Merge branch 'sched/urgent'

[linux-2.6/x86.git] / drivers / s390 / net / ctcm_fsms.c

/*
 * drivers/s390/net/ctcm_fsms.c
 *
 * Copyright IBM Corp. 2001, 2007
 * Authors:     Fritz Elfert (felfert@millenux.com)
 *              Peter Tiedemann (ptiedem@de.ibm.com)
 *      MPC additions :
 *              Belinda Thompson (belindat@us.ibm.com)
 *              Andy Richter (richtera@us.ibm.com)
 */

#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/bitops.h>

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

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

#include <linux/io.h>
#include <asm/ccwdev.h>
#include <asm/ccwgroup.h>
#include <linux/uaccess.h>

#include <asm/idals.h>

#include "fsm.h"

#include "ctcm_dbug.h"
#include "ctcm_main.h"
#include "ctcm_fsms.h"

const char *dev_state_names[] = {
        [DEV_STATE_STOPPED]             = "Stopped",
        [DEV_STATE_STARTWAIT_RXTX]      = "StartWait RXTX",
        [DEV_STATE_STARTWAIT_RX]        = "StartWait RX",
        [DEV_STATE_STARTWAIT_TX]        = "StartWait TX",
        [DEV_STATE_STOPWAIT_RXTX]       = "StopWait RXTX",
        [DEV_STATE_STOPWAIT_RX]         = "StopWait RX",
        [DEV_STATE_STOPWAIT_TX]         = "StopWait TX",
        [DEV_STATE_RUNNING]             = "Running",
};

const char *dev_event_names[] = {
        [DEV_EVENT_START]       = "Start",
        [DEV_EVENT_STOP]        = "Stop",
        [DEV_EVENT_RXUP]        = "RX up",
        [DEV_EVENT_TXUP]        = "TX up",
        [DEV_EVENT_RXDOWN]      = "RX down",
        [DEV_EVENT_TXDOWN]      = "TX down",
        [DEV_EVENT_RESTART]     = "Restart",
};

const char *ctc_ch_event_names[] = {
        [CTC_EVENT_IO_SUCCESS]  = "ccw_device success",
        [CTC_EVENT_IO_EBUSY]    = "ccw_device busy",
        [CTC_EVENT_IO_ENODEV]   = "ccw_device enodev",
        [CTC_EVENT_IO_UNKNOWN]  = "ccw_device unknown",
        [CTC_EVENT_ATTNBUSY]    = "Status ATTN & BUSY",
        [CTC_EVENT_ATTN]        = "Status ATTN",
        [CTC_EVENT_BUSY]        = "Status BUSY",
        [CTC_EVENT_UC_RCRESET]  = "Unit check remote reset",
        [CTC_EVENT_UC_RSRESET]  = "Unit check remote system reset",
        [CTC_EVENT_UC_TXTIMEOUT] = "Unit check TX timeout",
        [CTC_EVENT_UC_TXPARITY] = "Unit check TX parity",
        [CTC_EVENT_UC_HWFAIL]   = "Unit check Hardware failure",
        [CTC_EVENT_UC_RXPARITY] = "Unit check RX parity",
        [CTC_EVENT_UC_ZERO]     = "Unit check ZERO",
        [CTC_EVENT_UC_UNKNOWN]  = "Unit check Unknown",
        [CTC_EVENT_SC_UNKNOWN]  = "SubChannel check Unknown",
        [CTC_EVENT_MC_FAIL]     = "Machine check failure",
        [CTC_EVENT_MC_GOOD]     = "Machine check operational",
        [CTC_EVENT_IRQ]         = "IRQ normal",
        [CTC_EVENT_FINSTAT]     = "IRQ final",
        [CTC_EVENT_TIMER]       = "Timer",
        [CTC_EVENT_START]       = "Start",
        [CTC_EVENT_STOP]        = "Stop",
        /*
        * additional MPC events
        */
        [CTC_EVENT_SEND_XID]    = "XID Exchange",
        [CTC_EVENT_RSWEEP_TIMER] = "MPC Group Sweep Timer",
};

const char *ctc_ch_state_names[] = {
        [CTC_STATE_IDLE]        = "Idle",
        [CTC_STATE_STOPPED]     = "Stopped",
        [CTC_STATE_STARTWAIT]   = "StartWait",
        [CTC_STATE_STARTRETRY]  = "StartRetry",
        [CTC_STATE_SETUPWAIT]   = "SetupWait",
        [CTC_STATE_RXINIT]      = "RX init",
        [CTC_STATE_TXINIT]      = "TX init",
        [CTC_STATE_RX]          = "RX",
        [CTC_STATE_TX]          = "TX",
        [CTC_STATE_RXIDLE]      = "RX idle",
        [CTC_STATE_TXIDLE]      = "TX idle",
        [CTC_STATE_RXERR]       = "RX error",
        [CTC_STATE_TXERR]       = "TX error",
        [CTC_STATE_TERM]        = "Terminating",
        [CTC_STATE_DTERM]       = "Restarting",
        [CTC_STATE_NOTOP]       = "Not operational",
        /*
        * additional MPC states
        */
        [CH_XID0_PENDING]       = "Pending XID0 Start",
        [CH_XID0_INPROGRESS]    = "In XID0 Negotiations ",
        [CH_XID7_PENDING]       = "Pending XID7 P1 Start",
        [CH_XID7_PENDING1]      = "Active XID7 P1 Exchange ",
        [CH_XID7_PENDING2]      = "Pending XID7 P2 Start ",
        [CH_XID7_PENDING3]      = "Active XID7 P2 Exchange ",
        [CH_XID7_PENDING4]      = "XID7 Complete - Pending READY ",
};

static void ctcm_action_nop(fsm_instance *fi, int event, void *arg);

/*
 * ----- static ctcm actions for channel statemachine -----
 *
*/
static void chx_txdone(fsm_instance *fi, int event, void *arg);
static void chx_rx(fsm_instance *fi, int event, void *arg);
static void chx_rxidle(fsm_instance *fi, int event, void *arg);
static void chx_firstio(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_setmode(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_start(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_haltio(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_stopped(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_stop(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_fail(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_setuperr(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_restart(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_rxiniterr(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_rxinitfail(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_rxdisc(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_txiniterr(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_txretry(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_iofatal(fsm_instance *fi, int event, void *arg);

/*
 * ----- static ctcmpc actions for ctcmpc channel statemachine -----
 *
*/
static void ctcmpc_chx_txdone(fsm_instance *fi, int event, void *arg);
static void ctcmpc_chx_rx(fsm_instance *fi, int event, void *arg);
static void ctcmpc_chx_firstio(fsm_instance *fi, int event, void *arg);
/* shared :
static void ctcm_chx_setmode(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_start(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_haltio(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_stopped(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_stop(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_fail(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_setuperr(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_restart(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_rxiniterr(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_rxinitfail(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_rxdisc(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_txiniterr(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_txretry(fsm_instance *fi, int event, void *arg);
static void ctcm_chx_iofatal(fsm_instance *fi, int event, void *arg);
*/
static void ctcmpc_chx_attn(fsm_instance *fsm, int event, void *arg);
static void ctcmpc_chx_attnbusy(fsm_instance *, int, void *);
static void ctcmpc_chx_resend(fsm_instance *, int, void *);
static void ctcmpc_chx_send_sweep(fsm_instance *fsm, int event, void *arg);

/**
 * Check return code of a preceding ccw_device call, halt_IO etc...
 *
 * ch   :       The channel, the error belongs to.
 * Returns the error code (!= 0) to inspect.
 */
void ctcm_ccw_check_rc(struct channel *ch, int rc, char *msg)
{
        CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
                "%s(%s): %s: %04x\n",
                CTCM_FUNTAIL, ch->id, msg, rc);
        switch (rc) {
        case -EBUSY:
                pr_info("%s: The communication peer is busy\n",
                        ch->id);
                fsm_event(ch->fsm, CTC_EVENT_IO_EBUSY, ch);
                break;
        case -ENODEV:
                pr_err("%s: The specified target device is not valid\n",
                       ch->id);
                fsm_event(ch->fsm, CTC_EVENT_IO_ENODEV, ch);
                break;
        default:
                pr_err("An I/O operation resulted in error %04x\n",
                       rc);
                fsm_event(ch->fsm, CTC_EVENT_IO_UNKNOWN, ch);
        }
}

void ctcm_purge_skb_queue(struct sk_buff_head *q)
{
        struct sk_buff *skb;

        CTCM_DBF_TEXT(TRACE, CTC_DBF_DEBUG, __func__);

        while ((skb = skb_dequeue(q))) {
                atomic_dec(&skb->users);
                dev_kfree_skb_any(skb);
        }
}

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

/*
 * Actions for channel - statemachines.
 */

/**
 * Normal data has been send. Free the corresponding
 * skb (it's in io_queue), reset dev->tbusy and
 * revert to idle state.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void chx_txdone(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;
        struct sk_buff *skb;
        int first = 1;
        int i;
        unsigned long duration;
        struct timespec done_stamp = current_kernel_time(); /* xtime */

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

        duration =
            (done_stamp.tv_sec - ch->prof.send_stamp.tv_sec) * 1000000 +
            (done_stamp.tv_nsec - ch->prof.send_stamp.tv_nsec) / 1000;
        if (duration > ch->prof.tx_time)
                ch->prof.tx_time = duration;

        if (ch->irb->scsw.cmd.count != 0)
                CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
                        "%s(%s): TX not complete, remaining %d bytes",
                             CTCM_FUNTAIL, dev->name, ch->irb->scsw.cmd.count);
        fsm_deltimer(&ch->timer);
        while ((skb = skb_dequeue(&ch->io_queue))) {
                priv->stats.tx_packets++;
                priv->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
                if (first) {
                        priv->stats.tx_bytes += 2;
                        first = 0;
                }
                atomic_dec(&skb->users);
                dev_kfree_skb_irq(skb);
        }
        spin_lock(&ch->collect_lock);
        clear_normalized_cda(&ch->ccw[4]);
        if (ch->collect_len > 0) {
                int rc;

                if (ctcm_checkalloc_buffer(ch)) {
                        spin_unlock(&ch->collect_lock);
                        return;
                }
                ch->trans_skb->data = ch->trans_skb_data;
                skb_reset_tail_pointer(ch->trans_skb);
                ch->trans_skb->len = 0;
                if (ch->prof.maxmulti < (ch->collect_len + 2))
                        ch->prof.maxmulti = ch->collect_len + 2;
                if (ch->prof.maxcqueue < skb_queue_len(&ch->collect_queue))
                        ch->prof.maxcqueue = skb_queue_len(&ch->collect_queue);
                *((__u16 *)skb_put(ch->trans_skb, 2)) = ch->collect_len + 2;
                i = 0;
                while ((skb = skb_dequeue(&ch->collect_queue))) {
                        skb_copy_from_linear_data(skb,
                                skb_put(ch->trans_skb, skb->len), skb->len);
                        priv->stats.tx_packets++;
                        priv->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
                        atomic_dec(&skb->users);
                        dev_kfree_skb_irq(skb);
                        i++;
                }
                ch->collect_len = 0;
                spin_unlock(&ch->collect_lock);
                ch->ccw[1].count = ch->trans_skb->len;
                fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
                ch->prof.send_stamp = current_kernel_time(); /* xtime */
                rc = ccw_device_start(ch->cdev, &ch->ccw[0],
                                                (unsigned long)ch, 0xff, 0);
                ch->prof.doios_multi++;
                if (rc != 0) {
                        priv->stats.tx_dropped += i;
                        priv->stats.tx_errors += i;
                        fsm_deltimer(&ch->timer);
                        ctcm_ccw_check_rc(ch, rc, "chained TX");
                }
        } else {
                spin_unlock(&ch->collect_lock);
                fsm_newstate(fi, CTC_STATE_TXIDLE);
        }
        ctcm_clear_busy_do(dev);
}

/**
 * Initial data is sent.
 * Notify device statemachine that we are up and
 * running.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
void ctcm_chx_txidle(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;

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

        fsm_deltimer(&ch->timer);
        fsm_newstate(fi, CTC_STATE_TXIDLE);
        fsm_event(priv->fsm, DEV_EVENT_TXUP, ch->netdev);
}

/**
 * Got normal data, check for sanity, queue it up, allocate new buffer
 * trigger bottom half, and initiate next read.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void chx_rx(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;
        int len = ch->max_bufsize - ch->irb->scsw.cmd.count;
        struct sk_buff *skb = ch->trans_skb;
        __u16 block_len = *((__u16 *)skb->data);
        int check_len;
        int rc;

        fsm_deltimer(&ch->timer);
        if (len < 8) {
                CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
                        "%s(%s): got packet with length %d < 8\n",
                                        CTCM_FUNTAIL, dev->name, len);
                priv->stats.rx_dropped++;
                priv->stats.rx_length_errors++;
                                                goto again;
        }
        if (len > ch->max_bufsize) {
                CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
                        "%s(%s): got packet with length %d > %d\n",
                                CTCM_FUNTAIL, dev->name, len, ch->max_bufsize);
                priv->stats.rx_dropped++;
                priv->stats.rx_length_errors++;
                                                goto again;
        }

        /*
         * VM TCP seems to have a bug sending 2 trailing bytes of garbage.
         */
        switch (ch->protocol) {
        case CTCM_PROTO_S390:
        case CTCM_PROTO_OS390:
                check_len = block_len + 2;
                break;
        default:
                check_len = block_len;
                break;
        }
        if ((len < block_len) || (len > check_len)) {
                CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
                        "%s(%s): got block length %d != rx length %d\n",
                                CTCM_FUNTAIL, dev->name, block_len, len);
                if (do_debug)
                        ctcmpc_dump_skb(skb, 0);

                *((__u16 *)skb->data) = len;
                priv->stats.rx_dropped++;
                priv->stats.rx_length_errors++;
                                                goto again;
        }
        if (block_len > 2) {
                *((__u16 *)skb->data) = block_len - 2;
                ctcm_unpack_skb(ch, skb);
        }
 again:
        skb->data = ch->trans_skb_data;
        skb_reset_tail_pointer(skb);
        skb->len = 0;
        if (ctcm_checkalloc_buffer(ch))
                return;
        ch->ccw[1].count = ch->max_bufsize;
        rc = ccw_device_start(ch->cdev, &ch->ccw[0],
                                        (unsigned long)ch, 0xff, 0);
        if (rc != 0)
                ctcm_ccw_check_rc(ch, rc, "normal RX");
}

/**
 * Initialize connection by sending a __u16 of value 0.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void chx_firstio(fsm_instance *fi, int event, void *arg)
{
        int rc;
        struct channel *ch = arg;
        int fsmstate = fsm_getstate(fi);

        CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
                "%s(%s) : %02x",
                CTCM_FUNTAIL, ch->id, fsmstate);

        ch->sense_rc = 0;       /* reset unit check report control */
        if (fsmstate == CTC_STATE_TXIDLE)
                CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
                        "%s(%s): remote side issued READ?, init.\n",
                                CTCM_FUNTAIL, ch->id);
        fsm_deltimer(&ch->timer);
        if (ctcm_checkalloc_buffer(ch))
                return;
        if ((fsmstate == CTC_STATE_SETUPWAIT) &&
            (ch->protocol == CTCM_PROTO_OS390)) {
                /* OS/390 resp. z/OS */
                if (CHANNEL_DIRECTION(ch->flags) == CTCM_READ) {
                        *((__u16 *)ch->trans_skb->data) = CTCM_INITIAL_BLOCKLEN;
                        fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC,
                                     CTC_EVENT_TIMER, ch);
                        chx_rxidle(fi, event, arg);
                } else {
                        struct net_device *dev = ch->netdev;
                        struct ctcm_priv *priv = dev->ml_priv;
                        fsm_newstate(fi, CTC_STATE_TXIDLE);
                        fsm_event(priv->fsm, DEV_EVENT_TXUP, dev);
                }
                return;
        }
        /*
         * Don't setup a timer for receiving the initial RX frame
         * if in compatibility mode, since VM TCP delays the initial
         * frame until it has some data to send.
         */
        if ((CHANNEL_DIRECTION(ch->flags) == CTCM_WRITE) ||
            (ch->protocol != CTCM_PROTO_S390))
                fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);

        *((__u16 *)ch->trans_skb->data) = CTCM_INITIAL_BLOCKLEN;
        ch->ccw[1].count = 2;   /* Transfer only length */

        fsm_newstate(fi, (CHANNEL_DIRECTION(ch->flags) == CTCM_READ)
                     ? CTC_STATE_RXINIT : CTC_STATE_TXINIT);
        rc = ccw_device_start(ch->cdev, &ch->ccw[0],
                                        (unsigned long)ch, 0xff, 0);
        if (rc != 0) {
                fsm_deltimer(&ch->timer);
                fsm_newstate(fi, CTC_STATE_SETUPWAIT);
                ctcm_ccw_check_rc(ch, rc, "init IO");
        }
        /*
         * If in compatibility mode since we don't setup a timer, we
         * also signal RX channel up immediately. This enables us
         * to send packets early which in turn usually triggers some
         * reply from VM TCP which brings up the RX channel to it's
         * final state.
         */
        if ((CHANNEL_DIRECTION(ch->flags) == CTCM_READ) &&
            (ch->protocol == CTCM_PROTO_S390)) {
                struct net_device *dev = ch->netdev;
                struct ctcm_priv *priv = dev->ml_priv;
                fsm_event(priv->fsm, DEV_EVENT_RXUP, dev);
        }
}

/**
 * Got initial data, check it. If OK,
 * notify device statemachine that we are up and
 * running.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void chx_rxidle(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;
        __u16 buflen;
        int rc;

        fsm_deltimer(&ch->timer);
        buflen = *((__u16 *)ch->trans_skb->data);
        CTCM_PR_DEBUG("%s: %s: Initial RX count = %d\n",
                        __func__, dev->name, buflen);

        if (buflen >= CTCM_INITIAL_BLOCKLEN) {
                if (ctcm_checkalloc_buffer(ch))
                        return;
                ch->ccw[1].count = ch->max_bufsize;
                fsm_newstate(fi, CTC_STATE_RXIDLE);
                rc = ccw_device_start(ch->cdev, &ch->ccw[0],
                                                (unsigned long)ch, 0xff, 0);
                if (rc != 0) {
                        fsm_newstate(fi, CTC_STATE_RXINIT);
                        ctcm_ccw_check_rc(ch, rc, "initial RX");
                } else
                        fsm_event(priv->fsm, DEV_EVENT_RXUP, dev);
        } else {
                CTCM_PR_DEBUG("%s: %s: Initial RX count %d not %d\n",
                                __func__, dev->name,
                                        buflen, CTCM_INITIAL_BLOCKLEN);
                chx_firstio(fi, event, arg);
        }
}

/**
 * Set channel into extended mode.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_setmode(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        int rc;
        unsigned long saveflags = 0;
        int timeout = CTCM_TIME_5_SEC;

        fsm_deltimer(&ch->timer);
        if (IS_MPC(ch)) {
                timeout = 1500;
                CTCM_PR_DEBUG("enter %s: cp=%i ch=0x%p id=%s\n",
                                __func__, smp_processor_id(), ch, ch->id);
        }
        fsm_addtimer(&ch->timer, timeout, CTC_EVENT_TIMER, ch);
        fsm_newstate(fi, CTC_STATE_SETUPWAIT);
        CTCM_CCW_DUMP((char *)&ch->ccw[6], sizeof(struct ccw1) * 2);

        if (event == CTC_EVENT_TIMER)   /* only for timer not yet locked */
                spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
                        /* Such conditional locking is undeterministic in
                         * static view. => ignore sparse warnings here. */

        rc = ccw_device_start(ch->cdev, &ch->ccw[6],
                                        (unsigned long)ch, 0xff, 0);
        if (event == CTC_EVENT_TIMER)   /* see above comments */
                spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
        if (rc != 0) {
                fsm_deltimer(&ch->timer);
                fsm_newstate(fi, CTC_STATE_STARTWAIT);
                ctcm_ccw_check_rc(ch, rc, "set Mode");
        } else
                ch->retry = 0;
}

/**
 * Setup channel.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_start(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch      = arg;
        unsigned long saveflags;
        int rc;

        CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO, "%s(%s): %s",
                CTCM_FUNTAIL, ch->id,
                (CHANNEL_DIRECTION(ch->flags) == CTCM_READ) ? "RX" : "TX");

        if (ch->trans_skb != NULL) {
                clear_normalized_cda(&ch->ccw[1]);
                dev_kfree_skb(ch->trans_skb);
                ch->trans_skb = NULL;
        }
        if (CHANNEL_DIRECTION(ch->flags) == CTCM_READ) {
                ch->ccw[1].cmd_code = CCW_CMD_READ;
                ch->ccw[1].flags = CCW_FLAG_SLI;
                ch->ccw[1].count = 0;
        } else {
                ch->ccw[1].cmd_code = CCW_CMD_WRITE;
                ch->ccw[1].flags = CCW_FLAG_SLI | CCW_FLAG_CC;
                ch->ccw[1].count = 0;
        }
        if (ctcm_checkalloc_buffer(ch)) {
                CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
                        "%s(%s): %s trans_skb alloc delayed "
                        "until first transfer",
                        CTCM_FUNTAIL, ch->id,
                        (CHANNEL_DIRECTION(ch->flags) == CTCM_READ) ?
                                "RX" : "TX");
        }
        ch->ccw[0].cmd_code = CCW_CMD_PREPARE;
        ch->ccw[0].flags = CCW_FLAG_SLI | CCW_FLAG_CC;
        ch->ccw[0].count = 0;
        ch->ccw[0].cda = 0;
        ch->ccw[2].cmd_code = CCW_CMD_NOOP;     /* jointed CE + DE */
        ch->ccw[2].flags = CCW_FLAG_SLI;
        ch->ccw[2].count = 0;
        ch->ccw[2].cda = 0;
        memcpy(&ch->ccw[3], &ch->ccw[0], sizeof(struct ccw1) * 3);
        ch->ccw[4].cda = 0;
        ch->ccw[4].flags &= ~CCW_FLAG_IDA;

        fsm_newstate(fi, CTC_STATE_STARTWAIT);
        fsm_addtimer(&ch->timer, 1000, CTC_EVENT_TIMER, ch);
        spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
        rc = ccw_device_halt(ch->cdev, (unsigned long)ch);
        spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
        if (rc != 0) {
                if (rc != -EBUSY)
                        fsm_deltimer(&ch->timer);
                ctcm_ccw_check_rc(ch, rc, "initial HaltIO");
        }
}

/**
 * Shutdown a channel.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_haltio(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        unsigned long saveflags = 0;
        int rc;
        int oldstate;

        fsm_deltimer(&ch->timer);
        if (IS_MPC(ch))
                fsm_deltimer(&ch->sweep_timer);

        fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);

        if (event == CTC_EVENT_STOP)    /* only for STOP not yet locked */
                spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
                        /* Such conditional locking is undeterministic in
                         * static view. => ignore sparse warnings here. */
        oldstate = fsm_getstate(fi);
        fsm_newstate(fi, CTC_STATE_TERM);
        rc = ccw_device_halt(ch->cdev, (unsigned long)ch);

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

        if (rc != 0 && rc != -EBUSY) {
                fsm_deltimer(&ch->timer);
                if (event != CTC_EVENT_STOP) {
                        fsm_newstate(fi, oldstate);
                        ctcm_ccw_check_rc(ch, rc, (char *)__func__);
                }
        }
}

/**
 * Cleanup helper for chx_fail and chx_stopped
 * cleanup channels queue and notify interface statemachine.
 *
 * fi           An instance of a channel statemachine.
 * state        The next state (depending on caller).
 * ch           The channel to operate on.
 */
static void ctcm_chx_cleanup(fsm_instance *fi, int state,
                struct channel *ch)
{
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;

        CTCM_DBF_TEXT_(SETUP, CTC_DBF_NOTICE,
                        "%s(%s): %s[%d]\n",
                        CTCM_FUNTAIL, dev->name, ch->id, state);

        fsm_deltimer(&ch->timer);
        if (IS_MPC(ch))
                fsm_deltimer(&ch->sweep_timer);

        fsm_newstate(fi, state);
        if (state == CTC_STATE_STOPPED && ch->trans_skb != NULL) {
                clear_normalized_cda(&ch->ccw[1]);
                dev_kfree_skb_any(ch->trans_skb);
                ch->trans_skb = NULL;
        }

        ch->th_seg = 0x00;
        ch->th_seq_num = 0x00;
        if (CHANNEL_DIRECTION(ch->flags) == CTCM_READ) {
                skb_queue_purge(&ch->io_queue);
                fsm_event(priv->fsm, DEV_EVENT_RXDOWN, dev);
        } else {
                ctcm_purge_skb_queue(&ch->io_queue);
                if (IS_MPC(ch))
                        ctcm_purge_skb_queue(&ch->sweep_queue);
                spin_lock(&ch->collect_lock);
                ctcm_purge_skb_queue(&ch->collect_queue);
                ch->collect_len = 0;
                spin_unlock(&ch->collect_lock);
                fsm_event(priv->fsm, DEV_EVENT_TXDOWN, dev);
        }
}

/**
 * A channel has successfully been halted.
 * Cleanup it's queue and notify interface statemachine.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_stopped(fsm_instance *fi, int event, void *arg)
{
        ctcm_chx_cleanup(fi, CTC_STATE_STOPPED, arg);
}

/**
 * A stop command from device statemachine arrived and we are in
 * not operational mode. Set state to stopped.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_stop(fsm_instance *fi, int event, void *arg)
{
        fsm_newstate(fi, CTC_STATE_STOPPED);
}

/**
 * A machine check for no path, not operational status or gone device has
 * happened.
 * Cleanup queue and notify interface statemachine.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_fail(fsm_instance *fi, int event, void *arg)
{
        ctcm_chx_cleanup(fi, CTC_STATE_NOTOP, arg);
}

/**
 * Handle error during setup of channel.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_setuperr(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;

        /*
         * Special case: Got UC_RCRESET on setmode.
         * This means that remote side isn't setup. In this case
         * simply retry after some 10 secs...
         */
        if ((fsm_getstate(fi) == CTC_STATE_SETUPWAIT) &&
            ((event == CTC_EVENT_UC_RCRESET) ||
             (event == CTC_EVENT_UC_RSRESET))) {
                fsm_newstate(fi, CTC_STATE_STARTRETRY);
                fsm_deltimer(&ch->timer);
                fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
                if (!IS_MPC(ch) &&
                    (CHANNEL_DIRECTION(ch->flags) == CTCM_READ)) {
                        int rc = ccw_device_halt(ch->cdev, (unsigned long)ch);
                        if (rc != 0)
                                ctcm_ccw_check_rc(ch, rc,
                                        "HaltIO in chx_setuperr");
                }
                return;
        }

        CTCM_DBF_TEXT_(ERROR, CTC_DBF_CRIT,
                "%s(%s) : %s error during %s channel setup state=%s\n",
                CTCM_FUNTAIL, dev->name, ctc_ch_event_names[event],
                (CHANNEL_DIRECTION(ch->flags) == CTCM_READ) ? "RX" : "TX",
                fsm_getstate_str(fi));

        if (CHANNEL_DIRECTION(ch->flags) == CTCM_READ) {
                fsm_newstate(fi, CTC_STATE_RXERR);
                fsm_event(priv->fsm, DEV_EVENT_RXDOWN, dev);
        } else {
                fsm_newstate(fi, CTC_STATE_TXERR);
                fsm_event(priv->fsm, DEV_EVENT_TXDOWN, dev);
        }
}

/**
 * Restart a channel after an error.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_restart(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        unsigned long saveflags = 0;
        int oldstate;
        int rc;

        CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
                "%s: %s[%d] of %s\n",
                        CTCM_FUNTAIL, ch->id, event, dev->name);

        fsm_deltimer(&ch->timer);

        fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
        oldstate = fsm_getstate(fi);
        fsm_newstate(fi, CTC_STATE_STARTWAIT);
        if (event == CTC_EVENT_TIMER)   /* only for timer not yet locked */
                spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
                        /* Such conditional locking is a known problem for
                         * sparse because its undeterministic in static view.
                         * Warnings should be ignored here. */
        rc = ccw_device_halt(ch->cdev, (unsigned long)ch);
        if (event == CTC_EVENT_TIMER)
                spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
        if (rc != 0) {
                if (rc != -EBUSY) {
                    fsm_deltimer(&ch->timer);
                    fsm_newstate(fi, oldstate);
                }
                ctcm_ccw_check_rc(ch, rc, "HaltIO in ctcm_chx_restart");
        }
}

/**
 * Handle error during RX initial handshake (exchange of
 * 0-length block header)
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_rxiniterr(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;

        if (event == CTC_EVENT_TIMER) {
                if (!IS_MPCDEV(dev))
                        /* TODO : check if MPC deletes timer somewhere */
                        fsm_deltimer(&ch->timer);
                if (ch->retry++ < 3)
                        ctcm_chx_restart(fi, event, arg);
                else {
                        fsm_newstate(fi, CTC_STATE_RXERR);
                        fsm_event(priv->fsm, DEV_EVENT_RXDOWN, dev);
                }
        } else {
                CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
                        "%s(%s): %s in %s", CTCM_FUNTAIL, ch->id,
                        ctc_ch_event_names[event], fsm_getstate_str(fi));

                dev_warn(&dev->dev,
                        "Initialization failed with RX/TX init handshake "
                        "error %s\n", ctc_ch_event_names[event]);
        }
}

/**
 * Notify device statemachine if we gave up initialization
 * of RX channel.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_rxinitfail(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;

        CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
                        "%s(%s): RX %s busy, init. fail",
                                CTCM_FUNTAIL, dev->name, ch->id);
        fsm_newstate(fi, CTC_STATE_RXERR);
        fsm_event(priv->fsm, DEV_EVENT_RXDOWN, dev);
}

/**
 * Handle RX Unit check remote reset (remote disconnected)
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_rxdisc(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct channel *ch2;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;

        CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
                        "%s: %s: remote disconnect - re-init ...",
                                CTCM_FUNTAIL, dev->name);
        fsm_deltimer(&ch->timer);
        /*
         * Notify device statemachine
         */
        fsm_event(priv->fsm, DEV_EVENT_RXDOWN, dev);
        fsm_event(priv->fsm, DEV_EVENT_TXDOWN, dev);

        fsm_newstate(fi, CTC_STATE_DTERM);
        ch2 = priv->channel[CTCM_WRITE];
        fsm_newstate(ch2->fsm, CTC_STATE_DTERM);

        ccw_device_halt(ch->cdev, (unsigned long)ch);
        ccw_device_halt(ch2->cdev, (unsigned long)ch2);
}

/**
 * Handle error during TX channel initialization.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_txiniterr(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;

        if (event == CTC_EVENT_TIMER) {
                fsm_deltimer(&ch->timer);
                if (ch->retry++ < 3)
                        ctcm_chx_restart(fi, event, arg);
                else {
                        fsm_newstate(fi, CTC_STATE_TXERR);
                        fsm_event(priv->fsm, DEV_EVENT_TXDOWN, dev);
                }
        } else {
                CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
                        "%s(%s): %s in %s", CTCM_FUNTAIL, ch->id,
                        ctc_ch_event_names[event], fsm_getstate_str(fi));

                dev_warn(&dev->dev,
                        "Initialization failed with RX/TX init handshake "
                        "error %s\n", ctc_ch_event_names[event]);
        }
}

/**
 * Handle TX timeout by retrying operation.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_txretry(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;
        struct sk_buff *skb;

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

        fsm_deltimer(&ch->timer);
        if (ch->retry++ > 3) {
                struct mpc_group *gptr = priv->mpcg;
                CTCM_DBF_TEXT_(TRACE, CTC_DBF_INFO,
                                "%s: %s: retries exceeded",
                                        CTCM_FUNTAIL, ch->id);
                fsm_event(priv->fsm, DEV_EVENT_TXDOWN, dev);
                /* call restart if not MPC or if MPC and mpcg fsm is ready.
                        use gptr as mpc indicator */
                if (!(gptr && (fsm_getstate(gptr->fsm) != MPCG_STATE_READY)))
                        ctcm_chx_restart(fi, event, arg);
                                goto done;
        }

        CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
                        "%s : %s: retry %d",
                                CTCM_FUNTAIL, ch->id, ch->retry);
        skb = skb_peek(&ch->io_queue);
        if (skb) {
                int rc = 0;
                unsigned long saveflags = 0;
                clear_normalized_cda(&ch->ccw[4]);
                ch->ccw[4].count = skb->len;
                if (set_normalized_cda(&ch->ccw[4], skb->data)) {
                        CTCM_DBF_TEXT_(TRACE, CTC_DBF_INFO,
                                "%s: %s: IDAL alloc failed",
                                                CTCM_FUNTAIL, ch->id);
                        fsm_event(priv->fsm, DEV_EVENT_TXDOWN, dev);
                        ctcm_chx_restart(fi, event, arg);
                                goto done;
                }
                fsm_addtimer(&ch->timer, 1000, CTC_EVENT_TIMER, ch);
                if (event == CTC_EVENT_TIMER) /* for TIMER not yet locked */
                        spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
                        /* Such conditional locking is a known problem for
                         * sparse because its undeterministic in static view.
                         * Warnings should be ignored here. */
                if (do_debug_ccw)
                        ctcmpc_dumpit((char *)&ch->ccw[3],
                                        sizeof(struct ccw1) * 3);

                rc = ccw_device_start(ch->cdev, &ch->ccw[3],
                                                (unsigned long)ch, 0xff, 0);
                if (event == CTC_EVENT_TIMER)
                        spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev),
                                        saveflags);
                if (rc != 0) {
                        fsm_deltimer(&ch->timer);
                        ctcm_ccw_check_rc(ch, rc, "TX in chx_txretry");
                        ctcm_purge_skb_queue(&ch->io_queue);
                }
        }
done:
        return;
}

/**
 * Handle fatal errors during an I/O command.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcm_chx_iofatal(fsm_instance *fi, int event, void *arg)
{
        struct channel *ch = arg;
        struct net_device *dev = ch->netdev;
        struct ctcm_priv *priv = dev->ml_priv;
        int rd = CHANNEL_DIRECTION(ch->flags);

        fsm_deltimer(&ch->timer);
        CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
                "%s: %s: %s unrecoverable channel error",
                        CTCM_FUNTAIL, ch->id, rd == CTCM_READ ? "RX" : "TX");

        if (IS_MPC(ch)) {
                priv->stats.tx_dropped++;
                priv->stats.tx_errors++;
        }
        if (rd == CTCM_READ) {
                fsm_newstate(fi, CTC_STATE_RXERR);
                fsm_event(priv->fsm, DEV_EVENT_RXDOWN, dev);
        } else {
                fsm_newstate(fi, CTC_STATE_TXERR);
                fsm_event(priv->fsm, DEV_EVENT_TXDOWN, dev);
        }
}

/*
 * The ctcm statemachine for a channel.
 */
const fsm_node ch_fsm[] = {
        { CTC_STATE_STOPPED,    CTC_EVENT_STOP,         ctcm_action_nop  },
        { CTC_STATE_STOPPED,    CTC_EVENT_START,        ctcm_chx_start  },
        { CTC_STATE_STOPPED,    CTC_EVENT_FINSTAT,      ctcm_action_nop  },
        { CTC_STATE_STOPPED,    CTC_EVENT_MC_FAIL,      ctcm_action_nop  },

        { CTC_STATE_NOTOP,      CTC_EVENT_STOP,         ctcm_chx_stop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_FINSTAT,      ctcm_action_nop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_MC_FAIL,      ctcm_action_nop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_MC_GOOD,      ctcm_chx_start  },

        { CTC_STATE_STARTWAIT,  CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_FINSTAT,      ctcm_chx_setmode  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_TIMER,        ctcm_chx_setuperr  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_STARTRETRY, CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_STARTRETRY, CTC_EVENT_TIMER,        ctcm_chx_setmode  },
        { CTC_STATE_STARTRETRY, CTC_EVENT_FINSTAT,      ctcm_action_nop  },
        { CTC_STATE_STARTRETRY, CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_SETUPWAIT,  CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_FINSTAT,      chx_firstio  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_UC_RCRESET,   ctcm_chx_setuperr  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_TIMER,        ctcm_chx_setmode  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_RXINIT,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_RXINIT,     CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_RXINIT,     CTC_EVENT_FINSTAT,      chx_rxidle  },
        { CTC_STATE_RXINIT,     CTC_EVENT_UC_RCRESET,   ctcm_chx_rxiniterr  },
        { CTC_STATE_RXINIT,     CTC_EVENT_UC_RSRESET,   ctcm_chx_rxiniterr  },
        { CTC_STATE_RXINIT,     CTC_EVENT_TIMER,        ctcm_chx_rxiniterr  },
        { CTC_STATE_RXINIT,     CTC_EVENT_ATTNBUSY,     ctcm_chx_rxinitfail  },
        { CTC_STATE_RXINIT,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_RXINIT,     CTC_EVENT_UC_ZERO,      chx_firstio  },
        { CTC_STATE_RXINIT,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_RXIDLE,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_FINSTAT,      chx_rx  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_UC_RCRESET,   ctcm_chx_rxdisc  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_UC_ZERO,      chx_rx  },

        { CTC_STATE_TXINIT,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TXINIT,     CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_TXINIT,     CTC_EVENT_FINSTAT,      ctcm_chx_txidle  },
        { CTC_STATE_TXINIT,     CTC_EVENT_UC_RCRESET,   ctcm_chx_txiniterr  },
        { CTC_STATE_TXINIT,     CTC_EVENT_UC_RSRESET,   ctcm_chx_txiniterr  },
        { CTC_STATE_TXINIT,     CTC_EVENT_TIMER,        ctcm_chx_txiniterr  },
        { CTC_STATE_TXINIT,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_TXINIT,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_TXIDLE,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_FINSTAT,      chx_firstio  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_UC_RCRESET,   ctcm_action_nop  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_UC_RSRESET,   ctcm_action_nop  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_TERM,       CTC_EVENT_STOP,         ctcm_action_nop  },
        { CTC_STATE_TERM,       CTC_EVENT_START,        ctcm_chx_restart  },
        { CTC_STATE_TERM,       CTC_EVENT_FINSTAT,      ctcm_chx_stopped  },
        { CTC_STATE_TERM,       CTC_EVENT_UC_RCRESET,   ctcm_action_nop  },
        { CTC_STATE_TERM,       CTC_EVENT_UC_RSRESET,   ctcm_action_nop  },
        { CTC_STATE_TERM,       CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_DTERM,      CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_DTERM,      CTC_EVENT_START,        ctcm_chx_restart  },
        { CTC_STATE_DTERM,      CTC_EVENT_FINSTAT,      ctcm_chx_setmode  },
        { CTC_STATE_DTERM,      CTC_EVENT_UC_RCRESET,   ctcm_action_nop  },
        { CTC_STATE_DTERM,      CTC_EVENT_UC_RSRESET,   ctcm_action_nop  },
        { CTC_STATE_DTERM,      CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_TX,         CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TX,         CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_TX,         CTC_EVENT_FINSTAT,      chx_txdone  },
        { CTC_STATE_TX,         CTC_EVENT_UC_RCRESET,   ctcm_chx_txretry  },
        { CTC_STATE_TX,         CTC_EVENT_UC_RSRESET,   ctcm_chx_txretry  },
        { CTC_STATE_TX,         CTC_EVENT_TIMER,        ctcm_chx_txretry  },
        { CTC_STATE_TX,         CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_TX,         CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_RXERR,      CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TXERR,      CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TXERR,      CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_RXERR,      CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
};

int ch_fsm_len = ARRAY_SIZE(ch_fsm);

/*
 * MPC actions for mpc channel statemachine
 * handling of MPC protocol requires extra
 * statemachine and actions which are prefixed ctcmpc_ .
 * The ctc_ch_states and ctc_ch_state_names,
 * ctc_ch_events and ctc_ch_event_names share the ctcm definitions
 * which are expanded by some elements.
 */

/*
 * Actions for mpc channel statemachine.
 */

/**
 * Normal data has been send. Free the corresponding
 * skb (it's in io_queue), reset dev->tbusy and
 * revert to idle state.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcmpc_chx_txdone(fsm_instance *fi, 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;
        struct sk_buff          *skb;
        int             first = 1;
        int             i;
        __u32           data_space;
        unsigned long   duration;
        struct sk_buff  *peekskb;
        int             rc;
        struct th_header *header;
        struct pdu      *p_header;
        struct timespec done_stamp = current_kernel_time(); /* xtime */

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

        duration =
                (done_stamp.tv_sec - ch->prof.send_stamp.tv_sec) * 1000000 +
                (done_stamp.tv_nsec - ch->prof.send_stamp.tv_nsec) / 1000;
        if (duration > ch->prof.tx_time)
                ch->prof.tx_time = duration;

        if (ch->irb->scsw.cmd.count != 0)
                CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
                        "%s(%s): TX not complete, remaining %d bytes",
                             CTCM_FUNTAIL, dev->name, ch->irb->scsw.cmd.count);
        fsm_deltimer(&ch->timer);
        while ((skb = skb_dequeue(&ch->io_queue))) {
                priv->stats.tx_packets++;
                priv->stats.tx_bytes += skb->len - TH_HEADER_LENGTH;
                if (first) {
                        priv->stats.tx_bytes += 2;
                        first = 0;
                }
                atomic_dec(&skb->users);
                dev_kfree_skb_irq(skb);
        }
        spin_lock(&ch->collect_lock);
        clear_normalized_cda(&ch->ccw[4]);
        if ((ch->collect_len <= 0) || (grp->in_sweep != 0)) {
                spin_unlock(&ch->collect_lock);
                fsm_newstate(fi, CTC_STATE_TXIDLE);
                                goto done;
        }

        if (ctcm_checkalloc_buffer(ch)) {
                spin_unlock(&ch->collect_lock);
                                goto done;
        }
        ch->trans_skb->data = ch->trans_skb_data;
        skb_reset_tail_pointer(ch->trans_skb);
        ch->trans_skb->len = 0;
        if (ch->prof.maxmulti < (ch->collect_len + TH_HEADER_LENGTH))
                ch->prof.maxmulti = ch->collect_len + TH_HEADER_LENGTH;
        if (ch->prof.maxcqueue < skb_queue_len(&ch->collect_queue))
                ch->prof.maxcqueue = skb_queue_len(&ch->collect_queue);
        i = 0;
        p_header = NULL;
        data_space = grp->group_max_buflen - TH_HEADER_LENGTH;

        CTCM_PR_DBGDATA("%s: building trans_skb from collect_q"
                       " data_space:%04x\n",
                       __func__, data_space);

        while ((skb = skb_dequeue(&ch->collect_queue))) {
                memcpy(skb_put(ch->trans_skb, skb->len), skb->data, skb->len);
                p_header = (struct pdu *)
                        (skb_tail_pointer(ch->trans_skb) - skb->len);
                p_header->pdu_flag = 0x00;
                if (skb->protocol == ntohs(ETH_P_SNAP))
                        p_header->pdu_flag |= 0x60;
                else
                        p_header->pdu_flag |= 0x20;

                CTCM_PR_DBGDATA("%s: trans_skb len:%04x \n",
                                __func__, ch->trans_skb->len);
                CTCM_PR_DBGDATA("%s: pdu header and data for up"
                                " to 32 bytes sent to vtam\n", __func__);
                CTCM_D3_DUMP((char *)p_header, min_t(int, skb->len, 32));

                ch->collect_len -= skb->len;
                data_space -= skb->len;
                priv->stats.tx_packets++;
                priv->stats.tx_bytes += skb->len;
                atomic_dec(&skb->users);
                dev_kfree_skb_any(skb);
                peekskb = skb_peek(&ch->collect_queue);
                if (peekskb->len > data_space)
                        break;
                i++;
        }
        /* p_header points to the last one we handled */
        if (p_header)
                p_header->pdu_flag |= PDU_LAST; /*Say it's the last one*/
        header = kzalloc(TH_HEADER_LENGTH, gfp_type());
        if (!header) {
                spin_unlock(&ch->collect_lock);
                fsm_event(priv->mpcg->fsm, MPCG_EVENT_INOP, dev);
                                goto done;
        }
        header->th_ch_flag = TH_HAS_PDU;  /* Normal data */
        ch->th_seq_num++;
        header->th_seq_num = ch->th_seq_num;

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

        memcpy(skb_push(ch->trans_skb, TH_HEADER_LENGTH), header,
                TH_HEADER_LENGTH);      /* put the TH on the packet */

        kfree(header);

        CTCM_PR_DBGDATA("%s: trans_skb len:%04x \n",
                       __func__, ch->trans_skb->len);
        CTCM_PR_DBGDATA("%s: up-to-50 bytes of trans_skb "
                        "data to vtam from collect_q\n", __func__);
        CTCM_D3_DUMP((char *)ch->trans_skb->data,
                                min_t(int, ch->trans_skb->len, 50));

        spin_unlock(&ch->collect_lock);
        clear_normalized_cda(&ch->ccw[1]);
        if (set_normalized_cda(&ch->ccw[1], ch->trans_skb->data)) {
                dev_kfree_skb_any(ch->trans_skb);
                ch->trans_skb = NULL;
                CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
                        "%s: %s: IDAL alloc failed",
                                CTCM_FUNTAIL, ch->id);
                fsm_event(priv->mpcg->fsm, MPCG_EVENT_INOP, dev);
                return;
        }
        ch->ccw[1].count = ch->trans_skb->len;
        fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
        ch->prof.send_stamp = current_kernel_time(); /* xtime */
        if (do_debug_ccw)
                ctcmpc_dumpit((char *)&ch->ccw[0], sizeof(struct ccw1) * 3);
        rc = ccw_device_start(ch->cdev, &ch->ccw[0],
                                        (unsigned long)ch, 0xff, 0);
        ch->prof.doios_multi++;
        if (rc != 0) {
                priv->stats.tx_dropped += i;
                priv->stats.tx_errors += i;
                fsm_deltimer(&ch->timer);
                ctcm_ccw_check_rc(ch, rc, "chained TX");
        }
done:
        ctcm_clear_busy(dev);
        return;
}

/**
 * Got normal data, check for sanity, queue it up, allocate new buffer
 * trigger bottom half, and initiate next read.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcmpc_chx_rx(fsm_instance *fi, 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;
        struct sk_buff          *skb = ch->trans_skb;
        struct sk_buff          *new_skb;
        unsigned long           saveflags = 0;  /* avoids compiler warning */
        int len = ch->max_bufsize - ch->irb->scsw.cmd.count;

        CTCM_PR_DEBUG("%s: %s: cp:%i %s maxbuf : %04x, len: %04x\n",
                        CTCM_FUNTAIL, dev->name, smp_processor_id(),
                                ch->id, ch->max_bufsize, len);
        fsm_deltimer(&ch->timer);

        if (skb == NULL) {
                CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
                        "%s(%s): TRANS_SKB = NULL",
                                CTCM_FUNTAIL, dev->name);
                        goto again;
        }

        if (len < TH_HEADER_LENGTH) {
                CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
                                "%s(%s): packet length %d to short",
                                        CTCM_FUNTAIL, dev->name, len);
                priv->stats.rx_dropped++;
                priv->stats.rx_length_errors++;
        } else {
                /* must have valid th header or game over */
                __u32   block_len = len;
                len = TH_HEADER_LENGTH + XID2_LENGTH + 4;
                new_skb = __dev_alloc_skb(ch->max_bufsize, GFP_ATOMIC);

                if (new_skb == NULL) {
                        CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
                                "%s(%d): skb allocation failed",
                                                CTCM_FUNTAIL, dev->name);
                        fsm_event(priv->mpcg->fsm, MPCG_EVENT_INOP, dev);
                                        goto again;
                }
                switch (fsm_getstate(grp->fsm)) {
                case MPCG_STATE_RESET:
                case MPCG_STATE_INOP:
                        dev_kfree_skb_any(new_skb);
                        break;
                case MPCG_STATE_FLOWC:
                case MPCG_STATE_READY:
                        memcpy(skb_put(new_skb, block_len),
                                               skb->data, block_len);
                        skb_queue_tail(&ch->io_queue, new_skb);
                        tasklet_schedule(&ch->ch_tasklet);
                        break;
                default:
                        memcpy(skb_put(new_skb, len), skb->data, len);
                        skb_queue_tail(&ch->io_queue, new_skb);
                        tasklet_hi_schedule(&ch->ch_tasklet);
                        break;
                }
        }

again:
        switch (fsm_getstate(grp->fsm)) {
        int rc, dolock;
        case MPCG_STATE_FLOWC:
        case MPCG_STATE_READY:
                if (ctcm_checkalloc_buffer(ch))
                        break;
                ch->trans_skb->data = ch->trans_skb_data;
                skb_reset_tail_pointer(ch->trans_skb);
                ch->trans_skb->len = 0;
                ch->ccw[1].count = ch->max_bufsize;
                        if (do_debug_ccw)
                        ctcmpc_dumpit((char *)&ch->ccw[0],
                                        sizeof(struct ccw1) * 3);
                dolock = !in_irq();
                if (dolock)
                        spin_lock_irqsave(
                                get_ccwdev_lock(ch->cdev), saveflags);
                rc = ccw_device_start(ch->cdev, &ch->ccw[0],
                                                (unsigned long)ch, 0xff, 0);
                if (dolock) /* see remark about conditional locking */
                        spin_unlock_irqrestore(
                                get_ccwdev_lock(ch->cdev), saveflags);
                if (rc != 0)
                        ctcm_ccw_check_rc(ch, rc, "normal RX");
        default:
                break;
        }

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

}

/**
 * Initialize connection by sending a __u16 of value 0.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
static void ctcmpc_chx_firstio(fsm_instance *fi, int event, void *arg)
{
        struct channel          *ch = arg;
        struct net_device       *dev = ch->netdev;
        struct ctcm_priv        *priv = dev->ml_priv;
        struct mpc_group        *gptr = priv->mpcg;

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

        CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_INFO,
                        "%s: %s: chstate:%i, grpstate:%i, prot:%i\n",
                        CTCM_FUNTAIL, ch->id, fsm_getstate(fi),
                        fsm_getstate(gptr->fsm), ch->protocol);

        if (fsm_getstate(fi) == CTC_STATE_TXIDLE)
                MPC_DBF_DEV_NAME(TRACE, dev, "remote side issued READ? ");

        fsm_deltimer(&ch->timer);
        if (ctcm_checkalloc_buffer(ch))
                                goto done;

        switch (fsm_getstate(fi)) {
        case CTC_STATE_STARTRETRY:
        case CTC_STATE_SETUPWAIT:
                if (CHANNEL_DIRECTION(ch->flags) == CTCM_READ) {
                        ctcmpc_chx_rxidle(fi, event, arg);
                } else {
                        fsm_newstate(fi, CTC_STATE_TXIDLE);
                        fsm_event(priv->fsm, DEV_EVENT_TXUP, dev);
                }
                                goto done;
        default:
                break;
        };

        fsm_newstate(fi, (CHANNEL_DIRECTION(ch->flags) == CTCM_READ)
                     ? CTC_STATE_RXINIT : CTC_STATE_TXINIT);

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

/**
 * Got initial data, check it. If OK,
 * notify device statemachine that we are up and
 * running.
 *
 * fi           An instance of a channel statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from channel * upon call.
 */
void ctcmpc_chx_rxidle(fsm_instance *fi, 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;
        int rc;
        unsigned long saveflags = 0;    /* avoids compiler warning */

        fsm_deltimer(&ch->timer);
        CTCM_PR_DEBUG("%s: %s: %s: cp:%i, chstate:%i grpstate:%i\n",
                        __func__, ch->id, dev->name, smp_processor_id(),
                                fsm_getstate(fi), fsm_getstate(grp->fsm));

        fsm_newstate(fi, CTC_STATE_RXIDLE);
        /* XID processing complete */

        switch (fsm_getstate(grp->fsm)) {
        case MPCG_STATE_FLOWC:
        case MPCG_STATE_READY:
                if (ctcm_checkalloc_buffer(ch))
                                goto done;
                ch->trans_skb->data = ch->trans_skb_data;
                skb_reset_tail_pointer(ch->trans_skb);
                ch->trans_skb->len = 0;
                ch->ccw[1].count = ch->max_bufsize;
                CTCM_CCW_DUMP((char *)&ch->ccw[0], sizeof(struct ccw1) * 3);
                if (event == CTC_EVENT_START)
                        /* see remark about conditional locking */
                        spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
                rc = ccw_device_start(ch->cdev, &ch->ccw[0],
                                                (unsigned long)ch, 0xff, 0);
                if (event == CTC_EVENT_START)
                        spin_unlock_irqrestore(
                                        get_ccwdev_lock(ch->cdev), saveflags);
                if (rc != 0) {
                        fsm_newstate(fi, CTC_STATE_RXINIT);
                        ctcm_ccw_check_rc(ch, rc, "initial RX");
                                goto done;
                }
                break;
        default:
                break;
        }

        fsm_event(priv->fsm, DEV_EVENT_RXUP, dev);
done:
        return;
}

/*
 * ctcmpc channel FSM action
 * called from several points in ctcmpc_ch_fsm
 * ctcmpc only
 */
static void ctcmpc_chx_attn(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("%s(%s): %s(ch=0x%p), cp=%i, ChStat:%s, GrpStat:%s\n",
                __func__, dev->name, ch->id, ch, smp_processor_id(),
                        fsm_getstate_str(ch->fsm), fsm_getstate_str(grp->fsm));

        switch (fsm_getstate(grp->fsm)) {
        case MPCG_STATE_XID2INITW:
                /* ok..start yside xid exchanges */
                if (!ch->in_mpcgroup)
                        break;
                if (fsm_getstate(ch->fsm) ==  CH_XID0_PENDING) {
                        fsm_deltimer(&grp->timer);
                        fsm_addtimer(&grp->timer,
                                MPC_XID_TIMEOUT_VALUE,
                                MPCG_EVENT_TIMER, dev);
                        fsm_event(grp->fsm, MPCG_EVENT_XID0DO, ch);

                } else if (fsm_getstate(ch->fsm) < CH_XID7_PENDING1)
                        /* attn rcvd before xid0 processed via bh */
                        fsm_newstate(ch->fsm, CH_XID7_PENDING1);
                break;
        case MPCG_STATE_XID2INITX:
        case MPCG_STATE_XID0IOWAIT:
        case MPCG_STATE_XID0IOWAIX:
                /* attn rcvd before xid0 processed on ch
                but mid-xid0 processing for group    */
                if (fsm_getstate(ch->fsm) < CH_XID7_PENDING1)
                        fsm_newstate(ch->fsm, CH_XID7_PENDING1);
                break;
        case MPCG_STATE_XID7INITW:
        case MPCG_STATE_XID7INITX:
        case MPCG_STATE_XID7INITI:
        case MPCG_STATE_XID7INITZ:
                switch (fsm_getstate(ch->fsm)) {
                case CH_XID7_PENDING:
                        fsm_newstate(ch->fsm, CH_XID7_PENDING1);
                        break;
                case CH_XID7_PENDING2:
                        fsm_newstate(ch->fsm, CH_XID7_PENDING3);
                        break;
                }
                fsm_event(grp->fsm, MPCG_EVENT_XID7DONE, dev);
                break;
        }

        return;
}

/*
 * ctcmpc channel FSM action
 * called from one point in ctcmpc_ch_fsm
 * ctcmpc only
 */
static void ctcmpc_chx_attnbusy(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("%s(%s): %s\n  ChState:%s GrpState:%s\n",
                        __func__, dev->name, ch->id,
                        fsm_getstate_str(ch->fsm), fsm_getstate_str(grp->fsm));

        fsm_deltimer(&ch->timer);

        switch (fsm_getstate(grp->fsm)) {
        case MPCG_STATE_XID0IOWAIT:
                /* vtam wants to be primary.start yside xid exchanges*/
                /* only receive one attn-busy at a time so must not  */
                /* change state each time                            */
                grp->changed_side = 1;
                fsm_newstate(grp->fsm, MPCG_STATE_XID2INITW);
                break;
        case MPCG_STATE_XID2INITW:
                if (grp->changed_side == 1) {
                        grp->changed_side = 2;
                        break;
                }
                /* process began via call to establish_conn      */
                /* so must report failure instead of reverting   */
                /* back to ready-for-xid passive state           */
                if (grp->estconnfunc)
                                goto done;
                /* this attnbusy is NOT the result of xside xid  */
                /* collisions so yside must have been triggered  */
                /* by an ATTN that was not intended to start XID */
                /* processing. Revert back to ready-for-xid and  */
                /* wait for ATTN interrupt to signal xid start   */
                if (fsm_getstate(ch->fsm) == CH_XID0_INPROGRESS) {
                        fsm_newstate(ch->fsm, CH_XID0_PENDING) ;
                        fsm_deltimer(&grp->timer);
                                goto done;
                }
                fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
                                goto done;
        case MPCG_STATE_XID2INITX:
                /* XID2 was received before ATTN Busy for second
                   channel.Send yside xid for second channel.
                */
                if (grp->changed_side == 1) {
                        grp->changed_side = 2;
                        break;
                }
        case MPCG_STATE_XID0IOWAIX:
        case MPCG_STATE_XID7INITW:
        case MPCG_STATE_XID7INITX:
        case MPCG_STATE_XID7INITI:
        case MPCG_STATE_XID7INITZ:
        default:
                /* multiple attn-busy indicates too out-of-sync      */
                /* and they are certainly not being received as part */
                /* of valid mpc group negotiations..                 */
                fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
                                goto done;
        }

        if (grp->changed_side == 1) {
                fsm_deltimer(&grp->timer);
                fsm_addtimer(&grp->timer, MPC_XID_TIMEOUT_VALUE,
                             MPCG_EVENT_TIMER, dev);
        }
        if (ch->in_mpcgroup)
                fsm_event(grp->fsm, MPCG_EVENT_XID0DO, ch);
        else
                CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
                        "%s(%s): channel %s not added to group",
                                CTCM_FUNTAIL, dev->name, ch->id);

done:
        return;
}

/*
 * ctcmpc channel FSM action
 * called from several points in ctcmpc_ch_fsm
 * ctcmpc only
 */
static void ctcmpc_chx_resend(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;

        fsm_event(grp->fsm, MPCG_EVENT_XID0DO, ch);
        return;
}

/*
 * ctcmpc channel FSM action
 * called from several points in ctcmpc_ch_fsm
 * ctcmpc only
 */
static void ctcmpc_chx_send_sweep(fsm_instance *fsm, int event, void *arg)
{
        struct channel *ach = arg;
        struct net_device *dev = ach->netdev;
        struct ctcm_priv *priv = dev->ml_priv;
        struct mpc_group *grp = priv->mpcg;
        struct channel *wch = priv->channel[CTCM_WRITE];
        struct channel *rch = priv->channel[CTCM_READ];
        struct sk_buff *skb;
        struct th_sweep *header;
        int rc = 0;
        unsigned long saveflags = 0;

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

        if (grp->in_sweep == 0)
                                goto done;

        CTCM_PR_DBGDATA("%s: 1: ToVTAM_th_seq= %08x\n" ,
                                __func__, wch->th_seq_num);
        CTCM_PR_DBGDATA("%s: 1: FromVTAM_th_seq= %08x\n" ,
                                __func__, rch->th_seq_num);

        if (fsm_getstate(wch->fsm) != CTC_STATE_TXIDLE) {
                /* give the previous IO time to complete */
                fsm_addtimer(&wch->sweep_timer,
                        200, CTC_EVENT_RSWEEP_TIMER, wch);
                                goto done;
        }

        skb = skb_dequeue(&wch->sweep_queue);
        if (!skb)
                                goto done;

        if (set_normalized_cda(&wch->ccw[4], skb->data)) {
                grp->in_sweep = 0;
                ctcm_clear_busy_do(dev);
                dev_kfree_skb_any(skb);
                fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
                                goto done;
        } else {
                atomic_inc(&skb->users);
                skb_queue_tail(&wch->io_queue, skb);
        }

        /* send out the sweep */
        wch->ccw[4].count = skb->len;

        header = (struct th_sweep *)skb->data;
        switch (header->th.th_ch_flag) {
        case TH_SWEEP_REQ:
                grp->sweep_req_pend_num--;
                break;
        case TH_SWEEP_RESP:
                grp->sweep_rsp_pend_num--;
                break;
        }

        header->sw.th_last_seq = wch->th_seq_num;

        CTCM_CCW_DUMP((char *)&wch->ccw[3], sizeof(struct ccw1) * 3);
        CTCM_PR_DBGDATA("%s: sweep packet\n", __func__);
        CTCM_D3_DUMP((char *)header, TH_SWEEP_LENGTH);

        fsm_addtimer(&wch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, wch);
        fsm_newstate(wch->fsm, CTC_STATE_TX);

        spin_lock_irqsave(get_ccwdev_lock(wch->cdev), saveflags);
        wch->prof.send_stamp = current_kernel_time(); /* xtime */
        rc = ccw_device_start(wch->cdev, &wch->ccw[3],
                                        (unsigned long) wch, 0xff, 0);
        spin_unlock_irqrestore(get_ccwdev_lock(wch->cdev), saveflags);

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

        CTCM_PR_DBGDATA("%s: To-/From-VTAM_th_seq = %08x/%08x\n" ,
                        __func__, wch->th_seq_num, rch->th_seq_num);

        if (rc != 0)
                ctcm_ccw_check_rc(wch, rc, "send sweep");

done:
        return;
}


/*
 * The ctcmpc statemachine for a channel.
 */

const fsm_node ctcmpc_ch_fsm[] = {
        { CTC_STATE_STOPPED,    CTC_EVENT_STOP,         ctcm_action_nop  },
        { CTC_STATE_STOPPED,    CTC_EVENT_START,        ctcm_chx_start  },
        { CTC_STATE_STOPPED,    CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_STOPPED,    CTC_EVENT_FINSTAT,      ctcm_action_nop  },
        { CTC_STATE_STOPPED,    CTC_EVENT_MC_FAIL,      ctcm_action_nop  },

        { CTC_STATE_NOTOP,      CTC_EVENT_STOP,         ctcm_chx_stop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_FINSTAT,      ctcm_action_nop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_MC_FAIL,      ctcm_action_nop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_MC_GOOD,      ctcm_chx_start  },
        { CTC_STATE_NOTOP,      CTC_EVENT_UC_RCRESET,   ctcm_chx_stop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_UC_RSRESET,   ctcm_chx_stop  },
        { CTC_STATE_NOTOP,      CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },

        { CTC_STATE_STARTWAIT,  CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_FINSTAT,      ctcm_chx_setmode  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_TIMER,        ctcm_chx_setuperr  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_STARTWAIT,  CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_STARTRETRY, CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_STARTRETRY, CTC_EVENT_TIMER,        ctcm_chx_setmode  },
        { CTC_STATE_STARTRETRY, CTC_EVENT_FINSTAT,      ctcm_chx_setmode  },
        { CTC_STATE_STARTRETRY, CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_STARTRETRY, CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },

        { CTC_STATE_SETUPWAIT,  CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_FINSTAT,      ctcmpc_chx_firstio  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_UC_RCRESET,   ctcm_chx_setuperr  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_TIMER,        ctcm_chx_setmode  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_SETUPWAIT,  CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CTC_STATE_RXINIT,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_RXINIT,     CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_RXINIT,     CTC_EVENT_FINSTAT,      ctcmpc_chx_rxidle  },
        { CTC_STATE_RXINIT,     CTC_EVENT_UC_RCRESET,   ctcm_chx_rxiniterr  },
        { CTC_STATE_RXINIT,     CTC_EVENT_UC_RSRESET,   ctcm_chx_rxiniterr  },
        { CTC_STATE_RXINIT,     CTC_EVENT_TIMER,        ctcm_chx_rxiniterr  },
        { CTC_STATE_RXINIT,     CTC_EVENT_ATTNBUSY,     ctcm_chx_rxinitfail  },
        { CTC_STATE_RXINIT,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_RXINIT,     CTC_EVENT_UC_ZERO,      ctcmpc_chx_firstio  },
        { CTC_STATE_RXINIT,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },

        { CH_XID0_PENDING,      CTC_EVENT_FINSTAT,      ctcm_action_nop  },
        { CH_XID0_PENDING,      CTC_EVENT_ATTN,         ctcmpc_chx_attn  },
        { CH_XID0_PENDING,      CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CH_XID0_PENDING,      CTC_EVENT_START,        ctcm_action_nop  },
        { CH_XID0_PENDING,      CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CH_XID0_PENDING,      CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CH_XID0_PENDING,      CTC_EVENT_UC_RCRESET,   ctcm_chx_setuperr  },
        { CH_XID0_PENDING,      CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CH_XID0_PENDING,      CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CH_XID0_PENDING,      CTC_EVENT_ATTNBUSY,     ctcm_chx_iofatal  },

        { CH_XID0_INPROGRESS,   CTC_EVENT_FINSTAT,      ctcmpc_chx_rx  },
        { CH_XID0_INPROGRESS,   CTC_EVENT_ATTN,         ctcmpc_chx_attn  },
        { CH_XID0_INPROGRESS,   CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CH_XID0_INPROGRESS,   CTC_EVENT_START,        ctcm_action_nop  },
        { CH_XID0_INPROGRESS,   CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CH_XID0_INPROGRESS,   CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CH_XID0_INPROGRESS,   CTC_EVENT_UC_ZERO,      ctcmpc_chx_rx  },
        { CH_XID0_INPROGRESS,   CTC_EVENT_UC_RCRESET,   ctcm_chx_setuperr },
        { CH_XID0_INPROGRESS,   CTC_EVENT_ATTNBUSY,     ctcmpc_chx_attnbusy  },
        { CH_XID0_INPROGRESS,   CTC_EVENT_TIMER,        ctcmpc_chx_resend  },
        { CH_XID0_INPROGRESS,   CTC_EVENT_IO_EBUSY,     ctcm_chx_fail  },

        { CH_XID7_PENDING,      CTC_EVENT_FINSTAT,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING,      CTC_EVENT_ATTN,         ctcmpc_chx_attn  },
        { CH_XID7_PENDING,      CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CH_XID7_PENDING,      CTC_EVENT_START,        ctcm_action_nop  },
        { CH_XID7_PENDING,      CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CH_XID7_PENDING,      CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CH_XID7_PENDING,      CTC_EVENT_UC_ZERO,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING,      CTC_EVENT_UC_RCRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING,      CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING,      CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING,      CTC_EVENT_ATTNBUSY,     ctcm_chx_iofatal  },
        { CH_XID7_PENDING,      CTC_EVENT_TIMER,        ctcmpc_chx_resend  },
        { CH_XID7_PENDING,      CTC_EVENT_IO_EBUSY,     ctcm_chx_fail  },

        { CH_XID7_PENDING1,     CTC_EVENT_FINSTAT,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING1,     CTC_EVENT_ATTN,         ctcmpc_chx_attn  },
        { CH_XID7_PENDING1,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CH_XID7_PENDING1,     CTC_EVENT_START,        ctcm_action_nop  },
        { CH_XID7_PENDING1,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CH_XID7_PENDING1,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CH_XID7_PENDING1,     CTC_EVENT_UC_ZERO,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING1,     CTC_EVENT_UC_RCRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING1,     CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING1,     CTC_EVENT_ATTNBUSY,     ctcm_chx_iofatal  },
        { CH_XID7_PENDING1,     CTC_EVENT_TIMER,        ctcmpc_chx_resend  },
        { CH_XID7_PENDING1,     CTC_EVENT_IO_EBUSY,     ctcm_chx_fail  },

        { CH_XID7_PENDING2,     CTC_EVENT_FINSTAT,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING2,     CTC_EVENT_ATTN,         ctcmpc_chx_attn  },
        { CH_XID7_PENDING2,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CH_XID7_PENDING2,     CTC_EVENT_START,        ctcm_action_nop  },
        { CH_XID7_PENDING2,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CH_XID7_PENDING2,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CH_XID7_PENDING2,     CTC_EVENT_UC_ZERO,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING2,     CTC_EVENT_UC_RCRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING2,     CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING2,     CTC_EVENT_ATTNBUSY,     ctcm_chx_iofatal  },
        { CH_XID7_PENDING2,     CTC_EVENT_TIMER,        ctcmpc_chx_resend  },
        { CH_XID7_PENDING2,     CTC_EVENT_IO_EBUSY,     ctcm_chx_fail  },

        { CH_XID7_PENDING3,     CTC_EVENT_FINSTAT,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING3,     CTC_EVENT_ATTN,         ctcmpc_chx_attn  },
        { CH_XID7_PENDING3,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CH_XID7_PENDING3,     CTC_EVENT_START,        ctcm_action_nop  },
        { CH_XID7_PENDING3,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CH_XID7_PENDING3,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CH_XID7_PENDING3,     CTC_EVENT_UC_ZERO,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING3,     CTC_EVENT_UC_RCRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING3,     CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING3,     CTC_EVENT_ATTNBUSY,     ctcm_chx_iofatal  },
        { CH_XID7_PENDING3,     CTC_EVENT_TIMER,        ctcmpc_chx_resend  },
        { CH_XID7_PENDING3,     CTC_EVENT_IO_EBUSY,     ctcm_chx_fail  },

        { CH_XID7_PENDING4,     CTC_EVENT_FINSTAT,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING4,     CTC_EVENT_ATTN,         ctcmpc_chx_attn  },
        { CH_XID7_PENDING4,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CH_XID7_PENDING4,     CTC_EVENT_START,        ctcm_action_nop  },
        { CH_XID7_PENDING4,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CH_XID7_PENDING4,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CH_XID7_PENDING4,     CTC_EVENT_UC_ZERO,      ctcmpc_chx_rx  },
        { CH_XID7_PENDING4,     CTC_EVENT_UC_RCRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING4,     CTC_EVENT_UC_RSRESET,   ctcm_chx_setuperr  },
        { CH_XID7_PENDING4,     CTC_EVENT_ATTNBUSY,     ctcm_chx_iofatal  },
        { CH_XID7_PENDING4,     CTC_EVENT_TIMER,        ctcmpc_chx_resend  },
        { CH_XID7_PENDING4,     CTC_EVENT_IO_EBUSY,     ctcm_chx_fail  },

        { CTC_STATE_RXIDLE,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_FINSTAT,      ctcmpc_chx_rx  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_UC_RCRESET,   ctcm_chx_rxdisc  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_UC_RSRESET,   ctcm_chx_fail  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_RXIDLE,     CTC_EVENT_UC_ZERO,      ctcmpc_chx_rx  },

        { CTC_STATE_TXINIT,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TXINIT,     CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_TXINIT,     CTC_EVENT_FINSTAT,      ctcm_chx_txidle  },
        { CTC_STATE_TXINIT,     CTC_EVENT_UC_RCRESET,   ctcm_chx_txiniterr  },
        { CTC_STATE_TXINIT,     CTC_EVENT_UC_RSRESET,   ctcm_chx_txiniterr  },
        { CTC_STATE_TXINIT,     CTC_EVENT_TIMER,        ctcm_chx_txiniterr  },
        { CTC_STATE_TXINIT,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_TXINIT,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_TXINIT,     CTC_EVENT_RSWEEP_TIMER, ctcmpc_chx_send_sweep },

        { CTC_STATE_TXIDLE,     CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_FINSTAT,      ctcmpc_chx_firstio  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_UC_RCRESET,   ctcm_chx_fail  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_UC_RSRESET,   ctcm_chx_fail  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_TXIDLE,     CTC_EVENT_RSWEEP_TIMER, ctcmpc_chx_send_sweep },

        { CTC_STATE_TERM,       CTC_EVENT_STOP,         ctcm_action_nop  },
        { CTC_STATE_TERM,       CTC_EVENT_START,        ctcm_chx_restart  },
        { CTC_STATE_TERM,       CTC_EVENT_FINSTAT,      ctcm_chx_stopped  },
        { CTC_STATE_TERM,       CTC_EVENT_UC_RCRESET,   ctcm_action_nop  },
        { CTC_STATE_TERM,       CTC_EVENT_UC_RSRESET,   ctcm_action_nop  },
        { CTC_STATE_TERM,       CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_TERM,       CTC_EVENT_IO_EBUSY,     ctcm_chx_fail  },
        { CTC_STATE_TERM,       CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },

        { CTC_STATE_DTERM,      CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_DTERM,      CTC_EVENT_START,        ctcm_chx_restart  },
        { CTC_STATE_DTERM,      CTC_EVENT_FINSTAT,      ctcm_chx_setmode  },
        { CTC_STATE_DTERM,      CTC_EVENT_UC_RCRESET,   ctcm_action_nop  },
        { CTC_STATE_DTERM,      CTC_EVENT_UC_RSRESET,   ctcm_action_nop  },
        { CTC_STATE_DTERM,      CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_DTERM,      CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },

        { CTC_STATE_TX,         CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TX,         CTC_EVENT_START,        ctcm_action_nop  },
        { CTC_STATE_TX,         CTC_EVENT_FINSTAT,      ctcmpc_chx_txdone  },
        { CTC_STATE_TX,         CTC_EVENT_UC_RCRESET,   ctcm_chx_fail  },
        { CTC_STATE_TX,         CTC_EVENT_UC_RSRESET,   ctcm_chx_fail  },
        { CTC_STATE_TX,         CTC_EVENT_TIMER,        ctcm_chx_txretry  },
        { CTC_STATE_TX,         CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_TX,         CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_TX,         CTC_EVENT_RSWEEP_TIMER, ctcmpc_chx_send_sweep },
        { CTC_STATE_TX,         CTC_EVENT_IO_EBUSY,     ctcm_chx_fail  },

        { CTC_STATE_RXERR,      CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TXERR,      CTC_EVENT_STOP,         ctcm_chx_haltio  },
        { CTC_STATE_TXERR,      CTC_EVENT_IO_ENODEV,    ctcm_chx_iofatal  },
        { CTC_STATE_TXERR,      CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
        { CTC_STATE_RXERR,      CTC_EVENT_MC_FAIL,      ctcm_chx_fail  },
};

int mpc_ch_fsm_len = ARRAY_SIZE(ctcmpc_ch_fsm);

/*
 * Actions for interface - statemachine.
 */

/**
 * Startup channels by sending CTC_EVENT_START to each channel.
 *
 * fi           An instance of an interface statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from struct net_device * upon call.
 */
static void dev_action_start(fsm_instance *fi, int event, void *arg)
{
        struct net_device *dev = arg;
        struct ctcm_priv *priv = dev->ml_priv;
        int direction;

        CTCMY_DBF_DEV_NAME(SETUP, dev, "");

        fsm_deltimer(&priv->restart_timer);
        fsm_newstate(fi, DEV_STATE_STARTWAIT_RXTX);
        if (IS_MPC(priv))
                priv->mpcg->channels_terminating = 0;
        for (direction = CTCM_READ; direction <= CTCM_WRITE; direction++) {
                struct channel *ch = priv->channel[direction];
                fsm_event(ch->fsm, CTC_EVENT_START, ch);
        }
}

/**
 * Shutdown channels by sending CTC_EVENT_STOP to each channel.
 *
 * fi           An instance of an interface statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from struct net_device * upon call.
 */
static void dev_action_stop(fsm_instance *fi, int event, void *arg)
{
        int direction;
        struct net_device *dev = arg;
        struct ctcm_priv *priv = dev->ml_priv;

        CTCMY_DBF_DEV_NAME(SETUP, dev, "");

        fsm_newstate(fi, DEV_STATE_STOPWAIT_RXTX);
        for (direction = CTCM_READ; direction <= CTCM_WRITE; direction++) {
                struct channel *ch = priv->channel[direction];
                fsm_event(ch->fsm, CTC_EVENT_STOP, ch);
                ch->th_seq_num = 0x00;
                CTCM_PR_DEBUG("%s: CH_th_seq= %08x\n",
                                __func__, ch->th_seq_num);
        }
        if (IS_MPC(priv))
                fsm_newstate(priv->mpcg->fsm, MPCG_STATE_RESET);
}

static void dev_action_restart(fsm_instance *fi, int event, void *arg)
{
        int restart_timer;
        struct net_device *dev = arg;
        struct ctcm_priv *priv = dev->ml_priv;

        CTCMY_DBF_DEV_NAME(TRACE, dev, "");

        if (IS_MPC(priv)) {
                restart_timer = CTCM_TIME_1_SEC;
        } else {
                restart_timer = CTCM_TIME_5_SEC;
        }
        dev_info(&dev->dev, "Restarting device\n");

        dev_action_stop(fi, event, arg);
        fsm_event(priv->fsm, DEV_EVENT_STOP, dev);
        if (IS_MPC(priv))
                fsm_newstate(priv->mpcg->fsm, MPCG_STATE_RESET);

        /* going back into start sequence too quickly can         */
        /* result in the other side becoming unreachable   due    */
        /* to sense reported when IO is aborted                   */
        fsm_addtimer(&priv->restart_timer, restart_timer,
                        DEV_EVENT_START, dev);
}

/**
 * Called from channel statemachine
 * when a channel is up and running.
 *
 * fi           An instance of an interface statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from struct net_device * upon call.
 */
static void dev_action_chup(fsm_instance *fi, int event, void *arg)
{
        struct net_device *dev = arg;
        struct ctcm_priv *priv = dev->ml_priv;
        int dev_stat = fsm_getstate(fi);

        CTCM_DBF_TEXT_(SETUP, CTC_DBF_NOTICE,
                        "%s(%s): priv = %p [%d,%d]\n ", CTCM_FUNTAIL,
                                dev->name, dev->ml_priv, dev_stat, event);

        switch (fsm_getstate(fi)) {
        case DEV_STATE_STARTWAIT_RXTX:
                if (event == DEV_EVENT_RXUP)
                        fsm_newstate(fi, DEV_STATE_STARTWAIT_TX);
                else
                        fsm_newstate(fi, DEV_STATE_STARTWAIT_RX);
                break;
        case DEV_STATE_STARTWAIT_RX:
                if (event == DEV_EVENT_RXUP) {
                        fsm_newstate(fi, DEV_STATE_RUNNING);
                        dev_info(&dev->dev,
                                "Connected with remote side\n");
                        ctcm_clear_busy(dev);
                }
                break;
        case DEV_STATE_STARTWAIT_TX:
                if (event == DEV_EVENT_TXUP) {
                        fsm_newstate(fi, DEV_STATE_RUNNING);
                        dev_info(&dev->dev,
                                "Connected with remote side\n");
                        ctcm_clear_busy(dev);
                }
                break;
        case DEV_STATE_STOPWAIT_TX:
                if (event == DEV_EVENT_RXUP)
                        fsm_newstate(fi, DEV_STATE_STOPWAIT_RXTX);
                break;
        case DEV_STATE_STOPWAIT_RX:
                if (event == DEV_EVENT_TXUP)
                        fsm_newstate(fi, DEV_STATE_STOPWAIT_RXTX);
                break;
        }

        if (IS_MPC(priv)) {
                if (event == DEV_EVENT_RXUP)
                        mpc_channel_action(priv->channel[CTCM_READ],
                                CTCM_READ, MPC_CHANNEL_ADD);
                else
                        mpc_channel_action(priv->channel[CTCM_WRITE],
                                CTCM_WRITE, MPC_CHANNEL_ADD);
        }
}

/**
 * Called from device statemachine
 * when a channel has been shutdown.
 *
 * fi           An instance of an interface statemachine.
 * event        The event, just happened.
 * arg          Generic pointer, casted from struct net_device * upon call.
 */
static void dev_action_chdown(fsm_instance *fi, int event, void *arg)
{

        struct net_device *dev = arg;
        struct ctcm_priv *priv = dev->ml_priv;

        CTCMY_DBF_DEV_NAME(SETUP, dev, "");

        switch (fsm_getstate(fi)) {
        case DEV_STATE_RUNNING:
                if (event == DEV_EVENT_TXDOWN)
                        fsm_newstate(fi, DEV_STATE_STARTWAIT_TX);
                else
                        fsm_newstate(fi, DEV_STATE_STARTWAIT_RX);
                break;
        case DEV_STATE_STARTWAIT_RX:
                if (event == DEV_EVENT_TXDOWN)
                        fsm_newstate(fi, DEV_STATE_STARTWAIT_RXTX);
                break;
        case DEV_STATE_STARTWAIT_TX:
                if (event == DEV_EVENT_RXDOWN)
                        fsm_newstate(fi, DEV_STATE_STARTWAIT_RXTX);
                break;
        case DEV_STATE_STOPWAIT_RXTX:
                if (event == DEV_EVENT_TXDOWN)
                        fsm_newstate(fi, DEV_STATE_STOPWAIT_RX);
                else
                        fsm_newstate(fi, DEV_STATE_STOPWAIT_TX);
                break;
        case DEV_STATE_STOPWAIT_RX:
                if (event == DEV_EVENT_RXDOWN)
                        fsm_newstate(fi, DEV_STATE_STOPPED);
                break;
        case DEV_STATE_STOPWAIT_TX:
                if (event == DEV_EVENT_TXDOWN)
                        fsm_newstate(fi, DEV_STATE_STOPPED);
                break;
        }
        if (IS_MPC(priv)) {
                if (event == DEV_EVENT_RXDOWN)
                        mpc_channel_action(priv->channel[CTCM_READ],
                                CTCM_READ, MPC_CHANNEL_REMOVE);
                else
                        mpc_channel_action(priv->channel[CTCM_WRITE],
                                CTCM_WRITE, MPC_CHANNEL_REMOVE);
        }
}

const fsm_node dev_fsm[] = {
        { DEV_STATE_STOPPED,        DEV_EVENT_START,   dev_action_start   },
        { DEV_STATE_STOPWAIT_RXTX,  DEV_EVENT_START,   dev_action_start   },
        { DEV_STATE_STOPWAIT_RXTX,  DEV_EVENT_RXDOWN,  dev_action_chdown  },
        { DEV_STATE_STOPWAIT_RXTX,  DEV_EVENT_TXDOWN,  dev_action_chdown  },
        { DEV_STATE_STOPWAIT_RXTX,  DEV_EVENT_RESTART, dev_action_restart },
        { DEV_STATE_STOPWAIT_RX,    DEV_EVENT_START,   dev_action_start   },
        { DEV_STATE_STOPWAIT_RX,    DEV_EVENT_RXUP,    dev_action_chup    },
        { DEV_STATE_STOPWAIT_RX,    DEV_EVENT_TXUP,    dev_action_chup    },
        { DEV_STATE_STOPWAIT_RX,    DEV_EVENT_RXDOWN,  dev_action_chdown  },
        { DEV_STATE_STOPWAIT_RX,    DEV_EVENT_RESTART, dev_action_restart },
        { DEV_STATE_STOPWAIT_TX,    DEV_EVENT_START,   dev_action_start   },
        { DEV_STATE_STOPWAIT_TX,    DEV_EVENT_RXUP,    dev_action_chup    },
        { DEV_STATE_STOPWAIT_TX,    DEV_EVENT_TXUP,    dev_action_chup    },
        { DEV_STATE_STOPWAIT_TX,    DEV_EVENT_TXDOWN,  dev_action_chdown  },
        { DEV_STATE_STOPWAIT_TX,    DEV_EVENT_RESTART, dev_action_restart },
        { DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_STOP,    dev_action_stop    },
        { DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_RXUP,    dev_action_chup    },
        { DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_TXUP,    dev_action_chup    },
        { DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_RXDOWN,  dev_action_chdown  },
        { DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_TXDOWN,  dev_action_chdown  },
        { DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_RESTART, dev_action_restart },
        { DEV_STATE_STARTWAIT_TX,   DEV_EVENT_STOP,    dev_action_stop    },
        { DEV_STATE_STARTWAIT_TX,   DEV_EVENT_RXUP,    dev_action_chup    },
        { DEV_STATE_STARTWAIT_TX,   DEV_EVENT_TXUP,    dev_action_chup    },
        { DEV_STATE_STARTWAIT_TX,   DEV_EVENT_RXDOWN,  dev_action_chdown  },
        { DEV_STATE_STARTWAIT_TX,   DEV_EVENT_RESTART, dev_action_restart },
        { DEV_STATE_STARTWAIT_RX,   DEV_EVENT_STOP,    dev_action_stop    },
        { DEV_STATE_STARTWAIT_RX,   DEV_EVENT_RXUP,    dev_action_chup    },
        { DEV_STATE_STARTWAIT_RX,   DEV_EVENT_TXUP,    dev_action_chup    },
        { DEV_STATE_STARTWAIT_RX,   DEV_EVENT_TXDOWN,  dev_action_chdown  },
        { DEV_STATE_STARTWAIT_RX,   DEV_EVENT_RESTART, dev_action_restart },
        { DEV_STATE_RUNNING,        DEV_EVENT_STOP,    dev_action_stop    },
        { DEV_STATE_RUNNING,        DEV_EVENT_RXDOWN,  dev_action_chdown  },
        { DEV_STATE_RUNNING,        DEV_EVENT_TXDOWN,  dev_action_chdown  },
        { DEV_STATE_RUNNING,        DEV_EVENT_TXUP,    ctcm_action_nop    },
        { DEV_STATE_RUNNING,        DEV_EVENT_RXUP,    ctcm_action_nop    },
        { DEV_STATE_RUNNING,        DEV_EVENT_RESTART, dev_action_restart },
};

int dev_fsm_len = ARRAY_SIZE(dev_fsm);

/* --- This is the END my friend --- */