drivers/tty/vt/vt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright (C) 1991, 1992  Linus Torvalds
   4  */
   5
   6 /*
   7  * Hopefully this will be a rather complete VT102 implementation.
   8  *
   9  * Beeping thanks to John T Kohl.
  10  *
  11  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
  12  *   Chars, and VT100 enhancements by Peter MacDonald.
  13  *
  14  * Copy and paste function by Andrew Haylett,
  15  *   some enhancements by Alessandro Rubini.
  16  *
  17  * Code to check for different video-cards mostly by Galen Hunt,
  18  * <g-hunt@ee.utah.edu>
  19  *
  20  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
  21  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
  22  *
  23  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
  24  * Resizing of consoles, aeb, 940926
  25  *
  26  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
  27  * <poe@daimi.aau.dk>
  28  *
  29  * User-defined bell sound, new setterm control sequences and printk
  30  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
  31  *
  32  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
  33  *
  34  * Merge with the abstract console driver by Geert Uytterhoeven
  35  * <geert@linux-m68k.org>, Jan 1997.
  36  *
  37  *   Original m68k console driver modifications by
  38  *
  39  *     - Arno Griffioen <arno@usn.nl>
  40  *     - David Carter <carter@cs.bris.ac.uk>
  41  *
  42  *   The abstract console driver provides a generic interface for a text
  43  *   console. It supports VGA text mode, frame buffer based graphical consoles
  44  *   and special graphics processors that are only accessible through some
  45  *   registers (e.g. a TMS340x0 GSP).
  46  *
  47  *   The interface to the hardware is specified using a special structure
  48  *   (struct consw) which contains function pointers to console operations
  49  *   (see <linux/console.h> for more information).
  50  *
  51  * Support for changeable cursor shape
  52  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
  53  *
  54  * Ported to i386 and con_scrolldelta fixed
  55  * by Emmanuel Marty <core@ggi-project.org>, April 1998
  56  *
  57  * Resurrected character buffers in videoram plus lots of other trickery
  58  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
  59  *
  60  * Removed old-style timers, introduced console_timer, made timer
  61  * deletion SMP-safe.  17Jun00, Andrew Morton
  62  *
  63  * Removed console_lock, enabled interrupts across all console operations
  64  * 13 March 2001, Andrew Morton
  65  *
  66  * Fixed UTF-8 mode so alternate charset modes always work according
  67  * to control sequences interpreted in do_con_trol function
  68  * preserving backward VT100 semigraphics compatibility,
  69  * malformed UTF sequences represented as sequences of replacement glyphs,
  70  * original codes or '?' as a last resort if replacement glyph is undefined
  71  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
  72  */
  73
  74 #include <linux/module.h>
  75 #include <linux/types.h>
  76 #include <linux/sched/signal.h>
  77 #include <linux/tty.h>
  78 #include <linux/tty_flip.h>
  79 #include <linux/kernel.h>
  80 #include <linux/string.h>
  81 #include <linux/errno.h>
  82 #include <linux/kd.h>
  83 #include <linux/slab.h>
  84 #include <linux/major.h>
  85 #include <linux/mm.h>
  86 #include <linux/console.h>
  87 #include <linux/init.h>
  88 #include <linux/mutex.h>
  89 #include <linux/vt_kern.h>
  90 #include <linux/selection.h>
  91 #include <linux/tiocl.h>
  92 #include <linux/kbd_kern.h>
  93 #include <linux/consolemap.h>
  94 #include <linux/timer.h>
  95 #include <linux/interrupt.h>
  96 #include <linux/workqueue.h>
  97 #include <linux/pm.h>
  98 #include <linux/font.h>
  99 #include <linux/bitops.h>
 100 #include <linux/notifier.h>
 101 #include <linux/device.h>
 102 #include <linux/io.h>
 103 #include <linux/uaccess.h>
 104 #include <linux/kdb.h>
 105 #include <linux/ctype.h>
 106 #include <linux/bsearch.h>
 107 #include <linux/gcd.h>
 108
 109 #define MAX_NR_CON_DRIVER 16
 110
 111 #define CON_DRIVER_FLAG_MODULE 1
 112 #define CON_DRIVER_FLAG_INIT   2
 113 #define CON_DRIVER_FLAG_ATTR   4
 114 #define CON_DRIVER_FLAG_ZOMBIE 8
 115
 116 struct con_driver {
 117         const struct consw *con;
 118         const char *desc;
 119         struct device *dev;
 120         int node;
 121         int first;
 122         int last;
 123         int flag;
 124 };
 125
 126 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
 127 const struct consw *conswitchp;
 128
 129 /* A bitmap for codes <32. A bit of 1 indicates that the code
 130  * corresponding to that bit number invokes some special action
 131  * (such as cursor movement) and should not be displayed as a
 132  * glyph unless the disp_ctrl mode is explicitly enabled.
 133  */
 134 #define CTRL_ACTION 0x0d00ff81
 135 #define CTRL_ALWAYS 0x0800f501  /* Cannot be overridden by disp_ctrl */
 136
 137 /*
 138  * Here is the default bell parameters: 750HZ, 1/8th of a second
 139  */
 140 #define DEFAULT_BELL_PITCH      750
 141 #define DEFAULT_BELL_DURATION   (HZ/8)
 142 #define DEFAULT_CURSOR_BLINK_MS 200
 143
 144 struct vc vc_cons [MAX_NR_CONSOLES];
 145
 146 #ifndef VT_SINGLE_DRIVER
 147 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
 148 #endif
 149
 150 static int con_open(struct tty_struct *, struct file *);
 151 static void vc_init(struct vc_data *vc, unsigned int rows,
 152                     unsigned int cols, int do_clear);
 153 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
 154 static void save_cur(struct vc_data *vc);
 155 static void reset_terminal(struct vc_data *vc, int do_clear);
 156 static void con_flush_chars(struct tty_struct *tty);
 157 static int set_vesa_blanking(char __user *p);
 158 static void set_cursor(struct vc_data *vc);
 159 static void hide_cursor(struct vc_data *vc);
 160 static void console_callback(struct work_struct *ignored);
 161 static void con_driver_unregister_callback(struct work_struct *ignored);
 162 static void blank_screen_t(struct timer_list *unused);
 163 static void set_palette(struct vc_data *vc);
 164
 165 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 166
 167 static int printable;           /* Is console ready for printing? */
 168 int default_utf8 = true;
 169 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 170 int global_cursor_default = -1;
 171 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
 172
 173 static int cur_default = CUR_DEFAULT;
 174 module_param(cur_default, int, S_IRUGO | S_IWUSR);
 175
 176 /*
 177  * ignore_poke: don't unblank the screen when things are typed.  This is
 178  * mainly for the privacy of braille terminal users.
 179  */
 180 static int ignore_poke;
 181
 182 int do_poke_blanked_console;
 183 int console_blanked;
 184
 185 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
 186 static int vesa_off_interval;
 187 static int blankinterval;
 188 core_param(consoleblank, blankinterval, int, 0444);
 189
 190 static DECLARE_WORK(console_work, console_callback);
 191 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
 192
 193 /*
 194  * fg_console is the current virtual console,
 195  * last_console is the last used one,
 196  * want_console is the console we want to switch to,
 197  * saved_* variants are for save/restore around kernel debugger enter/leave
 198  */
 199 int fg_console;
 200 int last_console;
 201 int want_console = -1;
 202 static int saved_fg_console;
 203 static int saved_last_console;
 204 static int saved_want_console;
 205 static int saved_vc_mode;
 206 static int saved_console_blanked;
 207
 208 /*
 209  * For each existing display, we have a pointer to console currently visible
 210  * on that display, allowing consoles other than fg_console to be refreshed
 211  * appropriately. Unless the low-level driver supplies its own display_fg
 212  * variable, we use this one for the "master display".
 213  */
 214 static struct vc_data *master_display_fg;
 215
 216 /*
 217  * Unfortunately, we need to delay tty echo when we're currently writing to the
 218  * console since the code is (and always was) not re-entrant, so we schedule
 219  * all flip requests to process context with schedule-task() and run it from
 220  * console_callback().
 221  */
 222
 223 /*
 224  * For the same reason, we defer scrollback to the console callback.
 225  */
 226 static int scrollback_delta;
 227
 228 /*
 229  * Hook so that the power management routines can (un)blank
 230  * the console on our behalf.
 231  */
 232 int (*console_blank_hook)(int);
 233
 234 static DEFINE_TIMER(console_timer, blank_screen_t);
 235 static int blank_state;
 236 static int blank_timer_expired;
 237 enum {
 238         blank_off = 0,
 239         blank_normal_wait,
 240         blank_vesa_wait,
 241 };
 242
 243 /*
 244  * /sys/class/tty/tty0/
 245  *
 246  * the attribute 'active' contains the name of the current vc
 247  * console and it supports poll() to detect vc switches
 248  */
 249 static struct device *tty0dev;
 250
 251 /*
 252  * Notifier list for console events.
 253  */
 254 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
 255
 256 int register_vt_notifier(struct notifier_block *nb)
 257 {
 258         return atomic_notifier_chain_register(&vt_notifier_list, nb);
 259 }
 260 EXPORT_SYMBOL_GPL(register_vt_notifier);
 261
 262 int unregister_vt_notifier(struct notifier_block *nb)
 263 {
 264         return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
 265 }
 266 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
 267
 268 static void notify_write(struct vc_data *vc, unsigned int unicode)
 269 {
 270         struct vt_notifier_param param = { .vc = vc, .c = unicode };
 271         atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
 272 }
 273
 274 static void notify_update(struct vc_data *vc)
 275 {
 276         struct vt_notifier_param param = { .vc = vc };
 277         atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
 278 }
 279 /*
 280  *      Low-Level Functions
 281  */
 282
 283 static inline bool con_is_fg(const struct vc_data *vc)
 284 {
 285         return vc->vc_num == fg_console;
 286 }
 287
 288 static inline bool con_should_update(const struct vc_data *vc)
 289 {
 290         return con_is_visible(vc) && !console_blanked;
 291 }
 292
 293 static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
 294 {
 295         unsigned short *p;
 296
 297         if (!viewed)
 298                 p = (unsigned short *)(vc->vc_origin + offset);
 299         else if (!vc->vc_sw->con_screen_pos)
 300                 p = (unsigned short *)(vc->vc_visible_origin + offset);
 301         else
 302                 p = vc->vc_sw->con_screen_pos(vc, offset);
 303         return p;
 304 }
 305
 306 /* Called  from the keyboard irq path.. */
 307 static inline void scrolldelta(int lines)
 308 {
 309         /* FIXME */
 310         /* scrolldelta needs some kind of consistency lock, but the BKL was
 311            and still is not protecting versus the scheduled back end */
 312         scrollback_delta += lines;
 313         schedule_console_callback();
 314 }
 315
 316 void schedule_console_callback(void)
 317 {
 318         schedule_work(&console_work);
 319 }
 320
 321 /*
 322  * Code to manage unicode-based screen buffers
 323  */
 324
 325 #ifdef NO_VC_UNI_SCREEN
 326 /* this disables and optimizes related code away at compile time */
 327 #define get_vc_uniscr(vc) NULL
 328 #else
 329 #define get_vc_uniscr(vc) vc->vc_uni_screen
 330 #endif
 331
 332 #define VC_UNI_SCREEN_DEBUG 0
 333
 334 typedef uint32_t char32_t;
 335
 336 /*
 337  * Our screen buffer is preceded by an array of line pointers so that
 338  * scrolling only implies some pointer shuffling.
 339  */
 340 struct uni_screen {
 341         char32_t *lines[0];
 342 };
 343
 344 static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
 345 {
 346         struct uni_screen *uniscr;
 347         void *p;
 348         unsigned int memsize, i;
 349
 350         /* allocate everything in one go */
 351         memsize = cols * rows * sizeof(char32_t);
 352         memsize += rows * sizeof(char32_t *);
 353         p = kmalloc(memsize, GFP_KERNEL);
 354         if (!p)
 355                 return NULL;
 356
 357         /* initial line pointers */
 358         uniscr = p;
 359         p = uniscr->lines + rows;
 360         for (i = 0; i < rows; i++) {
 361                 uniscr->lines[i] = p;
 362                 p += cols * sizeof(char32_t);
 363         }
 364         return uniscr;
 365 }
 366
 367 static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
 368 {
 369         kfree(vc->vc_uni_screen);
 370         vc->vc_uni_screen = new_uniscr;
 371 }
 372
 373 static void vc_uniscr_putc(struct vc_data *vc, char32_t uc)
 374 {
 375         struct uni_screen *uniscr = get_vc_uniscr(vc);
 376
 377         if (uniscr)
 378                 uniscr->lines[vc->vc_y][vc->vc_x] = uc;
 379 }
 380
 381 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
 382 {
 383         struct uni_screen *uniscr = get_vc_uniscr(vc);
 384
 385         if (uniscr) {
 386                 char32_t *ln = uniscr->lines[vc->vc_y];
 387                 unsigned int x = vc->vc_x, cols = vc->vc_cols;
 388
 389                 memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
 390                 memset32(&ln[x], ' ', nr);
 391         }
 392 }
 393
 394 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
 395 {
 396         struct uni_screen *uniscr = get_vc_uniscr(vc);
 397
 398         if (uniscr) {
 399                 char32_t *ln = uniscr->lines[vc->vc_y];
 400                 unsigned int x = vc->vc_x, cols = vc->vc_cols;
 401
 402                 memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
 403                 memset32(&ln[cols - nr], ' ', nr);
 404         }
 405 }
 406
 407 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
 408                                  unsigned int nr)
 409 {
 410         struct uni_screen *uniscr = get_vc_uniscr(vc);
 411
 412         if (uniscr) {
 413                 char32_t *ln = uniscr->lines[vc->vc_y];
 414
 415                 memset32(&ln[x], ' ', nr);
 416         }
 417 }
 418
 419 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
 420                                   unsigned int nr)
 421 {
 422         struct uni_screen *uniscr = get_vc_uniscr(vc);
 423
 424         if (uniscr) {
 425                 unsigned int cols = vc->vc_cols;
 426
 427                 while (nr--)
 428                         memset32(uniscr->lines[y++], ' ', cols);
 429         }
 430 }
 431
 432 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 433                              enum con_scroll dir, unsigned int nr)
 434 {
 435         struct uni_screen *uniscr = get_vc_uniscr(vc);
 436
 437         if (uniscr) {
 438                 unsigned int i, j, k, sz, d, clear;
 439
 440                 sz = b - t;
 441                 clear = b - nr;
 442                 d = nr;
 443                 if (dir == SM_DOWN) {
 444                         clear = t;
 445                         d = sz - nr;
 446                 }
 447                 for (i = 0; i < gcd(d, sz); i++) {
 448                         char32_t *tmp = uniscr->lines[t + i];
 449                         j = i;
 450                         while (1) {
 451                                 k = j + d;
 452                                 if (k >= sz)
 453                                         k -= sz;
 454                                 if (k == i)
 455                                         break;
 456                                 uniscr->lines[t + j] = uniscr->lines[t + k];
 457                                 j = k;
 458                         }
 459                         uniscr->lines[t + j] = tmp;
 460                 }
 461                 vc_uniscr_clear_lines(vc, clear, nr);
 462         }
 463 }
 464
 465 static void vc_uniscr_copy_area(struct uni_screen *dst,
 466                                 unsigned int dst_cols,
 467                                 unsigned int dst_rows,
 468                                 struct uni_screen *src,
 469                                 unsigned int src_cols,
 470                                 unsigned int src_top_row,
 471                                 unsigned int src_bot_row)
 472 {
 473         unsigned int dst_row = 0;
 474
 475         if (!dst)
 476                 return;
 477
 478         while (src_top_row < src_bot_row) {
 479                 char32_t *src_line = src->lines[src_top_row];
 480                 char32_t *dst_line = dst->lines[dst_row];
 481
 482                 memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
 483                 if (dst_cols - src_cols)
 484                         memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
 485                 src_top_row++;
 486                 dst_row++;
 487         }
 488         while (dst_row < dst_rows) {
 489                 char32_t *dst_line = dst->lines[dst_row];
 490
 491                 memset32(dst_line, ' ', dst_cols);
 492                 dst_row++;
 493         }
 494 }
 495
 496 /*
 497  * Called from vcs_read() to make sure unicode screen retrieval is possible.
 498  * This will initialize the unicode screen buffer if not already done.
 499  * This returns 0 if OK, or a negative error code otherwise.
 500  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
 501  */
 502 int vc_uniscr_check(struct vc_data *vc)
 503 {
 504         struct uni_screen *uniscr;
 505         unsigned short *p;
 506         int x, y, mask;
 507
 508         if (__is_defined(NO_VC_UNI_SCREEN))
 509                 return -EOPNOTSUPP;
 510
 511         WARN_CONSOLE_UNLOCKED();
 512
 513         if (!vc->vc_utf)
 514                 return -ENODATA;
 515
 516         if (vc->vc_uni_screen)
 517                 return 0;
 518
 519         uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
 520         if (!uniscr)
 521                 return -ENOMEM;
 522
 523         /*
 524          * Let's populate it initially with (imperfect) reverse translation.
 525          * This is the next best thing we can do short of having it enabled
 526          * from the start even when no users rely on this functionality. True
 527          * unicode content will be available after a complete screen refresh.
 528          */
 529         p = (unsigned short *)vc->vc_origin;
 530         mask = vc->vc_hi_font_mask | 0xff;
 531         for (y = 0; y < vc->vc_rows; y++) {
 532                 char32_t *line = uniscr->lines[y];
 533                 for (x = 0; x < vc->vc_cols; x++) {
 534                         u16 glyph = scr_readw(p++) & mask;
 535                         line[x] = inverse_translate(vc, glyph, true);
 536                 }
 537         }
 538
 539         vc->vc_uni_screen = uniscr;
 540         return 0;
 541 }
 542
 543 /*
 544  * Called from vcs_read() to get the unicode data from the screen.
 545  * This must be preceded by a successful call to vc_uniscr_check() once
 546  * the console lock has been taken.
 547  */
 548 void vc_uniscr_copy_line(struct vc_data *vc, void *dest, int viewed,
 549                          unsigned int row, unsigned int col, unsigned int nr)
 550 {
 551         struct uni_screen *uniscr = get_vc_uniscr(vc);
 552         int offset = row * vc->vc_size_row + col * 2;
 553         unsigned long pos;
 554
 555         BUG_ON(!uniscr);
 556
 557         pos = (unsigned long)screenpos(vc, offset, viewed);
 558         if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
 559                 /*
 560                  * Desired position falls in the main screen buffer.
 561                  * However the actual row/col might be different if
 562                  * scrollback is active.
 563                  */
 564                 row = (pos - vc->vc_origin) / vc->vc_size_row;
 565                 col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
 566                 memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t));
 567         } else {
 568                 /*
 569                  * Scrollback is active. For now let's simply backtranslate
 570                  * the screen glyphs until the unicode screen buffer does
 571                  * synchronize with console display drivers for a scrollback
 572                  * buffer of its own.
 573                  */
 574                 u16 *p = (u16 *)pos;
 575                 int mask = vc->vc_hi_font_mask | 0xff;
 576                 char32_t *uni_buf = dest;
 577                 while (nr--) {
 578                         u16 glyph = scr_readw(p++) & mask;
 579                         *uni_buf++ = inverse_translate(vc, glyph, true);
 580                 }
 581         }
 582 }
 583
 584 /* this is for validation and debugging only */
 585 static void vc_uniscr_debug_check(struct vc_data *vc)
 586 {
 587         struct uni_screen *uniscr = get_vc_uniscr(vc);
 588         unsigned short *p;
 589         int x, y, mask;
 590
 591         if (!VC_UNI_SCREEN_DEBUG || !uniscr)
 592                 return;
 593
 594         WARN_CONSOLE_UNLOCKED();
 595
 596         /*
 597          * Make sure our unicode screen translates into the same glyphs
 598          * as the actual screen. This is brutal indeed.
 599          */
 600         p = (unsigned short *)vc->vc_origin;
 601         mask = vc->vc_hi_font_mask | 0xff;
 602         for (y = 0; y < vc->vc_rows; y++) {
 603                 char32_t *line = uniscr->lines[y];
 604                 for (x = 0; x < vc->vc_cols; x++) {
 605                         u16 glyph = scr_readw(p++) & mask;
 606                         char32_t uc = line[x];
 607                         int tc = conv_uni_to_pc(vc, uc);
 608                         if (tc == -4)
 609                                 tc = conv_uni_to_pc(vc, 0xfffd);
 610                         if (tc == -4)
 611                                 tc = conv_uni_to_pc(vc, '?');
 612                         if (tc != glyph)
 613                                 pr_err_ratelimited(
 614                                         "%s: mismatch at %d,%d: glyph=%#x tc=%#x\n",
 615                                         __func__, x, y, glyph, tc);
 616                 }
 617         }
 618 }
 619
 620
 621 static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 622                 enum con_scroll dir, unsigned int nr)
 623 {
 624         u16 *clear, *d, *s;
 625
 626         if (t + nr >= b)
 627                 nr = b - t - 1;
 628         if (b > vc->vc_rows || t >= b || nr < 1)
 629                 return;
 630         vc_uniscr_scroll(vc, t, b, dir, nr);
 631         if (con_is_visible(vc) && vc->vc_sw->con_scroll(vc, t, b, dir, nr))
 632                 return;
 633
 634         s = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * t);
 635         d = (u16 *)(vc->vc_origin + vc->vc_size_row * (t + nr));
 636
 637         if (dir == SM_UP) {
 638                 clear = s + (b - t - nr) * vc->vc_cols;
 639                 swap(s, d);
 640         }
 641         scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
 642         scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
 643 }
 644
 645 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 646 {
 647         unsigned int xx, yy, offset;
 648         u16 *p;
 649
 650         p = (u16 *) start;
 651         if (!vc->vc_sw->con_getxy) {
 652                 offset = (start - vc->vc_origin) / 2;
 653                 xx = offset % vc->vc_cols;
 654                 yy = offset / vc->vc_cols;
 655         } else {
 656                 int nxx, nyy;
 657                 start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
 658                 xx = nxx; yy = nyy;
 659         }
 660         for(;;) {
 661                 u16 attrib = scr_readw(p) & 0xff00;
 662                 int startx = xx;
 663                 u16 *q = p;
 664                 while (xx < vc->vc_cols && count) {
 665                         if (attrib != (scr_readw(p) & 0xff00)) {
 666                                 if (p > q)
 667                                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 668                                 startx = xx;
 669                                 q = p;
 670                                 attrib = scr_readw(p) & 0xff00;
 671                         }
 672                         p++;
 673                         xx++;
 674                         count--;
 675                 }
 676                 if (p > q)
 677                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 678                 if (!count)
 679                         break;
 680                 xx = 0;
 681                 yy++;
 682                 if (vc->vc_sw->con_getxy) {
 683                         p = (u16 *)start;
 684                         start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
 685                 }
 686         }
 687 }
 688
 689 void update_region(struct vc_data *vc, unsigned long start, int count)
 690 {
 691         WARN_CONSOLE_UNLOCKED();
 692
 693         if (con_should_update(vc)) {
 694                 hide_cursor(vc);
 695                 do_update_region(vc, start, count);
 696                 set_cursor(vc);
 697         }
 698 }
 699
 700 /* Structure of attributes is hardware-dependent */
 701
 702 static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
 703     u8 _underline, u8 _reverse, u8 _italic)
 704 {
 705         if (vc->vc_sw->con_build_attr)
 706                 return vc->vc_sw->con_build_attr(vc, _color, _intensity,
 707                        _blink, _underline, _reverse, _italic);
 708
 709 /*
 710  * ++roman: I completely changed the attribute format for monochrome
 711  * mode (!can_do_color). The formerly used MDA (monochrome display
 712  * adapter) format didn't allow the combination of certain effects.
 713  * Now the attribute is just a bit vector:
 714  *  Bit 0..1: intensity (0..2)
 715  *  Bit 2   : underline
 716  *  Bit 3   : reverse
 717  *  Bit 7   : blink
 718  */
 719         {
 720         u8 a = _color;
 721         if (!vc->vc_can_do_color)
 722                 return _intensity |
 723                        (_italic ? 2 : 0) |
 724                        (_underline ? 4 : 0) |
 725                        (_reverse ? 8 : 0) |
 726                        (_blink ? 0x80 : 0);
 727         if (_italic)
 728                 a = (a & 0xF0) | vc->vc_itcolor;
 729         else if (_underline)
 730                 a = (a & 0xf0) | vc->vc_ulcolor;
 731         else if (_intensity == 0)
 732                 a = (a & 0xf0) | vc->vc_halfcolor;
 733         if (_reverse)
 734                 a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
 735         if (_blink)
 736                 a ^= 0x80;
 737         if (_intensity == 2)
 738                 a ^= 0x08;
 739         if (vc->vc_hi_font_mask == 0x100)
 740                 a <<= 1;
 741         return a;
 742         }
 743 }
 744
 745 static void update_attr(struct vc_data *vc)
 746 {
 747         vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
 748                       vc->vc_blink, vc->vc_underline,
 749                       vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
 750         vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
 751 }
 752
 753 /* Note: inverting the screen twice should revert to the original state */
 754 void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
 755 {
 756         unsigned short *p;
 757
 758         WARN_CONSOLE_UNLOCKED();
 759
 760         count /= 2;
 761         p = screenpos(vc, offset, viewed);
 762         if (vc->vc_sw->con_invert_region) {
 763                 vc->vc_sw->con_invert_region(vc, p, count);
 764         } else {
 765                 u16 *q = p;
 766                 int cnt = count;
 767                 u16 a;
 768
 769                 if (!vc->vc_can_do_color) {
 770                         while (cnt--) {
 771                             a = scr_readw(q);
 772                             a ^= 0x0800;
 773                             scr_writew(a, q);
 774                             q++;
 775                         }
 776                 } else if (vc->vc_hi_font_mask == 0x100) {
 777                         while (cnt--) {
 778                                 a = scr_readw(q);
 779                                 a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
 780                                 scr_writew(a, q);
 781                                 q++;
 782                         }
 783                 } else {
 784                         while (cnt--) {
 785                                 a = scr_readw(q);
 786                                 a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
 787                                 scr_writew(a, q);
 788                                 q++;
 789                         }
 790                 }
 791         }
 792
 793         if (con_should_update(vc))
 794                 do_update_region(vc, (unsigned long) p, count);
 795         notify_update(vc);
 796 }
 797
 798 /* used by selection: complement pointer position */
 799 void complement_pos(struct vc_data *vc, int offset)
 800 {
 801         static int old_offset = -1;
 802         static unsigned short old;
 803         static unsigned short oldx, oldy;
 804
 805         WARN_CONSOLE_UNLOCKED();
 806
 807         if (old_offset != -1 && old_offset >= 0 &&
 808             old_offset < vc->vc_screenbuf_size) {
 809                 scr_writew(old, screenpos(vc, old_offset, 1));
 810                 if (con_should_update(vc))
 811                         vc->vc_sw->con_putc(vc, old, oldy, oldx);
 812                 notify_update(vc);
 813         }
 814
 815         old_offset = offset;
 816
 817         if (offset != -1 && offset >= 0 &&
 818             offset < vc->vc_screenbuf_size) {
 819                 unsigned short new;
 820                 unsigned short *p;
 821                 p = screenpos(vc, offset, 1);
 822                 old = scr_readw(p);
 823                 new = old ^ vc->vc_complement_mask;
 824                 scr_writew(new, p);
 825                 if (con_should_update(vc)) {
 826                         oldx = (offset >> 1) % vc->vc_cols;
 827                         oldy = (offset >> 1) / vc->vc_cols;
 828                         vc->vc_sw->con_putc(vc, new, oldy, oldx);
 829                 }
 830                 notify_update(vc);
 831         }
 832 }
 833
 834 static void insert_char(struct vc_data *vc, unsigned int nr)
 835 {
 836         unsigned short *p = (unsigned short *) vc->vc_pos;
 837
 838         vc_uniscr_insert(vc, nr);
 839         scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
 840         scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
 841         vc->vc_need_wrap = 0;
 842         if (con_should_update(vc))
 843                 do_update_region(vc, (unsigned long) p,
 844                         vc->vc_cols - vc->vc_x);
 845 }
 846
 847 static void delete_char(struct vc_data *vc, unsigned int nr)
 848 {
 849         unsigned short *p = (unsigned short *) vc->vc_pos;
 850
 851         vc_uniscr_delete(vc, nr);
 852         scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
 853         scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
 854                         nr * 2);
 855         vc->vc_need_wrap = 0;
 856         if (con_should_update(vc))
 857                 do_update_region(vc, (unsigned long) p,
 858                         vc->vc_cols - vc->vc_x);
 859 }
 860
 861 static int softcursor_original = -1;
 862
 863 static void add_softcursor(struct vc_data *vc)
 864 {
 865         int i = scr_readw((u16 *) vc->vc_pos);
 866         u32 type = vc->vc_cursor_type;
 867
 868         if (! (type & 0x10)) return;
 869         if (softcursor_original != -1) return;
 870         softcursor_original = i;
 871         i |= ((type >> 8) & 0xff00 );
 872         i ^= ((type) & 0xff00 );
 873         if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
 874         if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
 875         scr_writew(i, (u16 *) vc->vc_pos);
 876         if (con_should_update(vc))
 877                 vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
 878 }
 879
 880 static void hide_softcursor(struct vc_data *vc)
 881 {
 882         if (softcursor_original != -1) {
 883                 scr_writew(softcursor_original, (u16 *)vc->vc_pos);
 884                 if (con_should_update(vc))
 885                         vc->vc_sw->con_putc(vc, softcursor_original,
 886                                         vc->vc_y, vc->vc_x);
 887                 softcursor_original = -1;
 888         }
 889 }
 890
 891 static void hide_cursor(struct vc_data *vc)
 892 {
 893         if (vc == sel_cons)
 894                 clear_selection();
 895         vc->vc_sw->con_cursor(vc, CM_ERASE);
 896         hide_softcursor(vc);
 897 }
 898
 899 static void set_cursor(struct vc_data *vc)
 900 {
 901         if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
 902                 return;
 903         if (vc->vc_deccm) {
 904                 if (vc == sel_cons)
 905                         clear_selection();
 906                 add_softcursor(vc);
 907                 if ((vc->vc_cursor_type & 0x0f) != 1)
 908                         vc->vc_sw->con_cursor(vc, CM_DRAW);
 909         } else
 910                 hide_cursor(vc);
 911 }
 912
 913 static void set_origin(struct vc_data *vc)
 914 {
 915         WARN_CONSOLE_UNLOCKED();
 916
 917         if (!con_is_visible(vc) ||
 918             !vc->vc_sw->con_set_origin ||
 919             !vc->vc_sw->con_set_origin(vc))
 920                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
 921         vc->vc_visible_origin = vc->vc_origin;
 922         vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
 923         vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
 924 }
 925
 926 static void save_screen(struct vc_data *vc)
 927 {
 928         WARN_CONSOLE_UNLOCKED();
 929
 930         if (vc->vc_sw->con_save_screen)
 931                 vc->vc_sw->con_save_screen(vc);
 932 }
 933
 934 static void flush_scrollback(struct vc_data *vc)
 935 {
 936         WARN_CONSOLE_UNLOCKED();
 937
 938         if (vc->vc_sw->con_flush_scrollback)
 939                 vc->vc_sw->con_flush_scrollback(vc);
 940 }
 941
 942 /*
 943  *      Redrawing of screen
 944  */
 945
 946 void clear_buffer_attributes(struct vc_data *vc)
 947 {
 948         unsigned short *p = (unsigned short *)vc->vc_origin;
 949         int count = vc->vc_screenbuf_size / 2;
 950         int mask = vc->vc_hi_font_mask | 0xff;
 951
 952         for (; count > 0; count--, p++) {
 953                 scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
 954         }
 955 }
 956
 957 void redraw_screen(struct vc_data *vc, int is_switch)
 958 {
 959         int redraw = 0;
 960
 961         WARN_CONSOLE_UNLOCKED();
 962
 963         if (!vc) {
 964                 /* strange ... */
 965                 /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
 966                 return;
 967         }
 968
 969         if (is_switch) {
 970                 struct vc_data *old_vc = vc_cons[fg_console].d;
 971                 if (old_vc == vc)
 972                         return;
 973                 if (!con_is_visible(vc))
 974                         redraw = 1;
 975                 *vc->vc_display_fg = vc;
 976                 fg_console = vc->vc_num;
 977                 hide_cursor(old_vc);
 978                 if (!con_is_visible(old_vc)) {
 979                         save_screen(old_vc);
 980                         set_origin(old_vc);
 981                 }
 982                 if (tty0dev)
 983                         sysfs_notify(&tty0dev->kobj, NULL, "active");
 984         } else {
 985                 hide_cursor(vc);
 986                 redraw = 1;
 987         }
 988
 989         if (redraw) {
 990                 int update;
 991                 int old_was_color = vc->vc_can_do_color;
 992
 993                 set_origin(vc);
 994                 update = vc->vc_sw->con_switch(vc);
 995                 set_palette(vc);
 996                 /*
 997                  * If console changed from mono<->color, the best we can do
 998                  * is to clear the buffer attributes. As it currently stands,
 999                  * rebuilding new attributes from the old buffer is not doable
1000                  * without overly complex code.
1001                  */
1002                 if (old_was_color != vc->vc_can_do_color) {
1003                         update_attr(vc);
1004                         clear_buffer_attributes(vc);
1005                 }
1006
1007                 /* Forcibly update if we're panicing */
1008                 if ((update && vc->vc_mode != KD_GRAPHICS) ||
1009                     vt_force_oops_output(vc))
1010                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
1011         }
1012         set_cursor(vc);
1013         if (is_switch) {
1014                 set_leds();
1015                 compute_shiftstate();
1016                 notify_update(vc);
1017         }
1018 }
1019
1020 /*
1021  *      Allocation, freeing and resizing of VTs.
1022  */
1023
1024 int vc_cons_allocated(unsigned int i)
1025 {
1026         return (i < MAX_NR_CONSOLES && vc_cons[i].d);
1027 }
1028
1029 static void visual_init(struct vc_data *vc, int num, int init)
1030 {
1031         /* ++Geert: vc->vc_sw->con_init determines console size */
1032         if (vc->vc_sw)
1033                 module_put(vc->vc_sw->owner);
1034         vc->vc_sw = conswitchp;
1035 #ifndef VT_SINGLE_DRIVER
1036         if (con_driver_map[num])
1037                 vc->vc_sw = con_driver_map[num];
1038 #endif
1039         __module_get(vc->vc_sw->owner);
1040         vc->vc_num = num;
1041         vc->vc_display_fg = &master_display_fg;
1042         if (vc->vc_uni_pagedir_loc)
1043                 con_free_unimap(vc);
1044         vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
1045         vc->vc_uni_pagedir = NULL;
1046         vc->vc_hi_font_mask = 0;
1047         vc->vc_complement_mask = 0;
1048         vc->vc_can_do_color = 0;
1049         vc->vc_panic_force_write = false;
1050         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1051         vc->vc_sw->con_init(vc, init);
1052         if (!vc->vc_complement_mask)
1053                 vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1054         vc->vc_s_complement_mask = vc->vc_complement_mask;
1055         vc->vc_size_row = vc->vc_cols << 1;
1056         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1057 }
1058
1059 int vc_allocate(unsigned int currcons)  /* return 0 on success */
1060 {
1061         struct vt_notifier_param param;
1062         struct vc_data *vc;
1063
1064         WARN_CONSOLE_UNLOCKED();
1065
1066         if (currcons >= MAX_NR_CONSOLES)
1067                 return -ENXIO;
1068
1069         if (vc_cons[currcons].d)
1070                 return 0;
1071
1072         /* due to the granularity of kmalloc, we waste some memory here */
1073         /* the alloc is done in two steps, to optimize the common situation
1074            of a 25x80 console (structsize=216, screenbuf_size=4000) */
1075         /* although the numbers above are not valid since long ago, the
1076            point is still up-to-date and the comment still has its value
1077            even if only as a historical artifact.  --mj, July 1998 */
1078         param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1079         if (!vc)
1080                 return -ENOMEM;
1081
1082         vc_cons[currcons].d = vc;
1083         tty_port_init(&vc->port);
1084         INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1085
1086         visual_init(vc, currcons, 1);
1087
1088         if (!*vc->vc_uni_pagedir_loc)
1089                 con_set_default_unimap(vc);
1090
1091         vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
1092         if (!vc->vc_screenbuf)
1093                 goto err_free;
1094
1095         /* If no drivers have overridden us and the user didn't pass a
1096            boot option, default to displaying the cursor */
1097         if (global_cursor_default == -1)
1098                 global_cursor_default = 1;
1099
1100         vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
1101         vcs_make_sysfs(currcons);
1102         atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
1103
1104         return 0;
1105 err_free:
1106         kfree(vc);
1107         vc_cons[currcons].d = NULL;
1108         return -ENOMEM;
1109 }
1110
1111 static inline int resize_screen(struct vc_data *vc, int width, int height,
1112                                 int user)
1113 {
1114         /* Resizes the resolution of the display adapater */
1115         int err = 0;
1116
1117         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
1118                 err = vc->vc_sw->con_resize(vc, width, height, user);
1119
1120         return err;
1121 }
1122
1123 /*
1124  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1125  * [this is to be used together with some user program
1126  * like resize that changes the hardware videomode]
1127  */
1128 #define VC_RESIZE_MAXCOL (32767)
1129 #define VC_RESIZE_MAXROW (32767)
1130
1131 /**
1132  *      vc_do_resize    -       resizing method for the tty
1133  *      @tty: tty being resized
1134  *      @real_tty: real tty (different to tty if a pty/tty pair)
1135  *      @vc: virtual console private data
1136  *      @cols: columns
1137  *      @lines: lines
1138  *
1139  *      Resize a virtual console, clipping according to the actual constraints.
1140  *      If the caller passes a tty structure then update the termios winsize
1141  *      information and perform any necessary signal handling.
1142  *
1143  *      Caller must hold the console semaphore. Takes the termios rwsem and
1144  *      ctrl_lock of the tty IFF a tty is passed.
1145  */
1146
1147 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1148                                 unsigned int cols, unsigned int lines)
1149 {
1150         unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1151         unsigned long end;
1152         unsigned int old_rows, old_row_size, first_copied_row;
1153         unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1154         unsigned int user;
1155         unsigned short *newscreen;
1156         struct uni_screen *new_uniscr = NULL;
1157
1158         WARN_CONSOLE_UNLOCKED();
1159
1160         if (!vc)
1161                 return -ENXIO;
1162
1163         user = vc->vc_resize_user;
1164         vc->vc_resize_user = 0;
1165
1166         if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
1167                 return -EINVAL;
1168
1169         new_cols = (cols ? cols : vc->vc_cols);
1170         new_rows = (lines ? lines : vc->vc_rows);
1171         new_row_size = new_cols << 1;
1172         new_screen_size = new_row_size * new_rows;
1173
1174         if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
1175                 return 0;
1176
1177         if (new_screen_size > (4 << 20))
1178                 return -EINVAL;
1179         newscreen = kzalloc(new_screen_size, GFP_USER);
1180         if (!newscreen)
1181                 return -ENOMEM;
1182
1183         if (get_vc_uniscr(vc)) {
1184                 new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1185                 if (!new_uniscr) {
1186                         kfree(newscreen);
1187                         return -ENOMEM;
1188                 }
1189         }
1190
1191         if (vc == sel_cons)
1192                 clear_selection();
1193
1194         old_rows = vc->vc_rows;
1195         old_row_size = vc->vc_size_row;
1196
1197         err = resize_screen(vc, new_cols, new_rows, user);
1198         if (err) {
1199                 kfree(newscreen);
1200                 kfree(new_uniscr);
1201                 return err;
1202         }
1203
1204         vc->vc_rows = new_rows;
1205         vc->vc_cols = new_cols;
1206         vc->vc_size_row = new_row_size;
1207         vc->vc_screenbuf_size = new_screen_size;
1208
1209         rlth = min(old_row_size, new_row_size);
1210         rrem = new_row_size - rlth;
1211         old_origin = vc->vc_origin;
1212         new_origin = (long) newscreen;
1213         new_scr_end = new_origin + new_screen_size;
1214
1215         if (vc->vc_y > new_rows) {
1216                 if (old_rows - vc->vc_y < new_rows) {
1217                         /*
1218                          * Cursor near the bottom, copy contents from the
1219                          * bottom of buffer
1220                          */
1221                         first_copied_row = (old_rows - new_rows);
1222                 } else {
1223                         /*
1224                          * Cursor is in no man's land, copy 1/2 screenful
1225                          * from the top and bottom of cursor position
1226                          */
1227                         first_copied_row = (vc->vc_y - new_rows/2);
1228                 }
1229                 old_origin += first_copied_row * old_row_size;
1230         } else
1231                 first_copied_row = 0;
1232         end = old_origin + old_row_size * min(old_rows, new_rows);
1233
1234         vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1235                             get_vc_uniscr(vc), rlth/2, first_copied_row,
1236                             min(old_rows, new_rows));
1237         vc_uniscr_set(vc, new_uniscr);
1238
1239         update_attr(vc);
1240
1241         while (old_origin < end) {
1242                 scr_memcpyw((unsigned short *) new_origin,
1243                             (unsigned short *) old_origin, rlth);
1244                 if (rrem)
1245                         scr_memsetw((void *)(new_origin + rlth),
1246                                     vc->vc_video_erase_char, rrem);
1247                 old_origin += old_row_size;
1248                 new_origin += new_row_size;
1249         }
1250         if (new_scr_end > new_origin)
1251                 scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1252                             new_scr_end - new_origin);
1253         kfree(vc->vc_screenbuf);
1254         vc->vc_screenbuf = newscreen;
1255         vc->vc_screenbuf_size = new_screen_size;
1256         set_origin(vc);
1257
1258         /* do part of a reset_terminal() */
1259         vc->vc_top = 0;
1260         vc->vc_bottom = vc->vc_rows;
1261         gotoxy(vc, vc->vc_x, vc->vc_y);
1262         save_cur(vc);
1263
1264         if (tty) {
1265                 /* Rewrite the requested winsize data with the actual
1266                    resulting sizes */
1267                 struct winsize ws;
1268                 memset(&ws, 0, sizeof(ws));
1269                 ws.ws_row = vc->vc_rows;
1270                 ws.ws_col = vc->vc_cols;
1271                 ws.ws_ypixel = vc->vc_scan_lines;
1272                 tty_do_resize(tty, &ws);
1273         }
1274
1275         if (con_is_visible(vc))
1276                 update_screen(vc);
1277         vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1278         return err;
1279 }
1280
1281 /**
1282  *      vc_resize               -       resize a VT
1283  *      @vc: virtual console
1284  *      @cols: columns
1285  *      @rows: rows
1286  *
1287  *      Resize a virtual console as seen from the console end of things. We
1288  *      use the common vc_do_resize methods to update the structures. The
1289  *      caller must hold the console sem to protect console internals and
1290  *      vc->port.tty
1291  */
1292
1293 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1294 {
1295         return vc_do_resize(vc->port.tty, vc, cols, rows);
1296 }
1297
1298 /**
1299  *      vt_resize               -       resize a VT
1300  *      @tty: tty to resize
1301  *      @ws: winsize attributes
1302  *
1303  *      Resize a virtual terminal. This is called by the tty layer as we
1304  *      register our own handler for resizing. The mutual helper does all
1305  *      the actual work.
1306  *
1307  *      Takes the console sem and the called methods then take the tty
1308  *      termios_rwsem and the tty ctrl_lock in that order.
1309  */
1310 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1311 {
1312         struct vc_data *vc = tty->driver_data;
1313         int ret;
1314
1315         console_lock();
1316         ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1317         console_unlock();
1318         return ret;
1319 }
1320
1321 struct vc_data *vc_deallocate(unsigned int currcons)
1322 {
1323         struct vc_data *vc = NULL;
1324
1325         WARN_CONSOLE_UNLOCKED();
1326
1327         if (vc_cons_allocated(currcons)) {
1328                 struct vt_notifier_param param;
1329
1330                 param.vc = vc = vc_cons[currcons].d;
1331                 atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1332                 vcs_remove_sysfs(currcons);
1333                 vc->vc_sw->con_deinit(vc);
1334                 put_pid(vc->vt_pid);
1335                 module_put(vc->vc_sw->owner);
1336                 vc_uniscr_set(vc, NULL);
1337                 kfree(vc->vc_screenbuf);
1338                 vc_cons[currcons].d = NULL;
1339         }
1340         return vc;
1341 }
1342
1343 /*
1344  *      VT102 emulator
1345  */
1346
1347 #define set_kbd(vc, x)  vt_set_kbd_mode_bit((vc)->vc_num, (x))
1348 #define clr_kbd(vc, x)  vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1349 #define is_kbd(vc, x)   vt_get_kbd_mode_bit((vc)->vc_num, (x))
1350
1351 #define decarm          VC_REPEAT
1352 #define decckm          VC_CKMODE
1353 #define kbdapplic       VC_APPLIC
1354 #define lnm             VC_CRLF
1355
1356 /*
1357  * this is what the terminal answers to a ESC-Z or csi0c query.
1358  */
1359 #define VT100ID "\033[?1;2c"
1360 #define VT102ID "\033[?6c"
1361
1362 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1363                                        8,12,10,14, 9,13,11,15 };
1364
1365 /* the default colour table, for VGA+ colour systems */
1366 unsigned char default_red[] = {
1367         0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1368         0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1369 };
1370 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1371
1372 unsigned char default_grn[] = {
1373         0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1374         0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1375 };
1376 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1377
1378 unsigned char default_blu[] = {
1379         0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1380         0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1381 };
1382 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1383
1384 /*
1385  * gotoxy() must verify all boundaries, because the arguments
1386  * might also be negative. If the given position is out of
1387  * bounds, the cursor is placed at the nearest margin.
1388  */
1389 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1390 {
1391         int min_y, max_y;
1392
1393         if (new_x < 0)
1394                 vc->vc_x = 0;
1395         else {
1396                 if (new_x >= vc->vc_cols)
1397                         vc->vc_x = vc->vc_cols - 1;
1398                 else
1399                         vc->vc_x = new_x;
1400         }
1401
1402         if (vc->vc_decom) {
1403                 min_y = vc->vc_top;
1404                 max_y = vc->vc_bottom;
1405         } else {
1406                 min_y = 0;
1407                 max_y = vc->vc_rows;
1408         }
1409         if (new_y < min_y)
1410                 vc->vc_y = min_y;
1411         else if (new_y >= max_y)
1412                 vc->vc_y = max_y - 1;
1413         else
1414                 vc->vc_y = new_y;
1415         vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
1416         vc->vc_need_wrap = 0;
1417 }
1418
1419 /* for absolute user moves, when decom is set */
1420 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1421 {
1422         gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1423 }
1424
1425 void scrollback(struct vc_data *vc)
1426 {
1427         scrolldelta(-(vc->vc_rows / 2));
1428 }
1429
1430 void scrollfront(struct vc_data *vc, int lines)
1431 {
1432         if (!lines)
1433                 lines = vc->vc_rows / 2;
1434         scrolldelta(lines);
1435 }
1436
1437 static void lf(struct vc_data *vc)
1438 {
1439         /* don't scroll if above bottom of scrolling region, or
1440          * if below scrolling region
1441          */
1442         if (vc->vc_y + 1 == vc->vc_bottom)
1443                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1444         else if (vc->vc_y < vc->vc_rows - 1) {
1445                 vc->vc_y++;
1446                 vc->vc_pos += vc->vc_size_row;
1447         }
1448         vc->vc_need_wrap = 0;
1449         notify_write(vc, '\n');
1450 }
1451
1452 static void ri(struct vc_data *vc)
1453 {
1454         /* don't scroll if below top of scrolling region, or
1455          * if above scrolling region
1456          */
1457         if (vc->vc_y == vc->vc_top)
1458                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1459         else if (vc->vc_y > 0) {
1460                 vc->vc_y--;
1461                 vc->vc_pos -= vc->vc_size_row;
1462         }
1463         vc->vc_need_wrap = 0;
1464 }
1465
1466 static inline void cr(struct vc_data *vc)
1467 {
1468         vc->vc_pos -= vc->vc_x << 1;
1469         vc->vc_need_wrap = vc->vc_x = 0;
1470         notify_write(vc, '\r');
1471 }
1472
1473 static inline void bs(struct vc_data *vc)
1474 {
1475         if (vc->vc_x) {
1476                 vc->vc_pos -= 2;
1477                 vc->vc_x--;
1478                 vc->vc_need_wrap = 0;
1479                 notify_write(vc, '\b');
1480         }
1481 }
1482
1483 static inline void del(struct vc_data *vc)
1484 {
1485         /* ignored */
1486 }
1487
1488 static void csi_J(struct vc_data *vc, int vpar)
1489 {
1490         unsigned int count;
1491         unsigned short * start;
1492
1493         switch (vpar) {
1494                 case 0: /* erase from cursor to end of display */
1495                         vc_uniscr_clear_line(vc, vc->vc_x,
1496                                              vc->vc_cols - vc->vc_x);
1497                         vc_uniscr_clear_lines(vc, vc->vc_y + 1,
1498                                               vc->vc_rows - vc->vc_y - 1);
1499                         count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1500                         start = (unsigned short *)vc->vc_pos;
1501                         break;
1502                 case 1: /* erase from start to cursor */
1503                         vc_uniscr_clear_line(vc, 0, vc->vc_x + 1);
1504                         vc_uniscr_clear_lines(vc, 0, vc->vc_y);
1505                         count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1506                         start = (unsigned short *)vc->vc_origin;
1507                         break;
1508                 case 2: /* erase whole display */
1509                 case 3: /* (and scrollback buffer later) */
1510                         vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1511                         count = vc->vc_cols * vc->vc_rows;
1512                         start = (unsigned short *)vc->vc_origin;
1513                         break;
1514                 default:
1515                         return;
1516         }
1517         scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1518         if (vpar == 3) {
1519                 set_origin(vc);
1520                 flush_scrollback(vc);
1521                 if (con_is_visible(vc))
1522                         update_screen(vc);
1523         } else if (con_should_update(vc))
1524                 do_update_region(vc, (unsigned long) start, count);
1525         vc->vc_need_wrap = 0;
1526 }
1527
1528 static void csi_K(struct vc_data *vc, int vpar)
1529 {
1530         unsigned int count;
1531         unsigned short *start = (unsigned short *)vc->vc_pos;
1532         int offset;
1533
1534         switch (vpar) {
1535                 case 0: /* erase from cursor to end of line */
1536                         offset = 0;
1537                         count = vc->vc_cols - vc->vc_x;
1538                         break;
1539                 case 1: /* erase from start of line to cursor */
1540                         offset = -vc->vc_x;
1541                         count = vc->vc_x + 1;
1542                         break;
1543                 case 2: /* erase whole line */
1544                         offset = -vc->vc_x;
1545                         count = vc->vc_cols;
1546                         break;
1547                 default:
1548                         return;
1549         }
1550         vc_uniscr_clear_line(vc, vc->vc_x + offset, count);
1551         scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1552         vc->vc_need_wrap = 0;
1553         if (con_should_update(vc))
1554                 do_update_region(vc, (unsigned long) start, count);
1555 }
1556
1557 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
1558 {                                         /* not vt100? */
1559         int count;
1560
1561         if (!vpar)
1562                 vpar++;
1563         count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
1564
1565         vc_uniscr_clear_line(vc, vc->vc_x, count);
1566         scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1567         if (con_should_update(vc))
1568                 vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
1569         vc->vc_need_wrap = 0;
1570 }
1571
1572 static void default_attr(struct vc_data *vc)
1573 {
1574         vc->vc_intensity = 1;
1575         vc->vc_italic = 0;
1576         vc->vc_underline = 0;
1577         vc->vc_reverse = 0;
1578         vc->vc_blink = 0;
1579         vc->vc_color = vc->vc_def_color;
1580 }
1581
1582 struct rgb { u8 r; u8 g; u8 b; };
1583
1584 static void rgb_from_256(int i, struct rgb *c)
1585 {
1586         if (i < 8) {            /* Standard colours. */
1587                 c->r = i&1 ? 0xaa : 0x00;
1588                 c->g = i&2 ? 0xaa : 0x00;
1589                 c->b = i&4 ? 0xaa : 0x00;
1590         } else if (i < 16) {
1591                 c->r = i&1 ? 0xff : 0x55;
1592                 c->g = i&2 ? 0xff : 0x55;
1593                 c->b = i&4 ? 0xff : 0x55;
1594         } else if (i < 232) {   /* 6x6x6 colour cube. */
1595                 c->r = (i - 16) / 36 * 85 / 2;
1596                 c->g = (i - 16) / 6 % 6 * 85 / 2;
1597                 c->b = (i - 16) % 6 * 85 / 2;
1598         } else                  /* Grayscale ramp. */
1599                 c->r = c->g = c->b = i * 10 - 2312;
1600 }
1601
1602 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1603 {
1604         u8 hue = 0, max = max3(c->r, c->g, c->b);
1605
1606         if (c->r > max / 2)
1607                 hue |= 4;
1608         if (c->g > max / 2)
1609                 hue |= 2;
1610         if (c->b > max / 2)
1611                 hue |= 1;
1612
1613         if (hue == 7 && max <= 0x55) {
1614                 hue = 0;
1615                 vc->vc_intensity = 2;
1616         } else if (max > 0xaa)
1617                 vc->vc_intensity = 2;
1618         else
1619                 vc->vc_intensity = 1;
1620
1621         vc->vc_color = (vc->vc_color & 0xf0) | hue;
1622 }
1623
1624 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1625 {
1626         /* For backgrounds, err on the dark side. */
1627         vc->vc_color = (vc->vc_color & 0x0f)
1628                 | (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1629 }
1630
1631 /*
1632  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1633  * and thus need to be detected and ignored by hand. Strictly speaking, that
1634  * standard also wants : rather than ; as separators, contrary to ECMA-48, but
1635  * no one produces such codes and almost no one accepts them.
1636  *
1637  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1638  * supporting them.
1639  */
1640 static int vc_t416_color(struct vc_data *vc, int i,
1641                 void(*set_color)(struct vc_data *vc, const struct rgb *c))
1642 {
1643         struct rgb c;
1644
1645         i++;
1646         if (i > vc->vc_npar)
1647                 return i;
1648
1649         if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1650                 /* 256 colours */
1651                 i++;
1652                 rgb_from_256(vc->vc_par[i], &c);
1653         } else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1654                 /* 24 bit */
1655                 c.r = vc->vc_par[i + 1];
1656                 c.g = vc->vc_par[i + 2];
1657                 c.b = vc->vc_par[i + 3];
1658                 i += 3;
1659         } else
1660                 return i;
1661
1662         set_color(vc, &c);
1663
1664         return i;
1665 }
1666
1667 /* console_lock is held */
1668 static void csi_m(struct vc_data *vc)
1669 {
1670         int i;
1671
1672         for (i = 0; i <= vc->vc_npar; i++)
1673                 switch (vc->vc_par[i]) {
1674                 case 0: /* all attributes off */
1675                         default_attr(vc);
1676                         break;
1677                 case 1:
1678                         vc->vc_intensity = 2;
1679                         break;
1680                 case 2:
1681                         vc->vc_intensity = 0;
1682                         break;
1683                 case 3:
1684                         vc->vc_italic = 1;
1685                         break;
1686                 case 21:
1687                         /*
1688                          * No console drivers support double underline, so
1689                          * convert it to a single underline.
1690                          */
1691                 case 4:
1692                         vc->vc_underline = 1;
1693                         break;
1694                 case 5:
1695                         vc->vc_blink = 1;
1696                         break;
1697                 case 7:
1698                         vc->vc_reverse = 1;
1699                         break;
1700                 case 10: /* ANSI X3.64-1979 (SCO-ish?)
1701                           * Select primary font, don't display control chars if
1702                           * defined, don't set bit 8 on output.
1703                           */
1704                         vc->vc_translate = set_translate(vc->vc_charset == 0
1705                                         ? vc->vc_G0_charset
1706                                         : vc->vc_G1_charset, vc);
1707                         vc->vc_disp_ctrl = 0;
1708                         vc->vc_toggle_meta = 0;
1709                         break;
1710                 case 11: /* ANSI X3.64-1979 (SCO-ish?)
1711                           * Select first alternate font, lets chars < 32 be
1712                           * displayed as ROM chars.
1713                           */
1714                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1715                         vc->vc_disp_ctrl = 1;
1716                         vc->vc_toggle_meta = 0;
1717                         break;
1718                 case 12: /* ANSI X3.64-1979 (SCO-ish?)
1719                           * Select second alternate font, toggle high bit
1720                           * before displaying as ROM char.
1721                           */
1722                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1723                         vc->vc_disp_ctrl = 1;
1724                         vc->vc_toggle_meta = 1;
1725                         break;
1726                 case 22:
1727                         vc->vc_intensity = 1;
1728                         break;
1729                 case 23:
1730                         vc->vc_italic = 0;
1731                         break;
1732                 case 24:
1733                         vc->vc_underline = 0;
1734                         break;
1735                 case 25:
1736                         vc->vc_blink = 0;
1737                         break;
1738                 case 27:
1739                         vc->vc_reverse = 0;
1740                         break;
1741                 case 38:
1742                         i = vc_t416_color(vc, i, rgb_foreground);
1743                         break;
1744                 case 48:
1745                         i = vc_t416_color(vc, i, rgb_background);
1746                         break;
1747                 case 39:
1748                         vc->vc_color = (vc->vc_def_color & 0x0f) |
1749                                 (vc->vc_color & 0xf0);
1750                         break;
1751                 case 49:
1752                         vc->vc_color = (vc->vc_def_color & 0xf0) |
1753                                 (vc->vc_color & 0x0f);
1754                         break;
1755                 default:
1756                         if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1757                                 if (vc->vc_par[i] < 100)
1758                                         vc->vc_intensity = 2;
1759                                 vc->vc_par[i] -= 60;
1760                         }
1761                         if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1762                                 vc->vc_color = color_table[vc->vc_par[i] - 30]
1763                                         | (vc->vc_color & 0xf0);
1764                         else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1765                                 vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
1766                                         | (vc->vc_color & 0x0f);
1767                         break;
1768                 }
1769         update_attr(vc);
1770 }
1771
1772 static void respond_string(const char *p, struct tty_port *port)
1773 {
1774         while (*p) {
1775                 tty_insert_flip_char(port, *p, 0);
1776                 p++;
1777         }
1778         tty_schedule_flip(port);
1779 }
1780
1781 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1782 {
1783         char buf[40];
1784
1785         sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
1786         respond_string(buf, tty->port);
1787 }
1788
1789 static inline void status_report(struct tty_struct *tty)
1790 {
1791         respond_string("\033[0n", tty->port);   /* Terminal ok */
1792 }
1793
1794 static inline void respond_ID(struct tty_struct *tty)
1795 {
1796         respond_string(VT102ID, tty->port);
1797 }
1798
1799 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1800 {
1801         char buf[8];
1802
1803         sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
1804                 (char)('!' + mry));
1805         respond_string(buf, tty->port);
1806 }
1807
1808 /* invoked via ioctl(TIOCLINUX) and through set_selection */
1809 int mouse_reporting(void)
1810 {
1811         return vc_cons[fg_console].d->vc_report_mouse;
1812 }
1813
1814 /* console_lock is held */
1815 static void set_mode(struct vc_data *vc, int on_off)
1816 {
1817         int i;
1818
1819         for (i = 0; i <= vc->vc_npar; i++)
1820                 if (vc->vc_ques) {
1821                         switch(vc->vc_par[i]) { /* DEC private modes set/reset */
1822                         case 1:                 /* Cursor keys send ^[Ox/^[[x */
1823                                 if (on_off)
1824                                         set_kbd(vc, decckm);
1825                                 else
1826                                         clr_kbd(vc, decckm);
1827                                 break;
1828                         case 3: /* 80/132 mode switch unimplemented */
1829 #if 0
1830                                 vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1831                                 /* this alone does not suffice; some user mode
1832                                    utility has to change the hardware regs */
1833 #endif
1834                                 break;
1835                         case 5:                 /* Inverted screen on/off */
1836                                 if (vc->vc_decscnm != on_off) {
1837                                         vc->vc_decscnm = on_off;
1838                                         invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
1839                                         update_attr(vc);
1840                                 }
1841                                 break;
1842                         case 6:                 /* Origin relative/absolute */
1843                                 vc->vc_decom = on_off;
1844                                 gotoxay(vc, 0, 0);
1845                                 break;
1846                         case 7:                 /* Autowrap on/off */
1847                                 vc->vc_decawm = on_off;
1848                                 break;
1849                         case 8:                 /* Autorepeat on/off */
1850                                 if (on_off)
1851                                         set_kbd(vc, decarm);
1852                                 else
1853                                         clr_kbd(vc, decarm);
1854                                 break;
1855                         case 9:
1856                                 vc->vc_report_mouse = on_off ? 1 : 0;
1857                                 break;
1858                         case 25:                /* Cursor on/off */
1859                                 vc->vc_deccm = on_off;
1860                                 break;
1861                         case 1000:
1862                                 vc->vc_report_mouse = on_off ? 2 : 0;
1863                                 break;
1864                         }
1865                 } else {
1866                         switch(vc->vc_par[i]) { /* ANSI modes set/reset */
1867                         case 3:                 /* Monitor (display ctrls) */
1868                                 vc->vc_disp_ctrl = on_off;
1869                                 break;
1870                         case 4:                 /* Insert Mode on/off */
1871                                 vc->vc_decim = on_off;
1872                                 break;
1873                         case 20:                /* Lf, Enter == CrLf/Lf */
1874                                 if (on_off)
1875                                         set_kbd(vc, lnm);
1876                                 else
1877                                         clr_kbd(vc, lnm);
1878                                 break;
1879                         }
1880                 }
1881 }
1882
1883 /* console_lock is held */
1884 static void setterm_command(struct vc_data *vc)
1885 {
1886         switch(vc->vc_par[0]) {
1887                 case 1: /* set color for underline mode */
1888                         if (vc->vc_can_do_color &&
1889                                         vc->vc_par[1] < 16) {
1890                                 vc->vc_ulcolor = color_table[vc->vc_par[1]];
1891                                 if (vc->vc_underline)
1892                                         update_attr(vc);
1893                         }
1894                         break;
1895                 case 2: /* set color for half intensity mode */
1896                         if (vc->vc_can_do_color &&
1897                                         vc->vc_par[1] < 16) {
1898                                 vc->vc_halfcolor = color_table[vc->vc_par[1]];
1899                                 if (vc->vc_intensity == 0)
1900                                         update_attr(vc);
1901                         }
1902                         break;
1903                 case 8: /* store colors as defaults */
1904                         vc->vc_def_color = vc->vc_attr;
1905                         if (vc->vc_hi_font_mask == 0x100)
1906                                 vc->vc_def_color >>= 1;
1907                         default_attr(vc);
1908                         update_attr(vc);
1909                         break;
1910                 case 9: /* set blanking interval */
1911                         blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
1912                         poke_blanked_console();
1913                         break;
1914                 case 10: /* set bell frequency in Hz */
1915                         if (vc->vc_npar >= 1)
1916                                 vc->vc_bell_pitch = vc->vc_par[1];
1917                         else
1918                                 vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1919                         break;
1920                 case 11: /* set bell duration in msec */
1921                         if (vc->vc_npar >= 1)
1922                                 vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1923                                         msecs_to_jiffies(vc->vc_par[1]) : 0;
1924                         else
1925                                 vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1926                         break;
1927                 case 12: /* bring specified console to the front */
1928                         if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1929                                 set_console(vc->vc_par[1] - 1);
1930                         break;
1931                 case 13: /* unblank the screen */
1932                         poke_blanked_console();
1933                         break;
1934                 case 14: /* set vesa powerdown interval */
1935                         vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
1936                         break;
1937                 case 15: /* activate the previous console */
1938                         set_console(last_console);
1939                         break;
1940                 case 16: /* set cursor blink duration in msec */
1941                         if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1942                                         vc->vc_par[1] <= USHRT_MAX)
1943                                 vc->vc_cur_blink_ms = vc->vc_par[1];
1944                         else
1945                                 vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1946                         break;
1947         }
1948 }
1949
1950 /* console_lock is held */
1951 static void csi_at(struct vc_data *vc, unsigned int nr)
1952 {
1953         if (nr > vc->vc_cols - vc->vc_x)
1954                 nr = vc->vc_cols - vc->vc_x;
1955         else if (!nr)
1956                 nr = 1;
1957         insert_char(vc, nr);
1958 }
1959
1960 /* console_lock is held */
1961 static void csi_L(struct vc_data *vc, unsigned int nr)
1962 {
1963         if (nr > vc->vc_rows - vc->vc_y)
1964                 nr = vc->vc_rows - vc->vc_y;
1965         else if (!nr)
1966                 nr = 1;
1967         con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_DOWN, nr);
1968         vc->vc_need_wrap = 0;
1969 }
1970
1971 /* console_lock is held */
1972 static void csi_P(struct vc_data *vc, unsigned int nr)
1973 {
1974         if (nr > vc->vc_cols - vc->vc_x)
1975                 nr = vc->vc_cols - vc->vc_x;
1976         else if (!nr)
1977                 nr = 1;
1978         delete_char(vc, nr);
1979 }
1980
1981 /* console_lock is held */
1982 static void csi_M(struct vc_data *vc, unsigned int nr)
1983 {
1984         if (nr > vc->vc_rows - vc->vc_y)
1985                 nr = vc->vc_rows - vc->vc_y;
1986         else if (!nr)
1987                 nr=1;
1988         con_scroll(vc, vc->vc_y, vc->vc_bottom, SM_UP, nr);
1989         vc->vc_need_wrap = 0;
1990 }
1991
1992 /* console_lock is held (except via vc_init->reset_terminal */
1993 static void save_cur(struct vc_data *vc)
1994 {
1995         vc->vc_saved_x          = vc->vc_x;
1996         vc->vc_saved_y          = vc->vc_y;
1997         vc->vc_s_intensity      = vc->vc_intensity;
1998         vc->vc_s_italic         = vc->vc_italic;
1999         vc->vc_s_underline      = vc->vc_underline;
2000         vc->vc_s_blink          = vc->vc_blink;
2001         vc->vc_s_reverse        = vc->vc_reverse;
2002         vc->vc_s_charset        = vc->vc_charset;
2003         vc->vc_s_color          = vc->vc_color;
2004         vc->vc_saved_G0         = vc->vc_G0_charset;
2005         vc->vc_saved_G1         = vc->vc_G1_charset;
2006 }
2007
2008 /* console_lock is held */
2009 static void restore_cur(struct vc_data *vc)
2010 {
2011         gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
2012         vc->vc_intensity        = vc->vc_s_intensity;
2013         vc->vc_italic           = vc->vc_s_italic;
2014         vc->vc_underline        = vc->vc_s_underline;
2015         vc->vc_blink            = vc->vc_s_blink;
2016         vc->vc_reverse          = vc->vc_s_reverse;
2017         vc->vc_charset          = vc->vc_s_charset;
2018         vc->vc_color            = vc->vc_s_color;
2019         vc->vc_G0_charset       = vc->vc_saved_G0;
2020         vc->vc_G1_charset       = vc->vc_saved_G1;
2021         vc->vc_translate        = set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
2022         update_attr(vc);
2023         vc->vc_need_wrap = 0;
2024 }
2025
2026 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2027         EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
2028         ESpalette, ESosc };
2029
2030 /* console_lock is held (except via vc_init()) */
2031 static void reset_terminal(struct vc_data *vc, int do_clear)
2032 {
2033         vc->vc_top              = 0;
2034         vc->vc_bottom           = vc->vc_rows;
2035         vc->vc_state            = ESnormal;
2036         vc->vc_ques             = 0;
2037         vc->vc_translate        = set_translate(LAT1_MAP, vc);
2038         vc->vc_G0_charset       = LAT1_MAP;
2039         vc->vc_G1_charset       = GRAF_MAP;
2040         vc->vc_charset          = 0;
2041         vc->vc_need_wrap        = 0;
2042         vc->vc_report_mouse     = 0;
2043         vc->vc_utf              = default_utf8;
2044         vc->vc_utf_count        = 0;
2045
2046         vc->vc_disp_ctrl        = 0;
2047         vc->vc_toggle_meta      = 0;
2048
2049         vc->vc_decscnm          = 0;
2050         vc->vc_decom            = 0;
2051         vc->vc_decawm           = 1;
2052         vc->vc_deccm            = global_cursor_default;
2053         vc->vc_decim            = 0;
2054
2055         vt_reset_keyboard(vc->vc_num);
2056
2057         vc->vc_cursor_type = cur_default;
2058         vc->vc_complement_mask = vc->vc_s_complement_mask;
2059
2060         default_attr(vc);
2061         update_attr(vc);
2062
2063         vc->vc_tab_stop[0]      =
2064         vc->vc_tab_stop[1]      =
2065         vc->vc_tab_stop[2]      =
2066         vc->vc_tab_stop[3]      =
2067         vc->vc_tab_stop[4]      =
2068         vc->vc_tab_stop[5]      =
2069         vc->vc_tab_stop[6]      =
2070         vc->vc_tab_stop[7]      = 0x01010101;
2071
2072         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2073         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2074         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2075
2076         gotoxy(vc, 0, 0);
2077         save_cur(vc);
2078         if (do_clear)
2079             csi_J(vc, 2);
2080 }
2081
2082 /* console_lock is held */
2083 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2084 {
2085         /*
2086          *  Control characters can be used in the _middle_
2087          *  of an escape sequence.
2088          */
2089         if (vc->vc_state == ESosc && c>=8 && c<=13) /* ... except for OSC */
2090                 return;
2091         switch (c) {
2092         case 0:
2093                 return;
2094         case 7:
2095                 if (vc->vc_state == ESosc)
2096                         vc->vc_state = ESnormal;
2097                 else if (vc->vc_bell_duration)
2098                         kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2099                 return;
2100         case 8:
2101                 bs(vc);
2102                 return;
2103         case 9:
2104                 vc->vc_pos -= (vc->vc_x << 1);
2105                 while (vc->vc_x < vc->vc_cols - 1) {
2106                         vc->vc_x++;
2107                         if (vc->vc_tab_stop[7 & (vc->vc_x >> 5)] & (1 << (vc->vc_x & 31)))
2108                                 break;
2109                 }
2110                 vc->vc_pos += (vc->vc_x << 1);
2111                 notify_write(vc, '\t');
2112                 return;
2113         case 10: case 11: case 12:
2114                 lf(vc);
2115                 if (!is_kbd(vc, lnm))
2116                         return;
2117         case 13:
2118                 cr(vc);
2119                 return;
2120         case 14:
2121                 vc->vc_charset = 1;
2122                 vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2123                 vc->vc_disp_ctrl = 1;
2124                 return;
2125         case 15:
2126                 vc->vc_charset = 0;
2127                 vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2128                 vc->vc_disp_ctrl = 0;
2129                 return;
2130         case 24: case 26:
2131                 vc->vc_state = ESnormal;
2132                 return;
2133         case 27:
2134                 vc->vc_state = ESesc;
2135                 return;
2136         case 127:
2137                 del(vc);
2138                 return;
2139         case 128+27:
2140                 vc->vc_state = ESsquare;
2141                 return;
2142         }
2143         switch(vc->vc_state) {
2144         case ESesc:
2145                 vc->vc_state = ESnormal;
2146                 switch (c) {
2147                 case '[':
2148                         vc->vc_state = ESsquare;
2149                         return;
2150                 case ']':
2151                         vc->vc_state = ESnonstd;
2152                         return;
2153                 case '%':
2154                         vc->vc_state = ESpercent;
2155                         return;
2156                 case 'E':
2157                         cr(vc);
2158                         lf(vc);
2159                         return;
2160                 case 'M':
2161                         ri(vc);
2162                         return;
2163                 case 'D':
2164                         lf(vc);
2165                         return;
2166                 case 'H':
2167                         vc->vc_tab_stop[7 & (vc->vc_x >> 5)] |= (1 << (vc->vc_x & 31));
2168                         return;
2169                 case 'Z':
2170                         respond_ID(tty);
2171                         return;
2172                 case '7':
2173                         save_cur(vc);
2174                         return;
2175                 case '8':
2176                         restore_cur(vc);
2177                         return;
2178                 case '(':
2179                         vc->vc_state = ESsetG0;
2180                         return;
2181                 case ')':
2182                         vc->vc_state = ESsetG1;
2183                         return;
2184                 case '#':
2185                         vc->vc_state = EShash;
2186                         return;
2187                 case 'c':
2188                         reset_terminal(vc, 1);
2189                         return;
2190                 case '>':  /* Numeric keypad */
2191                         clr_kbd(vc, kbdapplic);
2192                         return;
2193                 case '=':  /* Appl. keypad */
2194                         set_kbd(vc, kbdapplic);
2195                         return;
2196                 }
2197                 return;
2198         case ESnonstd:
2199                 if (c=='P') {   /* palette escape sequence */
2200                         for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2201                                 vc->vc_par[vc->vc_npar] = 0;
2202                         vc->vc_npar = 0;
2203                         vc->vc_state = ESpalette;
2204                         return;
2205                 } else if (c=='R') {   /* reset palette */
2206                         reset_palette(vc);
2207                         vc->vc_state = ESnormal;
2208                 } else if (c>='0' && c<='9')
2209                         vc->vc_state = ESosc;
2210                 else
2211                         vc->vc_state = ESnormal;
2212                 return;
2213         case ESpalette:
2214                 if (isxdigit(c)) {
2215                         vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2216                         if (vc->vc_npar == 7) {
2217                                 int i = vc->vc_par[0] * 3, j = 1;
2218                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2219                                 vc->vc_palette[i++] += vc->vc_par[j++];
2220                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2221                                 vc->vc_palette[i++] += vc->vc_par[j++];
2222                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2223                                 vc->vc_palette[i] += vc->vc_par[j];
2224                                 set_palette(vc);
2225                                 vc->vc_state = ESnormal;
2226                         }
2227                 } else
2228                         vc->vc_state = ESnormal;
2229                 return;
2230         case ESsquare:
2231                 for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2232                         vc->vc_par[vc->vc_npar] = 0;
2233                 vc->vc_npar = 0;
2234                 vc->vc_state = ESgetpars;
2235                 if (c == '[') { /* Function key */
2236                         vc->vc_state=ESfunckey;
2237                         return;
2238                 }
2239                 vc->vc_ques = (c == '?');
2240                 if (vc->vc_ques)
2241                         return;
2242         case ESgetpars:
2243                 if (c == ';' && vc->vc_npar < NPAR - 1) {
2244                         vc->vc_npar++;
2245                         return;
2246                 } else if (c>='0' && c<='9') {
2247                         vc->vc_par[vc->vc_npar] *= 10;
2248                         vc->vc_par[vc->vc_npar] += c - '0';
2249                         return;
2250                 }
2251                 vc->vc_state = ESnormal;
2252                 switch(c) {
2253                 case 'h':
2254                         set_mode(vc, 1);
2255                         return;
2256                 case 'l':
2257                         set_mode(vc, 0);
2258                         return;
2259                 case 'c':
2260                         if (vc->vc_ques) {
2261                                 if (vc->vc_par[0])
2262                                         vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
2263                                 else
2264                                         vc->vc_cursor_type = cur_default;
2265                                 return;
2266                         }
2267                         break;
2268                 case 'm':
2269                         if (vc->vc_ques) {
2270                                 clear_selection();
2271                                 if (vc->vc_par[0])
2272                                         vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2273                                 else
2274                                         vc->vc_complement_mask = vc->vc_s_complement_mask;
2275                                 return;
2276                         }
2277                         break;
2278                 case 'n':
2279                         if (!vc->vc_ques) {
2280                                 if (vc->vc_par[0] == 5)
2281                                         status_report(tty);
2282                                 else if (vc->vc_par[0] == 6)
2283                                         cursor_report(vc, tty);
2284                         }
2285                         return;
2286                 }
2287                 if (vc->vc_ques) {
2288                         vc->vc_ques = 0;
2289                         return;
2290                 }
2291                 switch(c) {
2292                 case 'G': case '`':
2293                         if (vc->vc_par[0])
2294                                 vc->vc_par[0]--;
2295                         gotoxy(vc, vc->vc_par[0], vc->vc_y);
2296                         return;
2297                 case 'A':
2298                         if (!vc->vc_par[0])
2299                                 vc->vc_par[0]++;
2300                         gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
2301                         return;
2302                 case 'B': case 'e':
2303                         if (!vc->vc_par[0])
2304                                 vc->vc_par[0]++;
2305                         gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
2306                         return;
2307                 case 'C': case 'a':
2308                         if (!vc->vc_par[0])
2309                                 vc->vc_par[0]++;
2310                         gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
2311                         return;
2312                 case 'D':
2313                         if (!vc->vc_par[0])
2314                                 vc->vc_par[0]++;
2315                         gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
2316                         return;
2317                 case 'E':
2318                         if (!vc->vc_par[0])
2319                                 vc->vc_par[0]++;
2320                         gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
2321                         return;
2322                 case 'F':
2323                         if (!vc->vc_par[0])
2324                                 vc->vc_par[0]++;
2325                         gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
2326                         return;
2327                 case 'd':
2328                         if (vc->vc_par[0])
2329                                 vc->vc_par[0]--;
2330                         gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
2331                         return;
2332                 case 'H': case 'f':
2333                         if (vc->vc_par[0])
2334                                 vc->vc_par[0]--;
2335                         if (vc->vc_par[1])
2336                                 vc->vc_par[1]--;
2337                         gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2338                         return;
2339                 case 'J':
2340                         csi_J(vc, vc->vc_par[0]);
2341                         return;
2342                 case 'K':
2343                         csi_K(vc, vc->vc_par[0]);
2344                         return;
2345                 case 'L':
2346                         csi_L(vc, vc->vc_par[0]);
2347                         return;
2348                 case 'M':
2349                         csi_M(vc, vc->vc_par[0]);
2350                         return;
2351                 case 'P':
2352                         csi_P(vc, vc->vc_par[0]);
2353                         return;
2354                 case 'c':
2355                         if (!vc->vc_par[0])
2356                                 respond_ID(tty);
2357                         return;
2358                 case 'g':
2359                         if (!vc->vc_par[0])
2360                                 vc->vc_tab_stop[7 & (vc->vc_x >> 5)] &= ~(1 << (vc->vc_x & 31));
2361                         else if (vc->vc_par[0] == 3) {
2362                                 vc->vc_tab_stop[0] =
2363                                         vc->vc_tab_stop[1] =
2364                                         vc->vc_tab_stop[2] =
2365                                         vc->vc_tab_stop[3] =
2366                                         vc->vc_tab_stop[4] =
2367                                         vc->vc_tab_stop[5] =
2368                                         vc->vc_tab_stop[6] =
2369                                         vc->vc_tab_stop[7] = 0;
2370                         }
2371                         return;
2372                 case 'm':
2373                         csi_m(vc);
2374                         return;
2375                 case 'q': /* DECLL - but only 3 leds */
2376                         /* map 0,1,2,3 to 0,1,2,4 */
2377                         if (vc->vc_par[0] < 4)
2378                                 vt_set_led_state(vc->vc_num,
2379                                             (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2380                         return;
2381                 case 'r':
2382                         if (!vc->vc_par[0])
2383                                 vc->vc_par[0]++;
2384                         if (!vc->vc_par[1])
2385                                 vc->vc_par[1] = vc->vc_rows;
2386                         /* Minimum allowed region is 2 lines */
2387                         if (vc->vc_par[0] < vc->vc_par[1] &&
2388                             vc->vc_par[1] <= vc->vc_rows) {
2389                                 vc->vc_top = vc->vc_par[0] - 1;
2390                                 vc->vc_bottom = vc->vc_par[1];
2391                                 gotoxay(vc, 0, 0);
2392                         }
2393                         return;
2394                 case 's':
2395                         save_cur(vc);
2396                         return;
2397                 case 'u':
2398                         restore_cur(vc);
2399                         return;
2400                 case 'X':
2401                         csi_X(vc, vc->vc_par[0]);
2402                         return;
2403                 case '@':
2404                         csi_at(vc, vc->vc_par[0]);
2405                         return;
2406                 case ']': /* setterm functions */
2407                         setterm_command(vc);
2408                         return;
2409                 }
2410                 return;
2411         case ESpercent:
2412                 vc->vc_state = ESnormal;
2413                 switch (c) {
2414                 case '@':  /* defined in ISO 2022 */
2415                         vc->vc_utf = 0;
2416                         return;
2417                 case 'G':  /* prelim official escape code */
2418                 case '8':  /* retained for compatibility */
2419                         vc->vc_utf = 1;
2420                         return;
2421                 }
2422                 return;
2423         case ESfunckey:
2424                 vc->vc_state = ESnormal;
2425                 return;
2426         case EShash:
2427                 vc->vc_state = ESnormal;
2428                 if (c == '8') {
2429                         /* DEC screen alignment test. kludge :-) */
2430                         vc->vc_video_erase_char =
2431                                 (vc->vc_video_erase_char & 0xff00) | 'E';
2432                         csi_J(vc, 2);
2433                         vc->vc_video_erase_char =
2434                                 (vc->vc_video_erase_char & 0xff00) | ' ';
2435                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2436                 }
2437                 return;
2438         case ESsetG0:
2439                 if (c == '0')
2440                         vc->vc_G0_charset = GRAF_MAP;
2441                 else if (c == 'B')
2442                         vc->vc_G0_charset = LAT1_MAP;
2443                 else if (c == 'U')
2444                         vc->vc_G0_charset = IBMPC_MAP;
2445                 else if (c == 'K')
2446                         vc->vc_G0_charset = USER_MAP;
2447                 if (vc->vc_charset == 0)
2448                         vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
2449                 vc->vc_state = ESnormal;
2450                 return;
2451         case ESsetG1:
2452                 if (c == '0')
2453                         vc->vc_G1_charset = GRAF_MAP;
2454                 else if (c == 'B')
2455                         vc->vc_G1_charset = LAT1_MAP;
2456                 else if (c == 'U')
2457                         vc->vc_G1_charset = IBMPC_MAP;
2458                 else if (c == 'K')
2459                         vc->vc_G1_charset = USER_MAP;
2460                 if (vc->vc_charset == 1)
2461                         vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
2462                 vc->vc_state = ESnormal;
2463                 return;
2464         case ESosc:
2465                 return;
2466         default:
2467                 vc->vc_state = ESnormal;
2468         }
2469 }
2470
2471 /* is_double_width() is based on the wcwidth() implementation by
2472  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2473  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2474  */
2475 struct interval {
2476         uint32_t first;
2477         uint32_t last;
2478 };
2479
2480 static int ucs_cmp(const void *key, const void *elt)
2481 {
2482         uint32_t ucs = *(uint32_t *)key;
2483         struct interval e = *(struct interval *) elt;
2484
2485         if (ucs > e.last)
2486                 return 1;
2487         else if (ucs < e.first)
2488                 return -1;
2489         return 0;
2490 }
2491
2492 static int is_double_width(uint32_t ucs)
2493 {
2494         static const struct interval double_width[] = {
2495                 { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2496                 { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2497                 { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2498                 { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2499         };
2500         if (ucs < double_width[0].first ||
2501             ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2502                 return 0;
2503
2504         return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2505                         sizeof(struct interval), ucs_cmp) != NULL;
2506 }
2507
2508 static void con_flush(struct vc_data *vc, unsigned long draw_from,
2509                 unsigned long draw_to, int *draw_x)
2510 {
2511         if (*draw_x < 0)
2512                 return;
2513
2514         vc->vc_sw->con_putcs(vc, (u16 *)draw_from,
2515                         (u16 *)draw_to - (u16 *)draw_from, vc->vc_y, *draw_x);
2516         *draw_x = -1;
2517 }
2518
2519 /* acquires console_lock */
2520 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2521 {
2522         int c, next_c, tc, ok, n = 0, draw_x = -1;
2523         unsigned int currcons;
2524         unsigned long draw_from = 0, draw_to = 0;
2525         struct vc_data *vc;
2526         unsigned char vc_attr;
2527         struct vt_notifier_param param;
2528         uint8_t rescan;
2529         uint8_t inverse;
2530         uint8_t width;
2531         u16 himask, charmask;
2532
2533         if (in_interrupt())
2534                 return count;
2535
2536         might_sleep();
2537
2538         console_lock();
2539         vc = tty->driver_data;
2540         if (vc == NULL) {
2541                 pr_err("vt: argh, driver_data is NULL !\n");
2542                 console_unlock();
2543                 return 0;
2544         }
2545
2546         currcons = vc->vc_num;
2547         if (!vc_cons_allocated(currcons)) {
2548                 /* could this happen? */
2549                 pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2550                 console_unlock();
2551                 return 0;
2552         }
2553
2554         himask = vc->vc_hi_font_mask;
2555         charmask = himask ? 0x1ff : 0xff;
2556
2557         /* undraw cursor first */
2558         if (con_is_fg(vc))
2559                 hide_cursor(vc);
2560
2561         param.vc = vc;
2562
2563         while (!tty->stopped && count) {
2564                 int orig = *buf;
2565                 c = orig;
2566                 buf++;
2567                 n++;
2568                 count--;
2569                 rescan = 0;
2570                 inverse = 0;
2571                 width = 1;
2572
2573                 /* Do no translation at all in control states */
2574                 if (vc->vc_state != ESnormal) {
2575                         tc = c;
2576                 } else if (vc->vc_utf && !vc->vc_disp_ctrl) {
2577                     /* Combine UTF-8 into Unicode in vc_utf_char.
2578                      * vc_utf_count is the number of continuation bytes still
2579                      * expected to arrive.
2580                      * vc_npar is the number of continuation bytes arrived so
2581                      * far
2582                      */
2583 rescan_last_byte:
2584                     if ((c & 0xc0) == 0x80) {
2585                         /* Continuation byte received */
2586                         static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
2587                         if (vc->vc_utf_count) {
2588                             vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2589                             vc->vc_npar++;
2590                             if (--vc->vc_utf_count) {
2591                                 /* Still need some bytes */
2592                                 continue;
2593                             }
2594                             /* Got a whole character */
2595                             c = vc->vc_utf_char;
2596                             /* Reject overlong sequences */
2597                             if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2598                                         c > utf8_length_changes[vc->vc_npar])
2599                                 c = 0xfffd;
2600                         } else {
2601                             /* Unexpected continuation byte */
2602                             vc->vc_utf_count = 0;
2603                             c = 0xfffd;
2604                         }
2605                     } else {
2606                         /* Single ASCII byte or first byte of a sequence received */
2607                         if (vc->vc_utf_count) {
2608                             /* Continuation byte expected */
2609                             rescan = 1;
2610                             vc->vc_utf_count = 0;
2611                             c = 0xfffd;
2612                         } else if (c > 0x7f) {
2613                             /* First byte of a multibyte sequence received */
2614                             vc->vc_npar = 0;
2615                             if ((c & 0xe0) == 0xc0) {
2616                                 vc->vc_utf_count = 1;
2617                                 vc->vc_utf_char = (c & 0x1f);
2618                             } else if ((c & 0xf0) == 0xe0) {
2619                                 vc->vc_utf_count = 2;
2620                                 vc->vc_utf_char = (c & 0x0f);
2621                             } else if ((c & 0xf8) == 0xf0) {
2622                                 vc->vc_utf_count = 3;
2623                                 vc->vc_utf_char = (c & 0x07);
2624                             } else if ((c & 0xfc) == 0xf8) {
2625                                 vc->vc_utf_count = 4;
2626                                 vc->vc_utf_char = (c & 0x03);
2627                             } else if ((c & 0xfe) == 0xfc) {
2628                                 vc->vc_utf_count = 5;
2629                                 vc->vc_utf_char = (c & 0x01);
2630                             } else {
2631                                 /* 254 and 255 are invalid */
2632                                 c = 0xfffd;
2633                             }
2634                             if (vc->vc_utf_count) {
2635                                 /* Still need some bytes */
2636                                 continue;
2637                             }
2638                         }
2639                         /* Nothing to do if an ASCII byte was received */
2640                     }
2641                     /* End of UTF-8 decoding. */
2642                     /* c is the received character, or U+FFFD for invalid sequences. */
2643                     /* Replace invalid Unicode code points with U+FFFD too */
2644                     if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2645                         c = 0xfffd;
2646                     tc = c;
2647                 } else {        /* no utf or alternate charset mode */
2648                     tc = vc_translate(vc, c);
2649                 }
2650
2651                 param.c = tc;
2652                 if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2653                                         &param) == NOTIFY_STOP)
2654                         continue;
2655
2656                 /* If the original code was a control character we
2657                  * only allow a glyph to be displayed if the code is
2658                  * not normally used (such as for cursor movement) or
2659                  * if the disp_ctrl mode has been explicitly enabled.
2660                  * Certain characters (as given by the CTRL_ALWAYS
2661                  * bitmap) are always displayed as control characters,
2662                  * as the console would be pretty useless without
2663                  * them; to display an arbitrary font position use the
2664                  * direct-to-font zone in UTF-8 mode.
2665                  */
2666                 ok = tc && (c >= 32 ||
2667                             !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
2668                                   vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
2669                         && (c != 127 || vc->vc_disp_ctrl)
2670                         && (c != 128+27);
2671
2672                 if (vc->vc_state == ESnormal && ok) {
2673                         if (vc->vc_utf && !vc->vc_disp_ctrl) {
2674                                 if (is_double_width(c))
2675                                         width = 2;
2676                         }
2677                         /* Now try to find out how to display it */
2678                         tc = conv_uni_to_pc(vc, tc);
2679                         if (tc & ~charmask) {
2680                                 if (tc == -1 || tc == -2) {
2681                                     continue; /* nothing to display */
2682                                 }
2683                                 /* Glyph not found */
2684                                 if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
2685                                     /* In legacy mode use the glyph we get by a 1:1 mapping.
2686                                        This would make absolutely no sense with Unicode in mind,
2687                                        but do this for ASCII characters since a font may lack
2688                                        Unicode mapping info and we don't want to end up with
2689                                        having question marks only. */
2690                                     tc = c;
2691                                 } else {
2692                                     /* Display U+FFFD. If it's not found, display an inverse question mark. */
2693                                     tc = conv_uni_to_pc(vc, 0xfffd);
2694                                     if (tc < 0) {
2695                                         inverse = 1;
2696                                         tc = conv_uni_to_pc(vc, '?');
2697                                         if (tc < 0) tc = '?';
2698                                     }
2699                                 }
2700                         }
2701
2702                         if (!inverse) {
2703                                 vc_attr = vc->vc_attr;
2704                         } else {
2705                                 /* invert vc_attr */
2706                                 if (!vc->vc_can_do_color) {
2707                                         vc_attr = (vc->vc_attr) ^ 0x08;
2708                                 } else if (vc->vc_hi_font_mask == 0x100) {
2709                                         vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
2710                                 } else {
2711                                         vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
2712                                 }
2713                                 con_flush(vc, draw_from, draw_to, &draw_x);
2714                         }
2715
2716                         next_c = c;
2717                         while (1) {
2718                                 if (vc->vc_need_wrap || vc->vc_decim)
2719                                         con_flush(vc, draw_from, draw_to,
2720                                                         &draw_x);
2721                                 if (vc->vc_need_wrap) {
2722                                         cr(vc);
2723                                         lf(vc);
2724                                 }
2725                                 if (vc->vc_decim)
2726                                         insert_char(vc, 1);
2727                                 vc_uniscr_putc(vc, next_c);
2728                                 scr_writew(himask ?
2729                                              ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
2730                                              (vc_attr << 8) + tc,
2731                                            (u16 *) vc->vc_pos);
2732                                 if (con_should_update(vc) && draw_x < 0) {
2733                                         draw_x = vc->vc_x;
2734                                         draw_from = vc->vc_pos;
2735                                 }
2736                                 if (vc->vc_x == vc->vc_cols - 1) {
2737                                         vc->vc_need_wrap = vc->vc_decawm;
2738                                         draw_to = vc->vc_pos + 2;
2739                                 } else {
2740                                         vc->vc_x++;
2741                                         draw_to = (vc->vc_pos += 2);
2742                                 }
2743
2744                                 if (!--width) break;
2745
2746                                 tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
2747                                 if (tc < 0) tc = ' ';
2748                                 next_c = ' ';
2749                         }
2750                         notify_write(vc, c);
2751
2752                         if (inverse)
2753                                 con_flush(vc, draw_from, draw_to, &draw_x);
2754
2755                         if (rescan) {
2756                                 rescan = 0;
2757                                 inverse = 0;
2758                                 width = 1;
2759                                 c = orig;
2760                                 goto rescan_last_byte;
2761                         }
2762                         continue;
2763                 }
2764                 con_flush(vc, draw_from, draw_to, &draw_x);
2765                 do_con_trol(tty, vc, orig);
2766         }
2767         con_flush(vc, draw_from, draw_to, &draw_x);
2768         vc_uniscr_debug_check(vc);
2769         console_conditional_schedule();
2770         console_unlock();
2771         notify_update(vc);
2772         return n;
2773 }
2774
2775 /*
2776  * This is the console switching callback.
2777  *
2778  * Doing console switching in a process context allows
2779  * us to do the switches asynchronously (needed when we want
2780  * to switch due to a keyboard interrupt).  Synchronization
2781  * with other console code and prevention of re-entrancy is
2782  * ensured with console_lock.
2783  */
2784 static void console_callback(struct work_struct *ignored)
2785 {
2786         console_lock();
2787
2788         if (want_console >= 0) {
2789                 if (want_console != fg_console &&
2790                     vc_cons_allocated(want_console)) {
2791                         hide_cursor(vc_cons[fg_console].d);
2792                         change_console(vc_cons[want_console].d);
2793                         /* we only changed when the console had already
2794                            been allocated - a new console is not created
2795                            in an interrupt routine */
2796                 }
2797                 want_console = -1;
2798         }
2799         if (do_poke_blanked_console) { /* do not unblank for a LED change */
2800                 do_poke_blanked_console = 0;
2801                 poke_blanked_console();
2802         }
2803         if (scrollback_delta) {
2804                 struct vc_data *vc = vc_cons[fg_console].d;
2805                 clear_selection();
2806                 if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2807                         vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2808                 scrollback_delta = 0;
2809         }
2810         if (blank_timer_expired) {
2811                 do_blank_screen(0);
2812                 blank_timer_expired = 0;
2813         }
2814         notify_update(vc_cons[fg_console].d);
2815
2816         console_unlock();
2817 }
2818
2819 int set_console(int nr)
2820 {
2821         struct vc_data *vc = vc_cons[fg_console].d;
2822
2823         if (!vc_cons_allocated(nr) || vt_dont_switch ||
2824                 (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2825
2826                 /*
2827                  * Console switch will fail in console_callback() or
2828                  * change_console() so there is no point scheduling
2829                  * the callback
2830                  *
2831                  * Existing set_console() users don't check the return
2832                  * value so this shouldn't break anything
2833                  */
2834                 return -EINVAL;
2835         }
2836
2837         want_console = nr;
2838         schedule_console_callback();
2839
2840         return 0;
2841 }
2842
2843 struct tty_driver *console_driver;
2844
2845 #ifdef CONFIG_VT_CONSOLE
2846
2847 /**
2848  * vt_kmsg_redirect() - Sets/gets the kernel message console
2849  * @new:        The new virtual terminal number or -1 if the console should stay
2850  *              unchanged
2851  *
2852  * By default, the kernel messages are always printed on the current virtual
2853  * console. However, the user may modify that default with the
2854  * TIOCL_SETKMSGREDIRECT ioctl call.
2855  *
2856  * This function sets the kernel message console to be @new. It returns the old
2857  * virtual console number. The virtual terminal number 0 (both as parameter and
2858  * return value) means no redirection (i.e. always printed on the currently
2859  * active console).
2860  *
2861  * The parameter -1 means that only the current console is returned, but the
2862  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
2863  * case to make the code more understandable.
2864  *
2865  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
2866  * the parameter and always returns 0.
2867  */
2868 int vt_kmsg_redirect(int new)
2869 {
2870         static int kmsg_con;
2871
2872         if (new != -1)
2873                 return xchg(&kmsg_con, new);
2874         else
2875                 return kmsg_con;
2876 }
2877
2878 /*
2879  *      Console on virtual terminal
2880  *
2881  * The console must be locked when we get here.
2882  */
2883
2884 static void vt_console_print(struct console *co, const char *b, unsigned count)
2885 {
2886         struct vc_data *vc = vc_cons[fg_console].d;
2887         unsigned char c;
2888         static DEFINE_SPINLOCK(printing_lock);
2889         const ushort *start;
2890         ushort cnt = 0;
2891         ushort myx;
2892         int kmsg_console;
2893
2894         /* console busy or not yet initialized */
2895         if (!printable)
2896                 return;
2897         if (!spin_trylock(&printing_lock))
2898                 return;
2899
2900         kmsg_console = vt_get_kmsg_redirect();
2901         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
2902                 vc = vc_cons[kmsg_console - 1].d;
2903
2904         /* read `x' only after setting currcons properly (otherwise
2905            the `x' macro will read the x of the foreground console). */
2906         myx = vc->vc_x;
2907
2908         if (!vc_cons_allocated(fg_console)) {
2909                 /* impossible */
2910                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
2911                 goto quit;
2912         }
2913
2914         if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
2915                 goto quit;
2916
2917         /* undraw cursor first */
2918         if (con_is_fg(vc))
2919                 hide_cursor(vc);
2920
2921         start = (ushort *)vc->vc_pos;
2922
2923         /* Contrived structure to try to emulate original need_wrap behaviour
2924          * Problems caused when we have need_wrap set on '\n' character */
2925         while (count--) {
2926                 c = *b++;
2927                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
2928                         if (cnt > 0) {
2929                                 if (con_is_visible(vc))
2930                                         vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2931                                 vc->vc_x += cnt;
2932                                 if (vc->vc_need_wrap)
2933                                         vc->vc_x--;
2934                                 cnt = 0;
2935                         }
2936                         if (c == 8) {           /* backspace */
2937                                 bs(vc);
2938                                 start = (ushort *)vc->vc_pos;
2939                                 myx = vc->vc_x;
2940                                 continue;
2941                         }
2942                         if (c != 13)
2943                                 lf(vc);
2944                         cr(vc);
2945                         start = (ushort *)vc->vc_pos;
2946                         myx = vc->vc_x;
2947                         if (c == 10 || c == 13)
2948                                 continue;
2949                 }
2950                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
2951                 notify_write(vc, c);
2952                 cnt++;
2953                 if (myx == vc->vc_cols - 1) {
2954                         vc->vc_need_wrap = 1;
2955                         continue;
2956                 }
2957                 vc->vc_pos += 2;
2958                 myx++;
2959         }
2960         if (cnt > 0) {
2961                 if (con_is_visible(vc))
2962                         vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
2963                 vc->vc_x += cnt;
2964                 if (vc->vc_x == vc->vc_cols) {
2965                         vc->vc_x--;
2966                         vc->vc_need_wrap = 1;
2967                 }
2968         }
2969         set_cursor(vc);
2970         notify_update(vc);
2971
2972 quit:
2973         spin_unlock(&printing_lock);
2974 }
2975
2976 static struct tty_driver *vt_console_device(struct console *c, int *index)
2977 {
2978         *index = c->index ? c->index-1 : fg_console;
2979         return console_driver;
2980 }
2981
2982 static struct console vt_console_driver = {
2983         .name           = "tty",
2984         .write          = vt_console_print,
2985         .device         = vt_console_device,
2986         .unblank        = unblank_screen,
2987         .flags          = CON_PRINTBUFFER,
2988         .index          = -1,
2989 };
2990 #endif
2991
2992 /*
2993  *      Handling of Linux-specific VC ioctls
2994  */
2995
2996 /*
2997  * Generally a bit racy with respect to console_lock();.
2998  *
2999  * There are some functions which don't need it.
3000  *
3001  * There are some functions which can sleep for arbitrary periods
3002  * (paste_selection) but we don't need the lock there anyway.
3003  *
3004  * set_selection has locking, and definitely needs it
3005  */
3006
3007 int tioclinux(struct tty_struct *tty, unsigned long arg)
3008 {
3009         char type, data;
3010         char __user *p = (char __user *)arg;
3011         int lines;
3012         int ret;
3013
3014         if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3015                 return -EPERM;
3016         if (get_user(type, p))
3017                 return -EFAULT;
3018         ret = 0;
3019
3020         switch (type)
3021         {
3022                 case TIOCL_SETSEL:
3023                         console_lock();
3024                         ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
3025                         console_unlock();
3026                         break;
3027                 case TIOCL_PASTESEL:
3028                         ret = paste_selection(tty);
3029                         break;
3030                 case TIOCL_UNBLANKSCREEN:
3031                         console_lock();
3032                         unblank_screen();
3033                         console_unlock();
3034                         break;
3035                 case TIOCL_SELLOADLUT:
3036                         console_lock();
3037                         ret = sel_loadlut(p);
3038                         console_unlock();
3039                         break;
3040                 case TIOCL_GETSHIFTSTATE:
3041
3042         /*
3043          * Make it possible to react to Shift+Mousebutton.
3044          * Note that 'shift_state' is an undocumented
3045          * kernel-internal variable; programs not closely
3046          * related to the kernel should not use this.
3047          */
3048                         data = vt_get_shift_state();
3049                         ret = put_user(data, p);
3050                         break;
3051                 case TIOCL_GETMOUSEREPORTING:
3052                         console_lock(); /* May be overkill */
3053                         data = mouse_reporting();
3054                         console_unlock();
3055                         ret = put_user(data, p);
3056                         break;
3057                 case TIOCL_SETVESABLANK:
3058                         console_lock();
3059                         ret = set_vesa_blanking(p);
3060                         console_unlock();
3061                         break;
3062                 case TIOCL_GETKMSGREDIRECT:
3063                         data = vt_get_kmsg_redirect();
3064                         ret = put_user(data, p);
3065                         break;
3066                 case TIOCL_SETKMSGREDIRECT:
3067                         if (!capable(CAP_SYS_ADMIN)) {
3068                                 ret = -EPERM;
3069                         } else {
3070                                 if (get_user(data, p+1))
3071                                         ret = -EFAULT;
3072                                 else
3073                                         vt_kmsg_redirect(data);
3074                         }
3075                         break;
3076                 case TIOCL_GETFGCONSOLE:
3077                         /* No locking needed as this is a transiently
3078                            correct return anyway if the caller hasn't
3079                            disabled switching */
3080                         ret = fg_console;
3081                         break;
3082                 case TIOCL_SCROLLCONSOLE:
3083                         if (get_user(lines, (s32 __user *)(p+4))) {
3084                                 ret = -EFAULT;
3085                         } else {
3086                                 /* Need the console lock here. Note that lots
3087                                    of other calls need fixing before the lock
3088                                    is actually useful ! */
3089                                 console_lock();
3090                                 scrollfront(vc_cons[fg_console].d, lines);
3091                                 console_unlock();
3092                                 ret = 0;
3093                         }
3094                         break;
3095                 case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
3096                         console_lock();
3097                         ignore_poke = 1;
3098                         do_blank_screen(0);
3099                         console_unlock();
3100                         break;
3101                 case TIOCL_BLANKEDSCREEN:
3102                         ret = console_blanked;
3103                         break;
3104                 default:
3105                         ret = -EINVAL;
3106                         break;
3107         }
3108         return ret;
3109 }
3110
3111 /*
3112  * /dev/ttyN handling
3113  */
3114
3115 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3116 {
3117         int     retval;
3118
3119         retval = do_con_write(tty, buf, count);
3120         con_flush_chars(tty);
3121
3122         return retval;
3123 }
3124
3125 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3126 {
3127         if (in_interrupt())
3128                 return 0;       /* n_r3964 calls put_char() from interrupt context */
3129         return do_con_write(tty, &ch, 1);
3130 }
3131
3132 static int con_write_room(struct tty_struct *tty)
3133 {
3134         if (tty->stopped)
3135                 return 0;
3136         return 32768;           /* No limit, really; we're not buffering */
3137 }
3138
3139 static int con_chars_in_buffer(struct tty_struct *tty)
3140 {
3141         return 0;               /* we're not buffering */
3142 }
3143
3144 /*
3145  * con_throttle and con_unthrottle are only used for
3146  * paste_selection(), which has to stuff in a large number of
3147  * characters...
3148  */
3149 static void con_throttle(struct tty_struct *tty)
3150 {
3151 }
3152
3153 static void con_unthrottle(struct tty_struct *tty)
3154 {
3155         struct vc_data *vc = tty->driver_data;
3156
3157         wake_up_interruptible(&vc->paste_wait);
3158 }
3159
3160 /*
3161  * Turn the Scroll-Lock LED on when the tty is stopped
3162  */
3163 static void con_stop(struct tty_struct *tty)
3164 {
3165         int console_num;
3166         if (!tty)
3167                 return;
3168         console_num = tty->index;
3169         if (!vc_cons_allocated(console_num))
3170                 return;
3171         vt_kbd_con_stop(console_num);
3172 }
3173
3174 /*
3175  * Turn the Scroll-Lock LED off when the console is started
3176  */
3177 static void con_start(struct tty_struct *tty)
3178 {
3179         int console_num;
3180         if (!tty)
3181                 return;
3182         console_num = tty->index;
3183         if (!vc_cons_allocated(console_num))
3184                 return;
3185         vt_kbd_con_start(console_num);
3186 }
3187
3188 static void con_flush_chars(struct tty_struct *tty)
3189 {
3190         struct vc_data *vc;
3191
3192         if (in_interrupt())     /* from flush_to_ldisc */
3193                 return;
3194
3195         /* if we race with con_close(), vt may be null */
3196         console_lock();
3197         vc = tty->driver_data;
3198         if (vc)
3199                 set_cursor(vc);
3200         console_unlock();
3201 }
3202
3203 /*
3204  * Allocate the console screen memory.
3205  */
3206 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3207 {
3208         unsigned int currcons = tty->index;
3209         struct vc_data *vc;
3210         int ret;
3211
3212         console_lock();
3213         ret = vc_allocate(currcons);
3214         if (ret)
3215                 goto unlock;
3216
3217         vc = vc_cons[currcons].d;
3218
3219         /* Still being freed */
3220         if (vc->port.tty) {
3221                 ret = -ERESTARTSYS;
3222                 goto unlock;
3223         }
3224
3225         ret = tty_port_install(&vc->port, driver, tty);
3226         if (ret)
3227                 goto unlock;
3228
3229         tty->driver_data = vc;
3230         vc->port.tty = tty;
3231
3232         if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3233                 tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3234                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3235         }
3236         if (vc->vc_utf)
3237                 tty->termios.c_iflag |= IUTF8;
3238         else
3239                 tty->termios.c_iflag &= ~IUTF8;
3240 unlock:
3241         console_unlock();
3242         return ret;
3243 }
3244
3245 static int con_open(struct tty_struct *tty, struct file *filp)
3246 {
3247         /* everything done in install */
3248         return 0;
3249 }
3250
3251
3252 static void con_close(struct tty_struct *tty, struct file *filp)
3253 {
3254         /* Nothing to do - we defer to shutdown */
3255 }
3256
3257 static void con_shutdown(struct tty_struct *tty)
3258 {
3259         struct vc_data *vc = tty->driver_data;
3260         BUG_ON(vc == NULL);
3261         console_lock();
3262         vc->port.tty = NULL;
3263         console_unlock();
3264 }
3265
3266 static int default_color           = 7; /* white */
3267 static int default_italic_color    = 2; // green (ASCII)
3268 static int default_underline_color = 3; // cyan (ASCII)
3269 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3270 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3271 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3272
3273 static void vc_init(struct vc_data *vc, unsigned int rows,
3274                     unsigned int cols, int do_clear)
3275 {
3276         int j, k ;
3277
3278         vc->vc_cols = cols;
3279         vc->vc_rows = rows;
3280         vc->vc_size_row = cols << 1;
3281         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3282
3283         set_origin(vc);
3284         vc->vc_pos = vc->vc_origin;
3285         reset_vc(vc);
3286         for (j=k=0; j<16; j++) {
3287                 vc->vc_palette[k++] = default_red[j] ;
3288                 vc->vc_palette[k++] = default_grn[j] ;
3289                 vc->vc_palette[k++] = default_blu[j] ;
3290         }
3291         vc->vc_def_color       = default_color;
3292         vc->vc_ulcolor         = default_underline_color;
3293         vc->vc_itcolor         = default_italic_color;
3294         vc->vc_halfcolor       = 0x08;   /* grey */
3295         init_waitqueue_head(&vc->paste_wait);
3296         reset_terminal(vc, do_clear);
3297 }
3298
3299 /*
3300  * This routine initializes console interrupts, and does nothing
3301  * else. If you want the screen to clear, call tty_write with
3302  * the appropriate escape-sequence.
3303  */
3304
3305 static int __init con_init(void)
3306 {
3307         const char *display_desc = NULL;
3308         struct vc_data *vc;
3309         unsigned int currcons = 0, i;
3310
3311         console_lock();
3312
3313         if (conswitchp)
3314                 display_desc = conswitchp->con_startup();
3315         if (!display_desc) {
3316                 fg_console = 0;
3317                 console_unlock();
3318                 return 0;
3319         }
3320
3321         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3322                 struct con_driver *con_driver = &registered_con_driver[i];
3323
3324                 if (con_driver->con == NULL) {
3325                         con_driver->con = conswitchp;
3326                         con_driver->desc = display_desc;
3327                         con_driver->flag = CON_DRIVER_FLAG_INIT;
3328                         con_driver->first = 0;
3329                         con_driver->last = MAX_NR_CONSOLES - 1;
3330                         break;
3331                 }
3332         }
3333
3334         for (i = 0; i < MAX_NR_CONSOLES; i++)
3335                 con_driver_map[i] = conswitchp;
3336
3337         if (blankinterval) {
3338                 blank_state = blank_normal_wait;
3339                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3340         }
3341
3342         for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3343                 vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3344                 INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3345                 tty_port_init(&vc->port);
3346                 visual_init(vc, currcons, 1);
3347                 vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3348                 vc_init(vc, vc->vc_rows, vc->vc_cols,
3349                         currcons || !vc->vc_sw->con_save_screen);
3350         }
3351         currcons = fg_console = 0;
3352         master_display_fg = vc = vc_cons[currcons].d;
3353         set_origin(vc);
3354         save_screen(vc);
3355         gotoxy(vc, vc->vc_x, vc->vc_y);
3356         csi_J(vc, 0);
3357         update_screen(vc);
3358         pr_info("Console: %s %s %dx%d\n",
3359                 vc->vc_can_do_color ? "colour" : "mono",
3360                 display_desc, vc->vc_cols, vc->vc_rows);
3361         printable = 1;
3362
3363         console_unlock();
3364
3365 #ifdef CONFIG_VT_CONSOLE
3366         register_console(&vt_console_driver);
3367 #endif
3368         return 0;
3369 }
3370 console_initcall(con_init);
3371
3372 static const struct tty_operations con_ops = {
3373         .install = con_install,
3374         .open = con_open,
3375         .close = con_close,
3376         .write = con_write,
3377         .write_room = con_write_room,
3378         .put_char = con_put_char,
3379         .flush_chars = con_flush_chars,
3380         .chars_in_buffer = con_chars_in_buffer,
3381         .ioctl = vt_ioctl,
3382 #ifdef CONFIG_COMPAT
3383         .compat_ioctl = vt_compat_ioctl,
3384 #endif
3385         .stop = con_stop,
3386         .start = con_start,
3387         .throttle = con_throttle,
3388         .unthrottle = con_unthrottle,
3389         .resize = vt_resize,
3390         .shutdown = con_shutdown
3391 };
3392
3393 static struct cdev vc0_cdev;
3394
3395 static ssize_t show_tty_active(struct device *dev,
3396                                 struct device_attribute *attr, char *buf)
3397 {
3398         return sprintf(buf, "tty%d\n", fg_console + 1);
3399 }
3400 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3401
3402 static struct attribute *vt_dev_attrs[] = {
3403         &dev_attr_active.attr,
3404         NULL
3405 };
3406
3407 ATTRIBUTE_GROUPS(vt_dev);
3408
3409 int __init vty_init(const struct file_operations *console_fops)
3410 {
3411         cdev_init(&vc0_cdev, console_fops);
3412         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3413             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3414                 panic("Couldn't register /dev/tty0 driver\n");
3415         tty0dev = device_create_with_groups(tty_class, NULL,
3416                                             MKDEV(TTY_MAJOR, 0), NULL,
3417                                             vt_dev_groups, "tty0");
3418         if (IS_ERR(tty0dev))
3419                 tty0dev = NULL;
3420
3421         vcs_init();
3422
3423         console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
3424         if (!console_driver)
3425                 panic("Couldn't allocate console driver\n");
3426
3427         console_driver->name = "tty";
3428         console_driver->name_base = 1;
3429         console_driver->major = TTY_MAJOR;
3430         console_driver->minor_start = 1;
3431         console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3432         console_driver->init_termios = tty_std_termios;
3433         if (default_utf8)
3434                 console_driver->init_termios.c_iflag |= IUTF8;
3435         console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
3436         tty_set_operations(console_driver, &con_ops);
3437         if (tty_register_driver(console_driver))
3438                 panic("Couldn't register console driver\n");
3439         kbd_init();
3440         console_map_init();
3441 #ifdef CONFIG_MDA_CONSOLE
3442         mda_console_init();
3443 #endif
3444         return 0;
3445 }
3446
3447 #ifndef VT_SINGLE_DRIVER
3448
3449 static struct class *vtconsole_class;
3450
3451 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3452                            int deflt)
3453 {
3454         struct module *owner = csw->owner;
3455         const char *desc = NULL;
3456         struct con_driver *con_driver;
3457         int i, j = -1, k = -1, retval = -ENODEV;
3458
3459         if (!try_module_get(owner))
3460                 return -ENODEV;
3461
3462         WARN_CONSOLE_UNLOCKED();
3463
3464         /* check if driver is registered */
3465         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3466                 con_driver = &registered_con_driver[i];
3467
3468                 if (con_driver->con == csw) {
3469                         desc = con_driver->desc;
3470                         retval = 0;
3471                         break;
3472                 }
3473         }
3474
3475         if (retval)
3476                 goto err;
3477
3478         if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3479                 csw->con_startup();
3480                 con_driver->flag |= CON_DRIVER_FLAG_INIT;
3481         }
3482
3483         if (deflt) {
3484                 if (conswitchp)
3485                         module_put(conswitchp->owner);
3486
3487                 __module_get(owner);
3488                 conswitchp = csw;
3489         }
3490
3491         first = max(first, con_driver->first);
3492         last = min(last, con_driver->last);
3493
3494         for (i = first; i <= last; i++) {
3495                 int old_was_color;
3496                 struct vc_data *vc = vc_cons[i].d;
3497
3498                 if (con_driver_map[i])
3499                         module_put(con_driver_map[i]->owner);
3500                 __module_get(owner);
3501                 con_driver_map[i] = csw;
3502
3503                 if (!vc || !vc->vc_sw)
3504                         continue;
3505
3506                 j = i;
3507
3508                 if (con_is_visible(vc)) {
3509                         k = i;
3510                         save_screen(vc);
3511                 }
3512
3513                 old_was_color = vc->vc_can_do_color;
3514                 vc->vc_sw->con_deinit(vc);
3515                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3516                 visual_init(vc, i, 0);
3517                 set_origin(vc);
3518                 update_attr(vc);
3519
3520                 /* If the console changed between mono <-> color, then
3521                  * the attributes in the screenbuf will be wrong.  The
3522                  * following resets all attributes to something sane.
3523                  */
3524                 if (old_was_color != vc->vc_can_do_color)
3525                         clear_buffer_attributes(vc);
3526         }
3527
3528         pr_info("Console: switching ");
3529         if (!deflt)
3530                 pr_cont("consoles %d-%d ", first + 1, last + 1);
3531         if (j >= 0) {
3532                 struct vc_data *vc = vc_cons[j].d;
3533
3534                 pr_cont("to %s %s %dx%d\n",
3535                         vc->vc_can_do_color ? "colour" : "mono",
3536                         desc, vc->vc_cols, vc->vc_rows);
3537
3538                 if (k >= 0) {
3539                         vc = vc_cons[k].d;
3540                         update_screen(vc);
3541                 }
3542         } else {
3543                 pr_cont("to %s\n", desc);
3544         }
3545
3546         retval = 0;
3547 err:
3548         module_put(owner);
3549         return retval;
3550 };
3551
3552
3553 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3554 /* unlocked version of unbind_con_driver() */
3555 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3556 {
3557         struct module *owner = csw->owner;
3558         const struct consw *defcsw = NULL;
3559         struct con_driver *con_driver = NULL, *con_back = NULL;
3560         int i, retval = -ENODEV;
3561
3562         if (!try_module_get(owner))
3563                 return -ENODEV;
3564
3565         WARN_CONSOLE_UNLOCKED();
3566
3567         /* check if driver is registered and if it is unbindable */
3568         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3569                 con_driver = &registered_con_driver[i];
3570
3571                 if (con_driver->con == csw &&
3572                     con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3573                         retval = 0;
3574                         break;
3575                 }
3576         }
3577
3578         if (retval)
3579                 goto err;
3580
3581         retval = -ENODEV;
3582
3583         /* check if backup driver exists */
3584         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3585                 con_back = &registered_con_driver[i];
3586
3587                 if (con_back->con && con_back->con != csw) {
3588                         defcsw = con_back->con;
3589                         retval = 0;
3590                         break;
3591                 }
3592         }
3593
3594         if (retval)
3595                 goto err;
3596
3597         if (!con_is_bound(csw))
3598                 goto err;
3599
3600         first = max(first, con_driver->first);
3601         last = min(last, con_driver->last);
3602
3603         for (i = first; i <= last; i++) {
3604                 if (con_driver_map[i] == csw) {
3605                         module_put(csw->owner);
3606                         con_driver_map[i] = NULL;
3607                 }
3608         }
3609
3610         if (!con_is_bound(defcsw)) {
3611                 const struct consw *defconsw = conswitchp;
3612
3613                 defcsw->con_startup();
3614                 con_back->flag |= CON_DRIVER_FLAG_INIT;
3615                 /*
3616                  * vgacon may change the default driver to point
3617                  * to dummycon, we restore it here...
3618                  */
3619                 conswitchp = defconsw;
3620         }
3621
3622         if (!con_is_bound(csw))
3623                 con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3624
3625         /* ignore return value, binding should not fail */
3626         do_bind_con_driver(defcsw, first, last, deflt);
3627 err:
3628         module_put(owner);
3629         return retval;
3630
3631 }
3632 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3633
3634 static int vt_bind(struct con_driver *con)
3635 {
3636         const struct consw *defcsw = NULL, *csw = NULL;
3637         int i, more = 1, first = -1, last = -1, deflt = 0;
3638
3639         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3640                 goto err;
3641
3642         csw = con->con;
3643
3644         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3645                 struct con_driver *con = &registered_con_driver[i];
3646
3647                 if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3648                         defcsw = con->con;
3649                         break;
3650                 }
3651         }
3652
3653         if (!defcsw)
3654                 goto err;
3655
3656         while (more) {
3657                 more = 0;
3658
3659                 for (i = con->first; i <= con->last; i++) {
3660                         if (con_driver_map[i] == defcsw) {
3661                                 if (first == -1)
3662                                         first = i;
3663                                 last = i;
3664                                 more = 1;
3665                         } else if (first != -1)
3666                                 break;
3667                 }
3668
3669                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3670                         deflt = 1;
3671
3672                 if (first != -1)
3673                         do_bind_con_driver(csw, first, last, deflt);
3674
3675                 first = -1;
3676                 last = -1;
3677                 deflt = 0;
3678         }
3679
3680 err:
3681         return 0;
3682 }
3683
3684 static int vt_unbind(struct con_driver *con)
3685 {
3686         const struct consw *csw = NULL;
3687         int i, more = 1, first = -1, last = -1, deflt = 0;
3688         int ret;
3689
3690         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3691                 goto err;
3692
3693         csw = con->con;
3694
3695         while (more) {
3696                 more = 0;
3697
3698                 for (i = con->first; i <= con->last; i++) {
3699                         if (con_driver_map[i] == csw) {
3700                                 if (first == -1)
3701                                         first = i;
3702                                 last = i;
3703                                 more = 1;
3704                         } else if (first != -1)
3705                                 break;
3706                 }
3707
3708                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3709                         deflt = 1;
3710
3711                 if (first != -1) {
3712                         ret = do_unbind_con_driver(csw, first, last, deflt);
3713                         if (ret != 0)
3714                                 return ret;
3715                 }
3716
3717                 first = -1;
3718                 last = -1;
3719                 deflt = 0;
3720         }
3721
3722 err:
3723         return 0;
3724 }
3725 #else
3726 static inline int vt_bind(struct con_driver *con)
3727 {
3728         return 0;
3729 }
3730 static inline int vt_unbind(struct con_driver *con)
3731 {
3732         return 0;
3733 }
3734 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3735
3736 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3737                           const char *buf, size_t count)
3738 {
3739         struct con_driver *con = dev_get_drvdata(dev);
3740         int bind = simple_strtoul(buf, NULL, 0);
3741
3742         console_lock();
3743
3744         if (bind)
3745                 vt_bind(con);
3746         else
3747                 vt_unbind(con);
3748
3749         console_unlock();
3750
3751         return count;
3752 }
3753
3754 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3755                          char *buf)
3756 {
3757         struct con_driver *con = dev_get_drvdata(dev);
3758         int bind = con_is_bound(con->con);
3759
3760         return snprintf(buf, PAGE_SIZE, "%i\n", bind);
3761 }
3762
3763 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3764                          char *buf)
3765 {
3766         struct con_driver *con = dev_get_drvdata(dev);
3767
3768         return snprintf(buf, PAGE_SIZE, "%s %s\n",
3769                         (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3770                          con->desc);
3771
3772 }
3773
3774 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3775 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3776
3777 static struct attribute *con_dev_attrs[] = {
3778         &dev_attr_bind.attr,
3779         &dev_attr_name.attr,
3780         NULL
3781 };
3782
3783 ATTRIBUTE_GROUPS(con_dev);
3784
3785 static int vtconsole_init_device(struct con_driver *con)
3786 {
3787         con->flag |= CON_DRIVER_FLAG_ATTR;
3788         return 0;
3789 }
3790
3791 static void vtconsole_deinit_device(struct con_driver *con)
3792 {
3793         con->flag &= ~CON_DRIVER_FLAG_ATTR;
3794 }
3795
3796 /**
3797  * con_is_bound - checks if driver is bound to the console
3798  * @csw: console driver
3799  *
3800  * RETURNS: zero if unbound, nonzero if bound
3801  *
3802  * Drivers can call this and if zero, they should release
3803  * all resources allocated on con_startup()
3804  */
3805 int con_is_bound(const struct consw *csw)
3806 {
3807         int i, bound = 0;
3808
3809         for (i = 0; i < MAX_NR_CONSOLES; i++) {
3810                 if (con_driver_map[i] == csw) {
3811                         bound = 1;
3812                         break;
3813                 }
3814         }
3815
3816         return bound;
3817 }
3818 EXPORT_SYMBOL(con_is_bound);
3819
3820 /**
3821  * con_debug_enter - prepare the console for the kernel debugger
3822  * @sw: console driver
3823  *
3824  * Called when the console is taken over by the kernel debugger, this
3825  * function needs to save the current console state, then put the console
3826  * into a state suitable for the kernel debugger.
3827  *
3828  * RETURNS:
3829  * Zero on success, nonzero if a failure occurred when trying to prepare
3830  * the console for the debugger.
3831  */
3832 int con_debug_enter(struct vc_data *vc)
3833 {
3834         int ret = 0;
3835
3836         saved_fg_console = fg_console;
3837         saved_last_console = last_console;
3838         saved_want_console = want_console;
3839         saved_vc_mode = vc->vc_mode;
3840         saved_console_blanked = console_blanked;
3841         vc->vc_mode = KD_TEXT;
3842         console_blanked = 0;
3843         if (vc->vc_sw->con_debug_enter)
3844                 ret = vc->vc_sw->con_debug_enter(vc);
3845 #ifdef CONFIG_KGDB_KDB
3846         /* Set the initial LINES variable if it is not already set */
3847         if (vc->vc_rows < 999) {
3848                 int linecount;
3849                 char lns[4];
3850                 const char *setargs[3] = {
3851                         "set",
3852                         "LINES",
3853                         lns,
3854                 };
3855                 if (kdbgetintenv(setargs[0], &linecount)) {
3856                         snprintf(lns, 4, "%i", vc->vc_rows);
3857                         kdb_set(2, setargs);
3858                 }
3859         }
3860         if (vc->vc_cols < 999) {
3861                 int colcount;
3862                 char cols[4];
3863                 const char *setargs[3] = {
3864                         "set",
3865                         "COLUMNS",
3866                         cols,
3867                 };
3868                 if (kdbgetintenv(setargs[0], &colcount)) {
3869                         snprintf(cols, 4, "%i", vc->vc_cols);
3870                         kdb_set(2, setargs);
3871                 }
3872         }
3873 #endif /* CONFIG_KGDB_KDB */
3874         return ret;
3875 }
3876 EXPORT_SYMBOL_GPL(con_debug_enter);
3877
3878 /**
3879  * con_debug_leave - restore console state
3880  * @sw: console driver
3881  *
3882  * Restore the console state to what it was before the kernel debugger
3883  * was invoked.
3884  *
3885  * RETURNS:
3886  * Zero on success, nonzero if a failure occurred when trying to restore
3887  * the console.
3888  */
3889 int con_debug_leave(void)
3890 {
3891         struct vc_data *vc;
3892         int ret = 0;
3893
3894         fg_console = saved_fg_console;
3895         last_console = saved_last_console;
3896         want_console = saved_want_console;
3897         console_blanked = saved_console_blanked;
3898         vc_cons[fg_console].d->vc_mode = saved_vc_mode;
3899
3900         vc = vc_cons[fg_console].d;
3901         if (vc->vc_sw->con_debug_leave)
3902                 ret = vc->vc_sw->con_debug_leave(vc);
3903         return ret;
3904 }
3905 EXPORT_SYMBOL_GPL(con_debug_leave);
3906
3907 static int do_register_con_driver(const struct consw *csw, int first, int last)
3908 {
3909         struct module *owner = csw->owner;
3910         struct con_driver *con_driver;
3911         const char *desc;
3912         int i, retval;
3913
3914         WARN_CONSOLE_UNLOCKED();
3915
3916         if (!try_module_get(owner))
3917                 return -ENODEV;
3918
3919         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3920                 con_driver = &registered_con_driver[i];
3921
3922                 /* already registered */
3923                 if (con_driver->con == csw) {
3924                         retval = -EBUSY;
3925                         goto err;
3926                 }
3927         }
3928
3929         desc = csw->con_startup();
3930         if (!desc) {
3931                 retval = -ENODEV;
3932                 goto err;
3933         }
3934
3935         retval = -EINVAL;
3936
3937         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3938                 con_driver = &registered_con_driver[i];
3939
3940                 if (con_driver->con == NULL &&
3941                     !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
3942                         con_driver->con = csw;
3943                         con_driver->desc = desc;
3944                         con_driver->node = i;
3945                         con_driver->flag = CON_DRIVER_FLAG_MODULE |
3946                                            CON_DRIVER_FLAG_INIT;
3947                         con_driver->first = first;
3948                         con_driver->last = last;
3949                         retval = 0;
3950                         break;
3951                 }
3952         }
3953
3954         if (retval)
3955                 goto err;
3956
3957         con_driver->dev =
3958                 device_create_with_groups(vtconsole_class, NULL,
3959                                           MKDEV(0, con_driver->node),
3960                                           con_driver, con_dev_groups,
3961                                           "vtcon%i", con_driver->node);
3962         if (IS_ERR(con_driver->dev)) {
3963                 pr_warn("Unable to create device for %s; errno = %ld\n",
3964                         con_driver->desc, PTR_ERR(con_driver->dev));
3965                 con_driver->dev = NULL;
3966         } else {
3967                 vtconsole_init_device(con_driver);
3968         }
3969
3970 err:
3971         module_put(owner);
3972         return retval;
3973 }
3974
3975
3976 /**
3977  * do_unregister_con_driver - unregister console driver from console layer
3978  * @csw: console driver
3979  *
3980  * DESCRIPTION: All drivers that registers to the console layer must
3981  * call this function upon exit, or if the console driver is in a state
3982  * where it won't be able to handle console services, such as the
3983  * framebuffer console without loaded framebuffer drivers.
3984  *
3985  * The driver must unbind first prior to unregistration.
3986  */
3987 int do_unregister_con_driver(const struct consw *csw)
3988 {
3989         int i;
3990
3991         /* cannot unregister a bound driver */
3992         if (con_is_bound(csw))
3993                 return -EBUSY;
3994
3995         if (csw == conswitchp)
3996                 return -EINVAL;
3997
3998         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3999                 struct con_driver *con_driver = &registered_con_driver[i];
4000
4001                 if (con_driver->con == csw) {
4002                         /*
4003                          * Defer the removal of the sysfs entries since that
4004                          * will acquire the kernfs s_active lock and we can't
4005                          * acquire this lock while holding the console lock:
4006                          * the unbind sysfs entry imposes already the opposite
4007                          * order. Reset con already here to prevent any later
4008                          * lookup to succeed and mark this slot as zombie, so
4009                          * it won't get reused until we complete the removal
4010                          * in the deferred work.
4011                          */
4012                         con_driver->con = NULL;
4013                         con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4014                         schedule_work(&con_driver_unregister_work);
4015
4016                         return 0;
4017                 }
4018         }
4019
4020         return -ENODEV;
4021 }
4022 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4023
4024 static void con_driver_unregister_callback(struct work_struct *ignored)
4025 {
4026         int i;
4027
4028         console_lock();
4029
4030         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4031                 struct con_driver *con_driver = &registered_con_driver[i];
4032
4033                 if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4034                         continue;
4035
4036                 console_unlock();
4037
4038                 vtconsole_deinit_device(con_driver);
4039                 device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4040
4041                 console_lock();
4042
4043                 if (WARN_ON_ONCE(con_driver->con))
4044                         con_driver->con = NULL;
4045                 con_driver->desc = NULL;
4046                 con_driver->dev = NULL;
4047                 con_driver->node = 0;
4048                 WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4049                 con_driver->flag = 0;
4050                 con_driver->first = 0;
4051                 con_driver->last = 0;
4052         }
4053
4054         console_unlock();
4055 }
4056
4057 /*
4058  *      If we support more console drivers, this function is used
4059  *      when a driver wants to take over some existing consoles
4060  *      and become default driver for newly opened ones.
4061  *
4062  *      do_take_over_console is basically a register followed by unbind
4063  */
4064 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4065 {
4066         int err;
4067
4068         err = do_register_con_driver(csw, first, last);
4069         /*
4070          * If we get an busy error we still want to bind the console driver
4071          * and return success, as we may have unbound the console driver
4072          * but not unregistered it.
4073          */
4074         if (err == -EBUSY)
4075                 err = 0;
4076         if (!err)
4077                 do_bind_con_driver(csw, first, last, deflt);
4078
4079         return err;
4080 }
4081 EXPORT_SYMBOL_GPL(do_take_over_console);
4082
4083
4084 /*
4085  * give_up_console is a wrapper to unregister_con_driver. It will only
4086  * work if driver is fully unbound.
4087  */
4088 void give_up_console(const struct consw *csw)
4089 {
4090         console_lock();
4091         do_unregister_con_driver(csw);
4092         console_unlock();
4093 }
4094
4095 static int __init vtconsole_class_init(void)
4096 {
4097         int i;
4098
4099         vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4100         if (IS_ERR(vtconsole_class)) {
4101                 pr_warn("Unable to create vt console class; errno = %ld\n",
4102                         PTR_ERR(vtconsole_class));
4103                 vtconsole_class = NULL;
4104         }
4105
4106         /* Add system drivers to sysfs */
4107         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4108                 struct con_driver *con = &registered_con_driver[i];
4109
4110                 if (con->con && !con->dev) {
4111                         con->dev =
4112                                 device_create_with_groups(vtconsole_class, NULL,
4113                                                           MKDEV(0, con->node),
4114                                                           con, con_dev_groups,
4115                                                           "vtcon%i", con->node);
4116
4117                         if (IS_ERR(con->dev)) {
4118                                 pr_warn("Unable to create device for %s; errno = %ld\n",
4119                                         con->desc, PTR_ERR(con->dev));
4120                                 con->dev = NULL;
4121                         } else {
4122                                 vtconsole_init_device(con);
4123                         }
4124                 }
4125         }
4126
4127         return 0;
4128 }
4129 postcore_initcall(vtconsole_class_init);
4130
4131 #endif
4132
4133 /*
4134  *      Screen blanking
4135  */
4136
4137 static int set_vesa_blanking(char __user *p)
4138 {
4139         unsigned int mode;
4140
4141         if (get_user(mode, p + 1))
4142                 return -EFAULT;
4143
4144         vesa_blank_mode = (mode < 4) ? mode : 0;
4145         return 0;
4146 }
4147
4148 void do_blank_screen(int entering_gfx)
4149 {
4150         struct vc_data *vc = vc_cons[fg_console].d;
4151         int i;
4152
4153         WARN_CONSOLE_UNLOCKED();
4154
4155         if (console_blanked) {
4156                 if (blank_state == blank_vesa_wait) {
4157                         blank_state = blank_off;
4158                         vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4159                 }
4160                 return;
4161         }
4162
4163         /* entering graphics mode? */
4164         if (entering_gfx) {
4165                 hide_cursor(vc);
4166                 save_screen(vc);
4167                 vc->vc_sw->con_blank(vc, -1, 1);
4168                 console_blanked = fg_console + 1;
4169                 blank_state = blank_off;
4170                 set_origin(vc);
4171                 return;
4172         }
4173
4174         if (blank_state != blank_normal_wait)
4175                 return;
4176         blank_state = blank_off;
4177
4178         /* don't blank graphics */
4179         if (vc->vc_mode != KD_TEXT) {
4180                 console_blanked = fg_console + 1;
4181                 return;
4182         }
4183
4184         hide_cursor(vc);
4185         del_timer_sync(&console_timer);
4186         blank_timer_expired = 0;
4187
4188         save_screen(vc);
4189         /* In case we need to reset origin, blanking hook returns 1 */
4190         i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4191         console_blanked = fg_console + 1;
4192         if (i)
4193                 set_origin(vc);
4194
4195         if (console_blank_hook && console_blank_hook(1))
4196                 return;
4197
4198         if (vesa_off_interval && vesa_blank_mode) {
4199                 blank_state = blank_vesa_wait;
4200                 mod_timer(&console_timer, jiffies + vesa_off_interval);
4201         }
4202         vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4203 }
4204 EXPORT_SYMBOL(do_blank_screen);
4205
4206 /*
4207  * Called by timer as well as from vt_console_driver
4208  */
4209 void do_unblank_screen(int leaving_gfx)
4210 {
4211         struct vc_data *vc;
4212
4213         /* This should now always be called from a "sane" (read: can schedule)
4214          * context for the sake of the low level drivers, except in the special
4215          * case of oops_in_progress
4216          */
4217         if (!oops_in_progress)
4218                 might_sleep();
4219
4220         WARN_CONSOLE_UNLOCKED();
4221
4222         ignore_poke = 0;
4223         if (!console_blanked)
4224                 return;
4225         if (!vc_cons_allocated(fg_console)) {
4226                 /* impossible */
4227                 pr_warn("unblank_screen: tty %d not allocated ??\n",
4228                         fg_console + 1);
4229                 return;
4230         }
4231         vc = vc_cons[fg_console].d;
4232         /* Try to unblank in oops case too */
4233         if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
4234                 return; /* but leave console_blanked != 0 */
4235
4236         if (blankinterval) {
4237                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4238                 blank_state = blank_normal_wait;
4239         }
4240
4241         console_blanked = 0;
4242         if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
4243                 /* Low-level driver cannot restore -> do it ourselves */
4244                 update_screen(vc);
4245         if (console_blank_hook)
4246                 console_blank_hook(0);
4247         set_palette(vc);
4248         set_cursor(vc);
4249         vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4250 }
4251 EXPORT_SYMBOL(do_unblank_screen);
4252
4253 /*
4254  * This is called by the outside world to cause a forced unblank, mostly for
4255  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4256  * call it with 1 as an argument and so force a mode restore... that may kill
4257  * X or at least garbage the screen but would also make the Oops visible...
4258  */
4259 void unblank_screen(void)
4260 {
4261         do_unblank_screen(0);
4262 }
4263
4264 /*
4265  * We defer the timer blanking to work queue so it can take the console mutex
4266  * (console operations can still happen at irq time, but only from printk which
4267  * has the console mutex. Not perfect yet, but better than no locking
4268  */
4269 static void blank_screen_t(struct timer_list *unused)
4270 {
4271         blank_timer_expired = 1;
4272         schedule_work(&console_work);
4273 }
4274
4275 void poke_blanked_console(void)
4276 {
4277         WARN_CONSOLE_UNLOCKED();
4278
4279         /* Add this so we quickly catch whoever might call us in a non
4280          * safe context. Nowadays, unblank_screen() isn't to be called in
4281          * atomic contexts and is allowed to schedule (with the special case
4282          * of oops_in_progress, but that isn't of any concern for this
4283          * function. --BenH.
4284          */
4285         might_sleep();
4286
4287         /* This isn't perfectly race free, but a race here would be mostly harmless,
4288          * at worse, we'll do a spurrious blank and it's unlikely
4289          */
4290         del_timer(&console_timer);
4291         blank_timer_expired = 0;
4292
4293         if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4294                 return;
4295         if (console_blanked)
4296                 unblank_screen();
4297         else if (blankinterval) {
4298                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4299                 blank_state = blank_normal_wait;
4300         }
4301 }
4302
4303 /*
4304  *      Palettes
4305  */
4306
4307 static void set_palette(struct vc_data *vc)
4308 {
4309         WARN_CONSOLE_UNLOCKED();
4310
4311         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4312                 vc->vc_sw->con_set_palette(vc, color_table);
4313 }
4314
4315 /*
4316  * Load palette into the DAC registers. arg points to a colour
4317  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4318  */
4319
4320 int con_set_cmap(unsigned char __user *arg)
4321 {
4322         int i, j, k;
4323         unsigned char colormap[3*16];
4324
4325         if (copy_from_user(colormap, arg, sizeof(colormap)))
4326                 return -EFAULT;
4327
4328         console_lock();
4329         for (i = k = 0; i < 16; i++) {
4330                 default_red[i] = colormap[k++];
4331                 default_grn[i] = colormap[k++];
4332                 default_blu[i] = colormap[k++];
4333         }
4334         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4335                 if (!vc_cons_allocated(i))
4336                         continue;
4337                 for (j = k = 0; j < 16; j++) {
4338                         vc_cons[i].d->vc_palette[k++] = default_red[j];
4339                         vc_cons[i].d->vc_palette[k++] = default_grn[j];
4340                         vc_cons[i].d->vc_palette[k++] = default_blu[j];
4341                 }
4342                 set_palette(vc_cons[i].d);
4343         }
4344         console_unlock();
4345
4346         return 0;
4347 }
4348
4349 int con_get_cmap(unsigned char __user *arg)
4350 {
4351         int i, k;
4352         unsigned char colormap[3*16];
4353
4354         console_lock();
4355         for (i = k = 0; i < 16; i++) {
4356                 colormap[k++] = default_red[i];
4357                 colormap[k++] = default_grn[i];
4358                 colormap[k++] = default_blu[i];
4359         }
4360         console_unlock();
4361
4362         if (copy_to_user(arg, colormap, sizeof(colormap)))
4363                 return -EFAULT;
4364
4365         return 0;
4366 }
4367
4368 void reset_palette(struct vc_data *vc)
4369 {
4370         int j, k;
4371         for (j=k=0; j<16; j++) {
4372                 vc->vc_palette[k++] = default_red[j];
4373                 vc->vc_palette[k++] = default_grn[j];
4374                 vc->vc_palette[k++] = default_blu[j];
4375         }
4376         set_palette(vc);
4377 }
4378
4379 /*
4380  *  Font switching
4381  *
4382  *  Currently we only support fonts up to 32 pixels wide, at a maximum height
4383  *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints,
4384  *  depending on width) reserved for each character which is kinda wasty, but
4385  *  this is done in order to maintain compatibility with the EGA/VGA fonts. It
4386  *  is up to the actual low-level console-driver convert data into its favorite
4387  *  format (maybe we should add a `fontoffset' field to the `display'
4388  *  structure so we won't have to convert the fontdata all the time.
4389  *  /Jes
4390  */
4391
4392 #define max_font_size 65536
4393
4394 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4395 {
4396         struct console_font font;
4397         int rc = -EINVAL;
4398         int c;
4399
4400         if (op->data) {
4401                 font.data = kmalloc(max_font_size, GFP_KERNEL);
4402                 if (!font.data)
4403                         return -ENOMEM;
4404         } else
4405                 font.data = NULL;
4406
4407         console_lock();
4408         if (vc->vc_mode != KD_TEXT)
4409                 rc = -EINVAL;
4410         else if (vc->vc_sw->con_font_get)
4411                 rc = vc->vc_sw->con_font_get(vc, &font);
4412         else
4413                 rc = -ENOSYS;
4414         console_unlock();
4415
4416         if (rc)
4417                 goto out;
4418
4419         c = (font.width+7)/8 * 32 * font.charcount;
4420
4421         if (op->data && font.charcount > op->charcount)
4422                 rc = -ENOSPC;
4423         if (!(op->flags & KD_FONT_FLAG_OLD)) {
4424                 if (font.width > op->width || font.height > op->height)
4425                         rc = -ENOSPC;
4426         } else {
4427                 if (font.width != 8)
4428                         rc = -EIO;
4429                 else if ((op->height && font.height > op->height) ||
4430                          font.height > 32)
4431                         rc = -ENOSPC;
4432         }
4433         if (rc)
4434                 goto out;
4435
4436         op->height = font.height;
4437         op->width = font.width;
4438         op->charcount = font.charcount;
4439
4440         if (op->data && copy_to_user(op->data, font.data, c))
4441                 rc = -EFAULT;
4442
4443 out:
4444         kfree(font.data);
4445         return rc;
4446 }
4447
4448 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4449 {
4450         struct console_font font;
4451         int rc = -EINVAL;
4452         int size;
4453
4454         if (vc->vc_mode != KD_TEXT)
4455                 return -EINVAL;
4456         if (!op->data)
4457                 return -EINVAL;
4458         if (op->charcount > 512)
4459                 return -EINVAL;
4460         if (op->width <= 0 || op->width > 32 || op->height > 32)
4461                 return -EINVAL;
4462         size = (op->width+7)/8 * 32 * op->charcount;
4463         if (size > max_font_size)
4464                 return -ENOSPC;
4465
4466         font.data = memdup_user(op->data, size);
4467         if (IS_ERR(font.data))
4468                 return PTR_ERR(font.data);
4469
4470         if (!op->height) {              /* Need to guess font height [compat] */
4471                 int h, i;
4472                 u8 *charmap = font.data;
4473
4474                 /*
4475                  * If from KDFONTOP ioctl, don't allow things which can be done
4476                  * in userland,so that we can get rid of this soon
4477                  */
4478                 if (!(op->flags & KD_FONT_FLAG_OLD)) {
4479                         kfree(font.data);
4480                         return -EINVAL;
4481                 }
4482
4483                 for (h = 32; h > 0; h--)
4484                         for (i = 0; i < op->charcount; i++)
4485                                 if (charmap[32*i+h-1])
4486                                         goto nonzero;
4487
4488                 kfree(font.data);
4489                 return -EINVAL;
4490
4491         nonzero:
4492                 op->height = h;
4493         }
4494
4495         font.charcount = op->charcount;
4496         font.width = op->width;
4497         font.height = op->height;
4498
4499         console_lock();
4500         if (vc->vc_mode != KD_TEXT)
4501                 rc = -EINVAL;
4502         else if (vc->vc_sw->con_font_set)
4503                 rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
4504         else
4505                 rc = -ENOSYS;
4506         console_unlock();
4507         kfree(font.data);
4508         return rc;
4509 }
4510
4511 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4512 {
4513         struct console_font font = {.width = op->width, .height = op->height};
4514         char name[MAX_FONT_NAME];
4515         char *s = name;
4516         int rc;
4517
4518
4519         if (!op->data)
4520                 s = NULL;
4521         else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4522                 return -EFAULT;
4523         else
4524                 name[MAX_FONT_NAME - 1] = 0;
4525
4526         console_lock();
4527         if (vc->vc_mode != KD_TEXT) {
4528                 console_unlock();
4529                 return -EINVAL;
4530         }
4531         if (vc->vc_sw->con_font_default)
4532                 rc = vc->vc_sw->con_font_default(vc, &font, s);
4533         else
4534                 rc = -ENOSYS;
4535         console_unlock();
4536         if (!rc) {
4537                 op->width = font.width;
4538                 op->height = font.height;
4539         }
4540         return rc;
4541 }
4542
4543 static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
4544 {
4545         int con = op->height;
4546         int rc;
4547
4548
4549         console_lock();
4550         if (vc->vc_mode != KD_TEXT)
4551                 rc = -EINVAL;
4552         else if (!vc->vc_sw->con_font_copy)
4553                 rc = -ENOSYS;
4554         else if (con < 0 || !vc_cons_allocated(con))
4555                 rc = -ENOTTY;
4556         else if (con == vc->vc_num)     /* nothing to do */
4557                 rc = 0;
4558         else
4559                 rc = vc->vc_sw->con_font_copy(vc, con);
4560         console_unlock();
4561         return rc;
4562 }
4563
4564 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4565 {
4566         switch (op->op) {
4567         case KD_FONT_OP_SET:
4568                 return con_font_set(vc, op);
4569         case KD_FONT_OP_GET:
4570                 return con_font_get(vc, op);
4571         case KD_FONT_OP_SET_DEFAULT:
4572                 return con_font_default(vc, op);
4573         case KD_FONT_OP_COPY:
4574                 return con_font_copy(vc, op);
4575         }
4576         return -ENOSYS;
4577 }
4578
4579 /*
4580  *      Interface exported to selection and vcs.
4581  */
4582
4583 /* used by selection */
4584 u16 screen_glyph(struct vc_data *vc, int offset)
4585 {
4586         u16 w = scr_readw(screenpos(vc, offset, 1));
4587         u16 c = w & 0xff;
4588
4589         if (w & vc->vc_hi_font_mask)
4590                 c |= 0x100;
4591         return c;
4592 }
4593 EXPORT_SYMBOL_GPL(screen_glyph);
4594
4595 u32 screen_glyph_unicode(struct vc_data *vc, int n)
4596 {
4597         struct uni_screen *uniscr = get_vc_uniscr(vc);
4598
4599         if (uniscr)
4600                 return uniscr->lines[n / vc->vc_cols][n % vc->vc_cols];
4601         return inverse_translate(vc, screen_glyph(vc, n * 2), 1);
4602 }
4603 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4604
4605 /* used by vcs - note the word offset */
4606 unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
4607 {
4608         return screenpos(vc, 2 * w_offset, viewed);
4609 }
4610 EXPORT_SYMBOL_GPL(screen_pos);
4611
4612 void getconsxy(struct vc_data *vc, unsigned char *p)
4613 {
4614         p[0] = vc->vc_x;
4615         p[1] = vc->vc_y;
4616 }
4617
4618 void putconsxy(struct vc_data *vc, unsigned char *p)
4619 {
4620         hide_cursor(vc);
4621         gotoxy(vc, p[0], p[1]);
4622         set_cursor(vc);
4623 }
4624
4625 u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
4626 {
4627         if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4628                 return softcursor_original;
4629         return scr_readw(org);
4630 }
4631
4632 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4633 {
4634         scr_writew(val, org);
4635         if ((unsigned long)org == vc->vc_pos) {
4636                 softcursor_original = -1;
4637                 add_softcursor(vc);
4638         }
4639 }
4640
4641 void vcs_scr_updated(struct vc_data *vc)
4642 {
4643         notify_update(vc);
4644 }
4645
4646 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4647                 unsigned int rolled_over, void *base, unsigned int size)
4648 {
4649         unsigned long ubase = (unsigned long)base;
4650         ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4651         ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4652         ptrdiff_t origin = (void *)c->vc_origin - base;
4653         int margin = c->vc_size_row * 4;
4654         int from, wrap, from_off, avail;
4655
4656         /* Turn scrollback off */
4657         if (!lines) {
4658                 c->vc_visible_origin = c->vc_origin;
4659                 return;
4660         }
4661
4662         /* Do we have already enough to allow jumping from 0 to the end? */
4663         if (rolled_over > scr_end + margin) {
4664                 from = scr_end;
4665                 wrap = rolled_over + c->vc_size_row;
4666         } else {
4667                 from = 0;
4668                 wrap = size;
4669         }
4670
4671         from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4672         avail = (origin - from + wrap) % wrap;
4673
4674         /* Only a little piece would be left? Show all incl. the piece! */
4675         if (avail < 2 * margin)
4676                 margin = 0;
4677         if (from_off < margin)
4678                 from_off = 0;
4679         if (from_off > avail - margin)
4680                 from_off = avail;
4681
4682         c->vc_visible_origin = ubase + (from + from_off) % wrap;
4683 }
4684 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4685
4686 /*
4687  *      Visible symbols for modules
4688  */
4689
4690 EXPORT_SYMBOL(color_table);
4691 EXPORT_SYMBOL(default_red);
4692 EXPORT_SYMBOL(default_grn);
4693 EXPORT_SYMBOL(default_blu);
4694 EXPORT_SYMBOL(update_region);
4695 EXPORT_SYMBOL(redraw_screen);
4696 EXPORT_SYMBOL(vc_resize);
4697 EXPORT_SYMBOL(fg_console);
4698 EXPORT_SYMBOL(console_blank_hook);
4699 EXPORT_SYMBOL(console_blanked);
4700 EXPORT_SYMBOL(vc_cons);
4701 EXPORT_SYMBOL(global_cursor_default);
4702 #ifndef VT_SINGLE_DRIVER
4703 EXPORT_SYMBOL(give_up_console);
4704 #endif