ctcm: infrastructure for replaced ctc driver

ctcm driver supports the channel-to-channel connections of the
old ctc driver plus an additional MPC protocol to provide SNA
connectivity.

This new ctcm driver replaces the existing ctc driver.

Signed-off-by: Peter Tiedemann <ptiedem@de.ibm.com>
Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

11 files changed, 7920 insertions, 8 deletions

diff --git a/drivers/s390/net/Kconfig b/drivers/s390/net/Kconfig
index 9ef029e9c838..773f5a6d5822 100644
--- a/drivers/s390/net/Kconfig
+++ b/drivers/s390/net/Kconfig
@@ -11,15 +11,17 @@ config LCS
 	   To compile as a module, choose M. The module name is lcs.ko.
 	   If you do not know what it is, it's safe to choose Y.
 
-config CTC
-	tristate "CTC device support"
+config CTCM
+	tristate "CTC and MPC SNA device support"
 	depends on CCW && NETDEVICES
 	help
 	  Select this option if you want to use channel-to-channel
 	  point-to-point networking on IBM System z.
 	  This device driver supports real CTC coupling using ESCON.
 	  It also supports virtual CTCs when running under VM.
-	  To compile as a module, choose M. The module name is ctc.ko.
+	  This driver also supports channel-to-channel MPC SNA devices.
+	  MPC is an SNA protocol device used by Communication Server for Linux.
+	  To compile as a module, choose M. The module name is ctcm.ko.
 	  To compile into the kernel, choose Y.
 	  If you do not need any channel-to-channel connection, choose N.
 
@@ -84,7 +86,7 @@ config QETH_VLAN
 	  802.1q VLAN support in the qeth device driver.
 
 config CCWGROUP
- 	tristate
-	default (LCS || CTC || QETH)
+	tristate
+	default (LCS || CTCM || QETH)
 
 endmenu
diff --git a/drivers/s390/net/Makefile b/drivers/s390/net/Makefile
index bbe3ab2e93d9..f6d189a8a451 100644
--- a/drivers/s390/net/Makefile
+++ b/drivers/s390/net/Makefile
@@ -2,11 +2,10 @@
 # S/390 network devices
 #
 
-ctc-objs := ctcmain.o ctcdbug.o
-
+ctcm-y += ctcm_main.o ctcm_fsms.o ctcm_mpc.o ctcm_sysfs.o ctcm_dbug.o
+obj-$(CONFIG_CTCM) += ctcm.o fsm.o cu3088.o
 obj-$(CONFIG_NETIUCV) += netiucv.o fsm.o
 obj-$(CONFIG_SMSGIUCV) += smsgiucv.o
-obj-$(CONFIG_CTC) += ctc.o fsm.o cu3088.o
 obj-$(CONFIG_LCS) += lcs.o cu3088.o
 obj-$(CONFIG_CLAW) += claw.o cu3088.o
 qeth-y := qeth_main.o qeth_mpc.o qeth_sys.o qeth_eddp.o 
diff --git a/drivers/s390/net/ctcm_dbug.c b/drivers/s390/net/ctcm_dbug.c
new file mode 100644
index 000000000000..8eb25d00b2e7
--- /dev/null
+++ b/drivers/s390/net/ctcm_dbug.c
@@ -0,0 +1,67 @@
+/*
+ *	drivers/s390/net/ctcm_dbug.c
+ *
+ *	Copyright IBM Corp. 2001, 2007
+ *	Authors:	Peter Tiedemann (ptiedem@de.ibm.com)
+ *
+ */
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+#include <linux/sysctl.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include "ctcm_dbug.h"
+
+/*
+ * Debug Facility Stuff
+ */
+
+DEFINE_PER_CPU(char[256], ctcm_dbf_txt_buf);
+
+struct ctcm_dbf_info ctcm_dbf[CTCM_DBF_INFOS] = {
+	[CTCM_DBF_SETUP]	= {"ctc_setup", 8, 1, 64, 5, NULL},
+	[CTCM_DBF_ERROR]	= {"ctc_error", 8, 1, 64, 3, NULL},
+	[CTCM_DBF_TRACE]	= {"ctc_trace", 8, 1, 64, 3, NULL},
+	[CTCM_DBF_MPC_SETUP]	= {"mpc_setup", 8, 1, 64, 5, NULL},
+	[CTCM_DBF_MPC_ERROR]	= {"mpc_error", 8, 1, 64, 3, NULL},
+	[CTCM_DBF_MPC_TRACE]	= {"mpc_trace", 8, 1, 64, 3, NULL},
+};
+
+void ctcm_unregister_dbf_views(void)
+{
+	int x;
+	for (x = 0; x < CTCM_DBF_INFOS; x++) {
+		debug_unregister(ctcm_dbf[x].id);
+		ctcm_dbf[x].id = NULL;
+	}
+}
+
+int ctcm_register_dbf_views(void)
+{
+	int x;
+	for (x = 0; x < CTCM_DBF_INFOS; x++) {
+		/* register the areas */
+		ctcm_dbf[x].id = debug_register(ctcm_dbf[x].name,
+						ctcm_dbf[x].pages,
+						ctcm_dbf[x].areas,
+						ctcm_dbf[x].len);
+		if (ctcm_dbf[x].id == NULL) {
+			ctcm_unregister_dbf_views();
+			return -ENOMEM;
+		}
+
+		/* register a view */
+		debug_register_view(ctcm_dbf[x].id, &debug_hex_ascii_view);
+		/* set a passing level */
+		debug_set_level(ctcm_dbf[x].id, ctcm_dbf[x].level);
+	}
+
+	return 0;
+}
+
diff --git a/drivers/s390/net/ctcm_dbug.h b/drivers/s390/net/ctcm_dbug.h
new file mode 100644
index 000000000000..fdff34fe59a2
--- /dev/null
+++ b/drivers/s390/net/ctcm_dbug.h
@@ -0,0 +1,158 @@
+/*
+ *	drivers/s390/net/ctcm_dbug.h
+ *
+ *	Copyright IBM Corp. 2001, 2007
+ *	Authors:	Peter Tiedemann (ptiedem@de.ibm.com)
+ *
+ */
+
+#ifndef _CTCM_DBUG_H_
+#define _CTCM_DBUG_H_
+
+/*
+ * Debug Facility stuff
+ */
+
+#include <asm/debug.h>
+
+#ifdef DEBUG
+ #define do_debug 1
+#else
+ #define do_debug 0
+#endif
+#ifdef DEBUGDATA
+ #define do_debug_data 1
+#else
+ #define do_debug_data 0
+#endif
+#ifdef DEBUGCCW
+ #define do_debug_ccw 1
+#else
+ #define do_debug_ccw 0
+#endif
+
+/* define dbf debug levels similar to kernel msg levels */
+#define	CTC_DBF_ALWAYS	0	/* always print this 			*/
+#define	CTC_DBF_EMERG	0	/* system is unusable			*/
+#define	CTC_DBF_ALERT	1	/* action must be taken immediately	*/
+#define	CTC_DBF_CRIT	2	/* critical conditions			*/
+#define	CTC_DBF_ERROR	3	/* error conditions			*/
+#define	CTC_DBF_WARN	4	/* warning conditions			*/
+#define	CTC_DBF_NOTICE	5	/* normal but significant condition	*/
+#define	CTC_DBF_INFO	5	/* informational			*/
+#define	CTC_DBF_DEBUG	6	/* debug-level messages			*/
+
+DECLARE_PER_CPU(char[256], ctcm_dbf_txt_buf);
+
+enum ctcm_dbf_names {
+	CTCM_DBF_SETUP,
+	CTCM_DBF_ERROR,
+	CTCM_DBF_TRACE,
+	CTCM_DBF_MPC_SETUP,
+	CTCM_DBF_MPC_ERROR,
+	CTCM_DBF_MPC_TRACE,
+	CTCM_DBF_INFOS	/* must be last element */
+};
+
+struct ctcm_dbf_info {
+	char name[DEBUG_MAX_NAME_LEN];
+	int pages;
+	int areas;
+	int len;
+	int level;
+	debug_info_t *id;
+};
+
+extern struct ctcm_dbf_info ctcm_dbf[CTCM_DBF_INFOS];
+
+int ctcm_register_dbf_views(void);
+void ctcm_unregister_dbf_views(void);
+
+static inline const char *strtail(const char *s, int n)
+{
+	int l = strlen(s);
+	return (l > n) ? s + (l - n) : s;
+}
+
+/* sort out levels early to avoid unnecessary sprintfs */
+static inline int ctcm_dbf_passes(debug_info_t *dbf_grp, int level)
+{
+	return (dbf_grp->level >= level);
+}
+
+#define CTCM_FUNTAIL strtail((char *)__func__, 16)
+
+#define CTCM_DBF_TEXT(name, level, text) \
+	do { \
+		debug_text_event(ctcm_dbf[CTCM_DBF_##name].id, level, text); \
+	} while (0)
+
+#define CTCM_DBF_HEX(name, level, addr, len) \
+	do { \
+		debug_event(ctcm_dbf[CTCM_DBF_##name].id, \
+					level, (void *)(addr), len); \
+	} while (0)
+
+#define CTCM_DBF_TEXT_(name, level, text...) \
+	do { \
+		if (ctcm_dbf_passes(ctcm_dbf[CTCM_DBF_##name].id, level)) { \
+			char *ctcm_dbf_txt_buf = \
+					 get_cpu_var(ctcm_dbf_txt_buf); \
+			sprintf(ctcm_dbf_txt_buf, text); \
+			debug_text_event(ctcm_dbf[CTCM_DBF_##name].id, \
+					level, ctcm_dbf_txt_buf); \
+			put_cpu_var(ctcm_dbf_txt_buf); \
+		} \
+	} while (0)
+
+/*
+ * cat : one of {setup, mpc_setup, trace, mpc_trace, error, mpc_error}.
+ * dev : netdevice with valid name field.
+ * text: any text string.
+ */
+#define CTCM_DBF_DEV_NAME(cat, dev, text) \
+	do { \
+		CTCM_DBF_TEXT_(cat, CTC_DBF_INFO, "%s(%s) : %s", \
+			CTCM_FUNTAIL, dev->name, text); \
+	} while (0)
+
+#define MPC_DBF_DEV_NAME(cat, dev, text) \
+	do { \
+		CTCM_DBF_TEXT_(MPC_##cat, CTC_DBF_INFO, "%s(%s) : %s", \
+			CTCM_FUNTAIL, dev->name, text); \
+	} while (0)
+
+#define CTCMY_DBF_DEV_NAME(cat, dev, text) \
+	do { \
+		if (IS_MPCDEV(dev)) \
+			MPC_DBF_DEV_NAME(cat, dev, text); \
+		else \
+			CTCM_DBF_DEV_NAME(cat, dev, text); \
+	} while (0)
+
+/*
+ * cat : one of {setup, mpc_setup, trace, mpc_trace, error, mpc_error}.
+ * dev : netdevice.
+ * text: any text string.
+ */
+#define CTCM_DBF_DEV(cat, dev, text) \
+	do { \
+		CTCM_DBF_TEXT_(cat, CTC_DBF_INFO, "%s(%p) : %s", \
+			CTCM_FUNTAIL, dev, text); \
+	} while (0)
+
+#define MPC_DBF_DEV(cat, dev, text) \
+	do { \
+		CTCM_DBF_TEXT_(MPC_##cat, CTC_DBF_INFO, "%s(%p) : %s", \
+			CTCM_FUNTAIL, dev, text); \
+	} while (0)
+
+#define CTCMY_DBF_DEV(cat, dev, text) \
+	do { \
+		if (IS_MPCDEV(dev)) \
+			MPC_DBF_DEV(cat, dev, text); \
+		else \
+			CTCM_DBF_DEV(cat, dev, text); \
+	} while (0)
+
+#endif
diff --git a/drivers/s390/net/ctcm_fsms.c b/drivers/s390/net/ctcm_fsms.c
new file mode 100644
index 000000000000..2a106f3a076d
--- /dev/null
+++ b/drivers/s390/net/ctcm_fsms.c
@@ -0,0 +1,2347 @@
+/*
+ * drivers/s390/net/ctcm_fsms.c
+ *
+ * Copyright IBM Corp. 2001, 2007
+ * Authors:	Fritz Elfert (felfert@millenux.com)
+ * 		Peter Tiedemann (ptiedem@de.ibm.com)
+ *	MPC additions :
+ *		Belinda Thompson (belindat@us.ibm.com)
+ *		Andy Richter (richtera@us.ibm.com)
+ */
+
+#undef DEBUG
+#undef DEBUGDATA
+#undef DEBUGCCW
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/timer.h>
+#include <linux/bitops.h>
+
+#include <linux/signal.h>
+#include <linux/string.h>
+
+#include <linux/ip.h>
+#include <linux/if_arp.h>
+#include <linux/tcp.h>
+#include <linux/skbuff.h>
+#include <linux/ctype.h>
+#include <net/dst.h>
+
+#include <linux/io.h>
+#include <asm/ccwdev.h>
+#include <asm/ccwgroup.h>
+#include <linux/uaccess.h>
+
+#include <asm/idals.h>
+
+#include "fsm.h"
+#include "cu3088.h"
+
+#include "ctcm_dbug.h"
+#include "ctcm_main.h"
+#include "ctcm_fsms.h"
+
+const char *dev_state_names[] = {
+	[DEV_STATE_STOPPED]		= "Stopped",
+	[DEV_STATE_STARTWAIT_RXTX]	= "StartWait RXTX",
+	[DEV_STATE_STARTWAIT_RX]	= "StartWait RX",
+	[DEV_STATE_STARTWAIT_TX]	= "StartWait TX",
+	[DEV_STATE_STOPWAIT_RXTX]	= "StopWait RXTX",
+	[DEV_STATE_STOPWAIT_RX]		= "StopWait RX",
+	[DEV_STATE_STOPWAIT_TX]		= "StopWait TX",
+	[DEV_STATE_RUNNING]		= "Running",
+};
+
+const char *dev_event_names[] = {
+	[DEV_EVENT_START]	= "Start",
+	[DEV_EVENT_STOP]	= "Stop",
+	[DEV_EVENT_RXUP]	= "RX up",
+	[DEV_EVENT_TXUP]	= "TX up",
+	[DEV_EVENT_RXDOWN]	= "RX down",
+	[DEV_EVENT_TXDOWN]	= "TX down",
+	[DEV_EVENT_RESTART]	= "Restart",
+};
+
+const char *ctc_ch_event_names[] = {
+	[CTC_EVENT_IO_SUCCESS]	= "ccw_device success",
+	[CTC_EVENT_IO_EBUSY]	= "ccw_device busy",
+	[CTC_EVENT_IO_ENODEV]	= "ccw_device enodev",
+	[CTC_EVENT_IO_UNKNOWN]	= "ccw_device unknown",
+	[CTC_EVENT_ATTNBUSY]	= "Status ATTN & BUSY",
+	[CTC_EVENT_ATTN]	= "Status ATTN",
+	[CTC_EVENT_BUSY]	= "Status BUSY",
+	[CTC_EVENT_UC_RCRESET]	= "Unit check remote reset",
+	[CTC_EVENT_UC_RSRESET]	= "Unit check remote system reset",
+	[CTC_EVENT_UC_TXTIMEOUT] = "Unit check TX timeout",
+	[CTC_EVENT_UC_TXPARITY]	= "Unit check TX parity",
+	[CTC_EVENT_UC_HWFAIL]	= "Unit check Hardware failure",
+	[CTC_EVENT_UC_RXPARITY]	= "Unit check RX parity",
+	[CTC_EVENT_UC_ZERO]	= "Unit check ZERO",
+	[CTC_EVENT_UC_UNKNOWN]	= "Unit check Unknown",
+	[CTC_EVENT_SC_UNKNOWN]	= "SubChannel check Unknown",
+	[CTC_EVENT_MC_FAIL]	= "Machine check failure",
+	[CTC_EVENT_MC_GOOD]	= "Machine check operational",
+	[CTC_EVENT_IRQ]		= "IRQ normal",
+	[CTC_EVENT_FINSTAT]	= "IRQ final",
+	[CTC_EVENT_TIMER]	= "Timer",
+	[CTC_EVENT_START]	= "Start",
+	[CTC_EVENT_STOP]	= "Stop",
+	/*
+	* additional MPC events
+	*/
+	[CTC_EVENT_SEND_XID]	= "XID Exchange",
+	[CTC_EVENT_RSWEEP_TIMER] = "MPC Group Sweep Timer",
+};
+
+const char *ctc_ch_state_names[] = {
+	[CTC_STATE_IDLE]	= "Idle",
+	[CTC_STATE_STOPPED]	= "Stopped",
+	[CTC_STATE_STARTWAIT]	= "StartWait",
+	[CTC_STATE_STARTRETRY]	= "StartRetry",
+	[CTC_STATE_SETUPWAIT]	= "SetupWait",
+	[CTC_STATE_RXINIT]	= "RX init",
+	[CTC_STATE_TXINIT]	= "TX init",
+	[CTC_STATE_RX]		= "RX",
+	[CTC_STATE_TX]		= "TX",
+	[CTC_STATE_RXIDLE]	= "RX idle",
+	[CTC_STATE_TXIDLE]	= "TX idle",
+	[CTC_STATE_RXERR]	= "RX error",
+	[CTC_STATE_TXERR]	= "TX error",
+	[CTC_STATE_TERM]	= "Terminating",
+	[CTC_STATE_DTERM]	= "Restarting",
+	[CTC_STATE_NOTOP]	= "Not operational",
+	/*
+	* additional MPC states
+	*/
+	[CH_XID0_PENDING]	= "Pending XID0 Start",
+	[CH_XID0_INPROGRESS]	= "In XID0 Negotiations ",
+	[CH_XID7_PENDING]	= "Pending XID7 P1 Start",
+	[CH_XID7_PENDING1]	= "Active XID7 P1 Exchange ",
+	[CH_XID7_PENDING2]	= "Pending XID7 P2 Start ",
+	[CH_XID7_PENDING3]	= "Active XID7 P2 Exchange ",
+	[CH_XID7_PENDING4]	= "XID7 Complete - Pending READY ",
+};
+
+static void ctcm_action_nop(fsm_instance *fi, int event, void *arg);
+
+/*
+ * ----- static ctcm actions for channel statemachine -----
+ *
+*/
+static void chx_txdone(fsm_instance *fi, int event, void *arg);
+static void chx_rx(fsm_instance *fi, int event, void *arg);
+static void chx_rxidle(fsm_instance *fi, int event, void *arg);
+static void chx_firstio(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_setmode(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_start(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_haltio(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_stopped(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_stop(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_fail(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_setuperr(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_restart(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_rxiniterr(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_rxinitfail(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_rxdisc(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_txiniterr(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_txretry(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_iofatal(fsm_instance *fi, int event, void *arg);
+
+/*
+ * ----- static ctcmpc actions for ctcmpc channel statemachine -----
+ *
+*/
+static void ctcmpc_chx_txdone(fsm_instance *fi, int event, void *arg);
+static void ctcmpc_chx_rx(fsm_instance *fi, int event, void *arg);
+static void ctcmpc_chx_firstio(fsm_instance *fi, int event, void *arg);
+/* shared :
+static void ctcm_chx_setmode(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_start(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_haltio(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_stopped(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_stop(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_fail(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_setuperr(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_restart(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_rxiniterr(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_rxinitfail(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_rxdisc(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_txiniterr(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_txretry(fsm_instance *fi, int event, void *arg);
+static void ctcm_chx_iofatal(fsm_instance *fi, int event, void *arg);
+*/
+static void ctcmpc_chx_attn(fsm_instance *fsm, int event, void *arg);
+static void ctcmpc_chx_attnbusy(fsm_instance *, int, void *);
+static void ctcmpc_chx_resend(fsm_instance *, int, void *);
+static void ctcmpc_chx_send_sweep(fsm_instance *fsm, int event, void *arg);
+
+/**
+ * Check return code of a preceeding ccw_device call, halt_IO etc...
+ *
+ * ch	:	The channel, the error belongs to.
+ * Returns the error code (!= 0) to inspect.
+ */
+void ctcm_ccw_check_rc(struct channel *ch, int rc, char *msg)
+{
+	CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
+			"ccw error %s (%s): %04x\n", ch->id, msg, rc);
+	switch (rc) {
+	case -EBUSY:
+		ctcm_pr_warn("%s (%s): Busy !\n", ch->id, msg);
+		fsm_event(ch->fsm, CTC_EVENT_IO_EBUSY, ch);
+		break;
+	case -ENODEV:
+		ctcm_pr_emerg("%s (%s): Invalid device called for IO\n",
+			     ch->id, msg);
+		fsm_event(ch->fsm, CTC_EVENT_IO_ENODEV, ch);
+		break;
+	default:
+		ctcm_pr_emerg("%s (%s): Unknown error in do_IO %04x\n",
+			     ch->id, msg, rc);
+		fsm_event(ch->fsm, CTC_EVENT_IO_UNKNOWN, ch);
+	}
+}
+
+void ctcm_purge_skb_queue(struct sk_buff_head *q)
+{
+	struct sk_buff *skb;
+
+	CTCM_DBF_TEXT(TRACE, 3, __FUNCTION__);
+
+	while ((skb = skb_dequeue(q))) {
+		atomic_dec(&skb->users);
+		dev_kfree_skb_any(skb);
+	}
+}
+
+/**
+ * NOP action for statemachines
+ */
+static void ctcm_action_nop(fsm_instance *fi, int event, void *arg)
+{
+}
+
+/*
+ * Actions for channel - statemachines.
+ */
+
+/**
+ * Normal data has been send. Free the corresponding
+ * skb (it's in io_queue), reset dev->tbusy and
+ * revert to idle state.
+ *
+ * fi		An instance of a channel statemachine.
+ * event	The event, just happened.
+ * arg		Generic pointer, casted from channel * upon call.
+ */
+static void chx_txdone(fsm_instance *fi, int event, void *arg)
+{
+	struct channel *ch = arg;
+	struct net_device *dev = ch->netdev;
+	struct ctcm_priv *priv = dev->priv;
+	struct sk_buff *skb;
+	int first = 1;
+	int i;
+	unsigned long duration;
+	struct timespec done_stamp = current_kernel_time(); /* xtime */
+
+	duration =
+	    (done_stamp.tv_sec - ch->prof.send_stamp.tv_sec) * 1000000 +
+	    (done_stamp.tv_nsec - ch->prof.send_stamp.tv_nsec) / 1000;
+	if (duration > ch->prof.tx_time)
+		ch->prof.tx_time = duration;
+
+	if (ch->irb->scsw.count != 0)
+		ctcm_pr_debug("%s: TX not complete, remaining %d bytes\n",
+			     dev->name, ch->irb->scsw.count);
+	fsm_deltimer(&ch->timer);
+	while ((skb = skb_dequeue(&ch->io_queue))) {
+		priv->stats.tx_packets++;
+		priv->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
+		if (first) {
+			priv->stats.tx_bytes += 2;
+			first = 0;
+		}
+		atomic_dec(&skb->users);
+		dev_kfree_skb_irq(skb);
+	}
+	spin_lock(&ch->collect_lock);
+	clear_normalized_cda(&ch->ccw[4]);
+	if (ch->collect_len > 0) {
+		int rc;
+
+		if (ctcm_checkalloc_buffer(ch)) {
+			spin_unlock(&ch->collect_lock);
+			return;
+		}
+		ch->trans_skb->data = ch->trans_skb_data;
+		skb_reset_tail_pointer(ch->trans_skb);
+		ch->trans_skb->len = 0;
+		if (ch->prof.maxmulti < (ch->collect_len + 2))
+			ch->prof.maxmulti = ch->collect_len + 2;
+		if (ch->prof.maxcqueue < skb_queue_len(&ch->collect_queue))
+			ch->prof.maxcqueue = skb_queue_len(&ch->collect_queue);
+		*((__u16 *)skb_put(ch->trans_skb, 2)) = ch->collect_len + 2;
+		i = 0;
+		while ((skb = skb_dequeue(&ch->collect_queue))) {
+			skb_copy_from_linear_data(skb,
+				skb_put(ch->trans_skb, skb->len), skb->len);
+			priv->stats.tx_packets++;
+			priv->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
+			atomic_dec(&skb->users);
+			dev_kfree_skb_irq(skb);
+			i++;
+		}
+		ch->collect_len = 0;
+		spin_unlock(&ch->collect_lock);
+		ch->ccw[1].count = ch->trans_skb->len;
+		fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
+		ch->prof.send_stamp = current_kernel_time(); /* xtime */
+		rc = ccw_device_start(ch->cdev, &ch->ccw[0],
+						(unsigned long)ch, 0xff, 0);
+		ch->prof.doios_multi++;
+		if (rc != 0) {
+			priv->stats.tx_dropped += i;
+			priv->stats.tx_errors += i;
+			fsm_deltimer(&ch->timer);
+			ctcm_ccw_check_rc(ch, rc, "chained TX");
+		}
+	} else {
+		spin_unlock(&ch->collect_lock);
+		fsm_newstate(fi, CTC_STATE_TXIDLE);
+	}
+	ctcm_clear_busy_do(dev);
+}
+
+/**
+ * Initial data is sent.
+ * Notify device statemachine that we are up and
+ * running.
+ *
+ * fi		An instance of a channel statemachine.
+ * event	The event, just happened.
+ * arg		Generic pointer, casted from channel * upon call.
+ */
+void ctcm_chx_txidle(fsm_instance *fi, int event, void *arg)
+{
+	struct channel *ch = arg;
+	struct net_device *dev = ch->netdev;
+	struct ctcm_priv *priv = dev->priv;
+
+	CTCM_DBF_TEXT(TRACE, 6, __FUNCTION__);
+	fsm_deltimer(&ch->timer);
+	fsm_newstate(fi, CTC_STATE_TXIDLE);
+	fsm_event(priv->fsm, DEV_EVENT_TXUP, ch->netdev);
+}
+
+/**
+ * Got normal data, check for sanity, queue it up, allocate new buffer
+ * trigger bottom half, and initiate next read.
+ *
+ * fi		An instance of a channel statemachine.
+ * event	The event, just happened.
+ * arg		Generic pointer, casted from channel * upon call.
+ */
+static void chx_rx(fsm_instance *fi, int event, void *arg)
+{
+	struct channel *ch = arg;
+	struct net_device *dev = ch->netdev;
+	struct ctcm_priv *priv = dev->priv;
+	int len = ch->max_bufsize - ch->irb->scsw.count;
+	struct sk_buff *skb = ch->trans_skb;
+	__u16 block_len = *((__u16 *)skb->data);
+	int check_len;
+	int rc;
+
+	fsm_deltimer(&ch->timer);
+	if (len < 8) {
+		ctcm_pr_debug("%s: got packet with length %d < 8\n",
+			     dev->name, len);
+		priv->stats.rx_dropped++;
+		priv->stats.rx_length_errors++;
+						goto again;
+	}
+	if (len > ch->max_bufsize) {
+		ctcm_pr_debug("%s: got packet with length %d > %d\n",
+			     dev->name, len, ch->max_bufsize);
+		priv->stats.rx_dropped++;
+		priv->stats.rx_length_errors++;
+						goto again;
+	}
+
+	/*
+	 * VM TCP seems to have a bug sending 2 trailing bytes of garbage.
+	 */
+	switch (ch->protocol) {
+	case CTCM_PROTO_S390:
+	case CTCM_PROTO_OS390:
+		check_len = block_len + 2;
+		break;
+	default:
+		check_len = block_len;
+		break;
+	}
+	if ((len < block_len) || (len > check_len)) {
+		ctcm_pr_debug("%s: got block length %d != rx length %d\n",
+			     dev->name, block_len, len);
+		if (do_debug)
+			ctcmpc_dump_skb(skb, 0);
+
+		*((__u16 *)skb->data) = len;
+		priv->stats.rx_dropped++;
+		priv->stats.rx_length_errors++;
+						goto again;
+	}
+	block_len -= 2;
+	if (block_len > 0) {
+		*((__u16 *)skb->data) = block_len;
+		ctcm_unpack_skb(ch, skb);
+	}
+ again:
+	skb->data = ch->trans_skb_data;
+	skb_reset_tail_pointer(skb);
+	skb->len = 0;
+	if (ctcm_checkalloc_buffer(ch))
+		return;
+	ch->ccw[1].count = ch->max_bufsize;
+	rc = ccw_device_start(ch->cdev, &ch->ccw[0],
+					(unsigned long)ch, 0xff, 0);
+	if (rc != 0)
+		ctcm_ccw_check_rc(ch, rc, "normal RX");
+}
+
+/**
+ * Initialize connection by sending a __u16 of value 0.
+ *
+ * fi		An instance of a channel statemachine.
+ * event	The event, just happened.
+ * arg		Generic pointer, casted from channel * upon call.
+ */
+static void chx_firstio(fsm_instance *fi, int event, void *arg)
+{
+	struct channel *ch = arg;
+	int rc;
+
+	CTCM_DBF_TEXT(TRACE, 6, __FUNCTION__);
+
+	if (fsm_getstate(fi) == CTC_STATE_TXIDLE)
+		ctcm_pr_debug("%s: remote side issued READ?, init.\n", ch->id);
+	fsm_deltimer(&ch->timer);
+	if (ctcm_checkalloc_buffer(ch))
+		return;
+	if ((fsm_getstate(fi) == CTC_STATE_SETUPWAIT) &&
+	    (ch->protocol == CTCM_PROTO_OS390)) {
+		/* OS/390 resp. z/OS */
+		if (CHANNEL_DIRECTION(ch->flags) == READ) {
+			*((__u16 *)ch->trans_skb->data) = CTCM_INITIAL_BLOCKLEN;
+			fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC,
+				     CTC_EVENT_TIMER, ch);
+			chx_rxidle(fi, event, arg);
+		} else {
+			struct net_device *dev = ch->netdev;
+			struct ctcm_priv *priv = dev->priv;
+			fsm_newstate(fi, CTC_STATE_TXIDLE);
+			fsm_event(priv->fsm, DEV_EVENT_TXUP, dev);
+		}
+		return;
+	}
+
+	/*
+	 * Don't setup a timer for receiving the initial RX frame
+	 * if in compatibility mode, since VM TCP delays the initial
+	 * frame until it has some data to send.
+	 */
+	if ((CHANNEL_DIRECTION(ch->flags) == WRITE) ||
+	    (ch->protocol != CTCM_PROTO_S390))
+		fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
+
+	*((__u16 *)ch->trans_skb->data) = CTCM_INITIAL_BLOCKLEN;
+	ch->ccw[1].count = 2;	/* Transfer only length */
+
+	fsm_newstate(fi, (CHANNEL_DIRECTION(ch->flags) == READ)
+		     ? CTC_STATE_RXINIT : CTC_STATE_TXINIT);
+	rc = ccw_device_start(ch->cdev, &ch->ccw[0],
+					(unsigned long)ch, 0xff, 0);
+	if (rc != 0) {
+		fsm_deltimer(&ch->timer);
+		fsm_newstate(fi, CTC_STATE_SETUPWAIT);
+		ctcm_ccw_check_rc(ch, rc, "init IO");
+	}
+	/*
+	 * If in compatibility mode since we don't setup a timer, we
+	 * also signal RX channel up immediately. This enables us
+	 * to send packets early which in turn usually triggers some
+	 * reply from VM TCP which brings up the RX channel to it's
+	 * final state.
+	 */
+	if ((CHANNEL_DIRECTION(ch->flags) == READ) &&
+	    (ch->protocol == CTCM_PROTO_S390)) {
+		struct net_device *dev = ch->netdev;
+		struct ctcm_priv *priv = dev->priv;
+		fsm_event(priv->fsm, DEV_EVENT_RXUP, dev);
+	}
+}
+
+/**
+ * Got initial data, check it. If OK,
+ * notify device statemachine that we are up and
+ * running.
+ *
+ * fi		An instance of a channel statemachine.
+ * event	The event, just happened.
+ * arg		Generic pointer, casted from channel * upon call.
+ */
+static void chx_rxidle(fsm_instance *fi, int event, void *arg)
+{
+	struct channel *ch = arg;
+	struct net_device *dev = ch->netdev;
+	struct ctcm_priv *priv = dev->priv;
+	__u16 buflen;
+	int rc;
+
+	CTCM_DBF_TEXT(TRACE, 6, __FUNCTION__);
+	fsm_deltimer(&ch->timer);
+	buflen = *((__u16 *)ch->trans_skb->data);
+	if (do_debug)
+		ctcm_pr_debug("%s: Initial RX count %d\n", dev->name, buflen);
+
+	if (buflen >= CTCM_INITIAL_BLOCKLEN) {
+		if (ctcm_checkalloc_buffer(ch))
+			return;
+		ch->ccw[1].count = ch->max_bufsize;
+		fsm_newstate(fi, CTC_STATE_RXIDLE);
+		rc = ccw_device_start(ch->cdev, &ch->ccw[0],
+						(unsigned long)ch, 0xff, 0);
+		if (rc != 0) {
+			fsm_newstate(fi, CTC_STATE_RXINIT);
+			ctcm_ccw_check_rc(ch, rc, "initial RX");
+		} else
+			fsm_event(priv->fsm, DEV_EVENT_RXUP, dev);
+	} else {
+		if (do_debug)
+			ctcm_pr_debug("%s: Initial RX count %d not %d\n",
+				dev->name, buflen, CTCM_INITIAL_BLOCKLEN);
+		chx_firstio(fi, event, arg);
+	}
+}
+
+/**
+ * Set channel into extended mode.
+ *
+ * fi		An instance of a channel statemachine.
+ * event	The event, just happened.
+ * arg		Generic pointer, casted from channel * upon call.
+ */
+static void ctcm_chx_setmode(fsm_instance *fi, int event, void *arg)
+{
+	struct channel *ch = arg;
+	int rc;
+	unsigned long saveflags = 0;
+	int timeout = CTCM_TIME_5_SEC;
+
+	fsm_deltimer(&ch->timer);
+	if (IS_MPC(ch)) {
+		timeout = 1500;
+		if (do_debug)
+			ctcm_pr_debug("ctcm enter: %s(): cp=%i ch=0x%p id=%s\n",
+				__FUNCTION__, smp_processor_id(), ch, ch->id);
+	}
+	fsm_addtimer(&ch->timer, timeout, CTC_EVENT_TIMER, ch);
+	fsm_newstate(fi, CTC_STATE_SETUPWAIT);
+	if (do_debug_ccw && IS_MPC(ch))
+		ctcmpc_dumpit((char *)&ch->ccw[6], sizeof(struct ccw1) * 2);
+
+	if (event == CTC_EVENT_TIMER)	/* only for timer not yet locked */
+		spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
+			/* Such conditional locking is undeterministic in
+			 * static view. => ignore sparse warnings here. */
+
+	rc = ccw_device_start(ch->cdev, &ch->ccw[6],
+					(unsigned long)ch, 0xff, 0);
+	if (event == CTC_EVENT_TIMER)	/* see above comments */
+		spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
+	if (rc != 0) {
+		fsm_deltimer(&ch->timer);
+		fsm_newstate(fi, CTC_STATE_STARTWAIT);
+		ctcm_ccw_check_rc(ch, rc, "set Mode");
+	} else
+		ch->retry = 0;
+}
+
+/**
+ * Setup channel.
+ *
+ * fi		An instance of a channel statemachine.
+ * event	The event, just happened.
+ * arg		Generic pointer, casted from channel * upon call.
+ */
+static void ctcm_chx_start(fsm_instance *fi, int event, void *arg)
+{
+	struct channel *ch = arg;
+	int rc;
+	struct net_device *dev;
+	unsigned long saveflags;
+
+	CTCM_DBF_TEXT(TRACE, 5, __FUNCTION__);
+	if (ch == NULL) {
+		ctcm_pr_warn("chx_start ch=NULL\n");
+		return;
+	}
+	if (ch->netdev == NULL) {
+		ctcm_pr_warn("chx_start dev=NULL, id=%s\n", ch->id);
+		return;
+	}
+	dev = ch->netdev;
+
+	if (do_debug)
+		ctcm_pr_debug("%s: %s channel start\n", dev->name,
+			(CHANNEL_DIRECTION(ch->flags) == READ) ? "RX" : "TX");
+
+	if (ch->trans_skb != NULL) {
+		clear_normalized_cda(&ch->ccw[1]);
+		dev_kfree_skb(ch->trans_skb);
+		ch->trans_skb = NULL;
+	}
+	if (CHANNEL_DIRECTION(ch->flags) == READ) {
+		ch->ccw[1].cmd_code = CCW_CMD_READ;
+		ch->ccw[1].flags = CCW_FLAG_SLI;
+		ch->ccw[1].count = 0;
+	} else {
+		ch->ccw[1].cmd_code = CCW_CMD_WRITE;
+		ch->ccw[1].flags = CCW_FLAG_SLI | CCW_FLAG_CC;
+		ch->ccw[1].count = 0;
+	}
+	if (ctcm_checkalloc_buffer(ch)) {
+		ctcm_pr_notice("%s: %s trans_skb allocation delayed "
+				"until first transfer\n", dev->name,
+			(CHANNEL_DIRECTION(ch->flags) == READ) ? "RX" : "TX");
+	}
+
+	ch->ccw[0].cmd_code = CCW_CMD_PREPARE;
+	ch->ccw[0].flags = CCW_FLAG_SLI | CCW_FLAG_CC;
+	ch->ccw[0].count = 0;
+	ch->ccw[0].cda = 0;
+	ch->ccw[2].cmd_code = CCW_CMD_NOOP;	/* jointed CE + DE */
+	ch->ccw[2].flags = CCW_FLAG_SLI;
+	ch->ccw[2].count = 0;
+	ch->ccw[2].cda = 0;
+	memcpy(&ch->ccw[3], &ch->ccw[0], sizeof(struct ccw1) * 3);
+	ch->ccw[4].cda = 0;
+	ch->ccw[4].flags &= ~CCW_FLAG_IDA;
+
+	fsm_newstate(fi, CTC_STATE_STARTWAIT);
+	fsm_addtimer(&ch->timer, 1000, CTC_EVENT_TIMER, ch);
+	spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
+	rc = ccw_device_halt(ch->cdev, (unsigned long)ch);
+	spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
+	if (rc != 0) {
+		if (rc != -EBUSY)
+			fsm_deltimer(&ch->timer);
+		ctcm_ccw_check_rc(ch, rc, "initial HaltIO");
+	}
+}
+
+/**
+ * Shutdown a channel.
+ *
+ * fi		An instance of a channel statemachine.
+ * event	The event, just happened.
+ * arg		Generic pointer, casted from channel * upon call.
+ */
+static void ctcm_chx_haltio(fsm_instance *fi, int event, void *arg)
+{
+	struct channel *ch = arg;
+	unsigned long saveflags = 0;
+	int rc;
+	int oldstate;
+
+	CTCM_DBF_TEXT(TRACE, 2, __FUNCTION__);
+	fsm_deltimer(&ch->timer);
+	if (IS_MPC(ch))
+		fsm_deltimer(&ch->sweep_timer);
+
+	fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
+
+	if (event == CTC_EVENT_STOP)	/* only for STOP not yet locked */
+		spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
+			/* Such conditional locking is undeterministic in
+			 * static view. => ignore sparse warnings here. */
+	oldstate = fsm_getstate(fi);
+	fsm_newstate(fi, CTC_STATE_TERM);
+	rc = ccw_device_halt(ch->cdev, (unsigned long)ch);
+
+	if (event == CTC_EVENT_STOP)
+		spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
+			/* see remark above about conditional locking */
+
+	if (rc != 0 && rc != -EBUSY) {
+		fsm_deltimer(&ch->timer);
+		if (event != CTC_EVENT_STOP) {
+			fsm_newstate(fi, oldstate);
+			ctcm_ccw_check_rc(ch, rc, (char *)__FUNCTION__);
+		}
+	}
+}
+
+/**
+ * Cleanup helper for chx_fail and chx_stopped
+ * cleanup channels queue and notify interface statemachine.
+ *
+ * fi		An instance of a channel statemachine.
+ * state	The next state (depending on caller).
+ * ch		The channel to operate on.
+ */
+static void ctcm_chx_cleanup(fsm_instance *fi, int state,
+		struct channel *ch)
+{
+	struct net_device *dev = ch->netdev;
+	struct ctcm_priv *priv = dev->priv;
+
+	CTCM_DBF_TEXT(TRACE, 3, __FUNCTION__);
+
+	fsm_deltimer(&ch->timer);
+	if (IS_MPC(ch))
+		fsm_deltimer(&ch->sweep_timer);
+
+	fsm_newstate(fi, state);
+	if (state == CTC_STATE_STOPPED && ch->trans_skb != NULL) {
+		clear_normalized_cda(&ch->ccw[1]);
+		dev_kfree_skb_any(ch->trans_skb);
+		ch->trans_skb = NULL;
+	}
+
+	ch->th_seg = 0x00;
+	ch->th_seq_num = 0x00;
+	if (CHANNEL_DIRECTION(ch->flags) == READ) {
+		skb_queue_purge(&ch->io_queue);
+		fsm_event(priv->fsm, DEV_EVENT_RXDOWN, dev);
+	} else {
+		ctcm_purge_skb_queue(&ch->io_queue);
+		if (IS_MPC(ch))
+			ctcm_purge_skb_queue(&ch->sweep_queue);
+		spin_lock(&ch->collect_loc