d741f35d7b3a3654e20e2ccf780fc54e8c76f1be
[linux-2.6.git] / 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 int line_put_char(struct tty_struct *tty, unsigned char ch)
195 {
196         return 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                                __func__, 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         tty_wakeup(tty);
366         return IRQ_HANDLED;
367 }
368
369 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
370 {
371         const struct line_driver *driver = line->driver;
372         int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
373
374         if (input)
375                 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
376                                        line_interrupt, flags,
377                                        driver->read_irq_name, data);
378         if (err)
379                 return err;
380         if (output)
381                 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
382                                         line_write_interrupt, flags,
383                                         driver->write_irq_name, data);
384         line->have_irq = 1;
385         return err;
386 }
387
388 /*
389  * Normally, a driver like this can rely mostly on the tty layer
390  * locking, particularly when it comes to the driver structure.
391  * However, in this case, mconsole requests can come in "from the
392  * side", and race with opens and closes.
393  *
394  * mconsole config requests will want to be sure the device isn't in
395  * use, and get_config, open, and close will want a stable
396  * configuration.  The checking and modification of the configuration
397  * is done under a spinlock.  Checking whether the device is in use is
398  * line->tty->count > 1, also under the spinlock.
399  *
400  * tty->count serves to decide whether the device should be enabled or
401  * disabled on the host.  If it's equal to 1, then we are doing the
402  * first open or last close.  Otherwise, open and close just return.
403  */
404
405 int line_open(struct line *lines, struct tty_struct *tty)
406 {
407         struct line *line = &lines[tty->index];
408         int err = -ENODEV;
409
410         spin_lock(&line->count_lock);
411         if (!line->valid)
412                 goto out_unlock;
413
414         err = 0;
415         if (tty->count > 1)
416                 goto out_unlock;
417
418         spin_unlock(&line->count_lock);
419
420         tty->driver_data = line;
421         line->tty = tty;
422
423         err = enable_chan(line);
424         if (err)
425                 return err;
426
427         INIT_DELAYED_WORK(&line->task, line_timer_cb);
428
429         if (!line->sigio) {
430                 chan_enable_winch(&line->chan_list, tty);
431                 line->sigio = 1;
432         }
433
434         chan_window_size(&line->chan_list, &tty->winsize.ws_row,
435                          &tty->winsize.ws_col);
436
437         return err;
438
439 out_unlock:
440         spin_unlock(&line->count_lock);
441         return err;
442 }
443
444 static void unregister_winch(struct tty_struct *tty);
445
446 void line_close(struct tty_struct *tty, struct file * filp)
447 {
448         struct line *line = tty->driver_data;
449
450         /*
451          * If line_open fails (and tty->driver_data is never set),
452          * tty_open will call line_close.  So just return in this case.
453          */
454         if (line == NULL)
455                 return;
456
457         /* We ignore the error anyway! */
458         flush_buffer(line);
459
460         spin_lock(&line->count_lock);
461         if (!line->valid)
462                 goto out_unlock;
463
464         if (tty->count > 1)
465                 goto out_unlock;
466
467         spin_unlock(&line->count_lock);
468
469         line->tty = NULL;
470         tty->driver_data = NULL;
471
472         if (line->sigio) {
473                 unregister_winch(tty);
474                 line->sigio = 0;
475         }
476
477         return;
478
479 out_unlock:
480         spin_unlock(&line->count_lock);
481 }
482
483 void close_lines(struct line *lines, int nlines)
484 {
485         int i;
486
487         for(i = 0; i < nlines; i++)
488                 close_chan(&lines[i].chan_list, 0);
489 }
490
491 static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
492                           char **error_out)
493 {
494         struct line *line = &lines[n];
495         int err = -EINVAL;
496
497         spin_lock(&line->count_lock);
498
499         if (line->tty != NULL) {
500                 *error_out = "Device is already open";
501                 goto out;
502         }
503
504         if (line->init_pri <= init_prio) {
505                 line->init_pri = init_prio;
506                 if (!strcmp(init, "none"))
507                         line->valid = 0;
508                 else {
509                         line->init_str = init;
510                         line->valid = 1;
511                 }
512         }
513         err = 0;
514 out:
515         spin_unlock(&line->count_lock);
516         return err;
517 }
518
519 /*
520  * Common setup code for both startup command line and mconsole initialization.
521  * @lines contains the array (of size @num) to modify;
522  * @init is the setup string;
523  * @error_out is an error string in the case of failure;
524  */
525
526 int line_setup(struct line *lines, unsigned int num, char *init,
527                char **error_out)
528 {
529         int i, n, err;
530         char *end;
531
532         if (*init == '=') {
533                 /*
534                  * We said con=/ssl= instead of con#=, so we are configuring all
535                  * consoles at once.
536                  */
537                 n = -1;
538         }
539         else {
540                 n = simple_strtoul(init, &end, 0);
541                 if (*end != '=') {
542                         *error_out = "Couldn't parse device number";
543                         return -EINVAL;
544                 }
545                 init = end;
546         }
547         init++;
548
549         if (n >= (signed int) num) {
550                 *error_out = "Device number out of range";
551                 return -EINVAL;
552         }
553         else if (n >= 0) {
554                 err = setup_one_line(lines, n, init, INIT_ONE, error_out);
555                 if (err)
556                         return err;
557         }
558         else {
559                 for(i = 0; i < num; i++) {
560                         err = setup_one_line(lines, i, init, INIT_ALL,
561                                              error_out);
562                         if (err)
563                                 return err;
564                 }
565         }
566         return n == -1 ? num : n;
567 }
568
569 int line_config(struct line *lines, unsigned int num, char *str,
570                 const struct chan_opts *opts, char **error_out)
571 {
572         struct line *line;
573         char *new;
574         int n;
575
576         if (*str == '=') {
577                 *error_out = "Can't configure all devices from mconsole";
578                 return -EINVAL;
579         }
580
581         new = kstrdup(str, GFP_KERNEL);
582         if (new == NULL) {
583                 *error_out = "Failed to allocate memory";
584                 return -ENOMEM;
585         }
586         n = line_setup(lines, num, new, error_out);
587         if (n < 0)
588                 return n;
589
590         line = &lines[n];
591         return parse_chan_pair(line->init_str, line, n, opts, error_out);
592 }
593
594 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
595                     int size, char **error_out)
596 {
597         struct line *line;
598         char *end;
599         int dev, n = 0;
600
601         dev = simple_strtoul(name, &end, 0);
602         if ((*end != '\0') || (end == name)) {
603                 *error_out = "line_get_config failed to parse device number";
604                 return 0;
605         }
606
607         if ((dev < 0) || (dev >= num)) {
608                 *error_out = "device number out of range";
609                 return 0;
610         }
611
612         line = &lines[dev];
613
614         spin_lock(&line->count_lock);
615         if (!line->valid)
616                 CONFIG_CHUNK(str, size, n, "none", 1);
617         else if (line->tty == NULL)
618                 CONFIG_CHUNK(str, size, n, line->init_str, 1);
619         else n = chan_config_string(&line->chan_list, str, size, error_out);
620         spin_unlock(&line->count_lock);
621
622         return n;
623 }
624
625 int line_id(char **str, int *start_out, int *end_out)
626 {
627         char *end;
628         int n;
629
630         n = simple_strtoul(*str, &end, 0);
631         if ((*end != '\0') || (end == *str))
632                 return -1;
633
634         *str = end;
635         *start_out = n;
636         *end_out = n;
637         return n;
638 }
639
640 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
641 {
642         int err;
643         char config[sizeof("conxxxx=none\0")];
644
645         sprintf(config, "%d=none", n);
646         err = line_setup(lines, num, config, error_out);
647         if (err >= 0)
648                 err = 0;
649         return err;
650 }
651
652 struct tty_driver *register_lines(struct line_driver *line_driver,
653                                   const struct tty_operations *ops,
654                                   struct line *lines, int nlines)
655 {
656         int i;
657         struct tty_driver *driver = alloc_tty_driver(nlines);
658
659         if (!driver)
660                 return NULL;
661
662         driver->driver_name = line_driver->name;
663         driver->name = line_driver->device_name;
664         driver->major = line_driver->major;
665         driver->minor_start = line_driver->minor_start;
666         driver->type = line_driver->type;
667         driver->subtype = line_driver->subtype;
668         driver->flags = TTY_DRIVER_REAL_RAW;
669         driver->init_termios = tty_std_termios;
670         tty_set_operations(driver, ops);
671
672         if (tty_register_driver(driver)) {
673                 printk(KERN_ERR "register_lines : can't register %s driver\n",
674                        line_driver->name);
675                 put_tty_driver(driver);
676                 return NULL;
677         }
678
679         for(i = 0; i < nlines; i++) {
680                 if (!lines[i].valid)
681                         tty_unregister_device(driver, i);
682         }
683
684         mconsole_register_dev(&line_driver->mc);
685         return driver;
686 }
687
688 static DEFINE_SPINLOCK(winch_handler_lock);
689 static LIST_HEAD(winch_handlers);
690
691 void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
692 {
693         struct line *line;
694         char *error;
695         int i;
696
697         for(i = 0; i < nlines; i++) {
698                 line = &lines[i];
699                 INIT_LIST_HEAD(&line->chan_list);
700
701                 if (line->init_str == NULL)
702                         continue;
703
704                 line->init_str = kstrdup(line->init_str, GFP_KERNEL);
705                 if (line->init_str == NULL)
706                         printk(KERN_ERR "lines_init - kstrdup returned NULL\n");
707
708                 if (parse_chan_pair(line->init_str, line, i, opts, &error)) {
709                         printk(KERN_ERR "parse_chan_pair failed for "
710                                "device %d : %s\n", i, error);
711                         line->valid = 0;
712                 }
713         }
714 }
715
716 struct winch {
717         struct list_head list;
718         int fd;
719         int tty_fd;
720         int pid;
721         struct tty_struct *tty;
722         unsigned long stack;
723 };
724
725 static void free_winch(struct winch *winch, int free_irq_ok)
726 {
727         list_del(&winch->list);
728
729         if (winch->pid != -1)
730                 os_kill_process(winch->pid, 1);
731         if (winch->fd != -1)
732                 os_close_file(winch->fd);
733         if (winch->stack != 0)
734                 free_stack(winch->stack, 0);
735         if (free_irq_ok)
736                 free_irq(WINCH_IRQ, winch);
737         kfree(winch);
738 }
739
740 static irqreturn_t winch_interrupt(int irq, void *data)
741 {
742         struct winch *winch = data;
743         struct tty_struct *tty;
744         struct line *line;
745         int err;
746         char c;
747
748         if (winch->fd != -1) {
749                 err = generic_read(winch->fd, &c, NULL);
750                 if (err < 0) {
751                         if (err != -EAGAIN) {
752                                 printk(KERN_ERR "winch_interrupt : "
753                                        "read failed, errno = %d\n", -err);
754                                 printk(KERN_ERR "fd %d is losing SIGWINCH "
755                                        "support\n", winch->tty_fd);
756                                 free_winch(winch, 0);
757                                 return IRQ_HANDLED;
758                         }
759                         goto out;
760                 }
761         }
762         tty = winch->tty;
763         if (tty != NULL) {
764                 line = tty->driver_data;
765                 if (line != NULL) {
766                         chan_window_size(&line->chan_list, &tty->winsize.ws_row,
767                                          &tty->winsize.ws_col);
768                         kill_pgrp(tty->pgrp, SIGWINCH, 1);
769                 }
770         }
771  out:
772         if (winch->fd != -1)
773                 reactivate_fd(winch->fd, WINCH_IRQ);
774         return IRQ_HANDLED;
775 }
776
777 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
778                         unsigned long stack)
779 {
780         struct winch *winch;
781
782         winch = kmalloc(sizeof(*winch), GFP_KERNEL);
783         if (winch == NULL) {
784                 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
785                 goto cleanup;
786         }
787
788         *winch = ((struct winch) { .list        = LIST_HEAD_INIT(winch->list),
789                                    .fd          = fd,
790                                    .tty_fd      = tty_fd,
791                                    .pid         = pid,
792                                    .tty         = tty,
793                                    .stack       = stack });
794
795         if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
796                            IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
797                            "winch", winch) < 0) {
798                 printk(KERN_ERR "register_winch_irq - failed to register "
799                        "IRQ\n");
800                 goto out_free;
801         }
802
803         spin_lock(&winch_handler_lock);
804         list_add(&winch->list, &winch_handlers);
805         spin_unlock(&winch_handler_lock);
806
807         return;
808
809  out_free:
810         kfree(winch);
811  cleanup:
812         os_kill_process(pid, 1);
813         os_close_file(fd);
814         if (stack != 0)
815                 free_stack(stack, 0);
816 }
817
818 static void unregister_winch(struct tty_struct *tty)
819 {
820         struct list_head *ele;
821         struct winch *winch;
822
823         spin_lock(&winch_handler_lock);
824
825         list_for_each(ele, &winch_handlers) {
826                 winch = list_entry(ele, struct winch, list);
827                 if (winch->tty == tty) {
828                         free_winch(winch, 1);
829                         break;
830                 }
831         }
832         spin_unlock(&winch_handler_lock);
833 }
834
835 static void winch_cleanup(void)
836 {
837         struct list_head *ele, *next;
838         struct winch *winch;
839
840         spin_lock(&winch_handler_lock);
841
842         list_for_each_safe(ele, next, &winch_handlers) {
843                 winch = list_entry(ele, struct winch, list);
844                 free_winch(winch, 1);
845         }
846
847         spin_unlock(&winch_handler_lock);
848 }
849 __uml_exitcall(winch_cleanup);
850
851 char *add_xterm_umid(char *base)
852 {
853         char *umid, *title;
854         int len;
855
856         umid = get_umid();
857         if (*umid == '\0')
858                 return base;
859
860         len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
861         title = kmalloc(len, GFP_KERNEL);
862         if (title == NULL) {
863                 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
864                 return base;
865         }
866
867         snprintf(title, len, "%s (%s)", base, umid);
868         return title;
869 }