Merge branch 'server-cluster-locking-api' of git://linux-nfs.org/~bfields/linux
[linux-2.6] / arch / um / drivers / chan_kern.c
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 "kern.h"
16 #include "irq_user.h"
17 #include "sigio.h"
18 #include "line.h"
19 #include "os.h"
20
21 #ifdef CONFIG_NOCONFIG_CHAN
22 static void *not_configged_init(char *str, int device,
23                                 const struct chan_opts *opts)
24 {
25         printk("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("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("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("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("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 {
60         printk("Using a channel type which is configured out of "
61                "UML\n");
62         return -EIO;
63 }
64
65 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
66                                      unsigned short *cols)
67 {
68         printk("Using a channel type which is configured out of "
69                "UML\n");
70         return -ENODEV;
71 }
72
73 static void not_configged_free(void *data)
74 {
75         printk("Using a channel type which is configured out of "
76                "UML\n");
77 }
78
79 static const struct chan_ops not_configged_ops = {
80         .init           = not_configged_init,
81         .open           = not_configged_open,
82         .close          = not_configged_close,
83         .read           = not_configged_read,
84         .write          = not_configged_write,
85         .console_write  = not_configged_console_write,
86         .window_size    = not_configged_window_size,
87         .free           = not_configged_free,
88         .winch          = 0,
89 };
90 #endif /* CONFIG_NOCONFIG_CHAN */
91
92 void generic_close(int fd, void *unused)
93 {
94         os_close_file(fd);
95 }
96
97 int generic_read(int fd, char *c_out, void *unused)
98 {
99         int n;
100
101         n = os_read_file(fd, c_out, sizeof(*c_out));
102
103         if(n == -EAGAIN)
104                 return 0;
105         else if(n == 0)
106                 return -EIO;
107         return n;
108 }
109
110 /* XXX Trivial wrapper around os_write_file */
111
112 int generic_write(int fd, const char *buf, int n, void *unused)
113 {
114         return os_write_file(fd, buf, n);
115 }
116
117 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
118                         unsigned short *cols_out)
119 {
120         int rows, cols;
121         int ret;
122
123         ret = os_window_size(fd, &rows, &cols);
124         if(ret < 0)
125                 return ret;
126
127         ret = ((*rows_out != rows) || (*cols_out != cols));
128
129         *rows_out = rows;
130         *cols_out = cols;
131
132         return ret;
133 }
134
135 void generic_free(void *data)
136 {
137         kfree(data);
138 }
139
140 static void tty_receive_char(struct tty_struct *tty, char ch)
141 {
142         if(tty == NULL) return;
143
144         if(I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
145                 if(ch == STOP_CHAR(tty)){
146                         stop_tty(tty);
147                         return;
148                 }
149                 else if(ch == START_CHAR(tty)){
150                         start_tty(tty);
151                         return;
152                 }
153         }
154
155         tty_insert_flip_char(tty, ch, TTY_NORMAL);
156 }
157
158 static int open_one_chan(struct chan *chan)
159 {
160         int fd;
161
162         if(chan->opened)
163                 return 0;
164
165         if(chan->ops->open == NULL)
166                 fd = 0;
167         else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
168                                      chan->data, &chan->dev);
169         if(fd < 0)
170                 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);
186                 if(chan->primary)
187                         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 line *line)
207 {
208         struct list_head *ele;
209         struct chan *chan;
210
211         list_for_each(ele, &line->chan_list){
212                 chan = list_entry(ele, struct chan, list);
213                 if(open_one_chan(chan))
214                         continue;
215
216                 if(chan->enabled)
217                         continue;
218                 line_setup_irq(chan->fd, chan->input, chan->output, line,
219                                chan);
220                 chan->enabled = 1;
221         }
222 }
223
224 /* Items are added in IRQ context, when free_irq can't be called, and
225  * removed in process context, when it can.
226  * This handles interrupt sources which disappear, and which need to
227  * be permanently disabled.  This is discovered in IRQ context, but
228  * the freeing of the IRQ must be done later.
229  */
230 static DEFINE_SPINLOCK(irqs_to_free_lock);
231 static LIST_HEAD(irqs_to_free);
232
233 void free_irqs(void)
234 {
235         struct chan *chan;
236         LIST_HEAD(list);
237         struct list_head *ele;
238         unsigned long flags;
239
240         spin_lock_irqsave(&irqs_to_free_lock, flags);
241         list_splice_init(&irqs_to_free, &list);
242         spin_unlock_irqrestore(&irqs_to_free_lock, flags);
243
244         list_for_each(ele, &list){
245                 chan = list_entry(ele, struct chan, free_list);
246
247                 if(chan->input)
248                         free_irq(chan->line->driver->read_irq, chan);
249                 if(chan->output)
250                         free_irq(chan->line->driver->write_irq, chan);
251                 chan->enabled = 0;
252         }
253 }
254
255 static void close_one_chan(struct chan *chan, int delay_free_irq)
256 {
257         unsigned long flags;
258
259         if(!chan->opened)
260                 return;
261
262         if(delay_free_irq){
263                 spin_lock_irqsave(&irqs_to_free_lock, flags);
264                 list_add(&chan->free_list, &irqs_to_free);
265                 spin_unlock_irqrestore(&irqs_to_free_lock, flags);
266         }
267         else {
268                 if(chan->input)
269                         free_irq(chan->line->driver->read_irq, chan);
270                 if(chan->output)
271                         free_irq(chan->line->driver->write_irq, chan);
272                 chan->enabled = 0;
273         }
274         if(chan->ops->close != NULL)
275                 (*chan->ops->close)(chan->fd, chan->data);
276
277         chan->opened = 0;
278         chan->fd = -1;
279 }
280
281 void close_chan(struct list_head *chans, int delay_free_irq)
282 {
283         struct chan *chan;
284
285         /* Close in reverse order as open in case more than one of them
286          * refers to the same device and they save and restore that device's
287          * state.  Then, the first one opened will have the original state,
288          * so it must be the last closed.
289          */
290         list_for_each_entry_reverse(chan, chans, list) {
291                 close_one_chan(chan, delay_free_irq);
292         }
293 }
294
295 void deactivate_chan(struct list_head *chans, int irq)
296 {
297         struct list_head *ele;
298
299         struct chan *chan;
300         list_for_each(ele, chans) {
301                 chan = list_entry(ele, struct chan, list);
302
303                 if(chan->enabled && chan->input)
304                         deactivate_fd(chan->fd, irq);
305         }
306 }
307
308 void reactivate_chan(struct list_head *chans, int irq)
309 {
310         struct list_head *ele;
311         struct chan *chan;
312
313         list_for_each(ele, chans) {
314                 chan = list_entry(ele, struct chan, list);
315
316                 if(chan->enabled && chan->input)
317                         reactivate_fd(chan->fd, irq);
318         }
319 }
320
321 int write_chan(struct list_head *chans, const char *buf, int len,
322                int write_irq)
323 {
324         struct list_head *ele;
325         struct chan *chan = NULL;
326         int n, ret = 0;
327
328         list_for_each(ele, chans) {
329                 chan = list_entry(ele, struct chan, list);
330                 if (!chan->output || (chan->ops->write == NULL))
331                         continue;
332                 n = chan->ops->write(chan->fd, buf, len, chan->data);
333                 if (chan->primary) {
334                         ret = n;
335                         if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
336                                 reactivate_fd(chan->fd, write_irq);
337                 }
338         }
339         return ret;
340 }
341
342 int console_write_chan(struct list_head *chans, const char *buf, int len)
343 {
344         struct list_head *ele;
345         struct chan *chan;
346         int n, ret = 0;
347
348         list_for_each(ele, chans){
349                 chan = list_entry(ele, struct chan, list);
350                 if(!chan->output || (chan->ops->console_write == NULL))
351                         continue;
352                 n = chan->ops->console_write(chan->fd, buf, len);
353                 if(chan->primary) ret = n;
354         }
355         return ret;
356 }
357
358 int console_open_chan(struct line *line, struct console *co)
359 {
360         int err;
361
362         err = open_chan(&line->chan_list);
363         if(err)
364                 return err;
365
366         printk("Console initialized on /dev/%s%d\n", co->name, co->index);
367         return 0;
368 }
369
370 int chan_window_size(struct list_head *chans, unsigned short *rows_out,
371                       unsigned short *cols_out)
372 {
373         struct list_head *ele;
374         struct chan *chan;
375
376         list_for_each(ele, chans){
377                 chan = list_entry(ele, struct chan, list);
378                 if(chan->primary){
379                         if(chan->ops->window_size == NULL)
380                                 return 0;
381                         return chan->ops->window_size(chan->fd, chan->data,
382                                                       rows_out, cols_out);
383                 }
384         }
385         return 0;
386 }
387
388 static void free_one_chan(struct chan *chan, int delay_free_irq)
389 {
390         list_del(&chan->list);
391
392         close_one_chan(chan, delay_free_irq);
393
394         if(chan->ops->free != NULL)
395                 (*chan->ops->free)(chan->data);
396
397         if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
398         kfree(chan);
399 }
400
401 static void free_chan(struct list_head *chans, int delay_free_irq)
402 {
403         struct list_head *ele, *next;
404         struct chan *chan;
405
406         list_for_each_safe(ele, next, chans){
407                 chan = list_entry(ele, struct chan, list);
408                 free_one_chan(chan, delay_free_irq);
409         }
410 }
411
412 static int one_chan_config_string(struct chan *chan, char *str, int size,
413                                   char **error_out)
414 {
415         int n = 0;
416
417         if(chan == NULL){
418                 CONFIG_CHUNK(str, size, n, "none", 1);
419                 return n;
420         }
421
422         CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
423
424         if(chan->dev == NULL){
425                 CONFIG_CHUNK(str, size, n, "", 1);
426                 return n;
427         }
428
429         CONFIG_CHUNK(str, size, n, ":", 0);
430         CONFIG_CHUNK(str, size, n, chan->dev, 0);
431
432         return n;
433 }
434
435 static int chan_pair_config_string(struct chan *in, struct chan *out,
436                                    char *str, int size, char **error_out)
437 {
438         int n;
439
440         n = one_chan_config_string(in, str, size, error_out);
441         str += n;
442         size -= n;
443
444         if(in == out){
445                 CONFIG_CHUNK(str, size, n, "", 1);
446                 return n;
447         }
448
449         CONFIG_CHUNK(str, size, n, ",", 1);
450         n = one_chan_config_string(out, str, size, error_out);
451         str += n;
452         size -= n;
453         CONFIG_CHUNK(str, size, n, "", 1);
454
455         return n;
456 }
457
458 int chan_config_string(struct list_head *chans, char *str, int size,
459                        char **error_out)
460 {
461         struct list_head *ele;
462         struct chan *chan, *in = NULL, *out = NULL;
463
464         list_for_each(ele, chans){
465                 chan = list_entry(ele, struct chan, list);
466                 if(!chan->primary)
467                         continue;
468                 if(chan->input)
469                         in = chan;
470                 if(chan->output)
471                         out = chan;
472         }
473
474         return chan_pair_config_string(in, out, str, size, error_out);
475 }
476
477 struct chan_type {
478         char *key;
479         const struct chan_ops *ops;
480 };
481
482 static const struct chan_type chan_table[] = {
483         { "fd", &fd_ops },
484
485 #ifdef CONFIG_NULL_CHAN
486         { "null", &null_ops },
487 #else
488         { "null", &not_configged_ops },
489 #endif
490
491 #ifdef CONFIG_PORT_CHAN
492         { "port", &port_ops },
493 #else
494         { "port", &not_configged_ops },
495 #endif
496
497 #ifdef CONFIG_PTY_CHAN
498         { "pty", &pty_ops },
499         { "pts", &pts_ops },
500 #else
501         { "pty", &not_configged_ops },
502         { "pts", &not_configged_ops },
503 #endif
504
505 #ifdef CONFIG_TTY_CHAN
506         { "tty", &tty_ops },
507 #else
508         { "tty", &not_configged_ops },
509 #endif
510
511 #ifdef CONFIG_XTERM_CHAN
512         { "xterm", &xterm_ops },
513 #else
514         { "xterm", &not_configged_ops },
515 #endif
516 };
517
518 static struct chan *parse_chan(struct line *line, char *str, int device,
519                                const struct chan_opts *opts, char **error_out)
520 {
521         const struct chan_type *entry;
522         const struct chan_ops *ops;
523         struct chan *chan;
524         void *data;
525         int i;
526
527         ops = NULL;
528         data = NULL;
529         for(i = 0; i < ARRAY_SIZE(chan_table); i++){
530                 entry = &chan_table[i];
531                 if(!strncmp(str, entry->key, strlen(entry->key))){
532                         ops = entry->ops;
533                         str += strlen(entry->key);
534                         break;
535                 }
536         }
537         if(ops == NULL){
538                 *error_out = "No match for configured backends";
539                 return NULL;
540         }
541
542         data = (*ops->init)(str, device, opts);
543         if(data == NULL){
544                 *error_out = "Configuration failed";
545                 return NULL;
546         }
547
548         chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
549         if(chan == NULL){
550                 *error_out = "Memory allocation failed";
551                 return NULL;
552         }
553         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
554                                  .free_list     =
555                                         LIST_HEAD_INIT(chan->free_list),
556                                  .line          = line,
557                                  .primary       = 1,
558                                  .input         = 0,
559                                  .output        = 0,
560                                  .opened        = 0,
561                                  .enabled       = 0,
562                                  .fd            = -1,
563                                  .ops           = ops,
564                                  .data          = data });
565         return chan;
566 }
567
568 int parse_chan_pair(char *str, struct line *line, int device,
569                     const struct chan_opts *opts, char **error_out)
570 {
571         struct list_head *chans = &line->chan_list;
572         struct chan *new, *chan;
573         char *in, *out;
574
575         if(!list_empty(chans)){
576                 chan = list_entry(chans->next, struct chan, list);
577                 free_chan(chans, 0);
578                 INIT_LIST_HEAD(chans);
579         }
580
581         out = strchr(str, ',');
582         if(out != NULL){
583                 in = str;
584                 *out = '\0';
585                 out++;
586                 new = parse_chan(line, in, device, opts, error_out);
587                 if(new == NULL)
588                         return -1;
589
590                 new->input = 1;
591                 list_add(&new->list, chans);
592
593                 new = parse_chan(line, out, device, opts, error_out);
594                 if(new == NULL)
595                         return -1;
596
597                 list_add(&new->list, chans);
598                 new->output = 1;
599         }
600         else {
601                 new = parse_chan(line, str, device, opts, error_out);
602                 if(new == NULL)
603                         return -1;
604
605                 list_add(&new->list, chans);
606                 new->input = 1;
607                 new->output = 1;
608         }
609         return 0;
610 }
611
612 int chan_out_fd(struct list_head *chans)
613 {
614         struct list_head *ele;
615         struct chan *chan;
616
617         list_for_each(ele, chans){
618                 chan = list_entry(ele, struct chan, list);
619                 if(chan->primary && chan->output)
620                         return chan->fd;
621         }
622         return -1;
623 }
624
625 void chan_interrupt(struct list_head *chans, struct delayed_work *task,
626                     struct tty_struct *tty, int irq)
627 {
628         struct list_head *ele, *next;
629         struct chan *chan;
630         int err;
631         char c;
632
633         list_for_each_safe(ele, next, chans){
634                 chan = list_entry(ele, struct chan, list);
635                 if(!chan->input || (chan->ops->read == NULL)) continue;
636                 do {
637                         if (tty && !tty_buffer_request_room(tty, 1)) {
638                                 schedule_delayed_work(task, 1);
639                                 goto out;
640                         }
641                         err = chan->ops->read(chan->fd, &c, chan->data);
642                         if(err > 0)
643                                 tty_receive_char(tty, c);
644                 } while(err > 0);
645
646                 if(err == 0) reactivate_fd(chan->fd, irq);
647                 if(err == -EIO){
648                         if(chan->primary){
649                                 if(tty != NULL)
650                                         tty_hangup(tty);
651                                 close_chan(chans, 1);
652                                 return;
653                         }
654                         else close_one_chan(chan, 1);
655                 }
656         }
657  out:
658         if(tty) tty_flip_buffer_push(tty);
659 }