drivers/s390/net/ctcm_mpc.c

// SPDX-License-Identifier: GPL-2.0
/*
 *	Copyright IBM Corp. 2004, 2007
 *	Authors:	Belinda Thompson (belindat@us.ibm.com)
 *			Andy Richter (richtera@us.ibm.com)
 *			Peter Tiedemann (ptiedem@de.ibm.com)
 */

/*
	This module exports functions to be used by CCS:
	EXPORT_SYMBOL(ctc_mpc_alloc_channel);
	EXPORT_SYMBOL(ctc_mpc_establish_connectivity);
	EXPORT_SYMBOL(ctc_mpc_dealloc_ch);
	EXPORT_SYMBOL(ctc_mpc_flow_control);
*/

#undef DEBUG
#undef DEBUGDATA
#undef DEBUGCCW

#define KMSG_COMPONENT "ctcm"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/sched.h>

#include <linux/signal.h>
#include <linux/string.h>
#include <linux/proc_fs.h>

#include <linux/ip.h>
#include <linux/if_arp.h>
#include <linux/tcp.h>
#include <linux/skbuff.h>
#include <linux/ctype.h>
#include <linux/netdevice.h>
#include <net/dst.h>

#include <linux/io.h>		/* instead of <asm/io.h> ok ? */
#include <asm/ccwdev.h>
#include <asm/ccwgroup.h>
#include <linux/bitops.h>	/* instead of <asm/bitops.h> ok ? */
#include <linux/uaccess.h>	/* instead of <asm/uaccess.h> ok ? */
#include <linux/wait.h>
#include <linux/moduleparam.h>
#include <asm/idals.h>

#include "ctcm_main.h"
#include "ctcm_mpc.h"
#include "ctcm_fsms.h"

static const struct xid2 init_xid = {
	.xid2_type_id	=	XID_FM2,
	.xid2_len	=	0x45,
	.xid2_adj_id	=	0,
	.xid2_rlen	=	0x31,
	.xid2_resv1	=	0,
	.xid2_flag1	=	0,
	.xid2_fmtt	=	0,
	.xid2_flag4	=	0x80,
	.xid2_resv2	=	0,
	.xid2_tgnum	=	0,
	.xid2_sender_id	=	0,
	.xid2_flag2	=	0,
	.xid2_option	=	XID2_0,
	.xid2_resv3	=	"\x00",
	.xid2_resv4	=	0,
	.xid2_dlc_type	=	XID2_READ_SIDE,
	.xid2_resv5	=	0,
	.xid2_mpc_flag	=	0,
	.xid2_resv6	=	0,
	.xid2_buf_len	=	(MPC_BUFSIZE_DEFAULT - 35),
};

static const struct th_header thnorm = {
	.th_seg		=	0x00,
	.th_ch_flag	=	TH_IS_XID,
	.th_blk_flag	=	TH_DATA_IS_XID,
	.th_is_xid	=	0x01,
	.th_seq_num	=	0x00000000,
};

static const struct th_header thdummy = {
	.th_seg		=	0x00,
	.th_ch_flag	=	0x00,
	.th_blk_flag	=	TH_DATA_IS_XID,
	.th_is_xid	=	0x01,
	.th_seq_num	=	0x00000000,
};

/*
 * Definition of one MPC group
 */

/*
 * Compatibility macros for busy handling
 * of network devices.
 */

static void ctcmpc_unpack_skb(struct channel *ch, struct sk_buff *pskb);

/*
 * MPC Group state machine actions (static prototypes)
 */
static void mpc_action_nop(fsm_instance *fsm, int event, void *arg);
static void mpc_action_go_ready(fsm_instance *fsm, int event, void *arg);
static void mpc_action_go_inop(fsm_instance *fi, int event, void *arg);
static void mpc_action_timeout(fsm_instance *fi, int event, void *arg);
static int  mpc_validate_xid(struct mpcg_info *mpcginfo);
static void mpc_action_yside_xid(fsm_instance *fsm, int event, void *arg);
static void mpc_action_doxid0(fsm_instance *fsm, int event, void *arg);
static void mpc_action_doxid7(fsm_instance *fsm, int event, void *arg);
static void mpc_action_xside_xid(fsm_instance *fsm, int event, void *arg);
static void mpc_action_rcvd_xid0(fsm_instance *fsm, int event, void *arg);
static void mpc_action_rcvd_xid7(fsm_instance *fsm, int event, void *arg);

#ifdef DEBUGDATA
/*-------------------------------------------------------------------*
* Dump buffer format						     *
*								     *
*--------------------------------------------------------------------*/
void ctcmpc_dumpit(char *buf, int len)
{
	__u32	ct, sw, rm, dup;
	char	*ptr, *rptr;
	char	tbuf[82], tdup[82];
	char	addr[22];
	char	boff[12];
	char	bhex[82], duphex[82];
	char	basc[40];

	sw  = 0;
	rptr = ptr = buf;
	rm  = 16;
	duphex[0] = 0x00;
	dup = 0;

	for (ct = 0; ct < len; ct++, ptr++, rptr++) {
		if (sw == 0) {
			sprintf(addr, "%16.16llx", (__u64)rptr);

			sprintf(boff, "%4.4X", (__u32)ct);
			bhex[0] = '\0';
			basc[0] = '\0';
		}
		if ((sw == 4) || (sw == 12))
			strcat(bhex, " ");
		if (sw == 8)
			strcat(bhex, "	");

		sprintf(tbuf, "%2.2llX", (__u64)*ptr);

		tbuf[2] = '\0';
		strcat(bhex, tbuf);
		if ((0 != isprint(*ptr)) && (*ptr >= 0x20))
			basc[sw] = *ptr;
		else
			basc[sw] = '.';

		basc[sw+1] = '\0';
		sw++;
		rm--;
		if (sw != 16)
			continue;
		if ((strcmp(duphex, bhex)) != 0) {
			if (dup != 0) {
				sprintf(tdup,
					"Duplicate as above to %s", addr);
				ctcm_pr_debug("		       --- %s ---\n",
						tdup);
			}
			ctcm_pr_debug("   %s (+%s) : %s  [%s]\n",
					addr, boff, bhex, basc);
			dup = 0;
			strcpy(duphex, bhex);
		} else
			dup++;

		sw = 0;
		rm = 16;
	}  /* endfor */

	if (sw != 0) {
		for ( ; rm > 0; rm--, sw++) {
			if ((sw == 4) || (sw == 12))
				strcat(bhex, " ");
			if (sw == 8)
				strcat(bhex, "	");
			strcat(bhex, "	");
			strcat(basc, " ");
		}
		if (dup != 0) {
			sprintf(tdup, "Duplicate as above to %s", addr);
			ctcm_pr_debug("		       --- %s ---\n", tdup);
		}
		ctcm_pr_debug("   %s (+%s) : %s  [%s]\n",
					addr, boff, bhex, basc);
	} else {
		if (dup >= 1) {
			sprintf(tdup, "Duplicate as above to %s", addr);
			ctcm_pr_debug("		       --- %s ---\n", tdup);
		}
		if (dup != 0) {
			ctcm_pr_debug("   %s (+%s) : %s  [%s]\n",
				addr, boff, bhex, basc);
		}
	}

	return;

}   /*	 end of ctcmpc_dumpit  */
#endif

#ifdef DEBUGDATA
/*
 * Dump header and first 16 bytes of an sk_buff for debugging purposes.
 *
 * skb		The sk_buff to dump.
 * offset	Offset relative to skb-data, where to start the dump.
 */
void ctcmpc_dump_skb(struct sk_buff *skb, int offset)
{
	__u8 *p = skb->data;
	struct th_header *header;
	struct pdu *pheader;
	int bl = skb->len;
	int i;

	if (p == NULL)
		return;

	p += offset;
	header = (struct th_header *)p;

	ctcm_pr_debug("dump:\n");
	ctcm_pr_debug("skb len=%d \n", skb->len);
	if (skb->len > 2) {
		switch (header->th_ch_flag) {
		case TH_HAS_PDU:
			break;
		case 0x00:
		case TH_IS_XID:
			if ((header->th_blk_flag == TH_DATA_IS_XID) &&
			   (header->th_is_xid == 0x01))
				goto dumpth;
		case TH_SWEEP_REQ:
				goto dumpth;
		case TH_SWEEP_RESP:
				goto dumpth;
		default:
			break;
		}

		pheader = (struct pdu *)p;
		ctcm_pr_debug("pdu->offset: %d hex: %04x\n",
			       pheader->pdu_offset, pheader->pdu_offset);
		ctcm_pr_debug("pdu->flag  : %02x\n", pheader->pdu_flag);
		ctcm_pr_debug("pdu->proto : %02x\n", pheader->pdu_proto);
		ctcm_pr_debug("pdu->seq   : %02x\n", pheader->pdu_seq);
					goto dumpdata;

dumpth:
		ctcm_pr_debug("th->seg     : %02x\n", header->th_seg);
		ctcm_pr_debug("th->ch      : %02x\n", header->th_ch_flag);
		ctcm_pr_debug("th->blk_flag: %02x\n", header->th_blk_flag);
		ctcm_pr_debug("th->type    : %s\n",
			       (header->th_is_xid) ? "DATA" : "XID");
		ctcm_pr_debug("th->seqnum  : %04x\n", header->th_seq_num);

	}
dumpdata:
	if (bl > 32)
		bl = 32;
	ctcm_pr_debug("data: ");
	for (i = 0; i < bl; i++)
		ctcm_pr_debug("%02x%s", *p++, (i % 16) ? " " : "\n");
	ctcm_pr_debug("\n");
}
#endif

static struct net_device *ctcmpc_get_dev(int port_num)
{
	char device[20];
	struct net_device *dev;
	struct ctcm_priv *priv;

	sprintf(device, "%s%i", MPC_DEVICE_NAME, port_num);

	dev = __dev_get_by_name(&init_net, device);

	if (dev == NULL) {
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s: Device not found by name: %s",
					CTCM_FUNTAIL, device);
		return NULL;
	}
	priv = dev->ml_priv;
	if (priv == NULL) {
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): dev->ml_priv is NULL",
					CTCM_FUNTAIL, device);
		return NULL;
	}
	if (priv->mpcg == NULL) {
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): priv->mpcg is NULL",
					CTCM_FUNTAIL, device);
		return NULL;
	}
	return dev;
}

/*
 * ctc_mpc_alloc_channel
 *	(exported interface)
 *
 * Device Initialization :
 *	ACTPATH  driven IO operations
 */
int ctc_mpc_alloc_channel(int port_num, void (*callback)(int, int))
{
	struct net_device *dev;
	struct mpc_group *grp;
	struct ctcm_priv *priv;

	dev = ctcmpc_get_dev(port_num);
	if (dev == NULL)
		return 1;
	priv = dev->ml_priv;
	grp = priv->mpcg;

	grp->allochanfunc = callback;
	grp->port_num = port_num;
	grp->port_persist = 1;

	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_INFO,
			"%s(%s): state=%s",
			CTCM_FUNTAIL, dev->name, fsm_getstate_str(grp->fsm));

	switch (fsm_getstate(grp->fsm)) {
	case MPCG_STATE_INOP:
		/* Group is in the process of terminating */
		grp->alloc_called = 1;
		break;
	case MPCG_STATE_RESET:
		/* MPC Group will transition to state		  */
		/* MPCG_STATE_XID2INITW iff the minimum number	  */
		/* of 1 read and 1 write channel have successfully*/
		/* activated					  */
		/*fsm_newstate(grp->fsm, MPCG_STATE_XID2INITW);*/
		if (callback)
			grp->send_qllc_disc = 1;
		fallthrough;
	case MPCG_STATE_XID0IOWAIT:
		fsm_deltimer(&grp->timer);
		grp->outstanding_xid2 = 0;
		grp->outstanding_xid7 = 0;
		grp->outstanding_xid7_p2 = 0;
		grp->saved_xid2 = NULL;
		if (callback)
			ctcm_open(dev);
		fsm_event(priv->fsm, DEV_EVENT_START, dev);
		break;
	case MPCG_STATE_READY:
		/* XID exchanges completed after PORT was activated */
		/* Link station already active			    */
		/* Maybe timing issue...retry callback		    */
		grp->allocchan_callback_retries++;
		if (grp->allocchan_callback_retries < 4) {
			if (grp->allochanfunc)
				grp->allochanfunc(grp->port_num,
						  grp->group_max_buflen);
		} else {
			/* there are problems...bail out	    */
			/* there may be a state mismatch so restart */
			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
			grp->allocchan_callback_retries = 0;
		}
		break;
	}

	return 0;
}
EXPORT_SYMBOL(ctc_mpc_alloc_channel);

/*
 * ctc_mpc_establish_connectivity
 *	(exported interface)
 */
void ctc_mpc_establish_connectivity(int port_num,
				void (*callback)(int, int, int))
{
	struct net_device *dev;
	struct mpc_group *grp;
	struct ctcm_priv *priv;
	struct channel *rch, *wch;

	dev = ctcmpc_get_dev(port_num);
	if (dev == NULL)
		return;
	priv = dev->ml_priv;
	grp = priv->mpcg;
	rch = priv->channel[CTCM_READ];
	wch = priv->channel[CTCM_WRITE];

	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_INFO,
			"%s(%s): state=%s",
			CTCM_FUNTAIL, dev->name, fsm_getstate_str(grp->fsm));

	grp->estconnfunc = callback;
	grp->port_num = port_num;

	switch (fsm_getstate(grp->fsm)) {
	case MPCG_STATE_READY:
		/* XID exchanges completed after PORT was activated */
		/* Link station already active			    */
		/* Maybe timing issue...retry callback		    */
		fsm_deltimer(&grp->timer);
		grp->estconn_callback_retries++;
		if (grp->estconn_callback_retries < 4) {
			if (grp->estconnfunc) {
				grp->estconnfunc(grp->port_num, 0,
						grp->group_max_buflen);
				grp->estconnfunc = NULL;
			}
		} else {
			/* there are problems...bail out	 */
			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
			grp->estconn_callback_retries = 0;
		}
		break;
	case MPCG_STATE_INOP:
	case MPCG_STATE_RESET:
		/* MPC Group is not ready to start XID - min num of */
		/* 1 read and 1 write channel have not been acquired*/

		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): REJECTED - inactive channels",
					CTCM_FUNTAIL, dev->name);
		if (grp->estconnfunc) {
			grp->estconnfunc(grp->port_num, -1, 0);
			grp->estconnfunc = NULL;
		}
		break;
	case MPCG_STATE_XID2INITW:
		/* alloc channel was called but no XID exchange    */
		/* has occurred. initiate xside XID exchange	   */
		/* make sure yside XID0 processing has not started */

		if ((fsm_getstate(rch->fsm) > CH_XID0_PENDING) ||
			(fsm_getstate(wch->fsm) > CH_XID0_PENDING)) {
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): ABORT - PASSIVE XID",
					CTCM_FUNTAIL, dev->name);
			break;
		}
		grp->send_qllc_disc = 1;
		fsm_newstate(grp->fsm, MPCG_STATE_XID0IOWAIT);
		fsm_deltimer(&grp->timer);
		fsm_addtimer(&grp->timer, MPC_XID_TIMEOUT_VALUE,
						MPCG_EVENT_TIMER, dev);
		grp->outstanding_xid7 = 0;
		grp->outstanding_xid7_p2 = 0;
		grp->saved_xid2 = NULL;
		if ((rch->in_mpcgroup) &&
				(fsm_getstate(rch->fsm) == CH_XID0_PENDING))
			fsm_event(grp->fsm, MPCG_EVENT_XID0DO, rch);
		else {
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): RX-%s not ready for ACTIVE XID0",
					CTCM_FUNTAIL, dev->name, rch->id);
			if (grp->estconnfunc) {
				grp->estconnfunc(grp->port_num, -1, 0);
				grp->estconnfunc = NULL;
			}
			fsm_deltimer(&grp->timer);
				goto done;
		}
		if ((wch->in_mpcgroup) &&
				(fsm_getstate(wch->fsm) == CH_XID0_PENDING))
			fsm_event(grp->fsm, MPCG_EVENT_XID0DO, wch);
		else {
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): WX-%s not ready for ACTIVE XID0",
					CTCM_FUNTAIL, dev->name, wch->id);
			if (grp->estconnfunc) {
				grp->estconnfunc(grp->port_num, -1, 0);
				grp->estconnfunc = NULL;
			}
			fsm_deltimer(&grp->timer);
				goto done;
			}
		break;
	case MPCG_STATE_XID0IOWAIT:
		/* already in active XID negotiations */
	default:
		break;
	}

done:
	CTCM_PR_DEBUG("Exit %s()\n", __func__);
	return;
}
EXPORT_SYMBOL(ctc_mpc_establish_connectivity);

/*
 * ctc_mpc_dealloc_ch
 *	(exported interface)
 */
void ctc_mpc_dealloc_ch(int port_num)
{
	struct net_device *dev;
	struct ctcm_priv *priv;
	struct mpc_group *grp;

	dev = ctcmpc_get_dev(port_num);
	if (dev == NULL)
		return;
	priv = dev->ml_priv;
	grp = priv->mpcg;

	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_DEBUG,
			"%s: %s: refcount = %d\n",
			CTCM_FUNTAIL, dev->name, netdev_refcnt_read(dev));

	fsm_deltimer(&priv->restart_timer);
	grp->channels_terminating = 0;
	fsm_deltimer(&grp->timer);
	grp->allochanfunc = NULL;
	grp->estconnfunc = NULL;
	grp->port_persist = 0;
	grp->send_qllc_disc = 0;
	fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);

	ctcm_close(dev);
	return;
}
EXPORT_SYMBOL(ctc_mpc_dealloc_ch);

/*
 * ctc_mpc_flow_control
 *	(exported interface)
 */
void ctc_mpc_flow_control(int port_num, int flowc)
{
	struct ctcm_priv *priv;
	struct mpc_group *grp;
	struct net_device *dev;
	struct channel *rch;
	int mpcg_state;

	dev = ctcmpc_get_dev(port_num);
	if (dev == NULL)
		return;
	priv = dev->ml_priv;
	grp = priv->mpcg;

	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
			"%s: %s: flowc = %d",
				CTCM_FUNTAIL, dev->name, flowc);

	rch = priv->channel[CTCM_READ];

	mpcg_state = fsm_getstate(grp->fsm);
	switch (flowc) {
	case 1:
		if (mpcg_state == MPCG_STATE_FLOWC)
			break;
		if (mpcg_state == MPCG_STATE_READY) {
			if (grp->flow_off_called == 1)
				grp->flow_off_called = 0;
			else
				fsm_newstate(grp->fsm, MPCG_STATE_FLOWC);
			break;
		}
		break;
	case 0:
		if (mpcg_state == MPCG_STATE_FLOWC) {
			fsm_newstate(grp->fsm, MPCG_STATE_READY);
			/* ensure any data that has accumulated */
			/* on the io_queue will now be sen t	*/
			tasklet_schedule(&rch->ch_tasklet);
		}
		/* possible race condition			*/
		if (mpcg_state == MPCG_STATE_READY) {
			grp->flow_off_called = 1;
			break;
		}
		break;
	}

}
EXPORT_SYMBOL(ctc_mpc_flow_control);

static int mpc_send_qllc_discontact(struct net_device *);

/*
 * helper function of ctcmpc_unpack_skb
*/
static void mpc_rcvd_sweep_resp(struct mpcg_info *mpcginfo)
{
	struct channel	  *rch = mpcginfo->ch;
	struct net_device *dev = rch->netdev;
	struct ctcm_priv   *priv = dev->ml_priv;
	struct mpc_group  *grp = priv->mpcg;
	struct channel	  *ch = priv->channel[CTCM_WRITE];

	CTCM_PR_DEBUG("%s: ch=0x%p id=%s\n", __func__, ch, ch->id);
	CTCM_D3_DUMP((char *)mpcginfo->sweep, TH_SWEEP_LENGTH);

	grp->sweep_rsp_pend_num--;

	if ((grp->sweep_req_pend_num == 0) &&
			(grp->sweep_rsp_pend_num == 0)) {
		fsm_deltimer(&ch->sweep_timer);
		grp->in_sweep = 0;
		rch->th_seq_num = 0x00;
		ch->th_seq_num = 0x00;
		ctcm_clear_busy_do(dev);
	}

	return;

}

/*
 * helper function of mpc_rcvd_sweep_req
 * which is a helper of ctcmpc_unpack_skb
 */
static void ctcmpc_send_sweep_resp(struct channel *rch)
{
	struct net_device *dev = rch->netdev;
	struct ctcm_priv *priv = dev->ml_priv;
	struct mpc_group *grp = priv->mpcg;
	struct th_sweep *header;
	struct sk_buff *sweep_skb;
	struct channel *ch  = priv->channel[CTCM_WRITE];

	CTCM_PR_DEBUG("%s: ch=0x%p id=%s\n", __func__, rch, rch->id);

	sweep_skb = __dev_alloc_skb(MPC_BUFSIZE_DEFAULT, GFP_ATOMIC | GFP_DMA);
	if (sweep_skb == NULL) {
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): sweep_skb allocation ERROR\n",
			CTCM_FUNTAIL, rch->id);
		goto done;
	}

	header = skb_put_zero(sweep_skb, TH_SWEEP_LENGTH);
	header->th.th_ch_flag	= TH_SWEEP_RESP;
	header->sw.th_last_seq	= ch->th_seq_num;

	netif_trans_update(dev);
	skb_queue_tail(&ch->sweep_queue, sweep_skb);

	fsm_addtimer(&ch->sweep_timer, 100, CTC_EVENT_RSWEEP_TIMER, ch);

	return;

done:
	grp->in_sweep = 0;
	ctcm_clear_busy_do(dev);
	fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);

	return;
}

/*
 * helper function of ctcmpc_unpack_skb
 */
static void mpc_rcvd_sweep_req(struct mpcg_info *mpcginfo)
{
	struct channel	  *rch     = mpcginfo->ch;
	struct net_device *dev     = rch->netdev;
	struct ctcm_priv  *priv = dev->ml_priv;
	struct mpc_group  *grp  = priv->mpcg;
	struct channel	  *ch	   = priv->channel[CTCM_WRITE];

	if (do_debug)
		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
			" %s(): ch=0x%p id=%s\n", __func__, ch, ch->id);

	if (grp->in_sweep == 0) {
		grp->in_sweep = 1;
		ctcm_test_and_set_busy(dev);
		grp->sweep_req_pend_num = grp->active_channels[CTCM_READ];
		grp->sweep_rsp_pend_num = grp->active_channels[CTCM_READ];
	}

	CTCM_D3_DUMP((char *)mpcginfo->sweep, TH_SWEEP_LENGTH);

	grp->sweep_req_pend_num--;
	ctcmpc_send_sweep_resp(ch);
	kfree(mpcginfo);
	return;
}

/*
  * MPC Group Station FSM definitions
 */
static const char *mpcg_event_names[] = {
	[MPCG_EVENT_INOP]	= "INOP Condition",
	[MPCG_EVENT_DISCONC]	= "Discontact Received",
	[MPCG_EVENT_XID0DO]	= "Channel Active - Start XID",
	[MPCG_EVENT_XID2]	= "XID2 Received",
	[MPCG_EVENT_XID2DONE]	= "XID0 Complete",
	[MPCG_EVENT_XID7DONE]	= "XID7 Complete",
	[MPCG_EVENT_TIMER]	= "XID Setup Timer",
	[MPCG_EVENT_DOIO]	= "XID DoIO",
};

static const char *mpcg_state_names[] = {
	[MPCG_STATE_RESET]	= "Reset",
	[MPCG_STATE_INOP]	= "INOP",
	[MPCG_STATE_XID2INITW]	= "Passive XID- XID0 Pending Start",
	[MPCG_STATE_XID2INITX]	= "Passive XID- XID0 Pending Complete",
	[MPCG_STATE_XID7INITW]	= "Passive XID- XID7 Pending P1 Start",
	[MPCG_STATE_XID7INITX]	= "Passive XID- XID7 Pending P2 Complete",
	[MPCG_STATE_XID0IOWAIT]	= "Active  XID- XID0 Pending Start",
	[MPCG_STATE_XID0IOWAIX]	= "Active  XID- XID0 Pending Complete",
	[MPCG_STATE_XID7INITI]	= "Active  XID- XID7 Pending Start",
	[MPCG_STATE_XID7INITZ]	= "Active  XID- XID7 Pending Complete ",
	[MPCG_STATE_XID7INITF]	= "XID        - XID7 Complete ",
	[MPCG_STATE_FLOWC]	= "FLOW CONTROL ON",
	[MPCG_STATE_READY]	= "READY",
};

/*
 * The MPC Group Station FSM
 *   22 events
 */
static const fsm_node mpcg_fsm[] = {
	{ MPCG_STATE_RESET,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_INOP,	MPCG_EVENT_INOP,	mpc_action_nop        },
	{ MPCG_STATE_FLOWC,	MPCG_EVENT_INOP,	mpc_action_go_inop    },

	{ MPCG_STATE_READY,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
	{ MPCG_STATE_READY,	MPCG_EVENT_INOP,	mpc_action_go_inop    },

	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_XID0DO,	mpc_action_doxid0     },
	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid0  },
	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
	{ MPCG_STATE_XID2INITW,	MPCG_EVENT_DOIO,	mpc_action_yside_xid  },

	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_XID0DO,	mpc_action_doxid0     },
	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid0  },
	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
	{ MPCG_STATE_XID2INITX,	MPCG_EVENT_DOIO,	mpc_action_yside_xid  },

	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_XID2DONE,	mpc_action_doxid7     },
	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid7  },
	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_XID7DONE,	mpc_action_doxid7     },
	{ MPCG_STATE_XID7INITW,	MPCG_EVENT_DOIO,	mpc_action_yside_xid  },

	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid7  },
	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_XID7DONE,	mpc_action_doxid7     },
	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
	{ MPCG_STATE_XID7INITX,	MPCG_EVENT_DOIO,	mpc_action_yside_xid  },

	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_XID0DO,	mpc_action_doxid0     },
	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_DISCONC,	mpc_action_discontact },
	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_XID2,	mpc_action_rcvd_xid0  },
	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_TIMER,	mpc_action_timeout    },
	{ MPCG_STATE_XID0IOWAIT, MPCG_EVENT_DOIO,	mpc_action_xside_xid  },

	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_XID0DO,	mpc_action_doxid0     },
	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_DISCONC,	mpc_action_discontact },
	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_XID2,	mpc_action_rcvd_xid0  },
	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_TIMER,	mpc_action_timeout    },
	{ MPCG_STATE_XID0IOWAIX, MPCG_EVENT_DOIO,	mpc_action_xside_xid  },

	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_XID2DONE,	mpc_action_doxid7     },
	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid7  },
	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_XID7DONE,	mpc_action_doxid7     },
	{ MPCG_STATE_XID7INITI,	MPCG_EVENT_DOIO,	mpc_action_xside_xid  },

	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_XID2,	mpc_action_rcvd_xid7  },
	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_XID7DONE,	mpc_action_doxid7     },
	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_DISCONC,	mpc_action_discontact },
	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_TIMER,	mpc_action_timeout    },
	{ MPCG_STATE_XID7INITZ,	MPCG_EVENT_DOIO,	mpc_action_xside_xid  },

	{ MPCG_STATE_XID7INITF,	MPCG_EVENT_INOP,	mpc_action_go_inop    },
	{ MPCG_STATE_XID7INITF,	MPCG_EVENT_XID7DONE,	mpc_action_go_ready   },
};

static int mpcg_fsm_len = ARRAY_SIZE(mpcg_fsm);

/*
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 */
static void mpc_action_go_ready(fsm_instance *fsm, int event, void *arg)
{
	struct net_device *dev = arg;
	struct ctcm_priv *priv = dev->ml_priv;
	struct mpc_group *grp = priv->mpcg;

	if (grp == NULL) {
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): No MPC group",
				CTCM_FUNTAIL, dev->name);
		return;
	}

	fsm_deltimer(&grp->timer);

	if (grp->saved_xid2->xid2_flag2 == 0x40) {
		priv->xid->xid2_flag2 = 0x00;
		if (grp->estconnfunc) {
			grp->estconnfunc(grp->port_num, 1,
					grp->group_max_buflen);
			grp->estconnfunc = NULL;
		} else if (grp->allochanfunc)
			grp->send_qllc_disc = 1;

		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): fails",
					CTCM_FUNTAIL, dev->name);
		return;
	}

	grp->port_persist = 1;
	grp->out_of_sequence = 0;
	grp->estconn_called = 0;

	tasklet_hi_schedule(&grp->mpc_tasklet2);

	return;
}

/*
 * helper of ctcm_init_netdevice
 * CTCM_PROTO_MPC only
 */
void mpc_group_ready(unsigned long adev)
{
	struct net_device *dev = (struct net_device *)adev;
	struct ctcm_priv *priv = dev->ml_priv;
	struct mpc_group *grp = priv->mpcg;
	struct channel *ch = NULL;

	if (grp == NULL) {
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): No MPC group",
				CTCM_FUNTAIL, dev->name);
		return;
	}

	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_NOTICE,
		"%s: %s: GROUP TRANSITIONED TO READY, maxbuf = %d\n",
			CTCM_FUNTAIL, dev->name, grp->group_max_buflen);

	fsm_newstate(grp->fsm, MPCG_STATE_READY);

	/* Put up a read on the channel */
	ch = priv->channel[CTCM_READ];
	ch->pdu_seq = 0;
	CTCM_PR_DBGDATA("ctcmpc: %s() ToDCM_pdu_seq= %08x\n" ,
			__func__, ch->pdu_seq);

	ctcmpc_chx_rxidle(ch->fsm, CTC_EVENT_START, ch);
	/* Put the write channel in idle state */
	ch = priv->channel[CTCM_WRITE];
	if (ch->collect_len > 0) {
		spin_lock(&ch->collect_lock);
		ctcm_purge_skb_queue(&ch->collect_queue);
		ch->collect_len = 0;
		spin_unlock(&ch->collect_lock);
	}
	ctcm_chx_txidle(ch->fsm, CTC_EVENT_START, ch);
	ctcm_clear_busy(dev);

	if (grp->estconnfunc) {
		grp->estconnfunc(grp->port_num, 0,
				    grp->group_max_buflen);
		grp->estconnfunc = NULL;
	} else 	if (grp->allochanfunc)
		grp->allochanfunc(grp->port_num, grp->group_max_buflen);

	grp->send_qllc_disc = 1;
	grp->changed_side = 0;

	return;

}

/*
 * Increment the MPC Group Active Channel Counts
 * helper of dev_action (called from channel fsm)
 */
void mpc_channel_action(struct channel *ch, int direction, int action)
{
	struct net_device  *dev  = ch->netdev;
	struct ctcm_priv   *priv = dev->ml_priv;
	struct mpc_group   *grp  = priv->mpcg;

	if (grp == NULL) {
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): No MPC group",
				CTCM_FUNTAIL, dev->name);
		return;
	}

	CTCM_PR_DEBUG("enter %s: ch=0x%p id=%s\n", __func__, ch, ch->id);

	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
		"%s: %i / Grp:%s total_channels=%i, active_channels: "
		"read=%i, write=%i\n", __func__, action,
		fsm_getstate_str(grp->fsm), grp->num_channel_paths,
		grp->active_channels[CTCM_READ],
		grp->active_channels[CTCM_WRITE]);

	if ((action == MPC_CHANNEL_ADD) && (ch->in_mpcgroup == 0)) {
		grp->num_channel_paths++;
		grp->active_channels[direction]++;
		grp->outstanding_xid2++;
		ch->in_mpcgroup = 1;

		if (ch->xid_skb != NULL)
			dev_kfree_skb_any(ch->xid_skb);

		ch->xid_skb = __dev_alloc_skb(MPC_BUFSIZE_DEFAULT,
					GFP_ATOMIC | GFP_DMA);
		if (ch->xid_skb == NULL) {
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): Couldn't alloc ch xid_skb\n",
				CTCM_FUNTAIL, dev->name);
			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
			return;
		}
		ch->xid_skb_data = ch->xid_skb->data;
		ch->xid_th = (struct th_header *)ch->xid_skb->data;
		skb_put(ch->xid_skb, TH_HEADER_LENGTH);
		ch->xid = (struct xid2 *)skb_tail_pointer(ch->xid_skb);
		skb_put(ch->xid_skb, XID2_LENGTH);
		ch->xid_id = skb_tail_pointer(ch->xid_skb);
		ch->xid_skb->data = ch->xid_skb_data;
		skb_reset_tail_pointer(ch->xid_skb);
		ch->xid_skb->len = 0;

		skb_put_data(ch->xid_skb, grp->xid_skb->data,
			     grp->xid_skb->len);

		ch->xid->xid2_dlc_type =
			((CHANNEL_DIRECTION(ch->flags) == CTCM_READ)
				? XID2_READ_SIDE : XID2_WRITE_SIDE);

		if (CHANNEL_DIRECTION(ch->flags) == CTCM_WRITE)
			ch->xid->xid2_buf_len = 0x00;

		ch->xid_skb->data = ch->xid_skb_data;
		skb_reset_tail_pointer(ch->xid_skb);
		ch->xid_skb->len = 0;

		fsm_newstate(ch->fsm, CH_XID0_PENDING);

		if ((grp->active_channels[CTCM_READ] > 0) &&
		    (grp->active_channels[CTCM_WRITE] > 0) &&
			(fsm_getstate(grp->fsm) < MPCG_STATE_XID2INITW)) {
			fsm_newstate(grp->fsm, MPCG_STATE_XID2INITW);
			CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_NOTICE,
				"%s: %s: MPC GROUP CHANNELS ACTIVE\n",
						__func__, dev->name);
		}
	} else if ((action == MPC_CHANNEL_REMOVE) &&
			(ch->in_mpcgroup == 1)) {
		ch->in_mpcgroup = 0;
		grp->num_channel_paths--;
		grp->active_channels[direction]--;

		if (ch->xid_skb != NULL)
			dev_kfree_skb_any(ch->xid_skb);
		ch->xid_skb = NULL;

		if (grp->channels_terminating)
					goto done;

		if (((grp->active_channels[CTCM_READ] == 0) &&
					(grp->active_channels[CTCM_WRITE] > 0))
			|| ((grp->active_channels[CTCM_WRITE] == 0) &&
					(grp->active_channels[CTCM_READ] > 0)))
			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
	}
done:
	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
		"exit %s: %i / Grp:%s total_channels=%i, active_channels: "
		"read=%i, write=%i\n", __func__, action,
		fsm_getstate_str(grp->fsm), grp->num_channel_paths,
		grp->active_channels[CTCM_READ],
		grp->active_channels[CTCM_WRITE]);

	CTCM_PR_DEBUG("exit %s: ch=0x%p id=%s\n", __func__, ch, ch->id);
}

/*
 * Unpack a just received skb and hand it over to
 * upper layers.
 * special MPC version of unpack_skb.
 *
 * ch		The channel where this skb has been received.
 * pskb		The received skb.
 */
static void ctcmpc_unpack_skb(struct channel *ch, struct sk_buff *pskb)
{
	struct net_device *dev	= ch->netdev;
	struct ctcm_priv *priv = dev->ml_priv;
	struct mpc_group *grp = priv->mpcg;
	struct pdu *curr_pdu;
	struct mpcg_info *mpcginfo;
	struct th_header *header = NULL;
	struct th_sweep *sweep = NULL;
	int pdu_last_seen = 0;
	__u32 new_len;
	struct sk_buff *skb;
	int skblen;
	int sendrc = 0;

	CTCM_PR_DEBUG("ctcmpc enter: %s() %s cp:%i ch:%s\n",
			__func__, dev->name, smp_processor_id(), ch->id);

	header = (struct th_header *)pskb->data;
	if ((header->th_seg == 0) &&
		(header->th_ch_flag == 0) &&
		(header->th_blk_flag == 0) &&
		(header->th_seq_num == 0))
		/* nothing for us */	goto done;

	CTCM_PR_DBGDATA("%s: th_header\n", __func__);
	CTCM_D3_DUMP((char *)header, TH_HEADER_LENGTH);
	CTCM_PR_DBGDATA("%s: pskb len: %04x \n", __func__, pskb->len);

	pskb->dev = dev;
	pskb->ip_summed = CHECKSUM_UNNECESSARY;
	skb_pull(pskb, TH_HEADER_LENGTH);

	if (likely(header->th_ch_flag == TH_HAS_PDU)) {
		CTCM_PR_DBGDATA("%s: came into th_has_pdu\n", __func__);
		if ((fsm_getstate(grp->fsm) == MPCG_STATE_FLOWC) ||
		   ((fsm_getstate(grp->fsm) == MPCG_STATE_READY) &&
		    (header->th_seq_num != ch->th_seq_num + 1) &&
		    (ch->th_seq_num != 0))) {
			/* This is NOT the next segment		*
			 * we are not the correct race winner	*
			 * go away and let someone else win	*
			 * BUT..this only applies if xid negot	*
			 * is done				*
			*/
			grp->out_of_sequence += 1;
			__skb_push(pskb, TH_HEADER_LENGTH);
			skb_queue_tail(&ch->io_queue, pskb);
			CTCM_PR_DBGDATA("%s: th_seq_num expect:%08x "
					"got:%08x\n", __func__,
				ch->th_seq_num + 1, header->th_seq_num);

			return;
		}
		grp->out_of_sequence = 0;
		ch->th_seq_num = header->th_seq_num;

		CTCM_PR_DBGDATA("ctcmpc: %s() FromVTAM_th_seq=%08x\n",
					__func__, ch->th_seq_num);

		if (unlikely(fsm_getstate(grp->fsm) != MPCG_STATE_READY))
					goto done;
		while ((pskb->len > 0) && !pdu_last_seen) {
			curr_pdu = (struct pdu *)pskb->data;

			CTCM_PR_DBGDATA("%s: pdu_header\n", __func__);
			CTCM_D3_DUMP((char *)pskb->data, PDU_HEADER_LENGTH);
			CTCM_PR_DBGDATA("%s: pskb len: %04x \n",
						__func__, pskb->len);

			skb_pull(pskb, PDU_HEADER_LENGTH);

			if (curr_pdu->pdu_flag & PDU_LAST)
				pdu_last_seen = 1;
			if (curr_pdu->pdu_flag & PDU_CNTL)
				pskb->protocol = htons(ETH_P_SNAP);
			else
				pskb->protocol = htons(ETH_P_SNA_DIX);

			if ((pskb->len <= 0) || (pskb->len > ch->max_bufsize)) {
				CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
					"%s(%s): Dropping packet with "
					"illegal siize %d",
					CTCM_FUNTAIL, dev->name, pskb->len);

				priv->stats.rx_dropped++;
				priv->stats.rx_length_errors++;
					goto done;
			}
			skb_reset_mac_header(pskb);
			new_len = curr_pdu->pdu_offset;
			CTCM_PR_DBGDATA("%s: new_len: %04x \n",
						__func__, new_len);
			if ((new_len == 0) || (new_len > pskb->len)) {
				/* should never happen		    */
				/* pskb len must be hosed...bail out */
				CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
					"%s(%s): non valid pdu_offset: %04x",
					/* "data may be lost", */
					CTCM_FUNTAIL, dev->name, new_len);
				goto done;
			}
			skb = __dev_alloc_skb(new_len+4, GFP_ATOMIC);

			if (!skb) {
				CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
					"%s(%s): MEMORY allocation error",
						CTCM_FUNTAIL, dev->name);
				priv->stats.rx_dropped++;
				fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
						goto done;
			}
			skb_put_data(skb, pskb->data, new_len);

			skb_reset_mac_header(skb);
			skb->dev = pskb->dev;
			skb->protocol = pskb->protocol;
			skb->ip_summed = CHECKSUM_UNNECESSARY;
			*((__u32 *) skb_push(skb, 4)) = ch->pdu_seq;
			ch->pdu_seq++;

			if (do_debug_data) {
				ctcm_pr_debug("%s: ToDCM_pdu_seq= %08x\n",
						__func__, ch->pdu_seq);
				ctcm_pr_debug("%s: skb:%0lx "
					"skb len: %d \n", __func__,
					(unsigned long)skb, skb->len);
				ctcm_pr_debug("%s: up to 32 bytes "
					"of pdu_data sent\n", __func__);
				ctcmpc_dump32((char *)skb->data, skb->len);
			}

			skblen = skb->len;
			sendrc = netif_rx(skb);
			priv->stats.rx_packets++;
			priv->stats.rx_bytes += skblen;
			skb_pull(pskb, new_len); /* point to next PDU */
		}
	} else {
		mpcginfo = kmalloc(sizeof(struct mpcg_info), GFP_ATOMIC);
		if (mpcginfo == NULL)
					goto done;

		mpcginfo->ch = ch;
		mpcginfo->th = header;
		mpcginfo->skb = pskb;
		CTCM_PR_DEBUG("%s: Not PDU - may be control pkt\n",
					__func__);
		/*  it's a sweep?   */
		sweep = (struct th_sweep *)pskb->data;
		mpcginfo->sweep = sweep;
		if (header->th_ch_flag == TH_SWEEP_REQ)
			mpc_rcvd_sweep_req(mpcginfo);
		else if (header->th_ch_flag == TH_SWEEP_RESP)
			mpc_rcvd_sweep_resp(mpcginfo);
		else if (header->th_blk_flag == TH_DATA_IS_XID) {
			struct xid2 *thisxid = (struct xid2 *)pskb->data;
			skb_pull(pskb, XID2_LENGTH);
			mpcginfo->xid = thisxid;
			fsm_event(grp->fsm, MPCG_EVENT_XID2, mpcginfo);
		} else if (header->th_blk_flag == TH_DISCONTACT)
			fsm_event(grp->fsm, MPCG_EVENT_DISCONC, mpcginfo);
		else if (header->th_seq_num != 0) {
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): control pkt expected\n",
						CTCM_FUNTAIL, dev->name);
			priv->stats.rx_dropped++;
			/* mpcginfo only used for non-data transfers */
			if (do_debug_data)
				ctcmpc_dump_skb(pskb, -8);
		}
		kfree(mpcginfo);
	}
done:

	dev_kfree_skb_any(pskb);
	if (sendrc == NET_RX_DROP) {
		dev_warn(&dev->dev,
			"The network backlog for %s is exceeded, "
			"package dropped\n", __func__);
		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
	}

	CTCM_PR_DEBUG("exit %s: %s: ch=0x%p id=%s\n",
			__func__, dev->name, ch, ch->id);
}

/*
 * tasklet helper for mpc's skb unpacking.
 *
 * ch		The channel to work on.
 * Allow flow control back pressure to occur here.
 * Throttling back channel can result in excessive
 * channel inactivity and system deact of channel
 */
void ctcmpc_bh(unsigned long thischan)
{
	struct channel	  *ch	= (struct channel *)thischan;
	struct sk_buff	  *skb;
	struct net_device *dev	= ch->netdev;
	struct ctcm_priv  *priv	= dev->ml_priv;
	struct mpc_group  *grp	= priv->mpcg;

	CTCM_PR_DEBUG("%s cp:%i enter:  %s() %s\n",
	       dev->name, smp_processor_id(), __func__, ch->id);
	/* caller has requested driver to throttle back */
	while ((fsm_getstate(grp->fsm) != MPCG_STATE_FLOWC) &&
			(skb = skb_dequeue(&ch->io_queue))) {
		ctcmpc_unpack_skb(ch, skb);
		if (grp->out_of_sequence > 20) {
			/* assume data loss has occurred if */
			/* missing seq_num for extended     */
			/* period of time		    */
			grp->out_of_sequence = 0;
			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
			break;
		}
		if (skb == skb_peek(&ch->io_queue))
			break;
	}
	CTCM_PR_DEBUG("exit %s: %s: ch=0x%p id=%s\n",
			__func__, dev->name, ch, ch->id);
	return;
}

/*
 *  MPC Group Initializations
 */
struct mpc_group *ctcmpc_init_mpc_group(struct ctcm_priv *priv)
{
	struct mpc_group *grp;

	CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_INFO,
			"Enter %s(%p)", CTCM_FUNTAIL, priv);

	grp = kzalloc(sizeof(struct mpc_group), GFP_KERNEL);
	if (grp == NULL)
		return NULL;

	grp->fsm = init_fsm("mpcg", mpcg_state_names, mpcg_event_names,
			MPCG_NR_STATES, MPCG_NR_EVENTS, mpcg_fsm,
			mpcg_fsm_len, GFP_KERNEL);
	if (grp->fsm == NULL) {
		kfree(grp);
		return NULL;
	}

	fsm_newstate(grp->fsm, MPCG_STATE_RESET);
	fsm_settimer(grp->fsm, &grp->timer);

	grp->xid_skb =
		 __dev_alloc_skb(MPC_BUFSIZE_DEFAULT, GFP_ATOMIC | GFP_DMA);
	if (grp->xid_skb == NULL) {
		kfree_fsm(grp->fsm);
		kfree(grp);
		return NULL;
	}
	/*  base xid for all channels in group  */
	grp->xid_skb_data = grp->xid_skb->data;
	grp->xid_th = (struct th_header *)grp->xid_skb->data;
	skb_put_data(grp->xid_skb, &thnorm, TH_HEADER_LENGTH);

	grp->xid = (struct xid2 *)skb_tail_pointer(grp->xid_skb);
	skb_put_data(grp->xid_skb, &init_xid, XID2_LENGTH);
	grp->xid->xid2_adj_id = jiffies | 0xfff00000;
	grp->xid->xid2_sender_id = jiffies;

	grp->xid_id = skb_tail_pointer(grp->xid_skb);
	skb_put_data(grp->xid_skb, "VTAM", 4);

	grp->rcvd_xid_skb =
		__dev_alloc_skb(MPC_BUFSIZE_DEFAULT, GFP_ATOMIC|GFP_DMA);
	if (grp->rcvd_xid_skb == NULL) {
		kfree_fsm(grp->fsm);
		dev_kfree_skb(grp->xid_skb);
		kfree(grp);
		return NULL;
	}
	grp->rcvd_xid_data = grp->rcvd_xid_skb->data;
	grp->rcvd_xid_th = (struct th_header *)grp->rcvd_xid_skb->data;
	skb_put_data(grp->rcvd_xid_skb, &thnorm, TH_HEADER_LENGTH);
	grp->saved_xid2 = NULL;
	priv->xid = grp->xid;
	priv->mpcg = grp;
	return grp;
}

/*
 * The MPC Group Station FSM
 */

/*
 * MPC Group Station FSM actions
 * CTCM_PROTO_MPC only
 */

/*
 * NOP action for statemachines
 */
static void mpc_action_nop(fsm_instance *fi, int event, void *arg)
{
}

/*
 * invoked when the device transitions to dev_stopped
 * MPC will stop each individual channel if a single XID failure
 * occurs, or will intitiate all channels be stopped if a GROUP
 * level failure occurs.
 */
static void mpc_action_go_inop(fsm_instance *fi, int event, void *arg)
{
	struct net_device  *dev = arg;
	struct ctcm_priv    *priv;
	struct mpc_group *grp;
	struct channel *wch;

	CTCM_PR_DEBUG("Enter %s: %s\n",	__func__, dev->name);

	priv  = dev->ml_priv;
	grp =  priv->mpcg;
	grp->flow_off_called = 0;
	fsm_deltimer(&grp->timer);
	if (grp->channels_terminating)
			return;

	grp->channels_terminating = 1;
	grp->saved_state = fsm_getstate(grp->fsm);
	fsm_newstate(grp->fsm, MPCG_STATE_INOP);
	if (grp->saved_state > MPCG_STATE_XID7INITF)
		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
			"%s(%s): MPC GROUP INOPERATIVE",
				CTCM_FUNTAIL, dev->name);
	if ((grp->saved_state != MPCG_STATE_RESET) ||
		/* dealloc_channel has been called */
		(grp->port_persist == 0))
		fsm_deltimer(&priv->restart_timer);

	wch = priv->channel[CTCM_WRITE];

	switch (grp->saved_state) {
	case MPCG_STATE_RESET:
	case MPCG_STATE_INOP:
	case MPCG_STATE_XID2INITW:
	case MPCG_STATE_XID0IOWAIT:
	case MPCG_STATE_XID2INITX:
	case MPCG_STATE_XID7INITW:
	case MPCG_STATE_XID7INITX:
	case MPCG_STATE_XID0IOWAIX:
	case MPCG_STATE_XID7INITI:
	case MPCG_STATE_XID7INITZ:
	case MPCG_STATE_XID7INITF:
		break;
	case MPCG_STATE_FLOWC:
	case MPCG_STATE_READY:
	default:
		tasklet_hi_schedule(&wch->ch_disc_tasklet);
	}

	grp->xid2_tgnum = 0;
	grp->group_max_buflen = 0;  /*min of all received */
	grp->outstanding_xid2 = 0;
	grp->outstanding_xid7 = 0;
	grp->outstanding_xid7_p2 = 0;
	grp->saved_xid2 = NULL;
	grp->xidnogood = 0;
	grp->changed_side = 0;

	grp->rcvd_xid_skb->data = grp->rcvd_xid_data;
	skb_reset_tail_pointer(grp->rcvd_xid_skb);
	grp->rcvd_xid_skb->len = 0;
	grp->rcvd_xid_th = (struct th_header *)grp->rcvd_xid_skb->data;
	skb_put_data(grp->rcvd_xid_skb, &thnorm, TH_HEADER_LENGTH);

	if (grp->send_qllc_disc == 1) {
		grp->send_qllc_disc = 0;
		mpc_send_qllc_discontact(dev);
	}

	/* DO NOT issue DEV_EVENT_STOP directly out of this code */
	/* This can result in INOP of VTAM PU due to halting of  */
	/* outstanding IO which causes a sense to be returned	 */
	/* Only about 3 senses are allowed and then IOS/VTAM will*/
	/* become unreachable without manual intervention	 */
	if ((grp->port_persist == 1) || (grp->alloc_called)) {
		grp->alloc_called = 0;
		fsm_deltimer(&priv->restart_timer);
		fsm_addtimer(&priv->restart_timer, 500, DEV_EVENT_RESTART, dev);
		fsm_newstate(grp->fsm, MPCG_STATE_RESET);
		if (grp->saved_state > MPCG_STATE_XID7INITF)
			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ALWAYS,
				"%s(%s): MPC GROUP RECOVERY SCHEDULED",
					CTCM_FUNTAIL, dev->name);
	} else {
		fsm_deltimer(&priv->restart_timer);
		fsm_addtimer(&priv->restart_timer, 500, DEV_EVENT_STOP, dev);
		fsm_newstate(grp->fsm, MPCG_STATE_RESET);
		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ALWAYS,
			"%s(%s): NO MPC GROUP RECOVERY ATTEMPTED",
						CTCM_FUNTAIL, dev->name);
	}
}

/*
 * Handle mpc group  action timeout.
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 *
 * fi		An instance of an mpc_group fsm.
 * event	The event, just happened.
 * arg		Generic pointer, casted from net_device * upon call.
 */
static void mpc_action_timeout(fsm_instance *fi, int event, void *arg)
{
	struct net_device *dev = arg;
	struct ctcm_priv *priv;
	struct mpc_group *grp;
	struct channel *wch;
	struct channel *rch;

	priv = dev->ml_priv;
	grp = priv->mpcg;
	wch = priv->channel[CTCM_WRITE];
	rch = priv->channel[CTCM_READ];

	switch (fsm_getstate(grp->fsm)) {
	case MPCG_STATE_XID2INITW:
		/* Unless there is outstanding IO on the  */
		/* channel just return and wait for ATTN  */
		/* interrupt to begin XID negotiations	  */
		if ((fsm_getstate(rch->fsm) == CH_XID0_PENDING) &&
		   (fsm_getstate(wch->fsm) == CH_XID0_PENDING))
			break;
		fallthrough;
	default:
		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
	}

	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
			"%s: dev=%s exit",
			CTCM_FUNTAIL, dev->name);
	return;
}

/*
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 */
void mpc_action_discontact(fsm_instance *fi, int event, void *arg)
{
	struct mpcg_info   *mpcginfo   = arg;
	struct channel	   *ch	       = mpcginfo->ch;
	struct net_device  *dev;
	struct ctcm_priv   *priv;
	struct mpc_group   *grp;

	if (ch) {
		dev = ch->netdev;
		if (dev) {
			priv = dev->ml_priv;
			if (priv) {
				CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
					"%s: %s: %s\n",
					CTCM_FUNTAIL, dev->name, ch->id);
				grp = priv->mpcg;
				grp->send_qllc_disc = 1;
				fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
			}
		}
	}

	return;
}

/*
 * MPC Group Station - not part of FSM
 * CTCM_PROTO_MPC only
 * called from add_channel in ctcm_main.c
 */
void mpc_action_send_discontact(unsigned long thischan)
{
	int rc;
	struct channel	*ch = (struct channel *)thischan;
	unsigned long	saveflags = 0;

	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
	rc = ccw_device_start(ch->cdev, &ch->ccw[15], 0, 0xff, 0);
	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);

	if (rc != 0) {
		ctcm_ccw_check_rc(ch, rc, (char *)__func__);
	}

	return;
}


/*
 * helper function of mpc FSM
 * CTCM_PROTO_MPC only
 * mpc_action_rcvd_xid7
*/
static int mpc_validate_xid(struct mpcg_info *mpcginfo)
{
	struct channel	   *ch	 = mpcginfo->ch;
	struct net_device  *dev  = ch->netdev;
	struct ctcm_priv   *priv = dev->ml_priv;
	struct mpc_group   *grp  = priv->mpcg;
	struct xid2	   *xid  = mpcginfo->xid;
	int	rc	 = 0;
	__u64	our_id   = 0;
	__u64   their_id = 0;
	int	len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;

	CTCM_PR_DEBUG("Enter %s: xid=%p\n", __func__, xid);

	if (xid == NULL) {
		rc = 1;
		/* XID REJECTED: xid == NULL */
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): xid = NULL",
				CTCM_FUNTAIL, ch->id);
			goto done;
	}

	CTCM_D3_DUMP((char *)xid, XID2_LENGTH);

	/*the received direction should be the opposite of ours  */
	if (((CHANNEL_DIRECTION(ch->flags) == CTCM_READ) ? XID2_WRITE_SIDE :
				XID2_READ_SIDE) != xid->xid2_dlc_type) {
		rc = 2;
		/* XID REJECTED: r/w channel pairing mismatch */
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): r/w channel pairing mismatch",
				CTCM_FUNTAIL, ch->id);
			goto done;
	}

	if (xid->xid2_dlc_type == XID2_READ_SIDE) {
		CTCM_PR_DEBUG("%s: grpmaxbuf:%d xid2buflen:%d\n", __func__,
				grp->group_max_buflen, xid->xid2_buf_len);

		if (grp->group_max_buflen == 0 || grp->group_max_buflen >
						xid->xid2_buf_len - len)
			grp->group_max_buflen = xid->xid2_buf_len - len;
	}

	if (grp->saved_xid2 == NULL) {
		grp->saved_xid2 =
			(struct xid2 *)skb_tail_pointer(grp->rcvd_xid_skb);

		skb_put_data(grp->rcvd_xid_skb, xid, XID2_LENGTH);
		grp->rcvd_xid_skb->data = grp->rcvd_xid_data;

		skb_reset_tail_pointer(grp->rcvd_xid_skb);
		grp->rcvd_xid_skb->len = 0;

		/* convert two 32 bit numbers into 1 64 bit for id compare */
		our_id = (__u64)priv->xid->xid2_adj_id;
		our_id = our_id << 32;
		our_id = our_id + priv->xid->xid2_sender_id;
		their_id = (__u64)xid->xid2_adj_id;
		their_id = their_id << 32;
		their_id = their_id + xid->xid2_sender_id;
		/* lower id assume the xside role */
		if (our_id < their_id) {
			grp->roll = XSIDE;
			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
				"%s(%s): WE HAVE LOW ID - TAKE XSIDE",
					CTCM_FUNTAIL, ch->id);
		} else {
			grp->roll = YSIDE;
			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
				"%s(%s): WE HAVE HIGH ID - TAKE YSIDE",
					CTCM_FUNTAIL, ch->id);
		}

	} else {
		if (xid->xid2_flag4 != grp->saved_xid2->xid2_flag4) {
			rc = 3;
			/* XID REJECTED: xid flag byte4 mismatch */
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): xid flag byte4 mismatch",
					CTCM_FUNTAIL, ch->id);
		}
		if (xid->xid2_flag2 == 0x40) {
			rc = 4;
			/* XID REJECTED - xid NOGOOD */
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): xid NOGOOD",
					CTCM_FUNTAIL, ch->id);
		}
		if (xid->xid2_adj_id != grp->saved_xid2->xid2_adj_id) {
			rc = 5;
			/* XID REJECTED - Adjacent Station ID Mismatch */
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): Adjacent Station ID Mismatch",
					CTCM_FUNTAIL, ch->id);
		}
		if (xid->xid2_sender_id != grp->saved_xid2->xid2_sender_id) {
			rc = 6;
			/* XID REJECTED - Sender Address Mismatch */
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): Sender Address Mismatch",
					CTCM_FUNTAIL, ch->id);
		}
	}
done:
	if (rc) {
		dev_warn(&dev->dev,
			"The XID used in the MPC protocol is not valid, "
			"rc = %d\n", rc);
		priv->xid->xid2_flag2 = 0x40;
		grp->saved_xid2->xid2_flag2 = 0x40;
	}

	return rc;
}

/*
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 */
static void mpc_action_side_xid(fsm_instance *fsm, void *arg, int side)
{
	struct channel *ch = arg;
	int rc = 0;
	int gotlock = 0;
	unsigned long saveflags = 0;	/* avoids compiler warning with
					   spin_unlock_irqrestore */

	CTCM_PR_DEBUG("Enter %s: cp=%i ch=0x%p id=%s\n",
			__func__, smp_processor_id(), ch, ch->id);

	if (ctcm_checkalloc_buffer(ch))
					goto done;

	/*
	 * skb data-buffer referencing:
	 */
	ch->trans_skb->data = ch->trans_skb_data;
	skb_reset_tail_pointer(ch->trans_skb);
	ch->trans_skb->len = 0;
	/* result of the previous 3 statements is NOT always
	 * already set after ctcm_checkalloc_buffer
	 * because of possible reuse of the trans_skb
	 */
	memset(ch->trans_skb->data, 0, 16);
	ch->rcvd_xid_th =  (struct th_header *)ch->trans_skb_data;
	/* check is main purpose here: */
	skb_put(ch->trans_skb, TH_HEADER_LENGTH);
	ch->rcvd_xid = (struct xid2 *)skb_tail_pointer(ch->trans_skb);
	/* check is main purpose here: */
	skb_put(ch->trans_skb, XID2_LENGTH);
	ch->rcvd_xid_id = skb_tail_pointer(ch->trans_skb);
	/* cleanup back to startpoint */
	ch->trans_skb->data = ch->trans_skb_data;
	skb_reset_tail_pointer(ch->trans_skb);
	ch->trans_skb->len = 0;

	/* non-checking rewrite of above skb data-buffer referencing: */
	/*
	memset(ch->trans_skb->data, 0, 16);
	ch->rcvd_xid_th =  (struct th_header *)ch->trans_skb_data;
	ch->rcvd_xid = (struct xid2 *)(ch->trans_skb_data + TH_HEADER_LENGTH);
	ch->rcvd_xid_id = ch->trans_skb_data + TH_HEADER_LENGTH + XID2_LENGTH;
	 */

	ch->ccw[8].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
	ch->ccw[8].count	= 0;
	ch->ccw[8].cda		= 0x00;

	if (!(ch->xid_th && ch->xid && ch->xid_id))
		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_INFO,
			"%s(%s): xid_th=%p, xid=%p, xid_id=%p",
			CTCM_FUNTAIL, ch->id, ch->xid_th, ch->xid, ch->xid_id);

	if (side == XSIDE) {
		/* mpc_action_xside_xid */
		if (ch->xid_th == NULL)
				goto done;
		ch->ccw[9].cmd_code	= CCW_CMD_WRITE;
		ch->ccw[9].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
		ch->ccw[9].count	= TH_HEADER_LENGTH;
		ch->ccw[9].cda		= virt_to_phys(ch->xid_th);

		if (ch->xid == NULL)
				goto done;
		ch->ccw[10].cmd_code	= CCW_CMD_WRITE;
		ch->ccw[10].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
		ch->ccw[10].count	= XID2_LENGTH;
		ch->ccw[10].cda		= virt_to_phys(ch->xid);

		ch->ccw[11].cmd_code	= CCW_CMD_READ;
		ch->ccw[11].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
		ch->ccw[11].count	= TH_HEADER_LENGTH;
		ch->ccw[11].cda		= virt_to_phys(ch->rcvd_xid_th);

		ch->ccw[12].cmd_code	= CCW_CMD_READ;
		ch->ccw[12].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
		ch->ccw[12].count	= XID2_LENGTH;
		ch->ccw[12].cda		= virt_to_phys(ch->rcvd_xid);

		ch->ccw[13].cmd_code	= CCW_CMD_READ;
		ch->ccw[13].cda		= virt_to_phys(ch->rcvd_xid_id);

	} else { /* side == YSIDE : mpc_action_yside_xid */
		ch->ccw[9].cmd_code	= CCW_CMD_READ;
		ch->ccw[9].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
		ch->ccw[9].count	= TH_HEADER_LENGTH;
		ch->ccw[9].cda		= virt_to_phys(ch->rcvd_xid_th);

		ch->ccw[10].cmd_code	= CCW_CMD_READ;
		ch->ccw[10].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
		ch->ccw[10].count	= XID2_LENGTH;
		ch->ccw[10].cda		= virt_to_phys(ch->rcvd_xid);

		if (ch->xid_th == NULL)
				goto done;
		ch->ccw[11].cmd_code	= CCW_CMD_WRITE;
		ch->ccw[11].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
		ch->ccw[11].count	= TH_HEADER_LENGTH;
		ch->ccw[11].cda		= virt_to_phys(ch->xid_th);

		if (ch->xid == NULL)
				goto done;
		ch->ccw[12].cmd_code	= CCW_CMD_WRITE;
		ch->ccw[12].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
		ch->ccw[12].count	= XID2_LENGTH;
		ch->ccw[12].cda		= virt_to_phys(ch->xid);

		if (ch->xid_id == NULL)
				goto done;
		ch->ccw[13].cmd_code	= CCW_CMD_WRITE;
		ch->ccw[13].cda		= virt_to_phys(ch->xid_id);

	}
	ch->ccw[13].flags	= CCW_FLAG_SLI | CCW_FLAG_CC;
	ch->ccw[13].count	= 4;

	ch->ccw[14].cmd_code	= CCW_CMD_NOOP;
	ch->ccw[14].flags	= CCW_FLAG_SLI;
	ch->ccw[14].count	= 0;
	ch->ccw[14].cda		= 0;

	CTCM_CCW_DUMP((char *)&ch->ccw[8], sizeof(struct ccw1) * 7);
	CTCM_D3_DUMP((char *)ch->xid_th, TH_HEADER_LENGTH);
	CTCM_D3_DUMP((char *)ch->xid, XID2_LENGTH);
	CTCM_D3_DUMP((char *)ch->xid_id, 4);

	if (!in_hardirq()) {
			 /* Such conditional locking is a known problem for
			  * sparse because its static undeterministic.
			  * Warnings should be ignored here. */
		spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
		gotlock = 1;
	}

	fsm_addtimer(&ch->timer, 5000 , CTC_EVENT_TIMER, ch);
	rc = ccw_device_start(ch->cdev, &ch->ccw[8], 0, 0xff, 0);

	if (gotlock)	/* see remark above about conditional locking */
		spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);

	if (rc != 0) {
		ctcm_ccw_check_rc(ch, rc,
				(side == XSIDE) ? "x-side XID" : "y-side XID");
	}

done:
	CTCM_PR_DEBUG("Exit %s: ch=0x%p id=%s\n",
				__func__, ch, ch->id);
	return;

}

/*
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 */
static void mpc_action_xside_xid(fsm_instance *fsm, int event, void *arg)
{
	mpc_action_side_xid(fsm, arg, XSIDE);
}

/*
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 */
static void mpc_action_yside_xid(fsm_instance *fsm, int event, void *arg)
{
	mpc_action_side_xid(fsm, arg, YSIDE);
}

/*
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 */
static void mpc_action_doxid0(fsm_instance *fsm, int event, void *arg)
{
	struct channel	   *ch   = arg;
	struct net_device  *dev  = ch->netdev;
	struct ctcm_priv   *priv = dev->ml_priv;
	struct mpc_group   *grp  = priv->mpcg;

	CTCM_PR_DEBUG("Enter %s: cp=%i ch=0x%p id=%s\n",
			__func__, smp_processor_id(), ch, ch->id);

	if (ch->xid == NULL) {
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): ch->xid == NULL",
				CTCM_FUNTAIL, dev->name);
		return;
	}

	fsm_newstate(ch->fsm, CH_XID0_INPROGRESS);

	ch->xid->xid2_option =	XID2_0;

	switch (fsm_getstate(grp->fsm)) {
	case MPCG_STATE_XID2INITW:
	case MPCG_STATE_XID2INITX:
		ch->ccw[8].cmd_code = CCW_CMD_SENSE_CMD;
		break;
	case MPCG_STATE_XID0IOWAIT:
	case MPCG_STATE_XID0IOWAIX:
		ch->ccw[8].cmd_code = CCW_CMD_WRITE_CTL;
		break;
	}

	fsm_event(grp->fsm, MPCG_EVENT_DOIO, ch);

	return;
}

/*
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
*/
static void mpc_action_doxid7(fsm_instance *fsm, int event, void *arg)
{
	struct net_device *dev = arg;
	struct ctcm_priv  *priv = dev->ml_priv;
	struct mpc_group  *grp  = NULL;
	int direction;
	int send = 0;

	if (priv)
		grp = priv->mpcg;
	if (grp == NULL)
		return;

	for (direction = CTCM_READ; direction <= CTCM_WRITE; direction++) {
		struct channel *ch = priv->channel[direction];
		struct xid2 *thisxid = ch->xid;
		ch->xid_skb->data = ch->xid_skb_data;
		skb_reset_tail_pointer(ch->xid_skb);
		ch->xid_skb->len = 0;
		thisxid->xid2_option = XID2_7;
		send = 0;

		/* xid7 phase 1 */
		if (grp->outstanding_xid7_p2 > 0) {
			if (grp->roll == YSIDE) {
				if (fsm_getstate(ch->fsm) == CH_XID7_PENDING1) {
					fsm_newstate(ch->fsm, CH_XID7_PENDING2);
					ch->ccw[8].cmd_code = CCW_CMD_SENSE_CMD;
					skb_put_data(ch->xid_skb, &thdummy,
						     TH_HEADER_LENGTH);
					send = 1;
				}
			} else if (fsm_getstate(ch->fsm) < CH_XID7_PENDING2) {
					fsm_newstate(ch->fsm, CH_XID7_PENDING2);
					ch->ccw[8].cmd_code = CCW_CMD_WRITE_CTL;
					skb_put_data(ch->xid_skb, &thnorm,
						     TH_HEADER_LENGTH);
					send = 1;
			}
		} else {
			/* xid7 phase 2 */
			if (grp->roll == YSIDE) {
				if (fsm_getstate(ch->fsm) < CH_XID7_PENDING4) {
					fsm_newstate(ch->fsm, CH_XID7_PENDING4);
					skb_put_data(ch->xid_skb, &thnorm,
						     TH_HEADER_LENGTH);
					ch->ccw[8].cmd_code = CCW_CMD_WRITE_CTL;
					send = 1;
				}
			} else if (fsm_getstate(ch->fsm) == CH_XID7_PENDING3) {
				fsm_newstate(ch->fsm, CH_XID7_PENDING4);
				ch->ccw[8].cmd_code = CCW_CMD_SENSE_CMD;
				skb_put_data(ch->xid_skb, &thdummy,
					     TH_HEADER_LENGTH);
				send = 1;
			}
		}

		if (send)
			fsm_event(grp->fsm, MPCG_EVENT_DOIO, ch);
	}

	return;
}

/*
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 */
static void mpc_action_rcvd_xid0(fsm_instance *fsm, int event, void *arg)
{

	struct mpcg_info   *mpcginfo  = arg;
	struct channel	   *ch   = mpcginfo->ch;
	struct net_device  *dev  = ch->netdev;
	struct ctcm_priv   *priv = dev->ml_priv;
	struct mpc_group   *grp  = priv->mpcg;

	CTCM_PR_DEBUG("%s: ch-id:%s xid2:%i xid7:%i xidt_p2:%i \n",
			__func__, ch->id, grp->outstanding_xid2,
			grp->outstanding_xid7, grp->outstanding_xid7_p2);

	if (fsm_getstate(ch->fsm) < CH_XID7_PENDING)
		fsm_newstate(ch->fsm, CH_XID7_PENDING);

	grp->outstanding_xid2--;
	grp->outstanding_xid7++;
	grp->outstanding_xid7_p2++;

	/* must change state before validating xid to */
	/* properly handle interim interrupts received*/
	switch (fsm_getstate(grp->fsm)) {
	case MPCG_STATE_XID2INITW:
		fsm_newstate(grp->fsm, MPCG_STATE_XID2INITX);
		mpc_validate_xid(mpcginfo);
		break;
	case MPCG_STATE_XID0IOWAIT:
		fsm_newstate(grp->fsm, MPCG_STATE_XID0IOWAIX);
		mpc_validate_xid(mpcginfo);
		break;
	case MPCG_STATE_XID2INITX:
		if (grp->outstanding_xid2 == 0) {
			fsm_newstate(grp->fsm, MPCG_STATE_XID7INITW);
			mpc_validate_xid(mpcginfo);
			fsm_event(grp->fsm, MPCG_EVENT_XID2DONE, dev);
		}
		break;
	case MPCG_STATE_XID0IOWAIX:
		if (grp->outstanding_xid2 == 0) {
			fsm_newstate(grp->fsm, MPCG_STATE_XID7INITI);
			mpc_validate_xid(mpcginfo);
			fsm_event(grp->fsm, MPCG_EVENT_XID2DONE, dev);
		}
		break;
	}

	CTCM_PR_DEBUG("ctcmpc:%s() %s xid2:%i xid7:%i xidt_p2:%i \n",
		__func__, ch->id, grp->outstanding_xid2,
		grp->outstanding_xid7, grp->outstanding_xid7_p2);
	CTCM_PR_DEBUG("ctcmpc:%s() %s grpstate: %s chanstate: %s \n",
		__func__, ch->id,
		fsm_getstate_str(grp->fsm), fsm_getstate_str(ch->fsm));
	return;

}


/*
 * MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 */
static void mpc_action_rcvd_xid7(fsm_instance *fsm, int event, void *arg)
{
	struct mpcg_info   *mpcginfo   = arg;
	struct channel	   *ch	       = mpcginfo->ch;
	struct net_device  *dev        = ch->netdev;
	struct ctcm_priv   *priv    = dev->ml_priv;
	struct mpc_group   *grp     = priv->mpcg;

	CTCM_PR_DEBUG("Enter %s: cp=%i ch=0x%p id=%s\n",
		__func__, smp_processor_id(), ch, ch->id);
	CTCM_PR_DEBUG("%s: outstanding_xid7: %i, outstanding_xid7_p2: %i\n",
		__func__, grp->outstanding_xid7, grp->outstanding_xid7_p2);

	grp->outstanding_xid7--;
	ch->xid_skb->data = ch->xid_skb_data;
	skb_reset_tail_pointer(ch->xid_skb);
	ch->xid_skb->len = 0;

	switch (fsm_getstate(grp->fsm)) {
	case MPCG_STATE_XID7INITI:
		fsm_newstate(grp->fsm, MPCG_STATE_XID7INITZ);
		mpc_validate_xid(mpcginfo);
		break;
	case MPCG_STATE_XID7INITW:
		fsm_newstate(grp->fsm, MPCG_STATE_XID7INITX);
		mpc_validate_xid(mpcginfo);
		break;
	case MPCG_STATE_XID7INITZ:
	case MPCG_STATE_XID7INITX:
		if (grp->outstanding_xid7 == 0) {
			if (grp->outstanding_xid7_p2 > 0) {
				grp->outstanding_xid7 =
					grp->outstanding_xid7_p2;
				grp->outstanding_xid7_p2 = 0;
			} else
				fsm_newstate(grp->fsm, MPCG_STATE_XID7INITF);

			mpc_validate_xid(mpcginfo);
			fsm_event(grp->fsm, MPCG_EVENT_XID7DONE, dev);
			break;
		}
		mpc_validate_xid(mpcginfo);
		break;
	}
	return;
}

/*
 * mpc_action helper of an MPC Group Station FSM action
 * CTCM_PROTO_MPC only
 */
static int mpc_send_qllc_discontact(struct net_device *dev)
{
	struct sk_buff   *skb;
	struct qllc      *qllcptr;
	struct ctcm_priv *priv = dev->ml_priv;
	struct mpc_group *grp = priv->mpcg;

	CTCM_PR_DEBUG("%s: GROUP STATE: %s\n",
		__func__, mpcg_state_names[grp->saved_state]);

	switch (grp->saved_state) {
	/*
	 * establish conn callback function is
	 * preferred method to report failure
	 */
	case MPCG_STATE_XID0IOWAIT:
	case MPCG_STATE_XID0IOWAIX:
	case MPCG_STATE_XID7INITI:
	case MPCG_STATE_XID7INITZ:
	case MPCG_STATE_XID2INITW:
	case MPCG_STATE_XID2INITX:
	case MPCG_STATE_XID7INITW:
	case MPCG_STATE_XID7INITX:
		if (grp->estconnfunc) {
			grp->estconnfunc(grp->port_num, -1, 0);
			grp->estconnfunc = NULL;
			break;
		}
		fallthrough;
	case MPCG_STATE_FLOWC:
	case MPCG_STATE_READY:
		grp->send_qllc_disc = 2;

		skb = __dev_alloc_skb(sizeof(struct qllc), GFP_ATOMIC);
		if (skb == NULL) {
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): skb allocation error",
						CTCM_FUNTAIL, dev->name);
			priv->stats.rx_dropped++;
			return -ENOMEM;
		}

		qllcptr = skb_put(skb, sizeof(struct qllc));
		qllcptr->qllc_address = 0xcc;
		qllcptr->qllc_commands = 0x03;

		if (skb_headroom(skb) < 4) {
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): skb_headroom error",
						CTCM_FUNTAIL, dev->name);
			dev_kfree_skb_any(skb);
			return -ENOMEM;
		}

		*((__u32 *)skb_push(skb, 4)) =
			priv->channel[CTCM_READ]->pdu_seq;
		priv->channel[CTCM_READ]->pdu_seq++;
		CTCM_PR_DBGDATA("ctcmpc: %s ToDCM_pdu_seq= %08x\n",
				__func__, priv->channel[CTCM_READ]->pdu_seq);

		/* receipt of CC03 resets anticipated sequence number on
		      receiving side */
		priv->channel[CTCM_READ]->pdu_seq = 0x00;
		skb_reset_mac_header(skb);
		skb->dev = dev;
		skb->protocol = htons(ETH_P_SNAP);
		skb->ip_summed = CHECKSUM_UNNECESSARY;

		CTCM_D3_DUMP(skb->data, (sizeof(struct qllc) + 4));

		netif_rx(skb);
		break;
	default:
		break;

	}

	return 0;
}
/* --- This is the END my friend --- */