xref: /openbmc/linux/drivers/s390/net/ctcm_mpc.c (revision 987a6485)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *	Copyright IBM Corp. 2004, 2007
4  *	Authors:	Belinda Thompson (belindat@us.ibm.com)
5  *			Andy Richter (richtera@us.ibm.com)
6  *			Peter Tiedemann (ptiedem@de.ibm.com)
7  */
8 
9 /*
10 	This module exports functions to be used by CCS:
11 	EXPORT_SYMBOL(ctc_mpc_alloc_channel);
12 	EXPORT_SYMBOL(ctc_mpc_establish_connectivity);
13 	EXPORT_SYMBOL(ctc_mpc_dealloc_ch);
14 	EXPORT_SYMBOL(ctc_mpc_flow_control);
15 */
16 
17 #undef DEBUG
18 #undef DEBUGDATA
19 #undef DEBUGCCW
20 
21 #define KMSG_COMPONENT "ctcm"
22 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/kernel.h>
27 #include <linux/slab.h>
28 #include <linux/errno.h>
29 #include <linux/types.h>
30 #include <linux/interrupt.h>
31 #include <linux/timer.h>
32 #include <linux/sched.h>
33 
34 #include <linux/signal.h>
35 #include <linux/string.h>
36 #include <linux/proc_fs.h>
37 
38 #include <linux/ip.h>
39 #include <linux/if_arp.h>
40 #include <linux/tcp.h>
41 #include <linux/skbuff.h>
42 #include <linux/ctype.h>
43 #include <linux/netdevice.h>
44 #include <net/dst.h>
45 
46 #include <linux/io.h>		/* instead of <asm/io.h> ok ? */
47 #include <asm/ccwdev.h>
48 #include <asm/ccwgroup.h>
49 #include <linux/bitops.h>	/* instead of <asm/bitops.h> ok ? */
50 #include <linux/uaccess.h>	/* instead of <asm/uaccess.h> ok ? */
51 #include <linux/wait.h>
52 #include <linux/moduleparam.h>
53 #include <asm/idals.h>
54 
55 #include "ctcm_main.h"
56 #include "ctcm_mpc.h"
57 #include "ctcm_fsms.h"
58 
59 static const struct xid2 init_xid = {
60 	.xid2_type_id	=	XID_FM2,
61 	.xid2_len	=	0x45,
62 	.xid2_adj_id	=	0,
63 	.xid2_rlen	=	0x31,
64 	.xid2_resv1	=	0,
65 	.xid2_flag1	=	0,
66 	.xid2_fmtt	=	0,
67 	.xid2_flag4	=	0x80,
68 	.xid2_resv2	=	0,
69 	.xid2_tgnum	=	0,
70 	.xid2_sender_id	=	0,
71 	.xid2_flag2	=	0,
72 	.xid2_option	=	XID2_0,
73 	.xid2_resv3	=	"\x00",
74 	.xid2_resv4	=	0,
75 	.xid2_dlc_type	=	XID2_READ_SIDE,
76 	.xid2_resv5	=	0,
77 	.xid2_mpc_flag	=	0,
78 	.xid2_resv6	=	0,
79 	.xid2_buf_len	=	(MPC_BUFSIZE_DEFAULT - 35),
80 };
81 
82 static const struct th_header thnorm = {
83 	.th_seg		=	0x00,
84 	.th_ch_flag	=	TH_IS_XID,
85 	.th_blk_flag	=	TH_DATA_IS_XID,
86 	.th_is_xid	=	0x01,
87 	.th_seq_num	=	0x00000000,
88 };
89 
90 static const struct th_header thdummy = {
91 	.th_seg		=	0x00,
92 	.th_ch_flag	=	0x00,
93 	.th_blk_flag	=	TH_DATA_IS_XID,
94 	.th_is_xid	=	0x01,
95 	.th_seq_num	=	0x00000000,
96 };
97 
98 /*
99  * Definition of one MPC group
100  */
101 
102 /*
103  * Compatibility macros for busy handling
104  * of network devices.
105  */
106 
107 static void ctcmpc_unpack_skb(struct channel *ch, struct sk_buff *pskb);
108 
109 /*
110  * MPC Group state machine actions (static prototypes)
111  */
112 static void mpc_action_nop(fsm_instance *fsm, int event, void *arg);
113 static void mpc_action_go_ready(fsm_instance *fsm, int event, void *arg);
114 static void mpc_action_go_inop(fsm_instance *fi, int event, void *arg);
115 static void mpc_action_timeout(fsm_instance *fi, int event, void *arg);
116 static int  mpc_validate_xid(struct mpcg_info *mpcginfo);
117 static void mpc_action_yside_xid(fsm_instance *fsm, int event, void *arg);
118 static void mpc_action_doxid0(fsm_instance *fsm, int event, void *arg);
119 static void mpc_action_doxid7(fsm_instance *fsm, int event, void *arg);
120 static void mpc_action_xside_xid(fsm_instance *fsm, int event, void *arg);
121 static void mpc_action_rcvd_xid0(fsm_instance *fsm, int event, void *arg);
122 static void mpc_action_rcvd_xid7(fsm_instance *fsm, int event, void *arg);
123 
124 #ifdef DEBUGDATA
125 /*-------------------------------------------------------------------*
126 * Dump buffer format						     *
127 *								     *
128 *--------------------------------------------------------------------*/
129 void ctcmpc_dumpit(char *buf, int len)
130 {
131 	__u32	ct, sw, rm, dup;
132 	char	*ptr, *rptr;
133 	char	tbuf[82], tdup[82];
134 	char	addr[22];
135 	char	boff[12];
136 	char	bhex[82], duphex[82];
137 	char	basc[40];
138 
139 	sw  = 0;
140 	rptr = ptr = buf;
141 	rm  = 16;
142 	duphex[0] = 0x00;
143 	dup = 0;
144 
145 	for (ct = 0; ct < len; ct++, ptr++, rptr++) {
146 		if (sw == 0) {
147 			sprintf(addr, "%16.16llx", (__u64)rptr);
148 
149 			sprintf(boff, "%4.4X", (__u32)ct);
150 			bhex[0] = '\0';
151 			basc[0] = '\0';
152 		}
153 		if ((sw == 4) || (sw == 12))
154 			strcat(bhex, " ");
155 		if (sw == 8)
156 			strcat(bhex, "	");
157 
158 		sprintf(tbuf, "%2.2llX", (__u64)*ptr);
159 
160 		tbuf[2] = '\0';
161 		strcat(bhex, tbuf);
162 		if ((0 != isprint(*ptr)) && (*ptr >= 0x20))
163 			basc[sw] = *ptr;
164 		else
165 			basc[sw] = '.';
166 
167 		basc[sw+1] = '\0';
168 		sw++;
169 		rm--;
170 		if (sw != 16)
171 			continue;
172 		if ((strcmp(duphex, bhex)) != 0) {
173 			if (dup != 0) {
174 				sprintf(tdup,
175 					"Duplicate as above to %s", addr);
176 				ctcm_pr_debug("		       --- %s ---\n",
177 						tdup);
178 			}
179 			ctcm_pr_debug("   %s (+%s) : %s  [%s]\n",
180 					addr, boff, bhex, basc);
181 			dup = 0;
182 			strcpy(duphex, bhex);
183 		} else
184 			dup++;
185 
186 		sw = 0;
187 		rm = 16;
188 	}  /* endfor */
189 
190 	if (sw != 0) {
191 		for ( ; rm > 0; rm--, sw++) {
192 			if ((sw == 4) || (sw == 12))
193 				strcat(bhex, " ");
194 			if (sw == 8)
195 				strcat(bhex, "	");
196 			strcat(bhex, "	");
197 			strcat(basc, " ");
198 		}
199 		if (dup != 0) {
200 			sprintf(tdup, "Duplicate as above to %s", addr);
201 			ctcm_pr_debug("		       --- %s ---\n", tdup);
202 		}
203 		ctcm_pr_debug("   %s (+%s) : %s  [%s]\n",
204 					addr, boff, bhex, basc);
205 	} else {
206 		if (dup >= 1) {
207 			sprintf(tdup, "Duplicate as above to %s", addr);
208 			ctcm_pr_debug("		       --- %s ---\n", tdup);
209 		}
210 		if (dup != 0) {
211 			ctcm_pr_debug("   %s (+%s) : %s  [%s]\n",
212 				addr, boff, bhex, basc);
213 		}
214 	}
215 
216 	return;
217 
218 }   /*	 end of ctcmpc_dumpit  */
219 #endif
220 
221 #ifdef DEBUGDATA
222 /*
223  * Dump header and first 16 bytes of an sk_buff for debugging purposes.
224  *
225  * skb		The sk_buff to dump.
226  * offset	Offset relative to skb-data, where to start the dump.
227  */
228 void ctcmpc_dump_skb(struct sk_buff *skb, int offset)
229 {
230 	__u8 *p = skb->data;
231 	struct th_header *header;
232 	struct pdu *pheader;
233 	int bl = skb->len;
234 	int i;
235 
236 	if (p == NULL)
237 		return;
238 
239 	p += offset;
240 	header = (struct th_header *)p;
241 
242 	ctcm_pr_debug("dump:\n");
243 	ctcm_pr_debug("skb len=%d \n", skb->len);
244 	if (skb->len > 2) {
245 		switch (header->th_ch_flag) {
246 		case TH_HAS_PDU:
247 			break;
248 		case 0x00:
249 		case TH_IS_XID:
250 			if ((header->th_blk_flag == TH_DATA_IS_XID) &&
251 			   (header->th_is_xid == 0x01))
252 				goto dumpth;
253 		case TH_SWEEP_REQ:
254 				goto dumpth;
255 		case TH_SWEEP_RESP:
256 				goto dumpth;
257 		default:
258 			break;
259 		}
260 
261 		pheader = (struct pdu *)p;
262 		ctcm_pr_debug("pdu->offset: %d hex: %04x\n",
263 			       pheader->pdu_offset, pheader->pdu_offset);
264 		ctcm_pr_debug("pdu->flag  : %02x\n", pheader->pdu_flag);
265 		ctcm_pr_debug("pdu->proto : %02x\n", pheader->pdu_proto);
266 		ctcm_pr_debug("pdu->seq   : %02x\n", pheader->pdu_seq);
267 					goto dumpdata;
268 
269 dumpth:
270 		ctcm_pr_debug("th->seg     : %02x\n", header->th_seg);
271 		ctcm_pr_debug("th->ch      : %02x\n", header->th_ch_flag);
272 		ctcm_pr_debug("th->blk_flag: %02x\n", header->th_blk_flag);
273 		ctcm_pr_debug("th->type    : %s\n",
274 			       (header->th_is_xid) ? "DATA" : "XID");
275 		ctcm_pr_debug("th->seqnum  : %04x\n", header->th_seq_num);
276 
277 	}
278 dumpdata:
279 	if (bl > 32)
280 		bl = 32;
281 	ctcm_pr_debug("data: ");
282 	for (i = 0; i < bl; i++)
283 		ctcm_pr_debug("%02x%s", *p++, (i % 16) ? " " : "\n");
284 	ctcm_pr_debug("\n");
285 }
286 #endif
287 
288 static struct net_device *ctcmpc_get_dev(int port_num)
289 {
290 	char device[20];
291 	struct net_device *dev;
292 	struct ctcm_priv *priv;
293 
294 	sprintf(device, "%s%i", MPC_DEVICE_NAME, port_num);
295 
296 	dev = __dev_get_by_name(&init_net, device);
297 
298 	if (dev == NULL) {
299 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
300 			"%s: Device not found by name: %s",
301 					CTCM_FUNTAIL, device);
302 		return NULL;
303 	}
304 	priv = dev->ml_priv;
305 	if (priv == NULL) {
306 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
307 			"%s(%s): dev->ml_priv is NULL",
308 					CTCM_FUNTAIL, device);
309 		return NULL;
310 	}
311 	if (priv->mpcg == NULL) {
312 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
313 			"%s(%s): priv->mpcg is NULL",
314 					CTCM_FUNTAIL, device);
315 		return NULL;
316 	}
317 	return dev;
318 }
319 
320 /*
321  * ctc_mpc_alloc_channel
322  *	(exported interface)
323  *
324  * Device Initialization :
325  *	ACTPATH  driven IO operations
326  */
327 int ctc_mpc_alloc_channel(int port_num, void (*callback)(int, int))
328 {
329 	struct net_device *dev;
330 	struct mpc_group *grp;
331 	struct ctcm_priv *priv;
332 
333 	dev = ctcmpc_get_dev(port_num);
334 	if (dev == NULL)
335 		return 1;
336 	priv = dev->ml_priv;
337 	grp = priv->mpcg;
338 
339 	grp->allochanfunc = callback;
340 	grp->port_num = port_num;
341 	grp->port_persist = 1;
342 
343 	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_INFO,
344 			"%s(%s): state=%s",
345 			CTCM_FUNTAIL, dev->name, fsm_getstate_str(grp->fsm));
346 
347 	switch (fsm_getstate(grp->fsm)) {
348 	case MPCG_STATE_INOP:
349 		/* Group is in the process of terminating */
350 		grp->alloc_called = 1;
351 		break;
352 	case MPCG_STATE_RESET:
353 		/* MPC Group will transition to state		  */
354 		/* MPCG_STATE_XID2INITW iff the minimum number	  */
355 		/* of 1 read and 1 write channel have successfully*/
356 		/* activated					  */
357 		/*fsm_newstate(grp->fsm, MPCG_STATE_XID2INITW);*/
358 		if (callback)
359 			grp->send_qllc_disc = 1;
360 		fallthrough;
361 	case MPCG_STATE_XID0IOWAIT:
362 		fsm_deltimer(&grp->timer);
363 		grp->outstanding_xid2 = 0;
364 		grp->outstanding_xid7 = 0;
365 		grp->outstanding_xid7_p2 = 0;
366 		grp->saved_xid2 = NULL;
367 		if (callback)
368 			ctcm_open(dev);
369 		fsm_event(priv->fsm, DEV_EVENT_START, dev);
370 		break;
371 	case MPCG_STATE_READY:
372 		/* XID exchanges completed after PORT was activated */
373 		/* Link station already active			    */
374 		/* Maybe timing issue...retry callback		    */
375 		grp->allocchan_callback_retries++;
376 		if (grp->allocchan_callback_retries < 4) {
377 			if (grp->allochanfunc)
378 				grp->allochanfunc(grp->port_num,
379 						  grp->group_max_buflen);
380 		} else {
381 			/* there are problems...bail out	    */
382 			/* there may be a state mismatch so restart */
383 			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
384 			grp->allocchan_callback_retries = 0;
385 		}
386 		break;
387 	}
388 
389 	return 0;
390 }
391 EXPORT_SYMBOL(ctc_mpc_alloc_channel);
392 
393 /*
394  * ctc_mpc_establish_connectivity
395  *	(exported interface)
396  */
397 void ctc_mpc_establish_connectivity(int port_num,
398 				void (*callback)(int, int, int))
399 {
400 	struct net_device *dev;
401 	struct mpc_group *grp;
402 	struct ctcm_priv *priv;
403 	struct channel *rch, *wch;
404 
405 	dev = ctcmpc_get_dev(port_num);
406 	if (dev == NULL)
407 		return;
408 	priv = dev->ml_priv;
409 	grp = priv->mpcg;
410 	rch = priv->channel[CTCM_READ];
411 	wch = priv->channel[CTCM_WRITE];
412 
413 	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_INFO,
414 			"%s(%s): state=%s",
415 			CTCM_FUNTAIL, dev->name, fsm_getstate_str(grp->fsm));
416 
417 	grp->estconnfunc = callback;
418 	grp->port_num = port_num;
419 
420 	switch (fsm_getstate(grp->fsm)) {
421 	case MPCG_STATE_READY:
422 		/* XID exchanges completed after PORT was activated */
423 		/* Link station already active			    */
424 		/* Maybe timing issue...retry callback		    */
425 		fsm_deltimer(&grp->timer);
426 		grp->estconn_callback_retries++;
427 		if (grp->estconn_callback_retries < 4) {
428 			if (grp->estconnfunc) {
429 				grp->estconnfunc(grp->port_num, 0,
430 						grp->group_max_buflen);
431 				grp->estconnfunc = NULL;
432 			}
433 		} else {
434 			/* there are problems...bail out	 */
435 			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
436 			grp->estconn_callback_retries = 0;
437 		}
438 		break;
439 	case MPCG_STATE_INOP:
440 	case MPCG_STATE_RESET:
441 		/* MPC Group is not ready to start XID - min num of */
442 		/* 1 read and 1 write channel have not been acquired*/
443 
444 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
445 			"%s(%s): REJECTED - inactive channels",
446 					CTCM_FUNTAIL, dev->name);
447 		if (grp->estconnfunc) {
448 			grp->estconnfunc(grp->port_num, -1, 0);
449 			grp->estconnfunc = NULL;
450 		}
451 		break;
452 	case MPCG_STATE_XID2INITW:
453 		/* alloc channel was called but no XID exchange    */
454 		/* has occurred. initiate xside XID exchange	   */
455 		/* make sure yside XID0 processing has not started */
456 
457 		if ((fsm_getstate(rch->fsm) > CH_XID0_PENDING) ||
458 			(fsm_getstate(wch->fsm) > CH_XID0_PENDING)) {
459 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
460 				"%s(%s): ABORT - PASSIVE XID",
461 					CTCM_FUNTAIL, dev->name);
462 			break;
463 		}
464 		grp->send_qllc_disc = 1;
465 		fsm_newstate(grp->fsm, MPCG_STATE_XID0IOWAIT);
466 		fsm_deltimer(&grp->timer);
467 		fsm_addtimer(&grp->timer, MPC_XID_TIMEOUT_VALUE,
468 						MPCG_EVENT_TIMER, dev);
469 		grp->outstanding_xid7 = 0;
470 		grp->outstanding_xid7_p2 = 0;
471 		grp->saved_xid2 = NULL;
472 		if ((rch->in_mpcgroup) &&
473 				(fsm_getstate(rch->fsm) == CH_XID0_PENDING))
474 			fsm_event(grp->fsm, MPCG_EVENT_XID0DO, rch);
475 		else {
476 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
477 				"%s(%s): RX-%s not ready for ACTIVE XID0",
478 					CTCM_FUNTAIL, dev->name, rch->id);
479 			if (grp->estconnfunc) {
480 				grp->estconnfunc(grp->port_num, -1, 0);
481 				grp->estconnfunc = NULL;
482 			}
483 			fsm_deltimer(&grp->timer);
484 				goto done;
485 		}
486 		if ((wch->in_mpcgroup) &&
487 				(fsm_getstate(wch->fsm) == CH_XID0_PENDING))
488 			fsm_event(grp->fsm, MPCG_EVENT_XID0DO, wch);
489 		else {
490 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
491 				"%s(%s): WX-%s not ready for ACTIVE XID0",
492 					CTCM_FUNTAIL, dev->name, wch->id);
493 			if (grp->estconnfunc) {
494 				grp->estconnfunc(grp->port_num, -1, 0);
495 				grp->estconnfunc = NULL;
496 			}
497 			fsm_deltimer(&grp->timer);
498 				goto done;
499 			}
500 		break;
501 	case MPCG_STATE_XID0IOWAIT:
502 		/* already in active XID negotiations */
503 	default:
504 		break;
505 	}
506 
507 done:
508 	CTCM_PR_DEBUG("Exit %s()\n", __func__);
509 	return;
510 }
511 EXPORT_SYMBOL(ctc_mpc_establish_connectivity);
512 
513 /*
514  * ctc_mpc_dealloc_ch
515  *	(exported interface)
516  */
517 void ctc_mpc_dealloc_ch(int port_num)
518 {
519 	struct net_device *dev;
520 	struct ctcm_priv *priv;
521 	struct mpc_group *grp;
522 
523 	dev = ctcmpc_get_dev(port_num);
524 	if (dev == NULL)
525 		return;
526 	priv = dev->ml_priv;
527 	grp = priv->mpcg;
528 
529 	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_DEBUG,
530 			"%s: %s: refcount = %d\n",
531 			CTCM_FUNTAIL, dev->name, netdev_refcnt_read(dev));
532 
533 	fsm_deltimer(&priv->restart_timer);
534 	grp->channels_terminating = 0;
535 	fsm_deltimer(&grp->timer);
536 	grp->allochanfunc = NULL;
537 	grp->estconnfunc = NULL;
538 	grp->port_persist = 0;
539 	grp->send_qllc_disc = 0;
540 	fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
541 
542 	ctcm_close(dev);
543 	return;
544 }
545 EXPORT_SYMBOL(ctc_mpc_dealloc_ch);
546 
547 /*
548  * ctc_mpc_flow_control
549  *	(exported interface)
550  */
551 void ctc_mpc_flow_control(int port_num, int flowc)
552 {
553 	struct ctcm_priv *priv;
554 	struct mpc_group *grp;
555 	struct net_device *dev;
556 	struct channel *rch;
557 	int mpcg_state;
558 
559 	dev = ctcmpc_get_dev(port_num);
560 	if (dev == NULL)
561 		return;
562 	priv = dev->ml_priv;
563 	grp = priv->mpcg;
564 
565 	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
566 			"%s: %s: flowc = %d",
567 				CTCM_FUNTAIL, dev->name, flowc);
568 
569 	rch = priv->channel[CTCM_READ];
570 
571 	mpcg_state = fsm_getstate(grp->fsm);
572 	switch (flowc) {
573 	case 1:
574 		if (mpcg_state == MPCG_STATE_FLOWC)
575 			break;
576 		if (mpcg_state == MPCG_STATE_READY) {
577 			if (grp->flow_off_called == 1)
578 				grp->flow_off_called = 0;
579 			else
580 				fsm_newstate(grp->fsm, MPCG_STATE_FLOWC);
581 			break;
582 		}
583 		break;
584 	case 0:
585 		if (mpcg_state == MPCG_STATE_FLOWC) {
586 			fsm_newstate(grp->fsm, MPCG_STATE_READY);
587 			/* ensure any data that has accumulated */
588 			/* on the io_queue will now be sen t	*/
589 			tasklet_schedule(&rch->ch_tasklet);
590 		}
591 		/* possible race condition			*/
592 		if (mpcg_state == MPCG_STATE_READY) {
593 			grp->flow_off_called = 1;
594 			break;
595 		}
596 		break;
597 	}
598 
599 }
600 EXPORT_SYMBOL(ctc_mpc_flow_control);
601 
602 static int mpc_send_qllc_discontact(struct net_device *);
603 
604 /*
605  * helper function of ctcmpc_unpack_skb
606 */
607 static void mpc_rcvd_sweep_resp(struct mpcg_info *mpcginfo)
608 {
609 	struct channel	  *rch = mpcginfo->ch;
610 	struct net_device *dev = rch->netdev;
611 	struct ctcm_priv   *priv = dev->ml_priv;
612 	struct mpc_group  *grp = priv->mpcg;
613 	struct channel	  *ch = priv->channel[CTCM_WRITE];
614 
615 	CTCM_PR_DEBUG("%s: ch=0x%p id=%s\n", __func__, ch, ch->id);
616 	CTCM_D3_DUMP((char *)mpcginfo->sweep, TH_SWEEP_LENGTH);
617 
618 	grp->sweep_rsp_pend_num--;
619 
620 	if ((grp->sweep_req_pend_num == 0) &&
621 			(grp->sweep_rsp_pend_num == 0)) {
622 		fsm_deltimer(&ch->sweep_timer);
623 		grp->in_sweep = 0;
624 		rch->th_seq_num = 0x00;
625 		ch->th_seq_num = 0x00;
626 		ctcm_clear_busy_do(dev);
627 	}
628 
629 	kfree(mpcginfo);
630 
631 	return;
632 
633 }
634 
635 /*
636  * helper function of mpc_rcvd_sweep_req
637  * which is a helper of ctcmpc_unpack_skb
638  */
639 static void ctcmpc_send_sweep_resp(struct channel *rch)
640 {
641 	struct net_device *dev = rch->netdev;
642 	struct ctcm_priv *priv = dev->ml_priv;
643 	struct mpc_group *grp = priv->mpcg;
644 	struct th_sweep *header;
645 	struct sk_buff *sweep_skb;
646 	struct channel *ch  = priv->channel[CTCM_WRITE];
647 
648 	CTCM_PR_DEBUG("%s: ch=0x%p id=%s\n", __func__, rch, rch->id);
649 
650 	sweep_skb = __dev_alloc_skb(MPC_BUFSIZE_DEFAULT, GFP_ATOMIC | GFP_DMA);
651 	if (sweep_skb == NULL) {
652 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
653 			"%s(%s): sweep_skb allocation ERROR\n",
654 			CTCM_FUNTAIL, rch->id);
655 		goto done;
656 	}
657 
658 	header = kmalloc(sizeof(struct th_sweep), gfp_type());
659 
660 	if (!header) {
661 		dev_kfree_skb_any(sweep_skb);
662 		goto done;
663 	}
664 
665 	header->th.th_seg	= 0x00 ;
666 	header->th.th_ch_flag	= TH_SWEEP_RESP;
667 	header->th.th_blk_flag	= 0x00;
668 	header->th.th_is_xid	= 0x00;
669 	header->th.th_seq_num	= 0x00;
670 	header->sw.th_last_seq	= ch->th_seq_num;
671 
672 	skb_put_data(sweep_skb, header, TH_SWEEP_LENGTH);
673 
674 	kfree(header);
675 
676 	netif_trans_update(dev);
677 	skb_queue_tail(&ch->sweep_queue, sweep_skb);
678 
679 	fsm_addtimer(&ch->sweep_timer, 100, CTC_EVENT_RSWEEP_TIMER, ch);
680 
681 	return;
682 
683 done:
684 	grp->in_sweep = 0;
685 	ctcm_clear_busy_do(dev);
686 	fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
687 
688 	return;
689 }
690 
691 /*
692  * helper function of ctcmpc_unpack_skb
693  */
694 static void mpc_rcvd_sweep_req(struct mpcg_info *mpcginfo)
695 {
696 	struct channel	  *rch     = mpcginfo->ch;
697 	struct net_device *dev     = rch->netdev;
698 	struct ctcm_priv  *priv = dev->ml_priv;
699 	struct mpc_group  *grp  = priv->mpcg;
700 	struct channel	  *ch	   = priv->channel[CTCM_WRITE];
701 
702 	if (do_debug)
703 		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
704 			" %s(): ch=0x%p id=%s\n", __func__, ch, ch->id);
705 
706 	if (grp->in_sweep == 0) {
707 		grp->in_sweep = 1;
708 		ctcm_test_and_set_busy(dev);
709 		grp->sweep_req_pend_num = grp->active_channels[CTCM_READ];
710 		grp->sweep_rsp_pend_num = grp->active_channels[CTCM_READ];
711 	}
712 
713 	CTCM_D3_DUMP((char *)mpcginfo->sweep, TH_SWEEP_LENGTH);
714 
715 	grp->sweep_req_pend_num--;
716 	ctcmpc_send_sweep_resp(ch);
717 	kfree(mpcginfo);
718 	return;
719 }
720 
721 /*
722   * MPC Group Station FSM definitions
723  */
724 static const char *mpcg_event_names[] = {
725 	[MPCG_EVENT_INOP]	= "INOP Condition",
726 	[MPCG_EVENT_DISCONC]	= "Discontact Received",
727 	[MPCG_EVENT_XID0DO]	= "Channel Active - Start XID",
728 	[MPCG_EVENT_XID2]	= "XID2 Received",
729 	[MPCG_EVENT_XID2DONE]	= "XID0 Complete",
730 	[MPCG_EVENT_XID7DONE]	= "XID7 Complete",
731 	[MPCG_EVENT_TIMER]	= "XID Setup Timer",
732 	[MPCG_EVENT_DOIO]	= "XID DoIO",
733 };
734 
735 static const char *mpcg_state_names[] = {
736 	[MPCG_STATE_RESET]	= "Reset",
737 	[MPCG_STATE_INOP]	= "INOP",
738 	[MPCG_STATE_XID2INITW]	= "Passive XID- XID0 Pending Start",
739 	[MPCG_STATE_XID2INITX]	= "Passive XID- XID0 Pending Complete",
740 	[MPCG_STATE_XID7INITW]	= "Passive XID- XID7 Pending P1 Start",
741 	[MPCG_STATE_XID7INITX]	= "Passive XID- XID7 Pending P2 Complete",
742 	[MPCG_STATE_XID0IOWAIT]	= "Active  XID- XID0 Pending Start",
743 	[MPCG_STATE_XID0IOWAIX]	= "Active  XID- XID0 Pending Complete",
744 	[MPCG_STATE_XID7INITI]	= "Active  XID- XID7 Pending Start",
745 	[MPCG_STATE_XID7INITZ]	= "Active  XID- XID7 Pending Complete ",
746 	[MPCG_STATE_XID7INITF]	= "XID        - XID7 Complete ",
747 	[MPCG_STATE_FLOWC]	= "FLOW CONTROL ON",
748 	[MPCG_STATE_READY]	= "READY",
749 };
750 
751 /*
752  * The MPC Group Station FSM
753  *   22 events
754  */
755 static const fsm_node mpcg_fsm[] = {
756 	{ MPCG_STATE_RESET,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
757 	{ MPCG_STATE_INOP,	MPCG_EVENT_INOP,	mpc_action_nop        },
758 	{ MPCG_STATE_FLOWC,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
759 
760 	{ MPCG_STATE_READY,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
761 	{ MPCG_STATE_READY,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
762 
763 	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_XID0DO,	mpc_action_doxid0     },
764 	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid0  },
765 	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
766 	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
767 	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_DOIO,	mpc_action_yside_xid  },
768 
769 	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_XID0DO,	mpc_action_doxid0     },
770 	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid0  },
771 	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
772 	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
773 	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_DOIO,	mpc_action_yside_xid  },
774 
775 	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_XID2DONE,	mpc_action_doxid7     },
776 	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
777 	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid7  },
778 	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
779 	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
780 	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_XID7DONE,	mpc_action_doxid7     },
781 	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_DOIO,	mpc_action_yside_xid  },
782 
783 	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
784 	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid7  },
785 	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
786 	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_XID7DONE,	mpc_action_doxid7     },
787 	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
788 	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_DOIO,	mpc_action_yside_xid  },
789 
790 	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_XID0DO,	mpc_action_doxid0     },
791 	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_DISCONC,	mpc_action_discontact },
792 	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_XID2,	mpc_action_rcvd_xid0  },
793 	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_INOP,	mpc_action_go_inop    },
794 	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_TIMER,	mpc_action_timeout    },
795 	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_DOIO,	mpc_action_xside_xid  },
796 
797 	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_XID0DO,	mpc_action_doxid0     },
798 	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_DISCONC,	mpc_action_discontact },
799 	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_XID2,	mpc_action_rcvd_xid0  },
800 	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_INOP,	mpc_action_go_inop    },
801 	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_TIMER,	mpc_action_timeout    },
802 	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_DOIO,	mpc_action_xside_xid  },
803 
804 	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_XID2DONE,	mpc_action_doxid7     },
805 	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid7  },
806 	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
807 	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
808 	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
809 	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_XID7DONE,	mpc_action_doxid7     },
810 	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_DOIO,	mpc_action_xside_xid  },
811 
812 	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid7  },
813 	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_XID7DONE,	mpc_action_doxid7     },
814 	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
815 	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
816 	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
817 	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_DOIO,	mpc_action_xside_xid  },
818 
819 	{ MPCG_STATE_XID7INITF,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
820 	{ MPCG_STATE_XID7INITF,	MPCG_EVENT_XID7DONE,	mpc_action_go_ready   },
821 };
822 
823 static int mpcg_fsm_len = ARRAY_SIZE(mpcg_fsm);
824 
825 /*
826  * MPC Group Station FSM action
827  * CTCM_PROTO_MPC only
828  */
829 static void mpc_action_go_ready(fsm_instance *fsm, int event, void *arg)
830 {
831 	struct net_device *dev = arg;
832 	struct ctcm_priv *priv = dev->ml_priv;
833 	struct mpc_group *grp = priv->mpcg;
834 
835 	if (grp == NULL) {
836 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
837 			"%s(%s): No MPC group",
838 				CTCM_FUNTAIL, dev->name);
839 		return;
840 	}
841 
842 	fsm_deltimer(&grp->timer);
843 
844 	if (grp->saved_xid2->xid2_flag2 == 0x40) {
845 		priv->xid->xid2_flag2 = 0x00;
846 		if (grp->estconnfunc) {
847 			grp->estconnfunc(grp->port_num, 1,
848 					grp->group_max_buflen);
849 			grp->estconnfunc = NULL;
850 		} else if (grp->allochanfunc)
851 			grp->send_qllc_disc = 1;
852 
853 		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
854 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
855 				"%s(%s): fails",
856 					CTCM_FUNTAIL, dev->name);
857 		return;
858 	}
859 
860 	grp->port_persist = 1;
861 	grp->out_of_sequence = 0;
862 	grp->estconn_called = 0;
863 
864 	tasklet_hi_schedule(&grp->mpc_tasklet2);
865 
866 	return;
867 }
868 
869 /*
870  * helper of ctcm_init_netdevice
871  * CTCM_PROTO_MPC only
872  */
873 void mpc_group_ready(unsigned long adev)
874 {
875 	struct net_device *dev = (struct net_device *)adev;
876 	struct ctcm_priv *priv = dev->ml_priv;
877 	struct mpc_group *grp = priv->mpcg;
878 	struct channel *ch = NULL;
879 
880 	if (grp == NULL) {
881 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
882 			"%s(%s): No MPC group",
883 				CTCM_FUNTAIL, dev->name);
884 		return;
885 	}
886 
887 	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_NOTICE,
888 		"%s: %s: GROUP TRANSITIONED TO READY, maxbuf = %d\n",
889 			CTCM_FUNTAIL, dev->name, grp->group_max_buflen);
890 
891 	fsm_newstate(grp->fsm, MPCG_STATE_READY);
892 
893 	/* Put up a read on the channel */
894 	ch = priv->channel[CTCM_READ];
895 	ch->pdu_seq = 0;
896 	CTCM_PR_DBGDATA("ctcmpc: %s() ToDCM_pdu_seq= %08x\n" ,
897 			__func__, ch->pdu_seq);
898 
899 	ctcmpc_chx_rxidle(ch->fsm, CTC_EVENT_START, ch);
900 	/* Put the write channel in idle state */
901 	ch = priv->channel[CTCM_WRITE];
902 	if (ch->collect_len > 0) {
903 		spin_lock(&ch->collect_lock);
904 		ctcm_purge_skb_queue(&ch->collect_queue);
905 		ch->collect_len = 0;
906 		spin_unlock(&ch->collect_lock);
907 	}
908 	ctcm_chx_txidle(ch->fsm, CTC_EVENT_START, ch);
909 	ctcm_clear_busy(dev);
910 
911 	if (grp->estconnfunc) {
912 		grp->estconnfunc(grp->port_num, 0,
913 				    grp->group_max_buflen);
914 		grp->estconnfunc = NULL;
915 	} else 	if (grp->allochanfunc)
916 		grp->allochanfunc(grp->port_num, grp->group_max_buflen);
917 
918 	grp->send_qllc_disc = 1;
919 	grp->changed_side = 0;
920 
921 	return;
922 
923 }
924 
925 /*
926  * Increment the MPC Group Active Channel Counts
927  * helper of dev_action (called from channel fsm)
928  */
929 void mpc_channel_action(struct channel *ch, int direction, int action)
930 {
931 	struct net_device  *dev  = ch->netdev;
932 	struct ctcm_priv   *priv = dev->ml_priv;
933 	struct mpc_group   *grp  = priv->mpcg;
934 
935 	if (grp == NULL) {
936 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
937 			"%s(%s): No MPC group",
938 				CTCM_FUNTAIL, dev->name);
939 		return;
940 	}
941 
942 	CTCM_PR_DEBUG("enter %s: ch=0x%p id=%s\n", __func__, ch, ch->id);
943 
944 	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
945 		"%s: %i / Grp:%s total_channels=%i, active_channels: "
946 		"read=%i, write=%i\n", __func__, action,
947 		fsm_getstate_str(grp->fsm), grp->num_channel_paths,
948 		grp->active_channels[CTCM_READ],
949 		grp->active_channels[CTCM_WRITE]);
950 
951 	if ((action == MPC_CHANNEL_ADD) && (ch->in_mpcgroup == 0)) {
952 		grp->num_channel_paths++;
953 		grp->active_channels[direction]++;
954 		grp->outstanding_xid2++;
955 		ch->in_mpcgroup = 1;
956 
957 		if (ch->xid_skb != NULL)
958 			dev_kfree_skb_any(ch->xid_skb);
959 
960 		ch->xid_skb = __dev_alloc_skb(MPC_BUFSIZE_DEFAULT,
961 					GFP_ATOMIC | GFP_DMA);
962 		if (ch->xid_skb == NULL) {
963 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
964 				"%s(%s): Couldn't alloc ch xid_skb\n",
965 				CTCM_FUNTAIL, dev->name);
966 			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
967 			return;
968 		}
969 		ch->xid_skb_data = ch->xid_skb->data;
970 		ch->xid_th = (struct th_header *)ch->xid_skb->data;
971 		skb_put(ch->xid_skb, TH_HEADER_LENGTH);
972 		ch->xid = (struct xid2 *)skb_tail_pointer(ch->xid_skb);
973 		skb_put(ch->xid_skb, XID2_LENGTH);
974 		ch->xid_id = skb_tail_pointer(ch->xid_skb);
975 		ch->xid_skb->data = ch->xid_skb_data;
976 		skb_reset_tail_pointer(ch->xid_skb);
977 		ch->xid_skb->len = 0;
978 
979 		skb_put_data(ch->xid_skb, grp->xid_skb->data,
980 			     grp->xid_skb->len);
981 
982 		ch->xid->xid2_dlc_type =
983 			((CHANNEL_DIRECTION(ch->flags) == CTCM_READ)
984 				? XID2_READ_SIDE : XID2_WRITE_SIDE);
985 
986 		if (CHANNEL_DIRECTION(ch->flags) == CTCM_WRITE)
987 			ch->xid->xid2_buf_len = 0x00;
988 
989 		ch->xid_skb->data = ch->xid_skb_data;
990 		skb_reset_tail_pointer(ch->xid_skb);
991 		ch->xid_skb->len = 0;
992 
993 		fsm_newstate(ch->fsm, CH_XID0_PENDING);
994 
995 		if ((grp->active_channels[CTCM_READ] > 0) &&
996 		    (grp->active_channels[CTCM_WRITE] > 0) &&
997 			(fsm_getstate(grp->fsm) < MPCG_STATE_XID2INITW)) {
998 			fsm_newstate(grp->fsm, MPCG_STATE_XID2INITW);
999 			CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_NOTICE,
1000 				"%s: %s: MPC GROUP CHANNELS ACTIVE\n",
1001 						__func__, dev->name);
1002 		}
1003 	} else if ((action == MPC_CHANNEL_REMOVE) &&
1004 			(ch->in_mpcgroup == 1)) {
1005 		ch->in_mpcgroup = 0;
1006 		grp->num_channel_paths--;
1007 		grp->active_channels[direction]--;
1008 
1009 		if (ch->xid_skb != NULL)
1010 			dev_kfree_skb_any(ch->xid_skb);
1011 		ch->xid_skb = NULL;
1012 
1013 		if (grp->channels_terminating)
1014 					goto done;
1015 
1016 		if (((grp->active_channels[CTCM_READ] == 0) &&
1017 					(grp->active_channels[CTCM_WRITE] > 0))
1018 			|| ((grp->active_channels[CTCM_WRITE] == 0) &&
1019 					(grp->active_channels[CTCM_READ] > 0)))
1020 			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
1021 	}
1022 done:
1023 	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
1024 		"exit %s: %i / Grp:%s total_channels=%i, active_channels: "
1025 		"read=%i, write=%i\n", __func__, action,
1026 		fsm_getstate_str(grp->fsm), grp->num_channel_paths,
1027 		grp->active_channels[CTCM_READ],
1028 		grp->active_channels[CTCM_WRITE]);
1029 
1030 	CTCM_PR_DEBUG("exit %s: ch=0x%p id=%s\n", __func__, ch, ch->id);
1031 }
1032 
1033 /**
1034  * Unpack a just received skb and hand it over to
1035  * upper layers.
1036  * special MPC version of unpack_skb.
1037  *
1038  * ch		The channel where this skb has been received.
1039  * pskb		The received skb.
1040  */
1041 static void ctcmpc_unpack_skb(struct channel *ch, struct sk_buff *pskb)
1042 {
1043 	struct net_device *dev	= ch->netdev;
1044 	struct ctcm_priv *priv = dev->ml_priv;
1045 	struct mpc_group *grp = priv->mpcg;
1046 	struct pdu *curr_pdu;
1047 	struct mpcg_info *mpcginfo;
1048 	struct th_header *header = NULL;
1049 	struct th_sweep *sweep = NULL;
1050 	int pdu_last_seen = 0;
1051 	__u32 new_len;
1052 	struct sk_buff *skb;
1053 	int skblen;
1054 	int sendrc = 0;
1055 
1056 	CTCM_PR_DEBUG("ctcmpc enter: %s() %s cp:%i ch:%s\n",
1057 			__func__, dev->name, smp_processor_id(), ch->id);
1058 
1059 	header = (struct th_header *)pskb->data;
1060 	if ((header->th_seg == 0) &&
1061 		(header->th_ch_flag == 0) &&
1062 		(header->th_blk_flag == 0) &&
1063 		(header->th_seq_num == 0))
1064 		/* nothing for us */	goto done;
1065 
1066 	CTCM_PR_DBGDATA("%s: th_header\n", __func__);
1067 	CTCM_D3_DUMP((char *)header, TH_HEADER_LENGTH);
1068 	CTCM_PR_DBGDATA("%s: pskb len: %04x \n", __func__, pskb->len);
1069 
1070 	pskb->dev = dev;
1071 	pskb->ip_summed = CHECKSUM_UNNECESSARY;
1072 	skb_pull(pskb, TH_HEADER_LENGTH);
1073 
1074 	if (likely(header->th_ch_flag == TH_HAS_PDU)) {
1075 		CTCM_PR_DBGDATA("%s: came into th_has_pdu\n", __func__);
1076 		if ((fsm_getstate(grp->fsm) == MPCG_STATE_FLOWC) ||
1077 		   ((fsm_getstate(grp->fsm) == MPCG_STATE_READY) &&
1078 		    (header->th_seq_num != ch->th_seq_num + 1) &&
1079 		    (ch->th_seq_num != 0))) {
1080 			/* This is NOT the next segment		*
1081 			 * we are not the correct race winner	*
1082 			 * go away and let someone else win	*
1083 			 * BUT..this only applies if xid negot	*
1084 			 * is done				*
1085 			*/
1086 			grp->out_of_sequence += 1;
1087 			__skb_push(pskb, TH_HEADER_LENGTH);
1088 			skb_queue_tail(&ch->io_queue, pskb);
1089 			CTCM_PR_DBGDATA("%s: th_seq_num expect:%08x "
1090 					"got:%08x\n", __func__,
1091 				ch->th_seq_num + 1, header->th_seq_num);
1092 
1093 			return;
1094 		}
1095 		grp->out_of_sequence = 0;
1096 		ch->th_seq_num = header->th_seq_num;
1097 
1098 		CTCM_PR_DBGDATA("ctcmpc: %s() FromVTAM_th_seq=%08x\n",
1099 					__func__, ch->th_seq_num);
1100 
1101 		if (unlikely(fsm_getstate(grp->fsm) != MPCG_STATE_READY))
1102 					goto done;
1103 		while ((pskb->len > 0) && !pdu_last_seen) {
1104 			curr_pdu = (struct pdu *)pskb->data;
1105 
1106 			CTCM_PR_DBGDATA("%s: pdu_header\n", __func__);
1107 			CTCM_D3_DUMP((char *)pskb->data, PDU_HEADER_LENGTH);
1108 			CTCM_PR_DBGDATA("%s: pskb len: %04x \n",
1109 						__func__, pskb->len);
1110 
1111 			skb_pull(pskb, PDU_HEADER_LENGTH);
1112 
1113 			if (curr_pdu->pdu_flag & PDU_LAST)
1114 				pdu_last_seen = 1;
1115 			if (curr_pdu->pdu_flag & PDU_CNTL)
1116 				pskb->protocol = htons(ETH_P_SNAP);
1117 			else
1118 				pskb->protocol = htons(ETH_P_SNA_DIX);
1119 
1120 			if ((pskb->len <= 0) || (pskb->len > ch->max_bufsize)) {
1121 				CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1122 					"%s(%s): Dropping packet with "
1123 					"illegal siize %d",
1124 					CTCM_FUNTAIL, dev->name, pskb->len);
1125 
1126 				priv->stats.rx_dropped++;
1127 				priv->stats.rx_length_errors++;
1128 					goto done;
1129 			}
1130 			skb_reset_mac_header(pskb);
1131 			new_len = curr_pdu->pdu_offset;
1132 			CTCM_PR_DBGDATA("%s: new_len: %04x \n",
1133 						__func__, new_len);
1134 			if ((new_len == 0) || (new_len > pskb->len)) {
1135 				/* should never happen		    */
1136 				/* pskb len must be hosed...bail out */
1137 				CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1138 					"%s(%s): non valid pdu_offset: %04x",
1139 					/* "data may be lost", */
1140 					CTCM_FUNTAIL, dev->name, new_len);
1141 				goto done;
1142 			}
1143 			skb = __dev_alloc_skb(new_len+4, GFP_ATOMIC);
1144 
1145 			if (!skb) {
1146 				CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1147 					"%s(%s): MEMORY allocation error",
1148 						CTCM_FUNTAIL, dev->name);
1149 				priv->stats.rx_dropped++;
1150 				fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
1151 						goto done;
1152 			}
1153 			skb_put_data(skb, pskb->data, new_len);
1154 
1155 			skb_reset_mac_header(skb);
1156 			skb->dev = pskb->dev;
1157 			skb->protocol = pskb->protocol;
1158 			skb->ip_summed = CHECKSUM_UNNECESSARY;
1159 			*((__u32 *) skb_push(skb, 4)) = ch->pdu_seq;
1160 			ch->pdu_seq++;
1161 
1162 			if (do_debug_data) {
1163 				ctcm_pr_debug("%s: ToDCM_pdu_seq= %08x\n",
1164 						__func__, ch->pdu_seq);
1165 				ctcm_pr_debug("%s: skb:%0lx "
1166 					"skb len: %d \n", __func__,
1167 					(unsigned long)skb, skb->len);
1168 				ctcm_pr_debug("%s: up to 32 bytes "
1169 					"of pdu_data sent\n", __func__);
1170 				ctcmpc_dump32((char *)skb->data, skb->len);
1171 			}
1172 
1173 			skblen = skb->len;
1174 			sendrc = netif_rx(skb);
1175 			priv->stats.rx_packets++;
1176 			priv->stats.rx_bytes += skblen;
1177 			skb_pull(pskb, new_len); /* point to next PDU */
1178 		}
1179 	} else {
1180 		mpcginfo = kmalloc(sizeof(struct mpcg_info), gfp_type());
1181 		if (mpcginfo == NULL)
1182 					goto done;
1183 
1184 		mpcginfo->ch = ch;
1185 		mpcginfo->th = header;
1186 		mpcginfo->skb = pskb;
1187 		CTCM_PR_DEBUG("%s: Not PDU - may be control pkt\n",
1188 					__func__);
1189 		/*  it's a sweep?   */
1190 		sweep = (struct th_sweep *)pskb->data;
1191 		mpcginfo->sweep = sweep;
1192 		if (header->th_ch_flag == TH_SWEEP_REQ)
1193 			mpc_rcvd_sweep_req(mpcginfo);
1194 		else if (header->th_ch_flag == TH_SWEEP_RESP)
1195 			mpc_rcvd_sweep_resp(mpcginfo);
1196 		else if (header->th_blk_flag == TH_DATA_IS_XID) {
1197 			struct xid2 *thisxid = (struct xid2 *)pskb->data;
1198 			skb_pull(pskb, XID2_LENGTH);
1199 			mpcginfo->xid = thisxid;
1200 			fsm_event(grp->fsm, MPCG_EVENT_XID2, mpcginfo);
1201 		} else if (header->th_blk_flag == TH_DISCONTACT)
1202 			fsm_event(grp->fsm, MPCG_EVENT_DISCONC, mpcginfo);
1203 		else if (header->th_seq_num != 0) {
1204 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1205 				"%s(%s): control pkt expected\n",
1206 						CTCM_FUNTAIL, dev->name);
1207 			priv->stats.rx_dropped++;
1208 			/* mpcginfo only used for non-data transfers */
1209 			kfree(mpcginfo);
1210 			if (do_debug_data)
1211 				ctcmpc_dump_skb(pskb, -8);
1212 		}
1213 	}
1214 done:
1215 
1216 	dev_kfree_skb_any(pskb);
1217 	if (sendrc == NET_RX_DROP) {
1218 		dev_warn(&dev->dev,
1219 			"The network backlog for %s is exceeded, "
1220 			"package dropped\n", __func__);
1221 		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
1222 	}
1223 
1224 	CTCM_PR_DEBUG("exit %s: %s: ch=0x%p id=%s\n",
1225 			__func__, dev->name, ch, ch->id);
1226 }
1227 
1228 /**
1229  * tasklet helper for mpc's skb unpacking.
1230  *
1231  * ch		The channel to work on.
1232  * Allow flow control back pressure to occur here.
1233  * Throttling back channel can result in excessive
1234  * channel inactivity and system deact of channel
1235  */
1236 void ctcmpc_bh(unsigned long thischan)
1237 {
1238 	struct channel	  *ch	= (struct channel *)thischan;
1239 	struct sk_buff	  *skb;
1240 	struct net_device *dev	= ch->netdev;
1241 	struct ctcm_priv  *priv	= dev->ml_priv;
1242 	struct mpc_group  *grp	= priv->mpcg;
1243 
1244 	CTCM_PR_DEBUG("%s cp:%i enter:  %s() %s\n",
1245 	       dev->name, smp_processor_id(), __func__, ch->id);
1246 	/* caller has requested driver to throttle back */
1247 	while ((fsm_getstate(grp->fsm) != MPCG_STATE_FLOWC) &&
1248 			(skb = skb_dequeue(&ch->io_queue))) {
1249 		ctcmpc_unpack_skb(ch, skb);
1250 		if (grp->out_of_sequence > 20) {
1251 			/* assume data loss has occurred if */
1252 			/* missing seq_num for extended     */
1253 			/* period of time		    */
1254 			grp->out_of_sequence = 0;
1255 			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
1256 			break;
1257 		}
1258 		if (skb == skb_peek(&ch->io_queue))
1259 			break;
1260 	}
1261 	CTCM_PR_DEBUG("exit %s: %s: ch=0x%p id=%s\n",
1262 			__func__, dev->name, ch, ch->id);
1263 	return;
1264 }
1265 
1266 /*
1267  *  MPC Group Initializations
1268  */
1269 struct mpc_group *ctcmpc_init_mpc_group(struct ctcm_priv *priv)
1270 {
1271 	struct mpc_group *grp;
1272 
1273 	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_INFO,
1274 			"Enter %s(%p)", CTCM_FUNTAIL, priv);
1275 
1276 	grp = kzalloc(sizeof(struct mpc_group), GFP_KERNEL);
1277 	if (grp == NULL)
1278 		return NULL;
1279 
1280 	grp->fsm = init_fsm("mpcg", mpcg_state_names, mpcg_event_names,
1281 			MPCG_NR_STATES, MPCG_NR_EVENTS, mpcg_fsm,
1282 			mpcg_fsm_len, GFP_KERNEL);
1283 	if (grp->fsm == NULL) {
1284 		kfree(grp);
1285 		return NULL;
1286 	}
1287 
1288 	fsm_newstate(grp->fsm, MPCG_STATE_RESET);
1289 	fsm_settimer(grp->fsm, &grp->timer);
1290 
1291 	grp->xid_skb =
1292 		 __dev_alloc_skb(MPC_BUFSIZE_DEFAULT, GFP_ATOMIC | GFP_DMA);
1293 	if (grp->xid_skb == NULL) {
1294 		kfree_fsm(grp->fsm);
1295 		kfree(grp);
1296 		return NULL;
1297 	}
1298 	/*  base xid for all channels in group  */
1299 	grp->xid_skb_data = grp->xid_skb->data;
1300 	grp->xid_th = (struct th_header *)grp->xid_skb->data;
1301 	skb_put_data(grp->xid_skb, &thnorm, TH_HEADER_LENGTH);
1302 
1303 	grp->xid = (struct xid2 *)skb_tail_pointer(grp->xid_skb);
1304 	skb_put_data(grp->xid_skb, &init_xid, XID2_LENGTH);
1305 	grp->xid->xid2_adj_id = jiffies | 0xfff00000;
1306 	grp->xid->xid2_sender_id = jiffies;
1307 
1308 	grp->xid_id = skb_tail_pointer(grp->xid_skb);
1309 	skb_put_data(grp->xid_skb, "VTAM", 4);
1310 
1311 	grp->rcvd_xid_skb =
1312 		__dev_alloc_skb(MPC_BUFSIZE_DEFAULT, GFP_ATOMIC|GFP_DMA);
1313 	if (grp->rcvd_xid_skb == NULL) {
1314 		kfree_fsm(grp->fsm);
1315 		dev_kfree_skb(grp->xid_skb);
1316 		kfree(grp);
1317 		return NULL;
1318 	}
1319 	grp->rcvd_xid_data = grp->rcvd_xid_skb->data;
1320 	grp->rcvd_xid_th = (struct th_header *)grp->rcvd_xid_skb->data;
1321 	skb_put_data(grp->rcvd_xid_skb, &thnorm, TH_HEADER_LENGTH);
1322 	grp->saved_xid2 = NULL;
1323 	priv->xid = grp->xid;
1324 	priv->mpcg = grp;
1325 	return grp;
1326 }
1327 
1328 /*
1329  * The MPC Group Station FSM
1330  */
1331 
1332 /*
1333  * MPC Group Station FSM actions
1334  * CTCM_PROTO_MPC only
1335  */
1336 
1337 /**
1338  * NOP action for statemachines
1339  */
1340 static void mpc_action_nop(fsm_instance *fi, int event, void *arg)
1341 {
1342 }
1343 
1344 /*
1345  * invoked when the device transitions to dev_stopped
1346  * MPC will stop each individual channel if a single XID failure
1347  * occurs, or will intitiate all channels be stopped if a GROUP
1348  * level failure occurs.
1349  */
1350 static void mpc_action_go_inop(fsm_instance *fi, int event, void *arg)
1351 {
1352 	struct net_device  *dev = arg;
1353 	struct ctcm_priv    *priv;
1354 	struct mpc_group *grp;
1355 	struct channel *wch;
1356 
1357 	CTCM_PR_DEBUG("Enter %s: %s\n",	__func__, dev->name);
1358 
1359 	priv  = dev->ml_priv;
1360 	grp =  priv->mpcg;
1361 	grp->flow_off_called = 0;
1362 	fsm_deltimer(&grp->timer);
1363 	if (grp->channels_terminating)
1364 			return;
1365 
1366 	grp->channels_terminating = 1;
1367 	grp->saved_state = fsm_getstate(grp->fsm);
1368 	fsm_newstate(grp->fsm, MPCG_STATE_INOP);
1369 	if (grp->saved_state > MPCG_STATE_XID7INITF)
1370 		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
1371 			"%s(%s): MPC GROUP INOPERATIVE",
1372 				CTCM_FUNTAIL, dev->name);
1373 	if ((grp->saved_state != MPCG_STATE_RESET) ||
1374 		/* dealloc_channel has been called */
1375 		(grp->port_persist == 0))
1376 		fsm_deltimer(&priv->restart_timer);
1377 
1378 	wch = priv->channel[CTCM_WRITE];
1379 
1380 	switch (grp->saved_state) {
1381 	case MPCG_STATE_RESET:
1382 	case MPCG_STATE_INOP:
1383 	case MPCG_STATE_XID2INITW:
1384 	case MPCG_STATE_XID0IOWAIT:
1385 	case MPCG_STATE_XID2INITX:
1386 	case MPCG_STATE_XID7INITW:
1387 	case MPCG_STATE_XID7INITX:
1388 	case MPCG_STATE_XID0IOWAIX:
1389 	case MPCG_STATE_XID7INITI:
1390 	case MPCG_STATE_XID7INITZ:
1391 	case MPCG_STATE_XID7INITF:
1392 		break;
1393 	case MPCG_STATE_FLOWC:
1394 	case MPCG_STATE_READY:
1395 	default:
1396 		tasklet_hi_schedule(&wch->ch_disc_tasklet);
1397 	}
1398 
1399 	grp->xid2_tgnum = 0;
1400 	grp->group_max_buflen = 0;  /*min of all received */
1401 	grp->outstanding_xid2 = 0;
1402 	grp->outstanding_xid7 = 0;
1403 	grp->outstanding_xid7_p2 = 0;
1404 	grp->saved_xid2 = NULL;
1405 	grp->xidnogood = 0;
1406 	grp->changed_side = 0;
1407 
1408 	grp->rcvd_xid_skb->data = grp->rcvd_xid_data;
1409 	skb_reset_tail_pointer(grp->rcvd_xid_skb);
1410 	grp->rcvd_xid_skb->len = 0;
1411 	grp->rcvd_xid_th = (struct th_header *)grp->rcvd_xid_skb->data;
1412 	skb_put_data(grp->rcvd_xid_skb, &thnorm, TH_HEADER_LENGTH);
1413 
1414 	if (grp->send_qllc_disc == 1) {
1415 		grp->send_qllc_disc = 0;
1416 		mpc_send_qllc_discontact(dev);
1417 	}
1418 
1419 	/* DO NOT issue DEV_EVENT_STOP directly out of this code */
1420 	/* This can result in INOP of VTAM PU due to halting of  */
1421 	/* outstanding IO which causes a sense to be returned	 */
1422 	/* Only about 3 senses are allowed and then IOS/VTAM will*/
1423 	/* become unreachable without manual intervention	 */
1424 	if ((grp->port_persist == 1) || (grp->alloc_called)) {
1425 		grp->alloc_called = 0;
1426 		fsm_deltimer(&priv->restart_timer);
1427 		fsm_addtimer(&priv->restart_timer, 500, DEV_EVENT_RESTART, dev);
1428 		fsm_newstate(grp->fsm, MPCG_STATE_RESET);
1429 		if (grp->saved_state > MPCG_STATE_XID7INITF)
1430 			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ALWAYS,
1431 				"%s(%s): MPC GROUP RECOVERY SCHEDULED",
1432 					CTCM_FUNTAIL, dev->name);
1433 	} else {
1434 		fsm_deltimer(&priv->restart_timer);
1435 		fsm_addtimer(&priv->restart_timer, 500, DEV_EVENT_STOP, dev);
1436 		fsm_newstate(grp->fsm, MPCG_STATE_RESET);
1437 		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ALWAYS,
1438 			"%s(%s): NO MPC GROUP RECOVERY ATTEMPTED",
1439 						CTCM_FUNTAIL, dev->name);
1440 	}
1441 }
1442 
1443 /**
1444  * Handle mpc group  action timeout.
1445  * MPC Group Station FSM action
1446  * CTCM_PROTO_MPC only
1447  *
1448  * fi		An instance of an mpc_group fsm.
1449  * event	The event, just happened.
1450  * arg		Generic pointer, casted from net_device * upon call.
1451  */
1452 static void mpc_action_timeout(fsm_instance *fi, int event, void *arg)
1453 {
1454 	struct net_device *dev = arg;
1455 	struct ctcm_priv *priv;
1456 	struct mpc_group *grp;
1457 	struct channel *wch;
1458 	struct channel *rch;
1459 
1460 	priv = dev->ml_priv;
1461 	grp = priv->mpcg;
1462 	wch = priv->channel[CTCM_WRITE];
1463 	rch = priv->channel[CTCM_READ];
1464 
1465 	switch (fsm_getstate(grp->fsm)) {
1466 	case MPCG_STATE_XID2INITW:
1467 		/* Unless there is outstanding IO on the  */
1468 		/* channel just return and wait for ATTN  */
1469 		/* interrupt to begin XID negotiations	  */
1470 		if ((fsm_getstate(rch->fsm) == CH_XID0_PENDING) &&
1471 		   (fsm_getstate(wch->fsm) == CH_XID0_PENDING))
1472 			break;
1473 		fallthrough;
1474 	default:
1475 		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
1476 	}
1477 
1478 	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
1479 			"%s: dev=%s exit",
1480 			CTCM_FUNTAIL, dev->name);
1481 	return;
1482 }
1483 
1484 /*
1485  * MPC Group Station FSM action
1486  * CTCM_PROTO_MPC only
1487  */
1488 void mpc_action_discontact(fsm_instance *fi, int event, void *arg)
1489 {
1490 	struct mpcg_info   *mpcginfo   = arg;
1491 	struct channel	   *ch	       = mpcginfo->ch;
1492 	struct net_device  *dev;
1493 	struct ctcm_priv   *priv;
1494 	struct mpc_group   *grp;
1495 
1496 	if (ch) {
1497 		dev = ch->netdev;
1498 		if (dev) {
1499 			priv = dev->ml_priv;
1500 			if (priv) {
1501 				CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
1502 					"%s: %s: %s\n",
1503 					CTCM_FUNTAIL, dev->name, ch->id);
1504 				grp = priv->mpcg;
1505 				grp->send_qllc_disc = 1;
1506 				fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
1507 			}
1508 		}
1509 	}
1510 
1511 	return;
1512 }
1513 
1514 /*
1515  * MPC Group Station - not part of FSM
1516  * CTCM_PROTO_MPC only
1517  * called from add_channel in ctcm_main.c
1518  */
1519 void mpc_action_send_discontact(unsigned long thischan)
1520 {
1521 	int rc;
1522 	struct channel	*ch = (struct channel *)thischan;
1523 	unsigned long	saveflags = 0;
1524 
1525 	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
1526 	rc = ccw_device_start(ch->cdev, &ch->ccw[15], 0, 0xff, 0);
1527 	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
1528 
1529 	if (rc != 0) {
1530 		ctcm_ccw_check_rc(ch, rc, (char *)__func__);
1531 	}
1532 
1533 	return;
1534 }
1535 
1536 
1537 /*
1538  * helper function of mpc FSM
1539  * CTCM_PROTO_MPC only
1540  * mpc_action_rcvd_xid7
1541 */
1542 static int mpc_validate_xid(struct mpcg_info *mpcginfo)
1543 {
1544 	struct channel	   *ch	 = mpcginfo->ch;
1545 	struct net_device  *dev  = ch->netdev;
1546 	struct ctcm_priv   *priv = dev->ml_priv;
1547 	struct mpc_group   *grp  = priv->mpcg;
1548 	struct xid2	   *xid  = mpcginfo->xid;
1549 	int	rc	 = 0;
1550 	__u64	our_id   = 0;
1551 	__u64   their_id = 0;
1552 	int	len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
1553 
1554 	CTCM_PR_DEBUG("Enter %s: xid=%p\n", __func__, xid);
1555 
1556 	if (xid == NULL) {
1557 		rc = 1;
1558 		/* XID REJECTED: xid == NULL */
1559 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1560 			"%s(%s): xid = NULL",
1561 				CTCM_FUNTAIL, ch->id);
1562 			goto done;
1563 	}
1564 
1565 	CTCM_D3_DUMP((char *)xid, XID2_LENGTH);
1566 
1567 	/*the received direction should be the opposite of ours  */
1568 	if (((CHANNEL_DIRECTION(ch->flags) == CTCM_READ) ? XID2_WRITE_SIDE :
1569 				XID2_READ_SIDE) != xid->xid2_dlc_type) {
1570 		rc = 2;
1571 		/* XID REJECTED: r/w channel pairing mismatch */
1572 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1573 			"%s(%s): r/w channel pairing mismatch",
1574 				CTCM_FUNTAIL, ch->id);
1575 			goto done;
1576 	}
1577 
1578 	if (xid->xid2_dlc_type == XID2_READ_SIDE) {
1579 		CTCM_PR_DEBUG("%s: grpmaxbuf:%d xid2buflen:%d\n", __func__,
1580 				grp->group_max_buflen, xid->xid2_buf_len);
1581 
1582 		if (grp->group_max_buflen == 0 || grp->group_max_buflen >
1583 						xid->xid2_buf_len - len)
1584 			grp->group_max_buflen = xid->xid2_buf_len - len;
1585 	}
1586 
1587 	if (grp->saved_xid2 == NULL) {
1588 		grp->saved_xid2 =
1589 			(struct xid2 *)skb_tail_pointer(grp->rcvd_xid_skb);
1590 
1591 		skb_put_data(grp->rcvd_xid_skb, xid, XID2_LENGTH);
1592 		grp->rcvd_xid_skb->data = grp->rcvd_xid_data;
1593 
1594 		skb_reset_tail_pointer(grp->rcvd_xid_skb);
1595 		grp->rcvd_xid_skb->len = 0;
1596 
1597 		/* convert two 32 bit numbers into 1 64 bit for id compare */
1598 		our_id = (__u64)priv->xid->xid2_adj_id;
1599 		our_id = our_id << 32;
1600 		our_id = our_id + priv->xid->xid2_sender_id;
1601 		their_id = (__u64)xid->xid2_adj_id;
1602 		their_id = their_id << 32;
1603 		their_id = their_id + xid->xid2_sender_id;
1604 		/* lower id assume the xside role */
1605 		if (our_id < their_id) {
1606 			grp->roll = XSIDE;
1607 			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
1608 				"%s(%s): WE HAVE LOW ID - TAKE XSIDE",
1609 					CTCM_FUNTAIL, ch->id);
1610 		} else {
1611 			grp->roll = YSIDE;
1612 			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
1613 				"%s(%s): WE HAVE HIGH ID - TAKE YSIDE",
1614 					CTCM_FUNTAIL, ch->id);
1615 		}
1616 
1617 	} else {
1618 		if (xid->xid2_flag4 != grp->saved_xid2->xid2_flag4) {
1619 			rc = 3;
1620 			/* XID REJECTED: xid flag byte4 mismatch */
1621 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1622 				"%s(%s): xid flag byte4 mismatch",
1623 					CTCM_FUNTAIL, ch->id);
1624 		}
1625 		if (xid->xid2_flag2 == 0x40) {
1626 			rc = 4;
1627 			/* XID REJECTED - xid NOGOOD */
1628 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1629 				"%s(%s): xid NOGOOD",
1630 					CTCM_FUNTAIL, ch->id);
1631 		}
1632 		if (xid->xid2_adj_id != grp->saved_xid2->xid2_adj_id) {
1633 			rc = 5;
1634 			/* XID REJECTED - Adjacent Station ID Mismatch */
1635 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1636 				"%s(%s): Adjacent Station ID Mismatch",
1637 					CTCM_FUNTAIL, ch->id);
1638 		}
1639 		if (xid->xid2_sender_id != grp->saved_xid2->xid2_sender_id) {
1640 			rc = 6;
1641 			/* XID REJECTED - Sender Address Mismatch */
1642 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1643 				"%s(%s): Sender Address Mismatch",
1644 					CTCM_FUNTAIL, ch->id);
1645 		}
1646 	}
1647 done:
1648 	if (rc) {
1649 		dev_warn(&dev->dev,
1650 			"The XID used in the MPC protocol is not valid, "
1651 			"rc = %d\n", rc);
1652 		priv->xid->xid2_flag2 = 0x40;
1653 		grp->saved_xid2->xid2_flag2 = 0x40;
1654 	}
1655 
1656 	return rc;
1657 }
1658 
1659 /*
1660  * MPC Group Station FSM action
1661  * CTCM_PROTO_MPC only
1662  */
1663 static void mpc_action_side_xid(fsm_instance *fsm, void *arg, int side)
1664 {
1665 	struct channel *ch = arg;
1666 	int rc = 0;
1667 	int gotlock = 0;
1668 	unsigned long saveflags = 0;	/* avoids compiler warning with
1669 					   spin_unlock_irqrestore */
1670 
1671 	CTCM_PR_DEBUG("Enter %s: cp=%i ch=0x%p id=%s\n",
1672 			__func__, smp_processor_id(), ch, ch->id);
1673 
1674 	if (ctcm_checkalloc_buffer(ch))
1675 					goto done;
1676 
1677 	/*
1678 	 * skb data-buffer referencing:
1679 	 */
1680 	ch->trans_skb->data = ch->trans_skb_data;
1681 	skb_reset_tail_pointer(ch->trans_skb);
1682 	ch->trans_skb->len = 0;
1683 	/* result of the previous 3 statements is NOT always
1684 	 * already set after ctcm_checkalloc_buffer
1685 	 * because of possible reuse of the trans_skb
1686 	 */
1687 	memset(ch->trans_skb->data, 0, 16);
1688 	ch->rcvd_xid_th =  (struct th_header *)ch->trans_skb_data;
1689 	/* check is main purpose here: */
1690 	skb_put(ch->trans_skb, TH_HEADER_LENGTH);
1691 	ch->rcvd_xid = (struct xid2 *)skb_tail_pointer(ch->trans_skb);
1692 	/* check is main purpose here: */
1693 	skb_put(ch->trans_skb, XID2_LENGTH);
1694 	ch->rcvd_xid_id = skb_tail_pointer(ch->trans_skb);
1695 	/* cleanup back to startpoint */
1696 	ch->trans_skb->data = ch->trans_skb_data;
1697 	skb_reset_tail_pointer(ch->trans_skb);
1698 	ch->trans_skb->len = 0;
1699 
1700 	/* non-checking rewrite of above skb data-buffer referencing: */
1701 	/*
1702 	memset(ch->trans_skb->data, 0, 16);
1703 	ch->rcvd_xid_th =  (struct th_header *)ch->trans_skb_data;
1704 	ch->rcvd_xid = (struct xid2 *)(ch->trans_skb_data + TH_HEADER_LENGTH);
1705 	ch->rcvd_xid_id = ch->trans_skb_data + TH_HEADER_LENGTH + XID2_LENGTH;
1706 	 */
1707 
1708 	ch->ccw[8].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1709 	ch->ccw[8].count	= 0;
1710 	ch->ccw[8].cda		= 0x00;
1711 
1712 	if (!(ch->xid_th && ch->xid && ch->xid_id))
1713 		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_INFO,
1714 			"%s(%s): xid_th=%p, xid=%p, xid_id=%p",
1715 			CTCM_FUNTAIL, ch->id, ch->xid_th, ch->xid, ch->xid_id);
1716 
1717 	if (side == XSIDE) {
1718 		/* mpc_action_xside_xid */
1719 		if (ch->xid_th == NULL)
1720 				goto done;
1721 		ch->ccw[9].cmd_code	= CCW_CMD_WRITE;
1722 		ch->ccw[9].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1723 		ch->ccw[9].count	= TH_HEADER_LENGTH;
1724 		ch->ccw[9].cda		= virt_to_phys(ch->xid_th);
1725 
1726 		if (ch->xid == NULL)
1727 				goto done;
1728 		ch->ccw[10].cmd_code	= CCW_CMD_WRITE;
1729 		ch->ccw[10].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1730 		ch->ccw[10].count	= XID2_LENGTH;
1731 		ch->ccw[10].cda		= virt_to_phys(ch->xid);
1732 
1733 		ch->ccw[11].cmd_code	= CCW_CMD_READ;
1734 		ch->ccw[11].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1735 		ch->ccw[11].count	= TH_HEADER_LENGTH;
1736 		ch->ccw[11].cda		= virt_to_phys(ch->rcvd_xid_th);
1737 
1738 		ch->ccw[12].cmd_code	= CCW_CMD_READ;
1739 		ch->ccw[12].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1740 		ch->ccw[12].count	= XID2_LENGTH;
1741 		ch->ccw[12].cda		= virt_to_phys(ch->rcvd_xid);
1742 
1743 		ch->ccw[13].cmd_code	= CCW_CMD_READ;
1744 		ch->ccw[13].cda		= virt_to_phys(ch->rcvd_xid_id);
1745 
1746 	} else { /* side == YSIDE : mpc_action_yside_xid */
1747 		ch->ccw[9].cmd_code	= CCW_CMD_READ;
1748 		ch->ccw[9].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1749 		ch->ccw[9].count	= TH_HEADER_LENGTH;
1750 		ch->ccw[9].cda		= virt_to_phys(ch->rcvd_xid_th);
1751 
1752 		ch->ccw[10].cmd_code	= CCW_CMD_READ;
1753 		ch->ccw[10].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1754 		ch->ccw[10].count	= XID2_LENGTH;
1755 		ch->ccw[10].cda		= virt_to_phys(ch->rcvd_xid);
1756 
1757 		if (ch->xid_th == NULL)
1758 				goto done;
1759 		ch->ccw[11].cmd_code	= CCW_CMD_WRITE;
1760 		ch->ccw[11].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1761 		ch->ccw[11].count	= TH_HEADER_LENGTH;
1762 		ch->ccw[11].cda		= virt_to_phys(ch->xid_th);
1763 
1764 		if (ch->xid == NULL)
1765 				goto done;
1766 		ch->ccw[12].cmd_code	= CCW_CMD_WRITE;
1767 		ch->ccw[12].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1768 		ch->ccw[12].count	= XID2_LENGTH;
1769 		ch->ccw[12].cda		= virt_to_phys(ch->xid);
1770 
1771 		if (ch->xid_id == NULL)
1772 				goto done;
1773 		ch->ccw[13].cmd_code	= CCW_CMD_WRITE;
1774 		ch->ccw[13].cda		= virt_to_phys(ch->xid_id);
1775 
1776 	}
1777 	ch->ccw[13].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
1778 	ch->ccw[13].count	= 4;
1779 
1780 	ch->ccw[14].cmd_code	= CCW_CMD_NOOP;
1781 	ch->ccw[14].flags	= CCW_FLAG_SLI;
1782 	ch->ccw[14].count	= 0;
1783 	ch->ccw[14].cda		= 0;
1784 
1785 	CTCM_CCW_DUMP((char *)&ch->ccw[8], sizeof(struct ccw1) * 7);
1786 	CTCM_D3_DUMP((char *)ch->xid_th, TH_HEADER_LENGTH);
1787 	CTCM_D3_DUMP((char *)ch->xid, XID2_LENGTH);
1788 	CTCM_D3_DUMP((char *)ch->xid_id, 4);
1789 
1790 	if (!in_irq()) {
1791 			 /* Such conditional locking is a known problem for
1792 			  * sparse because its static undeterministic.
1793 			  * Warnings should be ignored here. */
1794 		spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
1795 		gotlock = 1;
1796 	}
1797 
1798 	fsm_addtimer(&ch->timer, 5000 , CTC_EVENT_TIMER, ch);
1799 	rc = ccw_device_start(ch->cdev, &ch->ccw[8], 0, 0xff, 0);
1800 
1801 	if (gotlock)	/* see remark above about conditional locking */
1802 		spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
1803 
1804 	if (rc != 0) {
1805 		ctcm_ccw_check_rc(ch, rc,
1806 				(side == XSIDE) ? "x-side XID" : "y-side XID");
1807 	}
1808 
1809 done:
1810 	CTCM_PR_DEBUG("Exit %s: ch=0x%p id=%s\n",
1811 				__func__, ch, ch->id);
1812 	return;
1813 
1814 }
1815 
1816 /*
1817  * MPC Group Station FSM action
1818  * CTCM_PROTO_MPC only
1819  */
1820 static void mpc_action_xside_xid(fsm_instance *fsm, int event, void *arg)
1821 {
1822 	mpc_action_side_xid(fsm, arg, XSIDE);
1823 }
1824 
1825 /*
1826  * MPC Group Station FSM action
1827  * CTCM_PROTO_MPC only
1828  */
1829 static void mpc_action_yside_xid(fsm_instance *fsm, int event, void *arg)
1830 {
1831 	mpc_action_side_xid(fsm, arg, YSIDE);
1832 }
1833 
1834 /*
1835  * MPC Group Station FSM action
1836  * CTCM_PROTO_MPC only
1837  */
1838 static void mpc_action_doxid0(fsm_instance *fsm, int event, void *arg)
1839 {
1840 	struct channel	   *ch   = arg;
1841 	struct net_device  *dev  = ch->netdev;
1842 	struct ctcm_priv   *priv = dev->ml_priv;
1843 	struct mpc_group   *grp  = priv->mpcg;
1844 
1845 	CTCM_PR_DEBUG("Enter %s: cp=%i ch=0x%p id=%s\n",
1846 			__func__, smp_processor_id(), ch, ch->id);
1847 
1848 	if (ch->xid == NULL) {
1849 		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
1850 			"%s(%s): ch->xid == NULL",
1851 				CTCM_FUNTAIL, dev->name);
1852 		return;
1853 	}
1854 
1855 	fsm_newstate(ch->fsm, CH_XID0_INPROGRESS);
1856 
1857 	ch->xid->xid2_option =	XID2_0;
1858 
1859 	switch (fsm_getstate(grp->fsm)) {
1860 	case MPCG_STATE_XID2INITW:
1861 	case MPCG_STATE_XID2INITX:
1862 		ch->ccw[8].cmd_code = CCW_CMD_SENSE_CMD;
1863 		break;
1864 	case MPCG_STATE_XID0IOWAIT:
1865 	case MPCG_STATE_XID0IOWAIX:
1866 		ch->ccw[8].cmd_code = CCW_CMD_WRITE_CTL;
1867 		break;
1868 	}
1869 
1870 	fsm_event(grp->fsm, MPCG_EVENT_DOIO, ch);
1871 
1872 	return;
1873 }
1874 
1875 /*
1876  * MPC Group Station FSM action
1877  * CTCM_PROTO_MPC only
1878 */
1879 static void mpc_action_doxid7(fsm_instance *fsm, int event, void *arg)
1880 {
1881 	struct net_device *dev = arg;
1882 	struct ctcm_priv  *priv = dev->ml_priv;
1883 	struct mpc_group  *grp  = NULL;
1884 	int direction;
1885 	int send = 0;
1886 
1887 	if (priv)
1888 		grp = priv->mpcg;
1889 	if (grp == NULL)
1890 		return;
1891 
1892 	for (direction = CTCM_READ; direction <= CTCM_WRITE; direction++) {
1893 		struct channel *ch = priv->channel[direction];
1894 		struct xid2 *thisxid = ch->xid;
1895 		ch->xid_skb->data = ch->xid_skb_data;
1896 		skb_reset_tail_pointer(ch->xid_skb);
1897 		ch->xid_skb->len = 0;
1898 		thisxid->xid2_option = XID2_7;
1899 		send = 0;
1900 
1901 		/* xid7 phase 1 */
1902 		if (grp->outstanding_xid7_p2 > 0) {
1903 			if (grp->roll == YSIDE) {
1904 				if (fsm_getstate(ch->fsm) == CH_XID7_PENDING1) {
1905 					fsm_newstate(ch->fsm, CH_XID7_PENDING2);
1906 					ch->ccw[8].cmd_code = CCW_CMD_SENSE_CMD;
1907 					skb_put_data(ch->xid_skb, &thdummy,
1908 						     TH_HEADER_LENGTH);
1909 					send = 1;
1910 				}
1911 			} else if (fsm_getstate(ch->fsm) < CH_XID7_PENDING2) {
1912 					fsm_newstate(ch->fsm, CH_XID7_PENDING2);
1913 					ch->ccw[8].cmd_code = CCW_CMD_WRITE_CTL;
1914 					skb_put_data(ch->xid_skb, &thnorm,
1915 						     TH_HEADER_LENGTH);
1916 					send = 1;
1917 			}
1918 		} else {
1919 			/* xid7 phase 2 */
1920 			if (grp->roll == YSIDE) {
1921 				if (fsm_getstate(ch->fsm) < CH_XID7_PENDING4) {
1922 					fsm_newstate(ch->fsm, CH_XID7_PENDING4);
1923 					skb_put_data(ch->xid_skb, &thnorm,
1924 						     TH_HEADER_LENGTH);
1925 					ch->ccw[8].cmd_code = CCW_CMD_WRITE_CTL;
1926 					send = 1;
1927 				}
1928 			} else if (fsm_getstate(ch->fsm) == CH_XID7_PENDING3) {
1929 				fsm_newstate(ch->fsm, CH_XID7_PENDING4);
1930 				ch->ccw[8].cmd_code = CCW_CMD_SENSE_CMD;
1931 				skb_put_data(ch->xid_skb, &thdummy,
1932 					     TH_HEADER_LENGTH);
1933 				send = 1;
1934 			}
1935 		}
1936 
1937 		if (send)
1938 			fsm_event(grp->fsm, MPCG_EVENT_DOIO, ch);
1939 	}
1940 
1941 	return;
1942 }
1943 
1944 /*
1945  * MPC Group Station FSM action
1946  * CTCM_PROTO_MPC only
1947  */
1948 static void mpc_action_rcvd_xid0(fsm_instance *fsm, int event, void *arg)
1949 {
1950 
1951 	struct mpcg_info   *mpcginfo  = arg;
1952 	struct channel	   *ch   = mpcginfo->ch;
1953 	struct net_device  *dev  = ch->netdev;
1954 	struct ctcm_priv   *priv = dev->ml_priv;
1955 	struct mpc_group   *grp  = priv->mpcg;
1956 
1957 	CTCM_PR_DEBUG("%s: ch-id:%s xid2:%i xid7:%i xidt_p2:%i \n",
1958 			__func__, ch->id, grp->outstanding_xid2,
1959 			grp->outstanding_xid7, grp->outstanding_xid7_p2);
1960 
1961 	if (fsm_getstate(ch->fsm) < CH_XID7_PENDING)
1962 		fsm_newstate(ch->fsm, CH_XID7_PENDING);
1963 
1964 	grp->outstanding_xid2--;
1965 	grp->outstanding_xid7++;
1966 	grp->outstanding_xid7_p2++;
1967 
1968 	/* must change state before validating xid to */
1969 	/* properly handle interim interrupts received*/
1970 	switch (fsm_getstate(grp->fsm)) {
1971 	case MPCG_STATE_XID2INITW:
1972 		fsm_newstate(grp->fsm, MPCG_STATE_XID2INITX);
1973 		mpc_validate_xid(mpcginfo);
1974 		break;
1975 	case MPCG_STATE_XID0IOWAIT:
1976 		fsm_newstate(grp->fsm, MPCG_STATE_XID0IOWAIX);
1977 		mpc_validate_xid(mpcginfo);
1978 		break;
1979 	case MPCG_STATE_XID2INITX:
1980 		if (grp->outstanding_xid2 == 0) {
1981 			fsm_newstate(grp->fsm, MPCG_STATE_XID7INITW);
1982 			mpc_validate_xid(mpcginfo);
1983 			fsm_event(grp->fsm, MPCG_EVENT_XID2DONE, dev);
1984 		}
1985 		break;
1986 	case MPCG_STATE_XID0IOWAIX:
1987 		if (grp->outstanding_xid2 == 0) {
1988 			fsm_newstate(grp->fsm, MPCG_STATE_XID7INITI);
1989 			mpc_validate_xid(mpcginfo);
1990 			fsm_event(grp->fsm, MPCG_EVENT_XID2DONE, dev);
1991 		}
1992 		break;
1993 	}
1994 	kfree(mpcginfo);
1995 
1996 	CTCM_PR_DEBUG("ctcmpc:%s() %s xid2:%i xid7:%i xidt_p2:%i \n",
1997 		__func__, ch->id, grp->outstanding_xid2,
1998 		grp->outstanding_xid7, grp->outstanding_xid7_p2);
1999 	CTCM_PR_DEBUG("ctcmpc:%s() %s grpstate: %s chanstate: %s \n",
2000 		__func__, ch->id,
2001 		fsm_getstate_str(grp->fsm), fsm_getstate_str(ch->fsm));
2002 	return;
2003 
2004 }
2005 
2006 
2007 /*
2008  * MPC Group Station FSM action
2009  * CTCM_PROTO_MPC only
2010  */
2011 static void mpc_action_rcvd_xid7(fsm_instance *fsm, int event, void *arg)
2012 {
2013 	struct mpcg_info   *mpcginfo   = arg;
2014 	struct channel	   *ch	       = mpcginfo->ch;
2015 	struct net_device  *dev        = ch->netdev;
2016 	struct ctcm_priv   *priv    = dev->ml_priv;
2017 	struct mpc_group   *grp     = priv->mpcg;
2018 
2019 	CTCM_PR_DEBUG("Enter %s: cp=%i ch=0x%p id=%s\n",
2020 		__func__, smp_processor_id(), ch, ch->id);
2021 	CTCM_PR_DEBUG("%s: outstanding_xid7: %i, outstanding_xid7_p2: %i\n",
2022 		__func__, grp->outstanding_xid7, grp->outstanding_xid7_p2);
2023 
2024 	grp->outstanding_xid7--;
2025 	ch->xid_skb->data = ch->xid_skb_data;
2026 	skb_reset_tail_pointer(ch->xid_skb);
2027 	ch->xid_skb->len = 0;
2028 
2029 	switch (fsm_getstate(grp->fsm)) {
2030 	case MPCG_STATE_XID7INITI:
2031 		fsm_newstate(grp->fsm, MPCG_STATE_XID7INITZ);
2032 		mpc_validate_xid(mpcginfo);
2033 		break;
2034 	case MPCG_STATE_XID7INITW:
2035 		fsm_newstate(grp->fsm, MPCG_STATE_XID7INITX);
2036 		mpc_validate_xid(mpcginfo);
2037 		break;
2038 	case MPCG_STATE_XID7INITZ:
2039 	case MPCG_STATE_XID7INITX:
2040 		if (grp->outstanding_xid7 == 0) {
2041 			if (grp->outstanding_xid7_p2 > 0) {
2042 				grp->outstanding_xid7 =
2043 					grp->outstanding_xid7_p2;
2044 				grp->outstanding_xid7_p2 = 0;
2045 			} else
2046 				fsm_newstate(grp->fsm, MPCG_STATE_XID7INITF);
2047 
2048 			mpc_validate_xid(mpcginfo);
2049 			fsm_event(grp->fsm, MPCG_EVENT_XID7DONE, dev);
2050 			break;
2051 		}
2052 		mpc_validate_xid(mpcginfo);
2053 		break;
2054 	}
2055 	kfree(mpcginfo);
2056 	return;
2057 }
2058 
2059 /*
2060  * mpc_action helper of an MPC Group Station FSM action
2061  * CTCM_PROTO_MPC only
2062  */
2063 static int mpc_send_qllc_discontact(struct net_device *dev)
2064 {
2065 	__u32	new_len	= 0;
2066 	struct sk_buff   *skb;
2067 	struct qllc      *qllcptr;
2068 	struct ctcm_priv *priv = dev->ml_priv;
2069 	struct mpc_group *grp = priv->mpcg;
2070 
2071 	CTCM_PR_DEBUG("%s: GROUP STATE: %s\n",
2072 		__func__, mpcg_state_names[grp->saved_state]);
2073 
2074 	switch (grp->saved_state) {
2075 	/*
2076 	 * establish conn callback function is
2077 	 * preferred method to report failure
2078 	 */
2079 	case MPCG_STATE_XID0IOWAIT:
2080 	case MPCG_STATE_XID0IOWAIX:
2081 	case MPCG_STATE_XID7INITI:
2082 	case MPCG_STATE_XID7INITZ:
2083 	case MPCG_STATE_XID2INITW:
2084 	case MPCG_STATE_XID2INITX:
2085 	case MPCG_STATE_XID7INITW:
2086 	case MPCG_STATE_XID7INITX:
2087 		if (grp->estconnfunc) {
2088 			grp->estconnfunc(grp->port_num, -1, 0);
2089 			grp->estconnfunc = NULL;
2090 			break;
2091 		}
2092 		fallthrough;
2093 	case MPCG_STATE_FLOWC:
2094 	case MPCG_STATE_READY:
2095 		grp->send_qllc_disc = 2;
2096 		new_len = sizeof(struct qllc);
2097 		qllcptr = kzalloc(new_len, gfp_type() | GFP_DMA);
2098 		if (qllcptr == NULL) {
2099 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
2100 				"%s(%s): qllcptr allocation error",
2101 						CTCM_FUNTAIL, dev->name);
2102 			return -ENOMEM;
2103 		}
2104 
2105 		qllcptr->qllc_address = 0xcc;
2106 		qllcptr->qllc_commands = 0x03;
2107 
2108 		skb = __dev_alloc_skb(new_len, GFP_ATOMIC);
2109 
2110 		if (skb == NULL) {
2111 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
2112 				"%s(%s): skb allocation error",
2113 						CTCM_FUNTAIL, dev->name);
2114 			priv->stats.rx_dropped++;
2115 			kfree(qllcptr);
2116 			return -ENOMEM;
2117 		}
2118 
2119 		skb_put_data(skb, qllcptr, new_len);
2120 		kfree(qllcptr);
2121 
2122 		if (skb_headroom(skb) < 4) {
2123 			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
2124 				"%s(%s): skb_headroom error",
2125 						CTCM_FUNTAIL, dev->name);
2126 			dev_kfree_skb_any(skb);
2127 			return -ENOMEM;
2128 		}
2129 
2130 		*((__u32 *)skb_push(skb, 4)) =
2131 			priv->channel[CTCM_READ]->pdu_seq;
2132 		priv->channel[CTCM_READ]->pdu_seq++;
2133 		CTCM_PR_DBGDATA("ctcmpc: %s ToDCM_pdu_seq= %08x\n",
2134 				__func__, priv->channel[CTCM_READ]->pdu_seq);
2135 
2136 		/* receipt of CC03 resets anticipated sequence number on
2137 		      receiving side */
2138 		priv->channel[CTCM_READ]->pdu_seq = 0x00;
2139 		skb_reset_mac_header(skb);
2140 		skb->dev = dev;
2141 		skb->protocol = htons(ETH_P_SNAP);
2142 		skb->ip_summed = CHECKSUM_UNNECESSARY;
2143 
2144 		CTCM_D3_DUMP(skb->data, (sizeof(struct qllc) + 4));
2145 
2146 		netif_rx(skb);
2147 		break;
2148 	default:
2149 		break;
2150 
2151 	}
2152 
2153 	return 0;
2154 }
2155 /* --- This is the END my friend --- */
2156 
2157