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 = vzalloc(memsize);
 348         if (!p)
 349                 return NULL;
 350
 351         /* initial line pointers */
 352         uniscr = p;
 353         p = uniscr->lines + rows;
 354         for (i = 0; i < rows; i++) {
 355                 uniscr->lines[i] = p;
 356                 p += cols * sizeof(char32_t);
 357         }
 358         return uniscr;
 359 }
 360
 361 static void vc_uniscr_free(struct uni_screen *uniscr)
 362 {
 363         vfree(uniscr);
 364 }
 365
 366 static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
 367 {
 368         vc_uniscr_free(vc->vc_uni_screen);
 369         vc->vc_uni_screen = new_uniscr;
 370 }
 371
 372 static void vc_uniscr_putc(struct vc_data *vc, char32_t uc)
 373 {
 374         struct uni_screen *uniscr = get_vc_uniscr(vc);
 375
 376         if (uniscr)
 377                 uniscr->lines[vc->state.y][vc->state.x] = uc;
 378 }
 379
 380 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
 381 {
 382         struct uni_screen *uniscr = get_vc_uniscr(vc);
 383
 384         if (uniscr) {
 385                 char32_t *ln = uniscr->lines[vc->state.y];
 386                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 387
 388                 memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
 389                 memset32(&ln[x], ' ', nr);
 390         }
 391 }
 392
 393 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
 394 {
 395         struct uni_screen *uniscr = get_vc_uniscr(vc);
 396
 397         if (uniscr) {
 398                 char32_t *ln = uniscr->lines[vc->state.y];
 399                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 400
 401                 memmove(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
 402                 memset32(&ln[cols - nr], ' ', nr);
 403         }
 404 }
 405
 406 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
 407                                  unsigned int nr)
 408 {
 409         struct uni_screen *uniscr = get_vc_uniscr(vc);
 410
 411         if (uniscr) {
 412                 char32_t *ln = uniscr->lines[vc->state.y];
 413
 414                 memset32(&ln[x], ' ', nr);
 415         }
 416 }
 417
 418 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
 419                                   unsigned int nr)
 420 {
 421         struct uni_screen *uniscr = get_vc_uniscr(vc);
 422
 423         if (uniscr) {
 424                 unsigned int cols = vc->vc_cols;
 425
 426                 while (nr--)
 427                         memset32(uniscr->lines[y++], ' ', cols);
 428         }
 429 }
 430
 431 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 432                              enum con_scroll dir, unsigned int nr)
 433 {
 434         struct uni_screen *uniscr = get_vc_uniscr(vc);
 435
 436         if (uniscr) {
 437                 unsigned int i, j, k, sz, d, clear;
 438
 439                 sz = b - t;
 440                 clear = b - nr;
 441                 d = nr;
 442                 if (dir == SM_DOWN) {
 443                         clear = t;
 444                         d = sz - nr;
 445                 }
 446                 for (i = 0; i < gcd(d, sz); i++) {
 447                         char32_t *tmp = uniscr->lines[t + i];
 448                         j = i;
 449                         while (1) {
 450                                 k = j + d;
 451                                 if (k >= sz)
 452                                         k -= sz;
 453                                 if (k == i)
 454                                         break;
 455                                 uniscr->lines[t + j] = uniscr->lines[t + k];
 456                                 j = k;
 457                         }
 458                         uniscr->lines[t + j] = tmp;
 459                 }
 460                 vc_uniscr_clear_lines(vc, clear, nr);
 461         }
 462 }
 463
 464 static void vc_uniscr_copy_area(struct uni_screen *dst,
 465                                 unsigned int dst_cols,
 466                                 unsigned int dst_rows,
 467                                 struct uni_screen *src,
 468                                 unsigned int src_cols,
 469                                 unsigned int src_top_row,
 470                                 unsigned int src_bot_row)
 471 {
 472         unsigned int dst_row = 0;
 473
 474         if (!dst)
 475                 return;
 476
 477         while (src_top_row < src_bot_row) {
 478                 char32_t *src_line = src->lines[src_top_row];
 479                 char32_t *dst_line = dst->lines[dst_row];
 480
 481                 memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
 482                 if (dst_cols - src_cols)
 483                         memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
 484                 src_top_row++;
 485                 dst_row++;
 486         }
 487         while (dst_row < dst_rows) {
 488                 char32_t *dst_line = dst->lines[dst_row];
 489
 490                 memset32(dst_line, ' ', dst_cols);
 491                 dst_row++;
 492         }
 493 }
 494
 495 /*
 496  * Called from vcs_read() to make sure unicode screen retrieval is possible.
 497  * This will initialize the unicode screen buffer if not already done.
 498  * This returns 0 if OK, or a negative error code otherwise.
 499  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
 500  */
 501 int vc_uniscr_check(struct vc_data *vc)
 502 {
 503         struct uni_screen *uniscr;
 504         unsigned short *p;
 505         int x, y, mask;
 506
 507         if (__is_defined(NO_VC_UNI_SCREEN))
 508                 return -EOPNOTSUPP;
 509
 510         WARN_CONSOLE_UNLOCKED();
 511
 512         if (!vc->vc_utf)
 513                 return -ENODATA;
 514
 515         if (vc->vc_uni_screen)
 516                 return 0;
 517
 518         uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
 519         if (!uniscr)
 520                 return -ENOMEM;
 521
 522         /*
 523          * Let's populate it initially with (imperfect) reverse translation.
 524          * This is the next best thing we can do short of having it enabled
 525          * from the start even when no users rely on this functionality. True
 526          * unicode content will be available after a complete screen refresh.
 527          */
 528         p = (unsigned short *)vc->vc_origin;
 529         mask = vc->vc_hi_font_mask | 0xff;
 530         for (y = 0; y < vc->vc_rows; y++) {
 531                 char32_t *line = uniscr->lines[y];
 532                 for (x = 0; x < vc->vc_cols; x++) {
 533                         u16 glyph = scr_readw(p++) & mask;
 534                         line[x] = inverse_translate(vc, glyph, true);
 535                 }
 536         }
 537
 538         vc->vc_uni_screen = uniscr;
 539         return 0;
 540 }
 541
 542 /*
 543  * Called from vcs_read() to get the unicode data from the screen.
 544  * This must be preceded by a successful call to vc_uniscr_check() once
 545  * the console lock has been taken.
 546  */
 547 void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed,
 548                          unsigned int row, unsigned int col, unsigned int nr)
 549 {
 550         struct uni_screen *uniscr = get_vc_uniscr(vc);
 551         int offset = row * vc->vc_size_row + col * 2;
 552         unsigned long pos;
 553
 554         BUG_ON(!uniscr);
 555
 556         pos = (unsigned long)screenpos(vc, offset, viewed);
 557         if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
 558                 /*
 559                  * Desired position falls in the main screen buffer.
 560                  * However the actual row/col might be different if
 561                  * scrollback is active.
 562                  */
 563                 row = (pos - vc->vc_origin) / vc->vc_size_row;
 564                 col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
 565                 memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t));
 566         } else {
 567                 /*
 568                  * Scrollback is active. For now let's simply backtranslate
 569                  * the screen glyphs until the unicode screen buffer does
 570                  * synchronize with console display drivers for a scrollback
 571                  * buffer of its own.
 572                  */
 573                 u16 *p = (u16 *)pos;
 574                 int mask = vc->vc_hi_font_mask | 0xff;
 575                 char32_t *uni_buf = dest;
 576                 while (nr--) {
 577                         u16 glyph = scr_readw(p++) & mask;
 578                         *uni_buf++ = inverse_translate(vc, glyph, true);
 579                 }
 580         }
 581 }
 582
 583 /* this is for validation and debugging only */
 584 static void vc_uniscr_debug_check(struct vc_data *vc)
 585 {
 586         struct uni_screen *uniscr = get_vc_uniscr(vc);
 587         unsigned short *p;
 588         int x, y, mask;
 589
 590         if (!VC_UNI_SCREEN_DEBUG || !uniscr)
 591                 return;
 592
 593         WARN_CONSOLE_UNLOCKED();
 594
 595         /*
 596          * Make sure our unicode screen translates into the same glyphs
 597          * as the actual screen. This is brutal indeed.
 598          */
 599         p = (unsigned short *)vc->vc_origin;
 600         mask = vc->vc_hi_font_mask | 0xff;
 601         for (y = 0; y < vc->vc_rows; y++) {
 602                 char32_t *line = uniscr->lines[y];
 603                 for (x = 0; x < vc->vc_cols; x++) {
 604                         u16 glyph = scr_readw(p++) & mask;
 605                         char32_t uc = line[x];
 606                         int tc = conv_uni_to_pc(vc, uc);
 607                         if (tc == -4)
 608                                 tc = conv_uni_to_pc(vc, 0xfffd);
 609                         if (tc == -4)
 610                                 tc = conv_uni_to_pc(vc, '?');
 611                         if (tc != glyph)
 612                                 pr_err_ratelimited(
 613                                         "%s: mismatch at %d,%d: glyph=%#x tc=%#x\n",
 614                                         __func__, x, y, glyph, tc);
 615                 }
 616         }
 617 }
 618
 619
 620 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 621                 enum con_scroll dir, unsigned int nr)
 622 {
 623         u16 *clear, *d, *s;
 624
 625         if (t + nr >= b)
 626                 nr = b - t - 1;
 627         if (b > vc->vc_rows || t >= b || nr < 1)
 628                 return;
 629         vc_uniscr_scroll(vc, t, b, dir, nr);
 630         if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
 631                 return;
 632
 633         s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
 634         d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
 635
 636         if (dir == SM_UP) {
 637                 clear = s + (b - t - nr) * vc->vc_cols;
 638                 swap(s, d);
 639         }
 640         scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
 641         scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
 642 }
 643
 644 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 645 {
 646         unsigned int xx, yy, offset;
 647         u16 *p;
 648
 649         p = (u16 *) start;
 650         if (!vc->vc_sw->con_getxy) {
 651                 offset = (start - vc->vc_origin) / 2;
 652                 xx = offset % vc->vc_cols;
 653                 yy = offset / vc->vc_cols;
 654         } else {
 655                 int nxx, nyy;
 656                 start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
 657                 xx = nxx; yy = nyy;
 658         }
 659         for(;;) {
 660                 u16 attrib = scr_readw(p) & 0xff00;
 661                 int startx = xx;
 662                 u16 *q = p;
 663                 while (xx < vc->vc_cols && count) {
 664                         if (attrib != (scr_readw(p) & 0xff00)) {
 665                                 if (p > q)
 666                                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 667                                 startx = xx;
 668                                 q = p;
 669                                 attrib = scr_readw(p) & 0xff00;
 670                         }
 671                         p++;
 672                         xx++;
 673                         count--;
 674                 }
 675                 if (p > q)
 676                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 677                 if (!count)
 678                         break;
 679                 xx = 0;
 680                 yy++;
 681                 if (vc->vc_sw->con_getxy) {
 682                         p = (u16 *)start;
 683                         start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
 684                 }
 685         }
 686 }
 687
 688 void update_region(struct vc_data *vc, unsigned long start, int count)
 689 {
 690         WARN_CONSOLE_UNLOCKED();
 691
 692         if (con_should_update(vc)) {
 693                 hide_cursor(vc);
 694                 do_update_region(vc, start, count);
 695                 set_cursor(vc);
 696         }
 697 }
 698
 699 /* Structure of attributes is hardware-dependent */
 700
 701 static u8 build_attr(struct vc_data *vc, u8 _color,
 702                 enum vc_intensity _intensity, bool _blink, bool _underline,
 703                 bool _reverse, bool _italic)
 704 {
 705         if (vc->vc_sw->con_build_attr)
 706                 return vc->vc_sw->con_build_attr(vc, _color, _intensity,
 707                        _blink, _underline, _reverse, _italic);
 708
 709 /*
 710  * ++roman: I completely changed the attribute format for monochrome
 711  * mode (!can_do_color). The formerly used MDA (monochrome display
 712  * adapter) format didn't allow the combination of certain effects.
 713  * Now the attribute is just a bit vector:
 714  *  Bit 0..1: intensity (0..2)
 715  *  Bit 2   : underline
 716  *  Bit 3   : reverse
 717  *  Bit 7   : blink
 718  */
 719         {
 720         u8 a = _color;
 721         if (!vc->vc_can_do_color)
 722                 return _intensity |
 723                        (_italic    << 1) |
 724                        (_underline << 2) |
 725                        (_reverse   << 3) |
 726                        (_blink     << 7);
 727         if (_italic)
 728                 a = (a & 0xF0) | vc->vc_itcolor;
 729         else if (_underline)
 730                 a = (a & 0xf0) | vc->vc_ulcolor;
 731         else if (_intensity == VCI_HALF_BRIGHT)
 732                 a = (a & 0xf0) | vc->vc_halfcolor;
 733         if (_reverse)
 734                 a = (a & 0x88) | (((a >> 4) | (a << 4)) & 0x77);
 735         if (_blink)
 736                 a ^= 0x80;
 737         if (_intensity == VCI_BOLD)
 738                 a ^= 0x08;
 739         if (vc->vc_hi_font_mask == 0x100)
 740                 a <<= 1;
 741         return a;
 742         }
 743 }
 744
 745 static void update_attr(struct vc_data *vc)
 746 {
 747         vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
 748                       vc->state.blink, vc->state.underline,
 749                       vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
 750         vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
 751                                 VCI_NORMAL, vc->state.blink, false,
 752                                 vc->vc_decscnm, false) << 8);
 753 }
 754
 755 /* Note: inverting the screen twice should revert to the original state */
 756 void invert_screen(struct vc_data *vc, int offset, int count, bool viewed)
 757 {
 758         unsigned short *p;
 759
 760         WARN_CONSOLE_UNLOCKED();
 761
 762         count /= 2;
 763         p = screenpos(vc, offset, viewed);
 764         if (vc->vc_sw->con_invert_region) {
 765                 vc->vc_sw->con_invert_region(vc, p, count);
 766         } else {
 767                 u16 *q = p;
 768                 int cnt = count;
 769                 u16 a;
 770
 771                 if (!vc->vc_can_do_color) {
 772                         while (cnt--) {
 773                             a = scr_readw(q);
 774                             a ^= 0x0800;
 775                             scr_writew(a, q);
 776                             q++;
 777                         }
 778                 } else if (vc->vc_hi_font_mask == 0x100) {
 779                         while (cnt--) {
 780                                 a = scr_readw(q);
 781                                 a = (a & 0x11ff) |
 782                                    ((a & 0xe000) >> 4) |
 783                                    ((a & 0x0e00) << 4);
 784                                 scr_writew(a, q);
 785                                 q++;
 786                         }
 787                 } else {
 788                         while (cnt--) {
 789                                 a = scr_readw(q);
 790                                 a = (a & 0x88ff) |
 791                                    ((a & 0x7000) >> 4) |
 792                                    ((a & 0x0700) << 4);
 793                                 scr_writew(a, q);
 794                                 q++;
 795                         }
 796                 }
 797         }
 798
 799         if (con_should_update(vc))
 800                 do_update_region(vc, (unsigned long) p, count);
 801         notify_update(vc);
 802 }
 803
 804 /* used by selection: complement pointer position */
 805 void complement_pos(struct vc_data *vc, int offset)
 806 {
 807         static int old_offset = -1;
 808         static unsigned short old;
 809         static unsigned short oldx, oldy;
 810
 811         WARN_CONSOLE_UNLOCKED();
 812
 813         if (old_offset != -1 && old_offset >= 0 &&
 814             old_offset < vc->vc_screenbuf_size) {
 815                 scr_writew(old, screenpos(vc, old_offset, true));
 816                 if (con_should_update(vc))
 817                         vc->vc_sw->con_putc(vc, old, oldy, oldx);
 818                 notify_update(vc);
 819         }
 820
 821         old_offset = offset;
 822
 823         if (offset != -1 && offset >= 0 &&
 824             offset < vc->vc_screenbuf_size) {
 825                 unsigned short new;
 826                 unsigned short *p;
 827                 p = screenpos(vc, offset, true);
 828                 old = scr_readw(p);
 829                 new = old ^ vc->vc_complement_mask;
 830                 scr_writew(new, p);
 831                 if (con_should_update(vc)) {
 832                         oldx = (offset >> 1) % vc->vc_cols;
 833                         oldy = (offset >> 1) / vc->vc_cols;
 834                         vc->vc_sw->con_putc(vc, new, oldy, oldx);
 835                 }
 836                 notify_update(vc);
 837         }
 838 }
 839
 840 static void insert_char(struct vc_data *vc, unsigned int nr)
 841 {
 842         unsigned short *p = (unsigned short *) vc->vc_pos;
 843
 844         vc_uniscr_insert(vc, nr);
 845         scr_memmovew(p + nr, p, (vc->vc_cols - vc->state.x - nr) * 2);
 846         scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
 847         vc->vc_need_wrap = 0;
 848         if (con_should_update(vc))
 849                 do_update_region(vc, (unsigned long) p,
 850                         vc->vc_cols - vc->state.x);
 851 }
 852
 853 static void delete_char(struct vc_data *vc, unsigned int nr)
 854 {
 855         unsigned short *p = (unsigned short *) vc->vc_pos;
 856
 857         vc_uniscr_delete(vc, nr);
 858         scr_memmovew(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
 859         scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
 860                         nr * 2);
 861         vc->vc_need_wrap = 0;
 862         if (con_should_update(vc))
 863                 do_update_region(vc, (unsigned long) p,
 864                         vc->vc_cols - vc->state.x);
 865 }
 866
 867 static int softcursor_original = -1;
 868
 869 static void add_softcursor(struct vc_data *vc)
 870 {
 871         int i = scr_readw((u16 *) vc->vc_pos);
 872         u32 type = vc->vc_cursor_type;
 873
 874         if (!(type & CUR_SW))
 875                 return;
 876         if (softcursor_original != -1)
 877                 return;
 878         softcursor_original = i;
 879         i |= CUR_SET(type);
 880         i ^= CUR_CHANGE(type);
 881         if ((type & CUR_ALWAYS_BG) &&
 882                         (softcursor_original & CUR_BG) == (i & CUR_BG))
 883                 i ^= CUR_BG;
 884         if ((type & CUR_INVERT_FG_BG) && (i & CUR_FG) == ((i & CUR_BG) >> 4))
 885                 i ^= CUR_FG;
 886         scr_writew(i, (u16 *)vc->vc_pos);
 887         if (con_should_update(vc))
 888                 vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
 889 }
 890
 891 static void hide_softcursor(struct vc_data *vc)
 892 {
 893         if (softcursor_original != -1) {
 894                 scr_writew(softcursor_original, (u16 *)vc->vc_pos);
 895                 if (con_should_update(vc))
 896                         vc->vc_sw->con_putc(vc, softcursor_original,
 897                                         vc->state.y, vc->state.x);
 898                 softcursor_original = -1;
 899         }
 900 }
 901
 902 static void hide_cursor(struct vc_data *vc)
 903 {
 904         if (vc_is_sel(vc))
 905                 clear_selection();
 906
 907         vc->vc_sw->con_cursor(vc, CM_ERASE);
 908         hide_softcursor(vc);
 909 }
 910
 911 static void set_cursor(struct vc_data *vc)
 912 {
 913         if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
 914                 return;
 915         if (vc->vc_deccm) {
 916                 if (vc_is_sel(vc))
 917                         clear_selection();
 918                 add_softcursor(vc);
 919                 if (CUR_SIZE(vc->vc_cursor_type) != CUR_NONE)
 920                         vc->vc_sw->con_cursor(vc, CM_DRAW);
 921         } else
 922                 hide_cursor(vc);
 923 }
 924
 925 static void set_origin(struct vc_data *vc)
 926 {
 927         WARN_CONSOLE_UNLOCKED();
 928
 929         if (!con_is_visible(vc) ||
 930             !vc->vc_sw->con_set_origin ||
 931             !vc->vc_sw->con_set_origin(vc))
 932                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
 933         vc->vc_visible_origin = vc->vc_origin;
 934         vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
 935         vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->state.y +
 936                 2 * vc->state.x;
 937 }
 938
 939 static void save_screen(struct vc_data *vc)
 940 {
 941         WARN_CONSOLE_UNLOCKED();
 942
 943         if (vc->vc_sw->con_save_screen)
 944                 vc->vc_sw->con_save_screen(vc);
 945 }
 946
 947 static void flush_scrollback(struct vc_data *vc)
 948 {
 949         WARN_CONSOLE_UNLOCKED();
 950
 951         set_origin(vc);
 952         if (vc->vc_sw->con_flush_scrollback) {
 953                 vc->vc_sw->con_flush_scrollback(vc);
 954         } else if (con_is_visible(vc)) {
 955                 /*
 956                  * When no con_flush_scrollback method is provided then the
 957                  * legacy way for flushing the scrollback buffer is to use
 958                  * a side effect of the con_switch method. We do it only on
 959                  * the foreground console as background consoles have no
 960                  * scrollback buffers in that case and we obviously don't
 961                  * want to switch to them.
 962                  */
 963                 hide_cursor(vc);
 964                 vc->vc_sw->con_switch(vc);
 965                 set_cursor(vc);
 966         }
 967 }
 968
 969 /*
 970  *      Redrawing of screen
 971  */
 972
 973 void clear_buffer_attributes(struct vc_data *vc)
 974 {
 975         unsigned short *p = (unsigned short *)vc->vc_origin;
 976         int count = vc->vc_screenbuf_size / 2;
 977         int mask = vc->vc_hi_font_mask | 0xff;
 978
 979         for (; count > 0; count--, p++) {
 980                 scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
 981         }
 982 }
 983
 984 void redraw_screen(struct vc_data *vc, int is_switch)
 985 {
 986         int redraw = 0;
 987
 988         WARN_CONSOLE_UNLOCKED();
 989
 990         if (!vc) {
 991                 /* strange ... */
 992                 /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
 993                 return;
 994         }
 995
 996         if (is_switch) {
 997                 struct vc_data *old_vc = vc_cons[fg_console].d;
 998                 if (old_vc == vc)
 999                         return;
1000                 if (!con_is_visible(vc))
1001                         redraw = 1;
1002                 *vc->vc_display_fg = vc;
1003                 fg_console = vc->vc_num;
1004                 hide_cursor(old_vc);
1005                 if (!con_is_visible(old_vc)) {
1006                         save_screen(old_vc);
1007                         set_origin(old_vc);
1008                 }
1009                 if (tty0dev)
1010                         sysfs_notify(&tty0dev->kobj, NULL, "active");
1011         } else {
1012                 hide_cursor(vc);
1013                 redraw = 1;
1014         }
1015
1016         if (redraw) {
1017                 int update;
1018                 int old_was_color = vc->vc_can_do_color;
1019
1020                 set_origin(vc);
1021                 update = vc->vc_sw->con_switch(vc);
1022                 set_palette(vc);
1023                 /*
1024                  * If console changed from mono<->color, the best we can do
1025                  * is to clear the buffer attributes. As it currently stands,
1026                  * rebuilding new attributes from the old buffer is not doable
1027                  * without overly complex code.
1028                  */
1029                 if (old_was_color != vc->vc_can_do_color) {
1030                         update_attr(vc);
1031                         clear_buffer_attributes(vc);
1032                 }
1033
1034                 if (update && vc->vc_mode != KD_GRAPHICS)
1035                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1036         }
1037         set_cursor(vc);
1038         if (is_switch) {
1039                 set_leds();
1040                 compute_shiftstate();
1041                 notify_update(vc);
1042         }
1043 }
1044
1045 /*
1046  *      Allocation, freeing and resizing of VTs.
1047  */
1048
1049 int vc_cons_allocated(unsigned int i)
1050 {
1051         return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1052 }
1053
1054 static void visual_init(struct vc_data *vc, int num, int init)
1055 {
1056         /* ++Geert: vc->vc_sw->con_init determines console size */
1057         if (vc->vc_sw)
1058                 module_put(vc->vc_sw->owner);
1059         vc->vc_sw = conswitchp;
1060 #ifndef VT_SINGLE_DRIVER
1061         if (con_driver_map[num])
1062                 vc->vc_sw = con_driver_map[num];
1063 #endif
1064         __module_get(vc->vc_sw->owner);
1065         vc->vc_num = num;
1066         vc->vc_display_fg = &master_display_fg;
1067         if (vc->vc_uni_pagedir_loc)
1068                 con_free_unimap(vc);
1069         vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
1070         vc->vc_uni_pagedir = NULL;
1071         vc->vc_hi_font_mask = 0;
1072         vc->vc_complement_mask = 0;
1073         vc->vc_can_do_color = 0;
1074         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1075         vc->vc_sw->con_init(vc, init);
1076         if (!vc->vc_complement_mask)
1077                 vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1078         vc->vc_s_complement_mask = vc->vc_complement_mask;
1079         vc->vc_size_row = vc->vc_cols << 1;
1080         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1081 }
1082
1083
1084 static void visual_deinit(struct vc_data *vc)
1085 {
1086         vc->vc_sw->con_deinit(vc);
1087         module_put(vc->vc_sw->owner);
1088 }
1089
1090 static void vc_port_destruct(struct tty_port *port)
1091 {
1092         struct vc_data *vc = container_of(port, struct vc_data, port);
1093
1094         kfree(vc);
1095 }
1096
1097 static const struct tty_port_operations vc_port_ops = {
1098         .destruct = vc_port_destruct,
1099 };
1100
1101 /*
1102  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1103  * [this is to be used together with some user program
1104  * like resize that changes the hardware videomode]
1105  */
1106 #define VC_MAXCOL (32767)
1107 #define VC_MAXROW (32767)
1108
1109 int vc_allocate(unsigned int currcons)  /* return 0 on success */
1110 {
1111         struct vt_notifier_param param;
1112         struct vc_data *vc;
1113         int err;
1114
1115         WARN_CONSOLE_UNLOCKED();
1116
1117         if (currcons >= MAX_NR_CONSOLES)
1118                 return -ENXIO;
1119
1120         if (vc_cons[currcons].d)
1121                 return 0;
1122
1123         /* due to the granularity of kmalloc, we waste some memory here */
1124         /* the alloc is done in two steps, to optimize the common situation
1125            of a 25x80 console (structsize=216, screenbuf_size=4000) */
1126         /* although the numbers above are not valid since long ago, the
1127            point is still up-to-date and the comment still has its value
1128            even if only as a historical artifact.  --mj, July 1998 */
1129         param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1130         if (!vc)
1131                 return -ENOMEM;
1132
1133         vc_cons[currcons].d = vc;
1134         tty_port_init(&vc->port);
1135         vc->port.ops = &vc_port_ops;
1136         INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1137
1138         visual_init(vc, currcons, 1);
1139
1140         if (!*vc->vc_uni_pagedir_loc)
1141                 con_set_default_unimap(vc);
1142
1143         err = -EINVAL;
1144         if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
1145             vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
1146                 goto err_free;
1147         err = -ENOMEM;
1148         vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1149         if (!vc->vc_screenbuf)
1150                 goto err_free;
1151
1152         /* If no drivers have overridden us and the user didn't pass a
1153            boot option, default to displaying the cursor */
1154         if (global_cursor_default == -1)
1155                 global_cursor_default = 1;
1156
1157         vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
1158         vcs_make_sysfs(currcons);
1159         atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1160
1161         return 0;
1162 err_free:
1163         visual_deinit(vc);
1164         kfree(vc);
1165         vc_cons[currcons].d = NULL;
1166         return err;
1167 }
1168
1169 static inline int resize_screen(struct vc_data *vc, int width, int height,
1170                                 int user)
1171 {
1172         /* Resizes the resolution of the display adapater */
1173         int err = 0;
1174
1175         if (vc->vc_sw->con_resize)
1176                 err = vc->vc_sw->con_resize(vc, width, height, user);
1177
1178         return err;
1179 }
1180
1181 /**
1182  *      vc_do_resize    -       resizing method for the tty
1183  *      @tty: tty being resized
1184  *      @vc: virtual console private data
1185  *      @cols: columns
1186  *      @lines: lines
1187  *
1188  *      Resize a virtual console, clipping according to the actual constraints.
1189  *      If the caller passes a tty structure then update the termios winsize
1190  *      information and perform any necessary signal handling.
1191  *
1192  *      Caller must hold the console semaphore. Takes the termios rwsem and
1193  *      ctrl_lock of the tty IFF a tty is passed.
1194  */
1195
1196 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1197                                 unsigned int cols, unsigned int lines)
1198 {
1199         unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1200         unsigned long end;
1201         unsigned int old_rows, old_row_size, first_copied_row;
1202         unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1203         unsigned int user;
1204         unsigned short *oldscreen, *newscreen;
1205         struct uni_screen *new_uniscr = NULL;
1206
1207         WARN_CONSOLE_UNLOCKED();
1208
1209         if (!vc)
1210                 return -ENXIO;
1211
1212         user = vc->vc_resize_user;
1213         vc->vc_resize_user = 0;
1214
1215         if (cols > VC_MAXCOL || lines > VC_MAXROW)
1216                 return -EINVAL;
1217
1218         new_cols = (cols ? cols : vc->vc_cols);
1219         new_rows = (lines ? lines : vc->vc_rows);
1220         new_row_size = new_cols << 1;
1221         new_screen_size = new_row_size * new_rows;
1222
1223         if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) {
1224                 /*
1225                  * This function is being called here to cover the case
1226                  * where the userspace calls the FBIOPUT_VSCREENINFO twice,
1227                  * passing the same fb_var_screeninfo containing the fields
1228                  * yres/xres equal to a number non-multiple of vc_font.height
1229                  * and yres_virtual/xres_virtual equal to number lesser than the
1230                  * vc_font.height and yres/xres.
1231                  * In the second call, the struct fb_var_screeninfo isn't
1232                  * being modified by the underlying driver because of the
1233                  * if above, and this causes the fbcon_display->vrows to become
1234                  * negative and it eventually leads to out-of-bound
1235                  * access by the imageblit function.
1236                  * To give the correct values to the struct and to not have
1237                  * to deal with possible errors from the code below, we call
1238                  * the resize_screen here as well.
1239                  */
1240                 return resize_screen(vc, new_cols, new_rows, user);
1241         }
1242
1243         if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
1244                 return -EINVAL;
1245         newscreen = kzalloc(new_screen_size, GFP_USER);
1246         if (!newscreen)
1247                 return -ENOMEM;
1248
1249         if (get_vc_uniscr(vc)) {
1250                 new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1251                 if (!new_uniscr) {
1252                         kfree(newscreen);
1253                         return -ENOMEM;
1254                 }
1255         }
1256
1257         if (vc_is_sel(vc))
1258                 clear_selection();
1259
1260         old_rows = vc->vc_rows;
1261         old_row_size = vc->vc_size_row;
1262
1263         err = resize_screen(vc, new_cols, new_rows, user);
1264         if (err) {
1265                 kfree(newscreen);
1266                 vc_uniscr_free(new_uniscr);
1267                 return err;
1268         }
1269
1270         vc->vc_rows = new_rows;
1271         vc->vc_cols = new_cols;
1272         vc->vc_size_row = new_row_size;
1273         vc->vc_screenbuf_size = new_screen_size;
1274
1275         rlth = min(old_row_size, new_row_size);
1276         rrem = new_row_size - rlth;
1277         old_origin = vc->vc_origin;
1278         new_origin = (long) newscreen;
1279         new_scr_end = new_origin + new_screen_size;
1280
1281         if (vc->state.y > new_rows) {
1282                 if (old_rows - vc->state.y < new_rows) {
1283                         /*
1284                          * Cursor near the bottom, copy contents from the
1285                          * bottom of buffer
1286                          */
1287                         first_copied_row = (old_rows - new_rows);
1288                 } else {
1289                         /*
1290                          * Cursor is in no man's land, copy 1/2 screenful
1291                          * from the top and bottom of cursor position
1292                          */
1293                         first_copied_row = (vc->state.y - new_rows/2);
1294                 }
1295                 old_origin += first_copied_row * old_row_size;
1296         } else
1297                 first_copied_row = 0;
1298         end = old_origin + old_row_size * min(old_rows, new_rows);
1299
1300         vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1301                             get_vc_uniscr(vc), rlth/2, first_copied_row,
1302                             min(old_rows, new_rows));
1303         vc_uniscr_set(vc, new_uniscr);
1304
1305         update_attr(vc);
1306
1307         while (old_origin < end) {
1308                 scr_memcpyw((unsigned short *) new_origin,
1309                             (unsigned short *) old_origin, rlth);
1310                 if (rrem)
1311                         scr_memsetw((void *)(new_origin + rlth),
1312                                     vc->vc_video_erase_char, rrem);
1313                 old_origin += old_row_size;
1314                 new_origin += new_row_size;
1315         }
1316         if (new_scr_end > new_origin)
1317                 scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1318                             new_scr_end - new_origin);
1319         oldscreen = vc->vc_screenbuf;
1320         vc->vc_screenbuf = newscreen;
1321         vc->vc_screenbuf_size = new_screen_size;
1322         set_origin(vc);
1323         kfree(oldscreen);
1324
1325         /* do part of a reset_terminal() */
1326         vc->vc_top = 0;
1327         vc->vc_bottom = vc->vc_rows;
1328         gotoxy(vc, vc->state.x, vc->state.y);
1329         save_cur(vc);
1330
1331         if (tty) {
1332                 /* Rewrite the requested winsize data with the actual
1333                    resulting sizes */
1334                 struct winsize ws;
1335                 memset(&ws, 0, sizeof(ws));
1336                 ws.ws_row = vc->vc_rows;
1337                 ws.ws_col = vc->vc_cols;
1338                 ws.ws_ypixel = vc->vc_scan_lines;
1339                 tty_do_resize(tty, &ws);
1340         }
1341
1342         if (con_is_visible(vc))
1343                 update_screen(vc);
1344         vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1345         notify_update(vc);
1346         return err;
1347 }
1348
1349 /**
1350  *      vc_resize               -       resize a VT
1351  *      @vc: virtual console
1352  *      @cols: columns
1353  *      @rows: rows
1354  *
1355  *      Resize a virtual console as seen from the console end of things. We
1356  *      use the common vc_do_resize methods to update the structures. The
1357  *      caller must hold the console sem to protect console internals and
1358  *      vc->port.tty
1359  */
1360
1361 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1362 {
1363         return vc_do_resize(vc->port.tty, vc, cols, rows);
1364 }
1365
1366 /**
1367  *      vt_resize               -       resize a VT
1368  *      @tty: tty to resize
1369  *      @ws: winsize attributes
1370  *
1371  *      Resize a virtual terminal. This is called by the tty layer as we
1372  *      register our own handler for resizing. The mutual helper does all
1373  *      the actual work.
1374  *
1375  *      Takes the console sem and the called methods then take the tty
1376  *      termios_rwsem and the tty ctrl_lock in that order.
1377  */
1378 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1379 {
1380         struct vc_data *vc = tty->driver_data;
1381         int ret;
1382
1383         console_lock();
1384         ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1385         console_unlock();
1386         return ret;
1387 }
1388
1389 struct vc_data *vc_deallocate(unsigned int currcons)
1390 {
1391         struct vc_data *vc = NULL;
1392
1393         WARN_CONSOLE_UNLOCKED();
1394
1395         if (vc_cons_allocated(currcons)) {
1396                 struct vt_notifier_param param;
1397
1398                 param.vc = vc = vc_cons[currcons].d;
1399                 atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1400                 vcs_remove_sysfs(currcons);
1401                 visual_deinit(vc);
1402                 con_free_unimap(vc);
1403                 put_pid(vc->vt_pid);
1404                 vc_uniscr_set(vc, NULL);
1405                 kfree(vc->vc_screenbuf);
1406                 vc_cons[currcons].d = NULL;
1407         }
1408         return vc;
1409 }
1410
1411 /*
1412  *      VT102 emulator
1413  */
1414
1415 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1416
1417 #define set_kbd(vc, x)  vt_set_kbd_mode_bit((vc)->vc_num, (x))
1418 #define clr_kbd(vc, x)  vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1419 #define is_kbd(vc, x)   vt_get_kbd_mode_bit((vc)->vc_num, (x))
1420
1421 #define decarm          VC_REPEAT
1422 #define decckm          VC_CKMODE
1423 #define kbdapplic       VC_APPLIC
1424 #define lnm             VC_CRLF
1425
1426 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1427                                        8,12,10,14, 9,13,11,15 };
1428
1429 /* the default colour table, for VGA+ colour systems */
1430 unsigned char default_red[] = {
1431         0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1432         0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1433 };
1434 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1435
1436 unsigned char default_grn[] = {
1437         0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1438         0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1439 };
1440 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1441
1442 unsigned char default_blu[] = {
1443         0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1444         0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1445 };
1446 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1447
1448 /*
1449  * gotoxy() must verify all boundaries, because the arguments
1450  * might also be negative. If the given position is out of
1451  * bounds, the cursor is placed at the nearest margin.
1452  */
1453 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1454 {
1455         int min_y, max_y;
1456
1457         if (new_x < 0)
1458                 vc->state.x = 0;
1459         else {
1460                 if (new_x >= vc->vc_cols)
1461                         vc->state.x = vc->vc_cols - 1;
1462                 else
1463                         vc->state.x = new_x;
1464         }
1465
1466         if (vc->vc_decom) {
1467                 min_y = vc->vc_top;
1468                 max_y = vc->vc_bottom;
1469         } else {
1470                 min_y = 0;
1471                 max_y = vc->vc_rows;
1472         }
1473         if (new_y < min_y)
1474                 vc->state.y = min_y;
1475         else if (new_y >= max_y)
1476                 vc->state.y = max_y - 1;
1477         else
1478                 vc->state.y = new_y;
1479         vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
1480                 (vc->state.x << 1);
1481         vc->vc_need_wrap = 0;
1482 }
1483
1484 /* for absolute user moves, when decom is set */
1485 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1486 {
1487         gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1488 }
1489
1490 void scrollback(struct vc_data *vc)
1491 {
1492         scrolldelta(-(vc->vc_rows / 2));
1493 }
1494
1495 void scrollfront(struct vc_data *vc, int lines)
1496 {
1497         if (!lines)
1498                 lines = vc->vc_rows / 2;
1499         scrolldelta(lines);
1500 }
1501
1502 static void lf(struct vc_data *vc)
1503 {
1504         /* don't scroll if above bottom of scrolling region, or
1505          * if below scrolling region
1506          */
1507         if (vc->state.y + 1 == vc->vc_bottom)
1508                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1509         else if (vc->state.y < vc->vc_rows - 1) {
1510                 vc->state.y++;
1511                 vc->vc_pos += vc->vc_size_row;
1512         }
1513         vc->vc_need_wrap = 0;
1514         notify_write(vc, '\n');
1515 }
1516
1517 static void ri(struct vc_data *vc)
1518 {
1519         /* don't scroll if below top of scrolling region, or
1520          * if above scrolling region
1521          */
1522         if (vc->state.y == vc->vc_top)
1523                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1524         else if (vc->state.y > 0) {
1525                 vc->state.y--;
1526                 vc->vc_pos -= vc->vc_size_row;
1527         }
1528         vc->vc_need_wrap = 0;
1529 }
1530
1531 static inline void cr(struct vc_data *vc)
1532 {
1533         vc->vc_pos -= vc->state.x << 1;
1534         vc->vc_need_wrap = vc->state.x = 0;
1535         notify_write(vc, '\r');
1536 }
1537
1538 static inline void bs(struct vc_data *vc)
1539 {
1540         if (vc->state.x) {
1541                 vc->vc_pos -= 2;
1542                 vc->state.x--;
1543                 vc->vc_need_wrap = 0;
1544                 notify_write(vc, '\b');
1545         }
1546 }
1547
1548 static inline void del(struct vc_data *vc)
1549 {
1550         /* ignored */
1551 }
1552
1553 static void csi_J(struct vc_data *vc, int vpar)
1554 {
1555         unsigned int count;
1556         unsigned short * start;
1557
1558         switch (vpar) {
1559                 case 0: /* erase from cursor to end of display */
1560                         vc_uniscr_clear_line(vc, vc->state.x,
1561                                              vc->vc_cols - vc->state.x);
1562                         vc_uniscr_clear_lines(vc, vc->state.y + 1,
1563                                               vc->vc_rows - vc->state.y - 1);
1564                         count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1565                         start = (unsigned short *)vc->vc_pos;
1566                         break;
1567                 case 1: /* erase from start to cursor */
1568                         vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
1569                         vc_uniscr_clear_lines(vc, 0, vc->state.y);
1570                         count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1571                         start = (unsigned short *)vc->vc_origin;
1572                         break;
1573                 case 3: /* include scrollback */
1574                         flush_scrollback(vc);
1575                         fallthrough;
1576                 case 2: /* erase whole display */
1577                         vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1578                         count = vc->vc_cols * vc->vc_rows;
1579                         start = (unsigned short *)vc->vc_origin;
1580                         break;
1581                 default:
1582                         return;
1583         }
1584         scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1585         if (con_should_update(vc))
1586                 do_update_region(vc, (unsigned long) start, count);
1587         vc->vc_need_wrap = 0;
1588 }
1589
1590 static void csi_K(struct vc_data *vc, int vpar)
1591 {
1592         unsigned int count;
1593         unsigned short *start = (unsigned short *)vc->vc_pos;
1594         int offset;
1595
1596         switch (vpar) {
1597                 case 0: /* erase from cursor to end of line */
1598                         offset = 0;
1599                         count = vc->vc_cols - vc->state.x;
1600                         break;
1601                 case 1: /* erase from start of line to cursor */
1602                         offset = -vc->state.x;
1603                         count = vc->state.x + 1;
1604                         break;
1605                 case 2: /* erase whole line */
1606                         offset = -vc->state.x;
1607                         count = vc->vc_cols;
1608                         break;
1609                 default:
1610                         return;
1611         }
1612         vc_uniscr_clear_line(vc, vc->state.x + offset, count);
1613         scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1614         vc->vc_need_wrap = 0;
1615         if (con_should_update(vc))
1616                 do_update_region(vc, (unsigned long)(start + offset), count);
1617 }
1618
1619 /* erase the following vpar positions */
1620 static void csi_X(struct vc_data *vc, unsigned int vpar)
1621 {                                         /* not vt100? */
1622         unsigned int count;
1623
1624         if (!vpar)
1625                 vpar++;
1626
1627         count = min(vpar, vc->vc_cols - vc->state.x);
1628
1629         vc_uniscr_clear_line(vc, vc->state.x, count);
1630         scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1631         if (con_should_update(vc))
1632                 vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
1633         vc->vc_need_wrap = 0;
1634 }
1635
1636 static void default_attr(struct vc_data *vc)
1637 {
1638         vc->state.intensity = VCI_NORMAL;
1639         vc->state.italic = false;
1640         vc->state.underline = false;
1641         vc->state.reverse = false;
1642         vc->state.blink = false;
1643         vc->state.color = vc->vc_def_color;
1644 }
1645
1646 struct rgb { u8 r; u8 g; u8 b; };
1647
1648 static void rgb_from_256(int i, struct rgb *c)
1649 {
1650         if (i < 8) {            /* Standard colours. */
1651                 c->r = i&1 ? 0xaa : 0x00;
1652                 c->g = i&2 ? 0xaa : 0x00;
1653                 c->b = i&4 ? 0xaa : 0x00;
1654         } else if (i < 16) {
1655                 c->r = i&1 ? 0xff : 0x55;
1656                 c->g = i&2 ? 0xff : 0x55;
1657                 c->b = i&4 ? 0xff : 0x55;
1658         } else if (i < 232) {   /* 6x6x6 colour cube. */
1659                 c->r = (i - 16) / 36 * 85 / 2;
1660                 c->g = (i - 16) / 6 % 6 * 85 / 2;
1661                 c->b = (i - 16) % 6 * 85 / 2;
1662         } else                  /* Grayscale ramp. */
1663                 c->r = c->g = c->b = i * 10 - 2312;
1664 }
1665
1666 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1667 {
1668         u8 hue = 0, max = max3(c->r, c->g, c->b);
1669
1670         if (c->r > max / 2)
1671                 hue |= 4;
1672         if (c->g > max / 2)
1673                 hue |= 2;
1674         if (c->b > max / 2)
1675                 hue |= 1;
1676
1677         if (hue == 7 && max <= 0x55) {
1678                 hue = 0;
1679                 vc->state.intensity = VCI_BOLD;
1680         } else if (max > 0xaa)
1681                 vc->state.intensity = VCI_BOLD;
1682         else
1683                 vc->state.intensity = VCI_NORMAL;
1684
1685         vc->state.color = (vc->state.color & 0xf0) | hue;
1686 }
1687
1688 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1689 {
1690         /* For backgrounds, err on the dark side. */
1691         vc->state.color = (vc->state.color & 0x0f)
1692                 | (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1693 }
1694
1695 /*
1696  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1697  * and thus need to be detected and ignored by hand. That standard also
1698  * wants : rather than ; as separators but sequences containing : are currently
1699  * completely ignored by the parser.
1700  *
1701  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1702  * supporting them.
1703  */
1704 static int vc_t416_color(struct vc_data *vc, int i,
1705                 void(*set_color)(struct vc_data *vc, const struct rgb *c))
1706 {
1707         struct rgb c;
1708
1709         i++;
1710         if (i > vc->vc_npar)
1711                 return i;
1712
1713         if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1714                 /* 256 colours */
1715                 i++;
1716                 rgb_from_256(vc->vc_par[i], &c);
1717         } else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1718                 /* 24 bit */
1719                 c.r = vc->vc_par[i + 1];
1720                 c.g = vc->vc_par[i + 2];
1721                 c.b = vc->vc_par[i + 3];
1722                 i += 3;
1723         } else
1724                 return i;
1725
1726         set_color(vc, &c);
1727
1728         return i;
1729 }
1730
1731 /* console_lock is held */
1732 static void csi_m(struct vc_data *vc)
1733 {
1734         int i;
1735
1736         for (i = 0; i <= vc->vc_npar; i++)
1737                 switch (vc->vc_par[i]) {
1738                 case 0: /* all attributes off */
1739                         default_attr(vc);
1740                         break;
1741                 case 1:
1742                         vc->state.intensity = VCI_BOLD;
1743                         break;
1744                 case 2:
1745                         vc->state.intensity = VCI_HALF_BRIGHT;
1746                         break;
1747                 case 3:
1748                         vc->state.italic = true;
1749                         break;
1750                 case 21:
1751                         /*
1752                          * No console drivers support double underline, so
1753                          * convert it to a single underline.
1754                          */
1755                 case 4:
1756                         vc->state.underline = true;
1757                         break;
1758                 case 5:
1759                         vc->state.blink = true;
1760                         break;
1761                 case 7:
1762                         vc->state.reverse = true;
1763                         break;
1764                 case 10: /* ANSI X3.64-1979 (SCO-ish?)
1765                           * Select primary font, don't display control chars if
1766                           * defined, don't set bit 8 on output.
1767                           */
1768                         vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset], vc);
1769                         vc->vc_disp_ctrl = 0;
1770                         vc->vc_toggle_meta = 0;
1771                         break;
1772                 case 11: /* ANSI X3.64-1979 (SCO-ish?)
1773                           * Select first alternate font, lets chars < 32 be
1774                           * displayed as ROM chars.
1775                           */
1776                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1777                         vc->vc_disp_ctrl = 1;
1778                         vc->vc_toggle_meta = 0;
1779                         break;
1780                 case 12: /* ANSI X3.64-1979 (SCO-ish?)
1781                           * Select second alternate font, toggle high bit
1782                           * before displaying as ROM char.
1783                           */
1784                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1785                         vc->vc_disp_ctrl = 1;
1786                         vc->vc_toggle_meta = 1;
1787                         break;
1788                 case 22:
1789                         vc->state.intensity = VCI_NORMAL;
1790                         break;
1791                 case 23:
1792                         vc->state.italic = false;
1793                         break;
1794                 case 24:
1795                         vc->state.underline = false;
1796                         break;
1797                 case 25:
1798                         vc->state.blink = false;
1799                         break;
1800                 case 27:
1801                         vc->state.reverse = false;
1802                         break;
1803                 case 38:
1804                         i = vc_t416_color(vc, i, rgb_foreground);
1805                         break;
1806                 case 48:
1807                         i = vc_t416_color(vc, i, rgb_background);
1808                         break;
1809                 case 39:
1810                         vc->state.color = (vc->vc_def_color & 0x0f) |
1811                                 (vc->state.color & 0xf0);
1812                         break;
1813                 case 49:
1814                         vc->state.color = (vc->vc_def_color & 0xf0) |
1815                                 (vc->state.color & 0x0f);
1816                         break;
1817                 default:
1818                         if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1819                                 if (vc->vc_par[i] < 100)
1820                                         vc->state.intensity = VCI_BOLD;
1821                                 vc->vc_par[i] -= 60;
1822                         }
1823                         if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1824                                 vc->state.color = color_table[vc->vc_par[i] - 30]
1825                                         | (vc->state.color & 0xf0);
1826                         else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1827                                 vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
1828                                         | (vc->state.color & 0x0f);
1829                         break;
1830                 }
1831         update_attr(vc);
1832 }
1833
1834 static void respond_string(const char *p, size_t len, struct tty_port *port)
1835 {
1836         tty_insert_flip_string(port, p, len);
1837         tty_flip_buffer_push(port);
1838 }
1839
1840 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1841 {
1842         char buf[40];
1843         int len;
1844
1845         len = sprintf(buf, "\033[%d;%dR", vc->state.y +
1846                         (vc->vc_decom ? vc->vc_top + 1 : 1),
1847                         vc->state.x + 1);
1848         respond_string(buf, len, tty->port);
1849 }
1850
1851 static inline void status_report(struct tty_struct *tty)
1852 {
1853         static const char teminal_ok[] = "\033[0n";
1854
1855         respond_string(teminal_ok, strlen(teminal_ok), tty->port);
1856 }
1857
1858 static inline void respond_ID(struct tty_struct *tty)
1859 {
1860         /* terminal answer to an ESC-Z or csi0c query. */
1861         static const char vt102_id[] = "\033[?6c";
1862
1863         respond_string(vt102_id, strlen(vt102_id), tty->port);
1864 }
1865
1866 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1867 {
1868         char buf[8];
1869         int len;
1870
1871         len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
1872                         (char)('!' + mrx), (char)('!' + mry));
1873         respond_string(buf, len, tty->port);
1874 }
1875
1876 /* invoked via ioctl(TIOCLINUX) and through set_selection_user */
1877 int mouse_reporting(void)
1878 {
1879         return vc_cons[fg_console].d->vc_report_mouse;
1880 }
1881
1882 /* console_lock is held */
1883 static void set_mode(struct vc_data *vc, int on_off)
1884 {
1885         int i;
1886
1887         for (i = 0; i <= vc->vc_npar; i++)
1888                 if (vc->vc_priv == EPdec) {
1889                         switch(vc->vc_par[i]) { /* DEC private modes set/reset */
1890                         case 1:                 /* Cursor keys send ^[Ox/^[[x */
1891                                 if (on_off)
1892                                         set_kbd(vc, decckm);
1893                                 else
1894                                         clr_kbd(vc, decckm);
1895                                 break;
1896                         case 3: /* 80/132 mode switch unimplemented */
1897 #if 0
1898                                 vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1899                                 /* this alone does not suffice; some user mode
1900                                    utility has to change the hardware regs */
1901 #endif
1902                                 break;
1903                         case 5:                 /* Inverted screen on/off */
1904                                 if (vc->vc_decscnm != on_off) {
1905                                         vc->vc_decscnm = on_off;
1906                                         invert_screen(vc, 0,
1907                                                         vc->vc_screenbuf_size,
1908                                                         false);
1909                                         update_attr(vc);
1910                                 }
1911                                 break;
1912                         case 6:                 /* Origin relative/absolute */
1913                                 vc->vc_decom = on_off;
1914                                 gotoxay(vc, 0, 0);
1915                                 break;
1916                         case 7:                 /* Autowrap on/off */
1917                                 vc->vc_decawm = on_off;
1918                                 break;
1919                         case 8:                 /* Autorepeat on/off */
1920                                 if (on_off)
1921                                         set_kbd(vc, decarm);
1922                                 else
1923                                         clr_kbd(vc, decarm);
1924                                 break;
1925                         case 9:
1926                                 vc->vc_report_mouse = on_off ? 1 : 0;
1927                                 break;
1928                         case 25:                /* Cursor on/off */
1929                                 vc->vc_deccm = on_off;
1930                                 break;
1931                         case 1000:
1932                                 vc->vc_report_mouse = on_off ? 2 : 0;
1933                                 break;
1934                         }
1935                 } else {
1936                         switch(vc->vc_par[i]) { /* ANSI modes set/reset */
1937                         case 3:                 /* Monitor (display ctrls) */
1938                                 vc->vc_disp_ctrl = on_off;
1939                                 break;
1940                         case 4:                 /* Insert Mode on/off */
1941                                 vc->vc_decim = on_off;
1942                                 break;
1943                         case 20:                /* Lf, Enter == CrLf/Lf */
1944                                 if (on_off)
1945                                         set_kbd(vc, lnm);
1946                                 else
1947                                         clr_kbd(vc, lnm);
1948                                 break;
1949                         }
1950                 }
1951 }
1952
1953 /* console_lock is held */
1954 static void setterm_command(struct vc_data *vc)
1955 {
1956         switch (vc->vc_par[0]) {
1957         case 1: /* set color for underline mode */
1958                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1959                         vc->vc_ulcolor = color_table[vc->vc_par[1]];
1960                         if (vc->state.underline)
1961                                 update_attr(vc);
1962                 }
1963                 break;
1964         case 2: /* set color for half intensity mode */
1965                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1966                         vc->vc_halfcolor = color_table[vc->vc_par[1]];
1967                         if (vc->state.intensity == VCI_HALF_BRIGHT)
1968                                 update_attr(vc);
1969                 }
1970                 break;
1971         case 8: /* store colors as defaults */
1972                 vc->vc_def_color = vc->vc_attr;
1973                 if (vc->vc_hi_font_mask == 0x100)
1974                         vc->vc_def_color >>= 1;
1975                 default_attr(vc);
1976                 update_attr(vc);
1977                 break;
1978         case 9: /* set blanking interval */
1979                 blankinterval = min(vc->vc_par[1], 60U) * 60;
1980                 poke_blanked_console();
1981                 break;
1982         case 10: /* set bell frequency in Hz */
1983                 if (vc->vc_npar >= 1)
1984                         vc->vc_bell_pitch = vc->vc_par[1];
1985                 else
1986                         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1987                 break;
1988         case 11: /* set bell duration in msec */
1989                 if (vc->vc_npar >= 1)
1990                         vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1991                                 msecs_to_jiffies(vc->vc_par[1]) : 0;
1992                 else
1993                         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1994                 break;
1995         case 12: /* bring specified console to the front */
1996                 if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1997                         set_console(vc->vc_par[1] - 1);
1998                 break;
1999         case 13: /* unblank the screen */
2000                 poke_blanked_console();
2001                 break;
2002         case 14: /* set vesa powerdown interval */
2003                 vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
2004                 break;
2005         case 15: /* activate the previous console */
2006                 set_console(last_console);
2007                 break;
2008         case 16: /* set cursor blink duration in msec */
2009                 if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
2010                                 vc->vc_par[1] <= USHRT_MAX)
2011                         vc->vc_cur_blink_ms = vc->vc_par[1];
2012                 else
2013                         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2014                 break;
2015         }
2016 }
2017
2018 /* console_lock is held */
2019 static void csi_at(struct vc_data *vc, unsigned int nr)
2020 {
2021         if (nr > vc->vc_cols - vc->state.x)
2022                 nr = vc->vc_cols - vc->state.x;
2023         else if (!nr)
2024                 nr = 1;
2025         insert_char(vc, nr);
2026 }
2027
2028 /* console_lock is held */
2029 static void csi_L(struct vc_data *vc, unsigned int nr)
2030 {
2031         if (nr > vc->vc_rows - vc->state.y)
2032                 nr = vc->vc_rows - vc->state.y;
2033         else if (!nr)
2034                 nr = 1;
2035         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
2036         vc->vc_need_wrap = 0;
2037 }
2038
2039 /* console_lock is held */
2040 static void csi_P(struct vc_data *vc, unsigned int nr)
2041 {
2042         if (nr > vc->vc_cols - vc->state.x)
2043                 nr = vc->vc_cols - vc->state.x;
2044         else if (!nr)
2045                 nr = 1;
2046         delete_char(vc, nr);
2047 }
2048
2049 /* console_lock is held */
2050 static void csi_M(struct vc_data *vc, unsigned int nr)
2051 {
2052         if (nr > vc->vc_rows - vc->state.y)
2053                 nr = vc->vc_rows - vc->state.y;
2054         else if (!nr)
2055                 nr=1;
2056         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
2057         vc->vc_need_wrap = 0;
2058 }
2059
2060 /* console_lock is held (except via vc_init->reset_terminal */
2061 static void save_cur(struct vc_data *vc)
2062 {
2063         memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
2064 }
2065
2066 /* console_lock is held */
2067 static void restore_cur(struct vc_data *vc)
2068 {
2069         memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
2070
2071         gotoxy(vc, vc->state.x, vc->state.y);
2072         vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
2073                         vc);
2074         update_attr(vc);
2075         vc->vc_need_wrap = 0;
2076 }
2077
2078 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2079         EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2080         ESpalette, ESosc, ESapc, ESpm, ESdcs };
2081
2082 /* console_lock is held (except via vc_init()) */
2083 static void reset_terminal(struct vc_data *vc, int do_clear)
2084 {
2085         unsigned int i;
2086
2087         vc->vc_top              = 0;
2088         vc->vc_bottom           = vc->vc_rows;
2089         vc->vc_state            = ESnormal;
2090         vc->vc_priv             = EPecma;
2091         vc->vc_translate        = set_translate(LAT1_MAP, vc);
2092         vc->state.Gx_charset[0] = LAT1_MAP;
2093         vc->state.Gx_charset[1] = GRAF_MAP;
2094         vc->state.charset       = 0;
2095         vc->vc_need_wrap        = 0;
2096         vc->vc_report_mouse     = 0;
2097         vc->vc_utf              = default_utf8;
2098         vc->vc_utf_count        = 0;
2099
2100         vc->vc_disp_ctrl        = 0;
2101         vc->vc_toggle_meta      = 0;
2102
2103         vc->vc_decscnm          = 0;
2104         vc->vc_decom            = 0;
2105         vc->vc_decawm           = 1;
2106         vc->vc_deccm            = global_cursor_default;
2107         vc->vc_decim            = 0;
2108
2109         vt_reset_keyboard(vc->vc_num);
2110
2111         vc->vc_cursor_type = cur_default;
2112         vc->vc_complement_mask = vc->vc_s_complement_mask;
2113
2114         default_attr(vc);
2115         update_attr(vc);
2116
2117         bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2118         for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
2119                 set_bit(i, vc->vc_tab_stop);
2120
2121         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2122         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2123         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2124
2125         gotoxy(vc, 0, 0);
2126         save_cur(vc);
2127         if (do_clear)
2128             csi_J(vc, 2);
2129 }
2130
2131 static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
2132 {
2133         unsigned char *charset = &vc->state.Gx_charset[which];
2134
2135         switch (c) {
2136         case '0':
2137                 *charset = GRAF_MAP;
2138                 break;
2139         case 'B':
2140                 *charset = LAT1_MAP;
2141                 break;
2142         case 'U':
2143                 *charset = IBMPC_MAP;
2144                 break;
2145         case 'K':
2146                 *charset = USER_MAP;
2147                 break;
2148         }
2149
2150         if (vc->state.charset == which)
2151                 vc->vc_translate = set_translate(*charset, vc);
2152 }
2153
2154 /* is this state an ANSI control string? */
2155 static bool ansi_control_string(unsigned int state)
2156 {
2157         if (state == ESosc || state == ESapc || state == ESpm || state == ESdcs)
2158                 return true;
2159         return false;
2160 }
2161
2162 /* console_lock is held */
2163 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2164 {
2165         /*
2166          *  Control characters can be used in the _middle_
2167          *  of an escape sequence, aside from ANSI control strings.
2168          */
2169         if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
2170                 return;
2171         switch (c) {
2172         case 0:
2173                 return;
2174         case 7:
2175                 if (ansi_control_string(vc->vc_state))
2176                         vc->vc_state = ESnormal;
2177                 else if (vc->vc_bell_duration)
2178                         kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2179                 return;
2180         case 8:
2181                 bs(vc);
2182                 return;
2183         case 9:
2184                 vc->vc_pos -= (vc->state.x << 1);
2185
2186                 vc->state.x = find_next_bit(vc->vc_tab_stop,
2187                                 min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2188                                 vc->state.x + 1);
2189                 if (vc->state.x >= VC_TABSTOPS_COUNT)
2190                         vc->state.x = vc->vc_cols - 1;
2191
2192                 vc->vc_pos += (vc->state.x << 1);
2193                 notify_write(vc, '\t');
2194                 return;
2195         case 10: case 11: case 12:
2196                 lf(vc);
2197                 if (!is_kbd(vc, lnm))
2198                         return;
2199                 fallthrough;
2200         case 13:
2201                 cr(vc);
2202                 return;
2203         case 14:
2204                 vc->state.charset = 1;
2205                 vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2206                 vc->vc_disp_ctrl = 1;
2207                 return;
2208         case 15:
2209                 vc->state.charset = 0;
2210                 vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2211                 vc->vc_disp_ctrl = 0;
2212                 return;
2213         case 24: case 26:
2214                 vc->vc_state = ESnormal;
2215                 return;
2216         case 27:
2217                 vc->vc_state = ESesc;
2218                 return;
2219         case 127:
2220                 del(vc);
2221                 return;
2222         case 128+27:
2223                 vc->vc_state = ESsquare;
2224                 return;
2225         }
2226         switch(vc->vc_state) {
2227         case ESesc:
2228                 vc->vc_state = ESnormal;
2229                 switch (c) {
2230                 case '[':
2231                         vc->vc_state = ESsquare;
2232                         return;
2233                 case ']':
2234                         vc->vc_state = ESnonstd;
2235                         return;
2236                 case '_':
2237                         vc->vc_state = ESapc;
2238                         return;
2239                 case '^':
2240                         vc->vc_state = ESpm;
2241                         return;
2242                 case '%':
2243                         vc->vc_state = ESpercent;
2244                         return;
2245                 case 'E':
2246                         cr(vc);
2247                         lf(vc);
2248                         return;
2249                 case 'M':
2250                         ri(vc);
2251                         return;
2252                 case 'D':
2253                         lf(vc);
2254                         return;
2255                 case 'H':
2256                         if (vc->state.x < VC_TABSTOPS_COUNT)
2257                                 set_bit(vc->state.x, vc->vc_tab_stop);
2258                         return;
2259                 case 'P':
2260                         vc->vc_state = ESdcs;
2261                         return;
2262                 case 'Z':
2263                         respond_ID(tty);
2264                         return;
2265                 case '7':
2266                         save_cur(vc);
2267                         return;
2268                 case '8':
2269                         restore_cur(vc);
2270                         return;
2271                 case '(':
2272                         vc->vc_state = ESsetG0;
2273                         return;
2274                 case ')':
2275                         vc->vc_state = ESsetG1;
2276                         return;
2277                 case '#':
2278                         vc->vc_state = EShash;
2279                         return;
2280                 case 'c':
2281                         reset_terminal(vc, 1);
2282                         return;
2283                 case '>':  /* Numeric keypad */
2284                         clr_kbd(vc, kbdapplic);
2285                         return;
2286                 case '=':  /* Appl. keypad */
2287                         set_kbd(vc, kbdapplic);
2288                         return;
2289                 }
2290                 return;
2291         case ESnonstd:
2292                 if (c=='P') {   /* palette escape sequence */
2293                         for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2294                                 vc->vc_par[vc->vc_npar] = 0;
2295                         vc->vc_npar = 0;
2296                         vc->vc_state = ESpalette;
2297                         return;
2298                 } else if (c=='R') {   /* reset palette */
2299                         reset_palette(vc);
2300                         vc->vc_state = ESnormal;
2301                 } else if (c>='0' && c<='9')
2302                         vc->vc_state = ESosc;
2303                 else
2304                         vc->vc_state = ESnormal;
2305                 return;
2306         case ESpalette:
2307                 if (isxdigit(c)) {
2308                         vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2309                         if (vc->vc_npar == 7) {
2310                                 int i = vc->vc_par[0] * 3, j = 1;
2311                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2312                                 vc->vc_palette[i++] += vc->vc_par[j++];
2313                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2314                                 vc->vc_palette[i++] += vc->vc_par[j++];
2315                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2316                                 vc->vc_palette[i] += vc->vc_par[j];
2317                                 set_palette(vc);
2318                                 vc->vc_state = ESnormal;
2319                         }
2320                 } else
2321                         vc->vc_state = ESnormal;
2322                 return;
2323         case ESsquare:
2324                 for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2325                         vc->vc_par[vc->vc_npar] = 0;
2326                 vc->vc_npar = 0;
2327                 vc->vc_state = ESgetpars;
2328                 if (c == '[') { /* Function key */
2329                         vc->vc_state=ESfunckey;
2330                         return;
2331                 }
2332                 switch (c) {
2333                 case '?':
2334                         vc->vc_priv = EPdec;
2335                         return;
2336                 case '>':
2337                         vc->vc_priv = EPgt;
2338                         return;
2339                 case '=':
2340                         vc->vc_priv = EPeq;
2341                         return;
2342                 case '<':
2343                         vc->vc_priv = EPlt;
2344                         return;
2345                 }
2346                 vc->vc_priv = EPecma;
2347                 fallthrough;
2348         case ESgetpars:
2349                 if (c == ';' && vc->vc_npar < NPAR - 1) {
2350                         vc->vc_npar++;
2351                         return;
2352                 } else if (c>='0' && c<='9') {
2353                         vc->vc_par[vc->vc_npar] *= 10;
2354                         vc->vc_par[vc->vc_npar] += c - '0';
2355                         return;
2356                 }
2357                 if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2358                         vc->vc_state = EScsiignore;
2359                         return;
2360                 }
2361                 vc->vc_state = ESnormal;
2362                 switch(c) {
2363                 case 'h':
2364                         if (vc->vc_priv <= EPdec)
2365                                 set_mode(vc, 1);
2366                         return;
2367                 case 'l':
2368                         if (vc->vc_priv <= EPdec)
2369                                 set_mode(vc, 0);
2370                         return;
2371                 case 'c':
2372                         if (vc->vc_priv == EPdec) {
2373                                 if (vc->vc_par[0])
2374                                         vc->vc_cursor_type =
2375                                                 CUR_MAKE(vc->vc_par[0],
2376                                                          vc->vc_par[1],
2377                                                          vc->vc_par[2]);
2378                                 else
2379                                         vc->vc_cursor_type = cur_default;
2380                                 return;
2381                         }
2382                         break;
2383                 case 'm':
2384                         if (vc->vc_priv == EPdec) {
2385                                 clear_selection();
2386                                 if (vc->vc_par[0])
2387                                         vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2388                                 else
2389                                         vc->vc_complement_mask = vc->vc_s_complement_mask;
2390                                 return;
2391                         }
2392                         break;
2393                 case 'n':
2394                         if (vc->vc_priv == EPecma) {
2395                                 if (vc->vc_par[0] == 5)
2396                                         status_report(tty);
2397                                 else if (vc->vc_par[0] == 6)
2398                                         cursor_report(vc, tty);
2399                         }
2400                         return;
2401                 }
2402                 if (vc->vc_priv != EPecma) {
2403                         vc->vc_priv = EPecma;
2404                         return;
2405                 }
2406                 switch(c) {
2407                 case 'G': case '`':
2408                         if (vc->vc_par[0])
2409                                 vc->vc_par[0]--;
2410                         gotoxy(vc, vc->vc_par[0], vc->state.y);
2411                         return;
2412                 case 'A':
2413                         if (!vc->vc_par[0])
2414                                 vc->vc_par[0]++;
2415                         gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2416                         return;
2417                 case 'B': case 'e':
2418                         if (!vc->vc_par[0])
2419                                 vc->vc_par[0]++;
2420                         gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2421                         return;
2422                 case 'C': case 'a':
2423                         if (!vc->vc_par[0])
2424                                 vc->vc_par[0]++;
2425                         gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2426                         return;
2427                 case 'D':
2428                         if (!vc->vc_par[0])
2429                                 vc->vc_par[0]++;
2430                         gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2431                         return;
2432                 case 'E':
2433                         if (!vc->vc_par[0])
2434                                 vc->vc_par[0]++;
2435                         gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2436                         return;
2437                 case 'F':
2438                         if (!vc->vc_par[0])
2439                                 vc->vc_par[0]++;
2440                         gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2441                         return;
2442                 case 'd':
2443                         if (vc->vc_par[0])
2444                                 vc->vc_par[0]--;
2445                         gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2446                         return;
2447                 case 'H': case 'f':
2448                         if (vc->vc_par[0])
2449                                 vc->vc_par[0]--;
2450                         if (vc->vc_par[1])
2451                                 vc->vc_par[1]--;
2452                         gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2453                         return;
2454                 case 'J':
2455                         csi_J(vc, vc->vc_par[0]);
2456                         return;
2457                 case 'K':
2458                         csi_K(vc, vc->vc_par[0]);
2459                         return;
2460                 case 'L':
2461                         csi_L(vc, vc->vc_par[0]);
2462                         return;
2463                 case 'M':
2464                         csi_M(vc, vc->vc_par[0]);
2465                         return;
2466                 case 'P':
2467                         csi_P(vc, vc->vc_par[0]);
2468                         return;
2469                 case 'c':
2470                         if (!vc->vc_par[0])
2471                                 respond_ID(tty);
2472                         return;
2473                 case 'g':
2474                         if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2475                                 set_bit(vc->state.x, vc->vc_tab_stop);
2476                         else if (vc->vc_par[0] == 3)
2477                                 bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2478                         return;
2479                 case 'm':
2480                         csi_m(vc);
2481                         return;
2482                 case 'q': /* DECLL - but only 3 leds */
2483                         /* map 0,1,2,3 to 0,1,2,4 */
2484                         if (vc->vc_par[0] < 4)
2485                                 vt_set_led_state(vc->vc_num,
2486                                             (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2487                         return;
2488                 case 'r':
2489                         if (!vc->vc_par[0])
2490                                 vc->vc_par[0]++;
2491                         if (!vc->vc_par[1])
2492                                 vc->vc_par[1] = vc->vc_rows;
2493                         /* Minimum allowed region is 2 lines */
2494                         if (vc->vc_par[0] < vc->vc_par[1] &&
2495                             vc->vc_par[1] <= vc->vc_rows) {
2496                                 vc->vc_top = vc->vc_par[0] - 1;
2497                                 vc->vc_bottom = vc->vc_par[1];
2498                                 gotoxay(vc, 0, 0);
2499                         }
2500                         return;
2501                 case 's':
2502                         save_cur(vc);
2503                         return;
2504                 case 'u':
2505                         restore_cur(vc);
2506                         return;
2507                 case 'X':
2508                         csi_X(vc, vc->vc_par[0]);
2509                         return;
2510                 case '@':
2511                         csi_at(vc, vc->vc_par[0]);
2512                         return;
2513                 case ']': /* setterm functions */
2514                         setterm_command(vc);
2515                         return;
2516                 }
2517                 return;
2518         case EScsiignore:
2519                 if (c >= 0x20 && c <= 0x3f)
2520                         return;
2521                 vc->vc_state = ESnormal;
2522                 return;
2523         case ESpercent:
2524                 vc->vc_state = ESnormal;
2525                 switch (c) {
2526                 case '@':  /* defined in ISO 2022 */
2527                         vc->vc_utf = 0;
2528                         return;
2529                 case 'G':  /* prelim official escape code */
2530                 case '8':  /* retained for compatibility */
2531                         vc->vc_utf = 1;
2532                         return;
2533                 }
2534                 return;
2535         case ESfunckey:
2536                 vc->vc_state = ESnormal;
2537                 return;
2538         case EShash:
2539                 vc->vc_state = ESnormal;
2540                 if (c == '8') {
2541                         /* DEC screen alignment test. kludge :-) */
2542                         vc->vc_video_erase_char =
2543                                 (vc->vc_video_erase_char & 0xff00) | 'E';
2544                         csi_J(vc, 2);
2545                         vc->vc_video_erase_char =
2546                                 (vc->vc_video_erase_char & 0xff00) | ' ';
2547                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2548                 }
2549                 return;
2550         case ESsetG0:
2551                 vc_setGx(vc, 0, c);
2552                 vc->vc_state = ESnormal;
2553                 return;
2554         case ESsetG1:
2555                 vc_setGx(vc, 1, c);
2556                 vc->vc_state = ESnormal;
2557                 return;
2558         case ESapc:
2559                 return;
2560         case ESosc:
2561                 return;
2562         case ESpm:
2563                 return;
2564         case ESdcs:
2565                 return;
2566         default:
2567                 vc->vc_state = ESnormal;
2568         }
2569 }
2570
2571 /* is_double_width() is based on the wcwidth() implementation by
2572  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2573  * Latest version: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2574  */
2575 struct interval {
2576         uint32_t first;
2577         uint32_t last;
2578 };
2579
2580 static int ucs_cmp(const void *key, const void *elt)
2581 {
2582         uint32_t ucs = *(uint32_t *)key;
2583         struct interval e = *(struct interval *) elt;
2584
2585         if (ucs > e.last)
2586                 return 1;
2587         else if (ucs < e.first)
2588                 return -1;
2589         return 0;
2590 }
2591
2592 static int is_double_width(uint32_t ucs)
2593 {
2594         static const struct interval double_width[] = {
2595                 { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2596                 { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2597                 { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2598                 { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2599         };
2600         if (ucs < double_width[0].first ||
2601             ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2602                 return 0;
2603
2604         return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2605                         sizeof(struct interval), ucs_cmp) != NULL;
2606 }
2607
2608 struct vc_draw_region {
2609         unsigned long from, to;
2610         int x;
2611 };
2612
2613 static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
2614 {
2615         if (draw->x < 0)
2616                 return;
2617
2618         vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
2619                         (u16 *)draw->to - (u16 *)draw->from, vc->state.y,
2620                         draw->x);
2621         draw->x = -1;
2622 }
2623
2624 static inline int vc_translate_ascii(const struct vc_data *vc, int c)
2625 {
2626         if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
2627                 if (vc->vc_toggle_meta)
2628                         c |= 0x80;
2629
2630                 return vc->vc_translate[c];
2631         }
2632
2633         return c;
2634 }
2635
2636
2637 /**
2638  * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
2639  * @c: the received character, or U+FFFD for invalid sequences.
2640  */
2641 static inline int vc_sanitize_unicode(const int c)
2642 {
2643         if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2644                 return 0xfffd;
2645
2646         return c;
2647 }
2648
2649 /**
2650  * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
2651  * @vc: virtual console
2652  * @c: character to translate
2653  * @rescan: we return true if we need more (continuation) data
2654  *
2655  * @vc_utf_char is the being-constructed unicode character.
2656  * @vc_utf_count is the number of continuation bytes still expected to arrive.
2657  * @vc_npar is the number of continuation bytes arrived so far.
2658  */
2659 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
2660 {
2661         static const u32 utf8_length_changes[] = {
2662                 0x0000007f, 0x000007ff, 0x0000ffff,
2663                 0x001fffff, 0x03ffffff, 0x7fffffff
2664         };
2665
2666         /* Continuation byte received */
2667         if ((c & 0xc0) == 0x80) {
2668                 /* Unexpected continuation byte? */
2669                 if (!vc->vc_utf_count)
2670                         return 0xfffd;
2671
2672                 vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2673                 vc->vc_npar++;
2674                 if (--vc->vc_utf_count)
2675                         goto need_more_bytes;
2676
2677                 /* Got a whole character */
2678                 c = vc->vc_utf_char;
2679                 /* Reject overlong sequences */
2680                 if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2681                                 c > utf8_length_changes[vc->vc_npar])
2682                         return 0xfffd;
2683
2684                 return vc_sanitize_unicode(c);
2685         }
2686
2687         /* Single ASCII byte or first byte of a sequence received */
2688         if (vc->vc_utf_count) {
2689                 /* Continuation byte expected */
2690                 *rescan = true;
2691                 vc->vc_utf_count = 0;
2692                 return 0xfffd;
2693         }
2694
2695         /* Nothing to do if an ASCII byte was received */
2696         if (c <= 0x7f)
2697                 return c;
2698
2699         /* First byte of a multibyte sequence received */
2700         vc->vc_npar = 0;
2701         if ((c & 0xe0) == 0xc0) {
2702                 vc->vc_utf_count = 1;
2703                 vc->vc_utf_char = (c & 0x1f);
2704         } else if ((c & 0xf0) == 0xe0) {
2705                 vc->vc_utf_count = 2;
2706                 vc->vc_utf_char = (c & 0x0f);
2707         } else if ((c & 0xf8) == 0xf0) {
2708                 vc->vc_utf_count = 3;
2709                 vc->vc_utf_char = (c & 0x07);
2710         } else if ((c & 0xfc) == 0xf8) {
2711                 vc->vc_utf_count = 4;
2712                 vc->vc_utf_char = (c & 0x03);
2713         } else if ((c & 0xfe) == 0xfc) {
2714                 vc->vc_utf_count = 5;
2715                 vc->vc_utf_char = (c & 0x01);
2716         } else {
2717                 /* 254 and 255 are invalid */
2718                 return 0xfffd;
2719         }
2720
2721 need_more_bytes:
2722         return -1;
2723 }
2724
2725 static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
2726 {
2727         /* Do no translation at all in control states */
2728         if (vc->vc_state != ESnormal)
2729                 return *c;
2730
2731         if (vc->vc_utf && !vc->vc_disp_ctrl)
2732                 return *c = vc_translate_unicode(vc, *c, rescan);
2733
2734         /* no utf or alternate charset mode */
2735         return vc_translate_ascii(vc, *c);
2736 }
2737
2738 static inline unsigned char vc_invert_attr(const struct vc_data *vc)
2739 {
2740         if (!vc->vc_can_do_color)
2741                 return vc->vc_attr ^ 0x08;
2742
2743         if (vc->vc_hi_font_mask == 0x100)
2744                 return   (vc->vc_attr & 0x11) |
2745                         ((vc->vc_attr & 0xe0) >> 4) |
2746                         ((vc->vc_attr & 0x0e) << 4);
2747
2748         return   (vc->vc_attr & 0x88) |
2749                 ((vc->vc_attr & 0x70) >> 4) |
2750                 ((vc->vc_attr & 0x07) << 4);
2751 }
2752
2753 static bool vc_is_control(struct vc_data *vc, int tc, int c)
2754 {
2755         /*
2756          * A bitmap for codes <32. A bit of 1 indicates that the code
2757          * corresponding to that bit number invokes some special action (such
2758          * as cursor movement) and should not be displayed as a glyph unless
2759          * the disp_ctrl mode is explicitly enabled.
2760          */
2761         static const u32 CTRL_ACTION = 0x0d00ff81;
2762         /* Cannot be overridden by disp_ctrl */
2763         static const u32 CTRL_ALWAYS = 0x0800f501;
2764
2765         if (vc->vc_state != ESnormal)
2766                 return true;
2767
2768         if (!tc)
2769                 return true;
2770
2771         /*
2772          * If the original code was a control character we only allow a glyph
2773          * to be displayed if the code is not normally used (such as for cursor
2774          * movement) or if the disp_ctrl mode has been explicitly enabled.
2775          * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
2776          * displayed as control characters, as the console would be pretty
2777          * useless without them; to display an arbitrary font position use the
2778          * direct-to-font zone in UTF-8 mode.
2779          */
2780         if (c < 32) {
2781                 if (vc->vc_disp_ctrl)
2782                         return CTRL_ALWAYS & BIT(c);
2783                 else
2784                         return vc->vc_utf || (CTRL_ACTION & BIT(c));
2785         }
2786
2787         if (c == 127 && !vc->vc_disp_ctrl)
2788                 return true;
2789
2790         if (c == 128 + 27)
2791                 return true;
2792
2793         return false;
2794 }
2795
2796 static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
2797                 struct vc_draw_region *draw)
2798 {
2799         int next_c;
2800         unsigned char vc_attr = vc->vc_attr;
2801         u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
2802         u8 width = 1;
2803         bool inverse = false;
2804
2805         if (vc->vc_utf && !vc->vc_disp_ctrl) {
2806                 if (is_double_width(c))
2807                         width = 2;
2808         }
2809
2810         /* Now try to find out how to display it */
2811         tc = conv_uni_to_pc(vc, tc);
2812         if (tc & ~charmask) {
2813                 if (tc == -1 || tc == -2)
2814                         return -1; /* nothing to display */
2815
2816                 /* Glyph not found */
2817                 if ((!vc->vc_utf || vc->vc_disp_ctrl || c < 128) &&
2818                                 !(c & ~charmask)) {
2819                         /*
2820                          * In legacy mode use the glyph we get by a 1:1
2821                          * mapping.
2822                          * This would make absolutely no sense with Unicode in
2823                          * mind, but do this for ASCII characters since a font
2824                          * may lack Unicode mapping info and we don't want to
2825                          * end up with having question marks only.
2826                          */
2827                         tc = c;
2828                 } else {
2829                         /*
2830                          * Display U+FFFD. If it's not found, display an inverse
2831                          * question mark.
2832                          */
2833                         tc = conv_uni_to_pc(vc, 0xfffd);
2834                         if (tc < 0) {
2835                                 inverse = true;
2836                                 tc = conv_uni_to_pc(vc, '?');
2837                                 if (tc < 0)
2838                                         tc = '?';
2839
2840                                 vc_attr = vc_invert_attr(vc);
2841                                 con_flush(vc, draw);
2842                         }
2843                 }
2844         }
2845
2846         next_c = c;
2847         while (1) {
2848                 if (vc->vc_need_wrap || vc->vc_decim)
2849                         con_flush(vc, draw);
2850                 if (vc->vc_need_wrap) {
2851                         cr(vc);
2852                         lf(vc);
2853                 }
2854                 if (vc->vc_decim)
2855                         insert_char(vc, 1);
2856                 vc_uniscr_putc(vc, next_c);
2857
2858                 if (himask)
2859                         tc = ((tc & 0x100) ? himask : 0) |
2860                               (tc &  0xff);
2861                 tc |= (vc_attr << 8) & ~himask;
2862
2863                 scr_writew(tc, (u16 *)vc->vc_pos);
2864
2865                 if (con_should_update(vc) && draw->x < 0) {
2866                         draw->x = vc->state.x;
2867                         draw->from = vc->vc_pos;
2868                 }
2869                 if (vc->state.x == vc->vc_cols - 1) {
2870                         vc->vc_need_wrap = vc->vc_decawm;
2871                         draw->to = vc->vc_pos + 2;
2872                 } else {
2873                         vc->state.x++;
2874                         draw->to = (vc->vc_pos += 2);
2875                 }
2876
2877                 if (!--width)
2878                         break;
2879
2880                 /* A space is printed in the second column */
2881                 tc = conv_uni_to_pc(vc, ' ');
2882                 if (tc < 0)
2883                         tc = ' ';
2884                 next_c = ' ';
2885         }
2886         notify_write(vc, c);
2887
2888         if (inverse)
2889                 con_flush(vc, draw);
2890
2891         return 0;
2892 }
2893
2894 /* acquires console_lock */
2895 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2896 {
2897         struct vc_draw_region draw = {
2898                 .x = -1,
2899         };
2900         int c, tc, n = 0;
2901         unsigned int currcons;
2902         struct vc_data *vc;
2903         struct vt_notifier_param param;
2904         bool rescan;
2905
2906         if (in_interrupt())
2907                 return count;
2908
2909         console_lock();
2910         vc = tty->driver_data;
2911         if (vc == NULL) {
2912                 pr_err("vt: argh, driver_data is NULL !\n");
2913                 console_unlock();
2914                 return 0;
2915         }
2916
2917         currcons = vc->vc_num;
2918         if (!vc_cons_allocated(currcons)) {
2919                 /* could this happen? */
2920                 pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2921                 console_unlock();
2922                 return 0;
2923         }
2924
2925
2926         /* undraw cursor first */
2927         if (con_is_fg(vc))
2928                 hide_cursor(vc);
2929
2930         param.vc = vc;
2931
2932         while (!tty->stopped && count) {
2933                 int orig = *buf;
2934                 buf++;
2935                 n++;
2936                 count--;
2937 rescan_last_byte:
2938                 c = orig;
2939                 rescan = false;
2940
2941                 tc = vc_translate(vc, &c, &rescan);
2942                 if (tc == -1)
2943                         continue;
2944
2945                 param.c = tc;
2946                 if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2947                                         &param) == NOTIFY_STOP)
2948                         continue;
2949
2950                 if (vc_is_control(vc, tc, c)) {
2951                         con_flush(vc, &draw);
2952                         do_con_trol(tty, vc, orig);
2953                         continue;
2954                 }
2955
2956                 if (vc_con_write_normal(vc, tc, c, &draw) < 0)
2957                         continue;
2958
2959                 if (rescan)
2960                         goto rescan_last_byte;
2961         }
2962         con_flush(vc, &draw);
2963         vc_uniscr_debug_check(vc);
2964         console_conditional_schedule();
2965         notify_update(vc);
2966         console_unlock();
2967         return n;
2968 }
2969
2970 /*
2971  * This is the console switching callback.
2972  *
2973  * Doing console switching in a process context allows
2974  * us to do the switches asynchronously (needed when we want
2975  * to switch due to a keyboard interrupt).  Synchronization
2976  * with other console code and prevention of re-entrancy is
2977  * ensured with console_lock.
2978  */
2979 static void console_callback(struct work_struct *ignored)
2980 {
2981         console_lock();
2982
2983         if (want_console >= 0) {
2984                 if (want_console != fg_console &&
2985                     vc_cons_allocated(want_console)) {
2986                         hide_cursor(vc_cons[fg_console].d);
2987                         change_console(vc_cons[want_console].d);
2988                         /* we only changed when the console had already
2989                            been allocated - a new console is not created
2990                            in an interrupt routine */
2991                 }
2992                 want_console = -1;
2993         }
2994         if (do_poke_blanked_console) { /* do not unblank for a LED change */
2995                 do_poke_blanked_console = 0;
2996                 poke_blanked_console();
2997         }
2998         if (scrollback_delta) {
2999                 struct vc_data *vc = vc_cons[fg_console].d;
3000                 clear_selection();
3001                 if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
3002                         vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
3003                 scrollback_delta = 0;
3004         }
3005         if (blank_timer_expired) {
3006                 do_blank_screen(0);
3007                 blank_timer_expired = 0;
3008         }
3009         notify_update(vc_cons[fg_console].d);
3010
3011         console_unlock();
3012 }
3013
3014 int set_console(int nr)
3015 {
3016         struct vc_data *vc = vc_cons[fg_console].d;
3017
3018         if (!vc_cons_allocated(nr) || vt_dont_switch ||
3019                 (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
3020
3021                 /*
3022                  * Console switch will fail in console_callback() or
3023                  * change_console() so there is no point scheduling
3024                  * the callback
3025                  *
3026                  * Existing set_console() users don't check the return
3027                  * value so this shouldn't break anything
3028                  */
3029                 return -EINVAL;
3030         }
3031
3032         want_console = nr;
3033         schedule_console_callback();
3034
3035         return 0;
3036 }
3037
3038 struct tty_driver *console_driver;
3039
3040 #ifdef CONFIG_VT_CONSOLE
3041
3042 /**
3043  * vt_kmsg_redirect() - Sets/gets the kernel message console
3044  * @new:        The new virtual terminal number or -1 if the console should stay
3045  *              unchanged
3046  *
3047  * By default, the kernel messages are always printed on the current virtual
3048  * console. However, the user may modify that default with the
3049  * TIOCL_SETKMSGREDIRECT ioctl call.
3050  *
3051  * This function sets the kernel message console to be @new. It returns the old
3052  * virtual console number. The virtual terminal number 0 (both as parameter and
3053  * return value) means no redirection (i.e. always printed on the currently
3054  * active console).
3055  *
3056  * The parameter -1 means that only the current console is returned, but the
3057  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
3058  * case to make the code more understandable.
3059  *
3060  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
3061  * the parameter and always returns 0.
3062  */
3063 int vt_kmsg_redirect(int new)
3064 {
3065         static int kmsg_con;
3066
3067         if (new != -1)
3068                 return xchg(&kmsg_con, new);
3069         else
3070                 return kmsg_con;
3071 }
3072
3073 /*
3074  *      Console on virtual terminal
3075  *
3076  * The console must be locked when we get here.
3077  */
3078
3079 static void vt_console_print(struct console *co, const char *b, unsigned count)
3080 {
3081         struct vc_data *vc = vc_cons[fg_console].d;
3082         unsigned char c;
3083         static DEFINE_SPINLOCK(printing_lock);
3084         const ushort *start;
3085         ushort start_x, cnt;
3086         int kmsg_console;
3087
3088         /* console busy or not yet initialized */
3089         if (!printable)
3090                 return;
3091         if (!spin_trylock(&printing_lock))
3092                 return;
3093
3094         kmsg_console = vt_get_kmsg_redirect();
3095         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
3096                 vc = vc_cons[kmsg_console - 1].d;
3097
3098         if (!vc_cons_allocated(fg_console)) {
3099                 /* impossible */
3100                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
3101                 goto quit;
3102         }
3103
3104         if (vc->vc_mode != KD_TEXT)
3105                 goto quit;
3106
3107         /* undraw cursor first */
3108         if (con_is_fg(vc))
3109                 hide_cursor(vc);
3110
3111         start = (ushort *)vc->vc_pos;
3112         start_x = vc->state.x;
3113         cnt = 0;
3114         while (count--) {
3115                 c = *b++;
3116                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
3117                         if (cnt && con_is_visible(vc))
3118                                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3119                         cnt = 0;
3120                         if (c == 8) {           /* backspace */
3121                                 bs(vc);
3122                                 start = (ushort *)vc->vc_pos;
3123                                 start_x = vc->state.x;
3124                                 continue;
3125                         }
3126                         if (c != 13)
3127                                 lf(vc);
3128                         cr(vc);
3129                         start = (ushort *)vc->vc_pos;
3130                         start_x = vc->state.x;
3131                         if (c == 10 || c == 13)
3132                                 continue;
3133                 }
3134                 vc_uniscr_putc(vc, c);
3135                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3136                 notify_write(vc, c);
3137                 cnt++;
3138                 if (vc->state.x == vc->vc_cols - 1) {
3139                         vc->vc_need_wrap = 1;
3140                 } else {
3141                         vc->vc_pos += 2;
3142                         vc->state.x++;
3143                 }
3144         }
3145         if (cnt && con_is_visible(vc))
3146                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3147         set_cursor(vc);
3148         notify_update(vc);
3149
3150 quit:
3151         spin_unlock(&printing_lock);
3152 }
3153
3154 static struct tty_driver *vt_console_device(struct console *c, int *index)
3155 {
3156         *index = c->index ? c->index-1 : fg_console;
3157         return console_driver;
3158 }
3159
3160 static struct console vt_console_driver = {
3161         .name           = "tty",
3162         .write          = vt_console_print,
3163         .device         = vt_console_device,
3164         .unblank        = unblank_screen,
3165         .flags          = CON_PRINTBUFFER,
3166         .index          = -1,
3167 };
3168 #endif
3169
3170 /*
3171  *      Handling of Linux-specific VC ioctls
3172  */
3173
3174 /*
3175  * Generally a bit racy with respect to console_lock();.
3176  *
3177  * There are some functions which don't need it.
3178  *
3179  * There are some functions which can sleep for arbitrary periods
3180  * (paste_selection) but we don't need the lock there anyway.
3181  *
3182  * set_selection_user has locking, and definitely needs it
3183  */
3184
3185 int tioclinux(struct tty_struct *tty, unsigned long arg)
3186 {
3187         char type, data;
3188         char __user *p = (char __user *)arg;
3189         int lines;
3190         int ret;
3191
3192         if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3193                 return -EPERM;
3194         if (get_user(type, p))
3195                 return -EFAULT;
3196         ret = 0;
3197
3198         switch (type)
3199         {
3200                 case TIOCL_SETSEL:
3201                         ret = set_selection_user((struct tiocl_selection
3202                                                  __user *)(p+1), tty);
3203                         break;
3204                 case TIOCL_PASTESEL:
3205                         ret = paste_selection(tty);
3206                         break;
3207                 case TIOCL_UNBLANKSCREEN:
3208                         console_lock();
3209                         unblank_screen();
3210                         console_unlock();
3211                         break;
3212                 case TIOCL_SELLOADLUT:
3213                         console_lock();
3214                         ret = sel_loadlut(p);
3215                         console_unlock();
3216                         break;
3217                 case TIOCL_GETSHIFTSTATE:
3218
3219         /*
3220          * Make it possible to react to Shift+Mousebutton.
3221          * Note that 'shift_state' is an undocumented
3222          * kernel-internal variable; programs not closely
3223          * related to the kernel should not use this.
3224          */
3225                         data = vt_get_shift_state();
3226                         ret = put_user(data, p);
3227                         break;
3228                 case TIOCL_GETMOUSEREPORTING:
3229                         console_lock(); /* May be overkill */
3230                         data = mouse_reporting();
3231                         console_unlock();
3232                         ret = put_user(data, p);
3233                         break;
3234                 case TIOCL_SETVESABLANK:
3235                         console_lock();
3236                         ret = set_vesa_blanking(p);
3237                         console_unlock();
3238                         break;
3239                 case TIOCL_GETKMSGREDIRECT:
3240                         data = vt_get_kmsg_redirect();
3241                         ret = put_user(data, p);
3242                         break;
3243                 case TIOCL_SETKMSGREDIRECT:
3244                         if (!capable(CAP_SYS_ADMIN)) {
3245                                 ret = -EPERM;
3246                         } else {
3247                                 if (get_user(data, p+1))
3248                                         ret = -EFAULT;
3249                                 else
3250                                         vt_kmsg_redirect(data);
3251                         }
3252                         break;
3253                 case TIOCL_GETFGCONSOLE:
3254                         /* No locking needed as this is a transiently
3255                            correct return anyway if the caller hasn't
3256                            disabled switching */
3257                         ret = fg_console;
3258                         break;
3259                 case TIOCL_SCROLLCONSOLE:
3260                         if (get_user(lines, (s32 __user *)(p+4))) {
3261                                 ret = -EFAULT;
3262                         } else {
3263                                 /* Need the console lock here. Note that lots
3264                                    of other calls need fixing before the lock
3265                                    is actually useful ! */
3266                                 console_lock();
3267                                 scrollfront(vc_cons[fg_console].d, lines);
3268                                 console_unlock();
3269                                 ret = 0;
3270                         }
3271                         break;
3272                 case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
3273                         console_lock();
3274                         ignore_poke = 1;
3275                         do_blank_screen(0);
3276                         console_unlock();
3277                         break;
3278                 case TIOCL_BLANKEDSCREEN:
3279                         ret = console_blanked;
3280                         break;
3281                 default:
3282                         ret = -EINVAL;
3283                         break;
3284         }
3285         return ret;
3286 }
3287
3288 /*
3289  * /dev/ttyN handling
3290  */
3291
3292 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3293 {
3294         int     retval;
3295
3296         retval = do_con_write(tty, buf, count);
3297         con_flush_chars(tty);
3298
3299         return retval;
3300 }
3301
3302 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3303 {
3304         if (in_interrupt())
3305                 return 0;       /* n_r3964 calls put_char() from interrupt context */
3306         return do_con_write(tty, &ch, 1);
3307 }
3308
3309 static int con_write_room(struct tty_struct *tty)
3310 {
3311         if (tty->stopped)
3312                 return 0;
3313         return 32768;           /* No limit, really; we're not buffering */
3314 }
3315
3316 static int con_chars_in_buffer(struct tty_struct *tty)
3317 {
3318         return 0;               /* we're not buffering */
3319 }
3320
3321 /*
3322  * con_throttle and con_unthrottle are only used for
3323  * paste_selection(), which has to stuff in a large number of
3324  * characters...
3325  */
3326 static void con_throttle(struct tty_struct *tty)
3327 {
3328 }
3329
3330 static void con_unthrottle(struct tty_struct *tty)
3331 {
3332         struct vc_data *vc = tty->driver_data;
3333
3334         wake_up_interruptible(&vc->paste_wait);
3335 }
3336
3337 /*
3338  * Turn the Scroll-Lock LED on when the tty is stopped
3339  */
3340 static void con_stop(struct tty_struct *tty)
3341 {
3342         int console_num;
3343         if (!tty)
3344                 return;
3345         console_num = tty->index;
3346         if (!vc_cons_allocated(console_num))
3347                 return;
3348         vt_kbd_con_stop(console_num);
3349 }
3350
3351 /*
3352  * Turn the Scroll-Lock LED off when the console is started
3353  */
3354 static void con_start(struct tty_struct *tty)
3355 {
3356         int console_num;
3357         if (!tty)
3358                 return;
3359         console_num = tty->index;
3360         if (!vc_cons_allocated(console_num))
3361                 return;
3362         vt_kbd_con_start(console_num);
3363 }
3364
3365 static void con_flush_chars(struct tty_struct *tty)
3366 {
3367         struct vc_data *vc;
3368
3369         if (in_interrupt())     /* from flush_to_ldisc */
3370                 return;
3371
3372         /* if we race with con_close(), vt may be null */
3373         console_lock();
3374         vc = tty->driver_data;
3375         if (vc)
3376                 set_cursor(vc);
3377         console_unlock();
3378 }
3379
3380 /*
3381  * Allocate the console screen memory.
3382  */
3383 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3384 {
3385         unsigned int currcons = tty->index;
3386         struct vc_data *vc;
3387         int ret;
3388
3389         console_lock();
3390         ret = vc_allocate(currcons);
3391         if (ret)
3392                 goto unlock;
3393
3394         vc = vc_cons[currcons].d;
3395
3396         /* Still being freed */
3397         if (vc->port.tty) {
3398                 ret = -ERESTARTSYS;
3399                 goto unlock;
3400         }
3401
3402         ret = tty_port_install(&vc->port, driver, tty);
3403         if (ret)
3404                 goto unlock;
3405
3406         tty->driver_data = vc;
3407         vc->port.tty = tty;
3408         tty_port_get(&vc->port);
3409
3410         if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3411                 tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3412                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3413         }
3414         if (vc->vc_utf)
3415                 tty->termios.c_iflag |= IUTF8;
3416         else
3417                 tty->termios.c_iflag &= ~IUTF8;
3418 unlock:
3419         console_unlock();
3420         return ret;
3421 }
3422
3423 static int con_open(struct tty_struct *tty, struct file *filp)
3424 {
3425         /* everything done in install */
3426         return 0;
3427 }
3428
3429
3430 static void con_close(struct tty_struct *tty, struct file *filp)
3431 {
3432         /* Nothing to do - we defer to shutdown */
3433 }
3434
3435 static void con_shutdown(struct tty_struct *tty)
3436 {
3437         struct vc_data *vc = tty->driver_data;
3438         BUG_ON(vc == NULL);
3439         console_lock();
3440         vc->port.tty = NULL;
3441         console_unlock();
3442 }
3443
3444 static void con_cleanup(struct tty_struct *tty)
3445 {
3446         struct vc_data *vc = tty->driver_data;
3447
3448         tty_port_put(&vc->port);
3449 }
3450
3451 static int default_color           = 7; /* white */
3452 static int default_italic_color    = 2; // green (ASCII)
3453 static int default_underline_color = 3; // cyan (ASCII)
3454 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3455 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3456 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3457
3458 static void vc_init(struct vc_data *vc, unsigned int rows,
3459                     unsigned int cols, int do_clear)
3460 {
3461         int j, k ;
3462
3463         vc->vc_cols = cols;
3464         vc->vc_rows = rows;
3465         vc->vc_size_row = cols << 1;
3466         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3467
3468         set_origin(vc);
3469         vc->vc_pos = vc->vc_origin;
3470         reset_vc(vc);
3471         for (j=k=0; j<16; j++) {
3472                 vc->vc_palette[k++] = default_red[j] ;
3473                 vc->vc_palette[k++] = default_grn[j] ;
3474                 vc->vc_palette[k++] = default_blu[j] ;
3475         }
3476         vc->vc_def_color       = default_color;
3477         vc->vc_ulcolor         = default_underline_color;
3478         vc->vc_itcolor         = default_italic_color;
3479         vc->vc_halfcolor       = 0x08;   /* grey */
3480         init_waitqueue_head(&vc->paste_wait);
3481         reset_terminal(vc, do_clear);
3482 }
3483
3484 /*
3485  * This routine initializes console interrupts, and does nothing
3486  * else. If you want the screen to clear, call tty_write with
3487  * the appropriate escape-sequence.
3488  */
3489
3490 static int __init con_init(void)
3491 {
3492         const char *display_desc = NULL;
3493         struct vc_data *vc;
3494         unsigned int currcons = 0, i;
3495
3496         console_lock();
3497
3498         if (!conswitchp)
3499                 conswitchp = &dummy_con;
3500         display_desc = conswitchp->con_startup();
3501         if (!display_desc) {
3502                 fg_console = 0;
3503                 console_unlock();
3504                 return 0;
3505         }
3506
3507         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3508                 struct con_driver *con_driver = &registered_con_driver[i];
3509
3510                 if (con_driver->con == NULL) {
3511                         con_driver->con = conswitchp;
3512                         con_driver->desc = display_desc;
3513                         con_driver->flag = CON_DRIVER_FLAG_INIT;
3514                         con_driver->first = 0;
3515                         con_driver->last = MAX_NR_CONSOLES - 1;
3516                         break;
3517                 }
3518         }
3519
3520         for (i = 0; i < MAX_NR_CONSOLES; i++)
3521                 con_driver_map[i] = conswitchp;
3522
3523         if (blankinterval) {
3524                 blank_state = blank_normal_wait;
3525                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3526         }
3527
3528         for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3529                 vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3530                 INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3531                 tty_port_init(&vc->port);
3532                 visual_init(vc, currcons, 1);
3533                 /* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3534                 vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3535                 vc_init(vc, vc->vc_rows, vc->vc_cols,
3536                         currcons || !vc->vc_sw->con_save_screen);
3537         }
3538         currcons = fg_console = 0;
3539         master_display_fg = vc = vc_cons[currcons].d;
3540         set_origin(vc);
3541         save_screen(vc);
3542         gotoxy(vc, vc->state.x, vc->state.y);
3543         csi_J(vc, 0);
3544         update_screen(vc);
3545         pr_info("Console: %s %s %dx%d\n",
3546                 vc->vc_can_do_color ? "colour" : "mono",
3547                 display_desc, vc->vc_cols, vc->vc_rows);
3548         printable = 1;
3549
3550         console_unlock();
3551
3552 #ifdef CONFIG_VT_CONSOLE
3553         register_console(&vt_console_driver);
3554 #endif
3555         return 0;
3556 }
3557 console_initcall(con_init);
3558
3559 static const struct tty_operations con_ops = {
3560         .install = con_install,
3561         .open = con_open,
3562         .close = con_close,
3563         .write = con_write,
3564         .write_room = con_write_room,
3565         .put_char = con_put_char,
3566         .flush_chars = con_flush_chars,
3567         .chars_in_buffer = con_chars_in_buffer,
3568         .ioctl = vt_ioctl,
3569 #ifdef CONFIG_COMPAT
3570         .compat_ioctl = vt_compat_ioctl,
3571 #endif
3572         .stop = con_stop,
3573         .start = con_start,
3574         .throttle = con_throttle,
3575         .unthrottle = con_unthrottle,
3576         .resize = vt_resize,
3577         .shutdown = con_shutdown,
3578         .cleanup = con_cleanup,
3579 };
3580
3581 static struct cdev vc0_cdev;
3582
3583 static ssize_t show_tty_active(struct device *dev,
3584                                 struct device_attribute *attr, char *buf)
3585 {
3586         return sprintf(buf, "tty%d\n", fg_console + 1);
3587 }
3588 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3589
3590 static struct attribute *vt_dev_attrs[] = {
3591         &dev_attr_active.attr,
3592         NULL
3593 };
3594
3595 ATTRIBUTE_GROUPS(vt_dev);
3596
3597 int __init vty_init(const struct file_operations *console_fops)
3598 {
3599         cdev_init(&vc0_cdev, console_fops);
3600         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3601             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3602                 panic("Couldn't register /dev/tty0 driver\n");
3603         tty0dev = device_create_with_groups(tty_class, NULL,
3604                                             MKDEV(TTY_MAJOR, 0), NULL,
3605                                             vt_dev_groups, "tty0");
3606         if (IS_ERR(tty0dev))
3607                 tty0dev = NULL;
3608
3609         vcs_init();
3610
3611         console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3612         if (!console_driver)
3613                 panic("Couldn't allocate console driver\n");
3614
3615         console_driver->name = "tty";
3616         console_driver->name_base = 1;
3617         console_driver->major = TTY_MAJOR;
3618         console_driver->minor_start = 1;
3619         console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3620         console_driver->init_termios = tty_std_termios;
3621         if (default_utf8)
3622                 console_driver->init_termios.c_iflag |= IUTF8;
3623         console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3624         tty_set_operations(console_driver, &con_ops);
3625         if (tty_register_driver(console_driver))
3626                 panic("Couldn't register console driver\n");
3627         kbd_init();
3628         console_map_init();
3629 #ifdef CONFIG_MDA_CONSOLE
3630         mda_console_init();
3631 #endif
3632         return 0;
3633 }
3634
3635 #ifndef VT_SINGLE_DRIVER
3636
3637 static struct class *vtconsole_class;
3638
3639 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3640                            int deflt)
3641 {
3642         struct module *owner = csw->owner;
3643         const char *desc = NULL;
3644         struct con_driver *con_driver;
3645         int i, j = -1, k = -1, retval = -ENODEV;
3646
3647         if (!try_module_get(owner))
3648                 return -ENODEV;
3649
3650         WARN_CONSOLE_UNLOCKED();
3651
3652         /* check if driver is registered */
3653         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3654                 con_driver = &registered_con_driver[i];
3655
3656                 if (con_driver->con == csw) {
3657                         desc = con_driver->desc;
3658                         retval = 0;
3659                         break;
3660                 }
3661         }
3662
3663         if (retval)
3664                 goto err;
3665
3666         if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3667                 csw->con_startup();
3668                 con_driver->flag |= CON_DRIVER_FLAG_INIT;
3669         }
3670
3671         if (deflt) {
3672                 if (conswitchp)
3673                         module_put(conswitchp->owner);
3674
3675                 __module_get(owner);
3676                 conswitchp = csw;
3677         }
3678
3679         first = max(first, con_driver->first);
3680         last = min(last, con_driver->last);
3681
3682         for (i = first; i <= last; i++) {
3683                 int old_was_color;
3684                 struct vc_data *vc = vc_cons[i].d;
3685
3686                 if (con_driver_map[i])
3687                         module_put(con_driver_map[i]->owner);
3688                 __module_get(owner);
3689                 con_driver_map[i] = csw;
3690
3691                 if (!vc || !vc->vc_sw)
3692                         continue;
3693
3694                 j = i;
3695
3696                 if (con_is_visible(vc)) {
3697                         k = i;
3698                         save_screen(vc);
3699                 }
3700
3701                 old_was_color = vc->vc_can_do_color;
3702                 vc->vc_sw->con_deinit(vc);
3703                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3704                 visual_init(vc, i, 0);
3705                 set_origin(vc);
3706                 update_attr(vc);
3707
3708                 /* If the console changed between mono <-> color, then
3709                  * the attributes in the screenbuf will be wrong.  The
3710                  * following resets all attributes to something sane.
3711                  */
3712                 if (old_was_color != vc->vc_can_do_color)
3713                         clear_buffer_attributes(vc);
3714         }
3715
3716         pr_info("Console: switching ");
3717         if (!deflt)
3718                 pr_cont("consoles %d-%d ", first + 1, last + 1);
3719         if (j >= 0) {
3720                 struct vc_data *vc = vc_cons[j].d;
3721
3722                 pr_cont("to %s %s %dx%d\n",
3723                         vc->vc_can_do_color ? "colour" : "mono",
3724                         desc, vc->vc_cols, vc->vc_rows);
3725
3726                 if (k >= 0) {
3727                         vc = vc_cons[k].d;
3728                         update_screen(vc);
3729                 }
3730         } else {
3731                 pr_cont("to %s\n", desc);
3732         }
3733
3734         retval = 0;
3735 err:
3736         module_put(owner);
3737         return retval;
3738 };
3739
3740
3741 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3742 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3743 {
3744         struct module *owner = csw->owner;
3745         const struct consw *defcsw = NULL;
3746         struct con_driver *con_driver = NULL, *con_back = NULL;
3747         int i, retval = -ENODEV;
3748
3749         if (!try_module_get(owner))
3750                 return -ENODEV;
3751
3752         WARN_CONSOLE_UNLOCKED();
3753
3754         /* check if driver is registered and if it is unbindable */
3755         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3756                 con_driver = &registered_con_driver[i];
3757
3758                 if (con_driver->con == csw &&
3759                     con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3760                         retval = 0;
3761                         break;
3762                 }
3763         }
3764
3765         if (retval)
3766                 goto err;
3767
3768         retval = -ENODEV;
3769
3770         /* check if backup driver exists */
3771         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3772                 con_back = &registered_con_driver[i];
3773
3774                 if (con_back->con && con_back->con != csw) {
3775                         defcsw = con_back->con;
3776                         retval = 0;
3777                         break;
3778                 }
3779         }
3780
3781         if (retval)
3782                 goto err;
3783
3784         if (!con_is_bound(csw))
3785                 goto err;
3786
3787         first = max(first, con_driver->first);
3788         last = min(last, con_driver->last);
3789
3790         for (i = first; i <= last; i++) {
3791                 if (con_driver_map[i] == csw) {
3792                         module_put(csw->owner);
3793                         con_driver_map[i] = NULL;
3794                 }
3795         }
3796
3797         if (!con_is_bound(defcsw)) {
3798                 const struct consw *defconsw = conswitchp;
3799
3800                 defcsw->con_startup();
3801                 con_back->flag |= CON_DRIVER_FLAG_INIT;
3802                 /*
3803                  * vgacon may change the default driver to point
3804                  * to dummycon, we restore it here...
3805                  */
3806                 conswitchp = defconsw;
3807         }
3808
3809         if (!con_is_bound(csw))
3810                 con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3811
3812         /* ignore return value, binding should not fail */
3813         do_bind_con_driver(defcsw, first, last, deflt);
3814 err:
3815         module_put(owner);
3816         return retval;
3817
3818 }
3819 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3820
3821 static int vt_bind(struct con_driver *con)
3822 {
3823         const struct consw *defcsw = NULL, *csw = NULL;
3824         int i, more = 1, first = -1, last = -1, deflt = 0;
3825
3826         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3827                 goto err;
3828
3829         csw = con->con;
3830
3831         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3832                 struct con_driver *con = &registered_con_driver[i];
3833
3834                 if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3835                         defcsw = con->con;
3836                         break;
3837                 }
3838         }
3839
3840         if (!defcsw)
3841                 goto err;
3842
3843         while (more) {
3844                 more = 0;
3845
3846                 for (i = con->first; i <= con->last; i++) {
3847                         if (con_driver_map[i] == defcsw) {
3848                                 if (first == -1)
3849                                         first = i;
3850                                 last = i;
3851                                 more = 1;
3852                         } else if (first != -1)
3853                                 break;
3854                 }
3855
3856                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3857                         deflt = 1;
3858
3859                 if (first != -1)
3860                         do_bind_con_driver(csw, first, last, deflt);
3861
3862                 first = -1;
3863                 last = -1;
3864                 deflt = 0;
3865         }
3866
3867 err:
3868         return 0;
3869 }
3870
3871 static int vt_unbind(struct con_driver *con)
3872 {
3873         const struct consw *csw = NULL;
3874         int i, more = 1, first = -1, last = -1, deflt = 0;
3875         int ret;
3876
3877         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3878                 goto err;
3879
3880         csw = con->con;
3881
3882         while (more) {
3883                 more = 0;
3884
3885                 for (i = con->first; i <= con->last; i++) {
3886                         if (con_driver_map[i] == csw) {
3887                                 if (first == -1)
3888                                         first = i;
3889                                 last = i;
3890                                 more = 1;
3891                         } else if (first != -1)
3892                                 break;
3893                 }
3894
3895                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3896                         deflt = 1;
3897
3898                 if (first != -1) {
3899                         ret = do_unbind_con_driver(csw, first, last, deflt);
3900                         if (ret != 0)
3901                                 return ret;
3902                 }
3903
3904                 first = -1;
3905                 last = -1;
3906                 deflt = 0;
3907         }
3908
3909 err:
3910         return 0;
3911 }
3912 #else
3913 static inline int vt_bind(struct con_driver *con)
3914 {
3915         return 0;
3916 }
3917 static inline int vt_unbind(struct con_driver *con)
3918 {
3919         return 0;
3920 }
3921 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3922
3923 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3924                           const char *buf, size_t count)
3925 {
3926         struct con_driver *con = dev_get_drvdata(dev);
3927         int bind = simple_strtoul(buf, NULL, 0);
3928
3929         console_lock();
3930
3931         if (bind)
3932                 vt_bind(con);
3933         else
3934                 vt_unbind(con);
3935
3936         console_unlock();
3937
3938         return count;
3939 }
3940
3941 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3942                          char *buf)
3943 {
3944         struct con_driver *con = dev_get_drvdata(dev);
3945         int bind;
3946
3947         console_lock();
3948         bind = con_is_bound(con->con);
3949         console_unlock();
3950
3951         return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3952 }
3953
3954 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3955                          char *buf)
3956 {
3957         struct con_driver *con = dev_get_drvdata(dev);
3958
3959         return snprintf(buf, PAGE_SIZE, "%s %s\n",
3960                         (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3961                          con->desc);
3962
3963 }
3964
3965 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3966 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3967
3968 static struct attribute *con_dev_attrs[] = {
3969         &dev_attr_bind.attr,
3970         &dev_attr_name.attr,
3971         NULL
3972 };
3973
3974 ATTRIBUTE_GROUPS(con_dev);
3975
3976 static int vtconsole_init_device(struct con_driver *con)
3977 {
3978         con->flag |= CON_DRIVER_FLAG_ATTR;
3979         return 0;
3980 }
3981
3982 static void vtconsole_deinit_device(struct con_driver *con)
3983 {
3984         con->flag &= ~CON_DRIVER_FLAG_ATTR;
3985 }
3986
3987 /**
3988  * con_is_bound - checks if driver is bound to the console
3989  * @csw: console driver
3990  *
3991  * RETURNS: zero if unbound, nonzero if bound
3992  *
3993  * Drivers can call this and if zero, they should release
3994  * all resources allocated on con_startup()
3995  */
3996 int con_is_bound(const struct consw *csw)
3997 {
3998         int i, bound = 0;
3999
4000         WARN_CONSOLE_UNLOCKED();
4001
4002         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4003                 if (con_driver_map[i] == csw) {
4004                         bound = 1;
4005                         break;
4006                 }
4007         }
4008
4009         return bound;
4010 }
4011 EXPORT_SYMBOL(con_is_bound);
4012
4013 /**
4014  * con_is_visible - checks whether the current console is visible
4015  * @vc: virtual console
4016  *
4017  * RETURNS: zero if not visible, nonzero if visible
4018  */
4019 bool con_is_visible(const struct vc_data *vc)
4020 {
4021         WARN_CONSOLE_UNLOCKED();
4022
4023         return *vc->vc_display_fg == vc;
4024 }
4025 EXPORT_SYMBOL(con_is_visible);
4026
4027 /**
4028  * con_debug_enter - prepare the console for the kernel debugger
4029  * @vc: virtual console
4030  *
4031  * Called when the console is taken over by the kernel debugger, this
4032  * function needs to save the current console state, then put the console
4033  * into a state suitable for the kernel debugger.
4034  *
4035  * RETURNS:
4036  * Zero on success, nonzero if a failure occurred when trying to prepare
4037  * the console for the debugger.
4038  */
4039 int con_debug_enter(struct vc_data *vc)
4040 {
4041         int ret = 0;
4042
4043         saved_fg_console = fg_console;
4044         saved_last_console = last_console;
4045         saved_want_console = want_console;
4046         saved_vc_mode = vc->vc_mode;
4047         saved_console_blanked = console_blanked;
4048         vc->vc_mode = KD_TEXT;
4049         console_blanked = 0;
4050         if (vc->vc_sw->con_debug_enter)
4051                 ret = vc->vc_sw->con_debug_enter(vc);
4052 #ifdef CONFIG_KGDB_KDB
4053         /* Set the initial LINES variable if it is not already set */
4054         if (vc->vc_rows < 999) {
4055                 int linecount;
4056                 char lns[4];
4057                 const char *setargs[3] = {
4058                         "set",
4059                         "LINES",
4060                         lns,
4061                 };
4062                 if (kdbgetintenv(setargs[0], &linecount)) {
4063                         snprintf(lns, 4, "%i", vc->vc_rows);
4064                         kdb_set(2, setargs);
4065                 }
4066         }
4067         if (vc->vc_cols < 999) {
4068                 int colcount;
4069                 char cols[4];
4070                 const char *setargs[3] = {
4071                         "set",
4072                         "COLUMNS",
4073                         cols,
4074                 };
4075                 if (kdbgetintenv(setargs[0], &colcount)) {
4076                         snprintf(cols, 4, "%i", vc->vc_cols);
4077                         kdb_set(2, setargs);
4078                 }
4079         }
4080 #endif /* CONFIG_KGDB_KDB */
4081         return ret;
4082 }
4083 EXPORT_SYMBOL_GPL(con_debug_enter);
4084
4085 /**
4086  * con_debug_leave - restore console state
4087  *
4088  * Restore the console state to what it was before the kernel debugger
4089  * was invoked.
4090  *
4091  * RETURNS:
4092  * Zero on success, nonzero if a failure occurred when trying to restore
4093  * the console.
4094  */
4095 int con_debug_leave(void)
4096 {
4097         struct vc_data *vc;
4098         int ret = 0;
4099
4100         fg_console = saved_fg_console;
4101         last_console = saved_last_console;
4102         want_console = saved_want_console;
4103         console_blanked = saved_console_blanked;
4104         vc_cons[fg_console].d->vc_mode = saved_vc_mode;
4105
4106         vc = vc_cons[fg_console].d;
4107         if (vc->vc_sw->con_debug_leave)
4108                 ret = vc->vc_sw->con_debug_leave(vc);
4109         return ret;
4110 }
4111 EXPORT_SYMBOL_GPL(con_debug_leave);
4112
4113 static int do_register_con_driver(const struct consw *csw, int first, int last)
4114 {
4115         struct module *owner = csw->owner;
4116         struct con_driver *con_driver;
4117         const char *desc;
4118         int i, retval;
4119
4120         WARN_CONSOLE_UNLOCKED();
4121
4122         if (!try_module_get(owner))
4123                 return -ENODEV;
4124
4125         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4126                 con_driver = &registered_con_driver[i];
4127
4128                 /* already registered */
4129                 if (con_driver->con == csw) {
4130                         retval = -EBUSY;
4131                         goto err;
4132                 }
4133         }
4134
4135         desc = csw->con_startup();
4136         if (!desc) {
4137                 retval = -ENODEV;
4138                 goto err;
4139         }
4140
4141         retval = -EINVAL;
4142
4143         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4144                 con_driver = &registered_con_driver[i];
4145
4146                 if (con_driver->con == NULL &&
4147                     !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
4148                         con_driver->con = csw;
4149                         con_driver->desc = desc;
4150                         con_driver->node = i;
4151                         con_driver->flag = CON_DRIVER_FLAG_MODULE |
4152                                            CON_DRIVER_FLAG_INIT;
4153                         con_driver->first = first;
4154                         con_driver->last = last;
4155                         retval = 0;
4156                         break;
4157                 }
4158         }
4159
4160         if (retval)
4161                 goto err;
4162
4163         con_driver->dev =
4164                 device_create_with_groups(vtconsole_class, NULL,
4165                                           MKDEV(0, con_driver->node),
4166                                           con_driver, con_dev_groups,
4167                                           "vtcon%i", con_driver->node);
4168         if (IS_ERR(con_driver->dev)) {
4169                 pr_warn("Unable to create device for %s; errno = %ld\n",
4170                         con_driver->desc, PTR_ERR(con_driver->dev));
4171                 con_driver->dev = NULL;
4172         } else {
4173                 vtconsole_init_device(con_driver);
4174         }
4175
4176 err:
4177         module_put(owner);
4178         return retval;
4179 }
4180
4181
4182 /**
4183  * do_unregister_con_driver - unregister console driver from console layer
4184  * @csw: console driver
4185  *
4186  * DESCRIPTION: All drivers that registers to the console layer must
4187  * call this function upon exit, or if the console driver is in a state
4188  * where it won't be able to handle console services, such as the
4189  * framebuffer console without loaded framebuffer drivers.
4190  *
4191  * The driver must unbind first prior to unregistration.
4192  */
4193 int do_unregister_con_driver(const struct consw *csw)
4194 {
4195         int i;
4196
4197         /* cannot unregister a bound driver */
4198         if (con_is_bound(csw))
4199                 return -EBUSY;
4200
4201         if (csw == conswitchp)
4202                 return -EINVAL;
4203
4204         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4205                 struct con_driver *con_driver = &registered_con_driver[i];
4206
4207                 if (con_driver->con == csw) {
4208                         /*
4209                          * Defer the removal of the sysfs entries since that
4210                          * will acquire the kernfs s_active lock and we can't
4211                          * acquire this lock while holding the console lock:
4212                          * the unbind sysfs entry imposes already the opposite
4213                          * order. Reset con already here to prevent any later
4214                          * lookup to succeed and mark this slot as zombie, so
4215                          * it won't get reused until we complete the removal
4216                          * in the deferred work.
4217                          */
4218                         con_driver->con = NULL;
4219                         con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4220                         schedule_work(&con_driver_unregister_work);
4221
4222                         return 0;
4223                 }
4224         }
4225
4226         return -ENODEV;
4227 }
4228 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4229
4230 static void con_driver_unregister_callback(struct work_struct *ignored)
4231 {
4232         int i;
4233
4234         console_lock();
4235
4236         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4237                 struct con_driver *con_driver = &registered_con_driver[i];
4238
4239                 if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4240                         continue;
4241
4242                 console_unlock();
4243
4244                 vtconsole_deinit_device(con_driver);
4245                 device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4246
4247                 console_lock();
4248
4249                 if (WARN_ON_ONCE(con_driver->con))
4250                         con_driver->con = NULL;
4251                 con_driver->desc = NULL;
4252                 con_driver->dev = NULL;
4253                 con_driver->node = 0;
4254                 WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4255                 con_driver->flag = 0;
4256                 con_driver->first = 0;
4257                 con_driver->last = 0;
4258         }
4259
4260         console_unlock();
4261 }
4262
4263 /*
4264  *      If we support more console drivers, this function is used
4265  *      when a driver wants to take over some existing consoles
4266  *      and become default driver for newly opened ones.
4267  *
4268  *      do_take_over_console is basically a register followed by bind
4269  */
4270 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4271 {
4272         int err;
4273
4274         err = do_register_con_driver(csw, first, last);
4275         /*
4276          * If we get an busy error we still want to bind the console driver
4277          * and return success, as we may have unbound the console driver
4278          * but not unregistered it.
4279          */
4280         if (err == -EBUSY)
4281                 err = 0;
4282         if (!err)
4283                 do_bind_con_driver(csw, first, last, deflt);
4284
4285         return err;
4286 }
4287 EXPORT_SYMBOL_GPL(do_take_over_console);
4288
4289
4290 /*
4291  * give_up_console is a wrapper to unregister_con_driver. It will only
4292  * work if driver is fully unbound.
4293  */
4294 void give_up_console(const struct consw *csw)
4295 {
4296         console_lock();
4297         do_unregister_con_driver(csw);
4298         console_unlock();
4299 }
4300
4301 static int __init vtconsole_class_init(void)
4302 {
4303         int i;
4304
4305         vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4306         if (IS_ERR(vtconsole_class)) {
4307                 pr_warn("Unable to create vt console class; errno = %ld\n",
4308                         PTR_ERR(vtconsole_class));
4309                 vtconsole_class = NULL;
4310         }
4311
4312         /* Add system drivers to sysfs */
4313         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4314                 struct con_driver *con = &registered_con_driver[i];
4315
4316                 if (con->con && !con->dev) {
4317                         con->dev =
4318                                 device_create_with_groups(vtconsole_class, NULL,
4319                                                           MKDEV(0, con->node),
4320                                                           con, con_dev_groups,
4321                                                           "vtcon%i", con->node);
4322
4323                         if (IS_ERR(con->dev)) {
4324                                 pr_warn("Unable to create device for %s; errno = %ld\n",
4325                                         con->desc, PTR_ERR(con->dev));
4326                                 con->dev = NULL;
4327                         } else {
4328                                 vtconsole_init_device(con);
4329                         }
4330                 }
4331         }
4332
4333         return 0;
4334 }
4335 postcore_initcall(vtconsole_class_init);
4336
4337 #endif
4338
4339 /*
4340  *      Screen blanking
4341  */
4342
4343 static int set_vesa_blanking(char __user *p)
4344 {
4345         unsigned int mode;
4346
4347         if (get_user(mode, p + 1))
4348                 return -EFAULT;
4349
4350         vesa_blank_mode = (mode < 4) ? mode : 0;
4351         return 0;
4352 }
4353
4354 void do_blank_screen(int entering_gfx)
4355 {
4356         struct vc_data *vc = vc_cons[fg_console].d;
4357         int i;
4358
4359         might_sleep();
4360
4361         WARN_CONSOLE_UNLOCKED();
4362
4363         if (console_blanked) {
4364                 if (blank_state == blank_vesa_wait) {
4365                         blank_state = blank_off;
4366                         vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4367                 }
4368                 return;
4369         }
4370
4371         /* entering graphics mode? */
4372         if (entering_gfx) {
4373                 hide_cursor(vc);
4374                 save_screen(vc);
4375                 vc->vc_sw->con_blank(vc, -1, 1);
4376                 console_blanked = fg_console + 1;
4377                 blank_state = blank_off;
4378                 set_origin(vc);
4379                 return;
4380         }
4381
4382         blank_state = blank_off;
4383
4384         /* don't blank graphics */
4385         if (vc->vc_mode != KD_TEXT) {
4386                 console_blanked = fg_console + 1;
4387                 return;
4388         }
4389
4390         hide_cursor(vc);
4391         del_timer_sync(&console_timer);
4392         blank_timer_expired = 0;
4393
4394         save_screen(vc);
4395         /* In case we need to reset origin, blanking hook returns 1 */
4396         i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4397         console_blanked = fg_console + 1;
4398         if (i)
4399                 set_origin(vc);
4400
4401         if (console_blank_hook && console_blank_hook(1))
4402                 return;
4403
4404         if (vesa_off_interval && vesa_blank_mode) {
4405                 blank_state = blank_vesa_wait;
4406                 mod_timer(&console_timer, jiffies + vesa_off_interval);
4407         }
4408         vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4409 }
4410 EXPORT_SYMBOL(do_blank_screen);
4411
4412 /*
4413  * Called by timer as well as from vt_console_driver
4414  */
4415 void do_unblank_screen(int leaving_gfx)
4416 {
4417         struct vc_data *vc;
4418
4419         /* This should now always be called from a "sane" (read: can schedule)
4420          * context for the sake of the low level drivers, except in the special
4421          * case of oops_in_progress
4422          */
4423         if (!oops_in_progress)
4424                 might_sleep();
4425
4426         WARN_CONSOLE_UNLOCKED();
4427
4428         ignore_poke = 0;
4429         if (!console_blanked)
4430                 return;
4431         if (!vc_cons_allocated(fg_console)) {
4432                 /* impossible */
4433                 pr_warn("unblank_screen: tty %d not allocated ??\n",
4434                         fg_console + 1);
4435                 return;
4436         }
4437         vc = vc_cons[fg_console].d;
4438         if (vc->vc_mode != KD_TEXT)
4439                 return; /* but leave console_blanked != 0 */
4440
4441         if (blankinterval) {
4442                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4443                 blank_state = blank_normal_wait;
4444         }
4445
4446         console_blanked = 0;
4447         if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4448                 /* Low-level driver cannot restore -> do it ourselves */
4449                 update_screen(vc);
4450         if (console_blank_hook)
4451                 console_blank_hook(0);
4452         set_palette(vc);
4453         set_cursor(vc);
4454         vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4455 }
4456 EXPORT_SYMBOL(do_unblank_screen);
4457
4458 /*
4459  * This is called by the outside world to cause a forced unblank, mostly for
4460  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4461  * call it with 1 as an argument and so force a mode restore... that may kill
4462  * X or at least garbage the screen but would also make the Oops visible...
4463  */
4464 void unblank_screen(void)
4465 {
4466         do_unblank_screen(0);
4467 }
4468
4469 /*
4470  * We defer the timer blanking to work queue so it can take the console mutex
4471  * (console operations can still happen at irq time, but only from printk which
4472  * has the console mutex. Not perfect yet, but better than no locking
4473  */
4474 static void blank_screen_t(struct timer_list *unused)
4475 {
4476         blank_timer_expired = 1;
4477         schedule_work(&console_work);
4478 }
4479
4480 void poke_blanked_console(void)
4481 {
4482         WARN_CONSOLE_UNLOCKED();
4483
4484         /* Add this so we quickly catch whoever might call us in a non
4485          * safe context. Nowadays, unblank_screen() isn't to be called in
4486          * atomic contexts and is allowed to schedule (with the special case
4487          * of oops_in_progress, but that isn't of any concern for this
4488          * function. --BenH.
4489          */
4490         might_sleep();
4491
4492         /* This isn't perfectly race free, but a race here would be mostly harmless,
4493          * at worse, we'll do a spurrious blank and it's unlikely
4494          */
4495         del_timer(&console_timer);
4496         blank_timer_expired = 0;
4497
4498         if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4499                 return;
4500         if (console_blanked)
4501                 unblank_screen();
4502         else if (blankinterval) {
4503                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4504                 blank_state = blank_normal_wait;
4505         }
4506 }
4507
4508 /*
4509  *      Palettes
4510  */
4511
4512 static void set_palette(struct vc_data *vc)
4513 {
4514         WARN_CONSOLE_UNLOCKED();
4515
4516         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4517                 vc->vc_sw->con_set_palette(vc, color_table);
4518 }
4519
4520 /*
4521  * Load palette into the DAC registers. arg points to a colour
4522  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4523  */
4524
4525 int con_set_cmap(unsigned char __user *arg)
4526 {
4527         int i, j, k;
4528         unsigned char colormap[3*16];
4529
4530         if (copy_from_user(colormap, arg, sizeof(colormap)))
4531                 return -EFAULT;
4532
4533         console_lock();
4534         for (i = k = 0; i < 16; i++) {
4535                 default_red[i] = colormap[k++];
4536                 default_grn[i] = colormap[k++];
4537                 default_blu[i] = colormap[k++];
4538         }
4539         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4540                 if (!vc_cons_allocated(i))
4541                         continue;
4542                 for (j = k = 0; j < 16; j++) {
4543                         vc_cons[i].d->vc_palette[k++] = default_red[j];
4544                         vc_cons[i].d->vc_palette[k++] = default_grn[j];
4545                         vc_cons[i].d->vc_palette[k++] = default_blu[j];
4546                 }
4547                 set_palette(vc_cons[i].d);
4548         }
4549         console_unlock();
4550
4551         return 0;
4552 }
4553
4554 int con_get_cmap(unsigned char __user *arg)
4555 {
4556         int i, k;
4557         unsigned char colormap[3*16];
4558
4559         console_lock();
4560         for (i = k = 0; i < 16; i++) {
4561                 colormap[k++] = default_red[i];
4562                 colormap[k++] = default_grn[i];
4563                 colormap[k++] = default_blu[i];
4564         }
4565         console_unlock();
4566
4567         if (copy_to_user(arg, colormap, sizeof(colormap)))
4568                 return -EFAULT;
4569
4570         return 0;
4571 }
4572
4573 void reset_palette(struct vc_data *vc)
4574 {
4575         int j, k;
4576         for (j=k=0; j<16; j++) {
4577                 vc->vc_palette[k++] = default_red[j];
4578                 vc->vc_palette[k++] = default_grn[j];
4579                 vc->vc_palette[k++] = default_blu[j];
4580         }
4581         set_palette(vc);
4582 }
4583
4584 /*
4585  *  Font switching
4586  *
4587  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4588  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4589  *  depending on width) reserved for each character which is kinda wasty, but
4590  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4591  *  is up to the actual low-level console-driver convert data into its favorite
4592  *  format (maybe we should add a `fontoffset' field to the `display'
4593  *  structure so we won't have to convert the fontdata all the time.
4594  *  /Jes
4595  */
4596
4597 #define max_font_size 65536
4598
4599 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4600 {
4601         struct console_font font;
4602         int rc = -EINVAL;
4603         int c;
4604
4605         if (op->data) {
4606                 font.data = kmalloc(max_font_size, GFP_KERNEL);
4607                 if (!font.data)
4608                         return -ENOMEM;
4609         } else
4610                 font.data = NULL;
4611
4612         console_lock();
4613         if (vc->vc_mode != KD_TEXT)
4614                 rc = -EINVAL;
4615         else if (vc->vc_sw->con_font_get)
4616                 rc = vc->vc_sw->con_font_get(vc, &font);
4617         else
4618                 rc = -ENOSYS;
4619         console_unlock();
4620
4621         if (rc)
4622                 goto out;
4623
4624         c = (font.width+7)/8 * 32 * font.charcount;
4625
4626         if (op->data && font.charcount > op->charcount)
4627                 rc = -ENOSPC;
4628         if (font.width > op->width || font.height > op->height)
4629                 rc = -ENOSPC;
4630         if (rc)
4631                 goto out;
4632
4633         op->height = font.height;
4634         op->width = font.width;
4635         op->charcount = font.charcount;
4636
4637         if (op->data && copy_to_user(op->data, font.data, c))
4638                 rc = -EFAULT;
4639
4640 out:
4641         kfree(font.data);
4642         return rc;
4643 }
4644
4645 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4646 {
4647         struct console_font font;
4648         int rc = -EINVAL;
4649         int size;
4650
4651         if (vc->vc_mode != KD_TEXT)
4652                 return -EINVAL;
4653         if (!op->data)
4654                 return -EINVAL;
4655         if (op->charcount > 512)
4656                 return -EINVAL;
4657         if (op->width <= 0 || op->width > 32 || !op->height || op->height > 32)
4658                 return -EINVAL;
4659         size = (op->width+7)/8 * 32 * op->charcount;
4660         if (size > max_font_size)
4661                 return -ENOSPC;
4662
4663         font.data = memdup_user(op->data, size);
4664         if (IS_ERR(font.data))
4665                 return PTR_ERR(font.data);
4666
4667         font.charcount = op->charcount;
4668         font.width = op->width;
4669         font.height = op->height;
4670
4671         console_lock();
4672         if (vc->vc_mode != KD_TEXT)
4673                 rc = -EINVAL;
4674         else if (vc->vc_sw->con_font_set) {
4675                 if (vc_is_sel(vc))
4676                         clear_selection();
4677                 rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4678         } else
4679                 rc = -ENOSYS;
4680         console_unlock();
4681         kfree(font.data);
4682         return rc;
4683 }
4684
4685 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4686 {
4687         struct console_font font = {.width = op->width, .height = op->height};
4688         char name[MAX_FONT_NAME];
4689         char *s = name;
4690         int rc;
4691
4692
4693         if (!op->data)
4694                 s = NULL;
4695         else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4696                 return -EFAULT;
4697         else
4698                 name[MAX_FONT_NAME - 1] = 0;
4699
4700         console_lock();
4701         if (vc->vc_mode != KD_TEXT) {
4702                 console_unlock();
4703                 return -EINVAL;
4704         }
4705         if (vc->vc_sw->con_font_default) {
4706                 if (vc_is_sel(vc))
4707                         clear_selection();
4708                 rc = vc->vc_sw->con_font_default(vc, &font, s);
4709         } else
4710                 rc = -ENOSYS;
4711         console_unlock();
4712         if (!rc) {
4713                 op->width = font.width;
4714                 op->height = font.height;
4715         }
4716         return rc;
4717 }
4718
4719 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4720 {
4721         switch (op->op) {
4722         case KD_FONT_OP_SET:
4723                 return con_font_set(vc, op);
4724         case KD_FONT_OP_GET:
4725                 return con_font_get(vc, op);
4726         case KD_FONT_OP_SET_DEFAULT:
4727                 return con_font_default(vc, op);
4728         case KD_FONT_OP_COPY:
4729                 /* was buggy and never really used */
4730                 return -EINVAL;
4731         }
4732         return -ENOSYS;
4733 }
4734
4735 /*
4736  *      Interface exported to selection and vcs.
4737  */
4738
4739 /* used by selection */
4740 u16 screen_glyph(const struct vc_data *vc, int offset)
4741 {
4742         u16 w = scr_readw(screenpos(vc, offset, true));
4743         u16 c = w & 0xff;
4744
4745         if (w & vc->vc_hi_font_mask)
4746                 c |= 0x100;
4747         return c;
4748 }
4749 EXPORT_SYMBOL_GPL(screen_glyph);
4750
4751 u32 screen_glyph_unicode(const struct vc_data *vc, int n)
4752 {
4753         struct uni_screen *uniscr = get_vc_uniscr(vc);
4754
4755         if (uniscr)
4756                 return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4757         return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4758 }
4759 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4760
4761 /* used by vcs - note the word offset */
4762 unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
4763 {
4764         return screenpos(vc, 2 * w_offset, viewed);
4765 }
4766 EXPORT_SYMBOL_GPL(screen_pos);
4767
4768 void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
4769 {
4770         /* clamp values if they don't fit */
4771         xy[0] = min(vc->state.x, 0xFFu);
4772         xy[1] = min(vc->state.y, 0xFFu);
4773 }
4774
4775 void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
4776 {
4777         hide_cursor(vc);
4778         gotoxy(vc, xy[0], xy[1]);
4779         set_cursor(vc);
4780 }
4781
4782 u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
4783 {
4784         if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4785                 return softcursor_original;
4786         return scr_readw(org);
4787 }
4788
4789 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4790 {
4791         scr_writew(val, org);
4792         if ((unsigned long)org == vc->vc_pos) {
4793                 softcursor_original = -1;
4794                 add_softcursor(vc);
4795         }
4796 }
4797
4798 void vcs_scr_updated(struct vc_data *vc)
4799 {
4800         notify_update(vc);
4801 }
4802
4803 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4804                 unsigned int rolled_over, void *base, unsigned int size)
4805 {
4806         unsigned long ubase = (unsigned long)base;
4807         ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4808         ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4809         ptrdiff_t origin = (void *)c->vc_origin - base;
4810         int margin = c->vc_size_row * 4;
4811         int from, wrap, from_off, avail;
4812
4813         /* Turn scrollback off */
4814         if (!lines) {
4815                 c->vc_visible_origin = c->vc_origin;
4816                 return;
4817         }
4818
4819         /* Do we have already enough to allow jumping from 0 to the end? */
4820         if (rolled_over > scr_end + margin) {
4821                 from = scr_end;
4822                 wrap = rolled_over + c->vc_size_row;
4823         } else {
4824                 from = 0;
4825                 wrap = size;
4826         }
4827
4828         from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4829         avail = (origin - from + wrap) % wrap;
4830
4831         /* Only a little piece would be left? Show all incl. the piece! */
4832         if (avail < 2 * margin)
4833                 margin = 0;
4834         if (from_off < margin)
4835                 from_off = 0;
4836         if (from_off > avail - margin)
4837                 from_off = avail;
4838
4839         c->vc_visible_origin = ubase + (from + from_off) % wrap;
4840 }
4841 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4842
4843 /*
4844  *      Visible symbols for modules
4845  */
4846
4847 EXPORT_SYMBOL(color_table);
4848 EXPORT_SYMBOL(default_red);
4849 EXPORT_SYMBOL(default_grn);
4850 EXPORT_SYMBOL(default_blu);
4851 EXPORT_SYMBOL(update_region);
4852 EXPORT_SYMBOL(redraw_screen);
4853 EXPORT_SYMBOL(vc_resize);
4854 EXPORT_SYMBOL(fg_console);
4855 EXPORT_SYMBOL(console_blank_hook);
4856 EXPORT_SYMBOL(console_blanked);
4857 EXPORT_SYMBOL(vc_cons);
4858 EXPORT_SYMBOL(global_cursor_default);
4859 #ifndef VT_SINGLE_DRIVER
4860 EXPORT_SYMBOL(give_up_console);
4861 #endif