xref: /openbmc/linux/arch/um/drivers/chan_kern.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include <linux/stddef.h>
7 #include <linux/kernel.h>
8 #include <linux/list.h>
9 #include <linux/slab.h>
10 #include <linux/tty.h>
11 #include <linux/string.h>
12 #include <linux/tty_flip.h>
13 #include <asm/irq.h>
14 #include "chan_kern.h"
15 #include "user_util.h"
16 #include "kern.h"
17 #include "irq_user.h"
18 #include "sigio.h"
19 #include "line.h"
20 #include "os.h"
21 
22 #ifdef CONFIG_NOCONFIG_CHAN
23 static void *not_configged_init(char *str, int device, struct chan_opts *opts)
24 {
25 	printk(KERN_ERR "Using a channel type which is configured out of "
26 	       "UML\n");
27 	return(NULL);
28 }
29 
30 static int not_configged_open(int input, int output, int primary, void *data,
31 			      char **dev_out)
32 {
33 	printk(KERN_ERR "Using a channel type which is configured out of "
34 	       "UML\n");
35 	return(-ENODEV);
36 }
37 
38 static void not_configged_close(int fd, void *data)
39 {
40 	printk(KERN_ERR "Using a channel type which is configured out of "
41 	       "UML\n");
42 }
43 
44 static int not_configged_read(int fd, char *c_out, void *data)
45 {
46 	printk(KERN_ERR "Using a channel type which is configured out of "
47 	       "UML\n");
48 	return(-EIO);
49 }
50 
51 static int not_configged_write(int fd, const char *buf, int len, void *data)
52 {
53 	printk(KERN_ERR "Using a channel type which is configured out of "
54 	       "UML\n");
55 	return(-EIO);
56 }
57 
58 static int not_configged_console_write(int fd, const char *buf, int len,
59 				       void *data)
60 {
61 	printk(KERN_ERR "Using a channel type which is configured out of "
62 	       "UML\n");
63 	return(-EIO);
64 }
65 
66 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
67 				     unsigned short *cols)
68 {
69 	printk(KERN_ERR "Using a channel type which is configured out of "
70 	       "UML\n");
71 	return(-ENODEV);
72 }
73 
74 static void not_configged_free(void *data)
75 {
76 	printk(KERN_ERR "Using a channel type which is configured out of "
77 	       "UML\n");
78 }
79 
80 static struct chan_ops not_configged_ops = {
81 	.init		= not_configged_init,
82 	.open		= not_configged_open,
83 	.close		= not_configged_close,
84 	.read		= not_configged_read,
85 	.write		= not_configged_write,
86 	.console_write	= not_configged_console_write,
87 	.window_size	= not_configged_window_size,
88 	.free		= not_configged_free,
89 	.winch		= 0,
90 };
91 #endif /* CONFIG_NOCONFIG_CHAN */
92 
93 void generic_close(int fd, void *unused)
94 {
95 	os_close_file(fd);
96 }
97 
98 int generic_read(int fd, char *c_out, void *unused)
99 {
100 	int n;
101 
102 	n = os_read_file(fd, c_out, sizeof(*c_out));
103 
104 	if(n == -EAGAIN)
105 		return(0);
106 	else if(n == 0)
107 		return(-EIO);
108 	return(n);
109 }
110 
111 /* XXX Trivial wrapper around os_write_file */
112 
113 int generic_write(int fd, const char *buf, int n, void *unused)
114 {
115 	return(os_write_file(fd, buf, n));
116 }
117 
118 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
119 			unsigned short *cols_out)
120 {
121 	int rows, cols;
122 	int ret;
123 
124 	ret = os_window_size(fd, &rows, &cols);
125 	if(ret < 0)
126 		return(ret);
127 
128 	ret = ((*rows_out != rows) || (*cols_out != cols));
129 
130 	*rows_out = rows;
131 	*cols_out = cols;
132 
133 	return(ret);
134 }
135 
136 void generic_free(void *data)
137 {
138 	kfree(data);
139 }
140 
141 static void tty_receive_char(struct tty_struct *tty, char ch)
142 {
143 	if(tty == NULL) return;
144 
145 	if(I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
146 		if(ch == STOP_CHAR(tty)){
147 			stop_tty(tty);
148 			return;
149 		}
150 		else if(ch == START_CHAR(tty)){
151 			start_tty(tty);
152 			return;
153 		}
154 	}
155 
156 	if((tty->flip.flag_buf_ptr == NULL) ||
157 	   (tty->flip.char_buf_ptr == NULL))
158 		return;
159 	tty_insert_flip_char(tty, ch, TTY_NORMAL);
160 }
161 
162 static int open_one_chan(struct chan *chan, int input, int output, int primary)
163 {
164 	int fd;
165 
166 	if(chan->opened) return(0);
167 	if(chan->ops->open == NULL) fd = 0;
168 	else fd = (*chan->ops->open)(input, output, primary, chan->data,
169 				     &chan->dev);
170 	if(fd < 0) return(fd);
171 	chan->fd = fd;
172 
173 	chan->opened = 1;
174 	return(0);
175 }
176 
177 int open_chan(struct list_head *chans)
178 {
179 	struct list_head *ele;
180 	struct chan *chan;
181 	int ret, err = 0;
182 
183 	list_for_each(ele, chans){
184 		chan = list_entry(ele, struct chan, list);
185 		ret = open_one_chan(chan, chan->input, chan->output,
186 				    chan->primary);
187 		if(chan->primary) err = ret;
188 	}
189 	return(err);
190 }
191 
192 void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
193 {
194 	struct list_head *ele;
195 	struct chan *chan;
196 
197 	list_for_each(ele, chans){
198 		chan = list_entry(ele, struct chan, list);
199 		if(chan->primary && chan->output && chan->ops->winch){
200 			register_winch(chan->fd, tty);
201 			return;
202 		}
203 	}
204 }
205 
206 void enable_chan(struct list_head *chans, struct tty_struct *tty)
207 {
208 	struct list_head *ele;
209 	struct chan *chan;
210 
211 	list_for_each(ele, chans){
212 		chan = list_entry(ele, struct chan, list);
213 		if(!chan->opened) continue;
214 
215 		line_setup_irq(chan->fd, chan->input, chan->output, tty);
216 	}
217 }
218 
219 void close_chan(struct list_head *chans)
220 {
221 	struct chan *chan;
222 
223 	/* Close in reverse order as open in case more than one of them
224 	 * refers to the same device and they save and restore that device's
225 	 * state.  Then, the first one opened will have the original state,
226 	 * so it must be the last closed.
227 	 */
228 	list_for_each_entry_reverse(chan, chans, list) {
229 		if(!chan->opened) continue;
230 		if(chan->ops->close != NULL)
231 			(*chan->ops->close)(chan->fd, chan->data);
232 		chan->opened = 0;
233 		chan->fd = -1;
234 	}
235 }
236 
237 int write_chan(struct list_head *chans, const char *buf, int len,
238 	       int write_irq)
239 {
240 	struct list_head *ele;
241 	struct chan *chan = NULL;
242 	int n, ret = 0;
243 
244 	list_for_each(ele, chans) {
245 		chan = list_entry(ele, struct chan, list);
246 		if (!chan->output || (chan->ops->write == NULL))
247 			continue;
248 		n = chan->ops->write(chan->fd, buf, len, chan->data);
249 		if (chan->primary) {
250 			ret = n;
251 			if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
252 				reactivate_fd(chan->fd, write_irq);
253 		}
254 	}
255 	return(ret);
256 }
257 
258 int console_write_chan(struct list_head *chans, const char *buf, int len)
259 {
260 	struct list_head *ele;
261 	struct chan *chan;
262 	int n, ret = 0;
263 
264 	list_for_each(ele, chans){
265 		chan = list_entry(ele, struct chan, list);
266 		if(!chan->output || (chan->ops->console_write == NULL))
267 			continue;
268 		n = chan->ops->console_write(chan->fd, buf, len, chan->data);
269 		if(chan->primary) ret = n;
270 	}
271 	return(ret);
272 }
273 
274 int console_open_chan(struct line *line, struct console *co, struct chan_opts *opts)
275 {
276 	if (!list_empty(&line->chan_list))
277 		return 0;
278 
279 	if (0 != parse_chan_pair(line->init_str, &line->chan_list,
280 				 line->init_pri, co->index, opts))
281 		return -1;
282 	if (0 != open_chan(&line->chan_list))
283 		return -1;
284 	printk("Console initialized on /dev/%s%d\n",co->name,co->index);
285 	return 0;
286 }
287 
288 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
289 		      unsigned short *cols_out)
290 {
291 	struct list_head *ele;
292 	struct chan *chan;
293 
294 	list_for_each(ele, chans){
295 		chan = list_entry(ele, struct chan, list);
296 		if(chan->primary){
297 			if(chan->ops->window_size == NULL) return(0);
298 			return(chan->ops->window_size(chan->fd, chan->data,
299 						      rows_out, cols_out));
300 		}
301 	}
302 	return(0);
303 }
304 
305 void free_one_chan(struct chan *chan)
306 {
307 	list_del(&chan->list);
308 	if(chan->ops->free != NULL)
309 		(*chan->ops->free)(chan->data);
310 	free_irq_by_fd(chan->fd);
311 	if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
312 	kfree(chan);
313 }
314 
315 void free_chan(struct list_head *chans)
316 {
317 	struct list_head *ele, *next;
318 	struct chan *chan;
319 
320 	list_for_each_safe(ele, next, chans){
321 		chan = list_entry(ele, struct chan, list);
322 		free_one_chan(chan);
323 	}
324 }
325 
326 static int one_chan_config_string(struct chan *chan, char *str, int size,
327 				  char **error_out)
328 {
329 	int n = 0;
330 
331 	if(chan == NULL){
332 		CONFIG_CHUNK(str, size, n, "none", 1);
333 		return(n);
334 	}
335 
336 	CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
337 
338 	if(chan->dev == NULL){
339 		CONFIG_CHUNK(str, size, n, "", 1);
340 		return(n);
341 	}
342 
343 	CONFIG_CHUNK(str, size, n, ":", 0);
344 	CONFIG_CHUNK(str, size, n, chan->dev, 0);
345 
346 	return(n);
347 }
348 
349 static int chan_pair_config_string(struct chan *in, struct chan *out,
350 				   char *str, int size, char **error_out)
351 {
352 	int n;
353 
354 	n = one_chan_config_string(in, str, size, error_out);
355 	str += n;
356 	size -= n;
357 
358 	if(in == out){
359 		CONFIG_CHUNK(str, size, n, "", 1);
360 		return(n);
361 	}
362 
363 	CONFIG_CHUNK(str, size, n, ",", 1);
364 	n = one_chan_config_string(out, str, size, error_out);
365 	str += n;
366 	size -= n;
367 	CONFIG_CHUNK(str, size, n, "", 1);
368 
369 	return(n);
370 }
371 
372 int chan_config_string(struct list_head *chans, char *str, int size,
373 		       char **error_out)
374 {
375 	struct list_head *ele;
376 	struct chan *chan, *in = NULL, *out = NULL;
377 
378 	list_for_each(ele, chans){
379 		chan = list_entry(ele, struct chan, list);
380 		if(!chan->primary)
381 			continue;
382 		if(chan->input)
383 			in = chan;
384 		if(chan->output)
385 			out = chan;
386 	}
387 
388 	return(chan_pair_config_string(in, out, str, size, error_out));
389 }
390 
391 struct chan_type {
392 	char *key;
393 	struct chan_ops *ops;
394 };
395 
396 struct chan_type chan_table[] = {
397 	{ "fd", &fd_ops },
398 
399 #ifdef CONFIG_NULL_CHAN
400 	{ "null", &null_ops },
401 #else
402 	{ "null", &not_configged_ops },
403 #endif
404 
405 #ifdef CONFIG_PORT_CHAN
406 	{ "port", &port_ops },
407 #else
408 	{ "port", &not_configged_ops },
409 #endif
410 
411 #ifdef CONFIG_PTY_CHAN
412 	{ "pty", &pty_ops },
413 	{ "pts", &pts_ops },
414 #else
415 	{ "pty", &not_configged_ops },
416 	{ "pts", &not_configged_ops },
417 #endif
418 
419 #ifdef CONFIG_TTY_CHAN
420 	{ "tty", &tty_ops },
421 #else
422 	{ "tty", &not_configged_ops },
423 #endif
424 
425 #ifdef CONFIG_XTERM_CHAN
426 	{ "xterm", &xterm_ops },
427 #else
428 	{ "xterm", &not_configged_ops },
429 #endif
430 };
431 
432 static struct chan *parse_chan(char *str, int pri, int device,
433 			       struct chan_opts *opts)
434 {
435 	struct chan_type *entry;
436 	struct chan_ops *ops;
437 	struct chan *chan;
438 	void *data;
439 	int i;
440 
441 	ops = NULL;
442 	data = NULL;
443 	for(i = 0; i < sizeof(chan_table)/sizeof(chan_table[0]); i++){
444 		entry = &chan_table[i];
445 		if(!strncmp(str, entry->key, strlen(entry->key))){
446 			ops = entry->ops;
447 			str += strlen(entry->key);
448 			break;
449 		}
450 	}
451 	if(ops == NULL){
452 		printk(KERN_ERR "parse_chan couldn't parse \"%s\"\n",
453 		       str);
454 		return(NULL);
455 	}
456 	if(ops->init == NULL) return(NULL);
457 	data = (*ops->init)(str, device, opts);
458 	if(data == NULL) return(NULL);
459 
460 	chan = kmalloc(sizeof(*chan), GFP_KERNEL);
461 	if(chan == NULL) return(NULL);
462 	*chan = ((struct chan) { .list	 	= LIST_HEAD_INIT(chan->list),
463 				 .primary	= 1,
464 				 .input		= 0,
465 				 .output 	= 0,
466 				 .opened  	= 0,
467 				 .fd 		= -1,
468 				 .pri 		= pri,
469 				 .ops 		= ops,
470 				 .data 		= data });
471 	return(chan);
472 }
473 
474 int parse_chan_pair(char *str, struct list_head *chans, int pri, int device,
475 		    struct chan_opts *opts)
476 {
477 	struct chan *new, *chan;
478 	char *in, *out;
479 
480 	if(!list_empty(chans)){
481 		chan = list_entry(chans->next, struct chan, list);
482 		if(chan->pri >= pri) return(0);
483 		free_chan(chans);
484 		INIT_LIST_HEAD(chans);
485 	}
486 
487 	out = strchr(str, ',');
488 	if(out != NULL){
489 		in = str;
490 		*out = '\0';
491 		out++;
492 		new = parse_chan(in, pri, device, opts);
493 		if(new == NULL) return(-1);
494 		new->input = 1;
495 		list_add(&new->list, chans);
496 
497 		new = parse_chan(out, pri, device, opts);
498 		if(new == NULL) return(-1);
499 		list_add(&new->list, chans);
500 		new->output = 1;
501 	}
502 	else {
503 		new = parse_chan(str, pri, device, opts);
504 		if(new == NULL) return(-1);
505 		list_add(&new->list, chans);
506 		new->input = 1;
507 		new->output = 1;
508 	}
509 	return(0);
510 }
511 
512 int chan_out_fd(struct list_head *chans)
513 {
514 	struct list_head *ele;
515 	struct chan *chan;
516 
517 	list_for_each(ele, chans){
518 		chan = list_entry(ele, struct chan, list);
519 		if(chan->primary && chan->output)
520 			return(chan->fd);
521 	}
522 	return(-1);
523 }
524 
525 void chan_interrupt(struct list_head *chans, struct work_struct *task,
526 		    struct tty_struct *tty, int irq)
527 {
528 	struct list_head *ele, *next;
529 	struct chan *chan;
530 	int err;
531 	char c;
532 
533 	list_for_each_safe(ele, next, chans){
534 		chan = list_entry(ele, struct chan, list);
535 		if(!chan->input || (chan->ops->read == NULL)) continue;
536 		do {
537 			if((tty != NULL) &&
538 			   (tty->flip.count >= TTY_FLIPBUF_SIZE)){
539 				schedule_work(task);
540 				goto out;
541 			}
542 			err = chan->ops->read(chan->fd, &c, chan->data);
543 			if(err > 0)
544 				tty_receive_char(tty, c);
545 		} while(err > 0);
546 
547 		if(err == 0) reactivate_fd(chan->fd, irq);
548 		if(err == -EIO){
549 			if(chan->primary){
550 				if(tty != NULL)
551 					tty_hangup(tty);
552 				line_disable(tty, irq);
553 				close_chan(chans);
554 				free_chan(chans);
555 				return;
556 			}
557 			else {
558 				if(chan->ops->close != NULL)
559 					chan->ops->close(chan->fd, chan->data);
560 				free_one_chan(chan);
561 			}
562 		}
563 	}
564  out:
565 	if(tty) tty_flip_buffer_push(tty);
566 }
567 
568 /*
569  * Overrides for Emacs so that we follow Linus's tabbing style.
570  * Emacs will notice this stuff at the end of the file and automatically
571  * adjust the settings for this buffer only.  This must remain at the end
572  * of the file.
573  * ---------------------------------------------------------------------------
574  * Local variables:
575  * c-file-style: "linux"
576  * End:
577  */
578