Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1821 insertions, 0 deletions

diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c
new file mode 100644
index 000000000..fb0e8f1ca
--- /dev/null
+++ b/drivers/s390/net/ctcm_main.c
@@ -0,0 +1,1821 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2001, 2009
+ * Author(s):
+ *	Original CTC driver(s):
+ *		Fritz Elfert (felfert@millenux.com)
+ *		Dieter Wellerdiek (wel@de.ibm.com)
+ *		Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *		Denis Joseph Barrow (barrow_dj@yahoo.com)
+ *		Jochen Roehrig (roehrig@de.ibm.com)
+ *		Cornelia Huck <cornelia.huck@de.ibm.com>
+ *	MPC additions:
+ *		Belinda Thompson (belindat@us.ibm.com)
+ *		Andy Richter (richtera@us.ibm.com)
+ *	Revived by:
+ *		Peter Tiedemann (ptiedem@de.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 "ctcm_fsms.h"
+#include "ctcm_main.h"
+
+/* Some common global variables */
+
+/**
+ * The root device for ctcm group devices
+ */
+static struct device *ctcm_root_dev;
+
+/*
+ * Linked list of all detected channels.
+ */
+struct channel *channels;
+
+/**
+ * Unpack a just received skb and hand it over to
+ * upper layers.
+ *
+ *  ch		The channel where this skb has been received.
+ *  pskb	The received skb.
+ */
+void ctcm_unpack_skb(struct channel *ch, struct sk_buff *pskb)
+{
+	struct net_device *dev = ch->netdev;
+	struct ctcm_priv *priv = dev->ml_priv;
+	__u16 len = *((__u16 *) pskb->data);
+
+	skb_put(pskb, 2 + LL_HEADER_LENGTH);
+	skb_pull(pskb, 2);
+	pskb->dev = dev;
+	pskb->ip_summed = CHECKSUM_UNNECESSARY;
+	while (len > 0) {
+		struct sk_buff *skb;
+		int skblen;
+		struct ll_header *header = (struct ll_header *)pskb->data;
+
+		skb_pull(pskb, LL_HEADER_LENGTH);
+		if ((ch->protocol == CTCM_PROTO_S390) &&
+		    (header->type != ETH_P_IP)) {
+			if (!(ch->logflags & LOG_FLAG_ILLEGALPKT)) {
+				ch->logflags |= LOG_FLAG_ILLEGALPKT;
+				/*
+				 * Check packet type only if we stick strictly
+				 * to S/390's protocol of OS390. This only
+				 * supports IP. Otherwise allow any packet
+				 * type.
+				 */
+				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+					"%s(%s): Illegal packet type 0x%04x"
+					" - dropping",
+					CTCM_FUNTAIL, dev->name, header->type);
+			}
+			priv->stats.rx_dropped++;
+			priv->stats.rx_frame_errors++;
+			return;
+		}
+		pskb->protocol = cpu_to_be16(header->type);
+		if ((header->length <= LL_HEADER_LENGTH) ||
+		    (len <= LL_HEADER_LENGTH)) {
+			if (!(ch->logflags & LOG_FLAG_ILLEGALSIZE)) {
+				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+					"%s(%s): Illegal packet size %d(%d,%d)"
+					"- dropping",
+					CTCM_FUNTAIL, dev->name,
+					header->length, dev->mtu, len);
+				ch->logflags |= LOG_FLAG_ILLEGALSIZE;
+			}
+
+			priv->stats.rx_dropped++;
+			priv->stats.rx_length_errors++;
+			return;
+		}
+		header->length -= LL_HEADER_LENGTH;
+		len -= LL_HEADER_LENGTH;
+		if ((header->length > skb_tailroom(pskb)) ||
+		    (header->length > len)) {
+			if (!(ch->logflags & LOG_FLAG_OVERRUN)) {
+				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+					"%s(%s): Packet size %d (overrun)"
+					" - dropping", CTCM_FUNTAIL,
+						dev->name, header->length);
+				ch->logflags |= LOG_FLAG_OVERRUN;
+			}
+
+			priv->stats.rx_dropped++;
+			priv->stats.rx_length_errors++;
+			return;
+		}
+		skb_put(pskb, header->length);
+		skb_reset_mac_header(pskb);
+		len -= header->length;
+		skb = dev_alloc_skb(pskb->len);
+		if (!skb) {
+			if (!(ch->logflags & LOG_FLAG_NOMEM)) {
+				CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+					"%s(%s): MEMORY allocation error",
+						CTCM_FUNTAIL, dev->name);
+				ch->logflags |= LOG_FLAG_NOMEM;
+			}
+			priv->stats.rx_dropped++;
+			return;
+		}
+		skb_copy_from_linear_data(pskb, skb_put(skb, pskb->len),
+					  pskb->len);
+		skb_reset_mac_header(skb);
+		skb->dev = pskb->dev;
+		skb->protocol = pskb->protocol;
+		pskb->ip_summed = CHECKSUM_UNNECESSARY;
+		skblen = skb->len;
+		/*
+		 * reset logflags
+		 */
+		ch->logflags = 0;
+		priv->stats.rx_packets++;
+		priv->stats.rx_bytes += skblen;
+		netif_rx_ni(skb);
+		if (len > 0) {
+			skb_pull(pskb, header->length);
+			if (skb_tailroom(pskb) < LL_HEADER_LENGTH) {
+				CTCM_DBF_DEV_NAME(TRACE, dev,
+					"Overrun in ctcm_unpack_skb");
+				ch->logflags |= LOG_FLAG_OVERRUN;
+				return;
+			}
+			skb_put(pskb, LL_HEADER_LENGTH);
+		}
+	}
+}
+
+/**
+ * Release a specific channel in the channel list.
+ *
+ *  ch		Pointer to channel struct to be released.
+ */
+static void channel_free(struct channel *ch)
+{
+	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO, "%s(%s)", CTCM_FUNTAIL, ch->id);
+	ch->flags &= ~CHANNEL_FLAGS_INUSE;
+	fsm_newstate(ch->fsm, CTC_STATE_IDLE);
+}
+
+/**
+ * Remove a specific channel in the channel list.
+ *
+ *  ch		Pointer to channel struct to be released.
+ */
+static void channel_remove(struct channel *ch)
+{
+	struct channel **c = &channels;
+	char chid[CTCM_ID_SIZE+1];
+	int ok = 0;
+
+	if (ch == NULL)
+		return;
+	else
+		strncpy(chid, ch->id, CTCM_ID_SIZE);
+
+	channel_free(ch);
+	while (*c) {
+		if (*c == ch) {
+			*c = ch->next;
+			fsm_deltimer(&ch->timer);
+			if (IS_MPC(ch))
+				fsm_deltimer(&ch->sweep_timer);
+
+			kfree_fsm(ch->fsm);
+			clear_normalized_cda(&ch->ccw[4]);
+			if (ch->trans_skb != NULL) {
+				clear_normalized_cda(&ch->ccw[1]);
+				dev_kfree_skb_any(ch->trans_skb);
+			}
+			if (IS_MPC(ch)) {
+				tasklet_kill(&ch->ch_tasklet);
+				tasklet_kill(&ch->ch_disc_tasklet);
+				kfree(ch->discontact_th);
+			}
+			kfree(ch->ccw);
+			kfree(ch->irb);
+			kfree(ch);
+			ok = 1;
+			break;
+		}
+		c = &((*c)->next);
+	}
+
+	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO, "%s(%s) %s", CTCM_FUNTAIL,
+			chid, ok ? "OK" : "failed");
+}
+
+/**
+ * Get a specific channel from the channel list.
+ *
+ *  type	Type of channel we are interested in.
+ *  id		Id of channel we are interested in.
+ *  direction	Direction we want to use this channel for.
+ *
+ * returns Pointer to a channel or NULL if no matching channel available.
+ */
+static struct channel *channel_get(enum ctcm_channel_types type,
+					char *id, int direction)
+{
+	struct channel *ch = channels;
+
+	while (ch && (strncmp(ch->id, id, CTCM_ID_SIZE) || (ch->type != type)))
+		ch = ch->next;
+	if (!ch) {
+		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+				"%s(%d, %s, %d) not found in channel list\n",
+				CTCM_FUNTAIL, type, id, direction);
+	} else {
+		if (ch->flags & CHANNEL_FLAGS_INUSE)
+			ch = NULL;
+		else {
+			ch->flags |= CHANNEL_FLAGS_INUSE;
+			ch->flags &= ~CHANNEL_FLAGS_RWMASK;
+			ch->flags |= (direction == CTCM_WRITE)
+			    ? CHANNEL_FLAGS_WRITE : CHANNEL_FLAGS_READ;
+			fsm_newstate(ch->fsm, CTC_STATE_STOPPED);
+		}
+	}
+	return ch;
+}
+
+static long ctcm_check_irb_error(struct ccw_device *cdev, struct irb *irb)
+{
+	if (!IS_ERR(irb))
+		return 0;
+
+	CTCM_DBF_TEXT_(ERROR, CTC_DBF_WARN,
+			"irb error %ld on device %s\n",
+				PTR_ERR(irb), dev_name(&cdev->dev));
+
+	switch (PTR_ERR(irb)) {
+	case -EIO:
+		dev_err(&cdev->dev,
+			"An I/O-error occurred on the CTCM device\n");
+		break;
+	case -ETIMEDOUT:
+		dev_err(&cdev->dev,
+			"An adapter hardware operation timed out\n");
+		break;
+	default:
+		dev_err(&cdev->dev,
+			"An error occurred on the adapter hardware\n");
+	}
+	return PTR_ERR(irb);
+}
+
+
+/**
+ * Check sense of a unit check.
+ *
+ *  ch		The channel, the sense code belongs to.
+ *  sense	The sense code to inspect.
+ */
+static void ccw_unit_check(struct channel *ch, __u8 sense)
+{
+	CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
+			"%s(%s): %02x",
+				CTCM_FUNTAIL, ch->id, sense);
+
+	if (sense & SNS0_INTERVENTION_REQ) {
+		if (sense & 0x01) {
+			if (ch->sense_rc != 0x01) {
+				pr_notice(
+					"%s: The communication peer has "
+					"disconnected\n", ch->id);
+				ch->sense_rc = 0x01;
+			}
+			fsm_event(ch->fsm, CTC_EVENT_UC_RCRESET, ch);
+		} else {
+			if (ch->sense_rc != SNS0_INTERVENTION_REQ) {
+				pr_notice(
+					"%s: The remote operating system is "
+					"not available\n", ch->id);
+				ch->sense_rc = SNS0_INTERVENTION_REQ;
+			}
+			fsm_event(ch->fsm, CTC_EVENT_UC_RSRESET, ch);
+		}
+	} else if (sense & SNS0_EQUIPMENT_CHECK) {
+		if (sense & SNS0_BUS_OUT_CHECK) {
+			if (ch->sense_rc != SNS0_BUS_OUT_CHECK) {
+				CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
+					"%s(%s): remote HW error %02x",
+						CTCM_FUNTAIL, ch->id, sense);
+				ch->sense_rc = SNS0_BUS_OUT_CHECK;
+			}
+			fsm_event(ch->fsm, CTC_EVENT_UC_HWFAIL, ch);
+		} else {
+			if (ch->sense_rc != SNS0_EQUIPMENT_CHECK) {
+				CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
+					"%s(%s): remote read parity error %02x",
+						CTCM_FUNTAIL, ch->id, sense);
+				ch->sense_rc = SNS0_EQUIPMENT_CHECK;
+			}
+			fsm_event(ch->fsm, CTC_EVENT_UC_RXPARITY, ch);
+		}
+	} else if (sense & SNS0_BUS_OUT_CHECK) {
+		if (ch->sense_rc != SNS0_BUS_OUT_CHECK) {
+			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
+				"%s(%s): BUS OUT error %02x",
+					CTCM_FUNTAIL, ch->id, sense);
+			ch->sense_rc = SNS0_BUS_OUT_CHECK;
+		}
+		if (sense & 0x04)	/* data-streaming timeout */
+			fsm_event(ch->fsm, CTC_EVENT_UC_TXTIMEOUT, ch);
+		else			/* Data-transfer parity error */
+			fsm_event(ch->fsm, CTC_EVENT_UC_TXPARITY, ch);
+	} else if (sense & SNS0_CMD_REJECT) {
+		if (ch->sense_rc != SNS0_CMD_REJECT) {
+			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
+				"%s(%s): Command rejected",
+						CTCM_FUNTAIL, ch->id);
+			ch->sense_rc = SNS0_CMD_REJECT;
+		}
+	} else if (sense == 0) {
+		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
+			"%s(%s): Unit check ZERO",
+					CTCM_FUNTAIL, ch->id);
+		fsm_event(ch->fsm, CTC_EVENT_UC_ZERO, ch);
+	} else {
+		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
+			"%s(%s): Unit check code %02x unknown",
+					CTCM_FUNTAIL, ch->id, sense);
+		fsm_event(ch->fsm, CTC_EVENT_UC_UNKNOWN, ch);
+	}
+}
+
+int ctcm_ch_alloc_buffer(struct channel *ch)
+{
+	clear_normalized_cda(&ch->ccw[1]);
+	ch->trans_skb = __dev_alloc_skb(ch->max_bufsize, GFP_ATOMIC | GFP_DMA);
+	if (ch->trans_skb == NULL) {
+		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+			"%s(%s): %s trans_skb allocation error",
+			CTCM_FUNTAIL, ch->id,
+			(CHANNEL_DIRECTION(ch->flags) == CTCM_READ) ?
+				"RX" : "TX");
+		return -ENOMEM;
+	}
+
+	ch->ccw[1].count = ch->max_bufsize;
+	if (set_normalized_cda(&ch->ccw[1], ch->trans_skb->data)) {
+		dev_kfree_skb(ch->trans_skb);
+		ch->trans_skb = NULL;
+		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+			"%s(%s): %s set norm_cda failed",
+			CTCM_FUNTAIL, ch->id,
+			(CHANNEL_DIRECTION(ch->flags) == CTCM_READ) ?
+				"RX" : "TX");
+		return -ENOMEM;
+	}
+
+	ch->ccw[1].count = 0;
+	ch->trans_skb_data = ch->trans_skb->data;
+	ch->flags &= ~CHANNEL_FLAGS_BUFSIZE_CHANGED;
+	return 0;
+}
+
+/*
+ * Interface API for upper network layers
+ */
+
+/**
+ * Open an interface.
+ * Called from generic network layer when ifconfig up is run.
+ *
+ *  dev		Pointer to interface struct.
+ *
+ * returns 0 on success, -ERRNO on failure. (Never fails.)
+ */
+int ctcm_open(struct net_device *dev)
+{
+	struct ctcm_priv *priv = dev->ml_priv;
+
+	CTCMY_DBF_DEV_NAME(SETUP, dev, "");
+	if (!IS_MPC(priv))
+		fsm_event(priv->fsm,	DEV_EVENT_START, dev);
+	return 0;
+}
+
+/**
+ * Close an interface.
+ * Called from generic network layer when ifconfig down is run.
+ *
+ *  dev		Pointer to interface struct.
+ *
+ * returns 0 on success, -ERRNO on failure. (Never fails.)
+ */
+int ctcm_close(struct net_device *dev)
+{
+	struct ctcm_priv *priv = dev->ml_priv;
+
+	CTCMY_DBF_DEV_NAME(SETUP, dev, "");
+	if (!IS_MPC(priv))
+		fsm_event(priv->fsm, DEV_EVENT_STOP, dev);
+	return 0;
+}
+
+
+/**
+ * Transmit a packet.
+ * This is a helper function for ctcm_tx().
+ *
+ *  ch		Channel to be used for sending.
+ *  skb		Pointer to struct sk_buff of packet to send.
+ *            The linklevel header has already been set up
+ *            by ctcm_tx().
+ *
+ * returns 0 on success, -ERRNO on failure. (Never fails.)
+ */
+static int ctcm_transmit_skb(struct channel *ch, struct sk_buff *skb)
+{
+	unsigned long saveflags;
+	struct ll_header header;
+	int rc = 0;
+	__u16 block_len;
+	int ccw_idx;
+	struct sk_buff *nskb;
+	unsigned long hi;
+
+	/* we need to acquire the lock for testing the state
+	 * otherwise we can have an IRQ changing the state to
+	 * TXIDLE after the test but before acquiring the lock.
+	 */
+	spin_lock_irqsave(&ch->collect_lock, saveflags);
+	if (fsm_getstate(ch->fsm) != CTC_STATE_TXIDLE) {
+		int l = skb->len + LL_HEADER_LENGTH;
+
+		if (ch->collect_len + l > ch->max_bufsize - 2) {
+			spin_unlock_irqrestore(&ch->collect_lock, saveflags);
+			return -EBUSY;
+		} else {
+			refcount_inc(&skb->users);
+			header.length = l;
+			header.type = be16_to_cpu(skb->protocol);
+			header.unused = 0;
+			memcpy(skb_push(skb, LL_HEADER_LENGTH), &header,
+			       LL_HEADER_LENGTH);
+			skb_queue_tail(&ch->collect_queue, skb);
+			ch->collect_len += l;
+		}
+		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
+				goto done;
+	}
+	spin_unlock_irqrestore(&ch->collect_lock, saveflags);
+	/*
+	 * Protect skb against beeing free'd by upper
+	 * layers.
+	 */
+	refcount_inc(&skb->users);
+	ch->prof.txlen += skb->len;
+	header.length = skb->len + LL_HEADER_LENGTH;
+	header.type = be16_to_cpu(skb->protocol);
+	header.unused = 0;
+	memcpy(skb_push(skb, LL_HEADER_LENGTH), &header, LL_HEADER_LENGTH);
+	block_len = skb->len + 2;
+	*((__u16 *)skb_push(skb, 2)) = block_len;
+
+	/*
+	 * IDAL support in CTCM is broken, so we have to
+	 * care about skb's above 2G ourselves.
+	 */
+	hi = ((unsigned long)skb_tail_pointer(skb) + LL_HEADER_LENGTH) >> 31;
+	if (hi) {
+		nskb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
+		if (!nskb) {
+			refcount_dec(&skb->users);
+			skb_pull(skb, LL_HEADER_LENGTH + 2);
+			ctcm_clear_busy(ch->netdev);
+			return -ENOMEM;
+		} else {
+			skb_put_data(nskb, skb->data, skb->len);
+			refcount_inc(&nskb->users);
+			refcount_dec(&skb->users);
+			dev_kfree_skb_irq(skb);
+			skb = nskb;
+		}
+	}
+
+	ch->ccw[4].count = block_len;
+	if (set_normalized_cda(&ch->ccw[4], skb->data)) {
+		/*
+		 * idal allocation failed, try via copying to
+		 * trans_skb. trans_skb usually has a pre-allocated
+		 * idal.
+		 */
+		if (ctcm_checkalloc_buffer(ch)) {
+			/*
+			 * Remove our header. It gets added
+			 * again on retransmit.
+			 */
+			refcount_dec(&skb->users);
+			skb_pull(skb, LL_HEADER_LENGTH + 2);
+			ctcm_clear_busy(ch->netdev);
+			return -ENOMEM;
+		}
+
+		skb_reset_tail_pointer(ch->trans_skb);
+		ch->trans_skb->len = 0;
+		ch->ccw[1].count = skb->len;
+		skb_copy_from_linear_data(skb,
+				skb_put(ch->trans_skb, skb->len), skb->len);
+		refcount_dec(&skb->users);
+		dev_kfree_skb_irq(skb);
+		ccw_idx = 0;
+	} else {
+		skb_queue_tail(&ch->io_queue, skb);
+		ccw_idx = 3;
+	}
+	if (do_debug_ccw)
+		ctcmpc_dumpit((char *)&ch->ccw[ccw_idx],
+					sizeof(struct ccw1) * 3);
+	ch->retry = 0;
+	fsm_newstate(ch->fsm, CTC_STATE_TX);
+	fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
+	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
+	ch->prof.send_stamp = jiffies;
+	rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx], 0, 0xff, 0);
+	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
+	if (ccw_idx == 3)
+		ch->prof.doios_single++;
+	if (rc != 0) {
+		fsm_deltimer(&ch->timer);
+		ctcm_ccw_check_rc(ch, rc, "single skb TX");
+		if (ccw_idx == 3)
+			skb_dequeue_tail(&ch->io_queue);
+		/*
+		 * Remove our header. It gets added
+		 * again on retransmit.
+		 */
+		skb_pull(skb, LL_HEADER_LENGTH + 2);
+	} else if (ccw_idx == 0) {
+		struct net_device *dev = ch->netdev;
+		struct ctcm_priv *priv = dev->ml_priv;
+		priv->stats.tx_packets++;
+		priv->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
+	}
+done:
+	ctcm_clear_busy(ch->netdev);
+	return rc;
+}
+
+static void ctcmpc_send_sweep_req(struct channel *rch)
+{
+	struct net_device *dev = rch->netdev;
+	struct ctcm_priv *priv;
+	struct mpc_group *grp;
+	struct th_sweep *header;
+	struct sk_buff *sweep_skb;
+	struct channel *ch;
+	/* int rc = 0; */
+
+	priv = dev->ml_priv;
+	grp = priv->mpcg;
+	ch = priv->channel[CTCM_WRITE];
+
+	/* sweep processing is not complete until response and request */
+	/* has completed for all read channels in group		       */
+	if (grp->in_sweep == 0) {
+		grp->in_sweep = 1;
+		grp->sweep_rsp_pend_num = grp->active_channels[CTCM_READ];
+		grp->sweep_req_pend_num = grp->active_channels[CTCM_READ];
+	}
+
+	sweep_skb = __dev_alloc_skb(MPC_BUFSIZE_DEFAULT, GFP_ATOMIC|GFP_DMA);
+
+	if (sweep_skb == NULL)	{
+		/* rc = -ENOMEM; */
+				goto nomem;
+	}
+
+	header = kmalloc(TH_SWEEP_LENGTH, gfp_type());
+
+	if (!header) {
+		dev_kfree_skb_any(sweep_skb);
+		/* rc = -ENOMEM; */
+				goto nomem;
+	}
+
+	header->th.th_seg	= 0x00 ;
+	header->th.th_ch_flag	= TH_SWEEP_REQ;  /* 0x0f */
+	header->th.th_blk_flag	= 0x00;
+	header->th.th_is_xid	= 0x00;
+	header->th.th_seq_num	= 0x00;
+	header->sw.th_last_seq	= ch->th_seq_num;
+
+	skb_put_data(sweep_skb, header, TH_SWEEP_LENGTH);
+
+	kfree(header);
+
+	netif_trans_update(dev);
+	skb_queue_tail(&ch->sweep_queue, sweep_skb);
+
+	fsm_addtimer(&ch->sweep_timer, 100, CTC_EVENT_RSWEEP_TIMER, ch);
+
+	return;
+
+nomem:
+	grp->in_sweep = 0;
+	ctcm_clear_busy(dev);
+	fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
+
+	return;
+}
+
+/*
+ * MPC mode version of transmit_skb
+ */
+static int ctcmpc_transmit_skb(struct channel *ch, struct sk_buff *skb)
+{
+	struct pdu *p_header;
+	struct net_device *dev = ch->netdev;
+	struct ctcm_priv *priv = dev->ml_priv;
+	struct mpc_group *grp = priv->mpcg;
+	struct th_header *header;
+	struct sk_buff *nskb;
+	int rc = 0;
+	int ccw_idx;
+	unsigned long hi;
+	unsigned long saveflags = 0;	/* avoids compiler warning */
+
+	CTCM_PR_DEBUG("Enter %s: %s, cp=%i ch=0x%p id=%s state=%s\n",
+			__func__, dev->name, smp_processor_id(), ch,
+					ch->id, fsm_getstate_str(ch->fsm));
+
+	if ((fsm_getstate(ch->fsm) != CTC_STATE_TXIDLE) || grp->in_sweep) {
+		spin_lock_irqsave(&ch->collect_lock, saveflags);
+		refcount_inc(&skb->users);
+		p_header = kmalloc(PDU_HEADER_LENGTH, gfp_type());
+
+		if (!p_header) {
+			spin_unlock_irqrestore(&ch->collect_lock, saveflags);
+				goto nomem_exit;
+		}
+
+		p_header->pdu_offset = skb->len;
+		p_header->pdu_proto = 0x01;
+		p_header->pdu_flag = 0x00;
+		if (be16_to_cpu(skb->protocol) == ETH_P_SNAP) {
+			p_header->pdu_flag |= PDU_FIRST | PDU_CNTL;
+		} else {
+			p_header->pdu_flag |= PDU_FIRST;
+		}
+		p_header->pdu_seq = 0;
+		memcpy(skb_push(skb, PDU_HEADER_LENGTH), p_header,
+		       PDU_HEADER_LENGTH);
+
+		CTCM_PR_DEBUG("%s(%s): Put on collect_q - skb len: %04x \n"
+				"pdu header and data for up to 32 bytes:\n",
+				__func__, dev->name, skb->len);
+		CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
+
+		skb_queue_tail(&ch->collect_queue, skb);
+		ch->collect_len += skb->len;
+		kfree(p_header);
+
+		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
+			goto done;
+	}
+
+	/*
+	 * Protect skb against beeing free'd by upper
+	 * layers.
+	 */
+	refcount_inc(&skb->users);
+
+	/*
+	 * IDAL support in CTCM is broken, so we have to
+	 * care about skb's above 2G ourselves.
+	 */
+	hi = ((unsigned long)skb->tail + TH_HEADER_LENGTH) >> 31;
+	if (hi) {
+		nskb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
+		if (!nskb) {
+			goto nomem_exit;
+		} else {
+			skb_put_data(nskb, skb->data, skb->len);
+			refcount_inc(&nskb->users);
+			refcount_dec(&skb->users);
+			dev_kfree_skb_irq(skb);
+			skb = nskb;
+		}
+	}
+
+	p_header = kmalloc(PDU_HEADER_LENGTH, gfp_type());
+
+	if (!p_header)
+		goto nomem_exit;
+
+	p_header->pdu_offset = skb->len;
+	p_header->pdu_proto = 0x01;
+	p_header->pdu_flag = 0x00;
+	p_header->pdu_seq = 0;
+	if (be16_to_cpu(skb->protocol) == ETH_P_SNAP) {
+		p_header->pdu_flag |= PDU_FIRST | PDU_CNTL;
+	} else {
+		p_header->pdu_flag |= PDU_FIRST;
+	}
+	memcpy(skb_push(skb, PDU_HEADER_LENGTH), p_header, PDU_HEADER_LENGTH);
+
+	kfree(p_header);
+
+	if (ch->collect_len > 0) {
+		spin_lock_irqsave(&ch->collect_lock, saveflags);
+		skb_queue_tail(&ch->collect_queue, skb);
+		ch->collect_len += skb->len;
+		skb = skb_dequeue(&ch->collect_queue);
+		ch->collect_len -= skb->len;
+		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
+	}
+
+	p_header = (struct pdu *)skb->data;
+	p_header->pdu_flag |= PDU_LAST;
+
+	ch->prof.txlen += skb->len - PDU_HEADER_LENGTH;
+
+	header = kmalloc(TH_HEADER_LENGTH, gfp_type());
+	if (!header)
+		goto nomem_exit;
+
+	header->th_seg = 0x00;
+	header->th_ch_flag = TH_HAS_PDU;  /* Normal data */
+	header->th_blk_flag = 0x00;
+	header->th_is_xid = 0x00;          /* Just data here */
+	ch->th_seq_num++;
+	header->th_seq_num = ch->th_seq_num;
+
+	CTCM_PR_DBGDATA("%s(%s) ToVTAM_th_seq= %08x\n" ,
+		       __func__, dev->name, ch->th_seq_num);
+
+	/* put the TH on the packet */
+	memcpy(skb_push(skb, TH_HEADER_LENGTH), header, TH_HEADER_LENGTH);
+
+	kfree(header);
+
+	CTCM_PR_DBGDATA("%s(%s): skb len: %04x\n - pdu header and data for "
+			"up to 32 bytes sent to vtam:\n",
+				__func__, dev->name, skb->len);
+	CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
+
+	ch->ccw[4].count = skb->len;
+	if (set_normalized_cda(&ch->ccw[4], skb->data)) {
+		/*
+		 * idal allocation failed, try via copying to trans_skb.
+		 * trans_skb usually has a pre-allocated idal.
+		 */
+		if (ctcm_checkalloc_buffer(ch)) {
+			/*
+			 * Remove our header.
+			 * It gets added again on retransmit.
+			 */
+				goto nomem_exit;
+		}
+
+		skb_reset_tail_pointer(ch->trans_skb);
+		ch->trans_skb->len = 0;
+		ch->ccw[1].count = skb->len;
+		skb_put_data(ch->trans_skb, skb->data, skb->len);
+		refcount_dec(&skb->users);
+		dev_kfree_skb_irq(skb);
+		ccw_idx = 0;
+		CTCM_PR_DBGDATA("%s(%s): trans_skb len: %04x\n"
+				"up to 32 bytes sent to vtam:\n",
+				__func__, dev->name, ch->trans_skb->len);
+		CTCM_D3_DUMP((char *)ch->trans_skb->data,
+				min_t(int, 32, ch->trans_skb->len));
+	} else {
+		skb_queue_tail(&ch->io_queue, skb);
+		ccw_idx = 3;
+	}
+	ch->retry = 0;
+	fsm_newstate(ch->fsm, CTC_STATE_TX);
+	fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
+
+	if (do_debug_ccw)
+		ctcmpc_dumpit((char *)&ch->ccw[ccw_idx],
+					sizeof(struct ccw1) * 3);
+
+	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
+	ch->prof.send_stamp = jiffies;
+	rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx], 0, 0xff, 0);
+	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
+	if (ccw_idx == 3)
+		ch->prof.doios_single++;
+	if (rc != 0) {
+		fsm_deltimer(&ch->timer);
+		ctcm_ccw_check_rc(ch, rc, "single skb TX");
+		if (ccw_idx == 3)
+			skb_dequeue_tail(&ch->io_queue);
+	} else if (ccw_idx == 0) {
+		priv->stats.tx_packets++;
+		priv->stats.tx_bytes += skb->len - TH_HEADER_LENGTH;
+	}
+	if (ch->th_seq_num > 0xf0000000)	/* Chose at random. */
+		ctcmpc_send_sweep_req(ch);
+
+	goto done;
+nomem_exit:
+	CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_CRIT,
+			"%s(%s): MEMORY allocation ERROR\n",
+			CTCM_FUNTAIL, ch->id);
+	rc = -ENOMEM;
+	refcount_dec(&skb->users);
+	dev_kfree_skb_any(skb);
+	fsm_event(priv->mpcg->fsm, MPCG_EVENT_INOP, dev);
+done:
+	CTCM_PR_DEBUG("Exit %s(%s)\n", __func__, dev->name);
+	return rc;
+}
+
+/**
+ * Start transmission of a packet.
+ * Called from generic network device layer.
+ */
+/* first merge version - leaving both functions separated */
+static netdev_tx_t ctcm_tx(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ctcm_priv *priv = dev->ml_priv;
+
+	if (skb == NULL) {
+		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+				"%s(%s): NULL sk_buff passed",
+					CTCM_FUNTAIL, dev->name);
+		priv->stats.tx_dropped++;
+		return NETDEV_TX_OK;
+	}
+	if (skb_headroom(skb) < (LL_HEADER_LENGTH + 2)) {
+		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+			"%s(%s): Got sk_buff with head room < %ld bytes",
+			CTCM_FUNTAIL, dev->name, LL_HEADER_LENGTH + 2);
+		dev_kfree_skb(skb);
+		priv->stats.tx_dropped++;
+		return NETDEV_TX_OK;
+	}
+
+	/*
+	 * If channels are not running, try to restart them
+	 * and throw away packet.
+	 */
+	if (fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) {
+		fsm_event(priv->fsm, DEV_EVENT_START, dev);
+		dev_kfree_skb(skb);
+		priv->stats.tx_dropped++;
+		priv->stats.tx_errors++;
+		priv->stats.tx_carrier_errors++;
+		return NETDEV_TX_OK;
+	}
+
+	if (ctcm_test_and_set_busy(dev))
+		return NETDEV_TX_BUSY;
+
+	netif_trans_update(dev);
+	if (ctcm_transmit_skb(priv->channel[CTCM_WRITE], skb) != 0)
+		return NETDEV_TX_BUSY;
+	return NETDEV_TX_OK;
+}
+
+/* unmerged MPC variant of ctcm_tx */
+static netdev_tx_t ctcmpc_tx(struct sk_buff *skb, struct net_device *dev)
+{
+	int len = 0;
+	struct ctcm_priv *priv = dev->ml_priv;
+	struct mpc_group *grp  = priv->mpcg;
+	struct sk_buff *newskb = NULL;
+
+	/*
+	 * Some sanity checks ...
+	 */
+	if (skb == NULL) {
+		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
+			"%s(%s): NULL sk_buff passed",
+					CTCM_FUNTAIL, dev->name);
+		priv->stats.tx_dropped++;
+					goto done;
+	}
+	if (skb_headroom(skb) < (TH_HEADER_LENGTH + PDU_HEADER_LENGTH)) {
+		CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
+			"%s(%s): Got sk_buff with head room < %ld bytes",
+			CTCM_FUNTAIL, dev->name,
+				TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
+
+		CTCM_D3_DUMP((char *)skb->data, min_t(int, 32, skb->len));
+
+		len =  skb->len + TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
+		newskb = __dev_alloc_skb(len, gfp_type() | GFP_DMA);
+
+		if (!newskb) {
+			CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_ERROR,
+				"%s: %s: __dev_alloc_skb failed",
+						__func__, dev->name);
+
+			dev_kfree_skb_any(skb);
+			priv->stats.tx_dropped++;
+			priv->stats.tx_errors++;
+			priv->stats.tx_carrier_errors++;
+			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
+					goto done;
+		}
+		newskb->protocol = skb->protocol;
+		skb_reserve(newskb, TH_HEADER_LENGTH + PDU_HEADER_LENGTH);
+		skb_put_data(newskb, skb->data, skb->len);
+		dev_kfree_skb_any(skb);
+		skb = newskb;
+	}
+
+	/*
+	 * If channels are not running,
+	 * notify anybody about a link failure and throw
+	 * away packet.
+	 */
+	if ((fsm_getstate(priv->fsm) != DEV_STATE_RUNNING) ||
+	   (fsm_getstate(grp->fsm) <  MPCG_STATE_XID2INITW)) {
+		dev_kfree_skb_any(skb);
+		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
+			"%s(%s): inactive MPCGROUP - dropped",
+					CTCM_FUNTAIL, dev->name);
+		priv->stats.tx_dropped++;
+		priv->stats.tx_errors++;
+		priv->stats.tx_carrier_errors++;
+					goto done;
+	}
+
+	if (ctcm_test_and_set_busy(dev)) {
+		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
+			"%s(%s): device busy - dropped",
+					CTCM_FUNTAIL, dev->name);
+		dev_kfree_skb_any(skb);
+		priv->stats.tx_dropped++;
+		priv->stats.tx_errors++;
+		priv->stats.tx_carrier_errors++;
+		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
+					goto done;
+	}
+
+	netif_trans_update(dev);
+	if (ctcmpc_transmit_skb(priv->channel[CTCM_WRITE], skb) != 0) {
+		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
+			"%s(%s): device error - dropped",
+					CTCM_FUNTAIL, dev->name);
+		dev_kfree_skb_any(skb);
+		priv->stats.tx_dropped++;
+		priv->stats.tx_errors++;
+		priv->stats.tx_carrier_errors++;
+		ctcm_clear_busy(dev);
+		fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
+					goto done;
+	}
+	ctcm_clear_busy(dev);
+done:
+	if (do_debug)
+		MPC_DBF_DEV_NAME(TRACE, dev, "exit");
+
+	return NETDEV_TX_OK;	/* handle freeing of skb here */
+}
+
+
+/**
+ * Sets MTU of an interface.
+ *
+ *  dev		Pointer to interface struct.
+ *  new_mtu	The new MTU to use for this interface.
+ *
+ * returns 0 on success, -EINVAL if MTU is out of valid range.
+ *         (valid range is 576 .. 65527). If VM is on the
+ *         remote side, maximum MTU is 32760, however this is
+ *         not checked here.
+ */
+static int ctcm_change_mtu(struct net_device *dev, int new_mtu)
+{
+	struct ctcm_priv *priv;
+	int max_bufsize;
+
+	priv = dev->ml_priv;
+	max_bufsize = priv->channel[CTCM_READ]->max_bufsize;
+
+	if (IS_MPC(priv)) {
+		if (new_mtu > max_bufsize - TH_HEADER_LENGTH)
+			return -EINVAL;
+		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
+	} else {
+		if (new_mtu > max_bufsize - LL_HEADER_LENGTH - 2)
+			return -EINVAL;
+		dev->hard_header_len = LL_HEADER_LENGTH + 2;
+	}
+	dev->mtu = new_mtu;
+	return 0;
+}
+
+/**
+ * Returns interface statistics of a device.
+ *
+ *  dev		Pointer to interface struct.
+ *
+ * returns Pointer to stats struct of this interface.
+ */
+static struct net_device_stats *ctcm_stats(struct net_device *dev)
+{
+	return &((struct ctcm_priv *)dev->ml_priv)->stats;
+}
+
+static void ctcm_free_netdevice(struct net_device *dev)
+{
+	struct ctcm_priv *priv;
+	struct mpc_group *grp;
+
+	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
+			"%s(%s)", CTCM_FUNTAIL, dev->name);
+	priv = dev->ml_priv;
+	if (priv) {
+		grp = priv->mpcg;
+		if (grp) {
+			if (grp->fsm)
+				kfree_fsm(grp->fsm);
+			dev_kfree_skb(grp->xid_skb);
+			dev_kfree_skb(grp->rcvd_xid_skb);
+			tasklet_kill(&grp->mpc_tasklet2);
+			kfree(grp);
+			priv->mpcg = NULL;
+		}
+		if (priv->fsm) {
+			kfree_fsm(priv->fsm);
+			priv->fsm = NULL;
+		}
+		kfree(priv->xid);
+		priv->xid = NULL;
+	/*
+	 * Note: kfree(priv); is done in "opposite" function of
+	 * allocator function probe_device which is remove_device.
+	 */
+	}
+#ifdef MODULE
+	free_netdev(dev);
+#endif
+}
+
+struct mpc_group *ctcmpc_init_mpc_group(struct ctcm_priv *priv);
+
+static const struct net_device_ops ctcm_netdev_ops = {
+	.ndo_open		= ctcm_open,
+	.ndo_stop		= ctcm_close,
+	.ndo_get_stats		= ctcm_stats,
+	.ndo_change_mtu	   	= ctcm_change_mtu,
+	.ndo_start_xmit		= ctcm_tx,
+};
+
+static const struct net_device_ops ctcm_mpc_netdev_ops = {
+	.ndo_open		= ctcm_open,
+	.ndo_stop		= ctcm_close,
+	.ndo_get_stats		= ctcm_stats,
+	.ndo_change_mtu	   	= ctcm_change_mtu,
+	.ndo_start_xmit		= ctcmpc_tx,
+};
+
+static void ctcm_dev_setup(struct net_device *dev)
+{
+	dev->type = ARPHRD_SLIP;
+	dev->tx_queue_len = 100;
+	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
+	dev->min_mtu = 576;
+	dev->max_mtu = 65527;
+}
+
+/*
+ * Initialize everything of the net device except the name and the
+ * channel structs.
+ */
+static struct net_device *ctcm_init_netdevice(struct ctcm_priv *priv)
+{
+	struct net_device *dev;
+	struct mpc_group *grp;
+	if (!priv)
+		return NULL;
+
+	if (IS_MPC(priv))
+		dev = alloc_netdev(0, MPC_DEVICE_GENE, NET_NAME_UNKNOWN,
+				   ctcm_dev_setup);
+	else
+		dev = alloc_netdev(0, CTC_DEVICE_GENE, NET_NAME_UNKNOWN,
+				   ctcm_dev_setup);
+
+	if (!dev) {
+		CTCM_DBF_TEXT_(ERROR, CTC_DBF_CRIT,
+			"%s: MEMORY allocation ERROR",
+			CTCM_FUNTAIL);
+		return NULL;
+	}
+	dev->ml_priv = priv;
+	priv->fsm = init_fsm("ctcmdev", dev_state_names, dev_event_names,
+				CTCM_NR_DEV_STATES, CTCM_NR_DEV_EVENTS,
+				dev_fsm, dev_fsm_len, GFP_KERNEL);
+	if (priv->fsm == NULL) {
+		CTCMY_DBF_DEV(SETUP, dev, "init_fsm error");
+		free_netdev(dev);
+		return NULL;
+	}
+	fsm_newstate(priv->fsm, DEV_STATE_STOPPED);
+	fsm_settimer(priv->fsm, &priv->restart_timer);
+
+	if (IS_MPC(priv)) {
+		/*  MPC Group Initializations  */
+		grp = ctcmpc_init_mpc_group(priv);
+		if (grp == NULL) {
+			MPC_DBF_DEV(SETUP, dev, "init_mpc_group error");
+			free_netdev(dev);
+			return NULL;
+		}
+		tasklet_init(&grp->mpc_tasklet2,
+				mpc_group_ready, (unsigned long)dev);
+		dev->mtu = MPC_BUFSIZE_DEFAULT -
+				TH_HEADER_LENGTH - PDU_HEADER_LENGTH;
+
+		dev->netdev_ops = &ctcm_mpc_netdev_ops;
+		dev->hard_header_len = TH_HEADER_LENGTH + PDU_HEADER_LENGTH;
+		priv->buffer_size = MPC_BUFSIZE_DEFAULT;
+	} else {
+		dev->mtu = CTCM_BUFSIZE_DEFAULT - LL_HEADER_LENGTH - 2;
+		dev->netdev_ops = &ctcm_netdev_ops;
+		dev->hard_header_len = LL_HEADER_LENGTH + 2;
+	}
+
+	CTCMY_DBF_DEV(SETUP, dev, "finished");
+
+	return dev;
+}
+
+/**
+ * Main IRQ handler.
+ *
+ *  cdev	The ccw_device the interrupt is for.
+ *  intparm	interruption parameter.
+ *  irb		interruption response block.
+ */
+static void ctcm_irq_handler(struct ccw_device *cdev,
+				unsigned long intparm, struct irb *irb)
+{
+	struct channel		*ch;
+	struct net_device	*dev;
+	struct ctcm_priv	*priv;
+	struct ccwgroup_device	*cgdev;
+	int cstat;
+	int dstat;
+
+	CTCM_DBF_TEXT_(TRACE, CTC_DBF_DEBUG,
+		"Enter %s(%s)", CTCM_FUNTAIL, dev_name(&cdev->dev));
+
+	if (ctcm_check_irb_error(cdev, irb))
+		return;
+
+	cgdev = dev_get_drvdata(&cdev->dev);
+
+	cstat = irb->scsw.cmd.cstat;
+	dstat = irb->scsw.cmd.dstat;
+
+	/* Check for unsolicited interrupts. */
+	if (cgdev == NULL) {
+		CTCM_DBF_TEXT_(TRACE, CTC_DBF_ERROR,
+			"%s(%s) unsolicited irq: c-%02x d-%02x\n",
+			CTCM_FUNTAIL, dev_name(&cdev->dev), cstat, dstat);
+		dev_warn(&cdev->dev,
+			"The adapter received a non-specific IRQ\n");
+		return;
+	}
+
+	priv = dev_get_drvdata(&cgdev->dev);
+
+	/* Try to extract channel from driver data. */
+	if (priv->channel[CTCM_READ]->cdev == cdev)
+		ch = priv->channel[CTCM_READ];
+	else if (priv->channel[CTCM_WRITE]->cdev == cdev)
+		ch = priv->channel[CTCM_WRITE];
+	else {
+		dev_err(&cdev->dev,
+			"%s: Internal error: Can't determine channel for "
+			"interrupt device %s\n",
+			__func__, dev_name(&cdev->dev));
+			/* Explain: inconsistent internal structures */
+		return;
+	}
+
+	dev = ch->netdev;
+	if (dev == NULL) {
+		dev_err(&cdev->dev,
+			"%s Internal error: net_device is NULL, ch = 0x%p\n",
+			__func__, ch);
+			/* Explain: inconsistent internal structures */
+		return;
+	}
+
+	/* Copy interruption response block. */
+	memcpy(ch->irb, irb, sizeof(struct irb));
+
+	/* Issue error message and return on subchannel error code */
+	if (irb->scsw.cmd.cstat) {
+		fsm_event(ch->fsm, CTC_EVENT_SC_UNKNOWN, ch);
+		CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
+			"%s(%s): sub-ch check %s: cs=%02x ds=%02x",
+				CTCM_FUNTAIL, dev->name, ch->id, cstat, dstat);
+		dev_warn(&cdev->dev,
+				"A check occurred on the subchannel\n");
+		return;
+	}
+
+	/* Check the reason-code of a unit check */
+	if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
+		if ((irb->ecw[0] & ch->sense_rc) == 0)
+			/* print it only once */
+			CTCM_DBF_TEXT_(TRACE, CTC_DBF_WARN,
+				"%s(%s): sense=%02x, ds=%02x",
+				CTCM_FUNTAIL, ch->id, irb->ecw[0], dstat);
+		ccw_unit_check(ch, irb->ecw[0]);
+		return;
+	}
+	if (irb->scsw.cmd.dstat & DEV_STAT_BUSY) {
+		if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
+			fsm_event(ch->fsm, CTC_EVENT_ATTNBUSY, ch);
+		else
+			fsm_event(ch->fsm, CTC_EVENT_BUSY, ch);
+		return;
+	}
+	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
+		fsm_event(ch->fsm, CTC_EVENT_ATTN, ch);
+		return;
+	}
+	if ((irb->scsw.cmd.stctl & SCSW_STCTL_SEC_STATUS) ||
+	    (irb->scsw.cmd.stctl == SCSW_STCTL_STATUS_PEND) ||
+	    (irb->scsw.cmd.stctl ==
+	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)))
+		fsm_event(ch->fsm, CTC_EVENT_FINSTAT, ch);
+	else
+		fsm_event(ch->fsm, CTC_EVENT_IRQ, ch);
+
+}
+
+static const struct device_type ctcm_devtype = {
+	.name = "ctcm",
+	.groups = ctcm_attr_groups,
+};
+
+/**
+ * Add ctcm specific attributes.
+ * Add ctcm private data.
+ *
+ *  cgdev	pointer to ccwgroup_device just added
+ *
+ * returns 0 on success, !0 on failure.
+ */
+static int ctcm_probe_device(struct ccwgroup_device *cgdev)
+{
+	struct ctcm_priv *priv;
+
+	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
+			"%s %p",
+			__func__, cgdev);
+
+	if (!get_device(&cgdev->dev))
+		return -ENODEV;
+
+	priv = kzalloc(sizeof(struct ctcm_priv), GFP_KERNEL);
+	if (!priv) {
+		CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+			"%s: memory allocation failure",
+			CTCM_FUNTAIL);
+		put_device(&cgdev->dev);
+		return -ENOMEM;
+	}
+	priv->buffer_size = CTCM_BUFSIZE_DEFAULT;
+	cgdev->cdev[0]->handler = ctcm_irq_handler;
+	cgdev->cdev[1]->handler = ctcm_irq_handler;
+	dev_set_drvdata(&cgdev->dev, priv);
+	cgdev->dev.type = &ctcm_devtype;
+
+	return 0;
+}
+
+/**
+ * Add a new channel to the list of channels.
+ * Keeps the channel list sorted.
+ *
+ *  cdev	The ccw_device to be added.
+ *  type	The type class of the new channel.
+ *  priv	Points to the private data of the ccwgroup_device.
+ *
+ * returns 0 on success, !0 on error.
+ */
+static int add_channel(struct ccw_device *cdev, enum ctcm_channel_types type,
+				struct ctcm_priv *priv)
+{
+	struct channel **c = &channels;
+	struct channel *ch;
+	int ccw_num;
+	int rc = 0;
+
+	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
+		"%s(%s), type %d, proto %d",
+			__func__, dev_name(&cdev->dev),	type, priv->protocol);
+
+	ch = kzalloc(sizeof(struct channel), GFP_KERNEL);
+	if (ch == NULL)
+		return -ENOMEM;
+
+	ch->protocol = priv->protocol;
+	if (IS_MPC(priv)) {
+		ch->discontact_th = kzalloc(TH_HEADER_LENGTH, gfp_type());
+		if (ch->discontact_th == NULL)
+					goto nomem_return;
+
+		ch->discontact_th->th_blk_flag = TH_DISCONTACT;
+		tasklet_init(&ch->ch_disc_tasklet,
+			mpc_action_send_discontact, (unsigned long)ch);
+
+		tasklet_init(&ch->ch_tasklet, ctcmpc_bh, (unsigned long)ch);
+		ch->max_bufsize = (MPC_BUFSIZE_DEFAULT - 35);
+		ccw_num = 17;
+	} else
+		ccw_num = 8;
+
+	ch->ccw = kcalloc(ccw_num, sizeof(struct ccw1), GFP_KERNEL | GFP_DMA);
+	if (ch->ccw == NULL)
+					goto nomem_return;
+
+	ch->cdev = cdev;
+	snprintf(ch->id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev->dev));
+	ch->type = type;
+
+	/**
+	 * "static" ccws are used in the following way:
+	 *
+	 * ccw[0..2] (Channel program for generic I/O):
+	 *           0: prepare
+	 *           1: read or write (depending on direction) with fixed
+	 *              buffer (idal allocated once when buffer is allocated)
+	 *           2: nop
+	 * ccw[3..5] (Channel program for direct write of packets)
+	 *           3: prepare
+	 *           4: write (idal allocated on every write).
+	 *           5: nop
+	 * ccw[6..7] (Channel program for initial channel setup):
+	 *           6: set extended mode
+	 *           7: nop
+	 *
+	 * ch->ccw[0..5] are initialized in ch_action_start because
+	 * the channel's direction is yet unknown here.
+	 *
+	 * ccws used for xid2 negotiations
+	 *  ch-ccw[8-14] need to be used for the XID exchange either
+	 *    X side XID2 Processing
+	 *       8:  write control
+	 *       9:  write th
+	 *	     10: write XID
+	 *	     11: read th from secondary
+	 *	     12: read XID   from secondary
+	 *	     13: read 4 byte ID
+	 *	     14: nop
+	 *    Y side XID Processing
+	 *	     8:  sense
+	 *       9:  read th
+	 *	     10: read XID
+	 *	     11: write th
+	 *	     12: write XID
+	 *	     13: write 4 byte ID
+	 *	     14: nop
+	 *
+	 *  ccws used for double noop due to VM timing issues
+	 *  which result in unrecoverable Busy on channel
+	 *       15: nop
+	 *       16: nop
+	 */
+	ch->ccw[6].cmd_code	= CCW_CMD_SET_EXTENDED;
+	ch->ccw[6].flags	= CCW_FLAG_SLI;
+
+	ch->ccw[7].cmd_code	= CCW_CMD_NOOP;
+	ch->ccw[7].flags	= CCW_FLAG_SLI;
+
+	if (IS_MPC(priv)) {
+		ch->ccw[15].cmd_code = CCW_CMD_WRITE;
+		ch->ccw[15].flags    = CCW_FLAG_SLI | CCW_FLAG_CC;
+		ch->ccw[15].count    = TH_HEADER_LENGTH;
+		ch->ccw[15].cda      = virt_to_phys(ch->discontact_th);
+
+		ch->ccw[16].cmd_code = CCW_CMD_NOOP;
+		ch->ccw[16].flags    = CCW_FLAG_SLI;
+
+		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
+				ctc_ch_event_names, CTC_MPC_NR_STATES,
+				CTC_MPC_NR_EVENTS, ctcmpc_ch_fsm,
+				mpc_ch_fsm_len, GFP_KERNEL);
+	} else {
+		ch->fsm = init_fsm(ch->id, ctc_ch_state_names,
+				ctc_ch_event_names, CTC_NR_STATES,
+				CTC_NR_EVENTS, ch_fsm,
+				ch_fsm_len, GFP_KERNEL);
+	}
+	if (ch->fsm == NULL)
+				goto nomem_return;
+
+	fsm_newstate(ch->fsm, CTC_STATE_IDLE);
+
+	ch->irb = kzalloc(sizeof(struct irb), GFP_KERNEL);
+	if (ch->irb == NULL)
+				goto nomem_return;
+
+	while (*c && ctcm_less_than((*c)->id, ch->id))
+		c = &(*c)->next;
+
+	if (*c && (!strncmp((*c)->id, ch->id, CTCM_ID_SIZE))) {
+		CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
+				"%s (%s) already in list, using old entry",
+				__func__, (*c)->id);
+
+				goto free_return;
+	}
+
+	spin_lock_init(&ch->collect_lock);
+
+	fsm_settimer(ch->fsm, &ch->timer);
+	skb_queue_head_init(&ch->io_queue);
+	skb_queue_head_init(&ch->collect_queue);
+
+	if (IS_MPC(priv)) {
+		fsm_settimer(ch->fsm, &ch->sweep_timer);
+		skb_queue_head_init(&ch->sweep_queue);
+	}
+	ch->next = *c;
+	*c = ch;
+	return 0;
+
+nomem_return:
+	rc = -ENOMEM;
+
+free_return:	/* note that all channel pointers are 0 or valid */
+	kfree(ch->ccw);
+	kfree(ch->discontact_th);
+	kfree_fsm(ch->fsm);
+	kfree(ch->irb);
+	kfree(ch);
+	return rc;
+}
+
+/*
+ * Return type of a detected device.
+ */
+static enum ctcm_channel_types get_channel_type(struct ccw_device_id *id)
+{
+	enum ctcm_channel_types type;
+	type = (enum ctcm_channel_types)id->driver_info;
+
+	if (type == ctcm_channel_type_ficon)
+		type = ctcm_channel_type_escon;
+
+	return type;
+}
+
+/**
+ *
+ * Setup an interface.
+ *
+ *  cgdev	Device to be setup.
+ *
+ * returns 0 on success, !0 on failure.
+ */
+static int ctcm_new_device(struct ccwgroup_device *cgdev)
+{
+	char read_id[CTCM_ID_SIZE];
+	char write_id[CTCM_ID_SIZE];
+	int direction;
+	enum ctcm_channel_types type;
+	struct ctcm_priv *priv;
+	struct net_device *dev;
+	struct ccw_device *cdev0;
+	struct ccw_device *cdev1;
+	struct channel *readc;
+	struct channel *writec;
+	int ret;
+	int result;
+
+	priv = dev_get_drvdata(&cgdev->dev);
+	if (!priv) {
+		result = -ENODEV;
+		goto out_err_result;
+	}
+
+	cdev0 = cgdev->cdev[0];
+	cdev1 = cgdev->cdev[1];
+
+	type = get_channel_type(&cdev0->id);
+
+	snprintf(read_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev0->dev));
+	snprintf(write_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev1->dev));
+
+	ret = add_channel(cdev0, type, priv);
+	if (ret) {
+		result = ret;
+		goto out_err_result;
+	}
+	ret = add_channel(cdev1, type, priv);
+	if (ret) {
+		result = ret;
+		goto out_remove_channel1;
+	}
+
+	ret = ccw_device_set_online(cdev0);
+	if (ret != 0) {
+		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
+			"%s(%s) set_online rc=%d",
+				CTCM_FUNTAIL, read_id, ret);
+		result = -EIO;
+		goto out_remove_channel2;
+	}
+
+	ret = ccw_device_set_online(cdev1);
+	if (ret != 0) {
+		CTCM_DBF_TEXT_(TRACE, CTC_DBF_NOTICE,
+			"%s(%s) set_online rc=%d",
+				CTCM_FUNTAIL, write_id, ret);
+
+		result = -EIO;
+		goto out_ccw1;
+	}
+
+	dev = ctcm_init_netdevice(priv);
+	if (dev == NULL) {
+		result = -ENODEV;
+		goto out_ccw2;
+	}
+
+	for (direction = CTCM_READ; direction <= CTCM_WRITE; direction++) {
+		priv->channel[direction] =
+			channel_get(type, direction == CTCM_READ ?
+				read_id : write_id, direction);
+		if (priv->channel[direction] == NULL) {
+			if (direction == CTCM_WRITE)
+				channel_free(priv->channel[CTCM_READ]);
+			result = -ENODEV;
+			goto out_dev;
+		}
+		priv->channel[direction]->netdev = dev;
+		priv->channel[direction]->protocol = priv->protocol;
+		priv->channel[direction]->max_bufsize = priv->buffer_size;
+	}
+	/* sysfs magic */
+	SET_NETDEV_DEV(dev, &cgdev->dev);
+
+	if (register_netdev(dev)) {
+		result = -ENODEV;
+		goto out_dev;
+	}
+
+	strlcpy(priv->fsm->name, dev->name, sizeof(priv->fsm->name));
+
+	dev_info(&dev->dev,
+		"setup OK : r/w = %s/%s, protocol : %d\n",
+			priv->channel[CTCM_READ]->id,
+			priv->channel[CTCM_WRITE]->id, priv->protocol);
+
+	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
+		"setup(%s) OK : r/w = %s/%s, protocol : %d", dev->name,
+			priv->channel[CTCM_READ]->id,
+			priv->channel[CTCM_WRITE]->id, priv->protocol);
+
+	return 0;
+out_dev:
+	ctcm_free_netdevice(dev);
+out_ccw2:
+	ccw_device_set_offline(cgdev->cdev[1]);
+out_ccw1:
+	ccw_device_set_offline(cgdev->cdev[0]);
+out_remove_channel2:
+	readc = channel_get(type, read_id, CTCM_READ);
+	channel_remove(readc);
+out_remove_channel1:
+	writec = channel_get(type, write_id, CTCM_WRITE);
+	channel_remove(writec);
+out_err_result:
+	return result;
+}
+
+/**
+ * Shutdown an interface.
+ *
+ *  cgdev	Device to be shut down.
+ *
+ * returns 0 on success, !0 on failure.
+ */
+static int ctcm_shutdown_device(struct ccwgroup_device *cgdev)
+{
+	struct ctcm_priv *priv;
+	struct net_device *dev;
+
+	priv = dev_get_drvdata(&cgdev->dev);
+	if (!priv)
+		return -ENODEV;
+
+	if (priv->channel[CTCM_READ]) {
+		dev = priv->channel[CTCM_READ]->netdev;
+		CTCM_DBF_DEV(SETUP, dev, "");
+		/* Close the device */
+		ctcm_close(dev);
+		dev->flags &= ~IFF_RUNNING;
+		channel_free(priv->channel[CTCM_READ]);
+	} else
+		dev = NULL;
+
+	if (priv->channel[CTCM_WRITE])
+		channel_free(priv->channel[CTCM_WRITE]);
+
+	if (dev) {
+		unregister_netdev(dev);
+		ctcm_free_netdevice(dev);
+	}
+
+	if (priv->fsm)
+		kfree_fsm(priv->fsm);
+
+	ccw_device_set_offline(cgdev->cdev[1]);
+	ccw_device_set_offline(cgdev->cdev[0]);
+	channel_remove(priv->channel[CTCM_READ]);
+	channel_remove(priv->channel[CTCM_WRITE]);
+	priv->channel[CTCM_READ] = priv->channel[CTCM_WRITE] = NULL;
+
+	return 0;
+
+}
+
+
+static void ctcm_remove_device(struct ccwgroup_device *cgdev)
+{
+	struct ctcm_priv *priv = dev_get_drvdata(&cgdev->dev);
+
+	CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO,
+			"removing device %p, proto : %d",
+			cgdev, priv->protocol);
+
+	if (cgdev->state == CCWGROUP_ONLINE)
+		ctcm_shutdown_device(cgdev);
+	dev_set_drvdata(&cgdev->dev, NULL);
+	kfree(priv);
+	put_device(&cgdev->dev);
+}
+
+static struct ccw_device_id ctcm_ids[] = {
+	{CCW_DEVICE(0x3088, 0x08), .driver_info = ctcm_channel_type_parallel},
+	{CCW_DEVICE(0x3088, 0x1e), .driver_info = ctcm_channel_type_ficon},
+	{CCW_DEVICE(0x3088, 0x1f), .driver_info = ctcm_channel_type_escon},
+	{},
+};
+MODULE_DEVICE_TABLE(ccw, ctcm_ids);
+
+static struct ccw_driver ctcm_ccw_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "ctcm",
+	},
+	.ids	= ctcm_ids,
+	.probe	= ccwgroup_probe_ccwdev,
+	.remove	= ccwgroup_remove_ccwdev,
+	.int_class = IRQIO_CTC,
+};
+
+static struct ccwgroup_driver ctcm_group_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= CTC_DRIVER_NAME,
+	},
+	.ccw_driver  = &ctcm_ccw_driver,
+	.setup	     = ctcm_probe_device,
+	.remove      = ctcm_remove_device,
+	.set_online  = ctcm_new_device,
+	.set_offline = ctcm_shutdown_device,
+};
+
+static ssize_t group_store(struct device_driver *ddrv, const char *buf,
+			   size_t count)
+{
+	int err;
+
+	err = ccwgroup_create_dev(ctcm_root_dev, &ctcm_group_driver, 2, buf);
+	return err ? err : count;
+}
+static DRIVER_ATTR_WO(group);
+
+static struct attribute *ctcm_drv_attrs[] = {
+	&driver_attr_group.attr,
+	NULL,
+};
+static struct attribute_group ctcm_drv_attr_group = {
+	.attrs = ctcm_drv_attrs,
+};
+static const struct attribute_group *ctcm_drv_attr_groups[] = {
+	&ctcm_drv_attr_group,
+	NULL,
+};
+
+/*
+ * Module related routines
+ */
+
+/*
+ * Prepare to be unloaded. Free IRQ's and release all resources.
+ * This is called just before this module is unloaded. It is
+ * not called, if the usage count is !0, so we don't need to check
+ * for that.
+ */
+static void __exit ctcm_exit(void)
+{
+	ccwgroup_driver_unregister(&ctcm_group_driver);
+	ccw_driver_unregister(&ctcm_ccw_driver);
+	root_device_unregister(ctcm_root_dev);
+	ctcm_unregister_dbf_views();
+	pr_info("CTCM driver unloaded\n");
+}
+
+/*
+ * Print Banner.
+ */
+static void print_banner(void)
+{
+	pr_info("CTCM driver initialized\n");
+}
+
+/**
+ * Initialize module.
+ * This is called just after the module is loaded.
+ *
+ * returns 0 on success, !0 on error.
+ */
+static int __init ctcm_init(void)
+{
+	int ret;
+
+	channels = NULL;
+
+	ret = ctcm_register_dbf_views();
+	if (ret)
+		goto out_err;
+	ctcm_root_dev = root_device_register("ctcm");
+	ret = PTR_ERR_OR_ZERO(ctcm_root_dev);
+	if (ret)
+		goto register_err;
+	ret = ccw_driver_register(&ctcm_ccw_driver);
+	if (ret)
+		goto ccw_err;
+	ctcm_group_driver.driver.groups = ctcm_drv_attr_groups;
+	ret = ccwgroup_driver_register(&ctcm_group_driver);
+	if (ret)
+		goto ccwgroup_err;
+	print_banner();
+	return 0;
+
+ccwgroup_err:
+	ccw_driver_unregister(&ctcm_ccw_driver);
+ccw_err:
+	root_device_unregister(ctcm_root_dev);
+register_err:
+	ctcm_unregister_dbf_views();
+out_err:
+	pr_err("%s / Initializing the ctcm device driver failed, ret = %d\n",
+		__func__, ret);
+	return ret;
+}
+
+module_init(ctcm_init);
+module_exit(ctcm_exit);
+
+MODULE_AUTHOR("Peter Tiedemann <ptiedem@de.ibm.com>");
+MODULE_DESCRIPTION("Network driver for S/390 CTC + CTCMPC (SNA)");
+MODULE_LICENSE("GPL");
+