drivers/tty/vt/vt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright (C) 1991, 1992  Linus Torvalds
   4  */
   5
   6 /*
   7  * Hopefully this will be a rather complete VT102 implementation.
   8  *
   9  * Beeping thanks to John T Kohl.
  10  *
  11  * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
  12  *   Chars, and VT100 enhancements by Peter MacDonald.
  13  *
  14  * Copy and paste function by Andrew Haylett,
  15  *   some enhancements by Alessandro Rubini.
  16  *
  17  * Code to check for different video-cards mostly by Galen Hunt,
  18  * <g-hunt@ee.utah.edu>
  19  *
  20  * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
  21  * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
  22  *
  23  * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
  24  * Resizing of consoles, aeb, 940926
  25  *
  26  * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
  27  * <poe@daimi.aau.dk>
  28  *
  29  * User-defined bell sound, new setterm control sequences and printk
  30  * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
  31  *
  32  * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
  33  *
  34  * Merge with the abstract console driver by Geert Uytterhoeven
  35  * <geert@linux-m68k.org>, Jan 1997.
  36  *
  37  *   Original m68k console driver modifications by
  38  *
  39  *     - Arno Griffioen <arno@usn.nl>
  40  *     - David Carter <carter@cs.bris.ac.uk>
  41  *
  42  *   The abstract console driver provides a generic interface for a text
  43  *   console. It supports VGA text mode, frame buffer based graphical consoles
  44  *   and special graphics processors that are only accessible through some
  45  *   registers (e.g. a TMS340x0 GSP).
  46  *
  47  *   The interface to the hardware is specified using a special structure
  48  *   (struct consw) which contains function pointers to console operations
  49  *   (see <linux/console.h> for more information).
  50  *
  51  * Support for changeable cursor shape
  52  * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
  53  *
  54  * Ported to i386 and con_scrolldelta fixed
  55  * by Emmanuel Marty <core@ggi-project.org>, April 1998
  56  *
  57  * Resurrected character buffers in videoram plus lots of other trickery
  58  * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
  59  *
  60  * Removed old-style timers, introduced console_timer, made timer
  61  * deletion SMP-safe.  17Jun00, Andrew Morton
  62  *
  63  * Removed console_lock, enabled interrupts across all console operations
  64  * 13 March 2001, Andrew Morton
  65  *
  66  * Fixed UTF-8 mode so alternate charset modes always work according
  67  * to control sequences interpreted in do_con_trol function
  68  * preserving backward VT100 semigraphics compatibility,
  69  * malformed UTF sequences represented as sequences of replacement glyphs,
  70  * original codes or '?' as a last resort if replacement glyph is undefined
  71  * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
  72  */
  73
  74 #include <linux/module.h>
  75 #include <linux/types.h>
  76 #include <linux/sched/signal.h>
  77 #include <linux/tty.h>
  78 #include <linux/tty_flip.h>
  79 #include <linux/kernel.h>
  80 #include <linux/string.h>
  81 #include <linux/errno.h>
  82 #include <linux/kd.h>
  83 #include <linux/slab.h>
  84 #include <linux/vmalloc.h>
  85 #include <linux/major.h>
  86 #include <linux/mm.h>
  87 #include <linux/console.h>
  88 #include <linux/init.h>
  89 #include <linux/mutex.h>
  90 #include <linux/vt_kern.h>
  91 #include <linux/selection.h>
  92 #include <linux/tiocl.h>
  93 #include <linux/kbd_kern.h>
  94 #include <linux/consolemap.h>
  95 #include <linux/timer.h>
  96 #include <linux/interrupt.h>
  97 #include <linux/workqueue.h>
  98 #include <linux/pm.h>
  99 #include <linux/font.h>
 100 #include <linux/bitops.h>
 101 #include <linux/notifier.h>
 102 #include <linux/device.h>
 103 #include <linux/io.h>
 104 #include <linux/uaccess.h>
 105 #include <linux/kdb.h>
 106 #include <linux/ctype.h>
 107 #include <linux/bsearch.h>
 108 #include <linux/gcd.h>
 109
 110 #define MAX_NR_CON_DRIVER 16
 111
 112 #define CON_DRIVER_FLAG_MODULE 1
 113 #define CON_DRIVER_FLAG_INIT   2
 114 #define CON_DRIVER_FLAG_ATTR   4
 115 #define CON_DRIVER_FLAG_ZOMBIE 8
 116
 117 struct con_driver {
 118         const struct consw *con;
 119         const char *desc;
 120         struct device *dev;
 121         int node;
 122         int first;
 123         int last;
 124         int flag;
 125 };
 126
 127 static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
 128 const struct consw *conswitchp;
 129
 130 /*
 131  * Here is the default bell parameters: 750HZ, 1/8th of a second
 132  */
 133 #define DEFAULT_BELL_PITCH      750
 134 #define DEFAULT_BELL_DURATION   (HZ/8)
 135 #define DEFAULT_CURSOR_BLINK_MS 200
 136
 137 struct vc vc_cons [MAX_NR_CONSOLES];
 138
 139 #ifndef VT_SINGLE_DRIVER
 140 static const struct consw *con_driver_map[MAX_NR_CONSOLES];
 141 #endif
 142
 143 static int con_open(struct tty_struct *, struct file *);
 144 static void vc_init(struct vc_data *vc, unsigned int rows,
 145                     unsigned int cols, int do_clear);
 146 static void gotoxy(struct vc_data *vc, int new_x, int new_y);
 147 static void save_cur(struct vc_data *vc);
 148 static void reset_terminal(struct vc_data *vc, int do_clear);
 149 static void con_flush_chars(struct tty_struct *tty);
 150 static int set_vesa_blanking(char __user *p);
 151 static void set_cursor(struct vc_data *vc);
 152 static void hide_cursor(struct vc_data *vc);
 153 static void console_callback(struct work_struct *ignored);
 154 static void con_driver_unregister_callback(struct work_struct *ignored);
 155 static void blank_screen_t(struct timer_list *unused);
 156 static void set_palette(struct vc_data *vc);
 157 static void unblank_screen(void);
 158
 159 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 160
 161 int default_utf8 = true;
 162 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 163 int global_cursor_default = -1;
 164 module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
 165
 166 static int cur_default = CUR_UNDERLINE;
 167 module_param(cur_default, int, S_IRUGO | S_IWUSR);
 168
 169 /*
 170  * ignore_poke: don't unblank the screen when things are typed.  This is
 171  * mainly for the privacy of braille terminal users.
 172  */
 173 static int ignore_poke;
 174
 175 int do_poke_blanked_console;
 176 int console_blanked;
 177
 178 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
 179 static int vesa_off_interval;
 180 static int blankinterval;
 181 core_param(consoleblank, blankinterval, int, 0444);
 182
 183 static DECLARE_WORK(console_work, console_callback);
 184 static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
 185
 186 /*
 187  * fg_console is the current virtual console,
 188  * last_console is the last used one,
 189  * want_console is the console we want to switch to,
 190  * saved_* variants are for save/restore around kernel debugger enter/leave
 191  */
 192 int fg_console;
 193 int last_console;
 194 int want_console = -1;
 195 static int saved_fg_console;
 196 static int saved_last_console;
 197 static int saved_want_console;
 198 static int saved_vc_mode;
 199 static int saved_console_blanked;
 200
 201 /*
 202  * For each existing display, we have a pointer to console currently visible
 203  * on that display, allowing consoles other than fg_console to be refreshed
 204  * appropriately. Unless the low-level driver supplies its own display_fg
 205  * variable, we use this one for the "master display".
 206  */
 207 static struct vc_data *master_display_fg;
 208
 209 /*
 210  * Unfortunately, we need to delay tty echo when we're currently writing to the
 211  * console since the code is (and always was) not re-entrant, so we schedule
 212  * all flip requests to process context with schedule-task() and run it from
 213  * console_callback().
 214  */
 215
 216 /*
 217  * For the same reason, we defer scrollback to the console callback.
 218  */
 219 static int scrollback_delta;
 220
 221 /*
 222  * Hook so that the power management routines can (un)blank
 223  * the console on our behalf.
 224  */
 225 int (*console_blank_hook)(int);
 226
 227 static DEFINE_TIMER(console_timer, blank_screen_t);
 228 static int blank_state;
 229 static int blank_timer_expired;
 230 enum {
 231         blank_off = 0,
 232         blank_normal_wait,
 233         blank_vesa_wait,
 234 };
 235
 236 /*
 237  * /sys/class/tty/tty0/
 238  *
 239  * the attribute 'active' contains the name of the current vc
 240  * console and it supports poll() to detect vc switches
 241  */
 242 static struct device *tty0dev;
 243
 244 /*
 245  * Notifier list for console events.
 246  */
 247 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
 248
 249 int register_vt_notifier(struct notifier_block *nb)
 250 {
 251         return atomic_notifier_chain_register(&vt_notifier_list, nb);
 252 }
 253 EXPORT_SYMBOL_GPL(register_vt_notifier);
 254
 255 int unregister_vt_notifier(struct notifier_block *nb)
 256 {
 257         return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
 258 }
 259 EXPORT_SYMBOL_GPL(unregister_vt_notifier);
 260
 261 static void notify_write(struct vc_data *vc, unsigned int unicode)
 262 {
 263         struct vt_notifier_param param = { .vc = vc, .c = unicode };
 264         atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
 265 }
 266
 267 static void notify_update(struct vc_data *vc)
 268 {
 269         struct vt_notifier_param param = { .vc = vc };
 270         atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
 271 }
 272 /*
 273  *      Low-Level Functions
 274  */
 275
 276 static inline bool con_is_fg(const struct vc_data *vc)
 277 {
 278         return vc->vc_num == fg_console;
 279 }
 280
 281 static inline bool con_should_update(const struct vc_data *vc)
 282 {
 283         return con_is_visible(vc) && !console_blanked;
 284 }
 285
 286 static inline unsigned short *screenpos(const struct vc_data *vc, int offset,
 287                 bool viewed)
 288 {
 289         unsigned short *p;
 290
 291         if (!viewed)
 292                 p = (unsigned short *)(vc->vc_origin + offset);
 293         else if (!vc->vc_sw->con_screen_pos)
 294                 p = (unsigned short *)(vc->vc_visible_origin + offset);
 295         else
 296                 p = vc->vc_sw->con_screen_pos(vc, offset);
 297         return p;
 298 }
 299
 300 /* Called  from the keyboard irq path.. */
 301 static inline void scrolldelta(int lines)
 302 {
 303         /* FIXME */
 304         /* scrolldelta needs some kind of consistency lock, but the BKL was
 305            and still is not protecting versus the scheduled back end */
 306         scrollback_delta += lines;
 307         schedule_console_callback();
 308 }
 309
 310 void schedule_console_callback(void)
 311 {
 312         schedule_work(&console_work);
 313 }
 314
 315 /*
 316  * Code to manage unicode-based screen buffers
 317  */
 318
 319 /*
 320  * Our screen buffer is preceded by an array of line pointers so that
 321  * scrolling only implies some pointer shuffling.
 322  */
 323
 324 static u32 **vc_uniscr_alloc(unsigned int cols, unsigned int rows)
 325 {
 326         u32 **uni_lines;
 327         void *p;
 328         unsigned int memsize, i, col_size = cols * sizeof(**uni_lines);
 329
 330         /* allocate everything in one go */
 331         memsize = col_size * rows;
 332         memsize += rows * sizeof(*uni_lines);
 333         uni_lines = vzalloc(memsize);
 334         if (!uni_lines)
 335                 return NULL;
 336
 337         /* initial line pointers */
 338         p = uni_lines + rows;
 339         for (i = 0; i < rows; i++) {
 340                 uni_lines[i] = p;
 341                 p += col_size;
 342         }
 343
 344         return uni_lines;
 345 }
 346
 347 static void vc_uniscr_free(u32 **uni_lines)
 348 {
 349         vfree(uni_lines);
 350 }
 351
 352 static void vc_uniscr_set(struct vc_data *vc, u32 **new_uni_lines)
 353 {
 354         vc_uniscr_free(vc->vc_uni_lines);
 355         vc->vc_uni_lines = new_uni_lines;
 356 }
 357
 358 static void vc_uniscr_putc(struct vc_data *vc, u32 uc)
 359 {
 360         if (vc->vc_uni_lines)
 361                 vc->vc_uni_lines[vc->state.y][vc->state.x] = uc;
 362 }
 363
 364 static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
 365 {
 366         if (vc->vc_uni_lines) {
 367                 u32 *ln = vc->vc_uni_lines[vc->state.y];
 368                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 369
 370                 memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
 371                 memset32(&ln[x], ' ', nr);
 372         }
 373 }
 374
 375 static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
 376 {
 377         if (vc->vc_uni_lines) {
 378                 u32 *ln = vc->vc_uni_lines[vc->state.y];
 379                 unsigned int x = vc->state.x, cols = vc->vc_cols;
 380
 381                 memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
 382                 memset32(&ln[cols - nr], ' ', nr);
 383         }
 384 }
 385
 386 static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
 387                                  unsigned int nr)
 388 {
 389         if (vc->vc_uni_lines)
 390                 memset32(&vc->vc_uni_lines[vc->state.y][x], ' ', nr);
 391 }
 392
 393 static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
 394                                   unsigned int nr)
 395 {
 396         if (vc->vc_uni_lines)
 397                 while (nr--)
 398                         memset32(vc->vc_uni_lines[y++], ' ', vc->vc_cols);
 399 }
 400
 401 /* juggling array rotation algorithm (complexity O(N), size complexity O(1)) */
 402 static void juggle_array(u32 **array, unsigned int size, unsigned int nr)
 403 {
 404         unsigned int gcd_idx;
 405
 406         for (gcd_idx = 0; gcd_idx < gcd(nr, size); gcd_idx++) {
 407                 u32 *gcd_idx_val = array[gcd_idx];
 408                 unsigned int dst_idx = gcd_idx;
 409
 410                 while (1) {
 411                         unsigned int src_idx = (dst_idx + nr) % size;
 412                         if (src_idx == gcd_idx)
 413                                 break;
 414
 415                         array[dst_idx] = array[src_idx];
 416                         dst_idx = src_idx;
 417                 }
 418
 419                 array[dst_idx] = gcd_idx_val;
 420         }
 421 }
 422
 423 static void vc_uniscr_scroll(struct vc_data *vc, unsigned int top,
 424                              unsigned int bottom, enum con_scroll dir,
 425                              unsigned int nr)
 426 {
 427         u32 **uni_lines = vc->vc_uni_lines;
 428         unsigned int size = bottom - top;
 429
 430         if (!uni_lines)
 431                 return;
 432
 433         if (dir == SM_DOWN) {
 434                 juggle_array(&uni_lines[top], size, size - nr);
 435                 vc_uniscr_clear_lines(vc, top, nr);
 436         } else {
 437                 juggle_array(&uni_lines[top], size, nr);
 438                 vc_uniscr_clear_lines(vc, bottom - nr, nr);
 439         }
 440 }
 441
 442 static void vc_uniscr_copy_area(u32 **dst_lines,
 443                                 unsigned int dst_cols,
 444                                 unsigned int dst_rows,
 445                                 u32 **src_lines,
 446                                 unsigned int src_cols,
 447                                 unsigned int src_top_row,
 448                                 unsigned int src_bot_row)
 449 {
 450         unsigned int dst_row = 0;
 451
 452         if (!dst_lines)
 453                 return;
 454
 455         while (src_top_row < src_bot_row) {
 456                 u32 *src_line = src_lines[src_top_row];
 457                 u32 *dst_line = dst_lines[dst_row];
 458
 459                 memcpy(dst_line, src_line, src_cols * sizeof(*src_line));
 460                 if (dst_cols - src_cols)
 461                         memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
 462                 src_top_row++;
 463                 dst_row++;
 464         }
 465         while (dst_row < dst_rows) {
 466                 u32 *dst_line = dst_lines[dst_row];
 467
 468                 memset32(dst_line, ' ', dst_cols);
 469                 dst_row++;
 470         }
 471 }
 472
 473 /*
 474  * Called from vcs_read() to make sure unicode screen retrieval is possible.
 475  * This will initialize the unicode screen buffer if not already done.
 476  * This returns 0 if OK, or a negative error code otherwise.
 477  * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
 478  */
 479 int vc_uniscr_check(struct vc_data *vc)
 480 {
 481         u32 **uni_lines;
 482         unsigned short *p;
 483         int x, y, mask;
 484
 485         WARN_CONSOLE_UNLOCKED();
 486
 487         if (!vc->vc_utf)
 488                 return -ENODATA;
 489
 490         if (vc->vc_uni_lines)
 491                 return 0;
 492
 493         uni_lines = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
 494         if (!uni_lines)
 495                 return -ENOMEM;
 496
 497         /*
 498          * Let's populate it initially with (imperfect) reverse translation.
 499          * This is the next best thing we can do short of having it enabled
 500          * from the start even when no users rely on this functionality. True
 501          * unicode content will be available after a complete screen refresh.
 502          */
 503         p = (unsigned short *)vc->vc_origin;
 504         mask = vc->vc_hi_font_mask | 0xff;
 505         for (y = 0; y < vc->vc_rows; y++) {
 506                 u32 *line = uni_lines[y];
 507                 for (x = 0; x < vc->vc_cols; x++) {
 508                         u16 glyph = scr_readw(p++) & mask;
 509                         line[x] = inverse_translate(vc, glyph, true);
 510                 }
 511         }
 512
 513         vc->vc_uni_lines = uni_lines;
 514
 515         return 0;
 516 }
 517
 518 /*
 519  * Called from vcs_read() to get the unicode data from the screen.
 520  * This must be preceded by a successful call to vc_uniscr_check() once
 521  * the console lock has been taken.
 522  */
 523 void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed,
 524                          unsigned int row, unsigned int col, unsigned int nr)
 525 {
 526         u32 **uni_lines = vc->vc_uni_lines;
 527         int offset = row * vc->vc_size_row + col * 2;
 528         unsigned long pos;
 529
 530         if (WARN_ON_ONCE(!uni_lines))
 531                 return;
 532
 533         pos = (unsigned long)screenpos(vc, offset, viewed);
 534         if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
 535                 /*
 536                  * Desired position falls in the main screen buffer.
 537                  * However the actual row/col might be different if
 538                  * scrollback is active.
 539                  */
 540                 row = (pos - vc->vc_origin) / vc->vc_size_row;
 541                 col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
 542                 memcpy(dest, &uni_lines[row][col], nr * sizeof(u32));
 543         } else {
 544                 /*
 545                  * Scrollback is active. For now let's simply backtranslate
 546                  * the screen glyphs until the unicode screen buffer does
 547                  * synchronize with console display drivers for a scrollback
 548                  * buffer of its own.
 549                  */
 550                 u16 *p = (u16 *)pos;
 551                 int mask = vc->vc_hi_font_mask | 0xff;
 552                 u32 *uni_buf = dest;
 553                 while (nr--) {
 554                         u16 glyph = scr_readw(p++) & mask;
 555                         *uni_buf++ = inverse_translate(vc, glyph, true);
 556                 }
 557         }
 558 }
 559
 560 static void con_scroll(struct vc_data *vc, unsigned int top,
 561                        unsigned int bottom, enum con_scroll dir,
 562                        unsigned int nr)
 563 {
 564         unsigned int rows = bottom - top;
 565         u16 *clear, *dst, *src;
 566
 567         if (top + nr >= bottom)
 568                 nr = rows - 1;
 569         if (bottom > vc->vc_rows || top >= bottom || nr < 1)
 570                 return;
 571
 572         vc_uniscr_scroll(vc, top, bottom, dir, nr);
 573         if (con_is_visible(vc) &&
 574                         vc->vc_sw->con_scroll(vc, top, bottom, dir, nr))
 575                 return;
 576
 577         src = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * top);
 578         dst = (u16 *)(vc->vc_origin + vc->vc_size_row * (top + nr));
 579
 580         if (dir == SM_UP) {
 581                 clear = src + (rows - nr) * vc->vc_cols;
 582                 swap(src, dst);
 583         }
 584         scr_memmovew(dst, src, (rows - nr) * vc->vc_size_row);
 585         scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
 586 }
 587
 588 static void do_update_region(struct vc_data *vc, unsigned long start, int count)
 589 {
 590         unsigned int xx, yy, offset;
 591         u16 *p;
 592
 593         p = (u16 *) start;
 594         if (!vc->vc_sw->con_getxy) {
 595                 offset = (start - vc->vc_origin) / 2;
 596                 xx = offset % vc->vc_cols;
 597                 yy = offset / vc->vc_cols;
 598         } else {
 599                 int nxx, nyy;
 600                 start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
 601                 xx = nxx; yy = nyy;
 602         }
 603         for(;;) {
 604                 u16 attrib = scr_readw(p) & 0xff00;
 605                 int startx = xx;
 606                 u16 *q = p;
 607                 while (xx < vc->vc_cols && count) {
 608                         if (attrib != (scr_readw(p) & 0xff00)) {
 609                                 if (p > q)
 610                                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 611                                 startx = xx;
 612                                 q = p;
 613                                 attrib = scr_readw(p) & 0xff00;
 614                         }
 615                         p++;
 616                         xx++;
 617                         count--;
 618                 }
 619                 if (p > q)
 620                         vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
 621                 if (!count)
 622                         break;
 623                 xx = 0;
 624                 yy++;
 625                 if (vc->vc_sw->con_getxy) {
 626                         p = (u16 *)start;
 627                         start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
 628                 }
 629         }
 630 }
 631
 632 void update_region(struct vc_data *vc, unsigned long start, int count)
 633 {
 634         WARN_CONSOLE_UNLOCKED();
 635
 636         if (con_should_update(vc)) {
 637                 hide_cursor(vc);
 638                 do_update_region(vc, start, count);
 639                 set_cursor(vc);
 640         }
 641 }
 642
 643 /* Structure of attributes is hardware-dependent */
 644
 645 static u8 build_attr(struct vc_data *vc, u8 _color,
 646                 enum vc_intensity _intensity, bool _blink, bool _underline,
 647                 bool _reverse, bool _italic)
 648 {
 649         if (vc->vc_sw->con_build_attr)
 650                 return vc->vc_sw->con_build_attr(vc, _color, _intensity,
 651                        _blink, _underline, _reverse, _italic);
 652
 653 /*
 654  * ++roman: I completely changed the attribute format for monochrome
 655  * mode (!can_do_color). The formerly used MDA (monochrome display
 656  * adapter) format didn't allow the combination of certain effects.
 657  * Now the attribute is just a bit vector:
 658  *  Bit 0..1: intensity (0..2)
 659  *  Bit 2   : underline
 660  *  Bit 3   : reverse
 661  *  Bit 7   : blink
 662  */
 663         {
 664         u8 a = _color;
 665         if (!vc->vc_can_do_color)
 666                 return _intensity |
 667                        (_italic    << 1) |
 668                        (_underline << 2) |
 669                        (_reverse   << 3) |
 670                        (_blink     << 7);
 671         if (_italic)
 672                 a = (a & 0xF0) | vc->vc_itcolor;
 673         else if (_underline)
 674                 a = (a & 0xf0) | vc->vc_ulcolor;
 675         else if (_intensity == VCI_HALF_BRIGHT)
 676                 a = (a & 0xf0) | vc->vc_halfcolor;
 677         if (_reverse)
 678                 a = (a & 0x88) | (((a >> 4) | (a << 4)) & 0x77);
 679         if (_blink)
 680                 a ^= 0x80;
 681         if (_intensity == VCI_BOLD)
 682                 a ^= 0x08;
 683         if (vc->vc_hi_font_mask == 0x100)
 684                 a <<= 1;
 685         return a;
 686         }
 687 }
 688
 689 static void update_attr(struct vc_data *vc)
 690 {
 691         vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
 692                       vc->state.blink, vc->state.underline,
 693                       vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
 694         vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
 695                                 VCI_NORMAL, vc->state.blink, false,
 696                                 vc->vc_decscnm, false) << 8);
 697 }
 698
 699 /* Note: inverting the screen twice should revert to the original state */
 700 void invert_screen(struct vc_data *vc, int offset, int count, bool viewed)
 701 {
 702         unsigned short *p;
 703
 704         WARN_CONSOLE_UNLOCKED();
 705
 706         count /= 2;
 707         p = screenpos(vc, offset, viewed);
 708         if (vc->vc_sw->con_invert_region) {
 709                 vc->vc_sw->con_invert_region(vc, p, count);
 710         } else {
 711                 u16 *q = p;
 712                 int cnt = count;
 713                 u16 a;
 714
 715                 if (!vc->vc_can_do_color) {
 716                         while (cnt--) {
 717                             a = scr_readw(q);
 718                             a ^= 0x0800;
 719                             scr_writew(a, q);
 720                             q++;
 721                         }
 722                 } else if (vc->vc_hi_font_mask == 0x100) {
 723                         while (cnt--) {
 724                                 a = scr_readw(q);
 725                                 a = (a & 0x11ff) |
 726                                    ((a & 0xe000) >> 4) |
 727                                    ((a & 0x0e00) << 4);
 728                                 scr_writew(a, q);
 729                                 q++;
 730                         }
 731                 } else {
 732                         while (cnt--) {
 733                                 a = scr_readw(q);
 734                                 a = (a & 0x88ff) |
 735                                    ((a & 0x7000) >> 4) |
 736                                    ((a & 0x0700) << 4);
 737                                 scr_writew(a, q);
 738                                 q++;
 739                         }
 740                 }
 741         }
 742
 743         if (con_should_update(vc))
 744                 do_update_region(vc, (unsigned long) p, count);
 745         notify_update(vc);
 746 }
 747
 748 /* used by selection: complement pointer position */
 749 void complement_pos(struct vc_data *vc, int offset)
 750 {
 751         static int old_offset = -1;
 752         static unsigned short old;
 753         static unsigned short oldx, oldy;
 754
 755         WARN_CONSOLE_UNLOCKED();
 756
 757         if (old_offset != -1 && old_offset >= 0 &&
 758             old_offset < vc->vc_screenbuf_size) {
 759                 scr_writew(old, screenpos(vc, old_offset, true));
 760                 if (con_should_update(vc))
 761                         vc->vc_sw->con_putc(vc, old, oldy, oldx);
 762                 notify_update(vc);
 763         }
 764
 765         old_offset = offset;
 766
 767         if (offset != -1 && offset >= 0 &&
 768             offset < vc->vc_screenbuf_size) {
 769                 unsigned short new;
 770                 unsigned short *p;
 771                 p = screenpos(vc, offset, true);
 772                 old = scr_readw(p);
 773                 new = old ^ vc->vc_complement_mask;
 774                 scr_writew(new, p);
 775                 if (con_should_update(vc)) {
 776                         oldx = (offset >> 1) % vc->vc_cols;
 777                         oldy = (offset >> 1) / vc->vc_cols;
 778                         vc->vc_sw->con_putc(vc, new, oldy, oldx);
 779                 }
 780                 notify_update(vc);
 781         }
 782 }
 783
 784 static void insert_char(struct vc_data *vc, unsigned int nr)
 785 {
 786         unsigned short *p = (unsigned short *) vc->vc_pos;
 787
 788         vc_uniscr_insert(vc, nr);
 789         scr_memmovew(p + nr, p, (vc->vc_cols - vc->state.x - nr) * 2);
 790         scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
 791         vc->vc_need_wrap = 0;
 792         if (con_should_update(vc))
 793                 do_update_region(vc, (unsigned long) p,
 794                         vc->vc_cols - vc->state.x);
 795 }
 796
 797 static void delete_char(struct vc_data *vc, unsigned int nr)
 798 {
 799         unsigned short *p = (unsigned short *) vc->vc_pos;
 800
 801         vc_uniscr_delete(vc, nr);
 802         scr_memmovew(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
 803         scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
 804                         nr * 2);
 805         vc->vc_need_wrap = 0;
 806         if (con_should_update(vc))
 807                 do_update_region(vc, (unsigned long) p,
 808                         vc->vc_cols - vc->state.x);
 809 }
 810
 811 static int softcursor_original = -1;
 812
 813 static void add_softcursor(struct vc_data *vc)
 814 {
 815         int i = scr_readw((u16 *) vc->vc_pos);
 816         u32 type = vc->vc_cursor_type;
 817
 818         if (!(type & CUR_SW))
 819                 return;
 820         if (softcursor_original != -1)
 821                 return;
 822         softcursor_original = i;
 823         i |= CUR_SET(type);
 824         i ^= CUR_CHANGE(type);
 825         if ((type & CUR_ALWAYS_BG) &&
 826                         (softcursor_original & CUR_BG) == (i & CUR_BG))
 827                 i ^= CUR_BG;
 828         if ((type & CUR_INVERT_FG_BG) && (i & CUR_FG) == ((i & CUR_BG) >> 4))
 829                 i ^= CUR_FG;
 830         scr_writew(i, (u16 *)vc->vc_pos);
 831         if (con_should_update(vc))
 832                 vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
 833 }
 834
 835 static void hide_softcursor(struct vc_data *vc)
 836 {
 837         if (softcursor_original != -1) {
 838                 scr_writew(softcursor_original, (u16 *)vc->vc_pos);
 839                 if (con_should_update(vc))
 840                         vc->vc_sw->con_putc(vc, softcursor_original,
 841                                         vc->state.y, vc->state.x);
 842                 softcursor_original = -1;
 843         }
 844 }
 845
 846 static void hide_cursor(struct vc_data *vc)
 847 {
 848         if (vc_is_sel(vc))
 849                 clear_selection();
 850
 851         vc->vc_sw->con_cursor(vc, CM_ERASE);
 852         hide_softcursor(vc);
 853 }
 854
 855 static void set_cursor(struct vc_data *vc)
 856 {
 857         if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
 858                 return;
 859         if (vc->vc_deccm) {
 860                 if (vc_is_sel(vc))
 861                         clear_selection();
 862                 add_softcursor(vc);
 863                 if (CUR_SIZE(vc->vc_cursor_type) != CUR_NONE)
 864                         vc->vc_sw->con_cursor(vc, CM_DRAW);
 865         } else
 866                 hide_cursor(vc);
 867 }
 868
 869 static void set_origin(struct vc_data *vc)
 870 {
 871         WARN_CONSOLE_UNLOCKED();
 872
 873         if (!con_is_visible(vc) ||
 874             !vc->vc_sw->con_set_origin ||
 875             !vc->vc_sw->con_set_origin(vc))
 876                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
 877         vc->vc_visible_origin = vc->vc_origin;
 878         vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
 879         vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->state.y +
 880                 2 * vc->state.x;
 881 }
 882
 883 static void save_screen(struct vc_data *vc)
 884 {
 885         WARN_CONSOLE_UNLOCKED();
 886
 887         if (vc->vc_sw->con_save_screen)
 888                 vc->vc_sw->con_save_screen(vc);
 889 }
 890
 891 static void flush_scrollback(struct vc_data *vc)
 892 {
 893         WARN_CONSOLE_UNLOCKED();
 894
 895         set_origin(vc);
 896         if (vc->vc_sw->con_flush_scrollback) {
 897                 vc->vc_sw->con_flush_scrollback(vc);
 898         } else if (con_is_visible(vc)) {
 899                 /*
 900                  * When no con_flush_scrollback method is provided then the
 901                  * legacy way for flushing the scrollback buffer is to use
 902                  * a side effect of the con_switch method. We do it only on
 903                  * the foreground console as background consoles have no
 904                  * scrollback buffers in that case and we obviously don't
 905                  * want to switch to them.
 906                  */
 907                 hide_cursor(vc);
 908                 vc->vc_sw->con_switch(vc);
 909                 set_cursor(vc);
 910         }
 911 }
 912
 913 /*
 914  *      Redrawing of screen
 915  */
 916
 917 void clear_buffer_attributes(struct vc_data *vc)
 918 {
 919         unsigned short *p = (unsigned short *)vc->vc_origin;
 920         int count = vc->vc_screenbuf_size / 2;
 921         int mask = vc->vc_hi_font_mask | 0xff;
 922
 923         for (; count > 0; count--, p++) {
 924                 scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
 925         }
 926 }
 927
 928 void redraw_screen(struct vc_data *vc, int is_switch)
 929 {
 930         int redraw = 0;
 931
 932         WARN_CONSOLE_UNLOCKED();
 933
 934         if (!vc) {
 935                 /* strange ... */
 936                 /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
 937                 return;
 938         }
 939
 940         if (is_switch) {
 941                 struct vc_data *old_vc = vc_cons[fg_console].d;
 942                 if (old_vc == vc)
 943                         return;
 944                 if (!con_is_visible(vc))
 945                         redraw = 1;
 946                 *vc->vc_display_fg = vc;
 947                 fg_console = vc->vc_num;
 948                 hide_cursor(old_vc);
 949                 if (!con_is_visible(old_vc)) {
 950                         save_screen(old_vc);
 951                         set_origin(old_vc);
 952                 }
 953                 if (tty0dev)
 954                         sysfs_notify(&tty0dev->kobj, NULL, "active");
 955         } else {
 956                 hide_cursor(vc);
 957                 redraw = 1;
 958         }
 959
 960         if (redraw) {
 961                 int update;
 962                 int old_was_color = vc->vc_can_do_color;
 963
 964                 set_origin(vc);
 965                 update = vc->vc_sw->con_switch(vc);
 966                 set_palette(vc);
 967                 /*
 968                  * If console changed from mono<->color, the best we can do
 969                  * is to clear the buffer attributes. As it currently stands,
 970                  * rebuilding new attributes from the old buffer is not doable
 971                  * without overly complex code.
 972                  */
 973                 if (old_was_color != vc->vc_can_do_color) {
 974                         update_attr(vc);
 975                         clear_buffer_attributes(vc);
 976                 }
 977
 978                 if (update && vc->vc_mode != KD_GRAPHICS)
 979                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
 980         }
 981         set_cursor(vc);
 982         if (is_switch) {
 983                 vt_set_leds_compute_shiftstate();
 984                 notify_update(vc);
 985         }
 986 }
 987
 988 /*
 989  *      Allocation, freeing and resizing of VTs.
 990  */
 991
 992 int vc_cons_allocated(unsigned int i)
 993 {
 994         return (i < MAX_NR_CONSOLES && vc_cons[i].d);
 995 }
 996
 997 static void visual_init(struct vc_data *vc, int num, int init)
 998 {
 999         /* ++Geert: vc->vc_sw->con_init determines console size */
1000         if (vc->vc_sw)
1001                 module_put(vc->vc_sw->owner);
1002         vc->vc_sw = conswitchp;
1003 #ifndef VT_SINGLE_DRIVER
1004         if (con_driver_map[num])
1005                 vc->vc_sw = con_driver_map[num];
1006 #endif
1007         __module_get(vc->vc_sw->owner);
1008         vc->vc_num = num;
1009         vc->vc_display_fg = &master_display_fg;
1010         if (vc->uni_pagedict_loc)
1011                 con_free_unimap(vc);
1012         vc->uni_pagedict_loc = &vc->uni_pagedict;
1013         vc->uni_pagedict = NULL;
1014         vc->vc_hi_font_mask = 0;
1015         vc->vc_complement_mask = 0;
1016         vc->vc_can_do_color = 0;
1017         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1018         vc->vc_sw->con_init(vc, init);
1019         if (!vc->vc_complement_mask)
1020                 vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
1021         vc->vc_s_complement_mask = vc->vc_complement_mask;
1022         vc->vc_size_row = vc->vc_cols << 1;
1023         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
1024 }
1025
1026
1027 static void visual_deinit(struct vc_data *vc)
1028 {
1029         vc->vc_sw->con_deinit(vc);
1030         module_put(vc->vc_sw->owner);
1031 }
1032
1033 static void vc_port_destruct(struct tty_port *port)
1034 {
1035         struct vc_data *vc = container_of(port, struct vc_data, port);
1036
1037         kfree(vc);
1038 }
1039
1040 static const struct tty_port_operations vc_port_ops = {
1041         .destruct = vc_port_destruct,
1042 };
1043
1044 /*
1045  * Change # of rows and columns (0 means unchanged/the size of fg_console)
1046  * [this is to be used together with some user program
1047  * like resize that changes the hardware videomode]
1048  */
1049 #define VC_MAXCOL (32767)
1050 #define VC_MAXROW (32767)
1051
1052 int vc_allocate(unsigned int currcons)  /* return 0 on success */
1053 {
1054         struct vt_notifier_param param;
1055         struct vc_data *vc;
1056         int err;
1057
1058         WARN_CONSOLE_UNLOCKED();
1059
1060         if (currcons >= MAX_NR_CONSOLES)
1061                 return -ENXIO;
1062
1063         if (vc_cons[currcons].d)
1064                 return 0;
1065
1066         /* due to the granularity of kmalloc, we waste some memory here */
1067         /* the alloc is done in two steps, to optimize the common situation
1068            of a 25x80 console (structsize=216, screenbuf_size=4000) */
1069         /* although the numbers above are not valid since long ago, the
1070            point is still up-to-date and the comment still has its value
1071            even if only as a historical artifact.  --mj, July 1998 */
1072         param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
1073         if (!vc)
1074                 return -ENOMEM;
1075
1076         vc_cons[currcons].d = vc;
1077         tty_port_init(&vc->port);
1078         vc->port.ops = &vc_port_ops;
1079         INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
1080
1081         visual_init(vc, currcons, 1);
1082
1083         if (!*vc->uni_pagedict_loc)
1084                 con_set_default_unimap(vc);
1085
1086         err = -EINVAL;
1087         if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
1088             vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
1089                 goto err_free;
1090         err = -ENOMEM;
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         visual_deinit(vc);
1107         kfree(vc);
1108         vc_cons[currcons].d = NULL;
1109         return err;
1110 }
1111
1112 static inline int resize_screen(struct vc_data *vc, int width, int height,
1113                                 int user)
1114 {
1115         /* Resizes the resolution of the display adapater */
1116         int err = 0;
1117
1118         if (vc->vc_sw->con_resize)
1119                 err = vc->vc_sw->con_resize(vc, width, height, user);
1120
1121         return err;
1122 }
1123
1124 /**
1125  *      vc_do_resize    -       resizing method for the tty
1126  *      @tty: tty being resized
1127  *      @vc: virtual console private data
1128  *      @cols: columns
1129  *      @lines: lines
1130  *
1131  *      Resize a virtual console, clipping according to the actual constraints.
1132  *      If the caller passes a tty structure then update the termios winsize
1133  *      information and perform any necessary signal handling.
1134  *
1135  *      Caller must hold the console semaphore. Takes the termios rwsem and
1136  *      ctrl.lock of the tty IFF a tty is passed.
1137  */
1138
1139 static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
1140                                 unsigned int cols, unsigned int lines)
1141 {
1142         unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
1143         unsigned long end;
1144         unsigned int old_rows, old_row_size, first_copied_row;
1145         unsigned int new_cols, new_rows, new_row_size, new_screen_size;
1146         unsigned int user;
1147         unsigned short *oldscreen, *newscreen;
1148         u32 **new_uniscr = NULL;
1149
1150         WARN_CONSOLE_UNLOCKED();
1151
1152         if (!vc)
1153                 return -ENXIO;
1154
1155         user = vc->vc_resize_user;
1156         vc->vc_resize_user = 0;
1157
1158         if (cols > VC_MAXCOL || lines > VC_MAXROW)
1159                 return -EINVAL;
1160
1161         new_cols = (cols ? cols : vc->vc_cols);
1162         new_rows = (lines ? lines : vc->vc_rows);
1163         new_row_size = new_cols << 1;
1164         new_screen_size = new_row_size * new_rows;
1165
1166         if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) {
1167                 /*
1168                  * This function is being called here to cover the case
1169                  * where the userspace calls the FBIOPUT_VSCREENINFO twice,
1170                  * passing the same fb_var_screeninfo containing the fields
1171                  * yres/xres equal to a number non-multiple of vc_font.height
1172                  * and yres_virtual/xres_virtual equal to number lesser than the
1173                  * vc_font.height and yres/xres.
1174                  * In the second call, the struct fb_var_screeninfo isn't
1175                  * being modified by the underlying driver because of the
1176                  * if above, and this causes the fbcon_display->vrows to become
1177                  * negative and it eventually leads to out-of-bound
1178                  * access by the imageblit function.
1179                  * To give the correct values to the struct and to not have
1180                  * to deal with possible errors from the code below, we call
1181                  * the resize_screen here as well.
1182                  */
1183                 return resize_screen(vc, new_cols, new_rows, user);
1184         }
1185
1186         if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
1187                 return -EINVAL;
1188         newscreen = kzalloc(new_screen_size, GFP_USER);
1189         if (!newscreen)
1190                 return -ENOMEM;
1191
1192         if (vc->vc_uni_lines) {
1193                 new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
1194                 if (!new_uniscr) {
1195                         kfree(newscreen);
1196                         return -ENOMEM;
1197                 }
1198         }
1199
1200         if (vc_is_sel(vc))
1201                 clear_selection();
1202
1203         old_rows = vc->vc_rows;
1204         old_row_size = vc->vc_size_row;
1205
1206         err = resize_screen(vc, new_cols, new_rows, user);
1207         if (err) {
1208                 kfree(newscreen);
1209                 vc_uniscr_free(new_uniscr);
1210                 return err;
1211         }
1212
1213         vc->vc_rows = new_rows;
1214         vc->vc_cols = new_cols;
1215         vc->vc_size_row = new_row_size;
1216         vc->vc_screenbuf_size = new_screen_size;
1217
1218         rlth = min(old_row_size, new_row_size);
1219         rrem = new_row_size - rlth;
1220         old_origin = vc->vc_origin;
1221         new_origin = (long) newscreen;
1222         new_scr_end = new_origin + new_screen_size;
1223
1224         if (vc->state.y > new_rows) {
1225                 if (old_rows - vc->state.y < new_rows) {
1226                         /*
1227                          * Cursor near the bottom, copy contents from the
1228                          * bottom of buffer
1229                          */
1230                         first_copied_row = (old_rows - new_rows);
1231                 } else {
1232                         /*
1233                          * Cursor is in no man's land, copy 1/2 screenful
1234                          * from the top and bottom of cursor position
1235                          */
1236                         first_copied_row = (vc->state.y - new_rows/2);
1237                 }
1238                 old_origin += first_copied_row * old_row_size;
1239         } else
1240                 first_copied_row = 0;
1241         end = old_origin + old_row_size * min(old_rows, new_rows);
1242
1243         vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
1244                             vc->vc_uni_lines, rlth/2, first_copied_row,
1245                             min(old_rows, new_rows));
1246         vc_uniscr_set(vc, new_uniscr);
1247
1248         update_attr(vc);
1249
1250         while (old_origin < end) {
1251                 scr_memcpyw((unsigned short *) new_origin,
1252                             (unsigned short *) old_origin, rlth);
1253                 if (rrem)
1254                         scr_memsetw((void *)(new_origin + rlth),
1255                                     vc->vc_video_erase_char, rrem);
1256                 old_origin += old_row_size;
1257                 new_origin += new_row_size;
1258         }
1259         if (new_scr_end > new_origin)
1260                 scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
1261                             new_scr_end - new_origin);
1262         oldscreen = vc->vc_screenbuf;
1263         vc->vc_screenbuf = newscreen;
1264         vc->vc_screenbuf_size = new_screen_size;
1265         set_origin(vc);
1266         kfree(oldscreen);
1267
1268         /* do part of a reset_terminal() */
1269         vc->vc_top = 0;
1270         vc->vc_bottom = vc->vc_rows;
1271         gotoxy(vc, vc->state.x, vc->state.y);
1272         save_cur(vc);
1273
1274         if (tty) {
1275                 /* Rewrite the requested winsize data with the actual
1276                    resulting sizes */
1277                 struct winsize ws;
1278                 memset(&ws, 0, sizeof(ws));
1279                 ws.ws_row = vc->vc_rows;
1280                 ws.ws_col = vc->vc_cols;
1281                 ws.ws_ypixel = vc->vc_scan_lines;
1282                 tty_do_resize(tty, &ws);
1283         }
1284
1285         if (con_is_visible(vc))
1286                 update_screen(vc);
1287         vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
1288         notify_update(vc);
1289         return err;
1290 }
1291
1292 /**
1293  *      vc_resize               -       resize a VT
1294  *      @vc: virtual console
1295  *      @cols: columns
1296  *      @rows: rows
1297  *
1298  *      Resize a virtual console as seen from the console end of things. We
1299  *      use the common vc_do_resize methods to update the structures. The
1300  *      caller must hold the console sem to protect console internals and
1301  *      vc->port.tty
1302  */
1303
1304 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
1305 {
1306         return vc_do_resize(vc->port.tty, vc, cols, rows);
1307 }
1308
1309 /**
1310  *      vt_resize               -       resize a VT
1311  *      @tty: tty to resize
1312  *      @ws: winsize attributes
1313  *
1314  *      Resize a virtual terminal. This is called by the tty layer as we
1315  *      register our own handler for resizing. The mutual helper does all
1316  *      the actual work.
1317  *
1318  *      Takes the console sem and the called methods then take the tty
1319  *      termios_rwsem and the tty ctrl.lock in that order.
1320  */
1321 static int vt_resize(struct tty_struct *tty, struct winsize *ws)
1322 {
1323         struct vc_data *vc = tty->driver_data;
1324         int ret;
1325
1326         console_lock();
1327         ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
1328         console_unlock();
1329         return ret;
1330 }
1331
1332 struct vc_data *vc_deallocate(unsigned int currcons)
1333 {
1334         struct vc_data *vc = NULL;
1335
1336         WARN_CONSOLE_UNLOCKED();
1337
1338         if (vc_cons_allocated(currcons)) {
1339                 struct vt_notifier_param param;
1340
1341                 param.vc = vc = vc_cons[currcons].d;
1342                 atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
1343                 vcs_remove_sysfs(currcons);
1344                 visual_deinit(vc);
1345                 con_free_unimap(vc);
1346                 put_pid(vc->vt_pid);
1347                 vc_uniscr_set(vc, NULL);
1348                 kfree(vc->vc_screenbuf);
1349                 vc_cons[currcons].d = NULL;
1350         }
1351         return vc;
1352 }
1353
1354 /*
1355  *      VT102 emulator
1356  */
1357
1358 enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
1359
1360 #define set_kbd(vc, x)  vt_set_kbd_mode_bit((vc)->vc_num, (x))
1361 #define clr_kbd(vc, x)  vt_clr_kbd_mode_bit((vc)->vc_num, (x))
1362 #define is_kbd(vc, x)   vt_get_kbd_mode_bit((vc)->vc_num, (x))
1363
1364 #define decarm          VC_REPEAT
1365 #define decckm          VC_CKMODE
1366 #define kbdapplic       VC_APPLIC
1367 #define lnm             VC_CRLF
1368
1369 const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
1370                                        8,12,10,14, 9,13,11,15 };
1371
1372 /* the default colour table, for VGA+ colour systems */
1373 unsigned char default_red[] = {
1374         0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
1375         0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
1376 };
1377 module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
1378
1379 unsigned char default_grn[] = {
1380         0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
1381         0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
1382 };
1383 module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
1384
1385 unsigned char default_blu[] = {
1386         0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
1387         0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
1388 };
1389 module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
1390
1391 /*
1392  * gotoxy() must verify all boundaries, because the arguments
1393  * might also be negative. If the given position is out of
1394  * bounds, the cursor is placed at the nearest margin.
1395  */
1396 static void gotoxy(struct vc_data *vc, int new_x, int new_y)
1397 {
1398         int min_y, max_y;
1399
1400         if (new_x < 0)
1401                 vc->state.x = 0;
1402         else {
1403                 if (new_x >= vc->vc_cols)
1404                         vc->state.x = vc->vc_cols - 1;
1405                 else
1406                         vc->state.x = new_x;
1407         }
1408
1409         if (vc->vc_decom) {
1410                 min_y = vc->vc_top;
1411                 max_y = vc->vc_bottom;
1412         } else {
1413                 min_y = 0;
1414                 max_y = vc->vc_rows;
1415         }
1416         if (new_y < min_y)
1417                 vc->state.y = min_y;
1418         else if (new_y >= max_y)
1419                 vc->state.y = max_y - 1;
1420         else
1421                 vc->state.y = new_y;
1422         vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
1423                 (vc->state.x << 1);
1424         vc->vc_need_wrap = 0;
1425 }
1426
1427 /* for absolute user moves, when decom is set */
1428 static void gotoxay(struct vc_data *vc, int new_x, int new_y)
1429 {
1430         gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
1431 }
1432
1433 void scrollback(struct vc_data *vc)
1434 {
1435         scrolldelta(-(vc->vc_rows / 2));
1436 }
1437
1438 void scrollfront(struct vc_data *vc, int lines)
1439 {
1440         if (!lines)
1441                 lines = vc->vc_rows / 2;
1442         scrolldelta(lines);
1443 }
1444
1445 static void lf(struct vc_data *vc)
1446 {
1447         /* don't scroll if above bottom of scrolling region, or
1448          * if below scrolling region
1449          */
1450         if (vc->state.y + 1 == vc->vc_bottom)
1451                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
1452         else if (vc->state.y < vc->vc_rows - 1) {
1453                 vc->state.y++;
1454                 vc->vc_pos += vc->vc_size_row;
1455         }
1456         vc->vc_need_wrap = 0;
1457         notify_write(vc, '\n');
1458 }
1459
1460 static void ri(struct vc_data *vc)
1461 {
1462         /* don't scroll if below top of scrolling region, or
1463          * if above scrolling region
1464          */
1465         if (vc->state.y == vc->vc_top)
1466                 con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
1467         else if (vc->state.y > 0) {
1468                 vc->state.y--;
1469                 vc->vc_pos -= vc->vc_size_row;
1470         }
1471         vc->vc_need_wrap = 0;
1472 }
1473
1474 static inline void cr(struct vc_data *vc)
1475 {
1476         vc->vc_pos -= vc->state.x << 1;
1477         vc->vc_need_wrap = vc->state.x = 0;
1478         notify_write(vc, '\r');
1479 }
1480
1481 static inline void bs(struct vc_data *vc)
1482 {
1483         if (vc->state.x) {
1484                 vc->vc_pos -= 2;
1485                 vc->state.x--;
1486                 vc->vc_need_wrap = 0;
1487                 notify_write(vc, '\b');
1488         }
1489 }
1490
1491 static inline void del(struct vc_data *vc)
1492 {
1493         /* ignored */
1494 }
1495
1496 static void csi_J(struct vc_data *vc, int vpar)
1497 {
1498         unsigned int count;
1499         unsigned short * start;
1500
1501         switch (vpar) {
1502                 case 0: /* erase from cursor to end of display */
1503                         vc_uniscr_clear_line(vc, vc->state.x,
1504                                              vc->vc_cols - vc->state.x);
1505                         vc_uniscr_clear_lines(vc, vc->state.y + 1,
1506                                               vc->vc_rows - vc->state.y - 1);
1507                         count = (vc->vc_scr_end - vc->vc_pos) >> 1;
1508                         start = (unsigned short *)vc->vc_pos;
1509                         break;
1510                 case 1: /* erase from start to cursor */
1511                         vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
1512                         vc_uniscr_clear_lines(vc, 0, vc->state.y);
1513                         count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
1514                         start = (unsigned short *)vc->vc_origin;
1515                         break;
1516                 case 3: /* include scrollback */
1517                         flush_scrollback(vc);
1518                         fallthrough;
1519                 case 2: /* erase whole display */
1520                         vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
1521                         count = vc->vc_cols * vc->vc_rows;
1522                         start = (unsigned short *)vc->vc_origin;
1523                         break;
1524                 default:
1525                         return;
1526         }
1527         scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
1528         if (con_should_update(vc))
1529                 do_update_region(vc, (unsigned long) start, count);
1530         vc->vc_need_wrap = 0;
1531 }
1532
1533 static void csi_K(struct vc_data *vc, int vpar)
1534 {
1535         unsigned int count;
1536         unsigned short *start = (unsigned short *)vc->vc_pos;
1537         int offset;
1538
1539         switch (vpar) {
1540                 case 0: /* erase from cursor to end of line */
1541                         offset = 0;
1542                         count = vc->vc_cols - vc->state.x;
1543                         break;
1544                 case 1: /* erase from start of line to cursor */
1545                         offset = -vc->state.x;
1546                         count = vc->state.x + 1;
1547                         break;
1548                 case 2: /* erase whole line */
1549                         offset = -vc->state.x;
1550                         count = vc->vc_cols;
1551                         break;
1552                 default:
1553                         return;
1554         }
1555         vc_uniscr_clear_line(vc, vc->state.x + offset, count);
1556         scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
1557         vc->vc_need_wrap = 0;
1558         if (con_should_update(vc))
1559                 do_update_region(vc, (unsigned long)(start + offset), count);
1560 }
1561
1562 /* erase the following vpar positions */
1563 static void csi_X(struct vc_data *vc, unsigned int vpar)
1564 {                                         /* not vt100? */
1565         unsigned int count;
1566
1567         if (!vpar)
1568                 vpar++;
1569
1570         count = min(vpar, vc->vc_cols - vc->state.x);
1571
1572         vc_uniscr_clear_line(vc, vc->state.x, count);
1573         scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
1574         if (con_should_update(vc))
1575                 vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
1576         vc->vc_need_wrap = 0;
1577 }
1578
1579 static void default_attr(struct vc_data *vc)
1580 {
1581         vc->state.intensity = VCI_NORMAL;
1582         vc->state.italic = false;
1583         vc->state.underline = false;
1584         vc->state.reverse = false;
1585         vc->state.blink = false;
1586         vc->state.color = vc->vc_def_color;
1587 }
1588
1589 struct rgb { u8 r; u8 g; u8 b; };
1590
1591 static void rgb_from_256(int i, struct rgb *c)
1592 {
1593         if (i < 8) {            /* Standard colours. */
1594                 c->r = i&1 ? 0xaa : 0x00;
1595                 c->g = i&2 ? 0xaa : 0x00;
1596                 c->b = i&4 ? 0xaa : 0x00;
1597         } else if (i < 16) {
1598                 c->r = i&1 ? 0xff : 0x55;
1599                 c->g = i&2 ? 0xff : 0x55;
1600                 c->b = i&4 ? 0xff : 0x55;
1601         } else if (i < 232) {   /* 6x6x6 colour cube. */
1602                 c->r = (i - 16) / 36 * 85 / 2;
1603                 c->g = (i - 16) / 6 % 6 * 85 / 2;
1604                 c->b = (i - 16) % 6 * 85 / 2;
1605         } else                  /* Grayscale ramp. */
1606                 c->r = c->g = c->b = i * 10 - 2312;
1607 }
1608
1609 static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
1610 {
1611         u8 hue = 0, max = max3(c->r, c->g, c->b);
1612
1613         if (c->r > max / 2)
1614                 hue |= 4;
1615         if (c->g > max / 2)
1616                 hue |= 2;
1617         if (c->b > max / 2)
1618                 hue |= 1;
1619
1620         if (hue == 7 && max <= 0x55) {
1621                 hue = 0;
1622                 vc->state.intensity = VCI_BOLD;
1623         } else if (max > 0xaa)
1624                 vc->state.intensity = VCI_BOLD;
1625         else
1626                 vc->state.intensity = VCI_NORMAL;
1627
1628         vc->state.color = (vc->state.color & 0xf0) | hue;
1629 }
1630
1631 static void rgb_background(struct vc_data *vc, const struct rgb *c)
1632 {
1633         /* For backgrounds, err on the dark side. */
1634         vc->state.color = (vc->state.color & 0x0f)
1635                 | (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
1636 }
1637
1638 /*
1639  * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
1640  * and thus need to be detected and ignored by hand. That standard also
1641  * wants : rather than ; as separators but sequences containing : are currently
1642  * completely ignored by the parser.
1643  *
1644  * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
1645  * supporting them.
1646  */
1647 static int vc_t416_color(struct vc_data *vc, int i,
1648                 void(*set_color)(struct vc_data *vc, const struct rgb *c))
1649 {
1650         struct rgb c;
1651
1652         i++;
1653         if (i > vc->vc_npar)
1654                 return i;
1655
1656         if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
1657                 /* 256 colours */
1658                 i++;
1659                 rgb_from_256(vc->vc_par[i], &c);
1660         } else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
1661                 /* 24 bit */
1662                 c.r = vc->vc_par[i + 1];
1663                 c.g = vc->vc_par[i + 2];
1664                 c.b = vc->vc_par[i + 3];
1665                 i += 3;
1666         } else
1667                 return i;
1668
1669         set_color(vc, &c);
1670
1671         return i;
1672 }
1673
1674 /* console_lock is held */
1675 static void csi_m(struct vc_data *vc)
1676 {
1677         int i;
1678
1679         for (i = 0; i <= vc->vc_npar; i++)
1680                 switch (vc->vc_par[i]) {
1681                 case 0: /* all attributes off */
1682                         default_attr(vc);
1683                         break;
1684                 case 1:
1685                         vc->state.intensity = VCI_BOLD;
1686                         break;
1687                 case 2:
1688                         vc->state.intensity = VCI_HALF_BRIGHT;
1689                         break;
1690                 case 3:
1691                         vc->state.italic = true;
1692                         break;
1693                 case 21:
1694                         /*
1695                          * No console drivers support double underline, so
1696                          * convert it to a single underline.
1697                          */
1698                 case 4:
1699                         vc->state.underline = true;
1700                         break;
1701                 case 5:
1702                         vc->state.blink = true;
1703                         break;
1704                 case 7:
1705                         vc->state.reverse = true;
1706                         break;
1707                 case 10: /* ANSI X3.64-1979 (SCO-ish?)
1708                           * Select primary font, don't display control chars if
1709                           * defined, don't set bit 8 on output.
1710                           */
1711                         vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset], vc);
1712                         vc->vc_disp_ctrl = 0;
1713                         vc->vc_toggle_meta = 0;
1714                         break;
1715                 case 11: /* ANSI X3.64-1979 (SCO-ish?)
1716                           * Select first alternate font, lets chars < 32 be
1717                           * displayed as ROM chars.
1718                           */
1719                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1720                         vc->vc_disp_ctrl = 1;
1721                         vc->vc_toggle_meta = 0;
1722                         break;
1723                 case 12: /* ANSI X3.64-1979 (SCO-ish?)
1724                           * Select second alternate font, toggle high bit
1725                           * before displaying as ROM char.
1726                           */
1727                         vc->vc_translate = set_translate(IBMPC_MAP, vc);
1728                         vc->vc_disp_ctrl = 1;
1729                         vc->vc_toggle_meta = 1;
1730                         break;
1731                 case 22:
1732                         vc->state.intensity = VCI_NORMAL;
1733                         break;
1734                 case 23:
1735                         vc->state.italic = false;
1736                         break;
1737                 case 24:
1738                         vc->state.underline = false;
1739                         break;
1740                 case 25:
1741                         vc->state.blink = false;
1742                         break;
1743                 case 27:
1744                         vc->state.reverse = false;
1745                         break;
1746                 case 38:
1747                         i = vc_t416_color(vc, i, rgb_foreground);
1748                         break;
1749                 case 48:
1750                         i = vc_t416_color(vc, i, rgb_background);
1751                         break;
1752                 case 39:
1753                         vc->state.color = (vc->vc_def_color & 0x0f) |
1754                                 (vc->state.color & 0xf0);
1755                         break;
1756                 case 49:
1757                         vc->state.color = (vc->vc_def_color & 0xf0) |
1758                                 (vc->state.color & 0x0f);
1759                         break;
1760                 default:
1761                         if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
1762                                 if (vc->vc_par[i] < 100)
1763                                         vc->state.intensity = VCI_BOLD;
1764                                 vc->vc_par[i] -= 60;
1765                         }
1766                         if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
1767                                 vc->state.color = color_table[vc->vc_par[i] - 30]
1768                                         | (vc->state.color & 0xf0);
1769                         else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
1770                                 vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
1771                                         | (vc->state.color & 0x0f);
1772                         break;
1773                 }
1774         update_attr(vc);
1775 }
1776
1777 static void respond_string(const char *p, size_t len, struct tty_port *port)
1778 {
1779         tty_insert_flip_string(port, p, len);
1780         tty_flip_buffer_push(port);
1781 }
1782
1783 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
1784 {
1785         char buf[40];
1786         int len;
1787
1788         len = sprintf(buf, "\033[%d;%dR", vc->state.y +
1789                         (vc->vc_decom ? vc->vc_top + 1 : 1),
1790                         vc->state.x + 1);
1791         respond_string(buf, len, tty->port);
1792 }
1793
1794 static inline void status_report(struct tty_struct *tty)
1795 {
1796         static const char teminal_ok[] = "\033[0n";
1797
1798         respond_string(teminal_ok, strlen(teminal_ok), tty->port);
1799 }
1800
1801 static inline void respond_ID(struct tty_struct *tty)
1802 {
1803         /* terminal answer to an ESC-Z or csi0c query. */
1804         static const char vt102_id[] = "\033[?6c";
1805
1806         respond_string(vt102_id, strlen(vt102_id), tty->port);
1807 }
1808
1809 void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
1810 {
1811         char buf[8];
1812         int len;
1813
1814         len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
1815                         (char)('!' + mrx), (char)('!' + mry));
1816         respond_string(buf, len, tty->port);
1817 }
1818
1819 /* invoked via ioctl(TIOCLINUX) and through set_selection_user */
1820 int mouse_reporting(void)
1821 {
1822         return vc_cons[fg_console].d->vc_report_mouse;
1823 }
1824
1825 /* console_lock is held */
1826 static void set_mode(struct vc_data *vc, int on_off)
1827 {
1828         int i;
1829
1830         for (i = 0; i <= vc->vc_npar; i++)
1831                 if (vc->vc_priv == EPdec) {
1832                         switch(vc->vc_par[i]) { /* DEC private modes set/reset */
1833                         case 1:                 /* Cursor keys send ^[Ox/^[[x */
1834                                 if (on_off)
1835                                         set_kbd(vc, decckm);
1836                                 else
1837                                         clr_kbd(vc, decckm);
1838                                 break;
1839                         case 3: /* 80/132 mode switch unimplemented */
1840 #if 0
1841                                 vc_resize(deccolm ? 132 : 80, vc->vc_rows);
1842                                 /* this alone does not suffice; some user mode
1843                                    utility has to change the hardware regs */
1844 #endif
1845                                 break;
1846                         case 5:                 /* Inverted screen on/off */
1847                                 if (vc->vc_decscnm != on_off) {
1848                                         vc->vc_decscnm = on_off;
1849                                         invert_screen(vc, 0,
1850                                                         vc->vc_screenbuf_size,
1851                                                         false);
1852                                         update_attr(vc);
1853                                 }
1854                                 break;
1855                         case 6:                 /* Origin relative/absolute */
1856                                 vc->vc_decom = on_off;
1857                                 gotoxay(vc, 0, 0);
1858                                 break;
1859                         case 7:                 /* Autowrap on/off */
1860                                 vc->vc_decawm = on_off;
1861                                 break;
1862                         case 8:                 /* Autorepeat on/off */
1863                                 if (on_off)
1864                                         set_kbd(vc, decarm);
1865                                 else
1866                                         clr_kbd(vc, decarm);
1867                                 break;
1868                         case 9:
1869                                 vc->vc_report_mouse = on_off ? 1 : 0;
1870                                 break;
1871                         case 25:                /* Cursor on/off */
1872                                 vc->vc_deccm = on_off;
1873                                 break;
1874                         case 1000:
1875                                 vc->vc_report_mouse = on_off ? 2 : 0;
1876                                 break;
1877                         }
1878                 } else {
1879                         switch(vc->vc_par[i]) { /* ANSI modes set/reset */
1880                         case 3:                 /* Monitor (display ctrls) */
1881                                 vc->vc_disp_ctrl = on_off;
1882                                 break;
1883                         case 4:                 /* Insert Mode on/off */
1884                                 vc->vc_decim = on_off;
1885                                 break;
1886                         case 20:                /* Lf, Enter == CrLf/Lf */
1887                                 if (on_off)
1888                                         set_kbd(vc, lnm);
1889                                 else
1890                                         clr_kbd(vc, lnm);
1891                                 break;
1892                         }
1893                 }
1894 }
1895
1896 /* console_lock is held */
1897 static void setterm_command(struct vc_data *vc)
1898 {
1899         switch (vc->vc_par[0]) {
1900         case 1: /* set color for underline mode */
1901                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1902                         vc->vc_ulcolor = color_table[vc->vc_par[1]];
1903                         if (vc->state.underline)
1904                                 update_attr(vc);
1905                 }
1906                 break;
1907         case 2: /* set color for half intensity mode */
1908                 if (vc->vc_can_do_color && vc->vc_par[1] < 16) {
1909                         vc->vc_halfcolor = color_table[vc->vc_par[1]];
1910                         if (vc->state.intensity == VCI_HALF_BRIGHT)
1911                                 update_attr(vc);
1912                 }
1913                 break;
1914         case 8: /* store colors as defaults */
1915                 vc->vc_def_color = vc->vc_attr;
1916                 if (vc->vc_hi_font_mask == 0x100)
1917                         vc->vc_def_color >>= 1;
1918                 default_attr(vc);
1919                 update_attr(vc);
1920                 break;
1921         case 9: /* set blanking interval */
1922                 blankinterval = min(vc->vc_par[1], 60U) * 60;
1923                 poke_blanked_console();
1924                 break;
1925         case 10: /* set bell frequency in Hz */
1926                 if (vc->vc_npar >= 1)
1927                         vc->vc_bell_pitch = vc->vc_par[1];
1928                 else
1929                         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
1930                 break;
1931         case 11: /* set bell duration in msec */
1932                 if (vc->vc_npar >= 1)
1933                         vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
1934                                 msecs_to_jiffies(vc->vc_par[1]) : 0;
1935                 else
1936                         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
1937                 break;
1938         case 12: /* bring specified console to the front */
1939                 if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
1940                         set_console(vc->vc_par[1] - 1);
1941                 break;
1942         case 13: /* unblank the screen */
1943                 poke_blanked_console();
1944                 break;
1945         case 14: /* set vesa powerdown interval */
1946                 vesa_off_interval = min(vc->vc_par[1], 60U) * 60 * HZ;
1947                 break;
1948         case 15: /* activate the previous console */
1949                 set_console(last_console);
1950                 break;
1951         case 16: /* set cursor blink duration in msec */
1952                 if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
1953                                 vc->vc_par[1] <= USHRT_MAX)
1954                         vc->vc_cur_blink_ms = vc->vc_par[1];
1955                 else
1956                         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
1957                 break;
1958         }
1959 }
1960
1961 /* console_lock is held */
1962 static void csi_at(struct vc_data *vc, unsigned int nr)
1963 {
1964         if (nr > vc->vc_cols - vc->state.x)
1965                 nr = vc->vc_cols - vc->state.x;
1966         else if (!nr)
1967                 nr = 1;
1968         insert_char(vc, nr);
1969 }
1970
1971 /* console_lock is held */
1972 static void csi_L(struct vc_data *vc, unsigned int nr)
1973 {
1974         if (nr > vc->vc_rows - vc->state.y)
1975                 nr = vc->vc_rows - vc->state.y;
1976         else if (!nr)
1977                 nr = 1;
1978         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, nr);
1979         vc->vc_need_wrap = 0;
1980 }
1981
1982 /* console_lock is held */
1983 static void csi_P(struct vc_data *vc, unsigned int nr)
1984 {
1985         if (nr > vc->vc_cols - vc->state.x)
1986                 nr = vc->vc_cols - vc->state.x;
1987         else if (!nr)
1988                 nr = 1;
1989         delete_char(vc, nr);
1990 }
1991
1992 /* console_lock is held */
1993 static void csi_M(struct vc_data *vc, unsigned int nr)
1994 {
1995         if (nr > vc->vc_rows - vc->state.y)
1996                 nr = vc->vc_rows - vc->state.y;
1997         else if (!nr)
1998                 nr=1;
1999         con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
2000         vc->vc_need_wrap = 0;
2001 }
2002
2003 /* console_lock is held (except via vc_init->reset_terminal */
2004 static void save_cur(struct vc_data *vc)
2005 {
2006         memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
2007 }
2008
2009 /* console_lock is held */
2010 static void restore_cur(struct vc_data *vc)
2011 {
2012         memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
2013
2014         gotoxy(vc, vc->state.x, vc->state.y);
2015         vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
2016                         vc);
2017         update_attr(vc);
2018         vc->vc_need_wrap = 0;
2019 }
2020
2021 enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
2022         EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
2023         ESpalette, ESosc, ESapc, ESpm, ESdcs };
2024
2025 /* console_lock is held (except via vc_init()) */
2026 static void reset_terminal(struct vc_data *vc, int do_clear)
2027 {
2028         unsigned int i;
2029
2030         vc->vc_top              = 0;
2031         vc->vc_bottom           = vc->vc_rows;
2032         vc->vc_state            = ESnormal;
2033         vc->vc_priv             = EPecma;
2034         vc->vc_translate        = set_translate(LAT1_MAP, vc);
2035         vc->state.Gx_charset[0] = LAT1_MAP;
2036         vc->state.Gx_charset[1] = GRAF_MAP;
2037         vc->state.charset       = 0;
2038         vc->vc_need_wrap        = 0;
2039         vc->vc_report_mouse     = 0;
2040         vc->vc_utf              = default_utf8;
2041         vc->vc_utf_count        = 0;
2042
2043         vc->vc_disp_ctrl        = 0;
2044         vc->vc_toggle_meta      = 0;
2045
2046         vc->vc_decscnm          = 0;
2047         vc->vc_decom            = 0;
2048         vc->vc_decawm           = 1;
2049         vc->vc_deccm            = global_cursor_default;
2050         vc->vc_decim            = 0;
2051
2052         vt_reset_keyboard(vc->vc_num);
2053
2054         vc->vc_cursor_type = cur_default;
2055         vc->vc_complement_mask = vc->vc_s_complement_mask;
2056
2057         default_attr(vc);
2058         update_attr(vc);
2059
2060         bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2061         for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
2062                 set_bit(i, vc->vc_tab_stop);
2063
2064         vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
2065         vc->vc_bell_duration = DEFAULT_BELL_DURATION;
2066         vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
2067
2068         gotoxy(vc, 0, 0);
2069         save_cur(vc);
2070         if (do_clear)
2071             csi_J(vc, 2);
2072 }
2073
2074 static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
2075 {
2076         unsigned char *charset = &vc->state.Gx_charset[which];
2077
2078         switch (c) {
2079         case '0':
2080                 *charset = GRAF_MAP;
2081                 break;
2082         case 'B':
2083                 *charset = LAT1_MAP;
2084                 break;
2085         case 'U':
2086                 *charset = IBMPC_MAP;
2087                 break;
2088         case 'K':
2089                 *charset = USER_MAP;
2090                 break;
2091         }
2092
2093         if (vc->state.charset == which)
2094                 vc->vc_translate = set_translate(*charset, vc);
2095 }
2096
2097 /* is this state an ANSI control string? */
2098 static bool ansi_control_string(unsigned int state)
2099 {
2100         if (state == ESosc || state == ESapc || state == ESpm || state == ESdcs)
2101                 return true;
2102         return false;
2103 }
2104
2105 /* console_lock is held */
2106 static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
2107 {
2108         /*
2109          *  Control characters can be used in the _middle_
2110          *  of an escape sequence, aside from ANSI control strings.
2111          */
2112         if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
2113                 return;
2114         switch (c) {
2115         case 0:
2116                 return;
2117         case 7:
2118                 if (ansi_control_string(vc->vc_state))
2119                         vc->vc_state = ESnormal;
2120                 else if (vc->vc_bell_duration)
2121                         kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
2122                 return;
2123         case 8:
2124                 bs(vc);
2125                 return;
2126         case 9:
2127                 vc->vc_pos -= (vc->state.x << 1);
2128
2129                 vc->state.x = find_next_bit(vc->vc_tab_stop,
2130                                 min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
2131                                 vc->state.x + 1);
2132                 if (vc->state.x >= VC_TABSTOPS_COUNT)
2133                         vc->state.x = vc->vc_cols - 1;
2134
2135                 vc->vc_pos += (vc->state.x << 1);
2136                 notify_write(vc, '\t');
2137                 return;
2138         case 10: case 11: case 12:
2139                 lf(vc);
2140                 if (!is_kbd(vc, lnm))
2141                         return;
2142                 fallthrough;
2143         case 13:
2144                 cr(vc);
2145                 return;
2146         case 14:
2147                 vc->state.charset = 1;
2148                 vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
2149                 vc->vc_disp_ctrl = 1;
2150                 return;
2151         case 15:
2152                 vc->state.charset = 0;
2153                 vc->vc_translate = set_translate(vc->state.Gx_charset[0], vc);
2154                 vc->vc_disp_ctrl = 0;
2155                 return;
2156         case 24: case 26:
2157                 vc->vc_state = ESnormal;
2158                 return;
2159         case 27:
2160                 vc->vc_state = ESesc;
2161                 return;
2162         case 127:
2163                 del(vc);
2164                 return;
2165         case 128+27:
2166                 vc->vc_state = ESsquare;
2167                 return;
2168         }
2169         switch(vc->vc_state) {
2170         case ESesc:
2171                 vc->vc_state = ESnormal;
2172                 switch (c) {
2173                 case '[':
2174                         vc->vc_state = ESsquare;
2175                         return;
2176                 case ']':
2177                         vc->vc_state = ESnonstd;
2178                         return;
2179                 case '_':
2180                         vc->vc_state = ESapc;
2181                         return;
2182                 case '^':
2183                         vc->vc_state = ESpm;
2184                         return;
2185                 case '%':
2186                         vc->vc_state = ESpercent;
2187                         return;
2188                 case 'E':
2189                         cr(vc);
2190                         lf(vc);
2191                         return;
2192                 case 'M':
2193                         ri(vc);
2194                         return;
2195                 case 'D':
2196                         lf(vc);
2197                         return;
2198                 case 'H':
2199                         if (vc->state.x < VC_TABSTOPS_COUNT)
2200                                 set_bit(vc->state.x, vc->vc_tab_stop);
2201                         return;
2202                 case 'P':
2203                         vc->vc_state = ESdcs;
2204                         return;
2205                 case 'Z':
2206                         respond_ID(tty);
2207                         return;
2208                 case '7':
2209                         save_cur(vc);
2210                         return;
2211                 case '8':
2212                         restore_cur(vc);
2213                         return;
2214                 case '(':
2215                         vc->vc_state = ESsetG0;
2216                         return;
2217                 case ')':
2218                         vc->vc_state = ESsetG1;
2219                         return;
2220                 case '#':
2221                         vc->vc_state = EShash;
2222                         return;
2223                 case 'c':
2224                         reset_terminal(vc, 1);
2225                         return;
2226                 case '>':  /* Numeric keypad */
2227                         clr_kbd(vc, kbdapplic);
2228                         return;
2229                 case '=':  /* Appl. keypad */
2230                         set_kbd(vc, kbdapplic);
2231                         return;
2232                 }
2233                 return;
2234         case ESnonstd:
2235                 if (c=='P') {   /* palette escape sequence */
2236                         for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2237                                 vc->vc_par[vc->vc_npar] = 0;
2238                         vc->vc_npar = 0;
2239                         vc->vc_state = ESpalette;
2240                         return;
2241                 } else if (c=='R') {   /* reset palette */
2242                         reset_palette(vc);
2243                         vc->vc_state = ESnormal;
2244                 } else if (c>='0' && c<='9')
2245                         vc->vc_state = ESosc;
2246                 else
2247                         vc->vc_state = ESnormal;
2248                 return;
2249         case ESpalette:
2250                 if (isxdigit(c)) {
2251                         vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
2252                         if (vc->vc_npar == 7) {
2253                                 int i = vc->vc_par[0] * 3, j = 1;
2254                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2255                                 vc->vc_palette[i++] += vc->vc_par[j++];
2256                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2257                                 vc->vc_palette[i++] += vc->vc_par[j++];
2258                                 vc->vc_palette[i] = 16 * vc->vc_par[j++];
2259                                 vc->vc_palette[i] += vc->vc_par[j];
2260                                 set_palette(vc);
2261                                 vc->vc_state = ESnormal;
2262                         }
2263                 } else
2264                         vc->vc_state = ESnormal;
2265                 return;
2266         case ESsquare:
2267                 for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
2268                         vc->vc_par[vc->vc_npar] = 0;
2269                 vc->vc_npar = 0;
2270                 vc->vc_state = ESgetpars;
2271                 if (c == '[') { /* Function key */
2272                         vc->vc_state=ESfunckey;
2273                         return;
2274                 }
2275                 switch (c) {
2276                 case '?':
2277                         vc->vc_priv = EPdec;
2278                         return;
2279                 case '>':
2280                         vc->vc_priv = EPgt;
2281                         return;
2282                 case '=':
2283                         vc->vc_priv = EPeq;
2284                         return;
2285                 case '<':
2286                         vc->vc_priv = EPlt;
2287                         return;
2288                 }
2289                 vc->vc_priv = EPecma;
2290                 fallthrough;
2291         case ESgetpars:
2292                 if (c == ';' && vc->vc_npar < NPAR - 1) {
2293                         vc->vc_npar++;
2294                         return;
2295                 } else if (c>='0' && c<='9') {
2296                         vc->vc_par[vc->vc_npar] *= 10;
2297                         vc->vc_par[vc->vc_npar] += c - '0';
2298                         return;
2299                 }
2300                 if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
2301                         vc->vc_state = EScsiignore;
2302                         return;
2303                 }
2304                 vc->vc_state = ESnormal;
2305                 switch(c) {
2306                 case 'h':
2307                         if (vc->vc_priv <= EPdec)
2308                                 set_mode(vc, 1);
2309                         return;
2310                 case 'l':
2311                         if (vc->vc_priv <= EPdec)
2312                                 set_mode(vc, 0);
2313                         return;
2314                 case 'c':
2315                         if (vc->vc_priv == EPdec) {
2316                                 if (vc->vc_par[0])
2317                                         vc->vc_cursor_type =
2318                                                 CUR_MAKE(vc->vc_par[0],
2319                                                          vc->vc_par[1],
2320                                                          vc->vc_par[2]);
2321                                 else
2322                                         vc->vc_cursor_type = cur_default;
2323                                 return;
2324                         }
2325                         break;
2326                 case 'm':
2327                         if (vc->vc_priv == EPdec) {
2328                                 clear_selection();
2329                                 if (vc->vc_par[0])
2330                                         vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
2331                                 else
2332                                         vc->vc_complement_mask = vc->vc_s_complement_mask;
2333                                 return;
2334                         }
2335                         break;
2336                 case 'n':
2337                         if (vc->vc_priv == EPecma) {
2338                                 if (vc->vc_par[0] == 5)
2339                                         status_report(tty);
2340                                 else if (vc->vc_par[0] == 6)
2341                                         cursor_report(vc, tty);
2342                         }
2343                         return;
2344                 }
2345                 if (vc->vc_priv != EPecma) {
2346                         vc->vc_priv = EPecma;
2347                         return;
2348                 }
2349                 switch(c) {
2350                 case 'G': case '`':
2351                         if (vc->vc_par[0])
2352                                 vc->vc_par[0]--;
2353                         gotoxy(vc, vc->vc_par[0], vc->state.y);
2354                         return;
2355                 case 'A':
2356                         if (!vc->vc_par[0])
2357                                 vc->vc_par[0]++;
2358                         gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
2359                         return;
2360                 case 'B': case 'e':
2361                         if (!vc->vc_par[0])
2362                                 vc->vc_par[0]++;
2363                         gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
2364                         return;
2365                 case 'C': case 'a':
2366                         if (!vc->vc_par[0])
2367                                 vc->vc_par[0]++;
2368                         gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
2369                         return;
2370                 case 'D':
2371                         if (!vc->vc_par[0])
2372                                 vc->vc_par[0]++;
2373                         gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
2374                         return;
2375                 case 'E':
2376                         if (!vc->vc_par[0])
2377                                 vc->vc_par[0]++;
2378                         gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
2379                         return;
2380                 case 'F':
2381                         if (!vc->vc_par[0])
2382                                 vc->vc_par[0]++;
2383                         gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
2384                         return;
2385                 case 'd':
2386                         if (vc->vc_par[0])
2387                                 vc->vc_par[0]--;
2388                         gotoxay(vc, vc->state.x ,vc->vc_par[0]);
2389                         return;
2390                 case 'H': case 'f':
2391                         if (vc->vc_par[0])
2392                                 vc->vc_par[0]--;
2393                         if (vc->vc_par[1])
2394                                 vc->vc_par[1]--;
2395                         gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
2396                         return;
2397                 case 'J':
2398                         csi_J(vc, vc->vc_par[0]);
2399                         return;
2400                 case 'K':
2401                         csi_K(vc, vc->vc_par[0]);
2402                         return;
2403                 case 'L':
2404                         csi_L(vc, vc->vc_par[0]);
2405                         return;
2406                 case 'M':
2407                         csi_M(vc, vc->vc_par[0]);
2408                         return;
2409                 case 'P':
2410                         csi_P(vc, vc->vc_par[0]);
2411                         return;
2412                 case 'c':
2413                         if (!vc->vc_par[0])
2414                                 respond_ID(tty);
2415                         return;
2416                 case 'g':
2417                         if (!vc->vc_par[0] && vc->state.x < VC_TABSTOPS_COUNT)
2418                                 set_bit(vc->state.x, vc->vc_tab_stop);
2419                         else if (vc->vc_par[0] == 3)
2420                                 bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
2421                         return;
2422                 case 'm':
2423                         csi_m(vc);
2424                         return;
2425                 case 'q': /* DECLL - but only 3 leds */
2426                         /* map 0,1,2,3 to 0,1,2,4 */
2427                         if (vc->vc_par[0] < 4)
2428                                 vt_set_led_state(vc->vc_num,
2429                                             (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
2430                         return;
2431                 case 'r':
2432                         if (!vc->vc_par[0])
2433                                 vc->vc_par[0]++;
2434                         if (!vc->vc_par[1])
2435                                 vc->vc_par[1] = vc->vc_rows;
2436                         /* Minimum allowed region is 2 lines */
2437                         if (vc->vc_par[0] < vc->vc_par[1] &&
2438                             vc->vc_par[1] <= vc->vc_rows) {
2439                                 vc->vc_top = vc->vc_par[0] - 1;
2440                                 vc->vc_bottom = vc->vc_par[1];
2441                                 gotoxay(vc, 0, 0);
2442                         }
2443                         return;
2444                 case 's':
2445                         save_cur(vc);
2446                         return;
2447                 case 'u':
2448                         restore_cur(vc);
2449                         return;
2450                 case 'X':
2451                         csi_X(vc, vc->vc_par[0]);
2452                         return;
2453                 case '@':
2454                         csi_at(vc, vc->vc_par[0]);
2455                         return;
2456                 case ']': /* setterm functions */
2457                         setterm_command(vc);
2458                         return;
2459                 }
2460                 return;
2461         case EScsiignore:
2462                 if (c >= 20 && c <= 0x3f)
2463                         return;
2464                 vc->vc_state = ESnormal;
2465                 return;
2466         case ESpercent:
2467                 vc->vc_state = ESnormal;
2468                 switch (c) {
2469                 case '@':  /* defined in ISO 2022 */
2470                         vc->vc_utf = 0;
2471                         return;
2472                 case 'G':  /* prelim official escape code */
2473                 case '8':  /* retained for compatibility */
2474                         vc->vc_utf = 1;
2475                         return;
2476                 }
2477                 return;
2478         case ESfunckey:
2479                 vc->vc_state = ESnormal;
2480                 return;
2481         case EShash:
2482                 vc->vc_state = ESnormal;
2483                 if (c == '8') {
2484                         /* DEC screen alignment test. kludge :-) */
2485                         vc->vc_video_erase_char =
2486                                 (vc->vc_video_erase_char & 0xff00) | 'E';
2487                         csi_J(vc, 2);
2488                         vc->vc_video_erase_char =
2489                                 (vc->vc_video_erase_char & 0xff00) | ' ';
2490                         do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
2491                 }
2492                 return;
2493         case ESsetG0:
2494                 vc_setGx(vc, 0, c);
2495                 vc->vc_state = ESnormal;
2496                 return;
2497         case ESsetG1:
2498                 vc_setGx(vc, 1, c);
2499                 vc->vc_state = ESnormal;
2500                 return;
2501         case ESapc:
2502                 return;
2503         case ESosc:
2504                 return;
2505         case ESpm:
2506                 return;
2507         case ESdcs:
2508                 return;
2509         default:
2510                 vc->vc_state = ESnormal;
2511         }
2512 }
2513
2514 /* is_double_width() is based on the wcwidth() implementation by
2515  * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
2516  * Latest version: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
2517  */
2518 struct interval {
2519         uint32_t first;
2520         uint32_t last;
2521 };
2522
2523 static int ucs_cmp(const void *key, const void *elt)
2524 {
2525         uint32_t ucs = *(uint32_t *)key;
2526         struct interval e = *(struct interval *) elt;
2527
2528         if (ucs > e.last)
2529                 return 1;
2530         else if (ucs < e.first)
2531                 return -1;
2532         return 0;
2533 }
2534
2535 static int is_double_width(uint32_t ucs)
2536 {
2537         static const struct interval double_width[] = {
2538                 { 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
2539                 { 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
2540                 { 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
2541                 { 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
2542         };
2543         if (ucs < double_width[0].first ||
2544             ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
2545                 return 0;
2546
2547         return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
2548                         sizeof(struct interval), ucs_cmp) != NULL;
2549 }
2550
2551 struct vc_draw_region {
2552         unsigned long from, to;
2553         int x;
2554 };
2555
2556 static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
2557 {
2558         if (draw->x < 0)
2559                 return;
2560
2561         vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
2562                         (u16 *)draw->to - (u16 *)draw->from, vc->state.y,
2563                         draw->x);
2564         draw->x = -1;
2565 }
2566
2567 static inline int vc_translate_ascii(const struct vc_data *vc, int c)
2568 {
2569         if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
2570                 if (vc->vc_toggle_meta)
2571                         c |= 0x80;
2572
2573                 return vc->vc_translate[c];
2574         }
2575
2576         return c;
2577 }
2578
2579
2580 /**
2581  * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
2582  * @c: the received character, or U+FFFD for invalid sequences.
2583  */
2584 static inline int vc_sanitize_unicode(const int c)
2585 {
2586         if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
2587                 return 0xfffd;
2588
2589         return c;
2590 }
2591
2592 /**
2593  * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
2594  * @vc: virtual console
2595  * @c: character to translate
2596  * @rescan: we return true if we need more (continuation) data
2597  *
2598  * @vc_utf_char is the being-constructed unicode character.
2599  * @vc_utf_count is the number of continuation bytes still expected to arrive.
2600  * @vc_npar is the number of continuation bytes arrived so far.
2601  */
2602 static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
2603 {
2604         static const u32 utf8_length_changes[] = {
2605                 0x0000007f, 0x000007ff, 0x0000ffff,
2606                 0x001fffff, 0x03ffffff, 0x7fffffff
2607         };
2608
2609         /* Continuation byte received */
2610         if ((c & 0xc0) == 0x80) {
2611                 /* Unexpected continuation byte? */
2612                 if (!vc->vc_utf_count)
2613                         return 0xfffd;
2614
2615                 vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
2616                 vc->vc_npar++;
2617                 if (--vc->vc_utf_count)
2618                         goto need_more_bytes;
2619
2620                 /* Got a whole character */
2621                 c = vc->vc_utf_char;
2622                 /* Reject overlong sequences */
2623                 if (c <= utf8_length_changes[vc->vc_npar - 1] ||
2624                                 c > utf8_length_changes[vc->vc_npar])
2625                         return 0xfffd;
2626
2627                 return vc_sanitize_unicode(c);
2628         }
2629
2630         /* Single ASCII byte or first byte of a sequence received */
2631         if (vc->vc_utf_count) {
2632                 /* Continuation byte expected */
2633                 *rescan = true;
2634                 vc->vc_utf_count = 0;
2635                 return 0xfffd;
2636         }
2637
2638         /* Nothing to do if an ASCII byte was received */
2639         if (c <= 0x7f)
2640                 return c;
2641
2642         /* First byte of a multibyte sequence received */
2643         vc->vc_npar = 0;
2644         if ((c & 0xe0) == 0xc0) {
2645                 vc->vc_utf_count = 1;
2646                 vc->vc_utf_char = (c & 0x1f);
2647         } else if ((c & 0xf0) == 0xe0) {
2648                 vc->vc_utf_count = 2;
2649                 vc->vc_utf_char = (c & 0x0f);
2650         } else if ((c & 0xf8) == 0xf0) {
2651                 vc->vc_utf_count = 3;
2652                 vc->vc_utf_char = (c & 0x07);
2653         } else if ((c & 0xfc) == 0xf8) {
2654                 vc->vc_utf_count = 4;
2655                 vc->vc_utf_char = (c & 0x03);
2656         } else if ((c & 0xfe) == 0xfc) {
2657                 vc->vc_utf_count = 5;
2658                 vc->vc_utf_char = (c & 0x01);
2659         } else {
2660                 /* 254 and 255 are invalid */
2661                 return 0xfffd;
2662         }
2663
2664 need_more_bytes:
2665         return -1;
2666 }
2667
2668 static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
2669 {
2670         /* Do no translation at all in control states */
2671         if (vc->vc_state != ESnormal)
2672                 return *c;
2673
2674         if (vc->vc_utf && !vc->vc_disp_ctrl)
2675                 return *c = vc_translate_unicode(vc, *c, rescan);
2676
2677         /* no utf or alternate charset mode */
2678         return vc_translate_ascii(vc, *c);
2679 }
2680
2681 static inline unsigned char vc_invert_attr(const struct vc_data *vc)
2682 {
2683         if (!vc->vc_can_do_color)
2684                 return vc->vc_attr ^ 0x08;
2685
2686         if (vc->vc_hi_font_mask == 0x100)
2687                 return   (vc->vc_attr & 0x11) |
2688                         ((vc->vc_attr & 0xe0) >> 4) |
2689                         ((vc->vc_attr & 0x0e) << 4);
2690
2691         return   (vc->vc_attr & 0x88) |
2692                 ((vc->vc_attr & 0x70) >> 4) |
2693                 ((vc->vc_attr & 0x07) << 4);
2694 }
2695
2696 static bool vc_is_control(struct vc_data *vc, int tc, int c)
2697 {
2698         /*
2699          * A bitmap for codes <32. A bit of 1 indicates that the code
2700          * corresponding to that bit number invokes some special action (such
2701          * as cursor movement) and should not be displayed as a glyph unless
2702          * the disp_ctrl mode is explicitly enabled.
2703          */
2704         static const u32 CTRL_ACTION = 0x0d00ff81;
2705         /* Cannot be overridden by disp_ctrl */
2706         static const u32 CTRL_ALWAYS = 0x0800f501;
2707
2708         if (vc->vc_state != ESnormal)
2709                 return true;
2710
2711         if (!tc)
2712                 return true;
2713
2714         /*
2715          * If the original code was a control character we only allow a glyph
2716          * to be displayed if the code is not normally used (such as for cursor
2717          * movement) or if the disp_ctrl mode has been explicitly enabled.
2718          * Certain characters (as given by the CTRL_ALWAYS bitmap) are always
2719          * displayed as control characters, as the console would be pretty
2720          * useless without them; to display an arbitrary font position use the
2721          * direct-to-font zone in UTF-8 mode.
2722          */
2723         if (c < 32) {
2724                 if (vc->vc_disp_ctrl)
2725                         return CTRL_ALWAYS & BIT(c);
2726                 else
2727                         return vc->vc_utf || (CTRL_ACTION & BIT(c));
2728         }
2729
2730         if (c == 127 && !vc->vc_disp_ctrl)
2731                 return true;
2732
2733         if (c == 128 + 27)
2734                 return true;
2735
2736         return false;
2737 }
2738
2739 static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
2740                 struct vc_draw_region *draw)
2741 {
2742         int next_c;
2743         unsigned char vc_attr = vc->vc_attr;
2744         u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
2745         u8 width = 1;
2746         bool inverse = false;
2747
2748         if (vc->vc_utf && !vc->vc_disp_ctrl) {
2749                 if (is_double_width(c))
2750                         width = 2;
2751         }
2752
2753         /* Now try to find out how to display it */
2754         tc = conv_uni_to_pc(vc, tc);
2755         if (tc & ~charmask) {
2756                 if (tc == -1 || tc == -2)
2757                         return -1; /* nothing to display */
2758
2759                 /* Glyph not found */
2760                 if ((!vc->vc_utf || vc->vc_disp_ctrl || c < 128) &&
2761                                 !(c & ~charmask)) {
2762                         /*
2763                          * In legacy mode use the glyph we get by a 1:1
2764                          * mapping.
2765                          * This would make absolutely no sense with Unicode in
2766                          * mind, but do this for ASCII characters since a font
2767                          * may lack Unicode mapping info and we don't want to
2768                          * end up with having question marks only.
2769                          */
2770                         tc = c;
2771                 } else {
2772                         /*
2773                          * Display U+FFFD. If it's not found, display an inverse
2774                          * question mark.
2775                          */
2776                         tc = conv_uni_to_pc(vc, 0xfffd);
2777                         if (tc < 0) {
2778                                 inverse = true;
2779                                 tc = conv_uni_to_pc(vc, '?');
2780                                 if (tc < 0)
2781                                         tc = '?';
2782
2783                                 vc_attr = vc_invert_attr(vc);
2784                                 con_flush(vc, draw);
2785                         }
2786                 }
2787         }
2788
2789         next_c = c;
2790         while (1) {
2791                 if (vc->vc_need_wrap || vc->vc_decim)
2792                         con_flush(vc, draw);
2793                 if (vc->vc_need_wrap) {
2794                         cr(vc);
2795                         lf(vc);
2796                 }
2797                 if (vc->vc_decim)
2798                         insert_char(vc, 1);
2799                 vc_uniscr_putc(vc, next_c);
2800
2801                 if (himask)
2802                         tc = ((tc & 0x100) ? himask : 0) |
2803                               (tc &  0xff);
2804                 tc |= (vc_attr << 8) & ~himask;
2805
2806                 scr_writew(tc, (u16 *)vc->vc_pos);
2807
2808                 if (con_should_update(vc) && draw->x < 0) {
2809                         draw->x = vc->state.x;
2810                         draw->from = vc->vc_pos;
2811                 }
2812                 if (vc->state.x == vc->vc_cols - 1) {
2813                         vc->vc_need_wrap = vc->vc_decawm;
2814                         draw->to = vc->vc_pos + 2;
2815                 } else {
2816                         vc->state.x++;
2817                         draw->to = (vc->vc_pos += 2);
2818                 }
2819
2820                 if (!--width)
2821                         break;
2822
2823                 /* A space is printed in the second column */
2824                 tc = conv_uni_to_pc(vc, ' ');
2825                 if (tc < 0)
2826                         tc = ' ';
2827                 next_c = ' ';
2828         }
2829         notify_write(vc, c);
2830
2831         if (inverse)
2832                 con_flush(vc, draw);
2833
2834         return 0;
2835 }
2836
2837 /* acquires console_lock */
2838 static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
2839 {
2840         struct vc_draw_region draw = {
2841                 .x = -1,
2842         };
2843         int c, tc, n = 0;
2844         unsigned int currcons;
2845         struct vc_data *vc;
2846         struct vt_notifier_param param;
2847         bool rescan;
2848
2849         if (in_interrupt())
2850                 return count;
2851
2852         console_lock();
2853         vc = tty->driver_data;
2854         if (vc == NULL) {
2855                 pr_err("vt: argh, driver_data is NULL !\n");
2856                 console_unlock();
2857                 return 0;
2858         }
2859
2860         currcons = vc->vc_num;
2861         if (!vc_cons_allocated(currcons)) {
2862                 /* could this happen? */
2863                 pr_warn_once("con_write: tty %d not allocated\n", currcons+1);
2864                 console_unlock();
2865                 return 0;
2866         }
2867
2868
2869         /* undraw cursor first */
2870         if (con_is_fg(vc))
2871                 hide_cursor(vc);
2872
2873         param.vc = vc;
2874
2875         while (!tty->flow.stopped && count) {
2876                 int orig = *buf;
2877                 buf++;
2878                 n++;
2879                 count--;
2880 rescan_last_byte:
2881                 c = orig;
2882                 rescan = false;
2883
2884                 tc = vc_translate(vc, &c, &rescan);
2885                 if (tc == -1)
2886                         continue;
2887
2888                 param.c = tc;
2889                 if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
2890                                         &param) == NOTIFY_STOP)
2891                         continue;
2892
2893                 if (vc_is_control(vc, tc, c)) {
2894                         con_flush(vc, &draw);
2895                         do_con_trol(tty, vc, orig);
2896                         continue;
2897                 }
2898
2899                 if (vc_con_write_normal(vc, tc, c, &draw) < 0)
2900                         continue;
2901
2902                 if (rescan)
2903                         goto rescan_last_byte;
2904         }
2905         con_flush(vc, &draw);
2906         console_conditional_schedule();
2907         notify_update(vc);
2908         console_unlock();
2909         return n;
2910 }
2911
2912 /*
2913  * This is the console switching callback.
2914  *
2915  * Doing console switching in a process context allows
2916  * us to do the switches asynchronously (needed when we want
2917  * to switch due to a keyboard interrupt).  Synchronization
2918  * with other console code and prevention of re-entrancy is
2919  * ensured with console_lock.
2920  */
2921 static void console_callback(struct work_struct *ignored)
2922 {
2923         console_lock();
2924
2925         if (want_console >= 0) {
2926                 if (want_console != fg_console &&
2927                     vc_cons_allocated(want_console)) {
2928                         hide_cursor(vc_cons[fg_console].d);
2929                         change_console(vc_cons[want_console].d);
2930                         /* we only changed when the console had already
2931                            been allocated - a new console is not created
2932                            in an interrupt routine */
2933                 }
2934                 want_console = -1;
2935         }
2936         if (do_poke_blanked_console) { /* do not unblank for a LED change */
2937                 do_poke_blanked_console = 0;
2938                 poke_blanked_console();
2939         }
2940         if (scrollback_delta) {
2941                 struct vc_data *vc = vc_cons[fg_console].d;
2942                 clear_selection();
2943                 if (vc->vc_mode == KD_TEXT && vc->vc_sw->con_scrolldelta)
2944                         vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
2945                 scrollback_delta = 0;
2946         }
2947         if (blank_timer_expired) {
2948                 do_blank_screen(0);
2949                 blank_timer_expired = 0;
2950         }
2951         notify_update(vc_cons[fg_console].d);
2952
2953         console_unlock();
2954 }
2955
2956 int set_console(int nr)
2957 {
2958         struct vc_data *vc = vc_cons[fg_console].d;
2959
2960         if (!vc_cons_allocated(nr) || vt_dont_switch ||
2961                 (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
2962
2963                 /*
2964                  * Console switch will fail in console_callback() or
2965                  * change_console() so there is no point scheduling
2966                  * the callback
2967                  *
2968                  * Existing set_console() users don't check the return
2969                  * value so this shouldn't break anything
2970                  */
2971                 return -EINVAL;
2972         }
2973
2974         want_console = nr;
2975         schedule_console_callback();
2976
2977         return 0;
2978 }
2979
2980 struct tty_driver *console_driver;
2981
2982 #ifdef CONFIG_VT_CONSOLE
2983
2984 /**
2985  * vt_kmsg_redirect() - Sets/gets the kernel message console
2986  * @new:        The new virtual terminal number or -1 if the console should stay
2987  *              unchanged
2988  *
2989  * By default, the kernel messages are always printed on the current virtual
2990  * console. However, the user may modify that default with the
2991  * TIOCL_SETKMSGREDIRECT ioctl call.
2992  *
2993  * This function sets the kernel message console to be @new. It returns the old
2994  * virtual console number. The virtual terminal number 0 (both as parameter and
2995  * return value) means no redirection (i.e. always printed on the currently
2996  * active console).
2997  *
2998  * The parameter -1 means that only the current console is returned, but the
2999  * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
3000  * case to make the code more understandable.
3001  *
3002  * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
3003  * the parameter and always returns 0.
3004  */
3005 int vt_kmsg_redirect(int new)
3006 {
3007         static int kmsg_con;
3008
3009         if (new != -1)
3010                 return xchg(&kmsg_con, new);
3011         else
3012                 return kmsg_con;
3013 }
3014
3015 /*
3016  *      Console on virtual terminal
3017  *
3018  * The console must be locked when we get here.
3019  */
3020
3021 static void vt_console_print(struct console *co, const char *b, unsigned count)
3022 {
3023         struct vc_data *vc = vc_cons[fg_console].d;
3024         unsigned char c;
3025         static DEFINE_SPINLOCK(printing_lock);
3026         const ushort *start;
3027         ushort start_x, cnt;
3028         int kmsg_console;
3029
3030         WARN_CONSOLE_UNLOCKED();
3031
3032         /* this protects against concurrent oops only */
3033         if (!spin_trylock(&printing_lock))
3034                 return;
3035
3036         kmsg_console = vt_get_kmsg_redirect();
3037         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
3038                 vc = vc_cons[kmsg_console - 1].d;
3039
3040         if (!vc_cons_allocated(fg_console)) {
3041                 /* impossible */
3042                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
3043                 goto quit;
3044         }
3045
3046         if (vc->vc_mode != KD_TEXT)
3047                 goto quit;
3048
3049         /* undraw cursor first */
3050         if (con_is_fg(vc))
3051                 hide_cursor(vc);
3052
3053         start = (ushort *)vc->vc_pos;
3054         start_x = vc->state.x;
3055         cnt = 0;
3056         while (count--) {
3057                 c = *b++;
3058                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
3059                         if (cnt && con_is_visible(vc))
3060                                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3061                         cnt = 0;
3062                         if (c == 8) {           /* backspace */
3063                                 bs(vc);
3064                                 start = (ushort *)vc->vc_pos;
3065                                 start_x = vc->state.x;
3066                                 continue;
3067                         }
3068                         if (c != 13)
3069                                 lf(vc);
3070                         cr(vc);
3071                         start = (ushort *)vc->vc_pos;
3072                         start_x = vc->state.x;
3073                         if (c == 10 || c == 13)
3074                                 continue;
3075                 }
3076                 vc_uniscr_putc(vc, c);
3077                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
3078                 notify_write(vc, c);
3079                 cnt++;
3080                 if (vc->state.x == vc->vc_cols - 1) {
3081                         vc->vc_need_wrap = 1;
3082                 } else {
3083                         vc->vc_pos += 2;
3084                         vc->state.x++;
3085                 }
3086         }
3087         if (cnt && con_is_visible(vc))
3088                 vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
3089         set_cursor(vc);
3090         notify_update(vc);
3091
3092 quit:
3093         spin_unlock(&printing_lock);
3094 }
3095
3096 static struct tty_driver *vt_console_device(struct console *c, int *index)
3097 {
3098         *index = c->index ? c->index-1 : fg_console;
3099         return console_driver;
3100 }
3101
3102 static int vt_console_setup(struct console *co, char *options)
3103 {
3104         return co->index >= MAX_NR_CONSOLES ? -EINVAL : 0;
3105 }
3106
3107 static struct console vt_console_driver = {
3108         .name           = "tty",
3109         .setup          = vt_console_setup,
3110         .write          = vt_console_print,
3111         .device         = vt_console_device,
3112         .unblank        = unblank_screen,
3113         .flags          = CON_PRINTBUFFER,
3114         .index          = -1,
3115 };
3116 #endif
3117
3118 /*
3119  *      Handling of Linux-specific VC ioctls
3120  */
3121
3122 /*
3123  * Generally a bit racy with respect to console_lock();.
3124  *
3125  * There are some functions which don't need it.
3126  *
3127  * There are some functions which can sleep for arbitrary periods
3128  * (paste_selection) but we don't need the lock there anyway.
3129  *
3130  * set_selection_user has locking, and definitely needs it
3131  */
3132
3133 int tioclinux(struct tty_struct *tty, unsigned long arg)
3134 {
3135         char type, data;
3136         char __user *p = (char __user *)arg;
3137         int lines;
3138         int ret;
3139
3140         if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
3141                 return -EPERM;
3142         if (get_user(type, p))
3143                 return -EFAULT;
3144         ret = 0;
3145
3146         switch (type)
3147         {
3148                 case TIOCL_SETSEL:
3149                         ret = set_selection_user((struct tiocl_selection
3150                                                  __user *)(p+1), tty);
3151                         break;
3152                 case TIOCL_PASTESEL:
3153                         ret = paste_selection(tty);
3154                         break;
3155                 case TIOCL_UNBLANKSCREEN:
3156                         console_lock();
3157                         unblank_screen();
3158                         console_unlock();
3159                         break;
3160                 case TIOCL_SELLOADLUT:
3161                         console_lock();
3162                         ret = sel_loadlut(p);
3163                         console_unlock();
3164                         break;
3165                 case TIOCL_GETSHIFTSTATE:
3166
3167         /*
3168          * Make it possible to react to Shift+Mousebutton.
3169          * Note that 'shift_state' is an undocumented
3170          * kernel-internal variable; programs not closely
3171          * related to the kernel should not use this.
3172          */
3173                         data = vt_get_shift_state();
3174                         ret = put_user(data, p);
3175                         break;
3176                 case TIOCL_GETMOUSEREPORTING:
3177                         console_lock(); /* May be overkill */
3178                         data = mouse_reporting();
3179                         console_unlock();
3180                         ret = put_user(data, p);
3181                         break;
3182                 case TIOCL_SETVESABLANK:
3183                         console_lock();
3184                         ret = set_vesa_blanking(p);
3185                         console_unlock();
3186                         break;
3187                 case TIOCL_GETKMSGREDIRECT:
3188                         data = vt_get_kmsg_redirect();
3189                         ret = put_user(data, p);
3190                         break;
3191                 case TIOCL_SETKMSGREDIRECT:
3192                         if (!capable(CAP_SYS_ADMIN)) {
3193                                 ret = -EPERM;
3194                         } else {
3195                                 if (get_user(data, p+1))
3196                                         ret = -EFAULT;
3197                                 else
3198                                         vt_kmsg_redirect(data);
3199                         }
3200                         break;
3201                 case TIOCL_GETFGCONSOLE:
3202                         /* No locking needed as this is a transiently
3203                            correct return anyway if the caller hasn't
3204                            disabled switching */
3205                         ret = fg_console;
3206                         break;
3207                 case TIOCL_SCROLLCONSOLE:
3208                         if (get_user(lines, (s32 __user *)(p+4))) {
3209                                 ret = -EFAULT;
3210                         } else {
3211                                 /* Need the console lock here. Note that lots
3212                                    of other calls need fixing before the lock
3213                                    is actually useful ! */
3214                                 console_lock();
3215                                 scrollfront(vc_cons[fg_console].d, lines);
3216                                 console_unlock();
3217                                 ret = 0;
3218                         }
3219                         break;
3220                 case TIOCL_BLANKSCREEN: /* until explicitly unblanked, not only poked */
3221                         console_lock();
3222                         ignore_poke = 1;
3223                         do_blank_screen(0);
3224                         console_unlock();
3225                         break;
3226                 case TIOCL_BLANKEDSCREEN:
3227                         ret = console_blanked;
3228                         break;
3229                 default:
3230                         ret = -EINVAL;
3231                         break;
3232         }
3233         return ret;
3234 }
3235
3236 /*
3237  * /dev/ttyN handling
3238  */
3239
3240 static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
3241 {
3242         int     retval;
3243
3244         retval = do_con_write(tty, buf, count);
3245         con_flush_chars(tty);
3246
3247         return retval;
3248 }
3249
3250 static int con_put_char(struct tty_struct *tty, unsigned char ch)
3251 {
3252         return do_con_write(tty, &ch, 1);
3253 }
3254
3255 static unsigned int con_write_room(struct tty_struct *tty)
3256 {
3257         if (tty->flow.stopped)
3258                 return 0;
3259         return 32768;           /* No limit, really; we're not buffering */
3260 }
3261
3262 /*
3263  * con_throttle and con_unthrottle are only used for
3264  * paste_selection(), which has to stuff in a large number of
3265  * characters...
3266  */
3267 static void con_throttle(struct tty_struct *tty)
3268 {
3269 }
3270
3271 static void con_unthrottle(struct tty_struct *tty)
3272 {
3273         struct vc_data *vc = tty->driver_data;
3274
3275         wake_up_interruptible(&vc->paste_wait);
3276 }
3277
3278 /*
3279  * Turn the Scroll-Lock LED on when the tty is stopped
3280  */
3281 static void con_stop(struct tty_struct *tty)
3282 {
3283         int console_num;
3284         if (!tty)
3285                 return;
3286         console_num = tty->index;
3287         if (!vc_cons_allocated(console_num))
3288                 return;
3289         vt_kbd_con_stop(console_num);
3290 }
3291
3292 /*
3293  * Turn the Scroll-Lock LED off when the console is started
3294  */
3295 static void con_start(struct tty_struct *tty)
3296 {
3297         int console_num;
3298         if (!tty)
3299                 return;
3300         console_num = tty->index;
3301         if (!vc_cons_allocated(console_num))
3302                 return;
3303         vt_kbd_con_start(console_num);
3304 }
3305
3306 static void con_flush_chars(struct tty_struct *tty)
3307 {
3308         struct vc_data *vc;
3309
3310         if (in_interrupt())     /* from flush_to_ldisc */
3311                 return;
3312
3313         /* if we race with con_close(), vt may be null */
3314         console_lock();
3315         vc = tty->driver_data;
3316         if (vc)
3317                 set_cursor(vc);
3318         console_unlock();
3319 }
3320
3321 /*
3322  * Allocate the console screen memory.
3323  */
3324 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
3325 {
3326         unsigned int currcons = tty->index;
3327         struct vc_data *vc;
3328         int ret;
3329
3330         console_lock();
3331         ret = vc_allocate(currcons);
3332         if (ret)
3333                 goto unlock;
3334
3335         vc = vc_cons[currcons].d;
3336
3337         /* Still being freed */
3338         if (vc->port.tty) {
3339                 ret = -ERESTARTSYS;
3340                 goto unlock;
3341         }
3342
3343         ret = tty_port_install(&vc->port, driver, tty);
3344         if (ret)
3345                 goto unlock;
3346
3347         tty->driver_data = vc;
3348         vc->port.tty = tty;
3349         tty_port_get(&vc->port);
3350
3351         if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
3352                 tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
3353                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
3354         }
3355         if (vc->vc_utf)
3356                 tty->termios.c_iflag |= IUTF8;
3357         else
3358                 tty->termios.c_iflag &= ~IUTF8;
3359 unlock:
3360         console_unlock();
3361         return ret;
3362 }
3363
3364 static int con_open(struct tty_struct *tty, struct file *filp)
3365 {
3366         /* everything done in install */
3367         return 0;
3368 }
3369
3370
3371 static void con_close(struct tty_struct *tty, struct file *filp)
3372 {
3373         /* Nothing to do - we defer to shutdown */
3374 }
3375
3376 static void con_shutdown(struct tty_struct *tty)
3377 {
3378         struct vc_data *vc = tty->driver_data;
3379         BUG_ON(vc == NULL);
3380         console_lock();
3381         vc->port.tty = NULL;
3382         console_unlock();
3383 }
3384
3385 static void con_cleanup(struct tty_struct *tty)
3386 {
3387         struct vc_data *vc = tty->driver_data;
3388
3389         tty_port_put(&vc->port);
3390 }
3391
3392 static int default_color           = 7; /* white */
3393 static int default_italic_color    = 2; // green (ASCII)
3394 static int default_underline_color = 3; // cyan (ASCII)
3395 module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
3396 module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
3397 module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
3398
3399 static void vc_init(struct vc_data *vc, unsigned int rows,
3400                     unsigned int cols, int do_clear)
3401 {
3402         int j, k ;
3403
3404         vc->vc_cols = cols;
3405         vc->vc_rows = rows;
3406         vc->vc_size_row = cols << 1;
3407         vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
3408
3409         set_origin(vc);
3410         vc->vc_pos = vc->vc_origin;
3411         reset_vc(vc);
3412         for (j=k=0; j<16; j++) {
3413                 vc->vc_palette[k++] = default_red[j] ;
3414                 vc->vc_palette[k++] = default_grn[j] ;
3415                 vc->vc_palette[k++] = default_blu[j] ;
3416         }
3417         vc->vc_def_color       = default_color;
3418         vc->vc_ulcolor         = default_underline_color;
3419         vc->vc_itcolor         = default_italic_color;
3420         vc->vc_halfcolor       = 0x08;   /* grey */
3421         init_waitqueue_head(&vc->paste_wait);
3422         reset_terminal(vc, do_clear);
3423 }
3424
3425 /*
3426  * This routine initializes console interrupts, and does nothing
3427  * else. If you want the screen to clear, call tty_write with
3428  * the appropriate escape-sequence.
3429  */
3430
3431 static int __init con_init(void)
3432 {
3433         const char *display_desc = NULL;
3434         struct vc_data *vc;
3435         unsigned int currcons = 0, i;
3436
3437         console_lock();
3438
3439         if (!conswitchp)
3440                 conswitchp = &dummy_con;
3441         display_desc = conswitchp->con_startup();
3442         if (!display_desc) {
3443                 fg_console = 0;
3444                 console_unlock();
3445                 return 0;
3446         }
3447
3448         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3449                 struct con_driver *con_driver = &registered_con_driver[i];
3450
3451                 if (con_driver->con == NULL) {
3452                         con_driver->con = conswitchp;
3453                         con_driver->desc = display_desc;
3454                         con_driver->flag = CON_DRIVER_FLAG_INIT;
3455                         con_driver->first = 0;
3456                         con_driver->last = MAX_NR_CONSOLES - 1;
3457                         break;
3458                 }
3459         }
3460
3461         for (i = 0; i < MAX_NR_CONSOLES; i++)
3462                 con_driver_map[i] = conswitchp;
3463
3464         if (blankinterval) {
3465                 blank_state = blank_normal_wait;
3466                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
3467         }
3468
3469         for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
3470                 vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
3471                 INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
3472                 tty_port_init(&vc->port);
3473                 visual_init(vc, currcons, 1);
3474                 /* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
3475                 vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
3476                 vc_init(vc, vc->vc_rows, vc->vc_cols,
3477                         currcons || !vc->vc_sw->con_save_screen);
3478         }
3479         currcons = fg_console = 0;
3480         master_display_fg = vc = vc_cons[currcons].d;
3481         set_origin(vc);
3482         save_screen(vc);
3483         gotoxy(vc, vc->state.x, vc->state.y);
3484         csi_J(vc, 0);
3485         update_screen(vc);
3486         pr_info("Console: %s %s %dx%d\n",
3487                 vc->vc_can_do_color ? "colour" : "mono",
3488                 display_desc, vc->vc_cols, vc->vc_rows);
3489
3490         console_unlock();
3491
3492 #ifdef CONFIG_VT_CONSOLE
3493         register_console(&vt_console_driver);
3494 #endif
3495         return 0;
3496 }
3497 console_initcall(con_init);
3498
3499 static const struct tty_operations con_ops = {
3500         .install = con_install,
3501         .open = con_open,
3502         .close = con_close,
3503         .write = con_write,
3504         .write_room = con_write_room,
3505         .put_char = con_put_char,
3506         .flush_chars = con_flush_chars,
3507         .ioctl = vt_ioctl,
3508 #ifdef CONFIG_COMPAT
3509         .compat_ioctl = vt_compat_ioctl,
3510 #endif
3511         .stop = con_stop,
3512         .start = con_start,
3513         .throttle = con_throttle,
3514         .unthrottle = con_unthrottle,
3515         .resize = vt_resize,
3516         .shutdown = con_shutdown,
3517         .cleanup = con_cleanup,
3518 };
3519
3520 static struct cdev vc0_cdev;
3521
3522 static ssize_t show_tty_active(struct device *dev,
3523                                 struct device_attribute *attr, char *buf)
3524 {
3525         return sprintf(buf, "tty%d\n", fg_console + 1);
3526 }
3527 static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
3528
3529 static struct attribute *vt_dev_attrs[] = {
3530         &dev_attr_active.attr,
3531         NULL
3532 };
3533
3534 ATTRIBUTE_GROUPS(vt_dev);
3535
3536 int __init vty_init(const struct file_operations *console_fops)
3537 {
3538         cdev_init(&vc0_cdev, console_fops);
3539         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
3540             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
3541                 panic("Couldn't register /dev/tty0 driver\n");
3542         tty0dev = device_create_with_groups(tty_class, NULL,
3543                                             MKDEV(TTY_MAJOR, 0), NULL,
3544                                             vt_dev_groups, "tty0");
3545         if (IS_ERR(tty0dev))
3546                 tty0dev = NULL;
3547
3548         vcs_init();
3549
3550         console_driver = tty_alloc_driver(MAX_NR_CONSOLES, TTY_DRIVER_REAL_RAW |
3551                         TTY_DRIVER_RESET_TERMIOS);
3552         if (IS_ERR(console_driver))
3553                 panic("Couldn't allocate console driver\n");
3554
3555         console_driver->name = "tty";
3556         console_driver->name_base = 1;
3557         console_driver->major = TTY_MAJOR;
3558         console_driver->minor_start = 1;
3559         console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
3560         console_driver->init_termios = tty_std_termios;
3561         if (default_utf8)
3562                 console_driver->init_termios.c_iflag |= IUTF8;
3563         tty_set_operations(console_driver, &con_ops);
3564         if (tty_register_driver(console_driver))
3565                 panic("Couldn't register console driver\n");
3566         kbd_init();
3567         console_map_init();
3568 #ifdef CONFIG_MDA_CONSOLE
3569         mda_console_init();
3570 #endif
3571         return 0;
3572 }
3573
3574 #ifndef VT_SINGLE_DRIVER
3575
3576 static struct class *vtconsole_class;
3577
3578 static int do_bind_con_driver(const struct consw *csw, int first, int last,
3579                            int deflt)
3580 {
3581         struct module *owner = csw->owner;
3582         const char *desc = NULL;
3583         struct con_driver *con_driver;
3584         int i, j = -1, k = -1, retval = -ENODEV;
3585
3586         if (!try_module_get(owner))
3587                 return -ENODEV;
3588
3589         WARN_CONSOLE_UNLOCKED();
3590
3591         /* check if driver is registered */
3592         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3593                 con_driver = &registered_con_driver[i];
3594
3595                 if (con_driver->con == csw) {
3596                         desc = con_driver->desc;
3597                         retval = 0;
3598                         break;
3599                 }
3600         }
3601
3602         if (retval)
3603                 goto err;
3604
3605         if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
3606                 csw->con_startup();
3607                 con_driver->flag |= CON_DRIVER_FLAG_INIT;
3608         }
3609
3610         if (deflt) {
3611                 if (conswitchp)
3612                         module_put(conswitchp->owner);
3613
3614                 __module_get(owner);
3615                 conswitchp = csw;
3616         }
3617
3618         first = max(first, con_driver->first);
3619         last = min(last, con_driver->last);
3620
3621         for (i = first; i <= last; i++) {
3622                 int old_was_color;
3623                 struct vc_data *vc = vc_cons[i].d;
3624
3625                 if (con_driver_map[i])
3626                         module_put(con_driver_map[i]->owner);
3627                 __module_get(owner);
3628                 con_driver_map[i] = csw;
3629
3630                 if (!vc || !vc->vc_sw)
3631                         continue;
3632
3633                 j = i;
3634
3635                 if (con_is_visible(vc)) {
3636                         k = i;
3637                         save_screen(vc);
3638                 }
3639
3640                 old_was_color = vc->vc_can_do_color;
3641                 vc->vc_sw->con_deinit(vc);
3642                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
3643                 visual_init(vc, i, 0);
3644                 set_origin(vc);
3645                 update_attr(vc);
3646
3647                 /* If the console changed between mono <-> color, then
3648                  * the attributes in the screenbuf will be wrong.  The
3649                  * following resets all attributes to something sane.
3650                  */
3651                 if (old_was_color != vc->vc_can_do_color)
3652                         clear_buffer_attributes(vc);
3653         }
3654
3655         pr_info("Console: switching ");
3656         if (!deflt)
3657                 pr_cont("consoles %d-%d ", first + 1, last + 1);
3658         if (j >= 0) {
3659                 struct vc_data *vc = vc_cons[j].d;
3660
3661                 pr_cont("to %s %s %dx%d\n",
3662                         vc->vc_can_do_color ? "colour" : "mono",
3663                         desc, vc->vc_cols, vc->vc_rows);
3664
3665                 if (k >= 0) {
3666                         vc = vc_cons[k].d;
3667                         update_screen(vc);
3668                 }
3669         } else {
3670                 pr_cont("to %s\n", desc);
3671         }
3672
3673         retval = 0;
3674 err:
3675         module_put(owner);
3676         return retval;
3677 };
3678
3679
3680 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
3681 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
3682 {
3683         struct module *owner = csw->owner;
3684         const struct consw *defcsw = NULL;
3685         struct con_driver *con_driver = NULL, *con_back = NULL;
3686         int i, retval = -ENODEV;
3687
3688         if (!try_module_get(owner))
3689                 return -ENODEV;
3690
3691         WARN_CONSOLE_UNLOCKED();
3692
3693         /* check if driver is registered and if it is unbindable */
3694         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3695                 con_driver = &registered_con_driver[i];
3696
3697                 if (con_driver->con == csw &&
3698                     con_driver->flag & CON_DRIVER_FLAG_MODULE) {
3699                         retval = 0;
3700                         break;
3701                 }
3702         }
3703
3704         if (retval)
3705                 goto err;
3706
3707         retval = -ENODEV;
3708
3709         /* check if backup driver exists */
3710         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3711                 con_back = &registered_con_driver[i];
3712
3713                 if (con_back->con && con_back->con != csw) {
3714                         defcsw = con_back->con;
3715                         retval = 0;
3716                         break;
3717                 }
3718         }
3719
3720         if (retval)
3721                 goto err;
3722
3723         if (!con_is_bound(csw))
3724                 goto err;
3725
3726         first = max(first, con_driver->first);
3727         last = min(last, con_driver->last);
3728
3729         for (i = first; i <= last; i++) {
3730                 if (con_driver_map[i] == csw) {
3731                         module_put(csw->owner);
3732                         con_driver_map[i] = NULL;
3733                 }
3734         }
3735
3736         if (!con_is_bound(defcsw)) {
3737                 const struct consw *defconsw = conswitchp;
3738
3739                 defcsw->con_startup();
3740                 con_back->flag |= CON_DRIVER_FLAG_INIT;
3741                 /*
3742                  * vgacon may change the default driver to point
3743                  * to dummycon, we restore it here...
3744                  */
3745                 conswitchp = defconsw;
3746         }
3747
3748         if (!con_is_bound(csw))
3749                 con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
3750
3751         /* ignore return value, binding should not fail */
3752         do_bind_con_driver(defcsw, first, last, deflt);
3753 err:
3754         module_put(owner);
3755         return retval;
3756
3757 }
3758 EXPORT_SYMBOL_GPL(do_unbind_con_driver);
3759
3760 static int vt_bind(struct con_driver *con)
3761 {
3762         const struct consw *defcsw = NULL, *csw = NULL;
3763         int i, more = 1, first = -1, last = -1, deflt = 0;
3764
3765         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3766                 goto err;
3767
3768         csw = con->con;
3769
3770         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
3771                 struct con_driver *con = &registered_con_driver[i];
3772
3773                 if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
3774                         defcsw = con->con;
3775                         break;
3776                 }
3777         }
3778
3779         if (!defcsw)
3780                 goto err;
3781
3782         while (more) {
3783                 more = 0;
3784
3785                 for (i = con->first; i <= con->last; i++) {
3786                         if (con_driver_map[i] == defcsw) {
3787                                 if (first == -1)
3788                                         first = i;
3789                                 last = i;
3790                                 more = 1;
3791                         } else if (first != -1)
3792                                 break;
3793                 }
3794
3795                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3796                         deflt = 1;
3797
3798                 if (first != -1)
3799                         do_bind_con_driver(csw, first, last, deflt);
3800
3801                 first = -1;
3802                 last = -1;
3803                 deflt = 0;
3804         }
3805
3806 err:
3807         return 0;
3808 }
3809
3810 static int vt_unbind(struct con_driver *con)
3811 {
3812         const struct consw *csw = NULL;
3813         int i, more = 1, first = -1, last = -1, deflt = 0;
3814         int ret;
3815
3816         if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
3817                 goto err;
3818
3819         csw = con->con;
3820
3821         while (more) {
3822                 more = 0;
3823
3824                 for (i = con->first; i <= con->last; i++) {
3825                         if (con_driver_map[i] == csw) {
3826                                 if (first == -1)
3827                                         first = i;
3828                                 last = i;
3829                                 more = 1;
3830                         } else if (first != -1)
3831                                 break;
3832                 }
3833
3834                 if (first == 0 && last == MAX_NR_CONSOLES -1)
3835                         deflt = 1;
3836
3837                 if (first != -1) {
3838                         ret = do_unbind_con_driver(csw, first, last, deflt);
3839                         if (ret != 0)
3840                                 return ret;
3841                 }
3842
3843                 first = -1;
3844                 last = -1;
3845                 deflt = 0;
3846         }
3847
3848 err:
3849         return 0;
3850 }
3851 #else
3852 static inline int vt_bind(struct con_driver *con)
3853 {
3854         return 0;
3855 }
3856 static inline int vt_unbind(struct con_driver *con)
3857 {
3858         return 0;
3859 }
3860 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
3861
3862 static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
3863                           const char *buf, size_t count)
3864 {
3865         struct con_driver *con = dev_get_drvdata(dev);
3866         int bind = simple_strtoul(buf, NULL, 0);
3867
3868         console_lock();
3869
3870         if (bind)
3871                 vt_bind(con);
3872         else
3873                 vt_unbind(con);
3874
3875         console_unlock();
3876
3877         return count;
3878 }
3879
3880 static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
3881                          char *buf)
3882 {
3883         struct con_driver *con = dev_get_drvdata(dev);
3884         int bind;
3885
3886         console_lock();
3887         bind = con_is_bound(con->con);
3888         console_unlock();
3889
3890         return sysfs_emit(buf, "%i\n", bind);
3891 }
3892
3893 static ssize_t show_name(struct device *dev, struct device_attribute *attr,
3894                          char *buf)
3895 {
3896         struct con_driver *con = dev_get_drvdata(dev);
3897
3898         return sysfs_emit(buf, "%s %s\n",
3899                         (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
3900                          con->desc);
3901
3902 }
3903
3904 static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
3905 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
3906
3907 static struct attribute *con_dev_attrs[] = {
3908         &dev_attr_bind.attr,
3909         &dev_attr_name.attr,
3910         NULL
3911 };
3912
3913 ATTRIBUTE_GROUPS(con_dev);
3914
3915 static int vtconsole_init_device(struct con_driver *con)
3916 {
3917         con->flag |= CON_DRIVER_FLAG_ATTR;
3918         return 0;
3919 }
3920
3921 static void vtconsole_deinit_device(struct con_driver *con)
3922 {
3923         con->flag &= ~CON_DRIVER_FLAG_ATTR;
3924 }
3925
3926 /**
3927  * con_is_bound - checks if driver is bound to the console
3928  * @csw: console driver
3929  *
3930  * RETURNS: zero if unbound, nonzero if bound
3931  *
3932  * Drivers can call this and if zero, they should release
3933  * all resources allocated on con_startup()
3934  */
3935 int con_is_bound(const struct consw *csw)
3936 {
3937         int i, bound = 0;
3938
3939         WARN_CONSOLE_UNLOCKED();
3940
3941         for (i = 0; i < MAX_NR_CONSOLES; i++) {
3942                 if (con_driver_map[i] == csw) {
3943                         bound = 1;
3944                         break;
3945                 }
3946         }
3947
3948         return bound;
3949 }
3950 EXPORT_SYMBOL(con_is_bound);
3951
3952 /**
3953  * con_is_visible - checks whether the current console is visible
3954  * @vc: virtual console
3955  *
3956  * RETURNS: zero if not visible, nonzero if visible
3957  */
3958 bool con_is_visible(const struct vc_data *vc)
3959 {
3960         WARN_CONSOLE_UNLOCKED();
3961
3962         return *vc->vc_display_fg == vc;
3963 }
3964 EXPORT_SYMBOL(con_is_visible);
3965
3966 /**
3967  * con_debug_enter - prepare the console for the kernel debugger
3968  * @vc: virtual console
3969  *
3970  * Called when the console is taken over by the kernel debugger, this
3971  * function needs to save the current console state, then put the console
3972  * into a state suitable for the kernel debugger.
3973  *
3974  * RETURNS:
3975  * Zero on success, nonzero if a failure occurred when trying to prepare
3976  * the console for the debugger.
3977  */
3978 int con_debug_enter(struct vc_data *vc)
3979 {
3980         int ret = 0;
3981
3982         saved_fg_console = fg_console;
3983         saved_last_console = last_console;
3984         saved_want_console = want_console;
3985         saved_vc_mode = vc->vc_mode;
3986         saved_console_blanked = console_blanked;
3987         vc->vc_mode = KD_TEXT;
3988         console_blanked = 0;
3989         if (vc->vc_sw->con_debug_enter)
3990                 ret = vc->vc_sw->con_debug_enter(vc);
3991 #ifdef CONFIG_KGDB_KDB
3992         /* Set the initial LINES variable if it is not already set */
3993         if (vc->vc_rows < 999) {
3994                 int linecount;
3995                 char lns[4];
3996                 const char *setargs[3] = {
3997                         "set",
3998                         "LINES",
3999                         lns,
4000                 };
4001                 if (kdbgetintenv(setargs[0], &linecount)) {
4002                         snprintf(lns, 4, "%i", vc->vc_rows);
4003                         kdb_set(2, setargs);
4004                 }
4005         }
4006         if (vc->vc_cols < 999) {
4007                 int colcount;
4008                 char cols[4];
4009                 const char *setargs[3] = {
4010                         "set",
4011                         "COLUMNS",
4012                         cols,
4013                 };
4014                 if (kdbgetintenv(setargs[0], &colcount)) {
4015                         snprintf(cols, 4, "%i", vc->vc_cols);
4016                         kdb_set(2, setargs);
4017                 }
4018         }
4019 #endif /* CONFIG_KGDB_KDB */
4020         return ret;
4021 }
4022 EXPORT_SYMBOL_GPL(con_debug_enter);
4023
4024 /**
4025  * con_debug_leave - restore console state
4026  *
4027  * Restore the console state to what it was before the kernel debugger
4028  * was invoked.
4029  *
4030  * RETURNS:
4031  * Zero on success, nonzero if a failure occurred when trying to restore
4032  * the console.
4033  */
4034 int con_debug_leave(void)
4035 {
4036         struct vc_data *vc;
4037         int ret = 0;
4038
4039         fg_console = saved_fg_console;
4040         last_console = saved_last_console;
4041         want_console = saved_want_console;
4042         console_blanked = saved_console_blanked;
4043         vc_cons[fg_console].d->vc_mode = saved_vc_mode;
4044
4045         vc = vc_cons[fg_console].d;
4046         if (vc->vc_sw->con_debug_leave)
4047                 ret = vc->vc_sw->con_debug_leave(vc);
4048         return ret;
4049 }
4050 EXPORT_SYMBOL_GPL(con_debug_leave);
4051
4052 static int do_register_con_driver(const struct consw *csw, int first, int last)
4053 {
4054         struct module *owner = csw->owner;
4055         struct con_driver *con_driver;
4056         const char *desc;
4057         int i, retval;
4058
4059         WARN_CONSOLE_UNLOCKED();
4060
4061         if (!try_module_get(owner))
4062                 return -ENODEV;
4063
4064         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4065                 con_driver = &registered_con_driver[i];
4066
4067                 /* already registered */
4068                 if (con_driver->con == csw) {
4069                         retval = -EBUSY;
4070                         goto err;
4071                 }
4072         }
4073
4074         desc = csw->con_startup();
4075         if (!desc) {
4076                 retval = -ENODEV;
4077                 goto err;
4078         }
4079
4080         retval = -EINVAL;
4081
4082         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4083                 con_driver = &registered_con_driver[i];
4084
4085                 if (con_driver->con == NULL &&
4086                     !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
4087                         con_driver->con = csw;
4088                         con_driver->desc = desc;
4089                         con_driver->node = i;
4090                         con_driver->flag = CON_DRIVER_FLAG_MODULE |
4091                                            CON_DRIVER_FLAG_INIT;
4092                         con_driver->first = first;
4093                         con_driver->last = last;
4094                         retval = 0;
4095                         break;
4096                 }
4097         }
4098
4099         if (retval)
4100                 goto err;
4101
4102         con_driver->dev =
4103                 device_create_with_groups(vtconsole_class, NULL,
4104                                           MKDEV(0, con_driver->node),
4105                                           con_driver, con_dev_groups,
4106                                           "vtcon%i", con_driver->node);
4107         if (IS_ERR(con_driver->dev)) {
4108                 pr_warn("Unable to create device for %s; errno = %ld\n",
4109                         con_driver->desc, PTR_ERR(con_driver->dev));
4110                 con_driver->dev = NULL;
4111         } else {
4112                 vtconsole_init_device(con_driver);
4113         }
4114
4115 err:
4116         module_put(owner);
4117         return retval;
4118 }
4119
4120
4121 /**
4122  * do_unregister_con_driver - unregister console driver from console layer
4123  * @csw: console driver
4124  *
4125  * DESCRIPTION: All drivers that registers to the console layer must
4126  * call this function upon exit, or if the console driver is in a state
4127  * where it won't be able to handle console services, such as the
4128  * framebuffer console without loaded framebuffer drivers.
4129  *
4130  * The driver must unbind first prior to unregistration.
4131  */
4132 int do_unregister_con_driver(const struct consw *csw)
4133 {
4134         int i;
4135
4136         /* cannot unregister a bound driver */
4137         if (con_is_bound(csw))
4138                 return -EBUSY;
4139
4140         if (csw == conswitchp)
4141                 return -EINVAL;
4142
4143         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4144                 struct con_driver *con_driver = &registered_con_driver[i];
4145
4146                 if (con_driver->con == csw) {
4147                         /*
4148                          * Defer the removal of the sysfs entries since that
4149                          * will acquire the kernfs s_active lock and we can't
4150                          * acquire this lock while holding the console lock:
4151                          * the unbind sysfs entry imposes already the opposite
4152                          * order. Reset con already here to prevent any later
4153                          * lookup to succeed and mark this slot as zombie, so
4154                          * it won't get reused until we complete the removal
4155                          * in the deferred work.
4156                          */
4157                         con_driver->con = NULL;
4158                         con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
4159                         schedule_work(&con_driver_unregister_work);
4160
4161                         return 0;
4162                 }
4163         }
4164
4165         return -ENODEV;
4166 }
4167 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
4168
4169 static void con_driver_unregister_callback(struct work_struct *ignored)
4170 {
4171         int i;
4172
4173         console_lock();
4174
4175         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4176                 struct con_driver *con_driver = &registered_con_driver[i];
4177
4178                 if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
4179                         continue;
4180
4181                 console_unlock();
4182
4183                 vtconsole_deinit_device(con_driver);
4184                 device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
4185
4186                 console_lock();
4187
4188                 if (WARN_ON_ONCE(con_driver->con))
4189                         con_driver->con = NULL;
4190                 con_driver->desc = NULL;
4191                 con_driver->dev = NULL;
4192                 con_driver->node = 0;
4193                 WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
4194                 con_driver->flag = 0;
4195                 con_driver->first = 0;
4196                 con_driver->last = 0;
4197         }
4198
4199         console_unlock();
4200 }
4201
4202 /*
4203  *      If we support more console drivers, this function is used
4204  *      when a driver wants to take over some existing consoles
4205  *      and become default driver for newly opened ones.
4206  *
4207  *      do_take_over_console is basically a register followed by bind
4208  */
4209 int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
4210 {
4211         int err;
4212
4213         err = do_register_con_driver(csw, first, last);
4214         /*
4215          * If we get an busy error we still want to bind the console driver
4216          * and return success, as we may have unbound the console driver
4217          * but not unregistered it.
4218          */
4219         if (err == -EBUSY)
4220                 err = 0;
4221         if (!err)
4222                 do_bind_con_driver(csw, first, last, deflt);
4223
4224         return err;
4225 }
4226 EXPORT_SYMBOL_GPL(do_take_over_console);
4227
4228
4229 /*
4230  * give_up_console is a wrapper to unregister_con_driver. It will only
4231  * work if driver is fully unbound.
4232  */
4233 void give_up_console(const struct consw *csw)
4234 {
4235         console_lock();
4236         do_unregister_con_driver(csw);
4237         console_unlock();
4238 }
4239
4240 static int __init vtconsole_class_init(void)
4241 {
4242         int i;
4243
4244         vtconsole_class = class_create(THIS_MODULE, "vtconsole");
4245         if (IS_ERR(vtconsole_class)) {
4246                 pr_warn("Unable to create vt console class; errno = %ld\n",
4247                         PTR_ERR(vtconsole_class));
4248                 vtconsole_class = NULL;
4249         }
4250
4251         /* Add system drivers to sysfs */
4252         for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
4253                 struct con_driver *con = &registered_con_driver[i];
4254
4255                 if (con->con && !con->dev) {
4256                         con->dev =
4257                                 device_create_with_groups(vtconsole_class, NULL,
4258                                                           MKDEV(0, con->node),
4259                                                           con, con_dev_groups,
4260                                                           "vtcon%i", con->node);
4261
4262                         if (IS_ERR(con->dev)) {
4263                                 pr_warn("Unable to create device for %s; errno = %ld\n",
4264                                         con->desc, PTR_ERR(con->dev));
4265                                 con->dev = NULL;
4266                         } else {
4267                                 vtconsole_init_device(con);
4268                         }
4269                 }
4270         }
4271
4272         return 0;
4273 }
4274 postcore_initcall(vtconsole_class_init);
4275
4276 #endif
4277
4278 /*
4279  *      Screen blanking
4280  */
4281
4282 static int set_vesa_blanking(char __user *p)
4283 {
4284         unsigned int mode;
4285
4286         if (get_user(mode, p + 1))
4287                 return -EFAULT;
4288
4289         vesa_blank_mode = (mode < 4) ? mode : 0;
4290         return 0;
4291 }
4292
4293 void do_blank_screen(int entering_gfx)
4294 {
4295         struct vc_data *vc = vc_cons[fg_console].d;
4296         int i;
4297
4298         might_sleep();
4299
4300         WARN_CONSOLE_UNLOCKED();
4301
4302         if (console_blanked) {
4303                 if (blank_state == blank_vesa_wait) {
4304                         blank_state = blank_off;
4305                         vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
4306                 }
4307                 return;
4308         }
4309
4310         /* entering graphics mode? */
4311         if (entering_gfx) {
4312                 hide_cursor(vc);
4313                 save_screen(vc);
4314                 vc->vc_sw->con_blank(vc, -1, 1);
4315                 console_blanked = fg_console + 1;
4316                 blank_state = blank_off;
4317                 set_origin(vc);
4318                 return;
4319         }
4320
4321         blank_state = blank_off;
4322
4323         /* don't blank graphics */
4324         if (vc->vc_mode != KD_TEXT) {
4325                 console_blanked = fg_console + 1;
4326                 return;
4327         }
4328
4329         hide_cursor(vc);
4330         del_timer_sync(&console_timer);
4331         blank_timer_expired = 0;
4332
4333         save_screen(vc);
4334         /* In case we need to reset origin, blanking hook returns 1 */
4335         i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
4336         console_blanked = fg_console + 1;
4337         if (i)
4338                 set_origin(vc);
4339
4340         if (console_blank_hook && console_blank_hook(1))
4341                 return;
4342
4343         if (vesa_off_interval && vesa_blank_mode) {
4344                 blank_state = blank_vesa_wait;
4345                 mod_timer(&console_timer, jiffies + vesa_off_interval);
4346         }
4347         vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
4348 }
4349 EXPORT_SYMBOL(do_blank_screen);
4350
4351 /*
4352  * Called by timer as well as from vt_console_driver
4353  */
4354 void do_unblank_screen(int leaving_gfx)
4355 {
4356         struct vc_data *vc;
4357
4358         /* This should now always be called from a "sane" (read: can schedule)
4359          * context for the sake of the low level drivers, except in the special
4360          * case of oops_in_progress
4361          */
4362         if (!oops_in_progress)
4363                 might_sleep();
4364
4365         WARN_CONSOLE_UNLOCKED();
4366
4367         ignore_poke = 0;
4368         if (!console_blanked)
4369                 return;
4370         if (!vc_cons_allocated(fg_console)) {
4371                 /* impossible */
4372                 pr_warn("unblank_screen: tty %d not allocated ??\n",
4373                         fg_console + 1);
4374                 return;
4375         }
4376         vc = vc_cons[fg_console].d;
4377         if (vc->vc_mode != KD_TEXT)
4378                 return; /* but leave console_blanked != 0 */
4379
4380         if (blankinterval) {
4381                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4382                 blank_state = blank_normal_wait;
4383         }
4384
4385         console_blanked = 0;
4386         if (vc->vc_sw->con_blank(vc, 0, leaving_gfx))
4387                 /* Low-level driver cannot restore -> do it ourselves */
4388                 update_screen(vc);
4389         if (console_blank_hook)
4390                 console_blank_hook(0);
4391         set_palette(vc);
4392         set_cursor(vc);
4393         vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
4394 }
4395 EXPORT_SYMBOL(do_unblank_screen);
4396
4397 /*
4398  * This is called by the outside world to cause a forced unblank, mostly for
4399  * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
4400  * call it with 1 as an argument and so force a mode restore... that may kill
4401  * X or at least garbage the screen but would also make the Oops visible...
4402  */
4403 static void unblank_screen(void)
4404 {
4405         do_unblank_screen(0);
4406 }
4407
4408 /*
4409  * We defer the timer blanking to work queue so it can take the console mutex
4410  * (console operations can still happen at irq time, but only from printk which
4411  * has the console mutex. Not perfect yet, but better than no locking
4412  */
4413 static void blank_screen_t(struct timer_list *unused)
4414 {
4415         blank_timer_expired = 1;
4416         schedule_work(&console_work);
4417 }
4418
4419 void poke_blanked_console(void)
4420 {
4421         WARN_CONSOLE_UNLOCKED();
4422
4423         /* Add this so we quickly catch whoever might call us in a non
4424          * safe context. Nowadays, unblank_screen() isn't to be called in
4425          * atomic contexts and is allowed to schedule (with the special case
4426          * of oops_in_progress, but that isn't of any concern for this
4427          * function. --BenH.
4428          */
4429         might_sleep();
4430
4431         /* This isn't perfectly race free, but a race here would be mostly harmless,
4432          * at worst, we'll do a spurious blank and it's unlikely
4433          */
4434         del_timer(&console_timer);
4435         blank_timer_expired = 0;
4436
4437         if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
4438                 return;
4439         if (console_blanked)
4440                 unblank_screen();
4441         else if (blankinterval) {
4442                 mod_timer(&console_timer, jiffies + (blankinterval * HZ));
4443                 blank_state = blank_normal_wait;
4444         }
4445 }
4446
4447 /*
4448  *      Palettes
4449  */
4450
4451 static void set_palette(struct vc_data *vc)
4452 {
4453         WARN_CONSOLE_UNLOCKED();
4454
4455         if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_set_palette)
4456                 vc->vc_sw->con_set_palette(vc, color_table);
4457 }
4458
4459 /*
4460  * Load palette into the DAC registers. arg points to a colour
4461  * map, 3 bytes per colour, 16 colours, range from 0 to 255.
4462  */
4463
4464 int con_set_cmap(unsigned char __user *arg)
4465 {
4466         int i, j, k;
4467         unsigned char colormap[3*16];
4468
4469         if (copy_from_user(colormap, arg, sizeof(colormap)))
4470                 return -EFAULT;
4471
4472         console_lock();
4473         for (i = k = 0; i < 16; i++) {
4474                 default_red[i] = colormap[k++];
4475                 default_grn[i] = colormap[k++];
4476                 default_blu[i] = colormap[k++];
4477         }
4478         for (i = 0; i < MAX_NR_CONSOLES; i++) {
4479                 if (!vc_cons_allocated(i))
4480                         continue;
4481                 for (j = k = 0; j < 16; j++) {
4482                         vc_cons[i].d->vc_palette[k++] = default_red[j];
4483                         vc_cons[i].d->vc_palette[k++] = default_grn[j];
4484                         vc_cons[i].d->vc_palette[k++] = default_blu[j];
4485                 }
4486                 set_palette(vc_cons[i].d);
4487         }
4488         console_unlock();
4489
4490         return 0;
4491 }
4492
4493 int con_get_cmap(unsigned char __user *arg)
4494 {
4495         int i, k;
4496         unsigned char colormap[3*16];
4497
4498         console_lock();
4499         for (i = k = 0; i < 16; i++) {
4500                 colormap[k++] = default_red[i];
4501                 colormap[k++] = default_grn[i];
4502                 colormap[k++] = default_blu[i];
4503         }
4504         console_unlock();
4505
4506         if (copy_to_user(arg, colormap, sizeof(colormap)))
4507                 return -EFAULT;
4508
4509         return 0;
4510 }
4511
4512 void reset_palette(struct vc_data *vc)
4513 {
4514         int j, k;
4515         for (j=k=0; j<16; j++) {
4516                 vc->vc_palette[k++] = default_red[j];
4517                 vc->vc_palette[k++] = default_grn[j];
4518                 vc->vc_palette[k++] = default_blu[j];
4519         }
4520         set_palette(vc);
4521 }
4522
4523 /*
4524  *  Font switching
4525  *
4526  *  Currently we only support fonts up to 128 pixels wide, at a maximum height
4527  *  of 128 pixels. Userspace fontdata may have to be stored with 32 bytes
4528  *  (shorts/ints, depending on width) reserved for each character which is
4529  *  kinda wasty, but this is done in order to maintain compatibility with the
4530  *  EGA/VGA fonts. It is up to the actual low-level console-driver convert data
4531  *  into its favorite format (maybe we should add a `fontoffset' field to the
4532  *  `display' structure so we won't have to convert the fontdata all the time.
4533  *  /Jes
4534  */
4535
4536 #define max_font_width  64
4537 #define max_font_height 128
4538 #define max_font_glyphs 512
4539 #define max_font_size   (max_font_glyphs*max_font_width*max_font_height)
4540
4541 static int con_font_get(struct vc_data *vc, struct console_font_op *op)
4542 {
4543         struct console_font font;
4544         int rc = -EINVAL;
4545         int c;
4546         unsigned int vpitch = op->op == KD_FONT_OP_GET_TALL ? op->height : 32;
4547
4548         if (vpitch > max_font_height)
4549                 return -EINVAL;
4550
4551         if (op->data) {
4552                 font.data = kvmalloc(max_font_size, GFP_KERNEL);
4553                 if (!font.data)
4554                         return -ENOMEM;
4555         } else
4556                 font.data = NULL;
4557
4558         console_lock();
4559         if (vc->vc_mode != KD_TEXT)
4560                 rc = -EINVAL;
4561         else if (vc->vc_sw->con_font_get)
4562                 rc = vc->vc_sw->con_font_get(vc, &font, vpitch);
4563         else
4564                 rc = -ENOSYS;
4565         console_unlock();
4566
4567         if (rc)
4568                 goto out;
4569
4570         c = (font.width+7)/8 * vpitch * font.charcount;
4571
4572         if (op->data && font.charcount > op->charcount)
4573                 rc = -ENOSPC;
4574         if (font.width > op->width || font.height > op->height)
4575                 rc = -ENOSPC;
4576         if (rc)
4577                 goto out;
4578
4579         op->height = font.height;
4580         op->width = font.width;
4581         op->charcount = font.charcount;
4582
4583         if (op->data && copy_to_user(op->data, font.data, c))
4584                 rc = -EFAULT;
4585
4586 out:
4587         kvfree(font.data);
4588         return rc;
4589 }
4590
4591 static int con_font_set(struct vc_data *vc, struct console_font_op *op)
4592 {
4593         struct console_font font;
4594         int rc = -EINVAL;
4595         int size;
4596         unsigned int vpitch = op->op == KD_FONT_OP_SET_TALL ? op->height : 32;
4597
4598         if (vc->vc_mode != KD_TEXT)
4599                 return -EINVAL;
4600         if (!op->data)
4601                 return -EINVAL;
4602         if (op->charcount > max_font_glyphs)
4603                 return -EINVAL;
4604         if (op->width <= 0 || op->width > max_font_width || !op->height ||
4605             op->height > max_font_height)
4606                 return -EINVAL;
4607         if (vpitch < op->height)
4608                 return -EINVAL;
4609         size = (op->width+7)/8 * vpitch * op->charcount;
4610         if (size > max_font_size)
4611                 return -ENOSPC;
4612
4613         font.data = memdup_user(op->data, size);
4614         if (IS_ERR(font.data))
4615                 return PTR_ERR(font.data);
4616
4617         font.charcount = op->charcount;
4618         font.width = op->width;
4619         font.height = op->height;
4620
4621         console_lock();
4622         if (vc->vc_mode != KD_TEXT)
4623                 rc = -EINVAL;
4624         else if (vc->vc_sw->con_font_set) {
4625                 if (vc_is_sel(vc))
4626                         clear_selection();
4627                 rc = vc->vc_sw->con_font_set(vc, &font, vpitch, op->flags);
4628         } else
4629                 rc = -ENOSYS;
4630         console_unlock();
4631         kfree(font.data);
4632         return rc;
4633 }
4634
4635 static int con_font_default(struct vc_data *vc, struct console_font_op *op)
4636 {
4637         struct console_font font = {.width = op->width, .height = op->height};
4638         char name[MAX_FONT_NAME];
4639         char *s = name;
4640         int rc;
4641
4642
4643         if (!op->data)
4644                 s = NULL;
4645         else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
4646                 return -EFAULT;
4647         else
4648                 name[MAX_FONT_NAME - 1] = 0;
4649
4650         console_lock();
4651         if (vc->vc_mode != KD_TEXT) {
4652                 console_unlock();
4653                 return -EINVAL;
4654         }
4655         if (vc->vc_sw->con_font_default) {
4656                 if (vc_is_sel(vc))
4657                         clear_selection();
4658                 rc = vc->vc_sw->con_font_default(vc, &font, s);
4659         } else
4660                 rc = -ENOSYS;
4661         console_unlock();
4662         if (!rc) {
4663                 op->width = font.width;
4664                 op->height = font.height;
4665         }
4666         return rc;
4667 }
4668
4669 int con_font_op(struct vc_data *vc, struct console_font_op *op)
4670 {
4671         switch (op->op) {
4672         case KD_FONT_OP_SET:
4673         case KD_FONT_OP_SET_TALL:
4674                 return con_font_set(vc, op);
4675         case KD_FONT_OP_GET:
4676         case KD_FONT_OP_GET_TALL:
4677                 return con_font_get(vc, op);
4678         case KD_FONT_OP_SET_DEFAULT:
4679                 return con_font_default(vc, op);
4680         case KD_FONT_OP_COPY:
4681                 /* was buggy and never really used */
4682                 return -EINVAL;
4683         }
4684         return -ENOSYS;
4685 }
4686
4687 /*
4688  *      Interface exported to selection and vcs.
4689  */
4690
4691 /* used by selection */
4692 u16 screen_glyph(const struct vc_data *vc, int offset)
4693 {
4694         u16 w = scr_readw(screenpos(vc, offset, true));
4695         u16 c = w & 0xff;
4696
4697         if (w & vc->vc_hi_font_mask)
4698                 c |= 0x100;
4699         return c;
4700 }
4701 EXPORT_SYMBOL_GPL(screen_glyph);
4702
4703 u32 screen_glyph_unicode(const struct vc_data *vc, int n)
4704 {
4705         u32 **uni_lines = vc->vc_uni_lines;
4706
4707         if (uni_lines)
4708                 return uni_lines[n / vc->vc_cols][n % vc->vc_cols];
4709
4710         return inverse_translate(vc, screen_glyph(vc, n * 2), true);
4711 }
4712 EXPORT_SYMBOL_GPL(screen_glyph_unicode);
4713
4714 /* used by vcs - note the word offset */
4715 unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
4716 {
4717         return screenpos(vc, 2 * w_offset, viewed);
4718 }
4719 EXPORT_SYMBOL_GPL(screen_pos);
4720
4721 void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
4722 {
4723         /* clamp values if they don't fit */
4724         xy[0] = min(vc->state.x, 0xFFu);
4725         xy[1] = min(vc->state.y, 0xFFu);
4726 }
4727
4728 void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
4729 {
4730         hide_cursor(vc);
4731         gotoxy(vc, xy[0], xy[1]);
4732         set_cursor(vc);
4733 }
4734
4735 u16 vcs_scr_readw(const struct vc_data *vc, const u16 *org)
4736 {
4737         if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
4738                 return softcursor_original;
4739         return scr_readw(org);
4740 }
4741
4742 void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
4743 {
4744         scr_writew(val, org);
4745         if ((unsigned long)org == vc->vc_pos) {
4746                 softcursor_original = -1;
4747                 add_softcursor(vc);
4748         }
4749 }
4750
4751 void vcs_scr_updated(struct vc_data *vc)
4752 {
4753         notify_update(vc);
4754 }
4755
4756 void vc_scrolldelta_helper(struct vc_data *c, int lines,
4757                 unsigned int rolled_over, void *base, unsigned int size)
4758 {
4759         unsigned long ubase = (unsigned long)base;
4760         ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
4761         ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
4762         ptrdiff_t origin = (void *)c->vc_origin - base;
4763         int margin = c->vc_size_row * 4;
4764         int from, wrap, from_off, avail;
4765
4766         /* Turn scrollback off */
4767         if (!lines) {
4768                 c->vc_visible_origin = c->vc_origin;
4769                 return;
4770         }
4771
4772         /* Do we have already enough to allow jumping from 0 to the end? */
4773         if (rolled_over > scr_end + margin) {
4774                 from = scr_end;
4775                 wrap = rolled_over + c->vc_size_row;
4776         } else {
4777                 from = 0;
4778                 wrap = size;
4779         }
4780
4781         from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
4782         avail = (origin - from + wrap) % wrap;
4783
4784         /* Only a little piece would be left? Show all incl. the piece! */
4785         if (avail < 2 * margin)
4786                 margin = 0;
4787         if (from_off < margin)
4788                 from_off = 0;
4789         if (from_off > avail - margin)
4790                 from_off = avail;
4791
4792         c->vc_visible_origin = ubase + (from + from_off) % wrap;
4793 }
4794 EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);
4795
4796 /*
4797  *      Visible symbols for modules
4798  */
4799
4800 EXPORT_SYMBOL(color_table);
4801 EXPORT_SYMBOL(default_red);
4802 EXPORT_SYMBOL(default_grn);
4803 EXPORT_SYMBOL(default_blu);
4804 EXPORT_SYMBOL(update_region);
4805 EXPORT_SYMBOL(redraw_screen);
4806 EXPORT_SYMBOL(vc_resize);
4807 EXPORT_SYMBOL(fg_console);
4808 EXPORT_SYMBOL(console_blank_hook);
4809 EXPORT_SYMBOL(console_blanked);
4810 EXPORT_SYMBOL(vc_cons);
4811 EXPORT_SYMBOL(global_cursor_default);
4812 #ifndef VT_SINGLE_DRIVER
4813 EXPORT_SYMBOL(give_up_console);
4814 #endif