appldata_base.c

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/*
 * 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) {
        len = sprintf(buf, appldata_timer_active ? "1\n" : "0\n");
        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) {
        len = sprintf(buf, ops->active ? "1\n" : "0\n");
        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);