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 /*
 131  * Here is the default bell parameters: 750HZ, 1/8th of a second
 132  */
 133 #define DEFAULT_BELL_PITCH      750
 134 #define DEFAULT_BELL_DURATION   (HZ/8)
 135 #define DEFAULT_CURSOR_BLINK_MS 200
 136
 137 struct vc vc_cons [MAX_NR_CONSOLES];
 138
 139 #ifndef VT_SINGLE_DRIVER
 140 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
 141 #endif
 142
 143 static int con_open(struct tty_struct *, struct file *);
 144 static void vc_init(struct vc_data *vc, unsigned int rows,
 145                     unsigned int cols, int do_clear);
 146 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
 147 static void save_cur(struct vc_data *vc);
 148 static void reset_terminal(struct vc_data *vc, int do_clear);
 149 static void con_flush_chars(struct tty_struct *tty);
 150 static int set_vesa_blanking(char __user *p);
 151 static void set_cursor(struct vc_data *vc);
 152 static void hide_cursor(struct vc_data *vc);
 153 static void console_callback(struct work_struct *ignored);
 154 static void con_driver_unregister_callback(struct work_struct *ignored);
 155 static void blank_screen_t(struct timer_list *unused);
 156 static void set_palette(struct vc_data *vc);
 157
 158 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 159
 160 static int printable;           /* Is console ready for printing? */
 161 int default_utf8 = true;
 162 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 163 int global_cursor_default = -1;
 164 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
 165
 166 static int cur_default = CUR_UNDERLINE;
 167 module_param(cur_default, int, S_IRUGO | S_IWUSR);
 168
 169 /*
 170  * ignore_poke: don't unblank the screen when things are typed.  This is
 171  * mainly for the privacy of braille terminal users.
 172  */
 173 static int ignore_poke;
 174
 175 int do_poke_blanked_console;
 176 int console_blanked;
 177
 178 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
 179 static int vesa_off_interval;
 180 static int blankinterval;
 181 core_param(consoleblank, blankinterval, int, 0444);
 182
 183 static DECLARE_WORK(console_work, console_callback);
 184 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
 185
 186 /*
 187  * fg_console is the current virtual console,
 188  * last_console is the last used one,
 189  * want_console is the console we want to switch to,
 190  * saved_* variants are for save/restore around kernel debugger enter/leave
 191  */
 192 int fg_console;
 193 int last_console;
 194 int want_console = -1;
 195 static int saved_fg_console;
 196 static int saved_last_console;
 197 static int saved_want_console;
 198 static int saved_vc_mode;
 199 static int saved_console_blanked;
 200
 201 /*
 202  * For each existing display, we have a pointer to console currently visible
 203  * on that display, allowing consoles other than fg_console to be refreshed
 204  * appropriately. Unless the low-level driver supplies its own display_fg
 205  * variable, we use this one for the "master display".
 206  */
 207 static struct vc_data *master_display_fg;
 208
 209 /*
 210  * Unfortunately, we need to delay tty echo when we're currently writing to the
 211  * console since the code is (and always was) not re-entrant, so we schedule
 212  * all flip requests to process context with schedule-task() and run it from
 213  * console_callback().
 214  */
 215
 216 /*
 217  * For the same reason, we defer scrollback to the console callback.
 218  */
 219 static int scrollback_delta;
 220
 221 /*
 222  * Hook so that the power management routines can (un)blank
 223  * the console on our behalf.
 224  */
 225 int (*console_blank_hook)(int);
 226
 227 static DEFINE_TIMER(console_timer, blank_screen_t);
 228 static int blank_state;
 229 static int blank_timer_expired;
 230 enum {
 231         blank_off = 0,
 232         blank_normal_wait,
 233         blank_vesa_wait,
 234 };
 235
 236 /*
 237  * /sys/class/tty/tty0/
 238  *
 239  * the attribute 'active' contains the name of the current vc
 240  * console and it supports poll() to detect vc switches
 241  */
 242 static struct device *tty0dev;
 243
 244 /*
 245  * Notifier list for console events.
 246  */
 247 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
 248
 249 int register_vt_notifier(struct notifier_block *nb)
 250 {
 251         return atomic_notifier_chain_register(&vt_notifier_list, nb);
 252 }
 253 EXPORT_SYMBOL_GPL(register_vt_notifier);
 254
 255 int unregister_vt_notifier(struct notifier_block *nb)
 256 {
 257         return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
 258 }
 259 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
 260
 261 static void notify_write(struct vc_data *vc, unsigned int unicode)
 262 {
 263         struct vt_notifier_param param = { .vc = vc, .c = unicode };
 264         atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
 265 }
 266
 267 static void notify_update(struct vc_data *vc)
 268 {
 269         struct vt_notifier_param param = { .vc = vc };
 270         atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
 271 }
 272 /*
 273  *      Low-Level Functions
 274  */
 275
 276 static inline bool con_is_fg(const struct vc_data *vc)
 277 {
 278         return vc->vc_num == fg_console;
 279 }
 280
 281 static inline bool con_should_update(const struct vc_data *vc)
 282 {
 283         return con_is_visible(vc) && !console_blanked;
 284 }
 285
 286 static inline unsigned short *screenpos(const struct vc_data *vc, int offset,
 287                 bool viewed)
 288 {
 289         unsigned short *p;
 290
 291         if (!viewed)
 292                 p = (unsigned short *)(vc->vc_origin + offset);
 293         else if (!vc->vc_sw->con_screen_pos)
 294                 p = (unsigned short *)(vc->vc_visible_origin + offset);
 295         else
 296                 p = vc->vc_sw->con_screen_pos(vc, offset);
 297         return p;
 298 }
 299
 300 /* Called  from the keyboard irq path.. */
 301 static inline void scrolldelta(int lines)
 302 {
 303         /* FIXME */
 304         /* scrolldelta needs some kind of consistency lock, but the BKL was
 305            and still is not protecting versus the scheduled back end */
 306         scrollback_delta += lines;
 307         schedule_console_callback();
 308 }
 309
 310 void schedule_console_callback(void)
 311 {
 312         schedule_work(&console_work);
 313 }
 314
 315 /*
 316  * Code to manage unicode-based screen buffers
 317  */
 318
 319 #ifdef NO_VC_UNI_SCREEN
 320 /* this disables and optimizes related code away at compile time */
 321 #define get_vc_uniscr(vc) NULL
 322 #else
 323 #define get_vc_uniscr(vc) vc->vc_uni_screen
 324 #endif
 325
 326 #define VC_UNI_SCREEN_DEBUG 0
 327
 328 typedef uint32_t char32_t;
 329
 330 /*
 331  * Our screen buffer is preceded by an array of line pointers so that
 332  * scrolling only implies some pointer shuffling.
 333  */
 334 struct uni_screen {
 335         char32_t *lines[0];
 336 };
 337
 338 static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
 339 {
 340         struct uni_screen *uniscr;
 341         void *p;
 342         unsigned int memsize, i;
 343
 344         /* allocate everything in one go */
 345         memsize = cols * rows * sizeof(char32_t);
 346         memsize += rows * sizeof(char32_t *);
 347         p = vmalloc(memsize);
 348         if (!p)
 349                 return NULL;
 350
 351         /* initial line pointers */
 352         uniscr = p;
 353         p = uniscr->lines + rows;
 354         for (i = 0; i < rows; i++) {
 355                 uniscr->lines[i] = p;
 356                 p += cols * sizeof(char32_t);
 357         }
 358         return uniscr;
 359 }
 360
 361 static void vc_uniscr_free(struct uni_screen *uniscr)
 362 {
 363         vfree(uniscr);
 364 }
 365
 366 static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
 367 {
 368         vc_uniscr_free(vc->vc_uni_screen);
 369         vc->vc_uni_screen = new_uniscr;
 370 }
 371
 372 static void vc_uniscr_putc(struct vc_data *vc, char32_t uc)
 373 {
 374         struct uni_screen *uniscr = get_vc_uniscr(vc);
 375
 376         if (uniscr)
 377                 uniscr->lines[vc->state.y][vc->state.x] = uc;
 378 }
 379
 380 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
 381 {
 382         struct uni_screen *uniscr = get_vc_uniscr(vc);
 383
 384         if (uniscr) {
 385                 char32_t *ln = uniscr->lines[vc->state.y];
 386                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 387
 388                 memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
 389                 memset32(&ln[x], ' ', nr);
 390         }
 391 }
 392
 393 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
 394 {
 395         struct uni_screen *uniscr = get_vc_uniscr(vc);
 396
 397         if (uniscr) {
 398                 char32_t *ln = uniscr->lines[vc->state.y];
 399                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 400
 401                 memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
 402                 memset32(&ln[cols - nr], ' ', nr);
 403         }
 404 }
 405
 406 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
 407                                  unsigned int nr)
 408 {
 409         struct uni_screen *uniscr = get_vc_uniscr(vc);
 410
 411         if (uniscr) {
 412                 char32_t *ln = uniscr->lines[vc->state.y];
 413
 414                 memset32(&ln[x], ' ', nr);
 415         }
 416 }
 417
 418 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
 419                                   unsigned int nr)
 420 {
 421         struct uni_screen *uniscr = get_vc_uniscr(vc);
 422
 423         if (uniscr) {
 424                 unsigned int cols = vc->vc_cols;
 425
 426                 while (nr--)
 427                         memset32(uniscr->lines[y++], ' ', cols);
 428         }
 429 }
 430
 431 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 432                              enum con_scroll dir, unsigned int nr)
 433 {
 434         struct uni_screen *uniscr = get_vc_uniscr(vc);
 435
 436         if (uniscr) {
 437                 unsigned int i, j, k, sz, d, clear;
 438
 439                 sz = b - t;
 440                 clear = b - nr;
 441                 d = nr;
 442                 if (dir == SM_DOWN) {
 443                         clear = t;
 444                         d = sz - nr;
 445                 }
 446                 for (i = 0; i < gcd(d, sz); i++) {
 447                         char32_t *tmp = uniscr->lines[t + i];
 448                         j = i;
 449                         while (1) {
 450                                 k = j + d;
 451                                 if (k >= sz)
 452                                         k -= sz;
 453                                 if (k == i)
 454                                         break;
 455                                 uniscr->lines[t + j] = uniscr->lines[t + k];
 456                                 j = k;
 457                         }
 458                         uniscr->lines[t + j] = tmp;
 459                 }
 460                 vc_uniscr_clear_lines(vc, clear, nr);
 461         }
 462 }
 463
 464 static void vc_uniscr_copy_area(struct uni_screen *dst,
 465                                 unsigned int dst_cols,
 466                                 unsigned int dst_rows,
 467                                 struct uni_screen *src,
 468                                 unsigned int src_cols,
 469                                 unsigned int src_top_row,
 470                                 unsigned int src_bot_row)
 471 {
 472         unsigned int dst_row = 0;
 473
 474         if (!dst)
 475                 return;
 476
 477         while (src_top_row < src_bot_row) {
 478                 char32_t *src_line = src->lines[src_top_row];
 479                 char32_t *dst_line = dst->lines[dst_row];
 480
 481                 memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
 482                 if (dst_cols - src_cols)
 483                         memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
 484                 src_top_row++;
 485                 dst_row++;
 486         }
 487         while (dst_row < dst_rows) {
 488                 char32_t *dst_line = dst->lines[dst_row];
 489
 490                 memset32(dst_line, ' ', dst_cols);
 491                 dst_row++;
 492         }
 493 }
 494
 495 /*
 496  * Called from vcs_read() to make sure unicode screen retrieval is possible.
 497  * This will initialize the unicode screen buffer if not already done.
 498  * This returns 0 if OK, or a negative error code otherwise.
 499  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
 500  */
 501 int vc_uniscr_check(struct vc_data *vc)
 502 {
 503         struct uni_screen *uniscr;
 504         unsigned short *p;
 505         int x, y, mask;
 506
 507         if (__is_defined(NO_VC_UNI_SCREEN))
 508                 return -EOPNOTSUPP;
 509
 510         WARN_CONSOLE_UNLOCKED();
 511
 512         if (!vc->vc_utf)
 513                 return -ENODATA;
 514
 515         if (vc->vc_uni_screen)
 516                 return 0;
 517
 518         uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
 519         if (!uniscr)
 520                 return -ENOMEM;
 521
 522         /*
 523          * Let's populate it initially with (imperfect) reverse translation.
 524          * This is the next best thing we can do short of having it enabled
 525          * from the start even when no users rely on this functionality. True
 526          * unicode content will be available after a complete screen refresh.
 527          */
 528         p = (unsigned short *)vc->vc_origin;
 529         mask = vc->vc_hi_font_mask | 0xff;
 530         for (y = 0; y < vc->vc_rows; y++) {
 531                 char32_t *line = uniscr->lines[y];
 532                 for (x = 0; x < vc->vc_cols; x++) {
 533                         u16 glyph = scr_readw(p++) & mask;
 534                         line[x] = inverse_translate(vc, glyph, true);
 535                 }
 536         }
 537
 538         vc->vc_uni_screen = uniscr;
 539         return 0;
 540 }
 541
 542 /*
 543  * Called from vcs_read() to get the unicode data from the screen.
 544  * This must be preceded by a successful call to vc_uniscr_check() once
 545  * the console lock has been taken.
 546  */
 547 void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed,
 548                          unsigned int row, unsigned int col, unsigned int nr)
 549 {
 550         struct uni_screen *uniscr = get_vc_uniscr(vc);
 551         int offset = row * vc->vc_size_row + col * 2;
 552         unsigned long pos;
 553
 554         BUG_ON(!uniscr);
 555
 556         pos = (unsigned long)screenpos(vc, offset, viewed);
 557         if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
 558                 /*
 559                  * Desired position falls in the main screen buffer.
 560                  * However the actual row/col might be different if
 561                  * scrollback is active.
 562                  */
 563                 row = (pos - vc->vc_origin) / vc->vc_size_row;
 564                 col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
 565                 memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t));
 566         } else {
 567                 /*
 568                  * Scrollback is active. For now let's simply backtranslate
 569                  * the screen glyphs until the unicode screen buffer does
 570                  * synchronize with console display drivers for a scrollback
 571                  * buffer of its own.
 572                  */
 573                 u16 *p = (u16 *)pos;
 574                 int mask = vc->vc_hi_font_mask | 0xff;
 575                 char32_t *uni_buf = dest;
 576                 while (nr--) {
 577                         u16 glyph = scr_readw(p++) & mask;
 578                         *uni_buf++ = inverse_translate(vc, glyph, true);
 579                 }
 580         }
 581 }
 582
 583 /* this is for validation and debugging only */
 584 static void vc_uniscr_debug_check(struct vc_data *vc)
 585 {
 586         struct uni_screen *uniscr = get_vc_uniscr(vc);
 587         unsigned short *p;
 588         int x, y, mask;
 589
 590         if (!VC_UNI_SCREEN_DEBUG || !uniscr)
 591                 return;
 592
 593         WARN_CONSOLE_UNLOCKED();
 594
 595         /*
 596          * Make sure our unicode screen translates into the same glyphs
 597          * as the actual screen. This is brutal indeed.
 598          */
 599         p = (unsigned short *)vc->vc_origin;
 600         mask = vc->vc_hi_font_mask | 0xff;
 601         for (y = 0; y < vc->vc_rows; y++) {
 602                 char32_t *line = uniscr->lines[y];
 603                 for (x = 0; x < vc->vc_cols; x++) {
 604                         u16 glyph = scr_readw(p++) & mask;
 605                         char32_t uc = line[x];
 606                         int tc = conv_uni_to_pc(vc, uc);
 607                         if (tc == -4)
 608                                 tc = conv_uni_to_pc(vc, 0xfffd);
 609                         if (tc == -4)
 610                                 tc = conv_uni_to_pc(vc, '?');
 611                         if (tc != glyph)
 612                                 pr_err_ratelimited(
 613                                         "%s: mismatch at %d,%d: glyph=%#x tc=%#x\n",
 614                                         __func__, x, y, glyph, tc);
 615                 }
 616         }
 617 }
 618
 619
 620 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 621                 enum con_scroll dir, unsigned int nr)
 622 {
 623         u16 *clear, *d, *s;
 624
 625         if (t + nr >= b)
 626                 nr = b - t - 1;
 627         if (b > vc->vc_rows || t >= b || nr < 1)
 628                 return;
 629         vc_uniscr_scroll(vc, t, b, dir, nr);
 630         if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
 631                 return;
 632
 633         s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
 634         d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
 635
 636         if (dir == SM_UP) {
 637                 clear = s + (b - t - nr) * vc->vc_cols;
 638                 swap(s, d);
 639         }
 640         scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
 641         scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
 642 }
 643
 644 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 645 {
 646         unsigned int xx, yy, offset;
 647         u16 *p;
 648
 649         p = (u16 *) start;
 650         if (!vc->vc_sw->con_getxy) {
 651                 offset = (start - vc->vc_origin) / 2;
 652                 xx = offset % vc->vc_cols;
 653                 yy = offset / vc->vc_cols;
 654         } else {
 655                 int nxx, nyy;
 656                 start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
 657                 xx = nxx; yy = nyy;
 658         }
 659         for(;;) {
 660                 u16 attrib = scr_readw(p) & 0xff00;
 661                 int startx = xx;
 662                 u16 *q = p;
 663                 while (xx < vc->vc_cols && count) {
 664                         if (attrib != (scr_readw(p) & 0xff00)) {
 665                                 if (p > q)
 666                                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 667                                 startx = xx;
 668                                 q = p;
 669                                 attrib = scr_readw(p) & 0xff00;
 670                         }
 671                         p++;
 672                         xx++;
 673                         count--;
 674                 }
 675                 if (p > q)
 676                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 677                 if (!count)
 678                         break;
 679                 xx = 0;
 680                 yy++;
 681                 if (vc->vc_sw->con_getxy) {
 682                         p = (u16 *)start;
 683                         start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
 684                 }
 685         }
 686 }
 687
 688 void update_region(struct vc_data *vc, unsigned long start, int count)
 689 {
 690         WARN_CONSOLE_UNLOCKED();
 691
 692         if (con_should_update(vc)) {
 693                 hide_cursor(vc);
 694                 do_update_region(vc, start, count);
 695                 set_cursor(vc);
 696         }
 697 }
 698
 699 /* Structure of attributes is hardware-dependent */
 700
 701 static u8 build_attr(struct vc_data *vc, u8 _color,
 702                 enum vc_intensity _intensity, bool _blink, bool _underline,
 703                 bool _reverse, bool _italic)
 704 {
 705         if (vc->vc_sw->con_build_attr)
 706                 return vc->vc_sw->con_build_attr(vc, _color, _intensity,
 707                        _blink, _underline, _reverse, _italic);
 708
 709 /*
 710  * ++roman: I completely changed the attribute format for monochrome
 711  * mode (!can_do_color). The formerly used MDA (monochrome display
 712  * adapter) format didn't allow the combination of certain effects.
 713  * Now the attribute is just a bit vector:
 714  *  Bit 0..1: intensity (0..2)
 715  *  Bit 2   : underline
 716  *  Bit 3   : reverse
 717  *  Bit 7   : blink
 718  */
 719         {
 720         u8 a = _color;
 721         if (!vc->vc_can_do_color)
 722                 return _intensity |
 723                        (_italic    << 1) |
 724                        (_underline << 2) |
 725                        (_reverse   << 3) |
 726                        (_blink     << 7);
 727         if (_italic)
 728                 a = (a & 0xF0) | vc->vc_itcolor;
 729         else if (_underline)
 730                 a = (a & 0xf0) | vc->vc_ulcolor;
 731         else if (_intensity == VCI_HALF_BRIGHT)
 732                 a = (a & 0xf0) | vc->vc_halfcolor;
 733         if (_reverse)
 734                 a = (a & 0x88) | (((a >> 4) | (a << 4)) & 0x77);
 735         if (_blink)
 736                 a ^= 0x80;
 737         if (_intensity == VCI_BOLD)
 738                 a ^= 0x08;
 739         if (vc->vc_hi_font_mask == 0x100)
 740                 a <<= 1;
 741         return a;
 742         }
 743 }
 744
 745 static void update_attr(struct vc_data *vc)
 746 {
 747         vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
 748                       vc->state.blink, vc->state.underline,
 749                       vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
 750         vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
 751                                 VCI_NORMAL, vc->state.blink, false,
 752                                 vc->vc_decscnm, false) << 8);
 753 }
 754
 755 /* Note: inverting the screen twice should revert to the original state */
 756 void invert_screen(struct vc_data *vc, int offset, int count, bool viewed)
 757 {
 758         unsigned short *p;
 759
 760         WARN_CONSOLE_UNLOCKED();
 761
 762         count /= 2;
 763         p = screenpos(vc, offset, viewed);
 764         if (vc->vc_sw->con_invert_region) {
 765                 vc->vc_sw->con_invert_region(vc, p, count);
 766         } else {
 767                 u16 *q = p;
 768                 int cnt = count;
 769                 u16 a;
 770
 771                 if (!vc->vc_can_do_color) {
 772                         while (cnt--) {
 773                             a = scr_readw(q);
 774                             a ^= 0x0800;
 775                             scr_writew(a, q);
 776                             q++;
 777                         }
 778                 } else if (vc->vc_hi_font_mask == 0x100) {
 779                         while (cnt--) {
 780                                 a = scr_readw(q);
 781                                 a = (a & 0x11ff) |
 782                                    ((a & 0xe000) >> 4) |
 783                                    ((a & 0x0e00) << 4);
 784                                 scr_writew(a, q);
 785                                 q++;
 786                         }
 787                 } else {
 788                         while (cnt--) {
 789                                 a = scr_readw(q);
 790                                 a = (a & 0x88ff) |
 791                                    ((a & 0x7000) >> 4) |
 792                                    ((a & 0x0700) << 4);
 793                                 scr_writew(a, q);
 794                                 q++;
 795                         }
 796                 }
 797         }
 798
 799         if (con_should_update(vc))
 800                 do_update_region(vc, (unsigned long) p, count);
 801         notify_update(vc);
 802 }
 803
 804 /* used by selection: complement pointer position */
 805 void complement_pos(struct vc_data *vc, int offset)
 806 {
 807         static int old_offset = -1;
 808         static unsigned short old;
 809         static unsigned short oldx, oldy;
 810
 811         WARN_CONSOLE_UNLOCKED();
 812
 813         if (old_offset != -1 && old_offset >= 0 &&
 814             old_offset < vc->vc_screenbuf_size) {
 815                 scr_writew(old, screenpos(vc, old_offset, true));
 816                 if (con_should_update(vc))
 817                         vc->vc_sw->con_putc(vc, old, oldy, oldx);
 818                 notify_update(vc);
 819         }
 820
 821         old_offset = offset;
 822
 823         if (offset != -1 && offset >= 0 &&
 824             offset < vc->vc_screenbuf_size) {
 825                 unsigned short new;
 826                 unsigned short *p;
 827                 p = screenpos(vc, offset, true);
 828                 old = scr_readw(p);
 829                 new = old ^ vc->vc_complement_mask;
 830                 scr_writew(new, p);
 831                 if (con_should_update(vc)) {
 832                         oldx = (offset >> 1) % vc->vc_cols;
 833                         oldy = (offset >> 1) / vc->vc_cols;
 834                         vc->vc_sw->con_putc(vc, new, oldy, oldx);
 835                 }
 836                 notify_update(vc);
 837         }
 838 }
 839
 840 static void insert_char(struct vc_data *vc, unsigned int nr)
 841 {
 842         unsigned short *p = (unsigned short *) vc->vc_pos;
 843
 844         vc_uniscr_insert(vc, nr);
 845         scr_memmovew(p + nr, p, (vc->vc_cols - vc->state.x - nr) * 2);
 846         scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
 847         vc->vc_need_wrap = 0;
 848         if (con_should_update(vc))
 849                 do_update_region(vc, (unsigned long) p,
 850                         vc->vc_cols - vc->state.x);
 851 }
 852
 853 static void delete_char(struct vc_data *vc, unsigned int nr)
 854 {
 855         unsigned short *p = (unsigned short *) vc->vc_pos;
 856
 857         vc_uniscr_delete(vc, nr);
 858         scr_memcpyw(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
 859         scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
 860                         nr * 2);
 861         vc->vc_need_wrap = 0;
 862         if (con_should_update(vc))
 863                 do_update_region(vc, (unsigned long) p,
 864                         vc->vc_cols - vc->state.x);
 865 }
 866
 867 static int softcursor_original = -1;
 868
 869 static void add_softcursor(struct vc_data *vc)
 870 {
 871         int i = scr_readw((u16 *) vc->vc_pos);
 872         u32 type = vc->vc_cursor_type;
 873
 874         if (!(type & CUR_SW))
 875                 return;
 876         if (softcursor_original != -1)
 877                 return;
 878         softcursor_original = i;
 879         i |= CUR_SET(type);
 880         i ^= CUR_CHANGE(type);
 881         if ((type & CUR_ALWAYS_BG) &&
 882                         (softcursor_original & CUR_BG) == (i & CUR_BG))
 883                 i ^= CUR_BG;
 884         if ((type & CUR_INVERT_FG_BG) && (i & CUR_FG) == ((i & CUR_BG) >> 4))
 885                 i ^= CUR_FG;
 886         scr_writew(i, (u16 *)vc->vc_pos);
 887         if (con_should_update(vc))
 888                 vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
 889 }
 890
 891 static void hide_softcursor(struct vc_data *vc)
 892 {
 893         if (softcursor_original != -1) {
 894                 scr_writew(softcursor_original, (u16 *)vc->vc_pos);
 895                 if (con_should_update(vc))
 896                         vc->vc_sw->con_putc(vc, softcursor_original,
 897                                         vc->state.y, vc->state.x);
 898                 softcursor_original = -1;
 899         }
 900 }
 901
 902 static void hide_cursor(struct vc_data *vc)
 903 {
 904         if (vc_is_sel(vc))
 905                 clear_selection();
 906
 907         vc->vc_sw->con_cursor(vc, CM_ERASE);
 908         hide_softcursor(vc);
 909 }
 910
 911 static void set_cursor(struct vc_data *vc)
 912 {
 913         if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
 914                 return;
 915         if (vc->vc_deccm) {
 916                 if (vc_is_sel(vc))
 917                         clear_selection();
 918                 add_softcursor(vc);
 919                 if (CUR_SIZE(vc->vc_cursor_type) != CUR_NONE)
 920                         vc->vc_sw->con_cursor(vc, CM_DRAW);
 921         } else
 922                 hide_cursor(vc);
 923 }
 924
 925 static void set_origin(struct vc_data *vc)
 926 {
 927         WARN_CONSOLE_UNLOCKED();
 928
 929         if (!con_is_visible(vc) ||
 930             !vc->vc_sw->con_set_origin ||
 931             !vc->vc_sw->con_set_origin(vc))
 932                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
 933         vc->vc_visible_origin = vc->vc_origin;
 934         vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
 935         vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->state.y +
 936                 2 * vc->state.x;
 937 }
 938
 939 static void save_screen(struct vc_data *vc)
 940 {
 941         WARN_CONSOLE_UNLOCKED();
 942
 943         if (vc->vc_sw->con_save_screen)
 944                 vc->vc_sw->con_save_screen(vc);
 945 }
 946
 947 static void flush_scrollback(struct vc_data *vc)
 948 {
 949         WARN_CONSOLE_UNLOCKED();
 950
 951         set_origin(vc);
 952         if (vc->vc_sw->con_flush_scrollback) {
 953                 vc->vc_sw->con_flush_scrollback(vc);
 954         } else if (con_is_visible(vc)) {
 955                 /*
 956                  * When no con_flush_scrollback method is provided then the
 957                  * legacy way for flushing the scrollback buffer is to use
 958                  * a side effect of the con_switch method. We do it only on
 959                  * the foreground console as background consoles have no
 960                  * scrollback buffers in that case and we obviously don't
 961                  * want to switch to them.
 962                  */
 963                 hide_cursor(vc);
 964                 vc->vc_sw->con_switch(vc);
 965                 set_cursor(vc);
 966         }
 967 }
 968
 969 /*
 970  *      Redrawing of screen
 971  */
 972
 973 void clear_buffer_attributes(struct vc_data *vc)
 974 {
 975         unsigned short *p = (unsigned short *)vc->vc_origin;
 976         int count = vc->vc_screenbuf_size / 2;
 977         int mask = vc->vc_hi_font_mask | 0xff;
 978
 979         for (; count > 0; count--, p++) {
 980                 scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
 981         }
 982 }
 983
 984 void redraw_screen(struct vc_data *vc, int is_switch)
 985 {
 986         int redraw = 0;
 987
 988         WARN_CONSOLE_UNLOCKED();
 989
 990         if (!vc) {
 991                 /* strange ... */
 992                 /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
 993                 return;
 994         }
 995
 996         if (is_switch) {
 997                 struct vc_data *old_vc = vc_cons[fg_console].d;
 998                 if (old_vc == vc)
 999                         return;
1000                 if (!con_is_visible(vc))
1001                         redraw = 1;
1002                 *vc->vc_display_fg = vc;
1003                 fg_console = vc->vc_num;
1004                 hide_cursor(old_vc);
1005                 if (!con_is_visible(old_vc)) {
1006                         save_screen(old_vc);
1007                         set_origin(old_vc);
1008                 }
1009                 if (tty0dev)
1010                         sysfs_notify(&tty0dev->kobj, NULL, "active");
1011         } else {
1012                 hide_cursor(vc);
1013                 redraw = 1;
1014         }
1015
1016         if (redraw) {
1017                 int update;
1018                 int old_was_color = vc->vc_can_do_color;
1019
1020                 set_origin(vc);
1021                 update = vc->vc_sw->con_switch(vc);
1022                 set_palette(vc);
1023                 /*
1024                  * If console changed from mono<->color, the best we can do
1025                  * is to clear the buffer attributes. As it currently stands,
1026                  * rebuilding new attributes from the old buffer is not doable
1027                  * without overly complex code.
1028                  */
1029                 if (old_was_color != vc->vc_can_do_color) {
1030                         update_attr(vc);
1031                         clear_buffer_attributes(vc);
1032                 }
1033
1034                 if (update && vc->vc_mode != KD_GRAPHICS)
1035                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1036         }
1037         set_cursor(vc);
1038         if (is_switch) {
1039                 vt_set_leds_compute_shiftstate();
1040                 notify_update(vc);
1041         }
1042 }
1043
1044 /*
1045  *      Allocation, freeing and resizing of VTs.
1046  */
1047
1048 int vc_cons_allocated(unsigned int i)
1049 {
1050         return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1051 }
1052
1053 static void visual_init(struct vc_data *vc, int num, int init)
1054 {
1055         /* ++Geert: vc->vc_sw->con_init determines console size */
1056         if (vc->vc_sw)
1057                 module_put(vc->vc_sw->owner);
1058         vc->vc_sw = conswitchp;
1059 #ifndef VT_SINGLE_DRIVER
1060         if (con_driver_map[num])
1061                 vc->vc_sw = con_driver_map[num];
1062 #endif
1063         __module_get(vc->vc_sw->owner);
1064         vc->vc_num = num;
1065         vc->vc_display_fg = &master_display_fg;
1066         if (vc->vc_uni_pagedir_loc)
1067                 con_free_unimap(vc);
1068         vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
1069         vc->vc_uni_pagedir = NULL;
1070         vc->vc_hi_font_mask = 0;
1071         vc->vc_complement_mask = 0;
1072         vc->vc_can_do_color = 0;
1073         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1074         vc->vc_sw->con_init(vc, init);
1075         if (!vc->vc_complement_mask)
1076                 vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1077         vc->vc_s_complement_mask = vc->vc_complement_mask;
1078         vc->vc_size_row = vc->vc_cols << 1;
1079         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1080 }
1081
1082
1083 static void visual_deinit(struct vc_data *vc)
1084 {
1085         vc->vc_sw->con_deinit(vc);
1086         module_put(vc->vc_sw->owner);
1087 }
1088
1089 static void vc_port_destruct(struct tty_port *port)
1090 {
1091         struct vc_data *vc = container_of(port, struct vc_data, port);
1092
1093         kfree(vc);
1094 }
1095
1096 static const struct tty_port_operations vc_port_ops = {
1097         .destruct = vc_port_destruct,
1098 };
1099
1100 /*
1101  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1102  * [this is to be used together with some user program
1103  * like resize that changes the hardware videomode]
1104  */
1105 #define VC_MAXCOL (32767)
1106 #define VC_MAXROW (32767)
1107
1108 int vc_allocate(unsigned int currcons)  /* return 0 on success */
1109 {
1110         struct vt_notifier_param param;
1111         struct vc_data *vc;
1112         int err;
1113
1114         WARN_CONSOLE_UNLOCKED();
1115
1116         if (currcons >= MAX_NR_CONSOLES)
1117                 return -ENXIO;
1118
1119         if (vc_cons[currcons].d)
1120                 return 0;
1121
1122         /* due to the granularity of kmalloc, we waste some memory here */
1123         /* the alloc is done in two steps, to optimize the common situation
1124            of a 25x80 console (structsize=216, screenbuf_size=4000) */
1125         /* although the numbers above are not valid since long ago, the
1126            point is still up-to-date and the comment still has its value
1127            even if only as a historical artifact.  --mj, July 1998 */
1128         param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1129         if (!vc)
1130                 return -ENOMEM;
1131
1132         vc_cons[currcons].d = vc;
1133         tty_port_init(&vc->port);
1134         vc->port.ops = &vc_port_ops;
1135         INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1136
1137         visual_init(vc, currcons, 1);
1138
1139         if (!*vc->vc_uni_pagedir_loc)
1140                 con_set_default_unimap(vc);
1141
1142         err = -EINVAL;
1143         if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
1144             vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
1145                 goto err_free;
1146         err = -ENOMEM;
1147         vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1148         if (!vc->vc_screenbuf)
1149                 goto err_free;
1150
1151         /* If no drivers have overridden us and the user didn't pass a
1152            boot option, default to displaying the cursor */
1153         if (global_cursor_default == -1)
1154                 global_cursor_default = 1;
1155
1156         vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
1157         vcs_make_sysfs(currcons);
1158         atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1159
1160         return 0;
1161 err_free:
1162         visual_deinit(vc);
1163         kfree(vc);
1164         vc_cons[currcons].d = NULL;
1165         return err;
1166 }
1167
1168 static inline int resize_screen(struct vc_data *vc, int width, int height,
1169                                 int user)
1170 {
1171         /* Resizes the resolution of the display adapater */
1172         int err = 0;
1173
1174         if (vc->vc_sw->con_resize)
1175                 err = vc->vc_sw->con_resize(vc, width, height, user);
1176
1177         return err;
1178 }
1179
1180 /**
1181  *      vc_do_resize    -       resizing method for the tty
1182  *      @tty: tty being resized
1183  *      @vc: virtual console private data
1184  *      @cols: columns
1185  *      @lines: lines
1186  *
1187  *      Resize a virtual console, clipping according to the actual constraints.
1188  *      If the caller passes a tty structure then update the termios winsize
1189  *      information and perform any necessary signal handling.
1190  *
1191  *      Caller must hold the console semaphore. Takes the termios rwsem and
1192  *      ctrl.lock of the tty IFF a tty is passed.
1193  */
1194
1195 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1196                                 unsigned int cols, unsigned int lines)
1197 {
1198         unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1199         unsigned long end;
1200         unsigned int old_rows, old_row_size, first_copied_row;
1201         unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1202         unsigned int user;
1203         unsigned short *oldscreen, *newscreen;
1204         struct uni_screen *new_uniscr = NULL;
1205
1206         WARN_CONSOLE_UNLOCKED();
1207
1208         if (!vc)
1209                 return -ENXIO;
1210
1211         user = vc->vc_resize_user;
1212         vc->vc_resize_user = 0;
1213
1214         if (cols > VC_MAXCOL || lines > VC_MAXROW)
1215                 return -EINVAL;
1216
1217         new_cols = (cols ? cols : vc->vc_cols);
1218         new_rows = (lines ? lines : vc->vc_rows);
1219         new_row_size = new_cols << 1;
1220         new_screen_size = new_row_size * new_rows;
1221
1222         if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
1223                 return 0;
1224
1225         if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
1226                 return -EINVAL;
1227         newscreen = kzalloc(new_screen_size, GFP_USER);
1228         if (!newscreen)
1229                 return -ENOMEM;
1230
1231         if (get_vc_uniscr(vc)) {
1232                 new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1233                 if (!new_uniscr) {
1234                         kfree(newscreen);
1235                         return -ENOMEM;
1236                 }
1237         }
1238
1239         if (vc_is_sel(vc))
1240                 clear_selection();
1241
1242         old_rows = vc->vc_rows;
1243         old_row_size = vc->vc_size_row;
1244
1245         err = resize_screen(vc, new_cols, new_rows, user);
1246         if (err) {
1247                 kfree(newscreen);
1248                 vc_uniscr_free(new_uniscr);
1249                 return err;
1250         }
1251
1252         vc->vc_rows = new_rows;
1253         vc->vc_cols = new_cols;
1254         vc->vc_size_row = new_row_size;
1255         vc->vc_screenbuf_size = new_screen_size;
1256
1257         rlth = min(old_row_size, new_row_size);
1258         rrem = new_row_size - rlth;
1259         old_origin = vc->vc_origin;
1260         new_origin = (long) newscreen;
1261         new_scr_end = new_origin + new_screen_size;
1262
1263         if (vc->state.y > new_rows) {
1264                 if (old_rows - vc->state.y < new_rows) {
1265                         /*
1266                          * Cursor near the bottom, copy contents from the
1267                          * bottom of buffer
1268                          */
1269                         first_copied_row = (old_rows - new_rows);
1270                 } else {
1271                         /*
1272                          * Cursor is in no man's land, copy 1/2 screenful
1273                          * from the top and bottom of cursor position
1274                          */
1275                         first_copied_row = (vc->state.y - new_rows/2);
1276                 }
1277                 old_origin += first_copied_row * old_row_size;
1278         } else
1279                 first_copied_row = 0;
1280         end = old_origin + old_row_size * min(old_rows, new_rows);
1281
1282         vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1283                             get_vc_uniscr(vc), rlth/2, first_copied_row,
1284                             min(old_rows, new_rows));
1285         vc_uniscr_set(vc, new_uniscr);
1286
1287         update_attr(vc);
1288
1289         while (old_origin < end) {
1290                 scr_memcpyw((unsigned short *) new_origin,
1291                             (unsigned short *) old_origin, rlth);
1292                 if (rrem)
1293                         scr_memsetw((void *)(new_origin + rlth),
1294                                     vc->vc_video_erase_char, rrem);
1295                 old_origin += old_row_size;
1296                 new_origin += new_row_size;
1297         }
1298         if (new_scr_end > new_origin)
1299                 scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1300                             new_scr_end - new_origin);
1301         oldscreen = vc->vc_screenbuf;
1302         vc->vc_screenbuf = newscreen;
1303         vc->vc_screenbuf_size = new_screen_size;
1304         set_origin(vc);
1305         kfree(oldscreen);
1306
1307         /* do part of a reset_terminal() */
1308         vc->vc_top = 0;
1309         vc->vc_bottom = vc->vc_rows;
1310         gotoxy(vc, vc->state.x, vc->state.y);
1311         save_cur(vc);
1312
1313         if (tty) {
1314                 /* Rewrite the requested winsize data with the actual
1315                    resulting sizes */
1316                 struct winsize ws;
1317                 memset(&ws, 0, sizeof(ws));
1318                 ws.ws_row = vc->vc_rows;
1319                 ws.ws_col = vc->vc_cols;
1320                 ws.ws_ypixel = vc->vc_scan_lines;
1321                 tty_do_resize(tty, &ws);
1322         }
1323
1324         if (con_is_visible(vc))
1325                 update_screen(vc);
1326         vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1327         notify_update(vc);
1328         return err;
1329 }
1330
1331 /**
1332  *      vc_resize               -       resize a VT
1333  *      @vc: virtual console
1334  *      @cols: columns
1335  *      @rows: rows
1336  *
1337  *      Resize a virtual console as seen from the console end of things. We
1338  *      use the common vc_do_resize methods to update the structures. The
1339  *      caller must hold the console sem to protect console internals and
1340  *      vc->port.tty
1341  */
1342
1343 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1344 {
1345         return vc_do_resize(vc->port.tty, vc, cols, rows);
1346 }
1347
1348 /**
1349  *      vt_resize               -       resize a VT
1350  *      @tty: tty to resize
1351  *      @ws: winsize attributes
1352  *
1353  *      Resize a virtual terminal. This is called by the tty layer as we
1354  *      register our own handler for resizing. The mutual helper does all
1355  *      the actual work.
1356  *
1357  *      Takes the console sem and the called methods then take the tty
1358  *      termios_rwsem and the tty ctrl.lock in that order.
1359  */
1360 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1361 {
1362         struct vc_data *vc = tty->driver_data;
1363         int ret;
1364
1365         console_lock();
1366         ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1367         console_unlock();
1368         return ret;
1369 }
1370
1371 struct vc_data *vc_deallocate(unsigned int currcons)
1372 {
1373         struct vc_data *vc = NULL;
1374
1375         WARN_CONSOLE_UNLOCKED();
1376
1377         if (vc_cons_allocated(currcons)) {
1378                 struct vt_notifier_param param;
1379
1380                 param.vc = vc = vc_cons[currcons].d;
1381                 atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1382                 vcs_remove_sysfs(currcons);
1383                 visual_deinit(vc);
1384                 con_free_unimap(vc);
1385                 put_pid(vc->vt_pid);
1386                 vc_uniscr_set(vc, NULL);
1387                 kfree(vc->vc_screenbuf);
1388                 vc_cons[currcons].d = NULL;
1389         }
1390         return vc;
1391 }
1392
1393 /*
1394  *      VT102 emulator
1395  */
1396
1397 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1398
1399 #define set_kbd(vc, x)  vt_set_kbd_mode_bit((vc)->vc_num, (x))
1400 #define clr_kbd(vc, x)  vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1401 #define is_kbd(vc, x)   vt_get_kbd_mode_bit((vc)->vc_num, (x))
1402
1403 #define decarm          VC_REPEAT
1404 #define decckm          VC_CKMODE
1405 #define kbdapplic       VC_APPLIC
1406 #define lnm             VC_CRLF
1407
1408 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1409                                        8,12,10,14, 9,13,11,15 };
1410
1411 /* the default colour table, for VGA+ colour systems */
1412 unsigned char default_red[] = {
1413         0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1414         0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1415 };
1416 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1417
1418 unsigned char default_grn[] = {
1419         0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1420         0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1421 };
1422 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1423
1424 unsigned char default_blu[] = {
1425         0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1426         0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1427 };
1428 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1429
1430 /*
1431  * gotoxy() must verify all boundaries, because the arguments
1432  * might also be negative. If the given position is out of
1433  * bounds, the cursor is placed at the nearest margin.
1434  */
1435 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1436 {
1437         int min_y, max_y;
1438
1439         if (new_x < 0)
1440                 vc->state.x = 0;
1441         else {
1442                 if (new_x >= vc->vc_cols)
1443                         vc->state.x = vc->vc_cols - 1;
1444                 else
1445                         vc->state.x = new_x;
1446         }
1447
1448         if (vc->vc_decom) {
1449                 min_y = vc->vc_top;
1450                 max_y = vc->vc_bottom;
1451         } else {
1452                 min_y = 0;
1453                 max_y = vc->vc_rows;
1454         }
1455         if (new_y < min_y)
1456                 vc->state.y = min_y;
1457         else if (new_y >= max_y)
1458                 vc->state.y = max_y - 1;
1459         else
1460                 vc->state.y = new_y;
1461         vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
1462                 (vc->state.x << 1);
1463         vc->vc_need_wrap = 0;
1464 }
1465
1466 /* for absolute user moves, when decom is set */
1467 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1468 {
1469         gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1470 }
1471
1472 void scrollback(struct vc_data *vc)
1473 {
1474         scrolldelta(-(vc->vc_rows / 2));
1475 }
1476
1477 void scrollfront(struct vc_data *vc, int lines)
1478 {
1479         if (!lines)
1480                 lines = vc->vc_rows / 2;
1481         scrolldelta(lines);
1482 }
1483
1484 static void lf(struct vc_data *vc)
1485 {
1486         /* don't scroll if above bottom of scrolling region, or
1487          * if below scrolling region
1488          */
1489         if (vc->state.y + 1 == vc->vc_bottom)
1490                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1491         else if (vc->state.y < vc->vc_rows - 1) {
1492                 vc->state.y++;
1493                 vc->vc_pos += vc->vc_size_row;
1494         }
1495         vc->vc_need_wrap = 0;
1496         notify_write(vc, '\n');
1497 }
1498
1499 static void ri(struct vc_data *vc)
1500 {
1501         /* don't scroll if below top of scrolling region, or
1502          * if above scrolling region
1503          */
1504         if (vc->state.y == vc->vc_top)
1505                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1506         else if (vc->state.y > 0) {
1507                 vc->state.y--;
1508                 vc->vc_pos -= vc->vc_size_row;
1509         }
1510         vc->vc_need_wrap = 0;
1511 }
1512
1513 static inline void cr(struct vc_data *vc)
1514 {
1515         vc->vc_pos -= vc->state.x << 1;
1516         vc->vc_need_wrap = vc->state.x = 0;
1517         notify_write(vc, '\r');
1518 }
1519
1520 static inline void bs(struct vc_data *vc)
1521 {
1522         if (vc->state.x) {
1523                 vc->vc_pos -= 2;
1524                 vc->state.x--;
1525                 vc->vc_need_wrap = 0;
1526                 notify_write(vc, '\b');
1527         }
1528 }
1529
1530 static inline void del(struct vc_data *vc)
1531 {
1532         /* ignored */
1533 }
1534
1535 static void csi_J(struct vc_data *vc, int vpar)
1536 {
1537         unsigned int count;
1538         unsigned short * start;
1539
1540         switch (vpar) {
1541                 case 0: /* erase from cursor to end of display */
1542                         vc_uniscr_clear_line(vc, vc->state.x,
1543                                              vc->vc_cols - vc->state.x);
1544                         vc_uniscr_clear_lines(vc, vc->state.y + 1,
1545                                               vc->vc_rows - vc->state.y - 1);
1546                         count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1547                         start = (unsigned short *)vc->vc_pos;
1548                         break;
1549                 case 1: /* erase from start to cursor */
1550                         vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
1551                         vc_uniscr_clear_lines(vc, 0, vc->state.y);
1552                         count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1553                         start = (unsigned short *)vc->vc_origin;
1554                         break;
1555                 case 3: /* include scrollback */
1556                         flush_scrollback(vc);
1557                         fallthrough;
1558                 case 2: /* erase whole display */
1559                         vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1560                         count = vc->vc_cols * vc->vc_rows;
1561                         start = (unsigned short *)vc->vc_origin;
1562                         break;
1563                 default:
1564                         return;
1565         }
1566         scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1567         if (con_should_update(vc))
1568                 do_update_region(vc, (unsigned long) start, count);
1569         vc->vc_need_wrap = 0;
1570 }
1571
1572 static void csi_K(struct vc_data *vc, int vpar)
1573 {
1574         unsigned int count;
1575         unsigned short *start = (unsigned short *)vc->vc_pos;
1576         int offset;
1577
1578         switch (vpar) {
1579                 case 0: /* erase from cursor to end of line */
1580                         offset = 0;
1581                         count = vc->vc_cols - vc->state.x;
1582                         break;
1583                 case 1: /* erase from start of line to cursor */
1584                         offset = -vc->state.x;
1585                         count = vc->state.x + 1;
1586                         break;
1587                 case 2: /* erase whole line */
1588                         offset = -vc->state.x;
1589                         count = vc->vc_cols;
1590                         break;
1591                 default:
1592                         return;
1593         }
1594         vc_uniscr_clear_line(vc, vc->state.x + offset, count);
1595         scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1596         vc->vc_need_wrap = 0;
1597         if (con_should_update(vc))
1598                 do_update_region(vc, (unsigned long)(start + offset), count);
1599 }
1600
1601 /* erase the following vpar positions */
1602 static void csi_X(struct vc_data *vc, unsigned int vpar)
1603 {                                         /* not vt100? */
1604         unsigned int count;
1605
1606         if (!vpar)
1607                 vpar++;
1608
1609         count = min(vpar, vc->vc_cols - vc->state.x);
1610
1611         vc_uniscr_clear_line(vc, vc->state.x, count);
1612         scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1613         if (con_should_update(vc))
1614                 vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
1615         vc->vc_need_wrap = 0;
1616 }
1617
1618 static void default_attr(struct vc_data *vc)
1619 {
1620         vc->state.intensity = VCI_NORMAL;
1621         vc->state.italic = false;
1622         vc->state.underline = false;
1623         vc->state.reverse = false;
1624         vc->state.blink = false;
1625         vc->state.color = vc->vc_def_color;
1626 }
1627
1628 struct rgb { u8 r; u8 g; u8 b; };
1629
1630 static void rgb_from_256(int i, struct rgb *c)
1631 {
1632         if (i < 8) {            /* Standard colours. */
1633                 c->r = i&1 ? 0xaa : 0x00;
1634                 c->g = i&2 ? 0xaa : 0x00;
1635                 c->b = i&4 ? 0xaa : 0x00;
1636         } else if (i < 16) {
1637                 c->r = i&1 ? 0xff : 0x55;
1638                 c->g = i&2 ? 0xff : 0x55;
1639                 c->b = i&4 ? 0xff : 0x55;
1640         } else if (i < 232) {   /* 6x6x6 colour cube. */
1641                 c->r = (i - 16) / 36 * 85 / 2;
1642                 c->g = (i - 16) / 6 % 6 * 85 / 2;
1643                 c->b = (i - 16) % 6 * 85 / 2;
1644         } else                  /* Grayscale ramp. */
1645                 c->r = c->g = c->b = i * 10 - 2312;
1646 }
1647
1648 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1649 {
1650         u8 hue = 0, max = max3(c->r, c->g, c->b);
1651
1652         if (c->r > max / 2)
1653                 hue |= 4;
1654         if (c->g > max / 2)
1655                 hue |= 2;
1656         if (c->b > max / 2)
1657                 hue |= 1;
1658
1659         if (hue == 7 && max <= 0x55) {
1660                 hue = 0;
1661                 vc->state.intensity = VCI_BOLD;
1662         } else if (max > 0xaa)
1663                 vc->state.intensity = VCI_BOLD;
1664         else
1665                 vc->state.intensity = VCI_NORMAL;
1666
1667         vc->state.color = (vc->state.color & 0xf0) | hue;
1668 }
1669
1670 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1671 {
1672         /* For backgrounds, err on the dark side. */
1673         vc->state.color = (vc->state.color & 0x0f)
1674                 | (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1675 }
1676
1677 /*
1678  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1679  * and thus need to be detected and ignored by hand. That standard also
1680  * wants : rather than ; as separators but sequences containing : are currently
1681  * completely ignored by the parser.
1682  *
1683  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1684  * supporting them.
1685  */
1686 static int vc_t416_color(struct vc_data *vc, int i,
1687                 void(*set_color)(struct vc_data *vc, const struct rgb *c))
1688 {
1689         struct rgb c;
1690
1691         i++;
1692         if (i > vc->vc_npar)
1693                 return i;
1694
1695         if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1696                 /* 256 colours */
1697                 i++;
1698                 rgb_from_256(vc->vc_par[i], &c);
1699         } else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1700                 /* 24 bit */
1701                 c.r = vc->vc_par[i + 1];
1702                 c.g = vc->vc_par[i + 2];
1703                 c.b = vc->vc_par[i + 3];
1704                 i += 3;
1705         } else
1706                 return i;
1707
1708         set_color(vc, &c);
1709
1710         return i;
1711 }
1712
1713 /* console_lock is held */
1714 static void csi_m(struct vc_data *vc)
1715 {
1716         int i;
1717
1718         for (i = 0; i <= vc->vc_npar; i++)
1719                 switch (vc->vc_par[i]) {
1720                 case 0: /* all attributes off */
1721                         default_attr(vc);
1722                         break;
1723                 case 1:
1724                         vc->state.intensity = VCI_BOLD;
1725                         break;
1726                 case 2:
1727                         vc->state.intensity = VCI_HALF_BRIGHT;
1728                         break;
1729                 case 3:
1730                         vc->state.italic = true;
1731                         break;
1732                 case 21:
1733                         /*
1734                          * No console drivers support double underline, so
1735                          * convert it to a single underline.
1736                          */
1737                 case 4:
1738                         vc->state.underline = true;
1739                         break;
1740                 case 5:
1741                         vc->state.blink = true;
1742                         break;
1743                 case 7:
1744                         vc->state.reverse = true;
1745                         break;
1746                 case 10: /* ANSI X3.64-1979 (SCO-ish?)
1747                           * Select primary font, don't display control chars if
1748                           * defined, don't set bit 8 on output.
1749                           */
1750                         vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset], vc);
1751                         vc->vc_disp_ctrl = 0;
1752                         vc->vc_toggle_meta = 0;
1753                         break;
1754                 case 11: /* ANSI X3.64-1979 (SCO-ish?)
1755                           * Select first alternate font, lets chars < 32 be
1756                           * displayed as ROM chars.
1757                           */
1758                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1759                         vc->vc_disp_ctrl = 1;
1760                         vc->vc_toggle_meta = 0;
1761                         break;
1762                 case 12: /* ANSI X3.64-1979 (SCO-ish?)
1763                           * Select second alternate font, toggle high bit
1764                           * before displaying as ROM char.
1765                           */
1766                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1767                         vc->vc_disp_ctrl = 1;
1768                         vc->vc_toggle_meta = 1;
1769                         break;
1770                 case 22:
1771                         vc->state.intensity = VCI_NORMAL;
1772                         break;
1773                 case 23:
1774                         vc->state.italic = false;
1775                         break;
1776                 case 24:
1777                         vc->state.underline = false;
1778                         break;
1779                 case 25:
1780                         vc->state.blink = false;
1781                         break;
1782                 case 27:
1783                         vc->state.reverse = false;
1784                         break;
1785                 case 38:
1786                         i = vc_t416_color(vc, i, rgb_foreground);
1787                         break;
1788                 case 48:
1789                         i = vc_t416_color(vc, i, rgb_background);
1790                         break;
1791                 case 39:
1792                         vc->state.color = (vc->vc_def_color & 0x0f) |
1793                                 (vc->state.color & 0xf0);
1794                         break;
1795                 case 49:
1796                         vc->state.color = (vc->vc_def_color & 0xf0) |
1797                                 (vc->state.color & 0x0f);
1798                         break;
1799                 default:
1800                         if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1801                                 if (vc->vc_par[i] < 100)
1802                                         vc->state.intensity = VCI_BOLD;
1803                                 vc->vc_par[i] -= 60;
1804                         }
1805                         if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1806                                 vc->state.color = color_table[vc->vc_par[i] - 30]
1807                                         | (vc->state.color & 0xf0);
1808                         else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1809                                 vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
1810                                         | (vc->state.color & 0x0f);
1811                         break;
1812                 }
1813         update_attr(vc);
1814 }
1815
1816 static void respond_string(const char *p, size_t len, struct tty_port *port)
1817 {
1818         tty_insert_flip_string(port, p, len);
1819         tty_schedule_flip(port);
1820 }
1821
1822 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1823 {
1824         char buf[40];
1825         int len;
1826
1827         len = sprintf(buf, "\033[%d;%dR", vc->state.y +
1828                         (vc->vc_decom ? vc->vc_top + 1 : 1),
1829                         vc->state.x + 1);
1830         respond_string(buf, len, tty->port);
1831 }
1832
1833 static inline void status_report(struct tty_struct *tty)
1834 {
1835         static const char teminal_ok[] = "\033[0n";
1836
1837         respond_string(teminal_ok, strlen(teminal_ok), tty->port);
1838 }
1839
1840 static inline void respond_ID(struct tty_struct *tty)
1841 {
1842         /* terminal answer to an ESC-Z or csi0c query. */
1843         static const char vt102_id[] = "\033[?6c";
1844
1845         respond_string(vt102_id, strlen(vt102_id), tty->port);
1846 }
1847
1848 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1849 {
1850         char buf[8];
1851         int len;
1852
1853         len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
1854                         (char)('!' + mrx), (char)('!' + mry));
1855         respond_string(buf, len, tty->port);
1856 }
1857
1858 /* invoked via ioctl(TIOCLINUX) and through set_selection_user */
1859 int mouse_reporting(void)
1860 {
1861         return vc_cons[fg_console].d->vc_report_mouse;
1862 }
1863
1864 /* console_lock is held */
1865 static void set_mode(struct vc_data *vc, int on_off)
1866 {
1867         int i;
1868
1869         for (i = 0; i <= vc->vc_npar; i++)
1870                 if (vc->vc_priv == EPdec) {
1871                         switch(vc->vc_par[i]) { /* DEC private modes set/reset */
1872                         case 1:                 /* Cursor keys send ^[Ox/^[[x */
1873                                 if (on_off)
1874                                         set_kbd(vc, decckm);
1875                                 else
1876                                         clr_kbd(vc, decckm);
1877                                 break;
1878                         case 3: /* 80/132 mode switch unimplemented */
1879 #if 0
1880                                 vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1881                                 /* this alone does not suffice; some user mode
1882                                    utility has to change the hardware regs */
1883 #endif
1884                                 break;
1885                         case 5:                 /* Inverted screen on/off */
1886                                 if (vc->vc_decscnm != on_off) {
1887                                         vc->vc_decscnm = on_off;
1888                                         invert_screen(vc, 0,
1889                                                         vc->vc_screenbuf_size,
1890                                                         false);
1891                                         update_attr(vc);
1892                                 }
1893                                 break;
1894                         case 6:                 /* Origin relative/absolute */
1895                                 vc->vc_decom = on_off;
1896                                 gotoxay(vc, 0, 0);
1897                                 break;
1898                         case 7:                 /* Autowrap on/off */
1899                                 vc->vc_decawm = on_off;
1900                                 break;
1901                         case 8:                 /* Autorepeat on/off */
1902                                 if (on_off)
1903                                         set_kbd(vc, decarm);
1904                                 else
1905                                         clr_kbd(vc, decarm);
1906                                 break;
1907                         case 9:
1908                                 vc->vc_report_mouse = on_off ? 1 : 0;
1909                                 break;
1910                         case 25:                /* Cursor on/off */
1911                                 vc->vc_deccm = on_off;
1912                                 break;
1913                         case 1000:
1914                                 vc->vc_report_mouse = on_off ? 2 : 0;
1915                                 break;
1916                         }
1917                 } else {
1918                         switch(vc->vc_par[i]) { /* ANSI modes set/reset */
1919                         case 3:                 /* Monitor (display ctrls) */
1920                                 vc->vc_disp_ctrl = on_off;
1921                                 break;
1922                         case 4:                 /* Insert Mode on/off */
1923                                 vc->vc_decim = on_off;
1924                                 break;
1925                         case 20:                /* Lf, Enter == CrLf/Lf */
1926                                 if (on_off)
1927                                         set_kbd(vc, lnm);
1928                                 else
1929                                         clr_kbd(vc, lnm);
1930                                 break;
1931                         }
1932                 }
1933 }
1934
1935 /* console_lock is held */
1936 static void setterm_command(struct vc_data *vc)
1937 {
1938         switch (vc->vc_par[0]) {
1939         case 1: /* set color for underline mode */
1940                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1941                         vc->vc_ulcolor = color_table[vc->vc_par[1]];
1942                         if (vc->state.underline)
1943                                 update_attr(vc);
1944                 }
1945                 break;
1946         case 2: /* set color for half intensity mode */
1947                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1948                         vc->vc_halfcolor = color_table[vc->vc_par[1]];
1949                         if (vc->state.intensity == VCI_HALF_BRIGHT)
1950                                 update_attr(vc);
1951                 }
1952                 break;
1953         case 8: /* store colors as defaults */
1954                 vc->vc_def_color = vc->vc_attr;
1955                 if (vc->vc_hi_font_mask == 0x100)
1956                         vc->vc_def_color >>= 1;
1957                 default_attr(vc);
1958                 update_attr(vc);
1959                 break;
1960         case 9: /* set blanking interval */
1961                 blankinterval = min(vc->vc_par[1], 60U) * 60;
1962                 poke_blanked_console();
1963                 break;
1964         case 10: /* set bell frequency in Hz */
1965                 if (vc->vc_npar >= 1)
1966                         vc->vc_bell_pitch = vc->vc_par[1];
1967                 else
1968                         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1969                 break;
1970         case 11: /* set bell duration in msec */
1971                 if (vc->vc_npar >= 1)
1972                         vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1973                                 msecs_to_jiffies(vc->vc_par[1]) : 0;
1974                 else
1975                         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1976                 break;
1977         case 12: /* bring specified console to the front */
1978                 if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1979                         set_console(vc->vc_par[1] - 1);
1980                 break;
1981         case 13: /* unblank the screen */
1982                 poke_blanked_console();
1983                 break;
1984         case 14: /* set vesa powerdown interval */
1985                 vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
1986                 break;
1987         case 15: /* activate the previous console */
1988                 set_console(last_console);
1989                 break;
1990         case 16: /* set cursor blink duration in msec */
1991                 if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1992                                 vc->vc_par[1] <= USHRT_MAX)
1993                         vc->vc_cur_blink_ms = vc->vc_par[1];
1994                 else
1995                         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1996                 break;
1997         }
1998 }
1999
2000 /* console_lock is held */
2001 static void csi_at(struct vc_data *vc, unsigned int nr)
2002 {
2003         if (nr > vc->vc_cols - vc->state.x)
2004                 nr = vc->vc_cols - vc->state.x;
2005         else if (!nr)
2006                 nr = 1;
2007         insert_char(vc, nr);
2008 }
2009
2010 /* console_lock is held */
2011 static void csi_L(struct vc_data *vc, unsigned int nr)
2012 {
2013         if (nr > vc->vc_rows - vc->state.y)
2014                 nr = vc->vc_rows - vc->state.y;
2015         else if (!nr)
2016                 nr = 1;
2017         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
2018         vc->vc_need_wrap = 0;
2019 }
2020
2021 /* console_lock is held */
2022 static void csi_P(struct vc_data *vc, unsigned int nr)
2023 {
2024         if (nr > vc->vc_cols - vc->state.x)
2025                 nr = vc->vc_cols - vc->state.x;
2026         else if (!nr)
2027                 nr = 1;
2028         delete_char(vc, nr);
2029 }
2030
2031 /* console_lock is held */
2032 static void csi_M(struct vc_data *vc, unsigned int nr)
2033 {
2034         if (nr > vc->vc_rows - vc->state.y)
2035                 nr = vc->vc_rows - vc->state.y;
2036         else if (!nr)
2037                 nr=1;
2038         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
2039         vc->vc_need_wrap = 0;
2040 }
2041
2042 /* console_lock is held (except via vc_init->reset_terminal */
2043 static void save_cur(struct vc_data *vc)
2044 {
2045         memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
2046 }
2047
2048 /* console_lock is held */
2049 static void restore_cur(struct vc_data *vc)
2050 {
2051         memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
2052
2053         gotoxy(vc, vc->state.x, vc->state.y);
2054         vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
2055                         vc);
2056         update_attr(vc);
2057         vc->vc_need_wrap = 0;
2058 }
2059
2060 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2061         EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2062         ESpalette, ESosc, ESapc, ESpm, ESdcs };
2063
2064 /* console_lock is held (except via vc_init()) */
2065 static void reset_terminal(struct vc_data *vc, int do_clear)
2066 {
2067         unsigned int i;
2068
2069         vc->vc_top              = 0;
2070         vc->vc_bottom           = vc->vc_rows;
2071         vc->vc_state            = ESnormal;
2072         vc->vc_priv             = EPecma;
2073         vc->vc_translate        = set_translate(LAT1_MAP, vc);
2074         vc->state.Gx_charset[0] = LAT1_MAP;
2075         vc->state.Gx_charset[1] = GRAF_MAP;
2076         vc->state.charset       = 0;
2077         vc->vc_need_wrap        = 0;
2078         vc->vc_report_mouse     = 0;
2079         vc->vc_utf              = default_utf8;
2080         vc->vc_utf_count        = 0;
2081
2082         vc->vc_disp_ctrl        = 0;
2083         vc->vc_toggle_meta      = 0;
2084
2085         vc->vc_decscnm          = 0;
2086         vc->vc_decom            = 0;
2087         vc->vc_decawm           = 1;
2088         vc->vc_deccm            = global_cursor_default;
2089         vc->vc_decim            = 0;
2090
2091         vt_reset_keyboard(vc->vc_num);
2092
2093         vc->vc_cursor_type = cur_default;
2094         vc->vc_complement_mask = vc->vc_s_complement_mask;
2095
2096         default_attr(vc);
2097         update_attr(vc);
2098
2099         bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2100         for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
2101                 set_bit(i, vc->vc_tab_stop);
2102
2103         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2104         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2105         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2106
2107         gotoxy(vc, 0, 0);
2108         save_cur(vc);
2109         if (do_clear)
2110             csi_J(vc, 2);
2111 }
2112
2113 static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
2114 {
2115         unsigned char *charset = &vc->state.Gx_charset[which];
2116
2117         switch (c) {
2118         case '0':
2119                 *charset = GRAF_MAP;
2120                 break;
2121         case 'B':
2122                 *charset = LAT1_MAP;
2123                 break;
2124         case 'U':
2125                 *charset = IBMPC_MAP;
2126                 break;
2127         case 'K':
2128                 *charset = USER_MAP;
2129                 break;
2130         }
2131
2132         if (vc->state.charset == which)
2133                 vc->vc_translate = set_translate(*charset, vc);
2134 }
2135
2136 /* is this state an ANSI control string? */
2137 static bool ansi_control_string(unsigned int state)
2138 {
2139         if (state == ESosc || state == ESapc || state == ESpm || state == ESdcs)
2140                 return true;
2141         return false;
2142 }
2143
2144 /* console_lock is held */
2145 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2146 {
2147         /*
2148          *  Control characters can be used in the _middle_
2149          *  of an escape sequence, aside from ANSI control strings.
2150          */
2151         if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
2152                 return;
2153         switch (c) {
2154         case 0:
2155                 return;
2156         case 7:
2157                 if (ansi_control_string(vc->vc_state))
2158                         vc->vc_state = ESnormal;
2159                 else if (vc->vc_bell_duration)
2160                         kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2161                 return;
2162         case 8:
2163                 bs(vc);
2164                 return;
2165         case 9:
2166                 vc->vc_pos -= (vc->state.x << 1);
2167
2168                 vc->state.x = find_next_bit(vc->vc_tab_stop,
2169                                 min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2170                                 vc->state.x + 1);
2171                 if (vc->state.x >= VC_TABSTOPS_COUNT)
2172                         vc->state.x = vc->vc_cols - 1;
2173
2174                 vc->vc_pos += (vc->state.x << 1);
2175                 notify_write(vc, '\t');
2176                 return;
2177         case 10: case 11: case 12:
2178                 lf(vc);
2179                 if (!is_kbd(vc, lnm))
2180                         return;
2181                 fallthrough;
2182         case 13:
2183                 cr(vc);
2184                 return;
2185         case 14:
2186                 vc->state.charset = 1;
2187                 vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2188                 vc->vc_disp_ctrl = 1;
2189                 return;
2190         case 15:
2191                 vc->state.charset = 0;
2192                 vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2193                 vc->vc_disp_ctrl = 0;
2194                 return;
2195         case 24: case 26:
2196                 vc->vc_state = ESnormal;
2197                 return;
2198         case 27:
2199                 vc->vc_state = ESesc;
2200                 return;
2201         case 127:
2202                 del(vc);
2203                 return;
2204         case 128+27:
2205                 vc->vc_state = ESsquare;
2206                 return;
2207         }
2208         switch(vc->vc_state) {
2209         case ESesc:
2210                 vc->vc_state = ESnormal;
2211                 switch (c) {
2212                 case '[':
2213                         vc->vc_state = ESsquare;
2214                         return;
2215                 case ']':
2216                         vc->vc_state = ESnonstd;
2217                         return;
2218                 case '_':
2219                         vc->vc_state = ESapc;
2220                         return;
2221                 case '^':
2222                         vc->vc_state = ESpm;
2223                         return;
2224                 case '%':
2225                         vc->vc_state = ESpercent;
2226                         return;
2227                 case 'E':
2228                         cr(vc);
2229                         lf(vc);
2230                         return;
2231                 case 'M':
2232                         ri(vc);
2233                         return;
2234                 case 'D':
2235                         lf(vc);
2236                         return;
2237                 case 'H':
2238                         if (vc->state.x < VC_TABSTOPS_COUNT)
2239                                 set_bit(vc->state.x, vc->vc_tab_stop);
2240                         return;
2241                 case 'P':
2242                         vc->vc_state = ESdcs;
2243                         return;
2244                 case 'Z':
2245                         respond_ID(tty);
2246                         return;
2247                 case '7':
2248                         save_cur(vc);
2249                         return;
2250                 case '8':
2251                         restore_cur(vc);
2252                         return;
2253                 case '(':
2254                         vc->vc_state = ESsetG0;
2255                         return;
2256                 case ')':
2257                         vc->vc_state = ESsetG1;
2258                         return;
2259                 case '#':
2260                         vc->vc_state = EShash;
2261                         return;
2262                 case 'c':
2263                         reset_terminal(vc, 1);
2264                         return;
2265                 case '>':  /* Numeric keypad */
2266                         clr_kbd(vc, kbdapplic);
2267                         return;
2268                 case '=':  /* Appl. keypad */
2269                         set_kbd(vc, kbdapplic);
2270                         return;
2271                 }
2272                 return;
2273         case ESnonstd:
2274                 if (c=='P') {   /* palette escape sequence */
2275                         for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2276                                 vc->vc_par[vc->vc_npar] = 0;
2277                         vc->vc_npar = 0;
2278                         vc->vc_state = ESpalette;
2279                         return;
2280                 } else if (c=='R') {   /* reset palette */
2281                         reset_palette(vc);
2282                         vc->vc_state = ESnormal;
2283                 } else if (c>='0' && c<='9')
2284                         vc->vc_state = ESosc;
2285                 else
2286                         vc->vc_state = ESnormal;
2287                 return;
2288         case ESpalette:
2289                 if (isxdigit(c)) {
2290                         vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2291                         if (vc->vc_npar == 7) {
2292                                 int i = vc->vc_par[0] * 3, j = 1;
2293                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2294                                 vc->vc_palette[i++] += vc->vc_par[j++];
2295                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2296                                 vc->vc_palette[i++] += vc->vc_par[j++];
2297                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2298                                 vc->vc_palette[i] += vc->vc_par[j];
2299                                 set_palette(vc);
2300                                 vc->vc_state = ESnormal;
2301                         }
2302                 } else
2303                         vc->vc_state = ESnormal;
2304                 return;
2305         case ESsquare:
2306                 for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2307                         vc->vc_par[vc->vc_npar] = 0;
2308                 vc->vc_npar = 0;
2309                 vc->vc_state = ESgetpars;
2310                 if (c == '[') { /* Function key */
2311                         vc->vc_state=ESfunckey;
2312                         return;
2313                 }
2314                 switch (c) {
2315                 case '?':
2316                         vc->vc_priv = EPdec;
2317                         return;
2318                 case '>':
2319                         vc->vc_priv = EPgt;
2320                         return;
2321                 case '=':
2322                         vc->vc_priv = EPeq;
2323                         return;
2324                 case '<':
2325                         vc->vc_priv = EPlt;
2326                         return;
2327                 }
2328                 vc->vc_priv = EPecma;
2329                 fallthrough;
2330         case ESgetpars:
2331                 if (c == ';' && vc->vc_npar < NPAR - 1) {
2332                         vc->vc_npar++;
2333                         return;
2334                 } else if (c>='0' && c<='9') {
2335                         vc->vc_par[vc->vc_npar] *= 10;
2336                         vc->vc_par[vc->vc_npar] += c - '0';
2337                         return;
2338                 }
2339                 if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2340                         vc->vc_state = EScsiignore;
2341                         return;
2342                 }
2343                 vc->vc_state = ESnormal;
2344                 switch(c) {
2345                 case 'h':
2346                         if (vc->vc_priv <= EPdec)
2347                                 set_mode(vc, 1);
2348                         return;
2349                 case 'l':
2350                         if (vc->vc_priv <= EPdec)
2351                                 set_mode(vc, 0);
2352                         return;
2353                 case 'c':
2354                         if (vc->vc_priv == EPdec) {
2355                                 if (vc->vc_par[0])
2356                                         vc->vc_cursor_type =
2357                                                 CUR_MAKE(vc->vc_par[0],
2358                                                          vc->vc_par[1],
2359                                                          vc->vc_par[2]);
2360                                 else
2361                                         vc->vc_cursor_type = cur_default;
2362                                 return;
2363                         }
2364                         break;
2365                 case 'm':
2366                         if (vc->vc_priv == EPdec) {
2367                                 clear_selection();
2368                                 if (vc->vc_par[0])
2369                                         vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2370                                 else
2371                                         vc->vc_complement_mask = vc->vc_s_complement_mask;
2372                                 return;
2373                         }
2374                         break;
2375                 case 'n':
2376                         if (vc->vc_priv == EPecma) {
2377                                 if (vc->vc_par[0] == 5)
2378                                         status_report(tty);
2379                                 else if (vc->vc_par[0] == 6)
2380                                         cursor_report(vc, tty);
2381                         }
2382                         return;
2383                 }
2384                 if (vc->vc_priv != EPecma) {
2385                         vc->vc_priv = EPecma;
2386                         return;
2387                 }
2388                 switch(c) {
2389                 case 'G': case '`':
2390                         if (vc->vc_par[0])
2391                                 vc->vc_par[0]--;
2392                         gotoxy(vc, vc->vc_par[0], vc->state.y);
2393                         return;
2394                 case 'A':
2395                         if (!vc->vc_par[0])
2396                                 vc->vc_par[0]++;
2397                         gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2398                         return;
2399                 case 'B': case 'e':
2400                         if (!vc->vc_par[0])
2401                                 vc->vc_par[0]++;
2402                         gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2403                         return;
2404                 case 'C': case 'a':
2405                         if (!vc->vc_par[0])
2406                                 vc->vc_par[0]++;
2407                         gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2408                         return;
2409                 case 'D':
2410                         if (!vc->vc_par[0])
2411                                 vc->vc_par[0]++;
2412                         gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2413                         return;
2414                 case 'E':
2415                         if (!vc->vc_par[0])
2416                                 vc->vc_par[0]++;
2417                         gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2418                         return;
2419                 case 'F':
2420                         if (!vc->vc_par[0])
2421                                 vc->vc_par[0]++;
2422                         gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2423                         return;
2424                 case 'd':
2425                         if (vc->vc_par[0])
2426                                 vc->vc_par[0]--;
2427                         gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2428                         return;
2429                 case 'H': case 'f':
2430                         if (vc->vc_par[0])
2431                                 vc->vc_par[0]--;
2432                         if (vc->vc_par[1])
2433                                 vc->vc_par[1]--;
2434                         gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2435                         return;
2436                 case 'J':
2437                         csi_J(vc, vc->vc_par[0]);
2438                         return;
2439                 case 'K':
2440                         csi_K(vc, vc->vc_par[0]);
2441                         return;
2442                 case 'L':
2443                         csi_L(vc, vc->vc_par[0]);
2444                         return;
2445                 case 'M':
2446                         csi_M(vc, vc->vc_par[0]);
2447                         return;
2448                 case 'P':
2449                         csi_P(vc, vc->vc_par[0]);
2450                         return;
2451                 case 'c':
2452                         if (!vc->vc_par[0])
2453                                 respond_ID(tty);
2454                         return;
2455                 case 'g':
2456                         if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2457                                 set_bit(vc->state.x, vc->vc_tab_stop);
2458                         else if (vc->vc_par[0] == 3)
2459                                 bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2460                         return;
2461                 case 'm':
2462                         csi_m(vc);
2463                         return;
2464                 case 'q': /* DECLL - but only 3 leds */
2465                         /* map 0,1,2,3 to 0,1,2,4 */
2466                         if (vc->vc_par[0] < 4)
2467                                 vt_set_led_state(vc->vc_num,
2468                                             (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2469                         return;
2470                 case 'r':
2471                         if (!vc->vc_par[0])
2472                                 vc->vc_par[0]++;
2473                         if (!vc->vc_par[1])
2474                                 vc->vc_par[1] = vc->vc_rows;
2475                         /* Minimum allowed region is 2 lines */
2476                         if (vc->vc_par[0] < vc->vc_par[1] &&
2477                             vc->vc_par[1] <= vc->vc_rows) {
2478                                 vc->vc_top = vc->vc_par[0] - 1;
2479                                 vc->vc_bottom = vc->vc_par[1];
2480                                 gotoxay(vc, 0, 0);
2481                         }
2482                         return;
2483                 case 's':
2484                         save_cur(vc);
2485                         return;
2486                 case 'u':
2487                         restore_cur(vc);
2488                         return;
2489                 case 'X':
2490                         csi_X(vc, vc->vc_par[0]);
2491                         return;
2492                 case '@':
2493                         csi_at(vc, vc->vc_par[0]);
2494                         return;
2495                 case ']': /* setterm functions */
2496                         setterm_command(vc);
2497                         return;
2498                 }
2499                 return;
2500         case EScsiignore:
2501                 if (c >= 20 && c <= 0x3f)
2502                         return;
2503                 vc->vc_state = ESnormal;
2504                 return;
2505         case ESpercent:
2506                 vc->vc_state = ESnormal;
2507                 switch (c) {
2508                 case '@':  /* defined in ISO 2022 */
2509                         vc->vc_utf = 0;
2510                         return;
2511                 case 'G':  /* prelim official escape code */
2512                 case '8':  /* retained for compatibility */
2513                         vc->vc_utf = 1;
2514                         return;
2515                 }
2516                 return;
2517         case ESfunckey:
2518                 vc->vc_state = ESnormal;
2519                 return;
2520         case EShash:
2521                 vc->vc_state = ESnormal;
2522                 if (c == '8') {
2523                         /* DEC screen alignment test. kludge :-) */
2524                         vc->vc_video_erase_char =
2525                                 (vc->vc_video_erase_char & 0xff00) | 'E';
2526                         csi_J(vc, 2);
2527                         vc->vc_video_erase_char =
2528                                 (vc->vc_video_erase_char & 0xff00) | ' ';
2529                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2530                 }
2531                 return;
2532         case ESsetG0:
2533                 vc_setGx(vc, 0, c);
2534                 vc->vc_state = ESnormal;
2535                 return;
2536         case ESsetG1:
2537                 vc_setGx(vc, 1, c);
2538                 vc->vc_state = ESnormal;
2539                 return;
2540         case ESapc:
2541                 return;
2542         case ESosc:
2543                 return;
2544         case ESpm:
2545                 return;
2546         case ESdcs:
2547                 return;
2548         default:
2549                 vc->vc_state = ESnormal;
2550         }
2551 }
2552
2553 /* is_double_width() is based on the wcwidth() implementation by
2554  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2555  * Latest version: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2556  */
2557 struct interval {
2558         uint32_t first;
2559         uint32_t last;
2560 };
2561
2562 static int ucs_cmp(const void *key, const void *elt)
2563 {
2564         uint32_t ucs = *(uint32_t *)key;
2565         struct interval e = *(struct interval *) elt;
2566
2567         if (ucs > e.last)
2568                 return 1;
2569         else if (ucs < e.first)
2570                 return -1;
2571         return 0;
2572 }
2573
2574 static int is_double_width(uint32_t ucs)
2575 {
2576         static const struct interval double_width[] = {
2577                 { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2578                 { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2579                 { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2580                 { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2581         };
2582         if (ucs < double_width[0].first ||
2583             ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2584                 return 0;
2585
2586         return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2587                         sizeof(struct interval), ucs_cmp) != NULL;
2588 }
2589
2590 struct vc_draw_region {
2591         unsigned long from, to;
2592         int x;
2593 };
2594
2595 static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
2596 {
2597         if (draw->x < 0)
2598                 return;
2599
2600         vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
2601                         (u16 *)draw->to - (u16 *)draw->from, vc->state.y,
2602                         draw->x);
2603         draw->x = -1;
2604 }
2605
2606 static inline int vc_translate_ascii(const struct vc_data *vc, int c)
2607 {
2608         if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
2609                 if (vc->vc_toggle_meta)
2610                         c |= 0x80;
2611
2612                 return vc->vc_translate[c];
2613         }
2614
2615         return c;
2616 }
2617
2618
2619 /**
2620  * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
2621  * @c: the received character, or U+FFFD for invalid sequences.
2622  */
2623 static inline int vc_sanitize_unicode(const int c)
2624 {
2625         if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2626                 return 0xfffd;
2627
2628         return c;
2629 }
2630
2631 /**
2632  * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
2633  * @vc: virtual console
2634  * @c: character to translate
2635  * @rescan: we return true if we need more (continuation) data
2636  *
2637  * @vc_utf_char is the being-constructed unicode character.
2638  * @vc_utf_count is the number of continuation bytes still expected to arrive.
2639  * @vc_npar is the number of continuation bytes arrived so far.
2640  */
2641 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
2642 {
2643         static const u32 utf8_length_changes[] = {
2644                 0x0000007f, 0x000007ff, 0x0000ffff,
2645                 0x001fffff, 0x03ffffff, 0x7fffffff
2646         };
2647
2648         /* Continuation byte received */
2649         if ((c & 0xc0) == 0x80) {
2650                 /* Unexpected continuation byte? */
2651                 if (!vc->vc_utf_count)
2652                         return 0xfffd;
2653
2654                 vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2655                 vc->vc_npar++;
2656                 if (--vc->vc_utf_count)
2657                         goto need_more_bytes;
2658
2659                 /* Got a whole character */
2660                 c = vc->vc_utf_char;
2661                 /* Reject overlong sequences */
2662                 if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2663                                 c > utf8_length_changes[vc->vc_npar])
2664                         return 0xfffd;
2665
2666                 return vc_sanitize_unicode(c);
2667         }
2668
2669         /* Single ASCII byte or first byte of a sequence received */
2670         if (vc->vc_utf_count) {
2671                 /* Continuation byte expected */
2672                 *rescan = true;
2673                 vc->vc_utf_count = 0;
2674                 return 0xfffd;
2675         }
2676
2677         /* Nothing to do if an ASCII byte was received */
2678         if (c <= 0x7f)
2679                 return c;
2680
2681         /* First byte of a multibyte sequence received */
2682         vc->vc_npar = 0;
2683         if ((c & 0xe0) == 0xc0) {
2684                 vc->vc_utf_count = 1;
2685                 vc->vc_utf_char = (c & 0x1f);
2686         } else if ((c & 0xf0) == 0xe0) {
2687                 vc->vc_utf_count = 2;
2688                 vc->vc_utf_char = (c & 0x0f);
2689         } else if ((c & 0xf8) == 0xf0) {
2690                 vc->vc_utf_count = 3;
2691                 vc->vc_utf_char = (c & 0x07);
2692         } else if ((c & 0xfc) == 0xf8) {
2693                 vc->vc_utf_count = 4;
2694                 vc->vc_utf_char = (c & 0x03);
2695         } else if ((c & 0xfe) == 0xfc) {
2696                 vc->vc_utf_count = 5;
2697                 vc->vc_utf_char = (c & 0x01);
2698         } else {
2699                 /* 254 and 255 are invalid */
2700                 return 0xfffd;
2701         }
2702
2703 need_more_bytes:
2704         return -1;
2705 }
2706
2707 static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
2708 {
2709         /* Do no translation at all in control states */
2710         if (vc->vc_state != ESnormal)
2711                 return *c;
2712
2713         if (vc->vc_utf && !vc->vc_disp_ctrl)
2714                 return *c = vc_translate_unicode(vc, *c, rescan);
2715
2716         /* no utf or alternate charset mode */
2717         return vc_translate_ascii(vc, *c);
2718 }
2719
2720 static inline unsigned char vc_invert_attr(const struct vc_data *vc)
2721 {
2722         if (!vc->vc_can_do_color)
2723                 return vc->vc_attr ^ 0x08;
2724
2725         if (vc->vc_hi_font_mask == 0x100)
2726                 return   (vc->vc_attr & 0x11) |
2727                         ((vc->vc_attr & 0xe0) >> 4) |
2728                         ((vc->vc_attr & 0x0e) << 4);
2729
2730         return   (vc->vc_attr & 0x88) |
2731                 ((vc->vc_attr & 0x70) >> 4) |
2732                 ((vc->vc_attr & 0x07) << 4);
2733 }
2734
2735 static bool vc_is_control(struct vc_data *vc, int tc, int c)
2736 {
2737         /*
2738          * A bitmap for codes <32. A bit of 1 indicates that the code
2739          * corresponding to that bit number invokes some special action (such
2740          * as cursor movement) and should not be displayed as a glyph unless
2741          * the disp_ctrl mode is explicitly enabled.
2742          */
2743         static const u32 CTRL_ACTION = 0x0d00ff81;
2744         /* Cannot be overridden by disp_ctrl */
2745         static const u32 CTRL_ALWAYS = 0x0800f501;
2746
2747         if (vc->vc_state != ESnormal)
2748                 return true;
2749
2750         if (!tc)
2751                 return true;
2752
2753         /*
2754          * If the original code was a control character we only allow a glyph
2755          * to be displayed if the code is not normally used (such as for cursor
2756          * movement) or if the disp_ctrl mode has been explicitly enabled.
2757          * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
2758          * displayed as control characters, as the console would be pretty
2759          * useless without them; to display an arbitrary font position use the
2760          * direct-to-font zone in UTF-8 mode.
2761          */
2762         if (c < 32) {
2763                 if (vc->vc_disp_ctrl)
2764                         return CTRL_ALWAYS & BIT(c);
2765                 else
2766                         return vc->vc_utf || (CTRL_ACTION & BIT(c));
2767         }
2768
2769         if (c == 127 && !vc->vc_disp_ctrl)
2770                 return true;
2771
2772         if (c == 128 + 27)
2773                 return true;
2774
2775         return false;
2776 }
2777
2778 static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
2779                 struct vc_draw_region *draw)
2780 {
2781         int next_c;
2782         unsigned char vc_attr = vc->vc_attr;
2783         u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
2784         u8 width = 1;
2785         bool inverse = false;
2786
2787         if (vc->vc_utf && !vc->vc_disp_ctrl) {
2788                 if (is_double_width(c))
2789                         width = 2;
2790         }
2791
2792         /* Now try to find out how to display it */
2793         tc = conv_uni_to_pc(vc, tc);
2794         if (tc & ~charmask) {
2795                 if (tc == -1 || tc == -2)
2796                         return -1; /* nothing to display */
2797
2798                 /* Glyph not found */
2799                 if ((!vc->vc_utf || vc->vc_disp_ctrl || c < 128) &&
2800                                 !(c & ~charmask)) {
2801                         /*
2802                          * In legacy mode use the glyph we get by a 1:1
2803                          * mapping.
2804                          * This would make absolutely no sense with Unicode in
2805                          * mind, but do this for ASCII characters since a font
2806                          * may lack Unicode mapping info and we don't want to
2807                          * end up with having question marks only.
2808                          */
2809                         tc = c;
2810                 } else {
2811                         /*
2812                          * Display U+FFFD. If it's not found, display an inverse
2813                          * question mark.
2814                          */
2815                         tc = conv_uni_to_pc(vc, 0xfffd);
2816                         if (tc < 0) {
2817                                 inverse = true;
2818                                 tc = conv_uni_to_pc(vc, '?');
2819                                 if (tc < 0)
2820                                         tc = '?';
2821
2822                                 vc_attr = vc_invert_attr(vc);
2823                                 con_flush(vc, draw);
2824                         }
2825                 }
2826         }
2827
2828         next_c = c;
2829         while (1) {
2830                 if (vc->vc_need_wrap || vc->vc_decim)
2831                         con_flush(vc, draw);
2832                 if (vc->vc_need_wrap) {
2833                         cr(vc);
2834                         lf(vc);
2835                 }
2836                 if (vc->vc_decim)
2837                         insert_char(vc, 1);
2838                 vc_uniscr_putc(vc, next_c);
2839
2840                 if (himask)
2841                         tc = ((tc & 0x100) ? himask : 0) |
2842                               (tc &  0xff);
2843                 tc |= (vc_attr << 8) & ~himask;
2844
2845                 scr_writew(tc, (u16 *)vc->vc_pos);
2846
2847                 if (con_should_update(vc) && draw->x < 0) {
2848                         draw->x = vc->state.x;
2849                         draw->from = vc->vc_pos;
2850                 }
2851                 if (vc->state.x == vc->vc_cols - 1) {
2852                         vc->vc_need_wrap = vc->vc_decawm;
2853                         draw->to = vc->vc_pos + 2;
2854                 } else {
2855                         vc->state.x++;
2856                         draw->to = (vc->vc_pos += 2);
2857                 }
2858
2859                 if (!--width)
2860                         break;
2861
2862                 /* A space is printed in the second column */
2863                 tc = conv_uni_to_pc(vc, ' ');
2864                 if (tc < 0)
2865                         tc = ' ';
2866                 next_c = ' ';
2867         }
2868         notify_write(vc, c);
2869
2870         if (inverse)
2871                 con_flush(vc, draw);
2872
2873         return 0;
2874 }
2875
2876 /* acquires console_lock */
2877 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2878 {
2879         struct vc_draw_region draw = {
2880                 .x = -1,
2881         };
2882         int c, tc, n = 0;
2883         unsigned int currcons;
2884         struct vc_data *vc;
2885         struct vt_notifier_param param;
2886         bool rescan;
2887
2888         if (in_interrupt())
2889                 return count;
2890
2891         console_lock();
2892         vc = tty->driver_data;
2893         if (vc == NULL) {
2894                 pr_err("vt: argh, driver_data is NULL !\n");
2895                 console_unlock();
2896                 return 0;
2897         }
2898
2899         currcons = vc->vc_num;
2900         if (!vc_cons_allocated(currcons)) {
2901                 /* could this happen? */
2902                 pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2903                 console_unlock();
2904                 return 0;
2905         }
2906
2907
2908         /* undraw cursor first */
2909         if (con_is_fg(vc))
2910                 hide_cursor(vc);
2911
2912         param.vc = vc;
2913
2914         while (!tty->flow.stopped && count) {
2915                 int orig = *buf;
2916                 buf++;
2917                 n++;
2918                 count--;
2919 rescan_last_byte:
2920                 c = orig;
2921                 rescan = false;
2922
2923                 tc = vc_translate(vc, &c, &rescan);
2924                 if (tc == -1)
2925                         continue;
2926
2927                 param.c = tc;
2928                 if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2929                                         &param) == NOTIFY_STOP)
2930                         continue;
2931
2932                 if (vc_is_control(vc, tc, c)) {
2933                         con_flush(vc, &draw);
2934                         do_con_trol(tty, vc, orig);
2935                         continue;
2936                 }
2937
2938                 if (vc_con_write_normal(vc, tc, c, &draw) < 0)
2939                         continue;
2940
2941                 if (rescan)
2942                         goto rescan_last_byte;
2943         }
2944         con_flush(vc, &draw);
2945         vc_uniscr_debug_check(vc);
2946         console_conditional_schedule();
2947         notify_update(vc);
2948         console_unlock();
2949         return n;
2950 }
2951
2952 /*
2953  * This is the console switching callback.
2954  *
2955  * Doing console switching in a process context allows
2956  * us to do the switches asynchronously (needed when we want
2957  * to switch due to a keyboard interrupt).  Synchronization
2958  * with other console code and prevention of re-entrancy is
2959  * ensured with console_lock.
2960  */
2961 static void console_callback(struct work_struct *ignored)
2962 {
2963         console_lock();
2964
2965         if (want_console >= 0) {
2966                 if (want_console != fg_console &&
2967                     vc_cons_allocated(want_console)) {
2968                         hide_cursor(vc_cons[fg_console].d);
2969                         change_console(vc_cons[want_console].d);
2970                         /* we only changed when the console had already
2971                            been allocated - a new console is not created
2972                            in an interrupt routine */
2973                 }
2974                 want_console = -1;
2975         }
2976         if (do_poke_blanked_console) { /* do not unblank for a LED change */
2977                 do_poke_blanked_console = 0;
2978                 poke_blanked_console();
2979         }
2980         if (scrollback_delta) {
2981                 struct vc_data *vc = vc_cons[fg_console].d;
2982                 clear_selection();
2983                 if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2984                         vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2985                 scrollback_delta = 0;
2986         }
2987         if (blank_timer_expired) {
2988                 do_blank_screen(0);
2989                 blank_timer_expired = 0;
2990         }
2991         notify_update(vc_cons[fg_console].d);
2992
2993         console_unlock();
2994 }
2995
2996 int set_console(int nr)
2997 {
2998         struct vc_data *vc = vc_cons[fg_console].d;
2999
3000         if (!vc_cons_allocated(nr) || vt_dont_switch ||
3001                 (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
3002
3003                 /*
3004                  * Console switch will fail in console_callback() or
3005                  * change_console() so there is no point scheduling
3006                  * the callback
3007                  *
3008                  * Existing set_console() users don't check the return
3009                  * value so this shouldn't break anything
3010                  */
3011                 return -EINVAL;
3012         }
3013
3014         want_console = nr;
3015         schedule_console_callback();
3016
3017         return 0;
3018 }
3019
3020 struct tty_driver *console_driver;
3021
3022 #ifdef CONFIG_VT_CONSOLE
3023
3024 /**
3025  * vt_kmsg_redirect() - Sets/gets the kernel message console
3026  * @new:        The new virtual terminal number or -1 if the console should stay
3027  *              unchanged
3028  *
3029  * By default, the kernel messages are always printed on the current virtual
3030  * console. However, the user may modify that default with the
3031  * TIOCL_SETKMSGREDIRECT ioctl call.
3032  *
3033  * This function sets the kernel message console to be @new. It returns the old
3034  * virtual console number. The virtual terminal number 0 (both as parameter and
3035  * return value) means no redirection (i.e. always printed on the currently
3036  * active console).
3037  *
3038  * The parameter -1 means that only the current console is returned, but the
3039  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
3040  * case to make the code more understandable.
3041  *
3042  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
3043  * the parameter and always returns 0.
3044  */
3045 int vt_kmsg_redirect(int new)
3046 {
3047         static int kmsg_con;
3048
3049         if (new != -1)
3050                 return xchg(&kmsg_con, new);
3051         else
3052                 return kmsg_con;
3053 }
3054
3055 /*
3056  *      Console on virtual terminal
3057  *
3058  * The console must be locked when we get here.
3059  */
3060
3061 static void vt_console_print(struct console *co, const char *b, unsigned count)
3062 {
3063         struct vc_data *vc = vc_cons[fg_console].d;
3064         unsigned char c;
3065         static DEFINE_SPINLOCK(printing_lock);
3066         const ushort *start;
3067         ushort start_x, cnt;
3068         int kmsg_console;
3069
3070         /* console busy or not yet initialized */
3071         if (!printable)
3072                 return;
3073         if (!spin_trylock(&printing_lock))
3074                 return;
3075
3076         kmsg_console = vt_get_kmsg_redirect();
3077         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
3078                 vc = vc_cons[kmsg_console - 1].d;
3079
3080         if (!vc_cons_allocated(fg_console)) {
3081                 /* impossible */
3082                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
3083                 goto quit;
3084         }
3085
3086         if (vc->vc_mode != KD_TEXT)
3087                 goto quit;
3088
3089         /* undraw cursor first */
3090         if (con_is_fg(vc))
3091                 hide_cursor(vc);
3092
3093         start = (ushort *)vc->vc_pos;
3094         start_x = vc->state.x;
3095         cnt = 0;
3096         while (count--) {
3097                 c = *b++;
3098                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
3099                         if (cnt && con_is_visible(vc))
3100                                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3101                         cnt = 0;
3102                         if (c == 8) {           /* backspace */
3103                                 bs(vc);
3104                                 start = (ushort *)vc->vc_pos;
3105                                 start_x = vc->state.x;
3106                                 continue;
3107                         }
3108                         if (c != 13)
3109                                 lf(vc);
3110                         cr(vc);
3111                         start = (ushort *)vc->vc_pos;
3112                         start_x = vc->state.x;
3113                         if (c == 10 || c == 13)
3114                                 continue;
3115                 }
3116                 vc_uniscr_putc(vc, c);
3117                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3118                 notify_write(vc, c);
3119                 cnt++;
3120                 if (vc->state.x == vc->vc_cols - 1) {
3121                         vc->vc_need_wrap = 1;
3122                 } else {
3123                         vc->vc_pos += 2;
3124                         vc->state.x++;
3125                 }
3126         }
3127         if (cnt && con_is_visible(vc))
3128                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3129         set_cursor(vc);
3130         notify_update(vc);
3131
3132 quit:
3133         spin_unlock(&printing_lock);
3134 }
3135
3136 static struct tty_driver *vt_console_device(struct console *c, int *index)
3137 {
3138         *index = c->index ? c->index-1 : fg_console;
3139         return console_driver;
3140 }
3141
3142 static struct console vt_console_driver = {
3143         .name           = "tty",
3144         .write          = vt_console_print,
3145         .device         = vt_console_device,
3146         .unblank        = unblank_screen,
3147         .flags          = CON_PRINTBUFFER,
3148         .index          = -1,
3149 };
3150 #endif
3151
3152 /*
3153  *      Handling of Linux-specific VC ioctls
3154  */
3155
3156 /*
3157  * Generally a bit racy with respect to console_lock();.
3158  *
3159  * There are some functions which don't need it.
3160  *
3161  * There are some functions which can sleep for arbitrary periods
3162  * (paste_selection) but we don't need the lock there anyway.
3163  *
3164  * set_selection_user has locking, and definitely needs it
3165  */
3166
3167 int tioclinux(struct tty_struct *tty, unsigned long arg)
3168 {
3169         char type, data;
3170         char __user *p = (char __user *)arg;
3171         int lines;
3172         int ret;
3173
3174         if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3175                 return -EPERM;
3176         if (get_user(type, p))
3177                 return -EFAULT;
3178         ret = 0;
3179
3180         switch (type)
3181         {
3182                 case TIOCL_SETSEL:
3183                         ret = set_selection_user((struct tiocl_selection
3184                                                  __user *)(p+1), tty);
3185                         break;
3186                 case TIOCL_PASTESEL:
3187                         ret = paste_selection(tty);
3188                         break;
3189                 case TIOCL_UNBLANKSCREEN:
3190                         console_lock();
3191                         unblank_screen();
3192                         console_unlock();
3193                         break;
3194                 case TIOCL_SELLOADLUT:
3195                         console_lock();
3196                         ret = sel_loadlut(p);
3197                         console_unlock();
3198                         break;
3199                 case TIOCL_GETSHIFTSTATE:
3200
3201         /*
3202          * Make it possible to react to Shift+Mousebutton.
3203          * Note that 'shift_state' is an undocumented
3204          * kernel-internal variable; programs not closely
3205          * related to the kernel should not use this.
3206          */
3207                         data = vt_get_shift_state();
3208                         ret = put_user(data, p);
3209                         break;
3210                 case TIOCL_GETMOUSEREPORTING:
3211                         console_lock(); /* May be overkill */
3212                         data = mouse_reporting();
3213                         console_unlock();
3214                         ret = put_user(data, p);
3215                         break;
3216                 case TIOCL_SETVESABLANK:
3217                         console_lock();
3218                         ret = set_vesa_blanking(p);
3219                         console_unlock();
3220                         break;
3221                 case TIOCL_GETKMSGREDIRECT:
3222                         data = vt_get_kmsg_redirect();
3223                         ret = put_user(data, p);
3224                         break;
3225                 case TIOCL_SETKMSGREDIRECT:
3226                         if (!capable(CAP_SYS_ADMIN)) {
3227                                 ret = -EPERM;
3228                         } else {
3229                                 if (get_user(data, p+1))
3230                                         ret = -EFAULT;
3231                                 else
3232                                         vt_kmsg_redirect(data);
3233                         }
3234                         break;
3235                 case TIOCL_GETFGCONSOLE:
3236                         /* No locking needed as this is a transiently
3237                            correct return anyway if the caller hasn't
3238                            disabled switching */
3239                         ret = fg_console;
3240                         break;
3241                 case TIOCL_SCROLLCONSOLE:
3242                         if (get_user(lines, (s32 __user *)(p+4))) {
3243                                 ret = -EFAULT;
3244                         } else {
3245                                 /* Need the console lock here. Note that lots
3246                                    of other calls need fixing before the lock
3247                                    is actually useful ! */
3248                                 console_lock();
3249                                 scrollfront(vc_cons[fg_console].d, lines);
3250                                 console_unlock();
3251                                 ret = 0;
3252                         }
3253                         break;
3254                 case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
3255                         console_lock();
3256                         ignore_poke = 1;
3257                         do_blank_screen(0);
3258                         console_unlock();
3259                         break;
3260                 case TIOCL_BLANKEDSCREEN:
3261                         ret = console_blanked;
3262                         break;
3263                 default:
3264                         ret = -EINVAL;
3265                         break;
3266         }
3267         return ret;
3268 }
3269
3270 /*
3271  * /dev/ttyN handling
3272  */
3273
3274 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3275 {
3276         int     retval;
3277
3278         retval = do_con_write(tty, buf, count);
3279         con_flush_chars(tty);
3280
3281         return retval;
3282 }
3283
3284 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3285 {
3286         return do_con_write(tty, &ch, 1);
3287 }
3288
3289 static unsigned int con_write_room(struct tty_struct *tty)
3290 {
3291         if (tty->flow.stopped)
3292                 return 0;
3293         return 32768;           /* No limit, really; we're not buffering */
3294 }
3295
3296 /*
3297  * con_throttle and con_unthrottle are only used for
3298  * paste_selection(), which has to stuff in a large number of
3299  * characters...
3300  */
3301 static void con_throttle(struct tty_struct *tty)
3302 {
3303 }
3304
3305 static void con_unthrottle(struct tty_struct *tty)
3306 {
3307         struct vc_data *vc = tty->driver_data;
3308
3309         wake_up_interruptible(&vc->paste_wait);
3310 }
3311
3312 /*
3313  * Turn the Scroll-Lock LED on when the tty is stopped
3314  */
3315 static void con_stop(struct tty_struct *tty)
3316 {
3317         int console_num;
3318         if (!tty)
3319                 return;
3320         console_num = tty->index;
3321         if (!vc_cons_allocated(console_num))
3322                 return;
3323         vt_kbd_con_stop(console_num);
3324 }
3325
3326 /*
3327  * Turn the Scroll-Lock LED off when the console is started
3328  */
3329 static void con_start(struct tty_struct *tty)
3330 {
3331         int console_num;
3332         if (!tty)
3333                 return;
3334         console_num = tty->index;
3335         if (!vc_cons_allocated(console_num))
3336                 return;
3337         vt_kbd_con_start(console_num);
3338 }
3339
3340 static void con_flush_chars(struct tty_struct *tty)
3341 {
3342         struct vc_data *vc;
3343
3344         if (in_interrupt())     /* from flush_to_ldisc */
3345                 return;
3346
3347         /* if we race with con_close(), vt may be null */
3348         console_lock();
3349         vc = tty->driver_data;
3350         if (vc)
3351                 set_cursor(vc);
3352         console_unlock();
3353 }
3354
3355 /*
3356  * Allocate the console screen memory.
3357  */
3358 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3359 {
3360         unsigned int currcons = tty->index;
3361         struct vc_data *vc;
3362         int ret;
3363
3364         console_lock();
3365         ret = vc_allocate(currcons);
3366         if (ret)
3367                 goto unlock;
3368
3369         vc = vc_cons[currcons].d;
3370
3371         /* Still being freed */
3372         if (vc->port.tty) {
3373                 ret = -ERESTARTSYS;
3374                 goto unlock;
3375         }
3376
3377         ret = tty_port_install(&vc->port, driver, tty);
3378         if (ret)
3379                 goto unlock;
3380
3381         tty->driver_data = vc;
3382         vc->port.tty = tty;
3383         tty_port_get(&vc->port);
3384
3385         if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3386                 tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3387                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3388         }
3389         if (vc->vc_utf)
3390                 tty->termios.c_iflag |= IUTF8;
3391         else
3392                 tty->termios.c_iflag &= ~IUTF8;
3393 unlock:
3394         console_unlock();
3395         return ret;
3396 }
3397
3398 static int con_open(struct tty_struct *tty, struct file *filp)
3399 {
3400         /* everything done in install */
3401         return 0;
3402 }
3403
3404
3405 static void con_close(struct tty_struct *tty, struct file *filp)
3406 {
3407         /* Nothing to do - we defer to shutdown */
3408 }
3409
3410 static void con_shutdown(struct tty_struct *tty)
3411 {
3412         struct vc_data *vc = tty->driver_data;
3413         BUG_ON(vc == NULL);
3414         console_lock();
3415         vc->port.tty = NULL;
3416         console_unlock();
3417 }
3418
3419 static void con_cleanup(struct tty_struct *tty)
3420 {
3421         struct vc_data *vc = tty->driver_data;
3422
3423         tty_port_put(&vc->port);
3424 }
3425
3426 static int default_color           = 7; /* white */
3427 static int default_italic_color    = 2; // green (ASCII)
3428 static int default_underline_color = 3; // cyan (ASCII)
3429 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3430 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3431 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3432
3433 static void vc_init(struct vc_data *vc, unsigned int rows,
3434                     unsigned int cols, int do_clear)
3435 {
3436         int j, k ;
3437
3438         vc->vc_cols = cols;
3439         vc->vc_rows = rows;
3440         vc->vc_size_row = cols << 1;
3441         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3442
3443         set_origin(vc);
3444         vc->vc_pos = vc->vc_origin;
3445         reset_vc(vc);
3446         for (j=k=0; j<16; j++) {
3447                 vc->vc_palette[k++] = default_red[j] ;
3448                 vc->vc_palette[k++] = default_grn[j] ;
3449                 vc->vc_palette[k++] = default_blu[j] ;
3450         }
3451         vc->vc_def_color       = default_color;
3452         vc->vc_ulcolor         = default_underline_color;
3453         vc->vc_itcolor         = default_italic_color;
3454         vc->vc_halfcolor       = 0x08;   /* grey */
3455         init_waitqueue_head(&vc->paste_wait);
3456         reset_terminal(vc, do_clear);
3457 }
3458
3459 /*
3460  * This routine initializes console interrupts, and does nothing
3461  * else. If you want the screen to clear, call tty_write with
3462  * the appropriate escape-sequence.
3463  */
3464
3465 static int __init con_init(void)
3466 {
3467         const char *display_desc = NULL;
3468         struct vc_data *vc;
3469         unsigned int currcons = 0, i;
3470
3471         console_lock();
3472
3473         if (!conswitchp)
3474                 conswitchp = &dummy_con;
3475         display_desc = conswitchp->con_startup();
3476         if (!display_desc) {
3477                 fg_console = 0;
3478                 console_unlock();
3479                 return 0;
3480         }
3481
3482         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3483                 struct con_driver *con_driver = &registered_con_driver[i];
3484
3485                 if (con_driver->con == NULL) {
3486                         con_driver->con = conswitchp;
3487                         con_driver->desc = display_desc;
3488                         con_driver->flag = CON_DRIVER_FLAG_INIT;
3489                         con_driver->first = 0;
3490                         con_driver->last = MAX_NR_CONSOLES - 1;
3491                         break;
3492                 }
3493         }
3494
3495         for (i = 0; i < MAX_NR_CONSOLES; i++)
3496                 con_driver_map[i] = conswitchp;
3497
3498         if (blankinterval) {
3499                 blank_state = blank_normal_wait;
3500                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3501         }
3502
3503         for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3504                 vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3505                 INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3506                 tty_port_init(&vc->port);
3507                 visual_init(vc, currcons, 1);
3508                 /* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3509                 vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3510                 vc_init(vc, vc->vc_rows, vc->vc_cols,
3511                         currcons || !vc->vc_sw->con_save_screen);
3512         }
3513         currcons = fg_console = 0;
3514         master_display_fg = vc = vc_cons[currcons].d;
3515         set_origin(vc);
3516         save_screen(vc);
3517         gotoxy(vc, vc->state.x, vc->state.y);
3518         csi_J(vc, 0);
3519         update_screen(vc);
3520         pr_info("Console: %s %s %dx%d\n",
3521                 vc->vc_can_do_color ? "colour" : "mono",
3522                 display_desc, vc->vc_cols, vc->vc_rows);
3523         printable = 1;
3524
3525         console_unlock();
3526
3527 #ifdef CONFIG_VT_CONSOLE
3528         register_console(&vt_console_driver);
3529 #endif
3530         return 0;
3531 }
3532 console_initcall(con_init);
3533
3534 static const struct tty_operations con_ops = {
3535         .install = con_install,
3536         .open = con_open,
3537         .close = con_close,
3538         .write = con_write,
3539         .write_room = con_write_room,
3540         .put_char = con_put_char,
3541         .flush_chars = con_flush_chars,
3542         .ioctl = vt_ioctl,
3543 #ifdef CONFIG_COMPAT
3544         .compat_ioctl = vt_compat_ioctl,
3545 #endif
3546         .stop = con_stop,
3547         .start = con_start,
3548         .throttle = con_throttle,
3549         .unthrottle = con_unthrottle,
3550         .resize = vt_resize,
3551         .shutdown = con_shutdown,
3552         .cleanup = con_cleanup,
3553 };
3554
3555 static struct cdev vc0_cdev;
3556
3557 static ssize_t show_tty_active(struct device *dev,
3558                                 struct device_attribute *attr, char *buf)
3559 {
3560         return sprintf(buf, "tty%d\n", fg_console + 1);
3561 }
3562 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3563
3564 static struct attribute *vt_dev_attrs[] = {
3565         &dev_attr_active.attr,
3566         NULL
3567 };
3568
3569 ATTRIBUTE_GROUPS(vt_dev);
3570
3571 int __init vty_init(const struct file_operations *console_fops)
3572 {
3573         cdev_init(&vc0_cdev, console_fops);
3574         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3575             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3576                 panic("Couldn't register /dev/tty0 driver\n");
3577         tty0dev = device_create_with_groups(tty_class, NULL,
3578                                             MKDEV(TTY_MAJOR, 0), NULL,
3579                                             vt_dev_groups, "tty0");
3580         if (IS_ERR(tty0dev))
3581                 tty0dev = NULL;
3582
3583         vcs_init();
3584
3585         console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3586         if (!console_driver)
3587                 panic("Couldn't allocate console driver\n");
3588
3589         console_driver->name = "tty";
3590         console_driver->name_base = 1;
3591         console_driver->major = TTY_MAJOR;
3592         console_driver->minor_start = 1;
3593         console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3594         console_driver->init_termios = tty_std_termios;
3595         if (default_utf8)
3596                 console_driver->init_termios.c_iflag |= IUTF8;
3597         console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3598         tty_set_operations(console_driver, &con_ops);
3599         if (tty_register_driver(console_driver))
3600                 panic("Couldn't register console driver\n");
3601         kbd_init();
3602         console_map_init();
3603 #ifdef CONFIG_MDA_CONSOLE
3604         mda_console_init();
3605 #endif
3606         return 0;
3607 }
3608
3609 #ifndef VT_SINGLE_DRIVER
3610
3611 static struct class *vtconsole_class;
3612
3613 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3614                            int deflt)
3615 {
3616         struct module *owner = csw->owner;
3617         const char *desc = NULL;
3618         struct con_driver *con_driver;
3619         int i, j = -1, k = -1, retval = -ENODEV;
3620
3621         if (!try_module_get(owner))
3622                 return -ENODEV;
3623
3624         WARN_CONSOLE_UNLOCKED();
3625
3626         /* check if driver is registered */
3627         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3628                 con_driver = &registered_con_driver[i];
3629
3630                 if (con_driver->con == csw) {
3631                         desc = con_driver->desc;
3632                         retval = 0;
3633                         break;
3634                 }
3635         }
3636
3637         if (retval)
3638                 goto err;
3639
3640         if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3641                 csw->con_startup();
3642                 con_driver->flag |= CON_DRIVER_FLAG_INIT;
3643         }
3644
3645         if (deflt) {
3646                 if (conswitchp)
3647                         module_put(conswitchp->owner);
3648
3649                 __module_get(owner);
3650                 conswitchp = csw;
3651         }
3652
3653         first = max(first, con_driver->first);
3654         last = min(last, con_driver->last);
3655
3656         for (i = first; i <= last; i++) {
3657                 int old_was_color;
3658                 struct vc_data *vc = vc_cons[i].d;
3659
3660                 if (con_driver_map[i])
3661                         module_put(con_driver_map[i]->owner);
3662                 __module_get(owner);
3663                 con_driver_map[i] = csw;
3664
3665                 if (!vc || !vc->vc_sw)
3666                         continue;
3667
3668                 j = i;
3669
3670                 if (con_is_visible(vc)) {
3671                         k = i;
3672                         save_screen(vc);
3673                 }
3674
3675                 old_was_color = vc->vc_can_do_color;
3676                 vc->vc_sw->con_deinit(vc);
3677                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3678                 visual_init(vc, i, 0);
3679                 set_origin(vc);
3680                 update_attr(vc);
3681
3682                 /* If the console changed between mono <-> color, then
3683                  * the attributes in the screenbuf will be wrong.  The
3684                  * following resets all attributes to something sane.
3685                  */
3686                 if (old_was_color != vc->vc_can_do_color)
3687                         clear_buffer_attributes(vc);
3688         }
3689
3690         pr_info("Console: switching ");
3691         if (!deflt)
3692                 pr_cont("consoles %d-%d ", first + 1, last + 1);
3693         if (j >= 0) {
3694                 struct vc_data *vc = vc_cons[j].d;
3695
3696                 pr_cont("to %s %s %dx%d\n",
3697                         vc->vc_can_do_color ? "colour" : "mono",
3698                         desc, vc->vc_cols, vc->vc_rows);
3699
3700                 if (k >= 0) {
3701                         vc = vc_cons[k].d;
3702                         update_screen(vc);
3703                 }
3704         } else {
3705                 pr_cont("to %s\n", desc);
3706         }
3707
3708         retval = 0;
3709 err:
3710         module_put(owner);
3711         return retval;
3712 };
3713
3714
3715 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3716 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3717 {
3718         struct module *owner = csw->owner;
3719         const struct consw *defcsw = NULL;
3720         struct con_driver *con_driver = NULL, *con_back = NULL;
3721         int i, retval = -ENODEV;
3722
3723         if (!try_module_get(owner))
3724                 return -ENODEV;
3725
3726         WARN_CONSOLE_UNLOCKED();
3727
3728         /* check if driver is registered and if it is unbindable */
3729         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3730                 con_driver = &registered_con_driver[i];
3731
3732                 if (con_driver->con == csw &&
3733                     con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3734                         retval = 0;
3735                         break;
3736                 }
3737         }
3738
3739         if (retval)
3740                 goto err;
3741
3742         retval = -ENODEV;
3743
3744         /* check if backup driver exists */
3745         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3746                 con_back = &registered_con_driver[i];
3747
3748                 if (con_back->con && con_back->con != csw) {
3749                         defcsw = con_back->con;
3750                         retval = 0;
3751                         break;
3752                 }
3753         }
3754
3755         if (retval)
3756                 goto err;
3757
3758         if (!con_is_bound(csw))
3759                 goto err;
3760
3761         first = max(first, con_driver->first);
3762         last = min(last, con_driver->last);
3763
3764         for (i = first; i <= last; i++) {
3765                 if (con_driver_map[i] == csw) {
3766                         module_put(csw->owner);
3767                         con_driver_map[i] = NULL;
3768                 }
3769         }
3770
3771         if (!con_is_bound(defcsw)) {
3772                 const struct consw *defconsw = conswitchp;
3773
3774                 defcsw->con_startup();
3775                 con_back->flag |= CON_DRIVER_FLAG_INIT;
3776                 /*
3777                  * vgacon may change the default driver to point
3778                  * to dummycon, we restore it here...
3779                  */
3780                 conswitchp = defconsw;
3781         }
3782
3783         if (!con_is_bound(csw))
3784                 con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3785
3786         /* ignore return value, binding should not fail */
3787         do_bind_con_driver(defcsw, first, last, deflt);
3788 err:
3789         module_put(owner);
3790         return retval;
3791
3792 }
3793 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3794
3795 static int vt_bind(struct con_driver *con)
3796 {
3797         const struct consw *defcsw = NULL, *csw = NULL;
3798         int i, more = 1, first = -1, last = -1, deflt = 0;
3799
3800         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3801                 goto err;
3802
3803         csw = con->con;
3804
3805         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3806                 struct con_driver *con = &registered_con_driver[i];
3807
3808                 if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3809                         defcsw = con->con;
3810                         break;
3811                 }
3812         }
3813
3814         if (!defcsw)
3815                 goto err;
3816
3817         while (more) {
3818                 more = 0;
3819
3820                 for (i = con->first; i <= con->last; i++) {
3821                         if (con_driver_map[i] == defcsw) {
3822                                 if (first == -1)
3823                                         first = i;
3824                                 last = i;
3825                                 more = 1;
3826                         } else if (first != -1)
3827                                 break;
3828                 }
3829
3830                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3831                         deflt = 1;
3832
3833                 if (first != -1)
3834                         do_bind_con_driver(csw, first, last, deflt);
3835
3836                 first = -1;
3837                 last = -1;
3838                 deflt = 0;
3839         }
3840
3841 err:
3842         return 0;
3843 }
3844
3845 static int vt_unbind(struct con_driver *con)
3846 {
3847         const struct consw *csw = NULL;
3848         int i, more = 1, first = -1, last = -1, deflt = 0;
3849         int ret;
3850
3851         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3852                 goto err;
3853
3854         csw = con->con;
3855
3856         while (more) {
3857                 more = 0;
3858
3859                 for (i = con->first; i <= con->last; i++) {
3860                         if (con_driver_map[i] == csw) {
3861                                 if (first == -1)
3862                                         first = i;
3863                                 last = i;
3864                                 more = 1;
3865                         } else if (first != -1)
3866                                 break;
3867                 }
3868
3869                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3870                         deflt = 1;
3871
3872                 if (first != -1) {
3873                         ret = do_unbind_con_driver(csw, first, last, deflt);
3874                         if (ret != 0)
3875                                 return ret;
3876                 }
3877
3878                 first = -1;
3879                 last = -1;
3880                 deflt = 0;
3881         }
3882
3883 err:
3884         return 0;
3885 }
3886 #else
3887 static inline int vt_bind(struct con_driver *con)
3888 {
3889         return 0;
3890 }
3891 static inline int vt_unbind(struct con_driver *con)
3892 {
3893         return 0;
3894 }
3895 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3896
3897 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3898                           const char *buf, size_t count)
3899 {
3900         struct con_driver *con = dev_get_drvdata(dev);
3901         int bind = simple_strtoul(buf, NULL, 0);
3902
3903         console_lock();
3904
3905         if (bind)
3906                 vt_bind(con);
3907         else
3908                 vt_unbind(con);
3909
3910         console_unlock();
3911
3912         return count;
3913 }
3914
3915 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3916                          char *buf)
3917 {
3918         struct con_driver *con = dev_get_drvdata(dev);
3919         int bind;
3920
3921         console_lock();
3922         bind = con_is_bound(con->con);
3923         console_unlock();
3924
3925         return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3926 }
3927
3928 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3929                          char *buf)
3930 {
3931         struct con_driver *con = dev_get_drvdata(dev);
3932
3933         return snprintf(buf, PAGE_SIZE, "%s %s\n",
3934                         (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3935                          con->desc);
3936
3937 }
3938
3939 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3940 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3941
3942 static struct attribute *con_dev_attrs[] = {
3943         &dev_attr_bind.attr,
3944         &dev_attr_name.attr,
3945         NULL
3946 };
3947
3948 ATTRIBUTE_GROUPS(con_dev);
3949
3950 static int vtconsole_init_device(struct con_driver *con)
3951 {
3952         con->flag |= CON_DRIVER_FLAG_ATTR;
3953         return 0;
3954 }
3955
3956 static void vtconsole_deinit_device(struct con_driver *con)
3957 {
3958         con->flag &= ~CON_DRIVER_FLAG_ATTR;
3959 }
3960
3961 /**
3962  * con_is_bound - checks if driver is bound to the console
3963  * @csw: console driver
3964  *
3965  * RETURNS: zero if unbound, nonzero if bound
3966  *
3967  * Drivers can call this and if zero, they should release
3968  * all resources allocated on con_startup()
3969  */
3970 int con_is_bound(const struct consw *csw)
3971 {
3972         int i, bound = 0;
3973
3974         WARN_CONSOLE_UNLOCKED();
3975
3976         for (i = 0; i < MAX_NR_CONSOLES; i++) {
3977                 if (con_driver_map[i] == csw) {
3978                         bound = 1;
3979                         break;
3980                 }
3981         }
3982
3983         return bound;
3984 }
3985 EXPORT_SYMBOL(con_is_bound);
3986
3987 /**
3988  * con_is_visible - checks whether the current console is visible
3989  * @vc: virtual console
3990  *
3991  * RETURNS: zero if not visible, nonzero if visible
3992  */
3993 bool con_is_visible(const struct vc_data *vc)
3994 {
3995         WARN_CONSOLE_UNLOCKED();
3996
3997         return *vc->vc_display_fg == vc;
3998 }
3999 EXPORT_SYMBOL(con_is_visible);
4000
4001 /**
4002  * con_debug_enter - prepare the console for the kernel debugger
4003  * @vc: virtual console
4004  *
4005  * Called when the console is taken over by the kernel debugger, this
4006  * function needs to save the current console state, then put the console
4007  * into a state suitable for the kernel debugger.
4008  *
4009  * RETURNS:
4010  * Zero on success, nonzero if a failure occurred when trying to prepare
4011  * the console for the debugger.
4012  */
4013 int con_debug_enter(struct vc_data *vc)
4014 {
4015         int ret = 0;
4016
4017         saved_fg_console = fg_console;
4018         saved_last_console = last_console;
4019         saved_want_console = want_console;
4020         saved_vc_mode = vc->vc_mode;
4021         saved_console_blanked = console_blanked;
4022         vc->vc_mode = KD_TEXT;
4023         console_blanked = 0;
4024         if (vc->vc_sw->con_debug_enter)
4025                 ret = vc->vc_sw->con_debug_enter(vc);
4026 #ifdef CONFIG_KGDB_KDB
4027         /* Set the initial LINES variable if it is not already set */
4028         if (vc->vc_rows < 999) {
4029                 int linecount;
4030                 char lns[4];
4031                 const char *setargs[3] = {
4032                         "set",
4033                         "LINES",
4034                         lns,
4035                 };
4036                 if (kdbgetintenv(setargs[0], &linecount)) {
4037                         snprintf(lns, 4, "%i", vc->vc_rows);
4038                         kdb_set(2, setargs);
4039                 }
4040         }
4041         if (vc->vc_cols < 999) {
4042                 int colcount;
4043                 char cols[4];
4044                 const char *setargs[3] = {
4045                         "set",
4046                         "COLUMNS",
4047                         cols,
4048                 };
4049                 if (kdbgetintenv(setargs[0], &colcount)) {
4050                         snprintf(cols, 4, "%i", vc->vc_cols);
4051                         kdb_set(2, setargs);
4052                 }
4053         }
4054 #endif /* CONFIG_KGDB_KDB */
4055         return ret;
4056 }
4057 EXPORT_SYMBOL_GPL(con_debug_enter);
4058
4059 /**
4060  * con_debug_leave - restore console state
4061  *
4062  * Restore the console state to what it was before the kernel debugger
4063  * was invoked.
4064  *
4065  * RETURNS:
4066  * Zero on success, nonzero if a failure occurred when trying to restore
4067  * the console.
4068  */
4069 int con_debug_leave(void)
4070 {
4071         struct vc_data *vc;
4072         int ret = 0;
4073
4074         fg_console = saved_fg_console;
4075         last_console = saved_last_console;
4076         want_console = saved_want_console;
4077         console_blanked = saved_console_blanked;
4078         vc_cons[fg_console].d->vc_mode = saved_vc_mode;
4079
4080         vc = vc_cons[fg_console].d;
4081         if (vc->vc_sw->con_debug_leave)
4082                 ret = vc->vc_sw->con_debug_leave(vc);
4083         return ret;
4084 }
4085 EXPORT_SYMBOL_GPL(con_debug_leave);
4086
4087 static int do_register_con_driver(const struct consw *csw, int first, int last)
4088 {
4089         struct module *owner = csw->owner;
4090         struct con_driver *con_driver;
4091         const char *desc;
4092         int i, retval;
4093
4094         WARN_CONSOLE_UNLOCKED();
4095
4096         if (!try_module_get(owner))
4097                 return -ENODEV;
4098
4099         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4100                 con_driver = &registered_con_driver[i];
4101
4102                 /* already registered */
4103                 if (con_driver->con == csw) {
4104                         retval = -EBUSY;
4105                         goto err;
4106                 }
4107         }
4108
4109         desc = csw->con_startup();
4110         if (!desc) {
4111                 retval = -ENODEV;
4112                 goto err;
4113         }
4114
4115         retval = -EINVAL;
4116
4117         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4118                 con_driver = &registered_con_driver[i];
4119
4120                 if (con_driver->con == NULL &&
4121                     !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
4122                         con_driver->con = csw;
4123                         con_driver->desc = desc;
4124                         con_driver->node = i;
4125                         con_driver->flag = CON_DRIVER_FLAG_MODULE |
4126                                            CON_DRIVER_FLAG_INIT;
4127                         con_driver->first = first;
4128                         con_driver->last = last;
4129                         retval = 0;
4130                         break;
4131                 }
4132         }
4133
4134         if (retval)
4135                 goto err;
4136
4137         con_driver->dev =
4138                 device_create_with_groups(vtconsole_class, NULL,
4139                                           MKDEV(0, con_driver->node),
4140                                           con_driver, con_dev_groups,
4141                                           "vtcon%i", con_driver->node);
4142         if (IS_ERR(con_driver->dev)) {
4143                 pr_warn("Unable to create device for %s; errno = %ld\n",
4144                         con_driver->desc, PTR_ERR(con_driver->dev));
4145                 con_driver->dev = NULL;
4146         } else {
4147                 vtconsole_init_device(con_driver);
4148         }
4149
4150 err:
4151         module_put(owner);
4152         return retval;
4153 }
4154
4155
4156 /**
4157  * do_unregister_con_driver - unregister console driver from console layer
4158  * @csw: console driver
4159  *
4160  * DESCRIPTION: All drivers that registers to the console layer must
4161  * call this function upon exit, or if the console driver is in a state
4162  * where it won't be able to handle console services, such as the
4163  * framebuffer console without loaded framebuffer drivers.
4164  *
4165  * The driver must unbind first prior to unregistration.
4166  */
4167 int do_unregister_con_driver(const struct consw *csw)
4168 {
4169         int i;
4170
4171         /* cannot unregister a bound driver */
4172         if (con_is_bound(csw))
4173                 return -EBUSY;
4174
4175         if (csw == conswitchp)
4176                 return -EINVAL;
4177
4178         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4179                 struct con_driver *con_driver = &registered_con_driver[i];
4180
4181                 if (con_driver->con == csw) {
4182                         /*
4183                          * Defer the removal of the sysfs entries since that
4184                          * will acquire the kernfs s_active lock and we can't
4185                          * acquire this lock while holding the console lock:
4186                          * the unbind sysfs entry imposes already the opposite
4187                          * order. Reset con already here to prevent any later
4188                          * lookup to succeed and mark this slot as zombie, so
4189                          * it won't get reused until we complete the removal
4190                          * in the deferred work.
4191                          */
4192                         con_driver->con = NULL;
4193                         con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4194                         schedule_work(&con_driver_unregister_work);
4195
4196                         return 0;
4197                 }
4198         }
4199
4200         return -ENODEV;
4201 }
4202 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4203
4204 static void con_driver_unregister_callback(struct work_struct *ignored)
4205 {
4206         int i;
4207
4208         console_lock();
4209
4210         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4211                 struct con_driver *con_driver = &registered_con_driver[i];
4212
4213                 if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4214                         continue;
4215
4216                 console_unlock();
4217
4218                 vtconsole_deinit_device(con_driver);
4219                 device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4220
4221                 console_lock();
4222
4223                 if (WARN_ON_ONCE(con_driver->con))
4224                         con_driver->con = NULL;
4225                 con_driver->desc = NULL;
4226                 con_driver->dev = NULL;
4227                 con_driver->node = 0;
4228                 WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4229                 con_driver->flag = 0;
4230                 con_driver->first = 0;
4231                 con_driver->last = 0;
4232         }
4233
4234         console_unlock();
4235 }
4236
4237 /*
4238  *      If we support more console drivers, this function is used
4239  *      when a driver wants to take over some existing consoles
4240  *      and become default driver for newly opened ones.
4241  *
4242  *      do_take_over_console is basically a register followed by bind
4243  */
4244 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4245 {
4246         int err;
4247
4248         err = do_register_con_driver(csw, first, last);
4249         /*
4250          * If we get an busy error we still want to bind the console driver
4251          * and return success, as we may have unbound the console driver
4252          * but not unregistered it.
4253          */
4254         if (err == -EBUSY)
4255                 err = 0;
4256         if (!err)
4257                 do_bind_con_driver(csw, first, last, deflt);
4258
4259         return err;
4260 }
4261 EXPORT_SYMBOL_GPL(do_take_over_console);
4262
4263
4264 /*
4265  * give_up_console is a wrapper to unregister_con_driver. It will only
4266  * work if driver is fully unbound.
4267  */
4268 void give_up_console(const struct consw *csw)
4269 {
4270         console_lock();
4271         do_unregister_con_driver(csw);
4272         console_unlock();
4273 }
4274
4275 static int __init vtconsole_class_init(void)
4276 {
4277         int i;
4278
4279         vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4280         if (IS_ERR(vtconsole_class)) {
4281                 pr_warn("Unable to create vt console class; errno = %ld\n",
4282                         PTR_ERR(vtconsole_class));
4283                 vtconsole_class = NULL;
4284         }
4285
4286         /* Add system drivers to sysfs */
4287         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4288                 struct con_driver *con = &registered_con_driver[i];
4289
4290                 if (con->con && !con->dev) {
4291                         con->dev =
4292                                 device_create_with_groups(vtconsole_class, NULL,
4293                                                           MKDEV(0, con->node),
4294                                                           con, con_dev_groups,
4295                                                           "vtcon%i", con->node);
4296
4297                         if (IS_ERR(con->dev)) {
4298                                 pr_warn("Unable to create device for %s; errno = %ld\n",
4299                                         con->desc, PTR_ERR(con->dev));
4300                                 con->dev = NULL;
4301                         } else {
4302                                 vtconsole_init_device(con);
4303                         }
4304                 }
4305         }
4306
4307         return 0;
4308 }
4309 postcore_initcall(vtconsole_class_init);
4310
4311 #endif
4312
4313 /*
4314  *      Screen blanking
4315  */
4316
4317 static int set_vesa_blanking(char __user *p)
4318 {
4319         unsigned int mode;
4320
4321         if (get_user(mode, p + 1))
4322                 return -EFAULT;
4323
4324         vesa_blank_mode = (mode < 4) ? mode : 0;
4325         return 0;
4326 }
4327
4328 void do_blank_screen(int entering_gfx)
4329 {
4330         struct vc_data *vc = vc_cons[fg_console].d;
4331         int i;
4332
4333         might_sleep();
4334
4335         WARN_CONSOLE_UNLOCKED();
4336
4337         if (console_blanked) {
4338                 if (blank_state == blank_vesa_wait) {
4339                         blank_state = blank_off;
4340                         vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4341                 }
4342                 return;
4343         }
4344
4345         /* entering graphics mode? */
4346         if (entering_gfx) {
4347                 hide_cursor(vc);
4348                 save_screen(vc);
4349                 vc->vc_sw->con_blank(vc, -1, 1);
4350                 console_blanked = fg_console + 1;
4351                 blank_state = blank_off;
4352                 set_origin(vc);
4353                 return;
4354         }
4355
4356         blank_state = blank_off;
4357
4358         /* don't blank graphics */
4359         if (vc->vc_mode != KD_TEXT) {
4360                 console_blanked = fg_console + 1;
4361                 return;
4362         }
4363
4364         hide_cursor(vc);
4365         del_timer_sync(&console_timer);
4366         blank_timer_expired = 0;
4367
4368         save_screen(vc);
4369         /* In case we need to reset origin, blanking hook returns 1 */
4370         i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4371         console_blanked = fg_console + 1;
4372         if (i)
4373                 set_origin(vc);
4374
4375         if (console_blank_hook && console_blank_hook(1))
4376                 return;
4377
4378         if (vesa_off_interval && vesa_blank_mode) {
4379                 blank_state = blank_vesa_wait;
4380                 mod_timer(&console_timer, jiffies + vesa_off_interval);
4381         }
4382         vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4383 }
4384 EXPORT_SYMBOL(do_blank_screen);
4385
4386 /*
4387  * Called by timer as well as from vt_console_driver
4388  */
4389 void do_unblank_screen(int leaving_gfx)
4390 {
4391         struct vc_data *vc;
4392
4393         /* This should now always be called from a "sane" (read: can schedule)
4394          * context for the sake of the low level drivers, except in the special
4395          * case of oops_in_progress
4396          */
4397         if (!oops_in_progress)
4398                 might_sleep();
4399
4400         WARN_CONSOLE_UNLOCKED();
4401
4402         ignore_poke = 0;
4403         if (!console_blanked)
4404                 return;
4405         if (!vc_cons_allocated(fg_console)) {
4406                 /* impossible */
4407                 pr_warn("unblank_screen: tty %d not allocated ??\n",
4408                         fg_console + 1);
4409                 return;
4410         }
4411         vc = vc_cons[fg_console].d;
4412         if (vc->vc_mode != KD_TEXT)
4413                 return; /* but leave console_blanked != 0 */
4414
4415         if (blankinterval) {
4416                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4417                 blank_state = blank_normal_wait;
4418         }
4419
4420         console_blanked = 0;
4421         if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4422                 /* Low-level driver cannot restore -> do it ourselves */
4423                 update_screen(vc);
4424         if (console_blank_hook)
4425                 console_blank_hook(0);
4426         set_palette(vc);
4427         set_cursor(vc);
4428         vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4429 }
4430 EXPORT_SYMBOL(do_unblank_screen);
4431
4432 /*
4433  * This is called by the outside world to cause a forced unblank, mostly for
4434  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4435  * call it with 1 as an argument and so force a mode restore... that may kill
4436  * X or at least garbage the screen but would also make the Oops visible...
4437  */
4438 void unblank_screen(void)
4439 {
4440         do_unblank_screen(0);
4441 }
4442
4443 /*
4444  * We defer the timer blanking to work queue so it can take the console mutex
4445  * (console operations can still happen at irq time, but only from printk which
4446  * has the console mutex. Not perfect yet, but better than no locking
4447  */
4448 static void blank_screen_t(struct timer_list *unused)
4449 {
4450         blank_timer_expired = 1;
4451         schedule_work(&console_work);
4452 }
4453
4454 void poke_blanked_console(void)
4455 {
4456         WARN_CONSOLE_UNLOCKED();
4457
4458         /* Add this so we quickly catch whoever might call us in a non
4459          * safe context. Nowadays, unblank_screen() isn't to be called in
4460          * atomic contexts and is allowed to schedule (with the special case
4461          * of oops_in_progress, but that isn't of any concern for this
4462          * function. --BenH.
4463          */
4464         might_sleep();
4465
4466         /* This isn't perfectly race free, but a race here would be mostly harmless,
4467          * at worst, we'll do a spurious blank and it's unlikely
4468          */
4469         del_timer(&console_timer);
4470         blank_timer_expired = 0;
4471
4472         if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4473                 return;
4474         if (console_blanked)
4475                 unblank_screen();
4476         else if (blankinterval) {
4477                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4478                 blank_state = blank_normal_wait;
4479         }
4480 }
4481
4482 /*
4483  *      Palettes
4484  */
4485
4486 static void set_palette(struct vc_data *vc)
4487 {
4488         WARN_CONSOLE_UNLOCKED();
4489
4490         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4491                 vc->vc_sw->con_set_palette(vc, color_table);
4492 }
4493
4494 /*
4495  * Load palette into the DAC registers. arg points to a colour
4496  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4497  */
4498
4499 int con_set_cmap(unsigned char __user *arg)
4500 {
4501         int i, j, k;
4502         unsigned char colormap[3*16];
4503
4504         if (copy_from_user(colormap, arg, sizeof(colormap)))
4505                 return -EFAULT;
4506
4507         console_lock();
4508         for (i = k = 0; i < 16; i++) {
4509                 default_red[i] = colormap[k++];
4510                 default_grn[i] = colormap[k++];
4511                 default_blu[i] = colormap[k++];
4512         }
4513         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4514                 if (!vc_cons_allocated(i))
4515                         continue;
4516                 for (j = k = 0; j < 16; j++) {
4517                         vc_cons[i].d->vc_palette[k++] = default_red[j];
4518                         vc_cons[i].d->vc_palette[k++] = default_grn[j];
4519                         vc_cons[i].d->vc_palette[k++] = default_blu[j];
4520                 }
4521                 set_palette(vc_cons[i].d);
4522         }
4523         console_unlock();
4524
4525         return 0;
4526 }
4527
4528 int con_get_cmap(unsigned char __user *arg)
4529 {
4530         int i, k;
4531         unsigned char colormap[3*16];
4532
4533         console_lock();
4534         for (i = k = 0; i < 16; i++) {
4535                 colormap[k++] = default_red[i];
4536                 colormap[k++] = default_grn[i];
4537                 colormap[k++] = default_blu[i];
4538         }
4539         console_unlock();
4540
4541         if (copy_to_user(arg, colormap, sizeof(colormap)))
4542                 return -EFAULT;
4543
4544         return 0;
4545 }
4546
4547 void reset_palette(struct vc_data *vc)
4548 {
4549         int j, k;
4550         for (j=k=0; j<16; j++) {
4551                 vc->vc_palette[k++] = default_red[j];
4552                 vc->vc_palette[k++] = default_grn[j];
4553                 vc->vc_palette[k++] = default_blu[j];
4554         }
4555         set_palette(vc);
4556 }
4557
4558 /*
4559  *  Font switching
4560  *
4561  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4562  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4563  *  depending on width) reserved for each character which is kinda wasty, but
4564  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4565  *  is up to the actual low-level console-driver convert data into its favorite
4566  *  format (maybe we should add a `fontoffset' field to the `display'
4567  *  structure so we won't have to convert the fontdata all the time.
4568  *  /Jes
4569  */
4570
4571 #define max_font_size 65536
4572
4573 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4574 {
4575         struct console_font font;
4576         int rc = -EINVAL;
4577         int c;
4578
4579         if (op->data) {
4580                 font.data = kmalloc(max_font_size, GFP_KERNEL);
4581                 if (!font.data)
4582                         return -ENOMEM;
4583         } else
4584                 font.data = NULL;
4585
4586         console_lock();
4587         if (vc->vc_mode != KD_TEXT)
4588                 rc = -EINVAL;
4589         else if (vc->vc_sw->con_font_get)
4590                 rc = vc->vc_sw->con_font_get(vc, &font);
4591         else
4592                 rc = -ENOSYS;
4593         console_unlock();
4594
4595         if (rc)
4596                 goto out;
4597
4598         c = (font.width+7)/8 * 32 * font.charcount;
4599
4600         if (op->data && font.charcount > op->charcount)
4601                 rc = -ENOSPC;
4602         if (font.width > op->width || font.height > op->height)
4603                 rc = -ENOSPC;
4604         if (rc)
4605                 goto out;
4606
4607         op->height = font.height;
4608         op->width = font.width;
4609         op->charcount = font.charcount;
4610
4611         if (op->data && copy_to_user(op->data, font.data, c))
4612                 rc = -EFAULT;
4613
4614 out:
4615         kfree(font.data);
4616         return rc;
4617 }
4618
4619 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4620 {
4621         struct console_font font;
4622         int rc = -EINVAL;
4623         int size;
4624
4625         if (vc->vc_mode != KD_TEXT)
4626                 return -EINVAL;
4627         if (!op->data)
4628                 return -EINVAL;
4629         if (op->charcount > 512)
4630                 return -EINVAL;
4631         if (op->width <= 0 || op->width > 32 || !op->height || op->height > 32)
4632                 return -EINVAL;
4633         size = (op->width+7)/8 * 32 * op->charcount;
4634         if (size > max_font_size)
4635                 return -ENOSPC;
4636
4637         font.data = memdup_user(op->data, size);
4638         if (IS_ERR(font.data))
4639                 return PTR_ERR(font.data);
4640
4641         font.charcount = op->charcount;
4642         font.width = op->width;
4643         font.height = op->height;
4644
4645         console_lock();
4646         if (vc->vc_mode != KD_TEXT)
4647                 rc = -EINVAL;
4648         else if (vc->vc_sw->con_font_set)
4649                 rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4650         else
4651                 rc = -ENOSYS;
4652         console_unlock();
4653         kfree(font.data);
4654         return rc;
4655 }
4656
4657 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4658 {
4659         struct console_font font = {.width = op->width, .height = op->height};
4660         char name[MAX_FONT_NAME];
4661         char *s = name;
4662         int rc;
4663
4664
4665         if (!op->data)
4666                 s = NULL;
4667         else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4668                 return -EFAULT;
4669         else
4670                 name[MAX_FONT_NAME - 1] = 0;
4671
4672         console_lock();
4673         if (vc->vc_mode != KD_TEXT) {
4674                 console_unlock();
4675                 return -EINVAL;
4676         }
4677         if (vc->vc_sw->con_font_default)
4678                 rc = vc->vc_sw->con_font_default(vc, &font, s);
4679         else
4680                 rc = -ENOSYS;
4681         console_unlock();
4682         if (!rc) {
4683                 op->width = font.width;
4684                 op->height = font.height;
4685         }
4686         return rc;
4687 }
4688
4689 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4690 {
4691         switch (op->op) {
4692         case KD_FONT_OP_SET:
4693                 return con_font_set(vc, op);
4694         case KD_FONT_OP_GET:
4695                 return con_font_get(vc, op);
4696         case KD_FONT_OP_SET_DEFAULT:
4697                 return con_font_default(vc, op);
4698         case KD_FONT_OP_COPY:
4699                 /* was buggy and never really used */
4700                 return -EINVAL;
4701         }
4702         return -ENOSYS;
4703 }
4704
4705 /*
4706  *      Interface exported to selection and vcs.
4707  */
4708
4709 /* used by selection */
4710 u16 screen_glyph(const struct vc_data *vc, int offset)
4711 {
4712         u16 w = scr_readw(screenpos(vc, offset, true));
4713         u16 c = w & 0xff;
4714
4715         if (w & vc->vc_hi_font_mask)
4716                 c |= 0x100;
4717         return c;
4718 }
4719 EXPORT_SYMBOL_GPL(screen_glyph);
4720
4721 u32 screen_glyph_unicode(const struct vc_data *vc, int n)
4722 {
4723         struct uni_screen *uniscr = get_vc_uniscr(vc);
4724
4725         if (uniscr)
4726                 return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4727         return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4728 }
4729 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4730
4731 /* used by vcs - note the word offset */
4732 unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
4733 {
4734         return screenpos(vc, 2 * w_offset, viewed);
4735 }
4736 EXPORT_SYMBOL_GPL(screen_pos);
4737
4738 void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
4739 {
4740         /* clamp values if they don't fit */
4741         xy[0] = min(vc->state.x, 0xFFu);
4742         xy[1] = min(vc->state.y, 0xFFu);
4743 }
4744
4745 void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
4746 {
4747         hide_cursor(vc);
4748         gotoxy(vc, xy[0], xy[1]);
4749         set_cursor(vc);
4750 }
4751
4752 u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
4753 {
4754         if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4755                 return softcursor_original;
4756         return scr_readw(org);
4757 }
4758
4759 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4760 {
4761         scr_writew(val, org);
4762         if ((unsigned long)org == vc->vc_pos) {
4763                 softcursor_original = -1;
4764                 add_softcursor(vc);
4765         }
4766 }
4767
4768 void vcs_scr_updated(struct vc_data *vc)
4769 {
4770         notify_update(vc);
4771 }
4772
4773 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4774                 unsigned int rolled_over, void *base, unsigned int size)
4775 {
4776         unsigned long ubase = (unsigned long)base;
4777         ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4778         ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4779         ptrdiff_t origin = (void *)c->vc_origin - base;
4780         int margin = c->vc_size_row * 4;
4781         int from, wrap, from_off, avail;
4782
4783         /* Turn scrollback off */
4784         if (!lines) {
4785                 c->vc_visible_origin = c->vc_origin;
4786                 return;
4787         }
4788
4789         /* Do we have already enough to allow jumping from 0 to the end? */
4790         if (rolled_over > scr_end + margin) {
4791                 from = scr_end;
4792                 wrap = rolled_over + c->vc_size_row;
4793         } else {
4794                 from = 0;
4795                 wrap = size;
4796         }
4797
4798         from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4799         avail = (origin - from + wrap) % wrap;
4800
4801         /* Only a little piece would be left? Show all incl. the piece! */
4802         if (avail < 2 * margin)
4803                 margin = 0;
4804         if (from_off < margin)
4805                 from_off = 0;
4806         if (from_off > avail - margin)
4807                 from_off = avail;
4808
4809         c->vc_visible_origin = ubase + (from + from_off) % wrap;
4810 }
4811 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4812
4813 /*
4814  *      Visible symbols for modules
4815  */
4816
4817 EXPORT_SYMBOL(color_table);
4818 EXPORT_SYMBOL(default_red);
4819 EXPORT_SYMBOL(default_grn);
4820 EXPORT_SYMBOL(default_blu);
4821 EXPORT_SYMBOL(update_region);
4822 EXPORT_SYMBOL(redraw_screen);
4823 EXPORT_SYMBOL(vc_resize);
4824 EXPORT_SYMBOL(fg_console);
4825 EXPORT_SYMBOL(console_blank_hook);
4826 EXPORT_SYMBOL(console_blanked);
4827 EXPORT_SYMBOL(vc_cons);
4828 EXPORT_SYMBOL(global_cursor_default);
4829 #ifndef VT_SINGLE_DRIVER
4830 EXPORT_SYMBOL(give_up_console);
4831 #endif