arch/s390/appldata/appldata_base.c - kernel/common - Git at Google

 /*
  * Base infrastructure for Linux-z/VM Monitor Stream, Stage 1.
  * Exports appldata_register_ops() and appldata_unregister_ops() for the
  * data gathering modules.
  *
  * Copyright IBM Corp. 2003, 2009
  *
  * Author: Gerald Schaefer <[email protected]>
  */

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

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/proc_fs.h>
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/pagemap.h>
 #include <linux/sysctl.h>
 #include <linux/notifier.h>
 #include <linux/cpu.h>
 #include <linux/workqueue.h>
 #include <linux/suspend.h>
 #include <linux/platform_device.h>
 #include <asm/appldata.h>
 #include <asm/vtimer.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 #include <asm/smp.h>

 #include "appldata.h"


 #define APPLDATA_CPU_INTERVAL	10000		/* default (CPU) time for
 						   sampling interval in
 						   milliseconds */

 #define TOD_MICRO	0x01000			/* nr. of TOD clock units
 						   for 1 microsecond */

 static struct platform_device *appldata_pdev;

 /*
  * /proc entries (sysctl)
  */
 static const char appldata_proc_name[APPLDATA_PROC_NAME_LENGTH] = "appldata";
 static int appldata_timer_handler(ctl_table *ctl, int write,
 				  void __user *buffer, size_t *lenp, loff_t *ppos);
 static int appldata_interval_handler(ctl_table *ctl, int write,
 					 void __user *buffer,
 					 size_t *lenp, loff_t *ppos);

 static struct ctl_table_header *appldata_sysctl_header;
 static struct ctl_table appldata_table[] = {
 	{
 		.procname	= "timer",
 		.mode		= S_IRUGO | S_IWUSR,
 		.proc_handler	= appldata_timer_handler,
 	},
 	{
 		.procname	= "interval",
 		.mode		= S_IRUGO | S_IWUSR,
 		.proc_handler	= appldata_interval_handler,
 	},
 	{ },
 };

 static struct ctl_table appldata_dir_table[] = {
 	{
 		.procname	= appldata_proc_name,
 		.maxlen		= 0,
 		.mode		= S_IRUGO | S_IXUGO,
 		.child		= appldata_table,
 	},
 	{ },
 };

 /*
  * Timer
  */
 static struct vtimer_list appldata_timer;

 static DEFINE_SPINLOCK(appldata_timer_lock);
 static int appldata_interval = APPLDATA_CPU_INTERVAL;
 static int appldata_timer_active;
 static int appldata_timer_suspended = 0;

 /*
  * Work queue
  */
 static struct workqueue_struct *appldata_wq;
 static void appldata_work_fn(struct work_struct *work);
 static DECLARE_WORK(appldata_work, appldata_work_fn);


 /*
  * Ops list
  */
 static DEFINE_MUTEX(appldata_ops_mutex);
 static LIST_HEAD(appldata_ops_list);


 /*************************** timer, work, DIAG *******************************/
 /*
  * appldata_timer_function()
  *
  * schedule work and reschedule timer
  */
 static void appldata_timer_function(unsigned long data)
 {
 	queue_work(appldata_wq, (struct work_struct *) data);
 }

 /*
  * appldata_work_fn()
  *
  * call data gathering function for each (active) module
  */
 static void appldata_work_fn(struct work_struct *work)
 {
 	struct list_head *lh;
 	struct appldata_ops *ops;

 	mutex_lock(&appldata_ops_mutex);
 	list_for_each(lh, &appldata_ops_list) {
 		ops = list_entry(lh, struct appldata_ops, list);
 		if (ops->active == 1) {
 			ops->callback(ops->data);
 		}
 	}
 	mutex_unlock(&appldata_ops_mutex);
 }

 /*
  * appldata_diag()
  *
  * prepare parameter list, issue DIAG 0xDC
  */
 int appldata_diag(char record_nr, u16 function, unsigned long buffer,
 			u16 length, char *mod_lvl)
 {
 	struct appldata_product_id id = {
 		.prod_nr    = {0xD3, 0xC9, 0xD5, 0xE4,
 			       0xE7, 0xD2, 0xD9},	/* "LINUXKR" */
 		.prod_fn    = 0xD5D3,			/* "NL" */
 		.version_nr = 0xF2F6,			/* "26" */
 		.release_nr = 0xF0F1,			/* "01" */
 	};

 	id.record_nr = record_nr;
 	id.mod_lvl = (mod_lvl[0]) << 8 | mod_lvl[1];
 	return appldata_asm(&id, function, (void *) buffer, length);
 }
 /************************ timer, work, DIAG <END> ****************************/


 /****************************** /proc stuff **********************************/

 #define APPLDATA_ADD_TIMER	0
 #define APPLDATA_DEL_TIMER	1
 #define APPLDATA_MOD_TIMER	2

 /*
  * __appldata_vtimer_setup()
  *
  * Add, delete or modify virtual timers on all online cpus.
  * The caller needs to get the appldata_timer_lock spinlock.
  */
 static void __appldata_vtimer_setup(int cmd)
 {
 	u64 timer_interval = (u64) appldata_interval * 1000 * TOD_MICRO;

 	switch (cmd) {
 	case APPLDATA_ADD_TIMER:
 		if (appldata_timer_active)
 			break;
 		appldata_timer.expires = timer_interval;
 		add_virt_timer_periodic(&appldata_timer);
 		appldata_timer_active = 1;
 		break;
 	case APPLDATA_DEL_TIMER:
 		del_virt_timer(&appldata_timer);
 		if (!appldata_timer_active)
 			break;
 		appldata_timer_active = 0;
 		break;
 	case APPLDATA_MOD_TIMER:
 		if (!appldata_timer_active)
 			break;
 		mod_virt_timer_periodic(&appldata_timer, timer_interval);
 	}
 }

 /*
  * appldata_timer_handler()
  *
  * Start/Stop timer, show status of timer (0 = not active, 1 = active)
  */
 static int
 appldata_timer_handler(ctl_table *ctl, int write,
 			   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	int len;
 	char buf[2];

 	if (!*lenp || *ppos) {
 		*lenp = 0;
 		return 0;
 	}
 	if (!write) {
 		strncpy(buf, appldata_timer_active ? "1\n" : "0\n",
 			ARRAY_SIZE(buf));
 		len = strnlen(buf, ARRAY_SIZE(buf));
 		if (len > *lenp)
 			len = *lenp;
 		if (copy_to_user(buffer, buf, len))
 			return -EFAULT;
 		goto out;
 	}
 	len = *lenp;
 	if (copy_from_user(buf, buffer, len > sizeof(buf) ? sizeof(buf) : len))
 		return -EFAULT;
 	spin_lock(&appldata_timer_lock);
 	if (buf[0] == '1')
 		__appldata_vtimer_setup(APPLDATA_ADD_TIMER);
 	else if (buf[0] == '0')
 		__appldata_vtimer_setup(APPLDATA_DEL_TIMER);
 	spin_unlock(&appldata_timer_lock);
 out:
 	*lenp = len;
 	*ppos += len;
 	return 0;
 }

 /*
  * appldata_interval_handler()
  *
  * Set (CPU) timer interval for collection of data (in milliseconds), show
  * current timer interval.
  */
 static int
 appldata_interval_handler(ctl_table *ctl, int write,
 			   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	int len, interval;
 	char buf[16];

 	if (!*lenp || *ppos) {
 		*lenp = 0;
 		return 0;
 	}
 	if (!write) {
 		len = sprintf(buf, "%i\n", appldata_interval);
 		if (len > *lenp)
 			len = *lenp;
 		if (copy_to_user(buffer, buf, len))
 			return -EFAULT;
 		goto out;
 	}
 	len = *lenp;
 	if (copy_from_user(buf, buffer, len > sizeof(buf) ? sizeof(buf) : len))
 		return -EFAULT;
 	interval = 0;
 	sscanf(buf, "%i", &interval);
 	if (interval <= 0)
 		return -EINVAL;

 	spin_lock(&appldata_timer_lock);
 	appldata_interval = interval;
 	__appldata_vtimer_setup(APPLDATA_MOD_TIMER);
 	spin_unlock(&appldata_timer_lock);
 out:
 	*lenp = len;
 	*ppos += len;
 	return 0;
 }

 /*
  * appldata_generic_handler()
  *
  * Generic start/stop monitoring and DIAG, show status of
  * monitoring (0 = not in process, 1 = in process)
  */
 static int
 appldata_generic_handler(ctl_table *ctl, int write,
 			   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct appldata_ops *ops = NULL, *tmp_ops;
 	int rc, len, found;
 	char buf[2];
 	struct list_head *lh;

 	found = 0;
 	mutex_lock(&appldata_ops_mutex);
 	list_for_each(lh, &appldata_ops_list) {
 		tmp_ops = list_entry(lh, struct appldata_ops, list);
 		if (&tmp_ops->ctl_table[2] == ctl) {
 			found = 1;
 		}
 	}
 	if (!found) {
 		mutex_unlock(&appldata_ops_mutex);
 		return -ENODEV;
 	}
 	ops = ctl->data;
 	if (!try_module_get(ops->owner)) {	// protect this function
 		mutex_unlock(&appldata_ops_mutex);
 		return -ENODEV;
 	}
 	mutex_unlock(&appldata_ops_mutex);

 	if (!*lenp || *ppos) {
 		*lenp = 0;
 		module_put(ops->owner);
 		return 0;
 	}
 	if (!write) {
 		strncpy(buf, ops->active ? "1\n" : "0\n", ARRAY_SIZE(buf));
 		len = strnlen(buf, ARRAY_SIZE(buf));
 		if (len > *lenp)
 			len = *lenp;
 		if (copy_to_user(buffer, buf, len)) {
 			module_put(ops->owner);
 			return -EFAULT;
 		}
 		goto out;
 	}
 	len = *lenp;
 	if (copy_from_user(buf, buffer,
 			   len > sizeof(buf) ? sizeof(buf) : len)) {
 		module_put(ops->owner);
 		return -EFAULT;
 	}

 	mutex_lock(&appldata_ops_mutex);
 	if ((buf[0] == '1') && (ops->active == 0)) {
 		// protect work queue callback
 		if (!try_module_get(ops->owner)) {
 			mutex_unlock(&appldata_ops_mutex);
 			module_put(ops->owner);
 			return -ENODEV;
 		}
 		ops->callback(ops->data);	// init record
 		rc = appldata_diag(ops->record_nr,
 					APPLDATA_START_INTERVAL_REC,
 					(unsigned long) ops->data, ops->size,
 					ops->mod_lvl);
 		if (rc != 0) {
 			pr_err("Starting the data collection for %s "
 			       "failed with rc=%d\n", ops->name, rc);
 			module_put(ops->owner);
 		} else
 			ops->active = 1;
 	} else if ((buf[0] == '0') && (ops->active == 1)) {
 		ops->active = 0;
 		rc = appldata_diag(ops->record_nr, APPLDATA_STOP_REC,
 				(unsigned long) ops->data, ops->size,
 				ops->mod_lvl);
 		if (rc != 0)
 			pr_err("Stopping the data collection for %s "
 			       "failed with rc=%d\n", ops->name, rc);
 		module_put(ops->owner);
 	}
 	mutex_unlock(&appldata_ops_mutex);
 out:
 	*lenp = len;
 	*ppos += len;
 	module_put(ops->owner);
 	return 0;
 }

 /*************************** /proc stuff <END> *******************************/


 /************************* module-ops management *****************************/
 /*
  * appldata_register_ops()
  *
  * update ops list, register /proc/sys entries
  */
 int appldata_register_ops(struct appldata_ops *ops)
 {
 	if (ops->size > APPLDATA_MAX_REC_SIZE)
 		return -EINVAL;

 	ops->ctl_table = kzalloc(4 * sizeof(struct ctl_table), GFP_KERNEL);
 	if (!ops->ctl_table)
 		return -ENOMEM;

 	mutex_lock(&appldata_ops_mutex);
 	list_add(&ops->list, &appldata_ops_list);
 	mutex_unlock(&appldata_ops_mutex);

 	ops->ctl_table[0].procname = appldata_proc_name;
 	ops->ctl_table[0].maxlen   = 0;
 	ops->ctl_table[0].mode     = S_IRUGO | S_IXUGO;
 	ops->ctl_table[0].child    = &ops->ctl_table[2];

 	ops->ctl_table[2].procname = ops->name;
 	ops->ctl_table[2].mode     = S_IRUGO | S_IWUSR;
 	ops->ctl_table[2].proc_handler = appldata_generic_handler;
 	ops->ctl_table[2].data = ops;

 	ops->sysctl_header = register_sysctl_table(ops->ctl_table);
 	if (!ops->sysctl_header)
 		goto out;
 	return 0;
 out:
 	mutex_lock(&appldata_ops_mutex);
 	list_del(&ops->list);
 	mutex_unlock(&appldata_ops_mutex);
 	kfree(ops->ctl_table);
 	return -ENOMEM;
 }

 /*
  * appldata_unregister_ops()
  *
  * update ops list, unregister /proc entries, stop DIAG if necessary
  */
 void appldata_unregister_ops(struct appldata_ops *ops)
 {
 	mutex_lock(&appldata_ops_mutex);
 	list_del(&ops->list);
 	mutex_unlock(&appldata_ops_mutex);
 	unregister_sysctl_table(ops->sysctl_header);
 	kfree(ops->ctl_table);
 }
 /********************** module-ops management <END> **************************/


 /**************************** suspend / resume *******************************/
 static int appldata_freeze(struct device *dev)
 {
 	struct appldata_ops *ops;
 	int rc;
 	struct list_head *lh;

 	spin_lock(&appldata_timer_lock);
 	if (appldata_timer_active) {
 		__appldata_vtimer_setup(APPLDATA_DEL_TIMER);
 		appldata_timer_suspended = 1;
 	}
 	spin_unlock(&appldata_timer_lock);

 	mutex_lock(&appldata_ops_mutex);
 	list_for_each(lh, &appldata_ops_list) {
 		ops = list_entry(lh, struct appldata_ops, list);
 		if (ops->active == 1) {
 			rc = appldata_diag(ops->record_nr, APPLDATA_STOP_REC,
 					(unsigned long) ops->data, ops->size,
 					ops->mod_lvl);
 			if (rc != 0)
 				pr_err("Stopping the data collection for %s "
 				       "failed with rc=%d\n", ops->name, rc);
 		}
 	}
 	mutex_unlock(&appldata_ops_mutex);
 	return 0;
 }

 static int appldata_restore(struct device *dev)
 {
 	struct appldata_ops *ops;
 	int rc;
 	struct list_head *lh;

 	spin_lock(&appldata_timer_lock);
 	if (appldata_timer_suspended) {
 		__appldata_vtimer_setup(APPLDATA_ADD_TIMER);
 		appldata_timer_suspended = 0;
 	}
 	spin_unlock(&appldata_timer_lock);

 	mutex_lock(&appldata_ops_mutex);
 	list_for_each(lh, &appldata_ops_list) {
 		ops = list_entry(lh, struct appldata_ops, list);
 		if (ops->active == 1) {
 			ops->callback(ops->data);	// init record
 			rc = appldata_diag(ops->record_nr,
 					APPLDATA_START_INTERVAL_REC,
 					(unsigned long) ops->data, ops->size,
 					ops->mod_lvl);
 			if (rc != 0) {
 				pr_err("Starting the data collection for %s "
 				       "failed with rc=%d\n", ops->name, rc);
 			}
 		}
 	}
 	mutex_unlock(&appldata_ops_mutex);
 	return 0;
 }

 static int appldata_thaw(struct device *dev)
 {
 	return appldata_restore(dev);
 }

 static const struct dev_pm_ops appldata_pm_ops = {
 	.freeze		= appldata_freeze,
 	.thaw		= appldata_thaw,
 	.restore	= appldata_restore,
 };

 static struct platform_driver appldata_pdrv = {
 	.driver = {
 		.name	= "appldata",
 		.owner	= THIS_MODULE,
 		.pm	= &appldata_pm_ops,
 	},
 };
 /************************* suspend / resume <END> ****************************/


 /******************************* init / exit *********************************/

 /*
  * appldata_init()
  *
  * init timer, register /proc entries
  */
 static int __init appldata_init(void)
 {
 	int rc;

 	appldata_timer.function = appldata_timer_function;
 	appldata_timer.data = (unsigned long) &appldata_work;

 	rc = platform_driver_register(&appldata_pdrv);
 	if (rc)
 		return rc;

 	appldata_pdev = platform_device_register_simple("appldata", -1, NULL,
 							0);
 	if (IS_ERR(appldata_pdev)) {
 		rc = PTR_ERR(appldata_pdev);
 		goto out_driver;
 	}
 	appldata_wq = create_singlethread_workqueue("appldata");
 	if (!appldata_wq) {
 		rc = -ENOMEM;
 		goto out_device;
 	}

 	appldata_sysctl_header = register_sysctl_table(appldata_dir_table);
 	return 0;

 out_device:
 	platform_device_unregister(appldata_pdev);
 out_driver:
 	platform_driver_unregister(&appldata_pdrv);
 	return rc;
 }

 __initcall(appldata_init);

 /**************************** init / exit <END> ******************************/

 EXPORT_SYMBOL_GPL(appldata_register_ops);
 EXPORT_SYMBOL_GPL(appldata_unregister_ops);
 EXPORT_SYMBOL_GPL(appldata_diag);

 #ifdef CONFIG_SWAP
 EXPORT_SYMBOL_GPL(si_swapinfo);
 #endif
 EXPORT_SYMBOL_GPL(nr_threads);
 EXPORT_SYMBOL_GPL(nr_running);
 EXPORT_SYMBOL_GPL(nr_iowait);
	/*
	* Base infrastructure for Linux-z/VM Monitor Stream, Stage 1.
	* Exports appldata_register_ops() and appldata_unregister_ops() for the
	* data gathering modules.
	*
	* Copyright IBM Corp. 2003, 2009
	*
	* Author: Gerald Schaefer <[email protected]>
	*/

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

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/errno.h>
	#include <linux/interrupt.h>
	#include <linux/proc_fs.h>
	#include <linux/mm.h>
	#include <linux/swap.h>
	#include <linux/pagemap.h>
	#include <linux/sysctl.h>
	#include <linux/notifier.h>
	#include <linux/cpu.h>
	#include <linux/workqueue.h>
	#include <linux/suspend.h>
	#include <linux/platform_device.h>
	#include <asm/appldata.h>
	#include <asm/vtimer.h>
	#include <asm/uaccess.h>
	#include <asm/io.h>
	#include <asm/smp.h>

	#include "appldata.h"


	#define APPLDATA_CPU_INTERVAL 10000 /* default (CPU) time for
	sampling interval in
	milliseconds */

	#define TOD_MICRO 0x01000 /* nr. of TOD clock units
	for 1 microsecond */

	static struct platform_device *appldata_pdev;

	/*
	* /proc entries (sysctl)
	*/
	static const char appldata_proc_name[APPLDATA_PROC_NAME_LENGTH] = "appldata";
	static int appldata_timer_handler(ctl_table *ctl, int write,
	void __user buffer, size_t lenp, loff_t *ppos);
	static int appldata_interval_handler(ctl_table *ctl, int write,
	void __user *buffer,
	size_t lenp, loff_t ppos);

	static struct ctl_table_header *appldata_sysctl_header;
	static struct ctl_table appldata_table[] = {
	{
	.procname = "timer",
	.mode = S_IRUGO \| S_IWUSR,
	.proc_handler = appldata_timer_handler,
	},
	{
	.procname = "interval",
	.mode = S_IRUGO \| S_IWUSR,
	.proc_handler = appldata_interval_handler,
	},
	{ },
	};

	static struct ctl_table appldata_dir_table[] = {
	{
	.procname = appldata_proc_name,
	.maxlen = 0,
	.mode = S_IRUGO \| S_IXUGO,
	.child = appldata_table,
	},
	{ },
	};

	/*
	* Timer
	*/
	static struct vtimer_list appldata_timer;

	static DEFINE_SPINLOCK(appldata_timer_lock);
	static int appldata_interval = APPLDATA_CPU_INTERVAL;
	static int appldata_timer_active;
	static int appldata_timer_suspended = 0;

	/*
	* Work queue
	*/
	static struct workqueue_struct *appldata_wq;
	static void appldata_work_fn(struct work_struct *work);
	static DECLARE_WORK(appldata_work, appldata_work_fn);


	/*
	* Ops list
	*/
	static DEFINE_MUTEX(appldata_ops_mutex);
	static LIST_HEAD(appldata_ops_list);


	/************************* timer, work, DIAG *****************************/
	/*
	* appldata_timer_function()
	*
	* schedule work and reschedule timer
	*/
	static void appldata_timer_function(unsigned long data)
	{
	queue_work(appldata_wq, (struct work_struct *) data);
	}

	/*
	* appldata_work_fn()
	*
	* call data gathering function for each (active) module
	*/
	static void appldata_work_fn(struct work_struct *work)
	{
	struct list_head *lh;
	struct appldata_ops *ops;

	mutex_lock(&appldata_ops_mutex);
	list_for_each(lh, &appldata_ops_list) {
	ops = list_entry(lh, struct appldata_ops, list);
	if (ops->active == 1) {
	ops->callback(ops->data);
	}
	}
	mutex_unlock(&appldata_ops_mutex);
	}

	/*
	* appldata_diag()
	*
	* prepare parameter list, issue DIAG 0xDC
	*/
	int appldata_diag(char record_nr, u16 function, unsigned long buffer,
	u16 length, char *mod_lvl)
	{
	struct appldata_product_id id = {
	.prod_nr = {0xD3, 0xC9, 0xD5, 0xE4,
	0xE7, 0xD2, 0xD9}, /* "LINUXKR" */
	.prod_fn = 0xD5D3, /* "NL" */
	.version_nr = 0xF2F6, /* "26" */
	.release_nr = 0xF0F1, /* "01" */
	};

	id.record_nr = record_nr;
	id.mod_lvl = (mod_lvl[0]) << 8 \| mod_lvl[1];
	return appldata_asm(&id, function, (void *) buffer, length);
	}
	/********************** timer, work, DIAG <END> **************************/


	/**************************** /proc stuff ********************************/

	#define APPLDATA_ADD_TIMER 0
	#define APPLDATA_DEL_TIMER 1
	#define APPLDATA_MOD_TIMER 2

	/*
	* __appldata_vtimer_setup()
	*
	* Add, delete or modify virtual timers on all online cpus.
	* The caller needs to get the appldata_timer_lock spinlock.
	*/
	static void __appldata_vtimer_setup(int cmd)
	{
	u64 timer_interval = (u64) appldata_interval * 1000 * TOD_MICRO;

	switch (cmd) {
	case APPLDATA_ADD_TIMER:
	if (appldata_timer_active)
	break;
	appldata_timer.expires = timer_interval;
	add_virt_timer_periodic(&appldata_timer);
	appldata_timer_active = 1;
	break;
	case APPLDATA_DEL_TIMER:
	del_virt_timer(&appldata_timer);
	if (!appldata_timer_active)
	break;
	appldata_timer_active = 0;
	break;
	case APPLDATA_MOD_TIMER:
	if (!appldata_timer_active)
	break;
	mod_virt_timer_periodic(&appldata_timer, timer_interval);
	}
	}

	/*
	* appldata_timer_handler()
	*
	* Start/Stop timer, show status of timer (0 = not active, 1 = active)
	*/
	static int
	appldata_timer_handler(ctl_table *ctl, int write,
	void __user buffer, size_t lenp, loff_t *ppos)
	{
	int len;
	char buf[2];

	if (!lenp \|\| ppos) {
	*lenp = 0;
	return 0;
	}
	if (!write) {
	strncpy(buf, appldata_timer_active ? "1\n" : "0\n",
	ARRAY_SIZE(buf));
	len = strnlen(buf, ARRAY_SIZE(buf));
	if (len > *lenp)
	len = *lenp;
	if (copy_to_user(buffer, buf, len))
	return -EFAULT;
	goto out;
	}
	len = *lenp;
	if (copy_from_user(buf, buffer, len > sizeof(buf) ? sizeof(buf) : len))
	return -EFAULT;
	spin_lock(&appldata_timer_lock);
	if (buf[0] == '1')
	__appldata_vtimer_setup(APPLDATA_ADD_TIMER);
	else if (buf[0] == '0')
	__appldata_vtimer_setup(APPLDATA_DEL_TIMER);
	spin_unlock(&appldata_timer_lock);
	out:
	*lenp = len;
	*ppos += len;
	return 0;
	}

	/*
	* appldata_interval_handler()
	*
	* Set (CPU) timer interval for collection of data (in milliseconds), show
	* current timer interval.
	*/
	static int
	appldata_interval_handler(ctl_table *ctl, int write,
	void __user buffer, size_t lenp, loff_t *ppos)
	{
	int len, interval;
	char buf[16];

	if (!lenp \|\| ppos) {
	*lenp = 0;
	return 0;
	}
	if (!write) {
	len = sprintf(buf, "%i\n", appldata_interval);
	if (len > *lenp)
	len = *lenp;
	if (copy_to_user(buffer, buf, len))
	return -EFAULT;
	goto out;
	}
	len = *lenp;
	if (copy_from_user(buf, buffer, len > sizeof(buf) ? sizeof(buf) : len))
	return -EFAULT;
	interval = 0;
	sscanf(buf, "%i", &interval);
	if (interval <= 0)
	return -EINVAL;

	spin_lock(&appldata_timer_lock);
	appldata_interval = interval;
	__appldata_vtimer_setup(APPLDATA_MOD_TIMER);
	spin_unlock(&appldata_timer_lock);
	out:
	*lenp = len;
	*ppos += len;
	return 0;
	}

	/*
	* appldata_generic_handler()
	*
	* Generic start/stop monitoring and DIAG, show status of
	* monitoring (0 = not in process, 1 = in process)
	*/
	static int
	appldata_generic_handler(ctl_table *ctl, int write,
	void __user buffer, size_t lenp, loff_t *ppos)
	{
	struct appldata_ops ops = NULL, tmp_ops;
	int rc, len, found;
	char buf[2];
	struct list_head *lh;

	found = 0;
	mutex_lock(&appldata_ops_mutex);
	list_for_each(lh, &appldata_ops_list) {
	tmp_ops = list_entry(lh, struct appldata_ops, list);
	if (&tmp_ops->ctl_table[2] == ctl) {
	found = 1;
	}
	}
	if (!found) {
	mutex_unlock(&appldata_ops_mutex);
	return -ENODEV;
	}
	ops = ctl->data;
	if (!try_module_get(ops->owner)) { // protect this function
	mutex_unlock(&appldata_ops_mutex);
	return -ENODEV;
	}
	mutex_unlock(&appldata_ops_mutex);

	if (!lenp \|\| ppos) {
	*lenp = 0;
	module_put(ops->owner);
	return 0;
	}
	if (!write) {
	strncpy(buf, ops->active ? "1\n" : "0\n", ARRAY_SIZE(buf));
	len = strnlen(buf, ARRAY_SIZE(buf));
	if (len > *lenp)
	len = *lenp;
	if (copy_to_user(buffer, buf, len)) {
	module_put(ops->owner);
	return -EFAULT;
	}
	goto out;
	}
	len = *lenp;
	if (copy_from_user(buf, buffer,
	len > sizeof(buf) ? sizeof(buf) : len)) {
	module_put(ops->owner);
	return -EFAULT;
	}

	mutex_lock(&appldata_ops_mutex);
	if ((buf[0] == '1') && (ops->active == 0)) {
	// protect work queue callback
	if (!try_module_get(ops->owner)) {
	mutex_unlock(&appldata_ops_mutex);
	module_put(ops->owner);
	return -ENODEV;
	}
	ops->callback(ops->data); // init record
	rc = appldata_diag(ops->record_nr,
	APPLDATA_START_INTERVAL_REC,
	(unsigned long) ops->data, ops->size,
	ops->mod_lvl);
	if (rc != 0) {
	pr_err("Starting the data collection for %s "
	"failed with rc=%d\n", ops->name, rc);
	module_put(ops->owner);
	} else
	ops->active = 1;
	} else if ((buf[0] == '0') && (ops->active == 1)) {
	ops->active = 0;
	rc = appldata_diag(ops->record_nr, APPLDATA_STOP_REC,
	(unsigned long) ops->data, ops->size,
	ops->mod_lvl);
	if (rc != 0)
	pr_err("Stopping the data collection for %s "
	"failed with rc=%d\n", ops->name, rc);
	module_put(ops->owner);
	}
	mutex_unlock(&appldata_ops_mutex);
	out:
	*lenp = len;
	*ppos += len;
	module_put(ops->owner);
	return 0;
	}

	/************************* /proc stuff <END> *****************************/


	/*********************** module-ops management ***************************/
	/*
	* appldata_register_ops()
	*
	* update ops list, register /proc/sys entries
	*/
	int appldata_register_ops(struct appldata_ops *ops)
	{
	if (ops->size > APPLDATA_MAX_REC_SIZE)
	return -EINVAL;

	ops->ctl_table = kzalloc(4 * sizeof(struct ctl_table), GFP_KERNEL);
	if (!ops->ctl_table)
	return -ENOMEM;

	mutex_lock(&appldata_ops_mutex);
	list_add(&ops->list, &appldata_ops_list);
	mutex_unlock(&appldata_ops_mutex);

	ops->ctl_table[0].procname = appldata_proc_name;
	ops->ctl_table[0].maxlen = 0;
	ops->ctl_table[0].mode = S_IRUGO \| S_IXUGO;
	ops->ctl_table[0].child = &ops->ctl_table[2];

	ops->ctl_table[2].procname = ops->name;
	ops->ctl_table[2].mode = S_IRUGO \| S_IWUSR;
	ops->ctl_table[2].proc_handler = appldata_generic_handler;
	ops->ctl_table[2].data = ops;

	ops->sysctl_header = register_sysctl_table(ops->ctl_table);
	if (!ops->sysctl_header)
	goto out;
	return 0;
	out:
	mutex_lock(&appldata_ops_mutex);
	list_del(&ops->list);
	mutex_unlock(&appldata_ops_mutex);
	kfree(ops->ctl_table);
	return -ENOMEM;
	}

	/*
	* appldata_unregister_ops()
	*
	* update ops list, unregister /proc entries, stop DIAG if necessary
	*/
	void appldata_unregister_ops(struct appldata_ops *ops)
	{
	mutex_lock(&appldata_ops_mutex);
	list_del(&ops->list);
	mutex_unlock(&appldata_ops_mutex);
	unregister_sysctl_table(ops->sysctl_header);
	kfree(ops->ctl_table);
	}
	/******************** module-ops management <END> ************************/


	/************************** suspend / resume *****************************/
	static int appldata_freeze(struct device *dev)
	{
	struct appldata_ops *ops;
	int rc;
	struct list_head *lh;

	spin_lock(&appldata_timer_lock);
	if (appldata_timer_active) {
	__appldata_vtimer_setup(APPLDATA_DEL_TIMER);
	appldata_timer_suspended = 1;
	}
	spin_unlock(&appldata_timer_lock);

	mutex_lock(&appldata_ops_mutex);
	list_for_each(lh, &appldata_ops_list) {
	ops = list_entry(lh, struct appldata_ops, list);
	if (ops->active == 1) {
	rc = appldata_diag(ops->record_nr, APPLDATA_STOP_REC,
	(unsigned long) ops->data, ops->size,
	ops->mod_lvl);
	if (rc != 0)
	pr_err("Stopping the data collection for %s "
	"failed with rc=%d\n", ops->name, rc);
	}
	}
	mutex_unlock(&appldata_ops_mutex);
	return 0;
	}

	static int appldata_restore(struct device *dev)
	{
	struct appldata_ops *ops;
	int rc;
	struct list_head *lh;

	spin_lock(&appldata_timer_lock);
	if (appldata_timer_suspended) {
	__appldata_vtimer_setup(APPLDATA_ADD_TIMER);
	appldata_timer_suspended = 0;
	}
	spin_unlock(&appldata_timer_lock);

	mutex_lock(&appldata_ops_mutex);
	list_for_each(lh, &appldata_ops_list) {
	ops = list_entry(lh, struct appldata_ops, list);
	if (ops->active == 1) {
	ops->callback(ops->data); // init record
	rc = appldata_diag(ops->record_nr,
	APPLDATA_START_INTERVAL_REC,
	(unsigned long) ops->data, ops->size,
	ops->mod_lvl);
	if (rc != 0) {
	pr_err("Starting the data collection for %s "
	"failed with rc=%d\n", ops->name, rc);
	}
	}
	}
	mutex_unlock(&appldata_ops_mutex);
	return 0;
	}

	static int appldata_thaw(struct device *dev)
	{
	return appldata_restore(dev);
	}

	static const struct dev_pm_ops appldata_pm_ops = {
	.freeze = appldata_freeze,
	.thaw = appldata_thaw,
	.restore = appldata_restore,
	};

	static struct platform_driver appldata_pdrv = {
	.driver = {
	.name = "appldata",
	.owner = THIS_MODULE,
	.pm = &appldata_pm_ops,
	},
	};
	/*********************** suspend / resume <END> **************************/


	/***************************** init / exit *******************************/

	/*
	* appldata_init()
	*
	* init timer, register /proc entries
	*/
	static int __init appldata_init(void)
	{
	int rc;

	appldata_timer.function = appldata_timer_function;
	appldata_timer.data = (unsigned long) &appldata_work;

	rc = platform_driver_register(&appldata_pdrv);
	if (rc)
	return rc;

	appldata_pdev = platform_device_register_simple("appldata", -1, NULL,
	0);
	if (IS_ERR(appldata_pdev)) {
	rc = PTR_ERR(appldata_pdev);
	goto out_driver;
	}
	appldata_wq = create_singlethread_workqueue("appldata");
	if (!appldata_wq) {
	rc = -ENOMEM;
	goto out_device;
	}

	appldata_sysctl_header = register_sysctl_table(appldata_dir_table);
	return 0;

	out_device:
	platform_device_unregister(appldata_pdev);
	out_driver:
	platform_driver_unregister(&appldata_pdrv);
	return rc;
	}

	__initcall(appldata_init);

	/************************** init / exit <END> ****************************/

	EXPORT_SYMBOL_GPL(appldata_register_ops);
	EXPORT_SYMBOL_GPL(appldata_unregister_ops);
	EXPORT_SYMBOL_GPL(appldata_diag);

	#ifdef CONFIG_SWAP
	EXPORT_SYMBOL_GPL(si_swapinfo);
	#endif
	EXPORT_SYMBOL_GPL(nr_threads);
	EXPORT_SYMBOL_GPL(nr_running);
	EXPORT_SYMBOL_GPL(nr_iowait);