arch/um/drivers/line.c

   1 /*
   2  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/irqreturn.h"
   7 #include "linux/kd.h"
   8 #include "chan_kern.h"
   9 #include "irq_kern.h"
  10 #include "irq_user.h"
  11 #include "kern_util.h"
  12 #include "os.h"
  13
  14 #define LINE_BUFSIZE 4096
  15
  16 static irqreturn_t line_interrupt(int irq, void *data)
  17 {
  18         struct chan *chan = data;
  19         struct line *line = chan->line;
  20         struct tty_struct *tty = line->tty;
  21
  22         if (line)
  23                 chan_interrupt(&line->chan_list, &line->task, tty, irq);
  24         return IRQ_HANDLED;
  25 }
  26
  27 static void line_timer_cb(struct work_struct *work)
  28 {
  29         struct line *line = container_of(work, struct line, task.work);
  30
  31         if (!line->throttled)
  32                 chan_interrupt(&line->chan_list, &line->task, line->tty,
  33                                line->driver->read_irq);
  34 }
  35
  36 /*
  37  * Returns the free space inside the ring buffer of this line.
  38  *
  39  * Should be called while holding line->lock (this does not modify data).
  40  */
  41 static int write_room(struct line *line)
  42 {
  43         int n;
  44
  45         if (line->buffer == NULL)
  46                 return LINE_BUFSIZE - 1;
  47
  48         /* This is for the case where the buffer is wrapped! */
  49         n = line->head - line->tail;
  50
  51         if (n <= 0)
  52                 n += LINE_BUFSIZE; /* The other case */
  53         return n - 1;
  54 }
  55
  56 int line_write_room(struct tty_struct *tty)
  57 {
  58         struct line *line = tty->driver_data;
  59         unsigned long flags;
  60         int room;
  61
  62         spin_lock_irqsave(&line->lock, flags);
  63         room = write_room(line);
  64         spin_unlock_irqrestore(&line->lock, flags);
  65
  66         return room;
  67 }
  68
  69 int line_chars_in_buffer(struct tty_struct *tty)
  70 {
  71         struct line *line = tty->driver_data;
  72         unsigned long flags;
  73         int ret;
  74
  75         spin_lock_irqsave(&line->lock, flags);
  76         /* write_room subtracts 1 for the needed NULL, so we readd it.*/
  77         ret = LINE_BUFSIZE - (write_room(line) + 1);
  78         spin_unlock_irqrestore(&line->lock, flags);
  79
  80         return ret;
  81 }
  82
  83 /*
  84  * This copies the content of buf into the circular buffer associated with
  85  * this line.
  86  * The return value is the number of characters actually copied, i.e. the ones
  87  * for which there was space: this function is not supposed to ever flush out
  88  * the circular buffer.
  89  *
  90  * Must be called while holding line->lock!
  91  */
  92 static int buffer_data(struct line *line, const char *buf, int len)
  93 {
  94         int end, room;
  95
  96         if (line->buffer == NULL) {
  97                 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
  98                 if (line->buffer == NULL) {
  99                         printk(KERN_ERR "buffer_data - atomic allocation "
 100                                "failed\n");
 101                         return 0;
 102                 }
 103                 line->head = line->buffer;
 104                 line->tail = line->buffer;
 105         }
 106
 107         room = write_room(line);
 108         len = (len > room) ? room : len;
 109
 110         end = line->buffer + LINE_BUFSIZE - line->tail;
 111
 112         if (len < end) {
 113                 memcpy(line->tail, buf, len);
 114                 line->tail += len;
 115         }
 116         else {
 117                 /* The circular buffer is wrapping */
 118                 memcpy(line->tail, buf, end);
 119                 buf += end;
 120                 memcpy(line->buffer, buf, len - end);
 121                 line->tail = line->buffer + len - end;
 122         }
 123
 124         return len;
 125 }
 126
 127 /*
 128  * Flushes the ring buffer to the output channels. That is, write_chan is
 129  * called, passing it line->head as buffer, and an appropriate count.
 130  *
 131  * On exit, returns 1 when the buffer is empty,
 132  * 0 when the buffer is not empty on exit,
 133  * and -errno when an error occurred.
 134  *
 135  * Must be called while holding line->lock!*/
 136 static int flush_buffer(struct line *line)
 137 {
 138         int n, count;
 139
 140         if ((line->buffer == NULL) || (line->head == line->tail))
 141                 return 1;
 142
 143         if (line->tail < line->head) {
 144                 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
 145                 count = line->buffer + LINE_BUFSIZE - line->head;
 146
 147                 n = write_chan(&line->chan_list, line->head, count,
 148                                line->driver->write_irq);
 149                 if (n < 0)
 150                         return n;
 151                 if (n == count) {
 152                         /*
 153                          * We have flushed from ->head to buffer end, now we
 154                          * must flush only from the beginning to ->tail.
 155                          */
 156                         line->head = line->buffer;
 157                 } else {
 158                         line->head += n;
 159                         return 0;
 160                 }
 161         }
 162
 163         count = line->tail - line->head;
 164         n = write_chan(&line->chan_list, line->head, count,
 165                        line->driver->write_irq);
 166
 167         if (n < 0)
 168                 return n;
 169
 170         line->head += n;
 171         return line->head == line->tail;
 172 }
 173
 174 void line_flush_buffer(struct tty_struct *tty)
 175 {
 176         struct line *line = tty->driver_data;
 177         unsigned long flags;
 178         int err;
 179
 180         spin_lock_irqsave(&line->lock, flags);
 181         err = flush_buffer(line);
 182         spin_unlock_irqrestore(&line->lock, flags);
 183 }
 184
 185 /*
 186  * We map both ->flush_chars and ->put_char (which go in pair) onto
 187  * ->flush_buffer and ->write. Hope it's not that bad.
 188  */
 189 void line_flush_chars(struct tty_struct *tty)
 190 {
 191         line_flush_buffer(tty);
 192 }
 193
 194 void line_put_char(struct tty_struct *tty, unsigned char ch)
 195 {
 196         line_write(tty, &ch, sizeof(ch));
 197 }
 198
 199 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
 200 {
 201         struct line *line = tty->driver_data;
 202         unsigned long flags;
 203         int n, ret = 0;
 204
 205         spin_lock_irqsave(&line->lock, flags);
 206         if (line->head != line->tail)
 207                 ret = buffer_data(line, buf, len);
 208         else {
 209                 n = write_chan(&line->chan_list, buf, len,
 210                                line->driver->write_irq);
 211                 if (n < 0) {
 212                         ret = n;
 213                         goto out_up;
 214                 }
 215
 216                 len -= n;
 217                 ret += n;
 218                 if (len > 0)
 219                         ret += buffer_data(line, buf + n, len);
 220         }
 221 out_up:
 222         spin_unlock_irqrestore(&line->lock, flags);
 223         return ret;
 224 }
 225
 226 void line_set_termios(struct tty_struct *tty, struct ktermios * old)
 227 {
 228         /* nothing */
 229 }
 230
 231 static const struct {
 232         int  cmd;
 233         char *level;
 234         char *name;
 235 } tty_ioctls[] = {
 236         /* don't print these, they flood the log ... */
 237         { TCGETS,      NULL,       "TCGETS"      },
 238         { TCSETS,      NULL,       "TCSETS"      },
 239         { TCSETSW,     NULL,       "TCSETSW"     },
 240         { TCFLSH,      NULL,       "TCFLSH"      },
 241         { TCSBRK,      NULL,       "TCSBRK"      },
 242
 243         /* general tty stuff */
 244         { TCSETSF,     KERN_DEBUG, "TCSETSF"     },
 245         { TCGETA,      KERN_DEBUG, "TCGETA"      },
 246         { TIOCMGET,    KERN_DEBUG, "TIOCMGET"    },
 247         { TCSBRKP,     KERN_DEBUG, "TCSBRKP"     },
 248         { TIOCMSET,    KERN_DEBUG, "TIOCMSET"    },
 249
 250         /* linux-specific ones */
 251         { TIOCLINUX,   KERN_INFO,  "TIOCLINUX"   },
 252         { KDGKBMODE,   KERN_INFO,  "KDGKBMODE"   },
 253         { KDGKBTYPE,   KERN_INFO,  "KDGKBTYPE"   },
 254         { KDSIGACCEPT, KERN_INFO,  "KDSIGACCEPT" },
 255 };
 256
 257 int line_ioctl(struct tty_struct *tty, struct file * file,
 258                unsigned int cmd, unsigned long arg)
 259 {
 260         int ret;
 261         int i;
 262
 263         ret = 0;
 264         switch(cmd) {
 265 #ifdef TIOCGETP
 266         case TIOCGETP:
 267         case TIOCSETP:
 268         case TIOCSETN:
 269 #endif
 270 #ifdef TIOCGETC
 271         case TIOCGETC:
 272         case TIOCSETC:
 273 #endif
 274 #ifdef TIOCGLTC
 275         case TIOCGLTC:
 276         case TIOCSLTC:
 277 #endif
 278         case TCGETS:
 279         case TCSETSF:
 280         case TCSETSW:
 281         case TCSETS:
 282         case TCGETA:
 283         case TCSETAF:
 284         case TCSETAW:
 285         case TCSETA:
 286         case TCXONC:
 287         case TCFLSH:
 288         case TIOCOUTQ:
 289         case TIOCINQ:
 290         case TIOCGLCKTRMIOS:
 291         case TIOCSLCKTRMIOS:
 292         case TIOCPKT:
 293         case TIOCGSOFTCAR:
 294         case TIOCSSOFTCAR:
 295                 return -ENOIOCTLCMD;
 296 #if 0
 297         case TCwhatever:
 298                 /* do something */
 299                 break;
 300 #endif
 301         default:
 302                 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
 303                         if (cmd == tty_ioctls[i].cmd)
 304                                 break;
 305                 if (i == ARRAY_SIZE(tty_ioctls)) {
 306                         printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
 307                                __FUNCTION__, tty->name, cmd);
 308                 }
 309                 ret = -ENOIOCTLCMD;
 310                 break;
 311         }
 312         return ret;
 313 }
 314
 315 void line_throttle(struct tty_struct *tty)
 316 {
 317         struct line *line = tty->driver_data;
 318
 319         deactivate_chan(&line->chan_list, line->driver->read_irq);
 320         line->throttled = 1;
 321 }
 322
 323 void line_unthrottle(struct tty_struct *tty)
 324 {
 325         struct line *line = tty->driver_data;
 326
 327         line->throttled = 0;
 328         chan_interrupt(&line->chan_list, &line->task, tty,
 329                        line->driver->read_irq);
 330
 331         /*
 332          * Maybe there is enough stuff pending that calling the interrupt
 333          * throttles us again.  In this case, line->throttled will be 1
 334          * again and we shouldn't turn the interrupt back on.
 335          */
 336         if (!line->throttled)
 337                 reactivate_chan(&line->chan_list, line->driver->read_irq);
 338 }
 339
 340 static irqreturn_t line_write_interrupt(int irq, void *data)
 341 {
 342         struct chan *chan = data;
 343         struct line *line = chan->line;
 344         struct tty_struct *tty = line->tty;
 345         int err;
 346
 347         /*
 348          * Interrupts are disabled here because we registered the interrupt with
 349          * IRQF_DISABLED (see line_setup_irq).
 350          */
 351
 352         spin_lock(&line->lock);
 353         err = flush_buffer(line);
 354         if (err == 0) {
 355                 return IRQ_NONE;
 356         } else if (err < 0) {
 357                 line->head = line->buffer;
 358                 line->tail = line->buffer;
 359         }
 360         spin_unlock(&line->lock);
 361
 362         if (tty == NULL)
 363                 return IRQ_NONE;
 364
 365         if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
 366            (tty->ldisc.write_wakeup != NULL))
 367                 (tty->ldisc.write_wakeup)(tty);
 368
 369         /*
 370          * BLOCKING mode
 371          * In blocking mode, everything sleeps on tty->write_wait.
 372          * Sleeping in the console driver would break non-blocking
 373          * writes.
 374          */
 375
 376         if (waitqueue_active(&tty->write_wait))
 377                 wake_up_interruptible(&tty->write_wait);
 378         return IRQ_HANDLED;
 379 }
 380
 381 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
 382 {
 383         const struct line_driver *driver = line->driver;
 384         int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
 385
 386         if (input)
 387                 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
 388                                        line_interrupt, flags,
 389                                        driver->read_irq_name, data);
 390         if (err)
 391                 return err;
 392         if (output)
 393                 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
 394                                         line_write_interrupt, flags,
 395                                         driver->write_irq_name, data);
 396         line->have_irq = 1;
 397         return err;
 398 }
 399
 400 /*
 401  * Normally, a driver like this can rely mostly on the tty layer
 402  * locking, particularly when it comes to the driver structure.
 403  * However, in this case, mconsole requests can come in "from the
 404  * side", and race with opens and closes.
 405  *
 406  * mconsole config requests will want to be sure the device isn't in
 407  * use, and get_config, open, and close will want a stable
 408  * configuration.  The checking and modification of the configuration
 409  * is done under a spinlock.  Checking whether the device is in use is
 410  * line->tty->count > 1, also under the spinlock.
 411  *
 412  * tty->count serves to decide whether the device should be enabled or
 413  * disabled on the host.  If it's equal to 1, then we are doing the
 414  * first open or last close.  Otherwise, open and close just return.
 415  */
 416
 417 int line_open(struct line *lines, struct tty_struct *tty)
 418 {
 419         struct line *line = &lines[tty->index];
 420         int err = -ENODEV;
 421
 422         spin_lock(&line->count_lock);
 423         if (!line->valid)
 424                 goto out_unlock;
 425
 426         err = 0;
 427         if (tty->count > 1)
 428                 goto out_unlock;
 429
 430         spin_unlock(&line->count_lock);
 431
 432         tty->driver_data = line;
 433         line->tty = tty;
 434
 435         err = enable_chan(line);
 436         if (err)
 437                 return err;
 438
 439         INIT_DELAYED_WORK(&line->task, line_timer_cb);
 440
 441         if (!line->sigio) {
 442                 chan_enable_winch(&line->chan_list, tty);
 443                 line->sigio = 1;
 444         }
 445
 446         chan_window_size(&line->chan_list, &tty->winsize.ws_row,
 447                          &tty->winsize.ws_col);
 448
 449         return err;
 450
 451 out_unlock:
 452         spin_unlock(&line->count_lock);
 453         return err;
 454 }
 455
 456 static void unregister_winch(struct tty_struct *tty);
 457
 458 void line_close(struct tty_struct *tty, struct file * filp)
 459 {
 460         struct line *line = tty->driver_data;
 461
 462         /*
 463          * If line_open fails (and tty->driver_data is never set),
 464          * tty_open will call line_close.  So just return in this case.
 465          */
 466         if (line == NULL)
 467                 return;
 468
 469         /* We ignore the error anyway! */
 470         flush_buffer(line);
 471
 472         spin_lock(&line->count_lock);
 473         if (!line->valid)
 474                 goto out_unlock;
 475
 476         if (tty->count > 1)
 477                 goto out_unlock;
 478
 479         spin_unlock(&line->count_lock);
 480
 481         line->tty = NULL;
 482         tty->driver_data = NULL;
 483
 484         if (line->sigio) {
 485                 unregister_winch(tty);
 486                 line->sigio = 0;
 487         }
 488
 489         return;
 490
 491 out_unlock:
 492         spin_unlock(&line->count_lock);
 493 }
 494
 495 void close_lines(struct line *lines, int nlines)
 496 {
 497         int i;
 498
 499         for(i = 0; i < nlines; i++)
 500                 close_chan(&lines[i].chan_list, 0);
 501 }
 502
 503 static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
 504                           char **error_out)
 505 {
 506         struct line *line = &lines[n];
 507         int err = -EINVAL;
 508
 509         spin_lock(&line->count_lock);
 510
 511         if (line->tty != NULL) {
 512                 *error_out = "Device is already open";
 513                 goto out;
 514         }
 515
 516         if (line->init_pri <= init_prio) {
 517                 line->init_pri = init_prio;
 518                 if (!strcmp(init, "none"))
 519                         line->valid = 0;
 520                 else {
 521                         line->init_str = init;
 522                         line->valid = 1;
 523                 }
 524         }
 525         err = 0;
 526 out:
 527         spin_unlock(&line->count_lock);
 528         return err;
 529 }
 530
 531 /*
 532  * Common setup code for both startup command line and mconsole initialization.
 533  * @lines contains the array (of size @num) to modify;
 534  * @init is the setup string;
 535  * @error_out is an error string in the case of failure;
 536  */
 537
 538 int line_setup(struct line *lines, unsigned int num, char *init,
 539                char **error_out)
 540 {
 541         int i, n, err;
 542         char *end;
 543
 544         if (*init == '=') {
 545                 /*
 546                  * We said con=/ssl= instead of con#=, so we are configuring all
 547                  * consoles at once.
 548                  */
 549                 n = -1;
 550         }
 551         else {
 552                 n = simple_strtoul(init, &end, 0);
 553                 if (*end != '=') {
 554                         *error_out = "Couldn't parse device number";
 555                         return -EINVAL;
 556                 }
 557                 init = end;
 558         }
 559         init++;
 560
 561         if (n >= (signed int) num) {
 562                 *error_out = "Device number out of range";
 563                 return -EINVAL;
 564         }
 565         else if (n >= 0) {
 566                 err = setup_one_line(lines, n, init, INIT_ONE, error_out);
 567                 if (err)
 568                         return err;
 569         }
 570         else {
 571                 for(i = 0; i < num; i++) {
 572                         err = setup_one_line(lines, i, init, INIT_ALL,
 573                                              error_out);
 574                         if (err)
 575                                 return err;
 576                 }
 577         }
 578         return n == -1 ? num : n;
 579 }
 580
 581 int line_config(struct line *lines, unsigned int num, char *str,
 582                 const struct chan_opts *opts, char **error_out)
 583 {
 584         struct line *line;
 585         char *new;
 586         int n;
 587
 588         if (*str == '=') {
 589                 *error_out = "Can't configure all devices from mconsole";
 590                 return -EINVAL;
 591         }
 592
 593         new = kstrdup(str, GFP_KERNEL);
 594         if (new == NULL) {
 595                 *error_out = "Failed to allocate memory";
 596                 return -ENOMEM;
 597         }
 598         n = line_setup(lines, num, new, error_out);
 599         if (n < 0)
 600                 return n;
 601
 602         line = &lines[n];
 603         return parse_chan_pair(line->init_str, line, n, opts, error_out);
 604 }
 605
 606 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
 607                     int size, char **error_out)
 608 {
 609         struct line *line;
 610         char *end;
 611         int dev, n = 0;
 612
 613         dev = simple_strtoul(name, &end, 0);
 614         if ((*end != '\0') || (end == name)) {
 615                 *error_out = "line_get_config failed to parse device number";
 616                 return 0;
 617         }
 618
 619         if ((dev < 0) || (dev >= num)) {
 620                 *error_out = "device number out of range";
 621                 return 0;
 622         }
 623
 624         line = &lines[dev];
 625
 626         spin_lock(&line->count_lock);
 627         if (!line->valid)
 628                 CONFIG_CHUNK(str, size, n, "none", 1);
 629         else if (line->tty == NULL)
 630                 CONFIG_CHUNK(str, size, n, line->init_str, 1);
 631         else n = chan_config_string(&line->chan_list, str, size, error_out);
 632         spin_unlock(&line->count_lock);
 633
 634         return n;
 635 }
 636
 637 int line_id(char **str, int *start_out, int *end_out)
 638 {
 639         char *end;
 640         int n;
 641
 642         n = simple_strtoul(*str, &end, 0);
 643         if ((*end != '\0') || (end == *str))
 644                 return -1;
 645
 646         *str = end;
 647         *start_out = n;
 648         *end_out = n;
 649         return n;
 650 }
 651
 652 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
 653 {
 654         int err;
 655         char config[sizeof("conxxxx=none\0")];
 656
 657         sprintf(config, "%d=none", n);
 658         err = line_setup(lines, num, config, error_out);
 659         if (err >= 0)
 660                 err = 0;
 661         return err;
 662 }
 663
 664 struct tty_driver *register_lines(struct line_driver *line_driver,
 665                                   const struct tty_operations *ops,
 666                                   struct line *lines, int nlines)
 667 {
 668         int i;
 669         struct tty_driver *driver = alloc_tty_driver(nlines);
 670
 671         if (!driver)
 672                 return NULL;
 673
 674         driver->driver_name = line_driver->name;
 675         driver->name = line_driver->device_name;
 676         driver->major = line_driver->major;
 677         driver->minor_start = line_driver->minor_start;
 678         driver->type = line_driver->type;
 679         driver->subtype = line_driver->subtype;
 680         driver->flags = TTY_DRIVER_REAL_RAW;
 681         driver->init_termios = tty_std_termios;
 682         tty_set_operations(driver, ops);
 683
 684         if (tty_register_driver(driver)) {
 685                 printk(KERN_ERR "register_lines : can't register %s driver\n",
 686                        line_driver->name);
 687                 put_tty_driver(driver);
 688                 return NULL;
 689         }
 690
 691         for(i = 0; i < nlines; i++) {
 692                 if (!lines[i].valid)
 693                         tty_unregister_device(driver, i);
 694         }
 695
 696         mconsole_register_dev(&line_driver->mc);
 697         return driver;
 698 }
 699
 700 static DEFINE_SPINLOCK(winch_handler_lock);
 701 static LIST_HEAD(winch_handlers);
 702
 703 void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
 704 {
 705         struct line *line;
 706         char *error;
 707         int i;
 708
 709         for(i = 0; i < nlines; i++) {
 710                 line = &lines[i];
 711                 INIT_LIST_HEAD(&line->chan_list);
 712
 713                 if (line->init_str == NULL)
 714                         continue;
 715
 716                 line->init_str = kstrdup(line->init_str, GFP_KERNEL);
 717                 if (line->init_str == NULL)
 718                         printk(KERN_ERR "lines_init - kstrdup returned NULL\n");
 719
 720                 if (parse_chan_pair(line->init_str, line, i, opts, &error)) {
 721                         printk(KERN_ERR "parse_chan_pair failed for "
 722                                "device %d : %s\n", i, error);
 723                         line->valid = 0;
 724                 }
 725         }
 726 }
 727
 728 struct winch {
 729         struct list_head list;
 730         int fd;
 731         int tty_fd;
 732         int pid;
 733         struct tty_struct *tty;
 734         unsigned long stack;
 735 };
 736
 737 static void free_winch(struct winch *winch, int free_irq_ok)
 738 {
 739         list_del(&winch->list);
 740
 741         if (winch->pid != -1)
 742                 os_kill_process(winch->pid, 1);
 743         if (winch->fd != -1)
 744                 os_close_file(winch->fd);
 745         if (winch->stack != 0)
 746                 free_stack(winch->stack, 0);
 747         if (free_irq_ok)
 748                 free_irq(WINCH_IRQ, winch);
 749         kfree(winch);
 750 }
 751
 752 static irqreturn_t winch_interrupt(int irq, void *data)
 753 {
 754         struct winch *winch = data;
 755         struct tty_struct *tty;
 756         struct line *line;
 757         int err;
 758         char c;
 759
 760         if (winch->fd != -1) {
 761                 err = generic_read(winch->fd, &c, NULL);
 762                 if (err < 0) {
 763                         if (err != -EAGAIN) {
 764                                 printk(KERN_ERR "winch_interrupt : "
 765                                        "read failed, errno = %d\n", -err);
 766                                 printk(KERN_ERR "fd %d is losing SIGWINCH "
 767                                        "support\n", winch->tty_fd);
 768                                 free_winch(winch, 0);
 769                                 return IRQ_HANDLED;
 770                         }
 771                         goto out;
 772                 }
 773         }
 774         tty = winch->tty;
 775         if (tty != NULL) {
 776                 line = tty->driver_data;
 777                 if (line != NULL) {
 778                         chan_window_size(&line->chan_list, &tty->winsize.ws_row,
 779                                          &tty->winsize.ws_col);
 780                         kill_pgrp(tty->pgrp, SIGWINCH, 1);
 781                 }
 782         }
 783  out:
 784         if (winch->fd != -1)
 785                 reactivate_fd(winch->fd, WINCH_IRQ);
 786         return IRQ_HANDLED;
 787 }
 788
 789 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
 790                         unsigned long stack)
 791 {
 792         struct winch *winch;
 793
 794         winch = kmalloc(sizeof(*winch), GFP_KERNEL);
 795         if (winch == NULL) {
 796                 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
 797                 goto cleanup;
 798         }
 799
 800         *winch = ((struct winch) { .list        = LIST_HEAD_INIT(winch->list),
 801                                    .fd          = fd,
 802                                    .tty_fd      = tty_fd,
 803                                    .pid         = pid,
 804                                    .tty         = tty,
 805                                    .stack       = stack });
 806
 807         if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
 808                            IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 809                            "winch", winch) < 0) {
 810                 printk(KERN_ERR "register_winch_irq - failed to register "
 811                        "IRQ\n");
 812                 goto out_free;
 813         }
 814
 815         spin_lock(&winch_handler_lock);
 816         list_add(&winch->list, &winch_handlers);
 817         spin_unlock(&winch_handler_lock);
 818
 819         return;
 820
 821  out_free:
 822         kfree(winch);
 823  cleanup:
 824         os_kill_process(pid, 1);
 825         os_close_file(fd);
 826         if (stack != 0)
 827                 free_stack(stack, 0);
 828 }
 829
 830 static void unregister_winch(struct tty_struct *tty)
 831 {
 832         struct list_head *ele;
 833         struct winch *winch;
 834
 835         spin_lock(&winch_handler_lock);
 836
 837         list_for_each(ele, &winch_handlers) {
 838                 winch = list_entry(ele, struct winch, list);
 839                 if (winch->tty == tty) {
 840                         free_winch(winch, 1);
 841                         break;
 842                 }
 843         }
 844         spin_unlock(&winch_handler_lock);
 845 }
 846
 847 static void winch_cleanup(void)
 848 {
 849         struct list_head *ele, *next;
 850         struct winch *winch;
 851
 852         spin_lock(&winch_handler_lock);
 853
 854         list_for_each_safe(ele, next, &winch_handlers) {
 855                 winch = list_entry(ele, struct winch, list);
 856                 free_winch(winch, 1);
 857         }
 858
 859         spin_unlock(&winch_handler_lock);
 860 }
 861 __uml_exitcall(winch_cleanup);
 862
 863 char *add_xterm_umid(char *base)
 864 {
 865         char *umid, *title;
 866         int len;
 867
 868         umid = get_umid();
 869         if (*umid == '\0')
 870                 return base;
 871
 872         len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
 873         title = kmalloc(len, GFP_KERNEL);
 874         if (title == NULL) {
 875                 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
 876                 return base;
 877         }
 878
 879         snprintf(title, len, "%s (%s)", base, umid);
 880         return title;
 881 }