xref: /linux/drivers/tty/vt/vt.c (revision 68a052239fc4b351e961f698b824f7654a346091)
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/gcd.h>
108 
109 #define MAX_NR_CON_DRIVER 16
110 
111 #define CON_DRIVER_FLAG_MODULE 1
112 #define CON_DRIVER_FLAG_INIT   2
113 #define CON_DRIVER_FLAG_ATTR   4
114 #define CON_DRIVER_FLAG_ZOMBIE 8
115 
116 struct con_driver {
117 	const struct consw *con;
118 	const char *desc;
119 	struct device *dev;
120 	int node;
121 	int first;
122 	int last;
123 	int flag;
124 };
125 
126 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
127 const struct consw *conswitchp;
128 
129 /*
130  * Here is the default bell parameters: 750HZ, 1/8th of a second
131  */
132 #define DEFAULT_BELL_PITCH	750
133 #define DEFAULT_BELL_DURATION	(HZ/8)
134 #define DEFAULT_CURSOR_BLINK_MS	200
135 
136 struct vc vc_cons [MAX_NR_CONSOLES];
137 EXPORT_SYMBOL(vc_cons);
138 
139 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
140 
141 static int con_open(struct tty_struct *, struct file *);
142 static void vc_init(struct vc_data *vc, int do_clear);
143 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
144 static void restore_cur(struct vc_data *vc);
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(u8 __user *mode);
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 enum vesa_blank_mode vesa_blank_mode;
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 u16 *screenpos(const struct vc_data *vc, unsigned int offset,
290 			     bool viewed)
291 {
292 	unsigned long origin = viewed ? vc->vc_visible_origin : vc->vc_origin;
293 
294 	return (u16 *)(origin + offset);
295 }
296 
297 static void con_putc(struct vc_data *vc, u16 ca, unsigned int y, unsigned int x)
298 {
299 	if (vc->vc_sw->con_putc)
300 		vc->vc_sw->con_putc(vc, ca, y, x);
301 	else
302 		vc->vc_sw->con_putcs(vc, &ca, 1, y, x);
303 }
304 
305 /* Called  from the keyboard irq path.. */
306 static inline void scrolldelta(int lines)
307 {
308 	/* FIXME */
309 	/* scrolldelta needs some kind of consistency lock, but the BKL was
310 	   and still is not protecting versus the scheduled back end */
311 	scrollback_delta += lines;
312 	schedule_console_callback();
313 }
314 
315 void schedule_console_callback(void)
316 {
317 	schedule_work(&console_work);
318 }
319 
320 /*
321  * Code to manage unicode-based screen buffers
322  */
323 
324 /*
325  * Our screen buffer is preceded by an array of line pointers so that
326  * scrolling only implies some pointer shuffling.
327  */
328 
329 static u32 **vc_uniscr_alloc(unsigned int cols, unsigned int rows)
330 {
331 	u32 **uni_lines;
332 	void *p;
333 	unsigned int memsize, i, col_size = cols * sizeof(**uni_lines);
334 
335 	/* allocate everything in one go */
336 	memsize = col_size * rows;
337 	memsize += rows * sizeof(*uni_lines);
338 	uni_lines = vzalloc(memsize);
339 	if (!uni_lines)
340 		return NULL;
341 
342 	/* initial line pointers */
343 	p = uni_lines + rows;
344 	for (i = 0; i < rows; i++) {
345 		uni_lines[i] = p;
346 		p += col_size;
347 	}
348 
349 	return uni_lines;
350 }
351 
352 static void vc_uniscr_free(u32 **uni_lines)
353 {
354 	vfree(uni_lines);
355 }
356 
357 static void vc_uniscr_set(struct vc_data *vc, u32 **new_uni_lines)
358 {
359 	vc_uniscr_free(vc->vc_uni_lines);
360 	vc->vc_uni_lines = new_uni_lines;
361 }
362 
363 static void vc_uniscr_putc(struct vc_data *vc, u32 uc)
364 {
365 	if (vc->vc_uni_lines)
366 		vc->vc_uni_lines[vc->state.y][vc->state.x] = uc;
367 }
368 
369 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
370 {
371 	if (vc->vc_uni_lines) {
372 		u32 *ln = vc->vc_uni_lines[vc->state.y];
373 		unsigned int x = vc->state.x, cols = vc->vc_cols;
374 
375 		memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
376 		memset32(&ln[x], ' ', nr);
377 	}
378 }
379 
380 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
381 {
382 	if (vc->vc_uni_lines) {
383 		u32 *ln = vc->vc_uni_lines[vc->state.y];
384 		unsigned int x = vc->state.x, cols = vc->vc_cols;
385 
386 		memmove(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
387 		memset32(&ln[cols - nr], ' ', nr);
388 	}
389 }
390 
391 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
392 				 unsigned int nr)
393 {
394 	if (vc->vc_uni_lines)
395 		memset32(&vc->vc_uni_lines[vc->state.y][x], ' ', nr);
396 }
397 
398 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
399 				  unsigned int nr)
400 {
401 	if (vc->vc_uni_lines)
402 		while (nr--)
403 			memset32(vc->vc_uni_lines[y++], ' ', vc->vc_cols);
404 }
405 
406 /* juggling array rotation algorithm (complexity O(N), size complexity O(1)) */
407 static void juggle_array(u32 **array, unsigned int size, unsigned int nr)
408 {
409 	unsigned int gcd_idx;
410 
411 	for (gcd_idx = 0; gcd_idx < gcd(nr, size); gcd_idx++) {
412 		u32 *gcd_idx_val = array[gcd_idx];
413 		unsigned int dst_idx = gcd_idx;
414 
415 		while (1) {
416 			unsigned int src_idx = (dst_idx + nr) % size;
417 			if (src_idx == gcd_idx)
418 				break;
419 
420 			array[dst_idx] = array[src_idx];
421 			dst_idx = src_idx;
422 		}
423 
424 		array[dst_idx] = gcd_idx_val;
425 	}
426 }
427 
428 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int top,
429 			     unsigned int bottom, enum con_scroll dir,
430 			     unsigned int nr)
431 {
432 	u32 **uni_lines = vc->vc_uni_lines;
433 	unsigned int size = bottom - top;
434 
435 	if (!uni_lines)
436 		return;
437 
438 	if (dir == SM_DOWN) {
439 		juggle_array(&uni_lines[top], size, size - nr);
440 		vc_uniscr_clear_lines(vc, top, nr);
441 	} else {
442 		juggle_array(&uni_lines[top], size, nr);
443 		vc_uniscr_clear_lines(vc, bottom - nr, nr);
444 	}
445 }
446 
447 static u32 vc_uniscr_getc(struct vc_data *vc, int relative_pos)
448 {
449 	int pos = vc->state.x + vc->vc_need_wrap + relative_pos;
450 
451 	if (vc->vc_uni_lines && in_range(pos, 0, vc->vc_cols))
452 		return vc->vc_uni_lines[vc->state.y][pos];
453 	return 0;
454 }
455 
456 static void vc_uniscr_copy_area(u32 **dst_lines,
457 				unsigned int dst_cols,
458 				unsigned int dst_rows,
459 				u32 **src_lines,
460 				unsigned int src_cols,
461 				unsigned int src_top_row,
462 				unsigned int src_bot_row)
463 {
464 	unsigned int dst_row = 0;
465 
466 	if (!dst_lines)
467 		return;
468 
469 	while (src_top_row < src_bot_row) {
470 		u32 *src_line = src_lines[src_top_row];
471 		u32 *dst_line = dst_lines[dst_row];
472 
473 		memcpy(dst_line, src_line, src_cols * sizeof(*src_line));
474 		if (dst_cols - src_cols)
475 			memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
476 		src_top_row++;
477 		dst_row++;
478 	}
479 	while (dst_row < dst_rows) {
480 		u32 *dst_line = dst_lines[dst_row];
481 
482 		memset32(dst_line, ' ', dst_cols);
483 		dst_row++;
484 	}
485 }
486 
487 /*
488  * Called from vcs_read() to make sure unicode screen retrieval is possible.
489  * This will initialize the unicode screen buffer if not already done.
490  * This returns 0 if OK, or a negative error code otherwise.
491  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
492  */
493 int vc_uniscr_check(struct vc_data *vc)
494 {
495 	u32 **uni_lines;
496 	unsigned short *p;
497 	int x, y, mask;
498 
499 	WARN_CONSOLE_UNLOCKED();
500 
501 	if (!vc->vc_utf)
502 		return -ENODATA;
503 
504 	if (vc->vc_uni_lines)
505 		return 0;
506 
507 	uni_lines = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
508 	if (!uni_lines)
509 		return -ENOMEM;
510 
511 	/*
512 	 * Let's populate it initially with (imperfect) reverse translation.
513 	 * This is the next best thing we can do short of having it enabled
514 	 * from the start even when no users rely on this functionality. True
515 	 * unicode content will be available after a complete screen refresh.
516 	 */
517 	p = (unsigned short *)vc->vc_origin;
518 	mask = vc->vc_hi_font_mask | 0xff;
519 	for (y = 0; y < vc->vc_rows; y++) {
520 		u32 *line = uni_lines[y];
521 		for (x = 0; x < vc->vc_cols; x++) {
522 			u16 glyph = scr_readw(p++) & mask;
523 			line[x] = inverse_translate(vc, glyph, true);
524 		}
525 	}
526 
527 	vc->vc_uni_lines = uni_lines;
528 
529 	return 0;
530 }
531 
532 /*
533  * Called from vcs_read() to get the unicode data from the screen.
534  * This must be preceded by a successful call to vc_uniscr_check() once
535  * the console lock has been taken.
536  */
537 void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed,
538 			 unsigned int row, unsigned int col, unsigned int nr)
539 {
540 	u32 **uni_lines = vc->vc_uni_lines;
541 	int offset = row * vc->vc_size_row + col * 2;
542 	unsigned long pos;
543 
544 	if (WARN_ON_ONCE(!uni_lines))
545 		return;
546 
547 	pos = (unsigned long)screenpos(vc, offset, viewed);
548 	if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
549 		/*
550 		 * Desired position falls in the main screen buffer.
551 		 * However the actual row/col might be different if
552 		 * scrollback is active.
553 		 */
554 		row = (pos - vc->vc_origin) / vc->vc_size_row;
555 		col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
556 		memcpy(dest, &uni_lines[row][col], nr * sizeof(u32));
557 	} else {
558 		/*
559 		 * Scrollback is active. For now let's simply backtranslate
560 		 * the screen glyphs until the unicode screen buffer does
561 		 * synchronize with console display drivers for a scrollback
562 		 * buffer of its own.
563 		 */
564 		u16 *p = (u16 *)pos;
565 		int mask = vc->vc_hi_font_mask | 0xff;
566 		u32 *uni_buf = dest;
567 		while (nr--) {
568 			u16 glyph = scr_readw(p++) & mask;
569 			*uni_buf++ = inverse_translate(vc, glyph, true);
570 		}
571 	}
572 }
573 
574 static void con_scroll(struct vc_data *vc, unsigned int top,
575 		       unsigned int bottom, enum con_scroll dir,
576 		       unsigned int nr)
577 {
578 	unsigned int rows = bottom - top;
579 	u16 *clear, *dst, *src;
580 
581 	if (top + nr >= bottom)
582 		nr = rows - 1;
583 	if (bottom > vc->vc_rows || top >= bottom || nr < 1)
584 		return;
585 
586 	vc_uniscr_scroll(vc, top, bottom, dir, nr);
587 	if (con_is_visible(vc) &&
588 			vc->vc_sw->con_scroll(vc, top, bottom, dir, nr))
589 		return;
590 
591 	src = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * top);
592 	dst = (u16 *)(vc->vc_origin + vc->vc_size_row * (top + nr));
593 
594 	if (dir == SM_UP) {
595 		clear = src + (rows - nr) * vc->vc_cols;
596 		swap(src, dst);
597 	}
598 	scr_memmovew(dst, src, (rows - nr) * vc->vc_size_row);
599 	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
600 }
601 
602 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
603 {
604 	unsigned int xx, yy, offset;
605 	u16 *p = (u16 *)start;
606 
607 	offset = (start - vc->vc_origin) / 2;
608 	xx = offset % vc->vc_cols;
609 	yy = offset / vc->vc_cols;
610 
611 	for(;;) {
612 		u16 attrib = scr_readw(p) & 0xff00;
613 		int startx = xx;
614 		u16 *q = p;
615 		while (xx < vc->vc_cols && count) {
616 			if (attrib != (scr_readw(p) & 0xff00)) {
617 				if (p > q)
618 					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
619 				startx = xx;
620 				q = p;
621 				attrib = scr_readw(p) & 0xff00;
622 			}
623 			p++;
624 			xx++;
625 			count--;
626 		}
627 		if (p > q)
628 			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
629 		if (!count)
630 			break;
631 		xx = 0;
632 		yy++;
633 	}
634 }
635 
636 void update_region(struct vc_data *vc, unsigned long start, int count)
637 {
638 	WARN_CONSOLE_UNLOCKED();
639 
640 	if (con_should_update(vc)) {
641 		hide_cursor(vc);
642 		do_update_region(vc, start, count);
643 		set_cursor(vc);
644 	}
645 }
646 EXPORT_SYMBOL(update_region);
647 
648 /* Structure of attributes is hardware-dependent */
649 
650 static u8 build_attr(struct vc_data *vc, u8 _color,
651 		enum vc_intensity _intensity, bool _blink, bool _underline,
652 		bool _reverse, bool _italic)
653 {
654 	if (vc->vc_sw->con_build_attr)
655 		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
656 		       _blink, _underline, _reverse, _italic);
657 
658 /*
659  * ++roman: I completely changed the attribute format for monochrome
660  * mode (!can_do_color). The formerly used MDA (monochrome display
661  * adapter) format didn't allow the combination of certain effects.
662  * Now the attribute is just a bit vector:
663  *  Bit 0..1: intensity (0..2)
664  *  Bit 2   : underline
665  *  Bit 3   : reverse
666  *  Bit 7   : blink
667  */
668 	{
669 	u8 a = _color;
670 	if (!vc->vc_can_do_color)
671 		return _intensity |
672 		       (_italic    << 1) |
673 		       (_underline << 2) |
674 		       (_reverse   << 3) |
675 		       (_blink     << 7);
676 	if (_italic)
677 		a = (a & 0xF0) | vc->vc_itcolor;
678 	else if (_underline)
679 		a = (a & 0xf0) | vc->vc_ulcolor;
680 	else if (_intensity == VCI_HALF_BRIGHT)
681 		a = (a & 0xf0) | vc->vc_halfcolor;
682 	if (_reverse)
683 		a = (a & 0x88) | (((a >> 4) | (a << 4)) & 0x77);
684 	if (_blink)
685 		a ^= 0x80;
686 	if (_intensity == VCI_BOLD)
687 		a ^= 0x08;
688 	if (vc->vc_hi_font_mask == 0x100)
689 		a <<= 1;
690 	return a;
691 	}
692 }
693 
694 static void update_attr(struct vc_data *vc)
695 {
696 	vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
697 	              vc->state.blink, vc->state.underline,
698 	              vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
699 	vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
700 				VCI_NORMAL, vc->state.blink, false,
701 				vc->vc_decscnm, false) << 8);
702 }
703 
704 /* Note: inverting the screen twice should revert to the original state */
705 void invert_screen(struct vc_data *vc, int offset, int count, bool viewed)
706 {
707 	u16 *p;
708 
709 	WARN_CONSOLE_UNLOCKED();
710 
711 	count /= 2;
712 	p = screenpos(vc, offset, viewed);
713 	if (vc->vc_sw->con_invert_region) {
714 		vc->vc_sw->con_invert_region(vc, p, count);
715 	} else {
716 		u16 *q = p;
717 		int cnt = count;
718 		u16 a;
719 
720 		if (!vc->vc_can_do_color) {
721 			while (cnt--) {
722 			    a = scr_readw(q);
723 			    a ^= 0x0800;
724 			    scr_writew(a, q);
725 			    q++;
726 			}
727 		} else if (vc->vc_hi_font_mask == 0x100) {
728 			while (cnt--) {
729 				a = scr_readw(q);
730 				a = (a & 0x11ff) |
731 				   ((a & 0xe000) >> 4) |
732 				   ((a & 0x0e00) << 4);
733 				scr_writew(a, q);
734 				q++;
735 			}
736 		} else {
737 			while (cnt--) {
738 				a = scr_readw(q);
739 				a = (a & 0x88ff) |
740 				   ((a & 0x7000) >> 4) |
741 				   ((a & 0x0700) << 4);
742 				scr_writew(a, q);
743 				q++;
744 			}
745 		}
746 	}
747 
748 	if (con_should_update(vc))
749 		do_update_region(vc, (unsigned long) p, count);
750 	notify_update(vc);
751 }
752 
753 /* used by selection: complement pointer position */
754 void complement_pos(struct vc_data *vc, int offset)
755 {
756 	static int old_offset = -1;
757 	static unsigned short old;
758 	static unsigned short oldx, oldy;
759 
760 	WARN_CONSOLE_UNLOCKED();
761 
762 	if (old_offset != -1 && old_offset >= 0 &&
763 	    old_offset < vc->vc_screenbuf_size) {
764 		scr_writew(old, screenpos(vc, old_offset, true));
765 		if (con_should_update(vc))
766 			con_putc(vc, old, oldy, oldx);
767 		notify_update(vc);
768 	}
769 
770 	old_offset = offset;
771 
772 	if (offset != -1 && offset >= 0 &&
773 	    offset < vc->vc_screenbuf_size) {
774 		unsigned short new;
775 		u16 *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 			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 		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 			con_putc(vc, softcursor_original, vc->state.y,
845 				 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, false);
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, true);
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 (!con_is_visible(vc))
901 		return;
902 
903 	/*
904 	 * The legacy way for flushing the scrollback buffer is to use a side
905 	 * effect of the con_switch method. We do it only on the foreground
906 	 * console as background consoles have no scrollback buffers in that
907 	 * case and we obviously don't want to switch to them.
908 	 */
909 	hide_cursor(vc);
910 	vc->vc_sw->con_switch(vc);
911 	set_cursor(vc);
912 }
913 
914 /*
915  *	Redrawing of screen
916  */
917 
918 void clear_buffer_attributes(struct vc_data *vc)
919 {
920 	unsigned short *p = (unsigned short *)vc->vc_origin;
921 	int count = vc->vc_screenbuf_size / 2;
922 	int mask = vc->vc_hi_font_mask | 0xff;
923 
924 	for (; count > 0; count--, p++) {
925 		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
926 	}
927 }
928 
929 void redraw_screen(struct vc_data *vc, int is_switch)
930 {
931 	int redraw = 0;
932 
933 	WARN_CONSOLE_UNLOCKED();
934 
935 	if (!vc) {
936 		/* strange ... */
937 		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
938 		return;
939 	}
940 
941 	if (is_switch) {
942 		struct vc_data *old_vc = vc_cons[fg_console].d;
943 		if (old_vc == vc)
944 			return;
945 		if (!con_is_visible(vc))
946 			redraw = 1;
947 		*vc->vc_display_fg = vc;
948 		fg_console = vc->vc_num;
949 		hide_cursor(old_vc);
950 		if (!con_is_visible(old_vc)) {
951 			save_screen(old_vc);
952 			set_origin(old_vc);
953 		}
954 		if (tty0dev)
955 			sysfs_notify(&tty0dev->kobj, NULL, "active");
956 	} else {
957 		hide_cursor(vc);
958 		redraw = 1;
959 	}
960 
961 	if (redraw) {
962 		bool update;
963 		int old_was_color = vc->vc_can_do_color;
964 
965 		set_origin(vc);
966 		update = vc->vc_sw->con_switch(vc);
967 		set_palette(vc);
968 		/*
969 		 * If console changed from mono<->color, the best we can do
970 		 * is to clear the buffer attributes. As it currently stands,
971 		 * rebuilding new attributes from the old buffer is not doable
972 		 * without overly complex code.
973 		 */
974 		if (old_was_color != vc->vc_can_do_color) {
975 			update_attr(vc);
976 			clear_buffer_attributes(vc);
977 		}
978 
979 		if (update && vc->vc_mode != KD_GRAPHICS)
980 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
981 	}
982 	set_cursor(vc);
983 	if (is_switch) {
984 		vt_set_leds_compute_shiftstate();
985 		notify_update(vc);
986 	}
987 }
988 EXPORT_SYMBOL(redraw_screen);
989 
990 /*
991  *	Allocation, freeing and resizing of VTs.
992  */
993 
994 int vc_cons_allocated(unsigned int i)
995 {
996 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
997 }
998 
999 static void visual_init(struct vc_data *vc, int num, bool init)
1000 {
1001 	/* ++Geert: vc->vc_sw->con_init determines console size */
1002 	if (vc->vc_sw)
1003 		module_put(vc->vc_sw->owner);
1004 	vc->vc_sw = conswitchp;
1005 
1006 	if (con_driver_map[num])
1007 		vc->vc_sw = con_driver_map[num];
1008 
1009 	__module_get(vc->vc_sw->owner);
1010 	vc->vc_num = num;
1011 	vc->vc_display_fg = &master_display_fg;
1012 	if (vc->uni_pagedict_loc)
1013 		con_free_unimap(vc);
1014 	vc->uni_pagedict_loc = &vc->uni_pagedict;
1015 	vc->uni_pagedict = NULL;
1016 	vc->vc_hi_font_mask = 0;
1017 	vc->vc_complement_mask = 0;
1018 	vc->vc_can_do_color = 0;
1019 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1020 	vc->vc_sw->con_init(vc, init);
1021 	if (!vc->vc_complement_mask)
1022 		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1023 	vc->vc_s_complement_mask = vc->vc_complement_mask;
1024 	vc->vc_size_row = vc->vc_cols << 1;
1025 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1026 }
1027 
1028 
1029 static void visual_deinit(struct vc_data *vc)
1030 {
1031 	vc->vc_sw->con_deinit(vc);
1032 	module_put(vc->vc_sw->owner);
1033 }
1034 
1035 static void vc_port_destruct(struct tty_port *port)
1036 {
1037 	struct vc_data *vc = container_of(port, struct vc_data, port);
1038 
1039 	kfree(vc);
1040 }
1041 
1042 static const struct tty_port_operations vc_port_ops = {
1043 	.destruct = vc_port_destruct,
1044 };
1045 
1046 /*
1047  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1048  * [this is to be used together with some user program
1049  * like resize that changes the hardware videomode]
1050  */
1051 #define VC_MAXCOL (32767)
1052 #define VC_MAXROW (32767)
1053 
1054 int vc_allocate(unsigned int currcons)	/* return 0 on success */
1055 {
1056 	struct vt_notifier_param param;
1057 	struct vc_data *vc;
1058 	int err;
1059 
1060 	WARN_CONSOLE_UNLOCKED();
1061 
1062 	if (currcons >= MAX_NR_CONSOLES)
1063 		return -ENXIO;
1064 
1065 	if (vc_cons[currcons].d)
1066 		return 0;
1067 
1068 	/* due to the granularity of kmalloc, we waste some memory here */
1069 	/* the alloc is done in two steps, to optimize the common situation
1070 	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
1071 	/* although the numbers above are not valid since long ago, the
1072 	   point is still up-to-date and the comment still has its value
1073 	   even if only as a historical artifact.  --mj, July 1998 */
1074 	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1075 	if (!vc)
1076 		return -ENOMEM;
1077 
1078 	vc_cons[currcons].d = vc;
1079 	tty_port_init(&vc->port);
1080 	vc->port.ops = &vc_port_ops;
1081 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1082 
1083 	visual_init(vc, currcons, true);
1084 
1085 	if (!*vc->uni_pagedict_loc)
1086 		con_set_default_unimap(vc);
1087 
1088 	err = -EINVAL;
1089 	if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
1090 	    vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
1091 		goto err_free;
1092 	err = -ENOMEM;
1093 	vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1094 	if (!vc->vc_screenbuf)
1095 		goto err_free;
1096 
1097 	/* If no drivers have overridden us and the user didn't pass a
1098 	   boot option, default to displaying the cursor */
1099 	if (global_cursor_default == -1)
1100 		global_cursor_default = 1;
1101 
1102 	vc_init(vc, 1);
1103 	vcs_make_sysfs(currcons);
1104 	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1105 
1106 	return 0;
1107 err_free:
1108 	visual_deinit(vc);
1109 	kfree(vc);
1110 	vc_cons[currcons].d = NULL;
1111 	return err;
1112 }
1113 
1114 static inline int resize_screen(struct vc_data *vc, int width, int height,
1115 				bool from_user)
1116 {
1117 	/* Resizes the resolution of the display adapater */
1118 	int err = 0;
1119 
1120 	if (vc->vc_sw->con_resize)
1121 		err = vc->vc_sw->con_resize(vc, width, height, from_user);
1122 
1123 	return err;
1124 }
1125 
1126 /**
1127  * vc_do_resize - resizing method for the tty
1128  * @tty: tty being resized
1129  * @vc: virtual console private data
1130  * @cols: columns
1131  * @lines: lines
1132  * @from_user: invoked by a user?
1133  *
1134  * Resize a virtual console, clipping according to the actual constraints. If
1135  * the caller passes a tty structure then update the termios winsize
1136  * information and perform any necessary signal handling.
1137  *
1138  * Locking: Caller must hold the console semaphore. Takes the termios rwsem and
1139  * ctrl.lock of the tty IFF a tty is passed.
1140  */
1141 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1142 			unsigned int cols, unsigned int lines, bool from_user)
1143 {
1144 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1145 	unsigned long end;
1146 	unsigned int old_rows, old_row_size, first_copied_row;
1147 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1148 	unsigned short *oldscreen, *newscreen;
1149 	u32 **new_uniscr = NULL;
1150 
1151 	WARN_CONSOLE_UNLOCKED();
1152 
1153 	if (cols > VC_MAXCOL || lines > VC_MAXROW)
1154 		return -EINVAL;
1155 
1156 	new_cols = (cols ? cols : vc->vc_cols);
1157 	new_rows = (lines ? lines : vc->vc_rows);
1158 	new_row_size = new_cols << 1;
1159 	new_screen_size = new_row_size * new_rows;
1160 
1161 	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) {
1162 		/*
1163 		 * This function is being called here to cover the case
1164 		 * where the userspace calls the FBIOPUT_VSCREENINFO twice,
1165 		 * passing the same fb_var_screeninfo containing the fields
1166 		 * yres/xres equal to a number non-multiple of vc_font.height
1167 		 * and yres_virtual/xres_virtual equal to number lesser than the
1168 		 * vc_font.height and yres/xres.
1169 		 * In the second call, the struct fb_var_screeninfo isn't
1170 		 * being modified by the underlying driver because of the
1171 		 * if above, and this causes the fbcon_display->vrows to become
1172 		 * negative and it eventually leads to out-of-bound
1173 		 * access by the imageblit function.
1174 		 * To give the correct values to the struct and to not have
1175 		 * to deal with possible errors from the code below, we call
1176 		 * the resize_screen here as well.
1177 		 */
1178 		return resize_screen(vc, new_cols, new_rows, from_user);
1179 	}
1180 
1181 	if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
1182 		return -EINVAL;
1183 	newscreen = kzalloc(new_screen_size, GFP_USER);
1184 	if (!newscreen)
1185 		return -ENOMEM;
1186 
1187 	if (vc->vc_uni_lines) {
1188 		new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1189 		if (!new_uniscr) {
1190 			kfree(newscreen);
1191 			return -ENOMEM;
1192 		}
1193 	}
1194 
1195 	if (vc_is_sel(vc))
1196 		clear_selection();
1197 
1198 	old_rows = vc->vc_rows;
1199 	old_row_size = vc->vc_size_row;
1200 
1201 	err = resize_screen(vc, new_cols, new_rows, from_user);
1202 	if (err) {
1203 		kfree(newscreen);
1204 		vc_uniscr_free(new_uniscr);
1205 		return err;
1206 	}
1207 
1208 	vc->vc_rows = new_rows;
1209 	vc->vc_cols = new_cols;
1210 	vc->vc_size_row = new_row_size;
1211 	vc->vc_screenbuf_size = new_screen_size;
1212 
1213 	rlth = min(old_row_size, new_row_size);
1214 	rrem = new_row_size - rlth;
1215 	old_origin = vc->vc_origin;
1216 	new_origin = (long) newscreen;
1217 	new_scr_end = new_origin + new_screen_size;
1218 
1219 	if (vc->state.y > new_rows) {
1220 		if (old_rows - vc->state.y < new_rows) {
1221 			/*
1222 			 * Cursor near the bottom, copy contents from the
1223 			 * bottom of buffer
1224 			 */
1225 			first_copied_row = (old_rows - new_rows);
1226 		} else {
1227 			/*
1228 			 * Cursor is in no man's land, copy 1/2 screenful
1229 			 * from the top and bottom of cursor position
1230 			 */
1231 			first_copied_row = (vc->state.y - new_rows/2);
1232 		}
1233 		old_origin += first_copied_row * old_row_size;
1234 	} else
1235 		first_copied_row = 0;
1236 	end = old_origin + old_row_size * min(old_rows, new_rows);
1237 
1238 	vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1239 			    vc->vc_uni_lines, rlth/2, first_copied_row,
1240 			    min(old_rows, new_rows));
1241 	vc_uniscr_set(vc, new_uniscr);
1242 
1243 	update_attr(vc);
1244 
1245 	while (old_origin < end) {
1246 		scr_memcpyw((unsigned short *) new_origin,
1247 			    (unsigned short *) old_origin, rlth);
1248 		if (rrem)
1249 			scr_memsetw((void *)(new_origin + rlth),
1250 				    vc->vc_video_erase_char, rrem);
1251 		old_origin += old_row_size;
1252 		new_origin += new_row_size;
1253 	}
1254 	if (new_scr_end > new_origin)
1255 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1256 			    new_scr_end - new_origin);
1257 	oldscreen = vc->vc_screenbuf;
1258 	vc->vc_screenbuf = newscreen;
1259 	vc->vc_screenbuf_size = new_screen_size;
1260 	set_origin(vc);
1261 	kfree(oldscreen);
1262 
1263 	/* do part of a reset_terminal() */
1264 	vc->vc_top = 0;
1265 	vc->vc_bottom = vc->vc_rows;
1266 	gotoxy(vc, vc->state.x, vc->state.y);
1267 	save_cur(vc);
1268 
1269 	if (tty) {
1270 		/* Rewrite the requested winsize data with the actual
1271 		   resulting sizes */
1272 		struct winsize ws;
1273 		memset(&ws, 0, sizeof(ws));
1274 		ws.ws_row = vc->vc_rows;
1275 		ws.ws_col = vc->vc_cols;
1276 		ws.ws_ypixel = vc->vc_scan_lines;
1277 		tty_do_resize(tty, &ws);
1278 	}
1279 
1280 	if (con_is_visible(vc))
1281 		update_screen(vc);
1282 	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1283 	notify_update(vc);
1284 	return err;
1285 }
1286 
1287 /**
1288  * __vc_resize - resize a VT
1289  * @vc: virtual console
1290  * @cols: columns
1291  * @rows: rows
1292  * @from_user: invoked by a user?
1293  *
1294  * Resize a virtual console as seen from the console end of things. We use the
1295  * common vc_do_resize() method to update the structures.
1296  *
1297  * Locking: The caller must hold the console sem to protect console internals
1298  * and @vc->port.tty.
1299  */
1300 int __vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows,
1301 		bool from_user)
1302 {
1303 	return vc_do_resize(vc->port.tty, vc, cols, rows, from_user);
1304 }
1305 EXPORT_SYMBOL(__vc_resize);
1306 
1307 /**
1308  * vt_resize - resize a VT
1309  * @tty: tty to resize
1310  * @ws: winsize attributes
1311  *
1312  * Resize a virtual terminal. This is called by the tty layer as we register
1313  * our own handler for resizing. The mutual helper does all the actual work.
1314  *
1315  * Locking: Takes the console sem and the called methods then take the tty
1316  * termios_rwsem and the tty ctrl.lock in that order.
1317  */
1318 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1319 {
1320 	struct vc_data *vc = tty->driver_data;
1321 
1322 	guard(console_lock)();
1323 	return vc_do_resize(tty, vc, ws->ws_col, ws->ws_row, false);
1324 }
1325 
1326 struct vc_data *vc_deallocate(unsigned int currcons)
1327 {
1328 	struct vc_data *vc = NULL;
1329 
1330 	WARN_CONSOLE_UNLOCKED();
1331 
1332 	if (vc_cons_allocated(currcons)) {
1333 		struct vt_notifier_param param;
1334 
1335 		param.vc = vc = vc_cons[currcons].d;
1336 		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1337 		vcs_remove_sysfs(currcons);
1338 		visual_deinit(vc);
1339 		con_free_unimap(vc);
1340 		put_pid(vc->vt_pid);
1341 		vc_uniscr_set(vc, NULL);
1342 		kfree(vc->vc_screenbuf);
1343 		vc_cons[currcons].d = NULL;
1344 		if (vc->vc_saved_screen != NULL) {
1345 			kfree(vc->vc_saved_screen);
1346 			vc->vc_saved_screen = NULL;
1347 		}
1348 	}
1349 	return vc;
1350 }
1351 
1352 /*
1353  *	VT102 emulator
1354  */
1355 
1356 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1357 
1358 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1359 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1360 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1361 
1362 #define decarm		VC_REPEAT
1363 #define decckm		VC_CKMODE
1364 #define kbdapplic	VC_APPLIC
1365 #define lnm		VC_CRLF
1366 
1367 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1368 				       8,12,10,14, 9,13,11,15 };
1369 EXPORT_SYMBOL(color_table);
1370 
1371 /* the default colour table, for VGA+ colour systems */
1372 unsigned char default_red[] = {
1373 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1374 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1375 };
1376 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1377 EXPORT_SYMBOL(default_red);
1378 
1379 unsigned char default_grn[] = {
1380 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1381 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1382 };
1383 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1384 EXPORT_SYMBOL(default_grn);
1385 
1386 unsigned char default_blu[] = {
1387 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1388 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1389 };
1390 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1391 EXPORT_SYMBOL(default_blu);
1392 
1393 /*
1394  * gotoxy() must verify all boundaries, because the arguments
1395  * might also be negative. If the given position is out of
1396  * bounds, the cursor is placed at the nearest margin.
1397  */
1398 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1399 {
1400 	int min_y, max_y;
1401 
1402 	if (new_x < 0)
1403 		vc->state.x = 0;
1404 	else {
1405 		if (new_x >= vc->vc_cols)
1406 			vc->state.x = vc->vc_cols - 1;
1407 		else
1408 			vc->state.x = new_x;
1409 	}
1410 
1411  	if (vc->vc_decom) {
1412 		min_y = vc->vc_top;
1413 		max_y = vc->vc_bottom;
1414 	} else {
1415 		min_y = 0;
1416 		max_y = vc->vc_rows;
1417 	}
1418 	if (new_y < min_y)
1419 		vc->state.y = min_y;
1420 	else if (new_y >= max_y)
1421 		vc->state.y = max_y - 1;
1422 	else
1423 		vc->state.y = new_y;
1424 	vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
1425 		(vc->state.x << 1);
1426 	vc->vc_need_wrap = 0;
1427 }
1428 
1429 /* for absolute user moves, when decom is set */
1430 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1431 {
1432 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1433 }
1434 
1435 void scrollback(struct vc_data *vc)
1436 {
1437 	scrolldelta(-(vc->vc_rows / 2));
1438 }
1439 
1440 void scrollfront(struct vc_data *vc, int lines)
1441 {
1442 	if (!lines)
1443 		lines = vc->vc_rows / 2;
1444 	scrolldelta(lines);
1445 }
1446 
1447 static void lf(struct vc_data *vc)
1448 {
1449     	/* don't scroll if above bottom of scrolling region, or
1450 	 * if below scrolling region
1451 	 */
1452 	if (vc->state.y + 1 == vc->vc_bottom)
1453 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1454 	else if (vc->state.y < vc->vc_rows - 1) {
1455 		vc->state.y++;
1456 		vc->vc_pos += vc->vc_size_row;
1457 	}
1458 	vc->vc_need_wrap = 0;
1459 	notify_write(vc, '\n');
1460 }
1461 
1462 static void ri(struct vc_data *vc)
1463 {
1464     	/* don't scroll if below top of scrolling region, or
1465 	 * if above scrolling region
1466 	 */
1467 	if (vc->state.y == vc->vc_top)
1468 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1469 	else if (vc->state.y > 0) {
1470 		vc->state.y--;
1471 		vc->vc_pos -= vc->vc_size_row;
1472 	}
1473 	vc->vc_need_wrap = 0;
1474 }
1475 
1476 static inline void cr(struct vc_data *vc)
1477 {
1478 	vc->vc_pos -= vc->state.x << 1;
1479 	vc->vc_need_wrap = vc->state.x = 0;
1480 	notify_write(vc, '\r');
1481 }
1482 
1483 static inline void bs(struct vc_data *vc)
1484 {
1485 	if (vc->state.x) {
1486 		vc->vc_pos -= 2;
1487 		vc->state.x--;
1488 		vc->vc_need_wrap = 0;
1489 		notify_write(vc, '\b');
1490 	}
1491 }
1492 
1493 static inline void del(struct vc_data *vc)
1494 {
1495 	/* ignored */
1496 }
1497 
1498 enum CSI_J {
1499 	CSI_J_CURSOR_TO_END	= 0,
1500 	CSI_J_START_TO_CURSOR	= 1,
1501 	CSI_J_VISIBLE		= 2,
1502 	CSI_J_FULL		= 3,
1503 };
1504 
1505 static void csi_J(struct vc_data *vc, enum CSI_J vpar)
1506 {
1507 	unsigned short *start;
1508 	unsigned int count;
1509 
1510 	switch (vpar) {
1511 	case CSI_J_CURSOR_TO_END:
1512 		vc_uniscr_clear_line(vc, vc->state.x,
1513 				     vc->vc_cols - vc->state.x);
1514 		vc_uniscr_clear_lines(vc, vc->state.y + 1,
1515 				      vc->vc_rows - vc->state.y - 1);
1516 		count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1517 		start = (unsigned short *)vc->vc_pos;
1518 		break;
1519 	case CSI_J_START_TO_CURSOR:
1520 		vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
1521 		vc_uniscr_clear_lines(vc, 0, vc->state.y);
1522 		count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1523 		start = (unsigned short *)vc->vc_origin;
1524 		break;
1525 	case CSI_J_FULL:
1526 		flush_scrollback(vc);
1527 		fallthrough;
1528 	case CSI_J_VISIBLE:
1529 		vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1530 		count = vc->vc_cols * vc->vc_rows;
1531 		start = (unsigned short *)vc->vc_origin;
1532 		break;
1533 	default:
1534 		return;
1535 	}
1536 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1537 	if (con_should_update(vc))
1538 		do_update_region(vc, (unsigned long) start, count);
1539 	vc->vc_need_wrap = 0;
1540 }
1541 
1542 enum {
1543 	CSI_K_CURSOR_TO_LINEEND		= 0,
1544 	CSI_K_LINESTART_TO_CURSOR	= 1,
1545 	CSI_K_LINE			= 2,
1546 };
1547 
1548 static void csi_K(struct vc_data *vc)
1549 {
1550 	unsigned int count;
1551 	unsigned short *start = (unsigned short *)vc->vc_pos;
1552 	int offset;
1553 
1554 	switch (vc->vc_par[0]) {
1555 	case CSI_K_CURSOR_TO_LINEEND:
1556 		offset = 0;
1557 		count = vc->vc_cols - vc->state.x;
1558 		break;
1559 	case CSI_K_LINESTART_TO_CURSOR:
1560 		offset = -vc->state.x;
1561 		count = vc->state.x + 1;
1562 		break;
1563 	case CSI_K_LINE:
1564 		offset = -vc->state.x;
1565 		count = vc->vc_cols;
1566 		break;
1567 	default:
1568 		return;
1569 	}
1570 	vc_uniscr_clear_line(vc, vc->state.x + offset, count);
1571 	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1572 	vc->vc_need_wrap = 0;
1573 	if (con_should_update(vc))
1574 		do_update_region(vc, (unsigned long)(start + offset), count);
1575 }
1576 
1577 /* erase the following count positions */
1578 static void csi_X(struct vc_data *vc)
1579 {					  /* not vt100? */
1580 	unsigned int count = clamp(vc->vc_par[0], 1, 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, 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(unsigned 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 		i -= 16;
1613 		c->b = i % 6 * 255 / 6;
1614 		i /= 6;
1615 		c->g = i % 6 * 255 / 6;
1616 		i /= 6;
1617 		c->r = i     * 255 / 6;
1618 	} else                  /* Grayscale ramp. */
1619 		c->r = c->g = c->b = i * 10 - 2312;
1620 }
1621 
1622 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1623 {
1624 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1625 
1626 	if (c->r > max / 2)
1627 		hue |= 4;
1628 	if (c->g > max / 2)
1629 		hue |= 2;
1630 	if (c->b > max / 2)
1631 		hue |= 1;
1632 
1633 	if (hue == 7 && max <= 0x55) {
1634 		hue = 0;
1635 		vc->state.intensity = VCI_BOLD;
1636 	} else if (max > 0xaa)
1637 		vc->state.intensity = VCI_BOLD;
1638 	else
1639 		vc->state.intensity = VCI_NORMAL;
1640 
1641 	vc->state.color = (vc->state.color & 0xf0) | hue;
1642 }
1643 
1644 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1645 {
1646 	/* For backgrounds, err on the dark side. */
1647 	vc->state.color = (vc->state.color & 0x0f)
1648 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1649 }
1650 
1651 /*
1652  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1653  * and thus need to be detected and ignored by hand. That standard also
1654  * wants : rather than ; as separators but sequences containing : are currently
1655  * completely ignored by the parser.
1656  *
1657  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1658  * supporting them.
1659  */
1660 static int vc_t416_color(struct vc_data *vc, int i,
1661 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1662 {
1663 	struct rgb c;
1664 
1665 	i++;
1666 	if (i > vc->vc_npar)
1667 		return i;
1668 
1669 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1670 		/* 256 colours */
1671 		i++;
1672 		rgb_from_256(vc->vc_par[i], &c);
1673 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1674 		/* 24 bit */
1675 		c.r = vc->vc_par[i + 1];
1676 		c.g = vc->vc_par[i + 2];
1677 		c.b = vc->vc_par[i + 3];
1678 		i += 3;
1679 	} else
1680 		return i;
1681 
1682 	set_color(vc, &c);
1683 
1684 	return i;
1685 }
1686 
1687 enum {
1688 	CSI_m_DEFAULT			= 0,
1689 	CSI_m_BOLD			= 1,
1690 	CSI_m_HALF_BRIGHT		= 2,
1691 	CSI_m_ITALIC			= 3,
1692 	CSI_m_UNDERLINE			= 4,
1693 	CSI_m_BLINK			= 5,
1694 	CSI_m_REVERSE			= 7,
1695 	CSI_m_PRI_FONT			= 10,
1696 	CSI_m_ALT_FONT1			= 11,
1697 	CSI_m_ALT_FONT2			= 12,
1698 	CSI_m_DOUBLE_UNDERLINE		= 21,
1699 	CSI_m_NORMAL_INTENSITY		= 22,
1700 	CSI_m_NO_ITALIC			= 23,
1701 	CSI_m_NO_UNDERLINE		= 24,
1702 	CSI_m_NO_BLINK			= 25,
1703 	CSI_m_NO_REVERSE		= 27,
1704 	CSI_m_FG_COLOR_BEG		= 30,
1705 	CSI_m_FG_COLOR_END		= 37,
1706 	CSI_m_FG_COLOR			= 38,
1707 	CSI_m_DEFAULT_FG_COLOR		= 39,
1708 	CSI_m_BG_COLOR_BEG		= 40,
1709 	CSI_m_BG_COLOR_END		= 47,
1710 	CSI_m_BG_COLOR			= 48,
1711 	CSI_m_DEFAULT_BG_COLOR		= 49,
1712 	CSI_m_BRIGHT_FG_COLOR_BEG	= 90,
1713 	CSI_m_BRIGHT_FG_COLOR_END	= 97,
1714 	CSI_m_BRIGHT_FG_COLOR_OFF	= CSI_m_BRIGHT_FG_COLOR_BEG - CSI_m_FG_COLOR_BEG,
1715 	CSI_m_BRIGHT_BG_COLOR_BEG	= 100,
1716 	CSI_m_BRIGHT_BG_COLOR_END	= 107,
1717 	CSI_m_BRIGHT_BG_COLOR_OFF	= CSI_m_BRIGHT_BG_COLOR_BEG - CSI_m_BG_COLOR_BEG,
1718 };
1719 
1720 /* console_lock is held */
1721 static void csi_m(struct vc_data *vc)
1722 {
1723 	int i;
1724 
1725 	for (i = 0; i <= vc->vc_npar; i++)
1726 		switch (vc->vc_par[i]) {
1727 		case CSI_m_DEFAULT:	/* all attributes off */
1728 			default_attr(vc);
1729 			break;
1730 		case CSI_m_BOLD:
1731 			vc->state.intensity = VCI_BOLD;
1732 			break;
1733 		case CSI_m_HALF_BRIGHT:
1734 			vc->state.intensity = VCI_HALF_BRIGHT;
1735 			break;
1736 		case CSI_m_ITALIC:
1737 			vc->state.italic = true;
1738 			break;
1739 		case CSI_m_DOUBLE_UNDERLINE:
1740 			/*
1741 			 * No console drivers support double underline, so
1742 			 * convert it to a single underline.
1743 			 */
1744 		case CSI_m_UNDERLINE:
1745 			vc->state.underline = true;
1746 			break;
1747 		case CSI_m_BLINK:
1748 			vc->state.blink = true;
1749 			break;
1750 		case CSI_m_REVERSE:
1751 			vc->state.reverse = true;
1752 			break;
1753 		case CSI_m_PRI_FONT: /* ANSI X3.64-1979 (SCO-ish?)
1754 			  * Select primary font, don't display control chars if
1755 			  * defined, don't set bit 8 on output.
1756 			  */
1757 			vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset], vc);
1758 			vc->vc_disp_ctrl = 0;
1759 			vc->vc_toggle_meta = 0;
1760 			break;
1761 		case CSI_m_ALT_FONT1: /* ANSI X3.64-1979 (SCO-ish?)
1762 			  * Select first alternate font, lets chars < 32 be
1763 			  * displayed as ROM chars.
1764 			  */
1765 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1766 			vc->vc_disp_ctrl = 1;
1767 			vc->vc_toggle_meta = 0;
1768 			break;
1769 		case CSI_m_ALT_FONT2: /* ANSI X3.64-1979 (SCO-ish?)
1770 			  * Select second alternate font, toggle high bit
1771 			  * before displaying as ROM char.
1772 			  */
1773 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1774 			vc->vc_disp_ctrl = 1;
1775 			vc->vc_toggle_meta = 1;
1776 			break;
1777 		case CSI_m_NORMAL_INTENSITY:
1778 			vc->state.intensity = VCI_NORMAL;
1779 			break;
1780 		case CSI_m_NO_ITALIC:
1781 			vc->state.italic = false;
1782 			break;
1783 		case CSI_m_NO_UNDERLINE:
1784 			vc->state.underline = false;
1785 			break;
1786 		case CSI_m_NO_BLINK:
1787 			vc->state.blink = false;
1788 			break;
1789 		case CSI_m_NO_REVERSE:
1790 			vc->state.reverse = false;
1791 			break;
1792 		case CSI_m_FG_COLOR:
1793 			i = vc_t416_color(vc, i, rgb_foreground);
1794 			break;
1795 		case CSI_m_BG_COLOR:
1796 			i = vc_t416_color(vc, i, rgb_background);
1797 			break;
1798 		case CSI_m_DEFAULT_FG_COLOR:
1799 			vc->state.color = (vc->vc_def_color & 0x0f) |
1800 				(vc->state.color & 0xf0);
1801 			break;
1802 		case CSI_m_DEFAULT_BG_COLOR:
1803 			vc->state.color = (vc->vc_def_color & 0xf0) |
1804 				(vc->state.color & 0x0f);
1805 			break;
1806 		case CSI_m_BRIGHT_FG_COLOR_BEG ... CSI_m_BRIGHT_FG_COLOR_END:
1807 			vc->state.intensity = VCI_BOLD;
1808 			vc->vc_par[i] -= CSI_m_BRIGHT_FG_COLOR_OFF;
1809 			fallthrough;
1810 		case CSI_m_FG_COLOR_BEG ... CSI_m_FG_COLOR_END:
1811 			vc->vc_par[i] -= CSI_m_FG_COLOR_BEG;
1812 			vc->state.color = color_table[vc->vc_par[i]] |
1813 				(vc->state.color & 0xf0);
1814 			break;
1815 		case CSI_m_BRIGHT_BG_COLOR_BEG ... CSI_m_BRIGHT_BG_COLOR_END:
1816 			vc->vc_par[i] -= CSI_m_BRIGHT_BG_COLOR_OFF;
1817 			fallthrough;
1818 		case CSI_m_BG_COLOR_BEG ... CSI_m_BG_COLOR_END:
1819 			vc->vc_par[i] -= CSI_m_BG_COLOR_BEG;
1820 			vc->state.color = (color_table[vc->vc_par[i]] << 4) |
1821 				(vc->state.color & 0x0f);
1822 			break;
1823 		}
1824 	update_attr(vc);
1825 }
1826 
1827 static void respond_string(const char *p, size_t len, struct tty_port *port)
1828 {
1829 	tty_insert_flip_string(port, p, len);
1830 	tty_flip_buffer_push(port);
1831 }
1832 
1833 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1834 {
1835 	char buf[40];
1836 	int len;
1837 
1838 	len = sprintf(buf, "\033[%d;%dR", vc->state.y +
1839 			(vc->vc_decom ? vc->vc_top + 1 : 1),
1840 			vc->state.x + 1);
1841 	respond_string(buf, len, tty->port);
1842 }
1843 
1844 static inline void status_report(struct tty_struct *tty)
1845 {
1846 	static const char teminal_ok[] = "\033[0n";
1847 
1848 	respond_string(teminal_ok, strlen(teminal_ok), tty->port);
1849 }
1850 
1851 static inline void respond_ID(struct tty_struct *tty)
1852 {
1853 	/* terminal answer to an ESC-Z or csi0c query. */
1854 	static const char vt102_id[] = "\033[?6c";
1855 
1856 	respond_string(vt102_id, strlen(vt102_id), tty->port);
1857 }
1858 
1859 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1860 {
1861 	char buf[8];
1862 	int len;
1863 
1864 	len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
1865 			(char)('!' + mrx), (char)('!' + mry));
1866 	respond_string(buf, len, tty->port);
1867 }
1868 
1869 /* invoked via ioctl(TIOCLINUX) and through set_selection_user */
1870 int mouse_reporting(void)
1871 {
1872 	return vc_cons[fg_console].d->vc_report_mouse;
1873 }
1874 
1875 /* invoked via ioctl(TIOCLINUX) */
1876 static int get_bracketed_paste(struct tty_struct *tty)
1877 {
1878 	struct vc_data *vc = tty->driver_data;
1879 
1880 	return vc->vc_bracketed_paste;
1881 }
1882 
1883 /* console_lock is held */
1884 static void enter_alt_screen(struct vc_data *vc)
1885 {
1886 	unsigned int size = vc->vc_rows * vc->vc_cols * 2;
1887 
1888 	if (vc->vc_saved_screen != NULL)
1889 		return; /* Already inside an alt-screen */
1890 	vc->vc_saved_screen = kmemdup((u16 *)vc->vc_origin, size, GFP_KERNEL);
1891 	if (vc->vc_saved_screen == NULL)
1892 		return;
1893 	vc->vc_saved_rows = vc->vc_rows;
1894 	vc->vc_saved_cols = vc->vc_cols;
1895 	save_cur(vc);
1896 	/* clear entire screen */
1897 	csi_J(vc, CSI_J_FULL);
1898 }
1899 
1900 /* console_lock is held */
1901 static void leave_alt_screen(struct vc_data *vc)
1902 {
1903 	unsigned int rows = min(vc->vc_saved_rows, vc->vc_rows);
1904 	unsigned int cols = min(vc->vc_saved_cols, vc->vc_cols);
1905 	u16 *src, *dest;
1906 
1907 	if (vc->vc_saved_screen == NULL)
1908 		return; /* Not inside an alt-screen */
1909 	for (unsigned int r = 0; r < rows; r++) {
1910 		src = vc->vc_saved_screen + r * vc->vc_saved_cols;
1911 		dest = ((u16 *)vc->vc_origin) + r * vc->vc_cols;
1912 		memcpy(dest, src, 2 * cols);
1913 	}
1914 	restore_cur(vc);
1915 	/* Update the entire screen */
1916 	if (con_should_update(vc))
1917 		do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1918 	kfree(vc->vc_saved_screen);
1919 	vc->vc_saved_screen = NULL;
1920 }
1921 
1922 enum {
1923 	CSI_DEC_hl_CURSOR_KEYS	= 1,	/* CKM: cursor keys send ^[Ox/^[[x */
1924 	CSI_DEC_hl_132_COLUMNS	= 3,	/* COLM: 80/132 mode switch */
1925 	CSI_DEC_hl_REVERSE_VIDEO = 5,	/* SCNM */
1926 	CSI_DEC_hl_ORIGIN_MODE	= 6,	/* OM: origin relative/absolute */
1927 	CSI_DEC_hl_AUTOWRAP	= 7,	/* AWM */
1928 	CSI_DEC_hl_AUTOREPEAT	= 8,	/* ARM */
1929 	CSI_DEC_hl_MOUSE_X10	= 9,
1930 	CSI_DEC_hl_SHOW_CURSOR	= 25,	/* TCEM */
1931 	CSI_DEC_hl_MOUSE_VT200	= 1000,
1932 	CSI_DEC_hl_ALT_SCREEN	= 1049,
1933 	CSI_DEC_hl_BRACKETED_PASTE = 2004,
1934 };
1935 
1936 /* console_lock is held */
1937 static void csi_DEC_hl(struct vc_data *vc, bool on_off)
1938 {
1939 	unsigned int i;
1940 
1941 	for (i = 0; i <= vc->vc_npar; i++)
1942 		switch (vc->vc_par[i]) {
1943 		case CSI_DEC_hl_CURSOR_KEYS:
1944 			if (on_off)
1945 				set_kbd(vc, decckm);
1946 			else
1947 				clr_kbd(vc, decckm);
1948 			break;
1949 		case CSI_DEC_hl_132_COLUMNS:	/* unimplemented */
1950 #if 0
1951 			vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1952 			/* this alone does not suffice; some user mode
1953 			   utility has to change the hardware regs */
1954 #endif
1955 			break;
1956 		case CSI_DEC_hl_REVERSE_VIDEO:
1957 			if (vc->vc_decscnm != on_off) {
1958 				vc->vc_decscnm = on_off;
1959 				invert_screen(vc, 0, vc->vc_screenbuf_size,
1960 					      false);
1961 				update_attr(vc);
1962 			}
1963 			break;
1964 		case CSI_DEC_hl_ORIGIN_MODE:
1965 			vc->vc_decom = on_off;
1966 			gotoxay(vc, 0, 0);
1967 			break;
1968 		case CSI_DEC_hl_AUTOWRAP:
1969 			vc->vc_decawm = on_off;
1970 			break;
1971 		case CSI_DEC_hl_AUTOREPEAT:
1972 			if (on_off)
1973 				set_kbd(vc, decarm);
1974 			else
1975 				clr_kbd(vc, decarm);
1976 			break;
1977 		case CSI_DEC_hl_MOUSE_X10:
1978 			vc->vc_report_mouse = on_off ? 1 : 0;
1979 			break;
1980 		case CSI_DEC_hl_SHOW_CURSOR:
1981 			vc->vc_deccm = on_off;
1982 			break;
1983 		case CSI_DEC_hl_MOUSE_VT200:
1984 			vc->vc_report_mouse = on_off ? 2 : 0;
1985 			break;
1986 		case CSI_DEC_hl_BRACKETED_PASTE:
1987 			vc->vc_bracketed_paste = on_off;
1988 			break;
1989 		case CSI_DEC_hl_ALT_SCREEN:
1990 			if (on_off)
1991 				enter_alt_screen(vc);
1992 			else
1993 				leave_alt_screen(vc);
1994 			break;
1995 		}
1996 }
1997 
1998 enum {
1999 	CSI_hl_DISPLAY_CTRL	= 3,	/* handle ansi control chars */
2000 	CSI_hl_INSERT		= 4,	/* IRM: insert/replace */
2001 	CSI_hl_AUTO_NL		= 20,	/* LNM: Enter == CrLf/Lf */
2002 };
2003 
2004 /* console_lock is held */
2005 static void csi_hl(struct vc_data *vc, bool on_off)
2006 {
2007 	unsigned int i;
2008 
2009 	for (i = 0; i <= vc->vc_npar; i++)
2010 		switch (vc->vc_par[i]) {	/* ANSI modes set/reset */
2011 		case CSI_hl_DISPLAY_CTRL:
2012 			vc->vc_disp_ctrl = on_off;
2013 			break;
2014 		case CSI_hl_INSERT:
2015 			vc->vc_decim = on_off;
2016 			break;
2017 		case CSI_hl_AUTO_NL:
2018 			if (on_off)
2019 				set_kbd(vc, lnm);
2020 			else
2021 				clr_kbd(vc, lnm);
2022 			break;
2023 		}
2024 }
2025 
2026 enum CSI_right_square_bracket {
2027 	CSI_RSB_COLOR_FOR_UNDERLINE		= 1,
2028 	CSI_RSB_COLOR_FOR_HALF_BRIGHT		= 2,
2029 	CSI_RSB_MAKE_CUR_COLOR_DEFAULT		= 8,
2030 	CSI_RSB_BLANKING_INTERVAL		= 9,
2031 	CSI_RSB_BELL_FREQUENCY			= 10,
2032 	CSI_RSB_BELL_DURATION			= 11,
2033 	CSI_RSB_BRING_CONSOLE_TO_FRONT		= 12,
2034 	CSI_RSB_UNBLANK				= 13,
2035 	CSI_RSB_VESA_OFF_INTERVAL		= 14,
2036 	CSI_RSB_BRING_PREV_CONSOLE_TO_FRONT	= 15,
2037 	CSI_RSB_CURSOR_BLINK_INTERVAL		= 16,
2038 };
2039 
2040 /*
2041  * csi_RSB - csi+] (Right Square Bracket) handler
2042  *
2043  * These are linux console private sequences.
2044  *
2045  * console_lock is held
2046  */
2047 static void csi_RSB(struct vc_data *vc)
2048 {
2049 	switch (vc->vc_par[0]) {
2050 	case CSI_RSB_COLOR_FOR_UNDERLINE:
2051 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
2052 			vc->vc_ulcolor = color_table[vc->vc_par[1]];
2053 			if (vc->state.underline)
2054 				update_attr(vc);
2055 		}
2056 		break;
2057 	case CSI_RSB_COLOR_FOR_HALF_BRIGHT:
2058 		if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
2059 			vc->vc_halfcolor = color_table[vc->vc_par[1]];
2060 			if (vc->state.intensity == VCI_HALF_BRIGHT)
2061 				update_attr(vc);
2062 		}
2063 		break;
2064 	case CSI_RSB_MAKE_CUR_COLOR_DEFAULT:
2065 		vc->vc_def_color = vc->vc_attr;
2066 		if (vc->vc_hi_font_mask == 0x100)
2067 			vc->vc_def_color >>= 1;
2068 		default_attr(vc);
2069 		update_attr(vc);
2070 		break;
2071 	case CSI_RSB_BLANKING_INTERVAL:
2072 		blankinterval = min(vc->vc_par[1], 60U) * 60;
2073 		poke_blanked_console();
2074 		break;
2075 	case CSI_RSB_BELL_FREQUENCY:
2076 		if (vc->vc_npar >= 1)
2077 			vc->vc_bell_pitch = vc->vc_par[1];
2078 		else
2079 			vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2080 		break;
2081 	case CSI_RSB_BELL_DURATION:
2082 		if (vc->vc_npar >= 1)
2083 			vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
2084 				msecs_to_jiffies(vc->vc_par[1]) : 0;
2085 		else
2086 			vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2087 		break;
2088 	case CSI_RSB_BRING_CONSOLE_TO_FRONT:
2089 		if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
2090 			set_console(vc->vc_par[1] - 1);
2091 		break;
2092 	case CSI_RSB_UNBLANK:
2093 		poke_blanked_console();
2094 		break;
2095 	case CSI_RSB_VESA_OFF_INTERVAL:
2096 		vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
2097 		break;
2098 	case CSI_RSB_BRING_PREV_CONSOLE_TO_FRONT:
2099 		set_console(last_console);
2100 		break;
2101 	case CSI_RSB_CURSOR_BLINK_INTERVAL:
2102 		if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
2103 				vc->vc_par[1] <= USHRT_MAX)
2104 			vc->vc_cur_blink_ms = vc->vc_par[1];
2105 		else
2106 			vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2107 		break;
2108 	}
2109 }
2110 
2111 /* console_lock is held */
2112 static void csi_at(struct vc_data *vc, unsigned int nr)
2113 {
2114 	nr = clamp(nr, 1, vc->vc_cols - vc->state.x);
2115 	insert_char(vc, nr);
2116 }
2117 
2118 /* console_lock is held */
2119 static void csi_L(struct vc_data *vc)
2120 {
2121 	unsigned int nr = clamp(vc->vc_par[0], 1, vc->vc_rows - vc->state.y);
2122 
2123 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
2124 	vc->vc_need_wrap = 0;
2125 }
2126 
2127 /* console_lock is held */
2128 static void csi_P(struct vc_data *vc)
2129 {
2130 	unsigned int nr = clamp(vc->vc_par[0], 1, vc->vc_cols - vc->state.x);
2131 
2132 	delete_char(vc, nr);
2133 }
2134 
2135 /* console_lock is held */
2136 static void csi_M(struct vc_data *vc)
2137 {
2138 	unsigned int nr = clamp(vc->vc_par[0], 1, vc->vc_rows - vc->state.y);
2139 
2140 	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
2141 	vc->vc_need_wrap = 0;
2142 }
2143 
2144 /* console_lock is held (except via vc_init->reset_terminal */
2145 static void save_cur(struct vc_data *vc)
2146 {
2147 	memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
2148 }
2149 
2150 /* console_lock is held */
2151 static void restore_cur(struct vc_data *vc)
2152 {
2153 	memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
2154 
2155 	gotoxy(vc, vc->state.x, vc->state.y);
2156 	vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
2157 			vc);
2158 	update_attr(vc);
2159 	vc->vc_need_wrap = 0;
2160 }
2161 
2162 /**
2163  * enum vc_ctl_state - control characters state of a vt
2164  *
2165  * @ESnormal:		initial state, no control characters parsed
2166  * @ESesc:		ESC parsed
2167  * @ESsquare:		CSI parsed -- modifiers/parameters/ctrl chars expected
2168  * @ESgetpars:		CSI parsed -- parameters/ctrl chars expected
2169  * @ESfunckey:		CSI [ parsed
2170  * @EShash:		ESC # parsed
2171  * @ESsetG0:		ESC ( parsed
2172  * @ESsetG1:		ESC ) parsed
2173  * @ESpercent:		ESC % parsed
2174  * @EScsiignore:	CSI [0x20-0x3f] parsed
2175  * @ESnonstd:		OSC parsed
2176  * @ESpalette:		OSC P parsed
2177  * @ESosc:		OSC [0-9] parsed
2178  * @ESANSI_first:	first state for ignoring ansi control sequences
2179  * @ESapc:		ESC _ parsed
2180  * @ESpm:		ESC ^ parsed
2181  * @ESdcs:		ESC P parsed
2182  * @ESANSI_last:	last state for ignoring ansi control sequences
2183  */
2184 enum vc_ctl_state {
2185 	ESnormal,
2186 	ESesc,
2187 	ESsquare,
2188 	ESgetpars,
2189 	ESfunckey,
2190 	EShash,
2191 	ESsetG0,
2192 	ESsetG1,
2193 	ESpercent,
2194 	EScsiignore,
2195 	ESnonstd,
2196 	ESpalette,
2197 	ESosc,
2198 	ESANSI_first = ESosc,
2199 	ESapc,
2200 	ESpm,
2201 	ESdcs,
2202 	ESANSI_last = ESdcs,
2203 };
2204 
2205 /* console_lock is held (except via vc_init()) */
2206 static void reset_terminal(struct vc_data *vc, int do_clear)
2207 {
2208 	unsigned int i;
2209 
2210 	vc->vc_top		= 0;
2211 	vc->vc_bottom		= vc->vc_rows;
2212 	vc->vc_state		= ESnormal;
2213 	vc->vc_priv		= EPecma;
2214 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
2215 	vc->state.Gx_charset[0]	= LAT1_MAP;
2216 	vc->state.Gx_charset[1]	= GRAF_MAP;
2217 	vc->state.charset	= 0;
2218 	vc->vc_need_wrap	= 0;
2219 	vc->vc_report_mouse	= 0;
2220 	vc->vc_bracketed_paste	= 0;
2221 	vc->vc_utf              = default_utf8;
2222 	vc->vc_utf_count	= 0;
2223 
2224 	vc->vc_disp_ctrl	= 0;
2225 	vc->vc_toggle_meta	= 0;
2226 
2227 	vc->vc_decscnm		= 0;
2228 	vc->vc_decom		= 0;
2229 	vc->vc_decawm		= 1;
2230 	vc->vc_deccm		= global_cursor_default;
2231 	vc->vc_decim		= 0;
2232 
2233 	if (vc->vc_saved_screen != NULL) {
2234 		kfree(vc->vc_saved_screen);
2235 		vc->vc_saved_screen = NULL;
2236 		vc->vc_saved_rows = 0;
2237 		vc->vc_saved_cols = 0;
2238 	}
2239 
2240 	vt_reset_keyboard(vc->vc_num);
2241 
2242 	vc->vc_cursor_type = cur_default;
2243 	vc->vc_complement_mask = vc->vc_s_complement_mask;
2244 
2245 	default_attr(vc);
2246 	update_attr(vc);
2247 
2248 	bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2249 	for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
2250 		set_bit(i, vc->vc_tab_stop);
2251 
2252 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2253 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2254 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2255 
2256 	gotoxy(vc, 0, 0);
2257 	save_cur(vc);
2258 	if (do_clear)
2259 	    csi_J(vc, CSI_J_VISIBLE);
2260 }
2261 
2262 static void vc_setGx(struct vc_data *vc, unsigned int which, u8 c)
2263 {
2264 	unsigned char *charset = &vc->state.Gx_charset[which];
2265 
2266 	switch (c) {
2267 	case '0':
2268 		*charset = GRAF_MAP;
2269 		break;
2270 	case 'B':
2271 		*charset = LAT1_MAP;
2272 		break;
2273 	case 'U':
2274 		*charset = IBMPC_MAP;
2275 		break;
2276 	case 'K':
2277 		*charset = USER_MAP;
2278 		break;
2279 	}
2280 
2281 	if (vc->state.charset == which)
2282 		vc->vc_translate = set_translate(*charset, vc);
2283 }
2284 
2285 static bool ansi_control_string(enum vc_ctl_state state)
2286 {
2287 	return state >= ESANSI_first && state <= ESANSI_last;
2288 }
2289 
2290 enum {
2291 	ASCII_NULL		= 0,
2292 	ASCII_BELL		= 7,
2293 	ASCII_BACKSPACE		= 8,
2294 	ASCII_IGNORE_FIRST	= ASCII_BACKSPACE,
2295 	ASCII_HTAB		= 9,
2296 	ASCII_LINEFEED		= 10,
2297 	ASCII_VTAB		= 11,
2298 	ASCII_FORMFEED		= 12,
2299 	ASCII_CAR_RET		= 13,
2300 	ASCII_IGNORE_LAST	= ASCII_CAR_RET,
2301 	ASCII_SHIFTOUT		= 14,
2302 	ASCII_SHIFTIN		= 15,
2303 	ASCII_CANCEL		= 24,
2304 	ASCII_SUBSTITUTE	= 26,
2305 	ASCII_ESCAPE		= 27,
2306 	ASCII_CSI_IGNORE_FIRST	= ' ', /* 0x2x, 0x3a and 0x3c - 0x3f */
2307 	ASCII_CSI_IGNORE_LAST	= '?',
2308 	ASCII_DEL		= 127,
2309 	ASCII_EXT_CSI		= 128 + ASCII_ESCAPE,
2310 };
2311 
2312 /*
2313  * Handle ascii characters in control sequences and change states accordingly.
2314  * E.g. ESC sets the state of vc to ESesc.
2315  *
2316  * Returns: true if @c handled.
2317  */
2318 static bool handle_ascii(struct tty_struct *tty, struct vc_data *vc, u8 c)
2319 {
2320 	switch (c) {
2321 	case ASCII_NULL:
2322 		return true;
2323 	case ASCII_BELL:
2324 		if (ansi_control_string(vc->vc_state))
2325 			vc->vc_state = ESnormal;
2326 		else if (vc->vc_bell_duration)
2327 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2328 		return true;
2329 	case ASCII_BACKSPACE:
2330 		bs(vc);
2331 		return true;
2332 	case ASCII_HTAB:
2333 		vc->vc_pos -= (vc->state.x << 1);
2334 
2335 		vc->state.x = find_next_bit(vc->vc_tab_stop,
2336 				min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2337 				vc->state.x + 1);
2338 		if (vc->state.x >= VC_TABSTOPS_COUNT)
2339 			vc->state.x = vc->vc_cols - 1;
2340 
2341 		vc->vc_pos += (vc->state.x << 1);
2342 		notify_write(vc, '\t');
2343 		return true;
2344 	case ASCII_LINEFEED:
2345 	case ASCII_VTAB:
2346 	case ASCII_FORMFEED:
2347 		lf(vc);
2348 		if (!is_kbd(vc, lnm))
2349 			return true;
2350 		fallthrough;
2351 	case ASCII_CAR_RET:
2352 		cr(vc);
2353 		return true;
2354 	case ASCII_SHIFTOUT:
2355 		vc->state.charset = 1;
2356 		vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2357 		vc->vc_disp_ctrl = 1;
2358 		return true;
2359 	case ASCII_SHIFTIN:
2360 		vc->state.charset = 0;
2361 		vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2362 		vc->vc_disp_ctrl = 0;
2363 		return true;
2364 	case ASCII_CANCEL:
2365 	case ASCII_SUBSTITUTE:
2366 		vc->vc_state = ESnormal;
2367 		return true;
2368 	case ASCII_ESCAPE:
2369 		vc->vc_state = ESesc;
2370 		return true;
2371 	case ASCII_DEL:
2372 		del(vc);
2373 		return true;
2374 	case ASCII_EXT_CSI:
2375 		vc->vc_state = ESsquare;
2376 		return true;
2377 	}
2378 
2379 	return false;
2380 }
2381 
2382 /*
2383  * Handle a character (@c) following an ESC (when @vc is in the ESesc state).
2384  * E.g. previous ESC with @c == '[' here yields the ESsquare state (that is:
2385  * CSI).
2386  */
2387 static void handle_esc(struct tty_struct *tty, struct vc_data *vc, u8 c)
2388 {
2389 	vc->vc_state = ESnormal;
2390 	switch (c) {
2391 	case '[':
2392 		vc->vc_state = ESsquare;
2393 		break;
2394 	case ']':
2395 		vc->vc_state = ESnonstd;
2396 		break;
2397 	case '_':
2398 		vc->vc_state = ESapc;
2399 		break;
2400 	case '^':
2401 		vc->vc_state = ESpm;
2402 		break;
2403 	case '%':
2404 		vc->vc_state = ESpercent;
2405 		break;
2406 	case 'E':
2407 		cr(vc);
2408 		lf(vc);
2409 		break;
2410 	case 'M':
2411 		ri(vc);
2412 		break;
2413 	case 'D':
2414 		lf(vc);
2415 		break;
2416 	case 'H':
2417 		if (vc->state.x < VC_TABSTOPS_COUNT)
2418 			set_bit(vc->state.x, vc->vc_tab_stop);
2419 		break;
2420 	case 'P':
2421 		vc->vc_state = ESdcs;
2422 		break;
2423 	case 'Z':
2424 		respond_ID(tty);
2425 		break;
2426 	case '7':
2427 		save_cur(vc);
2428 		break;
2429 	case '8':
2430 		restore_cur(vc);
2431 		break;
2432 	case '(':
2433 		vc->vc_state = ESsetG0;
2434 		break;
2435 	case ')':
2436 		vc->vc_state = ESsetG1;
2437 		break;
2438 	case '#':
2439 		vc->vc_state = EShash;
2440 		break;
2441 	case 'c':
2442 		reset_terminal(vc, 1);
2443 		break;
2444 	case '>':  /* Numeric keypad */
2445 		clr_kbd(vc, kbdapplic);
2446 		break;
2447 	case '=':  /* Appl. keypad */
2448 		set_kbd(vc, kbdapplic);
2449 		break;
2450 	}
2451 }
2452 
2453 /*
2454  * Handle special DEC control sequences ("ESC [ ? parameters char"). Parameters
2455  * are in @vc->vc_par and the char is in @c here.
2456  */
2457 static void csi_DEC(struct tty_struct *tty, struct vc_data *vc, u8 c)
2458 {
2459 	switch (c) {
2460 	case 'h':
2461 		csi_DEC_hl(vc, true);
2462 		break;
2463 	case 'l':
2464 		csi_DEC_hl(vc, false);
2465 		break;
2466 	case 'c':
2467 		if (vc->vc_par[0])
2468 			vc->vc_cursor_type = CUR_MAKE(vc->vc_par[0],
2469 						      vc->vc_par[1],
2470 						      vc->vc_par[2]);
2471 		else
2472 			vc->vc_cursor_type = cur_default;
2473 		break;
2474 	case 'm':
2475 		clear_selection();
2476 		if (vc->vc_par[0])
2477 			vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2478 		else
2479 			vc->vc_complement_mask = vc->vc_s_complement_mask;
2480 		break;
2481 	case 'n':
2482 		if (vc->vc_par[0] == 5)
2483 			status_report(tty);
2484 		else if (vc->vc_par[0] == 6)
2485 			cursor_report(vc, tty);
2486 		break;
2487 	}
2488 }
2489 
2490 /*
2491  * Handle Control Sequence Introducer control characters. That is
2492  * "ESC [ parameters char". Parameters are in @vc->vc_par and the char is in
2493  * @c here.
2494  */
2495 static void csi_ECMA(struct tty_struct *tty, struct vc_data *vc, u8 c)
2496 {
2497 	switch (c) {
2498 	case 'G':
2499 	case '`':
2500 		if (vc->vc_par[0])
2501 			vc->vc_par[0]--;
2502 		gotoxy(vc, vc->vc_par[0], vc->state.y);
2503 		break;
2504 	case 'A':
2505 		if (!vc->vc_par[0])
2506 			vc->vc_par[0]++;
2507 		gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2508 		break;
2509 	case 'B':
2510 	case 'e':
2511 		if (!vc->vc_par[0])
2512 			vc->vc_par[0]++;
2513 		gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2514 		break;
2515 	case 'C':
2516 	case 'a':
2517 		if (!vc->vc_par[0])
2518 			vc->vc_par[0]++;
2519 		gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2520 		break;
2521 	case 'D':
2522 		if (!vc->vc_par[0])
2523 			vc->vc_par[0]++;
2524 		gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2525 		break;
2526 	case 'E':
2527 		if (!vc->vc_par[0])
2528 			vc->vc_par[0]++;
2529 		gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2530 		break;
2531 	case 'F':
2532 		if (!vc->vc_par[0])
2533 			vc->vc_par[0]++;
2534 		gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2535 		break;
2536 	case 'd':
2537 		if (vc->vc_par[0])
2538 			vc->vc_par[0]--;
2539 		gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2540 		break;
2541 	case 'H':
2542 	case 'f':
2543 		if (vc->vc_par[0])
2544 			vc->vc_par[0]--;
2545 		if (vc->vc_par[1])
2546 			vc->vc_par[1]--;
2547 		gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2548 		break;
2549 	case 'J':
2550 		csi_J(vc, vc->vc_par[0]);
2551 		break;
2552 	case 'K':
2553 		csi_K(vc);
2554 		break;
2555 	case 'L':
2556 		csi_L(vc);
2557 		break;
2558 	case 'M':
2559 		csi_M(vc);
2560 		break;
2561 	case 'P':
2562 		csi_P(vc);
2563 		break;
2564 	case 'c':
2565 		if (!vc->vc_par[0])
2566 			respond_ID(tty);
2567 		break;
2568 	case 'g':
2569 		if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2570 			set_bit(vc->state.x, vc->vc_tab_stop);
2571 		else if (vc->vc_par[0] == 3)
2572 			bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2573 		break;
2574 	case 'h':
2575 		csi_hl(vc, true);
2576 		break;
2577 	case 'l':
2578 		csi_hl(vc, false);
2579 		break;
2580 	case 'm':
2581 		csi_m(vc);
2582 		break;
2583 	case 'n':
2584 		if (vc->vc_par[0] == 5)
2585 			status_report(tty);
2586 		else if (vc->vc_par[0] == 6)
2587 			cursor_report(vc, tty);
2588 		break;
2589 	case 'q': /* DECLL - but only 3 leds */
2590 		/* map 0,1,2,3 to 0,1,2,4 */
2591 		if (vc->vc_par[0] < 4)
2592 			vt_set_led_state(vc->vc_num,
2593 				    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2594 		break;
2595 	case 'r':
2596 		if (!vc->vc_par[0])
2597 			vc->vc_par[0]++;
2598 		if (!vc->vc_par[1])
2599 			vc->vc_par[1] = vc->vc_rows;
2600 		/* Minimum allowed region is 2 lines */
2601 		if (vc->vc_par[0] < vc->vc_par[1] &&
2602 		    vc->vc_par[1] <= vc->vc_rows) {
2603 			vc->vc_top = vc->vc_par[0] - 1;
2604 			vc->vc_bottom = vc->vc_par[1];
2605 			gotoxay(vc, 0, 0);
2606 		}
2607 		break;
2608 	case 's':
2609 		save_cur(vc);
2610 		break;
2611 	case 'u':
2612 		restore_cur(vc);
2613 		break;
2614 	case 'X':
2615 		csi_X(vc);
2616 		break;
2617 	case '@':
2618 		csi_at(vc, vc->vc_par[0]);
2619 		break;
2620 	case ']':
2621 		csi_RSB(vc);
2622 		break;
2623 	}
2624 
2625 }
2626 
2627 static void vc_reset_params(struct vc_data *vc)
2628 {
2629 	memset(vc->vc_par, 0, sizeof(vc->vc_par));
2630 	vc->vc_npar = 0;
2631 }
2632 
2633 /* console_lock is held */
2634 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, u8 c)
2635 {
2636 	/*
2637 	 *  Control characters can be used in the _middle_
2638 	 *  of an escape sequence, aside from ANSI control strings.
2639 	 */
2640 	if (ansi_control_string(vc->vc_state) && c >= ASCII_IGNORE_FIRST &&
2641 	    c <= ASCII_IGNORE_LAST)
2642 		return;
2643 
2644 	if (handle_ascii(tty, vc, c))
2645 		return;
2646 
2647 	switch(vc->vc_state) {
2648 	case ESesc:	/* ESC */
2649 		handle_esc(tty, vc, c);
2650 		return;
2651 	case ESnonstd:	/* ESC ] aka OSC */
2652 		switch (c) {
2653 		case 'P': /* palette escape sequence */
2654 			vc_reset_params(vc);
2655 			vc->vc_state = ESpalette;
2656 			return;
2657 		case 'R': /* reset palette */
2658 			reset_palette(vc);
2659 			break;
2660 		case '0' ... '9':
2661 			vc->vc_state = ESosc;
2662 			return;
2663 		}
2664 		vc->vc_state = ESnormal;
2665 		return;
2666 	case ESpalette:	/* ESC ] P aka OSC P */
2667 		if (isxdigit(c)) {
2668 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2669 			if (vc->vc_npar == 7) {
2670 				int i = vc->vc_par[0] * 3, j = 1;
2671 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2672 				vc->vc_palette[i++] += vc->vc_par[j++];
2673 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2674 				vc->vc_palette[i++] += vc->vc_par[j++];
2675 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2676 				vc->vc_palette[i] += vc->vc_par[j];
2677 				set_palette(vc);
2678 				vc->vc_state = ESnormal;
2679 			}
2680 		} else
2681 			vc->vc_state = ESnormal;
2682 		return;
2683 	case ESsquare:	/* ESC [ aka CSI, parameters or modifiers expected */
2684 		vc_reset_params(vc);
2685 
2686 		vc->vc_state = ESgetpars;
2687 		switch (c) {
2688 		case '[': /* Function key */
2689 			vc->vc_state = ESfunckey;
2690 			return;
2691 		case '?':
2692 			vc->vc_priv = EPdec;
2693 			return;
2694 		case '>':
2695 			vc->vc_priv = EPgt;
2696 			return;
2697 		case '=':
2698 			vc->vc_priv = EPeq;
2699 			return;
2700 		case '<':
2701 			vc->vc_priv = EPlt;
2702 			return;
2703 		}
2704 		vc->vc_priv = EPecma;
2705 		fallthrough;
2706 	case ESgetpars: /* ESC [ aka CSI, parameters expected */
2707 		switch (c) {
2708 		case ';':
2709 			if (vc->vc_npar < NPAR - 1) {
2710 				vc->vc_npar++;
2711 				return;
2712 			}
2713 			break;
2714 		case '0' ... '9':
2715 			vc->vc_par[vc->vc_npar] *= 10;
2716 			vc->vc_par[vc->vc_npar] += c - '0';
2717 			return;
2718 		}
2719 		if (c >= ASCII_CSI_IGNORE_FIRST && c <= ASCII_CSI_IGNORE_LAST) {
2720 			vc->vc_state = EScsiignore;
2721 			return;
2722 		}
2723 
2724 		/* parameters done, handle the control char @c */
2725 
2726 		vc->vc_state = ESnormal;
2727 
2728 		switch (vc->vc_priv) {
2729 		case EPdec:
2730 			csi_DEC(tty, vc, c);
2731 			return;
2732 		case EPecma:
2733 			csi_ECMA(tty, vc, c);
2734 			return;
2735 		default:
2736 			return;
2737 		}
2738 	case EScsiignore:
2739 		if (c >= ASCII_CSI_IGNORE_FIRST && c <= ASCII_CSI_IGNORE_LAST)
2740 			return;
2741 		vc->vc_state = ESnormal;
2742 		return;
2743 	case ESpercent:	/* ESC % */
2744 		vc->vc_state = ESnormal;
2745 		switch (c) {
2746 		case '@':  /* defined in ISO 2022 */
2747 			vc->vc_utf = 0;
2748 			return;
2749 		case 'G':  /* prelim official escape code */
2750 		case '8':  /* retained for compatibility */
2751 			vc->vc_utf = 1;
2752 			return;
2753 		}
2754 		return;
2755 	case ESfunckey:	/* ESC [ [ aka CSI [ */
2756 		vc->vc_state = ESnormal;
2757 		return;
2758 	case EShash:	/* ESC # */
2759 		vc->vc_state = ESnormal;
2760 		if (c == '8') {
2761 			/* DEC screen alignment test. kludge :-) */
2762 			vc->vc_video_erase_char =
2763 				(vc->vc_video_erase_char & 0xff00) | 'E';
2764 			csi_J(vc, CSI_J_VISIBLE);
2765 			vc->vc_video_erase_char =
2766 				(vc->vc_video_erase_char & 0xff00) | ' ';
2767 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2768 		}
2769 		return;
2770 	case ESsetG0:	/* ESC ( */
2771 		vc_setGx(vc, 0, c);
2772 		vc->vc_state = ESnormal;
2773 		return;
2774 	case ESsetG1:	/* ESC ) */
2775 		vc_setGx(vc, 1, c);
2776 		vc->vc_state = ESnormal;
2777 		return;
2778 	case ESapc:	/* ESC _ */
2779 		return;
2780 	case ESosc:	/* ESC ] [0-9] aka OSC [0-9] */
2781 		return;
2782 	case ESpm:	/* ESC ^ */
2783 		return;
2784 	case ESdcs:	/* ESC P */
2785 		return;
2786 	default:
2787 		vc->vc_state = ESnormal;
2788 	}
2789 }
2790 
2791 struct vc_draw_region {
2792 	unsigned long from, to;
2793 	int x;
2794 };
2795 
2796 static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
2797 {
2798 	if (draw->x < 0)
2799 		return;
2800 
2801 	vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
2802 			(u16 *)draw->to - (u16 *)draw->from, vc->state.y,
2803 			draw->x);
2804 	draw->x = -1;
2805 }
2806 
2807 static inline int vc_translate_ascii(const struct vc_data *vc, int c)
2808 {
2809 	if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
2810 		if (vc->vc_toggle_meta)
2811 			c |= 0x80;
2812 
2813 		return vc->vc_translate[c];
2814 	}
2815 
2816 	return c;
2817 }
2818 
2819 
2820 /**
2821  * vc_sanitize_unicode - Replace invalid Unicode code points with ``U+FFFD``
2822  * @c: the received code point
2823  */
2824 static inline int vc_sanitize_unicode(const int c)
2825 {
2826 	if (c >= 0xd800 && c <= 0xdfff)
2827 		return 0xfffd;
2828 
2829 	return c;
2830 }
2831 
2832 /**
2833  * vc_translate_unicode - Combine UTF-8 into Unicode in &vc_data.vc_utf_char
2834  * @vc: virtual console
2835  * @c: UTF-8 byte to translate
2836  * @rescan: set to true iff @c wasn't consumed here and needs to be re-processed
2837  *
2838  * * &vc_data.vc_utf_char is the being-constructed Unicode code point.
2839  * * &vc_data.vc_utf_count is the number of continuation bytes still expected to
2840  *   arrive.
2841  * * &vc_data.vc_npar is the number of continuation bytes arrived so far.
2842  *
2843  * Return:
2844  * * %-1 - Input OK so far, @c consumed, further bytes expected.
2845  * * %0xFFFD - Possibility 1: input invalid, @c may have been consumed (see
2846  *             desc. of @rescan). Possibility 2: input OK, @c consumed,
2847  *             ``U+FFFD`` is the resulting code point. ``U+FFFD`` is valid,
2848  *             ``REPLACEMENT CHARACTER``.
2849  * * otherwise - Input OK, @c consumed, resulting code point returned.
2850  */
2851 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
2852 {
2853 	static const u32 utf8_length_changes[] = {0x7f, 0x7ff, 0xffff, 0x10ffff};
2854 
2855 	/* Continuation byte received */
2856 	if ((c & 0xc0) == 0x80) {
2857 		/* Unexpected continuation byte? */
2858 		if (!vc->vc_utf_count)
2859 			goto bad_sequence;
2860 
2861 		vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2862 		vc->vc_npar++;
2863 		if (--vc->vc_utf_count)
2864 			goto need_more_bytes;
2865 
2866 		/* Got a whole character */
2867 		c = vc->vc_utf_char;
2868 		/* Reject overlong sequences */
2869 		if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2870 				c > utf8_length_changes[vc->vc_npar])
2871 			goto bad_sequence;
2872 
2873 		return vc_sanitize_unicode(c);
2874 	}
2875 
2876 	/* Single ASCII byte or first byte of a sequence received */
2877 	if (vc->vc_utf_count) {
2878 		/* A continuation byte was expected */
2879 		*rescan = true;
2880 		vc->vc_utf_count = 0;
2881 		goto bad_sequence;
2882 	}
2883 
2884 	/* Nothing to do if an ASCII byte was received */
2885 	if (c <= 0x7f)
2886 		return c;
2887 
2888 	/* First byte of a multibyte sequence received */
2889 	vc->vc_npar = 0;
2890 	if ((c & 0xe0) == 0xc0) {
2891 		vc->vc_utf_count = 1;
2892 		vc->vc_utf_char = (c & 0x1f);
2893 	} else if ((c & 0xf0) == 0xe0) {
2894 		vc->vc_utf_count = 2;
2895 		vc->vc_utf_char = (c & 0x0f);
2896 	} else if ((c & 0xf8) == 0xf0) {
2897 		vc->vc_utf_count = 3;
2898 		vc->vc_utf_char = (c & 0x07);
2899 	} else {
2900 		goto bad_sequence;
2901 	}
2902 
2903 need_more_bytes:
2904 	return -1;
2905 
2906 bad_sequence:
2907 	return 0xfffd;
2908 }
2909 
2910 static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
2911 {
2912 	/* Do no translation at all in control states */
2913 	if (vc->vc_state != ESnormal)
2914 		return *c;
2915 
2916 	if (vc->vc_utf && !vc->vc_disp_ctrl)
2917 		return *c = vc_translate_unicode(vc, *c, rescan);
2918 
2919 	/* no utf or alternate charset mode */
2920 	return vc_translate_ascii(vc, *c);
2921 }
2922 
2923 static inline unsigned char vc_invert_attr(const struct vc_data *vc)
2924 {
2925 	if (!vc->vc_can_do_color)
2926 		return vc->vc_attr ^ 0x08;
2927 
2928 	if (vc->vc_hi_font_mask == 0x100)
2929 		return   (vc->vc_attr & 0x11) |
2930 			((vc->vc_attr & 0xe0) >> 4) |
2931 			((vc->vc_attr & 0x0e) << 4);
2932 
2933 	return   (vc->vc_attr & 0x88) |
2934 		((vc->vc_attr & 0x70) >> 4) |
2935 		((vc->vc_attr & 0x07) << 4);
2936 }
2937 
2938 static bool vc_is_control(struct vc_data *vc, int tc, int c)
2939 {
2940 	/*
2941 	 * A bitmap for codes <32. A bit of 1 indicates that the code
2942 	 * corresponding to that bit number invokes some special action (such
2943 	 * as cursor movement) and should not be displayed as a glyph unless
2944 	 * the disp_ctrl mode is explicitly enabled.
2945 	 */
2946 	static const u32 CTRL_ACTION = BIT(ASCII_NULL) |
2947 		GENMASK(ASCII_SHIFTIN, ASCII_BELL) | BIT(ASCII_CANCEL) |
2948 		BIT(ASCII_SUBSTITUTE) | BIT(ASCII_ESCAPE);
2949 	/* Cannot be overridden by disp_ctrl */
2950 	static const u32 CTRL_ALWAYS = BIT(ASCII_NULL) | BIT(ASCII_BACKSPACE) |
2951 		BIT(ASCII_LINEFEED) | BIT(ASCII_SHIFTIN) | BIT(ASCII_SHIFTOUT) |
2952 		BIT(ASCII_CAR_RET) | BIT(ASCII_FORMFEED) | BIT(ASCII_ESCAPE);
2953 
2954 	if (vc->vc_state != ESnormal)
2955 		return true;
2956 
2957 	if (!tc)
2958 		return true;
2959 
2960 	/*
2961 	 * If the original code was a control character we only allow a glyph
2962 	 * to be displayed if the code is not normally used (such as for cursor
2963 	 * movement) or if the disp_ctrl mode has been explicitly enabled.
2964 	 * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
2965 	 * displayed as control characters, as the console would be pretty
2966 	 * useless without them; to display an arbitrary font position use the
2967 	 * direct-to-font zone in UTF-8 mode.
2968 	 */
2969 	if (c < BITS_PER_TYPE(CTRL_ALWAYS)) {
2970 		if (vc->vc_disp_ctrl)
2971 			return CTRL_ALWAYS & BIT(c);
2972 		else
2973 			return vc->vc_utf || (CTRL_ACTION & BIT(c));
2974 	}
2975 
2976 	if (c == ASCII_DEL && !vc->vc_disp_ctrl)
2977 		return true;
2978 
2979 	if (c == ASCII_EXT_CSI)
2980 		return true;
2981 
2982 	return false;
2983 }
2984 
2985 static void vc_con_rewind(struct vc_data *vc)
2986 {
2987 	if (vc->state.x && !vc->vc_need_wrap) {
2988 		vc->vc_pos -= 2;
2989 		vc->state.x--;
2990 	}
2991 	vc->vc_need_wrap = 0;
2992 }
2993 
2994 #define UCS_ZWS		0x200b	/* Zero Width Space */
2995 #define UCS_VS16	0xfe0f	/* Variation Selector 16 */
2996 #define UCS_REPLACEMENT	0xfffd	/* Replacement Character */
2997 
2998 static int vc_process_ucs(struct vc_data *vc, int *c, int *tc)
2999 {
3000 	u32 prev_c, curr_c = *c;
3001 
3002 	if (ucs_is_double_width(curr_c)) {
3003 		/*
3004 		 * The Unicode screen memory is allocated only when
3005 		 * required. This is one such case as we need to remember
3006 		 * which displayed characters are double-width.
3007 		 */
3008 		vc_uniscr_check(vc);
3009 		return 2;
3010 	}
3011 
3012 	if (!ucs_is_zero_width(curr_c))
3013 		return 1;
3014 
3015 	/* From here curr_c is known to be zero-width. */
3016 
3017 	if (ucs_is_double_width(vc_uniscr_getc(vc, -2))) {
3018 		/*
3019 		 * Let's merge this zero-width code point with the preceding
3020 		 * double-width code point by replacing the existing
3021 		 * zero-width space padding. To do so we rewind one column
3022 		 * and pretend this has a width of 1.
3023 		 * We give the legacy display the same initial space padding.
3024 		 */
3025 		vc_con_rewind(vc);
3026 		*tc = ' ';
3027 		return 1;
3028 	}
3029 
3030 	/* From here the preceding character, if any, must be single-width. */
3031 	prev_c = vc_uniscr_getc(vc, -1);
3032 
3033 	if (curr_c == UCS_VS16 && prev_c != 0) {
3034 		/*
3035 		 * VS16 (U+FE0F) is special. It typically turns the preceding
3036 		 * single-width character into a double-width one. Let it
3037 		 * have a width of 1 effectively making the combination with
3038 		 * the preceding character double-width.
3039 		 */
3040 		*tc = ' ';
3041 		return 1;
3042 	}
3043 
3044 	/* try recomposition */
3045 	prev_c = ucs_recompose(prev_c, curr_c);
3046 	if (prev_c != 0) {
3047 		vc_con_rewind(vc);
3048 		*tc = *c = prev_c;
3049 		return 1;
3050 	}
3051 
3052 	/* Otherwise zero-width code points are ignored. */
3053 	return 0;
3054 }
3055 
3056 static int vc_get_glyph(struct vc_data *vc, int tc)
3057 {
3058 	int glyph = conv_uni_to_pc(vc, tc);
3059 	u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
3060 
3061 	if (!(glyph & ~charmask))
3062 		return glyph;
3063 
3064 	if (glyph == -1)
3065 		return -1; /* nothing to display */
3066 
3067 	/* Glyph not found */
3068 	if ((!vc->vc_utf || vc->vc_disp_ctrl || tc < 128) && !(tc & ~charmask)) {
3069 		/*
3070 		 * In legacy mode use the glyph we get by a 1:1 mapping.
3071 		 * This would make absolutely no sense with Unicode in mind, but do this for
3072 		 * ASCII characters since a font may lack Unicode mapping info and we don't
3073 		 * want to end up with having question marks only.
3074 		 */
3075 		return tc;
3076 	}
3077 
3078 	/*
3079 	 * The Unicode screen memory is allocated only when required.
3080 	 * This is one such case: we're about to "cheat" with the displayed
3081 	 * character meaning the simple screen buffer won't hold the original
3082 	 * information, whereas the Unicode screen buffer always does.
3083 	 */
3084 	vc_uniscr_check(vc);
3085 
3086 	/* Try getting a simpler fallback character. */
3087 	tc = ucs_get_fallback(tc);
3088 	if (tc)
3089 		return vc_get_glyph(vc, tc);
3090 
3091 	/* Display U+FFFD (Unicode Replacement Character). */
3092 	return conv_uni_to_pc(vc, UCS_REPLACEMENT);
3093 }
3094 
3095 static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
3096 		struct vc_draw_region *draw)
3097 {
3098 	int next_c;
3099 	unsigned char vc_attr = vc->vc_attr;
3100 	u16 himask = vc->vc_hi_font_mask;
3101 	u8 width = 1;
3102 	bool inverse = false;
3103 
3104 	if (vc->vc_utf && !vc->vc_disp_ctrl) {
3105 		width = vc_process_ucs(vc, &c, &tc);
3106 		if (!width)
3107 			goto out;
3108 	}
3109 
3110 	/* Now try to find out how to display it */
3111 	tc = vc_get_glyph(vc, tc);
3112 	if (tc == -1)
3113 		return -1; /* nothing to display */
3114 	if (tc < 0) {
3115 		inverse = true;
3116 		tc = conv_uni_to_pc(vc, '?');
3117 		if (tc < 0)
3118 			tc = '?';
3119 
3120 		vc_attr = vc_invert_attr(vc);
3121 		con_flush(vc, draw);
3122 	}
3123 
3124 	next_c = c;
3125 	while (1) {
3126 		if (vc->vc_need_wrap || vc->vc_decim)
3127 			con_flush(vc, draw);
3128 		if (vc->vc_need_wrap) {
3129 			cr(vc);
3130 			lf(vc);
3131 		}
3132 		if (vc->vc_decim)
3133 			insert_char(vc, 1);
3134 		vc_uniscr_putc(vc, next_c);
3135 
3136 		if (himask)
3137 			tc = ((tc & 0x100) ? himask : 0) |
3138 			      (tc &  0xff);
3139 		tc |= (vc_attr << 8) & ~himask;
3140 
3141 		scr_writew(tc, (u16 *)vc->vc_pos);
3142 
3143 		if (con_should_update(vc) && draw->x < 0) {
3144 			draw->x = vc->state.x;
3145 			draw->from = vc->vc_pos;
3146 		}
3147 		if (vc->state.x == vc->vc_cols - 1) {
3148 			vc->vc_need_wrap = vc->vc_decawm;
3149 			draw->to = vc->vc_pos + 2;
3150 		} else {
3151 			vc->state.x++;
3152 			draw->to = (vc->vc_pos += 2);
3153 		}
3154 
3155 		if (!--width)
3156 			break;
3157 
3158 		/* A space is printed in the second column */
3159 		tc = conv_uni_to_pc(vc, ' ');
3160 		if (tc < 0)
3161 			tc = ' ';
3162 		/*
3163 		 * Store a zero-width space in the Unicode screen given that
3164 		 * the previous code point is semantically double width.
3165 		 */
3166 		next_c = UCS_ZWS;
3167 	}
3168 
3169 out:
3170 	notify_write(vc, c);
3171 
3172 	if (inverse)
3173 		con_flush(vc, draw);
3174 
3175 	return 0;
3176 }
3177 
3178 /* acquires console_lock */
3179 static int do_con_write(struct tty_struct *tty, const u8 *buf, int count)
3180 {
3181 	struct vc_draw_region draw = {
3182 		.x = -1,
3183 	};
3184 	int c, tc, n = 0;
3185 	unsigned int currcons;
3186 	struct vc_data *vc = tty->driver_data;
3187 	struct vt_notifier_param param;
3188 	bool rescan;
3189 
3190 	if (in_interrupt())
3191 		return count;
3192 
3193 	guard(console_lock)();
3194 	currcons = vc->vc_num;
3195 	if (!vc_cons_allocated(currcons)) {
3196 		/* could this happen? */
3197 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
3198 		return 0;
3199 	}
3200 
3201 
3202 	/* undraw cursor first */
3203 	if (con_is_fg(vc))
3204 		hide_cursor(vc);
3205 
3206 	param.vc = vc;
3207 
3208 	while (!tty->flow.stopped && count) {
3209 		u8 orig = *buf;
3210 		buf++;
3211 		n++;
3212 		count--;
3213 rescan_last_byte:
3214 		c = orig;
3215 		rescan = false;
3216 
3217 		tc = vc_translate(vc, &c, &rescan);
3218 		if (tc == -1)
3219 			continue;
3220 
3221 		param.c = tc;
3222 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
3223 					&param) == NOTIFY_STOP)
3224 			continue;
3225 
3226 		if (vc_is_control(vc, tc, c)) {
3227 			con_flush(vc, &draw);
3228 			do_con_trol(tty, vc, orig);
3229 			continue;
3230 		}
3231 
3232 		if (vc_con_write_normal(vc, tc, c, &draw) < 0)
3233 			continue;
3234 
3235 		if (rescan)
3236 			goto rescan_last_byte;
3237 	}
3238 	con_flush(vc, &draw);
3239 	console_conditional_schedule();
3240 	notify_update(vc);
3241 
3242 	return n;
3243 }
3244 
3245 /*
3246  * This is the console switching callback.
3247  *
3248  * Doing console switching in a process context allows
3249  * us to do the switches asynchronously (needed when we want
3250  * to switch due to a keyboard interrupt).  Synchronization
3251  * with other console code and prevention of re-entrancy is
3252  * ensured with console_lock.
3253  */
3254 static void console_callback(struct work_struct *ignored)
3255 {
3256 	guard(console_lock)();
3257 
3258 	if (want_console >= 0) {
3259 		if (want_console != fg_console &&
3260 		    vc_cons_allocated(want_console)) {
3261 			hide_cursor(vc_cons[fg_console].d);
3262 			change_console(vc_cons[want_console].d);
3263 			/* we only changed when the console had already
3264 			   been allocated - a new console is not created
3265 			   in an interrupt routine */
3266 		}
3267 		want_console = -1;
3268 	}
3269 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
3270 		do_poke_blanked_console = 0;
3271 		poke_blanked_console();
3272 	}
3273 	if (scrollback_delta) {
3274 		struct vc_data *vc = vc_cons[fg_console].d;
3275 		clear_selection();
3276 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
3277 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
3278 		scrollback_delta = 0;
3279 	}
3280 	if (blank_timer_expired) {
3281 		do_blank_screen(0);
3282 		blank_timer_expired = 0;
3283 	}
3284 	notify_update(vc_cons[fg_console].d);
3285 }
3286 
3287 int set_console(int nr)
3288 {
3289 	struct vc_data *vc = vc_cons[fg_console].d;
3290 
3291 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
3292 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
3293 
3294 		/*
3295 		 * Console switch will fail in console_callback() or
3296 		 * change_console() so there is no point scheduling
3297 		 * the callback
3298 		 *
3299 		 * Existing set_console() users don't check the return
3300 		 * value so this shouldn't break anything
3301 		 */
3302 		return -EINVAL;
3303 	}
3304 
3305 	want_console = nr;
3306 	schedule_console_callback();
3307 
3308 	return 0;
3309 }
3310 
3311 struct tty_driver *console_driver;
3312 
3313 #ifdef CONFIG_VT_CONSOLE
3314 
3315 /**
3316  * vt_kmsg_redirect() - sets/gets the kernel message console
3317  * @new: the new virtual terminal number or -1 if the console should stay
3318  *	unchanged
3319  *
3320  * By default, the kernel messages are always printed on the current virtual
3321  * console. However, the user may modify that default with the
3322  * %TIOCL_SETKMSGREDIRECT ioctl call.
3323  *
3324  * This function sets the kernel message console to be @new. It returns the old
3325  * virtual console number. The virtual terminal number %0 (both as parameter and
3326  * return value) means no redirection (i.e. always printed on the currently
3327  * active console).
3328  *
3329  * The parameter -1 means that only the current console is returned, but the
3330  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
3331  * case to make the code more understandable.
3332  *
3333  * When the kernel is compiled without %CONFIG_VT_CONSOLE, this function ignores
3334  * the parameter and always returns %0.
3335  */
3336 int vt_kmsg_redirect(int new)
3337 {
3338 	static int kmsg_con;
3339 
3340 	if (new != -1)
3341 		return xchg(&kmsg_con, new);
3342 	else
3343 		return kmsg_con;
3344 }
3345 
3346 /*
3347  *	Console on virtual terminal
3348  *
3349  * The console must be locked when we get here.
3350  */
3351 
3352 static void vt_console_print(struct console *co, const char *b, unsigned count)
3353 {
3354 	struct vc_data *vc = vc_cons[fg_console].d;
3355 	unsigned char c;
3356 	static DEFINE_SPINLOCK(printing_lock);
3357 	const ushort *start;
3358 	ushort start_x, cnt;
3359 	int kmsg_console;
3360 
3361 	WARN_CONSOLE_UNLOCKED();
3362 
3363 	/* this protects against concurrent oops only */
3364 	if (!spin_trylock(&printing_lock))
3365 		return;
3366 
3367 	kmsg_console = vt_get_kmsg_redirect();
3368 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
3369 		vc = vc_cons[kmsg_console - 1].d;
3370 
3371 	if (!vc_cons_allocated(fg_console)) {
3372 		/* impossible */
3373 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
3374 		goto quit;
3375 	}
3376 
3377 	if (vc->vc_mode != KD_TEXT)
3378 		goto quit;
3379 
3380 	/* undraw cursor first */
3381 	if (con_is_fg(vc))
3382 		hide_cursor(vc);
3383 
3384 	start = (ushort *)vc->vc_pos;
3385 	start_x = vc->state.x;
3386 	cnt = 0;
3387 	while (count--) {
3388 		c = *b++;
3389 		if (c == ASCII_LINEFEED || c == ASCII_CAR_RET ||
3390 		    c == ASCII_BACKSPACE || vc->vc_need_wrap) {
3391 			if (cnt && con_is_visible(vc))
3392 				vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3393 			cnt = 0;
3394 			if (c == ASCII_BACKSPACE) {
3395 				bs(vc);
3396 				start = (ushort *)vc->vc_pos;
3397 				start_x = vc->state.x;
3398 				continue;
3399 			}
3400 			if (c != ASCII_CAR_RET)
3401 				lf(vc);
3402 			cr(vc);
3403 			start = (ushort *)vc->vc_pos;
3404 			start_x = vc->state.x;
3405 			if (c == ASCII_LINEFEED || c == ASCII_CAR_RET)
3406 				continue;
3407 		}
3408 		vc_uniscr_putc(vc, c);
3409 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3410 		notify_write(vc, c);
3411 		cnt++;
3412 		if (vc->state.x == vc->vc_cols - 1) {
3413 			vc->vc_need_wrap = 1;
3414 		} else {
3415 			vc->vc_pos += 2;
3416 			vc->state.x++;
3417 		}
3418 	}
3419 	if (cnt && con_is_visible(vc))
3420 		vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3421 	set_cursor(vc);
3422 	notify_update(vc);
3423 
3424 quit:
3425 	spin_unlock(&printing_lock);
3426 }
3427 
3428 static struct tty_driver *vt_console_device(struct console *c, int *index)
3429 {
3430 	*index = c->index ? c->index-1 : fg_console;
3431 	return console_driver;
3432 }
3433 
3434 static int vt_console_setup(struct console *co, char *options)
3435 {
3436 	return co->index >= MAX_NR_CONSOLES ? -EINVAL : 0;
3437 }
3438 
3439 static struct console vt_console_driver = {
3440 	.name		= "tty",
3441 	.setup		= vt_console_setup,
3442 	.write		= vt_console_print,
3443 	.device		= vt_console_device,
3444 	.unblank	= unblank_screen,
3445 	.flags		= CON_PRINTBUFFER,
3446 	.index		= -1,
3447 };
3448 #endif
3449 
3450 /*
3451  *	Handling of Linux-specific VC ioctls
3452  */
3453 
3454 /*
3455  * Generally a bit racy with respect to console_lock();.
3456  *
3457  * There are some functions which don't need it.
3458  *
3459  * There are some functions which can sleep for arbitrary periods
3460  * (paste_selection) but we don't need the lock there anyway.
3461  *
3462  * set_selection_user has locking, and definitely needs it
3463  */
3464 
3465 int tioclinux(struct tty_struct *tty, unsigned long arg)
3466 {
3467 	char type, data;
3468 	char __user *p = (char __user *)arg;
3469 	void __user *param_aligned32 = (u32 __user *)arg + 1;
3470 	void __user *param = (void __user *)arg + 1;
3471 	int lines;
3472 	int ret;
3473 
3474 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3475 		return -EPERM;
3476 	if (get_user(type, p))
3477 		return -EFAULT;
3478 	ret = 0;
3479 
3480 	switch (type) {
3481 	case TIOCL_SETSEL:
3482 		return set_selection_user(param, tty);
3483 	case TIOCL_PASTESEL:
3484 		if (!capable(CAP_SYS_ADMIN))
3485 			return -EPERM;
3486 		return paste_selection(tty);
3487 	case TIOCL_UNBLANKSCREEN:
3488 		scoped_guard(console_lock)
3489 			unblank_screen();
3490 		break;
3491 	case TIOCL_SELLOADLUT:
3492 		if (!capable(CAP_SYS_ADMIN))
3493 			return -EPERM;
3494 		return sel_loadlut(param_aligned32);
3495 	case TIOCL_GETSHIFTSTATE:
3496 		/*
3497 		 * Make it possible to react to Shift+Mousebutton. Note that
3498 		 * 'shift_state' is an undocumented kernel-internal variable;
3499 		 * programs not closely related to the kernel should not use
3500 		 * this.
3501 		 */
3502 		data = vt_get_shift_state();
3503 		return put_user(data, p);
3504 	case TIOCL_GETMOUSEREPORTING:
3505 		scoped_guard(console_lock)	/* May be overkill */
3506 			data = mouse_reporting();
3507 		return put_user(data, p);
3508 	case TIOCL_SETVESABLANK:
3509 		return set_vesa_blanking(param);
3510 	case TIOCL_GETKMSGREDIRECT:
3511 		data = vt_get_kmsg_redirect();
3512 		return put_user(data, p);
3513 	case TIOCL_SETKMSGREDIRECT:
3514 		if (!capable(CAP_SYS_ADMIN))
3515 			return -EPERM;
3516 
3517 		if (get_user(data, p+1))
3518 			return -EFAULT;
3519 
3520 		vt_kmsg_redirect(data);
3521 
3522 		break;
3523 	case TIOCL_GETFGCONSOLE:
3524 		/*
3525 		 * No locking needed as this is a transiently correct return
3526 		 * anyway if the caller hasn't disabled switching.
3527 		 */
3528 		return fg_console;
3529 	case TIOCL_SCROLLCONSOLE:
3530 		if (get_user(lines, (s32 __user *)param_aligned32))
3531 			return -EFAULT;
3532 
3533 		/*
3534 		 * Needs the console lock here. Note that lots of other calls
3535 		 * need fixing before the lock is actually useful!
3536 		 */
3537 		scoped_guard(console_lock)
3538 			scrollfront(vc_cons[fg_console].d, lines);
3539 		break;
3540 	case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
3541 		scoped_guard(console_lock) {
3542 			ignore_poke = 1;
3543 			do_blank_screen(0);
3544 		}
3545 		break;
3546 	case TIOCL_BLANKEDSCREEN:
3547 		return console_blanked;
3548 	case TIOCL_GETBRACKETEDPASTE:
3549 		return get_bracketed_paste(tty);
3550 	default:
3551 		return -EINVAL;
3552 	}
3553 
3554 	return ret;
3555 }
3556 
3557 /*
3558  * /dev/ttyN handling
3559  */
3560 
3561 static ssize_t con_write(struct tty_struct *tty, const u8 *buf, size_t count)
3562 {
3563 	int	retval;
3564 
3565 	retval = do_con_write(tty, buf, count);
3566 	con_flush_chars(tty);
3567 
3568 	return retval;
3569 }
3570 
3571 static int con_put_char(struct tty_struct *tty, u8 ch)
3572 {
3573 	return do_con_write(tty, &ch, 1);
3574 }
3575 
3576 static unsigned int con_write_room(struct tty_struct *tty)
3577 {
3578 	if (tty->flow.stopped)
3579 		return 0;
3580 	return 32768;		/* No limit, really; we're not buffering */
3581 }
3582 
3583 /*
3584  * con_throttle and con_unthrottle are only used for
3585  * paste_selection(), which has to stuff in a large number of
3586  * characters...
3587  */
3588 static void con_throttle(struct tty_struct *tty)
3589 {
3590 }
3591 
3592 static void con_unthrottle(struct tty_struct *tty)
3593 {
3594 	struct vc_data *vc = tty->driver_data;
3595 
3596 	wake_up_interruptible(&vc->paste_wait);
3597 }
3598 
3599 /*
3600  * Turn the Scroll-Lock LED on when the tty is stopped
3601  */
3602 static void con_stop(struct tty_struct *tty)
3603 {
3604 	int console_num;
3605 	if (!tty)
3606 		return;
3607 	console_num = tty->index;
3608 	if (!vc_cons_allocated(console_num))
3609 		return;
3610 	vt_kbd_con_stop(console_num);
3611 }
3612 
3613 /*
3614  * Turn the Scroll-Lock LED off when the console is started
3615  */
3616 static void con_start(struct tty_struct *tty)
3617 {
3618 	int console_num;
3619 	if (!tty)
3620 		return;
3621 	console_num = tty->index;
3622 	if (!vc_cons_allocated(console_num))
3623 		return;
3624 	vt_kbd_con_start(console_num);
3625 }
3626 
3627 static void con_flush_chars(struct tty_struct *tty)
3628 {
3629 	struct vc_data *vc = tty->driver_data;
3630 
3631 	if (in_interrupt())	/* from flush_to_ldisc */
3632 		return;
3633 
3634 	guard(console_lock)();
3635 	set_cursor(vc);
3636 }
3637 
3638 /*
3639  * Allocate the console screen memory.
3640  */
3641 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3642 {
3643 	unsigned int currcons = tty->index;
3644 	struct vc_data *vc;
3645 	int ret;
3646 
3647 	guard(console_lock)();
3648 	ret = vc_allocate(currcons);
3649 	if (ret)
3650 		return ret;
3651 
3652 	vc = vc_cons[currcons].d;
3653 
3654 	/* Still being freed */
3655 	if (vc->port.tty)
3656 		return -ERESTARTSYS;
3657 
3658 	ret = tty_port_install(&vc->port, driver, tty);
3659 	if (ret)
3660 		return ret;
3661 
3662 	tty->driver_data = vc;
3663 	vc->port.tty = tty;
3664 	tty_port_get(&vc->port);
3665 
3666 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3667 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3668 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3669 	}
3670 	if (vc->vc_utf)
3671 		tty->termios.c_iflag |= IUTF8;
3672 	else
3673 		tty->termios.c_iflag &= ~IUTF8;
3674 
3675 	return 0;
3676 }
3677 
3678 static int con_open(struct tty_struct *tty, struct file *filp)
3679 {
3680 	/* everything done in install */
3681 	return 0;
3682 }
3683 
3684 
3685 static void con_close(struct tty_struct *tty, struct file *filp)
3686 {
3687 	/* Nothing to do - we defer to shutdown */
3688 }
3689 
3690 static void con_shutdown(struct tty_struct *tty)
3691 {
3692 	struct vc_data *vc = tty->driver_data;
3693 	BUG_ON(vc == NULL);
3694 
3695 	guard(console_lock)();
3696 	vc->port.tty = NULL;
3697 }
3698 
3699 static void con_cleanup(struct tty_struct *tty)
3700 {
3701 	struct vc_data *vc = tty->driver_data;
3702 
3703 	tty_port_put(&vc->port);
3704 }
3705 
3706 /*
3707  * We can't deal with anything but the N_TTY ldisc,
3708  * because we can sleep in our write() routine.
3709  */
3710 static int con_ldisc_ok(struct tty_struct *tty, int ldisc)
3711 {
3712 	return ldisc == N_TTY ? 0 : -EINVAL;
3713 }
3714 
3715 static int default_color           = 7; /* white */
3716 static int default_italic_color    = 2; // green (ASCII)
3717 static int default_underline_color = 3; // cyan (ASCII)
3718 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3719 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3720 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3721 
3722 static void vc_init(struct vc_data *vc, int do_clear)
3723 {
3724 	int j, k ;
3725 
3726 	set_origin(vc);
3727 	vc->vc_pos = vc->vc_origin;
3728 	reset_vc(vc);
3729 	for (j=k=0; j<16; j++) {
3730 		vc->vc_palette[k++] = default_red[j] ;
3731 		vc->vc_palette[k++] = default_grn[j] ;
3732 		vc->vc_palette[k++] = default_blu[j] ;
3733 	}
3734 	vc->vc_def_color       = default_color;
3735 	vc->vc_ulcolor         = default_underline_color;
3736 	vc->vc_itcolor         = default_italic_color;
3737 	vc->vc_halfcolor       = 0x08;   /* grey */
3738 	init_waitqueue_head(&vc->paste_wait);
3739 	reset_terminal(vc, do_clear);
3740 }
3741 
3742 /*
3743  * This routine initializes console interrupts, and does nothing
3744  * else. If you want the screen to clear, call tty_write with
3745  * the appropriate escape-sequence.
3746  */
3747 
3748 static int __init con_init(void)
3749 {
3750 	const char *display_desc = NULL;
3751 	struct vc_data *vc;
3752 	unsigned int currcons = 0, i;
3753 
3754 	console_lock();
3755 
3756 	if (!conswitchp)
3757 		conswitchp = &dummy_con;
3758 	display_desc = conswitchp->con_startup();
3759 	if (!display_desc) {
3760 		fg_console = 0;
3761 		console_unlock();
3762 		return 0;
3763 	}
3764 
3765 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3766 		struct con_driver *con_driver = &registered_con_driver[i];
3767 
3768 		if (con_driver->con == NULL) {
3769 			con_driver->con = conswitchp;
3770 			con_driver->desc = display_desc;
3771 			con_driver->flag = CON_DRIVER_FLAG_INIT;
3772 			con_driver->first = 0;
3773 			con_driver->last = MAX_NR_CONSOLES - 1;
3774 			break;
3775 		}
3776 	}
3777 
3778 	for (i = 0; i < MAX_NR_CONSOLES; i++)
3779 		con_driver_map[i] = conswitchp;
3780 
3781 	if (blankinterval) {
3782 		blank_state = blank_normal_wait;
3783 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3784 	}
3785 
3786 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3787 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3788 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3789 		tty_port_init(&vc->port);
3790 		visual_init(vc, currcons, true);
3791 		/* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3792 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3793 		vc_init(vc, currcons || !vc->vc_sw->con_save_screen);
3794 	}
3795 	currcons = fg_console = 0;
3796 	master_display_fg = vc = vc_cons[currcons].d;
3797 	set_origin(vc);
3798 	save_screen(vc);
3799 	gotoxy(vc, vc->state.x, vc->state.y);
3800 	csi_J(vc, CSI_J_CURSOR_TO_END);
3801 	update_screen(vc);
3802 	pr_info("Console: %s %s %dx%d\n",
3803 		vc->vc_can_do_color ? "colour" : "mono",
3804 		display_desc, vc->vc_cols, vc->vc_rows);
3805 
3806 	console_unlock();
3807 
3808 #ifdef CONFIG_VT_CONSOLE
3809 	register_console(&vt_console_driver);
3810 #endif
3811 	return 0;
3812 }
3813 console_initcall(con_init);
3814 
3815 static const struct tty_operations con_ops = {
3816 	.install = con_install,
3817 	.open = con_open,
3818 	.close = con_close,
3819 	.write = con_write,
3820 	.write_room = con_write_room,
3821 	.put_char = con_put_char,
3822 	.flush_chars = con_flush_chars,
3823 	.ioctl = vt_ioctl,
3824 #ifdef CONFIG_COMPAT
3825 	.compat_ioctl = vt_compat_ioctl,
3826 #endif
3827 	.stop = con_stop,
3828 	.start = con_start,
3829 	.throttle = con_throttle,
3830 	.unthrottle = con_unthrottle,
3831 	.resize = vt_resize,
3832 	.shutdown = con_shutdown,
3833 	.cleanup = con_cleanup,
3834 	.ldisc_ok = con_ldisc_ok,
3835 };
3836 
3837 static struct cdev vc0_cdev;
3838 
3839 static ssize_t show_tty_active(struct device *dev,
3840 				struct device_attribute *attr, char *buf)
3841 {
3842 	return sprintf(buf, "tty%d\n", fg_console + 1);
3843 }
3844 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3845 
3846 static struct attribute *vt_dev_attrs[] = {
3847 	&dev_attr_active.attr,
3848 	NULL
3849 };
3850 
3851 ATTRIBUTE_GROUPS(vt_dev);
3852 
3853 int __init vty_init(const struct file_operations *console_fops)
3854 {
3855 	cdev_init(&vc0_cdev, console_fops);
3856 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3857 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3858 		panic("Couldn't register /dev/tty0 driver\n");
3859 	tty0dev = device_create_with_groups(&tty_class, NULL,
3860 					    MKDEV(TTY_MAJOR, 0), NULL,
3861 					    vt_dev_groups, "tty0");
3862 	if (IS_ERR(tty0dev))
3863 		tty0dev = NULL;
3864 
3865 	vcs_init();
3866 
3867 	console_driver = tty_alloc_driver(MAX_NR_CONSOLES, TTY_DRIVER_REAL_RAW |
3868 			TTY_DRIVER_RESET_TERMIOS);
3869 	if (IS_ERR(console_driver))
3870 		panic("Couldn't allocate console driver\n");
3871 
3872 	console_driver->name = "tty";
3873 	console_driver->name_base = 1;
3874 	console_driver->major = TTY_MAJOR;
3875 	console_driver->minor_start = 1;
3876 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3877 	console_driver->init_termios = tty_std_termios;
3878 	if (default_utf8)
3879 		console_driver->init_termios.c_iflag |= IUTF8;
3880 	tty_set_operations(console_driver, &con_ops);
3881 	if (tty_register_driver(console_driver))
3882 		panic("Couldn't register console driver\n");
3883 	kbd_init();
3884 	console_map_init();
3885 #ifdef CONFIG_MDA_CONSOLE
3886 	mda_console_init();
3887 #endif
3888 	return 0;
3889 }
3890 
3891 static const struct class vtconsole_class = {
3892 	.name = "vtconsole",
3893 };
3894 
3895 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3896 			   int deflt)
3897 {
3898 	struct module *owner = csw->owner;
3899 	const char *desc = NULL;
3900 	struct con_driver *con_driver;
3901 	int i, j = -1, k = -1, retval = -ENODEV;
3902 
3903 	if (!try_module_get(owner))
3904 		return -ENODEV;
3905 
3906 	WARN_CONSOLE_UNLOCKED();
3907 
3908 	/* check if driver is registered */
3909 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3910 		con_driver = &registered_con_driver[i];
3911 
3912 		if (con_driver->con == csw) {
3913 			desc = con_driver->desc;
3914 			retval = 0;
3915 			break;
3916 		}
3917 	}
3918 
3919 	if (retval)
3920 		goto err;
3921 
3922 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3923 		csw->con_startup();
3924 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3925 	}
3926 
3927 	if (deflt) {
3928 		if (conswitchp)
3929 			module_put(conswitchp->owner);
3930 
3931 		__module_get(owner);
3932 		conswitchp = csw;
3933 	}
3934 
3935 	first = max(first, con_driver->first);
3936 	last = min(last, con_driver->last);
3937 
3938 	for (i = first; i <= last; i++) {
3939 		int old_was_color;
3940 		struct vc_data *vc = vc_cons[i].d;
3941 
3942 		if (con_driver_map[i])
3943 			module_put(con_driver_map[i]->owner);
3944 		__module_get(owner);
3945 		con_driver_map[i] = csw;
3946 
3947 		if (!vc || !vc->vc_sw)
3948 			continue;
3949 
3950 		j = i;
3951 
3952 		if (con_is_visible(vc)) {
3953 			k = i;
3954 			save_screen(vc);
3955 		}
3956 
3957 		old_was_color = vc->vc_can_do_color;
3958 		vc->vc_sw->con_deinit(vc);
3959 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3960 		visual_init(vc, i, false);
3961 		set_origin(vc);
3962 		update_attr(vc);
3963 
3964 		/* If the console changed between mono <-> color, then
3965 		 * the attributes in the screenbuf will be wrong.  The
3966 		 * following resets all attributes to something sane.
3967 		 */
3968 		if (old_was_color != vc->vc_can_do_color)
3969 			clear_buffer_attributes(vc);
3970 	}
3971 
3972 	pr_info("Console: switching ");
3973 	if (!deflt)
3974 		pr_cont("consoles %d-%d ", first + 1, last + 1);
3975 	if (j >= 0) {
3976 		struct vc_data *vc = vc_cons[j].d;
3977 
3978 		pr_cont("to %s %s %dx%d\n",
3979 			vc->vc_can_do_color ? "colour" : "mono",
3980 			desc, vc->vc_cols, vc->vc_rows);
3981 
3982 		if (k >= 0) {
3983 			vc = vc_cons[k].d;
3984 			update_screen(vc);
3985 		}
3986 	} else {
3987 		pr_cont("to %s\n", desc);
3988 	}
3989 
3990 	retval = 0;
3991 err:
3992 	module_put(owner);
3993 	return retval;
3994 };
3995 
3996 
3997 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3998 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3999 {
4000 	struct module *owner = csw->owner;
4001 	const struct consw *defcsw = NULL;
4002 	struct con_driver *con_driver = NULL, *con_back = NULL;
4003 	int i, retval = -ENODEV;
4004 
4005 	if (!try_module_get(owner))
4006 		return -ENODEV;
4007 
4008 	WARN_CONSOLE_UNLOCKED();
4009 
4010 	/* check if driver is registered and if it is unbindable */
4011 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4012 		con_driver = &registered_con_driver[i];
4013 
4014 		if (con_driver->con == csw &&
4015 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
4016 			retval = 0;
4017 			break;
4018 		}
4019 	}
4020 
4021 	if (retval)
4022 		goto err;
4023 
4024 	retval = -ENODEV;
4025 
4026 	/* check if backup driver exists */
4027 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4028 		con_back = &registered_con_driver[i];
4029 
4030 		if (con_back->con && con_back->con != csw) {
4031 			defcsw = con_back->con;
4032 			retval = 0;
4033 			break;
4034 		}
4035 	}
4036 
4037 	if (retval)
4038 		goto err;
4039 
4040 	if (!con_is_bound(csw))
4041 		goto err;
4042 
4043 	first = max(first, con_driver->first);
4044 	last = min(last, con_driver->last);
4045 
4046 	for (i = first; i <= last; i++) {
4047 		if (con_driver_map[i] == csw) {
4048 			module_put(csw->owner);
4049 			con_driver_map[i] = NULL;
4050 		}
4051 	}
4052 
4053 	if (!con_is_bound(defcsw)) {
4054 		const struct consw *defconsw = conswitchp;
4055 
4056 		defcsw->con_startup();
4057 		con_back->flag |= CON_DRIVER_FLAG_INIT;
4058 		/*
4059 		 * vgacon may change the default driver to point
4060 		 * to dummycon, we restore it here...
4061 		 */
4062 		conswitchp = defconsw;
4063 	}
4064 
4065 	if (!con_is_bound(csw))
4066 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
4067 
4068 	/* ignore return value, binding should not fail */
4069 	do_bind_con_driver(defcsw, first, last, deflt);
4070 err:
4071 	module_put(owner);
4072 	return retval;
4073 
4074 }
4075 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
4076 
4077 static int vt_bind(struct con_driver *con)
4078 {
4079 	const struct consw *defcsw = NULL, *csw = NULL;
4080 	int i, more = 1, first = -1, last = -1, deflt = 0;
4081 
4082  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
4083 		goto err;
4084 
4085 	csw = con->con;
4086 
4087 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4088 		struct con_driver *con = &registered_con_driver[i];
4089 
4090 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
4091 			defcsw = con->con;
4092 			break;
4093 		}
4094 	}
4095 
4096 	if (!defcsw)
4097 		goto err;
4098 
4099 	while (more) {
4100 		more = 0;
4101 
4102 		for (i = con->first; i <= con->last; i++) {
4103 			if (con_driver_map[i] == defcsw) {
4104 				if (first == -1)
4105 					first = i;
4106 				last = i;
4107 				more = 1;
4108 			} else if (first != -1)
4109 				break;
4110 		}
4111 
4112 		if (first == 0 && last == MAX_NR_CONSOLES -1)
4113 			deflt = 1;
4114 
4115 		if (first != -1)
4116 			do_bind_con_driver(csw, first, last, deflt);
4117 
4118 		first = -1;
4119 		last = -1;
4120 		deflt = 0;
4121 	}
4122 
4123 err:
4124 	return 0;
4125 }
4126 
4127 static int vt_unbind(struct con_driver *con)
4128 {
4129 	const struct consw *csw = NULL;
4130 	int i, more = 1, first = -1, last = -1, deflt = 0;
4131 	int ret;
4132 
4133  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
4134 		goto err;
4135 
4136 	csw = con->con;
4137 
4138 	while (more) {
4139 		more = 0;
4140 
4141 		for (i = con->first; i <= con->last; i++) {
4142 			if (con_driver_map[i] == csw) {
4143 				if (first == -1)
4144 					first = i;
4145 				last = i;
4146 				more = 1;
4147 			} else if (first != -1)
4148 				break;
4149 		}
4150 
4151 		if (first == 0 && last == MAX_NR_CONSOLES -1)
4152 			deflt = 1;
4153 
4154 		if (first != -1) {
4155 			ret = do_unbind_con_driver(csw, first, last, deflt);
4156 			if (ret != 0)
4157 				return ret;
4158 		}
4159 
4160 		first = -1;
4161 		last = -1;
4162 		deflt = 0;
4163 	}
4164 
4165 err:
4166 	return 0;
4167 }
4168 #else
4169 static inline int vt_bind(struct con_driver *con)
4170 {
4171 	return 0;
4172 }
4173 static inline int vt_unbind(struct con_driver *con)
4174 {
4175 	return 0;
4176 }
4177 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
4178 
4179 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
4180 			  const char *buf, size_t count)
4181 {
4182 	struct con_driver *con = dev_get_drvdata(dev);
4183 	int bind = simple_strtoul(buf, NULL, 0);
4184 
4185 	guard(console_lock)();
4186 
4187 	if (bind)
4188 		vt_bind(con);
4189 	else
4190 		vt_unbind(con);
4191 
4192 	return count;
4193 }
4194 
4195 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
4196 			 char *buf)
4197 {
4198 	struct con_driver *con = dev_get_drvdata(dev);
4199 	int bind;
4200 
4201 	scoped_guard(console_lock)
4202 		bind = con_is_bound(con->con);
4203 
4204 	return sysfs_emit(buf, "%i\n", bind);
4205 }
4206 
4207 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
4208 			 char *buf)
4209 {
4210 	struct con_driver *con = dev_get_drvdata(dev);
4211 
4212 	return sysfs_emit(buf, "%s %s\n",
4213 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
4214 			 con->desc);
4215 
4216 }
4217 
4218 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
4219 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
4220 
4221 static struct attribute *con_dev_attrs[] = {
4222 	&dev_attr_bind.attr,
4223 	&dev_attr_name.attr,
4224 	NULL
4225 };
4226 
4227 ATTRIBUTE_GROUPS(con_dev);
4228 
4229 static int vtconsole_init_device(struct con_driver *con)
4230 {
4231 	con->flag |= CON_DRIVER_FLAG_ATTR;
4232 	return 0;
4233 }
4234 
4235 static void vtconsole_deinit_device(struct con_driver *con)
4236 {
4237 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
4238 }
4239 
4240 /**
4241  * con_is_bound - checks if driver is bound to the console
4242  * @csw: console driver
4243  *
4244  * RETURNS: zero if unbound, nonzero if bound
4245  *
4246  * Drivers can call this and if zero, they should release
4247  * all resources allocated on &consw.con_startup()
4248  */
4249 int con_is_bound(const struct consw *csw)
4250 {
4251 	int i, bound = 0;
4252 
4253 	WARN_CONSOLE_UNLOCKED();
4254 
4255 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
4256 		if (con_driver_map[i] == csw) {
4257 			bound = 1;
4258 			break;
4259 		}
4260 	}
4261 
4262 	return bound;
4263 }
4264 EXPORT_SYMBOL(con_is_bound);
4265 
4266 /**
4267  * con_is_visible - checks whether the current console is visible
4268  * @vc: virtual console
4269  *
4270  * RETURNS: zero if not visible, nonzero if visible
4271  */
4272 bool con_is_visible(const struct vc_data *vc)
4273 {
4274 	WARN_CONSOLE_UNLOCKED();
4275 
4276 	return *vc->vc_display_fg == vc;
4277 }
4278 EXPORT_SYMBOL(con_is_visible);
4279 
4280 /**
4281  * con_debug_enter - prepare the console for the kernel debugger
4282  * @vc: virtual console
4283  *
4284  * Called when the console is taken over by the kernel debugger, this
4285  * function needs to save the current console state, then put the console
4286  * into a state suitable for the kernel debugger.
4287  */
4288 void con_debug_enter(struct vc_data *vc)
4289 {
4290 	saved_fg_console = fg_console;
4291 	saved_last_console = last_console;
4292 	saved_want_console = want_console;
4293 	saved_vc_mode = vc->vc_mode;
4294 	saved_console_blanked = console_blanked;
4295 	vc->vc_mode = KD_TEXT;
4296 	console_blanked = 0;
4297 	if (vc->vc_sw->con_debug_enter)
4298 		vc->vc_sw->con_debug_enter(vc);
4299 #ifdef CONFIG_KGDB_KDB
4300 	/* Set the initial LINES variable if it is not already set */
4301 	if (vc->vc_rows < 999) {
4302 		int linecount;
4303 		char lns[4];
4304 		const char *setargs[3] = {
4305 			"set",
4306 			"LINES",
4307 			lns,
4308 		};
4309 		if (kdbgetintenv(setargs[0], &linecount)) {
4310 			snprintf(lns, 4, "%i", vc->vc_rows);
4311 			kdb_set(2, setargs);
4312 		}
4313 	}
4314 	if (vc->vc_cols < 999) {
4315 		int colcount;
4316 		char cols[4];
4317 		const char *setargs[3] = {
4318 			"set",
4319 			"COLUMNS",
4320 			cols,
4321 		};
4322 		if (kdbgetintenv(setargs[0], &colcount)) {
4323 			snprintf(cols, 4, "%i", vc->vc_cols);
4324 			kdb_set(2, setargs);
4325 		}
4326 	}
4327 #endif /* CONFIG_KGDB_KDB */
4328 }
4329 EXPORT_SYMBOL_GPL(con_debug_enter);
4330 
4331 /**
4332  * con_debug_leave - restore console state
4333  *
4334  * Restore the console state to what it was before the kernel debugger
4335  * was invoked.
4336  */
4337 void con_debug_leave(void)
4338 {
4339 	struct vc_data *vc;
4340 
4341 	fg_console = saved_fg_console;
4342 	last_console = saved_last_console;
4343 	want_console = saved_want_console;
4344 	console_blanked = saved_console_blanked;
4345 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
4346 
4347 	vc = vc_cons[fg_console].d;
4348 	if (vc->vc_sw->con_debug_leave)
4349 		vc->vc_sw->con_debug_leave(vc);
4350 }
4351 EXPORT_SYMBOL_GPL(con_debug_leave);
4352 
4353 static int do_register_con_driver(const struct consw *csw, int first, int last)
4354 {
4355 	struct module *owner = csw->owner;
4356 	struct con_driver *con_driver;
4357 	const char *desc;
4358 	int i, retval;
4359 
4360 	WARN_CONSOLE_UNLOCKED();
4361 
4362 	if (!try_module_get(owner))
4363 		return -ENODEV;
4364 
4365 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4366 		con_driver = &registered_con_driver[i];
4367 
4368 		/* already registered */
4369 		if (con_driver->con == csw) {
4370 			retval = -EBUSY;
4371 			goto err;
4372 		}
4373 	}
4374 
4375 	desc = csw->con_startup();
4376 	if (!desc) {
4377 		retval = -ENODEV;
4378 		goto err;
4379 	}
4380 
4381 	retval = -EINVAL;
4382 
4383 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4384 		con_driver = &registered_con_driver[i];
4385 
4386 		if (con_driver->con == NULL &&
4387 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
4388 			con_driver->con = csw;
4389 			con_driver->desc = desc;
4390 			con_driver->node = i;
4391 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
4392 			                   CON_DRIVER_FLAG_INIT;
4393 			con_driver->first = first;
4394 			con_driver->last = last;
4395 			retval = 0;
4396 			break;
4397 		}
4398 	}
4399 
4400 	if (retval)
4401 		goto err;
4402 
4403 	con_driver->dev =
4404 		device_create_with_groups(&vtconsole_class, NULL,
4405 					  MKDEV(0, con_driver->node),
4406 					  con_driver, con_dev_groups,
4407 					  "vtcon%i", con_driver->node);
4408 	if (IS_ERR(con_driver->dev)) {
4409 		pr_warn("Unable to create device for %s; errno = %ld\n",
4410 			con_driver->desc, PTR_ERR(con_driver->dev));
4411 		con_driver->dev = NULL;
4412 	} else {
4413 		vtconsole_init_device(con_driver);
4414 	}
4415 
4416 err:
4417 	module_put(owner);
4418 	return retval;
4419 }
4420 
4421 
4422 /**
4423  * do_unregister_con_driver - unregister console driver from console layer
4424  * @csw: console driver
4425  *
4426  * DESCRIPTION: All drivers that registers to the console layer must
4427  * call this function upon exit, or if the console driver is in a state
4428  * where it won't be able to handle console services, such as the
4429  * framebuffer console without loaded framebuffer drivers.
4430  *
4431  * The driver must unbind first prior to unregistration.
4432  */
4433 int do_unregister_con_driver(const struct consw *csw)
4434 {
4435 	int i;
4436 
4437 	/* cannot unregister a bound driver */
4438 	if (con_is_bound(csw))
4439 		return -EBUSY;
4440 
4441 	if (csw == conswitchp)
4442 		return -EINVAL;
4443 
4444 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4445 		struct con_driver *con_driver = &registered_con_driver[i];
4446 
4447 		if (con_driver->con == csw) {
4448 			/*
4449 			 * Defer the removal of the sysfs entries since that
4450 			 * will acquire the kernfs s_active lock and we can't
4451 			 * acquire this lock while holding the console lock:
4452 			 * the unbind sysfs entry imposes already the opposite
4453 			 * order. Reset con already here to prevent any later
4454 			 * lookup to succeed and mark this slot as zombie, so
4455 			 * it won't get reused until we complete the removal
4456 			 * in the deferred work.
4457 			 */
4458 			con_driver->con = NULL;
4459 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4460 			schedule_work(&con_driver_unregister_work);
4461 
4462 			return 0;
4463 		}
4464 	}
4465 
4466 	return -ENODEV;
4467 }
4468 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4469 
4470 static void con_driver_unregister_callback(struct work_struct *ignored)
4471 {
4472 	int i;
4473 
4474 	guard(console_lock)();
4475 
4476 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4477 		struct con_driver *con_driver = &registered_con_driver[i];
4478 
4479 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4480 			continue;
4481 
4482 		console_unlock();
4483 
4484 		vtconsole_deinit_device(con_driver);
4485 		device_destroy(&vtconsole_class, MKDEV(0, con_driver->node));
4486 
4487 		console_lock();
4488 
4489 		if (WARN_ON_ONCE(con_driver->con))
4490 			con_driver->con = NULL;
4491 		con_driver->desc = NULL;
4492 		con_driver->dev = NULL;
4493 		con_driver->node = 0;
4494 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4495 		con_driver->flag = 0;
4496 		con_driver->first = 0;
4497 		con_driver->last = 0;
4498 	}
4499 }
4500 
4501 /*
4502  *	If we support more console drivers, this function is used
4503  *	when a driver wants to take over some existing consoles
4504  *	and become default driver for newly opened ones.
4505  *
4506  *	do_take_over_console is basically a register followed by bind
4507  */
4508 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4509 {
4510 	int err;
4511 
4512 	err = do_register_con_driver(csw, first, last);
4513 	/*
4514 	 * If we get an busy error we still want to bind the console driver
4515 	 * and return success, as we may have unbound the console driver
4516 	 * but not unregistered it.
4517 	 */
4518 	if (err == -EBUSY)
4519 		err = 0;
4520 	if (!err)
4521 		do_bind_con_driver(csw, first, last, deflt);
4522 
4523 	return err;
4524 }
4525 EXPORT_SYMBOL_GPL(do_take_over_console);
4526 
4527 
4528 /*
4529  * give_up_console is a wrapper to unregister_con_driver. It will only
4530  * work if driver is fully unbound.
4531  */
4532 void give_up_console(const struct consw *csw)
4533 {
4534 	guard(console_lock)();
4535 	do_unregister_con_driver(csw);
4536 }
4537 EXPORT_SYMBOL(give_up_console);
4538 
4539 static int __init vtconsole_class_init(void)
4540 {
4541 	int i;
4542 
4543 	i = class_register(&vtconsole_class);
4544 	if (i)
4545 		pr_warn("Unable to create vt console class; errno = %d\n", i);
4546 
4547 	/* Add system drivers to sysfs */
4548 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4549 		struct con_driver *con = &registered_con_driver[i];
4550 
4551 		if (con->con && !con->dev) {
4552 			con->dev =
4553 				device_create_with_groups(&vtconsole_class, NULL,
4554 							  MKDEV(0, con->node),
4555 							  con, con_dev_groups,
4556 							  "vtcon%i", con->node);
4557 
4558 			if (IS_ERR(con->dev)) {
4559 				pr_warn("Unable to create device for %s; errno = %ld\n",
4560 					con->desc, PTR_ERR(con->dev));
4561 				con->dev = NULL;
4562 			} else {
4563 				vtconsole_init_device(con);
4564 			}
4565 		}
4566 	}
4567 
4568 	return 0;
4569 }
4570 postcore_initcall(vtconsole_class_init);
4571 
4572 /*
4573  *	Screen blanking
4574  */
4575 
4576 static int set_vesa_blanking(u8 __user *mode_user)
4577 {
4578 	u8 mode;
4579 
4580 	if (get_user(mode, mode_user))
4581 		return -EFAULT;
4582 
4583 	guard(console_lock)();
4584 	vesa_blank_mode = (mode <= VESA_BLANK_MAX) ? mode : VESA_NO_BLANKING;
4585 
4586 	return 0;
4587 }
4588 
4589 void do_blank_screen(int entering_gfx)
4590 {
4591 	struct vc_data *vc = vc_cons[fg_console].d;
4592 	int i;
4593 
4594 	might_sleep();
4595 
4596 	WARN_CONSOLE_UNLOCKED();
4597 
4598 	if (console_blanked) {
4599 		if (blank_state == blank_vesa_wait) {
4600 			blank_state = blank_off;
4601 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4602 		}
4603 		return;
4604 	}
4605 
4606 	/* entering graphics mode? */
4607 	if (entering_gfx) {
4608 		hide_cursor(vc);
4609 		save_screen(vc);
4610 		vc->vc_sw->con_blank(vc, VESA_VSYNC_SUSPEND, 1);
4611 		console_blanked = fg_console + 1;
4612 		blank_state = blank_off;
4613 		set_origin(vc);
4614 		return;
4615 	}
4616 
4617 	blank_state = blank_off;
4618 
4619 	/* don't blank graphics */
4620 	if (vc->vc_mode != KD_TEXT) {
4621 		console_blanked = fg_console + 1;
4622 		return;
4623 	}
4624 
4625 	hide_cursor(vc);
4626 	timer_delete_sync(&console_timer);
4627 	blank_timer_expired = 0;
4628 
4629 	save_screen(vc);
4630 	/* In case we need to reset origin, blanking hook returns 1 */
4631 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? VESA_VSYNC_SUSPEND :
4632 				 (vesa_blank_mode + 1), 0);
4633 	console_blanked = fg_console + 1;
4634 	if (i)
4635 		set_origin(vc);
4636 
4637 	if (console_blank_hook && console_blank_hook(1))
4638 		return;
4639 
4640 	if (vesa_off_interval && vesa_blank_mode) {
4641 		blank_state = blank_vesa_wait;
4642 		mod_timer(&console_timer, jiffies + vesa_off_interval);
4643 	}
4644 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4645 }
4646 EXPORT_SYMBOL(do_blank_screen);
4647 
4648 /*
4649  * Called by timer as well as from vt_console_driver
4650  */
4651 void do_unblank_screen(int leaving_gfx)
4652 {
4653 	struct vc_data *vc;
4654 
4655 	/* This should now always be called from a "sane" (read: can schedule)
4656 	 * context for the sake of the low level drivers, except in the special
4657 	 * case of oops_in_progress
4658 	 */
4659 	if (!oops_in_progress)
4660 		might_sleep();
4661 
4662 	WARN_CONSOLE_UNLOCKED();
4663 
4664 	ignore_poke = 0;
4665 	if (!console_blanked)
4666 		return;
4667 	if (!vc_cons_allocated(fg_console)) {
4668 		/* impossible */
4669 		pr_warn("unblank_screen: tty %d not allocated ??\n",
4670 			fg_console + 1);
4671 		return;
4672 	}
4673 	vc = vc_cons[fg_console].d;
4674 	if (vc->vc_mode != KD_TEXT)
4675 		return; /* but leave console_blanked != 0 */
4676 
4677 	if (blankinterval) {
4678 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4679 		blank_state = blank_normal_wait;
4680 	}
4681 
4682 	console_blanked = 0;
4683 	if (vc->vc_sw->con_blank(vc, VESA_NO_BLANKING, leaving_gfx))
4684 		/* Low-level driver cannot restore -> do it ourselves */
4685 		update_screen(vc);
4686 	if (console_blank_hook)
4687 		console_blank_hook(0);
4688 	set_palette(vc);
4689 	set_cursor(vc);
4690 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4691 	notify_update(vc);
4692 }
4693 EXPORT_SYMBOL(do_unblank_screen);
4694 
4695 /*
4696  * This is called by the outside world to cause a forced unblank, mostly for
4697  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4698  * call it with 1 as an argument and so force a mode restore... that may kill
4699  * X or at least garbage the screen but would also make the Oops visible...
4700  */
4701 static void unblank_screen(void)
4702 {
4703 	do_unblank_screen(0);
4704 }
4705 
4706 /*
4707  * We defer the timer blanking to work queue so it can take the console mutex
4708  * (console operations can still happen at irq time, but only from printk which
4709  * has the console mutex. Not perfect yet, but better than no locking
4710  */
4711 static void blank_screen_t(struct timer_list *unused)
4712 {
4713 	blank_timer_expired = 1;
4714 	schedule_work(&console_work);
4715 }
4716 
4717 void poke_blanked_console(void)
4718 {
4719 	WARN_CONSOLE_UNLOCKED();
4720 
4721 	/* Add this so we quickly catch whoever might call us in a non
4722 	 * safe context. Nowadays, unblank_screen() isn't to be called in
4723 	 * atomic contexts and is allowed to schedule (with the special case
4724 	 * of oops_in_progress, but that isn't of any concern for this
4725 	 * function. --BenH.
4726 	 */
4727 	might_sleep();
4728 
4729 	/* This isn't perfectly race free, but a race here would be mostly harmless,
4730 	 * at worst, we'll do a spurious blank and it's unlikely
4731 	 */
4732 	timer_delete(&console_timer);
4733 	blank_timer_expired = 0;
4734 
4735 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4736 		return;
4737 	if (console_blanked)
4738 		unblank_screen();
4739 	else if (blankinterval) {
4740 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4741 		blank_state = blank_normal_wait;
4742 	}
4743 }
4744 
4745 /*
4746  *	Palettes
4747  */
4748 
4749 static void set_palette(struct vc_data *vc)
4750 {
4751 	WARN_CONSOLE_UNLOCKED();
4752 
4753 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4754 		vc->vc_sw->con_set_palette(vc, color_table);
4755 }
4756 
4757 /*
4758  * Load palette into the DAC registers. arg points to a colour
4759  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4760  */
4761 
4762 int con_set_cmap(unsigned char __user *arg)
4763 {
4764 	int i, j, k;
4765 	unsigned char colormap[3*16];
4766 
4767 	if (copy_from_user(colormap, arg, sizeof(colormap)))
4768 		return -EFAULT;
4769 
4770 	guard(console_lock)();
4771 	for (i = k = 0; i < 16; i++) {
4772 		default_red[i] = colormap[k++];
4773 		default_grn[i] = colormap[k++];
4774 		default_blu[i] = colormap[k++];
4775 	}
4776 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
4777 		if (!vc_cons_allocated(i))
4778 			continue;
4779 		for (j = k = 0; j < 16; j++) {
4780 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4781 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4782 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4783 		}
4784 		set_palette(vc_cons[i].d);
4785 	}
4786 
4787 	return 0;
4788 }
4789 
4790 int con_get_cmap(unsigned char __user *arg)
4791 {
4792 	int i, k;
4793 	unsigned char colormap[3*16];
4794 
4795 	scoped_guard(console_lock)
4796 		for (i = k = 0; i < 16; i++) {
4797 			colormap[k++] = default_red[i];
4798 			colormap[k++] = default_grn[i];
4799 			colormap[k++] = default_blu[i];
4800 		}
4801 
4802 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4803 		return -EFAULT;
4804 
4805 	return 0;
4806 }
4807 
4808 void reset_palette(struct vc_data *vc)
4809 {
4810 	int j, k;
4811 	for (j=k=0; j<16; j++) {
4812 		vc->vc_palette[k++] = default_red[j];
4813 		vc->vc_palette[k++] = default_grn[j];
4814 		vc->vc_palette[k++] = default_blu[j];
4815 	}
4816 	set_palette(vc);
4817 }
4818 
4819 /*
4820  *  Font switching
4821  *
4822  *  Currently we only support fonts up to 128 pixels wide, at a maximum height
4823  *  of 128 pixels. Userspace fontdata may have to be stored with 32 bytes
4824  *  (shorts/ints, depending on width) reserved for each character which is
4825  *  kinda wasty, but this is done in order to maintain compatibility with the
4826  *  EGA/VGA fonts. It is up to the actual low-level console-driver convert data
4827  *  into its favorite format (maybe we should add a `fontoffset' field to the
4828  *  `display' structure so we won't have to convert the fontdata all the time.
4829  *  /Jes
4830  */
4831 
4832 #define max_font_width	64
4833 #define max_font_height	128
4834 #define max_font_glyphs	512
4835 #define max_font_size	(max_font_glyphs*max_font_width*max_font_height)
4836 
4837 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4838 {
4839 	struct console_font font;
4840 	int c;
4841 	unsigned int vpitch = op->op == KD_FONT_OP_GET_TALL ? op->height : 32;
4842 
4843 	if (vpitch > max_font_height)
4844 		return -EINVAL;
4845 
4846 	void *font_data __free(kvfree) = NULL;
4847 	if (op->data) {
4848 		font.data = font_data = kvzalloc(max_font_size, GFP_KERNEL);
4849 		if (!font.data)
4850 			return -ENOMEM;
4851 	} else
4852 		font.data = NULL;
4853 
4854 	scoped_guard(console_lock) {
4855 		if (vc->vc_mode != KD_TEXT)
4856 			return -EINVAL;
4857 		if (!vc->vc_sw->con_font_get)
4858 			return -ENOSYS;
4859 
4860 		int ret = vc->vc_sw->con_font_get(vc, &font, vpitch);
4861 		if (ret)
4862 			return ret;
4863 	}
4864 
4865 	c = (font.width+7)/8 * vpitch * font.charcount;
4866 
4867 	if (op->data && font.charcount > op->charcount)
4868 		return -ENOSPC;
4869 	if (font.width > op->width || font.height > op->height)
4870 		return -ENOSPC;
4871 
4872 	op->height = font.height;
4873 	op->width = font.width;
4874 	op->charcount = font.charcount;
4875 
4876 	if (op->data && copy_to_user(op->data, font.data, c))
4877 		return -EFAULT;
4878 
4879 	return 0;
4880 }
4881 
4882 static int con_font_set(struct vc_data *vc, const struct console_font_op *op)
4883 {
4884 	struct console_font font;
4885 	int size;
4886 	unsigned int vpitch = op->op == KD_FONT_OP_SET_TALL ? op->height : 32;
4887 
4888 	if (!op->data)
4889 		return -EINVAL;
4890 	if (op->charcount > max_font_glyphs)
4891 		return -EINVAL;
4892 	if (op->width <= 0 || op->width > max_font_width || !op->height ||
4893 	    op->height > max_font_height)
4894 		return -EINVAL;
4895 	if (vpitch < op->height)
4896 		return -EINVAL;
4897 	size = (op->width+7)/8 * vpitch * op->charcount;
4898 	if (size > max_font_size)
4899 		return -ENOSPC;
4900 
4901 	void *font_data __free(kfree) = font.data = memdup_user(op->data, size);
4902 	if (IS_ERR(font.data))
4903 		return PTR_ERR(font.data);
4904 
4905 	font.charcount = op->charcount;
4906 	font.width = op->width;
4907 	font.height = op->height;
4908 
4909 	guard(console_lock)();
4910 
4911 	if (vc->vc_mode != KD_TEXT)
4912 		return -EINVAL;
4913 	if (!vc->vc_sw->con_font_set)
4914 		return -ENOSYS;
4915 
4916 	if (vc_is_sel(vc))
4917 		clear_selection();
4918 
4919 	return vc->vc_sw->con_font_set(vc, &font, vpitch, op->flags);
4920 }
4921 
4922 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4923 {
4924 	struct console_font font = {.width = op->width, .height = op->height};
4925 	char name[MAX_FONT_NAME];
4926 	char *s = name;
4927 
4928 	if (!op->data)
4929 		s = NULL;
4930 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4931 		return -EFAULT;
4932 	else
4933 		name[MAX_FONT_NAME - 1] = 0;
4934 
4935 	scoped_guard(console_lock) {
4936 		if (vc->vc_mode != KD_TEXT)
4937 			return -EINVAL;
4938 		if (!vc->vc_sw->con_font_default)
4939 			return -ENOSYS;
4940 
4941 		if (vc_is_sel(vc))
4942 			clear_selection();
4943 		int ret = vc->vc_sw->con_font_default(vc, &font, s);
4944 		if (ret)
4945 			return ret;
4946 	}
4947 
4948 	op->width = font.width;
4949 	op->height = font.height;
4950 
4951 	return 0;
4952 }
4953 
4954 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4955 {
4956 	switch (op->op) {
4957 	case KD_FONT_OP_SET:
4958 	case KD_FONT_OP_SET_TALL:
4959 		return con_font_set(vc, op);
4960 	case KD_FONT_OP_GET:
4961 	case KD_FONT_OP_GET_TALL:
4962 		return con_font_get(vc, op);
4963 	case KD_FONT_OP_SET_DEFAULT:
4964 		return con_font_default(vc, op);
4965 	case KD_FONT_OP_COPY:
4966 		/* was buggy and never really used */
4967 		return -EINVAL;
4968 	}
4969 	return -ENOSYS;
4970 }
4971 
4972 /*
4973  *	Interface exported to selection and vcs.
4974  */
4975 
4976 /* used by selection */
4977 u16 screen_glyph(const struct vc_data *vc, int offset)
4978 {
4979 	u16 w = scr_readw(screenpos(vc, offset, true));
4980 	u16 c = w & 0xff;
4981 
4982 	if (w & vc->vc_hi_font_mask)
4983 		c |= 0x100;
4984 	return c;
4985 }
4986 EXPORT_SYMBOL_GPL(screen_glyph);
4987 
4988 u32 screen_glyph_unicode(const struct vc_data *vc, int n)
4989 {
4990 	u32 **uni_lines = vc->vc_uni_lines;
4991 
4992 	if (uni_lines)
4993 		return uni_lines[n / vc->vc_cols][n % vc->vc_cols];
4994 
4995 	return inverse_translate(vc, screen_glyph(vc, n * 2), true);
4996 }
4997 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4998 
4999 /* used by vcs - note the word offset */
5000 unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
5001 {
5002 	return screenpos(vc, 2 * w_offset, viewed);
5003 }
5004 EXPORT_SYMBOL_GPL(screen_pos);
5005 
5006 void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
5007 {
5008 	/* clamp values if they don't fit */
5009 	xy[0] = min(vc->state.x, 0xFFu);
5010 	xy[1] = min(vc->state.y, 0xFFu);
5011 }
5012 
5013 void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
5014 {
5015 	hide_cursor(vc);
5016 	gotoxy(vc, xy[0], xy[1]);
5017 	set_cursor(vc);
5018 }
5019 
5020 u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
5021 {
5022 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
5023 		return softcursor_original;
5024 	return scr_readw(org);
5025 }
5026 
5027 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
5028 {
5029 	scr_writew(val, org);
5030 	if ((unsigned long)org == vc->vc_pos) {
5031 		softcursor_original = -1;
5032 		add_softcursor(vc);
5033 	}
5034 }
5035 
5036 void vcs_scr_updated(struct vc_data *vc)
5037 {
5038 	notify_update(vc);
5039 }
5040