Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 2216 insertions, 0 deletions

diff --git a/drivers/s390/net/netiucv.c b/drivers/s390/net/netiucv.c
new file mode 100644
index 000000000..5ce2424ca
--- /dev/null
+++ b/drivers/s390/net/netiucv.c
@@ -0,0 +1,2216 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IUCV network driver
+ *
+ * Copyright IBM Corp. 2001, 2009
+ *
+ * Author(s):
+ *	Original netiucv driver:
+ *		Fritz Elfert (elfert@de.ibm.com, felfert@millenux.com)
+ *	Sysfs integration and all bugs therein:
+ *		Cornelia Huck (cornelia.huck@de.ibm.com)
+ *	PM functions:
+ *		Ursula Braun (ursula.braun@de.ibm.com)
+ *
+ * Documentation used:
+ *  the source of the original IUCV driver by:
+ *    Stefan Hegewald <hegewald@de.ibm.com>
+ *    Hartmut Penner <hpenner@de.ibm.com>
+ *    Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+ *    Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *    Alan Altmark (Alan_Altmark@us.ibm.com)  Sept. 2000
+ */
+
+#define KMSG_COMPONENT "netiucv"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#undef DEBUG
+
+#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/device.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 <asm/io.h>
+#include <linux/uaccess.h>
+#include <asm/ebcdic.h>
+
+#include <net/iucv/iucv.h>
+#include "fsm.h"
+
+MODULE_AUTHOR
+    ("(C) 2001 IBM Corporation by Fritz Elfert (felfert@millenux.com)");
+MODULE_DESCRIPTION ("Linux for S/390 IUCV network driver");
+
+/**
+ * Debug Facility stuff
+ */
+#define IUCV_DBF_SETUP_NAME "iucv_setup"
+#define IUCV_DBF_SETUP_LEN 64
+#define IUCV_DBF_SETUP_PAGES 2
+#define IUCV_DBF_SETUP_NR_AREAS 1
+#define IUCV_DBF_SETUP_LEVEL 3
+
+#define IUCV_DBF_DATA_NAME "iucv_data"
+#define IUCV_DBF_DATA_LEN 128
+#define IUCV_DBF_DATA_PAGES 2
+#define IUCV_DBF_DATA_NR_AREAS 1
+#define IUCV_DBF_DATA_LEVEL 2
+
+#define IUCV_DBF_TRACE_NAME "iucv_trace"
+#define IUCV_DBF_TRACE_LEN 16
+#define IUCV_DBF_TRACE_PAGES 4
+#define IUCV_DBF_TRACE_NR_AREAS 1
+#define IUCV_DBF_TRACE_LEVEL 3
+
+#define IUCV_DBF_TEXT(name,level,text) \
+	do { \
+		debug_text_event(iucv_dbf_##name,level,text); \
+	} while (0)
+
+#define IUCV_DBF_HEX(name,level,addr,len) \
+	do { \
+		debug_event(iucv_dbf_##name,level,(void*)(addr),len); \
+	} while (0)
+
+DECLARE_PER_CPU(char[256], iucv_dbf_txt_buf);
+
+#define IUCV_DBF_TEXT_(name, level, text...) \
+	do { \
+		if (debug_level_enabled(iucv_dbf_##name, level)) { \
+			char* __buf = get_cpu_var(iucv_dbf_txt_buf); \
+			sprintf(__buf, text); \
+			debug_text_event(iucv_dbf_##name, level, __buf); \
+			put_cpu_var(iucv_dbf_txt_buf); \
+		} \
+	} while (0)
+
+#define IUCV_DBF_SPRINTF(name,level,text...) \
+	do { \
+		debug_sprintf_event(iucv_dbf_trace, level, ##text ); \
+		debug_sprintf_event(iucv_dbf_trace, level, text ); \
+	} while (0)
+
+/**
+ * some more debug stuff
+ */
+#define PRINTK_HEADER " iucv: "       /* for debugging */
+
+/* dummy device to make sure netiucv_pm functions are called */
+static struct device *netiucv_dev;
+
+static int netiucv_pm_prepare(struct device *);
+static void netiucv_pm_complete(struct device *);
+static int netiucv_pm_freeze(struct device *);
+static int netiucv_pm_restore_thaw(struct device *);
+
+static const struct dev_pm_ops netiucv_pm_ops = {
+	.prepare = netiucv_pm_prepare,
+	.complete = netiucv_pm_complete,
+	.freeze = netiucv_pm_freeze,
+	.thaw = netiucv_pm_restore_thaw,
+	.restore = netiucv_pm_restore_thaw,
+};
+
+static struct device_driver netiucv_driver = {
+	.owner = THIS_MODULE,
+	.name = "netiucv",
+	.bus  = &iucv_bus,
+	.pm = &netiucv_pm_ops,
+};
+
+static int netiucv_callback_connreq(struct iucv_path *, u8 *, u8 *);
+static void netiucv_callback_connack(struct iucv_path *, u8 *);
+static void netiucv_callback_connrej(struct iucv_path *, u8 *);
+static void netiucv_callback_connsusp(struct iucv_path *, u8 *);
+static void netiucv_callback_connres(struct iucv_path *, u8 *);
+static void netiucv_callback_rx(struct iucv_path *, struct iucv_message *);
+static void netiucv_callback_txdone(struct iucv_path *, struct iucv_message *);
+
+static struct iucv_handler netiucv_handler = {
+	.path_pending	  = netiucv_callback_connreq,
+	.path_complete	  = netiucv_callback_connack,
+	.path_severed	  = netiucv_callback_connrej,
+	.path_quiesced	  = netiucv_callback_connsusp,
+	.path_resumed	  = netiucv_callback_connres,
+	.message_pending  = netiucv_callback_rx,
+	.message_complete = netiucv_callback_txdone
+};
+
+/**
+ * Per connection profiling data
+ */
+struct connection_profile {
+	unsigned long maxmulti;
+	unsigned long maxcqueue;
+	unsigned long doios_single;
+	unsigned long doios_multi;
+	unsigned long txlen;
+	unsigned long tx_time;
+	unsigned long send_stamp;
+	unsigned long tx_pending;
+	unsigned long tx_max_pending;
+};
+
+/**
+ * Representation of one iucv connection
+ */
+struct iucv_connection {
+	struct list_head	  list;
+	struct iucv_path	  *path;
+	struct sk_buff            *rx_buff;
+	struct sk_buff            *tx_buff;
+	struct sk_buff_head       collect_queue;
+	struct sk_buff_head	  commit_queue;
+	spinlock_t                collect_lock;
+	int                       collect_len;
+	int                       max_buffsize;
+	fsm_timer                 timer;
+	fsm_instance              *fsm;
+	struct net_device         *netdev;
+	struct connection_profile prof;
+	char                      userid[9];
+	char			  userdata[17];
+};
+
+/**
+ * Linked list of all connection structs.
+ */
+static LIST_HEAD(iucv_connection_list);
+static DEFINE_RWLOCK(iucv_connection_rwlock);
+
+/**
+ * Representation of event-data for the
+ * connection state machine.
+ */
+struct iucv_event {
+	struct iucv_connection *conn;
+	void                   *data;
+};
+
+/**
+ * Private part of the network device structure
+ */
+struct netiucv_priv {
+	struct net_device_stats stats;
+	unsigned long           tbusy;
+	fsm_instance            *fsm;
+        struct iucv_connection  *conn;
+	struct device           *dev;
+	int			 pm_state;
+};
+
+/**
+ * Link level header for a packet.
+ */
+struct ll_header {
+	u16 next;
+};
+
+#define NETIUCV_HDRLEN		 (sizeof(struct ll_header))
+#define NETIUCV_BUFSIZE_MAX	 65537
+#define NETIUCV_BUFSIZE_DEFAULT  NETIUCV_BUFSIZE_MAX
+#define NETIUCV_MTU_MAX          (NETIUCV_BUFSIZE_MAX - NETIUCV_HDRLEN)
+#define NETIUCV_MTU_DEFAULT      9216
+#define NETIUCV_QUEUELEN_DEFAULT 50
+#define NETIUCV_TIMEOUT_5SEC     5000
+
+/**
+ * Compatibility macros for busy handling
+ * of network devices.
+ */
+static void netiucv_clear_busy(struct net_device *dev)
+{
+	struct netiucv_priv *priv = netdev_priv(dev);
+	clear_bit(0, &priv->tbusy);
+	netif_wake_queue(dev);
+}
+
+static int netiucv_test_and_set_busy(struct net_device *dev)
+{
+	struct netiucv_priv *priv = netdev_priv(dev);
+	netif_stop_queue(dev);
+	return test_and_set_bit(0, &priv->tbusy);
+}
+
+static u8 iucvMagic_ascii[16] = {
+	0x30, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+	0x30, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20
+};
+
+static u8 iucvMagic_ebcdic[16] = {
+	0xF0, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+	0xF0, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40
+};
+
+/**
+ * Convert an iucv userId to its printable
+ * form (strip whitespace at end).
+ *
+ * @param An iucv userId
+ *
+ * @returns The printable string (static data!!)
+ */
+static char *netiucv_printname(char *name, int len)
+{
+	static char tmp[17];
+	char *p = tmp;
+	memcpy(tmp, name, len);
+	tmp[len] = '\0';
+	while (*p && ((p - tmp) < len) && (!isspace(*p)))
+		p++;
+	*p = '\0';
+	return tmp;
+}
+
+static char *netiucv_printuser(struct iucv_connection *conn)
+{
+	static char tmp_uid[9];
+	static char tmp_udat[17];
+	static char buf[100];
+
+	if (memcmp(conn->userdata, iucvMagic_ebcdic, 16)) {
+		tmp_uid[8] = '\0';
+		tmp_udat[16] = '\0';
+		memcpy(tmp_uid, netiucv_printname(conn->userid, 8), 8);
+		memcpy(tmp_udat, conn->userdata, 16);
+		EBCASC(tmp_udat, 16);
+		memcpy(tmp_udat, netiucv_printname(tmp_udat, 16), 16);
+		sprintf(buf, "%s.%s", tmp_uid, tmp_udat);
+		return buf;
+	} else
+		return netiucv_printname(conn->userid, 8);
+}
+
+/**
+ * States of the interface statemachine.
+ */
+enum dev_states {
+	DEV_STATE_STOPPED,
+	DEV_STATE_STARTWAIT,
+	DEV_STATE_STOPWAIT,
+	DEV_STATE_RUNNING,
+	/**
+	 * MUST be always the last element!!
+	 */
+	NR_DEV_STATES
+};
+
+static const char *dev_state_names[] = {
+	"Stopped",
+	"StartWait",
+	"StopWait",
+	"Running",
+};
+
+/**
+ * Events of the interface statemachine.
+ */
+enum dev_events {
+	DEV_EVENT_START,
+	DEV_EVENT_STOP,
+	DEV_EVENT_CONUP,
+	DEV_EVENT_CONDOWN,
+	/**
+	 * MUST be always the last element!!
+	 */
+	NR_DEV_EVENTS
+};
+
+static const char *dev_event_names[] = {
+	"Start",
+	"Stop",
+	"Connection up",
+	"Connection down",
+};
+
+/**
+ * Events of the connection statemachine
+ */
+enum conn_events {
+	/**
+	 * Events, representing callbacks from
+	 * lowlevel iucv layer)
+	 */
+	CONN_EVENT_CONN_REQ,
+	CONN_EVENT_CONN_ACK,
+	CONN_EVENT_CONN_REJ,
+	CONN_EVENT_CONN_SUS,
+	CONN_EVENT_CONN_RES,
+	CONN_EVENT_RX,
+	CONN_EVENT_TXDONE,
+
+	/**
+	 * Events, representing errors return codes from
+	 * calls to lowlevel iucv layer
+	 */
+
+	/**
+	 * Event, representing timer expiry.
+	 */
+	CONN_EVENT_TIMER,
+
+	/**
+	 * Events, representing commands from upper levels.
+	 */
+	CONN_EVENT_START,
+	CONN_EVENT_STOP,
+
+	/**
+	 * MUST be always the last element!!
+	 */
+	NR_CONN_EVENTS,
+};
+
+static const char *conn_event_names[] = {
+	"Remote connection request",
+	"Remote connection acknowledge",
+	"Remote connection reject",
+	"Connection suspended",
+	"Connection resumed",
+	"Data received",
+	"Data sent",
+
+	"Timer",
+
+	"Start",
+	"Stop",
+};
+
+/**
+ * States of the connection statemachine.
+ */
+enum conn_states {
+	/**
+	 * Connection not assigned to any device,
+	 * initial state, invalid
+	 */
+	CONN_STATE_INVALID,
+
+	/**
+	 * Userid assigned but not operating
+	 */
+	CONN_STATE_STOPPED,
+
+	/**
+	 * Connection registered,
+	 * no connection request sent yet,
+	 * no connection request received
+	 */
+	CONN_STATE_STARTWAIT,
+
+	/**
+	 * Connection registered and connection request sent,
+	 * no acknowledge and no connection request received yet.
+	 */
+	CONN_STATE_SETUPWAIT,
+
+	/**
+	 * Connection up and running idle
+	 */
+	CONN_STATE_IDLE,
+
+	/**
+	 * Data sent, awaiting CONN_EVENT_TXDONE
+	 */
+	CONN_STATE_TX,
+
+	/**
+	 * Error during registration.
+	 */
+	CONN_STATE_REGERR,
+
+	/**
+	 * Error during registration.
+	 */
+	CONN_STATE_CONNERR,
+
+	/**
+	 * MUST be always the last element!!
+	 */
+	NR_CONN_STATES,
+};
+
+static const char *conn_state_names[] = {
+	"Invalid",
+	"Stopped",
+	"StartWait",
+	"SetupWait",
+	"Idle",
+	"TX",
+	"Terminating",
+	"Registration error",
+	"Connect error",
+};
+
+
+/**
+ * Debug Facility Stuff
+ */
+static debug_info_t *iucv_dbf_setup = NULL;
+static debug_info_t *iucv_dbf_data = NULL;
+static debug_info_t *iucv_dbf_trace = NULL;
+
+DEFINE_PER_CPU(char[256], iucv_dbf_txt_buf);
+
+static void iucv_unregister_dbf_views(void)
+{
+	debug_unregister(iucv_dbf_setup);
+	debug_unregister(iucv_dbf_data);
+	debug_unregister(iucv_dbf_trace);
+}
+static int iucv_register_dbf_views(void)
+{
+	iucv_dbf_setup = debug_register(IUCV_DBF_SETUP_NAME,
+					IUCV_DBF_SETUP_PAGES,
+					IUCV_DBF_SETUP_NR_AREAS,
+					IUCV_DBF_SETUP_LEN);
+	iucv_dbf_data = debug_register(IUCV_DBF_DATA_NAME,
+				       IUCV_DBF_DATA_PAGES,
+				       IUCV_DBF_DATA_NR_AREAS,
+				       IUCV_DBF_DATA_LEN);
+	iucv_dbf_trace = debug_register(IUCV_DBF_TRACE_NAME,
+					IUCV_DBF_TRACE_PAGES,
+					IUCV_DBF_TRACE_NR_AREAS,
+					IUCV_DBF_TRACE_LEN);
+
+	if ((iucv_dbf_setup == NULL) || (iucv_dbf_data == NULL) ||
+	    (iucv_dbf_trace == NULL)) {
+		iucv_unregister_dbf_views();
+		return -ENOMEM;
+	}
+	debug_register_view(iucv_dbf_setup, &debug_hex_ascii_view);
+	debug_set_level(iucv_dbf_setup, IUCV_DBF_SETUP_LEVEL);
+
+	debug_register_view(iucv_dbf_data, &debug_hex_ascii_view);
+	debug_set_level(iucv_dbf_data, IUCV_DBF_DATA_LEVEL);
+
+	debug_register_view(iucv_dbf_trace, &debug_hex_ascii_view);
+	debug_set_level(iucv_dbf_trace, IUCV_DBF_TRACE_LEVEL);
+
+	return 0;
+}
+
+/*
+ * Callback-wrappers, called from lowlevel iucv layer.
+ */
+
+static void netiucv_callback_rx(struct iucv_path *path,
+				struct iucv_message *msg)
+{
+	struct iucv_connection *conn = path->private;
+	struct iucv_event ev;
+
+	ev.conn = conn;
+	ev.data = msg;
+	fsm_event(conn->fsm, CONN_EVENT_RX, &ev);
+}
+
+static void netiucv_callback_txdone(struct iucv_path *path,
+				    struct iucv_message *msg)
+{
+	struct iucv_connection *conn = path->private;
+	struct iucv_event ev;
+
+	ev.conn = conn;
+	ev.data = msg;
+	fsm_event(conn->fsm, CONN_EVENT_TXDONE, &ev);
+}
+
+static void netiucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
+{
+	struct iucv_connection *conn = path->private;
+
+	fsm_event(conn->fsm, CONN_EVENT_CONN_ACK, conn);
+}
+
+static int netiucv_callback_connreq(struct iucv_path *path, u8 *ipvmid,
+				    u8 *ipuser)
+{
+	struct iucv_connection *conn = path->private;
+	struct iucv_event ev;
+	static char tmp_user[9];
+	static char tmp_udat[17];
+	int rc;
+
+	rc = -EINVAL;
+	memcpy(tmp_user, netiucv_printname(ipvmid, 8), 8);
+	memcpy(tmp_udat, ipuser, 16);
+	EBCASC(tmp_udat, 16);
+	read_lock_bh(&iucv_connection_rwlock);
+	list_for_each_entry(conn, &iucv_connection_list, list) {
+		if (strncmp(ipvmid, conn->userid, 8) ||
+		    strncmp(ipuser, conn->userdata, 16))
+			continue;
+		/* Found a matching connection for this path. */
+		conn->path = path;
+		ev.conn = conn;
+		ev.data = path;
+		fsm_event(conn->fsm, CONN_EVENT_CONN_REQ, &ev);
+		rc = 0;
+	}
+	IUCV_DBF_TEXT_(setup, 2, "Connection requested for %s.%s\n",
+		       tmp_user, netiucv_printname(tmp_udat, 16));
+	read_unlock_bh(&iucv_connection_rwlock);
+	return rc;
+}
+
+static void netiucv_callback_connrej(struct iucv_path *path, u8 *ipuser)
+{
+	struct iucv_connection *conn = path->private;
+
+	fsm_event(conn->fsm, CONN_EVENT_CONN_REJ, conn);
+}
+
+static void netiucv_callback_connsusp(struct iucv_path *path, u8 *ipuser)
+{
+	struct iucv_connection *conn = path->private;
+
+	fsm_event(conn->fsm, CONN_EVENT_CONN_SUS, conn);
+}
+
+static void netiucv_callback_connres(struct iucv_path *path, u8 *ipuser)
+{
+	struct iucv_connection *conn = path->private;
+
+	fsm_event(conn->fsm, CONN_EVENT_CONN_RES, conn);
+}
+
+/**
+ * NOP action for statemachines
+ */
+static void netiucv_action_nop(fsm_instance *fi, int event, void *arg)
+{
+}
+
+/*
+ * Actions of the connection statemachine
+ */
+
+/**
+ * netiucv_unpack_skb
+ * @conn: The connection where this skb has been received.
+ * @pskb: The received skb.
+ *
+ * Unpack a just received skb and hand it over to upper layers.
+ * Helper function for conn_action_rx.
+ */
+static void netiucv_unpack_skb(struct iucv_connection *conn,
+			       struct sk_buff *pskb)
+{
+	struct net_device     *dev = conn->netdev;
+	struct netiucv_priv   *privptr = netdev_priv(dev);
+	u16 offset = 0;
+
+	skb_put(pskb, NETIUCV_HDRLEN);
+	pskb->dev = dev;
+	pskb->ip_summed = CHECKSUM_NONE;
+	pskb->protocol = cpu_to_be16(ETH_P_IP);
+
+	while (1) {
+		struct sk_buff *skb;
+		struct ll_header *header = (struct ll_header *) pskb->data;
+
+		if (!header->next)
+			break;
+
+		skb_pull(pskb, NETIUCV_HDRLEN);
+		header->next -= offset;
+		offset += header->next;
+		header->next -= NETIUCV_HDRLEN;
+		if (skb_tailroom(pskb) < header->next) {
+			IUCV_DBF_TEXT_(data, 2, "Illegal next field: %d > %d\n",
+				header->next, skb_tailroom(pskb));
+			return;
+		}
+		skb_put(pskb, header->next);
+		skb_reset_mac_header(pskb);
+		skb = dev_alloc_skb(pskb->len);
+		if (!skb) {
+			IUCV_DBF_TEXT(data, 2,
+				"Out of memory in netiucv_unpack_skb\n");
+			privptr->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;
+		privptr->stats.rx_packets++;
+		privptr->stats.rx_bytes += skb->len;
+		/*
+		 * Since receiving is always initiated from a tasklet (in iucv.c),
+		 * we must use netif_rx_ni() instead of netif_rx()
+		 */
+		netif_rx_ni(skb);
+		skb_pull(pskb, header->next);
+		skb_put(pskb, NETIUCV_HDRLEN);
+	}
+}
+
+static void conn_action_rx(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_event *ev = arg;
+	struct iucv_connection *conn = ev->conn;
+	struct iucv_message *msg = ev->data;
+	struct netiucv_priv *privptr = netdev_priv(conn->netdev);
+	int rc;
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+
+	if (!conn->netdev) {
+		iucv_message_reject(conn->path, msg);
+		IUCV_DBF_TEXT(data, 2,
+			      "Received data for unlinked connection\n");
+		return;
+	}
+	if (msg->length > conn->max_buffsize) {
+		iucv_message_reject(conn->path, msg);
+		privptr->stats.rx_dropped++;
+		IUCV_DBF_TEXT_(data, 2, "msglen %d > max_buffsize %d\n",
+			       msg->length, conn->max_buffsize);
+		return;
+	}
+	conn->rx_buff->data = conn->rx_buff->head;
+	skb_reset_tail_pointer(conn->rx_buff);
+	conn->rx_buff->len = 0;
+	rc = iucv_message_receive(conn->path, msg, 0, conn->rx_buff->data,
+				  msg->length, NULL);
+	if (rc || msg->length < 5) {
+		privptr->stats.rx_errors++;
+		IUCV_DBF_TEXT_(data, 2, "rc %d from iucv_receive\n", rc);
+		return;
+	}
+	netiucv_unpack_skb(conn, conn->rx_buff);
+}
+
+static void conn_action_txdone(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_event *ev = arg;
+	struct iucv_connection *conn = ev->conn;
+	struct iucv_message *msg = ev->data;
+	struct iucv_message txmsg;
+	struct netiucv_priv *privptr = NULL;
+	u32 single_flag = msg->tag;
+	u32 txbytes = 0;
+	u32 txpackets = 0;
+	u32 stat_maxcq = 0;
+	struct sk_buff *skb;
+	unsigned long saveflags;
+	struct ll_header header;
+	int rc;
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+
+	if (!conn || !conn->netdev) {
+		IUCV_DBF_TEXT(data, 2,
+			      "Send confirmation for unlinked connection\n");
+		return;
+	}
+	privptr = netdev_priv(conn->netdev);
+	conn->prof.tx_pending--;
+	if (single_flag) {
+		if ((skb = skb_dequeue(&conn->commit_queue))) {
+			refcount_dec(&skb->users);
+			if (privptr) {
+				privptr->stats.tx_packets++;
+				privptr->stats.tx_bytes +=
+					(skb->len - NETIUCV_HDRLEN
+						  - NETIUCV_HDRLEN);
+			}
+			dev_kfree_skb_any(skb);
+		}
+	}
+	conn->tx_buff->data = conn->tx_buff->head;
+	skb_reset_tail_pointer(conn->tx_buff);
+	conn->tx_buff->len = 0;
+	spin_lock_irqsave(&conn->collect_lock, saveflags);
+	while ((skb = skb_dequeue(&conn->collect_queue))) {
+		header.next = conn->tx_buff->len + skb->len + NETIUCV_HDRLEN;
+		skb_put_data(conn->tx_buff, &header, NETIUCV_HDRLEN);
+		skb_copy_from_linear_data(skb,
+					  skb_put(conn->tx_buff, skb->len),
+					  skb->len);
+		txbytes += skb->len;
+		txpackets++;
+		stat_maxcq++;
+		refcount_dec(&skb->users);
+		dev_kfree_skb_any(skb);
+	}
+	if (conn->collect_len > conn->prof.maxmulti)
+		conn->prof.maxmulti = conn->collect_len;
+	conn->collect_len = 0;
+	spin_unlock_irqrestore(&conn->collect_lock, saveflags);
+	if (conn->tx_buff->len == 0) {
+		fsm_newstate(fi, CONN_STATE_IDLE);
+		return;
+	}
+
+	header.next = 0;
+	skb_put_data(conn->tx_buff, &header, NETIUCV_HDRLEN);
+	conn->prof.send_stamp = jiffies;
+	txmsg.class = 0;
+	txmsg.tag = 0;
+	rc = iucv_message_send(conn->path, &txmsg, 0, 0,
+			       conn->tx_buff->data, conn->tx_buff->len);
+	conn->prof.doios_multi++;
+	conn->prof.txlen += conn->tx_buff->len;
+	conn->prof.tx_pending++;
+	if (conn->prof.tx_pending > conn->prof.tx_max_pending)
+		conn->prof.tx_max_pending = conn->prof.tx_pending;
+	if (rc) {
+		conn->prof.tx_pending--;
+		fsm_newstate(fi, CONN_STATE_IDLE);
+		if (privptr)
+			privptr->stats.tx_errors += txpackets;
+		IUCV_DBF_TEXT_(data, 2, "rc %d from iucv_send\n", rc);
+	} else {
+		if (privptr) {
+			privptr->stats.tx_packets += txpackets;
+			privptr->stats.tx_bytes += txbytes;
+		}
+		if (stat_maxcq > conn->prof.maxcqueue)
+			conn->prof.maxcqueue = stat_maxcq;
+	}
+}
+
+static void conn_action_connaccept(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_event *ev = arg;
+	struct iucv_connection *conn = ev->conn;
+	struct iucv_path *path = ev->data;
+	struct net_device *netdev = conn->netdev;
+	struct netiucv_priv *privptr = netdev_priv(netdev);
+	int rc;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	conn->path = path;
+	path->msglim = NETIUCV_QUEUELEN_DEFAULT;
+	path->flags = 0;
+	rc = iucv_path_accept(path, &netiucv_handler, conn->userdata , conn);
+	if (rc) {
+		IUCV_DBF_TEXT_(setup, 2, "rc %d from iucv_accept", rc);
+		return;
+	}
+	fsm_newstate(fi, CONN_STATE_IDLE);
+	netdev->tx_queue_len = conn->path->msglim;
+	fsm_event(privptr->fsm, DEV_EVENT_CONUP, netdev);
+}
+
+static void conn_action_connreject(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_event *ev = arg;
+	struct iucv_path *path = ev->data;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	iucv_path_sever(path, NULL);
+}
+
+static void conn_action_connack(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_connection *conn = arg;
+	struct net_device *netdev = conn->netdev;
+	struct netiucv_priv *privptr = netdev_priv(netdev);
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	fsm_deltimer(&conn->timer);
+	fsm_newstate(fi, CONN_STATE_IDLE);
+	netdev->tx_queue_len = conn->path->msglim;
+	fsm_event(privptr->fsm, DEV_EVENT_CONUP, netdev);
+}
+
+static void conn_action_conntimsev(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_connection *conn = arg;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	fsm_deltimer(&conn->timer);
+	iucv_path_sever(conn->path, conn->userdata);
+	fsm_newstate(fi, CONN_STATE_STARTWAIT);
+}
+
+static void conn_action_connsever(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_connection *conn = arg;
+	struct net_device *netdev = conn->netdev;
+	struct netiucv_priv *privptr = netdev_priv(netdev);
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	fsm_deltimer(&conn->timer);
+	iucv_path_sever(conn->path, conn->userdata);
+	dev_info(privptr->dev, "The peer z/VM guest %s has closed the "
+			       "connection\n", netiucv_printuser(conn));
+	IUCV_DBF_TEXT(data, 2,
+		      "conn_action_connsever: Remote dropped connection\n");
+	fsm_newstate(fi, CONN_STATE_STARTWAIT);
+	fsm_event(privptr->fsm, DEV_EVENT_CONDOWN, netdev);
+}
+
+static void conn_action_start(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_connection *conn = arg;
+	struct net_device *netdev = conn->netdev;
+	struct netiucv_priv *privptr = netdev_priv(netdev);
+	int rc;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	fsm_newstate(fi, CONN_STATE_STARTWAIT);
+
+	/*
+	 * We must set the state before calling iucv_connect because the
+	 * callback handler could be called at any point after the connection
+	 * request is sent
+	 */
+
+	fsm_newstate(fi, CONN_STATE_SETUPWAIT);
+	conn->path = iucv_path_alloc(NETIUCV_QUEUELEN_DEFAULT, 0, GFP_KERNEL);
+	IUCV_DBF_TEXT_(setup, 2, "%s: connecting to %s ...\n",
+		netdev->name, netiucv_printuser(conn));
+
+	rc = iucv_path_connect(conn->path, &netiucv_handler, conn->userid,
+			       NULL, conn->userdata, conn);
+	switch (rc) {
+	case 0:
+		netdev->tx_queue_len = conn->path->msglim;
+		fsm_addtimer(&conn->timer, NETIUCV_TIMEOUT_5SEC,
+			     CONN_EVENT_TIMER, conn);
+		return;
+	case 11:
+		dev_warn(privptr->dev,
+			"The IUCV device failed to connect to z/VM guest %s\n",
+			netiucv_printname(conn->userid, 8));
+		fsm_newstate(fi, CONN_STATE_STARTWAIT);
+		break;
+	case 12:
+		dev_warn(privptr->dev,
+			"The IUCV device failed to connect to the peer on z/VM"
+			" guest %s\n", netiucv_printname(conn->userid, 8));
+		fsm_newstate(fi, CONN_STATE_STARTWAIT);
+		break;
+	case 13:
+		dev_err(privptr->dev,
+			"Connecting the IUCV device would exceed the maximum"
+			" number of IUCV connections\n");
+		fsm_newstate(fi, CONN_STATE_CONNERR);
+		break;
+	case 14:
+		dev_err(privptr->dev,
+			"z/VM guest %s has too many IUCV connections"
+			" to connect with the IUCV device\n",
+			netiucv_printname(conn->userid, 8));
+		fsm_newstate(fi, CONN_STATE_CONNERR);
+		break;
+	case 15:
+		dev_err(privptr->dev,
+			"The IUCV device cannot connect to a z/VM guest with no"
+			" IUCV authorization\n");
+		fsm_newstate(fi, CONN_STATE_CONNERR);
+		break;
+	default:
+		dev_err(privptr->dev,
+			"Connecting the IUCV device failed with error %d\n",
+			rc);
+		fsm_newstate(fi, CONN_STATE_CONNERR);
+		break;
+	}
+	IUCV_DBF_TEXT_(setup, 5, "iucv_connect rc is %d\n", rc);
+	kfree(conn->path);
+	conn->path = NULL;
+}
+
+static void netiucv_purge_skb_queue(struct sk_buff_head *q)
+{
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue(q))) {
+		refcount_dec(&skb->users);
+		dev_kfree_skb_any(skb);
+	}
+}
+
+static void conn_action_stop(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_event *ev = arg;
+	struct iucv_connection *conn = ev->conn;
+	struct net_device *netdev = conn->netdev;
+	struct netiucv_priv *privptr = netdev_priv(netdev);
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	fsm_deltimer(&conn->timer);
+	fsm_newstate(fi, CONN_STATE_STOPPED);
+	netiucv_purge_skb_queue(&conn->collect_queue);
+	if (conn->path) {
+		IUCV_DBF_TEXT(trace, 5, "calling iucv_path_sever\n");
+		iucv_path_sever(conn->path, conn->userdata);
+		kfree(conn->path);
+		conn->path = NULL;
+	}
+	netiucv_purge_skb_queue(&conn->commit_queue);
+	fsm_event(privptr->fsm, DEV_EVENT_CONDOWN, netdev);
+}
+
+static void conn_action_inval(fsm_instance *fi, int event, void *arg)
+{
+	struct iucv_connection *conn = arg;
+	struct net_device *netdev = conn->netdev;
+
+	IUCV_DBF_TEXT_(data, 2, "%s('%s'): conn_action_inval called\n",
+		netdev->name, conn->userid);
+}
+
+static const fsm_node conn_fsm[] = {
+	{ CONN_STATE_INVALID,   CONN_EVENT_START,    conn_action_inval      },
+	{ CONN_STATE_STOPPED,   CONN_EVENT_START,    conn_action_start      },
+
+	{ CONN_STATE_STOPPED,   CONN_EVENT_STOP,     conn_action_stop       },
+	{ CONN_STATE_STARTWAIT, CONN_EVENT_STOP,     conn_action_stop       },
+	{ CONN_STATE_SETUPWAIT, CONN_EVENT_STOP,     conn_action_stop       },
+	{ CONN_STATE_IDLE,      CONN_EVENT_STOP,     conn_action_stop       },
+	{ CONN_STATE_TX,        CONN_EVENT_STOP,     conn_action_stop       },
+	{ CONN_STATE_REGERR,    CONN_EVENT_STOP,     conn_action_stop       },
+	{ CONN_STATE_CONNERR,   CONN_EVENT_STOP,     conn_action_stop       },
+
+	{ CONN_STATE_STOPPED,   CONN_EVENT_CONN_REQ, conn_action_connreject },
+        { CONN_STATE_STARTWAIT, CONN_EVENT_CONN_REQ, conn_action_connaccept },
+	{ CONN_STATE_SETUPWAIT, CONN_EVENT_CONN_REQ, conn_action_connaccept },
+	{ CONN_STATE_IDLE,      CONN_EVENT_CONN_REQ, conn_action_connreject },
+	{ CONN_STATE_TX,        CONN_EVENT_CONN_REQ, conn_action_connreject },
+
+	{ CONN_STATE_SETUPWAIT, CONN_EVENT_CONN_ACK, conn_action_connack    },
+	{ CONN_STATE_SETUPWAIT, CONN_EVENT_TIMER,    conn_action_conntimsev },
+
+	{ CONN_STATE_SETUPWAIT, CONN_EVENT_CONN_REJ, conn_action_connsever  },
+	{ CONN_STATE_IDLE,      CONN_EVENT_CONN_REJ, conn_action_connsever  },
+	{ CONN_STATE_TX,        CONN_EVENT_CONN_REJ, conn_action_connsever  },
+
+	{ CONN_STATE_IDLE,      CONN_EVENT_RX,       conn_action_rx         },
+	{ CONN_STATE_TX,        CONN_EVENT_RX,       conn_action_rx         },
+
+	{ CONN_STATE_TX,        CONN_EVENT_TXDONE,   conn_action_txdone     },
+	{ CONN_STATE_IDLE,      CONN_EVENT_TXDONE,   conn_action_txdone     },
+};
+
+static const int CONN_FSM_LEN = sizeof(conn_fsm) / sizeof(fsm_node);
+
+
+/*
+ * Actions for interface - statemachine.
+ */
+
+/**
+ * dev_action_start
+ * @fi: An instance of an interface statemachine.
+ * @event: The event, just happened.
+ * @arg: Generic pointer, casted from struct net_device * upon call.
+ *
+ * Startup connection by sending CONN_EVENT_START to it.
+ */
+static void dev_action_start(fsm_instance *fi, int event, void *arg)
+{
+	struct net_device   *dev = arg;
+	struct netiucv_priv *privptr = netdev_priv(dev);
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	fsm_newstate(fi, DEV_STATE_STARTWAIT);
+	fsm_event(privptr->conn->fsm, CONN_EVENT_START, privptr->conn);
+}
+
+/**
+ * Shutdown connection by sending CONN_EVENT_STOP to it.
+ *
+ * @param fi    An instance of an interface statemachine.
+ * @param event The event, just happened.
+ * @param arg   Generic pointer, casted from struct net_device * upon call.
+ */
+static void
+dev_action_stop(fsm_instance *fi, int event, void *arg)
+{
+	struct net_device   *dev = arg;
+	struct netiucv_priv *privptr = netdev_priv(dev);
+	struct iucv_event   ev;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	ev.conn = privptr->conn;
+
+	fsm_newstate(fi, DEV_STATE_STOPWAIT);
+	fsm_event(privptr->conn->fsm, CONN_EVENT_STOP, &ev);
+}
+
+/**
+ * Called from connection statemachine
+ * when a connection is up and running.
+ *
+ * @param fi    An instance of an interface statemachine.
+ * @param event The event, just happened.
+ * @param arg   Generic pointer, casted from struct net_device * upon call.
+ */
+static void
+dev_action_connup(fsm_instance *fi, int event, void *arg)
+{
+	struct net_device   *dev = arg;
+	struct netiucv_priv *privptr = netdev_priv(dev);
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	switch (fsm_getstate(fi)) {
+		case DEV_STATE_STARTWAIT:
+			fsm_newstate(fi, DEV_STATE_RUNNING);
+			dev_info(privptr->dev,
+				"The IUCV device has been connected"
+				" successfully to %s\n",
+				netiucv_printuser(privptr->conn));
+			IUCV_DBF_TEXT(setup, 3,
+				"connection is up and running\n");
+			break;
+		case DEV_STATE_STOPWAIT:
+			IUCV_DBF_TEXT(data, 2,
+				"dev_action_connup: in DEV_STATE_STOPWAIT\n");
+			break;
+	}
+}
+
+/**
+ * Called from connection statemachine
+ * when a connection has been shutdown.
+ *
+ * @param fi    An instance of an interface statemachine.
+ * @param event The event, just happened.
+ * @param arg   Generic pointer, casted from struct net_device * upon call.
+ */
+static void
+dev_action_conndown(fsm_instance *fi, int event, void *arg)
+{
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	switch (fsm_getstate(fi)) {
+		case DEV_STATE_RUNNING:
+			fsm_newstate(fi, DEV_STATE_STARTWAIT);
+			break;
+		case DEV_STATE_STOPWAIT:
+			fsm_newstate(fi, DEV_STATE_STOPPED);
+			IUCV_DBF_TEXT(setup, 3, "connection is down\n");
+			break;
+	}
+}
+
+static const fsm_node dev_fsm[] = {
+	{ DEV_STATE_STOPPED,    DEV_EVENT_START,   dev_action_start    },
+
+	{ DEV_STATE_STOPWAIT,   DEV_EVENT_START,   dev_action_start    },
+	{ DEV_STATE_STOPWAIT,   DEV_EVENT_CONDOWN, dev_action_conndown },
+
+	{ DEV_STATE_STARTWAIT,  DEV_EVENT_STOP,    dev_action_stop     },
+	{ DEV_STATE_STARTWAIT,  DEV_EVENT_CONUP,   dev_action_connup   },
+
+	{ DEV_STATE_RUNNING,    DEV_EVENT_STOP,    dev_action_stop     },
+	{ DEV_STATE_RUNNING,    DEV_EVENT_CONDOWN, dev_action_conndown },
+	{ DEV_STATE_RUNNING,    DEV_EVENT_CONUP,   netiucv_action_nop  },
+};
+
+static const int DEV_FSM_LEN = sizeof(dev_fsm) / sizeof(fsm_node);
+
+/**
+ * Transmit a packet.
+ * This is a helper function for netiucv_tx().
+ *
+ * @param conn Connection to be used for sending.
+ * @param skb Pointer to struct sk_buff of packet to send.
+ *            The linklevel header has already been set up
+ *            by netiucv_tx().
+ *
+ * @return 0 on success, -ERRNO on failure. (Never fails.)
+ */
+static int netiucv_transmit_skb(struct iucv_connection *conn,
+				struct sk_buff *skb)
+{
+	struct iucv_message msg;
+	unsigned long saveflags;
+	struct ll_header header;
+	int rc;
+
+	if (fsm_getstate(conn->fsm) != CONN_STATE_IDLE) {
+		int l = skb->len + NETIUCV_HDRLEN;
+
+		spin_lock_irqsave(&conn->collect_lock, saveflags);
+		if (conn->collect_len + l >
+		    (conn->max_buffsize - NETIUCV_HDRLEN)) {
+			rc = -EBUSY;
+			IUCV_DBF_TEXT(data, 2,
+				      "EBUSY from netiucv_transmit_skb\n");
+		} else {
+			refcount_inc(&skb->users);
+			skb_queue_tail(&conn->collect_queue, skb);
+			conn->collect_len += l;
+			rc = 0;
+		}
+		spin_unlock_irqrestore(&conn->collect_lock, saveflags);
+	} else {
+		struct sk_buff *nskb = skb;
+		/**
+		 * Copy the skb to a new allocated skb in lowmem only if the
+		 * data is located above 2G in memory or tailroom is < 2.
+		 */
+		unsigned long hi = ((unsigned long)(skb_tail_pointer(skb) +
+				    NETIUCV_HDRLEN)) >> 31;
+		int copied = 0;
+		if (hi || (skb_tailroom(skb) < 2)) {
+			nskb = alloc_skb(skb->len + NETIUCV_HDRLEN +
+					 NETIUCV_HDRLEN, GFP_ATOMIC | GFP_DMA);
+			if (!nskb) {
+				IUCV_DBF_TEXT(data, 2, "alloc_skb failed\n");
+				rc = -ENOMEM;
+				return rc;
+			} else {
+				skb_reserve(nskb, NETIUCV_HDRLEN);
+				skb_put_data(nskb, skb->data, skb->len);
+			}
+			copied = 1;
+		}
+		/**
+		 * skb now is below 2G and has enough room. Add headers.
+		 */
+		header.next = nskb->len + NETIUCV_HDRLEN;
+		memcpy(skb_push(nskb, NETIUCV_HDRLEN), &header, NETIUCV_HDRLEN);
+		header.next = 0;
+		skb_put_data(nskb, &header, NETIUCV_HDRLEN);
+
+		fsm_newstate(conn->fsm, CONN_STATE_TX);
+		conn->prof.send_stamp = jiffies;
+
+		msg.tag = 1;
+		msg.class = 0;
+		rc = iucv_message_send(conn->path, &msg, 0, 0,
+				       nskb->data, nskb->len);
+		conn->prof.doios_single++;
+		conn->prof.txlen += skb->len;
+		conn->prof.tx_pending++;
+		if (conn->prof.tx_pending > conn->prof.tx_max_pending)
+			conn->prof.tx_max_pending = conn->prof.tx_pending;
+		if (rc) {
+			struct netiucv_priv *privptr;
+			fsm_newstate(conn->fsm, CONN_STATE_IDLE);
+			conn->prof.tx_pending--;
+			privptr = netdev_priv(conn->netdev);
+			if (privptr)
+				privptr->stats.tx_errors++;
+			if (copied)
+				dev_kfree_skb(nskb);
+			else {
+				/**
+				 * Remove our headers. They get added
+				 * again on retransmit.
+				 */
+				skb_pull(skb, NETIUCV_HDRLEN);
+				skb_trim(skb, skb->len - NETIUCV_HDRLEN);
+			}
+			IUCV_DBF_TEXT_(data, 2, "rc %d from iucv_send\n", rc);
+		} else {
+			if (copied)
+				dev_kfree_skb(skb);
+			refcount_inc(&nskb->users);
+			skb_queue_tail(&conn->commit_queue, nskb);
+		}
+	}
+
+	return rc;
+}
+
+/*
+ * Interface API for upper network layers
+ */
+
+/**
+ * Open an interface.
+ * Called from generic network layer when ifconfig up is run.
+ *
+ * @param dev Pointer to interface struct.
+ *
+ * @return 0 on success, -ERRNO on failure. (Never fails.)
+ */
+static int netiucv_open(struct net_device *dev)
+{
+	struct netiucv_priv *priv = netdev_priv(dev);
+
+	fsm_event(priv->fsm, DEV_EVENT_START, dev);
+	return 0;
+}
+
+/**
+ * Close an interface.
+ * Called from generic network layer when ifconfig down is run.
+ *
+ * @param dev Pointer to interface struct.
+ *
+ * @return 0 on success, -ERRNO on failure. (Never fails.)
+ */
+static int netiucv_close(struct net_device *dev)
+{
+	struct netiucv_priv *priv = netdev_priv(dev);
+
+	fsm_event(priv->fsm, DEV_EVENT_STOP, dev);
+	return 0;
+}
+
+static int netiucv_pm_prepare(struct device *dev)
+{
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	return 0;
+}
+
+static void netiucv_pm_complete(struct device *dev)
+{
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	return;
+}
+
+/**
+ * netiucv_pm_freeze() - Freeze PM callback
+ * @dev:	netiucv device
+ *
+ * close open netiucv interfaces
+ */
+static int netiucv_pm_freeze(struct device *dev)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+	struct net_device *ndev = NULL;
+	int rc = 0;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	if (priv && priv->conn)
+		ndev = priv->conn->netdev;
+	if (!ndev)
+		goto out;
+	netif_device_detach(ndev);
+	priv->pm_state = fsm_getstate(priv->fsm);
+	rc = netiucv_close(ndev);
+out:
+	return rc;
+}
+
+/**
+ * netiucv_pm_restore_thaw() - Thaw and restore PM callback
+ * @dev:	netiucv device
+ *
+ * re-open netiucv interfaces closed during freeze
+ */
+static int netiucv_pm_restore_thaw(struct device *dev)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+	struct net_device *ndev = NULL;
+	int rc = 0;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	if (priv && priv->conn)
+		ndev = priv->conn->netdev;
+	if (!ndev)
+		goto out;
+	switch (priv->pm_state) {
+	case DEV_STATE_RUNNING:
+	case DEV_STATE_STARTWAIT:
+		rc = netiucv_open(ndev);
+		break;
+	default:
+		break;
+	}
+	netif_device_attach(ndev);
+out:
+	return rc;
+}
+
+/**
+ * Start transmission of a packet.
+ * Called from generic network device layer.
+ *
+ * @param skb Pointer to buffer containing the packet.
+ * @param dev Pointer to interface struct.
+ *
+ * @return 0 if packet consumed, !0 if packet rejected.
+ *         Note: If we return !0, then the packet is free'd by
+ *               the generic network layer.
+ */
+static int netiucv_tx(struct sk_buff *skb, struct net_device *dev)
+{
+	struct netiucv_priv *privptr = netdev_priv(dev);
+	int rc;
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+	/**
+	 * Some sanity checks ...
+	 */
+	if (skb == NULL) {
+		IUCV_DBF_TEXT(data, 2, "netiucv_tx: skb is NULL\n");
+		privptr->stats.tx_dropped++;
+		return NETDEV_TX_OK;
+	}
+	if (skb_headroom(skb) < NETIUCV_HDRLEN) {
+		IUCV_DBF_TEXT(data, 2,
+			"netiucv_tx: skb_headroom < NETIUCV_HDRLEN\n");
+		dev_kfree_skb(skb);
+		privptr->stats.tx_dropped++;
+		return NETDEV_TX_OK;
+	}
+
+	/**
+	 * If connection is not running, try to restart it
+	 * and throw away packet.
+	 */
+	if (fsm_getstate(privptr->fsm) != DEV_STATE_RUNNING) {
+		dev_kfree_skb(skb);
+		privptr->stats.tx_dropped++;
+		privptr->stats.tx_errors++;
+		privptr->stats.tx_carrier_errors++;
+		return NETDEV_TX_OK;
+	}
+
+	if (netiucv_test_and_set_busy(dev)) {
+		IUCV_DBF_TEXT(data, 2, "EBUSY from netiucv_tx\n");
+		return NETDEV_TX_BUSY;
+	}
+	netif_trans_update(dev);
+	rc = netiucv_transmit_skb(privptr->conn, skb);
+	netiucv_clear_busy(dev);
+	return rc ? NETDEV_TX_BUSY : NETDEV_TX_OK;
+}
+
+/**
+ * netiucv_stats
+ * @dev: Pointer to interface struct.
+ *
+ * Returns interface statistics of a device.
+ *
+ * Returns pointer to stats struct of this interface.
+ */
+static struct net_device_stats *netiucv_stats (struct net_device * dev)
+{
+	struct netiucv_priv *priv = netdev_priv(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return &priv->stats;
+}
+
+/*
+ * attributes in sysfs
+ */
+
+static ssize_t user_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%s\n", netiucv_printuser(priv->conn));
+}
+
+static int netiucv_check_user(const char *buf, size_t count, char *username,
+			      char *userdata)
+{
+	const char *p;
+	int i;
+
+	p = strchr(buf, '.');
+	if ((p && ((count > 26) ||
+		   ((p - buf) > 8) ||
+		   (buf + count - p > 18))) ||
+	    (!p && (count > 9))) {
+		IUCV_DBF_TEXT(setup, 2, "conn_write: too long\n");
+		return -EINVAL;
+	}
+
+	for (i = 0, p = buf; i < 8 && *p && *p != '.'; i++, p++) {
+		if (isalnum(*p) || *p == '$') {
+			username[i] = toupper(*p);
+			continue;
+		}
+		if (*p == '\n')
+			/* trailing lf, grr */
+			break;
+		IUCV_DBF_TEXT_(setup, 2,
+			       "conn_write: invalid character %02x\n", *p);
+		return -EINVAL;
+	}
+	while (i < 8)
+		username[i++] = ' ';
+	username[8] = '\0';
+
+	if (*p == '.') {
+		p++;
+		for (i = 0; i < 16 && *p; i++, p++) {
+			if (*p == '\n')
+				break;
+			userdata[i] = toupper(*p);
+		}
+		while (i > 0 && i < 16)
+			userdata[i++] = ' ';
+	} else
+		memcpy(userdata, iucvMagic_ascii, 16);
+	userdata[16] = '\0';
+	ASCEBC(userdata, 16);
+
+	return 0;
+}
+
+static ssize_t user_write(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+	struct net_device *ndev = priv->conn->netdev;
+	char	username[9];
+	char	userdata[17];
+	int	rc;
+	struct iucv_connection *cp;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	rc = netiucv_check_user(buf, count, username, userdata);
+	if (rc)
+		return rc;
+
+	if (memcmp(username, priv->conn->userid, 9) &&
+	    (ndev->flags & (IFF_UP | IFF_RUNNING))) {
+		/* username changed while the interface is active. */
+		IUCV_DBF_TEXT(setup, 2, "user_write: device active\n");
+		return -EPERM;
+	}
+	read_lock_bh(&iucv_connection_rwlock);
+	list_for_each_entry(cp, &iucv_connection_list, list) {
+		if (!strncmp(username, cp->userid, 9) &&
+		   !strncmp(userdata, cp->userdata, 17) && cp->netdev != ndev) {
+			read_unlock_bh(&iucv_connection_rwlock);
+			IUCV_DBF_TEXT_(setup, 2, "user_write: Connection to %s "
+				"already exists\n", netiucv_printuser(cp));
+			return -EEXIST;
+		}
+	}
+	read_unlock_bh(&iucv_connection_rwlock);
+	memcpy(priv->conn->userid, username, 9);
+	memcpy(priv->conn->userdata, userdata, 17);
+	return count;
+}
+
+static DEVICE_ATTR(user, 0644, user_show, user_write);
+
+static ssize_t buffer_show (struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%d\n", priv->conn->max_buffsize);
+}
+
+static ssize_t buffer_write (struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+	struct net_device *ndev = priv->conn->netdev;
+	unsigned int bs1;
+	int rc;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	if (count >= 39)
+		return -EINVAL;
+
+	rc = kstrtouint(buf, 0, &bs1);
+
+	if (rc == -EINVAL) {
+		IUCV_DBF_TEXT_(setup, 2, "buffer_write: invalid char %s\n",
+			buf);
+		return -EINVAL;
+	}
+	if ((rc == -ERANGE) || (bs1 > NETIUCV_BUFSIZE_MAX)) {
+		IUCV_DBF_TEXT_(setup, 2,
+			"buffer_write: buffer size %d too large\n",
+			bs1);
+		return -EINVAL;
+	}
+	if ((ndev->flags & IFF_RUNNING) &&
+	    (bs1 < (ndev->mtu + NETIUCV_HDRLEN + 2))) {
+		IUCV_DBF_TEXT_(setup, 2,
+			"buffer_write: buffer size %d too small\n",
+			bs1);
+		return -EINVAL;
+	}
+	if (bs1 < (576 + NETIUCV_HDRLEN + NETIUCV_HDRLEN)) {
+		IUCV_DBF_TEXT_(setup, 2,
+			"buffer_write: buffer size %d too small\n",
+			bs1);
+		return -EINVAL;
+	}
+
+	priv->conn->max_buffsize = bs1;
+	if (!(ndev->flags & IFF_RUNNING))
+		ndev->mtu = bs1 - NETIUCV_HDRLEN - NETIUCV_HDRLEN;
+
+	return count;
+
+}
+
+static DEVICE_ATTR(buffer, 0644, buffer_show, buffer_write);
+
+static ssize_t dev_fsm_show (struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%s\n", fsm_getstate_str(priv->fsm));
+}
+
+static DEVICE_ATTR(device_fsm_state, 0444, dev_fsm_show, NULL);
+
+static ssize_t conn_fsm_show (struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%s\n", fsm_getstate_str(priv->conn->fsm));
+}
+
+static DEVICE_ATTR(connection_fsm_state, 0444, conn_fsm_show, NULL);
+
+static ssize_t maxmulti_show (struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%ld\n", priv->conn->prof.maxmulti);
+}
+
+static ssize_t maxmulti_write (struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+	priv->conn->prof.maxmulti = 0;
+	return count;
+}
+
+static DEVICE_ATTR(max_tx_buffer_used, 0644, maxmulti_show, maxmulti_write);
+
+static ssize_t maxcq_show (struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%ld\n", priv->conn->prof.maxcqueue);
+}
+
+static ssize_t maxcq_write (struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+	priv->conn->prof.maxcqueue = 0;
+	return count;
+}
+
+static DEVICE_ATTR(max_chained_skbs, 0644, maxcq_show, maxcq_write);
+
+static ssize_t sdoio_show (struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%ld\n", priv->conn->prof.doios_single);
+}
+
+static ssize_t sdoio_write (struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+	priv->conn->prof.doios_single = 0;
+	return count;
+}
+
+static DEVICE_ATTR(tx_single_write_ops, 0644, sdoio_show, sdoio_write);
+
+static ssize_t mdoio_show (struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%ld\n", priv->conn->prof.doios_multi);
+}
+
+static ssize_t mdoio_write (struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	priv->conn->prof.doios_multi = 0;
+	return count;
+}
+
+static DEVICE_ATTR(tx_multi_write_ops, 0644, mdoio_show, mdoio_write);
+
+static ssize_t txlen_show (struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%ld\n", priv->conn->prof.txlen);
+}
+
+static ssize_t txlen_write (struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+	priv->conn->prof.txlen = 0;
+	return count;
+}
+
+static DEVICE_ATTR(netto_bytes, 0644, txlen_show, txlen_write);
+
+static ssize_t txtime_show (struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%ld\n", priv->conn->prof.tx_time);
+}
+
+static ssize_t txtime_write (struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+	priv->conn->prof.tx_time = 0;
+	return count;
+}
+
+static DEVICE_ATTR(max_tx_io_time, 0644, txtime_show, txtime_write);
+
+static ssize_t txpend_show (struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%ld\n", priv->conn->prof.tx_pending);
+}
+
+static ssize_t txpend_write (struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+	priv->conn->prof.tx_pending = 0;
+	return count;
+}
+
+static DEVICE_ATTR(tx_pending, 0644, txpend_show, txpend_write);
+
+static ssize_t txmpnd_show (struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 5, __func__);
+	return sprintf(buf, "%ld\n", priv->conn->prof.tx_max_pending);
+}
+
+static ssize_t txmpnd_write (struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct netiucv_priv *priv = dev_get_drvdata(dev);
+
+	IUCV_DBF_TEXT(trace, 4, __func__);
+	priv->conn->prof.tx_max_pending = 0;
+	return count;
+}
+
+static DEVICE_ATTR(tx_max_pending, 0644, txmpnd_show, txmpnd_write);
+
+static struct attribute *netiucv_attrs[] = {
+	&dev_attr_buffer.attr,
+	&dev_attr_user.attr,
+	NULL,
+};
+
+static struct attribute_group netiucv_attr_group = {
+	.attrs = netiucv_attrs,
+};
+
+static struct attribute *netiucv_stat_attrs[] = {
+	&dev_attr_device_fsm_state.attr,
+	&dev_attr_connection_fsm_state.attr,
+	&dev_attr_max_tx_buffer_used.attr,
+	&dev_attr_max_chained_skbs.attr,
+	&dev_attr_tx_single_write_ops.attr,
+	&dev_attr_tx_multi_write_ops.attr,
+	&dev_attr_netto_bytes.attr,
+	&dev_attr_max_tx_io_time.attr,
+	&dev_attr_tx_pending.attr,
+	&dev_attr_tx_max_pending.attr,
+	NULL,
+};
+
+static struct attribute_group netiucv_stat_attr_group = {
+	.name  = "stats",
+	.attrs = netiucv_stat_attrs,
+};
+
+static const struct attribute_group *netiucv_attr_groups[] = {
+	&netiucv_stat_attr_group,
+	&netiucv_attr_group,
+	NULL,
+};
+
+static int netiucv_register_device(struct net_device *ndev)
+{
+	struct netiucv_priv *priv = netdev_priv(ndev);
+	struct device *dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+	int ret;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	if (dev) {
+		dev_set_name(dev, "net%s", ndev->name);
+		dev->bus = &iucv_bus;
+		dev->parent = iucv_root;
+		dev->groups = netiucv_attr_groups;
+		/*
+		 * The release function could be called after the
+		 * module has been unloaded. It's _only_ task is to
+		 * free the struct. Therefore, we specify kfree()
+		 * directly here. (Probably a little bit obfuscating
+		 * but legitime ...).
+		 */
+		dev->release = (void (*)(struct device *))kfree;
+		dev->driver = &netiucv_driver;
+	} else
+		return -ENOMEM;
+
+	ret = device_register(dev);
+	if (ret) {
+		put_device(dev);
+		return ret;
+	}
+	priv->dev = dev;
+	dev_set_drvdata(dev, priv);
+	return 0;
+}
+
+static void netiucv_unregister_device(struct device *dev)
+{
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	device_unregister(dev);
+}
+
+/**
+ * Allocate and initialize a new connection structure.
+ * Add it to the list of netiucv connections;
+ */
+static struct iucv_connection *netiucv_new_connection(struct net_device *dev,
+						      char *username,
+						      char *userdata)
+{
+	struct iucv_connection *conn;
+
+	conn = kzalloc(sizeof(*conn), GFP_KERNEL);
+	if (!conn)
+		goto out;
+	skb_queue_head_init(&conn->collect_queue);
+	skb_queue_head_init(&conn->commit_queue);
+	spin_lock_init(&conn->collect_lock);
+	conn->max_buffsize = NETIUCV_BUFSIZE_DEFAULT;
+	conn->netdev = dev;
+
+	conn->rx_buff = alloc_skb(conn->max_buffsize, GFP_KERNEL | GFP_DMA);
+	if (!conn->rx_buff)
+		goto out_conn;
+	conn->tx_buff = alloc_skb(conn->max_buffsize, GFP_KERNEL | GFP_DMA);
+	if (!conn->tx_buff)
+		goto out_rx;
+	conn->fsm = init_fsm("netiucvconn", conn_state_names,
+			     conn_event_names, NR_CONN_STATES,
+			     NR_CONN_EVENTS, conn_fsm, CONN_FSM_LEN,
+			     GFP_KERNEL);
+	if (!conn->fsm)
+		goto out_tx;
+
+	fsm_settimer(conn->fsm, &conn->timer);
+	fsm_newstate(conn->fsm, CONN_STATE_INVALID);
+
+	if (userdata)
+		memcpy(conn->userdata, userdata, 17);
+	if (username) {
+		memcpy(conn->userid, username, 9);
+		fsm_newstate(conn->fsm, CONN_STATE_STOPPED);
+	}
+
+	write_lock_bh(&iucv_connection_rwlock);
+	list_add_tail(&conn->list, &iucv_connection_list);
+	write_unlock_bh(&iucv_connection_rwlock);
+	return conn;
+
+out_tx:
+	kfree_skb(conn->tx_buff);
+out_rx:
+	kfree_skb(conn->rx_buff);
+out_conn:
+	kfree(conn);
+out:
+	return NULL;
+}
+
+/**
+ * Release a connection structure and remove it from the
+ * list of netiucv connections.
+ */
+static void netiucv_remove_connection(struct iucv_connection *conn)
+{
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	write_lock_bh(&iucv_connection_rwlock);
+	list_del_init(&conn->list);
+	write_unlock_bh(&iucv_connection_rwlock);
+	fsm_deltimer(&conn->timer);
+	netiucv_purge_skb_queue(&conn->collect_queue);
+	if (conn->path) {
+		iucv_path_sever(conn->path, conn->userdata);
+		kfree(conn->path);
+		conn->path = NULL;
+	}
+	netiucv_purge_skb_queue(&conn->commit_queue);
+	kfree_fsm(conn->fsm);
+	kfree_skb(conn->rx_buff);
+	kfree_skb(conn->tx_buff);
+}
+
+/**
+ * Release everything of a net device.
+ */
+static void netiucv_free_netdevice(struct net_device *dev)
+{
+	struct netiucv_priv *privptr = netdev_priv(dev);
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+	if (!dev)
+		return;
+
+	if (privptr) {
+		if (privptr->conn)
+			netiucv_remove_connection(privptr->conn);
+		if (privptr->fsm)
+			kfree_fsm(privptr->fsm);
+		privptr->conn = NULL; privptr->fsm = NULL;
+		/* privptr gets freed by free_netdev() */
+	}
+}
+
+/**
+ * Initialize a net device. (Called from kernel in alloc_netdev())
+ */
+static const struct net_device_ops netiucv_netdev_ops = {
+	.ndo_open		= netiucv_open,
+	.ndo_stop		= netiucv_close,
+	.ndo_get_stats		= netiucv_stats,
+	.ndo_start_xmit		= netiucv_tx,
+};
+
+static void netiucv_setup_netdevice(struct net_device *dev)
+{
+	dev->mtu	         = NETIUCV_MTU_DEFAULT;
+	dev->min_mtu		 = 576;
+	dev->max_mtu		 = NETIUCV_MTU_MAX;
+	dev->needs_free_netdev   = true;
+	dev->priv_destructor     = netiucv_free_netdevice;
+	dev->hard_header_len     = NETIUCV_HDRLEN;
+	dev->addr_len            = 0;
+	dev->type                = ARPHRD_SLIP;
+	dev->tx_queue_len        = NETIUCV_QUEUELEN_DEFAULT;
+	dev->flags	         = IFF_POINTOPOINT | IFF_NOARP;
+	dev->netdev_ops		 = &netiucv_netdev_ops;
+}
+
+/**
+ * Allocate and initialize everything of a net device.
+ */
+static struct net_device *netiucv_init_netdevice(char *username, char *userdata)
+{
+	struct netiucv_priv *privptr;
+	struct net_device *dev;
+
+	dev = alloc_netdev(sizeof(struct netiucv_priv), "iucv%d",
+			   NET_NAME_UNKNOWN, netiucv_setup_netdevice);
+	if (!dev)
+		return NULL;
+	rtnl_lock();
+	if (dev_alloc_name(dev, dev->name) < 0)
+		goto out_netdev;
+
+	privptr = netdev_priv(dev);
+	privptr->fsm = init_fsm("netiucvdev", dev_state_names,
+				dev_event_names, NR_DEV_STATES, NR_DEV_EVENTS,
+				dev_fsm, DEV_FSM_LEN, GFP_KERNEL);
+	if (!privptr->fsm)
+		goto out_netdev;
+
+	privptr->conn = netiucv_new_connection(dev, username, userdata);
+	if (!privptr->conn) {
+		IUCV_DBF_TEXT(setup, 2, "NULL from netiucv_new_connection\n");
+		goto out_fsm;
+	}
+	fsm_newstate(privptr->fsm, DEV_STATE_STOPPED);
+	return dev;
+
+out_fsm:
+	kfree_fsm(privptr->fsm);
+out_netdev:
+	rtnl_unlock();
+	free_netdev(dev);
+	return NULL;
+}
+
+static ssize_t connection_store(struct device_driver *drv, const char *buf,
+				size_t count)
+{
+	char username[9];
+	char userdata[17];
+	int rc;
+	struct net_device *dev;
+	struct netiucv_priv *priv;
+	struct iucv_connection *cp;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	rc = netiucv_check_user(buf, count, username, userdata);
+	if (rc)
+		return rc;
+
+	read_lock_bh(&iucv_connection_rwlock);
+	list_for_each_entry(cp, &iucv_connection_list, list) {
+		if (!strncmp(username, cp->userid, 9) &&
+		    !strncmp(userdata, cp->userdata, 17)) {
+			read_unlock_bh(&iucv_connection_rwlock);
+			IUCV_DBF_TEXT_(setup, 2, "conn_write: Connection to %s "
+				"already exists\n", netiucv_printuser(cp));
+			return -EEXIST;
+		}
+	}
+	read_unlock_bh(&iucv_connection_rwlock);
+
+	dev = netiucv_init_netdevice(username, userdata);
+	if (!dev) {
+		IUCV_DBF_TEXT(setup, 2, "NULL from netiucv_init_netdevice\n");
+		return -ENODEV;
+	}
+
+	rc = netiucv_register_device(dev);
+	if (rc) {
+		rtnl_unlock();
+		IUCV_DBF_TEXT_(setup, 2,
+			"ret %d from netiucv_register_device\n", rc);
+		goto out_free_ndev;
+	}
+
+	/* sysfs magic */
+	priv = netdev_priv(dev);
+	SET_NETDEV_DEV(dev, priv->dev);
+
+	rc = register_netdevice(dev);
+	rtnl_unlock();
+	if (rc)
+		goto out_unreg;
+
+	dev_info(priv->dev, "The IUCV interface to %s has been established "
+			    "successfully\n",
+		netiucv_printuser(priv->conn));
+
+	return count;
+
+out_unreg:
+	netiucv_unregister_device(priv->dev);
+out_free_ndev:
+	netiucv_free_netdevice(dev);
+	return rc;
+}
+static DRIVER_ATTR_WO(connection);
+
+static ssize_t remove_store(struct device_driver *drv, const char *buf,
+			    size_t count)
+{
+	struct iucv_connection *cp;
+        struct net_device *ndev;
+        struct netiucv_priv *priv;
+        struct device *dev;
+        char name[IFNAMSIZ];
+	const char *p;
+        int i;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+
+        if (count >= IFNAMSIZ)
+                count = IFNAMSIZ - 1;
+
+	for (i = 0, p = buf; i < count && *p; i++, p++) {
+		if (*p == '\n' || *p == ' ')
+                        /* trailing lf, grr */
+                        break;
+		name[i] = *p;
+        }
+        name[i] = '\0';
+
+	read_lock_bh(&iucv_connection_rwlock);
+	list_for_each_entry(cp, &iucv_connection_list, list) {
+		ndev = cp->netdev;
+		priv = netdev_priv(ndev);
+                dev = priv->dev;
+		if (strncmp(name, ndev->name, count))
+			continue;
+		read_unlock_bh(&iucv_connection_rwlock);
+                if (ndev->flags & (IFF_UP | IFF_RUNNING)) {
+			dev_warn(dev, "The IUCV device is connected"
+				" to %s and cannot be removed\n",
+				priv->conn->userid);
+			IUCV_DBF_TEXT(data, 2, "remove_write: still active\n");
+			return -EPERM;
+                }
+                unregister_netdev(ndev);
+                netiucv_unregister_device(dev);
+                return count;
+        }
+	read_unlock_bh(&iucv_connection_rwlock);
+	IUCV_DBF_TEXT(data, 2, "remove_write: unknown device\n");
+        return -EINVAL;
+}
+static DRIVER_ATTR_WO(remove);
+
+static struct attribute * netiucv_drv_attrs[] = {
+	&driver_attr_connection.attr,
+	&driver_attr_remove.attr,
+	NULL,
+};
+
+static struct attribute_group netiucv_drv_attr_group = {
+	.attrs = netiucv_drv_attrs,
+};
+
+static const struct attribute_group *netiucv_drv_attr_groups[] = {
+	&netiucv_drv_attr_group,
+	NULL,
+};
+
+static void netiucv_banner(void)
+{
+	pr_info("driver initialized\n");
+}
+
+static void __exit netiucv_exit(void)
+{
+	struct iucv_connection *cp;
+	struct net_device *ndev;
+	struct netiucv_priv *priv;
+	struct device *dev;
+
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	while (!list_empty(&iucv_connection_list)) {
+		cp = list_entry(iucv_connection_list.next,
+				struct iucv_connection, list);
+		ndev = cp->netdev;
+		priv = netdev_priv(ndev);
+		dev = priv->dev;
+
+		unregister_netdev(ndev);
+		netiucv_unregister_device(dev);
+	}
+
+	device_unregister(netiucv_dev);
+	driver_unregister(&netiucv_driver);
+	iucv_unregister(&netiucv_handler, 1);
+	iucv_unregister_dbf_views();
+
+	pr_info("driver unloaded\n");
+	return;
+}
+
+static int __init netiucv_init(void)
+{
+	int rc;
+
+	rc = iucv_register_dbf_views();
+	if (rc)
+		goto out;
+	rc = iucv_register(&netiucv_handler, 1);
+	if (rc)
+		goto out_dbf;
+	IUCV_DBF_TEXT(trace, 3, __func__);
+	netiucv_driver.groups = netiucv_drv_attr_groups;
+	rc = driver_register(&netiucv_driver);
+	if (rc) {
+		IUCV_DBF_TEXT_(setup, 2, "ret %d from driver_register\n", rc);
+		goto out_iucv;
+	}
+	/* establish dummy device */
+	netiucv_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+	if (!netiucv_dev) {
+		rc = -ENOMEM;
+		goto out_driver;
+	}
+	dev_set_name(netiucv_dev, "netiucv");
+	netiucv_dev->bus = &iucv_bus;
+	netiucv_dev->parent = iucv_root;
+	netiucv_dev->release = (void (*)(struct device *))kfree;
+	netiucv_dev->driver = &netiucv_driver;
+	rc = device_register(netiucv_dev);
+	if (rc) {
+		put_device(netiucv_dev);
+		goto out_driver;
+	}
+	netiucv_banner();
+	return rc;
+
+out_driver:
+	driver_unregister(&netiucv_driver);
+out_iucv:
+	iucv_unregister(&netiucv_handler, 1);
+out_dbf:
+	iucv_unregister_dbf_views();
+out:
+	return rc;
+}
+
+module_init(netiucv_init);
+module_exit(netiucv_exit);
+MODULE_LICENSE("GPL");