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 };
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 /* console_lock is held */
2137 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2138 {
2139         /*
2140          *  Control characters can be used in the _middle_
2141          *  of an escape sequence.
2142          */
2143         if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
2144                 return;
2145         switch (c) {
2146         case 0:
2147                 return;
2148         case 7:
2149                 if (vc->vc_state == ESosc)
2150                         vc->vc_state = ESnormal;
2151                 else if (vc->vc_bell_duration)
2152                         kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2153                 return;
2154         case 8:
2155                 bs(vc);
2156                 return;
2157         case 9:
2158                 vc->vc_pos -= (vc->state.x << 1);
2159
2160                 vc->state.x = find_next_bit(vc->vc_tab_stop,
2161                                 min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2162                                 vc->state.x + 1);
2163                 if (vc->state.x >= VC_TABSTOPS_COUNT)
2164                         vc->state.x = vc->vc_cols - 1;
2165
2166                 vc->vc_pos += (vc->state.x << 1);
2167                 notify_write(vc, '\t');
2168                 return;
2169         case 10: case 11: case 12:
2170                 lf(vc);
2171                 if (!is_kbd(vc, lnm))
2172                         return;
2173                 fallthrough;
2174         case 13:
2175                 cr(vc);
2176                 return;
2177         case 14:
2178                 vc->state.charset = 1;
2179                 vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2180                 vc->vc_disp_ctrl = 1;
2181                 return;
2182         case 15:
2183                 vc->state.charset = 0;
2184                 vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2185                 vc->vc_disp_ctrl = 0;
2186                 return;
2187         case 24: case 26:
2188                 vc->vc_state = ESnormal;
2189                 return;
2190         case 27:
2191                 vc->vc_state = ESesc;
2192                 return;
2193         case 127:
2194                 del(vc);
2195                 return;
2196         case 128+27:
2197                 vc->vc_state = ESsquare;
2198                 return;
2199         }
2200         switch(vc->vc_state) {
2201         case ESesc:
2202                 vc->vc_state = ESnormal;
2203                 switch (c) {
2204                 case '[':
2205                         vc->vc_state = ESsquare;
2206                         return;
2207                 case ']':
2208                         vc->vc_state = ESnonstd;
2209                         return;
2210                 case '%':
2211                         vc->vc_state = ESpercent;
2212                         return;
2213                 case 'E':
2214                         cr(vc);
2215                         lf(vc);
2216                         return;
2217                 case 'M':
2218                         ri(vc);
2219                         return;
2220                 case 'D':
2221                         lf(vc);
2222                         return;
2223                 case 'H':
2224                         if (vc->state.x < VC_TABSTOPS_COUNT)
2225                                 set_bit(vc->state.x, vc->vc_tab_stop);
2226                         return;
2227                 case 'Z':
2228                         respond_ID(tty);
2229                         return;
2230                 case '7':
2231                         save_cur(vc);
2232                         return;
2233                 case '8':
2234                         restore_cur(vc);
2235                         return;
2236                 case '(':
2237                         vc->vc_state = ESsetG0;
2238                         return;
2239                 case ')':
2240                         vc->vc_state = ESsetG1;
2241                         return;
2242                 case '#':
2243                         vc->vc_state = EShash;
2244                         return;
2245                 case 'c':
2246                         reset_terminal(vc, 1);
2247                         return;
2248                 case '>':  /* Numeric keypad */
2249                         clr_kbd(vc, kbdapplic);
2250                         return;
2251                 case '=':  /* Appl. keypad */
2252                         set_kbd(vc, kbdapplic);
2253                         return;
2254                 }
2255                 return;
2256         case ESnonstd:
2257                 if (c=='P') {   /* palette escape sequence */
2258                         for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2259                                 vc->vc_par[vc->vc_npar] = 0;
2260                         vc->vc_npar = 0;
2261                         vc->vc_state = ESpalette;
2262                         return;
2263                 } else if (c=='R') {   /* reset palette */
2264                         reset_palette(vc);
2265                         vc->vc_state = ESnormal;
2266                 } else if (c>='0' && c<='9')
2267                         vc->vc_state = ESosc;
2268                 else
2269                         vc->vc_state = ESnormal;
2270                 return;
2271         case ESpalette:
2272                 if (isxdigit(c)) {
2273                         vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2274                         if (vc->vc_npar == 7) {
2275                                 int i = vc->vc_par[0] * 3, j = 1;
2276                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2277                                 vc->vc_palette[i++] += vc->vc_par[j++];
2278                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2279                                 vc->vc_palette[i++] += vc->vc_par[j++];
2280                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2281                                 vc->vc_palette[i] += vc->vc_par[j];
2282                                 set_palette(vc);
2283                                 vc->vc_state = ESnormal;
2284                         }
2285                 } else
2286                         vc->vc_state = ESnormal;
2287                 return;
2288         case ESsquare:
2289                 for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2290                         vc->vc_par[vc->vc_npar] = 0;
2291                 vc->vc_npar = 0;
2292                 vc->vc_state = ESgetpars;
2293                 if (c == '[') { /* Function key */
2294                         vc->vc_state=ESfunckey;
2295                         return;
2296                 }
2297                 switch (c) {
2298                 case '?':
2299                         vc->vc_priv = EPdec;
2300                         return;
2301                 case '>':
2302                         vc->vc_priv = EPgt;
2303                         return;
2304                 case '=':
2305                         vc->vc_priv = EPeq;
2306                         return;
2307                 case '<':
2308                         vc->vc_priv = EPlt;
2309                         return;
2310                 }
2311                 vc->vc_priv = EPecma;
2312                 fallthrough;
2313         case ESgetpars:
2314                 if (c == ';' && vc->vc_npar < NPAR - 1) {
2315                         vc->vc_npar++;
2316                         return;
2317                 } else if (c>='0' && c<='9') {
2318                         vc->vc_par[vc->vc_npar] *= 10;
2319                         vc->vc_par[vc->vc_npar] += c - '0';
2320                         return;
2321                 }
2322                 if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2323                         vc->vc_state = EScsiignore;
2324                         return;
2325                 }
2326                 vc->vc_state = ESnormal;
2327                 switch(c) {
2328                 case 'h':
2329                         if (vc->vc_priv <= EPdec)
2330                                 set_mode(vc, 1);
2331                         return;
2332                 case 'l':
2333                         if (vc->vc_priv <= EPdec)
2334                                 set_mode(vc, 0);
2335                         return;
2336                 case 'c':
2337                         if (vc->vc_priv == EPdec) {
2338                                 if (vc->vc_par[0])
2339                                         vc->vc_cursor_type =
2340                                                 CUR_MAKE(vc->vc_par[0],
2341                                                          vc->vc_par[1],
2342                                                          vc->vc_par[2]);
2343                                 else
2344                                         vc->vc_cursor_type = cur_default;
2345                                 return;
2346                         }
2347                         break;
2348                 case 'm':
2349                         if (vc->vc_priv == EPdec) {
2350                                 clear_selection();
2351                                 if (vc->vc_par[0])
2352                                         vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2353                                 else
2354                                         vc->vc_complement_mask = vc->vc_s_complement_mask;
2355                                 return;
2356                         }
2357                         break;
2358                 case 'n':
2359                         if (vc->vc_priv == EPecma) {
2360                                 if (vc->vc_par[0] == 5)
2361                                         status_report(tty);
2362                                 else if (vc->vc_par[0] == 6)
2363                                         cursor_report(vc, tty);
2364                         }
2365                         return;
2366                 }
2367                 if (vc->vc_priv != EPecma) {
2368                         vc->vc_priv = EPecma;
2369                         return;
2370                 }
2371                 switch(c) {
2372                 case 'G': case '`':
2373                         if (vc->vc_par[0])
2374                                 vc->vc_par[0]--;
2375                         gotoxy(vc, vc->vc_par[0], vc->state.y);
2376                         return;
2377                 case 'A':
2378                         if (!vc->vc_par[0])
2379                                 vc->vc_par[0]++;
2380                         gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2381                         return;
2382                 case 'B': case 'e':
2383                         if (!vc->vc_par[0])
2384                                 vc->vc_par[0]++;
2385                         gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2386                         return;
2387                 case 'C': case 'a':
2388                         if (!vc->vc_par[0])
2389                                 vc->vc_par[0]++;
2390                         gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2391                         return;
2392                 case 'D':
2393                         if (!vc->vc_par[0])
2394                                 vc->vc_par[0]++;
2395                         gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2396                         return;
2397                 case 'E':
2398                         if (!vc->vc_par[0])
2399                                 vc->vc_par[0]++;
2400                         gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2401                         return;
2402                 case 'F':
2403                         if (!vc->vc_par[0])
2404                                 vc->vc_par[0]++;
2405                         gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2406                         return;
2407                 case 'd':
2408                         if (vc->vc_par[0])
2409                                 vc->vc_par[0]--;
2410                         gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2411                         return;
2412                 case 'H': case 'f':
2413                         if (vc->vc_par[0])
2414                                 vc->vc_par[0]--;
2415                         if (vc->vc_par[1])
2416                                 vc->vc_par[1]--;
2417                         gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2418                         return;
2419                 case 'J':
2420                         csi_J(vc, vc->vc_par[0]);
2421                         return;
2422                 case 'K':
2423                         csi_K(vc, vc->vc_par[0]);
2424                         return;
2425                 case 'L':
2426                         csi_L(vc, vc->vc_par[0]);
2427                         return;
2428                 case 'M':
2429                         csi_M(vc, vc->vc_par[0]);
2430                         return;
2431                 case 'P':
2432                         csi_P(vc, vc->vc_par[0]);
2433                         return;
2434                 case 'c':
2435                         if (!vc->vc_par[0])
2436                                 respond_ID(tty);
2437                         return;
2438                 case 'g':
2439                         if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2440                                 set_bit(vc->state.x, vc->vc_tab_stop);
2441                         else if (vc->vc_par[0] == 3)
2442                                 bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2443                         return;
2444                 case 'm':
2445                         csi_m(vc);
2446                         return;
2447                 case 'q': /* DECLL - but only 3 leds */
2448                         /* map 0,1,2,3 to 0,1,2,4 */
2449                         if (vc->vc_par[0] < 4)
2450                                 vt_set_led_state(vc->vc_num,
2451                                             (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2452                         return;
2453                 case 'r':
2454                         if (!vc->vc_par[0])
2455                                 vc->vc_par[0]++;
2456                         if (!vc->vc_par[1])
2457                                 vc->vc_par[1] = vc->vc_rows;
2458                         /* Minimum allowed region is 2 lines */
2459                         if (vc->vc_par[0] < vc->vc_par[1] &&
2460                             vc->vc_par[1] <= vc->vc_rows) {
2461                                 vc->vc_top = vc->vc_par[0] - 1;
2462                                 vc->vc_bottom = vc->vc_par[1];
2463                                 gotoxay(vc, 0, 0);
2464                         }
2465                         return;
2466                 case 's':
2467                         save_cur(vc);
2468                         return;
2469                 case 'u':
2470                         restore_cur(vc);
2471                         return;
2472                 case 'X':
2473                         csi_X(vc, vc->vc_par[0]);
2474                         return;
2475                 case '@':
2476                         csi_at(vc, vc->vc_par[0]);
2477                         return;
2478                 case ']': /* setterm functions */
2479                         setterm_command(vc);
2480                         return;
2481                 }
2482                 return;
2483         case EScsiignore:
2484                 if (c >= 20 && c <= 0x3f)
2485                         return;
2486                 vc->vc_state = ESnormal;
2487                 return;
2488         case ESpercent:
2489                 vc->vc_state = ESnormal;
2490                 switch (c) {
2491                 case '@':  /* defined in ISO 2022 */
2492                         vc->vc_utf = 0;
2493                         return;
2494                 case 'G':  /* prelim official escape code */
2495                 case '8':  /* retained for compatibility */
2496                         vc->vc_utf = 1;
2497                         return;
2498                 }
2499                 return;
2500         case ESfunckey:
2501                 vc->vc_state = ESnormal;
2502                 return;
2503         case EShash:
2504                 vc->vc_state = ESnormal;
2505                 if (c == '8') {
2506                         /* DEC screen alignment test. kludge :-) */
2507                         vc->vc_video_erase_char =
2508                                 (vc->vc_video_erase_char & 0xff00) | 'E';
2509                         csi_J(vc, 2);
2510                         vc->vc_video_erase_char =
2511                                 (vc->vc_video_erase_char & 0xff00) | ' ';
2512                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2513                 }
2514                 return;
2515         case ESsetG0:
2516                 vc_setGx(vc, 0, c);
2517                 vc->vc_state = ESnormal;
2518                 return;
2519         case ESsetG1:
2520                 vc_setGx(vc, 1, c);
2521                 vc->vc_state = ESnormal;
2522                 return;
2523         case ESosc:
2524                 return;
2525         default:
2526                 vc->vc_state = ESnormal;
2527         }
2528 }
2529
2530 /* is_double_width() is based on the wcwidth() implementation by
2531  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2532  * Latest version: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2533  */
2534 struct interval {
2535         uint32_t first;
2536         uint32_t last;
2537 };
2538
2539 static int ucs_cmp(const void *key, const void *elt)
2540 {
2541         uint32_t ucs = *(uint32_t *)key;
2542         struct interval e = *(struct interval *) elt;
2543
2544         if (ucs > e.last)
2545                 return 1;
2546         else if (ucs < e.first)
2547                 return -1;
2548         return 0;
2549 }
2550
2551 static int is_double_width(uint32_t ucs)
2552 {
2553         static const struct interval double_width[] = {
2554                 { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2555                 { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2556                 { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2557                 { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2558         };
2559         if (ucs < double_width[0].first ||
2560             ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2561                 return 0;
2562
2563         return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2564                         sizeof(struct interval), ucs_cmp) != NULL;
2565 }
2566
2567 struct vc_draw_region {
2568         unsigned long from, to;
2569         int x;
2570 };
2571
2572 static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
2573 {
2574         if (draw->x < 0)
2575                 return;
2576
2577         vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
2578                         (u16 *)draw->to - (u16 *)draw->from, vc->state.y,
2579                         draw->x);
2580         draw->x = -1;
2581 }
2582
2583 static inline int vc_translate_ascii(const struct vc_data *vc, int c)
2584 {
2585         if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
2586                 if (vc->vc_toggle_meta)
2587                         c |= 0x80;
2588
2589                 return vc->vc_translate[c];
2590         }
2591
2592         return c;
2593 }
2594
2595
2596 /**
2597  * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
2598  * @c: the received character, or U+FFFD for invalid sequences.
2599  */
2600 static inline int vc_sanitize_unicode(const int c)
2601 {
2602         if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2603                 return 0xfffd;
2604
2605         return c;
2606 }
2607
2608 /**
2609  * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
2610  * @vc: virtual console
2611  * @c: character to translate
2612  * @rescan: we return true if we need more (continuation) data
2613  *
2614  * @vc_utf_char is the being-constructed unicode character.
2615  * @vc_utf_count is the number of continuation bytes still expected to arrive.
2616  * @vc_npar is the number of continuation bytes arrived so far.
2617  */
2618 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
2619 {
2620         static const u32 utf8_length_changes[] = {
2621                 0x0000007f, 0x000007ff, 0x0000ffff,
2622                 0x001fffff, 0x03ffffff, 0x7fffffff
2623         };
2624
2625         /* Continuation byte received */
2626         if ((c & 0xc0) == 0x80) {
2627                 /* Unexpected continuation byte? */
2628                 if (!vc->vc_utf_count)
2629                         return 0xfffd;
2630
2631                 vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2632                 vc->vc_npar++;
2633                 if (--vc->vc_utf_count)
2634                         goto need_more_bytes;
2635
2636                 /* Got a whole character */
2637                 c = vc->vc_utf_char;
2638                 /* Reject overlong sequences */
2639                 if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2640                                 c > utf8_length_changes[vc->vc_npar])
2641                         return 0xfffd;
2642
2643                 return vc_sanitize_unicode(c);
2644         }
2645
2646         /* Single ASCII byte or first byte of a sequence received */
2647         if (vc->vc_utf_count) {
2648                 /* Continuation byte expected */
2649                 *rescan = true;
2650                 vc->vc_utf_count = 0;
2651                 return 0xfffd;
2652         }
2653
2654         /* Nothing to do if an ASCII byte was received */
2655         if (c <= 0x7f)
2656                 return c;
2657
2658         /* First byte of a multibyte sequence received */
2659         vc->vc_npar = 0;
2660         if ((c & 0xe0) == 0xc0) {
2661                 vc->vc_utf_count = 1;
2662                 vc->vc_utf_char = (c & 0x1f);
2663         } else if ((c & 0xf0) == 0xe0) {
2664                 vc->vc_utf_count = 2;
2665                 vc->vc_utf_char = (c & 0x0f);
2666         } else if ((c & 0xf8) == 0xf0) {
2667                 vc->vc_utf_count = 3;
2668                 vc->vc_utf_char = (c & 0x07);
2669         } else if ((c & 0xfc) == 0xf8) {
2670                 vc->vc_utf_count = 4;
2671                 vc->vc_utf_char = (c & 0x03);
2672         } else if ((c & 0xfe) == 0xfc) {
2673                 vc->vc_utf_count = 5;
2674                 vc->vc_utf_char = (c & 0x01);
2675         } else {
2676                 /* 254 and 255 are invalid */
2677                 return 0xfffd;
2678         }
2679
2680 need_more_bytes:
2681         return -1;
2682 }
2683
2684 static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
2685 {
2686         /* Do no translation at all in control states */
2687         if (vc->vc_state != ESnormal)
2688                 return *c;
2689
2690         if (vc->vc_utf && !vc->vc_disp_ctrl)
2691                 return *c = vc_translate_unicode(vc, *c, rescan);
2692
2693         /* no utf or alternate charset mode */
2694         return vc_translate_ascii(vc, *c);
2695 }
2696
2697 static inline unsigned char vc_invert_attr(const struct vc_data *vc)
2698 {
2699         if (!vc->vc_can_do_color)
2700                 return vc->vc_attr ^ 0x08;
2701
2702         if (vc->vc_hi_font_mask == 0x100)
2703                 return   (vc->vc_attr & 0x11) |
2704                         ((vc->vc_attr & 0xe0) >> 4) |
2705                         ((vc->vc_attr & 0x0e) << 4);
2706
2707         return   (vc->vc_attr & 0x88) |
2708                 ((vc->vc_attr & 0x70) >> 4) |
2709                 ((vc->vc_attr & 0x07) << 4);
2710 }
2711
2712 static bool vc_is_control(struct vc_data *vc, int tc, int c)
2713 {
2714         /*
2715          * A bitmap for codes <32. A bit of 1 indicates that the code
2716          * corresponding to that bit number invokes some special action (such
2717          * as cursor movement) and should not be displayed as a glyph unless
2718          * the disp_ctrl mode is explicitly enabled.
2719          */
2720         static const u32 CTRL_ACTION = 0x0d00ff81;
2721         /* Cannot be overridden by disp_ctrl */
2722         static const u32 CTRL_ALWAYS = 0x0800f501;
2723
2724         if (vc->vc_state != ESnormal)
2725                 return true;
2726
2727         if (!tc)
2728                 return true;
2729
2730         /*
2731          * If the original code was a control character we only allow a glyph
2732          * to be displayed if the code is not normally used (such as for cursor
2733          * movement) or if the disp_ctrl mode has been explicitly enabled.
2734          * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
2735          * displayed as control characters, as the console would be pretty
2736          * useless without them; to display an arbitrary font position use the
2737          * direct-to-font zone in UTF-8 mode.
2738          */
2739         if (c < 32) {
2740                 if (vc->vc_disp_ctrl)
2741                         return CTRL_ALWAYS & BIT(c);
2742                 else
2743                         return vc->vc_utf || (CTRL_ACTION & BIT(c));
2744         }
2745
2746         if (c == 127 && !vc->vc_disp_ctrl)
2747                 return true;
2748
2749         if (c == 128 + 27)
2750                 return true;
2751
2752         return false;
2753 }
2754
2755 static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
2756                 struct vc_draw_region *draw)
2757 {
2758         int next_c;
2759         unsigned char vc_attr = vc->vc_attr;
2760         u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
2761         u8 width = 1;
2762         bool inverse = false;
2763
2764         if (vc->vc_utf && !vc->vc_disp_ctrl) {
2765                 if (is_double_width(c))
2766                         width = 2;
2767         }
2768
2769         /* Now try to find out how to display it */
2770         tc = conv_uni_to_pc(vc, tc);
2771         if (tc & ~charmask) {
2772                 if (tc == -1 || tc == -2)
2773                         return -1; /* nothing to display */
2774
2775                 /* Glyph not found */
2776                 if ((!vc->vc_utf || vc->vc_disp_ctrl || c < 128) &&
2777                                 !(c & ~charmask)) {
2778                         /*
2779                          * In legacy mode use the glyph we get by a 1:1
2780                          * mapping.
2781                          * This would make absolutely no sense with Unicode in
2782                          * mind, but do this for ASCII characters since a font
2783                          * may lack Unicode mapping info and we don't want to
2784                          * end up with having question marks only.
2785                          */
2786                         tc = c;
2787                 } else {
2788                         /*
2789                          * Display U+FFFD. If it's not found, display an inverse
2790                          * question mark.
2791                          */
2792                         tc = conv_uni_to_pc(vc, 0xfffd);
2793                         if (tc < 0) {
2794                                 inverse = true;
2795                                 tc = conv_uni_to_pc(vc, '?');
2796                                 if (tc < 0)
2797                                         tc = '?';
2798
2799                                 vc_attr = vc_invert_attr(vc);
2800                                 con_flush(vc, draw);
2801                         }
2802                 }
2803         }
2804
2805         next_c = c;
2806         while (1) {
2807                 if (vc->vc_need_wrap || vc->vc_decim)
2808                         con_flush(vc, draw);
2809                 if (vc->vc_need_wrap) {
2810                         cr(vc);
2811                         lf(vc);
2812                 }
2813                 if (vc->vc_decim)
2814                         insert_char(vc, 1);
2815                 vc_uniscr_putc(vc, next_c);
2816
2817                 if (himask)
2818                         tc = ((tc & 0x100) ? himask : 0) |
2819                               (tc &  0xff);
2820                 tc |= (vc_attr << 8) & ~himask;
2821
2822                 scr_writew(tc, (u16 *)vc->vc_pos);
2823
2824                 if (con_should_update(vc) && draw->x < 0) {
2825                         draw->x = vc->state.x;
2826                         draw->from = vc->vc_pos;
2827                 }
2828                 if (vc->state.x == vc->vc_cols - 1) {
2829                         vc->vc_need_wrap = vc->vc_decawm;
2830                         draw->to = vc->vc_pos + 2;
2831                 } else {
2832                         vc->state.x++;
2833                         draw->to = (vc->vc_pos += 2);
2834                 }
2835
2836                 if (!--width)
2837                         break;
2838
2839                 /* A space is printed in the second column */
2840                 tc = conv_uni_to_pc(vc, ' ');
2841                 if (tc < 0)
2842                         tc = ' ';
2843                 next_c = ' ';
2844         }
2845         notify_write(vc, c);
2846
2847         if (inverse)
2848                 con_flush(vc, draw);
2849
2850         return 0;
2851 }
2852
2853 /* acquires console_lock */
2854 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2855 {
2856         struct vc_draw_region draw = {
2857                 .x = -1,
2858         };
2859         int c, tc, n = 0;
2860         unsigned int currcons;
2861         struct vc_data *vc;
2862         struct vt_notifier_param param;
2863         bool rescan;
2864
2865         if (in_interrupt())
2866                 return count;
2867
2868         console_lock();
2869         vc = tty->driver_data;
2870         if (vc == NULL) {
2871                 pr_err("vt: argh, driver_data is NULL !\n");
2872                 console_unlock();
2873                 return 0;
2874         }
2875
2876         currcons = vc->vc_num;
2877         if (!vc_cons_allocated(currcons)) {
2878                 /* could this happen? */
2879                 pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2880                 console_unlock();
2881                 return 0;
2882         }
2883
2884
2885         /* undraw cursor first */
2886         if (con_is_fg(vc))
2887                 hide_cursor(vc);
2888
2889         param.vc = vc;
2890
2891         while (!tty->flow.stopped && count) {
2892                 int orig = *buf;
2893                 buf++;
2894                 n++;
2895                 count--;
2896 rescan_last_byte:
2897                 c = orig;
2898                 rescan = false;
2899
2900                 tc = vc_translate(vc, &c, &rescan);
2901                 if (tc == -1)
2902                         continue;
2903
2904                 param.c = tc;
2905                 if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2906                                         &param) == NOTIFY_STOP)
2907                         continue;
2908
2909                 if (vc_is_control(vc, tc, c)) {
2910                         con_flush(vc, &draw);
2911                         do_con_trol(tty, vc, orig);
2912                         continue;
2913                 }
2914
2915                 if (vc_con_write_normal(vc, tc, c, &draw) < 0)
2916                         continue;
2917
2918                 if (rescan)
2919                         goto rescan_last_byte;
2920         }
2921         con_flush(vc, &draw);
2922         vc_uniscr_debug_check(vc);
2923         console_conditional_schedule();
2924         notify_update(vc);
2925         console_unlock();
2926         return n;
2927 }
2928
2929 /*
2930  * This is the console switching callback.
2931  *
2932  * Doing console switching in a process context allows
2933  * us to do the switches asynchronously (needed when we want
2934  * to switch due to a keyboard interrupt).  Synchronization
2935  * with other console code and prevention of re-entrancy is
2936  * ensured with console_lock.
2937  */
2938 static void console_callback(struct work_struct *ignored)
2939 {
2940         console_lock();
2941
2942         if (want_console >= 0) {
2943                 if (want_console != fg_console &&
2944                     vc_cons_allocated(want_console)) {
2945                         hide_cursor(vc_cons[fg_console].d);
2946                         change_console(vc_cons[want_console].d);
2947                         /* we only changed when the console had already
2948                            been allocated - a new console is not created
2949                            in an interrupt routine */
2950                 }
2951                 want_console = -1;
2952         }
2953         if (do_poke_blanked_console) { /* do not unblank for a LED change */
2954                 do_poke_blanked_console = 0;
2955                 poke_blanked_console();
2956         }
2957         if (scrollback_delta) {
2958                 struct vc_data *vc = vc_cons[fg_console].d;
2959                 clear_selection();
2960                 if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2961                         vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2962                 scrollback_delta = 0;
2963         }
2964         if (blank_timer_expired) {
2965                 do_blank_screen(0);
2966                 blank_timer_expired = 0;
2967         }
2968         notify_update(vc_cons[fg_console].d);
2969
2970         console_unlock();
2971 }
2972
2973 int set_console(int nr)
2974 {
2975         struct vc_data *vc = vc_cons[fg_console].d;
2976
2977         if (!vc_cons_allocated(nr) || vt_dont_switch ||
2978                 (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2979
2980                 /*
2981                  * Console switch will fail in console_callback() or
2982                  * change_console() so there is no point scheduling
2983                  * the callback
2984                  *
2985                  * Existing set_console() users don't check the return
2986                  * value so this shouldn't break anything
2987                  */
2988                 return -EINVAL;
2989         }
2990
2991         want_console = nr;
2992         schedule_console_callback();
2993
2994         return 0;
2995 }
2996
2997 struct tty_driver *console_driver;
2998
2999 #ifdef CONFIG_VT_CONSOLE
3000
3001 /**
3002  * vt_kmsg_redirect() - Sets/gets the kernel message console
3003  * @new:        The new virtual terminal number or -1 if the console should stay
3004  *              unchanged
3005  *
3006  * By default, the kernel messages are always printed on the current virtual
3007  * console. However, the user may modify that default with the
3008  * TIOCL_SETKMSGREDIRECT ioctl call.
3009  *
3010  * This function sets the kernel message console to be @new. It returns the old
3011  * virtual console number. The virtual terminal number 0 (both as parameter and
3012  * return value) means no redirection (i.e. always printed on the currently
3013  * active console).
3014  *
3015  * The parameter -1 means that only the current console is returned, but the
3016  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
3017  * case to make the code more understandable.
3018  *
3019  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
3020  * the parameter and always returns 0.
3021  */
3022 int vt_kmsg_redirect(int new)
3023 {
3024         static int kmsg_con;
3025
3026         if (new != -1)
3027                 return xchg(&kmsg_con, new);
3028         else
3029                 return kmsg_con;
3030 }
3031
3032 /*
3033  *      Console on virtual terminal
3034  *
3035  * The console must be locked when we get here.
3036  */
3037
3038 static void vt_console_print(struct console *co, const char *b, unsigned count)
3039 {
3040         struct vc_data *vc = vc_cons[fg_console].d;
3041         unsigned char c;
3042         static DEFINE_SPINLOCK(printing_lock);
3043         const ushort *start;
3044         ushort start_x, cnt;
3045         int kmsg_console;
3046
3047         /* console busy or not yet initialized */
3048         if (!printable)
3049                 return;
3050         if (!spin_trylock(&printing_lock))
3051                 return;
3052
3053         kmsg_console = vt_get_kmsg_redirect();
3054         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
3055                 vc = vc_cons[kmsg_console - 1].d;
3056
3057         if (!vc_cons_allocated(fg_console)) {
3058                 /* impossible */
3059                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
3060                 goto quit;
3061         }
3062
3063         if (vc->vc_mode != KD_TEXT)
3064                 goto quit;
3065
3066         /* undraw cursor first */
3067         if (con_is_fg(vc))
3068                 hide_cursor(vc);
3069
3070         start = (ushort *)vc->vc_pos;
3071         start_x = vc->state.x;
3072         cnt = 0;
3073         while (count--) {
3074                 c = *b++;
3075                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
3076                         if (cnt && con_is_visible(vc))
3077                                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3078                         cnt = 0;
3079                         if (c == 8) {           /* backspace */
3080                                 bs(vc);
3081                                 start = (ushort *)vc->vc_pos;
3082                                 start_x = vc->state.x;
3083                                 continue;
3084                         }
3085                         if (c != 13)
3086                                 lf(vc);
3087                         cr(vc);
3088                         start = (ushort *)vc->vc_pos;
3089                         start_x = vc->state.x;
3090                         if (c == 10 || c == 13)
3091                                 continue;
3092                 }
3093                 vc_uniscr_putc(vc, c);
3094                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3095                 notify_write(vc, c);
3096                 cnt++;
3097                 if (vc->state.x == vc->vc_cols - 1) {
3098                         vc->vc_need_wrap = 1;
3099                 } else {
3100                         vc->vc_pos += 2;
3101                         vc->state.x++;
3102                 }
3103         }
3104         if (cnt && con_is_visible(vc))
3105                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3106         set_cursor(vc);
3107         notify_update(vc);
3108
3109 quit:
3110         spin_unlock(&printing_lock);
3111 }
3112
3113 static struct tty_driver *vt_console_device(struct console *c, int *index)
3114 {
3115         *index = c->index ? c->index-1 : fg_console;
3116         return console_driver;
3117 }
3118
3119 static struct console vt_console_driver = {
3120         .name           = "tty",
3121         .write          = vt_console_print,
3122         .device         = vt_console_device,
3123         .unblank        = unblank_screen,
3124         .flags          = CON_PRINTBUFFER,
3125         .index          = -1,
3126 };
3127 #endif
3128
3129 /*
3130  *      Handling of Linux-specific VC ioctls
3131  */
3132
3133 /*
3134  * Generally a bit racy with respect to console_lock();.
3135  *
3136  * There are some functions which don't need it.
3137  *
3138  * There are some functions which can sleep for arbitrary periods
3139  * (paste_selection) but we don't need the lock there anyway.
3140  *
3141  * set_selection_user has locking, and definitely needs it
3142  */
3143
3144 int tioclinux(struct tty_struct *tty, unsigned long arg)
3145 {
3146         char type, data;
3147         char __user *p = (char __user *)arg;
3148         int lines;
3149         int ret;
3150
3151         if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3152                 return -EPERM;
3153         if (get_user(type, p))
3154                 return -EFAULT;
3155         ret = 0;
3156
3157         switch (type)
3158         {
3159                 case TIOCL_SETSEL:
3160                         ret = set_selection_user((struct tiocl_selection
3161                                                  __user *)(p+1), tty);
3162                         break;
3163                 case TIOCL_PASTESEL:
3164                         ret = paste_selection(tty);
3165                         break;
3166                 case TIOCL_UNBLANKSCREEN:
3167                         console_lock();
3168                         unblank_screen();
3169                         console_unlock();
3170                         break;
3171                 case TIOCL_SELLOADLUT:
3172                         console_lock();
3173                         ret = sel_loadlut(p);
3174                         console_unlock();
3175                         break;
3176                 case TIOCL_GETSHIFTSTATE:
3177
3178         /*
3179          * Make it possible to react to Shift+Mousebutton.
3180          * Note that 'shift_state' is an undocumented
3181          * kernel-internal variable; programs not closely
3182          * related to the kernel should not use this.
3183          */
3184                         data = vt_get_shift_state();
3185                         ret = put_user(data, p);
3186                         break;
3187                 case TIOCL_GETMOUSEREPORTING:
3188                         console_lock(); /* May be overkill */
3189                         data = mouse_reporting();
3190                         console_unlock();
3191                         ret = put_user(data, p);
3192                         break;
3193                 case TIOCL_SETVESABLANK:
3194                         console_lock();
3195                         ret = set_vesa_blanking(p);
3196                         console_unlock();
3197                         break;
3198                 case TIOCL_GETKMSGREDIRECT:
3199                         data = vt_get_kmsg_redirect();
3200                         ret = put_user(data, p);
3201                         break;
3202                 case TIOCL_SETKMSGREDIRECT:
3203                         if (!capable(CAP_SYS_ADMIN)) {
3204                                 ret = -EPERM;
3205                         } else {
3206                                 if (get_user(data, p+1))
3207                                         ret = -EFAULT;
3208                                 else
3209                                         vt_kmsg_redirect(data);
3210                         }
3211                         break;
3212                 case TIOCL_GETFGCONSOLE:
3213                         /* No locking needed as this is a transiently
3214                            correct return anyway if the caller hasn't
3215                            disabled switching */
3216                         ret = fg_console;
3217                         break;
3218                 case TIOCL_SCROLLCONSOLE:
3219                         if (get_user(lines, (s32 __user *)(p+4))) {
3220                                 ret = -EFAULT;
3221                         } else {
3222                                 /* Need the console lock here. Note that lots
3223                                    of other calls need fixing before the lock
3224                                    is actually useful ! */
3225                                 console_lock();
3226                                 scrollfront(vc_cons[fg_console].d, lines);
3227                                 console_unlock();
3228                                 ret = 0;
3229                         }
3230                         break;
3231                 case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
3232                         console_lock();
3233                         ignore_poke = 1;
3234                         do_blank_screen(0);
3235                         console_unlock();
3236                         break;
3237                 case TIOCL_BLANKEDSCREEN:
3238                         ret = console_blanked;
3239                         break;
3240                 default:
3241                         ret = -EINVAL;
3242                         break;
3243         }
3244         return ret;
3245 }
3246
3247 /*
3248  * /dev/ttyN handling
3249  */
3250
3251 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3252 {
3253         int     retval;
3254
3255         retval = do_con_write(tty, buf, count);
3256         con_flush_chars(tty);
3257
3258         return retval;
3259 }
3260
3261 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3262 {
3263         return do_con_write(tty, &ch, 1);
3264 }
3265
3266 static unsigned int con_write_room(struct tty_struct *tty)
3267 {
3268         if (tty->flow.stopped)
3269                 return 0;
3270         return 32768;           /* No limit, really; we're not buffering */
3271 }
3272
3273 /*
3274  * con_throttle and con_unthrottle are only used for
3275  * paste_selection(), which has to stuff in a large number of
3276  * characters...
3277  */
3278 static void con_throttle(struct tty_struct *tty)
3279 {
3280 }
3281
3282 static void con_unthrottle(struct tty_struct *tty)
3283 {
3284         struct vc_data *vc = tty->driver_data;
3285
3286         wake_up_interruptible(&vc->paste_wait);
3287 }
3288
3289 /*
3290  * Turn the Scroll-Lock LED on when the tty is stopped
3291  */
3292 static void con_stop(struct tty_struct *tty)
3293 {
3294         int console_num;
3295         if (!tty)
3296                 return;
3297         console_num = tty->index;
3298         if (!vc_cons_allocated(console_num))
3299                 return;
3300         vt_kbd_con_stop(console_num);
3301 }
3302
3303 /*
3304  * Turn the Scroll-Lock LED off when the console is started
3305  */
3306 static void con_start(struct tty_struct *tty)
3307 {
3308         int console_num;
3309         if (!tty)
3310                 return;
3311         console_num = tty->index;
3312         if (!vc_cons_allocated(console_num))
3313                 return;
3314         vt_kbd_con_start(console_num);
3315 }
3316
3317 static void con_flush_chars(struct tty_struct *tty)
3318 {
3319         struct vc_data *vc;
3320
3321         if (in_interrupt())     /* from flush_to_ldisc */
3322                 return;
3323
3324         /* if we race with con_close(), vt may be null */
3325         console_lock();
3326         vc = tty->driver_data;
3327         if (vc)
3328                 set_cursor(vc);
3329         console_unlock();
3330 }
3331
3332 /*
3333  * Allocate the console screen memory.
3334  */
3335 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3336 {
3337         unsigned int currcons = tty->index;
3338         struct vc_data *vc;
3339         int ret;
3340
3341         console_lock();
3342         ret = vc_allocate(currcons);
3343         if (ret)
3344                 goto unlock;
3345
3346         vc = vc_cons[currcons].d;
3347
3348         /* Still being freed */
3349         if (vc->port.tty) {
3350                 ret = -ERESTARTSYS;
3351                 goto unlock;
3352         }
3353
3354         ret = tty_port_install(&vc->port, driver, tty);
3355         if (ret)
3356                 goto unlock;
3357
3358         tty->driver_data = vc;
3359         vc->port.tty = tty;
3360         tty_port_get(&vc->port);
3361
3362         if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3363                 tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3364                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3365         }
3366         if (vc->vc_utf)
3367                 tty->termios.c_iflag |= IUTF8;
3368         else
3369                 tty->termios.c_iflag &= ~IUTF8;
3370 unlock:
3371         console_unlock();
3372         return ret;
3373 }
3374
3375 static int con_open(struct tty_struct *tty, struct file *filp)
3376 {
3377         /* everything done in install */
3378         return 0;
3379 }
3380
3381
3382 static void con_close(struct tty_struct *tty, struct file *filp)
3383 {
3384         /* Nothing to do - we defer to shutdown */
3385 }
3386
3387 static void con_shutdown(struct tty_struct *tty)
3388 {
3389         struct vc_data *vc = tty->driver_data;
3390         BUG_ON(vc == NULL);
3391         console_lock();
3392         vc->port.tty = NULL;
3393         console_unlock();
3394 }
3395
3396 static void con_cleanup(struct tty_struct *tty)
3397 {
3398         struct vc_data *vc = tty->driver_data;
3399
3400         tty_port_put(&vc->port);
3401 }
3402
3403 static int default_color           = 7; /* white */
3404 static int default_italic_color    = 2; // green (ASCII)
3405 static int default_underline_color = 3; // cyan (ASCII)
3406 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3407 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3408 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3409
3410 static void vc_init(struct vc_data *vc, unsigned int rows,
3411                     unsigned int cols, int do_clear)
3412 {
3413         int j, k ;
3414
3415         vc->vc_cols = cols;
3416         vc->vc_rows = rows;
3417         vc->vc_size_row = cols << 1;
3418         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3419
3420         set_origin(vc);
3421         vc->vc_pos = vc->vc_origin;
3422         reset_vc(vc);
3423         for (j=k=0; j<16; j++) {
3424                 vc->vc_palette[k++] = default_red[j] ;
3425                 vc->vc_palette[k++] = default_grn[j] ;
3426                 vc->vc_palette[k++] = default_blu[j] ;
3427         }
3428         vc->vc_def_color       = default_color;
3429         vc->vc_ulcolor         = default_underline_color;
3430         vc->vc_itcolor         = default_italic_color;
3431         vc->vc_halfcolor       = 0x08;   /* grey */
3432         init_waitqueue_head(&vc->paste_wait);
3433         reset_terminal(vc, do_clear);
3434 }
3435
3436 /*
3437  * This routine initializes console interrupts, and does nothing
3438  * else. If you want the screen to clear, call tty_write with
3439  * the appropriate escape-sequence.
3440  */
3441
3442 static int __init con_init(void)
3443 {
3444         const char *display_desc = NULL;
3445         struct vc_data *vc;
3446         unsigned int currcons = 0, i;
3447
3448         console_lock();
3449
3450         if (!conswitchp)
3451                 conswitchp = &dummy_con;
3452         display_desc = conswitchp->con_startup();
3453         if (!display_desc) {
3454                 fg_console = 0;
3455                 console_unlock();
3456                 return 0;
3457         }
3458
3459         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3460                 struct con_driver *con_driver = &registered_con_driver[i];
3461
3462                 if (con_driver->con == NULL) {
3463                         con_driver->con = conswitchp;
3464                         con_driver->desc = display_desc;
3465                         con_driver->flag = CON_DRIVER_FLAG_INIT;
3466                         con_driver->first = 0;
3467                         con_driver->last = MAX_NR_CONSOLES - 1;
3468                         break;
3469                 }
3470         }
3471
3472         for (i = 0; i < MAX_NR_CONSOLES; i++)
3473                 con_driver_map[i] = conswitchp;
3474
3475         if (blankinterval) {
3476                 blank_state = blank_normal_wait;
3477                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3478         }
3479
3480         for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3481                 vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3482                 INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3483                 tty_port_init(&vc->port);
3484                 visual_init(vc, currcons, 1);
3485                 /* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3486                 vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3487                 vc_init(vc, vc->vc_rows, vc->vc_cols,
3488                         currcons || !vc->vc_sw->con_save_screen);
3489         }
3490         currcons = fg_console = 0;
3491         master_display_fg = vc = vc_cons[currcons].d;
3492         set_origin(vc);
3493         save_screen(vc);
3494         gotoxy(vc, vc->state.x, vc->state.y);
3495         csi_J(vc, 0);
3496         update_screen(vc);
3497         pr_info("Console: %s %s %dx%d\n",
3498                 vc->vc_can_do_color ? "colour" : "mono",
3499                 display_desc, vc->vc_cols, vc->vc_rows);
3500         printable = 1;
3501
3502         console_unlock();
3503
3504 #ifdef CONFIG_VT_CONSOLE
3505         register_console(&vt_console_driver);
3506 #endif
3507         return 0;
3508 }
3509 console_initcall(con_init);
3510
3511 static const struct tty_operations con_ops = {
3512         .install = con_install,
3513         .open = con_open,
3514         .close = con_close,
3515         .write = con_write,
3516         .write_room = con_write_room,
3517         .put_char = con_put_char,
3518         .flush_chars = con_flush_chars,
3519         .ioctl = vt_ioctl,
3520 #ifdef CONFIG_COMPAT
3521         .compat_ioctl = vt_compat_ioctl,
3522 #endif
3523         .stop = con_stop,
3524         .start = con_start,
3525         .throttle = con_throttle,
3526         .unthrottle = con_unthrottle,
3527         .resize = vt_resize,
3528         .shutdown = con_shutdown,
3529         .cleanup = con_cleanup,
3530 };
3531
3532 static struct cdev vc0_cdev;
3533
3534 static ssize_t show_tty_active(struct device *dev,
3535                                 struct device_attribute *attr, char *buf)
3536 {
3537         return sprintf(buf, "tty%d\n", fg_console + 1);
3538 }
3539 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3540
3541 static struct attribute *vt_dev_attrs[] = {
3542         &dev_attr_active.attr,
3543         NULL
3544 };
3545
3546 ATTRIBUTE_GROUPS(vt_dev);
3547
3548 int __init vty_init(const struct file_operations *console_fops)
3549 {
3550         cdev_init(&vc0_cdev, console_fops);
3551         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3552             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3553                 panic("Couldn't register /dev/tty0 driver\n");
3554         tty0dev = device_create_with_groups(tty_class, NULL,
3555                                             MKDEV(TTY_MAJOR, 0), NULL,
3556                                             vt_dev_groups, "tty0");
3557         if (IS_ERR(tty0dev))
3558                 tty0dev = NULL;
3559
3560         vcs_init();
3561
3562         console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3563         if (!console_driver)
3564                 panic("Couldn't allocate console driver\n");
3565
3566         console_driver->name = "tty";
3567         console_driver->name_base = 1;
3568         console_driver->major = TTY_MAJOR;
3569         console_driver->minor_start = 1;
3570         console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3571         console_driver->init_termios = tty_std_termios;
3572         if (default_utf8)
3573                 console_driver->init_termios.c_iflag |= IUTF8;
3574         console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3575         tty_set_operations(console_driver, &con_ops);
3576         if (tty_register_driver(console_driver))
3577                 panic("Couldn't register console driver\n");
3578         kbd_init();
3579         console_map_init();
3580 #ifdef CONFIG_MDA_CONSOLE
3581         mda_console_init();
3582 #endif
3583         return 0;
3584 }
3585
3586 #ifndef VT_SINGLE_DRIVER
3587
3588 static struct class *vtconsole_class;
3589
3590 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3591                            int deflt)
3592 {
3593         struct module *owner = csw->owner;
3594         const char *desc = NULL;
3595         struct con_driver *con_driver;
3596         int i, j = -1, k = -1, retval = -ENODEV;
3597
3598         if (!try_module_get(owner))
3599                 return -ENODEV;
3600
3601         WARN_CONSOLE_UNLOCKED();
3602
3603         /* check if driver is registered */
3604         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3605                 con_driver = &registered_con_driver[i];
3606
3607                 if (con_driver->con == csw) {
3608                         desc = con_driver->desc;
3609                         retval = 0;
3610                         break;
3611                 }
3612         }
3613
3614         if (retval)
3615                 goto err;
3616
3617         if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3618                 csw->con_startup();
3619                 con_driver->flag |= CON_DRIVER_FLAG_INIT;
3620         }
3621
3622         if (deflt) {
3623                 if (conswitchp)
3624                         module_put(conswitchp->owner);
3625
3626                 __module_get(owner);
3627                 conswitchp = csw;
3628         }
3629
3630         first = max(first, con_driver->first);
3631         last = min(last, con_driver->last);
3632
3633         for (i = first; i <= last; i++) {
3634                 int old_was_color;
3635                 struct vc_data *vc = vc_cons[i].d;
3636
3637                 if (con_driver_map[i])
3638                         module_put(con_driver_map[i]->owner);
3639                 __module_get(owner);
3640                 con_driver_map[i] = csw;
3641
3642                 if (!vc || !vc->vc_sw)
3643                         continue;
3644
3645                 j = i;
3646
3647                 if (con_is_visible(vc)) {
3648                         k = i;
3649                         save_screen(vc);
3650                 }
3651
3652                 old_was_color = vc->vc_can_do_color;
3653                 vc->vc_sw->con_deinit(vc);
3654                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3655                 visual_init(vc, i, 0);
3656                 set_origin(vc);
3657                 update_attr(vc);
3658
3659                 /* If the console changed between mono <-> color, then
3660                  * the attributes in the screenbuf will be wrong.  The
3661                  * following resets all attributes to something sane.
3662                  */
3663                 if (old_was_color != vc->vc_can_do_color)
3664                         clear_buffer_attributes(vc);
3665         }
3666
3667         pr_info("Console: switching ");
3668         if (!deflt)
3669                 pr_cont("consoles %d-%d ", first + 1, last + 1);
3670         if (j >= 0) {
3671                 struct vc_data *vc = vc_cons[j].d;
3672
3673                 pr_cont("to %s %s %dx%d\n",
3674                         vc->vc_can_do_color ? "colour" : "mono",
3675                         desc, vc->vc_cols, vc->vc_rows);
3676
3677                 if (k >= 0) {
3678                         vc = vc_cons[k].d;
3679                         update_screen(vc);
3680                 }
3681         } else {
3682                 pr_cont("to %s\n", desc);
3683         }
3684
3685         retval = 0;
3686 err:
3687         module_put(owner);
3688         return retval;
3689 };
3690
3691
3692 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3693 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3694 {
3695         struct module *owner = csw->owner;
3696         const struct consw *defcsw = NULL;
3697         struct con_driver *con_driver = NULL, *con_back = NULL;
3698         int i, retval = -ENODEV;
3699
3700         if (!try_module_get(owner))
3701                 return -ENODEV;
3702
3703         WARN_CONSOLE_UNLOCKED();
3704
3705         /* check if driver is registered and if it is unbindable */
3706         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3707                 con_driver = &registered_con_driver[i];
3708
3709                 if (con_driver->con == csw &&
3710                     con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3711                         retval = 0;
3712                         break;
3713                 }
3714         }
3715
3716         if (retval)
3717                 goto err;
3718
3719         retval = -ENODEV;
3720
3721         /* check if backup driver exists */
3722         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3723                 con_back = &registered_con_driver[i];
3724
3725                 if (con_back->con && con_back->con != csw) {
3726                         defcsw = con_back->con;
3727                         retval = 0;
3728                         break;
3729                 }
3730         }
3731
3732         if (retval)
3733                 goto err;
3734
3735         if (!con_is_bound(csw))
3736                 goto err;
3737
3738         first = max(first, con_driver->first);
3739         last = min(last, con_driver->last);
3740
3741         for (i = first; i <= last; i++) {
3742                 if (con_driver_map[i] == csw) {
3743                         module_put(csw->owner);
3744                         con_driver_map[i] = NULL;
3745                 }
3746         }
3747
3748         if (!con_is_bound(defcsw)) {
3749                 const struct consw *defconsw = conswitchp;
3750
3751                 defcsw->con_startup();
3752                 con_back->flag |= CON_DRIVER_FLAG_INIT;
3753                 /*
3754                  * vgacon may change the default driver to point
3755                  * to dummycon, we restore it here...
3756                  */
3757                 conswitchp = defconsw;
3758         }
3759
3760         if (!con_is_bound(csw))
3761                 con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3762
3763         /* ignore return value, binding should not fail */
3764         do_bind_con_driver(defcsw, first, last, deflt);
3765 err:
3766         module_put(owner);
3767         return retval;
3768
3769 }
3770 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3771
3772 static int vt_bind(struct con_driver *con)
3773 {
3774         const struct consw *defcsw = NULL, *csw = NULL;
3775         int i, more = 1, first = -1, last = -1, deflt = 0;
3776
3777         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3778                 goto err;
3779
3780         csw = con->con;
3781
3782         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3783                 struct con_driver *con = &registered_con_driver[i];
3784
3785                 if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3786                         defcsw = con->con;
3787                         break;
3788                 }
3789         }
3790
3791         if (!defcsw)
3792                 goto err;
3793
3794         while (more) {
3795                 more = 0;
3796
3797                 for (i = con->first; i <= con->last; i++) {
3798                         if (con_driver_map[i] == defcsw) {
3799                                 if (first == -1)
3800                                         first = i;
3801                                 last = i;
3802                                 more = 1;
3803                         } else if (first != -1)
3804                                 break;
3805                 }
3806
3807                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3808                         deflt = 1;
3809
3810                 if (first != -1)
3811                         do_bind_con_driver(csw, first, last, deflt);
3812
3813                 first = -1;
3814                 last = -1;
3815                 deflt = 0;
3816         }
3817
3818 err:
3819         return 0;
3820 }
3821
3822 static int vt_unbind(struct con_driver *con)
3823 {
3824         const struct consw *csw = NULL;
3825         int i, more = 1, first = -1, last = -1, deflt = 0;
3826         int ret;
3827
3828         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3829                 goto err;
3830
3831         csw = con->con;
3832
3833         while (more) {
3834                 more = 0;
3835
3836                 for (i = con->first; i <= con->last; i++) {
3837                         if (con_driver_map[i] == csw) {
3838                                 if (first == -1)
3839                                         first = i;
3840                                 last = i;
3841                                 more = 1;
3842                         } else if (first != -1)
3843                                 break;
3844                 }
3845
3846                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3847                         deflt = 1;
3848
3849                 if (first != -1) {
3850                         ret = do_unbind_con_driver(csw, first, last, deflt);
3851                         if (ret != 0)
3852                                 return ret;
3853                 }
3854
3855                 first = -1;
3856                 last = -1;
3857                 deflt = 0;
3858         }
3859
3860 err:
3861         return 0;
3862 }
3863 #else
3864 static inline int vt_bind(struct con_driver *con)
3865 {
3866         return 0;
3867 }
3868 static inline int vt_unbind(struct con_driver *con)
3869 {
3870         return 0;
3871 }
3872 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3873
3874 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3875                           const char *buf, size_t count)
3876 {
3877         struct con_driver *con = dev_get_drvdata(dev);
3878         int bind = simple_strtoul(buf, NULL, 0);
3879
3880         console_lock();
3881
3882         if (bind)
3883                 vt_bind(con);
3884         else
3885                 vt_unbind(con);
3886
3887         console_unlock();
3888
3889         return count;
3890 }
3891
3892 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3893                          char *buf)
3894 {
3895         struct con_driver *con = dev_get_drvdata(dev);
3896         int bind;
3897
3898         console_lock();
3899         bind = con_is_bound(con->con);
3900         console_unlock();
3901
3902         return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3903 }
3904
3905 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3906                          char *buf)
3907 {
3908         struct con_driver *con = dev_get_drvdata(dev);
3909
3910         return snprintf(buf, PAGE_SIZE, "%s %s\n",
3911                         (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3912                          con->desc);
3913
3914 }
3915
3916 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3917 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3918
3919 static struct attribute *con_dev_attrs[] = {
3920         &dev_attr_bind.attr,
3921         &dev_attr_name.attr,
3922         NULL
3923 };
3924
3925 ATTRIBUTE_GROUPS(con_dev);
3926
3927 static int vtconsole_init_device(struct con_driver *con)
3928 {
3929         con->flag |= CON_DRIVER_FLAG_ATTR;
3930         return 0;
3931 }
3932
3933 static void vtconsole_deinit_device(struct con_driver *con)
3934 {
3935         con->flag &= ~CON_DRIVER_FLAG_ATTR;
3936 }
3937
3938 /**
3939  * con_is_bound - checks if driver is bound to the console
3940  * @csw: console driver
3941  *
3942  * RETURNS: zero if unbound, nonzero if bound
3943  *
3944  * Drivers can call this and if zero, they should release
3945  * all resources allocated on con_startup()
3946  */
3947 int con_is_bound(const struct consw *csw)
3948 {
3949         int i, bound = 0;
3950
3951         WARN_CONSOLE_UNLOCKED();
3952
3953         for (i = 0; i < MAX_NR_CONSOLES; i++) {
3954                 if (con_driver_map[i] == csw) {
3955                         bound = 1;
3956                         break;
3957                 }
3958         }
3959
3960         return bound;
3961 }
3962 EXPORT_SYMBOL(con_is_bound);
3963
3964 /**
3965  * con_is_visible - checks whether the current console is visible
3966  * @vc: virtual console
3967  *
3968  * RETURNS: zero if not visible, nonzero if visible
3969  */
3970 bool con_is_visible(const struct vc_data *vc)
3971 {
3972         WARN_CONSOLE_UNLOCKED();
3973
3974         return *vc->vc_display_fg == vc;
3975 }
3976 EXPORT_SYMBOL(con_is_visible);
3977
3978 /**
3979  * con_debug_enter - prepare the console for the kernel debugger
3980  * @vc: virtual console
3981  *
3982  * Called when the console is taken over by the kernel debugger, this
3983  * function needs to save the current console state, then put the console
3984  * into a state suitable for the kernel debugger.
3985  *
3986  * RETURNS:
3987  * Zero on success, nonzero if a failure occurred when trying to prepare
3988  * the console for the debugger.
3989  */
3990 int con_debug_enter(struct vc_data *vc)
3991 {
3992         int ret = 0;
3993
3994         saved_fg_console = fg_console;
3995         saved_last_console = last_console;
3996         saved_want_console = want_console;
3997         saved_vc_mode = vc->vc_mode;
3998         saved_console_blanked = console_blanked;
3999         vc->vc_mode = KD_TEXT;
4000         console_blanked = 0;
4001         if (vc->vc_sw->con_debug_enter)
4002                 ret = vc->vc_sw->con_debug_enter(vc);
4003 #ifdef CONFIG_KGDB_KDB
4004         /* Set the initial LINES variable if it is not already set */
4005         if (vc->vc_rows < 999) {
4006                 int linecount;
4007                 char lns[4];
4008                 const char *setargs[3] = {
4009                         "set",
4010                         "LINES",
4011                         lns,
4012                 };
4013                 if (kdbgetintenv(setargs[0], &linecount)) {
4014                         snprintf(lns, 4, "%i", vc->vc_rows);
4015                         kdb_set(2, setargs);
4016                 }
4017         }
4018         if (vc->vc_cols < 999) {
4019                 int colcount;
4020                 char cols[4];
4021                 const char *setargs[3] = {
4022                         "set",
4023                         "COLUMNS",
4024                         cols,
4025                 };
4026                 if (kdbgetintenv(setargs[0], &colcount)) {
4027                         snprintf(cols, 4, "%i", vc->vc_cols);
4028                         kdb_set(2, setargs);
4029                 }
4030         }
4031 #endif /* CONFIG_KGDB_KDB */
4032         return ret;
4033 }
4034 EXPORT_SYMBOL_GPL(con_debug_enter);
4035
4036 /**
4037  * con_debug_leave - restore console state
4038  *
4039  * Restore the console state to what it was before the kernel debugger
4040  * was invoked.
4041  *
4042  * RETURNS:
4043  * Zero on success, nonzero if a failure occurred when trying to restore
4044  * the console.
4045  */
4046 int con_debug_leave(void)
4047 {
4048         struct vc_data *vc;
4049         int ret = 0;
4050
4051         fg_console = saved_fg_console;
4052         last_console = saved_last_console;
4053         want_console = saved_want_console;
4054         console_blanked = saved_console_blanked;
4055         vc_cons[fg_console].d->vc_mode = saved_vc_mode;
4056
4057         vc = vc_cons[fg_console].d;
4058         if (vc->vc_sw->con_debug_leave)
4059                 ret = vc->vc_sw->con_debug_leave(vc);
4060         return ret;
4061 }
4062 EXPORT_SYMBOL_GPL(con_debug_leave);
4063
4064 static int do_register_con_driver(const struct consw *csw, int first, int last)
4065 {
4066         struct module *owner = csw->owner;
4067         struct con_driver *con_driver;
4068         const char *desc;
4069         int i, retval;
4070
4071         WARN_CONSOLE_UNLOCKED();
4072
4073         if (!try_module_get(owner))
4074                 return -ENODEV;
4075
4076         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4077                 con_driver = &registered_con_driver[i];
4078
4079                 /* already registered */
4080                 if (con_driver->con == csw) {
4081                         retval = -EBUSY;
4082                         goto err;
4083                 }
4084         }
4085
4086         desc = csw->con_startup();
4087         if (!desc) {
4088                 retval = -ENODEV;
4089                 goto err;
4090         }
4091
4092         retval = -EINVAL;
4093
4094         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4095                 con_driver = &registered_con_driver[i];
4096
4097                 if (con_driver->con == NULL &&
4098                     !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
4099                         con_driver->con = csw;
4100                         con_driver->desc = desc;
4101                         con_driver->node = i;
4102                         con_driver->flag = CON_DRIVER_FLAG_MODULE |
4103                                            CON_DRIVER_FLAG_INIT;
4104                         con_driver->first = first;
4105                         con_driver->last = last;
4106                         retval = 0;
4107                         break;
4108                 }
4109         }
4110
4111         if (retval)
4112                 goto err;
4113
4114         con_driver->dev =
4115                 device_create_with_groups(vtconsole_class, NULL,
4116                                           MKDEV(0, con_driver->node),
4117                                           con_driver, con_dev_groups,
4118                                           "vtcon%i", con_driver->node);
4119         if (IS_ERR(con_driver->dev)) {
4120                 pr_warn("Unable to create device for %s; errno = %ld\n",
4121                         con_driver->desc, PTR_ERR(con_driver->dev));
4122                 con_driver->dev = NULL;
4123         } else {
4124                 vtconsole_init_device(con_driver);
4125         }
4126
4127 err:
4128         module_put(owner);
4129         return retval;
4130 }
4131
4132
4133 /**
4134  * do_unregister_con_driver - unregister console driver from console layer
4135  * @csw: console driver
4136  *
4137  * DESCRIPTION: All drivers that registers to the console layer must
4138  * call this function upon exit, or if the console driver is in a state
4139  * where it won't be able to handle console services, such as the
4140  * framebuffer console without loaded framebuffer drivers.
4141  *
4142  * The driver must unbind first prior to unregistration.
4143  */
4144 int do_unregister_con_driver(const struct consw *csw)
4145 {
4146         int i;
4147
4148         /* cannot unregister a bound driver */
4149         if (con_is_bound(csw))
4150                 return -EBUSY;
4151
4152         if (csw == conswitchp)
4153                 return -EINVAL;
4154
4155         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4156                 struct con_driver *con_driver = &registered_con_driver[i];
4157
4158                 if (con_driver->con == csw) {
4159                         /*
4160                          * Defer the removal of the sysfs entries since that
4161                          * will acquire the kernfs s_active lock and we can't
4162                          * acquire this lock while holding the console lock:
4163                          * the unbind sysfs entry imposes already the opposite
4164                          * order. Reset con already here to prevent any later
4165                          * lookup to succeed and mark this slot as zombie, so
4166                          * it won't get reused until we complete the removal
4167                          * in the deferred work.
4168                          */
4169                         con_driver->con = NULL;
4170                         con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4171                         schedule_work(&con_driver_unregister_work);
4172
4173                         return 0;
4174                 }
4175         }
4176
4177         return -ENODEV;
4178 }
4179 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4180
4181 static void con_driver_unregister_callback(struct work_struct *ignored)
4182 {
4183         int i;
4184
4185         console_lock();
4186
4187         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4188                 struct con_driver *con_driver = &registered_con_driver[i];
4189
4190                 if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4191                         continue;
4192
4193                 console_unlock();
4194
4195                 vtconsole_deinit_device(con_driver);
4196                 device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4197
4198                 console_lock();
4199
4200                 if (WARN_ON_ONCE(con_driver->con))
4201                         con_driver->con = NULL;
4202                 con_driver->desc = NULL;
4203                 con_driver->dev = NULL;
4204                 con_driver->node = 0;
4205                 WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4206                 con_driver->flag = 0;
4207                 con_driver->first = 0;
4208                 con_driver->last = 0;
4209         }
4210
4211         console_unlock();
4212 }
4213
4214 /*
4215  *      If we support more console drivers, this function is used
4216  *      when a driver wants to take over some existing consoles
4217  *      and become default driver for newly opened ones.
4218  *
4219  *      do_take_over_console is basically a register followed by bind
4220  */
4221 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4222 {
4223         int err;
4224
4225         err = do_register_con_driver(csw, first, last);
4226         /*
4227          * If we get an busy error we still want to bind the console driver
4228          * and return success, as we may have unbound the console driver
4229          * but not unregistered it.
4230          */
4231         if (err == -EBUSY)
4232                 err = 0;
4233         if (!err)
4234                 do_bind_con_driver(csw, first, last, deflt);
4235
4236         return err;
4237 }
4238 EXPORT_SYMBOL_GPL(do_take_over_console);
4239
4240
4241 /*
4242  * give_up_console is a wrapper to unregister_con_driver. It will only
4243  * work if driver is fully unbound.
4244  */
4245 void give_up_console(const struct consw *csw)
4246 {
4247         console_lock();
4248         do_unregister_con_driver(csw);
4249         console_unlock();
4250 }
4251
4252 static int __init vtconsole_class_init(void)
4253 {
4254         int i;
4255
4256         vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4257         if (IS_ERR(vtconsole_class)) {
4258                 pr_warn("Unable to create vt console class; errno = %ld\n",
4259                         PTR_ERR(vtconsole_class));
4260                 vtconsole_class = NULL;
4261         }
4262
4263         /* Add system drivers to sysfs */
4264         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4265                 struct con_driver *con = &registered_con_driver[i];
4266
4267                 if (con->con && !con->dev) {
4268                         con->dev =
4269                                 device_create_with_groups(vtconsole_class, NULL,
4270                                                           MKDEV(0, con->node),
4271                                                           con, con_dev_groups,
4272                                                           "vtcon%i", con->node);
4273
4274                         if (IS_ERR(con->dev)) {
4275                                 pr_warn("Unable to create device for %s; errno = %ld\n",
4276                                         con->desc, PTR_ERR(con->dev));
4277                                 con->dev = NULL;
4278                         } else {
4279                                 vtconsole_init_device(con);
4280                         }
4281                 }
4282         }
4283
4284         return 0;
4285 }
4286 postcore_initcall(vtconsole_class_init);
4287
4288 #endif
4289
4290 /*
4291  *      Screen blanking
4292  */
4293
4294 static int set_vesa_blanking(char __user *p)
4295 {
4296         unsigned int mode;
4297
4298         if (get_user(mode, p + 1))
4299                 return -EFAULT;
4300
4301         vesa_blank_mode = (mode < 4) ? mode : 0;
4302         return 0;
4303 }
4304
4305 void do_blank_screen(int entering_gfx)
4306 {
4307         struct vc_data *vc = vc_cons[fg_console].d;
4308         int i;
4309
4310         might_sleep();
4311
4312         WARN_CONSOLE_UNLOCKED();
4313
4314         if (console_blanked) {
4315                 if (blank_state == blank_vesa_wait) {
4316                         blank_state = blank_off;
4317                         vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4318                 }
4319                 return;
4320         }
4321
4322         /* entering graphics mode? */
4323         if (entering_gfx) {
4324                 hide_cursor(vc);
4325                 save_screen(vc);
4326                 vc->vc_sw->con_blank(vc, -1, 1);
4327                 console_blanked = fg_console + 1;
4328                 blank_state = blank_off;
4329                 set_origin(vc);
4330                 return;
4331         }
4332
4333         blank_state = blank_off;
4334
4335         /* don't blank graphics */
4336         if (vc->vc_mode != KD_TEXT) {
4337                 console_blanked = fg_console + 1;
4338                 return;
4339         }
4340
4341         hide_cursor(vc);
4342         del_timer_sync(&console_timer);
4343         blank_timer_expired = 0;
4344
4345         save_screen(vc);
4346         /* In case we need to reset origin, blanking hook returns 1 */
4347         i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4348         console_blanked = fg_console + 1;
4349         if (i)
4350                 set_origin(vc);
4351
4352         if (console_blank_hook && console_blank_hook(1))
4353                 return;
4354
4355         if (vesa_off_interval && vesa_blank_mode) {
4356                 blank_state = blank_vesa_wait;
4357                 mod_timer(&console_timer, jiffies + vesa_off_interval);
4358         }
4359         vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4360 }
4361 EXPORT_SYMBOL(do_blank_screen);
4362
4363 /*
4364  * Called by timer as well as from vt_console_driver
4365  */
4366 void do_unblank_screen(int leaving_gfx)
4367 {
4368         struct vc_data *vc;
4369
4370         /* This should now always be called from a "sane" (read: can schedule)
4371          * context for the sake of the low level drivers, except in the special
4372          * case of oops_in_progress
4373          */
4374         if (!oops_in_progress)
4375                 might_sleep();
4376
4377         WARN_CONSOLE_UNLOCKED();
4378
4379         ignore_poke = 0;
4380         if (!console_blanked)
4381                 return;
4382         if (!vc_cons_allocated(fg_console)) {
4383                 /* impossible */
4384                 pr_warn("unblank_screen: tty %d not allocated ??\n",
4385                         fg_console + 1);
4386                 return;
4387         }
4388         vc = vc_cons[fg_console].d;
4389         if (vc->vc_mode != KD_TEXT)
4390                 return; /* but leave console_blanked != 0 */
4391
4392         if (blankinterval) {
4393                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4394                 blank_state = blank_normal_wait;
4395         }
4396
4397         console_blanked = 0;
4398         if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4399                 /* Low-level driver cannot restore -> do it ourselves */
4400                 update_screen(vc);
4401         if (console_blank_hook)
4402                 console_blank_hook(0);
4403         set_palette(vc);
4404         set_cursor(vc);
4405         vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4406 }
4407 EXPORT_SYMBOL(do_unblank_screen);
4408
4409 /*
4410  * This is called by the outside world to cause a forced unblank, mostly for
4411  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4412  * call it with 1 as an argument and so force a mode restore... that may kill
4413  * X or at least garbage the screen but would also make the Oops visible...
4414  */
4415 void unblank_screen(void)
4416 {
4417         do_unblank_screen(0);
4418 }
4419
4420 /*
4421  * We defer the timer blanking to work queue so it can take the console mutex
4422  * (console operations can still happen at irq time, but only from printk which
4423  * has the console mutex. Not perfect yet, but better than no locking
4424  */
4425 static void blank_screen_t(struct timer_list *unused)
4426 {
4427         blank_timer_expired = 1;
4428         schedule_work(&console_work);
4429 }
4430
4431 void poke_blanked_console(void)
4432 {
4433         WARN_CONSOLE_UNLOCKED();
4434
4435         /* Add this so we quickly catch whoever might call us in a non
4436          * safe context. Nowadays, unblank_screen() isn't to be called in
4437          * atomic contexts and is allowed to schedule (with the special case
4438          * of oops_in_progress, but that isn't of any concern for this
4439          * function. --BenH.
4440          */
4441         might_sleep();
4442
4443         /* This isn't perfectly race free, but a race here would be mostly harmless,
4444          * at worst, we'll do a spurious blank and it's unlikely
4445          */
4446         del_timer(&console_timer);
4447         blank_timer_expired = 0;
4448
4449         if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4450                 return;
4451         if (console_blanked)
4452                 unblank_screen();
4453         else if (blankinterval) {
4454                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4455                 blank_state = blank_normal_wait;
4456         }
4457 }
4458
4459 /*
4460  *      Palettes
4461  */
4462
4463 static void set_palette(struct vc_data *vc)
4464 {
4465         WARN_CONSOLE_UNLOCKED();
4466
4467         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4468                 vc->vc_sw->con_set_palette(vc, color_table);
4469 }
4470
4471 /*
4472  * Load palette into the DAC registers. arg points to a colour
4473  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4474  */
4475
4476 int con_set_cmap(unsigned char __user *arg)
4477 {
4478         int i, j, k;
4479         unsigned char colormap[3*16];
4480
4481         if (copy_from_user(colormap, arg, sizeof(colormap)))
4482                 return -EFAULT;
4483
4484         console_lock();
4485         for (i = k = 0; i < 16; i++) {
4486                 default_red[i] = colormap[k++];
4487                 default_grn[i] = colormap[k++];
4488                 default_blu[i] = colormap[k++];
4489         }
4490         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4491                 if (!vc_cons_allocated(i))
4492                         continue;
4493                 for (j = k = 0; j < 16; j++) {
4494                         vc_cons[i].d->vc_palette[k++] = default_red[j];
4495                         vc_cons[i].d->vc_palette[k++] = default_grn[j];
4496                         vc_cons[i].d->vc_palette[k++] = default_blu[j];
4497                 }
4498                 set_palette(vc_cons[i].d);
4499         }
4500         console_unlock();
4501
4502         return 0;
4503 }
4504
4505 int con_get_cmap(unsigned char __user *arg)
4506 {
4507         int i, k;
4508         unsigned char colormap[3*16];
4509
4510         console_lock();
4511         for (i = k = 0; i < 16; i++) {
4512                 colormap[k++] = default_red[i];
4513                 colormap[k++] = default_grn[i];
4514                 colormap[k++] = default_blu[i];
4515         }
4516         console_unlock();
4517
4518         if (copy_to_user(arg, colormap, sizeof(colormap)))
4519                 return -EFAULT;
4520
4521         return 0;
4522 }
4523
4524 void reset_palette(struct vc_data *vc)
4525 {
4526         int j, k;
4527         for (j=k=0; j<16; j++) {
4528                 vc->vc_palette[k++] = default_red[j];
4529                 vc->vc_palette[k++] = default_grn[j];
4530                 vc->vc_palette[k++] = default_blu[j];
4531         }
4532         set_palette(vc);
4533 }
4534
4535 /*
4536  *  Font switching
4537  *
4538  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4539  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4540  *  depending on width) reserved for each character which is kinda wasty, but
4541  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4542  *  is up to the actual low-level console-driver convert data into its favorite
4543  *  format (maybe we should add a `fontoffset' field to the `display'
4544  *  structure so we won't have to convert the fontdata all the time.
4545  *  /Jes
4546  */
4547
4548 #define max_font_size 65536
4549
4550 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4551 {
4552         struct console_font font;
4553         int rc = -EINVAL;
4554         int c;
4555
4556         if (op->data) {
4557                 font.data = kmalloc(max_font_size, GFP_KERNEL);
4558                 if (!font.data)
4559                         return -ENOMEM;
4560         } else
4561                 font.data = NULL;
4562
4563         console_lock();
4564         if (vc->vc_mode != KD_TEXT)
4565                 rc = -EINVAL;
4566         else if (vc->vc_sw->con_font_get)
4567                 rc = vc->vc_sw->con_font_get(vc, &font);
4568         else
4569                 rc = -ENOSYS;
4570         console_unlock();
4571
4572         if (rc)
4573                 goto out;
4574
4575         c = (font.width+7)/8 * 32 * font.charcount;
4576
4577         if (op->data && font.charcount > op->charcount)
4578                 rc = -ENOSPC;
4579         if (font.width > op->width || font.height > op->height)
4580                 rc = -ENOSPC;
4581         if (rc)
4582                 goto out;
4583
4584         op->height = font.height;
4585         op->width = font.width;
4586         op->charcount = font.charcount;
4587
4588         if (op->data && copy_to_user(op->data, font.data, c))
4589                 rc = -EFAULT;
4590
4591 out:
4592         kfree(font.data);
4593         return rc;
4594 }
4595
4596 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4597 {
4598         struct console_font font;
4599         int rc = -EINVAL;
4600         int size;
4601
4602         if (vc->vc_mode != KD_TEXT)
4603                 return -EINVAL;
4604         if (!op->data)
4605                 return -EINVAL;
4606         if (op->charcount > 512)
4607                 return -EINVAL;
4608         if (op->width <= 0 || op->width > 32 || !op->height || op->height > 32)
4609                 return -EINVAL;
4610         size = (op->width+7)/8 * 32 * op->charcount;
4611         if (size > max_font_size)
4612                 return -ENOSPC;
4613
4614         font.data = memdup_user(op->data, size);
4615         if (IS_ERR(font.data))
4616                 return PTR_ERR(font.data);
4617
4618         font.charcount = op->charcount;
4619         font.width = op->width;
4620         font.height = op->height;
4621
4622         console_lock();
4623         if (vc->vc_mode != KD_TEXT)
4624                 rc = -EINVAL;
4625         else if (vc->vc_sw->con_font_set)
4626                 rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4627         else
4628                 rc = -ENOSYS;
4629         console_unlock();
4630         kfree(font.data);
4631         return rc;
4632 }
4633
4634 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4635 {
4636         struct console_font font = {.width = op->width, .height = op->height};
4637         char name[MAX_FONT_NAME];
4638         char *s = name;
4639         int rc;
4640
4641
4642         if (!op->data)
4643                 s = NULL;
4644         else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4645                 return -EFAULT;
4646         else
4647                 name[MAX_FONT_NAME - 1] = 0;
4648
4649         console_lock();
4650         if (vc->vc_mode != KD_TEXT) {
4651                 console_unlock();
4652                 return -EINVAL;
4653         }
4654         if (vc->vc_sw->con_font_default)
4655                 rc = vc->vc_sw->con_font_default(vc, &font, s);
4656         else
4657                 rc = -ENOSYS;
4658         console_unlock();
4659         if (!rc) {
4660                 op->width = font.width;
4661                 op->height = font.height;
4662         }
4663         return rc;
4664 }
4665
4666 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4667 {
4668         switch (op->op) {
4669         case KD_FONT_OP_SET:
4670                 return con_font_set(vc, op);
4671         case KD_FONT_OP_GET:
4672                 return con_font_get(vc, op);
4673         case KD_FONT_OP_SET_DEFAULT:
4674                 return con_font_default(vc, op);
4675         case KD_FONT_OP_COPY:
4676                 /* was buggy and never really used */
4677                 return -EINVAL;
4678         }
4679         return -ENOSYS;
4680 }
4681
4682 /*
4683  *      Interface exported to selection and vcs.
4684  */
4685
4686 /* used by selection */
4687 u16 screen_glyph(const struct vc_data *vc, int offset)
4688 {
4689         u16 w = scr_readw(screenpos(vc, offset, true));
4690         u16 c = w & 0xff;
4691
4692         if (w & vc->vc_hi_font_mask)
4693                 c |= 0x100;
4694         return c;
4695 }
4696 EXPORT_SYMBOL_GPL(screen_glyph);
4697
4698 u32 screen_glyph_unicode(const struct vc_data *vc, int n)
4699 {
4700         struct uni_screen *uniscr = get_vc_uniscr(vc);
4701
4702         if (uniscr)
4703                 return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4704         return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4705 }
4706 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4707
4708 /* used by vcs - note the word offset */
4709 unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
4710 {
4711         return screenpos(vc, 2 * w_offset, viewed);
4712 }
4713 EXPORT_SYMBOL_GPL(screen_pos);
4714
4715 void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
4716 {
4717         /* clamp values if they don't fit */
4718         xy[0] = min(vc->state.x, 0xFFu);
4719         xy[1] = min(vc->state.y, 0xFFu);
4720 }
4721
4722 void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
4723 {
4724         hide_cursor(vc);
4725         gotoxy(vc, xy[0], xy[1]);
4726         set_cursor(vc);
4727 }
4728
4729 u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
4730 {
4731         if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4732                 return softcursor_original;
4733         return scr_readw(org);
4734 }
4735
4736 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4737 {
4738         scr_writew(val, org);
4739         if ((unsigned long)org == vc->vc_pos) {
4740                 softcursor_original = -1;
4741                 add_softcursor(vc);
4742         }
4743 }
4744
4745 void vcs_scr_updated(struct vc_data *vc)
4746 {
4747         notify_update(vc);
4748 }
4749
4750 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4751                 unsigned int rolled_over, void *base, unsigned int size)
4752 {
4753         unsigned long ubase = (unsigned long)base;
4754         ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4755         ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4756         ptrdiff_t origin = (void *)c->vc_origin - base;
4757         int margin = c->vc_size_row * 4;
4758         int from, wrap, from_off, avail;
4759
4760         /* Turn scrollback off */
4761         if (!lines) {
4762                 c->vc_visible_origin = c->vc_origin;
4763                 return;
4764         }
4765
4766         /* Do we have already enough to allow jumping from 0 to the end? */
4767         if (rolled_over > scr_end + margin) {
4768                 from = scr_end;
4769                 wrap = rolled_over + c->vc_size_row;
4770         } else {
4771                 from = 0;
4772                 wrap = size;
4773         }
4774
4775         from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4776         avail = (origin - from + wrap) % wrap;
4777
4778         /* Only a little piece would be left? Show all incl. the piece! */
4779         if (avail < 2 * margin)
4780                 margin = 0;
4781         if (from_off < margin)
4782                 from_off = 0;
4783         if (from_off > avail - margin)
4784                 from_off = avail;
4785
4786         c->vc_visible_origin = ubase + (from + from_off) % wrap;
4787 }
4788 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4789
4790 /*
4791  *      Visible symbols for modules
4792  */
4793
4794 EXPORT_SYMBOL(color_table);
4795 EXPORT_SYMBOL(default_red);
4796 EXPORT_SYMBOL(default_grn);
4797 EXPORT_SYMBOL(default_blu);
4798 EXPORT_SYMBOL(update_region);
4799 EXPORT_SYMBOL(redraw_screen);
4800 EXPORT_SYMBOL(vc_resize);
4801 EXPORT_SYMBOL(fg_console);
4802 EXPORT_SYMBOL(console_blank_hook);
4803 EXPORT_SYMBOL(console_blanked);
4804 EXPORT_SYMBOL(vc_cons);
4805 EXPORT_SYMBOL(global_cursor_default);
4806 #ifndef VT_SINGLE_DRIVER
4807 EXPORT_SYMBOL(give_up_console);
4808 #endif