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[XFRM]: skb_cow_data() does not set proper owner for new skbs.
[linux-2.6/verdex.git] / drivers / char / n_r3964.c
blob3883073ab48f556e4d080b6721a2b194bdce9250
1 /* r3964 linediscipline for linux
2 *
3 * -----------------------------------------------------------
4 * Copyright by
5 * Philips Automation Projects
6 * Kassel (Germany)
7 * http://www.pap-philips.de
8 * -----------------------------------------------------------
9 * This software may be used and distributed according to the terms of
10 * the GNU General Public License, incorporated herein by reference.
11 *
12 * Author:
13 * L. Haag
14 *
15 * $Log: n_r3964.c,v $
16 * Revision 1.10 2001/03/18 13:02:24 dwmw2
17 * Fix timer usage, use spinlocks properly.
18 *
19 * Revision 1.9 2001/03/18 12:52:14 dwmw2
20 * Merge changes in 2.4.2
21 *
22 * Revision 1.8 2000/03/23 14:14:54 dwmw2
23 * Fix race in sleeping in r3964_read()
24 *
25 * Revision 1.7 1999/28/08 11:41:50 dwmw2
26 * Port to 2.3 kernel
27 *
28 * Revision 1.6 1998/09/30 00:40:40 dwmw2
29 * Fixed compilation on 2.0.x kernels
30 * Updated to newly registered tty-ldisc number 9
31 *
32 * Revision 1.5 1998/09/04 21:57:36 dwmw2
33 * Signal handling bug fixes, port to 2.1.x.
34 *
35 * Revision 1.4 1998/04/02 20:26:59 lhaag
36 * select, blocking, ...
37 *
38 * Revision 1.3 1998/02/12 18:58:43 root
39 * fixed some memory leaks
40 * calculation of checksum characters
41 *
42 * Revision 1.2 1998/02/07 13:03:34 root
43 * ioctl read_telegram
44 *
45 * Revision 1.1 1998/02/06 19:21:03 root
46 * Initial revision
47 *
48 *
49 */
50
51 #include <linux/module.h>
52 #include <linux/kernel.h>
53 #include <linux/sched.h>
54 #include <linux/types.h>
55 #include <linux/fcntl.h>
56 #include <linux/interrupt.h>
57 #include <linux/ptrace.h>
58 #include <linux/ioport.h>
59 #include <linux/in.h>
60 #include <linux/slab.h>
61 #include <linux/tty.h>
62 #include <linux/errno.h>
63 #include <linux/string.h> /* used in new tty drivers */
64 #include <linux/signal.h> /* used in new tty drivers */
65 #include <linux/ioctl.h>
66 #include <linux/n_r3964.h>
67 #include <linux/poll.h>
68 #include <linux/init.h>
69 #include <asm/uaccess.h>
70
71
72 //#define DEBUG_QUEUE
73
74 /* Log successful handshake and protocol operations */
75 //#define DEBUG_PROTO_S
76
77 /* Log handshake and protocol errors: */
78 //#define DEBUG_PROTO_E
79
80 /* Log Linediscipline operations (open, close, read, write...): */
81 //#define DEBUG_LDISC
82
83 /* Log module and memory operations (init, cleanup; kmalloc, kfree): */
84 //#define DEBUG_MODUL
85
86 /* Macro helpers for debug output: */
87 #define TRACE(format, args...) printk("r3964: " format "\n" , ## args);
88
89 #ifdef DEBUG_MODUL
90 #define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args);
91 #else
92 #define TRACE_M(fmt, arg...) /**/
93 #endif
94
95 #ifdef DEBUG_PROTO_S
96 #define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args);
97 #else
98 #define TRACE_PS(fmt, arg...) /**/
99 #endif
100
101 #ifdef DEBUG_PROTO_E
102 #define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args);
103 #else
104 #define TRACE_PE(fmt, arg...) /**/
105 #endif
106
107 #ifdef DEBUG_LDISC
108 #define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args);
109 #else
110 #define TRACE_L(fmt, arg...) /**/
111 #endif
112
113 #ifdef DEBUG_QUEUE
114 #define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args);
115 #else
116 #define TRACE_Q(fmt, arg...) /**/
117 #endif
118
119 static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
120 static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
121 static void put_char(struct r3964_info *pInfo, unsigned char ch);
122 static void trigger_transmit(struct r3964_info *pInfo);
123 static void retry_transmit(struct r3964_info *pInfo);
124 static void transmit_block(struct r3964_info *pInfo);
125 static void receive_char(struct r3964_info *pInfo, const unsigned char c);
126 static void receive_error(struct r3964_info *pInfo, const char flag);
127 static void on_timeout(unsigned long priv);
128 static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg);
129 static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char __user *buf);
130 static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
131 int error_code, struct r3964_block_header *pBlock);
132 static struct r3964_message* remove_msg(struct r3964_info *pInfo,
133 struct r3964_client_info *pClient);
134 static void remove_client_block(struct r3964_info *pInfo,
135 struct r3964_client_info *pClient);
136
137 static int r3964_open(struct tty_struct *tty);
138 static void r3964_close(struct tty_struct *tty);
139 static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
140 unsigned char __user *buf, size_t nr);
141 static ssize_t r3964_write(struct tty_struct * tty, struct file * file,
142 const unsigned char * buf, size_t nr);
143 static int r3964_ioctl(struct tty_struct * tty, struct file * file,
144 unsigned int cmd, unsigned long arg);
145 static void r3964_set_termios(struct tty_struct *tty, struct termios * old);
146 static unsigned int r3964_poll(struct tty_struct * tty, struct file * file,
147 struct poll_table_struct *wait);
148 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
149 char *fp, int count);
150 static int r3964_receive_room(struct tty_struct *tty);
151
152 static struct tty_ldisc tty_ldisc_N_R3964 = {
153 .owner = THIS_MODULE,
154 .magic = TTY_LDISC_MAGIC,
155 .name = "R3964",
156 .open = r3964_open,
157 .close = r3964_close,
158 .read = r3964_read,
159 .write = r3964_write,
160 .ioctl = r3964_ioctl,
161 .set_termios = r3964_set_termios,
162 .poll = r3964_poll,
163 .receive_buf = r3964_receive_buf,
164 .receive_room = r3964_receive_room,
165 };
166
167
168
169 static void dump_block(const unsigned char *block, unsigned int length)
170 {
171 unsigned int i,j;
172 char linebuf[16*3+1];
173
174 for(i=0;i<length;i+=16)
175 {
176 for(j=0;(j<16) && (j+i<length);j++)
177 {
178 sprintf(linebuf+3*j,"%02x ",block[i+j]);
179 }
180 linebuf[3*j]='\0';
181 TRACE_PS("%s",linebuf);
182 }
183 }
184
185
186
187
188 /*************************************************************
189 * Driver initialisation
190 *************************************************************/
191
192
193 /*************************************************************
194 * Module support routines
195 *************************************************************/
196
197 static void __exit r3964_exit(void)
198 {
199 int status;
200
201 TRACE_M ("cleanup_module()");
202
203 status=tty_register_ldisc(N_R3964, NULL);
204
205 if(status!=0)
206 {
207 printk(KERN_ERR "r3964: error unregistering linediscipline: %d\n", status);
208 }
209 else
210 {
211 TRACE_L("linediscipline successfully unregistered");
212 }
213
214 }
215
216 static int __init r3964_init(void)
217 {
218 int status;
219
220 printk ("r3964: Philips r3964 Driver $Revision: 1.10 $\n");
221
222 /*
223 * Register the tty line discipline
224 */
225
226 status = tty_register_ldisc (N_R3964, &tty_ldisc_N_R3964);
227 if (status == 0)
228 {
229 TRACE_L("line discipline %d registered", N_R3964);
230 TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags,
231 tty_ldisc_N_R3964.num);
232 TRACE_L("open=%x", (int)tty_ldisc_N_R3964.open);
233 TRACE_L("tty_ldisc_N_R3964 = %x", (int)&tty_ldisc_N_R3964);
234 }
235 else
236 {
237 printk (KERN_ERR "r3964: error registering line discipline: %d\n", status);
238 }
239 return status;
240 }
241
242 module_init(r3964_init);
243 module_exit(r3964_exit);
244
245
246 /*************************************************************
247 * Protocol implementation routines
248 *************************************************************/
249
250 static void add_tx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader)
251 {
252 unsigned long flags;
253
254 spin_lock_irqsave(&pInfo->lock, flags);
255
256 pHeader->next = NULL;
257
258 if(pInfo->tx_last == NULL)
259 {
260 pInfo->tx_first = pInfo->tx_last = pHeader;
261 }
262 else
263 {
264 pInfo->tx_last->next = pHeader;
265 pInfo->tx_last = pHeader;
266 }
267
268 spin_unlock_irqrestore(&pInfo->lock, flags);
269
270 TRACE_Q("add_tx_queue %x, length %d, tx_first = %x",
271 (int)pHeader, pHeader->length, (int)pInfo->tx_first );
272 }
273
274 static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
275 {
276 struct r3964_block_header *pHeader;
277 unsigned long flags;
278 #ifdef DEBUG_QUEUE
279 struct r3964_block_header *pDump;
280 #endif
281
282 pHeader = pInfo->tx_first;
283
284 if(pHeader==NULL)
285 return;
286
287 #ifdef DEBUG_QUEUE
288 printk("r3964: remove_from_tx_queue: %x, length %d - ",
289 (int)pHeader, (int)pHeader->length );
290 for(pDump=pHeader;pDump;pDump=pDump->next)
291 printk("%x ", (int)pDump);
292 printk("\n");
293 #endif
294
295
296 if(pHeader->owner)
297 {
298 if(error_code)
299 {
300 add_msg(pHeader->owner, R3964_MSG_ACK, 0,
301 error_code, NULL);
302 }
303 else
304 {
305 add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
306 error_code, NULL);
307 }
308 wake_up_interruptible (&pInfo->read_wait);
309 }
310
311 spin_lock_irqsave(&pInfo->lock, flags);
312
313 pInfo->tx_first = pHeader->next;
314 if(pInfo->tx_first==NULL)
315 {
316 pInfo->tx_last = NULL;
317 }
318
319 spin_unlock_irqrestore(&pInfo->lock, flags);
320
321 kfree(pHeader);
322 TRACE_M("remove_from_tx_queue - kfree %x",(int)pHeader);
323
324 TRACE_Q("remove_from_tx_queue: tx_first = %x, tx_last = %x",
325 (int)pInfo->tx_first, (int)pInfo->tx_last );
326 }
327
328 static void add_rx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader)
329 {
330 unsigned long flags;
331
332 spin_lock_irqsave(&pInfo->lock, flags);
333
334 pHeader->next = NULL;
335
336 if(pInfo->rx_last == NULL)
337 {
338 pInfo->rx_first = pInfo->rx_last = pHeader;
339 }
340 else
341 {
342 pInfo->rx_last->next = pHeader;
343 pInfo->rx_last = pHeader;
344 }
345 pInfo->blocks_in_rx_queue++;
346
347 spin_unlock_irqrestore(&pInfo->lock, flags);
348
349 TRACE_Q("add_rx_queue: %x, length = %d, rx_first = %x, count = %d",
350 (int)pHeader, pHeader->length,
351 (int)pInfo->rx_first, pInfo->blocks_in_rx_queue);
352 }
353
354 static void remove_from_rx_queue(struct r3964_info *pInfo,
355 struct r3964_block_header *pHeader)
356 {
357 unsigned long flags;
358 struct r3964_block_header *pFind;
359
360 if(pHeader==NULL)
361 return;
362
363 TRACE_Q("remove_from_rx_queue: rx_first = %x, rx_last = %x, count = %d",
364 (int)pInfo->rx_first, (int)pInfo->rx_last, pInfo->blocks_in_rx_queue );
365 TRACE_Q("remove_from_rx_queue: %x, length %d",
366 (int)pHeader, (int)pHeader->length );
367
368 spin_lock_irqsave(&pInfo->lock, flags);
369
370 if(pInfo->rx_first == pHeader)
371 {
372 /* Remove the first block in the linked list: */
373 pInfo->rx_first = pHeader->next;
374
375 if(pInfo->rx_first==NULL)
376 {
377 pInfo->rx_last = NULL;
378 }
379 pInfo->blocks_in_rx_queue--;
380 }
381 else
382 {
383 /* Find block to remove: */
384 for(pFind=pInfo->rx_first; pFind; pFind=pFind->next)
385 {
386 if(pFind->next == pHeader)
387 {
388 /* Got it. */
389 pFind->next = pHeader->next;
390 pInfo->blocks_in_rx_queue--;
391 if(pFind->next==NULL)
392 {
393 /* Oh, removed the last one! */
394 pInfo->rx_last = pFind;
395 }
396 break;
397 }
398 }
399 }
400
401 spin_unlock_irqrestore(&pInfo->lock, flags);
402
403 kfree(pHeader);
404 TRACE_M("remove_from_rx_queue - kfree %x",(int)pHeader);
405
406 TRACE_Q("remove_from_rx_queue: rx_first = %x, rx_last = %x, count = %d",
407 (int)pInfo->rx_first, (int)pInfo->rx_last, pInfo->blocks_in_rx_queue );
408 }
409
410 static void put_char(struct r3964_info *pInfo, unsigned char ch)
411 {
412 struct tty_struct *tty = pInfo->tty;
413
414 if(tty==NULL)
415 return;
416
417 if(tty->driver->put_char)
418 {
419 tty->driver->put_char(tty, ch);
420 }
421 pInfo->bcc ^= ch;
422 }
423
424 static void flush(struct r3964_info *pInfo)
425 {
426 struct tty_struct *tty = pInfo->tty;
427
428 if(tty==NULL)
429 return;
430
431 if(tty->driver->flush_chars)
432 {
433 tty->driver->flush_chars(tty);
434 }
435 }
436
437 static void trigger_transmit(struct r3964_info *pInfo)
438 {
439 unsigned long flags;
440
441
442 spin_lock_irqsave(&pInfo->lock, flags);
443
444 if((pInfo->state == R3964_IDLE) && (pInfo->tx_first!=NULL))
445 {
446 pInfo->state = R3964_TX_REQUEST;
447 pInfo->nRetry=0;
448 pInfo->flags &= ~R3964_ERROR;
449 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
450
451 spin_unlock_irqrestore(&pInfo->lock, flags);
452
453 TRACE_PS("trigger_transmit - sent STX");
454
455 put_char(pInfo, STX);
456 flush(pInfo);
457
458 pInfo->bcc = 0;
459 }
460 else
461 {
462 spin_unlock_irqrestore(&pInfo->lock, flags);
463 }
464 }
465
466 static void retry_transmit(struct r3964_info *pInfo)
467 {
468 if(pInfo->nRetry<R3964_MAX_RETRIES)
469 {
470 TRACE_PE("transmission failed. Retry #%d",
471 pInfo->nRetry);
472 pInfo->bcc = 0;
473 put_char(pInfo, STX);
474 flush(pInfo);
475 pInfo->state = R3964_TX_REQUEST;
476 pInfo->nRetry++;
477 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
478 }
479 else
480 {
481 TRACE_PE("transmission failed after %d retries",
482 R3964_MAX_RETRIES);
483
484 remove_from_tx_queue(pInfo, R3964_TX_FAIL);
485
486 put_char(pInfo, NAK);
487 flush(pInfo);
488 pInfo->state = R3964_IDLE;
489
490 trigger_transmit(pInfo);
491 }
492 }
493
494
495 static void transmit_block(struct r3964_info *pInfo)
496 {
497 struct tty_struct *tty = pInfo->tty;
498 struct r3964_block_header *pBlock = pInfo->tx_first;
499 int room=0;
500
501 if((tty==NULL) || (pBlock==NULL))
502 {
503 return;
504 }
505
506 if(tty->driver->write_room)
507 room=tty->driver->write_room(tty);
508
509 TRACE_PS("transmit_block %x, room %d, length %d",
510 (int)pBlock, room, pBlock->length);
511
512 while(pInfo->tx_position < pBlock->length)
513 {
514 if(room<2)
515 break;
516
517 if(pBlock->data[pInfo->tx_position]==DLE)
518 {
519 /* send additional DLE char: */
520 put_char(pInfo, DLE);
521 }
522 put_char(pInfo, pBlock->data[pInfo->tx_position++]);
523
524 room--;
525 }
526
527 if((pInfo->tx_position == pBlock->length) && (room>=3))
528 {
529 put_char(pInfo, DLE);
530 put_char(pInfo, ETX);
531 if(pInfo->flags & R3964_BCC)
532 {
533 put_char(pInfo, pInfo->bcc);
534 }
535 pInfo->state = R3964_WAIT_FOR_TX_ACK;
536 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
537 }
538 flush(pInfo);
539 }
540
541 static void on_receive_block(struct r3964_info *pInfo)
542 {
543 unsigned int length;
544 struct r3964_client_info *pClient;
545 struct r3964_block_header *pBlock;
546
547 length=pInfo->rx_position;
548
549 /* compare byte checksum characters: */
550 if(pInfo->flags & R3964_BCC)
551 {
552 if(pInfo->bcc!=pInfo->last_rx)
553 {
554 TRACE_PE("checksum error - got %x but expected %x",
555 pInfo->last_rx, pInfo->bcc);
556 pInfo->flags |= R3964_CHECKSUM;
557 }
558 }
559
560 /* check for errors (parity, overrun,...): */
561 if(pInfo->flags & R3964_ERROR)
562 {
563 TRACE_PE("on_receive_block - transmission failed error %x",
564 pInfo->flags & R3964_ERROR);
565
566 put_char(pInfo, NAK);
567 flush(pInfo);
568 if(pInfo->nRetry<R3964_MAX_RETRIES)
569 {
570 pInfo->state=R3964_WAIT_FOR_RX_REPEAT;
571 pInfo->nRetry++;
572 mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
573 }
574 else
575 {
576 TRACE_PE("on_receive_block - failed after max retries");
577 pInfo->state=R3964_IDLE;
578 }
579 return;
580 }
581
582
583 /* received block; submit DLE: */
584 put_char(pInfo, DLE);
585 flush(pInfo);
586 del_timer_sync(&pInfo->tmr);
587 TRACE_PS(" rx success: got %d chars", length);
588
589 /* prepare struct r3964_block_header: */
590 pBlock = kmalloc(length+sizeof(struct r3964_block_header), GFP_KERNEL);
591 TRACE_M("on_receive_block - kmalloc %x",(int)pBlock);
592
593 if(pBlock==NULL)
594 return;
595
596 pBlock->length = length;
597 pBlock->data = ((unsigned char*)pBlock)+sizeof(struct r3964_block_header);
598 pBlock->locks = 0;
599 pBlock->next = NULL;
600 pBlock->owner = NULL;
601
602 memcpy(pBlock->data, pInfo->rx_buf, length);
603
604 /* queue block into rx_queue: */
605 add_rx_queue(pInfo, pBlock);
606
607 /* notify attached client processes: */
608 for(pClient=pInfo->firstClient; pClient; pClient=pClient->next)
609 {
610 if(pClient->sig_flags & R3964_SIG_DATA)
611 {
612 add_msg(pClient, R3964_MSG_DATA, length, R3964_OK, pBlock);
613 }
614 }
615 wake_up_interruptible (&pInfo->read_wait);
616
617 pInfo->state = R3964_IDLE;
618
619 trigger_transmit(pInfo);
620 }
621
622
623 static void receive_char(struct r3964_info *pInfo, const unsigned char c)
624 {
625 switch(pInfo->state)
626 {
627 case R3964_TX_REQUEST:
628 if(c==DLE)
629 {
630 TRACE_PS("TX_REQUEST - got DLE");
631
632 pInfo->state = R3964_TRANSMITTING;
633 pInfo->tx_position = 0;
634
635 transmit_block(pInfo);
636 }
637 else if(c==STX)
638 {
639 if(pInfo->nRetry==0)
640 {
641 TRACE_PE("TX_REQUEST - init conflict");
642 if(pInfo->priority == R3964_SLAVE)
643 {
644 goto start_receiving;
645 }
646 }
647 else
648 {
649 TRACE_PE("TX_REQUEST - secondary init conflict!?"
650 " Switching to SLAVE mode for next rx.");
651 goto start_receiving;
652 }
653 }
654 else
655 {
656 TRACE_PE("TX_REQUEST - char != DLE: %x", c);
657 retry_transmit(pInfo);
658 }
659 break;
660 case R3964_TRANSMITTING:
661 if(c==NAK)
662 {
663 TRACE_PE("TRANSMITTING - got NAK");
664 retry_transmit(pInfo);
665 }
666 else
667 {
668 TRACE_PE("TRANSMITTING - got invalid char");
669
670 pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
671 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
672 }
673 break;
674 case R3964_WAIT_FOR_TX_ACK:
675 if(c==DLE)
676 {
677 TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
678 remove_from_tx_queue(pInfo, R3964_OK);
679
680 pInfo->state = R3964_IDLE;
681 trigger_transmit(pInfo);
682 }
683 else
684 {
685 retry_transmit(pInfo);
686 }
687 break;
688 case R3964_WAIT_FOR_RX_REPEAT:
689 /* FALLTROUGH */
690 case R3964_IDLE:
691 if(c==STX)
692 {
693 /* Prevent rx_queue from overflow: */
694 if(pInfo->blocks_in_rx_queue >= R3964_MAX_BLOCKS_IN_RX_QUEUE)
695 {
696 TRACE_PE("IDLE - got STX but no space in rx_queue!");
697 pInfo->state=R3964_WAIT_FOR_RX_BUF;
698 mod_timer(&pInfo->tmr, R3964_TO_NO_BUF);
699 break;
700 }
701 start_receiving:
702 /* Ok, start receiving: */
703 TRACE_PS("IDLE - got STX");
704 pInfo->rx_position = 0;
705 pInfo->last_rx = 0;
706 pInfo->flags &= ~R3964_ERROR;
707 pInfo->state=R3964_RECEIVING;
708 mod_timer(&pInfo->tmr, R3964_TO_ZVZ);
709 pInfo->nRetry = 0;
710 put_char(pInfo, DLE);
711 flush(pInfo);
712 pInfo->bcc = 0;
713 }
714 break;
715 case R3964_RECEIVING:
716 if(pInfo->rx_position < RX_BUF_SIZE)
717 {
718 pInfo->bcc ^= c;
719
720 if(c==DLE)
721 {
722 if(pInfo->last_rx==DLE)
723 {
724 pInfo->last_rx = 0;
725 goto char_to_buf;
726 }
727 pInfo->last_rx = DLE;
728 break;
729 }
730 else if((c==ETX) && (pInfo->last_rx==DLE))
731 {
732 if(pInfo->flags & R3964_BCC)
733 {
734 pInfo->state = R3964_WAIT_FOR_BCC;
735 mod_timer(&pInfo->tmr, R3964_TO_ZVZ);
736 }
737 else
738 {
739 on_receive_block(pInfo);
740 }
741 }
742 else
743 {
744 pInfo->last_rx = c;
745 char_to_buf:
746 pInfo->rx_buf[pInfo->rx_position++] = c;
747 mod_timer(&pInfo->tmr, R3964_TO_ZVZ);
748 }
749 }
750 /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
751 break;
752 case R3964_WAIT_FOR_BCC:
753 pInfo->last_rx = c;
754 on_receive_block(pInfo);
755 break;
756 }
757 }
758
759 static void receive_error(struct r3964_info *pInfo, const char flag)
760 {
761 switch (flag)
762 {
763 case TTY_NORMAL:
764 break;
765 case TTY_BREAK:
766 TRACE_PE("received break")
767 pInfo->flags |= R3964_BREAK;
768 break;
769 case TTY_PARITY:
770 TRACE_PE("parity error")
771 pInfo->flags |= R3964_PARITY;
772 break;
773 case TTY_FRAME:
774 TRACE_PE("frame error")
775 pInfo->flags |= R3964_FRAME;
776 break;
777 case TTY_OVERRUN:
778 TRACE_PE("frame overrun")
779 pInfo->flags |= R3964_OVERRUN;
780 break;
781 default:
782 TRACE_PE("receive_error - unknown flag %d", flag);
783 pInfo->flags |= R3964_UNKNOWN;
784 break;
785 }
786 }
787
788 static void on_timeout(unsigned long priv)
789 {
790 struct r3964_info *pInfo = (void *)priv;
791
792 switch(pInfo->state)
793 {
794 case R3964_TX_REQUEST:
795 TRACE_PE("TX_REQUEST - timeout");
796 retry_transmit(pInfo);
797 break;
798 case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
799 put_char(pInfo, NAK);
800 flush(pInfo);
801 retry_transmit(pInfo);
802 break;
803 case R3964_WAIT_FOR_TX_ACK:
804 TRACE_PE("WAIT_FOR_TX_ACK - timeout");
805 retry_transmit(pInfo);
806 break;
807 case R3964_WAIT_FOR_RX_BUF:
808 TRACE_PE("WAIT_FOR_RX_BUF - timeout");
809 put_char(pInfo, NAK);
810 flush(pInfo);
811 pInfo->state=R3964_IDLE;
812 break;
813 case R3964_RECEIVING:
814 TRACE_PE("RECEIVING - timeout after %d chars",
815 pInfo->rx_position);
816 put_char(pInfo, NAK);
817 flush(pInfo);
818 pInfo->state=R3964_IDLE;
819 break;
820 case R3964_WAIT_FOR_RX_REPEAT:
821 TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
822 pInfo->state=R3964_IDLE;
823 break;
824 case R3964_WAIT_FOR_BCC:
825 TRACE_PE("WAIT_FOR_BCC - timeout");
826 put_char(pInfo, NAK);
827 flush(pInfo);
828 pInfo->state=R3964_IDLE;
829 break;
830 }
831 }
832
833 static struct r3964_client_info *findClient(
834 struct r3964_info *pInfo, pid_t pid)
835 {
836 struct r3964_client_info *pClient;
837
838 for(pClient=pInfo->firstClient; pClient; pClient=pClient->next)
839 {
840 if(pClient->pid == pid)
841 {
842 return pClient;
843 }
844 }
845 return NULL;
846 }
847
848 static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg)
849 {
850 struct r3964_client_info *pClient;
851 struct r3964_client_info **ppClient;
852 struct r3964_message *pMsg;
853
854 if((arg & R3964_SIG_ALL)==0)
855 {
856 /* Remove client from client list */
857 for(ppClient=&pInfo->firstClient; *ppClient; ppClient=&(*ppClient)->next)
858 {
859 pClient = *ppClient;
860
861 if(pClient->pid == pid)
862 {
863 TRACE_PS("removing client %d from client list", pid);
864 *ppClient = pClient->next;
865 while(pClient->msg_count)
866 {
867 pMsg=remove_msg(pInfo, pClient);
868 if(pMsg)
869 {
870 kfree(pMsg);
871 TRACE_M("enable_signals - msg kfree %x",(int)pMsg);
872 }
873 }
874 kfree(pClient);
875 TRACE_M("enable_signals - kfree %x",(int)pClient);
876 return 0;
877 }
878 }
879 return -EINVAL;
880 }
881 else
882 {
883 pClient=findClient(pInfo, pid);
884 if(pClient)
885 {
886 /* update signal options */
887 pClient->sig_flags=arg;
888 }
889 else
890 {
891 /* add client to client list */
892 pClient=kmalloc(sizeof(struct r3964_client_info), GFP_KERNEL);
893 TRACE_M("enable_signals - kmalloc %x",(int)pClient);
894 if(pClient==NULL)
895 return -ENOMEM;
896
897 TRACE_PS("add client %d to client list", pid);
898 spin_lock_init(&pClient->lock);
899 pClient->sig_flags=arg;
900 pClient->pid = pid;
901 pClient->next=pInfo->firstClient;
902 pClient->first_msg = NULL;
903 pClient->last_msg = NULL;
904 pClient->next_block_to_read = NULL;
905 pClient->msg_count = 0;
906 pInfo->firstClient=pClient;
907 }
908 }
909
910 return 0;
911 }
912
913 static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char __user *buf)
914 {
915 struct r3964_client_info *pClient;
916 struct r3964_block_header *block;
917
918 if(!buf)
919 {
920 return -EINVAL;
921 }
922
923 pClient=findClient(pInfo,pid);
924 if(pClient==NULL)
925 {
926 return -EINVAL;
927 }
928
929 block=pClient->next_block_to_read;
930 if(!block)
931 {
932 return 0;
933 }
934 else
935 {
936 if (copy_to_user (buf, block->data, block->length))
937 return -EFAULT;
938
939 remove_client_block(pInfo, pClient);
940 return block->length;
941 }
942
943 return -EINVAL;
944 }
945
946 static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
947 int error_code, struct r3964_block_header *pBlock)
948 {
949 struct r3964_message *pMsg;
950 unsigned long flags;
951
952 if(pClient->msg_count<R3964_MAX_MSG_COUNT-1)
953 {
954 queue_the_message:
955
956 pMsg = kmalloc(sizeof(struct r3964_message), GFP_KERNEL);
957 TRACE_M("add_msg - kmalloc %x",(int)pMsg);
958 if(pMsg==NULL) {
959 return;
960 }
961
962 spin_lock_irqsave(&pClient->lock, flags);
963
964 pMsg->msg_id = msg_id;
965 pMsg->arg = arg;
966 pMsg->error_code = error_code;
967 pMsg->block = pBlock;
968 pMsg->next = NULL;
969
970 if(pClient->last_msg==NULL)
971 {
972 pClient->first_msg=pClient->last_msg=pMsg;
973 }
974 else
975 {
976 pClient->last_msg->next = pMsg;
977 pClient->last_msg=pMsg;
978 }
979
980 pClient->msg_count++;
981
982 if(pBlock!=NULL)
983 {
984 pBlock->locks++;
985 }
986 spin_unlock_irqrestore(&pClient->lock, flags);
987 }
988 else
989 {
990 if((pClient->last_msg->msg_id == R3964_MSG_ACK)
991 && (pClient->last_msg->error_code==R3964_OVERFLOW))
992 {
993 pClient->last_msg->arg++;
994 TRACE_PE("add_msg - inc prev OVERFLOW-msg");
995 }
996 else
997 {
998 msg_id = R3964_MSG_ACK;
999 arg = 0;
1000 error_code = R3964_OVERFLOW;
1001 pBlock = NULL;
1002 TRACE_PE("add_msg - queue OVERFLOW-msg");
1003 goto queue_the_message;
1004 }
1005 }
1006 /* Send SIGIO signal to client process: */
1007 if(pClient->sig_flags & R3964_USE_SIGIO)
1008 {
1009 kill_proc(pClient->pid, SIGIO, 1);
1010 }
1011 }
1012
1013 static struct r3964_message *remove_msg(struct r3964_info *pInfo,
1014 struct r3964_client_info *pClient)
1015 {
1016 struct r3964_message *pMsg=NULL;
1017 unsigned long flags;
1018
1019 if(pClient->first_msg)
1020 {
1021 spin_lock_irqsave(&pClient->lock, flags);
1022
1023 pMsg = pClient->first_msg;
1024 pClient->first_msg = pMsg->next;
1025 if(pClient->first_msg==NULL)
1026 {
1027 pClient->last_msg = NULL;
1028 }
1029
1030 pClient->msg_count--;
1031 if(pMsg->block)
1032 {
1033 remove_client_block(pInfo, pClient);
1034 pClient->next_block_to_read = pMsg->block;
1035 }
1036 spin_unlock_irqrestore(&pClient->lock, flags);
1037 }
1038 return pMsg;
1039 }
1040
1041 static void remove_client_block(struct r3964_info *pInfo,
1042 struct r3964_client_info *pClient)
1043 {
1044 struct r3964_block_header *block;
1045
1046 TRACE_PS("remove_client_block PID %d", pClient->pid);
1047
1048 block=pClient->next_block_to_read;
1049 if(block)
1050 {
1051 block->locks--;
1052 if(block->locks==0)
1053 {
1054 remove_from_rx_queue(pInfo, block);
1055 }
1056 }
1057 pClient->next_block_to_read = NULL;
1058 }
1059
1060
1061 /*************************************************************
1062 * Line discipline routines
1063 *************************************************************/
1064
1065 static int r3964_open(struct tty_struct *tty)
1066 {
1067 struct r3964_info *pInfo;
1068
1069 TRACE_L("open");
1070 TRACE_L("tty=%x, PID=%d, disc_data=%x",
1071 (int)tty, current->pid, (int)tty->disc_data);
1072
1073 pInfo=kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
1074 TRACE_M("r3964_open - info kmalloc %x",(int)pInfo);
1075
1076 if(!pInfo)
1077 {
1078 printk(KERN_ERR "r3964: failed to alloc info structure\n");
1079 return -ENOMEM;
1080 }
1081
1082 pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
1083 TRACE_M("r3964_open - rx_buf kmalloc %x",(int)pInfo->rx_buf);
1084
1085 if(!pInfo->rx_buf)
1086 {
1087 printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
1088 kfree(pInfo);
1089 TRACE_M("r3964_open - info kfree %x",(int)pInfo);
1090 return -ENOMEM;
1091 }
1092
1093 pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
1094 TRACE_M("r3964_open - tx_buf kmalloc %x",(int)pInfo->tx_buf);
1095
1096 if(!pInfo->tx_buf)
1097 {
1098 printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
1099 kfree(pInfo->rx_buf);
1100 TRACE_M("r3964_open - rx_buf kfree %x",(int)pInfo->rx_buf);
1101 kfree(pInfo);
1102 TRACE_M("r3964_open - info kfree %x",(int)pInfo);
1103 return -ENOMEM;
1104 }
1105
1106 spin_lock_init(&pInfo->lock);
1107 pInfo->tty = tty;
1108 init_waitqueue_head (&pInfo->read_wait);
1109 pInfo->priority = R3964_MASTER;
1110 pInfo->rx_first = pInfo->rx_last = NULL;
1111 pInfo->tx_first = pInfo->tx_last = NULL;
1112 pInfo->rx_position = 0;
1113 pInfo->tx_position = 0;
1114 pInfo->last_rx = 0;
1115 pInfo->blocks_in_rx_queue = 0;
1116 pInfo->firstClient=NULL;
1117 pInfo->state=R3964_IDLE;
1118 pInfo->flags = R3964_DEBUG;
1119 pInfo->nRetry = 0;
1120
1121 tty->disc_data = pInfo;
1122
1123 init_timer(&pInfo->tmr);
1124 pInfo->tmr.data = (unsigned long)pInfo;
1125 pInfo->tmr.function = on_timeout;
1126
1127 return 0;
1128 }
1129
1130 static void r3964_close(struct tty_struct *tty)
1131 {
1132 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1133 struct r3964_client_info *pClient, *pNext;
1134 struct r3964_message *pMsg;
1135 struct r3964_block_header *pHeader, *pNextHeader;
1136 unsigned long flags;
1137
1138 TRACE_L("close");
1139
1140 /*
1141 * Make sure that our task queue isn't activated. If it
1142 * is, take it out of the linked list.
1143 */
1144 del_timer_sync(&pInfo->tmr);
1145
1146 /* Remove client-structs and message queues: */
1147 pClient=pInfo->firstClient;
1148 while(pClient)
1149 {
1150 pNext=pClient->next;
1151 while(pClient->msg_count)
1152 {
1153 pMsg=remove_msg(pInfo, pClient);
1154 if(pMsg)
1155 {
1156 kfree(pMsg);
1157 TRACE_M("r3964_close - msg kfree %x",(int)pMsg);
1158 }
1159 }
1160 kfree(pClient);
1161 TRACE_M("r3964_close - client kfree %x",(int)pClient);
1162 pClient=pNext;
1163 }
1164 /* Remove jobs from tx_queue: */
1165 spin_lock_irqsave(&pInfo->lock, flags);
1166 pHeader=pInfo->tx_first;
1167 pInfo->tx_first=pInfo->tx_last=NULL;
1168 spin_unlock_irqrestore(&pInfo->lock, flags);
1169
1170 while(pHeader)
1171 {
1172 pNextHeader=pHeader->next;
1173 kfree(pHeader);
1174 pHeader=pNextHeader;
1175 }
1176
1177 /* Free buffers: */
1178 wake_up_interruptible(&pInfo->read_wait);
1179 kfree(pInfo->rx_buf);
1180 TRACE_M("r3964_close - rx_buf kfree %x",(int)pInfo->rx_buf);
1181 kfree(pInfo->tx_buf);
1182 TRACE_M("r3964_close - tx_buf kfree %x",(int)pInfo->tx_buf);
1183 kfree(pInfo);
1184 TRACE_M("r3964_close - info kfree %x",(int)pInfo);
1185 }
1186
1187 static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
1188 unsigned char __user *buf, size_t nr)
1189 {
1190 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1191 struct r3964_client_info *pClient;
1192 struct r3964_message *pMsg;
1193 struct r3964_client_message theMsg;
1194 DECLARE_WAITQUEUE (wait, current);
1195
1196 int pid = current->pid;
1197 int count;
1198
1199 TRACE_L("read()");
1200
1201 pClient=findClient(pInfo, pid);
1202 if(pClient)
1203 {
1204 pMsg = remove_msg(pInfo, pClient);
1205 if(pMsg==NULL)
1206 {
1207 /* no messages available. */
1208 if (file->f_flags & O_NONBLOCK)
1209 {
1210 return -EAGAIN;
1211 }
1212 /* block until there is a message: */
1213 add_wait_queue(&pInfo->read_wait, &wait);
1214 repeat:
1215 current->state = TASK_INTERRUPTIBLE;
1216 pMsg = remove_msg(pInfo, pClient);
1217 if (!pMsg && !signal_pending(current))
1218 {
1219 schedule();
1220 goto repeat;
1221 }
1222 current->state = TASK_RUNNING;
1223 remove_wait_queue(&pInfo->read_wait, &wait);
1224 }
1225
1226 /* If we still haven't got a message, we must have been signalled */
1227
1228 if (!pMsg) return -EINTR;
1229
1230 /* deliver msg to client process: */
1231 theMsg.msg_id = pMsg->msg_id;
1232 theMsg.arg = pMsg->arg;
1233 theMsg.error_code = pMsg->error_code;
1234 count = sizeof(struct r3964_client_message);
1235
1236 kfree(pMsg);
1237 TRACE_M("r3964_read - msg kfree %x",(int)pMsg);
1238
1239 if (copy_to_user(buf,&theMsg, count))
1240 return -EFAULT;
1241
1242 TRACE_PS("read - return %d", count);
1243 return count;
1244 }
1245 return -EPERM;
1246 }
1247
1248 static ssize_t r3964_write(struct tty_struct * tty, struct file * file,
1249 const unsigned char *data, size_t count)
1250 {
1251 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1252 struct r3964_block_header *pHeader;
1253 struct r3964_client_info *pClient;
1254 unsigned char *new_data;
1255 int pid;
1256
1257 TRACE_L("write request, %d characters", count);
1258 /*
1259 * Verify the pointers
1260 */
1261
1262 if(!pInfo)
1263 return -EIO;
1264
1265 /*
1266 * Ensure that the caller does not wish to send too much.
1267 */
1268 if (count > R3964_MTU)
1269 {
1270 if (pInfo->flags & R3964_DEBUG)
1271 {
1272 TRACE_L (KERN_WARNING
1273 "r3964_write: truncating user packet "
1274 "from %u to mtu %d", count, R3964_MTU);
1275 }
1276 count = R3964_MTU;
1277 }
1278 /*
1279 * Allocate a buffer for the data and copy it from the buffer with header prepended
1280 */
1281 new_data = kmalloc (count+sizeof(struct r3964_block_header), GFP_KERNEL);
1282 TRACE_M("r3964_write - kmalloc %x",(int)new_data);
1283 if (new_data == NULL) {
1284 if (pInfo->flags & R3964_DEBUG)
1285 {
1286 printk (KERN_ERR
1287 "r3964_write: no memory\n");
1288 }
1289 return -ENOSPC;
1290 }
1291
1292 pHeader = (struct r3964_block_header *)new_data;
1293 pHeader->data = new_data + sizeof(struct r3964_block_header);
1294 pHeader->length = count;
1295 pHeader->locks = 0;
1296 pHeader->owner = NULL;
1297
1298 pid=current->pid;
1299
1300 pClient=findClient(pInfo, pid);
1301 if(pClient)
1302 {
1303 pHeader->owner = pClient;
1304 }
1305
1306 memcpy(pHeader->data, data, count); /* We already verified this */
1307
1308 if(pInfo->flags & R3964_DEBUG)
1309 {
1310 dump_block(pHeader->data, count);
1311 }
1312
1313 /*
1314 * Add buffer to transmit-queue:
1315 */
1316 add_tx_queue(pInfo, pHeader);
1317 trigger_transmit(pInfo);
1318
1319 return 0;
1320 }
1321
1322 static int r3964_ioctl(struct tty_struct * tty, struct file * file,
1323 unsigned int cmd, unsigned long arg)
1324 {
1325 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1326 if(pInfo==NULL)
1327 return -EINVAL;
1328 switch(cmd)
1329 {
1330 case R3964_ENABLE_SIGNALS:
1331 return enable_signals(pInfo, current->pid, arg);
1332 case R3964_SETPRIORITY:
1333 if(arg<R3964_MASTER || arg>R3964_SLAVE)
1334 return -EINVAL;
1335 pInfo->priority = arg & 0xff;
1336 return 0;
1337 case R3964_USE_BCC:
1338 if(arg)
1339 pInfo->flags |= R3964_BCC;
1340 else
1341 pInfo->flags &= ~R3964_BCC;
1342 return 0;
1343 case R3964_READ_TELEGRAM:
1344 return read_telegram(pInfo, current->pid, (unsigned char __user *)arg);
1345 default:
1346 return -ENOIOCTLCMD;
1347 }
1348 }
1349
1350 static void r3964_set_termios(struct tty_struct *tty, struct termios * old)
1351 {
1352 TRACE_L("set_termios");
1353 }
1354
1355 /* Called without the kernel lock held - fine */
1356 static unsigned int r3964_poll(struct tty_struct * tty, struct file * file,
1357 struct poll_table_struct *wait)
1358 {
1359 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1360 int pid=current->pid;
1361 struct r3964_client_info *pClient;
1362 struct r3964_message *pMsg=NULL;
1363 unsigned long flags;
1364 int result = POLLOUT;
1365
1366 TRACE_L("POLL");
1367
1368 pClient=findClient(pInfo,pid);
1369 if(pClient)
1370 {
1371 poll_wait(file, &pInfo->read_wait, wait);
1372 spin_lock_irqsave(&pInfo->lock, flags);
1373 pMsg=pClient->first_msg;
1374 spin_unlock_irqrestore(&pInfo->lock, flags);
1375 if(pMsg)
1376 result |= POLLIN | POLLRDNORM;
1377 }
1378 else
1379 {
1380 result = -EINVAL;
1381 }
1382 return result;
1383 }
1384
1385 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
1386 char *fp, int count)
1387 {
1388 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1389 const unsigned char *p;
1390 char *f, flags = 0;
1391 int i;
1392
1393 for (i=count, p = cp, f = fp; i; i--, p++) {
1394 if (f)
1395 flags = *f++;
1396 if(flags==TTY_NORMAL)
1397 {
1398 receive_char(pInfo, *p);
1399 }
1400 else
1401 {
1402 receive_error(pInfo, flags);
1403 }
1404
1405 }
1406 }
1407
1408 static int r3964_receive_room(struct tty_struct *tty)
1409 {
1410 TRACE_L("receive_room");
1411 return -1;
1412 }
1413
1414
1415 MODULE_LICENSE("GPL");
1416 MODULE_ALIAS_LDISC(N_R3964);
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