xref: /openbmc/linux/drivers/tty/vt/vt.c (revision f0f52af4)
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 EXPORT_SYMBOL(vc_cons);
139 
140 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
141 
142 static int con_open(struct tty_struct *, struct file *);
143 static void vc_init(struct vc_data *vc, int do_clear);
144 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
145 static void save_cur(struct vc_data *vc);
146 static void reset_terminal(struct vc_data *vc, int do_clear);
147 static void con_flush_chars(struct tty_struct *tty);
148 static int set_vesa_blanking(char __user *p);
149 static void set_cursor(struct vc_data *vc);
150 static void hide_cursor(struct vc_data *vc);
151 static void console_callback(struct work_struct *ignored);
152 static void con_driver_unregister_callback(struct work_struct *ignored);
153 static void blank_screen_t(struct timer_list *unused);
154 static void set_palette(struct vc_data *vc);
155 static void unblank_screen(void);
156 
157 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
158 
159 int default_utf8 = true;
160 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
161 int global_cursor_default = -1;
162 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
163 EXPORT_SYMBOL(global_cursor_default);
164 
165 static int cur_default = CUR_UNDERLINE;
166 module_param(cur_default, int, S_IRUGO | S_IWUSR);
167 
168 /*
169  * ignore_poke: don't unblank the screen when things are typed.  This is
170  * mainly for the privacy of braille terminal users.
171  */
172 static int ignore_poke;
173 
174 int do_poke_blanked_console;
175 int console_blanked;
176 EXPORT_SYMBOL(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 EXPORT_SYMBOL(fg_console);
194 int last_console;
195 int want_console = -1;
196 
197 static int saved_fg_console;
198 static int saved_last_console;
199 static int saved_want_console;
200 static int saved_vc_mode;
201 static int saved_console_blanked;
202 
203 /*
204  * For each existing display, we have a pointer to console currently visible
205  * on that display, allowing consoles other than fg_console to be refreshed
206  * appropriately. Unless the low-level driver supplies its own display_fg
207  * variable, we use this one for the "master display".
208  */
209 static struct vc_data *master_display_fg;
210 
211 /*
212  * Unfortunately, we need to delay tty echo when we're currently writing to the
213  * console since the code is (and always was) not re-entrant, so we schedule
214  * all flip requests to process context with schedule-task() and run it from
215  * console_callback().
216  */
217 
218 /*
219  * For the same reason, we defer scrollback to the console callback.
220  */
221 static int scrollback_delta;
222 
223 /*
224  * Hook so that the power management routines can (un)blank
225  * the console on our behalf.
226  */
227 int (*console_blank_hook)(int);
228 EXPORT_SYMBOL(console_blank_hook);
229 
230 static DEFINE_TIMER(console_timer, blank_screen_t);
231 static int blank_state;
232 static int blank_timer_expired;
233 enum {
234 	blank_off = 0,
235 	blank_normal_wait,
236 	blank_vesa_wait,
237 };
238 
239 /*
240  * /sys/class/tty/tty0/
241  *
242  * the attribute 'active' contains the name of the current vc
243  * console and it supports poll() to detect vc switches
244  */
245 static struct device *tty0dev;
246 
247 /*
248  * Notifier list for console events.
249  */
250 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
251 
252 int register_vt_notifier(struct notifier_block *nb)
253 {
254 	return atomic_notifier_chain_register(&vt_notifier_list, nb);
255 }
256 EXPORT_SYMBOL_GPL(register_vt_notifier);
257 
258 int unregister_vt_notifier(struct notifier_block *nb)
259 {
260 	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
261 }
262 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
263 
264 static void notify_write(struct vc_data *vc, unsigned int unicode)
265 {
266 	struct vt_notifier_param param = { .vc = vc, .c = unicode };
267 	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
268 }
269 
270 static void notify_update(struct vc_data *vc)
271 {
272 	struct vt_notifier_param param = { .vc = vc };
273 	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
274 }
275 /*
276  *	Low-Level Functions
277  */
278 
279 static inline bool con_is_fg(const struct vc_data *vc)
280 {
281 	return vc->vc_num == fg_console;
282 }
283 
284 static inline bool con_should_update(const struct vc_data *vc)
285 {
286 	return con_is_visible(vc) && !console_blanked;
287 }
288 
289 static inline unsigned short *screenpos(const struct vc_data *vc, int offset,
290 		bool viewed)
291 {
292 	unsigned short *p;
293 
294 	if (!viewed)
295 		p = (unsigned short *)(vc->vc_origin + offset);
296 	else if (!vc->vc_sw->con_screen_pos)
297 		p = (unsigned short *)(vc->vc_visible_origin + offset);
298 	else
299 		p = vc->vc_sw->con_screen_pos(vc, offset);
300 	return p;
301 }
302 
303 /* Called  from the keyboard irq path.. */
304 static inline void scrolldelta(int lines)
305 {
306 	/* FIXME */
307 	/* scrolldelta needs some kind of consistency lock, but the BKL was
308 	   and still is not protecting versus the scheduled back end */
309 	scrollback_delta += lines;
310 	schedule_console_callback();
311 }
312 
313 void schedule_console_callback(void)
314 {
315 	schedule_work(&console_work);
316 }
317 
318 /*
319  * Code to manage unicode-based screen buffers
320  */
321 
322 /*
323  * Our screen buffer is preceded by an array of line pointers so that
324  * scrolling only implies some pointer shuffling.
325  */
326 
327 static u32 **vc_uniscr_alloc(unsigned int cols, unsigned int rows)
328 {
329 	u32 **uni_lines;
330 	void *p;
331 	unsigned int memsize, i, col_size = cols * sizeof(**uni_lines);
332 
333 	/* allocate everything in one go */
334 	memsize = col_size * rows;
335 	memsize += rows * sizeof(*uni_lines);
336 	uni_lines = vzalloc(memsize);
337 	if (!uni_lines)
338 		return NULL;
339 
340 	/* initial line pointers */
341 	p = uni_lines + rows;
342 	for (i = 0; i < rows; i++) {
343 		uni_lines[i] = p;
344 		p += col_size;
345 	}
346 
347 	return uni_lines;
348 }
349 
350 static void vc_uniscr_free(u32 **uni_lines)
351 {
352 	vfree(uni_lines);
353 }
354 
355 static void vc_uniscr_set(struct vc_data *vc, u32 **new_uni_lines)
356 {
357 	vc_uniscr_free(vc->vc_uni_lines);
358 	vc->vc_uni_lines = new_uni_lines;
359 }
360 
361 static void vc_uniscr_putc(struct vc_data *vc, u32 uc)
362 {
363 	if (vc->vc_uni_lines)
364 		vc->vc_uni_lines[vc->state.y][vc->state.x] = uc;
365 }
366 
367 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
368 {
369 	if (vc->vc_uni_lines) {
370 		u32 *ln = vc->vc_uni_lines[vc->state.y];
371 		unsigned int x = vc->state.x, cols = vc->vc_cols;
372 
373 		memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
374 		memset32(&ln[x], ' ', nr);
375 	}
376 }
377 
378 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
379 {
380 	if (vc->vc_uni_lines) {
381 		u32 *ln = vc->vc_uni_lines[vc->state.y];
382 		unsigned int x = vc->state.x, cols = vc->vc_cols;
383 
384 		memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
385 		memset32(&ln[cols - nr], ' ', nr);
386 	}
387 }
388 
389 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
390 				 unsigned int nr)
391 {
392 	if (vc->vc_uni_lines)
393 		memset32(&vc->vc_uni_lines[vc->state.y][x], ' ', nr);
394 }
395 
396 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
397 				  unsigned int nr)
398 {
399 	if (vc->vc_uni_lines)
400 		while (nr--)
401 			memset32(vc->vc_uni_lines[y++], ' ', vc->vc_cols);
402 }
403 
404 /* juggling array rotation algorithm (complexity O(N), size complexity O(1)) */
405 static void juggle_array(u32 **array, unsigned int size, unsigned int nr)
406 {
407 	unsigned int gcd_idx;
408 
409 	for (gcd_idx = 0; gcd_idx < gcd(nr, size); gcd_idx++) {
410 		u32 *gcd_idx_val = array[gcd_idx];
411 		unsigned int dst_idx = gcd_idx;
412 
413 		while (1) {
414 			unsigned int src_idx = (dst_idx + nr) % size;
415 			if (src_idx == gcd_idx)
416 				break;
417 
418 			array[dst_idx] = array[src_idx];
419 			dst_idx = src_idx;
420 		}
421 
422 		array[dst_idx] = gcd_idx_val;
423 	}
424 }
425 
426 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int top,
427 			     unsigned int bottom, enum con_scroll dir,
428 			     unsigned int nr)
429 {
430 	u32 **uni_lines = vc->vc_uni_lines;
431 	unsigned int size = bottom - top;
432 
433 	if (!uni_lines)
434 		return;
435 
436 	if (dir == SM_DOWN) {
437 		juggle_array(&uni_lines[top], size, size - nr);
438 		vc_uniscr_clear_lines(vc, top, nr);
439 	} else {
440 		juggle_array(&uni_lines[top], size, nr);
441 		vc_uniscr_clear_lines(vc, bottom - nr, nr);
442 	}
443 }
444 
445 static void vc_uniscr_copy_area(u32 **dst_lines,
446 				unsigned int dst_cols,
447 				unsigned int dst_rows,
448 				u32 **src_lines,
449 				unsigned int src_cols,
450 				unsigned int src_top_row,
451 				unsigned int src_bot_row)
452 {
453 	unsigned int dst_row = 0;
454 
455 	if (!dst_lines)
456 		return;
457 
458 	while (src_top_row < src_bot_row) {
459 		u32 *src_line = src_lines[src_top_row];
460 		u32 *dst_line = dst_lines[dst_row];
461 
462 		memcpy(dst_line, src_line, src_cols * sizeof(*src_line));
463 		if (dst_cols - src_cols)
464 			memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
465 		src_top_row++;
466 		dst_row++;
467 	}
468 	while (dst_row < dst_rows) {
469 		u32 *dst_line = dst_lines[dst_row];
470 
471 		memset32(dst_line, ' ', dst_cols);
472 		dst_row++;
473 	}
474 }
475 
476 /*
477  * Called from vcs_read() to make sure unicode screen retrieval is possible.
478  * This will initialize the unicode screen buffer if not already done.
479  * This returns 0 if OK, or a negative error code otherwise.
480  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
481  */
482 int vc_uniscr_check(struct vc_data *vc)
483 {
484 	u32 **uni_lines;
485 	unsigned short *p;
486 	int x, y, mask;
487 
488 	WARN_CONSOLE_UNLOCKED();
489 
490 	if (!vc->vc_utf)
491 		return -ENODATA;
492 
493 	if (vc->vc_uni_lines)
494 		return 0;
495 
496 	uni_lines = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
497 	if (!uni_lines)
498 		return -ENOMEM;
499 
500 	/*
501 	 * Let's populate it initially with (imperfect) reverse translation.
502 	 * This is the next best thing we can do short of having it enabled
503 	 * from the start even when no users rely on this functionality. True
504 	 * unicode content will be available after a complete screen refresh.
505 	 */
506 	p = (unsigned short *)vc->vc_origin;
507 	mask = vc->vc_hi_font_mask | 0xff;
508 	for (y = 0; y < vc->vc_rows; y++) {
509 		u32 *line = uni_lines[y];
510 		for (x = 0; x < vc->vc_cols; x++) {
511 			u16 glyph = scr_readw(p++) & mask;
512 			line[x] = inverse_translate(vc, glyph, true);
513 		}
514 	}
515 
516 	vc->vc_uni_lines = uni_lines;
517 
518 	return 0;
519 }
520 
521 /*
522  * Called from vcs_read() to get the unicode data from the screen.
523  * This must be preceded by a successful call to vc_uniscr_check() once
524  * the console lock has been taken.
525  */
526 void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed,
527 			 unsigned int row, unsigned int col, unsigned int nr)
528 {
529 	u32 **uni_lines = vc->vc_uni_lines;
530 	int offset = row * vc->vc_size_row + col * 2;
531 	unsigned long pos;
532 
533 	if (WARN_ON_ONCE(!uni_lines))
534 		return;
535 
536 	pos = (unsigned long)screenpos(vc, offset, viewed);
537 	if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
538 		/*
539 		 * Desired position falls in the main screen buffer.
540 		 * However the actual row/col might be different if
541 		 * scrollback is active.
542 		 */
543 		row = (pos - vc->vc_origin) / vc->vc_size_row;
544 		col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
545 		memcpy(dest, &uni_lines[row][col], nr * sizeof(u32));
546 	} else {
547 		/*
548 		 * Scrollback is active. For now let's simply backtranslate
549 		 * the screen glyphs until the unicode screen buffer does
550 		 * synchronize with console display drivers for a scrollback
551 		 * buffer of its own.
552 		 */
553 		u16 *p = (u16 *)pos;
554 		int mask = vc->vc_hi_font_mask | 0xff;
555 		u32 *uni_buf = dest;
556 		while (nr--) {
557 			u16 glyph = scr_readw(p++) & mask;
558 			*uni_buf++ = inverse_translate(vc, glyph, true);
559 		}
560 	}
561 }
562 
563 static void con_scroll(struct vc_data *vc, unsigned int top,
564 		       unsigned int bottom, enum con_scroll dir,
565 		       unsigned int nr)
566 {
567 	unsigned int rows = bottom - top;
568 	u16 *clear, *dst, *src;
569 
570 	if (top + nr >= bottom)
571 		nr = rows - 1;
572 	if (bottom > vc->vc_rows || top >= bottom || nr < 1)
573 		return;
574 
575 	vc_uniscr_scroll(vc, top, bottom, dir, nr);
576 	if (con_is_visible(vc) &&
577 			vc->vc_sw->con_scroll(vc, top, bottom, dir, nr))
578 		return;
579 
580 	src = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * top);
581 	dst = (u16 *)(vc->vc_origin + vc->vc_size_row * (top + nr));
582 
583 	if (dir == SM_UP) {
584 		clear = src + (rows - nr) * vc->vc_cols;
585 		swap(src, dst);
586 	}
587 	scr_memmovew(dst, src, (rows - nr) * vc->vc_size_row);
588 	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
589 }
590 
591 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
592 {
593 	unsigned int xx, yy, offset;
594 	u16 *p;
595 
596 	p = (u16 *) start;
597 	if (!vc->vc_sw->con_getxy) {
598 		offset = (start - vc->vc_origin) / 2;
599 		xx = offset % vc->vc_cols;
600 		yy = offset / vc->vc_cols;
601 	} else {
602 		int nxx, nyy;
603 		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
604 		xx = nxx; yy = nyy;
605 	}
606 	for(;;) {
607 		u16 attrib = scr_readw(p) & 0xff00;
608 		int startx = xx;
609 		u16 *q = p;
610 		while (xx < vc->vc_cols && count) {
611 			if (attrib != (scr_readw(p) & 0xff00)) {
612 				if (p > q)
613 					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
614 				startx = xx;
615 				q = p;
616 				attrib = scr_readw(p) & 0xff00;
617 			}
618 			p++;
619 			xx++;
620 			count--;
621 		}
622 		if (p > q)
623 			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
624 		if (!count)
625 			break;
626 		xx = 0;
627 		yy++;
628 		if (vc->vc_sw->con_getxy) {
629 			p = (u16 *)start;
630 			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
631 		}
632 	}
633 }
634 
635 void update_region(struct vc_data *vc, unsigned long start, int count)
636 {
637 	WARN_CONSOLE_UNLOCKED();
638 
639 	if (con_should_update(vc)) {
640 		hide_cursor(vc);
641 		do_update_region(vc, start, count);
642 		set_cursor(vc);
643 	}
644 }
645 EXPORT_SYMBOL(update_region);
646 
647 /* Structure of attributes is hardware-dependent */
648 
649 static u8 build_attr(struct vc_data *vc, u8 _color,
650 		enum vc_intensity _intensity, bool _blink, bool _underline,
651 		bool _reverse, bool _italic)
652 {
653 	if (vc->vc_sw->con_build_attr)
654 		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
655 		       _blink, _underline, _reverse, _italic);
656 
657 /*
658  * ++roman: I completely changed the attribute format for monochrome
659  * mode (!can_do_color). The formerly used MDA (monochrome display
660  * adapter) format didn't allow the combination of certain effects.
661  * Now the attribute is just a bit vector:
662  *  Bit 0..1: intensity (0..2)
663  *  Bit 2   : underline
664  *  Bit 3   : reverse
665  *  Bit 7   : blink
666  */
667 	{
668 	u8 a = _color;
669 	if (!vc->vc_can_do_color)
670 		return _intensity |
671 		       (_italic    << 1) |
672 		       (_underline << 2) |
673 		       (_reverse   << 3) |
674 		       (_blink     << 7);
675 	if (_italic)
676 		a = (a & 0xF0) | vc->vc_itcolor;
677 	else if (_underline)
678 		a = (a & 0xf0) | vc->vc_ulcolor;
679 	else if (_intensity == VCI_HALF_BRIGHT)
680 		a = (a & 0xf0) | vc->vc_halfcolor;
681 	if (_reverse)
682 		a = (a & 0x88) | (((a >> 4) | (a << 4)) & 0x77);
683 	if (_blink)
684 		a ^= 0x80;
685 	if (_intensity == VCI_BOLD)
686 		a ^= 0x08;
687 	if (vc->vc_hi_font_mask == 0x100)
688 		a <<= 1;
689 	return a;
690 	}
691 }
692 
693 static void update_attr(struct vc_data *vc)
694 {
695 	vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
696 	              vc->state.blink, vc->state.underline,
697 	              vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
698 	vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
699 				VCI_NORMAL, vc->state.blink, false,
700 				vc->vc_decscnm, false) << 8);
701 }
702 
703 /* Note: inverting the screen twice should revert to the original state */
704 void invert_screen(struct vc_data *vc, int offset, int count, bool viewed)
705 {
706 	unsigned short *p;
707 
708 	WARN_CONSOLE_UNLOCKED();
709 
710 	count /= 2;
711 	p = screenpos(vc, offset, viewed);
712 	if (vc->vc_sw->con_invert_region) {
713 		vc->vc_sw->con_invert_region(vc, p, count);
714 	} else {
715 		u16 *q = p;
716 		int cnt = count;
717 		u16 a;
718 
719 		if (!vc->vc_can_do_color) {
720 			while (cnt--) {
721 			    a = scr_readw(q);
722 			    a ^= 0x0800;
723 			    scr_writew(a, q);
724 			    q++;
725 			}
726 		} else if (vc->vc_hi_font_mask == 0x100) {
727 			while (cnt--) {
728 				a = scr_readw(q);
729 				a = (a & 0x11ff) |
730 				   ((a & 0xe000) >> 4) |
731 				   ((a & 0x0e00) << 4);
732 				scr_writew(a, q);
733 				q++;
734 			}
735 		} else {
736 			while (cnt--) {
737 				a = scr_readw(q);
738 				a = (a & 0x88ff) |
739 				   ((a & 0x7000) >> 4) |
740 				   ((a & 0x0700) << 4);
741 				scr_writew(a, q);
742 				q++;
743 			}
744 		}
745 	}
746 
747 	if (con_should_update(vc))
748 		do_update_region(vc, (unsigned long) p, count);
749 	notify_update(vc);
750 }
751 
752 /* used by selection: complement pointer position */
753 void complement_pos(struct vc_data *vc, int offset)
754 {
755 	static int old_offset = -1;
756 	static unsigned short old;
757 	static unsigned short oldx, oldy;
758 
759 	WARN_CONSOLE_UNLOCKED();
760 
761 	if (old_offset != -1 && old_offset >= 0 &&
762 	    old_offset < vc->vc_screenbuf_size) {
763 		scr_writew(old, screenpos(vc, old_offset, true));
764 		if (con_should_update(vc))
765 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
766 		notify_update(vc);
767 	}
768 
769 	old_offset = offset;
770 
771 	if (offset != -1 && offset >= 0 &&
772 	    offset < vc->vc_screenbuf_size) {
773 		unsigned short new;
774 		unsigned short *p;
775 		p = screenpos(vc, offset, true);
776 		old = scr_readw(p);
777 		new = old ^ vc->vc_complement_mask;
778 		scr_writew(new, p);
779 		if (con_should_update(vc)) {
780 			oldx = (offset >> 1) % vc->vc_cols;
781 			oldy = (offset >> 1) / vc->vc_cols;
782 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
783 		}
784 		notify_update(vc);
785 	}
786 }
787 
788 static void insert_char(struct vc_data *vc, unsigned int nr)
789 {
790 	unsigned short *p = (unsigned short *) vc->vc_pos;
791 
792 	vc_uniscr_insert(vc, nr);
793 	scr_memmovew(p + nr, p, (vc->vc_cols - vc->state.x - nr) * 2);
794 	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
795 	vc->vc_need_wrap = 0;
796 	if (con_should_update(vc))
797 		do_update_region(vc, (unsigned long) p,
798 			vc->vc_cols - vc->state.x);
799 }
800 
801 static void delete_char(struct vc_data *vc, unsigned int nr)
802 {
803 	unsigned short *p = (unsigned short *) vc->vc_pos;
804 
805 	vc_uniscr_delete(vc, nr);
806 	scr_memmovew(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
807 	scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
808 			nr * 2);
809 	vc->vc_need_wrap = 0;
810 	if (con_should_update(vc))
811 		do_update_region(vc, (unsigned long) p,
812 			vc->vc_cols - vc->state.x);
813 }
814 
815 static int softcursor_original = -1;
816 
817 static void add_softcursor(struct vc_data *vc)
818 {
819 	int i = scr_readw((u16 *) vc->vc_pos);
820 	u32 type = vc->vc_cursor_type;
821 
822 	if (!(type & CUR_SW))
823 		return;
824 	if (softcursor_original != -1)
825 		return;
826 	softcursor_original = i;
827 	i |= CUR_SET(type);
828 	i ^= CUR_CHANGE(type);
829 	if ((type & CUR_ALWAYS_BG) &&
830 			(softcursor_original & CUR_BG) == (i & CUR_BG))
831 		i ^= CUR_BG;
832 	if ((type & CUR_INVERT_FG_BG) && (i & CUR_FG) == ((i & CUR_BG) >> 4))
833 		i ^= CUR_FG;
834 	scr_writew(i, (u16 *)vc->vc_pos);
835 	if (con_should_update(vc))
836 		vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
837 }
838 
839 static void hide_softcursor(struct vc_data *vc)
840 {
841 	if (softcursor_original != -1) {
842 		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
843 		if (con_should_update(vc))
844 			vc->vc_sw->con_putc(vc, softcursor_original,
845 					vc->state.y, vc->state.x);
846 		softcursor_original = -1;
847 	}
848 }
849 
850 static void hide_cursor(struct vc_data *vc)
851 {
852 	if (vc_is_sel(vc))
853 		clear_selection();
854 
855 	vc->vc_sw->con_cursor(vc, CM_ERASE);
856 	hide_softcursor(vc);
857 }
858 
859 static void set_cursor(struct vc_data *vc)
860 {
861 	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
862 		return;
863 	if (vc->vc_deccm) {
864 		if (vc_is_sel(vc))
865 			clear_selection();
866 		add_softcursor(vc);
867 		if (CUR_SIZE(vc->vc_cursor_type) != CUR_NONE)
868 			vc->vc_sw->con_cursor(vc, CM_DRAW);
869 	} else
870 		hide_cursor(vc);
871 }
872 
873 static void set_origin(struct vc_data *vc)
874 {
875 	WARN_CONSOLE_UNLOCKED();
876 
877 	if (!con_is_visible(vc) ||
878 	    !vc->vc_sw->con_set_origin ||
879 	    !vc->vc_sw->con_set_origin(vc))
880 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
881 	vc->vc_visible_origin = vc->vc_origin;
882 	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
883 	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->state.y +
884 		2 * vc->state.x;
885 }
886 
887 static void save_screen(struct vc_data *vc)
888 {
889 	WARN_CONSOLE_UNLOCKED();
890 
891 	if (vc->vc_sw->con_save_screen)
892 		vc->vc_sw->con_save_screen(vc);
893 }
894 
895 static void flush_scrollback(struct vc_data *vc)
896 {
897 	WARN_CONSOLE_UNLOCKED();
898 
899 	set_origin(vc);
900 	if (vc->vc_sw->con_flush_scrollback) {
901 		vc->vc_sw->con_flush_scrollback(vc);
902 	} else if (con_is_visible(vc)) {
903 		/*
904 		 * When no con_flush_scrollback method is provided then the
905 		 * legacy way for flushing the scrollback buffer is to use
906 		 * a side effect of the con_switch method. We do it only on
907 		 * the foreground console as background consoles have no
908 		 * scrollback buffers in that case and we obviously don't
909 		 * want to switch to them.
910 		 */
911 		hide_cursor(vc);
912 		vc->vc_sw->con_switch(vc);
913 		set_cursor(vc);
914 	}
915 }
916 
917 /*
918  *	Redrawing of screen
919  */
920 
921 void clear_buffer_attributes(struct vc_data *vc)
922 {
923 	unsigned short *p = (unsigned short *)vc->vc_origin;
924 	int count = vc->vc_screenbuf_size / 2;
925 	int mask = vc->vc_hi_font_mask | 0xff;
926 
927 	for (; count > 0; count--, p++) {
928 		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
929 	}
930 }
931 
932 void redraw_screen(struct vc_data *vc, int is_switch)
933 {
934 	int redraw = 0;
935 
936 	WARN_CONSOLE_UNLOCKED();
937 
938 	if (!vc) {
939 		/* strange ... */
940 		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
941 		return;
942 	}
943 
944 	if (is_switch) {
945 		struct vc_data *old_vc = vc_cons[fg_console].d;
946 		if (old_vc == vc)
947 			return;
948 		if (!con_is_visible(vc))
949 			redraw = 1;
950 		*vc->vc_display_fg = vc;
951 		fg_console = vc->vc_num;
952 		hide_cursor(old_vc);
953 		if (!con_is_visible(old_vc)) {
954 			save_screen(old_vc);
955 			set_origin(old_vc);
956 		}
957 		if (tty0dev)
958 			sysfs_notify(&tty0dev->kobj, NULL, "active");
959 	} else {
960 		hide_cursor(vc);
961 		redraw = 1;
962 	}
963 
964 	if (redraw) {
965 		int update;
966 		int old_was_color = vc->vc_can_do_color;
967 
968 		set_origin(vc);
969 		update = vc->vc_sw->con_switch(vc);
970 		set_palette(vc);
971 		/*
972 		 * If console changed from mono<->color, the best we can do
973 		 * is to clear the buffer attributes. As it currently stands,
974 		 * rebuilding new attributes from the old buffer is not doable
975 		 * without overly complex code.
976 		 */
977 		if (old_was_color != vc->vc_can_do_color) {
978 			update_attr(vc);
979 			clear_buffer_attributes(vc);
980 		}
981 
982 		if (update && vc->vc_mode != KD_GRAPHICS)
983 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
984 	}
985 	set_cursor(vc);
986 	if (is_switch) {
987 		vt_set_leds_compute_shiftstate();
988 		notify_update(vc);
989 	}
990 }
991 EXPORT_SYMBOL(redraw_screen);
992 
993 /*
994  *	Allocation, freeing and resizing of VTs.
995  */
996 
997 int vc_cons_allocated(unsigned int i)
998 {
999 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1000 }
1001 
1002 static void visual_init(struct vc_data *vc, int num, int init)
1003 {
1004 	/* ++Geert: vc->vc_sw->con_init determines console size */
1005 	if (vc->vc_sw)
1006 		module_put(vc->vc_sw->owner);
1007 	vc->vc_sw = conswitchp;
1008 
1009 	if (con_driver_map[num])
1010 		vc->vc_sw = con_driver_map[num];
1011 
1012 	__module_get(vc->vc_sw->owner);
1013 	vc->vc_num = num;
1014 	vc->vc_display_fg = &master_display_fg;
1015 	if (vc->uni_pagedict_loc)
1016 		con_free_unimap(vc);
1017 	vc->uni_pagedict_loc = &vc->uni_pagedict;
1018 	vc->uni_pagedict = NULL;
1019 	vc->vc_hi_font_mask = 0;
1020 	vc->vc_complement_mask = 0;
1021 	vc->vc_can_do_color = 0;
1022 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1023 	vc->vc_sw->con_init(vc, init);
1024 	if (!vc->vc_complement_mask)
1025 		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1026 	vc->vc_s_complement_mask = vc->vc_complement_mask;
1027 	vc->vc_size_row = vc->vc_cols << 1;
1028 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1029 }
1030 
1031 
1032 static void visual_deinit(struct vc_data *vc)
1033 {
1034 	vc->vc_sw->con_deinit(vc);
1035 	module_put(vc->vc_sw->owner);
1036 }
1037 
1038 static void vc_port_destruct(struct tty_port *port)
1039 {
1040 	struct vc_data *vc = container_of(port, struct vc_data, port);
1041 
1042 	kfree(vc);
1043 }
1044 
1045 static const struct tty_port_operations vc_port_ops = {
1046 	.destruct = vc_port_destruct,
1047 };
1048 
1049 /*
1050  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1051  * [this is to be used together with some user program
1052  * like resize that changes the hardware videomode]
1053  */
1054 #define VC_MAXCOL (32767)
1055 #define VC_MAXROW (32767)
1056 
1057 int vc_allocate(unsigned int currcons)	/* return 0 on success */
1058 {
1059 	struct vt_notifier_param param;
1060 	struct vc_data *vc;
1061 	int err;
1062 
1063 	WARN_CONSOLE_UNLOCKED();
1064 
1065 	if (currcons >= MAX_NR_CONSOLES)
1066 		return -ENXIO;
1067 
1068 	if (vc_cons[currcons].d)
1069 		return 0;
1070 
1071 	/* due to the granularity of kmalloc, we waste some memory here */
1072 	/* the alloc is done in two steps, to optimize the common situation
1073 	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
1074 	/* although the numbers above are not valid since long ago, the
1075 	   point is still up-to-date and the comment still has its value
1076 	   even if only as a historical artifact.  --mj, July 1998 */
1077 	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1078 	if (!vc)
1079 		return -ENOMEM;
1080 
1081 	vc_cons[currcons].d = vc;
1082 	tty_port_init(&vc->port);
1083 	vc->port.ops = &vc_port_ops;
1084 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1085 
1086 	visual_init(vc, currcons, 1);
1087 
1088 	if (!*vc->uni_pagedict_loc)
1089 		con_set_default_unimap(vc);
1090 
1091 	err = -EINVAL;
1092 	if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
1093 	    vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
1094 		goto err_free;
1095 	err = -ENOMEM;
1096 	vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1097 	if (!vc->vc_screenbuf)
1098 		goto err_free;
1099 
1100 	/* If no drivers have overridden us and the user didn't pass a
1101 	   boot option, default to displaying the cursor */
1102 	if (global_cursor_default == -1)
1103 		global_cursor_default = 1;
1104 
1105 	vc_init(vc, 1);
1106 	vcs_make_sysfs(currcons);
1107 	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1108 
1109 	return 0;
1110 err_free:
1111 	visual_deinit(vc);
1112 	kfree(vc);
1113 	vc_cons[currcons].d = NULL;
1114 	return err;
1115 }
1116 
1117 static inline int resize_screen(struct vc_data *vc, int width, int height,
1118 				int user)
1119 {
1120 	/* Resizes the resolution of the display adapater */
1121 	int err = 0;
1122 
1123 	if (vc->vc_sw->con_resize)
1124 		err = vc->vc_sw->con_resize(vc, width, height, user);
1125 
1126 	return err;
1127 }
1128 
1129 /**
1130  *	vc_do_resize	-	resizing method for the tty
1131  *	@tty: tty being resized
1132  *	@vc: virtual console private data
1133  *	@cols: columns
1134  *	@lines: lines
1135  *
1136  *	Resize a virtual console, clipping according to the actual constraints.
1137  *	If the caller passes a tty structure then update the termios winsize
1138  *	information and perform any necessary signal handling.
1139  *
1140  *	Caller must hold the console semaphore. Takes the termios rwsem and
1141  *	ctrl.lock of the tty IFF a tty is passed.
1142  */
1143 
1144 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1145 				unsigned int cols, unsigned int lines)
1146 {
1147 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1148 	unsigned long end;
1149 	unsigned int old_rows, old_row_size, first_copied_row;
1150 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1151 	unsigned int user;
1152 	unsigned short *oldscreen, *newscreen;
1153 	u32 **new_uniscr = NULL;
1154 
1155 	WARN_CONSOLE_UNLOCKED();
1156 
1157 	if (!vc)
1158 		return -ENXIO;
1159 
1160 	user = vc->vc_resize_user;
1161 	vc->vc_resize_user = 0;
1162 
1163 	if (cols > VC_MAXCOL || lines > VC_MAXROW)
1164 		return -EINVAL;
1165 
1166 	new_cols = (cols ? cols : vc->vc_cols);
1167 	new_rows = (lines ? lines : vc->vc_rows);
1168 	new_row_size = new_cols << 1;
1169 	new_screen_size = new_row_size * new_rows;
1170 
1171 	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) {
1172 		/*
1173 		 * This function is being called here to cover the case
1174 		 * where the userspace calls the FBIOPUT_VSCREENINFO twice,
1175 		 * passing the same fb_var_screeninfo containing the fields
1176 		 * yres/xres equal to a number non-multiple of vc_font.height
1177 		 * and yres_virtual/xres_virtual equal to number lesser than the
1178 		 * vc_font.height and yres/xres.
1179 		 * In the second call, the struct fb_var_screeninfo isn't
1180 		 * being modified by the underlying driver because of the
1181 		 * if above, and this causes the fbcon_display->vrows to become
1182 		 * negative and it eventually leads to out-of-bound
1183 		 * access by the imageblit function.
1184 		 * To give the correct values to the struct and to not have
1185 		 * to deal with possible errors from the code below, we call
1186 		 * the resize_screen here as well.
1187 		 */
1188 		return resize_screen(vc, new_cols, new_rows, user);
1189 	}
1190 
1191 	if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
1192 		return -EINVAL;
1193 	newscreen = kzalloc(new_screen_size, GFP_USER);
1194 	if (!newscreen)
1195 		return -ENOMEM;
1196 
1197 	if (vc->vc_uni_lines) {
1198 		new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1199 		if (!new_uniscr) {
1200 			kfree(newscreen);
1201 			return -ENOMEM;
1202 		}
1203 	}
1204 
1205 	if (vc_is_sel(vc))
1206 		clear_selection();
1207 
1208 	old_rows = vc->vc_rows;
1209 	old_row_size = vc->vc_size_row;
1210 
1211 	err = resize_screen(vc, new_cols, new_rows, user);
1212 	if (err) {
1213 		kfree(newscreen);
1214 		vc_uniscr_free(new_uniscr);
1215 		return err;
1216 	}
1217 
1218 	vc->vc_rows = new_rows;
1219 	vc->vc_cols = new_cols;
1220 	vc->vc_size_row = new_row_size;
1221 	vc->vc_screenbuf_size = new_screen_size;
1222 
1223 	rlth = min(old_row_size, new_row_size);
1224 	rrem = new_row_size - rlth;
1225 	old_origin = vc->vc_origin;
1226 	new_origin = (long) newscreen;
1227 	new_scr_end = new_origin + new_screen_size;
1228 
1229 	if (vc->state.y > new_rows) {
1230 		if (old_rows - vc->state.y < new_rows) {
1231 			/*
1232 			 * Cursor near the bottom, copy contents from the
1233 			 * bottom of buffer
1234 			 */
1235 			first_copied_row = (old_rows - new_rows);
1236 		} else {
1237 			/*
1238 			 * Cursor is in no man's land, copy 1/2 screenful
1239 			 * from the top and bottom of cursor position
1240 			 */
1241 			first_copied_row = (vc->state.y - new_rows/2);
1242 		}
1243 		old_origin += first_copied_row * old_row_size;
1244 	} else
1245 		first_copied_row = 0;
1246 	end = old_origin + old_row_size * min(old_rows, new_rows);
1247 
1248 	vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1249 			    vc->vc_uni_lines, rlth/2, first_copied_row,
1250 			    min(old_rows, new_rows));
1251 	vc_uniscr_set(vc, new_uniscr);
1252 
1253 	update_attr(vc);
1254 
1255 	while (old_origin < end) {
1256 		scr_memcpyw((unsigned short *) new_origin,
1257 			    (unsigned short *) old_origin, rlth);
1258 		if (rrem)
1259 			scr_memsetw((void *)(new_origin + rlth),
1260 				    vc->vc_video_erase_char, rrem);
1261 		old_origin += old_row_size;
1262 		new_origin += new_row_size;
1263 	}
1264 	if (new_scr_end > new_origin)
1265 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1266 			    new_scr_end - new_origin);
1267 	oldscreen = vc->vc_screenbuf;
1268 	vc->vc_screenbuf = newscreen;
1269 	vc->vc_screenbuf_size = new_screen_size;
1270 	set_origin(vc);
1271 	kfree(oldscreen);
1272 
1273 	/* do part of a reset_terminal() */
1274 	vc->vc_top = 0;
1275 	vc->vc_bottom = vc->vc_rows;
1276 	gotoxy(vc, vc->state.x, vc->state.y);
1277 	save_cur(vc);
1278 
1279 	if (tty) {
1280 		/* Rewrite the requested winsize data with the actual
1281 		   resulting sizes */
1282 		struct winsize ws;
1283 		memset(&ws, 0, sizeof(ws));
1284 		ws.ws_row = vc->vc_rows;
1285 		ws.ws_col = vc->vc_cols;
1286 		ws.ws_ypixel = vc->vc_scan_lines;
1287 		tty_do_resize(tty, &ws);
1288 	}
1289 
1290 	if (con_is_visible(vc))
1291 		update_screen(vc);
1292 	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1293 	notify_update(vc);
1294 	return err;
1295 }
1296 
1297 /**
1298  *	vc_resize		-	resize a VT
1299  *	@vc: virtual console
1300  *	@cols: columns
1301  *	@rows: rows
1302  *
1303  *	Resize a virtual console as seen from the console end of things. We
1304  *	use the common vc_do_resize methods to update the structures. The
1305  *	caller must hold the console sem to protect console internals and
1306  *	vc->port.tty
1307  */
1308 
1309 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1310 {
1311 	return vc_do_resize(vc->port.tty, vc, cols, rows);
1312 }
1313 EXPORT_SYMBOL(vc_resize);
1314 
1315 /**
1316  *	vt_resize		-	resize a VT
1317  *	@tty: tty to resize
1318  *	@ws: winsize attributes
1319  *
1320  *	Resize a virtual terminal. This is called by the tty layer as we
1321  *	register our own handler for resizing. The mutual helper does all
1322  *	the actual work.
1323  *
1324  *	Takes the console sem and the called methods then take the tty
1325  *	termios_rwsem and the tty ctrl.lock in that order.
1326  */
1327 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1328 {
1329 	struct vc_data *vc = tty->driver_data;
1330 	int ret;
1331 
1332 	console_lock();
1333 	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1334 	console_unlock();
1335 	return ret;
1336 }
1337 
1338 struct vc_data *vc_deallocate(unsigned int currcons)
1339 {
1340 	struct vc_data *vc = NULL;
1341 
1342 	WARN_CONSOLE_UNLOCKED();
1343 
1344 	if (vc_cons_allocated(currcons)) {
1345 		struct vt_notifier_param param;
1346 
1347 		param.vc = vc = vc_cons[currcons].d;
1348 		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1349 		vcs_remove_sysfs(currcons);
1350 		visual_deinit(vc);
1351 		con_free_unimap(vc);
1352 		put_pid(vc->vt_pid);
1353 		vc_uniscr_set(vc, NULL);
1354 		kfree(vc->vc_screenbuf);
1355 		vc_cons[currcons].d = NULL;
1356 	}
1357 	return vc;
1358 }
1359 
1360 /*
1361  *	VT102 emulator
1362  */
1363 
1364 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1365 
1366 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1367 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1368 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1369 
1370 #define decarm		VC_REPEAT
1371 #define decckm		VC_CKMODE
1372 #define kbdapplic	VC_APPLIC
1373 #define lnm		VC_CRLF
1374 
1375 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1376 				       8,12,10,14, 9,13,11,15 };
1377 EXPORT_SYMBOL(color_table);
1378 
1379 /* the default colour table, for VGA+ colour systems */
1380 unsigned char default_red[] = {
1381 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1382 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1383 };
1384 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1385 EXPORT_SYMBOL(default_red);
1386 
1387 unsigned char default_grn[] = {
1388 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1389 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1390 };
1391 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1392 EXPORT_SYMBOL(default_grn);
1393 
1394 unsigned char default_blu[] = {
1395 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1396 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1397 };
1398 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1399 EXPORT_SYMBOL(default_blu);
1400 
1401 /*
1402  * gotoxy() must verify all boundaries, because the arguments
1403  * might also be negative. If the given position is out of
1404  * bounds, the cursor is placed at the nearest margin.
1405  */
1406 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1407 {
1408 	int min_y, max_y;
1409 
1410 	if (new_x < 0)
1411 		vc->state.x = 0;
1412 	else {
1413 		if (new_x >= vc->vc_cols)
1414 			vc->state.x = vc->vc_cols - 1;
1415 		else
1416 			vc->state.x = new_x;
1417 	}
1418 
1419  	if (vc->vc_decom) {
1420 		min_y = vc->vc_top;
1421 		max_y = vc->vc_bottom;
1422 	} else {
1423 		min_y = 0;
1424 		max_y = vc->vc_rows;
1425 	}
1426 	if (new_y < min_y)
1427 		vc->state.y = min_y;
1428 	else if (new_y >= max_y)
1429 		vc->state.y = max_y - 1;
1430 	else
1431 		vc->state.y = new_y;
1432 	vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
1433 		(vc->state.x << 1);
1434 	vc->vc_need_wrap = 0;
1435 }
1436 
1437 /* for absolute user moves, when decom is set */
1438 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1439 {
1440 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1441 }
1442 
1443 void scrollback(struct vc_data *vc)
1444 {
1445 	scrolldelta(-(vc->vc_rows / 2));
1446 }
1447 
1448 void scrollfront(struct vc_data *vc, int lines)
1449 {
1450 	if (!lines)
1451 		lines = vc->vc_rows / 2;
1452 	scrolldelta(lines);
1453 }
1454 
1455 static void lf(struct vc_data *vc)
1456 {
1457     	/* don't scroll if above bottom of scrolling region, or
1458 	 * if below scrolling region
1459 	 */
1460 	if (vc->state.y + 1 == vc->vc_bottom)
1461 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1462 	else if (vc->state.y < vc->vc_rows - 1) {
1463 		vc->state.y++;
1464 		vc->vc_pos += vc->vc_size_row;
1465 	}
1466 	vc->vc_need_wrap = 0;
1467 	notify_write(vc, '\n');
1468 }
1469 
1470 static void ri(struct vc_data *vc)
1471 {
1472     	/* don't scroll if below top of scrolling region, or
1473 	 * if above scrolling region
1474 	 */
1475 	if (vc->state.y == vc->vc_top)
1476 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1477 	else if (vc->state.y > 0) {
1478 		vc->state.y--;
1479 		vc->vc_pos -= vc->vc_size_row;
1480 	}
1481 	vc->vc_need_wrap = 0;
1482 }
1483 
1484 static inline void cr(struct vc_data *vc)
1485 {
1486 	vc->vc_pos -= vc->state.x << 1;
1487 	vc->vc_need_wrap = vc->state.x = 0;
1488 	notify_write(vc, '\r');
1489 }
1490 
1491 static inline void bs(struct vc_data *vc)
1492 {
1493 	if (vc->state.x) {
1494 		vc->vc_pos -= 2;
1495 		vc->state.x--;
1496 		vc->vc_need_wrap = 0;
1497 		notify_write(vc, '\b');
1498 	}
1499 }
1500 
1501 static inline void del(struct vc_data *vc)
1502 {
1503 	/* ignored */
1504 }
1505 
1506 static void csi_J(struct vc_data *vc, int vpar)
1507 {
1508 	unsigned int count;
1509 	unsigned short * start;
1510 
1511 	switch (vpar) {
1512 		case 0:	/* erase from cursor to end of display */
1513 			vc_uniscr_clear_line(vc, vc->state.x,
1514 					     vc->vc_cols - vc->state.x);
1515 			vc_uniscr_clear_lines(vc, vc->state.y + 1,
1516 					      vc->vc_rows - vc->state.y - 1);
1517 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1518 			start = (unsigned short *)vc->vc_pos;
1519 			break;
1520 		case 1:	/* erase from start to cursor */
1521 			vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
1522 			vc_uniscr_clear_lines(vc, 0, vc->state.y);
1523 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1524 			start = (unsigned short *)vc->vc_origin;
1525 			break;
1526 		case 3: /* include scrollback */
1527 			flush_scrollback(vc);
1528 			fallthrough;
1529 		case 2: /* erase whole display */
1530 			vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1531 			count = vc->vc_cols * vc->vc_rows;
1532 			start = (unsigned short *)vc->vc_origin;
1533 			break;
1534 		default:
1535 			return;
1536 	}
1537 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1538 	if (con_should_update(vc))
1539 		do_update_region(vc, (unsigned long) start, count);
1540 	vc->vc_need_wrap = 0;
1541 }
1542 
1543 static void csi_K(struct vc_data *vc, int vpar)
1544 {
1545 	unsigned int count;
1546 	unsigned short *start = (unsigned short *)vc->vc_pos;
1547 	int offset;
1548 
1549 	switch (vpar) {
1550 		case 0:	/* erase from cursor to end of line */
1551 			offset = 0;
1552 			count = vc->vc_cols - vc->state.x;
1553 			break;
1554 		case 1:	/* erase from start of line to cursor */
1555 			offset = -vc->state.x;
1556 			count = vc->state.x + 1;
1557 			break;
1558 		case 2: /* erase whole line */
1559 			offset = -vc->state.x;
1560 			count = vc->vc_cols;
1561 			break;
1562 		default:
1563 			return;
1564 	}
1565 	vc_uniscr_clear_line(vc, vc->state.x + offset, count);
1566 	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1567 	vc->vc_need_wrap = 0;
1568 	if (con_should_update(vc))
1569 		do_update_region(vc, (unsigned long)(start + offset), count);
1570 }
1571 
1572 /* erase the following vpar positions */
1573 static void csi_X(struct vc_data *vc, unsigned int vpar)
1574 {					  /* not vt100? */
1575 	unsigned int count;
1576 
1577 	if (!vpar)
1578 		vpar++;
1579 
1580 	count = min(vpar, vc->vc_cols - vc->state.x);
1581 
1582 	vc_uniscr_clear_line(vc, vc->state.x, count);
1583 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1584 	if (con_should_update(vc))
1585 		vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
1586 	vc->vc_need_wrap = 0;
1587 }
1588 
1589 static void default_attr(struct vc_data *vc)
1590 {
1591 	vc->state.intensity = VCI_NORMAL;
1592 	vc->state.italic = false;
1593 	vc->state.underline = false;
1594 	vc->state.reverse = false;
1595 	vc->state.blink = false;
1596 	vc->state.color = vc->vc_def_color;
1597 }
1598 
1599 struct rgb { u8 r; u8 g; u8 b; };
1600 
1601 static void rgb_from_256(int i, struct rgb *c)
1602 {
1603 	if (i < 8) {            /* Standard colours. */
1604 		c->r = i&1 ? 0xaa : 0x00;
1605 		c->g = i&2 ? 0xaa : 0x00;
1606 		c->b = i&4 ? 0xaa : 0x00;
1607 	} else if (i < 16) {
1608 		c->r = i&1 ? 0xff : 0x55;
1609 		c->g = i&2 ? 0xff : 0x55;
1610 		c->b = i&4 ? 0xff : 0x55;
1611 	} else if (i < 232) {   /* 6x6x6 colour cube. */
1612 		c->r = (i - 16) / 36 * 85 / 2;
1613 		c->g = (i - 16) / 6 % 6 * 85 / 2;
1614 		c->b = (i - 16) % 6 * 85 / 2;
1615 	} else                  /* Grayscale ramp. */
1616 		c->r = c->g = c->b = i * 10 - 2312;
1617 }
1618 
1619 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1620 {
1621 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1622 
1623 	if (c->r > max / 2)
1624 		hue |= 4;
1625 	if (c->g > max / 2)
1626 		hue |= 2;
1627 	if (c->b > max / 2)
1628 		hue |= 1;
1629 
1630 	if (hue == 7 && max <= 0x55) {
1631 		hue = 0;
1632 		vc->state.intensity = VCI_BOLD;
1633 	} else if (max > 0xaa)
1634 		vc->state.intensity = VCI_BOLD;
1635 	else
1636 		vc->state.intensity = VCI_NORMAL;
1637 
1638 	vc->state.color = (vc->state.color & 0xf0) | hue;
1639 }
1640 
1641 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1642 {
1643 	/* For backgrounds, err on the dark side. */
1644 	vc->state.color = (vc->state.color & 0x0f)
1645 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1646 }
1647 
1648 /*
1649  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1650  * and thus need to be detected and ignored by hand. That standard also
1651  * wants : rather than ; as separators but sequences containing : are currently
1652  * completely ignored by the parser.
1653  *
1654  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1655  * supporting them.
1656  */
1657 static int vc_t416_color(struct vc_data *vc, int i,
1658 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1659 {
1660 	struct rgb c;
1661 
1662 	i++;
1663 	if (i > vc->vc_npar)
1664 		return i;
1665 
1666 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1667 		/* 256 colours */
1668 		i++;
1669 		rgb_from_256(vc->vc_par[i], &c);
1670 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1671 		/* 24 bit */
1672 		c.r = vc->vc_par[i + 1];
1673 		c.g = vc->vc_par[i + 2];
1674 		c.b = vc->vc_par[i + 3];
1675 		i += 3;
1676 	} else
1677 		return i;
1678 
1679 	set_color(vc, &c);
1680 
1681 	return i;
1682 }
1683 
1684 /* console_lock is held */
1685 static void csi_m(struct vc_data *vc)
1686 {
1687 	int i;
1688 
1689 	for (i = 0; i <= vc->vc_npar; i++)
1690 		switch (vc->vc_par[i]) {
1691 		case 0:	/* all attributes off */
1692 			default_attr(vc);
1693 			break;
1694 		case 1:
1695 			vc->state.intensity = VCI_BOLD;
1696 			break;
1697 		case 2:
1698 			vc->state.intensity = VCI_HALF_BRIGHT;
1699 			break;
1700 		case 3:
1701 			vc->state.italic = true;
1702 			break;
1703 		case 21:
1704 			/*
1705 			 * No console drivers support double underline, so
1706 			 * convert it to a single underline.
1707 			 */
1708 		case 4:
1709 			vc->state.underline = true;
1710 			break;
1711 		case 5:
1712 			vc->state.blink = true;
1713 			break;
1714 		case 7:
1715 			vc->state.reverse = true;
1716 			break;
1717 		case 10: /* ANSI X3.64-1979 (SCO-ish?)
1718 			  * Select primary font, don't display control chars if
1719 			  * defined, don't set bit 8 on output.
1720 			  */
1721 			vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset], vc);
1722 			vc->vc_disp_ctrl = 0;
1723 			vc->vc_toggle_meta = 0;
1724 			break;
1725 		case 11: /* ANSI X3.64-1979 (SCO-ish?)
1726 			  * Select first alternate font, lets chars < 32 be
1727 			  * displayed as ROM chars.
1728 			  */
1729 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1730 			vc->vc_disp_ctrl = 1;
1731 			vc->vc_toggle_meta = 0;
1732 			break;
1733 		case 12: /* ANSI X3.64-1979 (SCO-ish?)
1734 			  * Select second alternate font, toggle high bit
1735 			  * before displaying as ROM char.
1736 			  */
1737 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1738 			vc->vc_disp_ctrl = 1;
1739 			vc->vc_toggle_meta = 1;
1740 			break;
1741 		case 22:
1742 			vc->state.intensity = VCI_NORMAL;
1743 			break;
1744 		case 23:
1745 			vc->state.italic = false;
1746 			break;
1747 		case 24:
1748 			vc->state.underline = false;
1749 			break;
1750 		case 25:
1751 			vc->state.blink = false;
1752 			break;
1753 		case 27:
1754 			vc->state.reverse = false;
1755 			break;
1756 		case 38:
1757 			i = vc_t416_color(vc, i, rgb_foreground);
1758 			break;
1759 		case 48:
1760 			i = vc_t416_color(vc, i, rgb_background);
1761 			break;
1762 		case 39:
1763 			vc->state.color = (vc->vc_def_color & 0x0f) |
1764 				(vc->state.color & 0xf0);
1765 			break;
1766 		case 49:
1767 			vc->state.color = (vc->vc_def_color & 0xf0) |
1768 				(vc->state.color & 0x0f);
1769 			break;
1770 		default:
1771 			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1772 				if (vc->vc_par[i] < 100)
1773 					vc->state.intensity = VCI_BOLD;
1774 				vc->vc_par[i] -= 60;
1775 			}
1776 			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1777 				vc->state.color = color_table[vc->vc_par[i] - 30]
1778 					| (vc->state.color & 0xf0);
1779 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1780 				vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
1781 					| (vc->state.color & 0x0f);
1782 			break;
1783 		}
1784 	update_attr(vc);
1785 }
1786 
1787 static void respond_string(const char *p, size_t len, struct tty_port *port)
1788 {
1789 	tty_insert_flip_string(port, p, len);
1790 	tty_flip_buffer_push(port);
1791 }
1792 
1793 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1794 {
1795 	char buf[40];
1796 	int len;
1797 
1798 	len = sprintf(buf, "\033[%d;%dR", vc->state.y +
1799 			(vc->vc_decom ? vc->vc_top + 1 : 1),
1800 			vc->state.x + 1);
1801 	respond_string(buf, len, tty->port);
1802 }
1803 
1804 static inline void status_report(struct tty_struct *tty)
1805 {
1806 	static const char teminal_ok[] = "\033[0n";
1807 
1808 	respond_string(teminal_ok, strlen(teminal_ok), tty->port);
1809 }
1810 
1811 static inline void respond_ID(struct tty_struct *tty)
1812 {
1813 	/* terminal answer to an ESC-Z or csi0c query. */
1814 	static const char vt102_id[] = "\033[?6c";
1815 
1816 	respond_string(vt102_id, strlen(vt102_id), tty->port);
1817 }
1818 
1819 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1820 {
1821 	char buf[8];
1822 	int len;
1823 
1824 	len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
1825 			(char)('!' + mrx), (char)('!' + mry));
1826 	respond_string(buf, len, tty->port);
1827 }
1828 
1829 /* invoked via ioctl(TIOCLINUX) and through set_selection_user */
1830 int mouse_reporting(void)
1831 {
1832 	return vc_cons[fg_console].d->vc_report_mouse;
1833 }
1834 
1835 /* console_lock is held */
1836 static void set_mode(struct vc_data *vc, int on_off)
1837 {
1838 	int i;
1839 
1840 	for (i = 0; i <= vc->vc_npar; i++)
1841 		if (vc->vc_priv == EPdec) {
1842 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1843 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1844 				if (on_off)
1845 					set_kbd(vc, decckm);
1846 				else
1847 					clr_kbd(vc, decckm);
1848 				break;
1849 			case 3:	/* 80/132 mode switch unimplemented */
1850 #if 0
1851 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1852 				/* this alone does not suffice; some user mode
1853 				   utility has to change the hardware regs */
1854 #endif
1855 				break;
1856 			case 5:			/* Inverted screen on/off */
1857 				if (vc->vc_decscnm != on_off) {
1858 					vc->vc_decscnm = on_off;
1859 					invert_screen(vc, 0,
1860 							vc->vc_screenbuf_size,
1861 							false);
1862 					update_attr(vc);
1863 				}
1864 				break;
1865 			case 6:			/* Origin relative/absolute */
1866 				vc->vc_decom = on_off;
1867 				gotoxay(vc, 0, 0);
1868 				break;
1869 			case 7:			/* Autowrap on/off */
1870 				vc->vc_decawm = on_off;
1871 				break;
1872 			case 8:			/* Autorepeat on/off */
1873 				if (on_off)
1874 					set_kbd(vc, decarm);
1875 				else
1876 					clr_kbd(vc, decarm);
1877 				break;
1878 			case 9:
1879 				vc->vc_report_mouse = on_off ? 1 : 0;
1880 				break;
1881 			case 25:		/* Cursor on/off */
1882 				vc->vc_deccm = on_off;
1883 				break;
1884 			case 1000:
1885 				vc->vc_report_mouse = on_off ? 2 : 0;
1886 				break;
1887 			}
1888 		} else {
1889 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1890 			case 3:			/* Monitor (display ctrls) */
1891 				vc->vc_disp_ctrl = on_off;
1892 				break;
1893 			case 4:			/* Insert Mode on/off */
1894 				vc->vc_decim = on_off;
1895 				break;
1896 			case 20:		/* Lf, Enter == CrLf/Lf */
1897 				if (on_off)
1898 					set_kbd(vc, lnm);
1899 				else
1900 					clr_kbd(vc, lnm);
1901 				break;
1902 			}
1903 		}
1904 }
1905 
1906 /* console_lock is held */
1907 static void setterm_command(struct vc_data *vc)
1908 {
1909 	switch (vc->vc_par[0]) {
1910 	case 1:	/* set color for underline mode */
1911 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1912 			vc->vc_ulcolor = color_table[vc->vc_par[1]];
1913 			if (vc->state.underline)
1914 				update_attr(vc);
1915 		}
1916 		break;
1917 	case 2:	/* set color for half intensity mode */
1918 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1919 			vc->vc_halfcolor = color_table[vc->vc_par[1]];
1920 			if (vc->state.intensity == VCI_HALF_BRIGHT)
1921 				update_attr(vc);
1922 		}
1923 		break;
1924 	case 8:	/* store colors as defaults */
1925 		vc->vc_def_color = vc->vc_attr;
1926 		if (vc->vc_hi_font_mask == 0x100)
1927 			vc->vc_def_color >>= 1;
1928 		default_attr(vc);
1929 		update_attr(vc);
1930 		break;
1931 	case 9:	/* set blanking interval */
1932 		blankinterval = min(vc->vc_par[1], 60U) * 60;
1933 		poke_blanked_console();
1934 		break;
1935 	case 10: /* set bell frequency in Hz */
1936 		if (vc->vc_npar >= 1)
1937 			vc->vc_bell_pitch = vc->vc_par[1];
1938 		else
1939 			vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1940 		break;
1941 	case 11: /* set bell duration in msec */
1942 		if (vc->vc_npar >= 1)
1943 			vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1944 				msecs_to_jiffies(vc->vc_par[1]) : 0;
1945 		else
1946 			vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1947 		break;
1948 	case 12: /* bring specified console to the front */
1949 		if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1950 			set_console(vc->vc_par[1] - 1);
1951 		break;
1952 	case 13: /* unblank the screen */
1953 		poke_blanked_console();
1954 		break;
1955 	case 14: /* set vesa powerdown interval */
1956 		vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
1957 		break;
1958 	case 15: /* activate the previous console */
1959 		set_console(last_console);
1960 		break;
1961 	case 16: /* set cursor blink duration in msec */
1962 		if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1963 				vc->vc_par[1] <= USHRT_MAX)
1964 			vc->vc_cur_blink_ms = vc->vc_par[1];
1965 		else
1966 			vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1967 		break;
1968 	}
1969 }
1970 
1971 /* console_lock is held */
1972 static void csi_at(struct vc_data *vc, unsigned int nr)
1973 {
1974 	if (nr > vc->vc_cols - vc->state.x)
1975 		nr = vc->vc_cols - vc->state.x;
1976 	else if (!nr)
1977 		nr = 1;
1978 	insert_char(vc, nr);
1979 }
1980 
1981 /* console_lock is held */
1982 static void csi_L(struct vc_data *vc, unsigned int nr)
1983 {
1984 	if (nr > vc->vc_rows - vc->state.y)
1985 		nr = vc->vc_rows - vc->state.y;
1986 	else if (!nr)
1987 		nr = 1;
1988 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
1989 	vc->vc_need_wrap = 0;
1990 }
1991 
1992 /* console_lock is held */
1993 static void csi_P(struct vc_data *vc, unsigned int nr)
1994 {
1995 	if (nr > vc->vc_cols - vc->state.x)
1996 		nr = vc->vc_cols - vc->state.x;
1997 	else if (!nr)
1998 		nr = 1;
1999 	delete_char(vc, nr);
2000 }
2001 
2002 /* console_lock is held */
2003 static void csi_M(struct vc_data *vc, unsigned int nr)
2004 {
2005 	if (nr > vc->vc_rows - vc->state.y)
2006 		nr = vc->vc_rows - vc->state.y;
2007 	else if (!nr)
2008 		nr=1;
2009 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
2010 	vc->vc_need_wrap = 0;
2011 }
2012 
2013 /* console_lock is held (except via vc_init->reset_terminal */
2014 static void save_cur(struct vc_data *vc)
2015 {
2016 	memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
2017 }
2018 
2019 /* console_lock is held */
2020 static void restore_cur(struct vc_data *vc)
2021 {
2022 	memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
2023 
2024 	gotoxy(vc, vc->state.x, vc->state.y);
2025 	vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
2026 			vc);
2027 	update_attr(vc);
2028 	vc->vc_need_wrap = 0;
2029 }
2030 
2031 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2032 	EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2033 	ESpalette, ESosc, ESapc, ESpm, ESdcs };
2034 
2035 /* console_lock is held (except via vc_init()) */
2036 static void reset_terminal(struct vc_data *vc, int do_clear)
2037 {
2038 	unsigned int i;
2039 
2040 	vc->vc_top		= 0;
2041 	vc->vc_bottom		= vc->vc_rows;
2042 	vc->vc_state		= ESnormal;
2043 	vc->vc_priv		= EPecma;
2044 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
2045 	vc->state.Gx_charset[0]	= LAT1_MAP;
2046 	vc->state.Gx_charset[1]	= GRAF_MAP;
2047 	vc->state.charset	= 0;
2048 	vc->vc_need_wrap	= 0;
2049 	vc->vc_report_mouse	= 0;
2050 	vc->vc_utf              = default_utf8;
2051 	vc->vc_utf_count	= 0;
2052 
2053 	vc->vc_disp_ctrl	= 0;
2054 	vc->vc_toggle_meta	= 0;
2055 
2056 	vc->vc_decscnm		= 0;
2057 	vc->vc_decom		= 0;
2058 	vc->vc_decawm		= 1;
2059 	vc->vc_deccm		= global_cursor_default;
2060 	vc->vc_decim		= 0;
2061 
2062 	vt_reset_keyboard(vc->vc_num);
2063 
2064 	vc->vc_cursor_type = cur_default;
2065 	vc->vc_complement_mask = vc->vc_s_complement_mask;
2066 
2067 	default_attr(vc);
2068 	update_attr(vc);
2069 
2070 	bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2071 	for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
2072 		set_bit(i, vc->vc_tab_stop);
2073 
2074 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2075 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2076 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2077 
2078 	gotoxy(vc, 0, 0);
2079 	save_cur(vc);
2080 	if (do_clear)
2081 	    csi_J(vc, 2);
2082 }
2083 
2084 static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
2085 {
2086 	unsigned char *charset = &vc->state.Gx_charset[which];
2087 
2088 	switch (c) {
2089 	case '0':
2090 		*charset = GRAF_MAP;
2091 		break;
2092 	case 'B':
2093 		*charset = LAT1_MAP;
2094 		break;
2095 	case 'U':
2096 		*charset = IBMPC_MAP;
2097 		break;
2098 	case 'K':
2099 		*charset = USER_MAP;
2100 		break;
2101 	}
2102 
2103 	if (vc->state.charset == which)
2104 		vc->vc_translate = set_translate(*charset, vc);
2105 }
2106 
2107 /* is this state an ANSI control string? */
2108 static bool ansi_control_string(unsigned int state)
2109 {
2110 	if (state == ESosc || state == ESapc || state == ESpm || state == ESdcs)
2111 		return true;
2112 	return false;
2113 }
2114 
2115 /* console_lock is held */
2116 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2117 {
2118 	/*
2119 	 *  Control characters can be used in the _middle_
2120 	 *  of an escape sequence, aside from ANSI control strings.
2121 	 */
2122 	if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
2123 		return;
2124 	switch (c) {
2125 	case 0:
2126 		return;
2127 	case 7:
2128 		if (ansi_control_string(vc->vc_state))
2129 			vc->vc_state = ESnormal;
2130 		else if (vc->vc_bell_duration)
2131 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2132 		return;
2133 	case 8:
2134 		bs(vc);
2135 		return;
2136 	case 9:
2137 		vc->vc_pos -= (vc->state.x << 1);
2138 
2139 		vc->state.x = find_next_bit(vc->vc_tab_stop,
2140 				min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2141 				vc->state.x + 1);
2142 		if (vc->state.x >= VC_TABSTOPS_COUNT)
2143 			vc->state.x = vc->vc_cols - 1;
2144 
2145 		vc->vc_pos += (vc->state.x << 1);
2146 		notify_write(vc, '\t');
2147 		return;
2148 	case 10: case 11: case 12:
2149 		lf(vc);
2150 		if (!is_kbd(vc, lnm))
2151 			return;
2152 		fallthrough;
2153 	case 13:
2154 		cr(vc);
2155 		return;
2156 	case 14:
2157 		vc->state.charset = 1;
2158 		vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2159 		vc->vc_disp_ctrl = 1;
2160 		return;
2161 	case 15:
2162 		vc->state.charset = 0;
2163 		vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2164 		vc->vc_disp_ctrl = 0;
2165 		return;
2166 	case 24: case 26:
2167 		vc->vc_state = ESnormal;
2168 		return;
2169 	case 27:
2170 		vc->vc_state = ESesc;
2171 		return;
2172 	case 127:
2173 		del(vc);
2174 		return;
2175 	case 128+27:
2176 		vc->vc_state = ESsquare;
2177 		return;
2178 	}
2179 	switch(vc->vc_state) {
2180 	case ESesc:
2181 		vc->vc_state = ESnormal;
2182 		switch (c) {
2183 		case '[':
2184 			vc->vc_state = ESsquare;
2185 			return;
2186 		case ']':
2187 			vc->vc_state = ESnonstd;
2188 			return;
2189 		case '_':
2190 			vc->vc_state = ESapc;
2191 			return;
2192 		case '^':
2193 			vc->vc_state = ESpm;
2194 			return;
2195 		case '%':
2196 			vc->vc_state = ESpercent;
2197 			return;
2198 		case 'E':
2199 			cr(vc);
2200 			lf(vc);
2201 			return;
2202 		case 'M':
2203 			ri(vc);
2204 			return;
2205 		case 'D':
2206 			lf(vc);
2207 			return;
2208 		case 'H':
2209 			if (vc->state.x < VC_TABSTOPS_COUNT)
2210 				set_bit(vc->state.x, vc->vc_tab_stop);
2211 			return;
2212 		case 'P':
2213 			vc->vc_state = ESdcs;
2214 			return;
2215 		case 'Z':
2216 			respond_ID(tty);
2217 			return;
2218 		case '7':
2219 			save_cur(vc);
2220 			return;
2221 		case '8':
2222 			restore_cur(vc);
2223 			return;
2224 		case '(':
2225 			vc->vc_state = ESsetG0;
2226 			return;
2227 		case ')':
2228 			vc->vc_state = ESsetG1;
2229 			return;
2230 		case '#':
2231 			vc->vc_state = EShash;
2232 			return;
2233 		case 'c':
2234 			reset_terminal(vc, 1);
2235 			return;
2236 		case '>':  /* Numeric keypad */
2237 			clr_kbd(vc, kbdapplic);
2238 			return;
2239 		case '=':  /* Appl. keypad */
2240 			set_kbd(vc, kbdapplic);
2241 			return;
2242 		}
2243 		return;
2244 	case ESnonstd:
2245 		if (c=='P') {   /* palette escape sequence */
2246 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2247 				vc->vc_par[vc->vc_npar] = 0;
2248 			vc->vc_npar = 0;
2249 			vc->vc_state = ESpalette;
2250 			return;
2251 		} else if (c=='R') {   /* reset palette */
2252 			reset_palette(vc);
2253 			vc->vc_state = ESnormal;
2254 		} else if (c>='0' && c<='9')
2255 			vc->vc_state = ESosc;
2256 		else
2257 			vc->vc_state = ESnormal;
2258 		return;
2259 	case ESpalette:
2260 		if (isxdigit(c)) {
2261 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2262 			if (vc->vc_npar == 7) {
2263 				int i = vc->vc_par[0] * 3, j = 1;
2264 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2265 				vc->vc_palette[i++] += vc->vc_par[j++];
2266 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2267 				vc->vc_palette[i++] += vc->vc_par[j++];
2268 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2269 				vc->vc_palette[i] += vc->vc_par[j];
2270 				set_palette(vc);
2271 				vc->vc_state = ESnormal;
2272 			}
2273 		} else
2274 			vc->vc_state = ESnormal;
2275 		return;
2276 	case ESsquare:
2277 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2278 			vc->vc_par[vc->vc_npar] = 0;
2279 		vc->vc_npar = 0;
2280 		vc->vc_state = ESgetpars;
2281 		if (c == '[') { /* Function key */
2282 			vc->vc_state=ESfunckey;
2283 			return;
2284 		}
2285 		switch (c) {
2286 		case '?':
2287 			vc->vc_priv = EPdec;
2288 			return;
2289 		case '>':
2290 			vc->vc_priv = EPgt;
2291 			return;
2292 		case '=':
2293 			vc->vc_priv = EPeq;
2294 			return;
2295 		case '<':
2296 			vc->vc_priv = EPlt;
2297 			return;
2298 		}
2299 		vc->vc_priv = EPecma;
2300 		fallthrough;
2301 	case ESgetpars:
2302 		if (c == ';' && vc->vc_npar < NPAR - 1) {
2303 			vc->vc_npar++;
2304 			return;
2305 		} else if (c>='0' && c<='9') {
2306 			vc->vc_par[vc->vc_npar] *= 10;
2307 			vc->vc_par[vc->vc_npar] += c - '0';
2308 			return;
2309 		}
2310 		if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2311 			vc->vc_state = EScsiignore;
2312 			return;
2313 		}
2314 		vc->vc_state = ESnormal;
2315 		switch(c) {
2316 		case 'h':
2317 			if (vc->vc_priv <= EPdec)
2318 				set_mode(vc, 1);
2319 			return;
2320 		case 'l':
2321 			if (vc->vc_priv <= EPdec)
2322 				set_mode(vc, 0);
2323 			return;
2324 		case 'c':
2325 			if (vc->vc_priv == EPdec) {
2326 				if (vc->vc_par[0])
2327 					vc->vc_cursor_type =
2328 						CUR_MAKE(vc->vc_par[0],
2329 							 vc->vc_par[1],
2330 							 vc->vc_par[2]);
2331 				else
2332 					vc->vc_cursor_type = cur_default;
2333 				return;
2334 			}
2335 			break;
2336 		case 'm':
2337 			if (vc->vc_priv == EPdec) {
2338 				clear_selection();
2339 				if (vc->vc_par[0])
2340 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2341 				else
2342 					vc->vc_complement_mask = vc->vc_s_complement_mask;
2343 				return;
2344 			}
2345 			break;
2346 		case 'n':
2347 			if (vc->vc_priv == EPecma) {
2348 				if (vc->vc_par[0] == 5)
2349 					status_report(tty);
2350 				else if (vc->vc_par[0] == 6)
2351 					cursor_report(vc, tty);
2352 			}
2353 			return;
2354 		}
2355 		if (vc->vc_priv != EPecma) {
2356 			vc->vc_priv = EPecma;
2357 			return;
2358 		}
2359 		switch(c) {
2360 		case 'G': case '`':
2361 			if (vc->vc_par[0])
2362 				vc->vc_par[0]--;
2363 			gotoxy(vc, vc->vc_par[0], vc->state.y);
2364 			return;
2365 		case 'A':
2366 			if (!vc->vc_par[0])
2367 				vc->vc_par[0]++;
2368 			gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2369 			return;
2370 		case 'B': case 'e':
2371 			if (!vc->vc_par[0])
2372 				vc->vc_par[0]++;
2373 			gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2374 			return;
2375 		case 'C': case 'a':
2376 			if (!vc->vc_par[0])
2377 				vc->vc_par[0]++;
2378 			gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2379 			return;
2380 		case 'D':
2381 			if (!vc->vc_par[0])
2382 				vc->vc_par[0]++;
2383 			gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2384 			return;
2385 		case 'E':
2386 			if (!vc->vc_par[0])
2387 				vc->vc_par[0]++;
2388 			gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2389 			return;
2390 		case 'F':
2391 			if (!vc->vc_par[0])
2392 				vc->vc_par[0]++;
2393 			gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2394 			return;
2395 		case 'd':
2396 			if (vc->vc_par[0])
2397 				vc->vc_par[0]--;
2398 			gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2399 			return;
2400 		case 'H': case 'f':
2401 			if (vc->vc_par[0])
2402 				vc->vc_par[0]--;
2403 			if (vc->vc_par[1])
2404 				vc->vc_par[1]--;
2405 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2406 			return;
2407 		case 'J':
2408 			csi_J(vc, vc->vc_par[0]);
2409 			return;
2410 		case 'K':
2411 			csi_K(vc, vc->vc_par[0]);
2412 			return;
2413 		case 'L':
2414 			csi_L(vc, vc->vc_par[0]);
2415 			return;
2416 		case 'M':
2417 			csi_M(vc, vc->vc_par[0]);
2418 			return;
2419 		case 'P':
2420 			csi_P(vc, vc->vc_par[0]);
2421 			return;
2422 		case 'c':
2423 			if (!vc->vc_par[0])
2424 				respond_ID(tty);
2425 			return;
2426 		case 'g':
2427 			if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2428 				set_bit(vc->state.x, vc->vc_tab_stop);
2429 			else if (vc->vc_par[0] == 3)
2430 				bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2431 			return;
2432 		case 'm':
2433 			csi_m(vc);
2434 			return;
2435 		case 'q': /* DECLL - but only 3 leds */
2436 			/* map 0,1,2,3 to 0,1,2,4 */
2437 			if (vc->vc_par[0] < 4)
2438 				vt_set_led_state(vc->vc_num,
2439 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2440 			return;
2441 		case 'r':
2442 			if (!vc->vc_par[0])
2443 				vc->vc_par[0]++;
2444 			if (!vc->vc_par[1])
2445 				vc->vc_par[1] = vc->vc_rows;
2446 			/* Minimum allowed region is 2 lines */
2447 			if (vc->vc_par[0] < vc->vc_par[1] &&
2448 			    vc->vc_par[1] <= vc->vc_rows) {
2449 				vc->vc_top = vc->vc_par[0] - 1;
2450 				vc->vc_bottom = vc->vc_par[1];
2451 				gotoxay(vc, 0, 0);
2452 			}
2453 			return;
2454 		case 's':
2455 			save_cur(vc);
2456 			return;
2457 		case 'u':
2458 			restore_cur(vc);
2459 			return;
2460 		case 'X':
2461 			csi_X(vc, vc->vc_par[0]);
2462 			return;
2463 		case '@':
2464 			csi_at(vc, vc->vc_par[0]);
2465 			return;
2466 		case ']': /* setterm functions */
2467 			setterm_command(vc);
2468 			return;
2469 		}
2470 		return;
2471 	case EScsiignore:
2472 		if (c >= 0x20 && c <= 0x3f)
2473 			return;
2474 		vc->vc_state = ESnormal;
2475 		return;
2476 	case ESpercent:
2477 		vc->vc_state = ESnormal;
2478 		switch (c) {
2479 		case '@':  /* defined in ISO 2022 */
2480 			vc->vc_utf = 0;
2481 			return;
2482 		case 'G':  /* prelim official escape code */
2483 		case '8':  /* retained for compatibility */
2484 			vc->vc_utf = 1;
2485 			return;
2486 		}
2487 		return;
2488 	case ESfunckey:
2489 		vc->vc_state = ESnormal;
2490 		return;
2491 	case EShash:
2492 		vc->vc_state = ESnormal;
2493 		if (c == '8') {
2494 			/* DEC screen alignment test. kludge :-) */
2495 			vc->vc_video_erase_char =
2496 				(vc->vc_video_erase_char & 0xff00) | 'E';
2497 			csi_J(vc, 2);
2498 			vc->vc_video_erase_char =
2499 				(vc->vc_video_erase_char & 0xff00) | ' ';
2500 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2501 		}
2502 		return;
2503 	case ESsetG0:
2504 		vc_setGx(vc, 0, c);
2505 		vc->vc_state = ESnormal;
2506 		return;
2507 	case ESsetG1:
2508 		vc_setGx(vc, 1, c);
2509 		vc->vc_state = ESnormal;
2510 		return;
2511 	case ESapc:
2512 		return;
2513 	case ESosc:
2514 		return;
2515 	case ESpm:
2516 		return;
2517 	case ESdcs:
2518 		return;
2519 	default:
2520 		vc->vc_state = ESnormal;
2521 	}
2522 }
2523 
2524 /* is_double_width() is based on the wcwidth() implementation by
2525  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2526  * Latest version: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2527  */
2528 struct interval {
2529 	uint32_t first;
2530 	uint32_t last;
2531 };
2532 
2533 static int ucs_cmp(const void *key, const void *elt)
2534 {
2535 	uint32_t ucs = *(uint32_t *)key;
2536 	struct interval e = *(struct interval *) elt;
2537 
2538 	if (ucs > e.last)
2539 		return 1;
2540 	else if (ucs < e.first)
2541 		return -1;
2542 	return 0;
2543 }
2544 
2545 static int is_double_width(uint32_t ucs)
2546 {
2547 	static const struct interval double_width[] = {
2548 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2549 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2550 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2551 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2552 	};
2553 	if (ucs < double_width[0].first ||
2554 	    ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2555 		return 0;
2556 
2557 	return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2558 			sizeof(struct interval), ucs_cmp) != NULL;
2559 }
2560 
2561 struct vc_draw_region {
2562 	unsigned long from, to;
2563 	int x;
2564 };
2565 
2566 static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
2567 {
2568 	if (draw->x < 0)
2569 		return;
2570 
2571 	vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
2572 			(u16 *)draw->to - (u16 *)draw->from, vc->state.y,
2573 			draw->x);
2574 	draw->x = -1;
2575 }
2576 
2577 static inline int vc_translate_ascii(const struct vc_data *vc, int c)
2578 {
2579 	if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
2580 		if (vc->vc_toggle_meta)
2581 			c |= 0x80;
2582 
2583 		return vc->vc_translate[c];
2584 	}
2585 
2586 	return c;
2587 }
2588 
2589 
2590 /**
2591  * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
2592  * @c: the received character, or U+FFFD for invalid sequences.
2593  */
2594 static inline int vc_sanitize_unicode(const int c)
2595 {
2596 	if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2597 		return 0xfffd;
2598 
2599 	return c;
2600 }
2601 
2602 /**
2603  * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
2604  * @vc: virtual console
2605  * @c: character to translate
2606  * @rescan: we return true if we need more (continuation) data
2607  *
2608  * @vc_utf_char is the being-constructed unicode character.
2609  * @vc_utf_count is the number of continuation bytes still expected to arrive.
2610  * @vc_npar is the number of continuation bytes arrived so far.
2611  */
2612 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
2613 {
2614 	static const u32 utf8_length_changes[] = {
2615 		0x0000007f, 0x000007ff, 0x0000ffff,
2616 		0x001fffff, 0x03ffffff, 0x7fffffff
2617 	};
2618 
2619 	/* Continuation byte received */
2620 	if ((c & 0xc0) == 0x80) {
2621 		/* Unexpected continuation byte? */
2622 		if (!vc->vc_utf_count)
2623 			return 0xfffd;
2624 
2625 		vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2626 		vc->vc_npar++;
2627 		if (--vc->vc_utf_count)
2628 			goto need_more_bytes;
2629 
2630 		/* Got a whole character */
2631 		c = vc->vc_utf_char;
2632 		/* Reject overlong sequences */
2633 		if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2634 				c > utf8_length_changes[vc->vc_npar])
2635 			return 0xfffd;
2636 
2637 		return vc_sanitize_unicode(c);
2638 	}
2639 
2640 	/* Single ASCII byte or first byte of a sequence received */
2641 	if (vc->vc_utf_count) {
2642 		/* Continuation byte expected */
2643 		*rescan = true;
2644 		vc->vc_utf_count = 0;
2645 		return 0xfffd;
2646 	}
2647 
2648 	/* Nothing to do if an ASCII byte was received */
2649 	if (c <= 0x7f)
2650 		return c;
2651 
2652 	/* First byte of a multibyte sequence received */
2653 	vc->vc_npar = 0;
2654 	if ((c & 0xe0) == 0xc0) {
2655 		vc->vc_utf_count = 1;
2656 		vc->vc_utf_char = (c & 0x1f);
2657 	} else if ((c & 0xf0) == 0xe0) {
2658 		vc->vc_utf_count = 2;
2659 		vc->vc_utf_char = (c & 0x0f);
2660 	} else if ((c & 0xf8) == 0xf0) {
2661 		vc->vc_utf_count = 3;
2662 		vc->vc_utf_char = (c & 0x07);
2663 	} else if ((c & 0xfc) == 0xf8) {
2664 		vc->vc_utf_count = 4;
2665 		vc->vc_utf_char = (c & 0x03);
2666 	} else if ((c & 0xfe) == 0xfc) {
2667 		vc->vc_utf_count = 5;
2668 		vc->vc_utf_char = (c & 0x01);
2669 	} else {
2670 		/* 254 and 255 are invalid */
2671 		return 0xfffd;
2672 	}
2673 
2674 need_more_bytes:
2675 	return -1;
2676 }
2677 
2678 static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
2679 {
2680 	/* Do no translation at all in control states */
2681 	if (vc->vc_state != ESnormal)
2682 		return *c;
2683 
2684 	if (vc->vc_utf && !vc->vc_disp_ctrl)
2685 		return *c = vc_translate_unicode(vc, *c, rescan);
2686 
2687 	/* no utf or alternate charset mode */
2688 	return vc_translate_ascii(vc, *c);
2689 }
2690 
2691 static inline unsigned char vc_invert_attr(const struct vc_data *vc)
2692 {
2693 	if (!vc->vc_can_do_color)
2694 		return vc->vc_attr ^ 0x08;
2695 
2696 	if (vc->vc_hi_font_mask == 0x100)
2697 		return   (vc->vc_attr & 0x11) |
2698 			((vc->vc_attr & 0xe0) >> 4) |
2699 			((vc->vc_attr & 0x0e) << 4);
2700 
2701 	return   (vc->vc_attr & 0x88) |
2702 		((vc->vc_attr & 0x70) >> 4) |
2703 		((vc->vc_attr & 0x07) << 4);
2704 }
2705 
2706 static bool vc_is_control(struct vc_data *vc, int tc, int c)
2707 {
2708 	/*
2709 	 * A bitmap for codes <32. A bit of 1 indicates that the code
2710 	 * corresponding to that bit number invokes some special action (such
2711 	 * as cursor movement) and should not be displayed as a glyph unless
2712 	 * the disp_ctrl mode is explicitly enabled.
2713 	 */
2714 	static const u32 CTRL_ACTION = 0x0d00ff81;
2715 	/* Cannot be overridden by disp_ctrl */
2716 	static const u32 CTRL_ALWAYS = 0x0800f501;
2717 
2718 	if (vc->vc_state != ESnormal)
2719 		return true;
2720 
2721 	if (!tc)
2722 		return true;
2723 
2724 	/*
2725 	 * If the original code was a control character we only allow a glyph
2726 	 * to be displayed if the code is not normally used (such as for cursor
2727 	 * movement) or if the disp_ctrl mode has been explicitly enabled.
2728 	 * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
2729 	 * displayed as control characters, as the console would be pretty
2730 	 * useless without them; to display an arbitrary font position use the
2731 	 * direct-to-font zone in UTF-8 mode.
2732 	 */
2733 	if (c < 32) {
2734 		if (vc->vc_disp_ctrl)
2735 			return CTRL_ALWAYS & BIT(c);
2736 		else
2737 			return vc->vc_utf || (CTRL_ACTION & BIT(c));
2738 	}
2739 
2740 	if (c == 127 && !vc->vc_disp_ctrl)
2741 		return true;
2742 
2743 	if (c == 128 + 27)
2744 		return true;
2745 
2746 	return false;
2747 }
2748 
2749 static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
2750 		struct vc_draw_region *draw)
2751 {
2752 	int next_c;
2753 	unsigned char vc_attr = vc->vc_attr;
2754 	u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
2755 	u8 width = 1;
2756 	bool inverse = false;
2757 
2758 	if (vc->vc_utf && !vc->vc_disp_ctrl) {
2759 		if (is_double_width(c))
2760 			width = 2;
2761 	}
2762 
2763 	/* Now try to find out how to display it */
2764 	tc = conv_uni_to_pc(vc, tc);
2765 	if (tc & ~charmask) {
2766 		if (tc == -1 || tc == -2)
2767 			return -1; /* nothing to display */
2768 
2769 		/* Glyph not found */
2770 		if ((!vc->vc_utf || vc->vc_disp_ctrl || c < 128) &&
2771 				!(c & ~charmask)) {
2772 			/*
2773 			 * In legacy mode use the glyph we get by a 1:1
2774 			 * mapping.
2775 			 * This would make absolutely no sense with Unicode in
2776 			 * mind, but do this for ASCII characters since a font
2777 			 * may lack Unicode mapping info and we don't want to
2778 			 * end up with having question marks only.
2779 			 */
2780 			tc = c;
2781 		} else {
2782 			/*
2783 			 * Display U+FFFD. If it's not found, display an inverse
2784 			 * question mark.
2785 			 */
2786 			tc = conv_uni_to_pc(vc, 0xfffd);
2787 			if (tc < 0) {
2788 				inverse = true;
2789 				tc = conv_uni_to_pc(vc, '?');
2790 				if (tc < 0)
2791 					tc = '?';
2792 
2793 				vc_attr = vc_invert_attr(vc);
2794 				con_flush(vc, draw);
2795 			}
2796 		}
2797 	}
2798 
2799 	next_c = c;
2800 	while (1) {
2801 		if (vc->vc_need_wrap || vc->vc_decim)
2802 			con_flush(vc, draw);
2803 		if (vc->vc_need_wrap) {
2804 			cr(vc);
2805 			lf(vc);
2806 		}
2807 		if (vc->vc_decim)
2808 			insert_char(vc, 1);
2809 		vc_uniscr_putc(vc, next_c);
2810 
2811 		if (himask)
2812 			tc = ((tc & 0x100) ? himask : 0) |
2813 			      (tc &  0xff);
2814 		tc |= (vc_attr << 8) & ~himask;
2815 
2816 		scr_writew(tc, (u16 *)vc->vc_pos);
2817 
2818 		if (con_should_update(vc) && draw->x < 0) {
2819 			draw->x = vc->state.x;
2820 			draw->from = vc->vc_pos;
2821 		}
2822 		if (vc->state.x == vc->vc_cols - 1) {
2823 			vc->vc_need_wrap = vc->vc_decawm;
2824 			draw->to = vc->vc_pos + 2;
2825 		} else {
2826 			vc->state.x++;
2827 			draw->to = (vc->vc_pos += 2);
2828 		}
2829 
2830 		if (!--width)
2831 			break;
2832 
2833 		/* A space is printed in the second column */
2834 		tc = conv_uni_to_pc(vc, ' ');
2835 		if (tc < 0)
2836 			tc = ' ';
2837 		next_c = ' ';
2838 	}
2839 	notify_write(vc, c);
2840 
2841 	if (inverse)
2842 		con_flush(vc, draw);
2843 
2844 	return 0;
2845 }
2846 
2847 /* acquires console_lock */
2848 static int do_con_write(struct tty_struct *tty, const u8 *buf, int count)
2849 {
2850 	struct vc_draw_region draw = {
2851 		.x = -1,
2852 	};
2853 	int c, tc, n = 0;
2854 	unsigned int currcons;
2855 	struct vc_data *vc;
2856 	struct vt_notifier_param param;
2857 	bool rescan;
2858 
2859 	if (in_interrupt())
2860 		return count;
2861 
2862 	console_lock();
2863 	vc = tty->driver_data;
2864 	if (vc == NULL) {
2865 		pr_err("vt: argh, driver_data is NULL !\n");
2866 		console_unlock();
2867 		return 0;
2868 	}
2869 
2870 	currcons = vc->vc_num;
2871 	if (!vc_cons_allocated(currcons)) {
2872 		/* could this happen? */
2873 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2874 		console_unlock();
2875 		return 0;
2876 	}
2877 
2878 
2879 	/* undraw cursor first */
2880 	if (con_is_fg(vc))
2881 		hide_cursor(vc);
2882 
2883 	param.vc = vc;
2884 
2885 	while (!tty->flow.stopped && count) {
2886 		int orig = *buf;
2887 		buf++;
2888 		n++;
2889 		count--;
2890 rescan_last_byte:
2891 		c = orig;
2892 		rescan = false;
2893 
2894 		tc = vc_translate(vc, &c, &rescan);
2895 		if (tc == -1)
2896 			continue;
2897 
2898 		param.c = tc;
2899 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2900 					&param) == NOTIFY_STOP)
2901 			continue;
2902 
2903 		if (vc_is_control(vc, tc, c)) {
2904 			con_flush(vc, &draw);
2905 			do_con_trol(tty, vc, orig);
2906 			continue;
2907 		}
2908 
2909 		if (vc_con_write_normal(vc, tc, c, &draw) < 0)
2910 			continue;
2911 
2912 		if (rescan)
2913 			goto rescan_last_byte;
2914 	}
2915 	con_flush(vc, &draw);
2916 	console_conditional_schedule();
2917 	notify_update(vc);
2918 	console_unlock();
2919 	return n;
2920 }
2921 
2922 /*
2923  * This is the console switching callback.
2924  *
2925  * Doing console switching in a process context allows
2926  * us to do the switches asynchronously (needed when we want
2927  * to switch due to a keyboard interrupt).  Synchronization
2928  * with other console code and prevention of re-entrancy is
2929  * ensured with console_lock.
2930  */
2931 static void console_callback(struct work_struct *ignored)
2932 {
2933 	console_lock();
2934 
2935 	if (want_console >= 0) {
2936 		if (want_console != fg_console &&
2937 		    vc_cons_allocated(want_console)) {
2938 			hide_cursor(vc_cons[fg_console].d);
2939 			change_console(vc_cons[want_console].d);
2940 			/* we only changed when the console had already
2941 			   been allocated - a new console is not created
2942 			   in an interrupt routine */
2943 		}
2944 		want_console = -1;
2945 	}
2946 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2947 		do_poke_blanked_console = 0;
2948 		poke_blanked_console();
2949 	}
2950 	if (scrollback_delta) {
2951 		struct vc_data *vc = vc_cons[fg_console].d;
2952 		clear_selection();
2953 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2954 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2955 		scrollback_delta = 0;
2956 	}
2957 	if (blank_timer_expired) {
2958 		do_blank_screen(0);
2959 		blank_timer_expired = 0;
2960 	}
2961 	notify_update(vc_cons[fg_console].d);
2962 
2963 	console_unlock();
2964 }
2965 
2966 int set_console(int nr)
2967 {
2968 	struct vc_data *vc = vc_cons[fg_console].d;
2969 
2970 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
2971 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2972 
2973 		/*
2974 		 * Console switch will fail in console_callback() or
2975 		 * change_console() so there is no point scheduling
2976 		 * the callback
2977 		 *
2978 		 * Existing set_console() users don't check the return
2979 		 * value so this shouldn't break anything
2980 		 */
2981 		return -EINVAL;
2982 	}
2983 
2984 	want_console = nr;
2985 	schedule_console_callback();
2986 
2987 	return 0;
2988 }
2989 
2990 struct tty_driver *console_driver;
2991 
2992 #ifdef CONFIG_VT_CONSOLE
2993 
2994 /**
2995  * vt_kmsg_redirect() - Sets/gets the kernel message console
2996  * @new:	The new virtual terminal number or -1 if the console should stay
2997  * 		unchanged
2998  *
2999  * By default, the kernel messages are always printed on the current virtual
3000  * console. However, the user may modify that default with the
3001  * TIOCL_SETKMSGREDIRECT ioctl call.
3002  *
3003  * This function sets the kernel message console to be @new. It returns the old
3004  * virtual console number. The virtual terminal number 0 (both as parameter and
3005  * return value) means no redirection (i.e. always printed on the currently
3006  * active console).
3007  *
3008  * The parameter -1 means that only the current console is returned, but the
3009  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
3010  * case to make the code more understandable.
3011  *
3012  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
3013  * the parameter and always returns 0.
3014  */
3015 int vt_kmsg_redirect(int new)
3016 {
3017 	static int kmsg_con;
3018 
3019 	if (new != -1)
3020 		return xchg(&kmsg_con, new);
3021 	else
3022 		return kmsg_con;
3023 }
3024 
3025 /*
3026  *	Console on virtual terminal
3027  *
3028  * The console must be locked when we get here.
3029  */
3030 
3031 static void vt_console_print(struct console *co, const char *b, unsigned count)
3032 {
3033 	struct vc_data *vc = vc_cons[fg_console].d;
3034 	unsigned char c;
3035 	static DEFINE_SPINLOCK(printing_lock);
3036 	const ushort *start;
3037 	ushort start_x, cnt;
3038 	int kmsg_console;
3039 
3040 	WARN_CONSOLE_UNLOCKED();
3041 
3042 	/* this protects against concurrent oops only */
3043 	if (!spin_trylock(&printing_lock))
3044 		return;
3045 
3046 	kmsg_console = vt_get_kmsg_redirect();
3047 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
3048 		vc = vc_cons[kmsg_console - 1].d;
3049 
3050 	if (!vc_cons_allocated(fg_console)) {
3051 		/* impossible */
3052 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
3053 		goto quit;
3054 	}
3055 
3056 	if (vc->vc_mode != KD_TEXT)
3057 		goto quit;
3058 
3059 	/* undraw cursor first */
3060 	if (con_is_fg(vc))
3061 		hide_cursor(vc);
3062 
3063 	start = (ushort *)vc->vc_pos;
3064 	start_x = vc->state.x;
3065 	cnt = 0;
3066 	while (count--) {
3067 		c = *b++;
3068 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
3069 			if (cnt && con_is_visible(vc))
3070 				vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3071 			cnt = 0;
3072 			if (c == 8) {		/* backspace */
3073 				bs(vc);
3074 				start = (ushort *)vc->vc_pos;
3075 				start_x = vc->state.x;
3076 				continue;
3077 			}
3078 			if (c != 13)
3079 				lf(vc);
3080 			cr(vc);
3081 			start = (ushort *)vc->vc_pos;
3082 			start_x = vc->state.x;
3083 			if (c == 10 || c == 13)
3084 				continue;
3085 		}
3086 		vc_uniscr_putc(vc, c);
3087 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3088 		notify_write(vc, c);
3089 		cnt++;
3090 		if (vc->state.x == vc->vc_cols - 1) {
3091 			vc->vc_need_wrap = 1;
3092 		} else {
3093 			vc->vc_pos += 2;
3094 			vc->state.x++;
3095 		}
3096 	}
3097 	if (cnt && con_is_visible(vc))
3098 		vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3099 	set_cursor(vc);
3100 	notify_update(vc);
3101 
3102 quit:
3103 	spin_unlock(&printing_lock);
3104 }
3105 
3106 static struct tty_driver *vt_console_device(struct console *c, int *index)
3107 {
3108 	*index = c->index ? c->index-1 : fg_console;
3109 	return console_driver;
3110 }
3111 
3112 static int vt_console_setup(struct console *co, char *options)
3113 {
3114 	return co->index >= MAX_NR_CONSOLES ? -EINVAL : 0;
3115 }
3116 
3117 static struct console vt_console_driver = {
3118 	.name		= "tty",
3119 	.setup		= vt_console_setup,
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 	case TIOCL_SETSEL:
3158 		return set_selection_user((struct tiocl_selection
3159 					 __user *)(p+1), tty);
3160 	case TIOCL_PASTESEL:
3161 		return paste_selection(tty);
3162 	case TIOCL_UNBLANKSCREEN:
3163 		console_lock();
3164 		unblank_screen();
3165 		console_unlock();
3166 		break;
3167 	case TIOCL_SELLOADLUT:
3168 		console_lock();
3169 		ret = sel_loadlut(p);
3170 		console_unlock();
3171 		break;
3172 	case TIOCL_GETSHIFTSTATE:
3173 		/*
3174 		 * Make it possible to react to Shift+Mousebutton. Note that
3175 		 * 'shift_state' is an undocumented kernel-internal variable;
3176 		 * programs not closely related to the kernel should not use
3177 		 * this.
3178 		 */
3179 		data = vt_get_shift_state();
3180 		return put_user(data, p);
3181 	case TIOCL_GETMOUSEREPORTING:
3182 		console_lock();	/* May be overkill */
3183 		data = mouse_reporting();
3184 		console_unlock();
3185 		return put_user(data, p);
3186 	case TIOCL_SETVESABLANK:
3187 		console_lock();
3188 		ret = set_vesa_blanking(p);
3189 		console_unlock();
3190 		break;
3191 	case TIOCL_GETKMSGREDIRECT:
3192 		data = vt_get_kmsg_redirect();
3193 		return put_user(data, p);
3194 	case TIOCL_SETKMSGREDIRECT:
3195 		if (!capable(CAP_SYS_ADMIN))
3196 			return -EPERM;
3197 
3198 		if (get_user(data, p+1))
3199 			return -EFAULT;
3200 
3201 		vt_kmsg_redirect(data);
3202 
3203 		break;
3204 	case TIOCL_GETFGCONSOLE:
3205 		/*
3206 		 * No locking needed as this is a transiently correct return
3207 		 * anyway if the caller hasn't disabled switching.
3208 		 */
3209 		return fg_console;
3210 	case TIOCL_SCROLLCONSOLE:
3211 		if (get_user(lines, (s32 __user *)(p+4)))
3212 			return -EFAULT;
3213 
3214 		/*
3215 		 * Needs the console lock here. Note that lots of other calls
3216 		 * need fixing before the lock is actually useful!
3217 		 */
3218 		console_lock();
3219 		scrollfront(vc_cons[fg_console].d, lines);
3220 		console_unlock();
3221 		break;
3222 	case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
3223 		console_lock();
3224 		ignore_poke = 1;
3225 		do_blank_screen(0);
3226 		console_unlock();
3227 		break;
3228 	case TIOCL_BLANKEDSCREEN:
3229 		return console_blanked;
3230 	default:
3231 		return -EINVAL;
3232 	}
3233 
3234 	return ret;
3235 }
3236 
3237 /*
3238  * /dev/ttyN handling
3239  */
3240 
3241 static ssize_t con_write(struct tty_struct *tty, const u8 *buf, size_t count)
3242 {
3243 	int	retval;
3244 
3245 	retval = do_con_write(tty, buf, count);
3246 	con_flush_chars(tty);
3247 
3248 	return retval;
3249 }
3250 
3251 static int con_put_char(struct tty_struct *tty, u8 ch)
3252 {
3253 	return do_con_write(tty, &ch, 1);
3254 }
3255 
3256 static unsigned int con_write_room(struct tty_struct *tty)
3257 {
3258 	if (tty->flow.stopped)
3259 		return 0;
3260 	return 32768;		/* No limit, really; we're not buffering */
3261 }
3262 
3263 /*
3264  * con_throttle and con_unthrottle are only used for
3265  * paste_selection(), which has to stuff in a large number of
3266  * characters...
3267  */
3268 static void con_throttle(struct tty_struct *tty)
3269 {
3270 }
3271 
3272 static void con_unthrottle(struct tty_struct *tty)
3273 {
3274 	struct vc_data *vc = tty->driver_data;
3275 
3276 	wake_up_interruptible(&vc->paste_wait);
3277 }
3278 
3279 /*
3280  * Turn the Scroll-Lock LED on when the tty is stopped
3281  */
3282 static void con_stop(struct tty_struct *tty)
3283 {
3284 	int console_num;
3285 	if (!tty)
3286 		return;
3287 	console_num = tty->index;
3288 	if (!vc_cons_allocated(console_num))
3289 		return;
3290 	vt_kbd_con_stop(console_num);
3291 }
3292 
3293 /*
3294  * Turn the Scroll-Lock LED off when the console is started
3295  */
3296 static void con_start(struct tty_struct *tty)
3297 {
3298 	int console_num;
3299 	if (!tty)
3300 		return;
3301 	console_num = tty->index;
3302 	if (!vc_cons_allocated(console_num))
3303 		return;
3304 	vt_kbd_con_start(console_num);
3305 }
3306 
3307 static void con_flush_chars(struct tty_struct *tty)
3308 {
3309 	struct vc_data *vc;
3310 
3311 	if (in_interrupt())	/* from flush_to_ldisc */
3312 		return;
3313 
3314 	/* if we race with con_close(), vt may be null */
3315 	console_lock();
3316 	vc = tty->driver_data;
3317 	if (vc)
3318 		set_cursor(vc);
3319 	console_unlock();
3320 }
3321 
3322 /*
3323  * Allocate the console screen memory.
3324  */
3325 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3326 {
3327 	unsigned int currcons = tty->index;
3328 	struct vc_data *vc;
3329 	int ret;
3330 
3331 	console_lock();
3332 	ret = vc_allocate(currcons);
3333 	if (ret)
3334 		goto unlock;
3335 
3336 	vc = vc_cons[currcons].d;
3337 
3338 	/* Still being freed */
3339 	if (vc->port.tty) {
3340 		ret = -ERESTARTSYS;
3341 		goto unlock;
3342 	}
3343 
3344 	ret = tty_port_install(&vc->port, driver, tty);
3345 	if (ret)
3346 		goto unlock;
3347 
3348 	tty->driver_data = vc;
3349 	vc->port.tty = tty;
3350 	tty_port_get(&vc->port);
3351 
3352 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3353 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3354 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3355 	}
3356 	if (vc->vc_utf)
3357 		tty->termios.c_iflag |= IUTF8;
3358 	else
3359 		tty->termios.c_iflag &= ~IUTF8;
3360 unlock:
3361 	console_unlock();
3362 	return ret;
3363 }
3364 
3365 static int con_open(struct tty_struct *tty, struct file *filp)
3366 {
3367 	/* everything done in install */
3368 	return 0;
3369 }
3370 
3371 
3372 static void con_close(struct tty_struct *tty, struct file *filp)
3373 {
3374 	/* Nothing to do - we defer to shutdown */
3375 }
3376 
3377 static void con_shutdown(struct tty_struct *tty)
3378 {
3379 	struct vc_data *vc = tty->driver_data;
3380 	BUG_ON(vc == NULL);
3381 	console_lock();
3382 	vc->port.tty = NULL;
3383 	console_unlock();
3384 }
3385 
3386 static void con_cleanup(struct tty_struct *tty)
3387 {
3388 	struct vc_data *vc = tty->driver_data;
3389 
3390 	tty_port_put(&vc->port);
3391 }
3392 
3393 static int default_color           = 7; /* white */
3394 static int default_italic_color    = 2; // green (ASCII)
3395 static int default_underline_color = 3; // cyan (ASCII)
3396 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3397 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3398 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3399 
3400 static void vc_init(struct vc_data *vc, int do_clear)
3401 {
3402 	int j, k ;
3403 
3404 	set_origin(vc);
3405 	vc->vc_pos = vc->vc_origin;
3406 	reset_vc(vc);
3407 	for (j=k=0; j<16; j++) {
3408 		vc->vc_palette[k++] = default_red[j] ;
3409 		vc->vc_palette[k++] = default_grn[j] ;
3410 		vc->vc_palette[k++] = default_blu[j] ;
3411 	}
3412 	vc->vc_def_color       = default_color;
3413 	vc->vc_ulcolor         = default_underline_color;
3414 	vc->vc_itcolor         = default_italic_color;
3415 	vc->vc_halfcolor       = 0x08;   /* grey */
3416 	init_waitqueue_head(&vc->paste_wait);
3417 	reset_terminal(vc, do_clear);
3418 }
3419 
3420 /*
3421  * This routine initializes console interrupts, and does nothing
3422  * else. If you want the screen to clear, call tty_write with
3423  * the appropriate escape-sequence.
3424  */
3425 
3426 static int __init con_init(void)
3427 {
3428 	const char *display_desc = NULL;
3429 	struct vc_data *vc;
3430 	unsigned int currcons = 0, i;
3431 
3432 	console_lock();
3433 
3434 	if (!conswitchp)
3435 		conswitchp = &dummy_con;
3436 	display_desc = conswitchp->con_startup();
3437 	if (!display_desc) {
3438 		fg_console = 0;
3439 		console_unlock();
3440 		return 0;
3441 	}
3442 
3443 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3444 		struct con_driver *con_driver = &registered_con_driver[i];
3445 
3446 		if (con_driver->con == NULL) {
3447 			con_driver->con = conswitchp;
3448 			con_driver->desc = display_desc;
3449 			con_driver->flag = CON_DRIVER_FLAG_INIT;
3450 			con_driver->first = 0;
3451 			con_driver->last = MAX_NR_CONSOLES - 1;
3452 			break;
3453 		}
3454 	}
3455 
3456 	for (i = 0; i < MAX_NR_CONSOLES; i++)
3457 		con_driver_map[i] = conswitchp;
3458 
3459 	if (blankinterval) {
3460 		blank_state = blank_normal_wait;
3461 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3462 	}
3463 
3464 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3465 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3466 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3467 		tty_port_init(&vc->port);
3468 		visual_init(vc, currcons, 1);
3469 		/* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3470 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3471 		vc_init(vc, currcons || !vc->vc_sw->con_save_screen);
3472 	}
3473 	currcons = fg_console = 0;
3474 	master_display_fg = vc = vc_cons[currcons].d;
3475 	set_origin(vc);
3476 	save_screen(vc);
3477 	gotoxy(vc, vc->state.x, vc->state.y);
3478 	csi_J(vc, 0);
3479 	update_screen(vc);
3480 	pr_info("Console: %s %s %dx%d\n",
3481 		vc->vc_can_do_color ? "colour" : "mono",
3482 		display_desc, vc->vc_cols, vc->vc_rows);
3483 
3484 	console_unlock();
3485 
3486 #ifdef CONFIG_VT_CONSOLE
3487 	register_console(&vt_console_driver);
3488 #endif
3489 	return 0;
3490 }
3491 console_initcall(con_init);
3492 
3493 static const struct tty_operations con_ops = {
3494 	.install = con_install,
3495 	.open = con_open,
3496 	.close = con_close,
3497 	.write = con_write,
3498 	.write_room = con_write_room,
3499 	.put_char = con_put_char,
3500 	.flush_chars = con_flush_chars,
3501 	.ioctl = vt_ioctl,
3502 #ifdef CONFIG_COMPAT
3503 	.compat_ioctl = vt_compat_ioctl,
3504 #endif
3505 	.stop = con_stop,
3506 	.start = con_start,
3507 	.throttle = con_throttle,
3508 	.unthrottle = con_unthrottle,
3509 	.resize = vt_resize,
3510 	.shutdown = con_shutdown,
3511 	.cleanup = con_cleanup,
3512 };
3513 
3514 static struct cdev vc0_cdev;
3515 
3516 static ssize_t show_tty_active(struct device *dev,
3517 				struct device_attribute *attr, char *buf)
3518 {
3519 	return sprintf(buf, "tty%d\n", fg_console + 1);
3520 }
3521 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3522 
3523 static struct attribute *vt_dev_attrs[] = {
3524 	&dev_attr_active.attr,
3525 	NULL
3526 };
3527 
3528 ATTRIBUTE_GROUPS(vt_dev);
3529 
3530 int __init vty_init(const struct file_operations *console_fops)
3531 {
3532 	cdev_init(&vc0_cdev, console_fops);
3533 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3534 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3535 		panic("Couldn't register /dev/tty0 driver\n");
3536 	tty0dev = device_create_with_groups(&tty_class, NULL,
3537 					    MKDEV(TTY_MAJOR, 0), NULL,
3538 					    vt_dev_groups, "tty0");
3539 	if (IS_ERR(tty0dev))
3540 		tty0dev = NULL;
3541 
3542 	vcs_init();
3543 
3544 	console_driver = tty_alloc_driver(MAX_NR_CONSOLES, TTY_DRIVER_REAL_RAW |
3545 			TTY_DRIVER_RESET_TERMIOS);
3546 	if (IS_ERR(console_driver))
3547 		panic("Couldn't allocate console driver\n");
3548 
3549 	console_driver->name = "tty";
3550 	console_driver->name_base = 1;
3551 	console_driver->major = TTY_MAJOR;
3552 	console_driver->minor_start = 1;
3553 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3554 	console_driver->init_termios = tty_std_termios;
3555 	if (default_utf8)
3556 		console_driver->init_termios.c_iflag |= IUTF8;
3557 	tty_set_operations(console_driver, &con_ops);
3558 	if (tty_register_driver(console_driver))
3559 		panic("Couldn't register console driver\n");
3560 	kbd_init();
3561 	console_map_init();
3562 #ifdef CONFIG_MDA_CONSOLE
3563 	mda_console_init();
3564 #endif
3565 	return 0;
3566 }
3567 
3568 static struct class *vtconsole_class;
3569 
3570 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3571 			   int deflt)
3572 {
3573 	struct module *owner = csw->owner;
3574 	const char *desc = NULL;
3575 	struct con_driver *con_driver;
3576 	int i, j = -1, k = -1, retval = -ENODEV;
3577 
3578 	if (!try_module_get(owner))
3579 		return -ENODEV;
3580 
3581 	WARN_CONSOLE_UNLOCKED();
3582 
3583 	/* check if driver is registered */
3584 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3585 		con_driver = &registered_con_driver[i];
3586 
3587 		if (con_driver->con == csw) {
3588 			desc = con_driver->desc;
3589 			retval = 0;
3590 			break;
3591 		}
3592 	}
3593 
3594 	if (retval)
3595 		goto err;
3596 
3597 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3598 		csw->con_startup();
3599 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3600 	}
3601 
3602 	if (deflt) {
3603 		if (conswitchp)
3604 			module_put(conswitchp->owner);
3605 
3606 		__module_get(owner);
3607 		conswitchp = csw;
3608 	}
3609 
3610 	first = max(first, con_driver->first);
3611 	last = min(last, con_driver->last);
3612 
3613 	for (i = first; i <= last; i++) {
3614 		int old_was_color;
3615 		struct vc_data *vc = vc_cons[i].d;
3616 
3617 		if (con_driver_map[i])
3618 			module_put(con_driver_map[i]->owner);
3619 		__module_get(owner);
3620 		con_driver_map[i] = csw;
3621 
3622 		if (!vc || !vc->vc_sw)
3623 			continue;
3624 
3625 		j = i;
3626 
3627 		if (con_is_visible(vc)) {
3628 			k = i;
3629 			save_screen(vc);
3630 		}
3631 
3632 		old_was_color = vc->vc_can_do_color;
3633 		vc->vc_sw->con_deinit(vc);
3634 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3635 		visual_init(vc, i, 0);
3636 		set_origin(vc);
3637 		update_attr(vc);
3638 
3639 		/* If the console changed between mono <-> color, then
3640 		 * the attributes in the screenbuf will be wrong.  The
3641 		 * following resets all attributes to something sane.
3642 		 */
3643 		if (old_was_color != vc->vc_can_do_color)
3644 			clear_buffer_attributes(vc);
3645 	}
3646 
3647 	pr_info("Console: switching ");
3648 	if (!deflt)
3649 		pr_cont("consoles %d-%d ", first + 1, last + 1);
3650 	if (j >= 0) {
3651 		struct vc_data *vc = vc_cons[j].d;
3652 
3653 		pr_cont("to %s %s %dx%d\n",
3654 			vc->vc_can_do_color ? "colour" : "mono",
3655 			desc, vc->vc_cols, vc->vc_rows);
3656 
3657 		if (k >= 0) {
3658 			vc = vc_cons[k].d;
3659 			update_screen(vc);
3660 		}
3661 	} else {
3662 		pr_cont("to %s\n", desc);
3663 	}
3664 
3665 	retval = 0;
3666 err:
3667 	module_put(owner);
3668 	return retval;
3669 };
3670 
3671 
3672 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3673 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3674 {
3675 	struct module *owner = csw->owner;
3676 	const struct consw *defcsw = NULL;
3677 	struct con_driver *con_driver = NULL, *con_back = NULL;
3678 	int i, retval = -ENODEV;
3679 
3680 	if (!try_module_get(owner))
3681 		return -ENODEV;
3682 
3683 	WARN_CONSOLE_UNLOCKED();
3684 
3685 	/* check if driver is registered and if it is unbindable */
3686 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3687 		con_driver = &registered_con_driver[i];
3688 
3689 		if (con_driver->con == csw &&
3690 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3691 			retval = 0;
3692 			break;
3693 		}
3694 	}
3695 
3696 	if (retval)
3697 		goto err;
3698 
3699 	retval = -ENODEV;
3700 
3701 	/* check if backup driver exists */
3702 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3703 		con_back = &registered_con_driver[i];
3704 
3705 		if (con_back->con && con_back->con != csw) {
3706 			defcsw = con_back->con;
3707 			retval = 0;
3708 			break;
3709 		}
3710 	}
3711 
3712 	if (retval)
3713 		goto err;
3714 
3715 	if (!con_is_bound(csw))
3716 		goto err;
3717 
3718 	first = max(first, con_driver->first);
3719 	last = min(last, con_driver->last);
3720 
3721 	for (i = first; i <= last; i++) {
3722 		if (con_driver_map[i] == csw) {
3723 			module_put(csw->owner);
3724 			con_driver_map[i] = NULL;
3725 		}
3726 	}
3727 
3728 	if (!con_is_bound(defcsw)) {
3729 		const struct consw *defconsw = conswitchp;
3730 
3731 		defcsw->con_startup();
3732 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3733 		/*
3734 		 * vgacon may change the default driver to point
3735 		 * to dummycon, we restore it here...
3736 		 */
3737 		conswitchp = defconsw;
3738 	}
3739 
3740 	if (!con_is_bound(csw))
3741 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3742 
3743 	/* ignore return value, binding should not fail */
3744 	do_bind_con_driver(defcsw, first, last, deflt);
3745 err:
3746 	module_put(owner);
3747 	return retval;
3748 
3749 }
3750 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3751 
3752 static int vt_bind(struct con_driver *con)
3753 {
3754 	const struct consw *defcsw = NULL, *csw = NULL;
3755 	int i, more = 1, first = -1, last = -1, deflt = 0;
3756 
3757  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3758 		goto err;
3759 
3760 	csw = con->con;
3761 
3762 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3763 		struct con_driver *con = &registered_con_driver[i];
3764 
3765 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3766 			defcsw = con->con;
3767 			break;
3768 		}
3769 	}
3770 
3771 	if (!defcsw)
3772 		goto err;
3773 
3774 	while (more) {
3775 		more = 0;
3776 
3777 		for (i = con->first; i <= con->last; i++) {
3778 			if (con_driver_map[i] == defcsw) {
3779 				if (first == -1)
3780 					first = i;
3781 				last = i;
3782 				more = 1;
3783 			} else if (first != -1)
3784 				break;
3785 		}
3786 
3787 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3788 			deflt = 1;
3789 
3790 		if (first != -1)
3791 			do_bind_con_driver(csw, first, last, deflt);
3792 
3793 		first = -1;
3794 		last = -1;
3795 		deflt = 0;
3796 	}
3797 
3798 err:
3799 	return 0;
3800 }
3801 
3802 static int vt_unbind(struct con_driver *con)
3803 {
3804 	const struct consw *csw = NULL;
3805 	int i, more = 1, first = -1, last = -1, deflt = 0;
3806 	int ret;
3807 
3808  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3809 		goto err;
3810 
3811 	csw = con->con;
3812 
3813 	while (more) {
3814 		more = 0;
3815 
3816 		for (i = con->first; i <= con->last; i++) {
3817 			if (con_driver_map[i] == csw) {
3818 				if (first == -1)
3819 					first = i;
3820 				last = i;
3821 				more = 1;
3822 			} else if (first != -1)
3823 				break;
3824 		}
3825 
3826 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3827 			deflt = 1;
3828 
3829 		if (first != -1) {
3830 			ret = do_unbind_con_driver(csw, first, last, deflt);
3831 			if (ret != 0)
3832 				return ret;
3833 		}
3834 
3835 		first = -1;
3836 		last = -1;
3837 		deflt = 0;
3838 	}
3839 
3840 err:
3841 	return 0;
3842 }
3843 #else
3844 static inline int vt_bind(struct con_driver *con)
3845 {
3846 	return 0;
3847 }
3848 static inline int vt_unbind(struct con_driver *con)
3849 {
3850 	return 0;
3851 }
3852 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3853 
3854 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3855 			  const char *buf, size_t count)
3856 {
3857 	struct con_driver *con = dev_get_drvdata(dev);
3858 	int bind = simple_strtoul(buf, NULL, 0);
3859 
3860 	console_lock();
3861 
3862 	if (bind)
3863 		vt_bind(con);
3864 	else
3865 		vt_unbind(con);
3866 
3867 	console_unlock();
3868 
3869 	return count;
3870 }
3871 
3872 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3873 			 char *buf)
3874 {
3875 	struct con_driver *con = dev_get_drvdata(dev);
3876 	int bind;
3877 
3878 	console_lock();
3879 	bind = con_is_bound(con->con);
3880 	console_unlock();
3881 
3882 	return sysfs_emit(buf, "%i\n", bind);
3883 }
3884 
3885 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3886 			 char *buf)
3887 {
3888 	struct con_driver *con = dev_get_drvdata(dev);
3889 
3890 	return sysfs_emit(buf, "%s %s\n",
3891 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3892 			 con->desc);
3893 
3894 }
3895 
3896 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3897 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3898 
3899 static struct attribute *con_dev_attrs[] = {
3900 	&dev_attr_bind.attr,
3901 	&dev_attr_name.attr,
3902 	NULL
3903 };
3904 
3905 ATTRIBUTE_GROUPS(con_dev);
3906 
3907 static int vtconsole_init_device(struct con_driver *con)
3908 {
3909 	con->flag |= CON_DRIVER_FLAG_ATTR;
3910 	return 0;
3911 }
3912 
3913 static void vtconsole_deinit_device(struct con_driver *con)
3914 {
3915 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3916 }
3917 
3918 /**
3919  * con_is_bound - checks if driver is bound to the console
3920  * @csw: console driver
3921  *
3922  * RETURNS: zero if unbound, nonzero if bound
3923  *
3924  * Drivers can call this and if zero, they should release
3925  * all resources allocated on con_startup()
3926  */
3927 int con_is_bound(const struct consw *csw)
3928 {
3929 	int i, bound = 0;
3930 
3931 	WARN_CONSOLE_UNLOCKED();
3932 
3933 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3934 		if (con_driver_map[i] == csw) {
3935 			bound = 1;
3936 			break;
3937 		}
3938 	}
3939 
3940 	return bound;
3941 }
3942 EXPORT_SYMBOL(con_is_bound);
3943 
3944 /**
3945  * con_is_visible - checks whether the current console is visible
3946  * @vc: virtual console
3947  *
3948  * RETURNS: zero if not visible, nonzero if visible
3949  */
3950 bool con_is_visible(const struct vc_data *vc)
3951 {
3952 	WARN_CONSOLE_UNLOCKED();
3953 
3954 	return *vc->vc_display_fg == vc;
3955 }
3956 EXPORT_SYMBOL(con_is_visible);
3957 
3958 /**
3959  * con_debug_enter - prepare the console for the kernel debugger
3960  * @vc: virtual console
3961  *
3962  * Called when the console is taken over by the kernel debugger, this
3963  * function needs to save the current console state, then put the console
3964  * into a state suitable for the kernel debugger.
3965  *
3966  * RETURNS:
3967  * Zero on success, nonzero if a failure occurred when trying to prepare
3968  * the console for the debugger.
3969  */
3970 int con_debug_enter(struct vc_data *vc)
3971 {
3972 	int ret = 0;
3973 
3974 	saved_fg_console = fg_console;
3975 	saved_last_console = last_console;
3976 	saved_want_console = want_console;
3977 	saved_vc_mode = vc->vc_mode;
3978 	saved_console_blanked = console_blanked;
3979 	vc->vc_mode = KD_TEXT;
3980 	console_blanked = 0;
3981 	if (vc->vc_sw->con_debug_enter)
3982 		ret = vc->vc_sw->con_debug_enter(vc);
3983 #ifdef CONFIG_KGDB_KDB
3984 	/* Set the initial LINES variable if it is not already set */
3985 	if (vc->vc_rows < 999) {
3986 		int linecount;
3987 		char lns[4];
3988 		const char *setargs[3] = {
3989 			"set",
3990 			"LINES",
3991 			lns,
3992 		};
3993 		if (kdbgetintenv(setargs[0], &linecount)) {
3994 			snprintf(lns, 4, "%i", vc->vc_rows);
3995 			kdb_set(2, setargs);
3996 		}
3997 	}
3998 	if (vc->vc_cols < 999) {
3999 		int colcount;
4000 		char cols[4];
4001 		const char *setargs[3] = {
4002 			"set",
4003 			"COLUMNS",
4004 			cols,
4005 		};
4006 		if (kdbgetintenv(setargs[0], &colcount)) {
4007 			snprintf(cols, 4, "%i", vc->vc_cols);
4008 			kdb_set(2, setargs);
4009 		}
4010 	}
4011 #endif /* CONFIG_KGDB_KDB */
4012 	return ret;
4013 }
4014 EXPORT_SYMBOL_GPL(con_debug_enter);
4015 
4016 /**
4017  * con_debug_leave - restore console state
4018  *
4019  * Restore the console state to what it was before the kernel debugger
4020  * was invoked.
4021  *
4022  * RETURNS:
4023  * Zero on success, nonzero if a failure occurred when trying to restore
4024  * the console.
4025  */
4026 int con_debug_leave(void)
4027 {
4028 	struct vc_data *vc;
4029 	int ret = 0;
4030 
4031 	fg_console = saved_fg_console;
4032 	last_console = saved_last_console;
4033 	want_console = saved_want_console;
4034 	console_blanked = saved_console_blanked;
4035 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
4036 
4037 	vc = vc_cons[fg_console].d;
4038 	if (vc->vc_sw->con_debug_leave)
4039 		ret = vc->vc_sw->con_debug_leave(vc);
4040 	return ret;
4041 }
4042 EXPORT_SYMBOL_GPL(con_debug_leave);
4043 
4044 static int do_register_con_driver(const struct consw *csw, int first, int last)
4045 {
4046 	struct module *owner = csw->owner;
4047 	struct con_driver *con_driver;
4048 	const char *desc;
4049 	int i, retval;
4050 
4051 	WARN_CONSOLE_UNLOCKED();
4052 
4053 	if (!try_module_get(owner))
4054 		return -ENODEV;
4055 
4056 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4057 		con_driver = &registered_con_driver[i];
4058 
4059 		/* already registered */
4060 		if (con_driver->con == csw) {
4061 			retval = -EBUSY;
4062 			goto err;
4063 		}
4064 	}
4065 
4066 	desc = csw->con_startup();
4067 	if (!desc) {
4068 		retval = -ENODEV;
4069 		goto err;
4070 	}
4071 
4072 	retval = -EINVAL;
4073 
4074 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4075 		con_driver = &registered_con_driver[i];
4076 
4077 		if (con_driver->con == NULL &&
4078 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
4079 			con_driver->con = csw;
4080 			con_driver->desc = desc;
4081 			con_driver->node = i;
4082 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
4083 			                   CON_DRIVER_FLAG_INIT;
4084 			con_driver->first = first;
4085 			con_driver->last = last;
4086 			retval = 0;
4087 			break;
4088 		}
4089 	}
4090 
4091 	if (retval)
4092 		goto err;
4093 
4094 	con_driver->dev =
4095 		device_create_with_groups(vtconsole_class, NULL,
4096 					  MKDEV(0, con_driver->node),
4097 					  con_driver, con_dev_groups,
4098 					  "vtcon%i", con_driver->node);
4099 	if (IS_ERR(con_driver->dev)) {
4100 		pr_warn("Unable to create device for %s; errno = %ld\n",
4101 			con_driver->desc, PTR_ERR(con_driver->dev));
4102 		con_driver->dev = NULL;
4103 	} else {
4104 		vtconsole_init_device(con_driver);
4105 	}
4106 
4107 err:
4108 	module_put(owner);
4109 	return retval;
4110 }
4111 
4112 
4113 /**
4114  * do_unregister_con_driver - unregister console driver from console layer
4115  * @csw: console driver
4116  *
4117  * DESCRIPTION: All drivers that registers to the console layer must
4118  * call this function upon exit, or if the console driver is in a state
4119  * where it won't be able to handle console services, such as the
4120  * framebuffer console without loaded framebuffer drivers.
4121  *
4122  * The driver must unbind first prior to unregistration.
4123  */
4124 int do_unregister_con_driver(const struct consw *csw)
4125 {
4126 	int i;
4127 
4128 	/* cannot unregister a bound driver */
4129 	if (con_is_bound(csw))
4130 		return -EBUSY;
4131 
4132 	if (csw == conswitchp)
4133 		return -EINVAL;
4134 
4135 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4136 		struct con_driver *con_driver = &registered_con_driver[i];
4137 
4138 		if (con_driver->con == csw) {
4139 			/*
4140 			 * Defer the removal of the sysfs entries since that
4141 			 * will acquire the kernfs s_active lock and we can't
4142 			 * acquire this lock while holding the console lock:
4143 			 * the unbind sysfs entry imposes already the opposite
4144 			 * order. Reset con already here to prevent any later
4145 			 * lookup to succeed and mark this slot as zombie, so
4146 			 * it won't get reused until we complete the removal
4147 			 * in the deferred work.
4148 			 */
4149 			con_driver->con = NULL;
4150 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4151 			schedule_work(&con_driver_unregister_work);
4152 
4153 			return 0;
4154 		}
4155 	}
4156 
4157 	return -ENODEV;
4158 }
4159 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4160 
4161 static void con_driver_unregister_callback(struct work_struct *ignored)
4162 {
4163 	int i;
4164 
4165 	console_lock();
4166 
4167 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4168 		struct con_driver *con_driver = &registered_con_driver[i];
4169 
4170 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4171 			continue;
4172 
4173 		console_unlock();
4174 
4175 		vtconsole_deinit_device(con_driver);
4176 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4177 
4178 		console_lock();
4179 
4180 		if (WARN_ON_ONCE(con_driver->con))
4181 			con_driver->con = NULL;
4182 		con_driver->desc = NULL;
4183 		con_driver->dev = NULL;
4184 		con_driver->node = 0;
4185 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4186 		con_driver->flag = 0;
4187 		con_driver->first = 0;
4188 		con_driver->last = 0;
4189 	}
4190 
4191 	console_unlock();
4192 }
4193 
4194 /*
4195  *	If we support more console drivers, this function is used
4196  *	when a driver wants to take over some existing consoles
4197  *	and become default driver for newly opened ones.
4198  *
4199  *	do_take_over_console is basically a register followed by bind
4200  */
4201 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4202 {
4203 	int err;
4204 
4205 	err = do_register_con_driver(csw, first, last);
4206 	/*
4207 	 * If we get an busy error we still want to bind the console driver
4208 	 * and return success, as we may have unbound the console driver
4209 	 * but not unregistered it.
4210 	 */
4211 	if (err == -EBUSY)
4212 		err = 0;
4213 	if (!err)
4214 		do_bind_con_driver(csw, first, last, deflt);
4215 
4216 	return err;
4217 }
4218 EXPORT_SYMBOL_GPL(do_take_over_console);
4219 
4220 
4221 /*
4222  * give_up_console is a wrapper to unregister_con_driver. It will only
4223  * work if driver is fully unbound.
4224  */
4225 void give_up_console(const struct consw *csw)
4226 {
4227 	console_lock();
4228 	do_unregister_con_driver(csw);
4229 	console_unlock();
4230 }
4231 EXPORT_SYMBOL(give_up_console);
4232 
4233 static int __init vtconsole_class_init(void)
4234 {
4235 	int i;
4236 
4237 	vtconsole_class = class_create("vtconsole");
4238 	if (IS_ERR(vtconsole_class)) {
4239 		pr_warn("Unable to create vt console class; errno = %ld\n",
4240 			PTR_ERR(vtconsole_class));
4241 		vtconsole_class = NULL;
4242 	}
4243 
4244 	/* Add system drivers to sysfs */
4245 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4246 		struct con_driver *con = &registered_con_driver[i];
4247 
4248 		if (con->con && !con->dev) {
4249 			con->dev =
4250 				device_create_with_groups(vtconsole_class, NULL,
4251 							  MKDEV(0, con->node),
4252 							  con, con_dev_groups,
4253 							  "vtcon%i", con->node);
4254 
4255 			if (IS_ERR(con->dev)) {
4256 				pr_warn("Unable to create device for %s; errno = %ld\n",
4257 					con->desc, PTR_ERR(con->dev));
4258 				con->dev = NULL;
4259 			} else {
4260 				vtconsole_init_device(con);
4261 			}
4262 		}
4263 	}
4264 
4265 	return 0;
4266 }
4267 postcore_initcall(vtconsole_class_init);
4268 
4269 /*
4270  *	Screen blanking
4271  */
4272 
4273 static int set_vesa_blanking(char __user *p)
4274 {
4275 	unsigned int mode;
4276 
4277 	if (get_user(mode, p + 1))
4278 		return -EFAULT;
4279 
4280 	vesa_blank_mode = (mode < 4) ? mode : 0;
4281 	return 0;
4282 }
4283 
4284 void do_blank_screen(int entering_gfx)
4285 {
4286 	struct vc_data *vc = vc_cons[fg_console].d;
4287 	int i;
4288 
4289 	might_sleep();
4290 
4291 	WARN_CONSOLE_UNLOCKED();
4292 
4293 	if (console_blanked) {
4294 		if (blank_state == blank_vesa_wait) {
4295 			blank_state = blank_off;
4296 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4297 		}
4298 		return;
4299 	}
4300 
4301 	/* entering graphics mode? */
4302 	if (entering_gfx) {
4303 		hide_cursor(vc);
4304 		save_screen(vc);
4305 		vc->vc_sw->con_blank(vc, -1, 1);
4306 		console_blanked = fg_console + 1;
4307 		blank_state = blank_off;
4308 		set_origin(vc);
4309 		return;
4310 	}
4311 
4312 	blank_state = blank_off;
4313 
4314 	/* don't blank graphics */
4315 	if (vc->vc_mode != KD_TEXT) {
4316 		console_blanked = fg_console + 1;
4317 		return;
4318 	}
4319 
4320 	hide_cursor(vc);
4321 	del_timer_sync(&console_timer);
4322 	blank_timer_expired = 0;
4323 
4324 	save_screen(vc);
4325 	/* In case we need to reset origin, blanking hook returns 1 */
4326 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4327 	console_blanked = fg_console + 1;
4328 	if (i)
4329 		set_origin(vc);
4330 
4331 	if (console_blank_hook && console_blank_hook(1))
4332 		return;
4333 
4334 	if (vesa_off_interval && vesa_blank_mode) {
4335 		blank_state = blank_vesa_wait;
4336 		mod_timer(&console_timer, jiffies + vesa_off_interval);
4337 	}
4338 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4339 }
4340 EXPORT_SYMBOL(do_blank_screen);
4341 
4342 /*
4343  * Called by timer as well as from vt_console_driver
4344  */
4345 void do_unblank_screen(int leaving_gfx)
4346 {
4347 	struct vc_data *vc;
4348 
4349 	/* This should now always be called from a "sane" (read: can schedule)
4350 	 * context for the sake of the low level drivers, except in the special
4351 	 * case of oops_in_progress
4352 	 */
4353 	if (!oops_in_progress)
4354 		might_sleep();
4355 
4356 	WARN_CONSOLE_UNLOCKED();
4357 
4358 	ignore_poke = 0;
4359 	if (!console_blanked)
4360 		return;
4361 	if (!vc_cons_allocated(fg_console)) {
4362 		/* impossible */
4363 		pr_warn("unblank_screen: tty %d not allocated ??\n",
4364 			fg_console + 1);
4365 		return;
4366 	}
4367 	vc = vc_cons[fg_console].d;
4368 	if (vc->vc_mode != KD_TEXT)
4369 		return; /* but leave console_blanked != 0 */
4370 
4371 	if (blankinterval) {
4372 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4373 		blank_state = blank_normal_wait;
4374 	}
4375 
4376 	console_blanked = 0;
4377 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4378 		/* Low-level driver cannot restore -> do it ourselves */
4379 		update_screen(vc);
4380 	if (console_blank_hook)
4381 		console_blank_hook(0);
4382 	set_palette(vc);
4383 	set_cursor(vc);
4384 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4385 }
4386 EXPORT_SYMBOL(do_unblank_screen);
4387 
4388 /*
4389  * This is called by the outside world to cause a forced unblank, mostly for
4390  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4391  * call it with 1 as an argument and so force a mode restore... that may kill
4392  * X or at least garbage the screen but would also make the Oops visible...
4393  */
4394 static void unblank_screen(void)
4395 {
4396 	do_unblank_screen(0);
4397 }
4398 
4399 /*
4400  * We defer the timer blanking to work queue so it can take the console mutex
4401  * (console operations can still happen at irq time, but only from printk which
4402  * has the console mutex. Not perfect yet, but better than no locking
4403  */
4404 static void blank_screen_t(struct timer_list *unused)
4405 {
4406 	blank_timer_expired = 1;
4407 	schedule_work(&console_work);
4408 }
4409 
4410 void poke_blanked_console(void)
4411 {
4412 	WARN_CONSOLE_UNLOCKED();
4413 
4414 	/* Add this so we quickly catch whoever might call us in a non
4415 	 * safe context. Nowadays, unblank_screen() isn't to be called in
4416 	 * atomic contexts and is allowed to schedule (with the special case
4417 	 * of oops_in_progress, but that isn't of any concern for this
4418 	 * function. --BenH.
4419 	 */
4420 	might_sleep();
4421 
4422 	/* This isn't perfectly race free, but a race here would be mostly harmless,
4423 	 * at worst, we'll do a spurious blank and it's unlikely
4424 	 */
4425 	del_timer(&console_timer);
4426 	blank_timer_expired = 0;
4427 
4428 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4429 		return;
4430 	if (console_blanked)
4431 		unblank_screen();
4432 	else if (blankinterval) {
4433 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4434 		blank_state = blank_normal_wait;
4435 	}
4436 }
4437 
4438 /*
4439  *	Palettes
4440  */
4441 
4442 static void set_palette(struct vc_data *vc)
4443 {
4444 	WARN_CONSOLE_UNLOCKED();
4445 
4446 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4447 		vc->vc_sw->con_set_palette(vc, color_table);
4448 }
4449 
4450 /*
4451  * Load palette into the DAC registers. arg points to a colour
4452  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4453  */
4454 
4455 int con_set_cmap(unsigned char __user *arg)
4456 {
4457 	int i, j, k;
4458 	unsigned char colormap[3*16];
4459 
4460 	if (copy_from_user(colormap, arg, sizeof(colormap)))
4461 		return -EFAULT;
4462 
4463 	console_lock();
4464 	for (i = k = 0; i < 16; i++) {
4465 		default_red[i] = colormap[k++];
4466 		default_grn[i] = colormap[k++];
4467 		default_blu[i] = colormap[k++];
4468 	}
4469 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
4470 		if (!vc_cons_allocated(i))
4471 			continue;
4472 		for (j = k = 0; j < 16; j++) {
4473 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4474 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4475 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4476 		}
4477 		set_palette(vc_cons[i].d);
4478 	}
4479 	console_unlock();
4480 
4481 	return 0;
4482 }
4483 
4484 int con_get_cmap(unsigned char __user *arg)
4485 {
4486 	int i, k;
4487 	unsigned char colormap[3*16];
4488 
4489 	console_lock();
4490 	for (i = k = 0; i < 16; i++) {
4491 		colormap[k++] = default_red[i];
4492 		colormap[k++] = default_grn[i];
4493 		colormap[k++] = default_blu[i];
4494 	}
4495 	console_unlock();
4496 
4497 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4498 		return -EFAULT;
4499 
4500 	return 0;
4501 }
4502 
4503 void reset_palette(struct vc_data *vc)
4504 {
4505 	int j, k;
4506 	for (j=k=0; j<16; j++) {
4507 		vc->vc_palette[k++] = default_red[j];
4508 		vc->vc_palette[k++] = default_grn[j];
4509 		vc->vc_palette[k++] = default_blu[j];
4510 	}
4511 	set_palette(vc);
4512 }
4513 
4514 /*
4515  *  Font switching
4516  *
4517  *  Currently we only support fonts up to 128 pixels wide, at a maximum height
4518  *  of 128 pixels. Userspace fontdata may have to be stored with 32 bytes
4519  *  (shorts/ints, depending on width) reserved for each character which is
4520  *  kinda wasty, but this is done in order to maintain compatibility with the
4521  *  EGA/VGA fonts. It is up to the actual low-level console-driver convert data
4522  *  into its favorite format (maybe we should add a `fontoffset' field to the
4523  *  `display' structure so we won't have to convert the fontdata all the time.
4524  *  /Jes
4525  */
4526 
4527 #define max_font_width	64
4528 #define max_font_height	128
4529 #define max_font_glyphs	512
4530 #define max_font_size	(max_font_glyphs*max_font_width*max_font_height)
4531 
4532 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4533 {
4534 	struct console_font font;
4535 	int rc = -EINVAL;
4536 	int c;
4537 	unsigned int vpitch = op->op == KD_FONT_OP_GET_TALL ? op->height : 32;
4538 
4539 	if (vpitch > max_font_height)
4540 		return -EINVAL;
4541 
4542 	if (op->data) {
4543 		font.data = kvmalloc(max_font_size, GFP_KERNEL);
4544 		if (!font.data)
4545 			return -ENOMEM;
4546 	} else
4547 		font.data = NULL;
4548 
4549 	console_lock();
4550 	if (vc->vc_mode != KD_TEXT)
4551 		rc = -EINVAL;
4552 	else if (vc->vc_sw->con_font_get)
4553 		rc = vc->vc_sw->con_font_get(vc, &font, vpitch);
4554 	else
4555 		rc = -ENOSYS;
4556 	console_unlock();
4557 
4558 	if (rc)
4559 		goto out;
4560 
4561 	c = (font.width+7)/8 * vpitch * font.charcount;
4562 
4563 	if (op->data && font.charcount > op->charcount)
4564 		rc = -ENOSPC;
4565 	if (font.width > op->width || font.height > op->height)
4566 		rc = -ENOSPC;
4567 	if (rc)
4568 		goto out;
4569 
4570 	op->height = font.height;
4571 	op->width = font.width;
4572 	op->charcount = font.charcount;
4573 
4574 	if (op->data && copy_to_user(op->data, font.data, c))
4575 		rc = -EFAULT;
4576 
4577 out:
4578 	kvfree(font.data);
4579 	return rc;
4580 }
4581 
4582 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4583 {
4584 	struct console_font font;
4585 	int rc = -EINVAL;
4586 	int size;
4587 	unsigned int vpitch = op->op == KD_FONT_OP_SET_TALL ? op->height : 32;
4588 
4589 	if (vc->vc_mode != KD_TEXT)
4590 		return -EINVAL;
4591 	if (!op->data)
4592 		return -EINVAL;
4593 	if (op->charcount > max_font_glyphs)
4594 		return -EINVAL;
4595 	if (op->width <= 0 || op->width > max_font_width || !op->height ||
4596 	    op->height > max_font_height)
4597 		return -EINVAL;
4598 	if (vpitch < op->height)
4599 		return -EINVAL;
4600 	size = (op->width+7)/8 * vpitch * op->charcount;
4601 	if (size > max_font_size)
4602 		return -ENOSPC;
4603 
4604 	font.data = memdup_user(op->data, size);
4605 	if (IS_ERR(font.data))
4606 		return PTR_ERR(font.data);
4607 
4608 	font.charcount = op->charcount;
4609 	font.width = op->width;
4610 	font.height = op->height;
4611 
4612 	console_lock();
4613 	if (vc->vc_mode != KD_TEXT)
4614 		rc = -EINVAL;
4615 	else if (vc->vc_sw->con_font_set) {
4616 		if (vc_is_sel(vc))
4617 			clear_selection();
4618 		rc = vc->vc_sw->con_font_set(vc, &font, vpitch, op->flags);
4619 	} else
4620 		rc = -ENOSYS;
4621 	console_unlock();
4622 	kfree(font.data);
4623 	return rc;
4624 }
4625 
4626 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4627 {
4628 	struct console_font font = {.width = op->width, .height = op->height};
4629 	char name[MAX_FONT_NAME];
4630 	char *s = name;
4631 	int rc;
4632 
4633 
4634 	if (!op->data)
4635 		s = NULL;
4636 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4637 		return -EFAULT;
4638 	else
4639 		name[MAX_FONT_NAME - 1] = 0;
4640 
4641 	console_lock();
4642 	if (vc->vc_mode != KD_TEXT) {
4643 		console_unlock();
4644 		return -EINVAL;
4645 	}
4646 	if (vc->vc_sw->con_font_default) {
4647 		if (vc_is_sel(vc))
4648 			clear_selection();
4649 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4650 	} else
4651 		rc = -ENOSYS;
4652 	console_unlock();
4653 	if (!rc) {
4654 		op->width = font.width;
4655 		op->height = font.height;
4656 	}
4657 	return rc;
4658 }
4659 
4660 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4661 {
4662 	switch (op->op) {
4663 	case KD_FONT_OP_SET:
4664 	case KD_FONT_OP_SET_TALL:
4665 		return con_font_set(vc, op);
4666 	case KD_FONT_OP_GET:
4667 	case KD_FONT_OP_GET_TALL:
4668 		return con_font_get(vc, op);
4669 	case KD_FONT_OP_SET_DEFAULT:
4670 		return con_font_default(vc, op);
4671 	case KD_FONT_OP_COPY:
4672 		/* was buggy and never really used */
4673 		return -EINVAL;
4674 	}
4675 	return -ENOSYS;
4676 }
4677 
4678 /*
4679  *	Interface exported to selection and vcs.
4680  */
4681 
4682 /* used by selection */
4683 u16 screen_glyph(const struct vc_data *vc, int offset)
4684 {
4685 	u16 w = scr_readw(screenpos(vc, offset, true));
4686 	u16 c = w & 0xff;
4687 
4688 	if (w & vc->vc_hi_font_mask)
4689 		c |= 0x100;
4690 	return c;
4691 }
4692 EXPORT_SYMBOL_GPL(screen_glyph);
4693 
4694 u32 screen_glyph_unicode(const struct vc_data *vc, int n)
4695 {
4696 	u32 **uni_lines = vc->vc_uni_lines;
4697 
4698 	if (uni_lines)
4699 		return uni_lines[n / vc->vc_cols][n % vc->vc_cols];
4700 
4701 	return inverse_translate(vc, screen_glyph(vc, n * 2), true);
4702 }
4703 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4704 
4705 /* used by vcs - note the word offset */
4706 unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
4707 {
4708 	return screenpos(vc, 2 * w_offset, viewed);
4709 }
4710 EXPORT_SYMBOL_GPL(screen_pos);
4711 
4712 void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
4713 {
4714 	/* clamp values if they don't fit */
4715 	xy[0] = min(vc->state.x, 0xFFu);
4716 	xy[1] = min(vc->state.y, 0xFFu);
4717 }
4718 
4719 void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
4720 {
4721 	hide_cursor(vc);
4722 	gotoxy(vc, xy[0], xy[1]);
4723 	set_cursor(vc);
4724 }
4725 
4726 u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
4727 {
4728 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4729 		return softcursor_original;
4730 	return scr_readw(org);
4731 }
4732 
4733 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4734 {
4735 	scr_writew(val, org);
4736 	if ((unsigned long)org == vc->vc_pos) {
4737 		softcursor_original = -1;
4738 		add_softcursor(vc);
4739 	}
4740 }
4741 
4742 void vcs_scr_updated(struct vc_data *vc)
4743 {
4744 	notify_update(vc);
4745 }
4746 
4747 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4748 		unsigned int rolled_over, void *base, unsigned int size)
4749 {
4750 	unsigned long ubase = (unsigned long)base;
4751 	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4752 	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4753 	ptrdiff_t origin = (void *)c->vc_origin - base;
4754 	int margin = c->vc_size_row * 4;
4755 	int from, wrap, from_off, avail;
4756 
4757 	/* Turn scrollback off */
4758 	if (!lines) {
4759 		c->vc_visible_origin = c->vc_origin;
4760 		return;
4761 	}
4762 
4763 	/* Do we have already enough to allow jumping from 0 to the end? */
4764 	if (rolled_over > scr_end + margin) {
4765 		from = scr_end;
4766 		wrap = rolled_over + c->vc_size_row;
4767 	} else {
4768 		from = 0;
4769 		wrap = size;
4770 	}
4771 
4772 	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4773 	avail = (origin - from + wrap) % wrap;
4774 
4775 	/* Only a little piece would be left? Show all incl. the piece! */
4776 	if (avail < 2 * margin)
4777 		margin = 0;
4778 	if (from_off < margin)
4779 		from_off = 0;
4780 	if (from_off > avail - margin)
4781 		from_off = avail;
4782 
4783 	c->vc_visible_origin = ubase + (from + from_off) % wrap;
4784 }
4785 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4786