Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / s390 / net / ctcm_main.c
diff --git a/kernel/drivers/s390/net/ctcm_main.c b/kernel/drivers/s390/net/ctcm_main.c
new file mode 100644 (file)
index 0000000..05c37d6
--- /dev/null
@@ -0,0 +1,1873 @@
+/*
+ * 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 = ntohs(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 inline 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 {
+                       atomic_inc(&skb->users);
+                       header.length = l;
+                       header.type = 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.
+        */
+       atomic_inc(&skb->users);
+       ch->prof.txlen += skb->len;
+       header.length = skb->len + LL_HEADER_LENGTH;
+       header.type = 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) {
+                       atomic_dec(&skb->users);
+                       skb_pull(skb, LL_HEADER_LENGTH + 2);
+                       ctcm_clear_busy(ch->netdev);
+                       return -ENOMEM;
+               } else {
+                       memcpy(skb_put(nskb, skb->len), skb->data, skb->len);
+                       atomic_inc(&nskb->users);
+                       atomic_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.
+                        */
+                       atomic_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);
+               atomic_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],
+                                       (unsigned long)ch, 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;
+
+       memcpy(skb_put(sweep_skb, TH_SWEEP_LENGTH), header, TH_SWEEP_LENGTH);
+
+       kfree(header);
+
+       dev->trans_start = jiffies;
+       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);
+               atomic_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 (skb->protocol == ntohs(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.
+        */
+       atomic_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 {
+                       memcpy(skb_put(nskb, skb->len), skb->data, skb->len);
+                       atomic_inc(&nskb->users);
+                       atomic_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 (skb->protocol == ntohs(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;
+               memcpy(skb_put(ch->trans_skb, skb->len), skb->data, skb->len);
+               atomic_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],
+                                       (unsigned long)ch, 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;
+       atomic_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.
+ *
+ *  skb                Pointer to buffer containing the packet.
+ *  dev                Pointer to interface struct.
+ *
+ * returns 0 if packet consumed, !0 if packet rejected.
+ *         Note: If we return !0, then the packet is free'd by
+ *               the generic network layer.
+ */
+/* first merge version - leaving both functions separated */
+static int 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;
+
+       dev->trans_start = jiffies;
+       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 int 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);
+               memcpy(skb_put(newskb, skb->len), 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;
+       }
+
+       dev->trans_start = jiffies;
+       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;
+
+       if (new_mtu < 576 || new_mtu > 65527)
+               return -EINVAL;
+
+       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);
+                       if (grp->xid_skb)
+                               dev_kfree_skb(grp->xid_skb);
+                       if (grp->rcvd_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,
+};
+
+void static ctcm_dev_setup(struct net_device *dev)
+{
+       dev->type = ARPHRD_SLIP;
+       dev->tx_queue_len = 100;
+       dev->flags = IFF_POINTOPOINT | IFF_NOARP;
+}
+
+/*
+ * 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 = kzalloc(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]);
+                       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]);
+
+       if (priv->channel[CTCM_READ])
+               channel_remove(priv->channel[CTCM_READ]);
+       if (priv->channel[CTCM_WRITE])
+               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 int ctcm_pm_suspend(struct ccwgroup_device *gdev)
+{
+       struct ctcm_priv *priv = dev_get_drvdata(&gdev->dev);
+
+       if (gdev->state == CCWGROUP_OFFLINE)
+               return 0;
+       netif_device_detach(priv->channel[CTCM_READ]->netdev);
+       ctcm_close(priv->channel[CTCM_READ]->netdev);
+       if (!wait_event_timeout(priv->fsm->wait_q,
+           fsm_getstate(priv->fsm) == DEV_STATE_STOPPED, CTCM_TIME_5_SEC)) {
+               netif_device_attach(priv->channel[CTCM_READ]->netdev);
+               return -EBUSY;
+       }
+       ccw_device_set_offline(gdev->cdev[1]);
+       ccw_device_set_offline(gdev->cdev[0]);
+       return 0;
+}
+
+static int ctcm_pm_resume(struct ccwgroup_device *gdev)
+{
+       struct ctcm_priv *priv = dev_get_drvdata(&gdev->dev);
+       int rc;
+
+       if (gdev->state == CCWGROUP_OFFLINE)
+               return 0;
+       rc = ccw_device_set_online(gdev->cdev[1]);
+       if (rc)
+               goto err_out;
+       rc = ccw_device_set_online(gdev->cdev[0]);
+       if (rc)
+               goto err_out;
+       ctcm_open(priv->channel[CTCM_READ]->netdev);
+err_out:
+       netif_device_attach(priv->channel[CTCM_READ]->netdev);
+       return rc;
+}
+
+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,
+       },
+       .setup       = ctcm_probe_device,
+       .remove      = ctcm_remove_device,
+       .set_online  = ctcm_new_device,
+       .set_offline = ctcm_shutdown_device,
+       .freeze      = ctcm_pm_suspend,
+       .thaw        = ctcm_pm_resume,
+       .restore     = ctcm_pm_resume,
+};
+
+static ssize_t ctcm_driver_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(group, 0200, NULL, ctcm_driver_group_store);
+
+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");
+