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/major.h>
  85 #include <linux/mm.h>
  86 #include <linux/console.h>
  87 #include <linux/init.h>
  88 #include <linux/mutex.h>
  89 #include <linux/vt_kern.h>
  90 #include <linux/selection.h>
  91 #include <linux/tiocl.h>
  92 #include <linux/kbd_kern.h>
  93 #include <linux/consolemap.h>
  94 #include <linux/timer.h>
  95 #include <linux/interrupt.h>
  96 #include <linux/workqueue.h>
  97 #include <linux/pm.h>
  98 #include <linux/font.h>
  99 #include <linux/bitops.h>
 100 #include <linux/notifier.h>
 101 #include <linux/device.h>
 102 #include <linux/io.h>
 103 #include <linux/uaccess.h>
 104 #include <linux/kdb.h>
 105 #include <linux/ctype.h>
 106 #include <linux/bsearch.h>
 107 #include <linux/gcd.h>
 108
 109 #define MAX_NR_CON_DRIVER 16
 110
 111 #define CON_DRIVER_FLAG_MODULE 1
 112 #define CON_DRIVER_FLAG_INIT   2
 113 #define CON_DRIVER_FLAG_ATTR   4
 114 #define CON_DRIVER_FLAG_ZOMBIE 8
 115
 116 struct con_driver {
 117         const struct consw *con;
 118         const char *desc;
 119         struct device *dev;
 120         int node;
 121         int first;
 122         int last;
 123         int flag;
 124 };
 125
 126 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
 127 const struct consw *conswitchp;
 128
 129 /* A bitmap for codes <32. A bit of 1 indicates that the code
 130  * corresponding to that bit number invokes some special action
 131  * (such as cursor movement) and should not be displayed as a
 132  * glyph unless the disp_ctrl mode is explicitly enabled.
 133  */
 134 #define CTRL_ACTION 0x0d00ff81
 135 #define CTRL_ALWAYS 0x0800f501  /* Cannot be overridden by disp_ctrl */
 136
 137 /*
 138  * Here is the default bell parameters: 750HZ, 1/8th of a second
 139  */
 140 #define DEFAULT_BELL_PITCH      750
 141 #define DEFAULT_BELL_DURATION   (HZ/8)
 142 #define DEFAULT_CURSOR_BLINK_MS 200
 143
 144 struct vc vc_cons [MAX_NR_CONSOLES];
 145
 146 #ifndef VT_SINGLE_DRIVER
 147 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
 148 #endif
 149
 150 static int con_open(struct tty_struct *, struct file *);
 151 static void vc_init(struct vc_data *vc, unsigned int rows,
 152                     unsigned int cols, int do_clear);
 153 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
 154 static void save_cur(struct vc_data *vc);
 155 static void reset_terminal(struct vc_data *vc, int do_clear);
 156 static void con_flush_chars(struct tty_struct *tty);
 157 static int set_vesa_blanking(char __user *p);
 158 static void set_cursor(struct vc_data *vc);
 159 static void hide_cursor(struct vc_data *vc);
 160 static void console_callback(struct work_struct *ignored);
 161 static void con_driver_unregister_callback(struct work_struct *ignored);
 162 static void blank_screen_t(struct timer_list *unused);
 163 static void set_palette(struct vc_data *vc);
 164
 165 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 166
 167 static int printable;           /* Is console ready for printing? */
 168 int default_utf8 = true;
 169 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 170 int global_cursor_default = -1;
 171 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
 172
 173 static int cur_default = CUR_DEFAULT;
 174 module_param(cur_default, int, S_IRUGO | S_IWUSR);
 175
 176 /*
 177  * ignore_poke: don't unblank the screen when things are typed.  This is
 178  * mainly for the privacy of braille terminal users.
 179  */
 180 static int ignore_poke;
 181
 182 int do_poke_blanked_console;
 183 int console_blanked;
 184
 185 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
 186 static int vesa_off_interval;
 187 static int blankinterval;
 188 core_param(consoleblank, blankinterval, int, 0444);
 189
 190 static DECLARE_WORK(console_work, console_callback);
 191 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
 192
 193 /*
 194  * fg_console is the current virtual console,
 195  * last_console is the last used one,
 196  * want_console is the console we want to switch to,
 197  * saved_* variants are for save/restore around kernel debugger enter/leave
 198  */
 199 int fg_console;
 200 int last_console;
 201 int want_console = -1;
 202 static int saved_fg_console;
 203 static int saved_last_console;
 204 static int saved_want_console;
 205 static int saved_vc_mode;
 206 static int saved_console_blanked;
 207
 208 /*
 209  * For each existing display, we have a pointer to console currently visible
 210  * on that display, allowing consoles other than fg_console to be refreshed
 211  * appropriately. Unless the low-level driver supplies its own display_fg
 212  * variable, we use this one for the "master display".
 213  */
 214 static struct vc_data *master_display_fg;
 215
 216 /*
 217  * Unfortunately, we need to delay tty echo when we're currently writing to the
 218  * console since the code is (and always was) not re-entrant, so we schedule
 219  * all flip requests to process context with schedule-task() and run it from
 220  * console_callback().
 221  */
 222
 223 /*
 224  * For the same reason, we defer scrollback to the console callback.
 225  */
 226 static int scrollback_delta;
 227
 228 /*
 229  * Hook so that the power management routines can (un)blank
 230  * the console on our behalf.
 231  */
 232 int (*console_blank_hook)(int);
 233
 234 static DEFINE_TIMER(console_timer, blank_screen_t);
 235 static int blank_state;
 236 static int blank_timer_expired;
 237 enum {
 238         blank_off = 0,
 239         blank_normal_wait,
 240         blank_vesa_wait,
 241 };
 242
 243 /*
 244  * /sys/class/tty/tty0/
 245  *
 246  * the attribute 'active' contains the name of the current vc
 247  * console and it supports poll() to detect vc switches
 248  */
 249 static struct device *tty0dev;
 250
 251 /*
 252  * Notifier list for console events.
 253  */
 254 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
 255
 256 int register_vt_notifier(struct notifier_block *nb)
 257 {
 258         return atomic_notifier_chain_register(&vt_notifier_list, nb);
 259 }
 260 EXPORT_SYMBOL_GPL(register_vt_notifier);
 261
 262 int unregister_vt_notifier(struct notifier_block *nb)
 263 {
 264         return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
 265 }
 266 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
 267
 268 static void notify_write(struct vc_data *vc, unsigned int unicode)
 269 {
 270         struct vt_notifier_param param = { .vc = vc, .c = unicode };
 271         atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
 272 }
 273
 274 static void notify_update(struct vc_data *vc)
 275 {
 276         struct vt_notifier_param param = { .vc = vc };
 277         atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
 278 }
 279 /*
 280  *      Low-Level Functions
 281  */
 282
 283 static inline bool con_is_fg(const struct vc_data *vc)
 284 {
 285         return vc->vc_num == fg_console;
 286 }
 287
 288 static inline bool con_should_update(const struct vc_data *vc)
 289 {
 290         return con_is_visible(vc) && !console_blanked;
 291 }
 292
 293 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
 294 {
 295         unsigned short *p;
 296
 297         if (!viewed)
 298                 p = (unsigned short *)(vc->vc_origin + offset);
 299         else if (!vc->vc_sw->con_screen_pos)
 300                 p = (unsigned short *)(vc->vc_visible_origin + offset);
 301         else
 302                 p = vc->vc_sw->con_screen_pos(vc, offset);
 303         return p;
 304 }
 305
 306 /* Called  from the keyboard irq path.. */
 307 static inline void scrolldelta(int lines)
 308 {
 309         /* FIXME */
 310         /* scrolldelta needs some kind of consistency lock, but the BKL was
 311            and still is not protecting versus the scheduled back end */
 312         scrollback_delta += lines;
 313         schedule_console_callback();
 314 }
 315
 316 void schedule_console_callback(void)
 317 {
 318         schedule_work(&console_work);
 319 }
 320
 321 /*
 322  * Code to manage unicode-based screen buffers
 323  */
 324
 325 #ifdef NO_VC_UNI_SCREEN
 326 /* this disables and optimizes related code away at compile time */
 327 #define get_vc_uniscr(vc) NULL
 328 #else
 329 #define get_vc_uniscr(vc) vc->vc_uni_screen
 330 #endif
 331
 332 #define VC_UNI_SCREEN_DEBUG 0
 333
 334 typedef uint32_t char32_t;
 335
 336 /*
 337  * Our screen buffer is preceded by an array of line pointers so that
 338  * scrolling only implies some pointer shuffling.
 339  */
 340 struct uni_screen {
 341         char32_t *lines[0];
 342 };
 343
 344 static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
 345 {
 346         struct uni_screen *uniscr;
 347         void *p;
 348         unsigned int memsize, i;
 349
 350         /* allocate everything in one go */
 351         memsize = cols * rows * sizeof(char32_t);
 352         memsize += rows * sizeof(char32_t *);
 353         p = kmalloc(memsize, GFP_KERNEL);
 354         if (!p)
 355                 return NULL;
 356
 357         /* initial line pointers */
 358         uniscr = p;
 359         p = uniscr->lines + rows;
 360         for (i = 0; i < rows; i++) {
 361                 uniscr->lines[i] = p;
 362                 p += cols * sizeof(char32_t);
 363         }
 364         return uniscr;
 365 }
 366
 367 static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
 368 {
 369         kfree(vc->vc_uni_screen);
 370         vc->vc_uni_screen = new_uniscr;
 371 }
 372
 373 static void vc_uniscr_putc(struct vc_data *vc, char32_t uc)
 374 {
 375         struct uni_screen *uniscr = get_vc_uniscr(vc);
 376
 377         if (uniscr)
 378                 uniscr->lines[vc->vc_y][vc->vc_x] = uc;
 379 }
 380
 381 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
 382 {
 383         struct uni_screen *uniscr = get_vc_uniscr(vc);
 384
 385         if (uniscr) {
 386                 char32_t *ln = uniscr->lines[vc->vc_y];
 387                 unsigned int x = vc->vc_x, cols = vc->vc_cols;
 388
 389                 memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
 390                 memset32(&ln[x], ' ', nr);
 391         }
 392 }
 393
 394 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
 395 {
 396         struct uni_screen *uniscr = get_vc_uniscr(vc);
 397
 398         if (uniscr) {
 399                 char32_t *ln = uniscr->lines[vc->vc_y];
 400                 unsigned int x = vc->vc_x, cols = vc->vc_cols;
 401
 402                 memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
 403                 memset32(&ln[cols - nr], ' ', nr);
 404         }
 405 }
 406
 407 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
 408                                  unsigned int nr)
 409 {
 410         struct uni_screen *uniscr = get_vc_uniscr(vc);
 411
 412         if (uniscr) {
 413                 char32_t *ln = uniscr->lines[vc->vc_y];
 414
 415                 memset32(&ln[x], ' ', nr);
 416         }
 417 }
 418
 419 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
 420                                   unsigned int nr)
 421 {
 422         struct uni_screen *uniscr = get_vc_uniscr(vc);
 423
 424         if (uniscr) {
 425                 unsigned int cols = vc->vc_cols;
 426
 427                 while (nr--)
 428                         memset32(uniscr->lines[y++], ' ', cols);
 429         }
 430 }
 431
 432 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 433                              enum con_scroll dir, unsigned int nr)
 434 {
 435         struct uni_screen *uniscr = get_vc_uniscr(vc);
 436
 437         if (uniscr) {
 438                 unsigned int i, j, k, sz, d, clear;
 439
 440                 sz = b - t;
 441                 clear = b - nr;
 442                 d = nr;
 443                 if (dir == SM_DOWN) {
 444                         clear = t;
 445                         d = sz - nr;
 446                 }
 447                 for (i = 0; i < gcd(d, sz); i++) {
 448                         char32_t *tmp = uniscr->lines[t + i];
 449                         j = i;
 450                         while (1) {
 451                                 k = j + d;
 452                                 if (k >= sz)
 453                                         k -= sz;
 454                                 if (k == i)
 455                                         break;
 456                                 uniscr->lines[t + j] = uniscr->lines[t + k];
 457                                 j = k;
 458                         }
 459                         uniscr->lines[t + j] = tmp;
 460                 }
 461                 vc_uniscr_clear_lines(vc, clear, nr);
 462         }
 463 }
 464
 465 static void vc_uniscr_copy_area(struct uni_screen *dst,
 466                                 unsigned int dst_cols,
 467                                 unsigned int dst_rows,
 468                                 struct uni_screen *src,
 469                                 unsigned int src_cols,
 470                                 unsigned int src_top_row,
 471                                 unsigned int src_bot_row)
 472 {
 473         unsigned int dst_row = 0;
 474
 475         if (!dst)
 476                 return;
 477
 478         while (src_top_row < src_bot_row) {
 479                 char32_t *src_line = src->lines[src_top_row];
 480                 char32_t *dst_line = dst->lines[dst_row];
 481
 482                 memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
 483                 if (dst_cols - src_cols)
 484                         memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
 485                 src_top_row++;
 486                 dst_row++;
 487         }
 488         while (dst_row < dst_rows) {
 489                 char32_t *dst_line = dst->lines[dst_row];
 490
 491                 memset32(dst_line, ' ', dst_cols);
 492                 dst_row++;
 493         }
 494 }
 495
 496 /*
 497  * Called from vcs_read() to make sure unicode screen retrieval is possible.
 498  * This will initialize the unicode screen buffer if not already done.
 499  * This returns 0 if OK, or a negative error code otherwise.
 500  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
 501  */
 502 int vc_uniscr_check(struct vc_data *vc)
 503 {
 504         struct uni_screen *uniscr;
 505         unsigned short *p;
 506         int x, y, mask;
 507
 508         if (__is_defined(NO_VC_UNI_SCREEN))
 509                 return -EOPNOTSUPP;
 510
 511         WARN_CONSOLE_UNLOCKED();
 512
 513         if (!vc->vc_utf)
 514                 return -ENODATA;
 515
 516         if (vc->vc_uni_screen)
 517                 return 0;
 518
 519         uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
 520         if (!uniscr)
 521                 return -ENOMEM;
 522
 523         /*
 524          * Let's populate it initially with (imperfect) reverse translation.
 525          * This is the next best thing we can do short of having it enabled
 526          * from the start even when no users rely on this functionality. True
 527          * unicode content will be available after a complete screen refresh.
 528          */
 529         p = (unsigned short *)vc->vc_origin;
 530         mask = vc->vc_hi_font_mask | 0xff;
 531         for (y = 0; y < vc->vc_rows; y++) {
 532                 char32_t *line = uniscr->lines[y];
 533                 for (x = 0; x < vc->vc_cols; x++) {
 534                         u16 glyph = scr_readw(p++) & mask;
 535                         line[x] = inverse_translate(vc, glyph, true);
 536                 }
 537         }
 538
 539         vc->vc_uni_screen = uniscr;
 540         return 0;
 541 }
 542
 543 /*
 544  * Called from vcs_read() to get the unicode data from the screen.
 545  * This must be preceded by a successful call to vc_uniscr_check() once
 546  * the console lock has been taken.
 547  */
 548 void vc_uniscr_copy_line(struct vc_data *vc, void *dest, int viewed,
 549                          unsigned int row, unsigned int col, unsigned int nr)
 550 {
 551         struct uni_screen *uniscr = get_vc_uniscr(vc);
 552         int offset = row * vc->vc_size_row + col * 2;
 553         unsigned long pos;
 554
 555         BUG_ON(!uniscr);
 556
 557         pos = (unsigned long)screenpos(vc, offset, viewed);
 558         if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
 559                 /*
 560                  * Desired position falls in the main screen buffer.
 561                  * However the actual row/col might be different if
 562                  * scrollback is active.
 563                  */
 564                 row = (pos - vc->vc_origin) / vc->vc_size_row;
 565                 col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
 566                 memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t));
 567         } else {
 568                 /*
 569                  * Scrollback is active. For now let's simply backtranslate
 570                  * the screen glyphs until the unicode screen buffer does
 571                  * synchronize with console display drivers for a scrollback
 572                  * buffer of its own.
 573                  */
 574                 u16 *p = (u16 *)pos;
 575                 int mask = vc->vc_hi_font_mask | 0xff;
 576                 char32_t *uni_buf = dest;
 577                 while (nr--) {
 578                         u16 glyph = scr_readw(p++) & mask;
 579                         *uni_buf++ = inverse_translate(vc, glyph, true);
 580                 }
 581         }
 582 }
 583
 584 /* this is for validation and debugging only */
 585 static void vc_uniscr_debug_check(struct vc_data *vc)
 586 {
 587         struct uni_screen *uniscr = get_vc_uniscr(vc);
 588         unsigned short *p;
 589         int x, y, mask;
 590
 591         if (!VC_UNI_SCREEN_DEBUG || !uniscr)
 592                 return;
 593
 594         WARN_CONSOLE_UNLOCKED();
 595
 596         /*
 597          * Make sure our unicode screen translates into the same glyphs
 598          * as the actual screen. This is brutal indeed.
 599          */
 600         p = (unsigned short *)vc->vc_origin;
 601         mask = vc->vc_hi_font_mask | 0xff;
 602         for (y = 0; y < vc->vc_rows; y++) {
 603                 char32_t *line = uniscr->lines[y];
 604                 for (x = 0; x < vc->vc_cols; x++) {
 605                         u16 glyph = scr_readw(p++) & mask;
 606                         char32_t uc = line[x];
 607                         int tc = conv_uni_to_pc(vc, uc);
 608                         if (tc == -4)
 609                                 tc = conv_uni_to_pc(vc, 0xfffd);
 610                         if (tc == -4)
 611                                 tc = conv_uni_to_pc(vc, '?');
 612                         if (tc != glyph)
 613                                 pr_err_ratelimited(
 614                                         "%s: mismatch at %d,%d: glyph=%#x tc=%#x\n",
 615                                         __func__, x, y, glyph, tc);
 616                 }
 617         }
 618 }
 619
 620
 621 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 622                 enum con_scroll dir, unsigned int nr)
 623 {
 624         u16 *clear, *d, *s;
 625
 626         if (t + nr >= b)
 627                 nr = b - t - 1;
 628         if (b > vc->vc_rows || t >= b || nr < 1)
 629                 return;
 630         vc_uniscr_scroll(vc, t, b, dir, nr);
 631         if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
 632                 return;
 633
 634         s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
 635         d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
 636
 637         if (dir == SM_UP) {
 638                 clear = s + (b - t - nr) * vc->vc_cols;
 639                 swap(s, d);
 640         }
 641         scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
 642         scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
 643 }
 644
 645 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 646 {
 647         unsigned int xx, yy, offset;
 648         u16 *p;
 649
 650         p = (u16 *) start;
 651         if (!vc->vc_sw->con_getxy) {
 652                 offset = (start - vc->vc_origin) / 2;
 653                 xx = offset % vc->vc_cols;
 654                 yy = offset / vc->vc_cols;
 655         } else {
 656                 int nxx, nyy;
 657                 start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
 658                 xx = nxx; yy = nyy;
 659         }
 660         for(;;) {
 661                 u16 attrib = scr_readw(p) & 0xff00;
 662                 int startx = xx;
 663                 u16 *q = p;
 664                 while (xx < vc->vc_cols && count) {
 665                         if (attrib != (scr_readw(p) & 0xff00)) {
 666                                 if (p > q)
 667                                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 668                                 startx = xx;
 669                                 q = p;
 670                                 attrib = scr_readw(p) & 0xff00;
 671                         }
 672                         p++;
 673                         xx++;
 674                         count--;
 675                 }
 676                 if (p > q)
 677                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 678                 if (!count)
 679                         break;
 680                 xx = 0;
 681                 yy++;
 682                 if (vc->vc_sw->con_getxy) {
 683                         p = (u16 *)start;
 684                         start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
 685                 }
 686         }
 687 }
 688
 689 void update_region(struct vc_data *vc, unsigned long start, int count)
 690 {
 691         WARN_CONSOLE_UNLOCKED();
 692
 693         if (con_should_update(vc)) {
 694                 hide_cursor(vc);
 695                 do_update_region(vc, start, count);
 696                 set_cursor(vc);
 697         }
 698 }
 699
 700 /* Structure of attributes is hardware-dependent */
 701
 702 static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
 703     u8 _underline, u8 _reverse, u8 _italic)
 704 {
 705         if (vc->vc_sw->con_build_attr)
 706                 return vc->vc_sw->con_build_attr(vc, _color, _intensity,
 707                        _blink, _underline, _reverse, _italic);
 708
 709 /*
 710  * ++roman: I completely changed the attribute format for monochrome
 711  * mode (!can_do_color). The formerly used MDA (monochrome display
 712  * adapter) format didn't allow the combination of certain effects.
 713  * Now the attribute is just a bit vector:
 714  *  Bit 0..1: intensity (0..2)
 715  *  Bit 2   : underline
 716  *  Bit 3   : reverse
 717  *  Bit 7   : blink
 718  */
 719         {
 720         u8 a = _color;
 721         if (!vc->vc_can_do_color)
 722                 return _intensity |
 723                        (_italic ? 2 : 0) |
 724                        (_underline ? 4 : 0) |
 725                        (_reverse ? 8 : 0) |
 726                        (_blink ? 0x80 : 0);
 727         if (_italic)
 728                 a = (a & 0xF0) | vc->vc_itcolor;
 729         else if (_underline)
 730                 a = (a & 0xf0) | vc->vc_ulcolor;
 731         else if (_intensity == 0)
 732                 a = (a & 0xf0) | vc->vc_halfcolor;
 733         if (_reverse)
 734                 a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
 735         if (_blink)
 736                 a ^= 0x80;
 737         if (_intensity == 2)
 738                 a ^= 0x08;
 739         if (vc->vc_hi_font_mask == 0x100)
 740                 a <<= 1;
 741         return a;
 742         }
 743 }
 744
 745 static void update_attr(struct vc_data *vc)
 746 {
 747         vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
 748                       vc->vc_blink, vc->vc_underline,
 749                       vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
 750         vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
 751 }
 752
 753 /* Note: inverting the screen twice should revert to the original state */
 754 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
 755 {
 756         unsigned short *p;
 757
 758         WARN_CONSOLE_UNLOCKED();
 759
 760         count /= 2;
 761         p = screenpos(vc, offset, viewed);
 762         if (vc->vc_sw->con_invert_region) {
 763                 vc->vc_sw->con_invert_region(vc, p, count);
 764         } else {
 765                 u16 *q = p;
 766                 int cnt = count;
 767                 u16 a;
 768
 769                 if (!vc->vc_can_do_color) {
 770                         while (cnt--) {
 771                             a = scr_readw(q);
 772                             a ^= 0x0800;
 773                             scr_writew(a, q);
 774                             q++;
 775                         }
 776                 } else if (vc->vc_hi_font_mask == 0x100) {
 777                         while (cnt--) {
 778                                 a = scr_readw(q);
 779                                 a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
 780                                 scr_writew(a, q);
 781                                 q++;
 782                         }
 783                 } else {
 784                         while (cnt--) {
 785                                 a = scr_readw(q);
 786                                 a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
 787                                 scr_writew(a, q);
 788                                 q++;
 789                         }
 790                 }
 791         }
 792
 793         if (con_should_update(vc))
 794                 do_update_region(vc, (unsigned long) p, count);
 795         notify_update(vc);
 796 }
 797
 798 /* used by selection: complement pointer position */
 799 void complement_pos(struct vc_data *vc, int offset)
 800 {
 801         static int old_offset = -1;
 802         static unsigned short old;
 803         static unsigned short oldx, oldy;
 804
 805         WARN_CONSOLE_UNLOCKED();
 806
 807         if (old_offset != -1 && old_offset >= 0 &&
 808             old_offset < vc->vc_screenbuf_size) {
 809                 scr_writew(old, screenpos(vc, old_offset, 1));
 810                 if (con_should_update(vc))
 811                         vc->vc_sw->con_putc(vc, old, oldy, oldx);
 812                 notify_update(vc);
 813         }
 814
 815         old_offset = offset;
 816
 817         if (offset != -1 && offset >= 0 &&
 818             offset < vc->vc_screenbuf_size) {
 819                 unsigned short new;
 820                 unsigned short *p;
 821                 p = screenpos(vc, offset, 1);
 822                 old = scr_readw(p);
 823                 new = old ^ vc->vc_complement_mask;
 824                 scr_writew(new, p);
 825                 if (con_should_update(vc)) {
 826                         oldx = (offset >> 1) % vc->vc_cols;
 827                         oldy = (offset >> 1) / vc->vc_cols;
 828                         vc->vc_sw->con_putc(vc, new, oldy, oldx);
 829                 }
 830                 notify_update(vc);
 831         }
 832 }
 833
 834 static void insert_char(struct vc_data *vc, unsigned int nr)
 835 {
 836         unsigned short *p = (unsigned short *) vc->vc_pos;
 837
 838         vc_uniscr_insert(vc, nr);
 839         scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
 840         scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
 841         vc->vc_need_wrap = 0;
 842         if (con_should_update(vc))
 843                 do_update_region(vc, (unsigned long) p,
 844                         vc->vc_cols - vc->vc_x);
 845 }
 846
 847 static void delete_char(struct vc_data *vc, unsigned int nr)
 848 {
 849         unsigned short *p = (unsigned short *) vc->vc_pos;
 850
 851         vc_uniscr_delete(vc, nr);
 852         scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
 853         scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
 854                         nr * 2);
 855         vc->vc_need_wrap = 0;
 856         if (con_should_update(vc))
 857                 do_update_region(vc, (unsigned long) p,
 858                         vc->vc_cols - vc->vc_x);
 859 }
 860
 861 static int softcursor_original = -1;
 862
 863 static void add_softcursor(struct vc_data *vc)
 864 {
 865         int i = scr_readw((u16 *) vc->vc_pos);
 866         u32 type = vc->vc_cursor_type;
 867
 868         if (! (type & 0x10)) return;
 869         if (softcursor_original != -1) return;
 870         softcursor_original = i;
 871         i |= ((type >> 8) & 0xff00 );
 872         i ^= ((type) & 0xff00 );
 873         if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
 874         if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
 875         scr_writew(i, (u16 *) vc->vc_pos);
 876         if (con_should_update(vc))
 877                 vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
 878 }
 879
 880 static void hide_softcursor(struct vc_data *vc)
 881 {
 882         if (softcursor_original != -1) {
 883                 scr_writew(softcursor_original, (u16 *)vc->vc_pos);
 884                 if (con_should_update(vc))
 885                         vc->vc_sw->con_putc(vc, softcursor_original,
 886                                         vc->vc_y, vc->vc_x);
 887                 softcursor_original = -1;
 888         }
 889 }
 890
 891 static void hide_cursor(struct vc_data *vc)
 892 {
 893         if (vc == sel_cons)
 894                 clear_selection();
 895         vc->vc_sw->con_cursor(vc, CM_ERASE);
 896         hide_softcursor(vc);
 897 }
 898
 899 static void set_cursor(struct vc_data *vc)
 900 {
 901         if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
 902                 return;
 903         if (vc->vc_deccm) {
 904                 if (vc == sel_cons)
 905                         clear_selection();
 906                 add_softcursor(vc);
 907                 if ((vc->vc_cursor_type & 0x0f) != 1)
 908                         vc->vc_sw->con_cursor(vc, CM_DRAW);
 909         } else
 910                 hide_cursor(vc);
 911 }
 912
 913 static void set_origin(struct vc_data *vc)
 914 {
 915         WARN_CONSOLE_UNLOCKED();
 916
 917         if (!con_is_visible(vc) ||
 918             !vc->vc_sw->con_set_origin ||
 919             !vc->vc_sw->con_set_origin(vc))
 920                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
 921         vc->vc_visible_origin = vc->vc_origin;
 922         vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
 923         vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
 924 }
 925
 926 static void save_screen(struct vc_data *vc)
 927 {
 928         WARN_CONSOLE_UNLOCKED();
 929
 930         if (vc->vc_sw->con_save_screen)
 931                 vc->vc_sw->con_save_screen(vc);
 932 }
 933
 934 static void flush_scrollback(struct vc_data *vc)
 935 {
 936         WARN_CONSOLE_UNLOCKED();
 937
 938         set_origin(vc);
 939         if (vc->vc_sw->con_flush_scrollback)
 940                 vc->vc_sw->con_flush_scrollback(vc);
 941         else
 942                 vc->vc_sw->con_switch(vc);
 943 }
 944
 945 /*
 946  *      Redrawing of screen
 947  */
 948
 949 void clear_buffer_attributes(struct vc_data *vc)
 950 {
 951         unsigned short *p = (unsigned short *)vc->vc_origin;
 952         int count = vc->vc_screenbuf_size / 2;
 953         int mask = vc->vc_hi_font_mask | 0xff;
 954
 955         for (; count > 0; count--, p++) {
 956                 scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
 957         }
 958 }
 959
 960 void redraw_screen(struct vc_data *vc, int is_switch)
 961 {
 962         int redraw = 0;
 963
 964         WARN_CONSOLE_UNLOCKED();
 965
 966         if (!vc) {
 967                 /* strange ... */
 968                 /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
 969                 return;
 970         }
 971
 972         if (is_switch) {
 973                 struct vc_data *old_vc = vc_cons[fg_console].d;
 974                 if (old_vc == vc)
 975                         return;
 976                 if (!con_is_visible(vc))
 977                         redraw = 1;
 978                 *vc->vc_display_fg = vc;
 979                 fg_console = vc->vc_num;
 980                 hide_cursor(old_vc);
 981                 if (!con_is_visible(old_vc)) {
 982                         save_screen(old_vc);
 983                         set_origin(old_vc);
 984                 }
 985                 if (tty0dev)
 986                         sysfs_notify(&tty0dev->kobj, NULL, "active");
 987         } else {
 988                 hide_cursor(vc);
 989                 redraw = 1;
 990         }
 991
 992         if (redraw) {
 993                 int update;
 994                 int old_was_color = vc->vc_can_do_color;
 995
 996                 set_origin(vc);
 997                 update = vc->vc_sw->con_switch(vc);
 998                 set_palette(vc);
 999                 /*
1000                  * If console changed from mono<->color, the best we can do
1001                  * is to clear the buffer attributes. As it currently stands,
1002                  * rebuilding new attributes from the old buffer is not doable
1003                  * without overly complex code.
1004                  */
1005                 if (old_was_color != vc->vc_can_do_color) {
1006                         update_attr(vc);
1007                         clear_buffer_attributes(vc);
1008                 }
1009
1010                 if (update && vc->vc_mode != KD_GRAPHICS)
1011                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1012         }
1013         set_cursor(vc);
1014         if (is_switch) {
1015                 set_leds();
1016                 compute_shiftstate();
1017                 notify_update(vc);
1018         }
1019 }
1020
1021 /*
1022  *      Allocation, freeing and resizing of VTs.
1023  */
1024
1025 int vc_cons_allocated(unsigned int i)
1026 {
1027         return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1028 }
1029
1030 static void visual_init(struct vc_data *vc, int num, int init)
1031 {
1032         /* ++Geert: vc->vc_sw->con_init determines console size */
1033         if (vc->vc_sw)
1034                 module_put(vc->vc_sw->owner);
1035         vc->vc_sw = conswitchp;
1036 #ifndef VT_SINGLE_DRIVER
1037         if (con_driver_map[num])
1038                 vc->vc_sw = con_driver_map[num];
1039 #endif
1040         __module_get(vc->vc_sw->owner);
1041         vc->vc_num = num;
1042         vc->vc_display_fg = &master_display_fg;
1043         if (vc->vc_uni_pagedir_loc)
1044                 con_free_unimap(vc);
1045         vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
1046         vc->vc_uni_pagedir = NULL;
1047         vc->vc_hi_font_mask = 0;
1048         vc->vc_complement_mask = 0;
1049         vc->vc_can_do_color = 0;
1050         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1051         vc->vc_sw->con_init(vc, init);
1052         if (!vc->vc_complement_mask)
1053                 vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1054         vc->vc_s_complement_mask = vc->vc_complement_mask;
1055         vc->vc_size_row = vc->vc_cols << 1;
1056         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1057 }
1058
1059 int vc_allocate(unsigned int currcons)  /* return 0 on success */
1060 {
1061         struct vt_notifier_param param;
1062         struct vc_data *vc;
1063
1064         WARN_CONSOLE_UNLOCKED();
1065
1066         if (currcons >= MAX_NR_CONSOLES)
1067                 return -ENXIO;
1068
1069         if (vc_cons[currcons].d)
1070                 return 0;
1071
1072         /* due to the granularity of kmalloc, we waste some memory here */
1073         /* the alloc is done in two steps, to optimize the common situation
1074            of a 25x80 console (structsize=216, screenbuf_size=4000) */
1075         /* although the numbers above are not valid since long ago, the
1076            point is still up-to-date and the comment still has its value
1077            even if only as a historical artifact.  --mj, July 1998 */
1078         param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1079         if (!vc)
1080                 return -ENOMEM;
1081
1082         vc_cons[currcons].d = vc;
1083         tty_port_init(&vc->port);
1084         INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1085
1086         visual_init(vc, currcons, 1);
1087
1088         if (!*vc->vc_uni_pagedir_loc)
1089                 con_set_default_unimap(vc);
1090
1091         vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1092         if (!vc->vc_screenbuf)
1093                 goto err_free;
1094
1095         /* If no drivers have overridden us and the user didn't pass a
1096            boot option, default to displaying the cursor */
1097         if (global_cursor_default == -1)
1098                 global_cursor_default = 1;
1099
1100         vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
1101         vcs_make_sysfs(currcons);
1102         atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1103
1104         return 0;
1105 err_free:
1106         kfree(vc);
1107         vc_cons[currcons].d = NULL;
1108         return -ENOMEM;
1109 }
1110
1111 static inline int resize_screen(struct vc_data *vc, int width, int height,
1112                                 int user)
1113 {
1114         /* Resizes the resolution of the display adapater */
1115         int err = 0;
1116
1117         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
1118                 err = vc->vc_sw->con_resize(vc, width, height, user);
1119
1120         return err;
1121 }
1122
1123 /*
1124  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1125  * [this is to be used together with some user program
1126  * like resize that changes the hardware videomode]
1127  */
1128 #define VC_RESIZE_MAXCOL (32767)
1129 #define VC_RESIZE_MAXROW (32767)
1130
1131 /**
1132  *      vc_do_resize    -       resizing method for the tty
1133  *      @tty: tty being resized
1134  *      @real_tty: real tty (different to tty if a pty/tty pair)
1135  *      @vc: virtual console private data
1136  *      @cols: columns
1137  *      @lines: lines
1138  *
1139  *      Resize a virtual console, clipping according to the actual constraints.
1140  *      If the caller passes a tty structure then update the termios winsize
1141  *      information and perform any necessary signal handling.
1142  *
1143  *      Caller must hold the console semaphore. Takes the termios rwsem and
1144  *      ctrl_lock of the tty IFF a tty is passed.
1145  */
1146
1147 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1148                                 unsigned int cols, unsigned int lines)
1149 {
1150         unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1151         unsigned long end;
1152         unsigned int old_rows, old_row_size, first_copied_row;
1153         unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1154         unsigned int user;
1155         unsigned short *newscreen;
1156         struct uni_screen *new_uniscr = NULL;
1157
1158         WARN_CONSOLE_UNLOCKED();
1159
1160         if (!vc)
1161                 return -ENXIO;
1162
1163         user = vc->vc_resize_user;
1164         vc->vc_resize_user = 0;
1165
1166         if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
1167                 return -EINVAL;
1168
1169         new_cols = (cols ? cols : vc->vc_cols);
1170         new_rows = (lines ? lines : vc->vc_rows);
1171         new_row_size = new_cols << 1;
1172         new_screen_size = new_row_size * new_rows;
1173
1174         if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
1175                 return 0;
1176
1177         if (new_screen_size > (4 << 20))
1178                 return -EINVAL;
1179         newscreen = kzalloc(new_screen_size, GFP_USER);
1180         if (!newscreen)
1181                 return -ENOMEM;
1182
1183         if (get_vc_uniscr(vc)) {
1184                 new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1185                 if (!new_uniscr) {
1186                         kfree(newscreen);
1187                         return -ENOMEM;
1188                 }
1189         }
1190
1191         if (vc == sel_cons)
1192                 clear_selection();
1193
1194         old_rows = vc->vc_rows;
1195         old_row_size = vc->vc_size_row;
1196
1197         err = resize_screen(vc, new_cols, new_rows, user);
1198         if (err) {
1199                 kfree(newscreen);
1200                 kfree(new_uniscr);
1201                 return err;
1202         }
1203
1204         vc->vc_rows = new_rows;
1205         vc->vc_cols = new_cols;
1206         vc->vc_size_row = new_row_size;
1207         vc->vc_screenbuf_size = new_screen_size;
1208
1209         rlth = min(old_row_size, new_row_size);
1210         rrem = new_row_size - rlth;
1211         old_origin = vc->vc_origin;
1212         new_origin = (long) newscreen;
1213         new_scr_end = new_origin + new_screen_size;
1214
1215         if (vc->vc_y > new_rows) {
1216                 if (old_rows - vc->vc_y < new_rows) {
1217                         /*
1218                          * Cursor near the bottom, copy contents from the
1219                          * bottom of buffer
1220                          */
1221                         first_copied_row = (old_rows - new_rows);
1222                 } else {
1223                         /*
1224                          * Cursor is in no man's land, copy 1/2 screenful
1225                          * from the top and bottom of cursor position
1226                          */
1227                         first_copied_row = (vc->vc_y - new_rows/2);
1228                 }
1229                 old_origin += first_copied_row * old_row_size;
1230         } else
1231                 first_copied_row = 0;
1232         end = old_origin + old_row_size * min(old_rows, new_rows);
1233
1234         vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1235                             get_vc_uniscr(vc), rlth/2, first_copied_row,
1236                             min(old_rows, new_rows));
1237         vc_uniscr_set(vc, new_uniscr);
1238
1239         update_attr(vc);
1240
1241         while (old_origin < end) {
1242                 scr_memcpyw((unsigned short *) new_origin,
1243                             (unsigned short *) old_origin, rlth);
1244                 if (rrem)
1245                         scr_memsetw((void *)(new_origin + rlth),
1246                                     vc->vc_video_erase_char, rrem);
1247                 old_origin += old_row_size;
1248                 new_origin += new_row_size;
1249         }
1250         if (new_scr_end > new_origin)
1251                 scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1252                             new_scr_end - new_origin);
1253         kfree(vc->vc_screenbuf);
1254         vc->vc_screenbuf = newscreen;
1255         vc->vc_screenbuf_size = new_screen_size;
1256         set_origin(vc);
1257
1258         /* do part of a reset_terminal() */
1259         vc->vc_top = 0;
1260         vc->vc_bottom = vc->vc_rows;
1261         gotoxy(vc, vc->vc_x, vc->vc_y);
1262         save_cur(vc);
1263
1264         if (tty) {
1265                 /* Rewrite the requested winsize data with the actual
1266                    resulting sizes */
1267                 struct winsize ws;
1268                 memset(&ws, 0, sizeof(ws));
1269                 ws.ws_row = vc->vc_rows;
1270                 ws.ws_col = vc->vc_cols;
1271                 ws.ws_ypixel = vc->vc_scan_lines;
1272                 tty_do_resize(tty, &ws);
1273         }
1274
1275         if (con_is_visible(vc))
1276                 update_screen(vc);
1277         vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1278         notify_update(vc);
1279         return err;
1280 }
1281
1282 /**
1283  *      vc_resize               -       resize a VT
1284  *      @vc: virtual console
1285  *      @cols: columns
1286  *      @rows: rows
1287  *
1288  *      Resize a virtual console as seen from the console end of things. We
1289  *      use the common vc_do_resize methods to update the structures. The
1290  *      caller must hold the console sem to protect console internals and
1291  *      vc->port.tty
1292  */
1293
1294 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1295 {
1296         return vc_do_resize(vc->port.tty, vc, cols, rows);
1297 }
1298
1299 /**
1300  *      vt_resize               -       resize a VT
1301  *      @tty: tty to resize
1302  *      @ws: winsize attributes
1303  *
1304  *      Resize a virtual terminal. This is called by the tty layer as we
1305  *      register our own handler for resizing. The mutual helper does all
1306  *      the actual work.
1307  *
1308  *      Takes the console sem and the called methods then take the tty
1309  *      termios_rwsem and the tty ctrl_lock in that order.
1310  */
1311 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1312 {
1313         struct vc_data *vc = tty->driver_data;
1314         int ret;
1315
1316         console_lock();
1317         ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1318         console_unlock();
1319         return ret;
1320 }
1321
1322 struct vc_data *vc_deallocate(unsigned int currcons)
1323 {
1324         struct vc_data *vc = NULL;
1325
1326         WARN_CONSOLE_UNLOCKED();
1327
1328         if (vc_cons_allocated(currcons)) {
1329                 struct vt_notifier_param param;
1330
1331                 param.vc = vc = vc_cons[currcons].d;
1332                 atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1333                 vcs_remove_sysfs(currcons);
1334                 vc->vc_sw->con_deinit(vc);
1335                 put_pid(vc->vt_pid);
1336                 module_put(vc->vc_sw->owner);
1337                 vc_uniscr_set(vc, NULL);
1338                 kfree(vc->vc_screenbuf);
1339                 vc_cons[currcons].d = NULL;
1340         }
1341         return vc;
1342 }
1343
1344 /*
1345  *      VT102 emulator
1346  */
1347
1348 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1349
1350 #define set_kbd(vc, x)  vt_set_kbd_mode_bit((vc)->vc_num, (x))
1351 #define clr_kbd(vc, x)  vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1352 #define is_kbd(vc, x)   vt_get_kbd_mode_bit((vc)->vc_num, (x))
1353
1354 #define decarm          VC_REPEAT
1355 #define decckm          VC_CKMODE
1356 #define kbdapplic       VC_APPLIC
1357 #define lnm             VC_CRLF
1358
1359 /*
1360  * this is what the terminal answers to a ESC-Z or csi0c query.
1361  */
1362 #define VT100ID "\033[?1;2c"
1363 #define VT102ID "\033[?6c"
1364
1365 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1366                                        8,12,10,14, 9,13,11,15 };
1367
1368 /* the default colour table, for VGA+ colour systems */
1369 unsigned char default_red[] = {
1370         0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1371         0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1372 };
1373 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1374
1375 unsigned char default_grn[] = {
1376         0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1377         0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1378 };
1379 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1380
1381 unsigned char default_blu[] = {
1382         0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1383         0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1384 };
1385 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1386
1387 /*
1388  * gotoxy() must verify all boundaries, because the arguments
1389  * might also be negative. If the given position is out of
1390  * bounds, the cursor is placed at the nearest margin.
1391  */
1392 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1393 {
1394         int min_y, max_y;
1395
1396         if (new_x < 0)
1397                 vc->vc_x = 0;
1398         else {
1399                 if (new_x >= vc->vc_cols)
1400                         vc->vc_x = vc->vc_cols - 1;
1401                 else
1402                         vc->vc_x = new_x;
1403         }
1404
1405         if (vc->vc_decom) {
1406                 min_y = vc->vc_top;
1407                 max_y = vc->vc_bottom;
1408         } else {
1409                 min_y = 0;
1410                 max_y = vc->vc_rows;
1411         }
1412         if (new_y < min_y)
1413                 vc->vc_y = min_y;
1414         else if (new_y >= max_y)
1415                 vc->vc_y = max_y - 1;
1416         else
1417                 vc->vc_y = new_y;
1418         vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
1419         vc->vc_need_wrap = 0;
1420 }
1421
1422 /* for absolute user moves, when decom is set */
1423 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1424 {
1425         gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1426 }
1427
1428 void scrollback(struct vc_data *vc)
1429 {
1430         scrolldelta(-(vc->vc_rows / 2));
1431 }
1432
1433 void scrollfront(struct vc_data *vc, int lines)
1434 {
1435         if (!lines)
1436                 lines = vc->vc_rows / 2;
1437         scrolldelta(lines);
1438 }
1439
1440 static void lf(struct vc_data *vc)
1441 {
1442         /* don't scroll if above bottom of scrolling region, or
1443          * if below scrolling region
1444          */
1445         if (vc->vc_y + 1 == vc->vc_bottom)
1446                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1447         else if (vc->vc_y < vc->vc_rows - 1) {
1448                 vc->vc_y++;
1449                 vc->vc_pos += vc->vc_size_row;
1450         }
1451         vc->vc_need_wrap = 0;
1452         notify_write(vc, '\n');
1453 }
1454
1455 static void ri(struct vc_data *vc)
1456 {
1457         /* don't scroll if below top of scrolling region, or
1458          * if above scrolling region
1459          */
1460         if (vc->vc_y == vc->vc_top)
1461                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1462         else if (vc->vc_y > 0) {
1463                 vc->vc_y--;
1464                 vc->vc_pos -= vc->vc_size_row;
1465         }
1466         vc->vc_need_wrap = 0;
1467 }
1468
1469 static inline void cr(struct vc_data *vc)
1470 {
1471         vc->vc_pos -= vc->vc_x << 1;
1472         vc->vc_need_wrap = vc->vc_x = 0;
1473         notify_write(vc, '\r');
1474 }
1475
1476 static inline void bs(struct vc_data *vc)
1477 {
1478         if (vc->vc_x) {
1479                 vc->vc_pos -= 2;
1480                 vc->vc_x--;
1481                 vc->vc_need_wrap = 0;
1482                 notify_write(vc, '\b');
1483         }
1484 }
1485
1486 static inline void del(struct vc_data *vc)
1487 {
1488         /* ignored */
1489 }
1490
1491 static void csi_J(struct vc_data *vc, int vpar)
1492 {
1493         unsigned int count;
1494         unsigned short * start;
1495
1496         switch (vpar) {
1497                 case 0: /* erase from cursor to end of display */
1498                         vc_uniscr_clear_line(vc, vc->vc_x,
1499                                              vc->vc_cols - vc->vc_x);
1500                         vc_uniscr_clear_lines(vc, vc->vc_y + 1,
1501                                               vc->vc_rows - vc->vc_y - 1);
1502                         count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1503                         start = (unsigned short *)vc->vc_pos;
1504                         break;
1505                 case 1: /* erase from start to cursor */
1506                         vc_uniscr_clear_line(vc, 0, vc->vc_x + 1);
1507                         vc_uniscr_clear_lines(vc, 0, vc->vc_y);
1508                         count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1509                         start = (unsigned short *)vc->vc_origin;
1510                         break;
1511                 case 3: /* include scrollback */
1512                         flush_scrollback(vc);
1513                         /* fallthrough */
1514                 case 2: /* erase whole display */
1515                         vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1516                         count = vc->vc_cols * vc->vc_rows;
1517                         start = (unsigned short *)vc->vc_origin;
1518                         break;
1519                 default:
1520                         return;
1521         }
1522         scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1523         update_region(vc, (unsigned long) start, count);
1524         vc->vc_need_wrap = 0;
1525 }
1526
1527 static void csi_K(struct vc_data *vc, int vpar)
1528 {
1529         unsigned int count;
1530         unsigned short *start = (unsigned short *)vc->vc_pos;
1531         int offset;
1532
1533         switch (vpar) {
1534                 case 0: /* erase from cursor to end of line */
1535                         offset = 0;
1536                         count = vc->vc_cols - vc->vc_x;
1537                         break;
1538                 case 1: /* erase from start of line to cursor */
1539                         offset = -vc->vc_x;
1540                         count = vc->vc_x + 1;
1541                         break;
1542                 case 2: /* erase whole line */
1543                         offset = -vc->vc_x;
1544                         count = vc->vc_cols;
1545                         break;
1546                 default:
1547                         return;
1548         }
1549         vc_uniscr_clear_line(vc, vc->vc_x + offset, count);
1550         scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1551         vc->vc_need_wrap = 0;
1552         if (con_should_update(vc))
1553                 do_update_region(vc, (unsigned long)(start + offset), count);
1554 }
1555
1556 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1557 {                                         /* not vt100? */
1558         int count;
1559
1560         if (!vpar)
1561                 vpar++;
1562         count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
1563
1564         vc_uniscr_clear_line(vc, vc->vc_x, count);
1565         scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1566         if (con_should_update(vc))
1567                 vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
1568         vc->vc_need_wrap = 0;
1569 }
1570
1571 static void default_attr(struct vc_data *vc)
1572 {
1573         vc->vc_intensity = 1;
1574         vc->vc_italic = 0;
1575         vc->vc_underline = 0;
1576         vc->vc_reverse = 0;
1577         vc->vc_blink = 0;
1578         vc->vc_color = vc->vc_def_color;
1579 }
1580
1581 struct rgb { u8 r; u8 g; u8 b; };
1582
1583 static void rgb_from_256(int i, struct rgb *c)
1584 {
1585         if (i < 8) {            /* Standard colours. */
1586                 c->r = i&1 ? 0xaa : 0x00;
1587                 c->g = i&2 ? 0xaa : 0x00;
1588                 c->b = i&4 ? 0xaa : 0x00;
1589         } else if (i < 16) {
1590                 c->r = i&1 ? 0xff : 0x55;
1591                 c->g = i&2 ? 0xff : 0x55;
1592                 c->b = i&4 ? 0xff : 0x55;
1593         } else if (i < 232) {   /* 6x6x6 colour cube. */
1594                 c->r = (i - 16) / 36 * 85 / 2;
1595                 c->g = (i - 16) / 6 % 6 * 85 / 2;
1596                 c->b = (i - 16) % 6 * 85 / 2;
1597         } else                  /* Grayscale ramp. */
1598                 c->r = c->g = c->b = i * 10 - 2312;
1599 }
1600
1601 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1602 {
1603         u8 hue = 0, max = max3(c->r, c->g, c->b);
1604
1605         if (c->r > max / 2)
1606                 hue |= 4;
1607         if (c->g > max / 2)
1608                 hue |= 2;
1609         if (c->b > max / 2)
1610                 hue |= 1;
1611
1612         if (hue == 7 && max <= 0x55) {
1613                 hue = 0;
1614                 vc->vc_intensity = 2;
1615         } else if (max > 0xaa)
1616                 vc->vc_intensity = 2;
1617         else
1618                 vc->vc_intensity = 1;
1619
1620         vc->vc_color = (vc->vc_color & 0xf0) | hue;
1621 }
1622
1623 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1624 {
1625         /* For backgrounds, err on the dark side. */
1626         vc->vc_color = (vc->vc_color & 0x0f)
1627                 | (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1628 }
1629
1630 /*
1631  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1632  * and thus need to be detected and ignored by hand. That standard also
1633  * wants : rather than ; as separators but sequences containing : are currently
1634  * completely ignored by the parser.
1635  *
1636  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1637  * supporting them.
1638  */
1639 static int vc_t416_color(struct vc_data *vc, int i,
1640                 void(*set_color)(struct vc_data *vc, const struct rgb *c))
1641 {
1642         struct rgb c;
1643
1644         i++;
1645         if (i > vc->vc_npar)
1646                 return i;
1647
1648         if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1649                 /* 256 colours */
1650                 i++;
1651                 rgb_from_256(vc->vc_par[i], &c);
1652         } else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1653                 /* 24 bit */
1654                 c.r = vc->vc_par[i + 1];
1655                 c.g = vc->vc_par[i + 2];
1656                 c.b = vc->vc_par[i + 3];
1657                 i += 3;
1658         } else
1659                 return i;
1660
1661         set_color(vc, &c);
1662
1663         return i;
1664 }
1665
1666 /* console_lock is held */
1667 static void csi_m(struct vc_data *vc)
1668 {
1669         int i;
1670
1671         for (i = 0; i <= vc->vc_npar; i++)
1672                 switch (vc->vc_par[i]) {
1673                 case 0: /* all attributes off */
1674                         default_attr(vc);
1675                         break;
1676                 case 1:
1677                         vc->vc_intensity = 2;
1678                         break;
1679                 case 2:
1680                         vc->vc_intensity = 0;
1681                         break;
1682                 case 3:
1683                         vc->vc_italic = 1;
1684                         break;
1685                 case 21:
1686                         /*
1687                          * No console drivers support double underline, so
1688                          * convert it to a single underline.
1689                          */
1690                 case 4:
1691                         vc->vc_underline = 1;
1692                         break;
1693                 case 5:
1694                         vc->vc_blink = 1;
1695                         break;
1696                 case 7:
1697                         vc->vc_reverse = 1;
1698                         break;
1699                 case 10: /* ANSI X3.64-1979 (SCO-ish?)
1700                           * Select primary font, don't display control chars if
1701                           * defined, don't set bit 8 on output.
1702                           */
1703                         vc->vc_translate = set_translate(vc->vc_charset == 0
1704                                         ? vc->vc_G0_charset
1705                                         : vc->vc_G1_charset, vc);
1706                         vc->vc_disp_ctrl = 0;
1707                         vc->vc_toggle_meta = 0;
1708                         break;
1709                 case 11: /* ANSI X3.64-1979 (SCO-ish?)
1710                           * Select first alternate font, lets chars < 32 be
1711                           * displayed as ROM chars.
1712                           */
1713                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1714                         vc->vc_disp_ctrl = 1;
1715                         vc->vc_toggle_meta = 0;
1716                         break;
1717                 case 12: /* ANSI X3.64-1979 (SCO-ish?)
1718                           * Select second alternate font, toggle high bit
1719                           * before displaying as ROM char.
1720                           */
1721                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1722                         vc->vc_disp_ctrl = 1;
1723                         vc->vc_toggle_meta = 1;
1724                         break;
1725                 case 22:
1726                         vc->vc_intensity = 1;
1727                         break;
1728                 case 23:
1729                         vc->vc_italic = 0;
1730                         break;
1731                 case 24:
1732                         vc->vc_underline = 0;
1733                         break;
1734                 case 25:
1735                         vc->vc_blink = 0;
1736                         break;
1737                 case 27:
1738                         vc->vc_reverse = 0;
1739                         break;
1740                 case 38:
1741                         i = vc_t416_color(vc, i, rgb_foreground);
1742                         break;
1743                 case 48:
1744                         i = vc_t416_color(vc, i, rgb_background);
1745                         break;
1746                 case 39:
1747                         vc->vc_color = (vc->vc_def_color & 0x0f) |
1748                                 (vc->vc_color & 0xf0);
1749                         break;
1750                 case 49:
1751                         vc->vc_color = (vc->vc_def_color & 0xf0) |
1752                                 (vc->vc_color & 0x0f);
1753                         break;
1754                 default:
1755                         if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1756                                 if (vc->vc_par[i] < 100)
1757                                         vc->vc_intensity = 2;
1758                                 vc->vc_par[i] -= 60;
1759                         }
1760                         if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1761                                 vc->vc_color = color_table[vc->vc_par[i] - 30]
1762                                         | (vc->vc_color & 0xf0);
1763                         else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1764                                 vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1765                                         | (vc->vc_color & 0x0f);
1766                         break;
1767                 }
1768         update_attr(vc);
1769 }
1770
1771 static void respond_string(const char *p, struct tty_port *port)
1772 {
1773         while (*p) {
1774                 tty_insert_flip_char(port, *p, 0);
1775                 p++;
1776         }
1777         tty_schedule_flip(port);
1778 }
1779
1780 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1781 {
1782         char buf[40];
1783
1784         sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1785         respond_string(buf, tty->port);
1786 }
1787
1788 static inline void status_report(struct tty_struct *tty)
1789 {
1790         respond_string("\033[0n", tty->port);   /* Terminal ok */
1791 }
1792
1793 static inline void respond_ID(struct tty_struct *tty)
1794 {
1795         respond_string(VT102ID, tty->port);
1796 }
1797
1798 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1799 {
1800         char buf[8];
1801
1802         sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1803                 (char)('!' + mry));
1804         respond_string(buf, tty->port);
1805 }
1806
1807 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1808 int mouse_reporting(void)
1809 {
1810         return vc_cons[fg_console].d->vc_report_mouse;
1811 }
1812
1813 /* console_lock is held */
1814 static void set_mode(struct vc_data *vc, int on_off)
1815 {
1816         int i;
1817
1818         for (i = 0; i <= vc->vc_npar; i++)
1819                 if (vc->vc_priv == EPdec) {
1820                         switch(vc->vc_par[i]) { /* DEC private modes set/reset */
1821                         case 1:                 /* Cursor keys send ^[Ox/^[[x */
1822                                 if (on_off)
1823                                         set_kbd(vc, decckm);
1824                                 else
1825                                         clr_kbd(vc, decckm);
1826                                 break;
1827                         case 3: /* 80/132 mode switch unimplemented */
1828 #if 0
1829                                 vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1830                                 /* this alone does not suffice; some user mode
1831                                    utility has to change the hardware regs */
1832 #endif
1833                                 break;
1834                         case 5:                 /* Inverted screen on/off */
1835                                 if (vc->vc_decscnm != on_off) {
1836                                         vc->vc_decscnm = on_off;
1837                                         invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1838                                         update_attr(vc);
1839                                 }
1840                                 break;
1841                         case 6:                 /* Origin relative/absolute */
1842                                 vc->vc_decom = on_off;
1843                                 gotoxay(vc, 0, 0);
1844                                 break;
1845                         case 7:                 /* Autowrap on/off */
1846                                 vc->vc_decawm = on_off;
1847                                 break;
1848                         case 8:                 /* Autorepeat on/off */
1849                                 if (on_off)
1850                                         set_kbd(vc, decarm);
1851                                 else
1852                                         clr_kbd(vc, decarm);
1853                                 break;
1854                         case 9:
1855                                 vc->vc_report_mouse = on_off ? 1 : 0;
1856                                 break;
1857                         case 25:                /* Cursor on/off */
1858                                 vc->vc_deccm = on_off;
1859                                 break;
1860                         case 1000:
1861                                 vc->vc_report_mouse = on_off ? 2 : 0;
1862                                 break;
1863                         }
1864                 } else {
1865                         switch(vc->vc_par[i]) { /* ANSI modes set/reset */
1866                         case 3:                 /* Monitor (display ctrls) */
1867                                 vc->vc_disp_ctrl = on_off;
1868                                 break;
1869                         case 4:                 /* Insert Mode on/off */
1870                                 vc->vc_decim = on_off;
1871                                 break;
1872                         case 20:                /* Lf, Enter == CrLf/Lf */
1873                                 if (on_off)
1874                                         set_kbd(vc, lnm);
1875                                 else
1876                                         clr_kbd(vc, lnm);
1877                                 break;
1878                         }
1879                 }
1880 }
1881
1882 /* console_lock is held */
1883 static void setterm_command(struct vc_data *vc)
1884 {
1885         switch(vc->vc_par[0]) {
1886                 case 1: /* set color for underline mode */
1887                         if (vc->vc_can_do_color &&
1888                                         vc->vc_par[1] < 16) {
1889                                 vc->vc_ulcolor = color_table[vc->vc_par[1]];
1890                                 if (vc->vc_underline)
1891                                         update_attr(vc);
1892                         }
1893                         break;
1894                 case 2: /* set color for half intensity mode */
1895                         if (vc->vc_can_do_color &&
1896                                         vc->vc_par[1] < 16) {
1897                                 vc->vc_halfcolor = color_table[vc->vc_par[1]];
1898                                 if (vc->vc_intensity == 0)
1899                                         update_attr(vc);
1900                         }
1901                         break;
1902                 case 8: /* store colors as defaults */
1903                         vc->vc_def_color = vc->vc_attr;
1904                         if (vc->vc_hi_font_mask == 0x100)
1905                                 vc->vc_def_color >>= 1;
1906                         default_attr(vc);
1907                         update_attr(vc);
1908                         break;
1909                 case 9: /* set blanking interval */
1910                         blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1911                         poke_blanked_console();
1912                         break;
1913                 case 10: /* set bell frequency in Hz */
1914                         if (vc->vc_npar >= 1)
1915                                 vc->vc_bell_pitch = vc->vc_par[1];
1916                         else
1917                                 vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1918                         break;
1919                 case 11: /* set bell duration in msec */
1920                         if (vc->vc_npar >= 1)
1921                                 vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1922                                         msecs_to_jiffies(vc->vc_par[1]) : 0;
1923                         else
1924                                 vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1925                         break;
1926                 case 12: /* bring specified console to the front */
1927                         if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1928                                 set_console(vc->vc_par[1] - 1);
1929                         break;
1930                 case 13: /* unblank the screen */
1931                         poke_blanked_console();
1932                         break;
1933                 case 14: /* set vesa powerdown interval */
1934                         vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1935                         break;
1936                 case 15: /* activate the previous console */
1937                         set_console(last_console);
1938                         break;
1939                 case 16: /* set cursor blink duration in msec */
1940                         if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1941                                         vc->vc_par[1] <= USHRT_MAX)
1942                                 vc->vc_cur_blink_ms = vc->vc_par[1];
1943                         else
1944                                 vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1945                         break;
1946         }
1947 }
1948
1949 /* console_lock is held */
1950 static void csi_at(struct vc_data *vc, unsigned int nr)
1951 {
1952         if (nr > vc->vc_cols - vc->vc_x)
1953                 nr = vc->vc_cols - vc->vc_x;
1954         else if (!nr)
1955                 nr = 1;
1956         insert_char(vc, nr);
1957 }
1958
1959 /* console_lock is held */
1960 static void csi_L(struct vc_data *vc, unsigned int nr)
1961 {
1962         if (nr > vc->vc_rows - vc->vc_y)
1963                 nr = vc->vc_rows - vc->vc_y;
1964         else if (!nr)
1965                 nr = 1;
1966         con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_DOWN, nr);
1967         vc->vc_need_wrap = 0;
1968 }
1969
1970 /* console_lock is held */
1971 static void csi_P(struct vc_data *vc, unsigned int nr)
1972 {
1973         if (nr > vc->vc_cols - vc->vc_x)
1974                 nr = vc->vc_cols - vc->vc_x;
1975         else if (!nr)
1976                 nr = 1;
1977         delete_char(vc, nr);
1978 }
1979
1980 /* console_lock is held */
1981 static void csi_M(struct vc_data *vc, unsigned int nr)
1982 {
1983         if (nr > vc->vc_rows - vc->vc_y)
1984                 nr = vc->vc_rows - vc->vc_y;
1985         else if (!nr)
1986                 nr=1;
1987         con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_UP, nr);
1988         vc->vc_need_wrap = 0;
1989 }
1990
1991 /* console_lock is held (except via vc_init->reset_terminal */
1992 static void save_cur(struct vc_data *vc)
1993 {
1994         vc->vc_saved_x          = vc->vc_x;
1995         vc->vc_saved_y          = vc->vc_y;
1996         vc->vc_s_intensity      = vc->vc_intensity;
1997         vc->vc_s_italic         = vc->vc_italic;
1998         vc->vc_s_underline      = vc->vc_underline;
1999         vc->vc_s_blink          = vc->vc_blink;
2000         vc->vc_s_reverse        = vc->vc_reverse;
2001         vc->vc_s_charset        = vc->vc_charset;
2002         vc->vc_s_color          = vc->vc_color;
2003         vc->vc_saved_G0         = vc->vc_G0_charset;
2004         vc->vc_saved_G1         = vc->vc_G1_charset;
2005 }
2006
2007 /* console_lock is held */
2008 static void restore_cur(struct vc_data *vc)
2009 {
2010         gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
2011         vc->vc_intensity        = vc->vc_s_intensity;
2012         vc->vc_italic           = vc->vc_s_italic;
2013         vc->vc_underline        = vc->vc_s_underline;
2014         vc->vc_blink            = vc->vc_s_blink;
2015         vc->vc_reverse          = vc->vc_s_reverse;
2016         vc->vc_charset          = vc->vc_s_charset;
2017         vc->vc_color            = vc->vc_s_color;
2018         vc->vc_G0_charset       = vc->vc_saved_G0;
2019         vc->vc_G1_charset       = vc->vc_saved_G1;
2020         vc->vc_translate        = set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
2021         update_attr(vc);
2022         vc->vc_need_wrap = 0;
2023 }
2024
2025 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2026         EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2027         ESpalette, ESosc };
2028
2029 /* console_lock is held (except via vc_init()) */
2030 static void reset_terminal(struct vc_data *vc, int do_clear)
2031 {
2032         vc->vc_top              = 0;
2033         vc->vc_bottom           = vc->vc_rows;
2034         vc->vc_state            = ESnormal;
2035         vc->vc_priv             = EPecma;
2036         vc->vc_translate        = set_translate(LAT1_MAP, vc);
2037         vc->vc_G0_charset       = LAT1_MAP;
2038         vc->vc_G1_charset       = GRAF_MAP;
2039         vc->vc_charset          = 0;
2040         vc->vc_need_wrap        = 0;
2041         vc->vc_report_mouse     = 0;
2042         vc->vc_utf              = default_utf8;
2043         vc->vc_utf_count        = 0;
2044
2045         vc->vc_disp_ctrl        = 0;
2046         vc->vc_toggle_meta      = 0;
2047
2048         vc->vc_decscnm          = 0;
2049         vc->vc_decom            = 0;
2050         vc->vc_decawm           = 1;
2051         vc->vc_deccm            = global_cursor_default;
2052         vc->vc_decim            = 0;
2053
2054         vt_reset_keyboard(vc->vc_num);
2055
2056         vc->vc_cursor_type = cur_default;
2057         vc->vc_complement_mask = vc->vc_s_complement_mask;
2058
2059         default_attr(vc);
2060         update_attr(vc);
2061
2062         vc->vc_tab_stop[0]      =
2063         vc->vc_tab_stop[1]      =
2064         vc->vc_tab_stop[2]      =
2065         vc->vc_tab_stop[3]      =
2066         vc->vc_tab_stop[4]      =
2067         vc->vc_tab_stop[5]      =
2068         vc->vc_tab_stop[6]      =
2069         vc->vc_tab_stop[7]      = 0x01010101;
2070
2071         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2072         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2073         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2074
2075         gotoxy(vc, 0, 0);
2076         save_cur(vc);
2077         if (do_clear)
2078             csi_J(vc, 2);
2079 }
2080
2081 /* console_lock is held */
2082 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2083 {
2084         /*
2085          *  Control characters can be used in the _middle_
2086          *  of an escape sequence.
2087          */
2088         if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
2089                 return;
2090         switch (c) {
2091         case 0:
2092                 return;
2093         case 7:
2094                 if (vc->vc_state == ESosc)
2095                         vc->vc_state = ESnormal;
2096                 else if (vc->vc_bell_duration)
2097                         kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2098                 return;
2099         case 8:
2100                 bs(vc);
2101                 return;
2102         case 9:
2103                 vc->vc_pos -= (vc->vc_x << 1);
2104                 while (vc->vc_x < vc->vc_cols - 1) {
2105                         vc->vc_x++;
2106                         if (vc->vc_tab_stop[7 & (vc->vc_x >> 5)] & (1 << (vc->vc_x & 31)))
2107                                 break;
2108                 }
2109                 vc->vc_pos += (vc->vc_x << 1);
2110                 notify_write(vc, '\t');
2111                 return;
2112         case 10: case 11: case 12:
2113                 lf(vc);
2114                 if (!is_kbd(vc, lnm))
2115                         return;
2116                 /* fall through */
2117         case 13:
2118                 cr(vc);
2119                 return;
2120         case 14:
2121                 vc->vc_charset = 1;
2122                 vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2123                 vc->vc_disp_ctrl = 1;
2124                 return;
2125         case 15:
2126                 vc->vc_charset = 0;
2127                 vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2128                 vc->vc_disp_ctrl = 0;
2129                 return;
2130         case 24: case 26:
2131                 vc->vc_state = ESnormal;
2132                 return;
2133         case 27:
2134                 vc->vc_state = ESesc;
2135                 return;
2136         case 127:
2137                 del(vc);
2138                 return;
2139         case 128+27:
2140                 vc->vc_state = ESsquare;
2141                 return;
2142         }
2143         switch(vc->vc_state) {
2144         case ESesc:
2145                 vc->vc_state = ESnormal;
2146                 switch (c) {
2147                 case '[':
2148                         vc->vc_state = ESsquare;
2149                         return;
2150                 case ']':
2151                         vc->vc_state = ESnonstd;
2152                         return;
2153                 case '%':
2154                         vc->vc_state = ESpercent;
2155                         return;
2156                 case 'E':
2157                         cr(vc);
2158                         lf(vc);
2159                         return;
2160                 case 'M':
2161                         ri(vc);
2162                         return;
2163                 case 'D':
2164                         lf(vc);
2165                         return;
2166                 case 'H':
2167                         vc->vc_tab_stop[7 & (vc->vc_x >> 5)] |= (1 << (vc->vc_x & 31));
2168                         return;
2169                 case 'Z':
2170                         respond_ID(tty);
2171                         return;
2172                 case '7':
2173                         save_cur(vc);
2174                         return;
2175                 case '8':
2176                         restore_cur(vc);
2177                         return;
2178                 case '(':
2179                         vc->vc_state = ESsetG0;
2180                         return;
2181                 case ')':
2182                         vc->vc_state = ESsetG1;
2183                         return;
2184                 case '#':
2185                         vc->vc_state = EShash;
2186                         return;
2187                 case 'c':
2188                         reset_terminal(vc, 1);
2189                         return;
2190                 case '>':  /* Numeric keypad */
2191                         clr_kbd(vc, kbdapplic);
2192                         return;
2193                 case '=':  /* Appl. keypad */
2194                         set_kbd(vc, kbdapplic);
2195                         return;
2196                 }
2197                 return;
2198         case ESnonstd:
2199                 if (c=='P') {   /* palette escape sequence */
2200                         for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2201                                 vc->vc_par[vc->vc_npar] = 0;
2202                         vc->vc_npar = 0;
2203                         vc->vc_state = ESpalette;
2204                         return;
2205                 } else if (c=='R') {   /* reset palette */
2206                         reset_palette(vc);
2207                         vc->vc_state = ESnormal;
2208                 } else if (c>='0' && c<='9')
2209                         vc->vc_state = ESosc;
2210                 else
2211                         vc->vc_state = ESnormal;
2212                 return;
2213         case ESpalette:
2214                 if (isxdigit(c)) {
2215                         vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2216                         if (vc->vc_npar == 7) {
2217                                 int i = vc->vc_par[0] * 3, j = 1;
2218                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2219                                 vc->vc_palette[i++] += vc->vc_par[j++];
2220                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2221                                 vc->vc_palette[i++] += vc->vc_par[j++];
2222                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2223                                 vc->vc_palette[i] += vc->vc_par[j];
2224                                 set_palette(vc);
2225                                 vc->vc_state = ESnormal;
2226                         }
2227                 } else
2228                         vc->vc_state = ESnormal;
2229                 return;
2230         case ESsquare:
2231                 for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2232                         vc->vc_par[vc->vc_npar] = 0;
2233                 vc->vc_npar = 0;
2234                 vc->vc_state = ESgetpars;
2235                 if (c == '[') { /* Function key */
2236                         vc->vc_state=ESfunckey;
2237                         return;
2238                 }
2239                 switch (c) {
2240                 case '?':
2241                         vc->vc_priv = EPdec;
2242                         return;
2243                 case '>':
2244                         vc->vc_priv = EPgt;
2245                         return;
2246                 case '=':
2247                         vc->vc_priv = EPeq;
2248                         return;
2249                 case '<':
2250                         vc->vc_priv = EPlt;
2251                         return;
2252                 }
2253                 vc->vc_priv = EPecma;
2254                 /* fall through */
2255         case ESgetpars:
2256                 if (c == ';' && vc->vc_npar < NPAR - 1) {
2257                         vc->vc_npar++;
2258                         return;
2259                 } else if (c>='0' && c<='9') {
2260                         vc->vc_par[vc->vc_npar] *= 10;
2261                         vc->vc_par[vc->vc_npar] += c - '0';
2262                         return;
2263                 }
2264                 if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2265                         vc->vc_state = EScsiignore;
2266                         return;
2267                 }
2268                 vc->vc_state = ESnormal;
2269                 switch(c) {
2270                 case 'h':
2271                         if (vc->vc_priv <= EPdec)
2272                                 set_mode(vc, 1);
2273                         return;
2274                 case 'l':
2275                         if (vc->vc_priv <= EPdec)
2276                                 set_mode(vc, 0);
2277                         return;
2278                 case 'c':
2279                         if (vc->vc_priv == EPdec) {
2280                                 if (vc->vc_par[0])
2281                                         vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
2282                                 else
2283                                         vc->vc_cursor_type = cur_default;
2284                                 return;
2285                         }
2286                         break;
2287                 case 'm':
2288                         if (vc->vc_priv == EPdec) {
2289                                 clear_selection();
2290                                 if (vc->vc_par[0])
2291                                         vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2292                                 else
2293                                         vc->vc_complement_mask = vc->vc_s_complement_mask;
2294                                 return;
2295                         }
2296                         break;
2297                 case 'n':
2298                         if (vc->vc_priv == EPecma) {
2299                                 if (vc->vc_par[0] == 5)
2300                                         status_report(tty);
2301                                 else if (vc->vc_par[0] == 6)
2302                                         cursor_report(vc, tty);
2303                         }
2304                         return;
2305                 }
2306                 if (vc->vc_priv != EPecma) {
2307                         vc->vc_priv = EPecma;
2308                         return;
2309                 }
2310                 switch(c) {
2311                 case 'G': case '`':
2312                         if (vc->vc_par[0])
2313                                 vc->vc_par[0]--;
2314                         gotoxy(vc, vc->vc_par[0], vc->vc_y);
2315                         return;
2316                 case 'A':
2317                         if (!vc->vc_par[0])
2318                                 vc->vc_par[0]++;
2319                         gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
2320                         return;
2321                 case 'B': case 'e':
2322                         if (!vc->vc_par[0])
2323                                 vc->vc_par[0]++;
2324                         gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
2325                         return;
2326                 case 'C': case 'a':
2327                         if (!vc->vc_par[0])
2328                                 vc->vc_par[0]++;
2329                         gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
2330                         return;
2331                 case 'D':
2332                         if (!vc->vc_par[0])
2333                                 vc->vc_par[0]++;
2334                         gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
2335                         return;
2336                 case 'E':
2337                         if (!vc->vc_par[0])
2338                                 vc->vc_par[0]++;
2339                         gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
2340                         return;
2341                 case 'F':
2342                         if (!vc->vc_par[0])
2343                                 vc->vc_par[0]++;
2344                         gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
2345                         return;
2346                 case 'd':
2347                         if (vc->vc_par[0])
2348                                 vc->vc_par[0]--;
2349                         gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
2350                         return;
2351                 case 'H': case 'f':
2352                         if (vc->vc_par[0])
2353                                 vc->vc_par[0]--;
2354                         if (vc->vc_par[1])
2355                                 vc->vc_par[1]--;
2356                         gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2357                         return;
2358                 case 'J':
2359                         csi_J(vc, vc->vc_par[0]);
2360                         return;
2361                 case 'K':
2362                         csi_K(vc, vc->vc_par[0]);
2363                         return;
2364                 case 'L':
2365                         csi_L(vc, vc->vc_par[0]);
2366                         return;
2367                 case 'M':
2368                         csi_M(vc, vc->vc_par[0]);
2369                         return;
2370                 case 'P':
2371                         csi_P(vc, vc->vc_par[0]);
2372                         return;
2373                 case 'c':
2374                         if (!vc->vc_par[0])
2375                                 respond_ID(tty);
2376                         return;
2377                 case 'g':
2378                         if (!vc->vc_par[0])
2379                                 vc->vc_tab_stop[7 & (vc->vc_x >> 5)] &= ~(1 << (vc->vc_x & 31));
2380                         else if (vc->vc_par[0] == 3) {
2381                                 vc->vc_tab_stop[0] =
2382                                         vc->vc_tab_stop[1] =
2383                                         vc->vc_tab_stop[2] =
2384                                         vc->vc_tab_stop[3] =
2385                                         vc->vc_tab_stop[4] =
2386                                         vc->vc_tab_stop[5] =
2387                                         vc->vc_tab_stop[6] =
2388                                         vc->vc_tab_stop[7] = 0;
2389                         }
2390                         return;
2391                 case 'm':
2392                         csi_m(vc);
2393                         return;
2394                 case 'q': /* DECLL - but only 3 leds */
2395                         /* map 0,1,2,3 to 0,1,2,4 */
2396                         if (vc->vc_par[0] < 4)
2397                                 vt_set_led_state(vc->vc_num,
2398                                             (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2399                         return;
2400                 case 'r':
2401                         if (!vc->vc_par[0])
2402                                 vc->vc_par[0]++;
2403                         if (!vc->vc_par[1])
2404                                 vc->vc_par[1] = vc->vc_rows;
2405                         /* Minimum allowed region is 2 lines */
2406                         if (vc->vc_par[0] < vc->vc_par[1] &&
2407                             vc->vc_par[1] <= vc->vc_rows) {
2408                                 vc->vc_top = vc->vc_par[0] - 1;
2409                                 vc->vc_bottom = vc->vc_par[1];
2410                                 gotoxay(vc, 0, 0);
2411                         }
2412                         return;
2413                 case 's':
2414                         save_cur(vc);
2415                         return;
2416                 case 'u':
2417                         restore_cur(vc);
2418                         return;
2419                 case 'X':
2420                         csi_X(vc, vc->vc_par[0]);
2421                         return;
2422                 case '@':
2423                         csi_at(vc, vc->vc_par[0]);
2424                         return;
2425                 case ']': /* setterm functions */
2426                         setterm_command(vc);
2427                         return;
2428                 }
2429                 return;
2430         case EScsiignore:
2431                 if (c >= 20 && c <= 0x3f)
2432                         return;
2433                 vc->vc_state = ESnormal;
2434                 return;
2435         case ESpercent:
2436                 vc->vc_state = ESnormal;
2437                 switch (c) {
2438                 case '@':  /* defined in ISO 2022 */
2439                         vc->vc_utf = 0;
2440                         return;
2441                 case 'G':  /* prelim official escape code */
2442                 case '8':  /* retained for compatibility */
2443                         vc->vc_utf = 1;
2444                         return;
2445                 }
2446                 return;
2447         case ESfunckey:
2448                 vc->vc_state = ESnormal;
2449                 return;
2450         case EShash:
2451                 vc->vc_state = ESnormal;
2452                 if (c == '8') {
2453                         /* DEC screen alignment test. kludge :-) */
2454                         vc->vc_video_erase_char =
2455                                 (vc->vc_video_erase_char & 0xff00) | 'E';
2456                         csi_J(vc, 2);
2457                         vc->vc_video_erase_char =
2458                                 (vc->vc_video_erase_char & 0xff00) | ' ';
2459                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2460                 }
2461                 return;
2462         case ESsetG0:
2463                 if (c == '0')
2464                         vc->vc_G0_charset = GRAF_MAP;
2465                 else if (c == 'B')
2466                         vc->vc_G0_charset = LAT1_MAP;
2467                 else if (c == 'U')
2468                         vc->vc_G0_charset = IBMPC_MAP;
2469                 else if (c == 'K')
2470                         vc->vc_G0_charset = USER_MAP;
2471                 if (vc->vc_charset == 0)
2472                         vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2473                 vc->vc_state = ESnormal;
2474                 return;
2475         case ESsetG1:
2476                 if (c == '0')
2477                         vc->vc_G1_charset = GRAF_MAP;
2478                 else if (c == 'B')
2479                         vc->vc_G1_charset = LAT1_MAP;
2480                 else if (c == 'U')
2481                         vc->vc_G1_charset = IBMPC_MAP;
2482                 else if (c == 'K')
2483                         vc->vc_G1_charset = USER_MAP;
2484                 if (vc->vc_charset == 1)
2485                         vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2486                 vc->vc_state = ESnormal;
2487                 return;
2488         case ESosc:
2489                 return;
2490         default:
2491                 vc->vc_state = ESnormal;
2492         }
2493 }
2494
2495 /* is_double_width() is based on the wcwidth() implementation by
2496  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2497  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2498  */
2499 struct interval {
2500         uint32_t first;
2501         uint32_t last;
2502 };
2503
2504 static int ucs_cmp(const void *key, const void *elt)
2505 {
2506         uint32_t ucs = *(uint32_t *)key;
2507         struct interval e = *(struct interval *) elt;
2508
2509         if (ucs > e.last)
2510                 return 1;
2511         else if (ucs < e.first)
2512                 return -1;
2513         return 0;
2514 }
2515
2516 static int is_double_width(uint32_t ucs)
2517 {
2518         static const struct interval double_width[] = {
2519                 { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2520                 { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2521                 { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2522                 { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2523         };
2524         if (ucs < double_width[0].first ||
2525             ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2526                 return 0;
2527
2528         return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2529                         sizeof(struct interval), ucs_cmp) != NULL;
2530 }
2531
2532 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2533                 unsigned long draw_to, int *draw_x)
2534 {
2535         if (*draw_x < 0)
2536                 return;
2537
2538         vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2539                         (u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2540         *draw_x = -1;
2541 }
2542
2543 /* acquires console_lock */
2544 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2545 {
2546         int c, next_c, tc, ok, n = 0, draw_x = -1;
2547         unsigned int currcons;
2548         unsigned long draw_from = 0, draw_to = 0;
2549         struct vc_data *vc;
2550         unsigned char vc_attr;
2551         struct vt_notifier_param param;
2552         uint8_t rescan;
2553         uint8_t inverse;
2554         uint8_t width;
2555         u16 himask, charmask;
2556
2557         if (in_interrupt())
2558                 return count;
2559
2560         might_sleep();
2561
2562         console_lock();
2563         vc = tty->driver_data;
2564         if (vc == NULL) {
2565                 pr_err("vt: argh, driver_data is NULL !\n");
2566                 console_unlock();
2567                 return 0;
2568         }
2569
2570         currcons = vc->vc_num;
2571         if (!vc_cons_allocated(currcons)) {
2572                 /* could this happen? */
2573                 pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2574                 console_unlock();
2575                 return 0;
2576         }
2577
2578         himask = vc->vc_hi_font_mask;
2579         charmask = himask ? 0x1ff : 0xff;
2580
2581         /* undraw cursor first */
2582         if (con_is_fg(vc))
2583                 hide_cursor(vc);
2584
2585         param.vc = vc;
2586
2587         while (!tty->stopped && count) {
2588                 int orig = *buf;
2589                 c = orig;
2590                 buf++;
2591                 n++;
2592                 count--;
2593                 rescan = 0;
2594                 inverse = 0;
2595                 width = 1;
2596
2597                 /* Do no translation at all in control states */
2598                 if (vc->vc_state != ESnormal) {
2599                         tc = c;
2600                 } else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2601                     /* Combine UTF-8 into Unicode in vc_utf_char.
2602                      * vc_utf_count is the number of continuation bytes still
2603                      * expected to arrive.
2604                      * vc_npar is the number of continuation bytes arrived so
2605                      * far
2606                      */
2607 rescan_last_byte:
2608                     if ((c & 0xc0) == 0x80) {
2609                         /* Continuation byte received */
2610                         static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2611                         if (vc->vc_utf_count) {
2612                             vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2613                             vc->vc_npar++;
2614                             if (--vc->vc_utf_count) {
2615                                 /* Still need some bytes */
2616                                 continue;
2617                             }
2618                             /* Got a whole character */
2619                             c = vc->vc_utf_char;
2620                             /* Reject overlong sequences */
2621                             if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2622                                         c > utf8_length_changes[vc->vc_npar])
2623                                 c = 0xfffd;
2624                         } else {
2625                             /* Unexpected continuation byte */
2626                             vc->vc_utf_count = 0;
2627                             c = 0xfffd;
2628                         }
2629                     } else {
2630                         /* Single ASCII byte or first byte of a sequence received */
2631                         if (vc->vc_utf_count) {
2632                             /* Continuation byte expected */
2633                             rescan = 1;
2634                             vc->vc_utf_count = 0;
2635                             c = 0xfffd;
2636                         } else if (c > 0x7f) {
2637                             /* First byte of a multibyte sequence received */
2638                             vc->vc_npar = 0;
2639                             if ((c & 0xe0) == 0xc0) {
2640                                 vc->vc_utf_count = 1;
2641                                 vc->vc_utf_char = (c & 0x1f);
2642                             } else if ((c & 0xf0) == 0xe0) {
2643                                 vc->vc_utf_count = 2;
2644                                 vc->vc_utf_char = (c & 0x0f);
2645                             } else if ((c & 0xf8) == 0xf0) {
2646                                 vc->vc_utf_count = 3;
2647                                 vc->vc_utf_char = (c & 0x07);
2648                             } else if ((c & 0xfc) == 0xf8) {
2649                                 vc->vc_utf_count = 4;
2650                                 vc->vc_utf_char = (c & 0x03);
2651                             } else if ((c & 0xfe) == 0xfc) {
2652                                 vc->vc_utf_count = 5;
2653                                 vc->vc_utf_char = (c & 0x01);
2654                             } else {
2655                                 /* 254 and 255 are invalid */
2656                                 c = 0xfffd;
2657                             }
2658                             if (vc->vc_utf_count) {
2659                                 /* Still need some bytes */
2660                                 continue;
2661                             }
2662                         }
2663                         /* Nothing to do if an ASCII byte was received */
2664                     }
2665                     /* End of UTF-8 decoding. */
2666                     /* c is the received character, or U+FFFD for invalid sequences. */
2667                     /* Replace invalid Unicode code points with U+FFFD too */
2668                     if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2669                         c = 0xfffd;
2670                     tc = c;
2671                 } else {        /* no utf or alternate charset mode */
2672                     tc = vc_translate(vc, c);
2673                 }
2674
2675                 param.c = tc;
2676                 if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2677                                         &param) == NOTIFY_STOP)
2678                         continue;
2679
2680                 /* If the original code was a control character we
2681                  * only allow a glyph to be displayed if the code is
2682                  * not normally used (such as for cursor movement) or
2683                  * if the disp_ctrl mode has been explicitly enabled.
2684                  * Certain characters (as given by the CTRL_ALWAYS
2685                  * bitmap) are always displayed as control characters,
2686                  * as the console would be pretty useless without
2687                  * them; to display an arbitrary font position use the
2688                  * direct-to-font zone in UTF-8 mode.
2689                  */
2690                 ok = tc && (c >= 32 ||
2691                             !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2692                                   vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2693                         && (c != 127 || vc->vc_disp_ctrl)
2694                         && (c != 128+27);
2695
2696                 if (vc->vc_state == ESnormal && ok) {
2697                         if (vc->vc_utf && !vc->vc_disp_ctrl) {
2698                                 if (is_double_width(c))
2699                                         width = 2;
2700                         }
2701                         /* Now try to find out how to display it */
2702                         tc = conv_uni_to_pc(vc, tc);
2703                         if (tc & ~charmask) {
2704                                 if (tc == -1 || tc == -2) {
2705                                     continue; /* nothing to display */
2706                                 }
2707                                 /* Glyph not found */
2708                                 if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2709                                     /* In legacy mode use the glyph we get by a 1:1 mapping.
2710                                        This would make absolutely no sense with Unicode in mind,
2711                                        but do this for ASCII characters since a font may lack
2712                                        Unicode mapping info and we don't want to end up with
2713                                        having question marks only. */
2714                                     tc = c;
2715                                 } else {
2716                                     /* Display U+FFFD. If it's not found, display an inverse question mark. */
2717                                     tc = conv_uni_to_pc(vc, 0xfffd);
2718                                     if (tc < 0) {
2719                                         inverse = 1;
2720                                         tc = conv_uni_to_pc(vc, '?');
2721                                         if (tc < 0) tc = '?';
2722                                     }
2723                                 }
2724                         }
2725
2726                         if (!inverse) {
2727                                 vc_attr = vc->vc_attr;
2728                         } else {
2729                                 /* invert vc_attr */
2730                                 if (!vc->vc_can_do_color) {
2731                                         vc_attr = (vc->vc_attr) ^ 0x08;
2732                                 } else if (vc->vc_hi_font_mask == 0x100) {
2733                                         vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2734                                 } else {
2735                                         vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2736                                 }
2737                                 con_flush(vc, draw_from, draw_to, &draw_x);
2738                         }
2739
2740                         next_c = c;
2741                         while (1) {
2742                                 if (vc->vc_need_wrap || vc->vc_decim)
2743                                         con_flush(vc, draw_from, draw_to,
2744                                                         &draw_x);
2745                                 if (vc->vc_need_wrap) {
2746                                         cr(vc);
2747                                         lf(vc);
2748                                 }
2749                                 if (vc->vc_decim)
2750                                         insert_char(vc, 1);
2751                                 vc_uniscr_putc(vc, next_c);
2752                                 scr_writew(himask ?
2753                                              ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2754                                              (vc_attr << 8) + tc,
2755                                            (u16 *) vc->vc_pos);
2756                                 if (con_should_update(vc) && draw_x < 0) {
2757                                         draw_x = vc->vc_x;
2758                                         draw_from = vc->vc_pos;
2759                                 }
2760                                 if (vc->vc_x == vc->vc_cols - 1) {
2761                                         vc->vc_need_wrap = vc->vc_decawm;
2762                                         draw_to = vc->vc_pos + 2;
2763                                 } else {
2764                                         vc->vc_x++;
2765                                         draw_to = (vc->vc_pos += 2);
2766                                 }
2767
2768                                 if (!--width) break;
2769
2770                                 tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2771                                 if (tc < 0) tc = ' ';
2772                                 next_c = ' ';
2773                         }
2774                         notify_write(vc, c);
2775
2776                         if (inverse)
2777                                 con_flush(vc, draw_from, draw_to, &draw_x);
2778
2779                         if (rescan) {
2780                                 rescan = 0;
2781                                 inverse = 0;
2782                                 width = 1;
2783                                 c = orig;
2784                                 goto rescan_last_byte;
2785                         }
2786                         continue;
2787                 }
2788                 con_flush(vc, draw_from, draw_to, &draw_x);
2789                 do_con_trol(tty, vc, orig);
2790         }
2791         con_flush(vc, draw_from, draw_to, &draw_x);
2792         vc_uniscr_debug_check(vc);
2793         console_conditional_schedule();
2794         notify_update(vc);
2795         console_unlock();
2796         return n;
2797 }
2798
2799 /*
2800  * This is the console switching callback.
2801  *
2802  * Doing console switching in a process context allows
2803  * us to do the switches asynchronously (needed when we want
2804  * to switch due to a keyboard interrupt).  Synchronization
2805  * with other console code and prevention of re-entrancy is
2806  * ensured with console_lock.
2807  */
2808 static void console_callback(struct work_struct *ignored)
2809 {
2810         console_lock();
2811
2812         if (want_console >= 0) {
2813                 if (want_console != fg_console &&
2814                     vc_cons_allocated(want_console)) {
2815                         hide_cursor(vc_cons[fg_console].d);
2816                         change_console(vc_cons[want_console].d);
2817                         /* we only changed when the console had already
2818                            been allocated - a new console is not created
2819                            in an interrupt routine */
2820                 }
2821                 want_console = -1;
2822         }
2823         if (do_poke_blanked_console) { /* do not unblank for a LED change */
2824                 do_poke_blanked_console = 0;
2825                 poke_blanked_console();
2826         }
2827         if (scrollback_delta) {
2828                 struct vc_data *vc = vc_cons[fg_console].d;
2829                 clear_selection();
2830                 if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2831                         vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2832                 scrollback_delta = 0;
2833         }
2834         if (blank_timer_expired) {
2835                 do_blank_screen(0);
2836                 blank_timer_expired = 0;
2837         }
2838         notify_update(vc_cons[fg_console].d);
2839
2840         console_unlock();
2841 }
2842
2843 int set_console(int nr)
2844 {
2845         struct vc_data *vc = vc_cons[fg_console].d;
2846
2847         if (!vc_cons_allocated(nr) || vt_dont_switch ||
2848                 (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2849
2850                 /*
2851                  * Console switch will fail in console_callback() or
2852                  * change_console() so there is no point scheduling
2853                  * the callback
2854                  *
2855                  * Existing set_console() users don't check the return
2856                  * value so this shouldn't break anything
2857                  */
2858                 return -EINVAL;
2859         }
2860
2861         want_console = nr;
2862         schedule_console_callback();
2863
2864         return 0;
2865 }
2866
2867 struct tty_driver *console_driver;
2868
2869 #ifdef CONFIG_VT_CONSOLE
2870
2871 /**
2872  * vt_kmsg_redirect() - Sets/gets the kernel message console
2873  * @new:        The new virtual terminal number or -1 if the console should stay
2874  *              unchanged
2875  *
2876  * By default, the kernel messages are always printed on the current virtual
2877  * console. However, the user may modify that default with the
2878  * TIOCL_SETKMSGREDIRECT ioctl call.
2879  *
2880  * This function sets the kernel message console to be @new. It returns the old
2881  * virtual console number. The virtual terminal number 0 (both as parameter and
2882  * return value) means no redirection (i.e. always printed on the currently
2883  * active console).
2884  *
2885  * The parameter -1 means that only the current console is returned, but the
2886  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2887  * case to make the code more understandable.
2888  *
2889  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2890  * the parameter and always returns 0.
2891  */
2892 int vt_kmsg_redirect(int new)
2893 {
2894         static int kmsg_con;
2895
2896         if (new != -1)
2897                 return xchg(&kmsg_con, new);
2898         else
2899                 return kmsg_con;
2900 }
2901
2902 /*
2903  *      Console on virtual terminal
2904  *
2905  * The console must be locked when we get here.
2906  */
2907
2908 static void vt_console_print(struct console *co, const char *b, unsigned count)
2909 {
2910         struct vc_data *vc = vc_cons[fg_console].d;
2911         unsigned char c;
2912         static DEFINE_SPINLOCK(printing_lock);
2913         const ushort *start;
2914         ushort start_x, cnt;
2915         int kmsg_console;
2916
2917         /* console busy or not yet initialized */
2918         if (!printable)
2919                 return;
2920         if (!spin_trylock(&printing_lock))
2921                 return;
2922
2923         kmsg_console = vt_get_kmsg_redirect();
2924         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2925                 vc = vc_cons[kmsg_console - 1].d;
2926
2927         if (!vc_cons_allocated(fg_console)) {
2928                 /* impossible */
2929                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2930                 goto quit;
2931         }
2932
2933         if (vc->vc_mode != KD_TEXT)
2934                 goto quit;
2935
2936         /* undraw cursor first */
2937         if (con_is_fg(vc))
2938                 hide_cursor(vc);
2939
2940         start = (ushort *)vc->vc_pos;
2941         start_x = vc->vc_x;
2942         cnt = 0;
2943         while (count--) {
2944                 c = *b++;
2945                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2946                         if (cnt && con_is_visible(vc))
2947                                 vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x);
2948                         cnt = 0;
2949                         if (c == 8) {           /* backspace */
2950                                 bs(vc);
2951                                 start = (ushort *)vc->vc_pos;
2952                                 start_x = vc->vc_x;
2953                                 continue;
2954                         }
2955                         if (c != 13)
2956                                 lf(vc);
2957                         cr(vc);
2958                         start = (ushort *)vc->vc_pos;
2959                         start_x = vc->vc_x;
2960                         if (c == 10 || c == 13)
2961                                 continue;
2962                 }
2963                 vc_uniscr_putc(vc, c);
2964                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2965                 notify_write(vc, c);
2966                 cnt++;
2967                 if (vc->vc_x == vc->vc_cols - 1) {
2968                         vc->vc_need_wrap = 1;
2969                 } else {
2970                         vc->vc_pos += 2;
2971                         vc->vc_x++;
2972                 }
2973         }
2974         if (cnt && con_is_visible(vc))
2975                 vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x);
2976         set_cursor(vc);
2977         notify_update(vc);
2978
2979 quit:
2980         spin_unlock(&printing_lock);
2981 }
2982
2983 static struct tty_driver *vt_console_device(struct console *c, int *index)
2984 {
2985         *index = c->index ? c->index-1 : fg_console;
2986         return console_driver;
2987 }
2988
2989 static struct console vt_console_driver = {
2990         .name           = "tty",
2991         .write          = vt_console_print,
2992         .device         = vt_console_device,
2993         .unblank        = unblank_screen,
2994         .flags          = CON_PRINTBUFFER,
2995         .index          = -1,
2996 };
2997 #endif
2998
2999 /*
3000  *      Handling of Linux-specific VC ioctls
3001  */
3002
3003 /*
3004  * Generally a bit racy with respect to console_lock();.
3005  *
3006  * There are some functions which don't need it.
3007  *
3008  * There are some functions which can sleep for arbitrary periods
3009  * (paste_selection) but we don't need the lock there anyway.
3010  *
3011  * set_selection has locking, and definitely needs it
3012  */
3013
3014 int tioclinux(struct tty_struct *tty, unsigned long arg)
3015 {
3016         char type, data;
3017         char __user *p = (char __user *)arg;
3018         int lines;
3019         int ret;
3020
3021         if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3022                 return -EPERM;
3023         if (get_user(type, p))
3024                 return -EFAULT;
3025         ret = 0;
3026
3027         switch (type)
3028         {
3029                 case TIOCL_SETSEL:
3030                         console_lock();
3031                         ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
3032                         console_unlock();
3033                         break;
3034                 case TIOCL_PASTESEL:
3035                         ret = paste_selection(tty);
3036                         break;
3037                 case TIOCL_UNBLANKSCREEN:
3038                         console_lock();
3039                         unblank_screen();
3040                         console_unlock();
3041                         break;
3042                 case TIOCL_SELLOADLUT:
3043                         console_lock();
3044                         ret = sel_loadlut(p);
3045                         console_unlock();
3046                         break;
3047                 case TIOCL_GETSHIFTSTATE:
3048
3049         /*
3050          * Make it possible to react to Shift+Mousebutton.
3051          * Note that 'shift_state' is an undocumented
3052          * kernel-internal variable; programs not closely
3053          * related to the kernel should not use this.
3054          */
3055                         data = vt_get_shift_state();
3056                         ret = put_user(data, p);
3057                         break;
3058                 case TIOCL_GETMOUSEREPORTING:
3059                         console_lock(); /* May be overkill */
3060                         data = mouse_reporting();
3061                         console_unlock();
3062                         ret = put_user(data, p);
3063                         break;
3064                 case TIOCL_SETVESABLANK:
3065                         console_lock();
3066                         ret = set_vesa_blanking(p);
3067                         console_unlock();
3068                         break;
3069                 case TIOCL_GETKMSGREDIRECT:
3070                         data = vt_get_kmsg_redirect();
3071                         ret = put_user(data, p);
3072                         break;
3073                 case TIOCL_SETKMSGREDIRECT:
3074                         if (!capable(CAP_SYS_ADMIN)) {
3075                                 ret = -EPERM;
3076                         } else {
3077                                 if (get_user(data, p+1))
3078                                         ret = -EFAULT;
3079                                 else
3080                                         vt_kmsg_redirect(data);
3081                         }
3082                         break;
3083                 case TIOCL_GETFGCONSOLE:
3084                         /* No locking needed as this is a transiently
3085                            correct return anyway if the caller hasn't
3086                            disabled switching */
3087                         ret = fg_console;
3088                         break;
3089                 case TIOCL_SCROLLCONSOLE:
3090                         if (get_user(lines, (s32 __user *)(p+4))) {
3091                                 ret = -EFAULT;
3092                         } else {
3093                                 /* Need the console lock here. Note that lots
3094                                    of other calls need fixing before the lock
3095                                    is actually useful ! */
3096                                 console_lock();
3097                                 scrollfront(vc_cons[fg_console].d, lines);
3098                                 console_unlock();
3099                                 ret = 0;
3100                         }
3101                         break;
3102                 case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
3103                         console_lock();
3104                         ignore_poke = 1;
3105                         do_blank_screen(0);
3106                         console_unlock();
3107                         break;
3108                 case TIOCL_BLANKEDSCREEN:
3109                         ret = console_blanked;
3110                         break;
3111                 default:
3112                         ret = -EINVAL;
3113                         break;
3114         }
3115         return ret;
3116 }
3117
3118 /*
3119  * /dev/ttyN handling
3120  */
3121
3122 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3123 {
3124         int     retval;
3125
3126         retval = do_con_write(tty, buf, count);
3127         con_flush_chars(tty);
3128
3129         return retval;
3130 }
3131
3132 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3133 {
3134         if (in_interrupt())
3135                 return 0;       /* n_r3964 calls put_char() from interrupt context */
3136         return do_con_write(tty, &ch, 1);
3137 }
3138
3139 static int con_write_room(struct tty_struct *tty)
3140 {
3141         if (tty->stopped)
3142                 return 0;
3143         return 32768;           /* No limit, really; we're not buffering */
3144 }
3145
3146 static int con_chars_in_buffer(struct tty_struct *tty)
3147 {
3148         return 0;               /* we're not buffering */
3149 }
3150
3151 /*
3152  * con_throttle and con_unthrottle are only used for
3153  * paste_selection(), which has to stuff in a large number of
3154  * characters...
3155  */
3156 static void con_throttle(struct tty_struct *tty)
3157 {
3158 }
3159
3160 static void con_unthrottle(struct tty_struct *tty)
3161 {
3162         struct vc_data *vc = tty->driver_data;
3163
3164         wake_up_interruptible(&vc->paste_wait);
3165 }
3166
3167 /*
3168  * Turn the Scroll-Lock LED on when the tty is stopped
3169  */
3170 static void con_stop(struct tty_struct *tty)
3171 {
3172         int console_num;
3173         if (!tty)
3174                 return;
3175         console_num = tty->index;
3176         if (!vc_cons_allocated(console_num))
3177                 return;
3178         vt_kbd_con_stop(console_num);
3179 }
3180
3181 /*
3182  * Turn the Scroll-Lock LED off when the console is started
3183  */
3184 static void con_start(struct tty_struct *tty)
3185 {
3186         int console_num;
3187         if (!tty)
3188                 return;
3189         console_num = tty->index;
3190         if (!vc_cons_allocated(console_num))
3191                 return;
3192         vt_kbd_con_start(console_num);
3193 }
3194
3195 static void con_flush_chars(struct tty_struct *tty)
3196 {
3197         struct vc_data *vc;
3198
3199         if (in_interrupt())     /* from flush_to_ldisc */
3200                 return;
3201
3202         /* if we race with con_close(), vt may be null */
3203         console_lock();
3204         vc = tty->driver_data;
3205         if (vc)
3206                 set_cursor(vc);
3207         console_unlock();
3208 }
3209
3210 /*
3211  * Allocate the console screen memory.
3212  */
3213 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3214 {
3215         unsigned int currcons = tty->index;
3216         struct vc_data *vc;
3217         int ret;
3218
3219         console_lock();
3220         ret = vc_allocate(currcons);
3221         if (ret)
3222                 goto unlock;
3223
3224         vc = vc_cons[currcons].d;
3225
3226         /* Still being freed */
3227         if (vc->port.tty) {
3228                 ret = -ERESTARTSYS;
3229                 goto unlock;
3230         }
3231
3232         ret = tty_port_install(&vc->port, driver, tty);
3233         if (ret)
3234                 goto unlock;
3235
3236         tty->driver_data = vc;
3237         vc->port.tty = tty;
3238
3239         if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3240                 tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3241                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3242         }
3243         if (vc->vc_utf)
3244                 tty->termios.c_iflag |= IUTF8;
3245         else
3246                 tty->termios.c_iflag &= ~IUTF8;
3247 unlock:
3248         console_unlock();
3249         return ret;
3250 }
3251
3252 static int con_open(struct tty_struct *tty, struct file *filp)
3253 {
3254         /* everything done in install */
3255         return 0;
3256 }
3257
3258
3259 static void con_close(struct tty_struct *tty, struct file *filp)
3260 {
3261         /* Nothing to do - we defer to shutdown */
3262 }
3263
3264 static void con_shutdown(struct tty_struct *tty)
3265 {
3266         struct vc_data *vc = tty->driver_data;
3267         BUG_ON(vc == NULL);
3268         console_lock();
3269         vc->port.tty = NULL;
3270         console_unlock();
3271 }
3272
3273 static int default_color           = 7; /* white */
3274 static int default_italic_color    = 2; // green (ASCII)
3275 static int default_underline_color = 3; // cyan (ASCII)
3276 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3277 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3278 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3279
3280 static void vc_init(struct vc_data *vc, unsigned int rows,
3281                     unsigned int cols, int do_clear)
3282 {
3283         int j, k ;
3284
3285         vc->vc_cols = cols;
3286         vc->vc_rows = rows;
3287         vc->vc_size_row = cols << 1;
3288         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3289
3290         set_origin(vc);
3291         vc->vc_pos = vc->vc_origin;
3292         reset_vc(vc);
3293         for (j=k=0; j<16; j++) {
3294                 vc->vc_palette[k++] = default_red[j] ;
3295                 vc->vc_palette[k++] = default_grn[j] ;
3296                 vc->vc_palette[k++] = default_blu[j] ;
3297         }
3298         vc->vc_def_color       = default_color;
3299         vc->vc_ulcolor         = default_underline_color;
3300         vc->vc_itcolor         = default_italic_color;
3301         vc->vc_halfcolor       = 0x08;   /* grey */
3302         init_waitqueue_head(&vc->paste_wait);
3303         reset_terminal(vc, do_clear);
3304 }
3305
3306 /*
3307  * This routine initializes console interrupts, and does nothing
3308  * else. If you want the screen to clear, call tty_write with
3309  * the appropriate escape-sequence.
3310  */
3311
3312 static int __init con_init(void)
3313 {
3314         const char *display_desc = NULL;
3315         struct vc_data *vc;
3316         unsigned int currcons = 0, i;
3317
3318         console_lock();
3319
3320         if (conswitchp)
3321                 display_desc = conswitchp->con_startup();
3322         if (!display_desc) {
3323                 fg_console = 0;
3324                 console_unlock();
3325                 return 0;
3326         }
3327
3328         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3329                 struct con_driver *con_driver = &registered_con_driver[i];
3330
3331                 if (con_driver->con == NULL) {
3332                         con_driver->con = conswitchp;
3333                         con_driver->desc = display_desc;
3334                         con_driver->flag = CON_DRIVER_FLAG_INIT;
3335                         con_driver->first = 0;
3336                         con_driver->last = MAX_NR_CONSOLES - 1;
3337                         break;
3338                 }
3339         }
3340
3341         for (i = 0; i < MAX_NR_CONSOLES; i++)
3342                 con_driver_map[i] = conswitchp;
3343
3344         if (blankinterval) {
3345                 blank_state = blank_normal_wait;
3346                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3347         }
3348
3349         for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3350                 vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3351                 INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3352                 tty_port_init(&vc->port);
3353                 visual_init(vc, currcons, 1);
3354                 vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3355                 vc_init(vc, vc->vc_rows, vc->vc_cols,
3356                         currcons || !vc->vc_sw->con_save_screen);
3357         }
3358         currcons = fg_console = 0;
3359         master_display_fg = vc = vc_cons[currcons].d;
3360         set_origin(vc);
3361         save_screen(vc);
3362         gotoxy(vc, vc->vc_x, vc->vc_y);
3363         csi_J(vc, 0);
3364         update_screen(vc);
3365         pr_info("Console: %s %s %dx%d\n",
3366                 vc->vc_can_do_color ? "colour" : "mono",
3367                 display_desc, vc->vc_cols, vc->vc_rows);
3368         printable = 1;
3369
3370         console_unlock();
3371
3372 #ifdef CONFIG_VT_CONSOLE
3373         register_console(&vt_console_driver);
3374 #endif
3375         return 0;
3376 }
3377 console_initcall(con_init);
3378
3379 static const struct tty_operations con_ops = {
3380         .install = con_install,
3381         .open = con_open,
3382         .close = con_close,
3383         .write = con_write,
3384         .write_room = con_write_room,
3385         .put_char = con_put_char,
3386         .flush_chars = con_flush_chars,
3387         .chars_in_buffer = con_chars_in_buffer,
3388         .ioctl = vt_ioctl,
3389 #ifdef CONFIG_COMPAT
3390         .compat_ioctl = vt_compat_ioctl,
3391 #endif
3392         .stop = con_stop,
3393         .start = con_start,
3394         .throttle = con_throttle,
3395         .unthrottle = con_unthrottle,
3396         .resize = vt_resize,
3397         .shutdown = con_shutdown
3398 };
3399
3400 static struct cdev vc0_cdev;
3401
3402 static ssize_t show_tty_active(struct device *dev,
3403                                 struct device_attribute *attr, char *buf)
3404 {
3405         return sprintf(buf, "tty%d\n", fg_console + 1);
3406 }
3407 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3408
3409 static struct attribute *vt_dev_attrs[] = {
3410         &dev_attr_active.attr,
3411         NULL
3412 };
3413
3414 ATTRIBUTE_GROUPS(vt_dev);
3415
3416 int __init vty_init(const struct file_operations *console_fops)
3417 {
3418         cdev_init(&vc0_cdev, console_fops);
3419         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3420             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3421                 panic("Couldn't register /dev/tty0 driver\n");
3422         tty0dev = device_create_with_groups(tty_class, NULL,
3423                                             MKDEV(TTY_MAJOR, 0), NULL,
3424                                             vt_dev_groups, "tty0");
3425         if (IS_ERR(tty0dev))
3426                 tty0dev = NULL;
3427
3428         vcs_init();
3429
3430         console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3431         if (!console_driver)
3432                 panic("Couldn't allocate console driver\n");
3433
3434         console_driver->name = "tty";
3435         console_driver->name_base = 1;
3436         console_driver->major = TTY_MAJOR;
3437         console_driver->minor_start = 1;
3438         console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3439         console_driver->init_termios = tty_std_termios;
3440         if (default_utf8)
3441                 console_driver->init_termios.c_iflag |= IUTF8;
3442         console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3443         tty_set_operations(console_driver, &con_ops);
3444         if (tty_register_driver(console_driver))
3445                 panic("Couldn't register console driver\n");
3446         kbd_init();
3447         console_map_init();
3448 #ifdef CONFIG_MDA_CONSOLE
3449         mda_console_init();
3450 #endif
3451         return 0;
3452 }
3453
3454 #ifndef VT_SINGLE_DRIVER
3455
3456 static struct class *vtconsole_class;
3457
3458 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3459                            int deflt)
3460 {
3461         struct module *owner = csw->owner;
3462         const char *desc = NULL;
3463         struct con_driver *con_driver;
3464         int i, j = -1, k = -1, retval = -ENODEV;
3465
3466         if (!try_module_get(owner))
3467                 return -ENODEV;
3468
3469         WARN_CONSOLE_UNLOCKED();
3470
3471         /* check if driver is registered */
3472         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3473                 con_driver = &registered_con_driver[i];
3474
3475                 if (con_driver->con == csw) {
3476                         desc = con_driver->desc;
3477                         retval = 0;
3478                         break;
3479                 }
3480         }
3481
3482         if (retval)
3483                 goto err;
3484
3485         if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3486                 csw->con_startup();
3487                 con_driver->flag |= CON_DRIVER_FLAG_INIT;
3488         }
3489
3490         if (deflt) {
3491                 if (conswitchp)
3492                         module_put(conswitchp->owner);
3493
3494                 __module_get(owner);
3495                 conswitchp = csw;
3496         }
3497
3498         first = max(first, con_driver->first);
3499         last = min(last, con_driver->last);
3500
3501         for (i = first; i <= last; i++) {
3502                 int old_was_color;
3503                 struct vc_data *vc = vc_cons[i].d;
3504
3505                 if (con_driver_map[i])
3506                         module_put(con_driver_map[i]->owner);
3507                 __module_get(owner);
3508                 con_driver_map[i] = csw;
3509
3510                 if (!vc || !vc->vc_sw)
3511                         continue;
3512
3513                 j = i;
3514
3515                 if (con_is_visible(vc)) {
3516                         k = i;
3517                         save_screen(vc);
3518                 }
3519
3520                 old_was_color = vc->vc_can_do_color;
3521                 vc->vc_sw->con_deinit(vc);
3522                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3523                 visual_init(vc, i, 0);
3524                 set_origin(vc);
3525                 update_attr(vc);
3526
3527                 /* If the console changed between mono <-> color, then
3528                  * the attributes in the screenbuf will be wrong.  The
3529                  * following resets all attributes to something sane.
3530                  */
3531                 if (old_was_color != vc->vc_can_do_color)
3532                         clear_buffer_attributes(vc);
3533         }
3534
3535         pr_info("Console: switching ");
3536         if (!deflt)
3537                 pr_cont("consoles %d-%d ", first + 1, last + 1);
3538         if (j >= 0) {
3539                 struct vc_data *vc = vc_cons[j].d;
3540
3541                 pr_cont("to %s %s %dx%d\n",
3542                         vc->vc_can_do_color ? "colour" : "mono",
3543                         desc, vc->vc_cols, vc->vc_rows);
3544
3545                 if (k >= 0) {
3546                         vc = vc_cons[k].d;
3547                         update_screen(vc);
3548                 }
3549         } else {
3550                 pr_cont("to %s\n", desc);
3551         }
3552
3553         retval = 0;
3554 err:
3555         module_put(owner);
3556         return retval;
3557 };
3558
3559
3560 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3561 /* unlocked version of unbind_con_driver() */
3562 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3563 {
3564         struct module *owner = csw->owner;
3565         const struct consw *defcsw = NULL;
3566         struct con_driver *con_driver = NULL, *con_back = NULL;
3567         int i, retval = -ENODEV;
3568
3569         if (!try_module_get(owner))
3570                 return -ENODEV;
3571
3572         WARN_CONSOLE_UNLOCKED();
3573
3574         /* check if driver is registered and if it is unbindable */
3575         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3576                 con_driver = &registered_con_driver[i];
3577
3578                 if (con_driver->con == csw &&
3579                     con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3580                         retval = 0;
3581                         break;
3582                 }
3583         }
3584
3585         if (retval)
3586                 goto err;
3587
3588         retval = -ENODEV;
3589
3590         /* check if backup driver exists */
3591         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3592                 con_back = &registered_con_driver[i];
3593
3594                 if (con_back->con && con_back->con != csw) {
3595                         defcsw = con_back->con;
3596                         retval = 0;
3597                         break;
3598                 }
3599         }
3600
3601         if (retval)
3602                 goto err;
3603
3604         if (!con_is_bound(csw))
3605                 goto err;
3606
3607         first = max(first, con_driver->first);
3608         last = min(last, con_driver->last);
3609
3610         for (i = first; i <= last; i++) {
3611                 if (con_driver_map[i] == csw) {
3612                         module_put(csw->owner);
3613                         con_driver_map[i] = NULL;
3614                 }
3615         }
3616
3617         if (!con_is_bound(defcsw)) {
3618                 const struct consw *defconsw = conswitchp;
3619
3620                 defcsw->con_startup();
3621                 con_back->flag |= CON_DRIVER_FLAG_INIT;
3622                 /*
3623                  * vgacon may change the default driver to point
3624                  * to dummycon, we restore it here...
3625                  */
3626                 conswitchp = defconsw;
3627         }
3628
3629         if (!con_is_bound(csw))
3630                 con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3631
3632         /* ignore return value, binding should not fail */
3633         do_bind_con_driver(defcsw, first, last, deflt);
3634 err:
3635         module_put(owner);
3636         return retval;
3637
3638 }
3639 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3640
3641 static int vt_bind(struct con_driver *con)
3642 {
3643         const struct consw *defcsw = NULL, *csw = NULL;
3644         int i, more = 1, first = -1, last = -1, deflt = 0;
3645
3646         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3647                 goto err;
3648
3649         csw = con->con;
3650
3651         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3652                 struct con_driver *con = &registered_con_driver[i];
3653
3654                 if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3655                         defcsw = con->con;
3656                         break;
3657                 }
3658         }
3659
3660         if (!defcsw)
3661                 goto err;
3662
3663         while (more) {
3664                 more = 0;
3665
3666                 for (i = con->first; i <= con->last; i++) {
3667                         if (con_driver_map[i] == defcsw) {
3668                                 if (first == -1)
3669                                         first = i;
3670                                 last = i;
3671                                 more = 1;
3672                         } else if (first != -1)
3673                                 break;
3674                 }
3675
3676                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3677                         deflt = 1;
3678
3679                 if (first != -1)
3680                         do_bind_con_driver(csw, first, last, deflt);
3681
3682                 first = -1;
3683                 last = -1;
3684                 deflt = 0;
3685         }
3686
3687 err:
3688         return 0;
3689 }
3690
3691 static int vt_unbind(struct con_driver *con)
3692 {
3693         const struct consw *csw = NULL;
3694         int i, more = 1, first = -1, last = -1, deflt = 0;
3695         int ret;
3696
3697         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3698                 goto err;
3699
3700         csw = con->con;
3701
3702         while (more) {
3703                 more = 0;
3704
3705                 for (i = con->first; i <= con->last; i++) {
3706                         if (con_driver_map[i] == csw) {
3707                                 if (first == -1)
3708                                         first = i;
3709                                 last = i;
3710                                 more = 1;
3711                         } else if (first != -1)
3712                                 break;
3713                 }
3714
3715                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3716                         deflt = 1;
3717
3718                 if (first != -1) {
3719                         ret = do_unbind_con_driver(csw, first, last, deflt);
3720                         if (ret != 0)
3721                                 return ret;
3722                 }
3723
3724                 first = -1;
3725                 last = -1;
3726                 deflt = 0;
3727         }
3728
3729 err:
3730         return 0;
3731 }
3732 #else
3733 static inline int vt_bind(struct con_driver *con)
3734 {
3735         return 0;
3736 }
3737 static inline int vt_unbind(struct con_driver *con)
3738 {
3739         return 0;
3740 }
3741 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3742
3743 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3744                           const char *buf, size_t count)
3745 {
3746         struct con_driver *con = dev_get_drvdata(dev);
3747         int bind = simple_strtoul(buf, NULL, 0);
3748
3749         console_lock();
3750
3751         if (bind)
3752                 vt_bind(con);
3753         else
3754                 vt_unbind(con);
3755
3756         console_unlock();
3757
3758         return count;
3759 }
3760
3761 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3762                          char *buf)
3763 {
3764         struct con_driver *con = dev_get_drvdata(dev);
3765         int bind = con_is_bound(con->con);
3766
3767         return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3768 }
3769
3770 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3771                          char *buf)
3772 {
3773         struct con_driver *con = dev_get_drvdata(dev);
3774
3775         return snprintf(buf, PAGE_SIZE, "%s %s\n",
3776                         (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3777                          con->desc);
3778
3779 }
3780
3781 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3782 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3783
3784 static struct attribute *con_dev_attrs[] = {
3785         &dev_attr_bind.attr,
3786         &dev_attr_name.attr,
3787         NULL
3788 };
3789
3790 ATTRIBUTE_GROUPS(con_dev);
3791
3792 static int vtconsole_init_device(struct con_driver *con)
3793 {
3794         con->flag |= CON_DRIVER_FLAG_ATTR;
3795         return 0;
3796 }
3797
3798 static void vtconsole_deinit_device(struct con_driver *con)
3799 {
3800         con->flag &= ~CON_DRIVER_FLAG_ATTR;
3801 }
3802
3803 /**
3804  * con_is_bound - checks if driver is bound to the console
3805  * @csw: console driver
3806  *
3807  * RETURNS: zero if unbound, nonzero if bound
3808  *
3809  * Drivers can call this and if zero, they should release
3810  * all resources allocated on con_startup()
3811  */
3812 int con_is_bound(const struct consw *csw)
3813 {
3814         int i, bound = 0;
3815
3816         for (i = 0; i < MAX_NR_CONSOLES; i++) {
3817                 if (con_driver_map[i] == csw) {
3818                         bound = 1;
3819                         break;
3820                 }
3821         }
3822
3823         return bound;
3824 }
3825 EXPORT_SYMBOL(con_is_bound);
3826
3827 /**
3828  * con_debug_enter - prepare the console for the kernel debugger
3829  * @sw: console driver
3830  *
3831  * Called when the console is taken over by the kernel debugger, this
3832  * function needs to save the current console state, then put the console
3833  * into a state suitable for the kernel debugger.
3834  *
3835  * RETURNS:
3836  * Zero on success, nonzero if a failure occurred when trying to prepare
3837  * the console for the debugger.
3838  */
3839 int con_debug_enter(struct vc_data *vc)
3840 {
3841         int ret = 0;
3842
3843         saved_fg_console = fg_console;
3844         saved_last_console = last_console;
3845         saved_want_console = want_console;
3846         saved_vc_mode = vc->vc_mode;
3847         saved_console_blanked = console_blanked;
3848         vc->vc_mode = KD_TEXT;
3849         console_blanked = 0;
3850         if (vc->vc_sw->con_debug_enter)
3851                 ret = vc->vc_sw->con_debug_enter(vc);
3852 #ifdef CONFIG_KGDB_KDB
3853         /* Set the initial LINES variable if it is not already set */
3854         if (vc->vc_rows < 999) {
3855                 int linecount;
3856                 char lns[4];
3857                 const char *setargs[3] = {
3858                         "set",
3859                         "LINES",
3860                         lns,
3861                 };
3862                 if (kdbgetintenv(setargs[0], &linecount)) {
3863                         snprintf(lns, 4, "%i", vc->vc_rows);
3864                         kdb_set(2, setargs);
3865                 }
3866         }
3867         if (vc->vc_cols < 999) {
3868                 int colcount;
3869                 char cols[4];
3870                 const char *setargs[3] = {
3871                         "set",
3872                         "COLUMNS",
3873                         cols,
3874                 };
3875                 if (kdbgetintenv(setargs[0], &colcount)) {
3876                         snprintf(cols, 4, "%i", vc->vc_cols);
3877                         kdb_set(2, setargs);
3878                 }
3879         }
3880 #endif /* CONFIG_KGDB_KDB */
3881         return ret;
3882 }
3883 EXPORT_SYMBOL_GPL(con_debug_enter);
3884
3885 /**
3886  * con_debug_leave - restore console state
3887  * @sw: console driver
3888  *
3889  * Restore the console state to what it was before the kernel debugger
3890  * was invoked.
3891  *
3892  * RETURNS:
3893  * Zero on success, nonzero if a failure occurred when trying to restore
3894  * the console.
3895  */
3896 int con_debug_leave(void)
3897 {
3898         struct vc_data *vc;
3899         int ret = 0;
3900
3901         fg_console = saved_fg_console;
3902         last_console = saved_last_console;
3903         want_console = saved_want_console;
3904         console_blanked = saved_console_blanked;
3905         vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3906
3907         vc = vc_cons[fg_console].d;
3908         if (vc->vc_sw->con_debug_leave)
3909                 ret = vc->vc_sw->con_debug_leave(vc);
3910         return ret;
3911 }
3912 EXPORT_SYMBOL_GPL(con_debug_leave);
3913
3914 static int do_register_con_driver(const struct consw *csw, int first, int last)
3915 {
3916         struct module *owner = csw->owner;
3917         struct con_driver *con_driver;
3918         const char *desc;
3919         int i, retval;
3920
3921         WARN_CONSOLE_UNLOCKED();
3922
3923         if (!try_module_get(owner))
3924                 return -ENODEV;
3925
3926         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3927                 con_driver = &registered_con_driver[i];
3928
3929                 /* already registered */
3930                 if (con_driver->con == csw) {
3931                         retval = -EBUSY;
3932                         goto err;
3933                 }
3934         }
3935
3936         desc = csw->con_startup();
3937         if (!desc) {
3938                 retval = -ENODEV;
3939                 goto err;
3940         }
3941
3942         retval = -EINVAL;
3943
3944         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3945                 con_driver = &registered_con_driver[i];
3946
3947                 if (con_driver->con == NULL &&
3948                     !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3949                         con_driver->con = csw;
3950                         con_driver->desc = desc;
3951                         con_driver->node = i;
3952                         con_driver->flag = CON_DRIVER_FLAG_MODULE |
3953                                            CON_DRIVER_FLAG_INIT;
3954                         con_driver->first = first;
3955                         con_driver->last = last;
3956                         retval = 0;
3957                         break;
3958                 }
3959         }
3960
3961         if (retval)
3962                 goto err;
3963
3964         con_driver->dev =
3965                 device_create_with_groups(vtconsole_class, NULL,
3966                                           MKDEV(0, con_driver->node),
3967                                           con_driver, con_dev_groups,
3968                                           "vtcon%i", con_driver->node);
3969         if (IS_ERR(con_driver->dev)) {
3970                 pr_warn("Unable to create device for %s; errno = %ld\n",
3971                         con_driver->desc, PTR_ERR(con_driver->dev));
3972                 con_driver->dev = NULL;
3973         } else {
3974                 vtconsole_init_device(con_driver);
3975         }
3976
3977 err:
3978         module_put(owner);
3979         return retval;
3980 }
3981
3982
3983 /**
3984  * do_unregister_con_driver - unregister console driver from console layer
3985  * @csw: console driver
3986  *
3987  * DESCRIPTION: All drivers that registers to the console layer must
3988  * call this function upon exit, or if the console driver is in a state
3989  * where it won't be able to handle console services, such as the
3990  * framebuffer console without loaded framebuffer drivers.
3991  *
3992  * The driver must unbind first prior to unregistration.
3993  */
3994 int do_unregister_con_driver(const struct consw *csw)
3995 {
3996         int i;
3997
3998         /* cannot unregister a bound driver */
3999         if (con_is_bound(csw))
4000                 return -EBUSY;
4001
4002         if (csw == conswitchp)
4003                 return -EINVAL;
4004
4005         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4006                 struct con_driver *con_driver = &registered_con_driver[i];
4007
4008                 if (con_driver->con == csw) {
4009                         /*
4010                          * Defer the removal of the sysfs entries since that
4011                          * will acquire the kernfs s_active lock and we can't
4012                          * acquire this lock while holding the console lock:
4013                          * the unbind sysfs entry imposes already the opposite
4014                          * order. Reset con already here to prevent any later
4015                          * lookup to succeed and mark this slot as zombie, so
4016                          * it won't get reused until we complete the removal
4017                          * in the deferred work.
4018                          */
4019                         con_driver->con = NULL;
4020                         con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4021                         schedule_work(&con_driver_unregister_work);
4022
4023                         return 0;
4024                 }
4025         }
4026
4027         return -ENODEV;
4028 }
4029 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4030
4031 static void con_driver_unregister_callback(struct work_struct *ignored)
4032 {
4033         int i;
4034
4035         console_lock();
4036
4037         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4038                 struct con_driver *con_driver = &registered_con_driver[i];
4039
4040                 if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4041                         continue;
4042
4043                 console_unlock();
4044
4045                 vtconsole_deinit_device(con_driver);
4046                 device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4047
4048                 console_lock();
4049
4050                 if (WARN_ON_ONCE(con_driver->con))
4051                         con_driver->con = NULL;
4052                 con_driver->desc = NULL;
4053                 con_driver->dev = NULL;
4054                 con_driver->node = 0;
4055                 WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4056                 con_driver->flag = 0;
4057                 con_driver->first = 0;
4058                 con_driver->last = 0;
4059         }
4060
4061         console_unlock();
4062 }
4063
4064 /*
4065  *      If we support more console drivers, this function is used
4066  *      when a driver wants to take over some existing consoles
4067  *      and become default driver for newly opened ones.
4068  *
4069  *      do_take_over_console is basically a register followed by unbind
4070  */
4071 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4072 {
4073         int err;
4074
4075         err = do_register_con_driver(csw, first, last);
4076         /*
4077          * If we get an busy error we still want to bind the console driver
4078          * and return success, as we may have unbound the console driver
4079          * but not unregistered it.
4080          */
4081         if (err == -EBUSY)
4082                 err = 0;
4083         if (!err)
4084                 do_bind_con_driver(csw, first, last, deflt);
4085
4086         return err;
4087 }
4088 EXPORT_SYMBOL_GPL(do_take_over_console);
4089
4090
4091 /*
4092  * give_up_console is a wrapper to unregister_con_driver. It will only
4093  * work if driver is fully unbound.
4094  */
4095 void give_up_console(const struct consw *csw)
4096 {
4097         console_lock();
4098         do_unregister_con_driver(csw);
4099         console_unlock();
4100 }
4101
4102 static int __init vtconsole_class_init(void)
4103 {
4104         int i;
4105
4106         vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4107         if (IS_ERR(vtconsole_class)) {
4108                 pr_warn("Unable to create vt console class; errno = %ld\n",
4109                         PTR_ERR(vtconsole_class));
4110                 vtconsole_class = NULL;
4111         }
4112
4113         /* Add system drivers to sysfs */
4114         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4115                 struct con_driver *con = &registered_con_driver[i];
4116
4117                 if (con->con && !con->dev) {
4118                         con->dev =
4119                                 device_create_with_groups(vtconsole_class, NULL,
4120                                                           MKDEV(0, con->node),
4121                                                           con, con_dev_groups,
4122                                                           "vtcon%i", con->node);
4123
4124                         if (IS_ERR(con->dev)) {
4125                                 pr_warn("Unable to create device for %s; errno = %ld\n",
4126                                         con->desc, PTR_ERR(con->dev));
4127                                 con->dev = NULL;
4128                         } else {
4129                                 vtconsole_init_device(con);
4130                         }
4131                 }
4132         }
4133
4134         return 0;
4135 }
4136 postcore_initcall(vtconsole_class_init);
4137
4138 #endif
4139
4140 /*
4141  *      Screen blanking
4142  */
4143
4144 static int set_vesa_blanking(char __user *p)
4145 {
4146         unsigned int mode;
4147
4148         if (get_user(mode, p + 1))
4149                 return -EFAULT;
4150
4151         vesa_blank_mode = (mode < 4) ? mode : 0;
4152         return 0;
4153 }
4154
4155 void do_blank_screen(int entering_gfx)
4156 {
4157         struct vc_data *vc = vc_cons[fg_console].d;
4158         int i;
4159
4160         WARN_CONSOLE_UNLOCKED();
4161
4162         if (console_blanked) {
4163                 if (blank_state == blank_vesa_wait) {
4164                         blank_state = blank_off;
4165                         vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4166                 }
4167                 return;
4168         }
4169
4170         /* entering graphics mode? */
4171         if (entering_gfx) {
4172                 hide_cursor(vc);
4173                 save_screen(vc);
4174                 vc->vc_sw->con_blank(vc, -1, 1);
4175                 console_blanked = fg_console + 1;
4176                 blank_state = blank_off;
4177                 set_origin(vc);
4178                 return;
4179         }
4180
4181         if (blank_state != blank_normal_wait)
4182                 return;
4183         blank_state = blank_off;
4184
4185         /* don't blank graphics */
4186         if (vc->vc_mode != KD_TEXT) {
4187                 console_blanked = fg_console + 1;
4188                 return;
4189         }
4190
4191         hide_cursor(vc);
4192         del_timer_sync(&console_timer);
4193         blank_timer_expired = 0;
4194
4195         save_screen(vc);
4196         /* In case we need to reset origin, blanking hook returns 1 */
4197         i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4198         console_blanked = fg_console + 1;
4199         if (i)
4200                 set_origin(vc);
4201
4202         if (console_blank_hook && console_blank_hook(1))
4203                 return;
4204
4205         if (vesa_off_interval && vesa_blank_mode) {
4206                 blank_state = blank_vesa_wait;
4207                 mod_timer(&console_timer, jiffies + vesa_off_interval);
4208         }
4209         vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4210 }
4211 EXPORT_SYMBOL(do_blank_screen);
4212
4213 /*
4214  * Called by timer as well as from vt_console_driver
4215  */
4216 void do_unblank_screen(int leaving_gfx)
4217 {
4218         struct vc_data *vc;
4219
4220         /* This should now always be called from a "sane" (read: can schedule)
4221          * context for the sake of the low level drivers, except in the special
4222          * case of oops_in_progress
4223          */
4224         if (!oops_in_progress)
4225                 might_sleep();
4226
4227         WARN_CONSOLE_UNLOCKED();
4228
4229         ignore_poke = 0;
4230         if (!console_blanked)
4231                 return;
4232         if (!vc_cons_allocated(fg_console)) {
4233                 /* impossible */
4234                 pr_warn("unblank_screen: tty %d not allocated ??\n",
4235                         fg_console + 1);
4236                 return;
4237         }
4238         vc = vc_cons[fg_console].d;
4239         if (vc->vc_mode != KD_TEXT)
4240                 return; /* but leave console_blanked != 0 */
4241
4242         if (blankinterval) {
4243                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4244                 blank_state = blank_normal_wait;
4245         }
4246
4247         console_blanked = 0;
4248         if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4249                 /* Low-level driver cannot restore -> do it ourselves */
4250                 update_screen(vc);
4251         if (console_blank_hook)
4252                 console_blank_hook(0);
4253         set_palette(vc);
4254         set_cursor(vc);
4255         vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4256 }
4257 EXPORT_SYMBOL(do_unblank_screen);
4258
4259 /*
4260  * This is called by the outside world to cause a forced unblank, mostly for
4261  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4262  * call it with 1 as an argument and so force a mode restore... that may kill
4263  * X or at least garbage the screen but would also make the Oops visible...
4264  */
4265 void unblank_screen(void)
4266 {
4267         do_unblank_screen(0);
4268 }
4269
4270 /*
4271  * We defer the timer blanking to work queue so it can take the console mutex
4272  * (console operations can still happen at irq time, but only from printk which
4273  * has the console mutex. Not perfect yet, but better than no locking
4274  */
4275 static void blank_screen_t(struct timer_list *unused)
4276 {
4277         blank_timer_expired = 1;
4278         schedule_work(&console_work);
4279 }
4280
4281 void poke_blanked_console(void)
4282 {
4283         WARN_CONSOLE_UNLOCKED();
4284
4285         /* Add this so we quickly catch whoever might call us in a non
4286          * safe context. Nowadays, unblank_screen() isn't to be called in
4287          * atomic contexts and is allowed to schedule (with the special case
4288          * of oops_in_progress, but that isn't of any concern for this
4289          * function. --BenH.
4290          */
4291         might_sleep();
4292
4293         /* This isn't perfectly race free, but a race here would be mostly harmless,
4294          * at worse, we'll do a spurrious blank and it's unlikely
4295          */
4296         del_timer(&console_timer);
4297         blank_timer_expired = 0;
4298
4299         if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4300                 return;
4301         if (console_blanked)
4302                 unblank_screen();
4303         else if (blankinterval) {
4304                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4305                 blank_state = blank_normal_wait;
4306         }
4307 }
4308
4309 /*
4310  *      Palettes
4311  */
4312
4313 static void set_palette(struct vc_data *vc)
4314 {
4315         WARN_CONSOLE_UNLOCKED();
4316
4317         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4318                 vc->vc_sw->con_set_palette(vc, color_table);
4319 }
4320
4321 /*
4322  * Load palette into the DAC registers. arg points to a colour
4323  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4324  */
4325
4326 int con_set_cmap(unsigned char __user *arg)
4327 {
4328         int i, j, k;
4329         unsigned char colormap[3*16];
4330
4331         if (copy_from_user(colormap, arg, sizeof(colormap)))
4332                 return -EFAULT;
4333
4334         console_lock();
4335         for (i = k = 0; i < 16; i++) {
4336                 default_red[i] = colormap[k++];
4337                 default_grn[i] = colormap[k++];
4338                 default_blu[i] = colormap[k++];
4339         }
4340         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4341                 if (!vc_cons_allocated(i))
4342                         continue;
4343                 for (j = k = 0; j < 16; j++) {
4344                         vc_cons[i].d->vc_palette[k++] = default_red[j];
4345                         vc_cons[i].d->vc_palette[k++] = default_grn[j];
4346                         vc_cons[i].d->vc_palette[k++] = default_blu[j];
4347                 }
4348                 set_palette(vc_cons[i].d);
4349         }
4350         console_unlock();
4351
4352         return 0;
4353 }
4354
4355 int con_get_cmap(unsigned char __user *arg)
4356 {
4357         int i, k;
4358         unsigned char colormap[3*16];
4359
4360         console_lock();
4361         for (i = k = 0; i < 16; i++) {
4362                 colormap[k++] = default_red[i];
4363                 colormap[k++] = default_grn[i];
4364                 colormap[k++] = default_blu[i];
4365         }
4366         console_unlock();
4367
4368         if (copy_to_user(arg, colormap, sizeof(colormap)))
4369                 return -EFAULT;
4370
4371         return 0;
4372 }
4373
4374 void reset_palette(struct vc_data *vc)
4375 {
4376         int j, k;
4377         for (j=k=0; j<16; j++) {
4378                 vc->vc_palette[k++] = default_red[j];
4379                 vc->vc_palette[k++] = default_grn[j];
4380                 vc->vc_palette[k++] = default_blu[j];
4381         }
4382         set_palette(vc);
4383 }
4384
4385 /*
4386  *  Font switching
4387  *
4388  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4389  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4390  *  depending on width) reserved for each character which is kinda wasty, but
4391  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4392  *  is up to the actual low-level console-driver convert data into its favorite
4393  *  format (maybe we should add a `fontoffset' field to the `display'
4394  *  structure so we won't have to convert the fontdata all the time.
4395  *  /Jes
4396  */
4397
4398 #define max_font_size 65536
4399
4400 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4401 {
4402         struct console_font font;
4403         int rc = -EINVAL;
4404         int c;
4405
4406         if (op->data) {
4407                 font.data = kmalloc(max_font_size, GFP_KERNEL);
4408                 if (!font.data)
4409                         return -ENOMEM;
4410         } else
4411                 font.data = NULL;
4412
4413         console_lock();
4414         if (vc->vc_mode != KD_TEXT)
4415                 rc = -EINVAL;
4416         else if (vc->vc_sw->con_font_get)
4417                 rc = vc->vc_sw->con_font_get(vc, &font);
4418         else
4419                 rc = -ENOSYS;
4420         console_unlock();
4421
4422         if (rc)
4423                 goto out;
4424
4425         c = (font.width+7)/8 * 32 * font.charcount;
4426
4427         if (op->data && font.charcount > op->charcount)
4428                 rc = -ENOSPC;
4429         if (!(op->flags & KD_FONT_FLAG_OLD)) {
4430                 if (font.width > op->width || font.height > op->height)
4431                         rc = -ENOSPC;
4432         } else {
4433                 if (font.width != 8)
4434                         rc = -EIO;
4435                 else if ((op->height && font.height > op->height) ||
4436                          font.height > 32)
4437                         rc = -ENOSPC;
4438         }
4439         if (rc)
4440                 goto out;
4441
4442         op->height = font.height;
4443         op->width = font.width;
4444         op->charcount = font.charcount;
4445
4446         if (op->data && copy_to_user(op->data, font.data, c))
4447                 rc = -EFAULT;
4448
4449 out:
4450         kfree(font.data);
4451         return rc;
4452 }
4453
4454 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4455 {
4456         struct console_font font;
4457         int rc = -EINVAL;
4458         int size;
4459
4460         if (vc->vc_mode != KD_TEXT)
4461                 return -EINVAL;
4462         if (!op->data)
4463                 return -EINVAL;
4464         if (op->charcount > 512)
4465                 return -EINVAL;
4466         if (op->width <= 0 || op->width > 32 || op->height > 32)
4467                 return -EINVAL;
4468         size = (op->width+7)/8 * 32 * op->charcount;
4469         if (size > max_font_size)
4470                 return -ENOSPC;
4471
4472         font.data = memdup_user(op->data, size);
4473         if (IS_ERR(font.data))
4474                 return PTR_ERR(font.data);
4475
4476         if (!op->height) {              /* Need to guess font height [compat] */
4477                 int h, i;
4478                 u8 *charmap = font.data;
4479
4480                 /*
4481                  * If from KDFONTOP ioctl, don't allow things which can be done
4482                  * in userland,so that we can get rid of this soon
4483                  */
4484                 if (!(op->flags & KD_FONT_FLAG_OLD)) {
4485                         kfree(font.data);
4486                         return -EINVAL;
4487                 }
4488
4489                 for (h = 32; h > 0; h--)
4490                         for (i = 0; i < op->charcount; i++)
4491                                 if (charmap[32*i+h-1])
4492                                         goto nonzero;
4493
4494                 kfree(font.data);
4495                 return -EINVAL;
4496
4497         nonzero:
4498                 op->height = h;
4499         }
4500
4501         font.charcount = op->charcount;
4502         font.width = op->width;
4503         font.height = op->height;
4504
4505         console_lock();
4506         if (vc->vc_mode != KD_TEXT)
4507                 rc = -EINVAL;
4508         else if (vc->vc_sw->con_font_set)
4509                 rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4510         else
4511                 rc = -ENOSYS;
4512         console_unlock();
4513         kfree(font.data);
4514         return rc;
4515 }
4516
4517 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4518 {
4519         struct console_font font = {.width = op->width, .height = op->height};
4520         char name[MAX_FONT_NAME];
4521         char *s = name;
4522         int rc;
4523
4524
4525         if (!op->data)
4526                 s = NULL;
4527         else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4528                 return -EFAULT;
4529         else
4530                 name[MAX_FONT_NAME - 1] = 0;
4531
4532         console_lock();
4533         if (vc->vc_mode != KD_TEXT) {
4534                 console_unlock();
4535                 return -EINVAL;
4536         }
4537         if (vc->vc_sw->con_font_default)
4538                 rc = vc->vc_sw->con_font_default(vc, &font, s);
4539         else
4540                 rc = -ENOSYS;
4541         console_unlock();
4542         if (!rc) {
4543                 op->width = font.width;
4544                 op->height = font.height;
4545         }
4546         return rc;
4547 }
4548
4549 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4550 {
4551         int con = op->height;
4552         int rc;
4553
4554
4555         console_lock();
4556         if (vc->vc_mode != KD_TEXT)
4557                 rc = -EINVAL;
4558         else if (!vc->vc_sw->con_font_copy)
4559                 rc = -ENOSYS;
4560         else if (con < 0 || !vc_cons_allocated(con))
4561                 rc = -ENOTTY;
4562         else if (con == vc->vc_num)     /* nothing to do */
4563                 rc = 0;
4564         else
4565                 rc = vc->vc_sw->con_font_copy(vc, con);
4566         console_unlock();
4567         return rc;
4568 }
4569
4570 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4571 {
4572         switch (op->op) {
4573         case KD_FONT_OP_SET:
4574                 return con_font_set(vc, op);
4575         case KD_FONT_OP_GET:
4576                 return con_font_get(vc, op);
4577         case KD_FONT_OP_SET_DEFAULT:
4578                 return con_font_default(vc, op);
4579         case KD_FONT_OP_COPY:
4580                 return con_font_copy(vc, op);
4581         }
4582         return -ENOSYS;
4583 }
4584
4585 /*
4586  *      Interface exported to selection and vcs.
4587  */
4588
4589 /* used by selection */
4590 u16 screen_glyph(struct vc_data *vc, int offset)
4591 {
4592         u16 w = scr_readw(screenpos(vc, offset, 1));
4593         u16 c = w & 0xff;
4594
4595         if (w & vc->vc_hi_font_mask)
4596                 c |= 0x100;
4597         return c;
4598 }
4599 EXPORT_SYMBOL_GPL(screen_glyph);
4600
4601 u32 screen_glyph_unicode(struct vc_data *vc, int n)
4602 {
4603         struct uni_screen *uniscr = get_vc_uniscr(vc);
4604
4605         if (uniscr)
4606                 return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4607         return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4608 }
4609 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4610
4611 /* used by vcs - note the word offset */
4612 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4613 {
4614         return screenpos(vc, 2 * w_offset, viewed);
4615 }
4616 EXPORT_SYMBOL_GPL(screen_pos);
4617
4618 void getconsxy(struct vc_data *vc, unsigned char *p)
4619 {
4620         /* clamp values if they don't fit */
4621         p[0] = min(vc->vc_x, 0xFFu);
4622         p[1] = min(vc->vc_y, 0xFFu);
4623 }
4624
4625 void putconsxy(struct vc_data *vc, unsigned char *p)
4626 {
4627         hide_cursor(vc);
4628         gotoxy(vc, p[0], p[1]);
4629         set_cursor(vc);
4630 }
4631
4632 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4633 {
4634         if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4635                 return softcursor_original;
4636         return scr_readw(org);
4637 }
4638
4639 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4640 {
4641         scr_writew(val, org);
4642         if ((unsigned long)org == vc->vc_pos) {
4643                 softcursor_original = -1;
4644                 add_softcursor(vc);
4645         }
4646 }
4647
4648 void vcs_scr_updated(struct vc_data *vc)
4649 {
4650         notify_update(vc);
4651 }
4652
4653 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4654                 unsigned int rolled_over, void *base, unsigned int size)
4655 {
4656         unsigned long ubase = (unsigned long)base;
4657         ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4658         ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4659         ptrdiff_t origin = (void *)c->vc_origin - base;
4660         int margin = c->vc_size_row * 4;
4661         int from, wrap, from_off, avail;
4662
4663         /* Turn scrollback off */
4664         if (!lines) {
4665                 c->vc_visible_origin = c->vc_origin;
4666                 return;
4667         }
4668
4669         /* Do we have already enough to allow jumping from 0 to the end? */
4670         if (rolled_over > scr_end + margin) {
4671                 from = scr_end;
4672                 wrap = rolled_over + c->vc_size_row;
4673         } else {
4674                 from = 0;
4675                 wrap = size;
4676         }
4677
4678         from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4679         avail = (origin - from + wrap) % wrap;
4680
4681         /* Only a little piece would be left? Show all incl. the piece! */
4682         if (avail < 2 * margin)
4683                 margin = 0;
4684         if (from_off < margin)
4685                 from_off = 0;
4686         if (from_off > avail - margin)
4687                 from_off = avail;
4688
4689         c->vc_visible_origin = ubase + (from + from_off) % wrap;
4690 }
4691 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4692
4693 /*
4694  *      Visible symbols for modules
4695  */
4696
4697 EXPORT_SYMBOL(color_table);
4698 EXPORT_SYMBOL(default_red);
4699 EXPORT_SYMBOL(default_grn);
4700 EXPORT_SYMBOL(default_blu);
4701 EXPORT_SYMBOL(update_region);
4702 EXPORT_SYMBOL(redraw_screen);
4703 EXPORT_SYMBOL(vc_resize);
4704 EXPORT_SYMBOL(fg_console);
4705 EXPORT_SYMBOL(console_blank_hook);
4706 EXPORT_SYMBOL(console_blanked);
4707 EXPORT_SYMBOL(vc_cons);
4708 EXPORT_SYMBOL(global_cursor_default);
4709 #ifndef VT_SINGLE_DRIVER
4710 EXPORT_SYMBOL(give_up_console);
4711 #endif