyph, tc);
615 		}
616 	}
617 }
618 
619 
620 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
621 		enum con_scroll dir, unsigned int nr)
622 {
623 	u16 *clear, *d, *s;
624 
625 	if (t + nr >= b)
626 		nr = b - t - 1;
627 	if (b > vc->vc_rows || t >= b || nr < 1)
628 		return;
629 	vc_uniscr_scroll(vc, t, b, dir, nr);
630 	if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
631 		return;
632 
633 	s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
634 	d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
635 
636 	if (dir == SM_UP) {
637 		clear = s + (b - t - nr) * vc->vc_cols;
638 		swap(s, d);
639 	}
640 	scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
641 	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
642 }
643 
644 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
645 {
646 	unsigned int xx, yy, offset;
647 	u16 *p;
648 
649 	p = (u16 *) start;
650 	if (!vc->vc_sw->con_getxy) {
651 		offset = (start - vc->vc_origin) / 2;
652 		xx = offset % vc->vc_cols;
653 		yy = offset / vc->vc_cols;
654 	} else {
655 		int nxx, nyy;
656 		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
657 		xx = nxx; yy = nyy;
658 	}
659 	for(;;) {
660 		u16 attrib = scr_readw(p) & 0xff00;
661 		int startx = xx;
662 		u16 *q = p;
663 		while (xx < vc->vc_cols && count) {
664 			if (attrib != (scr_readw(p) & 0xff00)) {
665 				if (p > q)
666 					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
667 				startx = xx;
668 				q = p;
669 				attrib = scr_readw(p) & 0xff00;
670 			}
671 			p++;
672 			xx++;
673 			count--;
674 		}
675 		if (p > q)
676 			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
677 		if (!count)
678 			break;
679 		xx = 0;
680 		yy++;
681 		if (vc->vc_sw->con_getxy) {
682 			p = (u16 *)start;
683 			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
684 		}
685 	}
686 }
687 
688 void update_region(struct vc_data *vc, unsigned long start, int count)
689 {
690 	WARN_CONSOLE_UNLOCKED();
691 
692 	if (con_should_update(vc)) {
693 		hide_cursor(vc);
694 		do_update_region(vc, start, count);
695 		set_cursor(vc);
696 	}
697 }
698 
699 /* Structure of attributes is hardware-dependent */
700 
701 static u8 build_attr(struct vc_data *vc, u8 _color,
702 		enum vc_intensity _intensity, bool _blink, bool _underline,
703 		bool _reverse, bool _italic)
704 {
705 	if (vc->vc_sw->con_build_attr)
706 		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
707 		       _blink, _underline, _reverse, _italic);
708 
709 /*
710  * ++roman: I completely changed the attribute format for monochrome
711  * mode (!can_do_color). The formerly used MDA (monochrome display
712  * adapter) format didn't allow the combination of certain effects.
713  * Now the attribute is just a bit vector:
714  *  Bit 0..1: intensity (0..2)
715  *  Bit 2   : underline
716  *  Bit 3   : reverse
717  *  Bit 7   : blink
718  */
719 	{
720 	u8 a = _color;
721 	if (!vc->vc_can_do_color)
722 		return _intensity |
723 		       (_italic    << 1) |
724 		       (_underline << 2) |
725 		       (_reverse   << 3) |
726 		       (_blink     << 7);
727 	if (_italic)
728 		a = (a & 0xF0) | vc->vc_itcolor;
729 	else if (_underline)
730 		a = (a & 0xf0) | vc->vc_ulcolor;
731 	else if (_intensity == VCI_HALF_BRIGHT)
732 		a = (a & 0xf0) | vc->vc_halfcolor;
733 	if (_reverse)
734 		a = (a & 0x88) | (((a >> 4) | (a << 4)) & 0x77);
735 	if (_blink)
736 		a ^= 0x80;
737 	if (_intensity == VCI_BOLD)
738 		a ^= 0x08;
739 	if (vc->vc_hi_font_mask == 0x100)
740 		a <<= 1;
741 	return a;
742 	}
743 }
744 
745 static void update_attr(struct vc_data *vc)
746 {
747 	vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
748 	              vc->state.blink, vc->state.underline,
749 	              vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
750 	vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
751 				VCI_NORMAL, vc->state.blink, false,
752 				vc->vc_decscnm, false) << 8);
753 }
754 
755 /* Note: inverting the screen twice should revert to the original state */
756 void invert_screen(struct vc_data *vc, int offset, int count, bool viewed)
757 {
758 	unsigned short *p;
759 
760 	WARN_CONSOLE_UNLOCKED();
761 
762 	count /= 2;
763 	p = screenpos(vc, offset, viewed);
764 	if (vc->vc_sw->con_invert_region) {
765 		vc->vc_sw->con_invert_region(vc, p, count);
766 	} else {
767 		u16 *q = p;
768 		int cnt = count;
769 		u16 a;
770 
771 		if (!vc->vc_can_do_color) {
772 			while (cnt--) {
773 			    a = scr_readw(q);
774 			    a ^= 0x0800;
775 			    scr_writew(a, q);
776 			    q++;
777 			}
778 		} else if (vc->vc_hi_font_mask == 0x100) {
779 			while (cnt--) {
780 				a = scr_readw(q);
781 				a = (a & 0x11ff) |
782 				   ((a & 0xe000) >> 4) |
783 				   ((a & 0x0e00) << 4);
784 				scr_writew(a, q);
785 				q++;
786 			}
787 		} else {
788 			while (cnt--) {
789 				a = scr_readw(q);
790 				a = (a & 0x88ff) |
791 				   ((a & 0x7000) >> 4) |
792 				   ((a & 0x0700) << 4);
793 				scr_writew(a, q);
794 				q++;
795 			}
796 		}
797 	}
798 
799 	if (con_should_update(vc))
800 		do_update_region(vc, (unsigned long) p, count);
801 	notify_update(vc);
802 }
803 
804 /* used by selection: complement pointer position */
805 void complement_pos(struct vc_data *vc, int offset)
806 {
807 	static int old_offset = -1;
808 	static unsigned short old;
809 	static unsigned short oldx, oldy;
810 
811 	WARN_CONSOLE_UNLOCKED();
812 
813 	if (old_offset != -1 && old_offset >= 0 &&
814 	    old_offset < vc->vc_screenbuf_size) {
815 		scr_writew(old, screenpos(vc, old_offset, true));
816 		if (con_should_update(vc))
817 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
818 		notify_update(vc);
819 	}
820 
821 	old_offset = offset;
822 
823 	if (offset != -1 && offset >= 0 &&
824 	    offset < vc->vc_screenbuf_size) {
825 		unsigned short new;
826 		unsigned short *p;
827 		p = screenpos(vc, offset, true);
828 		old = scr_readw(p);
829 		new = old ^ vc->vc_complement_mask;
830 		scr_writew(new, p);
831 		if (con_should_update(vc)) {
832 			oldx = (offset >> 1) % vc->vc_cols;
833 			oldy = (offset >> 1) / vc->vc_cols;
834 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
835 		}
836 		notify_update(vc);
837 	}
838 }
839 
840 static void insert_char(struct vc_data *vc, unsigned int nr)
841 {
842 	unsigned short *p = (unsigned short *) vc->vc_pos;
843 
844 	vc_uniscr_insert(vc, nr);
845 	scr_memmovew(p + nr, p, (vc->vc_cols - vc->state.x - nr) * 2);
846 	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
847 	vc->vc_need_wrap = 0;
848 	if (con_should_update(vc))
849 		do_update_region(vc, (unsigned long) p,
850 			vc->vc_cols - vc->state.x);
851 }
852 
853 static void delete_char(struct vc_data *vc, unsigned int nr)
854 {
855 	unsigned short *p = (unsigned short *) vc->vc_pos;
856 
857 	vc_uniscr_delete(vc, nr);
858 	scr_memcpyw(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
859 	scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
860 			nr * 2);
861 	vc->vc_need_wrap = 0;
862 	if (con_should_update(vc))
863 		do_update_region(vc, (unsigned long) p,
864 			vc->vc_cols - vc->state.x);
865 }
866 
867 static int softcursor_original = -1;
868 
869 static void add_softcursor(struct vc_data *vc)
870 {
871 	int i = scr_readw((u16 *) vc->vc_pos);
872 	u32 type = vc->vc_cursor_type;
873 
874 	if (!(type & CUR_SW))
875 		return;
876 	if (softcursor_original != -1)
877 		return;
878 	softcursor_original = i;
879 	i |= CUR_SET(type);
880 	i ^= CUR_CHANGE(type);
881 	if ((type & CUR_ALWAYS_BG) &&
882 			(softcursor_original & CUR_BG) == (i & CUR_BG))
883 		i ^= CUR_BG;
884 	if ((type & CUR_INVERT_FG_BG) && (i & CUR_FG) == ((i & CUR_BG) >> 4))
885 		i ^= CUR_FG;
886 	scr_writew(i, (u16 *)vc->vc_pos);
887 	if (con_should_update(vc))
888 		vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
889 }
890 
891 static void hide_softcursor(struct vc_data *vc)
892 {
893 	if (softcursor_original != -1) {
894 		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
895 		if (con_should_update(vc))
896 			vc->vc_sw->con_putc(vc, softcursor_original,
897 					vc->state.y, vc->state.x);
898 		softcursor_original = -1;
899 	}
900 }
901 
902 static void hide_cursor(struct vc_data *vc)
903 {
904 	if (vc_is_sel(vc))
905 		clear_selection();
906 
907 	vc->vc_sw->con_cursor(vc, CM_ERASE);
908 	hide_softcursor(vc);
909 }
910 
911 static void set_cursor(struct vc_data *vc)
912 {
913 	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
914 		return;
915 	if (vc->vc_deccm) {
916 		if (vc_is_sel(vc))
917 			clear_selection();
918 		add_softcursor(vc);
919 		if (CUR_SIZE(vc->vc_cursor_type) != CUR_NONE)
920 			vc->vc_sw->con_cursor(vc, CM_DRAW);
921 	} else
922 		hide_cursor(vc);
923 }
924 
925 static void set_origin(struct vc_data *vc)
926 {
927 	WARN_CONSOLE_UNLOCKED();
928 
929 	if (!con_is_visible(vc) ||
930 	    !vc->vc_sw->con_set_origin ||
931 	    !vc->vc_sw->con_set_origin(vc))
932 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
933 	vc->vc_visible_origin = vc->vc_origin;
934 	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
935 	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->state.y +
936 		2 * vc->state.x;
937 }
938 
939 static void save_screen(struct vc_data *vc)
940 {
941 	WARN_CONSOLE_UNLOCKED();
942 
943 	if (vc->vc_sw->con_save_screen)
944 		vc->vc_sw->con_save_screen(vc);
945 }
946 
947 static void flush_scrollback(struct vc_data *vc)
948 {
949 	WARN_CONSOLE_UNLOCKED();
950 
951 	set_origin(vc);
952 	if (vc->vc_sw->con_flush_scrollback) {
953 		vc->vc_sw->con_flush_scrollback(vc);
954 	} else if (con_is_visible(vc)) {
955 		/*
956 		 * When no con_flush_scrollback method is provided then the
957 		 * legacy way for flushing the scrollback buffer is to use
958 		 * a side effect of the con_switch method. We do it only on
959 		 * the foreground console as background consoles have no
960 		 * scrollback buffers in that case and we obviously don't
961 		 * want to switch to them.
962 		 */
963 		hide_cursor(vc);
964 		vc->vc_sw->con_switch(vc);
965 		set_cursor(vc);
966 	}
967 }
968 
969 /*
970  *	Redrawing of screen
971  */
972 
973 void clear_buffer_attributes(struct vc_data *vc)
974 {
975 	unsigned short *p = (unsigned short *)vc->vc_origin;
976 	int count = vc->vc_screenbuf_size / 2;
977 	int mask = vc->vc_hi_font_mask | 0xff;
978 
979 	for (; count > 0; count--, p++) {
980 		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
981 	}
982 }
983 
984 void redraw_screen(struct vc_data *vc, int is_switch)
985 {
986 	int redraw = 0;
987 
988 	WARN_CONSOLE_UNLOCKED();
989 
990 	if (!vc) {
991 		/* strange ... */
992 		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
993 		return;
994 	}
995 
996 	if (is_switch) {
997 		struct vc_data *old_vc = vc_cons[fg_console].d;
998 		if (old_vc == vc)
999 			return;
1000 		if (!con_is_visible(vc))
1001 			redraw = 1;
1002 		*vc->vc_display_fg = vc;
1003 		fg_console = vc->vc_num;
1004 		hide_cursor(old_vc);
1005 		if (!con_is_visible(old_vc)) {
1006 			save_screen(old_vc);
1007 			set_origin(old_vc);
1008 		}
1009 		if (tty0dev)
1010 			sysfs_notify(&tty0dev->kobj, NULL, "active");
1011 	} else {
1012 		hide_cursor(vc);
1013 		redraw = 1;
1014 	}
1015 
1016 	if (redraw) {
1017 		int update;
1018 		int old_was_color = vc->vc_can_do_color;
1019 
1020 		set_origin(vc);
1021 		update = vc->vc_sw->con_switch(vc);
1022 		set_palette(vc);
1023 		/*
1024 		 * If console changed from mono<->color, the best we can do
1025 		 * is to clear the buffer attributes. As it currently stands,
1026 		 * rebuilding new attributes from the old buffer is not doable
1027 		 * without overly complex code.
1028 		 */
1029 		if (old_was_color != vc->vc_can_do_color) {
1030 			update_attr(vc);
1031 			clear_buffer_attributes(vc);
1032 		}
1033 
1034 		if (update && vc->vc_mode != KD_GRAPHICS)
1035 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1036 	}
1037 	set_cursor(vc);
1038 	if (is_switch) {
1039 		vt_set_leds_compute_shiftstate();
1040 		notify_update(vc);
1041 	}
1042 }
1043 
1044 /*
1045  *	Allocation, freeing and resizing of VTs.
1046  */
1047 
1048 int vc_cons_allocated(unsigned int i)
1049 {
1050 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1051 }
1052 
1053 static void visual_init(struct vc_data *vc, int num, int init)
1054 {
1055 	/* ++Geert: vc->vc_sw->con_init determines console size */
1056 	if (vc->vc_sw)
1057 		module_put(vc->vc_sw->owner);
1058 	vc->vc_sw = conswitchp;
1059 #ifndef VT_SINGLE_DRIVER
1060 	if (con_driver_map[num])
1061 		vc->vc_sw = con_driver_map[num];
1062 #endif
1063 	__module_get(vc->vc_sw->owner);
1064 	vc->vc_num = num;
1065 	vc->vc_display_fg = &master_display_fg;
1066 	if (vc->vc_uni_pagedir_loc)
1067 		con_free_unimap(vc);
1068 	vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
1069 	vc->vc_uni_pagedir = NULL;
1070 	vc->vc_hi_font_mask = 0;
1071 	vc->vc_complement_mask = 0;
1072 	vc->vc_can_do_color = 0;
1073 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1074 	vc->vc_sw->con_init(vc, init);
1075 	if (!vc->vc_complement_mask)
1076 		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1077 	vc->vc_s_complement_mask = vc->vc_complement_mask;
1078 	vc->vc_size_row = vc->vc_cols << 1;
1079 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1080 }
1081 
1082 
1083 static void visual_deinit(struct vc_data *vc)
1084 {
1085 	vc->vc_sw->con_deinit(vc);
1086 	module_put(vc->vc_sw->owner);
1087 }
1088 
1089 static void vc_port_destruct(struct tty_port *port)
1090 {
1091 	struct vc_data *vc = container_of(port, struct vc_data, port);
1092 
1093 	kfree(vc);
1094 }
1095 
1096 static const struct tty_port_operations vc_port_ops = {
1097 	.destruct = vc_port_destruct,
1098 };
1099 
1100 /*
1101  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1102  * [this is to be used together with some user program
1103  * like resize that changes the hardware videomode]
1104  */
1105 #define VC_MAXCOL (32767)
1106 #define VC_MAXROW (32767)
1107 
1108 int vc_allocate(unsigned int currcons)	/* return 0 on success */
1109 {
1110 	struct vt_notifier_param param;
1111 	struct vc_data *vc;
1112 	int err;
1113 
1114 	WARN_CONSOLE_UNLOCKED();
1115 
1116 	if (currcons >= MAX_NR_CONSOLES)
1117 		return -ENXIO;
1118 
1119 	if (vc_cons[currcons].d)
1120 		return 0;
1121 
1122 	/* due to the granularity of kmalloc, we waste some memory here */
1123 	/* the alloc is done in two steps, to optimize the common situation
1124 	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
1125 	/* although the numbers above are not valid since long ago, the
1126 	   point is still up-to-date and the comment still has its value
1127 	   even if only as a historical artifact.  --mj, July 1998 */
1128 	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1129 	if (!vc)
1130 		return -ENOMEM;
1131 
1132 	vc_cons[currcons].d = vc;
1133 	tty_port_init(&vc->port);
1134 	vc->port.ops = &vc_port_ops;
1135 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1136 
1137 	visual_init(vc, currcons, 1);
1138 
1139 	if (!*vc->vc_uni_pagedir_loc)
1140 		con_set_default_unimap(vc);
1141 
1142 	err = -EINVAL;
1143 	if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
1144 	    vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
1145 		goto err_free;
1146 	err = -ENOMEM;
1147 	vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1148 	if (!vc->vc_screenbuf)
1149 		goto err_free;
1150 
1151 	/* If no drivers have overridden us and the user didn't pass a
1152 	   boot option, default to displaying the cursor */
1153 	if (global_cursor_default == -1)
1154 		global_cursor_default = 1;
1155 
1156 	vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
1157 	vcs_make_sysfs(currcons);
1158 	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1159 
1160 	return 0;
1161 err_free:
1162 	visual_deinit(vc);
1163 	kfree(vc);
1164 	vc_cons[currcons].d = NULL;
1165 	return err;
1166 }
1167 
1168 static inline int resize_screen(struct vc_data *vc, int width, int height,
1169 				int user)
1170 {
1171 	/* Resizes the resolution of the display adapater */
1172 	int err = 0;
1173 
1174 	if (vc->vc_sw->con_resize)
1175 		err = vc->vc_sw->con_resize(vc, width, height, user);
1176 
1177 	return err;
1178 }
1179 
1180 /**
1181  *	vc_do_resize	-	resizing method for the tty
1182  *	@tty: tty being resized
1183  *	@vc: virtual console private data
1184  *	@cols: columns
1185  *	@lines: lines
1186  *
1187  *	Resize a virtual console, clipping according to the actual constraints.
1188  *	If the caller passes a tty structure then update the termios winsize
1189  *	information and perform any necessary signal handling.
1190  *
1191  *	Caller must hold the console semaphore. Takes the termios rwsem and
1192  *	ctrl.lock of the tty IFF a tty is passed.
1193  */
1194 
1195 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1196 				unsigned int cols, unsigned int lines)
1197 {
1198 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1199 	unsigned long end;
1200 	unsigned int old_rows, old_row_size, first_copied_row;
1201 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1202 	unsigned int user;
1203 	unsigned short *oldscreen, *newscreen;
1204 	struct uni_screen *new_uniscr = NULL;
1205 
1206 	WARN_CONSOLE_UNLOCKED();
1207 
1208 	if (!vc)
1209 		return -ENXIO;
1210 
1211 	user = vc->vc_resize_user;
1212 	vc->vc_resize_user = 0;
1213 
1214 	if (cols > VC_MAXCOL || lines > VC_MAXROW)
1215 		return -EINVAL;
1216 
1217 	new_cols = (cols ? cols : vc->vc_cols);
1218 	new_rows = (lines ? lines : vc->vc_rows);
1219 	new_row_size = new_cols << 1;
1220 	new_screen_size = new_row_size * new_rows;
1221 
1222 	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
1223 		return 0;
1224 
1225 	if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
1226 		return -EINVAL;
1227 	newscreen = kzalloc(new_screen_size, GFP_USER);
1228 	if (!newscreen)
1229 		return -ENOMEM;
1230 
1231 	if (get_vc_uniscr(vc)) {
1232 		new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1233 		if (!new_uniscr) {
1234 			kfree(newscreen);
1235 			return -ENOMEM;
1236 		}
1237 	}
1238 
1239 	if (vc_is_sel(vc))
1240 		clear_selection();
1241 
1242 	old_rows = vc->vc_rows;
1243 	old_row_size = vc->vc_size_row;
1244 
1245 	err = resize_screen(vc, new_cols, new_rows, user);
1246 	if (err) {
1247 		kfree(newscreen);
1248 		vc_uniscr_free(new_uniscr);
1249 		return err;
1250 	}
1251 
1252 	vc->vc_rows = new_rows;
1253 	vc->vc_cols = new_cols;
1254 	vc->vc_size_row = new_row_size;
1255 	vc->vc_screenbuf_size = new_screen_size;
1256 
1257 	rlth = min(old_row_size, new_row_size);
1258 	rrem = new_row_size - rlth;
1259 	old_origin = vc->vc_origin;
1260 	new_origin = (long) newscreen;
1261 	new_scr_end = new_origin + new_screen_size;
1262 
1263 	if (vc->state.y > new_rows) {
1264 		if (old_rows - vc->state.y < new_rows) {
1265 			/*
1266 			 * Cursor near the bottom, copy contents from the
1267 			 * bottom of buffer
1268 			 */
1269 			first_copied_row = (old_rows - new_rows);
1270 		} else {
1271 			/*
1272 			 * Cursor is in no man's land, copy 1/2 screenful
1273 			 * from the top and bottom of cursor position
1274 			 */
1275 			first_copied_row = (vc->state.y - new_rows/2);
1276 		}
1277 		old_origin += first_copied_row * old_row_size;
1278 	} else
1279 		first_copied_row = 0;
1280 	end = old_origin + old_row_size * min(old_rows, new_rows);
1281 
1282 	vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1283 			    get_vc_uniscr(vc), rlth/2, first_copied_row,
1284 			    min(old_rows, new_rows));
1285 	vc_uniscr_set(vc, new_uniscr);
1286 
1287 	update_attr(vc);
1288 
1289 	while (old_origin < end) {
1290 		scr_memcpyw((unsigned short *) new_origin,
1291 			    (unsigned short *) old_origin, rlth);
1292 		if (rrem)
1293 			scr_memsetw((void *)(new_origin + rlth),
1294 				    vc->vc_video_erase_char, rrem);
1295 		old_origin += old_row_size;
1296 		new_origin += new_row_size;
1297 	}
1298 	if (new_scr_end > new_origin)
1299 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1300 			    new_scr_end - new_origin);
1301 	oldscreen = vc->vc_screenbuf;
1302 	vc->vc_screenbuf = newscreen;
1303 	vc->vc_screenbuf_size = new_screen_size;
1304 	set_origin(vc);
1305 	kfree(oldscreen);
1306 
1307 	/* do part of a reset_terminal() */
1308 	vc->vc_top = 0;
1309 	vc->vc_bottom = vc->vc_rows;
1310 	gotoxy(vc, vc->state.x, vc->state.y);
1311 	save_cur(vc);
1312 
1313 	if (tty) {
1314 		/* Rewrite the requested winsize data with the actual
1315 		   resulting sizes */
1316 		struct winsize ws;
1317 		memset(&ws, 0, sizeof(ws));
1318 		ws.ws_row = vc->vc_rows;
1319 		ws.ws_col = vc->vc_cols;
1320 		ws.ws_ypixel = vc->vc_scan_lines;
1321 		tty_do_resize(tty, &ws);
1322 	}
1323 
1324 	if (con_is_visible(vc))
1325 		update_screen(vc);
1326 	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1327 	notify_update(vc);
1328 	return err;
1329 }
1330 
1331 /**
1332  *	vc_resize		-	resize a VT
1333  *	@vc: virtual console
1334  *	@cols: columns
1335  *	@rows: rows
1336  *
1337  *	Resize a virtual console as seen from the console end of things. We
1338  *	use the common vc_do_resize methods to update the structures. The
1339  *	caller must hold the console sem to protect console internals and
1340  *	vc->port.tty
1341  */
1342 
1343 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1344 {
1345 	return vc_do_resize(vc->port.tty, vc, cols, rows);
1346 }
1347 
1348 /**
1349  *	vt_resize		-	resize a VT
1350  *	@tty: tty to resize
1351  *	@ws: winsize attributes
1352  *
1353  *	Resize a virtual terminal. This is called by the tty layer as we
1354  *	register our own handler for resizing. The mutual helper does all
1355  *	the actual work.
1356  *
1357  *	Takes the console sem and the called methods then take the tty
1358  *	termios_rwsem and the tty ctrl.lock in that order.
1359  */
1360 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1361 {
1362 	struct vc_data *vc = tty->driver_data;
1363 	int ret;
1364 
1365 	console_lock();
1366 	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1367 	console_unlock();
1368 	return ret;
1369 }
1370 
1371 struct vc_data *vc_deallocate(unsigned int currcons)
1372 {
1373 	struct vc_data *vc = NULL;
1374 
1375 	WARN_CONSOLE_UNLOCKED();
1376 
1377 	if (vc_cons_allocated(currcons)) {
1378 		struct vt_notifier_param param;
1379 
1380 		param.vc = vc = vc_cons[currcons].d;
1381 		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1382 		vcs_remove_sysfs(currcons);
1383 		visual_deinit(vc);
1384 		con_free_unimap(vc);
1385 		put_pid(vc->vt_pid);
1386 		vc_uniscr_set(vc, NULL);
1387 		kfree(vc->vc_screenbuf);
1388 		vc_cons[currcons].d = NULL;
1389 	}
1390 	return vc;
1391 }
1392 
1393 /*
1394  *	VT102 emulator
1395  */
1396 
1397 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1398 
1399 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1400 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1401 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1402 
1403 #define decarm		VC_REPEAT
1404 #define decckm		VC_CKMODE
1405 #define kbdapplic	VC_APPLIC
1406 #define lnm		VC_CRLF
1407 
1408 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1409 				       8,12,10,14, 9,13,11,15 };
1410 
1411 /* the default colour table, for VGA+ colour systems */
1412 unsigned char default_red[] = {
1413 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1414 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1415 };
1416 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1417 
1418 unsigned char default_grn[] = {
1419 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1420 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1421 };
1422 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1423 
1424 unsigned char default_blu[] = {
1425 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1426 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1427 };
1428 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1429 
1430 /*
1431  * gotoxy() must verify all boundaries, because the arguments
1432  * might also be negative. If the given position is out of
1433  * bounds, the cursor is placed at the nearest margin.
1434  */
1435 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1436 {
1437 	int min_y, max_y;
1438 
1439 	if (new_x < 0)
1440 		vc->state.x = 0;
1441 	else {
1442 		if (new_x >= vc->vc_cols)
1443 			vc->state.x = vc->vc_cols - 1;
1444 		else
1445 			vc->state.x = new_x;
1446 	}
1447 
1448  	if (vc->vc_decom) {
1449 		min_y = vc->vc_top;
1450 		max_y = vc->vc_bottom;
1451 	} else {
1452 		min_y = 0;
1453 		max_y = vc->vc_rows;
1454 	}
1455 	if (new_y < min_y)
1456 		vc->state.y = min_y;
1457 	else if (new_y >= max_y)
1458 		vc->state.y = max_y - 1;
1459 	else
1460 		vc->state.y = new_y;
1461 	vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
1462 		(vc->state.x << 1);
1463 	vc->vc_need_wrap = 0;
1464 }
1465 
1466 /* for absolute user moves, when decom is set */
1467 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1468 {
1469 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1470 }
1471 
1472 void scrollback(struct vc_data *vc)
1473 {
1474 	scrolldelta(-(vc->vc_rows / 2));
1475 }
1476 
1477 void scrollfront(struct vc_data *vc, int lines)
1478 {
1479 	if (!lines)
1480 		lines = vc->vc_rows / 2;
1481 	scrolldelta(lines);
1482 }
1483 
1484 static void lf(struct vc_data *vc)
1485 {
1486     	/* don't scroll if above bottom of scrolling region, or
1487 	 * if below scrolling region
1488 	 */
1489 	if (vc->state.y + 1 == vc->vc_bottom)
1490 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1491 	else if (vc->state.y < vc->vc_rows - 1) {
1492 		vc->state.y++;
1493 		vc->vc_pos += vc->vc_size_row;
1494 	}
1495 	vc->vc_need_wrap = 0;
1496 	notify_write(vc, '\n');
1497 }
1498 
1499 static void ri(struct vc_data *vc)
1500 {
1501     	/* don't scroll if below top of scrolling region, or
1502 	 * if above scrolling region
1503 	 */
1504 	if (vc->state.y == vc->vc_top)
1505 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1506 	else if (vc->state.y > 0) {
1507 		vc->state.y--;
1508 		vc->vc_pos -= vc->vc_size_row;
1509 	}
1510 	vc->vc_need_wrap = 0;
1511 }
1512 
1513 static inline void cr(struct vc_data *vc)
1514 {
1515 	vc->vc_pos -= vc->state.x << 1;
1516 	vc->vc_need_wrap = vc->state.x = 0;
1517 	notify_write(vc, '\r');
1518 }
1519 
1520 static inline void bs(struct vc_data *vc)
1521 {
1522 	if (vc->state.x) {
1523 		vc->vc_pos -= 2;
1524 		vc->state.x--;
1525 		vc->vc_need_wrap = 0;
1526 		notify_write(vc, '\b');
1527 	}
1528 }
1529 
1530 static inline void del(struct vc_data *vc)
1531 {
1532 	/* ignored */
1533 }
1534 
1535 static void csi_J(struct vc_data *vc, int vpar)
1536 {
1537 	unsigned int count;
1538 	unsigned short * start;
1539 
1540 	switch (vpar) {
1541 		case 0:	/* erase from cursor to end of display */
1542 			vc_uniscr_clear_line(vc, vc->state.x,
1543 					     vc->vc_cols - vc->state.x);
1544 			vc_uniscr_clear_lines(vc, vc->state.y + 1,
1545 					      vc->vc_rows - vc->state.y - 1);
1546 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1547 			start = (unsigned short *)vc->vc_pos;
1548 			break;
1549 		case 1:	/* erase from start to cursor */
1550 			vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
1551 			vc_uniscr_clear_lines(vc, 0, vc->state.y);
1552 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1553 			start = (unsigned short *)vc->vc_origin;
1554 			break;
1555 		case 3: /* include scrollback */
1556 			flush_scrollback(vc);
1557 			fallthrough;
1558 		case 2: /* erase whole display */
1559 			vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1560 			count = vc->vc_cols * vc->vc_rows;
1561 			start = (unsigned short *)vc->vc_origin;
1562 			break;
1563 		default:
1564 			return;
1565 	}
1566 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1567 	if (con_should_update(vc))
1568 		do_update_region(vc, (unsigned long) start, count);
1569 	vc->vc_need_wrap = 0;
1570 }
1571 
1572 static void csi_K(struct vc_data *vc, int vpar)
1573 {
1574 	unsigned int count;
1575 	unsigned short *start = (unsigned short *)vc->vc_pos;
1576 	int offset;
1577 
1578 	switch (vpar) {
1579 		case 0:	/* erase from cursor to end of line */
1580 			offset = 0;
1581 			count = vc->vc_cols - vc->state.x;
1582 			break;
1583 		case 1:	/* erase from start of line to cursor */
1584 			offset = -vc->state.x;
1585 			count = vc->state.x + 1;
1586 			break;
1587 		case 2: /* erase whole line */
1588 			offset = -vc->state.x;
1589 			count = vc->vc_cols;
1590 			break;
1591 		default:
1592 			return;
1593 	}
1594 	vc_uniscr_clear_line(vc, vc->state.x + offset, count);
1595 	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1596 	vc->vc_need_wrap = 0;
1597 	if (con_should_update(vc))
1598 		do_update_region(vc, (unsigned long)(start + offset), count);
1599 }
1600 
1601 /* erase the following vpar positions */
1602 static void csi_X(struct vc_data *vc, unsigned int vpar)
1603 {					  /* not vt100? */
1604 	unsigned int count;
1605 
1606 	if (!vpar)
1607 		vpar++;
1608 
1609 	count = min(vpar, vc->vc_cols - vc->state.x);
1610 
1611 	vc_uniscr_clear_line(vc, vc->state.x, count);
1612 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1613 	if (con_should_update(vc))
1614 		vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
1615 	vc->vc_need_wrap = 0;
1616 }
1617 
1618 static void default_attr(struct vc_data *vc)
1619 {
1620 	vc->state.intensity = VCI_NORMAL;
1621 	vc->state.italic = false;
1622 	vc->state.underline = false;
1623 	vc->state.reverse = false;
1624 	vc->state.blink = false;
1625 	vc->state.color = vc->vc_def_color;
1626 }
1627 
1628 struct rgb { u8 r; u8 g; u8 b; };
1629 
1630 static void rgb_from_256(int i, struct rgb *c)
1631 {
1632 	if (i < 8) {            /* Standard colours. */
1633 		c->r = i&1 ? 0xaa : 0x00;
1634 		c->g = i&2 ? 0xaa : 0x00;
1635 		c->b = i&4 ? 0xaa : 0x00;
1636 	} else if (i < 16) {
1637 		c->r = i&1 ? 0xff : 0x55;
1638 		c->g = i&2 ? 0xff : 0x55;
1639 		c->b = i&4 ? 0xff : 0x55;
1640 	} else if (i < 232) {   /* 6x6x6 colour cube. */
1641 		c->r = (i - 16) / 36 * 85 / 2;
1642 		c->g = (i - 16) / 6 % 6 * 85 / 2;
1643 		c->b = (i - 16) % 6 * 85 / 2;
1644 	} else                  /* Grayscale ramp. */
1645 		c->r = c->g = c->b = i * 10 - 2312;
1646 }
1647 
1648 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1649 {
1650 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1651 
1652 	if (c->r > max / 2)
1653 		hue |= 4;
1654 	if (c->g > max / 2)
1655 		hue |= 2;
1656 	if (c->b > max / 2)
1657 		hue |= 1;
1658 
1659 	if (hue == 7 && max <= 0x55) {
1660 		hue = 0;
1661 		vc->state.intensity = VCI_BOLD;
1662 	} else if (max > 0xaa)
1663 		vc->state.intensity = VCI_BOLD;
1664 	else
1665 		vc->state.intensity = VCI_NORMAL;
1666 
1667 	vc->state.color = (vc->state.color & 0xf0) | hue;
1668 }
1669 
1670 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1671 {
1672 	/* For backgrounds, err on the dark side. */
1673 	vc->state.color = (vc->state.color & 0x0f)
1674 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1675 }
1676 
1677 /*
1678  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1679  * and thus need to be detected and ignored by hand. That standard also
1680  * wants : rather than ; as separators but sequences containing : are currently
1681  * completely ignored by the parser.
1682  *
1683  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1684  * supporting them.
1685  */
1686 static int vc_t416_color(struct vc_data *vc, int i,
1687 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1688 {
1689 	struct rgb c;
1690 
1691 	i++;
1692 	if (i > vc->vc_npar)
1693 		return i;
1694 
1695 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1696 		/* 256 colours */
1697 		i++;
1698 		rgb_from_256(vc->vc_par[i], &c);
1699 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1700 		/* 24 bit */
1701 		c.r = vc->vc_par[i + 1];
1702 		c.g = vc->vc_par[i + 2];
1703 		c.b = vc->vc_par[i + 3];
1704 		i += 3;
1705 	} else
1706 		return i;
1707 
1708 	set_color(vc, &c);
1709 
1710 	return i;
1711 }
1712 
1713 /* console_lock is held */
1714 static void csi_m(struct vc_data *vc)
1715 {
1716 	int i;
1717 
1718 	for (i = 0; i <= vc->vc_npar; i++)
1719 		switch (vc->vc_par[i]) {
1720 		case 0:	/* all attributes off */
1721 			default_attr(vc);
1722 			break;
1723 		case 1:
1724 			vc->state.intensity = VCI_BOLD;
1725 			break;
1726 		case 2:
1727 			vc->state.intensity = VCI_HALF_BRIGHT;
1728 			break;
1729 		case 3:
1730 			vc->state.italic = true;
1731 			break;
1732 		case 21:
1733 			/*
1734 			 * No console drivers support double underline, so
1735 			 * convert it to a single underline.
1736 			 */
1737 		case 4:
1738 			vc->state.underline = true;
1739 			break;
1740 		case 5:
1741 			vc->state.blink = true;
1742 			break;
1743 		case 7:
1744 			vc->state.reverse = true;
1745 			break;
1746 		case 10: /* ANSI X3.64-1979 (SCO-ish?)
1747 			  * Select primary font, don't display control chars if
1748 			  * defined, don't set bit 8 on output.
1749 			  */
1750 			vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset], vc);
1751 			vc->vc_disp_ctrl = 0;
1752 			vc->vc_toggle_meta = 0;
1753 			break;
1754 		case 11: /* ANSI X3.64-1979 (SCO-ish?)
1755 			  * Select first alternate font, lets chars < 32 be
1756 			  * displayed as ROM chars.
1757 			  */
1758 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1759 			vc->vc_disp_ctrl = 1;
1760 			vc->vc_toggle_meta = 0;
1761 			break;
1762 		case 12: /* ANSI X3.64-1979 (SCO-ish?)
1763 			  * Select second alternate font, toggle high bit
1764 			  * before displaying as ROM char.
1765 			  */
1766 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1767 			vc->vc_disp_ctrl = 1;
1768 			vc->vc_toggle_meta = 1;
1769 			break;
1770 		case 22:
1771 			vc->state.intensity = VCI_NORMAL;
1772 			break;
1773 		case 23:
1774 			vc->state.italic = false;
1775 			break;
1776 		case 24:
1777 			vc->state.underline = false;
1778 			break;
1779 		case 25:
1780 			vc->state.blink = false;
1781 			break;
1782 		case 27:
1783 			vc->state.reverse = false;
1784 			break;
1785 		case 38:
1786 			i = vc_t416_color(vc, i, rgb_foreground);
1787 			break;
1788 		case 48:
1789 			i = vc_t416_color(vc, i, rgb_background);
1790 			break;
1791 		case 39:
1792 			vc->state.color = (vc->vc_def_color & 0x0f) |
1793 				(vc->state.color & 0xf0);
1794 			break;
1795 		case 49:
1796 			vc->state.color = (vc->vc_def_color & 0xf0) |
1797 				(vc->state.color & 0x0f);
1798 			break;
1799 		default:
1800 			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1801 				if (vc->vc_par[i] < 100)
1802 					vc->state.intensity = VCI_BOLD;
1803 				vc->vc_par[i] -= 60;
1804 			}
1805 			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1806 				vc->state.color = color_table[vc->vc_par[i] - 30]
1807 					| (vc->state.color & 0xf0);
1808 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1809 				vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
1810 					| (vc->state.color & 0x0f);
1811 			break;
1812 		}
1813 	update_attr(vc);
1814 }
1815 
1816 static void respond_string(const char *p, size_t len, struct tty_port *port)
1817 {
1818 	tty_insert_flip_string(port, p, len);
1819 	tty_schedule_flip(port);
1820 }
1821 
1822 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1823 {
1824 	char buf[40];
1825 	int len;
1826 
1827 	len = sprintf(buf, "\033[%d;%dR", vc->state.y +
1828 			(vc->vc_decom ? vc->vc_top + 1 : 1),
1829 			vc->state.x + 1);
1830 	respond_string(buf, len, tty->port);
1831 }
1832 
1833 static inline void status_report(struct tty_struct *tty)
1834 {
1835 	static const char teminal_ok[] = "\033[0n";
1836 
1837 	respond_string(teminal_ok, strlen(teminal_ok), tty->port);
1838 }
1839 
1840 static inline void respond_ID(struct tty_struct *tty)
1841 {
1842 	/* terminal answer to an ESC-Z or csi0c query. */
1843 	static const char vt102_id[] = "\033[?6c";
1844 
1845 	respond_string(vt102_id, strlen(vt102_id), tty->port);
1846 }
1847 
1848 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1849 {
1850 	char buf[8];
1851 	int len;
1852 
1853 	len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
1854 			(char)('!' + mrx), (char)('!' + mry));
1855 	respond_string(buf, len, tty->port);
1856 }
1857 
1858 /* invoked via ioctl(TIOCLINUX) and through set_selection_user */
1859 int mouse_reporting(void)
1860 {
1861 	return vc_cons[fg_console].d->vc_report_mouse;
1862 }
1863 
1864 /* console_lock is held */
1865 static void set_mode(struct vc_data *vc, int on_off)
1866 {
1867 	int i;
1868 
1869 	for (i = 0; i <= vc->vc_npar; i++)
1870 		if (vc->vc_priv == EPdec) {
1871 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1872 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1873 				if (on_off)
1874 					set_kbd(vc, decckm);
1875 				else
1876 					clr_kbd(vc, decckm);
1877 				break;
1878 			case 3:	/* 80/132 mode switch unimplemented */
1879 #if 0
1880 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1881 				/* this alone does not suffice; some user mode
1882 				   utility has to change the hardware regs */
1883 #endif
1884 				break;
1885 			case 5:			/* Inverted screen on/off */
1886 				if (vc->vc_decscnm != on_off) {
1887 					vc->vc_decscnm = on_off;
1888 					invert_screen(vc, 0,
1889 							vc->vc_screenbuf_size,
1890 							false);
1891 					update_attr(vc);
1892 				}
1893 				break;
1894 			case 6:			/* Origin relative/absolute */
1895 				vc->vc_decom = on_off;
1896 				gotoxay(vc, 0, 0);
1897 				break;
1898 			case 7:			/* Autowrap on/off */
1899 				vc->vc_decawm = on_off;
1900 				break;
1901 			case 8:			/* Autorepeat on/off */
1902 				if (on_off)
1903 					set_kbd(vc, decarm);
1904 				else
1905 					clr_kbd(vc, decarm);
1906 				break;
1907 			case 9:
1908 				vc->vc_report_mouse = on_off ? 1 : 0;
1909 				break;
1910 			case 25:		/* Cursor on/off */
1911 				vc->vc_deccm = on_off;
1912 				break;
1913 			case 1000:
1914 				vc->vc_report_mouse = on_off ? 2 : 0;
1915 				break;
1916 			}
1917 		} else {
1918 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1919 			case 3:			/* Monitor (display ctrls) */
1920 				vc->vc_disp_ctrl = on_off;
1921 				break;
1922 			case 4:			/* Insert Mode on/off */
1923 				vc->vc_decim = on_off;
1924 				break;
1925 			case 20:		/* Lf, Enter == CrLf/Lf */
1926 				if (on_off)
1927 					set_kbd(vc, lnm);
1928 				else
1929 					clr_kbd(vc, lnm);
1930 				break;
1931 			}
1932 		}
1933 }
1934 
1935 /* console_lock is held */
1936 static void setterm_command(struct vc_data *vc)
1937 {
1938 	switch (vc->vc_par[0]) {
1939 	case 1:	/* set color for underline mode */
1940 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1941 			vc->vc_ulcolor = color_table[vc->vc_par[1]];
1942 			if (vc->state.underline)
1943 				update_attr(vc);
1944 		}
1945 		break;
1946 	case 2:	/* set color for half intensity mode */
1947 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1948 			vc->vc_halfcolor = color_table[vc->vc_par[1]];
1949 			if (vc->state.intensity == VCI_HALF_BRIGHT)
1950 				update_attr(vc);
1951 		}
1952 		break;
1953 	case 8:	/* store colors as defaults */
1954 		vc->vc_def_color = vc->vc_attr;
1955 		if (vc->vc_hi_font_mask == 0x100)
1956 			vc->vc_def_color >>= 1;
1957 		default_attr(vc);
1958 		update_attr(vc);
1959 		break;
1960 	case 9:	/* set blanking interval */
1961 		blankinterval = min(vc->vc_par[1], 60U) * 60;
1962 		poke_blanked_console();
1963 		break;
1964 	case 10: /* set bell frequency in Hz */
1965 		if (vc->vc_npar >= 1)
1966 			vc->vc_bell_pitch = vc->vc_par[1];
1967 		else
1968 			vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1969 		break;
1970 	case 11: /* set bell duration in msec */
1971 		if (vc->vc_npar >= 1)
1972 			vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1973 				msecs_to_jiffies(vc->vc_par[1]) : 0;
1974 		else
1975 			vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1976 		break;
1977 	case 12: /* bring specified console to the front */
1978 		if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1979 			set_console(vc->vc_par[1] - 1);
1980 		break;
1981 	case 13: /* unblank the screen */
1982 		poke_blanked_console();
1983 		break;
1984 	case 14: /* set vesa powerdown interval */
1985 		vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
1986 		break;
1987 	case 15: /* activate the previous console */
1988 		set_console(last_console);
1989 		break;
1990 	case 16: /* set cursor blink duration in msec */
1991 		if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1992 				vc->vc_par[1] <= USHRT_MAX)
1993 			vc->vc_cur_blink_ms = vc->vc_par[1];
1994 		else
1995 			vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1996 		break;
1997 	}
1998 }
1999 
2000 /* console_lock is held */
2001 static void csi_at(struct vc_data *vc, unsigned int nr)
2002 {
2003 	if (nr > vc->vc_cols - vc->state.x)
2004 		nr = vc->vc_cols - vc->state.x;
2005 	else if (!nr)
2006 		nr = 1;
2007 	insert_char(vc, nr);
2008 }
2009 
2010 /* console_lock is held */
2011 static void csi_L(struct vc_data *vc, unsigned int nr)
2012 {
2013 	if (nr > vc->vc_rows - vc->state.y)
2014 		nr = vc->vc_rows - vc->state.y;
2015 	else if (!nr)
2016 		nr = 1;
2017 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
2018 	vc->vc_need_wrap = 0;
2019 }
2020 
2021 /* console_lock is held */
2022 static void csi_P(struct vc_data *vc, unsigned int nr)
2023 {
2024 	if (nr > vc->vc_cols - vc->state.x)
2025 		nr = vc->vc_cols - vc->state.x;
2026 	else if (!nr)
2027 		nr = 1;
2028 	delete_char(vc, nr);
2029 }
2030 
2031 /* console_lock is held */
2032 static void csi_M(struct vc_data *vc, unsigned int nr)
2033 {
2034 	if (nr > vc->vc_rows - vc->state.y)
2035 		nr = vc->vc_rows - vc->state.y;
2036 	else if (!nr)
2037 		nr=1;
2038 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
2039 	vc->vc_need_wrap = 0;
2040 }
2041 
2042 /* console_lock is held (except via vc_init->reset_terminal */
2043 static void save_cur(struct vc_data *vc)
2044 {
2045 	memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
2046 }
2047 
2048 /* console_lock is held */
2049 static void restore_cur(struct vc_data *vc)
2050 {
2051 	memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
2052 
2053 	gotoxy(vc, vc->state.x, vc->state.y);
2054 	vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
2055 			vc);
2056 	update_attr(vc);
2057 	vc->vc_need_wrap = 0;
2058 }
2059 
2060 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2061 	EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2062 	ESpalette, ESosc, ESapc, ESpm, ESdcs };
2063 
2064 /* console_lock is held (except via vc_init()) */
2065 static void reset_terminal(struct vc_data *vc, int do_clear)
2066 {
2067 	unsigned int i;
2068 
2069 	vc->vc_top		= 0;
2070 	vc->vc_bottom		= vc->vc_rows;
2071 	vc->vc_state		= ESnormal;
2072 	vc->vc_priv		= EPecma;
2073 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
2074 	vc->state.Gx_charset[0]	= LAT1_MAP;
2075 	vc->state.Gx_charset[1]	= GRAF_MAP;
2076 	vc->state.charset	= 0;
2077 	vc->vc_need_wrap	= 0;
2078 	vc->vc_report_mouse	= 0;
2079 	vc->vc_utf              = default_utf8;
2080 	vc->vc_utf_count	= 0;
2081 
2082 	vc->vc_disp_ctrl	= 0;
2083 	vc->vc_toggle_meta	= 0;
2084 
2085 	vc->vc_decscnm		= 0;
2086 	vc->vc_decom		= 0;
2087 	vc->vc_decawm		= 1;
2088 	vc->vc_deccm		= global_cursor_default;
2089 	vc->vc_decim		= 0;
2090 
2091 	vt_reset_keyboard(vc->vc_num);
2092 
2093 	vc->vc_cursor_type = cur_default;
2094 	vc->vc_complement_mask = vc->vc_s_complement_mask;
2095 
2096 	default_attr(vc);
2097 	update_attr(vc);
2098 
2099 	bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2100 	for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
2101 		set_bit(i, vc->vc_tab_stop);
2102 
2103 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2104 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2105 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2106 
2107 	gotoxy(vc, 0, 0);
2108 	save_cur(vc);
2109 	if (do_clear)
2110 	    csi_J(vc, 2);
2111 }
2112 
2113 static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
2114 {
2115 	unsigned char *charset = &vc->state.Gx_charset[which];
2116 
2117 	switch (c) {
2118 	case '0':
2119 		*charset = GRAF_MAP;
2120 		break;
2121 	case 'B':
2122 		*charset = LAT1_MAP;
2123 		break;
2124 	case 'U':
2125 		*charset = IBMPC_MAP;
2126 		break;
2127 	case 'K':
2128 		*charset = USER_MAP;
2129 		break;
2130 	}
2131 
2132 	if (vc->state.charset == which)
2133 		vc->vc_translate = set_translate(*charset, vc);
2134 }
2135 
2136 /* is this state an ANSI control string? */
2137 static bool ansi_control_string(unsigned int state)
2138 {
2139 	if (state == ESosc || state == ESapc || state == ESpm || state == ESdcs)
2140 		return true;
2141 	return false;
2142 }
2143 
2144 /* console_lock is held */
2145 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2146 {
2147 	/*
2148 	 *  Control characters can be used in the _middle_
2149 	 *  of an escape sequence, aside from ANSI control strings.
2150 	 */
2151 	if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
2152 		return;
2153 	switch (c) {
2154 	case 0:
2155 		return;
2156 	case 7:
2157 		if (ansi_control_string(vc->vc_state))
2158 			vc->vc_state = ESnormal;
2159 		else if (vc->vc_bell_duration)
2160 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2161 		return;
2162 	case 8:
2163 		bs(vc);
2164 		return;
2165 	case 9:
2166 		vc->vc_pos -= (vc->state.x << 1);
2167 
2168 		vc->state.x = find_next_bit(vc->vc_tab_stop,
2169 				min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2170 				vc->state.x + 1);
2171 		if (vc->state.x >= VC_TABSTOPS_COUNT)
2172 			vc->state.x = vc->vc_cols - 1;
2173 
2174 		vc->vc_pos += (vc->state.x << 1);
2175 		notify_write(vc, '\t');
2176 		return;
2177 	case 10: case 11: case 12:
2178 		lf(vc);
2179 		if (!is_kbd(vc, lnm))
2180 			return;
2181 		fallthrough;
2182 	case 13:
2183 		cr(vc);
2184 		return;
2185 	case 14:
2186 		vc->state.charset = 1;
2187 		vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2188 		vc->vc_disp_ctrl = 1;
2189 		return;
2190 	case 15:
2191 		vc->state.charset = 0;
2192 		vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2193 		vc->vc_disp_ctrl = 0;
2194 		return;
2195 	case 24: case 26:
2196 		vc->vc_state = ESnormal;
2197 		return;
2198 	case 27:
2199 		vc->vc_state = ESesc;
2200 		return;
2201 	case 127:
2202 		del(vc);
2203 		return;
2204 	case 128+27:
2205 		vc->vc_state = ESsquare;
2206 		return;
2207 	}
2208 	switch(vc->vc_state) {
2209 	case ESesc:
2210 		vc->vc_state = ESnormal;
2211 		switch (c) {
2212 		case '[':
2213 			vc->vc_state = ESsquare;
2214 			return;
2215 		case ']':
2216 			vc->vc_state = ESnonstd;
2217 			return;
2218 		case '_':
2219 			vc->vc_state = ESapc;
2220 			return;
2221 		case '^':
2222 			vc->vc_state = ESpm;
2223 			return;
2224 		case '%':
2225 			vc->vc_state = ESpercent;
2226 			return;
2227 		case 'E':
2228 			cr(vc);
2229 			lf(vc);
2230 			return;
2231 		case 'M':
2232 			ri(vc);
2233 			return;
2234 		case 'D':
2235 			lf(vc);
2236 			return;
2237 		case 'H':
2238 			if (vc->state.x < VC_TABSTOPS_COUNT)
2239 				set_bit(vc->state.x, vc->vc_tab_stop);
2240 			return;
2241 		case 'P':
2242 			vc->vc_state = ESdcs;
2243 			return;
2244 		case 'Z':
2245 			respond_ID(tty);
2246 			return;
2247 		case '7':
2248 			save_cur(vc);
2249 			return;
2250 		case '8':
2251 			restore_cur(vc);
2252 			return;
2253 		case '(':
2254 			vc->vc_state = ESsetG0;
2255 			return;
2256 		case ')':
2257 			vc->vc_state = ESsetG1;
2258 			return;
2259 		case '#':
2260 			vc->vc_state = EShash;
2261 			return;
2262 		case 'c':
2263 			reset_terminal(vc, 1);
2264 			return;
2265 		case '>':  /* Numeric keypad */
2266 			clr_kbd(vc, kbdapplic);
2267 			return;
2268 		case '=':  /* Appl. keypad */
2269 			set_kbd(vc, kbdapplic);
2270 			return;
2271 		}
2272 		return;
2273 	case ESnonstd:
2274 		if (c=='P') {   /* palette escape sequence */
2275 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2276 				vc->vc_par[vc->vc_npar] = 0;
2277 			vc->vc_npar = 0;
2278 			vc->vc_state = ESpalette;
2279 			return;
2280 		} else if (c=='R') {   /* reset palette */
2281 			reset_palette(vc);
2282 			vc->vc_state = ESnormal;
2283 		} else if (c>='0' && c<='9')
2284 			vc->vc_state = ESosc;
2285 		else
2286 			vc->vc_state = ESnormal;
2287 		return;
2288 	case ESpalette:
2289 		if (isxdigit(c)) {
2290 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2291 			if (vc->vc_npar == 7) {
2292 				int i = vc->vc_par[0] * 3, j = 1;
2293 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2294 				vc->vc_palette[i++] += vc->vc_par[j++];
2295 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2296 				vc->vc_palette[i++] += vc->vc_par[j++];
2297 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2298 				vc->vc_palette[i] += vc->vc_par[j];
2299 				set_palette(vc);
2300 				vc->vc_state = ESnormal;
2301 			}
2302 		} else
2303 			vc->vc_state = ESnormal;
2304 		return;
2305 	case ESsquare:
2306 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2307 			vc->vc_par[vc->vc_npar] = 0;
2308 		vc->vc_npar = 0;
2309 		vc->vc_state = ESgetpars;
2310 		if (c == '[') { /* Function key */
2311 			vc->vc_state=ESfunckey;
2312 			return;
2313 		}
2314 		switch (c) {
2315 		case '?':
2316 			vc->vc_priv = EPdec;
2317 			return;
2318 		case '>':
2319 			vc->vc_priv = EPgt;
2320 			return;
2321 		case '=':
2322 			vc->vc_priv = EPeq;
2323 			return;
2324 		case '<':
2325 			vc->vc_priv = EPlt;
2326 			return;
2327 		}
2328 		vc->vc_priv = EPecma;
2329 		fallthrough;
2330 	case ESgetpars:
2331 		if (c == ';' && vc->vc_npar < NPAR - 1) {
2332 			vc->vc_npar++;
2333 			return;
2334 		} else if (c>='0' && c<='9') {
2335 			vc->vc_par[vc->vc_npar] *= 10;
2336 			vc->vc_par[vc->vc_npar] += c - '0';
2337 			return;
2338 		}
2339 		if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2340 			vc->vc_state = EScsiignore;
2341 			return;
2342 		}
2343 		vc->vc_state = ESnormal;
2344 		switch(c) {
2345 		case 'h':
2346 			if (vc->vc_priv <= EPdec)
2347 				set_mode(vc, 1);
2348 			return;
2349 		case 'l':
2350 			if (vc->vc_priv <= EPdec)
2351 				set_mode(vc, 0);
2352 			return;
2353 		case 'c':
2354 			if (vc->vc_priv == EPdec) {
2355 				if (vc->vc_par[0])
2356 					vc->vc_cursor_type =
2357 						CUR_MAKE(vc->vc_par[0],
2358 							 vc->vc_par[1],
2359 							 vc->vc_par[2]);
2360 				else
2361 					vc->vc_cursor_type = cur_default;
2362 				return;
2363 			}
2364 			break;
2365 		case 'm':
2366 			if (vc->vc_priv == EPdec) {
2367 				clear_selection();
2368 				if (vc->vc_par[0])
2369 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2370 				else
2371 					vc->vc_complement_mask = vc->vc_s_complement_mask;
2372 				return;
2373 			}
2374 			break;
2375 		case 'n':
2376 			if (vc->vc_priv == EPecma) {
2377 				if (vc->vc_par[0] == 5)
2378 					status_report(tty);
2379 				else if (vc->vc_par[0] == 6)
2380 					cursor_report(vc, tty);
2381 			}
2382 			return;
2383 		}
2384 		if (vc->vc_priv != EPecma) {
2385 			vc->vc_priv = EPecma;
2386 			return;
2387 		}
2388 		switch(c) {
2389 		case 'G': case '`':
2390 			if (vc->vc_par[0])
2391 				vc->vc_par[0]--;
2392 			gotoxy(vc, vc->vc_par[0], vc->state.y);
2393 			return;
2394 		case 'A':
2395 			if (!vc->vc_par[0])
2396 				vc->vc_par[0]++;
2397 			gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2398 			return;
2399 		case 'B': case 'e':
2400 			if (!vc->vc_par[0])
2401 				vc->vc_par[0]++;
2402 			gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2403 			return;
2404 		case 'C': case 'a':
2405 			if (!vc->vc_par[0])
2406 				vc->vc_par[0]++;
2407 			gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2408 			return;
2409 		case 'D':
2410 			if (!vc->vc_par[0])
2411 				vc->vc_par[0]++;
2412 			gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2413 			return;
2414 		case 'E':
2415 			if (!vc->vc_par[0])
2416 				vc->vc_par[0]++;
2417 			gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2418 			return;
2419 		case 'F':
2420 			if (!vc->vc_par[0])
2421 				vc->vc_par[0]++;
2422 			gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2423 			return;
2424 		case 'd':
2425 			if (vc->vc_par[0])
2426 				vc->vc_par[0]--;
2427 			gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2428 			return;
2429 		case 'H': case 'f':
2430 			if (vc->vc_par[0])
2431 				vc->vc_par[0]--;
2432 			if (vc->vc_par[1])
2433 				vc->vc_par[1]--;
2434 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2435 			return;
2436 		case 'J':
2437 			csi_J(vc, vc->vc_par[0]);
2438 			return;
2439 		case 'K':
2440 			csi_K(vc, vc->vc_par[0]);
2441 			return;
2442 		case 'L':
2443 			csi_L(vc, vc->vc_par[0]);
2444 			return;
2445 		case 'M':
2446 			csi_M(vc, vc->vc_par[0]);
2447 			return;
2448 		case 'P':
2449 			csi_P(vc, vc->vc_par[0]);
2450 			return;
2451 		case 'c':
2452 			if (!vc->vc_par[0])
2453 				respond_ID(tty);
2454 			return;
2455 		case 'g':
2456 			if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2457 				set_bit(vc->state.x, vc->vc_tab_stop);
2458 			else if (vc->vc_par[0] == 3)
2459 				bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2460 			return;
2461 		case 'm':
2462 			csi_m(vc);
2463 			return;
2464 		case 'q': /* DECLL - but only 3 leds */
2465 			/* map 0,1,2,3 to 0,1,2,4 */
2466 			if (vc->vc_par[0] < 4)
2467 				vt_set_led_state(vc->vc_num,
2468 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2469 			return;
2470 		case 'r':
2471 			if (!vc->vc_par[0])
2472 				vc->vc_par[0]++;
2473 			if (!vc->vc_par[1])
2474 				vc->vc_par[1] = vc->vc_rows;
2475 			/* Minimum allowed region is 2 lines */
2476 			if (vc->vc_par[0] < vc->vc_par[1] &&
2477 			    vc->vc_par[1] <= vc->vc_rows) {
2478 				vc->vc_top = vc->vc_par[0] - 1;
2479 				vc->vc_bottom = vc->vc_par[1];
2480 				gotoxay(vc, 0, 0);
2481 			}
2482 			return;
2483 		case 's':
2484 			save_cur(vc);
2485 			return;
2486 		case 'u':
2487 			restore_cur(vc);
2488 			return;
2489 		case 'X':
2490 			csi_X(vc, vc->vc_par[0]);
2491 			return;
2492 		case '@':
2493 			csi_at(vc, vc->vc_par[0]);
2494 			return;
2495 		case ']': /* setterm functions */
2496 			setterm_command(vc);
2497 			return;
2498 		}
2499 		return;
2500 	case EScsiignore:
2501 		if (c >= 20 && c <= 0x3f)
2502 			return;
2503 		vc->vc_state = ESnormal;
2504 		return;
2505 	case ESpercent:
2506 		vc->vc_state = ESnormal;
2507 		switch (c) {
2508 		case '@':  /* defined in ISO 2022 */
2509 			vc->vc_utf = 0;
2510 			return;
2511 		case 'G':  /* prelim official escape code */
2512 		case '8':  /* retained for compatibility */
2513 			vc->vc_utf = 1;
2514 			return;
2515 		}
2516 		return;
2517 	case ESfunckey:
2518 		vc->vc_state = ESnormal;
2519 		return;
2520 	case EShash:
2521 		vc->vc_state = ESnormal;
2522 		if (c == '8') {
2523 			/* DEC screen alignment test. kludge :-) */
2524 			vc->vc_video_erase_char =
2525 				(vc->vc_video_erase_char & 0xff00) | 'E';
2526 			csi_J(vc, 2);
2527 			vc->vc_video_erase_char =
2528 				(vc->vc_video_erase_char & 0xff00) | ' ';
2529 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2530 		}
2531 		return;
2532 	case ESsetG0:
2533 		vc_setGx(vc, 0, c);
2534 		vc->vc_state = ESnormal;
2535 		return;
2536 	case ESsetG1:
2537 		vc_setGx(vc, 1, c);
2538 		vc->vc_state = ESnormal;
2539 		return;
2540 	case ESapc:
2541 		return;
2542 	case ESosc:
2543 		return;
2544 	case ESpm:
2545 		return;
2546 	case ESdcs:
2547 		return;
2548 	default:
2549 		vc->vc_state = ESnormal;
2550 	}
2551 }
2552 
2553 /* is_double_width() is based on the wcwidth() implementation by
2554  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2555  * Latest version: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2556  */
2557 struct interval {
2558 	uint32_t first;
2559 	uint32_t last;
2560 };
2561 
2562 static int ucs_cmp(const void *key, const void *elt)
2563 {
2564 	uint32_t ucs = *(uint32_t *)key;
2565 	struct interval e = *(struct interval *) elt;
2566 
2567 	if (ucs > e.last)
2568 		return 1;
2569 	else if (ucs < e.first)
2570 		return -1;
2571 	return 0;
2572 }
2573 
2574 static int is_double_width(uint32_t ucs)
2575 {
2576 	static const struct interval double_width[] = {
2577 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2578 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2579 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2580 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2581 	};
2582 	if (ucs < double_width[0].first ||
2583 	    ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2584 		return 0;
2585 
2586 	return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2587 			sizeof(struct interval), ucs_cmp) != NULL;
2588 }
2589 
2590 struct vc_draw_region {
2591 	unsigned long from, to;
2592 	int x;
2593 };
2594 
2595 static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
2596 {
2597 	if (draw->x < 0)
2598 		return;
2599 
2600 	vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
2601 			(u16 *)draw->to - (u16 *)draw->from, vc->state.y,
2602 			draw->x);
2603 	draw->x = -1;
2604 }
2605 
2606 static inline int vc_translate_ascii(const struct vc_data *vc, int c)
2607 {
2608 	if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
2609 		if (vc->vc_toggle_meta)
2610 			c |= 0x80;
2611 
2612 		return vc->vc_translate[c];
2613 	}
2614 
2615 	return c;
2616 }
2617 
2618 
2619 /**
2620  * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
2621  * @c: the received character, or U+FFFD for invalid sequences.
2622  */
2623 static inline int vc_sanitize_unicode(const int c)
2624 {
2625 	if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2626 		return 0xfffd;
2627 
2628 	return c;
2629 }
2630 
2631 /**
2632  * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
2633  * @vc: virtual console
2634  * @c: character to translate
2635  * @rescan: we return true if we need more (continuation) data
2636  *
2637  * @vc_utf_char is the being-constructed unicode character.
2638  * @vc_utf_count is the number of continuation bytes still expected to arrive.
2639  * @vc_npar is the number of continuation bytes arrived so far.
2640  */
2641 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
2642 {
2643 	static const u32 utf8_length_changes[] = {
2644 		0x0000007f, 0x000007ff, 0x0000ffff,
2645 		0x001fffff, 0x03ffffff, 0x7fffffff
2646 	};
2647 
2648 	/* Continuation byte received */
2649 	if ((c & 0xc0) == 0x80) {
2650 		/* Unexpected continuation byte? */
2651 		if (!vc->vc_utf_count)
2652 			return 0xfffd;
2653 
2654 		vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2655 		vc->vc_npar++;
2656 		if (--vc->vc_utf_count)
2657 			goto need_more_bytes;
2658 
2659 		/* Got a whole character */
2660 		c = vc->vc_utf_char;
2661 		/* Reject overlong sequences */
2662 		if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2663 				c > utf8_length_changes[vc->vc_npar])
2664 			return 0xfffd;
2665 
2666 		return vc_sanitize_unicode(c);
2667 	}
2668 
2669 	/* Single ASCII byte or first byte of a sequence received */
2670 	if (vc->vc_utf_count) {
2671 		/* Continuation byte expected */
2672 		*rescan = true;
2673 		vc->vc_utf_count = 0;
2674 		return 0xfffd;
2675 	}
2676 
2677 	/* Nothing to do if an ASCII byte was received */
2678 	if (c <= 0x7f)
2679 		return c;
2680 
2681 	/* First byte of a multibyte sequence received */
2682 	vc->vc_npar = 0;
2683 	if ((c & 0xe0) == 0xc0) {
2684 		vc->vc_utf_count = 1;
2685 		vc->vc_utf_char = (c & 0x1f);
2686 	} else if ((c & 0xf0) == 0xe0) {
2687 		vc->vc_utf_count = 2;
2688 		vc->vc_utf_char = (c & 0x0f);
2689 	} else if ((c & 0xf8) == 0xf0) {
2690 		vc->vc_utf_count = 3;
2691 		vc->vc_utf_char = (c & 0x07);
2692 	} else if ((c & 0xfc) == 0xf8) {
2693 		vc->vc_utf_count = 4;
2694 		vc->vc_utf_char = (c & 0x03);
2695 	} else if ((c & 0xfe) == 0xfc) {
2696 		vc->vc_utf_count = 5;
2697 		vc->vc_utf_char = (c & 0x01);
2698 	} else {
2699 		/* 254 and 255 are invalid */
2700 		return 0xfffd;
2701 	}
2702 
2703 need_more_bytes:
2704 	return -1;
2705 }
2706 
2707 static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
2708 {
2709 	/* Do no translation at all in control states */
2710 	if (vc->vc_state != ESnormal)
2711 		return *c;
2712 
2713 	if (vc->vc_utf && !vc->vc_disp_ctrl)
2714 		return *c = vc_translate_unicode(vc, *c, rescan);
2715 
2716 	/* no utf or alternate charset mode */
2717 	return vc_translate_ascii(vc, *c);
2718 }
2719 
2720 static inline unsigned char vc_invert_attr(const struct vc_data *vc)
2721 {
2722 	if (!vc->vc_can_do_color)
2723 		return vc->vc_attr ^ 0x08;
2724 
2725 	if (vc->vc_hi_font_mask == 0x100)
2726 		return   (vc->vc_attr & 0x11) |
2727 			((vc->vc_attr & 0xe0) >> 4) |
2728 			((vc->vc_attr & 0x0e) << 4);
2729 
2730 	return   (vc->vc_attr & 0x88) |
2731 		((vc->vc_attr & 0x70) >> 4) |
2732 		((vc->vc_attr & 0x07) << 4);
2733 }
2734 
2735 static bool vc_is_control(struct vc_data *vc, int tc, int c)
2736 {
2737 	/*
2738 	 * A bitmap for codes <32. A bit of 1 indicates that the code
2739 	 * corresponding to that bit number invokes some special action (such
2740 	 * as cursor movement) and should not be displayed as a glyph unless
2741 	 * the disp_ctrl mode is explicitly enabled.
2742 	 */
2743 	static const u32 CTRL_ACTION = 0x0d00ff81;
2744 	/* Cannot be overridden by disp_ctrl */
2745 	static const u32 CTRL_ALWAYS = 0x0800f501;
2746 
2747 	if (vc->vc_state != ESnormal)
2748 		return true;
2749 
2750 	if (!tc)
2751 		return true;
2752 
2753 	/*
2754 	 * If the original code was a control character we only allow a glyph
2755 	 * to be displayed if the code is not normally used (such as for cursor
2756 	 * movement) or if the disp_ctrl mode has been explicitly enabled.
2757 	 * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
2758 	 * displayed as control characters, as the console would be pretty
2759 	 * useless without them; to display an arbitrary font position use the
2760 	 * direct-to-font zone in UTF-8 mode.
2761 	 */
2762 	if (c < 32) {
2763 		if (vc->vc_disp_ctrl)
2764 			return CTRL_ALWAYS & BIT(c);
2765 		else
2766 			return vc->vc_utf || (CTRL_ACTION & BIT(c));
2767 	}
2768 
2769 	if (c == 127 && !vc->vc_disp_ctrl)
2770 		return true;
2771 
2772 	if (c == 128 + 27)
2773 		return true;
2774 
2775 	return false;
2776 }
2777 
2778 static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
2779 		struct vc_draw_region *draw)
2780 {
2781 	int next_c;
2782 	unsigned char vc_attr = vc->vc_attr;
2783 	u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
2784 	u8 width = 1;
2785 	bool inverse = false;
2786 
2787 	if (vc->vc_utf && !vc->vc_disp_ctrl) {
2788 		if (is_double_width(c))
2789 			width = 2;
2790 	}
2791 
2792 	/* Now try to find out how to display it */
2793 	tc = conv_uni_to_pc(vc, tc);
2794 	if (tc & ~charmask) {
2795 		if (tc == -1 || tc == -2)
2796 			return -1; /* nothing to display */
2797 
2798 		/* Glyph not found */
2799 		if ((!vc->vc_utf || vc->vc_disp_ctrl || c < 128) &&
2800 				!(c & ~charmask)) {
2801 			/*
2802 			 * In legacy mode use the glyph we get by a 1:1
2803 			 * mapping.
2804 			 * This would make absolutely no sense with Unicode in
2805 			 * mind, but do this for ASCII characters since a font
2806 			 * may lack Unicode mapping info and we don't want to
2807 			 * end up with having question marks only.
2808 			 */
2809 			tc = c;
2810 		} else {
2811 			/*
2812 			 * Display U+FFFD. If it's not found, display an inverse
2813 			 * question mark.
2814 			 */
2815 			tc = conv_uni_to_pc(vc, 0xfffd);
2816 			if (tc < 0) {
2817 				inverse = true;
2818 				tc = conv_uni_to_pc(vc, '?');
2819 				if (tc < 0)
2820 					tc = '?';
2821 
2822 				vc_attr = vc_invert_attr(vc);
2823 				con_flush(vc, draw);
2824 			}
2825 		}
2826 	}
2827 
2828 	next_c = c;
2829 	while (1) {
2830 		if (vc->vc_need_wrap || vc->vc_decim)
2831 			con_flush(vc, draw);
2832 		if (vc->vc_need_wrap) {
2833 			cr(vc);
2834 			lf(vc);
2835 		}
2836 		if (vc->vc_decim)
2837 			insert_char(vc, 1);
2838 		vc_uniscr_putc(vc, next_c);
2839 
2840 		if (himask)
2841 			tc = ((tc & 0x100) ? himask : 0) |
2842 			      (tc &  0xff);
2843 		tc |= (vc_attr << 8) & ~himask;
2844 
2845 		scr_writew(tc, (u16 *)vc->vc_pos);
2846 
2847 		if (con_should_update(vc) && draw->x < 0) {
2848 			draw->x = vc->state.x;
2849 			draw->from = vc->vc_pos;
2850 		}
2851 		if (vc->state.x == vc->vc_cols - 1) {
2852 			vc->vc_need_wrap = vc->vc_decawm;
2853 			draw->to = vc->vc_pos + 2;
2854 		} else {
2855 			vc->state.x++;
2856 			draw->to = (vc->vc_pos += 2);
2857 		}
2858 
2859 		if (!--width)
2860 			break;
2861 
2862 		/* A space is printed in the second column */
2863 		tc = conv_uni_to_pc(vc, ' ');
2864 		if (tc < 0)
2865 			tc = ' ';
2866 		next_c = ' ';
2867 	}
2868 	notify_write(vc, c);
2869 
2870 	if (inverse)
2871 		con_flush(vc, draw);
2872 
2873 	return 0;
2874 }
2875 
2876 /* acquires console_lock */
2877 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2878 {
2879 	struct vc_draw_region draw = {
2880 		.x = -1,
2881 	};
2882 	int c, tc, n = 0;
2883 	unsigned int currcons;
2884 	struct vc_data *vc;
2885 	struct vt_notifier_param param;
2886 	bool rescan;
2887 
2888 	if (in_interrupt())
2889 		return count;
2890 
2891 	console_lock();
2892 	vc = tty->driver_data;
2893 	if (vc == NULL) {
2894 		pr_err("vt: argh, driver_data is NULL !\n");
2895 		console_unlock();
2896 		return 0;
2897 	}
2898 
2899 	currcons = vc->vc_num;
2900 	if (!vc_cons_allocated(currcons)) {
2901 		/* could this happen? */
2902 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2903 		console_unlock();
2904 		return 0;
2905 	}
2906 
2907 
2908 	/* undraw cursor first */
2909 	if (con_is_fg(vc))
2910 		hide_cursor(vc);
2911 
2912 	param.vc = vc;
2913 
2914 	while (!tty->flow.stopped && count) {
2915 		int orig = *buf;
2916 		buf++;
2917 		n++;
2918 		count--;
2919 rescan_last_byte:
2920 		c = orig;
2921 		rescan = false;
2922 
2923 		tc = vc_translate(vc, &c, &rescan);
2924 		if (tc == -1)
2925 			continue;
2926 
2927 		param.c = tc;
2928 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2929 					&param) == NOTIFY_STOP)
2930 			continue;
2931 
2932 		if (vc_is_control(vc, tc, c)) {
2933 			con_flush(vc, &draw);
2934 			do_con_trol(tty, vc, orig);
2935 			continue;
2936 		}
2937 
2938 		if (vc_con_write_normal(vc, tc, c, &draw) < 0)
2939 			continue;
2940 
2941 		if (rescan)
2942 			goto rescan_last_byte;
2943 	}
2944 	con_flush(vc, &draw);
2945 	vc_uniscr_debug_check(vc);
2946 	console_conditional_schedule();
2947 	notify_update(vc);
2948 	console_unlock();
2949 	return n;
2950 }
2951 
2952 /*
2953  * This is the console switching callback.
2954  *
2955  * Doing console switching in a process context allows
2956  * us to do the switches asynchronously (needed when we want
2957  * to switch due to a keyboard interrupt).  Synchronization
2958  * with other console code and prevention of re-entrancy is
2959  * ensured with console_lock.
2960  */
2961 static void console_callback(struct work_struct *ignored)
2962 {
2963 	console_lock();
2964 
2965 	if (want_console >= 0) {
2966 		if (want_console != fg_console &&
2967 		    vc_cons_allocated(want_console)) {
2968 			hide_cursor(vc_cons[fg_console].d);
2969 			change_console(vc_cons[want_console].d);
2970 			/* we only changed when the console had already
2971 			   been allocated - a new console is not created
2972 			   in an interrupt routine */
2973 		}
2974 		want_console = -1;
2975 	}
2976 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2977 		do_poke_blanked_console = 0;
2978 		poke_blanked_console();
2979 	}
2980 	if (scrollback_delta) {
2981 		struct vc_data *vc = vc_cons[fg_console].d;
2982 		clear_selection();
2983 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2984 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2985 		scrollback_delta = 0;
2986 	}
2987 	if (blank_timer_expired) {
2988 		do_blank_screen(0);
2989 		blank_timer_expired = 0;
2990 	}
2991 	notify_update(vc_cons[fg_console].d);
2992 
2993 	console_unlock();
2994 }
2995 
2996 int set_console(int nr)
2997 {
2998 	struct vc_data *vc = vc_cons[fg_console].d;
2999 
3000 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
3001 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
3002 
3003 		/*
3004 		 * Console switch will fail in console_callback() or
3005 		 * change_console() so there is no point scheduling
3006 		 * the callback
3007 		 *
3008 		 * Existing set_console() users don't check the return
3009 		 * value so this shouldn't break anything
3010 		 */
3011 		return -EINVAL;
3012 	}
3013 
3014 	want_console = nr;
3015 	schedule_console_callback();
3016 
3017 	return 0;
3018 }
3019 
3020 struct tty_driver *console_driver;
3021 
3022 #ifdef CONFIG_VT_CONSOLE
3023 
3024 /**
3025  * vt_kmsg_redirect() - Sets/gets the kernel message console
3026  * @new:	The new virtual terminal number or -1 if the console should stay
3027  * 		unchanged
3028  *
3029  * By default, the kernel messages are always printed on the current virtual
3030  * console. However, the user may modify that default with the
3031  * TIOCL_SETKMSGREDIRECT ioctl call.
3032  *
3033  * This function sets the kernel message console to be @new. It returns the old
3034  * virtual console number. The virtual terminal number 0 (both as parameter and
3035  * return value) means no redirection (i.e. always printed on the currently
3036  * active console).
3037  *
3038  * The parameter -1 means that only the current console is returned, but the
3039  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
3040  * case to make the code more understandable.
3041  *
3042  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
3043  * the parameter and always returns 0.
3044  */
3045 int vt_kmsg_redirect(int new)
3046 {
3047 	static int kmsg_con;
3048 
3049 	if (new != -1)
3050 		return xchg(&kmsg_con, new);
3051 	else
3052 		return kmsg_con;
3053 }
3054 
3055 /*
3056  *	Console on virtual terminal
3057  *
3058  * The console must be locked when we get here.
3059  */
3060 
3061 static void vt_console_print(struct console *co, const char *b, unsigned count)
3062 {
3063 	struct vc_data *vc = vc_cons[fg_console].d;
3064 	unsigned char c;
3065 	static DEFINE_SPINLOCK(printing_lock);
3066 	const ushort *start;
3067 	ushort start_x, cnt;
3068 	int kmsg_console;
3069 
3070 	/* console busy or not yet initialized */
3071 	if (!printable)
3072 		return;
3073 	if (!spin_trylock(&printing_lock))
3074 		return;
3075 
3076 	kmsg_console = vt_get_kmsg_redirect();
3077 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
3078 		vc = vc_cons[kmsg_console - 1].d;
3079 
3080 	if (!vc_cons_allocated(fg_console)) {
3081 		/* impossible */
3082 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
3083 		goto quit;
3084 	}
3085 
3086 	if (vc->vc_mode != KD_TEXT)
3087 		goto quit;
3088 
3089 	/* undraw cursor first */
3090 	if (con_is_fg(vc))
3091 		hide_cursor(vc);
3092 
3093 	start = (ushort *)vc->vc_pos;
3094 	start_x = vc->state.x;
3095 	cnt = 0;
3096 	while (count--) {
3097 		c = *b++;
3098 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
3099 			if (cnt && con_is_visible(vc))
3100 				vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3101 			cnt = 0;
3102 			if (c == 8) {		/* backspace */
3103 				bs(vc);
3104 				start = (ushort *)vc->vc_pos;
3105 				start_x = vc->state.x;
3106 				continue;
3107 			}
3108 			if (c != 13)
3109 				lf(vc);
3110 			cr(vc);
3111 			start = (ushort *)vc->vc_pos;
3112 			start_x = vc->state.x;
3113 			if (c == 10 || c == 13)
3114 				continue;
3115 		}
3116 		vc_uniscr_putc(vc, c);
3117 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3118 		notify_write(vc, c);
3119 		cnt++;
3120 		if (vc->state.x == vc->vc_cols - 1) {
3121 			vc->vc_need_wrap = 1;
3122 		} else {
3123 			vc->vc_pos += 2;
3124 			vc->state.x++;
3125 		}
3126 	}
3127 	if (cnt && con_is_visible(vc))
3128 		vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3129 	set_cursor(vc);
3130 	notify_update(vc);
3131 
3132 quit:
3133 	spin_unlock(&printing_lock);
3134 }
3135 
3136 static struct tty_driver *vt_console_device(struct console *c, int *index)
3137 {
3138 	*index = c->index ? c->index-1 : fg_console;
3139 	return console_driver;
3140 }
3141 
3142 static struct console vt_console_driver = {
3143 	.name		= "tty",
3144 	.write		= vt_console_print,
3145 	.device		= vt_console_device,
3146 	.unblank	= unblank_screen,
3147 	.flags		= CON_PRINTBUFFER,
3148 	.index		= -1,
3149 };
3150 #endif
3151 
3152 /*
3153  *	Handling of Linux-specific VC ioctls
3154  */
3155 
3156 /*
3157  * Generally a bit racy with respect to console_lock();.
3158  *
3159  * There are some functions which don't need it.
3160  *
3161  * There are some functions which can sleep for arbitrary periods
3162  * (paste_selection) but we don't need the lock there anyway.
3163  *
3164  * set_selection_user has locking, and definitely needs it
3165  */
3166 
3167 int tioclinux(struct tty_struct *tty, unsigned long arg)
3168 {
3169 	char type, data;
3170 	char __user *p = (char __user *)arg;
3171 	int lines;
3172 	int ret;
3173 
3174 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3175 		return -EPERM;
3176 	if (get_user(type, p))
3177 		return -EFAULT;
3178 	ret = 0;
3179 
3180 	switch (type)
3181 	{
3182 		case TIOCL_SETSEL:
3183 			ret = set_selection_user((struct tiocl_selection
3184 						 __user *)(p+1), tty);
3185 			break;
3186 		case TIOCL_PASTESEL:
3187 			ret = paste_selection(tty);
3188 			break;
3189 		case TIOCL_UNBLANKSCREEN:
3190 			console_lock();
3191 			unblank_screen();
3192 			console_unlock();
3193 			break;
3194 		case TIOCL_SELLOADLUT:
3195 			console_lock();
3196 			ret = sel_loadlut(p);
3197 			console_unlock();
3198 			break;
3199 		case TIOCL_GETSHIFTSTATE:
3200 
3201 	/*
3202 	 * Make it possible to react to Shift+Mousebutton.
3203 	 * Note that 'shift_state' is an undocumented
3204 	 * kernel-internal variable; programs not closely
3205 	 * related to the kernel should not use this.
3206 	 */
3207 			data = vt_get_shift_state();
3208 			ret = put_user(data, p);
3209 			break;
3210 		case TIOCL_GETMOUSEREPORTING:
3211 			console_lock();	/* May be overkill */
3212 			data = mouse_reporting();
3213 			console_unlock();
3214 			ret = put_user(data, p);
3215 			break;
3216 		case TIOCL_SETVESABLANK:
3217 			console_lock();
3218 			ret = set_vesa_blanking(p);
3219 			console_unlock();
3220 			break;
3221 		case TIOCL_GETKMSGREDIRECT:
3222 			data = vt_get_kmsg_redirect();
3223 			ret = put_user(data, p);
3224 			break;
3225 		case TIOCL_SETKMSGREDIRECT:
3226 			if (!capable(CAP_SYS_ADMIN)) {
3227 				ret = -EPERM;
3228 			} else {
3229 				if (get_user(data, p+1))
3230 					ret = -EFAULT;
3231 				else
3232 					vt_kmsg_redirect(data);
3233 			}
3234 			break;
3235 		case TIOCL_GETFGCONSOLE:
3236 			/* No locking needed as this is a transiently
3237 			   correct return anyway if the caller hasn't
3238 			   disabled switching */
3239 			ret = fg_console;
3240 			break;
3241 		case TIOCL_SCROLLCONSOLE:
3242 			if (get_user(lines, (s32 __user *)(p+4))) {
3243 				ret = -EFAULT;
3244 			} else {
3245 				/* Need the console lock here. Note that lots
3246 				   of other calls need fixing before the lock
3247 				   is actually useful ! */
3248 				console_lock();
3249 				scrollfront(vc_cons[fg_console].d, lines);
3250 				console_unlock();
3251 				ret = 0;
3252 			}
3253 			break;
3254 		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
3255 			console_lock();
3256 			ignore_poke = 1;
3257 			do_blank_screen(0);
3258 			console_unlock();
3259 			break;
3260 		case TIOCL_BLANKEDSCREEN:
3261 			ret = console_blanked;
3262 			break;
3263 		default:
3264 			ret = -EINVAL;
3265 			break;
3266 	}
3267 	return ret;
3268 }
3269 
3270 /*
3271  * /dev/ttyN handling
3272  */
3273 
3274 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3275 {
3276 	int	retval;
3277 
3278 	retval = do_con_write(tty, buf, count);
3279 	con_flush_chars(tty);
3280 
3281 	return retval;
3282 }
3283 
3284 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3285 {
3286 	return do_con_write(tty, &ch, 1);
3287 }
3288 
3289 static unsigned int con_write_room(struct tty_struct *tty)
3290 {
3291 	if (tty->flow.stopped)
3292 		return 0;
3293 	return 32768;		/* No limit, really; we're not buffering */
3294 }
3295 
3296 /*
3297  * con_throttle and con_unthrottle are only used for
3298  * paste_selection(), which has to stuff in a large number of
3299  * characters...
3300  */
3301 static void con_throttle(struct tty_struct *tty)
3302 {
3303 }
3304 
3305 static void con_unthrottle(struct tty_struct *tty)
3306 {
3307 	struct vc_data *vc = tty->driver_data;
3308 
3309 	wake_up_interruptible(&vc->paste_wait);
3310 }
3311 
3312 /*
3313  * Turn the Scroll-Lock LED on when the tty is stopped
3314  */
3315 static void con_stop(struct tty_struct *tty)
3316 {
3317 	int console_num;
3318 	if (!tty)
3319 		return;
3320 	console_num = tty->index;
3321 	if (!vc_cons_allocated(console_num))
3322 		return;
3323 	vt_kbd_con_stop(console_num);
3324 }
3325 
3326 /*
3327  * Turn the Scroll-Lock LED off when the console is started
3328  */
3329 static void con_start(struct tty_struct *tty)
3330 {
3331 	int console_num;
3332 	if (!tty)
3333 		return;
3334 	console_num = tty->index;
3335 	if (!vc_cons_allocated(console_num))
3336 		return;
3337 	vt_kbd_con_start(console_num);
3338 }
3339 
3340 static void con_flush_chars(struct tty_struct *tty)
3341 {
3342 	struct vc_data *vc;
3343 
3344 	if (in_interrupt())	/* from flush_to_ldisc */
3345 		return;
3346 
3347 	/* if we race with con_close(), vt may be null */
3348 	console_lock();
3349 	vc = tty->driver_data;
3350 	if (vc)
3351 		set_cursor(vc);
3352 	console_unlock();
3353 }
3354 
3355 /*
3356  * Allocate the console screen memory.
3357  */
3358 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3359 {
3360 	unsigned int currcons = tty->index;
3361 	struct vc_data *vc;
3362 	int ret;
3363 
3364 	console_lock();
3365 	ret = vc_allocate(currcons);
3366 	if (ret)
3367 		goto unlock;
3368 
3369 	vc = vc_cons[currcons].d;
3370 
3371 	/* Still being freed */
3372 	if (vc->port.tty) {
3373 		ret = -ERESTARTSYS;
3374 		goto unlock;
3375 	}
3376 
3377 	ret = tty_port_install(&vc->port, driver, tty);
3378 	if (ret)
3379 		goto unlock;
3380 
3381 	tty->driver_data = vc;
3382 	vc->port.tty = tty;
3383 	tty_port_get(&vc->port);
3384 
3385 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3386 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3387 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3388 	}
3389 	if (vc->vc_utf)
3390 		tty->termios.c_iflag |= IUTF8;
3391 	else
3392 		tty->termios.c_iflag &= ~IUTF8;
3393 unlock:
3394 	console_unlock();
3395 	return ret;
3396 }
3397 
3398 static int con_open(struct tty_struct *tty, struct file *filp)
3399 {
3400 	/* everything done in install */
3401 	return 0;
3402 }
3403 
3404 
3405 static void con_close(struct tty_struct *tty, struct file *filp)
3406 {
3407 	/* Nothing to do - we defer to shutdown */
3408 }
3409 
3410 static void con_shutdown(struct tty_struct *tty)
3411 {
3412 	struct vc_data *vc = tty->driver_data;
3413 	BUG_ON(vc == NULL);
3414 	console_lock();
3415 	vc->port.tty = NULL;
3416 	console_unlock();
3417 }
3418 
3419 static void con_cleanup(struct tty_struct *tty)
3420 {
3421 	struct vc_data *vc = tty->driver_data;
3422 
3423 	tty_port_put(&vc->port);
3424 }
3425 
3426 static int default_color           = 7; /* white */
3427 static int default_italic_color    = 2; // green (ASCII)
3428 static int default_underline_color = 3; // cyan (ASCII)
3429 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3430 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3431 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3432 
3433 static void vc_init(struct vc_data *vc, unsigned int rows,
3434 		    unsigned int cols, int do_clear)
3435 {
3436 	int j, k ;
3437 
3438 	vc->vc_cols = cols;
3439 	vc->vc_rows = rows;
3440 	vc->vc_size_row = cols << 1;
3441 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3442 
3443 	set_origin(vc);
3444 	vc->vc_pos = vc->vc_origin;
3445 	reset_vc(vc);
3446 	for (j=k=0; j<16; j++) {
3447 		vc->vc_palette[k++] = default_red[j] ;
3448 		vc->vc_palette[k++] = default_grn[j] ;
3449 		vc->vc_palette[k++] = default_blu[j] ;
3450 	}
3451 	vc->vc_def_color       = default_color;
3452 	vc->vc_ulcolor         = default_underline_color;
3453 	vc->vc_itcolor         = default_italic_color;
3454 	vc->vc_halfcolor       = 0x08;   /* grey */
3455 	init_waitqueue_head(&vc->paste_wait);
3456 	reset_terminal(vc, do_clear);
3457 }
3458 
3459 /*
3460  * This routine initializes console interrupts, and does nothing
3461  * else. If you want the screen to clear, call tty_write with
3462  * the appropriate escape-sequence.
3463  */
3464 
3465 static int __init con_init(void)
3466 {
3467 	const char *display_desc = NULL;
3468 	struct vc_data *vc;
3469 	unsigned int currcons = 0, i;
3470 
3471 	console_lock();
3472 
3473 	if (!conswitchp)
3474 		conswitchp = &dummy_con;
3475 	display_desc = conswitchp->con_startup();
3476 	if (!display_desc) {
3477 		fg_console = 0;
3478 		console_unlock();
3479 		return 0;
3480 	}
3481 
3482 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3483 		struct con_driver *con_driver = &registered_con_driver[i];
3484 
3485 		if (con_driver->con == NULL) {
3486 			con_driver->con = conswitchp;
3487 			con_driver->desc = display_desc;
3488 			con_driver->flag = CON_DRIVER_FLAG_INIT;
3489 			con_driver->first = 0;
3490 			con_driver->last = MAX_NR_CONSOLES - 1;
3491 			break;
3492 		}
3493 	}
3494 
3495 	for (i = 0; i < MAX_NR_CONSOLES; i++)
3496 		con_driver_map[i] = conswitchp;
3497 
3498 	if (blankinterval) {
3499 		blank_state = blank_normal_wait;
3500 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3501 	}
3502 
3503 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3504 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3505 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3506 		tty_port_init(&vc->port);
3507 		visual_init(vc, currcons, 1);
3508 		/* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3509 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3510 		vc_init(vc, vc->vc_rows, vc->vc_cols,
3511 			currcons || !vc->vc_sw->con_save_screen);
3512 	}
3513 	currcons = fg_console = 0;
3514 	master_display_fg = vc = vc_cons[currcons].d;
3515 	set_origin(vc);
3516 	save_screen(vc);
3517 	gotoxy(vc, vc->state.x, vc->state.y);
3518 	csi_J(vc, 0);
3519 	update_screen(vc);
3520 	pr_info("Console: %s %s %dx%d\n",
3521 		vc->vc_can_do_color ? "colour" : "mono",
3522 		display_desc, vc->vc_cols, vc->vc_rows);
3523 	printable = 1;
3524 
3525 	console_unlock();
3526 
3527 #ifdef CONFIG_VT_CONSOLE
3528 	register_console(&vt_console_driver);
3529 #endif
3530 	return 0;
3531 }
3532 console_initcall(con_init);
3533 
3534 static const struct tty_operations con_ops = {
3535 	.install = con_install,
3536 	.open = con_open,
3537 	.close = con_close,
3538 	.write = con_write,
3539 	.write_room = con_write_room,
3540 	.put_char = con_put_char,
3541 	.flush_chars = con_flush_chars,
3542 	.ioctl = vt_ioctl,
3543 #ifdef CONFIG_COMPAT
3544 	.compat_ioctl = vt_compat_ioctl,
3545 #endif
3546 	.stop = con_stop,
3547 	.start = con_start,
3548 	.throttle = con_throttle,
3549 	.unthrottle = con_unthrottle,
3550 	.resize = vt_resize,
3551 	.shutdown = con_shutdown,
3552 	.cleanup = con_cleanup,
3553 };
3554 
3555 static struct cdev vc0_cdev;
3556 
3557 static ssize_t show_tty_active(struct device *dev,
3558 				struct device_attribute *attr, char *buf)
3559 {
3560 	return sprintf(buf, "tty%d\n", fg_console + 1);
3561 }
3562 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3563 
3564 static struct attribute *vt_dev_attrs[] = {
3565 	&dev_attr_active.attr,
3566 	NULL
3567 };
3568 
3569 ATTRIBUTE_GROUPS(vt_dev);
3570 
3571 int __init vty_init(const struct file_operations *console_fops)
3572 {
3573 	cdev_init(&vc0_cdev, console_fops);
3574 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3575 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3576 		panic("Couldn't register /dev/tty0 driver\n");
3577 	tty0dev = device_create_with_groups(tty_class, NULL,
3578 					    MKDEV(TTY_MAJOR, 0), NULL,
3579 					    vt_dev_groups, "tty0");
3580 	if (IS_ERR(tty0dev))
3581 		tty0dev = NULL;
3582 
3583 	vcs_init();
3584 
3585 	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3586 	if (!console_driver)
3587 		panic("Couldn't allocate console driver\n");
3588 
3589 	console_driver->name = "tty";
3590 	console_driver->name_base = 1;
3591 	console_driver->major = TTY_MAJOR;
3592 	console_driver->minor_start = 1;
3593 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3594 	console_driver->init_termios = tty_std_termios;
3595 	if (default_utf8)
3596 		console_driver->init_termios.c_iflag |= IUTF8;
3597 	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3598 	tty_set_operations(console_driver, &con_ops);
3599 	if (tty_register_driver(console_driver))
3600 		panic("Couldn't register console driver\n");
3601 	kbd_init();
3602 	console_map_init();
3603 #ifdef CONFIG_MDA_CONSOLE
3604 	mda_console_init();
3605 #endif
3606 	return 0;
3607 }
3608 
3609 #ifndef VT_SINGLE_DRIVER
3610 
3611 static struct class *vtconsole_class;
3612 
3613 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3614 			   int deflt)
3615 {
3616 	struct module *owner = csw->owner;
3617 	const char *desc = NULL;
3618 	struct con_driver *con_driver;
3619 	int i, j = -1, k = -1, retval = -ENODEV;
3620 
3621 	if (!try_module_get(owner))
3622 		return -ENODEV;
3623 
3624 	WARN_CONSOLE_UNLOCKED();
3625 
3626 	/* check if driver is registered */
3627 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3628 		con_driver = &registered_con_driver[i];
3629 
3630 		if (con_driver->con == csw) {
3631 			desc = con_driver->desc;
3632 			retval = 0;
3633 			break;
3634 		}
3635 	}
3636 
3637 	if (retval)
3638 		goto err;
3639 
3640 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3641 		csw->con_startup();
3642 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3643 	}
3644 
3645 	if (deflt) {
3646 		if (conswitchp)
3647 			module_put(conswitchp->owner);
3648 
3649 		__module_get(owner);
3650 		conswitchp = csw;
3651 	}
3652 
3653 	first = max(first, con_driver->first);
3654 	last = min(last, con_driver->last);
3655 
3656 	for (i = first; i <= last; i++) {
3657 		int old_was_color;
3658 		struct vc_data *vc = vc_cons[i].d;
3659 
3660 		if (con_driver_map[i])
3661 			module_put(con_driver_map[i]->owner);
3662 		__module_get(owner);
3663 		con_driver_map[i] = csw;
3664 
3665 		if (!vc || !vc->vc_sw)
3666 			continue;
3667 
3668 		j = i;
3669 
3670 		if (con_is_visible(vc)) {
3671 			k = i;
3672 			save_screen(vc);
3673 		}
3674 
3675 		old_was_color = vc->vc_can_do_color;
3676 		vc->vc_sw->con_deinit(vc);
3677 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3678 		visual_init(vc, i, 0);
3679 		set_origin(vc);
3680 		update_attr(vc);
3681 
3682 		/* If the console changed between mono <-> color, then
3683 		 * the attributes in the screenbuf will be wrong.  The
3684 		 * following resets all attributes to something sane.
3685 		 */
3686 		if (old_was_color != vc->vc_can_do_color)
3687 			clear_buffer_attributes(vc);
3688 	}
3689 
3690 	pr_info("Console: switching ");
3691 	if (!deflt)
3692 		pr_cont("consoles %d-%d ", first + 1, last + 1);
3693 	if (j >= 0) {
3694 		struct vc_data *vc = vc_cons[j].d;
3695 
3696 		pr_cont("to %s %s %dx%d\n",
3697 			vc->vc_can_do_color ? "colour" : "mono",
3698 			desc, vc->vc_cols, vc->vc_rows);
3699 
3700 		if (k >= 0) {
3701 			vc = vc_cons[k].d;
3702 			update_screen(vc);
3703 		}
3704 	} else {
3705 		pr_cont("to %s\n", desc);
3706 	}
3707 
3708 	retval = 0;
3709 err:
3710 	module_put(owner);
3711 	return retval;
3712 };
3713 
3714 
3715 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3716 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3717 {
3718 	struct module *owner = csw->owner;
3719 	const struct consw *defcsw = NULL;
3720 	struct con_driver *con_driver = NULL, *con_back = NULL;
3721 	int i, retval = -ENODEV;
3722 
3723 	if (!try_module_get(owner))
3724 		return -ENODEV;
3725 
3726 	WARN_CONSOLE_UNLOCKED();
3727 
3728 	/* check if driver is registered and if it is unbindable */
3729 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3730 		con_driver = &registered_con_driver[i];
3731 
3732 		if (con_driver->con == csw &&
3733 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3734 			retval = 0;
3735 			break;
3736 		}
3737 	}
3738 
3739 	if (retval)
3740 		goto err;
3741 
3742 	retval = -ENODEV;
3743 
3744 	/* check if backup driver exists */
3745 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3746 		con_back = &registered_con_driver[i];
3747 
3748 		if (con_back->con && con_back->con != csw) {
3749 			defcsw = con_back->con;
3750 			retval = 0;
3751 			break;
3752 		}
3753 	}
3754 
3755 	if (retval)
3756 		goto err;
3757 
3758 	if (!con_is_bound(csw))
3759 		goto err;
3760 
3761 	first = max(first, con_driver->first);
3762 	last = min(last, con_driver->last);
3763 
3764 	for (i = first; i <= last; i++) {
3765 		if (con_driver_map[i] == csw) {
3766 			module_put(csw->owner);
3767 			con_driver_map[i] = NULL;
3768 		}
3769 	}
3770 
3771 	if (!con_is_bound(defcsw)) {
3772 		const struct consw *defconsw = conswitchp;
3773 
3774 		defcsw->con_startup();
3775 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3776 		/*
3777 		 * vgacon may change the default driver to point
3778 		 * to dummycon, we restore it here...
3779 		 */
3780 		conswitchp = defconsw;
3781 	}
3782 
3783 	if (!con_is_bound(csw))
3784 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3785 
3786 	/* ignore return value, binding should not fail */
3787 	do_bind_con_driver(defcsw, first, last, deflt);
3788 err:
3789 	module_put(owner);
3790 	return retval;
3791 
3792 }
3793 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3794 
3795 static int vt_bind(struct con_driver *con)
3796 {
3797 	const struct consw *defcsw = NULL, *csw = NULL;
3798 	int i, more = 1, first = -1, last = -1, deflt = 0;
3799 
3800  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3801 		goto err;
3802 
3803 	csw = con->con;
3804 
3805 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3806 		struct con_driver *con = &registered_con_driver[i];
3807 
3808 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3809 			defcsw = con->con;
3810 			break;
3811 		}
3812 	}
3813 
3814 	if (!defcsw)
3815 		goto err;
3816 
3817 	while (more) {
3818 		more = 0;
3819 
3820 		for (i = con->first; i <= con->last; i++) {
3821 			if (con_driver_map[i] == defcsw) {
3822 				if (first == -1)
3823 					first = i;
3824 				last = i;
3825 				more = 1;
3826 			} else if (first != -1)
3827 				break;
3828 		}
3829 
3830 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3831 			deflt = 1;
3832 
3833 		if (first != -1)
3834 			do_bind_con_driver(csw, first, last, deflt);
3835 
3836 		first = -1;
3837 		last = -1;
3838 		deflt = 0;
3839 	}
3840 
3841 err:
3842 	return 0;
3843 }
3844 
3845 static int vt_unbind(struct con_driver *con)
3846 {
3847 	const struct consw *csw = NULL;
3848 	int i, more = 1, first = -1, last = -1, deflt = 0;
3849 	int ret;
3850 
3851  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3852 		goto err;
3853 
3854 	csw = con->con;
3855 
3856 	while (more) {
3857 		more = 0;
3858 
3859 		for (i = con->first; i <= con->last; i++) {
3860 			if (con_driver_map[i] == csw) {
3861 				if (first == -1)
3862 					first = i;
3863 				last = i;
3864 				more = 1;
3865 			} else if (first != -1)
3866 				break;
3867 		}
3868 
3869 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3870 			deflt = 1;
3871 
3872 		if (first != -1) {
3873 			ret = do_unbind_con_driver(csw, first, last, deflt);
3874 			if (ret != 0)
3875 				return ret;
3876 		}
3877 
3878 		first = -1;
3879 		last = -1;
3880 		deflt = 0;
3881 	}
3882 
3883 err:
3884 	return 0;
3885 }
3886 #else
3887 static inline int vt_bind(struct con_driver *con)
3888 {
3889 	return 0;
3890 }
3891 static inline int vt_unbind(struct con_driver *con)
3892 {
3893 	return 0;
3894 }
3895 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3896 
3897 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3898 			  const char *buf, size_t count)
3899 {
3900 	struct con_driver *con = dev_get_drvdata(dev);
3901 	int bind = simple_strtoul(buf, NULL, 0);
3902 
3903 	console_lock();
3904 
3905 	if (bind)
3906 		vt_bind(con);
3907 	else
3908 		vt_unbind(con);
3909 
3910 	console_unlock();
3911 
3912 	return count;
3913 }
3914 
3915 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3916 			 char *buf)
3917 {
3918 	struct con_driver *con = dev_get_drvdata(dev);
3919 	int bind;
3920 
3921 	console_lock();
3922 	bind = con_is_bound(con->con);
3923 	console_unlock();
3924 
3925 	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3926 }
3927 
3928 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3929 			 char *buf)
3930 {
3931 	struct con_driver *con = dev_get_drvdata(dev);
3932 
3933 	return snprintf(buf, PAGE_SIZE, "%s %s\n",
3934 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3935 			 con->desc);
3936 
3937 }
3938 
3939 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3940 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3941 
3942 static struct attribute *con_dev_attrs[] = {
3943 	&dev_attr_bind.attr,
3944 	&dev_attr_name.attr,
3945 	NULL
3946 };
3947 
3948 ATTRIBUTE_GROUPS(con_dev);
3949 
3950 static int vtconsole_init_device(struct con_driver *con)
3951 {
3952 	con->flag |= CON_DRIVER_FLAG_ATTR;
3953 	return 0;
3954 }
3955 
3956 static void vtconsole_deinit_device(struct con_driver *con)
3957 {
3958 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3959 }
3960 
3961 /**
3962  * con_is_bound - checks if driver is bound to the console
3963  * @csw: console driver
3964  *
3965  * RETURNS: zero if unbound, nonzero if bound
3966  *
3967  * Drivers can call this and if zero, they should release
3968  * all resources allocated on con_startup()
3969  */
3970 int con_is_bound(const struct consw *csw)
3971 {
3972 	int i, bound = 0;
3973 
3974 	WARN_CONSOLE_UNLOCKED();
3975 
3976 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3977 		if (con_driver_map[i] == csw) {
3978 			bound = 1;
3979 			break;
3980 		}
3981 	}
3982 
3983 	return bound;
3984 }
3985 EXPORT_SYMBOL(con_is_bound);
3986 
3987 /**
3988  * con_is_visible - checks whether the current console is visible
3989  * @vc: virtual console
3990  *
3991  * RETURNS: zero if not visible, nonzero if visible
3992  */
3993 bool con_is_visible(const struct vc_data *vc)
3994 {
3995 	WARN_CONSOLE_UNLOCKED();
3996 
3997 	return *vc->vc_display_fg == vc;
3998 }
3999 EXPORT_SYMBOL(con_is_visible);
4000 
4001 /**
4002  * con_debug_enter - prepare the console for the kernel debugger
4003  * @vc: virtual console
4004  *
4005  * Called when the console is taken over by the kernel debugger, this
4006  * function needs to save the current console state, then put the console
4007  * into a state suitable for the kernel debugger.
4008  *
4009  * RETURNS:
4010  * Zero on success, nonzero if a failure occurred when trying to prepare
4011  * the console for the debugger.
4012  */
4013 int con_debug_enter(struct vc_data *vc)
4014 {
4015 	int ret = 0;
4016 
4017 	saved_fg_console = fg_console;
4018 	saved_last_console = last_console;
4019 	saved_want_console = want_console;
4020 	saved_vc_mode = vc->vc_mode;
4021 	saved_console_blanked = console_blanked;
4022 	vc->vc_mode = KD_TEXT;
4023 	console_blanked = 0;
4024 	if (vc->vc_sw->con_debug_enter)
4025 		ret = vc->vc_sw->con_debug_enter(vc);
4026 #ifdef CONFIG_KGDB_KDB
4027 	/* Set the initial LINES variable if it is not already set */
4028 	if (vc->vc_rows < 999) {
4029 		int linecount;
4030 		char lns[4];
4031 		const char *setargs[3] = {
4032 			"set",
4033 			"LINES",
4034 			lns,
4035 		};
4036 		if (kdbgetintenv(setargs[0], &linecount)) {
4037 			snprintf(lns, 4, "%i", vc->vc_rows);
4038 			kdb_set(2, setargs);
4039 		}
4040 	}
4041 	if (vc->vc_cols < 999) {
4042 		int colcount;
4043 		char cols[4];
4044 		const char *setargs[3] = {
4045 			"set",
4046 			"COLUMNS",
4047 			cols,
4048 		};
4049 		if (kdbgetintenv(setargs[0], &colcount)) {
4050 			snprintf(cols, 4, "%i", vc->vc_cols);
4051 			kdb_set(2, setargs);
4052 		}
4053 	}
4054 #endif /* CONFIG_KGDB_KDB */
4055 	return ret;
4056 }
4057 EXPORT_SYMBOL_GPL(con_debug_enter);
4058 
4059 /**
4060  * con_debug_leave - restore console state
4061  *
4062  * Restore the console state to what it was before the kernel debugger
4063  * was invoked.
4064  *
4065  * RETURNS:
4066  * Zero on success, nonzero if a failure occurred when trying to restore
4067  * the console.
4068  */
4069 int con_debug_leave(void)
4070 {
4071 	struct vc_data *vc;
4072 	int ret = 0;
4073 
4074 	fg_console = saved_fg_console;
4075 	last_console = saved_last_console;
4076 	want_console = saved_want_console;
4077 	console_blanked = saved_console_blanked;
4078 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
4079 
4080 	vc = vc_cons[fg_console].d;
4081 	if (vc->vc_sw->con_debug_leave)
4082 		ret = vc->vc_sw->con_debug_leave(vc);
4083 	return ret;
4084 }
4085 EXPORT_SYMBOL_GPL(con_debug_leave);
4086 
4087 static int do_register_con_driver(const struct consw *csw, int first, int last)
4088 {
4089 	struct module *owner = csw->owner;
4090 	struct con_driver *con_driver;
4091 	const char *desc;
4092 	int i, retval;
4093 
4094 	WARN_CONSOLE_UNLOCKED();
4095 
4096 	if (!try_module_get(owner))
4097 		return -ENODEV;
4098 
4099 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4100 		con_driver = &registered_con_driver[i];
4101 
4102 		/* already registered */
4103 		if (con_driver->con == csw) {
4104 			retval = -EBUSY;
4105 			goto err;
4106 		}
4107 	}
4108 
4109 	desc = csw->con_startup();
4110 	if (!desc) {
4111 		retval = -ENODEV;
4112 		goto err;
4113 	}
4114 
4115 	retval = -EINVAL;
4116 
4117 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4118 		con_driver = &registered_con_driver[i];
4119 
4120 		if (con_driver->con == NULL &&
4121 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
4122 			con_driver->con = csw;
4123 			con_driver->desc = desc;
4124 			con_driver->node = i;
4125 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
4126 			                   CON_DRIVER_FLAG_INIT;
4127 			con_driver->first = first;
4128 			con_driver->last = last;
4129 			retval = 0;
4130 			break;
4131 		}
4132 	}
4133 
4134 	if (retval)
4135 		goto err;
4136 
4137 	con_driver->dev =
4138 		device_create_with_groups(vtconsole_class, NULL,
4139 					  MKDEV(0, con_driver->node),
4140 					  con_driver, con_dev_groups,
4141 					  "vtcon%i", con_driver->node);
4142 	if (IS_ERR(con_driver->dev)) {
4143 		pr_warn("Unable to create device for %s; errno = %ld\n",
4144 			con_driver->desc, PTR_ERR(con_driver->dev));
4145 		con_driver->dev = NULL;
4146 	} else {
4147 		vtconsole_init_device(con_driver);
4148 	}
4149 
4150 err:
4151 	module_put(owner);
4152 	return retval;
4153 }
4154 
4155 
4156 /**
4157  * do_unregister_con_driver - unregister console driver from console layer
4158  * @csw: console driver
4159  *
4160  * DESCRIPTION: All drivers that registers to the console layer must
4161  * call this function upon exit, or if the console driver is in a state
4162  * where it won't be able to handle console services, such as the
4163  * framebuffer console without loaded framebuffer drivers.
4164  *
4165  * The driver must unbind first prior to unregistration.
4166  */
4167 int do_unregister_con_driver(const struct consw *csw)
4168 {
4169 	int i;
4170 
4171 	/* cannot unregister a bound driver */
4172 	if (con_is_bound(csw))
4173 		return -EBUSY;
4174 
4175 	if (csw == conswitchp)
4176 		return -EINVAL;
4177 
4178 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4179 		struct con_driver *con_driver = &registered_con_driver[i];
4180 
4181 		if (con_driver->con == csw) {
4182 			/*
4183 			 * Defer the removal of the sysfs entries since that
4184 			 * will acquire the kernfs s_active lock and we can't
4185 			 * acquire this lock while holding the console lock:
4186 			 * the unbind sysfs entry imposes already the opposite
4187 			 * order. Reset con already here to prevent any later
4188 			 * lookup to succeed and mark this slot as zombie, so
4189 			 * it won't get reused until we complete the removal
4190 			 * in the deferred work.
4191 			 */
4192 			con_driver->con = NULL;
4193 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4194 			schedule_work(&con_driver_unregister_work);
4195 
4196 			return 0;
4197 		}
4198 	}
4199 
4200 	return -ENODEV;
4201 }
4202 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4203 
4204 static void con_driver_unregister_callback(struct work_struct *ignored)
4205 {
4206 	int i;
4207 
4208 	console_lock();
4209 
4210 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4211 		struct con_driver *con_driver = &registered_con_driver[i];
4212 
4213 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4214 			continue;
4215 
4216 		console_unlock();
4217 
4218 		vtconsole_deinit_device(con_driver);
4219 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4220 
4221 		console_lock();
4222 
4223 		if (WARN_ON_ONCE(con_driver->con))
4224 			con_driver->con = NULL;
4225 		con_driver->desc = NULL;
4226 		con_driver->dev = NULL;
4227 		con_driver->node = 0;
4228 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4229 		con_driver->flag = 0;
4230 		con_driver->first = 0;
4231 		con_driver->last = 0;
4232 	}
4233 
4234 	console_unlock();
4235 }
4236 
4237 /*
4238  *	If we support more console drivers, this function is used
4239  *	when a driver wants to take over some existing consoles
4240  *	and become default driver for newly opened ones.
4241  *
4242  *	do_take_over_console is basically a register followed by bind
4243  */
4244 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4245 {
4246 	int err;
4247 
4248 	err = do_register_con_driver(csw, first, last);
4249 	/*
4250 	 * If we get an busy error we still want to bind the console driver
4251 	 * and return success, as we may have unbound the console driver
4252 	 * but not unregistered it.
4253 	 */
4254 	if (err == -EBUSY)
4255 		err = 0;
4256 	if (!err)
4257 		do_bind_con_driver(csw, first, last, deflt);
4258 
4259 	return err;
4260 }
4261 EXPORT_SYMBOL_GPL(do_take_over_console);
4262 
4263 
4264 /*
4265  * give_up_console is a wrapper to unregister_con_driver. It will only
4266  * work if driver is fully unbound.
4267  */
4268 void give_up_console(const struct consw *csw)
4269 {
4270 	console_lock();
4271 	do_unregister_con_driver(csw);
4272 	console_unlock();
4273 }
4274 
4275 static int __init vtconsole_class_init(void)
4276 {
4277 	int i;
4278 
4279 	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4280 	if (IS_ERR(vtconsole_class)) {
4281 		pr_warn("Unable to create vt console class; errno = %ld\n",
4282 			PTR_ERR(vtconsole_class));
4283 		vtconsole_class = NULL;
4284 	}
4285 
4286 	/* Add system drivers to sysfs */
4287 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4288 		struct con_driver *con = &registered_con_driver[i];
4289 
4290 		if (con->con && !con->dev) {
4291 			con->dev =
4292 				device_create_with_groups(vtconsole_class, NULL,
4293 							  MKDEV(0, con->node),
4294 							  con, con_dev_groups,
4295 							  "vtcon%i", con->node);
4296 
4297 			if (IS_ERR(con->dev)) {
4298 				pr_warn("Unable to create device for %s; errno = %ld\n",
4299 					con->desc, PTR_ERR(con->dev));
4300 				con->dev = NULL;
4301 			} else {
4302 				vtconsole_init_device(con);
4303 			}
4304 		}
4305 	}
4306 
4307 	return 0;
4308 }
4309 postcore_initcall(vtconsole_class_init);
4310 
4311 #endif
4312 
4313 /*
4314  *	Screen blanking
4315  */
4316 
4317 static int set_vesa_blanking(char __user *p)
4318 {
4319 	unsigned int mode;
4320 
4321 	if (get_user(mode, p + 1))
4322 		return -EFAULT;
4323 
4324 	vesa_blank_mode = (mode < 4) ? mode : 0;
4325 	return 0;
4326 }
4327 
4328 void do_blank_screen(int entering_gfx)
4329 {
4330 	struct vc_data *vc = vc_cons[fg_console].d;
4331 	int i;
4332 
4333 	might_sleep();
4334 
4335 	WARN_CONSOLE_UNLOCKED();
4336 
4337 	if (console_blanked) {
4338 		if (blank_state == blank_vesa_wait) {
4339 			blank_state = blank_off;
4340 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4341 		}
4342 		return;
4343 	}
4344 
4345 	/* entering graphics mode? */
4346 	if (entering_gfx) {
4347 		hide_cursor(vc);
4348 		save_screen(vc);
4349 		vc->vc_sw->con_blank(vc, -1, 1);
4350 		console_blanked = fg_console + 1;
4351 		blank_state = blank_off;
4352 		set_origin(vc);
4353 		return;
4354 	}
4355 
4356 	blank_state = blank_off;
4357 
4358 	/* don't blank graphics */
4359 	if (vc->vc_mode != KD_TEXT) {
4360 		console_blanked = fg_console + 1;
4361 		return;
4362 	}
4363 
4364 	hide_cursor(vc);
4365 	del_timer_sync(&console_timer);
4366 	blank_timer_expired = 0;
4367 
4368 	save_screen(vc);
4369 	/* In case we need to reset origin, blanking hook returns 1 */
4370 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4371 	console_blanked = fg_console + 1;
4372 	if (i)
4373 		set_origin(vc);
4374 
4375 	if (console_blank_hook && console_blank_hook(1))
4376 		return;
4377 
4378 	if (vesa_off_interval && vesa_blank_mode) {
4379 		blank_state = blank_vesa_wait;
4380 		mod_timer(&console_timer, jiffies + vesa_off_interval);
4381 	}
4382 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4383 }
4384 EXPORT_SYMBOL(do_blank_screen);
4385 
4386 /*
4387  * Called by timer as well as from vt_console_driver
4388  */
4389 void do_unblank_screen(int leaving_gfx)
4390 {
4391 	struct vc_data *vc;
4392 
4393 	/* This should now always be called from a "sane" (read: can schedule)
4394 	 * context for the sake of the low level drivers, except in the special
4395 	 * case of oops_in_progress
4396 	 */
4397 	if (!oops_in_progress)
4398 		might_sleep();
4399 
4400 	WARN_CONSOLE_UNLOCKED();
4401 
4402 	ignore_poke = 0;
4403 	if (!console_blanked)
4404 		return;
4405 	if (!vc_cons_allocated(fg_console)) {
4406 		/* impossible */
4407 		pr_warn("unblank_screen: tty %d not allocated ??\n",
4408 			fg_console + 1);
4409 		return;
4410 	}
4411 	vc = vc_cons[fg_console].d;
4412 	if (vc->vc_mode != KD_TEXT)
4413 		return; /* but leave console_blanked != 0 */
4414 
4415 	if (blankinterval) {
4416 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4417 		blank_state = blank_normal_wait;
4418 	}
4419 
4420 	console_blanked = 0;
4421 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4422 		/* Low-level driver cannot restore -> do it ourselves */
4423 		update_screen(vc);
4424 	if (console_blank_hook)
4425 		console_blank_hook(0);
4426 	set_palette(vc);
4427 	set_cursor(vc);
4428 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4429 }
4430 EXPORT_SYMBOL(do_unblank_screen);
4431 
4432 /*
4433  * This is called by the outside world to cause a forced unblank, mostly for
4434  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4435  * call it with 1 as an argument and so force a mode restore... that may kill
4436  * X or at least garbage the screen but would also make the Oops visible...
4437  */
4438 void unblank_screen(void)
4439 {
4440 	do_unblank_screen(0);
4441 }
4442 
4443 /*
4444  * We defer the timer blanking to work queue so it can take the console mutex
4445  * (console operations can still happen at irq time, but only from printk which
4446  * has the console mutex. Not perfect yet, but better than no locking
4447  */
4448 static void blank_screen_t(struct timer_list *unused)
4449 {
4450 	blank_timer_expired = 1;
4451 	schedule_work(&console_work);
4452 }
4453 
4454 void poke_blanked_console(void)
4455 {
4456 	WARN_CONSOLE_UNLOCKED();
4457 
4458 	/* Add this so we quickly catch whoever might call us in a non
4459 	 * safe context. Nowadays, unblank_screen() isn't to be called in
4460 	 * atomic contexts and is allowed to schedule (with the special case
4461 	 * of oops_in_progress, but that isn't of any concern for this
4462 	 * function. --BenH.
4463 	 */
4464 	might_sleep();
4465 
4466 	/* This isn't perfectly race free, but a race here would be mostly harmless,
4467 	 * at worst, we'll do a spurious blank and it's unlikely
4468 	 */
4469 	del_timer(&console_timer);
4470 	blank_timer_expired = 0;
4471 
4472 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4473 		return;
4474 	if (console_blanked)
4475 		unblank_screen();
4476 	else if (blankinterval) {
4477 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4478 		blank_state = blank_normal_wait;
4479 	}
4480 }
4481 
4482 /*
4483  *	Palettes
4484  */
4485 
4486 static void set_palette(struct vc_data *vc)
4487 {
4488 	WARN_CONSOLE_UNLOCKED();
4489 
4490 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4491 		vc->vc_sw->con_set_palette(vc, color_table);
4492 }
4493 
4494 /*
4495  * Load palette into the DAC registers. arg points to a colour
4496  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4497  */
4498 
4499 int con_set_cmap(unsigned char __user *arg)
4500 {
4501 	int i, j, k;
4502 	unsigned char colormap[3*16];
4503 
4504 	if (copy_from_user(colormap, arg, sizeof(colormap)))
4505 		return -EFAULT;
4506 
4507 	console_lock();
4508 	for (i = k = 0; i < 16; i++) {
4509 		default_red[i] = colormap[k++];
4510 		default_grn[i] = colormap[k++];
4511 		default_blu[i] = colormap[k++];
4512 	}
4513 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
4514 		if (!vc_cons_allocated(i))
4515 			continue;
4516 		for (j = k = 0; j < 16; j++) {
4517 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4518 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4519 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4520 		}
4521 		set_palette(vc_cons[i].d);
4522 	}
4523 	console_unlock();
4524 
4525 	return 0;
4526 }
4527 
4528 int con_get_cmap(unsigned char __user *arg)
4529 {
4530 	int i, k;
4531 	unsigned char colormap[3*16];
4532 
4533 	console_lock();
4534 	for (i = k = 0; i < 16; i++) {
4535 		colormap[k++] = default_red[i];
4536 		colormap[k++] = default_grn[i];
4537 		colormap[k++] = default_blu[i];
4538 	}
4539 	console_unlock();
4540 
4541 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4542 		return -EFAULT;
4543 
4544 	return 0;
4545 }
4546 
4547 void reset_palette(struct vc_data *vc)
4548 {
4549 	int j, k;
4550 	for (j=k=0; j<16; j++) {
4551 		vc->vc_palette[k++] = default_red[j];
4552 		vc->vc_palette[k++] = default_grn[j];
4553 		vc->vc_palette[k++] = default_blu[j];
4554 	}
4555 	set_palette(vc);
4556 }
4557 
4558 /*
4559  *  Font switching
4560  *
4561  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4562  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4563  *  depending on width) reserved for each character which is kinda wasty, but
4564  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4565  *  is up to the actual low-level console-driver convert data into its favorite
4566  *  format (maybe we should add a `fontoffset' field to the `display'
4567  *  structure so we won't have to convert the fontdata all the time.
4568  *  /Jes
4569  */
4570 
4571 #define max_font_size 65536
4572 
4573 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4574 {
4575 	struct console_font font;
4576 	int rc = -EINVAL;
4577 	int c;
4578 
4579 	if (op->data) {
4580 		font.data = kmalloc(max_font_size, GFP_KERNEL);
4581 		if (!font.data)
4582 			return -ENOMEM;
4583 	} else
4584 		font.data = NULL;
4585 
4586 	console_lock();
4587 	if (vc->vc_mode != KD_TEXT)
4588 		rc = -EINVAL;
4589 	else if (vc->vc_sw->con_font_get)
4590 		rc = vc->vc_sw->con_font_get(vc, &font);
4591 	else
4592 		rc = -ENOSYS;
4593 	console_unlock();
4594 
4595 	if (rc)
4596 		goto out;
4597 
4598 	c = (font.width+7)/8 * 32 * font.charcount;
4599 
4600 	if (op->data && font.charcount > op->charcount)
4601 		rc = -ENOSPC;
4602 	if (font.width > op->width || font.height > op->height)
4603 		rc = -ENOSPC;
4604 	if (rc)
4605 		goto out;
4606 
4607 	op->height = font.height;
4608 	op->width = font.width;
4609 	op->charcount = font.charcount;
4610 
4611 	if (op->data && copy_to_user(op->data, font.data, c))
4612 		rc = -EFAULT;
4613 
4614 out:
4615 	kfree(font.data);
4616 	return rc;
4617 }
4618 
4619 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4620 {
4621 	struct console_font font;
4622 	int rc = -EINVAL;
4623 	int size;
4624 
4625 	if (vc->vc_mode != KD_TEXT)
4626 		return -EINVAL;
4627 	if (!op->data)
4628 		return -EINVAL;
4629 	if (op->charcount > 512)
4630 		return -EINVAL;
4631 	if (op->width <= 0 || op->width > 32 || !op->height || op->height > 32)
4632 		return -EINVAL;
4633 	size = (op->width+7)/8 * 32 * op->charcount;
4634 	if (size > max_font_size)
4635 		return -ENOSPC;
4636 
4637 	font.data = memdup_user(op->data, size);
4638 	if (IS_ERR(font.data))
4639 		return PTR_ERR(font.data);
4640 
4641 	font.charcount = op->charcount;
4642 	font.width = op->width;
4643 	font.height = op->height;
4644 
4645 	console_lock();
4646 	if (vc->vc_mode != KD_TEXT)
4647 		rc = -EINVAL;
4648 	else if (vc->vc_sw->con_font_set)
4649 		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4650 	else
4651 		rc = -ENOSYS;
4652 	console_unlock();
4653 	kfree(font.data);
4654 	return rc;
4655 }
4656 
4657 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4658 {
4659 	struct console_font font = {.width = op->width, .height = op->height};
4660 	char name[MAX_FONT_NAME];
4661 	char *s = name;
4662 	int rc;
4663 
4664 
4665 	if (!op->data)
4666 		s = NULL;
4667 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4668 		return -EFAULT;
4669 	else
4670 		name[MAX_FONT_NAME - 1] = 0;
4671 
4672 	console_lock();
4673 	if (vc->vc_mode != KD_TEXT) {
4674 		console_unlock();
4675 		return -EINVAL;
4676 	}
4677 	if (vc->vc_sw->con_font_default)
4678 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4679 	else
4680 		rc = -ENOSYS;
4681 	console_unlock();
4682 	if (!rc) {
4683 		op->width = font.width;
4684 		op->height = font.height;
4685 	}
4686 	return rc;
4687 }
4688 
4689 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4690 {
4691 	switch (op->op) {
4692 	case KD_FONT_OP_SET:
4693 		return con_font_set(vc, op);
4694 	case KD_FONT_OP_GET:
4695 		return con_font_get(vc, op);
4696 	case KD_FONT_OP_SET_DEFAULT:
4697 		return con_font_default(vc, op);
4698 	case KD_FONT_OP_COPY:
4699 		/* was buggy and never really used */
4700 		return -EINVAL;
4701 	}
4702 	return -ENOSYS;
4703 }
4704 
4705 /*
4706  *	Interface exported to selection and vcs.
4707  */
4708 
4709 /* used by selection */
4710 u16 screen_glyph(const struct vc_data *vc, int offset)
4711 {
4712 	u16 w = scr_readw(screenpos(vc, offset, true));
4713 	u16 c = w & 0xff;
4714 
4715 	if (w & vc->vc_hi_font_mask)
4716 		c |= 0x100;
4717 	return c;
4718 }
4719 EXPORT_SYMBOL_GPL(screen_glyph);
4720 
4721 u32 screen_glyph_unicode(const struct vc_data *vc, int n)
4722 {
4723 	struct uni_screen *uniscr = get_vc_uniscr(vc);
4724 
4725 	if (uniscr)
4726 		return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4727 	return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4728 }
4729 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4730 
4731 /* used by vcs - note the word offset */
4732 unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
4733 {
4734 	return screenpos(vc, 2 * w_offset, viewed);
4735 }
4736 EXPORT_SYMBOL_GPL(screen_pos);
4737 
4738 void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
4739 {
4740 	/* clamp values if they don't fit */
4741 	xy[0] = min(vc->state.x, 0xFFu);
4742 	xy[1] = min(vc->state.y, 0xFFu);
4743 }
4744 
4745 void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
4746 {
4747 	hide_cursor(vc);
4748 	gotoxy(vc, xy[0], xy[1]);
4749 	set_cursor(vc);
4750 }
4751 
4752 u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
4753 {
4754 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4755 		return softcursor_original;
4756 	return scr_readw(org);
4757 }
4758 
4759 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4760 {
4761 	scr_writew(val, org);
4762 	if ((unsigned long)org == vc->vc_pos) {
4763 		softcursor_original = -1;
4764 		add_softcursor(vc);
4765 	}
4766 }
4767 
4768 void vcs_scr_updated(struct vc_data *vc)
4769 {
4770 	notify_update(vc);
4771 }
4772 
4773 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4774 		unsigned int rolled_over, void *base, unsigned int size)
4775 {
4776 	unsigned long ubase = (unsigned long)base;
4777 	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4778 	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4779 	ptrdiff_t origin = (void *)c->vc_origin - base;
4780 	int margin = c->vc_size_row * 4;
4781 	int from, wrap, from_off, avail;
4782 
4783 	/* Turn scrollback off */
4784 	if (!lines) {
4785 		c->vc_visible_origin = c->vc_origin;
4786 		return;
4787 	}
4788 
4789 	/* Do we have already enough to allow jumping from 0 to the end? */
4790 	if (rolled_over > scr_end + margin) {
4791 		from = scr_end;
4792 		wrap = rolled_over + c->vc_size_row;
4793 	} else {
4794 		from = 0;
4795 		wrap = size;
4796 	}
4797 
4798 	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4799 	avail = (origin - from + wrap) % wrap;
4800 
4801 	/* Only a little piece would be left? Show all incl. the piece! */
4802 	if (avail < 2 * margin)
4803 		margin = 0;
4804 	if (from_off < margin)
4805 		from_off = 0;
4806 	if (from_off > avail - margin)
4807 		from_off = avail;
4808 
4809 	c->vc_visible_origin = ubase + (from + from_off) % wrap;
4810 }
4811 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4812 
4813 /*
4814  *	Visible symbols for modules
4815  */
4816 
4817 EXPORT_SYMBOL(color_table);
4818 EXPORT_SYMBOL(default_red);
4819 EXPORT_SYMBOL(default_grn);
4820 EXPORT_SYMBOL(default_blu);
4821 EXPORT_SYMBOL(update_region);
4822 EXPORT_SYMBOL(redraw_screen);
4823 EXPORT_SYMBOL(vc_resize);
4824 EXPORT_SYMBOL(fg_console);
4825 EXPORT_SYMBOL(console_blank_hook);
4826 EXPORT_SYMBOL(console_blanked);
4827 EXPORT_SYMBOL(vc_cons);
4828 EXPORT_SYMBOL(global_cursor_default);
4829 #ifndef VT_SINGLE_DRIVER
4830 EXPORT_SYMBOL(give_up_console);
4831 #endif
4832