xref: /linux/drivers/s390/net/ctcm_main.c (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright IBM Corp. 2001, 2009
4  * Author(s):
5  *	Original CTC driver(s):
6  *		Fritz Elfert (felfert@millenux.com)
7  *		Dieter Wellerdiek (wel@de.ibm.com)
8  *		Martin Schwidefsky (schwidefsky@de.ibm.com)
9  *		Denis Joseph Barrow (barrow_dj@yahoo.com)
10  *		Jochen Roehrig (roehrig@de.ibm.com)
11  *		Cornelia Huck <cornelia.huck@de.ibm.com>
12  *	MPC additions:
13  *		Belinda Thompson (belindat@us.ibm.com)
14  *		Andy Richter (richtera@us.ibm.com)
15  *	Revived by:
16  *		Peter Tiedemann (ptiedem@de.ibm.com)
17  */
18 
19 #undef DEBUG
20 #undef DEBUGDATA
21 #undef DEBUGCCW
22 
23 #define KMSG_COMPONENT "ctcm"
24 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
25 
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/errno.h>
31 #include <linux/types.h>
32 #include <linux/interrupt.h>
33 #include <linux/timer.h>
34 #include <linux/bitops.h>
35 
36 #include <linux/signal.h>
37 #include <linux/string.h>
38 
39 #include <linux/ip.h>
40 #include <linux/if_arp.h>
41 #include <linux/tcp.h>
42 #include <linux/skbuff.h>
43 #include <linux/ctype.h>
44 #include <net/dst.h>
45 
46 #include <linux/io.h>
47 #include <asm/ccwdev.h>
48 #include <asm/ccwgroup.h>
49 #include <linux/uaccess.h>
50 
51 #include <asm/idals.h>
52 
53 #include "ctcm_fsms.h"
54 #include "ctcm_main.h"
55 
56 /* Some common global variables */
57 
58 /*
59  * The root device for ctcm group devices
60  */
61 static struct device *ctcm_root_dev;
62 
63 /*
64  * Linked list of all detected channels.
65  */
66 struct channel *channels;
67 
68 /*
69  * Unpack a just received skb and hand it over to
70  * upper layers.
71  *
72  *  ch		The channel where this skb has been received.
73  *  pskb	The received skb.
74  */
75 void ctcm_unpack_skb(struct channel *ch, struct sk_buff *pskb)
76 {
77 	struct net_device *dev = ch->netdev;
78 	struct ctcm_priv *priv = dev->ml_priv;
79 	__u16 len = *((__u16 *) pskb->data);
80 
81 	skb_put(pskb, 2 + LL_HEADER_LENGTH);
82 	skb_pull(pskb, 2);
83 	pskb->dev = dev;
84 	pskb->ip_summed = CHECKSUM_UNNECESSARY;
85 	while (len > 0) {
86 		struct sk_buff *skb;
87 		int skblen;
88 		struct ll_header *header = (struct ll_header *)pskb->data;
89 
90 		skb_pull(pskb, LL_HEADER_LENGTH);
91 		if ((ch->protocol == CTCM_PROTO_S390) &&
92 		    (header->type != ETH_P_IP)) {
93 			if (!(ch->logflags & LOG_FLAG_ILLEGALPKT)) {
94 				ch->logflags |= LOG_FLAG_ILLEGALPKT;
95 				/*
96 				 * Check packet type only if we stick strictly
97 				 * to S/390's protocol of OS390. This only
98 				 * supports IP. Otherwise allow any packet
99 				 * type.
100 				 */
101 				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
102 					"%s(%s): Illegal packet type 0x%04x"
103 					" - dropping",
104 					CTCM_FUNTAIL, dev->name, header->type);
105 			}
106 			priv->stats.rx_dropped++;
107 			priv->stats.rx_frame_errors++;
108 			return;
109 		}
110 		pskb->protocol = cpu_to_be16(header->type);
111 		if ((header->length <= LL_HEADER_LENGTH) ||
112 		    (len <= LL_HEADER_LENGTH)) {
113 			if (!(ch->logflags & LOG_FLAG_ILLEGALSIZE)) {
114 				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
115 					"%s(%s): Illegal packet size %d(%d,%d)"
116 					"- dropping",
117 					CTCM_FUNTAIL, dev->name,
118 					header->length, dev->mtu, len);
119 				ch->logflags |= LOG_FLAG_ILLEGALSIZE;
120 			}
121 
122 			priv->stats.rx_dropped++;
123 			priv->stats.rx_length_errors++;
124 			return;
125 		}
126 		header->length -= LL_HEADER_LENGTH;
127 		len -= LL_HEADER_LENGTH;
128 		if ((header->length > skb_tailroom(pskb)) ||
129 		    (header->length > len)) {
130 			if (!(ch->logflags & LOG_FLAG_OVERRUN)) {
131 				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
132 					"%s(%s): Packet size %d (overrun)"
133 					" - dropping", CTCM_FUNTAIL,
134 						dev->name, header->length);
135 				ch->logflags |= LOG_FLAG_OVERRUN;
136 			}
137 
138 			priv->stats.rx_dropped++;
139 			priv->stats.rx_length_errors++;
140 			return;
141 		}
142 		skb_put(pskb, header->length);
143 		skb_reset_mac_header(pskb);
144 		len -= header->length;
145 		skb = dev_alloc_skb(pskb->len);
146 		if (!skb) {
147 			if (!(ch->logflags & LOG_FLAG_NOMEM)) {
148 				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
149 					"%s(%s): MEMORY allocation error",
150 						CTCM_FUNTAIL, dev->name);
151 				ch->logflags |= LOG_FLAG_NOMEM;
152 			}
153 			priv->stats.rx_dropped++;
154 			return;
155 		}
156 		skb_copy_from_linear_data(pskb, skb_put(skb, pskb->len),
157 					  pskb->len);
158 		skb_reset_mac_header(skb);
159 		skb->dev = pskb->dev;
160 		skb->protocol = pskb->protocol;
161 		pskb->ip_summed = CHECKSUM_UNNECESSARY;
162 		skblen = skb->len;
163 		/*
164 		 * reset logflags
165 		 */
166 		ch->logflags = 0;
167 		priv->stats.rx_packets++;
168 		priv->stats.rx_bytes += skblen;
169 		netif_rx(skb);
170 		if (len > 0) {
171 			skb_pull(pskb, header->length);
172 			if (skb_tailroom(pskb) < LL_HEADER_LENGTH) {
173 				CTCM_DBF_DEV_NAME(TRACE, dev,
174 					"Overrun in ctcm_unpack_skb");
175 				ch->logflags |= LOG_FLAG_OVERRUN;
176 				return;
177 			}
178 			skb_put(pskb, LL_HEADER_LENGTH);
179 		}
180 	}
181 }
182 
183 /*
184  * Release a specific channel in the channel list.
185  *
186  *  ch		Pointer to channel struct to be released.
187  */
188 static void channel_free(struct channel *ch)
189 {
190 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO, "%s(%s)", CTCM_FUNTAIL, ch->id);
191 	ch->flags &= ~CHANNEL_FLAGS_INUSE;
192 	fsm_newstate(ch->fsm, CTC_STATE_IDLE);
193 }
194 
195 /*
196  * Remove a specific channel in the channel list.
197  *
198  *  ch		Pointer to channel struct to be released.
199  */
200 static void channel_remove(struct channel *ch)
201 {
202 	struct channel **c = &channels;
203 	char chid[CTCM_ID_SIZE];
204 	int ok = 0;
205 
206 	if (ch == NULL)
207 		return;
208 	else
209 		strscpy(chid, ch->id, sizeof(chid));
210 
211 	channel_free(ch);
212 	while (*c) {
213 		if (*c == ch) {
214 			*c = ch->next;
215 			fsm_deltimer(&ch->timer);
216 			if (IS_MPC(ch))
217 				fsm_deltimer(&ch->sweep_timer);
218 
219 			kfree_fsm(ch->fsm);
220 			clear_normalized_cda(&ch->ccw[4]);
221 			if (ch->trans_skb != NULL) {
222 				clear_normalized_cda(&ch->ccw[1]);
223 				dev_kfree_skb_any(ch->trans_skb);
224 			}
225 			if (IS_MPC(ch)) {
226 				tasklet_kill(&ch->ch_tasklet);
227 				tasklet_kill(&ch->ch_disc_tasklet);
228 				kfree(ch->discontact_th);
229 			}
230 			kfree(ch->ccw);
231 			kfree(ch->irb);
232 			kfree(ch);
233 			ok = 1;
234 			break;
235 		}
236 		c = &((*c)->next);
237 	}
238 
239 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO, "%s(%s) %s", CTCM_FUNTAIL,
240 			chid, ok ? "OK" : "failed");
241 }
242 
243 /*
244  * Get a specific channel from the channel list.
245  *
246  *  type	Type of channel we are interested in.
247  *  id		Id of channel we are interested in.
248  *  direction	Direction we want to use this channel for.
249  *
250  * returns Pointer to a channel or NULL if no matching channel available.
251  */
252 static struct channel *channel_get(enum ctcm_channel_types type,
253 					char *id, int direction)
254 {
255 	struct channel *ch = channels;
256 
257 	while (ch && (strncmp(ch->id, id, CTCM_ID_SIZE) || (ch->type != type)))
258 		ch = ch->next;
259 	if (!ch) {
260 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
261 				"%s(%d, %s, %d) not found in channel list\n",
262 				CTCM_FUNTAIL, type, id, direction);
263 	} else {
264 		if (ch->flags & CHANNEL_FLAGS_INUSE)
265 			ch = NULL;
266 		else {
267 			ch->flags |= CHANNEL_FLAGS_INUSE;
268 			ch->flags &= ~CHANNEL_FLAGS_RWMASK;
269 			ch->flags |= (direction == CTCM_WRITE)
270 			    ? CHANNEL_FLAGS_WRITE : CHANNEL_FLAGS_READ;
271 			fsm_newstate(ch->fsm, CTC_STATE_STOPPED);
272 		}
273 	}
274 	return ch;
275 }
276 
277 static long ctcm_check_irb_error(struct ccw_device *cdev, struct irb *irb)
278 {
279 	if (!IS_ERR(irb))
280 		return 0;
281 
282 	CTCM_DBF_TEXT_(ERROR, CTC_DBF_WARN,
283 			"irb error %ld on device %s\n",
284 				PTR_ERR(irb), dev_name(&cdev->dev));
285 
286 	switch (PTR_ERR(irb)) {
287 	case -EIO:
288 		dev_err(&cdev->dev,
289 			"An I/O-error occurred on the CTCM device\n");
290 		break;
291 	case -ETIMEDOUT:
292 		dev_err(&cdev->dev,
293 			"An adapter hardware operation timed out\n");
294 		break;
295 	default:
296 		dev_err(&cdev->dev,
297 			"An error occurred on the adapter hardware\n");
298 	}
299 	return PTR_ERR(irb);
300 }
301 
302 
303 /*
304  * Check sense of a unit check.
305  *
306  *  ch		The channel, the sense code belongs to.
307  *  sense	The sense code to inspect.
308  */
309 static void ccw_unit_check(struct channel *ch, __u8 sense)
310 {
311 	CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
312 			"%s(%s): %02x",
313 				CTCM_FUNTAIL, ch->id, sense);
314 
315 	if (sense & SNS0_INTERVENTION_REQ) {
316 		if (sense & 0x01) {
317 			if (ch->sense_rc != 0x01) {
318 				pr_notice(
319 					"%s: The communication peer has "
320 					"disconnected\n", ch->id);
321 				ch->sense_rc = 0x01;
322 			}
323 			fsm_event(ch->fsm, CTC_EVENT_UC_RCRESET, ch);
324 		} else {
325 			if (ch->sense_rc != SNS0_INTERVENTION_REQ) {
326 				pr_notice(
327 					"%s: The remote operating system is "
328 					"not available\n", ch->id);
329 				ch->sense_rc = SNS0_INTERVENTION_REQ;
330 			}
331 			fsm_event(ch->fsm, CTC_EVENT_UC_RSRESET, ch);
332 		}
333 	} else if (sense & SNS0_EQUIPMENT_CHECK) {
334 		if (sense & SNS0_BUS_OUT_CHECK) {
335 			if (ch->sense_rc != SNS0_BUS_OUT_CHECK) {
336 				CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
337 					"%s(%s): remote HW error %02x",
338 						CTCM_FUNTAIL, ch->id, sense);
339 				ch->sense_rc = SNS0_BUS_OUT_CHECK;
340 			}
341 			fsm_event(ch->fsm, CTC_EVENT_UC_HWFAIL, ch);
342 		} else {
343 			if (ch->sense_rc != SNS0_EQUIPMENT_CHECK) {
344 				CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
345 					"%s(%s): remote read parity error %02x",
346 						CTCM_FUNTAIL, ch->id, sense);
347 				ch->sense_rc = SNS0_EQUIPMENT_CHECK;
348 			}
349 			fsm_event(ch->fsm, CTC_EVENT_UC_RXPARITY, ch);
350 		}
351 	} else if (sense & SNS0_BUS_OUT_CHECK) {
352 		if (ch->sense_rc != SNS0_BUS_OUT_CHECK) {
353 			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
354 				"%s(%s): BUS OUT error %02x",
355 					CTCM_FUNTAIL, ch->id, sense);
356 			ch->sense_rc = SNS0_BUS_OUT_CHECK;
357 		}
358 		if (sense & 0x04)	/* data-streaming timeout */
359 			fsm_event(ch->fsm, CTC_EVENT_UC_TXTIMEOUT, ch);
360 		else			/* Data-transfer parity error */
361 			fsm_event(ch->fsm, CTC_EVENT_UC_TXPARITY, ch);
362 	} else if (sense & SNS0_CMD_REJECT) {
363 		if (ch->sense_rc != SNS0_CMD_REJECT) {
364 			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
365 				"%s(%s): Command rejected",
366 						CTCM_FUNTAIL, ch->id);
367 			ch->sense_rc = SNS0_CMD_REJECT;
368 		}
369 	} else if (sense == 0) {
370 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
371 			"%s(%s): Unit check ZERO",
372 					CTCM_FUNTAIL, ch->id);
373 		fsm_event(ch->fsm, CTC_EVENT_UC_ZERO, ch);
374 	} else {
375 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
376 			"%s(%s): Unit check code %02x unknown",
377 					CTCM_FUNTAIL, ch->id, sense);
378 		fsm_event(ch->fsm, CTC_EVENT_UC_UNKNOWN, ch);
379 	}
380 }
381 
382 int ctcm_ch_alloc_buffer(struct channel *ch)
383 {
384 	clear_normalized_cda(&ch->ccw[1]);
385 	ch->trans_skb = __dev_alloc_skb(ch->max_bufsize, GFP_ATOMIC | GFP_DMA);
386 	if (ch->trans_skb == NULL) {
387 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
388 			"%s(%s): %s trans_skb allocation error",
389 			CTCM_FUNTAIL, ch->id,
390 			(CHANNEL_DIRECTION(ch->flags) == CTCM_READ) ?
391 				"RX" : "TX");
392 		return -ENOMEM;
393 	}
394 
395 	ch->ccw[1].count = ch->max_bufsize;
396 	if (set_normalized_cda(&ch->ccw[1], ch->trans_skb->data)) {
397 		dev_kfree_skb(ch->trans_skb);
398 		ch->trans_skb = NULL;
399 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
400 			"%s(%s): %s set norm_cda failed",
401 			CTCM_FUNTAIL, ch->id,
402 			(CHANNEL_DIRECTION(ch->flags) == CTCM_READ) ?
403 				"RX" : "TX");
404 		return -ENOMEM;
405 	}
406 
407 	ch->ccw[1].count = 0;
408 	ch->trans_skb_data = ch->trans_skb->data;
409 	ch->flags &= ~CHANNEL_FLAGS_BUFSIZE_CHANGED;
410 	return 0;
411 }
412 
413 /*
414  * Interface API for upper network layers
415  */
416 
417 /*
418  * Open an interface.
419  * Called from generic network layer when ifconfig up is run.
420  *
421  *  dev		Pointer to interface struct.
422  *
423  * returns 0 on success, -ERRNO on failure. (Never fails.)
424  */
425 int ctcm_open(struct net_device *dev)
426 {
427 	struct ctcm_priv *priv = dev->ml_priv;
428 
429 	CTCMY_DBF_DEV_NAME(SETUP, dev, "");
430 	if (!IS_MPC(priv))
431 		fsm_event(priv->fsm,	DEV_EVENT_START, dev);
432 	return 0;
433 }
434 
435 /*
436  * Close an interface.
437  * Called from generic network layer when ifconfig down is run.
438  *
439  *  dev		Pointer to interface struct.
440  *
441  * returns 0 on success, -ERRNO on failure. (Never fails.)
442  */
443 int ctcm_close(struct net_device *dev)
444 {
445 	struct ctcm_priv *priv = dev->ml_priv;
446 
447 	CTCMY_DBF_DEV_NAME(SETUP, dev, "");
448 	if (!IS_MPC(priv))
449 		fsm_event(priv->fsm, DEV_EVENT_STOP, dev);
450 	return 0;
451 }
452 
453 
454 /*
455  * Transmit a packet.
456  * This is a helper function for ctcm_tx().
457  *
458  *  ch		Channel to be used for sending.
459  *  skb		Pointer to struct sk_buff of packet to send.
460  *            The linklevel header has already been set up
461  *            by ctcm_tx().
462  *
463  * returns 0 on success, -ERRNO on failure. (Never fails.)
464  */
465 static int ctcm_transmit_skb(struct channel *ch, struct sk_buff *skb)
466 {
467 	unsigned long saveflags;
468 	struct ll_header header;
469 	int rc = 0;
470 	__u16 block_len;
471 	int ccw_idx;
472 	struct sk_buff *nskb;
473 	unsigned long hi;
474 
475 	/* we need to acquire the lock for testing the state
476 	 * otherwise we can have an IRQ changing the state to
477 	 * TXIDLE after the test but before acquiring the lock.
478 	 */
479 	spin_lock_irqsave(&ch->collect_lock, saveflags);
480 	if (fsm_getstate(ch->fsm) != CTC_STATE_TXIDLE) {
481 		int l = skb->len + LL_HEADER_LENGTH;
482 
483 		if (ch->collect_len + l > ch->max_bufsize - 2) {
484 			spin_unlock_irqrestore(&ch->collect_lock, saveflags);
485 			return -EBUSY;
486 		} else {
487 			refcount_inc(&skb->users);
488 			header.length = l;
489 			header.type = be16_to_cpu(skb->protocol);
490 			header.unused = 0;
491 			memcpy(skb_push(skb, LL_HEADER_LENGTH), &header,
492 			       LL_HEADER_LENGTH);
493 			skb_queue_tail(&ch->collect_queue, skb);
494 			ch->collect_len += l;
495 		}
496 		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
497 		goto done;
498 	}
499 	spin_unlock_irqrestore(&ch->collect_lock, saveflags);
500 	/*
501 	 * Protect skb against beeing free'd by upper
502 	 * layers.
503 	 */
504 	refcount_inc(&skb->users);
505 	ch->prof.txlen += skb->len;
506 	header.length = skb->len + LL_HEADER_LENGTH;
507 	header.type = be16_to_cpu(skb->protocol);
508 	header.unused = 0;
509 	memcpy(skb_push(skb, LL_HEADER_LENGTH), &header, LL_HEADER_LENGTH);
510 	block_len = skb->len + 2;
511 	*((__u16 *)skb_push(skb, 2)) = block_len;
512 
513 	/*
514 	 * IDAL support in CTCM is broken, so we have to
515 	 * care about skb's above 2G ourselves.
516 	 */
517 	hi = ((unsigned long)skb_tail_pointer(skb) + LL_HEADER_LENGTH) >> 31;
518 	if (hi) {
519 		nskb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
520 		if (!nskb) {
521 			refcount_dec(&skb->users);
522 			skb_pull(skb, LL_HEADER_LENGTH + 2);
523 			ctcm_clear_busy(ch->netdev);
524 			return -ENOMEM;
525 		} else {
526 			skb_put_data(nskb, skb->data, skb->len);
527 			refcount_inc(&nskb->users);
528 			refcount_dec(&skb->users);
529 			dev_kfree_skb_irq(skb);
530 			skb = nskb;
531 		}
532 	}
533 
534 	ch->ccw[4].count = block_len;
535 	if (set_normalized_cda(&ch->ccw[4], skb->data)) {
536 		/*
537 		 * idal allocation failed, try via copying to
538 		 * trans_skb. trans_skb usually has a pre-allocated
539 		 * idal.
540 		 */
541 		if (ctcm_checkalloc_buffer(ch)) {
542 			/*
543 			 * Remove our header. It gets added
544 			 * again on retransmit.
545 			 */
546 			refcount_dec(&skb->users);
547 			skb_pull(skb, LL_HEADER_LENGTH + 2);
548 			ctcm_clear_busy(ch->netdev);
549 			return -ENOMEM;
550 		}
551 
552 		skb_reset_tail_pointer(ch->trans_skb);
553 		ch->trans_skb->len = 0;
554 		ch->ccw[1].count = skb->len;
555 		skb_copy_from_linear_data(skb,
556 				skb_put(ch->trans_skb, skb->len), skb->len);
557 		refcount_dec(&skb->users);
558 		dev_kfree_skb_irq(skb);
559 		ccw_idx = 0;
560 	} else {
561 		skb_queue_tail(&ch->io_queue, skb);
562 		ccw_idx = 3;
563 	}
564 	if (do_debug_ccw)
565 		ctcmpc_dumpit((char *)&ch->ccw[ccw_idx],
566 					sizeof(struct ccw1) * 3);
567 	ch->retry = 0;
568 	fsm_newstate(ch->fsm, CTC_STATE_TX);
569 	fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
570 	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
571 	ch->prof.send_stamp = jiffies;
572 	rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx], 0, 0xff, 0);
573 	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
574 	if (ccw_idx == 3)
575 		ch->prof.doios_single++;
576 	if (rc != 0) {
577 		fsm_deltimer(&ch->timer);
578 		ctcm_ccw_check_rc(ch, rc, "single skb TX");
579 		if (ccw_idx == 3)
580 			skb_dequeue_tail(&ch->io_queue);
581 		/*
582 		 * Remove our header. It gets added
583 		 * again on retransmit.
584 		 */
585 		skb_pull(skb, LL_HEADER_LENGTH + 2);
586 	} else if (ccw_idx == 0) {
587 		struct net_device *dev = ch->netdev;
588 		struct ctcm_priv *priv = dev->ml_priv;
589 		priv->stats.tx_packets++;
590 		priv->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
591 	}
592 done:
593 	ctcm_clear_busy(ch->netdev);
594 	return rc;
595 }
596 
597 static void ctcmpc_send_sweep_req(struct channel *rch)
598 {
599 	struct net_device *dev = rch->netdev;
600 	struct ctcm_priv *priv;
601 	struct mpc_group *grp;
602 	struct th_sweep *header;
603 	struct sk_buff *sweep_skb;
604 	struct channel *ch;
605 	/* int rc = 0; */
606 
607 	priv = dev->ml_priv;
608 	grp = priv->mpcg;
609 	ch = priv->channel[CTCM_WRITE];
610 
611 	/* sweep processing is not complete until response and request */
612 	/* has completed for all read channels in group		       */
613 	if (grp->in_sweep == 0) {
614 		grp->in_sweep = 1;
615 		grp->sweep_rsp_pend_num = grp->active_channels[CTCM_READ];
616 		grp->sweep_req_pend_num = grp->active_channels[CTCM_READ];
617 	}
618 
619 	sweep_skb = __dev_alloc_skb(MPC_BUFSIZE_DEFAULT, GFP_ATOMIC|GFP_DMA);
620 
621 	if (sweep_skb == NULL)	{
622 		/* rc = -ENOMEM; */
623 				goto nomem;
624 	}
625 
626 	header = skb_put_zero(sweep_skb, TH_SWEEP_LENGTH);
627 	header->th.th_ch_flag	= TH_SWEEP_REQ;  /* 0x0f */
628 	header->sw.th_last_seq	= ch->th_seq_num;
629 
630 	netif_trans_update(dev);
631 	skb_queue_tail(&ch->sweep_queue, sweep_skb);
632 
633 	fsm_addtimer(&ch->sweep_timer, 100, CTC_EVENT_RSWEEP_TIMER, ch);
634 
635 	return;
636 
637 nomem:
638 	grp->in_sweep = 0;
639 	ctcm_clear_busy(dev);
640 	fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
641 
642 	return;
643 }
644 
645 /*
646  * MPC mode version of transmit_skb
647  */
648 static int ctcmpc_transmit_skb(struct channel *ch, struct sk_buff *skb)
649 {
650 	struct pdu *p_header;
651 	struct net_device *dev = ch->netdev;
652 	struct ctcm_priv *priv = dev->ml_priv;
653 	struct mpc_group *grp = priv->mpcg;
654 	struct th_header *header;
655 	struct sk_buff *nskb;
656 	int rc = 0;
657 	int ccw_idx;
658 	unsigned long hi;
659 	unsigned long saveflags = 0;	/* avoids compiler warning */
660 
661 	CTCM_PR_DEBUG("Enter %s: %s, cp=%i ch=0x%p id=%s state=%s\n",
662 			__func__, dev->name, smp_processor_id(), ch,
663 					ch->id, fsm_getstate_str(ch->fsm));
664 
665 	if ((fsm_getstate(ch->fsm) != CTC_STATE_TXIDLE) || grp->in_sweep) {
666 		spin_lock_irqsave(&ch->collect_lock, saveflags);
667 		refcount_inc(&skb->users);
668 
669 		p_header = skb_push(skb, PDU_HEADER_LENGTH);
670 		p_header->pdu_offset = skb->len - PDU_HEADER_LENGTH;
671 		p_header->pdu_proto = 0x01;
672 		if (be16_to_cpu(skb->protocol) == ETH_P_SNAP) {
673 			p_header->pdu_flag = PDU_FIRST | PDU_CNTL;
674 		} else {
675 			p_header->pdu_flag = PDU_FIRST;
676 		}
677 		p_header->pdu_seq = 0;
678 
679 		CTCM_PR_DEBUG("%s(%s): Put on collect_q - skb len: %04x \n"
680 				"pdu header and data for up to 32 bytes:\n",
681 				__func__, dev->name, skb->len);
682 		CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
683 
684 		skb_queue_tail(&ch->collect_queue, skb);
685 		ch->collect_len += skb->len;
686 
687 		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
688 		goto done;
689 	}
690 
691 	/*
692 	 * Protect skb against beeing free'd by upper
693 	 * layers.
694 	 */
695 	refcount_inc(&skb->users);
696 
697 	/*
698 	 * IDAL support in CTCM is broken, so we have to
699 	 * care about skb's above 2G ourselves.
700 	 */
701 	hi = ((unsigned long)skb->tail + TH_HEADER_LENGTH) >> 31;
702 	if (hi) {
703 		nskb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
704 		if (!nskb) {
705 			goto nomem_exit;
706 		} else {
707 			skb_put_data(nskb, skb->data, skb->len);
708 			refcount_inc(&nskb->users);
709 			refcount_dec(&skb->users);
710 			dev_kfree_skb_irq(skb);
711 			skb = nskb;
712 		}
713 	}
714 
715 	p_header = skb_push(skb, PDU_HEADER_LENGTH);
716 	p_header->pdu_offset = skb->len - PDU_HEADER_LENGTH;
717 	p_header->pdu_proto = 0x01;
718 	p_header->pdu_seq = 0;
719 	if (be16_to_cpu(skb->protocol) == ETH_P_SNAP) {
720 		p_header->pdu_flag = PDU_FIRST | PDU_CNTL;
721 	} else {
722 		p_header->pdu_flag = PDU_FIRST;
723 	}
724 
725 	if (ch->collect_len > 0) {
726 		spin_lock_irqsave(&ch->collect_lock, saveflags);
727 		skb_queue_tail(&ch->collect_queue, skb);
728 		ch->collect_len += skb->len;
729 		skb = skb_dequeue(&ch->collect_queue);
730 		ch->collect_len -= skb->len;
731 		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
732 	}
733 
734 	p_header = (struct pdu *)skb->data;
735 	p_header->pdu_flag |= PDU_LAST;
736 
737 	ch->prof.txlen += skb->len - PDU_HEADER_LENGTH;
738 
739 	/* put the TH on the packet */
740 	header = skb_push(skb, TH_HEADER_LENGTH);
741 	memset(header, 0, TH_HEADER_LENGTH);
742 
743 	header->th_ch_flag = TH_HAS_PDU;  /* Normal data */
744 	ch->th_seq_num++;
745 	header->th_seq_num = ch->th_seq_num;
746 
747 	CTCM_PR_DBGDATA("%s(%s) ToVTAM_th_seq= %08x\n" ,
748 		       __func__, dev->name, ch->th_seq_num);
749 
750 	CTCM_PR_DBGDATA("%s(%s): skb len: %04x\n - pdu header and data for "
751 			"up to 32 bytes sent to vtam:\n",
752 				__func__, dev->name, skb->len);
753 	CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
754 
755 	ch->ccw[4].count = skb->len;
756 	if (set_normalized_cda(&ch->ccw[4], skb->data)) {
757 		/*
758 		 * idal allocation failed, try via copying to trans_skb.
759 		 * trans_skb usually has a pre-allocated idal.
760 		 */
761 		if (ctcm_checkalloc_buffer(ch)) {
762 			/*
763 			 * Remove our header.
764 			 * It gets added again on retransmit.
765 			 */
766 				goto nomem_exit;
767 		}
768 
769 		skb_reset_tail_pointer(ch->trans_skb);
770 		ch->trans_skb->len = 0;
771 		ch->ccw[1].count = skb->len;
772 		skb_put_data(ch->trans_skb, skb->data, skb->len);
773 		refcount_dec(&skb->users);
774 		dev_kfree_skb_irq(skb);
775 		ccw_idx = 0;
776 		CTCM_PR_DBGDATA("%s(%s): trans_skb len: %04x\n"
777 				"up to 32 bytes sent to vtam:\n",
778 				__func__, dev->name, ch->trans_skb->len);
779 		CTCM_D3_DUMP((char *)ch->trans_skb->data,
780 				min_t(int, 32, ch->trans_skb->len));
781 	} else {
782 		skb_queue_tail(&ch->io_queue, skb);
783 		ccw_idx = 3;
784 	}
785 	ch->retry = 0;
786 	fsm_newstate(ch->fsm, CTC_STATE_TX);
787 	fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
788 
789 	if (do_debug_ccw)
790 		ctcmpc_dumpit((char *)&ch->ccw[ccw_idx],
791 					sizeof(struct ccw1) * 3);
792 
793 	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
794 	ch->prof.send_stamp = jiffies;
795 	rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx], 0, 0xff, 0);
796 	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
797 	if (ccw_idx == 3)
798 		ch->prof.doios_single++;
799 	if (rc != 0) {
800 		fsm_deltimer(&ch->timer);
801 		ctcm_ccw_check_rc(ch, rc, "single skb TX");
802 		if (ccw_idx == 3)
803 			skb_dequeue_tail(&ch->io_queue);
804 	} else if (ccw_idx == 0) {
805 		priv->stats.tx_packets++;
806 		priv->stats.tx_bytes += skb->len - TH_HEADER_LENGTH;
807 	}
808 	if (ch->th_seq_num > 0xf0000000)	/* Chose at random. */
809 		ctcmpc_send_sweep_req(ch);
810 
811 	goto done;
812 nomem_exit:
813 	CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_CRIT,
814 			"%s(%s): MEMORY allocation ERROR\n",
815 			CTCM_FUNTAIL, ch->id);
816 	rc = -ENOMEM;
817 	refcount_dec(&skb->users);
818 	dev_kfree_skb_any(skb);
819 	fsm_event(priv->mpcg->fsm, MPCG_EVENT_INOP, dev);
820 done:
821 	CTCM_PR_DEBUG("Exit %s(%s)\n", __func__, dev->name);
822 	return rc;
823 }
824 
825 /*
826  * Start transmission of a packet.
827  * Called from generic network device layer.
828  */
829 /* first merge version - leaving both functions separated */
830 static netdev_tx_t ctcm_tx(struct sk_buff *skb, struct net_device *dev)
831 {
832 	struct ctcm_priv *priv = dev->ml_priv;
833 
834 	if (skb == NULL) {
835 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
836 				"%s(%s): NULL sk_buff passed",
837 					CTCM_FUNTAIL, dev->name);
838 		priv->stats.tx_dropped++;
839 		return NETDEV_TX_OK;
840 	}
841 	if (skb_headroom(skb) < (LL_HEADER_LENGTH + 2)) {
842 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
843 			"%s(%s): Got sk_buff with head room < %ld bytes",
844 			CTCM_FUNTAIL, dev->name, LL_HEADER_LENGTH + 2);
845 		dev_kfree_skb(skb);
846 		priv->stats.tx_dropped++;
847 		return NETDEV_TX_OK;
848 	}
849 
850 	/*
851 	 * If channels are not running, try to restart them
852 	 * and throw away packet.
853 	 */
854 	if (fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) {
855 		fsm_event(priv->fsm, DEV_EVENT_START, dev);
856 		dev_kfree_skb(skb);
857 		priv->stats.tx_dropped++;
858 		priv->stats.tx_errors++;
859 		priv->stats.tx_carrier_errors++;
860 		return NETDEV_TX_OK;
861 	}
862 
863 	if (ctcm_test_and_set_busy(dev))
864 		return NETDEV_TX_BUSY;
865 
866 	netif_trans_update(dev);
867 	if (ctcm_transmit_skb(priv->channel[CTCM_WRITE], skb) != 0)
868 		return NETDEV_TX_BUSY;
869 	return NETDEV_TX_OK;
870 }
871 
872 /* unmerged MPC variant of ctcm_tx */
873 static netdev_tx_t ctcmpc_tx(struct sk_buff *skb, struct net_device *dev)
874 {
875 	int len = 0;
876 	struct ctcm_priv *priv = dev->ml_priv;
877 	struct mpc_group *grp  = priv->mpcg;
878 	struct sk_buff *newskb = NULL;
879 
880 	/*
881 	 * Some sanity checks ...
882 	 */
883 	if (skb == NULL) {
884 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
885 			"%s(%s): NULL sk_buff passed",
886 					CTCM_FUNTAIL, dev->name);
887 		priv->stats.tx_dropped++;
888 		goto done;
889 	}
890 	if (skb_headroom(skb) < (TH_HEADER_LENGTH + PDU_HEADER_LENGTH)) {
891 		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
892 			"%s(%s): Got sk_buff with head room < %ld bytes",
893 			CTCM_FUNTAIL, dev->name,
894 				TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
895 
896 		CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
897 
898 		len =  skb->len + TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
899 		newskb = __dev_alloc_skb(len, GFP_ATOMIC | GFP_DMA);
900 
901 		if (!newskb) {
902 			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
903 				"%s: %s: __dev_alloc_skb failed",
904 						__func__, dev->name);
905 
906 			dev_kfree_skb_any(skb);
907 			priv->stats.tx_dropped++;
908 			priv->stats.tx_errors++;
909 			priv->stats.tx_carrier_errors++;
910 			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
911 			goto done;
912 		}
913 		newskb->protocol = skb->protocol;
914 		skb_reserve(newskb, TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
915 		skb_put_data(newskb, skb->data, skb->len);
916 		dev_kfree_skb_any(skb);
917 		skb = newskb;
918 	}
919 
920 	/*
921 	 * If channels are not running,
922 	 * notify anybody about a link failure and throw
923 	 * away packet.
924 	 */
925 	if ((fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) ||
926 	   (fsm_getstate(grp->fsm) <  MPCG_STATE_XID2INITW)) {
927 		dev_kfree_skb_any(skb);
928 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
929 			"%s(%s): inactive MPCGROUP - dropped",
930 					CTCM_FUNTAIL, dev->name);
931 		priv->stats.tx_dropped++;
932 		priv->stats.tx_errors++;
933 		priv->stats.tx_carrier_errors++;
934 		goto done;
935 	}
936 
937 	if (ctcm_test_and_set_busy(dev)) {
938 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
939 			"%s(%s): device busy - dropped",
940 					CTCM_FUNTAIL, dev->name);
941 		dev_kfree_skb_any(skb);
942 		priv->stats.tx_dropped++;
943 		priv->stats.tx_errors++;
944 		priv->stats.tx_carrier_errors++;
945 		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
946 		goto done;
947 	}
948 
949 	netif_trans_update(dev);
950 	if (ctcmpc_transmit_skb(priv->channel[CTCM_WRITE], skb) != 0) {
951 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
952 			"%s(%s): device error - dropped",
953 					CTCM_FUNTAIL, dev->name);
954 		dev_kfree_skb_any(skb);
955 		priv->stats.tx_dropped++;
956 		priv->stats.tx_errors++;
957 		priv->stats.tx_carrier_errors++;
958 		ctcm_clear_busy(dev);
959 		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
960 		goto done;
961 	}
962 	ctcm_clear_busy(dev);
963 done:
964 	if (do_debug)
965 		MPC_DBF_DEV_NAME(TRACE, dev, "exit");
966 
967 	return NETDEV_TX_OK;	/* handle freeing of skb here */
968 }
969 
970 
971 /*
972  * Sets MTU of an interface.
973  *
974  *  dev		Pointer to interface struct.
975  *  new_mtu	The new MTU to use for this interface.
976  *
977  * returns 0 on success, -EINVAL if MTU is out of valid range.
978  *         (valid range is 576 .. 65527). If VM is on the
979  *         remote side, maximum MTU is 32760, however this is
980  *         not checked here.
981  */
982 static int ctcm_change_mtu(struct net_device *dev, int new_mtu)
983 {
984 	struct ctcm_priv *priv;
985 	int max_bufsize;
986 
987 	priv = dev->ml_priv;
988 	max_bufsize = priv->channel[CTCM_READ]->max_bufsize;
989 
990 	if (IS_MPC(priv)) {
991 		if (new_mtu > max_bufsize - TH_HEADER_LENGTH)
992 			return -EINVAL;
993 		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
994 	} else {
995 		if (new_mtu > max_bufsize - LL_HEADER_LENGTH - 2)
996 			return -EINVAL;
997 		dev->hard_header_len = LL_HEADER_LENGTH + 2;
998 	}
999 	dev->mtu = new_mtu;
1000 	return 0;
1001 }
1002 
1003 /*
1004  * Returns interface statistics of a device.
1005  *
1006  *  dev		Pointer to interface struct.
1007  *
1008  * returns Pointer to stats struct of this interface.
1009  */
1010 static struct net_device_stats *ctcm_stats(struct net_device *dev)
1011 {
1012 	return &((struct ctcm_priv *)dev->ml_priv)->stats;
1013 }
1014 
1015 static void ctcm_free_netdevice(struct net_device *dev)
1016 {
1017 	struct ctcm_priv *priv;
1018 	struct mpc_group *grp;
1019 
1020 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1021 			"%s(%s)", CTCM_FUNTAIL, dev->name);
1022 	priv = dev->ml_priv;
1023 	if (priv) {
1024 		grp = priv->mpcg;
1025 		if (grp) {
1026 			if (grp->fsm)
1027 				kfree_fsm(grp->fsm);
1028 			dev_kfree_skb(grp->xid_skb);
1029 			dev_kfree_skb(grp->rcvd_xid_skb);
1030 			tasklet_kill(&grp->mpc_tasklet2);
1031 			kfree(grp);
1032 			priv->mpcg = NULL;
1033 		}
1034 		if (priv->fsm) {
1035 			kfree_fsm(priv->fsm);
1036 			priv->fsm = NULL;
1037 		}
1038 		kfree(priv->xid);
1039 		priv->xid = NULL;
1040 	/*
1041 	 * Note: kfree(priv); is done in "opposite" function of
1042 	 * allocator function probe_device which is remove_device.
1043 	 */
1044 	}
1045 #ifdef MODULE
1046 	free_netdev(dev);
1047 #endif
1048 }
1049 
1050 struct mpc_group *ctcmpc_init_mpc_group(struct ctcm_priv *priv);
1051 
1052 static const struct net_device_ops ctcm_netdev_ops = {
1053 	.ndo_open		= ctcm_open,
1054 	.ndo_stop		= ctcm_close,
1055 	.ndo_get_stats		= ctcm_stats,
1056 	.ndo_change_mtu	   	= ctcm_change_mtu,
1057 	.ndo_start_xmit		= ctcm_tx,
1058 };
1059 
1060 static const struct net_device_ops ctcm_mpc_netdev_ops = {
1061 	.ndo_open		= ctcm_open,
1062 	.ndo_stop		= ctcm_close,
1063 	.ndo_get_stats		= ctcm_stats,
1064 	.ndo_change_mtu	   	= ctcm_change_mtu,
1065 	.ndo_start_xmit		= ctcmpc_tx,
1066 };
1067 
1068 static void ctcm_dev_setup(struct net_device *dev)
1069 {
1070 	dev->type = ARPHRD_SLIP;
1071 	dev->tx_queue_len = 100;
1072 	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1073 	dev->min_mtu = 576;
1074 	dev->max_mtu = 65527;
1075 }
1076 
1077 /*
1078  * Initialize everything of the net device except the name and the
1079  * channel structs.
1080  */
1081 static struct net_device *ctcm_init_netdevice(struct ctcm_priv *priv)
1082 {
1083 	struct net_device *dev;
1084 	struct mpc_group *grp;
1085 	if (!priv)
1086 		return NULL;
1087 
1088 	if (IS_MPC(priv))
1089 		dev = alloc_netdev(0, MPC_DEVICE_GENE, NET_NAME_UNKNOWN,
1090 				   ctcm_dev_setup);
1091 	else
1092 		dev = alloc_netdev(0, CTC_DEVICE_GENE, NET_NAME_UNKNOWN,
1093 				   ctcm_dev_setup);
1094 
1095 	if (!dev) {
1096 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_CRIT,
1097 			"%s: MEMORY allocation ERROR",
1098 			CTCM_FUNTAIL);
1099 		return NULL;
1100 	}
1101 	dev->ml_priv = priv;
1102 	priv->fsm = init_fsm("ctcmdev", dev_state_names, dev_event_names,
1103 				CTCM_NR_DEV_STATES, CTCM_NR_DEV_EVENTS,
1104 				dev_fsm, dev_fsm_len, GFP_KERNEL);
1105 	if (priv->fsm == NULL) {
1106 		CTCMY_DBF_DEV(SETUP, dev, "init_fsm error");
1107 		free_netdev(dev);
1108 		return NULL;
1109 	}
1110 	fsm_newstate(priv->fsm, DEV_STATE_STOPPED);
1111 	fsm_settimer(priv->fsm, &priv->restart_timer);
1112 
1113 	if (IS_MPC(priv)) {
1114 		/*  MPC Group Initializations  */
1115 		grp = ctcmpc_init_mpc_group(priv);
1116 		if (grp == NULL) {
1117 			MPC_DBF_DEV(SETUP, dev, "init_mpc_group error");
1118 			free_netdev(dev);
1119 			return NULL;
1120 		}
1121 		tasklet_init(&grp->mpc_tasklet2,
1122 				mpc_group_ready, (unsigned long)dev);
1123 		dev->mtu = MPC_BUFSIZE_DEFAULT -
1124 				TH_HEADER_LENGTH - PDU_HEADER_LENGTH;
1125 
1126 		dev->netdev_ops = &ctcm_mpc_netdev_ops;
1127 		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
1128 		priv->buffer_size = MPC_BUFSIZE_DEFAULT;
1129 	} else {
1130 		dev->mtu = CTCM_BUFSIZE_DEFAULT - LL_HEADER_LENGTH - 2;
1131 		dev->netdev_ops = &ctcm_netdev_ops;
1132 		dev->hard_header_len = LL_HEADER_LENGTH + 2;
1133 	}
1134 
1135 	CTCMY_DBF_DEV(SETUP, dev, "finished");
1136 
1137 	return dev;
1138 }
1139 
1140 /*
1141  * Main IRQ handler.
1142  *
1143  *  cdev	The ccw_device the interrupt is for.
1144  *  intparm	interruption parameter.
1145  *  irb		interruption response block.
1146  */
1147 static void ctcm_irq_handler(struct ccw_device *cdev,
1148 				unsigned long intparm, struct irb *irb)
1149 {
1150 	struct channel		*ch;
1151 	struct net_device	*dev;
1152 	struct ctcm_priv	*priv;
1153 	struct ccwgroup_device	*cgdev;
1154 	int cstat;
1155 	int dstat;
1156 
1157 	CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
1158 		"Enter %s(%s)", CTCM_FUNTAIL, dev_name(&cdev->dev));
1159 
1160 	if (ctcm_check_irb_error(cdev, irb))
1161 		return;
1162 
1163 	cgdev = dev_get_drvdata(&cdev->dev);
1164 
1165 	cstat = irb->scsw.cmd.cstat;
1166 	dstat = irb->scsw.cmd.dstat;
1167 
1168 	/* Check for unsolicited interrupts. */
1169 	if (cgdev == NULL) {
1170 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_ERROR,
1171 			"%s(%s) unsolicited irq: c-%02x d-%02x\n",
1172 			CTCM_FUNTAIL, dev_name(&cdev->dev), cstat, dstat);
1173 		dev_warn(&cdev->dev,
1174 			"The adapter received a non-specific IRQ\n");
1175 		return;
1176 	}
1177 
1178 	priv = dev_get_drvdata(&cgdev->dev);
1179 
1180 	/* Try to extract channel from driver data. */
1181 	if (priv->channel[CTCM_READ]->cdev == cdev)
1182 		ch = priv->channel[CTCM_READ];
1183 	else if (priv->channel[CTCM_WRITE]->cdev == cdev)
1184 		ch = priv->channel[CTCM_WRITE];
1185 	else {
1186 		dev_err(&cdev->dev,
1187 			"%s: Internal error: Can't determine channel for "
1188 			"interrupt device %s\n",
1189 			__func__, dev_name(&cdev->dev));
1190 			/* Explain: inconsistent internal structures */
1191 		return;
1192 	}
1193 
1194 	dev = ch->netdev;
1195 	if (dev == NULL) {
1196 		dev_err(&cdev->dev,
1197 			"%s Internal error: net_device is NULL, ch = 0x%p\n",
1198 			__func__, ch);
1199 			/* Explain: inconsistent internal structures */
1200 		return;
1201 	}
1202 
1203 	/* Copy interruption response block. */
1204 	memcpy(ch->irb, irb, sizeof(struct irb));
1205 
1206 	/* Issue error message and return on subchannel error code */
1207 	if (irb->scsw.cmd.cstat) {
1208 		fsm_event(ch->fsm, CTC_EVENT_SC_UNKNOWN, ch);
1209 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
1210 			"%s(%s): sub-ch check %s: cs=%02x ds=%02x",
1211 				CTCM_FUNTAIL, dev->name, ch->id, cstat, dstat);
1212 		dev_warn(&cdev->dev,
1213 				"A check occurred on the subchannel\n");
1214 		return;
1215 	}
1216 
1217 	/* Check the reason-code of a unit check */
1218 	if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
1219 		if ((irb->ecw[0] & ch->sense_rc) == 0)
1220 			/* print it only once */
1221 			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
1222 				"%s(%s): sense=%02x, ds=%02x",
1223 				CTCM_FUNTAIL, ch->id, irb->ecw[0], dstat);
1224 		ccw_unit_check(ch, irb->ecw[0]);
1225 		return;
1226 	}
1227 	if (irb->scsw.cmd.dstat & DEV_STAT_BUSY) {
1228 		if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
1229 			fsm_event(ch->fsm, CTC_EVENT_ATTNBUSY, ch);
1230 		else
1231 			fsm_event(ch->fsm, CTC_EVENT_BUSY, ch);
1232 		return;
1233 	}
1234 	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
1235 		fsm_event(ch->fsm, CTC_EVENT_ATTN, ch);
1236 		return;
1237 	}
1238 	if ((irb->scsw.cmd.stctl & SCSW_STCTL_SEC_STATUS) ||
1239 	    (irb->scsw.cmd.stctl == SCSW_STCTL_STATUS_PEND) ||
1240 	    (irb->scsw.cmd.stctl ==
1241 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)))
1242 		fsm_event(ch->fsm, CTC_EVENT_FINSTAT, ch);
1243 	else
1244 		fsm_event(ch->fsm, CTC_EVENT_IRQ, ch);
1245 
1246 }
1247 
1248 static const struct device_type ctcm_devtype = {
1249 	.name = "ctcm",
1250 	.groups = ctcm_attr_groups,
1251 };
1252 
1253 /*
1254  * Add ctcm specific attributes.
1255  * Add ctcm private data.
1256  *
1257  *  cgdev	pointer to ccwgroup_device just added
1258  *
1259  * returns 0 on success, !0 on failure.
1260  */
1261 static int ctcm_probe_device(struct ccwgroup_device *cgdev)
1262 {
1263 	struct ctcm_priv *priv;
1264 
1265 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1266 			"%s %p",
1267 			__func__, cgdev);
1268 
1269 	if (!get_device(&cgdev->dev))
1270 		return -ENODEV;
1271 
1272 	priv = kzalloc(sizeof(struct ctcm_priv), GFP_KERNEL);
1273 	if (!priv) {
1274 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
1275 			"%s: memory allocation failure",
1276 			CTCM_FUNTAIL);
1277 		put_device(&cgdev->dev);
1278 		return -ENOMEM;
1279 	}
1280 	priv->buffer_size = CTCM_BUFSIZE_DEFAULT;
1281 	cgdev->cdev[0]->handler = ctcm_irq_handler;
1282 	cgdev->cdev[1]->handler = ctcm_irq_handler;
1283 	dev_set_drvdata(&cgdev->dev, priv);
1284 	cgdev->dev.type = &ctcm_devtype;
1285 
1286 	return 0;
1287 }
1288 
1289 /*
1290  * Add a new channel to the list of channels.
1291  * Keeps the channel list sorted.
1292  *
1293  *  cdev	The ccw_device to be added.
1294  *  type	The type class of the new channel.
1295  *  priv	Points to the private data of the ccwgroup_device.
1296  *
1297  * returns 0 on success, !0 on error.
1298  */
1299 static int add_channel(struct ccw_device *cdev, enum ctcm_channel_types type,
1300 				struct ctcm_priv *priv)
1301 {
1302 	struct channel **c = &channels;
1303 	struct channel *ch;
1304 	int ccw_num;
1305 	int rc = 0;
1306 
1307 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1308 		"%s(%s), type %d, proto %d",
1309 			__func__, dev_name(&cdev->dev),	type, priv->protocol);
1310 
1311 	ch = kzalloc(sizeof(struct channel), GFP_KERNEL);
1312 	if (ch == NULL)
1313 		return -ENOMEM;
1314 
1315 	ch->protocol = priv->protocol;
1316 	if (IS_MPC(priv)) {
1317 		ch->discontact_th = kzalloc(TH_HEADER_LENGTH, GFP_KERNEL);
1318 		if (ch->discontact_th == NULL)
1319 					goto nomem_return;
1320 
1321 		ch->discontact_th->th_blk_flag = TH_DISCONTACT;
1322 		tasklet_init(&ch->ch_disc_tasklet,
1323 			mpc_action_send_discontact, (unsigned long)ch);
1324 
1325 		tasklet_init(&ch->ch_tasklet, ctcmpc_bh, (unsigned long)ch);
1326 		ch->max_bufsize = (MPC_BUFSIZE_DEFAULT - 35);
1327 		ccw_num = 17;
1328 	} else
1329 		ccw_num = 8;
1330 
1331 	ch->ccw = kcalloc(ccw_num, sizeof(struct ccw1), GFP_KERNEL | GFP_DMA);
1332 	if (ch->ccw == NULL)
1333 					goto nomem_return;
1334 
1335 	ch->cdev = cdev;
1336 	scnprintf(ch->id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev->dev));
1337 	ch->type = type;
1338 
1339 	/*
1340 	 * "static" ccws are used in the following way:
1341 	 *
1342 	 * ccw[0..2] (Channel program for generic I/O):
1343 	 *           0: prepare
1344 	 *           1: read or write (depending on direction) with fixed
1345 	 *              buffer (idal allocated once when buffer is allocated)
1346 	 *           2: nop
1347 	 * ccw[3..5] (Channel program for direct write of packets)
1348 	 *           3: prepare
1349 	 *           4: write (idal allocated on every write).
1350 	 *           5: nop
1351 	 * ccw[6..7] (Channel program for initial channel setup):
1352 	 *           6: set extended mode
1353 	 *           7: nop
1354 	 *
1355 	 * ch->ccw[0..5] are initialized in ch_action_start because
1356 	 * the channel's direction is yet unknown here.
1357 	 *
1358 	 * ccws used for xid2 negotiations
1359 	 *  ch-ccw[8-14] need to be used for the XID exchange either
1360 	 *    X side XID2 Processing
1361 	 *       8:  write control
1362 	 *       9:  write th
1363 	 *	     10: write XID
1364 	 *	     11: read th from secondary
1365 	 *	     12: read XID   from secondary
1366 	 *	     13: read 4 byte ID
1367 	 *	     14: nop
1368 	 *    Y side XID Processing
1369 	 *	     8:  sense
1370 	 *       9:  read th
1371 	 *	     10: read XID
1372 	 *	     11: write th
1373 	 *	     12: write XID
1374 	 *	     13: write 4 byte ID
1375 	 *	     14: nop
1376 	 *
1377 	 *  ccws used for double noop due to VM timing issues
1378 	 *  which result in unrecoverable Busy on channel
1379 	 *       15: nop
1380 	 *       16: nop
1381 	 */
1382 	ch->ccw[6].cmd_code	= CCW_CMD_SET_EXTENDED;
1383 	ch->ccw[6].flags	= CCW_FLAG_SLI;
1384 
1385 	ch->ccw[7].cmd_code	= CCW_CMD_NOOP;
1386 	ch->ccw[7].flags	= CCW_FLAG_SLI;
1387 
1388 	if (IS_MPC(priv)) {
1389 		ch->ccw[15].cmd_code = CCW_CMD_WRITE;
1390 		ch->ccw[15].flags    = CCW_FLAG_SLI | CCW_FLAG_CC;
1391 		ch->ccw[15].count    = TH_HEADER_LENGTH;
1392 		ch->ccw[15].cda      = virt_to_phys(ch->discontact_th);
1393 
1394 		ch->ccw[16].cmd_code = CCW_CMD_NOOP;
1395 		ch->ccw[16].flags    = CCW_FLAG_SLI;
1396 
1397 		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
1398 				ctc_ch_event_names, CTC_MPC_NR_STATES,
1399 				CTC_MPC_NR_EVENTS, ctcmpc_ch_fsm,
1400 				mpc_ch_fsm_len, GFP_KERNEL);
1401 	} else {
1402 		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
1403 				ctc_ch_event_names, CTC_NR_STATES,
1404 				CTC_NR_EVENTS, ch_fsm,
1405 				ch_fsm_len, GFP_KERNEL);
1406 	}
1407 	if (ch->fsm == NULL)
1408 				goto nomem_return;
1409 
1410 	fsm_newstate(ch->fsm, CTC_STATE_IDLE);
1411 
1412 	ch->irb = kzalloc(sizeof(struct irb), GFP_KERNEL);
1413 	if (ch->irb == NULL)
1414 				goto nomem_return;
1415 
1416 	while (*c && ctcm_less_than((*c)->id, ch->id))
1417 		c = &(*c)->next;
1418 
1419 	if (*c && (!strncmp((*c)->id, ch->id, CTCM_ID_SIZE))) {
1420 		CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1421 				"%s (%s) already in list, using old entry",
1422 				__func__, (*c)->id);
1423 
1424 		goto free_return;
1425 	}
1426 
1427 	spin_lock_init(&ch->collect_lock);
1428 
1429 	fsm_settimer(ch->fsm, &ch->timer);
1430 	skb_queue_head_init(&ch->io_queue);
1431 	skb_queue_head_init(&ch->collect_queue);
1432 
1433 	if (IS_MPC(priv)) {
1434 		fsm_settimer(ch->fsm, &ch->sweep_timer);
1435 		skb_queue_head_init(&ch->sweep_queue);
1436 	}
1437 	ch->next = *c;
1438 	*c = ch;
1439 	return 0;
1440 
1441 nomem_return:
1442 	rc = -ENOMEM;
1443 
1444 free_return:	/* note that all channel pointers are 0 or valid */
1445 	kfree(ch->ccw);
1446 	kfree(ch->discontact_th);
1447 	kfree_fsm(ch->fsm);
1448 	kfree(ch->irb);
1449 	kfree(ch);
1450 	return rc;
1451 }
1452 
1453 /*
1454  * Return type of a detected device.
1455  */
1456 static enum ctcm_channel_types get_channel_type(struct ccw_device_id *id)
1457 {
1458 	enum ctcm_channel_types type;
1459 	type = (enum ctcm_channel_types)id->driver_info;
1460 
1461 	if (type == ctcm_channel_type_ficon)
1462 		type = ctcm_channel_type_escon;
1463 
1464 	return type;
1465 }
1466 
1467 /*
1468  *
1469  * Setup an interface.
1470  *
1471  *  cgdev	Device to be setup.
1472  *
1473  * returns 0 on success, !0 on failure.
1474  */
1475 static int ctcm_new_device(struct ccwgroup_device *cgdev)
1476 {
1477 	char read_id[CTCM_ID_SIZE];
1478 	char write_id[CTCM_ID_SIZE];
1479 	int direction;
1480 	enum ctcm_channel_types type;
1481 	struct ctcm_priv *priv;
1482 	struct net_device *dev;
1483 	struct ccw_device *cdev0;
1484 	struct ccw_device *cdev1;
1485 	struct channel *readc;
1486 	struct channel *writec;
1487 	int ret;
1488 	int result;
1489 
1490 	priv = dev_get_drvdata(&cgdev->dev);
1491 	if (!priv) {
1492 		result = -ENODEV;
1493 		goto out_err_result;
1494 	}
1495 
1496 	cdev0 = cgdev->cdev[0];
1497 	cdev1 = cgdev->cdev[1];
1498 
1499 	type = get_channel_type(&cdev0->id);
1500 
1501 	scnprintf(read_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev0->dev));
1502 	scnprintf(write_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev1->dev));
1503 
1504 	ret = add_channel(cdev0, type, priv);
1505 	if (ret) {
1506 		result = ret;
1507 		goto out_err_result;
1508 	}
1509 	ret = add_channel(cdev1, type, priv);
1510 	if (ret) {
1511 		result = ret;
1512 		goto out_remove_channel1;
1513 	}
1514 
1515 	ret = ccw_device_set_online(cdev0);
1516 	if (ret != 0) {
1517 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
1518 			"%s(%s) set_online rc=%d",
1519 				CTCM_FUNTAIL, read_id, ret);
1520 		result = -EIO;
1521 		goto out_remove_channel2;
1522 	}
1523 
1524 	ret = ccw_device_set_online(cdev1);
1525 	if (ret != 0) {
1526 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
1527 			"%s(%s) set_online rc=%d",
1528 				CTCM_FUNTAIL, write_id, ret);
1529 
1530 		result = -EIO;
1531 		goto out_ccw1;
1532 	}
1533 
1534 	dev = ctcm_init_netdevice(priv);
1535 	if (dev == NULL) {
1536 		result = -ENODEV;
1537 		goto out_ccw2;
1538 	}
1539 
1540 	for (direction = CTCM_READ; direction <= CTCM_WRITE; direction++) {
1541 		priv->channel[direction] =
1542 			channel_get(type, direction == CTCM_READ ?
1543 				read_id : write_id, direction);
1544 		if (priv->channel[direction] == NULL) {
1545 			if (direction == CTCM_WRITE)
1546 				channel_free(priv->channel[CTCM_READ]);
1547 			result = -ENODEV;
1548 			goto out_dev;
1549 		}
1550 		priv->channel[direction]->netdev = dev;
1551 		priv->channel[direction]->protocol = priv->protocol;
1552 		priv->channel[direction]->max_bufsize = priv->buffer_size;
1553 	}
1554 	/* sysfs magic */
1555 	SET_NETDEV_DEV(dev, &cgdev->dev);
1556 
1557 	if (register_netdev(dev)) {
1558 		result = -ENODEV;
1559 		goto out_dev;
1560 	}
1561 
1562 	strscpy(priv->fsm->name, dev->name, sizeof(priv->fsm->name));
1563 
1564 	dev_info(&dev->dev,
1565 		"setup OK : r/w = %s/%s, protocol : %d\n",
1566 			priv->channel[CTCM_READ]->id,
1567 			priv->channel[CTCM_WRITE]->id, priv->protocol);
1568 
1569 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1570 		"setup(%s) OK : r/w = %s/%s, protocol : %d", dev->name,
1571 			priv->channel[CTCM_READ]->id,
1572 			priv->channel[CTCM_WRITE]->id, priv->protocol);
1573 
1574 	return 0;
1575 out_dev:
1576 	ctcm_free_netdevice(dev);
1577 out_ccw2:
1578 	ccw_device_set_offline(cgdev->cdev[1]);
1579 out_ccw1:
1580 	ccw_device_set_offline(cgdev->cdev[0]);
1581 out_remove_channel2:
1582 	readc = channel_get(type, read_id, CTCM_READ);
1583 	channel_remove(readc);
1584 out_remove_channel1:
1585 	writec = channel_get(type, write_id, CTCM_WRITE);
1586 	channel_remove(writec);
1587 out_err_result:
1588 	return result;
1589 }
1590 
1591 /*
1592  * Shutdown an interface.
1593  *
1594  *  cgdev	Device to be shut down.
1595  *
1596  * returns 0 on success, !0 on failure.
1597  */
1598 static int ctcm_shutdown_device(struct ccwgroup_device *cgdev)
1599 {
1600 	struct ctcm_priv *priv;
1601 	struct net_device *dev;
1602 
1603 	priv = dev_get_drvdata(&cgdev->dev);
1604 	if (!priv)
1605 		return -ENODEV;
1606 
1607 	if (priv->channel[CTCM_READ]) {
1608 		dev = priv->channel[CTCM_READ]->netdev;
1609 		CTCM_DBF_DEV(SETUP, dev, "");
1610 		/* Close the device */
1611 		ctcm_close(dev);
1612 		dev->flags &= ~IFF_RUNNING;
1613 		channel_free(priv->channel[CTCM_READ]);
1614 	} else
1615 		dev = NULL;
1616 
1617 	if (priv->channel[CTCM_WRITE])
1618 		channel_free(priv->channel[CTCM_WRITE]);
1619 
1620 	if (dev) {
1621 		unregister_netdev(dev);
1622 		ctcm_free_netdevice(dev);
1623 	}
1624 
1625 	if (priv->fsm)
1626 		kfree_fsm(priv->fsm);
1627 
1628 	ccw_device_set_offline(cgdev->cdev[1]);
1629 	ccw_device_set_offline(cgdev->cdev[0]);
1630 	channel_remove(priv->channel[CTCM_READ]);
1631 	channel_remove(priv->channel[CTCM_WRITE]);
1632 	priv->channel[CTCM_READ] = priv->channel[CTCM_WRITE] = NULL;
1633 
1634 	return 0;
1635 
1636 }
1637 
1638 
1639 static void ctcm_remove_device(struct ccwgroup_device *cgdev)
1640 {
1641 	struct ctcm_priv *priv = dev_get_drvdata(&cgdev->dev);
1642 
1643 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1644 			"removing device %p, proto : %d",
1645 			cgdev, priv->protocol);
1646 
1647 	if (cgdev->state == CCWGROUP_ONLINE)
1648 		ctcm_shutdown_device(cgdev);
1649 	dev_set_drvdata(&cgdev->dev, NULL);
1650 	kfree(priv);
1651 	put_device(&cgdev->dev);
1652 }
1653 
1654 static struct ccw_device_id ctcm_ids[] = {
1655 	{CCW_DEVICE(0x3088, 0x08), .driver_info = ctcm_channel_type_parallel},
1656 	{CCW_DEVICE(0x3088, 0x1e), .driver_info = ctcm_channel_type_ficon},
1657 	{CCW_DEVICE(0x3088, 0x1f), .driver_info = ctcm_channel_type_escon},
1658 	{},
1659 };
1660 MODULE_DEVICE_TABLE(ccw, ctcm_ids);
1661 
1662 static struct ccw_driver ctcm_ccw_driver = {
1663 	.driver = {
1664 		.owner	= THIS_MODULE,
1665 		.name	= "ctcm",
1666 	},
1667 	.ids	= ctcm_ids,
1668 	.probe	= ccwgroup_probe_ccwdev,
1669 	.remove	= ccwgroup_remove_ccwdev,
1670 	.int_class = IRQIO_CTC,
1671 };
1672 
1673 static struct ccwgroup_driver ctcm_group_driver = {
1674 	.driver = {
1675 		.owner	= THIS_MODULE,
1676 		.name	= CTC_DRIVER_NAME,
1677 	},
1678 	.ccw_driver  = &ctcm_ccw_driver,
1679 	.setup	     = ctcm_probe_device,
1680 	.remove      = ctcm_remove_device,
1681 	.set_online  = ctcm_new_device,
1682 	.set_offline = ctcm_shutdown_device,
1683 };
1684 
1685 static ssize_t group_store(struct device_driver *ddrv, const char *buf,
1686 			   size_t count)
1687 {
1688 	int err;
1689 
1690 	err = ccwgroup_create_dev(ctcm_root_dev, &ctcm_group_driver, 2, buf);
1691 	return err ? err : count;
1692 }
1693 static DRIVER_ATTR_WO(group);
1694 
1695 static struct attribute *ctcm_drv_attrs[] = {
1696 	&driver_attr_group.attr,
1697 	NULL,
1698 };
1699 static struct attribute_group ctcm_drv_attr_group = {
1700 	.attrs = ctcm_drv_attrs,
1701 };
1702 static const struct attribute_group *ctcm_drv_attr_groups[] = {
1703 	&ctcm_drv_attr_group,
1704 	NULL,
1705 };
1706 
1707 /*
1708  * Module related routines
1709  */
1710 
1711 /*
1712  * Prepare to be unloaded. Free IRQ's and release all resources.
1713  * This is called just before this module is unloaded. It is
1714  * not called, if the usage count is !0, so we don't need to check
1715  * for that.
1716  */
1717 static void __exit ctcm_exit(void)
1718 {
1719 	ccwgroup_driver_unregister(&ctcm_group_driver);
1720 	ccw_driver_unregister(&ctcm_ccw_driver);
1721 	root_device_unregister(ctcm_root_dev);
1722 	ctcm_unregister_dbf_views();
1723 	pr_info("CTCM driver unloaded\n");
1724 }
1725 
1726 /*
1727  * Print Banner.
1728  */
1729 static void print_banner(void)
1730 {
1731 	pr_info("CTCM driver initialized\n");
1732 }
1733 
1734 /*
1735  * Initialize module.
1736  * This is called just after the module is loaded.
1737  *
1738  * returns 0 on success, !0 on error.
1739  */
1740 static int __init ctcm_init(void)
1741 {
1742 	int ret;
1743 
1744 	channels = NULL;
1745 
1746 	ret = ctcm_register_dbf_views();
1747 	if (ret)
1748 		goto out_err;
1749 	ctcm_root_dev = root_device_register("ctcm");
1750 	ret = PTR_ERR_OR_ZERO(ctcm_root_dev);
1751 	if (ret)
1752 		goto register_err;
1753 	ret = ccw_driver_register(&ctcm_ccw_driver);
1754 	if (ret)
1755 		goto ccw_err;
1756 	ctcm_group_driver.driver.groups = ctcm_drv_attr_groups;
1757 	ret = ccwgroup_driver_register(&ctcm_group_driver);
1758 	if (ret)
1759 		goto ccwgroup_err;
1760 	print_banner();
1761 	return 0;
1762 
1763 ccwgroup_err:
1764 	ccw_driver_unregister(&ctcm_ccw_driver);
1765 ccw_err:
1766 	root_device_unregister(ctcm_root_dev);
1767 register_err:
1768 	ctcm_unregister_dbf_views();
1769 out_err:
1770 	pr_err("%s / Initializing the ctcm device driver failed, ret = %d\n",
1771 		__func__, ret);
1772 	return ret;
1773 }
1774 
1775 module_init(ctcm_init);
1776 module_exit(ctcm_exit);
1777 
1778 MODULE_AUTHOR("Peter Tiedemann <ptiedem@de.ibm.com>");
1779 MODULE_DESCRIPTION("Network driver for S/390 CTC + CTCMPC (SNA)");
1780 MODULE_LICENSE("GPL");
1781 
1782