xref: /openbmc/linux/drivers/tty/vt/vt.c (revision 4ce94eab)
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_mode != KD_GRAPHICS && 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 		put_pid(vc->vt_pid);
1385 		vc_uniscr_set(vc, NULL);
1386 		kfree(vc->vc_screenbuf);
1387 		vc_cons[currcons].d = NULL;
1388 	}
1389 	return vc;
1390 }
1391 
1392 /*
1393  *	VT102 emulator
1394  */
1395 
1396 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1397 
1398 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1399 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1400 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1401 
1402 #define decarm		VC_REPEAT
1403 #define decckm		VC_CKMODE
1404 #define kbdapplic	VC_APPLIC
1405 #define lnm		VC_CRLF
1406 
1407 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1408 				       8,12,10,14, 9,13,11,15 };
1409 
1410 /* the default colour table, for VGA+ colour systems */
1411 unsigned char default_red[] = {
1412 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1413 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1414 };
1415 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1416 
1417 unsigned char default_grn[] = {
1418 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1419 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1420 };
1421 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1422 
1423 unsigned char default_blu[] = {
1424 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1425 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1426 };
1427 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1428 
1429 /*
1430  * gotoxy() must verify all boundaries, because the arguments
1431  * might also be negative. If the given position is out of
1432  * bounds, the cursor is placed at the nearest margin.
1433  */
1434 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1435 {
1436 	int min_y, max_y;
1437 
1438 	if (new_x < 0)
1439 		vc->state.x = 0;
1440 	else {
1441 		if (new_x >= vc->vc_cols)
1442 			vc->state.x = vc->vc_cols - 1;
1443 		else
1444 			vc->state.x = new_x;
1445 	}
1446 
1447  	if (vc->vc_decom) {
1448 		min_y = vc->vc_top;
1449 		max_y = vc->vc_bottom;
1450 	} else {
1451 		min_y = 0;
1452 		max_y = vc->vc_rows;
1453 	}
1454 	if (new_y < min_y)
1455 		vc->state.y = min_y;
1456 	else if (new_y >= max_y)
1457 		vc->state.y = max_y - 1;
1458 	else
1459 		vc->state.y = new_y;
1460 	vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
1461 		(vc->state.x << 1);
1462 	vc->vc_need_wrap = 0;
1463 }
1464 
1465 /* for absolute user moves, when decom is set */
1466 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1467 {
1468 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1469 }
1470 
1471 void scrollback(struct vc_data *vc)
1472 {
1473 	scrolldelta(-(vc->vc_rows / 2));
1474 }
1475 
1476 void scrollfront(struct vc_data *vc, int lines)
1477 {
1478 	if (!lines)
1479 		lines = vc->vc_rows / 2;
1480 	scrolldelta(lines);
1481 }
1482 
1483 static void lf(struct vc_data *vc)
1484 {
1485     	/* don't scroll if above bottom of scrolling region, or
1486 	 * if below scrolling region
1487 	 */
1488 	if (vc->state.y + 1 == vc->vc_bottom)
1489 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1490 	else if (vc->state.y < vc->vc_rows - 1) {
1491 		vc->state.y++;
1492 		vc->vc_pos += vc->vc_size_row;
1493 	}
1494 	vc->vc_need_wrap = 0;
1495 	notify_write(vc, '\n');
1496 }
1497 
1498 static void ri(struct vc_data *vc)
1499 {
1500     	/* don't scroll if below top of scrolling region, or
1501 	 * if above scrolling region
1502 	 */
1503 	if (vc->state.y == vc->vc_top)
1504 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1505 	else if (vc->state.y > 0) {
1506 		vc->state.y--;
1507 		vc->vc_pos -= vc->vc_size_row;
1508 	}
1509 	vc->vc_need_wrap = 0;
1510 }
1511 
1512 static inline void cr(struct vc_data *vc)
1513 {
1514 	vc->vc_pos -= vc->state.x << 1;
1515 	vc->vc_need_wrap = vc->state.x = 0;
1516 	notify_write(vc, '\r');
1517 }
1518 
1519 static inline void bs(struct vc_data *vc)
1520 {
1521 	if (vc->state.x) {
1522 		vc->vc_pos -= 2;
1523 		vc->state.x--;
1524 		vc->vc_need_wrap = 0;
1525 		notify_write(vc, '\b');
1526 	}
1527 }
1528 
1529 static inline void del(struct vc_data *vc)
1530 {
1531 	/* ignored */
1532 }
1533 
1534 static void csi_J(struct vc_data *vc, int vpar)
1535 {
1536 	unsigned int count;
1537 	unsigned short * start;
1538 
1539 	switch (vpar) {
1540 		case 0:	/* erase from cursor to end of display */
1541 			vc_uniscr_clear_line(vc, vc->state.x,
1542 					     vc->vc_cols - vc->state.x);
1543 			vc_uniscr_clear_lines(vc, vc->state.y + 1,
1544 					      vc->vc_rows - vc->state.y - 1);
1545 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1546 			start = (unsigned short *)vc->vc_pos;
1547 			break;
1548 		case 1:	/* erase from start to cursor */
1549 			vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
1550 			vc_uniscr_clear_lines(vc, 0, vc->state.y);
1551 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1552 			start = (unsigned short *)vc->vc_origin;
1553 			break;
1554 		case 3: /* include scrollback */
1555 			flush_scrollback(vc);
1556 			fallthrough;
1557 		case 2: /* erase whole display */
1558 			vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1559 			count = vc->vc_cols * vc->vc_rows;
1560 			start = (unsigned short *)vc->vc_origin;
1561 			break;
1562 		default:
1563 			return;
1564 	}
1565 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1566 	if (con_should_update(vc))
1567 		do_update_region(vc, (unsigned long) start, count);
1568 	vc->vc_need_wrap = 0;
1569 }
1570 
1571 static void csi_K(struct vc_data *vc, int vpar)
1572 {
1573 	unsigned int count;
1574 	unsigned short *start = (unsigned short *)vc->vc_pos;
1575 	int offset;
1576 
1577 	switch (vpar) {
1578 		case 0:	/* erase from cursor to end of line */
1579 			offset = 0;
1580 			count = vc->vc_cols - vc->state.x;
1581 			break;
1582 		case 1:	/* erase from start of line to cursor */
1583 			offset = -vc->state.x;
1584 			count = vc->state.x + 1;
1585 			break;
1586 		case 2: /* erase whole line */
1587 			offset = -vc->state.x;
1588 			count = vc->vc_cols;
1589 			break;
1590 		default:
1591 			return;
1592 	}
1593 	vc_uniscr_clear_line(vc, vc->state.x + offset, count);
1594 	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1595 	vc->vc_need_wrap = 0;
1596 	if (con_should_update(vc))
1597 		do_update_region(vc, (unsigned long)(start + offset), count);
1598 }
1599 
1600 /* erase the following vpar positions */
1601 static void csi_X(struct vc_data *vc, unsigned int vpar)
1602 {					  /* not vt100? */
1603 	unsigned int count;
1604 
1605 	if (!vpar)
1606 		vpar++;
1607 
1608 	count = min(vpar, vc->vc_cols - vc->state.x);
1609 
1610 	vc_uniscr_clear_line(vc, vc->state.x, count);
1611 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1612 	if (con_should_update(vc))
1613 		vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
1614 	vc->vc_need_wrap = 0;
1615 }
1616 
1617 static void default_attr(struct vc_data *vc)
1618 {
1619 	vc->state.intensity = VCI_NORMAL;
1620 	vc->state.italic = false;
1621 	vc->state.underline = false;
1622 	vc->state.reverse = false;
1623 	vc->state.blink = false;
1624 	vc->state.color = vc->vc_def_color;
1625 }
1626 
1627 struct rgb { u8 r; u8 g; u8 b; };
1628 
1629 static void rgb_from_256(int i, struct rgb *c)
1630 {
1631 	if (i < 8) {            /* Standard colours. */
1632 		c->r = i&1 ? 0xaa : 0x00;
1633 		c->g = i&2 ? 0xaa : 0x00;
1634 		c->b = i&4 ? 0xaa : 0x00;
1635 	} else if (i < 16) {
1636 		c->r = i&1 ? 0xff : 0x55;
1637 		c->g = i&2 ? 0xff : 0x55;
1638 		c->b = i&4 ? 0xff : 0x55;
1639 	} else if (i < 232) {   /* 6x6x6 colour cube. */
1640 		c->r = (i - 16) / 36 * 85 / 2;
1641 		c->g = (i - 16) / 6 % 6 * 85 / 2;
1642 		c->b = (i - 16) % 6 * 85 / 2;
1643 	} else                  /* Grayscale ramp. */
1644 		c->r = c->g = c->b = i * 10 - 2312;
1645 }
1646 
1647 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1648 {
1649 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1650 
1651 	if (c->r > max / 2)
1652 		hue |= 4;
1653 	if (c->g > max / 2)
1654 		hue |= 2;
1655 	if (c->b > max / 2)
1656 		hue |= 1;
1657 
1658 	if (hue == 7 && max <= 0x55) {
1659 		hue = 0;
1660 		vc->state.intensity = VCI_BOLD;
1661 	} else if (max > 0xaa)
1662 		vc->state.intensity = VCI_BOLD;
1663 	else
1664 		vc->state.intensity = VCI_NORMAL;
1665 
1666 	vc->state.color = (vc->state.color & 0xf0) | hue;
1667 }
1668 
1669 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1670 {
1671 	/* For backgrounds, err on the dark side. */
1672 	vc->state.color = (vc->state.color & 0x0f)
1673 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1674 }
1675 
1676 /*
1677  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1678  * and thus need to be detected and ignored by hand. That standard also
1679  * wants : rather than ; as separators but sequences containing : are currently
1680  * completely ignored by the parser.
1681  *
1682  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1683  * supporting them.
1684  */
1685 static int vc_t416_color(struct vc_data *vc, int i,
1686 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1687 {
1688 	struct rgb c;
1689 
1690 	i++;
1691 	if (i > vc->vc_npar)
1692 		return i;
1693 
1694 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1695 		/* 256 colours */
1696 		i++;
1697 		rgb_from_256(vc->vc_par[i], &c);
1698 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1699 		/* 24 bit */
1700 		c.r = vc->vc_par[i + 1];
1701 		c.g = vc->vc_par[i + 2];
1702 		c.b = vc->vc_par[i + 3];
1703 		i += 3;
1704 	} else
1705 		return i;
1706 
1707 	set_color(vc, &c);
1708 
1709 	return i;
1710 }
1711 
1712 /* console_lock is held */
1713 static void csi_m(struct vc_data *vc)
1714 {
1715 	int i;
1716 
1717 	for (i = 0; i <= vc->vc_npar; i++)
1718 		switch (vc->vc_par[i]) {
1719 		case 0:	/* all attributes off */
1720 			default_attr(vc);
1721 			break;
1722 		case 1:
1723 			vc->state.intensity = VCI_BOLD;
1724 			break;
1725 		case 2:
1726 			vc->state.intensity = VCI_HALF_BRIGHT;
1727 			break;
1728 		case 3:
1729 			vc->state.italic = true;
1730 			break;
1731 		case 21:
1732 			/*
1733 			 * No console drivers support double underline, so
1734 			 * convert it to a single underline.
1735 			 */
1736 		case 4:
1737 			vc->state.underline = true;
1738 			break;
1739 		case 5:
1740 			vc->state.blink = true;
1741 			break;
1742 		case 7:
1743 			vc->state.reverse = true;
1744 			break;
1745 		case 10: /* ANSI X3.64-1979 (SCO-ish?)
1746 			  * Select primary font, don't display control chars if
1747 			  * defined, don't set bit 8 on output.
1748 			  */
1749 			vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset], vc);
1750 			vc->vc_disp_ctrl = 0;
1751 			vc->vc_toggle_meta = 0;
1752 			break;
1753 		case 11: /* ANSI X3.64-1979 (SCO-ish?)
1754 			  * Select first alternate font, lets chars < 32 be
1755 			  * displayed as ROM chars.
1756 			  */
1757 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1758 			vc->vc_disp_ctrl = 1;
1759 			vc->vc_toggle_meta = 0;
1760 			break;
1761 		case 12: /* ANSI X3.64-1979 (SCO-ish?)
1762 			  * Select second alternate font, toggle high bit
1763 			  * before displaying as ROM char.
1764 			  */
1765 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1766 			vc->vc_disp_ctrl = 1;
1767 			vc->vc_toggle_meta = 1;
1768 			break;
1769 		case 22:
1770 			vc->state.intensity = VCI_NORMAL;
1771 			break;
1772 		case 23:
1773 			vc->state.italic = false;
1774 			break;
1775 		case 24:
1776 			vc->state.underline = false;
1777 			break;
1778 		case 25:
1779 			vc->state.blink = false;
1780 			break;
1781 		case 27:
1782 			vc->state.reverse = false;
1783 			break;
1784 		case 38:
1785 			i = vc_t416_color(vc, i, rgb_foreground);
1786 			break;
1787 		case 48:
1788 			i = vc_t416_color(vc, i, rgb_background);
1789 			break;
1790 		case 39:
1791 			vc->state.color = (vc->vc_def_color & 0x0f) |
1792 				(vc->state.color & 0xf0);
1793 			break;
1794 		case 49:
1795 			vc->state.color = (vc->vc_def_color & 0xf0) |
1796 				(vc->state.color & 0x0f);
1797 			break;
1798 		default:
1799 			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1800 				if (vc->vc_par[i] < 100)
1801 					vc->state.intensity = VCI_BOLD;
1802 				vc->vc_par[i] -= 60;
1803 			}
1804 			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1805 				vc->state.color = color_table[vc->vc_par[i] - 30]
1806 					| (vc->state.color & 0xf0);
1807 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1808 				vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
1809 					| (vc->state.color & 0x0f);
1810 			break;
1811 		}
1812 	update_attr(vc);
1813 }
1814 
1815 static void respond_string(const char *p, size_t len, struct tty_port *port)
1816 {
1817 	tty_insert_flip_string(port, p, len);
1818 	tty_schedule_flip(port);
1819 }
1820 
1821 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1822 {
1823 	char buf[40];
1824 	int len;
1825 
1826 	len = sprintf(buf, "\033[%d;%dR", vc->state.y +
1827 			(vc->vc_decom ? vc->vc_top + 1 : 1),
1828 			vc->state.x + 1);
1829 	respond_string(buf, len, tty->port);
1830 }
1831 
1832 static inline void status_report(struct tty_struct *tty)
1833 {
1834 	static const char teminal_ok[] = "\033[0n";
1835 
1836 	respond_string(teminal_ok, strlen(teminal_ok), tty->port);
1837 }
1838 
1839 static inline void respond_ID(struct tty_struct *tty)
1840 {
1841 	/* terminal answer to an ESC-Z or csi0c query. */
1842 	static const char vt102_id[] = "\033[?6c";
1843 
1844 	respond_string(vt102_id, strlen(vt102_id), tty->port);
1845 }
1846 
1847 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1848 {
1849 	char buf[8];
1850 	int len;
1851 
1852 	len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
1853 			(char)('!' + mrx), (char)('!' + mry));
1854 	respond_string(buf, len, tty->port);
1855 }
1856 
1857 /* invoked via ioctl(TIOCLINUX) and through set_selection_user */
1858 int mouse_reporting(void)
1859 {
1860 	return vc_cons[fg_console].d->vc_report_mouse;
1861 }
1862 
1863 /* console_lock is held */
1864 static void set_mode(struct vc_data *vc, int on_off)
1865 {
1866 	int i;
1867 
1868 	for (i = 0; i <= vc->vc_npar; i++)
1869 		if (vc->vc_priv == EPdec) {
1870 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1871 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1872 				if (on_off)
1873 					set_kbd(vc, decckm);
1874 				else
1875 					clr_kbd(vc, decckm);
1876 				break;
1877 			case 3:	/* 80/132 mode switch unimplemented */
1878 #if 0
1879 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1880 				/* this alone does not suffice; some user mode
1881 				   utility has to change the hardware regs */
1882 #endif
1883 				break;
1884 			case 5:			/* Inverted screen on/off */
1885 				if (vc->vc_decscnm != on_off) {
1886 					vc->vc_decscnm = on_off;
1887 					invert_screen(vc, 0,
1888 							vc->vc_screenbuf_size,
1889 							false);
1890 					update_attr(vc);
1891 				}
1892 				break;
1893 			case 6:			/* Origin relative/absolute */
1894 				vc->vc_decom = on_off;
1895 				gotoxay(vc, 0, 0);
1896 				break;
1897 			case 7:			/* Autowrap on/off */
1898 				vc->vc_decawm = on_off;
1899 				break;
1900 			case 8:			/* Autorepeat on/off */
1901 				if (on_off)
1902 					set_kbd(vc, decarm);
1903 				else
1904 					clr_kbd(vc, decarm);
1905 				break;
1906 			case 9:
1907 				vc->vc_report_mouse = on_off ? 1 : 0;
1908 				break;
1909 			case 25:		/* Cursor on/off */
1910 				vc->vc_deccm = on_off;
1911 				break;
1912 			case 1000:
1913 				vc->vc_report_mouse = on_off ? 2 : 0;
1914 				break;
1915 			}
1916 		} else {
1917 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1918 			case 3:			/* Monitor (display ctrls) */
1919 				vc->vc_disp_ctrl = on_off;
1920 				break;
1921 			case 4:			/* Insert Mode on/off */
1922 				vc->vc_decim = on_off;
1923 				break;
1924 			case 20:		/* Lf, Enter == CrLf/Lf */
1925 				if (on_off)
1926 					set_kbd(vc, lnm);
1927 				else
1928 					clr_kbd(vc, lnm);
1929 				break;
1930 			}
1931 		}
1932 }
1933 
1934 /* console_lock is held */
1935 static void setterm_command(struct vc_data *vc)
1936 {
1937 	switch (vc->vc_par[0]) {
1938 	case 1:	/* set color for underline mode */
1939 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1940 			vc->vc_ulcolor = color_table[vc->vc_par[1]];
1941 			if (vc->state.underline)
1942 				update_attr(vc);
1943 		}
1944 		break;
1945 	case 2:	/* set color for half intensity mode */
1946 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1947 			vc->vc_halfcolor = color_table[vc->vc_par[1]];
1948 			if (vc->state.intensity == VCI_HALF_BRIGHT)
1949 				update_attr(vc);
1950 		}
1951 		break;
1952 	case 8:	/* store colors as defaults */
1953 		vc->vc_def_color = vc->vc_attr;
1954 		if (vc->vc_hi_font_mask == 0x100)
1955 			vc->vc_def_color >>= 1;
1956 		default_attr(vc);
1957 		update_attr(vc);
1958 		break;
1959 	case 9:	/* set blanking interval */
1960 		blankinterval = min(vc->vc_par[1], 60U) * 60;
1961 		poke_blanked_console();
1962 		break;
1963 	case 10: /* set bell frequency in Hz */
1964 		if (vc->vc_npar >= 1)
1965 			vc->vc_bell_pitch = vc->vc_par[1];
1966 		else
1967 			vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1968 		break;
1969 	case 11: /* set bell duration in msec */
1970 		if (vc->vc_npar >= 1)
1971 			vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1972 				msecs_to_jiffies(vc->vc_par[1]) : 0;
1973 		else
1974 			vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1975 		break;
1976 	case 12: /* bring specified console to the front */
1977 		if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1978 			set_console(vc->vc_par[1] - 1);
1979 		break;
1980 	case 13: /* unblank the screen */
1981 		poke_blanked_console();
1982 		break;
1983 	case 14: /* set vesa powerdown interval */
1984 		vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
1985 		break;
1986 	case 15: /* activate the previous console */
1987 		set_console(last_console);
1988 		break;
1989 	case 16: /* set cursor blink duration in msec */
1990 		if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1991 				vc->vc_par[1] <= USHRT_MAX)
1992 			vc->vc_cur_blink_ms = vc->vc_par[1];
1993 		else
1994 			vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1995 		break;
1996 	}
1997 }
1998 
1999 /* console_lock is held */
2000 static void csi_at(struct vc_data *vc, unsigned int nr)
2001 {
2002 	if (nr > vc->vc_cols - vc->state.x)
2003 		nr = vc->vc_cols - vc->state.x;
2004 	else if (!nr)
2005 		nr = 1;
2006 	insert_char(vc, nr);
2007 }
2008 
2009 /* console_lock is held */
2010 static void csi_L(struct vc_data *vc, unsigned int nr)
2011 {
2012 	if (nr > vc->vc_rows - vc->state.y)
2013 		nr = vc->vc_rows - vc->state.y;
2014 	else if (!nr)
2015 		nr = 1;
2016 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
2017 	vc->vc_need_wrap = 0;
2018 }
2019 
2020 /* console_lock is held */
2021 static void csi_P(struct vc_data *vc, unsigned int nr)
2022 {
2023 	if (nr > vc->vc_cols - vc->state.x)
2024 		nr = vc->vc_cols - vc->state.x;
2025 	else if (!nr)
2026 		nr = 1;
2027 	delete_char(vc, nr);
2028 }
2029 
2030 /* console_lock is held */
2031 static void csi_M(struct vc_data *vc, unsigned int nr)
2032 {
2033 	if (nr > vc->vc_rows - vc->state.y)
2034 		nr = vc->vc_rows - vc->state.y;
2035 	else if (!nr)
2036 		nr=1;
2037 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
2038 	vc->vc_need_wrap = 0;
2039 }
2040 
2041 /* console_lock is held (except via vc_init->reset_terminal */
2042 static void save_cur(struct vc_data *vc)
2043 {
2044 	memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
2045 }
2046 
2047 /* console_lock is held */
2048 static void restore_cur(struct vc_data *vc)
2049 {
2050 	memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
2051 
2052 	gotoxy(vc, vc->state.x, vc->state.y);
2053 	vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
2054 			vc);
2055 	update_attr(vc);
2056 	vc->vc_need_wrap = 0;
2057 }
2058 
2059 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2060 	EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2061 	ESpalette, ESosc };
2062 
2063 /* console_lock is held (except via vc_init()) */
2064 static void reset_terminal(struct vc_data *vc, int do_clear)
2065 {
2066 	unsigned int i;
2067 
2068 	vc->vc_top		= 0;
2069 	vc->vc_bottom		= vc->vc_rows;
2070 	vc->vc_state		= ESnormal;
2071 	vc->vc_priv		= EPecma;
2072 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
2073 	vc->state.Gx_charset[0]	= LAT1_MAP;
2074 	vc->state.Gx_charset[1]	= GRAF_MAP;
2075 	vc->state.charset	= 0;
2076 	vc->vc_need_wrap	= 0;
2077 	vc->vc_report_mouse	= 0;
2078 	vc->vc_utf              = default_utf8;
2079 	vc->vc_utf_count	= 0;
2080 
2081 	vc->vc_disp_ctrl	= 0;
2082 	vc->vc_toggle_meta	= 0;
2083 
2084 	vc->vc_decscnm		= 0;
2085 	vc->vc_decom		= 0;
2086 	vc->vc_decawm		= 1;
2087 	vc->vc_deccm		= global_cursor_default;
2088 	vc->vc_decim		= 0;
2089 
2090 	vt_reset_keyboard(vc->vc_num);
2091 
2092 	vc->vc_cursor_type = cur_default;
2093 	vc->vc_complement_mask = vc->vc_s_complement_mask;
2094 
2095 	default_attr(vc);
2096 	update_attr(vc);
2097 
2098 	bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2099 	for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
2100 		set_bit(i, vc->vc_tab_stop);
2101 
2102 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2103 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2104 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2105 
2106 	gotoxy(vc, 0, 0);
2107 	save_cur(vc);
2108 	if (do_clear)
2109 	    csi_J(vc, 2);
2110 }
2111 
2112 static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
2113 {
2114 	unsigned char *charset = &vc->state.Gx_charset[which];
2115 
2116 	switch (c) {
2117 	case '0':
2118 		*charset = GRAF_MAP;
2119 		break;
2120 	case 'B':
2121 		*charset = LAT1_MAP;
2122 		break;
2123 	case 'U':
2124 		*charset = IBMPC_MAP;
2125 		break;
2126 	case 'K':
2127 		*charset = USER_MAP;
2128 		break;
2129 	}
2130 
2131 	if (vc->state.charset == which)
2132 		vc->vc_translate = set_translate(*charset, vc);
2133 }
2134 
2135 /* console_lock is held */
2136 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2137 {
2138 	/*
2139 	 *  Control characters can be used in the _middle_
2140 	 *  of an escape sequence.
2141 	 */
2142 	if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
2143 		return;
2144 	switch (c) {
2145 	case 0:
2146 		return;
2147 	case 7:
2148 		if (vc->vc_state == ESosc)
2149 			vc->vc_state = ESnormal;
2150 		else if (vc->vc_bell_duration)
2151 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2152 		return;
2153 	case 8:
2154 		bs(vc);
2155 		return;
2156 	case 9:
2157 		vc->vc_pos -= (vc->state.x << 1);
2158 
2159 		vc->state.x = find_next_bit(vc->vc_tab_stop,
2160 				min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2161 				vc->state.x + 1);
2162 		if (vc->state.x >= VC_TABSTOPS_COUNT)
2163 			vc->state.x = vc->vc_cols - 1;
2164 
2165 		vc->vc_pos += (vc->state.x << 1);
2166 		notify_write(vc, '\t');
2167 		return;
2168 	case 10: case 11: case 12:
2169 		lf(vc);
2170 		if (!is_kbd(vc, lnm))
2171 			return;
2172 		fallthrough;
2173 	case 13:
2174 		cr(vc);
2175 		return;
2176 	case 14:
2177 		vc->state.charset = 1;
2178 		vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2179 		vc->vc_disp_ctrl = 1;
2180 		return;
2181 	case 15:
2182 		vc->state.charset = 0;
2183 		vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2184 		vc->vc_disp_ctrl = 0;
2185 		return;
2186 	case 24: case 26:
2187 		vc->vc_state = ESnormal;
2188 		return;
2189 	case 27:
2190 		vc->vc_state = ESesc;
2191 		return;
2192 	case 127:
2193 		del(vc);
2194 		return;
2195 	case 128+27:
2196 		vc->vc_state = ESsquare;
2197 		return;
2198 	}
2199 	switch(vc->vc_state) {
2200 	case ESesc:
2201 		vc->vc_state = ESnormal;
2202 		switch (c) {
2203 		case '[':
2204 			vc->vc_state = ESsquare;
2205 			return;
2206 		case ']':
2207 			vc->vc_state = ESnonstd;
2208 			return;
2209 		case '%':
2210 			vc->vc_state = ESpercent;
2211 			return;
2212 		case 'E':
2213 			cr(vc);
2214 			lf(vc);
2215 			return;
2216 		case 'M':
2217 			ri(vc);
2218 			return;
2219 		case 'D':
2220 			lf(vc);
2221 			return;
2222 		case 'H':
2223 			if (vc->state.x < VC_TABSTOPS_COUNT)
2224 				set_bit(vc->state.x, vc->vc_tab_stop);
2225 			return;
2226 		case 'Z':
2227 			respond_ID(tty);
2228 			return;
2229 		case '7':
2230 			save_cur(vc);
2231 			return;
2232 		case '8':
2233 			restore_cur(vc);
2234 			return;
2235 		case '(':
2236 			vc->vc_state = ESsetG0;
2237 			return;
2238 		case ')':
2239 			vc->vc_state = ESsetG1;
2240 			return;
2241 		case '#':
2242 			vc->vc_state = EShash;
2243 			return;
2244 		case 'c':
2245 			reset_terminal(vc, 1);
2246 			return;
2247 		case '>':  /* Numeric keypad */
2248 			clr_kbd(vc, kbdapplic);
2249 			return;
2250 		case '=':  /* Appl. keypad */
2251 			set_kbd(vc, kbdapplic);
2252 			return;
2253 		}
2254 		return;
2255 	case ESnonstd:
2256 		if (c=='P') {   /* palette escape sequence */
2257 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2258 				vc->vc_par[vc->vc_npar] = 0;
2259 			vc->vc_npar = 0;
2260 			vc->vc_state = ESpalette;
2261 			return;
2262 		} else if (c=='R') {   /* reset palette */
2263 			reset_palette(vc);
2264 			vc->vc_state = ESnormal;
2265 		} else if (c>='0' && c<='9')
2266 			vc->vc_state = ESosc;
2267 		else
2268 			vc->vc_state = ESnormal;
2269 		return;
2270 	case ESpalette:
2271 		if (isxdigit(c)) {
2272 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2273 			if (vc->vc_npar == 7) {
2274 				int i = vc->vc_par[0] * 3, j = 1;
2275 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2276 				vc->vc_palette[i++] += vc->vc_par[j++];
2277 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2278 				vc->vc_palette[i++] += vc->vc_par[j++];
2279 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2280 				vc->vc_palette[i] += vc->vc_par[j];
2281 				set_palette(vc);
2282 				vc->vc_state = ESnormal;
2283 			}
2284 		} else
2285 			vc->vc_state = ESnormal;
2286 		return;
2287 	case ESsquare:
2288 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2289 			vc->vc_par[vc->vc_npar] = 0;
2290 		vc->vc_npar = 0;
2291 		vc->vc_state = ESgetpars;
2292 		if (c == '[') { /* Function key */
2293 			vc->vc_state=ESfunckey;
2294 			return;
2295 		}
2296 		switch (c) {
2297 		case '?':
2298 			vc->vc_priv = EPdec;
2299 			return;
2300 		case '>':
2301 			vc->vc_priv = EPgt;
2302 			return;
2303 		case '=':
2304 			vc->vc_priv = EPeq;
2305 			return;
2306 		case '<':
2307 			vc->vc_priv = EPlt;
2308 			return;
2309 		}
2310 		vc->vc_priv = EPecma;
2311 		fallthrough;
2312 	case ESgetpars:
2313 		if (c == ';' && vc->vc_npar < NPAR - 1) {
2314 			vc->vc_npar++;
2315 			return;
2316 		} else if (c>='0' && c<='9') {
2317 			vc->vc_par[vc->vc_npar] *= 10;
2318 			vc->vc_par[vc->vc_npar] += c - '0';
2319 			return;
2320 		}
2321 		if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2322 			vc->vc_state = EScsiignore;
2323 			return;
2324 		}
2325 		vc->vc_state = ESnormal;
2326 		switch(c) {
2327 		case 'h':
2328 			if (vc->vc_priv <= EPdec)
2329 				set_mode(vc, 1);
2330 			return;
2331 		case 'l':
2332 			if (vc->vc_priv <= EPdec)
2333 				set_mode(vc, 0);
2334 			return;
2335 		case 'c':
2336 			if (vc->vc_priv == EPdec) {
2337 				if (vc->vc_par[0])
2338 					vc->vc_cursor_type =
2339 						CUR_MAKE(vc->vc_par[0],
2340 							 vc->vc_par[1],
2341 							 vc->vc_par[2]);
2342 				else
2343 					vc->vc_cursor_type = cur_default;
2344 				return;
2345 			}
2346 			break;
2347 		case 'm':
2348 			if (vc->vc_priv == EPdec) {
2349 				clear_selection();
2350 				if (vc->vc_par[0])
2351 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2352 				else
2353 					vc->vc_complement_mask = vc->vc_s_complement_mask;
2354 				return;
2355 			}
2356 			break;
2357 		case 'n':
2358 			if (vc->vc_priv == EPecma) {
2359 				if (vc->vc_par[0] == 5)
2360 					status_report(tty);
2361 				else if (vc->vc_par[0] == 6)
2362 					cursor_report(vc, tty);
2363 			}
2364 			return;
2365 		}
2366 		if (vc->vc_priv != EPecma) {
2367 			vc->vc_priv = EPecma;
2368 			return;
2369 		}
2370 		switch(c) {
2371 		case 'G': case '`':
2372 			if (vc->vc_par[0])
2373 				vc->vc_par[0]--;
2374 			gotoxy(vc, vc->vc_par[0], vc->state.y);
2375 			return;
2376 		case 'A':
2377 			if (!vc->vc_par[0])
2378 				vc->vc_par[0]++;
2379 			gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2380 			return;
2381 		case 'B': case 'e':
2382 			if (!vc->vc_par[0])
2383 				vc->vc_par[0]++;
2384 			gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2385 			return;
2386 		case 'C': case 'a':
2387 			if (!vc->vc_par[0])
2388 				vc->vc_par[0]++;
2389 			gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2390 			return;
2391 		case 'D':
2392 			if (!vc->vc_par[0])
2393 				vc->vc_par[0]++;
2394 			gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2395 			return;
2396 		case 'E':
2397 			if (!vc->vc_par[0])
2398 				vc->vc_par[0]++;
2399 			gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2400 			return;
2401 		case 'F':
2402 			if (!vc->vc_par[0])
2403 				vc->vc_par[0]++;
2404 			gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2405 			return;
2406 		case 'd':
2407 			if (vc->vc_par[0])
2408 				vc->vc_par[0]--;
2409 			gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2410 			return;
2411 		case 'H': case 'f':
2412 			if (vc->vc_par[0])
2413 				vc->vc_par[0]--;
2414 			if (vc->vc_par[1])
2415 				vc->vc_par[1]--;
2416 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2417 			return;
2418 		case 'J':
2419 			csi_J(vc, vc->vc_par[0]);
2420 			return;
2421 		case 'K':
2422 			csi_K(vc, vc->vc_par[0]);
2423 			return;
2424 		case 'L':
2425 			csi_L(vc, vc->vc_par[0]);
2426 			return;
2427 		case 'M':
2428 			csi_M(vc, vc->vc_par[0]);
2429 			return;
2430 		case 'P':
2431 			csi_P(vc, vc->vc_par[0]);
2432 			return;
2433 		case 'c':
2434 			if (!vc->vc_par[0])
2435 				respond_ID(tty);
2436 			return;
2437 		case 'g':
2438 			if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2439 				set_bit(vc->state.x, vc->vc_tab_stop);
2440 			else if (vc->vc_par[0] == 3)
2441 				bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2442 			return;
2443 		case 'm':
2444 			csi_m(vc);
2445 			return;
2446 		case 'q': /* DECLL - but only 3 leds */
2447 			/* map 0,1,2,3 to 0,1,2,4 */
2448 			if (vc->vc_par[0] < 4)
2449 				vt_set_led_state(vc->vc_num,
2450 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2451 			return;
2452 		case 'r':
2453 			if (!vc->vc_par[0])
2454 				vc->vc_par[0]++;
2455 			if (!vc->vc_par[1])
2456 				vc->vc_par[1] = vc->vc_rows;
2457 			/* Minimum allowed region is 2 lines */
2458 			if (vc->vc_par[0] < vc->vc_par[1] &&
2459 			    vc->vc_par[1] <= vc->vc_rows) {
2460 				vc->vc_top = vc->vc_par[0] - 1;
2461 				vc->vc_bottom = vc->vc_par[1];
2462 				gotoxay(vc, 0, 0);
2463 			}
2464 			return;
2465 		case 's':
2466 			save_cur(vc);
2467 			return;
2468 		case 'u':
2469 			restore_cur(vc);
2470 			return;
2471 		case 'X':
2472 			csi_X(vc, vc->vc_par[0]);
2473 			return;
2474 		case '@':
2475 			csi_at(vc, vc->vc_par[0]);
2476 			return;
2477 		case ']': /* setterm functions */
2478 			setterm_command(vc);
2479 			return;
2480 		}
2481 		return;
2482 	case EScsiignore:
2483 		if (c >= 20 && c <= 0x3f)
2484 			return;
2485 		vc->vc_state = ESnormal;
2486 		return;
2487 	case ESpercent:
2488 		vc->vc_state = ESnormal;
2489 		switch (c) {
2490 		case '@':  /* defined in ISO 2022 */
2491 			vc->vc_utf = 0;
2492 			return;
2493 		case 'G':  /* prelim official escape code */
2494 		case '8':  /* retained for compatibility */
2495 			vc->vc_utf = 1;
2496 			return;
2497 		}
2498 		return;
2499 	case ESfunckey:
2500 		vc->vc_state = ESnormal;
2501 		return;
2502 	case EShash:
2503 		vc->vc_state = ESnormal;
2504 		if (c == '8') {
2505 			/* DEC screen alignment test. kludge :-) */
2506 			vc->vc_video_erase_char =
2507 				(vc->vc_video_erase_char & 0xff00) | 'E';
2508 			csi_J(vc, 2);
2509 			vc->vc_video_erase_char =
2510 				(vc->vc_video_erase_char & 0xff00) | ' ';
2511 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2512 		}
2513 		return;
2514 	case ESsetG0:
2515 		vc_setGx(vc, 0, c);
2516 		vc->vc_state = ESnormal;
2517 		return;
2518 	case ESsetG1:
2519 		vc_setGx(vc, 1, c);
2520 		vc->vc_state = ESnormal;
2521 		return;
2522 	case ESosc:
2523 		return;
2524 	default:
2525 		vc->vc_state = ESnormal;
2526 	}
2527 }
2528 
2529 /* is_double_width() is based on the wcwidth() implementation by
2530  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2531  * Latest version: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2532  */
2533 struct interval {
2534 	uint32_t first;
2535 	uint32_t last;
2536 };
2537 
2538 static int ucs_cmp(const void *key, const void *elt)
2539 {
2540 	uint32_t ucs = *(uint32_t *)key;
2541 	struct interval e = *(struct interval *) elt;
2542 
2543 	if (ucs > e.last)
2544 		return 1;
2545 	else if (ucs < e.first)
2546 		return -1;
2547 	return 0;
2548 }
2549 
2550 static int is_double_width(uint32_t ucs)
2551 {
2552 	static const struct interval double_width[] = {
2553 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2554 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2555 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2556 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2557 	};
2558 	if (ucs < double_width[0].first ||
2559 	    ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2560 		return 0;
2561 
2562 	return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2563 			sizeof(struct interval), ucs_cmp) != NULL;
2564 }
2565 
2566 struct vc_draw_region {
2567 	unsigned long from, to;
2568 	int x;
2569 };
2570 
2571 static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
2572 {
2573 	if (draw->x < 0)
2574 		return;
2575 
2576 	vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
2577 			(u16 *)draw->to - (u16 *)draw->from, vc->state.y,
2578 			draw->x);
2579 	draw->x = -1;
2580 }
2581 
2582 static inline int vc_translate_ascii(const struct vc_data *vc, int c)
2583 {
2584 	if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
2585 		if (vc->vc_toggle_meta)
2586 			c |= 0x80;
2587 
2588 		return vc->vc_translate[c];
2589 	}
2590 
2591 	return c;
2592 }
2593 
2594 
2595 /**
2596  * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
2597  * @c: the received character, or U+FFFD for invalid sequences.
2598  */
2599 static inline int vc_sanitize_unicode(const int c)
2600 {
2601 	if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2602 		return 0xfffd;
2603 
2604 	return c;
2605 }
2606 
2607 /**
2608  * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
2609  * @vc: virtual console
2610  * @c: character to translate
2611  * @rescan: we return true if we need more (continuation) data
2612  *
2613  * @vc_utf_char is the being-constructed unicode character.
2614  * @vc_utf_count is the number of continuation bytes still expected to arrive.
2615  * @vc_npar is the number of continuation bytes arrived so far.
2616  */
2617 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
2618 {
2619 	static const u32 utf8_length_changes[] = {
2620 		0x0000007f, 0x000007ff, 0x0000ffff,
2621 		0x001fffff, 0x03ffffff, 0x7fffffff
2622 	};
2623 
2624 	/* Continuation byte received */
2625 	if ((c & 0xc0) == 0x80) {
2626 		/* Unexpected continuation byte? */
2627 		if (!vc->vc_utf_count)
2628 			return 0xfffd;
2629 
2630 		vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2631 		vc->vc_npar++;
2632 		if (--vc->vc_utf_count)
2633 			goto need_more_bytes;
2634 
2635 		/* Got a whole character */
2636 		c = vc->vc_utf_char;
2637 		/* Reject overlong sequences */
2638 		if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2639 				c > utf8_length_changes[vc->vc_npar])
2640 			return 0xfffd;
2641 
2642 		return vc_sanitize_unicode(c);
2643 	}
2644 
2645 	/* Single ASCII byte or first byte of a sequence received */
2646 	if (vc->vc_utf_count) {
2647 		/* Continuation byte expected */
2648 		*rescan = true;
2649 		vc->vc_utf_count = 0;
2650 		return 0xfffd;
2651 	}
2652 
2653 	/* Nothing to do if an ASCII byte was received */
2654 	if (c <= 0x7f)
2655 		return c;
2656 
2657 	/* First byte of a multibyte sequence received */
2658 	vc->vc_npar = 0;
2659 	if ((c & 0xe0) == 0xc0) {
2660 		vc->vc_utf_count = 1;
2661 		vc->vc_utf_char = (c & 0x1f);
2662 	} else if ((c & 0xf0) == 0xe0) {
2663 		vc->vc_utf_count = 2;
2664 		vc->vc_utf_char = (c & 0x0f);
2665 	} else if ((c & 0xf8) == 0xf0) {
2666 		vc->vc_utf_count = 3;
2667 		vc->vc_utf_char = (c & 0x07);
2668 	} else if ((c & 0xfc) == 0xf8) {
2669 		vc->vc_utf_count = 4;
2670 		vc->vc_utf_char = (c & 0x03);
2671 	} else if ((c & 0xfe) == 0xfc) {
2672 		vc->vc_utf_count = 5;
2673 		vc->vc_utf_char = (c & 0x01);
2674 	} else {
2675 		/* 254 and 255 are invalid */
2676 		return 0xfffd;
2677 	}
2678 
2679 need_more_bytes:
2680 	return -1;
2681 }
2682 
2683 static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
2684 {
2685 	/* Do no translation at all in control states */
2686 	if (vc->vc_state != ESnormal)
2687 		return *c;
2688 
2689 	if (vc->vc_utf && !vc->vc_disp_ctrl)
2690 		return *c = vc_translate_unicode(vc, *c, rescan);
2691 
2692 	/* no utf or alternate charset mode */
2693 	return vc_translate_ascii(vc, *c);
2694 }
2695 
2696 static inline unsigned char vc_invert_attr(const struct vc_data *vc)
2697 {
2698 	if (!vc->vc_can_do_color)
2699 		return vc->vc_attr ^ 0x08;
2700 
2701 	if (vc->vc_hi_font_mask == 0x100)
2702 		return   (vc->vc_attr & 0x11) |
2703 			((vc->vc_attr & 0xe0) >> 4) |
2704 			((vc->vc_attr & 0x0e) << 4);
2705 
2706 	return   (vc->vc_attr & 0x88) |
2707 		((vc->vc_attr & 0x70) >> 4) |
2708 		((vc->vc_attr & 0x07) << 4);
2709 }
2710 
2711 static bool vc_is_control(struct vc_data *vc, int tc, int c)
2712 {
2713 	/*
2714 	 * A bitmap for codes <32. A bit of 1 indicates that the code
2715 	 * corresponding to that bit number invokes some special action (such
2716 	 * as cursor movement) and should not be displayed as a glyph unless
2717 	 * the disp_ctrl mode is explicitly enabled.
2718 	 */
2719 	static const u32 CTRL_ACTION = 0x0d00ff81;
2720 	/* Cannot be overridden by disp_ctrl */
2721 	static const u32 CTRL_ALWAYS = 0x0800f501;
2722 
2723 	if (vc->vc_state != ESnormal)
2724 		return true;
2725 
2726 	if (!tc)
2727 		return true;
2728 
2729 	/*
2730 	 * If the original code was a control character we only allow a glyph
2731 	 * to be displayed if the code is not normally used (such as for cursor
2732 	 * movement) or if the disp_ctrl mode has been explicitly enabled.
2733 	 * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
2734 	 * displayed as control characters, as the console would be pretty
2735 	 * useless without them; to display an arbitrary font position use the
2736 	 * direct-to-font zone in UTF-8 mode.
2737 	 */
2738 	if (c < 32) {
2739 		if (vc->vc_disp_ctrl)
2740 			return CTRL_ALWAYS & BIT(c);
2741 		else
2742 			return vc->vc_utf || (CTRL_ACTION & BIT(c));
2743 	}
2744 
2745 	if (c == 127 && !vc->vc_disp_ctrl)
2746 		return true;
2747 
2748 	if (c == 128 + 27)
2749 		return true;
2750 
2751 	return false;
2752 }
2753 
2754 static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
2755 		struct vc_draw_region *draw)
2756 {
2757 	int next_c;
2758 	unsigned char vc_attr = vc->vc_attr;
2759 	u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
2760 	u8 width = 1;
2761 	bool inverse = false;
2762 
2763 	if (vc->vc_utf && !vc->vc_disp_ctrl) {
2764 		if (is_double_width(c))
2765 			width = 2;
2766 	}
2767 
2768 	/* Now try to find out how to display it */
2769 	tc = conv_uni_to_pc(vc, tc);
2770 	if (tc & ~charmask) {
2771 		if (tc == -1 || tc == -2)
2772 			return -1; /* nothing to display */
2773 
2774 		/* Glyph not found */
2775 		if ((!vc->vc_utf || vc->vc_disp_ctrl || c < 128) &&
2776 				!(c & ~charmask)) {
2777 			/*
2778 			 * In legacy mode use the glyph we get by a 1:1
2779 			 * mapping.
2780 			 * This would make absolutely no sense with Unicode in
2781 			 * mind, but do this for ASCII characters since a font
2782 			 * may lack Unicode mapping info and we don't want to
2783 			 * end up with having question marks only.
2784 			 */
2785 			tc = c;
2786 		} else {
2787 			/*
2788 			 * Display U+FFFD. If it's not found, display an inverse
2789 			 * question mark.
2790 			 */
2791 			tc = conv_uni_to_pc(vc, 0xfffd);
2792 			if (tc < 0) {
2793 				inverse = true;
2794 				tc = conv_uni_to_pc(vc, '?');
2795 				if (tc < 0)
2796 					tc = '?';
2797 
2798 				vc_attr = vc_invert_attr(vc);
2799 				con_flush(vc, draw);
2800 			}
2801 		}
2802 	}
2803 
2804 	next_c = c;
2805 	while (1) {
2806 		if (vc->vc_need_wrap || vc->vc_decim)
2807 			con_flush(vc, draw);
2808 		if (vc->vc_need_wrap) {
2809 			cr(vc);
2810 			lf(vc);
2811 		}
2812 		if (vc->vc_decim)
2813 			insert_char(vc, 1);
2814 		vc_uniscr_putc(vc, next_c);
2815 
2816 		if (himask)
2817 			tc = ((tc & 0x100) ? himask : 0) |
2818 			      (tc &  0xff);
2819 		tc |= (vc_attr << 8) & ~himask;
2820 
2821 		scr_writew(tc, (u16 *)vc->vc_pos);
2822 
2823 		if (con_should_update(vc) && draw->x < 0) {
2824 			draw->x = vc->state.x;
2825 			draw->from = vc->vc_pos;
2826 		}
2827 		if (vc->state.x == vc->vc_cols - 1) {
2828 			vc->vc_need_wrap = vc->vc_decawm;
2829 			draw->to = vc->vc_pos + 2;
2830 		} else {
2831 			vc->state.x++;
2832 			draw->to = (vc->vc_pos += 2);
2833 		}
2834 
2835 		if (!--width)
2836 			break;
2837 
2838 		/* A space is printed in the second column */
2839 		tc = conv_uni_to_pc(vc, ' ');
2840 		if (tc < 0)
2841 			tc = ' ';
2842 		next_c = ' ';
2843 	}
2844 	notify_write(vc, c);
2845 
2846 	if (inverse)
2847 		con_flush(vc, draw);
2848 
2849 	return 0;
2850 }
2851 
2852 /* acquires console_lock */
2853 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2854 {
2855 	struct vc_draw_region draw = {
2856 		.x = -1,
2857 	};
2858 	int c, tc, n = 0;
2859 	unsigned int currcons;
2860 	struct vc_data *vc;
2861 	struct vt_notifier_param param;
2862 	bool rescan;
2863 
2864 	if (in_interrupt())
2865 		return count;
2866 
2867 	console_lock();
2868 	vc = tty->driver_data;
2869 	if (vc == NULL) {
2870 		pr_err("vt: argh, driver_data is NULL !\n");
2871 		console_unlock();
2872 		return 0;
2873 	}
2874 
2875 	currcons = vc->vc_num;
2876 	if (!vc_cons_allocated(currcons)) {
2877 		/* could this happen? */
2878 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2879 		console_unlock();
2880 		return 0;
2881 	}
2882 
2883 
2884 	/* undraw cursor first */
2885 	if (con_is_fg(vc))
2886 		hide_cursor(vc);
2887 
2888 	param.vc = vc;
2889 
2890 	while (!tty->stopped && count) {
2891 		int orig = *buf;
2892 		buf++;
2893 		n++;
2894 		count--;
2895 rescan_last_byte:
2896 		c = orig;
2897 		rescan = false;
2898 
2899 		tc = vc_translate(vc, &c, &rescan);
2900 		if (tc == -1)
2901 			continue;
2902 
2903 		param.c = tc;
2904 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2905 					&param) == NOTIFY_STOP)
2906 			continue;
2907 
2908 		if (vc_is_control(vc, tc, c)) {
2909 			con_flush(vc, &draw);
2910 			do_con_trol(tty, vc, orig);
2911 			continue;
2912 		}
2913 
2914 		if (vc_con_write_normal(vc, tc, c, &draw) < 0)
2915 			continue;
2916 
2917 		if (rescan)
2918 			goto rescan_last_byte;
2919 	}
2920 	con_flush(vc, &draw);
2921 	vc_uniscr_debug_check(vc);
2922 	console_conditional_schedule();
2923 	notify_update(vc);
2924 	console_unlock();
2925 	return n;
2926 }
2927 
2928 /*
2929  * This is the console switching callback.
2930  *
2931  * Doing console switching in a process context allows
2932  * us to do the switches asynchronously (needed when we want
2933  * to switch due to a keyboard interrupt).  Synchronization
2934  * with other console code and prevention of re-entrancy is
2935  * ensured with console_lock.
2936  */
2937 static void console_callback(struct work_struct *ignored)
2938 {
2939 	console_lock();
2940 
2941 	if (want_console >= 0) {
2942 		if (want_console != fg_console &&
2943 		    vc_cons_allocated(want_console)) {
2944 			hide_cursor(vc_cons[fg_console].d);
2945 			change_console(vc_cons[want_console].d);
2946 			/* we only changed when the console had already
2947 			   been allocated - a new console is not created
2948 			   in an interrupt routine */
2949 		}
2950 		want_console = -1;
2951 	}
2952 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2953 		do_poke_blanked_console = 0;
2954 		poke_blanked_console();
2955 	}
2956 	if (scrollback_delta) {
2957 		struct vc_data *vc = vc_cons[fg_console].d;
2958 		clear_selection();
2959 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2960 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2961 		scrollback_delta = 0;
2962 	}
2963 	if (blank_timer_expired) {
2964 		do_blank_screen(0);
2965 		blank_timer_expired = 0;
2966 	}
2967 	notify_update(vc_cons[fg_console].d);
2968 
2969 	console_unlock();
2970 }
2971 
2972 int set_console(int nr)
2973 {
2974 	struct vc_data *vc = vc_cons[fg_console].d;
2975 
2976 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
2977 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2978 
2979 		/*
2980 		 * Console switch will fail in console_callback() or
2981 		 * change_console() so there is no point scheduling
2982 		 * the callback
2983 		 *
2984 		 * Existing set_console() users don't check the return
2985 		 * value so this shouldn't break anything
2986 		 */
2987 		return -EINVAL;
2988 	}
2989 
2990 	want_console = nr;
2991 	schedule_console_callback();
2992 
2993 	return 0;
2994 }
2995 
2996 struct tty_driver *console_driver;
2997 
2998 #ifdef CONFIG_VT_CONSOLE
2999 
3000 /**
3001  * vt_kmsg_redirect() - Sets/gets the kernel message console
3002  * @new:	The new virtual terminal number or -1 if the console should stay
3003  * 		unchanged
3004  *
3005  * By default, the kernel messages are always printed on the current virtual
3006  * console. However, the user may modify that default with the
3007  * TIOCL_SETKMSGREDIRECT ioctl call.
3008  *
3009  * This function sets the kernel message console to be @new. It returns the old
3010  * virtual console number. The virtual terminal number 0 (both as parameter and
3011  * return value) means no redirection (i.e. always printed on the currently
3012  * active console).
3013  *
3014  * The parameter -1 means that only the current console is returned, but the
3015  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
3016  * case to make the code more understandable.
3017  *
3018  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
3019  * the parameter and always returns 0.
3020  */
3021 int vt_kmsg_redirect(int new)
3022 {
3023 	static int kmsg_con;
3024 
3025 	if (new != -1)
3026 		return xchg(&kmsg_con, new);
3027 	else
3028 		return kmsg_con;
3029 }
3030 
3031 /*
3032  *	Console on virtual terminal
3033  *
3034  * The console must be locked when we get here.
3035  */
3036 
3037 static void vt_console_print(struct console *co, const char *b, unsigned count)
3038 {
3039 	struct vc_data *vc = vc_cons[fg_console].d;
3040 	unsigned char c;
3041 	static DEFINE_SPINLOCK(printing_lock);
3042 	const ushort *start;
3043 	ushort start_x, cnt;
3044 	int kmsg_console;
3045 
3046 	/* console busy or not yet initialized */
3047 	if (!printable)
3048 		return;
3049 	if (!spin_trylock(&printing_lock))
3050 		return;
3051 
3052 	kmsg_console = vt_get_kmsg_redirect();
3053 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
3054 		vc = vc_cons[kmsg_console - 1].d;
3055 
3056 	if (!vc_cons_allocated(fg_console)) {
3057 		/* impossible */
3058 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
3059 		goto quit;
3060 	}
3061 
3062 	if (vc->vc_mode != KD_TEXT)
3063 		goto quit;
3064 
3065 	/* undraw cursor first */
3066 	if (con_is_fg(vc))
3067 		hide_cursor(vc);
3068 
3069 	start = (ushort *)vc->vc_pos;
3070 	start_x = vc->state.x;
3071 	cnt = 0;
3072 	while (count--) {
3073 		c = *b++;
3074 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
3075 			if (cnt && con_is_visible(vc))
3076 				vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3077 			cnt = 0;
3078 			if (c == 8) {		/* backspace */
3079 				bs(vc);
3080 				start = (ushort *)vc->vc_pos;
3081 				start_x = vc->state.x;
3082 				continue;
3083 			}
3084 			if (c != 13)
3085 				lf(vc);
3086 			cr(vc);
3087 			start = (ushort *)vc->vc_pos;
3088 			start_x = vc->state.x;
3089 			if (c == 10 || c == 13)
3090 				continue;
3091 		}
3092 		vc_uniscr_putc(vc, c);
3093 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3094 		notify_write(vc, c);
3095 		cnt++;
3096 		if (vc->state.x == vc->vc_cols - 1) {
3097 			vc->vc_need_wrap = 1;
3098 		} else {
3099 			vc->vc_pos += 2;
3100 			vc->state.x++;
3101 		}
3102 	}
3103 	if (cnt && con_is_visible(vc))
3104 		vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3105 	set_cursor(vc);
3106 	notify_update(vc);
3107 
3108 quit:
3109 	spin_unlock(&printing_lock);
3110 }
3111 
3112 static struct tty_driver *vt_console_device(struct console *c, int *index)
3113 {
3114 	*index = c->index ? c->index-1 : fg_console;
3115 	return console_driver;
3116 }
3117 
3118 static struct console vt_console_driver = {
3119 	.name		= "tty",
3120 	.write		= vt_console_print,
3121 	.device		= vt_console_device,
3122 	.unblank	= unblank_screen,
3123 	.flags		= CON_PRINTBUFFER,
3124 	.index		= -1,
3125 };
3126 #endif
3127 
3128 /*
3129  *	Handling of Linux-specific VC ioctls
3130  */
3131 
3132 /*
3133  * Generally a bit racy with respect to console_lock();.
3134  *
3135  * There are some functions which don't need it.
3136  *
3137  * There are some functions which can sleep for arbitrary periods
3138  * (paste_selection) but we don't need the lock there anyway.
3139  *
3140  * set_selection_user has locking, and definitely needs it
3141  */
3142 
3143 int tioclinux(struct tty_struct *tty, unsigned long arg)
3144 {
3145 	char type, data;
3146 	char __user *p = (char __user *)arg;
3147 	int lines;
3148 	int ret;
3149 
3150 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3151 		return -EPERM;
3152 	if (get_user(type, p))
3153 		return -EFAULT;
3154 	ret = 0;
3155 
3156 	switch (type)
3157 	{
3158 		case TIOCL_SETSEL:
3159 			ret = set_selection_user((struct tiocl_selection
3160 						 __user *)(p+1), tty);
3161 			break;
3162 		case TIOCL_PASTESEL:
3163 			ret = paste_selection(tty);
3164 			break;
3165 		case TIOCL_UNBLANKSCREEN:
3166 			console_lock();
3167 			unblank_screen();
3168 			console_unlock();
3169 			break;
3170 		case TIOCL_SELLOADLUT:
3171 			console_lock();
3172 			ret = sel_loadlut(p);
3173 			console_unlock();
3174 			break;
3175 		case TIOCL_GETSHIFTSTATE:
3176 
3177 	/*
3178 	 * Make it possible to react to Shift+Mousebutton.
3179 	 * Note that 'shift_state' is an undocumented
3180 	 * kernel-internal variable; programs not closely
3181 	 * related to the kernel should not use this.
3182 	 */
3183 			data = vt_get_shift_state();
3184 			ret = put_user(data, p);
3185 			break;
3186 		case TIOCL_GETMOUSEREPORTING:
3187 			console_lock();	/* May be overkill */
3188 			data = mouse_reporting();
3189 			console_unlock();
3190 			ret = put_user(data, p);
3191 			break;
3192 		case TIOCL_SETVESABLANK:
3193 			console_lock();
3194 			ret = set_vesa_blanking(p);
3195 			console_unlock();
3196 			break;
3197 		case TIOCL_GETKMSGREDIRECT:
3198 			data = vt_get_kmsg_redirect();
3199 			ret = put_user(data, p);
3200 			break;
3201 		case TIOCL_SETKMSGREDIRECT:
3202 			if (!capable(CAP_SYS_ADMIN)) {
3203 				ret = -EPERM;
3204 			} else {
3205 				if (get_user(data, p+1))
3206 					ret = -EFAULT;
3207 				else
3208 					vt_kmsg_redirect(data);
3209 			}
3210 			break;
3211 		case TIOCL_GETFGCONSOLE:
3212 			/* No locking needed as this is a transiently
3213 			   correct return anyway if the caller hasn't
3214 			   disabled switching */
3215 			ret = fg_console;
3216 			break;
3217 		case TIOCL_SCROLLCONSOLE:
3218 			if (get_user(lines, (s32 __user *)(p+4))) {
3219 				ret = -EFAULT;
3220 			} else {
3221 				/* Need the console lock here. Note that lots
3222 				   of other calls need fixing before the lock
3223 				   is actually useful ! */
3224 				console_lock();
3225 				scrollfront(vc_cons[fg_console].d, lines);
3226 				console_unlock();
3227 				ret = 0;
3228 			}
3229 			break;
3230 		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
3231 			console_lock();
3232 			ignore_poke = 1;
3233 			do_blank_screen(0);
3234 			console_unlock();
3235 			break;
3236 		case TIOCL_BLANKEDSCREEN:
3237 			ret = console_blanked;
3238 			break;
3239 		default:
3240 			ret = -EINVAL;
3241 			break;
3242 	}
3243 	return ret;
3244 }
3245 
3246 /*
3247  * /dev/ttyN handling
3248  */
3249 
3250 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3251 {
3252 	int	retval;
3253 
3254 	retval = do_con_write(tty, buf, count);
3255 	con_flush_chars(tty);
3256 
3257 	return retval;
3258 }
3259 
3260 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3261 {
3262 	if (in_interrupt())
3263 		return 0;	/* n_r3964 calls put_char() from interrupt context */
3264 	return do_con_write(tty, &ch, 1);
3265 }
3266 
3267 static int con_write_room(struct tty_struct *tty)
3268 {
3269 	if (tty->stopped)
3270 		return 0;
3271 	return 32768;		/* No limit, really; we're not buffering */
3272 }
3273 
3274 static int con_chars_in_buffer(struct tty_struct *tty)
3275 {
3276 	return 0;		/* we're not buffering */
3277 }
3278 
3279 /*
3280  * con_throttle and con_unthrottle are only used for
3281  * paste_selection(), which has to stuff in a large number of
3282  * characters...
3283  */
3284 static void con_throttle(struct tty_struct *tty)
3285 {
3286 }
3287 
3288 static void con_unthrottle(struct tty_struct *tty)
3289 {
3290 	struct vc_data *vc = tty->driver_data;
3291 
3292 	wake_up_interruptible(&vc->paste_wait);
3293 }
3294 
3295 /*
3296  * Turn the Scroll-Lock LED on when the tty is stopped
3297  */
3298 static void con_stop(struct tty_struct *tty)
3299 {
3300 	int console_num;
3301 	if (!tty)
3302 		return;
3303 	console_num = tty->index;
3304 	if (!vc_cons_allocated(console_num))
3305 		return;
3306 	vt_kbd_con_stop(console_num);
3307 }
3308 
3309 /*
3310  * Turn the Scroll-Lock LED off when the console is started
3311  */
3312 static void con_start(struct tty_struct *tty)
3313 {
3314 	int console_num;
3315 	if (!tty)
3316 		return;
3317 	console_num = tty->index;
3318 	if (!vc_cons_allocated(console_num))
3319 		return;
3320 	vt_kbd_con_start(console_num);
3321 }
3322 
3323 static void con_flush_chars(struct tty_struct *tty)
3324 {
3325 	struct vc_data *vc;
3326 
3327 	if (in_interrupt())	/* from flush_to_ldisc */
3328 		return;
3329 
3330 	/* if we race with con_close(), vt may be null */
3331 	console_lock();
3332 	vc = tty->driver_data;
3333 	if (vc)
3334 		set_cursor(vc);
3335 	console_unlock();
3336 }
3337 
3338 /*
3339  * Allocate the console screen memory.
3340  */
3341 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3342 {
3343 	unsigned int currcons = tty->index;
3344 	struct vc_data *vc;
3345 	int ret;
3346 
3347 	console_lock();
3348 	ret = vc_allocate(currcons);
3349 	if (ret)
3350 		goto unlock;
3351 
3352 	vc = vc_cons[currcons].d;
3353 
3354 	/* Still being freed */
3355 	if (vc->port.tty) {
3356 		ret = -ERESTARTSYS;
3357 		goto unlock;
3358 	}
3359 
3360 	ret = tty_port_install(&vc->port, driver, tty);
3361 	if (ret)
3362 		goto unlock;
3363 
3364 	tty->driver_data = vc;
3365 	vc->port.tty = tty;
3366 	tty_port_get(&vc->port);
3367 
3368 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3369 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3370 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3371 	}
3372 	if (vc->vc_utf)
3373 		tty->termios.c_iflag |= IUTF8;
3374 	else
3375 		tty->termios.c_iflag &= ~IUTF8;
3376 unlock:
3377 	console_unlock();
3378 	return ret;
3379 }
3380 
3381 static int con_open(struct tty_struct *tty, struct file *filp)
3382 {
3383 	/* everything done in install */
3384 	return 0;
3385 }
3386 
3387 
3388 static void con_close(struct tty_struct *tty, struct file *filp)
3389 {
3390 	/* Nothing to do - we defer to shutdown */
3391 }
3392 
3393 static void con_shutdown(struct tty_struct *tty)
3394 {
3395 	struct vc_data *vc = tty->driver_data;
3396 	BUG_ON(vc == NULL);
3397 	console_lock();
3398 	vc->port.tty = NULL;
3399 	console_unlock();
3400 }
3401 
3402 static void con_cleanup(struct tty_struct *tty)
3403 {
3404 	struct vc_data *vc = tty->driver_data;
3405 
3406 	tty_port_put(&vc->port);
3407 }
3408 
3409 static int default_color           = 7; /* white */
3410 static int default_italic_color    = 2; // green (ASCII)
3411 static int default_underline_color = 3; // cyan (ASCII)
3412 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3413 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3414 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3415 
3416 static void vc_init(struct vc_data *vc, unsigned int rows,
3417 		    unsigned int cols, int do_clear)
3418 {
3419 	int j, k ;
3420 
3421 	vc->vc_cols = cols;
3422 	vc->vc_rows = rows;
3423 	vc->vc_size_row = cols << 1;
3424 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3425 
3426 	set_origin(vc);
3427 	vc->vc_pos = vc->vc_origin;
3428 	reset_vc(vc);
3429 	for (j=k=0; j<16; j++) {
3430 		vc->vc_palette[k++] = default_red[j] ;
3431 		vc->vc_palette[k++] = default_grn[j] ;
3432 		vc->vc_palette[k++] = default_blu[j] ;
3433 	}
3434 	vc->vc_def_color       = default_color;
3435 	vc->vc_ulcolor         = default_underline_color;
3436 	vc->vc_itcolor         = default_italic_color;
3437 	vc->vc_halfcolor       = 0x08;   /* grey */
3438 	init_waitqueue_head(&vc->paste_wait);
3439 	reset_terminal(vc, do_clear);
3440 }
3441 
3442 /*
3443  * This routine initializes console interrupts, and does nothing
3444  * else. If you want the screen to clear, call tty_write with
3445  * the appropriate escape-sequence.
3446  */
3447 
3448 static int __init con_init(void)
3449 {
3450 	const char *display_desc = NULL;
3451 	struct vc_data *vc;
3452 	unsigned int currcons = 0, i;
3453 
3454 	console_lock();
3455 
3456 	if (!conswitchp)
3457 		conswitchp = &dummy_con;
3458 	display_desc = conswitchp->con_startup();
3459 	if (!display_desc) {
3460 		fg_console = 0;
3461 		console_unlock();
3462 		return 0;
3463 	}
3464 
3465 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3466 		struct con_driver *con_driver = &registered_con_driver[i];
3467 
3468 		if (con_driver->con == NULL) {
3469 			con_driver->con = conswitchp;
3470 			con_driver->desc = display_desc;
3471 			con_driver->flag = CON_DRIVER_FLAG_INIT;
3472 			con_driver->first = 0;
3473 			con_driver->last = MAX_NR_CONSOLES - 1;
3474 			break;
3475 		}
3476 	}
3477 
3478 	for (i = 0; i < MAX_NR_CONSOLES; i++)
3479 		con_driver_map[i] = conswitchp;
3480 
3481 	if (blankinterval) {
3482 		blank_state = blank_normal_wait;
3483 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3484 	}
3485 
3486 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3487 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3488 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3489 		tty_port_init(&vc->port);
3490 		visual_init(vc, currcons, 1);
3491 		/* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3492 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3493 		vc_init(vc, vc->vc_rows, vc->vc_cols,
3494 			currcons || !vc->vc_sw->con_save_screen);
3495 	}
3496 	currcons = fg_console = 0;
3497 	master_display_fg = vc = vc_cons[currcons].d;
3498 	set_origin(vc);
3499 	save_screen(vc);
3500 	gotoxy(vc, vc->state.x, vc->state.y);
3501 	csi_J(vc, 0);
3502 	update_screen(vc);
3503 	pr_info("Console: %s %s %dx%d\n",
3504 		vc->vc_can_do_color ? "colour" : "mono",
3505 		display_desc, vc->vc_cols, vc->vc_rows);
3506 	printable = 1;
3507 
3508 	console_unlock();
3509 
3510 #ifdef CONFIG_VT_CONSOLE
3511 	register_console(&vt_console_driver);
3512 #endif
3513 	return 0;
3514 }
3515 console_initcall(con_init);
3516 
3517 static const struct tty_operations con_ops = {
3518 	.install = con_install,
3519 	.open = con_open,
3520 	.close = con_close,
3521 	.write = con_write,
3522 	.write_room = con_write_room,
3523 	.put_char = con_put_char,
3524 	.flush_chars = con_flush_chars,
3525 	.chars_in_buffer = con_chars_in_buffer,
3526 	.ioctl = vt_ioctl,
3527 #ifdef CONFIG_COMPAT
3528 	.compat_ioctl = vt_compat_ioctl,
3529 #endif
3530 	.stop = con_stop,
3531 	.start = con_start,
3532 	.throttle = con_throttle,
3533 	.unthrottle = con_unthrottle,
3534 	.resize = vt_resize,
3535 	.shutdown = con_shutdown,
3536 	.cleanup = con_cleanup,
3537 };
3538 
3539 static struct cdev vc0_cdev;
3540 
3541 static ssize_t show_tty_active(struct device *dev,
3542 				struct device_attribute *attr, char *buf)
3543 {
3544 	return sprintf(buf, "tty%d\n", fg_console + 1);
3545 }
3546 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3547 
3548 static struct attribute *vt_dev_attrs[] = {
3549 	&dev_attr_active.attr,
3550 	NULL
3551 };
3552 
3553 ATTRIBUTE_GROUPS(vt_dev);
3554 
3555 int __init vty_init(const struct file_operations *console_fops)
3556 {
3557 	cdev_init(&vc0_cdev, console_fops);
3558 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3559 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3560 		panic("Couldn't register /dev/tty0 driver\n");
3561 	tty0dev = device_create_with_groups(tty_class, NULL,
3562 					    MKDEV(TTY_MAJOR, 0), NULL,
3563 					    vt_dev_groups, "tty0");
3564 	if (IS_ERR(tty0dev))
3565 		tty0dev = NULL;
3566 
3567 	vcs_init();
3568 
3569 	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3570 	if (!console_driver)
3571 		panic("Couldn't allocate console driver\n");
3572 
3573 	console_driver->name = "tty";
3574 	console_driver->name_base = 1;
3575 	console_driver->major = TTY_MAJOR;
3576 	console_driver->minor_start = 1;
3577 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3578 	console_driver->init_termios = tty_std_termios;
3579 	if (default_utf8)
3580 		console_driver->init_termios.c_iflag |= IUTF8;
3581 	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3582 	tty_set_operations(console_driver, &con_ops);
3583 	if (tty_register_driver(console_driver))
3584 		panic("Couldn't register console driver\n");
3585 	kbd_init();
3586 	console_map_init();
3587 #ifdef CONFIG_MDA_CONSOLE
3588 	mda_console_init();
3589 #endif
3590 	return 0;
3591 }
3592 
3593 #ifndef VT_SINGLE_DRIVER
3594 
3595 static struct class *vtconsole_class;
3596 
3597 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3598 			   int deflt)
3599 {
3600 	struct module *owner = csw->owner;
3601 	const char *desc = NULL;
3602 	struct con_driver *con_driver;
3603 	int i, j = -1, k = -1, retval = -ENODEV;
3604 
3605 	if (!try_module_get(owner))
3606 		return -ENODEV;
3607 
3608 	WARN_CONSOLE_UNLOCKED();
3609 
3610 	/* check if driver is registered */
3611 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3612 		con_driver = &registered_con_driver[i];
3613 
3614 		if (con_driver->con == csw) {
3615 			desc = con_driver->desc;
3616 			retval = 0;
3617 			break;
3618 		}
3619 	}
3620 
3621 	if (retval)
3622 		goto err;
3623 
3624 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3625 		csw->con_startup();
3626 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3627 	}
3628 
3629 	if (deflt) {
3630 		if (conswitchp)
3631 			module_put(conswitchp->owner);
3632 
3633 		__module_get(owner);
3634 		conswitchp = csw;
3635 	}
3636 
3637 	first = max(first, con_driver->first);
3638 	last = min(last, con_driver->last);
3639 
3640 	for (i = first; i <= last; i++) {
3641 		int old_was_color;
3642 		struct vc_data *vc = vc_cons[i].d;
3643 
3644 		if (con_driver_map[i])
3645 			module_put(con_driver_map[i]->owner);
3646 		__module_get(owner);
3647 		con_driver_map[i] = csw;
3648 
3649 		if (!vc || !vc->vc_sw)
3650 			continue;
3651 
3652 		j = i;
3653 
3654 		if (con_is_visible(vc)) {
3655 			k = i;
3656 			save_screen(vc);
3657 		}
3658 
3659 		old_was_color = vc->vc_can_do_color;
3660 		vc->vc_sw->con_deinit(vc);
3661 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3662 		visual_init(vc, i, 0);
3663 		set_origin(vc);
3664 		update_attr(vc);
3665 
3666 		/* If the console changed between mono <-> color, then
3667 		 * the attributes in the screenbuf will be wrong.  The
3668 		 * following resets all attributes to something sane.
3669 		 */
3670 		if (old_was_color != vc->vc_can_do_color)
3671 			clear_buffer_attributes(vc);
3672 	}
3673 
3674 	pr_info("Console: switching ");
3675 	if (!deflt)
3676 		pr_cont("consoles %d-%d ", first + 1, last + 1);
3677 	if (j >= 0) {
3678 		struct vc_data *vc = vc_cons[j].d;
3679 
3680 		pr_cont("to %s %s %dx%d\n",
3681 			vc->vc_can_do_color ? "colour" : "mono",
3682 			desc, vc->vc_cols, vc->vc_rows);
3683 
3684 		if (k >= 0) {
3685 			vc = vc_cons[k].d;
3686 			update_screen(vc);
3687 		}
3688 	} else {
3689 		pr_cont("to %s\n", desc);
3690 	}
3691 
3692 	retval = 0;
3693 err:
3694 	module_put(owner);
3695 	return retval;
3696 };
3697 
3698 
3699 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3700 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3701 {
3702 	struct module *owner = csw->owner;
3703 	const struct consw *defcsw = NULL;
3704 	struct con_driver *con_driver = NULL, *con_back = NULL;
3705 	int i, retval = -ENODEV;
3706 
3707 	if (!try_module_get(owner))
3708 		return -ENODEV;
3709 
3710 	WARN_CONSOLE_UNLOCKED();
3711 
3712 	/* check if driver is registered and if it is unbindable */
3713 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3714 		con_driver = &registered_con_driver[i];
3715 
3716 		if (con_driver->con == csw &&
3717 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3718 			retval = 0;
3719 			break;
3720 		}
3721 	}
3722 
3723 	if (retval)
3724 		goto err;
3725 
3726 	retval = -ENODEV;
3727 
3728 	/* check if backup driver exists */
3729 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3730 		con_back = &registered_con_driver[i];
3731 
3732 		if (con_back->con && con_back->con != csw) {
3733 			defcsw = con_back->con;
3734 			retval = 0;
3735 			break;
3736 		}
3737 	}
3738 
3739 	if (retval)
3740 		goto err;
3741 
3742 	if (!con_is_bound(csw))
3743 		goto err;
3744 
3745 	first = max(first, con_driver->first);
3746 	last = min(last, con_driver->last);
3747 
3748 	for (i = first; i <= last; i++) {
3749 		if (con_driver_map[i] == csw) {
3750 			module_put(csw->owner);
3751 			con_driver_map[i] = NULL;
3752 		}
3753 	}
3754 
3755 	if (!con_is_bound(defcsw)) {
3756 		const struct consw *defconsw = conswitchp;
3757 
3758 		defcsw->con_startup();
3759 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3760 		/*
3761 		 * vgacon may change the default driver to point
3762 		 * to dummycon, we restore it here...
3763 		 */
3764 		conswitchp = defconsw;
3765 	}
3766 
3767 	if (!con_is_bound(csw))
3768 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3769 
3770 	/* ignore return value, binding should not fail */
3771 	do_bind_con_driver(defcsw, first, last, deflt);
3772 err:
3773 	module_put(owner);
3774 	return retval;
3775 
3776 }
3777 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3778 
3779 static int vt_bind(struct con_driver *con)
3780 {
3781 	const struct consw *defcsw = NULL, *csw = NULL;
3782 	int i, more = 1, first = -1, last = -1, deflt = 0;
3783 
3784  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3785 		goto err;
3786 
3787 	csw = con->con;
3788 
3789 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3790 		struct con_driver *con = &registered_con_driver[i];
3791 
3792 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3793 			defcsw = con->con;
3794 			break;
3795 		}
3796 	}
3797 
3798 	if (!defcsw)
3799 		goto err;
3800 
3801 	while (more) {
3802 		more = 0;
3803 
3804 		for (i = con->first; i <= con->last; i++) {
3805 			if (con_driver_map[i] == defcsw) {
3806 				if (first == -1)
3807 					first = i;
3808 				last = i;
3809 				more = 1;
3810 			} else if (first != -1)
3811 				break;
3812 		}
3813 
3814 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3815 			deflt = 1;
3816 
3817 		if (first != -1)
3818 			do_bind_con_driver(csw, first, last, deflt);
3819 
3820 		first = -1;
3821 		last = -1;
3822 		deflt = 0;
3823 	}
3824 
3825 err:
3826 	return 0;
3827 }
3828 
3829 static int vt_unbind(struct con_driver *con)
3830 {
3831 	const struct consw *csw = NULL;
3832 	int i, more = 1, first = -1, last = -1, deflt = 0;
3833 	int ret;
3834 
3835  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3836 		goto err;
3837 
3838 	csw = con->con;
3839 
3840 	while (more) {
3841 		more = 0;
3842 
3843 		for (i = con->first; i <= con->last; i++) {
3844 			if (con_driver_map[i] == csw) {
3845 				if (first == -1)
3846 					first = i;
3847 				last = i;
3848 				more = 1;
3849 			} else if (first != -1)
3850 				break;
3851 		}
3852 
3853 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3854 			deflt = 1;
3855 
3856 		if (first != -1) {
3857 			ret = do_unbind_con_driver(csw, first, last, deflt);
3858 			if (ret != 0)
3859 				return ret;
3860 		}
3861 
3862 		first = -1;
3863 		last = -1;
3864 		deflt = 0;
3865 	}
3866 
3867 err:
3868 	return 0;
3869 }
3870 #else
3871 static inline int vt_bind(struct con_driver *con)
3872 {
3873 	return 0;
3874 }
3875 static inline int vt_unbind(struct con_driver *con)
3876 {
3877 	return 0;
3878 }
3879 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3880 
3881 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3882 			  const char *buf, size_t count)
3883 {
3884 	struct con_driver *con = dev_get_drvdata(dev);
3885 	int bind = simple_strtoul(buf, NULL, 0);
3886 
3887 	console_lock();
3888 
3889 	if (bind)
3890 		vt_bind(con);
3891 	else
3892 		vt_unbind(con);
3893 
3894 	console_unlock();
3895 
3896 	return count;
3897 }
3898 
3899 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3900 			 char *buf)
3901 {
3902 	struct con_driver *con = dev_get_drvdata(dev);
3903 	int bind;
3904 
3905 	console_lock();
3906 	bind = con_is_bound(con->con);
3907 	console_unlock();
3908 
3909 	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3910 }
3911 
3912 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3913 			 char *buf)
3914 {
3915 	struct con_driver *con = dev_get_drvdata(dev);
3916 
3917 	return snprintf(buf, PAGE_SIZE, "%s %s\n",
3918 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3919 			 con->desc);
3920 
3921 }
3922 
3923 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3924 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3925 
3926 static struct attribute *con_dev_attrs[] = {
3927 	&dev_attr_bind.attr,
3928 	&dev_attr_name.attr,
3929 	NULL
3930 };
3931 
3932 ATTRIBUTE_GROUPS(con_dev);
3933 
3934 static int vtconsole_init_device(struct con_driver *con)
3935 {
3936 	con->flag |= CON_DRIVER_FLAG_ATTR;
3937 	return 0;
3938 }
3939 
3940 static void vtconsole_deinit_device(struct con_driver *con)
3941 {
3942 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3943 }
3944 
3945 /**
3946  * con_is_bound - checks if driver is bound to the console
3947  * @csw: console driver
3948  *
3949  * RETURNS: zero if unbound, nonzero if bound
3950  *
3951  * Drivers can call this and if zero, they should release
3952  * all resources allocated on con_startup()
3953  */
3954 int con_is_bound(const struct consw *csw)
3955 {
3956 	int i, bound = 0;
3957 
3958 	WARN_CONSOLE_UNLOCKED();
3959 
3960 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3961 		if (con_driver_map[i] == csw) {
3962 			bound = 1;
3963 			break;
3964 		}
3965 	}
3966 
3967 	return bound;
3968 }
3969 EXPORT_SYMBOL(con_is_bound);
3970 
3971 /**
3972  * con_is_visible - checks whether the current console is visible
3973  * @vc: virtual console
3974  *
3975  * RETURNS: zero if not visible, nonzero if visible
3976  */
3977 bool con_is_visible(const struct vc_data *vc)
3978 {
3979 	WARN_CONSOLE_UNLOCKED();
3980 
3981 	return *vc->vc_display_fg == vc;
3982 }
3983 EXPORT_SYMBOL(con_is_visible);
3984 
3985 /**
3986  * con_debug_enter - prepare the console for the kernel debugger
3987  * @vc: virtual console
3988  *
3989  * Called when the console is taken over by the kernel debugger, this
3990  * function needs to save the current console state, then put the console
3991  * into a state suitable for the kernel debugger.
3992  *
3993  * RETURNS:
3994  * Zero on success, nonzero if a failure occurred when trying to prepare
3995  * the console for the debugger.
3996  */
3997 int con_debug_enter(struct vc_data *vc)
3998 {
3999 	int ret = 0;
4000 
4001 	saved_fg_console = fg_console;
4002 	saved_last_console = last_console;
4003 	saved_want_console = want_console;
4004 	saved_vc_mode = vc->vc_mode;
4005 	saved_console_blanked = console_blanked;
4006 	vc->vc_mode = KD_TEXT;
4007 	console_blanked = 0;
4008 	if (vc->vc_sw->con_debug_enter)
4009 		ret = vc->vc_sw->con_debug_enter(vc);
4010 #ifdef CONFIG_KGDB_KDB
4011 	/* Set the initial LINES variable if it is not already set */
4012 	if (vc->vc_rows < 999) {
4013 		int linecount;
4014 		char lns[4];
4015 		const char *setargs[3] = {
4016 			"set",
4017 			"LINES",
4018 			lns,
4019 		};
4020 		if (kdbgetintenv(setargs[0], &linecount)) {
4021 			snprintf(lns, 4, "%i", vc->vc_rows);
4022 			kdb_set(2, setargs);
4023 		}
4024 	}
4025 	if (vc->vc_cols < 999) {
4026 		int colcount;
4027 		char cols[4];
4028 		const char *setargs[3] = {
4029 			"set",
4030 			"COLUMNS",
4031 			cols,
4032 		};
4033 		if (kdbgetintenv(setargs[0], &colcount)) {
4034 			snprintf(cols, 4, "%i", vc->vc_cols);
4035 			kdb_set(2, setargs);
4036 		}
4037 	}
4038 #endif /* CONFIG_KGDB_KDB */
4039 	return ret;
4040 }
4041 EXPORT_SYMBOL_GPL(con_debug_enter);
4042 
4043 /**
4044  * con_debug_leave - restore console state
4045  *
4046  * Restore the console state to what it was before the kernel debugger
4047  * was invoked.
4048  *
4049  * RETURNS:
4050  * Zero on success, nonzero if a failure occurred when trying to restore
4051  * the console.
4052  */
4053 int con_debug_leave(void)
4054 {
4055 	struct vc_data *vc;
4056 	int ret = 0;
4057 
4058 	fg_console = saved_fg_console;
4059 	last_console = saved_last_console;
4060 	want_console = saved_want_console;
4061 	console_blanked = saved_console_blanked;
4062 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
4063 
4064 	vc = vc_cons[fg_console].d;
4065 	if (vc->vc_sw->con_debug_leave)
4066 		ret = vc->vc_sw->con_debug_leave(vc);
4067 	return ret;
4068 }
4069 EXPORT_SYMBOL_GPL(con_debug_leave);
4070 
4071 static int do_register_con_driver(const struct consw *csw, int first, int last)
4072 {
4073 	struct module *owner = csw->owner;
4074 	struct con_driver *con_driver;
4075 	const char *desc;
4076 	int i, retval;
4077 
4078 	WARN_CONSOLE_UNLOCKED();
4079 
4080 	if (!try_module_get(owner))
4081 		return -ENODEV;
4082 
4083 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4084 		con_driver = &registered_con_driver[i];
4085 
4086 		/* already registered */
4087 		if (con_driver->con == csw) {
4088 			retval = -EBUSY;
4089 			goto err;
4090 		}
4091 	}
4092 
4093 	desc = csw->con_startup();
4094 	if (!desc) {
4095 		retval = -ENODEV;
4096 		goto err;
4097 	}
4098 
4099 	retval = -EINVAL;
4100 
4101 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4102 		con_driver = &registered_con_driver[i];
4103 
4104 		if (con_driver->con == NULL &&
4105 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
4106 			con_driver->con = csw;
4107 			con_driver->desc = desc;
4108 			con_driver->node = i;
4109 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
4110 			                   CON_DRIVER_FLAG_INIT;
4111 			con_driver->first = first;
4112 			con_driver->last = last;
4113 			retval = 0;
4114 			break;
4115 		}
4116 	}
4117 
4118 	if (retval)
4119 		goto err;
4120 
4121 	con_driver->dev =
4122 		device_create_with_groups(vtconsole_class, NULL,
4123 					  MKDEV(0, con_driver->node),
4124 					  con_driver, con_dev_groups,
4125 					  "vtcon%i", con_driver->node);
4126 	if (IS_ERR(con_driver->dev)) {
4127 		pr_warn("Unable to create device for %s; errno = %ld\n",
4128 			con_driver->desc, PTR_ERR(con_driver->dev));
4129 		con_driver->dev = NULL;
4130 	} else {
4131 		vtconsole_init_device(con_driver);
4132 	}
4133 
4134 err:
4135 	module_put(owner);
4136 	return retval;
4137 }
4138 
4139 
4140 /**
4141  * do_unregister_con_driver - unregister console driver from console layer
4142  * @csw: console driver
4143  *
4144  * DESCRIPTION: All drivers that registers to the console layer must
4145  * call this function upon exit, or if the console driver is in a state
4146  * where it won't be able to handle console services, such as the
4147  * framebuffer console without loaded framebuffer drivers.
4148  *
4149  * The driver must unbind first prior to unregistration.
4150  */
4151 int do_unregister_con_driver(const struct consw *csw)
4152 {
4153 	int i;
4154 
4155 	/* cannot unregister a bound driver */
4156 	if (con_is_bound(csw))
4157 		return -EBUSY;
4158 
4159 	if (csw == conswitchp)
4160 		return -EINVAL;
4161 
4162 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4163 		struct con_driver *con_driver = &registered_con_driver[i];
4164 
4165 		if (con_driver->con == csw) {
4166 			/*
4167 			 * Defer the removal of the sysfs entries since that
4168 			 * will acquire the kernfs s_active lock and we can't
4169 			 * acquire this lock while holding the console lock:
4170 			 * the unbind sysfs entry imposes already the opposite
4171 			 * order. Reset con already here to prevent any later
4172 			 * lookup to succeed and mark this slot as zombie, so
4173 			 * it won't get reused until we complete the removal
4174 			 * in the deferred work.
4175 			 */
4176 			con_driver->con = NULL;
4177 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4178 			schedule_work(&con_driver_unregister_work);
4179 
4180 			return 0;
4181 		}
4182 	}
4183 
4184 	return -ENODEV;
4185 }
4186 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4187 
4188 static void con_driver_unregister_callback(struct work_struct *ignored)
4189 {
4190 	int i;
4191 
4192 	console_lock();
4193 
4194 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4195 		struct con_driver *con_driver = &registered_con_driver[i];
4196 
4197 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4198 			continue;
4199 
4200 		console_unlock();
4201 
4202 		vtconsole_deinit_device(con_driver);
4203 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4204 
4205 		console_lock();
4206 
4207 		if (WARN_ON_ONCE(con_driver->con))
4208 			con_driver->con = NULL;
4209 		con_driver->desc = NULL;
4210 		con_driver->dev = NULL;
4211 		con_driver->node = 0;
4212 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4213 		con_driver->flag = 0;
4214 		con_driver->first = 0;
4215 		con_driver->last = 0;
4216 	}
4217 
4218 	console_unlock();
4219 }
4220 
4221 /*
4222  *	If we support more console drivers, this function is used
4223  *	when a driver wants to take over some existing consoles
4224  *	and become default driver for newly opened ones.
4225  *
4226  *	do_take_over_console is basically a register followed by bind
4227  */
4228 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4229 {
4230 	int err;
4231 
4232 	err = do_register_con_driver(csw, first, last);
4233 	/*
4234 	 * If we get an busy error we still want to bind the console driver
4235 	 * and return success, as we may have unbound the console driver
4236 	 * but not unregistered it.
4237 	 */
4238 	if (err == -EBUSY)
4239 		err = 0;
4240 	if (!err)
4241 		do_bind_con_driver(csw, first, last, deflt);
4242 
4243 	return err;
4244 }
4245 EXPORT_SYMBOL_GPL(do_take_over_console);
4246 
4247 
4248 /*
4249  * give_up_console is a wrapper to unregister_con_driver. It will only
4250  * work if driver is fully unbound.
4251  */
4252 void give_up_console(const struct consw *csw)
4253 {
4254 	console_lock();
4255 	do_unregister_con_driver(csw);
4256 	console_unlock();
4257 }
4258 
4259 static int __init vtconsole_class_init(void)
4260 {
4261 	int i;
4262 
4263 	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4264 	if (IS_ERR(vtconsole_class)) {
4265 		pr_warn("Unable to create vt console class; errno = %ld\n",
4266 			PTR_ERR(vtconsole_class));
4267 		vtconsole_class = NULL;
4268 	}
4269 
4270 	/* Add system drivers to sysfs */
4271 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4272 		struct con_driver *con = &registered_con_driver[i];
4273 
4274 		if (con->con && !con->dev) {
4275 			con->dev =
4276 				device_create_with_groups(vtconsole_class, NULL,
4277 							  MKDEV(0, con->node),
4278 							  con, con_dev_groups,
4279 							  "vtcon%i", con->node);
4280 
4281 			if (IS_ERR(con->dev)) {
4282 				pr_warn("Unable to create device for %s; errno = %ld\n",
4283 					con->desc, PTR_ERR(con->dev));
4284 				con->dev = NULL;
4285 			} else {
4286 				vtconsole_init_device(con);
4287 			}
4288 		}
4289 	}
4290 
4291 	return 0;
4292 }
4293 postcore_initcall(vtconsole_class_init);
4294 
4295 #endif
4296 
4297 /*
4298  *	Screen blanking
4299  */
4300 
4301 static int set_vesa_blanking(char __user *p)
4302 {
4303 	unsigned int mode;
4304 
4305 	if (get_user(mode, p + 1))
4306 		return -EFAULT;
4307 
4308 	vesa_blank_mode = (mode < 4) ? mode : 0;
4309 	return 0;
4310 }
4311 
4312 void do_blank_screen(int entering_gfx)
4313 {
4314 	struct vc_data *vc = vc_cons[fg_console].d;
4315 	int i;
4316 
4317 	might_sleep();
4318 
4319 	WARN_CONSOLE_UNLOCKED();
4320 
4321 	if (console_blanked) {
4322 		if (blank_state == blank_vesa_wait) {
4323 			blank_state = blank_off;
4324 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4325 		}
4326 		return;
4327 	}
4328 
4329 	/* entering graphics mode? */
4330 	if (entering_gfx) {
4331 		hide_cursor(vc);
4332 		save_screen(vc);
4333 		vc->vc_sw->con_blank(vc, -1, 1);
4334 		console_blanked = fg_console + 1;
4335 		blank_state = blank_off;
4336 		set_origin(vc);
4337 		return;
4338 	}
4339 
4340 	blank_state = blank_off;
4341 
4342 	/* don't blank graphics */
4343 	if (vc->vc_mode != KD_TEXT) {
4344 		console_blanked = fg_console + 1;
4345 		return;
4346 	}
4347 
4348 	hide_cursor(vc);
4349 	del_timer_sync(&console_timer);
4350 	blank_timer_expired = 0;
4351 
4352 	save_screen(vc);
4353 	/* In case we need to reset origin, blanking hook returns 1 */
4354 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4355 	console_blanked = fg_console + 1;
4356 	if (i)
4357 		set_origin(vc);
4358 
4359 	if (console_blank_hook && console_blank_hook(1))
4360 		return;
4361 
4362 	if (vesa_off_interval && vesa_blank_mode) {
4363 		blank_state = blank_vesa_wait;
4364 		mod_timer(&console_timer, jiffies + vesa_off_interval);
4365 	}
4366 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4367 }
4368 EXPORT_SYMBOL(do_blank_screen);
4369 
4370 /*
4371  * Called by timer as well as from vt_console_driver
4372  */
4373 void do_unblank_screen(int leaving_gfx)
4374 {
4375 	struct vc_data *vc;
4376 
4377 	/* This should now always be called from a "sane" (read: can schedule)
4378 	 * context for the sake of the low level drivers, except in the special
4379 	 * case of oops_in_progress
4380 	 */
4381 	if (!oops_in_progress)
4382 		might_sleep();
4383 
4384 	WARN_CONSOLE_UNLOCKED();
4385 
4386 	ignore_poke = 0;
4387 	if (!console_blanked)
4388 		return;
4389 	if (!vc_cons_allocated(fg_console)) {
4390 		/* impossible */
4391 		pr_warn("unblank_screen: tty %d not allocated ??\n",
4392 			fg_console + 1);
4393 		return;
4394 	}
4395 	vc = vc_cons[fg_console].d;
4396 	if (vc->vc_mode != KD_TEXT)
4397 		return; /* but leave console_blanked != 0 */
4398 
4399 	if (blankinterval) {
4400 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4401 		blank_state = blank_normal_wait;
4402 	}
4403 
4404 	console_blanked = 0;
4405 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4406 		/* Low-level driver cannot restore -> do it ourselves */
4407 		update_screen(vc);
4408 	if (console_blank_hook)
4409 		console_blank_hook(0);
4410 	set_palette(vc);
4411 	set_cursor(vc);
4412 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4413 }
4414 EXPORT_SYMBOL(do_unblank_screen);
4415 
4416 /*
4417  * This is called by the outside world to cause a forced unblank, mostly for
4418  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4419  * call it with 1 as an argument and so force a mode restore... that may kill
4420  * X or at least garbage the screen but would also make the Oops visible...
4421  */
4422 void unblank_screen(void)
4423 {
4424 	do_unblank_screen(0);
4425 }
4426 
4427 /*
4428  * We defer the timer blanking to work queue so it can take the console mutex
4429  * (console operations can still happen at irq time, but only from printk which
4430  * has the console mutex. Not perfect yet, but better than no locking
4431  */
4432 static void blank_screen_t(struct timer_list *unused)
4433 {
4434 	blank_timer_expired = 1;
4435 	schedule_work(&console_work);
4436 }
4437 
4438 void poke_blanked_console(void)
4439 {
4440 	WARN_CONSOLE_UNLOCKED();
4441 
4442 	/* Add this so we quickly catch whoever might call us in a non
4443 	 * safe context. Nowadays, unblank_screen() isn't to be called in
4444 	 * atomic contexts and is allowed to schedule (with the special case
4445 	 * of oops_in_progress, but that isn't of any concern for this
4446 	 * function. --BenH.
4447 	 */
4448 	might_sleep();
4449 
4450 	/* This isn't perfectly race free, but a race here would be mostly harmless,
4451 	 * at worse, we'll do a spurrious blank and it's unlikely
4452 	 */
4453 	del_timer(&console_timer);
4454 	blank_timer_expired = 0;
4455 
4456 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4457 		return;
4458 	if (console_blanked)
4459 		unblank_screen();
4460 	else if (blankinterval) {
4461 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4462 		blank_state = blank_normal_wait;
4463 	}
4464 }
4465 
4466 /*
4467  *	Palettes
4468  */
4469 
4470 static void set_palette(struct vc_data *vc)
4471 {
4472 	WARN_CONSOLE_UNLOCKED();
4473 
4474 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4475 		vc->vc_sw->con_set_palette(vc, color_table);
4476 }
4477 
4478 /*
4479  * Load palette into the DAC registers. arg points to a colour
4480  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4481  */
4482 
4483 int con_set_cmap(unsigned char __user *arg)
4484 {
4485 	int i, j, k;
4486 	unsigned char colormap[3*16];
4487 
4488 	if (copy_from_user(colormap, arg, sizeof(colormap)))
4489 		return -EFAULT;
4490 
4491 	console_lock();
4492 	for (i = k = 0; i < 16; i++) {
4493 		default_red[i] = colormap[k++];
4494 		default_grn[i] = colormap[k++];
4495 		default_blu[i] = colormap[k++];
4496 	}
4497 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
4498 		if (!vc_cons_allocated(i))
4499 			continue;
4500 		for (j = k = 0; j < 16; j++) {
4501 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4502 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4503 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4504 		}
4505 		set_palette(vc_cons[i].d);
4506 	}
4507 	console_unlock();
4508 
4509 	return 0;
4510 }
4511 
4512 int con_get_cmap(unsigned char __user *arg)
4513 {
4514 	int i, k;
4515 	unsigned char colormap[3*16];
4516 
4517 	console_lock();
4518 	for (i = k = 0; i < 16; i++) {
4519 		colormap[k++] = default_red[i];
4520 		colormap[k++] = default_grn[i];
4521 		colormap[k++] = default_blu[i];
4522 	}
4523 	console_unlock();
4524 
4525 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4526 		return -EFAULT;
4527 
4528 	return 0;
4529 }
4530 
4531 void reset_palette(struct vc_data *vc)
4532 {
4533 	int j, k;
4534 	for (j=k=0; j<16; j++) {
4535 		vc->vc_palette[k++] = default_red[j];
4536 		vc->vc_palette[k++] = default_grn[j];
4537 		vc->vc_palette[k++] = default_blu[j];
4538 	}
4539 	set_palette(vc);
4540 }
4541 
4542 /*
4543  *  Font switching
4544  *
4545  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4546  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4547  *  depending on width) reserved for each character which is kinda wasty, but
4548  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4549  *  is up to the actual low-level console-driver convert data into its favorite
4550  *  format (maybe we should add a `fontoffset' field to the `display'
4551  *  structure so we won't have to convert the fontdata all the time.
4552  *  /Jes
4553  */
4554 
4555 #define max_font_size 65536
4556 
4557 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4558 {
4559 	struct console_font font;
4560 	int rc = -EINVAL;
4561 	int c;
4562 
4563 	if (op->data) {
4564 		font.data = kmalloc(max_font_size, GFP_KERNEL);
4565 		if (!font.data)
4566 			return -ENOMEM;
4567 	} else
4568 		font.data = NULL;
4569 
4570 	console_lock();
4571 	if (vc->vc_mode != KD_TEXT)
4572 		rc = -EINVAL;
4573 	else if (vc->vc_sw->con_font_get)
4574 		rc = vc->vc_sw->con_font_get(vc, &font);
4575 	else
4576 		rc = -ENOSYS;
4577 	console_unlock();
4578 
4579 	if (rc)
4580 		goto out;
4581 
4582 	c = (font.width+7)/8 * 32 * font.charcount;
4583 
4584 	if (op->data && font.charcount > op->charcount)
4585 		rc = -ENOSPC;
4586 	if (font.width > op->width || font.height > op->height)
4587 		rc = -ENOSPC;
4588 	if (rc)
4589 		goto out;
4590 
4591 	op->height = font.height;
4592 	op->width = font.width;
4593 	op->charcount = font.charcount;
4594 
4595 	if (op->data && copy_to_user(op->data, font.data, c))
4596 		rc = -EFAULT;
4597 
4598 out:
4599 	kfree(font.data);
4600 	return rc;
4601 }
4602 
4603 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4604 {
4605 	struct console_font font;
4606 	int rc = -EINVAL;
4607 	int size;
4608 
4609 	if (vc->vc_mode != KD_TEXT)
4610 		return -EINVAL;
4611 	if (!op->data)
4612 		return -EINVAL;
4613 	if (op->charcount > 512)
4614 		return -EINVAL;
4615 	if (op->width <= 0 || op->width > 32 || !op->height || op->height > 32)
4616 		return -EINVAL;
4617 	size = (op->width+7)/8 * 32 * op->charcount;
4618 	if (size > max_font_size)
4619 		return -ENOSPC;
4620 
4621 	font.data = memdup_user(op->data, size);
4622 	if (IS_ERR(font.data))
4623 		return PTR_ERR(font.data);
4624 
4625 	font.charcount = op->charcount;
4626 	font.width = op->width;
4627 	font.height = op->height;
4628 
4629 	console_lock();
4630 	if (vc->vc_mode != KD_TEXT)
4631 		rc = -EINVAL;
4632 	else if (vc->vc_sw->con_font_set)
4633 		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4634 	else
4635 		rc = -ENOSYS;
4636 	console_unlock();
4637 	kfree(font.data);
4638 	return rc;
4639 }
4640 
4641 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4642 {
4643 	struct console_font font = {.width = op->width, .height = op->height};
4644 	char name[MAX_FONT_NAME];
4645 	char *s = name;
4646 	int rc;
4647 
4648 
4649 	if (!op->data)
4650 		s = NULL;
4651 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4652 		return -EFAULT;
4653 	else
4654 		name[MAX_FONT_NAME - 1] = 0;
4655 
4656 	console_lock();
4657 	if (vc->vc_mode != KD_TEXT) {
4658 		console_unlock();
4659 		return -EINVAL;
4660 	}
4661 	if (vc->vc_sw->con_font_default)
4662 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4663 	else
4664 		rc = -ENOSYS;
4665 	console_unlock();
4666 	if (!rc) {
4667 		op->width = font.width;
4668 		op->height = font.height;
4669 	}
4670 	return rc;
4671 }
4672 
4673 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4674 {
4675 	switch (op->op) {
4676 	case KD_FONT_OP_SET:
4677 		return con_font_set(vc, op);
4678 	case KD_FONT_OP_GET:
4679 		return con_font_get(vc, op);
4680 	case KD_FONT_OP_SET_DEFAULT:
4681 		return con_font_default(vc, op);
4682 	case KD_FONT_OP_COPY:
4683 		/* was buggy and never really used */
4684 		return -EINVAL;
4685 	}
4686 	return -ENOSYS;
4687 }
4688 
4689 /*
4690  *	Interface exported to selection and vcs.
4691  */
4692 
4693 /* used by selection */
4694 u16 screen_glyph(const struct vc_data *vc, int offset)
4695 {
4696 	u16 w = scr_readw(screenpos(vc, offset, true));
4697 	u16 c = w & 0xff;
4698 
4699 	if (w & vc->vc_hi_font_mask)
4700 		c |= 0x100;
4701 	return c;
4702 }
4703 EXPORT_SYMBOL_GPL(screen_glyph);
4704 
4705 u32 screen_glyph_unicode(const struct vc_data *vc, int n)
4706 {
4707 	struct uni_screen *uniscr = get_vc_uniscr(vc);
4708 
4709 	if (uniscr)
4710 		return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4711 	return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4712 }
4713 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4714 
4715 /* used by vcs - note the word offset */
4716 unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
4717 {
4718 	return screenpos(vc, 2 * w_offset, viewed);
4719 }
4720 EXPORT_SYMBOL_GPL(screen_pos);
4721 
4722 void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
4723 {
4724 	/* clamp values if they don't fit */
4725 	xy[0] = min(vc->state.x, 0xFFu);
4726 	xy[1] = min(vc->state.y, 0xFFu);
4727 }
4728 
4729 void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
4730 {
4731 	hide_cursor(vc);
4732 	gotoxy(vc, xy[0], xy[1]);
4733 	set_cursor(vc);
4734 }
4735 
4736 u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
4737 {
4738 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4739 		return softcursor_original;
4740 	return scr_readw(org);
4741 }
4742 
4743 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4744 {
4745 	scr_writew(val, org);
4746 	if ((unsigned long)org == vc->vc_pos) {
4747 		softcursor_original = -1;
4748 		add_softcursor(vc);
4749 	}
4750 }
4751 
4752 void vcs_scr_updated(struct vc_data *vc)
4753 {
4754 	notify_update(vc);
4755 }
4756 
4757 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4758 		unsigned int rolled_over, void *base, unsigned int size)
4759 {
4760 	unsigned long ubase = (unsigned long)base;
4761 	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4762 	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4763 	ptrdiff_t origin = (void *)c->vc_origin - base;
4764 	int margin = c->vc_size_row * 4;
4765 	int from, wrap, from_off, avail;
4766 
4767 	/* Turn scrollback off */
4768 	if (!lines) {
4769 		c->vc_visible_origin = c->vc_origin;
4770 		return;
4771 	}
4772 
4773 	/* Do we have already enough to allow jumping from 0 to the end? */
4774 	if (rolled_over > scr_end + margin) {
4775 		from = scr_end;
4776 		wrap = rolled_over + c->vc_size_row;
4777 	} else {
4778 		from = 0;
4779 		wrap = size;
4780 	}
4781 
4782 	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4783 	avail = (origin - from + wrap) % wrap;
4784 
4785 	/* Only a little piece would be left? Show all incl. the piece! */
4786 	if (avail < 2 * margin)
4787 		margin = 0;
4788 	if (from_off < margin)
4789 		from_off = 0;
4790 	if (from_off > avail - margin)
4791 		from_off = avail;
4792 
4793 	c->vc_visible_origin = ubase + (from + from_off) % wrap;
4794 }
4795 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4796 
4797 /*
4798  *	Visible symbols for modules
4799  */
4800 
4801 EXPORT_SYMBOL(color_table);
4802 EXPORT_SYMBOL(default_red);
4803 EXPORT_SYMBOL(default_grn);
4804 EXPORT_SYMBOL(default_blu);
4805 EXPORT_SYMBOL(update_region);
4806 EXPORT_SYMBOL(redraw_screen);
4807 EXPORT_SYMBOL(vc_resize);
4808 EXPORT_SYMBOL(fg_console);
4809 EXPORT_SYMBOL(console_blank_hook);
4810 EXPORT_SYMBOL(console_blanked);
4811 EXPORT_SYMBOL(vc_cons);
4812 EXPORT_SYMBOL(global_cursor_default);
4813 #ifndef VT_SINGLE_DRIVER
4814 EXPORT_SYMBOL(give_up_console);
4815 #endif
4816