// 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 pr_fmt(fmt) "ctcm: " fmt

#include <linux/export.h>
#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>
#include <linux/bitops.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include <linux/moduleparam.h>
#include <asm/ccwdev.h>
#include <asm/ccwgroup.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) {
                        scnprintf(addr, sizeof(addr), "%16.16llx", (__u64)rptr);

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

                scnprintf(tbuf, sizeof(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) {
                                scnprintf(tdup, sizeof(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;
                        strscpy(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) {
                        scnprintf(tdup, sizeof(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) {
                        scnprintf(tdup, sizeof(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;

        scnprintf(device, sizeof(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);
        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_obj(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_obj(struct mpc_group);
        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_dma32(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_dma32(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_dma32(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_dma32(ch->rcvd_xid);

                ch->ccw[13].cmd_code    = CCW_CMD_READ;
                ch->ccw[13].cda         = virt_to_dma32(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_dma32(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_dma32(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_dma32(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_dma32(ch->xid);

                if (ch->xid_id == NULL)
                                goto done;
                ch->ccw[13].cmd_code    = CCW_CMD_WRITE;
                ch->ccw[13].cda         = virt_to_dma32(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 --- */