Loading...
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 "linux/sched.h"
9#include "linux/slab.h"
10#include "chan.h"
11#include "irq_kern.h"
12#include "irq_user.h"
13#include "kern_util.h"
14#include "os.h"
15
16#define LINE_BUFSIZE 4096
17
18static irqreturn_t line_interrupt(int irq, void *data)
19{
20 struct chan *chan = data;
21 struct line *line = chan->line;
22
23 if (line)
24 chan_interrupt(line, line->tty, irq);
25 return IRQ_HANDLED;
26}
27
28/*
29 * Returns the free space inside the ring buffer of this line.
30 *
31 * Should be called while holding line->lock (this does not modify data).
32 */
33static int write_room(struct line *line)
34{
35 int n;
36
37 if (line->buffer == NULL)
38 return LINE_BUFSIZE - 1;
39
40 /* This is for the case where the buffer is wrapped! */
41 n = line->head - line->tail;
42
43 if (n <= 0)
44 n += LINE_BUFSIZE; /* The other case */
45 return n - 1;
46}
47
48int line_write_room(struct tty_struct *tty)
49{
50 struct line *line = tty->driver_data;
51 unsigned long flags;
52 int room;
53
54 spin_lock_irqsave(&line->lock, flags);
55 room = write_room(line);
56 spin_unlock_irqrestore(&line->lock, flags);
57
58 return room;
59}
60
61int line_chars_in_buffer(struct tty_struct *tty)
62{
63 struct line *line = tty->driver_data;
64 unsigned long flags;
65 int ret;
66
67 spin_lock_irqsave(&line->lock, flags);
68 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
69 ret = LINE_BUFSIZE - (write_room(line) + 1);
70 spin_unlock_irqrestore(&line->lock, flags);
71
72 return ret;
73}
74
75/*
76 * This copies the content of buf into the circular buffer associated with
77 * this line.
78 * The return value is the number of characters actually copied, i.e. the ones
79 * for which there was space: this function is not supposed to ever flush out
80 * the circular buffer.
81 *
82 * Must be called while holding line->lock!
83 */
84static int buffer_data(struct line *line, const char *buf, int len)
85{
86 int end, room;
87
88 if (line->buffer == NULL) {
89 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
90 if (line->buffer == NULL) {
91 printk(KERN_ERR "buffer_data - atomic allocation "
92 "failed\n");
93 return 0;
94 }
95 line->head = line->buffer;
96 line->tail = line->buffer;
97 }
98
99 room = write_room(line);
100 len = (len > room) ? room : len;
101
102 end = line->buffer + LINE_BUFSIZE - line->tail;
103
104 if (len < end) {
105 memcpy(line->tail, buf, len);
106 line->tail += len;
107 }
108 else {
109 /* The circular buffer is wrapping */
110 memcpy(line->tail, buf, end);
111 buf += end;
112 memcpy(line->buffer, buf, len - end);
113 line->tail = line->buffer + len - end;
114 }
115
116 return len;
117}
118
119/*
120 * Flushes the ring buffer to the output channels. That is, write_chan is
121 * called, passing it line->head as buffer, and an appropriate count.
122 *
123 * On exit, returns 1 when the buffer is empty,
124 * 0 when the buffer is not empty on exit,
125 * and -errno when an error occurred.
126 *
127 * Must be called while holding line->lock!*/
128static int flush_buffer(struct line *line)
129{
130 int n, count;
131
132 if ((line->buffer == NULL) || (line->head == line->tail))
133 return 1;
134
135 if (line->tail < line->head) {
136 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
137 count = line->buffer + LINE_BUFSIZE - line->head;
138
139 n = write_chan(line->chan_out, line->head, count,
140 line->driver->write_irq);
141 if (n < 0)
142 return n;
143 if (n == count) {
144 /*
145 * We have flushed from ->head to buffer end, now we
146 * must flush only from the beginning to ->tail.
147 */
148 line->head = line->buffer;
149 } else {
150 line->head += n;
151 return 0;
152 }
153 }
154
155 count = line->tail - line->head;
156 n = write_chan(line->chan_out, line->head, count,
157 line->driver->write_irq);
158
159 if (n < 0)
160 return n;
161
162 line->head += n;
163 return line->head == line->tail;
164}
165
166void line_flush_buffer(struct tty_struct *tty)
167{
168 struct line *line = tty->driver_data;
169 unsigned long flags;
170
171 spin_lock_irqsave(&line->lock, flags);
172 flush_buffer(line);
173 spin_unlock_irqrestore(&line->lock, flags);
174}
175
176/*
177 * We map both ->flush_chars and ->put_char (which go in pair) onto
178 * ->flush_buffer and ->write. Hope it's not that bad.
179 */
180void line_flush_chars(struct tty_struct *tty)
181{
182 line_flush_buffer(tty);
183}
184
185int line_put_char(struct tty_struct *tty, unsigned char ch)
186{
187 return line_write(tty, &ch, sizeof(ch));
188}
189
190int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
191{
192 struct line *line = tty->driver_data;
193 unsigned long flags;
194 int n, ret = 0;
195
196 spin_lock_irqsave(&line->lock, flags);
197 if (line->head != line->tail)
198 ret = buffer_data(line, buf, len);
199 else {
200 n = write_chan(line->chan_out, buf, len,
201 line->driver->write_irq);
202 if (n < 0) {
203 ret = n;
204 goto out_up;
205 }
206
207 len -= n;
208 ret += n;
209 if (len > 0)
210 ret += buffer_data(line, buf + n, len);
211 }
212out_up:
213 spin_unlock_irqrestore(&line->lock, flags);
214 return ret;
215}
216
217void line_set_termios(struct tty_struct *tty, struct ktermios * old)
218{
219 /* nothing */
220}
221
222static const struct {
223 int cmd;
224 char *level;
225 char *name;
226} tty_ioctls[] = {
227 /* don't print these, they flood the log ... */
228 { TCGETS, NULL, "TCGETS" },
229 { TCSETS, NULL, "TCSETS" },
230 { TCSETSW, NULL, "TCSETSW" },
231 { TCFLSH, NULL, "TCFLSH" },
232 { TCSBRK, NULL, "TCSBRK" },
233
234 /* general tty stuff */
235 { TCSETSF, KERN_DEBUG, "TCSETSF" },
236 { TCGETA, KERN_DEBUG, "TCGETA" },
237 { TIOCMGET, KERN_DEBUG, "TIOCMGET" },
238 { TCSBRKP, KERN_DEBUG, "TCSBRKP" },
239 { TIOCMSET, KERN_DEBUG, "TIOCMSET" },
240
241 /* linux-specific ones */
242 { TIOCLINUX, KERN_INFO, "TIOCLINUX" },
243 { KDGKBMODE, KERN_INFO, "KDGKBMODE" },
244 { KDGKBTYPE, KERN_INFO, "KDGKBTYPE" },
245 { KDSIGACCEPT, KERN_INFO, "KDSIGACCEPT" },
246};
247
248int line_ioctl(struct tty_struct *tty, unsigned int cmd,
249 unsigned long arg)
250{
251 int ret;
252 int i;
253
254 ret = 0;
255 switch(cmd) {
256#ifdef TIOCGETP
257 case TIOCGETP:
258 case TIOCSETP:
259 case TIOCSETN:
260#endif
261#ifdef TIOCGETC
262 case TIOCGETC:
263 case TIOCSETC:
264#endif
265#ifdef TIOCGLTC
266 case TIOCGLTC:
267 case TIOCSLTC:
268#endif
269 /* Note: these are out of date as we now have TCGETS2 etc but this
270 whole lot should probably go away */
271 case TCGETS:
272 case TCSETSF:
273 case TCSETSW:
274 case TCSETS:
275 case TCGETA:
276 case TCSETAF:
277 case TCSETAW:
278 case TCSETA:
279 case TCXONC:
280 case TCFLSH:
281 case TIOCOUTQ:
282 case TIOCINQ:
283 case TIOCGLCKTRMIOS:
284 case TIOCSLCKTRMIOS:
285 case TIOCPKT:
286 case TIOCGSOFTCAR:
287 case TIOCSSOFTCAR:
288 return -ENOIOCTLCMD;
289#if 0
290 case TCwhatever:
291 /* do something */
292 break;
293#endif
294 default:
295 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
296 if (cmd == tty_ioctls[i].cmd)
297 break;
298 if (i == ARRAY_SIZE(tty_ioctls)) {
299 printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
300 __func__, tty->name, cmd);
301 }
302 ret = -ENOIOCTLCMD;
303 break;
304 }
305 return ret;
306}
307
308void line_throttle(struct tty_struct *tty)
309{
310 struct line *line = tty->driver_data;
311
312 deactivate_chan(line->chan_in, line->driver->read_irq);
313 line->throttled = 1;
314}
315
316void line_unthrottle(struct tty_struct *tty)
317{
318 struct line *line = tty->driver_data;
319
320 line->throttled = 0;
321 chan_interrupt(line, tty, line->driver->read_irq);
322
323 /*
324 * Maybe there is enough stuff pending that calling the interrupt
325 * throttles us again. In this case, line->throttled will be 1
326 * again and we shouldn't turn the interrupt back on.
327 */
328 if (!line->throttled)
329 reactivate_chan(line->chan_in, line->driver->read_irq);
330}
331
332static irqreturn_t line_write_interrupt(int irq, void *data)
333{
334 struct chan *chan = data;
335 struct line *line = chan->line;
336 struct tty_struct *tty = line->tty;
337 int err;
338
339 /*
340 * Interrupts are disabled here because genirq keep irqs disabled when
341 * calling the action handler.
342 */
343
344 spin_lock(&line->lock);
345 err = flush_buffer(line);
346 if (err == 0) {
347 spin_unlock(&line->lock);
348 return IRQ_NONE;
349 } else if (err < 0) {
350 line->head = line->buffer;
351 line->tail = line->buffer;
352 }
353 spin_unlock(&line->lock);
354
355 if (tty == NULL)
356 return IRQ_NONE;
357
358 tty_wakeup(tty);
359 return IRQ_HANDLED;
360}
361
362int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
363{
364 const struct line_driver *driver = line->driver;
365 int err = 0, flags = IRQF_SHARED | IRQF_SAMPLE_RANDOM;
366
367 if (input)
368 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
369 line_interrupt, flags,
370 driver->read_irq_name, data);
371 if (err)
372 return err;
373 if (output)
374 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
375 line_write_interrupt, flags,
376 driver->write_irq_name, data);
377 return err;
378}
379
380/*
381 * Normally, a driver like this can rely mostly on the tty layer
382 * locking, particularly when it comes to the driver structure.
383 * However, in this case, mconsole requests can come in "from the
384 * side", and race with opens and closes.
385 *
386 * mconsole config requests will want to be sure the device isn't in
387 * use, and get_config, open, and close will want a stable
388 * configuration. The checking and modification of the configuration
389 * is done under a spinlock. Checking whether the device is in use is
390 * line->tty->count > 1, also under the spinlock.
391 *
392 * line->count serves to decide whether the device should be enabled or
393 * disabled on the host. If it's equal to 0, then we are doing the
394 * first open or last close. Otherwise, open and close just return.
395 */
396
397int line_open(struct line *lines, struct tty_struct *tty)
398{
399 struct line *line = &lines[tty->index];
400 int err = -ENODEV;
401
402 mutex_lock(&line->count_lock);
403 if (!line->valid)
404 goto out_unlock;
405
406 err = 0;
407 if (line->count++)
408 goto out_unlock;
409
410 BUG_ON(tty->driver_data);
411 tty->driver_data = line;
412 line->tty = tty;
413
414 err = enable_chan(line);
415 if (err) /* line_close() will be called by our caller */
416 goto out_unlock;
417
418 if (!line->sigio) {
419 chan_enable_winch(line->chan_out, tty);
420 line->sigio = 1;
421 }
422
423 chan_window_size(line, &tty->winsize.ws_row,
424 &tty->winsize.ws_col);
425out_unlock:
426 mutex_unlock(&line->count_lock);
427 return err;
428}
429
430static void unregister_winch(struct tty_struct *tty);
431
432void line_close(struct tty_struct *tty, struct file * filp)
433{
434 struct line *line = tty->driver_data;
435
436 /*
437 * If line_open fails (and tty->driver_data is never set),
438 * tty_open will call line_close. So just return in this case.
439 */
440 if (line == NULL)
441 return;
442
443 /* We ignore the error anyway! */
444 flush_buffer(line);
445
446 mutex_lock(&line->count_lock);
447 BUG_ON(!line->valid);
448
449 if (--line->count)
450 goto out_unlock;
451
452 line->tty = NULL;
453 tty->driver_data = NULL;
454
455 if (line->sigio) {
456 unregister_winch(tty);
457 line->sigio = 0;
458 }
459
460out_unlock:
461 mutex_unlock(&line->count_lock);
462}
463
464void close_lines(struct line *lines, int nlines)
465{
466 int i;
467
468 for(i = 0; i < nlines; i++)
469 close_chan(&lines[i]);
470}
471
472int setup_one_line(struct line *lines, int n, char *init,
473 const struct chan_opts *opts, char **error_out)
474{
475 struct line *line = &lines[n];
476 struct tty_driver *driver = line->driver->driver;
477 int err = -EINVAL;
478
479 mutex_lock(&line->count_lock);
480
481 if (line->count) {
482 *error_out = "Device is already open";
483 goto out;
484 }
485
486 if (!strcmp(init, "none")) {
487 if (line->valid) {
488 line->valid = 0;
489 kfree(line->init_str);
490 tty_unregister_device(driver, n);
491 parse_chan_pair(NULL, line, n, opts, error_out);
492 err = 0;
493 }
494 } else {
495 char *new = kstrdup(init, GFP_KERNEL);
496 if (!new) {
497 *error_out = "Failed to allocate memory";
498 return -ENOMEM;
499 }
500 if (line->valid) {
501 tty_unregister_device(driver, n);
502 kfree(line->init_str);
503 }
504 line->init_str = new;
505 line->valid = 1;
506 err = parse_chan_pair(new, line, n, opts, error_out);
507 if (!err) {
508 struct device *d = tty_register_device(driver, n, NULL);
509 if (IS_ERR(d)) {
510 *error_out = "Failed to register device";
511 err = PTR_ERR(d);
512 parse_chan_pair(NULL, line, n, opts, error_out);
513 }
514 }
515 if (err) {
516 line->init_str = NULL;
517 line->valid = 0;
518 kfree(new);
519 }
520 }
521out:
522 mutex_unlock(&line->count_lock);
523 return err;
524}
525
526/*
527 * Common setup code for both startup command line and mconsole initialization.
528 * @lines contains the array (of size @num) to modify;
529 * @init is the setup string;
530 * @error_out is an error string in the case of failure;
531 */
532
533int line_setup(char **conf, unsigned int num, char **def,
534 char *init, char *name)
535{
536 char *error;
537
538 if (*init == '=') {
539 /*
540 * We said con=/ssl= instead of con#=, so we are configuring all
541 * consoles at once.
542 */
543 *def = init + 1;
544 } else {
545 char *end;
546 unsigned n = simple_strtoul(init, &end, 0);
547
548 if (*end != '=') {
549 error = "Couldn't parse device number";
550 goto out;
551 }
552 if (n >= num) {
553 error = "Device number out of range";
554 goto out;
555 }
556 conf[n] = end + 1;
557 }
558 return 0;
559
560out:
561 printk(KERN_ERR "Failed to set up %s with "
562 "configuration string \"%s\" : %s\n", name, init, error);
563 return -EINVAL;
564}
565
566int line_config(struct line *lines, unsigned int num, char *str,
567 const struct chan_opts *opts, char **error_out)
568{
569 char *end;
570 int n;
571
572 if (*str == '=') {
573 *error_out = "Can't configure all devices from mconsole";
574 return -EINVAL;
575 }
576
577 n = simple_strtoul(str, &end, 0);
578 if (*end++ != '=') {
579 *error_out = "Couldn't parse device number";
580 return -EINVAL;
581 }
582 if (n >= num) {
583 *error_out = "Device number out of range";
584 return -EINVAL;
585 }
586
587 return setup_one_line(lines, n, end, opts, error_out);
588}
589
590int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
591 int size, char **error_out)
592{
593 struct line *line;
594 char *end;
595 int dev, n = 0;
596
597 dev = simple_strtoul(name, &end, 0);
598 if ((*end != '\0') || (end == name)) {
599 *error_out = "line_get_config failed to parse device number";
600 return 0;
601 }
602
603 if ((dev < 0) || (dev >= num)) {
604 *error_out = "device number out of range";
605 return 0;
606 }
607
608 line = &lines[dev];
609
610 mutex_lock(&line->count_lock);
611 if (!line->valid)
612 CONFIG_CHUNK(str, size, n, "none", 1);
613 else if (line->tty == NULL)
614 CONFIG_CHUNK(str, size, n, line->init_str, 1);
615 else n = chan_config_string(line, str, size, error_out);
616 mutex_unlock(&line->count_lock);
617
618 return n;
619}
620
621int line_id(char **str, int *start_out, int *end_out)
622{
623 char *end;
624 int n;
625
626 n = simple_strtoul(*str, &end, 0);
627 if ((*end != '\0') || (end == *str))
628 return -1;
629
630 *str = end;
631 *start_out = n;
632 *end_out = n;
633 return n;
634}
635
636int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
637{
638 if (n >= num) {
639 *error_out = "Device number out of range";
640 return -EINVAL;
641 }
642 return setup_one_line(lines, n, "none", NULL, error_out);
643}
644
645int register_lines(struct line_driver *line_driver,
646 const struct tty_operations *ops,
647 struct line *lines, int nlines)
648{
649 struct tty_driver *driver = alloc_tty_driver(nlines);
650 int err;
651 int i;
652
653 if (!driver)
654 return -ENOMEM;
655
656 driver->driver_name = line_driver->name;
657 driver->name = line_driver->device_name;
658 driver->major = line_driver->major;
659 driver->minor_start = line_driver->minor_start;
660 driver->type = line_driver->type;
661 driver->subtype = line_driver->subtype;
662 driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
663 driver->init_termios = tty_std_termios;
664
665 for (i = 0; i < nlines; i++) {
666 spin_lock_init(&lines[i].lock);
667 mutex_init(&lines[i].count_lock);
668 lines[i].driver = line_driver;
669 INIT_LIST_HEAD(&lines[i].chan_list);
670 }
671 tty_set_operations(driver, ops);
672
673 err = tty_register_driver(driver);
674 if (err) {
675 printk(KERN_ERR "register_lines : can't register %s driver\n",
676 line_driver->name);
677 put_tty_driver(driver);
678 return err;
679 }
680
681 line_driver->driver = driver;
682 mconsole_register_dev(&line_driver->mc);
683 return 0;
684}
685
686static DEFINE_SPINLOCK(winch_handler_lock);
687static LIST_HEAD(winch_handlers);
688
689struct winch {
690 struct list_head list;
691 int fd;
692 int tty_fd;
693 int pid;
694 struct tty_struct *tty;
695 unsigned long stack;
696 struct work_struct work;
697};
698
699static void __free_winch(struct work_struct *work)
700{
701 struct winch *winch = container_of(work, struct winch, work);
702 um_free_irq(WINCH_IRQ, winch);
703
704 if (winch->pid != -1)
705 os_kill_process(winch->pid, 1);
706 if (winch->stack != 0)
707 free_stack(winch->stack, 0);
708 kfree(winch);
709}
710
711static void free_winch(struct winch *winch)
712{
713 int fd = winch->fd;
714 winch->fd = -1;
715 if (fd != -1)
716 os_close_file(fd);
717 list_del(&winch->list);
718 __free_winch(&winch->work);
719}
720
721static irqreturn_t winch_interrupt(int irq, void *data)
722{
723 struct winch *winch = data;
724 struct tty_struct *tty;
725 struct line *line;
726 int fd = winch->fd;
727 int err;
728 char c;
729
730 if (fd != -1) {
731 err = generic_read(fd, &c, NULL);
732 if (err < 0) {
733 if (err != -EAGAIN) {
734 winch->fd = -1;
735 list_del(&winch->list);
736 os_close_file(fd);
737 printk(KERN_ERR "winch_interrupt : "
738 "read failed, errno = %d\n", -err);
739 printk(KERN_ERR "fd %d is losing SIGWINCH "
740 "support\n", winch->tty_fd);
741 INIT_WORK(&winch->work, __free_winch);
742 schedule_work(&winch->work);
743 return IRQ_HANDLED;
744 }
745 goto out;
746 }
747 }
748 tty = winch->tty;
749 if (tty != NULL) {
750 line = tty->driver_data;
751 if (line != NULL) {
752 chan_window_size(line, &tty->winsize.ws_row,
753 &tty->winsize.ws_col);
754 kill_pgrp(tty->pgrp, SIGWINCH, 1);
755 }
756 }
757 out:
758 if (winch->fd != -1)
759 reactivate_fd(winch->fd, WINCH_IRQ);
760 return IRQ_HANDLED;
761}
762
763void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
764 unsigned long stack)
765{
766 struct winch *winch;
767
768 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
769 if (winch == NULL) {
770 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
771 goto cleanup;
772 }
773
774 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
775 .fd = fd,
776 .tty_fd = tty_fd,
777 .pid = pid,
778 .tty = tty,
779 .stack = stack });
780
781 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
782 IRQF_SHARED | IRQF_SAMPLE_RANDOM,
783 "winch", winch) < 0) {
784 printk(KERN_ERR "register_winch_irq - failed to register "
785 "IRQ\n");
786 goto out_free;
787 }
788
789 spin_lock(&winch_handler_lock);
790 list_add(&winch->list, &winch_handlers);
791 spin_unlock(&winch_handler_lock);
792
793 return;
794
795 out_free:
796 kfree(winch);
797 cleanup:
798 os_kill_process(pid, 1);
799 os_close_file(fd);
800 if (stack != 0)
801 free_stack(stack, 0);
802}
803
804static void unregister_winch(struct tty_struct *tty)
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 if (winch->tty == tty) {
814 free_winch(winch);
815 break;
816 }
817 }
818 spin_unlock(&winch_handler_lock);
819}
820
821static void winch_cleanup(void)
822{
823 struct list_head *ele, *next;
824 struct winch *winch;
825
826 spin_lock(&winch_handler_lock);
827
828 list_for_each_safe(ele, next, &winch_handlers) {
829 winch = list_entry(ele, struct winch, list);
830 free_winch(winch);
831 }
832
833 spin_unlock(&winch_handler_lock);
834}
835__uml_exitcall(winch_cleanup);
836
837char *add_xterm_umid(char *base)
838{
839 char *umid, *title;
840 int len;
841
842 umid = get_umid();
843 if (*umid == '\0')
844 return base;
845
846 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
847 title = kmalloc(len, GFP_KERNEL);
848 if (title == NULL) {
849 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
850 return base;
851 }
852
853 snprintf(title, len, "%s (%s)", base, umid);
854 return title;
855}