xref: /linux/drivers/tty/vt/vt.c (revision 1f2367a39f17bd553a75e179a747f9b257bc9478)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 1991, 1992  Linus Torvalds
4  */
5 
6 /*
7  * Hopefully this will be a rather complete VT102 implementation.
8  *
9  * Beeping thanks to John T Kohl.
10  *
11  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
12  *   Chars, and VT100 enhancements by Peter MacDonald.
13  *
14  * Copy and paste function by Andrew Haylett,
15  *   some enhancements by Alessandro Rubini.
16  *
17  * Code to check for different video-cards mostly by Galen Hunt,
18  * <g-hunt@ee.utah.edu>
19  *
20  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
21  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
22  *
23  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
24  * Resizing of consoles, aeb, 940926
25  *
26  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
27  * <poe@daimi.aau.dk>
28  *
29  * User-defined bell sound, new setterm control sequences and printk
30  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
31  *
32  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
33  *
34  * Merge with the abstract console driver by Geert Uytterhoeven
35  * <geert@linux-m68k.org>, Jan 1997.
36  *
37  *   Original m68k console driver modifications by
38  *
39  *     - Arno Griffioen <arno@usn.nl>
40  *     - David Carter <carter@cs.bris.ac.uk>
41  *
42  *   The abstract console driver provides a generic interface for a text
43  *   console. It supports VGA text mode, frame buffer based graphical consoles
44  *   and special graphics processors that are only accessible through some
45  *   registers (e.g. a TMS340x0 GSP).
46  *
47  *   The interface to the hardware is specified using a special structure
48  *   (struct consw) which contains function pointers to console operations
49  *   (see <linux/console.h> for more information).
50  *
51  * Support for changeable cursor shape
52  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
53  *
54  * Ported to i386 and con_scrolldelta fixed
55  * by Emmanuel Marty <core@ggi-project.org>, April 1998
56  *
57  * Resurrected character buffers in videoram plus lots of other trickery
58  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
59  *
60  * Removed old-style timers, introduced console_timer, made timer
61  * deletion SMP-safe.  17Jun00, Andrew Morton
62  *
63  * Removed console_lock, enabled interrupts across all console operations
64  * 13 March 2001, Andrew Morton
65  *
66  * Fixed UTF-8 mode so alternate charset modes always work according
67  * to control sequences interpreted in do_con_trol function
68  * preserving backward VT100 semigraphics compatibility,
69  * malformed UTF sequences represented as sequences of replacement glyphs,
70  * original codes or '?' as a last resort if replacement glyph is undefined
71  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
72  */
73 
74 #include <linux/module.h>
75 #include <linux/types.h>
76 #include <linux/sched/signal.h>
77 #include <linux/tty.h>
78 #include <linux/tty_flip.h>
79 #include <linux/kernel.h>
80 #include <linux/string.h>
81 #include <linux/errno.h>
82 #include <linux/kd.h>
83 #include <linux/slab.h>
84 #include <linux/major.h>
85 #include <linux/mm.h>
86 #include <linux/console.h>
87 #include <linux/init.h>
88 #include <linux/mutex.h>
89 #include <linux/vt_kern.h>
90 #include <linux/selection.h>
91 #include <linux/tiocl.h>
92 #include <linux/kbd_kern.h>
93 #include <linux/consolemap.h>
94 #include <linux/timer.h>
95 #include <linux/interrupt.h>
96 #include <linux/workqueue.h>
97 #include <linux/pm.h>
98 #include <linux/font.h>
99 #include <linux/bitops.h>
100 #include <linux/notifier.h>
101 #include <linux/device.h>
102 #include <linux/io.h>
103 #include <linux/uaccess.h>
104 #include <linux/kdb.h>
105 #include <linux/ctype.h>
106 #include <linux/bsearch.h>
107 #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 /* A bitmap for codes <32. A bit of 1 indicates that the code
130  * corresponding to that bit number invokes some special action
131  * (such as cursor movement) and should not be displayed as a
132  * glyph unless the disp_ctrl mode is explicitly enabled.
133  */
134 #define CTRL_ACTION 0x0d00ff81
135 #define CTRL_ALWAYS 0x0800f501	/* Cannot be overridden by disp_ctrl */
136 
137 /*
138  * Here is the default bell parameters: 750HZ, 1/8th of a second
139  */
140 #define DEFAULT_BELL_PITCH	750
141 #define DEFAULT_BELL_DURATION	(HZ/8)
142 #define DEFAULT_CURSOR_BLINK_MS	200
143 
144 struct vc vc_cons [MAX_NR_CONSOLES];
145 
146 #ifndef VT_SINGLE_DRIVER
147 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
148 #endif
149 
150 static int con_open(struct tty_struct *, struct file *);
151 static void vc_init(struct vc_data *vc, unsigned int rows,
152 		    unsigned int cols, int do_clear);
153 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
154 static void save_cur(struct vc_data *vc);
155 static void reset_terminal(struct vc_data *vc, int do_clear);
156 static void con_flush_chars(struct tty_struct *tty);
157 static int set_vesa_blanking(char __user *p);
158 static void set_cursor(struct vc_data *vc);
159 static void hide_cursor(struct vc_data *vc);
160 static void console_callback(struct work_struct *ignored);
161 static void con_driver_unregister_callback(struct work_struct *ignored);
162 static void blank_screen_t(struct timer_list *unused);
163 static void set_palette(struct vc_data *vc);
164 
165 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
166 
167 static int printable;		/* Is console ready for printing? */
168 int default_utf8 = true;
169 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
170 int global_cursor_default = -1;
171 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
172 
173 static int cur_default = CUR_DEFAULT;
174 module_param(cur_default, int, S_IRUGO | S_IWUSR);
175 
176 /*
177  * ignore_poke: don't unblank the screen when things are typed.  This is
178  * mainly for the privacy of braille terminal users.
179  */
180 static int ignore_poke;
181 
182 int do_poke_blanked_console;
183 int console_blanked;
184 
185 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
186 static int vesa_off_interval;
187 static int blankinterval;
188 core_param(consoleblank, blankinterval, int, 0444);
189 
190 static DECLARE_WORK(console_work, console_callback);
191 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
192 
193 /*
194  * fg_console is the current virtual console,
195  * last_console is the last used one,
196  * want_console is the console we want to switch to,
197  * saved_* variants are for save/restore around kernel debugger enter/leave
198  */
199 int fg_console;
200 int last_console;
201 int want_console = -1;
202 static int saved_fg_console;
203 static int saved_last_console;
204 static int saved_want_console;
205 static int saved_vc_mode;
206 static int saved_console_blanked;
207 
208 /*
209  * For each existing display, we have a pointer to console currently visible
210  * on that display, allowing consoles other than fg_console to be refreshed
211  * appropriately. Unless the low-level driver supplies its own display_fg
212  * variable, we use this one for the "master display".
213  */
214 static struct vc_data *master_display_fg;
215 
216 /*
217  * Unfortunately, we need to delay tty echo when we're currently writing to the
218  * console since the code is (and always was) not re-entrant, so we schedule
219  * all flip requests to process context with schedule-task() and run it from
220  * console_callback().
221  */
222 
223 /*
224  * For the same reason, we defer scrollback to the console callback.
225  */
226 static int scrollback_delta;
227 
228 /*
229  * Hook so that the power management routines can (un)blank
230  * the console on our behalf.
231  */
232 int (*console_blank_hook)(int);
233 
234 static DEFINE_TIMER(console_timer, blank_screen_t);
235 static int blank_state;
236 static int blank_timer_expired;
237 enum {
238 	blank_off = 0,
239 	blank_normal_wait,
240 	blank_vesa_wait,
241 };
242 
243 /*
244  * /sys/class/tty/tty0/
245  *
246  * the attribute 'active' contains the name of the current vc
247  * console and it supports poll() to detect vc switches
248  */
249 static struct device *tty0dev;
250 
251 /*
252  * Notifier list for console events.
253  */
254 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
255 
256 int register_vt_notifier(struct notifier_block *nb)
257 {
258 	return atomic_notifier_chain_register(&vt_notifier_list, nb);
259 }
260 EXPORT_SYMBOL_GPL(register_vt_notifier);
261 
262 int unregister_vt_notifier(struct notifier_block *nb)
263 {
264 	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
265 }
266 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
267 
268 static void notify_write(struct vc_data *vc, unsigned int unicode)
269 {
270 	struct vt_notifier_param param = { .vc = vc, .c = unicode };
271 	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
272 }
273 
274 static void notify_update(struct vc_data *vc)
275 {
276 	struct vt_notifier_param param = { .vc = vc };
277 	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
278 }
279 /*
280  *	Low-Level Functions
281  */
282 
283 static inline bool con_is_fg(const struct vc_data *vc)
284 {
285 	return vc->vc_num == fg_console;
286 }
287 
288 static inline bool con_should_update(const struct vc_data *vc)
289 {
290 	return con_is_visible(vc) && !console_blanked;
291 }
292 
293 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
294 {
295 	unsigned short *p;
296 
297 	if (!viewed)
298 		p = (unsigned short *)(vc->vc_origin + offset);
299 	else if (!vc->vc_sw->con_screen_pos)
300 		p = (unsigned short *)(vc->vc_visible_origin + offset);
301 	else
302 		p = vc->vc_sw->con_screen_pos(vc, offset);
303 	return p;
304 }
305 
306 /* Called  from the keyboard irq path.. */
307 static inline void scrolldelta(int lines)
308 {
309 	/* FIXME */
310 	/* scrolldelta needs some kind of consistency lock, but the BKL was
311 	   and still is not protecting versus the scheduled back end */
312 	scrollback_delta += lines;
313 	schedule_console_callback();
314 }
315 
316 void schedule_console_callback(void)
317 {
318 	schedule_work(&console_work);
319 }
320 
321 /*
322  * Code to manage unicode-based screen buffers
323  */
324 
325 #ifdef NO_VC_UNI_SCREEN
326 /* this disables and optimizes related code away at compile time */
327 #define get_vc_uniscr(vc) NULL
328 #else
329 #define get_vc_uniscr(vc) vc->vc_uni_screen
330 #endif
331 
332 #define VC_UNI_SCREEN_DEBUG 0
333 
334 typedef uint32_t char32_t;
335 
336 /*
337  * Our screen buffer is preceded by an array of line pointers so that
338  * scrolling only implies some pointer shuffling.
339  */
340 struct uni_screen {
341 	char32_t *lines[0];
342 };
343 
344 static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
345 {
346 	struct uni_screen *uniscr;
347 	void *p;
348 	unsigned int memsize, i;
349 
350 	/* allocate everything in one go */
351 	memsize = cols * rows * sizeof(char32_t);
352 	memsize += rows * sizeof(char32_t *);
353 	p = kmalloc(memsize, GFP_KERNEL);
354 	if (!p)
355 		return NULL;
356 
357 	/* initial line pointers */
358 	uniscr = p;
359 	p = uniscr->lines + rows;
360 	for (i = 0; i < rows; i++) {
361 		uniscr->lines[i] = p;
362 		p += cols * sizeof(char32_t);
363 	}
364 	return uniscr;
365 }
366 
367 static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
368 {
369 	kfree(vc->vc_uni_screen);
370 	vc->vc_uni_screen = new_uniscr;
371 }
372 
373 static void vc_uniscr_putc(struct vc_data *vc, char32_t uc)
374 {
375 	struct uni_screen *uniscr = get_vc_uniscr(vc);
376 
377 	if (uniscr)
378 		uniscr->lines[vc->vc_y][vc->vc_x] = uc;
379 }
380 
381 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
382 {
383 	struct uni_screen *uniscr = get_vc_uniscr(vc);
384 
385 	if (uniscr) {
386 		char32_t *ln = uniscr->lines[vc->vc_y];
387 		unsigned int x = vc->vc_x, cols = vc->vc_cols;
388 
389 		memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
390 		memset32(&ln[x], ' ', nr);
391 	}
392 }
393 
394 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
395 {
396 	struct uni_screen *uniscr = get_vc_uniscr(vc);
397 
398 	if (uniscr) {
399 		char32_t *ln = uniscr->lines[vc->vc_y];
400 		unsigned int x = vc->vc_x, cols = vc->vc_cols;
401 
402 		memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
403 		memset32(&ln[cols - nr], ' ', nr);
404 	}
405 }
406 
407 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
408 				 unsigned int nr)
409 {
410 	struct uni_screen *uniscr = get_vc_uniscr(vc);
411 
412 	if (uniscr) {
413 		char32_t *ln = uniscr->lines[vc->vc_y];
414 
415 		memset32(&ln[x], ' ', nr);
416 	}
417 }
418 
419 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
420 				  unsigned int nr)
421 {
422 	struct uni_screen *uniscr = get_vc_uniscr(vc);
423 
424 	if (uniscr) {
425 		unsigned int cols = vc->vc_cols;
426 
427 		while (nr--)
428 			memset32(uniscr->lines[y++], ' ', cols);
429 	}
430 }
431 
432 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
433 			     enum con_scroll dir, unsigned int nr)
434 {
435 	struct uni_screen *uniscr = get_vc_uniscr(vc);
436 
437 	if (uniscr) {
438 		unsigned int i, j, k, sz, d, clear;
439 
440 		sz = b - t;
441 		clear = b - nr;
442 		d = nr;
443 		if (dir == SM_DOWN) {
444 			clear = t;
445 			d = sz - nr;
446 		}
447 		for (i = 0; i < gcd(d, sz); i++) {
448 			char32_t *tmp = uniscr->lines[t + i];
449 			j = i;
450 			while (1) {
451 				k = j + d;
452 				if (k >= sz)
453 					k -= sz;
454 				if (k == i)
455 					break;
456 				uniscr->lines[t + j] = uniscr->lines[t + k];
457 				j = k;
458 			}
459 			uniscr->lines[t + j] = tmp;
460 		}
461 		vc_uniscr_clear_lines(vc, clear, nr);
462 	}
463 }
464 
465 static void vc_uniscr_copy_area(struct uni_screen *dst,
466 				unsigned int dst_cols,
467 				unsigned int dst_rows,
468 				struct uni_screen *src,
469 				unsigned int src_cols,
470 				unsigned int src_top_row,
471 				unsigned int src_bot_row)
472 {
473 	unsigned int dst_row = 0;
474 
475 	if (!dst)
476 		return;
477 
478 	while (src_top_row < src_bot_row) {
479 		char32_t *src_line = src->lines[src_top_row];
480 		char32_t *dst_line = dst->lines[dst_row];
481 
482 		memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
483 		if (dst_cols - src_cols)
484 			memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
485 		src_top_row++;
486 		dst_row++;
487 	}
488 	while (dst_row < dst_rows) {
489 		char32_t *dst_line = dst->lines[dst_row];
490 
491 		memset32(dst_line, ' ', dst_cols);
492 		dst_row++;
493 	}
494 }
495 
496 /*
497  * Called from vcs_read() to make sure unicode screen retrieval is possible.
498  * This will initialize the unicode screen buffer if not already done.
499  * This returns 0 if OK, or a negative error code otherwise.
500  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
501  */
502 int vc_uniscr_check(struct vc_data *vc)
503 {
504 	struct uni_screen *uniscr;
505 	unsigned short *p;
506 	int x, y, mask;
507 
508 	if (__is_defined(NO_VC_UNI_SCREEN))
509 		return -EOPNOTSUPP;
510 
511 	WARN_CONSOLE_UNLOCKED();
512 
513 	if (!vc->vc_utf)
514 		return -ENODATA;
515 
516 	if (vc->vc_uni_screen)
517 		return 0;
518 
519 	uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
520 	if (!uniscr)
521 		return -ENOMEM;
522 
523 	/*
524 	 * Let's populate it initially with (imperfect) reverse translation.
525 	 * This is the next best thing we can do short of having it enabled
526 	 * from the start even when no users rely on this functionality. True
527 	 * unicode content will be available after a complete screen refresh.
528 	 */
529 	p = (unsigned short *)vc->vc_origin;
530 	mask = vc->vc_hi_font_mask | 0xff;
531 	for (y = 0; y < vc->vc_rows; y++) {
532 		char32_t *line = uniscr->lines[y];
533 		for (x = 0; x < vc->vc_cols; x++) {
534 			u16 glyph = scr_readw(p++) & mask;
535 			line[x] = inverse_translate(vc, glyph, true);
536 		}
537 	}
538 
539 	vc->vc_uni_screen = uniscr;
540 	return 0;
541 }
542 
543 /*
544  * Called from vcs_read() to get the unicode data from the screen.
545  * This must be preceded by a successful call to vc_uniscr_check() once
546  * the console lock has been taken.
547  */
548 void vc_uniscr_copy_line(struct vc_data *vc, void *dest, int viewed,
549 			 unsigned int row, unsigned int col, unsigned int nr)
550 {
551 	struct uni_screen *uniscr = get_vc_uniscr(vc);
552 	int offset = row * vc->vc_size_row + col * 2;
553 	unsigned long pos;
554 
555 	BUG_ON(!uniscr);
556 
557 	pos = (unsigned long)screenpos(vc, offset, viewed);
558 	if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
559 		/*
560 		 * Desired position falls in the main screen buffer.
561 		 * However the actual row/col might be different if
562 		 * scrollback is active.
563 		 */
564 		row = (pos - vc->vc_origin) / vc->vc_size_row;
565 		col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
566 		memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t));
567 	} else {
568 		/*
569 		 * Scrollback is active. For now let's simply backtranslate
570 		 * the screen glyphs until the unicode screen buffer does
571 		 * synchronize with console display drivers for a scrollback
572 		 * buffer of its own.
573 		 */
574 		u16 *p = (u16 *)pos;
575 		int mask = vc->vc_hi_font_mask | 0xff;
576 		char32_t *uni_buf = dest;
577 		while (nr--) {
578 			u16 glyph = scr_readw(p++) & mask;
579 			*uni_buf++ = inverse_translate(vc, glyph, true);
580 		}
581 	}
582 }
583 
584 /* this is for validation and debugging only */
585 static void vc_uniscr_debug_check(struct vc_data *vc)
586 {
587 	struct uni_screen *uniscr = get_vc_uniscr(vc);
588 	unsigned short *p;
589 	int x, y, mask;
590 
591 	if (!VC_UNI_SCREEN_DEBUG || !uniscr)
592 		return;
593 
594 	WARN_CONSOLE_UNLOCKED();
595 
596 	/*
597 	 * Make sure our unicode screen translates into the same glyphs
598 	 * as the actual screen. This is brutal indeed.
599 	 */
600 	p = (unsigned short *)vc->vc_origin;
601 	mask = vc->vc_hi_font_mask | 0xff;
602 	for (y = 0; y < vc->vc_rows; y++) {
603 		char32_t *line = uniscr->lines[y];
604 		for (x = 0; x < vc->vc_cols; x++) {
605 			u16 glyph = scr_readw(p++) & mask;
606 			char32_t uc = line[x];
607 			int tc = conv_uni_to_pc(vc, uc);
608 			if (tc == -4)
609 				tc = conv_uni_to_pc(vc, 0xfffd);
610 			if (tc == -4)
611 				tc = conv_uni_to_pc(vc, '?');
612 			if (tc != glyph)
613 				pr_err_ratelimited(
614 					"%s: mismatch at %d,%d: glyph=%#x tc=%#x\n",
615 					__func__, x, y, glyph, tc);
616 		}
617 	}
618 }
619 
620 
621 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
622 		enum con_scroll dir, unsigned int nr)
623 {
624 	u16 *clear, *d, *s;
625 
626 	if (t + nr >= b)
627 		nr = b - t - 1;
628 	if (b > vc->vc_rows || t >= b || nr < 1)
629 		return;
630 	vc_uniscr_scroll(vc, t, b, dir, nr);
631 	if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
632 		return;
633 
634 	s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
635 	d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
636 
637 	if (dir == SM_UP) {
638 		clear = s + (b - t - nr) * vc->vc_cols;
639 		swap(s, d);
640 	}
641 	scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
642 	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
643 }
644 
645 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
646 {
647 	unsigned int xx, yy, offset;
648 	u16 *p;
649 
650 	p = (u16 *) start;
651 	if (!vc->vc_sw->con_getxy) {
652 		offset = (start - vc->vc_origin) / 2;
653 		xx = offset % vc->vc_cols;
654 		yy = offset / vc->vc_cols;
655 	} else {
656 		int nxx, nyy;
657 		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
658 		xx = nxx; yy = nyy;
659 	}
660 	for(;;) {
661 		u16 attrib = scr_readw(p) & 0xff00;
662 		int startx = xx;
663 		u16 *q = p;
664 		while (xx < vc->vc_cols && count) {
665 			if (attrib != (scr_readw(p) & 0xff00)) {
666 				if (p > q)
667 					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
668 				startx = xx;
669 				q = p;
670 				attrib = scr_readw(p) & 0xff00;
671 			}
672 			p++;
673 			xx++;
674 			count--;
675 		}
676 		if (p > q)
677 			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
678 		if (!count)
679 			break;
680 		xx = 0;
681 		yy++;
682 		if (vc->vc_sw->con_getxy) {
683 			p = (u16 *)start;
684 			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
685 		}
686 	}
687 }
688 
689 void update_region(struct vc_data *vc, unsigned long start, int count)
690 {
691 	WARN_CONSOLE_UNLOCKED();
692 
693 	if (con_should_update(vc)) {
694 		hide_cursor(vc);
695 		do_update_region(vc, start, count);
696 		set_cursor(vc);
697 	}
698 }
699 
700 /* Structure of attributes is hardware-dependent */
701 
702 static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
703     u8 _underline, u8 _reverse, u8 _italic)
704 {
705 	if (vc->vc_sw->con_build_attr)
706 		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
707 		       _blink, _underline, _reverse, _italic);
708 
709 /*
710  * ++roman: I completely changed the attribute format for monochrome
711  * mode (!can_do_color). The formerly used MDA (monochrome display
712  * adapter) format didn't allow the combination of certain effects.
713  * Now the attribute is just a bit vector:
714  *  Bit 0..1: intensity (0..2)
715  *  Bit 2   : underline
716  *  Bit 3   : reverse
717  *  Bit 7   : blink
718  */
719 	{
720 	u8 a = _color;
721 	if (!vc->vc_can_do_color)
722 		return _intensity |
723 		       (_italic ? 2 : 0) |
724 		       (_underline ? 4 : 0) |
725 		       (_reverse ? 8 : 0) |
726 		       (_blink ? 0x80 : 0);
727 	if (_italic)
728 		a = (a & 0xF0) | vc->vc_itcolor;
729 	else if (_underline)
730 		a = (a & 0xf0) | vc->vc_ulcolor;
731 	else if (_intensity == 0)
732 		a = (a & 0xf0) | vc->vc_halfcolor;
733 	if (_reverse)
734 		a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
735 	if (_blink)
736 		a ^= 0x80;
737 	if (_intensity == 2)
738 		a ^= 0x08;
739 	if (vc->vc_hi_font_mask == 0x100)
740 		a <<= 1;
741 	return a;
742 	}
743 }
744 
745 static void update_attr(struct vc_data *vc)
746 {
747 	vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
748 	              vc->vc_blink, vc->vc_underline,
749 	              vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
750 	vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
751 }
752 
753 /* Note: inverting the screen twice should revert to the original state */
754 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
755 {
756 	unsigned short *p;
757 
758 	WARN_CONSOLE_UNLOCKED();
759 
760 	count /= 2;
761 	p = screenpos(vc, offset, viewed);
762 	if (vc->vc_sw->con_invert_region) {
763 		vc->vc_sw->con_invert_region(vc, p, count);
764 	} else {
765 		u16 *q = p;
766 		int cnt = count;
767 		u16 a;
768 
769 		if (!vc->vc_can_do_color) {
770 			while (cnt--) {
771 			    a = scr_readw(q);
772 			    a ^= 0x0800;
773 			    scr_writew(a, q);
774 			    q++;
775 			}
776 		} else if (vc->vc_hi_font_mask == 0x100) {
777 			while (cnt--) {
778 				a = scr_readw(q);
779 				a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
780 				scr_writew(a, q);
781 				q++;
782 			}
783 		} else {
784 			while (cnt--) {
785 				a = scr_readw(q);
786 				a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
787 				scr_writew(a, q);
788 				q++;
789 			}
790 		}
791 	}
792 
793 	if (con_should_update(vc))
794 		do_update_region(vc, (unsigned long) p, count);
795 	notify_update(vc);
796 }
797 
798 /* used by selection: complement pointer position */
799 void complement_pos(struct vc_data *vc, int offset)
800 {
801 	static int old_offset = -1;
802 	static unsigned short old;
803 	static unsigned short oldx, oldy;
804 
805 	WARN_CONSOLE_UNLOCKED();
806 
807 	if (old_offset != -1 && old_offset >= 0 &&
808 	    old_offset < vc->vc_screenbuf_size) {
809 		scr_writew(old, screenpos(vc, old_offset, 1));
810 		if (con_should_update(vc))
811 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
812 		notify_update(vc);
813 	}
814 
815 	old_offset = offset;
816 
817 	if (offset != -1 && offset >= 0 &&
818 	    offset < vc->vc_screenbuf_size) {
819 		unsigned short new;
820 		unsigned short *p;
821 		p = screenpos(vc, offset, 1);
822 		old = scr_readw(p);
823 		new = old ^ vc->vc_complement_mask;
824 		scr_writew(new, p);
825 		if (con_should_update(vc)) {
826 			oldx = (offset >> 1) % vc->vc_cols;
827 			oldy = (offset >> 1) / vc->vc_cols;
828 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
829 		}
830 		notify_update(vc);
831 	}
832 }
833 
834 static void insert_char(struct vc_data *vc, unsigned int nr)
835 {
836 	unsigned short *p = (unsigned short *) vc->vc_pos;
837 
838 	vc_uniscr_insert(vc, nr);
839 	scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
840 	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
841 	vc->vc_need_wrap = 0;
842 	if (con_should_update(vc))
843 		do_update_region(vc, (unsigned long) p,
844 			vc->vc_cols - vc->vc_x);
845 }
846 
847 static void delete_char(struct vc_data *vc, unsigned int nr)
848 {
849 	unsigned short *p = (unsigned short *) vc->vc_pos;
850 
851 	vc_uniscr_delete(vc, nr);
852 	scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
853 	scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
854 			nr * 2);
855 	vc->vc_need_wrap = 0;
856 	if (con_should_update(vc))
857 		do_update_region(vc, (unsigned long) p,
858 			vc->vc_cols - vc->vc_x);
859 }
860 
861 static int softcursor_original = -1;
862 
863 static void add_softcursor(struct vc_data *vc)
864 {
865 	int i = scr_readw((u16 *) vc->vc_pos);
866 	u32 type = vc->vc_cursor_type;
867 
868 	if (! (type & 0x10)) return;
869 	if (softcursor_original != -1) return;
870 	softcursor_original = i;
871 	i |= ((type >> 8) & 0xff00 );
872 	i ^= ((type) & 0xff00 );
873 	if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
874 	if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
875 	scr_writew(i, (u16 *) vc->vc_pos);
876 	if (con_should_update(vc))
877 		vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
878 }
879 
880 static void hide_softcursor(struct vc_data *vc)
881 {
882 	if (softcursor_original != -1) {
883 		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
884 		if (con_should_update(vc))
885 			vc->vc_sw->con_putc(vc, softcursor_original,
886 					vc->vc_y, vc->vc_x);
887 		softcursor_original = -1;
888 	}
889 }
890 
891 static void hide_cursor(struct vc_data *vc)
892 {
893 	if (vc == sel_cons)
894 		clear_selection();
895 	vc->vc_sw->con_cursor(vc, CM_ERASE);
896 	hide_softcursor(vc);
897 }
898 
899 static void set_cursor(struct vc_data *vc)
900 {
901 	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
902 		return;
903 	if (vc->vc_deccm) {
904 		if (vc == sel_cons)
905 			clear_selection();
906 		add_softcursor(vc);
907 		if ((vc->vc_cursor_type & 0x0f) != 1)
908 			vc->vc_sw->con_cursor(vc, CM_DRAW);
909 	} else
910 		hide_cursor(vc);
911 }
912 
913 static void set_origin(struct vc_data *vc)
914 {
915 	WARN_CONSOLE_UNLOCKED();
916 
917 	if (!con_is_visible(vc) ||
918 	    !vc->vc_sw->con_set_origin ||
919 	    !vc->vc_sw->con_set_origin(vc))
920 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
921 	vc->vc_visible_origin = vc->vc_origin;
922 	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
923 	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
924 }
925 
926 static void save_screen(struct vc_data *vc)
927 {
928 	WARN_CONSOLE_UNLOCKED();
929 
930 	if (vc->vc_sw->con_save_screen)
931 		vc->vc_sw->con_save_screen(vc);
932 }
933 
934 static void flush_scrollback(struct vc_data *vc)
935 {
936 	WARN_CONSOLE_UNLOCKED();
937 
938 	set_origin(vc);
939 	if (vc->vc_sw->con_flush_scrollback)
940 		vc->vc_sw->con_flush_scrollback(vc);
941 	else
942 		vc->vc_sw->con_switch(vc);
943 }
944 
945 /*
946  *	Redrawing of screen
947  */
948 
949 void clear_buffer_attributes(struct vc_data *vc)
950 {
951 	unsigned short *p = (unsigned short *)vc->vc_origin;
952 	int count = vc->vc_screenbuf_size / 2;
953 	int mask = vc->vc_hi_font_mask | 0xff;
954 
955 	for (; count > 0; count--, p++) {
956 		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
957 	}
958 }
959 
960 void redraw_screen(struct vc_data *vc, int is_switch)
961 {
962 	int redraw = 0;
963 
964 	WARN_CONSOLE_UNLOCKED();
965 
966 	if (!vc) {
967 		/* strange ... */
968 		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
969 		return;
970 	}
971 
972 	if (is_switch) {
973 		struct vc_data *old_vc = vc_cons[fg_console].d;
974 		if (old_vc == vc)
975 			return;
976 		if (!con_is_visible(vc))
977 			redraw = 1;
978 		*vc->vc_display_fg = vc;
979 		fg_console = vc->vc_num;
980 		hide_cursor(old_vc);
981 		if (!con_is_visible(old_vc)) {
982 			save_screen(old_vc);
983 			set_origin(old_vc);
984 		}
985 		if (tty0dev)
986 			sysfs_notify(&tty0dev->kobj, NULL, "active");
987 	} else {
988 		hide_cursor(vc);
989 		redraw = 1;
990 	}
991 
992 	if (redraw) {
993 		int update;
994 		int old_was_color = vc->vc_can_do_color;
995 
996 		set_origin(vc);
997 		update = vc->vc_sw->con_switch(vc);
998 		set_palette(vc);
999 		/*
1000 		 * If console changed from mono<->color, the best we can do
1001 		 * is to clear the buffer attributes. As it currently stands,
1002 		 * rebuilding new attributes from the old buffer is not doable
1003 		 * without overly complex code.
1004 		 */
1005 		if (old_was_color != vc->vc_can_do_color) {
1006 			update_attr(vc);
1007 			clear_buffer_attributes(vc);
1008 		}
1009 
1010 		if (update && vc->vc_mode != KD_GRAPHICS)
1011 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1012 	}
1013 	set_cursor(vc);
1014 	if (is_switch) {
1015 		set_leds();
1016 		compute_shiftstate();
1017 		notify_update(vc);
1018 	}
1019 }
1020 
1021 /*
1022  *	Allocation, freeing and resizing of VTs.
1023  */
1024 
1025 int vc_cons_allocated(unsigned int i)
1026 {
1027 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1028 }
1029 
1030 static void visual_init(struct vc_data *vc, int num, int init)
1031 {
1032 	/* ++Geert: vc->vc_sw->con_init determines console size */
1033 	if (vc->vc_sw)
1034 		module_put(vc->vc_sw->owner);
1035 	vc->vc_sw = conswitchp;
1036 #ifndef VT_SINGLE_DRIVER
1037 	if (con_driver_map[num])
1038 		vc->vc_sw = con_driver_map[num];
1039 #endif
1040 	__module_get(vc->vc_sw->owner);
1041 	vc->vc_num = num;
1042 	vc->vc_display_fg = &master_display_fg;
1043 	if (vc->vc_uni_pagedir_loc)
1044 		con_free_unimap(vc);
1045 	vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
1046 	vc->vc_uni_pagedir = NULL;
1047 	vc->vc_hi_font_mask = 0;
1048 	vc->vc_complement_mask = 0;
1049 	vc->vc_can_do_color = 0;
1050 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1051 	vc->vc_sw->con_init(vc, init);
1052 	if (!vc->vc_complement_mask)
1053 		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1054 	vc->vc_s_complement_mask = vc->vc_complement_mask;
1055 	vc->vc_size_row = vc->vc_cols << 1;
1056 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1057 }
1058 
1059 int vc_allocate(unsigned int currcons)	/* return 0 on success */
1060 {
1061 	struct vt_notifier_param param;
1062 	struct vc_data *vc;
1063 
1064 	WARN_CONSOLE_UNLOCKED();
1065 
1066 	if (currcons >= MAX_NR_CONSOLES)
1067 		return -ENXIO;
1068 
1069 	if (vc_cons[currcons].d)
1070 		return 0;
1071 
1072 	/* due to the granularity of kmalloc, we waste some memory here */
1073 	/* the alloc is done in two steps, to optimize the common situation
1074 	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
1075 	/* although the numbers above are not valid since long ago, the
1076 	   point is still up-to-date and the comment still has its value
1077 	   even if only as a historical artifact.  --mj, July 1998 */
1078 	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1079 	if (!vc)
1080 		return -ENOMEM;
1081 
1082 	vc_cons[currcons].d = vc;
1083 	tty_port_init(&vc->port);
1084 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1085 
1086 	visual_init(vc, currcons, 1);
1087 
1088 	if (!*vc->vc_uni_pagedir_loc)
1089 		con_set_default_unimap(vc);
1090 
1091 	vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1092 	if (!vc->vc_screenbuf)
1093 		goto err_free;
1094 
1095 	/* If no drivers have overridden us and the user didn't pass a
1096 	   boot option, default to displaying the cursor */
1097 	if (global_cursor_default == -1)
1098 		global_cursor_default = 1;
1099 
1100 	vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
1101 	vcs_make_sysfs(currcons);
1102 	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1103 
1104 	return 0;
1105 err_free:
1106 	kfree(vc);
1107 	vc_cons[currcons].d = NULL;
1108 	return -ENOMEM;
1109 }
1110 
1111 static inline int resize_screen(struct vc_data *vc, int width, int height,
1112 				int user)
1113 {
1114 	/* Resizes the resolution of the display adapater */
1115 	int err = 0;
1116 
1117 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
1118 		err = vc->vc_sw->con_resize(vc, width, height, user);
1119 
1120 	return err;
1121 }
1122 
1123 /*
1124  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1125  * [this is to be used together with some user program
1126  * like resize that changes the hardware videomode]
1127  */
1128 #define VC_RESIZE_MAXCOL (32767)
1129 #define VC_RESIZE_MAXROW (32767)
1130 
1131 /**
1132  *	vc_do_resize	-	resizing method for the tty
1133  *	@tty: tty being resized
1134  *	@real_tty: real tty (different to tty if a pty/tty pair)
1135  *	@vc: virtual console private data
1136  *	@cols: columns
1137  *	@lines: lines
1138  *
1139  *	Resize a virtual console, clipping according to the actual constraints.
1140  *	If the caller passes a tty structure then update the termios winsize
1141  *	information and perform any necessary signal handling.
1142  *
1143  *	Caller must hold the console semaphore. Takes the termios rwsem and
1144  *	ctrl_lock of the tty IFF a tty is passed.
1145  */
1146 
1147 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1148 				unsigned int cols, unsigned int lines)
1149 {
1150 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1151 	unsigned long end;
1152 	unsigned int old_rows, old_row_size, first_copied_row;
1153 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1154 	unsigned int user;
1155 	unsigned short *newscreen;
1156 	struct uni_screen *new_uniscr = NULL;
1157 
1158 	WARN_CONSOLE_UNLOCKED();
1159 
1160 	if (!vc)
1161 		return -ENXIO;
1162 
1163 	user = vc->vc_resize_user;
1164 	vc->vc_resize_user = 0;
1165 
1166 	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
1167 		return -EINVAL;
1168 
1169 	new_cols = (cols ? cols : vc->vc_cols);
1170 	new_rows = (lines ? lines : vc->vc_rows);
1171 	new_row_size = new_cols << 1;
1172 	new_screen_size = new_row_size * new_rows;
1173 
1174 	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
1175 		return 0;
1176 
1177 	if (new_screen_size > (4 << 20))
1178 		return -EINVAL;
1179 	newscreen = kzalloc(new_screen_size, GFP_USER);
1180 	if (!newscreen)
1181 		return -ENOMEM;
1182 
1183 	if (get_vc_uniscr(vc)) {
1184 		new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1185 		if (!new_uniscr) {
1186 			kfree(newscreen);
1187 			return -ENOMEM;
1188 		}
1189 	}
1190 
1191 	if (vc == sel_cons)
1192 		clear_selection();
1193 
1194 	old_rows = vc->vc_rows;
1195 	old_row_size = vc->vc_size_row;
1196 
1197 	err = resize_screen(vc, new_cols, new_rows, user);
1198 	if (err) {
1199 		kfree(newscreen);
1200 		kfree(new_uniscr);
1201 		return err;
1202 	}
1203 
1204 	vc->vc_rows = new_rows;
1205 	vc->vc_cols = new_cols;
1206 	vc->vc_size_row = new_row_size;
1207 	vc->vc_screenbuf_size = new_screen_size;
1208 
1209 	rlth = min(old_row_size, new_row_size);
1210 	rrem = new_row_size - rlth;
1211 	old_origin = vc->vc_origin;
1212 	new_origin = (long) newscreen;
1213 	new_scr_end = new_origin + new_screen_size;
1214 
1215 	if (vc->vc_y > new_rows) {
1216 		if (old_rows - vc->vc_y < new_rows) {
1217 			/*
1218 			 * Cursor near the bottom, copy contents from the
1219 			 * bottom of buffer
1220 			 */
1221 			first_copied_row = (old_rows - new_rows);
1222 		} else {
1223 			/*
1224 			 * Cursor is in no man's land, copy 1/2 screenful
1225 			 * from the top and bottom of cursor position
1226 			 */
1227 			first_copied_row = (vc->vc_y - new_rows/2);
1228 		}
1229 		old_origin += first_copied_row * old_row_size;
1230 	} else
1231 		first_copied_row = 0;
1232 	end = old_origin + old_row_size * min(old_rows, new_rows);
1233 
1234 	vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1235 			    get_vc_uniscr(vc), rlth/2, first_copied_row,
1236 			    min(old_rows, new_rows));
1237 	vc_uniscr_set(vc, new_uniscr);
1238 
1239 	update_attr(vc);
1240 
1241 	while (old_origin < end) {
1242 		scr_memcpyw((unsigned short *) new_origin,
1243 			    (unsigned short *) old_origin, rlth);
1244 		if (rrem)
1245 			scr_memsetw((void *)(new_origin + rlth),
1246 				    vc->vc_video_erase_char, rrem);
1247 		old_origin += old_row_size;
1248 		new_origin += new_row_size;
1249 	}
1250 	if (new_scr_end > new_origin)
1251 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1252 			    new_scr_end - new_origin);
1253 	kfree(vc->vc_screenbuf);
1254 	vc->vc_screenbuf = newscreen;
1255 	vc->vc_screenbuf_size = new_screen_size;
1256 	set_origin(vc);
1257 
1258 	/* do part of a reset_terminal() */
1259 	vc->vc_top = 0;
1260 	vc->vc_bottom = vc->vc_rows;
1261 	gotoxy(vc, vc->vc_x, vc->vc_y);
1262 	save_cur(vc);
1263 
1264 	if (tty) {
1265 		/* Rewrite the requested winsize data with the actual
1266 		   resulting sizes */
1267 		struct winsize ws;
1268 		memset(&ws, 0, sizeof(ws));
1269 		ws.ws_row = vc->vc_rows;
1270 		ws.ws_col = vc->vc_cols;
1271 		ws.ws_ypixel = vc->vc_scan_lines;
1272 		tty_do_resize(tty, &ws);
1273 	}
1274 
1275 	if (con_is_visible(vc))
1276 		update_screen(vc);
1277 	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1278 	notify_update(vc);
1279 	return err;
1280 }
1281 
1282 /**
1283  *	vc_resize		-	resize a VT
1284  *	@vc: virtual console
1285  *	@cols: columns
1286  *	@rows: rows
1287  *
1288  *	Resize a virtual console as seen from the console end of things. We
1289  *	use the common vc_do_resize methods to update the structures. The
1290  *	caller must hold the console sem to protect console internals and
1291  *	vc->port.tty
1292  */
1293 
1294 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1295 {
1296 	return vc_do_resize(vc->port.tty, vc, cols, rows);
1297 }
1298 
1299 /**
1300  *	vt_resize		-	resize a VT
1301  *	@tty: tty to resize
1302  *	@ws: winsize attributes
1303  *
1304  *	Resize a virtual terminal. This is called by the tty layer as we
1305  *	register our own handler for resizing. The mutual helper does all
1306  *	the actual work.
1307  *
1308  *	Takes the console sem and the called methods then take the tty
1309  *	termios_rwsem and the tty ctrl_lock in that order.
1310  */
1311 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1312 {
1313 	struct vc_data *vc = tty->driver_data;
1314 	int ret;
1315 
1316 	console_lock();
1317 	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1318 	console_unlock();
1319 	return ret;
1320 }
1321 
1322 struct vc_data *vc_deallocate(unsigned int currcons)
1323 {
1324 	struct vc_data *vc = NULL;
1325 
1326 	WARN_CONSOLE_UNLOCKED();
1327 
1328 	if (vc_cons_allocated(currcons)) {
1329 		struct vt_notifier_param param;
1330 
1331 		param.vc = vc = vc_cons[currcons].d;
1332 		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1333 		vcs_remove_sysfs(currcons);
1334 		vc->vc_sw->con_deinit(vc);
1335 		put_pid(vc->vt_pid);
1336 		module_put(vc->vc_sw->owner);
1337 		vc_uniscr_set(vc, NULL);
1338 		kfree(vc->vc_screenbuf);
1339 		vc_cons[currcons].d = NULL;
1340 	}
1341 	return vc;
1342 }
1343 
1344 /*
1345  *	VT102 emulator
1346  */
1347 
1348 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1349 
1350 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1351 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1352 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1353 
1354 #define decarm		VC_REPEAT
1355 #define decckm		VC_CKMODE
1356 #define kbdapplic	VC_APPLIC
1357 #define lnm		VC_CRLF
1358 
1359 /*
1360  * this is what the terminal answers to a ESC-Z or csi0c query.
1361  */
1362 #define VT100ID "\033[?1;2c"
1363 #define VT102ID "\033[?6c"
1364 
1365 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1366 				       8,12,10,14, 9,13,11,15 };
1367 
1368 /* the default colour table, for VGA+ colour systems */
1369 unsigned char default_red[] = {
1370 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1371 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1372 };
1373 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1374 
1375 unsigned char default_grn[] = {
1376 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1377 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1378 };
1379 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1380 
1381 unsigned char default_blu[] = {
1382 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1383 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1384 };
1385 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1386 
1387 /*
1388  * gotoxy() must verify all boundaries, because the arguments
1389  * might also be negative. If the given position is out of
1390  * bounds, the cursor is placed at the nearest margin.
1391  */
1392 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1393 {
1394 	int min_y, max_y;
1395 
1396 	if (new_x < 0)
1397 		vc->vc_x = 0;
1398 	else {
1399 		if (new_x >= vc->vc_cols)
1400 			vc->vc_x = vc->vc_cols - 1;
1401 		else
1402 			vc->vc_x = new_x;
1403 	}
1404 
1405  	if (vc->vc_decom) {
1406 		min_y = vc->vc_top;
1407 		max_y = vc->vc_bottom;
1408 	} else {
1409 		min_y = 0;
1410 		max_y = vc->vc_rows;
1411 	}
1412 	if (new_y < min_y)
1413 		vc->vc_y = min_y;
1414 	else if (new_y >= max_y)
1415 		vc->vc_y = max_y - 1;
1416 	else
1417 		vc->vc_y = new_y;
1418 	vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
1419 	vc->vc_need_wrap = 0;
1420 }
1421 
1422 /* for absolute user moves, when decom is set */
1423 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1424 {
1425 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1426 }
1427 
1428 void scrollback(struct vc_data *vc)
1429 {
1430 	scrolldelta(-(vc->vc_rows / 2));
1431 }
1432 
1433 void scrollfront(struct vc_data *vc, int lines)
1434 {
1435 	if (!lines)
1436 		lines = vc->vc_rows / 2;
1437 	scrolldelta(lines);
1438 }
1439 
1440 static void lf(struct vc_data *vc)
1441 {
1442     	/* don't scroll if above bottom of scrolling region, or
1443 	 * if below scrolling region
1444 	 */
1445     	if (vc->vc_y + 1 == vc->vc_bottom)
1446 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1447 	else if (vc->vc_y < vc->vc_rows - 1) {
1448 	    	vc->vc_y++;
1449 		vc->vc_pos += vc->vc_size_row;
1450 	}
1451 	vc->vc_need_wrap = 0;
1452 	notify_write(vc, '\n');
1453 }
1454 
1455 static void ri(struct vc_data *vc)
1456 {
1457     	/* don't scroll if below top of scrolling region, or
1458 	 * if above scrolling region
1459 	 */
1460 	if (vc->vc_y == vc->vc_top)
1461 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1462 	else if (vc->vc_y > 0) {
1463 		vc->vc_y--;
1464 		vc->vc_pos -= vc->vc_size_row;
1465 	}
1466 	vc->vc_need_wrap = 0;
1467 }
1468 
1469 static inline void cr(struct vc_data *vc)
1470 {
1471 	vc->vc_pos -= vc->vc_x << 1;
1472 	vc->vc_need_wrap = vc->vc_x = 0;
1473 	notify_write(vc, '\r');
1474 }
1475 
1476 static inline void bs(struct vc_data *vc)
1477 {
1478 	if (vc->vc_x) {
1479 		vc->vc_pos -= 2;
1480 		vc->vc_x--;
1481 		vc->vc_need_wrap = 0;
1482 		notify_write(vc, '\b');
1483 	}
1484 }
1485 
1486 static inline void del(struct vc_data *vc)
1487 {
1488 	/* ignored */
1489 }
1490 
1491 static void csi_J(struct vc_data *vc, int vpar)
1492 {
1493 	unsigned int count;
1494 	unsigned short * start;
1495 
1496 	switch (vpar) {
1497 		case 0:	/* erase from cursor to end of display */
1498 			vc_uniscr_clear_line(vc, vc->vc_x,
1499 					     vc->vc_cols - vc->vc_x);
1500 			vc_uniscr_clear_lines(vc, vc->vc_y + 1,
1501 					      vc->vc_rows - vc->vc_y - 1);
1502 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1503 			start = (unsigned short *)vc->vc_pos;
1504 			break;
1505 		case 1:	/* erase from start to cursor */
1506 			vc_uniscr_clear_line(vc, 0, vc->vc_x + 1);
1507 			vc_uniscr_clear_lines(vc, 0, vc->vc_y);
1508 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1509 			start = (unsigned short *)vc->vc_origin;
1510 			break;
1511 		case 3: /* include scrollback */
1512 			flush_scrollback(vc);
1513 			/* fallthrough */
1514 		case 2: /* erase whole display */
1515 			vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1516 			count = vc->vc_cols * vc->vc_rows;
1517 			start = (unsigned short *)vc->vc_origin;
1518 			break;
1519 		default:
1520 			return;
1521 	}
1522 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1523 	update_region(vc, (unsigned long) start, count);
1524 	vc->vc_need_wrap = 0;
1525 }
1526 
1527 static void csi_K(struct vc_data *vc, int vpar)
1528 {
1529 	unsigned int count;
1530 	unsigned short *start = (unsigned short *)vc->vc_pos;
1531 	int offset;
1532 
1533 	switch (vpar) {
1534 		case 0:	/* erase from cursor to end of line */
1535 			offset = 0;
1536 			count = vc->vc_cols - vc->vc_x;
1537 			break;
1538 		case 1:	/* erase from start of line to cursor */
1539 			offset = -vc->vc_x;
1540 			count = vc->vc_x + 1;
1541 			break;
1542 		case 2: /* erase whole line */
1543 			offset = -vc->vc_x;
1544 			count = vc->vc_cols;
1545 			break;
1546 		default:
1547 			return;
1548 	}
1549 	vc_uniscr_clear_line(vc, vc->vc_x + offset, count);
1550 	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1551 	vc->vc_need_wrap = 0;
1552 	if (con_should_update(vc))
1553 		do_update_region(vc, (unsigned long)(start + offset), count);
1554 }
1555 
1556 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1557 {					  /* not vt100? */
1558 	int count;
1559 
1560 	if (!vpar)
1561 		vpar++;
1562 	count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
1563 
1564 	vc_uniscr_clear_line(vc, vc->vc_x, count);
1565 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1566 	if (con_should_update(vc))
1567 		vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
1568 	vc->vc_need_wrap = 0;
1569 }
1570 
1571 static void default_attr(struct vc_data *vc)
1572 {
1573 	vc->vc_intensity = 1;
1574 	vc->vc_italic = 0;
1575 	vc->vc_underline = 0;
1576 	vc->vc_reverse = 0;
1577 	vc->vc_blink = 0;
1578 	vc->vc_color = vc->vc_def_color;
1579 }
1580 
1581 struct rgb { u8 r; u8 g; u8 b; };
1582 
1583 static void rgb_from_256(int i, struct rgb *c)
1584 {
1585 	if (i < 8) {            /* Standard colours. */
1586 		c->r = i&1 ? 0xaa : 0x00;
1587 		c->g = i&2 ? 0xaa : 0x00;
1588 		c->b = i&4 ? 0xaa : 0x00;
1589 	} else if (i < 16) {
1590 		c->r = i&1 ? 0xff : 0x55;
1591 		c->g = i&2 ? 0xff : 0x55;
1592 		c->b = i&4 ? 0xff : 0x55;
1593 	} else if (i < 232) {   /* 6x6x6 colour cube. */
1594 		c->r = (i - 16) / 36 * 85 / 2;
1595 		c->g = (i - 16) / 6 % 6 * 85 / 2;
1596 		c->b = (i - 16) % 6 * 85 / 2;
1597 	} else                  /* Grayscale ramp. */
1598 		c->r = c->g = c->b = i * 10 - 2312;
1599 }
1600 
1601 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1602 {
1603 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1604 
1605 	if (c->r > max / 2)
1606 		hue |= 4;
1607 	if (c->g > max / 2)
1608 		hue |= 2;
1609 	if (c->b > max / 2)
1610 		hue |= 1;
1611 
1612 	if (hue == 7 && max <= 0x55) {
1613 		hue = 0;
1614 		vc->vc_intensity = 2;
1615 	} else if (max > 0xaa)
1616 		vc->vc_intensity = 2;
1617 	else
1618 		vc->vc_intensity = 1;
1619 
1620 	vc->vc_color = (vc->vc_color & 0xf0) | hue;
1621 }
1622 
1623 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1624 {
1625 	/* For backgrounds, err on the dark side. */
1626 	vc->vc_color = (vc->vc_color & 0x0f)
1627 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1628 }
1629 
1630 /*
1631  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1632  * and thus need to be detected and ignored by hand. That standard also
1633  * wants : rather than ; as separators but sequences containing : are currently
1634  * completely ignored by the parser.
1635  *
1636  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1637  * supporting them.
1638  */
1639 static int vc_t416_color(struct vc_data *vc, int i,
1640 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1641 {
1642 	struct rgb c;
1643 
1644 	i++;
1645 	if (i > vc->vc_npar)
1646 		return i;
1647 
1648 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1649 		/* 256 colours */
1650 		i++;
1651 		rgb_from_256(vc->vc_par[i], &c);
1652 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1653 		/* 24 bit */
1654 		c.r = vc->vc_par[i + 1];
1655 		c.g = vc->vc_par[i + 2];
1656 		c.b = vc->vc_par[i + 3];
1657 		i += 3;
1658 	} else
1659 		return i;
1660 
1661 	set_color(vc, &c);
1662 
1663 	return i;
1664 }
1665 
1666 /* console_lock is held */
1667 static void csi_m(struct vc_data *vc)
1668 {
1669 	int i;
1670 
1671 	for (i = 0; i <= vc->vc_npar; i++)
1672 		switch (vc->vc_par[i]) {
1673 		case 0:	/* all attributes off */
1674 			default_attr(vc);
1675 			break;
1676 		case 1:
1677 			vc->vc_intensity = 2;
1678 			break;
1679 		case 2:
1680 			vc->vc_intensity = 0;
1681 			break;
1682 		case 3:
1683 			vc->vc_italic = 1;
1684 			break;
1685 		case 21:
1686 			/*
1687 			 * No console drivers support double underline, so
1688 			 * convert it to a single underline.
1689 			 */
1690 		case 4:
1691 			vc->vc_underline = 1;
1692 			break;
1693 		case 5:
1694 			vc->vc_blink = 1;
1695 			break;
1696 		case 7:
1697 			vc->vc_reverse = 1;
1698 			break;
1699 		case 10: /* ANSI X3.64-1979 (SCO-ish?)
1700 			  * Select primary font, don't display control chars if
1701 			  * defined, don't set bit 8 on output.
1702 			  */
1703 			vc->vc_translate = set_translate(vc->vc_charset == 0
1704 					? vc->vc_G0_charset
1705 					: vc->vc_G1_charset, vc);
1706 			vc->vc_disp_ctrl = 0;
1707 			vc->vc_toggle_meta = 0;
1708 			break;
1709 		case 11: /* ANSI X3.64-1979 (SCO-ish?)
1710 			  * Select first alternate font, lets chars < 32 be
1711 			  * displayed as ROM chars.
1712 			  */
1713 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1714 			vc->vc_disp_ctrl = 1;
1715 			vc->vc_toggle_meta = 0;
1716 			break;
1717 		case 12: /* ANSI X3.64-1979 (SCO-ish?)
1718 			  * Select second alternate font, toggle high bit
1719 			  * before displaying as ROM char.
1720 			  */
1721 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1722 			vc->vc_disp_ctrl = 1;
1723 			vc->vc_toggle_meta = 1;
1724 			break;
1725 		case 22:
1726 			vc->vc_intensity = 1;
1727 			break;
1728 		case 23:
1729 			vc->vc_italic = 0;
1730 			break;
1731 		case 24:
1732 			vc->vc_underline = 0;
1733 			break;
1734 		case 25:
1735 			vc->vc_blink = 0;
1736 			break;
1737 		case 27:
1738 			vc->vc_reverse = 0;
1739 			break;
1740 		case 38:
1741 			i = vc_t416_color(vc, i, rgb_foreground);
1742 			break;
1743 		case 48:
1744 			i = vc_t416_color(vc, i, rgb_background);
1745 			break;
1746 		case 39:
1747 			vc->vc_color = (vc->vc_def_color & 0x0f) |
1748 				(vc->vc_color & 0xf0);
1749 			break;
1750 		case 49:
1751 			vc->vc_color = (vc->vc_def_color & 0xf0) |
1752 				(vc->vc_color & 0x0f);
1753 			break;
1754 		default:
1755 			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1756 				if (vc->vc_par[i] < 100)
1757 					vc->vc_intensity = 2;
1758 				vc->vc_par[i] -= 60;
1759 			}
1760 			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1761 				vc->vc_color = color_table[vc->vc_par[i] - 30]
1762 					| (vc->vc_color & 0xf0);
1763 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1764 				vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1765 					| (vc->vc_color & 0x0f);
1766 			break;
1767 		}
1768 	update_attr(vc);
1769 }
1770 
1771 static void respond_string(const char *p, struct tty_port *port)
1772 {
1773 	while (*p) {
1774 		tty_insert_flip_char(port, *p, 0);
1775 		p++;
1776 	}
1777 	tty_schedule_flip(port);
1778 }
1779 
1780 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1781 {
1782 	char buf[40];
1783 
1784 	sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1785 	respond_string(buf, tty->port);
1786 }
1787 
1788 static inline void status_report(struct tty_struct *tty)
1789 {
1790 	respond_string("\033[0n", tty->port);	/* Terminal ok */
1791 }
1792 
1793 static inline void respond_ID(struct tty_struct *tty)
1794 {
1795 	respond_string(VT102ID, tty->port);
1796 }
1797 
1798 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1799 {
1800 	char buf[8];
1801 
1802 	sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1803 		(char)('!' + mry));
1804 	respond_string(buf, tty->port);
1805 }
1806 
1807 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1808 int mouse_reporting(void)
1809 {
1810 	return vc_cons[fg_console].d->vc_report_mouse;
1811 }
1812 
1813 /* console_lock is held */
1814 static void set_mode(struct vc_data *vc, int on_off)
1815 {
1816 	int i;
1817 
1818 	for (i = 0; i <= vc->vc_npar; i++)
1819 		if (vc->vc_priv == EPdec) {
1820 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1821 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1822 				if (on_off)
1823 					set_kbd(vc, decckm);
1824 				else
1825 					clr_kbd(vc, decckm);
1826 				break;
1827 			case 3:	/* 80/132 mode switch unimplemented */
1828 #if 0
1829 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1830 				/* this alone does not suffice; some user mode
1831 				   utility has to change the hardware regs */
1832 #endif
1833 				break;
1834 			case 5:			/* Inverted screen on/off */
1835 				if (vc->vc_decscnm != on_off) {
1836 					vc->vc_decscnm = on_off;
1837 					invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1838 					update_attr(vc);
1839 				}
1840 				break;
1841 			case 6:			/* Origin relative/absolute */
1842 				vc->vc_decom = on_off;
1843 				gotoxay(vc, 0, 0);
1844 				break;
1845 			case 7:			/* Autowrap on/off */
1846 				vc->vc_decawm = on_off;
1847 				break;
1848 			case 8:			/* Autorepeat on/off */
1849 				if (on_off)
1850 					set_kbd(vc, decarm);
1851 				else
1852 					clr_kbd(vc, decarm);
1853 				break;
1854 			case 9:
1855 				vc->vc_report_mouse = on_off ? 1 : 0;
1856 				break;
1857 			case 25:		/* Cursor on/off */
1858 				vc->vc_deccm = on_off;
1859 				break;
1860 			case 1000:
1861 				vc->vc_report_mouse = on_off ? 2 : 0;
1862 				break;
1863 			}
1864 		} else {
1865 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1866 			case 3:			/* Monitor (display ctrls) */
1867 				vc->vc_disp_ctrl = on_off;
1868 				break;
1869 			case 4:			/* Insert Mode on/off */
1870 				vc->vc_decim = on_off;
1871 				break;
1872 			case 20:		/* Lf, Enter == CrLf/Lf */
1873 				if (on_off)
1874 					set_kbd(vc, lnm);
1875 				else
1876 					clr_kbd(vc, lnm);
1877 				break;
1878 			}
1879 		}
1880 }
1881 
1882 /* console_lock is held */
1883 static void setterm_command(struct vc_data *vc)
1884 {
1885 	switch(vc->vc_par[0]) {
1886 		case 1:	/* set color for underline mode */
1887 			if (vc->vc_can_do_color &&
1888 					vc->vc_par[1] < 16) {
1889 				vc->vc_ulcolor = color_table[vc->vc_par[1]];
1890 				if (vc->vc_underline)
1891 					update_attr(vc);
1892 			}
1893 			break;
1894 		case 2:	/* set color for half intensity mode */
1895 			if (vc->vc_can_do_color &&
1896 					vc->vc_par[1] < 16) {
1897 				vc->vc_halfcolor = color_table[vc->vc_par[1]];
1898 				if (vc->vc_intensity == 0)
1899 					update_attr(vc);
1900 			}
1901 			break;
1902 		case 8:	/* store colors as defaults */
1903 			vc->vc_def_color = vc->vc_attr;
1904 			if (vc->vc_hi_font_mask == 0x100)
1905 				vc->vc_def_color >>= 1;
1906 			default_attr(vc);
1907 			update_attr(vc);
1908 			break;
1909 		case 9:	/* set blanking interval */
1910 			blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1911 			poke_blanked_console();
1912 			break;
1913 		case 10: /* set bell frequency in Hz */
1914 			if (vc->vc_npar >= 1)
1915 				vc->vc_bell_pitch = vc->vc_par[1];
1916 			else
1917 				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1918 			break;
1919 		case 11: /* set bell duration in msec */
1920 			if (vc->vc_npar >= 1)
1921 				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1922 					msecs_to_jiffies(vc->vc_par[1]) : 0;
1923 			else
1924 				vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1925 			break;
1926 		case 12: /* bring specified console to the front */
1927 			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1928 				set_console(vc->vc_par[1] - 1);
1929 			break;
1930 		case 13: /* unblank the screen */
1931 			poke_blanked_console();
1932 			break;
1933 		case 14: /* set vesa powerdown interval */
1934 			vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1935 			break;
1936 		case 15: /* activate the previous console */
1937 			set_console(last_console);
1938 			break;
1939 		case 16: /* set cursor blink duration in msec */
1940 			if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1941 					vc->vc_par[1] <= USHRT_MAX)
1942 				vc->vc_cur_blink_ms = vc->vc_par[1];
1943 			else
1944 				vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1945 			break;
1946 	}
1947 }
1948 
1949 /* console_lock is held */
1950 static void csi_at(struct vc_data *vc, unsigned int nr)
1951 {
1952 	if (nr > vc->vc_cols - vc->vc_x)
1953 		nr = vc->vc_cols - vc->vc_x;
1954 	else if (!nr)
1955 		nr = 1;
1956 	insert_char(vc, nr);
1957 }
1958 
1959 /* console_lock is held */
1960 static void csi_L(struct vc_data *vc, unsigned int nr)
1961 {
1962 	if (nr > vc->vc_rows - vc->vc_y)
1963 		nr = vc->vc_rows - vc->vc_y;
1964 	else if (!nr)
1965 		nr = 1;
1966 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_DOWN, nr);
1967 	vc->vc_need_wrap = 0;
1968 }
1969 
1970 /* console_lock is held */
1971 static void csi_P(struct vc_data *vc, unsigned int nr)
1972 {
1973 	if (nr > vc->vc_cols - vc->vc_x)
1974 		nr = vc->vc_cols - vc->vc_x;
1975 	else if (!nr)
1976 		nr = 1;
1977 	delete_char(vc, nr);
1978 }
1979 
1980 /* console_lock is held */
1981 static void csi_M(struct vc_data *vc, unsigned int nr)
1982 {
1983 	if (nr > vc->vc_rows - vc->vc_y)
1984 		nr = vc->vc_rows - vc->vc_y;
1985 	else if (!nr)
1986 		nr=1;
1987 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_UP, nr);
1988 	vc->vc_need_wrap = 0;
1989 }
1990 
1991 /* console_lock is held (except via vc_init->reset_terminal */
1992 static void save_cur(struct vc_data *vc)
1993 {
1994 	vc->vc_saved_x		= vc->vc_x;
1995 	vc->vc_saved_y		= vc->vc_y;
1996 	vc->vc_s_intensity	= vc->vc_intensity;
1997 	vc->vc_s_italic         = vc->vc_italic;
1998 	vc->vc_s_underline	= vc->vc_underline;
1999 	vc->vc_s_blink		= vc->vc_blink;
2000 	vc->vc_s_reverse	= vc->vc_reverse;
2001 	vc->vc_s_charset	= vc->vc_charset;
2002 	vc->vc_s_color		= vc->vc_color;
2003 	vc->vc_saved_G0		= vc->vc_G0_charset;
2004 	vc->vc_saved_G1		= vc->vc_G1_charset;
2005 }
2006 
2007 /* console_lock is held */
2008 static void restore_cur(struct vc_data *vc)
2009 {
2010 	gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
2011 	vc->vc_intensity	= vc->vc_s_intensity;
2012 	vc->vc_italic		= vc->vc_s_italic;
2013 	vc->vc_underline	= vc->vc_s_underline;
2014 	vc->vc_blink		= vc->vc_s_blink;
2015 	vc->vc_reverse		= vc->vc_s_reverse;
2016 	vc->vc_charset		= vc->vc_s_charset;
2017 	vc->vc_color		= vc->vc_s_color;
2018 	vc->vc_G0_charset	= vc->vc_saved_G0;
2019 	vc->vc_G1_charset	= vc->vc_saved_G1;
2020 	vc->vc_translate	= set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
2021 	update_attr(vc);
2022 	vc->vc_need_wrap = 0;
2023 }
2024 
2025 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2026 	EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2027 	ESpalette, ESosc };
2028 
2029 /* console_lock is held (except via vc_init()) */
2030 static void reset_terminal(struct vc_data *vc, int do_clear)
2031 {
2032 	vc->vc_top		= 0;
2033 	vc->vc_bottom		= vc->vc_rows;
2034 	vc->vc_state		= ESnormal;
2035 	vc->vc_priv		= EPecma;
2036 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
2037 	vc->vc_G0_charset	= LAT1_MAP;
2038 	vc->vc_G1_charset	= GRAF_MAP;
2039 	vc->vc_charset		= 0;
2040 	vc->vc_need_wrap	= 0;
2041 	vc->vc_report_mouse	= 0;
2042 	vc->vc_utf              = default_utf8;
2043 	vc->vc_utf_count	= 0;
2044 
2045 	vc->vc_disp_ctrl	= 0;
2046 	vc->vc_toggle_meta	= 0;
2047 
2048 	vc->vc_decscnm		= 0;
2049 	vc->vc_decom		= 0;
2050 	vc->vc_decawm		= 1;
2051 	vc->vc_deccm		= global_cursor_default;
2052 	vc->vc_decim		= 0;
2053 
2054 	vt_reset_keyboard(vc->vc_num);
2055 
2056 	vc->vc_cursor_type = cur_default;
2057 	vc->vc_complement_mask = vc->vc_s_complement_mask;
2058 
2059 	default_attr(vc);
2060 	update_attr(vc);
2061 
2062 	vc->vc_tab_stop[0]	=
2063 	vc->vc_tab_stop[1]	=
2064 	vc->vc_tab_stop[2]	=
2065 	vc->vc_tab_stop[3]	=
2066 	vc->vc_tab_stop[4]	=
2067 	vc->vc_tab_stop[5]	=
2068 	vc->vc_tab_stop[6]	=
2069 	vc->vc_tab_stop[7]	= 0x01010101;
2070 
2071 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2072 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2073 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2074 
2075 	gotoxy(vc, 0, 0);
2076 	save_cur(vc);
2077 	if (do_clear)
2078 	    csi_J(vc, 2);
2079 }
2080 
2081 /* console_lock is held */
2082 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2083 {
2084 	/*
2085 	 *  Control characters can be used in the _middle_
2086 	 *  of an escape sequence.
2087 	 */
2088 	if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
2089 		return;
2090 	switch (c) {
2091 	case 0:
2092 		return;
2093 	case 7:
2094 		if (vc->vc_state == ESosc)
2095 			vc->vc_state = ESnormal;
2096 		else if (vc->vc_bell_duration)
2097 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2098 		return;
2099 	case 8:
2100 		bs(vc);
2101 		return;
2102 	case 9:
2103 		vc->vc_pos -= (vc->vc_x << 1);
2104 		while (vc->vc_x < vc->vc_cols - 1) {
2105 			vc->vc_x++;
2106 			if (vc->vc_tab_stop[7 & (vc->vc_x >> 5)] & (1 << (vc->vc_x & 31)))
2107 				break;
2108 		}
2109 		vc->vc_pos += (vc->vc_x << 1);
2110 		notify_write(vc, '\t');
2111 		return;
2112 	case 10: case 11: case 12:
2113 		lf(vc);
2114 		if (!is_kbd(vc, lnm))
2115 			return;
2116 		/* fall through */
2117 	case 13:
2118 		cr(vc);
2119 		return;
2120 	case 14:
2121 		vc->vc_charset = 1;
2122 		vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2123 		vc->vc_disp_ctrl = 1;
2124 		return;
2125 	case 15:
2126 		vc->vc_charset = 0;
2127 		vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2128 		vc->vc_disp_ctrl = 0;
2129 		return;
2130 	case 24: case 26:
2131 		vc->vc_state = ESnormal;
2132 		return;
2133 	case 27:
2134 		vc->vc_state = ESesc;
2135 		return;
2136 	case 127:
2137 		del(vc);
2138 		return;
2139 	case 128+27:
2140 		vc->vc_state = ESsquare;
2141 		return;
2142 	}
2143 	switch(vc->vc_state) {
2144 	case ESesc:
2145 		vc->vc_state = ESnormal;
2146 		switch (c) {
2147 		case '[':
2148 			vc->vc_state = ESsquare;
2149 			return;
2150 		case ']':
2151 			vc->vc_state = ESnonstd;
2152 			return;
2153 		case '%':
2154 			vc->vc_state = ESpercent;
2155 			return;
2156 		case 'E':
2157 			cr(vc);
2158 			lf(vc);
2159 			return;
2160 		case 'M':
2161 			ri(vc);
2162 			return;
2163 		case 'D':
2164 			lf(vc);
2165 			return;
2166 		case 'H':
2167 			vc->vc_tab_stop[7 & (vc->vc_x >> 5)] |= (1 << (vc->vc_x & 31));
2168 			return;
2169 		case 'Z':
2170 			respond_ID(tty);
2171 			return;
2172 		case '7':
2173 			save_cur(vc);
2174 			return;
2175 		case '8':
2176 			restore_cur(vc);
2177 			return;
2178 		case '(':
2179 			vc->vc_state = ESsetG0;
2180 			return;
2181 		case ')':
2182 			vc->vc_state = ESsetG1;
2183 			return;
2184 		case '#':
2185 			vc->vc_state = EShash;
2186 			return;
2187 		case 'c':
2188 			reset_terminal(vc, 1);
2189 			return;
2190 		case '>':  /* Numeric keypad */
2191 			clr_kbd(vc, kbdapplic);
2192 			return;
2193 		case '=':  /* Appl. keypad */
2194 			set_kbd(vc, kbdapplic);
2195 			return;
2196 		}
2197 		return;
2198 	case ESnonstd:
2199 		if (c=='P') {   /* palette escape sequence */
2200 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2201 				vc->vc_par[vc->vc_npar] = 0;
2202 			vc->vc_npar = 0;
2203 			vc->vc_state = ESpalette;
2204 			return;
2205 		} else if (c=='R') {   /* reset palette */
2206 			reset_palette(vc);
2207 			vc->vc_state = ESnormal;
2208 		} else if (c>='0' && c<='9')
2209 			vc->vc_state = ESosc;
2210 		else
2211 			vc->vc_state = ESnormal;
2212 		return;
2213 	case ESpalette:
2214 		if (isxdigit(c)) {
2215 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2216 			if (vc->vc_npar == 7) {
2217 				int i = vc->vc_par[0] * 3, j = 1;
2218 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2219 				vc->vc_palette[i++] += vc->vc_par[j++];
2220 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2221 				vc->vc_palette[i++] += vc->vc_par[j++];
2222 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
2223 				vc->vc_palette[i] += vc->vc_par[j];
2224 				set_palette(vc);
2225 				vc->vc_state = ESnormal;
2226 			}
2227 		} else
2228 			vc->vc_state = ESnormal;
2229 		return;
2230 	case ESsquare:
2231 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2232 			vc->vc_par[vc->vc_npar] = 0;
2233 		vc->vc_npar = 0;
2234 		vc->vc_state = ESgetpars;
2235 		if (c == '[') { /* Function key */
2236 			vc->vc_state=ESfunckey;
2237 			return;
2238 		}
2239 		switch (c) {
2240 		case '?':
2241 			vc->vc_priv = EPdec;
2242 			return;
2243 		case '>':
2244 			vc->vc_priv = EPgt;
2245 			return;
2246 		case '=':
2247 			vc->vc_priv = EPeq;
2248 			return;
2249 		case '<':
2250 			vc->vc_priv = EPlt;
2251 			return;
2252 		}
2253 		vc->vc_priv = EPecma;
2254 		/* fall through */
2255 	case ESgetpars:
2256 		if (c == ';' && vc->vc_npar < NPAR - 1) {
2257 			vc->vc_npar++;
2258 			return;
2259 		} else if (c>='0' && c<='9') {
2260 			vc->vc_par[vc->vc_npar] *= 10;
2261 			vc->vc_par[vc->vc_npar] += c - '0';
2262 			return;
2263 		}
2264 		if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2265 			vc->vc_state = EScsiignore;
2266 			return;
2267 		}
2268 		vc->vc_state = ESnormal;
2269 		switch(c) {
2270 		case 'h':
2271 			if (vc->vc_priv <= EPdec)
2272 				set_mode(vc, 1);
2273 			return;
2274 		case 'l':
2275 			if (vc->vc_priv <= EPdec)
2276 				set_mode(vc, 0);
2277 			return;
2278 		case 'c':
2279 			if (vc->vc_priv == EPdec) {
2280 				if (vc->vc_par[0])
2281 					vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
2282 				else
2283 					vc->vc_cursor_type = cur_default;
2284 				return;
2285 			}
2286 			break;
2287 		case 'm':
2288 			if (vc->vc_priv == EPdec) {
2289 				clear_selection();
2290 				if (vc->vc_par[0])
2291 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2292 				else
2293 					vc->vc_complement_mask = vc->vc_s_complement_mask;
2294 				return;
2295 			}
2296 			break;
2297 		case 'n':
2298 			if (vc->vc_priv == EPecma) {
2299 				if (vc->vc_par[0] == 5)
2300 					status_report(tty);
2301 				else if (vc->vc_par[0] == 6)
2302 					cursor_report(vc, tty);
2303 			}
2304 			return;
2305 		}
2306 		if (vc->vc_priv != EPecma) {
2307 			vc->vc_priv = EPecma;
2308 			return;
2309 		}
2310 		switch(c) {
2311 		case 'G': case '`':
2312 			if (vc->vc_par[0])
2313 				vc->vc_par[0]--;
2314 			gotoxy(vc, vc->vc_par[0], vc->vc_y);
2315 			return;
2316 		case 'A':
2317 			if (!vc->vc_par[0])
2318 				vc->vc_par[0]++;
2319 			gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
2320 			return;
2321 		case 'B': case 'e':
2322 			if (!vc->vc_par[0])
2323 				vc->vc_par[0]++;
2324 			gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
2325 			return;
2326 		case 'C': case 'a':
2327 			if (!vc->vc_par[0])
2328 				vc->vc_par[0]++;
2329 			gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
2330 			return;
2331 		case 'D':
2332 			if (!vc->vc_par[0])
2333 				vc->vc_par[0]++;
2334 			gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
2335 			return;
2336 		case 'E':
2337 			if (!vc->vc_par[0])
2338 				vc->vc_par[0]++;
2339 			gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
2340 			return;
2341 		case 'F':
2342 			if (!vc->vc_par[0])
2343 				vc->vc_par[0]++;
2344 			gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
2345 			return;
2346 		case 'd':
2347 			if (vc->vc_par[0])
2348 				vc->vc_par[0]--;
2349 			gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
2350 			return;
2351 		case 'H': case 'f':
2352 			if (vc->vc_par[0])
2353 				vc->vc_par[0]--;
2354 			if (vc->vc_par[1])
2355 				vc->vc_par[1]--;
2356 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2357 			return;
2358 		case 'J':
2359 			csi_J(vc, vc->vc_par[0]);
2360 			return;
2361 		case 'K':
2362 			csi_K(vc, vc->vc_par[0]);
2363 			return;
2364 		case 'L':
2365 			csi_L(vc, vc->vc_par[0]);
2366 			return;
2367 		case 'M':
2368 			csi_M(vc, vc->vc_par[0]);
2369 			return;
2370 		case 'P':
2371 			csi_P(vc, vc->vc_par[0]);
2372 			return;
2373 		case 'c':
2374 			if (!vc->vc_par[0])
2375 				respond_ID(tty);
2376 			return;
2377 		case 'g':
2378 			if (!vc->vc_par[0])
2379 				vc->vc_tab_stop[7 & (vc->vc_x >> 5)] &= ~(1 << (vc->vc_x & 31));
2380 			else if (vc->vc_par[0] == 3) {
2381 				vc->vc_tab_stop[0] =
2382 					vc->vc_tab_stop[1] =
2383 					vc->vc_tab_stop[2] =
2384 					vc->vc_tab_stop[3] =
2385 					vc->vc_tab_stop[4] =
2386 					vc->vc_tab_stop[5] =
2387 					vc->vc_tab_stop[6] =
2388 					vc->vc_tab_stop[7] = 0;
2389 			}
2390 			return;
2391 		case 'm':
2392 			csi_m(vc);
2393 			return;
2394 		case 'q': /* DECLL - but only 3 leds */
2395 			/* map 0,1,2,3 to 0,1,2,4 */
2396 			if (vc->vc_par[0] < 4)
2397 				vt_set_led_state(vc->vc_num,
2398 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2399 			return;
2400 		case 'r':
2401 			if (!vc->vc_par[0])
2402 				vc->vc_par[0]++;
2403 			if (!vc->vc_par[1])
2404 				vc->vc_par[1] = vc->vc_rows;
2405 			/* Minimum allowed region is 2 lines */
2406 			if (vc->vc_par[0] < vc->vc_par[1] &&
2407 			    vc->vc_par[1] <= vc->vc_rows) {
2408 				vc->vc_top = vc->vc_par[0] - 1;
2409 				vc->vc_bottom = vc->vc_par[1];
2410 				gotoxay(vc, 0, 0);
2411 			}
2412 			return;
2413 		case 's':
2414 			save_cur(vc);
2415 			return;
2416 		case 'u':
2417 			restore_cur(vc);
2418 			return;
2419 		case 'X':
2420 			csi_X(vc, vc->vc_par[0]);
2421 			return;
2422 		case '@':
2423 			csi_at(vc, vc->vc_par[0]);
2424 			return;
2425 		case ']': /* setterm functions */
2426 			setterm_command(vc);
2427 			return;
2428 		}
2429 		return;
2430 	case EScsiignore:
2431 		if (c >= 20 && c <= 0x3f)
2432 			return;
2433 		vc->vc_state = ESnormal;
2434 		return;
2435 	case ESpercent:
2436 		vc->vc_state = ESnormal;
2437 		switch (c) {
2438 		case '@':  /* defined in ISO 2022 */
2439 			vc->vc_utf = 0;
2440 			return;
2441 		case 'G':  /* prelim official escape code */
2442 		case '8':  /* retained for compatibility */
2443 			vc->vc_utf = 1;
2444 			return;
2445 		}
2446 		return;
2447 	case ESfunckey:
2448 		vc->vc_state = ESnormal;
2449 		return;
2450 	case EShash:
2451 		vc->vc_state = ESnormal;
2452 		if (c == '8') {
2453 			/* DEC screen alignment test. kludge :-) */
2454 			vc->vc_video_erase_char =
2455 				(vc->vc_video_erase_char & 0xff00) | 'E';
2456 			csi_J(vc, 2);
2457 			vc->vc_video_erase_char =
2458 				(vc->vc_video_erase_char & 0xff00) | ' ';
2459 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2460 		}
2461 		return;
2462 	case ESsetG0:
2463 		if (c == '0')
2464 			vc->vc_G0_charset = GRAF_MAP;
2465 		else if (c == 'B')
2466 			vc->vc_G0_charset = LAT1_MAP;
2467 		else if (c == 'U')
2468 			vc->vc_G0_charset = IBMPC_MAP;
2469 		else if (c == 'K')
2470 			vc->vc_G0_charset = USER_MAP;
2471 		if (vc->vc_charset == 0)
2472 			vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2473 		vc->vc_state = ESnormal;
2474 		return;
2475 	case ESsetG1:
2476 		if (c == '0')
2477 			vc->vc_G1_charset = GRAF_MAP;
2478 		else if (c == 'B')
2479 			vc->vc_G1_charset = LAT1_MAP;
2480 		else if (c == 'U')
2481 			vc->vc_G1_charset = IBMPC_MAP;
2482 		else if (c == 'K')
2483 			vc->vc_G1_charset = USER_MAP;
2484 		if (vc->vc_charset == 1)
2485 			vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2486 		vc->vc_state = ESnormal;
2487 		return;
2488 	case ESosc:
2489 		return;
2490 	default:
2491 		vc->vc_state = ESnormal;
2492 	}
2493 }
2494 
2495 /* is_double_width() is based on the wcwidth() implementation by
2496  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2497  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2498  */
2499 struct interval {
2500 	uint32_t first;
2501 	uint32_t last;
2502 };
2503 
2504 static int ucs_cmp(const void *key, const void *elt)
2505 {
2506 	uint32_t ucs = *(uint32_t *)key;
2507 	struct interval e = *(struct interval *) elt;
2508 
2509 	if (ucs > e.last)
2510 		return 1;
2511 	else if (ucs < e.first)
2512 		return -1;
2513 	return 0;
2514 }
2515 
2516 static int is_double_width(uint32_t ucs)
2517 {
2518 	static const struct interval double_width[] = {
2519 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2520 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2521 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2522 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2523 	};
2524 	if (ucs < double_width[0].first ||
2525 	    ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2526 		return 0;
2527 
2528 	return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2529 			sizeof(struct interval), ucs_cmp) != NULL;
2530 }
2531 
2532 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2533 		unsigned long draw_to, int *draw_x)
2534 {
2535 	if (*draw_x < 0)
2536 		return;
2537 
2538 	vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2539 			(u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2540 	*draw_x = -1;
2541 }
2542 
2543 /* acquires console_lock */
2544 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2545 {
2546 	int c, next_c, tc, ok, n = 0, draw_x = -1;
2547 	unsigned int currcons;
2548 	unsigned long draw_from = 0, draw_to = 0;
2549 	struct vc_data *vc;
2550 	unsigned char vc_attr;
2551 	struct vt_notifier_param param;
2552 	uint8_t rescan;
2553 	uint8_t inverse;
2554 	uint8_t width;
2555 	u16 himask, charmask;
2556 
2557 	if (in_interrupt())
2558 		return count;
2559 
2560 	might_sleep();
2561 
2562 	console_lock();
2563 	vc = tty->driver_data;
2564 	if (vc == NULL) {
2565 		pr_err("vt: argh, driver_data is NULL !\n");
2566 		console_unlock();
2567 		return 0;
2568 	}
2569 
2570 	currcons = vc->vc_num;
2571 	if (!vc_cons_allocated(currcons)) {
2572 		/* could this happen? */
2573 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2574 		console_unlock();
2575 		return 0;
2576 	}
2577 
2578 	himask = vc->vc_hi_font_mask;
2579 	charmask = himask ? 0x1ff : 0xff;
2580 
2581 	/* undraw cursor first */
2582 	if (con_is_fg(vc))
2583 		hide_cursor(vc);
2584 
2585 	param.vc = vc;
2586 
2587 	while (!tty->stopped && count) {
2588 		int orig = *buf;
2589 		c = orig;
2590 		buf++;
2591 		n++;
2592 		count--;
2593 		rescan = 0;
2594 		inverse = 0;
2595 		width = 1;
2596 
2597 		/* Do no translation at all in control states */
2598 		if (vc->vc_state != ESnormal) {
2599 			tc = c;
2600 		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2601 		    /* Combine UTF-8 into Unicode in vc_utf_char.
2602 		     * vc_utf_count is the number of continuation bytes still
2603 		     * expected to arrive.
2604 		     * vc_npar is the number of continuation bytes arrived so
2605 		     * far
2606 		     */
2607 rescan_last_byte:
2608 		    if ((c & 0xc0) == 0x80) {
2609 			/* Continuation byte received */
2610 			static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2611 			if (vc->vc_utf_count) {
2612 			    vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2613 			    vc->vc_npar++;
2614 			    if (--vc->vc_utf_count) {
2615 				/* Still need some bytes */
2616 				continue;
2617 			    }
2618 			    /* Got a whole character */
2619 			    c = vc->vc_utf_char;
2620 			    /* Reject overlong sequences */
2621 			    if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2622 					c > utf8_length_changes[vc->vc_npar])
2623 				c = 0xfffd;
2624 			} else {
2625 			    /* Unexpected continuation byte */
2626 			    vc->vc_utf_count = 0;
2627 			    c = 0xfffd;
2628 			}
2629 		    } else {
2630 			/* Single ASCII byte or first byte of a sequence received */
2631 			if (vc->vc_utf_count) {
2632 			    /* Continuation byte expected */
2633 			    rescan = 1;
2634 			    vc->vc_utf_count = 0;
2635 			    c = 0xfffd;
2636 			} else if (c > 0x7f) {
2637 			    /* First byte of a multibyte sequence received */
2638 			    vc->vc_npar = 0;
2639 			    if ((c & 0xe0) == 0xc0) {
2640 				vc->vc_utf_count = 1;
2641 				vc->vc_utf_char = (c & 0x1f);
2642 			    } else if ((c & 0xf0) == 0xe0) {
2643 				vc->vc_utf_count = 2;
2644 				vc->vc_utf_char = (c & 0x0f);
2645 			    } else if ((c & 0xf8) == 0xf0) {
2646 				vc->vc_utf_count = 3;
2647 				vc->vc_utf_char = (c & 0x07);
2648 			    } else if ((c & 0xfc) == 0xf8) {
2649 				vc->vc_utf_count = 4;
2650 				vc->vc_utf_char = (c & 0x03);
2651 			    } else if ((c & 0xfe) == 0xfc) {
2652 				vc->vc_utf_count = 5;
2653 				vc->vc_utf_char = (c & 0x01);
2654 			    } else {
2655 				/* 254 and 255 are invalid */
2656 				c = 0xfffd;
2657 			    }
2658 			    if (vc->vc_utf_count) {
2659 				/* Still need some bytes */
2660 				continue;
2661 			    }
2662 			}
2663 			/* Nothing to do if an ASCII byte was received */
2664 		    }
2665 		    /* End of UTF-8 decoding. */
2666 		    /* c is the received character, or U+FFFD for invalid sequences. */
2667 		    /* Replace invalid Unicode code points with U+FFFD too */
2668 		    if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2669 			c = 0xfffd;
2670 		    tc = c;
2671 		} else {	/* no utf or alternate charset mode */
2672 		    tc = vc_translate(vc, c);
2673 		}
2674 
2675 		param.c = tc;
2676 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2677 					&param) == NOTIFY_STOP)
2678 			continue;
2679 
2680                 /* If the original code was a control character we
2681                  * only allow a glyph to be displayed if the code is
2682                  * not normally used (such as for cursor movement) or
2683                  * if the disp_ctrl mode has been explicitly enabled.
2684                  * Certain characters (as given by the CTRL_ALWAYS
2685                  * bitmap) are always displayed as control characters,
2686                  * as the console would be pretty useless without
2687                  * them; to display an arbitrary font position use the
2688                  * direct-to-font zone in UTF-8 mode.
2689                  */
2690                 ok = tc && (c >= 32 ||
2691 			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2692 				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2693 			&& (c != 127 || vc->vc_disp_ctrl)
2694 			&& (c != 128+27);
2695 
2696 		if (vc->vc_state == ESnormal && ok) {
2697 			if (vc->vc_utf && !vc->vc_disp_ctrl) {
2698 				if (is_double_width(c))
2699 					width = 2;
2700 			}
2701 			/* Now try to find out how to display it */
2702 			tc = conv_uni_to_pc(vc, tc);
2703 			if (tc & ~charmask) {
2704 				if (tc == -1 || tc == -2) {
2705 				    continue; /* nothing to display */
2706 				}
2707 				/* Glyph not found */
2708 				if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2709 				    /* In legacy mode use the glyph we get by a 1:1 mapping.
2710 				       This would make absolutely no sense with Unicode in mind,
2711 				       but do this for ASCII characters since a font may lack
2712 				       Unicode mapping info and we don't want to end up with
2713 				       having question marks only. */
2714 				    tc = c;
2715 				} else {
2716 				    /* Display U+FFFD. If it's not found, display an inverse question mark. */
2717 				    tc = conv_uni_to_pc(vc, 0xfffd);
2718 				    if (tc < 0) {
2719 					inverse = 1;
2720 					tc = conv_uni_to_pc(vc, '?');
2721 					if (tc < 0) tc = '?';
2722 				    }
2723 				}
2724 			}
2725 
2726 			if (!inverse) {
2727 				vc_attr = vc->vc_attr;
2728 			} else {
2729 				/* invert vc_attr */
2730 				if (!vc->vc_can_do_color) {
2731 					vc_attr = (vc->vc_attr) ^ 0x08;
2732 				} else if (vc->vc_hi_font_mask == 0x100) {
2733 					vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2734 				} else {
2735 					vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2736 				}
2737 				con_flush(vc, draw_from, draw_to, &draw_x);
2738 			}
2739 
2740 			next_c = c;
2741 			while (1) {
2742 				if (vc->vc_need_wrap || vc->vc_decim)
2743 					con_flush(vc, draw_from, draw_to,
2744 							&draw_x);
2745 				if (vc->vc_need_wrap) {
2746 					cr(vc);
2747 					lf(vc);
2748 				}
2749 				if (vc->vc_decim)
2750 					insert_char(vc, 1);
2751 				vc_uniscr_putc(vc, next_c);
2752 				scr_writew(himask ?
2753 					     ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2754 					     (vc_attr << 8) + tc,
2755 					   (u16 *) vc->vc_pos);
2756 				if (con_should_update(vc) && draw_x < 0) {
2757 					draw_x = vc->vc_x;
2758 					draw_from = vc->vc_pos;
2759 				}
2760 				if (vc->vc_x == vc->vc_cols - 1) {
2761 					vc->vc_need_wrap = vc->vc_decawm;
2762 					draw_to = vc->vc_pos + 2;
2763 				} else {
2764 					vc->vc_x++;
2765 					draw_to = (vc->vc_pos += 2);
2766 				}
2767 
2768 				if (!--width) break;
2769 
2770 				tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2771 				if (tc < 0) tc = ' ';
2772 				next_c = ' ';
2773 			}
2774 			notify_write(vc, c);
2775 
2776 			if (inverse)
2777 				con_flush(vc, draw_from, draw_to, &draw_x);
2778 
2779 			if (rescan) {
2780 				rescan = 0;
2781 				inverse = 0;
2782 				width = 1;
2783 				c = orig;
2784 				goto rescan_last_byte;
2785 			}
2786 			continue;
2787 		}
2788 		con_flush(vc, draw_from, draw_to, &draw_x);
2789 		do_con_trol(tty, vc, orig);
2790 	}
2791 	con_flush(vc, draw_from, draw_to, &draw_x);
2792 	vc_uniscr_debug_check(vc);
2793 	console_conditional_schedule();
2794 	notify_update(vc);
2795 	console_unlock();
2796 	return n;
2797 }
2798 
2799 /*
2800  * This is the console switching callback.
2801  *
2802  * Doing console switching in a process context allows
2803  * us to do the switches asynchronously (needed when we want
2804  * to switch due to a keyboard interrupt).  Synchronization
2805  * with other console code and prevention of re-entrancy is
2806  * ensured with console_lock.
2807  */
2808 static void console_callback(struct work_struct *ignored)
2809 {
2810 	console_lock();
2811 
2812 	if (want_console >= 0) {
2813 		if (want_console != fg_console &&
2814 		    vc_cons_allocated(want_console)) {
2815 			hide_cursor(vc_cons[fg_console].d);
2816 			change_console(vc_cons[want_console].d);
2817 			/* we only changed when the console had already
2818 			   been allocated - a new console is not created
2819 			   in an interrupt routine */
2820 		}
2821 		want_console = -1;
2822 	}
2823 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2824 		do_poke_blanked_console = 0;
2825 		poke_blanked_console();
2826 	}
2827 	if (scrollback_delta) {
2828 		struct vc_data *vc = vc_cons[fg_console].d;
2829 		clear_selection();
2830 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2831 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2832 		scrollback_delta = 0;
2833 	}
2834 	if (blank_timer_expired) {
2835 		do_blank_screen(0);
2836 		blank_timer_expired = 0;
2837 	}
2838 	notify_update(vc_cons[fg_console].d);
2839 
2840 	console_unlock();
2841 }
2842 
2843 int set_console(int nr)
2844 {
2845 	struct vc_data *vc = vc_cons[fg_console].d;
2846 
2847 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
2848 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2849 
2850 		/*
2851 		 * Console switch will fail in console_callback() or
2852 		 * change_console() so there is no point scheduling
2853 		 * the callback
2854 		 *
2855 		 * Existing set_console() users don't check the return
2856 		 * value so this shouldn't break anything
2857 		 */
2858 		return -EINVAL;
2859 	}
2860 
2861 	want_console = nr;
2862 	schedule_console_callback();
2863 
2864 	return 0;
2865 }
2866 
2867 struct tty_driver *console_driver;
2868 
2869 #ifdef CONFIG_VT_CONSOLE
2870 
2871 /**
2872  * vt_kmsg_redirect() - Sets/gets the kernel message console
2873  * @new:	The new virtual terminal number or -1 if the console should stay
2874  * 		unchanged
2875  *
2876  * By default, the kernel messages are always printed on the current virtual
2877  * console. However, the user may modify that default with the
2878  * TIOCL_SETKMSGREDIRECT ioctl call.
2879  *
2880  * This function sets the kernel message console to be @new. It returns the old
2881  * virtual console number. The virtual terminal number 0 (both as parameter and
2882  * return value) means no redirection (i.e. always printed on the currently
2883  * active console).
2884  *
2885  * The parameter -1 means that only the current console is returned, but the
2886  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2887  * case to make the code more understandable.
2888  *
2889  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2890  * the parameter and always returns 0.
2891  */
2892 int vt_kmsg_redirect(int new)
2893 {
2894 	static int kmsg_con;
2895 
2896 	if (new != -1)
2897 		return xchg(&kmsg_con, new);
2898 	else
2899 		return kmsg_con;
2900 }
2901 
2902 /*
2903  *	Console on virtual terminal
2904  *
2905  * The console must be locked when we get here.
2906  */
2907 
2908 static void vt_console_print(struct console *co, const char *b, unsigned count)
2909 {
2910 	struct vc_data *vc = vc_cons[fg_console].d;
2911 	unsigned char c;
2912 	static DEFINE_SPINLOCK(printing_lock);
2913 	const ushort *start;
2914 	ushort start_x, cnt;
2915 	int kmsg_console;
2916 
2917 	/* console busy or not yet initialized */
2918 	if (!printable)
2919 		return;
2920 	if (!spin_trylock(&printing_lock))
2921 		return;
2922 
2923 	kmsg_console = vt_get_kmsg_redirect();
2924 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2925 		vc = vc_cons[kmsg_console - 1].d;
2926 
2927 	if (!vc_cons_allocated(fg_console)) {
2928 		/* impossible */
2929 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2930 		goto quit;
2931 	}
2932 
2933 	if (vc->vc_mode != KD_TEXT)
2934 		goto quit;
2935 
2936 	/* undraw cursor first */
2937 	if (con_is_fg(vc))
2938 		hide_cursor(vc);
2939 
2940 	start = (ushort *)vc->vc_pos;
2941 	start_x = vc->vc_x;
2942 	cnt = 0;
2943 	while (count--) {
2944 		c = *b++;
2945 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2946 			if (cnt && con_is_visible(vc))
2947 				vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x);
2948 			cnt = 0;
2949 			if (c == 8) {		/* backspace */
2950 				bs(vc);
2951 				start = (ushort *)vc->vc_pos;
2952 				start_x = vc->vc_x;
2953 				continue;
2954 			}
2955 			if (c != 13)
2956 				lf(vc);
2957 			cr(vc);
2958 			start = (ushort *)vc->vc_pos;
2959 			start_x = vc->vc_x;
2960 			if (c == 10 || c == 13)
2961 				continue;
2962 		}
2963 		vc_uniscr_putc(vc, c);
2964 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2965 		notify_write(vc, c);
2966 		cnt++;
2967 		if (vc->vc_x == vc->vc_cols - 1) {
2968 			vc->vc_need_wrap = 1;
2969 		} else {
2970 			vc->vc_pos += 2;
2971 			vc->vc_x++;
2972 		}
2973 	}
2974 	if (cnt && con_is_visible(vc))
2975 		vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x);
2976 	set_cursor(vc);
2977 	notify_update(vc);
2978 
2979 quit:
2980 	spin_unlock(&printing_lock);
2981 }
2982 
2983 static struct tty_driver *vt_console_device(struct console *c, int *index)
2984 {
2985 	*index = c->index ? c->index-1 : fg_console;
2986 	return console_driver;
2987 }
2988 
2989 static struct console vt_console_driver = {
2990 	.name		= "tty",
2991 	.write		= vt_console_print,
2992 	.device		= vt_console_device,
2993 	.unblank	= unblank_screen,
2994 	.flags		= CON_PRINTBUFFER,
2995 	.index		= -1,
2996 };
2997 #endif
2998 
2999 /*
3000  *	Handling of Linux-specific VC ioctls
3001  */
3002 
3003 /*
3004  * Generally a bit racy with respect to console_lock();.
3005  *
3006  * There are some functions which don't need it.
3007  *
3008  * There are some functions which can sleep for arbitrary periods
3009  * (paste_selection) but we don't need the lock there anyway.
3010  *
3011  * set_selection has locking, and definitely needs it
3012  */
3013 
3014 int tioclinux(struct tty_struct *tty, unsigned long arg)
3015 {
3016 	char type, data;
3017 	char __user *p = (char __user *)arg;
3018 	int lines;
3019 	int ret;
3020 
3021 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3022 		return -EPERM;
3023 	if (get_user(type, p))
3024 		return -EFAULT;
3025 	ret = 0;
3026 
3027 	switch (type)
3028 	{
3029 		case TIOCL_SETSEL:
3030 			console_lock();
3031 			ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
3032 			console_unlock();
3033 			break;
3034 		case TIOCL_PASTESEL:
3035 			ret = paste_selection(tty);
3036 			break;
3037 		case TIOCL_UNBLANKSCREEN:
3038 			console_lock();
3039 			unblank_screen();
3040 			console_unlock();
3041 			break;
3042 		case TIOCL_SELLOADLUT:
3043 			console_lock();
3044 			ret = sel_loadlut(p);
3045 			console_unlock();
3046 			break;
3047 		case TIOCL_GETSHIFTSTATE:
3048 
3049 	/*
3050 	 * Make it possible to react to Shift+Mousebutton.
3051 	 * Note that 'shift_state' is an undocumented
3052 	 * kernel-internal variable; programs not closely
3053 	 * related to the kernel should not use this.
3054 	 */
3055 			data = vt_get_shift_state();
3056 			ret = put_user(data, p);
3057 			break;
3058 		case TIOCL_GETMOUSEREPORTING:
3059 			console_lock();	/* May be overkill */
3060 			data = mouse_reporting();
3061 			console_unlock();
3062 			ret = put_user(data, p);
3063 			break;
3064 		case TIOCL_SETVESABLANK:
3065 			console_lock();
3066 			ret = set_vesa_blanking(p);
3067 			console_unlock();
3068 			break;
3069 		case TIOCL_GETKMSGREDIRECT:
3070 			data = vt_get_kmsg_redirect();
3071 			ret = put_user(data, p);
3072 			break;
3073 		case TIOCL_SETKMSGREDIRECT:
3074 			if (!capable(CAP_SYS_ADMIN)) {
3075 				ret = -EPERM;
3076 			} else {
3077 				if (get_user(data, p+1))
3078 					ret = -EFAULT;
3079 				else
3080 					vt_kmsg_redirect(data);
3081 			}
3082 			break;
3083 		case TIOCL_GETFGCONSOLE:
3084 			/* No locking needed as this is a transiently
3085 			   correct return anyway if the caller hasn't
3086 			   disabled switching */
3087 			ret = fg_console;
3088 			break;
3089 		case TIOCL_SCROLLCONSOLE:
3090 			if (get_user(lines, (s32 __user *)(p+4))) {
3091 				ret = -EFAULT;
3092 			} else {
3093 				/* Need the console lock here. Note that lots
3094 				   of other calls need fixing before the lock
3095 				   is actually useful ! */
3096 				console_lock();
3097 				scrollfront(vc_cons[fg_console].d, lines);
3098 				console_unlock();
3099 				ret = 0;
3100 			}
3101 			break;
3102 		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
3103 			console_lock();
3104 			ignore_poke = 1;
3105 			do_blank_screen(0);
3106 			console_unlock();
3107 			break;
3108 		case TIOCL_BLANKEDSCREEN:
3109 			ret = console_blanked;
3110 			break;
3111 		default:
3112 			ret = -EINVAL;
3113 			break;
3114 	}
3115 	return ret;
3116 }
3117 
3118 /*
3119  * /dev/ttyN handling
3120  */
3121 
3122 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3123 {
3124 	int	retval;
3125 
3126 	retval = do_con_write(tty, buf, count);
3127 	con_flush_chars(tty);
3128 
3129 	return retval;
3130 }
3131 
3132 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3133 {
3134 	if (in_interrupt())
3135 		return 0;	/* n_r3964 calls put_char() from interrupt context */
3136 	return do_con_write(tty, &ch, 1);
3137 }
3138 
3139 static int con_write_room(struct tty_struct *tty)
3140 {
3141 	if (tty->stopped)
3142 		return 0;
3143 	return 32768;		/* No limit, really; we're not buffering */
3144 }
3145 
3146 static int con_chars_in_buffer(struct tty_struct *tty)
3147 {
3148 	return 0;		/* we're not buffering */
3149 }
3150 
3151 /*
3152  * con_throttle and con_unthrottle are only used for
3153  * paste_selection(), which has to stuff in a large number of
3154  * characters...
3155  */
3156 static void con_throttle(struct tty_struct *tty)
3157 {
3158 }
3159 
3160 static void con_unthrottle(struct tty_struct *tty)
3161 {
3162 	struct vc_data *vc = tty->driver_data;
3163 
3164 	wake_up_interruptible(&vc->paste_wait);
3165 }
3166 
3167 /*
3168  * Turn the Scroll-Lock LED on when the tty is stopped
3169  */
3170 static void con_stop(struct tty_struct *tty)
3171 {
3172 	int console_num;
3173 	if (!tty)
3174 		return;
3175 	console_num = tty->index;
3176 	if (!vc_cons_allocated(console_num))
3177 		return;
3178 	vt_kbd_con_stop(console_num);
3179 }
3180 
3181 /*
3182  * Turn the Scroll-Lock LED off when the console is started
3183  */
3184 static void con_start(struct tty_struct *tty)
3185 {
3186 	int console_num;
3187 	if (!tty)
3188 		return;
3189 	console_num = tty->index;
3190 	if (!vc_cons_allocated(console_num))
3191 		return;
3192 	vt_kbd_con_start(console_num);
3193 }
3194 
3195 static void con_flush_chars(struct tty_struct *tty)
3196 {
3197 	struct vc_data *vc;
3198 
3199 	if (in_interrupt())	/* from flush_to_ldisc */
3200 		return;
3201 
3202 	/* if we race with con_close(), vt may be null */
3203 	console_lock();
3204 	vc = tty->driver_data;
3205 	if (vc)
3206 		set_cursor(vc);
3207 	console_unlock();
3208 }
3209 
3210 /*
3211  * Allocate the console screen memory.
3212  */
3213 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3214 {
3215 	unsigned int currcons = tty->index;
3216 	struct vc_data *vc;
3217 	int ret;
3218 
3219 	console_lock();
3220 	ret = vc_allocate(currcons);
3221 	if (ret)
3222 		goto unlock;
3223 
3224 	vc = vc_cons[currcons].d;
3225 
3226 	/* Still being freed */
3227 	if (vc->port.tty) {
3228 		ret = -ERESTARTSYS;
3229 		goto unlock;
3230 	}
3231 
3232 	ret = tty_port_install(&vc->port, driver, tty);
3233 	if (ret)
3234 		goto unlock;
3235 
3236 	tty->driver_data = vc;
3237 	vc->port.tty = tty;
3238 
3239 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3240 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3241 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3242 	}
3243 	if (vc->vc_utf)
3244 		tty->termios.c_iflag |= IUTF8;
3245 	else
3246 		tty->termios.c_iflag &= ~IUTF8;
3247 unlock:
3248 	console_unlock();
3249 	return ret;
3250 }
3251 
3252 static int con_open(struct tty_struct *tty, struct file *filp)
3253 {
3254 	/* everything done in install */
3255 	return 0;
3256 }
3257 
3258 
3259 static void con_close(struct tty_struct *tty, struct file *filp)
3260 {
3261 	/* Nothing to do - we defer to shutdown */
3262 }
3263 
3264 static void con_shutdown(struct tty_struct *tty)
3265 {
3266 	struct vc_data *vc = tty->driver_data;
3267 	BUG_ON(vc == NULL);
3268 	console_lock();
3269 	vc->port.tty = NULL;
3270 	console_unlock();
3271 }
3272 
3273 static int default_color           = 7; /* white */
3274 static int default_italic_color    = 2; // green (ASCII)
3275 static int default_underline_color = 3; // cyan (ASCII)
3276 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3277 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3278 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3279 
3280 static void vc_init(struct vc_data *vc, unsigned int rows,
3281 		    unsigned int cols, int do_clear)
3282 {
3283 	int j, k ;
3284 
3285 	vc->vc_cols = cols;
3286 	vc->vc_rows = rows;
3287 	vc->vc_size_row = cols << 1;
3288 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3289 
3290 	set_origin(vc);
3291 	vc->vc_pos = vc->vc_origin;
3292 	reset_vc(vc);
3293 	for (j=k=0; j<16; j++) {
3294 		vc->vc_palette[k++] = default_red[j] ;
3295 		vc->vc_palette[k++] = default_grn[j] ;
3296 		vc->vc_palette[k++] = default_blu[j] ;
3297 	}
3298 	vc->vc_def_color       = default_color;
3299 	vc->vc_ulcolor         = default_underline_color;
3300 	vc->vc_itcolor         = default_italic_color;
3301 	vc->vc_halfcolor       = 0x08;   /* grey */
3302 	init_waitqueue_head(&vc->paste_wait);
3303 	reset_terminal(vc, do_clear);
3304 }
3305 
3306 /*
3307  * This routine initializes console interrupts, and does nothing
3308  * else. If you want the screen to clear, call tty_write with
3309  * the appropriate escape-sequence.
3310  */
3311 
3312 static int __init con_init(void)
3313 {
3314 	const char *display_desc = NULL;
3315 	struct vc_data *vc;
3316 	unsigned int currcons = 0, i;
3317 
3318 	console_lock();
3319 
3320 	if (conswitchp)
3321 		display_desc = conswitchp->con_startup();
3322 	if (!display_desc) {
3323 		fg_console = 0;
3324 		console_unlock();
3325 		return 0;
3326 	}
3327 
3328 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3329 		struct con_driver *con_driver = &registered_con_driver[i];
3330 
3331 		if (con_driver->con == NULL) {
3332 			con_driver->con = conswitchp;
3333 			con_driver->desc = display_desc;
3334 			con_driver->flag = CON_DRIVER_FLAG_INIT;
3335 			con_driver->first = 0;
3336 			con_driver->last = MAX_NR_CONSOLES - 1;
3337 			break;
3338 		}
3339 	}
3340 
3341 	for (i = 0; i < MAX_NR_CONSOLES; i++)
3342 		con_driver_map[i] = conswitchp;
3343 
3344 	if (blankinterval) {
3345 		blank_state = blank_normal_wait;
3346 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3347 	}
3348 
3349 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3350 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3351 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3352 		tty_port_init(&vc->port);
3353 		visual_init(vc, currcons, 1);
3354 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3355 		vc_init(vc, vc->vc_rows, vc->vc_cols,
3356 			currcons || !vc->vc_sw->con_save_screen);
3357 	}
3358 	currcons = fg_console = 0;
3359 	master_display_fg = vc = vc_cons[currcons].d;
3360 	set_origin(vc);
3361 	save_screen(vc);
3362 	gotoxy(vc, vc->vc_x, vc->vc_y);
3363 	csi_J(vc, 0);
3364 	update_screen(vc);
3365 	pr_info("Console: %s %s %dx%d\n",
3366 		vc->vc_can_do_color ? "colour" : "mono",
3367 		display_desc, vc->vc_cols, vc->vc_rows);
3368 	printable = 1;
3369 
3370 	console_unlock();
3371 
3372 #ifdef CONFIG_VT_CONSOLE
3373 	register_console(&vt_console_driver);
3374 #endif
3375 	return 0;
3376 }
3377 console_initcall(con_init);
3378 
3379 static const struct tty_operations con_ops = {
3380 	.install = con_install,
3381 	.open = con_open,
3382 	.close = con_close,
3383 	.write = con_write,
3384 	.write_room = con_write_room,
3385 	.put_char = con_put_char,
3386 	.flush_chars = con_flush_chars,
3387 	.chars_in_buffer = con_chars_in_buffer,
3388 	.ioctl = vt_ioctl,
3389 #ifdef CONFIG_COMPAT
3390 	.compat_ioctl = vt_compat_ioctl,
3391 #endif
3392 	.stop = con_stop,
3393 	.start = con_start,
3394 	.throttle = con_throttle,
3395 	.unthrottle = con_unthrottle,
3396 	.resize = vt_resize,
3397 	.shutdown = con_shutdown
3398 };
3399 
3400 static struct cdev vc0_cdev;
3401 
3402 static ssize_t show_tty_active(struct device *dev,
3403 				struct device_attribute *attr, char *buf)
3404 {
3405 	return sprintf(buf, "tty%d\n", fg_console + 1);
3406 }
3407 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3408 
3409 static struct attribute *vt_dev_attrs[] = {
3410 	&dev_attr_active.attr,
3411 	NULL
3412 };
3413 
3414 ATTRIBUTE_GROUPS(vt_dev);
3415 
3416 int __init vty_init(const struct file_operations *console_fops)
3417 {
3418 	cdev_init(&vc0_cdev, console_fops);
3419 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3420 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3421 		panic("Couldn't register /dev/tty0 driver\n");
3422 	tty0dev = device_create_with_groups(tty_class, NULL,
3423 					    MKDEV(TTY_MAJOR, 0), NULL,
3424 					    vt_dev_groups, "tty0");
3425 	if (IS_ERR(tty0dev))
3426 		tty0dev = NULL;
3427 
3428 	vcs_init();
3429 
3430 	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3431 	if (!console_driver)
3432 		panic("Couldn't allocate console driver\n");
3433 
3434 	console_driver->name = "tty";
3435 	console_driver->name_base = 1;
3436 	console_driver->major = TTY_MAJOR;
3437 	console_driver->minor_start = 1;
3438 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3439 	console_driver->init_termios = tty_std_termios;
3440 	if (default_utf8)
3441 		console_driver->init_termios.c_iflag |= IUTF8;
3442 	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3443 	tty_set_operations(console_driver, &con_ops);
3444 	if (tty_register_driver(console_driver))
3445 		panic("Couldn't register console driver\n");
3446 	kbd_init();
3447 	console_map_init();
3448 #ifdef CONFIG_MDA_CONSOLE
3449 	mda_console_init();
3450 #endif
3451 	return 0;
3452 }
3453 
3454 #ifndef VT_SINGLE_DRIVER
3455 
3456 static struct class *vtconsole_class;
3457 
3458 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3459 			   int deflt)
3460 {
3461 	struct module *owner = csw->owner;
3462 	const char *desc = NULL;
3463 	struct con_driver *con_driver;
3464 	int i, j = -1, k = -1, retval = -ENODEV;
3465 
3466 	if (!try_module_get(owner))
3467 		return -ENODEV;
3468 
3469 	WARN_CONSOLE_UNLOCKED();
3470 
3471 	/* check if driver is registered */
3472 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3473 		con_driver = &registered_con_driver[i];
3474 
3475 		if (con_driver->con == csw) {
3476 			desc = con_driver->desc;
3477 			retval = 0;
3478 			break;
3479 		}
3480 	}
3481 
3482 	if (retval)
3483 		goto err;
3484 
3485 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3486 		csw->con_startup();
3487 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3488 	}
3489 
3490 	if (deflt) {
3491 		if (conswitchp)
3492 			module_put(conswitchp->owner);
3493 
3494 		__module_get(owner);
3495 		conswitchp = csw;
3496 	}
3497 
3498 	first = max(first, con_driver->first);
3499 	last = min(last, con_driver->last);
3500 
3501 	for (i = first; i <= last; i++) {
3502 		int old_was_color;
3503 		struct vc_data *vc = vc_cons[i].d;
3504 
3505 		if (con_driver_map[i])
3506 			module_put(con_driver_map[i]->owner);
3507 		__module_get(owner);
3508 		con_driver_map[i] = csw;
3509 
3510 		if (!vc || !vc->vc_sw)
3511 			continue;
3512 
3513 		j = i;
3514 
3515 		if (con_is_visible(vc)) {
3516 			k = i;
3517 			save_screen(vc);
3518 		}
3519 
3520 		old_was_color = vc->vc_can_do_color;
3521 		vc->vc_sw->con_deinit(vc);
3522 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3523 		visual_init(vc, i, 0);
3524 		set_origin(vc);
3525 		update_attr(vc);
3526 
3527 		/* If the console changed between mono <-> color, then
3528 		 * the attributes in the screenbuf will be wrong.  The
3529 		 * following resets all attributes to something sane.
3530 		 */
3531 		if (old_was_color != vc->vc_can_do_color)
3532 			clear_buffer_attributes(vc);
3533 	}
3534 
3535 	pr_info("Console: switching ");
3536 	if (!deflt)
3537 		pr_cont("consoles %d-%d ", first + 1, last + 1);
3538 	if (j >= 0) {
3539 		struct vc_data *vc = vc_cons[j].d;
3540 
3541 		pr_cont("to %s %s %dx%d\n",
3542 			vc->vc_can_do_color ? "colour" : "mono",
3543 			desc, vc->vc_cols, vc->vc_rows);
3544 
3545 		if (k >= 0) {
3546 			vc = vc_cons[k].d;
3547 			update_screen(vc);
3548 		}
3549 	} else {
3550 		pr_cont("to %s\n", desc);
3551 	}
3552 
3553 	retval = 0;
3554 err:
3555 	module_put(owner);
3556 	return retval;
3557 };
3558 
3559 
3560 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3561 /* unlocked version of unbind_con_driver() */
3562 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3563 {
3564 	struct module *owner = csw->owner;
3565 	const struct consw *defcsw = NULL;
3566 	struct con_driver *con_driver = NULL, *con_back = NULL;
3567 	int i, retval = -ENODEV;
3568 
3569 	if (!try_module_get(owner))
3570 		return -ENODEV;
3571 
3572 	WARN_CONSOLE_UNLOCKED();
3573 
3574 	/* check if driver is registered and if it is unbindable */
3575 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3576 		con_driver = &registered_con_driver[i];
3577 
3578 		if (con_driver->con == csw &&
3579 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3580 			retval = 0;
3581 			break;
3582 		}
3583 	}
3584 
3585 	if (retval)
3586 		goto err;
3587 
3588 	retval = -ENODEV;
3589 
3590 	/* check if backup driver exists */
3591 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3592 		con_back = &registered_con_driver[i];
3593 
3594 		if (con_back->con && con_back->con != csw) {
3595 			defcsw = con_back->con;
3596 			retval = 0;
3597 			break;
3598 		}
3599 	}
3600 
3601 	if (retval)
3602 		goto err;
3603 
3604 	if (!con_is_bound(csw))
3605 		goto err;
3606 
3607 	first = max(first, con_driver->first);
3608 	last = min(last, con_driver->last);
3609 
3610 	for (i = first; i <= last; i++) {
3611 		if (con_driver_map[i] == csw) {
3612 			module_put(csw->owner);
3613 			con_driver_map[i] = NULL;
3614 		}
3615 	}
3616 
3617 	if (!con_is_bound(defcsw)) {
3618 		const struct consw *defconsw = conswitchp;
3619 
3620 		defcsw->con_startup();
3621 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3622 		/*
3623 		 * vgacon may change the default driver to point
3624 		 * to dummycon, we restore it here...
3625 		 */
3626 		conswitchp = defconsw;
3627 	}
3628 
3629 	if (!con_is_bound(csw))
3630 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3631 
3632 	/* ignore return value, binding should not fail */
3633 	do_bind_con_driver(defcsw, first, last, deflt);
3634 err:
3635 	module_put(owner);
3636 	return retval;
3637 
3638 }
3639 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3640 
3641 static int vt_bind(struct con_driver *con)
3642 {
3643 	const struct consw *defcsw = NULL, *csw = NULL;
3644 	int i, more = 1, first = -1, last = -1, deflt = 0;
3645 
3646  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3647 		goto err;
3648 
3649 	csw = con->con;
3650 
3651 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3652 		struct con_driver *con = &registered_con_driver[i];
3653 
3654 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3655 			defcsw = con->con;
3656 			break;
3657 		}
3658 	}
3659 
3660 	if (!defcsw)
3661 		goto err;
3662 
3663 	while (more) {
3664 		more = 0;
3665 
3666 		for (i = con->first; i <= con->last; i++) {
3667 			if (con_driver_map[i] == defcsw) {
3668 				if (first == -1)
3669 					first = i;
3670 				last = i;
3671 				more = 1;
3672 			} else if (first != -1)
3673 				break;
3674 		}
3675 
3676 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3677 			deflt = 1;
3678 
3679 		if (first != -1)
3680 			do_bind_con_driver(csw, first, last, deflt);
3681 
3682 		first = -1;
3683 		last = -1;
3684 		deflt = 0;
3685 	}
3686 
3687 err:
3688 	return 0;
3689 }
3690 
3691 static int vt_unbind(struct con_driver *con)
3692 {
3693 	const struct consw *csw = NULL;
3694 	int i, more = 1, first = -1, last = -1, deflt = 0;
3695 	int ret;
3696 
3697  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3698 		goto err;
3699 
3700 	csw = con->con;
3701 
3702 	while (more) {
3703 		more = 0;
3704 
3705 		for (i = con->first; i <= con->last; i++) {
3706 			if (con_driver_map[i] == csw) {
3707 				if (first == -1)
3708 					first = i;
3709 				last = i;
3710 				more = 1;
3711 			} else if (first != -1)
3712 				break;
3713 		}
3714 
3715 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3716 			deflt = 1;
3717 
3718 		if (first != -1) {
3719 			ret = do_unbind_con_driver(csw, first, last, deflt);
3720 			if (ret != 0)
3721 				return ret;
3722 		}
3723 
3724 		first = -1;
3725 		last = -1;
3726 		deflt = 0;
3727 	}
3728 
3729 err:
3730 	return 0;
3731 }
3732 #else
3733 static inline int vt_bind(struct con_driver *con)
3734 {
3735 	return 0;
3736 }
3737 static inline int vt_unbind(struct con_driver *con)
3738 {
3739 	return 0;
3740 }
3741 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3742 
3743 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3744 			  const char *buf, size_t count)
3745 {
3746 	struct con_driver *con = dev_get_drvdata(dev);
3747 	int bind = simple_strtoul(buf, NULL, 0);
3748 
3749 	console_lock();
3750 
3751 	if (bind)
3752 		vt_bind(con);
3753 	else
3754 		vt_unbind(con);
3755 
3756 	console_unlock();
3757 
3758 	return count;
3759 }
3760 
3761 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3762 			 char *buf)
3763 {
3764 	struct con_driver *con = dev_get_drvdata(dev);
3765 	int bind = con_is_bound(con->con);
3766 
3767 	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3768 }
3769 
3770 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3771 			 char *buf)
3772 {
3773 	struct con_driver *con = dev_get_drvdata(dev);
3774 
3775 	return snprintf(buf, PAGE_SIZE, "%s %s\n",
3776 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3777 			 con->desc);
3778 
3779 }
3780 
3781 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3782 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3783 
3784 static struct attribute *con_dev_attrs[] = {
3785 	&dev_attr_bind.attr,
3786 	&dev_attr_name.attr,
3787 	NULL
3788 };
3789 
3790 ATTRIBUTE_GROUPS(con_dev);
3791 
3792 static int vtconsole_init_device(struct con_driver *con)
3793 {
3794 	con->flag |= CON_DRIVER_FLAG_ATTR;
3795 	return 0;
3796 }
3797 
3798 static void vtconsole_deinit_device(struct con_driver *con)
3799 {
3800 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3801 }
3802 
3803 /**
3804  * con_is_bound - checks if driver is bound to the console
3805  * @csw: console driver
3806  *
3807  * RETURNS: zero if unbound, nonzero if bound
3808  *
3809  * Drivers can call this and if zero, they should release
3810  * all resources allocated on con_startup()
3811  */
3812 int con_is_bound(const struct consw *csw)
3813 {
3814 	int i, bound = 0;
3815 
3816 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3817 		if (con_driver_map[i] == csw) {
3818 			bound = 1;
3819 			break;
3820 		}
3821 	}
3822 
3823 	return bound;
3824 }
3825 EXPORT_SYMBOL(con_is_bound);
3826 
3827 /**
3828  * con_debug_enter - prepare the console for the kernel debugger
3829  * @sw: console driver
3830  *
3831  * Called when the console is taken over by the kernel debugger, this
3832  * function needs to save the current console state, then put the console
3833  * into a state suitable for the kernel debugger.
3834  *
3835  * RETURNS:
3836  * Zero on success, nonzero if a failure occurred when trying to prepare
3837  * the console for the debugger.
3838  */
3839 int con_debug_enter(struct vc_data *vc)
3840 {
3841 	int ret = 0;
3842 
3843 	saved_fg_console = fg_console;
3844 	saved_last_console = last_console;
3845 	saved_want_console = want_console;
3846 	saved_vc_mode = vc->vc_mode;
3847 	saved_console_blanked = console_blanked;
3848 	vc->vc_mode = KD_TEXT;
3849 	console_blanked = 0;
3850 	if (vc->vc_sw->con_debug_enter)
3851 		ret = vc->vc_sw->con_debug_enter(vc);
3852 #ifdef CONFIG_KGDB_KDB
3853 	/* Set the initial LINES variable if it is not already set */
3854 	if (vc->vc_rows < 999) {
3855 		int linecount;
3856 		char lns[4];
3857 		const char *setargs[3] = {
3858 			"set",
3859 			"LINES",
3860 			lns,
3861 		};
3862 		if (kdbgetintenv(setargs[0], &linecount)) {
3863 			snprintf(lns, 4, "%i", vc->vc_rows);
3864 			kdb_set(2, setargs);
3865 		}
3866 	}
3867 	if (vc->vc_cols < 999) {
3868 		int colcount;
3869 		char cols[4];
3870 		const char *setargs[3] = {
3871 			"set",
3872 			"COLUMNS",
3873 			cols,
3874 		};
3875 		if (kdbgetintenv(setargs[0], &colcount)) {
3876 			snprintf(cols, 4, "%i", vc->vc_cols);
3877 			kdb_set(2, setargs);
3878 		}
3879 	}
3880 #endif /* CONFIG_KGDB_KDB */
3881 	return ret;
3882 }
3883 EXPORT_SYMBOL_GPL(con_debug_enter);
3884 
3885 /**
3886  * con_debug_leave - restore console state
3887  * @sw: console driver
3888  *
3889  * Restore the console state to what it was before the kernel debugger
3890  * was invoked.
3891  *
3892  * RETURNS:
3893  * Zero on success, nonzero if a failure occurred when trying to restore
3894  * the console.
3895  */
3896 int con_debug_leave(void)
3897 {
3898 	struct vc_data *vc;
3899 	int ret = 0;
3900 
3901 	fg_console = saved_fg_console;
3902 	last_console = saved_last_console;
3903 	want_console = saved_want_console;
3904 	console_blanked = saved_console_blanked;
3905 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3906 
3907 	vc = vc_cons[fg_console].d;
3908 	if (vc->vc_sw->con_debug_leave)
3909 		ret = vc->vc_sw->con_debug_leave(vc);
3910 	return ret;
3911 }
3912 EXPORT_SYMBOL_GPL(con_debug_leave);
3913 
3914 static int do_register_con_driver(const struct consw *csw, int first, int last)
3915 {
3916 	struct module *owner = csw->owner;
3917 	struct con_driver *con_driver;
3918 	const char *desc;
3919 	int i, retval;
3920 
3921 	WARN_CONSOLE_UNLOCKED();
3922 
3923 	if (!try_module_get(owner))
3924 		return -ENODEV;
3925 
3926 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3927 		con_driver = &registered_con_driver[i];
3928 
3929 		/* already registered */
3930 		if (con_driver->con == csw) {
3931 			retval = -EBUSY;
3932 			goto err;
3933 		}
3934 	}
3935 
3936 	desc = csw->con_startup();
3937 	if (!desc) {
3938 		retval = -ENODEV;
3939 		goto err;
3940 	}
3941 
3942 	retval = -EINVAL;
3943 
3944 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3945 		con_driver = &registered_con_driver[i];
3946 
3947 		if (con_driver->con == NULL &&
3948 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3949 			con_driver->con = csw;
3950 			con_driver->desc = desc;
3951 			con_driver->node = i;
3952 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
3953 			                   CON_DRIVER_FLAG_INIT;
3954 			con_driver->first = first;
3955 			con_driver->last = last;
3956 			retval = 0;
3957 			break;
3958 		}
3959 	}
3960 
3961 	if (retval)
3962 		goto err;
3963 
3964 	con_driver->dev =
3965 		device_create_with_groups(vtconsole_class, NULL,
3966 					  MKDEV(0, con_driver->node),
3967 					  con_driver, con_dev_groups,
3968 					  "vtcon%i", con_driver->node);
3969 	if (IS_ERR(con_driver->dev)) {
3970 		pr_warn("Unable to create device for %s; errno = %ld\n",
3971 			con_driver->desc, PTR_ERR(con_driver->dev));
3972 		con_driver->dev = NULL;
3973 	} else {
3974 		vtconsole_init_device(con_driver);
3975 	}
3976 
3977 err:
3978 	module_put(owner);
3979 	return retval;
3980 }
3981 
3982 
3983 /**
3984  * do_unregister_con_driver - unregister console driver from console layer
3985  * @csw: console driver
3986  *
3987  * DESCRIPTION: All drivers that registers to the console layer must
3988  * call this function upon exit, or if the console driver is in a state
3989  * where it won't be able to handle console services, such as the
3990  * framebuffer console without loaded framebuffer drivers.
3991  *
3992  * The driver must unbind first prior to unregistration.
3993  */
3994 int do_unregister_con_driver(const struct consw *csw)
3995 {
3996 	int i;
3997 
3998 	/* cannot unregister a bound driver */
3999 	if (con_is_bound(csw))
4000 		return -EBUSY;
4001 
4002 	if (csw == conswitchp)
4003 		return -EINVAL;
4004 
4005 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4006 		struct con_driver *con_driver = &registered_con_driver[i];
4007 
4008 		if (con_driver->con == csw) {
4009 			/*
4010 			 * Defer the removal of the sysfs entries since that
4011 			 * will acquire the kernfs s_active lock and we can't
4012 			 * acquire this lock while holding the console lock:
4013 			 * the unbind sysfs entry imposes already the opposite
4014 			 * order. Reset con already here to prevent any later
4015 			 * lookup to succeed and mark this slot as zombie, so
4016 			 * it won't get reused until we complete the removal
4017 			 * in the deferred work.
4018 			 */
4019 			con_driver->con = NULL;
4020 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4021 			schedule_work(&con_driver_unregister_work);
4022 
4023 			return 0;
4024 		}
4025 	}
4026 
4027 	return -ENODEV;
4028 }
4029 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4030 
4031 static void con_driver_unregister_callback(struct work_struct *ignored)
4032 {
4033 	int i;
4034 
4035 	console_lock();
4036 
4037 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4038 		struct con_driver *con_driver = &registered_con_driver[i];
4039 
4040 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4041 			continue;
4042 
4043 		console_unlock();
4044 
4045 		vtconsole_deinit_device(con_driver);
4046 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4047 
4048 		console_lock();
4049 
4050 		if (WARN_ON_ONCE(con_driver->con))
4051 			con_driver->con = NULL;
4052 		con_driver->desc = NULL;
4053 		con_driver->dev = NULL;
4054 		con_driver->node = 0;
4055 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4056 		con_driver->flag = 0;
4057 		con_driver->first = 0;
4058 		con_driver->last = 0;
4059 	}
4060 
4061 	console_unlock();
4062 }
4063 
4064 /*
4065  *	If we support more console drivers, this function is used
4066  *	when a driver wants to take over some existing consoles
4067  *	and become default driver for newly opened ones.
4068  *
4069  *	do_take_over_console is basically a register followed by unbind
4070  */
4071 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4072 {
4073 	int err;
4074 
4075 	err = do_register_con_driver(csw, first, last);
4076 	/*
4077 	 * If we get an busy error we still want to bind the console driver
4078 	 * and return success, as we may have unbound the console driver
4079 	 * but not unregistered it.
4080 	 */
4081 	if (err == -EBUSY)
4082 		err = 0;
4083 	if (!err)
4084 		do_bind_con_driver(csw, first, last, deflt);
4085 
4086 	return err;
4087 }
4088 EXPORT_SYMBOL_GPL(do_take_over_console);
4089 
4090 
4091 /*
4092  * give_up_console is a wrapper to unregister_con_driver. It will only
4093  * work if driver is fully unbound.
4094  */
4095 void give_up_console(const struct consw *csw)
4096 {
4097 	console_lock();
4098 	do_unregister_con_driver(csw);
4099 	console_unlock();
4100 }
4101 
4102 static int __init vtconsole_class_init(void)
4103 {
4104 	int i;
4105 
4106 	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4107 	if (IS_ERR(vtconsole_class)) {
4108 		pr_warn("Unable to create vt console class; errno = %ld\n",
4109 			PTR_ERR(vtconsole_class));
4110 		vtconsole_class = NULL;
4111 	}
4112 
4113 	/* Add system drivers to sysfs */
4114 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4115 		struct con_driver *con = &registered_con_driver[i];
4116 
4117 		if (con->con && !con->dev) {
4118 			con->dev =
4119 				device_create_with_groups(vtconsole_class, NULL,
4120 							  MKDEV(0, con->node),
4121 							  con, con_dev_groups,
4122 							  "vtcon%i", con->node);
4123 
4124 			if (IS_ERR(con->dev)) {
4125 				pr_warn("Unable to create device for %s; errno = %ld\n",
4126 					con->desc, PTR_ERR(con->dev));
4127 				con->dev = NULL;
4128 			} else {
4129 				vtconsole_init_device(con);
4130 			}
4131 		}
4132 	}
4133 
4134 	return 0;
4135 }
4136 postcore_initcall(vtconsole_class_init);
4137 
4138 #endif
4139 
4140 /*
4141  *	Screen blanking
4142  */
4143 
4144 static int set_vesa_blanking(char __user *p)
4145 {
4146 	unsigned int mode;
4147 
4148 	if (get_user(mode, p + 1))
4149 		return -EFAULT;
4150 
4151 	vesa_blank_mode = (mode < 4) ? mode : 0;
4152 	return 0;
4153 }
4154 
4155 void do_blank_screen(int entering_gfx)
4156 {
4157 	struct vc_data *vc = vc_cons[fg_console].d;
4158 	int i;
4159 
4160 	WARN_CONSOLE_UNLOCKED();
4161 
4162 	if (console_blanked) {
4163 		if (blank_state == blank_vesa_wait) {
4164 			blank_state = blank_off;
4165 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4166 		}
4167 		return;
4168 	}
4169 
4170 	/* entering graphics mode? */
4171 	if (entering_gfx) {
4172 		hide_cursor(vc);
4173 		save_screen(vc);
4174 		vc->vc_sw->con_blank(vc, -1, 1);
4175 		console_blanked = fg_console + 1;
4176 		blank_state = blank_off;
4177 		set_origin(vc);
4178 		return;
4179 	}
4180 
4181 	if (blank_state != blank_normal_wait)
4182 		return;
4183 	blank_state = blank_off;
4184 
4185 	/* don't blank graphics */
4186 	if (vc->vc_mode != KD_TEXT) {
4187 		console_blanked = fg_console + 1;
4188 		return;
4189 	}
4190 
4191 	hide_cursor(vc);
4192 	del_timer_sync(&console_timer);
4193 	blank_timer_expired = 0;
4194 
4195 	save_screen(vc);
4196 	/* In case we need to reset origin, blanking hook returns 1 */
4197 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4198 	console_blanked = fg_console + 1;
4199 	if (i)
4200 		set_origin(vc);
4201 
4202 	if (console_blank_hook && console_blank_hook(1))
4203 		return;
4204 
4205 	if (vesa_off_interval && vesa_blank_mode) {
4206 		blank_state = blank_vesa_wait;
4207 		mod_timer(&console_timer, jiffies + vesa_off_interval);
4208 	}
4209 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4210 }
4211 EXPORT_SYMBOL(do_blank_screen);
4212 
4213 /*
4214  * Called by timer as well as from vt_console_driver
4215  */
4216 void do_unblank_screen(int leaving_gfx)
4217 {
4218 	struct vc_data *vc;
4219 
4220 	/* This should now always be called from a "sane" (read: can schedule)
4221 	 * context for the sake of the low level drivers, except in the special
4222 	 * case of oops_in_progress
4223 	 */
4224 	if (!oops_in_progress)
4225 		might_sleep();
4226 
4227 	WARN_CONSOLE_UNLOCKED();
4228 
4229 	ignore_poke = 0;
4230 	if (!console_blanked)
4231 		return;
4232 	if (!vc_cons_allocated(fg_console)) {
4233 		/* impossible */
4234 		pr_warn("unblank_screen: tty %d not allocated ??\n",
4235 			fg_console + 1);
4236 		return;
4237 	}
4238 	vc = vc_cons[fg_console].d;
4239 	if (vc->vc_mode != KD_TEXT)
4240 		return; /* but leave console_blanked != 0 */
4241 
4242 	if (blankinterval) {
4243 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4244 		blank_state = blank_normal_wait;
4245 	}
4246 
4247 	console_blanked = 0;
4248 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4249 		/* Low-level driver cannot restore -> do it ourselves */
4250 		update_screen(vc);
4251 	if (console_blank_hook)
4252 		console_blank_hook(0);
4253 	set_palette(vc);
4254 	set_cursor(vc);
4255 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4256 }
4257 EXPORT_SYMBOL(do_unblank_screen);
4258 
4259 /*
4260  * This is called by the outside world to cause a forced unblank, mostly for
4261  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4262  * call it with 1 as an argument and so force a mode restore... that may kill
4263  * X or at least garbage the screen but would also make the Oops visible...
4264  */
4265 void unblank_screen(void)
4266 {
4267 	do_unblank_screen(0);
4268 }
4269 
4270 /*
4271  * We defer the timer blanking to work queue so it can take the console mutex
4272  * (console operations can still happen at irq time, but only from printk which
4273  * has the console mutex. Not perfect yet, but better than no locking
4274  */
4275 static void blank_screen_t(struct timer_list *unused)
4276 {
4277 	blank_timer_expired = 1;
4278 	schedule_work(&console_work);
4279 }
4280 
4281 void poke_blanked_console(void)
4282 {
4283 	WARN_CONSOLE_UNLOCKED();
4284 
4285 	/* Add this so we quickly catch whoever might call us in a non
4286 	 * safe context. Nowadays, unblank_screen() isn't to be called in
4287 	 * atomic contexts and is allowed to schedule (with the special case
4288 	 * of oops_in_progress, but that isn't of any concern for this
4289 	 * function. --BenH.
4290 	 */
4291 	might_sleep();
4292 
4293 	/* This isn't perfectly race free, but a race here would be mostly harmless,
4294 	 * at worse, we'll do a spurrious blank and it's unlikely
4295 	 */
4296 	del_timer(&console_timer);
4297 	blank_timer_expired = 0;
4298 
4299 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4300 		return;
4301 	if (console_blanked)
4302 		unblank_screen();
4303 	else if (blankinterval) {
4304 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4305 		blank_state = blank_normal_wait;
4306 	}
4307 }
4308 
4309 /*
4310  *	Palettes
4311  */
4312 
4313 static void set_palette(struct vc_data *vc)
4314 {
4315 	WARN_CONSOLE_UNLOCKED();
4316 
4317 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4318 		vc->vc_sw->con_set_palette(vc, color_table);
4319 }
4320 
4321 /*
4322  * Load palette into the DAC registers. arg points to a colour
4323  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4324  */
4325 
4326 int con_set_cmap(unsigned char __user *arg)
4327 {
4328 	int i, j, k;
4329 	unsigned char colormap[3*16];
4330 
4331 	if (copy_from_user(colormap, arg, sizeof(colormap)))
4332 		return -EFAULT;
4333 
4334 	console_lock();
4335 	for (i = k = 0; i < 16; i++) {
4336 		default_red[i] = colormap[k++];
4337 		default_grn[i] = colormap[k++];
4338 		default_blu[i] = colormap[k++];
4339 	}
4340 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
4341 		if (!vc_cons_allocated(i))
4342 			continue;
4343 		for (j = k = 0; j < 16; j++) {
4344 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4345 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4346 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4347 		}
4348 		set_palette(vc_cons[i].d);
4349 	}
4350 	console_unlock();
4351 
4352 	return 0;
4353 }
4354 
4355 int con_get_cmap(unsigned char __user *arg)
4356 {
4357 	int i, k;
4358 	unsigned char colormap[3*16];
4359 
4360 	console_lock();
4361 	for (i = k = 0; i < 16; i++) {
4362 		colormap[k++] = default_red[i];
4363 		colormap[k++] = default_grn[i];
4364 		colormap[k++] = default_blu[i];
4365 	}
4366 	console_unlock();
4367 
4368 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4369 		return -EFAULT;
4370 
4371 	return 0;
4372 }
4373 
4374 void reset_palette(struct vc_data *vc)
4375 {
4376 	int j, k;
4377 	for (j=k=0; j<16; j++) {
4378 		vc->vc_palette[k++] = default_red[j];
4379 		vc->vc_palette[k++] = default_grn[j];
4380 		vc->vc_palette[k++] = default_blu[j];
4381 	}
4382 	set_palette(vc);
4383 }
4384 
4385 /*
4386  *  Font switching
4387  *
4388  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4389  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4390  *  depending on width) reserved for each character which is kinda wasty, but
4391  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4392  *  is up to the actual low-level console-driver convert data into its favorite
4393  *  format (maybe we should add a `fontoffset' field to the `display'
4394  *  structure so we won't have to convert the fontdata all the time.
4395  *  /Jes
4396  */
4397 
4398 #define max_font_size 65536
4399 
4400 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4401 {
4402 	struct console_font font;
4403 	int rc = -EINVAL;
4404 	int c;
4405 
4406 	if (op->data) {
4407 		font.data = kmalloc(max_font_size, GFP_KERNEL);
4408 		if (!font.data)
4409 			return -ENOMEM;
4410 	} else
4411 		font.data = NULL;
4412 
4413 	console_lock();
4414 	if (vc->vc_mode != KD_TEXT)
4415 		rc = -EINVAL;
4416 	else if (vc->vc_sw->con_font_get)
4417 		rc = vc->vc_sw->con_font_get(vc, &font);
4418 	else
4419 		rc = -ENOSYS;
4420 	console_unlock();
4421 
4422 	if (rc)
4423 		goto out;
4424 
4425 	c = (font.width+7)/8 * 32 * font.charcount;
4426 
4427 	if (op->data && font.charcount > op->charcount)
4428 		rc = -ENOSPC;
4429 	if (!(op->flags & KD_FONT_FLAG_OLD)) {
4430 		if (font.width > op->width || font.height > op->height)
4431 			rc = -ENOSPC;
4432 	} else {
4433 		if (font.width != 8)
4434 			rc = -EIO;
4435 		else if ((op->height && font.height > op->height) ||
4436 			 font.height > 32)
4437 			rc = -ENOSPC;
4438 	}
4439 	if (rc)
4440 		goto out;
4441 
4442 	op->height = font.height;
4443 	op->width = font.width;
4444 	op->charcount = font.charcount;
4445 
4446 	if (op->data && copy_to_user(op->data, font.data, c))
4447 		rc = -EFAULT;
4448 
4449 out:
4450 	kfree(font.data);
4451 	return rc;
4452 }
4453 
4454 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4455 {
4456 	struct console_font font;
4457 	int rc = -EINVAL;
4458 	int size;
4459 
4460 	if (vc->vc_mode != KD_TEXT)
4461 		return -EINVAL;
4462 	if (!op->data)
4463 		return -EINVAL;
4464 	if (op->charcount > 512)
4465 		return -EINVAL;
4466 	if (op->width <= 0 || op->width > 32 || op->height > 32)
4467 		return -EINVAL;
4468 	size = (op->width+7)/8 * 32 * op->charcount;
4469 	if (size > max_font_size)
4470 		return -ENOSPC;
4471 
4472 	font.data = memdup_user(op->data, size);
4473 	if (IS_ERR(font.data))
4474 		return PTR_ERR(font.data);
4475 
4476 	if (!op->height) {		/* Need to guess font height [compat] */
4477 		int h, i;
4478 		u8 *charmap = font.data;
4479 
4480 		/*
4481 		 * If from KDFONTOP ioctl, don't allow things which can be done
4482 		 * in userland,so that we can get rid of this soon
4483 		 */
4484 		if (!(op->flags & KD_FONT_FLAG_OLD)) {
4485 			kfree(font.data);
4486 			return -EINVAL;
4487 		}
4488 
4489 		for (h = 32; h > 0; h--)
4490 			for (i = 0; i < op->charcount; i++)
4491 				if (charmap[32*i+h-1])
4492 					goto nonzero;
4493 
4494 		kfree(font.data);
4495 		return -EINVAL;
4496 
4497 	nonzero:
4498 		op->height = h;
4499 	}
4500 
4501 	font.charcount = op->charcount;
4502 	font.width = op->width;
4503 	font.height = op->height;
4504 
4505 	console_lock();
4506 	if (vc->vc_mode != KD_TEXT)
4507 		rc = -EINVAL;
4508 	else if (vc->vc_sw->con_font_set)
4509 		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4510 	else
4511 		rc = -ENOSYS;
4512 	console_unlock();
4513 	kfree(font.data);
4514 	return rc;
4515 }
4516 
4517 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4518 {
4519 	struct console_font font = {.width = op->width, .height = op->height};
4520 	char name[MAX_FONT_NAME];
4521 	char *s = name;
4522 	int rc;
4523 
4524 
4525 	if (!op->data)
4526 		s = NULL;
4527 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4528 		return -EFAULT;
4529 	else
4530 		name[MAX_FONT_NAME - 1] = 0;
4531 
4532 	console_lock();
4533 	if (vc->vc_mode != KD_TEXT) {
4534 		console_unlock();
4535 		return -EINVAL;
4536 	}
4537 	if (vc->vc_sw->con_font_default)
4538 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4539 	else
4540 		rc = -ENOSYS;
4541 	console_unlock();
4542 	if (!rc) {
4543 		op->width = font.width;
4544 		op->height = font.height;
4545 	}
4546 	return rc;
4547 }
4548 
4549 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4550 {
4551 	int con = op->height;
4552 	int rc;
4553 
4554 
4555 	console_lock();
4556 	if (vc->vc_mode != KD_TEXT)
4557 		rc = -EINVAL;
4558 	else if (!vc->vc_sw->con_font_copy)
4559 		rc = -ENOSYS;
4560 	else if (con < 0 || !vc_cons_allocated(con))
4561 		rc = -ENOTTY;
4562 	else if (con == vc->vc_num)	/* nothing to do */
4563 		rc = 0;
4564 	else
4565 		rc = vc->vc_sw->con_font_copy(vc, con);
4566 	console_unlock();
4567 	return rc;
4568 }
4569 
4570 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4571 {
4572 	switch (op->op) {
4573 	case KD_FONT_OP_SET:
4574 		return con_font_set(vc, op);
4575 	case KD_FONT_OP_GET:
4576 		return con_font_get(vc, op);
4577 	case KD_FONT_OP_SET_DEFAULT:
4578 		return con_font_default(vc, op);
4579 	case KD_FONT_OP_COPY:
4580 		return con_font_copy(vc, op);
4581 	}
4582 	return -ENOSYS;
4583 }
4584 
4585 /*
4586  *	Interface exported to selection and vcs.
4587  */
4588 
4589 /* used by selection */
4590 u16 screen_glyph(struct vc_data *vc, int offset)
4591 {
4592 	u16 w = scr_readw(screenpos(vc, offset, 1));
4593 	u16 c = w & 0xff;
4594 
4595 	if (w & vc->vc_hi_font_mask)
4596 		c |= 0x100;
4597 	return c;
4598 }
4599 EXPORT_SYMBOL_GPL(screen_glyph);
4600 
4601 u32 screen_glyph_unicode(struct vc_data *vc, int n)
4602 {
4603 	struct uni_screen *uniscr = get_vc_uniscr(vc);
4604 
4605 	if (uniscr)
4606 		return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4607 	return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4608 }
4609 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4610 
4611 /* used by vcs - note the word offset */
4612 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4613 {
4614 	return screenpos(vc, 2 * w_offset, viewed);
4615 }
4616 EXPORT_SYMBOL_GPL(screen_pos);
4617 
4618 void getconsxy(struct vc_data *vc, unsigned char *p)
4619 {
4620 	/* clamp values if they don't fit */
4621 	p[0] = min(vc->vc_x, 0xFFu);
4622 	p[1] = min(vc->vc_y, 0xFFu);
4623 }
4624 
4625 void putconsxy(struct vc_data *vc, unsigned char *p)
4626 {
4627 	hide_cursor(vc);
4628 	gotoxy(vc, p[0], p[1]);
4629 	set_cursor(vc);
4630 }
4631 
4632 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4633 {
4634 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4635 		return softcursor_original;
4636 	return scr_readw(org);
4637 }
4638 
4639 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4640 {
4641 	scr_writew(val, org);
4642 	if ((unsigned long)org == vc->vc_pos) {
4643 		softcursor_original = -1;
4644 		add_softcursor(vc);
4645 	}
4646 }
4647 
4648 void vcs_scr_updated(struct vc_data *vc)
4649 {
4650 	notify_update(vc);
4651 }
4652 
4653 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4654 		unsigned int rolled_over, void *base, unsigned int size)
4655 {
4656 	unsigned long ubase = (unsigned long)base;
4657 	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4658 	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4659 	ptrdiff_t origin = (void *)c->vc_origin - base;
4660 	int margin = c->vc_size_row * 4;
4661 	int from, wrap, from_off, avail;
4662 
4663 	/* Turn scrollback off */
4664 	if (!lines) {
4665 		c->vc_visible_origin = c->vc_origin;
4666 		return;
4667 	}
4668 
4669 	/* Do we have already enough to allow jumping from 0 to the end? */
4670 	if (rolled_over > scr_end + margin) {
4671 		from = scr_end;
4672 		wrap = rolled_over + c->vc_size_row;
4673 	} else {
4674 		from = 0;
4675 		wrap = size;
4676 	}
4677 
4678 	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4679 	avail = (origin - from + wrap) % wrap;
4680 
4681 	/* Only a little piece would be left? Show all incl. the piece! */
4682 	if (avail < 2 * margin)
4683 		margin = 0;
4684 	if (from_off < margin)
4685 		from_off = 0;
4686 	if (from_off > avail - margin)
4687 		from_off = avail;
4688 
4689 	c->vc_visible_origin = ubase + (from + from_off) % wrap;
4690 }
4691 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4692 
4693 /*
4694  *	Visible symbols for modules
4695  */
4696 
4697 EXPORT_SYMBOL(color_table);
4698 EXPORT_SYMBOL(default_red);
4699 EXPORT_SYMBOL(default_grn);
4700 EXPORT_SYMBOL(default_blu);
4701 EXPORT_SYMBOL(update_region);
4702 EXPORT_SYMBOL(redraw_screen);
4703 EXPORT_SYMBOL(vc_resize);
4704 EXPORT_SYMBOL(fg_console);
4705 EXPORT_SYMBOL(console_blank_hook);
4706 EXPORT_SYMBOL(console_blanked);
4707 EXPORT_SYMBOL(vc_cons);
4708 EXPORT_SYMBOL(global_cursor_default);
4709 #ifndef VT_SINGLE_DRIVER
4710 EXPORT_SYMBOL(give_up_console);
4711 #endif
4712