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