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 */
61static struct device *ctcm_root_dev;
62
63/*
64 * Linked list of all detected channels.
65 */
66struct 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 */
75void 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_ni(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 */
188static 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 */
200static 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 */
252static 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
277static 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 */
309static 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
382int 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 */
425int 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 */
443int 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 */
465static 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	}
592done:
593	ctcm_clear_busy(ch->netdev);
594	return rc;
595}
596
597static 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 = kmalloc(TH_SWEEP_LENGTH, gfp_type());
627
628	if (!header) {
629		dev_kfree_skb_any(sweep_skb);
630		/* rc = -ENOMEM; */
631				goto nomem;
632	}
633
634	header->th.th_seg	= 0x00 ;
635	header->th.th_ch_flag	= TH_SWEEP_REQ;  /* 0x0f */
636	header->th.th_blk_flag	= 0x00;
637	header->th.th_is_xid	= 0x00;
638	header->th.th_seq_num	= 0x00;
639	header->sw.th_last_seq	= ch->th_seq_num;
640
641	skb_put_data(sweep_skb, header, TH_SWEEP_LENGTH);
642
643	kfree(header);
644
645	netif_trans_update(dev);
646	skb_queue_tail(&ch->sweep_queue, sweep_skb);
647
648	fsm_addtimer(&ch->sweep_timer, 100, CTC_EVENT_RSWEEP_TIMER, ch);
649
650	return;
651
652nomem:
653	grp->in_sweep = 0;
654	ctcm_clear_busy(dev);
655	fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
656
657	return;
658}
659
660/*
661 * MPC mode version of transmit_skb
662 */
663static int ctcmpc_transmit_skb(struct channel *ch, struct sk_buff *skb)
664{
665	struct pdu *p_header;
666	struct net_device *dev = ch->netdev;
667	struct ctcm_priv *priv = dev->ml_priv;
668	struct mpc_group *grp = priv->mpcg;
669	struct th_header *header;
670	struct sk_buff *nskb;
671	int rc = 0;
672	int ccw_idx;
673	unsigned long hi;
674	unsigned long saveflags = 0;	/* avoids compiler warning */
675
676	CTCM_PR_DEBUG("Enter %s: %s, cp=%i ch=0x%p id=%s state=%s\n",
677			__func__, dev->name, smp_processor_id(), ch,
678					ch->id, fsm_getstate_str(ch->fsm));
679
680	if ((fsm_getstate(ch->fsm) != CTC_STATE_TXIDLE) || grp->in_sweep) {
681		spin_lock_irqsave(&ch->collect_lock, saveflags);
682		refcount_inc(&skb->users);
683		p_header = kmalloc(PDU_HEADER_LENGTH, gfp_type());
684
685		if (!p_header) {
686			spin_unlock_irqrestore(&ch->collect_lock, saveflags);
687				goto nomem_exit;
688		}
689
690		p_header->pdu_offset = skb->len;
691		p_header->pdu_proto = 0x01;
692		p_header->pdu_flag = 0x00;
693		if (be16_to_cpu(skb->protocol) == ETH_P_SNAP) {
694			p_header->pdu_flag |= PDU_FIRST | PDU_CNTL;
695		} else {
696			p_header->pdu_flag |= PDU_FIRST;
697		}
698		p_header->pdu_seq = 0;
699		memcpy(skb_push(skb, PDU_HEADER_LENGTH), p_header,
700		       PDU_HEADER_LENGTH);
701
702		CTCM_PR_DEBUG("%s(%s): Put on collect_q - skb len: %04x \n"
703				"pdu header and data for up to 32 bytes:\n",
704				__func__, dev->name, skb->len);
705		CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
706
707		skb_queue_tail(&ch->collect_queue, skb);
708		ch->collect_len += skb->len;
709		kfree(p_header);
710
711		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
712			goto done;
713	}
714
715	/*
716	 * Protect skb against beeing free'd by upper
717	 * layers.
718	 */
719	refcount_inc(&skb->users);
720
721	/*
722	 * IDAL support in CTCM is broken, so we have to
723	 * care about skb's above 2G ourselves.
724	 */
725	hi = ((unsigned long)skb->tail + TH_HEADER_LENGTH) >> 31;
726	if (hi) {
727		nskb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
728		if (!nskb) {
729			goto nomem_exit;
730		} else {
731			skb_put_data(nskb, skb->data, skb->len);
732			refcount_inc(&nskb->users);
733			refcount_dec(&skb->users);
734			dev_kfree_skb_irq(skb);
735			skb = nskb;
736		}
737	}
738
739	p_header = kmalloc(PDU_HEADER_LENGTH, gfp_type());
740
741	if (!p_header)
742		goto nomem_exit;
743
744	p_header->pdu_offset = skb->len;
745	p_header->pdu_proto = 0x01;
746	p_header->pdu_flag = 0x00;
747	p_header->pdu_seq = 0;
748	if (be16_to_cpu(skb->protocol) == ETH_P_SNAP) {
749		p_header->pdu_flag |= PDU_FIRST | PDU_CNTL;
750	} else {
751		p_header->pdu_flag |= PDU_FIRST;
752	}
753	memcpy(skb_push(skb, PDU_HEADER_LENGTH), p_header, PDU_HEADER_LENGTH);
754
755	kfree(p_header);
756
757	if (ch->collect_len > 0) {
758		spin_lock_irqsave(&ch->collect_lock, saveflags);
759		skb_queue_tail(&ch->collect_queue, skb);
760		ch->collect_len += skb->len;
761		skb = skb_dequeue(&ch->collect_queue);
762		ch->collect_len -= skb->len;
763		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
764	}
765
766	p_header = (struct pdu *)skb->data;
767	p_header->pdu_flag |= PDU_LAST;
768
769	ch->prof.txlen += skb->len - PDU_HEADER_LENGTH;
770
771	header = kmalloc(TH_HEADER_LENGTH, gfp_type());
772	if (!header)
773		goto nomem_exit;
774
775	header->th_seg = 0x00;
776	header->th_ch_flag = TH_HAS_PDU;  /* Normal data */
777	header->th_blk_flag = 0x00;
778	header->th_is_xid = 0x00;          /* Just data here */
779	ch->th_seq_num++;
780	header->th_seq_num = ch->th_seq_num;
781
782	CTCM_PR_DBGDATA("%s(%s) ToVTAM_th_seq= %08x\n" ,
783		       __func__, dev->name, ch->th_seq_num);
784
785	/* put the TH on the packet */
786	memcpy(skb_push(skb, TH_HEADER_LENGTH), header, TH_HEADER_LENGTH);
787
788	kfree(header);
789
790	CTCM_PR_DBGDATA("%s(%s): skb len: %04x\n - pdu header and data for "
791			"up to 32 bytes sent to vtam:\n",
792				__func__, dev->name, skb->len);
793	CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
794
795	ch->ccw[4].count = skb->len;
796	if (set_normalized_cda(&ch->ccw[4], skb->data)) {
797		/*
798		 * idal allocation failed, try via copying to trans_skb.
799		 * trans_skb usually has a pre-allocated idal.
800		 */
801		if (ctcm_checkalloc_buffer(ch)) {
802			/*
803			 * Remove our header.
804			 * It gets added again on retransmit.
805			 */
806				goto nomem_exit;
807		}
808
809		skb_reset_tail_pointer(ch->trans_skb);
810		ch->trans_skb->len = 0;
811		ch->ccw[1].count = skb->len;
812		skb_put_data(ch->trans_skb, skb->data, skb->len);
813		refcount_dec(&skb->users);
814		dev_kfree_skb_irq(skb);
815		ccw_idx = 0;
816		CTCM_PR_DBGDATA("%s(%s): trans_skb len: %04x\n"
817				"up to 32 bytes sent to vtam:\n",
818				__func__, dev->name, ch->trans_skb->len);
819		CTCM_D3_DUMP((char *)ch->trans_skb->data,
820				min_t(int, 32, ch->trans_skb->len));
821	} else {
822		skb_queue_tail(&ch->io_queue, skb);
823		ccw_idx = 3;
824	}
825	ch->retry = 0;
826	fsm_newstate(ch->fsm, CTC_STATE_TX);
827	fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
828
829	if (do_debug_ccw)
830		ctcmpc_dumpit((char *)&ch->ccw[ccw_idx],
831					sizeof(struct ccw1) * 3);
832
833	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
834	ch->prof.send_stamp = jiffies;
835	rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx], 0, 0xff, 0);
836	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
837	if (ccw_idx == 3)
838		ch->prof.doios_single++;
839	if (rc != 0) {
840		fsm_deltimer(&ch->timer);
841		ctcm_ccw_check_rc(ch, rc, "single skb TX");
842		if (ccw_idx == 3)
843			skb_dequeue_tail(&ch->io_queue);
844	} else if (ccw_idx == 0) {
845		priv->stats.tx_packets++;
846		priv->stats.tx_bytes += skb->len - TH_HEADER_LENGTH;
847	}
848	if (ch->th_seq_num > 0xf0000000)	/* Chose at random. */
849		ctcmpc_send_sweep_req(ch);
850
851	goto done;
852nomem_exit:
853	CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_CRIT,
854			"%s(%s): MEMORY allocation ERROR\n",
855			CTCM_FUNTAIL, ch->id);
856	rc = -ENOMEM;
857	refcount_dec(&skb->users);
858	dev_kfree_skb_any(skb);
859	fsm_event(priv->mpcg->fsm, MPCG_EVENT_INOP, dev);
860done:
861	CTCM_PR_DEBUG("Exit %s(%s)\n", __func__, dev->name);
862	return rc;
863}
864
865/**
866 * Start transmission of a packet.
867 * Called from generic network device layer.
868 */
869/* first merge version - leaving both functions separated */
870static netdev_tx_t ctcm_tx(struct sk_buff *skb, struct net_device *dev)
871{
872	struct ctcm_priv *priv = dev->ml_priv;
873
874	if (skb == NULL) {
875		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
876				"%s(%s): NULL sk_buff passed",
877					CTCM_FUNTAIL, dev->name);
878		priv->stats.tx_dropped++;
879		return NETDEV_TX_OK;
880	}
881	if (skb_headroom(skb) < (LL_HEADER_LENGTH + 2)) {
882		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
883			"%s(%s): Got sk_buff with head room < %ld bytes",
884			CTCM_FUNTAIL, dev->name, LL_HEADER_LENGTH + 2);
885		dev_kfree_skb(skb);
886		priv->stats.tx_dropped++;
887		return NETDEV_TX_OK;
888	}
889
890	/*
891	 * If channels are not running, try to restart them
892	 * and throw away packet.
893	 */
894	if (fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) {
895		fsm_event(priv->fsm, DEV_EVENT_START, dev);
896		dev_kfree_skb(skb);
897		priv->stats.tx_dropped++;
898		priv->stats.tx_errors++;
899		priv->stats.tx_carrier_errors++;
900		return NETDEV_TX_OK;
901	}
902
903	if (ctcm_test_and_set_busy(dev))
904		return NETDEV_TX_BUSY;
905
906	netif_trans_update(dev);
907	if (ctcm_transmit_skb(priv->channel[CTCM_WRITE], skb) != 0)
908		return NETDEV_TX_BUSY;
909	return NETDEV_TX_OK;
910}
911
912/* unmerged MPC variant of ctcm_tx */
913static netdev_tx_t ctcmpc_tx(struct sk_buff *skb, struct net_device *dev)
914{
915	int len = 0;
916	struct ctcm_priv *priv = dev->ml_priv;
917	struct mpc_group *grp  = priv->mpcg;
918	struct sk_buff *newskb = NULL;
919
920	/*
921	 * Some sanity checks ...
922	 */
923	if (skb == NULL) {
924		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
925			"%s(%s): NULL sk_buff passed",
926					CTCM_FUNTAIL, dev->name);
927		priv->stats.tx_dropped++;
928					goto done;
929	}
930	if (skb_headroom(skb) < (TH_HEADER_LENGTH + PDU_HEADER_LENGTH)) {
931		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
932			"%s(%s): Got sk_buff with head room < %ld bytes",
933			CTCM_FUNTAIL, dev->name,
934				TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
935
936		CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
937
938		len =  skb->len + TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
939		newskb = __dev_alloc_skb(len, gfp_type() | GFP_DMA);
940
941		if (!newskb) {
942			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
943				"%s: %s: __dev_alloc_skb failed",
944						__func__, dev->name);
945
946			dev_kfree_skb_any(skb);
947			priv->stats.tx_dropped++;
948			priv->stats.tx_errors++;
949			priv->stats.tx_carrier_errors++;
950			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
951					goto done;
952		}
953		newskb->protocol = skb->protocol;
954		skb_reserve(newskb, TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
955		skb_put_data(newskb, skb->data, skb->len);
956		dev_kfree_skb_any(skb);
957		skb = newskb;
958	}
959
960	/*
961	 * If channels are not running,
962	 * notify anybody about a link failure and throw
963	 * away packet.
964	 */
965	if ((fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) ||
966	   (fsm_getstate(grp->fsm) <  MPCG_STATE_XID2INITW)) {
967		dev_kfree_skb_any(skb);
968		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
969			"%s(%s): inactive MPCGROUP - dropped",
970					CTCM_FUNTAIL, dev->name);
971		priv->stats.tx_dropped++;
972		priv->stats.tx_errors++;
973		priv->stats.tx_carrier_errors++;
974					goto done;
975	}
976
977	if (ctcm_test_and_set_busy(dev)) {
978		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
979			"%s(%s): device busy - dropped",
980					CTCM_FUNTAIL, dev->name);
981		dev_kfree_skb_any(skb);
982		priv->stats.tx_dropped++;
983		priv->stats.tx_errors++;
984		priv->stats.tx_carrier_errors++;
985		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
986					goto done;
987	}
988
989	netif_trans_update(dev);
990	if (ctcmpc_transmit_skb(priv->channel[CTCM_WRITE], skb) != 0) {
991		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
992			"%s(%s): device error - dropped",
993					CTCM_FUNTAIL, dev->name);
994		dev_kfree_skb_any(skb);
995		priv->stats.tx_dropped++;
996		priv->stats.tx_errors++;
997		priv->stats.tx_carrier_errors++;
998		ctcm_clear_busy(dev);
999		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
1000					goto done;
1001	}
1002	ctcm_clear_busy(dev);
1003done:
1004	if (do_debug)
1005		MPC_DBF_DEV_NAME(TRACE, dev, "exit");
1006
1007	return NETDEV_TX_OK;	/* handle freeing of skb here */
1008}
1009
1010
1011/**
1012 * Sets MTU of an interface.
1013 *
1014 *  dev		Pointer to interface struct.
1015 *  new_mtu	The new MTU to use for this interface.
1016 *
1017 * returns 0 on success, -EINVAL if MTU is out of valid range.
1018 *         (valid range is 576 .. 65527). If VM is on the
1019 *         remote side, maximum MTU is 32760, however this is
1020 *         not checked here.
1021 */
1022static int ctcm_change_mtu(struct net_device *dev, int new_mtu)
1023{
1024	struct ctcm_priv *priv;
1025	int max_bufsize;
1026
1027	priv = dev->ml_priv;
1028	max_bufsize = priv->channel[CTCM_READ]->max_bufsize;
1029
1030	if (IS_MPC(priv)) {
1031		if (new_mtu > max_bufsize - TH_HEADER_LENGTH)
1032			return -EINVAL;
1033		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
1034	} else {
1035		if (new_mtu > max_bufsize - LL_HEADER_LENGTH - 2)
1036			return -EINVAL;
1037		dev->hard_header_len = LL_HEADER_LENGTH + 2;
1038	}
1039	dev->mtu = new_mtu;
1040	return 0;
1041}
1042
1043/**
1044 * Returns interface statistics of a device.
1045 *
1046 *  dev		Pointer to interface struct.
1047 *
1048 * returns Pointer to stats struct of this interface.
1049 */
1050static struct net_device_stats *ctcm_stats(struct net_device *dev)
1051{
1052	return &((struct ctcm_priv *)dev->ml_priv)->stats;
1053}
1054
1055static void ctcm_free_netdevice(struct net_device *dev)
1056{
1057	struct ctcm_priv *priv;
1058	struct mpc_group *grp;
1059
1060	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1061			"%s(%s)", CTCM_FUNTAIL, dev->name);
1062	priv = dev->ml_priv;
1063	if (priv) {
1064		grp = priv->mpcg;
1065		if (grp) {
1066			if (grp->fsm)
1067				kfree_fsm(grp->fsm);
1068			dev_kfree_skb(grp->xid_skb);
1069			dev_kfree_skb(grp->rcvd_xid_skb);
1070			tasklet_kill(&grp->mpc_tasklet2);
1071			kfree(grp);
1072			priv->mpcg = NULL;
1073		}
1074		if (priv->fsm) {
1075			kfree_fsm(priv->fsm);
1076			priv->fsm = NULL;
1077		}
1078		kfree(priv->xid);
1079		priv->xid = NULL;
1080	/*
1081	 * Note: kfree(priv); is done in "opposite" function of
1082	 * allocator function probe_device which is remove_device.
1083	 */
1084	}
1085#ifdef MODULE
1086	free_netdev(dev);
1087#endif
1088}
1089
1090struct mpc_group *ctcmpc_init_mpc_group(struct ctcm_priv *priv);
1091
1092static const struct net_device_ops ctcm_netdev_ops = {
1093	.ndo_open		= ctcm_open,
1094	.ndo_stop		= ctcm_close,
1095	.ndo_get_stats		= ctcm_stats,
1096	.ndo_change_mtu	   	= ctcm_change_mtu,
1097	.ndo_start_xmit		= ctcm_tx,
1098};
1099
1100static const struct net_device_ops ctcm_mpc_netdev_ops = {
1101	.ndo_open		= ctcm_open,
1102	.ndo_stop		= ctcm_close,
1103	.ndo_get_stats		= ctcm_stats,
1104	.ndo_change_mtu	   	= ctcm_change_mtu,
1105	.ndo_start_xmit		= ctcmpc_tx,
1106};
1107
1108static void ctcm_dev_setup(struct net_device *dev)
1109{
1110	dev->type = ARPHRD_SLIP;
1111	dev->tx_queue_len = 100;
1112	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1113	dev->min_mtu = 576;
1114	dev->max_mtu = 65527;
1115}
1116
1117/*
1118 * Initialize everything of the net device except the name and the
1119 * channel structs.
1120 */
1121static struct net_device *ctcm_init_netdevice(struct ctcm_priv *priv)
1122{
1123	struct net_device *dev;
1124	struct mpc_group *grp;
1125	if (!priv)
1126		return NULL;
1127
1128	if (IS_MPC(priv))
1129		dev = alloc_netdev(0, MPC_DEVICE_GENE, NET_NAME_UNKNOWN,
1130				   ctcm_dev_setup);
1131	else
1132		dev = alloc_netdev(0, CTC_DEVICE_GENE, NET_NAME_UNKNOWN,
1133				   ctcm_dev_setup);
1134
1135	if (!dev) {
1136		CTCM_DBF_TEXT_(ERROR, CTC_DBF_CRIT,
1137			"%s: MEMORY allocation ERROR",
1138			CTCM_FUNTAIL);
1139		return NULL;
1140	}
1141	dev->ml_priv = priv;
1142	priv->fsm = init_fsm("ctcmdev", dev_state_names, dev_event_names,
1143				CTCM_NR_DEV_STATES, CTCM_NR_DEV_EVENTS,
1144				dev_fsm, dev_fsm_len, GFP_KERNEL);
1145	if (priv->fsm == NULL) {
1146		CTCMY_DBF_DEV(SETUP, dev, "init_fsm error");
1147		free_netdev(dev);
1148		return NULL;
1149	}
1150	fsm_newstate(priv->fsm, DEV_STATE_STOPPED);
1151	fsm_settimer(priv->fsm, &priv->restart_timer);
1152
1153	if (IS_MPC(priv)) {
1154		/*  MPC Group Initializations  */
1155		grp = ctcmpc_init_mpc_group(priv);
1156		if (grp == NULL) {
1157			MPC_DBF_DEV(SETUP, dev, "init_mpc_group error");
1158			free_netdev(dev);
1159			return NULL;
1160		}
1161		tasklet_init(&grp->mpc_tasklet2,
1162				mpc_group_ready, (unsigned long)dev);
1163		dev->mtu = MPC_BUFSIZE_DEFAULT -
1164				TH_HEADER_LENGTH - PDU_HEADER_LENGTH;
1165
1166		dev->netdev_ops = &ctcm_mpc_netdev_ops;
1167		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
1168		priv->buffer_size = MPC_BUFSIZE_DEFAULT;
1169	} else {
1170		dev->mtu = CTCM_BUFSIZE_DEFAULT - LL_HEADER_LENGTH - 2;
1171		dev->netdev_ops = &ctcm_netdev_ops;
1172		dev->hard_header_len = LL_HEADER_LENGTH + 2;
1173	}
1174
1175	CTCMY_DBF_DEV(SETUP, dev, "finished");
1176
1177	return dev;
1178}
1179
1180/**
1181 * Main IRQ handler.
1182 *
1183 *  cdev	The ccw_device the interrupt is for.
1184 *  intparm	interruption parameter.
1185 *  irb		interruption response block.
1186 */
1187static void ctcm_irq_handler(struct ccw_device *cdev,
1188				unsigned long intparm, struct irb *irb)
1189{
1190	struct channel		*ch;
1191	struct net_device	*dev;
1192	struct ctcm_priv	*priv;
1193	struct ccwgroup_device	*cgdev;
1194	int cstat;
1195	int dstat;
1196
1197	CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
1198		"Enter %s(%s)", CTCM_FUNTAIL, dev_name(&cdev->dev));
1199
1200	if (ctcm_check_irb_error(cdev, irb))
1201		return;
1202
1203	cgdev = dev_get_drvdata(&cdev->dev);
1204
1205	cstat = irb->scsw.cmd.cstat;
1206	dstat = irb->scsw.cmd.dstat;
1207
1208	/* Check for unsolicited interrupts. */
1209	if (cgdev == NULL) {
1210		CTCM_DBF_TEXT_(TRACE, CTC_DBF_ERROR,
1211			"%s(%s) unsolicited irq: c-%02x d-%02x\n",
1212			CTCM_FUNTAIL, dev_name(&cdev->dev), cstat, dstat);
1213		dev_warn(&cdev->dev,
1214			"The adapter received a non-specific IRQ\n");
1215		return;
1216	}
1217
1218	priv = dev_get_drvdata(&cgdev->dev);
1219
1220	/* Try to extract channel from driver data. */
1221	if (priv->channel[CTCM_READ]->cdev == cdev)
1222		ch = priv->channel[CTCM_READ];
1223	else if (priv->channel[CTCM_WRITE]->cdev == cdev)
1224		ch = priv->channel[CTCM_WRITE];
1225	else {
1226		dev_err(&cdev->dev,
1227			"%s: Internal error: Can't determine channel for "
1228			"interrupt device %s\n",
1229			__func__, dev_name(&cdev->dev));
1230			/* Explain: inconsistent internal structures */
1231		return;
1232	}
1233
1234	dev = ch->netdev;
1235	if (dev == NULL) {
1236		dev_err(&cdev->dev,
1237			"%s Internal error: net_device is NULL, ch = 0x%p\n",
1238			__func__, ch);
1239			/* Explain: inconsistent internal structures */
1240		return;
1241	}
1242
1243	/* Copy interruption response block. */
1244	memcpy(ch->irb, irb, sizeof(struct irb));
1245
1246	/* Issue error message and return on subchannel error code */
1247	if (irb->scsw.cmd.cstat) {
1248		fsm_event(ch->fsm, CTC_EVENT_SC_UNKNOWN, ch);
1249		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
1250			"%s(%s): sub-ch check %s: cs=%02x ds=%02x",
1251				CTCM_FUNTAIL, dev->name, ch->id, cstat, dstat);
1252		dev_warn(&cdev->dev,
1253				"A check occurred on the subchannel\n");
1254		return;
1255	}
1256
1257	/* Check the reason-code of a unit check */
1258	if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
1259		if ((irb->ecw[0] & ch->sense_rc) == 0)
1260			/* print it only once */
1261			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
1262				"%s(%s): sense=%02x, ds=%02x",
1263				CTCM_FUNTAIL, ch->id, irb->ecw[0], dstat);
1264		ccw_unit_check(ch, irb->ecw[0]);
1265		return;
1266	}
1267	if (irb->scsw.cmd.dstat & DEV_STAT_BUSY) {
1268		if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
1269			fsm_event(ch->fsm, CTC_EVENT_ATTNBUSY, ch);
1270		else
1271			fsm_event(ch->fsm, CTC_EVENT_BUSY, ch);
1272		return;
1273	}
1274	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
1275		fsm_event(ch->fsm, CTC_EVENT_ATTN, ch);
1276		return;
1277	}
1278	if ((irb->scsw.cmd.stctl & SCSW_STCTL_SEC_STATUS) ||
1279	    (irb->scsw.cmd.stctl == SCSW_STCTL_STATUS_PEND) ||
1280	    (irb->scsw.cmd.stctl ==
1281	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)))
1282		fsm_event(ch->fsm, CTC_EVENT_FINSTAT, ch);
1283	else
1284		fsm_event(ch->fsm, CTC_EVENT_IRQ, ch);
1285
1286}
1287
1288static const struct device_type ctcm_devtype = {
1289	.name = "ctcm",
1290	.groups = ctcm_attr_groups,
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 */
1301static int ctcm_probe_device(struct ccwgroup_device *cgdev)
1302{
1303	struct ctcm_priv *priv;
1304
1305	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1306			"%s %p",
1307			__func__, cgdev);
1308
1309	if (!get_device(&cgdev->dev))
1310		return -ENODEV;
1311
1312	priv = kzalloc(sizeof(struct ctcm_priv), GFP_KERNEL);
1313	if (!priv) {
1314		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
1315			"%s: memory allocation failure",
1316			CTCM_FUNTAIL);
1317		put_device(&cgdev->dev);
1318		return -ENOMEM;
1319	}
1320	priv->buffer_size = CTCM_BUFSIZE_DEFAULT;
1321	cgdev->cdev[0]->handler = ctcm_irq_handler;
1322	cgdev->cdev[1]->handler = ctcm_irq_handler;
1323	dev_set_drvdata(&cgdev->dev, priv);
1324	cgdev->dev.type = &ctcm_devtype;
1325
1326	return 0;
1327}
1328
1329/**
1330 * Add a new channel to the list of channels.
1331 * Keeps the channel list sorted.
1332 *
1333 *  cdev	The ccw_device to be added.
1334 *  type	The type class of the new channel.
1335 *  priv	Points to the private data of the ccwgroup_device.
1336 *
1337 * returns 0 on success, !0 on error.
1338 */
1339static int add_channel(struct ccw_device *cdev, enum ctcm_channel_types type,
1340				struct ctcm_priv *priv)
1341{
1342	struct channel **c = &channels;
1343	struct channel *ch;
1344	int ccw_num;
1345	int rc = 0;
1346
1347	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1348		"%s(%s), type %d, proto %d",
1349			__func__, dev_name(&cdev->dev),	type, priv->protocol);
1350
1351	ch = kzalloc(sizeof(struct channel), GFP_KERNEL);
1352	if (ch == NULL)
1353		return -ENOMEM;
1354
1355	ch->protocol = priv->protocol;
1356	if (IS_MPC(priv)) {
1357		ch->discontact_th = kzalloc(TH_HEADER_LENGTH, gfp_type());
1358		if (ch->discontact_th == NULL)
1359					goto nomem_return;
1360
1361		ch->discontact_th->th_blk_flag = TH_DISCONTACT;
1362		tasklet_init(&ch->ch_disc_tasklet,
1363			mpc_action_send_discontact, (unsigned long)ch);
1364
1365		tasklet_init(&ch->ch_tasklet, ctcmpc_bh, (unsigned long)ch);
1366		ch->max_bufsize = (MPC_BUFSIZE_DEFAULT - 35);
1367		ccw_num = 17;
1368	} else
1369		ccw_num = 8;
1370
1371	ch->ccw = kcalloc(ccw_num, sizeof(struct ccw1), GFP_KERNEL | GFP_DMA);
1372	if (ch->ccw == NULL)
1373					goto nomem_return;
1374
1375	ch->cdev = cdev;
1376	snprintf(ch->id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev->dev));
1377	ch->type = type;
1378
1379	/**
1380	 * "static" ccws are used in the following way:
1381	 *
1382	 * ccw[0..2] (Channel program for generic I/O):
1383	 *           0: prepare
1384	 *           1: read or write (depending on direction) with fixed
1385	 *              buffer (idal allocated once when buffer is allocated)
1386	 *           2: nop
1387	 * ccw[3..5] (Channel program for direct write of packets)
1388	 *           3: prepare
1389	 *           4: write (idal allocated on every write).
1390	 *           5: nop
1391	 * ccw[6..7] (Channel program for initial channel setup):
1392	 *           6: set extended mode
1393	 *           7: nop
1394	 *
1395	 * ch->ccw[0..5] are initialized in ch_action_start because
1396	 * the channel's direction is yet unknown here.
1397	 *
1398	 * ccws used for xid2 negotiations
1399	 *  ch-ccw[8-14] need to be used for the XID exchange either
1400	 *    X side XID2 Processing
1401	 *       8:  write control
1402	 *       9:  write th
1403	 *	     10: write XID
1404	 *	     11: read th from secondary
1405	 *	     12: read XID   from secondary
1406	 *	     13: read 4 byte ID
1407	 *	     14: nop
1408	 *    Y side XID Processing
1409	 *	     8:  sense
1410	 *       9:  read th
1411	 *	     10: read XID
1412	 *	     11: write th
1413	 *	     12: write XID
1414	 *	     13: write 4 byte ID
1415	 *	     14: nop
1416	 *
1417	 *  ccws used for double noop due to VM timing issues
1418	 *  which result in unrecoverable Busy on channel
1419	 *       15: nop
1420	 *       16: nop
1421	 */
1422	ch->ccw[6].cmd_code	= CCW_CMD_SET_EXTENDED;
1423	ch->ccw[6].flags	= CCW_FLAG_SLI;
1424
1425	ch->ccw[7].cmd_code	= CCW_CMD_NOOP;
1426	ch->ccw[7].flags	= CCW_FLAG_SLI;
1427
1428	if (IS_MPC(priv)) {
1429		ch->ccw[15].cmd_code = CCW_CMD_WRITE;
1430		ch->ccw[15].flags    = CCW_FLAG_SLI | CCW_FLAG_CC;
1431		ch->ccw[15].count    = TH_HEADER_LENGTH;
1432		ch->ccw[15].cda      = virt_to_phys(ch->discontact_th);
1433
1434		ch->ccw[16].cmd_code = CCW_CMD_NOOP;
1435		ch->ccw[16].flags    = CCW_FLAG_SLI;
1436
1437		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
1438				ctc_ch_event_names, CTC_MPC_NR_STATES,
1439				CTC_MPC_NR_EVENTS, ctcmpc_ch_fsm,
1440				mpc_ch_fsm_len, GFP_KERNEL);
1441	} else {
1442		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
1443				ctc_ch_event_names, CTC_NR_STATES,
1444				CTC_NR_EVENTS, ch_fsm,
1445				ch_fsm_len, GFP_KERNEL);
1446	}
1447	if (ch->fsm == NULL)
1448				goto nomem_return;
1449
1450	fsm_newstate(ch->fsm, CTC_STATE_IDLE);
1451
1452	ch->irb = kzalloc(sizeof(struct irb), GFP_KERNEL);
1453	if (ch->irb == NULL)
1454				goto nomem_return;
1455
1456	while (*c && ctcm_less_than((*c)->id, ch->id))
1457		c = &(*c)->next;
1458
1459	if (*c && (!strncmp((*c)->id, ch->id, CTCM_ID_SIZE))) {
1460		CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1461				"%s (%s) already in list, using old entry",
1462				__func__, (*c)->id);
1463
1464				goto free_return;
1465	}
1466
1467	spin_lock_init(&ch->collect_lock);
1468
1469	fsm_settimer(ch->fsm, &ch->timer);
1470	skb_queue_head_init(&ch->io_queue);
1471	skb_queue_head_init(&ch->collect_queue);
1472
1473	if (IS_MPC(priv)) {
1474		fsm_settimer(ch->fsm, &ch->sweep_timer);
1475		skb_queue_head_init(&ch->sweep_queue);
1476	}
1477	ch->next = *c;
1478	*c = ch;
1479	return 0;
1480
1481nomem_return:
1482	rc = -ENOMEM;
1483
1484free_return:	/* note that all channel pointers are 0 or valid */
1485	kfree(ch->ccw);
1486	kfree(ch->discontact_th);
1487	kfree_fsm(ch->fsm);
1488	kfree(ch->irb);
1489	kfree(ch);
1490	return rc;
1491}
1492
1493/*
1494 * Return type of a detected device.
1495 */
1496static enum ctcm_channel_types get_channel_type(struct ccw_device_id *id)
1497{
1498	enum ctcm_channel_types type;
1499	type = (enum ctcm_channel_types)id->driver_info;
1500
1501	if (type == ctcm_channel_type_ficon)
1502		type = ctcm_channel_type_escon;
1503
1504	return type;
1505}
1506
1507/**
1508 *
1509 * Setup an interface.
1510 *
1511 *  cgdev	Device to be setup.
1512 *
1513 * returns 0 on success, !0 on failure.
1514 */
1515static int ctcm_new_device(struct ccwgroup_device *cgdev)
1516{
1517	char read_id[CTCM_ID_SIZE];
1518	char write_id[CTCM_ID_SIZE];
1519	int direction;
1520	enum ctcm_channel_types type;
1521	struct ctcm_priv *priv;
1522	struct net_device *dev;
1523	struct ccw_device *cdev0;
1524	struct ccw_device *cdev1;
1525	struct channel *readc;
1526	struct channel *writec;
1527	int ret;
1528	int result;
1529
1530	priv = dev_get_drvdata(&cgdev->dev);
1531	if (!priv) {
1532		result = -ENODEV;
1533		goto out_err_result;
1534	}
1535
1536	cdev0 = cgdev->cdev[0];
1537	cdev1 = cgdev->cdev[1];
1538
1539	type = get_channel_type(&cdev0->id);
1540
1541	snprintf(read_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev0->dev));
1542	snprintf(write_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev1->dev));
1543
1544	ret = add_channel(cdev0, type, priv);
1545	if (ret) {
1546		result = ret;
1547		goto out_err_result;
1548	}
1549	ret = add_channel(cdev1, type, priv);
1550	if (ret) {
1551		result = ret;
1552		goto out_remove_channel1;
1553	}
1554
1555	ret = ccw_device_set_online(cdev0);
1556	if (ret != 0) {
1557		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
1558			"%s(%s) set_online rc=%d",
1559				CTCM_FUNTAIL, read_id, ret);
1560		result = -EIO;
1561		goto out_remove_channel2;
1562	}
1563
1564	ret = ccw_device_set_online(cdev1);
1565	if (ret != 0) {
1566		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
1567			"%s(%s) set_online rc=%d",
1568				CTCM_FUNTAIL, write_id, ret);
1569
1570		result = -EIO;
1571		goto out_ccw1;
1572	}
1573
1574	dev = ctcm_init_netdevice(priv);
1575	if (dev == NULL) {
1576		result = -ENODEV;
1577		goto out_ccw2;
1578	}
1579
1580	for (direction = CTCM_READ; direction <= CTCM_WRITE; direction++) {
1581		priv->channel[direction] =
1582			channel_get(type, direction == CTCM_READ ?
1583				read_id : write_id, direction);
1584		if (priv->channel[direction] == NULL) {
1585			if (direction == CTCM_WRITE)
1586				channel_free(priv->channel[CTCM_READ]);
1587			result = -ENODEV;
1588			goto out_dev;
1589		}
1590		priv->channel[direction]->netdev = dev;
1591		priv->channel[direction]->protocol = priv->protocol;
1592		priv->channel[direction]->max_bufsize = priv->buffer_size;
1593	}
1594	/* sysfs magic */
1595	SET_NETDEV_DEV(dev, &cgdev->dev);
1596
1597	if (register_netdev(dev)) {
1598		result = -ENODEV;
1599		goto out_dev;
1600	}
1601
1602	strlcpy(priv->fsm->name, dev->name, sizeof(priv->fsm->name));
1603
1604	dev_info(&dev->dev,
1605		"setup OK : r/w = %s/%s, protocol : %d\n",
1606			priv->channel[CTCM_READ]->id,
1607			priv->channel[CTCM_WRITE]->id, priv->protocol);
1608
1609	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1610		"setup(%s) OK : r/w = %s/%s, protocol : %d", dev->name,
1611			priv->channel[CTCM_READ]->id,
1612			priv->channel[CTCM_WRITE]->id, priv->protocol);
1613
1614	return 0;
1615out_dev:
1616	ctcm_free_netdevice(dev);
1617out_ccw2:
1618	ccw_device_set_offline(cgdev->cdev[1]);
1619out_ccw1:
1620	ccw_device_set_offline(cgdev->cdev[0]);
1621out_remove_channel2:
1622	readc = channel_get(type, read_id, CTCM_READ);
1623	channel_remove(readc);
1624out_remove_channel1:
1625	writec = channel_get(type, write_id, CTCM_WRITE);
1626	channel_remove(writec);
1627out_err_result:
1628	return result;
1629}
1630
1631/**
1632 * Shutdown an interface.
1633 *
1634 *  cgdev	Device to be shut down.
1635 *
1636 * returns 0 on success, !0 on failure.
1637 */
1638static int ctcm_shutdown_device(struct ccwgroup_device *cgdev)
1639{
1640	struct ctcm_priv *priv;
1641	struct net_device *dev;
1642
1643	priv = dev_get_drvdata(&cgdev->dev);
1644	if (!priv)
1645		return -ENODEV;
1646
1647	if (priv->channel[CTCM_READ]) {
1648		dev = priv->channel[CTCM_READ]->netdev;
1649		CTCM_DBF_DEV(SETUP, dev, "");
1650		/* Close the device */
1651		ctcm_close(dev);
1652		dev->flags &= ~IFF_RUNNING;
1653		channel_free(priv->channel[CTCM_READ]);
1654	} else
1655		dev = NULL;
1656
1657	if (priv->channel[CTCM_WRITE])
1658		channel_free(priv->channel[CTCM_WRITE]);
1659
1660	if (dev) {
1661		unregister_netdev(dev);
1662		ctcm_free_netdevice(dev);
1663	}
1664
1665	if (priv->fsm)
1666		kfree_fsm(priv->fsm);
1667
1668	ccw_device_set_offline(cgdev->cdev[1]);
1669	ccw_device_set_offline(cgdev->cdev[0]);
1670	channel_remove(priv->channel[CTCM_READ]);
1671	channel_remove(priv->channel[CTCM_WRITE]);
1672	priv->channel[CTCM_READ] = priv->channel[CTCM_WRITE] = NULL;
1673
1674	return 0;
1675
1676}
1677
1678
1679static void ctcm_remove_device(struct ccwgroup_device *cgdev)
1680{
1681	struct ctcm_priv *priv = dev_get_drvdata(&cgdev->dev);
1682
1683	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
1684			"removing device %p, proto : %d",
1685			cgdev, priv->protocol);
1686
1687	if (cgdev->state == CCWGROUP_ONLINE)
1688		ctcm_shutdown_device(cgdev);
1689	dev_set_drvdata(&cgdev->dev, NULL);
1690	kfree(priv);
1691	put_device(&cgdev->dev);
1692}
1693
1694static struct ccw_device_id ctcm_ids[] = {
1695	{CCW_DEVICE(0x3088, 0x08), .driver_info = ctcm_channel_type_parallel},
1696	{CCW_DEVICE(0x3088, 0x1e), .driver_info = ctcm_channel_type_ficon},
1697	{CCW_DEVICE(0x3088, 0x1f), .driver_info = ctcm_channel_type_escon},
1698	{},
1699};
1700MODULE_DEVICE_TABLE(ccw, ctcm_ids);
1701
1702static struct ccw_driver ctcm_ccw_driver = {
1703	.driver = {
1704		.owner	= THIS_MODULE,
1705		.name	= "ctcm",
1706	},
1707	.ids	= ctcm_ids,
1708	.probe	= ccwgroup_probe_ccwdev,
1709	.remove	= ccwgroup_remove_ccwdev,
1710	.int_class = IRQIO_CTC,
1711};
1712
1713static struct ccwgroup_driver ctcm_group_driver = {
1714	.driver = {
1715		.owner	= THIS_MODULE,
1716		.name	= CTC_DRIVER_NAME,
1717	},
1718	.ccw_driver  = &ctcm_ccw_driver,
1719	.setup	     = ctcm_probe_device,
1720	.remove      = ctcm_remove_device,
1721	.set_online  = ctcm_new_device,
1722	.set_offline = ctcm_shutdown_device,
1723};
1724
1725static ssize_t group_store(struct device_driver *ddrv, const char *buf,
1726			   size_t count)
1727{
1728	int err;
1729
1730	err = ccwgroup_create_dev(ctcm_root_dev, &ctcm_group_driver, 2, buf);
1731	return err ? err : count;
1732}
1733static DRIVER_ATTR_WO(group);
1734
1735static struct attribute *ctcm_drv_attrs[] = {
1736	&driver_attr_group.attr,
1737	NULL,
1738};
1739static struct attribute_group ctcm_drv_attr_group = {
1740	.attrs = ctcm_drv_attrs,
1741};
1742static const struct attribute_group *ctcm_drv_attr_groups[] = {
1743	&ctcm_drv_attr_group,
1744	NULL,
1745};
1746
1747/*
1748 * Module related routines
1749 */
1750
1751/*
1752 * Prepare to be unloaded. Free IRQ's and release all resources.
1753 * This is called just before this module is unloaded. It is
1754 * not called, if the usage count is !0, so we don't need to check
1755 * for that.
1756 */
1757static void __exit ctcm_exit(void)
1758{
1759	ccwgroup_driver_unregister(&ctcm_group_driver);
1760	ccw_driver_unregister(&ctcm_ccw_driver);
1761	root_device_unregister(ctcm_root_dev);
1762	ctcm_unregister_dbf_views();
1763	pr_info("CTCM driver unloaded\n");
1764}
1765
1766/*
1767 * Print Banner.
1768 */
1769static void print_banner(void)
1770{
1771	pr_info("CTCM driver initialized\n");
1772}
1773
1774/**
1775 * Initialize module.
1776 * This is called just after the module is loaded.
1777 *
1778 * returns 0 on success, !0 on error.
1779 */
1780static int __init ctcm_init(void)
1781{
1782	int ret;
1783
1784	channels = NULL;
1785
1786	ret = ctcm_register_dbf_views();
1787	if (ret)
1788		goto out_err;
1789	ctcm_root_dev = root_device_register("ctcm");
1790	ret = PTR_ERR_OR_ZERO(ctcm_root_dev);
1791	if (ret)
1792		goto register_err;
1793	ret = ccw_driver_register(&ctcm_ccw_driver);
1794	if (ret)
1795		goto ccw_err;
1796	ctcm_group_driver.driver.groups = ctcm_drv_attr_groups;
1797	ret = ccwgroup_driver_register(&ctcm_group_driver);
1798	if (ret)
1799		goto ccwgroup_err;
1800	print_banner();
1801	return 0;
1802
1803ccwgroup_err:
1804	ccw_driver_unregister(&ctcm_ccw_driver);
1805ccw_err:
1806	root_device_unregister(ctcm_root_dev);
1807register_err:
1808	ctcm_unregister_dbf_views();
1809out_err:
1810	pr_err("%s / Initializing the ctcm device driver failed, ret = %d\n",
1811		__func__, ret);
1812	return ret;
1813}
1814
1815module_init(ctcm_init);
1816module_exit(ctcm_exit);
1817
1818MODULE_AUTHOR("Peter Tiedemann <ptiedem@de.ibm.com>");
1819MODULE_DESCRIPTION("Network driver for S/390 CTC + CTCMPC (SNA)");
1820MODULE_LICENSE("GPL");
1821
1822