/*
   * IUCV base infrastructure.
   *

   * Copyright IBM Corp. 2001, 2009
   *

   * Author(s):
   *    Original source:
   *	Alan Altmark (Alan_Altmark@us.ibm.com)	Sept. 2000
   *	Xenia Tkatschow (xenia@us.ibm.com)
   *    2Gb awareness and general cleanup:
   *	Fritz Elfert (elfert@de.ibm.com, felfert@millenux.com)
   *    Rewritten for af_iucv:
   *	Martin Schwidefsky <schwidefsky@de.ibm.com>

   *    PM functions:
   *	Ursula Braun (ursula.braun@de.ibm.com)

   *
   * Documentation used:
   *    The original source
   *    CP Programming Service, IBM document # SC24-5760
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2, or (at your option)
   * any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */

  #define KMSG_COMPONENT "iucv"
  #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

  #include <linux/kernel_stat.h>

  #include <linux/module.h>
  #include <linux/moduleparam.h>

  #include <linux/spinlock.h>
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/list.h>
  #include <linux/errno.h>
  #include <linux/err.h>
  #include <linux/device.h>
  #include <linux/cpu.h>

  #include <linux/reboot.h>

  #include <net/iucv/iucv.h>

  #include <linux/atomic.h>

  #include <asm/ebcdic.h>
  #include <asm/io.h>

  #include <asm/irq.h>

  #include <asm/smp.h>
  
  /*
   * FLAGS:
   * All flags are defined in the field IPFLAGS1 of each function
   * and can be found in CP Programming Services.
   * IPSRCCLS - Indicates you have specified a source class.
   * IPTRGCLS - Indicates you have specified a target class.
   * IPFGPID  - Indicates you have specified a pathid.
   * IPFGMID  - Indicates you have specified a message ID.
   * IPNORPY  - Indicates a one-way message. No reply expected.
   * IPALL    - Indicates that all paths are affected.
   */
  #define IUCV_IPSRCCLS	0x01
  #define IUCV_IPTRGCLS	0x01
  #define IUCV_IPFGPID	0x02
  #define IUCV_IPFGMID	0x04
  #define IUCV_IPNORPY	0x10
  #define IUCV_IPALL	0x80

  static int iucv_bus_match(struct device *dev, struct device_driver *drv)

  {
  	return 0;
  }

  enum iucv_pm_states {
  	IUCV_PM_INITIAL = 0,
  	IUCV_PM_FREEZING = 1,
  	IUCV_PM_THAWING = 2,
  	IUCV_PM_RESTORING = 3,
  };
  static enum iucv_pm_states iucv_pm_state;

  static int iucv_pm_prepare(struct device *);
  static void iucv_pm_complete(struct device *);
  static int iucv_pm_freeze(struct device *);
  static int iucv_pm_thaw(struct device *);
  static int iucv_pm_restore(struct device *);

  static const struct dev_pm_ops iucv_pm_ops = {

  	.prepare = iucv_pm_prepare,
  	.complete = iucv_pm_complete,
  	.freeze = iucv_pm_freeze,
  	.thaw = iucv_pm_thaw,
  	.restore = iucv_pm_restore,
  };

  struct bus_type iucv_bus = {
  	.name = "iucv",
  	.match = iucv_bus_match,

  	.pm = &iucv_pm_ops,

  };

  EXPORT_SYMBOL(iucv_bus);

  
  struct device *iucv_root;

  EXPORT_SYMBOL(iucv_root);

  static int iucv_available;
  
  /* General IUCV interrupt structure */
  struct iucv_irq_data {
  	u16 ippathid;
  	u8  ipflags1;
  	u8  iptype;
  	u32 res2[8];
  };

  struct iucv_irq_list {

  	struct list_head list;
  	struct iucv_irq_data data;
  };

  static struct iucv_irq_data *iucv_irq_data[NR_CPUS];

  static cpumask_t iucv_buffer_cpumask = { CPU_BITS_NONE };
  static cpumask_t iucv_irq_cpumask = { CPU_BITS_NONE };

  /*
   * Queue of interrupt buffers lock for delivery via the tasklet
   * (fast but can't call smp_call_function).
   */
  static LIST_HEAD(iucv_task_queue);
  
  /*
   * The tasklet for fast delivery of iucv interrupts.
   */
  static void iucv_tasklet_fn(unsigned long);
  static DECLARE_TASKLET(iucv_tasklet, iucv_tasklet_fn,0);
  
  /*
   * Queue of interrupt buffers for delivery via a work queue
   * (slower but can call smp_call_function).
   */
  static LIST_HEAD(iucv_work_queue);
  
  /*
   * The work element to deliver path pending interrupts.
   */
  static void iucv_work_fn(struct work_struct *work);
  static DECLARE_WORK(iucv_work, iucv_work_fn);
  
  /*
   * Spinlock protecting task and work queue.
   */
  static DEFINE_SPINLOCK(iucv_queue_lock);

  
  enum iucv_command_codes {
  	IUCV_QUERY = 0,
  	IUCV_RETRIEVE_BUFFER = 2,
  	IUCV_SEND = 4,
  	IUCV_RECEIVE = 5,
  	IUCV_REPLY = 6,
  	IUCV_REJECT = 8,
  	IUCV_PURGE = 9,
  	IUCV_ACCEPT = 10,
  	IUCV_CONNECT = 11,
  	IUCV_DECLARE_BUFFER = 12,
  	IUCV_QUIESCE = 13,
  	IUCV_RESUME = 14,
  	IUCV_SEVER = 15,
  	IUCV_SETMASK = 16,

  	IUCV_SETCONTROLMASK = 17,

  };
  
  /*
   * Error messages that are used with the iucv_sever function. They get
   * converted to EBCDIC.
   */
  static char iucv_error_no_listener[16] = "NO LISTENER";
  static char iucv_error_no_memory[16] = "NO MEMORY";
  static char iucv_error_pathid[16] = "INVALID PATHID";
  
  /*
   * iucv_handler_list: List of registered handlers.
   */
  static LIST_HEAD(iucv_handler_list);
  
  /*
   * iucv_path_table: an array of iucv_path structures.
   */
  static struct iucv_path **iucv_path_table;
  static unsigned long iucv_max_pathid;
  
  /*
   * iucv_lock: spinlock protecting iucv_handler_list and iucv_pathid_table
   */
  static DEFINE_SPINLOCK(iucv_table_lock);
  
  /*

   * iucv_active_cpu: contains the number of the cpu executing the tasklet
   * or the work handler. Needed for iucv_path_sever called from tasklet.

   */

  static int iucv_active_cpu = -1;

  
  /*
   * Mutex and wait queue for iucv_register/iucv_unregister.
   */
  static DEFINE_MUTEX(iucv_register_mutex);
  
  /*
   * Counter for number of non-smp capable handlers.
   */
  static int iucv_nonsmp_handler;
  
  /*
   * IUCV control data structure. Used by iucv_path_accept, iucv_path_connect,
   * iucv_path_quiesce and iucv_path_sever.
   */
  struct iucv_cmd_control {
  	u16 ippathid;
  	u8  ipflags1;
  	u8  iprcode;
  	u16 ipmsglim;
  	u16 res1;
  	u8  ipvmid[8];
  	u8  ipuser[16];
  	u8  iptarget[8];
  } __attribute__ ((packed,aligned(8)));
  
  /*
   * Data in parameter list iucv structure. Used by iucv_message_send,
   * iucv_message_send2way and iucv_message_reply.
   */
  struct iucv_cmd_dpl {
  	u16 ippathid;
  	u8  ipflags1;
  	u8  iprcode;
  	u32 ipmsgid;
  	u32 iptrgcls;
  	u8  iprmmsg[8];
  	u32 ipsrccls;
  	u32 ipmsgtag;
  	u32 ipbfadr2;
  	u32 ipbfln2f;
  	u32 res;
  } __attribute__ ((packed,aligned(8)));
  
  /*
   * Data in buffer iucv structure. Used by iucv_message_receive,
   * iucv_message_reject, iucv_message_send, iucv_message_send2way
   * and iucv_declare_cpu.
   */
  struct iucv_cmd_db {
  	u16 ippathid;
  	u8  ipflags1;
  	u8  iprcode;
  	u32 ipmsgid;
  	u32 iptrgcls;
  	u32 ipbfadr1;
  	u32 ipbfln1f;
  	u32 ipsrccls;
  	u32 ipmsgtag;
  	u32 ipbfadr2;
  	u32 ipbfln2f;
  	u32 res;
  } __attribute__ ((packed,aligned(8)));
  
  /*
   * Purge message iucv structure. Used by iucv_message_purge.
   */
  struct iucv_cmd_purge {
  	u16 ippathid;
  	u8  ipflags1;
  	u8  iprcode;
  	u32 ipmsgid;
  	u8  ipaudit[3];
  	u8  res1[5];
  	u32 res2;
  	u32 ipsrccls;
  	u32 ipmsgtag;
  	u32 res3[3];
  } __attribute__ ((packed,aligned(8)));
  
  /*
   * Set mask iucv structure. Used by iucv_enable_cpu.
   */
  struct iucv_cmd_set_mask {
  	u8  ipmask;
  	u8  res1[2];
  	u8  iprcode;
  	u32 res2[9];
  } __attribute__ ((packed,aligned(8)));
  
  union iucv_param {
  	struct iucv_cmd_control ctrl;
  	struct iucv_cmd_dpl dpl;
  	struct iucv_cmd_db db;
  	struct iucv_cmd_purge purge;
  	struct iucv_cmd_set_mask set_mask;
  };
  
  /*
   * Anchor for per-cpu IUCV command parameter block.
   */

  static union iucv_param *iucv_param[NR_CPUS];

  static union iucv_param *iucv_param_irq[NR_CPUS];

  
  /**
   * iucv_call_b2f0
   * @code: identifier of IUCV call to CP.
   * @parm: pointer to a struct iucv_parm block
   *
   * Calls CP to execute IUCV commands.
   *
   * Returns the result of the CP IUCV call.
   */
  static inline int iucv_call_b2f0(int command, union iucv_param *parm)
  {
  	register unsigned long reg0 asm ("0");
  	register unsigned long reg1 asm ("1");
  	int ccode;
  
  	reg0 = command;
  	reg1 = virt_to_phys(parm);
  	asm volatile(
  		"	.long 0xb2f01000
  "
  		"	ipm	%0
  "
  		"	srl	%0,28
  "
  		: "=d" (ccode), "=m" (*parm), "+d" (reg0), "+a" (reg1)
  		:  "m" (*parm) : "cc");
  	return (ccode == 1) ? parm->ctrl.iprcode : ccode;
  }
  
  /**
   * iucv_query_maxconn
   *
   * Determines the maximum number of connections that may be established.
   *
   * Returns the maximum number of connections or -EPERM is IUCV is not
   * available.
   */
  static int iucv_query_maxconn(void)
  {
  	register unsigned long reg0 asm ("0");
  	register unsigned long reg1 asm ("1");
  	void *param;
  	int ccode;
  
  	param = kzalloc(sizeof(union iucv_param), GFP_KERNEL|GFP_DMA);
  	if (!param)
  		return -ENOMEM;
  	reg0 = IUCV_QUERY;
  	reg1 = (unsigned long) param;
  	asm volatile (
  		"	.long	0xb2f01000
  "
  		"	ipm	%0
  "
  		"	srl	%0,28
  "
  		: "=d" (ccode), "+d" (reg0), "+d" (reg1) : : "cc");
  	if (ccode == 0)

  		iucv_max_pathid = reg1;

  	kfree(param);
  	return ccode ? -EPERM : 0;
  }
  
  /**
   * iucv_allow_cpu
   * @data: unused
   *
   * Allow iucv interrupts on this cpu.
   */
  static void iucv_allow_cpu(void *data)
  {
  	int cpu = smp_processor_id();
  	union iucv_param *parm;
  
  	/*
  	 * Enable all iucv interrupts.
  	 * ipmask contains bits for the different interrupts
  	 *	0x80 - Flag to allow nonpriority message pending interrupts
  	 *	0x40 - Flag to allow priority message pending interrupts
  	 *	0x20 - Flag to allow nonpriority message completion interrupts
  	 *	0x10 - Flag to allow priority message completion interrupts
  	 *	0x08 - Flag to allow IUCV control interrupts
  	 */

  	parm = iucv_param_irq[cpu];

  	memset(parm, 0, sizeof(union iucv_param));
  	parm->set_mask.ipmask = 0xf8;
  	iucv_call_b2f0(IUCV_SETMASK, parm);

  	/*
  	 * Enable all iucv control interrupts.
  	 * ipmask contains bits for the different interrupts
  	 *	0x80 - Flag to allow pending connections interrupts
  	 *	0x40 - Flag to allow connection complete interrupts
  	 *	0x20 - Flag to allow connection severed interrupts
  	 *	0x10 - Flag to allow connection quiesced interrupts
  	 *	0x08 - Flag to allow connection resumed interrupts
  	 */
  	memset(parm, 0, sizeof(union iucv_param));
  	parm->set_mask.ipmask = 0xf8;
  	iucv_call_b2f0(IUCV_SETCONTROLMASK, parm);

  	/* Set indication that iucv interrupts are allowed for this cpu. */

  	cpumask_set_cpu(cpu, &iucv_irq_cpumask);

  }
  
  /**
   * iucv_block_cpu
   * @data: unused
   *
   * Block iucv interrupts on this cpu.
   */
  static void iucv_block_cpu(void *data)
  {
  	int cpu = smp_processor_id();
  	union iucv_param *parm;
  
  	/* Disable all iucv interrupts. */

  	parm = iucv_param_irq[cpu];

  	memset(parm, 0, sizeof(union iucv_param));
  	iucv_call_b2f0(IUCV_SETMASK, parm);
  
  	/* Clear indication that iucv interrupts are allowed for this cpu. */

  	cpumask_clear_cpu(cpu, &iucv_irq_cpumask);

  }
  
  /**

   * iucv_block_cpu_almost
   * @data: unused
   *
   * Allow connection-severed interrupts only on this cpu.
   */
  static void iucv_block_cpu_almost(void *data)
  {
  	int cpu = smp_processor_id();
  	union iucv_param *parm;
  
  	/* Allow iucv control interrupts only */
  	parm = iucv_param_irq[cpu];
  	memset(parm, 0, sizeof(union iucv_param));
  	parm->set_mask.ipmask = 0x08;
  	iucv_call_b2f0(IUCV_SETMASK, parm);
  	/* Allow iucv-severed interrupt only */
  	memset(parm, 0, sizeof(union iucv_param));
  	parm->set_mask.ipmask = 0x20;
  	iucv_call_b2f0(IUCV_SETCONTROLMASK, parm);
  
  	/* Clear indication that iucv interrupts are allowed for this cpu. */

  	cpumask_clear_cpu(cpu, &iucv_irq_cpumask);

  }
  
  /**

   * iucv_declare_cpu
   * @data: unused
   *

   * Declare a interrupt buffer on this cpu.

   */
  static void iucv_declare_cpu(void *data)
  {
  	int cpu = smp_processor_id();
  	union iucv_param *parm;
  	int rc;

  	if (cpumask_test_cpu(cpu, &iucv_buffer_cpumask))

  		return;
  
  	/* Declare interrupt buffer. */

  	parm = iucv_param_irq[cpu];

  	memset(parm, 0, sizeof(union iucv_param));

  	parm->db.ipbfadr1 = virt_to_phys(iucv_irq_data[cpu]);

  	rc = iucv_call_b2f0(IUCV_DECLARE_BUFFER, parm);
  	if (rc) {
  		char *err = "Unknown";

  		switch (rc) {

  		case 0x03:
  			err = "Directory error";
  			break;
  		case 0x0a:
  			err = "Invalid length";
  			break;
  		case 0x13:
  			err = "Buffer already exists";
  			break;
  		case 0x3e:
  			err = "Buffer overlap";
  			break;
  		case 0x5c:
  			err = "Paging or storage error";
  			break;
  		}

  		pr_warning("Defining an interrupt buffer on CPU %i"
  			   " failed with 0x%02x (%s)
  ", cpu, rc, err);

  		return;
  	}
  
  	/* Set indication that an iucv buffer exists for this cpu. */

  	cpumask_set_cpu(cpu, &iucv_buffer_cpumask);

  	if (iucv_nonsmp_handler == 0 || cpumask_empty(&iucv_irq_cpumask))

  		/* Enable iucv interrupts on this cpu. */
  		iucv_allow_cpu(NULL);
  	else
  		/* Disable iucv interrupts on this cpu. */
  		iucv_block_cpu(NULL);
  }
  
  /**
   * iucv_retrieve_cpu
   * @data: unused
   *
   * Retrieve interrupt buffer on this cpu.
   */
  static void iucv_retrieve_cpu(void *data)
  {
  	int cpu = smp_processor_id();
  	union iucv_param *parm;

  	if (!cpumask_test_cpu(cpu, &iucv_buffer_cpumask))

  		return;
  
  	/* Block iucv interrupts. */
  	iucv_block_cpu(NULL);
  
  	/* Retrieve interrupt buffer. */

  	parm = iucv_param_irq[cpu];

  	iucv_call_b2f0(IUCV_RETRIEVE_BUFFER, parm);
  
  	/* Clear indication that an iucv buffer exists for this cpu. */

  	cpumask_clear_cpu(cpu, &iucv_buffer_cpumask);

  }
  
  /**
   * iucv_setmask_smp
   *
   * Allow iucv interrupts on all cpus.
   */
  static void iucv_setmask_mp(void)
  {
  	int cpu;

  	get_online_cpus();

  	for_each_online_cpu(cpu)
  		/* Enable all cpus with a declared buffer. */

  		if (cpumask_test_cpu(cpu, &iucv_buffer_cpumask) &&
  		    !cpumask_test_cpu(cpu, &iucv_irq_cpumask))

  			smp_call_function_single(cpu, iucv_allow_cpu,

  						 NULL, 1);

  	put_online_cpus();

  }
  
  /**
   * iucv_setmask_up
   *

   * Allow iucv interrupts on a single cpu.

   */
  static void iucv_setmask_up(void)
  {
  	cpumask_t cpumask;
  	int cpu;
  
  	/* Disable all cpu but the first in cpu_irq_cpumask. */

  	cpumask_copy(&cpumask, &iucv_irq_cpumask);
  	cpumask_clear_cpu(cpumask_first(&iucv_irq_cpumask), &cpumask);
  	for_each_cpu(cpu, &cpumask)

  		smp_call_function_single(cpu, iucv_block_cpu, NULL, 1);

  }
  
  /**
   * iucv_enable
   *
   * This function makes iucv ready for use. It allocates the pathid
   * table, declares an iucv interrupt buffer and enables the iucv
   * interrupts. Called when the first user has registered an iucv
   * handler.
   */
  static int iucv_enable(void)
  {
  	size_t alloc_size;
  	int cpu, rc;

  	get_online_cpus();

  	rc = -ENOMEM;
  	alloc_size = iucv_max_pathid * sizeof(struct iucv_path);
  	iucv_path_table = kzalloc(alloc_size, GFP_KERNEL);
  	if (!iucv_path_table)
  		goto out;
  	/* Declare per cpu buffers. */
  	rc = -EIO;
  	for_each_online_cpu(cpu)

  		smp_call_function_single(cpu, iucv_declare_cpu, NULL, 1);

  	if (cpumask_empty(&iucv_buffer_cpumask))

  		/* No cpu could declare an iucv buffer. */

  		goto out;

  	put_online_cpus();

  	return 0;

  out:

  	kfree(iucv_path_table);
  	iucv_path_table = NULL;
  	put_online_cpus();

  	return rc;
  }
  
  /**
   * iucv_disable
   *
   * This function shuts down iucv. It disables iucv interrupts, retrieves
   * the iucv interrupt buffer and frees the pathid table. Called after the
   * last user unregister its iucv handler.
   */
  static void iucv_disable(void)
  {

  	get_online_cpus();

  	on_each_cpu(iucv_retrieve_cpu, NULL, 1);

  	kfree(iucv_path_table);

  	iucv_path_table = NULL;
  	put_online_cpus();

  }

  static int __cpuinit iucv_cpu_notify(struct notifier_block *self,
  				     unsigned long action, void *hcpu)
  {
  	cpumask_t cpumask;
  	long cpu = (long) hcpu;
  
  	switch (action) {
  	case CPU_UP_PREPARE:

  	case CPU_UP_PREPARE_FROZEN:

  		iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
  					GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
  		if (!iucv_irq_data[cpu])

  			return notifier_from_errno(-ENOMEM);

  		iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
  				     GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));

  		if (!iucv_param[cpu]) {
  			kfree(iucv_irq_data[cpu]);
  			iucv_irq_data[cpu] = NULL;

  			return notifier_from_errno(-ENOMEM);

  		}

  		iucv_param_irq[cpu] = kmalloc_node(sizeof(union iucv_param),
  					GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
  		if (!iucv_param_irq[cpu]) {
  			kfree(iucv_param[cpu]);
  			iucv_param[cpu] = NULL;
  			kfree(iucv_irq_data[cpu]);
  			iucv_irq_data[cpu] = NULL;

  			return notifier_from_errno(-ENOMEM);

  		}

  		break;
  	case CPU_UP_CANCELED:

  	case CPU_UP_CANCELED_FROZEN:

  	case CPU_DEAD:

  	case CPU_DEAD_FROZEN:

  		kfree(iucv_param_irq[cpu]);
  		iucv_param_irq[cpu] = NULL;

  		kfree(iucv_param[cpu]);
  		iucv_param[cpu] = NULL;
  		kfree(iucv_irq_data[cpu]);
  		iucv_irq_data[cpu] = NULL;

  		break;
  	case CPU_ONLINE:

  	case CPU_ONLINE_FROZEN:

  	case CPU_DOWN_FAILED:

  	case CPU_DOWN_FAILED_FROZEN:

  		if (!iucv_path_table)
  			break;

  		smp_call_function_single(cpu, iucv_declare_cpu, NULL, 1);

  		break;
  	case CPU_DOWN_PREPARE:

  	case CPU_DOWN_PREPARE_FROZEN:

  		if (!iucv_path_table)
  			break;

  		cpumask_copy(&cpumask, &iucv_buffer_cpumask);
  		cpumask_clear_cpu(cpu, &cpumask);
  		if (cpumask_empty(&cpumask))

  			/* Can't offline last IUCV enabled cpu. */

  			return notifier_from_errno(-EINVAL);

  		smp_call_function_single(cpu, iucv_retrieve_cpu, NULL, 1);

  		if (cpumask_empty(&iucv_irq_cpumask))
  			smp_call_function_single(
  				cpumask_first(&iucv_buffer_cpumask),
  				iucv_allow_cpu, NULL, 1);

  		break;
  	}
  	return NOTIFY_OK;
  }

  static struct notifier_block __refdata iucv_cpu_notifier = {

  	.notifier_call = iucv_cpu_notify,
  };

  
  /**
   * iucv_sever_pathid
   * @pathid: path identification number.
   * @userdata: 16-bytes of user data.
   *
   * Sever an iucv path to free up the pathid. Used internally.
   */
  static int iucv_sever_pathid(u16 pathid, u8 userdata[16])
  {
  	union iucv_param *parm;

  	parm = iucv_param_irq[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	if (userdata)
  		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
  	parm->ctrl.ippathid = pathid;
  	return iucv_call_b2f0(IUCV_SEVER, parm);
  }
  
  /**

   * __iucv_cleanup_queue

   * @dummy: unused dummy argument
   *
   * Nop function called via smp_call_function to force work items from
   * pending external iucv interrupts to the work queue.
   */

  static void __iucv_cleanup_queue(void *dummy)

  {
  }
  
  /**

   * iucv_cleanup_queue

   *
   * Function called after a path has been severed to find all remaining
   * work items for the now stale pathid. The caller needs to hold the
   * iucv_table_lock.
   */

  static void iucv_cleanup_queue(void)

  {

  	struct iucv_irq_list *p, *n;

  
  	/*

  	 * When a path is severed, the pathid can be reused immediately

  	 * on a iucv connect or a connection pending interrupt. Remove
  	 * all entries from the task queue that refer to a stale pathid
  	 * (iucv_path_table[ix] == NULL). Only then do the iucv connect
  	 * or deliver the connection pending interrupt. To get all the
  	 * pending interrupts force them to the work queue by calling
  	 * an empty function on all cpus.

  	 */

  	smp_call_function(__iucv_cleanup_queue, NULL, 1);

  	spin_lock_irq(&iucv_queue_lock);
  	list_for_each_entry_safe(p, n, &iucv_task_queue, list) {
  		/* Remove stale work items from the task queue. */
  		if (iucv_path_table[p->data.ippathid] == NULL) {

  			list_del(&p->list);
  			kfree(p);
  		}
  	}

  	spin_unlock_irq(&iucv_queue_lock);

  }
  
  /**
   * iucv_register:
   * @handler: address of iucv handler structure
   * @smp: != 0 indicates that the handler can deal with out of order messages
   *
   * Registers a driver with IUCV.
   *
   * Returns 0 on success, -ENOMEM if the memory allocation for the pathid
   * table failed, or -EIO if IUCV_DECLARE_BUFFER failed on all cpus.
   */
  int iucv_register(struct iucv_handler *handler, int smp)
  {
  	int rc;
  
  	if (!iucv_available)
  		return -ENOSYS;
  	mutex_lock(&iucv_register_mutex);
  	if (!smp)
  		iucv_nonsmp_handler++;
  	if (list_empty(&iucv_handler_list)) {
  		rc = iucv_enable();
  		if (rc)
  			goto out_mutex;
  	} else if (!smp && iucv_nonsmp_handler == 1)
  		iucv_setmask_up();
  	INIT_LIST_HEAD(&handler->paths);

  	spin_lock_bh(&iucv_table_lock);

  	list_add_tail(&handler->list, &iucv_handler_list);

  	spin_unlock_bh(&iucv_table_lock);

  	rc = 0;
  out_mutex:
  	mutex_unlock(&iucv_register_mutex);
  	return rc;
  }

  EXPORT_SYMBOL(iucv_register);

  
  /**
   * iucv_unregister
   * @handler:  address of iucv handler structure
   * @smp: != 0 indicates that the handler can deal with out of order messages
   *
   * Unregister driver from IUCV.
   */
  void iucv_unregister(struct iucv_handler *handler, int smp)
  {
  	struct iucv_path *p, *n;
  
  	mutex_lock(&iucv_register_mutex);
  	spin_lock_bh(&iucv_table_lock);
  	/* Remove handler from the iucv_handler_list. */
  	list_del_init(&handler->list);

  	/* Sever all pathids still referring to the handler. */

  	list_for_each_entry_safe(p, n, &handler->paths, list) {
  		iucv_sever_pathid(p->pathid, NULL);
  		iucv_path_table[p->pathid] = NULL;
  		list_del(&p->list);

  		iucv_path_free(p);
  	}
  	spin_unlock_bh(&iucv_table_lock);
  	if (!smp)
  		iucv_nonsmp_handler--;
  	if (list_empty(&iucv_handler_list))
  		iucv_disable();
  	else if (!smp && iucv_nonsmp_handler == 0)
  		iucv_setmask_mp();
  	mutex_unlock(&iucv_register_mutex);
  }

  EXPORT_SYMBOL(iucv_unregister);

  static int iucv_reboot_event(struct notifier_block *this,
  			     unsigned long event, void *ptr)
  {

  	int i;

  
  	get_online_cpus();
  	on_each_cpu(iucv_block_cpu, NULL, 1);
  	preempt_disable();
  	for (i = 0; i < iucv_max_pathid; i++) {
  		if (iucv_path_table[i])

  			iucv_sever_pathid(i, NULL);

  	}
  	preempt_enable();
  	put_online_cpus();
  	iucv_disable();
  	return NOTIFY_DONE;
  }
  
  static struct notifier_block iucv_reboot_notifier = {
  	.notifier_call = iucv_reboot_event,
  };

  /**
   * iucv_path_accept
   * @path: address of iucv path structure
   * @handler: address of iucv handler structure
   * @userdata: 16 bytes of data reflected to the communication partner
   * @private: private data passed to interrupt handlers for this path
   *
   * This function is issued after the user received a connection pending
   * external interrupt and now wishes to complete the IUCV communication path.
   *
   * Returns the result of the CP IUCV call.
   */
  int iucv_path_accept(struct iucv_path *path, struct iucv_handler *handler,
  		     u8 userdata[16], void *private)
  {
  	union iucv_param *parm;
  	int rc;
  
  	local_bh_disable();

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	/* Prepare parameter block. */

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	parm->ctrl.ippathid = path->pathid;
  	parm->ctrl.ipmsglim = path->msglim;
  	if (userdata)
  		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
  	parm->ctrl.ipflags1 = path->flags;
  
  	rc = iucv_call_b2f0(IUCV_ACCEPT, parm);
  	if (!rc) {
  		path->private = private;
  		path->msglim = parm->ctrl.ipmsglim;
  		path->flags = parm->ctrl.ipflags1;
  	}

  out:

  	local_bh_enable();
  	return rc;
  }

  EXPORT_SYMBOL(iucv_path_accept);

  
  /**
   * iucv_path_connect
   * @path: address of iucv path structure
   * @handler: address of iucv handler structure
   * @userid: 8-byte user identification
   * @system: 8-byte target system identification
   * @userdata: 16 bytes of data reflected to the communication partner
   * @private: private data passed to interrupt handlers for this path
   *
   * This function establishes an IUCV path. Although the connect may complete
   * successfully, you are not able to use the path until you receive an IUCV
   * Connection Complete external interrupt.
   *
   * Returns the result of the CP IUCV call.
   */
  int iucv_path_connect(struct iucv_path *path, struct iucv_handler *handler,
  		      u8 userid[8], u8 system[8], u8 userdata[16],
  		      void *private)
  {
  	union iucv_param *parm;
  	int rc;

  	spin_lock_bh(&iucv_table_lock);
  	iucv_cleanup_queue();

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	parm->ctrl.ipmsglim = path->msglim;
  	parm->ctrl.ipflags1 = path->flags;
  	if (userid) {
  		memcpy(parm->ctrl.ipvmid, userid, sizeof(parm->ctrl.ipvmid));
  		ASCEBC(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
  		EBC_TOUPPER(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
  	}
  	if (system) {
  		memcpy(parm->ctrl.iptarget, system,
  		       sizeof(parm->ctrl.iptarget));
  		ASCEBC(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
  		EBC_TOUPPER(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
  	}
  	if (userdata)
  		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
  
  	rc = iucv_call_b2f0(IUCV_CONNECT, parm);
  	if (!rc) {
  		if (parm->ctrl.ippathid < iucv_max_pathid) {
  			path->pathid = parm->ctrl.ippathid;
  			path->msglim = parm->ctrl.ipmsglim;
  			path->flags = parm->ctrl.ipflags1;
  			path->handler = handler;
  			path->private = private;
  			list_add_tail(&path->list, &handler->paths);
  			iucv_path_table[path->pathid] = path;
  		} else {
  			iucv_sever_pathid(parm->ctrl.ippathid,
  					  iucv_error_pathid);
  			rc = -EIO;
  		}
  	}

  out:

  	spin_unlock_bh(&iucv_table_lock);

  	return rc;
  }

  EXPORT_SYMBOL(iucv_path_connect);

  
  /**
   * iucv_path_quiesce:
   * @path: address of iucv path structure
   * @userdata: 16 bytes of data reflected to the communication partner
   *
   * This function temporarily suspends incoming messages on an IUCV path.
   * You can later reactivate the path by invoking the iucv_resume function.
   *
   * Returns the result from the CP IUCV call.
   */
  int iucv_path_quiesce(struct iucv_path *path, u8 userdata[16])
  {
  	union iucv_param *parm;
  	int rc;
  
  	local_bh_disable();

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	if (userdata)
  		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
  	parm->ctrl.ippathid = path->pathid;
  	rc = iucv_call_b2f0(IUCV_QUIESCE, parm);

  out:

  	local_bh_enable();
  	return rc;
  }

  EXPORT_SYMBOL(iucv_path_quiesce);

  
  /**
   * iucv_path_resume:
   * @path: address of iucv path structure
   * @userdata: 16 bytes of data reflected to the communication partner
   *
   * This function resumes incoming messages on an IUCV path that has
   * been stopped with iucv_path_quiesce.
   *
   * Returns the result from the CP IUCV call.
   */
  int iucv_path_resume(struct iucv_path *path, u8 userdata[16])
  {
  	union iucv_param *parm;
  	int rc;
  
  	local_bh_disable();

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	if (userdata)
  		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
  	parm->ctrl.ippathid = path->pathid;
  	rc = iucv_call_b2f0(IUCV_RESUME, parm);

  out:

  	local_bh_enable();
  	return rc;
  }
  
  /**
   * iucv_path_sever
   * @path: address of iucv path structure
   * @userdata: 16 bytes of data reflected to the communication partner
   *
   * This function terminates an IUCV path.
   *
   * Returns the result from the CP IUCV call.
   */
  int iucv_path_sever(struct iucv_path *path, u8 userdata[16])
  {
  	int rc;

  	preempt_disable();

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	if (iucv_active_cpu != smp_processor_id())

  		spin_lock_bh(&iucv_table_lock);
  	rc = iucv_sever_pathid(path->pathid, userdata);

  	iucv_path_table[path->pathid] = NULL;
  	list_del_init(&path->list);

  	if (iucv_active_cpu != smp_processor_id())

  		spin_unlock_bh(&iucv_table_lock);

  out:

  	preempt_enable();
  	return rc;
  }

  EXPORT_SYMBOL(iucv_path_sever);

  
  /**
   * iucv_message_purge
   * @path: address of iucv path structure
   * @msg: address of iucv msg structure
   * @srccls: source class of message
   *
   * Cancels a message you have sent.
   *
   * Returns the result from the CP IUCV call.
   */
  int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg,
  		       u32 srccls)
  {
  	union iucv_param *parm;
  	int rc;
  
  	local_bh_disable();

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	parm->purge.ippathid = path->pathid;
  	parm->purge.ipmsgid = msg->id;
  	parm->purge.ipsrccls = srccls;
  	parm->purge.ipflags1 = IUCV_IPSRCCLS | IUCV_IPFGMID | IUCV_IPFGPID;
  	rc = iucv_call_b2f0(IUCV_PURGE, parm);
  	if (!rc) {
  		msg->audit = (*(u32 *) &parm->purge.ipaudit) >> 8;
  		msg->tag = parm->purge.ipmsgtag;
  	}

  out:

  	local_bh_enable();
  	return rc;
  }

  EXPORT_SYMBOL(iucv_message_purge);

  
  /**

   * iucv_message_receive_iprmdata
   * @path: address of iucv path structure
   * @msg: address of iucv msg structure
   * @flags: how the message is received (IUCV_IPBUFLST)
   * @buffer: address of data buffer or address of struct iucv_array
   * @size: length of data buffer
   * @residual:
   *
   * Internal function used by iucv_message_receive and __iucv_message_receive
   * to receive RMDATA data stored in struct iucv_message.
   */
  static int iucv_message_receive_iprmdata(struct iucv_path *path,
  					 struct iucv_message *msg,
  					 u8 flags, void *buffer,
  					 size_t size, size_t *residual)
  {
  	struct iucv_array *array;
  	u8 *rmmsg;
  	size_t copy;
  
  	/*
  	 * Message is 8 bytes long and has been stored to the
  	 * message descriptor itself.
  	 */
  	if (residual)
  		*residual = abs(size - 8);
  	rmmsg = msg->rmmsg;
  	if (flags & IUCV_IPBUFLST) {
  		/* Copy to struct iucv_array. */
  		size = (size < 8) ? size : 8;
  		for (array = buffer; size > 0; array++) {
  			copy = min_t(size_t, size, array->length);
  			memcpy((u8 *)(addr_t) array->address,
  				rmmsg, copy);
  			rmmsg += copy;
  			size -= copy;
  		}
  	} else {
  		/* Copy to direct buffer. */
  		memcpy(buffer, rmmsg, min_t(size_t, size, 8));
  	}
  	return 0;
  }
  
  /**
   * __iucv_message_receive

   * @path: address of iucv path structure
   * @msg: address of iucv msg structure
   * @flags: how the message is received (IUCV_IPBUFLST)
   * @buffer: address of data buffer or address of struct iucv_array
   * @size: length of data buffer
   * @residual:
   *
   * This function receives messages that are being sent to you over
   * established paths. This function will deal with RMDATA messages
   * embedded in struct iucv_message as well.
   *

   * Locking:	no locking
   *

   * Returns the result from the CP IUCV call.
   */

  int __iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
  			   u8 flags, void *buffer, size_t size, size_t *residual)

  {
  	union iucv_param *parm;

  	int rc;

  	if (msg->flags & IUCV_IPRMDATA)
  		return iucv_message_receive_iprmdata(path, msg, flags,
  						     buffer, size, residual);

  	 if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	parm->db.ipbfadr1 = (u32)(addr_t) buffer;
  	parm->db.ipbfln1f = (u32) size;
  	parm->db.ipmsgid = msg->id;
  	parm->db.ippathid = path->pathid;
  	parm->db.iptrgcls = msg->class;
  	parm->db.ipflags1 = (flags | IUCV_IPFGPID |
  			     IUCV_IPFGMID | IUCV_IPTRGCLS);
  	rc = iucv_call_b2f0(IUCV_RECEIVE, parm);
  	if (!rc || rc == 5) {
  		msg->flags = parm->db.ipflags1;
  		if (residual)
  			*residual = parm->db.ipbfln1f;
  	}

  out:

  	return rc;
  }
  EXPORT_SYMBOL(__iucv_message_receive);
  
  /**
   * iucv_message_receive
   * @path: address of iucv path structure
   * @msg: address of iucv msg structure
   * @flags: how the message is received (IUCV_IPBUFLST)
   * @buffer: address of data buffer or address of struct iucv_array
   * @size: length of data buffer
   * @residual:
   *
   * This function receives messages that are being sent to you over
   * established paths. This function will deal with RMDATA messages
   * embedded in struct iucv_message as well.
   *
   * Locking:	local_bh_enable/local_bh_disable
   *
   * Returns the result from the CP IUCV call.
   */
  int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
  			 u8 flags, void *buffer, size_t size, size_t *residual)
  {
  	int rc;
  
  	if (msg->flags & IUCV_IPRMDATA)
  		return iucv_message_receive_iprmdata(path, msg, flags,
  						     buffer, size, residual);
  	local_bh_disable();
  	rc = __iucv_message_receive(path, msg, flags, buffer, size, residual);

  	local_bh_enable();
  	return rc;
  }

  EXPORT_SYMBOL(iucv_message_receive);

  
  /**
   * iucv_message_reject
   * @path: address of iucv path structure
   * @msg: address of iucv msg structure
   *
   * The reject function refuses a specified message. Between the time you
   * are notified of a message and the time that you complete the message,
   * the message may be rejected.
   *
   * Returns the result from the CP IUCV call.
   */
  int iucv_message_reject(struct iucv_path *path, struct iucv_message *msg)
  {
  	union iucv_param *parm;
  	int rc;
  
  	local_bh_disable();

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	parm->db.ippathid = path->pathid;
  	parm->db.ipmsgid = msg->id;
  	parm->db.iptrgcls = msg->class;
  	parm->db.ipflags1 = (IUCV_IPTRGCLS | IUCV_IPFGMID | IUCV_IPFGPID);
  	rc = iucv_call_b2f0(IUCV_REJECT, parm);

  out:

  	local_bh_enable();
  	return rc;
  }

  EXPORT_SYMBOL(iucv_message_reject);

  
  /**
   * iucv_message_reply
   * @path: address of iucv path structure
   * @msg: address of iucv msg structure
   * @flags: how the reply is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
   * @reply: address of reply data buffer or address of struct iucv_array
   * @size: length of reply data buffer
   *
   * This function responds to the two-way messages that you receive. You
   * must identify completely the message to which you wish to reply. ie,
   * pathid, msgid, and trgcls. Prmmsg signifies the data is moved into
   * the parameter list.
   *
   * Returns the result from the CP IUCV call.
   */
  int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg,
  		       u8 flags, void *reply, size_t size)
  {
  	union iucv_param *parm;
  	int rc;
  
  	local_bh_disable();

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	if (flags & IUCV_IPRMDATA) {
  		parm->dpl.ippathid = path->pathid;
  		parm->dpl.ipflags1 = flags;
  		parm->dpl.ipmsgid = msg->id;
  		parm->dpl.iptrgcls = msg->class;
  		memcpy(parm->dpl.iprmmsg, reply, min_t(size_t, size, 8));
  	} else {
  		parm->db.ipbfadr1 = (u32)(addr_t) reply;
  		parm->db.ipbfln1f = (u32) size;
  		parm->db.ippathid = path->pathid;
  		parm->db.ipflags1 = flags;
  		parm->db.ipmsgid = msg->id;
  		parm->db.iptrgcls = msg->class;
  	}
  	rc = iucv_call_b2f0(IUCV_REPLY, parm);

  out:

  	local_bh_enable();
  	return rc;
  }

  EXPORT_SYMBOL(iucv_message_reply);

  
  /**

   * __iucv_message_send

   * @path: address of iucv path structure
   * @msg: address of iucv msg structure
   * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
   * @srccls: source class of message
   * @buffer: address of send buffer or address of struct iucv_array
   * @size: length of send buffer
   *
   * This function transmits data to another application. Data to be
   * transmitted is in a buffer and this is a one-way message and the
   * receiver will not reply to the message.
   *

   * Locking:	no locking
   *

   * Returns the result from the CP IUCV call.
   */

  int __iucv_message_send(struct iucv_path *path, struct iucv_message *msg,

  		      u8 flags, u32 srccls, void *buffer, size_t size)
  {
  	union iucv_param *parm;
  	int rc;

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	if (flags & IUCV_IPRMDATA) {
  		/* Message of 8 bytes can be placed into the parameter list. */
  		parm->dpl.ippathid = path->pathid;
  		parm->dpl.ipflags1 = flags | IUCV_IPNORPY;
  		parm->dpl.iptrgcls = msg->class;
  		parm->dpl.ipsrccls = srccls;
  		parm->dpl.ipmsgtag = msg->tag;
  		memcpy(parm->dpl.iprmmsg, buffer, 8);
  	} else {
  		parm->db.ipbfadr1 = (u32)(addr_t) buffer;
  		parm->db.ipbfln1f = (u32) size;
  		parm->db.ippathid = path->pathid;
  		parm->db.ipflags1 = flags | IUCV_IPNORPY;
  		parm->db.iptrgcls = msg->class;
  		parm->db.ipsrccls = srccls;
  		parm->db.ipmsgtag = msg->tag;
  	}
  	rc = iucv_call_b2f0(IUCV_SEND, parm);
  	if (!rc)
  		msg->id = parm->db.ipmsgid;

  out:

  	return rc;
  }
  EXPORT_SYMBOL(__iucv_message_send);
  
  /**
   * iucv_message_send
   * @path: address of iucv path structure
   * @msg: address of iucv msg structure
   * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
   * @srccls: source class of message
   * @buffer: address of send buffer or address of struct iucv_array
   * @size: length of send buffer
   *
   * This function transmits data to another application. Data to be
   * transmitted is in a buffer and this is a one-way message and the
   * receiver will not reply to the message.
   *
   * Locking:	local_bh_enable/local_bh_disable
   *
   * Returns the result from the CP IUCV call.
   */
  int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
  		      u8 flags, u32 srccls, void *buffer, size_t size)
  {
  	int rc;
  
  	local_bh_disable();
  	rc = __iucv_message_send(path, msg, flags, srccls, buffer, size);

  	local_bh_enable();
  	return rc;
  }

  EXPORT_SYMBOL(iucv_message_send);

  
  /**
   * iucv_message_send2way
   * @path: address of iucv path structure
   * @msg: address of iucv msg structure
   * @flags: how the message is sent and the reply is received
   *	   (IUCV_IPRMDATA, IUCV_IPBUFLST, IUCV_IPPRTY, IUCV_ANSLST)
   * @srccls: source class of message
   * @buffer: address of send buffer or address of struct iucv_array
   * @size: length of send buffer
   * @ansbuf: address of answer buffer or address of struct iucv_array
   * @asize: size of reply buffer
   *
   * This function transmits data to another application. Data to be
   * transmitted is in a buffer. The receiver of the send is expected to
   * reply to the message and a buffer is provided into which IUCV moves
   * the reply to this message.
   *
   * Returns the result from the CP IUCV call.
   */
  int iucv_message_send2way(struct iucv_path *path, struct iucv_message *msg,
  			  u8 flags, u32 srccls, void *buffer, size_t size,
  			  void *answer, size_t asize, size_t *residual)
  {
  	union iucv_param *parm;
  	int rc;
  
  	local_bh_disable();

  	if (cpumask_empty(&iucv_buffer_cpumask)) {

  		rc = -EIO;
  		goto out;
  	}

  	parm = iucv_param[smp_processor_id()];

  	memset(parm, 0, sizeof(union iucv_param));
  	if (flags & IUCV_IPRMDATA) {
  		parm->dpl.ippathid = path->pathid;
  		parm->dpl.ipflags1 = path->flags;	/* priority message */
  		parm->dpl.iptrgcls = msg->class;
  		parm->dpl.ipsrccls = srccls;
  		parm->dpl.ipmsgtag = msg->tag;
  		parm->dpl.ipbfadr2 = (u32)(addr_t) answer;
  		parm->dpl.ipbfln2f = (u32) asize;
  		memcpy(parm->dpl.iprmmsg, buffer, 8);
  	} else {
  		parm->db.ippathid = path->pathid;
  		parm->db.ipflags1 = path->flags;	/* priority message */
  		parm->db.iptrgcls = msg->class;
  		parm->db.ipsrccls = srccls;
  		parm->db.ipmsgtag = msg->tag;
  		parm->db.ipbfadr1 = (u32)(addr_t) buffer;
  		parm->db.ipbfln1f = (u32) size;
  		parm->db.ipbfadr2 = (u32)(addr_t) answer;
  		parm->db.ipbfln2f = (u32) asize;
  	}
  	rc = iucv_call_b2f0(IUCV_SEND, parm);
  	if (!rc)
  		msg->id = parm->db.ipmsgid;

  out:

  	local_bh_enable();
  	return rc;
  }

  EXPORT_SYMBOL(iucv_message_send2way);

  
  /**
   * iucv_path_pending
   * @data: Pointer to external interrupt buffer
   *
   * Process connection pending work item. Called from tasklet while holding
   * iucv_table_lock.
   */
  struct iucv_path_pending {
  	u16 ippathid;
  	u8  ipflags1;
  	u8  iptype;
  	u16 ipmsglim;
  	u16 res1;
  	u8  ipvmid[8];
  	u8  ipuser[16];
  	u32 res3;
  	u8  ippollfg;
  	u8  res4[3];

  } __packed;

  
  static void iucv_path_pending(struct iucv_irq_data *data)
  {
  	struct iucv_path_pending *ipp = (void *) data;
  	struct iucv_handler *handler;
  	struct iucv_path *path;
  	char *error;
  
  	BUG_ON(iucv_path_table[ipp->ippathid]);
  	/* New pathid, handler found. Create a new path struct. */
  	error = iucv_error_no_memory;
  	path = iucv_path_alloc(ipp->ipmsglim, ipp->ipflags1, GFP_ATOMIC);
  	if (!path)
  		goto out_sever;
  	path->pathid = ipp->ippathid;
  	iucv_path_table[path->pathid] = path;
  	EBCASC(ipp->ipvmid, 8);
  
  	/* Call registered handler until one is found that wants the path. */
  	list_for_each_entry(handler, &iucv_handler_list, list) {
  		if (!handler->path_pending)
  			continue;
  		/*
  		 * Add path to handler to allow a call to iucv_path_sever
  		 * inside the path_pending function. If the handler returns
  		 * an error remove the path from the handler again.
  		 */
  		list_add(&path->list, &handler->paths);
  		path->handler = handler;
  		if (!handler->path_pending(path, ipp->ipvmid, ipp->ipuser))
  			return;
  		list_del(&path->list);
  		path->handler = NULL;
  	}
  	/* No handler wanted the path. */
  	iucv_path_table[path->pathid] = NULL;
  	iucv_path_free(path);
  	error = iucv_error_no_listener;
  out_sever:
  	iucv_sever_pathid(ipp->ippathid, error);
  }
  
  /**
   * iucv_path_complete
   * @data: Pointer to external interrupt buffer
   *
   * Process connection complete work item. Called from tasklet while holding
   * iucv_table_lock.
   */
  struct iucv_path_complete {
  	u16 ippathid;
  	u8  ipflags1;
  	u8  iptype;
  	u16 ipmsglim;
  	u16 res1;
  	u8  res2[8];
  	u8  ipuser[16];
  	u32 res3;
  	u8  ippollfg;
  	u8  res4[3];

  } __packed;

  
  static void iucv_path_complete(struct iucv_irq_data *data)
  {
  	struct iucv_path_complete *ipc = (void *) data;
  	struct iucv_path *path = iucv_path_table[ipc->ippathid];

  	if (path)
  		path->flags = ipc->ipflags1;

  	if (path && path->handler && path->handler->path_complete)

  		path->handler->path_complete(path, ipc->ipuser);
  }
  
  /**
   * iucv_path_severed
   * @data: Pointer to external interrupt buffer
   *
   * Process connection severed work item. Called from tasklet while holding
   * iucv_table_lock.
   */
  struct iucv_path_severed {
  	u16 ippathid;
  	u8  res1;
  	u8  iptype;
  	u32 res2;
  	u8  res3[8];
  	u8  ipuser[16];
  	u32 res4;
  	u8  ippollfg;
  	u8  res5[3];

  } __packed;

  
  static void iucv_path_severed(struct iucv_irq_data *data)
  {
  	struct iucv_path_severed *ips = (void *) data;
  	struct iucv_path *path = iucv_path_table[ips->ippathid];

  	if (!path || !path->handler)	/* Already severed */
  		return;

  	if (path->handler->path_severed)
  		path->handler->path_severed(path, ips->ipuser);
  	else {
  		iucv_sever_pathid(path->pathid, NULL);
  		iucv_path_table[path->pathid] = NULL;

  		list_del(&path->list);

  		iucv_path_free(path);
  	}
  }
  
  /**
   * iucv_path_quiesced
   * @data: Pointer to external interrupt buffer
   *
   * Process connection quiesced work item. Called from tasklet while holding
   * iucv_table_lock.
   */
  struct iucv_path_quiesced {
  	u16 ippathid;
  	u8  res1;
  	u8  iptype;
  	u32 res2;
  	u8  res3[8];
  	u8  ipuser[16];
  	u32 res4;
  	u8  ippollfg;
  	u8  res5[3];

  } __packed;

  
  static void iucv_path_quiesced(struct iucv_irq_data *data)
  {
  	struct iucv_path_quiesced *ipq = (void *) data;
  	struct iucv_path *path = iucv_path_table[ipq->ippathid];

  	if (path && path->handler && path->handler->path_quiesced)

  		path->handler->path_quiesced(path, ipq->ipuser);
  }
  
  /**
   * iucv_path_resumed
   * @data: Pointer to external interrupt buffer
   *
   * Process connection resumed work item. Called from tasklet while holding
   * iucv_table_lock.
   */
  struct iucv_path_resumed {
  	u16 ippathid;
  	u8  res1;
  	u8  iptype;
  	u32 res2;
  	u8  res3[8];
  	u8  ipuser[16];
  	u32 res4;
  	u8  ippollfg;
  	u8  res5[3];

  } __packed;

  
  static void iucv_path_resumed(struct iucv_irq_data *data)
  {
  	struct iucv_path_resumed *ipr = (void *) data;
  	struct iucv_path *path = iucv_path_table[ipr->ippathid];

  	if (path && path->handler && path->handler->path_resumed)

  		path->handler->path_resumed(path, ipr->ipuser);
  }
  
  /**
   * iucv_message_complete
   * @data: Pointer to external interrupt buffer
   *
   * Process message complete work item. Called from tasklet while holding
   * iucv_table_lock.
   */
  struct iucv_message_complete {
  	u16 ippathid;
  	u8  ipflags1;
  	u8  iptype;
  	u32 ipmsgid;
  	u32 ipaudit;
  	u8  iprmmsg[8];
  	u32 ipsrccls;
  	u32 ipmsgtag;
  	u32 res;
  	u32 ipbfln2f;
  	u8  ippollfg;
  	u8  res2[3];

  } __packed;

  
  static void iucv_message_complete(struct iucv_irq_data *data)
  {
  	struct iucv_message_complete *imc = (void *) data;
  	struct iucv_path *path = iucv_path_table[imc->ippathid];
  	struct iucv_message msg;

  	if (path && path->handler && path->handler->message_complete) {

  		msg.flags = imc->ipflags1;
  		msg.id = imc->ipmsgid;
  		msg.audit = imc->ipaudit;
  		memcpy(msg.rmmsg, imc->iprmmsg, 8);
  		msg.class = imc->ipsrccls;
  		msg.tag = imc->ipmsgtag;
  		msg.length = imc->ipbfln2f;
  		path->handler->message_complete(path, &msg);
  	}
  }
  
  /**
   * iucv_message_pending
   * @data: Pointer to external interrupt buffer
   *
   * Process message pending work item. Called from tasklet while holding
   * iucv_table_lock.
   */
  struct iucv_message_pending {
  	u16 ippathid;
  	u8  ipflags1;
  	u8  iptype;
  	u32 ipmsgid;
  	u32 iptrgcls;
  	union {
  		u32 iprmmsg1_u32;
  		u8  iprmmsg1[4];
  	} ln1msg1;
  	union {
  		u32 ipbfln1f;
  		u8  iprmmsg2[4];
  	} ln1msg2;
  	u32 res1[3];
  	u32 ipbfln2f;
  	u8  ippollfg;
  	u8  res2[3];

  } __packed;

  
  static void iucv_message_pending(struct iucv_irq_data *data)
  {
  	struct iucv_message_pending *imp = (void *) data;
  	struct iucv_path *path = iucv_path_table[imp->ippathid];
  	struct iucv_message msg;

  	if (path && path->handler && path->handler->message_pending) {

  		msg.flags = imp->ipflags1;
  		msg.id = imp->ipmsgid;
  		msg.class = imp->iptrgcls;
  		if (imp->ipflags1 & IUCV_IPRMDATA) {
  			memcpy(msg.rmmsg, imp->ln1msg1.iprmmsg1, 8);
  			msg.length = 8;
  		} else
  			msg.length = imp->ln1msg2.ipbfln1f;
  		msg.reply_size = imp->ipbfln2f;
  		path->handler->message_pending(path, &msg);
  	}
  }
  
  /**

   * iucv_tasklet_fn:

   *
   * This tasklet loops over the queue of irq buffers created by
   * iucv_external_interrupt, calls the appropriate action handler
   * and then frees the buffer.
   */

  static void iucv_tasklet_fn(unsigned long ignored)

  {
  	typedef void iucv_irq_fn(struct iucv_irq_data *);
  	static iucv_irq_fn *irq_fn[] = {

  		[0x02] = iucv_path_complete,
  		[0x03] = iucv_path_severed,
  		[0x04] = iucv_path_quiesced,
  		[0x05] = iucv_path_resumed,
  		[0x06] = iucv_message_complete,
  		[0x07] = iucv_message_complete,
  		[0x08] = iucv_message_pending,
  		[0x09] = iucv_message_pending,
  	};

  	LIST_HEAD(task_queue);

  	struct iucv_irq_list *p, *n;

  
  	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */

  	if (!spin_trylock(&iucv_table_lock)) {
  		tasklet_schedule(&iucv_tasklet);
  		return;
  	}

  	iucv_active_cpu = smp_processor_id();

  	spin_lock_irq(&iucv_queue_lock);
  	list_splice_init(&iucv_task_queue, &task_queue);
  	spin_unlock_irq(&iucv_queue_lock);
  
  	list_for_each_entry_safe(p, n, &task_queue, list) {

  		list_del_init(&p->list);

  		irq_fn[p->data.iptype](&p->data);
  		kfree(p);

  	}

  	iucv_active_cpu = -1;

  	spin_unlock(&iucv_table_lock);
  }
  
  /**

   * iucv_work_fn:
   *
   * This work function loops over the queue of path pending irq blocks
   * created by iucv_external_interrupt, calls the appropriate action
   * handler and then frees the buffer.
   */
  static void iucv_work_fn(struct work_struct *work)
  {

  	LIST_HEAD(work_queue);

  	struct iucv_irq_list *p, *n;
  
  	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */
  	spin_lock_bh(&iucv_table_lock);
  	iucv_active_cpu = smp_processor_id();
  
  	spin_lock_irq(&iucv_queue_lock);
  	list_splice_init(&iucv_work_queue, &work_queue);
  	spin_unlock_irq(&iucv_queue_lock);
  
  	iucv_cleanup_queue();
  	list_for_each_entry_safe(p, n, &work_queue, list) {
  		list_del_init(&p->list);
  		iucv_path_pending(&p->data);
  		kfree(p);
  	}
  
  	iucv_active_cpu = -1;
  	spin_unlock_bh(&iucv_table_lock);
  }
  
  /**

   * iucv_external_interrupt
   * @code: irq code
   *
   * Handles external interrupts coming in from CP.

   * Places the interrupt buffer on a queue and schedules iucv_tasklet_fn().

   */

  static void iucv_external_interrupt(unsigned int ext_int_code,
  				    unsigned int param32, unsigned long param64)

  {
  	struct iucv_irq_data *p;

  	struct iucv_irq_list *work;

  	kstat_cpu(smp_processor_id()).irqs[EXTINT_IUC]++;

  	p = iucv_irq_data[smp_processor_id()];

  	if (p->ippathid >= iucv_max_pathid) {

  		WARN_ON(p->ippathid >= iucv_max_pathid);

  		iucv_sever_pathid(p->ippathid, iucv_error_no_listener);
  		return;
  	}

  	BUG_ON(p->iptype  < 0x01 || p->iptype > 0x09);

  	work = kmalloc(sizeof(struct iucv_irq_list), GFP_ATOMIC);

  	if (!work) {

  		pr_warning("iucv_external_interrupt: out of memory
  ");

  		return;
  	}
  	memcpy(&work->data, p, sizeof(work->data));

  	spin_lock(&iucv_queue_lock);
  	if (p->iptype == 0x01) {
  		/* Path pending interrupt. */
  		list_add_tail(&work->list, &iucv_work_queue);
  		schedule_work(&iucv_work);
  	} else {
  		/* The other interrupts. */
  		list_add_tail(&work->list, &iucv_task_queue);
  		tasklet_schedule(&iucv_tasklet);
  	}
  	spin_unlock(&iucv_queue_lock);

  }

  static int iucv_pm_prepare(struct device *dev)
  {
  	int rc = 0;
  
  #ifdef CONFIG_PM_DEBUG
  	printk(KERN_INFO "iucv_pm_prepare
  ");
  #endif
  	if (dev->driver && dev->driver->pm && dev->driver->pm->prepare)
  		rc = dev->driver->pm->prepare(dev);
  	return rc;
  }
  
  static void iucv_pm_complete(struct device *dev)
  {
  #ifdef CONFIG_PM_DEBUG
  	printk(KERN_INFO "iucv_pm_complete
  ");
  #endif
  	if (dev->driver && dev->driver->pm && dev->driver->pm->complete)
  		dev->driver->pm->complete(dev);
  }
  
  /**
   * iucv_path_table_empty() - determine if iucv path table is empty
   *
   * Returns 0 if there are still iucv pathes defined
   *	   1 if there are no iucv pathes defined
   */
  int iucv_path_table_empty(void)
  {
  	int i;
  
  	for (i = 0; i < iucv_max_pathid; i++) {
  		if (iucv_path_table[i])
  			return 0;
  	}
  	return 1;
  }
  
  /**
   * iucv_pm_freeze() - Freeze PM callback
   * @dev:	iucv-based device
   *
   * disable iucv interrupts
   * invoke callback function of the iucv-based driver
   * shut down iucv, if no iucv-pathes are established anymore
   */
  static int iucv_pm_freeze(struct device *dev)
  {
  	int cpu;

  	struct iucv_irq_list *p, *n;

  	int rc = 0;
  
  #ifdef CONFIG_PM_DEBUG
  	printk(KERN_WARNING "iucv_pm_freeze
  ");
  #endif

  	if (iucv_pm_state != IUCV_PM_FREEZING) {

  		for_each_cpu(cpu, &iucv_irq_cpumask)

  			smp_call_function_single(cpu, iucv_block_cpu_almost,
  						 NULL, 1);
  		cancel_work_sync(&iucv_work);
  		list_for_each_entry_safe(p, n, &iucv_work_queue, list) {
  			list_del_init(&p->list);
  			iucv_sever_pathid(p->data.ippathid,
  					  iucv_error_no_listener);
  			kfree(p);
  		}
  	}

  	iucv_pm_state = IUCV_PM_FREEZING;

  	if (dev->driver && dev->driver->pm && dev->driver->pm->freeze)
  		rc = dev->driver->pm->freeze(dev);
  	if (iucv_path_table_empty())
  		iucv_disable();
  	return rc;
  }
  
  /**
   * iucv_pm_thaw() - Thaw PM callback
   * @dev:	iucv-based device
   *
   * make iucv ready for use again: allocate path table, declare interrupt buffers
   *				  and enable iucv interrupts
   * invoke callback function of the iucv-based driver
   */
  static int iucv_pm_thaw(struct device *dev)
  {
  	int rc = 0;
  
  #ifdef CONFIG_PM_DEBUG
  	printk(KERN_WARNING "iucv_pm_thaw
  ");
  #endif

  	iucv_pm_state = IUCV_PM_THAWING;

  	if (!iucv_path_table) {
  		rc = iucv_enable();
  		if (rc)
  			goto out;
  	}

  	if (cpumask_empty(&iucv_irq_cpumask)) {

  		if (iucv_nonsmp_handler)
  			/* enable interrupts on one cpu */
  			iucv_allow_cpu(NULL);
  		else
  			/* enable interrupts on all cpus */
  			iucv_setmask_mp();
  	}
  	if (dev->driver && dev->driver->pm && dev->driver->pm->thaw)
  		rc = dev->driver->pm->thaw(dev);
  out:
  	return rc;
  }
  
  /**
   * iucv_pm_restore() - Restore PM callback
   * @dev:	iucv-based device
   *
   * make iucv ready for use again: allocate path table, declare interrupt buffers
   *				  and enable iucv interrupts
   * invoke callback function of the iucv-based driver
   */
  static int iucv_pm_restore(struct device *dev)
  {
  	int rc = 0;
  
  #ifdef CONFIG_PM_DEBUG
  	printk(KERN_WARNING "iucv_pm_restore %p
  ", iucv_path_table);
  #endif

  	if ((iucv_pm_state != IUCV_PM_RESTORING) && iucv_path_table)
  		pr_warning("Suspending Linux did not completely close all IUCV "
  			"connections
  ");
  	iucv_pm_state = IUCV_PM_RESTORING;

  	if (cpumask_empty(&iucv_irq_cpumask)) {

  		rc = iucv_query_maxconn();
  		rc = iucv_enable();
  		if (rc)
  			goto out;
  	}
  	if (dev->driver && dev->driver->pm && dev->driver->pm->restore)
  		rc = dev->driver->pm->restore(dev);
  out:
  	return rc;
  }

  struct iucv_interface iucv_if = {
  	.message_receive = iucv_message_receive,
  	.__message_receive = __iucv_message_receive,
  	.message_reply = iucv_message_reply,
  	.message_reject = iucv_message_reject,
  	.message_send = iucv_message_send,
  	.__message_send = __iucv_message_send,
  	.message_send2way = iucv_message_send2way,
  	.message_purge = iucv_message_purge,
  	.path_accept = iucv_path_accept,
  	.path_connect = iucv_path_connect,
  	.path_quiesce = iucv_path_quiesce,
  	.path_resume = iucv_path_resume,
  	.path_sever = iucv_path_sever,
  	.iucv_register = iucv_register,
  	.iucv_unregister = iucv_unregister,
  	.bus = NULL,
  	.root = NULL,
  };
  EXPORT_SYMBOL(iucv_if);

  /**
   * iucv_init
   *
   * Allocates and initializes various data structures.
   */

  static int __init iucv_init(void)

  {
  	int rc;

  	int cpu;

  
  	if (!MACHINE_IS_VM) {
  		rc = -EPROTONOSUPPORT;
  		goto out;
  	}

  	ctl_set_bit(0, 1);

  	rc = iucv_query_maxconn();
  	if (rc)

  		goto out_ctl;

  	rc = register_external_interrupt(0x4000, iucv_external_interrupt);

  	if (rc)

  		goto out_ctl;

  	iucv_root = root_device_register("iucv");

  	if (IS_ERR(iucv_root)) {
  		rc = PTR_ERR(iucv_root);

  		goto out_int;

  	}

  
  	for_each_online_cpu(cpu) {
  		/* Note: GFP_DMA used to get memory below 2G */
  		iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
  				     GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
  		if (!iucv_irq_data[cpu]) {
  			rc = -ENOMEM;
  			goto out_free;
  		}
  
  		/* Allocate parameter blocks. */
  		iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
  				  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
  		if (!iucv_param[cpu]) {
  			rc = -ENOMEM;
  			goto out_free;
  		}

  		iucv_param_irq[cpu] = kmalloc_node(sizeof(union iucv_param),
  				  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
  		if (!iucv_param_irq[cpu]) {
  			rc = -ENOMEM;
  			goto out_free;
  		}

  	}

  	rc = register_hotcpu_notifier(&iucv_cpu_notifier);
  	if (rc)
  		goto out_free;

  	rc = register_reboot_notifier(&iucv_reboot_notifier);
  	if (rc)
  		goto out_cpu;

  	ASCEBC(iucv_error_no_listener, 16);
  	ASCEBC(iucv_error_no_memory, 16);
  	ASCEBC(iucv_error_pathid, 16);
  	iucv_available = 1;

  	rc = bus_register(&iucv_bus);
  	if (rc)

  		goto out_reboot;

  	iucv_if.root = iucv_root;
  	iucv_if.bus = &iucv_bus;

  	return 0;

  out_reboot:
  	unregister_reboot_notifier(&iucv_reboot_notifier);

  out_cpu:
  	unregister_hotcpu_notifier(&iucv_cpu_notifier);

  out_free:
  	for_each_possible_cpu(cpu) {

  		kfree(iucv_param_irq[cpu]);
  		iucv_param_irq[cpu] = NULL;

  		kfree(iucv_param[cpu]);
  		iucv_param[cpu] = NULL;
  		kfree(iucv_irq_data[cpu]);
  		iucv_irq_data[cpu] = NULL;
  	}

  	root_device_unregister(iucv_root);

  out_int:
  	unregister_external_interrupt(0x4000, iucv_external_interrupt);

  out_ctl:
  	ctl_clear_bit(0, 1);

  out:
  	return rc;
  }
  
  /**
   * iucv_exit
   *
   * Frees everything allocated from iucv_init.
   */

  static void __exit iucv_exit(void)

  {

  	struct iucv_irq_list *p, *n;

  	int cpu;

  	spin_lock_irq(&iucv_queue_lock);
  	list_for_each_entry_safe(p, n, &iucv_task_queue, list)
  		kfree(p);

  	list_for_each_entry_safe(p, n, &iucv_work_queue, list)
  		kfree(p);

  	spin_unlock_irq(&iucv_queue_lock);

  	unregister_reboot_notifier(&iucv_reboot_notifier);

  	unregister_hotcpu_notifier(&iucv_cpu_notifier);

  	for_each_possible_cpu(cpu) {

  		kfree(iucv_param_irq[cpu]);
  		iucv_param_irq[cpu] = NULL;

  		kfree(iucv_param[cpu]);
  		iucv_param[cpu] = NULL;
  		kfree(iucv_irq_data[cpu]);
  		iucv_irq_data[cpu] = NULL;
  	}

  	root_device_unregister(iucv_root);

  	bus_unregister(&iucv_bus);
  	unregister_external_interrupt(0x4000, iucv_external_interrupt);
  }
  
  subsys_initcall(iucv_init);
  module_exit(iucv_exit);

  MODULE_AUTHOR("(C) 2001 IBM Corp. by Fritz Elfert (felfert@millenux.com)");
  MODULE_DESCRIPTION("Linux for S/390 IUCV lowlevel driver");
  MODULE_LICENSE("GPL");