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  * <[email protected]>
  19  *
  20  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
  21  * Markus Kuhn, <[email protected]>.
  22  *
  23  * Dynamic allocation of consoles, [email protected], May 1994
  24  * Resizing of consoles, aeb, 940926
  25  *
  26  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
  27  * <[email protected]>
  28  *
  29  * User-defined bell sound, new setterm control sequences and printk
  30  * redirection by Martin Mares <[email protected]> 19-Nov-95
  31  *
  32  * APM screenblank bug fixed Takashi Manabe <[email protected]>
  33  *
  34  * Merge with the abstract console driver by Geert Uytterhoeven
  35  * <[email protected]>, Jan 1997.
  36  *
  37  *   Original m68k console driver modifications by
  38  *
  39  *     - Arno Griffioen <[email protected]>
  40  *     - David Carter <[email protected]>
  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 <[email protected]>, August 1997
  53  *
  54  * Ported to i386 and con_scrolldelta fixed
  55  * by Emmanuel Marty <[email protected]>, April 1998
  56  *
  57  * Resurrected character buffers in videoram plus lots of other trickery
  58  * by Martin Mares <[email protected]>, 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 <[email protected]>, Aug 2006
  72  */
  73
  74 #include <linux/module.h>
  75 #include <linux/types.h>
  76 #include <linux/sched/signal.h>
  77 #include <linux/tty.h>
  78 #include <linux/tty_flip.h>
  79 #include <linux/kernel.h>
  80 #include <linux/string.h>
  81 #include <linux/errno.h>
  82 #include <linux/kd.h>
  83 #include <linux/slab.h>
  84 #include <linux/vmalloc.h>
  85 #include <linux/major.h>
  86 #include <linux/mm.h>
  87 #include <linux/console.h>
  88 #include <linux/init.h>
  89 #include <linux/mutex.h>
  90 #include <linux/vt_kern.h>
  91 #include <linux/selection.h>
  92 #include <linux/tiocl.h>
  93 #include <linux/kbd_kern.h>
  94 #include <linux/consolemap.h>
  95 #include <linux/timer.h>
  96 #include <linux/interrupt.h>
  97 #include <linux/workqueue.h>
  98 #include <linux/pm.h>
  99 #include <linux/font.h>
 100 #include <linux/bitops.h>
 101 #include <linux/notifier.h>
 102 #include <linux/device.h>
 103 #include <linux/io.h>
 104 #include <linux/uaccess.h>
 105 #include <linux/kdb.h>
 106 #include <linux/ctype.h>
 107 #include <linux/bsearch.h>
 108 #include <linux/gcd.h>
 109
 110 #define MAX_NR_CON_DRIVER 16
 111
 112 #define CON_DRIVER_FLAG_MODULE 1
 113 #define CON_DRIVER_FLAG_INIT   2
 114 #define CON_DRIVER_FLAG_ATTR   4
 115 #define CON_DRIVER_FLAG_ZOMBIE 8
 116
 117 struct con_driver {
 118         const struct consw *con;
 119         const char *desc;
 120         struct device *dev;
 121         int node;
 122         int first;
 123         int last;
 124         int flag;
 125 };
 126
 127 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
 128 const struct consw *conswitchp;
 129
 130 /*
 131  * Here is the default bell parameters: 750HZ, 1/8th of a second
 132  */
 133 #define DEFAULT_BELL_PITCH      750
 134 #define DEFAULT_BELL_DURATION   (HZ/8)
 135 #define DEFAULT_CURSOR_BLINK_MS 200
 136
 137 struct vc vc_cons [MAX_NR_CONSOLES];
 138
 139 #ifndef VT_SINGLE_DRIVER
 140 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
 141 #endif
 142
 143 static int con_open(struct tty_struct *, struct file *);
 144 static void vc_init(struct vc_data *vc, unsigned int rows,
 145                     unsigned int cols, int do_clear);
 146 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
 147 static void save_cur(struct vc_data *vc);
 148 static void reset_terminal(struct vc_data *vc, int do_clear);
 149 static void con_flush_chars(struct tty_struct *tty);
 150 static int set_vesa_blanking(char __user *p);
 151 static void set_cursor(struct vc_data *vc);
 152 static void hide_cursor(struct vc_data *vc);
 153 static void console_callback(struct work_struct *ignored);
 154 static void con_driver_unregister_callback(struct work_struct *ignored);
 155 static void blank_screen_t(struct timer_list *unused);
 156 static void set_palette(struct vc_data *vc);
 157
 158 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 159
 160 static int printable;           /* Is console ready for printing? */
 161 int default_utf8 = true;
 162 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 163 int global_cursor_default = -1;
 164 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
 165
 166 static int cur_default = CUR_UNDERLINE;
 167 module_param(cur_default, int, S_IRUGO | S_IWUSR);
 168
 169 /*
 170  * ignore_poke: don't unblank the screen when things are typed.  This is
 171  * mainly for the privacy of braille terminal users.
 172  */
 173 static int ignore_poke;
 174
 175 int do_poke_blanked_console;
 176 int console_blanked;
 177
 178 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
 179 static int vesa_off_interval;
 180 static int blankinterval;
 181 core_param(consoleblank, blankinterval, int, 0444);
 182
 183 static DECLARE_WORK(console_work, console_callback);
 184 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
 185
 186 /*
 187  * fg_console is the current virtual console,
 188  * last_console is the last used one,
 189  * want_console is the console we want to switch to,
 190  * saved_* variants are for save/restore around kernel debugger enter/leave
 191  */
 192 int fg_console;
 193 int last_console;
 194 int want_console = -1;
 195 static int saved_fg_console;
 196 static int saved_last_console;
 197 static int saved_want_console;
 198 static int saved_vc_mode;
 199 static int saved_console_blanked;
 200
 201 /*
 202  * For each existing display, we have a pointer to console currently visible
 203  * on that display, allowing consoles other than fg_console to be refreshed
 204  * appropriately. Unless the low-level driver supplies its own display_fg
 205  * variable, we use this one for the "master display".
 206  */
 207 static struct vc_data *master_display_fg;
 208
 209 /*
 210  * Unfortunately, we need to delay tty echo when we're currently writing to the
 211  * console since the code is (and always was) not re-entrant, so we schedule
 212  * all flip requests to process context with schedule-task() and run it from
 213  * console_callback().
 214  */
 215
 216 /*
 217  * For the same reason, we defer scrollback to the console callback.
 218  */
 219 static int scrollback_delta;
 220
 221 /*
 222  * Hook so that the power management routines can (un)blank
 223  * the console on our behalf.
 224  */
 225 int (*console_blank_hook)(int);
 226
 227 static DEFINE_TIMER(console_timer, blank_screen_t);
 228 static int blank_state;
 229 static int blank_timer_expired;
 230 enum {
 231         blank_off = 0,
 232         blank_normal_wait,
 233         blank_vesa_wait,
 234 };
 235
 236 /*
 237  * /sys/class/tty/tty0/
 238  *
 239  * the attribute 'active' contains the name of the current vc
 240  * console and it supports poll() to detect vc switches
 241  */
 242 static struct device *tty0dev;
 243
 244 /*
 245  * Notifier list for console events.
 246  */
 247 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
 248
 249 int register_vt_notifier(struct notifier_block *nb)
 250 {
 251         return atomic_notifier_chain_register(&vt_notifier_list, nb);
 252 }
 253 EXPORT_SYMBOL_GPL(register_vt_notifier);
 254
 255 int unregister_vt_notifier(struct notifier_block *nb)
 256 {
 257         return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
 258 }
 259 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
 260
 261 static void notify_write(struct vc_data *vc, unsigned int unicode)
 262 {
 263         struct vt_notifier_param param = { .vc = vc, .c = unicode };
 264         atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
 265 }
 266
 267 static void notify_update(struct vc_data *vc)
 268 {
 269         struct vt_notifier_param param = { .vc = vc };
 270         atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
 271 }
 272 /*
 273  *      Low-Level Functions
 274  */
 275
 276 static inline bool con_is_fg(const struct vc_data *vc)
 277 {
 278         return vc->vc_num == fg_console;
 279 }
 280
 281 static inline bool con_should_update(const struct vc_data *vc)
 282 {
 283         return con_is_visible(vc) && !console_blanked;
 284 }
 285
 286 static inline unsigned short *screenpos(const struct vc_data *vc, int offset,
 287                 bool viewed)
 288 {
 289         unsigned short *p;
 290
 291         if (!viewed)
 292                 p = (unsigned short *)(vc->vc_origin + offset);
 293         else if (!vc->vc_sw->con_screen_pos)
 294                 p = (unsigned short *)(vc->vc_visible_origin + offset);
 295         else
 296                 p = vc->vc_sw->con_screen_pos(vc, offset);
 297         return p;
 298 }
 299
 300 /* Called  from the keyboard irq path.. */
 301 static inline void scrolldelta(int lines)
 302 {
 303         /* FIXME */
 304         /* scrolldelta needs some kind of consistency lock, but the BKL was
 305            and still is not protecting versus the scheduled back end */
 306         scrollback_delta += lines;
 307         schedule_console_callback();
 308 }
 309
 310 void schedule_console_callback(void)
 311 {
 312         schedule_work(&console_work);
 313 }
 314
 315 /*
 316  * Code to manage unicode-based screen buffers
 317  */
 318
 319 #ifdef NO_VC_UNI_SCREEN
 320 /* this disables and optimizes related code away at compile time */
 321 #define get_vc_uniscr(vc) NULL
 322 #else
 323 #define get_vc_uniscr(vc) vc->vc_uni_screen
 324 #endif
 325
 326 #define VC_UNI_SCREEN_DEBUG 0
 327
 328 typedef uint32_t char32_t;
 329
 330 /*
 331  * Our screen buffer is preceded by an array of line pointers so that
 332  * scrolling only implies some pointer shuffling.
 333  */
 334 struct uni_screen {
 335         char32_t *lines[0];
 336 };
 337
 338 static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
 339 {
 340         struct uni_screen *uniscr;
 341         void *p;
 342         unsigned int memsize, i;
 343
 344         /* allocate everything in one go */
 345         memsize = cols * rows * sizeof(char32_t);
 346         memsize += rows * sizeof(char32_t *);
 347         p = vzalloc(memsize);
 348         if (!p)
 349                 return NULL;
 350
 351         /* initial line pointers */
 352         uniscr = p;
 353         p = uniscr->lines + rows;
 354         for (i = 0; i < rows; i++) {
 355                 uniscr->lines[i] = p;
 356                 p += cols * sizeof(char32_t);
 357         }
 358         return uniscr;
 359 }
 360
 361 static void vc_uniscr_free(struct uni_screen *uniscr)
 362 {
 363         vfree(uniscr);
 364 }
 365
 366 static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
 367 {
 368         vc_uniscr_free(vc->vc_uni_screen);
 369         vc->vc_uni_screen = new_uniscr;
 370 }
 371
 372 static void vc_uniscr_putc(struct vc_data *vc, char32_t uc)
 373 {
 374         struct uni_screen *uniscr = get_vc_uniscr(vc);
 375
 376         if (uniscr)
 377                 uniscr->lines[vc->state.y][vc->state.x] = uc;
 378 }
 379
 380 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
 381 {
 382         struct uni_screen *uniscr = get_vc_uniscr(vc);
 383
 384         if (uniscr) {
 385                 char32_t *ln = uniscr->lines[vc->state.y];
 386                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 387
 388                 memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
 389                 memset32(&ln[x], ' ', nr);
 390         }
 391 }
 392
 393 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
 394 {
 395         struct uni_screen *uniscr = get_vc_uniscr(vc);
 396
 397         if (uniscr) {
 398                 char32_t *ln = uniscr->lines[vc->state.y];
 399                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 400
 401                 memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
 402                 memset32(&ln[cols - nr], ' ', nr);
 403         }
 404 }
 405
 406 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
 407                                  unsigned int nr)
 408 {
 409         struct uni_screen *uniscr = get_vc_uniscr(vc);
 410
 411         if (uniscr) {
 412                 char32_t *ln = uniscr->lines[vc->state.y];
 413
 414                 memset32(&ln[x], ' ', nr);
 415         }
 416 }
 417
 418 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
 419                                   unsigned int nr)
 420 {
 421         struct uni_screen *uniscr = get_vc_uniscr(vc);
 422
 423         if (uniscr) {
 424                 unsigned int cols = vc->vc_cols;
 425
 426                 while (nr--)
 427                         memset32(uniscr->lines[y++], ' ', cols);
 428         }
 429 }
 430
 431 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 432                              enum con_scroll dir, unsigned int nr)
 433 {
 434         struct uni_screen *uniscr = get_vc_uniscr(vc);
 435
 436         if (uniscr) {
 437                 unsigned int i, j, k, sz, d, clear;
 438
 439                 sz = b - t;
 440                 clear = b - nr;
 441                 d = nr;
 442                 if (dir == SM_DOWN) {
 443                         clear = t;
 444                         d = sz - nr;
 445                 }
 446                 for (i = 0; i < gcd(d, sz); i++) {
 447                         char32_t *tmp = uniscr->lines[t + i];
 448                         j = i;
 449                         while (1) {
 450                                 k = j + d;
 451                                 if (k >= sz)
 452                                         k -= sz;
 453                                 if (k == i)
 454                                         break;
 455                                 uniscr->lines[t + j] = uniscr->lines[t + k];
 456                                 j = k;
 457                         }
 458                         uniscr->lines[t + j] = tmp;
 459                 }
 460                 vc_uniscr_clear_lines(vc, clear, nr);
 461         }
 462 }
 463
 464 static void vc_uniscr_copy_area(struct uni_screen *dst,
 465                                 unsigned int dst_cols,
 466                                 unsigned int dst_rows,
 467                                 struct uni_screen *src,
 468                                 unsigned int src_cols,
 469                                 unsigned int src_top_row,
 470                                 unsigned int src_bot_row)
 471 {
 472         unsigned int dst_row = 0;
 473
 474         if (!dst)
 475                 return;
 476
 477         while (src_top_row < src_bot_row) {
 478                 char32_t *src_line = src->lines[src_top_row];
 479                 char32_t *dst_line = dst->lines[dst_row];
 480
 481                 memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
 482                 if (dst_cols - src_cols)
 483                         memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
 484                 src_top_row++;
 485                 dst_row++;
 486         }
 487         while (dst_row < dst_rows) {
 488                 char32_t *dst_line = dst->lines[dst_row];
 489
 490                 memset32(dst_line, ' ', dst_cols);
 491                 dst_row++;
 492         }
 493 }
 494
 495 /*
 496  * Called from vcs_read() to make sure unicode screen retrieval is possible.
 497  * This will initialize the unicode screen buffer if not already done.
 498  * This returns 0 if OK, or a negative error code otherwise.
 499  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
 500  */
 501 int vc_uniscr_check(struct vc_data *vc)
 502 {
 503         struct uni_screen *uniscr;
 504         unsigned short *p;
 505         int x, y, mask;
 506
 507         if (__is_defined(NO_VC_UNI_SCREEN))
 508                 return -EOPNOTSUPP;
 509
 510         WARN_CONSOLE_UNLOCKED();
 511
 512         if (!vc->vc_utf)
 513                 return -ENODATA;
 514
 515         if (vc->vc_uni_screen)
 516                 return 0;
 517
 518         uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
 519         if (!uniscr)
 520                 return -ENOMEM;
 521
 522         /*
 523          * Let's populate it initially with (imperfect) reverse translation.
 524          * This is the next best thing we can do short of having it enabled
 525          * from the start even when no users rely on this functionality. True
 526          * unicode content will be available after a complete screen refresh.
 527          */
 528         p = (unsigned short *)vc->vc_origin;
 529         mask = vc->vc_hi_font_mask | 0xff;
 530         for (y = 0; y < vc->vc_rows; y++) {
 531                 char32_t *line = uniscr->lines[y];
 532                 for (x = 0; x < vc->vc_cols; x++) {
 533                         u16 glyph = scr_readw(p++) & mask;
 534                         line[x] = inverse_translate(vc, glyph, true);
 535                 }
 536         }
 537
 538         vc->vc_uni_screen = uniscr;
 539         return 0;
 540 }
 541
 542 /*
 543  * Called from vcs_read() to get the unicode data from the screen.
 544  * This must be preceded by a successful call to vc_uniscr_check() once
 545  * the console lock has been taken.
 546  */
 547 void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed,
 548                          unsigned int row, unsigned int col, unsigned int nr)
 549 {
 550         struct uni_screen *uniscr = get_vc_uniscr(vc);
 551         int offset = row * vc->vc_size_row + col * 2;
 552         unsigned long pos;
 553
 554         BUG_ON(!uniscr);
 555
 556         pos = (unsigned long)screenpos(vc, offset, viewed);
 557         if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
 558                 /*
 559                  * Desired position falls in the main screen buffer.
 560                  * However the actual row/col might be different if
 561                  * scrollback is active.
 562                  */
 563                 row = (pos - vc->vc_origin) / vc->vc_size_row;
 564                 col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
 565                 memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t));
 566         } else {
 567                 /*
 568                  * Scrollback is active. For now let's simply backtranslate
 569                  * the screen glyphs until the unicode screen buffer does
 570                  * synchronize with console display drivers for a scrollback
 571                  * buffer of its own.
 572                  */
 573                 u16 *p = (u16 *)pos;
 574                 int mask = vc->vc_hi_font_mask | 0xff;
 575                 char32_t *uni_buf = dest;
 576                 while (nr--) {
 577                         u16 glyph = scr_readw(p++) & mask;
 578                         *uni_buf++ = inverse_translate(vc, glyph, true);
 579                 }
 580         }
 581 }
 582
 583 /* this is for validation and debugging only */
 584 static void vc_uniscr_debug_check(struct vc_data *vc)
 585 {
 586         struct uni_screen *uniscr = get_vc_uniscr(vc);
 587         unsigned short *p;
 588         int x, y, mask;
 589
 590         if (!VC_UNI_SCREEN_DEBUG || !uniscr)
 591                 return;
 592
 593         WARN_CONSOLE_UNLOCKED();
 594
 595         /*
 596          * Make sure our unicode screen translates into the same glyphs
 597          * as the actual screen. This is brutal indeed.
 598          */
 599         p = (unsigned short *)vc->vc_origin;
 600         mask = vc->vc_hi_font_mask | 0xff;
 601         for (y = 0; y < vc->vc_rows; y++) {
 602                 char32_t *line = uniscr->lines[y];
 603                 for (x = 0; x < vc->vc_cols; x++) {
 604                         u16 glyph = scr_readw(p++) & mask;
 605                         char32_t uc = line[x];
 606                         int tc = conv_uni_to_pc(vc, uc);
 607                         if (tc == -4)
 608                                 tc = conv_uni_to_pc(vc, 0xfffd);
 609                         if (tc == -4)
 610                                 tc = conv_uni_to_pc(vc, '?');
 611                         if (tc != glyph)
 612                                 pr_err_ratelimited(
 613                                         "%s: mismatch at %d,%d: glyph=%#x tc=%#x\n",
 614                                         __func__, x, y, glyph, tc);
 615                 }
 616         }
 617 }
 618
 619
 620 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 621                 enum con_scroll dir, unsigned int nr)
 622 {
 623         u16 *clear, *d, *s;
 624
 625         if (t + nr >= b)
 626                 nr = b - t - 1;
 627         if (b > vc->vc_rows || t >= b || nr < 1)
 628                 return;
 629         vc_uniscr_scroll(vc, t, b, dir, nr);
 630         if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
 631                 return;
 632
 633         s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
 634         d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
 635
 636         if (dir == SM_UP) {
 637                 clear = s + (b - t - nr) * vc->vc_cols;
 638                 swap(s, d);
 639         }
 640         scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
 641         scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
 642 }
 643
 644 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 645 {
 646         unsigned int xx, yy, offset;
 647         u16 *p;
 648
 649         p = (u16 *) start;
 650         if (!vc->vc_sw->con_getxy) {
 651                 offset = (start - vc->vc_origin) / 2;
 652                 xx = offset % vc->vc_cols;
 653                 yy = offset / vc->vc_cols;
 654         } else {
 655                 int nxx, nyy;
 656                 start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
 657                 xx = nxx; yy = nyy;
 658         }
 659         for(;;) {
 660                 u16 attrib = scr_readw(p) & 0xff00;
 661                 int startx = xx;
 662                 u16 *q = p;
 663                 while (xx < vc->vc_cols && count) {
 664                         if (attrib != (scr_readw(p) & 0xff00)) {
 665                                 if (p > q)
 666                                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 667                                 startx = xx;
 668                                 q = p;
 669                                 attrib = scr_readw(p) & 0xff00;
 670                         }
 671                         p++;
 672                         xx++;
 673                         count--;
 674                 }
 675                 if (p > q)
 676                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 677                 if (!count)
 678                         break;
 679                 xx = 0;
 680                 yy++;
 681                 if (vc->vc_sw->con_getxy) {
 682                         p = (u16 *)start;
 683                         start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
 684                 }
 685         }
 686 }
 687
 688 void update_region(struct vc_data *vc, unsigned long start, int count)
 689 {
 690         WARN_CONSOLE_UNLOCKED();
 691
 692         if (con_should_update(vc)) {
 693                 hide_cursor(vc);
 694                 do_update_region(vc, start, count);
 695                 set_cursor(vc);
 696         }
 697 }
 698
 699 /* Structure of attributes is hardware-dependent */
 700
 701 static u8 build_attr(struct vc_data *vc, u8 _color,
 702                 enum vc_intensity _intensity, bool _blink, bool _underline,
 703                 bool _reverse, bool _italic)
 704 {
 705         if (vc->vc_sw->con_build_attr)
 706                 return vc->vc_sw->con_build_attr(vc, _color, _intensity,
 707                        _blink, _underline, _reverse, _italic);
 708
 709 /*
 710  * ++roman: I completely changed the attribute format for monochrome
 711  * mode (!can_do_color). The formerly used MDA (monochrome display
 712  * adapter) format didn't allow the combination of certain effects.
 713  * Now the attribute is just a bit vector:
 714  *  Bit 0..1: intensity (0..2)
 715  *  Bit 2   : underline
 716  *  Bit 3   : reverse
 717  *  Bit 7   : blink
 718  */
 719         {
 720         u8 a = _color;
 721         if (!vc->vc_can_do_color)
 722                 return _intensity |
 723                        (_italic    << 1) |
 724                        (_underline << 2) |
 725                        (_reverse   << 3) |
 726                        (_blink     << 7);
 727         if (_italic)
 728                 a = (a & 0xF0) | vc->vc_itcolor;
 729         else if (_underline)
 730                 a = (a & 0xf0) | vc->vc_ulcolor;
 731         else if (_intensity == VCI_HALF_BRIGHT)
 732                 a = (a & 0xf0) | vc->vc_halfcolor;
 733         if (_reverse)
 734                 a = (a & 0x88) | (((a >> 4) | (a << 4)) & 0x77);
 735         if (_blink)
 736                 a ^= 0x80;
 737         if (_intensity == VCI_BOLD)
 738                 a ^= 0x08;
 739         if (vc->vc_hi_font_mask == 0x100)
 740                 a <<= 1;
 741         return a;
 742         }
 743 }
 744
 745 static void update_attr(struct vc_data *vc)
 746 {
 747         vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
 748                       vc->state.blink, vc->state.underline,
 749                       vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
 750         vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
 751                                 VCI_NORMAL, vc->state.blink, false,
 752                                 vc->vc_decscnm, false) << 8);
 753 }
 754
 755 /* Note: inverting the screen twice should revert to the original state */
 756 void invert_screen(struct vc_data *vc, int offset, int count, bool viewed)
 757 {
 758         unsigned short *p;
 759
 760         WARN_CONSOLE_UNLOCKED();
 761
 762         count /= 2;
 763         p = screenpos(vc, offset, viewed);
 764         if (vc->vc_sw->con_invert_region) {
 765                 vc->vc_sw->con_invert_region(vc, p, count);
 766         } else {
 767                 u16 *q = p;
 768                 int cnt = count;
 769                 u16 a;
 770
 771                 if (!vc->vc_can_do_color) {
 772                         while (cnt--) {
 773                             a = scr_readw(q);
 774                             a ^= 0x0800;
 775                             scr_writew(a, q);
 776                             q++;
 777                         }
 778                 } else if (vc->vc_hi_font_mask == 0x100) {
 779                         while (cnt--) {
 780                                 a = scr_readw(q);
 781                                 a = (a & 0x11ff) |
 782                                    ((a & 0xe000) >> 4) |
 783                                    ((a & 0x0e00) << 4);
 784                                 scr_writew(a, q);
 785                                 q++;
 786                         }
 787                 } else {
 788                         while (cnt--) {
 789                                 a = scr_readw(q);
 790                                 a = (a & 0x88ff) |
 791                                    ((a & 0x7000) >> 4) |
 792                                    ((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, true));
 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, true);
 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->state.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->state.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_memmovew(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
 859         scr_memsetw(p + vc->vc_cols - vc->state.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->state.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 & CUR_SW))
 875                 return;
 876         if (softcursor_original != -1)
 877                 return;
 878         softcursor_original = i;
 879         i |= CUR_SET(type);
 880         i ^= CUR_CHANGE(type);
 881         if ((type & CUR_ALWAYS_BG) &&
 882                         (softcursor_original & CUR_BG) == (i & CUR_BG))
 883                 i ^= CUR_BG;
 884         if ((type & CUR_INVERT_FG_BG) && (i & CUR_FG) == ((i & CUR_BG) >> 4))
 885                 i ^= CUR_FG;
 886         scr_writew(i, (u16 *)vc->vc_pos);
 887         if (con_should_update(vc))
 888                 vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
 889 }
 890
 891 static void hide_softcursor(struct vc_data *vc)
 892 {
 893         if (softcursor_original != -1) {
 894                 scr_writew(softcursor_original, (u16 *)vc->vc_pos);
 895                 if (con_should_update(vc))
 896                         vc->vc_sw->con_putc(vc, softcursor_original,
 897                                         vc->state.y, vc->state.x);
 898                 softcursor_original = -1;
 899         }
 900 }
 901
 902 static void hide_cursor(struct vc_data *vc)
 903 {
 904         if (vc_is_sel(vc))
 905                 clear_selection();
 906
 907         vc->vc_sw->con_cursor(vc, CM_ERASE);
 908         hide_softcursor(vc);
 909 }
 910
 911 static void set_cursor(struct vc_data *vc)
 912 {
 913         if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
 914                 return;
 915         if (vc->vc_deccm) {
 916                 if (vc_is_sel(vc))
 917                         clear_selection();
 918                 add_softcursor(vc);
 919                 if (CUR_SIZE(vc->vc_cursor_type) != CUR_NONE)
 920                         vc->vc_sw->con_cursor(vc, CM_DRAW);
 921         } else
 922                 hide_cursor(vc);
 923 }
 924
 925 static void set_origin(struct vc_data *vc)
 926 {
 927         WARN_CONSOLE_UNLOCKED();
 928
 929         if (!con_is_visible(vc) ||
 930             !vc->vc_sw->con_set_origin ||
 931             !vc->vc_sw->con_set_origin(vc))
 932                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
 933         vc->vc_visible_origin = vc->vc_origin;
 934         vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
 935         vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->state.y +
 936                 2 * vc->state.x;
 937 }
 938
 939 static void save_screen(struct vc_data *vc)
 940 {
 941         WARN_CONSOLE_UNLOCKED();
 942
 943         if (vc->vc_sw->con_save_screen)
 944                 vc->vc_sw->con_save_screen(vc);
 945 }
 946
 947 static void flush_scrollback(struct vc_data *vc)
 948 {
 949         WARN_CONSOLE_UNLOCKED();
 950
 951         set_origin(vc);
 952         if (vc->vc_sw->con_flush_scrollback) {
 953                 vc->vc_sw->con_flush_scrollback(vc);
 954         } else if (con_is_visible(vc)) {
 955                 /*
 956                  * When no con_flush_scrollback method is provided then the
 957                  * legacy way for flushing the scrollback buffer is to use
 958                  * a side effect of the con_switch method. We do it only on
 959                  * the foreground console as background consoles have no
 960                  * scrollback buffers in that case and we obviously don't
 961                  * want to switch to them.
 962                  */
 963                 hide_cursor(vc);
 964                 vc->vc_sw->con_switch(vc);
 965                 set_cursor(vc);
 966         }
 967 }
 968
 969 /*
 970  *      Redrawing of screen
 971  */
 972
 973 void clear_buffer_attributes(struct vc_data *vc)
 974 {
 975         unsigned short *p = (unsigned short *)vc->vc_origin;
 976         int count = vc->vc_screenbuf_size / 2;
 977         int mask = vc->vc_hi_font_mask | 0xff;
 978
 979         for (; count > 0; count--, p++) {
 980                 scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
 981         }
 982 }
 983
 984 void redraw_screen(struct vc_data *vc, int is_switch)
 985 {
 986         int redraw = 0;
 987
 988         WARN_CONSOLE_UNLOCKED();
 989
 990         if (!vc) {
 991                 /* strange ... */
 992                 /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
 993                 return;
 994         }
 995
 996         if (is_switch) {
 997                 struct vc_data *old_vc = vc_cons[fg_console].d;
 998                 if (old_vc == vc)
 999                         return;
1000                 if (!con_is_visible(vc))
1001                         redraw = 1;
1002                 *vc->vc_display_fg = vc;
1003                 fg_console = vc->vc_num;
1004                 hide_cursor(old_vc);
1005                 if (!con_is_visible(old_vc)) {
1006                         save_screen(old_vc);
1007                         set_origin(old_vc);
1008                 }
1009                 if (tty0dev)
1010                         sysfs_notify(&tty0dev->kobj, NULL, "active");
1011         } else {
1012                 hide_cursor(vc);
1013                 redraw = 1;
1014         }
1015
1016         if (redraw) {
1017                 int update;
1018                 int old_was_color = vc->vc_can_do_color;
1019
1020                 set_origin(vc);
1021                 update = vc->vc_sw->con_switch(vc);
1022                 set_palette(vc);
1023                 /*
1024                  * If console changed from mono<->color, the best we can do
1025                  * is to clear the buffer attributes. As it currently stands,
1026                  * rebuilding new attributes from the old buffer is not doable
1027                  * without overly complex code.
1028                  */
1029                 if (old_was_color != vc->vc_can_do_color) {
1030                         update_attr(vc);
1031                         clear_buffer_attributes(vc);
1032                 }
1033
1034                 if (update && vc->vc_mode != KD_GRAPHICS)
1035                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1036         }
1037         set_cursor(vc);
1038         if (is_switch) {
1039                 vt_set_leds_compute_shiftstate();
1040                 notify_update(vc);
1041         }
1042 }
1043
1044 /*
1045  *      Allocation, freeing and resizing of VTs.
1046  */
1047
1048 int vc_cons_allocated(unsigned int i)
1049 {
1050         return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1051 }
1052
1053 static void visual_init(struct vc_data *vc, int num, int init)
1054 {
1055         /* ++Geert: vc->vc_sw->con_init determines console size */
1056         if (vc->vc_sw)
1057                 module_put(vc->vc_sw->owner);
1058         vc->vc_sw = conswitchp;
1059 #ifndef VT_SINGLE_DRIVER
1060         if (con_driver_map[num])
1061                 vc->vc_sw = con_driver_map[num];
1062 #endif
1063         __module_get(vc->vc_sw->owner);
1064         vc->vc_num = num;
1065         vc->vc_display_fg = &master_display_fg;
1066         if (vc->uni_pagedict_loc)
1067                 con_free_unimap(vc);
1068         vc->uni_pagedict_loc = &vc->uni_pagedict;
1069         vc->uni_pagedict = NULL;
1070         vc->vc_hi_font_mask = 0;
1071         vc->vc_complement_mask = 0;
1072         vc->vc_can_do_color = 0;
1073         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1074         vc->vc_sw->con_init(vc, init);
1075         if (!vc->vc_complement_mask)
1076                 vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1077         vc->vc_s_complement_mask = vc->vc_complement_mask;
1078         vc->vc_size_row = vc->vc_cols << 1;
1079         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1080 }
1081
1082
1083 static void visual_deinit(struct vc_data *vc)
1084 {
1085         vc->vc_sw->con_deinit(vc);
1086         module_put(vc->vc_sw->owner);
1087 }
1088
1089 static void vc_port_destruct(struct tty_port *port)
1090 {
1091         struct vc_data *vc = container_of(port, struct vc_data, port);
1092
1093         kfree(vc);
1094 }
1095
1096 static const struct tty_port_operations vc_port_ops = {
1097         .destruct = vc_port_destruct,
1098 };
1099
1100 /*
1101  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1102  * [this is to be used together with some user program
1103  * like resize that changes the hardware videomode]
1104  */
1105 #define VC_MAXCOL (32767)
1106 #define VC_MAXROW (32767)
1107
1108 int vc_allocate(unsigned int currcons)  /* return 0 on success */
1109 {
1110         struct vt_notifier_param param;
1111         struct vc_data *vc;
1112         int err;
1113
1114         WARN_CONSOLE_UNLOCKED();
1115
1116         if (currcons >= MAX_NR_CONSOLES)
1117                 return -ENXIO;
1118
1119         if (vc_cons[currcons].d)
1120                 return 0;
1121
1122         /* due to the granularity of kmalloc, we waste some memory here */
1123         /* the alloc is done in two steps, to optimize the common situation
1124            of a 25x80 console (structsize=216, screenbuf_size=4000) */
1125         /* although the numbers above are not valid since long ago, the
1126            point is still up-to-date and the comment still has its value
1127            even if only as a historical artifact.  --mj, July 1998 */
1128         param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1129         if (!vc)
1130                 return -ENOMEM;
1131
1132         vc_cons[currcons].d = vc;
1133         tty_port_init(&vc->port);
1134         vc->port.ops = &vc_port_ops;
1135         INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1136
1137         visual_init(vc, currcons, 1);
1138
1139         if (!*vc->uni_pagedict_loc)
1140                 con_set_default_unimap(vc);
1141
1142         err = -EINVAL;
1143         if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
1144             vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
1145                 goto err_free;
1146         err = -ENOMEM;
1147         vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1148         if (!vc->vc_screenbuf)
1149                 goto err_free;
1150
1151         /* If no drivers have overridden us and the user didn't pass a
1152            boot option, default to displaying the cursor */
1153         if (global_cursor_default == -1)
1154                 global_cursor_default = 1;
1155
1156         vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
1157         vcs_make_sysfs(currcons);
1158         atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1159
1160         return 0;
1161 err_free:
1162         visual_deinit(vc);
1163         kfree(vc);
1164         vc_cons[currcons].d = NULL;
1165         return err;
1166 }
1167
1168 static inline int resize_screen(struct vc_data *vc, int width, int height,
1169                                 int user)
1170 {
1171         /* Resizes the resolution of the display adapater */
1172         int err = 0;
1173
1174         if (vc->vc_sw->con_resize)
1175                 err = vc->vc_sw->con_resize(vc, width, height, user);
1176
1177         return err;
1178 }
1179
1180 /**
1181  *      vc_do_resize    -       resizing method for the tty
1182  *      @tty: tty being resized
1183  *      @vc: virtual console private data
1184  *      @cols: columns
1185  *      @lines: lines
1186  *
1187  *      Resize a virtual console, clipping according to the actual constraints.
1188  *      If the caller passes a tty structure then update the termios winsize
1189  *      information and perform any necessary signal handling.
1190  *
1191  *      Caller must hold the console semaphore. Takes the termios rwsem and
1192  *      ctrl.lock of the tty IFF a tty is passed.
1193  */
1194
1195 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1196                                 unsigned int cols, unsigned int lines)
1197 {
1198         unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1199         unsigned long end;
1200         unsigned int old_rows, old_row_size, first_copied_row;
1201         unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1202         unsigned int user;
1203         unsigned short *oldscreen, *newscreen;
1204         struct uni_screen *new_uniscr = NULL;
1205
1206         WARN_CONSOLE_UNLOCKED();
1207
1208         if (!vc)
1209                 return -ENXIO;
1210
1211         user = vc->vc_resize_user;
1212         vc->vc_resize_user = 0;
1213
1214         if (cols > VC_MAXCOL || lines > VC_MAXROW)
1215                 return -EINVAL;
1216
1217         new_cols = (cols ? cols : vc->vc_cols);
1218         new_rows = (lines ? lines : vc->vc_rows);
1219         new_row_size = new_cols << 1;
1220         new_screen_size = new_row_size * new_rows;
1221
1222         if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) {
1223                 /*
1224                  * This function is being called here to cover the case
1225                  * where the userspace calls the FBIOPUT_VSCREENINFO twice,
1226                  * passing the same fb_var_screeninfo containing the fields
1227                  * yres/xres equal to a number non-multiple of vc_font.height
1228                  * and yres_virtual/xres_virtual equal to number lesser than the
1229                  * vc_font.height and yres/xres.
1230                  * In the second call, the struct fb_var_screeninfo isn't
1231                  * being modified by the underlying driver because of the
1232                  * if above, and this causes the fbcon_display->vrows to become
1233                  * negative and it eventually leads to out-of-bound
1234                  * access by the imageblit function.
1235                  * To give the correct values to the struct and to not have
1236                  * to deal with possible errors from the code below, we call
1237                  * the resize_screen here as well.
1238                  */
1239                 return resize_screen(vc, new_cols, new_rows, user);
1240         }
1241
1242         if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
1243                 return -EINVAL;
1244         newscreen = kzalloc(new_screen_size, GFP_USER);
1245         if (!newscreen)
1246                 return -ENOMEM;
1247
1248         if (get_vc_uniscr(vc)) {
1249                 new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1250                 if (!new_uniscr) {
1251                         kfree(newscreen);
1252                         return -ENOMEM;
1253                 }
1254         }
1255
1256         if (vc_is_sel(vc))
1257                 clear_selection();
1258
1259         old_rows = vc->vc_rows;
1260         old_row_size = vc->vc_size_row;
1261
1262         err = resize_screen(vc, new_cols, new_rows, user);
1263         if (err) {
1264                 kfree(newscreen);
1265                 vc_uniscr_free(new_uniscr);
1266                 return err;
1267         }
1268
1269         vc->vc_rows = new_rows;
1270         vc->vc_cols = new_cols;
1271         vc->vc_size_row = new_row_size;
1272         vc->vc_screenbuf_size = new_screen_size;
1273
1274         rlth = min(old_row_size, new_row_size);
1275         rrem = new_row_size - rlth;
1276         old_origin = vc->vc_origin;
1277         new_origin = (long) newscreen;
1278         new_scr_end = new_origin + new_screen_size;
1279
1280         if (vc->state.y > new_rows) {
1281                 if (old_rows - vc->state.y < new_rows) {
1282                         /*
1283                          * Cursor near the bottom, copy contents from the
1284                          * bottom of buffer
1285                          */
1286                         first_copied_row = (old_rows - new_rows);
1287                 } else {
1288                         /*
1289                          * Cursor is in no man's land, copy 1/2 screenful
1290                          * from the top and bottom of cursor position
1291                          */
1292                         first_copied_row = (vc->state.y - new_rows/2);
1293                 }
1294                 old_origin += first_copied_row * old_row_size;
1295         } else
1296                 first_copied_row = 0;
1297         end = old_origin + old_row_size * min(old_rows, new_rows);
1298
1299         vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1300                             get_vc_uniscr(vc), rlth/2, first_copied_row,
1301                             min(old_rows, new_rows));
1302         vc_uniscr_set(vc, new_uniscr);
1303
1304         update_attr(vc);
1305
1306         while (old_origin < end) {
1307                 scr_memcpyw((unsigned short *) new_origin,
1308                             (unsigned short *) old_origin, rlth);
1309                 if (rrem)
1310                         scr_memsetw((void *)(new_origin + rlth),
1311                                     vc->vc_video_erase_char, rrem);
1312                 old_origin += old_row_size;
1313                 new_origin += new_row_size;
1314         }
1315         if (new_scr_end > new_origin)
1316                 scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1317                             new_scr_end - new_origin);
1318         oldscreen = vc->vc_screenbuf;
1319         vc->vc_screenbuf = newscreen;
1320         vc->vc_screenbuf_size = new_screen_size;
1321         set_origin(vc);
1322         kfree(oldscreen);
1323
1324         /* do part of a reset_terminal() */
1325         vc->vc_top = 0;
1326         vc->vc_bottom = vc->vc_rows;
1327         gotoxy(vc, vc->state.x, vc->state.y);
1328         save_cur(vc);
1329
1330         if (tty) {
1331                 /* Rewrite the requested winsize data with the actual
1332                    resulting sizes */
1333                 struct winsize ws;
1334                 memset(&ws, 0, sizeof(ws));
1335                 ws.ws_row = vc->vc_rows;
1336                 ws.ws_col = vc->vc_cols;
1337                 ws.ws_ypixel = vc->vc_scan_lines;
1338                 tty_do_resize(tty, &ws);
1339         }
1340
1341         if (con_is_visible(vc))
1342                 update_screen(vc);
1343         vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1344         notify_update(vc);
1345         return err;
1346 }
1347
1348 /**
1349  *      vc_resize               -       resize a VT
1350  *      @vc: virtual console
1351  *      @cols: columns
1352  *      @rows: rows
1353  *
1354  *      Resize a virtual console as seen from the console end of things. We
1355  *      use the common vc_do_resize methods to update the structures. The
1356  *      caller must hold the console sem to protect console internals and
1357  *      vc->port.tty
1358  */
1359
1360 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1361 {
1362         return vc_do_resize(vc->port.tty, vc, cols, rows);
1363 }
1364
1365 /**
1366  *      vt_resize               -       resize a VT
1367  *      @tty: tty to resize
1368  *      @ws: winsize attributes
1369  *
1370  *      Resize a virtual terminal. This is called by the tty layer as we
1371  *      register our own handler for resizing. The mutual helper does all
1372  *      the actual work.
1373  *
1374  *      Takes the console sem and the called methods then take the tty
1375  *      termios_rwsem and the tty ctrl.lock in that order.
1376  */
1377 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1378 {
1379         struct vc_data *vc = tty->driver_data;
1380         int ret;
1381
1382         console_lock();
1383         ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1384         console_unlock();
1385         return ret;
1386 }
1387
1388 struct vc_data *vc_deallocate(unsigned int currcons)
1389 {
1390         struct vc_data *vc = NULL;
1391
1392         WARN_CONSOLE_UNLOCKED();
1393
1394         if (vc_cons_allocated(currcons)) {
1395                 struct vt_notifier_param param;
1396
1397                 param.vc = vc = vc_cons[currcons].d;
1398                 atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1399                 vcs_remove_sysfs(currcons);
1400                 visual_deinit(vc);
1401                 con_free_unimap(vc);
1402                 put_pid(vc->vt_pid);
1403                 vc_uniscr_set(vc, NULL);
1404                 kfree(vc->vc_screenbuf);
1405                 vc_cons[currcons].d = NULL;
1406         }
1407         return vc;
1408 }
1409
1410 /*
1411  *      VT102 emulator
1412  */
1413
1414 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1415
1416 #define set_kbd(vc, x)  vt_set_kbd_mode_bit((vc)->vc_num, (x))
1417 #define clr_kbd(vc, x)  vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1418 #define is_kbd(vc, x)   vt_get_kbd_mode_bit((vc)->vc_num, (x))
1419
1420 #define decarm          VC_REPEAT
1421 #define decckm          VC_CKMODE
1422 #define kbdapplic       VC_APPLIC
1423 #define lnm             VC_CRLF
1424
1425 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1426                                        8,12,10,14, 9,13,11,15 };
1427
1428 /* the default colour table, for VGA+ colour systems */
1429 unsigned char default_red[] = {
1430         0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1431         0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1432 };
1433 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1434
1435 unsigned char default_grn[] = {
1436         0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1437         0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1438 };
1439 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1440
1441 unsigned char default_blu[] = {
1442         0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1443         0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1444 };
1445 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1446
1447 /*
1448  * gotoxy() must verify all boundaries, because the arguments
1449  * might also be negative. If the given position is out of
1450  * bounds, the cursor is placed at the nearest margin.
1451  */
1452 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1453 {
1454         int min_y, max_y;
1455
1456         if (new_x < 0)
1457                 vc->state.x = 0;
1458         else {
1459                 if (new_x >= vc->vc_cols)
1460                         vc->state.x = vc->vc_cols - 1;
1461                 else
1462                         vc->state.x = new_x;
1463         }
1464
1465         if (vc->vc_decom) {
1466                 min_y = vc->vc_top;
1467                 max_y = vc->vc_bottom;
1468         } else {
1469                 min_y = 0;
1470                 max_y = vc->vc_rows;
1471         }
1472         if (new_y < min_y)
1473                 vc->state.y = min_y;
1474         else if (new_y >= max_y)
1475                 vc->state.y = max_y - 1;
1476         else
1477                 vc->state.y = new_y;
1478         vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
1479                 (vc->state.x << 1);
1480         vc->vc_need_wrap = 0;
1481 }
1482
1483 /* for absolute user moves, when decom is set */
1484 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1485 {
1486         gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1487 }
1488
1489 void scrollback(struct vc_data *vc)
1490 {
1491         scrolldelta(-(vc->vc_rows / 2));
1492 }
1493
1494 void scrollfront(struct vc_data *vc, int lines)
1495 {
1496         if (!lines)
1497                 lines = vc->vc_rows / 2;
1498         scrolldelta(lines);
1499 }
1500
1501 static void lf(struct vc_data *vc)
1502 {
1503         /* don't scroll if above bottom of scrolling region, or
1504          * if below scrolling region
1505          */
1506         if (vc->state.y + 1 == vc->vc_bottom)
1507                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1508         else if (vc->state.y < vc->vc_rows - 1) {
1509                 vc->state.y++;
1510                 vc->vc_pos += vc->vc_size_row;
1511         }
1512         vc->vc_need_wrap = 0;
1513         notify_write(vc, '\n');
1514 }
1515
1516 static void ri(struct vc_data *vc)
1517 {
1518         /* don't scroll if below top of scrolling region, or
1519          * if above scrolling region
1520          */
1521         if (vc->state.y == vc->vc_top)
1522                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1523         else if (vc->state.y > 0) {
1524                 vc->state.y--;
1525                 vc->vc_pos -= vc->vc_size_row;
1526         }
1527         vc->vc_need_wrap = 0;
1528 }
1529
1530 static inline void cr(struct vc_data *vc)
1531 {
1532         vc->vc_pos -= vc->state.x << 1;
1533         vc->vc_need_wrap = vc->state.x = 0;
1534         notify_write(vc, '\r');
1535 }
1536
1537 static inline void bs(struct vc_data *vc)
1538 {
1539         if (vc->state.x) {
1540                 vc->vc_pos -= 2;
1541                 vc->state.x--;
1542                 vc->vc_need_wrap = 0;
1543                 notify_write(vc, '\b');
1544         }
1545 }
1546
1547 static inline void del(struct vc_data *vc)
1548 {
1549         /* ignored */
1550 }
1551
1552 static void csi_J(struct vc_data *vc, int vpar)
1553 {
1554         unsigned int count;
1555         unsigned short * start;
1556
1557         switch (vpar) {
1558                 case 0: /* erase from cursor to end of display */
1559                         vc_uniscr_clear_line(vc, vc->state.x,
1560                                              vc->vc_cols - vc->state.x);
1561                         vc_uniscr_clear_lines(vc, vc->state.y + 1,
1562                                               vc->vc_rows - vc->state.y - 1);
1563                         count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1564                         start = (unsigned short *)vc->vc_pos;
1565                         break;
1566                 case 1: /* erase from start to cursor */
1567                         vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
1568                         vc_uniscr_clear_lines(vc, 0, vc->state.y);
1569                         count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1570                         start = (unsigned short *)vc->vc_origin;
1571                         break;
1572                 case 3: /* include scrollback */
1573                         flush_scrollback(vc);
1574                         fallthrough;
1575                 case 2: /* erase whole display */
1576                         vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1577                         count = vc->vc_cols * vc->vc_rows;
1578                         start = (unsigned short *)vc->vc_origin;
1579                         break;
1580                 default:
1581                         return;
1582         }
1583         scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1584         if (con_should_update(vc))
1585                 do_update_region(vc, (unsigned long) start, count);
1586         vc->vc_need_wrap = 0;
1587 }
1588
1589 static void csi_K(struct vc_data *vc, int vpar)
1590 {
1591         unsigned int count;
1592         unsigned short *start = (unsigned short *)vc->vc_pos;
1593         int offset;
1594
1595         switch (vpar) {
1596                 case 0: /* erase from cursor to end of line */
1597                         offset = 0;
1598                         count = vc->vc_cols - vc->state.x;
1599                         break;
1600                 case 1: /* erase from start of line to cursor */
1601                         offset = -vc->state.x;
1602                         count = vc->state.x + 1;
1603                         break;
1604                 case 2: /* erase whole line */
1605                         offset = -vc->state.x;
1606                         count = vc->vc_cols;
1607                         break;
1608                 default:
1609                         return;
1610         }
1611         vc_uniscr_clear_line(vc, vc->state.x + offset, count);
1612         scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1613         vc->vc_need_wrap = 0;
1614         if (con_should_update(vc))
1615                 do_update_region(vc, (unsigned long)(start + offset), count);
1616 }
1617
1618 /* erase the following vpar positions */
1619 static void csi_X(struct vc_data *vc, unsigned int vpar)
1620 {                                         /* not vt100? */
1621         unsigned int count;
1622
1623         if (!vpar)
1624                 vpar++;
1625
1626         count = min(vpar, vc->vc_cols - vc->state.x);
1627
1628         vc_uniscr_clear_line(vc, vc->state.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->state.y, vc->state.x, 1, count);
1632         vc->vc_need_wrap = 0;
1633 }
1634
1635 static void default_attr(struct vc_data *vc)
1636 {
1637         vc->state.intensity = VCI_NORMAL;
1638         vc->state.italic = false;
1639         vc->state.underline = false;
1640         vc->state.reverse = false;
1641         vc->state.blink = false;
1642         vc->state.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->state.intensity = VCI_BOLD;
1679         } else if (max > 0xaa)
1680                 vc->state.intensity = VCI_BOLD;
1681         else
1682                 vc->state.intensity = VCI_NORMAL;
1683
1684         vc->state.color = (vc->state.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->state.color = (vc->state.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. That standard also
1697  * wants : rather than ; as separators but sequences containing : are currently
1698  * completely ignored by the parser.
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->state.intensity = VCI_BOLD;
1742                         break;
1743                 case 2:
1744                         vc->state.intensity = VCI_HALF_BRIGHT;
1745                         break;
1746                 case 3:
1747                         vc->state.italic = true;
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->state.underline = true;
1756                         break;
1757                 case 5:
1758                         vc->state.blink = true;
1759                         break;
1760                 case 7:
1761                         vc->state.reverse = true;
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->state.Gx_charset[vc->state.charset], vc);
1768                         vc->vc_disp_ctrl = 0;
1769                         vc->vc_toggle_meta = 0;
1770                         break;
1771                 case 11: /* ANSI X3.64-1979 (SCO-ish?)
1772                           * Select first alternate font, lets chars < 32 be
1773                           * displayed as ROM chars.
1774                           */
1775                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1776                         vc->vc_disp_ctrl = 1;
1777                         vc->vc_toggle_meta = 0;
1778                         break;
1779                 case 12: /* ANSI X3.64-1979 (SCO-ish?)
1780                           * Select second alternate font, toggle high bit
1781                           * before displaying as ROM char.
1782                           */
1783                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1784                         vc->vc_disp_ctrl = 1;
1785                         vc->vc_toggle_meta = 1;
1786                         break;
1787                 case 22:
1788                         vc->state.intensity = VCI_NORMAL;
1789                         break;
1790                 case 23:
1791                         vc->state.italic = false;
1792                         break;
1793                 case 24:
1794                         vc->state.underline = false;
1795                         break;
1796                 case 25:
1797                         vc->state.blink = false;
1798                         break;
1799                 case 27:
1800                         vc->state.reverse = false;
1801                         break;
1802                 case 38:
1803                         i = vc_t416_color(vc, i, rgb_foreground);
1804                         break;
1805                 case 48:
1806                         i = vc_t416_color(vc, i, rgb_background);
1807                         break;
1808                 case 39:
1809                         vc->state.color = (vc->vc_def_color & 0x0f) |
1810                                 (vc->state.color & 0xf0);
1811                         break;
1812                 case 49:
1813                         vc->state.color = (vc->vc_def_color & 0xf0) |
1814                                 (vc->state.color & 0x0f);
1815                         break;
1816                 default:
1817                         if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1818                                 if (vc->vc_par[i] < 100)
1819                                         vc->state.intensity = VCI_BOLD;
1820                                 vc->vc_par[i] -= 60;
1821                         }
1822                         if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1823                                 vc->state.color = color_table[vc->vc_par[i] - 30]
1824                                         | (vc->state.color & 0xf0);
1825                         else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1826                                 vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
1827                                         | (vc->state.color & 0x0f);
1828                         break;
1829                 }
1830         update_attr(vc);
1831 }
1832
1833 static void respond_string(const char *p, size_t len, struct tty_port *port)
1834 {
1835         tty_insert_flip_string(port, p, len);
1836         tty_flip_buffer_push(port);
1837 }
1838
1839 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1840 {
1841         char buf[40];
1842         int len;
1843
1844         len = sprintf(buf, "\033[%d;%dR", vc->state.y +
1845                         (vc->vc_decom ? vc->vc_top + 1 : 1),
1846                         vc->state.x + 1);
1847         respond_string(buf, len, tty->port);
1848 }
1849
1850 static inline void status_report(struct tty_struct *tty)
1851 {
1852         static const char teminal_ok[] = "\033[0n";
1853
1854         respond_string(teminal_ok, strlen(teminal_ok), tty->port);
1855 }
1856
1857 static inline void respond_ID(struct tty_struct *tty)
1858 {
1859         /* terminal answer to an ESC-Z or csi0c query. */
1860         static const char vt102_id[] = "\033[?6c";
1861
1862         respond_string(vt102_id, strlen(vt102_id), tty->port);
1863 }
1864
1865 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1866 {
1867         char buf[8];
1868         int len;
1869
1870         len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
1871                         (char)('!' + mrx), (char)('!' + mry));
1872         respond_string(buf, len, tty->port);
1873 }
1874
1875 /* invoked via ioctl(TIOCLINUX) and through set_selection_user */
1876 int mouse_reporting(void)
1877 {
1878         return vc_cons[fg_console].d->vc_report_mouse;
1879 }
1880
1881 /* console_lock is held */
1882 static void set_mode(struct vc_data *vc, int on_off)
1883 {
1884         int i;
1885
1886         for (i = 0; i <= vc->vc_npar; i++)
1887                 if (vc->vc_priv == EPdec) {
1888                         switch(vc->vc_par[i]) { /* DEC private modes set/reset */
1889                         case 1:                 /* Cursor keys send ^[Ox/^[[x */
1890                                 if (on_off)
1891                                         set_kbd(vc, decckm);
1892                                 else
1893                                         clr_kbd(vc, decckm);
1894                                 break;
1895                         case 3: /* 80/132 mode switch unimplemented */
1896 #if 0
1897                                 vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1898                                 /* this alone does not suffice; some user mode
1899                                    utility has to change the hardware regs */
1900 #endif
1901                                 break;
1902                         case 5:                 /* Inverted screen on/off */
1903                                 if (vc->vc_decscnm != on_off) {
1904                                         vc->vc_decscnm = on_off;
1905                                         invert_screen(vc, 0,
1906                                                         vc->vc_screenbuf_size,
1907                                                         false);
1908                                         update_attr(vc);
1909                                 }
1910                                 break;
1911                         case 6:                 /* Origin relative/absolute */
1912                                 vc->vc_decom = on_off;
1913                                 gotoxay(vc, 0, 0);
1914                                 break;
1915                         case 7:                 /* Autowrap on/off */
1916                                 vc->vc_decawm = on_off;
1917                                 break;
1918                         case 8:                 /* Autorepeat on/off */
1919                                 if (on_off)
1920                                         set_kbd(vc, decarm);
1921                                 else
1922                                         clr_kbd(vc, decarm);
1923                                 break;
1924                         case 9:
1925                                 vc->vc_report_mouse = on_off ? 1 : 0;
1926                                 break;
1927                         case 25:                /* Cursor on/off */
1928                                 vc->vc_deccm = on_off;
1929                                 break;
1930                         case 1000:
1931                                 vc->vc_report_mouse = on_off ? 2 : 0;
1932                                 break;
1933                         }
1934                 } else {
1935                         switch(vc->vc_par[i]) { /* ANSI modes set/reset */
1936                         case 3:                 /* Monitor (display ctrls) */
1937                                 vc->vc_disp_ctrl = on_off;
1938                                 break;
1939                         case 4:                 /* Insert Mode on/off */
1940                                 vc->vc_decim = on_off;
1941                                 break;
1942                         case 20:                /* Lf, Enter == CrLf/Lf */
1943                                 if (on_off)
1944                                         set_kbd(vc, lnm);
1945                                 else
1946                                         clr_kbd(vc, lnm);
1947                                 break;
1948                         }
1949                 }
1950 }
1951
1952 /* console_lock is held */
1953 static void setterm_command(struct vc_data *vc)
1954 {
1955         switch (vc->vc_par[0]) {
1956         case 1: /* set color for underline mode */
1957                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1958                         vc->vc_ulcolor = color_table[vc->vc_par[1]];
1959                         if (vc->state.underline)
1960                                 update_attr(vc);
1961                 }
1962                 break;
1963         case 2: /* set color for half intensity mode */
1964                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1965                         vc->vc_halfcolor = color_table[vc->vc_par[1]];
1966                         if (vc->state.intensity == VCI_HALF_BRIGHT)
1967                                 update_attr(vc);
1968                 }
1969                 break;
1970         case 8: /* store colors as defaults */
1971                 vc->vc_def_color = vc->vc_attr;
1972                 if (vc->vc_hi_font_mask == 0x100)
1973                         vc->vc_def_color >>= 1;
1974                 default_attr(vc);
1975                 update_attr(vc);
1976                 break;
1977         case 9: /* set blanking interval */
1978                 blankinterval = min(vc->vc_par[1], 60U) * 60;
1979                 poke_blanked_console();
1980                 break;
1981         case 10: /* set bell frequency in Hz */
1982                 if (vc->vc_npar >= 1)
1983                         vc->vc_bell_pitch = vc->vc_par[1];
1984                 else
1985                         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1986                 break;
1987         case 11: /* set bell duration in msec */
1988                 if (vc->vc_npar >= 1)
1989                         vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1990                                 msecs_to_jiffies(vc->vc_par[1]) : 0;
1991                 else
1992                         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1993                 break;
1994         case 12: /* bring specified console to the front */
1995                 if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1996                         set_console(vc->vc_par[1] - 1);
1997                 break;
1998         case 13: /* unblank the screen */
1999                 poke_blanked_console();
2000                 break;
2001         case 14: /* set vesa powerdown interval */
2002                 vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
2003                 break;
2004         case 15: /* activate the previous console */
2005                 set_console(last_console);
2006                 break;
2007         case 16: /* set cursor blink duration in msec */
2008                 if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
2009                                 vc->vc_par[1] <= USHRT_MAX)
2010                         vc->vc_cur_blink_ms = vc->vc_par[1];
2011                 else
2012                         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2013                 break;
2014         }
2015 }
2016
2017 /* console_lock is held */
2018 static void csi_at(struct vc_data *vc, unsigned int nr)
2019 {
2020         if (nr > vc->vc_cols - vc->state.x)
2021                 nr = vc->vc_cols - vc->state.x;
2022         else if (!nr)
2023                 nr = 1;
2024         insert_char(vc, nr);
2025 }
2026
2027 /* console_lock is held */
2028 static void csi_L(struct vc_data *vc, unsigned int nr)
2029 {
2030         if (nr > vc->vc_rows - vc->state.y)
2031                 nr = vc->vc_rows - vc->state.y;
2032         else if (!nr)
2033                 nr = 1;
2034         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
2035         vc->vc_need_wrap = 0;
2036 }
2037
2038 /* console_lock is held */
2039 static void csi_P(struct vc_data *vc, unsigned int nr)
2040 {
2041         if (nr > vc->vc_cols - vc->state.x)
2042                 nr = vc->vc_cols - vc->state.x;
2043         else if (!nr)
2044                 nr = 1;
2045         delete_char(vc, nr);
2046 }
2047
2048 /* console_lock is held */
2049 static void csi_M(struct vc_data *vc, unsigned int nr)
2050 {
2051         if (nr > vc->vc_rows - vc->state.y)
2052                 nr = vc->vc_rows - vc->state.y;
2053         else if (!nr)
2054                 nr=1;
2055         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
2056         vc->vc_need_wrap = 0;
2057 }
2058
2059 /* console_lock is held (except via vc_init->reset_terminal */
2060 static void save_cur(struct vc_data *vc)
2061 {
2062         memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
2063 }
2064
2065 /* console_lock is held */
2066 static void restore_cur(struct vc_data *vc)
2067 {
2068         memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
2069
2070         gotoxy(vc, vc->state.x, vc->state.y);
2071         vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
2072                         vc);
2073         update_attr(vc);
2074         vc->vc_need_wrap = 0;
2075 }
2076
2077 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2078         EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2079         ESpalette, ESosc, ESapc, ESpm, ESdcs };
2080
2081 /* console_lock is held (except via vc_init()) */
2082 static void reset_terminal(struct vc_data *vc, int do_clear)
2083 {
2084         unsigned int i;
2085
2086         vc->vc_top              = 0;
2087         vc->vc_bottom           = vc->vc_rows;
2088         vc->vc_state            = ESnormal;
2089         vc->vc_priv             = EPecma;
2090         vc->vc_translate        = set_translate(LAT1_MAP, vc);
2091         vc->state.Gx_charset[0] = LAT1_MAP;
2092         vc->state.Gx_charset[1] = GRAF_MAP;
2093         vc->state.charset       = 0;
2094         vc->vc_need_wrap        = 0;
2095         vc->vc_report_mouse     = 0;
2096         vc->vc_utf              = default_utf8;
2097         vc->vc_utf_count        = 0;
2098
2099         vc->vc_disp_ctrl        = 0;
2100         vc->vc_toggle_meta      = 0;
2101
2102         vc->vc_decscnm          = 0;
2103         vc->vc_decom            = 0;
2104         vc->vc_decawm           = 1;
2105         vc->vc_deccm            = global_cursor_default;
2106         vc->vc_decim            = 0;
2107
2108         vt_reset_keyboard(vc->vc_num);
2109
2110         vc->vc_cursor_type = cur_default;
2111         vc->vc_complement_mask = vc->vc_s_complement_mask;
2112
2113         default_attr(vc);
2114         update_attr(vc);
2115
2116         bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2117         for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
2118                 set_bit(i, vc->vc_tab_stop);
2119
2120         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2121         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2122         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2123
2124         gotoxy(vc, 0, 0);
2125         save_cur(vc);
2126         if (do_clear)
2127             csi_J(vc, 2);
2128 }
2129
2130 static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
2131 {
2132         unsigned char *charset = &vc->state.Gx_charset[which];
2133
2134         switch (c) {
2135         case '0':
2136                 *charset = GRAF_MAP;
2137                 break;
2138         case 'B':
2139                 *charset = LAT1_MAP;
2140                 break;
2141         case 'U':
2142                 *charset = IBMPC_MAP;
2143                 break;
2144         case 'K':
2145                 *charset = USER_MAP;
2146                 break;
2147         }
2148
2149         if (vc->state.charset == which)
2150                 vc->vc_translate = set_translate(*charset, vc);
2151 }
2152
2153 /* is this state an ANSI control string? */
2154 static bool ansi_control_string(unsigned int state)
2155 {
2156         if (state == ESosc || state == ESapc || state == ESpm || state == ESdcs)
2157                 return true;
2158         return false;
2159 }
2160
2161 /* console_lock is held */
2162 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2163 {
2164         /*
2165          *  Control characters can be used in the _middle_
2166          *  of an escape sequence, aside from ANSI control strings.
2167          */
2168         if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
2169                 return;
2170         switch (c) {
2171         case 0:
2172                 return;
2173         case 7:
2174                 if (ansi_control_string(vc->vc_state))
2175                         vc->vc_state = ESnormal;
2176                 else if (vc->vc_bell_duration)
2177                         kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2178                 return;
2179         case 8:
2180                 bs(vc);
2181                 return;
2182         case 9:
2183                 vc->vc_pos -= (vc->state.x << 1);
2184
2185                 vc->state.x = find_next_bit(vc->vc_tab_stop,
2186                                 min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2187                                 vc->state.x + 1);
2188                 if (vc->state.x >= VC_TABSTOPS_COUNT)
2189                         vc->state.x = vc->vc_cols - 1;
2190
2191                 vc->vc_pos += (vc->state.x << 1);
2192                 notify_write(vc, '\t');
2193                 return;
2194         case 10: case 11: case 12:
2195                 lf(vc);
2196                 if (!is_kbd(vc, lnm))
2197                         return;
2198                 fallthrough;
2199         case 13:
2200                 cr(vc);
2201                 return;
2202         case 14:
2203                 vc->state.charset = 1;
2204                 vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2205                 vc->vc_disp_ctrl = 1;
2206                 return;
2207         case 15:
2208                 vc->state.charset = 0;
2209                 vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2210                 vc->vc_disp_ctrl = 0;
2211                 return;
2212         case 24: case 26:
2213                 vc->vc_state = ESnormal;
2214                 return;
2215         case 27:
2216                 vc->vc_state = ESesc;
2217                 return;
2218         case 127:
2219                 del(vc);
2220                 return;
2221         case 128+27:
2222                 vc->vc_state = ESsquare;
2223                 return;
2224         }
2225         switch(vc->vc_state) {
2226         case ESesc:
2227                 vc->vc_state = ESnormal;
2228                 switch (c) {
2229                 case '[':
2230                         vc->vc_state = ESsquare;
2231                         return;
2232                 case ']':
2233                         vc->vc_state = ESnonstd;
2234                         return;
2235                 case '_':
2236                         vc->vc_state = ESapc;
2237                         return;
2238                 case '^':
2239                         vc->vc_state = ESpm;
2240                         return;
2241                 case '%':
2242                         vc->vc_state = ESpercent;
2243                         return;
2244                 case 'E':
2245                         cr(vc);
2246                         lf(vc);
2247                         return;
2248                 case 'M':
2249                         ri(vc);
2250                         return;
2251                 case 'D':
2252                         lf(vc);
2253                         return;
2254                 case 'H':
2255                         if (vc->state.x < VC_TABSTOPS_COUNT)
2256                                 set_bit(vc->state.x, vc->vc_tab_stop);
2257                         return;
2258                 case 'P':
2259                         vc->vc_state = ESdcs;
2260                         return;
2261                 case 'Z':
2262                         respond_ID(tty);
2263                         return;
2264                 case '7':
2265                         save_cur(vc);
2266                         return;
2267                 case '8':
2268                         restore_cur(vc);
2269                         return;
2270                 case '(':
2271                         vc->vc_state = ESsetG0;
2272                         return;
2273                 case ')':
2274                         vc->vc_state = ESsetG1;
2275                         return;
2276                 case '#':
2277                         vc->vc_state = EShash;
2278                         return;
2279                 case 'c':
2280                         reset_terminal(vc, 1);
2281                         return;
2282                 case '>':  /* Numeric keypad */
2283                         clr_kbd(vc, kbdapplic);
2284                         return;
2285                 case '=':  /* Appl. keypad */
2286                         set_kbd(vc, kbdapplic);
2287                         return;
2288                 }
2289                 return;
2290         case ESnonstd:
2291                 if (c=='P') {   /* palette escape sequence */
2292                         for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2293                                 vc->vc_par[vc->vc_npar] = 0;
2294                         vc->vc_npar = 0;
2295                         vc->vc_state = ESpalette;
2296                         return;
2297                 } else if (c=='R') {   /* reset palette */
2298                         reset_palette(vc);
2299                         vc->vc_state = ESnormal;
2300                 } else if (c>='0' && c<='9')
2301                         vc->vc_state = ESosc;
2302                 else
2303                         vc->vc_state = ESnormal;
2304                 return;
2305         case ESpalette:
2306                 if (isxdigit(c)) {
2307                         vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2308                         if (vc->vc_npar == 7) {
2309                                 int i = vc->vc_par[0] * 3, j = 1;
2310                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2311                                 vc->vc_palette[i++] += vc->vc_par[j++];
2312                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2313                                 vc->vc_palette[i++] += vc->vc_par[j++];
2314                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2315                                 vc->vc_palette[i] += vc->vc_par[j];
2316                                 set_palette(vc);
2317                                 vc->vc_state = ESnormal;
2318                         }
2319                 } else
2320                         vc->vc_state = ESnormal;
2321                 return;
2322         case ESsquare:
2323                 for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2324                         vc->vc_par[vc->vc_npar] = 0;
2325                 vc->vc_npar = 0;
2326                 vc->vc_state = ESgetpars;
2327                 if (c == '[') { /* Function key */
2328                         vc->vc_state=ESfunckey;
2329                         return;
2330                 }
2331                 switch (c) {
2332                 case '?':
2333                         vc->vc_priv = EPdec;
2334                         return;
2335                 case '>':
2336                         vc->vc_priv = EPgt;
2337                         return;
2338                 case '=':
2339                         vc->vc_priv = EPeq;
2340                         return;
2341                 case '<':
2342                         vc->vc_priv = EPlt;
2343                         return;
2344                 }
2345                 vc->vc_priv = EPecma;
2346                 fallthrough;
2347         case ESgetpars:
2348                 if (c == ';' && vc->vc_npar < NPAR - 1) {
2349                         vc->vc_npar++;
2350                         return;
2351                 } else if (c>='0' && c<='9') {
2352                         vc->vc_par[vc->vc_npar] *= 10;
2353                         vc->vc_par[vc->vc_npar] += c - '0';
2354                         return;
2355                 }
2356                 if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2357                         vc->vc_state = EScsiignore;
2358                         return;
2359                 }
2360                 vc->vc_state = ESnormal;
2361                 switch(c) {
2362                 case 'h':
2363                         if (vc->vc_priv <= EPdec)
2364                                 set_mode(vc, 1);
2365                         return;
2366                 case 'l':
2367                         if (vc->vc_priv <= EPdec)
2368                                 set_mode(vc, 0);
2369                         return;
2370                 case 'c':
2371                         if (vc->vc_priv == EPdec) {
2372                                 if (vc->vc_par[0])
2373                                         vc->vc_cursor_type =
2374                                                 CUR_MAKE(vc->vc_par[0],
2375                                                          vc->vc_par[1],
2376                                                          vc->vc_par[2]);
2377                                 else
2378                                         vc->vc_cursor_type = cur_default;
2379                                 return;
2380                         }
2381                         break;
2382                 case 'm':
2383                         if (vc->vc_priv == EPdec) {
2384                                 clear_selection();
2385                                 if (vc->vc_par[0])
2386                                         vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2387                                 else
2388                                         vc->vc_complement_mask = vc->vc_s_complement_mask;
2389                                 return;
2390                         }
2391                         break;
2392                 case 'n':
2393                         if (vc->vc_priv == EPecma) {
2394                                 if (vc->vc_par[0] == 5)
2395                                         status_report(tty);
2396                                 else if (vc->vc_par[0] == 6)
2397                                         cursor_report(vc, tty);
2398                         }
2399                         return;
2400                 }
2401                 if (vc->vc_priv != EPecma) {
2402                         vc->vc_priv = EPecma;
2403                         return;
2404                 }
2405                 switch(c) {
2406                 case 'G': case '`':
2407                         if (vc->vc_par[0])
2408                                 vc->vc_par[0]--;
2409                         gotoxy(vc, vc->vc_par[0], vc->state.y);
2410                         return;
2411                 case 'A':
2412                         if (!vc->vc_par[0])
2413                                 vc->vc_par[0]++;
2414                         gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2415                         return;
2416                 case 'B': case 'e':
2417                         if (!vc->vc_par[0])
2418                                 vc->vc_par[0]++;
2419                         gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2420                         return;
2421                 case 'C': case 'a':
2422                         if (!vc->vc_par[0])
2423                                 vc->vc_par[0]++;
2424                         gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2425                         return;
2426                 case 'D':
2427                         if (!vc->vc_par[0])
2428                                 vc->vc_par[0]++;
2429                         gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2430                         return;
2431                 case 'E':
2432                         if (!vc->vc_par[0])
2433                                 vc->vc_par[0]++;
2434                         gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2435                         return;
2436                 case 'F':
2437                         if (!vc->vc_par[0])
2438                                 vc->vc_par[0]++;
2439                         gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2440                         return;
2441                 case 'd':
2442                         if (vc->vc_par[0])
2443                                 vc->vc_par[0]--;
2444                         gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2445                         return;
2446                 case 'H': case 'f':
2447                         if (vc->vc_par[0])
2448                                 vc->vc_par[0]--;
2449                         if (vc->vc_par[1])
2450                                 vc->vc_par[1]--;
2451                         gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2452                         return;
2453                 case 'J':
2454                         csi_J(vc, vc->vc_par[0]);
2455                         return;
2456                 case 'K':
2457                         csi_K(vc, vc->vc_par[0]);
2458                         return;
2459                 case 'L':
2460                         csi_L(vc, vc->vc_par[0]);
2461                         return;
2462                 case 'M':
2463                         csi_M(vc, vc->vc_par[0]);
2464                         return;
2465                 case 'P':
2466                         csi_P(vc, vc->vc_par[0]);
2467                         return;
2468                 case 'c':
2469                         if (!vc->vc_par[0])
2470                                 respond_ID(tty);
2471                         return;
2472                 case 'g':
2473                         if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2474                                 set_bit(vc->state.x, vc->vc_tab_stop);
2475                         else if (vc->vc_par[0] == 3)
2476                                 bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2477                         return;
2478                 case 'm':
2479                         csi_m(vc);
2480                         return;
2481                 case 'q': /* DECLL - but only 3 leds */
2482                         /* map 0,1,2,3 to 0,1,2,4 */
2483                         if (vc->vc_par[0] < 4)
2484                                 vt_set_led_state(vc->vc_num,
2485                                             (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2486                         return;
2487                 case 'r':
2488                         if (!vc->vc_par[0])
2489                                 vc->vc_par[0]++;
2490                         if (!vc->vc_par[1])
2491                                 vc->vc_par[1] = vc->vc_rows;
2492                         /* Minimum allowed region is 2 lines */
2493                         if (vc->vc_par[0] < vc->vc_par[1] &&
2494                             vc->vc_par[1] <= vc->vc_rows) {
2495                                 vc->vc_top = vc->vc_par[0] - 1;
2496                                 vc->vc_bottom = vc->vc_par[1];
2497                                 gotoxay(vc, 0, 0);
2498                         }
2499                         return;
2500                 case 's':
2501                         save_cur(vc);
2502                         return;
2503                 case 'u':
2504                         restore_cur(vc);
2505                         return;
2506                 case 'X':
2507                         csi_X(vc, vc->vc_par[0]);
2508                         return;
2509                 case '@':
2510                         csi_at(vc, vc->vc_par[0]);
2511                         return;
2512                 case ']': /* setterm functions */
2513                         setterm_command(vc);
2514                         return;
2515                 }
2516                 return;
2517         case EScsiignore:
2518                 if (c >= 20 && c <= 0x3f)
2519                         return;
2520                 vc->vc_state = ESnormal;
2521                 return;
2522         case ESpercent:
2523                 vc->vc_state = ESnormal;
2524                 switch (c) {
2525                 case '@':  /* defined in ISO 2022 */
2526                         vc->vc_utf = 0;
2527                         return;
2528                 case 'G':  /* prelim official escape code */
2529                 case '8':  /* retained for compatibility */
2530                         vc->vc_utf = 1;
2531                         return;
2532                 }
2533                 return;
2534         case ESfunckey:
2535                 vc->vc_state = ESnormal;
2536                 return;
2537         case EShash:
2538                 vc->vc_state = ESnormal;
2539                 if (c == '8') {
2540                         /* DEC screen alignment test. kludge :-) */
2541                         vc->vc_video_erase_char =
2542                                 (vc->vc_video_erase_char & 0xff00) | 'E';
2543                         csi_J(vc, 2);
2544                         vc->vc_video_erase_char =
2545                                 (vc->vc_video_erase_char & 0xff00) | ' ';
2546                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2547                 }
2548                 return;
2549         case ESsetG0:
2550                 vc_setGx(vc, 0, c);
2551                 vc->vc_state = ESnormal;
2552                 return;
2553         case ESsetG1:
2554                 vc_setGx(vc, 1, c);
2555                 vc->vc_state = ESnormal;
2556                 return;
2557         case ESapc:
2558                 return;
2559         case ESosc:
2560                 return;
2561         case ESpm:
2562                 return;
2563         case ESdcs:
2564                 return;
2565         default:
2566                 vc->vc_state = ESnormal;
2567         }
2568 }
2569
2570 /* is_double_width() is based on the wcwidth() implementation by
2571  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2572  * Latest version: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2573  */
2574 struct interval {
2575         uint32_t first;
2576         uint32_t last;
2577 };
2578
2579 static int ucs_cmp(const void *key, const void *elt)
2580 {
2581         uint32_t ucs = *(uint32_t *)key;
2582         struct interval e = *(struct interval *) elt;
2583
2584         if (ucs > e.last)
2585                 return 1;
2586         else if (ucs < e.first)
2587                 return -1;
2588         return 0;
2589 }
2590
2591 static int is_double_width(uint32_t ucs)
2592 {
2593         static const struct interval double_width[] = {
2594                 { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2595                 { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2596                 { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2597                 { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2598         };
2599         if (ucs < double_width[0].first ||
2600             ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2601                 return 0;
2602
2603         return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2604                         sizeof(struct interval), ucs_cmp) != NULL;
2605 }
2606
2607 struct vc_draw_region {
2608         unsigned long from, to;
2609         int x;
2610 };
2611
2612 static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
2613 {
2614         if (draw->x < 0)
2615                 return;
2616
2617         vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
2618                         (u16 *)draw->to - (u16 *)draw->from, vc->state.y,
2619                         draw->x);
2620         draw->x = -1;
2621 }
2622
2623 static inline int vc_translate_ascii(const struct vc_data *vc, int c)
2624 {
2625         if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
2626                 if (vc->vc_toggle_meta)
2627                         c |= 0x80;
2628
2629                 return vc->vc_translate[c];
2630         }
2631
2632         return c;
2633 }
2634
2635
2636 /**
2637  * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
2638  * @c: the received character, or U+FFFD for invalid sequences.
2639  */
2640 static inline int vc_sanitize_unicode(const int c)
2641 {
2642         if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2643                 return 0xfffd;
2644
2645         return c;
2646 }
2647
2648 /**
2649  * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
2650  * @vc: virtual console
2651  * @c: character to translate
2652  * @rescan: we return true if we need more (continuation) data
2653  *
2654  * @vc_utf_char is the being-constructed unicode character.
2655  * @vc_utf_count is the number of continuation bytes still expected to arrive.
2656  * @vc_npar is the number of continuation bytes arrived so far.
2657  */
2658 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
2659 {
2660         static const u32 utf8_length_changes[] = {
2661                 0x0000007f, 0x000007ff, 0x0000ffff,
2662                 0x001fffff, 0x03ffffff, 0x7fffffff
2663         };
2664
2665         /* Continuation byte received */
2666         if ((c & 0xc0) == 0x80) {
2667                 /* Unexpected continuation byte? */
2668                 if (!vc->vc_utf_count)
2669                         return 0xfffd;
2670
2671                 vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2672                 vc->vc_npar++;
2673                 if (--vc->vc_utf_count)
2674                         goto need_more_bytes;
2675
2676                 /* Got a whole character */
2677                 c = vc->vc_utf_char;
2678                 /* Reject overlong sequences */
2679                 if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2680                                 c > utf8_length_changes[vc->vc_npar])
2681                         return 0xfffd;
2682
2683                 return vc_sanitize_unicode(c);
2684         }
2685
2686         /* Single ASCII byte or first byte of a sequence received */
2687         if (vc->vc_utf_count) {
2688                 /* Continuation byte expected */
2689                 *rescan = true;
2690                 vc->vc_utf_count = 0;
2691                 return 0xfffd;
2692         }
2693
2694         /* Nothing to do if an ASCII byte was received */
2695         if (c <= 0x7f)
2696                 return c;
2697
2698         /* First byte of a multibyte sequence received */
2699         vc->vc_npar = 0;
2700         if ((c & 0xe0) == 0xc0) {
2701                 vc->vc_utf_count = 1;
2702                 vc->vc_utf_char = (c & 0x1f);
2703         } else if ((c & 0xf0) == 0xe0) {
2704                 vc->vc_utf_count = 2;
2705                 vc->vc_utf_char = (c & 0x0f);
2706         } else if ((c & 0xf8) == 0xf0) {
2707                 vc->vc_utf_count = 3;
2708                 vc->vc_utf_char = (c & 0x07);
2709         } else if ((c & 0xfc) == 0xf8) {
2710                 vc->vc_utf_count = 4;
2711                 vc->vc_utf_char = (c & 0x03);
2712         } else if ((c & 0xfe) == 0xfc) {
2713                 vc->vc_utf_count = 5;
2714                 vc->vc_utf_char = (c & 0x01);
2715         } else {
2716                 /* 254 and 255 are invalid */
2717                 return 0xfffd;
2718         }
2719
2720 need_more_bytes:
2721         return -1;
2722 }
2723
2724 static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
2725 {
2726         /* Do no translation at all in control states */
2727         if (vc->vc_state != ESnormal)
2728                 return *c;
2729
2730         if (vc->vc_utf && !vc->vc_disp_ctrl)
2731                 return *c = vc_translate_unicode(vc, *c, rescan);
2732
2733         /* no utf or alternate charset mode */
2734         return vc_translate_ascii(vc, *c);
2735 }
2736
2737 static inline unsigned char vc_invert_attr(const struct vc_data *vc)
2738 {
2739         if (!vc->vc_can_do_color)
2740                 return vc->vc_attr ^ 0x08;
2741
2742         if (vc->vc_hi_font_mask == 0x100)
2743                 return   (vc->vc_attr & 0x11) |
2744                         ((vc->vc_attr & 0xe0) >> 4) |
2745                         ((vc->vc_attr & 0x0e) << 4);
2746
2747         return   (vc->vc_attr & 0x88) |
2748                 ((vc->vc_attr & 0x70) >> 4) |
2749                 ((vc->vc_attr & 0x07) << 4);
2750 }
2751
2752 static bool vc_is_control(struct vc_data *vc, int tc, int c)
2753 {
2754         /*
2755          * A bitmap for codes <32. A bit of 1 indicates that the code
2756          * corresponding to that bit number invokes some special action (such
2757          * as cursor movement) and should not be displayed as a glyph unless
2758          * the disp_ctrl mode is explicitly enabled.
2759          */
2760         static const u32 CTRL_ACTION = 0x0d00ff81;
2761         /* Cannot be overridden by disp_ctrl */
2762         static const u32 CTRL_ALWAYS = 0x0800f501;
2763
2764         if (vc->vc_state != ESnormal)
2765                 return true;
2766
2767         if (!tc)
2768                 return true;
2769
2770         /*
2771          * If the original code was a control character we only allow a glyph
2772          * to be displayed if the code is not normally used (such as for cursor
2773          * movement) or if the disp_ctrl mode has been explicitly enabled.
2774          * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
2775          * displayed as control characters, as the console would be pretty
2776          * useless without them; to display an arbitrary font position use the
2777          * direct-to-font zone in UTF-8 mode.
2778          */
2779         if (c < 32) {
2780                 if (vc->vc_disp_ctrl)
2781                         return CTRL_ALWAYS & BIT(c);
2782                 else
2783                         return vc->vc_utf || (CTRL_ACTION & BIT(c));
2784         }
2785
2786         if (c == 127 && !vc->vc_disp_ctrl)
2787                 return true;
2788
2789         if (c == 128 + 27)
2790                 return true;
2791
2792         return false;
2793 }
2794
2795 static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
2796                 struct vc_draw_region *draw)
2797 {
2798         int next_c;
2799         unsigned char vc_attr = vc->vc_attr;
2800         u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
2801         u8 width = 1;
2802         bool inverse = false;
2803
2804         if (vc->vc_utf && !vc->vc_disp_ctrl) {
2805                 if (is_double_width(c))
2806                         width = 2;
2807         }
2808
2809         /* Now try to find out how to display it */
2810         tc = conv_uni_to_pc(vc, tc);
2811         if (tc & ~charmask) {
2812                 if (tc == -1 || tc == -2)
2813                         return -1; /* nothing to display */
2814
2815                 /* Glyph not found */
2816                 if ((!vc->vc_utf || vc->vc_disp_ctrl || c < 128) &&
2817                                 !(c & ~charmask)) {
2818                         /*
2819                          * In legacy mode use the glyph we get by a 1:1
2820                          * mapping.
2821                          * This would make absolutely no sense with Unicode in
2822                          * mind, but do this for ASCII characters since a font
2823                          * may lack Unicode mapping info and we don't want to
2824                          * end up with having question marks only.
2825                          */
2826                         tc = c;
2827                 } else {
2828                         /*
2829                          * Display U+FFFD. If it's not found, display an inverse
2830                          * question mark.
2831                          */
2832                         tc = conv_uni_to_pc(vc, 0xfffd);
2833                         if (tc < 0) {
2834                                 inverse = true;
2835                                 tc = conv_uni_to_pc(vc, '?');
2836                                 if (tc < 0)
2837                                         tc = '?';
2838
2839                                 vc_attr = vc_invert_attr(vc);
2840                                 con_flush(vc, draw);
2841                         }
2842                 }
2843         }
2844
2845         next_c = c;
2846         while (1) {
2847                 if (vc->vc_need_wrap || vc->vc_decim)
2848                         con_flush(vc, draw);
2849                 if (vc->vc_need_wrap) {
2850                         cr(vc);
2851                         lf(vc);
2852                 }
2853                 if (vc->vc_decim)
2854                         insert_char(vc, 1);
2855                 vc_uniscr_putc(vc, next_c);
2856
2857                 if (himask)
2858                         tc = ((tc & 0x100) ? himask : 0) |
2859                               (tc &  0xff);
2860                 tc |= (vc_attr << 8) & ~himask;
2861
2862                 scr_writew(tc, (u16 *)vc->vc_pos);
2863
2864                 if (con_should_update(vc) && draw->x < 0) {
2865                         draw->x = vc->state.x;
2866                         draw->from = vc->vc_pos;
2867                 }
2868                 if (vc->state.x == vc->vc_cols - 1) {
2869                         vc->vc_need_wrap = vc->vc_decawm;
2870                         draw->to = vc->vc_pos + 2;
2871                 } else {
2872                         vc->state.x++;
2873                         draw->to = (vc->vc_pos += 2);
2874                 }
2875
2876                 if (!--width)
2877                         break;
2878
2879                 /* A space is printed in the second column */
2880                 tc = conv_uni_to_pc(vc, ' ');
2881                 if (tc < 0)
2882                         tc = ' ';
2883                 next_c = ' ';
2884         }
2885         notify_write(vc, c);
2886
2887         if (inverse)
2888                 con_flush(vc, draw);
2889
2890         return 0;
2891 }
2892
2893 /* acquires console_lock */
2894 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2895 {
2896         struct vc_draw_region draw = {
2897                 .x = -1,
2898         };
2899         int c, tc, n = 0;
2900         unsigned int currcons;
2901         struct vc_data *vc;
2902         struct vt_notifier_param param;
2903         bool rescan;
2904
2905         if (in_interrupt())
2906                 return count;
2907
2908         console_lock();
2909         vc = tty->driver_data;
2910         if (vc == NULL) {
2911                 pr_err("vt: argh, driver_data is NULL !\n");
2912                 console_unlock();
2913                 return 0;
2914         }
2915
2916         currcons = vc->vc_num;
2917         if (!vc_cons_allocated(currcons)) {
2918                 /* could this happen? */
2919                 pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2920                 console_unlock();
2921                 return 0;
2922         }
2923
2924
2925         /* undraw cursor first */
2926         if (con_is_fg(vc))
2927                 hide_cursor(vc);
2928
2929         param.vc = vc;
2930
2931         while (!tty->flow.stopped && count) {
2932                 int orig = *buf;
2933                 buf++;
2934                 n++;
2935                 count--;
2936 rescan_last_byte:
2937                 c = orig;
2938                 rescan = false;
2939
2940                 tc = vc_translate(vc, &c, &rescan);
2941                 if (tc == -1)
2942                         continue;
2943
2944                 param.c = tc;
2945                 if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2946                                         &param) == NOTIFY_STOP)
2947                         continue;
2948
2949                 if (vc_is_control(vc, tc, c)) {
2950                         con_flush(vc, &draw);
2951                         do_con_trol(tty, vc, orig);
2952                         continue;
2953                 }
2954
2955                 if (vc_con_write_normal(vc, tc, c, &draw) < 0)
2956                         continue;
2957
2958                 if (rescan)
2959                         goto rescan_last_byte;
2960         }
2961         con_flush(vc, &draw);
2962         vc_uniscr_debug_check(vc);
2963         console_conditional_schedule();
2964         notify_update(vc);
2965         console_unlock();
2966         return n;
2967 }
2968
2969 /*
2970  * This is the console switching callback.
2971  *
2972  * Doing console switching in a process context allows
2973  * us to do the switches asynchronously (needed when we want
2974  * to switch due to a keyboard interrupt).  Synchronization
2975  * with other console code and prevention of re-entrancy is
2976  * ensured with console_lock.
2977  */
2978 static void console_callback(struct work_struct *ignored)
2979 {
2980         console_lock();
2981
2982         if (want_console >= 0) {
2983                 if (want_console != fg_console &&
2984                     vc_cons_allocated(want_console)) {
2985                         hide_cursor(vc_cons[fg_console].d);
2986                         change_console(vc_cons[want_console].d);
2987                         /* we only changed when the console had already
2988                            been allocated - a new console is not created
2989                            in an interrupt routine */
2990                 }
2991                 want_console = -1;
2992         }
2993         if (do_poke_blanked_console) { /* do not unblank for a LED change */
2994                 do_poke_blanked_console = 0;
2995                 poke_blanked_console();
2996         }
2997         if (scrollback_delta) {
2998                 struct vc_data *vc = vc_cons[fg_console].d;
2999                 clear_selection();
3000                 if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
3001                         vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
3002                 scrollback_delta = 0;
3003         }
3004         if (blank_timer_expired) {
3005                 do_blank_screen(0);
3006                 blank_timer_expired = 0;
3007         }
3008         notify_update(vc_cons[fg_console].d);
3009
3010         console_unlock();
3011 }
3012
3013 int set_console(int nr)
3014 {
3015         struct vc_data *vc = vc_cons[fg_console].d;
3016
3017         if (!vc_cons_allocated(nr) || vt_dont_switch ||
3018                 (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
3019
3020                 /*
3021                  * Console switch will fail in console_callback() or
3022                  * change_console() so there is no point scheduling
3023                  * the callback
3024                  *
3025                  * Existing set_console() users don't check the return
3026                  * value so this shouldn't break anything
3027                  */
3028                 return -EINVAL;
3029         }
3030
3031         want_console = nr;
3032         schedule_console_callback();
3033
3034         return 0;
3035 }
3036
3037 struct tty_driver *console_driver;
3038
3039 #ifdef CONFIG_VT_CONSOLE
3040
3041 /**
3042  * vt_kmsg_redirect() - Sets/gets the kernel message console
3043  * @new:        The new virtual terminal number or -1 if the console should stay
3044  *              unchanged
3045  *
3046  * By default, the kernel messages are always printed on the current virtual
3047  * console. However, the user may modify that default with the
3048  * TIOCL_SETKMSGREDIRECT ioctl call.
3049  *
3050  * This function sets the kernel message console to be @new. It returns the old
3051  * virtual console number. The virtual terminal number 0 (both as parameter and
3052  * return value) means no redirection (i.e. always printed on the currently
3053  * active console).
3054  *
3055  * The parameter -1 means that only the current console is returned, but the
3056  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
3057  * case to make the code more understandable.
3058  *
3059  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
3060  * the parameter and always returns 0.
3061  */
3062 int vt_kmsg_redirect(int new)
3063 {
3064         static int kmsg_con;
3065
3066         if (new != -1)
3067                 return xchg(&kmsg_con, new);
3068         else
3069                 return kmsg_con;
3070 }
3071
3072 /*
3073  *      Console on virtual terminal
3074  *
3075  * The console must be locked when we get here.
3076  */
3077
3078 static void vt_console_print(struct console *co, const char *b, unsigned count)
3079 {
3080         struct vc_data *vc = vc_cons[fg_console].d;
3081         unsigned char c;
3082         static DEFINE_SPINLOCK(printing_lock);
3083         const ushort *start;
3084         ushort start_x, cnt;
3085         int kmsg_console;
3086
3087         /* console busy or not yet initialized */
3088         if (!printable)
3089                 return;
3090         if (!spin_trylock(&printing_lock))
3091                 return;
3092
3093         kmsg_console = vt_get_kmsg_redirect();
3094         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
3095                 vc = vc_cons[kmsg_console - 1].d;
3096
3097         if (!vc_cons_allocated(fg_console)) {
3098                 /* impossible */
3099                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
3100                 goto quit;
3101         }
3102
3103         if (vc->vc_mode != KD_TEXT)
3104                 goto quit;
3105
3106         /* undraw cursor first */
3107         if (con_is_fg(vc))
3108                 hide_cursor(vc);
3109
3110         start = (ushort *)vc->vc_pos;
3111         start_x = vc->state.x;
3112         cnt = 0;
3113         while (count--) {
3114                 c = *b++;
3115                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
3116                         if (cnt && con_is_visible(vc))
3117                                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3118                         cnt = 0;
3119                         if (c == 8) {           /* backspace */
3120                                 bs(vc);
3121                                 start = (ushort *)vc->vc_pos;
3122                                 start_x = vc->state.x;
3123                                 continue;
3124                         }
3125                         if (c != 13)
3126                                 lf(vc);
3127                         cr(vc);
3128                         start = (ushort *)vc->vc_pos;
3129                         start_x = vc->state.x;
3130                         if (c == 10 || c == 13)
3131                                 continue;
3132                 }
3133                 vc_uniscr_putc(vc, c);
3134                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3135                 notify_write(vc, c);
3136                 cnt++;
3137                 if (vc->state.x == vc->vc_cols - 1) {
3138                         vc->vc_need_wrap = 1;
3139                 } else {
3140                         vc->vc_pos += 2;
3141                         vc->state.x++;
3142                 }
3143         }
3144         if (cnt && con_is_visible(vc))
3145                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3146         set_cursor(vc);
3147         notify_update(vc);
3148
3149 quit:
3150         spin_unlock(&printing_lock);
3151 }
3152
3153 static struct tty_driver *vt_console_device(struct console *c, int *index)
3154 {
3155         *index = c->index ? c->index-1 : fg_console;
3156         return console_driver;
3157 }
3158
3159 static struct console vt_console_driver = {
3160         .name           = "tty",
3161         .write          = vt_console_print,
3162         .device         = vt_console_device,
3163         .unblank        = unblank_screen,
3164         .flags          = CON_PRINTBUFFER,
3165         .index          = -1,
3166 };
3167 #endif
3168
3169 /*
3170  *      Handling of Linux-specific VC ioctls
3171  */
3172
3173 /*
3174  * Generally a bit racy with respect to console_lock();.
3175  *
3176  * There are some functions which don't need it.
3177  *
3178  * There are some functions which can sleep for arbitrary periods
3179  * (paste_selection) but we don't need the lock there anyway.
3180  *
3181  * set_selection_user has locking, and definitely needs it
3182  */
3183
3184 int tioclinux(struct tty_struct *tty, unsigned long arg)
3185 {
3186         char type, data;
3187         char __user *p = (char __user *)arg;
3188         int lines;
3189         int ret;
3190
3191         if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3192                 return -EPERM;
3193         if (get_user(type, p))
3194                 return -EFAULT;
3195         ret = 0;
3196
3197         switch (type)
3198         {
3199                 case TIOCL_SETSEL:
3200                         ret = set_selection_user((struct tiocl_selection
3201                                                  __user *)(p+1), tty);
3202                         break;
3203                 case TIOCL_PASTESEL:
3204                         ret = paste_selection(tty);
3205                         break;
3206                 case TIOCL_UNBLANKSCREEN:
3207                         console_lock();
3208                         unblank_screen();
3209                         console_unlock();
3210                         break;
3211                 case TIOCL_SELLOADLUT:
3212                         console_lock();
3213                         ret = sel_loadlut(p);
3214                         console_unlock();
3215                         break;
3216                 case TIOCL_GETSHIFTSTATE:
3217
3218         /*
3219          * Make it possible to react to Shift+Mousebutton.
3220          * Note that 'shift_state' is an undocumented
3221          * kernel-internal variable; programs not closely
3222          * related to the kernel should not use this.
3223          */
3224                         data = vt_get_shift_state();
3225                         ret = put_user(data, p);
3226                         break;
3227                 case TIOCL_GETMOUSEREPORTING:
3228                         console_lock(); /* May be overkill */
3229                         data = mouse_reporting();
3230                         console_unlock();
3231                         ret = put_user(data, p);
3232                         break;
3233                 case TIOCL_SETVESABLANK:
3234                         console_lock();
3235                         ret = set_vesa_blanking(p);
3236                         console_unlock();
3237                         break;
3238                 case TIOCL_GETKMSGREDIRECT:
3239                         data = vt_get_kmsg_redirect();
3240                         ret = put_user(data, p);
3241                         break;
3242                 case TIOCL_SETKMSGREDIRECT:
3243                         if (!capable(CAP_SYS_ADMIN)) {
3244                                 ret = -EPERM;
3245                         } else {
3246                                 if (get_user(data, p+1))
3247                                         ret = -EFAULT;
3248                                 else
3249                                         vt_kmsg_redirect(data);
3250                         }
3251                         break;
3252                 case TIOCL_GETFGCONSOLE:
3253                         /* No locking needed as this is a transiently
3254                            correct return anyway if the caller hasn't
3255                            disabled switching */
3256                         ret = fg_console;
3257                         break;
3258                 case TIOCL_SCROLLCONSOLE:
3259                         if (get_user(lines, (s32 __user *)(p+4))) {
3260                                 ret = -EFAULT;
3261                         } else {
3262                                 /* Need the console lock here. Note that lots
3263                                    of other calls need fixing before the lock
3264                                    is actually useful ! */
3265                                 console_lock();
3266                                 scrollfront(vc_cons[fg_console].d, lines);
3267                                 console_unlock();
3268                                 ret = 0;
3269                         }
3270                         break;
3271                 case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
3272                         console_lock();
3273                         ignore_poke = 1;
3274                         do_blank_screen(0);
3275                         console_unlock();
3276                         break;
3277                 case TIOCL_BLANKEDSCREEN:
3278                         ret = console_blanked;
3279                         break;
3280                 default:
3281                         ret = -EINVAL;
3282                         break;
3283         }
3284         return ret;
3285 }
3286
3287 /*
3288  * /dev/ttyN handling
3289  */
3290
3291 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3292 {
3293         int     retval;
3294
3295         retval = do_con_write(tty, buf, count);
3296         con_flush_chars(tty);
3297
3298         return retval;
3299 }
3300
3301 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3302 {
3303         return do_con_write(tty, &ch, 1);
3304 }
3305
3306 static unsigned int con_write_room(struct tty_struct *tty)
3307 {
3308         if (tty->flow.stopped)
3309                 return 0;
3310         return 32768;           /* No limit, really; we're not buffering */
3311 }
3312
3313 /*
3314  * con_throttle and con_unthrottle are only used for
3315  * paste_selection(), which has to stuff in a large number of
3316  * characters...
3317  */
3318 static void con_throttle(struct tty_struct *tty)
3319 {
3320 }
3321
3322 static void con_unthrottle(struct tty_struct *tty)
3323 {
3324         struct vc_data *vc = tty->driver_data;
3325
3326         wake_up_interruptible(&vc->paste_wait);
3327 }
3328
3329 /*
3330  * Turn the Scroll-Lock LED on when the tty is stopped
3331  */
3332 static void con_stop(struct tty_struct *tty)
3333 {
3334         int console_num;
3335         if (!tty)
3336                 return;
3337         console_num = tty->index;
3338         if (!vc_cons_allocated(console_num))
3339                 return;
3340         vt_kbd_con_stop(console_num);
3341 }
3342
3343 /*
3344  * Turn the Scroll-Lock LED off when the console is started
3345  */
3346 static void con_start(struct tty_struct *tty)
3347 {
3348         int console_num;
3349         if (!tty)
3350                 return;
3351         console_num = tty->index;
3352         if (!vc_cons_allocated(console_num))
3353                 return;
3354         vt_kbd_con_start(console_num);
3355 }
3356
3357 static void con_flush_chars(struct tty_struct *tty)
3358 {
3359         struct vc_data *vc;
3360
3361         if (in_interrupt())     /* from flush_to_ldisc */
3362                 return;
3363
3364         /* if we race with con_close(), vt may be null */
3365         console_lock();
3366         vc = tty->driver_data;
3367         if (vc)
3368                 set_cursor(vc);
3369         console_unlock();
3370 }
3371
3372 /*
3373  * Allocate the console screen memory.
3374  */
3375 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3376 {
3377         unsigned int currcons = tty->index;
3378         struct vc_data *vc;
3379         int ret;
3380
3381         console_lock();
3382         ret = vc_allocate(currcons);
3383         if (ret)
3384                 goto unlock;
3385
3386         vc = vc_cons[currcons].d;
3387
3388         /* Still being freed */
3389         if (vc->port.tty) {
3390                 ret = -ERESTARTSYS;
3391                 goto unlock;
3392         }
3393
3394         ret = tty_port_install(&vc->port, driver, tty);
3395         if (ret)
3396                 goto unlock;
3397
3398         tty->driver_data = vc;
3399         vc->port.tty = tty;
3400         tty_port_get(&vc->port);
3401
3402         if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3403                 tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3404                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3405         }
3406         if (vc->vc_utf)
3407                 tty->termios.c_iflag |= IUTF8;
3408         else
3409                 tty->termios.c_iflag &= ~IUTF8;
3410 unlock:
3411         console_unlock();
3412         return ret;
3413 }
3414
3415 static int con_open(struct tty_struct *tty, struct file *filp)
3416 {
3417         /* everything done in install */
3418         return 0;
3419 }
3420
3421
3422 static void con_close(struct tty_struct *tty, struct file *filp)
3423 {
3424         /* Nothing to do - we defer to shutdown */
3425 }
3426
3427 static void con_shutdown(struct tty_struct *tty)
3428 {
3429         struct vc_data *vc = tty->driver_data;
3430         BUG_ON(vc == NULL);
3431         console_lock();
3432         vc->port.tty = NULL;
3433         console_unlock();
3434 }
3435
3436 static void con_cleanup(struct tty_struct *tty)
3437 {
3438         struct vc_data *vc = tty->driver_data;
3439
3440         tty_port_put(&vc->port);
3441 }
3442
3443 static int default_color           = 7; /* white */
3444 static int default_italic_color    = 2; // green (ASCII)
3445 static int default_underline_color = 3; // cyan (ASCII)
3446 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3447 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3448 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3449
3450 static void vc_init(struct vc_data *vc, unsigned int rows,
3451                     unsigned int cols, int do_clear)
3452 {
3453         int j, k ;
3454
3455         vc->vc_cols = cols;
3456         vc->vc_rows = rows;
3457         vc->vc_size_row = cols << 1;
3458         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3459
3460         set_origin(vc);
3461         vc->vc_pos = vc->vc_origin;
3462         reset_vc(vc);
3463         for (j=k=0; j<16; j++) {
3464                 vc->vc_palette[k++] = default_red[j] ;
3465                 vc->vc_palette[k++] = default_grn[j] ;
3466                 vc->vc_palette[k++] = default_blu[j] ;
3467         }
3468         vc->vc_def_color       = default_color;
3469         vc->vc_ulcolor         = default_underline_color;
3470         vc->vc_itcolor         = default_italic_color;
3471         vc->vc_halfcolor       = 0x08;   /* grey */
3472         init_waitqueue_head(&vc->paste_wait);
3473         reset_terminal(vc, do_clear);
3474 }
3475
3476 /*
3477  * This routine initializes console interrupts, and does nothing
3478  * else. If you want the screen to clear, call tty_write with
3479  * the appropriate escape-sequence.
3480  */
3481
3482 static int __init con_init(void)
3483 {
3484         const char *display_desc = NULL;
3485         struct vc_data *vc;
3486         unsigned int currcons = 0, i;
3487
3488         console_lock();
3489
3490         if (!conswitchp)
3491                 conswitchp = &dummy_con;
3492         display_desc = conswitchp->con_startup();
3493         if (!display_desc) {
3494                 fg_console = 0;
3495                 console_unlock();
3496                 return 0;
3497         }
3498
3499         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3500                 struct con_driver *con_driver = &registered_con_driver[i];
3501
3502                 if (con_driver->con == NULL) {
3503                         con_driver->con = conswitchp;
3504                         con_driver->desc = display_desc;
3505                         con_driver->flag = CON_DRIVER_FLAG_INIT;
3506                         con_driver->first = 0;
3507                         con_driver->last = MAX_NR_CONSOLES - 1;
3508                         break;
3509                 }
3510         }
3511
3512         for (i = 0; i < MAX_NR_CONSOLES; i++)
3513                 con_driver_map[i] = conswitchp;
3514
3515         if (blankinterval) {
3516                 blank_state = blank_normal_wait;
3517                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3518         }
3519
3520         for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3521                 vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3522                 INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3523                 tty_port_init(&vc->port);
3524                 visual_init(vc, currcons, 1);
3525                 /* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3526                 vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3527                 vc_init(vc, vc->vc_rows, vc->vc_cols,
3528                         currcons || !vc->vc_sw->con_save_screen);
3529         }
3530         currcons = fg_console = 0;
3531         master_display_fg = vc = vc_cons[currcons].d;
3532         set_origin(vc);
3533         save_screen(vc);
3534         gotoxy(vc, vc->state.x, vc->state.y);
3535         csi_J(vc, 0);
3536         update_screen(vc);
3537         pr_info("Console: %s %s %dx%d\n",
3538                 vc->vc_can_do_color ? "colour" : "mono",
3539                 display_desc, vc->vc_cols, vc->vc_rows);
3540         printable = 1;
3541
3542         console_unlock();
3543
3544 #ifdef CONFIG_VT_CONSOLE
3545         register_console(&vt_console_driver);
3546 #endif
3547         return 0;
3548 }
3549 console_initcall(con_init);
3550
3551 static const struct tty_operations con_ops = {
3552         .install = con_install,
3553         .open = con_open,
3554         .close = con_close,
3555         .write = con_write,
3556         .write_room = con_write_room,
3557         .put_char = con_put_char,
3558         .flush_chars = con_flush_chars,
3559         .ioctl = vt_ioctl,
3560 #ifdef CONFIG_COMPAT
3561         .compat_ioctl = vt_compat_ioctl,
3562 #endif
3563         .stop = con_stop,
3564         .start = con_start,
3565         .throttle = con_throttle,
3566         .unthrottle = con_unthrottle,
3567         .resize = vt_resize,
3568         .shutdown = con_shutdown,
3569         .cleanup = con_cleanup,
3570 };
3571
3572 static struct cdev vc0_cdev;
3573
3574 static ssize_t show_tty_active(struct device *dev,
3575                                 struct device_attribute *attr, char *buf)
3576 {
3577         return sprintf(buf, "tty%d\n", fg_console + 1);
3578 }
3579 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3580
3581 static struct attribute *vt_dev_attrs[] = {
3582         &dev_attr_active.attr,
3583         NULL
3584 };
3585
3586 ATTRIBUTE_GROUPS(vt_dev);
3587
3588 int __init vty_init(const struct file_operations *console_fops)
3589 {
3590         cdev_init(&vc0_cdev, console_fops);
3591         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3592             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3593                 panic("Couldn't register /dev/tty0 driver\n");
3594         tty0dev = device_create_with_groups(tty_class, NULL,
3595                                             MKDEV(TTY_MAJOR, 0), NULL,
3596                                             vt_dev_groups, "tty0");
3597         if (IS_ERR(tty0dev))
3598                 tty0dev = NULL;
3599
3600         vcs_init();
3601
3602         console_driver = tty_alloc_driver(MAX_NR_CONSOLES, TTY_DRIVER_REAL_RAW |
3603                         TTY_DRIVER_RESET_TERMIOS);
3604         if (IS_ERR(console_driver))
3605                 panic("Couldn't allocate console driver\n");
3606
3607         console_driver->name = "tty";
3608         console_driver->name_base = 1;
3609         console_driver->major = TTY_MAJOR;
3610         console_driver->minor_start = 1;
3611         console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3612         console_driver->init_termios = tty_std_termios;
3613         if (default_utf8)
3614                 console_driver->init_termios.c_iflag |= IUTF8;
3615         tty_set_operations(console_driver, &con_ops);
3616         if (tty_register_driver(console_driver))
3617                 panic("Couldn't register console driver\n");
3618         kbd_init();
3619         console_map_init();
3620 #ifdef CONFIG_MDA_CONSOLE
3621         mda_console_init();
3622 #endif
3623         return 0;
3624 }
3625
3626 #ifndef VT_SINGLE_DRIVER
3627
3628 static struct class *vtconsole_class;
3629
3630 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3631                            int deflt)
3632 {
3633         struct module *owner = csw->owner;
3634         const char *desc = NULL;
3635         struct con_driver *con_driver;
3636         int i, j = -1, k = -1, retval = -ENODEV;
3637
3638         if (!try_module_get(owner))
3639                 return -ENODEV;
3640
3641         WARN_CONSOLE_UNLOCKED();
3642
3643         /* check if driver is registered */
3644         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3645                 con_driver = &registered_con_driver[i];
3646
3647                 if (con_driver->con == csw) {
3648                         desc = con_driver->desc;
3649                         retval = 0;
3650                         break;
3651                 }
3652         }
3653
3654         if (retval)
3655                 goto err;
3656
3657         if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3658                 csw->con_startup();
3659                 con_driver->flag |= CON_DRIVER_FLAG_INIT;
3660         }
3661
3662         if (deflt) {
3663                 if (conswitchp)
3664                         module_put(conswitchp->owner);
3665
3666                 __module_get(owner);
3667                 conswitchp = csw;
3668         }
3669
3670         first = max(first, con_driver->first);
3671         last = min(last, con_driver->last);
3672
3673         for (i = first; i <= last; i++) {
3674                 int old_was_color;
3675                 struct vc_data *vc = vc_cons[i].d;
3676
3677                 if (con_driver_map[i])
3678                         module_put(con_driver_map[i]->owner);
3679                 __module_get(owner);
3680                 con_driver_map[i] = csw;
3681
3682                 if (!vc || !vc->vc_sw)
3683                         continue;
3684
3685                 j = i;
3686
3687                 if (con_is_visible(vc)) {
3688                         k = i;
3689                         save_screen(vc);
3690                 }
3691
3692                 old_was_color = vc->vc_can_do_color;
3693                 vc->vc_sw->con_deinit(vc);
3694                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3695                 visual_init(vc, i, 0);
3696                 set_origin(vc);
3697                 update_attr(vc);
3698
3699                 /* If the console changed between mono <-> color, then
3700                  * the attributes in the screenbuf will be wrong.  The
3701                  * following resets all attributes to something sane.
3702                  */
3703                 if (old_was_color != vc->vc_can_do_color)
3704                         clear_buffer_attributes(vc);
3705         }
3706
3707         pr_info("Console: switching ");
3708         if (!deflt)
3709                 pr_cont("consoles %d-%d ", first + 1, last + 1);
3710         if (j >= 0) {
3711                 struct vc_data *vc = vc_cons[j].d;
3712
3713                 pr_cont("to %s %s %dx%d\n",
3714                         vc->vc_can_do_color ? "colour" : "mono",
3715                         desc, vc->vc_cols, vc->vc_rows);
3716
3717                 if (k >= 0) {
3718                         vc = vc_cons[k].d;
3719                         update_screen(vc);
3720                 }
3721         } else {
3722                 pr_cont("to %s\n", desc);
3723         }
3724
3725         retval = 0;
3726 err:
3727         module_put(owner);
3728         return retval;
3729 };
3730
3731
3732 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3733 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3734 {
3735         struct module *owner = csw->owner;
3736         const struct consw *defcsw = NULL;
3737         struct con_driver *con_driver = NULL, *con_back = NULL;
3738         int i, retval = -ENODEV;
3739
3740         if (!try_module_get(owner))
3741                 return -ENODEV;
3742
3743         WARN_CONSOLE_UNLOCKED();
3744
3745         /* check if driver is registered and if it is unbindable */
3746         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3747                 con_driver = &registered_con_driver[i];
3748
3749                 if (con_driver->con == csw &&
3750                     con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3751                         retval = 0;
3752                         break;
3753                 }
3754         }
3755
3756         if (retval)
3757                 goto err;
3758
3759         retval = -ENODEV;
3760
3761         /* check if backup driver exists */
3762         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3763                 con_back = &registered_con_driver[i];
3764
3765                 if (con_back->con && con_back->con != csw) {
3766                         defcsw = con_back->con;
3767                         retval = 0;
3768                         break;
3769                 }
3770         }
3771
3772         if (retval)
3773                 goto err;
3774
3775         if (!con_is_bound(csw))
3776                 goto err;
3777
3778         first = max(first, con_driver->first);
3779         last = min(last, con_driver->last);
3780
3781         for (i = first; i <= last; i++) {
3782                 if (con_driver_map[i] == csw) {
3783                         module_put(csw->owner);
3784                         con_driver_map[i] = NULL;
3785                 }
3786         }
3787
3788         if (!con_is_bound(defcsw)) {
3789                 const struct consw *defconsw = conswitchp;
3790
3791                 defcsw->con_startup();
3792                 con_back->flag |= CON_DRIVER_FLAG_INIT;
3793                 /*
3794                  * vgacon may change the default driver to point
3795                  * to dummycon, we restore it here...
3796                  */
3797                 conswitchp = defconsw;
3798         }
3799
3800         if (!con_is_bound(csw))
3801                 con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3802
3803         /* ignore return value, binding should not fail */
3804         do_bind_con_driver(defcsw, first, last, deflt);
3805 err:
3806         module_put(owner);
3807         return retval;
3808
3809 }
3810 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3811
3812 static int vt_bind(struct con_driver *con)
3813 {
3814         const struct consw *defcsw = NULL, *csw = NULL;
3815         int i, more = 1, first = -1, last = -1, deflt = 0;
3816
3817         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3818                 goto err;
3819
3820         csw = con->con;
3821
3822         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3823                 struct con_driver *con = &registered_con_driver[i];
3824
3825                 if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3826                         defcsw = con->con;
3827                         break;
3828                 }
3829         }
3830
3831         if (!defcsw)
3832                 goto err;
3833
3834         while (more) {
3835                 more = 0;
3836
3837                 for (i = con->first; i <= con->last; i++) {
3838                         if (con_driver_map[i] == defcsw) {
3839                                 if (first == -1)
3840                                         first = i;
3841                                 last = i;
3842                                 more = 1;
3843                         } else if (first != -1)
3844                                 break;
3845                 }
3846
3847                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3848                         deflt = 1;
3849
3850                 if (first != -1)
3851                         do_bind_con_driver(csw, first, last, deflt);
3852
3853                 first = -1;
3854                 last = -1;
3855                 deflt = 0;
3856         }
3857
3858 err:
3859         return 0;
3860 }
3861
3862 static int vt_unbind(struct con_driver *con)
3863 {
3864         const struct consw *csw = NULL;
3865         int i, more = 1, first = -1, last = -1, deflt = 0;
3866         int ret;
3867
3868         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3869                 goto err;
3870
3871         csw = con->con;
3872
3873         while (more) {
3874                 more = 0;
3875
3876                 for (i = con->first; i <= con->last; i++) {
3877                         if (con_driver_map[i] == csw) {
3878                                 if (first == -1)
3879                                         first = i;
3880                                 last = i;
3881                                 more = 1;
3882                         } else if (first != -1)
3883                                 break;
3884                 }
3885
3886                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3887                         deflt = 1;
3888
3889                 if (first != -1) {
3890                         ret = do_unbind_con_driver(csw, first, last, deflt);
3891                         if (ret != 0)
3892                                 return ret;
3893                 }
3894
3895                 first = -1;
3896                 last = -1;
3897                 deflt = 0;
3898         }
3899
3900 err:
3901         return 0;
3902 }
3903 #else
3904 static inline int vt_bind(struct con_driver *con)
3905 {
3906         return 0;
3907 }
3908 static inline int vt_unbind(struct con_driver *con)
3909 {
3910         return 0;
3911 }
3912 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3913
3914 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3915                           const char *buf, size_t count)
3916 {
3917         struct con_driver *con = dev_get_drvdata(dev);
3918         int bind = simple_strtoul(buf, NULL, 0);
3919
3920         console_lock();
3921
3922         if (bind)
3923                 vt_bind(con);
3924         else
3925                 vt_unbind(con);
3926
3927         console_unlock();
3928
3929         return count;
3930 }
3931
3932 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3933                          char *buf)
3934 {
3935         struct con_driver *con = dev_get_drvdata(dev);
3936         int bind;
3937
3938         console_lock();
3939         bind = con_is_bound(con->con);
3940         console_unlock();
3941
3942         return sysfs_emit(buf, "%i\n", bind);
3943 }
3944
3945 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3946                          char *buf)
3947 {
3948         struct con_driver *con = dev_get_drvdata(dev);
3949
3950         return sysfs_emit(buf, "%s %s\n",
3951                         (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3952                          con->desc);
3953
3954 }
3955
3956 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3957 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3958
3959 static struct attribute *con_dev_attrs[] = {
3960         &dev_attr_bind.attr,
3961         &dev_attr_name.attr,
3962         NULL
3963 };
3964
3965 ATTRIBUTE_GROUPS(con_dev);
3966
3967 static int vtconsole_init_device(struct con_driver *con)
3968 {
3969         con->flag |= CON_DRIVER_FLAG_ATTR;
3970         return 0;
3971 }
3972
3973 static void vtconsole_deinit_device(struct con_driver *con)
3974 {
3975         con->flag &= ~CON_DRIVER_FLAG_ATTR;
3976 }
3977
3978 /**
3979  * con_is_bound - checks if driver is bound to the console
3980  * @csw: console driver
3981  *
3982  * RETURNS: zero if unbound, nonzero if bound
3983  *
3984  * Drivers can call this and if zero, they should release
3985  * all resources allocated on con_startup()
3986  */
3987 int con_is_bound(const struct consw *csw)
3988 {
3989         int i, bound = 0;
3990
3991         WARN_CONSOLE_UNLOCKED();
3992
3993         for (i = 0; i < MAX_NR_CONSOLES; i++) {
3994                 if (con_driver_map[i] == csw) {
3995                         bound = 1;
3996                         break;
3997                 }
3998         }
3999
4000         return bound;
4001 }
4002 EXPORT_SYMBOL(con_is_bound);
4003
4004 /**
4005  * con_is_visible - checks whether the current console is visible
4006  * @vc: virtual console
4007  *
4008  * RETURNS: zero if not visible, nonzero if visible
4009  */
4010 bool con_is_visible(const struct vc_data *vc)
4011 {
4012         WARN_CONSOLE_UNLOCKED();
4013
4014         return *vc->vc_display_fg == vc;
4015 }
4016 EXPORT_SYMBOL(con_is_visible);
4017
4018 /**
4019  * con_debug_enter - prepare the console for the kernel debugger
4020  * @vc: virtual console
4021  *
4022  * Called when the console is taken over by the kernel debugger, this
4023  * function needs to save the current console state, then put the console
4024  * into a state suitable for the kernel debugger.
4025  *
4026  * RETURNS:
4027  * Zero on success, nonzero if a failure occurred when trying to prepare
4028  * the console for the debugger.
4029  */
4030 int con_debug_enter(struct vc_data *vc)
4031 {
4032         int ret = 0;
4033
4034         saved_fg_console = fg_console;
4035         saved_last_console = last_console;
4036         saved_want_console = want_console;
4037         saved_vc_mode = vc->vc_mode;
4038         saved_console_blanked = console_blanked;
4039         vc->vc_mode = KD_TEXT;
4040         console_blanked = 0;
4041         if (vc->vc_sw->con_debug_enter)
4042                 ret = vc->vc_sw->con_debug_enter(vc);
4043 #ifdef CONFIG_KGDB_KDB
4044         /* Set the initial LINES variable if it is not already set */
4045         if (vc->vc_rows < 999) {
4046                 int linecount;
4047                 char lns[4];
4048                 const char *setargs[3] = {
4049                         "set",
4050                         "LINES",
4051                         lns,
4052                 };
4053                 if (kdbgetintenv(setargs[0], &linecount)) {
4054                         snprintf(lns, 4, "%i", vc->vc_rows);
4055                         kdb_set(2, setargs);
4056                 }
4057         }
4058         if (vc->vc_cols < 999) {
4059                 int colcount;
4060                 char cols[4];
4061                 const char *setargs[3] = {
4062                         "set",
4063                         "COLUMNS",
4064                         cols,
4065                 };
4066                 if (kdbgetintenv(setargs[0], &colcount)) {
4067                         snprintf(cols, 4, "%i", vc->vc_cols);
4068                         kdb_set(2, setargs);
4069                 }
4070         }
4071 #endif /* CONFIG_KGDB_KDB */
4072         return ret;
4073 }
4074 EXPORT_SYMBOL_GPL(con_debug_enter);
4075
4076 /**
4077  * con_debug_leave - restore console state
4078  *
4079  * Restore the console state to what it was before the kernel debugger
4080  * was invoked.
4081  *
4082  * RETURNS:
4083  * Zero on success, nonzero if a failure occurred when trying to restore
4084  * the console.
4085  */
4086 int con_debug_leave(void)
4087 {
4088         struct vc_data *vc;
4089         int ret = 0;
4090
4091         fg_console = saved_fg_console;
4092         last_console = saved_last_console;
4093         want_console = saved_want_console;
4094         console_blanked = saved_console_blanked;
4095         vc_cons[fg_console].d->vc_mode = saved_vc_mode;
4096
4097         vc = vc_cons[fg_console].d;
4098         if (vc->vc_sw->con_debug_leave)
4099                 ret = vc->vc_sw->con_debug_leave(vc);
4100         return ret;
4101 }
4102 EXPORT_SYMBOL_GPL(con_debug_leave);
4103
4104 static int do_register_con_driver(const struct consw *csw, int first, int last)
4105 {
4106         struct module *owner = csw->owner;
4107         struct con_driver *con_driver;
4108         const char *desc;
4109         int i, retval;
4110
4111         WARN_CONSOLE_UNLOCKED();
4112
4113         if (!try_module_get(owner))
4114                 return -ENODEV;
4115
4116         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4117                 con_driver = &registered_con_driver[i];
4118
4119                 /* already registered */
4120                 if (con_driver->con == csw) {
4121                         retval = -EBUSY;
4122                         goto err;
4123                 }
4124         }
4125
4126         desc = csw->con_startup();
4127         if (!desc) {
4128                 retval = -ENODEV;
4129                 goto err;
4130         }
4131
4132         retval = -EINVAL;
4133
4134         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4135                 con_driver = &registered_con_driver[i];
4136
4137                 if (con_driver->con == NULL &&
4138                     !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
4139                         con_driver->con = csw;
4140                         con_driver->desc = desc;
4141                         con_driver->node = i;
4142                         con_driver->flag = CON_DRIVER_FLAG_MODULE |
4143                                            CON_DRIVER_FLAG_INIT;
4144                         con_driver->first = first;
4145                         con_driver->last = last;
4146                         retval = 0;
4147                         break;
4148                 }
4149         }
4150
4151         if (retval)
4152                 goto err;
4153
4154         con_driver->dev =
4155                 device_create_with_groups(vtconsole_class, NULL,
4156                                           MKDEV(0, con_driver->node),
4157                                           con_driver, con_dev_groups,
4158                                           "vtcon%i", con_driver->node);
4159         if (IS_ERR(con_driver->dev)) {
4160                 pr_warn("Unable to create device for %s; errno = %ld\n",
4161                         con_driver->desc, PTR_ERR(con_driver->dev));
4162                 con_driver->dev = NULL;
4163         } else {
4164                 vtconsole_init_device(con_driver);
4165         }
4166
4167 err:
4168         module_put(owner);
4169         return retval;
4170 }
4171
4172
4173 /**
4174  * do_unregister_con_driver - unregister console driver from console layer
4175  * @csw: console driver
4176  *
4177  * DESCRIPTION: All drivers that registers to the console layer must
4178  * call this function upon exit, or if the console driver is in a state
4179  * where it won't be able to handle console services, such as the
4180  * framebuffer console without loaded framebuffer drivers.
4181  *
4182  * The driver must unbind first prior to unregistration.
4183  */
4184 int do_unregister_con_driver(const struct consw *csw)
4185 {
4186         int i;
4187
4188         /* cannot unregister a bound driver */
4189         if (con_is_bound(csw))
4190                 return -EBUSY;
4191
4192         if (csw == conswitchp)
4193                 return -EINVAL;
4194
4195         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4196                 struct con_driver *con_driver = &registered_con_driver[i];
4197
4198                 if (con_driver->con == csw) {
4199                         /*
4200                          * Defer the removal of the sysfs entries since that
4201                          * will acquire the kernfs s_active lock and we can't
4202                          * acquire this lock while holding the console lock:
4203                          * the unbind sysfs entry imposes already the opposite
4204                          * order. Reset con already here to prevent any later
4205                          * lookup to succeed and mark this slot as zombie, so
4206                          * it won't get reused until we complete the removal
4207                          * in the deferred work.
4208                          */
4209                         con_driver->con = NULL;
4210                         con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4211                         schedule_work(&con_driver_unregister_work);
4212
4213                         return 0;
4214                 }
4215         }
4216
4217         return -ENODEV;
4218 }
4219 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4220
4221 static void con_driver_unregister_callback(struct work_struct *ignored)
4222 {
4223         int i;
4224
4225         console_lock();
4226
4227         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4228                 struct con_driver *con_driver = &registered_con_driver[i];
4229
4230                 if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4231                         continue;
4232
4233                 console_unlock();
4234
4235                 vtconsole_deinit_device(con_driver);
4236                 device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4237
4238                 console_lock();
4239
4240                 if (WARN_ON_ONCE(con_driver->con))
4241                         con_driver->con = NULL;
4242                 con_driver->desc = NULL;
4243                 con_driver->dev = NULL;
4244                 con_driver->node = 0;
4245                 WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4246                 con_driver->flag = 0;
4247                 con_driver->first = 0;
4248                 con_driver->last = 0;
4249         }
4250
4251         console_unlock();
4252 }
4253
4254 /*
4255  *      If we support more console drivers, this function is used
4256  *      when a driver wants to take over some existing consoles
4257  *      and become default driver for newly opened ones.
4258  *
4259  *      do_take_over_console is basically a register followed by bind
4260  */
4261 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4262 {
4263         int err;
4264
4265         err = do_register_con_driver(csw, first, last);
4266         /*
4267          * If we get an busy error we still want to bind the console driver
4268          * and return success, as we may have unbound the console driver
4269          * but not unregistered it.
4270          */
4271         if (err == -EBUSY)
4272                 err = 0;
4273         if (!err)
4274                 do_bind_con_driver(csw, first, last, deflt);
4275
4276         return err;
4277 }
4278 EXPORT_SYMBOL_GPL(do_take_over_console);
4279
4280
4281 /*
4282  * give_up_console is a wrapper to unregister_con_driver. It will only
4283  * work if driver is fully unbound.
4284  */
4285 void give_up_console(const struct consw *csw)
4286 {
4287         console_lock();
4288         do_unregister_con_driver(csw);
4289         console_unlock();
4290 }
4291
4292 static int __init vtconsole_class_init(void)
4293 {
4294         int i;
4295
4296         vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4297         if (IS_ERR(vtconsole_class)) {
4298                 pr_warn("Unable to create vt console class; errno = %ld\n",
4299                         PTR_ERR(vtconsole_class));
4300                 vtconsole_class = NULL;
4301         }
4302
4303         /* Add system drivers to sysfs */
4304         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4305                 struct con_driver *con = &registered_con_driver[i];
4306
4307                 if (con->con && !con->dev) {
4308                         con->dev =
4309                                 device_create_with_groups(vtconsole_class, NULL,
4310                                                           MKDEV(0, con->node),
4311                                                           con, con_dev_groups,
4312                                                           "vtcon%i", con->node);
4313
4314                         if (IS_ERR(con->dev)) {
4315                                 pr_warn("Unable to create device for %s; errno = %ld\n",
4316                                         con->desc, PTR_ERR(con->dev));
4317                                 con->dev = NULL;
4318                         } else {
4319                                 vtconsole_init_device(con);
4320                         }
4321                 }
4322         }
4323
4324         return 0;
4325 }
4326 postcore_initcall(vtconsole_class_init);
4327
4328 #endif
4329
4330 /*
4331  *      Screen blanking
4332  */
4333
4334 static int set_vesa_blanking(char __user *p)
4335 {
4336         unsigned int mode;
4337
4338         if (get_user(mode, p + 1))
4339                 return -EFAULT;
4340
4341         vesa_blank_mode = (mode < 4) ? mode : 0;
4342         return 0;
4343 }
4344
4345 void do_blank_screen(int entering_gfx)
4346 {
4347         struct vc_data *vc = vc_cons[fg_console].d;
4348         int i;
4349
4350         might_sleep();
4351
4352         WARN_CONSOLE_UNLOCKED();
4353
4354         if (console_blanked) {
4355                 if (blank_state == blank_vesa_wait) {
4356                         blank_state = blank_off;
4357                         vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4358                 }
4359                 return;
4360         }
4361
4362         /* entering graphics mode? */
4363         if (entering_gfx) {
4364                 hide_cursor(vc);
4365                 save_screen(vc);
4366                 vc->vc_sw->con_blank(vc, -1, 1);
4367                 console_blanked = fg_console + 1;
4368                 blank_state = blank_off;
4369                 set_origin(vc);
4370                 return;
4371         }
4372
4373         blank_state = blank_off;
4374
4375         /* don't blank graphics */
4376         if (vc->vc_mode != KD_TEXT) {
4377                 console_blanked = fg_console + 1;
4378                 return;
4379         }
4380
4381         hide_cursor(vc);
4382         del_timer_sync(&console_timer);
4383         blank_timer_expired = 0;
4384
4385         save_screen(vc);
4386         /* In case we need to reset origin, blanking hook returns 1 */
4387         i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4388         console_blanked = fg_console + 1;
4389         if (i)
4390                 set_origin(vc);
4391
4392         if (console_blank_hook && console_blank_hook(1))
4393                 return;
4394
4395         if (vesa_off_interval && vesa_blank_mode) {
4396                 blank_state = blank_vesa_wait;
4397                 mod_timer(&console_timer, jiffies + vesa_off_interval);
4398         }
4399         vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4400 }
4401 EXPORT_SYMBOL(do_blank_screen);
4402
4403 /*
4404  * Called by timer as well as from vt_console_driver
4405  */
4406 void do_unblank_screen(int leaving_gfx)
4407 {
4408         struct vc_data *vc;
4409
4410         /* This should now always be called from a "sane" (read: can schedule)
4411          * context for the sake of the low level drivers, except in the special
4412          * case of oops_in_progress
4413          */
4414         if (!oops_in_progress)
4415                 might_sleep();
4416
4417         WARN_CONSOLE_UNLOCKED();
4418
4419         ignore_poke = 0;
4420         if (!console_blanked)
4421                 return;
4422         if (!vc_cons_allocated(fg_console)) {
4423                 /* impossible */
4424                 pr_warn("unblank_screen: tty %d not allocated ??\n",
4425                         fg_console + 1);
4426                 return;
4427         }
4428         vc = vc_cons[fg_console].d;
4429         if (vc->vc_mode != KD_TEXT)
4430                 return; /* but leave console_blanked != 0 */
4431
4432         if (blankinterval) {
4433                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4434                 blank_state = blank_normal_wait;
4435         }
4436
4437         console_blanked = 0;
4438         if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4439                 /* Low-level driver cannot restore -> do it ourselves */
4440                 update_screen(vc);
4441         if (console_blank_hook)
4442                 console_blank_hook(0);
4443         set_palette(vc);
4444         set_cursor(vc);
4445         vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4446 }
4447 EXPORT_SYMBOL(do_unblank_screen);
4448
4449 /*
4450  * This is called by the outside world to cause a forced unblank, mostly for
4451  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4452  * call it with 1 as an argument and so force a mode restore... that may kill
4453  * X or at least garbage the screen but would also make the Oops visible...
4454  */
4455 void unblank_screen(void)
4456 {
4457         do_unblank_screen(0);
4458 }
4459
4460 /*
4461  * We defer the timer blanking to work queue so it can take the console mutex
4462  * (console operations can still happen at irq time, but only from printk which
4463  * has the console mutex. Not perfect yet, but better than no locking
4464  */
4465 static void blank_screen_t(struct timer_list *unused)
4466 {
4467         blank_timer_expired = 1;
4468         schedule_work(&console_work);
4469 }
4470
4471 void poke_blanked_console(void)
4472 {
4473         WARN_CONSOLE_UNLOCKED();
4474
4475         /* Add this so we quickly catch whoever might call us in a non
4476          * safe context. Nowadays, unblank_screen() isn't to be called in
4477          * atomic contexts and is allowed to schedule (with the special case
4478          * of oops_in_progress, but that isn't of any concern for this
4479          * function. --BenH.
4480          */
4481         might_sleep();
4482
4483         /* This isn't perfectly race free, but a race here would be mostly harmless,
4484          * at worst, we'll do a spurious blank and it's unlikely
4485          */
4486         del_timer(&console_timer);
4487         blank_timer_expired = 0;
4488
4489         if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4490                 return;
4491         if (console_blanked)
4492                 unblank_screen();
4493         else if (blankinterval) {
4494                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4495                 blank_state = blank_normal_wait;
4496         }
4497 }
4498
4499 /*
4500  *      Palettes
4501  */
4502
4503 static void set_palette(struct vc_data *vc)
4504 {
4505         WARN_CONSOLE_UNLOCKED();
4506
4507         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4508                 vc->vc_sw->con_set_palette(vc, color_table);
4509 }
4510
4511 /*
4512  * Load palette into the DAC registers. arg points to a colour
4513  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4514  */
4515
4516 int con_set_cmap(unsigned char __user *arg)
4517 {
4518         int i, j, k;
4519         unsigned char colormap[3*16];
4520
4521         if (copy_from_user(colormap, arg, sizeof(colormap)))
4522                 return -EFAULT;
4523
4524         console_lock();
4525         for (i = k = 0; i < 16; i++) {
4526                 default_red[i] = colormap[k++];
4527                 default_grn[i] = colormap[k++];
4528                 default_blu[i] = colormap[k++];
4529         }
4530         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4531                 if (!vc_cons_allocated(i))
4532                         continue;
4533                 for (j = k = 0; j < 16; j++) {
4534                         vc_cons[i].d->vc_palette[k++] = default_red[j];
4535                         vc_cons[i].d->vc_palette[k++] = default_grn[j];
4536                         vc_cons[i].d->vc_palette[k++] = default_blu[j];
4537                 }
4538                 set_palette(vc_cons[i].d);
4539         }
4540         console_unlock();
4541
4542         return 0;
4543 }
4544
4545 int con_get_cmap(unsigned char __user *arg)
4546 {
4547         int i, k;
4548         unsigned char colormap[3*16];
4549
4550         console_lock();
4551         for (i = k = 0; i < 16; i++) {
4552                 colormap[k++] = default_red[i];
4553                 colormap[k++] = default_grn[i];
4554                 colormap[k++] = default_blu[i];
4555         }
4556         console_unlock();
4557
4558         if (copy_to_user(arg, colormap, sizeof(colormap)))
4559                 return -EFAULT;
4560
4561         return 0;
4562 }
4563
4564 void reset_palette(struct vc_data *vc)
4565 {
4566         int j, k;
4567         for (j=k=0; j<16; j++) {
4568                 vc->vc_palette[k++] = default_red[j];
4569                 vc->vc_palette[k++] = default_grn[j];
4570                 vc->vc_palette[k++] = default_blu[j];
4571         }
4572         set_palette(vc);
4573 }
4574
4575 /*
4576  *  Font switching
4577  *
4578  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4579  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4580  *  depending on width) reserved for each character which is kinda wasty, but
4581  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4582  *  is up to the actual low-level console-driver convert data into its favorite
4583  *  format (maybe we should add a `fontoffset' field to the `display'
4584  *  structure so we won't have to convert the fontdata all the time.
4585  *  /Jes
4586  */
4587
4588 #define max_font_size 65536
4589
4590 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4591 {
4592         struct console_font font;
4593         int rc = -EINVAL;
4594         int c;
4595
4596         if (op->data) {
4597                 font.data = kmalloc(max_font_size, GFP_KERNEL);
4598                 if (!font.data)
4599                         return -ENOMEM;
4600         } else
4601                 font.data = NULL;
4602
4603         console_lock();
4604         if (vc->vc_mode != KD_TEXT)
4605                 rc = -EINVAL;
4606         else if (vc->vc_sw->con_font_get)
4607                 rc = vc->vc_sw->con_font_get(vc, &font);
4608         else
4609                 rc = -ENOSYS;
4610         console_unlock();
4611
4612         if (rc)
4613                 goto out;
4614
4615         c = (font.width+7)/8 * 32 * font.charcount;
4616
4617         if (op->data && font.charcount > op->charcount)
4618                 rc = -ENOSPC;
4619         if (font.width > op->width || font.height > op->height)
4620                 rc = -ENOSPC;
4621         if (rc)
4622                 goto out;
4623
4624         op->height = font.height;
4625         op->width = font.width;
4626         op->charcount = font.charcount;
4627
4628         if (op->data && copy_to_user(op->data, font.data, c))
4629                 rc = -EFAULT;
4630
4631 out:
4632         kfree(font.data);
4633         return rc;
4634 }
4635
4636 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4637 {
4638         struct console_font font;
4639         int rc = -EINVAL;
4640         int size;
4641
4642         if (vc->vc_mode != KD_TEXT)
4643                 return -EINVAL;
4644         if (!op->data)
4645                 return -EINVAL;
4646         if (op->charcount > 512)
4647                 return -EINVAL;
4648         if (op->width <= 0 || op->width > 32 || !op->height || op->height > 32)
4649                 return -EINVAL;
4650         size = (op->width+7)/8 * 32 * op->charcount;
4651         if (size > max_font_size)
4652                 return -ENOSPC;
4653
4654         font.data = memdup_user(op->data, size);
4655         if (IS_ERR(font.data))
4656                 return PTR_ERR(font.data);
4657
4658         font.charcount = op->charcount;
4659         font.width = op->width;
4660         font.height = op->height;
4661
4662         console_lock();
4663         if (vc->vc_mode != KD_TEXT)
4664                 rc = -EINVAL;
4665         else if (vc->vc_sw->con_font_set) {
4666                 if (vc_is_sel(vc))
4667                         clear_selection();
4668                 rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4669         } else
4670                 rc = -ENOSYS;
4671         console_unlock();
4672         kfree(font.data);
4673         return rc;
4674 }
4675
4676 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4677 {
4678         struct console_font font = {.width = op->width, .height = op->height};
4679         char name[MAX_FONT_NAME];
4680         char *s = name;
4681         int rc;
4682
4683
4684         if (!op->data)
4685                 s = NULL;
4686         else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4687                 return -EFAULT;
4688         else
4689                 name[MAX_FONT_NAME - 1] = 0;
4690
4691         console_lock();
4692         if (vc->vc_mode != KD_TEXT) {
4693                 console_unlock();
4694                 return -EINVAL;
4695         }
4696         if (vc->vc_sw->con_font_default) {
4697                 if (vc_is_sel(vc))
4698                         clear_selection();
4699                 rc = vc->vc_sw->con_font_default(vc, &font, s);
4700         } else
4701                 rc = -ENOSYS;
4702         console_unlock();
4703         if (!rc) {
4704                 op->width = font.width;
4705                 op->height = font.height;
4706         }
4707         return rc;
4708 }
4709
4710 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4711 {
4712         switch (op->op) {
4713         case KD_FONT_OP_SET:
4714                 return con_font_set(vc, op);
4715         case KD_FONT_OP_GET:
4716                 return con_font_get(vc, op);
4717         case KD_FONT_OP_SET_DEFAULT:
4718                 return con_font_default(vc, op);
4719         case KD_FONT_OP_COPY:
4720                 /* was buggy and never really used */
4721                 return -EINVAL;
4722         }
4723         return -ENOSYS;
4724 }
4725
4726 /*
4727  *      Interface exported to selection and vcs.
4728  */
4729
4730 /* used by selection */
4731 u16 screen_glyph(const struct vc_data *vc, int offset)
4732 {
4733         u16 w = scr_readw(screenpos(vc, offset, true));
4734         u16 c = w & 0xff;
4735
4736         if (w & vc->vc_hi_font_mask)
4737                 c |= 0x100;
4738         return c;
4739 }
4740 EXPORT_SYMBOL_GPL(screen_glyph);
4741
4742 u32 screen_glyph_unicode(const struct vc_data *vc, int n)
4743 {
4744         struct uni_screen *uniscr = get_vc_uniscr(vc);
4745
4746         if (uniscr)
4747                 return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4748         return inverse_translate(vc, screen_glyph(vc, n * 2), true);
4749 }
4750 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4751
4752 /* used by vcs - note the word offset */
4753 unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
4754 {
4755         return screenpos(vc, 2 * w_offset, viewed);
4756 }
4757 EXPORT_SYMBOL_GPL(screen_pos);
4758
4759 void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
4760 {
4761         /* clamp values if they don't fit */
4762         xy[0] = min(vc->state.x, 0xFFu);
4763         xy[1] = min(vc->state.y, 0xFFu);
4764 }
4765
4766 void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
4767 {
4768         hide_cursor(vc);
4769         gotoxy(vc, xy[0], xy[1]);
4770         set_cursor(vc);
4771 }
4772
4773 u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
4774 {
4775         if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4776                 return softcursor_original;
4777         return scr_readw(org);
4778 }
4779
4780 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4781 {
4782         scr_writew(val, org);
4783         if ((unsigned long)org == vc->vc_pos) {
4784                 softcursor_original = -1;
4785                 add_softcursor(vc);
4786         }
4787 }
4788
4789 void vcs_scr_updated(struct vc_data *vc)
4790 {
4791         notify_update(vc);
4792 }
4793
4794 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4795                 unsigned int rolled_over, void *base, unsigned int size)
4796 {
4797         unsigned long ubase = (unsigned long)base;
4798         ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4799         ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4800         ptrdiff_t origin = (void *)c->vc_origin - base;
4801         int margin = c->vc_size_row * 4;
4802         int from, wrap, from_off, avail;
4803
4804         /* Turn scrollback off */
4805         if (!lines) {
4806                 c->vc_visible_origin = c->vc_origin;
4807                 return;
4808         }
4809
4810         /* Do we have already enough to allow jumping from 0 to the end? */
4811         if (rolled_over > scr_end + margin) {
4812                 from = scr_end;
4813                 wrap = rolled_over + c->vc_size_row;
4814         } else {
4815                 from = 0;
4816                 wrap = size;
4817         }
4818
4819         from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4820         avail = (origin - from + wrap) % wrap;
4821
4822         /* Only a little piece would be left? Show all incl. the piece! */
4823         if (avail < 2 * margin)
4824                 margin = 0;
4825         if (from_off < margin)
4826                 from_off = 0;
4827         if (from_off > avail - margin)
4828                 from_off = avail;
4829
4830         c->vc_visible_origin = ubase + (from + from_off) % wrap;
4831 }
4832 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4833
4834 /*
4835  *      Visible symbols for modules
4836  */
4837
4838 EXPORT_SYMBOL(color_table);
4839 EXPORT_SYMBOL(default_red);
4840 EXPORT_SYMBOL(default_grn);
4841 EXPORT_SYMBOL(default_blu);
4842 EXPORT_SYMBOL(update_region);
4843 EXPORT_SYMBOL(redraw_screen);
4844 EXPORT_SYMBOL(vc_resize);
4845 EXPORT_SYMBOL(fg_console);
4846 EXPORT_SYMBOL(console_blank_hook);
4847 EXPORT_SYMBOL(console_blanked);
4848 EXPORT_SYMBOL(vc_cons);
4849 EXPORT_SYMBOL(global_cursor_default);
4850 #ifndef VT_SINGLE_DRIVER
4851 EXPORT_SYMBOL(give_up_console);
4852 #endif