git.oblomov.eu Git - linux-2.6/blob - arch/um/drivers/line.c

   1 /*
   2  * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/sched.h"
   7 #include "linux/slab.h"
   8 #include "linux/list.h"
   9 #include "linux/kd.h"
  10 #include "linux/interrupt.h"
  11 #include "asm/uaccess.h"
  12 #include "chan_kern.h"
  13 #include "irq_user.h"
  14 #include "line.h"
  15 #include "kern.h"
  16 #include "user_util.h"
  17 #include "kern_util.h"
  18 #include "os.h"
  19 #include "irq_kern.h"
  20
  21 #define LINE_BUFSIZE 4096
  22
  23 static irqreturn_t line_interrupt(int irq, void *data)
  24 {
  25         struct chan *chan = data;
  26         struct line *line = chan->line;
  27         struct tty_struct *tty = line->tty;
  28
  29         if (line)
  30                 chan_interrupt(&line->chan_list, &line->task, tty, irq);
  31         return IRQ_HANDLED;
  32 }
  33
  34 static void line_timer_cb(void *arg)
  35 {
  36         struct line *line = arg;
  37
  38         if(!line->throttled)
  39                 chan_interrupt(&line->chan_list, &line->task, line->tty,
  40                                line->driver->read_irq);
  41 }
  42
  43 /* Returns the free space inside the ring buffer of this line.
  44  *
  45  * Should be called while holding line->lock (this does not modify datas).
  46  */
  47 static int write_room(struct line *line)
  48 {
  49         int n;
  50
  51         if (line->buffer == NULL)
  52                 return LINE_BUFSIZE - 1;
  53
  54         /* This is for the case where the buffer is wrapped! */
  55         n = line->head - line->tail;
  56
  57         if (n <= 0)
  58                 n = LINE_BUFSIZE + n; /* The other case */
  59         return n - 1;
  60 }
  61
  62 int line_write_room(struct tty_struct *tty)
  63 {
  64         struct line *line = tty->driver_data;
  65         unsigned long flags;
  66         int room;
  67
  68         if (tty->stopped)
  69                 return 0;
  70
  71         spin_lock_irqsave(&line->lock, flags);
  72         room = write_room(line);
  73         spin_unlock_irqrestore(&line->lock, flags);
  74
  75         /*XXX: Warning to remove */
  76         if (0 == room)
  77                 printk(KERN_DEBUG "%s: %s: no room left in buffer\n",
  78                        __FUNCTION__,tty->name);
  79         return room;
  80 }
  81
  82 int line_chars_in_buffer(struct tty_struct *tty)
  83 {
  84         struct line *line = tty->driver_data;
  85         unsigned long flags;
  86         int ret;
  87
  88         spin_lock_irqsave(&line->lock, flags);
  89
  90         /*write_room subtracts 1 for the needed NULL, so we readd it.*/
  91         ret = LINE_BUFSIZE - (write_room(line) + 1);
  92         spin_unlock_irqrestore(&line->lock, flags);
  93
  94         return ret;
  95 }
  96
  97 /*
  98  * This copies the content of buf into the circular buffer associated with
  99  * this line.
 100  * The return value is the number of characters actually copied, i.e. the ones
 101  * for which there was space: this function is not supposed to ever flush out
 102  * the circular buffer.
 103  *
 104  * Must be called while holding line->lock!
 105  */
 106 static int buffer_data(struct line *line, const char *buf, int len)
 107 {
 108         int end, room;
 109
 110         if(line->buffer == NULL){
 111                 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
 112                 if (line->buffer == NULL) {
 113                         printk("buffer_data - atomic allocation failed\n");
 114                         return(0);
 115                 }
 116                 line->head = line->buffer;
 117                 line->tail = line->buffer;
 118         }
 119
 120         room = write_room(line);
 121         len = (len > room) ? room : len;
 122
 123         end = line->buffer + LINE_BUFSIZE - line->tail;
 124
 125         if (len < end){
 126                 memcpy(line->tail, buf, len);
 127                 line->tail += len;
 128         }
 129         else {
 130                 /* The circular buffer is wrapping */
 131                 memcpy(line->tail, buf, end);
 132                 buf += end;
 133                 memcpy(line->buffer, buf, len - end);
 134                 line->tail = line->buffer + len - end;
 135         }
 136
 137         return len;
 138 }
 139
 140 /*
 141  * Flushes the ring buffer to the output channels. That is, write_chan is
 142  * called, passing it line->head as buffer, and an appropriate count.
 143  *
 144  * On exit, returns 1 when the buffer is empty,
 145  * 0 when the buffer is not empty on exit,
 146  * and -errno when an error occurred.
 147  *
 148  * Must be called while holding line->lock!*/
 149 static int flush_buffer(struct line *line)
 150 {
 151         int n, count;
 152
 153         if ((line->buffer == NULL) || (line->head == line->tail))
 154                 return 1;
 155
 156         if (line->tail < line->head) {
 157                 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
 158                 count = line->buffer + LINE_BUFSIZE - line->head;
 159
 160                 n = write_chan(&line->chan_list, line->head, count,
 161                                line->driver->write_irq);
 162                 if (n < 0)
 163                         return n;
 164                 if (n == count) {
 165                         /* We have flushed from ->head to buffer end, now we
 166                          * must flush only from the beginning to ->tail.*/
 167                         line->head = line->buffer;
 168                 } else {
 169                         line->head += n;
 170                         return 0;
 171                 }
 172         }
 173
 174         count = line->tail - line->head;
 175         n = write_chan(&line->chan_list, line->head, count,
 176                        line->driver->write_irq);
 177
 178         if(n < 0)
 179                 return n;
 180
 181         line->head += n;
 182         return line->head == line->tail;
 183 }
 184
 185 void line_flush_buffer(struct tty_struct *tty)
 186 {
 187         struct line *line = tty->driver_data;
 188         unsigned long flags;
 189         int err;
 190
 191         /*XXX: copied from line_write, verify if it is correct!*/
 192         if(tty->stopped)
 193                 return;
 194                 //return 0;
 195
 196         spin_lock_irqsave(&line->lock, flags);
 197         err = flush_buffer(line);
 198         /*if (err == 1)
 199                 err = 0;*/
 200         spin_unlock_irqrestore(&line->lock, flags);
 201         //return err;
 202 }
 203
 204 /* We map both ->flush_chars and ->put_char (which go in pair) onto ->flush_buffer
 205  * and ->write. Hope it's not that bad.*/
 206 void line_flush_chars(struct tty_struct *tty)
 207 {
 208         line_flush_buffer(tty);
 209 }
 210
 211 void line_put_char(struct tty_struct *tty, unsigned char ch)
 212 {
 213         line_write(tty, &ch, sizeof(ch));
 214 }
 215
 216 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
 217 {
 218         struct line *line = tty->driver_data;
 219         unsigned long flags;
 220         int n, err, ret = 0;
 221
 222         if(tty->stopped)
 223                 return 0;
 224
 225         spin_lock_irqsave(&line->lock, flags);
 226         if (line->head != line->tail) {
 227                 ret = buffer_data(line, buf, len);
 228                 err = flush_buffer(line);
 229                 if (err <= 0 && (err != -EAGAIN || !ret))
 230                         ret = err;
 231         } else {
 232                 n = write_chan(&line->chan_list, buf, len,
 233                                line->driver->write_irq);
 234                 if (n < 0) {
 235                         ret = n;
 236                         goto out_up;
 237                 }
 238
 239                 len -= n;
 240                 ret += n;
 241                 if (len > 0)
 242                         ret += buffer_data(line, buf + n, len);
 243         }
 244 out_up:
 245         spin_unlock_irqrestore(&line->lock, flags);
 246         return ret;
 247 }
 248
 249 void line_set_termios(struct tty_struct *tty, struct termios * old)
 250 {
 251         /* nothing */
 252 }
 253
 254 static const struct {
 255         int  cmd;
 256         char *level;
 257         char *name;
 258 } tty_ioctls[] = {
 259         /* don't print these, they flood the log ... */
 260         { TCGETS,      NULL,       "TCGETS"      },
 261         { TCSETS,      NULL,       "TCSETS"      },
 262         { TCSETSW,     NULL,       "TCSETSW"     },
 263         { TCFLSH,      NULL,       "TCFLSH"      },
 264         { TCSBRK,      NULL,       "TCSBRK"      },
 265
 266         /* general tty stuff */
 267         { TCSETSF,     KERN_DEBUG, "TCSETSF"     },
 268         { TCGETA,      KERN_DEBUG, "TCGETA"      },
 269         { TIOCMGET,    KERN_DEBUG, "TIOCMGET"    },
 270         { TCSBRKP,     KERN_DEBUG, "TCSBRKP"     },
 271         { TIOCMSET,    KERN_DEBUG, "TIOCMSET"    },
 272
 273         /* linux-specific ones */
 274         { TIOCLINUX,   KERN_INFO,  "TIOCLINUX"   },
 275         { KDGKBMODE,   KERN_INFO,  "KDGKBMODE"   },
 276         { KDGKBTYPE,   KERN_INFO,  "KDGKBTYPE"   },
 277         { KDSIGACCEPT, KERN_INFO,  "KDSIGACCEPT" },
 278 };
 279
 280 int line_ioctl(struct tty_struct *tty, struct file * file,
 281                unsigned int cmd, unsigned long arg)
 282 {
 283         int ret;
 284         int i;
 285
 286         ret = 0;
 287         switch(cmd) {
 288 #ifdef TIOCGETP
 289         case TIOCGETP:
 290         case TIOCSETP:
 291         case TIOCSETN:
 292 #endif
 293 #ifdef TIOCGETC
 294         case TIOCGETC:
 295         case TIOCSETC:
 296 #endif
 297 #ifdef TIOCGLTC
 298         case TIOCGLTC:
 299         case TIOCSLTC:
 300 #endif
 301         case TCGETS:
 302         case TCSETSF:
 303         case TCSETSW:
 304         case TCSETS:
 305         case TCGETA:
 306         case TCSETAF:
 307         case TCSETAW:
 308         case TCSETA:
 309         case TCXONC:
 310         case TCFLSH:
 311         case TIOCOUTQ:
 312         case TIOCINQ:
 313         case TIOCGLCKTRMIOS:
 314         case TIOCSLCKTRMIOS:
 315         case TIOCPKT:
 316         case TIOCGSOFTCAR:
 317         case TIOCSSOFTCAR:
 318                 return -ENOIOCTLCMD;
 319 #if 0
 320         case TCwhatever:
 321                 /* do something */
 322                 break;
 323 #endif
 324         default:
 325                 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
 326                         if (cmd == tty_ioctls[i].cmd)
 327                                 break;
 328                 if (i < ARRAY_SIZE(tty_ioctls)) {
 329                         if (NULL != tty_ioctls[i].level)
 330                                 printk("%s%s: %s: ioctl %s called\n",
 331                                        tty_ioctls[i].level, __FUNCTION__,
 332                                        tty->name, tty_ioctls[i].name);
 333                 } else {
 334                         printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
 335                                __FUNCTION__, tty->name, cmd);
 336                 }
 337                 ret = -ENOIOCTLCMD;
 338                 break;
 339         }
 340         return ret;
 341 }
 342
 343 void line_throttle(struct tty_struct *tty)
 344 {
 345         struct line *line = tty->driver_data;
 346
 347         deactivate_chan(&line->chan_list, line->driver->read_irq);
 348         line->throttled = 1;
 349 }
 350
 351 void line_unthrottle(struct tty_struct *tty)
 352 {
 353         struct line *line = tty->driver_data;
 354
 355         line->throttled = 0;
 356         chan_interrupt(&line->chan_list, &line->task, tty,
 357                        line->driver->read_irq);
 358
 359         /* Maybe there is enough stuff pending that calling the interrupt
 360          * throttles us again.  In this case, line->throttled will be 1
 361          * again and we shouldn't turn the interrupt back on.
 362          */
 363         if(!line->throttled)
 364                 reactivate_chan(&line->chan_list, line->driver->read_irq);
 365 }
 366
 367 static irqreturn_t line_write_interrupt(int irq, void *data)
 368 {
 369         struct chan *chan = data;
 370         struct line *line = chan->line;
 371         struct tty_struct *tty = line->tty;
 372         int err;
 373
 374         /* Interrupts are enabled here because we registered the interrupt with
 375          * IRQF_DISABLED (see line_setup_irq).*/
 376
 377         spin_lock_irq(&line->lock);
 378         err = flush_buffer(line);
 379         if (err == 0) {
 380                 return IRQ_NONE;
 381         } else if(err < 0) {
 382                 line->head = line->buffer;
 383                 line->tail = line->buffer;
 384         }
 385         spin_unlock_irq(&line->lock);
 386
 387         if(tty == NULL)
 388                 return IRQ_NONE;
 389
 390         if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
 391            (tty->ldisc.write_wakeup != NULL))
 392                 (tty->ldisc.write_wakeup)(tty);
 393
 394         /* BLOCKING mode
 395          * In blocking mode, everything sleeps on tty->write_wait.
 396          * Sleeping in the console driver would break non-blocking
 397          * writes.
 398          */
 399
 400         if (waitqueue_active(&tty->write_wait))
 401                 wake_up_interruptible(&tty->write_wait);
 402         return IRQ_HANDLED;
 403 }
 404
 405 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
 406 {
 407         const struct line_driver *driver = line->driver;
 408         int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
 409
 410         if (input)
 411                 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
 412                                        line_interrupt, flags,
 413                                        driver->read_irq_name, data);
 414         if (err)
 415                 return err;
 416         if (output)
 417                 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
 418                                         line_write_interrupt, flags,
 419                                         driver->write_irq_name, data);
 420         line->have_irq = 1;
 421         return err;
 422 }
 423
 424 int line_open(struct line *lines, struct tty_struct *tty)
 425 {
 426         struct line *line;
 427         int err = -ENODEV;
 428
 429         line = &lines[tty->index];
 430         tty->driver_data = line;
 431
 432         /* The IRQ which takes this lock is not yet enabled and won't be run
 433          * before the end, so we don't need to use spin_lock_irq.*/
 434         spin_lock(&line->lock);
 435
 436         tty->driver_data = line;
 437         line->tty = tty;
 438         if(!line->valid)
 439                 goto out;
 440
 441         if(tty->count == 1){
 442                 /* Here the device is opened, if necessary, and interrupt
 443                  * is registered.
 444                  */
 445                 enable_chan(line);
 446                 INIT_WORK(&line->task, line_timer_cb, line);
 447
 448                 if(!line->sigio){
 449                         chan_enable_winch(&line->chan_list, tty);
 450                         line->sigio = 1;
 451                 }
 452
 453                 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
 454                                  &tty->winsize.ws_col);
 455         }
 456
 457         err = 0;
 458 out:
 459         spin_unlock(&line->lock);
 460         return err;
 461 }
 462
 463 static void unregister_winch(struct tty_struct *tty);
 464
 465 void line_close(struct tty_struct *tty, struct file * filp)
 466 {
 467         struct line *line = tty->driver_data;
 468
 469         /* XXX: I assume this should be called in process context, not with
 470          *  interrupts disabled!
 471          */
 472         spin_lock_irq(&line->lock);
 473
 474         /* We ignore the error anyway! */
 475         flush_buffer(line);
 476
 477         if(tty->count == 1){
 478                 line->tty = NULL;
 479                 tty->driver_data = NULL;
 480
 481                 if(line->sigio){
 482                         unregister_winch(tty);
 483                         line->sigio = 0;
 484                 }
 485         }
 486
 487         spin_unlock_irq(&line->lock);
 488 }
 489
 490 void close_lines(struct line *lines, int nlines)
 491 {
 492         int i;
 493
 494         for(i = 0; i < nlines; i++)
 495                 close_chan(&lines[i].chan_list, 0);
 496 }
 497
 498 /* Common setup code for both startup command line and mconsole initialization.
 499  * @lines contains the array (of size @num) to modify;
 500  * @init is the setup string;
 501  */
 502
 503 int line_setup(struct line *lines, unsigned int num, char *init)
 504 {
 505         int i, n;
 506         char *end;
 507
 508         if(*init == '=') {
 509                 /* We said con=/ssl= instead of con#=, so we are configuring all
 510                  * consoles at once.*/
 511                 n = -1;
 512         }
 513         else {
 514                 n = simple_strtoul(init, &end, 0);
 515                 if(*end != '='){
 516                         printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
 517                                init);
 518                         return 0;
 519                 }
 520                 init = end;
 521         }
 522         init++;
 523
 524         if (n >= (signed int) num) {
 525                 printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
 526                        n, num - 1);
 527                 return 0;
 528         }
 529         else if (n >= 0){
 530                 if (lines[n].tty != NULL) {
 531                         printk("line_setup - device %d is open\n", n);
 532                         return 0;
 533                 }
 534                 if (lines[n].init_pri <= INIT_ONE){
 535                         lines[n].init_pri = INIT_ONE;
 536                         if (!strcmp(init, "none"))
 537                                 lines[n].valid = 0;
 538                         else {
 539                                 lines[n].init_str = init;
 540                                 lines[n].valid = 1;
 541                         }
 542                 }
 543         }
 544         else {
 545                 for(i = 0; i < num; i++){
 546                         if(lines[i].init_pri <= INIT_ALL){
 547                                 lines[i].init_pri = INIT_ALL;
 548                                 if(!strcmp(init, "none")) lines[i].valid = 0;
 549                                 else {
 550                                         lines[i].init_str = init;
 551                                         lines[i].valid = 1;
 552                                 }
 553                         }
 554                 }
 555         }
 556         return n == -1 ? num : n;
 557 }
 558
 559 int line_config(struct line *lines, unsigned int num, char *str,
 560                 const struct chan_opts *opts)
 561 {
 562         struct line *line;
 563         char *new;
 564         int n;
 565
 566         if(*str == '='){
 567                 printk("line_config - can't configure all devices from "
 568                        "mconsole\n");
 569                 return 1;
 570         }
 571
 572         new = kstrdup(str, GFP_KERNEL);
 573         if(new == NULL){
 574                 printk("line_config - kstrdup failed\n");
 575                 return 1;
 576         }
 577         n = line_setup(lines, num, new);
 578         if(n < 0)
 579                 return 1;
 580
 581         line = &lines[n];
 582         return parse_chan_pair(line->init_str, line, n, opts);
 583 }
 584
 585 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
 586                     int size, char **error_out)
 587 {
 588         struct line *line;
 589         char *end;
 590         int dev, n = 0;
 591
 592         dev = simple_strtoul(name, &end, 0);
 593         if((*end != '\0') || (end == name)){
 594                 *error_out = "line_get_config failed to parse device number";
 595                 return 0;
 596         }
 597
 598         if((dev < 0) || (dev >= num)){
 599                 *error_out = "device number out of range";
 600                 return 0;
 601         }
 602
 603         line = &lines[dev];
 604
 605         spin_lock(&line->lock);
 606         if(!line->valid)
 607                 CONFIG_CHUNK(str, size, n, "none", 1);
 608         else if(line->tty == NULL)
 609                 CONFIG_CHUNK(str, size, n, line->init_str, 1);
 610         else n = chan_config_string(&line->chan_list, str, size, error_out);
 611         spin_unlock(&line->lock);
 612
 613         return n;
 614 }
 615
 616 int line_id(char **str, int *start_out, int *end_out)
 617 {
 618         char *end;
 619         int n;
 620
 621         n = simple_strtoul(*str, &end, 0);
 622         if((*end != '\0') || (end == *str))
 623                 return -1;
 624
 625         *str = end;
 626         *start_out = n;
 627         *end_out = n;
 628         return n;
 629 }
 630
 631 int line_remove(struct line *lines, unsigned int num, int n)
 632 {
 633         int err;
 634         char config[sizeof("conxxxx=none\0")];
 635
 636         sprintf(config, "%d=none", n);
 637         err = line_setup(lines, num, config);
 638         if(err >= 0)
 639                 err = 0;
 640         return err;
 641 }
 642
 643 struct tty_driver *line_register_devfs(struct lines *set,
 644                                        struct line_driver *line_driver,
 645                                        const struct tty_operations *ops,
 646                                        struct line *lines, int nlines)
 647 {
 648         int i;
 649         struct tty_driver *driver = alloc_tty_driver(nlines);
 650
 651         if (!driver)
 652                 return NULL;
 653
 654         driver->driver_name = line_driver->name;
 655         driver->name = line_driver->device_name;
 656         driver->major = line_driver->major;
 657         driver->minor_start = line_driver->minor_start;
 658         driver->type = line_driver->type;
 659         driver->subtype = line_driver->subtype;
 660         driver->flags = TTY_DRIVER_REAL_RAW;
 661         driver->init_termios = tty_std_termios;
 662         tty_set_operations(driver, ops);
 663
 664         if (tty_register_driver(driver)) {
 665                 printk("%s: can't register %s driver\n",
 666                        __FUNCTION__,line_driver->name);
 667                 put_tty_driver(driver);
 668                 return NULL;
 669         }
 670
 671         for(i = 0; i < nlines; i++){
 672                 if(!lines[i].valid)
 673                         tty_unregister_device(driver, i);
 674         }
 675
 676         mconsole_register_dev(&line_driver->mc);
 677         return driver;
 678 }
 679
 680 static DEFINE_SPINLOCK(winch_handler_lock);
 681 static LIST_HEAD(winch_handlers);
 682
 683 void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
 684 {
 685         struct line *line;
 686         int i;
 687
 688         for(i = 0; i < nlines; i++){
 689                 line = &lines[i];
 690                 INIT_LIST_HEAD(&line->chan_list);
 691
 692                 if(line->init_str == NULL)
 693                         continue;
 694
 695                 line->init_str = kstrdup(line->init_str, GFP_KERNEL);
 696                 if(line->init_str == NULL)
 697                         printk("lines_init - kstrdup returned NULL\n");
 698
 699                 if(parse_chan_pair(line->init_str, line, i, opts)){
 700                         printk("parse_chan_pair failed for device %d\n", i);
 701                         line->valid = 0;
 702                 }
 703         }
 704 }
 705
 706 struct winch {
 707         struct list_head list;
 708         int fd;
 709         int tty_fd;
 710         int pid;
 711         struct tty_struct *tty;
 712 };
 713
 714 static irqreturn_t winch_interrupt(int irq, void *data)
 715 {
 716         struct winch *winch = data;
 717         struct tty_struct *tty;
 718         struct line *line;
 719         int err;
 720         char c;
 721
 722         if(winch->fd != -1){
 723                 err = generic_read(winch->fd, &c, NULL);
 724                 if(err < 0){
 725                         if(err != -EAGAIN){
 726                                 printk("winch_interrupt : read failed, "
 727                                        "errno = %d\n", -err);
 728                                 printk("fd %d is losing SIGWINCH support\n",
 729                                        winch->tty_fd);
 730                                 return IRQ_HANDLED;
 731                         }
 732                         goto out;
 733                 }
 734         }
 735         tty  = winch->tty;
 736         if (tty != NULL) {
 737                 line = tty->driver_data;
 738                 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
 739                                  &tty->winsize.ws_col);
 740                 kill_pg(tty->pgrp, SIGWINCH, 1);
 741         }
 742  out:
 743         if(winch->fd != -1)
 744                 reactivate_fd(winch->fd, WINCH_IRQ);
 745         return IRQ_HANDLED;
 746 }
 747
 748 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty)
 749 {
 750         struct winch *winch;
 751
 752         winch = kmalloc(sizeof(*winch), GFP_KERNEL);
 753         if (winch == NULL) {
 754                 printk("register_winch_irq - kmalloc failed\n");
 755                 return;
 756         }
 757
 758         *winch = ((struct winch) { .list        = LIST_HEAD_INIT(winch->list),
 759                                    .fd          = fd,
 760                                    .tty_fd      = tty_fd,
 761                                    .pid         = pid,
 762                                    .tty         = tty });
 763
 764         spin_lock(&winch_handler_lock);
 765         list_add(&winch->list, &winch_handlers);
 766         spin_unlock(&winch_handler_lock);
 767
 768         if(um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
 769                           IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 770                           "winch", winch) < 0)
 771                 printk("register_winch_irq - failed to register IRQ\n");
 772 }
 773
 774 static void free_winch(struct winch *winch)
 775 {
 776         list_del(&winch->list);
 777
 778         if(winch->pid != -1)
 779                 os_kill_process(winch->pid, 1);
 780         if(winch->fd != -1)
 781                 os_close_file(winch->fd);
 782
 783         free_irq(WINCH_IRQ, winch);
 784         kfree(winch);
 785 }
 786
 787 static void unregister_winch(struct tty_struct *tty)
 788 {
 789         struct list_head *ele;
 790         struct winch *winch;
 791
 792         spin_lock(&winch_handler_lock);
 793
 794         list_for_each(ele, &winch_handlers){
 795                 winch = list_entry(ele, struct winch, list);
 796                 if(winch->tty == tty){
 797                         free_winch(winch);
 798                         break;
 799                 }
 800         }
 801         spin_unlock(&winch_handler_lock);
 802 }
 803
 804 static void winch_cleanup(void)
 805 {
 806         struct list_head *ele, *next;
 807         struct winch *winch;
 808
 809         spin_lock(&winch_handler_lock);
 810
 811         list_for_each_safe(ele, next, &winch_handlers){
 812                 winch = list_entry(ele, struct winch, list);
 813                 free_winch(winch);
 814         }
 815
 816         spin_unlock(&winch_handler_lock);
 817 }
 818 __uml_exitcall(winch_cleanup);
 819
 820 char *add_xterm_umid(char *base)
 821 {
 822         char *umid, *title;
 823         int len;
 824
 825         umid = get_umid();
 826         if(*umid == '\0')
 827                 return base;
 828
 829         len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
 830         title = kmalloc(len, GFP_KERNEL);
 831         if(title == NULL){
 832                 printk("Failed to allocate buffer for xterm title\n");
 833                 return base;
 834         }
 835
 836         snprintf(title, len, "%s (%s)", base, umid);
 837         return title;
 838 }