drivers/tty/vt/vt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright (C) 1991, 1992  Linus Torvalds
   4  */
   5
   6 /*
   7  * Hopefully this will be a rather complete VT102 implementation.
   8  *
   9  * Beeping thanks to John T Kohl.
  10  *
  11  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
  12  *   Chars, and VT100 enhancements by Peter MacDonald.
  13  *
  14  * Copy and paste function by Andrew Haylett,
  15  *   some enhancements by Alessandro Rubini.
  16  *
  17  * Code to check for different video-cards mostly by Galen Hunt,
  18  * <g-hunt@ee.utah.edu>
  19  *
  20  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
  21  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
  22  *
  23  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
  24  * Resizing of consoles, aeb, 940926
  25  *
  26  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
  27  * <poe@daimi.aau.dk>
  28  *
  29  * User-defined bell sound, new setterm control sequences and printk
  30  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
  31  *
  32  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
  33  *
  34  * Merge with the abstract console driver by Geert Uytterhoeven
  35  * <geert@linux-m68k.org>, Jan 1997.
  36  *
  37  *   Original m68k console driver modifications by
  38  *
  39  *     - Arno Griffioen <arno@usn.nl>
  40  *     - David Carter <carter@cs.bris.ac.uk>
  41  *
  42  *   The abstract console driver provides a generic interface for a text
  43  *   console. It supports VGA text mode, frame buffer based graphical consoles
  44  *   and special graphics processors that are only accessible through some
  45  *   registers (e.g. a TMS340x0 GSP).
  46  *
  47  *   The interface to the hardware is specified using a special structure
  48  *   (struct consw) which contains function pointers to console operations
  49  *   (see <linux/console.h> for more information).
  50  *
  51  * Support for changeable cursor shape
  52  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
  53  *
  54  * Ported to i386 and con_scrolldelta fixed
  55  * by Emmanuel Marty <core@ggi-project.org>, April 1998
  56  *
  57  * Resurrected character buffers in videoram plus lots of other trickery
  58  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
  59  *
  60  * Removed old-style timers, introduced console_timer, made timer
  61  * deletion SMP-safe.  17Jun00, Andrew Morton
  62  *
  63  * Removed console_lock, enabled interrupts across all console operations
  64  * 13 March 2001, Andrew Morton
  65  *
  66  * Fixed UTF-8 mode so alternate charset modes always work according
  67  * to control sequences interpreted in do_con_trol function
  68  * preserving backward VT100 semigraphics compatibility,
  69  * malformed UTF sequences represented as sequences of replacement glyphs,
  70  * original codes or '?' as a last resort if replacement glyph is undefined
  71  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
  72  */
  73
  74 #include <linux/module.h>
  75 #include <linux/types.h>
  76 #include <linux/sched/signal.h>
  77 #include <linux/tty.h>
  78 #include <linux/tty_flip.h>
  79 #include <linux/kernel.h>
  80 #include <linux/string.h>
  81 #include <linux/errno.h>
  82 #include <linux/kd.h>
  83 #include <linux/slab.h>
  84 #include <linux/vmalloc.h>
  85 #include <linux/major.h>
  86 #include <linux/mm.h>
  87 #include <linux/console.h>
  88 #include <linux/init.h>
  89 #include <linux/mutex.h>
  90 #include <linux/vt_kern.h>
  91 #include <linux/selection.h>
  92 #include <linux/tiocl.h>
  93 #include <linux/kbd_kern.h>
  94 #include <linux/consolemap.h>
  95 #include <linux/timer.h>
  96 #include <linux/interrupt.h>
  97 #include <linux/workqueue.h>
  98 #include <linux/pm.h>
  99 #include <linux/font.h>
 100 #include <linux/bitops.h>
 101 #include <linux/notifier.h>
 102 #include <linux/device.h>
 103 #include <linux/io.h>
 104 #include <linux/uaccess.h>
 105 #include <linux/kdb.h>
 106 #include <linux/ctype.h>
 107 #include <linux/bsearch.h>
 108 #include <linux/gcd.h>
 109
 110 #define MAX_NR_CON_DRIVER 16
 111
 112 #define CON_DRIVER_FLAG_MODULE 1
 113 #define CON_DRIVER_FLAG_INIT   2
 114 #define CON_DRIVER_FLAG_ATTR   4
 115 #define CON_DRIVER_FLAG_ZOMBIE 8
 116
 117 struct con_driver {
 118         const struct consw *con;
 119         const char *desc;
 120         struct device *dev;
 121         int node;
 122         int first;
 123         int last;
 124         int flag;
 125 };
 126
 127 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
 128 const struct consw *conswitchp;
 129
 130 /* A bitmap for codes <32. A bit of 1 indicates that the code
 131  * corresponding to that bit number invokes some special action
 132  * (such as cursor movement) and should not be displayed as a
 133  * glyph unless the disp_ctrl mode is explicitly enabled.
 134  */
 135 #define CTRL_ACTION 0x0d00ff81
 136 #define CTRL_ALWAYS 0x0800f501  /* Cannot be overridden by disp_ctrl */
 137
 138 /*
 139  * Here is the default bell parameters: 750HZ, 1/8th of a second
 140  */
 141 #define DEFAULT_BELL_PITCH      750
 142 #define DEFAULT_BELL_DURATION   (HZ/8)
 143 #define DEFAULT_CURSOR_BLINK_MS 200
 144
 145 struct vc vc_cons [MAX_NR_CONSOLES];
 146
 147 #ifndef VT_SINGLE_DRIVER
 148 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
 149 #endif
 150
 151 static int con_open(struct tty_struct *, struct file *);
 152 static void vc_init(struct vc_data *vc, unsigned int rows,
 153                     unsigned int cols, int do_clear);
 154 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
 155 static void save_cur(struct vc_data *vc);
 156 static void reset_terminal(struct vc_data *vc, int do_clear);
 157 static void con_flush_chars(struct tty_struct *tty);
 158 static int set_vesa_blanking(char __user *p);
 159 static void set_cursor(struct vc_data *vc);
 160 static void hide_cursor(struct vc_data *vc);
 161 static void console_callback(struct work_struct *ignored);
 162 static void con_driver_unregister_callback(struct work_struct *ignored);
 163 static void blank_screen_t(struct timer_list *unused);
 164 static void set_palette(struct vc_data *vc);
 165
 166 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 167
 168 static int printable;           /* Is console ready for printing? */
 169 int default_utf8 = true;
 170 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 171 int global_cursor_default = -1;
 172 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
 173
 174 static int cur_default = CUR_DEFAULT;
 175 module_param(cur_default, int, S_IRUGO | S_IWUSR);
 176
 177 /*
 178  * ignore_poke: don't unblank the screen when things are typed.  This is
 179  * mainly for the privacy of braille terminal users.
 180  */
 181 static int ignore_poke;
 182
 183 int do_poke_blanked_console;
 184 int console_blanked;
 185
 186 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
 187 static int vesa_off_interval;
 188 static int blankinterval;
 189 core_param(consoleblank, blankinterval, int, 0444);
 190
 191 static DECLARE_WORK(console_work, console_callback);
 192 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
 193
 194 /*
 195  * fg_console is the current virtual console,
 196  * last_console is the last used one,
 197  * want_console is the console we want to switch to,
 198  * saved_* variants are for save/restore around kernel debugger enter/leave
 199  */
 200 int fg_console;
 201 int last_console;
 202 int want_console = -1;
 203 static int saved_fg_console;
 204 static int saved_last_console;
 205 static int saved_want_console;
 206 static int saved_vc_mode;
 207 static int saved_console_blanked;
 208
 209 /*
 210  * For each existing display, we have a pointer to console currently visible
 211  * on that display, allowing consoles other than fg_console to be refreshed
 212  * appropriately. Unless the low-level driver supplies its own display_fg
 213  * variable, we use this one for the "master display".
 214  */
 215 static struct vc_data *master_display_fg;
 216
 217 /*
 218  * Unfortunately, we need to delay tty echo when we're currently writing to the
 219  * console since the code is (and always was) not re-entrant, so we schedule
 220  * all flip requests to process context with schedule-task() and run it from
 221  * console_callback().
 222  */
 223
 224 /*
 225  * For the same reason, we defer scrollback to the console callback.
 226  */
 227 static int scrollback_delta;
 228
 229 /*
 230  * Hook so that the power management routines can (un)blank
 231  * the console on our behalf.
 232  */
 233 int (*console_blank_hook)(int);
 234
 235 static DEFINE_TIMER(console_timer, blank_screen_t);
 236 static int blank_state;
 237 static int blank_timer_expired;
 238 enum {
 239         blank_off = 0,
 240         blank_normal_wait,
 241         blank_vesa_wait,
 242 };
 243
 244 /*
 245  * /sys/class/tty/tty0/
 246  *
 247  * the attribute 'active' contains the name of the current vc
 248  * console and it supports poll() to detect vc switches
 249  */
 250 static struct device *tty0dev;
 251
 252 /*
 253  * Notifier list for console events.
 254  */
 255 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
 256
 257 int register_vt_notifier(struct notifier_block *nb)
 258 {
 259         return atomic_notifier_chain_register(&vt_notifier_list, nb);
 260 }
 261 EXPORT_SYMBOL_GPL(register_vt_notifier);
 262
 263 int unregister_vt_notifier(struct notifier_block *nb)
 264 {
 265         return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
 266 }
 267 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
 268
 269 static void notify_write(struct vc_data *vc, unsigned int unicode)
 270 {
 271         struct vt_notifier_param param = { .vc = vc, .c = unicode };
 272         atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
 273 }
 274
 275 static void notify_update(struct vc_data *vc)
 276 {
 277         struct vt_notifier_param param = { .vc = vc };
 278         atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
 279 }
 280 /*
 281  *      Low-Level Functions
 282  */
 283
 284 static inline bool con_is_fg(const struct vc_data *vc)
 285 {
 286         return vc->vc_num == fg_console;
 287 }
 288
 289 static inline bool con_should_update(const struct vc_data *vc)
 290 {
 291         return con_is_visible(vc) && !console_blanked;
 292 }
 293
 294 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
 295 {
 296         unsigned short *p;
 297
 298         if (!viewed)
 299                 p = (unsigned short *)(vc->vc_origin + offset);
 300         else if (!vc->vc_sw->con_screen_pos)
 301                 p = (unsigned short *)(vc->vc_visible_origin + offset);
 302         else
 303                 p = vc->vc_sw->con_screen_pos(vc, offset);
 304         return p;
 305 }
 306
 307 /* Called  from the keyboard irq path.. */
 308 static inline void scrolldelta(int lines)
 309 {
 310         /* FIXME */
 311         /* scrolldelta needs some kind of consistency lock, but the BKL was
 312            and still is not protecting versus the scheduled back end */
 313         scrollback_delta += lines;
 314         schedule_console_callback();
 315 }
 316
 317 void schedule_console_callback(void)
 318 {
 319         schedule_work(&console_work);
 320 }
 321
 322 /*
 323  * Code to manage unicode-based screen buffers
 324  */
 325
 326 #ifdef NO_VC_UNI_SCREEN
 327 /* this disables and optimizes related code away at compile time */
 328 #define get_vc_uniscr(vc) NULL
 329 #else
 330 #define get_vc_uniscr(vc) vc->vc_uni_screen
 331 #endif
 332
 333 #define VC_UNI_SCREEN_DEBUG 0
 334
 335 typedef uint32_t char32_t;
 336
 337 /*
 338  * Our screen buffer is preceded by an array of line pointers so that
 339  * scrolling only implies some pointer shuffling.
 340  */
 341 struct uni_screen {
 342         char32_t *lines[0];
 343 };
 344
 345 static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
 346 {
 347         struct uni_screen *uniscr;
 348         void *p;
 349         unsigned int memsize, i;
 350
 351         /* allocate everything in one go */
 352         memsize = cols * rows * sizeof(char32_t);
 353         memsize += rows * sizeof(char32_t *);
 354         p = vzalloc(memsize);
 355         if (!p)
 356                 return NULL;
 357
 358         /* initial line pointers */
 359         uniscr = p;
 360         p = uniscr->lines + rows;
 361         for (i = 0; i < rows; i++) {
 362                 uniscr->lines[i] = p;
 363                 p += cols * sizeof(char32_t);
 364         }
 365         return uniscr;
 366 }
 367
 368 static void vc_uniscr_free(struct uni_screen *uniscr)
 369 {
 370         vfree(uniscr);
 371 }
 372
 373 static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
 374 {
 375         vc_uniscr_free(vc->vc_uni_screen);
 376         vc->vc_uni_screen = new_uniscr;
 377 }
 378
 379 static void vc_uniscr_putc(struct vc_data *vc, char32_t uc)
 380 {
 381         struct uni_screen *uniscr = get_vc_uniscr(vc);
 382
 383         if (uniscr)
 384                 uniscr->lines[vc->vc_y][vc->vc_x] = uc;
 385 }
 386
 387 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
 388 {
 389         struct uni_screen *uniscr = get_vc_uniscr(vc);
 390
 391         if (uniscr) {
 392                 char32_t *ln = uniscr->lines[vc->vc_y];
 393                 unsigned int x = vc->vc_x, cols = vc->vc_cols;
 394
 395                 memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
 396                 memset32(&ln[x], ' ', nr);
 397         }
 398 }
 399
 400 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
 401 {
 402         struct uni_screen *uniscr = get_vc_uniscr(vc);
 403
 404         if (uniscr) {
 405                 char32_t *ln = uniscr->lines[vc->vc_y];
 406                 unsigned int x = vc->vc_x, cols = vc->vc_cols;
 407
 408                 memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
 409                 memset32(&ln[cols - nr], ' ', nr);
 410         }
 411 }
 412
 413 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
 414                                  unsigned int nr)
 415 {
 416         struct uni_screen *uniscr = get_vc_uniscr(vc);
 417
 418         if (uniscr) {
 419                 char32_t *ln = uniscr->lines[vc->vc_y];
 420
 421                 memset32(&ln[x], ' ', nr);
 422         }
 423 }
 424
 425 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
 426                                   unsigned int nr)
 427 {
 428         struct uni_screen *uniscr = get_vc_uniscr(vc);
 429
 430         if (uniscr) {
 431                 unsigned int cols = vc->vc_cols;
 432
 433                 while (nr--)
 434                         memset32(uniscr->lines[y++], ' ', cols);
 435         }
 436 }
 437
 438 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 439                              enum con_scroll dir, unsigned int nr)
 440 {
 441         struct uni_screen *uniscr = get_vc_uniscr(vc);
 442
 443         if (uniscr) {
 444                 unsigned int i, j, k, sz, d, clear;
 445
 446                 sz = b - t;
 447                 clear = b - nr;
 448                 d = nr;
 449                 if (dir == SM_DOWN) {
 450                         clear = t;
 451                         d = sz - nr;
 452                 }
 453                 for (i = 0; i < gcd(d, sz); i++) {
 454                         char32_t *tmp = uniscr->lines[t + i];
 455                         j = i;
 456                         while (1) {
 457                                 k = j + d;
 458                                 if (k >= sz)
 459                                         k -= sz;
 460                                 if (k == i)
 461                                         break;
 462                                 uniscr->lines[t + j] = uniscr->lines[t + k];
 463                                 j = k;
 464                         }
 465                         uniscr->lines[t + j] = tmp;
 466                 }
 467                 vc_uniscr_clear_lines(vc, clear, nr);
 468         }
 469 }
 470
 471 static void vc_uniscr_copy_area(struct uni_screen *dst,
 472                                 unsigned int dst_cols,
 473                                 unsigned int dst_rows,
 474                                 struct uni_screen *src,
 475                                 unsigned int src_cols,
 476                                 unsigned int src_top_row,
 477                                 unsigned int src_bot_row)
 478 {
 479         unsigned int dst_row = 0;
 480
 481         if (!dst)
 482                 return;
 483
 484         while (src_top_row < src_bot_row) {
 485                 char32_t *src_line = src->lines[src_top_row];
 486                 char32_t *dst_line = dst->lines[dst_row];
 487
 488                 memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
 489                 if (dst_cols - src_cols)
 490                         memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
 491                 src_top_row++;
 492                 dst_row++;
 493         }
 494         while (dst_row < dst_rows) {
 495                 char32_t *dst_line = dst->lines[dst_row];
 496
 497                 memset32(dst_line, ' ', dst_cols);
 498                 dst_row++;
 499         }
 500 }
 501
 502 /*
 503  * Called from vcs_read() to make sure unicode screen retrieval is possible.
 504  * This will initialize the unicode screen buffer if not already done.
 505  * This returns 0 if OK, or a negative error code otherwise.
 506  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
 507  */
 508 int vc_uniscr_check(struct vc_data *vc)
 509 {
 510         struct uni_screen *uniscr;
 511         unsigned short *p;
 512         int x, y, mask;
 513
 514         if (__is_defined(NO_VC_UNI_SCREEN))
 515                 return -EOPNOTSUPP;
 516
 517         WARN_CONSOLE_UNLOCKED();
 518
 519         if (!vc->vc_utf)
 520                 return -ENODATA;
 521
 522         if (vc->vc_uni_screen)
 523                 return 0;
 524
 525         uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
 526         if (!uniscr)
 527                 return -ENOMEM;
 528
 529         /*
 530          * Let's populate it initially with (imperfect) reverse translation.
 531          * This is the next best thing we can do short of having it enabled
 532          * from the start even when no users rely on this functionality. True
 533          * unicode content will be available after a complete screen refresh.
 534          */
 535         p = (unsigned short *)vc->vc_origin;
 536         mask = vc->vc_hi_font_mask | 0xff;
 537         for (y = 0; y < vc->vc_rows; y++) {
 538                 char32_t *line = uniscr->lines[y];
 539                 for (x = 0; x < vc->vc_cols; x++) {
 540                         u16 glyph = scr_readw(p++) & mask;
 541                         line[x] = inverse_translate(vc, glyph, true);
 542                 }
 543         }
 544
 545         vc->vc_uni_screen = uniscr;
 546         return 0;
 547 }
 548
 549 /*
 550  * Called from vcs_read() to get the unicode data from the screen.
 551  * This must be preceded by a successful call to vc_uniscr_check() once
 552  * the console lock has been taken.
 553  */
 554 void vc_uniscr_copy_line(struct vc_data *vc, void *dest, int viewed,
 555                          unsigned int row, unsigned int col, unsigned int nr)
 556 {
 557         struct uni_screen *uniscr = get_vc_uniscr(vc);
 558         int offset = row * vc->vc_size_row + col * 2;
 559         unsigned long pos;
 560
 561         BUG_ON(!uniscr);
 562
 563         pos = (unsigned long)screenpos(vc, offset, viewed);
 564         if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
 565                 /*
 566                  * Desired position falls in the main screen buffer.
 567                  * However the actual row/col might be different if
 568                  * scrollback is active.
 569                  */
 570                 row = (pos - vc->vc_origin) / vc->vc_size_row;
 571                 col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
 572                 memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t));
 573         } else {
 574                 /*
 575                  * Scrollback is active. For now let's simply backtranslate
 576                  * the screen glyphs until the unicode screen buffer does
 577                  * synchronize with console display drivers for a scrollback
 578                  * buffer of its own.
 579                  */
 580                 u16 *p = (u16 *)pos;
 581                 int mask = vc->vc_hi_font_mask | 0xff;
 582                 char32_t *uni_buf = dest;
 583                 while (nr--) {
 584                         u16 glyph = scr_readw(p++) & mask;
 585                         *uni_buf++ = inverse_translate(vc, glyph, true);
 586                 }
 587         }
 588 }
 589
 590 /* this is for validation and debugging only */
 591 static void vc_uniscr_debug_check(struct vc_data *vc)
 592 {
 593         struct uni_screen *uniscr = get_vc_uniscr(vc);
 594         unsigned short *p;
 595         int x, y, mask;
 596
 597         if (!VC_UNI_SCREEN_DEBUG || !uniscr)
 598                 return;
 599
 600         WARN_CONSOLE_UNLOCKED();
 601
 602         /*
 603          * Make sure our unicode screen translates into the same glyphs
 604          * as the actual screen. This is brutal indeed.
 605          */
 606         p = (unsigned short *)vc->vc_origin;
 607         mask = vc->vc_hi_font_mask | 0xff;
 608         for (y = 0; y < vc->vc_rows; y++) {
 609                 char32_t *line = uniscr->lines[y];
 610                 for (x = 0; x < vc->vc_cols; x++) {
 611                         u16 glyph = scr_readw(p++) & mask;
 612                         char32_t uc = line[x];
 613                         int tc = conv_uni_to_pc(vc, uc);
 614                         if (tc == -4)
 615                                 tc = conv_uni_to_pc(vc, 0xfffd);
 616                         if (tc == -4)
 617                                 tc = conv_uni_to_pc(vc, '?');
 618                         if (tc != glyph)
 619                                 pr_err_ratelimited(
 620                                         "%s: mismatch at %d,%d: glyph=%#x tc=%#x\n",
 621                                         __func__, x, y, glyph, tc);
 622                 }
 623         }
 624 }
 625
 626
 627 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 628                 enum con_scroll dir, unsigned int nr)
 629 {
 630         u16 *clear, *d, *s;
 631
 632         if (t + nr >= b)
 633                 nr = b - t - 1;
 634         if (b > vc->vc_rows || t >= b || nr < 1)
 635                 return;
 636         vc_uniscr_scroll(vc, t, b, dir, nr);
 637         if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
 638                 return;
 639
 640         s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
 641         d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
 642
 643         if (dir == SM_UP) {
 644                 clear = s + (b - t - nr) * vc->vc_cols;
 645                 swap(s, d);
 646         }
 647         scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
 648         scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
 649 }
 650
 651 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 652 {
 653         unsigned int xx, yy, offset;
 654         u16 *p;
 655
 656         p = (u16 *) start;
 657         if (!vc->vc_sw->con_getxy) {
 658                 offset = (start - vc->vc_origin) / 2;
 659                 xx = offset % vc->vc_cols;
 660                 yy = offset / vc->vc_cols;
 661         } else {
 662                 int nxx, nyy;
 663                 start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
 664                 xx = nxx; yy = nyy;
 665         }
 666         for(;;) {
 667                 u16 attrib = scr_readw(p) & 0xff00;
 668                 int startx = xx;
 669                 u16 *q = p;
 670                 while (xx < vc->vc_cols && count) {
 671                         if (attrib != (scr_readw(p) & 0xff00)) {
 672                                 if (p > q)
 673                                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 674                                 startx = xx;
 675                                 q = p;
 676                                 attrib = scr_readw(p) & 0xff00;
 677                         }
 678                         p++;
 679                         xx++;
 680                         count--;
 681                 }
 682                 if (p > q)
 683                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 684                 if (!count)
 685                         break;
 686                 xx = 0;
 687                 yy++;
 688                 if (vc->vc_sw->con_getxy) {
 689                         p = (u16 *)start;
 690                         start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
 691                 }
 692         }
 693 }
 694
 695 void update_region(struct vc_data *vc, unsigned long start, int count)
 696 {
 697         WARN_CONSOLE_UNLOCKED();
 698
 699         if (con_should_update(vc)) {
 700                 hide_cursor(vc);
 701                 do_update_region(vc, start, count);
 702                 set_cursor(vc);
 703         }
 704 }
 705
 706 /* Structure of attributes is hardware-dependent */
 707
 708 static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
 709     u8 _underline, u8 _reverse, u8 _italic)
 710 {
 711         if (vc->vc_sw->con_build_attr)
 712                 return vc->vc_sw->con_build_attr(vc, _color, _intensity,
 713                        _blink, _underline, _reverse, _italic);
 714
 715 /*
 716  * ++roman: I completely changed the attribute format for monochrome
 717  * mode (!can_do_color). The formerly used MDA (monochrome display
 718  * adapter) format didn't allow the combination of certain effects.
 719  * Now the attribute is just a bit vector:
 720  *  Bit 0..1: intensity (0..2)
 721  *  Bit 2   : underline
 722  *  Bit 3   : reverse
 723  *  Bit 7   : blink
 724  */
 725         {
 726         u8 a = _color;
 727         if (!vc->vc_can_do_color)
 728                 return _intensity |
 729                        (_italic ? 2 : 0) |
 730                        (_underline ? 4 : 0) |
 731                        (_reverse ? 8 : 0) |
 732                        (_blink ? 0x80 : 0);
 733         if (_italic)
 734                 a = (a & 0xF0) | vc->vc_itcolor;
 735         else if (_underline)
 736                 a = (a & 0xf0) | vc->vc_ulcolor;
 737         else if (_intensity == 0)
 738                 a = (a & 0xf0) | vc->vc_halfcolor;
 739         if (_reverse)
 740                 a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
 741         if (_blink)
 742                 a ^= 0x80;
 743         if (_intensity == 2)
 744                 a ^= 0x08;
 745         if (vc->vc_hi_font_mask == 0x100)
 746                 a <<= 1;
 747         return a;
 748         }
 749 }
 750
 751 static void update_attr(struct vc_data *vc)
 752 {
 753         vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
 754                       vc->vc_blink, vc->vc_underline,
 755                       vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
 756         vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
 757 }
 758
 759 /* Note: inverting the screen twice should revert to the original state */
 760 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
 761 {
 762         unsigned short *p;
 763
 764         WARN_CONSOLE_UNLOCKED();
 765
 766         count /= 2;
 767         p = screenpos(vc, offset, viewed);
 768         if (vc->vc_sw->con_invert_region) {
 769                 vc->vc_sw->con_invert_region(vc, p, count);
 770         } else {
 771                 u16 *q = p;
 772                 int cnt = count;
 773                 u16 a;
 774
 775                 if (!vc->vc_can_do_color) {
 776                         while (cnt--) {
 777                             a = scr_readw(q);
 778                             a ^= 0x0800;
 779                             scr_writew(a, q);
 780                             q++;
 781                         }
 782                 } else if (vc->vc_hi_font_mask == 0x100) {
 783                         while (cnt--) {
 784                                 a = scr_readw(q);
 785                                 a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
 786                                 scr_writew(a, q);
 787                                 q++;
 788                         }
 789                 } else {
 790                         while (cnt--) {
 791                                 a = scr_readw(q);
 792                                 a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
 793                                 scr_writew(a, q);
 794                                 q++;
 795                         }
 796                 }
 797         }
 798
 799         if (con_should_update(vc))
 800                 do_update_region(vc, (unsigned long) p, count);
 801         notify_update(vc);
 802 }
 803
 804 /* used by selection: complement pointer position */
 805 void complement_pos(struct vc_data *vc, int offset)
 806 {
 807         static int old_offset = -1;
 808         static unsigned short old;
 809         static unsigned short oldx, oldy;
 810
 811         WARN_CONSOLE_UNLOCKED();
 812
 813         if (old_offset != -1 && old_offset >= 0 &&
 814             old_offset < vc->vc_screenbuf_size) {
 815                 scr_writew(old, screenpos(vc, old_offset, 1));
 816                 if (con_should_update(vc))
 817                         vc->vc_sw->con_putc(vc, old, oldy, oldx);
 818                 notify_update(vc);
 819         }
 820
 821         old_offset = offset;
 822
 823         if (offset != -1 && offset >= 0 &&
 824             offset < vc->vc_screenbuf_size) {
 825                 unsigned short new;
 826                 unsigned short *p;
 827                 p = screenpos(vc, offset, 1);
 828                 old = scr_readw(p);
 829                 new = old ^ vc->vc_complement_mask;
 830                 scr_writew(new, p);
 831                 if (con_should_update(vc)) {
 832                         oldx = (offset >> 1) % vc->vc_cols;
 833                         oldy = (offset >> 1) / vc->vc_cols;
 834                         vc->vc_sw->con_putc(vc, new, oldy, oldx);
 835                 }
 836                 notify_update(vc);
 837         }
 838 }
 839
 840 static void insert_char(struct vc_data *vc, unsigned int nr)
 841 {
 842         unsigned short *p = (unsigned short *) vc->vc_pos;
 843
 844         vc_uniscr_insert(vc, nr);
 845         scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
 846         scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
 847         vc->vc_need_wrap = 0;
 848         if (con_should_update(vc))
 849                 do_update_region(vc, (unsigned long) p,
 850                         vc->vc_cols - vc->vc_x);
 851 }
 852
 853 static void delete_char(struct vc_data *vc, unsigned int nr)
 854 {
 855         unsigned short *p = (unsigned short *) vc->vc_pos;
 856
 857         vc_uniscr_delete(vc, nr);
 858         scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
 859         scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
 860                         nr * 2);
 861         vc->vc_need_wrap = 0;
 862         if (con_should_update(vc))
 863                 do_update_region(vc, (unsigned long) p,
 864                         vc->vc_cols - vc->vc_x);
 865 }
 866
 867 static int softcursor_original = -1;
 868
 869 static void add_softcursor(struct vc_data *vc)
 870 {
 871         int i = scr_readw((u16 *) vc->vc_pos);
 872         u32 type = vc->vc_cursor_type;
 873
 874         if (! (type & 0x10)) return;
 875         if (softcursor_original != -1) return;
 876         softcursor_original = i;
 877         i |= ((type >> 8) & 0xff00 );
 878         i ^= ((type) & 0xff00 );
 879         if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
 880         if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
 881         scr_writew(i, (u16 *) vc->vc_pos);
 882         if (con_should_update(vc))
 883                 vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
 884 }
 885
 886 static void hide_softcursor(struct vc_data *vc)
 887 {
 888         if (softcursor_original != -1) {
 889                 scr_writew(softcursor_original, (u16 *)vc->vc_pos);
 890                 if (con_should_update(vc))
 891                         vc->vc_sw->con_putc(vc, softcursor_original,
 892                                         vc->vc_y, vc->vc_x);
 893                 softcursor_original = -1;
 894         }
 895 }
 896
 897 static void hide_cursor(struct vc_data *vc)
 898 {
 899         if (vc_is_sel(vc))
 900                 clear_selection();
 901
 902         vc->vc_sw->con_cursor(vc, CM_ERASE);
 903         hide_softcursor(vc);
 904 }
 905
 906 static void set_cursor(struct vc_data *vc)
 907 {
 908         if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
 909                 return;
 910         if (vc->vc_deccm) {
 911                 if (vc_is_sel(vc))
 912                         clear_selection();
 913                 add_softcursor(vc);
 914                 if ((vc->vc_cursor_type & 0x0f) != 1)
 915                         vc->vc_sw->con_cursor(vc, CM_DRAW);
 916         } else
 917                 hide_cursor(vc);
 918 }
 919
 920 static void set_origin(struct vc_data *vc)
 921 {
 922         WARN_CONSOLE_UNLOCKED();
 923
 924         if (!con_is_visible(vc) ||
 925             !vc->vc_sw->con_set_origin ||
 926             !vc->vc_sw->con_set_origin(vc))
 927                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
 928         vc->vc_visible_origin = vc->vc_origin;
 929         vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
 930         vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
 931 }
 932
 933 static void save_screen(struct vc_data *vc)
 934 {
 935         WARN_CONSOLE_UNLOCKED();
 936
 937         if (vc->vc_sw->con_save_screen)
 938                 vc->vc_sw->con_save_screen(vc);
 939 }
 940
 941 static void flush_scrollback(struct vc_data *vc)
 942 {
 943         WARN_CONSOLE_UNLOCKED();
 944
 945         set_origin(vc);
 946         if (vc->vc_sw->con_flush_scrollback) {
 947                 vc->vc_sw->con_flush_scrollback(vc);
 948         } else if (con_is_visible(vc)) {
 949                 /*
 950                  * When no con_flush_scrollback method is provided then the
 951                  * legacy way for flushing the scrollback buffer is to use
 952                  * a side effect of the con_switch method. We do it only on
 953                  * the foreground console as background consoles have no
 954                  * scrollback buffers in that case and we obviously don't
 955                  * want to switch to them.
 956                  */
 957                 hide_cursor(vc);
 958                 vc->vc_sw->con_switch(vc);
 959                 set_cursor(vc);
 960         }
 961 }
 962
 963 /*
 964  *      Redrawing of screen
 965  */
 966
 967 void clear_buffer_attributes(struct vc_data *vc)
 968 {
 969         unsigned short *p = (unsigned short *)vc->vc_origin;
 970         int count = vc->vc_screenbuf_size / 2;
 971         int mask = vc->vc_hi_font_mask | 0xff;
 972
 973         for (; count > 0; count--, p++) {
 974                 scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
 975         }
 976 }
 977
 978 void redraw_screen(struct vc_data *vc, int is_switch)
 979 {
 980         int redraw = 0;
 981
 982         WARN_CONSOLE_UNLOCKED();
 983
 984         if (!vc) {
 985                 /* strange ... */
 986                 /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
 987                 return;
 988         }
 989
 990         if (is_switch) {
 991                 struct vc_data *old_vc = vc_cons[fg_console].d;
 992                 if (old_vc == vc)
 993                         return;
 994                 if (!con_is_visible(vc))
 995                         redraw = 1;
 996                 *vc->vc_display_fg = vc;
 997                 fg_console = vc->vc_num;
 998                 hide_cursor(old_vc);
 999                 if (!con_is_visible(old_vc)) {
1000                         save_screen(old_vc);
1001                         set_origin(old_vc);
1002                 }
1003                 if (tty0dev)
1004                         sysfs_notify(&tty0dev->kobj, NULL, "active");
1005         } else {
1006                 hide_cursor(vc);
1007                 redraw = 1;
1008         }
1009
1010         if (redraw) {
1011                 int update;
1012                 int old_was_color = vc->vc_can_do_color;
1013
1014                 set_origin(vc);
1015                 update = vc->vc_sw->con_switch(vc);
1016                 set_palette(vc);
1017                 /*
1018                  * If console changed from mono<->color, the best we can do
1019                  * is to clear the buffer attributes. As it currently stands,
1020                  * rebuilding new attributes from the old buffer is not doable
1021                  * without overly complex code.
1022                  */
1023                 if (old_was_color != vc->vc_can_do_color) {
1024                         update_attr(vc);
1025                         clear_buffer_attributes(vc);
1026                 }
1027
1028                 /* Forcibly update if we're panicing */
1029                 if ((update && vc->vc_mode != KD_GRAPHICS) ||
1030                     vt_force_oops_output(vc))
1031                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1032         }
1033         set_cursor(vc);
1034         if (is_switch) {
1035                 set_leds();
1036                 compute_shiftstate();
1037                 notify_update(vc);
1038         }
1039 }
1040
1041 /*
1042  *      Allocation, freeing and resizing of VTs.
1043  */
1044
1045 int vc_cons_allocated(unsigned int i)
1046 {
1047         return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1048 }
1049
1050 static void visual_init(struct vc_data *vc, int num, int init)
1051 {
1052         /* ++Geert: vc->vc_sw->con_init determines console size */
1053         if (vc->vc_sw)
1054                 module_put(vc->vc_sw->owner);
1055         vc->vc_sw = conswitchp;
1056 #ifndef VT_SINGLE_DRIVER
1057         if (con_driver_map[num])
1058                 vc->vc_sw = con_driver_map[num];
1059 #endif
1060         __module_get(vc->vc_sw->owner);
1061         vc->vc_num = num;
1062         vc->vc_display_fg = &master_display_fg;
1063         if (vc->vc_uni_pagedir_loc)
1064                 con_free_unimap(vc);
1065         vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
1066         vc->vc_uni_pagedir = NULL;
1067         vc->vc_hi_font_mask = 0;
1068         vc->vc_complement_mask = 0;
1069         vc->vc_can_do_color = 0;
1070         vc->vc_panic_force_write = false;
1071         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1072         vc->vc_sw->con_init(vc, init);
1073         if (!vc->vc_complement_mask)
1074                 vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1075         vc->vc_s_complement_mask = vc->vc_complement_mask;
1076         vc->vc_size_row = vc->vc_cols << 1;
1077         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1078 }
1079
1080
1081 static void visual_deinit(struct vc_data *vc)
1082 {
1083         vc->vc_sw->con_deinit(vc);
1084         module_put(vc->vc_sw->owner);
1085 }
1086
1087 static void vc_port_destruct(struct tty_port *port)
1088 {
1089         struct vc_data *vc = container_of(port, struct vc_data, port);
1090
1091         kfree(vc);
1092 }
1093
1094 static const struct tty_port_operations vc_port_ops = {
1095         .destruct = vc_port_destruct,
1096 };
1097
1098 /*
1099  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1100  * [this is to be used together with some user program
1101  * like resize that changes the hardware videomode]
1102  */
1103 #define VC_MAXCOL (32767)
1104 #define VC_MAXROW (32767)
1105
1106 int vc_allocate(unsigned int currcons)  /* return 0 on success */
1107 {
1108         struct vt_notifier_param param;
1109         struct vc_data *vc;
1110         int err;
1111
1112         WARN_CONSOLE_UNLOCKED();
1113
1114         if (currcons >= MAX_NR_CONSOLES)
1115                 return -ENXIO;
1116
1117         if (vc_cons[currcons].d)
1118                 return 0;
1119
1120         /* due to the granularity of kmalloc, we waste some memory here */
1121         /* the alloc is done in two steps, to optimize the common situation
1122            of a 25x80 console (structsize=216, screenbuf_size=4000) */
1123         /* although the numbers above are not valid since long ago, the
1124            point is still up-to-date and the comment still has its value
1125            even if only as a historical artifact.  --mj, July 1998 */
1126         param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1127         if (!vc)
1128                 return -ENOMEM;
1129
1130         vc_cons[currcons].d = vc;
1131         tty_port_init(&vc->port);
1132         vc->port.ops = &vc_port_ops;
1133         INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1134
1135         visual_init(vc, currcons, 1);
1136
1137         if (!*vc->vc_uni_pagedir_loc)
1138                 con_set_default_unimap(vc);
1139
1140         err = -EINVAL;
1141         if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
1142             vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
1143                 goto err_free;
1144         err = -ENOMEM;
1145         vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1146         if (!vc->vc_screenbuf)
1147                 goto err_free;
1148
1149         /* If no drivers have overridden us and the user didn't pass a
1150            boot option, default to displaying the cursor */
1151         if (global_cursor_default == -1)
1152                 global_cursor_default = 1;
1153
1154         vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
1155         vcs_make_sysfs(currcons);
1156         atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1157
1158         return 0;
1159 err_free:
1160         visual_deinit(vc);
1161         kfree(vc);
1162         vc_cons[currcons].d = NULL;
1163         return err;
1164 }
1165
1166 static inline int resize_screen(struct vc_data *vc, int width, int height,
1167                                 int user)
1168 {
1169         /* Resizes the resolution of the display adapater */
1170         int err = 0;
1171
1172         if (vc->vc_sw->con_resize)
1173                 err = vc->vc_sw->con_resize(vc, width, height, user);
1174
1175         return err;
1176 }
1177
1178 /**
1179  *      vc_do_resize    -       resizing method for the tty
1180  *      @tty: tty being resized
1181  *      @real_tty: real tty (different to tty if a pty/tty pair)
1182  *      @vc: virtual console private data
1183  *      @cols: columns
1184  *      @lines: lines
1185  *
1186  *      Resize a virtual console, clipping according to the actual constraints.
1187  *      If the caller passes a tty structure then update the termios winsize
1188  *      information and perform any necessary signal handling.
1189  *
1190  *      Caller must hold the console semaphore. Takes the termios rwsem and
1191  *      ctrl_lock of the tty IFF a tty is passed.
1192  */
1193
1194 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1195                                 unsigned int cols, unsigned int lines)
1196 {
1197         unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1198         unsigned long end;
1199         unsigned int old_rows, old_row_size, first_copied_row;
1200         unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1201         unsigned int user;
1202         unsigned short *oldscreen, *newscreen;
1203         struct uni_screen *new_uniscr = NULL;
1204
1205         WARN_CONSOLE_UNLOCKED();
1206
1207         if (!vc)
1208                 return -ENXIO;
1209
1210         user = vc->vc_resize_user;
1211         vc->vc_resize_user = 0;
1212
1213         if (cols > VC_MAXCOL || lines > VC_MAXROW)
1214                 return -EINVAL;
1215
1216         new_cols = (cols ? cols : vc->vc_cols);
1217         new_rows = (lines ? lines : vc->vc_rows);
1218         new_row_size = new_cols << 1;
1219         new_screen_size = new_row_size * new_rows;
1220
1221         if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) {
1222                 /*
1223                  * This function is being called here to cover the case
1224                  * where the userspace calls the FBIOPUT_VSCREENINFO twice,
1225                  * passing the same fb_var_screeninfo containing the fields
1226                  * yres/xres equal to a number non-multiple of vc_font.height
1227                  * and yres_virtual/xres_virtual equal to number lesser than the
1228                  * vc_font.height and yres/xres.
1229                  * In the second call, the struct fb_var_screeninfo isn't
1230                  * being modified by the underlying driver because of the
1231                  * if above, and this causes the fbcon_display->vrows to become
1232                  * negative and it eventually leads to out-of-bound
1233                  * access by the imageblit function.
1234                  * To give the correct values to the struct and to not have
1235                  * to deal with possible errors from the code below, we call
1236                  * the resize_screen here as well.
1237                  */
1238                 return resize_screen(vc, new_cols, new_rows, user);
1239         }
1240
1241         if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
1242                 return -EINVAL;
1243         newscreen = kzalloc(new_screen_size, GFP_USER);
1244         if (!newscreen)
1245                 return -ENOMEM;
1246
1247         if (get_vc_uniscr(vc)) {
1248                 new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1249                 if (!new_uniscr) {
1250                         kfree(newscreen);
1251                         return -ENOMEM;
1252                 }
1253         }
1254
1255         if (vc_is_sel(vc))
1256                 clear_selection();
1257
1258         old_rows = vc->vc_rows;
1259         old_row_size = vc->vc_size_row;
1260
1261         err = resize_screen(vc, new_cols, new_rows, user);
1262         if (err) {
1263                 kfree(newscreen);
1264                 vc_uniscr_free(new_uniscr);
1265                 return err;
1266         }
1267
1268         vc->vc_rows = new_rows;
1269         vc->vc_cols = new_cols;
1270         vc->vc_size_row = new_row_size;
1271         vc->vc_screenbuf_size = new_screen_size;
1272
1273         rlth = min(old_row_size, new_row_size);
1274         rrem = new_row_size - rlth;
1275         old_origin = vc->vc_origin;
1276         new_origin = (long) newscreen;
1277         new_scr_end = new_origin + new_screen_size;
1278
1279         if (vc->vc_y > new_rows) {
1280                 if (old_rows - vc->vc_y < new_rows) {
1281                         /*
1282                          * Cursor near the bottom, copy contents from the
1283                          * bottom of buffer
1284                          */
1285                         first_copied_row = (old_rows - new_rows);
1286                 } else {
1287                         /*
1288                          * Cursor is in no man's land, copy 1/2 screenful
1289                          * from the top and bottom of cursor position
1290                          */
1291                         first_copied_row = (vc->vc_y - new_rows/2);
1292                 }
1293                 old_origin += first_copied_row * old_row_size;
1294         } else
1295                 first_copied_row = 0;
1296         end = old_origin + old_row_size * min(old_rows, new_rows);
1297
1298         vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1299                             get_vc_uniscr(vc), rlth/2, first_copied_row,
1300                             min(old_rows, new_rows));
1301         vc_uniscr_set(vc, new_uniscr);
1302
1303         update_attr(vc);
1304
1305         while (old_origin < end) {
1306                 scr_memcpyw((unsigned short *) new_origin,
1307                             (unsigned short *) old_origin, rlth);
1308                 if (rrem)
1309                         scr_memsetw((void *)(new_origin + rlth),
1310                                     vc->vc_video_erase_char, rrem);
1311                 old_origin += old_row_size;
1312                 new_origin += new_row_size;
1313         }
1314         if (new_scr_end > new_origin)
1315                 scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1316                             new_scr_end - new_origin);
1317         oldscreen = vc->vc_screenbuf;
1318         vc->vc_screenbuf = newscreen;
1319         vc->vc_screenbuf_size = new_screen_size;
1320         set_origin(vc);
1321         kfree(oldscreen);
1322
1323         /* do part of a reset_terminal() */
1324         vc->vc_top = 0;
1325         vc->vc_bottom = vc->vc_rows;
1326         gotoxy(vc, vc->vc_x, vc->vc_y);
1327         save_cur(vc);
1328
1329         if (tty) {
1330                 /* Rewrite the requested winsize data with the actual
1331                    resulting sizes */
1332                 struct winsize ws;
1333                 memset(&ws, 0, sizeof(ws));
1334                 ws.ws_row = vc->vc_rows;
1335                 ws.ws_col = vc->vc_cols;
1336                 ws.ws_ypixel = vc->vc_scan_lines;
1337                 tty_do_resize(tty, &ws);
1338         }
1339
1340         if (con_is_visible(vc))
1341                 update_screen(vc);
1342         vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1343         notify_update(vc);
1344         return err;
1345 }
1346
1347 /**
1348  *      vc_resize               -       resize a VT
1349  *      @vc: virtual console
1350  *      @cols: columns
1351  *      @rows: rows
1352  *
1353  *      Resize a virtual console as seen from the console end of things. We
1354  *      use the common vc_do_resize methods to update the structures. The
1355  *      caller must hold the console sem to protect console internals and
1356  *      vc->port.tty
1357  */
1358
1359 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1360 {
1361         return vc_do_resize(vc->port.tty, vc, cols, rows);
1362 }
1363
1364 /**
1365  *      vt_resize               -       resize a VT
1366  *      @tty: tty to resize
1367  *      @ws: winsize attributes
1368  *
1369  *      Resize a virtual terminal. This is called by the tty layer as we
1370  *      register our own handler for resizing. The mutual helper does all
1371  *      the actual work.
1372  *
1373  *      Takes the console sem and the called methods then take the tty
1374  *      termios_rwsem and the tty ctrl_lock in that order.
1375  */
1376 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1377 {
1378         struct vc_data *vc = tty->driver_data;
1379         int ret;
1380
1381         console_lock();
1382         ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1383         console_unlock();
1384         return ret;
1385 }
1386
1387 struct vc_data *vc_deallocate(unsigned int currcons)
1388 {
1389         struct vc_data *vc = NULL;
1390
1391         WARN_CONSOLE_UNLOCKED();
1392
1393         if (vc_cons_allocated(currcons)) {
1394                 struct vt_notifier_param param;
1395
1396                 param.vc = vc = vc_cons[currcons].d;
1397                 atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1398                 vcs_remove_sysfs(currcons);
1399                 visual_deinit(vc);
1400                 con_free_unimap(vc);
1401                 put_pid(vc->vt_pid);
1402                 vc_uniscr_set(vc, NULL);
1403                 kfree(vc->vc_screenbuf);
1404                 vc_cons[currcons].d = NULL;
1405         }
1406         return vc;
1407 }
1408
1409 /*
1410  *      VT102 emulator
1411  */
1412
1413 #define set_kbd(vc, x)  vt_set_kbd_mode_bit((vc)->vc_num, (x))
1414 #define clr_kbd(vc, x)  vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1415 #define is_kbd(vc, x)   vt_get_kbd_mode_bit((vc)->vc_num, (x))
1416
1417 #define decarm          VC_REPEAT
1418 #define decckm          VC_CKMODE
1419 #define kbdapplic       VC_APPLIC
1420 #define lnm             VC_CRLF
1421
1422 /*
1423  * this is what the terminal answers to a ESC-Z or csi0c query.
1424  */
1425 #define VT100ID "\033[?1;2c"
1426 #define VT102ID "\033[?6c"
1427
1428 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1429                                        8,12,10,14, 9,13,11,15 };
1430
1431 /* the default colour table, for VGA+ colour systems */
1432 unsigned char default_red[] = {
1433         0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1434         0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1435 };
1436 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1437
1438 unsigned char default_grn[] = {
1439         0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1440         0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1441 };
1442 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1443
1444 unsigned char default_blu[] = {
1445         0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1446         0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1447 };
1448 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1449
1450 /*
1451  * gotoxy() must verify all boundaries, because the arguments
1452  * might also be negative. If the given position is out of
1453  * bounds, the cursor is placed at the nearest margin.
1454  */
1455 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1456 {
1457         int min_y, max_y;
1458
1459         if (new_x < 0)
1460                 vc->vc_x = 0;
1461         else {
1462                 if (new_x >= vc->vc_cols)
1463                         vc->vc_x = vc->vc_cols - 1;
1464                 else
1465                         vc->vc_x = new_x;
1466         }
1467
1468         if (vc->vc_decom) {
1469                 min_y = vc->vc_top;
1470                 max_y = vc->vc_bottom;
1471         } else {
1472                 min_y = 0;
1473                 max_y = vc->vc_rows;
1474         }
1475         if (new_y < min_y)
1476                 vc->vc_y = min_y;
1477         else if (new_y >= max_y)
1478                 vc->vc_y = max_y - 1;
1479         else
1480                 vc->vc_y = new_y;
1481         vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
1482         vc->vc_need_wrap = 0;
1483 }
1484
1485 /* for absolute user moves, when decom is set */
1486 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1487 {
1488         gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1489 }
1490
1491 void scrollback(struct vc_data *vc)
1492 {
1493         scrolldelta(-(vc->vc_rows / 2));
1494 }
1495
1496 void scrollfront(struct vc_data *vc, int lines)
1497 {
1498         if (!lines)
1499                 lines = vc->vc_rows / 2;
1500         scrolldelta(lines);
1501 }
1502
1503 static void lf(struct vc_data *vc)
1504 {
1505         /* don't scroll if above bottom of scrolling region, or
1506          * if below scrolling region
1507          */
1508         if (vc->vc_y + 1 == vc->vc_bottom)
1509                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1510         else if (vc->vc_y < vc->vc_rows - 1) {
1511                 vc->vc_y++;
1512                 vc->vc_pos += vc->vc_size_row;
1513         }
1514         vc->vc_need_wrap = 0;
1515         notify_write(vc, '\n');
1516 }
1517
1518 static void ri(struct vc_data *vc)
1519 {
1520         /* don't scroll if below top of scrolling region, or
1521          * if above scrolling region
1522          */
1523         if (vc->vc_y == vc->vc_top)
1524                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1525         else if (vc->vc_y > 0) {
1526                 vc->vc_y--;
1527                 vc->vc_pos -= vc->vc_size_row;
1528         }
1529         vc->vc_need_wrap = 0;
1530 }
1531
1532 static inline void cr(struct vc_data *vc)
1533 {
1534         vc->vc_pos -= vc->vc_x << 1;
1535         vc->vc_need_wrap = vc->vc_x = 0;
1536         notify_write(vc, '\r');
1537 }
1538
1539 static inline void bs(struct vc_data *vc)
1540 {
1541         if (vc->vc_x) {
1542                 vc->vc_pos -= 2;
1543                 vc->vc_x--;
1544                 vc->vc_need_wrap = 0;
1545                 notify_write(vc, '\b');
1546         }
1547 }
1548
1549 static inline void del(struct vc_data *vc)
1550 {
1551         /* ignored */
1552 }
1553
1554 static void csi_J(struct vc_data *vc, int vpar)
1555 {
1556         unsigned int count;
1557         unsigned short * start;
1558
1559         switch (vpar) {
1560                 case 0: /* erase from cursor to end of display */
1561                         vc_uniscr_clear_line(vc, vc->vc_x,
1562                                              vc->vc_cols - vc->vc_x);
1563                         vc_uniscr_clear_lines(vc, vc->vc_y + 1,
1564                                               vc->vc_rows - vc->vc_y - 1);
1565                         count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1566                         start = (unsigned short *)vc->vc_pos;
1567                         break;
1568                 case 1: /* erase from start to cursor */
1569                         vc_uniscr_clear_line(vc, 0, vc->vc_x + 1);
1570                         vc_uniscr_clear_lines(vc, 0, vc->vc_y);
1571                         count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1572                         start = (unsigned short *)vc->vc_origin;
1573                         break;
1574                 case 3: /* include scrollback */
1575                         flush_scrollback(vc);
1576                         /* fallthrough */
1577                 case 2: /* erase whole display */
1578                         vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1579                         count = vc->vc_cols * vc->vc_rows;
1580                         start = (unsigned short *)vc->vc_origin;
1581                         break;
1582                 default:
1583                         return;
1584         }
1585         scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1586         if (con_should_update(vc))
1587                 do_update_region(vc, (unsigned long) start, count);
1588         vc->vc_need_wrap = 0;
1589 }
1590
1591 static void csi_K(struct vc_data *vc, int vpar)
1592 {
1593         unsigned int count;
1594         unsigned short *start = (unsigned short *)vc->vc_pos;
1595         int offset;
1596
1597         switch (vpar) {
1598                 case 0: /* erase from cursor to end of line */
1599                         offset = 0;
1600                         count = vc->vc_cols - vc->vc_x;
1601                         break;
1602                 case 1: /* erase from start of line to cursor */
1603                         offset = -vc->vc_x;
1604                         count = vc->vc_x + 1;
1605                         break;
1606                 case 2: /* erase whole line */
1607                         offset = -vc->vc_x;
1608                         count = vc->vc_cols;
1609                         break;
1610                 default:
1611                         return;
1612         }
1613         vc_uniscr_clear_line(vc, vc->vc_x + offset, count);
1614         scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1615         vc->vc_need_wrap = 0;
1616         if (con_should_update(vc))
1617                 do_update_region(vc, (unsigned long)(start + offset), count);
1618 }
1619
1620 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1621 {                                         /* not vt100? */
1622         int count;
1623
1624         if (!vpar)
1625                 vpar++;
1626         count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
1627
1628         vc_uniscr_clear_line(vc, vc->vc_x, count);
1629         scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1630         if (con_should_update(vc))
1631                 vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
1632         vc->vc_need_wrap = 0;
1633 }
1634
1635 static void default_attr(struct vc_data *vc)
1636 {
1637         vc->vc_intensity = 1;
1638         vc->vc_italic = 0;
1639         vc->vc_underline = 0;
1640         vc->vc_reverse = 0;
1641         vc->vc_blink = 0;
1642         vc->vc_color = vc->vc_def_color;
1643 }
1644
1645 struct rgb { u8 r; u8 g; u8 b; };
1646
1647 static void rgb_from_256(int i, struct rgb *c)
1648 {
1649         if (i < 8) {            /* Standard colours. */
1650                 c->r = i&1 ? 0xaa : 0x00;
1651                 c->g = i&2 ? 0xaa : 0x00;
1652                 c->b = i&4 ? 0xaa : 0x00;
1653         } else if (i < 16) {
1654                 c->r = i&1 ? 0xff : 0x55;
1655                 c->g = i&2 ? 0xff : 0x55;
1656                 c->b = i&4 ? 0xff : 0x55;
1657         } else if (i < 232) {   /* 6x6x6 colour cube. */
1658                 c->r = (i - 16) / 36 * 85 / 2;
1659                 c->g = (i - 16) / 6 % 6 * 85 / 2;
1660                 c->b = (i - 16) % 6 * 85 / 2;
1661         } else                  /* Grayscale ramp. */
1662                 c->r = c->g = c->b = i * 10 - 2312;
1663 }
1664
1665 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1666 {
1667         u8 hue = 0, max = max3(c->r, c->g, c->b);
1668
1669         if (c->r > max / 2)
1670                 hue |= 4;
1671         if (c->g > max / 2)
1672                 hue |= 2;
1673         if (c->b > max / 2)
1674                 hue |= 1;
1675
1676         if (hue == 7 && max <= 0x55) {
1677                 hue = 0;
1678                 vc->vc_intensity = 2;
1679         } else if (max > 0xaa)
1680                 vc->vc_intensity = 2;
1681         else
1682                 vc->vc_intensity = 1;
1683
1684         vc->vc_color = (vc->vc_color & 0xf0) | hue;
1685 }
1686
1687 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1688 {
1689         /* For backgrounds, err on the dark side. */
1690         vc->vc_color = (vc->vc_color & 0x0f)
1691                 | (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1692 }
1693
1694 /*
1695  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1696  * and thus need to be detected and ignored by hand. Strictly speaking, that
1697  * standard also wants : rather than ; as separators, contrary to ECMA-48, but
1698  * no one produces such codes and almost no one accepts them.
1699  *
1700  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1701  * supporting them.
1702  */
1703 static int vc_t416_color(struct vc_data *vc, int i,
1704                 void(*set_color)(struct vc_data *vc, const struct rgb *c))
1705 {
1706         struct rgb c;
1707
1708         i++;
1709         if (i > vc->vc_npar)
1710                 return i;
1711
1712         if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1713                 /* 256 colours */
1714                 i++;
1715                 rgb_from_256(vc->vc_par[i], &c);
1716         } else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1717                 /* 24 bit */
1718                 c.r = vc->vc_par[i + 1];
1719                 c.g = vc->vc_par[i + 2];
1720                 c.b = vc->vc_par[i + 3];
1721                 i += 3;
1722         } else
1723                 return i;
1724
1725         set_color(vc, &c);
1726
1727         return i;
1728 }
1729
1730 /* console_lock is held */
1731 static void csi_m(struct vc_data *vc)
1732 {
1733         int i;
1734
1735         for (i = 0; i <= vc->vc_npar; i++)
1736                 switch (vc->vc_par[i]) {
1737                 case 0: /* all attributes off */
1738                         default_attr(vc);
1739                         break;
1740                 case 1:
1741                         vc->vc_intensity = 2;
1742                         break;
1743                 case 2:
1744                         vc->vc_intensity = 0;
1745                         break;
1746                 case 3:
1747                         vc->vc_italic = 1;
1748                         break;
1749                 case 21:
1750                         /*
1751                          * No console drivers support double underline, so
1752                          * convert it to a single underline.
1753                          */
1754                 case 4:
1755                         vc->vc_underline = 1;
1756                         break;
1757                 case 5:
1758                         vc->vc_blink = 1;
1759                         break;
1760                 case 7:
1761                         vc->vc_reverse = 1;
1762                         break;
1763                 case 10: /* ANSI X3.64-1979 (SCO-ish?)
1764                           * Select primary font, don't display control chars if
1765                           * defined, don't set bit 8 on output.
1766                           */
1767                         vc->vc_translate = set_translate(vc->vc_charset == 0
1768                                         ? vc->vc_G0_charset
1769                                         : vc->vc_G1_charset, vc);
1770                         vc->vc_disp_ctrl = 0;
1771                         vc->vc_toggle_meta = 0;
1772                         break;
1773                 case 11: /* ANSI X3.64-1979 (SCO-ish?)
1774                           * Select first alternate font, lets chars < 32 be
1775                           * displayed as ROM chars.
1776                           */
1777                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1778                         vc->vc_disp_ctrl = 1;
1779                         vc->vc_toggle_meta = 0;
1780                         break;
1781                 case 12: /* ANSI X3.64-1979 (SCO-ish?)
1782                           * Select second alternate font, toggle high bit
1783                           * before displaying as ROM char.
1784                           */
1785                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1786                         vc->vc_disp_ctrl = 1;
1787                         vc->vc_toggle_meta = 1;
1788                         break;
1789                 case 22:
1790                         vc->vc_intensity = 1;
1791                         break;
1792                 case 23:
1793                         vc->vc_italic = 0;
1794                         break;
1795                 case 24:
1796                         vc->vc_underline = 0;
1797                         break;
1798                 case 25:
1799                         vc->vc_blink = 0;
1800                         break;
1801                 case 27:
1802                         vc->vc_reverse = 0;
1803                         break;
1804                 case 38:
1805                         i = vc_t416_color(vc, i, rgb_foreground);
1806                         break;
1807                 case 48:
1808                         i = vc_t416_color(vc, i, rgb_background);
1809                         break;
1810                 case 39:
1811                         vc->vc_color = (vc->vc_def_color & 0x0f) |
1812                                 (vc->vc_color & 0xf0);
1813                         break;
1814                 case 49:
1815                         vc->vc_color = (vc->vc_def_color & 0xf0) |
1816                                 (vc->vc_color & 0x0f);
1817                         break;
1818                 default:
1819                         if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1820                                 if (vc->vc_par[i] < 100)
1821                                         vc->vc_intensity = 2;
1822                                 vc->vc_par[i] -= 60;
1823                         }
1824                         if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1825                                 vc->vc_color = color_table[vc->vc_par[i] - 30]
1826                                         | (vc->vc_color & 0xf0);
1827                         else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1828                                 vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1829                                         | (vc->vc_color & 0x0f);
1830                         break;
1831                 }
1832         update_attr(vc);
1833 }
1834
1835 static void respond_string(const char *p, struct tty_port *port)
1836 {
1837         while (*p) {
1838                 tty_insert_flip_char(port, *p, 0);
1839                 p++;
1840         }
1841         tty_flip_buffer_push(port);
1842 }
1843
1844 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1845 {
1846         char buf[40];
1847
1848         sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1849         respond_string(buf, tty->port);
1850 }
1851
1852 static inline void status_report(struct tty_struct *tty)
1853 {
1854         respond_string("\033[0n", tty->port);   /* Terminal ok */
1855 }
1856
1857 static inline void respond_ID(struct tty_struct *tty)
1858 {
1859         respond_string(VT102ID, tty->port);
1860 }
1861
1862 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1863 {
1864         char buf[8];
1865
1866         sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1867                 (char)('!' + mry));
1868         respond_string(buf, tty->port);
1869 }
1870
1871 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1872 int mouse_reporting(void)
1873 {
1874         return vc_cons[fg_console].d->vc_report_mouse;
1875 }
1876
1877 /* console_lock is held */
1878 static void set_mode(struct vc_data *vc, int on_off)
1879 {
1880         int i;
1881
1882         for (i = 0; i <= vc->vc_npar; i++)
1883                 if (vc->vc_ques) {
1884                         switch(vc->vc_par[i]) { /* DEC private modes set/reset */
1885                         case 1:                 /* Cursor keys send ^[Ox/^[[x */
1886                                 if (on_off)
1887                                         set_kbd(vc, decckm);
1888                                 else
1889                                         clr_kbd(vc, decckm);
1890                                 break;
1891                         case 3: /* 80/132 mode switch unimplemented */
1892 #if 0
1893                                 vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1894                                 /* this alone does not suffice; some user mode
1895                                    utility has to change the hardware regs */
1896 #endif
1897                                 break;
1898                         case 5:                 /* Inverted screen on/off */
1899                                 if (vc->vc_decscnm != on_off) {
1900                                         vc->vc_decscnm = on_off;
1901                                         invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1902                                         update_attr(vc);
1903                                 }
1904                                 break;
1905                         case 6:                 /* Origin relative/absolute */
1906                                 vc->vc_decom = on_off;
1907                                 gotoxay(vc, 0, 0);
1908                                 break;
1909                         case 7:                 /* Autowrap on/off */
1910                                 vc->vc_decawm = on_off;
1911                                 break;
1912                         case 8:                 /* Autorepeat on/off */
1913                                 if (on_off)
1914                                         set_kbd(vc, decarm);
1915                                 else
1916                                         clr_kbd(vc, decarm);
1917                                 break;
1918                         case 9:
1919                                 vc->vc_report_mouse = on_off ? 1 : 0;
1920                                 break;
1921                         case 25:                /* Cursor on/off */
1922                                 vc->vc_deccm = on_off;
1923                                 break;
1924                         case 1000:
1925                                 vc->vc_report_mouse = on_off ? 2 : 0;
1926                                 break;
1927                         }
1928                 } else {
1929                         switch(vc->vc_par[i]) { /* ANSI modes set/reset */
1930                         case 3:                 /* Monitor (display ctrls) */
1931                                 vc->vc_disp_ctrl = on_off;
1932                                 break;
1933                         case 4:                 /* Insert Mode on/off */
1934                                 vc->vc_decim = on_off;
1935                                 break;
1936                         case 20:                /* Lf, Enter == CrLf/Lf */
1937                                 if (on_off)
1938                                         set_kbd(vc, lnm);
1939                                 else
1940                                         clr_kbd(vc, lnm);
1941                                 break;
1942                         }
1943                 }
1944 }
1945
1946 /* console_lock is held */
1947 static void setterm_command(struct vc_data *vc)
1948 {
1949         switch(vc->vc_par[0]) {
1950                 case 1: /* set color for underline mode */
1951                         if (vc->vc_can_do_color &&
1952                                         vc->vc_par[1] < 16) {
1953                                 vc->vc_ulcolor = color_table[vc->vc_par[1]];
1954                                 if (vc->vc_underline)
1955                                         update_attr(vc);
1956                         }
1957                         break;
1958                 case 2: /* set color for half intensity mode */
1959                         if (vc->vc_can_do_color &&
1960                                         vc->vc_par[1] < 16) {
1961                                 vc->vc_halfcolor = color_table[vc->vc_par[1]];
1962                                 if (vc->vc_intensity == 0)
1963                                         update_attr(vc);
1964                         }
1965                         break;
1966                 case 8: /* store colors as defaults */
1967                         vc->vc_def_color = vc->vc_attr;
1968                         if (vc->vc_hi_font_mask == 0x100)
1969                                 vc->vc_def_color >>= 1;
1970                         default_attr(vc);
1971                         update_attr(vc);
1972                         break;
1973                 case 9: /* set blanking interval */
1974                         blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1975                         poke_blanked_console();
1976                         break;
1977                 case 10: /* set bell frequency in Hz */
1978                         if (vc->vc_npar >= 1)
1979                                 vc->vc_bell_pitch = vc->vc_par[1];
1980                         else
1981                                 vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1982                         break;
1983                 case 11: /* set bell duration in msec */
1984                         if (vc->vc_npar >= 1)
1985                                 vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1986                                         msecs_to_jiffies(vc->vc_par[1]) : 0;
1987                         else
1988                                 vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1989                         break;
1990                 case 12: /* bring specified console to the front */
1991                         if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1992                                 set_console(vc->vc_par[1] - 1);
1993                         break;
1994                 case 13: /* unblank the screen */
1995                         poke_blanked_console();
1996                         break;
1997                 case 14: /* set vesa powerdown interval */
1998                         vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1999                         break;
2000                 case 15: /* activate the previous console */
2001                         set_console(last_console);
2002                         break;
2003                 case 16: /* set cursor blink duration in msec */
2004                         if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
2005                                         vc->vc_par[1] <= USHRT_MAX)
2006                                 vc->vc_cur_blink_ms = vc->vc_par[1];
2007                         else
2008                                 vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2009                         break;
2010         }
2011 }
2012
2013 /* console_lock is held */
2014 static void csi_at(struct vc_data *vc, unsigned int nr)
2015 {
2016         if (nr > vc->vc_cols - vc->vc_x)
2017                 nr = vc->vc_cols - vc->vc_x;
2018         else if (!nr)
2019                 nr = 1;
2020         insert_char(vc, nr);
2021 }
2022
2023 /* console_lock is held */
2024 static void csi_L(struct vc_data *vc, unsigned int nr)
2025 {
2026         if (nr > vc->vc_rows - vc->vc_y)
2027                 nr = vc->vc_rows - vc->vc_y;
2028         else if (!nr)
2029                 nr = 1;
2030         con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_DOWN, nr);
2031         vc->vc_need_wrap = 0;
2032 }
2033
2034 /* console_lock is held */
2035 static void csi_P(struct vc_data *vc, unsigned int nr)
2036 {
2037         if (nr > vc->vc_cols - vc->vc_x)
2038                 nr = vc->vc_cols - vc->vc_x;
2039         else if (!nr)
2040                 nr = 1;
2041         delete_char(vc, nr);
2042 }
2043
2044 /* console_lock is held */
2045 static void csi_M(struct vc_data *vc, unsigned int nr)
2046 {
2047         if (nr > vc->vc_rows - vc->vc_y)
2048                 nr = vc->vc_rows - vc->vc_y;
2049         else if (!nr)
2050                 nr=1;
2051         con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_UP, nr);
2052         vc->vc_need_wrap = 0;
2053 }
2054
2055 /* console_lock is held (except via vc_init->reset_terminal */
2056 static void save_cur(struct vc_data *vc)
2057 {
2058         vc->vc_saved_x          = vc->vc_x;
2059         vc->vc_saved_y          = vc->vc_y;
2060         vc->vc_s_intensity      = vc->vc_intensity;
2061         vc->vc_s_italic         = vc->vc_italic;
2062         vc->vc_s_underline      = vc->vc_underline;
2063         vc->vc_s_blink          = vc->vc_blink;
2064         vc->vc_s_reverse        = vc->vc_reverse;
2065         vc->vc_s_charset        = vc->vc_charset;
2066         vc->vc_s_color          = vc->vc_color;
2067         vc->vc_saved_G0         = vc->vc_G0_charset;
2068         vc->vc_saved_G1         = vc->vc_G1_charset;
2069 }
2070
2071 /* console_lock is held */
2072 static void restore_cur(struct vc_data *vc)
2073 {
2074         gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
2075         vc->vc_intensity        = vc->vc_s_intensity;
2076         vc->vc_italic           = vc->vc_s_italic;
2077         vc->vc_underline        = vc->vc_s_underline;
2078         vc->vc_blink            = vc->vc_s_blink;
2079         vc->vc_reverse          = vc->vc_s_reverse;
2080         vc->vc_charset          = vc->vc_s_charset;
2081         vc->vc_color            = vc->vc_s_color;
2082         vc->vc_G0_charset       = vc->vc_saved_G0;
2083         vc->vc_G1_charset       = vc->vc_saved_G1;
2084         vc->vc_translate        = set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
2085         update_attr(vc);
2086         vc->vc_need_wrap = 0;
2087 }
2088
2089 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2090         EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
2091         ESpalette, ESosc };
2092
2093 /* console_lock is held (except via vc_init()) */
2094 static void reset_terminal(struct vc_data *vc, int do_clear)
2095 {
2096         vc->vc_top              = 0;
2097         vc->vc_bottom           = vc->vc_rows;
2098         vc->vc_state            = ESnormal;
2099         vc->vc_ques             = 0;
2100         vc->vc_translate        = set_translate(LAT1_MAP, vc);
2101         vc->vc_G0_charset       = LAT1_MAP;
2102         vc->vc_G1_charset       = GRAF_MAP;
2103         vc->vc_charset          = 0;
2104         vc->vc_need_wrap        = 0;
2105         vc->vc_report_mouse     = 0;
2106         vc->vc_utf              = default_utf8;
2107         vc->vc_utf_count        = 0;
2108
2109         vc->vc_disp_ctrl        = 0;
2110         vc->vc_toggle_meta      = 0;
2111
2112         vc->vc_decscnm          = 0;
2113         vc->vc_decom            = 0;
2114         vc->vc_decawm           = 1;
2115         vc->vc_deccm            = global_cursor_default;
2116         vc->vc_decim            = 0;
2117
2118         vt_reset_keyboard(vc->vc_num);
2119
2120         vc->vc_cursor_type = cur_default;
2121         vc->vc_complement_mask = vc->vc_s_complement_mask;
2122
2123         default_attr(vc);
2124         update_attr(vc);
2125
2126         vc->vc_tab_stop[0]      =
2127         vc->vc_tab_stop[1]      =
2128         vc->vc_tab_stop[2]      =
2129         vc->vc_tab_stop[3]      =
2130         vc->vc_tab_stop[4]      =
2131         vc->vc_tab_stop[5]      =
2132         vc->vc_tab_stop[6]      =
2133         vc->vc_tab_stop[7]      = 0x01010101;
2134
2135         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2136         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2137         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2138
2139         gotoxy(vc, 0, 0);
2140         save_cur(vc);
2141         if (do_clear)
2142             csi_J(vc, 2);
2143 }
2144
2145 /* console_lock is held */
2146 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2147 {
2148         /*
2149          *  Control characters can be used in the _middle_
2150          *  of an escape sequence.
2151          */
2152         if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
2153                 return;
2154         switch (c) {
2155         case 0:
2156                 return;
2157         case 7:
2158                 if (vc->vc_state == ESosc)
2159                         vc->vc_state = ESnormal;
2160                 else if (vc->vc_bell_duration)
2161                         kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2162                 return;
2163         case 8:
2164                 bs(vc);
2165                 return;
2166         case 9:
2167                 vc->vc_pos -= (vc->vc_x << 1);
2168                 while (vc->vc_x < vc->vc_cols - 1) {
2169                         vc->vc_x++;
2170                         if (vc->vc_tab_stop[7 & (vc->vc_x >> 5)] & (1 << (vc->vc_x & 31)))
2171                                 break;
2172                 }
2173                 vc->vc_pos += (vc->vc_x << 1);
2174                 notify_write(vc, '\t');
2175                 return;
2176         case 10: case 11: case 12:
2177                 lf(vc);
2178                 if (!is_kbd(vc, lnm))
2179                         return;
2180         case 13:
2181                 cr(vc);
2182                 return;
2183         case 14:
2184                 vc->vc_charset = 1;
2185                 vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2186                 vc->vc_disp_ctrl = 1;
2187                 return;
2188         case 15:
2189                 vc->vc_charset = 0;
2190                 vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2191                 vc->vc_disp_ctrl = 0;
2192                 return;
2193         case 24: case 26:
2194                 vc->vc_state = ESnormal;
2195                 return;
2196         case 27:
2197                 vc->vc_state = ESesc;
2198                 return;
2199         case 127:
2200                 del(vc);
2201                 return;
2202         case 128+27:
2203                 vc->vc_state = ESsquare;
2204                 return;
2205         }
2206         switch(vc->vc_state) {
2207         case ESesc:
2208                 vc->vc_state = ESnormal;
2209                 switch (c) {
2210                 case '[':
2211                         vc->vc_state = ESsquare;
2212                         return;
2213                 case ']':
2214                         vc->vc_state = ESnonstd;
2215                         return;
2216                 case '%':
2217                         vc->vc_state = ESpercent;
2218                         return;
2219                 case 'E':
2220                         cr(vc);
2221                         lf(vc);
2222                         return;
2223                 case 'M':
2224                         ri(vc);
2225                         return;
2226                 case 'D':
2227                         lf(vc);
2228                         return;
2229                 case 'H':
2230                         vc->vc_tab_stop[7 & (vc->vc_x >> 5)] |= (1 << (vc->vc_x & 31));
2231                         return;
2232                 case 'Z':
2233                         respond_ID(tty);
2234                         return;
2235                 case '7':
2236                         save_cur(vc);
2237                         return;
2238                 case '8':
2239                         restore_cur(vc);
2240                         return;
2241                 case '(':
2242                         vc->vc_state = ESsetG0;
2243                         return;
2244                 case ')':
2245                         vc->vc_state = ESsetG1;
2246                         return;
2247                 case '#':
2248                         vc->vc_state = EShash;
2249                         return;
2250                 case 'c':
2251                         reset_terminal(vc, 1);
2252                         return;
2253                 case '>':  /* Numeric keypad */
2254                         clr_kbd(vc, kbdapplic);
2255                         return;
2256                 case '=':  /* Appl. keypad */
2257                         set_kbd(vc, kbdapplic);
2258                         return;
2259                 }
2260                 return;
2261         case ESnonstd:
2262                 if (c=='P') {   /* palette escape sequence */
2263                         for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2264                                 vc->vc_par[vc->vc_npar] = 0;
2265                         vc->vc_npar = 0;
2266                         vc->vc_state = ESpalette;
2267                         return;
2268                 } else if (c=='R') {   /* reset palette */
2269                         reset_palette(vc);
2270                         vc->vc_state = ESnormal;
2271                 } else if (c>='0' && c<='9')
2272                         vc->vc_state = ESosc;
2273                 else
2274                         vc->vc_state = ESnormal;
2275                 return;
2276         case ESpalette:
2277                 if (isxdigit(c)) {
2278                         vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2279                         if (vc->vc_npar == 7) {
2280                                 int i = vc->vc_par[0] * 3, j = 1;
2281                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2282                                 vc->vc_palette[i++] += vc->vc_par[j++];
2283                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2284                                 vc->vc_palette[i++] += vc->vc_par[j++];
2285                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2286                                 vc->vc_palette[i] += vc->vc_par[j];
2287                                 set_palette(vc);
2288                                 vc->vc_state = ESnormal;
2289                         }
2290                 } else
2291                         vc->vc_state = ESnormal;
2292                 return;
2293         case ESsquare:
2294                 for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2295                         vc->vc_par[vc->vc_npar] = 0;
2296                 vc->vc_npar = 0;
2297                 vc->vc_state = ESgetpars;
2298                 if (c == '[') { /* Function key */
2299                         vc->vc_state=ESfunckey;
2300                         return;
2301                 }
2302                 vc->vc_ques = (c == '?');
2303                 if (vc->vc_ques)
2304                         return;
2305         case ESgetpars:
2306                 if (c == ';' && vc->vc_npar < NPAR - 1) {
2307                         vc->vc_npar++;
2308                         return;
2309                 } else if (c>='0' && c<='9') {
2310                         vc->vc_par[vc->vc_npar] *= 10;
2311                         vc->vc_par[vc->vc_npar] += c - '0';
2312                         return;
2313                 }
2314                 vc->vc_state = ESnormal;
2315                 switch(c) {
2316                 case 'h':
2317                         set_mode(vc, 1);
2318                         return;
2319                 case 'l':
2320                         set_mode(vc, 0);
2321                         return;
2322                 case 'c':
2323                         if (vc->vc_ques) {
2324                                 if (vc->vc_par[0])
2325                                         vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
2326                                 else
2327                                         vc->vc_cursor_type = cur_default;
2328                                 return;
2329                         }
2330                         break;
2331                 case 'm':
2332                         if (vc->vc_ques) {
2333                                 clear_selection();
2334                                 if (vc->vc_par[0])
2335                                         vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2336                                 else
2337                                         vc->vc_complement_mask = vc->vc_s_complement_mask;
2338                                 return;
2339                         }
2340                         break;
2341                 case 'n':
2342                         if (!vc->vc_ques) {
2343                                 if (vc->vc_par[0] == 5)
2344                                         status_report(tty);
2345                                 else if (vc->vc_par[0] == 6)
2346                                         cursor_report(vc, tty);
2347                         }
2348                         return;
2349                 }
2350                 if (vc->vc_ques) {
2351                         vc->vc_ques = 0;
2352                         return;
2353                 }
2354                 switch(c) {
2355                 case 'G': case '`':
2356                         if (vc->vc_par[0])
2357                                 vc->vc_par[0]--;
2358                         gotoxy(vc, vc->vc_par[0], vc->vc_y);
2359                         return;
2360                 case 'A':
2361                         if (!vc->vc_par[0])
2362                                 vc->vc_par[0]++;
2363                         gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
2364                         return;
2365                 case 'B': case 'e':
2366                         if (!vc->vc_par[0])
2367                                 vc->vc_par[0]++;
2368                         gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
2369                         return;
2370                 case 'C': case 'a':
2371                         if (!vc->vc_par[0])
2372                                 vc->vc_par[0]++;
2373                         gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
2374                         return;
2375                 case 'D':
2376                         if (!vc->vc_par[0])
2377                                 vc->vc_par[0]++;
2378                         gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
2379                         return;
2380                 case 'E':
2381                         if (!vc->vc_par[0])
2382                                 vc->vc_par[0]++;
2383                         gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
2384                         return;
2385                 case 'F':
2386                         if (!vc->vc_par[0])
2387                                 vc->vc_par[0]++;
2388                         gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
2389                         return;
2390                 case 'd':
2391                         if (vc->vc_par[0])
2392                                 vc->vc_par[0]--;
2393                         gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
2394                         return;
2395                 case 'H': case 'f':
2396                         if (vc->vc_par[0])
2397                                 vc->vc_par[0]--;
2398                         if (vc->vc_par[1])
2399                                 vc->vc_par[1]--;
2400                         gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2401                         return;
2402                 case 'J':
2403                         csi_J(vc, vc->vc_par[0]);
2404                         return;
2405                 case 'K':
2406                         csi_K(vc, vc->vc_par[0]);
2407                         return;
2408                 case 'L':
2409                         csi_L(vc, vc->vc_par[0]);
2410                         return;
2411                 case 'M':
2412                         csi_M(vc, vc->vc_par[0]);
2413                         return;
2414                 case 'P':
2415                         csi_P(vc, vc->vc_par[0]);
2416                         return;
2417                 case 'c':
2418                         if (!vc->vc_par[0])
2419                                 respond_ID(tty);
2420                         return;
2421                 case 'g':
2422                         if (!vc->vc_par[0])
2423                                 vc->vc_tab_stop[7 & (vc->vc_x >> 5)] &= ~(1 << (vc->vc_x & 31));
2424                         else if (vc->vc_par[0] == 3) {
2425                                 vc->vc_tab_stop[0] =
2426                                         vc->vc_tab_stop[1] =
2427                                         vc->vc_tab_stop[2] =
2428                                         vc->vc_tab_stop[3] =
2429                                         vc->vc_tab_stop[4] =
2430                                         vc->vc_tab_stop[5] =
2431                                         vc->vc_tab_stop[6] =
2432                                         vc->vc_tab_stop[7] = 0;
2433                         }
2434                         return;
2435                 case 'm':
2436                         csi_m(vc);
2437                         return;
2438                 case 'q': /* DECLL - but only 3 leds */
2439                         /* map 0,1,2,3 to 0,1,2,4 */
2440                         if (vc->vc_par[0] < 4)
2441                                 vt_set_led_state(vc->vc_num,
2442                                             (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2443                         return;
2444                 case 'r':
2445                         if (!vc->vc_par[0])
2446                                 vc->vc_par[0]++;
2447                         if (!vc->vc_par[1])
2448                                 vc->vc_par[1] = vc->vc_rows;
2449                         /* Minimum allowed region is 2 lines */
2450                         if (vc->vc_par[0] < vc->vc_par[1] &&
2451                             vc->vc_par[1] <= vc->vc_rows) {
2452                                 vc->vc_top = vc->vc_par[0] - 1;
2453                                 vc->vc_bottom = vc->vc_par[1];
2454                                 gotoxay(vc, 0, 0);
2455                         }
2456                         return;
2457                 case 's':
2458                         save_cur(vc);
2459                         return;
2460                 case 'u':
2461                         restore_cur(vc);
2462                         return;
2463                 case 'X':
2464                         csi_X(vc, vc->vc_par[0]);
2465                         return;
2466                 case '@':
2467                         csi_at(vc, vc->vc_par[0]);
2468                         return;
2469                 case ']': /* setterm functions */
2470                         setterm_command(vc);
2471                         return;
2472                 }
2473                 return;
2474         case ESpercent:
2475                 vc->vc_state = ESnormal;
2476                 switch (c) {
2477                 case '@':  /* defined in ISO 2022 */
2478                         vc->vc_utf = 0;
2479                         return;
2480                 case 'G':  /* prelim official escape code */
2481                 case '8':  /* retained for compatibility */
2482                         vc->vc_utf = 1;
2483                         return;
2484                 }
2485                 return;
2486         case ESfunckey:
2487                 vc->vc_state = ESnormal;
2488                 return;
2489         case EShash:
2490                 vc->vc_state = ESnormal;
2491                 if (c == '8') {
2492                         /* DEC screen alignment test. kludge :-) */
2493                         vc->vc_video_erase_char =
2494                                 (vc->vc_video_erase_char & 0xff00) | 'E';
2495                         csi_J(vc, 2);
2496                         vc->vc_video_erase_char =
2497                                 (vc->vc_video_erase_char & 0xff00) | ' ';
2498                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2499                 }
2500                 return;
2501         case ESsetG0:
2502                 if (c == '0')
2503                         vc->vc_G0_charset = GRAF_MAP;
2504                 else if (c == 'B')
2505                         vc->vc_G0_charset = LAT1_MAP;
2506                 else if (c == 'U')
2507                         vc->vc_G0_charset = IBMPC_MAP;
2508                 else if (c == 'K')
2509                         vc->vc_G0_charset = USER_MAP;
2510                 if (vc->vc_charset == 0)
2511                         vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2512                 vc->vc_state = ESnormal;
2513                 return;
2514         case ESsetG1:
2515                 if (c == '0')
2516                         vc->vc_G1_charset = GRAF_MAP;
2517                 else if (c == 'B')
2518                         vc->vc_G1_charset = LAT1_MAP;
2519                 else if (c == 'U')
2520                         vc->vc_G1_charset = IBMPC_MAP;
2521                 else if (c == 'K')
2522                         vc->vc_G1_charset = USER_MAP;
2523                 if (vc->vc_charset == 1)
2524                         vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2525                 vc->vc_state = ESnormal;
2526                 return;
2527         case ESosc:
2528                 return;
2529         default:
2530                 vc->vc_state = ESnormal;
2531         }
2532 }
2533
2534 /* is_double_width() is based on the wcwidth() implementation by
2535  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2536  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2537  */
2538 struct interval {
2539         uint32_t first;
2540         uint32_t last;
2541 };
2542
2543 static int ucs_cmp(const void *key, const void *elt)
2544 {
2545         uint32_t ucs = *(uint32_t *)key;
2546         struct interval e = *(struct interval *) elt;
2547
2548         if (ucs > e.last)
2549                 return 1;
2550         else if (ucs < e.first)
2551                 return -1;
2552         return 0;
2553 }
2554
2555 static int is_double_width(uint32_t ucs)
2556 {
2557         static const struct interval double_width[] = {
2558                 { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2559                 { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2560                 { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2561                 { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2562         };
2563         if (ucs < double_width[0].first ||
2564             ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2565                 return 0;
2566
2567         return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2568                         sizeof(struct interval), ucs_cmp) != NULL;
2569 }
2570
2571 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2572                 unsigned long draw_to, int *draw_x)
2573 {
2574         if (*draw_x < 0)
2575                 return;
2576
2577         vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2578                         (u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2579         *draw_x = -1;
2580 }
2581
2582 /* acquires console_lock */
2583 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2584 {
2585         int c, next_c, tc, ok, n = 0, draw_x = -1;
2586         unsigned int currcons;
2587         unsigned long draw_from = 0, draw_to = 0;
2588         struct vc_data *vc;
2589         unsigned char vc_attr;
2590         struct vt_notifier_param param;
2591         uint8_t rescan;
2592         uint8_t inverse;
2593         uint8_t width;
2594         u16 himask, charmask;
2595
2596         if (in_interrupt())
2597                 return count;
2598
2599         might_sleep();
2600
2601         console_lock();
2602         vc = tty->driver_data;
2603         if (vc == NULL) {
2604                 pr_err("vt: argh, driver_data is NULL !\n");
2605                 console_unlock();
2606                 return 0;
2607         }
2608
2609         currcons = vc->vc_num;
2610         if (!vc_cons_allocated(currcons)) {
2611                 /* could this happen? */
2612                 pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2613                 console_unlock();
2614                 return 0;
2615         }
2616
2617         himask = vc->vc_hi_font_mask;
2618         charmask = himask ? 0x1ff : 0xff;
2619
2620         /* undraw cursor first */
2621         if (con_is_fg(vc))
2622                 hide_cursor(vc);
2623
2624         param.vc = vc;
2625
2626         while (!tty->stopped && count) {
2627                 int orig = *buf;
2628                 c = orig;
2629                 buf++;
2630                 n++;
2631                 count--;
2632                 rescan = 0;
2633                 inverse = 0;
2634                 width = 1;
2635
2636                 /* Do no translation at all in control states */
2637                 if (vc->vc_state != ESnormal) {
2638                         tc = c;
2639                 } else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2640                     /* Combine UTF-8 into Unicode in vc_utf_char.
2641                      * vc_utf_count is the number of continuation bytes still
2642                      * expected to arrive.
2643                      * vc_npar is the number of continuation bytes arrived so
2644                      * far
2645                      */
2646 rescan_last_byte:
2647                     if ((c & 0xc0) == 0x80) {
2648                         /* Continuation byte received */
2649                         static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2650                         if (vc->vc_utf_count) {
2651                             vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2652                             vc->vc_npar++;
2653                             if (--vc->vc_utf_count) {
2654                                 /* Still need some bytes */
2655                                 continue;
2656                             }
2657                             /* Got a whole character */
2658                             c = vc->vc_utf_char;
2659                             /* Reject overlong sequences */
2660                             if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2661                                         c > utf8_length_changes[vc->vc_npar])
2662                                 c = 0xfffd;
2663                         } else {
2664                             /* Unexpected continuation byte */
2665                             vc->vc_utf_count = 0;
2666                             c = 0xfffd;
2667                         }
2668                     } else {
2669                         /* Single ASCII byte or first byte of a sequence received */
2670                         if (vc->vc_utf_count) {
2671                             /* Continuation byte expected */
2672                             rescan = 1;
2673                             vc->vc_utf_count = 0;
2674                             c = 0xfffd;
2675                         } else if (c > 0x7f) {
2676                             /* First byte of a multibyte sequence received */
2677                             vc->vc_npar = 0;
2678                             if ((c & 0xe0) == 0xc0) {
2679                                 vc->vc_utf_count = 1;
2680                                 vc->vc_utf_char = (c & 0x1f);
2681                             } else if ((c & 0xf0) == 0xe0) {
2682                                 vc->vc_utf_count = 2;
2683                                 vc->vc_utf_char = (c & 0x0f);
2684                             } else if ((c & 0xf8) == 0xf0) {
2685                                 vc->vc_utf_count = 3;
2686                                 vc->vc_utf_char = (c & 0x07);
2687                             } else if ((c & 0xfc) == 0xf8) {
2688                                 vc->vc_utf_count = 4;
2689                                 vc->vc_utf_char = (c & 0x03);
2690                             } else if ((c & 0xfe) == 0xfc) {
2691                                 vc->vc_utf_count = 5;
2692                                 vc->vc_utf_char = (c & 0x01);
2693                             } else {
2694                                 /* 254 and 255 are invalid */
2695                                 c = 0xfffd;
2696                             }
2697                             if (vc->vc_utf_count) {
2698                                 /* Still need some bytes */
2699                                 continue;
2700                             }
2701                         }
2702                         /* Nothing to do if an ASCII byte was received */
2703                     }
2704                     /* End of UTF-8 decoding. */
2705                     /* c is the received character, or U+FFFD for invalid sequences. */
2706                     /* Replace invalid Unicode code points with U+FFFD too */
2707                     if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2708                         c = 0xfffd;
2709                     tc = c;
2710                 } else {        /* no utf or alternate charset mode */
2711                     tc = vc_translate(vc, c);
2712                 }
2713
2714                 param.c = tc;
2715                 if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2716                                         &param) == NOTIFY_STOP)
2717                         continue;
2718
2719                 /* If the original code was a control character we
2720                  * only allow a glyph to be displayed if the code is
2721                  * not normally used (such as for cursor movement) or
2722                  * if the disp_ctrl mode has been explicitly enabled.
2723                  * Certain characters (as given by the CTRL_ALWAYS
2724                  * bitmap) are always displayed as control characters,
2725                  * as the console would be pretty useless without
2726                  * them; to display an arbitrary font position use the
2727                  * direct-to-font zone in UTF-8 mode.
2728                  */
2729                 ok = tc && (c >= 32 ||
2730                             !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2731                                   vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2732                         && (c != 127 || vc->vc_disp_ctrl)
2733                         && (c != 128+27);
2734
2735                 if (vc->vc_state == ESnormal && ok) {
2736                         if (vc->vc_utf && !vc->vc_disp_ctrl) {
2737                                 if (is_double_width(c))
2738                                         width = 2;
2739                         }
2740                         /* Now try to find out how to display it */
2741                         tc = conv_uni_to_pc(vc, tc);
2742                         if (tc & ~charmask) {
2743                                 if (tc == -1 || tc == -2) {
2744                                     continue; /* nothing to display */
2745                                 }
2746                                 /* Glyph not found */
2747                                 if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2748                                     /* In legacy mode use the glyph we get by a 1:1 mapping.
2749                                        This would make absolutely no sense with Unicode in mind,
2750                                        but do this for ASCII characters since a font may lack
2751                                        Unicode mapping info and we don't want to end up with
2752                                        having question marks only. */
2753                                     tc = c;
2754                                 } else {
2755                                     /* Display U+FFFD. If it's not found, display an inverse question mark. */
2756                                     tc = conv_uni_to_pc(vc, 0xfffd);
2757                                     if (tc < 0) {
2758                                         inverse = 1;
2759                                         tc = conv_uni_to_pc(vc, '?');
2760                                         if (tc < 0) tc = '?';
2761                                     }
2762                                 }
2763                         }
2764
2765                         if (!inverse) {
2766                                 vc_attr = vc->vc_attr;
2767                         } else {
2768                                 /* invert vc_attr */
2769                                 if (!vc->vc_can_do_color) {
2770                                         vc_attr = (vc->vc_attr) ^ 0x08;
2771                                 } else if (vc->vc_hi_font_mask == 0x100) {
2772                                         vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2773                                 } else {
2774                                         vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2775                                 }
2776                                 con_flush(vc, draw_from, draw_to, &draw_x);
2777                         }
2778
2779                         next_c = c;
2780                         while (1) {
2781                                 if (vc->vc_need_wrap || vc->vc_decim)
2782                                         con_flush(vc, draw_from, draw_to,
2783                                                         &draw_x);
2784                                 if (vc->vc_need_wrap) {
2785                                         cr(vc);
2786                                         lf(vc);
2787                                 }
2788                                 if (vc->vc_decim)
2789                                         insert_char(vc, 1);
2790                                 vc_uniscr_putc(vc, next_c);
2791                                 scr_writew(himask ?
2792                                              ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2793                                              (vc_attr << 8) + tc,
2794                                            (u16 *) vc->vc_pos);
2795                                 if (con_should_update(vc) && draw_x < 0) {
2796                                         draw_x = vc->vc_x;
2797                                         draw_from = vc->vc_pos;
2798                                 }
2799                                 if (vc->vc_x == vc->vc_cols - 1) {
2800                                         vc->vc_need_wrap = vc->vc_decawm;
2801                                         draw_to = vc->vc_pos + 2;
2802                                 } else {
2803                                         vc->vc_x++;
2804                                         draw_to = (vc->vc_pos += 2);
2805                                 }
2806
2807                                 if (!--width) break;
2808
2809                                 tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2810                                 if (tc < 0) tc = ' ';
2811                                 next_c = ' ';
2812                         }
2813                         notify_write(vc, c);
2814
2815                         if (inverse)
2816                                 con_flush(vc, draw_from, draw_to, &draw_x);
2817
2818                         if (rescan) {
2819                                 rescan = 0;
2820                                 inverse = 0;
2821                                 width = 1;
2822                                 c = orig;
2823                                 goto rescan_last_byte;
2824                         }
2825                         continue;
2826                 }
2827                 con_flush(vc, draw_from, draw_to, &draw_x);
2828                 do_con_trol(tty, vc, orig);
2829         }
2830         con_flush(vc, draw_from, draw_to, &draw_x);
2831         vc_uniscr_debug_check(vc);
2832         console_conditional_schedule();
2833         notify_update(vc);
2834         console_unlock();
2835         return n;
2836 }
2837
2838 /*
2839  * This is the console switching callback.
2840  *
2841  * Doing console switching in a process context allows
2842  * us to do the switches asynchronously (needed when we want
2843  * to switch due to a keyboard interrupt).  Synchronization
2844  * with other console code and prevention of re-entrancy is
2845  * ensured with console_lock.
2846  */
2847 static void console_callback(struct work_struct *ignored)
2848 {
2849         console_lock();
2850
2851         if (want_console >= 0) {
2852                 if (want_console != fg_console &&
2853                     vc_cons_allocated(want_console)) {
2854                         hide_cursor(vc_cons[fg_console].d);
2855                         change_console(vc_cons[want_console].d);
2856                         /* we only changed when the console had already
2857                            been allocated - a new console is not created
2858                            in an interrupt routine */
2859                 }
2860                 want_console = -1;
2861         }
2862         if (do_poke_blanked_console) { /* do not unblank for a LED change */
2863                 do_poke_blanked_console = 0;
2864                 poke_blanked_console();
2865         }
2866         if (scrollback_delta) {
2867                 struct vc_data *vc = vc_cons[fg_console].d;
2868                 clear_selection();
2869                 if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2870                         vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2871                 scrollback_delta = 0;
2872         }
2873         if (blank_timer_expired) {
2874                 do_blank_screen(0);
2875                 blank_timer_expired = 0;
2876         }
2877         notify_update(vc_cons[fg_console].d);
2878
2879         console_unlock();
2880 }
2881
2882 int set_console(int nr)
2883 {
2884         struct vc_data *vc = vc_cons[fg_console].d;
2885
2886         if (!vc_cons_allocated(nr) || vt_dont_switch ||
2887                 (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2888
2889                 /*
2890                  * Console switch will fail in console_callback() or
2891                  * change_console() so there is no point scheduling
2892                  * the callback
2893                  *
2894                  * Existing set_console() users don't check the return
2895                  * value so this shouldn't break anything
2896                  */
2897                 return -EINVAL;
2898         }
2899
2900         want_console = nr;
2901         schedule_console_callback();
2902
2903         return 0;
2904 }
2905
2906 struct tty_driver *console_driver;
2907
2908 #ifdef CONFIG_VT_CONSOLE
2909
2910 /**
2911  * vt_kmsg_redirect() - Sets/gets the kernel message console
2912  * @new:        The new virtual terminal number or -1 if the console should stay
2913  *              unchanged
2914  *
2915  * By default, the kernel messages are always printed on the current virtual
2916  * console. However, the user may modify that default with the
2917  * TIOCL_SETKMSGREDIRECT ioctl call.
2918  *
2919  * This function sets the kernel message console to be @new. It returns the old
2920  * virtual console number. The virtual terminal number 0 (both as parameter and
2921  * return value) means no redirection (i.e. always printed on the currently
2922  * active console).
2923  *
2924  * The parameter -1 means that only the current console is returned, but the
2925  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2926  * case to make the code more understandable.
2927  *
2928  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2929  * the parameter and always returns 0.
2930  */
2931 int vt_kmsg_redirect(int new)
2932 {
2933         static int kmsg_con;
2934
2935         if (new != -1)
2936                 return xchg(&kmsg_con, new);
2937         else
2938                 return kmsg_con;
2939 }
2940
2941 /*
2942  *      Console on virtual terminal
2943  *
2944  * The console must be locked when we get here.
2945  */
2946
2947 static void vt_console_print(struct console *co, const char *b, unsigned count)
2948 {
2949         struct vc_data *vc = vc_cons[fg_console].d;
2950         unsigned char c;
2951         static DEFINE_SPINLOCK(printing_lock);
2952         const ushort *start;
2953         ushort start_x, cnt;
2954         int kmsg_console;
2955
2956         /* console busy or not yet initialized */
2957         if (!printable)
2958                 return;
2959         if (!spin_trylock(&printing_lock))
2960                 return;
2961
2962         kmsg_console = vt_get_kmsg_redirect();
2963         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2964                 vc = vc_cons[kmsg_console - 1].d;
2965
2966         if (!vc_cons_allocated(fg_console)) {
2967                 /* impossible */
2968                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2969                 goto quit;
2970         }
2971
2972         if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
2973                 goto quit;
2974
2975         /* undraw cursor first */
2976         if (con_is_fg(vc))
2977                 hide_cursor(vc);
2978
2979         start = (ushort *)vc->vc_pos;
2980         start_x = vc->vc_x;
2981         cnt = 0;
2982         while (count--) {
2983                 c = *b++;
2984                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2985                         if (cnt && con_is_visible(vc))
2986                                 vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x);
2987                         cnt = 0;
2988                         if (c == 8) {           /* backspace */
2989                                 bs(vc);
2990                                 start = (ushort *)vc->vc_pos;
2991                                 start_x = vc->vc_x;
2992                                 continue;
2993                         }
2994                         if (c != 13)
2995                                 lf(vc);
2996                         cr(vc);
2997                         start = (ushort *)vc->vc_pos;
2998                         start_x = vc->vc_x;
2999                         if (c == 10 || c == 13)
3000                                 continue;
3001                 }
3002                 vc_uniscr_putc(vc, c);
3003                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3004                 notify_write(vc, c);
3005                 cnt++;
3006                 if (vc->vc_x == vc->vc_cols - 1) {
3007                         vc->vc_need_wrap = 1;
3008                 } else {
3009                         vc->vc_pos += 2;
3010                         vc->vc_x++;
3011                 }
3012         }
3013         if (cnt && con_is_visible(vc))
3014                 vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x);
3015         set_cursor(vc);
3016         notify_update(vc);
3017
3018 quit:
3019         spin_unlock(&printing_lock);
3020 }
3021
3022 static struct tty_driver *vt_console_device(struct console *c, int *index)
3023 {
3024         *index = c->index ? c->index-1 : fg_console;
3025         return console_driver;
3026 }
3027
3028 static struct console vt_console_driver = {
3029         .name           = "tty",
3030         .write          = vt_console_print,
3031         .device         = vt_console_device,
3032         .unblank        = unblank_screen,
3033         .flags          = CON_PRINTBUFFER,
3034         .index          = -1,
3035 };
3036 #endif
3037
3038 /*
3039  *      Handling of Linux-specific VC ioctls
3040  */
3041
3042 /*
3043  * Generally a bit racy with respect to console_lock();.
3044  *
3045  * There are some functions which don't need it.
3046  *
3047  * There are some functions which can sleep for arbitrary periods
3048  * (paste_selection) but we don't need the lock there anyway.
3049  *
3050  * set_selection has locking, and definitely needs it
3051  */
3052
3053 int tioclinux(struct tty_struct *tty, unsigned long arg)
3054 {
3055         char type, data;
3056         char __user *p = (char __user *)arg;
3057         int lines;
3058         int ret;
3059
3060         if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3061                 return -EPERM;
3062         if (get_user(type, p))
3063                 return -EFAULT;
3064         ret = 0;
3065
3066         switch (type)
3067         {
3068                 case TIOCL_SETSEL:
3069                         ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
3070                         break;
3071                 case TIOCL_PASTESEL:
3072                         ret = paste_selection(tty);
3073                         break;
3074                 case TIOCL_UNBLANKSCREEN:
3075                         console_lock();
3076                         unblank_screen();
3077                         console_unlock();
3078                         break;
3079                 case TIOCL_SELLOADLUT:
3080                         console_lock();
3081                         ret = sel_loadlut(p);
3082                         console_unlock();
3083                         break;
3084                 case TIOCL_GETSHIFTSTATE:
3085
3086         /*
3087          * Make it possible to react to Shift+Mousebutton.
3088          * Note that 'shift_state' is an undocumented
3089          * kernel-internal variable; programs not closely
3090          * related to the kernel should not use this.
3091          */
3092                         data = vt_get_shift_state();
3093                         ret = put_user(data, p);
3094                         break;
3095                 case TIOCL_GETMOUSEREPORTING:
3096                         console_lock(); /* May be overkill */
3097                         data = mouse_reporting();
3098                         console_unlock();
3099                         ret = put_user(data, p);
3100                         break;
3101                 case TIOCL_SETVESABLANK:
3102                         console_lock();
3103                         ret = set_vesa_blanking(p);
3104                         console_unlock();
3105                         break;
3106                 case TIOCL_GETKMSGREDIRECT:
3107                         data = vt_get_kmsg_redirect();
3108                         ret = put_user(data, p);
3109                         break;
3110                 case TIOCL_SETKMSGREDIRECT:
3111                         if (!capable(CAP_SYS_ADMIN)) {
3112                                 ret = -EPERM;
3113                         } else {
3114                                 if (get_user(data, p+1))
3115                                         ret = -EFAULT;
3116                                 else
3117                                         vt_kmsg_redirect(data);
3118                         }
3119                         break;
3120                 case TIOCL_GETFGCONSOLE:
3121                         /* No locking needed as this is a transiently
3122                            correct return anyway if the caller hasn't
3123                            disabled switching */
3124                         ret = fg_console;
3125                         break;
3126                 case TIOCL_SCROLLCONSOLE:
3127                         if (get_user(lines, (s32 __user *)(p+4))) {
3128                                 ret = -EFAULT;
3129                         } else {
3130                                 /* Need the console lock here. Note that lots
3131                                    of other calls need fixing before the lock
3132                                    is actually useful ! */
3133                                 console_lock();
3134                                 scrollfront(vc_cons[fg_console].d, lines);
3135                                 console_unlock();
3136                                 ret = 0;
3137                         }
3138                         break;
3139                 case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
3140                         console_lock();
3141                         ignore_poke = 1;
3142                         do_blank_screen(0);
3143                         console_unlock();
3144                         break;
3145                 case TIOCL_BLANKEDSCREEN:
3146                         ret = console_blanked;
3147                         break;
3148                 default:
3149                         ret = -EINVAL;
3150                         break;
3151         }
3152         return ret;
3153 }
3154
3155 /*
3156  * /dev/ttyN handling
3157  */
3158
3159 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3160 {
3161         int     retval;
3162
3163         retval = do_con_write(tty, buf, count);
3164         con_flush_chars(tty);
3165
3166         return retval;
3167 }
3168
3169 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3170 {
3171         if (in_interrupt())
3172                 return 0;       /* n_r3964 calls put_char() from interrupt context */
3173         return do_con_write(tty, &ch, 1);
3174 }
3175
3176 static int con_write_room(struct tty_struct *tty)
3177 {
3178         if (tty->stopped)
3179                 return 0;
3180         return 32768;           /* No limit, really; we're not buffering */
3181 }
3182
3183 static int con_chars_in_buffer(struct tty_struct *tty)
3184 {
3185         return 0;               /* we're not buffering */
3186 }
3187
3188 /*
3189  * con_throttle and con_unthrottle are only used for
3190  * paste_selection(), which has to stuff in a large number of
3191  * characters...
3192  */
3193 static void con_throttle(struct tty_struct *tty)
3194 {
3195 }
3196
3197 static void con_unthrottle(struct tty_struct *tty)
3198 {
3199         struct vc_data *vc = tty->driver_data;
3200
3201         wake_up_interruptible(&vc->paste_wait);
3202 }
3203
3204 /*
3205  * Turn the Scroll-Lock LED on when the tty is stopped
3206  */
3207 static void con_stop(struct tty_struct *tty)
3208 {
3209         int console_num;
3210         if (!tty)
3211                 return;
3212         console_num = tty->index;
3213         if (!vc_cons_allocated(console_num))
3214                 return;
3215         vt_kbd_con_stop(console_num);
3216 }
3217
3218 /*
3219  * Turn the Scroll-Lock LED off when the console is started
3220  */
3221 static void con_start(struct tty_struct *tty)
3222 {
3223         int console_num;
3224         if (!tty)
3225                 return;
3226         console_num = tty->index;
3227         if (!vc_cons_allocated(console_num))
3228                 return;
3229         vt_kbd_con_start(console_num);
3230 }
3231
3232 static void con_flush_chars(struct tty_struct *tty)
3233 {
3234         struct vc_data *vc;
3235
3236         if (in_interrupt())     /* from flush_to_ldisc */
3237                 return;
3238
3239         /* if we race with con_close(), vt may be null */
3240         console_lock();
3241         vc = tty->driver_data;
3242         if (vc)
3243                 set_cursor(vc);
3244         console_unlock();
3245 }
3246
3247 /*
3248  * Allocate the console screen memory.
3249  */
3250 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3251 {
3252         unsigned int currcons = tty->index;
3253         struct vc_data *vc;
3254         int ret;
3255
3256         console_lock();
3257         ret = vc_allocate(currcons);
3258         if (ret)
3259                 goto unlock;
3260
3261         vc = vc_cons[currcons].d;
3262
3263         /* Still being freed */
3264         if (vc->port.tty) {
3265                 ret = -ERESTARTSYS;
3266                 goto unlock;
3267         }
3268
3269         ret = tty_port_install(&vc->port, driver, tty);
3270         if (ret)
3271                 goto unlock;
3272
3273         tty->driver_data = vc;
3274         vc->port.tty = tty;
3275         tty_port_get(&vc->port);
3276
3277         if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3278                 tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3279                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3280         }
3281         if (vc->vc_utf)
3282                 tty->termios.c_iflag |= IUTF8;
3283         else
3284                 tty->termios.c_iflag &= ~IUTF8;
3285 unlock:
3286         console_unlock();
3287         return ret;
3288 }
3289
3290 static int con_open(struct tty_struct *tty, struct file *filp)
3291 {
3292         /* everything done in install */
3293         return 0;
3294 }
3295
3296
3297 static void con_close(struct tty_struct *tty, struct file *filp)
3298 {
3299         /* Nothing to do - we defer to shutdown */
3300 }
3301
3302 static void con_shutdown(struct tty_struct *tty)
3303 {
3304         struct vc_data *vc = tty->driver_data;
3305         BUG_ON(vc == NULL);
3306         console_lock();
3307         vc->port.tty = NULL;
3308         console_unlock();
3309 }
3310
3311 static void con_cleanup(struct tty_struct *tty)
3312 {
3313         struct vc_data *vc = tty->driver_data;
3314
3315         tty_port_put(&vc->port);
3316 }
3317
3318 static int default_color           = 7; /* white */
3319 static int default_italic_color    = 2; // green (ASCII)
3320 static int default_underline_color = 3; // cyan (ASCII)
3321 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3322 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3323 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3324
3325 static void vc_init(struct vc_data *vc, unsigned int rows,
3326                     unsigned int cols, int do_clear)
3327 {
3328         int j, k ;
3329
3330         vc->vc_cols = cols;
3331         vc->vc_rows = rows;
3332         vc->vc_size_row = cols << 1;
3333         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3334
3335         set_origin(vc);
3336         vc->vc_pos = vc->vc_origin;
3337         reset_vc(vc);
3338         for (j=k=0; j<16; j++) {
3339                 vc->vc_palette[k++] = default_red[j] ;
3340                 vc->vc_palette[k++] = default_grn[j] ;
3341                 vc->vc_palette[k++] = default_blu[j] ;
3342         }
3343         vc->vc_def_color       = default_color;
3344         vc->vc_ulcolor         = default_underline_color;
3345         vc->vc_itcolor         = default_italic_color;
3346         vc->vc_halfcolor       = 0x08;   /* grey */
3347         init_waitqueue_head(&vc->paste_wait);
3348         reset_terminal(vc, do_clear);
3349 }
3350
3351 /*
3352  * This routine initializes console interrupts, and does nothing
3353  * else. If you want the screen to clear, call tty_write with
3354  * the appropriate escape-sequence.
3355  */
3356
3357 static int __init con_init(void)
3358 {
3359         const char *display_desc = NULL;
3360         struct vc_data *vc;
3361         unsigned int currcons = 0, i;
3362
3363         console_lock();
3364
3365         if (conswitchp)
3366                 display_desc = conswitchp->con_startup();
3367         if (!display_desc) {
3368                 fg_console = 0;
3369                 console_unlock();
3370                 return 0;
3371         }
3372
3373         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3374                 struct con_driver *con_driver = &registered_con_driver[i];
3375
3376                 if (con_driver->con == NULL) {
3377                         con_driver->con = conswitchp;
3378                         con_driver->desc = display_desc;
3379                         con_driver->flag = CON_DRIVER_FLAG_INIT;
3380                         con_driver->first = 0;
3381                         con_driver->last = MAX_NR_CONSOLES - 1;
3382                         break;
3383                 }
3384         }
3385
3386         for (i = 0; i < MAX_NR_CONSOLES; i++)
3387                 con_driver_map[i] = conswitchp;
3388
3389         if (blankinterval) {
3390                 blank_state = blank_normal_wait;
3391                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3392         }
3393
3394         for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3395                 vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3396                 INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3397                 tty_port_init(&vc->port);
3398                 visual_init(vc, currcons, 1);
3399                 /* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3400                 vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3401                 vc_init(vc, vc->vc_rows, vc->vc_cols,
3402                         currcons || !vc->vc_sw->con_save_screen);
3403         }
3404         currcons = fg_console = 0;
3405         master_display_fg = vc = vc_cons[currcons].d;
3406         set_origin(vc);
3407         save_screen(vc);
3408         gotoxy(vc, vc->vc_x, vc->vc_y);
3409         csi_J(vc, 0);
3410         update_screen(vc);
3411         pr_info("Console: %s %s %dx%d\n",
3412                 vc->vc_can_do_color ? "colour" : "mono",
3413                 display_desc, vc->vc_cols, vc->vc_rows);
3414         printable = 1;
3415
3416         console_unlock();
3417
3418 #ifdef CONFIG_VT_CONSOLE
3419         register_console(&vt_console_driver);
3420 #endif
3421         return 0;
3422 }
3423 console_initcall(con_init);
3424
3425 static const struct tty_operations con_ops = {
3426         .install = con_install,
3427         .open = con_open,
3428         .close = con_close,
3429         .write = con_write,
3430         .write_room = con_write_room,
3431         .put_char = con_put_char,
3432         .flush_chars = con_flush_chars,
3433         .chars_in_buffer = con_chars_in_buffer,
3434         .ioctl = vt_ioctl,
3435 #ifdef CONFIG_COMPAT
3436         .compat_ioctl = vt_compat_ioctl,
3437 #endif
3438         .stop = con_stop,
3439         .start = con_start,
3440         .throttle = con_throttle,
3441         .unthrottle = con_unthrottle,
3442         .resize = vt_resize,
3443         .shutdown = con_shutdown,
3444         .cleanup = con_cleanup,
3445 };
3446
3447 static struct cdev vc0_cdev;
3448
3449 static ssize_t show_tty_active(struct device *dev,
3450                                 struct device_attribute *attr, char *buf)
3451 {
3452         return sprintf(buf, "tty%d\n", fg_console + 1);
3453 }
3454 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3455
3456 static struct attribute *vt_dev_attrs[] = {
3457         &dev_attr_active.attr,
3458         NULL
3459 };
3460
3461 ATTRIBUTE_GROUPS(vt_dev);
3462
3463 int __init vty_init(const struct file_operations *console_fops)
3464 {
3465         cdev_init(&vc0_cdev, console_fops);
3466         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3467             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3468                 panic("Couldn't register /dev/tty0 driver\n");
3469         tty0dev = device_create_with_groups(tty_class, NULL,
3470                                             MKDEV(TTY_MAJOR, 0), NULL,
3471                                             vt_dev_groups, "tty0");
3472         if (IS_ERR(tty0dev))
3473                 tty0dev = NULL;
3474
3475         vcs_init();
3476
3477         console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3478         if (!console_driver)
3479                 panic("Couldn't allocate console driver\n");
3480
3481         console_driver->name = "tty";
3482         console_driver->name_base = 1;
3483         console_driver->major = TTY_MAJOR;
3484         console_driver->minor_start = 1;
3485         console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3486         console_driver->init_termios = tty_std_termios;
3487         if (default_utf8)
3488                 console_driver->init_termios.c_iflag |= IUTF8;
3489         console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3490         tty_set_operations(console_driver, &con_ops);
3491         if (tty_register_driver(console_driver))
3492                 panic("Couldn't register console driver\n");
3493         kbd_init();
3494         console_map_init();
3495 #ifdef CONFIG_MDA_CONSOLE
3496         mda_console_init();
3497 #endif
3498         return 0;
3499 }
3500
3501 #ifndef VT_SINGLE_DRIVER
3502
3503 static struct class *vtconsole_class;
3504
3505 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3506                            int deflt)
3507 {
3508         struct module *owner = csw->owner;
3509         const char *desc = NULL;
3510         struct con_driver *con_driver;
3511         int i, j = -1, k = -1, retval = -ENODEV;
3512
3513         if (!try_module_get(owner))
3514                 return -ENODEV;
3515
3516         WARN_CONSOLE_UNLOCKED();
3517
3518         /* check if driver is registered */
3519         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3520                 con_driver = &registered_con_driver[i];
3521
3522                 if (con_driver->con == csw) {
3523                         desc = con_driver->desc;
3524                         retval = 0;
3525                         break;
3526                 }
3527         }
3528
3529         if (retval)
3530                 goto err;
3531
3532         if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3533                 csw->con_startup();
3534                 con_driver->flag |= CON_DRIVER_FLAG_INIT;
3535         }
3536
3537         if (deflt) {
3538                 if (conswitchp)
3539                         module_put(conswitchp->owner);
3540
3541                 __module_get(owner);
3542                 conswitchp = csw;
3543         }
3544
3545         first = max(first, con_driver->first);
3546         last = min(last, con_driver->last);
3547
3548         for (i = first; i <= last; i++) {
3549                 int old_was_color;
3550                 struct vc_data *vc = vc_cons[i].d;
3551
3552                 if (con_driver_map[i])
3553                         module_put(con_driver_map[i]->owner);
3554                 __module_get(owner);
3555                 con_driver_map[i] = csw;
3556
3557                 if (!vc || !vc->vc_sw)
3558                         continue;
3559
3560                 j = i;
3561
3562                 if (con_is_visible(vc)) {
3563                         k = i;
3564                         save_screen(vc);
3565                 }
3566
3567                 old_was_color = vc->vc_can_do_color;
3568                 vc->vc_sw->con_deinit(vc);
3569                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3570                 visual_init(vc, i, 0);
3571                 set_origin(vc);
3572                 update_attr(vc);
3573
3574                 /* If the console changed between mono <-> color, then
3575                  * the attributes in the screenbuf will be wrong.  The
3576                  * following resets all attributes to something sane.
3577                  */
3578                 if (old_was_color != vc->vc_can_do_color)
3579                         clear_buffer_attributes(vc);
3580         }
3581
3582         pr_info("Console: switching ");
3583         if (!deflt)
3584                 pr_cont("consoles %d-%d ", first + 1, last + 1);
3585         if (j >= 0) {
3586                 struct vc_data *vc = vc_cons[j].d;
3587
3588                 pr_cont("to %s %s %dx%d\n",
3589                         vc->vc_can_do_color ? "colour" : "mono",
3590                         desc, vc->vc_cols, vc->vc_rows);
3591
3592                 if (k >= 0) {
3593                         vc = vc_cons[k].d;
3594                         update_screen(vc);
3595                 }
3596         } else {
3597                 pr_cont("to %s\n", desc);
3598         }
3599
3600         retval = 0;
3601 err:
3602         module_put(owner);
3603         return retval;
3604 };
3605
3606
3607 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3608 /* unlocked version of unbind_con_driver() */
3609 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3610 {
3611         struct module *owner = csw->owner;
3612         const struct consw *defcsw = NULL;
3613         struct con_driver *con_driver = NULL, *con_back = NULL;
3614         int i, retval = -ENODEV;
3615
3616         if (!try_module_get(owner))
3617                 return -ENODEV;
3618
3619         WARN_CONSOLE_UNLOCKED();
3620
3621         /* check if driver is registered and if it is unbindable */
3622         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3623                 con_driver = &registered_con_driver[i];
3624
3625                 if (con_driver->con == csw &&
3626                     con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3627                         retval = 0;
3628                         break;
3629                 }
3630         }
3631
3632         if (retval)
3633                 goto err;
3634
3635         retval = -ENODEV;
3636
3637         /* check if backup driver exists */
3638         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3639                 con_back = &registered_con_driver[i];
3640
3641                 if (con_back->con && con_back->con != csw) {
3642                         defcsw = con_back->con;
3643                         retval = 0;
3644                         break;
3645                 }
3646         }
3647
3648         if (retval)
3649                 goto err;
3650
3651         if (!con_is_bound(csw))
3652                 goto err;
3653
3654         first = max(first, con_driver->first);
3655         last = min(last, con_driver->last);
3656
3657         for (i = first; i <= last; i++) {
3658                 if (con_driver_map[i] == csw) {
3659                         module_put(csw->owner);
3660                         con_driver_map[i] = NULL;
3661                 }
3662         }
3663
3664         if (!con_is_bound(defcsw)) {
3665                 const struct consw *defconsw = conswitchp;
3666
3667                 defcsw->con_startup();
3668                 con_back->flag |= CON_DRIVER_FLAG_INIT;
3669                 /*
3670                  * vgacon may change the default driver to point
3671                  * to dummycon, we restore it here...
3672                  */
3673                 conswitchp = defconsw;
3674         }
3675
3676         if (!con_is_bound(csw))
3677                 con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3678
3679         /* ignore return value, binding should not fail */
3680         do_bind_con_driver(defcsw, first, last, deflt);
3681 err:
3682         module_put(owner);
3683         return retval;
3684
3685 }
3686 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3687
3688 static int vt_bind(struct con_driver *con)
3689 {
3690         const struct consw *defcsw = NULL, *csw = NULL;
3691         int i, more = 1, first = -1, last = -1, deflt = 0;
3692
3693         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3694                 goto err;
3695
3696         csw = con->con;
3697
3698         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3699                 struct con_driver *con = &registered_con_driver[i];
3700
3701                 if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3702                         defcsw = con->con;
3703                         break;
3704                 }
3705         }
3706
3707         if (!defcsw)
3708                 goto err;
3709
3710         while (more) {
3711                 more = 0;
3712
3713                 for (i = con->first; i <= con->last; i++) {
3714                         if (con_driver_map[i] == defcsw) {
3715                                 if (first == -1)
3716                                         first = i;
3717                                 last = i;
3718                                 more = 1;
3719                         } else if (first != -1)
3720                                 break;
3721                 }
3722
3723                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3724                         deflt = 1;
3725
3726                 if (first != -1)
3727                         do_bind_con_driver(csw, first, last, deflt);
3728
3729                 first = -1;
3730                 last = -1;
3731                 deflt = 0;
3732         }
3733
3734 err:
3735         return 0;
3736 }
3737
3738 static int vt_unbind(struct con_driver *con)
3739 {
3740         const struct consw *csw = NULL;
3741         int i, more = 1, first = -1, last = -1, deflt = 0;
3742         int ret;
3743
3744         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3745                 goto err;
3746
3747         csw = con->con;
3748
3749         while (more) {
3750                 more = 0;
3751
3752                 for (i = con->first; i <= con->last; i++) {
3753                         if (con_driver_map[i] == csw) {
3754                                 if (first == -1)
3755                                         first = i;
3756                                 last = i;
3757                                 more = 1;
3758                         } else if (first != -1)
3759                                 break;
3760                 }
3761
3762                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3763                         deflt = 1;
3764
3765                 if (first != -1) {
3766                         ret = do_unbind_con_driver(csw, first, last, deflt);
3767                         if (ret != 0)
3768                                 return ret;
3769                 }
3770
3771                 first = -1;
3772                 last = -1;
3773                 deflt = 0;
3774         }
3775
3776 err:
3777         return 0;
3778 }
3779 #else
3780 static inline int vt_bind(struct con_driver *con)
3781 {
3782         return 0;
3783 }
3784 static inline int vt_unbind(struct con_driver *con)
3785 {
3786         return 0;
3787 }
3788 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3789
3790 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3791                           const char *buf, size_t count)
3792 {
3793         struct con_driver *con = dev_get_drvdata(dev);
3794         int bind = simple_strtoul(buf, NULL, 0);
3795
3796         console_lock();
3797
3798         if (bind)
3799                 vt_bind(con);
3800         else
3801                 vt_unbind(con);
3802
3803         console_unlock();
3804
3805         return count;
3806 }
3807
3808 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3809                          char *buf)
3810 {
3811         struct con_driver *con = dev_get_drvdata(dev);
3812         int bind = con_is_bound(con->con);
3813
3814         return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3815 }
3816
3817 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3818                          char *buf)
3819 {
3820         struct con_driver *con = dev_get_drvdata(dev);
3821
3822         return snprintf(buf, PAGE_SIZE, "%s %s\n",
3823                         (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3824                          con->desc);
3825
3826 }
3827
3828 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3829 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3830
3831 static struct attribute *con_dev_attrs[] = {
3832         &dev_attr_bind.attr,
3833         &dev_attr_name.attr,
3834         NULL
3835 };
3836
3837 ATTRIBUTE_GROUPS(con_dev);
3838
3839 static int vtconsole_init_device(struct con_driver *con)
3840 {
3841         con->flag |= CON_DRIVER_FLAG_ATTR;
3842         return 0;
3843 }
3844
3845 static void vtconsole_deinit_device(struct con_driver *con)
3846 {
3847         con->flag &= ~CON_DRIVER_FLAG_ATTR;
3848 }
3849
3850 /**
3851  * con_is_bound - checks if driver is bound to the console
3852  * @csw: console driver
3853  *
3854  * RETURNS: zero if unbound, nonzero if bound
3855  *
3856  * Drivers can call this and if zero, they should release
3857  * all resources allocated on con_startup()
3858  */
3859 int con_is_bound(const struct consw *csw)
3860 {
3861         int i, bound = 0;
3862
3863         for (i = 0; i < MAX_NR_CONSOLES; i++) {
3864                 if (con_driver_map[i] == csw) {
3865                         bound = 1;
3866                         break;
3867                 }
3868         }
3869
3870         return bound;
3871 }
3872 EXPORT_SYMBOL(con_is_bound);
3873
3874 /**
3875  * con_debug_enter - prepare the console for the kernel debugger
3876  * @sw: console driver
3877  *
3878  * Called when the console is taken over by the kernel debugger, this
3879  * function needs to save the current console state, then put the console
3880  * into a state suitable for the kernel debugger.
3881  *
3882  * RETURNS:
3883  * Zero on success, nonzero if a failure occurred when trying to prepare
3884  * the console for the debugger.
3885  */
3886 int con_debug_enter(struct vc_data *vc)
3887 {
3888         int ret = 0;
3889
3890         saved_fg_console = fg_console;
3891         saved_last_console = last_console;
3892         saved_want_console = want_console;
3893         saved_vc_mode = vc->vc_mode;
3894         saved_console_blanked = console_blanked;
3895         vc->vc_mode = KD_TEXT;
3896         console_blanked = 0;
3897         if (vc->vc_sw->con_debug_enter)
3898                 ret = vc->vc_sw->con_debug_enter(vc);
3899 #ifdef CONFIG_KGDB_KDB
3900         /* Set the initial LINES variable if it is not already set */
3901         if (vc->vc_rows < 999) {
3902                 int linecount;
3903                 char lns[4];
3904                 const char *setargs[3] = {
3905                         "set",
3906                         "LINES",
3907                         lns,
3908                 };
3909                 if (kdbgetintenv(setargs[0], &linecount)) {
3910                         snprintf(lns, 4, "%i", vc->vc_rows);
3911                         kdb_set(2, setargs);
3912                 }
3913         }
3914         if (vc->vc_cols < 999) {
3915                 int colcount;
3916                 char cols[4];
3917                 const char *setargs[3] = {
3918                         "set",
3919                         "COLUMNS",
3920                         cols,
3921                 };
3922                 if (kdbgetintenv(setargs[0], &colcount)) {
3923                         snprintf(cols, 4, "%i", vc->vc_cols);
3924                         kdb_set(2, setargs);
3925                 }
3926         }
3927 #endif /* CONFIG_KGDB_KDB */
3928         return ret;
3929 }
3930 EXPORT_SYMBOL_GPL(con_debug_enter);
3931
3932 /**
3933  * con_debug_leave - restore console state
3934  * @sw: console driver
3935  *
3936  * Restore the console state to what it was before the kernel debugger
3937  * was invoked.
3938  *
3939  * RETURNS:
3940  * Zero on success, nonzero if a failure occurred when trying to restore
3941  * the console.
3942  */
3943 int con_debug_leave(void)
3944 {
3945         struct vc_data *vc;
3946         int ret = 0;
3947
3948         fg_console = saved_fg_console;
3949         last_console = saved_last_console;
3950         want_console = saved_want_console;
3951         console_blanked = saved_console_blanked;
3952         vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3953
3954         vc = vc_cons[fg_console].d;
3955         if (vc->vc_sw->con_debug_leave)
3956                 ret = vc->vc_sw->con_debug_leave(vc);
3957         return ret;
3958 }
3959 EXPORT_SYMBOL_GPL(con_debug_leave);
3960
3961 static int do_register_con_driver(const struct consw *csw, int first, int last)
3962 {
3963         struct module *owner = csw->owner;
3964         struct con_driver *con_driver;
3965         const char *desc;
3966         int i, retval;
3967
3968         WARN_CONSOLE_UNLOCKED();
3969
3970         if (!try_module_get(owner))
3971                 return -ENODEV;
3972
3973         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3974                 con_driver = &registered_con_driver[i];
3975
3976                 /* already registered */
3977                 if (con_driver->con == csw) {
3978                         retval = -EBUSY;
3979                         goto err;
3980                 }
3981         }
3982
3983         desc = csw->con_startup();
3984         if (!desc) {
3985                 retval = -ENODEV;
3986                 goto err;
3987         }
3988
3989         retval = -EINVAL;
3990
3991         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3992                 con_driver = &registered_con_driver[i];
3993
3994                 if (con_driver->con == NULL &&
3995                     !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3996                         con_driver->con = csw;
3997                         con_driver->desc = desc;
3998                         con_driver->node = i;
3999                         con_driver->flag = CON_DRIVER_FLAG_MODULE |
4000                                            CON_DRIVER_FLAG_INIT;
4001                         con_driver->first = first;
4002                         con_driver->last = last;
4003                         retval = 0;
4004                         break;
4005                 }
4006         }
4007
4008         if (retval)
4009                 goto err;
4010
4011         con_driver->dev =
4012                 device_create_with_groups(vtconsole_class, NULL,
4013                                           MKDEV(0, con_driver->node),
4014                                           con_driver, con_dev_groups,
4015                                           "vtcon%i", con_driver->node);
4016         if (IS_ERR(con_driver->dev)) {
4017                 pr_warn("Unable to create device for %s; errno = %ld\n",
4018                         con_driver->desc, PTR_ERR(con_driver->dev));
4019                 con_driver->dev = NULL;
4020         } else {
4021                 vtconsole_init_device(con_driver);
4022         }
4023
4024 err:
4025         module_put(owner);
4026         return retval;
4027 }
4028
4029
4030 /**
4031  * do_unregister_con_driver - unregister console driver from console layer
4032  * @csw: console driver
4033  *
4034  * DESCRIPTION: All drivers that registers to the console layer must
4035  * call this function upon exit, or if the console driver is in a state
4036  * where it won't be able to handle console services, such as the
4037  * framebuffer console without loaded framebuffer drivers.
4038  *
4039  * The driver must unbind first prior to unregistration.
4040  */
4041 int do_unregister_con_driver(const struct consw *csw)
4042 {
4043         int i;
4044
4045         /* cannot unregister a bound driver */
4046         if (con_is_bound(csw))
4047                 return -EBUSY;
4048
4049         if (csw == conswitchp)
4050                 return -EINVAL;
4051
4052         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4053                 struct con_driver *con_driver = &registered_con_driver[i];
4054
4055                 if (con_driver->con == csw) {
4056                         /*
4057                          * Defer the removal of the sysfs entries since that
4058                          * will acquire the kernfs s_active lock and we can't
4059                          * acquire this lock while holding the console lock:
4060                          * the unbind sysfs entry imposes already the opposite
4061                          * order. Reset con already here to prevent any later
4062                          * lookup to succeed and mark this slot as zombie, so
4063                          * it won't get reused until we complete the removal
4064                          * in the deferred work.
4065                          */
4066                         con_driver->con = NULL;
4067                         con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4068                         schedule_work(&con_driver_unregister_work);
4069
4070                         return 0;
4071                 }
4072         }
4073
4074         return -ENODEV;
4075 }
4076 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4077
4078 static void con_driver_unregister_callback(struct work_struct *ignored)
4079 {
4080         int i;
4081
4082         console_lock();
4083
4084         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4085                 struct con_driver *con_driver = &registered_con_driver[i];
4086
4087                 if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4088                         continue;
4089
4090                 console_unlock();
4091
4092                 vtconsole_deinit_device(con_driver);
4093                 device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4094
4095                 console_lock();
4096
4097                 if (WARN_ON_ONCE(con_driver->con))
4098                         con_driver->con = NULL;
4099                 con_driver->desc = NULL;
4100                 con_driver->dev = NULL;
4101                 con_driver->node = 0;
4102                 WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4103                 con_driver->flag = 0;
4104                 con_driver->first = 0;
4105                 con_driver->last = 0;
4106         }
4107
4108         console_unlock();
4109 }
4110
4111 /*
4112  *      If we support more console drivers, this function is used
4113  *      when a driver wants to take over some existing consoles
4114  *      and become default driver for newly opened ones.
4115  *
4116  *      do_take_over_console is basically a register followed by unbind
4117  */
4118 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4119 {
4120         int err;
4121
4122         err = do_register_con_driver(csw, first, last);
4123         /*
4124          * If we get an busy error we still want to bind the console driver
4125          * and return success, as we may have unbound the console driver
4126          * but not unregistered it.
4127          */
4128         if (err == -EBUSY)
4129                 err = 0;
4130         if (!err)
4131                 do_bind_con_driver(csw, first, last, deflt);
4132
4133         return err;
4134 }
4135 EXPORT_SYMBOL_GPL(do_take_over_console);
4136
4137
4138 /*
4139  * give_up_console is a wrapper to unregister_con_driver. It will only
4140  * work if driver is fully unbound.
4141  */
4142 void give_up_console(const struct consw *csw)
4143 {
4144         console_lock();
4145         do_unregister_con_driver(csw);
4146         console_unlock();
4147 }
4148
4149 static int __init vtconsole_class_init(void)
4150 {
4151         int i;
4152
4153         vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4154         if (IS_ERR(vtconsole_class)) {
4155                 pr_warn("Unable to create vt console class; errno = %ld\n",
4156                         PTR_ERR(vtconsole_class));
4157                 vtconsole_class = NULL;
4158         }
4159
4160         /* Add system drivers to sysfs */
4161         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4162                 struct con_driver *con = &registered_con_driver[i];
4163
4164                 if (con->con && !con->dev) {
4165                         con->dev =
4166                                 device_create_with_groups(vtconsole_class, NULL,
4167                                                           MKDEV(0, con->node),
4168                                                           con, con_dev_groups,
4169                                                           "vtcon%i", con->node);
4170
4171                         if (IS_ERR(con->dev)) {
4172                                 pr_warn("Unable to create device for %s; errno = %ld\n",
4173                                         con->desc, PTR_ERR(con->dev));
4174                                 con->dev = NULL;
4175                         } else {
4176                                 vtconsole_init_device(con);
4177                         }
4178                 }
4179         }
4180
4181         return 0;
4182 }
4183 postcore_initcall(vtconsole_class_init);
4184
4185 #endif
4186
4187 /*
4188  *      Screen blanking
4189  */
4190
4191 static int set_vesa_blanking(char __user *p)
4192 {
4193         unsigned int mode;
4194
4195         if (get_user(mode, p + 1))
4196                 return -EFAULT;
4197
4198         vesa_blank_mode = (mode < 4) ? mode : 0;
4199         return 0;
4200 }
4201
4202 void do_blank_screen(int entering_gfx)
4203 {
4204         struct vc_data *vc = vc_cons[fg_console].d;
4205         int i;
4206
4207         WARN_CONSOLE_UNLOCKED();
4208
4209         if (console_blanked) {
4210                 if (blank_state == blank_vesa_wait) {
4211                         blank_state = blank_off;
4212                         vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4213                 }
4214                 return;
4215         }
4216
4217         /* entering graphics mode? */
4218         if (entering_gfx) {
4219                 hide_cursor(vc);
4220                 save_screen(vc);
4221                 vc->vc_sw->con_blank(vc, -1, 1);
4222                 console_blanked = fg_console + 1;
4223                 blank_state = blank_off;
4224                 set_origin(vc);
4225                 return;
4226         }
4227
4228         blank_state = blank_off;
4229
4230         /* don't blank graphics */
4231         if (vc->vc_mode != KD_TEXT) {
4232                 console_blanked = fg_console + 1;
4233                 return;
4234         }
4235
4236         hide_cursor(vc);
4237         del_timer_sync(&console_timer);
4238         blank_timer_expired = 0;
4239
4240         save_screen(vc);
4241         /* In case we need to reset origin, blanking hook returns 1 */
4242         i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4243         console_blanked = fg_console + 1;
4244         if (i)
4245                 set_origin(vc);
4246
4247         if (console_blank_hook && console_blank_hook(1))
4248                 return;
4249
4250         if (vesa_off_interval && vesa_blank_mode) {
4251                 blank_state = blank_vesa_wait;
4252                 mod_timer(&console_timer, jiffies + vesa_off_interval);
4253         }
4254         vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4255 }
4256 EXPORT_SYMBOL(do_blank_screen);
4257
4258 /*
4259  * Called by timer as well as from vt_console_driver
4260  */
4261 void do_unblank_screen(int leaving_gfx)
4262 {
4263         struct vc_data *vc;
4264
4265         /* This should now always be called from a "sane" (read: can schedule)
4266          * context for the sake of the low level drivers, except in the special
4267          * case of oops_in_progress
4268          */
4269         if (!oops_in_progress)
4270                 might_sleep();
4271
4272         WARN_CONSOLE_UNLOCKED();
4273
4274         ignore_poke = 0;
4275         if (!console_blanked)
4276                 return;
4277         if (!vc_cons_allocated(fg_console)) {
4278                 /* impossible */
4279                 pr_warn("unblank_screen: tty %d not allocated ??\n",
4280                         fg_console + 1);
4281                 return;
4282         }
4283         vc = vc_cons[fg_console].d;
4284         /* Try to unblank in oops case too */
4285         if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
4286                 return; /* but leave console_blanked != 0 */
4287
4288         if (blankinterval) {
4289                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4290                 blank_state = blank_normal_wait;
4291         }
4292
4293         console_blanked = 0;
4294         if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
4295                 /* Low-level driver cannot restore -> do it ourselves */
4296                 update_screen(vc);
4297         if (console_blank_hook)
4298                 console_blank_hook(0);
4299         set_palette(vc);
4300         set_cursor(vc);
4301         vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4302 }
4303 EXPORT_SYMBOL(do_unblank_screen);
4304
4305 /*
4306  * This is called by the outside world to cause a forced unblank, mostly for
4307  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4308  * call it with 1 as an argument and so force a mode restore... that may kill
4309  * X or at least garbage the screen but would also make the Oops visible...
4310  */
4311 void unblank_screen(void)
4312 {
4313         do_unblank_screen(0);
4314 }
4315
4316 /*
4317  * We defer the timer blanking to work queue so it can take the console mutex
4318  * (console operations can still happen at irq time, but only from printk which
4319  * has the console mutex. Not perfect yet, but better than no locking
4320  */
4321 static void blank_screen_t(struct timer_list *unused)
4322 {
4323         blank_timer_expired = 1;
4324         schedule_work(&console_work);
4325 }
4326
4327 void poke_blanked_console(void)
4328 {
4329         WARN_CONSOLE_UNLOCKED();
4330
4331         /* Add this so we quickly catch whoever might call us in a non
4332          * safe context. Nowadays, unblank_screen() isn't to be called in
4333          * atomic contexts and is allowed to schedule (with the special case
4334          * of oops_in_progress, but that isn't of any concern for this
4335          * function. --BenH.
4336          */
4337         might_sleep();
4338
4339         /* This isn't perfectly race free, but a race here would be mostly harmless,
4340          * at worse, we'll do a spurrious blank and it's unlikely
4341          */
4342         del_timer(&console_timer);
4343         blank_timer_expired = 0;
4344
4345         if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4346                 return;
4347         if (console_blanked)
4348                 unblank_screen();
4349         else if (blankinterval) {
4350                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4351                 blank_state = blank_normal_wait;
4352         }
4353 }
4354
4355 /*
4356  *      Palettes
4357  */
4358
4359 static void set_palette(struct vc_data *vc)
4360 {
4361         WARN_CONSOLE_UNLOCKED();
4362
4363         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4364                 vc->vc_sw->con_set_palette(vc, color_table);
4365 }
4366
4367 /*
4368  * Load palette into the DAC registers. arg points to a colour
4369  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4370  */
4371
4372 int con_set_cmap(unsigned char __user *arg)
4373 {
4374         int i, j, k;
4375         unsigned char colormap[3*16];
4376
4377         if (copy_from_user(colormap, arg, sizeof(colormap)))
4378                 return -EFAULT;
4379
4380         console_lock();
4381         for (i = k = 0; i < 16; i++) {
4382                 default_red[i] = colormap[k++];
4383                 default_grn[i] = colormap[k++];
4384                 default_blu[i] = colormap[k++];
4385         }
4386         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4387                 if (!vc_cons_allocated(i))
4388                         continue;
4389                 for (j = k = 0; j < 16; j++) {
4390                         vc_cons[i].d->vc_palette[k++] = default_red[j];
4391                         vc_cons[i].d->vc_palette[k++] = default_grn[j];
4392                         vc_cons[i].d->vc_palette[k++] = default_blu[j];
4393                 }
4394                 set_palette(vc_cons[i].d);
4395         }
4396         console_unlock();
4397
4398         return 0;
4399 }
4400
4401 int con_get_cmap(unsigned char __user *arg)
4402 {
4403         int i, k;
4404         unsigned char colormap[3*16];
4405
4406         console_lock();
4407         for (i = k = 0; i < 16; i++) {
4408                 colormap[k++] = default_red[i];
4409                 colormap[k++] = default_grn[i];
4410                 colormap[k++] = default_blu[i];
4411         }
4412         console_unlock();
4413
4414         if (copy_to_user(arg, colormap, sizeof(colormap)))
4415                 return -EFAULT;
4416
4417         return 0;
4418 }
4419
4420 void reset_palette(struct vc_data *vc)
4421 {
4422         int j, k;
4423         for (j=k=0; j<16; j++) {
4424                 vc->vc_palette[k++] = default_red[j];
4425                 vc->vc_palette[k++] = default_grn[j];
4426                 vc->vc_palette[k++] = default_blu[j];
4427         }
4428         set_palette(vc);
4429 }
4430
4431 /*
4432  *  Font switching
4433  *
4434  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4435  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4436  *  depending on width) reserved for each character which is kinda wasty, but
4437  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4438  *  is up to the actual low-level console-driver convert data into its favorite
4439  *  format (maybe we should add a `fontoffset' field to the `display'
4440  *  structure so we won't have to convert the fontdata all the time.
4441  *  /Jes
4442  */
4443
4444 #define max_font_size 65536
4445
4446 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4447 {
4448         struct console_font font;
4449         int rc = -EINVAL;
4450         int c;
4451
4452         if (op->data) {
4453                 font.data = kmalloc(max_font_size, GFP_KERNEL);
4454                 if (!font.data)
4455                         return -ENOMEM;
4456         } else
4457                 font.data = NULL;
4458
4459         console_lock();
4460         if (vc->vc_mode != KD_TEXT)
4461                 rc = -EINVAL;
4462         else if (vc->vc_sw->con_font_get)
4463                 rc = vc->vc_sw->con_font_get(vc, &font);
4464         else
4465                 rc = -ENOSYS;
4466         console_unlock();
4467
4468         if (rc)
4469                 goto out;
4470
4471         c = (font.width+7)/8 * 32 * font.charcount;
4472
4473         if (op->data && font.charcount > op->charcount)
4474                 rc = -ENOSPC;
4475         if (font.width > op->width || font.height > op->height)
4476                 rc = -ENOSPC;
4477         if (rc)
4478                 goto out;
4479
4480         op->height = font.height;
4481         op->width = font.width;
4482         op->charcount = font.charcount;
4483
4484         if (op->data && copy_to_user(op->data, font.data, c))
4485                 rc = -EFAULT;
4486
4487 out:
4488         kfree(font.data);
4489         return rc;
4490 }
4491
4492 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4493 {
4494         struct console_font font;
4495         int rc = -EINVAL;
4496         int size;
4497
4498         if (vc->vc_mode != KD_TEXT)
4499                 return -EINVAL;
4500         if (!op->data)
4501                 return -EINVAL;
4502         if (op->charcount > 512)
4503                 return -EINVAL;
4504         if (op->width <= 0 || op->width > 32 || !op->height || op->height > 32)
4505                 return -EINVAL;
4506         size = (op->width+7)/8 * 32 * op->charcount;
4507         if (size > max_font_size)
4508                 return -ENOSPC;
4509
4510         font.data = memdup_user(op->data, size);
4511         if (IS_ERR(font.data))
4512                 return PTR_ERR(font.data);
4513
4514         font.charcount = op->charcount;
4515         font.width = op->width;
4516         font.height = op->height;
4517
4518         console_lock();
4519         if (vc->vc_mode != KD_TEXT)
4520                 rc = -EINVAL;
4521         else if (vc->vc_sw->con_font_set) {
4522                 if (vc_is_sel(vc))
4523                         clear_selection();
4524                 rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4525         } else
4526                 rc = -ENOSYS;
4527         console_unlock();
4528         kfree(font.data);
4529         return rc;
4530 }
4531
4532 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4533 {
4534         struct console_font font = {.width = op->width, .height = op->height};
4535         char name[MAX_FONT_NAME];
4536         char *s = name;
4537         int rc;
4538
4539
4540         if (!op->data)
4541                 s = NULL;
4542         else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4543                 return -EFAULT;
4544         else
4545                 name[MAX_FONT_NAME - 1] = 0;
4546
4547         console_lock();
4548         if (vc->vc_mode != KD_TEXT) {
4549                 console_unlock();
4550                 return -EINVAL;
4551         }
4552         if (vc->vc_sw->con_font_default) {
4553                 if (vc_is_sel(vc))
4554                         clear_selection();
4555                 rc = vc->vc_sw->con_font_default(vc, &font, s);
4556         } else
4557                 rc = -ENOSYS;
4558         console_unlock();
4559         if (!rc) {
4560                 op->width = font.width;
4561                 op->height = font.height;
4562         }
4563         return rc;
4564 }
4565
4566 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4567 {
4568         switch (op->op) {
4569         case KD_FONT_OP_SET:
4570                 return con_font_set(vc, op);
4571         case KD_FONT_OP_GET:
4572                 return con_font_get(vc, op);
4573         case KD_FONT_OP_SET_DEFAULT:
4574                 return con_font_default(vc, op);
4575         case KD_FONT_OP_COPY:
4576                 /* was buggy and never really used */
4577                 return -EINVAL;
4578         }
4579         return -ENOSYS;
4580 }
4581
4582 /*
4583  *      Interface exported to selection and vcs.
4584  */
4585
4586 /* used by selection */
4587 u16 screen_glyph(struct vc_data *vc, int offset)
4588 {
4589         u16 w = scr_readw(screenpos(vc, offset, 1));
4590         u16 c = w & 0xff;
4591
4592         if (w & vc->vc_hi_font_mask)
4593                 c |= 0x100;
4594         return c;
4595 }
4596 EXPORT_SYMBOL_GPL(screen_glyph);
4597
4598 u32 screen_glyph_unicode(struct vc_data *vc, int n)
4599 {
4600         struct uni_screen *uniscr = get_vc_uniscr(vc);
4601
4602         if (uniscr)
4603                 return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4604         return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4605 }
4606 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4607
4608 /* used by vcs - note the word offset */
4609 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4610 {
4611         return screenpos(vc, 2 * w_offset, viewed);
4612 }
4613 EXPORT_SYMBOL_GPL(screen_pos);
4614
4615 void getconsxy(struct vc_data *vc, unsigned char *p)
4616 {
4617         p[0] = vc->vc_x;
4618         p[1] = vc->vc_y;
4619 }
4620
4621 void putconsxy(struct vc_data *vc, unsigned char *p)
4622 {
4623         hide_cursor(vc);
4624         gotoxy(vc, p[0], p[1]);
4625         set_cursor(vc);
4626 }
4627
4628 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4629 {
4630         if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4631                 return softcursor_original;
4632         return scr_readw(org);
4633 }
4634
4635 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4636 {
4637         scr_writew(val, org);
4638         if ((unsigned long)org == vc->vc_pos) {
4639                 softcursor_original = -1;
4640                 add_softcursor(vc);
4641         }
4642 }
4643
4644 void vcs_scr_updated(struct vc_data *vc)
4645 {
4646         notify_update(vc);
4647 }
4648
4649 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4650                 unsigned int rolled_over, void *base, unsigned int size)
4651 {
4652         unsigned long ubase = (unsigned long)base;
4653         ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4654         ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4655         ptrdiff_t origin = (void *)c->vc_origin - base;
4656         int margin = c->vc_size_row * 4;
4657         int from, wrap, from_off, avail;
4658
4659         /* Turn scrollback off */
4660         if (!lines) {
4661                 c->vc_visible_origin = c->vc_origin;
4662                 return;
4663         }
4664
4665         /* Do we have already enough to allow jumping from 0 to the end? */
4666         if (rolled_over > scr_end + margin) {
4667                 from = scr_end;
4668                 wrap = rolled_over + c->vc_size_row;
4669         } else {
4670                 from = 0;
4671                 wrap = size;
4672         }
4673
4674         from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4675         avail = (origin - from + wrap) % wrap;
4676
4677         /* Only a little piece would be left? Show all incl. the piece! */
4678         if (avail < 2 * margin)
4679                 margin = 0;
4680         if (from_off < margin)
4681                 from_off = 0;
4682         if (from_off > avail - margin)
4683                 from_off = avail;
4684
4685         c->vc_visible_origin = ubase + (from + from_off) % wrap;
4686 }
4687 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4688
4689 /*
4690  *      Visible symbols for modules
4691  */
4692
4693 EXPORT_SYMBOL(color_table);
4694 EXPORT_SYMBOL(default_red);
4695 EXPORT_SYMBOL(default_grn);
4696 EXPORT_SYMBOL(default_blu);
4697 EXPORT_SYMBOL(update_region);
4698 EXPORT_SYMBOL(redraw_screen);
4699 EXPORT_SYMBOL(vc_resize);
4700 EXPORT_SYMBOL(fg_console);
4701 EXPORT_SYMBOL(console_blank_hook);
4702 EXPORT_SYMBOL(console_blanked);
4703 EXPORT_SYMBOL(vc_cons);
4704 EXPORT_SYMBOL(global_cursor_default);
4705 #ifndef VT_SINGLE_DRIVER
4706 EXPORT_SYMBOL(give_up_console);
4707 #endif