summaryrefslogtreecommitdiff
path: root/arch/um/drivers/chan_kern.c
blob: acbe6c67afbaa1efe09952b9c1987b17b5afa58b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
/*
 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
 * Licensed under the GPL
 */

#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include "chan.h"
#include <os.h>
#include <irq_kern.h>

#ifdef CONFIG_NOCONFIG_CHAN
static void *not_configged_init(char *str, int device,
				const struct chan_opts *opts)
{
	printk(KERN_ERR "Using a channel type which is configured out of "
	       "UML\n");
	return NULL;
}

static int not_configged_open(int input, int output, int primary, void *data,
			      char **dev_out)
{
	printk(KERN_ERR "Using a channel type which is configured out of "
	       "UML\n");
	return -ENODEV;
}

static void not_configged_close(int fd, void *data)
{
	printk(KERN_ERR "Using a channel type which is configured out of "
	       "UML\n");
}

static int not_configged_read(int fd, char *c_out, void *data)
{
	printk(KERN_ERR "Using a channel type which is configured out of "
	       "UML\n");
	return -EIO;
}

static int not_configged_write(int fd, const char *buf, int len, void *data)
{
	printk(KERN_ERR "Using a channel type which is configured out of "
	       "UML\n");
	return -EIO;
}

static int not_configged_console_write(int fd, const char *buf, int len)
{
	printk(KERN_ERR "Using a channel type which is configured out of "
	       "UML\n");
	return -EIO;
}

static int not_configged_window_size(int fd, void *data, unsigned short *rows,
				     unsigned short *cols)
{
	printk(KERN_ERR "Using a channel type which is configured out of "
	       "UML\n");
	return -ENODEV;
}

static void not_configged_free(void *data)
{
	printk(KERN_ERR "Using a channel type which is configured out of "
	       "UML\n");
}

static const struct chan_ops not_configged_ops = {
	.init		= not_configged_init,
	.open		= not_configged_open,
	.close		= not_configged_close,
	.read		= not_configged_read,
	.write		= not_configged_write,
	.console_write	= not_configged_console_write,
	.window_size	= not_configged_window_size,
	.free		= not_configged_free,
	.winch		= 0,
};
#endif /* CONFIG_NOCONFIG_CHAN */

static int open_one_chan(struct chan *chan)
{
	int fd, err;

	if (chan->opened)
		return 0;

	if (chan->ops->open == NULL)
		fd = 0;
	else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
				     chan->data, &chan->dev);
	if (fd < 0)
		return fd;

	err = os_set_fd_block(fd, 0);
	if (err) {
		(*chan->ops->close)(fd, chan->data);
		return err;
	}

	chan->fd = fd;

	chan->opened = 1;
	return 0;
}

static int open_chan(struct list_head *chans)
{
	struct list_head *ele;
	struct chan *chan;
	int ret, err = 0;

	list_for_each(ele, chans) {
		chan = list_entry(ele, struct chan, list);
		ret = open_one_chan(chan);
		if (chan->primary)
			err = ret;
	}
	return err;
}

void chan_enable_winch(struct chan *chan, struct tty_port *port)
{
	if (chan && chan->primary && chan->ops->winch)
		register_winch(chan->fd, port);
}

static void line_timer_cb(struct work_struct *work)
{
	struct line *line = container_of(work, struct line, task.work);

	if (!line->throttled)
		chan_interrupt(line, line->driver->read_irq);
}

int enable_chan(struct line *line)
{
	struct list_head *ele;
	struct chan *chan;
	int err;

	INIT_DELAYED_WORK(&line->task, line_timer_cb);

	list_for_each(ele, &line->chan_list) {
		chan = list_entry(ele, struct chan, list);
		err = open_one_chan(chan);
		if (err) {
			if (chan->primary)
				goto out_close;

			continue;
		}

		if (chan->enabled)
			continue;
		err = line_setup_irq(chan->fd, chan->input, chan->output, line,
				     chan);
		if (err)
			goto out_close;

		chan->enabled = 1;
	}

	return 0;

 out_close:
	close_chan(line);
	return err;
}

/* Items are added in IRQ context, when free_irq can't be called, and
 * removed in process context, when it can.
 * This handles interrupt sources which disappear, and which need to
 * be permanently disabled.  This is discovered in IRQ context, but
 * the freeing of the IRQ must be done later.
 */
static DEFINE_SPINLOCK(irqs_to_free_lock);
static LIST_HEAD(irqs_to_free);

void free_irqs(void)
{
	struct chan *chan;
	LIST_HEAD(list);
	struct list_head *ele;
	unsigned long flags;

	spin_lock_irqsave(&irqs_to_free_lock, flags);
	list_splice_init(&irqs_to_free, &list);
	spin_unlock_irqrestore(&irqs_to_free_lock, flags);

	list_for_each(ele, &list) {
		chan = list_entry(ele, struct chan, free_list);

		if (chan->input && chan->enabled)
			um_free_irq(chan->line->driver->read_irq, chan);
		if (chan->output && chan->enabled)
			um_free_irq(chan->line->driver->write_irq, chan);
		chan->enabled = 0;
	}
}

static void close_one_chan(struct chan *chan, int delay_free_irq)
{
	unsigned long flags;

	if (!chan->opened)
		return;

	if (delay_free_irq) {
		spin_lock_irqsave(&irqs_to_free_lock, flags);
		list_add(&chan->free_list, &irqs_to_free);
		spin_unlock_irqrestore(&irqs_to_free_lock, flags);
	}
	else {
		if (chan->input && chan->enabled)
			um_free_irq(chan->line->driver->read_irq, chan);
		if (chan->output && chan->enabled)
			um_free_irq(chan->line->driver->write_irq, chan);
		chan->enabled = 0;
	}
	if (chan->ops->close != NULL)
		(*chan->ops->close)(chan->fd, chan->data);

	chan->opened = 0;
	chan->fd = -1;
}

void close_chan(struct line *line)
{
	struct chan *chan;

	/* Close in reverse order as open in case more than one of them
	 * refers to the same device and they save and restore that device's
	 * state.  Then, the first one opened will have the original state,
	 * so it must be the last closed.
	 */
	list_for_each_entry_reverse(chan, &line->chan_list, list) {
		close_one_chan(chan, 0);
	}
}

void deactivate_chan(struct chan *chan, int irq)
{
	if (chan && chan->enabled)
		deactivate_fd(chan->fd, irq);
}

void reactivate_chan(struct chan *chan, int irq)
{
	if (chan && chan->enabled)
		reactivate_fd(chan->fd, irq);
}

int write_chan(struct chan *chan, const char *buf, int len,
	       int write_irq)
{
	int n, ret = 0;

	if (len == 0 || !chan || !chan->ops->write)
		return 0;

	n = chan->ops->write(chan->fd, buf, len, chan->data);
	if (chan->primary) {
		ret = n;
		if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
			reactivate_fd(chan->fd, write_irq);
	}
	return ret;
}

int console_write_chan(struct chan *chan, const char *buf, int len)
{
	int n, ret = 0;

	if (!chan || !chan->ops->console_write)
		return 0;

	n = chan->ops->console_write(chan->fd, buf, len);
	if (chan->primary)
		ret = n;
	return ret;
}

int console_open_chan(struct line *line, struct console *co)
{
	int err;

	err = open_chan(&line->chan_list);
	if (err)
		return err;

	printk(KERN_INFO "Console initialized on /dev/%s%d\n", co->name,
	       co->index);
	return 0;
}

int chan_window_size(struct line *line, unsigned short *rows_out,
		      unsigned short *cols_out)
{
	struct chan *chan;

	chan = line->chan_in;
	if (chan && chan->primary) {
		if (chan->ops->window_size == NULL)
			return 0;
		return chan->ops->window_size(chan->fd, chan->data,
					      rows_out, cols_out);
	}
	chan = line->chan_out;
	if (chan && chan->primary) {
		if (chan->ops->window_size == NULL)
			return 0;
		return chan->ops->window_size(chan->fd, chan->data,
					      rows_out, cols_out);
	}
	return 0;
}

static void free_one_chan(struct chan *chan)
{
	list_del(&chan->list);

	close_one_chan(chan, 0);

	if (chan->ops->free != NULL)
		(*chan->ops->free)(chan->data);

	if (chan->primary && chan->output)
		ignore_sigio_fd(chan->fd);
	kfree(chan);
}

static void free_chan(struct list_head *chans)
{
	struct list_head *ele, *next;
	struct chan *chan;

	list_for_each_safe(ele, next, chans) {
		chan = list_entry(ele, struct chan, list);
		free_one_chan(chan);
	}
}

static int one_chan_config_string(struct chan *chan, char *str, int size,
				  char **error_out)
{
	int n = 0;

	if (chan == NULL) {
		CONFIG_CHUNK(str, size, n, "none", 1);
		return n;
	}

	CONFIG_CHUNK(str, size, n, chan->ops->type, 0);

	if (chan->dev == NULL) {
		CONFIG_CHUNK(str, size, n, "", 1);
		return n;
	}

	CONFIG_CHUNK(str, size, n, ":", 0);
	CONFIG_CHUNK(str, size, n, chan->dev, 0);

	return n;
}

static int chan_pair_config_string(struct chan *in, struct chan *out,
				   char *str, int size, char **error_out)
{
	int n;

	n = one_chan_config_string(in, str, size, error_out);
	str += n;
	size -= n;

	if (in == out) {
		CONFIG_CHUNK(str, size, n, "", 1);
		return n;
	}

	CONFIG_CHUNK(str, size, n, ",", 1);
	n = one_chan_config_string(out, str, size, error_out);
	str += n;
	size -= n;
	CONFIG_CHUNK(str, size, n, "", 1);

	return n;
}

int chan_config_string(struct line *line, char *str, int size,
		       char **error_out)
{
	struct chan *in = line->chan_in, *out = line->chan_out;

	if (in && !in->primary)
		in = NULL;
	if (out && !out->primary)
		out = NULL;

	return chan_pair_config_string(in, out, str, size, error_out);
}

struct chan_type {
	char *key;
	const struct chan_ops *ops;
};

static const struct chan_type chan_table[] = {
	{ "fd", &fd_ops },

#ifdef CONFIG_NULL_CHAN
	{ "null", &null_ops },
#else
	{ "null", &not_configged_ops },
#endif

#ifdef CONFIG_PORT_CHAN
	{ "port", &port_ops },
#else
	{ "port", &not_configged_ops },
#endif

#ifdef CONFIG_PTY_CHAN
	{ "pty", &pty_ops },
	{ "pts", &pts_ops },
#else
	{ "pty", &not_configged_ops },
	{ "pts", &not_configged_ops },
#endif

#ifdef CONFIG_TTY_CHAN
	{ "tty", &tty_ops },
#else
	{ "tty", &not_configged_ops },
#endif

#ifdef CONFIG_XTERM_CHAN
	{ "xterm", &xterm_ops },
#else
	{ "xterm", &not_configged_ops },
#endif
};

static struct chan *parse_chan(struct line *line, char *str, int device,
			       const struct chan_opts *opts, char **error_out)
{
	const struct chan_type *entry;
	const struct chan_ops *ops;
	struct chan *chan;
	void *data;
	int i;

	ops = NULL;
	data = NULL;
	for(i = 0; i < ARRAY_SIZE(chan_table); i++) {
		entry = &chan_table[i];
		if (!strncmp(str, entry->key, strlen(entry->key))) {
			ops = entry->ops;
			str += strlen(entry->key);
			break;
		}
	}
	if (ops == NULL) {
		*error_out = "No match for configured backends";
		return NULL;
	}

	data = (*ops->init)(str, device, opts);
	if (data == NULL) {
		*error_out = "Configuration failed";
		return NULL;
	}

	chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
	if (chan == NULL) {
		*error_out = "Memory allocation failed";
		return NULL;
	}
	*chan = ((struct chan) { .list	 	= LIST_HEAD_INIT(chan->list),
				 .free_list 	=
				 	LIST_HEAD_INIT(chan->free_list),
				 .line		= line,
				 .primary	= 1,
				 .input		= 0,
				 .output 	= 0,
				 .opened  	= 0,
				 .enabled  	= 0,
				 .fd 		= -1,
				 .ops 		= ops,
				 .data 		= data });
	return chan;
}

int parse_chan_pair(char *str, struct line *line, int device,
		    const struct chan_opts *opts, char **error_out)
{
	struct list_head *chans = &line->chan_list;
	struct chan *new;
	char *in, *out;

	if (!list_empty(chans)) {
		line->chan_in = line->chan_out = NULL;
		free_chan(chans);
		INIT_LIST_HEAD(chans);
	}

	if (!str)
		return 0;

	out = strchr(str, ',');
	if (out != NULL) {
		in = str;
		*out = '\0';
		out++;
		new = parse_chan(line, in, device, opts, error_out);
		if (new == NULL)
			return -1;

		new->input = 1;
		list_add(&new->list, chans);
		line->chan_in = new;

		new = parse_chan(line, out, device, opts, error_out);
		if (new == NULL)
			return -1;

		list_add(&new->list, chans);
		new->output = 1;
		line->chan_out = new;
	}
	else {
		new = parse_chan(line, str, device, opts, error_out);
		if (new == NULL)
			return -1;

		list_add(&new->list, chans);
		new->input = 1;
		new->output = 1;
		line->chan_in = line->chan_out = new;
	}
	return 0;
}

void chan_interrupt(struct line *line, int irq)
{
	struct tty_port *port = &line->port;
	struct chan *chan = line->chan_in;
	int err;
	char c;

	if (!chan || !chan->ops->read)
		goto out;

	do {
		if (!tty_buffer_request_room(port, 1)) {
			schedule_delayed_work(&line->task, 1);
			goto out;
		}
		err = chan->ops->read(chan->fd, &c, chan->data);
		if (err > 0)
			tty_insert_flip_char(port, c, TTY_NORMAL);
	} while (err > 0);

	if (err == 0)
		reactivate_fd(chan->fd, irq);
	if (err == -EIO) {
		if (chan->primary) {
			tty_port_tty_hangup(&line->port, false);
			if (line->chan_out != chan)
				close_one_chan(line->chan_out, 1);
		}
		close_one_chan(chan, 1);
		if (chan->primary)
			return;
	}
 out:
	tty_flip_buffer_push(port);
}