drivers/tty/vt/vt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright (C) 1991, 1992  Linus Torvalds
   4  */
   5
   6 /*
   7  * Hopefully this will be a rather complete VT102 implementation.
   8  *
   9  * Beeping thanks to John T Kohl.
  10  *
  11  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
  12  *   Chars, and VT100 enhancements by Peter MacDonald.
  13  *
  14  * Copy and paste function by Andrew Haylett,
  15  *   some enhancements by Alessandro Rubini.
  16  *
  17  * Code to check for different video-cards mostly by Galen Hunt,
  18  * <g-hunt@ee.utah.edu>
  19  *
  20  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
  21  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
  22  *
  23  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
  24  * Resizing of consoles, aeb, 940926
  25  *
  26  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
  27  * <poe@daimi.aau.dk>
  28  *
  29  * User-defined bell sound, new setterm control sequences and printk
  30  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
  31  *
  32  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
  33  *
  34  * Merge with the abstract console driver by Geert Uytterhoeven
  35  * <geert@linux-m68k.org>, Jan 1997.
  36  *
  37  *   Original m68k console driver modifications by
  38  *
  39  *     - Arno Griffioen <arno@usn.nl>
  40  *     - David Carter <carter@cs.bris.ac.uk>
  41  *
  42  *   The abstract console driver provides a generic interface for a text
  43  *   console. It supports VGA text mode, frame buffer based graphical consoles
  44  *   and special graphics processors that are only accessible through some
  45  *   registers (e.g. a TMS340x0 GSP).
  46  *
  47  *   The interface to the hardware is specified using a special structure
  48  *   (struct consw) which contains function pointers to console operations
  49  *   (see <linux/console.h> for more information).
  50  *
  51  * Support for changeable cursor shape
  52  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
  53  *
  54  * Ported to i386 and con_scrolldelta fixed
  55  * by Emmanuel Marty <core@ggi-project.org>, April 1998
  56  *
  57  * Resurrected character buffers in videoram plus lots of other trickery
  58  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
  59  *
  60  * Removed old-style timers, introduced console_timer, made timer
  61  * deletion SMP-safe.  17Jun00, Andrew Morton
  62  *
  63  * Removed console_lock, enabled interrupts across all console operations
  64  * 13 March 2001, Andrew Morton
  65  *
  66  * Fixed UTF-8 mode so alternate charset modes always work according
  67  * to control sequences interpreted in do_con_trol function
  68  * preserving backward VT100 semigraphics compatibility,
  69  * malformed UTF sequences represented as sequences of replacement glyphs,
  70  * original codes or '?' as a last resort if replacement glyph is undefined
  71  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
  72  */
  73
  74 #include <linux/module.h>
  75 #include <linux/types.h>
  76 #include <linux/sched/signal.h>
  77 #include <linux/tty.h>
  78 #include <linux/tty_flip.h>
  79 #include <linux/kernel.h>
  80 #include <linux/string.h>
  81 #include <linux/errno.h>
  82 #include <linux/kd.h>
  83 #include <linux/slab.h>
  84 #include <linux/vmalloc.h>
  85 #include <linux/major.h>
  86 #include <linux/mm.h>
  87 #include <linux/console.h>
  88 #include <linux/init.h>
  89 #include <linux/mutex.h>
  90 #include <linux/vt_kern.h>
  91 #include <linux/selection.h>
  92 #include <linux/tiocl.h>
  93 #include <linux/kbd_kern.h>
  94 #include <linux/consolemap.h>
  95 #include <linux/timer.h>
  96 #include <linux/interrupt.h>
  97 #include <linux/workqueue.h>
  98 #include <linux/pm.h>
  99 #include <linux/font.h>
 100 #include <linux/bitops.h>
 101 #include <linux/notifier.h>
 102 #include <linux/device.h>
 103 #include <linux/io.h>
 104 #include <linux/uaccess.h>
 105 #include <linux/kdb.h>
 106 #include <linux/ctype.h>
 107 #include <linux/bsearch.h>
 108 #include <linux/gcd.h>
 109
 110 #define MAX_NR_CON_DRIVER 16
 111
 112 #define CON_DRIVER_FLAG_MODULE 1
 113 #define CON_DRIVER_FLAG_INIT   2
 114 #define CON_DRIVER_FLAG_ATTR   4
 115 #define CON_DRIVER_FLAG_ZOMBIE 8
 116
 117 struct con_driver {
 118         const struct consw *con;
 119         const char *desc;
 120         struct device *dev;
 121         int node;
 122         int first;
 123         int last;
 124         int flag;
 125 };
 126
 127 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
 128 const struct consw *conswitchp;
 129
 130 /* A bitmap for codes <32. A bit of 1 indicates that the code
 131  * corresponding to that bit number invokes some special action
 132  * (such as cursor movement) and should not be displayed as a
 133  * glyph unless the disp_ctrl mode is explicitly enabled.
 134  */
 135 #define CTRL_ACTION 0x0d00ff81
 136 #define CTRL_ALWAYS 0x0800f501  /* Cannot be overridden by disp_ctrl */
 137
 138 /*
 139  * Here is the default bell parameters: 750HZ, 1/8th of a second
 140  */
 141 #define DEFAULT_BELL_PITCH      750
 142 #define DEFAULT_BELL_DURATION   (HZ/8)
 143 #define DEFAULT_CURSOR_BLINK_MS 200
 144
 145 struct vc vc_cons [MAX_NR_CONSOLES];
 146
 147 #ifndef VT_SINGLE_DRIVER
 148 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
 149 #endif
 150
 151 static int con_open(struct tty_struct *, struct file *);
 152 static void vc_init(struct vc_data *vc, unsigned int rows,
 153                     unsigned int cols, int do_clear);
 154 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
 155 static void save_cur(struct vc_data *vc);
 156 static void reset_terminal(struct vc_data *vc, int do_clear);
 157 static void con_flush_chars(struct tty_struct *tty);
 158 static int set_vesa_blanking(char __user *p);
 159 static void set_cursor(struct vc_data *vc);
 160 static void hide_cursor(struct vc_data *vc);
 161 static void console_callback(struct work_struct *ignored);
 162 static void con_driver_unregister_callback(struct work_struct *ignored);
 163 static void blank_screen_t(struct timer_list *unused);
 164 static void set_palette(struct vc_data *vc);
 165
 166 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 167
 168 static int printable;           /* Is console ready for printing? */
 169 int default_utf8 = true;
 170 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 171 int global_cursor_default = -1;
 172 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
 173
 174 static int cur_default = CUR_DEFAULT;
 175 module_param(cur_default, int, S_IRUGO | S_IWUSR);
 176
 177 /*
 178  * ignore_poke: don't unblank the screen when things are typed.  This is
 179  * mainly for the privacy of braille terminal users.
 180  */
 181 static int ignore_poke;
 182
 183 int do_poke_blanked_console;
 184 int console_blanked;
 185
 186 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
 187 static int vesa_off_interval;
 188 static int blankinterval;
 189 core_param(consoleblank, blankinterval, int, 0444);
 190
 191 static DECLARE_WORK(console_work, console_callback);
 192 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
 193
 194 /*
 195  * fg_console is the current virtual console,
 196  * last_console is the last used one,
 197  * want_console is the console we want to switch to,
 198  * saved_* variants are for save/restore around kernel debugger enter/leave
 199  */
 200 int fg_console;
 201 int last_console;
 202 int want_console = -1;
 203 static int saved_fg_console;
 204 static int saved_last_console;
 205 static int saved_want_console;
 206 static int saved_vc_mode;
 207 static int saved_console_blanked;
 208
 209 /*
 210  * For each existing display, we have a pointer to console currently visible
 211  * on that display, allowing consoles other than fg_console to be refreshed
 212  * appropriately. Unless the low-level driver supplies its own display_fg
 213  * variable, we use this one for the "master display".
 214  */
 215 static struct vc_data *master_display_fg;
 216
 217 /*
 218  * Unfortunately, we need to delay tty echo when we're currently writing to the
 219  * console since the code is (and always was) not re-entrant, so we schedule
 220  * all flip requests to process context with schedule-task() and run it from
 221  * console_callback().
 222  */
 223
 224 /*
 225  * For the same reason, we defer scrollback to the console callback.
 226  */
 227 static int scrollback_delta;
 228
 229 /*
 230  * Hook so that the power management routines can (un)blank
 231  * the console on our behalf.
 232  */
 233 int (*console_blank_hook)(int);
 234
 235 static DEFINE_TIMER(console_timer, blank_screen_t);
 236 static int blank_state;
 237 static int blank_timer_expired;
 238 enum {
 239         blank_off = 0,
 240         blank_normal_wait,
 241         blank_vesa_wait,
 242 };
 243
 244 /*
 245  * /sys/class/tty/tty0/
 246  *
 247  * the attribute 'active' contains the name of the current vc
 248  * console and it supports poll() to detect vc switches
 249  */
 250 static struct device *tty0dev;
 251
 252 /*
 253  * Notifier list for console events.
 254  */
 255 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
 256
 257 int register_vt_notifier(struct notifier_block *nb)
 258 {
 259         return atomic_notifier_chain_register(&vt_notifier_list, nb);
 260 }
 261 EXPORT_SYMBOL_GPL(register_vt_notifier);
 262
 263 int unregister_vt_notifier(struct notifier_block *nb)
 264 {
 265         return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
 266 }
 267 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
 268
 269 static void notify_write(struct vc_data *vc, unsigned int unicode)
 270 {
 271         struct vt_notifier_param param = { .vc = vc, .c = unicode };
 272         atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
 273 }
 274
 275 static void notify_update(struct vc_data *vc)
 276 {
 277         struct vt_notifier_param param = { .vc = vc };
 278         atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
 279 }
 280 /*
 281  *      Low-Level Functions
 282  */
 283
 284 static inline bool con_is_fg(const struct vc_data *vc)
 285 {
 286         return vc->vc_num == fg_console;
 287 }
 288
 289 static inline bool con_should_update(const struct vc_data *vc)
 290 {
 291         return con_is_visible(vc) && !console_blanked;
 292 }
 293
 294 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
 295 {
 296         unsigned short *p;
 297
 298         if (!viewed)
 299                 p = (unsigned short *)(vc->vc_origin + offset);
 300         else if (!vc->vc_sw->con_screen_pos)
 301                 p = (unsigned short *)(vc->vc_visible_origin + offset);
 302         else
 303                 p = vc->vc_sw->con_screen_pos(vc, offset);
 304         return p;
 305 }
 306
 307 /* Called  from the keyboard irq path.. */
 308 static inline void scrolldelta(int lines)
 309 {
 310         /* FIXME */
 311         /* scrolldelta needs some kind of consistency lock, but the BKL was
 312            and still is not protecting versus the scheduled back end */
 313         scrollback_delta += lines;
 314         schedule_console_callback();
 315 }
 316
 317 void schedule_console_callback(void)
 318 {
 319         schedule_work(&console_work);
 320 }
 321
 322 /*
 323  * Code to manage unicode-based screen buffers
 324  */
 325
 326 #ifdef NO_VC_UNI_SCREEN
 327 /* this disables and optimizes related code away at compile time */
 328 #define get_vc_uniscr(vc) NULL
 329 #else
 330 #define get_vc_uniscr(vc) vc->vc_uni_screen
 331 #endif
 332
 333 #define VC_UNI_SCREEN_DEBUG 0
 334
 335 typedef uint32_t char32_t;
 336
 337 /*
 338  * Our screen buffer is preceded by an array of line pointers so that
 339  * scrolling only implies some pointer shuffling.
 340  */
 341 struct uni_screen {
 342         char32_t *lines[0];
 343 };
 344
 345 static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
 346 {
 347         struct uni_screen *uniscr;
 348         void *p;
 349         unsigned int memsize, i;
 350
 351         /* allocate everything in one go */
 352         memsize = cols * rows * sizeof(char32_t);
 353         memsize += rows * sizeof(char32_t *);
 354         p = vmalloc(memsize);
 355         if (!p)
 356                 return NULL;
 357
 358         /* initial line pointers */
 359         uniscr = p;
 360         p = uniscr->lines + rows;
 361         for (i = 0; i < rows; i++) {
 362                 uniscr->lines[i] = p;
 363                 p += cols * sizeof(char32_t);
 364         }
 365         return uniscr;
 366 }
 367
 368 static void vc_uniscr_free(struct uni_screen *uniscr)
 369 {
 370         vfree(uniscr);
 371 }
 372
 373 static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
 374 {
 375         vc_uniscr_free(vc->vc_uni_screen);
 376         vc->vc_uni_screen = new_uniscr;
 377 }
 378
 379 static void vc_uniscr_putc(struct vc_data *vc, char32_t uc)
 380 {
 381         struct uni_screen *uniscr = get_vc_uniscr(vc);
 382
 383         if (uniscr)
 384                 uniscr->lines[vc->state.y][vc->state.x] = uc;
 385 }
 386
 387 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
 388 {
 389         struct uni_screen *uniscr = get_vc_uniscr(vc);
 390
 391         if (uniscr) {
 392                 char32_t *ln = uniscr->lines[vc->state.y];
 393                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 394
 395                 memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
 396                 memset32(&ln[x], ' ', nr);
 397         }
 398 }
 399
 400 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
 401 {
 402         struct uni_screen *uniscr = get_vc_uniscr(vc);
 403
 404         if (uniscr) {
 405                 char32_t *ln = uniscr->lines[vc->state.y];
 406                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 407
 408                 memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
 409                 memset32(&ln[cols - nr], ' ', nr);
 410         }
 411 }
 412
 413 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
 414                                  unsigned int nr)
 415 {
 416         struct uni_screen *uniscr = get_vc_uniscr(vc);
 417
 418         if (uniscr) {
 419                 char32_t *ln = uniscr->lines[vc->state.y];
 420
 421                 memset32(&ln[x], ' ', nr);
 422         }
 423 }
 424
 425 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
 426                                   unsigned int nr)
 427 {
 428         struct uni_screen *uniscr = get_vc_uniscr(vc);
 429
 430         if (uniscr) {
 431                 unsigned int cols = vc->vc_cols;
 432
 433                 while (nr--)
 434                         memset32(uniscr->lines[y++], ' ', cols);
 435         }
 436 }
 437
 438 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 439                              enum con_scroll dir, unsigned int nr)
 440 {
 441         struct uni_screen *uniscr = get_vc_uniscr(vc);
 442
 443         if (uniscr) {
 444                 unsigned int i, j, k, sz, d, clear;
 445
 446                 sz = b - t;
 447                 clear = b - nr;
 448                 d = nr;
 449                 if (dir == SM_DOWN) {
 450                         clear = t;
 451                         d = sz - nr;
 452                 }
 453                 for (i = 0; i < gcd(d, sz); i++) {
 454                         char32_t *tmp = uniscr->lines[t + i];
 455                         j = i;
 456                         while (1) {
 457                                 k = j + d;
 458                                 if (k >= sz)
 459                                         k -= sz;
 460                                 if (k == i)
 461                                         break;
 462                                 uniscr->lines[t + j] = uniscr->lines[t + k];
 463                                 j = k;
 464                         }
 465                         uniscr->lines[t + j] = tmp;
 466                 }
 467                 vc_uniscr_clear_lines(vc, clear, nr);
 468         }
 469 }
 470
 471 static void vc_uniscr_copy_area(struct uni_screen *dst,
 472                                 unsigned int dst_cols,
 473                                 unsigned int dst_rows,
 474                                 struct uni_screen *src,
 475                                 unsigned int src_cols,
 476                                 unsigned int src_top_row,
 477                                 unsigned int src_bot_row)
 478 {
 479         unsigned int dst_row = 0;
 480
 481         if (!dst)
 482                 return;
 483
 484         while (src_top_row < src_bot_row) {
 485                 char32_t *src_line = src->lines[src_top_row];
 486                 char32_t *dst_line = dst->lines[dst_row];
 487
 488                 memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
 489                 if (dst_cols - src_cols)
 490                         memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
 491                 src_top_row++;
 492                 dst_row++;
 493         }
 494         while (dst_row < dst_rows) {
 495                 char32_t *dst_line = dst->lines[dst_row];
 496
 497                 memset32(dst_line, ' ', dst_cols);
 498                 dst_row++;
 499         }
 500 }
 501
 502 /*
 503  * Called from vcs_read() to make sure unicode screen retrieval is possible.
 504  * This will initialize the unicode screen buffer if not already done.
 505  * This returns 0 if OK, or a negative error code otherwise.
 506  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
 507  */
 508 int vc_uniscr_check(struct vc_data *vc)
 509 {
 510         struct uni_screen *uniscr;
 511         unsigned short *p;
 512         int x, y, mask;
 513
 514         if (__is_defined(NO_VC_UNI_SCREEN))
 515                 return -EOPNOTSUPP;
 516
 517         WARN_CONSOLE_UNLOCKED();
 518
 519         if (!vc->vc_utf)
 520                 return -ENODATA;
 521
 522         if (vc->vc_uni_screen)
 523                 return 0;
 524
 525         uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
 526         if (!uniscr)
 527                 return -ENOMEM;
 528
 529         /*
 530          * Let's populate it initially with (imperfect) reverse translation.
 531          * This is the next best thing we can do short of having it enabled
 532          * from the start even when no users rely on this functionality. True
 533          * unicode content will be available after a complete screen refresh.
 534          */
 535         p = (unsigned short *)vc->vc_origin;
 536         mask = vc->vc_hi_font_mask | 0xff;
 537         for (y = 0; y < vc->vc_rows; y++) {
 538                 char32_t *line = uniscr->lines[y];
 539                 for (x = 0; x < vc->vc_cols; x++) {
 540                         u16 glyph = scr_readw(p++) & mask;
 541                         line[x] = inverse_translate(vc, glyph, true);
 542                 }
 543         }
 544
 545         vc->vc_uni_screen = uniscr;
 546         return 0;
 547 }
 548
 549 /*
 550  * Called from vcs_read() to get the unicode data from the screen.
 551  * This must be preceded by a successful call to vc_uniscr_check() once
 552  * the console lock has been taken.
 553  */
 554 void vc_uniscr_copy_line(struct vc_data *vc, void *dest, int viewed,
 555                          unsigned int row, unsigned int col, unsigned int nr)
 556 {
 557         struct uni_screen *uniscr = get_vc_uniscr(vc);
 558         int offset = row * vc->vc_size_row + col * 2;
 559         unsigned long pos;
 560
 561         BUG_ON(!uniscr);
 562
 563         pos = (unsigned long)screenpos(vc, offset, viewed);
 564         if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
 565                 /*
 566                  * Desired position falls in the main screen buffer.
 567                  * However the actual row/col might be different if
 568                  * scrollback is active.
 569                  */
 570                 row = (pos - vc->vc_origin) / vc->vc_size_row;
 571                 col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
 572                 memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t));
 573         } else {
 574                 /*
 575                  * Scrollback is active. For now let's simply backtranslate
 576                  * the screen glyphs until the unicode screen buffer does
 577                  * synchronize with console display drivers for a scrollback
 578                  * buffer of its own.
 579                  */
 580                 u16 *p = (u16 *)pos;
 581                 int mask = vc->vc_hi_font_mask | 0xff;
 582                 char32_t *uni_buf = dest;
 583                 while (nr--) {
 584                         u16 glyph = scr_readw(p++) & mask;
 585                         *uni_buf++ = inverse_translate(vc, glyph, true);
 586                 }
 587         }
 588 }
 589
 590 /* this is for validation and debugging only */
 591 static void vc_uniscr_debug_check(struct vc_data *vc)
 592 {
 593         struct uni_screen *uniscr = get_vc_uniscr(vc);
 594         unsigned short *p;
 595         int x, y, mask;
 596
 597         if (!VC_UNI_SCREEN_DEBUG || !uniscr)
 598                 return;
 599
 600         WARN_CONSOLE_UNLOCKED();
 601
 602         /*
 603          * Make sure our unicode screen translates into the same glyphs
 604          * as the actual screen. This is brutal indeed.
 605          */
 606         p = (unsigned short *)vc->vc_origin;
 607         mask = vc->vc_hi_font_mask | 0xff;
 608         for (y = 0; y < vc->vc_rows; y++) {
 609                 char32_t *line = uniscr->lines[y];
 610                 for (x = 0; x < vc->vc_cols; x++) {
 611                         u16 glyph = scr_readw(p++) & mask;
 612                         char32_t uc = line[x];
 613                         int tc = conv_uni_to_pc(vc, uc);
 614                         if (tc == -4)
 615                                 tc = conv_uni_to_pc(vc, 0xfffd);
 616                         if (tc == -4)
 617                                 tc = conv_uni_to_pc(vc, '?');
 618                         if (tc != glyph)
 619                                 pr_err_ratelimited(
 620                                         "%s: mismatch at %d,%d: glyph=%#x tc=%#x\n",
 621                                         __func__, x, y, glyph, tc);
 622                 }
 623         }
 624 }
 625
 626
 627 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 628                 enum con_scroll dir, unsigned int nr)
 629 {
 630         u16 *clear, *d, *s;
 631
 632         if (t + nr >= b)
 633                 nr = b - t - 1;
 634         if (b > vc->vc_rows || t >= b || nr < 1)
 635                 return;
 636         vc_uniscr_scroll(vc, t, b, dir, nr);
 637         if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
 638                 return;
 639
 640         s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
 641         d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
 642
 643         if (dir == SM_UP) {
 644                 clear = s + (b - t - nr) * vc->vc_cols;
 645                 swap(s, d);
 646         }
 647         scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
 648         scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
 649 }
 650
 651 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 652 {
 653         unsigned int xx, yy, offset;
 654         u16 *p;
 655
 656         p = (u16 *) start;
 657         if (!vc->vc_sw->con_getxy) {
 658                 offset = (start - vc->vc_origin) / 2;
 659                 xx = offset % vc->vc_cols;
 660                 yy = offset / vc->vc_cols;
 661         } else {
 662                 int nxx, nyy;
 663                 start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
 664                 xx = nxx; yy = nyy;
 665         }
 666         for(;;) {
 667                 u16 attrib = scr_readw(p) & 0xff00;
 668                 int startx = xx;
 669                 u16 *q = p;
 670                 while (xx < vc->vc_cols && count) {
 671                         if (attrib != (scr_readw(p) & 0xff00)) {
 672                                 if (p > q)
 673                                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 674                                 startx = xx;
 675                                 q = p;
 676                                 attrib = scr_readw(p) & 0xff00;
 677                         }
 678                         p++;
 679                         xx++;
 680                         count--;
 681                 }
 682                 if (p > q)
 683                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 684                 if (!count)
 685                         break;
 686                 xx = 0;
 687                 yy++;
 688                 if (vc->vc_sw->con_getxy) {
 689                         p = (u16 *)start;
 690                         start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
 691                 }
 692         }
 693 }
 694
 695 void update_region(struct vc_data *vc, unsigned long start, int count)
 696 {
 697         WARN_CONSOLE_UNLOCKED();
 698
 699         if (con_should_update(vc)) {
 700                 hide_cursor(vc);
 701                 do_update_region(vc, start, count);
 702                 set_cursor(vc);
 703         }
 704 }
 705
 706 /* Structure of attributes is hardware-dependent */
 707
 708 static u8 build_attr(struct vc_data *vc, u8 _color,
 709                 enum vc_intensity _intensity, bool _blink, bool _underline,
 710                 bool _reverse, bool _italic)
 711 {
 712         if (vc->vc_sw->con_build_attr)
 713                 return vc->vc_sw->con_build_attr(vc, _color, _intensity,
 714                        _blink, _underline, _reverse, _italic);
 715
 716 /*
 717  * ++roman: I completely changed the attribute format for monochrome
 718  * mode (!can_do_color). The formerly used MDA (monochrome display
 719  * adapter) format didn't allow the combination of certain effects.
 720  * Now the attribute is just a bit vector:
 721  *  Bit 0..1: intensity (0..2)
 722  *  Bit 2   : underline
 723  *  Bit 3   : reverse
 724  *  Bit 7   : blink
 725  */
 726         {
 727         u8 a = _color;
 728         if (!vc->vc_can_do_color)
 729                 return _intensity |
 730                        (_italic ? 2 : 0) |
 731                        (_underline ? 4 : 0) |
 732                        (_reverse ? 8 : 0) |
 733                        (_blink ? 0x80 : 0);
 734         if (_italic)
 735                 a = (a & 0xF0) | vc->vc_itcolor;
 736         else if (_underline)
 737                 a = (a & 0xf0) | vc->vc_ulcolor;
 738         else if (_intensity == VCI_HALF_BRIGHT)
 739                 a = (a & 0xf0) | vc->vc_halfcolor;
 740         if (_reverse)
 741                 a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
 742         if (_blink)
 743                 a ^= 0x80;
 744         if (_intensity == VCI_BOLD)
 745                 a ^= 0x08;
 746         if (vc->vc_hi_font_mask == 0x100)
 747                 a <<= 1;
 748         return a;
 749         }
 750 }
 751
 752 static void update_attr(struct vc_data *vc)
 753 {
 754         vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
 755                       vc->state.blink, vc->state.underline,
 756                       vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
 757         vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
 758                                 VCI_NORMAL, vc->state.blink, false,
 759                                 vc->vc_decscnm, false) << 8);
 760 }
 761
 762 /* Note: inverting the screen twice should revert to the original state */
 763 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
 764 {
 765         unsigned short *p;
 766
 767         WARN_CONSOLE_UNLOCKED();
 768
 769         count /= 2;
 770         p = screenpos(vc, offset, viewed);
 771         if (vc->vc_sw->con_invert_region) {
 772                 vc->vc_sw->con_invert_region(vc, p, count);
 773         } else {
 774                 u16 *q = p;
 775                 int cnt = count;
 776                 u16 a;
 777
 778                 if (!vc->vc_can_do_color) {
 779                         while (cnt--) {
 780                             a = scr_readw(q);
 781                             a ^= 0x0800;
 782                             scr_writew(a, q);
 783                             q++;
 784                         }
 785                 } else if (vc->vc_hi_font_mask == 0x100) {
 786                         while (cnt--) {
 787                                 a = scr_readw(q);
 788                                 a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
 789                                 scr_writew(a, q);
 790                                 q++;
 791                         }
 792                 } else {
 793                         while (cnt--) {
 794                                 a = scr_readw(q);
 795                                 a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
 796                                 scr_writew(a, q);
 797                                 q++;
 798                         }
 799                 }
 800         }
 801
 802         if (con_should_update(vc))
 803                 do_update_region(vc, (unsigned long) p, count);
 804         notify_update(vc);
 805 }
 806
 807 /* used by selection: complement pointer position */
 808 void complement_pos(struct vc_data *vc, int offset)
 809 {
 810         static int old_offset = -1;
 811         static unsigned short old;
 812         static unsigned short oldx, oldy;
 813
 814         WARN_CONSOLE_UNLOCKED();
 815
 816         if (old_offset != -1 && old_offset >= 0 &&
 817             old_offset < vc->vc_screenbuf_size) {
 818                 scr_writew(old, screenpos(vc, old_offset, 1));
 819                 if (con_should_update(vc))
 820                         vc->vc_sw->con_putc(vc, old, oldy, oldx);
 821                 notify_update(vc);
 822         }
 823
 824         old_offset = offset;
 825
 826         if (offset != -1 && offset >= 0 &&
 827             offset < vc->vc_screenbuf_size) {
 828                 unsigned short new;
 829                 unsigned short *p;
 830                 p = screenpos(vc, offset, 1);
 831                 old = scr_readw(p);
 832                 new = old ^ vc->vc_complement_mask;
 833                 scr_writew(new, p);
 834                 if (con_should_update(vc)) {
 835                         oldx = (offset >> 1) % vc->vc_cols;
 836                         oldy = (offset >> 1) / vc->vc_cols;
 837                         vc->vc_sw->con_putc(vc, new, oldy, oldx);
 838                 }
 839                 notify_update(vc);
 840         }
 841 }
 842
 843 static void insert_char(struct vc_data *vc, unsigned int nr)
 844 {
 845         unsigned short *p = (unsigned short *) vc->vc_pos;
 846
 847         vc_uniscr_insert(vc, nr);
 848         scr_memmovew(p + nr, p, (vc->vc_cols - vc->state.x - nr) * 2);
 849         scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
 850         vc->vc_need_wrap = 0;
 851         if (con_should_update(vc))
 852                 do_update_region(vc, (unsigned long) p,
 853                         vc->vc_cols - vc->state.x);
 854 }
 855
 856 static void delete_char(struct vc_data *vc, unsigned int nr)
 857 {
 858         unsigned short *p = (unsigned short *) vc->vc_pos;
 859
 860         vc_uniscr_delete(vc, nr);
 861         scr_memcpyw(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
 862         scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
 863                         nr * 2);
 864         vc->vc_need_wrap = 0;
 865         if (con_should_update(vc))
 866                 do_update_region(vc, (unsigned long) p,
 867                         vc->vc_cols - vc->state.x);
 868 }
 869
 870 static int softcursor_original = -1;
 871
 872 static void add_softcursor(struct vc_data *vc)
 873 {
 874         int i = scr_readw((u16 *) vc->vc_pos);
 875         u32 type = vc->vc_cursor_type;
 876
 877         if (! (type & 0x10)) return;
 878         if (softcursor_original != -1) return;
 879         softcursor_original = i;
 880         i |= ((type >> 8) & 0xff00 );
 881         i ^= ((type) & 0xff00 );
 882         if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
 883         if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
 884         scr_writew(i, (u16 *) vc->vc_pos);
 885         if (con_should_update(vc))
 886                 vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
 887 }
 888
 889 static void hide_softcursor(struct vc_data *vc)
 890 {
 891         if (softcursor_original != -1) {
 892                 scr_writew(softcursor_original, (u16 *)vc->vc_pos);
 893                 if (con_should_update(vc))
 894                         vc->vc_sw->con_putc(vc, softcursor_original,
 895                                         vc->state.y, vc->state.x);
 896                 softcursor_original = -1;
 897         }
 898 }
 899
 900 static void hide_cursor(struct vc_data *vc)
 901 {
 902         if (vc_is_sel(vc))
 903                 clear_selection();
 904
 905         vc->vc_sw->con_cursor(vc, CM_ERASE);
 906         hide_softcursor(vc);
 907 }
 908
 909 static void set_cursor(struct vc_data *vc)
 910 {
 911         if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
 912                 return;
 913         if (vc->vc_deccm) {
 914                 if (vc_is_sel(vc))
 915                         clear_selection();
 916                 add_softcursor(vc);
 917                 if ((vc->vc_cursor_type & 0x0f) != 1)
 918                         vc->vc_sw->con_cursor(vc, CM_DRAW);
 919         } else
 920                 hide_cursor(vc);
 921 }
 922
 923 static void set_origin(struct vc_data *vc)
 924 {
 925         WARN_CONSOLE_UNLOCKED();
 926
 927         if (!con_is_visible(vc) ||
 928             !vc->vc_sw->con_set_origin ||
 929             !vc->vc_sw->con_set_origin(vc))
 930                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
 931         vc->vc_visible_origin = vc->vc_origin;
 932         vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
 933         vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->state.y +
 934                 2 * vc->state.x;
 935 }
 936
 937 static void save_screen(struct vc_data *vc)
 938 {
 939         WARN_CONSOLE_UNLOCKED();
 940
 941         if (vc->vc_sw->con_save_screen)
 942                 vc->vc_sw->con_save_screen(vc);
 943 }
 944
 945 static void flush_scrollback(struct vc_data *vc)
 946 {
 947         WARN_CONSOLE_UNLOCKED();
 948
 949         set_origin(vc);
 950         if (vc->vc_sw->con_flush_scrollback) {
 951                 vc->vc_sw->con_flush_scrollback(vc);
 952         } else if (con_is_visible(vc)) {
 953                 /*
 954                  * When no con_flush_scrollback method is provided then the
 955                  * legacy way for flushing the scrollback buffer is to use
 956                  * a side effect of the con_switch method. We do it only on
 957                  * the foreground console as background consoles have no
 958                  * scrollback buffers in that case and we obviously don't
 959                  * want to switch to them.
 960                  */
 961                 hide_cursor(vc);
 962                 vc->vc_sw->con_switch(vc);
 963                 set_cursor(vc);
 964         }
 965 }
 966
 967 /*
 968  *      Redrawing of screen
 969  */
 970
 971 void clear_buffer_attributes(struct vc_data *vc)
 972 {
 973         unsigned short *p = (unsigned short *)vc->vc_origin;
 974         int count = vc->vc_screenbuf_size / 2;
 975         int mask = vc->vc_hi_font_mask | 0xff;
 976
 977         for (; count > 0; count--, p++) {
 978                 scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
 979         }
 980 }
 981
 982 void redraw_screen(struct vc_data *vc, int is_switch)
 983 {
 984         int redraw = 0;
 985
 986         WARN_CONSOLE_UNLOCKED();
 987
 988         if (!vc) {
 989                 /* strange ... */
 990                 /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
 991                 return;
 992         }
 993
 994         if (is_switch) {
 995                 struct vc_data *old_vc = vc_cons[fg_console].d;
 996                 if (old_vc == vc)
 997                         return;
 998                 if (!con_is_visible(vc))
 999                         redraw = 1;
1000                 *vc->vc_display_fg = vc;
1001                 fg_console = vc->vc_num;
1002                 hide_cursor(old_vc);
1003                 if (!con_is_visible(old_vc)) {
1004                         save_screen(old_vc);
1005                         set_origin(old_vc);
1006                 }
1007                 if (tty0dev)
1008                         sysfs_notify(&tty0dev->kobj, NULL, "active");
1009         } else {
1010                 hide_cursor(vc);
1011                 redraw = 1;
1012         }
1013
1014         if (redraw) {
1015                 int update;
1016                 int old_was_color = vc->vc_can_do_color;
1017
1018                 set_origin(vc);
1019                 update = vc->vc_sw->con_switch(vc);
1020                 set_palette(vc);
1021                 /*
1022                  * If console changed from mono<->color, the best we can do
1023                  * is to clear the buffer attributes. As it currently stands,
1024                  * rebuilding new attributes from the old buffer is not doable
1025                  * without overly complex code.
1026                  */
1027                 if (old_was_color != vc->vc_can_do_color) {
1028                         update_attr(vc);
1029                         clear_buffer_attributes(vc);
1030                 }
1031
1032                 if (update && vc->vc_mode != KD_GRAPHICS)
1033                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1034         }
1035         set_cursor(vc);
1036         if (is_switch) {
1037                 set_leds();
1038                 compute_shiftstate();
1039                 notify_update(vc);
1040         }
1041 }
1042
1043 /*
1044  *      Allocation, freeing and resizing of VTs.
1045  */
1046
1047 int vc_cons_allocated(unsigned int i)
1048 {
1049         return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1050 }
1051
1052 static void visual_init(struct vc_data *vc, int num, int init)
1053 {
1054         /* ++Geert: vc->vc_sw->con_init determines console size */
1055         if (vc->vc_sw)
1056                 module_put(vc->vc_sw->owner);
1057         vc->vc_sw = conswitchp;
1058 #ifndef VT_SINGLE_DRIVER
1059         if (con_driver_map[num])
1060                 vc->vc_sw = con_driver_map[num];
1061 #endif
1062         __module_get(vc->vc_sw->owner);
1063         vc->vc_num = num;
1064         vc->vc_display_fg = &master_display_fg;
1065         if (vc->vc_uni_pagedir_loc)
1066                 con_free_unimap(vc);
1067         vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
1068         vc->vc_uni_pagedir = NULL;
1069         vc->vc_hi_font_mask = 0;
1070         vc->vc_complement_mask = 0;
1071         vc->vc_can_do_color = 0;
1072         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1073         vc->vc_sw->con_init(vc, init);
1074         if (!vc->vc_complement_mask)
1075                 vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1076         vc->vc_s_complement_mask = vc->vc_complement_mask;
1077         vc->vc_size_row = vc->vc_cols << 1;
1078         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1079 }
1080
1081
1082 static void visual_deinit(struct vc_data *vc)
1083 {
1084         vc->vc_sw->con_deinit(vc);
1085         module_put(vc->vc_sw->owner);
1086 }
1087
1088 static void vc_port_destruct(struct tty_port *port)
1089 {
1090         struct vc_data *vc = container_of(port, struct vc_data, port);
1091
1092         kfree(vc);
1093 }
1094
1095 static const struct tty_port_operations vc_port_ops = {
1096         .destruct = vc_port_destruct,
1097 };
1098
1099 int vc_allocate(unsigned int currcons)  /* return 0 on success */
1100 {
1101         struct vt_notifier_param param;
1102         struct vc_data *vc;
1103
1104         WARN_CONSOLE_UNLOCKED();
1105
1106         if (currcons >= MAX_NR_CONSOLES)
1107                 return -ENXIO;
1108
1109         if (vc_cons[currcons].d)
1110                 return 0;
1111
1112         /* due to the granularity of kmalloc, we waste some memory here */
1113         /* the alloc is done in two steps, to optimize the common situation
1114            of a 25x80 console (structsize=216, screenbuf_size=4000) */
1115         /* although the numbers above are not valid since long ago, the
1116            point is still up-to-date and the comment still has its value
1117            even if only as a historical artifact.  --mj, July 1998 */
1118         param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1119         if (!vc)
1120                 return -ENOMEM;
1121
1122         vc_cons[currcons].d = vc;
1123         tty_port_init(&vc->port);
1124         vc->port.ops = &vc_port_ops;
1125         INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1126
1127         visual_init(vc, currcons, 1);
1128
1129         if (!*vc->vc_uni_pagedir_loc)
1130                 con_set_default_unimap(vc);
1131
1132         vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1133         if (!vc->vc_screenbuf)
1134                 goto err_free;
1135
1136         /* If no drivers have overridden us and the user didn't pass a
1137            boot option, default to displaying the cursor */
1138         if (global_cursor_default == -1)
1139                 global_cursor_default = 1;
1140
1141         vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
1142         vcs_make_sysfs(currcons);
1143         atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1144
1145         return 0;
1146 err_free:
1147         visual_deinit(vc);
1148         kfree(vc);
1149         vc_cons[currcons].d = NULL;
1150         return -ENOMEM;
1151 }
1152
1153 static inline int resize_screen(struct vc_data *vc, int width, int height,
1154                                 int user)
1155 {
1156         /* Resizes the resolution of the display adapater */
1157         int err = 0;
1158
1159         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
1160                 err = vc->vc_sw->con_resize(vc, width, height, user);
1161
1162         return err;
1163 }
1164
1165 /*
1166  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1167  * [this is to be used together with some user program
1168  * like resize that changes the hardware videomode]
1169  */
1170 #define VC_RESIZE_MAXCOL (32767)
1171 #define VC_RESIZE_MAXROW (32767)
1172
1173 /**
1174  *      vc_do_resize    -       resizing method for the tty
1175  *      @tty: tty being resized
1176  *      @real_tty: real tty (different to tty if a pty/tty pair)
1177  *      @vc: virtual console private data
1178  *      @cols: columns
1179  *      @lines: lines
1180  *
1181  *      Resize a virtual console, clipping according to the actual constraints.
1182  *      If the caller passes a tty structure then update the termios winsize
1183  *      information and perform any necessary signal handling.
1184  *
1185  *      Caller must hold the console semaphore. Takes the termios rwsem and
1186  *      ctrl_lock of the tty IFF a tty is passed.
1187  */
1188
1189 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1190                                 unsigned int cols, unsigned int lines)
1191 {
1192         unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1193         unsigned long end;
1194         unsigned int old_rows, old_row_size, first_copied_row;
1195         unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1196         unsigned int user;
1197         unsigned short *newscreen;
1198         struct uni_screen *new_uniscr = NULL;
1199
1200         WARN_CONSOLE_UNLOCKED();
1201
1202         if (!vc)
1203                 return -ENXIO;
1204
1205         user = vc->vc_resize_user;
1206         vc->vc_resize_user = 0;
1207
1208         if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
1209                 return -EINVAL;
1210
1211         new_cols = (cols ? cols : vc->vc_cols);
1212         new_rows = (lines ? lines : vc->vc_rows);
1213         new_row_size = new_cols << 1;
1214         new_screen_size = new_row_size * new_rows;
1215
1216         if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
1217                 return 0;
1218
1219         if (new_screen_size > KMALLOC_MAX_SIZE)
1220                 return -EINVAL;
1221         newscreen = kzalloc(new_screen_size, GFP_USER);
1222         if (!newscreen)
1223                 return -ENOMEM;
1224
1225         if (get_vc_uniscr(vc)) {
1226                 new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1227                 if (!new_uniscr) {
1228                         kfree(newscreen);
1229                         return -ENOMEM;
1230                 }
1231         }
1232
1233         if (vc_is_sel(vc))
1234                 clear_selection();
1235
1236         old_rows = vc->vc_rows;
1237         old_row_size = vc->vc_size_row;
1238
1239         err = resize_screen(vc, new_cols, new_rows, user);
1240         if (err) {
1241                 kfree(newscreen);
1242                 vc_uniscr_free(new_uniscr);
1243                 return err;
1244         }
1245
1246         vc->vc_rows = new_rows;
1247         vc->vc_cols = new_cols;
1248         vc->vc_size_row = new_row_size;
1249         vc->vc_screenbuf_size = new_screen_size;
1250
1251         rlth = min(old_row_size, new_row_size);
1252         rrem = new_row_size - rlth;
1253         old_origin = vc->vc_origin;
1254         new_origin = (long) newscreen;
1255         new_scr_end = new_origin + new_screen_size;
1256
1257         if (vc->state.y > new_rows) {
1258                 if (old_rows - vc->state.y < new_rows) {
1259                         /*
1260                          * Cursor near the bottom, copy contents from the
1261                          * bottom of buffer
1262                          */
1263                         first_copied_row = (old_rows - new_rows);
1264                 } else {
1265                         /*
1266                          * Cursor is in no man's land, copy 1/2 screenful
1267                          * from the top and bottom of cursor position
1268                          */
1269                         first_copied_row = (vc->state.y - new_rows/2);
1270                 }
1271                 old_origin += first_copied_row * old_row_size;
1272         } else
1273                 first_copied_row = 0;
1274         end = old_origin + old_row_size * min(old_rows, new_rows);
1275
1276         vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1277                             get_vc_uniscr(vc), rlth/2, first_copied_row,
1278                             min(old_rows, new_rows));
1279         vc_uniscr_set(vc, new_uniscr);
1280
1281         update_attr(vc);
1282
1283         while (old_origin < end) {
1284                 scr_memcpyw((unsigned short *) new_origin,
1285                             (unsigned short *) old_origin, rlth);
1286                 if (rrem)
1287                         scr_memsetw((void *)(new_origin + rlth),
1288                                     vc->vc_video_erase_char, rrem);
1289                 old_origin += old_row_size;
1290                 new_origin += new_row_size;
1291         }
1292         if (new_scr_end > new_origin)
1293                 scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1294                             new_scr_end - new_origin);
1295         kfree(vc->vc_screenbuf);
1296         vc->vc_screenbuf = newscreen;
1297         vc->vc_screenbuf_size = new_screen_size;
1298         set_origin(vc);
1299
1300         /* do part of a reset_terminal() */
1301         vc->vc_top = 0;
1302         vc->vc_bottom = vc->vc_rows;
1303         gotoxy(vc, vc->state.x, vc->state.y);
1304         save_cur(vc);
1305
1306         if (tty) {
1307                 /* Rewrite the requested winsize data with the actual
1308                    resulting sizes */
1309                 struct winsize ws;
1310                 memset(&ws, 0, sizeof(ws));
1311                 ws.ws_row = vc->vc_rows;
1312                 ws.ws_col = vc->vc_cols;
1313                 ws.ws_ypixel = vc->vc_scan_lines;
1314                 tty_do_resize(tty, &ws);
1315         }
1316
1317         if (con_is_visible(vc))
1318                 update_screen(vc);
1319         vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1320         notify_update(vc);
1321         return err;
1322 }
1323
1324 /**
1325  *      vc_resize               -       resize a VT
1326  *      @vc: virtual console
1327  *      @cols: columns
1328  *      @rows: rows
1329  *
1330  *      Resize a virtual console as seen from the console end of things. We
1331  *      use the common vc_do_resize methods to update the structures. The
1332  *      caller must hold the console sem to protect console internals and
1333  *      vc->port.tty
1334  */
1335
1336 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1337 {
1338         return vc_do_resize(vc->port.tty, vc, cols, rows);
1339 }
1340
1341 /**
1342  *      vt_resize               -       resize a VT
1343  *      @tty: tty to resize
1344  *      @ws: winsize attributes
1345  *
1346  *      Resize a virtual terminal. This is called by the tty layer as we
1347  *      register our own handler for resizing. The mutual helper does all
1348  *      the actual work.
1349  *
1350  *      Takes the console sem and the called methods then take the tty
1351  *      termios_rwsem and the tty ctrl_lock in that order.
1352  */
1353 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1354 {
1355         struct vc_data *vc = tty->driver_data;
1356         int ret;
1357
1358         console_lock();
1359         ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1360         console_unlock();
1361         return ret;
1362 }
1363
1364 struct vc_data *vc_deallocate(unsigned int currcons)
1365 {
1366         struct vc_data *vc = NULL;
1367
1368         WARN_CONSOLE_UNLOCKED();
1369
1370         if (vc_cons_allocated(currcons)) {
1371                 struct vt_notifier_param param;
1372
1373                 param.vc = vc = vc_cons[currcons].d;
1374                 atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1375                 vcs_remove_sysfs(currcons);
1376                 visual_deinit(vc);
1377                 put_pid(vc->vt_pid);
1378                 vc_uniscr_set(vc, NULL);
1379                 kfree(vc->vc_screenbuf);
1380                 vc_cons[currcons].d = NULL;
1381         }
1382         return vc;
1383 }
1384
1385 /*
1386  *      VT102 emulator
1387  */
1388
1389 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1390
1391 #define set_kbd(vc, x)  vt_set_kbd_mode_bit((vc)->vc_num, (x))
1392 #define clr_kbd(vc, x)  vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1393 #define is_kbd(vc, x)   vt_get_kbd_mode_bit((vc)->vc_num, (x))
1394
1395 #define decarm          VC_REPEAT
1396 #define decckm          VC_CKMODE
1397 #define kbdapplic       VC_APPLIC
1398 #define lnm             VC_CRLF
1399
1400 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1401                                        8,12,10,14, 9,13,11,15 };
1402
1403 /* the default colour table, for VGA+ colour systems */
1404 unsigned char default_red[] = {
1405         0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1406         0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1407 };
1408 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1409
1410 unsigned char default_grn[] = {
1411         0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1412         0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1413 };
1414 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1415
1416 unsigned char default_blu[] = {
1417         0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1418         0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1419 };
1420 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1421
1422 /*
1423  * gotoxy() must verify all boundaries, because the arguments
1424  * might also be negative. If the given position is out of
1425  * bounds, the cursor is placed at the nearest margin.
1426  */
1427 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1428 {
1429         int min_y, max_y;
1430
1431         if (new_x < 0)
1432                 vc->state.x = 0;
1433         else {
1434                 if (new_x >= vc->vc_cols)
1435                         vc->state.x = vc->vc_cols - 1;
1436                 else
1437                         vc->state.x = new_x;
1438         }
1439
1440         if (vc->vc_decom) {
1441                 min_y = vc->vc_top;
1442                 max_y = vc->vc_bottom;
1443         } else {
1444                 min_y = 0;
1445                 max_y = vc->vc_rows;
1446         }
1447         if (new_y < min_y)
1448                 vc->state.y = min_y;
1449         else if (new_y >= max_y)
1450                 vc->state.y = max_y - 1;
1451         else
1452                 vc->state.y = new_y;
1453         vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
1454                 (vc->state.x << 1);
1455         vc->vc_need_wrap = 0;
1456 }
1457
1458 /* for absolute user moves, when decom is set */
1459 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1460 {
1461         gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1462 }
1463
1464 void scrollback(struct vc_data *vc)
1465 {
1466         scrolldelta(-(vc->vc_rows / 2));
1467 }
1468
1469 void scrollfront(struct vc_data *vc, int lines)
1470 {
1471         if (!lines)
1472                 lines = vc->vc_rows / 2;
1473         scrolldelta(lines);
1474 }
1475
1476 static void lf(struct vc_data *vc)
1477 {
1478         /* don't scroll if above bottom of scrolling region, or
1479          * if below scrolling region
1480          */
1481         if (vc->state.y + 1 == vc->vc_bottom)
1482                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1483         else if (vc->state.y < vc->vc_rows - 1) {
1484                 vc->state.y++;
1485                 vc->vc_pos += vc->vc_size_row;
1486         }
1487         vc->vc_need_wrap = 0;
1488         notify_write(vc, '\n');
1489 }
1490
1491 static void ri(struct vc_data *vc)
1492 {
1493         /* don't scroll if below top of scrolling region, or
1494          * if above scrolling region
1495          */
1496         if (vc->state.y == vc->vc_top)
1497                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1498         else if (vc->state.y > 0) {
1499                 vc->state.y--;
1500                 vc->vc_pos -= vc->vc_size_row;
1501         }
1502         vc->vc_need_wrap = 0;
1503 }
1504
1505 static inline void cr(struct vc_data *vc)
1506 {
1507         vc->vc_pos -= vc->state.x << 1;
1508         vc->vc_need_wrap = vc->state.x = 0;
1509         notify_write(vc, '\r');
1510 }
1511
1512 static inline void bs(struct vc_data *vc)
1513 {
1514         if (vc->state.x) {
1515                 vc->vc_pos -= 2;
1516                 vc->state.x--;
1517                 vc->vc_need_wrap = 0;
1518                 notify_write(vc, '\b');
1519         }
1520 }
1521
1522 static inline void del(struct vc_data *vc)
1523 {
1524         /* ignored */
1525 }
1526
1527 static void csi_J(struct vc_data *vc, int vpar)
1528 {
1529         unsigned int count;
1530         unsigned short * start;
1531
1532         switch (vpar) {
1533                 case 0: /* erase from cursor to end of display */
1534                         vc_uniscr_clear_line(vc, vc->state.x,
1535                                              vc->vc_cols - vc->state.x);
1536                         vc_uniscr_clear_lines(vc, vc->state.y + 1,
1537                                               vc->vc_rows - vc->state.y - 1);
1538                         count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1539                         start = (unsigned short *)vc->vc_pos;
1540                         break;
1541                 case 1: /* erase from start to cursor */
1542                         vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
1543                         vc_uniscr_clear_lines(vc, 0, vc->state.y);
1544                         count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1545                         start = (unsigned short *)vc->vc_origin;
1546                         break;
1547                 case 3: /* include scrollback */
1548                         flush_scrollback(vc);
1549                         /* fallthrough */
1550                 case 2: /* erase whole display */
1551                         vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1552                         count = vc->vc_cols * vc->vc_rows;
1553                         start = (unsigned short *)vc->vc_origin;
1554                         break;
1555                 default:
1556                         return;
1557         }
1558         scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1559         if (con_should_update(vc))
1560                 do_update_region(vc, (unsigned long) start, count);
1561         vc->vc_need_wrap = 0;
1562 }
1563
1564 static void csi_K(struct vc_data *vc, int vpar)
1565 {
1566         unsigned int count;
1567         unsigned short *start = (unsigned short *)vc->vc_pos;
1568         int offset;
1569
1570         switch (vpar) {
1571                 case 0: /* erase from cursor to end of line */
1572                         offset = 0;
1573                         count = vc->vc_cols - vc->state.x;
1574                         break;
1575                 case 1: /* erase from start of line to cursor */
1576                         offset = -vc->state.x;
1577                         count = vc->state.x + 1;
1578                         break;
1579                 case 2: /* erase whole line */
1580                         offset = -vc->state.x;
1581                         count = vc->vc_cols;
1582                         break;
1583                 default:
1584                         return;
1585         }
1586         vc_uniscr_clear_line(vc, vc->state.x + offset, count);
1587         scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1588         vc->vc_need_wrap = 0;
1589         if (con_should_update(vc))
1590                 do_update_region(vc, (unsigned long)(start + offset), count);
1591 }
1592
1593 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1594 {                                         /* not vt100? */
1595         int count;
1596
1597         if (!vpar)
1598                 vpar++;
1599         count = (vpar > vc->vc_cols - vc->state.x) ? (vc->vc_cols - vc->state.x) : vpar;
1600
1601         vc_uniscr_clear_line(vc, vc->state.x, count);
1602         scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1603         if (con_should_update(vc))
1604                 vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
1605         vc->vc_need_wrap = 0;
1606 }
1607
1608 static void default_attr(struct vc_data *vc)
1609 {
1610         vc->state.intensity = VCI_NORMAL;
1611         vc->state.italic = false;
1612         vc->state.underline = false;
1613         vc->state.reverse = false;
1614         vc->state.blink = false;
1615         vc->state.color = vc->vc_def_color;
1616 }
1617
1618 struct rgb { u8 r; u8 g; u8 b; };
1619
1620 static void rgb_from_256(int i, struct rgb *c)
1621 {
1622         if (i < 8) {            /* Standard colours. */
1623                 c->r = i&1 ? 0xaa : 0x00;
1624                 c->g = i&2 ? 0xaa : 0x00;
1625                 c->b = i&4 ? 0xaa : 0x00;
1626         } else if (i < 16) {
1627                 c->r = i&1 ? 0xff : 0x55;
1628                 c->g = i&2 ? 0xff : 0x55;
1629                 c->b = i&4 ? 0xff : 0x55;
1630         } else if (i < 232) {   /* 6x6x6 colour cube. */
1631                 c->r = (i - 16) / 36 * 85 / 2;
1632                 c->g = (i - 16) / 6 % 6 * 85 / 2;
1633                 c->b = (i - 16) % 6 * 85 / 2;
1634         } else                  /* Grayscale ramp. */
1635                 c->r = c->g = c->b = i * 10 - 2312;
1636 }
1637
1638 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1639 {
1640         u8 hue = 0, max = max3(c->r, c->g, c->b);
1641
1642         if (c->r > max / 2)
1643                 hue |= 4;
1644         if (c->g > max / 2)
1645                 hue |= 2;
1646         if (c->b > max / 2)
1647                 hue |= 1;
1648
1649         if (hue == 7 && max <= 0x55) {
1650                 hue = 0;
1651                 vc->state.intensity = VCI_BOLD;
1652         } else if (max > 0xaa)
1653                 vc->state.intensity = VCI_BOLD;
1654         else
1655                 vc->state.intensity = VCI_NORMAL;
1656
1657         vc->state.color = (vc->state.color & 0xf0) | hue;
1658 }
1659
1660 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1661 {
1662         /* For backgrounds, err on the dark side. */
1663         vc->state.color = (vc->state.color & 0x0f)
1664                 | (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1665 }
1666
1667 /*
1668  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1669  * and thus need to be detected and ignored by hand. That standard also
1670  * wants : rather than ; as separators but sequences containing : are currently
1671  * completely ignored by the parser.
1672  *
1673  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1674  * supporting them.
1675  */
1676 static int vc_t416_color(struct vc_data *vc, int i,
1677                 void(*set_color)(struct vc_data *vc, const struct rgb *c))
1678 {
1679         struct rgb c;
1680
1681         i++;
1682         if (i > vc->vc_npar)
1683                 return i;
1684
1685         if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1686                 /* 256 colours */
1687                 i++;
1688                 rgb_from_256(vc->vc_par[i], &c);
1689         } else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1690                 /* 24 bit */
1691                 c.r = vc->vc_par[i + 1];
1692                 c.g = vc->vc_par[i + 2];
1693                 c.b = vc->vc_par[i + 3];
1694                 i += 3;
1695         } else
1696                 return i;
1697
1698         set_color(vc, &c);
1699
1700         return i;
1701 }
1702
1703 /* console_lock is held */
1704 static void csi_m(struct vc_data *vc)
1705 {
1706         int i;
1707
1708         for (i = 0; i <= vc->vc_npar; i++)
1709                 switch (vc->vc_par[i]) {
1710                 case 0: /* all attributes off */
1711                         default_attr(vc);
1712                         break;
1713                 case 1:
1714                         vc->state.intensity = VCI_BOLD;
1715                         break;
1716                 case 2:
1717                         vc->state.intensity = VCI_HALF_BRIGHT;
1718                         break;
1719                 case 3:
1720                         vc->state.italic = true;
1721                         break;
1722                 case 21:
1723                         /*
1724                          * No console drivers support double underline, so
1725                          * convert it to a single underline.
1726                          */
1727                 case 4:
1728                         vc->state.underline = true;
1729                         break;
1730                 case 5:
1731                         vc->state.blink = true;
1732                         break;
1733                 case 7:
1734                         vc->state.reverse = true;
1735                         break;
1736                 case 10: /* ANSI X3.64-1979 (SCO-ish?)
1737                           * Select primary font, don't display control chars if
1738                           * defined, don't set bit 8 on output.
1739                           */
1740                         vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset], vc);
1741                         vc->vc_disp_ctrl = 0;
1742                         vc->vc_toggle_meta = 0;
1743                         break;
1744                 case 11: /* ANSI X3.64-1979 (SCO-ish?)
1745                           * Select first alternate font, lets chars < 32 be
1746                           * displayed as ROM chars.
1747                           */
1748                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1749                         vc->vc_disp_ctrl = 1;
1750                         vc->vc_toggle_meta = 0;
1751                         break;
1752                 case 12: /* ANSI X3.64-1979 (SCO-ish?)
1753                           * Select second alternate font, toggle high bit
1754                           * before displaying as ROM char.
1755                           */
1756                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1757                         vc->vc_disp_ctrl = 1;
1758                         vc->vc_toggle_meta = 1;
1759                         break;
1760                 case 22:
1761                         vc->state.intensity = VCI_NORMAL;
1762                         break;
1763                 case 23:
1764                         vc->state.italic = false;
1765                         break;
1766                 case 24:
1767                         vc->state.underline = false;
1768                         break;
1769                 case 25:
1770                         vc->state.blink = false;
1771                         break;
1772                 case 27:
1773                         vc->state.reverse = false;
1774                         break;
1775                 case 38:
1776                         i = vc_t416_color(vc, i, rgb_foreground);
1777                         break;
1778                 case 48:
1779                         i = vc_t416_color(vc, i, rgb_background);
1780                         break;
1781                 case 39:
1782                         vc->state.color = (vc->vc_def_color & 0x0f) |
1783                                 (vc->state.color & 0xf0);
1784                         break;
1785                 case 49:
1786                         vc->state.color = (vc->vc_def_color & 0xf0) |
1787                                 (vc->state.color & 0x0f);
1788                         break;
1789                 default:
1790                         if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1791                                 if (vc->vc_par[i] < 100)
1792                                         vc->state.intensity = VCI_BOLD;
1793                                 vc->vc_par[i] -= 60;
1794                         }
1795                         if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1796                                 vc->state.color = color_table[vc->vc_par[i] - 30]
1797                                         | (vc->state.color & 0xf0);
1798                         else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1799                                 vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
1800                                         | (vc->state.color & 0x0f);
1801                         break;
1802                 }
1803         update_attr(vc);
1804 }
1805
1806 static void respond_string(const char *p, size_t len, struct tty_port *port)
1807 {
1808         tty_insert_flip_string(port, p, len);
1809         tty_schedule_flip(port);
1810 }
1811
1812 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1813 {
1814         char buf[40];
1815         int len;
1816
1817         len = sprintf(buf, "\033[%d;%dR", vc->state.y +
1818                         (vc->vc_decom ? vc->vc_top + 1 : 1),
1819                         vc->state.x + 1);
1820         respond_string(buf, len, tty->port);
1821 }
1822
1823 static inline void status_report(struct tty_struct *tty)
1824 {
1825         static const char teminal_ok[] = "\033[0n";
1826
1827         respond_string(teminal_ok, strlen(teminal_ok), tty->port);
1828 }
1829
1830 static inline void respond_ID(struct tty_struct *tty)
1831 {
1832         /* terminal answer to an ESC-Z or csi0c query. */
1833         static const char vt102_id[] = "\033[?6c";
1834
1835         respond_string(vt102_id, strlen(vt102_id), tty->port);
1836 }
1837
1838 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1839 {
1840         char buf[8];
1841         int len;
1842
1843         len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
1844                         (char)('!' + mrx), (char)('!' + mry));
1845         respond_string(buf, len, tty->port);
1846 }
1847
1848 /* invoked via ioctl(TIOCLINUX) and through set_selection_user */
1849 int mouse_reporting(void)
1850 {
1851         return vc_cons[fg_console].d->vc_report_mouse;
1852 }
1853
1854 /* console_lock is held */
1855 static void set_mode(struct vc_data *vc, int on_off)
1856 {
1857         int i;
1858
1859         for (i = 0; i <= vc->vc_npar; i++)
1860                 if (vc->vc_priv == EPdec) {
1861                         switch(vc->vc_par[i]) { /* DEC private modes set/reset */
1862                         case 1:                 /* Cursor keys send ^[Ox/^[[x */
1863                                 if (on_off)
1864                                         set_kbd(vc, decckm);
1865                                 else
1866                                         clr_kbd(vc, decckm);
1867                                 break;
1868                         case 3: /* 80/132 mode switch unimplemented */
1869 #if 0
1870                                 vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1871                                 /* this alone does not suffice; some user mode
1872                                    utility has to change the hardware regs */
1873 #endif
1874                                 break;
1875                         case 5:                 /* Inverted screen on/off */
1876                                 if (vc->vc_decscnm != on_off) {
1877                                         vc->vc_decscnm = on_off;
1878                                         invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1879                                         update_attr(vc);
1880                                 }
1881                                 break;
1882                         case 6:                 /* Origin relative/absolute */
1883                                 vc->vc_decom = on_off;
1884                                 gotoxay(vc, 0, 0);
1885                                 break;
1886                         case 7:                 /* Autowrap on/off */
1887                                 vc->vc_decawm = on_off;
1888                                 break;
1889                         case 8:                 /* Autorepeat on/off */
1890                                 if (on_off)
1891                                         set_kbd(vc, decarm);
1892                                 else
1893                                         clr_kbd(vc, decarm);
1894                                 break;
1895                         case 9:
1896                                 vc->vc_report_mouse = on_off ? 1 : 0;
1897                                 break;
1898                         case 25:                /* Cursor on/off */
1899                                 vc->vc_deccm = on_off;
1900                                 break;
1901                         case 1000:
1902                                 vc->vc_report_mouse = on_off ? 2 : 0;
1903                                 break;
1904                         }
1905                 } else {
1906                         switch(vc->vc_par[i]) { /* ANSI modes set/reset */
1907                         case 3:                 /* Monitor (display ctrls) */
1908                                 vc->vc_disp_ctrl = on_off;
1909                                 break;
1910                         case 4:                 /* Insert Mode on/off */
1911                                 vc->vc_decim = on_off;
1912                                 break;
1913                         case 20:                /* Lf, Enter == CrLf/Lf */
1914                                 if (on_off)
1915                                         set_kbd(vc, lnm);
1916                                 else
1917                                         clr_kbd(vc, lnm);
1918                                 break;
1919                         }
1920                 }
1921 }
1922
1923 /* console_lock is held */
1924 static void setterm_command(struct vc_data *vc)
1925 {
1926         switch (vc->vc_par[0]) {
1927         case 1: /* set color for underline mode */
1928                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1929                         vc->vc_ulcolor = color_table[vc->vc_par[1]];
1930                         if (vc->state.underline)
1931                                 update_attr(vc);
1932                 }
1933                 break;
1934         case 2: /* set color for half intensity mode */
1935                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1936                         vc->vc_halfcolor = color_table[vc->vc_par[1]];
1937                         if (vc->state.intensity == VCI_HALF_BRIGHT)
1938                                 update_attr(vc);
1939                 }
1940                 break;
1941         case 8: /* store colors as defaults */
1942                 vc->vc_def_color = vc->vc_attr;
1943                 if (vc->vc_hi_font_mask == 0x100)
1944                         vc->vc_def_color >>= 1;
1945                 default_attr(vc);
1946                 update_attr(vc);
1947                 break;
1948         case 9: /* set blanking interval */
1949                 blankinterval = min(vc->vc_par[1], 60U) * 60;
1950                 poke_blanked_console();
1951                 break;
1952         case 10: /* set bell frequency in Hz */
1953                 if (vc->vc_npar >= 1)
1954                         vc->vc_bell_pitch = vc->vc_par[1];
1955                 else
1956                         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1957                 break;
1958         case 11: /* set bell duration in msec */
1959                 if (vc->vc_npar >= 1)
1960                         vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1961                                 msecs_to_jiffies(vc->vc_par[1]) : 0;
1962                 else
1963                         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1964                 break;
1965         case 12: /* bring specified console to the front */
1966                 if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1967                         set_console(vc->vc_par[1] - 1);
1968                 break;
1969         case 13: /* unblank the screen */
1970                 poke_blanked_console();
1971                 break;
1972         case 14: /* set vesa powerdown interval */
1973                 vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
1974                 break;
1975         case 15: /* activate the previous console */
1976                 set_console(last_console);
1977                 break;
1978         case 16: /* set cursor blink duration in msec */
1979                 if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1980                                 vc->vc_par[1] <= USHRT_MAX)
1981                         vc->vc_cur_blink_ms = vc->vc_par[1];
1982                 else
1983                         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1984                 break;
1985         }
1986 }
1987
1988 /* console_lock is held */
1989 static void csi_at(struct vc_data *vc, unsigned int nr)
1990 {
1991         if (nr > vc->vc_cols - vc->state.x)
1992                 nr = vc->vc_cols - vc->state.x;
1993         else if (!nr)
1994                 nr = 1;
1995         insert_char(vc, nr);
1996 }
1997
1998 /* console_lock is held */
1999 static void csi_L(struct vc_data *vc, unsigned int nr)
2000 {
2001         if (nr > vc->vc_rows - vc->state.y)
2002                 nr = vc->vc_rows - vc->state.y;
2003         else if (!nr)
2004                 nr = 1;
2005         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
2006         vc->vc_need_wrap = 0;
2007 }
2008
2009 /* console_lock is held */
2010 static void csi_P(struct vc_data *vc, unsigned int nr)
2011 {
2012         if (nr > vc->vc_cols - vc->state.x)
2013                 nr = vc->vc_cols - vc->state.x;
2014         else if (!nr)
2015                 nr = 1;
2016         delete_char(vc, nr);
2017 }
2018
2019 /* console_lock is held */
2020 static void csi_M(struct vc_data *vc, unsigned int nr)
2021 {
2022         if (nr > vc->vc_rows - vc->state.y)
2023                 nr = vc->vc_rows - vc->state.y;
2024         else if (!nr)
2025                 nr=1;
2026         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
2027         vc->vc_need_wrap = 0;
2028 }
2029
2030 /* console_lock is held (except via vc_init->reset_terminal */
2031 static void save_cur(struct vc_data *vc)
2032 {
2033         memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
2034 }
2035
2036 /* console_lock is held */
2037 static void restore_cur(struct vc_data *vc)
2038 {
2039         memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
2040
2041         gotoxy(vc, vc->state.x, vc->state.y);
2042         vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
2043                         vc);
2044         update_attr(vc);
2045         vc->vc_need_wrap = 0;
2046 }
2047
2048 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2049         EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2050         ESpalette, ESosc };
2051
2052 /* console_lock is held (except via vc_init()) */
2053 static void reset_terminal(struct vc_data *vc, int do_clear)
2054 {
2055         unsigned int i;
2056
2057         vc->vc_top              = 0;
2058         vc->vc_bottom           = vc->vc_rows;
2059         vc->vc_state            = ESnormal;
2060         vc->vc_priv             = EPecma;
2061         vc->vc_translate        = set_translate(LAT1_MAP, vc);
2062         vc->state.Gx_charset[0] = LAT1_MAP;
2063         vc->state.Gx_charset[1] = GRAF_MAP;
2064         vc->state.charset       = 0;
2065         vc->vc_need_wrap        = 0;
2066         vc->vc_report_mouse     = 0;
2067         vc->vc_utf              = default_utf8;
2068         vc->vc_utf_count        = 0;
2069
2070         vc->vc_disp_ctrl        = 0;
2071         vc->vc_toggle_meta      = 0;
2072
2073         vc->vc_decscnm          = 0;
2074         vc->vc_decom            = 0;
2075         vc->vc_decawm           = 1;
2076         vc->vc_deccm            = global_cursor_default;
2077         vc->vc_decim            = 0;
2078
2079         vt_reset_keyboard(vc->vc_num);
2080
2081         vc->vc_cursor_type = cur_default;
2082         vc->vc_complement_mask = vc->vc_s_complement_mask;
2083
2084         default_attr(vc);
2085         update_attr(vc);
2086
2087         bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2088         for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
2089                 set_bit(i, vc->vc_tab_stop);
2090
2091         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2092         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2093         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2094
2095         gotoxy(vc, 0, 0);
2096         save_cur(vc);
2097         if (do_clear)
2098             csi_J(vc, 2);
2099 }
2100
2101 static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
2102 {
2103         unsigned char *charset = &vc->state.Gx_charset[which];
2104
2105         switch (c) {
2106         case '0':
2107                 *charset = GRAF_MAP;
2108                 break;
2109         case 'B':
2110                 *charset = LAT1_MAP;
2111                 break;
2112         case 'U':
2113                 *charset = IBMPC_MAP;
2114                 break;
2115         case 'K':
2116                 *charset = USER_MAP;
2117                 break;
2118         }
2119
2120         if (vc->state.charset == which)
2121                 vc->vc_translate = set_translate(*charset, vc);
2122 }
2123
2124 /* console_lock is held */
2125 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2126 {
2127         /*
2128          *  Control characters can be used in the _middle_
2129          *  of an escape sequence.
2130          */
2131         if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
2132                 return;
2133         switch (c) {
2134         case 0:
2135                 return;
2136         case 7:
2137                 if (vc->vc_state == ESosc)
2138                         vc->vc_state = ESnormal;
2139                 else if (vc->vc_bell_duration)
2140                         kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2141                 return;
2142         case 8:
2143                 bs(vc);
2144                 return;
2145         case 9:
2146                 vc->vc_pos -= (vc->state.x << 1);
2147
2148                 vc->state.x = find_next_bit(vc->vc_tab_stop,
2149                                 min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2150                                 vc->state.x + 1);
2151                 if (vc->state.x >= VC_TABSTOPS_COUNT)
2152                         vc->state.x = vc->vc_cols - 1;
2153
2154                 vc->vc_pos += (vc->state.x << 1);
2155                 notify_write(vc, '\t');
2156                 return;
2157         case 10: case 11: case 12:
2158                 lf(vc);
2159                 if (!is_kbd(vc, lnm))
2160                         return;
2161                 /* fall through */
2162         case 13:
2163                 cr(vc);
2164                 return;
2165         case 14:
2166                 vc->state.charset = 1;
2167                 vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2168                 vc->vc_disp_ctrl = 1;
2169                 return;
2170         case 15:
2171                 vc->state.charset = 0;
2172                 vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2173                 vc->vc_disp_ctrl = 0;
2174                 return;
2175         case 24: case 26:
2176                 vc->vc_state = ESnormal;
2177                 return;
2178         case 27:
2179                 vc->vc_state = ESesc;
2180                 return;
2181         case 127:
2182                 del(vc);
2183                 return;
2184         case 128+27:
2185                 vc->vc_state = ESsquare;
2186                 return;
2187         }
2188         switch(vc->vc_state) {
2189         case ESesc:
2190                 vc->vc_state = ESnormal;
2191                 switch (c) {
2192                 case '[':
2193                         vc->vc_state = ESsquare;
2194                         return;
2195                 case ']':
2196                         vc->vc_state = ESnonstd;
2197                         return;
2198                 case '%':
2199                         vc->vc_state = ESpercent;
2200                         return;
2201                 case 'E':
2202                         cr(vc);
2203                         lf(vc);
2204                         return;
2205                 case 'M':
2206                         ri(vc);
2207                         return;
2208                 case 'D':
2209                         lf(vc);
2210                         return;
2211                 case 'H':
2212                         if (vc->state.x < VC_TABSTOPS_COUNT)
2213                                 set_bit(vc->state.x, vc->vc_tab_stop);
2214                         return;
2215                 case 'Z':
2216                         respond_ID(tty);
2217                         return;
2218                 case '7':
2219                         save_cur(vc);
2220                         return;
2221                 case '8':
2222                         restore_cur(vc);
2223                         return;
2224                 case '(':
2225                         vc->vc_state = ESsetG0;
2226                         return;
2227                 case ')':
2228                         vc->vc_state = ESsetG1;
2229                         return;
2230                 case '#':
2231                         vc->vc_state = EShash;
2232                         return;
2233                 case 'c':
2234                         reset_terminal(vc, 1);
2235                         return;
2236                 case '>':  /* Numeric keypad */
2237                         clr_kbd(vc, kbdapplic);
2238                         return;
2239                 case '=':  /* Appl. keypad */
2240                         set_kbd(vc, kbdapplic);
2241                         return;
2242                 }
2243                 return;
2244         case ESnonstd:
2245                 if (c=='P') {   /* palette escape sequence */
2246                         for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2247                                 vc->vc_par[vc->vc_npar] = 0;
2248                         vc->vc_npar = 0;
2249                         vc->vc_state = ESpalette;
2250                         return;
2251                 } else if (c=='R') {   /* reset palette */
2252                         reset_palette(vc);
2253                         vc->vc_state = ESnormal;
2254                 } else if (c>='0' && c<='9')
2255                         vc->vc_state = ESosc;
2256                 else
2257                         vc->vc_state = ESnormal;
2258                 return;
2259         case ESpalette:
2260                 if (isxdigit(c)) {
2261                         vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2262                         if (vc->vc_npar == 7) {
2263                                 int i = vc->vc_par[0] * 3, j = 1;
2264                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2265                                 vc->vc_palette[i++] += vc->vc_par[j++];
2266                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2267                                 vc->vc_palette[i++] += vc->vc_par[j++];
2268                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2269                                 vc->vc_palette[i] += vc->vc_par[j];
2270                                 set_palette(vc);
2271                                 vc->vc_state = ESnormal;
2272                         }
2273                 } else
2274                         vc->vc_state = ESnormal;
2275                 return;
2276         case ESsquare:
2277                 for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2278                         vc->vc_par[vc->vc_npar] = 0;
2279                 vc->vc_npar = 0;
2280                 vc->vc_state = ESgetpars;
2281                 if (c == '[') { /* Function key */
2282                         vc->vc_state=ESfunckey;
2283                         return;
2284                 }
2285                 switch (c) {
2286                 case '?':
2287                         vc->vc_priv = EPdec;
2288                         return;
2289                 case '>':
2290                         vc->vc_priv = EPgt;
2291                         return;
2292                 case '=':
2293                         vc->vc_priv = EPeq;
2294                         return;
2295                 case '<':
2296                         vc->vc_priv = EPlt;
2297                         return;
2298                 }
2299                 vc->vc_priv = EPecma;
2300                 /* fall through */
2301         case ESgetpars:
2302                 if (c == ';' && vc->vc_npar < NPAR - 1) {
2303                         vc->vc_npar++;
2304                         return;
2305                 } else if (c>='0' && c<='9') {
2306                         vc->vc_par[vc->vc_npar] *= 10;
2307                         vc->vc_par[vc->vc_npar] += c - '0';
2308                         return;
2309                 }
2310                 if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2311                         vc->vc_state = EScsiignore;
2312                         return;
2313                 }
2314                 vc->vc_state = ESnormal;
2315                 switch(c) {
2316                 case 'h':
2317                         if (vc->vc_priv <= EPdec)
2318                                 set_mode(vc, 1);
2319                         return;
2320                 case 'l':
2321                         if (vc->vc_priv <= EPdec)
2322                                 set_mode(vc, 0);
2323                         return;
2324                 case 'c':
2325                         if (vc->vc_priv == EPdec) {
2326                                 if (vc->vc_par[0])
2327                                         vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
2328                                 else
2329                                         vc->vc_cursor_type = cur_default;
2330                                 return;
2331                         }
2332                         break;
2333                 case 'm':
2334                         if (vc->vc_priv == EPdec) {
2335                                 clear_selection();
2336                                 if (vc->vc_par[0])
2337                                         vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2338                                 else
2339                                         vc->vc_complement_mask = vc->vc_s_complement_mask;
2340                                 return;
2341                         }
2342                         break;
2343                 case 'n':
2344                         if (vc->vc_priv == EPecma) {
2345                                 if (vc->vc_par[0] == 5)
2346                                         status_report(tty);
2347                                 else if (vc->vc_par[0] == 6)
2348                                         cursor_report(vc, tty);
2349                         }
2350                         return;
2351                 }
2352                 if (vc->vc_priv != EPecma) {
2353                         vc->vc_priv = EPecma;
2354                         return;
2355                 }
2356                 switch(c) {
2357                 case 'G': case '`':
2358                         if (vc->vc_par[0])
2359                                 vc->vc_par[0]--;
2360                         gotoxy(vc, vc->vc_par[0], vc->state.y);
2361                         return;
2362                 case 'A':
2363                         if (!vc->vc_par[0])
2364                                 vc->vc_par[0]++;
2365                         gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2366                         return;
2367                 case 'B': case 'e':
2368                         if (!vc->vc_par[0])
2369                                 vc->vc_par[0]++;
2370                         gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2371                         return;
2372                 case 'C': case 'a':
2373                         if (!vc->vc_par[0])
2374                                 vc->vc_par[0]++;
2375                         gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2376                         return;
2377                 case 'D':
2378                         if (!vc->vc_par[0])
2379                                 vc->vc_par[0]++;
2380                         gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2381                         return;
2382                 case 'E':
2383                         if (!vc->vc_par[0])
2384                                 vc->vc_par[0]++;
2385                         gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2386                         return;
2387                 case 'F':
2388                         if (!vc->vc_par[0])
2389                                 vc->vc_par[0]++;
2390                         gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2391                         return;
2392                 case 'd':
2393                         if (vc->vc_par[0])
2394                                 vc->vc_par[0]--;
2395                         gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2396                         return;
2397                 case 'H': case 'f':
2398                         if (vc->vc_par[0])
2399                                 vc->vc_par[0]--;
2400                         if (vc->vc_par[1])
2401                                 vc->vc_par[1]--;
2402                         gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2403                         return;
2404                 case 'J':
2405                         csi_J(vc, vc->vc_par[0]);
2406                         return;
2407                 case 'K':
2408                         csi_K(vc, vc->vc_par[0]);
2409                         return;
2410                 case 'L':
2411                         csi_L(vc, vc->vc_par[0]);
2412                         return;
2413                 case 'M':
2414                         csi_M(vc, vc->vc_par[0]);
2415                         return;
2416                 case 'P':
2417                         csi_P(vc, vc->vc_par[0]);
2418                         return;
2419                 case 'c':
2420                         if (!vc->vc_par[0])
2421                                 respond_ID(tty);
2422                         return;
2423                 case 'g':
2424                         if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2425                                 set_bit(vc->state.x, vc->vc_tab_stop);
2426                         else if (vc->vc_par[0] == 3)
2427                                 bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2428                         return;
2429                 case 'm':
2430                         csi_m(vc);
2431                         return;
2432                 case 'q': /* DECLL - but only 3 leds */
2433                         /* map 0,1,2,3 to 0,1,2,4 */
2434                         if (vc->vc_par[0] < 4)
2435                                 vt_set_led_state(vc->vc_num,
2436                                             (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2437                         return;
2438                 case 'r':
2439                         if (!vc->vc_par[0])
2440                                 vc->vc_par[0]++;
2441                         if (!vc->vc_par[1])
2442                                 vc->vc_par[1] = vc->vc_rows;
2443                         /* Minimum allowed region is 2 lines */
2444                         if (vc->vc_par[0] < vc->vc_par[1] &&
2445                             vc->vc_par[1] <= vc->vc_rows) {
2446                                 vc->vc_top = vc->vc_par[0] - 1;
2447                                 vc->vc_bottom = vc->vc_par[1];
2448                                 gotoxay(vc, 0, 0);
2449                         }
2450                         return;
2451                 case 's':
2452                         save_cur(vc);
2453                         return;
2454                 case 'u':
2455                         restore_cur(vc);
2456                         return;
2457                 case 'X':
2458                         csi_X(vc, vc->vc_par[0]);
2459                         return;
2460                 case '@':
2461                         csi_at(vc, vc->vc_par[0]);
2462                         return;
2463                 case ']': /* setterm functions */
2464                         setterm_command(vc);
2465                         return;
2466                 }
2467                 return;
2468         case EScsiignore:
2469                 if (c >= 20 && c <= 0x3f)
2470                         return;
2471                 vc->vc_state = ESnormal;
2472                 return;
2473         case ESpercent:
2474                 vc->vc_state = ESnormal;
2475                 switch (c) {
2476                 case '@':  /* defined in ISO 2022 */
2477                         vc->vc_utf = 0;
2478                         return;
2479                 case 'G':  /* prelim official escape code */
2480                 case '8':  /* retained for compatibility */
2481                         vc->vc_utf = 1;
2482                         return;
2483                 }
2484                 return;
2485         case ESfunckey:
2486                 vc->vc_state = ESnormal;
2487                 return;
2488         case EShash:
2489                 vc->vc_state = ESnormal;
2490                 if (c == '8') {
2491                         /* DEC screen alignment test. kludge :-) */
2492                         vc->vc_video_erase_char =
2493                                 (vc->vc_video_erase_char & 0xff00) | 'E';
2494                         csi_J(vc, 2);
2495                         vc->vc_video_erase_char =
2496                                 (vc->vc_video_erase_char & 0xff00) | ' ';
2497                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2498                 }
2499                 return;
2500         case ESsetG0:
2501                 vc_setGx(vc, 0, c);
2502                 vc->vc_state = ESnormal;
2503                 return;
2504         case ESsetG1:
2505                 vc_setGx(vc, 1, c);
2506                 vc->vc_state = ESnormal;
2507                 return;
2508         case ESosc:
2509                 return;
2510         default:
2511                 vc->vc_state = ESnormal;
2512         }
2513 }
2514
2515 /* is_double_width() is based on the wcwidth() implementation by
2516  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2517  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2518  */
2519 struct interval {
2520         uint32_t first;
2521         uint32_t last;
2522 };
2523
2524 static int ucs_cmp(const void *key, const void *elt)
2525 {
2526         uint32_t ucs = *(uint32_t *)key;
2527         struct interval e = *(struct interval *) elt;
2528
2529         if (ucs > e.last)
2530                 return 1;
2531         else if (ucs < e.first)
2532                 return -1;
2533         return 0;
2534 }
2535
2536 static int is_double_width(uint32_t ucs)
2537 {
2538         static const struct interval double_width[] = {
2539                 { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2540                 { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2541                 { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2542                 { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2543         };
2544         if (ucs < double_width[0].first ||
2545             ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2546                 return 0;
2547
2548         return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2549                         sizeof(struct interval), ucs_cmp) != NULL;
2550 }
2551
2552 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2553                 unsigned long draw_to, int *draw_x)
2554 {
2555         if (*draw_x < 0)
2556                 return;
2557
2558         vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2559                         (u16 *)draw_to - (u16 *)draw_from, vc->state.y, *draw_x);
2560         *draw_x = -1;
2561 }
2562
2563 /* acquires console_lock */
2564 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2565 {
2566         int c, next_c, tc, ok, n = 0, draw_x = -1;
2567         unsigned int currcons;
2568         unsigned long draw_from = 0, draw_to = 0;
2569         struct vc_data *vc;
2570         unsigned char vc_attr;
2571         struct vt_notifier_param param;
2572         uint8_t rescan;
2573         uint8_t inverse;
2574         uint8_t width;
2575         u16 himask, charmask;
2576
2577         if (in_interrupt())
2578                 return count;
2579
2580         console_lock();
2581         vc = tty->driver_data;
2582         if (vc == NULL) {
2583                 pr_err("vt: argh, driver_data is NULL !\n");
2584                 console_unlock();
2585                 return 0;
2586         }
2587
2588         currcons = vc->vc_num;
2589         if (!vc_cons_allocated(currcons)) {
2590                 /* could this happen? */
2591                 pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2592                 console_unlock();
2593                 return 0;
2594         }
2595
2596         himask = vc->vc_hi_font_mask;
2597         charmask = himask ? 0x1ff : 0xff;
2598
2599         /* undraw cursor first */
2600         if (con_is_fg(vc))
2601                 hide_cursor(vc);
2602
2603         param.vc = vc;
2604
2605         while (!tty->stopped && count) {
2606                 int orig = *buf;
2607                 c = orig;
2608                 buf++;
2609                 n++;
2610                 count--;
2611                 rescan = 0;
2612                 inverse = 0;
2613                 width = 1;
2614
2615                 /* Do no translation at all in control states */
2616                 if (vc->vc_state != ESnormal) {
2617                         tc = c;
2618                 } else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2619                     /* Combine UTF-8 into Unicode in vc_utf_char.
2620                      * vc_utf_count is the number of continuation bytes still
2621                      * expected to arrive.
2622                      * vc_npar is the number of continuation bytes arrived so
2623                      * far
2624                      */
2625 rescan_last_byte:
2626                     if ((c & 0xc0) == 0x80) {
2627                         /* Continuation byte received */
2628                         static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2629                         if (vc->vc_utf_count) {
2630                             vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2631                             vc->vc_npar++;
2632                             if (--vc->vc_utf_count) {
2633                                 /* Still need some bytes */
2634                                 continue;
2635                             }
2636                             /* Got a whole character */
2637                             c = vc->vc_utf_char;
2638                             /* Reject overlong sequences */
2639                             if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2640                                         c > utf8_length_changes[vc->vc_npar])
2641                                 c = 0xfffd;
2642                         } else {
2643                             /* Unexpected continuation byte */
2644                             vc->vc_utf_count = 0;
2645                             c = 0xfffd;
2646                         }
2647                     } else {
2648                         /* Single ASCII byte or first byte of a sequence received */
2649                         if (vc->vc_utf_count) {
2650                             /* Continuation byte expected */
2651                             rescan = 1;
2652                             vc->vc_utf_count = 0;
2653                             c = 0xfffd;
2654                         } else if (c > 0x7f) {
2655                             /* First byte of a multibyte sequence received */
2656                             vc->vc_npar = 0;
2657                             if ((c & 0xe0) == 0xc0) {
2658                                 vc->vc_utf_count = 1;
2659                                 vc->vc_utf_char = (c & 0x1f);
2660                             } else if ((c & 0xf0) == 0xe0) {
2661                                 vc->vc_utf_count = 2;
2662                                 vc->vc_utf_char = (c & 0x0f);
2663                             } else if ((c & 0xf8) == 0xf0) {
2664                                 vc->vc_utf_count = 3;
2665                                 vc->vc_utf_char = (c & 0x07);
2666                             } else if ((c & 0xfc) == 0xf8) {
2667                                 vc->vc_utf_count = 4;
2668                                 vc->vc_utf_char = (c & 0x03);
2669                             } else if ((c & 0xfe) == 0xfc) {
2670                                 vc->vc_utf_count = 5;
2671                                 vc->vc_utf_char = (c & 0x01);
2672                             } else {
2673                                 /* 254 and 255 are invalid */
2674                                 c = 0xfffd;
2675                             }
2676                             if (vc->vc_utf_count) {
2677                                 /* Still need some bytes */
2678                                 continue;
2679                             }
2680                         }
2681                         /* Nothing to do if an ASCII byte was received */
2682                     }
2683                     /* End of UTF-8 decoding. */
2684                     /* c is the received character, or U+FFFD for invalid sequences. */
2685                     /* Replace invalid Unicode code points with U+FFFD too */
2686                     if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2687                         c = 0xfffd;
2688                     tc = c;
2689                 } else {        /* no utf or alternate charset mode */
2690                     tc = vc_translate(vc, c);
2691                 }
2692
2693                 param.c = tc;
2694                 if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2695                                         &param) == NOTIFY_STOP)
2696                         continue;
2697
2698                 /* If the original code was a control character we
2699                  * only allow a glyph to be displayed if the code is
2700                  * not normally used (such as for cursor movement) or
2701                  * if the disp_ctrl mode has been explicitly enabled.
2702                  * Certain characters (as given by the CTRL_ALWAYS
2703                  * bitmap) are always displayed as control characters,
2704                  * as the console would be pretty useless without
2705                  * them; to display an arbitrary font position use the
2706                  * direct-to-font zone in UTF-8 mode.
2707                  */
2708                 ok = tc && (c >= 32 ||
2709                             !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2710                                   vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2711                         && (c != 127 || vc->vc_disp_ctrl)
2712                         && (c != 128+27);
2713
2714                 if (vc->vc_state == ESnormal && ok) {
2715                         if (vc->vc_utf && !vc->vc_disp_ctrl) {
2716                                 if (is_double_width(c))
2717                                         width = 2;
2718                         }
2719                         /* Now try to find out how to display it */
2720                         tc = conv_uni_to_pc(vc, tc);
2721                         if (tc & ~charmask) {
2722                                 if (tc == -1 || tc == -2) {
2723                                     continue; /* nothing to display */
2724                                 }
2725                                 /* Glyph not found */
2726                                 if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2727                                     /* In legacy mode use the glyph we get by a 1:1 mapping.
2728                                        This would make absolutely no sense with Unicode in mind,
2729                                        but do this for ASCII characters since a font may lack
2730                                        Unicode mapping info and we don't want to end up with
2731                                        having question marks only. */
2732                                     tc = c;
2733                                 } else {
2734                                     /* Display U+FFFD. If it's not found, display an inverse question mark. */
2735                                     tc = conv_uni_to_pc(vc, 0xfffd);
2736                                     if (tc < 0) {
2737                                         inverse = 1;
2738                                         tc = conv_uni_to_pc(vc, '?');
2739                                         if (tc < 0) tc = '?';
2740                                     }
2741                                 }
2742                         }
2743
2744                         if (!inverse) {
2745                                 vc_attr = vc->vc_attr;
2746                         } else {
2747                                 /* invert vc_attr */
2748                                 if (!vc->vc_can_do_color) {
2749                                         vc_attr = (vc->vc_attr) ^ 0x08;
2750                                 } else if (vc->vc_hi_font_mask == 0x100) {
2751                                         vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2752                                 } else {
2753                                         vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2754                                 }
2755                                 con_flush(vc, draw_from, draw_to, &draw_x);
2756                         }
2757
2758                         next_c = c;
2759                         while (1) {
2760                                 if (vc->vc_need_wrap || vc->vc_decim)
2761                                         con_flush(vc, draw_from, draw_to,
2762                                                         &draw_x);
2763                                 if (vc->vc_need_wrap) {
2764                                         cr(vc);
2765                                         lf(vc);
2766                                 }
2767                                 if (vc->vc_decim)
2768                                         insert_char(vc, 1);
2769                                 vc_uniscr_putc(vc, next_c);
2770                                 scr_writew(himask ?
2771                                              ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2772                                              (vc_attr << 8) + tc,
2773                                            (u16 *) vc->vc_pos);
2774                                 if (con_should_update(vc) && draw_x < 0) {
2775                                         draw_x = vc->state.x;
2776                                         draw_from = vc->vc_pos;
2777                                 }
2778                                 if (vc->state.x == vc->vc_cols - 1) {
2779                                         vc->vc_need_wrap = vc->vc_decawm;
2780                                         draw_to = vc->vc_pos + 2;
2781                                 } else {
2782                                         vc->state.x++;
2783                                         draw_to = (vc->vc_pos += 2);
2784                                 }
2785
2786                                 if (!--width) break;
2787
2788                                 tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2789                                 if (tc < 0) tc = ' ';
2790                                 next_c = ' ';
2791                         }
2792                         notify_write(vc, c);
2793
2794                         if (inverse)
2795                                 con_flush(vc, draw_from, draw_to, &draw_x);
2796
2797                         if (rescan) {
2798                                 rescan = 0;
2799                                 inverse = 0;
2800                                 width = 1;
2801                                 c = orig;
2802                                 goto rescan_last_byte;
2803                         }
2804                         continue;
2805                 }
2806                 con_flush(vc, draw_from, draw_to, &draw_x);
2807                 do_con_trol(tty, vc, orig);
2808         }
2809         con_flush(vc, draw_from, draw_to, &draw_x);
2810         vc_uniscr_debug_check(vc);
2811         console_conditional_schedule();
2812         notify_update(vc);
2813         console_unlock();
2814         return n;
2815 }
2816
2817 /*
2818  * This is the console switching callback.
2819  *
2820  * Doing console switching in a process context allows
2821  * us to do the switches asynchronously (needed when we want
2822  * to switch due to a keyboard interrupt).  Synchronization
2823  * with other console code and prevention of re-entrancy is
2824  * ensured with console_lock.
2825  */
2826 static void console_callback(struct work_struct *ignored)
2827 {
2828         console_lock();
2829
2830         if (want_console >= 0) {
2831                 if (want_console != fg_console &&
2832                     vc_cons_allocated(want_console)) {
2833                         hide_cursor(vc_cons[fg_console].d);
2834                         change_console(vc_cons[want_console].d);
2835                         /* we only changed when the console had already
2836                            been allocated - a new console is not created
2837                            in an interrupt routine */
2838                 }
2839                 want_console = -1;
2840         }
2841         if (do_poke_blanked_console) { /* do not unblank for a LED change */
2842                 do_poke_blanked_console = 0;
2843                 poke_blanked_console();
2844         }
2845         if (scrollback_delta) {
2846                 struct vc_data *vc = vc_cons[fg_console].d;
2847                 clear_selection();
2848                 if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2849                         vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2850                 scrollback_delta = 0;
2851         }
2852         if (blank_timer_expired) {
2853                 do_blank_screen(0);
2854                 blank_timer_expired = 0;
2855         }
2856         notify_update(vc_cons[fg_console].d);
2857
2858         console_unlock();
2859 }
2860
2861 int set_console(int nr)
2862 {
2863         struct vc_data *vc = vc_cons[fg_console].d;
2864
2865         if (!vc_cons_allocated(nr) || vt_dont_switch ||
2866                 (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2867
2868                 /*
2869                  * Console switch will fail in console_callback() or
2870                  * change_console() so there is no point scheduling
2871                  * the callback
2872                  *
2873                  * Existing set_console() users don't check the return
2874                  * value so this shouldn't break anything
2875                  */
2876                 return -EINVAL;
2877         }
2878
2879         want_console = nr;
2880         schedule_console_callback();
2881
2882         return 0;
2883 }
2884
2885 struct tty_driver *console_driver;
2886
2887 #ifdef CONFIG_VT_CONSOLE
2888
2889 /**
2890  * vt_kmsg_redirect() - Sets/gets the kernel message console
2891  * @new:        The new virtual terminal number or -1 if the console should stay
2892  *              unchanged
2893  *
2894  * By default, the kernel messages are always printed on the current virtual
2895  * console. However, the user may modify that default with the
2896  * TIOCL_SETKMSGREDIRECT ioctl call.
2897  *
2898  * This function sets the kernel message console to be @new. It returns the old
2899  * virtual console number. The virtual terminal number 0 (both as parameter and
2900  * return value) means no redirection (i.e. always printed on the currently
2901  * active console).
2902  *
2903  * The parameter -1 means that only the current console is returned, but the
2904  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2905  * case to make the code more understandable.
2906  *
2907  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2908  * the parameter and always returns 0.
2909  */
2910 int vt_kmsg_redirect(int new)
2911 {
2912         static int kmsg_con;
2913
2914         if (new != -1)
2915                 return xchg(&kmsg_con, new);
2916         else
2917                 return kmsg_con;
2918 }
2919
2920 /*
2921  *      Console on virtual terminal
2922  *
2923  * The console must be locked when we get here.
2924  */
2925
2926 static void vt_console_print(struct console *co, const char *b, unsigned count)
2927 {
2928         struct vc_data *vc = vc_cons[fg_console].d;
2929         unsigned char c;
2930         static DEFINE_SPINLOCK(printing_lock);
2931         const ushort *start;
2932         ushort start_x, cnt;
2933         int kmsg_console;
2934
2935         /* console busy or not yet initialized */
2936         if (!printable)
2937                 return;
2938         if (!spin_trylock(&printing_lock))
2939                 return;
2940
2941         kmsg_console = vt_get_kmsg_redirect();
2942         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2943                 vc = vc_cons[kmsg_console - 1].d;
2944
2945         if (!vc_cons_allocated(fg_console)) {
2946                 /* impossible */
2947                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2948                 goto quit;
2949         }
2950
2951         if (vc->vc_mode != KD_TEXT)
2952                 goto quit;
2953
2954         /* undraw cursor first */
2955         if (con_is_fg(vc))
2956                 hide_cursor(vc);
2957
2958         start = (ushort *)vc->vc_pos;
2959         start_x = vc->state.x;
2960         cnt = 0;
2961         while (count--) {
2962                 c = *b++;
2963                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2964                         if (cnt && con_is_visible(vc))
2965                                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
2966                         cnt = 0;
2967                         if (c == 8) {           /* backspace */
2968                                 bs(vc);
2969                                 start = (ushort *)vc->vc_pos;
2970                                 start_x = vc->state.x;
2971                                 continue;
2972                         }
2973                         if (c != 13)
2974                                 lf(vc);
2975                         cr(vc);
2976                         start = (ushort *)vc->vc_pos;
2977                         start_x = vc->state.x;
2978                         if (c == 10 || c == 13)
2979                                 continue;
2980                 }
2981                 vc_uniscr_putc(vc, c);
2982                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2983                 notify_write(vc, c);
2984                 cnt++;
2985                 if (vc->state.x == vc->vc_cols - 1) {
2986                         vc->vc_need_wrap = 1;
2987                 } else {
2988                         vc->vc_pos += 2;
2989                         vc->state.x++;
2990                 }
2991         }
2992         if (cnt && con_is_visible(vc))
2993                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
2994         set_cursor(vc);
2995         notify_update(vc);
2996
2997 quit:
2998         spin_unlock(&printing_lock);
2999 }
3000
3001 static struct tty_driver *vt_console_device(struct console *c, int *index)
3002 {
3003         *index = c->index ? c->index-1 : fg_console;
3004         return console_driver;
3005 }
3006
3007 static struct console vt_console_driver = {
3008         .name           = "tty",
3009         .write          = vt_console_print,
3010         .device         = vt_console_device,
3011         .unblank        = unblank_screen,
3012         .flags          = CON_PRINTBUFFER,
3013         .index          = -1,
3014 };
3015 #endif
3016
3017 /*
3018  *      Handling of Linux-specific VC ioctls
3019  */
3020
3021 /*
3022  * Generally a bit racy with respect to console_lock();.
3023  *
3024  * There are some functions which don't need it.
3025  *
3026  * There are some functions which can sleep for arbitrary periods
3027  * (paste_selection) but we don't need the lock there anyway.
3028  *
3029  * set_selection_user has locking, and definitely needs it
3030  */
3031
3032 int tioclinux(struct tty_struct *tty, unsigned long arg)
3033 {
3034         char type, data;
3035         char __user *p = (char __user *)arg;
3036         int lines;
3037         int ret;
3038
3039         if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3040                 return -EPERM;
3041         if (get_user(type, p))
3042                 return -EFAULT;
3043         ret = 0;
3044
3045         switch (type)
3046         {
3047                 case TIOCL_SETSEL:
3048                         ret = set_selection_user((struct tiocl_selection
3049                                                  __user *)(p+1), tty);
3050                         break;
3051                 case TIOCL_PASTESEL:
3052                         ret = paste_selection(tty);
3053                         break;
3054                 case TIOCL_UNBLANKSCREEN:
3055                         console_lock();
3056                         unblank_screen();
3057                         console_unlock();
3058                         break;
3059                 case TIOCL_SELLOADLUT:
3060                         console_lock();
3061                         ret = sel_loadlut(p);
3062                         console_unlock();
3063                         break;
3064                 case TIOCL_GETSHIFTSTATE:
3065
3066         /*
3067          * Make it possible to react to Shift+Mousebutton.
3068          * Note that 'shift_state' is an undocumented
3069          * kernel-internal variable; programs not closely
3070          * related to the kernel should not use this.
3071          */
3072                         data = vt_get_shift_state();
3073                         ret = put_user(data, p);
3074                         break;
3075                 case TIOCL_GETMOUSEREPORTING:
3076                         console_lock(); /* May be overkill */
3077                         data = mouse_reporting();
3078                         console_unlock();
3079                         ret = put_user(data, p);
3080                         break;
3081                 case TIOCL_SETVESABLANK:
3082                         console_lock();
3083                         ret = set_vesa_blanking(p);
3084                         console_unlock();
3085                         break;
3086                 case TIOCL_GETKMSGREDIRECT:
3087                         data = vt_get_kmsg_redirect();
3088                         ret = put_user(data, p);
3089                         break;
3090                 case TIOCL_SETKMSGREDIRECT:
3091                         if (!capable(CAP_SYS_ADMIN)) {
3092                                 ret = -EPERM;
3093                         } else {
3094                                 if (get_user(data, p+1))
3095                                         ret = -EFAULT;
3096                                 else
3097                                         vt_kmsg_redirect(data);
3098                         }
3099                         break;
3100                 case TIOCL_GETFGCONSOLE:
3101                         /* No locking needed as this is a transiently
3102                            correct return anyway if the caller hasn't
3103                            disabled switching */
3104                         ret = fg_console;
3105                         break;
3106                 case TIOCL_SCROLLCONSOLE:
3107                         if (get_user(lines, (s32 __user *)(p+4))) {
3108                                 ret = -EFAULT;
3109                         } else {
3110                                 /* Need the console lock here. Note that lots
3111                                    of other calls need fixing before the lock
3112                                    is actually useful ! */
3113                                 console_lock();
3114                                 scrollfront(vc_cons[fg_console].d, lines);
3115                                 console_unlock();
3116                                 ret = 0;
3117                         }
3118                         break;
3119                 case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
3120                         console_lock();
3121                         ignore_poke = 1;
3122                         do_blank_screen(0);
3123                         console_unlock();
3124                         break;
3125                 case TIOCL_BLANKEDSCREEN:
3126                         ret = console_blanked;
3127                         break;
3128                 default:
3129                         ret = -EINVAL;
3130                         break;
3131         }
3132         return ret;
3133 }
3134
3135 /*
3136  * /dev/ttyN handling
3137  */
3138
3139 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3140 {
3141         int     retval;
3142
3143         retval = do_con_write(tty, buf, count);
3144         con_flush_chars(tty);
3145
3146         return retval;
3147 }
3148
3149 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3150 {
3151         if (in_interrupt())
3152                 return 0;       /* n_r3964 calls put_char() from interrupt context */
3153         return do_con_write(tty, &ch, 1);
3154 }
3155
3156 static int con_write_room(struct tty_struct *tty)
3157 {
3158         if (tty->stopped)
3159                 return 0;
3160         return 32768;           /* No limit, really; we're not buffering */
3161 }
3162
3163 static int con_chars_in_buffer(struct tty_struct *tty)
3164 {
3165         return 0;               /* we're not buffering */
3166 }
3167
3168 /*
3169  * con_throttle and con_unthrottle are only used for
3170  * paste_selection(), which has to stuff in a large number of
3171  * characters...
3172  */
3173 static void con_throttle(struct tty_struct *tty)
3174 {
3175 }
3176
3177 static void con_unthrottle(struct tty_struct *tty)
3178 {
3179         struct vc_data *vc = tty->driver_data;
3180
3181         wake_up_interruptible(&vc->paste_wait);
3182 }
3183
3184 /*
3185  * Turn the Scroll-Lock LED on when the tty is stopped
3186  */
3187 static void con_stop(struct tty_struct *tty)
3188 {
3189         int console_num;
3190         if (!tty)
3191                 return;
3192         console_num = tty->index;
3193         if (!vc_cons_allocated(console_num))
3194                 return;
3195         vt_kbd_con_stop(console_num);
3196 }
3197
3198 /*
3199  * Turn the Scroll-Lock LED off when the console is started
3200  */
3201 static void con_start(struct tty_struct *tty)
3202 {
3203         int console_num;
3204         if (!tty)
3205                 return;
3206         console_num = tty->index;
3207         if (!vc_cons_allocated(console_num))
3208                 return;
3209         vt_kbd_con_start(console_num);
3210 }
3211
3212 static void con_flush_chars(struct tty_struct *tty)
3213 {
3214         struct vc_data *vc;
3215
3216         if (in_interrupt())     /* from flush_to_ldisc */
3217                 return;
3218
3219         /* if we race with con_close(), vt may be null */
3220         console_lock();
3221         vc = tty->driver_data;
3222         if (vc)
3223                 set_cursor(vc);
3224         console_unlock();
3225 }
3226
3227 /*
3228  * Allocate the console screen memory.
3229  */
3230 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3231 {
3232         unsigned int currcons = tty->index;
3233         struct vc_data *vc;
3234         int ret;
3235
3236         console_lock();
3237         ret = vc_allocate(currcons);
3238         if (ret)
3239                 goto unlock;
3240
3241         vc = vc_cons[currcons].d;
3242
3243         /* Still being freed */
3244         if (vc->port.tty) {
3245                 ret = -ERESTARTSYS;
3246                 goto unlock;
3247         }
3248
3249         ret = tty_port_install(&vc->port, driver, tty);
3250         if (ret)
3251                 goto unlock;
3252
3253         tty->driver_data = vc;
3254         vc->port.tty = tty;
3255         tty_port_get(&vc->port);
3256
3257         if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3258                 tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3259                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3260         }
3261         if (vc->vc_utf)
3262                 tty->termios.c_iflag |= IUTF8;
3263         else
3264                 tty->termios.c_iflag &= ~IUTF8;
3265 unlock:
3266         console_unlock();
3267         return ret;
3268 }
3269
3270 static int con_open(struct tty_struct *tty, struct file *filp)
3271 {
3272         /* everything done in install */
3273         return 0;
3274 }
3275
3276
3277 static void con_close(struct tty_struct *tty, struct file *filp)
3278 {
3279         /* Nothing to do - we defer to shutdown */
3280 }
3281
3282 static void con_shutdown(struct tty_struct *tty)
3283 {
3284         struct vc_data *vc = tty->driver_data;
3285         BUG_ON(vc == NULL);
3286         console_lock();
3287         vc->port.tty = NULL;
3288         console_unlock();
3289 }
3290
3291 static void con_cleanup(struct tty_struct *tty)
3292 {
3293         struct vc_data *vc = tty->driver_data;
3294
3295         tty_port_put(&vc->port);
3296 }
3297
3298 static int default_color           = 7; /* white */
3299 static int default_italic_color    = 2; // green (ASCII)
3300 static int default_underline_color = 3; // cyan (ASCII)
3301 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3302 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3303 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3304
3305 static void vc_init(struct vc_data *vc, unsigned int rows,
3306                     unsigned int cols, int do_clear)
3307 {
3308         int j, k ;
3309
3310         vc->vc_cols = cols;
3311         vc->vc_rows = rows;
3312         vc->vc_size_row = cols << 1;
3313         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3314
3315         set_origin(vc);
3316         vc->vc_pos = vc->vc_origin;
3317         reset_vc(vc);
3318         for (j=k=0; j<16; j++) {
3319                 vc->vc_palette[k++] = default_red[j] ;
3320                 vc->vc_palette[k++] = default_grn[j] ;
3321                 vc->vc_palette[k++] = default_blu[j] ;
3322         }
3323         vc->vc_def_color       = default_color;
3324         vc->vc_ulcolor         = default_underline_color;
3325         vc->vc_itcolor         = default_italic_color;
3326         vc->vc_halfcolor       = 0x08;   /* grey */
3327         init_waitqueue_head(&vc->paste_wait);
3328         reset_terminal(vc, do_clear);
3329 }
3330
3331 /*
3332  * This routine initializes console interrupts, and does nothing
3333  * else. If you want the screen to clear, call tty_write with
3334  * the appropriate escape-sequence.
3335  */
3336
3337 static int __init con_init(void)
3338 {
3339         const char *display_desc = NULL;
3340         struct vc_data *vc;
3341         unsigned int currcons = 0, i;
3342
3343         console_lock();
3344
3345         if (!conswitchp)
3346                 conswitchp = &dummy_con;
3347         display_desc = conswitchp->con_startup();
3348         if (!display_desc) {
3349                 fg_console = 0;
3350                 console_unlock();
3351                 return 0;
3352         }
3353
3354         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3355                 struct con_driver *con_driver = &registered_con_driver[i];
3356
3357                 if (con_driver->con == NULL) {
3358                         con_driver->con = conswitchp;
3359                         con_driver->desc = display_desc;
3360                         con_driver->flag = CON_DRIVER_FLAG_INIT;
3361                         con_driver->first = 0;
3362                         con_driver->last = MAX_NR_CONSOLES - 1;
3363                         break;
3364                 }
3365         }
3366
3367         for (i = 0; i < MAX_NR_CONSOLES; i++)
3368                 con_driver_map[i] = conswitchp;
3369
3370         if (blankinterval) {
3371                 blank_state = blank_normal_wait;
3372                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3373         }
3374
3375         for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3376                 vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3377                 INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3378                 tty_port_init(&vc->port);
3379                 visual_init(vc, currcons, 1);
3380                 vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3381                 vc_init(vc, vc->vc_rows, vc->vc_cols,
3382                         currcons || !vc->vc_sw->con_save_screen);
3383         }
3384         currcons = fg_console = 0;
3385         master_display_fg = vc = vc_cons[currcons].d;
3386         set_origin(vc);
3387         save_screen(vc);
3388         gotoxy(vc, vc->state.x, vc->state.y);
3389         csi_J(vc, 0);
3390         update_screen(vc);
3391         pr_info("Console: %s %s %dx%d\n",
3392                 vc->vc_can_do_color ? "colour" : "mono",
3393                 display_desc, vc->vc_cols, vc->vc_rows);
3394         printable = 1;
3395
3396         console_unlock();
3397
3398 #ifdef CONFIG_VT_CONSOLE
3399         register_console(&vt_console_driver);
3400 #endif
3401         return 0;
3402 }
3403 console_initcall(con_init);
3404
3405 static const struct tty_operations con_ops = {
3406         .install = con_install,
3407         .open = con_open,
3408         .close = con_close,
3409         .write = con_write,
3410         .write_room = con_write_room,
3411         .put_char = con_put_char,
3412         .flush_chars = con_flush_chars,
3413         .chars_in_buffer = con_chars_in_buffer,
3414         .ioctl = vt_ioctl,
3415 #ifdef CONFIG_COMPAT
3416         .compat_ioctl = vt_compat_ioctl,
3417 #endif
3418         .stop = con_stop,
3419         .start = con_start,
3420         .throttle = con_throttle,
3421         .unthrottle = con_unthrottle,
3422         .resize = vt_resize,
3423         .shutdown = con_shutdown,
3424         .cleanup = con_cleanup,
3425 };
3426
3427 static struct cdev vc0_cdev;
3428
3429 static ssize_t show_tty_active(struct device *dev,
3430                                 struct device_attribute *attr, char *buf)
3431 {
3432         return sprintf(buf, "tty%d\n", fg_console + 1);
3433 }
3434 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3435
3436 static struct attribute *vt_dev_attrs[] = {
3437         &dev_attr_active.attr,
3438         NULL
3439 };
3440
3441 ATTRIBUTE_GROUPS(vt_dev);
3442
3443 int __init vty_init(const struct file_operations *console_fops)
3444 {
3445         cdev_init(&vc0_cdev, console_fops);
3446         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3447             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3448                 panic("Couldn't register /dev/tty0 driver\n");
3449         tty0dev = device_create_with_groups(tty_class, NULL,
3450                                             MKDEV(TTY_MAJOR, 0), NULL,
3451                                             vt_dev_groups, "tty0");
3452         if (IS_ERR(tty0dev))
3453                 tty0dev = NULL;
3454
3455         vcs_init();
3456
3457         console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3458         if (!console_driver)
3459                 panic("Couldn't allocate console driver\n");
3460
3461         console_driver->name = "tty";
3462         console_driver->name_base = 1;
3463         console_driver->major = TTY_MAJOR;
3464         console_driver->minor_start = 1;
3465         console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3466         console_driver->init_termios = tty_std_termios;
3467         if (default_utf8)
3468                 console_driver->init_termios.c_iflag |= IUTF8;
3469         console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3470         tty_set_operations(console_driver, &con_ops);
3471         if (tty_register_driver(console_driver))
3472                 panic("Couldn't register console driver\n");
3473         kbd_init();
3474         console_map_init();
3475 #ifdef CONFIG_MDA_CONSOLE
3476         mda_console_init();
3477 #endif
3478         return 0;
3479 }
3480
3481 #ifndef VT_SINGLE_DRIVER
3482
3483 static struct class *vtconsole_class;
3484
3485 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3486                            int deflt)
3487 {
3488         struct module *owner = csw->owner;
3489         const char *desc = NULL;
3490         struct con_driver *con_driver;
3491         int i, j = -1, k = -1, retval = -ENODEV;
3492
3493         if (!try_module_get(owner))
3494                 return -ENODEV;
3495
3496         WARN_CONSOLE_UNLOCKED();
3497
3498         /* check if driver is registered */
3499         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3500                 con_driver = &registered_con_driver[i];
3501
3502                 if (con_driver->con == csw) {
3503                         desc = con_driver->desc;
3504                         retval = 0;
3505                         break;
3506                 }
3507         }
3508
3509         if (retval)
3510                 goto err;
3511
3512         if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3513                 csw->con_startup();
3514                 con_driver->flag |= CON_DRIVER_FLAG_INIT;
3515         }
3516
3517         if (deflt) {
3518                 if (conswitchp)
3519                         module_put(conswitchp->owner);
3520
3521                 __module_get(owner);
3522                 conswitchp = csw;
3523         }
3524
3525         first = max(first, con_driver->first);
3526         last = min(last, con_driver->last);
3527
3528         for (i = first; i <= last; i++) {
3529                 int old_was_color;
3530                 struct vc_data *vc = vc_cons[i].d;
3531
3532                 if (con_driver_map[i])
3533                         module_put(con_driver_map[i]->owner);
3534                 __module_get(owner);
3535                 con_driver_map[i] = csw;
3536
3537                 if (!vc || !vc->vc_sw)
3538                         continue;
3539
3540                 j = i;
3541
3542                 if (con_is_visible(vc)) {
3543                         k = i;
3544                         save_screen(vc);
3545                 }
3546
3547                 old_was_color = vc->vc_can_do_color;
3548                 vc->vc_sw->con_deinit(vc);
3549                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3550                 visual_init(vc, i, 0);
3551                 set_origin(vc);
3552                 update_attr(vc);
3553
3554                 /* If the console changed between mono <-> color, then
3555                  * the attributes in the screenbuf will be wrong.  The
3556                  * following resets all attributes to something sane.
3557                  */
3558                 if (old_was_color != vc->vc_can_do_color)
3559                         clear_buffer_attributes(vc);
3560         }
3561
3562         pr_info("Console: switching ");
3563         if (!deflt)
3564                 pr_cont("consoles %d-%d ", first + 1, last + 1);
3565         if (j >= 0) {
3566                 struct vc_data *vc = vc_cons[j].d;
3567
3568                 pr_cont("to %s %s %dx%d\n",
3569                         vc->vc_can_do_color ? "colour" : "mono",
3570                         desc, vc->vc_cols, vc->vc_rows);
3571
3572                 if (k >= 0) {
3573                         vc = vc_cons[k].d;
3574                         update_screen(vc);
3575                 }
3576         } else {
3577                 pr_cont("to %s\n", desc);
3578         }
3579
3580         retval = 0;
3581 err:
3582         module_put(owner);
3583         return retval;
3584 };
3585
3586
3587 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3588 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3589 {
3590         struct module *owner = csw->owner;
3591         const struct consw *defcsw = NULL;
3592         struct con_driver *con_driver = NULL, *con_back = NULL;
3593         int i, retval = -ENODEV;
3594
3595         if (!try_module_get(owner))
3596                 return -ENODEV;
3597
3598         WARN_CONSOLE_UNLOCKED();
3599
3600         /* check if driver is registered and if it is unbindable */
3601         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3602                 con_driver = &registered_con_driver[i];
3603
3604                 if (con_driver->con == csw &&
3605                     con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3606                         retval = 0;
3607                         break;
3608                 }
3609         }
3610
3611         if (retval)
3612                 goto err;
3613
3614         retval = -ENODEV;
3615
3616         /* check if backup driver exists */
3617         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3618                 con_back = &registered_con_driver[i];
3619
3620                 if (con_back->con && con_back->con != csw) {
3621                         defcsw = con_back->con;
3622                         retval = 0;
3623                         break;
3624                 }
3625         }
3626
3627         if (retval)
3628                 goto err;
3629
3630         if (!con_is_bound(csw))
3631                 goto err;
3632
3633         first = max(first, con_driver->first);
3634         last = min(last, con_driver->last);
3635
3636         for (i = first; i <= last; i++) {
3637                 if (con_driver_map[i] == csw) {
3638                         module_put(csw->owner);
3639                         con_driver_map[i] = NULL;
3640                 }
3641         }
3642
3643         if (!con_is_bound(defcsw)) {
3644                 const struct consw *defconsw = conswitchp;
3645
3646                 defcsw->con_startup();
3647                 con_back->flag |= CON_DRIVER_FLAG_INIT;
3648                 /*
3649                  * vgacon may change the default driver to point
3650                  * to dummycon, we restore it here...
3651                  */
3652                 conswitchp = defconsw;
3653         }
3654
3655         if (!con_is_bound(csw))
3656                 con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3657
3658         /* ignore return value, binding should not fail */
3659         do_bind_con_driver(defcsw, first, last, deflt);
3660 err:
3661         module_put(owner);
3662         return retval;
3663
3664 }
3665 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3666
3667 static int vt_bind(struct con_driver *con)
3668 {
3669         const struct consw *defcsw = NULL, *csw = NULL;
3670         int i, more = 1, first = -1, last = -1, deflt = 0;
3671
3672         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3673                 goto err;
3674
3675         csw = con->con;
3676
3677         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3678                 struct con_driver *con = &registered_con_driver[i];
3679
3680                 if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3681                         defcsw = con->con;
3682                         break;
3683                 }
3684         }
3685
3686         if (!defcsw)
3687                 goto err;
3688
3689         while (more) {
3690                 more = 0;
3691
3692                 for (i = con->first; i <= con->last; i++) {
3693                         if (con_driver_map[i] == defcsw) {
3694                                 if (first == -1)
3695                                         first = i;
3696                                 last = i;
3697                                 more = 1;
3698                         } else if (first != -1)
3699                                 break;
3700                 }
3701
3702                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3703                         deflt = 1;
3704
3705                 if (first != -1)
3706                         do_bind_con_driver(csw, first, last, deflt);
3707
3708                 first = -1;
3709                 last = -1;
3710                 deflt = 0;
3711         }
3712
3713 err:
3714         return 0;
3715 }
3716
3717 static int vt_unbind(struct con_driver *con)
3718 {
3719         const struct consw *csw = NULL;
3720         int i, more = 1, first = -1, last = -1, deflt = 0;
3721         int ret;
3722
3723         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3724                 goto err;
3725
3726         csw = con->con;
3727
3728         while (more) {
3729                 more = 0;
3730
3731                 for (i = con->first; i <= con->last; i++) {
3732                         if (con_driver_map[i] == csw) {
3733                                 if (first == -1)
3734                                         first = i;
3735                                 last = i;
3736                                 more = 1;
3737                         } else if (first != -1)
3738                                 break;
3739                 }
3740
3741                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3742                         deflt = 1;
3743
3744                 if (first != -1) {
3745                         ret = do_unbind_con_driver(csw, first, last, deflt);
3746                         if (ret != 0)
3747                                 return ret;
3748                 }
3749
3750                 first = -1;
3751                 last = -1;
3752                 deflt = 0;
3753         }
3754
3755 err:
3756         return 0;
3757 }
3758 #else
3759 static inline int vt_bind(struct con_driver *con)
3760 {
3761         return 0;
3762 }
3763 static inline int vt_unbind(struct con_driver *con)
3764 {
3765         return 0;
3766 }
3767 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3768
3769 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3770                           const char *buf, size_t count)
3771 {
3772         struct con_driver *con = dev_get_drvdata(dev);
3773         int bind = simple_strtoul(buf, NULL, 0);
3774
3775         console_lock();
3776
3777         if (bind)
3778                 vt_bind(con);
3779         else
3780                 vt_unbind(con);
3781
3782         console_unlock();
3783
3784         return count;
3785 }
3786
3787 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3788                          char *buf)
3789 {
3790         struct con_driver *con = dev_get_drvdata(dev);
3791         int bind;
3792
3793         console_lock();
3794         bind = con_is_bound(con->con);
3795         console_unlock();
3796
3797         return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3798 }
3799
3800 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3801                          char *buf)
3802 {
3803         struct con_driver *con = dev_get_drvdata(dev);
3804
3805         return snprintf(buf, PAGE_SIZE, "%s %s\n",
3806                         (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3807                          con->desc);
3808
3809 }
3810
3811 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3812 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3813
3814 static struct attribute *con_dev_attrs[] = {
3815         &dev_attr_bind.attr,
3816         &dev_attr_name.attr,
3817         NULL
3818 };
3819
3820 ATTRIBUTE_GROUPS(con_dev);
3821
3822 static int vtconsole_init_device(struct con_driver *con)
3823 {
3824         con->flag |= CON_DRIVER_FLAG_ATTR;
3825         return 0;
3826 }
3827
3828 static void vtconsole_deinit_device(struct con_driver *con)
3829 {
3830         con->flag &= ~CON_DRIVER_FLAG_ATTR;
3831 }
3832
3833 /**
3834  * con_is_bound - checks if driver is bound to the console
3835  * @csw: console driver
3836  *
3837  * RETURNS: zero if unbound, nonzero if bound
3838  *
3839  * Drivers can call this and if zero, they should release
3840  * all resources allocated on con_startup()
3841  */
3842 int con_is_bound(const struct consw *csw)
3843 {
3844         int i, bound = 0;
3845
3846         WARN_CONSOLE_UNLOCKED();
3847
3848         for (i = 0; i < MAX_NR_CONSOLES; i++) {
3849                 if (con_driver_map[i] == csw) {
3850                         bound = 1;
3851                         break;
3852                 }
3853         }
3854
3855         return bound;
3856 }
3857 EXPORT_SYMBOL(con_is_bound);
3858
3859 /**
3860  * con_is_visible - checks whether the current console is visible
3861  * @vc: virtual console
3862  *
3863  * RETURNS: zero if not visible, nonzero if visible
3864  */
3865 bool con_is_visible(const struct vc_data *vc)
3866 {
3867         WARN_CONSOLE_UNLOCKED();
3868
3869         return *vc->vc_display_fg == vc;
3870 }
3871 EXPORT_SYMBOL(con_is_visible);
3872
3873 /**
3874  * con_debug_enter - prepare the console for the kernel debugger
3875  * @sw: console driver
3876  *
3877  * Called when the console is taken over by the kernel debugger, this
3878  * function needs to save the current console state, then put the console
3879  * into a state suitable for the kernel debugger.
3880  *
3881  * RETURNS:
3882  * Zero on success, nonzero if a failure occurred when trying to prepare
3883  * the console for the debugger.
3884  */
3885 int con_debug_enter(struct vc_data *vc)
3886 {
3887         int ret = 0;
3888
3889         saved_fg_console = fg_console;
3890         saved_last_console = last_console;
3891         saved_want_console = want_console;
3892         saved_vc_mode = vc->vc_mode;
3893         saved_console_blanked = console_blanked;
3894         vc->vc_mode = KD_TEXT;
3895         console_blanked = 0;
3896         if (vc->vc_sw->con_debug_enter)
3897                 ret = vc->vc_sw->con_debug_enter(vc);
3898 #ifdef CONFIG_KGDB_KDB
3899         /* Set the initial LINES variable if it is not already set */
3900         if (vc->vc_rows < 999) {
3901                 int linecount;
3902                 char lns[4];
3903                 const char *setargs[3] = {
3904                         "set",
3905                         "LINES",
3906                         lns,
3907                 };
3908                 if (kdbgetintenv(setargs[0], &linecount)) {
3909                         snprintf(lns, 4, "%i", vc->vc_rows);
3910                         kdb_set(2, setargs);
3911                 }
3912         }
3913         if (vc->vc_cols < 999) {
3914                 int colcount;
3915                 char cols[4];
3916                 const char *setargs[3] = {
3917                         "set",
3918                         "COLUMNS",
3919                         cols,
3920                 };
3921                 if (kdbgetintenv(setargs[0], &colcount)) {
3922                         snprintf(cols, 4, "%i", vc->vc_cols);
3923                         kdb_set(2, setargs);
3924                 }
3925         }
3926 #endif /* CONFIG_KGDB_KDB */
3927         return ret;
3928 }
3929 EXPORT_SYMBOL_GPL(con_debug_enter);
3930
3931 /**
3932  * con_debug_leave - restore console state
3933  * @sw: console driver
3934  *
3935  * Restore the console state to what it was before the kernel debugger
3936  * was invoked.
3937  *
3938  * RETURNS:
3939  * Zero on success, nonzero if a failure occurred when trying to restore
3940  * the console.
3941  */
3942 int con_debug_leave(void)
3943 {
3944         struct vc_data *vc;
3945         int ret = 0;
3946
3947         fg_console = saved_fg_console;
3948         last_console = saved_last_console;
3949         want_console = saved_want_console;
3950         console_blanked = saved_console_blanked;
3951         vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3952
3953         vc = vc_cons[fg_console].d;
3954         if (vc->vc_sw->con_debug_leave)
3955                 ret = vc->vc_sw->con_debug_leave(vc);
3956         return ret;
3957 }
3958 EXPORT_SYMBOL_GPL(con_debug_leave);
3959
3960 static int do_register_con_driver(const struct consw *csw, int first, int last)
3961 {
3962         struct module *owner = csw->owner;
3963         struct con_driver *con_driver;
3964         const char *desc;
3965         int i, retval;
3966
3967         WARN_CONSOLE_UNLOCKED();
3968
3969         if (!try_module_get(owner))
3970                 return -ENODEV;
3971
3972         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3973                 con_driver = &registered_con_driver[i];
3974
3975                 /* already registered */
3976                 if (con_driver->con == csw) {
3977                         retval = -EBUSY;
3978                         goto err;
3979                 }
3980         }
3981
3982         desc = csw->con_startup();
3983         if (!desc) {
3984                 retval = -ENODEV;
3985                 goto err;
3986         }
3987
3988         retval = -EINVAL;
3989
3990         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3991                 con_driver = &registered_con_driver[i];
3992
3993                 if (con_driver->con == NULL &&
3994                     !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3995                         con_driver->con = csw;
3996                         con_driver->desc = desc;
3997                         con_driver->node = i;
3998                         con_driver->flag = CON_DRIVER_FLAG_MODULE |
3999                                            CON_DRIVER_FLAG_INIT;
4000                         con_driver->first = first;
4001                         con_driver->last = last;
4002                         retval = 0;
4003                         break;
4004                 }
4005         }
4006
4007         if (retval)
4008                 goto err;
4009
4010         con_driver->dev =
4011                 device_create_with_groups(vtconsole_class, NULL,
4012                                           MKDEV(0, con_driver->node),
4013                                           con_driver, con_dev_groups,
4014                                           "vtcon%i", con_driver->node);
4015         if (IS_ERR(con_driver->dev)) {
4016                 pr_warn("Unable to create device for %s; errno = %ld\n",
4017                         con_driver->desc, PTR_ERR(con_driver->dev));
4018                 con_driver->dev = NULL;
4019         } else {
4020                 vtconsole_init_device(con_driver);
4021         }
4022
4023 err:
4024         module_put(owner);
4025         return retval;
4026 }
4027
4028
4029 /**
4030  * do_unregister_con_driver - unregister console driver from console layer
4031  * @csw: console driver
4032  *
4033  * DESCRIPTION: All drivers that registers to the console layer must
4034  * call this function upon exit, or if the console driver is in a state
4035  * where it won't be able to handle console services, such as the
4036  * framebuffer console without loaded framebuffer drivers.
4037  *
4038  * The driver must unbind first prior to unregistration.
4039  */
4040 int do_unregister_con_driver(const struct consw *csw)
4041 {
4042         int i;
4043
4044         /* cannot unregister a bound driver */
4045         if (con_is_bound(csw))
4046                 return -EBUSY;
4047
4048         if (csw == conswitchp)
4049                 return -EINVAL;
4050
4051         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4052                 struct con_driver *con_driver = &registered_con_driver[i];
4053
4054                 if (con_driver->con == csw) {
4055                         /*
4056                          * Defer the removal of the sysfs entries since that
4057                          * will acquire the kernfs s_active lock and we can't
4058                          * acquire this lock while holding the console lock:
4059                          * the unbind sysfs entry imposes already the opposite
4060                          * order. Reset con already here to prevent any later
4061                          * lookup to succeed and mark this slot as zombie, so
4062                          * it won't get reused until we complete the removal
4063                          * in the deferred work.
4064                          */
4065                         con_driver->con = NULL;
4066                         con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4067                         schedule_work(&con_driver_unregister_work);
4068
4069                         return 0;
4070                 }
4071         }
4072
4073         return -ENODEV;
4074 }
4075 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4076
4077 static void con_driver_unregister_callback(struct work_struct *ignored)
4078 {
4079         int i;
4080
4081         console_lock();
4082
4083         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4084                 struct con_driver *con_driver = &registered_con_driver[i];
4085
4086                 if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4087                         continue;
4088
4089                 console_unlock();
4090
4091                 vtconsole_deinit_device(con_driver);
4092                 device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4093
4094                 console_lock();
4095
4096                 if (WARN_ON_ONCE(con_driver->con))
4097                         con_driver->con = NULL;
4098                 con_driver->desc = NULL;
4099                 con_driver->dev = NULL;
4100                 con_driver->node = 0;
4101                 WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4102                 con_driver->flag = 0;
4103                 con_driver->first = 0;
4104                 con_driver->last = 0;
4105         }
4106
4107         console_unlock();
4108 }
4109
4110 /*
4111  *      If we support more console drivers, this function is used
4112  *      when a driver wants to take over some existing consoles
4113  *      and become default driver for newly opened ones.
4114  *
4115  *      do_take_over_console is basically a register followed by bind
4116  */
4117 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4118 {
4119         int err;
4120
4121         err = do_register_con_driver(csw, first, last);
4122         /*
4123          * If we get an busy error we still want to bind the console driver
4124          * and return success, as we may have unbound the console driver
4125          * but not unregistered it.
4126          */
4127         if (err == -EBUSY)
4128                 err = 0;
4129         if (!err)
4130                 do_bind_con_driver(csw, first, last, deflt);
4131
4132         return err;
4133 }
4134 EXPORT_SYMBOL_GPL(do_take_over_console);
4135
4136
4137 /*
4138  * give_up_console is a wrapper to unregister_con_driver. It will only
4139  * work if driver is fully unbound.
4140  */
4141 void give_up_console(const struct consw *csw)
4142 {
4143         console_lock();
4144         do_unregister_con_driver(csw);
4145         console_unlock();
4146 }
4147
4148 static int __init vtconsole_class_init(void)
4149 {
4150         int i;
4151
4152         vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4153         if (IS_ERR(vtconsole_class)) {
4154                 pr_warn("Unable to create vt console class; errno = %ld\n",
4155                         PTR_ERR(vtconsole_class));
4156                 vtconsole_class = NULL;
4157         }
4158
4159         /* Add system drivers to sysfs */
4160         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4161                 struct con_driver *con = &registered_con_driver[i];
4162
4163                 if (con->con && !con->dev) {
4164                         con->dev =
4165                                 device_create_with_groups(vtconsole_class, NULL,
4166                                                           MKDEV(0, con->node),
4167                                                           con, con_dev_groups,
4168                                                           "vtcon%i", con->node);
4169
4170                         if (IS_ERR(con->dev)) {
4171                                 pr_warn("Unable to create device for %s; errno = %ld\n",
4172                                         con->desc, PTR_ERR(con->dev));
4173                                 con->dev = NULL;
4174                         } else {
4175                                 vtconsole_init_device(con);
4176                         }
4177                 }
4178         }
4179
4180         return 0;
4181 }
4182 postcore_initcall(vtconsole_class_init);
4183
4184 #endif
4185
4186 /*
4187  *      Screen blanking
4188  */
4189
4190 static int set_vesa_blanking(char __user *p)
4191 {
4192         unsigned int mode;
4193
4194         if (get_user(mode, p + 1))
4195                 return -EFAULT;
4196
4197         vesa_blank_mode = (mode < 4) ? mode : 0;
4198         return 0;
4199 }
4200
4201 void do_blank_screen(int entering_gfx)
4202 {
4203         struct vc_data *vc = vc_cons[fg_console].d;
4204         int i;
4205
4206         might_sleep();
4207
4208         WARN_CONSOLE_UNLOCKED();
4209
4210         if (console_blanked) {
4211                 if (blank_state == blank_vesa_wait) {
4212                         blank_state = blank_off;
4213                         vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4214                 }
4215                 return;
4216         }
4217
4218         /* entering graphics mode? */
4219         if (entering_gfx) {
4220                 hide_cursor(vc);
4221                 save_screen(vc);
4222                 vc->vc_sw->con_blank(vc, -1, 1);
4223                 console_blanked = fg_console + 1;
4224                 blank_state = blank_off;
4225                 set_origin(vc);
4226                 return;
4227         }
4228
4229         blank_state = blank_off;
4230
4231         /* don't blank graphics */
4232         if (vc->vc_mode != KD_TEXT) {
4233                 console_blanked = fg_console + 1;
4234                 return;
4235         }
4236
4237         hide_cursor(vc);
4238         del_timer_sync(&console_timer);
4239         blank_timer_expired = 0;
4240
4241         save_screen(vc);
4242         /* In case we need to reset origin, blanking hook returns 1 */
4243         i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4244         console_blanked = fg_console + 1;
4245         if (i)
4246                 set_origin(vc);
4247
4248         if (console_blank_hook && console_blank_hook(1))
4249                 return;
4250
4251         if (vesa_off_interval && vesa_blank_mode) {
4252                 blank_state = blank_vesa_wait;
4253                 mod_timer(&console_timer, jiffies + vesa_off_interval);
4254         }
4255         vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4256 }
4257 EXPORT_SYMBOL(do_blank_screen);
4258
4259 /*
4260  * Called by timer as well as from vt_console_driver
4261  */
4262 void do_unblank_screen(int leaving_gfx)
4263 {
4264         struct vc_data *vc;
4265
4266         /* This should now always be called from a "sane" (read: can schedule)
4267          * context for the sake of the low level drivers, except in the special
4268          * case of oops_in_progress
4269          */
4270         if (!oops_in_progress)
4271                 might_sleep();
4272
4273         WARN_CONSOLE_UNLOCKED();
4274
4275         ignore_poke = 0;
4276         if (!console_blanked)
4277                 return;
4278         if (!vc_cons_allocated(fg_console)) {
4279                 /* impossible */
4280                 pr_warn("unblank_screen: tty %d not allocated ??\n",
4281                         fg_console + 1);
4282                 return;
4283         }
4284         vc = vc_cons[fg_console].d;
4285         if (vc->vc_mode != KD_TEXT)
4286                 return; /* but leave console_blanked != 0 */
4287
4288         if (blankinterval) {
4289                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4290                 blank_state = blank_normal_wait;
4291         }
4292
4293         console_blanked = 0;
4294         if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4295                 /* Low-level driver cannot restore -> do it ourselves */
4296                 update_screen(vc);
4297         if (console_blank_hook)
4298                 console_blank_hook(0);
4299         set_palette(vc);
4300         set_cursor(vc);
4301         vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4302 }
4303 EXPORT_SYMBOL(do_unblank_screen);
4304
4305 /*
4306  * This is called by the outside world to cause a forced unblank, mostly for
4307  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4308  * call it with 1 as an argument and so force a mode restore... that may kill
4309  * X or at least garbage the screen but would also make the Oops visible...
4310  */
4311 void unblank_screen(void)
4312 {
4313         do_unblank_screen(0);
4314 }
4315
4316 /*
4317  * We defer the timer blanking to work queue so it can take the console mutex
4318  * (console operations can still happen at irq time, but only from printk which
4319  * has the console mutex. Not perfect yet, but better than no locking
4320  */
4321 static void blank_screen_t(struct timer_list *unused)
4322 {
4323         blank_timer_expired = 1;
4324         schedule_work(&console_work);
4325 }
4326
4327 void poke_blanked_console(void)
4328 {
4329         WARN_CONSOLE_UNLOCKED();
4330
4331         /* Add this so we quickly catch whoever might call us in a non
4332          * safe context. Nowadays, unblank_screen() isn't to be called in
4333          * atomic contexts and is allowed to schedule (with the special case
4334          * of oops_in_progress, but that isn't of any concern for this
4335          * function. --BenH.
4336          */
4337         might_sleep();
4338
4339         /* This isn't perfectly race free, but a race here would be mostly harmless,
4340          * at worse, we'll do a spurrious blank and it's unlikely
4341          */
4342         del_timer(&console_timer);
4343         blank_timer_expired = 0;
4344
4345         if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4346                 return;
4347         if (console_blanked)
4348                 unblank_screen();
4349         else if (blankinterval) {
4350                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4351                 blank_state = blank_normal_wait;
4352         }
4353 }
4354
4355 /*
4356  *      Palettes
4357  */
4358
4359 static void set_palette(struct vc_data *vc)
4360 {
4361         WARN_CONSOLE_UNLOCKED();
4362
4363         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4364                 vc->vc_sw->con_set_palette(vc, color_table);
4365 }
4366
4367 /*
4368  * Load palette into the DAC registers. arg points to a colour
4369  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4370  */
4371
4372 int con_set_cmap(unsigned char __user *arg)
4373 {
4374         int i, j, k;
4375         unsigned char colormap[3*16];
4376
4377         if (copy_from_user(colormap, arg, sizeof(colormap)))
4378                 return -EFAULT;
4379
4380         console_lock();
4381         for (i = k = 0; i < 16; i++) {
4382                 default_red[i] = colormap[k++];
4383                 default_grn[i] = colormap[k++];
4384                 default_blu[i] = colormap[k++];
4385         }
4386         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4387                 if (!vc_cons_allocated(i))
4388                         continue;
4389                 for (j = k = 0; j < 16; j++) {
4390                         vc_cons[i].d->vc_palette[k++] = default_red[j];
4391                         vc_cons[i].d->vc_palette[k++] = default_grn[j];
4392                         vc_cons[i].d->vc_palette[k++] = default_blu[j];
4393                 }
4394                 set_palette(vc_cons[i].d);
4395         }
4396         console_unlock();
4397
4398         return 0;
4399 }
4400
4401 int con_get_cmap(unsigned char __user *arg)
4402 {
4403         int i, k;
4404         unsigned char colormap[3*16];
4405
4406         console_lock();
4407         for (i = k = 0; i < 16; i++) {
4408                 colormap[k++] = default_red[i];
4409                 colormap[k++] = default_grn[i];
4410                 colormap[k++] = default_blu[i];
4411         }
4412         console_unlock();
4413
4414         if (copy_to_user(arg, colormap, sizeof(colormap)))
4415                 return -EFAULT;
4416
4417         return 0;
4418 }
4419
4420 void reset_palette(struct vc_data *vc)
4421 {
4422         int j, k;
4423         for (j=k=0; j<16; j++) {
4424                 vc->vc_palette[k++] = default_red[j];
4425                 vc->vc_palette[k++] = default_grn[j];
4426                 vc->vc_palette[k++] = default_blu[j];
4427         }
4428         set_palette(vc);
4429 }
4430
4431 /*
4432  *  Font switching
4433  *
4434  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4435  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4436  *  depending on width) reserved for each character which is kinda wasty, but
4437  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4438  *  is up to the actual low-level console-driver convert data into its favorite
4439  *  format (maybe we should add a `fontoffset' field to the `display'
4440  *  structure so we won't have to convert the fontdata all the time.
4441  *  /Jes
4442  */
4443
4444 #define max_font_size 65536
4445
4446 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4447 {
4448         struct console_font font;
4449         int rc = -EINVAL;
4450         int c;
4451
4452         if (op->data) {
4453                 font.data = kmalloc(max_font_size, GFP_KERNEL);
4454                 if (!font.data)
4455                         return -ENOMEM;
4456         } else
4457                 font.data = NULL;
4458
4459         console_lock();
4460         if (vc->vc_mode != KD_TEXT)
4461                 rc = -EINVAL;
4462         else if (vc->vc_sw->con_font_get)
4463                 rc = vc->vc_sw->con_font_get(vc, &font);
4464         else
4465                 rc = -ENOSYS;
4466         console_unlock();
4467
4468         if (rc)
4469                 goto out;
4470
4471         c = (font.width+7)/8 * 32 * font.charcount;
4472
4473         if (op->data && font.charcount > op->charcount)
4474                 rc = -ENOSPC;
4475         if (!(op->flags & KD_FONT_FLAG_OLD)) {
4476                 if (font.width > op->width || font.height > op->height)
4477                         rc = -ENOSPC;
4478         } else {
4479                 if (font.width != 8)
4480                         rc = -EIO;
4481                 else if ((op->height && font.height > op->height) ||
4482                          font.height > 32)
4483                         rc = -ENOSPC;
4484         }
4485         if (rc)
4486                 goto out;
4487
4488         op->height = font.height;
4489         op->width = font.width;
4490         op->charcount = font.charcount;
4491
4492         if (op->data && copy_to_user(op->data, font.data, c))
4493                 rc = -EFAULT;
4494
4495 out:
4496         kfree(font.data);
4497         return rc;
4498 }
4499
4500 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4501 {
4502         struct console_font font;
4503         int rc = -EINVAL;
4504         int size;
4505
4506         if (vc->vc_mode != KD_TEXT)
4507                 return -EINVAL;
4508         if (!op->data)
4509                 return -EINVAL;
4510         if (op->charcount > 512)
4511                 return -EINVAL;
4512         if (op->width <= 0 || op->width > 32 || op->height > 32)
4513                 return -EINVAL;
4514         size = (op->width+7)/8 * 32 * op->charcount;
4515         if (size > max_font_size)
4516                 return -ENOSPC;
4517
4518         font.data = memdup_user(op->data, size);
4519         if (IS_ERR(font.data))
4520                 return PTR_ERR(font.data);
4521
4522         if (!op->height) {              /* Need to guess font height [compat] */
4523                 int h, i;
4524                 u8 *charmap = font.data;
4525
4526                 /*
4527                  * If from KDFONTOP ioctl, don't allow things which can be done
4528                  * in userland,so that we can get rid of this soon
4529                  */
4530                 if (!(op->flags & KD_FONT_FLAG_OLD)) {
4531                         kfree(font.data);
4532                         return -EINVAL;
4533                 }
4534
4535                 for (h = 32; h > 0; h--)
4536                         for (i = 0; i < op->charcount; i++)
4537                                 if (charmap[32*i+h-1])
4538                                         goto nonzero;
4539
4540                 kfree(font.data);
4541                 return -EINVAL;
4542
4543         nonzero:
4544                 op->height = h;
4545         }
4546
4547         font.charcount = op->charcount;
4548         font.width = op->width;
4549         font.height = op->height;
4550
4551         console_lock();
4552         if (vc->vc_mode != KD_TEXT)
4553                 rc = -EINVAL;
4554         else if (vc->vc_sw->con_font_set)
4555                 rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4556         else
4557                 rc = -ENOSYS;
4558         console_unlock();
4559         kfree(font.data);
4560         return rc;
4561 }
4562
4563 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4564 {
4565         struct console_font font = {.width = op->width, .height = op->height};
4566         char name[MAX_FONT_NAME];
4567         char *s = name;
4568         int rc;
4569
4570
4571         if (!op->data)
4572                 s = NULL;
4573         else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4574                 return -EFAULT;
4575         else
4576                 name[MAX_FONT_NAME - 1] = 0;
4577
4578         console_lock();
4579         if (vc->vc_mode != KD_TEXT) {
4580                 console_unlock();
4581                 return -EINVAL;
4582         }
4583         if (vc->vc_sw->con_font_default)
4584                 rc = vc->vc_sw->con_font_default(vc, &font, s);
4585         else
4586                 rc = -ENOSYS;
4587         console_unlock();
4588         if (!rc) {
4589                 op->width = font.width;
4590                 op->height = font.height;
4591         }
4592         return rc;
4593 }
4594
4595 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4596 {
4597         int con = op->height;
4598         int rc;
4599
4600
4601         console_lock();
4602         if (vc->vc_mode != KD_TEXT)
4603                 rc = -EINVAL;
4604         else if (!vc->vc_sw->con_font_copy)
4605                 rc = -ENOSYS;
4606         else if (con < 0 || !vc_cons_allocated(con))
4607                 rc = -ENOTTY;
4608         else if (con == vc->vc_num)     /* nothing to do */
4609                 rc = 0;
4610         else
4611                 rc = vc->vc_sw->con_font_copy(vc, con);
4612         console_unlock();
4613         return rc;
4614 }
4615
4616 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4617 {
4618         switch (op->op) {
4619         case KD_FONT_OP_SET:
4620                 return con_font_set(vc, op);
4621         case KD_FONT_OP_GET:
4622                 return con_font_get(vc, op);
4623         case KD_FONT_OP_SET_DEFAULT:
4624                 return con_font_default(vc, op);
4625         case KD_FONT_OP_COPY:
4626                 return con_font_copy(vc, op);
4627         }
4628         return -ENOSYS;
4629 }
4630
4631 /*
4632  *      Interface exported to selection and vcs.
4633  */
4634
4635 /* used by selection */
4636 u16 screen_glyph(struct vc_data *vc, int offset)
4637 {
4638         u16 w = scr_readw(screenpos(vc, offset, 1));
4639         u16 c = w & 0xff;
4640
4641         if (w & vc->vc_hi_font_mask)
4642                 c |= 0x100;
4643         return c;
4644 }
4645 EXPORT_SYMBOL_GPL(screen_glyph);
4646
4647 u32 screen_glyph_unicode(struct vc_data *vc, int n)
4648 {
4649         struct uni_screen *uniscr = get_vc_uniscr(vc);
4650
4651         if (uniscr)
4652                 return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4653         return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4654 }
4655 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4656
4657 /* used by vcs - note the word offset */
4658 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4659 {
4660         return screenpos(vc, 2 * w_offset, viewed);
4661 }
4662 EXPORT_SYMBOL_GPL(screen_pos);
4663
4664 void getconsxy(struct vc_data *vc, unsigned char *p)
4665 {
4666         /* clamp values if they don't fit */
4667         p[0] = min(vc->state.x, 0xFFu);
4668         p[1] = min(vc->state.y, 0xFFu);
4669 }
4670
4671 void putconsxy(struct vc_data *vc, unsigned char *p)
4672 {
4673         hide_cursor(vc);
4674         gotoxy(vc, p[0], p[1]);
4675         set_cursor(vc);
4676 }
4677
4678 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4679 {
4680         if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4681                 return softcursor_original;
4682         return scr_readw(org);
4683 }
4684
4685 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4686 {
4687         scr_writew(val, org);
4688         if ((unsigned long)org == vc->vc_pos) {
4689                 softcursor_original = -1;
4690                 add_softcursor(vc);
4691         }
4692 }
4693
4694 void vcs_scr_updated(struct vc_data *vc)
4695 {
4696         notify_update(vc);
4697 }
4698
4699 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4700                 unsigned int rolled_over, void *base, unsigned int size)
4701 {
4702         unsigned long ubase = (unsigned long)base;
4703         ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4704         ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4705         ptrdiff_t origin = (void *)c->vc_origin - base;
4706         int margin = c->vc_size_row * 4;
4707         int from, wrap, from_off, avail;
4708
4709         /* Turn scrollback off */
4710         if (!lines) {
4711                 c->vc_visible_origin = c->vc_origin;
4712                 return;
4713         }
4714
4715         /* Do we have already enough to allow jumping from 0 to the end? */
4716         if (rolled_over > scr_end + margin) {
4717                 from = scr_end;
4718                 wrap = rolled_over + c->vc_size_row;
4719         } else {
4720                 from = 0;
4721                 wrap = size;
4722         }
4723
4724         from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4725         avail = (origin - from + wrap) % wrap;
4726
4727         /* Only a little piece would be left? Show all incl. the piece! */
4728         if (avail < 2 * margin)
4729                 margin = 0;
4730         if (from_off < margin)
4731                 from_off = 0;
4732         if (from_off > avail - margin)
4733                 from_off = avail;
4734
4735         c->vc_visible_origin = ubase + (from + from_off) % wrap;
4736 }
4737 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4738
4739 /*
4740  *      Visible symbols for modules
4741  */
4742
4743 EXPORT_SYMBOL(color_table);
4744 EXPORT_SYMBOL(default_red);
4745 EXPORT_SYMBOL(default_grn);
4746 EXPORT_SYMBOL(default_blu);
4747 EXPORT_SYMBOL(update_region);
4748 EXPORT_SYMBOL(redraw_screen);
4749 EXPORT_SYMBOL(vc_resize);
4750 EXPORT_SYMBOL(fg_console);
4751 EXPORT_SYMBOL(console_blank_hook);
4752 EXPORT_SYMBOL(console_blanked);
4753 EXPORT_SYMBOL(vc_cons);
4754 EXPORT_SYMBOL(global_cursor_default);
4755 #ifndef VT_SINGLE_DRIVER
4756 EXPORT_SYMBOL(give_up_console);
4757 #endif