xref: /openbmc/linux/drivers/s390/net/ctcm_main.c (revision b627b4ed)
1 /*
2  * drivers/s390/net/ctcm_main.c
3  *
4  * Copyright IBM Corp. 2001, 2007
5  * Author(s):
6  *	Original CTC driver(s):
7  *		Fritz Elfert (felfert@millenux.com)
8  *		Dieter Wellerdiek (wel@de.ibm.com)
9  *		Martin Schwidefsky (schwidefsky@de.ibm.com)
10  *		Denis Joseph Barrow (barrow_dj@yahoo.com)
11  *		Jochen Roehrig (roehrig@de.ibm.com)
12  *		Cornelia Huck <cornelia.huck@de.ibm.com>
13  *	MPC additions:
14  *		Belinda Thompson (belindat@us.ibm.com)
15  *		Andy Richter (richtera@us.ibm.com)
16  *	Revived by:
17  *		Peter Tiedemann (ptiedem@de.ibm.com)
18  */
19 
20 #undef DEBUG
21 #undef DEBUGDATA
22 #undef DEBUGCCW
23 
24 #define KMSG_COMPONENT "ctcm"
25 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
26 
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/kernel.h>
30 #include <linux/slab.h>
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/interrupt.h>
34 #include <linux/timer.h>
35 #include <linux/bitops.h>
36 
37 #include <linux/signal.h>
38 #include <linux/string.h>
39 
40 #include <linux/ip.h>
41 #include <linux/if_arp.h>
42 #include <linux/tcp.h>
43 #include <linux/skbuff.h>
44 #include <linux/ctype.h>
45 #include <net/dst.h>
46 
47 #include <linux/io.h>
48 #include <asm/ccwdev.h>
49 #include <asm/ccwgroup.h>
50 #include <linux/uaccess.h>
51 
52 #include <asm/idals.h>
53 
54 #include "cu3088.h"
55 #include "ctcm_fsms.h"
56 #include "ctcm_main.h"
57 
58 /* Some common global variables */
59 
60 /*
61  * Linked list of all detected channels.
62  */
63 struct channel *channels;
64 
65 /**
66  * Unpack a just received skb and hand it over to
67  * upper layers.
68  *
69  *  ch		The channel where this skb has been received.
70  *  pskb	The received skb.
71  */
72 void ctcm_unpack_skb(struct channel *ch, struct sk_buff *pskb)
73 {
74 	struct net_device *dev = ch->netdev;
75 	struct ctcm_priv *priv = dev->ml_priv;
76 	__u16 len = *((__u16 *) pskb->data);
77 
78 	skb_put(pskb, 2 + LL_HEADER_LENGTH);
79 	skb_pull(pskb, 2);
80 	pskb->dev = dev;
81 	pskb->ip_summed = CHECKSUM_UNNECESSARY;
82 	while (len > 0) {
83 		struct sk_buff *skb;
84 		int skblen;
85 		struct ll_header *header = (struct ll_header *)pskb->data;
86 
87 		skb_pull(pskb, LL_HEADER_LENGTH);
88 		if ((ch->protocol == CTCM_PROTO_S390) &&
89 		    (header->type != ETH_P_IP)) {
90 			if (!(ch->logflags & LOG_FLAG_ILLEGALPKT)) {
91 				ch->logflags |= LOG_FLAG_ILLEGALPKT;
92 				/*
93 				 * Check packet type only if we stick strictly
94 				 * to S/390's protocol of OS390. This only
95 				 * supports IP. Otherwise allow any packet
96 				 * type.
97 				 */
98 				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
99 					"%s(%s): Illegal packet type 0x%04x"
100 					" - dropping",
101 					CTCM_FUNTAIL, dev->name, header->type);
102 			}
103 			priv->stats.rx_dropped++;
104 			priv->stats.rx_frame_errors++;
105 			return;
106 		}
107 		pskb->protocol = ntohs(header->type);
108 		if ((header->length <= LL_HEADER_LENGTH) ||
109 		    (len <= LL_HEADER_LENGTH)) {
110 			if (!(ch->logflags & LOG_FLAG_ILLEGALSIZE)) {
111 				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
112 					"%s(%s): Illegal packet size %d(%d,%d)"
113 					"- dropping",
114 					CTCM_FUNTAIL, dev->name,
115 					header->length, dev->mtu, len);
116 				ch->logflags |= LOG_FLAG_ILLEGALSIZE;
117 			}
118 
119 			priv->stats.rx_dropped++;
120 			priv->stats.rx_length_errors++;
121 			return;
122 		}
123 		header->length -= LL_HEADER_LENGTH;
124 		len -= LL_HEADER_LENGTH;
125 		if ((header->length > skb_tailroom(pskb)) ||
126 			(header->length > len)) {
127 			if (!(ch->logflags & LOG_FLAG_OVERRUN)) {
128 				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
129 					"%s(%s): Packet size %d (overrun)"
130 					" - dropping", CTCM_FUNTAIL,
131 						dev->name, header->length);
132 				ch->logflags |= LOG_FLAG_OVERRUN;
133 			}
134 
135 			priv->stats.rx_dropped++;
136 			priv->stats.rx_length_errors++;
137 			return;
138 		}
139 		skb_put(pskb, header->length);
140 		skb_reset_mac_header(pskb);
141 		len -= header->length;
142 		skb = dev_alloc_skb(pskb->len);
143 		if (!skb) {
144 			if (!(ch->logflags & LOG_FLAG_NOMEM)) {
145 				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
146 					"%s(%s): MEMORY allocation error",
147 						CTCM_FUNTAIL, dev->name);
148 				ch->logflags |= LOG_FLAG_NOMEM;
149 			}
150 			priv->stats.rx_dropped++;
151 			return;
152 		}
153 		skb_copy_from_linear_data(pskb, skb_put(skb, pskb->len),
154 					  pskb->len);
155 		skb_reset_mac_header(skb);
156 		skb->dev = pskb->dev;
157 		skb->protocol = pskb->protocol;
158 		pskb->ip_summed = CHECKSUM_UNNECESSARY;
159 		skblen = skb->len;
160 		/*
161 		 * reset logflags
162 		 */
163 		ch->logflags = 0;
164 		priv->stats.rx_packets++;
165 		priv->stats.rx_bytes += skblen;
166 		netif_rx_ni(skb);
167 		dev->last_rx = jiffies;
168 		if (len > 0) {
169 			skb_pull(pskb, header->length);
170 			if (skb_tailroom(pskb) < LL_HEADER_LENGTH) {
171 				CTCM_DBF_DEV_NAME(TRACE, dev,
172 					"Overrun in ctcm_unpack_skb");
173 				ch->logflags |= LOG_FLAG_OVERRUN;
174 				return;
175 			}
176 			skb_put(pskb, LL_HEADER_LENGTH);
177 		}
178 	}
179 }
180 
181 /**
182  * Release a specific channel in the channel list.
183  *
184  *  ch		Pointer to channel struct to be released.
185  */
186 static void channel_free(struct channel *ch)
187 {
188 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO, "%s(%s)", CTCM_FUNTAIL, ch->id);
189 	ch->flags &= ~CHANNEL_FLAGS_INUSE;
190 	fsm_newstate(ch->fsm, CTC_STATE_IDLE);
191 }
192 
193 /**
194  * Remove a specific channel in the channel list.
195  *
196  *  ch		Pointer to channel struct to be released.
197  */
198 static void channel_remove(struct channel *ch)
199 {
200 	struct channel **c = &channels;
201 	char chid[CTCM_ID_SIZE+1];
202 	int ok = 0;
203 
204 	if (ch == NULL)
205 		return;
206 	else
207 		strncpy(chid, ch->id, CTCM_ID_SIZE);
208 
209 	channel_free(ch);
210 	while (*c) {
211 		if (*c == ch) {
212 			*c = ch->next;
213 			fsm_deltimer(&ch->timer);
214 			if (IS_MPC(ch))
215 				fsm_deltimer(&ch->sweep_timer);
216 
217 			kfree_fsm(ch->fsm);
218 			clear_normalized_cda(&ch->ccw[4]);
219 			if (ch->trans_skb != NULL) {
220 				clear_normalized_cda(&ch->ccw[1]);
221 				dev_kfree_skb_any(ch->trans_skb);
222 			}
223 			if (IS_MPC(ch)) {
224 				tasklet_kill(&ch->ch_tasklet);
225 				tasklet_kill(&ch->ch_disc_tasklet);
226 				kfree(ch->discontact_th);
227 			}
228 			kfree(ch->ccw);
229 			kfree(ch->irb);
230 			kfree(ch);
231 			ok = 1;
232 			break;
233 		}
234 		c = &((*c)->next);
235 	}
236 
237 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO, "%s(%s) %s", CTCM_FUNTAIL,
238 			chid, ok ? "OK" : "failed");
239 }
240 
241 /**
242  * Get a specific channel from the channel list.
243  *
244  *  type	Type of channel we are interested in.
245  *  id		Id of channel we are interested in.
246  *  direction	Direction we want to use this channel for.
247  *
248  * returns Pointer to a channel or NULL if no matching channel available.
249  */
250 static struct channel *channel_get(enum channel_types type,
251 					char *id, int direction)
252 {
253 	struct channel *ch = channels;
254 
255 	while (ch && (strncmp(ch->id, id, CTCM_ID_SIZE) || (ch->type != type)))
256 		ch = ch->next;
257 	if (!ch) {
258 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
259 				"%s(%d, %s, %d) not found in channel list\n",
260 				CTCM_FUNTAIL, type, id, direction);
261 	} else {
262 		if (ch->flags & CHANNEL_FLAGS_INUSE)
263 			ch = NULL;
264 		else {
265 			ch->flags |= CHANNEL_FLAGS_INUSE;
266 			ch->flags &= ~CHANNEL_FLAGS_RWMASK;
267 			ch->flags |= (direction == WRITE)
268 			    ? CHANNEL_FLAGS_WRITE : CHANNEL_FLAGS_READ;
269 			fsm_newstate(ch->fsm, CTC_STATE_STOPPED);
270 		}
271 	}
272 	return ch;
273 }
274 
275 static long ctcm_check_irb_error(struct ccw_device *cdev, struct irb *irb)
276 {
277 	if (!IS_ERR(irb))
278 		return 0;
279 
280 	CTCM_DBF_TEXT_(ERROR, CTC_DBF_WARN,
281 			"irb error %ld on device %s\n",
282 				PTR_ERR(irb), dev_name(&cdev->dev));
283 
284 	switch (PTR_ERR(irb)) {
285 	case -EIO:
286 		dev_err(&cdev->dev,
287 			"An I/O-error occurred on the CTCM device\n");
288 		break;
289 	case -ETIMEDOUT:
290 		dev_err(&cdev->dev,
291 			"An adapter hardware operation timed out\n");
292 		break;
293 	default:
294 		dev_err(&cdev->dev,
295 			"An error occurred on the adapter hardware\n");
296 	}
297 	return PTR_ERR(irb);
298 }
299 
300 
301 /**
302  * Check sense of a unit check.
303  *
304  *  ch		The channel, the sense code belongs to.
305  *  sense	The sense code to inspect.
306  */
307 static inline void ccw_unit_check(struct channel *ch, __u8 sense)
308 {
309 	CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
310 			"%s(%s): %02x",
311 				CTCM_FUNTAIL, ch->id, sense);
312 
313 	if (sense & SNS0_INTERVENTION_REQ) {
314 		if (sense & 0x01) {
315 			if (ch->sense_rc != 0x01) {
316 				pr_notice(
317 					"%s: The communication peer has "
318 					"disconnected\n", ch->id);
319 				ch->sense_rc = 0x01;
320 			}
321 			fsm_event(ch->fsm, CTC_EVENT_UC_RCRESET, ch);
322 		} else {
323 			if (ch->sense_rc != SNS0_INTERVENTION_REQ) {
324 				pr_notice(
325 					"%s: The remote operating system is "
326 					"not available\n", ch->id);
327 				ch->sense_rc = SNS0_INTERVENTION_REQ;
328 			}
329 			fsm_event(ch->fsm, CTC_EVENT_UC_RSRESET, ch);
330 		}
331 	} else if (sense & SNS0_EQUIPMENT_CHECK) {
332 		if (sense & SNS0_BUS_OUT_CHECK) {
333 			if (ch->sense_rc != SNS0_BUS_OUT_CHECK) {
334 				CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
335 					"%s(%s): remote HW error %02x",
336 						CTCM_FUNTAIL, ch->id, sense);
337 				ch->sense_rc = SNS0_BUS_OUT_CHECK;
338 			}
339 			fsm_event(ch->fsm, CTC_EVENT_UC_HWFAIL, ch);
340 		} else {
341 			if (ch->sense_rc != SNS0_EQUIPMENT_CHECK) {
342 				CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
343 					"%s(%s): remote read parity error %02x",
344 						CTCM_FUNTAIL, ch->id, sense);
345 				ch->sense_rc = SNS0_EQUIPMENT_CHECK;
346 			}
347 			fsm_event(ch->fsm, CTC_EVENT_UC_RXPARITY, ch);
348 		}
349 	} else if (sense & SNS0_BUS_OUT_CHECK) {
350 		if (ch->sense_rc != SNS0_BUS_OUT_CHECK) {
351 			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
352 				"%s(%s): BUS OUT error %02x",
353 					CTCM_FUNTAIL, ch->id, sense);
354 			ch->sense_rc = SNS0_BUS_OUT_CHECK;
355 		}
356 		if (sense & 0x04)	/* data-streaming timeout */
357 			fsm_event(ch->fsm, CTC_EVENT_UC_TXTIMEOUT, ch);
358 		else			/* Data-transfer parity error */
359 			fsm_event(ch->fsm, CTC_EVENT_UC_TXPARITY, ch);
360 	} else if (sense & SNS0_CMD_REJECT) {
361 		if (ch->sense_rc != SNS0_CMD_REJECT) {
362 			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
363 				"%s(%s): Command rejected",
364 						CTCM_FUNTAIL, ch->id);
365 			ch->sense_rc = SNS0_CMD_REJECT;
366 		}
367 	} else if (sense == 0) {
368 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
369 			"%s(%s): Unit check ZERO",
370 					CTCM_FUNTAIL, ch->id);
371 		fsm_event(ch->fsm, CTC_EVENT_UC_ZERO, ch);
372 	} else {
373 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
374 			"%s(%s): Unit check code %02x unknown",
375 					CTCM_FUNTAIL, ch->id, sense);
376 		fsm_event(ch->fsm, CTC_EVENT_UC_UNKNOWN, ch);
377 	}
378 }
379 
380 int ctcm_ch_alloc_buffer(struct channel *ch)
381 {
382 	clear_normalized_cda(&ch->ccw[1]);
383 	ch->trans_skb = __dev_alloc_skb(ch->max_bufsize, GFP_ATOMIC | GFP_DMA);
384 	if (ch->trans_skb == NULL) {
385 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
386 			"%s(%s): %s trans_skb allocation error",
387 			CTCM_FUNTAIL, ch->id,
388 			(CHANNEL_DIRECTION(ch->flags) == READ) ? "RX" : "TX");
389 		return -ENOMEM;
390 	}
391 
392 	ch->ccw[1].count = ch->max_bufsize;
393 	if (set_normalized_cda(&ch->ccw[1], ch->trans_skb->data)) {
394 		dev_kfree_skb(ch->trans_skb);
395 		ch->trans_skb = NULL;
396 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
397 			"%s(%s): %s set norm_cda failed",
398 			CTCM_FUNTAIL, ch->id,
399 			(CHANNEL_DIRECTION(ch->flags) == READ) ? "RX" : "TX");
400 		return -ENOMEM;
401 	}
402 
403 	ch->ccw[1].count = 0;
404 	ch->trans_skb_data = ch->trans_skb->data;
405 	ch->flags &= ~CHANNEL_FLAGS_BUFSIZE_CHANGED;
406 	return 0;
407 }
408 
409 /*
410  * Interface API for upper network layers
411  */
412 
413 /**
414  * Open an interface.
415  * Called from generic network layer when ifconfig up is run.
416  *
417  *  dev		Pointer to interface struct.
418  *
419  * returns 0 on success, -ERRNO on failure. (Never fails.)
420  */
421 int ctcm_open(struct net_device *dev)
422 {
423 	struct ctcm_priv *priv = dev->ml_priv;
424 
425 	CTCMY_DBF_DEV_NAME(SETUP, dev, "");
426 	if (!IS_MPC(priv))
427 		fsm_event(priv->fsm,	DEV_EVENT_START, dev);
428 	return 0;
429 }
430 
431 /**
432  * Close an interface.
433  * Called from generic network layer when ifconfig down is run.
434  *
435  *  dev		Pointer to interface struct.
436  *
437  * returns 0 on success, -ERRNO on failure. (Never fails.)
438  */
439 int ctcm_close(struct net_device *dev)
440 {
441 	struct ctcm_priv *priv = dev->ml_priv;
442 
443 	CTCMY_DBF_DEV_NAME(SETUP, dev, "");
444 	if (!IS_MPC(priv))
445 		fsm_event(priv->fsm, DEV_EVENT_STOP, dev);
446 	return 0;
447 }
448 
449 
450 /**
451  * Transmit a packet.
452  * This is a helper function for ctcm_tx().
453  *
454  *  ch		Channel to be used for sending.
455  *  skb		Pointer to struct sk_buff of packet to send.
456  *            The linklevel header has already been set up
457  *            by ctcm_tx().
458  *
459  * returns 0 on success, -ERRNO on failure. (Never fails.)
460  */
461 static int ctcm_transmit_skb(struct channel *ch, struct sk_buff *skb)
462 {
463 	unsigned long saveflags;
464 	struct ll_header header;
465 	int rc = 0;
466 	__u16 block_len;
467 	int ccw_idx;
468 	struct sk_buff *nskb;
469 	unsigned long hi;
470 
471 	/* we need to acquire the lock for testing the state
472 	 * otherwise we can have an IRQ changing the state to
473 	 * TXIDLE after the test but before acquiring the lock.
474 	 */
475 	spin_lock_irqsave(&ch->collect_lock, saveflags);
476 	if (fsm_getstate(ch->fsm) != CTC_STATE_TXIDLE) {
477 		int l = skb->len + LL_HEADER_LENGTH;
478 
479 		if (ch->collect_len + l > ch->max_bufsize - 2) {
480 			spin_unlock_irqrestore(&ch->collect_lock, saveflags);
481 			return -EBUSY;
482 		} else {
483 			atomic_inc(&skb->users);
484 			header.length = l;
485 			header.type = skb->protocol;
486 			header.unused = 0;
487 			memcpy(skb_push(skb, LL_HEADER_LENGTH), &header,
488 			       LL_HEADER_LENGTH);
489 			skb_queue_tail(&ch->collect_queue, skb);
490 			ch->collect_len += l;
491 		}
492 		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
493 				goto done;
494 	}
495 	spin_unlock_irqrestore(&ch->collect_lock, saveflags);
496 	/*
497 	 * Protect skb against beeing free'd by upper
498 	 * layers.
499 	 */
500 	atomic_inc(&skb->users);
501 	ch->prof.txlen += skb->len;
502 	header.length = skb->len + LL_HEADER_LENGTH;
503 	header.type = skb->protocol;
504 	header.unused = 0;
505 	memcpy(skb_push(skb, LL_HEADER_LENGTH), &header, LL_HEADER_LENGTH);
506 	block_len = skb->len + 2;
507 	*((__u16 *)skb_push(skb, 2)) = block_len;
508 
509 	/*
510 	 * IDAL support in CTCM is broken, so we have to
511 	 * care about skb's above 2G ourselves.
512 	 */
513 	hi = ((unsigned long)skb_tail_pointer(skb) + LL_HEADER_LENGTH) >> 31;
514 	if (hi) {
515 		nskb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
516 		if (!nskb) {
517 			atomic_dec(&skb->users);
518 			skb_pull(skb, LL_HEADER_LENGTH + 2);
519 			ctcm_clear_busy(ch->netdev);
520 			return -ENOMEM;
521 		} else {
522 			memcpy(skb_put(nskb, skb->len), skb->data, skb->len);
523 			atomic_inc(&nskb->users);
524 			atomic_dec(&skb->users);
525 			dev_kfree_skb_irq(skb);
526 			skb = nskb;
527 		}
528 	}
529 
530 	ch->ccw[4].count = block_len;
531 	if (set_normalized_cda(&ch->ccw[4], skb->data)) {
532 		/*
533 		 * idal allocation failed, try via copying to
534 		 * trans_skb. trans_skb usually has a pre-allocated
535 		 * idal.
536 		 */
537 		if (ctcm_checkalloc_buffer(ch)) {
538 			/*
539 			 * Remove our header. It gets added
540 			 * again on retransmit.
541 			 */
542 			atomic_dec(&skb->users);
543 			skb_pull(skb, LL_HEADER_LENGTH + 2);
544 			ctcm_clear_busy(ch->netdev);
545 			return -ENOMEM;
546 		}
547 
548 		skb_reset_tail_pointer(ch->trans_skb);
549 		ch->trans_skb->len = 0;
550 		ch->ccw[1].count = skb->len;
551 		skb_copy_from_linear_data(skb,
552 				skb_put(ch->trans_skb, skb->len), skb->len);
553 		atomic_dec(&skb->users);
554 		dev_kfree_skb_irq(skb);
555 		ccw_idx = 0;
556 	} else {
557 		skb_queue_tail(&ch->io_queue, skb);
558 		ccw_idx = 3;
559 	}
560 	ch->retry = 0;
561 	fsm_newstate(ch->fsm, CTC_STATE_TX);
562 	fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
563 	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
564 	ch->prof.send_stamp = current_kernel_time(); /* xtime */
565 	rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx],
566 					(unsigned long)ch, 0xff, 0);
567 	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
568 	if (ccw_idx == 3)
569 		ch->prof.doios_single++;
570 	if (rc != 0) {
571 		fsm_deltimer(&ch->timer);
572 		ctcm_ccw_check_rc(ch, rc, "single skb TX");
573 		if (ccw_idx == 3)
574 			skb_dequeue_tail(&ch->io_queue);
575 		/*
576 		 * Remove our header. It gets added
577 		 * again on retransmit.
578 		 */
579 		skb_pull(skb, LL_HEADER_LENGTH + 2);
580 	} else if (ccw_idx == 0) {
581 		struct net_device *dev = ch->netdev;
582 		struct ctcm_priv *priv = dev->ml_priv;
583 		priv->stats.tx_packets++;
584 		priv->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
585 	}
586 done:
587 	ctcm_clear_busy(ch->netdev);
588 	return rc;
589 }
590 
591 static void ctcmpc_send_sweep_req(struct channel *rch)
592 {
593 	struct net_device *dev = rch->netdev;
594 	struct ctcm_priv *priv;
595 	struct mpc_group *grp;
596 	struct th_sweep *header;
597 	struct sk_buff *sweep_skb;
598 	struct channel *ch;
599 	/* int rc = 0; */
600 
601 	priv = dev->ml_priv;
602 	grp = priv->mpcg;
603 	ch = priv->channel[WRITE];
604 
605 	/* sweep processing is not complete until response and request */
606 	/* has completed for all read channels in group		       */
607 	if (grp->in_sweep == 0) {
608 		grp->in_sweep = 1;
609 		grp->sweep_rsp_pend_num = grp->active_channels[READ];
610 		grp->sweep_req_pend_num = grp->active_channels[READ];
611 	}
612 
613 	sweep_skb = __dev_alloc_skb(MPC_BUFSIZE_DEFAULT, GFP_ATOMIC|GFP_DMA);
614 
615 	if (sweep_skb == NULL)	{
616 		/* rc = -ENOMEM; */
617 				goto nomem;
618 	}
619 
620 	header = kmalloc(TH_SWEEP_LENGTH, gfp_type());
621 
622 	if (!header) {
623 		dev_kfree_skb_any(sweep_skb);
624 		/* rc = -ENOMEM; */
625 				goto nomem;
626 	}
627 
628 	header->th.th_seg	= 0x00 ;
629 	header->th.th_ch_flag	= TH_SWEEP_REQ;  /* 0x0f */
630 	header->th.th_blk_flag	= 0x00;
631 	header->th.th_is_xid	= 0x00;
632 	header->th.th_seq_num	= 0x00;
633 	header->sw.th_last_seq	= ch->th_seq_num;
634 
635 	memcpy(skb_put(sweep_skb, TH_SWEEP_LENGTH), header, TH_SWEEP_LENGTH);
636 
637 	kfree(header);
638 
639 	dev->trans_start = jiffies;
640 	skb_queue_tail(&ch->sweep_queue, sweep_skb);
641 
642 	fsm_addtimer(&ch->sweep_timer, 100, CTC_EVENT_RSWEEP_TIMER, ch);
643 
644 	return;
645 
646 nomem:
647 	grp->in_sweep = 0;
648 	ctcm_clear_busy(dev);
649 	fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
650 
651 	return;
652 }
653 
654 /*
655  * MPC mode version of transmit_skb
656  */
657 static int ctcmpc_transmit_skb(struct channel *ch, struct sk_buff *skb)
658 {
659 	struct pdu *p_header;
660 	struct net_device *dev = ch->netdev;
661 	struct ctcm_priv *priv = dev->ml_priv;
662 	struct mpc_group *grp = priv->mpcg;
663 	struct th_header *header;
664 	struct sk_buff *nskb;
665 	int rc = 0;
666 	int ccw_idx;
667 	unsigned long hi;
668 	unsigned long saveflags = 0;	/* avoids compiler warning */
669 	__u16 block_len;
670 
671 	CTCM_PR_DEBUG("Enter %s: %s, cp=%i ch=0x%p id=%s state=%s\n",
672 			__func__, dev->name, smp_processor_id(), ch,
673 					ch->id, fsm_getstate_str(ch->fsm));
674 
675 	if ((fsm_getstate(ch->fsm) != CTC_STATE_TXIDLE) || grp->in_sweep) {
676 		spin_lock_irqsave(&ch->collect_lock, saveflags);
677 		atomic_inc(&skb->users);
678 		p_header = kmalloc(PDU_HEADER_LENGTH, gfp_type());
679 
680 		if (!p_header) {
681 			spin_unlock_irqrestore(&ch->collect_lock, saveflags);
682 				goto nomem_exit;
683 		}
684 
685 		p_header->pdu_offset = skb->len;
686 		p_header->pdu_proto = 0x01;
687 		p_header->pdu_flag = 0x00;
688 		if (skb->protocol == ntohs(ETH_P_SNAP)) {
689 			p_header->pdu_flag |= PDU_FIRST | PDU_CNTL;
690 		} else {
691 			p_header->pdu_flag |= PDU_FIRST;
692 		}
693 		p_header->pdu_seq = 0;
694 		memcpy(skb_push(skb, PDU_HEADER_LENGTH), p_header,
695 		       PDU_HEADER_LENGTH);
696 
697 		CTCM_PR_DEBUG("%s(%s): Put on collect_q - skb len: %04x \n"
698 				"pdu header and data for up to 32 bytes:\n",
699 				__func__, dev->name, skb->len);
700 		CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
701 
702 		skb_queue_tail(&ch->collect_queue, skb);
703 		ch->collect_len += skb->len;
704 		kfree(p_header);
705 
706 		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
707 			goto done;
708 	}
709 
710 	/*
711 	 * Protect skb against beeing free'd by upper
712 	 * layers.
713 	 */
714 	atomic_inc(&skb->users);
715 
716 	block_len = skb->len + TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
717 	/*
718 	 * IDAL support in CTCM is broken, so we have to
719 	 * care about skb's above 2G ourselves.
720 	 */
721 	hi = ((unsigned long)skb->tail + TH_HEADER_LENGTH) >> 31;
722 	if (hi) {
723 		nskb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
724 		if (!nskb) {
725 			goto nomem_exit;
726 		} else {
727 			memcpy(skb_put(nskb, skb->len), skb->data, skb->len);
728 			atomic_inc(&nskb->users);
729 			atomic_dec(&skb->users);
730 			dev_kfree_skb_irq(skb);
731 			skb = nskb;
732 		}
733 	}
734 
735 	p_header = kmalloc(PDU_HEADER_LENGTH, gfp_type());
736 
737 	if (!p_header)
738 		goto nomem_exit;
739 
740 	p_header->pdu_offset = skb->len;
741 	p_header->pdu_proto = 0x01;
742 	p_header->pdu_flag = 0x00;
743 	p_header->pdu_seq = 0;
744 	if (skb->protocol == ntohs(ETH_P_SNAP)) {
745 		p_header->pdu_flag |= PDU_FIRST | PDU_CNTL;
746 	} else {
747 		p_header->pdu_flag |= PDU_FIRST;
748 	}
749 	memcpy(skb_push(skb, PDU_HEADER_LENGTH), p_header, PDU_HEADER_LENGTH);
750 
751 	kfree(p_header);
752 
753 	if (ch->collect_len > 0) {
754 		spin_lock_irqsave(&ch->collect_lock, saveflags);
755 		skb_queue_tail(&ch->collect_queue, skb);
756 		ch->collect_len += skb->len;
757 		skb = skb_dequeue(&ch->collect_queue);
758 		ch->collect_len -= skb->len;
759 		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
760 	}
761 
762 	p_header = (struct pdu *)skb->data;
763 	p_header->pdu_flag |= PDU_LAST;
764 
765 	ch->prof.txlen += skb->len - PDU_HEADER_LENGTH;
766 
767 	header = kmalloc(TH_HEADER_LENGTH, gfp_type());
768 	if (!header)
769 		goto nomem_exit;
770 
771 	header->th_seg = 0x00;
772 	header->th_ch_flag = TH_HAS_PDU;  /* Normal data */
773 	header->th_blk_flag = 0x00;
774 	header->th_is_xid = 0x00;          /* Just data here */
775 	ch->th_seq_num++;
776 	header->th_seq_num = ch->th_seq_num;
777 
778 	CTCM_PR_DBGDATA("%s(%s) ToVTAM_th_seq= %08x\n" ,
779 		       __func__, dev->name, ch->th_seq_num);
780 
781 	/* put the TH on the packet */
782 	memcpy(skb_push(skb, TH_HEADER_LENGTH), header, TH_HEADER_LENGTH);
783 
784 	kfree(header);
785 
786 	CTCM_PR_DBGDATA("%s(%s): skb len: %04x\n - pdu header and data for "
787 			"up to 32 bytes sent to vtam:\n",
788 				__func__, dev->name, skb->len);
789 	CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
790 
791 	ch->ccw[4].count = skb->len;
792 	if (set_normalized_cda(&ch->ccw[4], skb->data)) {
793 		/*
794 		 * idal allocation failed, try via copying to trans_skb.
795 		 * trans_skb usually has a pre-allocated idal.
796 		 */
797 		if (ctcm_checkalloc_buffer(ch)) {
798 			/*
799 			 * Remove our header.
800 			 * It gets added again on retransmit.
801 			 */
802 				goto nomem_exit;
803 		}
804 
805 		skb_reset_tail_pointer(ch->trans_skb);
806 		ch->trans_skb->len = 0;
807 		ch->ccw[1].count = skb->len;
808 		memcpy(skb_put(ch->trans_skb, skb->len), skb->data, skb->len);
809 		atomic_dec(&skb->users);
810 		dev_kfree_skb_irq(skb);
811 		ccw_idx = 0;
812 		CTCM_PR_DBGDATA("%s(%s): trans_skb len: %04x\n"
813 				"up to 32 bytes sent to vtam:\n",
814 				__func__, dev->name, ch->trans_skb->len);
815 		CTCM_D3_DUMP((char *)ch->trans_skb->data,
816 				min_t(int, 32, ch->trans_skb->len));
817 	} else {
818 		skb_queue_tail(&ch->io_queue, skb);
819 		ccw_idx = 3;
820 	}
821 	ch->retry = 0;
822 	fsm_newstate(ch->fsm, CTC_STATE_TX);
823 	fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
824 
825 	if (do_debug_ccw)
826 		ctcmpc_dumpit((char *)&ch->ccw[ccw_idx],
827 					sizeof(struct ccw1) * 3);
828 
829 	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
830 	ch->prof.send_stamp = current_kernel_time(); /* xtime */
831 	rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx],
832 					(unsigned long)ch, 0xff, 0);
833 	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
834 	if (ccw_idx == 3)
835 		ch->prof.doios_single++;
836 	if (rc != 0) {
837 		fsm_deltimer(&ch->timer);
838 		ctcm_ccw_check_rc(ch, rc, "single skb TX");
839 		if (ccw_idx == 3)
840 			skb_dequeue_tail(&ch->io_queue);
841 	} else if (ccw_idx == 0) {
842 		priv->stats.tx_packets++;
843 		priv->stats.tx_bytes += skb->len - TH_HEADER_LENGTH;
844 	}
845 	if (ch->th_seq_num > 0xf0000000)	/* Chose at random. */
846 		ctcmpc_send_sweep_req(ch);
847 
848 	goto done;
849 nomem_exit:
850 	CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_CRIT,
851 			"%s(%s): MEMORY allocation ERROR\n",
852 			CTCM_FUNTAIL, ch->id);
853 	rc = -ENOMEM;
854 	atomic_dec(&skb->users);
855 	dev_kfree_skb_any(skb);
856 	fsm_event(priv->mpcg->fsm, MPCG_EVENT_INOP, dev);
857 done:
858 	CTCM_PR_DEBUG("Exit %s(%s)\n", __func__, dev->name);
859 	return rc;
860 }
861 
862 /**
863  * Start transmission of a packet.
864  * Called from generic network device layer.
865  *
866  *  skb		Pointer to buffer containing the packet.
867  *  dev		Pointer to interface struct.
868  *
869  * returns 0 if packet consumed, !0 if packet rejected.
870  *         Note: If we return !0, then the packet is free'd by
871  *               the generic network layer.
872  */
873 /* first merge version - leaving both functions separated */
874 static int ctcm_tx(struct sk_buff *skb, struct net_device *dev)
875 {
876 	struct ctcm_priv *priv = dev->ml_priv;
877 
878 	if (skb == NULL) {
879 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
880 				"%s(%s): NULL sk_buff passed",
881 					CTCM_FUNTAIL, dev->name);
882 		priv->stats.tx_dropped++;
883 		return 0;
884 	}
885 	if (skb_headroom(skb) < (LL_HEADER_LENGTH + 2)) {
886 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
887 			"%s(%s): Got sk_buff with head room < %ld bytes",
888 			CTCM_FUNTAIL, dev->name, LL_HEADER_LENGTH + 2);
889 		dev_kfree_skb(skb);
890 		priv->stats.tx_dropped++;
891 		return 0;
892 	}
893 
894 	/*
895 	 * If channels are not running, try to restart them
896 	 * and throw away packet.
897 	 */
898 	if (fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) {
899 		fsm_event(priv->fsm, DEV_EVENT_START, dev);
900 		dev_kfree_skb(skb);
901 		priv->stats.tx_dropped++;
902 		priv->stats.tx_errors++;
903 		priv->stats.tx_carrier_errors++;
904 		return 0;
905 	}
906 
907 	if (ctcm_test_and_set_busy(dev))
908 		return NETDEV_TX_BUSY;
909 
910 	dev->trans_start = jiffies;
911 	if (ctcm_transmit_skb(priv->channel[WRITE], skb) != 0)
912 		return NETDEV_TX_BUSY;
913 	return 0;
914 }
915 
916 /* unmerged MPC variant of ctcm_tx */
917 static int ctcmpc_tx(struct sk_buff *skb, struct net_device *dev)
918 {
919 	int len = 0;
920 	struct ctcm_priv *priv = dev->ml_priv;
921 	struct mpc_group *grp  = priv->mpcg;
922 	struct sk_buff *newskb = NULL;
923 
924 	/*
925 	 * Some sanity checks ...
926 	 */
927 	if (skb == NULL) {
928 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
929 			"%s(%s): NULL sk_buff passed",
930 					CTCM_FUNTAIL, dev->name);
931 		priv->stats.tx_dropped++;
932 					goto done;
933 	}
934 	if (skb_headroom(skb) < (TH_HEADER_LENGTH + PDU_HEADER_LENGTH)) {
935 		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
936 			"%s(%s): Got sk_buff with head room < %ld bytes",
937 			CTCM_FUNTAIL, dev->name,
938 				TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
939 
940 		CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
941 
942 		len =  skb->len + TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
943 		newskb = __dev_alloc_skb(len, gfp_type() | GFP_DMA);
944 
945 		if (!newskb) {
946 			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
947 				"%s: %s: __dev_alloc_skb failed",
948 						__func__, dev->name);
949 
950 			dev_kfree_skb_any(skb);
951 			priv->stats.tx_dropped++;
952 			priv->stats.tx_errors++;
953 			priv->stats.tx_carrier_errors++;
954 			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
955 					goto done;
956 		}
957 		newskb->protocol = skb->protocol;
958 		skb_reserve(newskb, TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
959 		memcpy(skb_put(newskb, skb->len), skb->data, skb->len);
960 		dev_kfree_skb_any(skb);
961 		skb = newskb;
962 	}
963 
964 	/*
965 	 * If channels are not running,
966 	 * notify anybody about a link failure and throw
967 	 * away packet.
968 	 */
969 	if ((fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) ||
970 	   (fsm_getstate(grp->fsm) <  MPCG_STATE_XID2INITW)) {
971 		dev_kfree_skb_any(skb);
972 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
973 			"%s(%s): inactive MPCGROUP - dropped",
974 					CTCM_FUNTAIL, dev->name);
975 		priv->stats.tx_dropped++;
976 		priv->stats.tx_errors++;
977 		priv->stats.tx_carrier_errors++;
978 					goto done;
979 	}
980 
981 	if (ctcm_test_and_set_busy(dev)) {
982 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
983 			"%s(%s): device busy - dropped",
984 					CTCM_FUNTAIL, dev->name);
985 		dev_kfree_skb_any(skb);
986 		priv->stats.tx_dropped++;
987 		priv->stats.tx_errors++;
988 		priv->stats.tx_carrier_errors++;
989 		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
990 					goto done;
991 	}
992 
993 	dev->trans_start = jiffies;
994 	if (ctcmpc_transmit_skb(priv->channel[WRITE], skb) != 0) {
995 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
996 			"%s(%s): device error - dropped",
997 					CTCM_FUNTAIL, dev->name);
998 		dev_kfree_skb_any(skb);
999 		priv->stats.tx_dropped++;
1000 		priv->stats.tx_errors++;
1001 		priv->stats.tx_carrier_errors++;
1002 		ctcm_clear_busy(dev);
1003 		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
1004 					goto done;
1005 	}
1006 	ctcm_clear_busy(dev);
1007 done:
1008 	if (do_debug)
1009 		MPC_DBF_DEV_NAME(TRACE, dev, "exit");
1010 
1011 	return 0;	/* handle freeing of skb here */
1012 }
1013 
1014 
1015 /**
1016  * Sets MTU of an interface.
1017  *
1018  *  dev		Pointer to interface struct.
1019  *  new_mtu	The new MTU to use for this interface.
1020  *
1021  * returns 0 on success, -EINVAL if MTU is out of valid range.
1022  *         (valid range is 576 .. 65527). If VM is on the
1023  *         remote side, maximum MTU is 32760, however this is
1024  *         not checked here.
1025  */
1026 static int ctcm_change_mtu(struct net_device *dev, int new_mtu)
1027 {
1028 	struct ctcm_priv *priv;
1029 	int max_bufsize;
1030 
1031 	if (new_mtu < 576 || new_mtu > 65527)
1032 		return -EINVAL;
1033 
1034 	priv = dev->ml_priv;
1035 	max_bufsize = priv->channel[READ]->max_bufsize;
1036 
1037 	if (IS_MPC(priv)) {
1038 		if (new_mtu > max_bufsize - TH_HEADER_LENGTH)
1039 			return -EINVAL;
1040 		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
1041 	} else {
1042 		if (new_mtu > max_bufsize - LL_HEADER_LENGTH - 2)
1043 			return -EINVAL;
1044 		dev->hard_header_len = LL_HEADER_LENGTH + 2;
1045 	}
1046 	dev->mtu = new_mtu;
1047 	return 0;
1048 }
1049 
1050 /**
1051  * Returns interface statistics of a device.
1052  *
1053  *  dev		Pointer to interface struct.
1054  *
1055  * returns Pointer to stats struct of this interface.
1056  */
1057 static struct net_device_stats *ctcm_stats(struct net_device *dev)
1058 {
1059 	return &((struct ctcm_priv *)dev->ml_priv)->stats;
1060 }
1061 
1062 static void ctcm_free_netdevice(struct net_device *dev)
1063 {
1064 	struct ctcm_priv *priv;
1065 	struct mpc_group *grp;
1066 
1067 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1068 			"%s(%s)", CTCM_FUNTAIL, dev->name);
1069 	priv = dev->ml_priv;
1070 	if (priv) {
1071 		grp = priv->mpcg;
1072 		if (grp) {
1073 			if (grp->fsm)
1074 				kfree_fsm(grp->fsm);
1075 			if (grp->xid_skb)
1076 				dev_kfree_skb(grp->xid_skb);
1077 			if (grp->rcvd_xid_skb)
1078 				dev_kfree_skb(grp->rcvd_xid_skb);
1079 			tasklet_kill(&grp->mpc_tasklet2);
1080 			kfree(grp);
1081 			priv->mpcg = NULL;
1082 		}
1083 		if (priv->fsm) {
1084 			kfree_fsm(priv->fsm);
1085 			priv->fsm = NULL;
1086 		}
1087 		kfree(priv->xid);
1088 		priv->xid = NULL;
1089 	/*
1090 	 * Note: kfree(priv); is done in "opposite" function of
1091 	 * allocator function probe_device which is remove_device.
1092 	 */
1093 	}
1094 #ifdef MODULE
1095 	free_netdev(dev);
1096 #endif
1097 }
1098 
1099 struct mpc_group *ctcmpc_init_mpc_group(struct ctcm_priv *priv);
1100 
1101 static const struct net_device_ops ctcm_netdev_ops = {
1102 	.ndo_open		= ctcm_open,
1103 	.ndo_stop		= ctcm_close,
1104 	.ndo_get_stats		= ctcm_stats,
1105 	.ndo_change_mtu	   	= ctcm_change_mtu,
1106 	.ndo_start_xmit		= ctcm_tx,
1107 };
1108 
1109 static const struct net_device_ops ctcm_mpc_netdev_ops = {
1110 	.ndo_open		= ctcm_open,
1111 	.ndo_stop		= ctcm_close,
1112 	.ndo_get_stats		= ctcm_stats,
1113 	.ndo_change_mtu	   	= ctcm_change_mtu,
1114 	.ndo_start_xmit		= ctcmpc_tx,
1115 };
1116 
1117 void static ctcm_dev_setup(struct net_device *dev)
1118 {
1119 	dev->type = ARPHRD_SLIP;
1120 	dev->tx_queue_len = 100;
1121 	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1122 }
1123 
1124 /*
1125  * Initialize everything of the net device except the name and the
1126  * channel structs.
1127  */
1128 static struct net_device *ctcm_init_netdevice(struct ctcm_priv *priv)
1129 {
1130 	struct net_device *dev;
1131 	struct mpc_group *grp;
1132 	if (!priv)
1133 		return NULL;
1134 
1135 	if (IS_MPC(priv))
1136 		dev = alloc_netdev(0, MPC_DEVICE_GENE, ctcm_dev_setup);
1137 	else
1138 		dev = alloc_netdev(0, CTC_DEVICE_GENE, ctcm_dev_setup);
1139 
1140 	if (!dev) {
1141 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_CRIT,
1142 			"%s: MEMORY allocation ERROR",
1143 			CTCM_FUNTAIL);
1144 		return NULL;
1145 	}
1146 	dev->ml_priv = priv;
1147 	priv->fsm = init_fsm("ctcmdev", dev_state_names, dev_event_names,
1148 				CTCM_NR_DEV_STATES, CTCM_NR_DEV_EVENTS,
1149 				dev_fsm, dev_fsm_len, GFP_KERNEL);
1150 	if (priv->fsm == NULL) {
1151 		CTCMY_DBF_DEV(SETUP, dev, "init_fsm error");
1152 		kfree(dev);
1153 		return NULL;
1154 	}
1155 	fsm_newstate(priv->fsm, DEV_STATE_STOPPED);
1156 	fsm_settimer(priv->fsm, &priv->restart_timer);
1157 
1158 	if (IS_MPC(priv)) {
1159 		/*  MPC Group Initializations  */
1160 		grp = ctcmpc_init_mpc_group(priv);
1161 		if (grp == NULL) {
1162 			MPC_DBF_DEV(SETUP, dev, "init_mpc_group error");
1163 			kfree(dev);
1164 			return NULL;
1165 		}
1166 		tasklet_init(&grp->mpc_tasklet2,
1167 				mpc_group_ready, (unsigned long)dev);
1168 		dev->mtu = MPC_BUFSIZE_DEFAULT -
1169 				TH_HEADER_LENGTH - PDU_HEADER_LENGTH;
1170 
1171 		dev->netdev_ops = &ctcm_mpc_netdev_ops;
1172 		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
1173 		priv->buffer_size = MPC_BUFSIZE_DEFAULT;
1174 	} else {
1175 		dev->mtu = CTCM_BUFSIZE_DEFAULT - LL_HEADER_LENGTH - 2;
1176 		dev->netdev_ops = &ctcm_netdev_ops;
1177 		dev->hard_header_len = LL_HEADER_LENGTH + 2;
1178 	}
1179 
1180 	CTCMY_DBF_DEV(SETUP, dev, "finished");
1181 
1182 	return dev;
1183 }
1184 
1185 /**
1186  * Main IRQ handler.
1187  *
1188  *  cdev	The ccw_device the interrupt is for.
1189  *  intparm	interruption parameter.
1190  *  irb		interruption response block.
1191  */
1192 static void ctcm_irq_handler(struct ccw_device *cdev,
1193 				unsigned long intparm, struct irb *irb)
1194 {
1195 	struct channel		*ch;
1196 	struct net_device	*dev;
1197 	struct ctcm_priv	*priv;
1198 	struct ccwgroup_device	*cgdev;
1199 	int cstat;
1200 	int dstat;
1201 
1202 	CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
1203 		"Enter %s(%s)", CTCM_FUNTAIL, dev_name(&cdev->dev));
1204 
1205 	if (ctcm_check_irb_error(cdev, irb))
1206 		return;
1207 
1208 	cgdev = dev_get_drvdata(&cdev->dev);
1209 
1210 	cstat = irb->scsw.cmd.cstat;
1211 	dstat = irb->scsw.cmd.dstat;
1212 
1213 	/* Check for unsolicited interrupts. */
1214 	if (cgdev == NULL) {
1215 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_ERROR,
1216 			"%s(%s) unsolicited irq: c-%02x d-%02x\n",
1217 			CTCM_FUNTAIL, dev_name(&cdev->dev), cstat, dstat);
1218 		dev_warn(&cdev->dev,
1219 			"The adapter received a non-specific IRQ\n");
1220 		return;
1221 	}
1222 
1223 	priv = dev_get_drvdata(&cgdev->dev);
1224 
1225 	/* Try to extract channel from driver data. */
1226 	if (priv->channel[READ]->cdev == cdev)
1227 		ch = priv->channel[READ];
1228 	else if (priv->channel[WRITE]->cdev == cdev)
1229 		ch = priv->channel[WRITE];
1230 	else {
1231 		dev_err(&cdev->dev,
1232 			"%s: Internal error: Can't determine channel for "
1233 			"interrupt device %s\n",
1234 			__func__, dev_name(&cdev->dev));
1235 			/* Explain: inconsistent internal structures */
1236 		return;
1237 	}
1238 
1239 	dev = ch->netdev;
1240 	if (dev == NULL) {
1241 		dev_err(&cdev->dev,
1242 			"%s Internal error: net_device is NULL, ch = 0x%p\n",
1243 			__func__, ch);
1244 			/* Explain: inconsistent internal structures */
1245 		return;
1246 	}
1247 
1248 	/* Copy interruption response block. */
1249 	memcpy(ch->irb, irb, sizeof(struct irb));
1250 
1251 	/* Issue error message and return on subchannel error code */
1252 	if (irb->scsw.cmd.cstat) {
1253 		fsm_event(ch->fsm, CTC_EVENT_SC_UNKNOWN, ch);
1254 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
1255 			"%s(%s): sub-ch check %s: cs=%02x ds=%02x",
1256 				CTCM_FUNTAIL, dev->name, ch->id, cstat, dstat);
1257 		dev_warn(&cdev->dev,
1258 				"A check occurred on the subchannel\n");
1259 		return;
1260 	}
1261 
1262 	/* Check the reason-code of a unit check */
1263 	if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
1264 		if ((irb->ecw[0] & ch->sense_rc) == 0)
1265 			/* print it only once */
1266 			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
1267 				"%s(%s): sense=%02x, ds=%02x",
1268 				CTCM_FUNTAIL, ch->id, irb->ecw[0], dstat);
1269 		ccw_unit_check(ch, irb->ecw[0]);
1270 		return;
1271 	}
1272 	if (irb->scsw.cmd.dstat & DEV_STAT_BUSY) {
1273 		if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
1274 			fsm_event(ch->fsm, CTC_EVENT_ATTNBUSY, ch);
1275 		else
1276 			fsm_event(ch->fsm, CTC_EVENT_BUSY, ch);
1277 		return;
1278 	}
1279 	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
1280 		fsm_event(ch->fsm, CTC_EVENT_ATTN, ch);
1281 		return;
1282 	}
1283 	if ((irb->scsw.cmd.stctl & SCSW_STCTL_SEC_STATUS) ||
1284 	    (irb->scsw.cmd.stctl == SCSW_STCTL_STATUS_PEND) ||
1285 	    (irb->scsw.cmd.stctl ==
1286 	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)))
1287 		fsm_event(ch->fsm, CTC_EVENT_FINSTAT, ch);
1288 	else
1289 		fsm_event(ch->fsm, CTC_EVENT_IRQ, ch);
1290 
1291 }
1292 
1293 /**
1294  * Add ctcm specific attributes.
1295  * Add ctcm private data.
1296  *
1297  *  cgdev	pointer to ccwgroup_device just added
1298  *
1299  * returns 0 on success, !0 on failure.
1300  */
1301 static int ctcm_probe_device(struct ccwgroup_device *cgdev)
1302 {
1303 	struct ctcm_priv *priv;
1304 	int rc;
1305 
1306 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1307 			"%s %p",
1308 			__func__, cgdev);
1309 
1310 	if (!get_device(&cgdev->dev))
1311 		return -ENODEV;
1312 
1313 	priv = kzalloc(sizeof(struct ctcm_priv), GFP_KERNEL);
1314 	if (!priv) {
1315 		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
1316 			"%s: memory allocation failure",
1317 			CTCM_FUNTAIL);
1318 		put_device(&cgdev->dev);
1319 		return -ENOMEM;
1320 	}
1321 
1322 	rc = ctcm_add_files(&cgdev->dev);
1323 	if (rc) {
1324 		kfree(priv);
1325 		put_device(&cgdev->dev);
1326 		return rc;
1327 	}
1328 	priv->buffer_size = CTCM_BUFSIZE_DEFAULT;
1329 	cgdev->cdev[0]->handler = ctcm_irq_handler;
1330 	cgdev->cdev[1]->handler = ctcm_irq_handler;
1331 	dev_set_drvdata(&cgdev->dev, priv);
1332 
1333 	return 0;
1334 }
1335 
1336 /**
1337  * Add a new channel to the list of channels.
1338  * Keeps the channel list sorted.
1339  *
1340  *  cdev	The ccw_device to be added.
1341  *  type	The type class of the new channel.
1342  *  priv	Points to the private data of the ccwgroup_device.
1343  *
1344  * returns 0 on success, !0 on error.
1345  */
1346 static int add_channel(struct ccw_device *cdev, enum channel_types type,
1347 				struct ctcm_priv *priv)
1348 {
1349 	struct channel **c = &channels;
1350 	struct channel *ch;
1351 	int ccw_num;
1352 	int rc = 0;
1353 
1354 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1355 		"%s(%s), type %d, proto %d",
1356 			__func__, dev_name(&cdev->dev),	type, priv->protocol);
1357 
1358 	ch = kzalloc(sizeof(struct channel), GFP_KERNEL);
1359 	if (ch == NULL)
1360 		return -ENOMEM;
1361 
1362 	ch->protocol = priv->protocol;
1363 	if (IS_MPC(priv)) {
1364 		ch->discontact_th = (struct th_header *)
1365 				kzalloc(TH_HEADER_LENGTH, gfp_type());
1366 		if (ch->discontact_th == NULL)
1367 					goto nomem_return;
1368 
1369 		ch->discontact_th->th_blk_flag = TH_DISCONTACT;
1370 		tasklet_init(&ch->ch_disc_tasklet,
1371 			mpc_action_send_discontact, (unsigned long)ch);
1372 
1373 		tasklet_init(&ch->ch_tasklet, ctcmpc_bh, (unsigned long)ch);
1374 		ch->max_bufsize = (MPC_BUFSIZE_DEFAULT - 35);
1375 		ccw_num = 17;
1376 	} else
1377 		ccw_num = 8;
1378 
1379 	ch->ccw = (struct ccw1 *)
1380 		kzalloc(ccw_num * sizeof(struct ccw1), GFP_KERNEL | GFP_DMA);
1381 	if (ch->ccw == NULL)
1382 					goto nomem_return;
1383 
1384 	ch->cdev = cdev;
1385 	snprintf(ch->id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev->dev));
1386 	ch->type = type;
1387 
1388 	/**
1389 	 * "static" ccws are used in the following way:
1390 	 *
1391 	 * ccw[0..2] (Channel program for generic I/O):
1392 	 *           0: prepare
1393 	 *           1: read or write (depending on direction) with fixed
1394 	 *              buffer (idal allocated once when buffer is allocated)
1395 	 *           2: nop
1396 	 * ccw[3..5] (Channel program for direct write of packets)
1397 	 *           3: prepare
1398 	 *           4: write (idal allocated on every write).
1399 	 *           5: nop
1400 	 * ccw[6..7] (Channel program for initial channel setup):
1401 	 *           6: set extended mode
1402 	 *           7: nop
1403 	 *
1404 	 * ch->ccw[0..5] are initialized in ch_action_start because
1405 	 * the channel's direction is yet unknown here.
1406 	 *
1407 	 * ccws used for xid2 negotiations
1408 	 *  ch-ccw[8-14] need to be used for the XID exchange either
1409 	 *    X side XID2 Processing
1410 	 *       8:  write control
1411 	 *       9:  write th
1412 	 *	     10: write XID
1413 	 *	     11: read th from secondary
1414 	 *	     12: read XID   from secondary
1415 	 *	     13: read 4 byte ID
1416 	 *	     14: nop
1417 	 *    Y side XID Processing
1418 	 *	     8:  sense
1419 	 *       9:  read th
1420 	 *	     10: read XID
1421 	 *	     11: write th
1422 	 *	     12: write XID
1423 	 *	     13: write 4 byte ID
1424 	 *	     14: nop
1425 	 *
1426 	 *  ccws used for double noop due to VM timing issues
1427 	 *  which result in unrecoverable Busy on channel
1428 	 *       15: nop
1429 	 *       16: nop
1430 	 */
1431 	ch->ccw[6].cmd_code	= CCW_CMD_SET_EXTENDED;
1432 	ch->ccw[6].flags	= CCW_FLAG_SLI;
1433 
1434 	ch->ccw[7].cmd_code	= CCW_CMD_NOOP;
1435 	ch->ccw[7].flags	= CCW_FLAG_SLI;
1436 
1437 	if (IS_MPC(priv)) {
1438 		ch->ccw[15].cmd_code = CCW_CMD_WRITE;
1439 		ch->ccw[15].flags    = CCW_FLAG_SLI | CCW_FLAG_CC;
1440 		ch->ccw[15].count    = TH_HEADER_LENGTH;
1441 		ch->ccw[15].cda      = virt_to_phys(ch->discontact_th);
1442 
1443 		ch->ccw[16].cmd_code = CCW_CMD_NOOP;
1444 		ch->ccw[16].flags    = CCW_FLAG_SLI;
1445 
1446 		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
1447 				ctc_ch_event_names, CTC_MPC_NR_STATES,
1448 				CTC_MPC_NR_EVENTS, ctcmpc_ch_fsm,
1449 				mpc_ch_fsm_len, GFP_KERNEL);
1450 	} else {
1451 		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
1452 				ctc_ch_event_names, CTC_NR_STATES,
1453 				CTC_NR_EVENTS, ch_fsm,
1454 				ch_fsm_len, GFP_KERNEL);
1455 	}
1456 	if (ch->fsm == NULL)
1457 				goto free_return;
1458 
1459 	fsm_newstate(ch->fsm, CTC_STATE_IDLE);
1460 
1461 	ch->irb = kzalloc(sizeof(struct irb), GFP_KERNEL);
1462 	if (ch->irb == NULL)
1463 				goto nomem_return;
1464 
1465 	while (*c && ctcm_less_than((*c)->id, ch->id))
1466 		c = &(*c)->next;
1467 
1468 	if (*c && (!strncmp((*c)->id, ch->id, CTCM_ID_SIZE))) {
1469 		CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1470 				"%s (%s) already in list, using old entry",
1471 				__func__, (*c)->id);
1472 
1473 				goto free_return;
1474 	}
1475 
1476 	spin_lock_init(&ch->collect_lock);
1477 
1478 	fsm_settimer(ch->fsm, &ch->timer);
1479 	skb_queue_head_init(&ch->io_queue);
1480 	skb_queue_head_init(&ch->collect_queue);
1481 
1482 	if (IS_MPC(priv)) {
1483 		fsm_settimer(ch->fsm, &ch->sweep_timer);
1484 		skb_queue_head_init(&ch->sweep_queue);
1485 	}
1486 	ch->next = *c;
1487 	*c = ch;
1488 	return 0;
1489 
1490 nomem_return:
1491 	rc = -ENOMEM;
1492 
1493 free_return:	/* note that all channel pointers are 0 or valid */
1494 	kfree(ch->ccw);
1495 	kfree(ch->discontact_th);
1496 	kfree_fsm(ch->fsm);
1497 	kfree(ch->irb);
1498 	kfree(ch);
1499 	return rc;
1500 }
1501 
1502 /*
1503  * Return type of a detected device.
1504  */
1505 static enum channel_types get_channel_type(struct ccw_device_id *id)
1506 {
1507 	enum channel_types type;
1508 	type = (enum channel_types)id->driver_info;
1509 
1510 	if (type == channel_type_ficon)
1511 		type = channel_type_escon;
1512 
1513 	return type;
1514 }
1515 
1516 /**
1517  *
1518  * Setup an interface.
1519  *
1520  *  cgdev	Device to be setup.
1521  *
1522  * returns 0 on success, !0 on failure.
1523  */
1524 static int ctcm_new_device(struct ccwgroup_device *cgdev)
1525 {
1526 	char read_id[CTCM_ID_SIZE];
1527 	char write_id[CTCM_ID_SIZE];
1528 	int direction;
1529 	enum channel_types type;
1530 	struct ctcm_priv *priv;
1531 	struct net_device *dev;
1532 	struct ccw_device *cdev0;
1533 	struct ccw_device *cdev1;
1534 	int ret;
1535 
1536 	priv = dev_get_drvdata(&cgdev->dev);
1537 	if (!priv)
1538 		return -ENODEV;
1539 
1540 	cdev0 = cgdev->cdev[0];
1541 	cdev1 = cgdev->cdev[1];
1542 
1543 	type = get_channel_type(&cdev0->id);
1544 
1545 	snprintf(read_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev0->dev));
1546 	snprintf(write_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev1->dev));
1547 
1548 	ret = add_channel(cdev0, type, priv);
1549 	if (ret)
1550 		return ret;
1551 	ret = add_channel(cdev1, type, priv);
1552 	if (ret)
1553 		return ret;
1554 
1555 	ret = ccw_device_set_online(cdev0);
1556 	if (ret != 0) {
1557 		/* may be ok to fail now - can be done later */
1558 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
1559 			"%s(%s) set_online rc=%d",
1560 				CTCM_FUNTAIL, read_id, ret);
1561 	}
1562 
1563 	ret = ccw_device_set_online(cdev1);
1564 	if (ret != 0) {
1565 		/* may be ok to fail now - can be done later */
1566 		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
1567 			"%s(%s) set_online rc=%d",
1568 				CTCM_FUNTAIL, write_id, ret);
1569 	}
1570 
1571 	dev = ctcm_init_netdevice(priv);
1572 	if (dev == NULL)
1573 			goto out;
1574 
1575 	for (direction = READ; direction <= WRITE; direction++) {
1576 		priv->channel[direction] =
1577 		    channel_get(type, direction == READ ? read_id : write_id,
1578 				direction);
1579 		if (priv->channel[direction] == NULL) {
1580 			if (direction == WRITE)
1581 				channel_free(priv->channel[READ]);
1582 			goto out_dev;
1583 		}
1584 		priv->channel[direction]->netdev = dev;
1585 		priv->channel[direction]->protocol = priv->protocol;
1586 		priv->channel[direction]->max_bufsize = priv->buffer_size;
1587 	}
1588 	/* sysfs magic */
1589 	SET_NETDEV_DEV(dev, &cgdev->dev);
1590 
1591 	if (register_netdev(dev))
1592 			goto out_dev;
1593 
1594 	if (ctcm_add_attributes(&cgdev->dev)) {
1595 		unregister_netdev(dev);
1596 			goto out_dev;
1597 	}
1598 
1599 	strlcpy(priv->fsm->name, dev->name, sizeof(priv->fsm->name));
1600 
1601 	dev_info(&dev->dev,
1602 		"setup OK : r/w = %s/%s, protocol : %d\n",
1603 			priv->channel[READ]->id,
1604 			priv->channel[WRITE]->id, priv->protocol);
1605 
1606 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1607 		"setup(%s) OK : r/w = %s/%s, protocol : %d", dev->name,
1608 			priv->channel[READ]->id,
1609 			priv->channel[WRITE]->id, priv->protocol);
1610 
1611 	return 0;
1612 out_dev:
1613 	ctcm_free_netdevice(dev);
1614 out:
1615 	ccw_device_set_offline(cgdev->cdev[1]);
1616 	ccw_device_set_offline(cgdev->cdev[0]);
1617 
1618 	return -ENODEV;
1619 }
1620 
1621 /**
1622  * Shutdown an interface.
1623  *
1624  *  cgdev	Device to be shut down.
1625  *
1626  * returns 0 on success, !0 on failure.
1627  */
1628 static int ctcm_shutdown_device(struct ccwgroup_device *cgdev)
1629 {
1630 	struct ctcm_priv *priv;
1631 	struct net_device *dev;
1632 
1633 	priv = dev_get_drvdata(&cgdev->dev);
1634 	if (!priv)
1635 		return -ENODEV;
1636 
1637 	if (priv->channel[READ]) {
1638 		dev = priv->channel[READ]->netdev;
1639 		CTCM_DBF_DEV(SETUP, dev, "");
1640 		/* Close the device */
1641 		ctcm_close(dev);
1642 		dev->flags &= ~IFF_RUNNING;
1643 		ctcm_remove_attributes(&cgdev->dev);
1644 		channel_free(priv->channel[READ]);
1645 	} else
1646 		dev = NULL;
1647 
1648 	if (priv->channel[WRITE])
1649 		channel_free(priv->channel[WRITE]);
1650 
1651 	if (dev) {
1652 		unregister_netdev(dev);
1653 		ctcm_free_netdevice(dev);
1654 	}
1655 
1656 	if (priv->fsm)
1657 		kfree_fsm(priv->fsm);
1658 
1659 	ccw_device_set_offline(cgdev->cdev[1]);
1660 	ccw_device_set_offline(cgdev->cdev[0]);
1661 
1662 	if (priv->channel[READ])
1663 		channel_remove(priv->channel[READ]);
1664 	if (priv->channel[WRITE])
1665 		channel_remove(priv->channel[WRITE]);
1666 	priv->channel[READ] = priv->channel[WRITE] = NULL;
1667 
1668 	return 0;
1669 
1670 }
1671 
1672 
1673 static void ctcm_remove_device(struct ccwgroup_device *cgdev)
1674 {
1675 	struct ctcm_priv *priv = dev_get_drvdata(&cgdev->dev);
1676 
1677 	BUG_ON(priv == NULL);
1678 
1679 	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1680 			"removing device %s, r/w = %s/%s, proto : %d",
1681 			priv->channel[READ]->netdev->name,
1682 			priv->channel[READ]->id, priv->channel[WRITE]->id,
1683 			priv->protocol);
1684 
1685 	if (cgdev->state == CCWGROUP_ONLINE)
1686 		ctcm_shutdown_device(cgdev);
1687 	ctcm_remove_files(&cgdev->dev);
1688 	dev_set_drvdata(&cgdev->dev, NULL);
1689 	kfree(priv);
1690 	put_device(&cgdev->dev);
1691 }
1692 
1693 static struct ccwgroup_driver ctcm_group_driver = {
1694 	.owner       = THIS_MODULE,
1695 	.name        = CTC_DRIVER_NAME,
1696 	.max_slaves  = 2,
1697 	.driver_id   = 0xC3E3C3D4,	/* CTCM */
1698 	.probe       = ctcm_probe_device,
1699 	.remove      = ctcm_remove_device,
1700 	.set_online  = ctcm_new_device,
1701 	.set_offline = ctcm_shutdown_device,
1702 };
1703 
1704 
1705 /*
1706  * Module related routines
1707  */
1708 
1709 /*
1710  * Prepare to be unloaded. Free IRQ's and release all resources.
1711  * This is called just before this module is unloaded. It is
1712  * not called, if the usage count is !0, so we don't need to check
1713  * for that.
1714  */
1715 static void __exit ctcm_exit(void)
1716 {
1717 	unregister_cu3088_discipline(&ctcm_group_driver);
1718 	ctcm_unregister_dbf_views();
1719 	pr_info("CTCM driver unloaded\n");
1720 }
1721 
1722 /*
1723  * Print Banner.
1724  */
1725 static void print_banner(void)
1726 {
1727 	pr_info("CTCM driver initialized\n");
1728 }
1729 
1730 /**
1731  * Initialize module.
1732  * This is called just after the module is loaded.
1733  *
1734  * returns 0 on success, !0 on error.
1735  */
1736 static int __init ctcm_init(void)
1737 {
1738 	int ret;
1739 
1740 	channels = NULL;
1741 
1742 	ret = ctcm_register_dbf_views();
1743 	if (ret) {
1744 		return ret;
1745 	}
1746 	ret = register_cu3088_discipline(&ctcm_group_driver);
1747 	if (ret) {
1748 		ctcm_unregister_dbf_views();
1749 		pr_err("%s / register_cu3088_discipline failed, ret = %d\n",
1750 			__func__, ret);
1751 		return ret;
1752 	}
1753 	print_banner();
1754 	return ret;
1755 }
1756 
1757 module_init(ctcm_init);
1758 module_exit(ctcm_exit);
1759 
1760 MODULE_AUTHOR("Peter Tiedemann <ptiedem@de.ibm.com>");
1761 MODULE_DESCRIPTION("Network driver for S/390 CTC + CTCMPC (SNA)");
1762 MODULE_LICENSE("GPL");
1763 
1764