xref: /openbmc/linux/drivers/tty/vt/vt.c (revision 1c2dd16a)
1 /*
2  *  Copyright (C) 1991, 1992  Linus Torvalds
3  */
4 
5 /*
6  * Hopefully this will be a rather complete VT102 implementation.
7  *
8  * Beeping thanks to John T Kohl.
9  *
10  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
11  *   Chars, and VT100 enhancements by Peter MacDonald.
12  *
13  * Copy and paste function by Andrew Haylett,
14  *   some enhancements by Alessandro Rubini.
15  *
16  * Code to check for different video-cards mostly by Galen Hunt,
17  * <g-hunt@ee.utah.edu>
18  *
19  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
20  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
21  *
22  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
23  * Resizing of consoles, aeb, 940926
24  *
25  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
26  * <poe@daimi.aau.dk>
27  *
28  * User-defined bell sound, new setterm control sequences and printk
29  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
30  *
31  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
32  *
33  * Merge with the abstract console driver by Geert Uytterhoeven
34  * <geert@linux-m68k.org>, Jan 1997.
35  *
36  *   Original m68k console driver modifications by
37  *
38  *     - Arno Griffioen <arno@usn.nl>
39  *     - David Carter <carter@cs.bris.ac.uk>
40  *
41  *   The abstract console driver provides a generic interface for a text
42  *   console. It supports VGA text mode, frame buffer based graphical consoles
43  *   and special graphics processors that are only accessible through some
44  *   registers (e.g. a TMS340x0 GSP).
45  *
46  *   The interface to the hardware is specified using a special structure
47  *   (struct consw) which contains function pointers to console operations
48  *   (see <linux/console.h> for more information).
49  *
50  * Support for changeable cursor shape
51  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
52  *
53  * Ported to i386 and con_scrolldelta fixed
54  * by Emmanuel Marty <core@ggi-project.org>, April 1998
55  *
56  * Resurrected character buffers in videoram plus lots of other trickery
57  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
58  *
59  * Removed old-style timers, introduced console_timer, made timer
60  * deletion SMP-safe.  17Jun00, Andrew Morton
61  *
62  * Removed console_lock, enabled interrupts across all console operations
63  * 13 March 2001, Andrew Morton
64  *
65  * Fixed UTF-8 mode so alternate charset modes always work according
66  * to control sequences interpreted in do_con_trol function
67  * preserving backward VT100 semigraphics compatibility,
68  * malformed UTF sequences represented as sequences of replacement glyphs,
69  * original codes or '?' as a last resort if replacement glyph is undefined
70  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
71  */
72 
73 #include <linux/module.h>
74 #include <linux/types.h>
75 #include <linux/sched/signal.h>
76 #include <linux/tty.h>
77 #include <linux/tty_flip.h>
78 #include <linux/kernel.h>
79 #include <linux/string.h>
80 #include <linux/errno.h>
81 #include <linux/kd.h>
82 #include <linux/slab.h>
83 #include <linux/major.h>
84 #include <linux/mm.h>
85 #include <linux/console.h>
86 #include <linux/init.h>
87 #include <linux/mutex.h>
88 #include <linux/vt_kern.h>
89 #include <linux/selection.h>
90 #include <linux/tiocl.h>
91 #include <linux/kbd_kern.h>
92 #include <linux/consolemap.h>
93 #include <linux/timer.h>
94 #include <linux/interrupt.h>
95 #include <linux/workqueue.h>
96 #include <linux/pm.h>
97 #include <linux/font.h>
98 #include <linux/bitops.h>
99 #include <linux/notifier.h>
100 #include <linux/device.h>
101 #include <linux/io.h>
102 #include <linux/uaccess.h>
103 #include <linux/kdb.h>
104 #include <linux/ctype.h>
105 
106 #define MAX_NR_CON_DRIVER 16
107 
108 #define CON_DRIVER_FLAG_MODULE 1
109 #define CON_DRIVER_FLAG_INIT   2
110 #define CON_DRIVER_FLAG_ATTR   4
111 #define CON_DRIVER_FLAG_ZOMBIE 8
112 
113 struct con_driver {
114 	const struct consw *con;
115 	const char *desc;
116 	struct device *dev;
117 	int node;
118 	int first;
119 	int last;
120 	int flag;
121 };
122 
123 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
124 const struct consw *conswitchp;
125 
126 /* A bitmap for codes <32. A bit of 1 indicates that the code
127  * corresponding to that bit number invokes some special action
128  * (such as cursor movement) and should not be displayed as a
129  * glyph unless the disp_ctrl mode is explicitly enabled.
130  */
131 #define CTRL_ACTION 0x0d00ff81
132 #define CTRL_ALWAYS 0x0800f501	/* Cannot be overridden by disp_ctrl */
133 
134 /*
135  * Here is the default bell parameters: 750HZ, 1/8th of a second
136  */
137 #define DEFAULT_BELL_PITCH	750
138 #define DEFAULT_BELL_DURATION	(HZ/8)
139 #define DEFAULT_CURSOR_BLINK_MS	200
140 
141 struct vc vc_cons [MAX_NR_CONSOLES];
142 
143 #ifndef VT_SINGLE_DRIVER
144 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
145 #endif
146 
147 static int con_open(struct tty_struct *, struct file *);
148 static void vc_init(struct vc_data *vc, unsigned int rows,
149 		    unsigned int cols, int do_clear);
150 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
151 static void save_cur(struct vc_data *vc);
152 static void reset_terminal(struct vc_data *vc, int do_clear);
153 static void con_flush_chars(struct tty_struct *tty);
154 static int set_vesa_blanking(char __user *p);
155 static void set_cursor(struct vc_data *vc);
156 static void hide_cursor(struct vc_data *vc);
157 static void console_callback(struct work_struct *ignored);
158 static void con_driver_unregister_callback(struct work_struct *ignored);
159 static void blank_screen_t(unsigned long dummy);
160 static void set_palette(struct vc_data *vc);
161 
162 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
163 
164 static int printable;		/* Is console ready for printing? */
165 int default_utf8 = true;
166 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
167 int global_cursor_default = -1;
168 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
169 
170 static int cur_default = CUR_DEFAULT;
171 module_param(cur_default, int, S_IRUGO | S_IWUSR);
172 
173 /*
174  * ignore_poke: don't unblank the screen when things are typed.  This is
175  * mainly for the privacy of braille terminal users.
176  */
177 static int ignore_poke;
178 
179 int do_poke_blanked_console;
180 int console_blanked;
181 
182 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
183 static int vesa_off_interval;
184 static int blankinterval = 10*60;
185 core_param(consoleblank, blankinterval, int, 0444);
186 
187 static DECLARE_WORK(console_work, console_callback);
188 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
189 
190 /*
191  * fg_console is the current virtual console,
192  * last_console is the last used one,
193  * want_console is the console we want to switch to,
194  * saved_* variants are for save/restore around kernel debugger enter/leave
195  */
196 int fg_console;
197 int last_console;
198 int want_console = -1;
199 static int saved_fg_console;
200 static int saved_last_console;
201 static int saved_want_console;
202 static int saved_vc_mode;
203 static int saved_console_blanked;
204 
205 /*
206  * For each existing display, we have a pointer to console currently visible
207  * on that display, allowing consoles other than fg_console to be refreshed
208  * appropriately. Unless the low-level driver supplies its own display_fg
209  * variable, we use this one for the "master display".
210  */
211 static struct vc_data *master_display_fg;
212 
213 /*
214  * Unfortunately, we need to delay tty echo when we're currently writing to the
215  * console since the code is (and always was) not re-entrant, so we schedule
216  * all flip requests to process context with schedule-task() and run it from
217  * console_callback().
218  */
219 
220 /*
221  * For the same reason, we defer scrollback to the console callback.
222  */
223 static int scrollback_delta;
224 
225 /*
226  * Hook so that the power management routines can (un)blank
227  * the console on our behalf.
228  */
229 int (*console_blank_hook)(int);
230 
231 static DEFINE_TIMER(console_timer, blank_screen_t, 0, 0);
232 static int blank_state;
233 static int blank_timer_expired;
234 enum {
235 	blank_off = 0,
236 	blank_normal_wait,
237 	blank_vesa_wait,
238 };
239 
240 /*
241  * /sys/class/tty/tty0/
242  *
243  * the attribute 'active' contains the name of the current vc
244  * console and it supports poll() to detect vc switches
245  */
246 static struct device *tty0dev;
247 
248 /*
249  * Notifier list for console events.
250  */
251 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
252 
253 int register_vt_notifier(struct notifier_block *nb)
254 {
255 	return atomic_notifier_chain_register(&vt_notifier_list, nb);
256 }
257 EXPORT_SYMBOL_GPL(register_vt_notifier);
258 
259 int unregister_vt_notifier(struct notifier_block *nb)
260 {
261 	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
262 }
263 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
264 
265 static void notify_write(struct vc_data *vc, unsigned int unicode)
266 {
267 	struct vt_notifier_param param = { .vc = vc, .c = unicode };
268 	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
269 }
270 
271 static void notify_update(struct vc_data *vc)
272 {
273 	struct vt_notifier_param param = { .vc = vc };
274 	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
275 }
276 /*
277  *	Low-Level Functions
278  */
279 
280 static inline bool con_is_fg(const struct vc_data *vc)
281 {
282 	return vc->vc_num == fg_console;
283 }
284 
285 static inline bool con_should_update(const struct vc_data *vc)
286 {
287 	return con_is_visible(vc) && !console_blanked;
288 }
289 
290 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
291 {
292 	unsigned short *p;
293 
294 	if (!viewed)
295 		p = (unsigned short *)(vc->vc_origin + offset);
296 	else if (!vc->vc_sw->con_screen_pos)
297 		p = (unsigned short *)(vc->vc_visible_origin + offset);
298 	else
299 		p = vc->vc_sw->con_screen_pos(vc, offset);
300 	return p;
301 }
302 
303 /* Called  from the keyboard irq path.. */
304 static inline void scrolldelta(int lines)
305 {
306 	/* FIXME */
307 	/* scrolldelta needs some kind of consistency lock, but the BKL was
308 	   and still is not protecting versus the scheduled back end */
309 	scrollback_delta += lines;
310 	schedule_console_callback();
311 }
312 
313 void schedule_console_callback(void)
314 {
315 	schedule_work(&console_work);
316 }
317 
318 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
319 		enum con_scroll dir, unsigned int nr)
320 {
321 	u16 *clear, *d, *s;
322 
323 	if (t + nr >= b)
324 		nr = b - t - 1;
325 	if (b > vc->vc_rows || t >= b || nr < 1)
326 		return;
327 	if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
328 		return;
329 
330 	s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
331 	d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
332 
333 	if (dir == SM_UP) {
334 		clear = s + (b - t - nr) * vc->vc_cols;
335 		swap(s, d);
336 	}
337 	scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
338 	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
339 }
340 
341 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
342 {
343 	unsigned int xx, yy, offset;
344 	u16 *p;
345 
346 	p = (u16 *) start;
347 	if (!vc->vc_sw->con_getxy) {
348 		offset = (start - vc->vc_origin) / 2;
349 		xx = offset % vc->vc_cols;
350 		yy = offset / vc->vc_cols;
351 	} else {
352 		int nxx, nyy;
353 		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
354 		xx = nxx; yy = nyy;
355 	}
356 	for(;;) {
357 		u16 attrib = scr_readw(p) & 0xff00;
358 		int startx = xx;
359 		u16 *q = p;
360 		while (xx < vc->vc_cols && count) {
361 			if (attrib != (scr_readw(p) & 0xff00)) {
362 				if (p > q)
363 					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
364 				startx = xx;
365 				q = p;
366 				attrib = scr_readw(p) & 0xff00;
367 			}
368 			p++;
369 			xx++;
370 			count--;
371 		}
372 		if (p > q)
373 			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
374 		if (!count)
375 			break;
376 		xx = 0;
377 		yy++;
378 		if (vc->vc_sw->con_getxy) {
379 			p = (u16 *)start;
380 			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
381 		}
382 	}
383 }
384 
385 void update_region(struct vc_data *vc, unsigned long start, int count)
386 {
387 	WARN_CONSOLE_UNLOCKED();
388 
389 	if (con_should_update(vc)) {
390 		hide_cursor(vc);
391 		do_update_region(vc, start, count);
392 		set_cursor(vc);
393 	}
394 }
395 
396 /* Structure of attributes is hardware-dependent */
397 
398 static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
399     u8 _underline, u8 _reverse, u8 _italic)
400 {
401 	if (vc->vc_sw->con_build_attr)
402 		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
403 		       _blink, _underline, _reverse, _italic);
404 
405 /*
406  * ++roman: I completely changed the attribute format for monochrome
407  * mode (!can_do_color). The formerly used MDA (monochrome display
408  * adapter) format didn't allow the combination of certain effects.
409  * Now the attribute is just a bit vector:
410  *  Bit 0..1: intensity (0..2)
411  *  Bit 2   : underline
412  *  Bit 3   : reverse
413  *  Bit 7   : blink
414  */
415 	{
416 	u8 a = _color;
417 	if (!vc->vc_can_do_color)
418 		return _intensity |
419 		       (_italic ? 2 : 0) |
420 		       (_underline ? 4 : 0) |
421 		       (_reverse ? 8 : 0) |
422 		       (_blink ? 0x80 : 0);
423 	if (_italic)
424 		a = (a & 0xF0) | vc->vc_itcolor;
425 	else if (_underline)
426 		a = (a & 0xf0) | vc->vc_ulcolor;
427 	else if (_intensity == 0)
428 		a = (a & 0xf0) | vc->vc_ulcolor;
429 	if (_reverse)
430 		a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
431 	if (_blink)
432 		a ^= 0x80;
433 	if (_intensity == 2)
434 		a ^= 0x08;
435 	if (vc->vc_hi_font_mask == 0x100)
436 		a <<= 1;
437 	return a;
438 	}
439 }
440 
441 static void update_attr(struct vc_data *vc)
442 {
443 	vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
444 	              vc->vc_blink, vc->vc_underline,
445 	              vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
446 	vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
447 }
448 
449 /* Note: inverting the screen twice should revert to the original state */
450 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
451 {
452 	unsigned short *p;
453 
454 	WARN_CONSOLE_UNLOCKED();
455 
456 	count /= 2;
457 	p = screenpos(vc, offset, viewed);
458 	if (vc->vc_sw->con_invert_region) {
459 		vc->vc_sw->con_invert_region(vc, p, count);
460 	} else {
461 		u16 *q = p;
462 		int cnt = count;
463 		u16 a;
464 
465 		if (!vc->vc_can_do_color) {
466 			while (cnt--) {
467 			    a = scr_readw(q);
468 			    a ^= 0x0800;
469 			    scr_writew(a, q);
470 			    q++;
471 			}
472 		} else if (vc->vc_hi_font_mask == 0x100) {
473 			while (cnt--) {
474 				a = scr_readw(q);
475 				a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
476 				scr_writew(a, q);
477 				q++;
478 			}
479 		} else {
480 			while (cnt--) {
481 				a = scr_readw(q);
482 				a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
483 				scr_writew(a, q);
484 				q++;
485 			}
486 		}
487 	}
488 
489 	if (con_should_update(vc))
490 		do_update_region(vc, (unsigned long) p, count);
491 	notify_update(vc);
492 }
493 
494 /* used by selection: complement pointer position */
495 void complement_pos(struct vc_data *vc, int offset)
496 {
497 	static int old_offset = -1;
498 	static unsigned short old;
499 	static unsigned short oldx, oldy;
500 
501 	WARN_CONSOLE_UNLOCKED();
502 
503 	if (old_offset != -1 && old_offset >= 0 &&
504 	    old_offset < vc->vc_screenbuf_size) {
505 		scr_writew(old, screenpos(vc, old_offset, 1));
506 		if (con_should_update(vc))
507 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
508 		notify_update(vc);
509 	}
510 
511 	old_offset = offset;
512 
513 	if (offset != -1 && offset >= 0 &&
514 	    offset < vc->vc_screenbuf_size) {
515 		unsigned short new;
516 		unsigned short *p;
517 		p = screenpos(vc, offset, 1);
518 		old = scr_readw(p);
519 		new = old ^ vc->vc_complement_mask;
520 		scr_writew(new, p);
521 		if (con_should_update(vc)) {
522 			oldx = (offset >> 1) % vc->vc_cols;
523 			oldy = (offset >> 1) / vc->vc_cols;
524 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
525 		}
526 		notify_update(vc);
527 	}
528 }
529 
530 static void insert_char(struct vc_data *vc, unsigned int nr)
531 {
532 	unsigned short *p = (unsigned short *) vc->vc_pos;
533 
534 	scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
535 	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
536 	vc->vc_need_wrap = 0;
537 	if (con_should_update(vc))
538 		do_update_region(vc, (unsigned long) p,
539 			vc->vc_cols - vc->vc_x);
540 }
541 
542 static void delete_char(struct vc_data *vc, unsigned int nr)
543 {
544 	unsigned short *p = (unsigned short *) vc->vc_pos;
545 
546 	scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
547 	scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
548 			nr * 2);
549 	vc->vc_need_wrap = 0;
550 	if (con_should_update(vc))
551 		do_update_region(vc, (unsigned long) p,
552 			vc->vc_cols - vc->vc_x);
553 }
554 
555 static int softcursor_original = -1;
556 
557 static void add_softcursor(struct vc_data *vc)
558 {
559 	int i = scr_readw((u16 *) vc->vc_pos);
560 	u32 type = vc->vc_cursor_type;
561 
562 	if (! (type & 0x10)) return;
563 	if (softcursor_original != -1) return;
564 	softcursor_original = i;
565 	i |= ((type >> 8) & 0xff00 );
566 	i ^= ((type) & 0xff00 );
567 	if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
568 	if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
569 	scr_writew(i, (u16 *) vc->vc_pos);
570 	if (con_should_update(vc))
571 		vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
572 }
573 
574 static void hide_softcursor(struct vc_data *vc)
575 {
576 	if (softcursor_original != -1) {
577 		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
578 		if (con_should_update(vc))
579 			vc->vc_sw->con_putc(vc, softcursor_original,
580 					vc->vc_y, vc->vc_x);
581 		softcursor_original = -1;
582 	}
583 }
584 
585 static void hide_cursor(struct vc_data *vc)
586 {
587 	if (vc == sel_cons)
588 		clear_selection();
589 	vc->vc_sw->con_cursor(vc, CM_ERASE);
590 	hide_softcursor(vc);
591 }
592 
593 static void set_cursor(struct vc_data *vc)
594 {
595 	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
596 		return;
597 	if (vc->vc_deccm) {
598 		if (vc == sel_cons)
599 			clear_selection();
600 		add_softcursor(vc);
601 		if ((vc->vc_cursor_type & 0x0f) != 1)
602 			vc->vc_sw->con_cursor(vc, CM_DRAW);
603 	} else
604 		hide_cursor(vc);
605 }
606 
607 static void set_origin(struct vc_data *vc)
608 {
609 	WARN_CONSOLE_UNLOCKED();
610 
611 	if (!con_is_visible(vc) ||
612 	    !vc->vc_sw->con_set_origin ||
613 	    !vc->vc_sw->con_set_origin(vc))
614 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
615 	vc->vc_visible_origin = vc->vc_origin;
616 	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
617 	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
618 }
619 
620 static void save_screen(struct vc_data *vc)
621 {
622 	WARN_CONSOLE_UNLOCKED();
623 
624 	if (vc->vc_sw->con_save_screen)
625 		vc->vc_sw->con_save_screen(vc);
626 }
627 
628 static void flush_scrollback(struct vc_data *vc)
629 {
630 	WARN_CONSOLE_UNLOCKED();
631 
632 	if (vc->vc_sw->con_flush_scrollback)
633 		vc->vc_sw->con_flush_scrollback(vc);
634 }
635 
636 /*
637  *	Redrawing of screen
638  */
639 
640 void clear_buffer_attributes(struct vc_data *vc)
641 {
642 	unsigned short *p = (unsigned short *)vc->vc_origin;
643 	int count = vc->vc_screenbuf_size / 2;
644 	int mask = vc->vc_hi_font_mask | 0xff;
645 
646 	for (; count > 0; count--, p++) {
647 		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
648 	}
649 }
650 
651 void redraw_screen(struct vc_data *vc, int is_switch)
652 {
653 	int redraw = 0;
654 
655 	WARN_CONSOLE_UNLOCKED();
656 
657 	if (!vc) {
658 		/* strange ... */
659 		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
660 		return;
661 	}
662 
663 	if (is_switch) {
664 		struct vc_data *old_vc = vc_cons[fg_console].d;
665 		if (old_vc == vc)
666 			return;
667 		if (!con_is_visible(vc))
668 			redraw = 1;
669 		*vc->vc_display_fg = vc;
670 		fg_console = vc->vc_num;
671 		hide_cursor(old_vc);
672 		if (!con_is_visible(old_vc)) {
673 			save_screen(old_vc);
674 			set_origin(old_vc);
675 		}
676 		if (tty0dev)
677 			sysfs_notify(&tty0dev->kobj, NULL, "active");
678 	} else {
679 		hide_cursor(vc);
680 		redraw = 1;
681 	}
682 
683 	if (redraw) {
684 		int update;
685 		int old_was_color = vc->vc_can_do_color;
686 
687 		set_origin(vc);
688 		update = vc->vc_sw->con_switch(vc);
689 		set_palette(vc);
690 		/*
691 		 * If console changed from mono<->color, the best we can do
692 		 * is to clear the buffer attributes. As it currently stands,
693 		 * rebuilding new attributes from the old buffer is not doable
694 		 * without overly complex code.
695 		 */
696 		if (old_was_color != vc->vc_can_do_color) {
697 			update_attr(vc);
698 			clear_buffer_attributes(vc);
699 		}
700 
701 		/* Forcibly update if we're panicing */
702 		if ((update && vc->vc_mode != KD_GRAPHICS) ||
703 		    vt_force_oops_output(vc))
704 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
705 	}
706 	set_cursor(vc);
707 	if (is_switch) {
708 		set_leds();
709 		compute_shiftstate();
710 		notify_update(vc);
711 	}
712 }
713 
714 /*
715  *	Allocation, freeing and resizing of VTs.
716  */
717 
718 int vc_cons_allocated(unsigned int i)
719 {
720 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
721 }
722 
723 static void visual_init(struct vc_data *vc, int num, int init)
724 {
725 	/* ++Geert: vc->vc_sw->con_init determines console size */
726 	if (vc->vc_sw)
727 		module_put(vc->vc_sw->owner);
728 	vc->vc_sw = conswitchp;
729 #ifndef VT_SINGLE_DRIVER
730 	if (con_driver_map[num])
731 		vc->vc_sw = con_driver_map[num];
732 #endif
733 	__module_get(vc->vc_sw->owner);
734 	vc->vc_num = num;
735 	vc->vc_display_fg = &master_display_fg;
736 	if (vc->vc_uni_pagedir_loc)
737 		con_free_unimap(vc);
738 	vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
739 	vc->vc_uni_pagedir = NULL;
740 	vc->vc_hi_font_mask = 0;
741 	vc->vc_complement_mask = 0;
742 	vc->vc_can_do_color = 0;
743 	vc->vc_panic_force_write = false;
744 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
745 	vc->vc_sw->con_init(vc, init);
746 	if (!vc->vc_complement_mask)
747 		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
748 	vc->vc_s_complement_mask = vc->vc_complement_mask;
749 	vc->vc_size_row = vc->vc_cols << 1;
750 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
751 }
752 
753 int vc_allocate(unsigned int currcons)	/* return 0 on success */
754 {
755 	struct vt_notifier_param param;
756 	struct vc_data *vc;
757 
758 	WARN_CONSOLE_UNLOCKED();
759 
760 	if (currcons >= MAX_NR_CONSOLES)
761 		return -ENXIO;
762 
763 	if (vc_cons[currcons].d)
764 		return 0;
765 
766 	/* due to the granularity of kmalloc, we waste some memory here */
767 	/* the alloc is done in two steps, to optimize the common situation
768 	   of a 25x80 console (structsize=216, screenbuf_size=4000) */
769 	/* although the numbers above are not valid since long ago, the
770 	   point is still up-to-date and the comment still has its value
771 	   even if only as a historical artifact.  --mj, July 1998 */
772 	param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
773 	if (!vc)
774 		return -ENOMEM;
775 
776 	vc_cons[currcons].d = vc;
777 	tty_port_init(&vc->port);
778 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
779 
780 	visual_init(vc, currcons, 1);
781 
782 	if (!*vc->vc_uni_pagedir_loc)
783 		con_set_default_unimap(vc);
784 
785 	vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
786 	if (!vc->vc_screenbuf)
787 		goto err_free;
788 
789 	/* If no drivers have overridden us and the user didn't pass a
790 	   boot option, default to displaying the cursor */
791 	if (global_cursor_default == -1)
792 		global_cursor_default = 1;
793 
794 	vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
795 	vcs_make_sysfs(currcons);
796 	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
797 
798 	return 0;
799 err_free:
800 	kfree(vc);
801 	vc_cons[currcons].d = NULL;
802 	return -ENOMEM;
803 }
804 
805 static inline int resize_screen(struct vc_data *vc, int width, int height,
806 				int user)
807 {
808 	/* Resizes the resolution of the display adapater */
809 	int err = 0;
810 
811 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
812 		err = vc->vc_sw->con_resize(vc, width, height, user);
813 
814 	return err;
815 }
816 
817 /*
818  * Change # of rows and columns (0 means unchanged/the size of fg_console)
819  * [this is to be used together with some user program
820  * like resize that changes the hardware videomode]
821  */
822 #define VC_RESIZE_MAXCOL (32767)
823 #define VC_RESIZE_MAXROW (32767)
824 
825 /**
826  *	vc_do_resize	-	resizing method for the tty
827  *	@tty: tty being resized
828  *	@real_tty: real tty (different to tty if a pty/tty pair)
829  *	@vc: virtual console private data
830  *	@cols: columns
831  *	@lines: lines
832  *
833  *	Resize a virtual console, clipping according to the actual constraints.
834  *	If the caller passes a tty structure then update the termios winsize
835  *	information and perform any necessary signal handling.
836  *
837  *	Caller must hold the console semaphore. Takes the termios rwsem and
838  *	ctrl_lock of the tty IFF a tty is passed.
839  */
840 
841 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
842 				unsigned int cols, unsigned int lines)
843 {
844 	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
845 	unsigned long end;
846 	unsigned int old_rows, old_row_size;
847 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
848 	unsigned int user;
849 	unsigned short *newscreen;
850 
851 	WARN_CONSOLE_UNLOCKED();
852 
853 	if (!vc)
854 		return -ENXIO;
855 
856 	user = vc->vc_resize_user;
857 	vc->vc_resize_user = 0;
858 
859 	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
860 		return -EINVAL;
861 
862 	new_cols = (cols ? cols : vc->vc_cols);
863 	new_rows = (lines ? lines : vc->vc_rows);
864 	new_row_size = new_cols << 1;
865 	new_screen_size = new_row_size * new_rows;
866 
867 	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
868 		return 0;
869 
870 	if (new_screen_size > (4 << 20))
871 		return -EINVAL;
872 	newscreen = kmalloc(new_screen_size, GFP_USER);
873 	if (!newscreen)
874 		return -ENOMEM;
875 
876 	if (vc == sel_cons)
877 		clear_selection();
878 
879 	old_rows = vc->vc_rows;
880 	old_row_size = vc->vc_size_row;
881 
882 	err = resize_screen(vc, new_cols, new_rows, user);
883 	if (err) {
884 		kfree(newscreen);
885 		return err;
886 	}
887 
888 	vc->vc_rows = new_rows;
889 	vc->vc_cols = new_cols;
890 	vc->vc_size_row = new_row_size;
891 	vc->vc_screenbuf_size = new_screen_size;
892 
893 	rlth = min(old_row_size, new_row_size);
894 	rrem = new_row_size - rlth;
895 	old_origin = vc->vc_origin;
896 	new_origin = (long) newscreen;
897 	new_scr_end = new_origin + new_screen_size;
898 
899 	if (vc->vc_y > new_rows) {
900 		if (old_rows - vc->vc_y < new_rows) {
901 			/*
902 			 * Cursor near the bottom, copy contents from the
903 			 * bottom of buffer
904 			 */
905 			old_origin += (old_rows - new_rows) * old_row_size;
906 		} else {
907 			/*
908 			 * Cursor is in no man's land, copy 1/2 screenful
909 			 * from the top and bottom of cursor position
910 			 */
911 			old_origin += (vc->vc_y - new_rows/2) * old_row_size;
912 		}
913 	}
914 
915 	end = old_origin + old_row_size * min(old_rows, new_rows);
916 
917 	update_attr(vc);
918 
919 	while (old_origin < end) {
920 		scr_memcpyw((unsigned short *) new_origin,
921 			    (unsigned short *) old_origin, rlth);
922 		if (rrem)
923 			scr_memsetw((void *)(new_origin + rlth),
924 				    vc->vc_video_erase_char, rrem);
925 		old_origin += old_row_size;
926 		new_origin += new_row_size;
927 	}
928 	if (new_scr_end > new_origin)
929 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
930 			    new_scr_end - new_origin);
931 	kfree(vc->vc_screenbuf);
932 	vc->vc_screenbuf = newscreen;
933 	vc->vc_screenbuf_size = new_screen_size;
934 	set_origin(vc);
935 
936 	/* do part of a reset_terminal() */
937 	vc->vc_top = 0;
938 	vc->vc_bottom = vc->vc_rows;
939 	gotoxy(vc, vc->vc_x, vc->vc_y);
940 	save_cur(vc);
941 
942 	if (tty) {
943 		/* Rewrite the requested winsize data with the actual
944 		   resulting sizes */
945 		struct winsize ws;
946 		memset(&ws, 0, sizeof(ws));
947 		ws.ws_row = vc->vc_rows;
948 		ws.ws_col = vc->vc_cols;
949 		ws.ws_ypixel = vc->vc_scan_lines;
950 		tty_do_resize(tty, &ws);
951 	}
952 
953 	if (con_is_visible(vc))
954 		update_screen(vc);
955 	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
956 	return err;
957 }
958 
959 /**
960  *	vc_resize		-	resize a VT
961  *	@vc: virtual console
962  *	@cols: columns
963  *	@rows: rows
964  *
965  *	Resize a virtual console as seen from the console end of things. We
966  *	use the common vc_do_resize methods to update the structures. The
967  *	caller must hold the console sem to protect console internals and
968  *	vc->port.tty
969  */
970 
971 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
972 {
973 	return vc_do_resize(vc->port.tty, vc, cols, rows);
974 }
975 
976 /**
977  *	vt_resize		-	resize a VT
978  *	@tty: tty to resize
979  *	@ws: winsize attributes
980  *
981  *	Resize a virtual terminal. This is called by the tty layer as we
982  *	register our own handler for resizing. The mutual helper does all
983  *	the actual work.
984  *
985  *	Takes the console sem and the called methods then take the tty
986  *	termios_rwsem and the tty ctrl_lock in that order.
987  */
988 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
989 {
990 	struct vc_data *vc = tty->driver_data;
991 	int ret;
992 
993 	console_lock();
994 	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
995 	console_unlock();
996 	return ret;
997 }
998 
999 struct vc_data *vc_deallocate(unsigned int currcons)
1000 {
1001 	struct vc_data *vc = NULL;
1002 
1003 	WARN_CONSOLE_UNLOCKED();
1004 
1005 	if (vc_cons_allocated(currcons)) {
1006 		struct vt_notifier_param param;
1007 
1008 		param.vc = vc = vc_cons[currcons].d;
1009 		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1010 		vcs_remove_sysfs(currcons);
1011 		vc->vc_sw->con_deinit(vc);
1012 		put_pid(vc->vt_pid);
1013 		module_put(vc->vc_sw->owner);
1014 		kfree(vc->vc_screenbuf);
1015 		vc_cons[currcons].d = NULL;
1016 	}
1017 	return vc;
1018 }
1019 
1020 /*
1021  *	VT102 emulator
1022  */
1023 
1024 #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
1025 #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1026 #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (x))
1027 
1028 #define decarm		VC_REPEAT
1029 #define decckm		VC_CKMODE
1030 #define kbdapplic	VC_APPLIC
1031 #define lnm		VC_CRLF
1032 
1033 /*
1034  * this is what the terminal answers to a ESC-Z or csi0c query.
1035  */
1036 #define VT100ID "\033[?1;2c"
1037 #define VT102ID "\033[?6c"
1038 
1039 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1040 				       8,12,10,14, 9,13,11,15 };
1041 
1042 /* the default colour table, for VGA+ colour systems */
1043 unsigned char default_red[] = {
1044 	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1045 	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1046 };
1047 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1048 
1049 unsigned char default_grn[] = {
1050 	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1051 	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1052 };
1053 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1054 
1055 unsigned char default_blu[] = {
1056 	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1057 	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1058 };
1059 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1060 
1061 /*
1062  * gotoxy() must verify all boundaries, because the arguments
1063  * might also be negative. If the given position is out of
1064  * bounds, the cursor is placed at the nearest margin.
1065  */
1066 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1067 {
1068 	int min_y, max_y;
1069 
1070 	if (new_x < 0)
1071 		vc->vc_x = 0;
1072 	else {
1073 		if (new_x >= vc->vc_cols)
1074 			vc->vc_x = vc->vc_cols - 1;
1075 		else
1076 			vc->vc_x = new_x;
1077 	}
1078 
1079  	if (vc->vc_decom) {
1080 		min_y = vc->vc_top;
1081 		max_y = vc->vc_bottom;
1082 	} else {
1083 		min_y = 0;
1084 		max_y = vc->vc_rows;
1085 	}
1086 	if (new_y < min_y)
1087 		vc->vc_y = min_y;
1088 	else if (new_y >= max_y)
1089 		vc->vc_y = max_y - 1;
1090 	else
1091 		vc->vc_y = new_y;
1092 	vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
1093 	vc->vc_need_wrap = 0;
1094 }
1095 
1096 /* for absolute user moves, when decom is set */
1097 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1098 {
1099 	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1100 }
1101 
1102 void scrollback(struct vc_data *vc)
1103 {
1104 	scrolldelta(-(vc->vc_rows / 2));
1105 }
1106 
1107 void scrollfront(struct vc_data *vc, int lines)
1108 {
1109 	if (!lines)
1110 		lines = vc->vc_rows / 2;
1111 	scrolldelta(lines);
1112 }
1113 
1114 static void lf(struct vc_data *vc)
1115 {
1116     	/* don't scroll if above bottom of scrolling region, or
1117 	 * if below scrolling region
1118 	 */
1119     	if (vc->vc_y + 1 == vc->vc_bottom)
1120 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1121 	else if (vc->vc_y < vc->vc_rows - 1) {
1122 	    	vc->vc_y++;
1123 		vc->vc_pos += vc->vc_size_row;
1124 	}
1125 	vc->vc_need_wrap = 0;
1126 	notify_write(vc, '\n');
1127 }
1128 
1129 static void ri(struct vc_data *vc)
1130 {
1131     	/* don't scroll if below top of scrolling region, or
1132 	 * if above scrolling region
1133 	 */
1134 	if (vc->vc_y == vc->vc_top)
1135 		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1136 	else if (vc->vc_y > 0) {
1137 		vc->vc_y--;
1138 		vc->vc_pos -= vc->vc_size_row;
1139 	}
1140 	vc->vc_need_wrap = 0;
1141 }
1142 
1143 static inline void cr(struct vc_data *vc)
1144 {
1145 	vc->vc_pos -= vc->vc_x << 1;
1146 	vc->vc_need_wrap = vc->vc_x = 0;
1147 	notify_write(vc, '\r');
1148 }
1149 
1150 static inline void bs(struct vc_data *vc)
1151 {
1152 	if (vc->vc_x) {
1153 		vc->vc_pos -= 2;
1154 		vc->vc_x--;
1155 		vc->vc_need_wrap = 0;
1156 		notify_write(vc, '\b');
1157 	}
1158 }
1159 
1160 static inline void del(struct vc_data *vc)
1161 {
1162 	/* ignored */
1163 }
1164 
1165 static void csi_J(struct vc_data *vc, int vpar)
1166 {
1167 	unsigned int count;
1168 	unsigned short * start;
1169 
1170 	switch (vpar) {
1171 		case 0:	/* erase from cursor to end of display */
1172 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1173 			start = (unsigned short *)vc->vc_pos;
1174 			break;
1175 		case 1:	/* erase from start to cursor */
1176 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1177 			start = (unsigned short *)vc->vc_origin;
1178 			break;
1179 		case 3: /* erase scroll-back buffer (and whole display) */
1180 			scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
1181 				    vc->vc_screenbuf_size);
1182 			flush_scrollback(vc);
1183 			set_origin(vc);
1184 			if (con_is_visible(vc))
1185 				update_screen(vc);
1186 			/* fall through */
1187 		case 2: /* erase whole display */
1188 			count = vc->vc_cols * vc->vc_rows;
1189 			start = (unsigned short *)vc->vc_origin;
1190 			break;
1191 		default:
1192 			return;
1193 	}
1194 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1195 	if (con_should_update(vc))
1196 		do_update_region(vc, (unsigned long) start, count);
1197 	vc->vc_need_wrap = 0;
1198 }
1199 
1200 static void csi_K(struct vc_data *vc, int vpar)
1201 {
1202 	unsigned int count;
1203 	unsigned short * start;
1204 
1205 	switch (vpar) {
1206 		case 0:	/* erase from cursor to end of line */
1207 			count = vc->vc_cols - vc->vc_x;
1208 			start = (unsigned short *)vc->vc_pos;
1209 			break;
1210 		case 1:	/* erase from start of line to cursor */
1211 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1212 			count = vc->vc_x + 1;
1213 			break;
1214 		case 2: /* erase whole line */
1215 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
1216 			count = vc->vc_cols;
1217 			break;
1218 		default:
1219 			return;
1220 	}
1221 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1222 	vc->vc_need_wrap = 0;
1223 	if (con_should_update(vc))
1224 		do_update_region(vc, (unsigned long) start, count);
1225 }
1226 
1227 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1228 {					  /* not vt100? */
1229 	int count;
1230 
1231 	if (!vpar)
1232 		vpar++;
1233 	count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
1234 
1235 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1236 	if (con_should_update(vc))
1237 		vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
1238 	vc->vc_need_wrap = 0;
1239 }
1240 
1241 static void default_attr(struct vc_data *vc)
1242 {
1243 	vc->vc_intensity = 1;
1244 	vc->vc_italic = 0;
1245 	vc->vc_underline = 0;
1246 	vc->vc_reverse = 0;
1247 	vc->vc_blink = 0;
1248 	vc->vc_color = vc->vc_def_color;
1249 }
1250 
1251 struct rgb { u8 r; u8 g; u8 b; };
1252 
1253 static void rgb_from_256(int i, struct rgb *c)
1254 {
1255 	if (i < 8) {            /* Standard colours. */
1256 		c->r = i&1 ? 0xaa : 0x00;
1257 		c->g = i&2 ? 0xaa : 0x00;
1258 		c->b = i&4 ? 0xaa : 0x00;
1259 	} else if (i < 16) {
1260 		c->r = i&1 ? 0xff : 0x55;
1261 		c->g = i&2 ? 0xff : 0x55;
1262 		c->b = i&4 ? 0xff : 0x55;
1263 	} else if (i < 232) {   /* 6x6x6 colour cube. */
1264 		c->r = (i - 16) / 36 * 85 / 2;
1265 		c->g = (i - 16) / 6 % 6 * 85 / 2;
1266 		c->b = (i - 16) % 6 * 85 / 2;
1267 	} else                  /* Grayscale ramp. */
1268 		c->r = c->g = c->b = i * 10 - 2312;
1269 }
1270 
1271 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1272 {
1273 	u8 hue = 0, max = max3(c->r, c->g, c->b);
1274 
1275 	if (c->r > max / 2)
1276 		hue |= 4;
1277 	if (c->g > max / 2)
1278 		hue |= 2;
1279 	if (c->b > max / 2)
1280 		hue |= 1;
1281 
1282 	if (hue == 7 && max <= 0x55) {
1283 		hue = 0;
1284 		vc->vc_intensity = 2;
1285 	} else if (max > 0xaa)
1286 		vc->vc_intensity = 2;
1287 	else
1288 		vc->vc_intensity = 1;
1289 
1290 	vc->vc_color = (vc->vc_color & 0xf0) | hue;
1291 }
1292 
1293 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1294 {
1295 	/* For backgrounds, err on the dark side. */
1296 	vc->vc_color = (vc->vc_color & 0x0f)
1297 		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1298 }
1299 
1300 /*
1301  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1302  * and thus need to be detected and ignored by hand. Strictly speaking, that
1303  * standard also wants : rather than ; as separators, contrary to ECMA-48, but
1304  * no one produces such codes and almost no one accepts them.
1305  *
1306  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1307  * supporting them.
1308  */
1309 static int vc_t416_color(struct vc_data *vc, int i,
1310 		void(*set_color)(struct vc_data *vc, const struct rgb *c))
1311 {
1312 	struct rgb c;
1313 
1314 	i++;
1315 	if (i > vc->vc_npar)
1316 		return i;
1317 
1318 	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1319 		/* 256 colours */
1320 		i++;
1321 		rgb_from_256(vc->vc_par[i], &c);
1322 	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1323 		/* 24 bit */
1324 		c.r = vc->vc_par[i + 1];
1325 		c.g = vc->vc_par[i + 2];
1326 		c.b = vc->vc_par[i + 3];
1327 		i += 3;
1328 	} else
1329 		return i;
1330 
1331 	set_color(vc, &c);
1332 
1333 	return i;
1334 }
1335 
1336 /* console_lock is held */
1337 static void csi_m(struct vc_data *vc)
1338 {
1339 	int i;
1340 
1341 	for (i = 0; i <= vc->vc_npar; i++)
1342 		switch (vc->vc_par[i]) {
1343 		case 0:	/* all attributes off */
1344 			default_attr(vc);
1345 			break;
1346 		case 1:
1347 			vc->vc_intensity = 2;
1348 			break;
1349 		case 2:
1350 			vc->vc_intensity = 0;
1351 			break;
1352 		case 3:
1353 			vc->vc_italic = 1;
1354 			break;
1355 		case 4:
1356 			vc->vc_underline = 1;
1357 			break;
1358 		case 5:
1359 			vc->vc_blink = 1;
1360 			break;
1361 		case 7:
1362 			vc->vc_reverse = 1;
1363 			break;
1364 		case 10: /* ANSI X3.64-1979 (SCO-ish?)
1365 			  * Select primary font, don't display control chars if
1366 			  * defined, don't set bit 8 on output.
1367 			  */
1368 			vc->vc_translate = set_translate(vc->vc_charset == 0
1369 					? vc->vc_G0_charset
1370 					: vc->vc_G1_charset, vc);
1371 			vc->vc_disp_ctrl = 0;
1372 			vc->vc_toggle_meta = 0;
1373 			break;
1374 		case 11: /* ANSI X3.64-1979 (SCO-ish?)
1375 			  * Select first alternate font, lets chars < 32 be
1376 			  * displayed as ROM chars.
1377 			  */
1378 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1379 			vc->vc_disp_ctrl = 1;
1380 			vc->vc_toggle_meta = 0;
1381 			break;
1382 		case 12: /* ANSI X3.64-1979 (SCO-ish?)
1383 			  * Select second alternate font, toggle high bit
1384 			  * before displaying as ROM char.
1385 			  */
1386 			vc->vc_translate = set_translate(IBMPC_MAP, vc);
1387 			vc->vc_disp_ctrl = 1;
1388 			vc->vc_toggle_meta = 1;
1389 			break;
1390 		case 21:
1391 		case 22:
1392 			vc->vc_intensity = 1;
1393 			break;
1394 		case 23:
1395 			vc->vc_italic = 0;
1396 			break;
1397 		case 24:
1398 			vc->vc_underline = 0;
1399 			break;
1400 		case 25:
1401 			vc->vc_blink = 0;
1402 			break;
1403 		case 27:
1404 			vc->vc_reverse = 0;
1405 			break;
1406 		case 38:
1407 			i = vc_t416_color(vc, i, rgb_foreground);
1408 			break;
1409 		case 48:
1410 			i = vc_t416_color(vc, i, rgb_background);
1411 			break;
1412 		case 39:
1413 			vc->vc_color = (vc->vc_def_color & 0x0f) |
1414 				(vc->vc_color & 0xf0);
1415 			break;
1416 		case 49:
1417 			vc->vc_color = (vc->vc_def_color & 0xf0) |
1418 				(vc->vc_color & 0x0f);
1419 			break;
1420 		default:
1421 			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1422 				if (vc->vc_par[i] < 100)
1423 					vc->vc_intensity = 2;
1424 				vc->vc_par[i] -= 60;
1425 			}
1426 			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1427 				vc->vc_color = color_table[vc->vc_par[i] - 30]
1428 					| (vc->vc_color & 0xf0);
1429 			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1430 				vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1431 					| (vc->vc_color & 0x0f);
1432 			break;
1433 		}
1434 	update_attr(vc);
1435 }
1436 
1437 static void respond_string(const char *p, struct tty_port *port)
1438 {
1439 	while (*p) {
1440 		tty_insert_flip_char(port, *p, 0);
1441 		p++;
1442 	}
1443 	tty_schedule_flip(port);
1444 }
1445 
1446 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1447 {
1448 	char buf[40];
1449 
1450 	sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1451 	respond_string(buf, tty->port);
1452 }
1453 
1454 static inline void status_report(struct tty_struct *tty)
1455 {
1456 	respond_string("\033[0n", tty->port);	/* Terminal ok */
1457 }
1458 
1459 static inline void respond_ID(struct tty_struct *tty)
1460 {
1461 	respond_string(VT102ID, tty->port);
1462 }
1463 
1464 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1465 {
1466 	char buf[8];
1467 
1468 	sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1469 		(char)('!' + mry));
1470 	respond_string(buf, tty->port);
1471 }
1472 
1473 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1474 int mouse_reporting(void)
1475 {
1476 	return vc_cons[fg_console].d->vc_report_mouse;
1477 }
1478 
1479 /* console_lock is held */
1480 static void set_mode(struct vc_data *vc, int on_off)
1481 {
1482 	int i;
1483 
1484 	for (i = 0; i <= vc->vc_npar; i++)
1485 		if (vc->vc_ques) {
1486 			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
1487 			case 1:			/* Cursor keys send ^[Ox/^[[x */
1488 				if (on_off)
1489 					set_kbd(vc, decckm);
1490 				else
1491 					clr_kbd(vc, decckm);
1492 				break;
1493 			case 3:	/* 80/132 mode switch unimplemented */
1494 #if 0
1495 				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1496 				/* this alone does not suffice; some user mode
1497 				   utility has to change the hardware regs */
1498 #endif
1499 				break;
1500 			case 5:			/* Inverted screen on/off */
1501 				if (vc->vc_decscnm != on_off) {
1502 					vc->vc_decscnm = on_off;
1503 					invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1504 					update_attr(vc);
1505 				}
1506 				break;
1507 			case 6:			/* Origin relative/absolute */
1508 				vc->vc_decom = on_off;
1509 				gotoxay(vc, 0, 0);
1510 				break;
1511 			case 7:			/* Autowrap on/off */
1512 				vc->vc_decawm = on_off;
1513 				break;
1514 			case 8:			/* Autorepeat on/off */
1515 				if (on_off)
1516 					set_kbd(vc, decarm);
1517 				else
1518 					clr_kbd(vc, decarm);
1519 				break;
1520 			case 9:
1521 				vc->vc_report_mouse = on_off ? 1 : 0;
1522 				break;
1523 			case 25:		/* Cursor on/off */
1524 				vc->vc_deccm = on_off;
1525 				break;
1526 			case 1000:
1527 				vc->vc_report_mouse = on_off ? 2 : 0;
1528 				break;
1529 			}
1530 		} else {
1531 			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
1532 			case 3:			/* Monitor (display ctrls) */
1533 				vc->vc_disp_ctrl = on_off;
1534 				break;
1535 			case 4:			/* Insert Mode on/off */
1536 				vc->vc_decim = on_off;
1537 				break;
1538 			case 20:		/* Lf, Enter == CrLf/Lf */
1539 				if (on_off)
1540 					set_kbd(vc, lnm);
1541 				else
1542 					clr_kbd(vc, lnm);
1543 				break;
1544 			}
1545 		}
1546 }
1547 
1548 /* console_lock is held */
1549 static void setterm_command(struct vc_data *vc)
1550 {
1551 	switch(vc->vc_par[0]) {
1552 		case 1:	/* set color for underline mode */
1553 			if (vc->vc_can_do_color &&
1554 					vc->vc_par[1] < 16) {
1555 				vc->vc_ulcolor = color_table[vc->vc_par[1]];
1556 				if (vc->vc_underline)
1557 					update_attr(vc);
1558 			}
1559 			break;
1560 		case 2:	/* set color for half intensity mode */
1561 			if (vc->vc_can_do_color &&
1562 					vc->vc_par[1] < 16) {
1563 				vc->vc_halfcolor = color_table[vc->vc_par[1]];
1564 				if (vc->vc_intensity == 0)
1565 					update_attr(vc);
1566 			}
1567 			break;
1568 		case 8:	/* store colors as defaults */
1569 			vc->vc_def_color = vc->vc_attr;
1570 			if (vc->vc_hi_font_mask == 0x100)
1571 				vc->vc_def_color >>= 1;
1572 			default_attr(vc);
1573 			update_attr(vc);
1574 			break;
1575 		case 9:	/* set blanking interval */
1576 			blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1577 			poke_blanked_console();
1578 			break;
1579 		case 10: /* set bell frequency in Hz */
1580 			if (vc->vc_npar >= 1)
1581 				vc->vc_bell_pitch = vc->vc_par[1];
1582 			else
1583 				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1584 			break;
1585 		case 11: /* set bell duration in msec */
1586 			if (vc->vc_npar >= 1)
1587 				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1588 					msecs_to_jiffies(vc->vc_par[1]) : 0;
1589 			else
1590 				vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1591 			break;
1592 		case 12: /* bring specified console to the front */
1593 			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1594 				set_console(vc->vc_par[1] - 1);
1595 			break;
1596 		case 13: /* unblank the screen */
1597 			poke_blanked_console();
1598 			break;
1599 		case 14: /* set vesa powerdown interval */
1600 			vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1601 			break;
1602 		case 15: /* activate the previous console */
1603 			set_console(last_console);
1604 			break;
1605 		case 16: /* set cursor blink duration in msec */
1606 			if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1607 					vc->vc_par[1] <= USHRT_MAX)
1608 				vc->vc_cur_blink_ms = vc->vc_par[1];
1609 			else
1610 				vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1611 			break;
1612 	}
1613 }
1614 
1615 /* console_lock is held */
1616 static void csi_at(struct vc_data *vc, unsigned int nr)
1617 {
1618 	if (nr > vc->vc_cols - vc->vc_x)
1619 		nr = vc->vc_cols - vc->vc_x;
1620 	else if (!nr)
1621 		nr = 1;
1622 	insert_char(vc, nr);
1623 }
1624 
1625 /* console_lock is held */
1626 static void csi_L(struct vc_data *vc, unsigned int nr)
1627 {
1628 	if (nr > vc->vc_rows - vc->vc_y)
1629 		nr = vc->vc_rows - vc->vc_y;
1630 	else if (!nr)
1631 		nr = 1;
1632 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_DOWN, nr);
1633 	vc->vc_need_wrap = 0;
1634 }
1635 
1636 /* console_lock is held */
1637 static void csi_P(struct vc_data *vc, unsigned int nr)
1638 {
1639 	if (nr > vc->vc_cols - vc->vc_x)
1640 		nr = vc->vc_cols - vc->vc_x;
1641 	else if (!nr)
1642 		nr = 1;
1643 	delete_char(vc, nr);
1644 }
1645 
1646 /* console_lock is held */
1647 static void csi_M(struct vc_data *vc, unsigned int nr)
1648 {
1649 	if (nr > vc->vc_rows - vc->vc_y)
1650 		nr = vc->vc_rows - vc->vc_y;
1651 	else if (!nr)
1652 		nr=1;
1653 	con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_UP, nr);
1654 	vc->vc_need_wrap = 0;
1655 }
1656 
1657 /* console_lock is held (except via vc_init->reset_terminal */
1658 static void save_cur(struct vc_data *vc)
1659 {
1660 	vc->vc_saved_x		= vc->vc_x;
1661 	vc->vc_saved_y		= vc->vc_y;
1662 	vc->vc_s_intensity	= vc->vc_intensity;
1663 	vc->vc_s_italic         = vc->vc_italic;
1664 	vc->vc_s_underline	= vc->vc_underline;
1665 	vc->vc_s_blink		= vc->vc_blink;
1666 	vc->vc_s_reverse	= vc->vc_reverse;
1667 	vc->vc_s_charset	= vc->vc_charset;
1668 	vc->vc_s_color		= vc->vc_color;
1669 	vc->vc_saved_G0		= vc->vc_G0_charset;
1670 	vc->vc_saved_G1		= vc->vc_G1_charset;
1671 }
1672 
1673 /* console_lock is held */
1674 static void restore_cur(struct vc_data *vc)
1675 {
1676 	gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
1677 	vc->vc_intensity	= vc->vc_s_intensity;
1678 	vc->vc_italic		= vc->vc_s_italic;
1679 	vc->vc_underline	= vc->vc_s_underline;
1680 	vc->vc_blink		= vc->vc_s_blink;
1681 	vc->vc_reverse		= vc->vc_s_reverse;
1682 	vc->vc_charset		= vc->vc_s_charset;
1683 	vc->vc_color		= vc->vc_s_color;
1684 	vc->vc_G0_charset	= vc->vc_saved_G0;
1685 	vc->vc_G1_charset	= vc->vc_saved_G1;
1686 	vc->vc_translate	= set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
1687 	update_attr(vc);
1688 	vc->vc_need_wrap = 0;
1689 }
1690 
1691 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
1692 	EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
1693 	ESpalette, ESosc };
1694 
1695 /* console_lock is held (except via vc_init()) */
1696 static void reset_terminal(struct vc_data *vc, int do_clear)
1697 {
1698 	vc->vc_top		= 0;
1699 	vc->vc_bottom		= vc->vc_rows;
1700 	vc->vc_state		= ESnormal;
1701 	vc->vc_ques		= 0;
1702 	vc->vc_translate	= set_translate(LAT1_MAP, vc);
1703 	vc->vc_G0_charset	= LAT1_MAP;
1704 	vc->vc_G1_charset	= GRAF_MAP;
1705 	vc->vc_charset		= 0;
1706 	vc->vc_need_wrap	= 0;
1707 	vc->vc_report_mouse	= 0;
1708 	vc->vc_utf              = default_utf8;
1709 	vc->vc_utf_count	= 0;
1710 
1711 	vc->vc_disp_ctrl	= 0;
1712 	vc->vc_toggle_meta	= 0;
1713 
1714 	vc->vc_decscnm		= 0;
1715 	vc->vc_decom		= 0;
1716 	vc->vc_decawm		= 1;
1717 	vc->vc_deccm		= global_cursor_default;
1718 	vc->vc_decim		= 0;
1719 
1720 	vt_reset_keyboard(vc->vc_num);
1721 
1722 	vc->vc_cursor_type = cur_default;
1723 	vc->vc_complement_mask = vc->vc_s_complement_mask;
1724 
1725 	default_attr(vc);
1726 	update_attr(vc);
1727 
1728 	vc->vc_tab_stop[0]	= 0x01010100;
1729 	vc->vc_tab_stop[1]	=
1730 	vc->vc_tab_stop[2]	=
1731 	vc->vc_tab_stop[3]	=
1732 	vc->vc_tab_stop[4]	=
1733 	vc->vc_tab_stop[5]	=
1734 	vc->vc_tab_stop[6]	=
1735 	vc->vc_tab_stop[7]	= 0x01010101;
1736 
1737 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1738 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1739 	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1740 
1741 	gotoxy(vc, 0, 0);
1742 	save_cur(vc);
1743 	if (do_clear)
1744 	    csi_J(vc, 2);
1745 }
1746 
1747 /* console_lock is held */
1748 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
1749 {
1750 	/*
1751 	 *  Control characters can be used in the _middle_
1752 	 *  of an escape sequence.
1753 	 */
1754 	if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
1755 		return;
1756 	switch (c) {
1757 	case 0:
1758 		return;
1759 	case 7:
1760 		if (vc->vc_state == ESosc)
1761 			vc->vc_state = ESnormal;
1762 		else if (vc->vc_bell_duration)
1763 			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
1764 		return;
1765 	case 8:
1766 		bs(vc);
1767 		return;
1768 	case 9:
1769 		vc->vc_pos -= (vc->vc_x << 1);
1770 		while (vc->vc_x < vc->vc_cols - 1) {
1771 			vc->vc_x++;
1772 			if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
1773 				break;
1774 		}
1775 		vc->vc_pos += (vc->vc_x << 1);
1776 		notify_write(vc, '\t');
1777 		return;
1778 	case 10: case 11: case 12:
1779 		lf(vc);
1780 		if (!is_kbd(vc, lnm))
1781 			return;
1782 	case 13:
1783 		cr(vc);
1784 		return;
1785 	case 14:
1786 		vc->vc_charset = 1;
1787 		vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
1788 		vc->vc_disp_ctrl = 1;
1789 		return;
1790 	case 15:
1791 		vc->vc_charset = 0;
1792 		vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
1793 		vc->vc_disp_ctrl = 0;
1794 		return;
1795 	case 24: case 26:
1796 		vc->vc_state = ESnormal;
1797 		return;
1798 	case 27:
1799 		vc->vc_state = ESesc;
1800 		return;
1801 	case 127:
1802 		del(vc);
1803 		return;
1804 	case 128+27:
1805 		vc->vc_state = ESsquare;
1806 		return;
1807 	}
1808 	switch(vc->vc_state) {
1809 	case ESesc:
1810 		vc->vc_state = ESnormal;
1811 		switch (c) {
1812 		case '[':
1813 			vc->vc_state = ESsquare;
1814 			return;
1815 		case ']':
1816 			vc->vc_state = ESnonstd;
1817 			return;
1818 		case '%':
1819 			vc->vc_state = ESpercent;
1820 			return;
1821 		case 'E':
1822 			cr(vc);
1823 			lf(vc);
1824 			return;
1825 		case 'M':
1826 			ri(vc);
1827 			return;
1828 		case 'D':
1829 			lf(vc);
1830 			return;
1831 		case 'H':
1832 			vc->vc_tab_stop[vc->vc_x >> 5] |= (1 << (vc->vc_x & 31));
1833 			return;
1834 		case 'Z':
1835 			respond_ID(tty);
1836 			return;
1837 		case '7':
1838 			save_cur(vc);
1839 			return;
1840 		case '8':
1841 			restore_cur(vc);
1842 			return;
1843 		case '(':
1844 			vc->vc_state = ESsetG0;
1845 			return;
1846 		case ')':
1847 			vc->vc_state = ESsetG1;
1848 			return;
1849 		case '#':
1850 			vc->vc_state = EShash;
1851 			return;
1852 		case 'c':
1853 			reset_terminal(vc, 1);
1854 			return;
1855 		case '>':  /* Numeric keypad */
1856 			clr_kbd(vc, kbdapplic);
1857 			return;
1858 		case '=':  /* Appl. keypad */
1859 			set_kbd(vc, kbdapplic);
1860 			return;
1861 		}
1862 		return;
1863 	case ESnonstd:
1864 		if (c=='P') {   /* palette escape sequence */
1865 			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1866 				vc->vc_par[vc->vc_npar] = 0;
1867 			vc->vc_npar = 0;
1868 			vc->vc_state = ESpalette;
1869 			return;
1870 		} else if (c=='R') {   /* reset palette */
1871 			reset_palette(vc);
1872 			vc->vc_state = ESnormal;
1873 		} else if (c>='0' && c<='9')
1874 			vc->vc_state = ESosc;
1875 		else
1876 			vc->vc_state = ESnormal;
1877 		return;
1878 	case ESpalette:
1879 		if (isxdigit(c)) {
1880 			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
1881 			if (vc->vc_npar == 7) {
1882 				int i = vc->vc_par[0] * 3, j = 1;
1883 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1884 				vc->vc_palette[i++] += vc->vc_par[j++];
1885 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1886 				vc->vc_palette[i++] += vc->vc_par[j++];
1887 				vc->vc_palette[i] = 16 * vc->vc_par[j++];
1888 				vc->vc_palette[i] += vc->vc_par[j];
1889 				set_palette(vc);
1890 				vc->vc_state = ESnormal;
1891 			}
1892 		} else
1893 			vc->vc_state = ESnormal;
1894 		return;
1895 	case ESsquare:
1896 		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
1897 			vc->vc_par[vc->vc_npar] = 0;
1898 		vc->vc_npar = 0;
1899 		vc->vc_state = ESgetpars;
1900 		if (c == '[') { /* Function key */
1901 			vc->vc_state=ESfunckey;
1902 			return;
1903 		}
1904 		vc->vc_ques = (c == '?');
1905 		if (vc->vc_ques)
1906 			return;
1907 	case ESgetpars:
1908 		if (c == ';' && vc->vc_npar < NPAR - 1) {
1909 			vc->vc_npar++;
1910 			return;
1911 		} else if (c>='0' && c<='9') {
1912 			vc->vc_par[vc->vc_npar] *= 10;
1913 			vc->vc_par[vc->vc_npar] += c - '0';
1914 			return;
1915 		}
1916 		vc->vc_state = ESnormal;
1917 		switch(c) {
1918 		case 'h':
1919 			set_mode(vc, 1);
1920 			return;
1921 		case 'l':
1922 			set_mode(vc, 0);
1923 			return;
1924 		case 'c':
1925 			if (vc->vc_ques) {
1926 				if (vc->vc_par[0])
1927 					vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
1928 				else
1929 					vc->vc_cursor_type = cur_default;
1930 				return;
1931 			}
1932 			break;
1933 		case 'm':
1934 			if (vc->vc_ques) {
1935 				clear_selection();
1936 				if (vc->vc_par[0])
1937 					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
1938 				else
1939 					vc->vc_complement_mask = vc->vc_s_complement_mask;
1940 				return;
1941 			}
1942 			break;
1943 		case 'n':
1944 			if (!vc->vc_ques) {
1945 				if (vc->vc_par[0] == 5)
1946 					status_report(tty);
1947 				else if (vc->vc_par[0] == 6)
1948 					cursor_report(vc, tty);
1949 			}
1950 			return;
1951 		}
1952 		if (vc->vc_ques) {
1953 			vc->vc_ques = 0;
1954 			return;
1955 		}
1956 		switch(c) {
1957 		case 'G': case '`':
1958 			if (vc->vc_par[0])
1959 				vc->vc_par[0]--;
1960 			gotoxy(vc, vc->vc_par[0], vc->vc_y);
1961 			return;
1962 		case 'A':
1963 			if (!vc->vc_par[0])
1964 				vc->vc_par[0]++;
1965 			gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
1966 			return;
1967 		case 'B': case 'e':
1968 			if (!vc->vc_par[0])
1969 				vc->vc_par[0]++;
1970 			gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
1971 			return;
1972 		case 'C': case 'a':
1973 			if (!vc->vc_par[0])
1974 				vc->vc_par[0]++;
1975 			gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
1976 			return;
1977 		case 'D':
1978 			if (!vc->vc_par[0])
1979 				vc->vc_par[0]++;
1980 			gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
1981 			return;
1982 		case 'E':
1983 			if (!vc->vc_par[0])
1984 				vc->vc_par[0]++;
1985 			gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
1986 			return;
1987 		case 'F':
1988 			if (!vc->vc_par[0])
1989 				vc->vc_par[0]++;
1990 			gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
1991 			return;
1992 		case 'd':
1993 			if (vc->vc_par[0])
1994 				vc->vc_par[0]--;
1995 			gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
1996 			return;
1997 		case 'H': case 'f':
1998 			if (vc->vc_par[0])
1999 				vc->vc_par[0]--;
2000 			if (vc->vc_par[1])
2001 				vc->vc_par[1]--;
2002 			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2003 			return;
2004 		case 'J':
2005 			csi_J(vc, vc->vc_par[0]);
2006 			return;
2007 		case 'K':
2008 			csi_K(vc, vc->vc_par[0]);
2009 			return;
2010 		case 'L':
2011 			csi_L(vc, vc->vc_par[0]);
2012 			return;
2013 		case 'M':
2014 			csi_M(vc, vc->vc_par[0]);
2015 			return;
2016 		case 'P':
2017 			csi_P(vc, vc->vc_par[0]);
2018 			return;
2019 		case 'c':
2020 			if (!vc->vc_par[0])
2021 				respond_ID(tty);
2022 			return;
2023 		case 'g':
2024 			if (!vc->vc_par[0])
2025 				vc->vc_tab_stop[vc->vc_x >> 5] &= ~(1 << (vc->vc_x & 31));
2026 			else if (vc->vc_par[0] == 3) {
2027 				vc->vc_tab_stop[0] =
2028 					vc->vc_tab_stop[1] =
2029 					vc->vc_tab_stop[2] =
2030 					vc->vc_tab_stop[3] =
2031 					vc->vc_tab_stop[4] =
2032 					vc->vc_tab_stop[5] =
2033 					vc->vc_tab_stop[6] =
2034 					vc->vc_tab_stop[7] = 0;
2035 			}
2036 			return;
2037 		case 'm':
2038 			csi_m(vc);
2039 			return;
2040 		case 'q': /* DECLL - but only 3 leds */
2041 			/* map 0,1,2,3 to 0,1,2,4 */
2042 			if (vc->vc_par[0] < 4)
2043 				vt_set_led_state(vc->vc_num,
2044 					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2045 			return;
2046 		case 'r':
2047 			if (!vc->vc_par[0])
2048 				vc->vc_par[0]++;
2049 			if (!vc->vc_par[1])
2050 				vc->vc_par[1] = vc->vc_rows;
2051 			/* Minimum allowed region is 2 lines */
2052 			if (vc->vc_par[0] < vc->vc_par[1] &&
2053 			    vc->vc_par[1] <= vc->vc_rows) {
2054 				vc->vc_top = vc->vc_par[0] - 1;
2055 				vc->vc_bottom = vc->vc_par[1];
2056 				gotoxay(vc, 0, 0);
2057 			}
2058 			return;
2059 		case 's':
2060 			save_cur(vc);
2061 			return;
2062 		case 'u':
2063 			restore_cur(vc);
2064 			return;
2065 		case 'X':
2066 			csi_X(vc, vc->vc_par[0]);
2067 			return;
2068 		case '@':
2069 			csi_at(vc, vc->vc_par[0]);
2070 			return;
2071 		case ']': /* setterm functions */
2072 			setterm_command(vc);
2073 			return;
2074 		}
2075 		return;
2076 	case ESpercent:
2077 		vc->vc_state = ESnormal;
2078 		switch (c) {
2079 		case '@':  /* defined in ISO 2022 */
2080 			vc->vc_utf = 0;
2081 			return;
2082 		case 'G':  /* prelim official escape code */
2083 		case '8':  /* retained for compatibility */
2084 			vc->vc_utf = 1;
2085 			return;
2086 		}
2087 		return;
2088 	case ESfunckey:
2089 		vc->vc_state = ESnormal;
2090 		return;
2091 	case EShash:
2092 		vc->vc_state = ESnormal;
2093 		if (c == '8') {
2094 			/* DEC screen alignment test. kludge :-) */
2095 			vc->vc_video_erase_char =
2096 				(vc->vc_video_erase_char & 0xff00) | 'E';
2097 			csi_J(vc, 2);
2098 			vc->vc_video_erase_char =
2099 				(vc->vc_video_erase_char & 0xff00) | ' ';
2100 			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2101 		}
2102 		return;
2103 	case ESsetG0:
2104 		if (c == '0')
2105 			vc->vc_G0_charset = GRAF_MAP;
2106 		else if (c == 'B')
2107 			vc->vc_G0_charset = LAT1_MAP;
2108 		else if (c == 'U')
2109 			vc->vc_G0_charset = IBMPC_MAP;
2110 		else if (c == 'K')
2111 			vc->vc_G0_charset = USER_MAP;
2112 		if (vc->vc_charset == 0)
2113 			vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2114 		vc->vc_state = ESnormal;
2115 		return;
2116 	case ESsetG1:
2117 		if (c == '0')
2118 			vc->vc_G1_charset = GRAF_MAP;
2119 		else if (c == 'B')
2120 			vc->vc_G1_charset = LAT1_MAP;
2121 		else if (c == 'U')
2122 			vc->vc_G1_charset = IBMPC_MAP;
2123 		else if (c == 'K')
2124 			vc->vc_G1_charset = USER_MAP;
2125 		if (vc->vc_charset == 1)
2126 			vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2127 		vc->vc_state = ESnormal;
2128 		return;
2129 	case ESosc:
2130 		return;
2131 	default:
2132 		vc->vc_state = ESnormal;
2133 	}
2134 }
2135 
2136 /* is_double_width() is based on the wcwidth() implementation by
2137  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2138  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2139  */
2140 struct interval {
2141 	uint32_t first;
2142 	uint32_t last;
2143 };
2144 
2145 static int bisearch(uint32_t ucs, const struct interval *table, int max)
2146 {
2147 	int min = 0;
2148 	int mid;
2149 
2150 	if (ucs < table[0].first || ucs > table[max].last)
2151 		return 0;
2152 	while (max >= min) {
2153 		mid = (min + max) / 2;
2154 		if (ucs > table[mid].last)
2155 			min = mid + 1;
2156 		else if (ucs < table[mid].first)
2157 			max = mid - 1;
2158 		else
2159 			return 1;
2160 	}
2161 	return 0;
2162 }
2163 
2164 static int is_double_width(uint32_t ucs)
2165 {
2166 	static const struct interval double_width[] = {
2167 		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2168 		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2169 		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2170 		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2171 	};
2172 	return bisearch(ucs, double_width, ARRAY_SIZE(double_width) - 1);
2173 }
2174 
2175 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2176 		unsigned long draw_to, int *draw_x)
2177 {
2178 	if (*draw_x < 0)
2179 		return;
2180 
2181 	vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2182 			(u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2183 	*draw_x = -1;
2184 }
2185 
2186 /* acquires console_lock */
2187 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2188 {
2189 	int c, tc, ok, n = 0, draw_x = -1;
2190 	unsigned int currcons;
2191 	unsigned long draw_from = 0, draw_to = 0;
2192 	struct vc_data *vc;
2193 	unsigned char vc_attr;
2194 	struct vt_notifier_param param;
2195 	uint8_t rescan;
2196 	uint8_t inverse;
2197 	uint8_t width;
2198 	u16 himask, charmask;
2199 
2200 	if (in_interrupt())
2201 		return count;
2202 
2203 	might_sleep();
2204 
2205 	console_lock();
2206 	vc = tty->driver_data;
2207 	if (vc == NULL) {
2208 		printk(KERN_ERR "vt: argh, driver_data is NULL !\n");
2209 		console_unlock();
2210 		return 0;
2211 	}
2212 
2213 	currcons = vc->vc_num;
2214 	if (!vc_cons_allocated(currcons)) {
2215 		/* could this happen? */
2216 		pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2217 		console_unlock();
2218 		return 0;
2219 	}
2220 
2221 	himask = vc->vc_hi_font_mask;
2222 	charmask = himask ? 0x1ff : 0xff;
2223 
2224 	/* undraw cursor first */
2225 	if (con_is_fg(vc))
2226 		hide_cursor(vc);
2227 
2228 	param.vc = vc;
2229 
2230 	while (!tty->stopped && count) {
2231 		int orig = *buf;
2232 		c = orig;
2233 		buf++;
2234 		n++;
2235 		count--;
2236 		rescan = 0;
2237 		inverse = 0;
2238 		width = 1;
2239 
2240 		/* Do no translation at all in control states */
2241 		if (vc->vc_state != ESnormal) {
2242 			tc = c;
2243 		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2244 		    /* Combine UTF-8 into Unicode in vc_utf_char.
2245 		     * vc_utf_count is the number of continuation bytes still
2246 		     * expected to arrive.
2247 		     * vc_npar is the number of continuation bytes arrived so
2248 		     * far
2249 		     */
2250 rescan_last_byte:
2251 		    if ((c & 0xc0) == 0x80) {
2252 			/* Continuation byte received */
2253 			static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2254 			if (vc->vc_utf_count) {
2255 			    vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2256 			    vc->vc_npar++;
2257 			    if (--vc->vc_utf_count) {
2258 				/* Still need some bytes */
2259 				continue;
2260 			    }
2261 			    /* Got a whole character */
2262 			    c = vc->vc_utf_char;
2263 			    /* Reject overlong sequences */
2264 			    if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2265 					c > utf8_length_changes[vc->vc_npar])
2266 				c = 0xfffd;
2267 			} else {
2268 			    /* Unexpected continuation byte */
2269 			    vc->vc_utf_count = 0;
2270 			    c = 0xfffd;
2271 			}
2272 		    } else {
2273 			/* Single ASCII byte or first byte of a sequence received */
2274 			if (vc->vc_utf_count) {
2275 			    /* Continuation byte expected */
2276 			    rescan = 1;
2277 			    vc->vc_utf_count = 0;
2278 			    c = 0xfffd;
2279 			} else if (c > 0x7f) {
2280 			    /* First byte of a multibyte sequence received */
2281 			    vc->vc_npar = 0;
2282 			    if ((c & 0xe0) == 0xc0) {
2283 				vc->vc_utf_count = 1;
2284 				vc->vc_utf_char = (c & 0x1f);
2285 			    } else if ((c & 0xf0) == 0xe0) {
2286 				vc->vc_utf_count = 2;
2287 				vc->vc_utf_char = (c & 0x0f);
2288 			    } else if ((c & 0xf8) == 0xf0) {
2289 				vc->vc_utf_count = 3;
2290 				vc->vc_utf_char = (c & 0x07);
2291 			    } else if ((c & 0xfc) == 0xf8) {
2292 				vc->vc_utf_count = 4;
2293 				vc->vc_utf_char = (c & 0x03);
2294 			    } else if ((c & 0xfe) == 0xfc) {
2295 				vc->vc_utf_count = 5;
2296 				vc->vc_utf_char = (c & 0x01);
2297 			    } else {
2298 				/* 254 and 255 are invalid */
2299 				c = 0xfffd;
2300 			    }
2301 			    if (vc->vc_utf_count) {
2302 				/* Still need some bytes */
2303 				continue;
2304 			    }
2305 			}
2306 			/* Nothing to do if an ASCII byte was received */
2307 		    }
2308 		    /* End of UTF-8 decoding. */
2309 		    /* c is the received character, or U+FFFD for invalid sequences. */
2310 		    /* Replace invalid Unicode code points with U+FFFD too */
2311 		    if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2312 			c = 0xfffd;
2313 		    tc = c;
2314 		} else {	/* no utf or alternate charset mode */
2315 		    tc = vc_translate(vc, c);
2316 		}
2317 
2318 		param.c = tc;
2319 		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2320 					&param) == NOTIFY_STOP)
2321 			continue;
2322 
2323                 /* If the original code was a control character we
2324                  * only allow a glyph to be displayed if the code is
2325                  * not normally used (such as for cursor movement) or
2326                  * if the disp_ctrl mode has been explicitly enabled.
2327                  * Certain characters (as given by the CTRL_ALWAYS
2328                  * bitmap) are always displayed as control characters,
2329                  * as the console would be pretty useless without
2330                  * them; to display an arbitrary font position use the
2331                  * direct-to-font zone in UTF-8 mode.
2332                  */
2333                 ok = tc && (c >= 32 ||
2334 			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2335 				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2336 			&& (c != 127 || vc->vc_disp_ctrl)
2337 			&& (c != 128+27);
2338 
2339 		if (vc->vc_state == ESnormal && ok) {
2340 			if (vc->vc_utf && !vc->vc_disp_ctrl) {
2341 				if (is_double_width(c))
2342 					width = 2;
2343 			}
2344 			/* Now try to find out how to display it */
2345 			tc = conv_uni_to_pc(vc, tc);
2346 			if (tc & ~charmask) {
2347 				if (tc == -1 || tc == -2) {
2348 				    continue; /* nothing to display */
2349 				}
2350 				/* Glyph not found */
2351 				if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2352 				    /* In legacy mode use the glyph we get by a 1:1 mapping.
2353 				       This would make absolutely no sense with Unicode in mind,
2354 				       but do this for ASCII characters since a font may lack
2355 				       Unicode mapping info and we don't want to end up with
2356 				       having question marks only. */
2357 				    tc = c;
2358 				} else {
2359 				    /* Display U+FFFD. If it's not found, display an inverse question mark. */
2360 				    tc = conv_uni_to_pc(vc, 0xfffd);
2361 				    if (tc < 0) {
2362 					inverse = 1;
2363 					tc = conv_uni_to_pc(vc, '?');
2364 					if (tc < 0) tc = '?';
2365 				    }
2366 				}
2367 			}
2368 
2369 			if (!inverse) {
2370 				vc_attr = vc->vc_attr;
2371 			} else {
2372 				/* invert vc_attr */
2373 				if (!vc->vc_can_do_color) {
2374 					vc_attr = (vc->vc_attr) ^ 0x08;
2375 				} else if (vc->vc_hi_font_mask == 0x100) {
2376 					vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2377 				} else {
2378 					vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2379 				}
2380 				con_flush(vc, draw_from, draw_to, &draw_x);
2381 			}
2382 
2383 			while (1) {
2384 				if (vc->vc_need_wrap || vc->vc_decim)
2385 					con_flush(vc, draw_from, draw_to,
2386 							&draw_x);
2387 				if (vc->vc_need_wrap) {
2388 					cr(vc);
2389 					lf(vc);
2390 				}
2391 				if (vc->vc_decim)
2392 					insert_char(vc, 1);
2393 				scr_writew(himask ?
2394 					     ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2395 					     (vc_attr << 8) + tc,
2396 					   (u16 *) vc->vc_pos);
2397 				if (con_should_update(vc) && draw_x < 0) {
2398 					draw_x = vc->vc_x;
2399 					draw_from = vc->vc_pos;
2400 				}
2401 				if (vc->vc_x == vc->vc_cols - 1) {
2402 					vc->vc_need_wrap = vc->vc_decawm;
2403 					draw_to = vc->vc_pos + 2;
2404 				} else {
2405 					vc->vc_x++;
2406 					draw_to = (vc->vc_pos += 2);
2407 				}
2408 
2409 				if (!--width) break;
2410 
2411 				tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2412 				if (tc < 0) tc = ' ';
2413 			}
2414 			notify_write(vc, c);
2415 
2416 			if (inverse)
2417 				con_flush(vc, draw_from, draw_to, &draw_x);
2418 
2419 			if (rescan) {
2420 				rescan = 0;
2421 				inverse = 0;
2422 				width = 1;
2423 				c = orig;
2424 				goto rescan_last_byte;
2425 			}
2426 			continue;
2427 		}
2428 		con_flush(vc, draw_from, draw_to, &draw_x);
2429 		do_con_trol(tty, vc, orig);
2430 	}
2431 	con_flush(vc, draw_from, draw_to, &draw_x);
2432 	console_conditional_schedule();
2433 	console_unlock();
2434 	notify_update(vc);
2435 	return n;
2436 }
2437 
2438 /*
2439  * This is the console switching callback.
2440  *
2441  * Doing console switching in a process context allows
2442  * us to do the switches asynchronously (needed when we want
2443  * to switch due to a keyboard interrupt).  Synchronization
2444  * with other console code and prevention of re-entrancy is
2445  * ensured with console_lock.
2446  */
2447 static void console_callback(struct work_struct *ignored)
2448 {
2449 	console_lock();
2450 
2451 	if (want_console >= 0) {
2452 		if (want_console != fg_console &&
2453 		    vc_cons_allocated(want_console)) {
2454 			hide_cursor(vc_cons[fg_console].d);
2455 			change_console(vc_cons[want_console].d);
2456 			/* we only changed when the console had already
2457 			   been allocated - a new console is not created
2458 			   in an interrupt routine */
2459 		}
2460 		want_console = -1;
2461 	}
2462 	if (do_poke_blanked_console) { /* do not unblank for a LED change */
2463 		do_poke_blanked_console = 0;
2464 		poke_blanked_console();
2465 	}
2466 	if (scrollback_delta) {
2467 		struct vc_data *vc = vc_cons[fg_console].d;
2468 		clear_selection();
2469 		if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2470 			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2471 		scrollback_delta = 0;
2472 	}
2473 	if (blank_timer_expired) {
2474 		do_blank_screen(0);
2475 		blank_timer_expired = 0;
2476 	}
2477 	notify_update(vc_cons[fg_console].d);
2478 
2479 	console_unlock();
2480 }
2481 
2482 int set_console(int nr)
2483 {
2484 	struct vc_data *vc = vc_cons[fg_console].d;
2485 
2486 	if (!vc_cons_allocated(nr) || vt_dont_switch ||
2487 		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2488 
2489 		/*
2490 		 * Console switch will fail in console_callback() or
2491 		 * change_console() so there is no point scheduling
2492 		 * the callback
2493 		 *
2494 		 * Existing set_console() users don't check the return
2495 		 * value so this shouldn't break anything
2496 		 */
2497 		return -EINVAL;
2498 	}
2499 
2500 	want_console = nr;
2501 	schedule_console_callback();
2502 
2503 	return 0;
2504 }
2505 
2506 struct tty_driver *console_driver;
2507 
2508 #ifdef CONFIG_VT_CONSOLE
2509 
2510 /**
2511  * vt_kmsg_redirect() - Sets/gets the kernel message console
2512  * @new:	The new virtual terminal number or -1 if the console should stay
2513  * 		unchanged
2514  *
2515  * By default, the kernel messages are always printed on the current virtual
2516  * console. However, the user may modify that default with the
2517  * TIOCL_SETKMSGREDIRECT ioctl call.
2518  *
2519  * This function sets the kernel message console to be @new. It returns the old
2520  * virtual console number. The virtual terminal number 0 (both as parameter and
2521  * return value) means no redirection (i.e. always printed on the currently
2522  * active console).
2523  *
2524  * The parameter -1 means that only the current console is returned, but the
2525  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2526  * case to make the code more understandable.
2527  *
2528  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2529  * the parameter and always returns 0.
2530  */
2531 int vt_kmsg_redirect(int new)
2532 {
2533 	static int kmsg_con;
2534 
2535 	if (new != -1)
2536 		return xchg(&kmsg_con, new);
2537 	else
2538 		return kmsg_con;
2539 }
2540 
2541 /*
2542  *	Console on virtual terminal
2543  *
2544  * The console must be locked when we get here.
2545  */
2546 
2547 static void vt_console_print(struct console *co, const char *b, unsigned count)
2548 {
2549 	struct vc_data *vc = vc_cons[fg_console].d;
2550 	unsigned char c;
2551 	static DEFINE_SPINLOCK(printing_lock);
2552 	const ushort *start;
2553 	ushort cnt = 0;
2554 	ushort myx;
2555 	int kmsg_console;
2556 
2557 	/* console busy or not yet initialized */
2558 	if (!printable)
2559 		return;
2560 	if (!spin_trylock(&printing_lock))
2561 		return;
2562 
2563 	kmsg_console = vt_get_kmsg_redirect();
2564 	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2565 		vc = vc_cons[kmsg_console - 1].d;
2566 
2567 	/* read `x' only after setting currcons properly (otherwise
2568 	   the `x' macro will read the x of the foreground console). */
2569 	myx = vc->vc_x;
2570 
2571 	if (!vc_cons_allocated(fg_console)) {
2572 		/* impossible */
2573 		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2574 		goto quit;
2575 	}
2576 
2577 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
2578 		goto quit;
2579 
2580 	/* undraw cursor first */
2581 	if (con_is_fg(vc))
2582 		hide_cursor(vc);
2583 
2584 	start = (ushort *)vc->vc_pos;
2585 
2586 	/* Contrived structure to try to emulate original need_wrap behaviour
2587 	 * Problems caused when we have need_wrap set on '\n' character */
2588 	while (count--) {
2589 		c = *b++;
2590 		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2591 			if (cnt > 0) {
2592 				if (con_is_visible(vc))
2593 					vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2594 				vc->vc_x += cnt;
2595 				if (vc->vc_need_wrap)
2596 					vc->vc_x--;
2597 				cnt = 0;
2598 			}
2599 			if (c == 8) {		/* backspace */
2600 				bs(vc);
2601 				start = (ushort *)vc->vc_pos;
2602 				myx = vc->vc_x;
2603 				continue;
2604 			}
2605 			if (c != 13)
2606 				lf(vc);
2607 			cr(vc);
2608 			start = (ushort *)vc->vc_pos;
2609 			myx = vc->vc_x;
2610 			if (c == 10 || c == 13)
2611 				continue;
2612 		}
2613 		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2614 		notify_write(vc, c);
2615 		cnt++;
2616 		if (myx == vc->vc_cols - 1) {
2617 			vc->vc_need_wrap = 1;
2618 			continue;
2619 		}
2620 		vc->vc_pos += 2;
2621 		myx++;
2622 	}
2623 	if (cnt > 0) {
2624 		if (con_is_visible(vc))
2625 			vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2626 		vc->vc_x += cnt;
2627 		if (vc->vc_x == vc->vc_cols) {
2628 			vc->vc_x--;
2629 			vc->vc_need_wrap = 1;
2630 		}
2631 	}
2632 	set_cursor(vc);
2633 	notify_update(vc);
2634 
2635 quit:
2636 	spin_unlock(&printing_lock);
2637 }
2638 
2639 static struct tty_driver *vt_console_device(struct console *c, int *index)
2640 {
2641 	*index = c->index ? c->index-1 : fg_console;
2642 	return console_driver;
2643 }
2644 
2645 static struct console vt_console_driver = {
2646 	.name		= "tty",
2647 	.write		= vt_console_print,
2648 	.device		= vt_console_device,
2649 	.unblank	= unblank_screen,
2650 	.flags		= CON_PRINTBUFFER,
2651 	.index		= -1,
2652 };
2653 #endif
2654 
2655 /*
2656  *	Handling of Linux-specific VC ioctls
2657  */
2658 
2659 /*
2660  * Generally a bit racy with respect to console_lock();.
2661  *
2662  * There are some functions which don't need it.
2663  *
2664  * There are some functions which can sleep for arbitrary periods
2665  * (paste_selection) but we don't need the lock there anyway.
2666  *
2667  * set_selection has locking, and definitely needs it
2668  */
2669 
2670 int tioclinux(struct tty_struct *tty, unsigned long arg)
2671 {
2672 	char type, data;
2673 	char __user *p = (char __user *)arg;
2674 	int lines;
2675 	int ret;
2676 
2677 	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
2678 		return -EPERM;
2679 	if (get_user(type, p))
2680 		return -EFAULT;
2681 	ret = 0;
2682 
2683 	switch (type)
2684 	{
2685 		case TIOCL_SETSEL:
2686 			console_lock();
2687 			ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
2688 			console_unlock();
2689 			break;
2690 		case TIOCL_PASTESEL:
2691 			ret = paste_selection(tty);
2692 			break;
2693 		case TIOCL_UNBLANKSCREEN:
2694 			console_lock();
2695 			unblank_screen();
2696 			console_unlock();
2697 			break;
2698 		case TIOCL_SELLOADLUT:
2699 			console_lock();
2700 			ret = sel_loadlut(p);
2701 			console_unlock();
2702 			break;
2703 		case TIOCL_GETSHIFTSTATE:
2704 
2705 	/*
2706 	 * Make it possible to react to Shift+Mousebutton.
2707 	 * Note that 'shift_state' is an undocumented
2708 	 * kernel-internal variable; programs not closely
2709 	 * related to the kernel should not use this.
2710 	 */
2711 			data = vt_get_shift_state();
2712 			ret = __put_user(data, p);
2713 			break;
2714 		case TIOCL_GETMOUSEREPORTING:
2715 			console_lock();	/* May be overkill */
2716 			data = mouse_reporting();
2717 			console_unlock();
2718 			ret = __put_user(data, p);
2719 			break;
2720 		case TIOCL_SETVESABLANK:
2721 			console_lock();
2722 			ret = set_vesa_blanking(p);
2723 			console_unlock();
2724 			break;
2725 		case TIOCL_GETKMSGREDIRECT:
2726 			data = vt_get_kmsg_redirect();
2727 			ret = __put_user(data, p);
2728 			break;
2729 		case TIOCL_SETKMSGREDIRECT:
2730 			if (!capable(CAP_SYS_ADMIN)) {
2731 				ret = -EPERM;
2732 			} else {
2733 				if (get_user(data, p+1))
2734 					ret = -EFAULT;
2735 				else
2736 					vt_kmsg_redirect(data);
2737 			}
2738 			break;
2739 		case TIOCL_GETFGCONSOLE:
2740 			/* No locking needed as this is a transiently
2741 			   correct return anyway if the caller hasn't
2742 			   disabled switching */
2743 			ret = fg_console;
2744 			break;
2745 		case TIOCL_SCROLLCONSOLE:
2746 			if (get_user(lines, (s32 __user *)(p+4))) {
2747 				ret = -EFAULT;
2748 			} else {
2749 				/* Need the console lock here. Note that lots
2750 				   of other calls need fixing before the lock
2751 				   is actually useful ! */
2752 				console_lock();
2753 				scrollfront(vc_cons[fg_console].d, lines);
2754 				console_unlock();
2755 				ret = 0;
2756 			}
2757 			break;
2758 		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
2759 			console_lock();
2760 			ignore_poke = 1;
2761 			do_blank_screen(0);
2762 			console_unlock();
2763 			break;
2764 		case TIOCL_BLANKEDSCREEN:
2765 			ret = console_blanked;
2766 			break;
2767 		default:
2768 			ret = -EINVAL;
2769 			break;
2770 	}
2771 	return ret;
2772 }
2773 
2774 /*
2775  * /dev/ttyN handling
2776  */
2777 
2778 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2779 {
2780 	int	retval;
2781 
2782 	retval = do_con_write(tty, buf, count);
2783 	con_flush_chars(tty);
2784 
2785 	return retval;
2786 }
2787 
2788 static int con_put_char(struct tty_struct *tty, unsigned char ch)
2789 {
2790 	if (in_interrupt())
2791 		return 0;	/* n_r3964 calls put_char() from interrupt context */
2792 	return do_con_write(tty, &ch, 1);
2793 }
2794 
2795 static int con_write_room(struct tty_struct *tty)
2796 {
2797 	if (tty->stopped)
2798 		return 0;
2799 	return 32768;		/* No limit, really; we're not buffering */
2800 }
2801 
2802 static int con_chars_in_buffer(struct tty_struct *tty)
2803 {
2804 	return 0;		/* we're not buffering */
2805 }
2806 
2807 /*
2808  * con_throttle and con_unthrottle are only used for
2809  * paste_selection(), which has to stuff in a large number of
2810  * characters...
2811  */
2812 static void con_throttle(struct tty_struct *tty)
2813 {
2814 }
2815 
2816 static void con_unthrottle(struct tty_struct *tty)
2817 {
2818 	struct vc_data *vc = tty->driver_data;
2819 
2820 	wake_up_interruptible(&vc->paste_wait);
2821 }
2822 
2823 /*
2824  * Turn the Scroll-Lock LED on when the tty is stopped
2825  */
2826 static void con_stop(struct tty_struct *tty)
2827 {
2828 	int console_num;
2829 	if (!tty)
2830 		return;
2831 	console_num = tty->index;
2832 	if (!vc_cons_allocated(console_num))
2833 		return;
2834 	vt_kbd_con_stop(console_num);
2835 }
2836 
2837 /*
2838  * Turn the Scroll-Lock LED off when the console is started
2839  */
2840 static void con_start(struct tty_struct *tty)
2841 {
2842 	int console_num;
2843 	if (!tty)
2844 		return;
2845 	console_num = tty->index;
2846 	if (!vc_cons_allocated(console_num))
2847 		return;
2848 	vt_kbd_con_start(console_num);
2849 }
2850 
2851 static void con_flush_chars(struct tty_struct *tty)
2852 {
2853 	struct vc_data *vc;
2854 
2855 	if (in_interrupt())	/* from flush_to_ldisc */
2856 		return;
2857 
2858 	/* if we race with con_close(), vt may be null */
2859 	console_lock();
2860 	vc = tty->driver_data;
2861 	if (vc)
2862 		set_cursor(vc);
2863 	console_unlock();
2864 }
2865 
2866 /*
2867  * Allocate the console screen memory.
2868  */
2869 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
2870 {
2871 	unsigned int currcons = tty->index;
2872 	struct vc_data *vc;
2873 	int ret;
2874 
2875 	console_lock();
2876 	ret = vc_allocate(currcons);
2877 	if (ret)
2878 		goto unlock;
2879 
2880 	vc = vc_cons[currcons].d;
2881 
2882 	/* Still being freed */
2883 	if (vc->port.tty) {
2884 		ret = -ERESTARTSYS;
2885 		goto unlock;
2886 	}
2887 
2888 	ret = tty_port_install(&vc->port, driver, tty);
2889 	if (ret)
2890 		goto unlock;
2891 
2892 	tty->driver_data = vc;
2893 	vc->port.tty = tty;
2894 
2895 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
2896 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
2897 		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
2898 	}
2899 	if (vc->vc_utf)
2900 		tty->termios.c_iflag |= IUTF8;
2901 	else
2902 		tty->termios.c_iflag &= ~IUTF8;
2903 unlock:
2904 	console_unlock();
2905 	return ret;
2906 }
2907 
2908 static int con_open(struct tty_struct *tty, struct file *filp)
2909 {
2910 	/* everything done in install */
2911 	return 0;
2912 }
2913 
2914 
2915 static void con_close(struct tty_struct *tty, struct file *filp)
2916 {
2917 	/* Nothing to do - we defer to shutdown */
2918 }
2919 
2920 static void con_shutdown(struct tty_struct *tty)
2921 {
2922 	struct vc_data *vc = tty->driver_data;
2923 	BUG_ON(vc == NULL);
2924 	console_lock();
2925 	vc->port.tty = NULL;
2926 	console_unlock();
2927 }
2928 
2929 static int default_color           = 7; /* white */
2930 static int default_italic_color    = 2; // green (ASCII)
2931 static int default_underline_color = 3; // cyan (ASCII)
2932 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
2933 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
2934 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
2935 
2936 static void vc_init(struct vc_data *vc, unsigned int rows,
2937 		    unsigned int cols, int do_clear)
2938 {
2939 	int j, k ;
2940 
2941 	vc->vc_cols = cols;
2942 	vc->vc_rows = rows;
2943 	vc->vc_size_row = cols << 1;
2944 	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
2945 
2946 	set_origin(vc);
2947 	vc->vc_pos = vc->vc_origin;
2948 	reset_vc(vc);
2949 	for (j=k=0; j<16; j++) {
2950 		vc->vc_palette[k++] = default_red[j] ;
2951 		vc->vc_palette[k++] = default_grn[j] ;
2952 		vc->vc_palette[k++] = default_blu[j] ;
2953 	}
2954 	vc->vc_def_color       = default_color;
2955 	vc->vc_ulcolor         = default_underline_color;
2956 	vc->vc_itcolor         = default_italic_color;
2957 	vc->vc_halfcolor       = 0x08;   /* grey */
2958 	init_waitqueue_head(&vc->paste_wait);
2959 	reset_terminal(vc, do_clear);
2960 }
2961 
2962 /*
2963  * This routine initializes console interrupts, and does nothing
2964  * else. If you want the screen to clear, call tty_write with
2965  * the appropriate escape-sequence.
2966  */
2967 
2968 static int __init con_init(void)
2969 {
2970 	const char *display_desc = NULL;
2971 	struct vc_data *vc;
2972 	unsigned int currcons = 0, i;
2973 
2974 	console_lock();
2975 
2976 	if (conswitchp)
2977 		display_desc = conswitchp->con_startup();
2978 	if (!display_desc) {
2979 		fg_console = 0;
2980 		console_unlock();
2981 		return 0;
2982 	}
2983 
2984 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
2985 		struct con_driver *con_driver = &registered_con_driver[i];
2986 
2987 		if (con_driver->con == NULL) {
2988 			con_driver->con = conswitchp;
2989 			con_driver->desc = display_desc;
2990 			con_driver->flag = CON_DRIVER_FLAG_INIT;
2991 			con_driver->first = 0;
2992 			con_driver->last = MAX_NR_CONSOLES - 1;
2993 			break;
2994 		}
2995 	}
2996 
2997 	for (i = 0; i < MAX_NR_CONSOLES; i++)
2998 		con_driver_map[i] = conswitchp;
2999 
3000 	if (blankinterval) {
3001 		blank_state = blank_normal_wait;
3002 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3003 	}
3004 
3005 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3006 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3007 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3008 		tty_port_init(&vc->port);
3009 		visual_init(vc, currcons, 1);
3010 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3011 		vc_init(vc, vc->vc_rows, vc->vc_cols,
3012 			currcons || !vc->vc_sw->con_save_screen);
3013 	}
3014 	currcons = fg_console = 0;
3015 	master_display_fg = vc = vc_cons[currcons].d;
3016 	set_origin(vc);
3017 	save_screen(vc);
3018 	gotoxy(vc, vc->vc_x, vc->vc_y);
3019 	csi_J(vc, 0);
3020 	update_screen(vc);
3021 	pr_info("Console: %s %s %dx%d\n",
3022 		vc->vc_can_do_color ? "colour" : "mono",
3023 		display_desc, vc->vc_cols, vc->vc_rows);
3024 	printable = 1;
3025 
3026 	console_unlock();
3027 
3028 #ifdef CONFIG_VT_CONSOLE
3029 	register_console(&vt_console_driver);
3030 #endif
3031 	return 0;
3032 }
3033 console_initcall(con_init);
3034 
3035 static const struct tty_operations con_ops = {
3036 	.install = con_install,
3037 	.open = con_open,
3038 	.close = con_close,
3039 	.write = con_write,
3040 	.write_room = con_write_room,
3041 	.put_char = con_put_char,
3042 	.flush_chars = con_flush_chars,
3043 	.chars_in_buffer = con_chars_in_buffer,
3044 	.ioctl = vt_ioctl,
3045 #ifdef CONFIG_COMPAT
3046 	.compat_ioctl = vt_compat_ioctl,
3047 #endif
3048 	.stop = con_stop,
3049 	.start = con_start,
3050 	.throttle = con_throttle,
3051 	.unthrottle = con_unthrottle,
3052 	.resize = vt_resize,
3053 	.shutdown = con_shutdown
3054 };
3055 
3056 static struct cdev vc0_cdev;
3057 
3058 static ssize_t show_tty_active(struct device *dev,
3059 				struct device_attribute *attr, char *buf)
3060 {
3061 	return sprintf(buf, "tty%d\n", fg_console + 1);
3062 }
3063 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3064 
3065 static struct attribute *vt_dev_attrs[] = {
3066 	&dev_attr_active.attr,
3067 	NULL
3068 };
3069 
3070 ATTRIBUTE_GROUPS(vt_dev);
3071 
3072 int __init vty_init(const struct file_operations *console_fops)
3073 {
3074 	cdev_init(&vc0_cdev, console_fops);
3075 	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3076 	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3077 		panic("Couldn't register /dev/tty0 driver\n");
3078 	tty0dev = device_create_with_groups(tty_class, NULL,
3079 					    MKDEV(TTY_MAJOR, 0), NULL,
3080 					    vt_dev_groups, "tty0");
3081 	if (IS_ERR(tty0dev))
3082 		tty0dev = NULL;
3083 
3084 	vcs_init();
3085 
3086 	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3087 	if (!console_driver)
3088 		panic("Couldn't allocate console driver\n");
3089 
3090 	console_driver->name = "tty";
3091 	console_driver->name_base = 1;
3092 	console_driver->major = TTY_MAJOR;
3093 	console_driver->minor_start = 1;
3094 	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3095 	console_driver->init_termios = tty_std_termios;
3096 	if (default_utf8)
3097 		console_driver->init_termios.c_iflag |= IUTF8;
3098 	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3099 	tty_set_operations(console_driver, &con_ops);
3100 	if (tty_register_driver(console_driver))
3101 		panic("Couldn't register console driver\n");
3102 	kbd_init();
3103 	console_map_init();
3104 #ifdef CONFIG_MDA_CONSOLE
3105 	mda_console_init();
3106 #endif
3107 	return 0;
3108 }
3109 
3110 #ifndef VT_SINGLE_DRIVER
3111 
3112 static struct class *vtconsole_class;
3113 
3114 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3115 			   int deflt)
3116 {
3117 	struct module *owner = csw->owner;
3118 	const char *desc = NULL;
3119 	struct con_driver *con_driver;
3120 	int i, j = -1, k = -1, retval = -ENODEV;
3121 
3122 	if (!try_module_get(owner))
3123 		return -ENODEV;
3124 
3125 	WARN_CONSOLE_UNLOCKED();
3126 
3127 	/* check if driver is registered */
3128 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3129 		con_driver = &registered_con_driver[i];
3130 
3131 		if (con_driver->con == csw) {
3132 			desc = con_driver->desc;
3133 			retval = 0;
3134 			break;
3135 		}
3136 	}
3137 
3138 	if (retval)
3139 		goto err;
3140 
3141 	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3142 		csw->con_startup();
3143 		con_driver->flag |= CON_DRIVER_FLAG_INIT;
3144 	}
3145 
3146 	if (deflt) {
3147 		if (conswitchp)
3148 			module_put(conswitchp->owner);
3149 
3150 		__module_get(owner);
3151 		conswitchp = csw;
3152 	}
3153 
3154 	first = max(first, con_driver->first);
3155 	last = min(last, con_driver->last);
3156 
3157 	for (i = first; i <= last; i++) {
3158 		int old_was_color;
3159 		struct vc_data *vc = vc_cons[i].d;
3160 
3161 		if (con_driver_map[i])
3162 			module_put(con_driver_map[i]->owner);
3163 		__module_get(owner);
3164 		con_driver_map[i] = csw;
3165 
3166 		if (!vc || !vc->vc_sw)
3167 			continue;
3168 
3169 		j = i;
3170 
3171 		if (con_is_visible(vc)) {
3172 			k = i;
3173 			save_screen(vc);
3174 		}
3175 
3176 		old_was_color = vc->vc_can_do_color;
3177 		vc->vc_sw->con_deinit(vc);
3178 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3179 		visual_init(vc, i, 0);
3180 		set_origin(vc);
3181 		update_attr(vc);
3182 
3183 		/* If the console changed between mono <-> color, then
3184 		 * the attributes in the screenbuf will be wrong.  The
3185 		 * following resets all attributes to something sane.
3186 		 */
3187 		if (old_was_color != vc->vc_can_do_color)
3188 			clear_buffer_attributes(vc);
3189 	}
3190 
3191 	pr_info("Console: switching ");
3192 	if (!deflt)
3193 		printk(KERN_CONT "consoles %d-%d ", first+1, last+1);
3194 	if (j >= 0) {
3195 		struct vc_data *vc = vc_cons[j].d;
3196 
3197 		printk(KERN_CONT "to %s %s %dx%d\n",
3198 		       vc->vc_can_do_color ? "colour" : "mono",
3199 		       desc, vc->vc_cols, vc->vc_rows);
3200 
3201 		if (k >= 0) {
3202 			vc = vc_cons[k].d;
3203 			update_screen(vc);
3204 		}
3205 	} else
3206 		printk(KERN_CONT "to %s\n", desc);
3207 
3208 	retval = 0;
3209 err:
3210 	module_put(owner);
3211 	return retval;
3212 };
3213 
3214 
3215 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3216 /* unlocked version of unbind_con_driver() */
3217 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3218 {
3219 	struct module *owner = csw->owner;
3220 	const struct consw *defcsw = NULL;
3221 	struct con_driver *con_driver = NULL, *con_back = NULL;
3222 	int i, retval = -ENODEV;
3223 
3224 	if (!try_module_get(owner))
3225 		return -ENODEV;
3226 
3227 	WARN_CONSOLE_UNLOCKED();
3228 
3229 	/* check if driver is registered and if it is unbindable */
3230 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3231 		con_driver = &registered_con_driver[i];
3232 
3233 		if (con_driver->con == csw &&
3234 		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3235 			retval = 0;
3236 			break;
3237 		}
3238 	}
3239 
3240 	if (retval)
3241 		goto err;
3242 
3243 	retval = -ENODEV;
3244 
3245 	/* check if backup driver exists */
3246 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3247 		con_back = &registered_con_driver[i];
3248 
3249 		if (con_back->con && con_back->con != csw) {
3250 			defcsw = con_back->con;
3251 			retval = 0;
3252 			break;
3253 		}
3254 	}
3255 
3256 	if (retval)
3257 		goto err;
3258 
3259 	if (!con_is_bound(csw))
3260 		goto err;
3261 
3262 	first = max(first, con_driver->first);
3263 	last = min(last, con_driver->last);
3264 
3265 	for (i = first; i <= last; i++) {
3266 		if (con_driver_map[i] == csw) {
3267 			module_put(csw->owner);
3268 			con_driver_map[i] = NULL;
3269 		}
3270 	}
3271 
3272 	if (!con_is_bound(defcsw)) {
3273 		const struct consw *defconsw = conswitchp;
3274 
3275 		defcsw->con_startup();
3276 		con_back->flag |= CON_DRIVER_FLAG_INIT;
3277 		/*
3278 		 * vgacon may change the default driver to point
3279 		 * to dummycon, we restore it here...
3280 		 */
3281 		conswitchp = defconsw;
3282 	}
3283 
3284 	if (!con_is_bound(csw))
3285 		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3286 
3287 	/* ignore return value, binding should not fail */
3288 	do_bind_con_driver(defcsw, first, last, deflt);
3289 err:
3290 	module_put(owner);
3291 	return retval;
3292 
3293 }
3294 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3295 
3296 static int vt_bind(struct con_driver *con)
3297 {
3298 	const struct consw *defcsw = NULL, *csw = NULL;
3299 	int i, more = 1, first = -1, last = -1, deflt = 0;
3300 
3301  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3302 		goto err;
3303 
3304 	csw = con->con;
3305 
3306 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3307 		struct con_driver *con = &registered_con_driver[i];
3308 
3309 		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3310 			defcsw = con->con;
3311 			break;
3312 		}
3313 	}
3314 
3315 	if (!defcsw)
3316 		goto err;
3317 
3318 	while (more) {
3319 		more = 0;
3320 
3321 		for (i = con->first; i <= con->last; i++) {
3322 			if (con_driver_map[i] == defcsw) {
3323 				if (first == -1)
3324 					first = i;
3325 				last = i;
3326 				more = 1;
3327 			} else if (first != -1)
3328 				break;
3329 		}
3330 
3331 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3332 			deflt = 1;
3333 
3334 		if (first != -1)
3335 			do_bind_con_driver(csw, first, last, deflt);
3336 
3337 		first = -1;
3338 		last = -1;
3339 		deflt = 0;
3340 	}
3341 
3342 err:
3343 	return 0;
3344 }
3345 
3346 static int vt_unbind(struct con_driver *con)
3347 {
3348 	const struct consw *csw = NULL;
3349 	int i, more = 1, first = -1, last = -1, deflt = 0;
3350 	int ret;
3351 
3352  	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3353 		goto err;
3354 
3355 	csw = con->con;
3356 
3357 	while (more) {
3358 		more = 0;
3359 
3360 		for (i = con->first; i <= con->last; i++) {
3361 			if (con_driver_map[i] == csw) {
3362 				if (first == -1)
3363 					first = i;
3364 				last = i;
3365 				more = 1;
3366 			} else if (first != -1)
3367 				break;
3368 		}
3369 
3370 		if (first == 0 && last == MAX_NR_CONSOLES -1)
3371 			deflt = 1;
3372 
3373 		if (first != -1) {
3374 			ret = do_unbind_con_driver(csw, first, last, deflt);
3375 			if (ret != 0)
3376 				return ret;
3377 		}
3378 
3379 		first = -1;
3380 		last = -1;
3381 		deflt = 0;
3382 	}
3383 
3384 err:
3385 	return 0;
3386 }
3387 #else
3388 static inline int vt_bind(struct con_driver *con)
3389 {
3390 	return 0;
3391 }
3392 static inline int vt_unbind(struct con_driver *con)
3393 {
3394 	return 0;
3395 }
3396 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3397 
3398 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3399 			  const char *buf, size_t count)
3400 {
3401 	struct con_driver *con = dev_get_drvdata(dev);
3402 	int bind = simple_strtoul(buf, NULL, 0);
3403 
3404 	console_lock();
3405 
3406 	if (bind)
3407 		vt_bind(con);
3408 	else
3409 		vt_unbind(con);
3410 
3411 	console_unlock();
3412 
3413 	return count;
3414 }
3415 
3416 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3417 			 char *buf)
3418 {
3419 	struct con_driver *con = dev_get_drvdata(dev);
3420 	int bind = con_is_bound(con->con);
3421 
3422 	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3423 }
3424 
3425 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3426 			 char *buf)
3427 {
3428 	struct con_driver *con = dev_get_drvdata(dev);
3429 
3430 	return snprintf(buf, PAGE_SIZE, "%s %s\n",
3431 			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3432 			 con->desc);
3433 
3434 }
3435 
3436 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3437 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3438 
3439 static struct attribute *con_dev_attrs[] = {
3440 	&dev_attr_bind.attr,
3441 	&dev_attr_name.attr,
3442 	NULL
3443 };
3444 
3445 ATTRIBUTE_GROUPS(con_dev);
3446 
3447 static int vtconsole_init_device(struct con_driver *con)
3448 {
3449 	con->flag |= CON_DRIVER_FLAG_ATTR;
3450 	return 0;
3451 }
3452 
3453 static void vtconsole_deinit_device(struct con_driver *con)
3454 {
3455 	con->flag &= ~CON_DRIVER_FLAG_ATTR;
3456 }
3457 
3458 /**
3459  * con_is_bound - checks if driver is bound to the console
3460  * @csw: console driver
3461  *
3462  * RETURNS: zero if unbound, nonzero if bound
3463  *
3464  * Drivers can call this and if zero, they should release
3465  * all resources allocated on con_startup()
3466  */
3467 int con_is_bound(const struct consw *csw)
3468 {
3469 	int i, bound = 0;
3470 
3471 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3472 		if (con_driver_map[i] == csw) {
3473 			bound = 1;
3474 			break;
3475 		}
3476 	}
3477 
3478 	return bound;
3479 }
3480 EXPORT_SYMBOL(con_is_bound);
3481 
3482 /**
3483  * con_debug_enter - prepare the console for the kernel debugger
3484  * @sw: console driver
3485  *
3486  * Called when the console is taken over by the kernel debugger, this
3487  * function needs to save the current console state, then put the console
3488  * into a state suitable for the kernel debugger.
3489  *
3490  * RETURNS:
3491  * Zero on success, nonzero if a failure occurred when trying to prepare
3492  * the console for the debugger.
3493  */
3494 int con_debug_enter(struct vc_data *vc)
3495 {
3496 	int ret = 0;
3497 
3498 	saved_fg_console = fg_console;
3499 	saved_last_console = last_console;
3500 	saved_want_console = want_console;
3501 	saved_vc_mode = vc->vc_mode;
3502 	saved_console_blanked = console_blanked;
3503 	vc->vc_mode = KD_TEXT;
3504 	console_blanked = 0;
3505 	if (vc->vc_sw->con_debug_enter)
3506 		ret = vc->vc_sw->con_debug_enter(vc);
3507 #ifdef CONFIG_KGDB_KDB
3508 	/* Set the initial LINES variable if it is not already set */
3509 	if (vc->vc_rows < 999) {
3510 		int linecount;
3511 		char lns[4];
3512 		const char *setargs[3] = {
3513 			"set",
3514 			"LINES",
3515 			lns,
3516 		};
3517 		if (kdbgetintenv(setargs[0], &linecount)) {
3518 			snprintf(lns, 4, "%i", vc->vc_rows);
3519 			kdb_set(2, setargs);
3520 		}
3521 	}
3522 	if (vc->vc_cols < 999) {
3523 		int colcount;
3524 		char cols[4];
3525 		const char *setargs[3] = {
3526 			"set",
3527 			"COLUMNS",
3528 			cols,
3529 		};
3530 		if (kdbgetintenv(setargs[0], &colcount)) {
3531 			snprintf(cols, 4, "%i", vc->vc_cols);
3532 			kdb_set(2, setargs);
3533 		}
3534 	}
3535 #endif /* CONFIG_KGDB_KDB */
3536 	return ret;
3537 }
3538 EXPORT_SYMBOL_GPL(con_debug_enter);
3539 
3540 /**
3541  * con_debug_leave - restore console state
3542  * @sw: console driver
3543  *
3544  * Restore the console state to what it was before the kernel debugger
3545  * was invoked.
3546  *
3547  * RETURNS:
3548  * Zero on success, nonzero if a failure occurred when trying to restore
3549  * the console.
3550  */
3551 int con_debug_leave(void)
3552 {
3553 	struct vc_data *vc;
3554 	int ret = 0;
3555 
3556 	fg_console = saved_fg_console;
3557 	last_console = saved_last_console;
3558 	want_console = saved_want_console;
3559 	console_blanked = saved_console_blanked;
3560 	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3561 
3562 	vc = vc_cons[fg_console].d;
3563 	if (vc->vc_sw->con_debug_leave)
3564 		ret = vc->vc_sw->con_debug_leave(vc);
3565 	return ret;
3566 }
3567 EXPORT_SYMBOL_GPL(con_debug_leave);
3568 
3569 static int do_register_con_driver(const struct consw *csw, int first, int last)
3570 {
3571 	struct module *owner = csw->owner;
3572 	struct con_driver *con_driver;
3573 	const char *desc;
3574 	int i, retval;
3575 
3576 	WARN_CONSOLE_UNLOCKED();
3577 
3578 	if (!try_module_get(owner))
3579 		return -ENODEV;
3580 
3581 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3582 		con_driver = &registered_con_driver[i];
3583 
3584 		/* already registered */
3585 		if (con_driver->con == csw) {
3586 			retval = -EBUSY;
3587 			goto err;
3588 		}
3589 	}
3590 
3591 	desc = csw->con_startup();
3592 	if (!desc) {
3593 		retval = -ENODEV;
3594 		goto err;
3595 	}
3596 
3597 	retval = -EINVAL;
3598 
3599 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3600 		con_driver = &registered_con_driver[i];
3601 
3602 		if (con_driver->con == NULL &&
3603 		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3604 			con_driver->con = csw;
3605 			con_driver->desc = desc;
3606 			con_driver->node = i;
3607 			con_driver->flag = CON_DRIVER_FLAG_MODULE |
3608 			                   CON_DRIVER_FLAG_INIT;
3609 			con_driver->first = first;
3610 			con_driver->last = last;
3611 			retval = 0;
3612 			break;
3613 		}
3614 	}
3615 
3616 	if (retval)
3617 		goto err;
3618 
3619 	con_driver->dev =
3620 		device_create_with_groups(vtconsole_class, NULL,
3621 					  MKDEV(0, con_driver->node),
3622 					  con_driver, con_dev_groups,
3623 					  "vtcon%i", con_driver->node);
3624 	if (IS_ERR(con_driver->dev)) {
3625 		printk(KERN_WARNING "Unable to create device for %s; "
3626 		       "errno = %ld\n", con_driver->desc,
3627 		       PTR_ERR(con_driver->dev));
3628 		con_driver->dev = NULL;
3629 	} else {
3630 		vtconsole_init_device(con_driver);
3631 	}
3632 
3633 err:
3634 	module_put(owner);
3635 	return retval;
3636 }
3637 
3638 
3639 /**
3640  * do_unregister_con_driver - unregister console driver from console layer
3641  * @csw: console driver
3642  *
3643  * DESCRIPTION: All drivers that registers to the console layer must
3644  * call this function upon exit, or if the console driver is in a state
3645  * where it won't be able to handle console services, such as the
3646  * framebuffer console without loaded framebuffer drivers.
3647  *
3648  * The driver must unbind first prior to unregistration.
3649  */
3650 int do_unregister_con_driver(const struct consw *csw)
3651 {
3652 	int i;
3653 
3654 	/* cannot unregister a bound driver */
3655 	if (con_is_bound(csw))
3656 		return -EBUSY;
3657 
3658 	if (csw == conswitchp)
3659 		return -EINVAL;
3660 
3661 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3662 		struct con_driver *con_driver = &registered_con_driver[i];
3663 
3664 		if (con_driver->con == csw) {
3665 			/*
3666 			 * Defer the removal of the sysfs entries since that
3667 			 * will acquire the kernfs s_active lock and we can't
3668 			 * acquire this lock while holding the console lock:
3669 			 * the unbind sysfs entry imposes already the opposite
3670 			 * order. Reset con already here to prevent any later
3671 			 * lookup to succeed and mark this slot as zombie, so
3672 			 * it won't get reused until we complete the removal
3673 			 * in the deferred work.
3674 			 */
3675 			con_driver->con = NULL;
3676 			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
3677 			schedule_work(&con_driver_unregister_work);
3678 
3679 			return 0;
3680 		}
3681 	}
3682 
3683 	return -ENODEV;
3684 }
3685 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
3686 
3687 static void con_driver_unregister_callback(struct work_struct *ignored)
3688 {
3689 	int i;
3690 
3691 	console_lock();
3692 
3693 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3694 		struct con_driver *con_driver = &registered_con_driver[i];
3695 
3696 		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
3697 			continue;
3698 
3699 		console_unlock();
3700 
3701 		vtconsole_deinit_device(con_driver);
3702 		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
3703 
3704 		console_lock();
3705 
3706 		if (WARN_ON_ONCE(con_driver->con))
3707 			con_driver->con = NULL;
3708 		con_driver->desc = NULL;
3709 		con_driver->dev = NULL;
3710 		con_driver->node = 0;
3711 		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
3712 		con_driver->flag = 0;
3713 		con_driver->first = 0;
3714 		con_driver->last = 0;
3715 	}
3716 
3717 	console_unlock();
3718 }
3719 
3720 /*
3721  *	If we support more console drivers, this function is used
3722  *	when a driver wants to take over some existing consoles
3723  *	and become default driver for newly opened ones.
3724  *
3725  *	do_take_over_console is basically a register followed by unbind
3726  */
3727 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
3728 {
3729 	int err;
3730 
3731 	err = do_register_con_driver(csw, first, last);
3732 	/*
3733 	 * If we get an busy error we still want to bind the console driver
3734 	 * and return success, as we may have unbound the console driver
3735 	 * but not unregistered it.
3736 	 */
3737 	if (err == -EBUSY)
3738 		err = 0;
3739 	if (!err)
3740 		do_bind_con_driver(csw, first, last, deflt);
3741 
3742 	return err;
3743 }
3744 EXPORT_SYMBOL_GPL(do_take_over_console);
3745 
3746 
3747 /*
3748  * give_up_console is a wrapper to unregister_con_driver. It will only
3749  * work if driver is fully unbound.
3750  */
3751 void give_up_console(const struct consw *csw)
3752 {
3753 	console_lock();
3754 	do_unregister_con_driver(csw);
3755 	console_unlock();
3756 }
3757 
3758 static int __init vtconsole_class_init(void)
3759 {
3760 	int i;
3761 
3762 	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
3763 	if (IS_ERR(vtconsole_class)) {
3764 		printk(KERN_WARNING "Unable to create vt console class; "
3765 		       "errno = %ld\n", PTR_ERR(vtconsole_class));
3766 		vtconsole_class = NULL;
3767 	}
3768 
3769 	/* Add system drivers to sysfs */
3770 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3771 		struct con_driver *con = &registered_con_driver[i];
3772 
3773 		if (con->con && !con->dev) {
3774 			con->dev =
3775 				device_create_with_groups(vtconsole_class, NULL,
3776 							  MKDEV(0, con->node),
3777 							  con, con_dev_groups,
3778 							  "vtcon%i", con->node);
3779 
3780 			if (IS_ERR(con->dev)) {
3781 				printk(KERN_WARNING "Unable to create "
3782 				       "device for %s; errno = %ld\n",
3783 				       con->desc, PTR_ERR(con->dev));
3784 				con->dev = NULL;
3785 			} else {
3786 				vtconsole_init_device(con);
3787 			}
3788 		}
3789 	}
3790 
3791 	return 0;
3792 }
3793 postcore_initcall(vtconsole_class_init);
3794 
3795 #endif
3796 
3797 /*
3798  *	Screen blanking
3799  */
3800 
3801 static int set_vesa_blanking(char __user *p)
3802 {
3803 	unsigned int mode;
3804 
3805 	if (get_user(mode, p + 1))
3806 		return -EFAULT;
3807 
3808 	vesa_blank_mode = (mode < 4) ? mode : 0;
3809 	return 0;
3810 }
3811 
3812 void do_blank_screen(int entering_gfx)
3813 {
3814 	struct vc_data *vc = vc_cons[fg_console].d;
3815 	int i;
3816 
3817 	WARN_CONSOLE_UNLOCKED();
3818 
3819 	if (console_blanked) {
3820 		if (blank_state == blank_vesa_wait) {
3821 			blank_state = blank_off;
3822 			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
3823 		}
3824 		return;
3825 	}
3826 
3827 	/* entering graphics mode? */
3828 	if (entering_gfx) {
3829 		hide_cursor(vc);
3830 		save_screen(vc);
3831 		vc->vc_sw->con_blank(vc, -1, 1);
3832 		console_blanked = fg_console + 1;
3833 		blank_state = blank_off;
3834 		set_origin(vc);
3835 		return;
3836 	}
3837 
3838 	if (blank_state != blank_normal_wait)
3839 		return;
3840 	blank_state = blank_off;
3841 
3842 	/* don't blank graphics */
3843 	if (vc->vc_mode != KD_TEXT) {
3844 		console_blanked = fg_console + 1;
3845 		return;
3846 	}
3847 
3848 	hide_cursor(vc);
3849 	del_timer_sync(&console_timer);
3850 	blank_timer_expired = 0;
3851 
3852 	save_screen(vc);
3853 	/* In case we need to reset origin, blanking hook returns 1 */
3854 	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
3855 	console_blanked = fg_console + 1;
3856 	if (i)
3857 		set_origin(vc);
3858 
3859 	if (console_blank_hook && console_blank_hook(1))
3860 		return;
3861 
3862 	if (vesa_off_interval && vesa_blank_mode) {
3863 		blank_state = blank_vesa_wait;
3864 		mod_timer(&console_timer, jiffies + vesa_off_interval);
3865 	}
3866 	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
3867 }
3868 EXPORT_SYMBOL(do_blank_screen);
3869 
3870 /*
3871  * Called by timer as well as from vt_console_driver
3872  */
3873 void do_unblank_screen(int leaving_gfx)
3874 {
3875 	struct vc_data *vc;
3876 
3877 	/* This should now always be called from a "sane" (read: can schedule)
3878 	 * context for the sake of the low level drivers, except in the special
3879 	 * case of oops_in_progress
3880 	 */
3881 	if (!oops_in_progress)
3882 		might_sleep();
3883 
3884 	WARN_CONSOLE_UNLOCKED();
3885 
3886 	ignore_poke = 0;
3887 	if (!console_blanked)
3888 		return;
3889 	if (!vc_cons_allocated(fg_console)) {
3890 		/* impossible */
3891 		pr_warn("unblank_screen: tty %d not allocated ??\n",
3892 			fg_console + 1);
3893 		return;
3894 	}
3895 	vc = vc_cons[fg_console].d;
3896 	/* Try to unblank in oops case too */
3897 	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
3898 		return; /* but leave console_blanked != 0 */
3899 
3900 	if (blankinterval) {
3901 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3902 		blank_state = blank_normal_wait;
3903 	}
3904 
3905 	console_blanked = 0;
3906 	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
3907 		/* Low-level driver cannot restore -> do it ourselves */
3908 		update_screen(vc);
3909 	if (console_blank_hook)
3910 		console_blank_hook(0);
3911 	set_palette(vc);
3912 	set_cursor(vc);
3913 	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
3914 }
3915 EXPORT_SYMBOL(do_unblank_screen);
3916 
3917 /*
3918  * This is called by the outside world to cause a forced unblank, mostly for
3919  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
3920  * call it with 1 as an argument and so force a mode restore... that may kill
3921  * X or at least garbage the screen but would also make the Oops visible...
3922  */
3923 void unblank_screen(void)
3924 {
3925 	do_unblank_screen(0);
3926 }
3927 
3928 /*
3929  * We defer the timer blanking to work queue so it can take the console mutex
3930  * (console operations can still happen at irq time, but only from printk which
3931  * has the console mutex. Not perfect yet, but better than no locking
3932  */
3933 static void blank_screen_t(unsigned long dummy)
3934 {
3935 	blank_timer_expired = 1;
3936 	schedule_work(&console_work);
3937 }
3938 
3939 void poke_blanked_console(void)
3940 {
3941 	WARN_CONSOLE_UNLOCKED();
3942 
3943 	/* Add this so we quickly catch whoever might call us in a non
3944 	 * safe context. Nowadays, unblank_screen() isn't to be called in
3945 	 * atomic contexts and is allowed to schedule (with the special case
3946 	 * of oops_in_progress, but that isn't of any concern for this
3947 	 * function. --BenH.
3948 	 */
3949 	might_sleep();
3950 
3951 	/* This isn't perfectly race free, but a race here would be mostly harmless,
3952 	 * at worse, we'll do a spurrious blank and it's unlikely
3953 	 */
3954 	del_timer(&console_timer);
3955 	blank_timer_expired = 0;
3956 
3957 	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
3958 		return;
3959 	if (console_blanked)
3960 		unblank_screen();
3961 	else if (blankinterval) {
3962 		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3963 		blank_state = blank_normal_wait;
3964 	}
3965 }
3966 
3967 /*
3968  *	Palettes
3969  */
3970 
3971 static void set_palette(struct vc_data *vc)
3972 {
3973 	WARN_CONSOLE_UNLOCKED();
3974 
3975 	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
3976 		vc->vc_sw->con_set_palette(vc, color_table);
3977 }
3978 
3979 /*
3980  * Load palette into the DAC registers. arg points to a colour
3981  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
3982  */
3983 
3984 int con_set_cmap(unsigned char __user *arg)
3985 {
3986 	int i, j, k;
3987 	unsigned char colormap[3*16];
3988 
3989 	if (copy_from_user(colormap, arg, sizeof(colormap)))
3990 		return -EFAULT;
3991 
3992 	console_lock();
3993 	for (i = k = 0; i < 16; i++) {
3994 		default_red[i] = colormap[k++];
3995 		default_grn[i] = colormap[k++];
3996 		default_blu[i] = colormap[k++];
3997 	}
3998 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
3999 		if (!vc_cons_allocated(i))
4000 			continue;
4001 		for (j = k = 0; j < 16; j++) {
4002 			vc_cons[i].d->vc_palette[k++] = default_red[j];
4003 			vc_cons[i].d->vc_palette[k++] = default_grn[j];
4004 			vc_cons[i].d->vc_palette[k++] = default_blu[j];
4005 		}
4006 		set_palette(vc_cons[i].d);
4007 	}
4008 	console_unlock();
4009 
4010 	return 0;
4011 }
4012 
4013 int con_get_cmap(unsigned char __user *arg)
4014 {
4015 	int i, k;
4016 	unsigned char colormap[3*16];
4017 
4018 	console_lock();
4019 	for (i = k = 0; i < 16; i++) {
4020 		colormap[k++] = default_red[i];
4021 		colormap[k++] = default_grn[i];
4022 		colormap[k++] = default_blu[i];
4023 	}
4024 	console_unlock();
4025 
4026 	if (copy_to_user(arg, colormap, sizeof(colormap)))
4027 		return -EFAULT;
4028 
4029 	return 0;
4030 }
4031 
4032 void reset_palette(struct vc_data *vc)
4033 {
4034 	int j, k;
4035 	for (j=k=0; j<16; j++) {
4036 		vc->vc_palette[k++] = default_red[j];
4037 		vc->vc_palette[k++] = default_grn[j];
4038 		vc->vc_palette[k++] = default_blu[j];
4039 	}
4040 	set_palette(vc);
4041 }
4042 
4043 /*
4044  *  Font switching
4045  *
4046  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4047  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4048  *  depending on width) reserved for each character which is kinda wasty, but
4049  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4050  *  is up to the actual low-level console-driver convert data into its favorite
4051  *  format (maybe we should add a `fontoffset' field to the `display'
4052  *  structure so we won't have to convert the fontdata all the time.
4053  *  /Jes
4054  */
4055 
4056 #define max_font_size 65536
4057 
4058 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4059 {
4060 	struct console_font font;
4061 	int rc = -EINVAL;
4062 	int c;
4063 
4064 	if (op->data) {
4065 		font.data = kmalloc(max_font_size, GFP_KERNEL);
4066 		if (!font.data)
4067 			return -ENOMEM;
4068 	} else
4069 		font.data = NULL;
4070 
4071 	console_lock();
4072 	if (vc->vc_mode != KD_TEXT)
4073 		rc = -EINVAL;
4074 	else if (vc->vc_sw->con_font_get)
4075 		rc = vc->vc_sw->con_font_get(vc, &font);
4076 	else
4077 		rc = -ENOSYS;
4078 	console_unlock();
4079 
4080 	if (rc)
4081 		goto out;
4082 
4083 	c = (font.width+7)/8 * 32 * font.charcount;
4084 
4085 	if (op->data && font.charcount > op->charcount)
4086 		rc = -ENOSPC;
4087 	if (!(op->flags & KD_FONT_FLAG_OLD)) {
4088 		if (font.width > op->width || font.height > op->height)
4089 			rc = -ENOSPC;
4090 	} else {
4091 		if (font.width != 8)
4092 			rc = -EIO;
4093 		else if ((op->height && font.height > op->height) ||
4094 			 font.height > 32)
4095 			rc = -ENOSPC;
4096 	}
4097 	if (rc)
4098 		goto out;
4099 
4100 	op->height = font.height;
4101 	op->width = font.width;
4102 	op->charcount = font.charcount;
4103 
4104 	if (op->data && copy_to_user(op->data, font.data, c))
4105 		rc = -EFAULT;
4106 
4107 out:
4108 	kfree(font.data);
4109 	return rc;
4110 }
4111 
4112 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4113 {
4114 	struct console_font font;
4115 	int rc = -EINVAL;
4116 	int size;
4117 
4118 	if (vc->vc_mode != KD_TEXT)
4119 		return -EINVAL;
4120 	if (!op->data)
4121 		return -EINVAL;
4122 	if (op->charcount > 512)
4123 		return -EINVAL;
4124 	if (!op->height) {		/* Need to guess font height [compat] */
4125 		int h, i;
4126 		u8 __user *charmap = op->data;
4127 		u8 tmp;
4128 
4129 		/* If from KDFONTOP ioctl, don't allow things which can be done in userland,
4130 		   so that we can get rid of this soon */
4131 		if (!(op->flags & KD_FONT_FLAG_OLD))
4132 			return -EINVAL;
4133 		for (h = 32; h > 0; h--)
4134 			for (i = 0; i < op->charcount; i++) {
4135 				if (get_user(tmp, &charmap[32*i+h-1]))
4136 					return -EFAULT;
4137 				if (tmp)
4138 					goto nonzero;
4139 			}
4140 		return -EINVAL;
4141 	nonzero:
4142 		op->height = h;
4143 	}
4144 	if (op->width <= 0 || op->width > 32 || op->height > 32)
4145 		return -EINVAL;
4146 	size = (op->width+7)/8 * 32 * op->charcount;
4147 	if (size > max_font_size)
4148 		return -ENOSPC;
4149 	font.charcount = op->charcount;
4150 	font.height = op->height;
4151 	font.width = op->width;
4152 	font.data = memdup_user(op->data, size);
4153 	if (IS_ERR(font.data))
4154 		return PTR_ERR(font.data);
4155 	console_lock();
4156 	if (vc->vc_mode != KD_TEXT)
4157 		rc = -EINVAL;
4158 	else if (vc->vc_sw->con_font_set)
4159 		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4160 	else
4161 		rc = -ENOSYS;
4162 	console_unlock();
4163 	kfree(font.data);
4164 	return rc;
4165 }
4166 
4167 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4168 {
4169 	struct console_font font = {.width = op->width, .height = op->height};
4170 	char name[MAX_FONT_NAME];
4171 	char *s = name;
4172 	int rc;
4173 
4174 
4175 	if (!op->data)
4176 		s = NULL;
4177 	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4178 		return -EFAULT;
4179 	else
4180 		name[MAX_FONT_NAME - 1] = 0;
4181 
4182 	console_lock();
4183 	if (vc->vc_mode != KD_TEXT) {
4184 		console_unlock();
4185 		return -EINVAL;
4186 	}
4187 	if (vc->vc_sw->con_font_default)
4188 		rc = vc->vc_sw->con_font_default(vc, &font, s);
4189 	else
4190 		rc = -ENOSYS;
4191 	console_unlock();
4192 	if (!rc) {
4193 		op->width = font.width;
4194 		op->height = font.height;
4195 	}
4196 	return rc;
4197 }
4198 
4199 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4200 {
4201 	int con = op->height;
4202 	int rc;
4203 
4204 
4205 	console_lock();
4206 	if (vc->vc_mode != KD_TEXT)
4207 		rc = -EINVAL;
4208 	else if (!vc->vc_sw->con_font_copy)
4209 		rc = -ENOSYS;
4210 	else if (con < 0 || !vc_cons_allocated(con))
4211 		rc = -ENOTTY;
4212 	else if (con == vc->vc_num)	/* nothing to do */
4213 		rc = 0;
4214 	else
4215 		rc = vc->vc_sw->con_font_copy(vc, con);
4216 	console_unlock();
4217 	return rc;
4218 }
4219 
4220 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4221 {
4222 	switch (op->op) {
4223 	case KD_FONT_OP_SET:
4224 		return con_font_set(vc, op);
4225 	case KD_FONT_OP_GET:
4226 		return con_font_get(vc, op);
4227 	case KD_FONT_OP_SET_DEFAULT:
4228 		return con_font_default(vc, op);
4229 	case KD_FONT_OP_COPY:
4230 		return con_font_copy(vc, op);
4231 	}
4232 	return -ENOSYS;
4233 }
4234 
4235 /*
4236  *	Interface exported to selection and vcs.
4237  */
4238 
4239 /* used by selection */
4240 u16 screen_glyph(struct vc_data *vc, int offset)
4241 {
4242 	u16 w = scr_readw(screenpos(vc, offset, 1));
4243 	u16 c = w & 0xff;
4244 
4245 	if (w & vc->vc_hi_font_mask)
4246 		c |= 0x100;
4247 	return c;
4248 }
4249 EXPORT_SYMBOL_GPL(screen_glyph);
4250 
4251 /* used by vcs - note the word offset */
4252 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4253 {
4254 	return screenpos(vc, 2 * w_offset, viewed);
4255 }
4256 EXPORT_SYMBOL_GPL(screen_pos);
4257 
4258 void getconsxy(struct vc_data *vc, unsigned char *p)
4259 {
4260 	p[0] = vc->vc_x;
4261 	p[1] = vc->vc_y;
4262 }
4263 
4264 void putconsxy(struct vc_data *vc, unsigned char *p)
4265 {
4266 	hide_cursor(vc);
4267 	gotoxy(vc, p[0], p[1]);
4268 	set_cursor(vc);
4269 }
4270 
4271 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4272 {
4273 	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4274 		return softcursor_original;
4275 	return scr_readw(org);
4276 }
4277 
4278 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4279 {
4280 	scr_writew(val, org);
4281 	if ((unsigned long)org == vc->vc_pos) {
4282 		softcursor_original = -1;
4283 		add_softcursor(vc);
4284 	}
4285 }
4286 
4287 void vcs_scr_updated(struct vc_data *vc)
4288 {
4289 	notify_update(vc);
4290 }
4291 
4292 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4293 		unsigned int rolled_over, void *base, unsigned int size)
4294 {
4295 	unsigned long ubase = (unsigned long)base;
4296 	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4297 	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4298 	ptrdiff_t origin = (void *)c->vc_origin - base;
4299 	int margin = c->vc_size_row * 4;
4300 	int from, wrap, from_off, avail;
4301 
4302 	/* Turn scrollback off */
4303 	if (!lines) {
4304 		c->vc_visible_origin = c->vc_origin;
4305 		return;
4306 	}
4307 
4308 	/* Do we have already enough to allow jumping from 0 to the end? */
4309 	if (rolled_over > scr_end + margin) {
4310 		from = scr_end;
4311 		wrap = rolled_over + c->vc_size_row;
4312 	} else {
4313 		from = 0;
4314 		wrap = size;
4315 	}
4316 
4317 	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4318 	avail = (origin - from + wrap) % wrap;
4319 
4320 	/* Only a little piece would be left? Show all incl. the piece! */
4321 	if (avail < 2 * margin)
4322 		margin = 0;
4323 	if (from_off < margin)
4324 		from_off = 0;
4325 	if (from_off > avail - margin)
4326 		from_off = avail;
4327 
4328 	c->vc_visible_origin = ubase + (from + from_off) % wrap;
4329 }
4330 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4331 
4332 /*
4333  *	Visible symbols for modules
4334  */
4335 
4336 EXPORT_SYMBOL(color_table);
4337 EXPORT_SYMBOL(default_red);
4338 EXPORT_SYMBOL(default_grn);
4339 EXPORT_SYMBOL(default_blu);
4340 EXPORT_SYMBOL(update_region);
4341 EXPORT_SYMBOL(redraw_screen);
4342 EXPORT_SYMBOL(vc_resize);
4343 EXPORT_SYMBOL(fg_console);
4344 EXPORT_SYMBOL(console_blank_hook);
4345 EXPORT_SYMBOL(console_blanked);
4346 EXPORT_SYMBOL(vc_cons);
4347 EXPORT_SYMBOL(global_cursor_default);
4348 #ifndef VT_SINGLE_DRIVER
4349 EXPORT_SYMBOL(give_up_console);
4350 #endif
4351