xref: /openbmc/linux/drivers/s390/net/ctcm_main.c (revision c9933d49)
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+1];
204 	int ok = 0;
205 
206 	if (ch == NULL)
207 		return;
208 	else
209 		strncpy(chid, ch->id, CTCM_ID_SIZE);
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  *  skb		Pointer to buffer containing the packet.
830  *  dev		Pointer to interface struct.
831  *
832  * returns 0 if packet consumed, !0 if packet rejected.
833  *         Note: If we return !0, then the packet is free'd by
834  *               the generic network layer.
835  */
836 /* first merge version - leaving both functions separated */
837 static int ctcm_tx(struct sk_buff *skb, struct net_device *dev)
838 {
839 	struct ctcm_priv *priv = dev->ml_priv;
840 
841 	if (skb == NULL) {
842 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
843 				"%s(%s): NULL sk_buff passed",
844 					CTCM_FUNTAIL, dev->name);
845 		priv->stats.tx_dropped++;
846 		return NETDEV_TX_OK;
847 	}
848 	if (skb_headroom(skb) < (LL_HEADER_LENGTH + 2)) {
849 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
850 			"%s(%s): Got sk_buff with head room < %ld bytes",
851 			CTCM_FUNTAIL, dev->name, LL_HEADER_LENGTH + 2);
852 		dev_kfree_skb(skb);
853 		priv->stats.tx_dropped++;
854 		return NETDEV_TX_OK;
855 	}
856 
857 	/*
858 	 * If channels are not running, try to restart them
859 	 * and throw away packet.
860 	 */
861 	if (fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) {
862 		fsm_event(priv->fsm, DEV_EVENT_START, dev);
863 		dev_kfree_skb(skb);
864 		priv->stats.tx_dropped++;
865 		priv->stats.tx_errors++;
866 		priv->stats.tx_carrier_errors++;
867 		return NETDEV_TX_OK;
868 	}
869 
870 	if (ctcm_test_and_set_busy(dev))
871 		return NETDEV_TX_BUSY;
872 
873 	netif_trans_update(dev);
874 	if (ctcm_transmit_skb(priv->channel[CTCM_WRITE], skb) != 0)
875 		return NETDEV_TX_BUSY;
876 	return NETDEV_TX_OK;
877 }
878 
879 /* unmerged MPC variant of ctcm_tx */
880 static int ctcmpc_tx(struct sk_buff *skb, struct net_device *dev)
881 {
882 	int len = 0;
883 	struct ctcm_priv *priv = dev->ml_priv;
884 	struct mpc_group *grp  = priv->mpcg;
885 	struct sk_buff *newskb = NULL;
886 
887 	/*
888 	 * Some sanity checks ...
889 	 */
890 	if (skb == NULL) {
891 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
892 			"%s(%s): NULL sk_buff passed",
893 					CTCM_FUNTAIL, dev->name);
894 		priv->stats.tx_dropped++;
895 					goto done;
896 	}
897 	if (skb_headroom(skb) < (TH_HEADER_LENGTH + PDU_HEADER_LENGTH)) {
898 		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
899 			"%s(%s): Got sk_buff with head room < %ld bytes",
900 			CTCM_FUNTAIL, dev->name,
901 				TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
902 
903 		CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
904 
905 		len =  skb->len + TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
906 		newskb = __dev_alloc_skb(len, GFP_ATOMIC | GFP_DMA);
907 
908 		if (!newskb) {
909 			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
910 				"%s: %s: __dev_alloc_skb failed",
911 						__func__, dev->name);
912 
913 			dev_kfree_skb_any(skb);
914 			priv->stats.tx_dropped++;
915 			priv->stats.tx_errors++;
916 			priv->stats.tx_carrier_errors++;
917 			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
918 					goto done;
919 		}
920 		newskb->protocol = skb->protocol;
921 		skb_reserve(newskb, TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
922 		skb_put_data(newskb, skb->data, skb->len);
923 		dev_kfree_skb_any(skb);
924 		skb = newskb;
925 	}
926 
927 	/*
928 	 * If channels are not running,
929 	 * notify anybody about a link failure and throw
930 	 * away packet.
931 	 */
932 	if ((fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) ||
933 	   (fsm_getstate(grp->fsm) <  MPCG_STATE_XID2INITW)) {
934 		dev_kfree_skb_any(skb);
935 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
936 			"%s(%s): inactive MPCGROUP - dropped",
937 					CTCM_FUNTAIL, dev->name);
938 		priv->stats.tx_dropped++;
939 		priv->stats.tx_errors++;
940 		priv->stats.tx_carrier_errors++;
941 					goto done;
942 	}
943 
944 	if (ctcm_test_and_set_busy(dev)) {
945 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
946 			"%s(%s): device busy - dropped",
947 					CTCM_FUNTAIL, dev->name);
948 		dev_kfree_skb_any(skb);
949 		priv->stats.tx_dropped++;
950 		priv->stats.tx_errors++;
951 		priv->stats.tx_carrier_errors++;
952 		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
953 					goto done;
954 	}
955 
956 	netif_trans_update(dev);
957 	if (ctcmpc_transmit_skb(priv->channel[CTCM_WRITE], skb) != 0) {
958 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
959 			"%s(%s): device error - dropped",
960 					CTCM_FUNTAIL, dev->name);
961 		dev_kfree_skb_any(skb);
962 		priv->stats.tx_dropped++;
963 		priv->stats.tx_errors++;
964 		priv->stats.tx_carrier_errors++;
965 		ctcm_clear_busy(dev);
966 		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
967 					goto done;
968 	}
969 	ctcm_clear_busy(dev);
970 done:
971 	if (do_debug)
972 		MPC_DBF_DEV_NAME(TRACE, dev, "exit");
973 
974 	return NETDEV_TX_OK;	/* handle freeing of skb here */
975 }
976 
977 
978 /*
979  * Sets MTU of an interface.
980  *
981  *  dev		Pointer to interface struct.
982  *  new_mtu	The new MTU to use for this interface.
983  *
984  * returns 0 on success, -EINVAL if MTU is out of valid range.
985  *         (valid range is 576 .. 65527). If VM is on the
986  *         remote side, maximum MTU is 32760, however this is
987  *         not checked here.
988  */
989 static int ctcm_change_mtu(struct net_device *dev, int new_mtu)
990 {
991 	struct ctcm_priv *priv;
992 	int max_bufsize;
993 
994 	priv = dev->ml_priv;
995 	max_bufsize = priv->channel[CTCM_READ]->max_bufsize;
996 
997 	if (IS_MPC(priv)) {
998 		if (new_mtu > max_bufsize - TH_HEADER_LENGTH)
999 			return -EINVAL;
1000 		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
1001 	} else {
1002 		if (new_mtu > max_bufsize - LL_HEADER_LENGTH - 2)
1003 			return -EINVAL;
1004 		dev->hard_header_len = LL_HEADER_LENGTH + 2;
1005 	}
1006 	dev->mtu = new_mtu;
1007 	return 0;
1008 }
1009 
1010 /*
1011  * Returns interface statistics of a device.
1012  *
1013  *  dev		Pointer to interface struct.
1014  *
1015  * returns Pointer to stats struct of this interface.
1016  */
1017 static struct net_device_stats *ctcm_stats(struct net_device *dev)
1018 {
1019 	return &((struct ctcm_priv *)dev->ml_priv)->stats;
1020 }
1021 
1022 static void ctcm_free_netdevice(struct net_device *dev)
1023 {
1024 	struct ctcm_priv *priv;
1025 	struct mpc_group *grp;
1026 
1027 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1028 			"%s(%s)", CTCM_FUNTAIL, dev->name);
1029 	priv = dev->ml_priv;
1030 	if (priv) {
1031 		grp = priv->mpcg;
1032 		if (grp) {
1033 			if (grp->fsm)
1034 				kfree_fsm(grp->fsm);
1035 			dev_kfree_skb(grp->xid_skb);
1036 			dev_kfree_skb(grp->rcvd_xid_skb);
1037 			tasklet_kill(&grp->mpc_tasklet2);
1038 			kfree(grp);
1039 			priv->mpcg = NULL;
1040 		}
1041 		if (priv->fsm) {
1042 			kfree_fsm(priv->fsm);
1043 			priv->fsm = NULL;
1044 		}
1045 		kfree(priv->xid);
1046 		priv->xid = NULL;
1047 	/*
1048 	 * Note: kfree(priv); is done in "opposite" function of
1049 	 * allocator function probe_device which is remove_device.
1050 	 */
1051 	}
1052 #ifdef MODULE
1053 	free_netdev(dev);
1054 #endif
1055 }
1056 
1057 struct mpc_group *ctcmpc_init_mpc_group(struct ctcm_priv *priv);
1058 
1059 static const struct net_device_ops ctcm_netdev_ops = {
1060 	.ndo_open		= ctcm_open,
1061 	.ndo_stop		= ctcm_close,
1062 	.ndo_get_stats		= ctcm_stats,
1063 	.ndo_change_mtu	   	= ctcm_change_mtu,
1064 	.ndo_start_xmit		= ctcm_tx,
1065 };
1066 
1067 static const struct net_device_ops ctcm_mpc_netdev_ops = {
1068 	.ndo_open		= ctcm_open,
1069 	.ndo_stop		= ctcm_close,
1070 	.ndo_get_stats		= ctcm_stats,
1071 	.ndo_change_mtu	   	= ctcm_change_mtu,
1072 	.ndo_start_xmit		= ctcmpc_tx,
1073 };
1074 
1075 static void ctcm_dev_setup(struct net_device *dev)
1076 {
1077 	dev->type = ARPHRD_SLIP;
1078 	dev->tx_queue_len = 100;
1079 	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1080 	dev->min_mtu = 576;
1081 	dev->max_mtu = 65527;
1082 }
1083 
1084 /*
1085  * Initialize everything of the net device except the name and the
1086  * channel structs.
1087  */
1088 static struct net_device *ctcm_init_netdevice(struct ctcm_priv *priv)
1089 {
1090 	struct net_device *dev;
1091 	struct mpc_group *grp;
1092 	if (!priv)
1093 		return NULL;
1094 
1095 	if (IS_MPC(priv))
1096 		dev = alloc_netdev(0, MPC_DEVICE_GENE, NET_NAME_UNKNOWN,
1097 				   ctcm_dev_setup);
1098 	else
1099 		dev = alloc_netdev(0, CTC_DEVICE_GENE, NET_NAME_UNKNOWN,
1100 				   ctcm_dev_setup);
1101 
1102 	if (!dev) {
1103 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_CRIT,
1104 			"%s: MEMORY allocation ERROR",
1105 			CTCM_FUNTAIL);
1106 		return NULL;
1107 	}
1108 	dev->ml_priv = priv;
1109 	priv->fsm = init_fsm("ctcmdev", dev_state_names, dev_event_names,
1110 				CTCM_NR_DEV_STATES, CTCM_NR_DEV_EVENTS,
1111 				dev_fsm, dev_fsm_len, GFP_KERNEL);
1112 	if (priv->fsm == NULL) {
1113 		CTCMY_DBF_DEV(SETUP, dev, "init_fsm error");
1114 		free_netdev(dev);
1115 		return NULL;
1116 	}
1117 	fsm_newstate(priv->fsm, DEV_STATE_STOPPED);
1118 	fsm_settimer(priv->fsm, &priv->restart_timer);
1119 
1120 	if (IS_MPC(priv)) {
1121 		/*  MPC Group Initializations  */
1122 		grp = ctcmpc_init_mpc_group(priv);
1123 		if (grp == NULL) {
1124 			MPC_DBF_DEV(SETUP, dev, "init_mpc_group error");
1125 			free_netdev(dev);
1126 			return NULL;
1127 		}
1128 		tasklet_init(&grp->mpc_tasklet2,
1129 				mpc_group_ready, (unsigned long)dev);
1130 		dev->mtu = MPC_BUFSIZE_DEFAULT -
1131 				TH_HEADER_LENGTH - PDU_HEADER_LENGTH;
1132 
1133 		dev->netdev_ops = &ctcm_mpc_netdev_ops;
1134 		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
1135 		priv->buffer_size = MPC_BUFSIZE_DEFAULT;
1136 	} else {
1137 		dev->mtu = CTCM_BUFSIZE_DEFAULT - LL_HEADER_LENGTH - 2;
1138 		dev->netdev_ops = &ctcm_netdev_ops;
1139 		dev->hard_header_len = LL_HEADER_LENGTH + 2;
1140 	}
1141 
1142 	CTCMY_DBF_DEV(SETUP, dev, "finished");
1143 
1144 	return dev;
1145 }
1146 
1147 /*
1148  * Main IRQ handler.
1149  *
1150  *  cdev	The ccw_device the interrupt is for.
1151  *  intparm	interruption parameter.
1152  *  irb		interruption response block.
1153  */
1154 static void ctcm_irq_handler(struct ccw_device *cdev,
1155 				unsigned long intparm, struct irb *irb)
1156 {
1157 	struct channel		*ch;
1158 	struct net_device	*dev;
1159 	struct ctcm_priv	*priv;
1160 	struct ccwgroup_device	*cgdev;
1161 	int cstat;
1162 	int dstat;
1163 
1164 	CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
1165 		"Enter %s(%s)", CTCM_FUNTAIL, dev_name(&cdev->dev));
1166 
1167 	if (ctcm_check_irb_error(cdev, irb))
1168 		return;
1169 
1170 	cgdev = dev_get_drvdata(&cdev->dev);
1171 
1172 	cstat = irb->scsw.cmd.cstat;
1173 	dstat = irb->scsw.cmd.dstat;
1174 
1175 	/* Check for unsolicited interrupts. */
1176 	if (cgdev == NULL) {
1177 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_ERROR,
1178 			"%s(%s) unsolicited irq: c-%02x d-%02x\n",
1179 			CTCM_FUNTAIL, dev_name(&cdev->dev), cstat, dstat);
1180 		dev_warn(&cdev->dev,
1181 			"The adapter received a non-specific IRQ\n");
1182 		return;
1183 	}
1184 
1185 	priv = dev_get_drvdata(&cgdev->dev);
1186 
1187 	/* Try to extract channel from driver data. */
1188 	if (priv->channel[CTCM_READ]->cdev == cdev)
1189 		ch = priv->channel[CTCM_READ];
1190 	else if (priv->channel[CTCM_WRITE]->cdev == cdev)
1191 		ch = priv->channel[CTCM_WRITE];
1192 	else {
1193 		dev_err(&cdev->dev,
1194 			"%s: Internal error: Can't determine channel for "
1195 			"interrupt device %s\n",
1196 			__func__, dev_name(&cdev->dev));
1197 			/* Explain: inconsistent internal structures */
1198 		return;
1199 	}
1200 
1201 	dev = ch->netdev;
1202 	if (dev == NULL) {
1203 		dev_err(&cdev->dev,
1204 			"%s Internal error: net_device is NULL, ch = 0x%p\n",
1205 			__func__, ch);
1206 			/* Explain: inconsistent internal structures */
1207 		return;
1208 	}
1209 
1210 	/* Copy interruption response block. */
1211 	memcpy(ch->irb, irb, sizeof(struct irb));
1212 
1213 	/* Issue error message and return on subchannel error code */
1214 	if (irb->scsw.cmd.cstat) {
1215 		fsm_event(ch->fsm, CTC_EVENT_SC_UNKNOWN, ch);
1216 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
1217 			"%s(%s): sub-ch check %s: cs=%02x ds=%02x",
1218 				CTCM_FUNTAIL, dev->name, ch->id, cstat, dstat);
1219 		dev_warn(&cdev->dev,
1220 				"A check occurred on the subchannel\n");
1221 		return;
1222 	}
1223 
1224 	/* Check the reason-code of a unit check */
1225 	if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
1226 		if ((irb->ecw[0] & ch->sense_rc) == 0)
1227 			/* print it only once */
1228 			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
1229 				"%s(%s): sense=%02x, ds=%02x",
1230 				CTCM_FUNTAIL, ch->id, irb->ecw[0], dstat);
1231 		ccw_unit_check(ch, irb->ecw[0]);
1232 		return;
1233 	}
1234 	if (irb->scsw.cmd.dstat & DEV_STAT_BUSY) {
1235 		if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
1236 			fsm_event(ch->fsm, CTC_EVENT_ATTNBUSY, ch);
1237 		else
1238 			fsm_event(ch->fsm, CTC_EVENT_BUSY, ch);
1239 		return;
1240 	}
1241 	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
1242 		fsm_event(ch->fsm, CTC_EVENT_ATTN, ch);
1243 		return;
1244 	}
1245 	if ((irb->scsw.cmd.stctl & SCSW_STCTL_SEC_STATUS) ||
1246 	    (irb->scsw.cmd.stctl == SCSW_STCTL_STATUS_PEND) ||
1247 	    (irb->scsw.cmd.stctl ==
1248 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)))
1249 		fsm_event(ch->fsm, CTC_EVENT_FINSTAT, ch);
1250 	else
1251 		fsm_event(ch->fsm, CTC_EVENT_IRQ, ch);
1252 
1253 }
1254 
1255 static const struct device_type ctcm_devtype = {
1256 	.name = "ctcm",
1257 	.groups = ctcm_attr_groups,
1258 };
1259 
1260 /*
1261  * Add ctcm specific attributes.
1262  * Add ctcm private data.
1263  *
1264  *  cgdev	pointer to ccwgroup_device just added
1265  *
1266  * returns 0 on success, !0 on failure.
1267  */
1268 static int ctcm_probe_device(struct ccwgroup_device *cgdev)
1269 {
1270 	struct ctcm_priv *priv;
1271 
1272 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1273 			"%s %p",
1274 			__func__, cgdev);
1275 
1276 	if (!get_device(&cgdev->dev))
1277 		return -ENODEV;
1278 
1279 	priv = kzalloc(sizeof(struct ctcm_priv), GFP_KERNEL);
1280 	if (!priv) {
1281 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
1282 			"%s: memory allocation failure",
1283 			CTCM_FUNTAIL);
1284 		put_device(&cgdev->dev);
1285 		return -ENOMEM;
1286 	}
1287 	priv->buffer_size = CTCM_BUFSIZE_DEFAULT;
1288 	cgdev->cdev[0]->handler = ctcm_irq_handler;
1289 	cgdev->cdev[1]->handler = ctcm_irq_handler;
1290 	dev_set_drvdata(&cgdev->dev, priv);
1291 	cgdev->dev.type = &ctcm_devtype;
1292 
1293 	return 0;
1294 }
1295 
1296 /*
1297  * Add a new channel to the list of channels.
1298  * Keeps the channel list sorted.
1299  *
1300  *  cdev	The ccw_device to be added.
1301  *  type	The type class of the new channel.
1302  *  priv	Points to the private data of the ccwgroup_device.
1303  *
1304  * returns 0 on success, !0 on error.
1305  */
1306 static int add_channel(struct ccw_device *cdev, enum ctcm_channel_types type,
1307 				struct ctcm_priv *priv)
1308 {
1309 	struct channel **c = &channels;
1310 	struct channel *ch;
1311 	int ccw_num;
1312 	int rc = 0;
1313 
1314 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1315 		"%s(%s), type %d, proto %d",
1316 			__func__, dev_name(&cdev->dev),	type, priv->protocol);
1317 
1318 	ch = kzalloc(sizeof(struct channel), GFP_KERNEL);
1319 	if (ch == NULL)
1320 		return -ENOMEM;
1321 
1322 	ch->protocol = priv->protocol;
1323 	if (IS_MPC(priv)) {
1324 		ch->discontact_th = kzalloc(TH_HEADER_LENGTH, GFP_KERNEL);
1325 		if (ch->discontact_th == NULL)
1326 					goto nomem_return;
1327 
1328 		ch->discontact_th->th_blk_flag = TH_DISCONTACT;
1329 		tasklet_init(&ch->ch_disc_tasklet,
1330 			mpc_action_send_discontact, (unsigned long)ch);
1331 
1332 		tasklet_init(&ch->ch_tasklet, ctcmpc_bh, (unsigned long)ch);
1333 		ch->max_bufsize = (MPC_BUFSIZE_DEFAULT - 35);
1334 		ccw_num = 17;
1335 	} else
1336 		ccw_num = 8;
1337 
1338 	ch->ccw = kcalloc(ccw_num, sizeof(struct ccw1), GFP_KERNEL | GFP_DMA);
1339 	if (ch->ccw == NULL)
1340 					goto nomem_return;
1341 
1342 	ch->cdev = cdev;
1343 	snprintf(ch->id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev->dev));
1344 	ch->type = type;
1345 
1346 	/*
1347 	 * "static" ccws are used in the following way:
1348 	 *
1349 	 * ccw[0..2] (Channel program for generic I/O):
1350 	 *           0: prepare
1351 	 *           1: read or write (depending on direction) with fixed
1352 	 *              buffer (idal allocated once when buffer is allocated)
1353 	 *           2: nop
1354 	 * ccw[3..5] (Channel program for direct write of packets)
1355 	 *           3: prepare
1356 	 *           4: write (idal allocated on every write).
1357 	 *           5: nop
1358 	 * ccw[6..7] (Channel program for initial channel setup):
1359 	 *           6: set extended mode
1360 	 *           7: nop
1361 	 *
1362 	 * ch->ccw[0..5] are initialized in ch_action_start because
1363 	 * the channel's direction is yet unknown here.
1364 	 *
1365 	 * ccws used for xid2 negotiations
1366 	 *  ch-ccw[8-14] need to be used for the XID exchange either
1367 	 *    X side XID2 Processing
1368 	 *       8:  write control
1369 	 *       9:  write th
1370 	 *	     10: write XID
1371 	 *	     11: read th from secondary
1372 	 *	     12: read XID   from secondary
1373 	 *	     13: read 4 byte ID
1374 	 *	     14: nop
1375 	 *    Y side XID Processing
1376 	 *	     8:  sense
1377 	 *       9:  read th
1378 	 *	     10: read XID
1379 	 *	     11: write th
1380 	 *	     12: write XID
1381 	 *	     13: write 4 byte ID
1382 	 *	     14: nop
1383 	 *
1384 	 *  ccws used for double noop due to VM timing issues
1385 	 *  which result in unrecoverable Busy on channel
1386 	 *       15: nop
1387 	 *       16: nop
1388 	 */
1389 	ch->ccw[6].cmd_code	= CCW_CMD_SET_EXTENDED;
1390 	ch->ccw[6].flags	= CCW_FLAG_SLI;
1391 
1392 	ch->ccw[7].cmd_code	= CCW_CMD_NOOP;
1393 	ch->ccw[7].flags	= CCW_FLAG_SLI;
1394 
1395 	if (IS_MPC(priv)) {
1396 		ch->ccw[15].cmd_code = CCW_CMD_WRITE;
1397 		ch->ccw[15].flags    = CCW_FLAG_SLI | CCW_FLAG_CC;
1398 		ch->ccw[15].count    = TH_HEADER_LENGTH;
1399 		ch->ccw[15].cda      = virt_to_phys(ch->discontact_th);
1400 
1401 		ch->ccw[16].cmd_code = CCW_CMD_NOOP;
1402 		ch->ccw[16].flags    = CCW_FLAG_SLI;
1403 
1404 		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
1405 				ctc_ch_event_names, CTC_MPC_NR_STATES,
1406 				CTC_MPC_NR_EVENTS, ctcmpc_ch_fsm,
1407 				mpc_ch_fsm_len, GFP_KERNEL);
1408 	} else {
1409 		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
1410 				ctc_ch_event_names, CTC_NR_STATES,
1411 				CTC_NR_EVENTS, ch_fsm,
1412 				ch_fsm_len, GFP_KERNEL);
1413 	}
1414 	if (ch->fsm == NULL)
1415 				goto nomem_return;
1416 
1417 	fsm_newstate(ch->fsm, CTC_STATE_IDLE);
1418 
1419 	ch->irb = kzalloc(sizeof(struct irb), GFP_KERNEL);
1420 	if (ch->irb == NULL)
1421 				goto nomem_return;
1422 
1423 	while (*c && ctcm_less_than((*c)->id, ch->id))
1424 		c = &(*c)->next;
1425 
1426 	if (*c && (!strncmp((*c)->id, ch->id, CTCM_ID_SIZE))) {
1427 		CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1428 				"%s (%s) already in list, using old entry",
1429 				__func__, (*c)->id);
1430 
1431 				goto free_return;
1432 	}
1433 
1434 	spin_lock_init(&ch->collect_lock);
1435 
1436 	fsm_settimer(ch->fsm, &ch->timer);
1437 	skb_queue_head_init(&ch->io_queue);
1438 	skb_queue_head_init(&ch->collect_queue);
1439 
1440 	if (IS_MPC(priv)) {
1441 		fsm_settimer(ch->fsm, &ch->sweep_timer);
1442 		skb_queue_head_init(&ch->sweep_queue);
1443 	}
1444 	ch->next = *c;
1445 	*c = ch;
1446 	return 0;
1447 
1448 nomem_return:
1449 	rc = -ENOMEM;
1450 
1451 free_return:	/* note that all channel pointers are 0 or valid */
1452 	kfree(ch->ccw);
1453 	kfree(ch->discontact_th);
1454 	kfree_fsm(ch->fsm);
1455 	kfree(ch->irb);
1456 	kfree(ch);
1457 	return rc;
1458 }
1459 
1460 /*
1461  * Return type of a detected device.
1462  */
1463 static enum ctcm_channel_types get_channel_type(struct ccw_device_id *id)
1464 {
1465 	enum ctcm_channel_types type;
1466 	type = (enum ctcm_channel_types)id->driver_info;
1467 
1468 	if (type == ctcm_channel_type_ficon)
1469 		type = ctcm_channel_type_escon;
1470 
1471 	return type;
1472 }
1473 
1474 /*
1475  *
1476  * Setup an interface.
1477  *
1478  *  cgdev	Device to be setup.
1479  *
1480  * returns 0 on success, !0 on failure.
1481  */
1482 static int ctcm_new_device(struct ccwgroup_device *cgdev)
1483 {
1484 	char read_id[CTCM_ID_SIZE];
1485 	char write_id[CTCM_ID_SIZE];
1486 	int direction;
1487 	enum ctcm_channel_types type;
1488 	struct ctcm_priv *priv;
1489 	struct net_device *dev;
1490 	struct ccw_device *cdev0;
1491 	struct ccw_device *cdev1;
1492 	struct channel *readc;
1493 	struct channel *writec;
1494 	int ret;
1495 	int result;
1496 
1497 	priv = dev_get_drvdata(&cgdev->dev);
1498 	if (!priv) {
1499 		result = -ENODEV;
1500 		goto out_err_result;
1501 	}
1502 
1503 	cdev0 = cgdev->cdev[0];
1504 	cdev1 = cgdev->cdev[1];
1505 
1506 	type = get_channel_type(&cdev0->id);
1507 
1508 	snprintf(read_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev0->dev));
1509 	snprintf(write_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev1->dev));
1510 
1511 	ret = add_channel(cdev0, type, priv);
1512 	if (ret) {
1513 		result = ret;
1514 		goto out_err_result;
1515 	}
1516 	ret = add_channel(cdev1, type, priv);
1517 	if (ret) {
1518 		result = ret;
1519 		goto out_remove_channel1;
1520 	}
1521 
1522 	ret = ccw_device_set_online(cdev0);
1523 	if (ret != 0) {
1524 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
1525 			"%s(%s) set_online rc=%d",
1526 				CTCM_FUNTAIL, read_id, ret);
1527 		result = -EIO;
1528 		goto out_remove_channel2;
1529 	}
1530 
1531 	ret = ccw_device_set_online(cdev1);
1532 	if (ret != 0) {
1533 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
1534 			"%s(%s) set_online rc=%d",
1535 				CTCM_FUNTAIL, write_id, ret);
1536 
1537 		result = -EIO;
1538 		goto out_ccw1;
1539 	}
1540 
1541 	dev = ctcm_init_netdevice(priv);
1542 	if (dev == NULL) {
1543 		result = -ENODEV;
1544 		goto out_ccw2;
1545 	}
1546 
1547 	for (direction = CTCM_READ; direction <= CTCM_WRITE; direction++) {
1548 		priv->channel[direction] =
1549 			channel_get(type, direction == CTCM_READ ?
1550 				read_id : write_id, direction);
1551 		if (priv->channel[direction] == NULL) {
1552 			if (direction == CTCM_WRITE)
1553 				channel_free(priv->channel[CTCM_READ]);
1554 			result = -ENODEV;
1555 			goto out_dev;
1556 		}
1557 		priv->channel[direction]->netdev = dev;
1558 		priv->channel[direction]->protocol = priv->protocol;
1559 		priv->channel[direction]->max_bufsize = priv->buffer_size;
1560 	}
1561 	/* sysfs magic */
1562 	SET_NETDEV_DEV(dev, &cgdev->dev);
1563 
1564 	if (register_netdev(dev)) {
1565 		result = -ENODEV;
1566 		goto out_dev;
1567 	}
1568 
1569 	strlcpy(priv->fsm->name, dev->name, sizeof(priv->fsm->name));
1570 
1571 	dev_info(&dev->dev,
1572 		"setup OK : r/w = %s/%s, protocol : %d\n",
1573 			priv->channel[CTCM_READ]->id,
1574 			priv->channel[CTCM_WRITE]->id, priv->protocol);
1575 
1576 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1577 		"setup(%s) OK : r/w = %s/%s, protocol : %d", dev->name,
1578 			priv->channel[CTCM_READ]->id,
1579 			priv->channel[CTCM_WRITE]->id, priv->protocol);
1580 
1581 	return 0;
1582 out_dev:
1583 	ctcm_free_netdevice(dev);
1584 out_ccw2:
1585 	ccw_device_set_offline(cgdev->cdev[1]);
1586 out_ccw1:
1587 	ccw_device_set_offline(cgdev->cdev[0]);
1588 out_remove_channel2:
1589 	readc = channel_get(type, read_id, CTCM_READ);
1590 	channel_remove(readc);
1591 out_remove_channel1:
1592 	writec = channel_get(type, write_id, CTCM_WRITE);
1593 	channel_remove(writec);
1594 out_err_result:
1595 	return result;
1596 }
1597 
1598 /*
1599  * Shutdown an interface.
1600  *
1601  *  cgdev	Device to be shut down.
1602  *
1603  * returns 0 on success, !0 on failure.
1604  */
1605 static int ctcm_shutdown_device(struct ccwgroup_device *cgdev)
1606 {
1607 	struct ctcm_priv *priv;
1608 	struct net_device *dev;
1609 
1610 	priv = dev_get_drvdata(&cgdev->dev);
1611 	if (!priv)
1612 		return -ENODEV;
1613 
1614 	if (priv->channel[CTCM_READ]) {
1615 		dev = priv->channel[CTCM_READ]->netdev;
1616 		CTCM_DBF_DEV(SETUP, dev, "");
1617 		/* Close the device */
1618 		ctcm_close(dev);
1619 		dev->flags &= ~IFF_RUNNING;
1620 		channel_free(priv->channel[CTCM_READ]);
1621 	} else
1622 		dev = NULL;
1623 
1624 	if (priv->channel[CTCM_WRITE])
1625 		channel_free(priv->channel[CTCM_WRITE]);
1626 
1627 	if (dev) {
1628 		unregister_netdev(dev);
1629 		ctcm_free_netdevice(dev);
1630 	}
1631 
1632 	if (priv->fsm)
1633 		kfree_fsm(priv->fsm);
1634 
1635 	ccw_device_set_offline(cgdev->cdev[1]);
1636 	ccw_device_set_offline(cgdev->cdev[0]);
1637 	channel_remove(priv->channel[CTCM_READ]);
1638 	channel_remove(priv->channel[CTCM_WRITE]);
1639 	priv->channel[CTCM_READ] = priv->channel[CTCM_WRITE] = NULL;
1640 
1641 	return 0;
1642 
1643 }
1644 
1645 
1646 static void ctcm_remove_device(struct ccwgroup_device *cgdev)
1647 {
1648 	struct ctcm_priv *priv = dev_get_drvdata(&cgdev->dev);
1649 
1650 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1651 			"removing device %p, proto : %d",
1652 			cgdev, priv->protocol);
1653 
1654 	if (cgdev->state == CCWGROUP_ONLINE)
1655 		ctcm_shutdown_device(cgdev);
1656 	dev_set_drvdata(&cgdev->dev, NULL);
1657 	kfree(priv);
1658 	put_device(&cgdev->dev);
1659 }
1660 
1661 static struct ccw_device_id ctcm_ids[] = {
1662 	{CCW_DEVICE(0x3088, 0x08), .driver_info = ctcm_channel_type_parallel},
1663 	{CCW_DEVICE(0x3088, 0x1e), .driver_info = ctcm_channel_type_ficon},
1664 	{CCW_DEVICE(0x3088, 0x1f), .driver_info = ctcm_channel_type_escon},
1665 	{},
1666 };
1667 MODULE_DEVICE_TABLE(ccw, ctcm_ids);
1668 
1669 static struct ccw_driver ctcm_ccw_driver = {
1670 	.driver = {
1671 		.owner	= THIS_MODULE,
1672 		.name	= "ctcm",
1673 	},
1674 	.ids	= ctcm_ids,
1675 	.probe	= ccwgroup_probe_ccwdev,
1676 	.remove	= ccwgroup_remove_ccwdev,
1677 	.int_class = IRQIO_CTC,
1678 };
1679 
1680 static struct ccwgroup_driver ctcm_group_driver = {
1681 	.driver = {
1682 		.owner	= THIS_MODULE,
1683 		.name	= CTC_DRIVER_NAME,
1684 	},
1685 	.ccw_driver  = &ctcm_ccw_driver,
1686 	.setup	     = ctcm_probe_device,
1687 	.remove      = ctcm_remove_device,
1688 	.set_online  = ctcm_new_device,
1689 	.set_offline = ctcm_shutdown_device,
1690 };
1691 
1692 static ssize_t group_store(struct device_driver *ddrv, const char *buf,
1693 			   size_t count)
1694 {
1695 	int err;
1696 
1697 	err = ccwgroup_create_dev(ctcm_root_dev, &ctcm_group_driver, 2, buf);
1698 	return err ? err : count;
1699 }
1700 static DRIVER_ATTR_WO(group);
1701 
1702 static struct attribute *ctcm_drv_attrs[] = {
1703 	&driver_attr_group.attr,
1704 	NULL,
1705 };
1706 static struct attribute_group ctcm_drv_attr_group = {
1707 	.attrs = ctcm_drv_attrs,
1708 };
1709 static const struct attribute_group *ctcm_drv_attr_groups[] = {
1710 	&ctcm_drv_attr_group,
1711 	NULL,
1712 };
1713 
1714 /*
1715  * Module related routines
1716  */
1717 
1718 /*
1719  * Prepare to be unloaded. Free IRQ's and release all resources.
1720  * This is called just before this module is unloaded. It is
1721  * not called, if the usage count is !0, so we don't need to check
1722  * for that.
1723  */
1724 static void __exit ctcm_exit(void)
1725 {
1726 	ccwgroup_driver_unregister(&ctcm_group_driver);
1727 	ccw_driver_unregister(&ctcm_ccw_driver);
1728 	root_device_unregister(ctcm_root_dev);
1729 	ctcm_unregister_dbf_views();
1730 	pr_info("CTCM driver unloaded\n");
1731 }
1732 
1733 /*
1734  * Print Banner.
1735  */
1736 static void print_banner(void)
1737 {
1738 	pr_info("CTCM driver initialized\n");
1739 }
1740 
1741 /*
1742  * Initialize module.
1743  * This is called just after the module is loaded.
1744  *
1745  * returns 0 on success, !0 on error.
1746  */
1747 static int __init ctcm_init(void)
1748 {
1749 	int ret;
1750 
1751 	channels = NULL;
1752 
1753 	ret = ctcm_register_dbf_views();
1754 	if (ret)
1755 		goto out_err;
1756 	ctcm_root_dev = root_device_register("ctcm");
1757 	ret = PTR_ERR_OR_ZERO(ctcm_root_dev);
1758 	if (ret)
1759 		goto register_err;
1760 	ret = ccw_driver_register(&ctcm_ccw_driver);
1761 	if (ret)
1762 		goto ccw_err;
1763 	ctcm_group_driver.driver.groups = ctcm_drv_attr_groups;
1764 	ret = ccwgroup_driver_register(&ctcm_group_driver);
1765 	if (ret)
1766 		goto ccwgroup_err;
1767 	print_banner();
1768 	return 0;
1769 
1770 ccwgroup_err:
1771 	ccw_driver_unregister(&ctcm_ccw_driver);
1772 ccw_err:
1773 	root_device_unregister(ctcm_root_dev);
1774 register_err:
1775 	ctcm_unregister_dbf_views();
1776 out_err:
1777 	pr_err("%s / Initializing the ctcm device driver failed, ret = %d\n",
1778 		__func__, ret);
1779 	return ret;
1780 }
1781 
1782 module_init(ctcm_init);
1783 module_exit(ctcm_exit);
1784 
1785 MODULE_AUTHOR("Peter Tiedemann <ptiedem@de.ibm.com>");
1786 MODULE_DESCRIPTION("Network driver for S/390 CTC + CTCMPC (SNA)");
1787 MODULE_LICENSE("GPL");
1788 
1789